[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/block/Kconfig b/src/kernel/linux/v4.14/block/Kconfig
new file mode 100644
index 0000000..28ec557
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/Kconfig
@@ -0,0 +1,215 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Block layer core configuration
+#
+menuconfig BLOCK
+ bool "Enable the block layer" if EXPERT
+ default y
+ select SBITMAP
+ select SRCU
+ help
+ Provide block layer support for the kernel.
+
+ Disable this option to remove the block layer support from the
+ kernel. This may be useful for embedded devices.
+
+ If this option is disabled:
+
+ - block device files will become unusable
+ - some filesystems (such as ext3) will become unavailable.
+
+ Also, SCSI character devices and USB storage will be disabled since
+ they make use of various block layer definitions and facilities.
+
+ Say Y here unless you know you really don't want to mount disks and
+ suchlike.
+
+if BLOCK
+
+config LBDAF
+ bool "Support for large (2TB+) block devices and files"
+ depends on !64BIT
+ default y
+ help
+ Enable block devices or files of size 2TB and larger.
+
+ This option is required to support the full capacity of large
+ (2TB+) block devices, including RAID, disk, Network Block Device,
+ Logical Volume Manager (LVM) and loopback.
+
+ This option also enables support for single files larger than
+ 2TB.
+
+ The ext4 filesystem requires that this feature be enabled in
+ order to support filesystems that have the huge_file feature
+ enabled. Otherwise, it will refuse to mount in the read-write
+ mode any filesystems that use the huge_file feature, which is
+ enabled by default by mke2fs.ext4.
+
+ The GFS2 filesystem also requires this feature.
+
+ If unsure, say Y.
+
+config BLK_SCSI_REQUEST
+ bool
+
+config BLK_DEV_BSG
+ bool "Block layer SG support v4"
+ default y
+ select BLK_SCSI_REQUEST
+ help
+ Saying Y here will enable generic SG (SCSI generic) v4 support
+ for any block device.
+
+ Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
+ can handle complicated SCSI commands: tagged variable length cdbs
+ with bidirectional data transfers and generic request/response
+ protocols (e.g. Task Management Functions and SMP in Serial
+ Attached SCSI).
+
+ This option is required by recent UDEV versions to properly
+ access device serial numbers, etc.
+
+ If unsure, say Y.
+
+config BLK_DEV_BSGLIB
+ bool "Block layer SG support v4 helper lib"
+ default n
+ select BLK_DEV_BSG
+ select BLK_SCSI_REQUEST
+ help
+ Subsystems will normally enable this if needed. Users will not
+ normally need to manually enable this.
+
+ If unsure, say N.
+
+config BLK_DEV_INTEGRITY
+ bool "Block layer data integrity support"
+ select CRC_T10DIF if BLK_DEV_INTEGRITY
+ ---help---
+ Some storage devices allow extra information to be
+ stored/retrieved to help protect the data. The block layer
+ data integrity option provides hooks which can be used by
+ filesystems to ensure better data integrity.
+
+ Say yes here if you have a storage device that provides the
+ T10/SCSI Data Integrity Field or the T13/ATA External Path
+ Protection. If in doubt, say N.
+
+config BLK_DEV_ZONED
+ bool "Zoned block device support"
+ ---help---
+ Block layer zoned block device support. This option enables
+ support for ZAC/ZBC host-managed and host-aware zoned block devices.
+
+ Say yes here if you have a ZAC or ZBC storage device.
+
+config BLK_DEV_THROTTLING
+ bool "Block layer bio throttling support"
+ depends on BLK_CGROUP=y
+ default n
+ ---help---
+ Block layer bio throttling support. It can be used to limit
+ the IO rate to a device. IO rate policies are per cgroup and
+ one needs to mount and use blkio cgroup controller for creating
+ cgroups and specifying per device IO rate policies.
+
+ See Documentation/cgroups/blkio-controller.txt for more information.
+
+config BLK_DEV_THROTTLING_LOW
+ bool "Block throttling .low limit interface support (EXPERIMENTAL)"
+ depends on BLK_DEV_THROTTLING
+ default n
+ ---help---
+ Add .low limit interface for block throttling. The low limit is a best
+ effort limit to prioritize cgroups. Depending on the setting, the limit
+ can be used to protect cgroups in terms of bandwidth/iops and better
+ utilize disk resource.
+
+ Note, this is an experimental interface and could be changed someday.
+
+config BLK_CMDLINE_PARSER
+ bool "Block device command line partition parser"
+ default n
+ ---help---
+ Enabling this option allows you to specify the partition layout from
+ the kernel boot args. This is typically of use for embedded devices
+ which don't otherwise have any standardized method for listing the
+ partitions on a block device.
+
+ See Documentation/block/cmdline-partition.txt for more information.
+
+config BLK_WBT
+ bool "Enable support for block device writeback throttling"
+ default n
+ ---help---
+ Enabling this option enables the block layer to throttle buffered
+ background writeback from the VM, making it more smooth and having
+ less impact on foreground operations. The throttling is done
+ dynamically on an algorithm loosely based on CoDel, factoring in
+ the realtime performance of the disk.
+
+config BLK_WBT_SQ
+ bool "Single queue writeback throttling"
+ default n
+ depends on BLK_WBT
+ ---help---
+ Enable writeback throttling by default on legacy single queue devices
+
+config BLK_WBT_MQ
+ bool "Multiqueue writeback throttling"
+ default y
+ depends on BLK_WBT
+ ---help---
+ Enable writeback throttling by default on multiqueue devices.
+ Multiqueue currently doesn't have support for IO scheduling,
+ enabling this option is recommended.
+
+config BLK_DEBUG_FS
+ bool "Block layer debugging information in debugfs"
+ default y
+ depends on DEBUG_FS
+ ---help---
+ Include block layer debugging information in debugfs. This information
+ is mostly useful for kernel developers, but it doesn't incur any cost
+ at runtime.
+
+ Unless you are building a kernel for a tiny system, you should
+ say Y here.
+
+config BLK_SED_OPAL
+ bool "Logic for interfacing with Opal enabled SEDs"
+ ---help---
+ Builds Logic for interfacing with Opal enabled controllers.
+ Enabling this option enables users to setup/unlock/lock
+ Locking ranges for SED devices using the Opal protocol.
+
+menu "Partition Types"
+
+source "block/partitions/Kconfig"
+
+endmenu
+
+endif # BLOCK
+
+config BLOCK_COMPAT
+ bool
+ depends on BLOCK && COMPAT
+ default y
+
+config BLK_MQ_PCI
+ bool
+ depends on BLOCK && PCI
+ default y
+
+config BLK_MQ_VIRTIO
+ bool
+ depends on BLOCK && VIRTIO
+ default y
+
+config BLK_MQ_RDMA
+ bool
+ depends on BLOCK && INFINIBAND
+ default y
+
+source block/Kconfig.iosched
diff --git a/src/kernel/linux/v4.14/block/Kconfig.iosched b/src/kernel/linux/v4.14/block/Kconfig.iosched
new file mode 100644
index 0000000..a4a8914
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/Kconfig.iosched
@@ -0,0 +1,105 @@
+# SPDX-License-Identifier: GPL-2.0
+if BLOCK
+
+menu "IO Schedulers"
+
+config IOSCHED_NOOP
+ bool
+ default y
+ ---help---
+ The no-op I/O scheduler is a minimal scheduler that does basic merging
+ and sorting. Its main uses include non-disk based block devices like
+ memory devices, and specialised software or hardware environments
+ that do their own scheduling and require only minimal assistance from
+ the kernel.
+
+config IOSCHED_DEADLINE
+ tristate "Deadline I/O scheduler"
+ default y
+ ---help---
+ The deadline I/O scheduler is simple and compact. It will provide
+ CSCAN service with FIFO expiration of requests, switching to
+ a new point in the service tree and doing a batch of IO from there
+ in case of expiry.
+
+config IOSCHED_CFQ
+ tristate "CFQ I/O scheduler"
+ default y
+ ---help---
+ The CFQ I/O scheduler tries to distribute bandwidth equally
+ among all processes in the system. It should provide a fair
+ and low latency working environment, suitable for both desktop
+ and server systems.
+
+ This is the default I/O scheduler.
+
+config CFQ_GROUP_IOSCHED
+ bool "CFQ Group Scheduling support"
+ depends on IOSCHED_CFQ && BLK_CGROUP
+ default n
+ ---help---
+ Enable group IO scheduling in CFQ.
+
+choice
+
+ prompt "Default I/O scheduler"
+ default DEFAULT_CFQ
+ help
+ Select the I/O scheduler which will be used by default for all
+ block devices.
+
+ config DEFAULT_DEADLINE
+ bool "Deadline" if IOSCHED_DEADLINE=y
+
+ config DEFAULT_CFQ
+ bool "CFQ" if IOSCHED_CFQ=y
+
+ config DEFAULT_NOOP
+ bool "No-op"
+
+endchoice
+
+config DEFAULT_IOSCHED
+ string
+ default "deadline" if DEFAULT_DEADLINE
+ default "cfq" if DEFAULT_CFQ
+ default "noop" if DEFAULT_NOOP
+
+config MQ_IOSCHED_DEADLINE
+ tristate "MQ deadline I/O scheduler"
+ default y
+ ---help---
+ MQ version of the deadline IO scheduler.
+
+config MQ_IOSCHED_KYBER
+ tristate "Kyber I/O scheduler"
+ default y
+ ---help---
+ The Kyber I/O scheduler is a low-overhead scheduler suitable for
+ multiqueue and other fast devices. Given target latencies for reads and
+ synchronous writes, it will self-tune queue depths to achieve that
+ goal.
+
+config IOSCHED_BFQ
+ tristate "BFQ I/O scheduler"
+ default n
+ ---help---
+ BFQ I/O scheduler for BLK-MQ. BFQ distributes the bandwidth of
+ of the device among all processes according to their weights,
+ regardless of the device parameters and with any workload. It
+ also guarantees a low latency to interactive and soft
+ real-time applications. Details in
+ Documentation/block/bfq-iosched.txt
+
+config BFQ_GROUP_IOSCHED
+ bool "BFQ hierarchical scheduling support"
+ depends on IOSCHED_BFQ && BLK_CGROUP
+ default n
+ ---help---
+
+ Enable hierarchical scheduling in BFQ, using the blkio
+ (cgroups-v1) or io (cgroups-v2) controller.
+
+endmenu
+
+endif
diff --git a/src/kernel/linux/v4.14/block/Makefile b/src/kernel/linux/v4.14/block/Makefile
new file mode 100644
index 0000000..6a56303
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/Makefile
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the kernel block layer
+#
+
+obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-tag.o blk-sysfs.o \
+ blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
+ blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
+ blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \
+ blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \
+ genhd.o partition-generic.o ioprio.o \
+ badblocks.o partitions/
+
+obj-$(CONFIG_BOUNCE) += bounce.o
+obj-$(CONFIG_BLK_SCSI_REQUEST) += scsi_ioctl.o
+obj-$(CONFIG_BLK_DEV_BSG) += bsg.o
+obj-$(CONFIG_BLK_DEV_BSGLIB) += bsg-lib.o
+obj-$(CONFIG_BLK_CGROUP) += blk-cgroup.o
+obj-$(CONFIG_BLK_DEV_THROTTLING) += blk-throttle.o
+obj-$(CONFIG_IOSCHED_NOOP) += noop-iosched.o
+obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o
+obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
+obj-$(CONFIG_MQ_IOSCHED_DEADLINE) += mq-deadline.o
+obj-$(CONFIG_MQ_IOSCHED_KYBER) += kyber-iosched.o
+bfq-y := bfq-iosched.o bfq-wf2q.o bfq-cgroup.o
+obj-$(CONFIG_IOSCHED_BFQ) += bfq.o
+
+obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
+obj-$(CONFIG_BLK_CMDLINE_PARSER) += cmdline-parser.o
+obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o
+obj-$(CONFIG_BLK_MQ_PCI) += blk-mq-pci.o
+obj-$(CONFIG_BLK_MQ_VIRTIO) += blk-mq-virtio.o
+obj-$(CONFIG_BLK_MQ_RDMA) += blk-mq-rdma.o
+obj-$(CONFIG_BLK_DEV_ZONED) += blk-zoned.o
+obj-$(CONFIG_BLK_WBT) += blk-wbt.o
+obj-$(CONFIG_BLK_DEBUG_FS) += blk-mq-debugfs.o
+obj-$(CONFIG_BLK_SED_OPAL) += sed-opal.o
diff --git a/src/kernel/linux/v4.14/block/badblocks.c b/src/kernel/linux/v4.14/block/badblocks.c
new file mode 100644
index 0000000..91f7bcf
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/badblocks.c
@@ -0,0 +1,611 @@
+/*
+ * Bad block management
+ *
+ * - Heavily based on MD badblocks code from Neil Brown
+ *
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/badblocks.h>
+#include <linux/seqlock.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/stddef.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+
+/**
+ * badblocks_check() - check a given range for bad sectors
+ * @bb: the badblocks structure that holds all badblock information
+ * @s: sector (start) at which to check for badblocks
+ * @sectors: number of sectors to check for badblocks
+ * @first_bad: pointer to store location of the first badblock
+ * @bad_sectors: pointer to store number of badblocks after @first_bad
+ *
+ * We can record which blocks on each device are 'bad' and so just
+ * fail those blocks, or that stripe, rather than the whole device.
+ * Entries in the bad-block table are 64bits wide. This comprises:
+ * Length of bad-range, in sectors: 0-511 for lengths 1-512
+ * Start of bad-range, sector offset, 54 bits (allows 8 exbibytes)
+ * A 'shift' can be set so that larger blocks are tracked and
+ * consequently larger devices can be covered.
+ * 'Acknowledged' flag - 1 bit. - the most significant bit.
+ *
+ * Locking of the bad-block table uses a seqlock so badblocks_check
+ * might need to retry if it is very unlucky.
+ * We will sometimes want to check for bad blocks in a bi_end_io function,
+ * so we use the write_seqlock_irq variant.
+ *
+ * When looking for a bad block we specify a range and want to
+ * know if any block in the range is bad. So we binary-search
+ * to the last range that starts at-or-before the given endpoint,
+ * (or "before the sector after the target range")
+ * then see if it ends after the given start.
+ *
+ * Return:
+ * 0: there are no known bad blocks in the range
+ * 1: there are known bad block which are all acknowledged
+ * -1: there are bad blocks which have not yet been acknowledged in metadata.
+ * plus the start/length of the first bad section we overlap.
+ */
+int badblocks_check(struct badblocks *bb, sector_t s, int sectors,
+ sector_t *first_bad, int *bad_sectors)
+{
+ int hi;
+ int lo;
+ u64 *p = bb->page;
+ int rv;
+ sector_t target = s + sectors;
+ unsigned seq;
+
+ if (bb->shift > 0) {
+ /* round the start down, and the end up */
+ s >>= bb->shift;
+ target += (1<<bb->shift) - 1;
+ target >>= bb->shift;
+ sectors = target - s;
+ }
+ /* 'target' is now the first block after the bad range */
+
+retry:
+ seq = read_seqbegin(&bb->lock);
+ lo = 0;
+ rv = 0;
+ hi = bb->count;
+
+ /* Binary search between lo and hi for 'target'
+ * i.e. for the last range that starts before 'target'
+ */
+ /* INVARIANT: ranges before 'lo' and at-or-after 'hi'
+ * are known not to be the last range before target.
+ * VARIANT: hi-lo is the number of possible
+ * ranges, and decreases until it reaches 1
+ */
+ while (hi - lo > 1) {
+ int mid = (lo + hi) / 2;
+ sector_t a = BB_OFFSET(p[mid]);
+
+ if (a < target)
+ /* This could still be the one, earlier ranges
+ * could not.
+ */
+ lo = mid;
+ else
+ /* This and later ranges are definitely out. */
+ hi = mid;
+ }
+ /* 'lo' might be the last that started before target, but 'hi' isn't */
+ if (hi > lo) {
+ /* need to check all range that end after 's' to see if
+ * any are unacknowledged.
+ */
+ while (lo >= 0 &&
+ BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
+ if (BB_OFFSET(p[lo]) < target) {
+ /* starts before the end, and finishes after
+ * the start, so they must overlap
+ */
+ if (rv != -1 && BB_ACK(p[lo]))
+ rv = 1;
+ else
+ rv = -1;
+ *first_bad = BB_OFFSET(p[lo]);
+ *bad_sectors = BB_LEN(p[lo]);
+ }
+ lo--;
+ }
+ }
+
+ if (read_seqretry(&bb->lock, seq))
+ goto retry;
+
+ return rv;
+}
+EXPORT_SYMBOL_GPL(badblocks_check);
+
+static void badblocks_update_acked(struct badblocks *bb)
+{
+ u64 *p = bb->page;
+ int i;
+ bool unacked = false;
+
+ if (!bb->unacked_exist)
+ return;
+
+ for (i = 0; i < bb->count ; i++) {
+ if (!BB_ACK(p[i])) {
+ unacked = true;
+ break;
+ }
+ }
+
+ if (!unacked)
+ bb->unacked_exist = 0;
+}
+
+/**
+ * badblocks_set() - Add a range of bad blocks to the table.
+ * @bb: the badblocks structure that holds all badblock information
+ * @s: first sector to mark as bad
+ * @sectors: number of sectors to mark as bad
+ * @acknowledged: weather to mark the bad sectors as acknowledged
+ *
+ * This might extend the table, or might contract it if two adjacent ranges
+ * can be merged. We binary-search to find the 'insertion' point, then
+ * decide how best to handle it.
+ *
+ * Return:
+ * 0: success
+ * 1: failed to set badblocks (out of space)
+ */
+int badblocks_set(struct badblocks *bb, sector_t s, int sectors,
+ int acknowledged)
+{
+ u64 *p;
+ int lo, hi;
+ int rv = 0;
+ unsigned long flags;
+
+ if (bb->shift < 0)
+ /* badblocks are disabled */
+ return 1;
+
+ if (bb->shift) {
+ /* round the start down, and the end up */
+ sector_t next = s + sectors;
+
+ s >>= bb->shift;
+ next += (1<<bb->shift) - 1;
+ next >>= bb->shift;
+ sectors = next - s;
+ }
+
+ write_seqlock_irqsave(&bb->lock, flags);
+
+ p = bb->page;
+ lo = 0;
+ hi = bb->count;
+ /* Find the last range that starts at-or-before 's' */
+ while (hi - lo > 1) {
+ int mid = (lo + hi) / 2;
+ sector_t a = BB_OFFSET(p[mid]);
+
+ if (a <= s)
+ lo = mid;
+ else
+ hi = mid;
+ }
+ if (hi > lo && BB_OFFSET(p[lo]) > s)
+ hi = lo;
+
+ if (hi > lo) {
+ /* we found a range that might merge with the start
+ * of our new range
+ */
+ sector_t a = BB_OFFSET(p[lo]);
+ sector_t e = a + BB_LEN(p[lo]);
+ int ack = BB_ACK(p[lo]);
+
+ if (e >= s) {
+ /* Yes, we can merge with a previous range */
+ if (s == a && s + sectors >= e)
+ /* new range covers old */
+ ack = acknowledged;
+ else
+ ack = ack && acknowledged;
+
+ if (e < s + sectors)
+ e = s + sectors;
+ if (e - a <= BB_MAX_LEN) {
+ p[lo] = BB_MAKE(a, e-a, ack);
+ s = e;
+ } else {
+ /* does not all fit in one range,
+ * make p[lo] maximal
+ */
+ if (BB_LEN(p[lo]) != BB_MAX_LEN)
+ p[lo] = BB_MAKE(a, BB_MAX_LEN, ack);
+ s = a + BB_MAX_LEN;
+ }
+ sectors = e - s;
+ }
+ }
+ if (sectors && hi < bb->count) {
+ /* 'hi' points to the first range that starts after 's'.
+ * Maybe we can merge with the start of that range
+ */
+ sector_t a = BB_OFFSET(p[hi]);
+ sector_t e = a + BB_LEN(p[hi]);
+ int ack = BB_ACK(p[hi]);
+
+ if (a <= s + sectors) {
+ /* merging is possible */
+ if (e <= s + sectors) {
+ /* full overlap */
+ e = s + sectors;
+ ack = acknowledged;
+ } else
+ ack = ack && acknowledged;
+
+ a = s;
+ if (e - a <= BB_MAX_LEN) {
+ p[hi] = BB_MAKE(a, e-a, ack);
+ s = e;
+ } else {
+ p[hi] = BB_MAKE(a, BB_MAX_LEN, ack);
+ s = a + BB_MAX_LEN;
+ }
+ sectors = e - s;
+ lo = hi;
+ hi++;
+ }
+ }
+ if (sectors == 0 && hi < bb->count) {
+ /* we might be able to combine lo and hi */
+ /* Note: 's' is at the end of 'lo' */
+ sector_t a = BB_OFFSET(p[hi]);
+ int lolen = BB_LEN(p[lo]);
+ int hilen = BB_LEN(p[hi]);
+ int newlen = lolen + hilen - (s - a);
+
+ if (s >= a && newlen < BB_MAX_LEN) {
+ /* yes, we can combine them */
+ int ack = BB_ACK(p[lo]) && BB_ACK(p[hi]);
+
+ p[lo] = BB_MAKE(BB_OFFSET(p[lo]), newlen, ack);
+ memmove(p + hi, p + hi + 1,
+ (bb->count - hi - 1) * 8);
+ bb->count--;
+ }
+ }
+ while (sectors) {
+ /* didn't merge (it all).
+ * Need to add a range just before 'hi'
+ */
+ if (bb->count >= MAX_BADBLOCKS) {
+ /* No room for more */
+ rv = 1;
+ break;
+ } else {
+ int this_sectors = sectors;
+
+ memmove(p + hi + 1, p + hi,
+ (bb->count - hi) * 8);
+ bb->count++;
+
+ if (this_sectors > BB_MAX_LEN)
+ this_sectors = BB_MAX_LEN;
+ p[hi] = BB_MAKE(s, this_sectors, acknowledged);
+ sectors -= this_sectors;
+ s += this_sectors;
+ }
+ }
+
+ bb->changed = 1;
+ if (!acknowledged)
+ bb->unacked_exist = 1;
+ else
+ badblocks_update_acked(bb);
+ write_sequnlock_irqrestore(&bb->lock, flags);
+
+ return rv;
+}
+EXPORT_SYMBOL_GPL(badblocks_set);
+
+/**
+ * badblocks_clear() - Remove a range of bad blocks to the table.
+ * @bb: the badblocks structure that holds all badblock information
+ * @s: first sector to mark as bad
+ * @sectors: number of sectors to mark as bad
+ *
+ * This may involve extending the table if we spilt a region,
+ * but it must not fail. So if the table becomes full, we just
+ * drop the remove request.
+ *
+ * Return:
+ * 0: success
+ * 1: failed to clear badblocks
+ */
+int badblocks_clear(struct badblocks *bb, sector_t s, int sectors)
+{
+ u64 *p;
+ int lo, hi;
+ sector_t target = s + sectors;
+ int rv = 0;
+
+ if (bb->shift > 0) {
+ /* When clearing we round the start up and the end down.
+ * This should not matter as the shift should align with
+ * the block size and no rounding should ever be needed.
+ * However it is better the think a block is bad when it
+ * isn't than to think a block is not bad when it is.
+ */
+ s += (1<<bb->shift) - 1;
+ s >>= bb->shift;
+ target >>= bb->shift;
+ sectors = target - s;
+ }
+
+ write_seqlock_irq(&bb->lock);
+
+ p = bb->page;
+ lo = 0;
+ hi = bb->count;
+ /* Find the last range that starts before 'target' */
+ while (hi - lo > 1) {
+ int mid = (lo + hi) / 2;
+ sector_t a = BB_OFFSET(p[mid]);
+
+ if (a < target)
+ lo = mid;
+ else
+ hi = mid;
+ }
+ if (hi > lo) {
+ /* p[lo] is the last range that could overlap the
+ * current range. Earlier ranges could also overlap,
+ * but only this one can overlap the end of the range.
+ */
+ if ((BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > target) &&
+ (BB_OFFSET(p[lo]) < target)) {
+ /* Partial overlap, leave the tail of this range */
+ int ack = BB_ACK(p[lo]);
+ sector_t a = BB_OFFSET(p[lo]);
+ sector_t end = a + BB_LEN(p[lo]);
+
+ if (a < s) {
+ /* we need to split this range */
+ if (bb->count >= MAX_BADBLOCKS) {
+ rv = -ENOSPC;
+ goto out;
+ }
+ memmove(p+lo+1, p+lo, (bb->count - lo) * 8);
+ bb->count++;
+ p[lo] = BB_MAKE(a, s-a, ack);
+ lo++;
+ }
+ p[lo] = BB_MAKE(target, end - target, ack);
+ /* there is no longer an overlap */
+ hi = lo;
+ lo--;
+ }
+ while (lo >= 0 &&
+ (BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) &&
+ (BB_OFFSET(p[lo]) < target)) {
+ /* This range does overlap */
+ if (BB_OFFSET(p[lo]) < s) {
+ /* Keep the early parts of this range. */
+ int ack = BB_ACK(p[lo]);
+ sector_t start = BB_OFFSET(p[lo]);
+
+ p[lo] = BB_MAKE(start, s - start, ack);
+ /* now low doesn't overlap, so.. */
+ break;
+ }
+ lo--;
+ }
+ /* 'lo' is strictly before, 'hi' is strictly after,
+ * anything between needs to be discarded
+ */
+ if (hi - lo > 1) {
+ memmove(p+lo+1, p+hi, (bb->count - hi) * 8);
+ bb->count -= (hi - lo - 1);
+ }
+ }
+
+ badblocks_update_acked(bb);
+ bb->changed = 1;
+out:
+ write_sequnlock_irq(&bb->lock);
+ return rv;
+}
+EXPORT_SYMBOL_GPL(badblocks_clear);
+
+/**
+ * ack_all_badblocks() - Acknowledge all bad blocks in a list.
+ * @bb: the badblocks structure that holds all badblock information
+ *
+ * This only succeeds if ->changed is clear. It is used by
+ * in-kernel metadata updates
+ */
+void ack_all_badblocks(struct badblocks *bb)
+{
+ if (bb->page == NULL || bb->changed)
+ /* no point even trying */
+ return;
+ write_seqlock_irq(&bb->lock);
+
+ if (bb->changed == 0 && bb->unacked_exist) {
+ u64 *p = bb->page;
+ int i;
+
+ for (i = 0; i < bb->count ; i++) {
+ if (!BB_ACK(p[i])) {
+ sector_t start = BB_OFFSET(p[i]);
+ int len = BB_LEN(p[i]);
+
+ p[i] = BB_MAKE(start, len, 1);
+ }
+ }
+ bb->unacked_exist = 0;
+ }
+ write_sequnlock_irq(&bb->lock);
+}
+EXPORT_SYMBOL_GPL(ack_all_badblocks);
+
+/**
+ * badblocks_show() - sysfs access to bad-blocks list
+ * @bb: the badblocks structure that holds all badblock information
+ * @page: buffer received from sysfs
+ * @unack: weather to show unacknowledged badblocks
+ *
+ * Return:
+ * Length of returned data
+ */
+ssize_t badblocks_show(struct badblocks *bb, char *page, int unack)
+{
+ size_t len;
+ int i;
+ u64 *p = bb->page;
+ unsigned seq;
+
+ if (bb->shift < 0)
+ return 0;
+
+retry:
+ seq = read_seqbegin(&bb->lock);
+
+ len = 0;
+ i = 0;
+
+ while (len < PAGE_SIZE && i < bb->count) {
+ sector_t s = BB_OFFSET(p[i]);
+ unsigned int length = BB_LEN(p[i]);
+ int ack = BB_ACK(p[i]);
+
+ i++;
+
+ if (unack && ack)
+ continue;
+
+ len += snprintf(page+len, PAGE_SIZE-len, "%llu %u\n",
+ (unsigned long long)s << bb->shift,
+ length << bb->shift);
+ }
+ if (unack && len == 0)
+ bb->unacked_exist = 0;
+
+ if (read_seqretry(&bb->lock, seq))
+ goto retry;
+
+ return len;
+}
+EXPORT_SYMBOL_GPL(badblocks_show);
+
+/**
+ * badblocks_store() - sysfs access to bad-blocks list
+ * @bb: the badblocks structure that holds all badblock information
+ * @page: buffer received from sysfs
+ * @len: length of data received from sysfs
+ * @unack: weather to show unacknowledged badblocks
+ *
+ * Return:
+ * Length of the buffer processed or -ve error.
+ */
+ssize_t badblocks_store(struct badblocks *bb, const char *page, size_t len,
+ int unack)
+{
+ unsigned long long sector;
+ int length;
+ char newline;
+
+ switch (sscanf(page, "%llu %d%c", §or, &length, &newline)) {
+ case 3:
+ if (newline != '\n')
+ return -EINVAL;
+ /* fall through */
+ case 2:
+ if (length <= 0)
+ return -EINVAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (badblocks_set(bb, sector, length, !unack))
+ return -ENOSPC;
+ else
+ return len;
+}
+EXPORT_SYMBOL_GPL(badblocks_store);
+
+static int __badblocks_init(struct device *dev, struct badblocks *bb,
+ int enable)
+{
+ bb->dev = dev;
+ bb->count = 0;
+ if (enable)
+ bb->shift = 0;
+ else
+ bb->shift = -1;
+ if (dev)
+ bb->page = devm_kzalloc(dev, PAGE_SIZE, GFP_KERNEL);
+ else
+ bb->page = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!bb->page) {
+ bb->shift = -1;
+ return -ENOMEM;
+ }
+ seqlock_init(&bb->lock);
+
+ return 0;
+}
+
+/**
+ * badblocks_init() - initialize the badblocks structure
+ * @bb: the badblocks structure that holds all badblock information
+ * @enable: weather to enable badblocks accounting
+ *
+ * Return:
+ * 0: success
+ * -ve errno: on error
+ */
+int badblocks_init(struct badblocks *bb, int enable)
+{
+ return __badblocks_init(NULL, bb, enable);
+}
+EXPORT_SYMBOL_GPL(badblocks_init);
+
+int devm_init_badblocks(struct device *dev, struct badblocks *bb)
+{
+ if (!bb)
+ return -EINVAL;
+ return __badblocks_init(dev, bb, 1);
+}
+EXPORT_SYMBOL_GPL(devm_init_badblocks);
+
+/**
+ * badblocks_exit() - free the badblocks structure
+ * @bb: the badblocks structure that holds all badblock information
+ */
+void badblocks_exit(struct badblocks *bb)
+{
+ if (!bb)
+ return;
+ if (bb->dev)
+ devm_kfree(bb->dev, bb->page);
+ else
+ kfree(bb->page);
+ bb->page = NULL;
+}
+EXPORT_SYMBOL_GPL(badblocks_exit);
diff --git a/src/kernel/linux/v4.14/block/bfq-cgroup.c b/src/kernel/linux/v4.14/block/bfq-cgroup.c
new file mode 100644
index 0000000..7d7aee0
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/bfq-cgroup.c
@@ -0,0 +1,1214 @@
+/*
+ * cgroups support for the BFQ I/O scheduler.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/cgroup.h>
+#include <linux/elevator.h>
+#include <linux/ktime.h>
+#include <linux/rbtree.h>
+#include <linux/ioprio.h>
+#include <linux/sbitmap.h>
+#include <linux/delay.h>
+
+#include "bfq-iosched.h"
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+
+/* bfqg stats flags */
+enum bfqg_stats_flags {
+ BFQG_stats_waiting = 0,
+ BFQG_stats_idling,
+ BFQG_stats_empty,
+};
+
+#define BFQG_FLAG_FNS(name) \
+static void bfqg_stats_mark_##name(struct bfqg_stats *stats) \
+{ \
+ stats->flags |= (1 << BFQG_stats_##name); \
+} \
+static void bfqg_stats_clear_##name(struct bfqg_stats *stats) \
+{ \
+ stats->flags &= ~(1 << BFQG_stats_##name); \
+} \
+static int bfqg_stats_##name(struct bfqg_stats *stats) \
+{ \
+ return (stats->flags & (1 << BFQG_stats_##name)) != 0; \
+} \
+
+BFQG_FLAG_FNS(waiting)
+BFQG_FLAG_FNS(idling)
+BFQG_FLAG_FNS(empty)
+#undef BFQG_FLAG_FNS
+
+/* This should be called with the scheduler lock held. */
+static void bfqg_stats_update_group_wait_time(struct bfqg_stats *stats)
+{
+ unsigned long long now;
+
+ if (!bfqg_stats_waiting(stats))
+ return;
+
+ now = sched_clock();
+ if (time_after64(now, stats->start_group_wait_time))
+ blkg_stat_add(&stats->group_wait_time,
+ now - stats->start_group_wait_time);
+ bfqg_stats_clear_waiting(stats);
+}
+
+/* This should be called with the scheduler lock held. */
+static void bfqg_stats_set_start_group_wait_time(struct bfq_group *bfqg,
+ struct bfq_group *curr_bfqg)
+{
+ struct bfqg_stats *stats = &bfqg->stats;
+
+ if (bfqg_stats_waiting(stats))
+ return;
+ if (bfqg == curr_bfqg)
+ return;
+ stats->start_group_wait_time = sched_clock();
+ bfqg_stats_mark_waiting(stats);
+}
+
+/* This should be called with the scheduler lock held. */
+static void bfqg_stats_end_empty_time(struct bfqg_stats *stats)
+{
+ unsigned long long now;
+
+ if (!bfqg_stats_empty(stats))
+ return;
+
+ now = sched_clock();
+ if (time_after64(now, stats->start_empty_time))
+ blkg_stat_add(&stats->empty_time,
+ now - stats->start_empty_time);
+ bfqg_stats_clear_empty(stats);
+}
+
+void bfqg_stats_update_dequeue(struct bfq_group *bfqg)
+{
+ blkg_stat_add(&bfqg->stats.dequeue, 1);
+}
+
+void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg)
+{
+ struct bfqg_stats *stats = &bfqg->stats;
+
+ if (blkg_rwstat_total(&stats->queued))
+ return;
+
+ /*
+ * group is already marked empty. This can happen if bfqq got new
+ * request in parent group and moved to this group while being added
+ * to service tree. Just ignore the event and move on.
+ */
+ if (bfqg_stats_empty(stats))
+ return;
+
+ stats->start_empty_time = sched_clock();
+ bfqg_stats_mark_empty(stats);
+}
+
+void bfqg_stats_update_idle_time(struct bfq_group *bfqg)
+{
+ struct bfqg_stats *stats = &bfqg->stats;
+
+ if (bfqg_stats_idling(stats)) {
+ unsigned long long now = sched_clock();
+
+ if (time_after64(now, stats->start_idle_time))
+ blkg_stat_add(&stats->idle_time,
+ now - stats->start_idle_time);
+ bfqg_stats_clear_idling(stats);
+ }
+}
+
+void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg)
+{
+ struct bfqg_stats *stats = &bfqg->stats;
+
+ stats->start_idle_time = sched_clock();
+ bfqg_stats_mark_idling(stats);
+}
+
+void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg)
+{
+ struct bfqg_stats *stats = &bfqg->stats;
+
+ blkg_stat_add(&stats->avg_queue_size_sum,
+ blkg_rwstat_total(&stats->queued));
+ blkg_stat_add(&stats->avg_queue_size_samples, 1);
+ bfqg_stats_update_group_wait_time(stats);
+}
+
+/*
+ * blk-cgroup policy-related handlers
+ * The following functions help in converting between blk-cgroup
+ * internal structures and BFQ-specific structures.
+ */
+
+static struct bfq_group *pd_to_bfqg(struct blkg_policy_data *pd)
+{
+ return pd ? container_of(pd, struct bfq_group, pd) : NULL;
+}
+
+struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg)
+{
+ return pd_to_blkg(&bfqg->pd);
+}
+
+static struct bfq_group *blkg_to_bfqg(struct blkcg_gq *blkg)
+{
+ return pd_to_bfqg(blkg_to_pd(blkg, &blkcg_policy_bfq));
+}
+
+/*
+ * bfq_group handlers
+ * The following functions help in navigating the bfq_group hierarchy
+ * by allowing to find the parent of a bfq_group or the bfq_group
+ * associated to a bfq_queue.
+ */
+
+static struct bfq_group *bfqg_parent(struct bfq_group *bfqg)
+{
+ struct blkcg_gq *pblkg = bfqg_to_blkg(bfqg)->parent;
+
+ return pblkg ? blkg_to_bfqg(pblkg) : NULL;
+}
+
+struct bfq_group *bfqq_group(struct bfq_queue *bfqq)
+{
+ struct bfq_entity *group_entity = bfqq->entity.parent;
+
+ return group_entity ? container_of(group_entity, struct bfq_group,
+ entity) :
+ bfqq->bfqd->root_group;
+}
+
+/*
+ * The following two functions handle get and put of a bfq_group by
+ * wrapping the related blk-cgroup hooks.
+ */
+
+static void bfqg_get(struct bfq_group *bfqg)
+{
+ bfqg->ref++;
+}
+
+static void bfqg_put(struct bfq_group *bfqg)
+{
+ bfqg->ref--;
+
+ if (bfqg->ref == 0)
+ kfree(bfqg);
+}
+
+static void bfqg_and_blkg_get(struct bfq_group *bfqg)
+{
+ /* see comments in bfq_bic_update_cgroup for why refcounting bfqg */
+ bfqg_get(bfqg);
+
+ blkg_get(bfqg_to_blkg(bfqg));
+}
+
+void bfqg_and_blkg_put(struct bfq_group *bfqg)
+{
+ blkg_put(bfqg_to_blkg(bfqg));
+
+ bfqg_put(bfqg);
+}
+
+void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq,
+ unsigned int op)
+{
+ blkg_rwstat_add(&bfqg->stats.queued, op, 1);
+ bfqg_stats_end_empty_time(&bfqg->stats);
+ if (!(bfqq == ((struct bfq_data *)bfqg->bfqd)->in_service_queue))
+ bfqg_stats_set_start_group_wait_time(bfqg, bfqq_group(bfqq));
+}
+
+void bfqg_stats_update_io_remove(struct bfq_group *bfqg, unsigned int op)
+{
+ blkg_rwstat_add(&bfqg->stats.queued, op, -1);
+}
+
+void bfqg_stats_update_io_merged(struct bfq_group *bfqg, unsigned int op)
+{
+ blkg_rwstat_add(&bfqg->stats.merged, op, 1);
+}
+
+void bfqg_stats_update_completion(struct bfq_group *bfqg, uint64_t start_time,
+ uint64_t io_start_time, unsigned int op)
+{
+ struct bfqg_stats *stats = &bfqg->stats;
+ unsigned long long now = sched_clock();
+
+ if (time_after64(now, io_start_time))
+ blkg_rwstat_add(&stats->service_time, op,
+ now - io_start_time);
+ if (time_after64(io_start_time, start_time))
+ blkg_rwstat_add(&stats->wait_time, op,
+ io_start_time - start_time);
+}
+
+/* @stats = 0 */
+static void bfqg_stats_reset(struct bfqg_stats *stats)
+{
+ /* queued stats shouldn't be cleared */
+ blkg_rwstat_reset(&stats->merged);
+ blkg_rwstat_reset(&stats->service_time);
+ blkg_rwstat_reset(&stats->wait_time);
+ blkg_stat_reset(&stats->time);
+ blkg_stat_reset(&stats->avg_queue_size_sum);
+ blkg_stat_reset(&stats->avg_queue_size_samples);
+ blkg_stat_reset(&stats->dequeue);
+ blkg_stat_reset(&stats->group_wait_time);
+ blkg_stat_reset(&stats->idle_time);
+ blkg_stat_reset(&stats->empty_time);
+}
+
+/* @to += @from */
+static void bfqg_stats_add_aux(struct bfqg_stats *to, struct bfqg_stats *from)
+{
+ if (!to || !from)
+ return;
+
+ /* queued stats shouldn't be cleared */
+ blkg_rwstat_add_aux(&to->merged, &from->merged);
+ blkg_rwstat_add_aux(&to->service_time, &from->service_time);
+ blkg_rwstat_add_aux(&to->wait_time, &from->wait_time);
+ blkg_stat_add_aux(&from->time, &from->time);
+ blkg_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
+ blkg_stat_add_aux(&to->avg_queue_size_samples,
+ &from->avg_queue_size_samples);
+ blkg_stat_add_aux(&to->dequeue, &from->dequeue);
+ blkg_stat_add_aux(&to->group_wait_time, &from->group_wait_time);
+ blkg_stat_add_aux(&to->idle_time, &from->idle_time);
+ blkg_stat_add_aux(&to->empty_time, &from->empty_time);
+}
+
+/*
+ * Transfer @bfqg's stats to its parent's aux counts so that the ancestors'
+ * recursive stats can still account for the amount used by this bfqg after
+ * it's gone.
+ */
+static void bfqg_stats_xfer_dead(struct bfq_group *bfqg)
+{
+ struct bfq_group *parent;
+
+ if (!bfqg) /* root_group */
+ return;
+
+ parent = bfqg_parent(bfqg);
+
+ lockdep_assert_held(bfqg_to_blkg(bfqg)->q->queue_lock);
+
+ if (unlikely(!parent))
+ return;
+
+ bfqg_stats_add_aux(&parent->stats, &bfqg->stats);
+ bfqg_stats_reset(&bfqg->stats);
+}
+
+void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+
+ entity->weight = entity->new_weight;
+ entity->orig_weight = entity->new_weight;
+ if (bfqq) {
+ bfqq->ioprio = bfqq->new_ioprio;
+ bfqq->ioprio_class = bfqq->new_ioprio_class;
+ /*
+ * Make sure that bfqg and its associated blkg do not
+ * disappear before entity.
+ */
+ bfqg_and_blkg_get(bfqg);
+ }
+ entity->parent = bfqg->my_entity; /* NULL for root group */
+ entity->sched_data = &bfqg->sched_data;
+}
+
+static void bfqg_stats_exit(struct bfqg_stats *stats)
+{
+ blkg_rwstat_exit(&stats->merged);
+ blkg_rwstat_exit(&stats->service_time);
+ blkg_rwstat_exit(&stats->wait_time);
+ blkg_rwstat_exit(&stats->queued);
+ blkg_stat_exit(&stats->time);
+ blkg_stat_exit(&stats->avg_queue_size_sum);
+ blkg_stat_exit(&stats->avg_queue_size_samples);
+ blkg_stat_exit(&stats->dequeue);
+ blkg_stat_exit(&stats->group_wait_time);
+ blkg_stat_exit(&stats->idle_time);
+ blkg_stat_exit(&stats->empty_time);
+}
+
+static int bfqg_stats_init(struct bfqg_stats *stats, gfp_t gfp)
+{
+ if (blkg_rwstat_init(&stats->merged, gfp) ||
+ blkg_rwstat_init(&stats->service_time, gfp) ||
+ blkg_rwstat_init(&stats->wait_time, gfp) ||
+ blkg_rwstat_init(&stats->queued, gfp) ||
+ blkg_stat_init(&stats->time, gfp) ||
+ blkg_stat_init(&stats->avg_queue_size_sum, gfp) ||
+ blkg_stat_init(&stats->avg_queue_size_samples, gfp) ||
+ blkg_stat_init(&stats->dequeue, gfp) ||
+ blkg_stat_init(&stats->group_wait_time, gfp) ||
+ blkg_stat_init(&stats->idle_time, gfp) ||
+ blkg_stat_init(&stats->empty_time, gfp)) {
+ bfqg_stats_exit(stats);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static struct bfq_group_data *cpd_to_bfqgd(struct blkcg_policy_data *cpd)
+{
+ return cpd ? container_of(cpd, struct bfq_group_data, pd) : NULL;
+}
+
+static struct bfq_group_data *blkcg_to_bfqgd(struct blkcg *blkcg)
+{
+ return cpd_to_bfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_bfq));
+}
+
+static struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp)
+{
+ struct bfq_group_data *bgd;
+
+ bgd = kzalloc(sizeof(*bgd), gfp);
+ if (!bgd)
+ return NULL;
+ return &bgd->pd;
+}
+
+static void bfq_cpd_init(struct blkcg_policy_data *cpd)
+{
+ struct bfq_group_data *d = cpd_to_bfqgd(cpd);
+
+ d->weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ?
+ CGROUP_WEIGHT_DFL : BFQ_WEIGHT_LEGACY_DFL;
+}
+
+static void bfq_cpd_free(struct blkcg_policy_data *cpd)
+{
+ kfree(cpd_to_bfqgd(cpd));
+}
+
+static struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, int node)
+{
+ struct bfq_group *bfqg;
+
+ bfqg = kzalloc_node(sizeof(*bfqg), gfp, node);
+ if (!bfqg)
+ return NULL;
+
+ if (bfqg_stats_init(&bfqg->stats, gfp)) {
+ kfree(bfqg);
+ return NULL;
+ }
+
+ /* see comments in bfq_bic_update_cgroup for why refcounting */
+ bfqg_get(bfqg);
+ return &bfqg->pd;
+}
+
+static void bfq_pd_init(struct blkg_policy_data *pd)
+{
+ struct blkcg_gq *blkg = pd_to_blkg(pd);
+ struct bfq_group *bfqg = blkg_to_bfqg(blkg);
+ struct bfq_data *bfqd = blkg->q->elevator->elevator_data;
+ struct bfq_entity *entity = &bfqg->entity;
+ struct bfq_group_data *d = blkcg_to_bfqgd(blkg->blkcg);
+
+ entity->orig_weight = entity->weight = entity->new_weight = d->weight;
+ entity->my_sched_data = &bfqg->sched_data;
+ bfqg->my_entity = entity; /*
+ * the root_group's will be set to NULL
+ * in bfq_init_queue()
+ */
+ bfqg->bfqd = bfqd;
+ bfqg->active_entities = 0;
+ bfqg->rq_pos_tree = RB_ROOT;
+}
+
+static void bfq_pd_free(struct blkg_policy_data *pd)
+{
+ struct bfq_group *bfqg = pd_to_bfqg(pd);
+
+ bfqg_stats_exit(&bfqg->stats);
+ bfqg_put(bfqg);
+}
+
+static void bfq_pd_reset_stats(struct blkg_policy_data *pd)
+{
+ struct bfq_group *bfqg = pd_to_bfqg(pd);
+
+ bfqg_stats_reset(&bfqg->stats);
+}
+
+static void bfq_group_set_parent(struct bfq_group *bfqg,
+ struct bfq_group *parent)
+{
+ struct bfq_entity *entity;
+
+ entity = &bfqg->entity;
+ entity->parent = parent->my_entity;
+ entity->sched_data = &parent->sched_data;
+}
+
+static struct bfq_group *bfq_lookup_bfqg(struct bfq_data *bfqd,
+ struct blkcg *blkcg)
+{
+ struct blkcg_gq *blkg;
+
+ blkg = blkg_lookup(blkcg, bfqd->queue);
+ if (likely(blkg))
+ return blkg_to_bfqg(blkg);
+ return NULL;
+}
+
+struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd,
+ struct blkcg *blkcg)
+{
+ struct bfq_group *bfqg, *parent;
+ struct bfq_entity *entity;
+
+ bfqg = bfq_lookup_bfqg(bfqd, blkcg);
+
+ if (unlikely(!bfqg))
+ return NULL;
+
+ /*
+ * Update chain of bfq_groups as we might be handling a leaf group
+ * which, along with some of its relatives, has not been hooked yet
+ * to the private hierarchy of BFQ.
+ */
+ entity = &bfqg->entity;
+ for_each_entity(entity) {
+ struct bfq_group *curr_bfqg = container_of(entity,
+ struct bfq_group, entity);
+ if (curr_bfqg != bfqd->root_group) {
+ parent = bfqg_parent(curr_bfqg);
+ if (!parent)
+ parent = bfqd->root_group;
+ bfq_group_set_parent(curr_bfqg, parent);
+ }
+ }
+
+ return bfqg;
+}
+
+/**
+ * bfq_bfqq_move - migrate @bfqq to @bfqg.
+ * @bfqd: queue descriptor.
+ * @bfqq: the queue to move.
+ * @bfqg: the group to move to.
+ *
+ * Move @bfqq to @bfqg, deactivating it from its old group and reactivating
+ * it on the new one. Avoid putting the entity on the old group idle tree.
+ *
+ * Must be called under the scheduler lock, to make sure that the blkg
+ * owning @bfqg does not disappear (see comments in
+ * bfq_bic_update_cgroup on guaranteeing the consistency of blkg
+ * objects).
+ */
+void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ struct bfq_group *bfqg)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+
+ /* If bfqq is empty, then bfq_bfqq_expire also invokes
+ * bfq_del_bfqq_busy, thereby removing bfqq and its entity
+ * from data structures related to current group. Otherwise we
+ * need to remove bfqq explicitly with bfq_deactivate_bfqq, as
+ * we do below.
+ */
+ if (bfqq == bfqd->in_service_queue)
+ bfq_bfqq_expire(bfqd, bfqd->in_service_queue,
+ false, BFQQE_PREEMPTED);
+
+ if (bfq_bfqq_busy(bfqq))
+ bfq_deactivate_bfqq(bfqd, bfqq, false, false);
+ else if (entity->on_st)
+ bfq_put_idle_entity(bfq_entity_service_tree(entity), entity);
+ bfqg_and_blkg_put(bfqq_group(bfqq));
+
+ entity->parent = bfqg->my_entity;
+ entity->sched_data = &bfqg->sched_data;
+ /* pin down bfqg and its associated blkg */
+ bfqg_and_blkg_get(bfqg);
+
+ if (bfq_bfqq_busy(bfqq)) {
+ bfq_pos_tree_add_move(bfqd, bfqq);
+ bfq_activate_bfqq(bfqd, bfqq);
+ }
+
+ if (!bfqd->in_service_queue && !bfqd->rq_in_driver)
+ bfq_schedule_dispatch(bfqd);
+}
+
+/**
+ * __bfq_bic_change_cgroup - move @bic to @cgroup.
+ * @bfqd: the queue descriptor.
+ * @bic: the bic to move.
+ * @blkcg: the blk-cgroup to move to.
+ *
+ * Move bic to blkcg, assuming that bfqd->lock is held; which makes
+ * sure that the reference to cgroup is valid across the call (see
+ * comments in bfq_bic_update_cgroup on this issue)
+ *
+ * NOTE: an alternative approach might have been to store the current
+ * cgroup in bfqq and getting a reference to it, reducing the lookup
+ * time here, at the price of slightly more complex code.
+ */
+static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd,
+ struct bfq_io_cq *bic,
+ struct blkcg *blkcg)
+{
+ struct bfq_queue *async_bfqq = bic_to_bfqq(bic, 0);
+ struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, 1);
+ struct bfq_group *bfqg;
+ struct bfq_entity *entity;
+
+ bfqg = bfq_find_set_group(bfqd, blkcg);
+
+ if (unlikely(!bfqg))
+ bfqg = bfqd->root_group;
+
+ if (async_bfqq) {
+ entity = &async_bfqq->entity;
+
+ if (entity->sched_data != &bfqg->sched_data) {
+ bic_set_bfqq(bic, NULL, 0);
+ bfq_log_bfqq(bfqd, async_bfqq,
+ "bic_change_group: %p %d",
+ async_bfqq, async_bfqq->ref);
+ bfq_put_queue(async_bfqq);
+ }
+ }
+
+ if (sync_bfqq) {
+ entity = &sync_bfqq->entity;
+ if (entity->sched_data != &bfqg->sched_data)
+ bfq_bfqq_move(bfqd, sync_bfqq, bfqg);
+ }
+
+ return bfqg;
+}
+
+void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio)
+{
+ struct bfq_data *bfqd = bic_to_bfqd(bic);
+ struct bfq_group *bfqg = NULL;
+ uint64_t serial_nr;
+
+ rcu_read_lock();
+ serial_nr = bio_blkcg(bio)->css.serial_nr;
+
+ /*
+ * Check whether blkcg has changed. The condition may trigger
+ * spuriously on a newly created cic but there's no harm.
+ */
+ if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr))
+ goto out;
+
+ bfqg = __bfq_bic_change_cgroup(bfqd, bic, bio_blkcg(bio));
+ /*
+ * Update blkg_path for bfq_log_* functions. We cache this
+ * path, and update it here, for the following
+ * reasons. Operations on blkg objects in blk-cgroup are
+ * protected with the request_queue lock, and not with the
+ * lock that protects the instances of this scheduler
+ * (bfqd->lock). This exposes BFQ to the following sort of
+ * race.
+ *
+ * The blkg_lookup performed in bfq_get_queue, protected
+ * through rcu, may happen to return the address of a copy of
+ * the original blkg. If this is the case, then the
+ * bfqg_and_blkg_get performed in bfq_get_queue, to pin down
+ * the blkg, is useless: it does not prevent blk-cgroup code
+ * from destroying both the original blkg and all objects
+ * directly or indirectly referred by the copy of the
+ * blkg.
+ *
+ * On the bright side, destroy operations on a blkg invoke, as
+ * a first step, hooks of the scheduler associated with the
+ * blkg. And these hooks are executed with bfqd->lock held for
+ * BFQ. As a consequence, for any blkg associated with the
+ * request queue this instance of the scheduler is attached
+ * to, we are guaranteed that such a blkg is not destroyed, and
+ * that all the pointers it contains are consistent, while we
+ * are holding bfqd->lock. A blkg_lookup performed with
+ * bfqd->lock held then returns a fully consistent blkg, which
+ * remains consistent until this lock is held.
+ *
+ * Thanks to the last fact, and to the fact that: (1) bfqg has
+ * been obtained through a blkg_lookup in the above
+ * assignment, and (2) bfqd->lock is being held, here we can
+ * safely use the policy data for the involved blkg (i.e., the
+ * field bfqg->pd) to get to the blkg associated with bfqg,
+ * and then we can safely use any field of blkg. After we
+ * release bfqd->lock, even just getting blkg through this
+ * bfqg may cause dangling references to be traversed, as
+ * bfqg->pd may not exist any more.
+ *
+ * In view of the above facts, here we cache, in the bfqg, any
+ * blkg data we may need for this bic, and for its associated
+ * bfq_queue. As of now, we need to cache only the path of the
+ * blkg, which is used in the bfq_log_* functions.
+ *
+ * Finally, note that bfqg itself needs to be protected from
+ * destruction on the blkg_free of the original blkg (which
+ * invokes bfq_pd_free). We use an additional private
+ * refcounter for bfqg, to let it disappear only after no
+ * bfq_queue refers to it any longer.
+ */
+ blkg_path(bfqg_to_blkg(bfqg), bfqg->blkg_path, sizeof(bfqg->blkg_path));
+ bic->blkcg_serial_nr = serial_nr;
+out:
+ rcu_read_unlock();
+}
+
+/**
+ * bfq_flush_idle_tree - deactivate any entity on the idle tree of @st.
+ * @st: the service tree being flushed.
+ */
+static void bfq_flush_idle_tree(struct bfq_service_tree *st)
+{
+ struct bfq_entity *entity = st->first_idle;
+
+ for (; entity ; entity = st->first_idle)
+ __bfq_deactivate_entity(entity, false);
+}
+
+/**
+ * bfq_reparent_leaf_entity - move leaf entity to the root_group.
+ * @bfqd: the device data structure with the root group.
+ * @entity: the entity to move.
+ */
+static void bfq_reparent_leaf_entity(struct bfq_data *bfqd,
+ struct bfq_entity *entity)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+
+ bfq_bfqq_move(bfqd, bfqq, bfqd->root_group);
+}
+
+/**
+ * bfq_reparent_active_entities - move to the root group all active
+ * entities.
+ * @bfqd: the device data structure with the root group.
+ * @bfqg: the group to move from.
+ * @st: the service tree with the entities.
+ */
+static void bfq_reparent_active_entities(struct bfq_data *bfqd,
+ struct bfq_group *bfqg,
+ struct bfq_service_tree *st)
+{
+ struct rb_root *active = &st->active;
+ struct bfq_entity *entity = NULL;
+
+ if (!RB_EMPTY_ROOT(&st->active))
+ entity = bfq_entity_of(rb_first(active));
+
+ for (; entity ; entity = bfq_entity_of(rb_first(active)))
+ bfq_reparent_leaf_entity(bfqd, entity);
+
+ if (bfqg->sched_data.in_service_entity)
+ bfq_reparent_leaf_entity(bfqd,
+ bfqg->sched_data.in_service_entity);
+}
+
+/**
+ * bfq_pd_offline - deactivate the entity associated with @pd,
+ * and reparent its children entities.
+ * @pd: descriptor of the policy going offline.
+ *
+ * blkio already grabs the queue_lock for us, so no need to use
+ * RCU-based magic
+ */
+static void bfq_pd_offline(struct blkg_policy_data *pd)
+{
+ struct bfq_service_tree *st;
+ struct bfq_group *bfqg = pd_to_bfqg(pd);
+ struct bfq_data *bfqd = bfqg->bfqd;
+ struct bfq_entity *entity = bfqg->my_entity;
+ unsigned long flags;
+ int i;
+
+ spin_lock_irqsave(&bfqd->lock, flags);
+
+ if (!entity) /* root group */
+ goto put_async_queues;
+
+ /*
+ * Empty all service_trees belonging to this group before
+ * deactivating the group itself.
+ */
+ for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) {
+ st = bfqg->sched_data.service_tree + i;
+
+ /*
+ * The idle tree may still contain bfq_queues belonging
+ * to exited task because they never migrated to a different
+ * cgroup from the one being destroyed now.
+ */
+ bfq_flush_idle_tree(st);
+
+ /*
+ * It may happen that some queues are still active
+ * (busy) upon group destruction (if the corresponding
+ * processes have been forced to terminate). We move
+ * all the leaf entities corresponding to these queues
+ * to the root_group.
+ * Also, it may happen that the group has an entity
+ * in service, which is disconnected from the active
+ * tree: it must be moved, too.
+ * There is no need to put the sync queues, as the
+ * scheduler has taken no reference.
+ */
+ bfq_reparent_active_entities(bfqd, bfqg, st);
+ }
+
+ __bfq_deactivate_entity(entity, false);
+
+put_async_queues:
+ bfq_put_async_queues(bfqd, bfqg);
+
+ spin_unlock_irqrestore(&bfqd->lock, flags);
+ /*
+ * @blkg is going offline and will be ignored by
+ * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so
+ * that they don't get lost. If IOs complete after this point, the
+ * stats for them will be lost. Oh well...
+ */
+ bfqg_stats_xfer_dead(bfqg);
+}
+
+void bfq_end_wr_async(struct bfq_data *bfqd)
+{
+ struct blkcg_gq *blkg;
+
+ list_for_each_entry(blkg, &bfqd->queue->blkg_list, q_node) {
+ struct bfq_group *bfqg = blkg_to_bfqg(blkg);
+
+ bfq_end_wr_async_queues(bfqd, bfqg);
+ }
+ bfq_end_wr_async_queues(bfqd, bfqd->root_group);
+}
+
+static int bfq_io_show_weight(struct seq_file *sf, void *v)
+{
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
+ unsigned int val = 0;
+
+ if (bfqgd)
+ val = bfqgd->weight;
+
+ seq_printf(sf, "%u\n", val);
+
+ return 0;
+}
+
+static int bfq_io_set_weight_legacy(struct cgroup_subsys_state *css,
+ struct cftype *cftype,
+ u64 val)
+{
+ struct blkcg *blkcg = css_to_blkcg(css);
+ struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
+ struct blkcg_gq *blkg;
+ int ret = -ERANGE;
+
+ if (val < BFQ_MIN_WEIGHT || val > BFQ_MAX_WEIGHT)
+ return ret;
+
+ ret = 0;
+ spin_lock_irq(&blkcg->lock);
+ bfqgd->weight = (unsigned short)val;
+ hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
+ struct bfq_group *bfqg = blkg_to_bfqg(blkg);
+
+ if (!bfqg)
+ continue;
+ /*
+ * Setting the prio_changed flag of the entity
+ * to 1 with new_weight == weight would re-set
+ * the value of the weight to its ioprio mapping.
+ * Set the flag only if necessary.
+ */
+ if ((unsigned short)val != bfqg->entity.new_weight) {
+ bfqg->entity.new_weight = (unsigned short)val;
+ /*
+ * Make sure that the above new value has been
+ * stored in bfqg->entity.new_weight before
+ * setting the prio_changed flag. In fact,
+ * this flag may be read asynchronously (in
+ * critical sections protected by a different
+ * lock than that held here), and finding this
+ * flag set may cause the execution of the code
+ * for updating parameters whose value may
+ * depend also on bfqg->entity.new_weight (in
+ * __bfq_entity_update_weight_prio).
+ * This barrier makes sure that the new value
+ * of bfqg->entity.new_weight is correctly
+ * seen in that code.
+ */
+ smp_wmb();
+ bfqg->entity.prio_changed = 1;
+ }
+ }
+ spin_unlock_irq(&blkcg->lock);
+
+ return ret;
+}
+
+static ssize_t bfq_io_set_weight(struct kernfs_open_file *of,
+ char *buf, size_t nbytes,
+ loff_t off)
+{
+ u64 weight;
+ /* First unsigned long found in the file is used */
+ int ret = kstrtoull(strim(buf), 0, &weight);
+
+ if (ret)
+ return ret;
+
+ ret = bfq_io_set_weight_legacy(of_css(of), NULL, weight);
+ return ret ?: nbytes;
+}
+
+static int bfqg_print_stat(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat,
+ &blkcg_policy_bfq, seq_cft(sf)->private, false);
+ return 0;
+}
+
+static int bfqg_print_rwstat(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat,
+ &blkcg_policy_bfq, seq_cft(sf)->private, true);
+ return 0;
+}
+
+static u64 bfqg_prfill_stat_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ u64 sum = blkg_stat_recursive_sum(pd_to_blkg(pd),
+ &blkcg_policy_bfq, off);
+ return __blkg_prfill_u64(sf, pd, sum);
+}
+
+static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct blkg_rwstat sum = blkg_rwstat_recursive_sum(pd_to_blkg(pd),
+ &blkcg_policy_bfq,
+ off);
+ return __blkg_prfill_rwstat(sf, pd, &sum);
+}
+
+static int bfqg_print_stat_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ bfqg_prfill_stat_recursive, &blkcg_policy_bfq,
+ seq_cft(sf)->private, false);
+ return 0;
+}
+
+static int bfqg_print_rwstat_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ bfqg_prfill_rwstat_recursive, &blkcg_policy_bfq,
+ seq_cft(sf)->private, true);
+ return 0;
+}
+
+static u64 bfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off)
+{
+ u64 sum = blkg_rwstat_total(&pd->blkg->stat_bytes);
+
+ return __blkg_prfill_u64(sf, pd, sum >> 9);
+}
+
+static int bfqg_print_stat_sectors(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ bfqg_prfill_sectors, &blkcg_policy_bfq, 0, false);
+ return 0;
+}
+
+static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct blkg_rwstat tmp = blkg_rwstat_recursive_sum(pd->blkg, NULL,
+ offsetof(struct blkcg_gq, stat_bytes));
+ u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +
+ atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]);
+
+ return __blkg_prfill_u64(sf, pd, sum >> 9);
+}
+
+static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ bfqg_prfill_sectors_recursive, &blkcg_policy_bfq, 0,
+ false);
+ return 0;
+}
+
+static u64 bfqg_prfill_avg_queue_size(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct bfq_group *bfqg = pd_to_bfqg(pd);
+ u64 samples = blkg_stat_read(&bfqg->stats.avg_queue_size_samples);
+ u64 v = 0;
+
+ if (samples) {
+ v = blkg_stat_read(&bfqg->stats.avg_queue_size_sum);
+ v = div64_u64(v, samples);
+ }
+ __blkg_prfill_u64(sf, pd, v);
+ return 0;
+}
+
+/* print avg_queue_size */
+static int bfqg_print_avg_queue_size(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ bfqg_prfill_avg_queue_size, &blkcg_policy_bfq,
+ 0, false);
+ return 0;
+}
+
+struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
+{
+ int ret;
+
+ ret = blkcg_activate_policy(bfqd->queue, &blkcg_policy_bfq);
+ if (ret)
+ return NULL;
+
+ return blkg_to_bfqg(bfqd->queue->root_blkg);
+}
+
+struct blkcg_policy blkcg_policy_bfq = {
+ .dfl_cftypes = bfq_blkg_files,
+ .legacy_cftypes = bfq_blkcg_legacy_files,
+
+ .cpd_alloc_fn = bfq_cpd_alloc,
+ .cpd_init_fn = bfq_cpd_init,
+ .cpd_bind_fn = bfq_cpd_init,
+ .cpd_free_fn = bfq_cpd_free,
+
+ .pd_alloc_fn = bfq_pd_alloc,
+ .pd_init_fn = bfq_pd_init,
+ .pd_offline_fn = bfq_pd_offline,
+ .pd_free_fn = bfq_pd_free,
+ .pd_reset_stats_fn = bfq_pd_reset_stats,
+};
+
+struct cftype bfq_blkcg_legacy_files[] = {
+ {
+ .name = "bfq.weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = bfq_io_show_weight,
+ .write_u64 = bfq_io_set_weight_legacy,
+ },
+
+ /* statistics, covers only the tasks in the bfqg */
+ {
+ .name = "bfq.time",
+ .private = offsetof(struct bfq_group, stats.time),
+ .seq_show = bfqg_print_stat,
+ },
+ {
+ .name = "bfq.sectors",
+ .seq_show = bfqg_print_stat_sectors,
+ },
+ {
+ .name = "bfq.io_service_bytes",
+ .private = (unsigned long)&blkcg_policy_bfq,
+ .seq_show = blkg_print_stat_bytes,
+ },
+ {
+ .name = "bfq.io_serviced",
+ .private = (unsigned long)&blkcg_policy_bfq,
+ .seq_show = blkg_print_stat_ios,
+ },
+ {
+ .name = "bfq.io_service_time",
+ .private = offsetof(struct bfq_group, stats.service_time),
+ .seq_show = bfqg_print_rwstat,
+ },
+ {
+ .name = "bfq.io_wait_time",
+ .private = offsetof(struct bfq_group, stats.wait_time),
+ .seq_show = bfqg_print_rwstat,
+ },
+ {
+ .name = "bfq.io_merged",
+ .private = offsetof(struct bfq_group, stats.merged),
+ .seq_show = bfqg_print_rwstat,
+ },
+ {
+ .name = "bfq.io_queued",
+ .private = offsetof(struct bfq_group, stats.queued),
+ .seq_show = bfqg_print_rwstat,
+ },
+
+ /* the same statictics which cover the bfqg and its descendants */
+ {
+ .name = "bfq.time_recursive",
+ .private = offsetof(struct bfq_group, stats.time),
+ .seq_show = bfqg_print_stat_recursive,
+ },
+ {
+ .name = "bfq.sectors_recursive",
+ .seq_show = bfqg_print_stat_sectors_recursive,
+ },
+ {
+ .name = "bfq.io_service_bytes_recursive",
+ .private = (unsigned long)&blkcg_policy_bfq,
+ .seq_show = blkg_print_stat_bytes_recursive,
+ },
+ {
+ .name = "bfq.io_serviced_recursive",
+ .private = (unsigned long)&blkcg_policy_bfq,
+ .seq_show = blkg_print_stat_ios_recursive,
+ },
+ {
+ .name = "bfq.io_service_time_recursive",
+ .private = offsetof(struct bfq_group, stats.service_time),
+ .seq_show = bfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "bfq.io_wait_time_recursive",
+ .private = offsetof(struct bfq_group, stats.wait_time),
+ .seq_show = bfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "bfq.io_merged_recursive",
+ .private = offsetof(struct bfq_group, stats.merged),
+ .seq_show = bfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "bfq.io_queued_recursive",
+ .private = offsetof(struct bfq_group, stats.queued),
+ .seq_show = bfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "bfq.avg_queue_size",
+ .seq_show = bfqg_print_avg_queue_size,
+ },
+ {
+ .name = "bfq.group_wait_time",
+ .private = offsetof(struct bfq_group, stats.group_wait_time),
+ .seq_show = bfqg_print_stat,
+ },
+ {
+ .name = "bfq.idle_time",
+ .private = offsetof(struct bfq_group, stats.idle_time),
+ .seq_show = bfqg_print_stat,
+ },
+ {
+ .name = "bfq.empty_time",
+ .private = offsetof(struct bfq_group, stats.empty_time),
+ .seq_show = bfqg_print_stat,
+ },
+ {
+ .name = "bfq.dequeue",
+ .private = offsetof(struct bfq_group, stats.dequeue),
+ .seq_show = bfqg_print_stat,
+ },
+ { } /* terminate */
+};
+
+struct cftype bfq_blkg_files[] = {
+ {
+ .name = "bfq.weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = bfq_io_show_weight,
+ .write = bfq_io_set_weight,
+ },
+ {} /* terminate */
+};
+
+#else /* CONFIG_BFQ_GROUP_IOSCHED */
+
+void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq,
+ unsigned int op) { }
+void bfqg_stats_update_io_remove(struct bfq_group *bfqg, unsigned int op) { }
+void bfqg_stats_update_io_merged(struct bfq_group *bfqg, unsigned int op) { }
+void bfqg_stats_update_completion(struct bfq_group *bfqg, uint64_t start_time,
+ uint64_t io_start_time, unsigned int op) { }
+void bfqg_stats_update_dequeue(struct bfq_group *bfqg) { }
+void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg) { }
+void bfqg_stats_update_idle_time(struct bfq_group *bfqg) { }
+void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg) { }
+void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg) { }
+
+void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ struct bfq_group *bfqg) {}
+
+void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+
+ entity->weight = entity->new_weight;
+ entity->orig_weight = entity->new_weight;
+ if (bfqq) {
+ bfqq->ioprio = bfqq->new_ioprio;
+ bfqq->ioprio_class = bfqq->new_ioprio_class;
+ }
+ entity->sched_data = &bfqg->sched_data;
+}
+
+void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) {}
+
+void bfq_end_wr_async(struct bfq_data *bfqd)
+{
+ bfq_end_wr_async_queues(bfqd, bfqd->root_group);
+}
+
+struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, struct blkcg *blkcg)
+{
+ return bfqd->root_group;
+}
+
+struct bfq_group *bfqq_group(struct bfq_queue *bfqq)
+{
+ return bfqq->bfqd->root_group;
+}
+
+struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
+{
+ struct bfq_group *bfqg;
+ int i;
+
+ bfqg = kmalloc_node(sizeof(*bfqg), GFP_KERNEL | __GFP_ZERO, node);
+ if (!bfqg)
+ return NULL;
+
+ for (i = 0; i < BFQ_IOPRIO_CLASSES; i++)
+ bfqg->sched_data.service_tree[i] = BFQ_SERVICE_TREE_INIT;
+
+ return bfqg;
+}
+#endif /* CONFIG_BFQ_GROUP_IOSCHED */
diff --git a/src/kernel/linux/v4.14/block/bfq-iosched.c b/src/kernel/linux/v4.14/block/bfq-iosched.c
new file mode 100644
index 0000000..959bee9
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/bfq-iosched.c
@@ -0,0 +1,5153 @@
+/*
+ * Budget Fair Queueing (BFQ) I/O scheduler.
+ *
+ * Based on ideas and code from CFQ:
+ * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
+ *
+ * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
+ * Paolo Valente <paolo.valente@unimore.it>
+ *
+ * Copyright (C) 2010 Paolo Valente <paolo.valente@unimore.it>
+ * Arianna Avanzini <avanzini@google.com>
+ *
+ * Copyright (C) 2017 Paolo Valente <paolo.valente@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * BFQ is a proportional-share I/O scheduler, with some extra
+ * low-latency capabilities. BFQ also supports full hierarchical
+ * scheduling through cgroups. Next paragraphs provide an introduction
+ * on BFQ inner workings. Details on BFQ benefits, usage and
+ * limitations can be found in Documentation/block/bfq-iosched.txt.
+ *
+ * BFQ is a proportional-share storage-I/O scheduling algorithm based
+ * on the slice-by-slice service scheme of CFQ. But BFQ assigns
+ * budgets, measured in number of sectors, to processes instead of
+ * time slices. The device is not granted to the in-service process
+ * for a given time slice, but until it has exhausted its assigned
+ * budget. This change from the time to the service domain enables BFQ
+ * to distribute the device throughput among processes as desired,
+ * without any distortion due to throughput fluctuations, or to device
+ * internal queueing. BFQ uses an ad hoc internal scheduler, called
+ * B-WF2Q+, to schedule processes according to their budgets. More
+ * precisely, BFQ schedules queues associated with processes. Each
+ * process/queue is assigned a user-configurable weight, and B-WF2Q+
+ * guarantees that each queue receives a fraction of the throughput
+ * proportional to its weight. Thanks to the accurate policy of
+ * B-WF2Q+, BFQ can afford to assign high budgets to I/O-bound
+ * processes issuing sequential requests (to boost the throughput),
+ * and yet guarantee a low latency to interactive and soft real-time
+ * applications.
+ *
+ * In particular, to provide these low-latency guarantees, BFQ
+ * explicitly privileges the I/O of two classes of time-sensitive
+ * applications: interactive and soft real-time. This feature enables
+ * BFQ to provide applications in these classes with a very low
+ * latency. Finally, BFQ also features additional heuristics for
+ * preserving both a low latency and a high throughput on NCQ-capable,
+ * rotational or flash-based devices, and to get the job done quickly
+ * for applications consisting in many I/O-bound processes.
+ *
+ * NOTE: if the main or only goal, with a given device, is to achieve
+ * the maximum-possible throughput at all times, then do switch off
+ * all low-latency heuristics for that device, by setting low_latency
+ * to 0.
+ *
+ * BFQ is described in [1], where also a reference to the initial, more
+ * theoretical paper on BFQ can be found. The interested reader can find
+ * in the latter paper full details on the main algorithm, as well as
+ * formulas of the guarantees and formal proofs of all the properties.
+ * With respect to the version of BFQ presented in these papers, this
+ * implementation adds a few more heuristics, such as the one that
+ * guarantees a low latency to soft real-time applications, and a
+ * hierarchical extension based on H-WF2Q+.
+ *
+ * B-WF2Q+ is based on WF2Q+, which is described in [2], together with
+ * H-WF2Q+, while the augmented tree used here to implement B-WF2Q+
+ * with O(log N) complexity derives from the one introduced with EEVDF
+ * in [3].
+ *
+ * [1] P. Valente, A. Avanzini, "Evolution of the BFQ Storage I/O
+ * Scheduler", Proceedings of the First Workshop on Mobile System
+ * Technologies (MST-2015), May 2015.
+ * http://algogroup.unimore.it/people/paolo/disk_sched/mst-2015.pdf
+ *
+ * [2] Jon C.R. Bennett and H. Zhang, "Hierarchical Packet Fair Queueing
+ * Algorithms", IEEE/ACM Transactions on Networking, 5(5):675-689,
+ * Oct 1997.
+ *
+ * http://www.cs.cmu.edu/~hzhang/papers/TON-97-Oct.ps.gz
+ *
+ * [3] I. Stoica and H. Abdel-Wahab, "Earliest Eligible Virtual Deadline
+ * First: A Flexible and Accurate Mechanism for Proportional Share
+ * Resource Allocation", technical report.
+ *
+ * http://www.cs.berkeley.edu/~istoica/papers/eevdf-tr-95.pdf
+ */
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/cgroup.h>
+#include <linux/elevator.h>
+#include <linux/ktime.h>
+#include <linux/rbtree.h>
+#include <linux/ioprio.h>
+#include <linux/sbitmap.h>
+#include <linux/delay.h>
+
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-tag.h"
+#include "blk-mq-sched.h"
+#include "bfq-iosched.h"
+#include "blk-wbt.h"
+
+#define BFQ_BFQQ_FNS(name) \
+void bfq_mark_bfqq_##name(struct bfq_queue *bfqq) \
+{ \
+ __set_bit(BFQQF_##name, &(bfqq)->flags); \
+} \
+void bfq_clear_bfqq_##name(struct bfq_queue *bfqq) \
+{ \
+ __clear_bit(BFQQF_##name, &(bfqq)->flags); \
+} \
+int bfq_bfqq_##name(const struct bfq_queue *bfqq) \
+{ \
+ return test_bit(BFQQF_##name, &(bfqq)->flags); \
+}
+
+BFQ_BFQQ_FNS(just_created);
+BFQ_BFQQ_FNS(busy);
+BFQ_BFQQ_FNS(wait_request);
+BFQ_BFQQ_FNS(non_blocking_wait_rq);
+BFQ_BFQQ_FNS(fifo_expire);
+BFQ_BFQQ_FNS(has_short_ttime);
+BFQ_BFQQ_FNS(sync);
+BFQ_BFQQ_FNS(IO_bound);
+BFQ_BFQQ_FNS(in_large_burst);
+BFQ_BFQQ_FNS(coop);
+BFQ_BFQQ_FNS(split_coop);
+BFQ_BFQQ_FNS(softrt_update);
+#undef BFQ_BFQQ_FNS \
+
+/* Expiration time of sync (0) and async (1) requests, in ns. */
+static const u64 bfq_fifo_expire[2] = { NSEC_PER_SEC / 4, NSEC_PER_SEC / 8 };
+
+/* Maximum backwards seek (magic number lifted from CFQ), in KiB. */
+static const int bfq_back_max = 16 * 1024;
+
+/* Penalty of a backwards seek, in number of sectors. */
+static const int bfq_back_penalty = 2;
+
+/* Idling period duration, in ns. */
+static u64 bfq_slice_idle = NSEC_PER_SEC / 125;
+
+/* Minimum number of assigned budgets for which stats are safe to compute. */
+static const int bfq_stats_min_budgets = 194;
+
+/* Default maximum budget values, in sectors and number of requests. */
+static const int bfq_default_max_budget = 16 * 1024;
+
+/*
+ * Async to sync throughput distribution is controlled as follows:
+ * when an async request is served, the entity is charged the number
+ * of sectors of the request, multiplied by the factor below
+ */
+static const int bfq_async_charge_factor = 10;
+
+/* Default timeout values, in jiffies, approximating CFQ defaults. */
+const int bfq_timeout = HZ / 8;
+
+static struct kmem_cache *bfq_pool;
+
+/* Below this threshold (in ns), we consider thinktime immediate. */
+#define BFQ_MIN_TT (2 * NSEC_PER_MSEC)
+
+/* hw_tag detection: parallel requests threshold and min samples needed. */
+#define BFQ_HW_QUEUE_THRESHOLD 4
+#define BFQ_HW_QUEUE_SAMPLES 32
+
+#define BFQQ_SEEK_THR (sector_t)(8 * 100)
+#define BFQQ_SECT_THR_NONROT (sector_t)(2 * 32)
+#define BFQQ_CLOSE_THR (sector_t)(8 * 1024)
+#define BFQQ_SEEKY(bfqq) (hweight32(bfqq->seek_history) > 32/8)
+
+/* Min number of samples required to perform peak-rate update */
+#define BFQ_RATE_MIN_SAMPLES 32
+/* Min observation time interval required to perform a peak-rate update (ns) */
+#define BFQ_RATE_MIN_INTERVAL (300*NSEC_PER_MSEC)
+/* Target observation time interval for a peak-rate update (ns) */
+#define BFQ_RATE_REF_INTERVAL NSEC_PER_SEC
+
+/* Shift used for peak rate fixed precision calculations. */
+#define BFQ_RATE_SHIFT 16
+
+/*
+ * By default, BFQ computes the duration of the weight raising for
+ * interactive applications automatically, using the following formula:
+ * duration = (R / r) * T, where r is the peak rate of the device, and
+ * R and T are two reference parameters.
+ * In particular, R is the peak rate of the reference device (see below),
+ * and T is a reference time: given the systems that are likely to be
+ * installed on the reference device according to its speed class, T is
+ * about the maximum time needed, under BFQ and while reading two files in
+ * parallel, to load typical large applications on these systems.
+ * In practice, the slower/faster the device at hand is, the more/less it
+ * takes to load applications with respect to the reference device.
+ * Accordingly, the longer/shorter BFQ grants weight raising to interactive
+ * applications.
+ *
+ * BFQ uses four different reference pairs (R, T), depending on:
+ * . whether the device is rotational or non-rotational;
+ * . whether the device is slow, such as old or portable HDDs, as well as
+ * SD cards, or fast, such as newer HDDs and SSDs.
+ *
+ * The device's speed class is dynamically (re)detected in
+ * bfq_update_peak_rate() every time the estimated peak rate is updated.
+ *
+ * In the following definitions, R_slow[0]/R_fast[0] and
+ * T_slow[0]/T_fast[0] are the reference values for a slow/fast
+ * rotational device, whereas R_slow[1]/R_fast[1] and
+ * T_slow[1]/T_fast[1] are the reference values for a slow/fast
+ * non-rotational device. Finally, device_speed_thresh are the
+ * thresholds used to switch between speed classes. The reference
+ * rates are not the actual peak rates of the devices used as a
+ * reference, but slightly lower values. The reason for using these
+ * slightly lower values is that the peak-rate estimator tends to
+ * yield slightly lower values than the actual peak rate (it can yield
+ * the actual peak rate only if there is only one process doing I/O,
+ * and the process does sequential I/O).
+ *
+ * Both the reference peak rates and the thresholds are measured in
+ * sectors/usec, left-shifted by BFQ_RATE_SHIFT.
+ */
+static int R_slow[2] = {1000, 10700};
+static int R_fast[2] = {14000, 33000};
+/*
+ * To improve readability, a conversion function is used to initialize the
+ * following arrays, which entails that they can be initialized only in a
+ * function.
+ */
+static int T_slow[2];
+static int T_fast[2];
+static int device_speed_thresh[2];
+
+#define RQ_BIC(rq) icq_to_bic((rq)->elv.priv[0])
+#define RQ_BFQQ(rq) ((rq)->elv.priv[1])
+
+struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, bool is_sync)
+{
+ return bic->bfqq[is_sync];
+}
+
+void bic_set_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq, bool is_sync)
+{
+ bic->bfqq[is_sync] = bfqq;
+}
+
+struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic)
+{
+ return bic->icq.q->elevator->elevator_data;
+}
+
+/**
+ * icq_to_bic - convert iocontext queue structure to bfq_io_cq.
+ * @icq: the iocontext queue.
+ */
+static struct bfq_io_cq *icq_to_bic(struct io_cq *icq)
+{
+ /* bic->icq is the first member, %NULL will convert to %NULL */
+ return container_of(icq, struct bfq_io_cq, icq);
+}
+
+/**
+ * bfq_bic_lookup - search into @ioc a bic associated to @bfqd.
+ * @bfqd: the lookup key.
+ * @ioc: the io_context of the process doing I/O.
+ * @q: the request queue.
+ */
+static struct bfq_io_cq *bfq_bic_lookup(struct bfq_data *bfqd,
+ struct io_context *ioc,
+ struct request_queue *q)
+{
+ if (ioc) {
+ unsigned long flags;
+ struct bfq_io_cq *icq;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ icq = icq_to_bic(ioc_lookup_icq(ioc, q));
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ return icq;
+ }
+
+ return NULL;
+}
+
+/*
+ * Scheduler run of queue, if there are requests pending and no one in the
+ * driver that will restart queueing.
+ */
+void bfq_schedule_dispatch(struct bfq_data *bfqd)
+{
+ if (bfqd->queued != 0) {
+ bfq_log(bfqd, "schedule dispatch");
+ blk_mq_run_hw_queues(bfqd->queue, true);
+ }
+}
+
+#define bfq_class_idle(bfqq) ((bfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
+#define bfq_class_rt(bfqq) ((bfqq)->ioprio_class == IOPRIO_CLASS_RT)
+
+#define bfq_sample_valid(samples) ((samples) > 80)
+
+/*
+ * Lifted from AS - choose which of rq1 and rq2 that is best served now.
+ * We choose the request that is closesr to the head right now. Distance
+ * behind the head is penalized and only allowed to a certain extent.
+ */
+static struct request *bfq_choose_req(struct bfq_data *bfqd,
+ struct request *rq1,
+ struct request *rq2,
+ sector_t last)
+{
+ sector_t s1, s2, d1 = 0, d2 = 0;
+ unsigned long back_max;
+#define BFQ_RQ1_WRAP 0x01 /* request 1 wraps */
+#define BFQ_RQ2_WRAP 0x02 /* request 2 wraps */
+ unsigned int wrap = 0; /* bit mask: requests behind the disk head? */
+
+ if (!rq1 || rq1 == rq2)
+ return rq2;
+ if (!rq2)
+ return rq1;
+
+ if (rq_is_sync(rq1) && !rq_is_sync(rq2))
+ return rq1;
+ else if (rq_is_sync(rq2) && !rq_is_sync(rq1))
+ return rq2;
+ if ((rq1->cmd_flags & REQ_META) && !(rq2->cmd_flags & REQ_META))
+ return rq1;
+ else if ((rq2->cmd_flags & REQ_META) && !(rq1->cmd_flags & REQ_META))
+ return rq2;
+
+ s1 = blk_rq_pos(rq1);
+ s2 = blk_rq_pos(rq2);
+
+ /*
+ * By definition, 1KiB is 2 sectors.
+ */
+ back_max = bfqd->bfq_back_max * 2;
+
+ /*
+ * Strict one way elevator _except_ in the case where we allow
+ * short backward seeks which are biased as twice the cost of a
+ * similar forward seek.
+ */
+ if (s1 >= last)
+ d1 = s1 - last;
+ else if (s1 + back_max >= last)
+ d1 = (last - s1) * bfqd->bfq_back_penalty;
+ else
+ wrap |= BFQ_RQ1_WRAP;
+
+ if (s2 >= last)
+ d2 = s2 - last;
+ else if (s2 + back_max >= last)
+ d2 = (last - s2) * bfqd->bfq_back_penalty;
+ else
+ wrap |= BFQ_RQ2_WRAP;
+
+ /* Found required data */
+
+ /*
+ * By doing switch() on the bit mask "wrap" we avoid having to
+ * check two variables for all permutations: --> faster!
+ */
+ switch (wrap) {
+ case 0: /* common case for CFQ: rq1 and rq2 not wrapped */
+ if (d1 < d2)
+ return rq1;
+ else if (d2 < d1)
+ return rq2;
+
+ if (s1 >= s2)
+ return rq1;
+ else
+ return rq2;
+
+ case BFQ_RQ2_WRAP:
+ return rq1;
+ case BFQ_RQ1_WRAP:
+ return rq2;
+ case BFQ_RQ1_WRAP|BFQ_RQ2_WRAP: /* both rqs wrapped */
+ default:
+ /*
+ * Since both rqs are wrapped,
+ * start with the one that's further behind head
+ * (--> only *one* back seek required),
+ * since back seek takes more time than forward.
+ */
+ if (s1 <= s2)
+ return rq1;
+ else
+ return rq2;
+ }
+}
+
+static struct bfq_queue *
+bfq_rq_pos_tree_lookup(struct bfq_data *bfqd, struct rb_root *root,
+ sector_t sector, struct rb_node **ret_parent,
+ struct rb_node ***rb_link)
+{
+ struct rb_node **p, *parent;
+ struct bfq_queue *bfqq = NULL;
+
+ parent = NULL;
+ p = &root->rb_node;
+ while (*p) {
+ struct rb_node **n;
+
+ parent = *p;
+ bfqq = rb_entry(parent, struct bfq_queue, pos_node);
+
+ /*
+ * Sort strictly based on sector. Smallest to the left,
+ * largest to the right.
+ */
+ if (sector > blk_rq_pos(bfqq->next_rq))
+ n = &(*p)->rb_right;
+ else if (sector < blk_rq_pos(bfqq->next_rq))
+ n = &(*p)->rb_left;
+ else
+ break;
+ p = n;
+ bfqq = NULL;
+ }
+
+ *ret_parent = parent;
+ if (rb_link)
+ *rb_link = p;
+
+ bfq_log(bfqd, "rq_pos_tree_lookup %llu: returning %d",
+ (unsigned long long)sector,
+ bfqq ? bfqq->pid : 0);
+
+ return bfqq;
+}
+
+void bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ struct rb_node **p, *parent;
+ struct bfq_queue *__bfqq;
+
+ if (bfqq->pos_root) {
+ rb_erase(&bfqq->pos_node, bfqq->pos_root);
+ bfqq->pos_root = NULL;
+ }
+
+ if (bfq_class_idle(bfqq))
+ return;
+ if (!bfqq->next_rq)
+ return;
+
+ bfqq->pos_root = &bfq_bfqq_to_bfqg(bfqq)->rq_pos_tree;
+ __bfqq = bfq_rq_pos_tree_lookup(bfqd, bfqq->pos_root,
+ blk_rq_pos(bfqq->next_rq), &parent, &p);
+ if (!__bfqq) {
+ rb_link_node(&bfqq->pos_node, parent, p);
+ rb_insert_color(&bfqq->pos_node, bfqq->pos_root);
+ } else
+ bfqq->pos_root = NULL;
+}
+
+/*
+ * Tell whether there are active queues or groups with differentiated weights.
+ */
+static bool bfq_differentiated_weights(struct bfq_data *bfqd)
+{
+ /*
+ * For weights to differ, at least one of the trees must contain
+ * at least two nodes.
+ */
+ return (!RB_EMPTY_ROOT(&bfqd->queue_weights_tree) &&
+ (bfqd->queue_weights_tree.rb_node->rb_left ||
+ bfqd->queue_weights_tree.rb_node->rb_right)
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ ) ||
+ (!RB_EMPTY_ROOT(&bfqd->group_weights_tree) &&
+ (bfqd->group_weights_tree.rb_node->rb_left ||
+ bfqd->group_weights_tree.rb_node->rb_right)
+#endif
+ );
+}
+
+/*
+ * The following function returns true if every queue must receive the
+ * same share of the throughput (this condition is used when deciding
+ * whether idling may be disabled, see the comments in the function
+ * bfq_bfqq_may_idle()).
+ *
+ * Such a scenario occurs when:
+ * 1) all active queues have the same weight,
+ * 2) all active groups at the same level in the groups tree have the same
+ * weight,
+ * 3) all active groups at the same level in the groups tree have the same
+ * number of children.
+ *
+ * Unfortunately, keeping the necessary state for evaluating exactly the
+ * above symmetry conditions would be quite complex and time-consuming.
+ * Therefore this function evaluates, instead, the following stronger
+ * sub-conditions, for which it is much easier to maintain the needed
+ * state:
+ * 1) all active queues have the same weight,
+ * 2) all active groups have the same weight,
+ * 3) all active groups have at most one active child each.
+ * In particular, the last two conditions are always true if hierarchical
+ * support and the cgroups interface are not enabled, thus no state needs
+ * to be maintained in this case.
+ */
+static bool bfq_symmetric_scenario(struct bfq_data *bfqd)
+{
+ return !bfq_differentiated_weights(bfqd);
+}
+
+/*
+ * If the weight-counter tree passed as input contains no counter for
+ * the weight of the input entity, then add that counter; otherwise just
+ * increment the existing counter.
+ *
+ * Note that weight-counter trees contain few nodes in mostly symmetric
+ * scenarios. For example, if all queues have the same weight, then the
+ * weight-counter tree for the queues may contain at most one node.
+ * This holds even if low_latency is on, because weight-raised queues
+ * are not inserted in the tree.
+ * In most scenarios, the rate at which nodes are created/destroyed
+ * should be low too.
+ */
+void bfq_weights_tree_add(struct bfq_data *bfqd, struct bfq_entity *entity,
+ struct rb_root *root)
+{
+ struct rb_node **new = &(root->rb_node), *parent = NULL;
+
+ /*
+ * Do not insert if the entity is already associated with a
+ * counter, which happens if:
+ * 1) the entity is associated with a queue,
+ * 2) a request arrival has caused the queue to become both
+ * non-weight-raised, and hence change its weight, and
+ * backlogged; in this respect, each of the two events
+ * causes an invocation of this function,
+ * 3) this is the invocation of this function caused by the
+ * second event. This second invocation is actually useless,
+ * and we handle this fact by exiting immediately. More
+ * efficient or clearer solutions might possibly be adopted.
+ */
+ if (entity->weight_counter)
+ return;
+
+ while (*new) {
+ struct bfq_weight_counter *__counter = container_of(*new,
+ struct bfq_weight_counter,
+ weights_node);
+ parent = *new;
+
+ if (entity->weight == __counter->weight) {
+ entity->weight_counter = __counter;
+ goto inc_counter;
+ }
+ if (entity->weight < __counter->weight)
+ new = &((*new)->rb_left);
+ else
+ new = &((*new)->rb_right);
+ }
+
+ entity->weight_counter = kzalloc(sizeof(struct bfq_weight_counter),
+ GFP_ATOMIC);
+
+ /*
+ * In the unlucky event of an allocation failure, we just
+ * exit. This will cause the weight of entity to not be
+ * considered in bfq_differentiated_weights, which, in its
+ * turn, causes the scenario to be deemed wrongly symmetric in
+ * case entity's weight would have been the only weight making
+ * the scenario asymmetric. On the bright side, no unbalance
+ * will however occur when entity becomes inactive again (the
+ * invocation of this function is triggered by an activation
+ * of entity). In fact, bfq_weights_tree_remove does nothing
+ * if !entity->weight_counter.
+ */
+ if (unlikely(!entity->weight_counter))
+ return;
+
+ entity->weight_counter->weight = entity->weight;
+ rb_link_node(&entity->weight_counter->weights_node, parent, new);
+ rb_insert_color(&entity->weight_counter->weights_node, root);
+
+inc_counter:
+ entity->weight_counter->num_active++;
+}
+
+/*
+ * Decrement the weight counter associated with the entity, and, if the
+ * counter reaches 0, remove the counter from the tree.
+ * See the comments to the function bfq_weights_tree_add() for considerations
+ * about overhead.
+ */
+void bfq_weights_tree_remove(struct bfq_data *bfqd, struct bfq_entity *entity,
+ struct rb_root *root)
+{
+ if (!entity->weight_counter)
+ return;
+
+ entity->weight_counter->num_active--;
+ if (entity->weight_counter->num_active > 0)
+ goto reset_entity_pointer;
+
+ rb_erase(&entity->weight_counter->weights_node, root);
+ kfree(entity->weight_counter);
+
+reset_entity_pointer:
+ entity->weight_counter = NULL;
+}
+
+/*
+ * Return expired entry, or NULL to just start from scratch in rbtree.
+ */
+static struct request *bfq_check_fifo(struct bfq_queue *bfqq,
+ struct request *last)
+{
+ struct request *rq;
+
+ if (bfq_bfqq_fifo_expire(bfqq))
+ return NULL;
+
+ bfq_mark_bfqq_fifo_expire(bfqq);
+
+ rq = rq_entry_fifo(bfqq->fifo.next);
+
+ if (rq == last || ktime_get_ns() < rq->fifo_time)
+ return NULL;
+
+ bfq_log_bfqq(bfqq->bfqd, bfqq, "check_fifo: returned %p", rq);
+ return rq;
+}
+
+static struct request *bfq_find_next_rq(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq,
+ struct request *last)
+{
+ struct rb_node *rbnext = rb_next(&last->rb_node);
+ struct rb_node *rbprev = rb_prev(&last->rb_node);
+ struct request *next, *prev = NULL;
+
+ /* Follow expired path, else get first next available. */
+ next = bfq_check_fifo(bfqq, last);
+ if (next)
+ return next;
+
+ if (rbprev)
+ prev = rb_entry_rq(rbprev);
+
+ if (rbnext)
+ next = rb_entry_rq(rbnext);
+ else {
+ rbnext = rb_first(&bfqq->sort_list);
+ if (rbnext && rbnext != &last->rb_node)
+ next = rb_entry_rq(rbnext);
+ }
+
+ return bfq_choose_req(bfqd, next, prev, blk_rq_pos(last));
+}
+
+/* see the definition of bfq_async_charge_factor for details */
+static unsigned long bfq_serv_to_charge(struct request *rq,
+ struct bfq_queue *bfqq)
+{
+ if (bfq_bfqq_sync(bfqq) || bfqq->wr_coeff > 1)
+ return blk_rq_sectors(rq);
+
+ /*
+ * If there are no weight-raised queues, then amplify service
+ * by just the async charge factor; otherwise amplify service
+ * by twice the async charge factor, to further reduce latency
+ * for weight-raised queues.
+ */
+ if (bfqq->bfqd->wr_busy_queues == 0)
+ return blk_rq_sectors(rq) * bfq_async_charge_factor;
+
+ return blk_rq_sectors(rq) * 2 * bfq_async_charge_factor;
+}
+
+/**
+ * bfq_updated_next_req - update the queue after a new next_rq selection.
+ * @bfqd: the device data the queue belongs to.
+ * @bfqq: the queue to update.
+ *
+ * If the first request of a queue changes we make sure that the queue
+ * has enough budget to serve at least its first request (if the
+ * request has grown). We do this because if the queue has not enough
+ * budget for its first request, it has to go through two dispatch
+ * rounds to actually get it dispatched.
+ */
+static void bfq_updated_next_req(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+ struct request *next_rq = bfqq->next_rq;
+ unsigned long new_budget;
+
+ if (!next_rq)
+ return;
+
+ if (bfqq == bfqd->in_service_queue)
+ /*
+ * In order not to break guarantees, budgets cannot be
+ * changed after an entity has been selected.
+ */
+ return;
+
+ new_budget = max_t(unsigned long, bfqq->max_budget,
+ bfq_serv_to_charge(next_rq, bfqq));
+ if (entity->budget != new_budget) {
+ entity->budget = new_budget;
+ bfq_log_bfqq(bfqd, bfqq, "updated next rq: new budget %lu",
+ new_budget);
+ bfq_requeue_bfqq(bfqd, bfqq, false);
+ }
+}
+
+static void
+bfq_bfqq_resume_state(struct bfq_queue *bfqq, struct bfq_data *bfqd,
+ struct bfq_io_cq *bic, bool bfq_already_existing)
+{
+ unsigned int old_wr_coeff = bfqq->wr_coeff;
+ bool busy = bfq_already_existing && bfq_bfqq_busy(bfqq);
+
+ if (bic->saved_has_short_ttime)
+ bfq_mark_bfqq_has_short_ttime(bfqq);
+ else
+ bfq_clear_bfqq_has_short_ttime(bfqq);
+
+ if (bic->saved_IO_bound)
+ bfq_mark_bfqq_IO_bound(bfqq);
+ else
+ bfq_clear_bfqq_IO_bound(bfqq);
+
+ bfqq->ttime = bic->saved_ttime;
+ bfqq->wr_coeff = bic->saved_wr_coeff;
+ bfqq->wr_start_at_switch_to_srt = bic->saved_wr_start_at_switch_to_srt;
+ bfqq->last_wr_start_finish = bic->saved_last_wr_start_finish;
+ bfqq->wr_cur_max_time = bic->saved_wr_cur_max_time;
+
+ if (bfqq->wr_coeff > 1 && (bfq_bfqq_in_large_burst(bfqq) ||
+ time_is_before_jiffies(bfqq->last_wr_start_finish +
+ bfqq->wr_cur_max_time))) {
+ bfq_log_bfqq(bfqq->bfqd, bfqq,
+ "resume state: switching off wr");
+
+ bfqq->wr_coeff = 1;
+ }
+
+ /* make sure weight will be updated, however we got here */
+ bfqq->entity.prio_changed = 1;
+
+ if (likely(!busy))
+ return;
+
+ if (old_wr_coeff == 1 && bfqq->wr_coeff > 1)
+ bfqd->wr_busy_queues++;
+ else if (old_wr_coeff > 1 && bfqq->wr_coeff == 1)
+ bfqd->wr_busy_queues--;
+}
+
+static int bfqq_process_refs(struct bfq_queue *bfqq)
+{
+ return bfqq->ref - bfqq->allocated - bfqq->entity.on_st;
+}
+
+/* Empty burst list and add just bfqq (see comments on bfq_handle_burst) */
+static void bfq_reset_burst_list(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ struct bfq_queue *item;
+ struct hlist_node *n;
+
+ hlist_for_each_entry_safe(item, n, &bfqd->burst_list, burst_list_node)
+ hlist_del_init(&item->burst_list_node);
+ hlist_add_head(&bfqq->burst_list_node, &bfqd->burst_list);
+ bfqd->burst_size = 1;
+ bfqd->burst_parent_entity = bfqq->entity.parent;
+}
+
+/* Add bfqq to the list of queues in current burst (see bfq_handle_burst) */
+static void bfq_add_to_burst(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ /* Increment burst size to take into account also bfqq */
+ bfqd->burst_size++;
+
+ if (bfqd->burst_size == bfqd->bfq_large_burst_thresh) {
+ struct bfq_queue *pos, *bfqq_item;
+ struct hlist_node *n;
+
+ /*
+ * Enough queues have been activated shortly after each
+ * other to consider this burst as large.
+ */
+ bfqd->large_burst = true;
+
+ /*
+ * We can now mark all queues in the burst list as
+ * belonging to a large burst.
+ */
+ hlist_for_each_entry(bfqq_item, &bfqd->burst_list,
+ burst_list_node)
+ bfq_mark_bfqq_in_large_burst(bfqq_item);
+ bfq_mark_bfqq_in_large_burst(bfqq);
+
+ /*
+ * From now on, and until the current burst finishes, any
+ * new queue being activated shortly after the last queue
+ * was inserted in the burst can be immediately marked as
+ * belonging to a large burst. So the burst list is not
+ * needed any more. Remove it.
+ */
+ hlist_for_each_entry_safe(pos, n, &bfqd->burst_list,
+ burst_list_node)
+ hlist_del_init(&pos->burst_list_node);
+ } else /*
+ * Burst not yet large: add bfqq to the burst list. Do
+ * not increment the ref counter for bfqq, because bfqq
+ * is removed from the burst list before freeing bfqq
+ * in put_queue.
+ */
+ hlist_add_head(&bfqq->burst_list_node, &bfqd->burst_list);
+}
+
+/*
+ * If many queues belonging to the same group happen to be created
+ * shortly after each other, then the processes associated with these
+ * queues have typically a common goal. In particular, bursts of queue
+ * creations are usually caused by services or applications that spawn
+ * many parallel threads/processes. Examples are systemd during boot,
+ * or git grep. To help these processes get their job done as soon as
+ * possible, it is usually better to not grant either weight-raising
+ * or device idling to their queues.
+ *
+ * In this comment we describe, firstly, the reasons why this fact
+ * holds, and, secondly, the next function, which implements the main
+ * steps needed to properly mark these queues so that they can then be
+ * treated in a different way.
+ *
+ * The above services or applications benefit mostly from a high
+ * throughput: the quicker the requests of the activated queues are
+ * cumulatively served, the sooner the target job of these queues gets
+ * completed. As a consequence, weight-raising any of these queues,
+ * which also implies idling the device for it, is almost always
+ * counterproductive. In most cases it just lowers throughput.
+ *
+ * On the other hand, a burst of queue creations may be caused also by
+ * the start of an application that does not consist of a lot of
+ * parallel I/O-bound threads. In fact, with a complex application,
+ * several short processes may need to be executed to start-up the
+ * application. In this respect, to start an application as quickly as
+ * possible, the best thing to do is in any case to privilege the I/O
+ * related to the application with respect to all other
+ * I/O. Therefore, the best strategy to start as quickly as possible
+ * an application that causes a burst of queue creations is to
+ * weight-raise all the queues created during the burst. This is the
+ * exact opposite of the best strategy for the other type of bursts.
+ *
+ * In the end, to take the best action for each of the two cases, the
+ * two types of bursts need to be distinguished. Fortunately, this
+ * seems relatively easy, by looking at the sizes of the bursts. In
+ * particular, we found a threshold such that only bursts with a
+ * larger size than that threshold are apparently caused by
+ * services or commands such as systemd or git grep. For brevity,
+ * hereafter we call just 'large' these bursts. BFQ *does not*
+ * weight-raise queues whose creation occurs in a large burst. In
+ * addition, for each of these queues BFQ performs or does not perform
+ * idling depending on which choice boosts the throughput more. The
+ * exact choice depends on the device and request pattern at
+ * hand.
+ *
+ * Unfortunately, false positives may occur while an interactive task
+ * is starting (e.g., an application is being started). The
+ * consequence is that the queues associated with the task do not
+ * enjoy weight raising as expected. Fortunately these false positives
+ * are very rare. They typically occur if some service happens to
+ * start doing I/O exactly when the interactive task starts.
+ *
+ * Turning back to the next function, it implements all the steps
+ * needed to detect the occurrence of a large burst and to properly
+ * mark all the queues belonging to it (so that they can then be
+ * treated in a different way). This goal is achieved by maintaining a
+ * "burst list" that holds, temporarily, the queues that belong to the
+ * burst in progress. The list is then used to mark these queues as
+ * belonging to a large burst if the burst does become large. The main
+ * steps are the following.
+ *
+ * . when the very first queue is created, the queue is inserted into the
+ * list (as it could be the first queue in a possible burst)
+ *
+ * . if the current burst has not yet become large, and a queue Q that does
+ * not yet belong to the burst is activated shortly after the last time
+ * at which a new queue entered the burst list, then the function appends
+ * Q to the burst list
+ *
+ * . if, as a consequence of the previous step, the burst size reaches
+ * the large-burst threshold, then
+ *
+ * . all the queues in the burst list are marked as belonging to a
+ * large burst
+ *
+ * . the burst list is deleted; in fact, the burst list already served
+ * its purpose (keeping temporarily track of the queues in a burst,
+ * so as to be able to mark them as belonging to a large burst in the
+ * previous sub-step), and now is not needed any more
+ *
+ * . the device enters a large-burst mode
+ *
+ * . if a queue Q that does not belong to the burst is created while
+ * the device is in large-burst mode and shortly after the last time
+ * at which a queue either entered the burst list or was marked as
+ * belonging to the current large burst, then Q is immediately marked
+ * as belonging to a large burst.
+ *
+ * . if a queue Q that does not belong to the burst is created a while
+ * later, i.e., not shortly after, than the last time at which a queue
+ * either entered the burst list or was marked as belonging to the
+ * current large burst, then the current burst is deemed as finished and:
+ *
+ * . the large-burst mode is reset if set
+ *
+ * . the burst list is emptied
+ *
+ * . Q is inserted in the burst list, as Q may be the first queue
+ * in a possible new burst (then the burst list contains just Q
+ * after this step).
+ */
+static void bfq_handle_burst(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ /*
+ * If bfqq is already in the burst list or is part of a large
+ * burst, or finally has just been split, then there is
+ * nothing else to do.
+ */
+ if (!hlist_unhashed(&bfqq->burst_list_node) ||
+ bfq_bfqq_in_large_burst(bfqq) ||
+ time_is_after_eq_jiffies(bfqq->split_time +
+ msecs_to_jiffies(10)))
+ return;
+
+ /*
+ * If bfqq's creation happens late enough, or bfqq belongs to
+ * a different group than the burst group, then the current
+ * burst is finished, and related data structures must be
+ * reset.
+ *
+ * In this respect, consider the special case where bfqq is
+ * the very first queue created after BFQ is selected for this
+ * device. In this case, last_ins_in_burst and
+ * burst_parent_entity are not yet significant when we get
+ * here. But it is easy to verify that, whether or not the
+ * following condition is true, bfqq will end up being
+ * inserted into the burst list. In particular the list will
+ * happen to contain only bfqq. And this is exactly what has
+ * to happen, as bfqq may be the first queue of the first
+ * burst.
+ */
+ if (time_is_before_jiffies(bfqd->last_ins_in_burst +
+ bfqd->bfq_burst_interval) ||
+ bfqq->entity.parent != bfqd->burst_parent_entity) {
+ bfqd->large_burst = false;
+ bfq_reset_burst_list(bfqd, bfqq);
+ goto end;
+ }
+
+ /*
+ * If we get here, then bfqq is being activated shortly after the
+ * last queue. So, if the current burst is also large, we can mark
+ * bfqq as belonging to this large burst immediately.
+ */
+ if (bfqd->large_burst) {
+ bfq_mark_bfqq_in_large_burst(bfqq);
+ goto end;
+ }
+
+ /*
+ * If we get here, then a large-burst state has not yet been
+ * reached, but bfqq is being activated shortly after the last
+ * queue. Then we add bfqq to the burst.
+ */
+ bfq_add_to_burst(bfqd, bfqq);
+end:
+ /*
+ * At this point, bfqq either has been added to the current
+ * burst or has caused the current burst to terminate and a
+ * possible new burst to start. In particular, in the second
+ * case, bfqq has become the first queue in the possible new
+ * burst. In both cases last_ins_in_burst needs to be moved
+ * forward.
+ */
+ bfqd->last_ins_in_burst = jiffies;
+}
+
+static int bfq_bfqq_budget_left(struct bfq_queue *bfqq)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+
+ return entity->budget - entity->service;
+}
+
+/*
+ * If enough samples have been computed, return the current max budget
+ * stored in bfqd, which is dynamically updated according to the
+ * estimated disk peak rate; otherwise return the default max budget
+ */
+static int bfq_max_budget(struct bfq_data *bfqd)
+{
+ if (bfqd->budgets_assigned < bfq_stats_min_budgets)
+ return bfq_default_max_budget;
+ else
+ return bfqd->bfq_max_budget;
+}
+
+/*
+ * Return min budget, which is a fraction of the current or default
+ * max budget (trying with 1/32)
+ */
+static int bfq_min_budget(struct bfq_data *bfqd)
+{
+ if (bfqd->budgets_assigned < bfq_stats_min_budgets)
+ return bfq_default_max_budget / 32;
+ else
+ return bfqd->bfq_max_budget / 32;
+}
+
+/*
+ * The next function, invoked after the input queue bfqq switches from
+ * idle to busy, updates the budget of bfqq. The function also tells
+ * whether the in-service queue should be expired, by returning
+ * true. The purpose of expiring the in-service queue is to give bfqq
+ * the chance to possibly preempt the in-service queue, and the reason
+ * for preempting the in-service queue is to achieve one of the two
+ * goals below.
+ *
+ * 1. Guarantee to bfqq its reserved bandwidth even if bfqq has
+ * expired because it has remained idle. In particular, bfqq may have
+ * expired for one of the following two reasons:
+ *
+ * - BFQQE_NO_MORE_REQUESTS bfqq did not enjoy any device idling
+ * and did not make it to issue a new request before its last
+ * request was served;
+ *
+ * - BFQQE_TOO_IDLE bfqq did enjoy device idling, but did not issue
+ * a new request before the expiration of the idling-time.
+ *
+ * Even if bfqq has expired for one of the above reasons, the process
+ * associated with the queue may be however issuing requests greedily,
+ * and thus be sensitive to the bandwidth it receives (bfqq may have
+ * remained idle for other reasons: CPU high load, bfqq not enjoying
+ * idling, I/O throttling somewhere in the path from the process to
+ * the I/O scheduler, ...). But if, after every expiration for one of
+ * the above two reasons, bfqq has to wait for the service of at least
+ * one full budget of another queue before being served again, then
+ * bfqq is likely to get a much lower bandwidth or resource time than
+ * its reserved ones. To address this issue, two countermeasures need
+ * to be taken.
+ *
+ * First, the budget and the timestamps of bfqq need to be updated in
+ * a special way on bfqq reactivation: they need to be updated as if
+ * bfqq did not remain idle and did not expire. In fact, if they are
+ * computed as if bfqq expired and remained idle until reactivation,
+ * then the process associated with bfqq is treated as if, instead of
+ * being greedy, it stopped issuing requests when bfqq remained idle,
+ * and restarts issuing requests only on this reactivation. In other
+ * words, the scheduler does not help the process recover the "service
+ * hole" between bfqq expiration and reactivation. As a consequence,
+ * the process receives a lower bandwidth than its reserved one. In
+ * contrast, to recover this hole, the budget must be updated as if
+ * bfqq was not expired at all before this reactivation, i.e., it must
+ * be set to the value of the remaining budget when bfqq was
+ * expired. Along the same line, timestamps need to be assigned the
+ * value they had the last time bfqq was selected for service, i.e.,
+ * before last expiration. Thus timestamps need to be back-shifted
+ * with respect to their normal computation (see [1] for more details
+ * on this tricky aspect).
+ *
+ * Secondly, to allow the process to recover the hole, the in-service
+ * queue must be expired too, to give bfqq the chance to preempt it
+ * immediately. In fact, if bfqq has to wait for a full budget of the
+ * in-service queue to be completed, then it may become impossible to
+ * let the process recover the hole, even if the back-shifted
+ * timestamps of bfqq are lower than those of the in-service queue. If
+ * this happens for most or all of the holes, then the process may not
+ * receive its reserved bandwidth. In this respect, it is worth noting
+ * that, being the service of outstanding requests unpreemptible, a
+ * little fraction of the holes may however be unrecoverable, thereby
+ * causing a little loss of bandwidth.
+ *
+ * The last important point is detecting whether bfqq does need this
+ * bandwidth recovery. In this respect, the next function deems the
+ * process associated with bfqq greedy, and thus allows it to recover
+ * the hole, if: 1) the process is waiting for the arrival of a new
+ * request (which implies that bfqq expired for one of the above two
+ * reasons), and 2) such a request has arrived soon. The first
+ * condition is controlled through the flag non_blocking_wait_rq,
+ * while the second through the flag arrived_in_time. If both
+ * conditions hold, then the function computes the budget in the
+ * above-described special way, and signals that the in-service queue
+ * should be expired. Timestamp back-shifting is done later in
+ * __bfq_activate_entity.
+ *
+ * 2. Reduce latency. Even if timestamps are not backshifted to let
+ * the process associated with bfqq recover a service hole, bfqq may
+ * however happen to have, after being (re)activated, a lower finish
+ * timestamp than the in-service queue. That is, the next budget of
+ * bfqq may have to be completed before the one of the in-service
+ * queue. If this is the case, then preempting the in-service queue
+ * allows this goal to be achieved, apart from the unpreemptible,
+ * outstanding requests mentioned above.
+ *
+ * Unfortunately, regardless of which of the above two goals one wants
+ * to achieve, service trees need first to be updated to know whether
+ * the in-service queue must be preempted. To have service trees
+ * correctly updated, the in-service queue must be expired and
+ * rescheduled, and bfqq must be scheduled too. This is one of the
+ * most costly operations (in future versions, the scheduling
+ * mechanism may be re-designed in such a way to make it possible to
+ * know whether preemption is needed without needing to update service
+ * trees). In addition, queue preemptions almost always cause random
+ * I/O, and thus loss of throughput. Because of these facts, the next
+ * function adopts the following simple scheme to avoid both costly
+ * operations and too frequent preemptions: it requests the expiration
+ * of the in-service queue (unconditionally) only for queues that need
+ * to recover a hole, or that either are weight-raised or deserve to
+ * be weight-raised.
+ */
+static bool bfq_bfqq_update_budg_for_activation(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq,
+ bool arrived_in_time,
+ bool wr_or_deserves_wr)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+
+ if (bfq_bfqq_non_blocking_wait_rq(bfqq) && arrived_in_time) {
+ /*
+ * We do not clear the flag non_blocking_wait_rq here, as
+ * the latter is used in bfq_activate_bfqq to signal
+ * that timestamps need to be back-shifted (and is
+ * cleared right after).
+ */
+
+ /*
+ * In next assignment we rely on that either
+ * entity->service or entity->budget are not updated
+ * on expiration if bfqq is empty (see
+ * __bfq_bfqq_recalc_budget). Thus both quantities
+ * remain unchanged after such an expiration, and the
+ * following statement therefore assigns to
+ * entity->budget the remaining budget on such an
+ * expiration. For clarity, entity->service is not
+ * updated on expiration in any case, and, in normal
+ * operation, is reset only when bfqq is selected for
+ * service (see bfq_get_next_queue).
+ */
+ entity->budget = min_t(unsigned long,
+ bfq_bfqq_budget_left(bfqq),
+ bfqq->max_budget);
+
+ return true;
+ }
+
+ entity->budget = max_t(unsigned long, bfqq->max_budget,
+ bfq_serv_to_charge(bfqq->next_rq, bfqq));
+ bfq_clear_bfqq_non_blocking_wait_rq(bfqq);
+ return wr_or_deserves_wr;
+}
+
+static unsigned int bfq_wr_duration(struct bfq_data *bfqd)
+{
+ u64 dur;
+
+ if (bfqd->bfq_wr_max_time > 0)
+ return bfqd->bfq_wr_max_time;
+
+ dur = bfqd->RT_prod;
+ do_div(dur, bfqd->peak_rate);
+
+ /*
+ * Limit duration between 3 and 13 seconds. Tests show that
+ * higher values than 13 seconds often yield the opposite of
+ * the desired result, i.e., worsen responsiveness by letting
+ * non-interactive and non-soft-real-time applications
+ * preserve weight raising for a too long time interval.
+ *
+ * On the other end, lower values than 3 seconds make it
+ * difficult for most interactive tasks to complete their jobs
+ * before weight-raising finishes.
+ */
+ if (dur > msecs_to_jiffies(13000))
+ dur = msecs_to_jiffies(13000);
+ else if (dur < msecs_to_jiffies(3000))
+ dur = msecs_to_jiffies(3000);
+
+ return dur;
+}
+
+/*
+ * Return the farthest future time instant according to jiffies
+ * macros.
+ */
+static unsigned long bfq_greatest_from_now(void)
+{
+ return jiffies + MAX_JIFFY_OFFSET;
+}
+
+/*
+ * Return the farthest past time instant according to jiffies
+ * macros.
+ */
+static unsigned long bfq_smallest_from_now(void)
+{
+ return jiffies - MAX_JIFFY_OFFSET;
+}
+
+static void bfq_update_bfqq_wr_on_rq_arrival(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq,
+ unsigned int old_wr_coeff,
+ bool wr_or_deserves_wr,
+ bool interactive,
+ bool in_burst,
+ bool soft_rt)
+{
+ if (old_wr_coeff == 1 && wr_or_deserves_wr) {
+ /* start a weight-raising period */
+ if (interactive) {
+ bfqq->wr_coeff = bfqd->bfq_wr_coeff;
+ bfqq->wr_cur_max_time = bfq_wr_duration(bfqd);
+ } else {
+ /*
+ * No interactive weight raising in progress
+ * here: assign minus infinity to
+ * wr_start_at_switch_to_srt, to make sure
+ * that, at the end of the soft-real-time
+ * weight raising periods that is starting
+ * now, no interactive weight-raising period
+ * may be wrongly considered as still in
+ * progress (and thus actually started by
+ * mistake).
+ */
+ bfqq->wr_start_at_switch_to_srt =
+ bfq_smallest_from_now();
+ bfqq->wr_coeff = bfqd->bfq_wr_coeff *
+ BFQ_SOFTRT_WEIGHT_FACTOR;
+ bfqq->wr_cur_max_time =
+ bfqd->bfq_wr_rt_max_time;
+ }
+
+ /*
+ * If needed, further reduce budget to make sure it is
+ * close to bfqq's backlog, so as to reduce the
+ * scheduling-error component due to a too large
+ * budget. Do not care about throughput consequences,
+ * but only about latency. Finally, do not assign a
+ * too small budget either, to avoid increasing
+ * latency by causing too frequent expirations.
+ */
+ bfqq->entity.budget = min_t(unsigned long,
+ bfqq->entity.budget,
+ 2 * bfq_min_budget(bfqd));
+ } else if (old_wr_coeff > 1) {
+ if (interactive) { /* update wr coeff and duration */
+ bfqq->wr_coeff = bfqd->bfq_wr_coeff;
+ bfqq->wr_cur_max_time = bfq_wr_duration(bfqd);
+ } else if (in_burst)
+ bfqq->wr_coeff = 1;
+ else if (soft_rt) {
+ /*
+ * The application is now or still meeting the
+ * requirements for being deemed soft rt. We
+ * can then correctly and safely (re)charge
+ * the weight-raising duration for the
+ * application with the weight-raising
+ * duration for soft rt applications.
+ *
+ * In particular, doing this recharge now, i.e.,
+ * before the weight-raising period for the
+ * application finishes, reduces the probability
+ * of the following negative scenario:
+ * 1) the weight of a soft rt application is
+ * raised at startup (as for any newly
+ * created application),
+ * 2) since the application is not interactive,
+ * at a certain time weight-raising is
+ * stopped for the application,
+ * 3) at that time the application happens to
+ * still have pending requests, and hence
+ * is destined to not have a chance to be
+ * deemed soft rt before these requests are
+ * completed (see the comments to the
+ * function bfq_bfqq_softrt_next_start()
+ * for details on soft rt detection),
+ * 4) these pending requests experience a high
+ * latency because the application is not
+ * weight-raised while they are pending.
+ */
+ if (bfqq->wr_cur_max_time !=
+ bfqd->bfq_wr_rt_max_time) {
+ bfqq->wr_start_at_switch_to_srt =
+ bfqq->last_wr_start_finish;
+
+ bfqq->wr_cur_max_time =
+ bfqd->bfq_wr_rt_max_time;
+ bfqq->wr_coeff = bfqd->bfq_wr_coeff *
+ BFQ_SOFTRT_WEIGHT_FACTOR;
+ }
+ bfqq->last_wr_start_finish = jiffies;
+ }
+ }
+}
+
+static bool bfq_bfqq_idle_for_long_time(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq)
+{
+ return bfqq->dispatched == 0 &&
+ time_is_before_jiffies(
+ bfqq->budget_timeout +
+ bfqd->bfq_wr_min_idle_time);
+}
+
+static void bfq_bfqq_handle_idle_busy_switch(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq,
+ int old_wr_coeff,
+ struct request *rq,
+ bool *interactive)
+{
+ bool soft_rt, in_burst, wr_or_deserves_wr,
+ bfqq_wants_to_preempt,
+ idle_for_long_time = bfq_bfqq_idle_for_long_time(bfqd, bfqq),
+ /*
+ * See the comments on
+ * bfq_bfqq_update_budg_for_activation for
+ * details on the usage of the next variable.
+ */
+ arrived_in_time = ktime_get_ns() <=
+ bfqq->ttime.last_end_request +
+ bfqd->bfq_slice_idle * 3;
+
+ bfqg_stats_update_io_add(bfqq_group(RQ_BFQQ(rq)), bfqq, rq->cmd_flags);
+
+ /*
+ * bfqq deserves to be weight-raised if:
+ * - it is sync,
+ * - it does not belong to a large burst,
+ * - it has been idle for enough time or is soft real-time,
+ * - is linked to a bfq_io_cq (it is not shared in any sense).
+ */
+ in_burst = bfq_bfqq_in_large_burst(bfqq);
+ soft_rt = bfqd->bfq_wr_max_softrt_rate > 0 &&
+ !in_burst &&
+ time_is_before_jiffies(bfqq->soft_rt_next_start);
+ *interactive = !in_burst && idle_for_long_time;
+ wr_or_deserves_wr = bfqd->low_latency &&
+ (bfqq->wr_coeff > 1 ||
+ (bfq_bfqq_sync(bfqq) &&
+ bfqq->bic && (*interactive || soft_rt)));
+
+ /*
+ * Using the last flag, update budget and check whether bfqq
+ * may want to preempt the in-service queue.
+ */
+ bfqq_wants_to_preempt =
+ bfq_bfqq_update_budg_for_activation(bfqd, bfqq,
+ arrived_in_time,
+ wr_or_deserves_wr);
+
+ /*
+ * If bfqq happened to be activated in a burst, but has been
+ * idle for much more than an interactive queue, then we
+ * assume that, in the overall I/O initiated in the burst, the
+ * I/O associated with bfqq is finished. So bfqq does not need
+ * to be treated as a queue belonging to a burst
+ * anymore. Accordingly, we reset bfqq's in_large_burst flag
+ * if set, and remove bfqq from the burst list if it's
+ * there. We do not decrement burst_size, because the fact
+ * that bfqq does not need to belong to the burst list any
+ * more does not invalidate the fact that bfqq was created in
+ * a burst.
+ */
+ if (likely(!bfq_bfqq_just_created(bfqq)) &&
+ idle_for_long_time &&
+ time_is_before_jiffies(
+ bfqq->budget_timeout +
+ msecs_to_jiffies(10000))) {
+ hlist_del_init(&bfqq->burst_list_node);
+ bfq_clear_bfqq_in_large_burst(bfqq);
+ }
+
+ bfq_clear_bfqq_just_created(bfqq);
+
+
+ if (!bfq_bfqq_IO_bound(bfqq)) {
+ if (arrived_in_time) {
+ bfqq->requests_within_timer++;
+ if (bfqq->requests_within_timer >=
+ bfqd->bfq_requests_within_timer)
+ bfq_mark_bfqq_IO_bound(bfqq);
+ } else
+ bfqq->requests_within_timer = 0;
+ }
+
+ if (bfqd->low_latency) {
+ if (unlikely(time_is_after_jiffies(bfqq->split_time)))
+ /* wraparound */
+ bfqq->split_time =
+ jiffies - bfqd->bfq_wr_min_idle_time - 1;
+
+ if (time_is_before_jiffies(bfqq->split_time +
+ bfqd->bfq_wr_min_idle_time)) {
+ bfq_update_bfqq_wr_on_rq_arrival(bfqd, bfqq,
+ old_wr_coeff,
+ wr_or_deserves_wr,
+ *interactive,
+ in_burst,
+ soft_rt);
+
+ if (old_wr_coeff != bfqq->wr_coeff)
+ bfqq->entity.prio_changed = 1;
+ }
+ }
+
+ bfqq->last_idle_bklogged = jiffies;
+ bfqq->service_from_backlogged = 0;
+ bfq_clear_bfqq_softrt_update(bfqq);
+
+ bfq_add_bfqq_busy(bfqd, bfqq);
+
+ /*
+ * Expire in-service queue only if preemption may be needed
+ * for guarantees. In this respect, the function
+ * next_queue_may_preempt just checks a simple, necessary
+ * condition, and not a sufficient condition based on
+ * timestamps. In fact, for the latter condition to be
+ * evaluated, timestamps would need first to be updated, and
+ * this operation is quite costly (see the comments on the
+ * function bfq_bfqq_update_budg_for_activation).
+ */
+ if (bfqd->in_service_queue && bfqq_wants_to_preempt &&
+ bfqd->in_service_queue->wr_coeff < bfqq->wr_coeff &&
+ next_queue_may_preempt(bfqd))
+ bfq_bfqq_expire(bfqd, bfqd->in_service_queue,
+ false, BFQQE_PREEMPTED);
+}
+
+static void bfq_add_request(struct request *rq)
+{
+ struct bfq_queue *bfqq = RQ_BFQQ(rq);
+ struct bfq_data *bfqd = bfqq->bfqd;
+ struct request *next_rq, *prev;
+ unsigned int old_wr_coeff = bfqq->wr_coeff;
+ bool interactive = false;
+
+ bfq_log_bfqq(bfqd, bfqq, "add_request %d", rq_is_sync(rq));
+ bfqq->queued[rq_is_sync(rq)]++;
+ bfqd->queued++;
+
+ elv_rb_add(&bfqq->sort_list, rq);
+
+ /*
+ * Check if this request is a better next-serve candidate.
+ */
+ prev = bfqq->next_rq;
+ next_rq = bfq_choose_req(bfqd, bfqq->next_rq, rq, bfqd->last_position);
+ bfqq->next_rq = next_rq;
+
+ /*
+ * Adjust priority tree position, if next_rq changes.
+ */
+ if (prev != bfqq->next_rq)
+ bfq_pos_tree_add_move(bfqd, bfqq);
+
+ if (!bfq_bfqq_busy(bfqq)) /* switching to busy ... */
+ bfq_bfqq_handle_idle_busy_switch(bfqd, bfqq, old_wr_coeff,
+ rq, &interactive);
+ else {
+ if (bfqd->low_latency && old_wr_coeff == 1 && !rq_is_sync(rq) &&
+ time_is_before_jiffies(
+ bfqq->last_wr_start_finish +
+ bfqd->bfq_wr_min_inter_arr_async)) {
+ bfqq->wr_coeff = bfqd->bfq_wr_coeff;
+ bfqq->wr_cur_max_time = bfq_wr_duration(bfqd);
+
+ bfqd->wr_busy_queues++;
+ bfqq->entity.prio_changed = 1;
+ }
+ if (prev != bfqq->next_rq)
+ bfq_updated_next_req(bfqd, bfqq);
+ }
+
+ /*
+ * Assign jiffies to last_wr_start_finish in the following
+ * cases:
+ *
+ * . if bfqq is not going to be weight-raised, because, for
+ * non weight-raised queues, last_wr_start_finish stores the
+ * arrival time of the last request; as of now, this piece
+ * of information is used only for deciding whether to
+ * weight-raise async queues
+ *
+ * . if bfqq is not weight-raised, because, if bfqq is now
+ * switching to weight-raised, then last_wr_start_finish
+ * stores the time when weight-raising starts
+ *
+ * . if bfqq is interactive, because, regardless of whether
+ * bfqq is currently weight-raised, the weight-raising
+ * period must start or restart (this case is considered
+ * separately because it is not detected by the above
+ * conditions, if bfqq is already weight-raised)
+ *
+ * last_wr_start_finish has to be updated also if bfqq is soft
+ * real-time, because the weight-raising period is constantly
+ * restarted on idle-to-busy transitions for these queues, but
+ * this is already done in bfq_bfqq_handle_idle_busy_switch if
+ * needed.
+ */
+ if (bfqd->low_latency &&
+ (old_wr_coeff == 1 || bfqq->wr_coeff == 1 || interactive))
+ bfqq->last_wr_start_finish = jiffies;
+}
+
+static struct request *bfq_find_rq_fmerge(struct bfq_data *bfqd,
+ struct bio *bio,
+ struct request_queue *q)
+{
+ struct bfq_queue *bfqq = bfqd->bio_bfqq;
+
+
+ if (bfqq)
+ return elv_rb_find(&bfqq->sort_list, bio_end_sector(bio));
+
+ return NULL;
+}
+
+static sector_t get_sdist(sector_t last_pos, struct request *rq)
+{
+ if (last_pos)
+ return abs(blk_rq_pos(rq) - last_pos);
+
+ return 0;
+}
+
+#if 0 /* Still not clear if we can do without next two functions */
+static void bfq_activate_request(struct request_queue *q, struct request *rq)
+{
+ struct bfq_data *bfqd = q->elevator->elevator_data;
+
+ bfqd->rq_in_driver++;
+}
+
+static void bfq_deactivate_request(struct request_queue *q, struct request *rq)
+{
+ struct bfq_data *bfqd = q->elevator->elevator_data;
+
+ bfqd->rq_in_driver--;
+}
+#endif
+
+static void bfq_remove_request(struct request_queue *q,
+ struct request *rq)
+{
+ struct bfq_queue *bfqq = RQ_BFQQ(rq);
+ struct bfq_data *bfqd = bfqq->bfqd;
+ const int sync = rq_is_sync(rq);
+
+ if (bfqq->next_rq == rq) {
+ bfqq->next_rq = bfq_find_next_rq(bfqd, bfqq, rq);
+ bfq_updated_next_req(bfqd, bfqq);
+ }
+
+ if (rq->queuelist.prev != &rq->queuelist)
+ list_del_init(&rq->queuelist);
+ bfqq->queued[sync]--;
+ bfqd->queued--;
+ elv_rb_del(&bfqq->sort_list, rq);
+
+ elv_rqhash_del(q, rq);
+ if (q->last_merge == rq)
+ q->last_merge = NULL;
+
+ if (RB_EMPTY_ROOT(&bfqq->sort_list)) {
+ bfqq->next_rq = NULL;
+
+ if (bfq_bfqq_busy(bfqq) && bfqq != bfqd->in_service_queue) {
+ bfq_del_bfqq_busy(bfqd, bfqq, false);
+ /*
+ * bfqq emptied. In normal operation, when
+ * bfqq is empty, bfqq->entity.service and
+ * bfqq->entity.budget must contain,
+ * respectively, the service received and the
+ * budget used last time bfqq emptied. These
+ * facts do not hold in this case, as at least
+ * this last removal occurred while bfqq is
+ * not in service. To avoid inconsistencies,
+ * reset both bfqq->entity.service and
+ * bfqq->entity.budget, if bfqq has still a
+ * process that may issue I/O requests to it.
+ */
+ bfqq->entity.budget = bfqq->entity.service = 0;
+ }
+
+ /*
+ * Remove queue from request-position tree as it is empty.
+ */
+ if (bfqq->pos_root) {
+ rb_erase(&bfqq->pos_node, bfqq->pos_root);
+ bfqq->pos_root = NULL;
+ }
+ }
+
+ if (rq->cmd_flags & REQ_META)
+ bfqq->meta_pending--;
+
+ bfqg_stats_update_io_remove(bfqq_group(bfqq), rq->cmd_flags);
+}
+
+static bool bfq_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
+{
+ struct request_queue *q = hctx->queue;
+ struct bfq_data *bfqd = q->elevator->elevator_data;
+ struct request *free = NULL;
+ /*
+ * bfq_bic_lookup grabs the queue_lock: invoke it now and
+ * store its return value for later use, to avoid nesting
+ * queue_lock inside the bfqd->lock. We assume that the bic
+ * returned by bfq_bic_lookup does not go away before
+ * bfqd->lock is taken.
+ */
+ struct bfq_io_cq *bic = bfq_bic_lookup(bfqd, current->io_context, q);
+ bool ret;
+
+ spin_lock_irq(&bfqd->lock);
+
+ if (bic)
+ bfqd->bio_bfqq = bic_to_bfqq(bic, op_is_sync(bio->bi_opf));
+ else
+ bfqd->bio_bfqq = NULL;
+ bfqd->bio_bic = bic;
+
+ ret = blk_mq_sched_try_merge(q, bio, &free);
+
+ if (free)
+ blk_mq_free_request(free);
+ spin_unlock_irq(&bfqd->lock);
+
+ return ret;
+}
+
+static int bfq_request_merge(struct request_queue *q, struct request **req,
+ struct bio *bio)
+{
+ struct bfq_data *bfqd = q->elevator->elevator_data;
+ struct request *__rq;
+
+ __rq = bfq_find_rq_fmerge(bfqd, bio, q);
+ if (__rq && elv_bio_merge_ok(__rq, bio)) {
+ *req = __rq;
+ return ELEVATOR_FRONT_MERGE;
+ }
+
+ return ELEVATOR_NO_MERGE;
+}
+
+static void bfq_request_merged(struct request_queue *q, struct request *req,
+ enum elv_merge type)
+{
+ if (type == ELEVATOR_FRONT_MERGE &&
+ rb_prev(&req->rb_node) &&
+ blk_rq_pos(req) <
+ blk_rq_pos(container_of(rb_prev(&req->rb_node),
+ struct request, rb_node))) {
+ struct bfq_queue *bfqq = RQ_BFQQ(req);
+ struct bfq_data *bfqd = bfqq->bfqd;
+ struct request *prev, *next_rq;
+
+ /* Reposition request in its sort_list */
+ elv_rb_del(&bfqq->sort_list, req);
+ elv_rb_add(&bfqq->sort_list, req);
+
+ /* Choose next request to be served for bfqq */
+ prev = bfqq->next_rq;
+ next_rq = bfq_choose_req(bfqd, bfqq->next_rq, req,
+ bfqd->last_position);
+ bfqq->next_rq = next_rq;
+ /*
+ * If next_rq changes, update both the queue's budget to
+ * fit the new request and the queue's position in its
+ * rq_pos_tree.
+ */
+ if (prev != bfqq->next_rq) {
+ bfq_updated_next_req(bfqd, bfqq);
+ bfq_pos_tree_add_move(bfqd, bfqq);
+ }
+ }
+}
+
+static void bfq_requests_merged(struct request_queue *q, struct request *rq,
+ struct request *next)
+{
+ struct bfq_queue *bfqq = RQ_BFQQ(rq), *next_bfqq = RQ_BFQQ(next);
+
+ if (!RB_EMPTY_NODE(&rq->rb_node))
+ goto end;
+
+ /*
+ * If next and rq belong to the same bfq_queue and next is older
+ * than rq, then reposition rq in the fifo (by substituting next
+ * with rq). Otherwise, if next and rq belong to different
+ * bfq_queues, never reposition rq: in fact, we would have to
+ * reposition it with respect to next's position in its own fifo,
+ * which would most certainly be too expensive with respect to
+ * the benefits.
+ */
+ if (bfqq == next_bfqq &&
+ !list_empty(&rq->queuelist) && !list_empty(&next->queuelist) &&
+ next->fifo_time < rq->fifo_time) {
+ list_del_init(&rq->queuelist);
+ list_replace_init(&next->queuelist, &rq->queuelist);
+ rq->fifo_time = next->fifo_time;
+ }
+
+ if (bfqq->next_rq == next)
+ bfqq->next_rq = rq;
+
+ bfq_remove_request(q, next);
+
+end:
+ bfqg_stats_update_io_merged(bfqq_group(bfqq), next->cmd_flags);
+}
+
+/* Must be called with bfqq != NULL */
+static void bfq_bfqq_end_wr(struct bfq_queue *bfqq)
+{
+ if (bfq_bfqq_busy(bfqq))
+ bfqq->bfqd->wr_busy_queues--;
+ bfqq->wr_coeff = 1;
+ bfqq->wr_cur_max_time = 0;
+ bfqq->last_wr_start_finish = jiffies;
+ /*
+ * Trigger a weight change on the next invocation of
+ * __bfq_entity_update_weight_prio.
+ */
+ bfqq->entity.prio_changed = 1;
+}
+
+void bfq_end_wr_async_queues(struct bfq_data *bfqd,
+ struct bfq_group *bfqg)
+{
+ int i, j;
+
+ for (i = 0; i < 2; i++)
+ for (j = 0; j < IOPRIO_BE_NR; j++)
+ if (bfqg->async_bfqq[i][j])
+ bfq_bfqq_end_wr(bfqg->async_bfqq[i][j]);
+ if (bfqg->async_idle_bfqq)
+ bfq_bfqq_end_wr(bfqg->async_idle_bfqq);
+}
+
+static void bfq_end_wr(struct bfq_data *bfqd)
+{
+ struct bfq_queue *bfqq;
+
+ spin_lock_irq(&bfqd->lock);
+
+ list_for_each_entry(bfqq, &bfqd->active_list, bfqq_list)
+ bfq_bfqq_end_wr(bfqq);
+ list_for_each_entry(bfqq, &bfqd->idle_list, bfqq_list)
+ bfq_bfqq_end_wr(bfqq);
+ bfq_end_wr_async(bfqd);
+
+ spin_unlock_irq(&bfqd->lock);
+}
+
+static sector_t bfq_io_struct_pos(void *io_struct, bool request)
+{
+ if (request)
+ return blk_rq_pos(io_struct);
+ else
+ return ((struct bio *)io_struct)->bi_iter.bi_sector;
+}
+
+static int bfq_rq_close_to_sector(void *io_struct, bool request,
+ sector_t sector)
+{
+ return abs(bfq_io_struct_pos(io_struct, request) - sector) <=
+ BFQQ_CLOSE_THR;
+}
+
+static struct bfq_queue *bfqq_find_close(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq,
+ sector_t sector)
+{
+ struct rb_root *root = &bfq_bfqq_to_bfqg(bfqq)->rq_pos_tree;
+ struct rb_node *parent, *node;
+ struct bfq_queue *__bfqq;
+
+ if (RB_EMPTY_ROOT(root))
+ return NULL;
+
+ /*
+ * First, if we find a request starting at the end of the last
+ * request, choose it.
+ */
+ __bfqq = bfq_rq_pos_tree_lookup(bfqd, root, sector, &parent, NULL);
+ if (__bfqq)
+ return __bfqq;
+
+ /*
+ * If the exact sector wasn't found, the parent of the NULL leaf
+ * will contain the closest sector (rq_pos_tree sorted by
+ * next_request position).
+ */
+ __bfqq = rb_entry(parent, struct bfq_queue, pos_node);
+ if (bfq_rq_close_to_sector(__bfqq->next_rq, true, sector))
+ return __bfqq;
+
+ if (blk_rq_pos(__bfqq->next_rq) < sector)
+ node = rb_next(&__bfqq->pos_node);
+ else
+ node = rb_prev(&__bfqq->pos_node);
+ if (!node)
+ return NULL;
+
+ __bfqq = rb_entry(node, struct bfq_queue, pos_node);
+ if (bfq_rq_close_to_sector(__bfqq->next_rq, true, sector))
+ return __bfqq;
+
+ return NULL;
+}
+
+static struct bfq_queue *bfq_find_close_cooperator(struct bfq_data *bfqd,
+ struct bfq_queue *cur_bfqq,
+ sector_t sector)
+{
+ struct bfq_queue *bfqq;
+
+ /*
+ * We shall notice if some of the queues are cooperating,
+ * e.g., working closely on the same area of the device. In
+ * that case, we can group them together and: 1) don't waste
+ * time idling, and 2) serve the union of their requests in
+ * the best possible order for throughput.
+ */
+ bfqq = bfqq_find_close(bfqd, cur_bfqq, sector);
+ if (!bfqq || bfqq == cur_bfqq)
+ return NULL;
+
+ return bfqq;
+}
+
+static struct bfq_queue *
+bfq_setup_merge(struct bfq_queue *bfqq, struct bfq_queue *new_bfqq)
+{
+ int process_refs, new_process_refs;
+ struct bfq_queue *__bfqq;
+
+ /*
+ * If there are no process references on the new_bfqq, then it is
+ * unsafe to follow the ->new_bfqq chain as other bfqq's in the chain
+ * may have dropped their last reference (not just their last process
+ * reference).
+ */
+ if (!bfqq_process_refs(new_bfqq))
+ return NULL;
+
+ /* Avoid a circular list and skip interim queue merges. */
+ while ((__bfqq = new_bfqq->new_bfqq)) {
+ if (__bfqq == bfqq)
+ return NULL;
+ new_bfqq = __bfqq;
+ }
+
+ process_refs = bfqq_process_refs(bfqq);
+ new_process_refs = bfqq_process_refs(new_bfqq);
+ /*
+ * If the process for the bfqq has gone away, there is no
+ * sense in merging the queues.
+ */
+ if (process_refs == 0 || new_process_refs == 0)
+ return NULL;
+
+ bfq_log_bfqq(bfqq->bfqd, bfqq, "scheduling merge with queue %d",
+ new_bfqq->pid);
+
+ /*
+ * Merging is just a redirection: the requests of the process
+ * owning one of the two queues are redirected to the other queue.
+ * The latter queue, in its turn, is set as shared if this is the
+ * first time that the requests of some process are redirected to
+ * it.
+ *
+ * We redirect bfqq to new_bfqq and not the opposite, because
+ * we are in the context of the process owning bfqq, thus we
+ * have the io_cq of this process. So we can immediately
+ * configure this io_cq to redirect the requests of the
+ * process to new_bfqq. In contrast, the io_cq of new_bfqq is
+ * not available any more (new_bfqq->bic == NULL).
+ *
+ * Anyway, even in case new_bfqq coincides with the in-service
+ * queue, redirecting requests the in-service queue is the
+ * best option, as we feed the in-service queue with new
+ * requests close to the last request served and, by doing so,
+ * are likely to increase the throughput.
+ */
+ bfqq->new_bfqq = new_bfqq;
+ new_bfqq->ref += process_refs;
+ return new_bfqq;
+}
+
+static bool bfq_may_be_close_cooperator(struct bfq_queue *bfqq,
+ struct bfq_queue *new_bfqq)
+{
+ if (bfq_class_idle(bfqq) || bfq_class_idle(new_bfqq) ||
+ (bfqq->ioprio_class != new_bfqq->ioprio_class))
+ return false;
+
+ /*
+ * If either of the queues has already been detected as seeky,
+ * then merging it with the other queue is unlikely to lead to
+ * sequential I/O.
+ */
+ if (BFQQ_SEEKY(bfqq) || BFQQ_SEEKY(new_bfqq))
+ return false;
+
+ /*
+ * Interleaved I/O is known to be done by (some) applications
+ * only for reads, so it does not make sense to merge async
+ * queues.
+ */
+ if (!bfq_bfqq_sync(bfqq) || !bfq_bfqq_sync(new_bfqq))
+ return false;
+
+ return true;
+}
+
+/*
+ * If this function returns true, then bfqq cannot be merged. The idea
+ * is that true cooperation happens very early after processes start
+ * to do I/O. Usually, late cooperations are just accidental false
+ * positives. In case bfqq is weight-raised, such false positives
+ * would evidently degrade latency guarantees for bfqq.
+ */
+static bool wr_from_too_long(struct bfq_queue *bfqq)
+{
+ return bfqq->wr_coeff > 1 &&
+ time_is_before_jiffies(bfqq->last_wr_start_finish +
+ msecs_to_jiffies(100));
+}
+
+/*
+ * Attempt to schedule a merge of bfqq with the currently in-service
+ * queue or with a close queue among the scheduled queues. Return
+ * NULL if no merge was scheduled, a pointer to the shared bfq_queue
+ * structure otherwise.
+ *
+ * The OOM queue is not allowed to participate to cooperation: in fact, since
+ * the requests temporarily redirected to the OOM queue could be redirected
+ * again to dedicated queues at any time, the state needed to correctly
+ * handle merging with the OOM queue would be quite complex and expensive
+ * to maintain. Besides, in such a critical condition as an out of memory,
+ * the benefits of queue merging may be little relevant, or even negligible.
+ *
+ * Weight-raised queues can be merged only if their weight-raising
+ * period has just started. In fact cooperating processes are usually
+ * started together. Thus, with this filter we avoid false positives
+ * that would jeopardize low-latency guarantees.
+ *
+ * WARNING: queue merging may impair fairness among non-weight raised
+ * queues, for at least two reasons: 1) the original weight of a
+ * merged queue may change during the merged state, 2) even being the
+ * weight the same, a merged queue may be bloated with many more
+ * requests than the ones produced by its originally-associated
+ * process.
+ */
+static struct bfq_queue *
+bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ void *io_struct, bool request)
+{
+ struct bfq_queue *in_service_bfqq, *new_bfqq;
+
+ if (bfqq->new_bfqq)
+ return bfqq->new_bfqq;
+
+ if (!io_struct ||
+ wr_from_too_long(bfqq) ||
+ unlikely(bfqq == &bfqd->oom_bfqq))
+ return NULL;
+
+ /* If there is only one backlogged queue, don't search. */
+ if (bfqd->busy_queues == 1)
+ return NULL;
+
+ in_service_bfqq = bfqd->in_service_queue;
+
+ if (!in_service_bfqq || in_service_bfqq == bfqq
+ || wr_from_too_long(in_service_bfqq) ||
+ unlikely(in_service_bfqq == &bfqd->oom_bfqq))
+ goto check_scheduled;
+
+ if (bfq_rq_close_to_sector(io_struct, request, bfqd->last_position) &&
+ bfqq->entity.parent == in_service_bfqq->entity.parent &&
+ bfq_may_be_close_cooperator(bfqq, in_service_bfqq)) {
+ new_bfqq = bfq_setup_merge(bfqq, in_service_bfqq);
+ if (new_bfqq)
+ return new_bfqq;
+ }
+ /*
+ * Check whether there is a cooperator among currently scheduled
+ * queues. The only thing we need is that the bio/request is not
+ * NULL, as we need it to establish whether a cooperator exists.
+ */
+check_scheduled:
+ new_bfqq = bfq_find_close_cooperator(bfqd, bfqq,
+ bfq_io_struct_pos(io_struct, request));
+
+ if (new_bfqq && !wr_from_too_long(new_bfqq) &&
+ likely(new_bfqq != &bfqd->oom_bfqq) &&
+ bfq_may_be_close_cooperator(bfqq, new_bfqq))
+ return bfq_setup_merge(bfqq, new_bfqq);
+
+ return NULL;
+}
+
+static void bfq_bfqq_save_state(struct bfq_queue *bfqq)
+{
+ struct bfq_io_cq *bic = bfqq->bic;
+
+ /*
+ * If !bfqq->bic, the queue is already shared or its requests
+ * have already been redirected to a shared queue; both idle window
+ * and weight raising state have already been saved. Do nothing.
+ */
+ if (!bic)
+ return;
+
+ bic->saved_ttime = bfqq->ttime;
+ bic->saved_has_short_ttime = bfq_bfqq_has_short_ttime(bfqq);
+ bic->saved_IO_bound = bfq_bfqq_IO_bound(bfqq);
+ bic->saved_in_large_burst = bfq_bfqq_in_large_burst(bfqq);
+ bic->was_in_burst_list = !hlist_unhashed(&bfqq->burst_list_node);
+ bic->saved_wr_coeff = bfqq->wr_coeff;
+ bic->saved_wr_start_at_switch_to_srt = bfqq->wr_start_at_switch_to_srt;
+ bic->saved_last_wr_start_finish = bfqq->last_wr_start_finish;
+ bic->saved_wr_cur_max_time = bfqq->wr_cur_max_time;
+}
+
+static void
+bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic,
+ struct bfq_queue *bfqq, struct bfq_queue *new_bfqq)
+{
+ bfq_log_bfqq(bfqd, bfqq, "merging with queue %lu",
+ (unsigned long)new_bfqq->pid);
+ /* Save weight raising and idle window of the merged queues */
+ bfq_bfqq_save_state(bfqq);
+ bfq_bfqq_save_state(new_bfqq);
+ if (bfq_bfqq_IO_bound(bfqq))
+ bfq_mark_bfqq_IO_bound(new_bfqq);
+ bfq_clear_bfqq_IO_bound(bfqq);
+
+ /*
+ * If bfqq is weight-raised, then let new_bfqq inherit
+ * weight-raising. To reduce false positives, neglect the case
+ * where bfqq has just been created, but has not yet made it
+ * to be weight-raised (which may happen because EQM may merge
+ * bfqq even before bfq_add_request is executed for the first
+ * time for bfqq). Handling this case would however be very
+ * easy, thanks to the flag just_created.
+ */
+ if (new_bfqq->wr_coeff == 1 && bfqq->wr_coeff > 1) {
+ new_bfqq->wr_coeff = bfqq->wr_coeff;
+ new_bfqq->wr_cur_max_time = bfqq->wr_cur_max_time;
+ new_bfqq->last_wr_start_finish = bfqq->last_wr_start_finish;
+ new_bfqq->wr_start_at_switch_to_srt =
+ bfqq->wr_start_at_switch_to_srt;
+ if (bfq_bfqq_busy(new_bfqq))
+ bfqd->wr_busy_queues++;
+ new_bfqq->entity.prio_changed = 1;
+ }
+
+ if (bfqq->wr_coeff > 1) { /* bfqq has given its wr to new_bfqq */
+ bfqq->wr_coeff = 1;
+ bfqq->entity.prio_changed = 1;
+ if (bfq_bfqq_busy(bfqq))
+ bfqd->wr_busy_queues--;
+ }
+
+ bfq_log_bfqq(bfqd, new_bfqq, "merge_bfqqs: wr_busy %d",
+ bfqd->wr_busy_queues);
+
+ /*
+ * Merge queues (that is, let bic redirect its requests to new_bfqq)
+ */
+ bic_set_bfqq(bic, new_bfqq, 1);
+ bfq_mark_bfqq_coop(new_bfqq);
+ /*
+ * new_bfqq now belongs to at least two bics (it is a shared queue):
+ * set new_bfqq->bic to NULL. bfqq either:
+ * - does not belong to any bic any more, and hence bfqq->bic must
+ * be set to NULL, or
+ * - is a queue whose owning bics have already been redirected to a
+ * different queue, hence the queue is destined to not belong to
+ * any bic soon and bfqq->bic is already NULL (therefore the next
+ * assignment causes no harm).
+ */
+ new_bfqq->bic = NULL;
+ bfqq->bic = NULL;
+ /* release process reference to bfqq */
+ bfq_put_queue(bfqq);
+}
+
+static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq,
+ struct bio *bio)
+{
+ struct bfq_data *bfqd = q->elevator->elevator_data;
+ bool is_sync = op_is_sync(bio->bi_opf);
+ struct bfq_queue *bfqq = bfqd->bio_bfqq, *new_bfqq;
+
+ /*
+ * Disallow merge of a sync bio into an async request.
+ */
+ if (is_sync && !rq_is_sync(rq))
+ return false;
+
+ /*
+ * Lookup the bfqq that this bio will be queued with. Allow
+ * merge only if rq is queued there.
+ */
+ if (!bfqq)
+ return false;
+
+ /*
+ * We take advantage of this function to perform an early merge
+ * of the queues of possible cooperating processes.
+ */
+ new_bfqq = bfq_setup_cooperator(bfqd, bfqq, bio, false);
+ if (new_bfqq) {
+ /*
+ * bic still points to bfqq, then it has not yet been
+ * redirected to some other bfq_queue, and a queue
+ * merge beween bfqq and new_bfqq can be safely
+ * fulfillled, i.e., bic can be redirected to new_bfqq
+ * and bfqq can be put.
+ */
+ bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq,
+ new_bfqq);
+ /*
+ * If we get here, bio will be queued into new_queue,
+ * so use new_bfqq to decide whether bio and rq can be
+ * merged.
+ */
+ bfqq = new_bfqq;
+
+ /*
+ * Change also bqfd->bio_bfqq, as
+ * bfqd->bio_bic now points to new_bfqq, and
+ * this function may be invoked again (and then may
+ * use again bqfd->bio_bfqq).
+ */
+ bfqd->bio_bfqq = bfqq;
+ }
+
+ return bfqq == RQ_BFQQ(rq);
+}
+
+/*
+ * Set the maximum time for the in-service queue to consume its
+ * budget. This prevents seeky processes from lowering the throughput.
+ * In practice, a time-slice service scheme is used with seeky
+ * processes.
+ */
+static void bfq_set_budget_timeout(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq)
+{
+ unsigned int timeout_coeff;
+
+ if (bfqq->wr_cur_max_time == bfqd->bfq_wr_rt_max_time)
+ timeout_coeff = 1;
+ else
+ timeout_coeff = bfqq->entity.weight / bfqq->entity.orig_weight;
+
+ bfqd->last_budget_start = ktime_get();
+
+ bfqq->budget_timeout = jiffies +
+ bfqd->bfq_timeout * timeout_coeff;
+}
+
+static void __bfq_set_in_service_queue(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq)
+{
+ if (bfqq) {
+ bfqg_stats_update_avg_queue_size(bfqq_group(bfqq));
+ bfq_clear_bfqq_fifo_expire(bfqq);
+
+ bfqd->budgets_assigned = (bfqd->budgets_assigned * 7 + 256) / 8;
+
+ if (time_is_before_jiffies(bfqq->last_wr_start_finish) &&
+ bfqq->wr_coeff > 1 &&
+ bfqq->wr_cur_max_time == bfqd->bfq_wr_rt_max_time &&
+ time_is_before_jiffies(bfqq->budget_timeout)) {
+ /*
+ * For soft real-time queues, move the start
+ * of the weight-raising period forward by the
+ * time the queue has not received any
+ * service. Otherwise, a relatively long
+ * service delay is likely to cause the
+ * weight-raising period of the queue to end,
+ * because of the short duration of the
+ * weight-raising period of a soft real-time
+ * queue. It is worth noting that this move
+ * is not so dangerous for the other queues,
+ * because soft real-time queues are not
+ * greedy.
+ *
+ * To not add a further variable, we use the
+ * overloaded field budget_timeout to
+ * determine for how long the queue has not
+ * received service, i.e., how much time has
+ * elapsed since the queue expired. However,
+ * this is a little imprecise, because
+ * budget_timeout is set to jiffies if bfqq
+ * not only expires, but also remains with no
+ * request.
+ */
+ if (time_after(bfqq->budget_timeout,
+ bfqq->last_wr_start_finish))
+ bfqq->last_wr_start_finish +=
+ jiffies - bfqq->budget_timeout;
+ else
+ bfqq->last_wr_start_finish = jiffies;
+ }
+
+ bfq_set_budget_timeout(bfqd, bfqq);
+ bfq_log_bfqq(bfqd, bfqq,
+ "set_in_service_queue, cur-budget = %d",
+ bfqq->entity.budget);
+ }
+
+ bfqd->in_service_queue = bfqq;
+}
+
+/*
+ * Get and set a new queue for service.
+ */
+static struct bfq_queue *bfq_set_in_service_queue(struct bfq_data *bfqd)
+{
+ struct bfq_queue *bfqq = bfq_get_next_queue(bfqd);
+
+ __bfq_set_in_service_queue(bfqd, bfqq);
+ return bfqq;
+}
+
+static void bfq_arm_slice_timer(struct bfq_data *bfqd)
+{
+ struct bfq_queue *bfqq = bfqd->in_service_queue;
+ u32 sl;
+
+ bfq_mark_bfqq_wait_request(bfqq);
+
+ /*
+ * We don't want to idle for seeks, but we do want to allow
+ * fair distribution of slice time for a process doing back-to-back
+ * seeks. So allow a little bit of time for him to submit a new rq.
+ */
+ sl = bfqd->bfq_slice_idle;
+ /*
+ * Unless the queue is being weight-raised or the scenario is
+ * asymmetric, grant only minimum idle time if the queue
+ * is seeky. A long idling is preserved for a weight-raised
+ * queue, or, more in general, in an asymmetric scenario,
+ * because a long idling is needed for guaranteeing to a queue
+ * its reserved share of the throughput (in particular, it is
+ * needed if the queue has a higher weight than some other
+ * queue).
+ */
+ if (BFQQ_SEEKY(bfqq) && bfqq->wr_coeff == 1 &&
+ bfq_symmetric_scenario(bfqd))
+ sl = min_t(u64, sl, BFQ_MIN_TT);
+ else if (bfqq->wr_coeff > 1)
+ sl = max_t(u32, sl, 20ULL * NSEC_PER_MSEC);
+
+ bfqd->last_idling_start = ktime_get();
+ hrtimer_start(&bfqd->idle_slice_timer, ns_to_ktime(sl),
+ HRTIMER_MODE_REL);
+ bfqg_stats_set_start_idle_time(bfqq_group(bfqq));
+}
+
+/*
+ * In autotuning mode, max_budget is dynamically recomputed as the
+ * amount of sectors transferred in timeout at the estimated peak
+ * rate. This enables BFQ to utilize a full timeslice with a full
+ * budget, even if the in-service queue is served at peak rate. And
+ * this maximises throughput with sequential workloads.
+ */
+static unsigned long bfq_calc_max_budget(struct bfq_data *bfqd)
+{
+ return (u64)bfqd->peak_rate * USEC_PER_MSEC *
+ jiffies_to_msecs(bfqd->bfq_timeout)>>BFQ_RATE_SHIFT;
+}
+
+/*
+ * Update parameters related to throughput and responsiveness, as a
+ * function of the estimated peak rate. See comments on
+ * bfq_calc_max_budget(), and on T_slow and T_fast arrays.
+ */
+static void update_thr_responsiveness_params(struct bfq_data *bfqd)
+{
+ int dev_type = blk_queue_nonrot(bfqd->queue);
+
+ if (bfqd->bfq_user_max_budget == 0)
+ bfqd->bfq_max_budget =
+ bfq_calc_max_budget(bfqd);
+
+ if (bfqd->device_speed == BFQ_BFQD_FAST &&
+ bfqd->peak_rate < device_speed_thresh[dev_type]) {
+ bfqd->device_speed = BFQ_BFQD_SLOW;
+ bfqd->RT_prod = R_slow[dev_type] *
+ T_slow[dev_type];
+ } else if (bfqd->device_speed == BFQ_BFQD_SLOW &&
+ bfqd->peak_rate > device_speed_thresh[dev_type]) {
+ bfqd->device_speed = BFQ_BFQD_FAST;
+ bfqd->RT_prod = R_fast[dev_type] *
+ T_fast[dev_type];
+ }
+
+ bfq_log(bfqd,
+"dev_type %s dev_speed_class = %s (%llu sects/sec), thresh %llu setcs/sec",
+ dev_type == 0 ? "ROT" : "NONROT",
+ bfqd->device_speed == BFQ_BFQD_FAST ? "FAST" : "SLOW",
+ bfqd->device_speed == BFQ_BFQD_FAST ?
+ (USEC_PER_SEC*(u64)R_fast[dev_type])>>BFQ_RATE_SHIFT :
+ (USEC_PER_SEC*(u64)R_slow[dev_type])>>BFQ_RATE_SHIFT,
+ (USEC_PER_SEC*(u64)device_speed_thresh[dev_type])>>
+ BFQ_RATE_SHIFT);
+}
+
+static void bfq_reset_rate_computation(struct bfq_data *bfqd,
+ struct request *rq)
+{
+ if (rq != NULL) { /* new rq dispatch now, reset accordingly */
+ bfqd->last_dispatch = bfqd->first_dispatch = ktime_get_ns();
+ bfqd->peak_rate_samples = 1;
+ bfqd->sequential_samples = 0;
+ bfqd->tot_sectors_dispatched = bfqd->last_rq_max_size =
+ blk_rq_sectors(rq);
+ } else /* no new rq dispatched, just reset the number of samples */
+ bfqd->peak_rate_samples = 0; /* full re-init on next disp. */
+
+ bfq_log(bfqd,
+ "reset_rate_computation at end, sample %u/%u tot_sects %llu",
+ bfqd->peak_rate_samples, bfqd->sequential_samples,
+ bfqd->tot_sectors_dispatched);
+}
+
+static void bfq_update_rate_reset(struct bfq_data *bfqd, struct request *rq)
+{
+ u32 rate, weight, divisor;
+
+ /*
+ * For the convergence property to hold (see comments on
+ * bfq_update_peak_rate()) and for the assessment to be
+ * reliable, a minimum number of samples must be present, and
+ * a minimum amount of time must have elapsed. If not so, do
+ * not compute new rate. Just reset parameters, to get ready
+ * for a new evaluation attempt.
+ */
+ if (bfqd->peak_rate_samples < BFQ_RATE_MIN_SAMPLES ||
+ bfqd->delta_from_first < BFQ_RATE_MIN_INTERVAL)
+ goto reset_computation;
+
+ /*
+ * If a new request completion has occurred after last
+ * dispatch, then, to approximate the rate at which requests
+ * have been served by the device, it is more precise to
+ * extend the observation interval to the last completion.
+ */
+ bfqd->delta_from_first =
+ max_t(u64, bfqd->delta_from_first,
+ bfqd->last_completion - bfqd->first_dispatch);
+
+ /*
+ * Rate computed in sects/usec, and not sects/nsec, for
+ * precision issues.
+ */
+ rate = div64_ul(bfqd->tot_sectors_dispatched<<BFQ_RATE_SHIFT,
+ div_u64(bfqd->delta_from_first, NSEC_PER_USEC));
+
+ /*
+ * Peak rate not updated if:
+ * - the percentage of sequential dispatches is below 3/4 of the
+ * total, and rate is below the current estimated peak rate
+ * - rate is unreasonably high (> 20M sectors/sec)
+ */
+ if ((bfqd->sequential_samples < (3 * bfqd->peak_rate_samples)>>2 &&
+ rate <= bfqd->peak_rate) ||
+ rate > 20<<BFQ_RATE_SHIFT)
+ goto reset_computation;
+
+ /*
+ * We have to update the peak rate, at last! To this purpose,
+ * we use a low-pass filter. We compute the smoothing constant
+ * of the filter as a function of the 'weight' of the new
+ * measured rate.
+ *
+ * As can be seen in next formulas, we define this weight as a
+ * quantity proportional to how sequential the workload is,
+ * and to how long the observation time interval is.
+ *
+ * The weight runs from 0 to 8. The maximum value of the
+ * weight, 8, yields the minimum value for the smoothing
+ * constant. At this minimum value for the smoothing constant,
+ * the measured rate contributes for half of the next value of
+ * the estimated peak rate.
+ *
+ * So, the first step is to compute the weight as a function
+ * of how sequential the workload is. Note that the weight
+ * cannot reach 9, because bfqd->sequential_samples cannot
+ * become equal to bfqd->peak_rate_samples, which, in its
+ * turn, holds true because bfqd->sequential_samples is not
+ * incremented for the first sample.
+ */
+ weight = (9 * bfqd->sequential_samples) / bfqd->peak_rate_samples;
+
+ /*
+ * Second step: further refine the weight as a function of the
+ * duration of the observation interval.
+ */
+ weight = min_t(u32, 8,
+ div_u64(weight * bfqd->delta_from_first,
+ BFQ_RATE_REF_INTERVAL));
+
+ /*
+ * Divisor ranging from 10, for minimum weight, to 2, for
+ * maximum weight.
+ */
+ divisor = 10 - weight;
+
+ /*
+ * Finally, update peak rate:
+ *
+ * peak_rate = peak_rate * (divisor-1) / divisor + rate / divisor
+ */
+ bfqd->peak_rate *= divisor-1;
+ bfqd->peak_rate /= divisor;
+ rate /= divisor; /* smoothing constant alpha = 1/divisor */
+
+ bfqd->peak_rate += rate;
+ update_thr_responsiveness_params(bfqd);
+
+reset_computation:
+ bfq_reset_rate_computation(bfqd, rq);
+}
+
+/*
+ * Update the read/write peak rate (the main quantity used for
+ * auto-tuning, see update_thr_responsiveness_params()).
+ *
+ * It is not trivial to estimate the peak rate (correctly): because of
+ * the presence of sw and hw queues between the scheduler and the
+ * device components that finally serve I/O requests, it is hard to
+ * say exactly when a given dispatched request is served inside the
+ * device, and for how long. As a consequence, it is hard to know
+ * precisely at what rate a given set of requests is actually served
+ * by the device.
+ *
+ * On the opposite end, the dispatch time of any request is trivially
+ * available, and, from this piece of information, the "dispatch rate"
+ * of requests can be immediately computed. So, the idea in the next
+ * function is to use what is known, namely request dispatch times
+ * (plus, when useful, request completion times), to estimate what is
+ * unknown, namely in-device request service rate.
+ *
+ * The main issue is that, because of the above facts, the rate at
+ * which a certain set of requests is dispatched over a certain time
+ * interval can vary greatly with respect to the rate at which the
+ * same requests are then served. But, since the size of any
+ * intermediate queue is limited, and the service scheme is lossless
+ * (no request is silently dropped), the following obvious convergence
+ * property holds: the number of requests dispatched MUST become
+ * closer and closer to the number of requests completed as the
+ * observation interval grows. This is the key property used in
+ * the next function to estimate the peak service rate as a function
+ * of the observed dispatch rate. The function assumes to be invoked
+ * on every request dispatch.
+ */
+static void bfq_update_peak_rate(struct bfq_data *bfqd, struct request *rq)
+{
+ u64 now_ns = ktime_get_ns();
+
+ if (bfqd->peak_rate_samples == 0) { /* first dispatch */
+ bfq_log(bfqd, "update_peak_rate: goto reset, samples %d",
+ bfqd->peak_rate_samples);
+ bfq_reset_rate_computation(bfqd, rq);
+ goto update_last_values; /* will add one sample */
+ }
+
+ /*
+ * Device idle for very long: the observation interval lasting
+ * up to this dispatch cannot be a valid observation interval
+ * for computing a new peak rate (similarly to the late-
+ * completion event in bfq_completed_request()). Go to
+ * update_rate_and_reset to have the following three steps
+ * taken:
+ * - close the observation interval at the last (previous)
+ * request dispatch or completion
+ * - compute rate, if possible, for that observation interval
+ * - start a new observation interval with this dispatch
+ */
+ if (now_ns - bfqd->last_dispatch > 100*NSEC_PER_MSEC &&
+ bfqd->rq_in_driver == 0)
+ goto update_rate_and_reset;
+
+ /* Update sampling information */
+ bfqd->peak_rate_samples++;
+
+ if ((bfqd->rq_in_driver > 0 ||
+ now_ns - bfqd->last_completion < BFQ_MIN_TT)
+ && get_sdist(bfqd->last_position, rq) < BFQQ_SEEK_THR)
+ bfqd->sequential_samples++;
+
+ bfqd->tot_sectors_dispatched += blk_rq_sectors(rq);
+
+ /* Reset max observed rq size every 32 dispatches */
+ if (likely(bfqd->peak_rate_samples % 32))
+ bfqd->last_rq_max_size =
+ max_t(u32, blk_rq_sectors(rq), bfqd->last_rq_max_size);
+ else
+ bfqd->last_rq_max_size = blk_rq_sectors(rq);
+
+ bfqd->delta_from_first = now_ns - bfqd->first_dispatch;
+
+ /* Target observation interval not yet reached, go on sampling */
+ if (bfqd->delta_from_first < BFQ_RATE_REF_INTERVAL)
+ goto update_last_values;
+
+update_rate_and_reset:
+ bfq_update_rate_reset(bfqd, rq);
+update_last_values:
+ bfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq);
+ bfqd->last_dispatch = now_ns;
+}
+
+/*
+ * Remove request from internal lists.
+ */
+static void bfq_dispatch_remove(struct request_queue *q, struct request *rq)
+{
+ struct bfq_queue *bfqq = RQ_BFQQ(rq);
+
+ /*
+ * For consistency, the next instruction should have been
+ * executed after removing the request from the queue and
+ * dispatching it. We execute instead this instruction before
+ * bfq_remove_request() (and hence introduce a temporary
+ * inconsistency), for efficiency. In fact, should this
+ * dispatch occur for a non in-service bfqq, this anticipated
+ * increment prevents two counters related to bfqq->dispatched
+ * from risking to be, first, uselessly decremented, and then
+ * incremented again when the (new) value of bfqq->dispatched
+ * happens to be taken into account.
+ */
+ bfqq->dispatched++;
+ bfq_update_peak_rate(q->elevator->elevator_data, rq);
+
+ bfq_remove_request(q, rq);
+}
+
+static void __bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ /*
+ * If this bfqq is shared between multiple processes, check
+ * to make sure that those processes are still issuing I/Os
+ * within the mean seek distance. If not, it may be time to
+ * break the queues apart again.
+ */
+ if (bfq_bfqq_coop(bfqq) && BFQQ_SEEKY(bfqq))
+ bfq_mark_bfqq_split_coop(bfqq);
+
+ if (RB_EMPTY_ROOT(&bfqq->sort_list)) {
+ if (bfqq->dispatched == 0)
+ /*
+ * Overloading budget_timeout field to store
+ * the time at which the queue remains with no
+ * backlog and no outstanding request; used by
+ * the weight-raising mechanism.
+ */
+ bfqq->budget_timeout = jiffies;
+
+ bfq_del_bfqq_busy(bfqd, bfqq, true);
+ } else {
+ bfq_requeue_bfqq(bfqd, bfqq, true);
+ /*
+ * Resort priority tree of potential close cooperators.
+ */
+ bfq_pos_tree_add_move(bfqd, bfqq);
+ }
+
+ /*
+ * All in-service entities must have been properly deactivated
+ * or requeued before executing the next function, which
+ * resets all in-service entites as no more in service.
+ */
+ __bfq_bfqd_reset_in_service(bfqd);
+}
+
+/**
+ * __bfq_bfqq_recalc_budget - try to adapt the budget to the @bfqq behavior.
+ * @bfqd: device data.
+ * @bfqq: queue to update.
+ * @reason: reason for expiration.
+ *
+ * Handle the feedback on @bfqq budget at queue expiration.
+ * See the body for detailed comments.
+ */
+static void __bfq_bfqq_recalc_budget(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq,
+ enum bfqq_expiration reason)
+{
+ struct request *next_rq;
+ int budget, min_budget;
+
+ min_budget = bfq_min_budget(bfqd);
+
+ if (bfqq->wr_coeff == 1)
+ budget = bfqq->max_budget;
+ else /*
+ * Use a constant, low budget for weight-raised queues,
+ * to help achieve a low latency. Keep it slightly higher
+ * than the minimum possible budget, to cause a little
+ * bit fewer expirations.
+ */
+ budget = 2 * min_budget;
+
+ bfq_log_bfqq(bfqd, bfqq, "recalc_budg: last budg %d, budg left %d",
+ bfqq->entity.budget, bfq_bfqq_budget_left(bfqq));
+ bfq_log_bfqq(bfqd, bfqq, "recalc_budg: last max_budg %d, min budg %d",
+ budget, bfq_min_budget(bfqd));
+ bfq_log_bfqq(bfqd, bfqq, "recalc_budg: sync %d, seeky %d",
+ bfq_bfqq_sync(bfqq), BFQQ_SEEKY(bfqd->in_service_queue));
+
+ if (bfq_bfqq_sync(bfqq) && bfqq->wr_coeff == 1) {
+ switch (reason) {
+ /*
+ * Caveat: in all the following cases we trade latency
+ * for throughput.
+ */
+ case BFQQE_TOO_IDLE:
+ /*
+ * This is the only case where we may reduce
+ * the budget: if there is no request of the
+ * process still waiting for completion, then
+ * we assume (tentatively) that the timer has
+ * expired because the batch of requests of
+ * the process could have been served with a
+ * smaller budget. Hence, betting that
+ * process will behave in the same way when it
+ * becomes backlogged again, we reduce its
+ * next budget. As long as we guess right,
+ * this budget cut reduces the latency
+ * experienced by the process.
+ *
+ * However, if there are still outstanding
+ * requests, then the process may have not yet
+ * issued its next request just because it is
+ * still waiting for the completion of some of
+ * the still outstanding ones. So in this
+ * subcase we do not reduce its budget, on the
+ * contrary we increase it to possibly boost
+ * the throughput, as discussed in the
+ * comments to the BUDGET_TIMEOUT case.
+ */
+ if (bfqq->dispatched > 0) /* still outstanding reqs */
+ budget = min(budget * 2, bfqd->bfq_max_budget);
+ else {
+ if (budget > 5 * min_budget)
+ budget -= 4 * min_budget;
+ else
+ budget = min_budget;
+ }
+ break;
+ case BFQQE_BUDGET_TIMEOUT:
+ /*
+ * We double the budget here because it gives
+ * the chance to boost the throughput if this
+ * is not a seeky process (and has bumped into
+ * this timeout because of, e.g., ZBR).
+ */
+ budget = min(budget * 2, bfqd->bfq_max_budget);
+ break;
+ case BFQQE_BUDGET_EXHAUSTED:
+ /*
+ * The process still has backlog, and did not
+ * let either the budget timeout or the disk
+ * idling timeout expire. Hence it is not
+ * seeky, has a short thinktime and may be
+ * happy with a higher budget too. So
+ * definitely increase the budget of this good
+ * candidate to boost the disk throughput.
+ */
+ budget = min(budget * 4, bfqd->bfq_max_budget);
+ break;
+ case BFQQE_NO_MORE_REQUESTS:
+ /*
+ * For queues that expire for this reason, it
+ * is particularly important to keep the
+ * budget close to the actual service they
+ * need. Doing so reduces the timestamp
+ * misalignment problem described in the
+ * comments in the body of
+ * __bfq_activate_entity. In fact, suppose
+ * that a queue systematically expires for
+ * BFQQE_NO_MORE_REQUESTS and presents a
+ * new request in time to enjoy timestamp
+ * back-shifting. The larger the budget of the
+ * queue is with respect to the service the
+ * queue actually requests in each service
+ * slot, the more times the queue can be
+ * reactivated with the same virtual finish
+ * time. It follows that, even if this finish
+ * time is pushed to the system virtual time
+ * to reduce the consequent timestamp
+ * misalignment, the queue unjustly enjoys for
+ * many re-activations a lower finish time
+ * than all newly activated queues.
+ *
+ * The service needed by bfqq is measured
+ * quite precisely by bfqq->entity.service.
+ * Since bfqq does not enjoy device idling,
+ * bfqq->entity.service is equal to the number
+ * of sectors that the process associated with
+ * bfqq requested to read/write before waiting
+ * for request completions, or blocking for
+ * other reasons.
+ */
+ budget = max_t(int, bfqq->entity.service, min_budget);
+ break;
+ default:
+ return;
+ }
+ } else if (!bfq_bfqq_sync(bfqq)) {
+ /*
+ * Async queues get always the maximum possible
+ * budget, as for them we do not care about latency
+ * (in addition, their ability to dispatch is limited
+ * by the charging factor).
+ */
+ budget = bfqd->bfq_max_budget;
+ }
+
+ bfqq->max_budget = budget;
+
+ if (bfqd->budgets_assigned >= bfq_stats_min_budgets &&
+ !bfqd->bfq_user_max_budget)
+ bfqq->max_budget = min(bfqq->max_budget, bfqd->bfq_max_budget);
+
+ /*
+ * If there is still backlog, then assign a new budget, making
+ * sure that it is large enough for the next request. Since
+ * the finish time of bfqq must be kept in sync with the
+ * budget, be sure to call __bfq_bfqq_expire() *after* this
+ * update.
+ *
+ * If there is no backlog, then no need to update the budget;
+ * it will be updated on the arrival of a new request.
+ */
+ next_rq = bfqq->next_rq;
+ if (next_rq)
+ bfqq->entity.budget = max_t(unsigned long, bfqq->max_budget,
+ bfq_serv_to_charge(next_rq, bfqq));
+
+ bfq_log_bfqq(bfqd, bfqq, "head sect: %u, new budget %d",
+ next_rq ? blk_rq_sectors(next_rq) : 0,
+ bfqq->entity.budget);
+}
+
+/*
+ * Return true if the process associated with bfqq is "slow". The slow
+ * flag is used, in addition to the budget timeout, to reduce the
+ * amount of service provided to seeky processes, and thus reduce
+ * their chances to lower the throughput. More details in the comments
+ * on the function bfq_bfqq_expire().
+ *
+ * An important observation is in order: as discussed in the comments
+ * on the function bfq_update_peak_rate(), with devices with internal
+ * queues, it is hard if ever possible to know when and for how long
+ * an I/O request is processed by the device (apart from the trivial
+ * I/O pattern where a new request is dispatched only after the
+ * previous one has been completed). This makes it hard to evaluate
+ * the real rate at which the I/O requests of each bfq_queue are
+ * served. In fact, for an I/O scheduler like BFQ, serving a
+ * bfq_queue means just dispatching its requests during its service
+ * slot (i.e., until the budget of the queue is exhausted, or the
+ * queue remains idle, or, finally, a timeout fires). But, during the
+ * service slot of a bfq_queue, around 100 ms at most, the device may
+ * be even still processing requests of bfq_queues served in previous
+ * service slots. On the opposite end, the requests of the in-service
+ * bfq_queue may be completed after the service slot of the queue
+ * finishes.
+ *
+ * Anyway, unless more sophisticated solutions are used
+ * (where possible), the sum of the sizes of the requests dispatched
+ * during the service slot of a bfq_queue is probably the only
+ * approximation available for the service received by the bfq_queue
+ * during its service slot. And this sum is the quantity used in this
+ * function to evaluate the I/O speed of a process.
+ */
+static bool bfq_bfqq_is_slow(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ bool compensate, enum bfqq_expiration reason,
+ unsigned long *delta_ms)
+{
+ ktime_t delta_ktime;
+ u32 delta_usecs;
+ bool slow = BFQQ_SEEKY(bfqq); /* if delta too short, use seekyness */
+
+ if (!bfq_bfqq_sync(bfqq))
+ return false;
+
+ if (compensate)
+ delta_ktime = bfqd->last_idling_start;
+ else
+ delta_ktime = ktime_get();
+ delta_ktime = ktime_sub(delta_ktime, bfqd->last_budget_start);
+ delta_usecs = ktime_to_us(delta_ktime);
+
+ /* don't use too short time intervals */
+ if (delta_usecs < 1000) {
+ if (blk_queue_nonrot(bfqd->queue))
+ /*
+ * give same worst-case guarantees as idling
+ * for seeky
+ */
+ *delta_ms = BFQ_MIN_TT / NSEC_PER_MSEC;
+ else /* charge at least one seek */
+ *delta_ms = bfq_slice_idle / NSEC_PER_MSEC;
+
+ return slow;
+ }
+
+ *delta_ms = delta_usecs / USEC_PER_MSEC;
+
+ /*
+ * Use only long (> 20ms) intervals to filter out excessive
+ * spikes in service rate estimation.
+ */
+ if (delta_usecs > 20000) {
+ /*
+ * Caveat for rotational devices: processes doing I/O
+ * in the slower disk zones tend to be slow(er) even
+ * if not seeky. In this respect, the estimated peak
+ * rate is likely to be an average over the disk
+ * surface. Accordingly, to not be too harsh with
+ * unlucky processes, a process is deemed slow only if
+ * its rate has been lower than half of the estimated
+ * peak rate.
+ */
+ slow = bfqq->entity.service < bfqd->bfq_max_budget / 2;
+ }
+
+ bfq_log_bfqq(bfqd, bfqq, "bfq_bfqq_is_slow: slow %d", slow);
+
+ return slow;
+}
+
+/*
+ * To be deemed as soft real-time, an application must meet two
+ * requirements. First, the application must not require an average
+ * bandwidth higher than the approximate bandwidth required to playback or
+ * record a compressed high-definition video.
+ * The next function is invoked on the completion of the last request of a
+ * batch, to compute the next-start time instant, soft_rt_next_start, such
+ * that, if the next request of the application does not arrive before
+ * soft_rt_next_start, then the above requirement on the bandwidth is met.
+ *
+ * The second requirement is that the request pattern of the application is
+ * isochronous, i.e., that, after issuing a request or a batch of requests,
+ * the application stops issuing new requests until all its pending requests
+ * have been completed. After that, the application may issue a new batch,
+ * and so on.
+ * For this reason the next function is invoked to compute
+ * soft_rt_next_start only for applications that meet this requirement,
+ * whereas soft_rt_next_start is set to infinity for applications that do
+ * not.
+ *
+ * Unfortunately, even a greedy application may happen to behave in an
+ * isochronous way if the CPU load is high. In fact, the application may
+ * stop issuing requests while the CPUs are busy serving other processes,
+ * then restart, then stop again for a while, and so on. In addition, if
+ * the disk achieves a low enough throughput with the request pattern
+ * issued by the application (e.g., because the request pattern is random
+ * and/or the device is slow), then the application may meet the above
+ * bandwidth requirement too. To prevent such a greedy application to be
+ * deemed as soft real-time, a further rule is used in the computation of
+ * soft_rt_next_start: soft_rt_next_start must be higher than the current
+ * time plus the maximum time for which the arrival of a request is waited
+ * for when a sync queue becomes idle, namely bfqd->bfq_slice_idle.
+ * This filters out greedy applications, as the latter issue instead their
+ * next request as soon as possible after the last one has been completed
+ * (in contrast, when a batch of requests is completed, a soft real-time
+ * application spends some time processing data).
+ *
+ * Unfortunately, the last filter may easily generate false positives if
+ * only bfqd->bfq_slice_idle is used as a reference time interval and one
+ * or both the following cases occur:
+ * 1) HZ is so low that the duration of a jiffy is comparable to or higher
+ * than bfqd->bfq_slice_idle. This happens, e.g., on slow devices with
+ * HZ=100.
+ * 2) jiffies, instead of increasing at a constant rate, may stop increasing
+ * for a while, then suddenly 'jump' by several units to recover the lost
+ * increments. This seems to happen, e.g., inside virtual machines.
+ * To address this issue, we do not use as a reference time interval just
+ * bfqd->bfq_slice_idle, but bfqd->bfq_slice_idle plus a few jiffies. In
+ * particular we add the minimum number of jiffies for which the filter
+ * seems to be quite precise also in embedded systems and KVM/QEMU virtual
+ * machines.
+ */
+static unsigned long bfq_bfqq_softrt_next_start(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq)
+{
+ return max(bfqq->last_idle_bklogged +
+ HZ * bfqq->service_from_backlogged /
+ bfqd->bfq_wr_max_softrt_rate,
+ jiffies + nsecs_to_jiffies(bfqq->bfqd->bfq_slice_idle) + 4);
+}
+
+/**
+ * bfq_bfqq_expire - expire a queue.
+ * @bfqd: device owning the queue.
+ * @bfqq: the queue to expire.
+ * @compensate: if true, compensate for the time spent idling.
+ * @reason: the reason causing the expiration.
+ *
+ * If the process associated with bfqq does slow I/O (e.g., because it
+ * issues random requests), we charge bfqq with the time it has been
+ * in service instead of the service it has received (see
+ * bfq_bfqq_charge_time for details on how this goal is achieved). As
+ * a consequence, bfqq will typically get higher timestamps upon
+ * reactivation, and hence it will be rescheduled as if it had
+ * received more service than what it has actually received. In the
+ * end, bfqq receives less service in proportion to how slowly its
+ * associated process consumes its budgets (and hence how seriously it
+ * tends to lower the throughput). In addition, this time-charging
+ * strategy guarantees time fairness among slow processes. In
+ * contrast, if the process associated with bfqq is not slow, we
+ * charge bfqq exactly with the service it has received.
+ *
+ * Charging time to the first type of queues and the exact service to
+ * the other has the effect of using the WF2Q+ policy to schedule the
+ * former on a timeslice basis, without violating service domain
+ * guarantees among the latter.
+ */
+void bfq_bfqq_expire(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq,
+ bool compensate,
+ enum bfqq_expiration reason)
+{
+ bool slow;
+ unsigned long delta = 0;
+ struct bfq_entity *entity = &bfqq->entity;
+ int ref;
+
+ /*
+ * Check whether the process is slow (see bfq_bfqq_is_slow).
+ */
+ slow = bfq_bfqq_is_slow(bfqd, bfqq, compensate, reason, &delta);
+
+ /*
+ * Increase service_from_backlogged before next statement,
+ * because the possible next invocation of
+ * bfq_bfqq_charge_time would likely inflate
+ * entity->service. In contrast, service_from_backlogged must
+ * contain real service, to enable the soft real-time
+ * heuristic to correctly compute the bandwidth consumed by
+ * bfqq.
+ */
+ bfqq->service_from_backlogged += entity->service;
+
+ /*
+ * As above explained, charge slow (typically seeky) and
+ * timed-out queues with the time and not the service
+ * received, to favor sequential workloads.
+ *
+ * Processes doing I/O in the slower disk zones will tend to
+ * be slow(er) even if not seeky. Therefore, since the
+ * estimated peak rate is actually an average over the disk
+ * surface, these processes may timeout just for bad luck. To
+ * avoid punishing them, do not charge time to processes that
+ * succeeded in consuming at least 2/3 of their budget. This
+ * allows BFQ to preserve enough elasticity to still perform
+ * bandwidth, and not time, distribution with little unlucky
+ * or quasi-sequential processes.
+ */
+ if (bfqq->wr_coeff == 1 &&
+ (slow ||
+ (reason == BFQQE_BUDGET_TIMEOUT &&
+ bfq_bfqq_budget_left(bfqq) >= entity->budget / 3)))
+ bfq_bfqq_charge_time(bfqd, bfqq, delta);
+
+ if (reason == BFQQE_TOO_IDLE &&
+ entity->service <= 2 * entity->budget / 10)
+ bfq_clear_bfqq_IO_bound(bfqq);
+
+ if (bfqd->low_latency && bfqq->wr_coeff == 1)
+ bfqq->last_wr_start_finish = jiffies;
+
+ if (bfqd->low_latency && bfqd->bfq_wr_max_softrt_rate > 0 &&
+ RB_EMPTY_ROOT(&bfqq->sort_list)) {
+ /*
+ * If we get here, and there are no outstanding
+ * requests, then the request pattern is isochronous
+ * (see the comments on the function
+ * bfq_bfqq_softrt_next_start()). Thus we can compute
+ * soft_rt_next_start. If, instead, the queue still
+ * has outstanding requests, then we have to wait for
+ * the completion of all the outstanding requests to
+ * discover whether the request pattern is actually
+ * isochronous.
+ */
+ if (bfqq->dispatched == 0)
+ bfqq->soft_rt_next_start =
+ bfq_bfqq_softrt_next_start(bfqd, bfqq);
+ else {
+ /*
+ * The application is still waiting for the
+ * completion of one or more requests:
+ * prevent it from possibly being incorrectly
+ * deemed as soft real-time by setting its
+ * soft_rt_next_start to infinity. In fact,
+ * without this assignment, the application
+ * would be incorrectly deemed as soft
+ * real-time if:
+ * 1) it issued a new request before the
+ * completion of all its in-flight
+ * requests, and
+ * 2) at that time, its soft_rt_next_start
+ * happened to be in the past.
+ */
+ bfqq->soft_rt_next_start =
+ bfq_greatest_from_now();
+ /*
+ * Schedule an update of soft_rt_next_start to when
+ * the task may be discovered to be isochronous.
+ */
+ bfq_mark_bfqq_softrt_update(bfqq);
+ }
+ }
+
+ bfq_log_bfqq(bfqd, bfqq,
+ "expire (%d, slow %d, num_disp %d, short_ttime %d)", reason,
+ slow, bfqq->dispatched, bfq_bfqq_has_short_ttime(bfqq));
+
+ /*
+ * Increase, decrease or leave budget unchanged according to
+ * reason.
+ */
+ __bfq_bfqq_recalc_budget(bfqd, bfqq, reason);
+ ref = bfqq->ref;
+ __bfq_bfqq_expire(bfqd, bfqq);
+
+ /* mark bfqq as waiting a request only if a bic still points to it */
+ if (ref > 1 && !bfq_bfqq_busy(bfqq) &&
+ reason != BFQQE_BUDGET_TIMEOUT &&
+ reason != BFQQE_BUDGET_EXHAUSTED)
+ bfq_mark_bfqq_non_blocking_wait_rq(bfqq);
+}
+
+/*
+ * Budget timeout is not implemented through a dedicated timer, but
+ * just checked on request arrivals and completions, as well as on
+ * idle timer expirations.
+ */
+static bool bfq_bfqq_budget_timeout(struct bfq_queue *bfqq)
+{
+ return time_is_before_eq_jiffies(bfqq->budget_timeout);
+}
+
+/*
+ * If we expire a queue that is actively waiting (i.e., with the
+ * device idled) for the arrival of a new request, then we may incur
+ * the timestamp misalignment problem described in the body of the
+ * function __bfq_activate_entity. Hence we return true only if this
+ * condition does not hold, or if the queue is slow enough to deserve
+ * only to be kicked off for preserving a high throughput.
+ */
+static bool bfq_may_expire_for_budg_timeout(struct bfq_queue *bfqq)
+{
+ bfq_log_bfqq(bfqq->bfqd, bfqq,
+ "may_budget_timeout: wait_request %d left %d timeout %d",
+ bfq_bfqq_wait_request(bfqq),
+ bfq_bfqq_budget_left(bfqq) >= bfqq->entity.budget / 3,
+ bfq_bfqq_budget_timeout(bfqq));
+
+ return (!bfq_bfqq_wait_request(bfqq) ||
+ bfq_bfqq_budget_left(bfqq) >= bfqq->entity.budget / 3)
+ &&
+ bfq_bfqq_budget_timeout(bfqq);
+}
+
+/*
+ * For a queue that becomes empty, device idling is allowed only if
+ * this function returns true for the queue. As a consequence, since
+ * device idling plays a critical role in both throughput boosting and
+ * service guarantees, the return value of this function plays a
+ * critical role in both these aspects as well.
+ *
+ * In a nutshell, this function returns true only if idling is
+ * beneficial for throughput or, even if detrimental for throughput,
+ * idling is however necessary to preserve service guarantees (low
+ * latency, desired throughput distribution, ...). In particular, on
+ * NCQ-capable devices, this function tries to return false, so as to
+ * help keep the drives' internal queues full, whenever this helps the
+ * device boost the throughput without causing any service-guarantee
+ * issue.
+ *
+ * In more detail, the return value of this function is obtained by,
+ * first, computing a number of boolean variables that take into
+ * account throughput and service-guarantee issues, and, then,
+ * combining these variables in a logical expression. Most of the
+ * issues taken into account are not trivial. We discuss these issues
+ * individually while introducing the variables.
+ */
+static bool bfq_bfqq_may_idle(struct bfq_queue *bfqq)
+{
+ struct bfq_data *bfqd = bfqq->bfqd;
+ bool rot_without_queueing =
+ !blk_queue_nonrot(bfqd->queue) && !bfqd->hw_tag,
+ bfqq_sequential_and_IO_bound,
+ idling_boosts_thr, idling_boosts_thr_without_issues,
+ idling_needed_for_service_guarantees,
+ asymmetric_scenario;
+
+ if (bfqd->strict_guarantees)
+ return true;
+
+ /*
+ * Idling is performed only if slice_idle > 0. In addition, we
+ * do not idle if
+ * (a) bfqq is async
+ * (b) bfqq is in the idle io prio class: in this case we do
+ * not idle because we want to minimize the bandwidth that
+ * queues in this class can steal to higher-priority queues
+ */
+ if (bfqd->bfq_slice_idle == 0 || !bfq_bfqq_sync(bfqq) ||
+ bfq_class_idle(bfqq))
+ return false;
+
+ bfqq_sequential_and_IO_bound = !BFQQ_SEEKY(bfqq) &&
+ bfq_bfqq_IO_bound(bfqq) && bfq_bfqq_has_short_ttime(bfqq);
+
+ /*
+ * The next variable takes into account the cases where idling
+ * boosts the throughput.
+ *
+ * The value of the variable is computed considering, first, that
+ * idling is virtually always beneficial for the throughput if:
+ * (a) the device is not NCQ-capable and rotational, or
+ * (b) regardless of the presence of NCQ, the device is rotational and
+ * the request pattern for bfqq is I/O-bound and sequential, or
+ * (c) regardless of whether it is rotational, the device is
+ * not NCQ-capable and the request pattern for bfqq is
+ * I/O-bound and sequential.
+ *
+ * Secondly, and in contrast to the above item (b), idling an
+ * NCQ-capable flash-based device would not boost the
+ * throughput even with sequential I/O; rather it would lower
+ * the throughput in proportion to how fast the device
+ * is. Accordingly, the next variable is true if any of the
+ * above conditions (a), (b) or (c) is true, and, in
+ * particular, happens to be false if bfqd is an NCQ-capable
+ * flash-based device.
+ */
+ idling_boosts_thr = rot_without_queueing ||
+ ((!blk_queue_nonrot(bfqd->queue) || !bfqd->hw_tag) &&
+ bfqq_sequential_and_IO_bound);
+
+ /*
+ * The value of the next variable,
+ * idling_boosts_thr_without_issues, is equal to that of
+ * idling_boosts_thr, unless a special case holds. In this
+ * special case, described below, idling may cause problems to
+ * weight-raised queues.
+ *
+ * When the request pool is saturated (e.g., in the presence
+ * of write hogs), if the processes associated with
+ * non-weight-raised queues ask for requests at a lower rate,
+ * then processes associated with weight-raised queues have a
+ * higher probability to get a request from the pool
+ * immediately (or at least soon) when they need one. Thus
+ * they have a higher probability to actually get a fraction
+ * of the device throughput proportional to their high
+ * weight. This is especially true with NCQ-capable drives,
+ * which enqueue several requests in advance, and further
+ * reorder internally-queued requests.
+ *
+ * For this reason, we force to false the value of
+ * idling_boosts_thr_without_issues if there are weight-raised
+ * busy queues. In this case, and if bfqq is not weight-raised,
+ * this guarantees that the device is not idled for bfqq (if,
+ * instead, bfqq is weight-raised, then idling will be
+ * guaranteed by another variable, see below). Combined with
+ * the timestamping rules of BFQ (see [1] for details), this
+ * behavior causes bfqq, and hence any sync non-weight-raised
+ * queue, to get a lower number of requests served, and thus
+ * to ask for a lower number of requests from the request
+ * pool, before the busy weight-raised queues get served
+ * again. This often mitigates starvation problems in the
+ * presence of heavy write workloads and NCQ, thereby
+ * guaranteeing a higher application and system responsiveness
+ * in these hostile scenarios.
+ */
+ idling_boosts_thr_without_issues = idling_boosts_thr &&
+ bfqd->wr_busy_queues == 0;
+
+ /*
+ * There is then a case where idling must be performed not
+ * for throughput concerns, but to preserve service
+ * guarantees.
+ *
+ * To introduce this case, we can note that allowing the drive
+ * to enqueue more than one request at a time, and hence
+ * delegating de facto final scheduling decisions to the
+ * drive's internal scheduler, entails loss of control on the
+ * actual request service order. In particular, the critical
+ * situation is when requests from different processes happen
+ * to be present, at the same time, in the internal queue(s)
+ * of the drive. In such a situation, the drive, by deciding
+ * the service order of the internally-queued requests, does
+ * determine also the actual throughput distribution among
+ * these processes. But the drive typically has no notion or
+ * concern about per-process throughput distribution, and
+ * makes its decisions only on a per-request basis. Therefore,
+ * the service distribution enforced by the drive's internal
+ * scheduler is likely to coincide with the desired
+ * device-throughput distribution only in a completely
+ * symmetric scenario where:
+ * (i) each of these processes must get the same throughput as
+ * the others;
+ * (ii) all these processes have the same I/O pattern
+ (either sequential or random).
+ * In fact, in such a scenario, the drive will tend to treat
+ * the requests of each of these processes in about the same
+ * way as the requests of the others, and thus to provide
+ * each of these processes with about the same throughput
+ * (which is exactly the desired throughput distribution). In
+ * contrast, in any asymmetric scenario, device idling is
+ * certainly needed to guarantee that bfqq receives its
+ * assigned fraction of the device throughput (see [1] for
+ * details).
+ *
+ * We address this issue by controlling, actually, only the
+ * symmetry sub-condition (i), i.e., provided that
+ * sub-condition (i) holds, idling is not performed,
+ * regardless of whether sub-condition (ii) holds. In other
+ * words, only if sub-condition (i) holds, then idling is
+ * allowed, and the device tends to be prevented from queueing
+ * many requests, possibly of several processes. The reason
+ * for not controlling also sub-condition (ii) is that we
+ * exploit preemption to preserve guarantees in case of
+ * symmetric scenarios, even if (ii) does not hold, as
+ * explained in the next two paragraphs.
+ *
+ * Even if a queue, say Q, is expired when it remains idle, Q
+ * can still preempt the new in-service queue if the next
+ * request of Q arrives soon (see the comments on
+ * bfq_bfqq_update_budg_for_activation). If all queues and
+ * groups have the same weight, this form of preemption,
+ * combined with the hole-recovery heuristic described in the
+ * comments on function bfq_bfqq_update_budg_for_activation,
+ * are enough to preserve a correct bandwidth distribution in
+ * the mid term, even without idling. In fact, even if not
+ * idling allows the internal queues of the device to contain
+ * many requests, and thus to reorder requests, we can rather
+ * safely assume that the internal scheduler still preserves a
+ * minimum of mid-term fairness. The motivation for using
+ * preemption instead of idling is that, by not idling,
+ * service guarantees are preserved without minimally
+ * sacrificing throughput. In other words, both a high
+ * throughput and its desired distribution are obtained.
+ *
+ * More precisely, this preemption-based, idleless approach
+ * provides fairness in terms of IOPS, and not sectors per
+ * second. This can be seen with a simple example. Suppose
+ * that there are two queues with the same weight, but that
+ * the first queue receives requests of 8 sectors, while the
+ * second queue receives requests of 1024 sectors. In
+ * addition, suppose that each of the two queues contains at
+ * most one request at a time, which implies that each queue
+ * always remains idle after it is served. Finally, after
+ * remaining idle, each queue receives very quickly a new
+ * request. It follows that the two queues are served
+ * alternatively, preempting each other if needed. This
+ * implies that, although both queues have the same weight,
+ * the queue with large requests receives a service that is
+ * 1024/8 times as high as the service received by the other
+ * queue.
+ *
+ * On the other hand, device idling is performed, and thus
+ * pure sector-domain guarantees are provided, for the
+ * following queues, which are likely to need stronger
+ * throughput guarantees: weight-raised queues, and queues
+ * with a higher weight than other queues. When such queues
+ * are active, sub-condition (i) is false, which triggers
+ * device idling.
+ *
+ * According to the above considerations, the next variable is
+ * true (only) if sub-condition (i) holds. To compute the
+ * value of this variable, we not only use the return value of
+ * the function bfq_symmetric_scenario(), but also check
+ * whether bfqq is being weight-raised, because
+ * bfq_symmetric_scenario() does not take into account also
+ * weight-raised queues (see comments on
+ * bfq_weights_tree_add()). In particular, if bfqq is being
+ * weight-raised, it is important to idle only if there are
+ * other, non-weight-raised queues that may steal throughput
+ * to bfqq. Actually, we should be even more precise, and
+ * differentiate between interactive weight raising and
+ * soft real-time weight raising.
+ *
+ * As a side note, it is worth considering that the above
+ * device-idling countermeasures may however fail in the
+ * following unlucky scenario: if idling is (correctly)
+ * disabled in a time period during which all symmetry
+ * sub-conditions hold, and hence the device is allowed to
+ * enqueue many requests, but at some later point in time some
+ * sub-condition stops to hold, then it may become impossible
+ * to let requests be served in the desired order until all
+ * the requests already queued in the device have been served.
+ */
+ asymmetric_scenario = (bfqq->wr_coeff > 1 &&
+ bfqd->wr_busy_queues < bfqd->busy_queues) ||
+ !bfq_symmetric_scenario(bfqd);
+
+ /*
+ * Finally, there is a case where maximizing throughput is the
+ * best choice even if it may cause unfairness toward
+ * bfqq. Such a case is when bfqq became active in a burst of
+ * queue activations. Queues that became active during a large
+ * burst benefit only from throughput, as discussed in the
+ * comments on bfq_handle_burst. Thus, if bfqq became active
+ * in a burst and not idling the device maximizes throughput,
+ * then the device must no be idled, because not idling the
+ * device provides bfqq and all other queues in the burst with
+ * maximum benefit. Combining this and the above case, we can
+ * now establish when idling is actually needed to preserve
+ * service guarantees.
+ */
+ idling_needed_for_service_guarantees =
+ asymmetric_scenario && !bfq_bfqq_in_large_burst(bfqq);
+
+ /*
+ * We have now all the components we need to compute the
+ * return value of the function, which is true only if idling
+ * either boosts the throughput (without issues), or is
+ * necessary to preserve service guarantees.
+ */
+ return idling_boosts_thr_without_issues ||
+ idling_needed_for_service_guarantees;
+}
+
+/*
+ * If the in-service queue is empty but the function bfq_bfqq_may_idle
+ * returns true, then:
+ * 1) the queue must remain in service and cannot be expired, and
+ * 2) the device must be idled to wait for the possible arrival of a new
+ * request for the queue.
+ * See the comments on the function bfq_bfqq_may_idle for the reasons
+ * why performing device idling is the best choice to boost the throughput
+ * and preserve service guarantees when bfq_bfqq_may_idle itself
+ * returns true.
+ */
+static bool bfq_bfqq_must_idle(struct bfq_queue *bfqq)
+{
+ return RB_EMPTY_ROOT(&bfqq->sort_list) && bfq_bfqq_may_idle(bfqq);
+}
+
+/*
+ * Select a queue for service. If we have a current queue in service,
+ * check whether to continue servicing it, or retrieve and set a new one.
+ */
+static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
+{
+ struct bfq_queue *bfqq;
+ struct request *next_rq;
+ enum bfqq_expiration reason = BFQQE_BUDGET_TIMEOUT;
+
+ bfqq = bfqd->in_service_queue;
+ if (!bfqq)
+ goto new_queue;
+
+ bfq_log_bfqq(bfqd, bfqq, "select_queue: already in-service queue");
+
+ if (bfq_may_expire_for_budg_timeout(bfqq) &&
+ !bfq_bfqq_wait_request(bfqq) &&
+ !bfq_bfqq_must_idle(bfqq))
+ goto expire;
+
+check_queue:
+ /*
+ * This loop is rarely executed more than once. Even when it
+ * happens, it is much more convenient to re-execute this loop
+ * than to return NULL and trigger a new dispatch to get a
+ * request served.
+ */
+ next_rq = bfqq->next_rq;
+ /*
+ * If bfqq has requests queued and it has enough budget left to
+ * serve them, keep the queue, otherwise expire it.
+ */
+ if (next_rq) {
+ if (bfq_serv_to_charge(next_rq, bfqq) >
+ bfq_bfqq_budget_left(bfqq)) {
+ /*
+ * Expire the queue for budget exhaustion,
+ * which makes sure that the next budget is
+ * enough to serve the next request, even if
+ * it comes from the fifo expired path.
+ */
+ reason = BFQQE_BUDGET_EXHAUSTED;
+ goto expire;
+ } else {
+ /*
+ * The idle timer may be pending because we may
+ * not disable disk idling even when a new request
+ * arrives.
+ */
+ if (bfq_bfqq_wait_request(bfqq)) {
+ /*
+ * If we get here: 1) at least a new request
+ * has arrived but we have not disabled the
+ * timer because the request was too small,
+ * 2) then the block layer has unplugged
+ * the device, causing the dispatch to be
+ * invoked.
+ *
+ * Since the device is unplugged, now the
+ * requests are probably large enough to
+ * provide a reasonable throughput.
+ * So we disable idling.
+ */
+ bfq_clear_bfqq_wait_request(bfqq);
+ hrtimer_try_to_cancel(&bfqd->idle_slice_timer);
+ bfqg_stats_update_idle_time(bfqq_group(bfqq));
+ }
+ goto keep_queue;
+ }
+ }
+
+ /*
+ * No requests pending. However, if the in-service queue is idling
+ * for a new request, or has requests waiting for a completion and
+ * may idle after their completion, then keep it anyway.
+ */
+ if (bfq_bfqq_wait_request(bfqq) ||
+ (bfqq->dispatched != 0 && bfq_bfqq_may_idle(bfqq))) {
+ bfqq = NULL;
+ goto keep_queue;
+ }
+
+ reason = BFQQE_NO_MORE_REQUESTS;
+expire:
+ bfq_bfqq_expire(bfqd, bfqq, false, reason);
+new_queue:
+ bfqq = bfq_set_in_service_queue(bfqd);
+ if (bfqq) {
+ bfq_log_bfqq(bfqd, bfqq, "select_queue: checking new queue");
+ goto check_queue;
+ }
+keep_queue:
+ if (bfqq)
+ bfq_log_bfqq(bfqd, bfqq, "select_queue: returned this queue");
+ else
+ bfq_log(bfqd, "select_queue: no queue returned");
+
+ return bfqq;
+}
+
+static void bfq_update_wr_data(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+
+ if (bfqq->wr_coeff > 1) { /* queue is being weight-raised */
+ bfq_log_bfqq(bfqd, bfqq,
+ "raising period dur %u/%u msec, old coeff %u, w %d(%d)",
+ jiffies_to_msecs(jiffies - bfqq->last_wr_start_finish),
+ jiffies_to_msecs(bfqq->wr_cur_max_time),
+ bfqq->wr_coeff,
+ bfqq->entity.weight, bfqq->entity.orig_weight);
+
+ if (entity->prio_changed)
+ bfq_log_bfqq(bfqd, bfqq, "WARN: pending prio change");
+
+ /*
+ * If the queue was activated in a burst, or too much
+ * time has elapsed from the beginning of this
+ * weight-raising period, then end weight raising.
+ */
+ if (bfq_bfqq_in_large_burst(bfqq))
+ bfq_bfqq_end_wr(bfqq);
+ else if (time_is_before_jiffies(bfqq->last_wr_start_finish +
+ bfqq->wr_cur_max_time)) {
+ if (bfqq->wr_cur_max_time != bfqd->bfq_wr_rt_max_time ||
+ time_is_before_jiffies(bfqq->wr_start_at_switch_to_srt +
+ bfq_wr_duration(bfqd)))
+ bfq_bfqq_end_wr(bfqq);
+ else {
+ /* switch back to interactive wr */
+ bfqq->wr_coeff = bfqd->bfq_wr_coeff;
+ bfqq->wr_cur_max_time = bfq_wr_duration(bfqd);
+ bfqq->last_wr_start_finish =
+ bfqq->wr_start_at_switch_to_srt;
+ bfqq->entity.prio_changed = 1;
+ }
+ }
+ }
+ /*
+ * To improve latency (for this or other queues), immediately
+ * update weight both if it must be raised and if it must be
+ * lowered. Since, entity may be on some active tree here, and
+ * might have a pending change of its ioprio class, invoke
+ * next function with the last parameter unset (see the
+ * comments on the function).
+ */
+ if ((entity->weight > entity->orig_weight) != (bfqq->wr_coeff > 1))
+ __bfq_entity_update_weight_prio(bfq_entity_service_tree(entity),
+ entity, false);
+}
+
+/*
+ * Dispatch next request from bfqq.
+ */
+static struct request *bfq_dispatch_rq_from_bfqq(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq)
+{
+ struct request *rq = bfqq->next_rq;
+ unsigned long service_to_charge;
+
+ service_to_charge = bfq_serv_to_charge(rq, bfqq);
+
+ bfq_bfqq_served(bfqq, service_to_charge);
+
+ bfq_dispatch_remove(bfqd->queue, rq);
+
+ /*
+ * If weight raising has to terminate for bfqq, then next
+ * function causes an immediate update of bfqq's weight,
+ * without waiting for next activation. As a consequence, on
+ * expiration, bfqq will be timestamped as if has never been
+ * weight-raised during this service slot, even if it has
+ * received part or even most of the service as a
+ * weight-raised queue. This inflates bfqq's timestamps, which
+ * is beneficial, as bfqq is then more willing to leave the
+ * device immediately to possible other weight-raised queues.
+ */
+ bfq_update_wr_data(bfqd, bfqq);
+
+ /*
+ * Expire bfqq, pretending that its budget expired, if bfqq
+ * belongs to CLASS_IDLE and other queues are waiting for
+ * service.
+ */
+ if (bfqd->busy_queues > 1 && bfq_class_idle(bfqq))
+ goto expire;
+
+ return rq;
+
+expire:
+ bfq_bfqq_expire(bfqd, bfqq, false, BFQQE_BUDGET_EXHAUSTED);
+ return rq;
+}
+
+static bool bfq_has_work(struct blk_mq_hw_ctx *hctx)
+{
+ struct bfq_data *bfqd = hctx->queue->elevator->elevator_data;
+
+ /*
+ * Avoiding lock: a race on bfqd->busy_queues should cause at
+ * most a call to dispatch for nothing
+ */
+ return !list_empty_careful(&bfqd->dispatch) ||
+ bfqd->busy_queues > 0;
+}
+
+static struct request *__bfq_dispatch_request(struct blk_mq_hw_ctx *hctx)
+{
+ struct bfq_data *bfqd = hctx->queue->elevator->elevator_data;
+ struct request *rq = NULL;
+ struct bfq_queue *bfqq = NULL;
+
+ if (!list_empty(&bfqd->dispatch)) {
+ rq = list_first_entry(&bfqd->dispatch, struct request,
+ queuelist);
+ list_del_init(&rq->queuelist);
+
+ bfqq = RQ_BFQQ(rq);
+
+ if (bfqq) {
+ /*
+ * Increment counters here, because this
+ * dispatch does not follow the standard
+ * dispatch flow (where counters are
+ * incremented)
+ */
+ bfqq->dispatched++;
+
+ goto inc_in_driver_start_rq;
+ }
+
+ /*
+ * We exploit the put_rq_private hook to decrement
+ * rq_in_driver, but put_rq_private will not be
+ * invoked on this request. So, to avoid unbalance,
+ * just start this request, without incrementing
+ * rq_in_driver. As a negative consequence,
+ * rq_in_driver is deceptively lower than it should be
+ * while this request is in service. This may cause
+ * bfq_schedule_dispatch to be invoked uselessly.
+ *
+ * As for implementing an exact solution, the
+ * put_request hook, if defined, is probably invoked
+ * also on this request. So, by exploiting this hook,
+ * we could 1) increment rq_in_driver here, and 2)
+ * decrement it in put_request. Such a solution would
+ * let the value of the counter be always accurate,
+ * but it would entail using an extra interface
+ * function. This cost seems higher than the benefit,
+ * being the frequency of non-elevator-private
+ * requests very low.
+ */
+ goto start_rq;
+ }
+
+ bfq_log(bfqd, "dispatch requests: %d busy queues", bfqd->busy_queues);
+
+ if (bfqd->busy_queues == 0)
+ goto exit;
+
+ /*
+ * Force device to serve one request at a time if
+ * strict_guarantees is true. Forcing this service scheme is
+ * currently the ONLY way to guarantee that the request
+ * service order enforced by the scheduler is respected by a
+ * queueing device. Otherwise the device is free even to make
+ * some unlucky request wait for as long as the device
+ * wishes.
+ *
+ * Of course, serving one request at at time may cause loss of
+ * throughput.
+ */
+ if (bfqd->strict_guarantees && bfqd->rq_in_driver > 0)
+ goto exit;
+
+ bfqq = bfq_select_queue(bfqd);
+ if (!bfqq)
+ goto exit;
+
+ rq = bfq_dispatch_rq_from_bfqq(bfqd, bfqq);
+
+ if (rq) {
+inc_in_driver_start_rq:
+ bfqd->rq_in_driver++;
+start_rq:
+ rq->rq_flags |= RQF_STARTED;
+ }
+exit:
+ return rq;
+}
+
+static struct request *bfq_dispatch_request(struct blk_mq_hw_ctx *hctx)
+{
+ struct bfq_data *bfqd = hctx->queue->elevator->elevator_data;
+ struct request *rq;
+
+ spin_lock_irq(&bfqd->lock);
+
+ rq = __bfq_dispatch_request(hctx);
+ spin_unlock_irq(&bfqd->lock);
+
+ return rq;
+}
+
+/*
+ * Task holds one reference to the queue, dropped when task exits. Each rq
+ * in-flight on this queue also holds a reference, dropped when rq is freed.
+ *
+ * Scheduler lock must be held here. Recall not to use bfqq after calling
+ * this function on it.
+ */
+void bfq_put_queue(struct bfq_queue *bfqq)
+{
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ struct bfq_group *bfqg = bfqq_group(bfqq);
+#endif
+
+ if (bfqq->bfqd)
+ bfq_log_bfqq(bfqq->bfqd, bfqq, "put_queue: %p %d",
+ bfqq, bfqq->ref);
+
+ bfqq->ref--;
+ if (bfqq->ref)
+ return;
+
+ if (bfq_bfqq_sync(bfqq))
+ /*
+ * The fact that this queue is being destroyed does not
+ * invalidate the fact that this queue may have been
+ * activated during the current burst. As a consequence,
+ * although the queue does not exist anymore, and hence
+ * needs to be removed from the burst list if there,
+ * the burst size has not to be decremented.
+ */
+ hlist_del_init(&bfqq->burst_list_node);
+
+ kmem_cache_free(bfq_pool, bfqq);
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ bfqg_and_blkg_put(bfqg);
+#endif
+}
+
+static void bfq_put_cooperator(struct bfq_queue *bfqq)
+{
+ struct bfq_queue *__bfqq, *next;
+
+ /*
+ * If this queue was scheduled to merge with another queue, be
+ * sure to drop the reference taken on that queue (and others in
+ * the merge chain). See bfq_setup_merge and bfq_merge_bfqqs.
+ */
+ __bfqq = bfqq->new_bfqq;
+ while (__bfqq) {
+ if (__bfqq == bfqq)
+ break;
+ next = __bfqq->new_bfqq;
+ bfq_put_queue(__bfqq);
+ __bfqq = next;
+ }
+}
+
+static void bfq_exit_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ if (bfqq == bfqd->in_service_queue) {
+ __bfq_bfqq_expire(bfqd, bfqq);
+ bfq_schedule_dispatch(bfqd);
+ }
+
+ bfq_log_bfqq(bfqd, bfqq, "exit_bfqq: %p, %d", bfqq, bfqq->ref);
+
+ bfq_put_cooperator(bfqq);
+
+ bfq_put_queue(bfqq); /* release process reference */
+}
+
+static void bfq_exit_icq_bfqq(struct bfq_io_cq *bic, bool is_sync)
+{
+ struct bfq_queue *bfqq = bic_to_bfqq(bic, is_sync);
+ struct bfq_data *bfqd;
+
+ if (bfqq)
+ bfqd = bfqq->bfqd; /* NULL if scheduler already exited */
+
+ if (bfqq && bfqd) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&bfqd->lock, flags);
+ bfqq->bic = NULL;
+ bfq_exit_bfqq(bfqd, bfqq);
+ bic_set_bfqq(bic, NULL, is_sync);
+ spin_unlock_irqrestore(&bfqd->lock, flags);
+ }
+}
+
+static void bfq_exit_icq(struct io_cq *icq)
+{
+ struct bfq_io_cq *bic = icq_to_bic(icq);
+
+ bfq_exit_icq_bfqq(bic, true);
+ bfq_exit_icq_bfqq(bic, false);
+}
+
+/*
+ * Update the entity prio values; note that the new values will not
+ * be used until the next (re)activation.
+ */
+static void
+bfq_set_next_ioprio_data(struct bfq_queue *bfqq, struct bfq_io_cq *bic)
+{
+ struct task_struct *tsk = current;
+ int ioprio_class;
+ struct bfq_data *bfqd = bfqq->bfqd;
+
+ if (!bfqd)
+ return;
+
+ ioprio_class = IOPRIO_PRIO_CLASS(bic->ioprio);
+ switch (ioprio_class) {
+ default:
+ dev_err(bfqq->bfqd->queue->backing_dev_info->dev,
+ "bfq: bad prio class %d\n", ioprio_class);
+ /* fall through */
+ case IOPRIO_CLASS_NONE:
+ /*
+ * No prio set, inherit CPU scheduling settings.
+ */
+ bfqq->new_ioprio = task_nice_ioprio(tsk);
+ bfqq->new_ioprio_class = task_nice_ioclass(tsk);
+ break;
+ case IOPRIO_CLASS_RT:
+ bfqq->new_ioprio = IOPRIO_PRIO_DATA(bic->ioprio);
+ bfqq->new_ioprio_class = IOPRIO_CLASS_RT;
+ break;
+ case IOPRIO_CLASS_BE:
+ bfqq->new_ioprio = IOPRIO_PRIO_DATA(bic->ioprio);
+ bfqq->new_ioprio_class = IOPRIO_CLASS_BE;
+ break;
+ case IOPRIO_CLASS_IDLE:
+ bfqq->new_ioprio_class = IOPRIO_CLASS_IDLE;
+ bfqq->new_ioprio = 7;
+ break;
+ }
+
+ if (bfqq->new_ioprio >= IOPRIO_BE_NR) {
+ pr_crit("bfq_set_next_ioprio_data: new_ioprio %d\n",
+ bfqq->new_ioprio);
+ bfqq->new_ioprio = IOPRIO_BE_NR;
+ }
+
+ bfqq->entity.new_weight = bfq_ioprio_to_weight(bfqq->new_ioprio);
+ bfqq->entity.prio_changed = 1;
+}
+
+static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd,
+ struct bio *bio, bool is_sync,
+ struct bfq_io_cq *bic);
+
+static void bfq_check_ioprio_change(struct bfq_io_cq *bic, struct bio *bio)
+{
+ struct bfq_data *bfqd = bic_to_bfqd(bic);
+ struct bfq_queue *bfqq;
+ int ioprio = bic->icq.ioc->ioprio;
+
+ /*
+ * This condition may trigger on a newly created bic, be sure to
+ * drop the lock before returning.
+ */
+ if (unlikely(!bfqd) || likely(bic->ioprio == ioprio))
+ return;
+
+ bic->ioprio = ioprio;
+
+ bfqq = bic_to_bfqq(bic, false);
+ if (bfqq) {
+ /* release process reference on this queue */
+ bfq_put_queue(bfqq);
+ bfqq = bfq_get_queue(bfqd, bio, BLK_RW_ASYNC, bic);
+ bic_set_bfqq(bic, bfqq, false);
+ }
+
+ bfqq = bic_to_bfqq(bic, true);
+ if (bfqq)
+ bfq_set_next_ioprio_data(bfqq, bic);
+}
+
+static void bfq_init_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ struct bfq_io_cq *bic, pid_t pid, int is_sync)
+{
+ RB_CLEAR_NODE(&bfqq->entity.rb_node);
+ INIT_LIST_HEAD(&bfqq->fifo);
+ INIT_HLIST_NODE(&bfqq->burst_list_node);
+
+ bfqq->ref = 0;
+ bfqq->bfqd = bfqd;
+
+ if (bic)
+ bfq_set_next_ioprio_data(bfqq, bic);
+
+ if (is_sync) {
+ /*
+ * No need to mark as has_short_ttime if in
+ * idle_class, because no device idling is performed
+ * for queues in idle class
+ */
+ if (!bfq_class_idle(bfqq))
+ /* tentatively mark as has_short_ttime */
+ bfq_mark_bfqq_has_short_ttime(bfqq);
+ bfq_mark_bfqq_sync(bfqq);
+ bfq_mark_bfqq_just_created(bfqq);
+ } else
+ bfq_clear_bfqq_sync(bfqq);
+
+ /* set end request to minus infinity from now */
+ bfqq->ttime.last_end_request = ktime_get_ns() + 1;
+
+ bfq_mark_bfqq_IO_bound(bfqq);
+
+ bfqq->pid = pid;
+
+ /* Tentative initial value to trade off between thr and lat */
+ bfqq->max_budget = (2 * bfq_max_budget(bfqd)) / 3;
+ bfqq->budget_timeout = bfq_smallest_from_now();
+
+ bfqq->wr_coeff = 1;
+ bfqq->last_wr_start_finish = jiffies;
+ bfqq->wr_start_at_switch_to_srt = bfq_smallest_from_now();
+ bfqq->split_time = bfq_smallest_from_now();
+
+ /*
+ * Set to the value for which bfqq will not be deemed as
+ * soft rt when it becomes backlogged.
+ */
+ bfqq->soft_rt_next_start = bfq_greatest_from_now();
+
+ /* first request is almost certainly seeky */
+ bfqq->seek_history = 1;
+}
+
+static struct bfq_queue **bfq_async_queue_prio(struct bfq_data *bfqd,
+ struct bfq_group *bfqg,
+ int ioprio_class, int ioprio)
+{
+ switch (ioprio_class) {
+ case IOPRIO_CLASS_RT:
+ return &bfqg->async_bfqq[0][ioprio];
+ case IOPRIO_CLASS_NONE:
+ ioprio = IOPRIO_NORM;
+ /* fall through */
+ case IOPRIO_CLASS_BE:
+ return &bfqg->async_bfqq[1][ioprio];
+ case IOPRIO_CLASS_IDLE:
+ return &bfqg->async_idle_bfqq;
+ default:
+ return NULL;
+ }
+}
+
+static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd,
+ struct bio *bio, bool is_sync,
+ struct bfq_io_cq *bic)
+{
+ const int ioprio = IOPRIO_PRIO_DATA(bic->ioprio);
+ const int ioprio_class = IOPRIO_PRIO_CLASS(bic->ioprio);
+ struct bfq_queue **async_bfqq = NULL;
+ struct bfq_queue *bfqq;
+ struct bfq_group *bfqg;
+
+ rcu_read_lock();
+
+ bfqg = bfq_find_set_group(bfqd, bio_blkcg(bio));
+ if (!bfqg) {
+ bfqq = &bfqd->oom_bfqq;
+ goto out;
+ }
+
+ if (!is_sync) {
+ async_bfqq = bfq_async_queue_prio(bfqd, bfqg, ioprio_class,
+ ioprio);
+ bfqq = *async_bfqq;
+ if (bfqq)
+ goto out;
+ }
+
+ bfqq = kmem_cache_alloc_node(bfq_pool,
+ GFP_NOWAIT | __GFP_ZERO | __GFP_NOWARN,
+ bfqd->queue->node);
+
+ if (bfqq) {
+ bfq_init_bfqq(bfqd, bfqq, bic, current->pid,
+ is_sync);
+ bfq_init_entity(&bfqq->entity, bfqg);
+ bfq_log_bfqq(bfqd, bfqq, "allocated");
+ } else {
+ bfqq = &bfqd->oom_bfqq;
+ bfq_log_bfqq(bfqd, bfqq, "using oom bfqq");
+ goto out;
+ }
+
+ /*
+ * Pin the queue now that it's allocated, scheduler exit will
+ * prune it.
+ */
+ if (async_bfqq) {
+ bfqq->ref++; /*
+ * Extra group reference, w.r.t. sync
+ * queue. This extra reference is removed
+ * only if bfqq->bfqg disappears, to
+ * guarantee that this queue is not freed
+ * until its group goes away.
+ */
+ bfq_log_bfqq(bfqd, bfqq, "get_queue, bfqq not in async: %p, %d",
+ bfqq, bfqq->ref);
+ *async_bfqq = bfqq;
+ }
+
+out:
+ bfqq->ref++; /* get a process reference to this queue */
+ bfq_log_bfqq(bfqd, bfqq, "get_queue, at end: %p, %d", bfqq, bfqq->ref);
+ rcu_read_unlock();
+ return bfqq;
+}
+
+static void bfq_update_io_thinktime(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq)
+{
+ struct bfq_ttime *ttime = &bfqq->ttime;
+ u64 elapsed = ktime_get_ns() - bfqq->ttime.last_end_request;
+
+ elapsed = min_t(u64, elapsed, 2ULL * bfqd->bfq_slice_idle);
+
+ ttime->ttime_samples = (7*bfqq->ttime.ttime_samples + 256) / 8;
+ ttime->ttime_total = div_u64(7*ttime->ttime_total + 256*elapsed, 8);
+ ttime->ttime_mean = div64_ul(ttime->ttime_total + 128,
+ ttime->ttime_samples);
+}
+
+static void
+bfq_update_io_seektime(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ struct request *rq)
+{
+ bfqq->seek_history <<= 1;
+ bfqq->seek_history |=
+ get_sdist(bfqq->last_request_pos, rq) > BFQQ_SEEK_THR &&
+ (!blk_queue_nonrot(bfqd->queue) ||
+ blk_rq_sectors(rq) < BFQQ_SECT_THR_NONROT);
+}
+
+static void bfq_update_has_short_ttime(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq,
+ struct bfq_io_cq *bic)
+{
+ bool has_short_ttime = true;
+
+ /*
+ * No need to update has_short_ttime if bfqq is async or in
+ * idle io prio class, or if bfq_slice_idle is zero, because
+ * no device idling is performed for bfqq in this case.
+ */
+ if (!bfq_bfqq_sync(bfqq) || bfq_class_idle(bfqq) ||
+ bfqd->bfq_slice_idle == 0)
+ return;
+
+ /* Idle window just restored, statistics are meaningless. */
+ if (time_is_after_eq_jiffies(bfqq->split_time +
+ bfqd->bfq_wr_min_idle_time))
+ return;
+
+ /* Think time is infinite if no process is linked to
+ * bfqq. Otherwise check average think time to
+ * decide whether to mark as has_short_ttime
+ */
+ if (atomic_read(&bic->icq.ioc->active_ref) == 0 ||
+ (bfq_sample_valid(bfqq->ttime.ttime_samples) &&
+ bfqq->ttime.ttime_mean > bfqd->bfq_slice_idle))
+ has_short_ttime = false;
+
+ bfq_log_bfqq(bfqd, bfqq, "update_has_short_ttime: has_short_ttime %d",
+ has_short_ttime);
+
+ if (has_short_ttime)
+ bfq_mark_bfqq_has_short_ttime(bfqq);
+ else
+ bfq_clear_bfqq_has_short_ttime(bfqq);
+}
+
+/*
+ * Called when a new fs request (rq) is added to bfqq. Check if there's
+ * something we should do about it.
+ */
+static void bfq_rq_enqueued(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ struct request *rq)
+{
+ struct bfq_io_cq *bic = RQ_BIC(rq);
+
+ if (rq->cmd_flags & REQ_META)
+ bfqq->meta_pending++;
+
+ bfq_update_io_thinktime(bfqd, bfqq);
+ bfq_update_has_short_ttime(bfqd, bfqq, bic);
+ bfq_update_io_seektime(bfqd, bfqq, rq);
+
+ bfq_log_bfqq(bfqd, bfqq,
+ "rq_enqueued: has_short_ttime=%d (seeky %d)",
+ bfq_bfqq_has_short_ttime(bfqq), BFQQ_SEEKY(bfqq));
+
+ bfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq);
+
+ if (bfqq == bfqd->in_service_queue && bfq_bfqq_wait_request(bfqq)) {
+ bool small_req = bfqq->queued[rq_is_sync(rq)] == 1 &&
+ blk_rq_sectors(rq) < 32;
+ bool budget_timeout = bfq_bfqq_budget_timeout(bfqq);
+
+ /*
+ * There is just this request queued: if the request
+ * is small and the queue is not to be expired, then
+ * just exit.
+ *
+ * In this way, if the device is being idled to wait
+ * for a new request from the in-service queue, we
+ * avoid unplugging the device and committing the
+ * device to serve just a small request. On the
+ * contrary, we wait for the block layer to decide
+ * when to unplug the device: hopefully, new requests
+ * will be merged to this one quickly, then the device
+ * will be unplugged and larger requests will be
+ * dispatched.
+ */
+ if (small_req && !budget_timeout)
+ return;
+
+ /*
+ * A large enough request arrived, or the queue is to
+ * be expired: in both cases disk idling is to be
+ * stopped, so clear wait_request flag and reset
+ * timer.
+ */
+ bfq_clear_bfqq_wait_request(bfqq);
+ hrtimer_try_to_cancel(&bfqd->idle_slice_timer);
+ bfqg_stats_update_idle_time(bfqq_group(bfqq));
+
+ /*
+ * The queue is not empty, because a new request just
+ * arrived. Hence we can safely expire the queue, in
+ * case of budget timeout, without risking that the
+ * timestamps of the queue are not updated correctly.
+ * See [1] for more details.
+ */
+ if (budget_timeout)
+ bfq_bfqq_expire(bfqd, bfqq, false,
+ BFQQE_BUDGET_TIMEOUT);
+ }
+}
+
+static void __bfq_insert_request(struct bfq_data *bfqd, struct request *rq)
+{
+ struct bfq_queue *bfqq = RQ_BFQQ(rq),
+ *new_bfqq = bfq_setup_cooperator(bfqd, bfqq, rq, true);
+
+ if (new_bfqq) {
+ if (bic_to_bfqq(RQ_BIC(rq), 1) != bfqq)
+ new_bfqq = bic_to_bfqq(RQ_BIC(rq), 1);
+ /*
+ * Release the request's reference to the old bfqq
+ * and make sure one is taken to the shared queue.
+ */
+ new_bfqq->allocated++;
+ bfqq->allocated--;
+ new_bfqq->ref++;
+ bfq_clear_bfqq_just_created(bfqq);
+ /*
+ * If the bic associated with the process
+ * issuing this request still points to bfqq
+ * (and thus has not been already redirected
+ * to new_bfqq or even some other bfq_queue),
+ * then complete the merge and redirect it to
+ * new_bfqq.
+ */
+ if (bic_to_bfqq(RQ_BIC(rq), 1) == bfqq)
+ bfq_merge_bfqqs(bfqd, RQ_BIC(rq),
+ bfqq, new_bfqq);
+ /*
+ * rq is about to be enqueued into new_bfqq,
+ * release rq reference on bfqq
+ */
+ bfq_put_queue(bfqq);
+ rq->elv.priv[1] = new_bfqq;
+ bfqq = new_bfqq;
+ }
+
+ bfq_add_request(rq);
+
+ rq->fifo_time = ktime_get_ns() + bfqd->bfq_fifo_expire[rq_is_sync(rq)];
+ list_add_tail(&rq->queuelist, &bfqq->fifo);
+
+ bfq_rq_enqueued(bfqd, bfqq, rq);
+}
+
+static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
+ bool at_head)
+{
+ struct request_queue *q = hctx->queue;
+ struct bfq_data *bfqd = q->elevator->elevator_data;
+
+ spin_lock_irq(&bfqd->lock);
+ if (blk_mq_sched_try_insert_merge(q, rq)) {
+ spin_unlock_irq(&bfqd->lock);
+ return;
+ }
+
+ spin_unlock_irq(&bfqd->lock);
+
+ blk_mq_sched_request_inserted(rq);
+
+ spin_lock_irq(&bfqd->lock);
+ if (at_head || blk_rq_is_passthrough(rq)) {
+ if (at_head)
+ list_add(&rq->queuelist, &bfqd->dispatch);
+ else
+ list_add_tail(&rq->queuelist, &bfqd->dispatch);
+ } else {
+ __bfq_insert_request(bfqd, rq);
+
+ if (rq_mergeable(rq)) {
+ elv_rqhash_add(q, rq);
+ if (!q->last_merge)
+ q->last_merge = rq;
+ }
+ }
+
+ spin_unlock_irq(&bfqd->lock);
+}
+
+static void bfq_insert_requests(struct blk_mq_hw_ctx *hctx,
+ struct list_head *list, bool at_head)
+{
+ while (!list_empty(list)) {
+ struct request *rq;
+
+ rq = list_first_entry(list, struct request, queuelist);
+ list_del_init(&rq->queuelist);
+ bfq_insert_request(hctx, rq, at_head);
+ }
+}
+
+static void bfq_update_hw_tag(struct bfq_data *bfqd)
+{
+ bfqd->max_rq_in_driver = max_t(int, bfqd->max_rq_in_driver,
+ bfqd->rq_in_driver);
+
+ if (bfqd->hw_tag == 1)
+ return;
+
+ /*
+ * This sample is valid if the number of outstanding requests
+ * is large enough to allow a queueing behavior. Note that the
+ * sum is not exact, as it's not taking into account deactivated
+ * requests.
+ */
+ if (bfqd->rq_in_driver + bfqd->queued < BFQ_HW_QUEUE_THRESHOLD)
+ return;
+
+ if (bfqd->hw_tag_samples++ < BFQ_HW_QUEUE_SAMPLES)
+ return;
+
+ bfqd->hw_tag = bfqd->max_rq_in_driver > BFQ_HW_QUEUE_THRESHOLD;
+ bfqd->max_rq_in_driver = 0;
+ bfqd->hw_tag_samples = 0;
+}
+
+static void bfq_completed_request(struct bfq_queue *bfqq, struct bfq_data *bfqd)
+{
+ u64 now_ns;
+ u32 delta_us;
+
+ bfq_update_hw_tag(bfqd);
+
+ bfqd->rq_in_driver--;
+ bfqq->dispatched--;
+
+ if (!bfqq->dispatched && !bfq_bfqq_busy(bfqq)) {
+ /*
+ * Set budget_timeout (which we overload to store the
+ * time at which the queue remains with no backlog and
+ * no outstanding request; used by the weight-raising
+ * mechanism).
+ */
+ bfqq->budget_timeout = jiffies;
+
+ bfq_weights_tree_remove(bfqd, &bfqq->entity,
+ &bfqd->queue_weights_tree);
+ }
+
+ now_ns = ktime_get_ns();
+
+ bfqq->ttime.last_end_request = now_ns;
+
+ /*
+ * Using us instead of ns, to get a reasonable precision in
+ * computing rate in next check.
+ */
+ delta_us = div_u64(now_ns - bfqd->last_completion, NSEC_PER_USEC);
+
+ /*
+ * If the request took rather long to complete, and, according
+ * to the maximum request size recorded, this completion latency
+ * implies that the request was certainly served at a very low
+ * rate (less than 1M sectors/sec), then the whole observation
+ * interval that lasts up to this time instant cannot be a
+ * valid time interval for computing a new peak rate. Invoke
+ * bfq_update_rate_reset to have the following three steps
+ * taken:
+ * - close the observation interval at the last (previous)
+ * request dispatch or completion
+ * - compute rate, if possible, for that observation interval
+ * - reset to zero samples, which will trigger a proper
+ * re-initialization of the observation interval on next
+ * dispatch
+ */
+ if (delta_us > BFQ_MIN_TT/NSEC_PER_USEC &&
+ (bfqd->last_rq_max_size<<BFQ_RATE_SHIFT)/delta_us <
+ 1UL<<(BFQ_RATE_SHIFT - 10))
+ bfq_update_rate_reset(bfqd, NULL);
+ bfqd->last_completion = now_ns;
+
+ /*
+ * If we are waiting to discover whether the request pattern
+ * of the task associated with the queue is actually
+ * isochronous, and both requisites for this condition to hold
+ * are now satisfied, then compute soft_rt_next_start (see the
+ * comments on the function bfq_bfqq_softrt_next_start()). We
+ * schedule this delayed check when bfqq expires, if it still
+ * has in-flight requests.
+ */
+ if (bfq_bfqq_softrt_update(bfqq) && bfqq->dispatched == 0 &&
+ RB_EMPTY_ROOT(&bfqq->sort_list))
+ bfqq->soft_rt_next_start =
+ bfq_bfqq_softrt_next_start(bfqd, bfqq);
+
+ /*
+ * If this is the in-service queue, check if it needs to be expired,
+ * or if we want to idle in case it has no pending requests.
+ */
+ if (bfqd->in_service_queue == bfqq) {
+ if (bfqq->dispatched == 0 && bfq_bfqq_must_idle(bfqq)) {
+ bfq_arm_slice_timer(bfqd);
+ return;
+ } else if (bfq_may_expire_for_budg_timeout(bfqq))
+ bfq_bfqq_expire(bfqd, bfqq, false,
+ BFQQE_BUDGET_TIMEOUT);
+ else if (RB_EMPTY_ROOT(&bfqq->sort_list) &&
+ (bfqq->dispatched == 0 ||
+ !bfq_bfqq_may_idle(bfqq)))
+ bfq_bfqq_expire(bfqd, bfqq, false,
+ BFQQE_NO_MORE_REQUESTS);
+ }
+
+ if (!bfqd->rq_in_driver)
+ bfq_schedule_dispatch(bfqd);
+}
+
+static void bfq_put_rq_priv_body(struct bfq_queue *bfqq)
+{
+ bfqq->allocated--;
+
+ bfq_put_queue(bfqq);
+}
+
+static void bfq_finish_request(struct request *rq)
+{
+ struct bfq_queue *bfqq;
+ struct bfq_data *bfqd;
+
+ if (!rq->elv.icq)
+ return;
+
+ bfqq = RQ_BFQQ(rq);
+ bfqd = bfqq->bfqd;
+
+ if (rq->rq_flags & RQF_STARTED)
+ bfqg_stats_update_completion(bfqq_group(bfqq),
+ rq_start_time_ns(rq),
+ rq_io_start_time_ns(rq),
+ rq->cmd_flags);
+
+ if (likely(rq->rq_flags & RQF_STARTED)) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&bfqd->lock, flags);
+
+ bfq_completed_request(bfqq, bfqd);
+ bfq_put_rq_priv_body(bfqq);
+
+ spin_unlock_irqrestore(&bfqd->lock, flags);
+ } else {
+ /*
+ * Request rq may be still/already in the scheduler,
+ * in which case we need to remove it. And we cannot
+ * defer such a check and removal, to avoid
+ * inconsistencies in the time interval from the end
+ * of this function to the start of the deferred work.
+ * This situation seems to occur only in process
+ * context, as a consequence of a merge. In the
+ * current version of the code, this implies that the
+ * lock is held.
+ */
+
+ if (!RB_EMPTY_NODE(&rq->rb_node))
+ bfq_remove_request(rq->q, rq);
+ bfq_put_rq_priv_body(bfqq);
+ }
+
+ rq->elv.priv[0] = NULL;
+ rq->elv.priv[1] = NULL;
+}
+
+/*
+ * Returns NULL if a new bfqq should be allocated, or the old bfqq if this
+ * was the last process referring to that bfqq.
+ */
+static struct bfq_queue *
+bfq_split_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq)
+{
+ bfq_log_bfqq(bfqq->bfqd, bfqq, "splitting queue");
+
+ if (bfqq_process_refs(bfqq) == 1) {
+ bfqq->pid = current->pid;
+ bfq_clear_bfqq_coop(bfqq);
+ bfq_clear_bfqq_split_coop(bfqq);
+ return bfqq;
+ }
+
+ bic_set_bfqq(bic, NULL, 1);
+
+ bfq_put_cooperator(bfqq);
+
+ bfq_put_queue(bfqq);
+ return NULL;
+}
+
+static struct bfq_queue *bfq_get_bfqq_handle_split(struct bfq_data *bfqd,
+ struct bfq_io_cq *bic,
+ struct bio *bio,
+ bool split, bool is_sync,
+ bool *new_queue)
+{
+ struct bfq_queue *bfqq = bic_to_bfqq(bic, is_sync);
+
+ if (likely(bfqq && bfqq != &bfqd->oom_bfqq))
+ return bfqq;
+
+ if (new_queue)
+ *new_queue = true;
+
+ if (bfqq)
+ bfq_put_queue(bfqq);
+ bfqq = bfq_get_queue(bfqd, bio, is_sync, bic);
+
+ bic_set_bfqq(bic, bfqq, is_sync);
+ if (split && is_sync) {
+ if ((bic->was_in_burst_list && bfqd->large_burst) ||
+ bic->saved_in_large_burst)
+ bfq_mark_bfqq_in_large_burst(bfqq);
+ else {
+ bfq_clear_bfqq_in_large_burst(bfqq);
+ if (bic->was_in_burst_list)
+ hlist_add_head(&bfqq->burst_list_node,
+ &bfqd->burst_list);
+ }
+ bfqq->split_time = jiffies;
+ }
+
+ return bfqq;
+}
+
+/*
+ * Allocate bfq data structures associated with this request.
+ */
+static void bfq_prepare_request(struct request *rq, struct bio *bio)
+{
+ struct request_queue *q = rq->q;
+ struct bfq_data *bfqd = q->elevator->elevator_data;
+ struct bfq_io_cq *bic;
+ const int is_sync = rq_is_sync(rq);
+ struct bfq_queue *bfqq;
+ bool new_queue = false;
+ bool bfqq_already_existing = false, split = false;
+
+ /*
+ * Even if we don't have an icq attached, we should still clear
+ * the scheduler pointers, as they might point to previously
+ * allocated bic/bfqq structs.
+ */
+ if (!rq->elv.icq) {
+ rq->elv.priv[0] = rq->elv.priv[1] = NULL;
+ return;
+ }
+
+ bic = icq_to_bic(rq->elv.icq);
+
+ spin_lock_irq(&bfqd->lock);
+
+ bfq_check_ioprio_change(bic, bio);
+
+ bfq_bic_update_cgroup(bic, bio);
+
+ bfqq = bfq_get_bfqq_handle_split(bfqd, bic, bio, false, is_sync,
+ &new_queue);
+
+ if (likely(!new_queue)) {
+ /* If the queue was seeky for too long, break it apart. */
+ if (bfq_bfqq_coop(bfqq) && bfq_bfqq_split_coop(bfqq)) {
+ bfq_log_bfqq(bfqd, bfqq, "breaking apart bfqq");
+
+ /* Update bic before losing reference to bfqq */
+ if (bfq_bfqq_in_large_burst(bfqq))
+ bic->saved_in_large_burst = true;
+
+ bfqq = bfq_split_bfqq(bic, bfqq);
+ split = true;
+
+ if (!bfqq)
+ bfqq = bfq_get_bfqq_handle_split(bfqd, bic, bio,
+ true, is_sync,
+ NULL);
+ else
+ bfqq_already_existing = true;
+ }
+ }
+
+ bfqq->allocated++;
+ bfqq->ref++;
+ bfq_log_bfqq(bfqd, bfqq, "get_request %p: bfqq %p, %d",
+ rq, bfqq, bfqq->ref);
+
+ rq->elv.priv[0] = bic;
+ rq->elv.priv[1] = bfqq;
+
+ /*
+ * If a bfq_queue has only one process reference, it is owned
+ * by only this bic: we can then set bfqq->bic = bic. in
+ * addition, if the queue has also just been split, we have to
+ * resume its state.
+ */
+ if (likely(bfqq != &bfqd->oom_bfqq) && bfqq_process_refs(bfqq) == 1) {
+ bfqq->bic = bic;
+ if (split) {
+ /*
+ * The queue has just been split from a shared
+ * queue: restore the idle window and the
+ * possible weight raising period.
+ */
+ bfq_bfqq_resume_state(bfqq, bfqd, bic,
+ bfqq_already_existing);
+ }
+ }
+
+ if (unlikely(bfq_bfqq_just_created(bfqq)))
+ bfq_handle_burst(bfqd, bfqq);
+
+ spin_unlock_irq(&bfqd->lock);
+}
+
+static void
+bfq_idle_slice_timer_body(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ enum bfqq_expiration reason;
+ unsigned long flags;
+
+ spin_lock_irqsave(&bfqd->lock, flags);
+
+ /*
+ * Considering that bfqq may be in race, we should firstly check
+ * whether bfqq is in service before doing something on it. If
+ * the bfqq in race is not in service, it has already been expired
+ * through __bfq_bfqq_expire func and its wait_request flags has
+ * been cleared in __bfq_bfqd_reset_in_service func.
+ */
+ if (bfqq != bfqd->in_service_queue) {
+ spin_unlock_irqrestore(&bfqd->lock, flags);
+ return;
+ }
+
+ bfq_clear_bfqq_wait_request(bfqq);
+
+ if (bfq_bfqq_budget_timeout(bfqq))
+ /*
+ * Also here the queue can be safely expired
+ * for budget timeout without wasting
+ * guarantees
+ */
+ reason = BFQQE_BUDGET_TIMEOUT;
+ else if (bfqq->queued[0] == 0 && bfqq->queued[1] == 0)
+ /*
+ * The queue may not be empty upon timer expiration,
+ * because we may not disable the timer when the
+ * first request of the in-service queue arrives
+ * during disk idling.
+ */
+ reason = BFQQE_TOO_IDLE;
+ else
+ goto schedule_dispatch;
+
+ bfq_bfqq_expire(bfqd, bfqq, true, reason);
+
+schedule_dispatch:
+ spin_unlock_irqrestore(&bfqd->lock, flags);
+ bfq_schedule_dispatch(bfqd);
+}
+
+/*
+ * Handler of the expiration of the timer running if the in-service queue
+ * is idling inside its time slice.
+ */
+static enum hrtimer_restart bfq_idle_slice_timer(struct hrtimer *timer)
+{
+ struct bfq_data *bfqd = container_of(timer, struct bfq_data,
+ idle_slice_timer);
+ struct bfq_queue *bfqq = bfqd->in_service_queue;
+
+ /*
+ * Theoretical race here: the in-service queue can be NULL or
+ * different from the queue that was idling if a new request
+ * arrives for the current queue and there is a full dispatch
+ * cycle that changes the in-service queue. This can hardly
+ * happen, but in the worst case we just expire a queue too
+ * early.
+ */
+ if (bfqq)
+ bfq_idle_slice_timer_body(bfqd, bfqq);
+
+ return HRTIMER_NORESTART;
+}
+
+static void __bfq_put_async_bfqq(struct bfq_data *bfqd,
+ struct bfq_queue **bfqq_ptr)
+{
+ struct bfq_queue *bfqq = *bfqq_ptr;
+
+ bfq_log(bfqd, "put_async_bfqq: %p", bfqq);
+ if (bfqq) {
+ bfq_bfqq_move(bfqd, bfqq, bfqd->root_group);
+
+ bfq_log_bfqq(bfqd, bfqq, "put_async_bfqq: putting %p, %d",
+ bfqq, bfqq->ref);
+ bfq_put_queue(bfqq);
+ *bfqq_ptr = NULL;
+ }
+}
+
+/*
+ * Release all the bfqg references to its async queues. If we are
+ * deallocating the group these queues may still contain requests, so
+ * we reparent them to the root cgroup (i.e., the only one that will
+ * exist for sure until all the requests on a device are gone).
+ */
+void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg)
+{
+ int i, j;
+
+ for (i = 0; i < 2; i++)
+ for (j = 0; j < IOPRIO_BE_NR; j++)
+ __bfq_put_async_bfqq(bfqd, &bfqg->async_bfqq[i][j]);
+
+ __bfq_put_async_bfqq(bfqd, &bfqg->async_idle_bfqq);
+}
+
+static void bfq_exit_queue(struct elevator_queue *e)
+{
+ struct bfq_data *bfqd = e->elevator_data;
+ struct bfq_queue *bfqq, *n;
+
+ hrtimer_cancel(&bfqd->idle_slice_timer);
+
+ spin_lock_irq(&bfqd->lock);
+ list_for_each_entry_safe(bfqq, n, &bfqd->idle_list, bfqq_list)
+ bfq_deactivate_bfqq(bfqd, bfqq, false, false);
+ spin_unlock_irq(&bfqd->lock);
+
+ hrtimer_cancel(&bfqd->idle_slice_timer);
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ blkcg_deactivate_policy(bfqd->queue, &blkcg_policy_bfq);
+#else
+ spin_lock_irq(&bfqd->lock);
+ bfq_put_async_queues(bfqd, bfqd->root_group);
+ kfree(bfqd->root_group);
+ spin_unlock_irq(&bfqd->lock);
+#endif
+
+ kfree(bfqd);
+}
+
+static void bfq_init_root_group(struct bfq_group *root_group,
+ struct bfq_data *bfqd)
+{
+ int i;
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ root_group->entity.parent = NULL;
+ root_group->my_entity = NULL;
+ root_group->bfqd = bfqd;
+#endif
+ root_group->rq_pos_tree = RB_ROOT;
+ for (i = 0; i < BFQ_IOPRIO_CLASSES; i++)
+ root_group->sched_data.service_tree[i] = BFQ_SERVICE_TREE_INIT;
+ root_group->sched_data.bfq_class_idle_last_service = jiffies;
+}
+
+static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
+{
+ struct bfq_data *bfqd;
+ struct elevator_queue *eq;
+
+ eq = elevator_alloc(q, e);
+ if (!eq)
+ return -ENOMEM;
+
+ bfqd = kzalloc_node(sizeof(*bfqd), GFP_KERNEL, q->node);
+ if (!bfqd) {
+ kobject_put(&eq->kobj);
+ return -ENOMEM;
+ }
+ eq->elevator_data = bfqd;
+
+ spin_lock_irq(q->queue_lock);
+ q->elevator = eq;
+ spin_unlock_irq(q->queue_lock);
+
+ /*
+ * Our fallback bfqq if bfq_find_alloc_queue() runs into OOM issues.
+ * Grab a permanent reference to it, so that the normal code flow
+ * will not attempt to free it.
+ */
+ bfq_init_bfqq(bfqd, &bfqd->oom_bfqq, NULL, 1, 0);
+ bfqd->oom_bfqq.ref++;
+ bfqd->oom_bfqq.new_ioprio = BFQ_DEFAULT_QUEUE_IOPRIO;
+ bfqd->oom_bfqq.new_ioprio_class = IOPRIO_CLASS_BE;
+ bfqd->oom_bfqq.entity.new_weight =
+ bfq_ioprio_to_weight(bfqd->oom_bfqq.new_ioprio);
+
+ /* oom_bfqq does not participate to bursts */
+ bfq_clear_bfqq_just_created(&bfqd->oom_bfqq);
+
+ /*
+ * Trigger weight initialization, according to ioprio, at the
+ * oom_bfqq's first activation. The oom_bfqq's ioprio and ioprio
+ * class won't be changed any more.
+ */
+ bfqd->oom_bfqq.entity.prio_changed = 1;
+
+ bfqd->queue = q;
+
+ INIT_LIST_HEAD(&bfqd->dispatch);
+
+ hrtimer_init(&bfqd->idle_slice_timer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL);
+ bfqd->idle_slice_timer.function = bfq_idle_slice_timer;
+
+ bfqd->queue_weights_tree = RB_ROOT;
+ bfqd->group_weights_tree = RB_ROOT;
+
+ INIT_LIST_HEAD(&bfqd->active_list);
+ INIT_LIST_HEAD(&bfqd->idle_list);
+ INIT_HLIST_HEAD(&bfqd->burst_list);
+
+ bfqd->hw_tag = -1;
+
+ bfqd->bfq_max_budget = bfq_default_max_budget;
+
+ bfqd->bfq_fifo_expire[0] = bfq_fifo_expire[0];
+ bfqd->bfq_fifo_expire[1] = bfq_fifo_expire[1];
+ bfqd->bfq_back_max = bfq_back_max;
+ bfqd->bfq_back_penalty = bfq_back_penalty;
+ bfqd->bfq_slice_idle = bfq_slice_idle;
+ bfqd->bfq_timeout = bfq_timeout;
+
+ bfqd->bfq_requests_within_timer = 120;
+
+ bfqd->bfq_large_burst_thresh = 8;
+ bfqd->bfq_burst_interval = msecs_to_jiffies(180);
+
+ bfqd->low_latency = true;
+
+ /*
+ * Trade-off between responsiveness and fairness.
+ */
+ bfqd->bfq_wr_coeff = 30;
+ bfqd->bfq_wr_rt_max_time = msecs_to_jiffies(300);
+ bfqd->bfq_wr_max_time = 0;
+ bfqd->bfq_wr_min_idle_time = msecs_to_jiffies(2000);
+ bfqd->bfq_wr_min_inter_arr_async = msecs_to_jiffies(500);
+ bfqd->bfq_wr_max_softrt_rate = 7000; /*
+ * Approximate rate required
+ * to playback or record a
+ * high-definition compressed
+ * video.
+ */
+ bfqd->wr_busy_queues = 0;
+
+ /*
+ * Begin by assuming, optimistically, that the device is a
+ * high-speed one, and that its peak rate is equal to 2/3 of
+ * the highest reference rate.
+ */
+ bfqd->RT_prod = R_fast[blk_queue_nonrot(bfqd->queue)] *
+ T_fast[blk_queue_nonrot(bfqd->queue)];
+ bfqd->peak_rate = R_fast[blk_queue_nonrot(bfqd->queue)] * 2 / 3;
+ bfqd->device_speed = BFQ_BFQD_FAST;
+
+ spin_lock_init(&bfqd->lock);
+
+ /*
+ * The invocation of the next bfq_create_group_hierarchy
+ * function is the head of a chain of function calls
+ * (bfq_create_group_hierarchy->blkcg_activate_policy->
+ * blk_mq_freeze_queue) that may lead to the invocation of the
+ * has_work hook function. For this reason,
+ * bfq_create_group_hierarchy is invoked only after all
+ * scheduler data has been initialized, apart from the fields
+ * that can be initialized only after invoking
+ * bfq_create_group_hierarchy. This, in particular, enables
+ * has_work to correctly return false. Of course, to avoid
+ * other inconsistencies, the blk-mq stack must then refrain
+ * from invoking further scheduler hooks before this init
+ * function is finished.
+ */
+ bfqd->root_group = bfq_create_group_hierarchy(bfqd, q->node);
+ if (!bfqd->root_group)
+ goto out_free;
+ bfq_init_root_group(bfqd->root_group, bfqd);
+ bfq_init_entity(&bfqd->oom_bfqq.entity, bfqd->root_group);
+
+ wbt_disable_default(q);
+ return 0;
+
+out_free:
+ kfree(bfqd);
+ kobject_put(&eq->kobj);
+ return -ENOMEM;
+}
+
+static void bfq_slab_kill(void)
+{
+ kmem_cache_destroy(bfq_pool);
+}
+
+static int __init bfq_slab_setup(void)
+{
+ bfq_pool = KMEM_CACHE(bfq_queue, 0);
+ if (!bfq_pool)
+ return -ENOMEM;
+ return 0;
+}
+
+static ssize_t bfq_var_show(unsigned int var, char *page)
+{
+ return sprintf(page, "%u\n", var);
+}
+
+static int bfq_var_store(unsigned long *var, const char *page)
+{
+ unsigned long new_val;
+ int ret = kstrtoul(page, 10, &new_val);
+
+ if (ret)
+ return ret;
+ *var = new_val;
+ return 0;
+}
+
+#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
+static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+{ \
+ struct bfq_data *bfqd = e->elevator_data; \
+ u64 __data = __VAR; \
+ if (__CONV == 1) \
+ __data = jiffies_to_msecs(__data); \
+ else if (__CONV == 2) \
+ __data = div_u64(__data, NSEC_PER_MSEC); \
+ return bfq_var_show(__data, (page)); \
+}
+SHOW_FUNCTION(bfq_fifo_expire_sync_show, bfqd->bfq_fifo_expire[1], 2);
+SHOW_FUNCTION(bfq_fifo_expire_async_show, bfqd->bfq_fifo_expire[0], 2);
+SHOW_FUNCTION(bfq_back_seek_max_show, bfqd->bfq_back_max, 0);
+SHOW_FUNCTION(bfq_back_seek_penalty_show, bfqd->bfq_back_penalty, 0);
+SHOW_FUNCTION(bfq_slice_idle_show, bfqd->bfq_slice_idle, 2);
+SHOW_FUNCTION(bfq_max_budget_show, bfqd->bfq_user_max_budget, 0);
+SHOW_FUNCTION(bfq_timeout_sync_show, bfqd->bfq_timeout, 1);
+SHOW_FUNCTION(bfq_strict_guarantees_show, bfqd->strict_guarantees, 0);
+SHOW_FUNCTION(bfq_low_latency_show, bfqd->low_latency, 0);
+#undef SHOW_FUNCTION
+
+#define USEC_SHOW_FUNCTION(__FUNC, __VAR) \
+static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+{ \
+ struct bfq_data *bfqd = e->elevator_data; \
+ u64 __data = __VAR; \
+ __data = div_u64(__data, NSEC_PER_USEC); \
+ return bfq_var_show(__data, (page)); \
+}
+USEC_SHOW_FUNCTION(bfq_slice_idle_us_show, bfqd->bfq_slice_idle);
+#undef USEC_SHOW_FUNCTION
+
+#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
+static ssize_t \
+__FUNC(struct elevator_queue *e, const char *page, size_t count) \
+{ \
+ struct bfq_data *bfqd = e->elevator_data; \
+ unsigned long __data, __min = (MIN), __max = (MAX); \
+ int ret; \
+ \
+ ret = bfq_var_store(&__data, (page)); \
+ if (ret) \
+ return ret; \
+ if (__data < __min) \
+ __data = __min; \
+ else if (__data > __max) \
+ __data = __max; \
+ if (__CONV == 1) \
+ *(__PTR) = msecs_to_jiffies(__data); \
+ else if (__CONV == 2) \
+ *(__PTR) = (u64)__data * NSEC_PER_MSEC; \
+ else \
+ *(__PTR) = __data; \
+ return count; \
+}
+STORE_FUNCTION(bfq_fifo_expire_sync_store, &bfqd->bfq_fifo_expire[1], 1,
+ INT_MAX, 2);
+STORE_FUNCTION(bfq_fifo_expire_async_store, &bfqd->bfq_fifo_expire[0], 1,
+ INT_MAX, 2);
+STORE_FUNCTION(bfq_back_seek_max_store, &bfqd->bfq_back_max, 0, INT_MAX, 0);
+STORE_FUNCTION(bfq_back_seek_penalty_store, &bfqd->bfq_back_penalty, 1,
+ INT_MAX, 0);
+STORE_FUNCTION(bfq_slice_idle_store, &bfqd->bfq_slice_idle, 0, INT_MAX, 2);
+#undef STORE_FUNCTION
+
+#define USEC_STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)\
+{ \
+ struct bfq_data *bfqd = e->elevator_data; \
+ unsigned long __data, __min = (MIN), __max = (MAX); \
+ int ret; \
+ \
+ ret = bfq_var_store(&__data, (page)); \
+ if (ret) \
+ return ret; \
+ if (__data < __min) \
+ __data = __min; \
+ else if (__data > __max) \
+ __data = __max; \
+ *(__PTR) = (u64)__data * NSEC_PER_USEC; \
+ return count; \
+}
+USEC_STORE_FUNCTION(bfq_slice_idle_us_store, &bfqd->bfq_slice_idle, 0,
+ UINT_MAX);
+#undef USEC_STORE_FUNCTION
+
+static ssize_t bfq_max_budget_store(struct elevator_queue *e,
+ const char *page, size_t count)
+{
+ struct bfq_data *bfqd = e->elevator_data;
+ unsigned long __data;
+ int ret;
+
+ ret = bfq_var_store(&__data, (page));
+ if (ret)
+ return ret;
+
+ if (__data == 0)
+ bfqd->bfq_max_budget = bfq_calc_max_budget(bfqd);
+ else {
+ if (__data > INT_MAX)
+ __data = INT_MAX;
+ bfqd->bfq_max_budget = __data;
+ }
+
+ bfqd->bfq_user_max_budget = __data;
+
+ return count;
+}
+
+/*
+ * Leaving this name to preserve name compatibility with cfq
+ * parameters, but this timeout is used for both sync and async.
+ */
+static ssize_t bfq_timeout_sync_store(struct elevator_queue *e,
+ const char *page, size_t count)
+{
+ struct bfq_data *bfqd = e->elevator_data;
+ unsigned long __data;
+ int ret;
+
+ ret = bfq_var_store(&__data, (page));
+ if (ret)
+ return ret;
+
+ if (__data < 1)
+ __data = 1;
+ else if (__data > INT_MAX)
+ __data = INT_MAX;
+
+ bfqd->bfq_timeout = msecs_to_jiffies(__data);
+ if (bfqd->bfq_user_max_budget == 0)
+ bfqd->bfq_max_budget = bfq_calc_max_budget(bfqd);
+
+ return count;
+}
+
+static ssize_t bfq_strict_guarantees_store(struct elevator_queue *e,
+ const char *page, size_t count)
+{
+ struct bfq_data *bfqd = e->elevator_data;
+ unsigned long __data;
+ int ret;
+
+ ret = bfq_var_store(&__data, (page));
+ if (ret)
+ return ret;
+
+ if (__data > 1)
+ __data = 1;
+ if (!bfqd->strict_guarantees && __data == 1
+ && bfqd->bfq_slice_idle < 8 * NSEC_PER_MSEC)
+ bfqd->bfq_slice_idle = 8 * NSEC_PER_MSEC;
+
+ bfqd->strict_guarantees = __data;
+
+ return count;
+}
+
+static ssize_t bfq_low_latency_store(struct elevator_queue *e,
+ const char *page, size_t count)
+{
+ struct bfq_data *bfqd = e->elevator_data;
+ unsigned long __data;
+ int ret;
+
+ ret = bfq_var_store(&__data, (page));
+ if (ret)
+ return ret;
+
+ if (__data > 1)
+ __data = 1;
+ if (__data == 0 && bfqd->low_latency != 0)
+ bfq_end_wr(bfqd);
+ bfqd->low_latency = __data;
+
+ return count;
+}
+
+#define BFQ_ATTR(name) \
+ __ATTR(name, 0644, bfq_##name##_show, bfq_##name##_store)
+
+static struct elv_fs_entry bfq_attrs[] = {
+ BFQ_ATTR(fifo_expire_sync),
+ BFQ_ATTR(fifo_expire_async),
+ BFQ_ATTR(back_seek_max),
+ BFQ_ATTR(back_seek_penalty),
+ BFQ_ATTR(slice_idle),
+ BFQ_ATTR(slice_idle_us),
+ BFQ_ATTR(max_budget),
+ BFQ_ATTR(timeout_sync),
+ BFQ_ATTR(strict_guarantees),
+ BFQ_ATTR(low_latency),
+ __ATTR_NULL
+};
+
+static struct elevator_type iosched_bfq_mq = {
+ .ops.mq = {
+ .prepare_request = bfq_prepare_request,
+ .finish_request = bfq_finish_request,
+ .exit_icq = bfq_exit_icq,
+ .insert_requests = bfq_insert_requests,
+ .dispatch_request = bfq_dispatch_request,
+ .next_request = elv_rb_latter_request,
+ .former_request = elv_rb_former_request,
+ .allow_merge = bfq_allow_bio_merge,
+ .bio_merge = bfq_bio_merge,
+ .request_merge = bfq_request_merge,
+ .requests_merged = bfq_requests_merged,
+ .request_merged = bfq_request_merged,
+ .has_work = bfq_has_work,
+ .init_sched = bfq_init_queue,
+ .exit_sched = bfq_exit_queue,
+ },
+
+ .uses_mq = true,
+ .icq_size = sizeof(struct bfq_io_cq),
+ .icq_align = __alignof__(struct bfq_io_cq),
+ .elevator_attrs = bfq_attrs,
+ .elevator_name = "bfq",
+ .elevator_owner = THIS_MODULE,
+};
+MODULE_ALIAS("bfq-iosched");
+
+static int __init bfq_init(void)
+{
+ int ret;
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ ret = blkcg_policy_register(&blkcg_policy_bfq);
+ if (ret)
+ return ret;
+#endif
+
+ ret = -ENOMEM;
+ if (bfq_slab_setup())
+ goto err_pol_unreg;
+
+ /*
+ * Times to load large popular applications for the typical
+ * systems installed on the reference devices (see the
+ * comments before the definitions of the next two
+ * arrays). Actually, we use slightly slower values, as the
+ * estimated peak rate tends to be smaller than the actual
+ * peak rate. The reason for this last fact is that estimates
+ * are computed over much shorter time intervals than the long
+ * intervals typically used for benchmarking. Why? First, to
+ * adapt more quickly to variations. Second, because an I/O
+ * scheduler cannot rely on a peak-rate-evaluation workload to
+ * be run for a long time.
+ */
+ T_slow[0] = msecs_to_jiffies(3500); /* actually 4 sec */
+ T_slow[1] = msecs_to_jiffies(6000); /* actually 6.5 sec */
+ T_fast[0] = msecs_to_jiffies(7000); /* actually 8 sec */
+ T_fast[1] = msecs_to_jiffies(2500); /* actually 3 sec */
+
+ /*
+ * Thresholds that determine the switch between speed classes
+ * (see the comments before the definition of the array
+ * device_speed_thresh). These thresholds are biased towards
+ * transitions to the fast class. This is safer than the
+ * opposite bias. In fact, a wrong transition to the slow
+ * class results in short weight-raising periods, because the
+ * speed of the device then tends to be higher that the
+ * reference peak rate. On the opposite end, a wrong
+ * transition to the fast class tends to increase
+ * weight-raising periods, because of the opposite reason.
+ */
+ device_speed_thresh[0] = (4 * R_slow[0]) / 3;
+ device_speed_thresh[1] = (4 * R_slow[1]) / 3;
+
+ ret = elv_register(&iosched_bfq_mq);
+ if (ret)
+ goto slab_kill;
+
+ return 0;
+
+slab_kill:
+ bfq_slab_kill();
+err_pol_unreg:
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ blkcg_policy_unregister(&blkcg_policy_bfq);
+#endif
+ return ret;
+}
+
+static void __exit bfq_exit(void)
+{
+ elv_unregister(&iosched_bfq_mq);
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ blkcg_policy_unregister(&blkcg_policy_bfq);
+#endif
+ bfq_slab_kill();
+}
+
+module_init(bfq_init);
+module_exit(bfq_exit);
+
+MODULE_AUTHOR("Paolo Valente");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MQ Budget Fair Queueing I/O Scheduler");
diff --git a/src/kernel/linux/v4.14/block/bfq-iosched.h b/src/kernel/linux/v4.14/block/bfq-iosched.h
new file mode 100644
index 0000000..ac0809c
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/bfq-iosched.h
@@ -0,0 +1,956 @@
+/*
+ * Header file for the BFQ I/O scheduler: data structures and
+ * prototypes of interface functions among BFQ components.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#ifndef _BFQ_H
+#define _BFQ_H
+
+#include <linux/blktrace_api.h>
+#include <linux/hrtimer.h>
+#include <linux/blk-cgroup.h>
+
+#define BFQ_IOPRIO_CLASSES 3
+#define BFQ_CL_IDLE_TIMEOUT (HZ/5)
+
+#define BFQ_MIN_WEIGHT 1
+#define BFQ_MAX_WEIGHT 1000
+#define BFQ_WEIGHT_CONVERSION_COEFF 10
+
+#define BFQ_DEFAULT_QUEUE_IOPRIO 4
+
+#define BFQ_WEIGHT_LEGACY_DFL 100
+#define BFQ_DEFAULT_GRP_IOPRIO 0
+#define BFQ_DEFAULT_GRP_CLASS IOPRIO_CLASS_BE
+
+/*
+ * Soft real-time applications are extremely more latency sensitive
+ * than interactive ones. Over-raise the weight of the former to
+ * privilege them against the latter.
+ */
+#define BFQ_SOFTRT_WEIGHT_FACTOR 100
+
+struct bfq_entity;
+
+/**
+ * struct bfq_service_tree - per ioprio_class service tree.
+ *
+ * Each service tree represents a B-WF2Q+ scheduler on its own. Each
+ * ioprio_class has its own independent scheduler, and so its own
+ * bfq_service_tree. All the fields are protected by the queue lock
+ * of the containing bfqd.
+ */
+struct bfq_service_tree {
+ /* tree for active entities (i.e., those backlogged) */
+ struct rb_root active;
+ /* tree for idle entities (i.e., not backlogged, with V < F_i)*/
+ struct rb_root idle;
+
+ /* idle entity with minimum F_i */
+ struct bfq_entity *first_idle;
+ /* idle entity with maximum F_i */
+ struct bfq_entity *last_idle;
+
+ /* scheduler virtual time */
+ u64 vtime;
+ /* scheduler weight sum; active and idle entities contribute to it */
+ unsigned long wsum;
+};
+
+/**
+ * struct bfq_sched_data - multi-class scheduler.
+ *
+ * bfq_sched_data is the basic scheduler queue. It supports three
+ * ioprio_classes, and can be used either as a toplevel queue or as an
+ * intermediate queue in a hierarchical setup.
+ *
+ * The supported ioprio_classes are the same as in CFQ, in descending
+ * priority order, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE.
+ * Requests from higher priority queues are served before all the
+ * requests from lower priority queues; among requests of the same
+ * queue requests are served according to B-WF2Q+.
+ *
+ * The schedule is implemented by the service trees, plus the field
+ * @next_in_service, which points to the entity on the active trees
+ * that will be served next, if 1) no changes in the schedule occurs
+ * before the current in-service entity is expired, 2) the in-service
+ * queue becomes idle when it expires, and 3) if the entity pointed by
+ * in_service_entity is not a queue, then the in-service child entity
+ * of the entity pointed by in_service_entity becomes idle on
+ * expiration. This peculiar definition allows for the following
+ * optimization, not yet exploited: while a given entity is still in
+ * service, we already know which is the best candidate for next
+ * service among the other active entitities in the same parent
+ * entity. We can then quickly compare the timestamps of the
+ * in-service entity with those of such best candidate.
+ *
+ * All fields are protected by the lock of the containing bfqd.
+ */
+struct bfq_sched_data {
+ /* entity in service */
+ struct bfq_entity *in_service_entity;
+ /* head-of-line entity (see comments above) */
+ struct bfq_entity *next_in_service;
+ /* array of service trees, one per ioprio_class */
+ struct bfq_service_tree service_tree[BFQ_IOPRIO_CLASSES];
+ /* last time CLASS_IDLE was served */
+ unsigned long bfq_class_idle_last_service;
+
+};
+
+/**
+ * struct bfq_weight_counter - counter of the number of all active entities
+ * with a given weight.
+ */
+struct bfq_weight_counter {
+ unsigned int weight; /* weight of the entities this counter refers to */
+ unsigned int num_active; /* nr of active entities with this weight */
+ /*
+ * Weights tree member (see bfq_data's @queue_weights_tree and
+ * @group_weights_tree)
+ */
+ struct rb_node weights_node;
+};
+
+/**
+ * struct bfq_entity - schedulable entity.
+ *
+ * A bfq_entity is used to represent either a bfq_queue (leaf node in the
+ * cgroup hierarchy) or a bfq_group into the upper level scheduler. Each
+ * entity belongs to the sched_data of the parent group in the cgroup
+ * hierarchy. Non-leaf entities have also their own sched_data, stored
+ * in @my_sched_data.
+ *
+ * Each entity stores independently its priority values; this would
+ * allow different weights on different devices, but this
+ * functionality is not exported to userspace by now. Priorities and
+ * weights are updated lazily, first storing the new values into the
+ * new_* fields, then setting the @prio_changed flag. As soon as
+ * there is a transition in the entity state that allows the priority
+ * update to take place the effective and the requested priority
+ * values are synchronized.
+ *
+ * Unless cgroups are used, the weight value is calculated from the
+ * ioprio to export the same interface as CFQ. When dealing with
+ * ``well-behaved'' queues (i.e., queues that do not spend too much
+ * time to consume their budget and have true sequential behavior, and
+ * when there are no external factors breaking anticipation) the
+ * relative weights at each level of the cgroups hierarchy should be
+ * guaranteed. All the fields are protected by the queue lock of the
+ * containing bfqd.
+ */
+struct bfq_entity {
+ /* service_tree member */
+ struct rb_node rb_node;
+ /* pointer to the weight counter associated with this entity */
+ struct bfq_weight_counter *weight_counter;
+
+ /*
+ * Flag, true if the entity is on a tree (either the active or
+ * the idle one of its service_tree) or is in service.
+ */
+ bool on_st;
+
+ /* B-WF2Q+ start and finish timestamps [sectors/weight] */
+ u64 start, finish;
+
+ /* tree the entity is enqueued into; %NULL if not on a tree */
+ struct rb_root *tree;
+
+ /*
+ * minimum start time of the (active) subtree rooted at this
+ * entity; used for O(log N) lookups into active trees
+ */
+ u64 min_start;
+
+ /* amount of service received during the last service slot */
+ int service;
+
+ /* budget, used also to calculate F_i: F_i = S_i + @budget / @weight */
+ int budget;
+
+ /* weight of the queue */
+ int weight;
+ /* next weight if a change is in progress */
+ int new_weight;
+
+ /* original weight, used to implement weight boosting */
+ int orig_weight;
+
+ /* parent entity, for hierarchical scheduling */
+ struct bfq_entity *parent;
+
+ /*
+ * For non-leaf nodes in the hierarchy, the associated
+ * scheduler queue, %NULL on leaf nodes.
+ */
+ struct bfq_sched_data *my_sched_data;
+ /* the scheduler queue this entity belongs to */
+ struct bfq_sched_data *sched_data;
+
+ /* flag, set to request a weight, ioprio or ioprio_class change */
+ int prio_changed;
+};
+
+struct bfq_group;
+
+/**
+ * struct bfq_ttime - per process thinktime stats.
+ */
+struct bfq_ttime {
+ /* completion time of the last request */
+ u64 last_end_request;
+
+ /* total process thinktime */
+ u64 ttime_total;
+ /* number of thinktime samples */
+ unsigned long ttime_samples;
+ /* average process thinktime */
+ u64 ttime_mean;
+};
+
+/**
+ * struct bfq_queue - leaf schedulable entity.
+ *
+ * A bfq_queue is a leaf request queue; it can be associated with an
+ * io_context or more, if it is async or shared between cooperating
+ * processes. @cgroup holds a reference to the cgroup, to be sure that it
+ * does not disappear while a bfqq still references it (mostly to avoid
+ * races between request issuing and task migration followed by cgroup
+ * destruction).
+ * All the fields are protected by the queue lock of the containing bfqd.
+ */
+struct bfq_queue {
+ /* reference counter */
+ int ref;
+ /* parent bfq_data */
+ struct bfq_data *bfqd;
+
+ /* current ioprio and ioprio class */
+ unsigned short ioprio, ioprio_class;
+ /* next ioprio and ioprio class if a change is in progress */
+ unsigned short new_ioprio, new_ioprio_class;
+
+ /*
+ * Shared bfq_queue if queue is cooperating with one or more
+ * other queues.
+ */
+ struct bfq_queue *new_bfqq;
+ /* request-position tree member (see bfq_group's @rq_pos_tree) */
+ struct rb_node pos_node;
+ /* request-position tree root (see bfq_group's @rq_pos_tree) */
+ struct rb_root *pos_root;
+
+ /* sorted list of pending requests */
+ struct rb_root sort_list;
+ /* if fifo isn't expired, next request to serve */
+ struct request *next_rq;
+ /* number of sync and async requests queued */
+ int queued[2];
+ /* number of requests currently allocated */
+ int allocated;
+ /* number of pending metadata requests */
+ int meta_pending;
+ /* fifo list of requests in sort_list */
+ struct list_head fifo;
+
+ /* entity representing this queue in the scheduler */
+ struct bfq_entity entity;
+
+ /* maximum budget allowed from the feedback mechanism */
+ int max_budget;
+ /* budget expiration (in jiffies) */
+ unsigned long budget_timeout;
+
+ /* number of requests on the dispatch list or inside driver */
+ int dispatched;
+
+ /* status flags */
+ unsigned long flags;
+
+ /* node for active/idle bfqq list inside parent bfqd */
+ struct list_head bfqq_list;
+
+ /* associated @bfq_ttime struct */
+ struct bfq_ttime ttime;
+
+ /* bit vector: a 1 for each seeky requests in history */
+ u32 seek_history;
+
+ /* node for the device's burst list */
+ struct hlist_node burst_list_node;
+
+ /* position of the last request enqueued */
+ sector_t last_request_pos;
+
+ /* Number of consecutive pairs of request completion and
+ * arrival, such that the queue becomes idle after the
+ * completion, but the next request arrives within an idle
+ * time slice; used only if the queue's IO_bound flag has been
+ * cleared.
+ */
+ unsigned int requests_within_timer;
+
+ /* pid of the process owning the queue, used for logging purposes */
+ pid_t pid;
+
+ /*
+ * Pointer to the bfq_io_cq owning the bfq_queue, set to %NULL
+ * if the queue is shared.
+ */
+ struct bfq_io_cq *bic;
+
+ /* current maximum weight-raising time for this queue */
+ unsigned long wr_cur_max_time;
+ /*
+ * Minimum time instant such that, only if a new request is
+ * enqueued after this time instant in an idle @bfq_queue with
+ * no outstanding requests, then the task associated with the
+ * queue it is deemed as soft real-time (see the comments on
+ * the function bfq_bfqq_softrt_next_start())
+ */
+ unsigned long soft_rt_next_start;
+ /*
+ * Start time of the current weight-raising period if
+ * the @bfq-queue is being weight-raised, otherwise
+ * finish time of the last weight-raising period.
+ */
+ unsigned long last_wr_start_finish;
+ /* factor by which the weight of this queue is multiplied */
+ unsigned int wr_coeff;
+ /*
+ * Time of the last transition of the @bfq_queue from idle to
+ * backlogged.
+ */
+ unsigned long last_idle_bklogged;
+ /*
+ * Cumulative service received from the @bfq_queue since the
+ * last transition from idle to backlogged.
+ */
+ unsigned long service_from_backlogged;
+
+ /*
+ * Value of wr start time when switching to soft rt
+ */
+ unsigned long wr_start_at_switch_to_srt;
+
+ unsigned long split_time; /* time of last split */
+};
+
+/**
+ * struct bfq_io_cq - per (request_queue, io_context) structure.
+ */
+struct bfq_io_cq {
+ /* associated io_cq structure */
+ struct io_cq icq; /* must be the first member */
+ /* array of two process queues, the sync and the async */
+ struct bfq_queue *bfqq[2];
+ /* per (request_queue, blkcg) ioprio */
+ int ioprio;
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ uint64_t blkcg_serial_nr; /* the current blkcg serial */
+#endif
+ /*
+ * Snapshot of the has_short_time flag before merging; taken
+ * to remember its value while the queue is merged, so as to
+ * be able to restore it in case of split.
+ */
+ bool saved_has_short_ttime;
+ /*
+ * Same purpose as the previous two fields for the I/O bound
+ * classification of a queue.
+ */
+ bool saved_IO_bound;
+
+ /*
+ * Same purpose as the previous fields for the value of the
+ * field keeping the queue's belonging to a large burst
+ */
+ bool saved_in_large_burst;
+ /*
+ * True if the queue belonged to a burst list before its merge
+ * with another cooperating queue.
+ */
+ bool was_in_burst_list;
+
+ /*
+ * Similar to previous fields: save wr information.
+ */
+ unsigned long saved_wr_coeff;
+ unsigned long saved_last_wr_start_finish;
+ unsigned long saved_wr_start_at_switch_to_srt;
+ unsigned int saved_wr_cur_max_time;
+ struct bfq_ttime saved_ttime;
+};
+
+enum bfq_device_speed {
+ BFQ_BFQD_FAST,
+ BFQ_BFQD_SLOW,
+};
+
+/**
+ * struct bfq_data - per-device data structure.
+ *
+ * All the fields are protected by @lock.
+ */
+struct bfq_data {
+ /* device request queue */
+ struct request_queue *queue;
+ /* dispatch queue */
+ struct list_head dispatch;
+
+ /* root bfq_group for the device */
+ struct bfq_group *root_group;
+
+ /*
+ * rbtree of weight counters of @bfq_queues, sorted by
+ * weight. Used to keep track of whether all @bfq_queues have
+ * the same weight. The tree contains one counter for each
+ * distinct weight associated to some active and not
+ * weight-raised @bfq_queue (see the comments to the functions
+ * bfq_weights_tree_[add|remove] for further details).
+ */
+ struct rb_root queue_weights_tree;
+ /*
+ * rbtree of non-queue @bfq_entity weight counters, sorted by
+ * weight. Used to keep track of whether all @bfq_groups have
+ * the same weight. The tree contains one counter for each
+ * distinct weight associated to some active @bfq_group (see
+ * the comments to the functions bfq_weights_tree_[add|remove]
+ * for further details).
+ */
+ struct rb_root group_weights_tree;
+
+ /*
+ * Number of bfq_queues containing requests (including the
+ * queue in service, even if it is idling).
+ */
+ int busy_queues;
+ /* number of weight-raised busy @bfq_queues */
+ int wr_busy_queues;
+ /* number of queued requests */
+ int queued;
+ /* number of requests dispatched and waiting for completion */
+ int rq_in_driver;
+
+ /*
+ * Maximum number of requests in driver in the last
+ * @hw_tag_samples completed requests.
+ */
+ int max_rq_in_driver;
+ /* number of samples used to calculate hw_tag */
+ int hw_tag_samples;
+ /* flag set to one if the driver is showing a queueing behavior */
+ int hw_tag;
+
+ /* number of budgets assigned */
+ int budgets_assigned;
+
+ /*
+ * Timer set when idling (waiting) for the next request from
+ * the queue in service.
+ */
+ struct hrtimer idle_slice_timer;
+
+ /* bfq_queue in service */
+ struct bfq_queue *in_service_queue;
+
+ /* on-disk position of the last served request */
+ sector_t last_position;
+
+ /* time of last request completion (ns) */
+ u64 last_completion;
+
+ /* time of first rq dispatch in current observation interval (ns) */
+ u64 first_dispatch;
+ /* time of last rq dispatch in current observation interval (ns) */
+ u64 last_dispatch;
+
+ /* beginning of the last budget */
+ ktime_t last_budget_start;
+ /* beginning of the last idle slice */
+ ktime_t last_idling_start;
+
+ /* number of samples in current observation interval */
+ int peak_rate_samples;
+ /* num of samples of seq dispatches in current observation interval */
+ u32 sequential_samples;
+ /* total num of sectors transferred in current observation interval */
+ u64 tot_sectors_dispatched;
+ /* max rq size seen during current observation interval (sectors) */
+ u32 last_rq_max_size;
+ /* time elapsed from first dispatch in current observ. interval (us) */
+ u64 delta_from_first;
+ /*
+ * Current estimate of the device peak rate, measured in
+ * [BFQ_RATE_SHIFT * sectors/usec]. The left-shift by
+ * BFQ_RATE_SHIFT is performed to increase precision in
+ * fixed-point calculations.
+ */
+ u32 peak_rate;
+
+ /* maximum budget allotted to a bfq_queue before rescheduling */
+ int bfq_max_budget;
+
+ /* list of all the bfq_queues active on the device */
+ struct list_head active_list;
+ /* list of all the bfq_queues idle on the device */
+ struct list_head idle_list;
+
+ /*
+ * Timeout for async/sync requests; when it fires, requests
+ * are served in fifo order.
+ */
+ u64 bfq_fifo_expire[2];
+ /* weight of backward seeks wrt forward ones */
+ unsigned int bfq_back_penalty;
+ /* maximum allowed backward seek */
+ unsigned int bfq_back_max;
+ /* maximum idling time */
+ u32 bfq_slice_idle;
+
+ /* user-configured max budget value (0 for auto-tuning) */
+ int bfq_user_max_budget;
+ /*
+ * Timeout for bfq_queues to consume their budget; used to
+ * prevent seeky queues from imposing long latencies to
+ * sequential or quasi-sequential ones (this also implies that
+ * seeky queues cannot receive guarantees in the service
+ * domain; after a timeout they are charged for the time they
+ * have been in service, to preserve fairness among them, but
+ * without service-domain guarantees).
+ */
+ unsigned int bfq_timeout;
+
+ /*
+ * Number of consecutive requests that must be issued within
+ * the idle time slice to set again idling to a queue which
+ * was marked as non-I/O-bound (see the definition of the
+ * IO_bound flag for further details).
+ */
+ unsigned int bfq_requests_within_timer;
+
+ /*
+ * Force device idling whenever needed to provide accurate
+ * service guarantees, without caring about throughput
+ * issues. CAVEAT: this may even increase latencies, in case
+ * of useless idling for processes that did stop doing I/O.
+ */
+ bool strict_guarantees;
+
+ /*
+ * Last time at which a queue entered the current burst of
+ * queues being activated shortly after each other; for more
+ * details about this and the following parameters related to
+ * a burst of activations, see the comments on the function
+ * bfq_handle_burst.
+ */
+ unsigned long last_ins_in_burst;
+ /*
+ * Reference time interval used to decide whether a queue has
+ * been activated shortly after @last_ins_in_burst.
+ */
+ unsigned long bfq_burst_interval;
+ /* number of queues in the current burst of queue activations */
+ int burst_size;
+
+ /* common parent entity for the queues in the burst */
+ struct bfq_entity *burst_parent_entity;
+ /* Maximum burst size above which the current queue-activation
+ * burst is deemed as 'large'.
+ */
+ unsigned long bfq_large_burst_thresh;
+ /* true if a large queue-activation burst is in progress */
+ bool large_burst;
+ /*
+ * Head of the burst list (as for the above fields, more
+ * details in the comments on the function bfq_handle_burst).
+ */
+ struct hlist_head burst_list;
+
+ /* if set to true, low-latency heuristics are enabled */
+ bool low_latency;
+ /*
+ * Maximum factor by which the weight of a weight-raised queue
+ * is multiplied.
+ */
+ unsigned int bfq_wr_coeff;
+ /* maximum duration of a weight-raising period (jiffies) */
+ unsigned int bfq_wr_max_time;
+
+ /* Maximum weight-raising duration for soft real-time processes */
+ unsigned int bfq_wr_rt_max_time;
+ /*
+ * Minimum idle period after which weight-raising may be
+ * reactivated for a queue (in jiffies).
+ */
+ unsigned int bfq_wr_min_idle_time;
+ /*
+ * Minimum period between request arrivals after which
+ * weight-raising may be reactivated for an already busy async
+ * queue (in jiffies).
+ */
+ unsigned long bfq_wr_min_inter_arr_async;
+
+ /* Max service-rate for a soft real-time queue, in sectors/sec */
+ unsigned int bfq_wr_max_softrt_rate;
+ /*
+ * Cached value of the product R*T, used for computing the
+ * maximum duration of weight raising automatically.
+ */
+ u64 RT_prod;
+ /* device-speed class for the low-latency heuristic */
+ enum bfq_device_speed device_speed;
+
+ /* fallback dummy bfqq for extreme OOM conditions */
+ struct bfq_queue oom_bfqq;
+
+ spinlock_t lock;
+
+ /*
+ * bic associated with the task issuing current bio for
+ * merging. This and the next field are used as a support to
+ * be able to perform the bic lookup, needed by bio-merge
+ * functions, before the scheduler lock is taken, and thus
+ * avoid taking the request-queue lock while the scheduler
+ * lock is being held.
+ */
+ struct bfq_io_cq *bio_bic;
+ /* bfqq associated with the task issuing current bio for merging */
+ struct bfq_queue *bio_bfqq;
+};
+
+enum bfqq_state_flags {
+ BFQQF_just_created = 0, /* queue just allocated */
+ BFQQF_busy, /* has requests or is in service */
+ BFQQF_wait_request, /* waiting for a request */
+ BFQQF_non_blocking_wait_rq, /*
+ * waiting for a request
+ * without idling the device
+ */
+ BFQQF_fifo_expire, /* FIFO checked in this slice */
+ BFQQF_has_short_ttime, /* queue has a short think time */
+ BFQQF_sync, /* synchronous queue */
+ BFQQF_IO_bound, /*
+ * bfqq has timed-out at least once
+ * having consumed at most 2/10 of
+ * its budget
+ */
+ BFQQF_in_large_burst, /*
+ * bfqq activated in a large burst,
+ * see comments to bfq_handle_burst.
+ */
+ BFQQF_softrt_update, /*
+ * may need softrt-next-start
+ * update
+ */
+ BFQQF_coop, /* bfqq is shared */
+ BFQQF_split_coop /* shared bfqq will be split */
+};
+
+#define BFQ_BFQQ_FNS(name) \
+void bfq_mark_bfqq_##name(struct bfq_queue *bfqq); \
+void bfq_clear_bfqq_##name(struct bfq_queue *bfqq); \
+int bfq_bfqq_##name(const struct bfq_queue *bfqq);
+
+BFQ_BFQQ_FNS(just_created);
+BFQ_BFQQ_FNS(busy);
+BFQ_BFQQ_FNS(wait_request);
+BFQ_BFQQ_FNS(non_blocking_wait_rq);
+BFQ_BFQQ_FNS(fifo_expire);
+BFQ_BFQQ_FNS(has_short_ttime);
+BFQ_BFQQ_FNS(sync);
+BFQ_BFQQ_FNS(IO_bound);
+BFQ_BFQQ_FNS(in_large_burst);
+BFQ_BFQQ_FNS(coop);
+BFQ_BFQQ_FNS(split_coop);
+BFQ_BFQQ_FNS(softrt_update);
+#undef BFQ_BFQQ_FNS
+
+/* Expiration reasons. */
+enum bfqq_expiration {
+ BFQQE_TOO_IDLE = 0, /*
+ * queue has been idling for
+ * too long
+ */
+ BFQQE_BUDGET_TIMEOUT, /* budget took too long to be used */
+ BFQQE_BUDGET_EXHAUSTED, /* budget consumed */
+ BFQQE_NO_MORE_REQUESTS, /* the queue has no more requests */
+ BFQQE_PREEMPTED /* preemption in progress */
+};
+
+struct bfqg_stats {
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ /* number of ios merged */
+ struct blkg_rwstat merged;
+ /* total time spent on device in ns, may not be accurate w/ queueing */
+ struct blkg_rwstat service_time;
+ /* total time spent waiting in scheduler queue in ns */
+ struct blkg_rwstat wait_time;
+ /* number of IOs queued up */
+ struct blkg_rwstat queued;
+ /* total disk time and nr sectors dispatched by this group */
+ struct blkg_stat time;
+ /* sum of number of ios queued across all samples */
+ struct blkg_stat avg_queue_size_sum;
+ /* count of samples taken for average */
+ struct blkg_stat avg_queue_size_samples;
+ /* how many times this group has been removed from service tree */
+ struct blkg_stat dequeue;
+ /* total time spent waiting for it to be assigned a timeslice. */
+ struct blkg_stat group_wait_time;
+ /* time spent idling for this blkcg_gq */
+ struct blkg_stat idle_time;
+ /* total time with empty current active q with other requests queued */
+ struct blkg_stat empty_time;
+ /* fields after this shouldn't be cleared on stat reset */
+ uint64_t start_group_wait_time;
+ uint64_t start_idle_time;
+ uint64_t start_empty_time;
+ uint16_t flags;
+#endif /* CONFIG_BFQ_GROUP_IOSCHED */
+};
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+
+/*
+ * struct bfq_group_data - per-blkcg storage for the blkio subsystem.
+ *
+ * @ps: @blkcg_policy_storage that this structure inherits
+ * @weight: weight of the bfq_group
+ */
+struct bfq_group_data {
+ /* must be the first member */
+ struct blkcg_policy_data pd;
+
+ unsigned int weight;
+};
+
+/**
+ * struct bfq_group - per (device, cgroup) data structure.
+ * @entity: schedulable entity to insert into the parent group sched_data.
+ * @sched_data: own sched_data, to contain child entities (they may be
+ * both bfq_queues and bfq_groups).
+ * @bfqd: the bfq_data for the device this group acts upon.
+ * @async_bfqq: array of async queues for all the tasks belonging to
+ * the group, one queue per ioprio value per ioprio_class,
+ * except for the idle class that has only one queue.
+ * @async_idle_bfqq: async queue for the idle class (ioprio is ignored).
+ * @my_entity: pointer to @entity, %NULL for the toplevel group; used
+ * to avoid too many special cases during group creation/
+ * migration.
+ * @stats: stats for this bfqg.
+ * @active_entities: number of active entities belonging to the group;
+ * unused for the root group. Used to know whether there
+ * are groups with more than one active @bfq_entity
+ * (see the comments to the function
+ * bfq_bfqq_may_idle()).
+ * @rq_pos_tree: rbtree sorted by next_request position, used when
+ * determining if two or more queues have interleaving
+ * requests (see bfq_find_close_cooperator()).
+ *
+ * Each (device, cgroup) pair has its own bfq_group, i.e., for each cgroup
+ * there is a set of bfq_groups, each one collecting the lower-level
+ * entities belonging to the group that are acting on the same device.
+ *
+ * Locking works as follows:
+ * o @bfqd is protected by the queue lock, RCU is used to access it
+ * from the readers.
+ * o All the other fields are protected by the @bfqd queue lock.
+ */
+struct bfq_group {
+ /* must be the first member */
+ struct blkg_policy_data pd;
+
+ /* cached path for this blkg (see comments in bfq_bic_update_cgroup) */
+ char blkg_path[128];
+
+ /* reference counter (see comments in bfq_bic_update_cgroup) */
+ int ref;
+
+ struct bfq_entity entity;
+ struct bfq_sched_data sched_data;
+
+ void *bfqd;
+
+ struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR];
+ struct bfq_queue *async_idle_bfqq;
+
+ struct bfq_entity *my_entity;
+
+ int active_entities;
+
+ struct rb_root rq_pos_tree;
+
+ struct bfqg_stats stats;
+};
+
+#else
+struct bfq_group {
+ struct bfq_sched_data sched_data;
+
+ struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR];
+ struct bfq_queue *async_idle_bfqq;
+
+ struct rb_root rq_pos_tree;
+};
+#endif
+
+struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity);
+
+/* --------------- main algorithm interface ----------------- */
+
+#define BFQ_SERVICE_TREE_INIT ((struct bfq_service_tree) \
+ { RB_ROOT, RB_ROOT, NULL, NULL, 0, 0 })
+
+extern const int bfq_timeout;
+
+struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, bool is_sync);
+void bic_set_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq, bool is_sync);
+struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic);
+void bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq);
+void bfq_weights_tree_add(struct bfq_data *bfqd, struct bfq_entity *entity,
+ struct rb_root *root);
+void bfq_weights_tree_remove(struct bfq_data *bfqd, struct bfq_entity *entity,
+ struct rb_root *root);
+void bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ bool compensate, enum bfqq_expiration reason);
+void bfq_put_queue(struct bfq_queue *bfqq);
+void bfq_end_wr_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg);
+void bfq_schedule_dispatch(struct bfq_data *bfqd);
+void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg);
+
+/* ------------ end of main algorithm interface -------------- */
+
+/* ---------------- cgroups-support interface ---------------- */
+
+void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq,
+ unsigned int op);
+void bfqg_stats_update_io_remove(struct bfq_group *bfqg, unsigned int op);
+void bfqg_stats_update_io_merged(struct bfq_group *bfqg, unsigned int op);
+void bfqg_stats_update_completion(struct bfq_group *bfqg, uint64_t start_time,
+ uint64_t io_start_time, unsigned int op);
+void bfqg_stats_update_dequeue(struct bfq_group *bfqg);
+void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg);
+void bfqg_stats_update_idle_time(struct bfq_group *bfqg);
+void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg);
+void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg);
+void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ struct bfq_group *bfqg);
+
+void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg);
+void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio);
+void bfq_end_wr_async(struct bfq_data *bfqd);
+struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd,
+ struct blkcg *blkcg);
+struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg);
+struct bfq_group *bfqq_group(struct bfq_queue *bfqq);
+struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node);
+void bfqg_and_blkg_put(struct bfq_group *bfqg);
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+extern struct cftype bfq_blkcg_legacy_files[];
+extern struct cftype bfq_blkg_files[];
+extern struct blkcg_policy blkcg_policy_bfq;
+#endif
+
+/* ------------- end of cgroups-support interface ------------- */
+
+/* - interface of the internal hierarchical B-WF2Q+ scheduler - */
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+/* both next loops stop at one of the child entities of the root group */
+#define for_each_entity(entity) \
+ for (; entity ; entity = entity->parent)
+
+/*
+ * For each iteration, compute parent in advance, so as to be safe if
+ * entity is deallocated during the iteration. Such a deallocation may
+ * happen as a consequence of a bfq_put_queue that frees the bfq_queue
+ * containing entity.
+ */
+#define for_each_entity_safe(entity, parent) \
+ for (; entity && ({ parent = entity->parent; 1; }); entity = parent)
+
+#else /* CONFIG_BFQ_GROUP_IOSCHED */
+/*
+ * Next two macros are fake loops when cgroups support is not
+ * enabled. I fact, in such a case, there is only one level to go up
+ * (to reach the root group).
+ */
+#define for_each_entity(entity) \
+ for (; entity ; entity = NULL)
+
+#define for_each_entity_safe(entity, parent) \
+ for (parent = NULL; entity ; entity = parent)
+#endif /* CONFIG_BFQ_GROUP_IOSCHED */
+
+struct bfq_group *bfq_bfqq_to_bfqg(struct bfq_queue *bfqq);
+struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity);
+struct bfq_service_tree *bfq_entity_service_tree(struct bfq_entity *entity);
+struct bfq_entity *bfq_entity_of(struct rb_node *node);
+unsigned short bfq_ioprio_to_weight(int ioprio);
+void bfq_put_idle_entity(struct bfq_service_tree *st,
+ struct bfq_entity *entity);
+struct bfq_service_tree *
+__bfq_entity_update_weight_prio(struct bfq_service_tree *old_st,
+ struct bfq_entity *entity,
+ bool update_class_too);
+void bfq_bfqq_served(struct bfq_queue *bfqq, int served);
+void bfq_bfqq_charge_time(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ unsigned long time_ms);
+bool __bfq_deactivate_entity(struct bfq_entity *entity,
+ bool ins_into_idle_tree);
+bool next_queue_may_preempt(struct bfq_data *bfqd);
+struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd);
+void __bfq_bfqd_reset_in_service(struct bfq_data *bfqd);
+void bfq_deactivate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ bool ins_into_idle_tree, bool expiration);
+void bfq_activate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq);
+void bfq_requeue_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ bool expiration);
+void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ bool expiration);
+void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq);
+
+/* --------------- end of interface of B-WF2Q+ ---------------- */
+
+/* Logging facilities. */
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+struct bfq_group *bfqq_group(struct bfq_queue *bfqq);
+
+#define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \
+ blk_add_cgroup_trace_msg((bfqd)->queue, \
+ bfqg_to_blkg(bfqq_group(bfqq))->blkcg, \
+ "bfq%d%c " fmt, (bfqq)->pid, \
+ bfq_bfqq_sync((bfqq)) ? 'S' : 'A', ##args); \
+} while (0)
+
+#define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do { \
+ blk_add_cgroup_trace_msg((bfqd)->queue, \
+ bfqg_to_blkg(bfqg)->blkcg, fmt, ##args); \
+} while (0)
+
+#else /* CONFIG_BFQ_GROUP_IOSCHED */
+
+#define bfq_log_bfqq(bfqd, bfqq, fmt, args...) \
+ blk_add_trace_msg((bfqd)->queue, "bfq%d%c " fmt, (bfqq)->pid, \
+ bfq_bfqq_sync((bfqq)) ? 'S' : 'A', \
+ ##args)
+#define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do {} while (0)
+
+#endif /* CONFIG_BFQ_GROUP_IOSCHED */
+
+#define bfq_log(bfqd, fmt, args...) \
+ blk_add_trace_msg((bfqd)->queue, "bfq " fmt, ##args)
+
+#endif /* _BFQ_H */
diff --git a/src/kernel/linux/v4.14/block/bfq-wf2q.c b/src/kernel/linux/v4.14/block/bfq-wf2q.c
new file mode 100644
index 0000000..c172760
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/bfq-wf2q.c
@@ -0,0 +1,1698 @@
+/*
+ * Hierarchical Budget Worst-case Fair Weighted Fair Queueing
+ * (B-WF2Q+): hierarchical scheduling algorithm by which the BFQ I/O
+ * scheduler schedules generic entities. The latter can represent
+ * either single bfq queues (associated with processes) or groups of
+ * bfq queues (associated with cgroups).
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#include "bfq-iosched.h"
+
+/**
+ * bfq_gt - compare two timestamps.
+ * @a: first ts.
+ * @b: second ts.
+ *
+ * Return @a > @b, dealing with wrapping correctly.
+ */
+static int bfq_gt(u64 a, u64 b)
+{
+ return (s64)(a - b) > 0;
+}
+
+static struct bfq_entity *bfq_root_active_entity(struct rb_root *tree)
+{
+ struct rb_node *node = tree->rb_node;
+
+ return rb_entry(node, struct bfq_entity, rb_node);
+}
+
+static unsigned int bfq_class_idx(struct bfq_entity *entity)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+
+ return bfqq ? bfqq->ioprio_class - 1 :
+ BFQ_DEFAULT_GRP_CLASS - 1;
+}
+
+static struct bfq_entity *bfq_lookup_next_entity(struct bfq_sched_data *sd,
+ bool expiration);
+
+static bool bfq_update_parent_budget(struct bfq_entity *next_in_service);
+
+/**
+ * bfq_update_next_in_service - update sd->next_in_service
+ * @sd: sched_data for which to perform the update.
+ * @new_entity: if not NULL, pointer to the entity whose activation,
+ * requeueing or repositionig triggered the invocation of
+ * this function.
+ * @expiration: id true, this function is being invoked after the
+ * expiration of the in-service entity
+ *
+ * This function is called to update sd->next_in_service, which, in
+ * its turn, may change as a consequence of the insertion or
+ * extraction of an entity into/from one of the active trees of
+ * sd. These insertions/extractions occur as a consequence of
+ * activations/deactivations of entities, with some activations being
+ * 'true' activations, and other activations being requeueings (i.e.,
+ * implementing the second, requeueing phase of the mechanism used to
+ * reposition an entity in its active tree; see comments on
+ * __bfq_activate_entity and __bfq_requeue_entity for details). In
+ * both the last two activation sub-cases, new_entity points to the
+ * just activated or requeued entity.
+ *
+ * Returns true if sd->next_in_service changes in such a way that
+ * entity->parent may become the next_in_service for its parent
+ * entity.
+ */
+static bool bfq_update_next_in_service(struct bfq_sched_data *sd,
+ struct bfq_entity *new_entity,
+ bool expiration)
+{
+ struct bfq_entity *next_in_service = sd->next_in_service;
+ bool parent_sched_may_change = false;
+ bool change_without_lookup = false;
+
+ /*
+ * If this update is triggered by the activation, requeueing
+ * or repositiong of an entity that does not coincide with
+ * sd->next_in_service, then a full lookup in the active tree
+ * can be avoided. In fact, it is enough to check whether the
+ * just-modified entity has the same priority as
+ * sd->next_in_service, is eligible and has a lower virtual
+ * finish time than sd->next_in_service. If this compound
+ * condition holds, then the new entity becomes the new
+ * next_in_service. Otherwise no change is needed.
+ */
+ if (new_entity && new_entity != sd->next_in_service) {
+ /*
+ * Flag used to decide whether to replace
+ * sd->next_in_service with new_entity. Tentatively
+ * set to true, and left as true if
+ * sd->next_in_service is NULL.
+ */
+ change_without_lookup = true;
+
+ /*
+ * If there is already a next_in_service candidate
+ * entity, then compare timestamps to decide whether
+ * to replace sd->service_tree with new_entity.
+ */
+ if (next_in_service) {
+ unsigned int new_entity_class_idx =
+ bfq_class_idx(new_entity);
+ struct bfq_service_tree *st =
+ sd->service_tree + new_entity_class_idx;
+
+ change_without_lookup =
+ (new_entity_class_idx ==
+ bfq_class_idx(next_in_service)
+ &&
+ !bfq_gt(new_entity->start, st->vtime)
+ &&
+ bfq_gt(next_in_service->finish,
+ new_entity->finish));
+ }
+
+ if (change_without_lookup)
+ next_in_service = new_entity;
+ }
+
+ if (!change_without_lookup) /* lookup needed */
+ next_in_service = bfq_lookup_next_entity(sd, expiration);
+
+ if (next_in_service)
+ parent_sched_may_change = !sd->next_in_service ||
+ bfq_update_parent_budget(next_in_service);
+
+ sd->next_in_service = next_in_service;
+
+ if (!next_in_service)
+ return parent_sched_may_change;
+
+ return parent_sched_may_change;
+}
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+
+struct bfq_group *bfq_bfqq_to_bfqg(struct bfq_queue *bfqq)
+{
+ struct bfq_entity *group_entity = bfqq->entity.parent;
+
+ if (!group_entity)
+ group_entity = &bfqq->bfqd->root_group->entity;
+
+ return container_of(group_entity, struct bfq_group, entity);
+}
+
+/*
+ * Returns true if this budget changes may let next_in_service->parent
+ * become the next_in_service entity for its parent entity.
+ */
+static bool bfq_update_parent_budget(struct bfq_entity *next_in_service)
+{
+ struct bfq_entity *bfqg_entity;
+ struct bfq_group *bfqg;
+ struct bfq_sched_data *group_sd;
+ bool ret = false;
+
+ group_sd = next_in_service->sched_data;
+
+ bfqg = container_of(group_sd, struct bfq_group, sched_data);
+ /*
+ * bfq_group's my_entity field is not NULL only if the group
+ * is not the root group. We must not touch the root entity
+ * as it must never become an in-service entity.
+ */
+ bfqg_entity = bfqg->my_entity;
+ if (bfqg_entity) {
+ if (bfqg_entity->budget > next_in_service->budget)
+ ret = true;
+ bfqg_entity->budget = next_in_service->budget;
+ }
+
+ return ret;
+}
+
+/*
+ * This function tells whether entity stops being a candidate for next
+ * service, according to the restrictive definition of the field
+ * next_in_service. In particular, this function is invoked for an
+ * entity that is about to be set in service.
+ *
+ * If entity is a queue, then the entity is no longer a candidate for
+ * next service according to the that definition, because entity is
+ * about to become the in-service queue. This function then returns
+ * true if entity is a queue.
+ *
+ * In contrast, entity could still be a candidate for next service if
+ * it is not a queue, and has more than one active child. In fact,
+ * even if one of its children is about to be set in service, other
+ * active children may still be the next to serve, for the parent
+ * entity, even according to the above definition. As a consequence, a
+ * non-queue entity is not a candidate for next-service only if it has
+ * only one active child. And only if this condition holds, then this
+ * function returns true for a non-queue entity.
+ */
+static bool bfq_no_longer_next_in_service(struct bfq_entity *entity)
+{
+ struct bfq_group *bfqg;
+
+ if (bfq_entity_to_bfqq(entity))
+ return true;
+
+ bfqg = container_of(entity, struct bfq_group, entity);
+
+ /*
+ * The field active_entities does not always contain the
+ * actual number of active children entities: it happens to
+ * not account for the in-service entity in case the latter is
+ * removed from its active tree (which may get done after
+ * invoking the function bfq_no_longer_next_in_service in
+ * bfq_get_next_queue). Fortunately, here, i.e., while
+ * bfq_no_longer_next_in_service is not yet completed in
+ * bfq_get_next_queue, bfq_active_extract has not yet been
+ * invoked, and thus active_entities still coincides with the
+ * actual number of active entities.
+ */
+ if (bfqg->active_entities == 1)
+ return true;
+
+ return false;
+}
+
+#else /* CONFIG_BFQ_GROUP_IOSCHED */
+
+struct bfq_group *bfq_bfqq_to_bfqg(struct bfq_queue *bfqq)
+{
+ return bfqq->bfqd->root_group;
+}
+
+static bool bfq_update_parent_budget(struct bfq_entity *next_in_service)
+{
+ return false;
+}
+
+static bool bfq_no_longer_next_in_service(struct bfq_entity *entity)
+{
+ return true;
+}
+
+#endif /* CONFIG_BFQ_GROUP_IOSCHED */
+
+/*
+ * Shift for timestamp calculations. This actually limits the maximum
+ * service allowed in one timestamp delta (small shift values increase it),
+ * the maximum total weight that can be used for the queues in the system
+ * (big shift values increase it), and the period of virtual time
+ * wraparounds.
+ */
+#define WFQ_SERVICE_SHIFT 22
+
+struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity)
+{
+ struct bfq_queue *bfqq = NULL;
+
+ if (!entity->my_sched_data)
+ bfqq = container_of(entity, struct bfq_queue, entity);
+
+ return bfqq;
+}
+
+
+/**
+ * bfq_delta - map service into the virtual time domain.
+ * @service: amount of service.
+ * @weight: scale factor (weight of an entity or weight sum).
+ */
+static u64 bfq_delta(unsigned long service, unsigned long weight)
+{
+ u64 d = (u64)service << WFQ_SERVICE_SHIFT;
+
+ do_div(d, weight);
+ return d;
+}
+
+/**
+ * bfq_calc_finish - assign the finish time to an entity.
+ * @entity: the entity to act upon.
+ * @service: the service to be charged to the entity.
+ */
+static void bfq_calc_finish(struct bfq_entity *entity, unsigned long service)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+
+ entity->finish = entity->start +
+ bfq_delta(service, entity->weight);
+
+ if (bfqq) {
+ bfq_log_bfqq(bfqq->bfqd, bfqq,
+ "calc_finish: serv %lu, w %d",
+ service, entity->weight);
+ bfq_log_bfqq(bfqq->bfqd, bfqq,
+ "calc_finish: start %llu, finish %llu, delta %llu",
+ entity->start, entity->finish,
+ bfq_delta(service, entity->weight));
+ }
+}
+
+/**
+ * bfq_entity_of - get an entity from a node.
+ * @node: the node field of the entity.
+ *
+ * Convert a node pointer to the relative entity. This is used only
+ * to simplify the logic of some functions and not as the generic
+ * conversion mechanism because, e.g., in the tree walking functions,
+ * the check for a %NULL value would be redundant.
+ */
+struct bfq_entity *bfq_entity_of(struct rb_node *node)
+{
+ struct bfq_entity *entity = NULL;
+
+ if (node)
+ entity = rb_entry(node, struct bfq_entity, rb_node);
+
+ return entity;
+}
+
+/**
+ * bfq_extract - remove an entity from a tree.
+ * @root: the tree root.
+ * @entity: the entity to remove.
+ */
+static void bfq_extract(struct rb_root *root, struct bfq_entity *entity)
+{
+ entity->tree = NULL;
+ rb_erase(&entity->rb_node, root);
+}
+
+/**
+ * bfq_idle_extract - extract an entity from the idle tree.
+ * @st: the service tree of the owning @entity.
+ * @entity: the entity being removed.
+ */
+static void bfq_idle_extract(struct bfq_service_tree *st,
+ struct bfq_entity *entity)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+ struct rb_node *next;
+
+ if (entity == st->first_idle) {
+ next = rb_next(&entity->rb_node);
+ st->first_idle = bfq_entity_of(next);
+ }
+
+ if (entity == st->last_idle) {
+ next = rb_prev(&entity->rb_node);
+ st->last_idle = bfq_entity_of(next);
+ }
+
+ bfq_extract(&st->idle, entity);
+
+ if (bfqq)
+ list_del(&bfqq->bfqq_list);
+}
+
+/**
+ * bfq_insert - generic tree insertion.
+ * @root: tree root.
+ * @entity: entity to insert.
+ *
+ * This is used for the idle and the active tree, since they are both
+ * ordered by finish time.
+ */
+static void bfq_insert(struct rb_root *root, struct bfq_entity *entity)
+{
+ struct bfq_entity *entry;
+ struct rb_node **node = &root->rb_node;
+ struct rb_node *parent = NULL;
+
+ while (*node) {
+ parent = *node;
+ entry = rb_entry(parent, struct bfq_entity, rb_node);
+
+ if (bfq_gt(entry->finish, entity->finish))
+ node = &parent->rb_left;
+ else
+ node = &parent->rb_right;
+ }
+
+ rb_link_node(&entity->rb_node, parent, node);
+ rb_insert_color(&entity->rb_node, root);
+
+ entity->tree = root;
+}
+
+/**
+ * bfq_update_min - update the min_start field of a entity.
+ * @entity: the entity to update.
+ * @node: one of its children.
+ *
+ * This function is called when @entity may store an invalid value for
+ * min_start due to updates to the active tree. The function assumes
+ * that the subtree rooted at @node (which may be its left or its right
+ * child) has a valid min_start value.
+ */
+static void bfq_update_min(struct bfq_entity *entity, struct rb_node *node)
+{
+ struct bfq_entity *child;
+
+ if (node) {
+ child = rb_entry(node, struct bfq_entity, rb_node);
+ if (bfq_gt(entity->min_start, child->min_start))
+ entity->min_start = child->min_start;
+ }
+}
+
+/**
+ * bfq_update_active_node - recalculate min_start.
+ * @node: the node to update.
+ *
+ * @node may have changed position or one of its children may have moved,
+ * this function updates its min_start value. The left and right subtrees
+ * are assumed to hold a correct min_start value.
+ */
+static void bfq_update_active_node(struct rb_node *node)
+{
+ struct bfq_entity *entity = rb_entry(node, struct bfq_entity, rb_node);
+
+ entity->min_start = entity->start;
+ bfq_update_min(entity, node->rb_right);
+ bfq_update_min(entity, node->rb_left);
+}
+
+/**
+ * bfq_update_active_tree - update min_start for the whole active tree.
+ * @node: the starting node.
+ *
+ * @node must be the deepest modified node after an update. This function
+ * updates its min_start using the values held by its children, assuming
+ * that they did not change, and then updates all the nodes that may have
+ * changed in the path to the root. The only nodes that may have changed
+ * are the ones in the path or their siblings.
+ */
+static void bfq_update_active_tree(struct rb_node *node)
+{
+ struct rb_node *parent;
+
+up:
+ bfq_update_active_node(node);
+
+ parent = rb_parent(node);
+ if (!parent)
+ return;
+
+ if (node == parent->rb_left && parent->rb_right)
+ bfq_update_active_node(parent->rb_right);
+ else if (parent->rb_left)
+ bfq_update_active_node(parent->rb_left);
+
+ node = parent;
+ goto up;
+}
+
+/**
+ * bfq_active_insert - insert an entity in the active tree of its
+ * group/device.
+ * @st: the service tree of the entity.
+ * @entity: the entity being inserted.
+ *
+ * The active tree is ordered by finish time, but an extra key is kept
+ * per each node, containing the minimum value for the start times of
+ * its children (and the node itself), so it's possible to search for
+ * the eligible node with the lowest finish time in logarithmic time.
+ */
+static void bfq_active_insert(struct bfq_service_tree *st,
+ struct bfq_entity *entity)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+ struct rb_node *node = &entity->rb_node;
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ struct bfq_sched_data *sd = NULL;
+ struct bfq_group *bfqg = NULL;
+ struct bfq_data *bfqd = NULL;
+#endif
+
+ bfq_insert(&st->active, entity);
+
+ if (node->rb_left)
+ node = node->rb_left;
+ else if (node->rb_right)
+ node = node->rb_right;
+
+ bfq_update_active_tree(node);
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ sd = entity->sched_data;
+ bfqg = container_of(sd, struct bfq_group, sched_data);
+ bfqd = (struct bfq_data *)bfqg->bfqd;
+#endif
+ if (bfqq)
+ list_add(&bfqq->bfqq_list, &bfqq->bfqd->active_list);
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ else /* bfq_group */
+ bfq_weights_tree_add(bfqd, entity, &bfqd->group_weights_tree);
+
+ if (bfqg != bfqd->root_group)
+ bfqg->active_entities++;
+#endif
+}
+
+/**
+ * bfq_ioprio_to_weight - calc a weight from an ioprio.
+ * @ioprio: the ioprio value to convert.
+ */
+unsigned short bfq_ioprio_to_weight(int ioprio)
+{
+ return (IOPRIO_BE_NR - ioprio) * BFQ_WEIGHT_CONVERSION_COEFF;
+}
+
+/**
+ * bfq_weight_to_ioprio - calc an ioprio from a weight.
+ * @weight: the weight value to convert.
+ *
+ * To preserve as much as possible the old only-ioprio user interface,
+ * 0 is used as an escape ioprio value for weights (numerically) equal or
+ * larger than IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF.
+ */
+static unsigned short bfq_weight_to_ioprio(int weight)
+{
+ return max_t(int, 0,
+ IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF - weight);
+}
+
+static void bfq_get_entity(struct bfq_entity *entity)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+
+ if (bfqq) {
+ bfqq->ref++;
+ bfq_log_bfqq(bfqq->bfqd, bfqq, "get_entity: %p %d",
+ bfqq, bfqq->ref);
+ }
+}
+
+/**
+ * bfq_find_deepest - find the deepest node that an extraction can modify.
+ * @node: the node being removed.
+ *
+ * Do the first step of an extraction in an rb tree, looking for the
+ * node that will replace @node, and returning the deepest node that
+ * the following modifications to the tree can touch. If @node is the
+ * last node in the tree return %NULL.
+ */
+static struct rb_node *bfq_find_deepest(struct rb_node *node)
+{
+ struct rb_node *deepest;
+
+ if (!node->rb_right && !node->rb_left)
+ deepest = rb_parent(node);
+ else if (!node->rb_right)
+ deepest = node->rb_left;
+ else if (!node->rb_left)
+ deepest = node->rb_right;
+ else {
+ deepest = rb_next(node);
+ if (deepest->rb_right)
+ deepest = deepest->rb_right;
+ else if (rb_parent(deepest) != node)
+ deepest = rb_parent(deepest);
+ }
+
+ return deepest;
+}
+
+/**
+ * bfq_active_extract - remove an entity from the active tree.
+ * @st: the service_tree containing the tree.
+ * @entity: the entity being removed.
+ */
+static void bfq_active_extract(struct bfq_service_tree *st,
+ struct bfq_entity *entity)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+ struct rb_node *node;
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ struct bfq_sched_data *sd = NULL;
+ struct bfq_group *bfqg = NULL;
+ struct bfq_data *bfqd = NULL;
+#endif
+
+ node = bfq_find_deepest(&entity->rb_node);
+ bfq_extract(&st->active, entity);
+
+ if (node)
+ bfq_update_active_tree(node);
+
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ sd = entity->sched_data;
+ bfqg = container_of(sd, struct bfq_group, sched_data);
+ bfqd = (struct bfq_data *)bfqg->bfqd;
+#endif
+ if (bfqq)
+ list_del(&bfqq->bfqq_list);
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ else /* bfq_group */
+ bfq_weights_tree_remove(bfqd, entity,
+ &bfqd->group_weights_tree);
+
+ if (bfqg != bfqd->root_group)
+ bfqg->active_entities--;
+#endif
+}
+
+/**
+ * bfq_idle_insert - insert an entity into the idle tree.
+ * @st: the service tree containing the tree.
+ * @entity: the entity to insert.
+ */
+static void bfq_idle_insert(struct bfq_service_tree *st,
+ struct bfq_entity *entity)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+ struct bfq_entity *first_idle = st->first_idle;
+ struct bfq_entity *last_idle = st->last_idle;
+
+ if (!first_idle || bfq_gt(first_idle->finish, entity->finish))
+ st->first_idle = entity;
+ if (!last_idle || bfq_gt(entity->finish, last_idle->finish))
+ st->last_idle = entity;
+
+ bfq_insert(&st->idle, entity);
+
+ if (bfqq)
+ list_add(&bfqq->bfqq_list, &bfqq->bfqd->idle_list);
+}
+
+/**
+ * bfq_forget_entity - do not consider entity any longer for scheduling
+ * @st: the service tree.
+ * @entity: the entity being removed.
+ * @is_in_service: true if entity is currently the in-service entity.
+ *
+ * Forget everything about @entity. In addition, if entity represents
+ * a queue, and the latter is not in service, then release the service
+ * reference to the queue (the one taken through bfq_get_entity). In
+ * fact, in this case, there is really no more service reference to
+ * the queue, as the latter is also outside any service tree. If,
+ * instead, the queue is in service, then __bfq_bfqd_reset_in_service
+ * will take care of putting the reference when the queue finally
+ * stops being served.
+ */
+static void bfq_forget_entity(struct bfq_service_tree *st,
+ struct bfq_entity *entity,
+ bool is_in_service)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+
+ entity->on_st = false;
+ st->wsum -= entity->weight;
+ if (bfqq && !is_in_service)
+ bfq_put_queue(bfqq);
+}
+
+/**
+ * bfq_put_idle_entity - release the idle tree ref of an entity.
+ * @st: service tree for the entity.
+ * @entity: the entity being released.
+ */
+void bfq_put_idle_entity(struct bfq_service_tree *st, struct bfq_entity *entity)
+{
+ bfq_idle_extract(st, entity);
+ bfq_forget_entity(st, entity,
+ entity == entity->sched_data->in_service_entity);
+}
+
+/**
+ * bfq_forget_idle - update the idle tree if necessary.
+ * @st: the service tree to act upon.
+ *
+ * To preserve the global O(log N) complexity we only remove one entry here;
+ * as the idle tree will not grow indefinitely this can be done safely.
+ */
+static void bfq_forget_idle(struct bfq_service_tree *st)
+{
+ struct bfq_entity *first_idle = st->first_idle;
+ struct bfq_entity *last_idle = st->last_idle;
+
+ if (RB_EMPTY_ROOT(&st->active) && last_idle &&
+ !bfq_gt(last_idle->finish, st->vtime)) {
+ /*
+ * Forget the whole idle tree, increasing the vtime past
+ * the last finish time of idle entities.
+ */
+ st->vtime = last_idle->finish;
+ }
+
+ if (first_idle && !bfq_gt(first_idle->finish, st->vtime))
+ bfq_put_idle_entity(st, first_idle);
+}
+
+struct bfq_service_tree *bfq_entity_service_tree(struct bfq_entity *entity)
+{
+ struct bfq_sched_data *sched_data = entity->sched_data;
+ unsigned int idx = bfq_class_idx(entity);
+
+ return sched_data->service_tree + idx;
+}
+
+/*
+ * Update weight and priority of entity. If update_class_too is true,
+ * then update the ioprio_class of entity too.
+ *
+ * The reason why the update of ioprio_class is controlled through the
+ * last parameter is as follows. Changing the ioprio class of an
+ * entity implies changing the destination service trees for that
+ * entity. If such a change occurred when the entity is already on one
+ * of the service trees for its previous class, then the state of the
+ * entity would become more complex: none of the new possible service
+ * trees for the entity, according to bfq_entity_service_tree(), would
+ * match any of the possible service trees on which the entity
+ * is. Complex operations involving these trees, such as entity
+ * activations and deactivations, should take into account this
+ * additional complexity. To avoid this issue, this function is
+ * invoked with update_class_too unset in the points in the code where
+ * entity may happen to be on some tree.
+ */
+struct bfq_service_tree *
+__bfq_entity_update_weight_prio(struct bfq_service_tree *old_st,
+ struct bfq_entity *entity,
+ bool update_class_too)
+{
+ struct bfq_service_tree *new_st = old_st;
+
+ if (entity->prio_changed) {
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+ unsigned int prev_weight, new_weight;
+ struct bfq_data *bfqd = NULL;
+ struct rb_root *root;
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ struct bfq_sched_data *sd;
+ struct bfq_group *bfqg;
+#endif
+
+ if (bfqq)
+ bfqd = bfqq->bfqd;
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
+ else {
+ sd = entity->my_sched_data;
+ bfqg = container_of(sd, struct bfq_group, sched_data);
+ bfqd = (struct bfq_data *)bfqg->bfqd;
+ }
+#endif
+
+ old_st->wsum -= entity->weight;
+
+ if (entity->new_weight != entity->orig_weight) {
+ if (entity->new_weight < BFQ_MIN_WEIGHT ||
+ entity->new_weight > BFQ_MAX_WEIGHT) {
+ pr_crit("update_weight_prio: new_weight %d\n",
+ entity->new_weight);
+ if (entity->new_weight < BFQ_MIN_WEIGHT)
+ entity->new_weight = BFQ_MIN_WEIGHT;
+ else
+ entity->new_weight = BFQ_MAX_WEIGHT;
+ }
+ entity->orig_weight = entity->new_weight;
+ if (bfqq)
+ bfqq->ioprio =
+ bfq_weight_to_ioprio(entity->orig_weight);
+ }
+
+ if (bfqq && update_class_too)
+ bfqq->ioprio_class = bfqq->new_ioprio_class;
+
+ /*
+ * Reset prio_changed only if the ioprio_class change
+ * is not pending any longer.
+ */
+ if (!bfqq || bfqq->ioprio_class == bfqq->new_ioprio_class)
+ entity->prio_changed = 0;
+
+ /*
+ * NOTE: here we may be changing the weight too early,
+ * this will cause unfairness. The correct approach
+ * would have required additional complexity to defer
+ * weight changes to the proper time instants (i.e.,
+ * when entity->finish <= old_st->vtime).
+ */
+ new_st = bfq_entity_service_tree(entity);
+
+ prev_weight = entity->weight;
+ new_weight = entity->orig_weight *
+ (bfqq ? bfqq->wr_coeff : 1);
+ /*
+ * If the weight of the entity changes, remove the entity
+ * from its old weight counter (if there is a counter
+ * associated with the entity), and add it to the counter
+ * associated with its new weight.
+ */
+ if (prev_weight != new_weight) {
+ root = bfqq ? &bfqd->queue_weights_tree :
+ &bfqd->group_weights_tree;
+ bfq_weights_tree_remove(bfqd, entity, root);
+ }
+ entity->weight = new_weight;
+ /*
+ * Add the entity to its weights tree only if it is
+ * not associated with a weight-raised queue.
+ */
+ if (prev_weight != new_weight &&
+ (bfqq ? bfqq->wr_coeff == 1 : 1))
+ /* If we get here, root has been initialized. */
+ bfq_weights_tree_add(bfqd, entity, root);
+
+ new_st->wsum += entity->weight;
+
+ if (new_st != old_st)
+ entity->start = new_st->vtime;
+ }
+
+ return new_st;
+}
+
+/**
+ * bfq_bfqq_served - update the scheduler status after selection for
+ * service.
+ * @bfqq: the queue being served.
+ * @served: bytes to transfer.
+ *
+ * NOTE: this can be optimized, as the timestamps of upper level entities
+ * are synchronized every time a new bfqq is selected for service. By now,
+ * we keep it to better check consistency.
+ */
+void bfq_bfqq_served(struct bfq_queue *bfqq, int served)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+ struct bfq_service_tree *st;
+
+ for_each_entity(entity) {
+ st = bfq_entity_service_tree(entity);
+
+ entity->service += served;
+
+ st->vtime += bfq_delta(served, st->wsum);
+ bfq_forget_idle(st);
+ }
+ bfqg_stats_set_start_empty_time(bfqq_group(bfqq));
+ bfq_log_bfqq(bfqq->bfqd, bfqq, "bfqq_served %d secs", served);
+}
+
+/**
+ * bfq_bfqq_charge_time - charge an amount of service equivalent to the length
+ * of the time interval during which bfqq has been in
+ * service.
+ * @bfqd: the device
+ * @bfqq: the queue that needs a service update.
+ * @time_ms: the amount of time during which the queue has received service
+ *
+ * If a queue does not consume its budget fast enough, then providing
+ * the queue with service fairness may impair throughput, more or less
+ * severely. For this reason, queues that consume their budget slowly
+ * are provided with time fairness instead of service fairness. This
+ * goal is achieved through the BFQ scheduling engine, even if such an
+ * engine works in the service, and not in the time domain. The trick
+ * is charging these queues with an inflated amount of service, equal
+ * to the amount of service that they would have received during their
+ * service slot if they had been fast, i.e., if their requests had
+ * been dispatched at a rate equal to the estimated peak rate.
+ *
+ * It is worth noting that time fairness can cause important
+ * distortions in terms of bandwidth distribution, on devices with
+ * internal queueing. The reason is that I/O requests dispatched
+ * during the service slot of a queue may be served after that service
+ * slot is finished, and may have a total processing time loosely
+ * correlated with the duration of the service slot. This is
+ * especially true for short service slots.
+ */
+void bfq_bfqq_charge_time(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ unsigned long time_ms)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+ int tot_serv_to_charge = entity->service;
+ unsigned int timeout_ms = jiffies_to_msecs(bfq_timeout);
+
+ if (time_ms > 0 && time_ms < timeout_ms)
+ tot_serv_to_charge =
+ (bfqd->bfq_max_budget * time_ms) / timeout_ms;
+
+ if (tot_serv_to_charge < entity->service)
+ tot_serv_to_charge = entity->service;
+
+ /* Increase budget to avoid inconsistencies */
+ if (tot_serv_to_charge > entity->budget)
+ entity->budget = tot_serv_to_charge;
+
+ bfq_bfqq_served(bfqq,
+ max_t(int, 0, tot_serv_to_charge - entity->service));
+}
+
+static void bfq_update_fin_time_enqueue(struct bfq_entity *entity,
+ struct bfq_service_tree *st,
+ bool backshifted)
+{
+ struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
+
+ /*
+ * When this function is invoked, entity is not in any service
+ * tree, then it is safe to invoke next function with the last
+ * parameter set (see the comments on the function).
+ */
+ st = __bfq_entity_update_weight_prio(st, entity, true);
+ bfq_calc_finish(entity, entity->budget);
+
+ /*
+ * If some queues enjoy backshifting for a while, then their
+ * (virtual) finish timestamps may happen to become lower and
+ * lower than the system virtual time. In particular, if
+ * these queues often happen to be idle for short time
+ * periods, and during such time periods other queues with
+ * higher timestamps happen to be busy, then the backshifted
+ * timestamps of the former queues can become much lower than
+ * the system virtual time. In fact, to serve the queues with
+ * higher timestamps while the ones with lower timestamps are
+ * idle, the system virtual time may be pushed-up to much
+ * higher values than the finish timestamps of the idle
+ * queues. As a consequence, the finish timestamps of all new
+ * or newly activated queues may end up being much larger than
+ * those of lucky queues with backshifted timestamps. The
+ * latter queues may then monopolize the device for a lot of
+ * time. This would simply break service guarantees.
+ *
+ * To reduce this problem, push up a little bit the
+ * backshifted timestamps of the queue associated with this
+ * entity (only a queue can happen to have the backshifted
+ * flag set): just enough to let the finish timestamp of the
+ * queue be equal to the current value of the system virtual
+ * time. This may introduce a little unfairness among queues
+ * with backshifted timestamps, but it does not break
+ * worst-case fairness guarantees.
+ *
+ * As a special case, if bfqq is weight-raised, push up
+ * timestamps much less, to keep very low the probability that
+ * this push up causes the backshifted finish timestamps of
+ * weight-raised queues to become higher than the backshifted
+ * finish timestamps of non weight-raised queues.
+ */
+ if (backshifted && bfq_gt(st->vtime, entity->finish)) {
+ unsigned long delta = st->vtime - entity->finish;
+
+ if (bfqq)
+ delta /= bfqq->wr_coeff;
+
+ entity->start += delta;
+ entity->finish += delta;
+ }
+
+ bfq_active_insert(st, entity);
+}
+
+/**
+ * __bfq_activate_entity - handle activation of entity.
+ * @entity: the entity being activated.
+ * @non_blocking_wait_rq: true if entity was waiting for a request
+ *
+ * Called for a 'true' activation, i.e., if entity is not active and
+ * one of its children receives a new request.
+ *
+ * Basically, this function updates the timestamps of entity and
+ * inserts entity into its active tree, ater possibly extracting it
+ * from its idle tree.
+ */
+static void __bfq_activate_entity(struct bfq_entity *entity,
+ bool non_blocking_wait_rq)
+{
+ struct bfq_service_tree *st = bfq_entity_service_tree(entity);
+ bool backshifted = false;
+ unsigned long long min_vstart;
+
+ /* See comments on bfq_fqq_update_budg_for_activation */
+ if (non_blocking_wait_rq && bfq_gt(st->vtime, entity->finish)) {
+ backshifted = true;
+ min_vstart = entity->finish;
+ } else
+ min_vstart = st->vtime;
+
+ if (entity->tree == &st->idle) {
+ /*
+ * Must be on the idle tree, bfq_idle_extract() will
+ * check for that.
+ */
+ bfq_idle_extract(st, entity);
+ entity->start = bfq_gt(min_vstart, entity->finish) ?
+ min_vstart : entity->finish;
+ } else {
+ /*
+ * The finish time of the entity may be invalid, and
+ * it is in the past for sure, otherwise the queue
+ * would have been on the idle tree.
+ */
+ entity->start = min_vstart;
+ st->wsum += entity->weight;
+ /*
+ * entity is about to be inserted into a service tree,
+ * and then set in service: get a reference to make
+ * sure entity does not disappear until it is no
+ * longer in service or scheduled for service.
+ */
+ bfq_get_entity(entity);
+
+ entity->on_st = true;
+ }
+
+ bfq_update_fin_time_enqueue(entity, st, backshifted);
+}
+
+/**
+ * __bfq_requeue_entity - handle requeueing or repositioning of an entity.
+ * @entity: the entity being requeued or repositioned.
+ *
+ * Requeueing is needed if this entity stops being served, which
+ * happens if a leaf descendant entity has expired. On the other hand,
+ * repositioning is needed if the next_inservice_entity for the child
+ * entity has changed. See the comments inside the function for
+ * details.
+ *
+ * Basically, this function: 1) removes entity from its active tree if
+ * present there, 2) updates the timestamps of entity and 3) inserts
+ * entity back into its active tree (in the new, right position for
+ * the new values of the timestamps).
+ */
+static void __bfq_requeue_entity(struct bfq_entity *entity)
+{
+ struct bfq_sched_data *sd = entity->sched_data;
+ struct bfq_service_tree *st = bfq_entity_service_tree(entity);
+
+ if (entity == sd->in_service_entity) {
+ /*
+ * We are requeueing the current in-service entity,
+ * which may have to be done for one of the following
+ * reasons:
+ * - entity represents the in-service queue, and the
+ * in-service queue is being requeued after an
+ * expiration;
+ * - entity represents a group, and its budget has
+ * changed because one of its child entities has
+ * just been either activated or requeued for some
+ * reason; the timestamps of the entity need then to
+ * be updated, and the entity needs to be enqueued
+ * or repositioned accordingly.
+ *
+ * In particular, before requeueing, the start time of
+ * the entity must be moved forward to account for the
+ * service that the entity has received while in
+ * service. This is done by the next instructions. The
+ * finish time will then be updated according to this
+ * new value of the start time, and to the budget of
+ * the entity.
+ */
+ bfq_calc_finish(entity, entity->service);
+ entity->start = entity->finish;
+ /*
+ * In addition, if the entity had more than one child
+ * when set in service, then it was not extracted from
+ * the active tree. This implies that the position of
+ * the entity in the active tree may need to be
+ * changed now, because we have just updated the start
+ * time of the entity, and we will update its finish
+ * time in a moment (the requeueing is then, more
+ * precisely, a repositioning in this case). To
+ * implement this repositioning, we: 1) dequeue the
+ * entity here, 2) update the finish time and requeue
+ * the entity according to the new timestamps below.
+ */
+ if (entity->tree)
+ bfq_active_extract(st, entity);
+ } else { /* The entity is already active, and not in service */
+ /*
+ * In this case, this function gets called only if the
+ * next_in_service entity below this entity has
+ * changed, and this change has caused the budget of
+ * this entity to change, which, finally implies that
+ * the finish time of this entity must be
+ * updated. Such an update may cause the scheduling,
+ * i.e., the position in the active tree, of this
+ * entity to change. We handle this change by: 1)
+ * dequeueing the entity here, 2) updating the finish
+ * time and requeueing the entity according to the new
+ * timestamps below. This is the same approach as the
+ * non-extracted-entity sub-case above.
+ */
+ bfq_active_extract(st, entity);
+ }
+
+ bfq_update_fin_time_enqueue(entity, st, false);
+}
+
+static void __bfq_activate_requeue_entity(struct bfq_entity *entity,
+ struct bfq_sched_data *sd,
+ bool non_blocking_wait_rq)
+{
+ struct bfq_service_tree *st = bfq_entity_service_tree(entity);
+
+ if (sd->in_service_entity == entity || entity->tree == &st->active)
+ /*
+ * in service or already queued on the active tree,
+ * requeue or reposition
+ */
+ __bfq_requeue_entity(entity);
+ else
+ /*
+ * Not in service and not queued on its active tree:
+ * the activity is idle and this is a true activation.
+ */
+ __bfq_activate_entity(entity, non_blocking_wait_rq);
+}
+
+
+/**
+ * bfq_activate_requeue_entity - activate or requeue an entity representing a
+ * bfq_queue, and activate, requeue or reposition
+ * all ancestors for which such an update becomes
+ * necessary.
+ * @entity: the entity to activate.
+ * @non_blocking_wait_rq: true if this entity was waiting for a request
+ * @requeue: true if this is a requeue, which implies that bfqq is
+ * being expired; thus ALL its ancestors stop being served and must
+ * therefore be requeued
+ * @expiration: true if this function is being invoked in the expiration path
+ * of the in-service queue
+ */
+static void bfq_activate_requeue_entity(struct bfq_entity *entity,
+ bool non_blocking_wait_rq,
+ bool requeue, bool expiration)
+{
+ struct bfq_sched_data *sd;
+
+ for_each_entity(entity) {
+ sd = entity->sched_data;
+ __bfq_activate_requeue_entity(entity, sd, non_blocking_wait_rq);
+
+ if (!bfq_update_next_in_service(sd, entity, expiration) &&
+ !requeue)
+ break;
+ }
+}
+
+/**
+ * __bfq_deactivate_entity - deactivate an entity from its service tree.
+ * @entity: the entity to deactivate.
+ * @ins_into_idle_tree: if false, the entity will not be put into the
+ * idle tree.
+ *
+ * Deactivates an entity, independently of its previous state. Must
+ * be invoked only if entity is on a service tree. Extracts the entity
+ * from that tree, and if necessary and allowed, puts it into the idle
+ * tree.
+ */
+bool __bfq_deactivate_entity(struct bfq_entity *entity, bool ins_into_idle_tree)
+{
+ struct bfq_sched_data *sd = entity->sched_data;
+ struct bfq_service_tree *st;
+ bool is_in_service;
+
+ if (!entity->on_st) /* entity never activated, or already inactive */
+ return false;
+
+ /*
+ * If we get here, then entity is active, which implies that
+ * bfq_group_set_parent has already been invoked for the group
+ * represented by entity. Therefore, the field
+ * entity->sched_data has been set, and we can safely use it.
+ */
+ st = bfq_entity_service_tree(entity);
+ is_in_service = entity == sd->in_service_entity;
+
+ bfq_calc_finish(entity, entity->service);
+
+ if (is_in_service)
+ sd->in_service_entity = NULL;
+ else
+ /*
+ * Non in-service entity: nobody will take care of
+ * resetting its service counter on expiration. Do it
+ * now.
+ */
+ entity->service = 0;
+
+ if (entity->tree == &st->active)
+ bfq_active_extract(st, entity);
+ else if (!is_in_service && entity->tree == &st->idle)
+ bfq_idle_extract(st, entity);
+
+ if (!ins_into_idle_tree || !bfq_gt(entity->finish, st->vtime))
+ bfq_forget_entity(st, entity, is_in_service);
+ else
+ bfq_idle_insert(st, entity);
+
+ return true;
+}
+
+/**
+ * bfq_deactivate_entity - deactivate an entity representing a bfq_queue.
+ * @entity: the entity to deactivate.
+ * @ins_into_idle_tree: true if the entity can be put into the idle tree
+ * @expiration: true if this function is being invoked in the expiration path
+ * of the in-service queue
+ */
+static void bfq_deactivate_entity(struct bfq_entity *entity,
+ bool ins_into_idle_tree,
+ bool expiration)
+{
+ struct bfq_sched_data *sd;
+ struct bfq_entity *parent = NULL;
+
+ for_each_entity_safe(entity, parent) {
+ sd = entity->sched_data;
+
+ if (!__bfq_deactivate_entity(entity, ins_into_idle_tree)) {
+ /*
+ * entity is not in any tree any more, so
+ * this deactivation is a no-op, and there is
+ * nothing to change for upper-level entities
+ * (in case of expiration, this can never
+ * happen).
+ */
+ return;
+ }
+
+ if (sd->next_in_service == entity)
+ /*
+ * entity was the next_in_service entity,
+ * then, since entity has just been
+ * deactivated, a new one must be found.
+ */
+ bfq_update_next_in_service(sd, NULL, expiration);
+
+ if (sd->next_in_service || sd->in_service_entity) {
+ /*
+ * The parent entity is still active, because
+ * either next_in_service or in_service_entity
+ * is not NULL. So, no further upwards
+ * deactivation must be performed. Yet,
+ * next_in_service has changed. Then the
+ * schedule does need to be updated upwards.
+ *
+ * NOTE If in_service_entity is not NULL, then
+ * next_in_service may happen to be NULL,
+ * although the parent entity is evidently
+ * active. This happens if 1) the entity
+ * pointed by in_service_entity is the only
+ * active entity in the parent entity, and 2)
+ * according to the definition of
+ * next_in_service, the in_service_entity
+ * cannot be considered as
+ * next_in_service. See the comments on the
+ * definition of next_in_service for details.
+ */
+ break;
+ }
+
+ /*
+ * If we get here, then the parent is no more
+ * backlogged and we need to propagate the
+ * deactivation upwards. Thus let the loop go on.
+ */
+
+ /*
+ * Also let parent be queued into the idle tree on
+ * deactivation, to preserve service guarantees, and
+ * assuming that who invoked this function does not
+ * need parent entities too to be removed completely.
+ */
+ ins_into_idle_tree = true;
+ }
+
+ /*
+ * If the deactivation loop is fully executed, then there are
+ * no more entities to touch and next loop is not executed at
+ * all. Otherwise, requeue remaining entities if they are
+ * about to stop receiving service, or reposition them if this
+ * is not the case.
+ */
+ entity = parent;
+ for_each_entity(entity) {
+ /*
+ * Invoke __bfq_requeue_entity on entity, even if
+ * already active, to requeue/reposition it in the
+ * active tree (because sd->next_in_service has
+ * changed)
+ */
+ __bfq_requeue_entity(entity);
+
+ sd = entity->sched_data;
+ if (!bfq_update_next_in_service(sd, entity, expiration) &&
+ !expiration)
+ /*
+ * next_in_service unchanged or not causing
+ * any change in entity->parent->sd, and no
+ * requeueing needed for expiration: stop
+ * here.
+ */
+ break;
+ }
+}
+
+/**
+ * bfq_calc_vtime_jump - compute the value to which the vtime should jump,
+ * if needed, to have at least one entity eligible.
+ * @st: the service tree to act upon.
+ *
+ * Assumes that st is not empty.
+ */
+static u64 bfq_calc_vtime_jump(struct bfq_service_tree *st)
+{
+ struct bfq_entity *root_entity = bfq_root_active_entity(&st->active);
+
+ if (bfq_gt(root_entity->min_start, st->vtime))
+ return root_entity->min_start;
+
+ return st->vtime;
+}
+
+static void bfq_update_vtime(struct bfq_service_tree *st, u64 new_value)
+{
+ if (new_value > st->vtime) {
+ st->vtime = new_value;
+ bfq_forget_idle(st);
+ }
+}
+
+/**
+ * bfq_first_active_entity - find the eligible entity with
+ * the smallest finish time
+ * @st: the service tree to select from.
+ * @vtime: the system virtual to use as a reference for eligibility
+ *
+ * This function searches the first schedulable entity, starting from the
+ * root of the tree and going on the left every time on this side there is
+ * a subtree with at least one eligible (start <= vtime) entity. The path on
+ * the right is followed only if a) the left subtree contains no eligible
+ * entities and b) no eligible entity has been found yet.
+ */
+static struct bfq_entity *bfq_first_active_entity(struct bfq_service_tree *st,
+ u64 vtime)
+{
+ struct bfq_entity *entry, *first = NULL;
+ struct rb_node *node = st->active.rb_node;
+
+ while (node) {
+ entry = rb_entry(node, struct bfq_entity, rb_node);
+left:
+ if (!bfq_gt(entry->start, vtime))
+ first = entry;
+
+ if (node->rb_left) {
+ entry = rb_entry(node->rb_left,
+ struct bfq_entity, rb_node);
+ if (!bfq_gt(entry->min_start, vtime)) {
+ node = node->rb_left;
+ goto left;
+ }
+ }
+ if (first)
+ break;
+ node = node->rb_right;
+ }
+
+ return first;
+}
+
+/**
+ * __bfq_lookup_next_entity - return the first eligible entity in @st.
+ * @st: the service tree.
+ *
+ * If there is no in-service entity for the sched_data st belongs to,
+ * then return the entity that will be set in service if:
+ * 1) the parent entity this st belongs to is set in service;
+ * 2) no entity belonging to such parent entity undergoes a state change
+ * that would influence the timestamps of the entity (e.g., becomes idle,
+ * becomes backlogged, changes its budget, ...).
+ *
+ * In this first case, update the virtual time in @st too (see the
+ * comments on this update inside the function).
+ *
+ * In constrast, if there is an in-service entity, then return the
+ * entity that would be set in service if not only the above
+ * conditions, but also the next one held true: the currently
+ * in-service entity, on expiration,
+ * 1) gets a finish time equal to the current one, or
+ * 2) is not eligible any more, or
+ * 3) is idle.
+ */
+static struct bfq_entity *
+__bfq_lookup_next_entity(struct bfq_service_tree *st, bool in_service)
+{
+ struct bfq_entity *entity;
+ u64 new_vtime;
+
+ if (RB_EMPTY_ROOT(&st->active))
+ return NULL;
+
+ /*
+ * Get the value of the system virtual time for which at
+ * least one entity is eligible.
+ */
+ new_vtime = bfq_calc_vtime_jump(st);
+
+ /*
+ * If there is no in-service entity for the sched_data this
+ * active tree belongs to, then push the system virtual time
+ * up to the value that guarantees that at least one entity is
+ * eligible. If, instead, there is an in-service entity, then
+ * do not make any such update, because there is already an
+ * eligible entity, namely the in-service one (even if the
+ * entity is not on st, because it was extracted when set in
+ * service).
+ */
+ if (!in_service)
+ bfq_update_vtime(st, new_vtime);
+
+ entity = bfq_first_active_entity(st, new_vtime);
+
+ return entity;
+}
+
+/**
+ * bfq_lookup_next_entity - return the first eligible entity in @sd.
+ * @sd: the sched_data.
+ * @expiration: true if we are on the expiration path of the in-service queue
+ *
+ * This function is invoked when there has been a change in the trees
+ * for sd, and we need to know what is the new next entity to serve
+ * after this change.
+ */
+static struct bfq_entity *bfq_lookup_next_entity(struct bfq_sched_data *sd,
+ bool expiration)
+{
+ struct bfq_service_tree *st = sd->service_tree;
+ struct bfq_service_tree *idle_class_st = st + (BFQ_IOPRIO_CLASSES - 1);
+ struct bfq_entity *entity = NULL;
+ int class_idx = 0;
+
+ /*
+ * Choose from idle class, if needed to guarantee a minimum
+ * bandwidth to this class (and if there is some active entity
+ * in idle class). This should also mitigate
+ * priority-inversion problems in case a low priority task is
+ * holding file system resources.
+ */
+ if (time_is_before_jiffies(sd->bfq_class_idle_last_service +
+ BFQ_CL_IDLE_TIMEOUT)) {
+ if (!RB_EMPTY_ROOT(&idle_class_st->active))
+ class_idx = BFQ_IOPRIO_CLASSES - 1;
+ /* About to be served if backlogged, or not yet backlogged */
+ sd->bfq_class_idle_last_service = jiffies;
+ }
+
+ /*
+ * Find the next entity to serve for the highest-priority
+ * class, unless the idle class needs to be served.
+ */
+ for (; class_idx < BFQ_IOPRIO_CLASSES; class_idx++) {
+ /*
+ * If expiration is true, then bfq_lookup_next_entity
+ * is being invoked as a part of the expiration path
+ * of the in-service queue. In this case, even if
+ * sd->in_service_entity is not NULL,
+ * sd->in_service_entiy at this point is actually not
+ * in service any more, and, if needed, has already
+ * been properly queued or requeued into the right
+ * tree. The reason why sd->in_service_entity is still
+ * not NULL here, even if expiration is true, is that
+ * sd->in_service_entiy is reset as a last step in the
+ * expiration path. So, if expiration is true, tell
+ * __bfq_lookup_next_entity that there is no
+ * sd->in_service_entity.
+ */
+ entity = __bfq_lookup_next_entity(st + class_idx,
+ sd->in_service_entity &&
+ !expiration);
+
+ if (entity)
+ break;
+ }
+
+ if (!entity)
+ return NULL;
+
+ return entity;
+}
+
+bool next_queue_may_preempt(struct bfq_data *bfqd)
+{
+ struct bfq_sched_data *sd = &bfqd->root_group->sched_data;
+
+ return sd->next_in_service != sd->in_service_entity;
+}
+
+/*
+ * Get next queue for service.
+ */
+struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd)
+{
+ struct bfq_entity *entity = NULL;
+ struct bfq_sched_data *sd;
+ struct bfq_queue *bfqq;
+
+ if (bfqd->busy_queues == 0)
+ return NULL;
+
+ /*
+ * Traverse the path from the root to the leaf entity to
+ * serve. Set in service all the entities visited along the
+ * way.
+ */
+ sd = &bfqd->root_group->sched_data;
+ for (; sd ; sd = entity->my_sched_data) {
+ /*
+ * WARNING. We are about to set the in-service entity
+ * to sd->next_in_service, i.e., to the (cached) value
+ * returned by bfq_lookup_next_entity(sd) the last
+ * time it was invoked, i.e., the last time when the
+ * service order in sd changed as a consequence of the
+ * activation or deactivation of an entity. In this
+ * respect, if we execute bfq_lookup_next_entity(sd)
+ * in this very moment, it may, although with low
+ * probability, yield a different entity than that
+ * pointed to by sd->next_in_service. This rare event
+ * happens in case there was no CLASS_IDLE entity to
+ * serve for sd when bfq_lookup_next_entity(sd) was
+ * invoked for the last time, while there is now one
+ * such entity.
+ *
+ * If the above event happens, then the scheduling of
+ * such entity in CLASS_IDLE is postponed until the
+ * service of the sd->next_in_service entity
+ * finishes. In fact, when the latter is expired,
+ * bfq_lookup_next_entity(sd) gets called again,
+ * exactly to update sd->next_in_service.
+ */
+
+ /* Make next_in_service entity become in_service_entity */
+ entity = sd->next_in_service;
+ sd->in_service_entity = entity;
+
+ /*
+ * Reset the accumulator of the amount of service that
+ * the entity is about to receive.
+ */
+ entity->service = 0;
+
+ /*
+ * If entity is no longer a candidate for next
+ * service, then it must be extracted from its active
+ * tree, so as to make sure that it won't be
+ * considered when computing next_in_service. See the
+ * comments on the function
+ * bfq_no_longer_next_in_service() for details.
+ */
+ if (bfq_no_longer_next_in_service(entity))
+ bfq_active_extract(bfq_entity_service_tree(entity),
+ entity);
+
+ /*
+ * Even if entity is not to be extracted according to
+ * the above check, a descendant entity may get
+ * extracted in one of the next iterations of this
+ * loop. Such an event could cause a change in
+ * next_in_service for the level of the descendant
+ * entity, and thus possibly back to this level.
+ *
+ * However, we cannot perform the resulting needed
+ * update of next_in_service for this level before the
+ * end of the whole loop, because, to know which is
+ * the correct next-to-serve candidate entity for each
+ * level, we need first to find the leaf entity to set
+ * in service. In fact, only after we know which is
+ * the next-to-serve leaf entity, we can discover
+ * whether the parent entity of the leaf entity
+ * becomes the next-to-serve, and so on.
+ */
+ }
+
+ bfqq = bfq_entity_to_bfqq(entity);
+
+ /*
+ * We can finally update all next-to-serve entities along the
+ * path from the leaf entity just set in service to the root.
+ */
+ for_each_entity(entity) {
+ struct bfq_sched_data *sd = entity->sched_data;
+
+ if (!bfq_update_next_in_service(sd, NULL, false))
+ break;
+ }
+
+ return bfqq;
+}
+
+void __bfq_bfqd_reset_in_service(struct bfq_data *bfqd)
+{
+ struct bfq_queue *in_serv_bfqq = bfqd->in_service_queue;
+ struct bfq_entity *in_serv_entity = &in_serv_bfqq->entity;
+ struct bfq_entity *entity = in_serv_entity;
+
+ bfq_clear_bfqq_wait_request(in_serv_bfqq);
+ hrtimer_try_to_cancel(&bfqd->idle_slice_timer);
+ bfqd->in_service_queue = NULL;
+
+ /*
+ * When this function is called, all in-service entities have
+ * been properly deactivated or requeued, so we can safely
+ * execute the final step: reset in_service_entity along the
+ * path from entity to the root.
+ */
+ for_each_entity(entity)
+ entity->sched_data->in_service_entity = NULL;
+
+ /*
+ * in_serv_entity is no longer in service, so, if it is in no
+ * service tree either, then release the service reference to
+ * the queue it represents (taken with bfq_get_entity).
+ */
+ if (!in_serv_entity->on_st)
+ bfq_put_queue(in_serv_bfqq);
+}
+
+void bfq_deactivate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ bool ins_into_idle_tree, bool expiration)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+
+ bfq_deactivate_entity(entity, ins_into_idle_tree, expiration);
+}
+
+void bfq_activate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+
+ bfq_activate_requeue_entity(entity, bfq_bfqq_non_blocking_wait_rq(bfqq),
+ false, false);
+ bfq_clear_bfqq_non_blocking_wait_rq(bfqq);
+}
+
+void bfq_requeue_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ bool expiration)
+{
+ struct bfq_entity *entity = &bfqq->entity;
+
+ bfq_activate_requeue_entity(entity, false,
+ bfqq == bfqd->in_service_queue, expiration);
+}
+
+/*
+ * Called when the bfqq no longer has requests pending, remove it from
+ * the service tree. As a special case, it can be invoked during an
+ * expiration.
+ */
+void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ bool expiration)
+{
+ bfq_log_bfqq(bfqd, bfqq, "del from busy");
+
+ bfq_clear_bfqq_busy(bfqq);
+
+ bfqd->busy_queues--;
+
+ if (!bfqq->dispatched)
+ bfq_weights_tree_remove(bfqd, &bfqq->entity,
+ &bfqd->queue_weights_tree);
+
+ if (bfqq->wr_coeff > 1)
+ bfqd->wr_busy_queues--;
+
+ bfqg_stats_update_dequeue(bfqq_group(bfqq));
+
+ bfq_deactivate_bfqq(bfqd, bfqq, true, expiration);
+}
+
+/*
+ * Called when an inactive queue receives a new request.
+ */
+void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+{
+ bfq_log_bfqq(bfqd, bfqq, "add to busy");
+
+ bfq_activate_bfqq(bfqd, bfqq);
+
+ bfq_mark_bfqq_busy(bfqq);
+ bfqd->busy_queues++;
+
+ if (!bfqq->dispatched)
+ if (bfqq->wr_coeff == 1)
+ bfq_weights_tree_add(bfqd, &bfqq->entity,
+ &bfqd->queue_weights_tree);
+
+ if (bfqq->wr_coeff > 1)
+ bfqd->wr_busy_queues++;
+}
diff --git a/src/kernel/linux/v4.14/block/bio-integrity.c b/src/kernel/linux/v4.14/block/bio-integrity.c
new file mode 100644
index 0000000..d3df44c
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/bio-integrity.c
@@ -0,0 +1,514 @@
+/*
+ * bio-integrity.c - bio data integrity extensions
+ *
+ * Copyright (C) 2007, 2008, 2009 Oracle Corporation
+ * Written by: Martin K. Petersen <martin.petersen@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ */
+
+#include <linux/blkdev.h>
+#include <linux/mempool.h>
+#include <linux/export.h>
+#include <linux/bio.h>
+#include <linux/workqueue.h>
+#include <linux/slab.h>
+#include "blk.h"
+
+#define BIP_INLINE_VECS 4
+
+static struct kmem_cache *bip_slab;
+static struct workqueue_struct *kintegrityd_wq;
+
+void blk_flush_integrity(void)
+{
+ flush_workqueue(kintegrityd_wq);
+}
+
+/**
+ * bio_integrity_alloc - Allocate integrity payload and attach it to bio
+ * @bio: bio to attach integrity metadata to
+ * @gfp_mask: Memory allocation mask
+ * @nr_vecs: Number of integrity metadata scatter-gather elements
+ *
+ * Description: This function prepares a bio for attaching integrity
+ * metadata. nr_vecs specifies the maximum number of pages containing
+ * integrity metadata that can be attached.
+ */
+struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
+ gfp_t gfp_mask,
+ unsigned int nr_vecs)
+{
+ struct bio_integrity_payload *bip;
+ struct bio_set *bs = bio->bi_pool;
+ unsigned inline_vecs;
+
+ if (!bs || !bs->bio_integrity_pool) {
+ bip = kmalloc(sizeof(struct bio_integrity_payload) +
+ sizeof(struct bio_vec) * nr_vecs, gfp_mask);
+ inline_vecs = nr_vecs;
+ } else {
+ bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
+ inline_vecs = BIP_INLINE_VECS;
+ }
+
+ if (unlikely(!bip))
+ return ERR_PTR(-ENOMEM);
+
+ memset(bip, 0, sizeof(*bip));
+
+ if (nr_vecs > inline_vecs) {
+ unsigned long idx = 0;
+
+ bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx,
+ bs->bvec_integrity_pool);
+ if (!bip->bip_vec)
+ goto err;
+ bip->bip_max_vcnt = bvec_nr_vecs(idx);
+ bip->bip_slab = idx;
+ } else {
+ bip->bip_vec = bip->bip_inline_vecs;
+ bip->bip_max_vcnt = inline_vecs;
+ }
+
+ bip->bip_bio = bio;
+ bio->bi_integrity = bip;
+ bio->bi_opf |= REQ_INTEGRITY;
+
+ return bip;
+err:
+ mempool_free(bip, bs->bio_integrity_pool);
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL(bio_integrity_alloc);
+
+/**
+ * bio_integrity_free - Free bio integrity payload
+ * @bio: bio containing bip to be freed
+ *
+ * Description: Used to free the integrity portion of a bio. Usually
+ * called from bio_free().
+ */
+static void bio_integrity_free(struct bio *bio)
+{
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+ struct bio_set *bs = bio->bi_pool;
+
+ if (bip->bip_flags & BIP_BLOCK_INTEGRITY)
+ kfree(page_address(bip->bip_vec->bv_page) +
+ bip->bip_vec->bv_offset);
+
+ if (bs && bs->bio_integrity_pool) {
+ bvec_free(bs->bvec_integrity_pool, bip->bip_vec, bip->bip_slab);
+
+ mempool_free(bip, bs->bio_integrity_pool);
+ } else {
+ kfree(bip);
+ }
+
+ bio->bi_integrity = NULL;
+ bio->bi_opf &= ~REQ_INTEGRITY;
+}
+
+/**
+ * bio_integrity_add_page - Attach integrity metadata
+ * @bio: bio to update
+ * @page: page containing integrity metadata
+ * @len: number of bytes of integrity metadata in page
+ * @offset: start offset within page
+ *
+ * Description: Attach a page containing integrity metadata to bio.
+ */
+int bio_integrity_add_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset)
+{
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+ struct bio_vec *iv;
+
+ if (bip->bip_vcnt >= bip->bip_max_vcnt) {
+ printk(KERN_ERR "%s: bip_vec full\n", __func__);
+ return 0;
+ }
+
+ iv = bip->bip_vec + bip->bip_vcnt;
+
+ if (bip->bip_vcnt &&
+ bvec_gap_to_prev(bio->bi_disk->queue,
+ &bip->bip_vec[bip->bip_vcnt - 1], offset))
+ return 0;
+
+ iv->bv_page = page;
+ iv->bv_len = len;
+ iv->bv_offset = offset;
+ bip->bip_vcnt++;
+
+ return len;
+}
+EXPORT_SYMBOL(bio_integrity_add_page);
+
+/**
+ * bio_integrity_intervals - Return number of integrity intervals for a bio
+ * @bi: blk_integrity profile for device
+ * @sectors: Size of the bio in 512-byte sectors
+ *
+ * Description: The block layer calculates everything in 512 byte
+ * sectors but integrity metadata is done in terms of the data integrity
+ * interval size of the storage device. Convert the block layer sectors
+ * to the appropriate number of integrity intervals.
+ */
+static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
+ unsigned int sectors)
+{
+ return sectors >> (bi->interval_exp - 9);
+}
+
+static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
+ unsigned int sectors)
+{
+ return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
+}
+
+/**
+ * bio_integrity_process - Process integrity metadata for a bio
+ * @bio: bio to generate/verify integrity metadata for
+ * @proc_iter: iterator to process
+ * @proc_fn: Pointer to the relevant processing function
+ */
+static blk_status_t bio_integrity_process(struct bio *bio,
+ struct bvec_iter *proc_iter, integrity_processing_fn *proc_fn)
+{
+ struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+ struct blk_integrity_iter iter;
+ struct bvec_iter bviter;
+ struct bio_vec bv;
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+ blk_status_t ret = BLK_STS_OK;
+ void *prot_buf = page_address(bip->bip_vec->bv_page) +
+ bip->bip_vec->bv_offset;
+
+ iter.disk_name = bio->bi_disk->disk_name;
+ iter.interval = 1 << bi->interval_exp;
+ iter.seed = proc_iter->bi_sector;
+ iter.prot_buf = prot_buf;
+
+ __bio_for_each_segment(bv, bio, bviter, *proc_iter) {
+ void *kaddr = kmap_atomic(bv.bv_page);
+
+ iter.data_buf = kaddr + bv.bv_offset;
+ iter.data_size = bv.bv_len;
+
+ ret = proc_fn(&iter);
+ if (ret) {
+ kunmap_atomic(kaddr);
+ return ret;
+ }
+
+ kunmap_atomic(kaddr);
+ }
+ return ret;
+}
+
+/**
+ * bio_integrity_prep - Prepare bio for integrity I/O
+ * @bio: bio to prepare
+ *
+ * Description: Checks if the bio already has an integrity payload attached.
+ * If it does, the payload has been generated by another kernel subsystem,
+ * and we just pass it through. Otherwise allocates integrity payload.
+ * The bio must have data direction, target device and start sector set priot
+ * to calling. In the WRITE case, integrity metadata will be generated using
+ * the block device's integrity function. In the READ case, the buffer
+ * will be prepared for DMA and a suitable end_io handler set up.
+ */
+bool bio_integrity_prep(struct bio *bio)
+{
+ struct bio_integrity_payload *bip;
+ struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+ struct request_queue *q = bio->bi_disk->queue;
+ void *buf;
+ unsigned long start, end;
+ unsigned int len, nr_pages;
+ unsigned int bytes, offset, i;
+ unsigned int intervals;
+ blk_status_t status;
+
+ if (!bi)
+ return true;
+
+ if (bio_op(bio) != REQ_OP_READ && bio_op(bio) != REQ_OP_WRITE)
+ return true;
+
+ if (!bio_sectors(bio))
+ return true;
+
+ /* Already protected? */
+ if (bio_integrity(bio))
+ return true;
+
+ if (bio_data_dir(bio) == READ) {
+ if (!bi->profile->verify_fn ||
+ !(bi->flags & BLK_INTEGRITY_VERIFY))
+ return true;
+ } else {
+ if (!bi->profile->generate_fn ||
+ !(bi->flags & BLK_INTEGRITY_GENERATE))
+ return true;
+ }
+ intervals = bio_integrity_intervals(bi, bio_sectors(bio));
+
+ /* Allocate kernel buffer for protection data */
+ len = intervals * bi->tuple_size;
+ buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
+ status = BLK_STS_RESOURCE;
+ if (unlikely(buf == NULL)) {
+ printk(KERN_ERR "could not allocate integrity buffer\n");
+ goto err_end_io;
+ }
+
+ end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ start = ((unsigned long) buf) >> PAGE_SHIFT;
+ nr_pages = end - start;
+
+ /* Allocate bio integrity payload and integrity vectors */
+ bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
+ if (IS_ERR(bip)) {
+ printk(KERN_ERR "could not allocate data integrity bioset\n");
+ kfree(buf);
+ status = BLK_STS_RESOURCE;
+ goto err_end_io;
+ }
+
+ bip->bip_flags |= BIP_BLOCK_INTEGRITY;
+ bip->bip_iter.bi_size = len;
+ bip_set_seed(bip, bio->bi_iter.bi_sector);
+
+ if (bi->flags & BLK_INTEGRITY_IP_CHECKSUM)
+ bip->bip_flags |= BIP_IP_CHECKSUM;
+
+ /* Map it */
+ offset = offset_in_page(buf);
+ for (i = 0 ; i < nr_pages ; i++) {
+ int ret;
+ bytes = PAGE_SIZE - offset;
+
+ if (len <= 0)
+ break;
+
+ if (bytes > len)
+ bytes = len;
+
+ ret = bio_integrity_add_page(bio, virt_to_page(buf),
+ bytes, offset);
+
+ if (ret == 0) {
+ printk(KERN_ERR "could not attach integrity payload\n");
+ status = BLK_STS_RESOURCE;
+ goto err_end_io;
+ }
+
+ if (ret < bytes)
+ break;
+
+ buf += bytes;
+ len -= bytes;
+ offset = 0;
+ }
+
+ /* Auto-generate integrity metadata if this is a write */
+ if (bio_data_dir(bio) == WRITE) {
+ bio_integrity_process(bio, &bio->bi_iter,
+ bi->profile->generate_fn);
+ }
+ return true;
+
+err_end_io:
+ bio->bi_status = status;
+ bio_endio(bio);
+ return false;
+
+}
+EXPORT_SYMBOL(bio_integrity_prep);
+
+/**
+ * bio_integrity_verify_fn - Integrity I/O completion worker
+ * @work: Work struct stored in bio to be verified
+ *
+ * Description: This workqueue function is called to complete a READ
+ * request. The function verifies the transferred integrity metadata
+ * and then calls the original bio end_io function.
+ */
+static void bio_integrity_verify_fn(struct work_struct *work)
+{
+ struct bio_integrity_payload *bip =
+ container_of(work, struct bio_integrity_payload, bip_work);
+ struct bio *bio = bip->bip_bio;
+ struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+ struct bvec_iter iter = bio->bi_iter;
+
+ /*
+ * At the moment verify is called bio's iterator was advanced
+ * during split and completion, we need to rewind iterator to
+ * it's original position.
+ */
+ if (bio_rewind_iter(bio, &iter, iter.bi_done)) {
+ bio->bi_status = bio_integrity_process(bio, &iter,
+ bi->profile->verify_fn);
+ } else {
+ bio->bi_status = BLK_STS_IOERR;
+ }
+
+ bio_integrity_free(bio);
+ bio_endio(bio);
+}
+
+/**
+ * __bio_integrity_endio - Integrity I/O completion function
+ * @bio: Protected bio
+ * @error: Pointer to errno
+ *
+ * Description: Completion for integrity I/O
+ *
+ * Normally I/O completion is done in interrupt context. However,
+ * verifying I/O integrity is a time-consuming task which must be run
+ * in process context. This function postpones completion
+ * accordingly.
+ */
+bool __bio_integrity_endio(struct bio *bio)
+{
+ struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+
+ if (bio_op(bio) == REQ_OP_READ && !bio->bi_status &&
+ (bip->bip_flags & BIP_BLOCK_INTEGRITY) && bi->profile->verify_fn) {
+ INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
+ queue_work(kintegrityd_wq, &bip->bip_work);
+ return false;
+ }
+
+ bio_integrity_free(bio);
+ return true;
+}
+
+/**
+ * bio_integrity_advance - Advance integrity vector
+ * @bio: bio whose integrity vector to update
+ * @bytes_done: number of data bytes that have been completed
+ *
+ * Description: This function calculates how many integrity bytes the
+ * number of completed data bytes correspond to and advances the
+ * integrity vector accordingly.
+ */
+void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
+{
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+ struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+ unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
+
+ bip->bip_iter.bi_sector += bytes_done >> 9;
+ bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
+}
+EXPORT_SYMBOL(bio_integrity_advance);
+
+/**
+ * bio_integrity_trim - Trim integrity vector
+ * @bio: bio whose integrity vector to update
+ *
+ * Description: Used to trim the integrity vector in a cloned bio.
+ */
+void bio_integrity_trim(struct bio *bio)
+{
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+ struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+
+ bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
+}
+EXPORT_SYMBOL(bio_integrity_trim);
+
+/**
+ * bio_integrity_clone - Callback for cloning bios with integrity metadata
+ * @bio: New bio
+ * @bio_src: Original bio
+ * @gfp_mask: Memory allocation mask
+ *
+ * Description: Called to allocate a bip when cloning a bio
+ */
+int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
+ gfp_t gfp_mask)
+{
+ struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
+ struct bio_integrity_payload *bip;
+
+ BUG_ON(bip_src == NULL);
+
+ bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
+ if (IS_ERR(bip))
+ return PTR_ERR(bip);
+
+ memcpy(bip->bip_vec, bip_src->bip_vec,
+ bip_src->bip_vcnt * sizeof(struct bio_vec));
+
+ bip->bip_vcnt = bip_src->bip_vcnt;
+ bip->bip_iter = bip_src->bip_iter;
+
+ return 0;
+}
+EXPORT_SYMBOL(bio_integrity_clone);
+
+int bioset_integrity_create(struct bio_set *bs, int pool_size)
+{
+ if (bs->bio_integrity_pool)
+ return 0;
+
+ bs->bio_integrity_pool = mempool_create_slab_pool(pool_size, bip_slab);
+ if (!bs->bio_integrity_pool)
+ return -1;
+
+ bs->bvec_integrity_pool = biovec_create_pool(pool_size);
+ if (!bs->bvec_integrity_pool) {
+ mempool_destroy(bs->bio_integrity_pool);
+ return -1;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(bioset_integrity_create);
+
+void bioset_integrity_free(struct bio_set *bs)
+{
+ if (bs->bio_integrity_pool)
+ mempool_destroy(bs->bio_integrity_pool);
+
+ if (bs->bvec_integrity_pool)
+ mempool_destroy(bs->bvec_integrity_pool);
+}
+EXPORT_SYMBOL(bioset_integrity_free);
+
+void __init bio_integrity_init(void)
+{
+ /*
+ * kintegrityd won't block much but may burn a lot of CPU cycles.
+ * Make it highpri CPU intensive wq with max concurrency of 1.
+ */
+ kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
+ WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
+ if (!kintegrityd_wq)
+ panic("Failed to create kintegrityd\n");
+
+ bip_slab = kmem_cache_create("bio_integrity_payload",
+ sizeof(struct bio_integrity_payload) +
+ sizeof(struct bio_vec) * BIP_INLINE_VECS,
+ 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+}
diff --git a/src/kernel/linux/v4.14/block/bio.c b/src/kernel/linux/v4.14/block/bio.c
new file mode 100644
index 0000000..1384f97
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/bio.c
@@ -0,0 +1,2210 @@
+/*
+ * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public Licens
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
+ *
+ */
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/uio.h>
+#include <linux/iocontext.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/mempool.h>
+#include <linux/workqueue.h>
+#include <linux/cgroup.h>
+
+#include <trace/events/block.h>
+#include "blk.h"
+
+/*
+ * Test patch to inline a certain number of bi_io_vec's inside the bio
+ * itself, to shrink a bio data allocation from two mempool calls to one
+ */
+#define BIO_INLINE_VECS 4
+
+/*
+ * if you change this list, also change bvec_alloc or things will
+ * break badly! cannot be bigger than what you can fit into an
+ * unsigned short
+ */
+#define BV(x, n) { .nr_vecs = x, .name = "biovec-"#n }
+static struct biovec_slab bvec_slabs[BVEC_POOL_NR] __read_mostly = {
+ BV(1, 1), BV(4, 4), BV(16, 16), BV(64, 64), BV(128, 128), BV(BIO_MAX_PAGES, max),
+};
+#undef BV
+
+/*
+ * fs_bio_set is the bio_set containing bio and iovec memory pools used by
+ * IO code that does not need private memory pools.
+ */
+struct bio_set *fs_bio_set;
+EXPORT_SYMBOL(fs_bio_set);
+
+/*
+ * Our slab pool management
+ */
+struct bio_slab {
+ struct kmem_cache *slab;
+ unsigned int slab_ref;
+ unsigned int slab_size;
+ char name[8];
+};
+static DEFINE_MUTEX(bio_slab_lock);
+static struct bio_slab *bio_slabs;
+static unsigned int bio_slab_nr, bio_slab_max;
+
+static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size)
+{
+ unsigned int sz = sizeof(struct bio) + extra_size;
+ struct kmem_cache *slab = NULL;
+ struct bio_slab *bslab, *new_bio_slabs;
+ unsigned int new_bio_slab_max;
+ unsigned int i, entry = -1;
+
+ mutex_lock(&bio_slab_lock);
+
+ i = 0;
+ while (i < bio_slab_nr) {
+ bslab = &bio_slabs[i];
+
+ if (!bslab->slab && entry == -1)
+ entry = i;
+ else if (bslab->slab_size == sz) {
+ slab = bslab->slab;
+ bslab->slab_ref++;
+ break;
+ }
+ i++;
+ }
+
+ if (slab)
+ goto out_unlock;
+
+ if (bio_slab_nr == bio_slab_max && entry == -1) {
+ new_bio_slab_max = bio_slab_max << 1;
+ new_bio_slabs = krealloc(bio_slabs,
+ new_bio_slab_max * sizeof(struct bio_slab),
+ GFP_KERNEL);
+ if (!new_bio_slabs)
+ goto out_unlock;
+ bio_slab_max = new_bio_slab_max;
+ bio_slabs = new_bio_slabs;
+ }
+ if (entry == -1)
+ entry = bio_slab_nr++;
+
+ bslab = &bio_slabs[entry];
+
+ snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry);
+ slab = kmem_cache_create(bslab->name, sz, ARCH_KMALLOC_MINALIGN,
+ SLAB_HWCACHE_ALIGN, NULL);
+ if (!slab)
+ goto out_unlock;
+
+ bslab->slab = slab;
+ bslab->slab_ref = 1;
+ bslab->slab_size = sz;
+out_unlock:
+ mutex_unlock(&bio_slab_lock);
+ return slab;
+}
+
+static void bio_put_slab(struct bio_set *bs)
+{
+ struct bio_slab *bslab = NULL;
+ unsigned int i;
+
+ mutex_lock(&bio_slab_lock);
+
+ for (i = 0; i < bio_slab_nr; i++) {
+ if (bs->bio_slab == bio_slabs[i].slab) {
+ bslab = &bio_slabs[i];
+ break;
+ }
+ }
+
+ if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n"))
+ goto out;
+
+ WARN_ON(!bslab->slab_ref);
+
+ if (--bslab->slab_ref)
+ goto out;
+
+ kmem_cache_destroy(bslab->slab);
+ bslab->slab = NULL;
+
+out:
+ mutex_unlock(&bio_slab_lock);
+}
+
+unsigned int bvec_nr_vecs(unsigned short idx)
+{
+ return bvec_slabs[--idx].nr_vecs;
+}
+
+void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx)
+{
+ if (!idx)
+ return;
+ idx--;
+
+ BIO_BUG_ON(idx >= BVEC_POOL_NR);
+
+ if (idx == BVEC_POOL_MAX) {
+ mempool_free(bv, pool);
+ } else {
+ struct biovec_slab *bvs = bvec_slabs + idx;
+
+ kmem_cache_free(bvs->slab, bv);
+ }
+}
+
+struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
+ mempool_t *pool)
+{
+ struct bio_vec *bvl;
+
+ /*
+ * see comment near bvec_array define!
+ */
+ switch (nr) {
+ case 1:
+ *idx = 0;
+ break;
+ case 2 ... 4:
+ *idx = 1;
+ break;
+ case 5 ... 16:
+ *idx = 2;
+ break;
+ case 17 ... 64:
+ *idx = 3;
+ break;
+ case 65 ... 128:
+ *idx = 4;
+ break;
+ case 129 ... BIO_MAX_PAGES:
+ *idx = 5;
+ break;
+ default:
+ return NULL;
+ }
+
+ /*
+ * idx now points to the pool we want to allocate from. only the
+ * 1-vec entry pool is mempool backed.
+ */
+ if (*idx == BVEC_POOL_MAX) {
+fallback:
+ bvl = mempool_alloc(pool, gfp_mask);
+ } else {
+ struct biovec_slab *bvs = bvec_slabs + *idx;
+ gfp_t __gfp_mask = gfp_mask & ~(__GFP_DIRECT_RECLAIM | __GFP_IO);
+
+ /*
+ * Make this allocation restricted and don't dump info on
+ * allocation failures, since we'll fallback to the mempool
+ * in case of failure.
+ */
+ __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
+
+ /*
+ * Try a slab allocation. If this fails and __GFP_DIRECT_RECLAIM
+ * is set, retry with the 1-entry mempool
+ */
+ bvl = kmem_cache_alloc(bvs->slab, __gfp_mask);
+ if (unlikely(!bvl && (gfp_mask & __GFP_DIRECT_RECLAIM))) {
+ *idx = BVEC_POOL_MAX;
+ goto fallback;
+ }
+ }
+
+ (*idx)++;
+ return bvl;
+}
+
+void bio_uninit(struct bio *bio)
+{
+ bio_disassociate_task(bio);
+}
+EXPORT_SYMBOL(bio_uninit);
+
+static void bio_free(struct bio *bio)
+{
+ struct bio_set *bs = bio->bi_pool;
+ void *p;
+
+ bio_uninit(bio);
+
+ if (bs) {
+ bvec_free(bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(bio));
+
+ /*
+ * If we have front padding, adjust the bio pointer before freeing
+ */
+ p = bio;
+ p -= bs->front_pad;
+
+ mempool_free(p, bs->bio_pool);
+ } else {
+ /* Bio was allocated by bio_kmalloc() */
+ kfree(bio);
+ }
+}
+
+/*
+ * Users of this function have their own bio allocation. Subsequently,
+ * they must remember to pair any call to bio_init() with bio_uninit()
+ * when IO has completed, or when the bio is released.
+ */
+void bio_init(struct bio *bio, struct bio_vec *table,
+ unsigned short max_vecs)
+{
+ memset(bio, 0, sizeof(*bio));
+ atomic_set(&bio->__bi_remaining, 1);
+ atomic_set(&bio->__bi_cnt, 1);
+
+ bio->bi_io_vec = table;
+ bio->bi_max_vecs = max_vecs;
+}
+EXPORT_SYMBOL(bio_init);
+
+/**
+ * bio_reset - reinitialize a bio
+ * @bio: bio to reset
+ *
+ * Description:
+ * After calling bio_reset(), @bio will be in the same state as a freshly
+ * allocated bio returned bio bio_alloc_bioset() - the only fields that are
+ * preserved are the ones that are initialized by bio_alloc_bioset(). See
+ * comment in struct bio.
+ */
+void bio_reset(struct bio *bio)
+{
+ unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS);
+
+ bio_uninit(bio);
+
+ memset(bio, 0, BIO_RESET_BYTES);
+ bio->bi_flags = flags;
+ atomic_set(&bio->__bi_remaining, 1);
+}
+EXPORT_SYMBOL(bio_reset);
+
+static struct bio *__bio_chain_endio(struct bio *bio)
+{
+ struct bio *parent = bio->bi_private;
+
+ if (!parent->bi_status)
+ parent->bi_status = bio->bi_status;
+ bio_put(bio);
+ return parent;
+}
+
+static void bio_chain_endio(struct bio *bio)
+{
+ bio_endio(__bio_chain_endio(bio));
+}
+
+/**
+ * bio_chain - chain bio completions
+ * @bio: the target bio
+ * @parent: the @bio's parent bio
+ *
+ * The caller won't have a bi_end_io called when @bio completes - instead,
+ * @parent's bi_end_io won't be called until both @parent and @bio have
+ * completed; the chained bio will also be freed when it completes.
+ *
+ * The caller must not set bi_private or bi_end_io in @bio.
+ */
+void bio_chain(struct bio *bio, struct bio *parent)
+{
+ BUG_ON(bio->bi_private || bio->bi_end_io);
+
+ bio->bi_private = parent;
+ bio->bi_end_io = bio_chain_endio;
+ bio_inc_remaining(parent);
+}
+EXPORT_SYMBOL(bio_chain);
+
+static void bio_alloc_rescue(struct work_struct *work)
+{
+ struct bio_set *bs = container_of(work, struct bio_set, rescue_work);
+ struct bio *bio;
+
+ while (1) {
+ spin_lock(&bs->rescue_lock);
+ bio = bio_list_pop(&bs->rescue_list);
+ spin_unlock(&bs->rescue_lock);
+
+ if (!bio)
+ break;
+
+ generic_make_request(bio);
+ }
+}
+
+static void punt_bios_to_rescuer(struct bio_set *bs)
+{
+ struct bio_list punt, nopunt;
+ struct bio *bio;
+
+ if (WARN_ON_ONCE(!bs->rescue_workqueue))
+ return;
+ /*
+ * In order to guarantee forward progress we must punt only bios that
+ * were allocated from this bio_set; otherwise, if there was a bio on
+ * there for a stacking driver higher up in the stack, processing it
+ * could require allocating bios from this bio_set, and doing that from
+ * our own rescuer would be bad.
+ *
+ * Since bio lists are singly linked, pop them all instead of trying to
+ * remove from the middle of the list:
+ */
+
+ bio_list_init(&punt);
+ bio_list_init(&nopunt);
+
+ while ((bio = bio_list_pop(¤t->bio_list[0])))
+ bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio);
+ current->bio_list[0] = nopunt;
+
+ bio_list_init(&nopunt);
+ while ((bio = bio_list_pop(¤t->bio_list[1])))
+ bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio);
+ current->bio_list[1] = nopunt;
+
+ spin_lock(&bs->rescue_lock);
+ bio_list_merge(&bs->rescue_list, &punt);
+ spin_unlock(&bs->rescue_lock);
+
+ queue_work(bs->rescue_workqueue, &bs->rescue_work);
+}
+
+/**
+ * bio_alloc_bioset - allocate a bio for I/O
+ * @gfp_mask: the GFP_ mask given to the slab allocator
+ * @nr_iovecs: number of iovecs to pre-allocate
+ * @bs: the bio_set to allocate from.
+ *
+ * Description:
+ * If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is
+ * backed by the @bs's mempool.
+ *
+ * When @bs is not NULL, if %__GFP_DIRECT_RECLAIM is set then bio_alloc will
+ * always be able to allocate a bio. This is due to the mempool guarantees.
+ * To make this work, callers must never allocate more than 1 bio at a time
+ * from this pool. Callers that need to allocate more than 1 bio must always
+ * submit the previously allocated bio for IO before attempting to allocate
+ * a new one. Failure to do so can cause deadlocks under memory pressure.
+ *
+ * Note that when running under generic_make_request() (i.e. any block
+ * driver), bios are not submitted until after you return - see the code in
+ * generic_make_request() that converts recursion into iteration, to prevent
+ * stack overflows.
+ *
+ * This would normally mean allocating multiple bios under
+ * generic_make_request() would be susceptible to deadlocks, but we have
+ * deadlock avoidance code that resubmits any blocked bios from a rescuer
+ * thread.
+ *
+ * However, we do not guarantee forward progress for allocations from other
+ * mempools. Doing multiple allocations from the same mempool under
+ * generic_make_request() should be avoided - instead, use bio_set's front_pad
+ * for per bio allocations.
+ *
+ * RETURNS:
+ * Pointer to new bio on success, NULL on failure.
+ */
+struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs,
+ struct bio_set *bs)
+{
+ gfp_t saved_gfp = gfp_mask;
+ unsigned front_pad;
+ unsigned inline_vecs;
+ struct bio_vec *bvl = NULL;
+ struct bio *bio;
+ void *p;
+
+ if (!bs) {
+ if (nr_iovecs > UIO_MAXIOV)
+ return NULL;
+
+ p = kmalloc(sizeof(struct bio) +
+ nr_iovecs * sizeof(struct bio_vec),
+ gfp_mask);
+ front_pad = 0;
+ inline_vecs = nr_iovecs;
+ } else {
+ /* should not use nobvec bioset for nr_iovecs > 0 */
+ if (WARN_ON_ONCE(!bs->bvec_pool && nr_iovecs > 0))
+ return NULL;
+ /*
+ * generic_make_request() converts recursion to iteration; this
+ * means if we're running beneath it, any bios we allocate and
+ * submit will not be submitted (and thus freed) until after we
+ * return.
+ *
+ * This exposes us to a potential deadlock if we allocate
+ * multiple bios from the same bio_set() while running
+ * underneath generic_make_request(). If we were to allocate
+ * multiple bios (say a stacking block driver that was splitting
+ * bios), we would deadlock if we exhausted the mempool's
+ * reserve.
+ *
+ * We solve this, and guarantee forward progress, with a rescuer
+ * workqueue per bio_set. If we go to allocate and there are
+ * bios on current->bio_list, we first try the allocation
+ * without __GFP_DIRECT_RECLAIM; if that fails, we punt those
+ * bios we would be blocking to the rescuer workqueue before
+ * we retry with the original gfp_flags.
+ */
+
+ if (current->bio_list &&
+ (!bio_list_empty(¤t->bio_list[0]) ||
+ !bio_list_empty(¤t->bio_list[1])) &&
+ bs->rescue_workqueue)
+ gfp_mask &= ~__GFP_DIRECT_RECLAIM;
+
+ p = mempool_alloc(bs->bio_pool, gfp_mask);
+ if (!p && gfp_mask != saved_gfp) {
+ punt_bios_to_rescuer(bs);
+ gfp_mask = saved_gfp;
+ p = mempool_alloc(bs->bio_pool, gfp_mask);
+ }
+
+ front_pad = bs->front_pad;
+ inline_vecs = BIO_INLINE_VECS;
+ }
+
+ if (unlikely(!p))
+ return NULL;
+
+ bio = p + front_pad;
+ bio_init(bio, NULL, 0);
+
+ if (nr_iovecs > inline_vecs) {
+ unsigned long idx = 0;
+
+ bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
+ if (!bvl && gfp_mask != saved_gfp) {
+ punt_bios_to_rescuer(bs);
+ gfp_mask = saved_gfp;
+ bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
+ }
+
+ if (unlikely(!bvl))
+ goto err_free;
+
+ bio->bi_flags |= idx << BVEC_POOL_OFFSET;
+ } else if (nr_iovecs) {
+ bvl = bio->bi_inline_vecs;
+ }
+
+ bio->bi_pool = bs;
+ bio->bi_max_vecs = nr_iovecs;
+ bio->bi_io_vec = bvl;
+ return bio;
+
+err_free:
+ mempool_free(p, bs->bio_pool);
+ return NULL;
+}
+EXPORT_SYMBOL(bio_alloc_bioset);
+
+void zero_fill_bio(struct bio *bio)
+{
+ unsigned long flags;
+ struct bio_vec bv;
+ struct bvec_iter iter;
+
+ bio_for_each_segment(bv, bio, iter) {
+ char *data = bvec_kmap_irq(&bv, &flags);
+ memset(data, 0, bv.bv_len);
+ flush_dcache_page(bv.bv_page);
+ bvec_kunmap_irq(data, &flags);
+ }
+}
+EXPORT_SYMBOL(zero_fill_bio);
+
+/**
+ * bio_put - release a reference to a bio
+ * @bio: bio to release reference to
+ *
+ * Description:
+ * Put a reference to a &struct bio, either one you have gotten with
+ * bio_alloc, bio_get or bio_clone_*. The last put of a bio will free it.
+ **/
+void bio_put(struct bio *bio)
+{
+ if (!bio_flagged(bio, BIO_REFFED))
+ bio_free(bio);
+ else {
+ BIO_BUG_ON(!atomic_read(&bio->__bi_cnt));
+
+ /*
+ * last put frees it
+ */
+ if (atomic_dec_and_test(&bio->__bi_cnt))
+ bio_free(bio);
+ }
+}
+EXPORT_SYMBOL(bio_put);
+
+inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
+{
+ if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
+ blk_recount_segments(q, bio);
+
+ return bio->bi_phys_segments;
+}
+EXPORT_SYMBOL(bio_phys_segments);
+
+/**
+ * __bio_clone_fast - clone a bio that shares the original bio's biovec
+ * @bio: destination bio
+ * @bio_src: bio to clone
+ *
+ * Clone a &bio. Caller will own the returned bio, but not
+ * the actual data it points to. Reference count of returned
+ * bio will be one.
+ *
+ * Caller must ensure that @bio_src is not freed before @bio.
+ */
+void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
+{
+ BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio));
+
+ /*
+ * most users will be overriding ->bi_disk with a new target,
+ * so we don't set nor calculate new physical/hw segment counts here
+ */
+ bio->bi_disk = bio_src->bi_disk;
+ bio->bi_partno = bio_src->bi_partno;
+ bio_set_flag(bio, BIO_CLONED);
+ if (bio_flagged(bio_src, BIO_THROTTLED))
+ bio_set_flag(bio, BIO_THROTTLED);
+ bio->bi_opf = bio_src->bi_opf;
+ bio->bi_write_hint = bio_src->bi_write_hint;
+ bio->bi_iter = bio_src->bi_iter;
+ bio->bi_io_vec = bio_src->bi_io_vec;
+
+ bio_clone_blkcg_association(bio, bio_src);
+}
+EXPORT_SYMBOL(__bio_clone_fast);
+
+/**
+ * bio_clone_fast - clone a bio that shares the original bio's biovec
+ * @bio: bio to clone
+ * @gfp_mask: allocation priority
+ * @bs: bio_set to allocate from
+ *
+ * Like __bio_clone_fast, only also allocates the returned bio
+ */
+struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
+{
+ struct bio *b;
+
+ b = bio_alloc_bioset(gfp_mask, 0, bs);
+ if (!b)
+ return NULL;
+
+ __bio_clone_fast(b, bio);
+
+ if (bio_integrity(bio)) {
+ int ret;
+
+ ret = bio_integrity_clone(b, bio, gfp_mask);
+
+ if (ret < 0) {
+ bio_put(b);
+ return NULL;
+ }
+ }
+
+ return b;
+}
+EXPORT_SYMBOL(bio_clone_fast);
+
+/**
+ * bio_clone_bioset - clone a bio
+ * @bio_src: bio to clone
+ * @gfp_mask: allocation priority
+ * @bs: bio_set to allocate from
+ *
+ * Clone bio. Caller will own the returned bio, but not the actual data it
+ * points to. Reference count of returned bio will be one.
+ */
+struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
+ struct bio_set *bs)
+{
+ struct bvec_iter iter;
+ struct bio_vec bv;
+ struct bio *bio;
+
+ /*
+ * Pre immutable biovecs, __bio_clone() used to just do a memcpy from
+ * bio_src->bi_io_vec to bio->bi_io_vec.
+ *
+ * We can't do that anymore, because:
+ *
+ * - The point of cloning the biovec is to produce a bio with a biovec
+ * the caller can modify: bi_idx and bi_bvec_done should be 0.
+ *
+ * - The original bio could've had more than BIO_MAX_PAGES biovecs; if
+ * we tried to clone the whole thing bio_alloc_bioset() would fail.
+ * But the clone should succeed as long as the number of biovecs we
+ * actually need to allocate is fewer than BIO_MAX_PAGES.
+ *
+ * - Lastly, bi_vcnt should not be looked at or relied upon by code
+ * that does not own the bio - reason being drivers don't use it for
+ * iterating over the biovec anymore, so expecting it to be kept up
+ * to date (i.e. for clones that share the parent biovec) is just
+ * asking for trouble and would force extra work on
+ * __bio_clone_fast() anyways.
+ */
+
+ bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
+ if (!bio)
+ return NULL;
+ bio->bi_disk = bio_src->bi_disk;
+ bio->bi_opf = bio_src->bi_opf;
+ bio->bi_write_hint = bio_src->bi_write_hint;
+ bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
+ bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;
+
+ switch (bio_op(bio)) {
+ case REQ_OP_DISCARD:
+ case REQ_OP_SECURE_ERASE:
+ case REQ_OP_WRITE_ZEROES:
+ break;
+ case REQ_OP_WRITE_SAME:
+ bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0];
+ break;
+ default:
+ bio_for_each_segment(bv, bio_src, iter)
+ bio->bi_io_vec[bio->bi_vcnt++] = bv;
+ break;
+ }
+
+ if (bio_integrity(bio_src)) {
+ int ret;
+
+ ret = bio_integrity_clone(bio, bio_src, gfp_mask);
+ if (ret < 0) {
+ bio_put(bio);
+ return NULL;
+ }
+ }
+
+ bio_clone_blkcg_association(bio, bio_src);
+
+ return bio;
+}
+EXPORT_SYMBOL(bio_clone_bioset);
+
+/**
+ * bio_add_pc_page - attempt to add page to bio
+ * @q: the target queue
+ * @bio: destination bio
+ * @page: page to add
+ * @len: vec entry length
+ * @offset: vec entry offset
+ *
+ * Attempt to add a page to the bio_vec maplist. This can fail for a
+ * number of reasons, such as the bio being full or target block device
+ * limitations. The target block device must allow bio's up to PAGE_SIZE,
+ * so it is always possible to add a single page to an empty bio.
+ *
+ * This should only be used by REQ_PC bios.
+ */
+int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page
+ *page, unsigned int len, unsigned int offset)
+{
+ int retried_segments = 0;
+ struct bio_vec *bvec;
+
+ /*
+ * cloned bio must not modify vec list
+ */
+ if (unlikely(bio_flagged(bio, BIO_CLONED)))
+ return 0;
+
+ if (((bio->bi_iter.bi_size + len) >> 9) > queue_max_hw_sectors(q))
+ return 0;
+
+ /*
+ * For filesystems with a blocksize smaller than the pagesize
+ * we will often be called with the same page as last time and
+ * a consecutive offset. Optimize this special case.
+ */
+ if (bio->bi_vcnt > 0) {
+ struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
+
+ if (page == prev->bv_page &&
+ offset == prev->bv_offset + prev->bv_len) {
+ prev->bv_len += len;
+ bio->bi_iter.bi_size += len;
+ goto done;
+ }
+
+ /*
+ * If the queue doesn't support SG gaps and adding this
+ * offset would create a gap, disallow it.
+ */
+ if (bvec_gap_to_prev(q, prev, offset))
+ return 0;
+ }
+
+ if (bio_full(bio))
+ return 0;
+
+ /*
+ * setup the new entry, we might clear it again later if we
+ * cannot add the page
+ */
+ bvec = &bio->bi_io_vec[bio->bi_vcnt];
+ bvec->bv_page = page;
+ bvec->bv_len = len;
+ bvec->bv_offset = offset;
+ bio->bi_vcnt++;
+ bio->bi_phys_segments++;
+ bio->bi_iter.bi_size += len;
+
+ /*
+ * Perform a recount if the number of segments is greater
+ * than queue_max_segments(q).
+ */
+
+ while (bio->bi_phys_segments > queue_max_segments(q)) {
+
+ if (retried_segments)
+ goto failed;
+
+ retried_segments = 1;
+ blk_recount_segments(q, bio);
+ }
+
+ /* If we may be able to merge these biovecs, force a recount */
+ if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
+ bio_clear_flag(bio, BIO_SEG_VALID);
+
+ done:
+ return len;
+
+ failed:
+ bvec->bv_page = NULL;
+ bvec->bv_len = 0;
+ bvec->bv_offset = 0;
+ bio->bi_vcnt--;
+ bio->bi_iter.bi_size -= len;
+ blk_recount_segments(q, bio);
+ return 0;
+}
+EXPORT_SYMBOL(bio_add_pc_page);
+
+/**
+ * __bio_try_merge_page - try appending data to an existing bvec.
+ * @bio: destination bio
+ * @page: page to add
+ * @len: length of the data to add
+ * @off: offset of the data in @page
+ *
+ * Try to add the data at @page + @off to the last bvec of @bio. This is a
+ * a useful optimisation for file systems with a block size smaller than the
+ * page size.
+ *
+ * Return %true on success or %false on failure.
+ */
+bool __bio_try_merge_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int off)
+{
+ if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
+ return false;
+
+ if (bio->bi_vcnt > 0) {
+ struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
+
+ if (page == bv->bv_page && off == bv->bv_offset + bv->bv_len) {
+ bv->bv_len += len;
+ bio->bi_iter.bi_size += len;
+ return true;
+ }
+ }
+ return false;
+}
+EXPORT_SYMBOL_GPL(__bio_try_merge_page);
+
+/**
+ * __bio_add_page - add page to a bio in a new segment
+ * @bio: destination bio
+ * @page: page to add
+ * @len: length of the data to add
+ * @off: offset of the data in @page
+ *
+ * Add the data at @page + @off to @bio as a new bvec. The caller must ensure
+ * that @bio has space for another bvec.
+ */
+void __bio_add_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int off)
+{
+ struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt];
+
+ WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
+ WARN_ON_ONCE(bio_full(bio));
+
+ bv->bv_page = page;
+ bv->bv_offset = off;
+ bv->bv_len = len;
+
+ bio->bi_iter.bi_size += len;
+ bio->bi_vcnt++;
+}
+EXPORT_SYMBOL_GPL(__bio_add_page);
+
+/**
+ * bio_add_page - attempt to add page to bio
+ * @bio: destination bio
+ * @page: page to add
+ * @len: vec entry length
+ * @offset: vec entry offset
+ *
+ * Attempt to add a page to the bio_vec maplist. This will only fail
+ * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio.
+ */
+int bio_add_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset)
+{
+ if (!__bio_try_merge_page(bio, page, len, offset)) {
+ if (bio_full(bio))
+ return 0;
+ __bio_add_page(bio, page, len, offset);
+ }
+ return len;
+}
+EXPORT_SYMBOL(bio_add_page);
+
+/**
+ * __bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio
+ * @bio: bio to add pages to
+ * @iter: iov iterator describing the region to be mapped
+ *
+ * Pins pages from *iter and appends them to @bio's bvec array. The
+ * pages will have to be released using put_page() when done.
+ * For multi-segment *iter, this function only adds pages from the
+ * the next non-empty segment of the iov iterator.
+ */
+static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
+{
+ unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt, idx;
+ struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;
+ struct page **pages = (struct page **)bv;
+ size_t offset;
+ ssize_t size;
+
+ size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset);
+ if (unlikely(size <= 0))
+ return size ? size : -EFAULT;
+ idx = nr_pages = (size + offset + PAGE_SIZE - 1) / PAGE_SIZE;
+
+ /*
+ * Deep magic below: We need to walk the pinned pages backwards
+ * because we are abusing the space allocated for the bio_vecs
+ * for the page array. Because the bio_vecs are larger than the
+ * page pointers by definition this will always work. But it also
+ * means we can't use bio_add_page, so any changes to it's semantics
+ * need to be reflected here as well.
+ */
+ bio->bi_iter.bi_size += size;
+ bio->bi_vcnt += nr_pages;
+
+ while (idx--) {
+ bv[idx].bv_page = pages[idx];
+ bv[idx].bv_len = PAGE_SIZE;
+ bv[idx].bv_offset = 0;
+ }
+
+ bv[0].bv_offset += offset;
+ bv[0].bv_len -= offset;
+ bv[nr_pages - 1].bv_len -= nr_pages * PAGE_SIZE - offset - size;
+
+ iov_iter_advance(iter, size);
+ return 0;
+}
+
+/**
+ * bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio
+ * @bio: bio to add pages to
+ * @iter: iov iterator describing the region to be mapped
+ *
+ * Pins pages from *iter and appends them to @bio's bvec array. The
+ * pages will have to be released using put_page() when done.
+ * The function tries, but does not guarantee, to pin as many pages as
+ * fit into the bio, or are requested in *iter, whatever is smaller.
+ * If MM encounters an error pinning the requested pages, it stops.
+ * Error is returned only if 0 pages could be pinned.
+ */
+int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
+{
+ unsigned short orig_vcnt = bio->bi_vcnt;
+
+ do {
+ int ret = __bio_iov_iter_get_pages(bio, iter);
+
+ if (unlikely(ret))
+ return bio->bi_vcnt > orig_vcnt ? 0 : ret;
+
+ } while (iov_iter_count(iter) && !bio_full(bio));
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages);
+
+struct submit_bio_ret {
+ struct completion event;
+ int error;
+};
+
+static void submit_bio_wait_endio(struct bio *bio)
+{
+ struct submit_bio_ret *ret = bio->bi_private;
+
+ ret->error = blk_status_to_errno(bio->bi_status);
+ complete(&ret->event);
+}
+
+/**
+ * submit_bio_wait - submit a bio, and wait until it completes
+ * @bio: The &struct bio which describes the I/O
+ *
+ * Simple wrapper around submit_bio(). Returns 0 on success, or the error from
+ * bio_endio() on failure.
+ *
+ * WARNING: Unlike to how submit_bio() is usually used, this function does not
+ * result in bio reference to be consumed. The caller must drop the reference
+ * on his own.
+ */
+int submit_bio_wait(struct bio *bio)
+{
+ struct submit_bio_ret ret;
+
+ init_completion(&ret.event);
+ bio->bi_private = &ret;
+ bio->bi_end_io = submit_bio_wait_endio;
+ bio->bi_opf |= REQ_SYNC;
+ submit_bio(bio);
+ wait_for_completion_io(&ret.event);
+
+ return ret.error;
+}
+EXPORT_SYMBOL(submit_bio_wait);
+
+/**
+ * bio_advance - increment/complete a bio by some number of bytes
+ * @bio: bio to advance
+ * @bytes: number of bytes to complete
+ *
+ * This updates bi_sector, bi_size and bi_idx; if the number of bytes to
+ * complete doesn't align with a bvec boundary, then bv_len and bv_offset will
+ * be updated on the last bvec as well.
+ *
+ * @bio will then represent the remaining, uncompleted portion of the io.
+ */
+void bio_advance(struct bio *bio, unsigned bytes)
+{
+ if (bio_integrity(bio))
+ bio_integrity_advance(bio, bytes);
+
+ bio_advance_iter(bio, &bio->bi_iter, bytes);
+}
+EXPORT_SYMBOL(bio_advance);
+
+/**
+ * bio_alloc_pages - allocates a single page for each bvec in a bio
+ * @bio: bio to allocate pages for
+ * @gfp_mask: flags for allocation
+ *
+ * Allocates pages up to @bio->bi_vcnt.
+ *
+ * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are
+ * freed.
+ */
+int bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
+{
+ int i;
+ struct bio_vec *bv;
+
+ bio_for_each_segment_all(bv, bio, i) {
+ bv->bv_page = alloc_page(gfp_mask);
+ if (!bv->bv_page) {
+ while (--bv >= bio->bi_io_vec)
+ __free_page(bv->bv_page);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(bio_alloc_pages);
+
+/**
+ * bio_copy_data - copy contents of data buffers from one chain of bios to
+ * another
+ * @src: source bio list
+ * @dst: destination bio list
+ *
+ * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats
+ * @src and @dst as linked lists of bios.
+ *
+ * Stops when it reaches the end of either @src or @dst - that is, copies
+ * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios).
+ */
+void bio_copy_data(struct bio *dst, struct bio *src)
+{
+ struct bvec_iter src_iter, dst_iter;
+ struct bio_vec src_bv, dst_bv;
+ void *src_p, *dst_p;
+ unsigned bytes;
+
+ src_iter = src->bi_iter;
+ dst_iter = dst->bi_iter;
+
+ while (1) {
+ if (!src_iter.bi_size) {
+ src = src->bi_next;
+ if (!src)
+ break;
+
+ src_iter = src->bi_iter;
+ }
+
+ if (!dst_iter.bi_size) {
+ dst = dst->bi_next;
+ if (!dst)
+ break;
+
+ dst_iter = dst->bi_iter;
+ }
+
+ src_bv = bio_iter_iovec(src, src_iter);
+ dst_bv = bio_iter_iovec(dst, dst_iter);
+
+ bytes = min(src_bv.bv_len, dst_bv.bv_len);
+
+ src_p = kmap_atomic(src_bv.bv_page);
+ dst_p = kmap_atomic(dst_bv.bv_page);
+
+ memcpy(dst_p + dst_bv.bv_offset,
+ src_p + src_bv.bv_offset,
+ bytes);
+
+ kunmap_atomic(dst_p);
+ kunmap_atomic(src_p);
+
+ bio_advance_iter(src, &src_iter, bytes);
+ bio_advance_iter(dst, &dst_iter, bytes);
+ }
+}
+EXPORT_SYMBOL(bio_copy_data);
+
+struct bio_map_data {
+ int is_our_pages;
+ struct iov_iter iter;
+ struct iovec iov[];
+};
+
+static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count,
+ gfp_t gfp_mask)
+{
+ if (iov_count > UIO_MAXIOV)
+ return NULL;
+
+ return kmalloc(sizeof(struct bio_map_data) +
+ sizeof(struct iovec) * iov_count, gfp_mask);
+}
+
+/**
+ * bio_copy_from_iter - copy all pages from iov_iter to bio
+ * @bio: The &struct bio which describes the I/O as destination
+ * @iter: iov_iter as source
+ *
+ * Copy all pages from iov_iter to bio.
+ * Returns 0 on success, or error on failure.
+ */
+static int bio_copy_from_iter(struct bio *bio, struct iov_iter iter)
+{
+ int i;
+ struct bio_vec *bvec;
+
+ bio_for_each_segment_all(bvec, bio, i) {
+ ssize_t ret;
+
+ ret = copy_page_from_iter(bvec->bv_page,
+ bvec->bv_offset,
+ bvec->bv_len,
+ &iter);
+
+ if (!iov_iter_count(&iter))
+ break;
+
+ if (ret < bvec->bv_len)
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+/**
+ * bio_copy_to_iter - copy all pages from bio to iov_iter
+ * @bio: The &struct bio which describes the I/O as source
+ * @iter: iov_iter as destination
+ *
+ * Copy all pages from bio to iov_iter.
+ * Returns 0 on success, or error on failure.
+ */
+static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
+{
+ int i;
+ struct bio_vec *bvec;
+
+ bio_for_each_segment_all(bvec, bio, i) {
+ ssize_t ret;
+
+ ret = copy_page_to_iter(bvec->bv_page,
+ bvec->bv_offset,
+ bvec->bv_len,
+ &iter);
+
+ if (!iov_iter_count(&iter))
+ break;
+
+ if (ret < bvec->bv_len)
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+void bio_free_pages(struct bio *bio)
+{
+ struct bio_vec *bvec;
+ int i;
+
+ bio_for_each_segment_all(bvec, bio, i)
+ __free_page(bvec->bv_page);
+}
+EXPORT_SYMBOL(bio_free_pages);
+
+/**
+ * bio_uncopy_user - finish previously mapped bio
+ * @bio: bio being terminated
+ *
+ * Free pages allocated from bio_copy_user_iov() and write back data
+ * to user space in case of a read.
+ */
+int bio_uncopy_user(struct bio *bio)
+{
+ struct bio_map_data *bmd = bio->bi_private;
+ int ret = 0;
+
+ if (!bio_flagged(bio, BIO_NULL_MAPPED)) {
+ /*
+ * if we're in a workqueue, the request is orphaned, so
+ * don't copy into a random user address space, just free
+ * and return -EINTR so user space doesn't expect any data.
+ */
+ if (!current->mm)
+ ret = -EINTR;
+ else if (bio_data_dir(bio) == READ)
+ ret = bio_copy_to_iter(bio, bmd->iter);
+ if (bmd->is_our_pages)
+ bio_free_pages(bio);
+ }
+ kfree(bmd);
+ bio_put(bio);
+ return ret;
+}
+
+/**
+ * bio_copy_user_iov - copy user data to bio
+ * @q: destination block queue
+ * @map_data: pointer to the rq_map_data holding pages (if necessary)
+ * @iter: iovec iterator
+ * @gfp_mask: memory allocation flags
+ *
+ * Prepares and returns a bio for indirect user io, bouncing data
+ * to/from kernel pages as necessary. Must be paired with
+ * call bio_uncopy_user() on io completion.
+ */
+struct bio *bio_copy_user_iov(struct request_queue *q,
+ struct rq_map_data *map_data,
+ const struct iov_iter *iter,
+ gfp_t gfp_mask)
+{
+ struct bio_map_data *bmd;
+ struct page *page;
+ struct bio *bio;
+ int i, ret;
+ int nr_pages = 0;
+ unsigned int len = iter->count;
+ unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
+
+ for (i = 0; i < iter->nr_segs; i++) {
+ unsigned long uaddr;
+ unsigned long end;
+ unsigned long start;
+
+ uaddr = (unsigned long) iter->iov[i].iov_base;
+ end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1)
+ >> PAGE_SHIFT;
+ start = uaddr >> PAGE_SHIFT;
+
+ /*
+ * Overflow, abort
+ */
+ if (end < start)
+ return ERR_PTR(-EINVAL);
+
+ nr_pages += end - start;
+ }
+
+ if (offset)
+ nr_pages++;
+
+ bmd = bio_alloc_map_data(iter->nr_segs, gfp_mask);
+ if (!bmd)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * We need to do a deep copy of the iov_iter including the iovecs.
+ * The caller provided iov might point to an on-stack or otherwise
+ * shortlived one.
+ */
+ bmd->is_our_pages = map_data ? 0 : 1;
+ memcpy(bmd->iov, iter->iov, sizeof(struct iovec) * iter->nr_segs);
+ bmd->iter = *iter;
+ bmd->iter.iov = bmd->iov;
+
+ ret = -ENOMEM;
+ bio = bio_kmalloc(gfp_mask, nr_pages);
+ if (!bio)
+ goto out_bmd;
+
+ ret = 0;
+
+ if (map_data) {
+ nr_pages = 1 << map_data->page_order;
+ i = map_data->offset / PAGE_SIZE;
+ }
+ while (len) {
+ unsigned int bytes = PAGE_SIZE;
+
+ bytes -= offset;
+
+ if (bytes > len)
+ bytes = len;
+
+ if (map_data) {
+ if (i == map_data->nr_entries * nr_pages) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ page = map_data->pages[i / nr_pages];
+ page += (i % nr_pages);
+
+ i++;
+ } else {
+ page = alloc_page(q->bounce_gfp | gfp_mask);
+ if (!page) {
+ ret = -ENOMEM;
+ break;
+ }
+ }
+
+ if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) {
+ if (!map_data)
+ __free_page(page);
+ break;
+ }
+
+ len -= bytes;
+ offset = 0;
+ }
+
+ if (ret)
+ goto cleanup;
+
+ /*
+ * success
+ */
+ if (((iter->type & WRITE) && (!map_data || !map_data->null_mapped)) ||
+ (map_data && map_data->from_user)) {
+ ret = bio_copy_from_iter(bio, *iter);
+ if (ret)
+ goto cleanup;
+ }
+
+ bio->bi_private = bmd;
+ return bio;
+cleanup:
+ if (!map_data)
+ bio_free_pages(bio);
+ bio_put(bio);
+out_bmd:
+ kfree(bmd);
+ return ERR_PTR(ret);
+}
+
+/**
+ * bio_map_user_iov - map user iovec into bio
+ * @q: the struct request_queue for the bio
+ * @iter: iovec iterator
+ * @gfp_mask: memory allocation flags
+ *
+ * Map the user space address into a bio suitable for io to a block
+ * device. Returns an error pointer in case of error.
+ */
+struct bio *bio_map_user_iov(struct request_queue *q,
+ const struct iov_iter *iter,
+ gfp_t gfp_mask)
+{
+ int j;
+ int nr_pages = 0;
+ struct page **pages;
+ struct bio *bio;
+ int cur_page = 0;
+ int ret, offset;
+ struct iov_iter i;
+ struct iovec iov;
+ struct bio_vec *bvec;
+
+ iov_for_each(iov, i, *iter) {
+ unsigned long uaddr = (unsigned long) iov.iov_base;
+ unsigned long len = iov.iov_len;
+ unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = uaddr >> PAGE_SHIFT;
+
+ /*
+ * Overflow, abort
+ */
+ if (end < start)
+ return ERR_PTR(-EINVAL);
+
+ nr_pages += end - start;
+ /*
+ * buffer must be aligned to at least logical block size for now
+ */
+ if (uaddr & queue_dma_alignment(q))
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!nr_pages)
+ return ERR_PTR(-EINVAL);
+
+ bio = bio_kmalloc(gfp_mask, nr_pages);
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ ret = -ENOMEM;
+ pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask);
+ if (!pages)
+ goto out;
+
+ iov_for_each(iov, i, *iter) {
+ unsigned long uaddr = (unsigned long) iov.iov_base;
+ unsigned long len = iov.iov_len;
+ unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = uaddr >> PAGE_SHIFT;
+ const int local_nr_pages = end - start;
+ const int page_limit = cur_page + local_nr_pages;
+
+ ret = get_user_pages_fast(uaddr, local_nr_pages,
+ (iter->type & WRITE) != WRITE,
+ &pages[cur_page]);
+ if (unlikely(ret < local_nr_pages)) {
+ for (j = cur_page; j < page_limit; j++) {
+ if (!pages[j])
+ break;
+ put_page(pages[j]);
+ }
+ ret = -EFAULT;
+ goto out_unmap;
+ }
+
+ offset = offset_in_page(uaddr);
+ for (j = cur_page; j < page_limit; j++) {
+ unsigned int bytes = PAGE_SIZE - offset;
+ unsigned short prev_bi_vcnt = bio->bi_vcnt;
+
+ if (len <= 0)
+ break;
+
+ if (bytes > len)
+ bytes = len;
+
+ /*
+ * sorry...
+ */
+ if (bio_add_pc_page(q, bio, pages[j], bytes, offset) <
+ bytes)
+ break;
+
+ /*
+ * check if vector was merged with previous
+ * drop page reference if needed
+ */
+ if (bio->bi_vcnt == prev_bi_vcnt)
+ put_page(pages[j]);
+
+ len -= bytes;
+ offset = 0;
+ }
+
+ cur_page = j;
+ /*
+ * release the pages we didn't map into the bio, if any
+ */
+ while (j < page_limit)
+ put_page(pages[j++]);
+ }
+
+ kfree(pages);
+
+ bio_set_flag(bio, BIO_USER_MAPPED);
+
+ /*
+ * subtle -- if bio_map_user_iov() ended up bouncing a bio,
+ * it would normally disappear when its bi_end_io is run.
+ * however, we need it for the unmap, so grab an extra
+ * reference to it
+ */
+ bio_get(bio);
+ return bio;
+
+ out_unmap:
+ bio_for_each_segment_all(bvec, bio, j) {
+ put_page(bvec->bv_page);
+ }
+ out:
+ kfree(pages);
+ bio_put(bio);
+ return ERR_PTR(ret);
+}
+
+static void __bio_unmap_user(struct bio *bio)
+{
+ struct bio_vec *bvec;
+ int i;
+
+ /*
+ * make sure we dirty pages we wrote to
+ */
+ bio_for_each_segment_all(bvec, bio, i) {
+ if (bio_data_dir(bio) == READ)
+ set_page_dirty_lock(bvec->bv_page);
+
+ put_page(bvec->bv_page);
+ }
+
+ bio_put(bio);
+}
+
+/**
+ * bio_unmap_user - unmap a bio
+ * @bio: the bio being unmapped
+ *
+ * Unmap a bio previously mapped by bio_map_user_iov(). Must be called from
+ * process context.
+ *
+ * bio_unmap_user() may sleep.
+ */
+void bio_unmap_user(struct bio *bio)
+{
+ __bio_unmap_user(bio);
+ bio_put(bio);
+}
+
+static void bio_map_kern_endio(struct bio *bio)
+{
+ bio_put(bio);
+}
+
+/**
+ * bio_map_kern - map kernel address into bio
+ * @q: the struct request_queue for the bio
+ * @data: pointer to buffer to map
+ * @len: length in bytes
+ * @gfp_mask: allocation flags for bio allocation
+ *
+ * Map the kernel address into a bio suitable for io to a block
+ * device. Returns an error pointer in case of error.
+ */
+struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
+ gfp_t gfp_mask)
+{
+ unsigned long kaddr = (unsigned long)data;
+ unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = kaddr >> PAGE_SHIFT;
+ const int nr_pages = end - start;
+ int offset, i;
+ struct bio *bio;
+
+ bio = bio_kmalloc(gfp_mask, nr_pages);
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ offset = offset_in_page(kaddr);
+ for (i = 0; i < nr_pages; i++) {
+ unsigned int bytes = PAGE_SIZE - offset;
+
+ if (len <= 0)
+ break;
+
+ if (bytes > len)
+ bytes = len;
+
+ if (bio_add_pc_page(q, bio, virt_to_page(data), bytes,
+ offset) < bytes) {
+ /* we don't support partial mappings */
+ bio_put(bio);
+ return ERR_PTR(-EINVAL);
+ }
+
+ data += bytes;
+ len -= bytes;
+ offset = 0;
+ }
+
+ bio->bi_end_io = bio_map_kern_endio;
+ return bio;
+}
+EXPORT_SYMBOL(bio_map_kern);
+
+static void bio_copy_kern_endio(struct bio *bio)
+{
+ bio_free_pages(bio);
+ bio_put(bio);
+}
+
+static void bio_copy_kern_endio_read(struct bio *bio)
+{
+ char *p = bio->bi_private;
+ struct bio_vec *bvec;
+ int i;
+
+ bio_for_each_segment_all(bvec, bio, i) {
+ memcpy(p, page_address(bvec->bv_page), bvec->bv_len);
+ p += bvec->bv_len;
+ }
+
+ bio_copy_kern_endio(bio);
+}
+
+/**
+ * bio_copy_kern - copy kernel address into bio
+ * @q: the struct request_queue for the bio
+ * @data: pointer to buffer to copy
+ * @len: length in bytes
+ * @gfp_mask: allocation flags for bio and page allocation
+ * @reading: data direction is READ
+ *
+ * copy the kernel address into a bio suitable for io to a block
+ * device. Returns an error pointer in case of error.
+ */
+struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
+ gfp_t gfp_mask, int reading)
+{
+ unsigned long kaddr = (unsigned long)data;
+ unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = kaddr >> PAGE_SHIFT;
+ struct bio *bio;
+ void *p = data;
+ int nr_pages = 0;
+
+ /*
+ * Overflow, abort
+ */
+ if (end < start)
+ return ERR_PTR(-EINVAL);
+
+ nr_pages = end - start;
+ bio = bio_kmalloc(gfp_mask, nr_pages);
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ while (len) {
+ struct page *page;
+ unsigned int bytes = PAGE_SIZE;
+
+ if (bytes > len)
+ bytes = len;
+
+ page = alloc_page(q->bounce_gfp | gfp_mask);
+ if (!page)
+ goto cleanup;
+
+ if (!reading)
+ memcpy(page_address(page), p, bytes);
+
+ if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
+ break;
+
+ len -= bytes;
+ p += bytes;
+ }
+
+ if (reading) {
+ bio->bi_end_io = bio_copy_kern_endio_read;
+ bio->bi_private = data;
+ } else {
+ bio->bi_end_io = bio_copy_kern_endio;
+ }
+
+ return bio;
+
+cleanup:
+ bio_free_pages(bio);
+ bio_put(bio);
+ return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
+ * for performing direct-IO in BIOs.
+ *
+ * The problem is that we cannot run set_page_dirty() from interrupt context
+ * because the required locks are not interrupt-safe. So what we can do is to
+ * mark the pages dirty _before_ performing IO. And in interrupt context,
+ * check that the pages are still dirty. If so, fine. If not, redirty them
+ * in process context.
+ *
+ * We special-case compound pages here: normally this means reads into hugetlb
+ * pages. The logic in here doesn't really work right for compound pages
+ * because the VM does not uniformly chase down the head page in all cases.
+ * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't
+ * handle them at all. So we skip compound pages here at an early stage.
+ *
+ * Note that this code is very hard to test under normal circumstances because
+ * direct-io pins the pages with get_user_pages(). This makes
+ * is_page_cache_freeable return false, and the VM will not clean the pages.
+ * But other code (eg, flusher threads) could clean the pages if they are mapped
+ * pagecache.
+ *
+ * Simply disabling the call to bio_set_pages_dirty() is a good way to test the
+ * deferred bio dirtying paths.
+ */
+
+/*
+ * bio_set_pages_dirty() will mark all the bio's pages as dirty.
+ */
+void bio_set_pages_dirty(struct bio *bio)
+{
+ struct bio_vec *bvec;
+ int i;
+
+ bio_for_each_segment_all(bvec, bio, i) {
+ struct page *page = bvec->bv_page;
+
+ if (page && !PageCompound(page))
+ set_page_dirty_lock(page);
+ }
+}
+
+static void bio_release_pages(struct bio *bio)
+{
+ struct bio_vec *bvec;
+ int i;
+
+ bio_for_each_segment_all(bvec, bio, i) {
+ struct page *page = bvec->bv_page;
+
+ if (page)
+ put_page(page);
+ }
+}
+
+/*
+ * bio_check_pages_dirty() will check that all the BIO's pages are still dirty.
+ * If they are, then fine. If, however, some pages are clean then they must
+ * have been written out during the direct-IO read. So we take another ref on
+ * the BIO and the offending pages and re-dirty the pages in process context.
+ *
+ * It is expected that bio_check_pages_dirty() will wholly own the BIO from
+ * here on. It will run one put_page() against each page and will run one
+ * bio_put() against the BIO.
+ */
+
+static void bio_dirty_fn(struct work_struct *work);
+
+static DECLARE_WORK(bio_dirty_work, bio_dirty_fn);
+static DEFINE_SPINLOCK(bio_dirty_lock);
+static struct bio *bio_dirty_list;
+
+/*
+ * This runs in process context
+ */
+static void bio_dirty_fn(struct work_struct *work)
+{
+ unsigned long flags;
+ struct bio *bio;
+
+ spin_lock_irqsave(&bio_dirty_lock, flags);
+ bio = bio_dirty_list;
+ bio_dirty_list = NULL;
+ spin_unlock_irqrestore(&bio_dirty_lock, flags);
+
+ while (bio) {
+ struct bio *next = bio->bi_private;
+
+ bio_set_pages_dirty(bio);
+ bio_release_pages(bio);
+ bio_put(bio);
+ bio = next;
+ }
+}
+
+void bio_check_pages_dirty(struct bio *bio)
+{
+ struct bio_vec *bvec;
+ int nr_clean_pages = 0;
+ int i;
+
+ bio_for_each_segment_all(bvec, bio, i) {
+ struct page *page = bvec->bv_page;
+
+ if (PageDirty(page) || PageCompound(page)) {
+ put_page(page);
+ bvec->bv_page = NULL;
+ } else {
+ nr_clean_pages++;
+ }
+ }
+
+ if (nr_clean_pages) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&bio_dirty_lock, flags);
+ bio->bi_private = bio_dirty_list;
+ bio_dirty_list = bio;
+ spin_unlock_irqrestore(&bio_dirty_lock, flags);
+ schedule_work(&bio_dirty_work);
+ } else {
+ bio_put(bio);
+ }
+}
+
+void generic_start_io_acct(struct request_queue *q, int rw,
+ unsigned long sectors, struct hd_struct *part)
+{
+ int cpu = part_stat_lock();
+
+ part_round_stats(q, cpu, part);
+ part_stat_inc(cpu, part, ios[rw]);
+ part_stat_add(cpu, part, sectors[rw], sectors);
+ part_inc_in_flight(q, part, rw);
+
+ part_stat_unlock();
+}
+EXPORT_SYMBOL(generic_start_io_acct);
+
+void generic_end_io_acct(struct request_queue *q, int rw,
+ struct hd_struct *part, unsigned long start_time)
+{
+ unsigned long duration = jiffies - start_time;
+ int cpu = part_stat_lock();
+
+ part_stat_add(cpu, part, ticks[rw], duration);
+ part_round_stats(q, cpu, part);
+ part_dec_in_flight(q, part, rw);
+
+ part_stat_unlock();
+}
+EXPORT_SYMBOL(generic_end_io_acct);
+
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+void bio_flush_dcache_pages(struct bio *bi)
+{
+ struct bio_vec bvec;
+ struct bvec_iter iter;
+
+ bio_for_each_segment(bvec, bi, iter)
+ flush_dcache_page(bvec.bv_page);
+}
+EXPORT_SYMBOL(bio_flush_dcache_pages);
+#endif
+
+static inline bool bio_remaining_done(struct bio *bio)
+{
+ /*
+ * If we're not chaining, then ->__bi_remaining is always 1 and
+ * we always end io on the first invocation.
+ */
+ if (!bio_flagged(bio, BIO_CHAIN))
+ return true;
+
+ BUG_ON(atomic_read(&bio->__bi_remaining) <= 0);
+
+ if (atomic_dec_and_test(&bio->__bi_remaining)) {
+ bio_clear_flag(bio, BIO_CHAIN);
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * bio_endio - end I/O on a bio
+ * @bio: bio
+ *
+ * Description:
+ * bio_endio() will end I/O on the whole bio. bio_endio() is the preferred
+ * way to end I/O on a bio. No one should call bi_end_io() directly on a
+ * bio unless they own it and thus know that it has an end_io function.
+ *
+ * bio_endio() can be called several times on a bio that has been chained
+ * using bio_chain(). The ->bi_end_io() function will only be called the
+ * last time. At this point the BLK_TA_COMPLETE tracing event will be
+ * generated if BIO_TRACE_COMPLETION is set.
+ **/
+void bio_endio(struct bio *bio)
+{
+again:
+ if (!bio_remaining_done(bio))
+ return;
+ if (!bio_integrity_endio(bio))
+ return;
+
+ /*
+ * Need to have a real endio function for chained bios, otherwise
+ * various corner cases will break (like stacking block devices that
+ * save/restore bi_end_io) - however, we want to avoid unbounded
+ * recursion and blowing the stack. Tail call optimization would
+ * handle this, but compiling with frame pointers also disables
+ * gcc's sibling call optimization.
+ */
+ if (bio->bi_end_io == bio_chain_endio) {
+ bio = __bio_chain_endio(bio);
+ goto again;
+ }
+
+ if (bio->bi_disk && bio_flagged(bio, BIO_TRACE_COMPLETION)) {
+ trace_block_bio_complete(bio->bi_disk->queue, bio,
+ blk_status_to_errno(bio->bi_status));
+ bio_clear_flag(bio, BIO_TRACE_COMPLETION);
+ }
+
+ blk_throtl_bio_endio(bio);
+ /* release cgroup info */
+ bio_uninit(bio);
+ if (bio->bi_end_io)
+ bio->bi_end_io(bio);
+}
+EXPORT_SYMBOL(bio_endio);
+
+/**
+ * bio_split - split a bio
+ * @bio: bio to split
+ * @sectors: number of sectors to split from the front of @bio
+ * @gfp: gfp mask
+ * @bs: bio set to allocate from
+ *
+ * Allocates and returns a new bio which represents @sectors from the start of
+ * @bio, and updates @bio to represent the remaining sectors.
+ *
+ * Unless this is a discard request the newly allocated bio will point
+ * to @bio's bi_io_vec; it is the caller's responsibility to ensure that
+ * @bio is not freed before the split.
+ */
+struct bio *bio_split(struct bio *bio, int sectors,
+ gfp_t gfp, struct bio_set *bs)
+{
+ struct bio *split = NULL;
+
+ BUG_ON(sectors <= 0);
+ BUG_ON(sectors >= bio_sectors(bio));
+
+ split = bio_clone_fast(bio, gfp, bs);
+ if (!split)
+ return NULL;
+
+ split->bi_iter.bi_size = sectors << 9;
+
+ if (bio_integrity(split))
+ bio_integrity_trim(split);
+
+ bio_advance(bio, split->bi_iter.bi_size);
+ bio->bi_iter.bi_done = 0;
+
+ if (bio_flagged(bio, BIO_TRACE_COMPLETION))
+ bio_set_flag(split, BIO_TRACE_COMPLETION);
+
+ return split;
+}
+EXPORT_SYMBOL(bio_split);
+
+/**
+ * bio_trim - trim a bio
+ * @bio: bio to trim
+ * @offset: number of sectors to trim from the front of @bio
+ * @size: size we want to trim @bio to, in sectors
+ */
+void bio_trim(struct bio *bio, int offset, int size)
+{
+ /* 'bio' is a cloned bio which we need to trim to match
+ * the given offset and size.
+ */
+
+ size <<= 9;
+ if (offset == 0 && size == bio->bi_iter.bi_size)
+ return;
+
+ bio_clear_flag(bio, BIO_SEG_VALID);
+
+ bio_advance(bio, offset << 9);
+
+ bio->bi_iter.bi_size = size;
+
+ if (bio_integrity(bio))
+ bio_integrity_trim(bio);
+
+}
+EXPORT_SYMBOL_GPL(bio_trim);
+
+/*
+ * create memory pools for biovec's in a bio_set.
+ * use the global biovec slabs created for general use.
+ */
+mempool_t *biovec_create_pool(int pool_entries)
+{
+ struct biovec_slab *bp = bvec_slabs + BVEC_POOL_MAX;
+
+ return mempool_create_slab_pool(pool_entries, bp->slab);
+}
+
+void bioset_free(struct bio_set *bs)
+{
+ if (bs->rescue_workqueue)
+ destroy_workqueue(bs->rescue_workqueue);
+
+ if (bs->bio_pool)
+ mempool_destroy(bs->bio_pool);
+
+ if (bs->bvec_pool)
+ mempool_destroy(bs->bvec_pool);
+
+ bioset_integrity_free(bs);
+ bio_put_slab(bs);
+
+ kfree(bs);
+}
+EXPORT_SYMBOL(bioset_free);
+
+/**
+ * bioset_create - Create a bio_set
+ * @pool_size: Number of bio and bio_vecs to cache in the mempool
+ * @front_pad: Number of bytes to allocate in front of the returned bio
+ * @flags: Flags to modify behavior, currently %BIOSET_NEED_BVECS
+ * and %BIOSET_NEED_RESCUER
+ *
+ * Description:
+ * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller
+ * to ask for a number of bytes to be allocated in front of the bio.
+ * Front pad allocation is useful for embedding the bio inside
+ * another structure, to avoid allocating extra data to go with the bio.
+ * Note that the bio must be embedded at the END of that structure always,
+ * or things will break badly.
+ * If %BIOSET_NEED_BVECS is set in @flags, a separate pool will be allocated
+ * for allocating iovecs. This pool is not needed e.g. for bio_clone_fast().
+ * If %BIOSET_NEED_RESCUER is set, a workqueue is created which can be used to
+ * dispatch queued requests when the mempool runs out of space.
+ *
+ */
+struct bio_set *bioset_create(unsigned int pool_size,
+ unsigned int front_pad,
+ int flags)
+{
+ unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
+ struct bio_set *bs;
+
+ bs = kzalloc(sizeof(*bs), GFP_KERNEL);
+ if (!bs)
+ return NULL;
+
+ bs->front_pad = front_pad;
+
+ spin_lock_init(&bs->rescue_lock);
+ bio_list_init(&bs->rescue_list);
+ INIT_WORK(&bs->rescue_work, bio_alloc_rescue);
+
+ bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad);
+ if (!bs->bio_slab) {
+ kfree(bs);
+ return NULL;
+ }
+
+ bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab);
+ if (!bs->bio_pool)
+ goto bad;
+
+ if (flags & BIOSET_NEED_BVECS) {
+ bs->bvec_pool = biovec_create_pool(pool_size);
+ if (!bs->bvec_pool)
+ goto bad;
+ }
+
+ if (!(flags & BIOSET_NEED_RESCUER))
+ return bs;
+
+ bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0);
+ if (!bs->rescue_workqueue)
+ goto bad;
+
+ return bs;
+bad:
+ bioset_free(bs);
+ return NULL;
+}
+EXPORT_SYMBOL(bioset_create);
+
+#ifdef CONFIG_BLK_CGROUP
+
+/**
+ * bio_associate_blkcg - associate a bio with the specified blkcg
+ * @bio: target bio
+ * @blkcg_css: css of the blkcg to associate
+ *
+ * Associate @bio with the blkcg specified by @blkcg_css. Block layer will
+ * treat @bio as if it were issued by a task which belongs to the blkcg.
+ *
+ * This function takes an extra reference of @blkcg_css which will be put
+ * when @bio is released. The caller must own @bio and is responsible for
+ * synchronizing calls to this function.
+ */
+int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css)
+{
+ if (unlikely(bio->bi_css))
+ return -EBUSY;
+ css_get(blkcg_css);
+ bio->bi_css = blkcg_css;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(bio_associate_blkcg);
+
+/**
+ * bio_associate_current - associate a bio with %current
+ * @bio: target bio
+ *
+ * Associate @bio with %current if it hasn't been associated yet. Block
+ * layer will treat @bio as if it were issued by %current no matter which
+ * task actually issues it.
+ *
+ * This function takes an extra reference of @task's io_context and blkcg
+ * which will be put when @bio is released. The caller must own @bio,
+ * ensure %current->io_context exists, and is responsible for synchronizing
+ * calls to this function.
+ */
+int bio_associate_current(struct bio *bio)
+{
+ struct io_context *ioc;
+
+ if (bio->bi_css)
+ return -EBUSY;
+
+ ioc = current->io_context;
+ if (!ioc)
+ return -ENOENT;
+
+ get_io_context_active(ioc);
+ bio->bi_ioc = ioc;
+ bio->bi_css = task_get_css(current, io_cgrp_id);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(bio_associate_current);
+
+/**
+ * bio_disassociate_task - undo bio_associate_current()
+ * @bio: target bio
+ */
+void bio_disassociate_task(struct bio *bio)
+{
+ if (bio->bi_ioc) {
+ put_io_context(bio->bi_ioc);
+ bio->bi_ioc = NULL;
+ }
+ if (bio->bi_css) {
+ css_put(bio->bi_css);
+ bio->bi_css = NULL;
+ }
+}
+
+/**
+ * bio_clone_blkcg_association - clone blkcg association from src to dst bio
+ * @dst: destination bio
+ * @src: source bio
+ */
+void bio_clone_blkcg_association(struct bio *dst, struct bio *src)
+{
+ if (src->bi_css)
+ WARN_ON(bio_associate_blkcg(dst, src->bi_css));
+}
+EXPORT_SYMBOL_GPL(bio_clone_blkcg_association);
+#endif /* CONFIG_BLK_CGROUP */
+
+static void __init biovec_init_slabs(void)
+{
+ int i;
+
+ for (i = 0; i < BVEC_POOL_NR; i++) {
+ int size;
+ struct biovec_slab *bvs = bvec_slabs + i;
+
+ if (bvs->nr_vecs <= BIO_INLINE_VECS) {
+ bvs->slab = NULL;
+ continue;
+ }
+
+ size = bvs->nr_vecs * sizeof(struct bio_vec);
+ bvs->slab = kmem_cache_create(bvs->name, size, 0,
+ SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+ }
+}
+
+static int __init init_bio(void)
+{
+ bio_slab_max = 2;
+ bio_slab_nr = 0;
+ bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL);
+ if (!bio_slabs)
+ panic("bio: can't allocate bios\n");
+
+ bio_integrity_init();
+ biovec_init_slabs();
+
+ fs_bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
+ if (!fs_bio_set)
+ panic("bio: can't allocate bios\n");
+
+ if (bioset_integrity_create(fs_bio_set, BIO_POOL_SIZE))
+ panic("bio: can't create integrity pool\n");
+
+ return 0;
+}
+subsys_initcall(init_bio);
diff --git a/src/kernel/linux/v4.14/block/blk-cgroup.c b/src/kernel/linux/v4.14/block/blk-cgroup.c
new file mode 100644
index 0000000..3dc7c0b
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-cgroup.c
@@ -0,0 +1,1509 @@
+/*
+ * Common Block IO controller cgroup interface
+ *
+ * Based on ideas and code from CFQ, CFS and BFQ:
+ * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
+ *
+ * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
+ * Paolo Valente <paolo.valente@unimore.it>
+ *
+ * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
+ * Nauman Rafique <nauman@google.com>
+ *
+ * For policy-specific per-blkcg data:
+ * Copyright (C) 2015 Paolo Valente <paolo.valente@unimore.it>
+ * Arianna Avanzini <avanzini.arianna@gmail.com>
+ */
+#include <linux/ioprio.h>
+#include <linux/kdev_t.h>
+#include <linux/module.h>
+#include <linux/sched/signal.h>
+#include <linux/err.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/slab.h>
+#include <linux/genhd.h>
+#include <linux/delay.h>
+#include <linux/atomic.h>
+#include <linux/ctype.h>
+#include <linux/blk-cgroup.h>
+#include "blk.h"
+
+#define MAX_KEY_LEN 100
+
+/*
+ * blkcg_pol_mutex protects blkcg_policy[] and policy [de]activation.
+ * blkcg_pol_register_mutex nests outside of it and synchronizes entire
+ * policy [un]register operations including cgroup file additions /
+ * removals. Putting cgroup file registration outside blkcg_pol_mutex
+ * allows grabbing it from cgroup callbacks.
+ */
+static DEFINE_MUTEX(blkcg_pol_register_mutex);
+static DEFINE_MUTEX(blkcg_pol_mutex);
+
+struct blkcg blkcg_root;
+EXPORT_SYMBOL_GPL(blkcg_root);
+
+struct cgroup_subsys_state * const blkcg_root_css = &blkcg_root.css;
+
+static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
+
+static LIST_HEAD(all_blkcgs); /* protected by blkcg_pol_mutex */
+
+static bool blkcg_policy_enabled(struct request_queue *q,
+ const struct blkcg_policy *pol)
+{
+ return pol && test_bit(pol->plid, q->blkcg_pols);
+}
+
+/**
+ * blkg_free - free a blkg
+ * @blkg: blkg to free
+ *
+ * Free @blkg which may be partially allocated.
+ */
+static void blkg_free(struct blkcg_gq *blkg)
+{
+ int i;
+
+ if (!blkg)
+ return;
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++)
+ if (blkg->pd[i])
+ blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
+
+ if (blkg->blkcg != &blkcg_root)
+ blk_exit_rl(blkg->q, &blkg->rl);
+
+ blkg_rwstat_exit(&blkg->stat_ios);
+ blkg_rwstat_exit(&blkg->stat_bytes);
+ kfree(blkg);
+}
+
+/**
+ * blkg_alloc - allocate a blkg
+ * @blkcg: block cgroup the new blkg is associated with
+ * @q: request_queue the new blkg is associated with
+ * @gfp_mask: allocation mask to use
+ *
+ * Allocate a new blkg assocating @blkcg and @q.
+ */
+static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
+ gfp_t gfp_mask)
+{
+ struct blkcg_gq *blkg;
+ int i;
+
+ /* alloc and init base part */
+ blkg = kzalloc_node(sizeof(*blkg), gfp_mask, q->node);
+ if (!blkg)
+ return NULL;
+
+ if (blkg_rwstat_init(&blkg->stat_bytes, gfp_mask) ||
+ blkg_rwstat_init(&blkg->stat_ios, gfp_mask))
+ goto err_free;
+
+ blkg->q = q;
+ INIT_LIST_HEAD(&blkg->q_node);
+ blkg->blkcg = blkcg;
+ atomic_set(&blkg->refcnt, 1);
+
+ /* root blkg uses @q->root_rl, init rl only for !root blkgs */
+ if (blkcg != &blkcg_root) {
+ if (blk_init_rl(&blkg->rl, q, gfp_mask))
+ goto err_free;
+ blkg->rl.blkg = blkg;
+ }
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+ struct blkg_policy_data *pd;
+
+ if (!blkcg_policy_enabled(q, pol))
+ continue;
+
+ /* alloc per-policy data and attach it to blkg */
+ pd = pol->pd_alloc_fn(gfp_mask, q->node);
+ if (!pd)
+ goto err_free;
+
+ blkg->pd[i] = pd;
+ pd->blkg = blkg;
+ pd->plid = i;
+ }
+
+ return blkg;
+
+err_free:
+ blkg_free(blkg);
+ return NULL;
+}
+
+struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg,
+ struct request_queue *q, bool update_hint)
+{
+ struct blkcg_gq *blkg;
+
+ /*
+ * Hint didn't match. Look up from the radix tree. Note that the
+ * hint can only be updated under queue_lock as otherwise @blkg
+ * could have already been removed from blkg_tree. The caller is
+ * responsible for grabbing queue_lock if @update_hint.
+ */
+ blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id);
+ if (blkg && blkg->q == q) {
+ if (update_hint) {
+ lockdep_assert_held(q->queue_lock);
+ rcu_assign_pointer(blkcg->blkg_hint, blkg);
+ }
+ return blkg;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(blkg_lookup_slowpath);
+
+/*
+ * If @new_blkg is %NULL, this function tries to allocate a new one as
+ * necessary using %GFP_NOWAIT. @new_blkg is always consumed on return.
+ */
+static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
+ struct request_queue *q,
+ struct blkcg_gq *new_blkg)
+{
+ struct blkcg_gq *blkg;
+ struct bdi_writeback_congested *wb_congested;
+ int i, ret;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ lockdep_assert_held(q->queue_lock);
+
+ /* blkg holds a reference to blkcg */
+ if (!css_tryget_online(&blkcg->css)) {
+ ret = -ENODEV;
+ goto err_free_blkg;
+ }
+
+ wb_congested = wb_congested_get_create(q->backing_dev_info,
+ blkcg->css.id,
+ GFP_NOWAIT | __GFP_NOWARN);
+ if (!wb_congested) {
+ ret = -ENOMEM;
+ goto err_put_css;
+ }
+
+ /* allocate */
+ if (!new_blkg) {
+ new_blkg = blkg_alloc(blkcg, q, GFP_NOWAIT | __GFP_NOWARN);
+ if (unlikely(!new_blkg)) {
+ ret = -ENOMEM;
+ goto err_put_congested;
+ }
+ }
+ blkg = new_blkg;
+ blkg->wb_congested = wb_congested;
+
+ /* link parent */
+ if (blkcg_parent(blkcg)) {
+ blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false);
+ if (WARN_ON_ONCE(!blkg->parent)) {
+ ret = -ENODEV;
+ goto err_put_congested;
+ }
+ blkg_get(blkg->parent);
+ }
+
+ /* invoke per-policy init */
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+
+ if (blkg->pd[i] && pol->pd_init_fn)
+ pol->pd_init_fn(blkg->pd[i]);
+ }
+
+ /* insert */
+ spin_lock(&blkcg->lock);
+ ret = radix_tree_insert(&blkcg->blkg_tree, q->id, blkg);
+ if (likely(!ret)) {
+ hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
+ list_add(&blkg->q_node, &q->blkg_list);
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+
+ if (blkg->pd[i] && pol->pd_online_fn)
+ pol->pd_online_fn(blkg->pd[i]);
+ }
+ }
+ blkg->online = true;
+ spin_unlock(&blkcg->lock);
+
+ if (!ret)
+ return blkg;
+
+ /* @blkg failed fully initialized, use the usual release path */
+ blkg_put(blkg);
+ return ERR_PTR(ret);
+
+err_put_congested:
+ wb_congested_put(wb_congested);
+err_put_css:
+ css_put(&blkcg->css);
+err_free_blkg:
+ blkg_free(new_blkg);
+ return ERR_PTR(ret);
+}
+
+/**
+ * blkg_lookup_create - lookup blkg, try to create one if not there
+ * @blkcg: blkcg of interest
+ * @q: request_queue of interest
+ *
+ * Lookup blkg for the @blkcg - @q pair. If it doesn't exist, try to
+ * create one. blkg creation is performed recursively from blkcg_root such
+ * that all non-root blkg's have access to the parent blkg. This function
+ * should be called under RCU read lock and @q->queue_lock.
+ *
+ * Returns pointer to the looked up or created blkg on success, ERR_PTR()
+ * value on error. If @q is dead, returns ERR_PTR(-EINVAL). If @q is not
+ * dead and bypassing, returns ERR_PTR(-EBUSY).
+ */
+struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
+ struct request_queue *q)
+{
+ struct blkcg_gq *blkg;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ lockdep_assert_held(q->queue_lock);
+
+ /*
+ * This could be the first entry point of blkcg implementation and
+ * we shouldn't allow anything to go through for a bypassing queue.
+ */
+ if (unlikely(blk_queue_bypass(q)))
+ return ERR_PTR(blk_queue_dying(q) ? -ENODEV : -EBUSY);
+
+ blkg = __blkg_lookup(blkcg, q, true);
+ if (blkg)
+ return blkg;
+
+ /*
+ * Create blkgs walking down from blkcg_root to @blkcg, so that all
+ * non-root blkgs have access to their parents.
+ */
+ while (true) {
+ struct blkcg *pos = blkcg;
+ struct blkcg *parent = blkcg_parent(blkcg);
+
+ while (parent && !__blkg_lookup(parent, q, false)) {
+ pos = parent;
+ parent = blkcg_parent(parent);
+ }
+
+ blkg = blkg_create(pos, q, NULL);
+ if (pos == blkcg || IS_ERR(blkg))
+ return blkg;
+ }
+}
+
+static void blkg_destroy(struct blkcg_gq *blkg)
+{
+ struct blkcg *blkcg = blkg->blkcg;
+ struct blkcg_gq *parent = blkg->parent;
+ int i;
+
+ lockdep_assert_held(blkg->q->queue_lock);
+ lockdep_assert_held(&blkcg->lock);
+
+ /* Something wrong if we are trying to remove same group twice */
+ WARN_ON_ONCE(list_empty(&blkg->q_node));
+ WARN_ON_ONCE(hlist_unhashed(&blkg->blkcg_node));
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+
+ if (blkg->pd[i] && pol->pd_offline_fn)
+ pol->pd_offline_fn(blkg->pd[i]);
+ }
+
+ if (parent) {
+ blkg_rwstat_add_aux(&parent->stat_bytes, &blkg->stat_bytes);
+ blkg_rwstat_add_aux(&parent->stat_ios, &blkg->stat_ios);
+ }
+
+ blkg->online = false;
+
+ radix_tree_delete(&blkcg->blkg_tree, blkg->q->id);
+ list_del_init(&blkg->q_node);
+ hlist_del_init_rcu(&blkg->blkcg_node);
+
+ /*
+ * Both setting lookup hint to and clearing it from @blkg are done
+ * under queue_lock. If it's not pointing to @blkg now, it never
+ * will. Hint assignment itself can race safely.
+ */
+ if (rcu_access_pointer(blkcg->blkg_hint) == blkg)
+ rcu_assign_pointer(blkcg->blkg_hint, NULL);
+
+ /*
+ * Put the reference taken at the time of creation so that when all
+ * queues are gone, group can be destroyed.
+ */
+ blkg_put(blkg);
+}
+
+/**
+ * blkg_destroy_all - destroy all blkgs associated with a request_queue
+ * @q: request_queue of interest
+ *
+ * Destroy all blkgs associated with @q.
+ */
+static void blkg_destroy_all(struct request_queue *q)
+{
+ struct blkcg_gq *blkg, *n;
+
+ lockdep_assert_held(q->queue_lock);
+
+ list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) {
+ struct blkcg *blkcg = blkg->blkcg;
+
+ spin_lock(&blkcg->lock);
+ blkg_destroy(blkg);
+ spin_unlock(&blkcg->lock);
+ }
+
+ q->root_blkg = NULL;
+ q->root_rl.blkg = NULL;
+}
+
+/*
+ * A group is RCU protected, but having an rcu lock does not mean that one
+ * can access all the fields of blkg and assume these are valid. For
+ * example, don't try to follow throtl_data and request queue links.
+ *
+ * Having a reference to blkg under an rcu allows accesses to only values
+ * local to groups like group stats and group rate limits.
+ */
+void __blkg_release_rcu(struct rcu_head *rcu_head)
+{
+ struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head);
+
+ /* release the blkcg and parent blkg refs this blkg has been holding */
+ css_put(&blkg->blkcg->css);
+ if (blkg->parent)
+ blkg_put(blkg->parent);
+
+ wb_congested_put(blkg->wb_congested);
+
+ blkg_free(blkg);
+}
+EXPORT_SYMBOL_GPL(__blkg_release_rcu);
+
+/*
+ * The next function used by blk_queue_for_each_rl(). It's a bit tricky
+ * because the root blkg uses @q->root_rl instead of its own rl.
+ */
+struct request_list *__blk_queue_next_rl(struct request_list *rl,
+ struct request_queue *q)
+{
+ struct list_head *ent;
+ struct blkcg_gq *blkg;
+
+ /*
+ * Determine the current blkg list_head. The first entry is
+ * root_rl which is off @q->blkg_list and mapped to the head.
+ */
+ if (rl == &q->root_rl) {
+ ent = &q->blkg_list;
+ /* There are no more block groups, hence no request lists */
+ if (list_empty(ent))
+ return NULL;
+ } else {
+ blkg = container_of(rl, struct blkcg_gq, rl);
+ ent = &blkg->q_node;
+ }
+
+ /* walk to the next list_head, skip root blkcg */
+ ent = ent->next;
+ if (ent == &q->root_blkg->q_node)
+ ent = ent->next;
+ if (ent == &q->blkg_list)
+ return NULL;
+
+ blkg = container_of(ent, struct blkcg_gq, q_node);
+ return &blkg->rl;
+}
+
+static int blkcg_reset_stats(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 val)
+{
+ struct blkcg *blkcg = css_to_blkcg(css);
+ struct blkcg_gq *blkg;
+ int i;
+
+ mutex_lock(&blkcg_pol_mutex);
+ spin_lock_irq(&blkcg->lock);
+
+ /*
+ * Note that stat reset is racy - it doesn't synchronize against
+ * stat updates. This is a debug feature which shouldn't exist
+ * anyway. If you get hit by a race, retry.
+ */
+ hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
+ blkg_rwstat_reset(&blkg->stat_bytes);
+ blkg_rwstat_reset(&blkg->stat_ios);
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+
+ if (blkg->pd[i] && pol->pd_reset_stats_fn)
+ pol->pd_reset_stats_fn(blkg->pd[i]);
+ }
+ }
+
+ spin_unlock_irq(&blkcg->lock);
+ mutex_unlock(&blkcg_pol_mutex);
+ return 0;
+}
+
+const char *blkg_dev_name(struct blkcg_gq *blkg)
+{
+ /* some drivers (floppy) instantiate a queue w/o disk registered */
+ if (blkg->q->backing_dev_info->dev)
+ return dev_name(blkg->q->backing_dev_info->dev);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(blkg_dev_name);
+
+/**
+ * blkcg_print_blkgs - helper for printing per-blkg data
+ * @sf: seq_file to print to
+ * @blkcg: blkcg of interest
+ * @prfill: fill function to print out a blkg
+ * @pol: policy in question
+ * @data: data to be passed to @prfill
+ * @show_total: to print out sum of prfill return values or not
+ *
+ * This function invokes @prfill on each blkg of @blkcg if pd for the
+ * policy specified by @pol exists. @prfill is invoked with @sf, the
+ * policy data and @data and the matching queue lock held. If @show_total
+ * is %true, the sum of the return values from @prfill is printed with
+ * "Total" label at the end.
+ *
+ * This is to be used to construct print functions for
+ * cftype->read_seq_string method.
+ */
+void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
+ u64 (*prfill)(struct seq_file *,
+ struct blkg_policy_data *, int),
+ const struct blkcg_policy *pol, int data,
+ bool show_total)
+{
+ struct blkcg_gq *blkg;
+ u64 total = 0;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
+ spin_lock_irq(blkg->q->queue_lock);
+ if (blkcg_policy_enabled(blkg->q, pol))
+ total += prfill(sf, blkg->pd[pol->plid], data);
+ spin_unlock_irq(blkg->q->queue_lock);
+ }
+ rcu_read_unlock();
+
+ if (show_total)
+ seq_printf(sf, "Total %llu\n", (unsigned long long)total);
+}
+EXPORT_SYMBOL_GPL(blkcg_print_blkgs);
+
+/**
+ * __blkg_prfill_u64 - prfill helper for a single u64 value
+ * @sf: seq_file to print to
+ * @pd: policy private data of interest
+ * @v: value to print
+ *
+ * Print @v to @sf for the device assocaited with @pd.
+ */
+u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v)
+{
+ const char *dname = blkg_dev_name(pd->blkg);
+
+ if (!dname)
+ return 0;
+
+ seq_printf(sf, "%s %llu\n", dname, (unsigned long long)v);
+ return v;
+}
+EXPORT_SYMBOL_GPL(__blkg_prfill_u64);
+
+/**
+ * __blkg_prfill_rwstat - prfill helper for a blkg_rwstat
+ * @sf: seq_file to print to
+ * @pd: policy private data of interest
+ * @rwstat: rwstat to print
+ *
+ * Print @rwstat to @sf for the device assocaited with @pd.
+ */
+u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
+ const struct blkg_rwstat *rwstat)
+{
+ static const char *rwstr[] = {
+ [BLKG_RWSTAT_READ] = "Read",
+ [BLKG_RWSTAT_WRITE] = "Write",
+ [BLKG_RWSTAT_SYNC] = "Sync",
+ [BLKG_RWSTAT_ASYNC] = "Async",
+ };
+ const char *dname = blkg_dev_name(pd->blkg);
+ u64 v;
+ int i;
+
+ if (!dname)
+ return 0;
+
+ for (i = 0; i < BLKG_RWSTAT_NR; i++)
+ seq_printf(sf, "%s %s %llu\n", dname, rwstr[i],
+ (unsigned long long)atomic64_read(&rwstat->aux_cnt[i]));
+
+ v = atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_READ]) +
+ atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_WRITE]);
+ seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)v);
+ return v;
+}
+EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat);
+
+/**
+ * blkg_prfill_stat - prfill callback for blkg_stat
+ * @sf: seq_file to print to
+ * @pd: policy private data of interest
+ * @off: offset to the blkg_stat in @pd
+ *
+ * prfill callback for printing a blkg_stat.
+ */
+u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off)
+{
+ return __blkg_prfill_u64(sf, pd, blkg_stat_read((void *)pd + off));
+}
+EXPORT_SYMBOL_GPL(blkg_prfill_stat);
+
+/**
+ * blkg_prfill_rwstat - prfill callback for blkg_rwstat
+ * @sf: seq_file to print to
+ * @pd: policy private data of interest
+ * @off: offset to the blkg_rwstat in @pd
+ *
+ * prfill callback for printing a blkg_rwstat.
+ */
+u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off)
+{
+ struct blkg_rwstat rwstat = blkg_rwstat_read((void *)pd + off);
+
+ return __blkg_prfill_rwstat(sf, pd, &rwstat);
+}
+EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);
+
+static u64 blkg_prfill_rwstat_field(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct blkg_rwstat rwstat = blkg_rwstat_read((void *)pd->blkg + off);
+
+ return __blkg_prfill_rwstat(sf, pd, &rwstat);
+}
+
+/**
+ * blkg_print_stat_bytes - seq_show callback for blkg->stat_bytes
+ * @sf: seq_file to print to
+ * @v: unused
+ *
+ * To be used as cftype->seq_show to print blkg->stat_bytes.
+ * cftype->private must be set to the blkcg_policy.
+ */
+int blkg_print_stat_bytes(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ blkg_prfill_rwstat_field, (void *)seq_cft(sf)->private,
+ offsetof(struct blkcg_gq, stat_bytes), true);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkg_print_stat_bytes);
+
+/**
+ * blkg_print_stat_bytes - seq_show callback for blkg->stat_ios
+ * @sf: seq_file to print to
+ * @v: unused
+ *
+ * To be used as cftype->seq_show to print blkg->stat_ios. cftype->private
+ * must be set to the blkcg_policy.
+ */
+int blkg_print_stat_ios(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ blkg_prfill_rwstat_field, (void *)seq_cft(sf)->private,
+ offsetof(struct blkcg_gq, stat_ios), true);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkg_print_stat_ios);
+
+static u64 blkg_prfill_rwstat_field_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd,
+ int off)
+{
+ struct blkg_rwstat rwstat = blkg_rwstat_recursive_sum(pd->blkg,
+ NULL, off);
+ return __blkg_prfill_rwstat(sf, pd, &rwstat);
+}
+
+/**
+ * blkg_print_stat_bytes_recursive - recursive version of blkg_print_stat_bytes
+ * @sf: seq_file to print to
+ * @v: unused
+ */
+int blkg_print_stat_bytes_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ blkg_prfill_rwstat_field_recursive,
+ (void *)seq_cft(sf)->private,
+ offsetof(struct blkcg_gq, stat_bytes), true);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkg_print_stat_bytes_recursive);
+
+/**
+ * blkg_print_stat_ios_recursive - recursive version of blkg_print_stat_ios
+ * @sf: seq_file to print to
+ * @v: unused
+ */
+int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ blkg_prfill_rwstat_field_recursive,
+ (void *)seq_cft(sf)->private,
+ offsetof(struct blkcg_gq, stat_ios), true);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkg_print_stat_ios_recursive);
+
+/**
+ * blkg_stat_recursive_sum - collect hierarchical blkg_stat
+ * @blkg: blkg of interest
+ * @pol: blkcg_policy which contains the blkg_stat
+ * @off: offset to the blkg_stat in blkg_policy_data or @blkg
+ *
+ * Collect the blkg_stat specified by @blkg, @pol and @off and all its
+ * online descendants and their aux counts. The caller must be holding the
+ * queue lock for online tests.
+ *
+ * If @pol is NULL, blkg_stat is at @off bytes into @blkg; otherwise, it is
+ * at @off bytes into @blkg's blkg_policy_data of the policy.
+ */
+u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg,
+ struct blkcg_policy *pol, int off)
+{
+ struct blkcg_gq *pos_blkg;
+ struct cgroup_subsys_state *pos_css;
+ u64 sum = 0;
+
+ lockdep_assert_held(blkg->q->queue_lock);
+
+ rcu_read_lock();
+ blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
+ struct blkg_stat *stat;
+
+ if (!pos_blkg->online)
+ continue;
+
+ if (pol)
+ stat = (void *)blkg_to_pd(pos_blkg, pol) + off;
+ else
+ stat = (void *)blkg + off;
+
+ sum += blkg_stat_read(stat) + atomic64_read(&stat->aux_cnt);
+ }
+ rcu_read_unlock();
+
+ return sum;
+}
+EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum);
+
+/**
+ * blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat
+ * @blkg: blkg of interest
+ * @pol: blkcg_policy which contains the blkg_rwstat
+ * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg
+ *
+ * Collect the blkg_rwstat specified by @blkg, @pol and @off and all its
+ * online descendants and their aux counts. The caller must be holding the
+ * queue lock for online tests.
+ *
+ * If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it
+ * is at @off bytes into @blkg's blkg_policy_data of the policy.
+ */
+struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,
+ struct blkcg_policy *pol, int off)
+{
+ struct blkcg_gq *pos_blkg;
+ struct cgroup_subsys_state *pos_css;
+ struct blkg_rwstat sum = { };
+ int i;
+
+ lockdep_assert_held(blkg->q->queue_lock);
+
+ rcu_read_lock();
+ blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
+ struct blkg_rwstat *rwstat;
+
+ if (!pos_blkg->online)
+ continue;
+
+ if (pol)
+ rwstat = (void *)blkg_to_pd(pos_blkg, pol) + off;
+ else
+ rwstat = (void *)pos_blkg + off;
+
+ for (i = 0; i < BLKG_RWSTAT_NR; i++)
+ atomic64_add(atomic64_read(&rwstat->aux_cnt[i]) +
+ percpu_counter_sum_positive(&rwstat->cpu_cnt[i]),
+ &sum.aux_cnt[i]);
+ }
+ rcu_read_unlock();
+
+ return sum;
+}
+EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum);
+
+/* Performs queue bypass and policy enabled checks then looks up blkg. */
+static struct blkcg_gq *blkg_lookup_check(struct blkcg *blkcg,
+ const struct blkcg_policy *pol,
+ struct request_queue *q)
+{
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ lockdep_assert_held(q->queue_lock);
+
+ if (!blkcg_policy_enabled(q, pol))
+ return ERR_PTR(-EOPNOTSUPP);
+
+ /*
+ * This could be the first entry point of blkcg implementation and
+ * we shouldn't allow anything to go through for a bypassing queue.
+ */
+ if (unlikely(blk_queue_bypass(q)))
+ return ERR_PTR(blk_queue_dying(q) ? -ENODEV : -EBUSY);
+
+ return __blkg_lookup(blkcg, q, true /* update_hint */);
+}
+
+/**
+ * blkg_conf_prep - parse and prepare for per-blkg config update
+ * @blkcg: target block cgroup
+ * @pol: target policy
+ * @input: input string
+ * @ctx: blkg_conf_ctx to be filled
+ *
+ * Parse per-blkg config update from @input and initialize @ctx with the
+ * result. @ctx->blkg points to the blkg to be updated and @ctx->body the
+ * part of @input following MAJ:MIN. This function returns with RCU read
+ * lock and queue lock held and must be paired with blkg_conf_finish().
+ */
+int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
+ char *input, struct blkg_conf_ctx *ctx)
+ __acquires(rcu) __acquires(disk->queue->queue_lock)
+{
+ struct gendisk *disk;
+ struct request_queue *q;
+ struct blkcg_gq *blkg;
+ struct module *owner;
+ unsigned int major, minor;
+ int key_len, part, ret;
+ char *body;
+
+ if (sscanf(input, "%u:%u%n", &major, &minor, &key_len) != 2)
+ return -EINVAL;
+
+ body = input + key_len;
+ if (!isspace(*body))
+ return -EINVAL;
+ body = skip_spaces(body);
+
+ disk = get_gendisk(MKDEV(major, minor), &part);
+ if (!disk)
+ return -ENODEV;
+ if (part) {
+ ret = -ENODEV;
+ goto fail;
+ }
+
+ q = disk->queue;
+
+ rcu_read_lock();
+ spin_lock_irq(q->queue_lock);
+
+ blkg = blkg_lookup_check(blkcg, pol, q);
+ if (IS_ERR(blkg)) {
+ ret = PTR_ERR(blkg);
+ goto fail_unlock;
+ }
+
+ if (blkg)
+ goto success;
+
+ /*
+ * Create blkgs walking down from blkcg_root to @blkcg, so that all
+ * non-root blkgs have access to their parents.
+ */
+ while (true) {
+ struct blkcg *pos = blkcg;
+ struct blkcg *parent;
+ struct blkcg_gq *new_blkg;
+
+ parent = blkcg_parent(blkcg);
+ while (parent && !__blkg_lookup(parent, q, false)) {
+ pos = parent;
+ parent = blkcg_parent(parent);
+ }
+
+ /* Drop locks to do new blkg allocation with GFP_KERNEL. */
+ spin_unlock_irq(q->queue_lock);
+ rcu_read_unlock();
+
+ new_blkg = blkg_alloc(pos, q, GFP_KERNEL);
+ if (unlikely(!new_blkg)) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ rcu_read_lock();
+ spin_lock_irq(q->queue_lock);
+
+ blkg = blkg_lookup_check(pos, pol, q);
+ if (IS_ERR(blkg)) {
+ ret = PTR_ERR(blkg);
+ goto fail_unlock;
+ }
+
+ if (blkg) {
+ blkg_free(new_blkg);
+ } else {
+ blkg = blkg_create(pos, q, new_blkg);
+ if (unlikely(IS_ERR(blkg))) {
+ ret = PTR_ERR(blkg);
+ goto fail_unlock;
+ }
+ }
+
+ if (pos == blkcg)
+ goto success;
+ }
+success:
+ ctx->disk = disk;
+ ctx->blkg = blkg;
+ ctx->body = body;
+ return 0;
+
+fail_unlock:
+ spin_unlock_irq(q->queue_lock);
+ rcu_read_unlock();
+fail:
+ owner = disk->fops->owner;
+ put_disk(disk);
+ module_put(owner);
+ /*
+ * If queue was bypassing, we should retry. Do so after a
+ * short msleep(). It isn't strictly necessary but queue
+ * can be bypassing for some time and it's always nice to
+ * avoid busy looping.
+ */
+ if (ret == -EBUSY) {
+ msleep(10);
+ ret = restart_syscall();
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blkg_conf_prep);
+
+/**
+ * blkg_conf_finish - finish up per-blkg config update
+ * @ctx: blkg_conf_ctx intiailized by blkg_conf_prep()
+ *
+ * Finish up after per-blkg config update. This function must be paired
+ * with blkg_conf_prep().
+ */
+void blkg_conf_finish(struct blkg_conf_ctx *ctx)
+ __releases(ctx->disk->queue->queue_lock) __releases(rcu)
+{
+ struct module *owner;
+
+ spin_unlock_irq(ctx->disk->queue->queue_lock);
+ rcu_read_unlock();
+ owner = ctx->disk->fops->owner;
+ put_disk(ctx->disk);
+ module_put(owner);
+}
+EXPORT_SYMBOL_GPL(blkg_conf_finish);
+
+static int blkcg_print_stat(struct seq_file *sf, void *v)
+{
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct blkcg_gq *blkg;
+
+ rcu_read_lock();
+
+ hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
+ const char *dname;
+ struct blkg_rwstat rwstat;
+ u64 rbytes, wbytes, rios, wios;
+
+ dname = blkg_dev_name(blkg);
+ if (!dname)
+ continue;
+
+ spin_lock_irq(blkg->q->queue_lock);
+
+ rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
+ offsetof(struct blkcg_gq, stat_bytes));
+ rbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
+ wbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
+
+ rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
+ offsetof(struct blkcg_gq, stat_ios));
+ rios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
+ wios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
+
+ spin_unlock_irq(blkg->q->queue_lock);
+
+ if (rbytes || wbytes || rios || wios)
+ seq_printf(sf, "%s rbytes=%llu wbytes=%llu rios=%llu wios=%llu\n",
+ dname, rbytes, wbytes, rios, wios);
+ }
+
+ rcu_read_unlock();
+ return 0;
+}
+
+static struct cftype blkcg_files[] = {
+ {
+ .name = "stat",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = blkcg_print_stat,
+ },
+ { } /* terminate */
+};
+
+static struct cftype blkcg_legacy_files[] = {
+ {
+ .name = "reset_stats",
+ .write_u64 = blkcg_reset_stats,
+ },
+ { } /* terminate */
+};
+
+/**
+ * blkcg_css_offline - cgroup css_offline callback
+ * @css: css of interest
+ *
+ * This function is called when @css is about to go away and responsible
+ * for shooting down all blkgs associated with @css. blkgs should be
+ * removed while holding both q and blkcg locks. As blkcg lock is nested
+ * inside q lock, this function performs reverse double lock dancing.
+ *
+ * This is the blkcg counterpart of ioc_release_fn().
+ */
+static void blkcg_css_offline(struct cgroup_subsys_state *css)
+{
+ struct blkcg *blkcg = css_to_blkcg(css);
+
+ spin_lock_irq(&blkcg->lock);
+
+ while (!hlist_empty(&blkcg->blkg_list)) {
+ struct blkcg_gq *blkg = hlist_entry(blkcg->blkg_list.first,
+ struct blkcg_gq, blkcg_node);
+ struct request_queue *q = blkg->q;
+
+ if (spin_trylock(q->queue_lock)) {
+ blkg_destroy(blkg);
+ spin_unlock(q->queue_lock);
+ } else {
+ spin_unlock_irq(&blkcg->lock);
+ cpu_relax();
+ spin_lock_irq(&blkcg->lock);
+ }
+ }
+
+ spin_unlock_irq(&blkcg->lock);
+
+ wb_blkcg_offline(blkcg);
+}
+
+static void blkcg_css_free(struct cgroup_subsys_state *css)
+{
+ struct blkcg *blkcg = css_to_blkcg(css);
+ int i;
+
+ mutex_lock(&blkcg_pol_mutex);
+
+ list_del(&blkcg->all_blkcgs_node);
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++)
+ if (blkcg->cpd[i])
+ blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]);
+
+ mutex_unlock(&blkcg_pol_mutex);
+
+ kfree(blkcg);
+}
+
+static struct cgroup_subsys_state *
+blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
+{
+ struct blkcg *blkcg;
+ struct cgroup_subsys_state *ret;
+ int i;
+
+ mutex_lock(&blkcg_pol_mutex);
+
+ if (!parent_css) {
+ blkcg = &blkcg_root;
+ } else {
+ blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
+ if (!blkcg) {
+ ret = ERR_PTR(-ENOMEM);
+ goto unlock;
+ }
+ }
+
+ for (i = 0; i < BLKCG_MAX_POLS ; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+ struct blkcg_policy_data *cpd;
+
+ /*
+ * If the policy hasn't been attached yet, wait for it
+ * to be attached before doing anything else. Otherwise,
+ * check if the policy requires any specific per-cgroup
+ * data: if it does, allocate and initialize it.
+ */
+ if (!pol || !pol->cpd_alloc_fn)
+ continue;
+
+ cpd = pol->cpd_alloc_fn(GFP_KERNEL);
+ if (!cpd) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_pd_blkcg;
+ }
+ blkcg->cpd[i] = cpd;
+ cpd->blkcg = blkcg;
+ cpd->plid = i;
+ if (pol->cpd_init_fn)
+ pol->cpd_init_fn(cpd);
+ }
+
+ spin_lock_init(&blkcg->lock);
+ INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT | __GFP_NOWARN);
+ INIT_HLIST_HEAD(&blkcg->blkg_list);
+#ifdef CONFIG_CGROUP_WRITEBACK
+ INIT_LIST_HEAD(&blkcg->cgwb_list);
+#endif
+ list_add_tail(&blkcg->all_blkcgs_node, &all_blkcgs);
+
+ mutex_unlock(&blkcg_pol_mutex);
+ return &blkcg->css;
+
+free_pd_blkcg:
+ for (i--; i >= 0; i--)
+ if (blkcg->cpd[i])
+ blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]);
+
+ if (blkcg != &blkcg_root)
+ kfree(blkcg);
+unlock:
+ mutex_unlock(&blkcg_pol_mutex);
+ return ret;
+}
+
+/**
+ * blkcg_init_queue - initialize blkcg part of request queue
+ * @q: request_queue to initialize
+ *
+ * Called from blk_alloc_queue_node(). Responsible for initializing blkcg
+ * part of new request_queue @q.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int blkcg_init_queue(struct request_queue *q)
+{
+ struct blkcg_gq *new_blkg, *blkg;
+ bool preloaded;
+ int ret;
+
+ new_blkg = blkg_alloc(&blkcg_root, q, GFP_KERNEL);
+ if (!new_blkg)
+ return -ENOMEM;
+
+ preloaded = !radix_tree_preload(GFP_KERNEL);
+
+ /*
+ * Make sure the root blkg exists and count the existing blkgs. As
+ * @q is bypassing at this point, blkg_lookup_create() can't be
+ * used. Open code insertion.
+ */
+ rcu_read_lock();
+ spin_lock_irq(q->queue_lock);
+ blkg = blkg_create(&blkcg_root, q, new_blkg);
+ if (IS_ERR(blkg))
+ goto err_unlock;
+ q->root_blkg = blkg;
+ q->root_rl.blkg = blkg;
+ spin_unlock_irq(q->queue_lock);
+ rcu_read_unlock();
+
+ if (preloaded)
+ radix_tree_preload_end();
+
+ ret = blk_throtl_init(q);
+ if (ret) {
+ spin_lock_irq(q->queue_lock);
+ blkg_destroy_all(q);
+ spin_unlock_irq(q->queue_lock);
+ }
+ return ret;
+
+err_unlock:
+ spin_unlock_irq(q->queue_lock);
+ rcu_read_unlock();
+ if (preloaded)
+ radix_tree_preload_end();
+ return PTR_ERR(blkg);
+}
+
+/**
+ * blkcg_drain_queue - drain blkcg part of request_queue
+ * @q: request_queue to drain
+ *
+ * Called from blk_drain_queue(). Responsible for draining blkcg part.
+ */
+void blkcg_drain_queue(struct request_queue *q)
+{
+ lockdep_assert_held(q->queue_lock);
+
+ /*
+ * @q could be exiting and already have destroyed all blkgs as
+ * indicated by NULL root_blkg. If so, don't confuse policies.
+ */
+ if (!q->root_blkg)
+ return;
+
+ blk_throtl_drain(q);
+}
+
+/**
+ * blkcg_exit_queue - exit and release blkcg part of request_queue
+ * @q: request_queue being released
+ *
+ * Called from blk_release_queue(). Responsible for exiting blkcg part.
+ */
+void blkcg_exit_queue(struct request_queue *q)
+{
+ spin_lock_irq(q->queue_lock);
+ blkg_destroy_all(q);
+ spin_unlock_irq(q->queue_lock);
+
+ blk_throtl_exit(q);
+}
+
+/*
+ * We cannot support shared io contexts, as we have no mean to support
+ * two tasks with the same ioc in two different groups without major rework
+ * of the main cic data structures. For now we allow a task to change
+ * its cgroup only if it's the only owner of its ioc.
+ */
+static int blkcg_can_attach(struct cgroup_taskset *tset)
+{
+ struct task_struct *task;
+ struct cgroup_subsys_state *dst_css;
+ struct io_context *ioc;
+ int ret = 0;
+
+ /* task_lock() is needed to avoid races with exit_io_context() */
+ cgroup_taskset_for_each(task, dst_css, tset) {
+ task_lock(task);
+ ioc = task->io_context;
+ if (ioc && atomic_read(&ioc->nr_tasks) > 1)
+ ret = -EINVAL;
+ task_unlock(task);
+ if (ret)
+ break;
+ }
+ return ret;
+}
+
+static void blkcg_bind(struct cgroup_subsys_state *root_css)
+{
+ int i;
+
+ mutex_lock(&blkcg_pol_mutex);
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+ struct blkcg *blkcg;
+
+ if (!pol || !pol->cpd_bind_fn)
+ continue;
+
+ list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node)
+ if (blkcg->cpd[pol->plid])
+ pol->cpd_bind_fn(blkcg->cpd[pol->plid]);
+ }
+ mutex_unlock(&blkcg_pol_mutex);
+}
+
+struct cgroup_subsys io_cgrp_subsys = {
+ .css_alloc = blkcg_css_alloc,
+ .css_offline = blkcg_css_offline,
+ .css_free = blkcg_css_free,
+ .can_attach = blkcg_can_attach,
+ .bind = blkcg_bind,
+ .dfl_cftypes = blkcg_files,
+ .legacy_cftypes = blkcg_legacy_files,
+ .legacy_name = "blkio",
+#ifdef CONFIG_MEMCG
+ /*
+ * This ensures that, if available, memcg is automatically enabled
+ * together on the default hierarchy so that the owner cgroup can
+ * be retrieved from writeback pages.
+ */
+ .depends_on = 1 << memory_cgrp_id,
+#endif
+};
+EXPORT_SYMBOL_GPL(io_cgrp_subsys);
+
+/**
+ * blkcg_activate_policy - activate a blkcg policy on a request_queue
+ * @q: request_queue of interest
+ * @pol: blkcg policy to activate
+ *
+ * Activate @pol on @q. Requires %GFP_KERNEL context. @q goes through
+ * bypass mode to populate its blkgs with policy_data for @pol.
+ *
+ * Activation happens with @q bypassed, so nobody would be accessing blkgs
+ * from IO path. Update of each blkg is protected by both queue and blkcg
+ * locks so that holding either lock and testing blkcg_policy_enabled() is
+ * always enough for dereferencing policy data.
+ *
+ * The caller is responsible for synchronizing [de]activations and policy
+ * [un]registerations. Returns 0 on success, -errno on failure.
+ */
+int blkcg_activate_policy(struct request_queue *q,
+ const struct blkcg_policy *pol)
+{
+ struct blkg_policy_data *pd_prealloc = NULL;
+ struct blkcg_gq *blkg;
+ int ret;
+
+ if (blkcg_policy_enabled(q, pol))
+ return 0;
+
+ if (q->mq_ops)
+ blk_mq_freeze_queue(q);
+ else
+ blk_queue_bypass_start(q);
+pd_prealloc:
+ if (!pd_prealloc) {
+ pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q->node);
+ if (!pd_prealloc) {
+ ret = -ENOMEM;
+ goto out_bypass_end;
+ }
+ }
+
+ spin_lock_irq(q->queue_lock);
+
+ list_for_each_entry(blkg, &q->blkg_list, q_node) {
+ struct blkg_policy_data *pd;
+
+ if (blkg->pd[pol->plid])
+ continue;
+
+ pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q->node);
+ if (!pd)
+ swap(pd, pd_prealloc);
+ if (!pd) {
+ spin_unlock_irq(q->queue_lock);
+ goto pd_prealloc;
+ }
+
+ blkg->pd[pol->plid] = pd;
+ pd->blkg = blkg;
+ pd->plid = pol->plid;
+ if (pol->pd_init_fn)
+ pol->pd_init_fn(pd);
+ }
+
+ __set_bit(pol->plid, q->blkcg_pols);
+ ret = 0;
+
+ spin_unlock_irq(q->queue_lock);
+out_bypass_end:
+ if (q->mq_ops)
+ blk_mq_unfreeze_queue(q);
+ else
+ blk_queue_bypass_end(q);
+ if (pd_prealloc)
+ pol->pd_free_fn(pd_prealloc);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blkcg_activate_policy);
+
+/**
+ * blkcg_deactivate_policy - deactivate a blkcg policy on a request_queue
+ * @q: request_queue of interest
+ * @pol: blkcg policy to deactivate
+ *
+ * Deactivate @pol on @q. Follows the same synchronization rules as
+ * blkcg_activate_policy().
+ */
+void blkcg_deactivate_policy(struct request_queue *q,
+ const struct blkcg_policy *pol)
+{
+ struct blkcg_gq *blkg;
+
+ if (!blkcg_policy_enabled(q, pol))
+ return;
+
+ if (q->mq_ops)
+ blk_mq_freeze_queue(q);
+ else
+ blk_queue_bypass_start(q);
+
+ spin_lock_irq(q->queue_lock);
+
+ __clear_bit(pol->plid, q->blkcg_pols);
+
+ list_for_each_entry(blkg, &q->blkg_list, q_node) {
+ if (blkg->pd[pol->plid]) {
+ if (pol->pd_offline_fn)
+ pol->pd_offline_fn(blkg->pd[pol->plid]);
+ pol->pd_free_fn(blkg->pd[pol->plid]);
+ blkg->pd[pol->plid] = NULL;
+ }
+ }
+
+ spin_unlock_irq(q->queue_lock);
+
+ if (q->mq_ops)
+ blk_mq_unfreeze_queue(q);
+ else
+ blk_queue_bypass_end(q);
+}
+EXPORT_SYMBOL_GPL(blkcg_deactivate_policy);
+
+/**
+ * blkcg_policy_register - register a blkcg policy
+ * @pol: blkcg policy to register
+ *
+ * Register @pol with blkcg core. Might sleep and @pol may be modified on
+ * successful registration. Returns 0 on success and -errno on failure.
+ */
+int blkcg_policy_register(struct blkcg_policy *pol)
+{
+ struct blkcg *blkcg;
+ int i, ret;
+
+ mutex_lock(&blkcg_pol_register_mutex);
+ mutex_lock(&blkcg_pol_mutex);
+
+ /* find an empty slot */
+ ret = -ENOSPC;
+ for (i = 0; i < BLKCG_MAX_POLS; i++)
+ if (!blkcg_policy[i])
+ break;
+ if (i >= BLKCG_MAX_POLS)
+ goto err_unlock;
+
+ /* register @pol */
+ pol->plid = i;
+ blkcg_policy[pol->plid] = pol;
+
+ /* allocate and install cpd's */
+ if (pol->cpd_alloc_fn) {
+ list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
+ struct blkcg_policy_data *cpd;
+
+ cpd = pol->cpd_alloc_fn(GFP_KERNEL);
+ if (!cpd)
+ goto err_free_cpds;
+
+ blkcg->cpd[pol->plid] = cpd;
+ cpd->blkcg = blkcg;
+ cpd->plid = pol->plid;
+ pol->cpd_init_fn(cpd);
+ }
+ }
+
+ mutex_unlock(&blkcg_pol_mutex);
+
+ /* everything is in place, add intf files for the new policy */
+ if (pol->dfl_cftypes)
+ WARN_ON(cgroup_add_dfl_cftypes(&io_cgrp_subsys,
+ pol->dfl_cftypes));
+ if (pol->legacy_cftypes)
+ WARN_ON(cgroup_add_legacy_cftypes(&io_cgrp_subsys,
+ pol->legacy_cftypes));
+ mutex_unlock(&blkcg_pol_register_mutex);
+ return 0;
+
+err_free_cpds:
+ if (pol->cpd_alloc_fn) {
+ list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
+ if (blkcg->cpd[pol->plid]) {
+ pol->cpd_free_fn(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
+ }
+ }
+ }
+ blkcg_policy[pol->plid] = NULL;
+err_unlock:
+ mutex_unlock(&blkcg_pol_mutex);
+ mutex_unlock(&blkcg_pol_register_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blkcg_policy_register);
+
+/**
+ * blkcg_policy_unregister - unregister a blkcg policy
+ * @pol: blkcg policy to unregister
+ *
+ * Undo blkcg_policy_register(@pol). Might sleep.
+ */
+void blkcg_policy_unregister(struct blkcg_policy *pol)
+{
+ struct blkcg *blkcg;
+
+ mutex_lock(&blkcg_pol_register_mutex);
+
+ if (WARN_ON(blkcg_policy[pol->plid] != pol))
+ goto out_unlock;
+
+ /* kill the intf files first */
+ if (pol->dfl_cftypes)
+ cgroup_rm_cftypes(pol->dfl_cftypes);
+ if (pol->legacy_cftypes)
+ cgroup_rm_cftypes(pol->legacy_cftypes);
+
+ /* remove cpds and unregister */
+ mutex_lock(&blkcg_pol_mutex);
+
+ if (pol->cpd_alloc_fn) {
+ list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
+ if (blkcg->cpd[pol->plid]) {
+ pol->cpd_free_fn(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
+ }
+ }
+ }
+ blkcg_policy[pol->plid] = NULL;
+
+ mutex_unlock(&blkcg_pol_mutex);
+out_unlock:
+ mutex_unlock(&blkcg_pol_register_mutex);
+}
+EXPORT_SYMBOL_GPL(blkcg_policy_unregister);
diff --git a/src/kernel/linux/v4.14/block/blk-core.c b/src/kernel/linux/v4.14/block/blk-core.c
new file mode 100644
index 0000000..2407c89
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-core.c
@@ -0,0 +1,3652 @@
+/*
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright (C) 1994, Karl Keyte: Added support for disk statistics
+ * Elevator latency, (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
+ * Queue request tables / lock, selectable elevator, Jens Axboe <axboe@suse.de>
+ * kernel-doc documentation started by NeilBrown <neilb@cse.unsw.edu.au>
+ * - July2000
+ * bio rewrite, highmem i/o, etc, Jens Axboe <axboe@suse.de> - may 2001
+ */
+
+/*
+ * This handles all read/write requests to block devices
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/backing-dev.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/kernel_stat.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/fault-inject.h>
+#include <linux/list_sort.h>
+#include <linux/delay.h>
+#include <linux/ratelimit.h>
+#include <linux/pm_runtime.h>
+#include <linux/blk-cgroup.h>
+#include <linux/debugfs.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/block.h>
+
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-sched.h"
+#include "blk-wbt.h"
+
+#ifdef CONFIG_DEBUG_FS
+struct dentry *blk_debugfs_root;
+#endif
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
+EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
+EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
+EXPORT_TRACEPOINT_SYMBOL_GPL(block_split);
+EXPORT_TRACEPOINT_SYMBOL_GPL(block_unplug);
+
+DEFINE_IDA(blk_queue_ida);
+
+/*
+ * For the allocated request tables
+ */
+struct kmem_cache *request_cachep;
+
+/*
+ * For queue allocation
+ */
+struct kmem_cache *blk_requestq_cachep;
+
+/*
+ * Controlling structure to kblockd
+ */
+static struct workqueue_struct *kblockd_workqueue;
+
+static void blk_clear_congested(struct request_list *rl, int sync)
+{
+#ifdef CONFIG_CGROUP_WRITEBACK
+ clear_wb_congested(rl->blkg->wb_congested, sync);
+#else
+ /*
+ * If !CGROUP_WRITEBACK, all blkg's map to bdi->wb and we shouldn't
+ * flip its congestion state for events on other blkcgs.
+ */
+ if (rl == &rl->q->root_rl)
+ clear_wb_congested(rl->q->backing_dev_info->wb.congested, sync);
+#endif
+}
+
+static void blk_set_congested(struct request_list *rl, int sync)
+{
+#ifdef CONFIG_CGROUP_WRITEBACK
+ set_wb_congested(rl->blkg->wb_congested, sync);
+#else
+ /* see blk_clear_congested() */
+ if (rl == &rl->q->root_rl)
+ set_wb_congested(rl->q->backing_dev_info->wb.congested, sync);
+#endif
+}
+
+void blk_queue_congestion_threshold(struct request_queue *q)
+{
+ int nr;
+
+ nr = q->nr_requests - (q->nr_requests / 8) + 1;
+ if (nr > q->nr_requests)
+ nr = q->nr_requests;
+ q->nr_congestion_on = nr;
+
+ nr = q->nr_requests - (q->nr_requests / 8) - (q->nr_requests / 16) - 1;
+ if (nr < 1)
+ nr = 1;
+ q->nr_congestion_off = nr;
+}
+
+void blk_rq_init(struct request_queue *q, struct request *rq)
+{
+ memset(rq, 0, sizeof(*rq));
+
+ INIT_LIST_HEAD(&rq->queuelist);
+ INIT_LIST_HEAD(&rq->timeout_list);
+ rq->cpu = -1;
+ rq->q = q;
+ rq->__sector = (sector_t) -1;
+ INIT_HLIST_NODE(&rq->hash);
+ RB_CLEAR_NODE(&rq->rb_node);
+ rq->tag = -1;
+ rq->internal_tag = -1;
+ rq->start_time = jiffies;
+ set_start_time_ns(rq);
+ rq->part = NULL;
+}
+EXPORT_SYMBOL(blk_rq_init);
+
+static const struct {
+ int errno;
+ const char *name;
+} blk_errors[] = {
+ [BLK_STS_OK] = { 0, "" },
+ [BLK_STS_NOTSUPP] = { -EOPNOTSUPP, "operation not supported" },
+ [BLK_STS_TIMEOUT] = { -ETIMEDOUT, "timeout" },
+ [BLK_STS_NOSPC] = { -ENOSPC, "critical space allocation" },
+ [BLK_STS_TRANSPORT] = { -ENOLINK, "recoverable transport" },
+ [BLK_STS_TARGET] = { -EREMOTEIO, "critical target" },
+ [BLK_STS_NEXUS] = { -EBADE, "critical nexus" },
+ [BLK_STS_MEDIUM] = { -ENODATA, "critical medium" },
+ [BLK_STS_PROTECTION] = { -EILSEQ, "protection" },
+ [BLK_STS_RESOURCE] = { -ENOMEM, "kernel resource" },
+ [BLK_STS_AGAIN] = { -EAGAIN, "nonblocking retry" },
+
+ /* device mapper special case, should not leak out: */
+ [BLK_STS_DM_REQUEUE] = { -EREMCHG, "dm internal retry" },
+
+ /* everything else not covered above: */
+ [BLK_STS_IOERR] = { -EIO, "I/O" },
+};
+
+blk_status_t errno_to_blk_status(int errno)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(blk_errors); i++) {
+ if (blk_errors[i].errno == errno)
+ return (__force blk_status_t)i;
+ }
+
+ return BLK_STS_IOERR;
+}
+EXPORT_SYMBOL_GPL(errno_to_blk_status);
+
+int blk_status_to_errno(blk_status_t status)
+{
+ int idx = (__force int)status;
+
+ if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors)))
+ return -EIO;
+ return blk_errors[idx].errno;
+}
+EXPORT_SYMBOL_GPL(blk_status_to_errno);
+
+static void print_req_error(struct request *req, blk_status_t status)
+{
+ int idx = (__force int)status;
+
+ if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors)))
+ return;
+
+ printk_ratelimited(KERN_ERR "%s: %s error, dev %s, sector %llu\n",
+ __func__, blk_errors[idx].name, req->rq_disk ?
+ req->rq_disk->disk_name : "?",
+ (unsigned long long)blk_rq_pos(req));
+}
+
+static void req_bio_endio(struct request *rq, struct bio *bio,
+ unsigned int nbytes, blk_status_t error)
+{
+ if (error)
+ bio->bi_status = error;
+
+ if (unlikely(rq->rq_flags & RQF_QUIET))
+ bio_set_flag(bio, BIO_QUIET);
+
+ bio_advance(bio, nbytes);
+
+ /* don't actually finish bio if it's part of flush sequence */
+ if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ))
+ bio_endio(bio);
+}
+
+void blk_dump_rq_flags(struct request *rq, char *msg)
+{
+ printk(KERN_INFO "%s: dev %s: flags=%llx\n", msg,
+ rq->rq_disk ? rq->rq_disk->disk_name : "?",
+ (unsigned long long) rq->cmd_flags);
+
+ printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n",
+ (unsigned long long)blk_rq_pos(rq),
+ blk_rq_sectors(rq), blk_rq_cur_sectors(rq));
+ printk(KERN_INFO " bio %p, biotail %p, len %u\n",
+ rq->bio, rq->biotail, blk_rq_bytes(rq));
+}
+EXPORT_SYMBOL(blk_dump_rq_flags);
+
+static void blk_delay_work(struct work_struct *work)
+{
+ struct request_queue *q;
+
+ q = container_of(work, struct request_queue, delay_work.work);
+ spin_lock_irq(q->queue_lock);
+ __blk_run_queue(q);
+ spin_unlock_irq(q->queue_lock);
+}
+
+/**
+ * blk_delay_queue - restart queueing after defined interval
+ * @q: The &struct request_queue in question
+ * @msecs: Delay in msecs
+ *
+ * Description:
+ * Sometimes queueing needs to be postponed for a little while, to allow
+ * resources to come back. This function will make sure that queueing is
+ * restarted around the specified time.
+ */
+void blk_delay_queue(struct request_queue *q, unsigned long msecs)
+{
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ if (likely(!blk_queue_dead(q)))
+ queue_delayed_work(kblockd_workqueue, &q->delay_work,
+ msecs_to_jiffies(msecs));
+}
+EXPORT_SYMBOL(blk_delay_queue);
+
+/**
+ * blk_start_queue_async - asynchronously restart a previously stopped queue
+ * @q: The &struct request_queue in question
+ *
+ * Description:
+ * blk_start_queue_async() will clear the stop flag on the queue, and
+ * ensure that the request_fn for the queue is run from an async
+ * context.
+ **/
+void blk_start_queue_async(struct request_queue *q)
+{
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ queue_flag_clear(QUEUE_FLAG_STOPPED, q);
+ blk_run_queue_async(q);
+}
+EXPORT_SYMBOL(blk_start_queue_async);
+
+/**
+ * blk_start_queue - restart a previously stopped queue
+ * @q: The &struct request_queue in question
+ *
+ * Description:
+ * blk_start_queue() will clear the stop flag on the queue, and call
+ * the request_fn for the queue if it was in a stopped state when
+ * entered. Also see blk_stop_queue().
+ **/
+void blk_start_queue(struct request_queue *q)
+{
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON(!in_interrupt() && !irqs_disabled());
+ WARN_ON_ONCE(q->mq_ops);
+
+ queue_flag_clear(QUEUE_FLAG_STOPPED, q);
+ __blk_run_queue(q);
+}
+EXPORT_SYMBOL(blk_start_queue);
+
+/**
+ * blk_stop_queue - stop a queue
+ * @q: The &struct request_queue in question
+ *
+ * Description:
+ * The Linux block layer assumes that a block driver will consume all
+ * entries on the request queue when the request_fn strategy is called.
+ * Often this will not happen, because of hardware limitations (queue
+ * depth settings). If a device driver gets a 'queue full' response,
+ * or if it simply chooses not to queue more I/O at one point, it can
+ * call this function to prevent the request_fn from being called until
+ * the driver has signalled it's ready to go again. This happens by calling
+ * blk_start_queue() to restart queue operations.
+ **/
+void blk_stop_queue(struct request_queue *q)
+{
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ cancel_delayed_work(&q->delay_work);
+ queue_flag_set(QUEUE_FLAG_STOPPED, q);
+}
+EXPORT_SYMBOL(blk_stop_queue);
+
+/**
+ * blk_sync_queue - cancel any pending callbacks on a queue
+ * @q: the queue
+ *
+ * Description:
+ * The block layer may perform asynchronous callback activity
+ * on a queue, such as calling the unplug function after a timeout.
+ * A block device may call blk_sync_queue to ensure that any
+ * such activity is cancelled, thus allowing it to release resources
+ * that the callbacks might use. The caller must already have made sure
+ * that its ->make_request_fn will not re-add plugging prior to calling
+ * this function.
+ *
+ * This function does not cancel any asynchronous activity arising
+ * out of elevator or throttling code. That would require elevator_exit()
+ * and blkcg_exit_queue() to be called with queue lock initialized.
+ *
+ */
+void blk_sync_queue(struct request_queue *q)
+{
+ del_timer_sync(&q->timeout);
+ cancel_work_sync(&q->timeout_work);
+
+ if (q->mq_ops) {
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ cancel_delayed_work_sync(&hctx->run_work);
+ } else {
+ cancel_delayed_work_sync(&q->delay_work);
+ }
+}
+EXPORT_SYMBOL(blk_sync_queue);
+
+/**
+ * __blk_run_queue_uncond - run a queue whether or not it has been stopped
+ * @q: The queue to run
+ *
+ * Description:
+ * Invoke request handling on a queue if there are any pending requests.
+ * May be used to restart request handling after a request has completed.
+ * This variant runs the queue whether or not the queue has been
+ * stopped. Must be called with the queue lock held and interrupts
+ * disabled. See also @blk_run_queue.
+ */
+inline void __blk_run_queue_uncond(struct request_queue *q)
+{
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ if (unlikely(blk_queue_dead(q)))
+ return;
+
+ /*
+ * Some request_fn implementations, e.g. scsi_request_fn(), unlock
+ * the queue lock internally. As a result multiple threads may be
+ * running such a request function concurrently. Keep track of the
+ * number of active request_fn invocations such that blk_drain_queue()
+ * can wait until all these request_fn calls have finished.
+ */
+ q->request_fn_active++;
+ q->request_fn(q);
+ q->request_fn_active--;
+}
+EXPORT_SYMBOL_GPL(__blk_run_queue_uncond);
+
+/**
+ * __blk_run_queue - run a single device queue
+ * @q: The queue to run
+ *
+ * Description:
+ * See @blk_run_queue.
+ */
+void __blk_run_queue(struct request_queue *q)
+{
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ if (unlikely(blk_queue_stopped(q)))
+ return;
+
+ __blk_run_queue_uncond(q);
+}
+EXPORT_SYMBOL(__blk_run_queue);
+
+/**
+ * blk_run_queue_async - run a single device queue in workqueue context
+ * @q: The queue to run
+ *
+ * Description:
+ * Tells kblockd to perform the equivalent of @blk_run_queue on behalf
+ * of us.
+ *
+ * Note:
+ * Since it is not allowed to run q->delay_work after blk_cleanup_queue()
+ * has canceled q->delay_work, callers must hold the queue lock to avoid
+ * race conditions between blk_cleanup_queue() and blk_run_queue_async().
+ */
+void blk_run_queue_async(struct request_queue *q)
+{
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ if (likely(!blk_queue_stopped(q) && !blk_queue_dead(q)))
+ mod_delayed_work(kblockd_workqueue, &q->delay_work, 0);
+}
+EXPORT_SYMBOL(blk_run_queue_async);
+
+/**
+ * blk_run_queue - run a single device queue
+ * @q: The queue to run
+ *
+ * Description:
+ * Invoke request handling on this queue, if it has pending work to do.
+ * May be used to restart queueing when a request has completed.
+ */
+void blk_run_queue(struct request_queue *q)
+{
+ unsigned long flags;
+
+ WARN_ON_ONCE(q->mq_ops);
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ __blk_run_queue(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL(blk_run_queue);
+
+void blk_put_queue(struct request_queue *q)
+{
+ kobject_put(&q->kobj);
+}
+EXPORT_SYMBOL(blk_put_queue);
+
+/**
+ * __blk_drain_queue - drain requests from request_queue
+ * @q: queue to drain
+ * @drain_all: whether to drain all requests or only the ones w/ ELVPRIV
+ *
+ * Drain requests from @q. If @drain_all is set, all requests are drained.
+ * If not, only ELVPRIV requests are drained. The caller is responsible
+ * for ensuring that no new requests which need to be drained are queued.
+ */
+static void __blk_drain_queue(struct request_queue *q, bool drain_all)
+ __releases(q->queue_lock)
+ __acquires(q->queue_lock)
+{
+ int i;
+
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ while (true) {
+ bool drain = false;
+
+ /*
+ * The caller might be trying to drain @q before its
+ * elevator is initialized.
+ */
+ if (q->elevator)
+ elv_drain_elevator(q);
+
+ blkcg_drain_queue(q);
+
+ /*
+ * This function might be called on a queue which failed
+ * driver init after queue creation or is not yet fully
+ * active yet. Some drivers (e.g. fd and loop) get unhappy
+ * in such cases. Kick queue iff dispatch queue has
+ * something on it and @q has request_fn set.
+ */
+ if (!list_empty(&q->queue_head) && q->request_fn)
+ __blk_run_queue(q);
+
+ drain |= q->nr_rqs_elvpriv;
+ drain |= q->request_fn_active;
+
+ /*
+ * Unfortunately, requests are queued at and tracked from
+ * multiple places and there's no single counter which can
+ * be drained. Check all the queues and counters.
+ */
+ if (drain_all) {
+ struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
+ drain |= !list_empty(&q->queue_head);
+ for (i = 0; i < 2; i++) {
+ drain |= q->nr_rqs[i];
+ drain |= q->in_flight[i];
+ if (fq)
+ drain |= !list_empty(&fq->flush_queue[i]);
+ }
+ }
+
+ if (!drain)
+ break;
+
+ spin_unlock_irq(q->queue_lock);
+
+ msleep(10);
+
+ spin_lock_irq(q->queue_lock);
+ }
+
+ /*
+ * With queue marked dead, any woken up waiter will fail the
+ * allocation path, so the wakeup chaining is lost and we're
+ * left with hung waiters. We need to wake up those waiters.
+ */
+ if (q->request_fn) {
+ struct request_list *rl;
+
+ blk_queue_for_each_rl(rl, q)
+ for (i = 0; i < ARRAY_SIZE(rl->wait); i++)
+ wake_up_all(&rl->wait[i]);
+ }
+}
+
+void blk_drain_queue(struct request_queue *q)
+{
+ spin_lock_irq(q->queue_lock);
+ __blk_drain_queue(q, true);
+ spin_unlock_irq(q->queue_lock);
+}
+
+/**
+ * blk_queue_bypass_start - enter queue bypass mode
+ * @q: queue of interest
+ *
+ * In bypass mode, only the dispatch FIFO queue of @q is used. This
+ * function makes @q enter bypass mode and drains all requests which were
+ * throttled or issued before. On return, it's guaranteed that no request
+ * is being throttled or has ELVPRIV set and blk_queue_bypass() %true
+ * inside queue or RCU read lock.
+ */
+void blk_queue_bypass_start(struct request_queue *q)
+{
+ WARN_ON_ONCE(q->mq_ops);
+
+ spin_lock_irq(q->queue_lock);
+ q->bypass_depth++;
+ queue_flag_set(QUEUE_FLAG_BYPASS, q);
+ spin_unlock_irq(q->queue_lock);
+
+ /*
+ * Queues start drained. Skip actual draining till init is
+ * complete. This avoids lenghty delays during queue init which
+ * can happen many times during boot.
+ */
+ if (blk_queue_init_done(q)) {
+ spin_lock_irq(q->queue_lock);
+ __blk_drain_queue(q, false);
+ spin_unlock_irq(q->queue_lock);
+
+ /* ensure blk_queue_bypass() is %true inside RCU read lock */
+ synchronize_rcu();
+ }
+}
+EXPORT_SYMBOL_GPL(blk_queue_bypass_start);
+
+/**
+ * blk_queue_bypass_end - leave queue bypass mode
+ * @q: queue of interest
+ *
+ * Leave bypass mode and restore the normal queueing behavior.
+ *
+ * Note: although blk_queue_bypass_start() is only called for blk-sq queues,
+ * this function is called for both blk-sq and blk-mq queues.
+ */
+void blk_queue_bypass_end(struct request_queue *q)
+{
+ spin_lock_irq(q->queue_lock);
+ if (!--q->bypass_depth)
+ queue_flag_clear(QUEUE_FLAG_BYPASS, q);
+ WARN_ON_ONCE(q->bypass_depth < 0);
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL_GPL(blk_queue_bypass_end);
+
+void blk_set_queue_dying(struct request_queue *q)
+{
+ spin_lock_irq(q->queue_lock);
+ queue_flag_set(QUEUE_FLAG_DYING, q);
+ spin_unlock_irq(q->queue_lock);
+
+ /*
+ * When queue DYING flag is set, we need to block new req
+ * entering queue, so we call blk_freeze_queue_start() to
+ * prevent I/O from crossing blk_queue_enter().
+ */
+ blk_freeze_queue_start(q);
+
+ if (q->mq_ops)
+ blk_mq_wake_waiters(q);
+ else {
+ struct request_list *rl;
+
+ spin_lock_irq(q->queue_lock);
+ blk_queue_for_each_rl(rl, q) {
+ if (rl->rq_pool) {
+ wake_up_all(&rl->wait[BLK_RW_SYNC]);
+ wake_up_all(&rl->wait[BLK_RW_ASYNC]);
+ }
+ }
+ spin_unlock_irq(q->queue_lock);
+ }
+}
+EXPORT_SYMBOL_GPL(blk_set_queue_dying);
+
+/**
+ * blk_cleanup_queue - shutdown a request queue
+ * @q: request queue to shutdown
+ *
+ * Mark @q DYING, drain all pending requests, mark @q DEAD, destroy and
+ * put it. All future requests will be failed immediately with -ENODEV.
+ */
+void blk_cleanup_queue(struct request_queue *q)
+{
+ spinlock_t *lock = q->queue_lock;
+
+ /* mark @q DYING, no new request or merges will be allowed afterwards */
+ mutex_lock(&q->sysfs_lock);
+ blk_set_queue_dying(q);
+ spin_lock_irq(lock);
+
+ /*
+ * A dying queue is permanently in bypass mode till released. Note
+ * that, unlike blk_queue_bypass_start(), we aren't performing
+ * synchronize_rcu() after entering bypass mode to avoid the delay
+ * as some drivers create and destroy a lot of queues while
+ * probing. This is still safe because blk_release_queue() will be
+ * called only after the queue refcnt drops to zero and nothing,
+ * RCU or not, would be traversing the queue by then.
+ */
+ q->bypass_depth++;
+ queue_flag_set(QUEUE_FLAG_BYPASS, q);
+
+ queue_flag_set(QUEUE_FLAG_NOMERGES, q);
+ queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
+ queue_flag_set(QUEUE_FLAG_DYING, q);
+ spin_unlock_irq(lock);
+ mutex_unlock(&q->sysfs_lock);
+
+ /*
+ * Drain all requests queued before DYING marking. Set DEAD flag to
+ * prevent that q->request_fn() gets invoked after draining finished.
+ */
+ blk_freeze_queue(q);
+ spin_lock_irq(lock);
+ queue_flag_set(QUEUE_FLAG_DEAD, q);
+ spin_unlock_irq(lock);
+
+ /*
+ * make sure all in-progress dispatch are completed because
+ * blk_freeze_queue() can only complete all requests, and
+ * dispatch may still be in-progress since we dispatch requests
+ * from more than one contexts.
+ *
+ * We rely on driver to deal with the race in case that queue
+ * initialization isn't done.
+ */
+ if (q->mq_ops && blk_queue_init_done(q))
+ blk_mq_quiesce_queue(q);
+
+ /* for synchronous bio-based driver finish in-flight integrity i/o */
+ blk_flush_integrity();
+
+ /* @q won't process any more request, flush async actions */
+ del_timer_sync(&q->backing_dev_info->laptop_mode_wb_timer);
+ blk_sync_queue(q);
+
+ if (q->mq_ops)
+ blk_mq_free_queue(q);
+ percpu_ref_exit(&q->q_usage_counter);
+
+ spin_lock_irq(lock);
+ if (q->queue_lock != &q->__queue_lock)
+ q->queue_lock = &q->__queue_lock;
+ spin_unlock_irq(lock);
+
+ /* @q is and will stay empty, shutdown and put */
+ blk_put_queue(q);
+}
+EXPORT_SYMBOL(blk_cleanup_queue);
+
+/* Allocate memory local to the request queue */
+static void *alloc_request_simple(gfp_t gfp_mask, void *data)
+{
+ struct request_queue *q = data;
+
+ return kmem_cache_alloc_node(request_cachep, gfp_mask, q->node);
+}
+
+static void free_request_simple(void *element, void *data)
+{
+ kmem_cache_free(request_cachep, element);
+}
+
+static void *alloc_request_size(gfp_t gfp_mask, void *data)
+{
+ struct request_queue *q = data;
+ struct request *rq;
+
+ rq = kmalloc_node(sizeof(struct request) + q->cmd_size, gfp_mask,
+ q->node);
+ if (rq && q->init_rq_fn && q->init_rq_fn(q, rq, gfp_mask) < 0) {
+ kfree(rq);
+ rq = NULL;
+ }
+ return rq;
+}
+
+static void free_request_size(void *element, void *data)
+{
+ struct request_queue *q = data;
+
+ if (q->exit_rq_fn)
+ q->exit_rq_fn(q, element);
+ kfree(element);
+}
+
+int blk_init_rl(struct request_list *rl, struct request_queue *q,
+ gfp_t gfp_mask)
+{
+ if (unlikely(rl->rq_pool))
+ return 0;
+
+ rl->q = q;
+ rl->count[BLK_RW_SYNC] = rl->count[BLK_RW_ASYNC] = 0;
+ rl->starved[BLK_RW_SYNC] = rl->starved[BLK_RW_ASYNC] = 0;
+ init_waitqueue_head(&rl->wait[BLK_RW_SYNC]);
+ init_waitqueue_head(&rl->wait[BLK_RW_ASYNC]);
+
+ if (q->cmd_size) {
+ rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ,
+ alloc_request_size, free_request_size,
+ q, gfp_mask, q->node);
+ } else {
+ rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ,
+ alloc_request_simple, free_request_simple,
+ q, gfp_mask, q->node);
+ }
+ if (!rl->rq_pool)
+ return -ENOMEM;
+
+ if (rl != &q->root_rl)
+ WARN_ON_ONCE(!blk_get_queue(q));
+
+ return 0;
+}
+
+void blk_exit_rl(struct request_queue *q, struct request_list *rl)
+{
+ if (rl->rq_pool) {
+ mempool_destroy(rl->rq_pool);
+ if (rl != &q->root_rl)
+ blk_put_queue(q);
+ }
+}
+
+struct request_queue *blk_alloc_queue(gfp_t gfp_mask)
+{
+ return blk_alloc_queue_node(gfp_mask, NUMA_NO_NODE);
+}
+EXPORT_SYMBOL(blk_alloc_queue);
+
+int blk_queue_enter(struct request_queue *q, bool nowait)
+{
+ while (true) {
+
+ if (percpu_ref_tryget_live(&q->q_usage_counter))
+ return 0;
+
+ if (nowait)
+ return -EBUSY;
+
+ /*
+ * read pair of barrier in blk_freeze_queue_start(),
+ * we need to order reading __PERCPU_REF_DEAD flag of
+ * .q_usage_counter and reading .mq_freeze_depth or
+ * queue dying flag, otherwise the following wait may
+ * never return if the two reads are reordered.
+ */
+ smp_rmb();
+
+ wait_event(q->mq_freeze_wq,
+ !atomic_read(&q->mq_freeze_depth) ||
+ blk_queue_dying(q));
+ if (blk_queue_dying(q))
+ return -ENODEV;
+ }
+}
+
+void blk_queue_exit(struct request_queue *q)
+{
+ percpu_ref_put(&q->q_usage_counter);
+}
+
+static void blk_queue_usage_counter_release(struct percpu_ref *ref)
+{
+ struct request_queue *q =
+ container_of(ref, struct request_queue, q_usage_counter);
+
+ wake_up_all(&q->mq_freeze_wq);
+}
+
+static void blk_rq_timed_out_timer(unsigned long data)
+{
+ struct request_queue *q = (struct request_queue *)data;
+
+ kblockd_schedule_work(&q->timeout_work);
+}
+
+struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
+{
+ struct request_queue *q;
+
+ q = kmem_cache_alloc_node(blk_requestq_cachep,
+ gfp_mask | __GFP_ZERO, node_id);
+ if (!q)
+ return NULL;
+
+ q->id = ida_simple_get(&blk_queue_ida, 0, 0, gfp_mask);
+ if (q->id < 0)
+ goto fail_q;
+
+ q->bio_split = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
+ if (!q->bio_split)
+ goto fail_id;
+
+ q->backing_dev_info = bdi_alloc_node(gfp_mask, node_id);
+ if (!q->backing_dev_info)
+ goto fail_split;
+
+ q->stats = blk_alloc_queue_stats();
+ if (!q->stats)
+ goto fail_stats;
+
+ q->backing_dev_info->ra_pages =
+ (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
+ q->backing_dev_info->io_pages =
+ (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
+ q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK;
+ q->backing_dev_info->name = "block";
+ q->node = node_id;
+
+ setup_timer(&q->backing_dev_info->laptop_mode_wb_timer,
+ laptop_mode_timer_fn, (unsigned long) q);
+ setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
+ INIT_WORK(&q->timeout_work, NULL);
+ INIT_LIST_HEAD(&q->queue_head);
+ INIT_LIST_HEAD(&q->timeout_list);
+ INIT_LIST_HEAD(&q->icq_list);
+#ifdef CONFIG_BLK_CGROUP
+ INIT_LIST_HEAD(&q->blkg_list);
+#endif
+ INIT_DELAYED_WORK(&q->delay_work, blk_delay_work);
+
+ kobject_init(&q->kobj, &blk_queue_ktype);
+
+#ifdef CONFIG_BLK_DEV_IO_TRACE
+ mutex_init(&q->blk_trace_mutex);
+#endif
+ mutex_init(&q->sysfs_lock);
+ spin_lock_init(&q->__queue_lock);
+
+ /*
+ * By default initialize queue_lock to internal lock and driver can
+ * override it later if need be.
+ */
+ q->queue_lock = &q->__queue_lock;
+
+ /*
+ * A queue starts its life with bypass turned on to avoid
+ * unnecessary bypass on/off overhead and nasty surprises during
+ * init. The initial bypass will be finished when the queue is
+ * registered by blk_register_queue().
+ */
+ q->bypass_depth = 1;
+ __set_bit(QUEUE_FLAG_BYPASS, &q->queue_flags);
+
+ init_waitqueue_head(&q->mq_freeze_wq);
+
+ /*
+ * Init percpu_ref in atomic mode so that it's faster to shutdown.
+ * See blk_register_queue() for details.
+ */
+ if (percpu_ref_init(&q->q_usage_counter,
+ blk_queue_usage_counter_release,
+ PERCPU_REF_INIT_ATOMIC, GFP_KERNEL))
+ goto fail_bdi;
+
+ if (blkcg_init_queue(q))
+ goto fail_ref;
+
+ return q;
+
+fail_ref:
+ percpu_ref_exit(&q->q_usage_counter);
+fail_bdi:
+ blk_free_queue_stats(q->stats);
+fail_stats:
+ bdi_put(q->backing_dev_info);
+fail_split:
+ bioset_free(q->bio_split);
+fail_id:
+ ida_simple_remove(&blk_queue_ida, q->id);
+fail_q:
+ kmem_cache_free(blk_requestq_cachep, q);
+ return NULL;
+}
+EXPORT_SYMBOL(blk_alloc_queue_node);
+
+/**
+ * blk_init_queue - prepare a request queue for use with a block device
+ * @rfn: The function to be called to process requests that have been
+ * placed on the queue.
+ * @lock: Request queue spin lock
+ *
+ * Description:
+ * If a block device wishes to use the standard request handling procedures,
+ * which sorts requests and coalesces adjacent requests, then it must
+ * call blk_init_queue(). The function @rfn will be called when there
+ * are requests on the queue that need to be processed. If the device
+ * supports plugging, then @rfn may not be called immediately when requests
+ * are available on the queue, but may be called at some time later instead.
+ * Plugged queues are generally unplugged when a buffer belonging to one
+ * of the requests on the queue is needed, or due to memory pressure.
+ *
+ * @rfn is not required, or even expected, to remove all requests off the
+ * queue, but only as many as it can handle at a time. If it does leave
+ * requests on the queue, it is responsible for arranging that the requests
+ * get dealt with eventually.
+ *
+ * The queue spin lock must be held while manipulating the requests on the
+ * request queue; this lock will be taken also from interrupt context, so irq
+ * disabling is needed for it.
+ *
+ * Function returns a pointer to the initialized request queue, or %NULL if
+ * it didn't succeed.
+ *
+ * Note:
+ * blk_init_queue() must be paired with a blk_cleanup_queue() call
+ * when the block device is deactivated (such as at module unload).
+ **/
+
+struct request_queue *blk_init_queue(request_fn_proc *rfn, spinlock_t *lock)
+{
+ return blk_init_queue_node(rfn, lock, NUMA_NO_NODE);
+}
+EXPORT_SYMBOL(blk_init_queue);
+
+struct request_queue *
+blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
+{
+ struct request_queue *q;
+
+ q = blk_alloc_queue_node(GFP_KERNEL, node_id);
+ if (!q)
+ return NULL;
+
+ q->request_fn = rfn;
+ if (lock)
+ q->queue_lock = lock;
+ if (blk_init_allocated_queue(q) < 0) {
+ blk_cleanup_queue(q);
+ return NULL;
+ }
+
+ return q;
+}
+EXPORT_SYMBOL(blk_init_queue_node);
+
+static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio);
+
+
+int blk_init_allocated_queue(struct request_queue *q)
+{
+ WARN_ON_ONCE(q->mq_ops);
+
+ q->fq = blk_alloc_flush_queue(q, NUMA_NO_NODE, q->cmd_size);
+ if (!q->fq)
+ return -ENOMEM;
+
+ if (q->init_rq_fn && q->init_rq_fn(q, q->fq->flush_rq, GFP_KERNEL))
+ goto out_free_flush_queue;
+
+ if (blk_init_rl(&q->root_rl, q, GFP_KERNEL))
+ goto out_exit_flush_rq;
+
+ INIT_WORK(&q->timeout_work, blk_timeout_work);
+ q->queue_flags |= QUEUE_FLAG_DEFAULT;
+
+ /*
+ * This also sets hw/phys segments, boundary and size
+ */
+ blk_queue_make_request(q, blk_queue_bio);
+
+ q->sg_reserved_size = INT_MAX;
+
+ /* Protect q->elevator from elevator_change */
+ mutex_lock(&q->sysfs_lock);
+
+ /* init elevator */
+ if (elevator_init(q, NULL)) {
+ mutex_unlock(&q->sysfs_lock);
+ goto out_exit_flush_rq;
+ }
+
+ mutex_unlock(&q->sysfs_lock);
+ return 0;
+
+out_exit_flush_rq:
+ if (q->exit_rq_fn)
+ q->exit_rq_fn(q, q->fq->flush_rq);
+out_free_flush_queue:
+ blk_free_flush_queue(q->fq);
+ q->fq = NULL;
+ return -ENOMEM;
+}
+EXPORT_SYMBOL(blk_init_allocated_queue);
+
+bool blk_get_queue(struct request_queue *q)
+{
+ if (likely(!blk_queue_dying(q))) {
+ __blk_get_queue(q);
+ return true;
+ }
+
+ return false;
+}
+EXPORT_SYMBOL(blk_get_queue);
+
+static inline void blk_free_request(struct request_list *rl, struct request *rq)
+{
+ if (rq->rq_flags & RQF_ELVPRIV) {
+ elv_put_request(rl->q, rq);
+ if (rq->elv.icq)
+ put_io_context(rq->elv.icq->ioc);
+ }
+
+ mempool_free(rq, rl->rq_pool);
+}
+
+/*
+ * ioc_batching returns true if the ioc is a valid batching request and
+ * should be given priority access to a request.
+ */
+static inline int ioc_batching(struct request_queue *q, struct io_context *ioc)
+{
+ if (!ioc)
+ return 0;
+
+ /*
+ * Make sure the process is able to allocate at least 1 request
+ * even if the batch times out, otherwise we could theoretically
+ * lose wakeups.
+ */
+ return ioc->nr_batch_requests == q->nr_batching ||
+ (ioc->nr_batch_requests > 0
+ && time_before(jiffies, ioc->last_waited + BLK_BATCH_TIME));
+}
+
+/*
+ * ioc_set_batching sets ioc to be a new "batcher" if it is not one. This
+ * will cause the process to be a "batcher" on all queues in the system. This
+ * is the behaviour we want though - once it gets a wakeup it should be given
+ * a nice run.
+ */
+static void ioc_set_batching(struct request_queue *q, struct io_context *ioc)
+{
+ if (!ioc || ioc_batching(q, ioc))
+ return;
+
+ ioc->nr_batch_requests = q->nr_batching;
+ ioc->last_waited = jiffies;
+}
+
+static void __freed_request(struct request_list *rl, int sync)
+{
+ struct request_queue *q = rl->q;
+
+ if (rl->count[sync] < queue_congestion_off_threshold(q))
+ blk_clear_congested(rl, sync);
+
+ if (rl->count[sync] + 1 <= q->nr_requests) {
+ if (waitqueue_active(&rl->wait[sync]))
+ wake_up(&rl->wait[sync]);
+
+ blk_clear_rl_full(rl, sync);
+ }
+}
+
+/*
+ * A request has just been released. Account for it, update the full and
+ * congestion status, wake up any waiters. Called under q->queue_lock.
+ */
+static void freed_request(struct request_list *rl, bool sync,
+ req_flags_t rq_flags)
+{
+ struct request_queue *q = rl->q;
+
+ q->nr_rqs[sync]--;
+ rl->count[sync]--;
+ if (rq_flags & RQF_ELVPRIV)
+ q->nr_rqs_elvpriv--;
+
+ __freed_request(rl, sync);
+
+ if (unlikely(rl->starved[sync ^ 1]))
+ __freed_request(rl, sync ^ 1);
+}
+
+int blk_update_nr_requests(struct request_queue *q, unsigned int nr)
+{
+ struct request_list *rl;
+ int on_thresh, off_thresh;
+
+ WARN_ON_ONCE(q->mq_ops);
+
+ spin_lock_irq(q->queue_lock);
+ q->nr_requests = nr;
+ blk_queue_congestion_threshold(q);
+ on_thresh = queue_congestion_on_threshold(q);
+ off_thresh = queue_congestion_off_threshold(q);
+
+ blk_queue_for_each_rl(rl, q) {
+ if (rl->count[BLK_RW_SYNC] >= on_thresh)
+ blk_set_congested(rl, BLK_RW_SYNC);
+ else if (rl->count[BLK_RW_SYNC] < off_thresh)
+ blk_clear_congested(rl, BLK_RW_SYNC);
+
+ if (rl->count[BLK_RW_ASYNC] >= on_thresh)
+ blk_set_congested(rl, BLK_RW_ASYNC);
+ else if (rl->count[BLK_RW_ASYNC] < off_thresh)
+ blk_clear_congested(rl, BLK_RW_ASYNC);
+
+ if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
+ blk_set_rl_full(rl, BLK_RW_SYNC);
+ } else {
+ blk_clear_rl_full(rl, BLK_RW_SYNC);
+ wake_up(&rl->wait[BLK_RW_SYNC]);
+ }
+
+ if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
+ blk_set_rl_full(rl, BLK_RW_ASYNC);
+ } else {
+ blk_clear_rl_full(rl, BLK_RW_ASYNC);
+ wake_up(&rl->wait[BLK_RW_ASYNC]);
+ }
+ }
+
+ spin_unlock_irq(q->queue_lock);
+ return 0;
+}
+
+/**
+ * __get_request - get a free request
+ * @rl: request list to allocate from
+ * @op: operation and flags
+ * @bio: bio to allocate request for (can be %NULL)
+ * @gfp_mask: allocation mask
+ *
+ * Get a free request from @q. This function may fail under memory
+ * pressure or if @q is dead.
+ *
+ * Must be called with @q->queue_lock held and,
+ * Returns ERR_PTR on failure, with @q->queue_lock held.
+ * Returns request pointer on success, with @q->queue_lock *not held*.
+ */
+static struct request *__get_request(struct request_list *rl, unsigned int op,
+ struct bio *bio, gfp_t gfp_mask)
+{
+ struct request_queue *q = rl->q;
+ struct request *rq;
+ struct elevator_type *et = q->elevator->type;
+ struct io_context *ioc = rq_ioc(bio);
+ struct io_cq *icq = NULL;
+ const bool is_sync = op_is_sync(op);
+ int may_queue;
+ req_flags_t rq_flags = RQF_ALLOCED;
+
+ lockdep_assert_held(q->queue_lock);
+
+ if (unlikely(blk_queue_dying(q)))
+ return ERR_PTR(-ENODEV);
+
+ may_queue = elv_may_queue(q, op);
+ if (may_queue == ELV_MQUEUE_NO)
+ goto rq_starved;
+
+ if (rl->count[is_sync]+1 >= queue_congestion_on_threshold(q)) {
+ if (rl->count[is_sync]+1 >= q->nr_requests) {
+ /*
+ * The queue will fill after this allocation, so set
+ * it as full, and mark this process as "batching".
+ * This process will be allowed to complete a batch of
+ * requests, others will be blocked.
+ */
+ if (!blk_rl_full(rl, is_sync)) {
+ ioc_set_batching(q, ioc);
+ blk_set_rl_full(rl, is_sync);
+ } else {
+ if (may_queue != ELV_MQUEUE_MUST
+ && !ioc_batching(q, ioc)) {
+ /*
+ * The queue is full and the allocating
+ * process is not a "batcher", and not
+ * exempted by the IO scheduler
+ */
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+ }
+ blk_set_congested(rl, is_sync);
+ }
+
+ /*
+ * Only allow batching queuers to allocate up to 50% over the defined
+ * limit of requests, otherwise we could have thousands of requests
+ * allocated with any setting of ->nr_requests
+ */
+ if (rl->count[is_sync] >= (3 * q->nr_requests / 2))
+ return ERR_PTR(-ENOMEM);
+
+ q->nr_rqs[is_sync]++;
+ rl->count[is_sync]++;
+ rl->starved[is_sync] = 0;
+
+ /*
+ * Decide whether the new request will be managed by elevator. If
+ * so, mark @rq_flags and increment elvpriv. Non-zero elvpriv will
+ * prevent the current elevator from being destroyed until the new
+ * request is freed. This guarantees icq's won't be destroyed and
+ * makes creating new ones safe.
+ *
+ * Flush requests do not use the elevator so skip initialization.
+ * This allows a request to share the flush and elevator data.
+ *
+ * Also, lookup icq while holding queue_lock. If it doesn't exist,
+ * it will be created after releasing queue_lock.
+ */
+ if (!op_is_flush(op) && !blk_queue_bypass(q)) {
+ rq_flags |= RQF_ELVPRIV;
+ q->nr_rqs_elvpriv++;
+ if (et->icq_cache && ioc)
+ icq = ioc_lookup_icq(ioc, q);
+ }
+
+ if (blk_queue_io_stat(q))
+ rq_flags |= RQF_IO_STAT;
+ spin_unlock_irq(q->queue_lock);
+
+ /* allocate and init request */
+ rq = mempool_alloc(rl->rq_pool, gfp_mask);
+ if (!rq)
+ goto fail_alloc;
+
+ blk_rq_init(q, rq);
+ blk_rq_set_rl(rq, rl);
+ rq->cmd_flags = op;
+ rq->rq_flags = rq_flags;
+
+ /* init elvpriv */
+ if (rq_flags & RQF_ELVPRIV) {
+ if (unlikely(et->icq_cache && !icq)) {
+ if (ioc)
+ icq = ioc_create_icq(ioc, q, gfp_mask);
+ if (!icq)
+ goto fail_elvpriv;
+ }
+
+ rq->elv.icq = icq;
+ if (unlikely(elv_set_request(q, rq, bio, gfp_mask)))
+ goto fail_elvpriv;
+
+ /* @rq->elv.icq holds io_context until @rq is freed */
+ if (icq)
+ get_io_context(icq->ioc);
+ }
+out:
+ /*
+ * ioc may be NULL here, and ioc_batching will be false. That's
+ * OK, if the queue is under the request limit then requests need
+ * not count toward the nr_batch_requests limit. There will always
+ * be some limit enforced by BLK_BATCH_TIME.
+ */
+ if (ioc_batching(q, ioc))
+ ioc->nr_batch_requests--;
+
+ trace_block_getrq(q, bio, op);
+ return rq;
+
+fail_elvpriv:
+ /*
+ * elvpriv init failed. ioc, icq and elvpriv aren't mempool backed
+ * and may fail indefinitely under memory pressure and thus
+ * shouldn't stall IO. Treat this request as !elvpriv. This will
+ * disturb iosched and blkcg but weird is bettern than dead.
+ */
+ printk_ratelimited(KERN_WARNING "%s: dev %s: request aux data allocation failed, iosched may be disturbed\n",
+ __func__, dev_name(q->backing_dev_info->dev));
+
+ rq->rq_flags &= ~RQF_ELVPRIV;
+ rq->elv.icq = NULL;
+
+ spin_lock_irq(q->queue_lock);
+ q->nr_rqs_elvpriv--;
+ spin_unlock_irq(q->queue_lock);
+ goto out;
+
+fail_alloc:
+ /*
+ * Allocation failed presumably due to memory. Undo anything we
+ * might have messed up.
+ *
+ * Allocating task should really be put onto the front of the wait
+ * queue, but this is pretty rare.
+ */
+ spin_lock_irq(q->queue_lock);
+ freed_request(rl, is_sync, rq_flags);
+
+ /*
+ * in the very unlikely event that allocation failed and no
+ * requests for this direction was pending, mark us starved so that
+ * freeing of a request in the other direction will notice
+ * us. another possible fix would be to split the rq mempool into
+ * READ and WRITE
+ */
+rq_starved:
+ if (unlikely(rl->count[is_sync] == 0))
+ rl->starved[is_sync] = 1;
+ return ERR_PTR(-ENOMEM);
+}
+
+/**
+ * get_request - get a free request
+ * @q: request_queue to allocate request from
+ * @op: operation and flags
+ * @bio: bio to allocate request for (can be %NULL)
+ * @gfp_mask: allocation mask
+ *
+ * Get a free request from @q. If %__GFP_DIRECT_RECLAIM is set in @gfp_mask,
+ * this function keeps retrying under memory pressure and fails iff @q is dead.
+ *
+ * Must be called with @q->queue_lock held and,
+ * Returns ERR_PTR on failure, with @q->queue_lock held.
+ * Returns request pointer on success, with @q->queue_lock *not held*.
+ */
+static struct request *get_request(struct request_queue *q, unsigned int op,
+ struct bio *bio, gfp_t gfp_mask)
+{
+ const bool is_sync = op_is_sync(op);
+ DEFINE_WAIT(wait);
+ struct request_list *rl;
+ struct request *rq;
+
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ rl = blk_get_rl(q, bio); /* transferred to @rq on success */
+retry:
+ rq = __get_request(rl, op, bio, gfp_mask);
+ if (!IS_ERR(rq))
+ return rq;
+
+ if (op & REQ_NOWAIT) {
+ blk_put_rl(rl);
+ return ERR_PTR(-EAGAIN);
+ }
+
+ if (!gfpflags_allow_blocking(gfp_mask) || unlikely(blk_queue_dying(q))) {
+ blk_put_rl(rl);
+ return rq;
+ }
+
+ /* wait on @rl and retry */
+ prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
+ TASK_UNINTERRUPTIBLE);
+
+ trace_block_sleeprq(q, bio, op);
+
+ spin_unlock_irq(q->queue_lock);
+ io_schedule();
+
+ /*
+ * After sleeping, we become a "batching" process and will be able
+ * to allocate at least one request, and up to a big batch of them
+ * for a small period time. See ioc_batching, ioc_set_batching
+ */
+ ioc_set_batching(q, current->io_context);
+
+ spin_lock_irq(q->queue_lock);
+ finish_wait(&rl->wait[is_sync], &wait);
+
+ goto retry;
+}
+
+static struct request *blk_old_get_request(struct request_queue *q,
+ unsigned int op, gfp_t gfp_mask)
+{
+ struct request *rq;
+
+ WARN_ON_ONCE(q->mq_ops);
+
+ /* create ioc upfront */
+ create_io_context(gfp_mask, q->node);
+
+ spin_lock_irq(q->queue_lock);
+ rq = get_request(q, op, NULL, gfp_mask);
+ if (IS_ERR(rq)) {
+ spin_unlock_irq(q->queue_lock);
+ return rq;
+ }
+
+ /* q->queue_lock is unlocked at this point */
+ rq->__data_len = 0;
+ rq->__sector = (sector_t) -1;
+ rq->bio = rq->biotail = NULL;
+ return rq;
+}
+
+struct request *blk_get_request(struct request_queue *q, unsigned int op,
+ gfp_t gfp_mask)
+{
+ struct request *req;
+
+ if (q->mq_ops) {
+ req = blk_mq_alloc_request(q, op,
+ (gfp_mask & __GFP_DIRECT_RECLAIM) ?
+ 0 : BLK_MQ_REQ_NOWAIT);
+ if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn)
+ q->mq_ops->initialize_rq_fn(req);
+ } else {
+ req = blk_old_get_request(q, op, gfp_mask);
+ if (!IS_ERR(req) && q->initialize_rq_fn)
+ q->initialize_rq_fn(req);
+ }
+
+ return req;
+}
+EXPORT_SYMBOL(blk_get_request);
+
+/**
+ * blk_requeue_request - put a request back on queue
+ * @q: request queue where request should be inserted
+ * @rq: request to be inserted
+ *
+ * Description:
+ * Drivers often keep queueing requests until the hardware cannot accept
+ * more, when that condition happens we need to put the request back
+ * on the queue. Must be called with queue lock held.
+ */
+void blk_requeue_request(struct request_queue *q, struct request *rq)
+{
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ blk_delete_timer(rq);
+ blk_clear_rq_complete(rq);
+ trace_block_rq_requeue(q, rq);
+ wbt_requeue(q->rq_wb, &rq->issue_stat);
+
+ if (rq->rq_flags & RQF_QUEUED)
+ blk_queue_end_tag(q, rq);
+
+ BUG_ON(blk_queued_rq(rq));
+
+ elv_requeue_request(q, rq);
+}
+EXPORT_SYMBOL(blk_requeue_request);
+
+static void add_acct_request(struct request_queue *q, struct request *rq,
+ int where)
+{
+ blk_account_io_start(rq, true);
+ __elv_add_request(q, rq, where);
+}
+
+static void part_round_stats_single(struct request_queue *q, int cpu,
+ struct hd_struct *part, unsigned long now,
+ unsigned int inflight)
+{
+ if (inflight) {
+ __part_stat_add(cpu, part, time_in_queue,
+ inflight * (now - part->stamp));
+ __part_stat_add(cpu, part, io_ticks, (now - part->stamp));
+ }
+ part->stamp = now;
+}
+
+/**
+ * part_round_stats() - Round off the performance stats on a struct disk_stats.
+ * @q: target block queue
+ * @cpu: cpu number for stats access
+ * @part: target partition
+ *
+ * The average IO queue length and utilisation statistics are maintained
+ * by observing the current state of the queue length and the amount of
+ * time it has been in this state for.
+ *
+ * Normally, that accounting is done on IO completion, but that can result
+ * in more than a second's worth of IO being accounted for within any one
+ * second, leading to >100% utilisation. To deal with that, we call this
+ * function to do a round-off before returning the results when reading
+ * /proc/diskstats. This accounts immediately for all queue usage up to
+ * the current jiffies and restarts the counters again.
+ */
+void part_round_stats(struct request_queue *q, int cpu, struct hd_struct *part)
+{
+ struct hd_struct *part2 = NULL;
+ unsigned long now = jiffies;
+ unsigned int inflight[2];
+ int stats = 0;
+
+ if (part->stamp != now)
+ stats |= 1;
+
+ if (part->partno) {
+ part2 = &part_to_disk(part)->part0;
+ if (part2->stamp != now)
+ stats |= 2;
+ }
+
+ if (!stats)
+ return;
+
+ part_in_flight(q, part, inflight);
+
+ if (stats & 2)
+ part_round_stats_single(q, cpu, part2, now, inflight[1]);
+ if (stats & 1)
+ part_round_stats_single(q, cpu, part, now, inflight[0]);
+}
+EXPORT_SYMBOL_GPL(part_round_stats);
+
+#ifdef CONFIG_PM
+static void blk_pm_put_request(struct request *rq)
+{
+ if (rq->q->dev && !(rq->rq_flags & RQF_PM) && !--rq->q->nr_pending)
+ pm_runtime_mark_last_busy(rq->q->dev);
+}
+#else
+static inline void blk_pm_put_request(struct request *rq) {}
+#endif
+
+void __blk_put_request(struct request_queue *q, struct request *req)
+{
+ req_flags_t rq_flags = req->rq_flags;
+
+ if (unlikely(!q))
+ return;
+
+ if (q->mq_ops) {
+ blk_mq_free_request(req);
+ return;
+ }
+
+ lockdep_assert_held(q->queue_lock);
+
+ blk_pm_put_request(req);
+
+ elv_completed_request(q, req);
+
+ /* this is a bio leak */
+ WARN_ON(req->bio != NULL);
+
+ wbt_done(q->rq_wb, &req->issue_stat);
+
+ /*
+ * Request may not have originated from ll_rw_blk. if not,
+ * it didn't come out of our reserved rq pools
+ */
+ if (rq_flags & RQF_ALLOCED) {
+ struct request_list *rl = blk_rq_rl(req);
+ bool sync = op_is_sync(req->cmd_flags);
+
+ BUG_ON(!list_empty(&req->queuelist));
+ BUG_ON(ELV_ON_HASH(req));
+
+ blk_free_request(rl, req);
+ freed_request(rl, sync, rq_flags);
+ blk_put_rl(rl);
+ }
+}
+EXPORT_SYMBOL_GPL(__blk_put_request);
+
+void blk_put_request(struct request *req)
+{
+ struct request_queue *q = req->q;
+
+ if (q->mq_ops)
+ blk_mq_free_request(req);
+ else {
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ __blk_put_request(q, req);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ }
+}
+EXPORT_SYMBOL(blk_put_request);
+
+bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
+ struct bio *bio)
+{
+ const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
+
+ if (!ll_back_merge_fn(q, req, bio))
+ return false;
+
+ trace_block_bio_backmerge(q, req, bio);
+
+ if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
+ blk_rq_set_mixed_merge(req);
+
+ req->biotail->bi_next = bio;
+ req->biotail = bio;
+ req->__data_len += bio->bi_iter.bi_size;
+ req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
+
+ blk_account_io_start(req, false);
+ return true;
+}
+
+bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
+ struct bio *bio)
+{
+ const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
+
+ if (!ll_front_merge_fn(q, req, bio))
+ return false;
+
+ trace_block_bio_frontmerge(q, req, bio);
+
+ if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
+ blk_rq_set_mixed_merge(req);
+
+ bio->bi_next = req->bio;
+ req->bio = bio;
+
+ req->__sector = bio->bi_iter.bi_sector;
+ req->__data_len += bio->bi_iter.bi_size;
+ req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
+
+ blk_account_io_start(req, false);
+ return true;
+}
+
+bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
+ struct bio *bio)
+{
+ unsigned short segments = blk_rq_nr_discard_segments(req);
+
+ if (segments >= queue_max_discard_segments(q))
+ goto no_merge;
+ if (blk_rq_sectors(req) + bio_sectors(bio) >
+ blk_rq_get_max_sectors(req, blk_rq_pos(req)))
+ goto no_merge;
+
+ req->biotail->bi_next = bio;
+ req->biotail = bio;
+ req->__data_len += bio->bi_iter.bi_size;
+ req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
+ req->nr_phys_segments = segments + 1;
+
+ blk_account_io_start(req, false);
+ return true;
+no_merge:
+ req_set_nomerge(q, req);
+ return false;
+}
+
+/**
+ * blk_attempt_plug_merge - try to merge with %current's plugged list
+ * @q: request_queue new bio is being queued at
+ * @bio: new bio being queued
+ * @request_count: out parameter for number of traversed plugged requests
+ * @same_queue_rq: pointer to &struct request that gets filled in when
+ * another request associated with @q is found on the plug list
+ * (optional, may be %NULL)
+ *
+ * Determine whether @bio being queued on @q can be merged with a request
+ * on %current's plugged list. Returns %true if merge was successful,
+ * otherwise %false.
+ *
+ * Plugging coalesces IOs from the same issuer for the same purpose without
+ * going through @q->queue_lock. As such it's more of an issuing mechanism
+ * than scheduling, and the request, while may have elvpriv data, is not
+ * added on the elevator at this point. In addition, we don't have
+ * reliable access to the elevator outside queue lock. Only check basic
+ * merging parameters without querying the elevator.
+ *
+ * Caller must ensure !blk_queue_nomerges(q) beforehand.
+ */
+bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
+ unsigned int *request_count,
+ struct request **same_queue_rq)
+{
+ struct blk_plug *plug;
+ struct request *rq;
+ struct list_head *plug_list;
+
+ plug = current->plug;
+ if (!plug)
+ return false;
+ *request_count = 0;
+
+ if (q->mq_ops)
+ plug_list = &plug->mq_list;
+ else
+ plug_list = &plug->list;
+
+ list_for_each_entry_reverse(rq, plug_list, queuelist) {
+ bool merged = false;
+
+ if (rq->q == q) {
+ (*request_count)++;
+ /*
+ * Only blk-mq multiple hardware queues case checks the
+ * rq in the same queue, there should be only one such
+ * rq in a queue
+ **/
+ if (same_queue_rq)
+ *same_queue_rq = rq;
+ }
+
+ if (rq->q != q || !blk_rq_merge_ok(rq, bio))
+ continue;
+
+ switch (blk_try_merge(rq, bio)) {
+ case ELEVATOR_BACK_MERGE:
+ merged = bio_attempt_back_merge(q, rq, bio);
+ break;
+ case ELEVATOR_FRONT_MERGE:
+ merged = bio_attempt_front_merge(q, rq, bio);
+ break;
+ case ELEVATOR_DISCARD_MERGE:
+ merged = bio_attempt_discard_merge(q, rq, bio);
+ break;
+ default:
+ break;
+ }
+
+ if (merged)
+ return true;
+ }
+
+ return false;
+}
+
+unsigned int blk_plug_queued_count(struct request_queue *q)
+{
+ struct blk_plug *plug;
+ struct request *rq;
+ struct list_head *plug_list;
+ unsigned int ret = 0;
+
+ plug = current->plug;
+ if (!plug)
+ goto out;
+
+ if (q->mq_ops)
+ plug_list = &plug->mq_list;
+ else
+ plug_list = &plug->list;
+
+ list_for_each_entry(rq, plug_list, queuelist) {
+ if (rq->q == q)
+ ret++;
+ }
+out:
+ return ret;
+}
+
+void blk_init_request_from_bio(struct request *req, struct bio *bio)
+{
+ struct io_context *ioc = rq_ioc(bio);
+
+ if (bio->bi_opf & REQ_RAHEAD)
+ req->cmd_flags |= REQ_FAILFAST_MASK;
+
+ req->__sector = bio->bi_iter.bi_sector;
+ if (ioprio_valid(bio_prio(bio)))
+ req->ioprio = bio_prio(bio);
+ else if (ioc)
+ req->ioprio = ioc->ioprio;
+ else
+ req->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0);
+ req->write_hint = bio->bi_write_hint;
+ blk_rq_bio_prep(req->q, req, bio);
+}
+EXPORT_SYMBOL_GPL(blk_init_request_from_bio);
+
+static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
+{
+ struct blk_plug *plug;
+ int where = ELEVATOR_INSERT_SORT;
+ struct request *req, *free;
+ unsigned int request_count = 0;
+ unsigned int wb_acct;
+
+ /*
+ * low level driver can indicate that it wants pages above a
+ * certain limit bounced to low memory (ie for highmem, or even
+ * ISA dma in theory)
+ */
+ blk_queue_bounce(q, &bio);
+
+ blk_queue_split(q, &bio);
+
+ if (!bio_integrity_prep(bio))
+ return BLK_QC_T_NONE;
+
+ if (op_is_flush(bio->bi_opf)) {
+ spin_lock_irq(q->queue_lock);
+ where = ELEVATOR_INSERT_FLUSH;
+ goto get_rq;
+ }
+
+ /*
+ * Check if we can merge with the plugged list before grabbing
+ * any locks.
+ */
+ if (!blk_queue_nomerges(q)) {
+ if (blk_attempt_plug_merge(q, bio, &request_count, NULL))
+ return BLK_QC_T_NONE;
+ } else
+ request_count = blk_plug_queued_count(q);
+
+ spin_lock_irq(q->queue_lock);
+
+ switch (elv_merge(q, &req, bio)) {
+ case ELEVATOR_BACK_MERGE:
+ if (!bio_attempt_back_merge(q, req, bio))
+ break;
+ elv_bio_merged(q, req, bio);
+ free = attempt_back_merge(q, req);
+ if (free)
+ __blk_put_request(q, free);
+ else
+ elv_merged_request(q, req, ELEVATOR_BACK_MERGE);
+ goto out_unlock;
+ case ELEVATOR_FRONT_MERGE:
+ if (!bio_attempt_front_merge(q, req, bio))
+ break;
+ elv_bio_merged(q, req, bio);
+ free = attempt_front_merge(q, req);
+ if (free)
+ __blk_put_request(q, free);
+ else
+ elv_merged_request(q, req, ELEVATOR_FRONT_MERGE);
+ goto out_unlock;
+ default:
+ break;
+ }
+
+get_rq:
+ wb_acct = wbt_wait(q->rq_wb, bio, q->queue_lock);
+
+ /*
+ * Grab a free request. This is might sleep but can not fail.
+ * Returns with the queue unlocked.
+ */
+ req = get_request(q, bio->bi_opf, bio, GFP_NOIO);
+ if (IS_ERR(req)) {
+ __wbt_done(q->rq_wb, wb_acct);
+ if (PTR_ERR(req) == -ENOMEM)
+ bio->bi_status = BLK_STS_RESOURCE;
+ else
+ bio->bi_status = BLK_STS_IOERR;
+ bio_endio(bio);
+ goto out_unlock;
+ }
+
+ wbt_track(&req->issue_stat, wb_acct);
+
+ /*
+ * After dropping the lock and possibly sleeping here, our request
+ * may now be mergeable after it had proven unmergeable (above).
+ * We don't worry about that case for efficiency. It won't happen
+ * often, and the elevators are able to handle it.
+ */
+ blk_init_request_from_bio(req, bio);
+
+ if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags))
+ req->cpu = raw_smp_processor_id();
+
+ plug = current->plug;
+ if (plug) {
+ /*
+ * If this is the first request added after a plug, fire
+ * of a plug trace.
+ *
+ * @request_count may become stale because of schedule
+ * out, so check plug list again.
+ */
+ if (!request_count || list_empty(&plug->list))
+ trace_block_plug(q);
+ else {
+ struct request *last = list_entry_rq(plug->list.prev);
+ if (request_count >= BLK_MAX_REQUEST_COUNT ||
+ blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE) {
+ blk_flush_plug_list(plug, false);
+ trace_block_plug(q);
+ }
+ }
+ list_add_tail(&req->queuelist, &plug->list);
+ blk_account_io_start(req, true);
+ } else {
+ spin_lock_irq(q->queue_lock);
+ add_acct_request(q, req, where);
+ __blk_run_queue(q);
+out_unlock:
+ spin_unlock_irq(q->queue_lock);
+ }
+
+ return BLK_QC_T_NONE;
+}
+
+static void handle_bad_sector(struct bio *bio)
+{
+ char b[BDEVNAME_SIZE];
+
+ printk(KERN_INFO "attempt to access beyond end of device\n");
+ printk(KERN_INFO "%s: rw=%d, want=%Lu, limit=%Lu\n",
+ bio_devname(bio, b), bio->bi_opf,
+ (unsigned long long)bio_end_sector(bio),
+ (long long)get_capacity(bio->bi_disk));
+}
+
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+
+static DECLARE_FAULT_ATTR(fail_make_request);
+
+static int __init setup_fail_make_request(char *str)
+{
+ return setup_fault_attr(&fail_make_request, str);
+}
+__setup("fail_make_request=", setup_fail_make_request);
+
+static bool should_fail_request(struct hd_struct *part, unsigned int bytes)
+{
+ return part->make_it_fail && should_fail(&fail_make_request, bytes);
+}
+
+static int __init fail_make_request_debugfs(void)
+{
+ struct dentry *dir = fault_create_debugfs_attr("fail_make_request",
+ NULL, &fail_make_request);
+
+ return PTR_ERR_OR_ZERO(dir);
+}
+
+late_initcall(fail_make_request_debugfs);
+
+#else /* CONFIG_FAIL_MAKE_REQUEST */
+
+static inline bool should_fail_request(struct hd_struct *part,
+ unsigned int bytes)
+{
+ return false;
+}
+
+#endif /* CONFIG_FAIL_MAKE_REQUEST */
+
+/*
+ * Remap block n of partition p to block n+start(p) of the disk.
+ */
+static inline int blk_partition_remap(struct bio *bio)
+{
+ struct hd_struct *p;
+ int ret = 0;
+
+ /*
+ * Zone reset does not include bi_size so bio_sectors() is always 0.
+ * Include a test for the reset op code and perform the remap if needed.
+ */
+ if (!bio->bi_partno ||
+ (!bio_sectors(bio) && bio_op(bio) != REQ_OP_ZONE_RESET))
+ return 0;
+
+ rcu_read_lock();
+ p = __disk_get_part(bio->bi_disk, bio->bi_partno);
+ if (likely(p && !should_fail_request(p, bio->bi_iter.bi_size))) {
+ bio->bi_iter.bi_sector += p->start_sect;
+ bio->bi_partno = 0;
+ trace_block_bio_remap(bio->bi_disk->queue, bio, part_devt(p),
+ bio->bi_iter.bi_sector - p->start_sect);
+ } else {
+ printk("%s: fail for partition %d\n", __func__, bio->bi_partno);
+ ret = -EIO;
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
+/*
+ * Check whether this bio extends beyond the end of the device.
+ */
+static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)
+{
+ sector_t maxsector;
+
+ if (!nr_sectors)
+ return 0;
+
+ /* Test device or partition size, when known. */
+ maxsector = get_capacity(bio->bi_disk);
+ if (maxsector) {
+ sector_t sector = bio->bi_iter.bi_sector;
+
+ if (maxsector < nr_sectors || maxsector - nr_sectors < sector) {
+ /*
+ * This may well happen - the kernel calls bread()
+ * without checking the size of the device, e.g., when
+ * mounting a device.
+ */
+ handle_bad_sector(bio);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+static noinline_for_stack bool
+generic_make_request_checks(struct bio *bio)
+{
+ struct request_queue *q;
+ int nr_sectors = bio_sectors(bio);
+ blk_status_t status = BLK_STS_IOERR;
+ char b[BDEVNAME_SIZE];
+
+ might_sleep();
+
+ if (bio_check_eod(bio, nr_sectors))
+ goto end_io;
+
+ q = bio->bi_disk->queue;
+ if (unlikely(!q)) {
+ printk(KERN_ERR
+ "generic_make_request: Trying to access "
+ "nonexistent block-device %s (%Lu)\n",
+ bio_devname(bio, b), (long long)bio->bi_iter.bi_sector);
+ goto end_io;
+ }
+
+ /*
+ * For a REQ_NOWAIT based request, return -EOPNOTSUPP
+ * if queue is not a request based queue.
+ */
+
+ if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_rq_based(q))
+ goto not_supported;
+
+ if (should_fail_request(&bio->bi_disk->part0, bio->bi_iter.bi_size))
+ goto end_io;
+
+ if (blk_partition_remap(bio))
+ goto end_io;
+
+ if (bio_check_eod(bio, nr_sectors))
+ goto end_io;
+
+ /*
+ * Filter flush bio's early so that make_request based
+ * drivers without flush support don't have to worry
+ * about them.
+ */
+ if (op_is_flush(bio->bi_opf) &&
+ !test_bit(QUEUE_FLAG_WC, &q->queue_flags)) {
+ bio->bi_opf &= ~(REQ_PREFLUSH | REQ_FUA);
+ if (!nr_sectors) {
+ status = BLK_STS_OK;
+ goto end_io;
+ }
+ }
+
+ switch (bio_op(bio)) {
+ case REQ_OP_DISCARD:
+ if (!blk_queue_discard(q))
+ goto not_supported;
+ break;
+ case REQ_OP_SECURE_ERASE:
+ if (!blk_queue_secure_erase(q))
+ goto not_supported;
+ break;
+ case REQ_OP_WRITE_SAME:
+ if (!q->limits.max_write_same_sectors)
+ goto not_supported;
+ break;
+ case REQ_OP_ZONE_REPORT:
+ case REQ_OP_ZONE_RESET:
+ if (!blk_queue_is_zoned(q))
+ goto not_supported;
+ break;
+ case REQ_OP_WRITE_ZEROES:
+ if (!q->limits.max_write_zeroes_sectors)
+ goto not_supported;
+ break;
+ default:
+ break;
+ }
+
+ /*
+ * Various block parts want %current->io_context and lazy ioc
+ * allocation ends up trading a lot of pain for a small amount of
+ * memory. Just allocate it upfront. This may fail and block
+ * layer knows how to live with it.
+ */
+ create_io_context(GFP_ATOMIC, q->node);
+
+ if (!blkcg_bio_issue_check(q, bio))
+ return false;
+
+ if (!bio_flagged(bio, BIO_TRACE_COMPLETION)) {
+ trace_block_bio_queue(q, bio);
+ /* Now that enqueuing has been traced, we need to trace
+ * completion as well.
+ */
+ bio_set_flag(bio, BIO_TRACE_COMPLETION);
+ }
+ return true;
+
+not_supported:
+ status = BLK_STS_NOTSUPP;
+end_io:
+ bio->bi_status = status;
+ bio_endio(bio);
+ return false;
+}
+
+/**
+ * generic_make_request - hand a buffer to its device driver for I/O
+ * @bio: The bio describing the location in memory and on the device.
+ *
+ * generic_make_request() is used to make I/O requests of block
+ * devices. It is passed a &struct bio, which describes the I/O that needs
+ * to be done.
+ *
+ * generic_make_request() does not return any status. The
+ * success/failure status of the request, along with notification of
+ * completion, is delivered asynchronously through the bio->bi_end_io
+ * function described (one day) else where.
+ *
+ * The caller of generic_make_request must make sure that bi_io_vec
+ * are set to describe the memory buffer, and that bi_dev and bi_sector are
+ * set to describe the device address, and the
+ * bi_end_io and optionally bi_private are set to describe how
+ * completion notification should be signaled.
+ *
+ * generic_make_request and the drivers it calls may use bi_next if this
+ * bio happens to be merged with someone else, and may resubmit the bio to
+ * a lower device by calling into generic_make_request recursively, which
+ * means the bio should NOT be touched after the call to ->make_request_fn.
+ */
+blk_qc_t generic_make_request(struct bio *bio)
+{
+ /*
+ * bio_list_on_stack[0] contains bios submitted by the current
+ * make_request_fn.
+ * bio_list_on_stack[1] contains bios that were submitted before
+ * the current make_request_fn, but that haven't been processed
+ * yet.
+ */
+ struct bio_list bio_list_on_stack[2];
+ blk_qc_t ret = BLK_QC_T_NONE;
+
+ if (!generic_make_request_checks(bio))
+ goto out;
+
+ /*
+ * We only want one ->make_request_fn to be active at a time, else
+ * stack usage with stacked devices could be a problem. So use
+ * current->bio_list to keep a list of requests submited by a
+ * make_request_fn function. current->bio_list is also used as a
+ * flag to say if generic_make_request is currently active in this
+ * task or not. If it is NULL, then no make_request is active. If
+ * it is non-NULL, then a make_request is active, and new requests
+ * should be added at the tail
+ */
+ if (current->bio_list) {
+ bio_list_add(¤t->bio_list[0], bio);
+ goto out;
+ }
+
+ /* following loop may be a bit non-obvious, and so deserves some
+ * explanation.
+ * Before entering the loop, bio->bi_next is NULL (as all callers
+ * ensure that) so we have a list with a single bio.
+ * We pretend that we have just taken it off a longer list, so
+ * we assign bio_list to a pointer to the bio_list_on_stack,
+ * thus initialising the bio_list of new bios to be
+ * added. ->make_request() may indeed add some more bios
+ * through a recursive call to generic_make_request. If it
+ * did, we find a non-NULL value in bio_list and re-enter the loop
+ * from the top. In this case we really did just take the bio
+ * of the top of the list (no pretending) and so remove it from
+ * bio_list, and call into ->make_request() again.
+ */
+ BUG_ON(bio->bi_next);
+ bio_list_init(&bio_list_on_stack[0]);
+ current->bio_list = bio_list_on_stack;
+ do {
+ struct request_queue *q = bio->bi_disk->queue;
+
+ if (likely(blk_queue_enter(q, bio->bi_opf & REQ_NOWAIT) == 0)) {
+ struct bio_list lower, same;
+
+ /* Create a fresh bio_list for all subordinate requests */
+ bio_list_on_stack[1] = bio_list_on_stack[0];
+ bio_list_init(&bio_list_on_stack[0]);
+ ret = q->make_request_fn(q, bio);
+
+ blk_queue_exit(q);
+
+ /* sort new bios into those for a lower level
+ * and those for the same level
+ */
+ bio_list_init(&lower);
+ bio_list_init(&same);
+ while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL)
+ if (q == bio->bi_disk->queue)
+ bio_list_add(&same, bio);
+ else
+ bio_list_add(&lower, bio);
+ /* now assemble so we handle the lowest level first */
+ bio_list_merge(&bio_list_on_stack[0], &lower);
+ bio_list_merge(&bio_list_on_stack[0], &same);
+ bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]);
+ } else {
+ if (unlikely(!blk_queue_dying(q) &&
+ (bio->bi_opf & REQ_NOWAIT)))
+ bio_wouldblock_error(bio);
+ else
+ bio_io_error(bio);
+ }
+ bio = bio_list_pop(&bio_list_on_stack[0]);
+ } while (bio);
+ current->bio_list = NULL; /* deactivate */
+
+out:
+ return ret;
+}
+EXPORT_SYMBOL(generic_make_request);
+
+/**
+ * submit_bio - submit a bio to the block device layer for I/O
+ * @bio: The &struct bio which describes the I/O
+ *
+ * submit_bio() is very similar in purpose to generic_make_request(), and
+ * uses that function to do most of the work. Both are fairly rough
+ * interfaces; @bio must be presetup and ready for I/O.
+ *
+ */
+blk_qc_t submit_bio(struct bio *bio)
+{
+ /*
+ * If it's a regular read/write or a barrier with data attached,
+ * go through the normal accounting stuff before submission.
+ */
+ if (bio_has_data(bio)) {
+ unsigned int count;
+
+ if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))
+ count = queue_logical_block_size(bio->bi_disk->queue) >> 9;
+ else
+ count = bio_sectors(bio);
+
+ if (op_is_write(bio_op(bio))) {
+ count_vm_events(PGPGOUT, count);
+ } else {
+ task_io_account_read(bio->bi_iter.bi_size);
+ count_vm_events(PGPGIN, count);
+ }
+
+ if (unlikely(block_dump)) {
+ char b[BDEVNAME_SIZE];
+ printk(KERN_DEBUG "%s(%d): %s block %Lu on %s (%u sectors)\n",
+ current->comm, task_pid_nr(current),
+ op_is_write(bio_op(bio)) ? "WRITE" : "READ",
+ (unsigned long long)bio->bi_iter.bi_sector,
+ bio_devname(bio, b), count);
+ }
+ }
+
+ return generic_make_request(bio);
+}
+EXPORT_SYMBOL(submit_bio);
+
+/**
+ * blk_cloned_rq_check_limits - Helper function to check a cloned request
+ * for new the queue limits
+ * @q: the queue
+ * @rq: the request being checked
+ *
+ * Description:
+ * @rq may have been made based on weaker limitations of upper-level queues
+ * in request stacking drivers, and it may violate the limitation of @q.
+ * Since the block layer and the underlying device driver trust @rq
+ * after it is inserted to @q, it should be checked against @q before
+ * the insertion using this generic function.
+ *
+ * Request stacking drivers like request-based dm may change the queue
+ * limits when retrying requests on other queues. Those requests need
+ * to be checked against the new queue limits again during dispatch.
+ */
+static int blk_cloned_rq_check_limits(struct request_queue *q,
+ struct request *rq)
+{
+ if (blk_rq_sectors(rq) > blk_queue_get_max_sectors(q, req_op(rq))) {
+ printk(KERN_ERR "%s: over max size limit.\n", __func__);
+ return -EIO;
+ }
+
+ /*
+ * queue's settings related to segment counting like q->bounce_pfn
+ * may differ from that of other stacking queues.
+ * Recalculate it to check the request correctly on this queue's
+ * limitation.
+ */
+ blk_recalc_rq_segments(rq);
+ if (rq->nr_phys_segments > queue_max_segments(q)) {
+ printk(KERN_ERR "%s: over max segments limit.\n", __func__);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/**
+ * blk_insert_cloned_request - Helper for stacking drivers to submit a request
+ * @q: the queue to submit the request
+ * @rq: the request being queued
+ */
+blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq)
+{
+ unsigned long flags;
+ int where = ELEVATOR_INSERT_BACK;
+
+ if (blk_cloned_rq_check_limits(q, rq))
+ return BLK_STS_IOERR;
+
+ if (rq->rq_disk &&
+ should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq)))
+ return BLK_STS_IOERR;
+
+ if (q->mq_ops) {
+ if (blk_queue_io_stat(q))
+ blk_account_io_start(rq, true);
+ /*
+ * Since we have a scheduler attached on the top device,
+ * bypass a potential scheduler on the bottom device for
+ * insert.
+ */
+ blk_mq_request_bypass_insert(rq);
+ return BLK_STS_OK;
+ }
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ if (unlikely(blk_queue_dying(q))) {
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ return BLK_STS_IOERR;
+ }
+
+ /*
+ * Submitting request must be dequeued before calling this function
+ * because it will be linked to another request_queue
+ */
+ BUG_ON(blk_queued_rq(rq));
+
+ if (op_is_flush(rq->cmd_flags))
+ where = ELEVATOR_INSERT_FLUSH;
+
+ add_acct_request(q, rq, where);
+ if (where == ELEVATOR_INSERT_FLUSH)
+ __blk_run_queue(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ return BLK_STS_OK;
+}
+EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
+
+/**
+ * blk_rq_err_bytes - determine number of bytes till the next failure boundary
+ * @rq: request to examine
+ *
+ * Description:
+ * A request could be merge of IOs which require different failure
+ * handling. This function determines the number of bytes which
+ * can be failed from the beginning of the request without
+ * crossing into area which need to be retried further.
+ *
+ * Return:
+ * The number of bytes to fail.
+ */
+unsigned int blk_rq_err_bytes(const struct request *rq)
+{
+ unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK;
+ unsigned int bytes = 0;
+ struct bio *bio;
+
+ if (!(rq->rq_flags & RQF_MIXED_MERGE))
+ return blk_rq_bytes(rq);
+
+ /*
+ * Currently the only 'mixing' which can happen is between
+ * different fastfail types. We can safely fail portions
+ * which have all the failfast bits that the first one has -
+ * the ones which are at least as eager to fail as the first
+ * one.
+ */
+ for (bio = rq->bio; bio; bio = bio->bi_next) {
+ if ((bio->bi_opf & ff) != ff)
+ break;
+ bytes += bio->bi_iter.bi_size;
+ }
+
+ /* this could lead to infinite loop */
+ BUG_ON(blk_rq_bytes(rq) && !bytes);
+ return bytes;
+}
+EXPORT_SYMBOL_GPL(blk_rq_err_bytes);
+
+void blk_account_io_completion(struct request *req, unsigned int bytes)
+{
+ if (blk_do_io_stat(req)) {
+ const int rw = rq_data_dir(req);
+ struct hd_struct *part;
+ int cpu;
+
+ cpu = part_stat_lock();
+ part = req->part;
+ part_stat_add(cpu, part, sectors[rw], bytes >> 9);
+ part_stat_unlock();
+ }
+}
+
+void blk_account_io_done(struct request *req)
+{
+ /*
+ * Account IO completion. flush_rq isn't accounted as a
+ * normal IO on queueing nor completion. Accounting the
+ * containing request is enough.
+ */
+ if (blk_do_io_stat(req) && !(req->rq_flags & RQF_FLUSH_SEQ)) {
+ unsigned long duration = jiffies - req->start_time;
+ const int rw = rq_data_dir(req);
+ struct hd_struct *part;
+ int cpu;
+
+ cpu = part_stat_lock();
+ part = req->part;
+
+ part_stat_inc(cpu, part, ios[rw]);
+ part_stat_add(cpu, part, ticks[rw], duration);
+ part_round_stats(req->q, cpu, part);
+ part_dec_in_flight(req->q, part, rw);
+
+ hd_struct_put(part);
+ part_stat_unlock();
+ }
+}
+
+#ifdef CONFIG_PM
+/*
+ * Don't process normal requests when queue is suspended
+ * or in the process of suspending/resuming
+ */
+static struct request *blk_pm_peek_request(struct request_queue *q,
+ struct request *rq)
+{
+ if (q->dev && (q->rpm_status == RPM_SUSPENDED ||
+ (q->rpm_status != RPM_ACTIVE && !(rq->rq_flags & RQF_PM))))
+ return NULL;
+ else
+ return rq;
+}
+#else
+static inline struct request *blk_pm_peek_request(struct request_queue *q,
+ struct request *rq)
+{
+ return rq;
+}
+#endif
+
+void blk_account_io_start(struct request *rq, bool new_io)
+{
+ struct hd_struct *part;
+ int rw = rq_data_dir(rq);
+ int cpu;
+
+ if (!blk_do_io_stat(rq))
+ return;
+
+ cpu = part_stat_lock();
+
+ if (!new_io) {
+ part = rq->part;
+ part_stat_inc(cpu, part, merges[rw]);
+ } else {
+ part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
+ if (!hd_struct_try_get(part)) {
+ /*
+ * The partition is already being removed,
+ * the request will be accounted on the disk only
+ *
+ * We take a reference on disk->part0 although that
+ * partition will never be deleted, so we can treat
+ * it as any other partition.
+ */
+ part = &rq->rq_disk->part0;
+ hd_struct_get(part);
+ }
+ part_round_stats(rq->q, cpu, part);
+ part_inc_in_flight(rq->q, part, rw);
+ rq->part = part;
+ }
+
+ part_stat_unlock();
+}
+
+/**
+ * blk_peek_request - peek at the top of a request queue
+ * @q: request queue to peek at
+ *
+ * Description:
+ * Return the request at the top of @q. The returned request
+ * should be started using blk_start_request() before LLD starts
+ * processing it.
+ *
+ * Return:
+ * Pointer to the request at the top of @q if available. Null
+ * otherwise.
+ */
+struct request *blk_peek_request(struct request_queue *q)
+{
+ struct request *rq;
+ int ret;
+
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ while ((rq = __elv_next_request(q)) != NULL) {
+
+ rq = blk_pm_peek_request(q, rq);
+ if (!rq)
+ break;
+
+ if (!(rq->rq_flags & RQF_STARTED)) {
+ /*
+ * This is the first time the device driver
+ * sees this request (possibly after
+ * requeueing). Notify IO scheduler.
+ */
+ if (rq->rq_flags & RQF_SORTED)
+ elv_activate_rq(q, rq);
+
+ /*
+ * just mark as started even if we don't start
+ * it, a request that has been delayed should
+ * not be passed by new incoming requests
+ */
+ rq->rq_flags |= RQF_STARTED;
+ trace_block_rq_issue(q, rq);
+ }
+
+ if (!q->boundary_rq || q->boundary_rq == rq) {
+ q->end_sector = rq_end_sector(rq);
+ q->boundary_rq = NULL;
+ }
+
+ if (rq->rq_flags & RQF_DONTPREP)
+ break;
+
+ if (q->dma_drain_size && blk_rq_bytes(rq)) {
+ /*
+ * make sure space for the drain appears we
+ * know we can do this because max_hw_segments
+ * has been adjusted to be one fewer than the
+ * device can handle
+ */
+ rq->nr_phys_segments++;
+ }
+
+ if (!q->prep_rq_fn)
+ break;
+
+ ret = q->prep_rq_fn(q, rq);
+ if (ret == BLKPREP_OK) {
+ break;
+ } else if (ret == BLKPREP_DEFER) {
+ /*
+ * the request may have been (partially) prepped.
+ * we need to keep this request in the front to
+ * avoid resource deadlock. RQF_STARTED will
+ * prevent other fs requests from passing this one.
+ */
+ if (q->dma_drain_size && blk_rq_bytes(rq) &&
+ !(rq->rq_flags & RQF_DONTPREP)) {
+ /*
+ * remove the space for the drain we added
+ * so that we don't add it again
+ */
+ --rq->nr_phys_segments;
+ }
+
+ rq = NULL;
+ break;
+ } else if (ret == BLKPREP_KILL || ret == BLKPREP_INVALID) {
+ rq->rq_flags |= RQF_QUIET;
+ /*
+ * Mark this request as started so we don't trigger
+ * any debug logic in the end I/O path.
+ */
+ blk_start_request(rq);
+ __blk_end_request_all(rq, ret == BLKPREP_INVALID ?
+ BLK_STS_TARGET : BLK_STS_IOERR);
+ } else {
+ printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
+ break;
+ }
+ }
+
+ return rq;
+}
+EXPORT_SYMBOL(blk_peek_request);
+
+static void blk_dequeue_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+
+ BUG_ON(list_empty(&rq->queuelist));
+ BUG_ON(ELV_ON_HASH(rq));
+
+ list_del_init(&rq->queuelist);
+
+ /*
+ * the time frame between a request being removed from the lists
+ * and to it is freed is accounted as io that is in progress at
+ * the driver side.
+ */
+ if (blk_account_rq(rq)) {
+ q->in_flight[rq_is_sync(rq)]++;
+ set_io_start_time_ns(rq);
+ }
+}
+
+/**
+ * blk_start_request - start request processing on the driver
+ * @req: request to dequeue
+ *
+ * Description:
+ * Dequeue @req and start timeout timer on it. This hands off the
+ * request to the driver.
+ */
+void blk_start_request(struct request *req)
+{
+ lockdep_assert_held(req->q->queue_lock);
+ WARN_ON_ONCE(req->q->mq_ops);
+
+ blk_dequeue_request(req);
+
+ if (test_bit(QUEUE_FLAG_STATS, &req->q->queue_flags)) {
+ blk_stat_set_issue(&req->issue_stat, blk_rq_sectors(req));
+ req->rq_flags |= RQF_STATS;
+ wbt_issue(req->q->rq_wb, &req->issue_stat);
+ }
+
+ BUG_ON(test_bit(REQ_ATOM_COMPLETE, &req->atomic_flags));
+ blk_add_timer(req);
+}
+EXPORT_SYMBOL(blk_start_request);
+
+/**
+ * blk_fetch_request - fetch a request from a request queue
+ * @q: request queue to fetch a request from
+ *
+ * Description:
+ * Return the request at the top of @q. The request is started on
+ * return and LLD can start processing it immediately.
+ *
+ * Return:
+ * Pointer to the request at the top of @q if available. Null
+ * otherwise.
+ */
+struct request *blk_fetch_request(struct request_queue *q)
+{
+ struct request *rq;
+
+ lockdep_assert_held(q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ rq = blk_peek_request(q);
+ if (rq)
+ blk_start_request(rq);
+ return rq;
+}
+EXPORT_SYMBOL(blk_fetch_request);
+
+/**
+ * blk_update_request - Special helper function for request stacking drivers
+ * @req: the request being processed
+ * @error: block status code
+ * @nr_bytes: number of bytes to complete @req
+ *
+ * Description:
+ * Ends I/O on a number of bytes attached to @req, but doesn't complete
+ * the request structure even if @req doesn't have leftover.
+ * If @req has leftover, sets it up for the next range of segments.
+ *
+ * This special helper function is only for request stacking drivers
+ * (e.g. request-based dm) so that they can handle partial completion.
+ * Actual device drivers should use blk_end_request instead.
+ *
+ * Passing the result of blk_rq_bytes() as @nr_bytes guarantees
+ * %false return from this function.
+ *
+ * Return:
+ * %false - this request doesn't have any more data
+ * %true - this request has more data
+ **/
+bool blk_update_request(struct request *req, blk_status_t error,
+ unsigned int nr_bytes)
+{
+ int total_bytes;
+
+ trace_block_rq_complete(req, blk_status_to_errno(error), nr_bytes);
+
+ if (!req->bio)
+ return false;
+
+ if (unlikely(error && !blk_rq_is_passthrough(req) &&
+ !(req->rq_flags & RQF_QUIET)))
+ print_req_error(req, error);
+
+ blk_account_io_completion(req, nr_bytes);
+
+ total_bytes = 0;
+ while (req->bio) {
+ struct bio *bio = req->bio;
+ unsigned bio_bytes = min(bio->bi_iter.bi_size, nr_bytes);
+
+ if (bio_bytes == bio->bi_iter.bi_size)
+ req->bio = bio->bi_next;
+
+ /* Completion has already been traced */
+ bio_clear_flag(bio, BIO_TRACE_COMPLETION);
+ req_bio_endio(req, bio, bio_bytes, error);
+
+ total_bytes += bio_bytes;
+ nr_bytes -= bio_bytes;
+
+ if (!nr_bytes)
+ break;
+ }
+
+ /*
+ * completely done
+ */
+ if (!req->bio) {
+ /*
+ * Reset counters so that the request stacking driver
+ * can find how many bytes remain in the request
+ * later.
+ */
+ req->__data_len = 0;
+ return false;
+ }
+
+ req->__data_len -= total_bytes;
+
+ /* update sector only for requests with clear definition of sector */
+ if (!blk_rq_is_passthrough(req))
+ req->__sector += total_bytes >> 9;
+
+ /* mixed attributes always follow the first bio */
+ if (req->rq_flags & RQF_MIXED_MERGE) {
+ req->cmd_flags &= ~REQ_FAILFAST_MASK;
+ req->cmd_flags |= req->bio->bi_opf & REQ_FAILFAST_MASK;
+ }
+
+ if (!(req->rq_flags & RQF_SPECIAL_PAYLOAD)) {
+ /*
+ * If total number of sectors is less than the first segment
+ * size, something has gone terribly wrong.
+ */
+ if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) {
+ blk_dump_rq_flags(req, "request botched");
+ req->__data_len = blk_rq_cur_bytes(req);
+ }
+
+ /* recalculate the number of segments */
+ blk_recalc_rq_segments(req);
+ }
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(blk_update_request);
+
+static bool blk_update_bidi_request(struct request *rq, blk_status_t error,
+ unsigned int nr_bytes,
+ unsigned int bidi_bytes)
+{
+ if (blk_update_request(rq, error, nr_bytes))
+ return true;
+
+ /* Bidi request must be completed as a whole */
+ if (unlikely(blk_bidi_rq(rq)) &&
+ blk_update_request(rq->next_rq, error, bidi_bytes))
+ return true;
+
+ if (blk_queue_add_random(rq->q))
+ add_disk_randomness(rq->rq_disk);
+
+ return false;
+}
+
+/**
+ * blk_unprep_request - unprepare a request
+ * @req: the request
+ *
+ * This function makes a request ready for complete resubmission (or
+ * completion). It happens only after all error handling is complete,
+ * so represents the appropriate moment to deallocate any resources
+ * that were allocated to the request in the prep_rq_fn. The queue
+ * lock is held when calling this.
+ */
+void blk_unprep_request(struct request *req)
+{
+ struct request_queue *q = req->q;
+
+ req->rq_flags &= ~RQF_DONTPREP;
+ if (q->unprep_rq_fn)
+ q->unprep_rq_fn(q, req);
+}
+EXPORT_SYMBOL_GPL(blk_unprep_request);
+
+void blk_finish_request(struct request *req, blk_status_t error)
+{
+ struct request_queue *q = req->q;
+
+ lockdep_assert_held(req->q->queue_lock);
+ WARN_ON_ONCE(q->mq_ops);
+
+ if (req->rq_flags & RQF_STATS)
+ blk_stat_add(req);
+
+ if (req->rq_flags & RQF_QUEUED)
+ blk_queue_end_tag(q, req);
+
+ BUG_ON(blk_queued_rq(req));
+
+ if (unlikely(laptop_mode) && !blk_rq_is_passthrough(req))
+ laptop_io_completion(req->q->backing_dev_info);
+
+ blk_delete_timer(req);
+
+ if (req->rq_flags & RQF_DONTPREP)
+ blk_unprep_request(req);
+
+ blk_account_io_done(req);
+
+ if (req->end_io) {
+ wbt_done(req->q->rq_wb, &req->issue_stat);
+ req->end_io(req, error);
+ } else {
+ if (blk_bidi_rq(req))
+ __blk_put_request(req->next_rq->q, req->next_rq);
+
+ __blk_put_request(q, req);
+ }
+}
+EXPORT_SYMBOL(blk_finish_request);
+
+/**
+ * blk_end_bidi_request - Complete a bidi request
+ * @rq: the request to complete
+ * @error: block status code
+ * @nr_bytes: number of bytes to complete @rq
+ * @bidi_bytes: number of bytes to complete @rq->next_rq
+ *
+ * Description:
+ * Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
+ * Drivers that supports bidi can safely call this member for any
+ * type of request, bidi or uni. In the later case @bidi_bytes is
+ * just ignored.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ **/
+static bool blk_end_bidi_request(struct request *rq, blk_status_t error,
+ unsigned int nr_bytes, unsigned int bidi_bytes)
+{
+ struct request_queue *q = rq->q;
+ unsigned long flags;
+
+ WARN_ON_ONCE(q->mq_ops);
+
+ if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
+ return true;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ blk_finish_request(rq, error);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ return false;
+}
+
+/**
+ * __blk_end_bidi_request - Complete a bidi request with queue lock held
+ * @rq: the request to complete
+ * @error: block status code
+ * @nr_bytes: number of bytes to complete @rq
+ * @bidi_bytes: number of bytes to complete @rq->next_rq
+ *
+ * Description:
+ * Identical to blk_end_bidi_request() except that queue lock is
+ * assumed to be locked on entry and remains so on return.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ **/
+static bool __blk_end_bidi_request(struct request *rq, blk_status_t error,
+ unsigned int nr_bytes, unsigned int bidi_bytes)
+{
+ lockdep_assert_held(rq->q->queue_lock);
+ WARN_ON_ONCE(rq->q->mq_ops);
+
+ if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
+ return true;
+
+ blk_finish_request(rq, error);
+
+ return false;
+}
+
+/**
+ * blk_end_request - Helper function for drivers to complete the request.
+ * @rq: the request being processed
+ * @error: block status code
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ * Ends I/O on a number of bytes attached to @rq.
+ * If @rq has leftover, sets it up for the next range of segments.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ **/
+bool blk_end_request(struct request *rq, blk_status_t error,
+ unsigned int nr_bytes)
+{
+ WARN_ON_ONCE(rq->q->mq_ops);
+ return blk_end_bidi_request(rq, error, nr_bytes, 0);
+}
+EXPORT_SYMBOL(blk_end_request);
+
+/**
+ * blk_end_request_all - Helper function for drives to finish the request.
+ * @rq: the request to finish
+ * @error: block status code
+ *
+ * Description:
+ * Completely finish @rq.
+ */
+void blk_end_request_all(struct request *rq, blk_status_t error)
+{
+ bool pending;
+ unsigned int bidi_bytes = 0;
+
+ if (unlikely(blk_bidi_rq(rq)))
+ bidi_bytes = blk_rq_bytes(rq->next_rq);
+
+ pending = blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes);
+ BUG_ON(pending);
+}
+EXPORT_SYMBOL(blk_end_request_all);
+
+/**
+ * __blk_end_request - Helper function for drivers to complete the request.
+ * @rq: the request being processed
+ * @error: block status code
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ * Must be called with queue lock held unlike blk_end_request().
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ **/
+bool __blk_end_request(struct request *rq, blk_status_t error,
+ unsigned int nr_bytes)
+{
+ lockdep_assert_held(rq->q->queue_lock);
+ WARN_ON_ONCE(rq->q->mq_ops);
+
+ return __blk_end_bidi_request(rq, error, nr_bytes, 0);
+}
+EXPORT_SYMBOL(__blk_end_request);
+
+/**
+ * __blk_end_request_all - Helper function for drives to finish the request.
+ * @rq: the request to finish
+ * @error: block status code
+ *
+ * Description:
+ * Completely finish @rq. Must be called with queue lock held.
+ */
+void __blk_end_request_all(struct request *rq, blk_status_t error)
+{
+ bool pending;
+ unsigned int bidi_bytes = 0;
+
+ lockdep_assert_held(rq->q->queue_lock);
+ WARN_ON_ONCE(rq->q->mq_ops);
+
+ if (unlikely(blk_bidi_rq(rq)))
+ bidi_bytes = blk_rq_bytes(rq->next_rq);
+
+ pending = __blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes);
+ BUG_ON(pending);
+}
+EXPORT_SYMBOL(__blk_end_request_all);
+
+/**
+ * __blk_end_request_cur - Helper function to finish the current request chunk.
+ * @rq: the request to finish the current chunk for
+ * @error: block status code
+ *
+ * Description:
+ * Complete the current consecutively mapped chunk from @rq. Must
+ * be called with queue lock held.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ */
+bool __blk_end_request_cur(struct request *rq, blk_status_t error)
+{
+ return __blk_end_request(rq, error, blk_rq_cur_bytes(rq));
+}
+EXPORT_SYMBOL(__blk_end_request_cur);
+
+void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
+ struct bio *bio)
+{
+ if (bio_has_data(bio))
+ rq->nr_phys_segments = bio_phys_segments(q, bio);
+ else if (bio_op(bio) == REQ_OP_DISCARD)
+ rq->nr_phys_segments = 1;
+
+ rq->__data_len = bio->bi_iter.bi_size;
+ rq->bio = rq->biotail = bio;
+
+ if (bio->bi_disk)
+ rq->rq_disk = bio->bi_disk;
+}
+
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+/**
+ * rq_flush_dcache_pages - Helper function to flush all pages in a request
+ * @rq: the request to be flushed
+ *
+ * Description:
+ * Flush all pages in @rq.
+ */
+void rq_flush_dcache_pages(struct request *rq)
+{
+ struct req_iterator iter;
+ struct bio_vec bvec;
+
+ rq_for_each_segment(bvec, rq, iter)
+ flush_dcache_page(bvec.bv_page);
+}
+EXPORT_SYMBOL_GPL(rq_flush_dcache_pages);
+#endif
+
+/**
+ * blk_lld_busy - Check if underlying low-level drivers of a device are busy
+ * @q : the queue of the device being checked
+ *
+ * Description:
+ * Check if underlying low-level drivers of a device are busy.
+ * If the drivers want to export their busy state, they must set own
+ * exporting function using blk_queue_lld_busy() first.
+ *
+ * Basically, this function is used only by request stacking drivers
+ * to stop dispatching requests to underlying devices when underlying
+ * devices are busy. This behavior helps more I/O merging on the queue
+ * of the request stacking driver and prevents I/O throughput regression
+ * on burst I/O load.
+ *
+ * Return:
+ * 0 - Not busy (The request stacking driver should dispatch request)
+ * 1 - Busy (The request stacking driver should stop dispatching request)
+ */
+int blk_lld_busy(struct request_queue *q)
+{
+ if (q->lld_busy_fn)
+ return q->lld_busy_fn(q);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blk_lld_busy);
+
+/**
+ * blk_rq_unprep_clone - Helper function to free all bios in a cloned request
+ * @rq: the clone request to be cleaned up
+ *
+ * Description:
+ * Free all bios in @rq for a cloned request.
+ */
+void blk_rq_unprep_clone(struct request *rq)
+{
+ struct bio *bio;
+
+ while ((bio = rq->bio) != NULL) {
+ rq->bio = bio->bi_next;
+
+ bio_put(bio);
+ }
+}
+EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
+
+/*
+ * Copy attributes of the original request to the clone request.
+ * The actual data parts (e.g. ->cmd, ->sense) are not copied.
+ */
+static void __blk_rq_prep_clone(struct request *dst, struct request *src)
+{
+ dst->cpu = src->cpu;
+ dst->__sector = blk_rq_pos(src);
+ dst->__data_len = blk_rq_bytes(src);
+ if (src->rq_flags & RQF_SPECIAL_PAYLOAD) {
+ dst->rq_flags |= RQF_SPECIAL_PAYLOAD;
+ dst->special_vec = src->special_vec;
+ }
+ dst->nr_phys_segments = src->nr_phys_segments;
+ dst->ioprio = src->ioprio;
+ dst->extra_len = src->extra_len;
+}
+
+/**
+ * blk_rq_prep_clone - Helper function to setup clone request
+ * @rq: the request to be setup
+ * @rq_src: original request to be cloned
+ * @bs: bio_set that bios for clone are allocated from
+ * @gfp_mask: memory allocation mask for bio
+ * @bio_ctr: setup function to be called for each clone bio.
+ * Returns %0 for success, non %0 for failure.
+ * @data: private data to be passed to @bio_ctr
+ *
+ * Description:
+ * Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq.
+ * The actual data parts of @rq_src (e.g. ->cmd, ->sense)
+ * are not copied, and copying such parts is the caller's responsibility.
+ * Also, pages which the original bios are pointing to are not copied
+ * and the cloned bios just point same pages.
+ * So cloned bios must be completed before original bios, which means
+ * the caller must complete @rq before @rq_src.
+ */
+int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
+ struct bio_set *bs, gfp_t gfp_mask,
+ int (*bio_ctr)(struct bio *, struct bio *, void *),
+ void *data)
+{
+ struct bio *bio, *bio_src;
+
+ if (!bs)
+ bs = fs_bio_set;
+
+ __rq_for_each_bio(bio_src, rq_src) {
+ bio = bio_clone_fast(bio_src, gfp_mask, bs);
+ if (!bio)
+ goto free_and_out;
+
+ if (bio_ctr && bio_ctr(bio, bio_src, data))
+ goto free_and_out;
+
+ if (rq->bio) {
+ rq->biotail->bi_next = bio;
+ rq->biotail = bio;
+ } else
+ rq->bio = rq->biotail = bio;
+ }
+
+ __blk_rq_prep_clone(rq, rq_src);
+
+ return 0;
+
+free_and_out:
+ if (bio)
+ bio_put(bio);
+ blk_rq_unprep_clone(rq);
+
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(blk_rq_prep_clone);
+
+int kblockd_schedule_work(struct work_struct *work)
+{
+ return queue_work(kblockd_workqueue, work);
+}
+EXPORT_SYMBOL(kblockd_schedule_work);
+
+int kblockd_schedule_work_on(int cpu, struct work_struct *work)
+{
+ return queue_work_on(cpu, kblockd_workqueue, work);
+}
+EXPORT_SYMBOL(kblockd_schedule_work_on);
+
+int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork,
+ unsigned long delay)
+{
+ return mod_delayed_work_on(cpu, kblockd_workqueue, dwork, delay);
+}
+EXPORT_SYMBOL(kblockd_mod_delayed_work_on);
+
+int kblockd_schedule_delayed_work(struct delayed_work *dwork,
+ unsigned long delay)
+{
+ return queue_delayed_work(kblockd_workqueue, dwork, delay);
+}
+EXPORT_SYMBOL(kblockd_schedule_delayed_work);
+
+int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork,
+ unsigned long delay)
+{
+ return queue_delayed_work_on(cpu, kblockd_workqueue, dwork, delay);
+}
+EXPORT_SYMBOL(kblockd_schedule_delayed_work_on);
+
+/**
+ * blk_start_plug - initialize blk_plug and track it inside the task_struct
+ * @plug: The &struct blk_plug that needs to be initialized
+ *
+ * Description:
+ * Tracking blk_plug inside the task_struct will help with auto-flushing the
+ * pending I/O should the task end up blocking between blk_start_plug() and
+ * blk_finish_plug(). This is important from a performance perspective, but
+ * also ensures that we don't deadlock. For instance, if the task is blocking
+ * for a memory allocation, memory reclaim could end up wanting to free a
+ * page belonging to that request that is currently residing in our private
+ * plug. By flushing the pending I/O when the process goes to sleep, we avoid
+ * this kind of deadlock.
+ */
+void blk_start_plug(struct blk_plug *plug)
+{
+ struct task_struct *tsk = current;
+
+ /*
+ * If this is a nested plug, don't actually assign it.
+ */
+ if (tsk->plug)
+ return;
+
+ INIT_LIST_HEAD(&plug->list);
+ INIT_LIST_HEAD(&plug->mq_list);
+ INIT_LIST_HEAD(&plug->cb_list);
+ /*
+ * Store ordering should not be needed here, since a potential
+ * preempt will imply a full memory barrier
+ */
+ tsk->plug = plug;
+}
+EXPORT_SYMBOL(blk_start_plug);
+
+static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct request *rqa = container_of(a, struct request, queuelist);
+ struct request *rqb = container_of(b, struct request, queuelist);
+
+ return !(rqa->q < rqb->q ||
+ (rqa->q == rqb->q && blk_rq_pos(rqa) < blk_rq_pos(rqb)));
+}
+
+/*
+ * If 'from_schedule' is true, then postpone the dispatch of requests
+ * until a safe kblockd context. We due this to avoid accidental big
+ * additional stack usage in driver dispatch, in places where the originally
+ * plugger did not intend it.
+ */
+static void queue_unplugged(struct request_queue *q, unsigned int depth,
+ bool from_schedule)
+ __releases(q->queue_lock)
+{
+ lockdep_assert_held(q->queue_lock);
+
+ trace_block_unplug(q, depth, !from_schedule);
+
+ if (from_schedule)
+ blk_run_queue_async(q);
+ else
+ __blk_run_queue(q);
+ spin_unlock(q->queue_lock);
+}
+
+static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule)
+{
+ LIST_HEAD(callbacks);
+
+ while (!list_empty(&plug->cb_list)) {
+ list_splice_init(&plug->cb_list, &callbacks);
+
+ while (!list_empty(&callbacks)) {
+ struct blk_plug_cb *cb = list_first_entry(&callbacks,
+ struct blk_plug_cb,
+ list);
+ list_del(&cb->list);
+ cb->callback(cb, from_schedule);
+ }
+ }
+}
+
+struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data,
+ int size)
+{
+ struct blk_plug *plug = current->plug;
+ struct blk_plug_cb *cb;
+
+ if (!plug)
+ return NULL;
+
+ list_for_each_entry(cb, &plug->cb_list, list)
+ if (cb->callback == unplug && cb->data == data)
+ return cb;
+
+ /* Not currently on the callback list */
+ BUG_ON(size < sizeof(*cb));
+ cb = kzalloc(size, GFP_ATOMIC);
+ if (cb) {
+ cb->data = data;
+ cb->callback = unplug;
+ list_add(&cb->list, &plug->cb_list);
+ }
+ return cb;
+}
+EXPORT_SYMBOL(blk_check_plugged);
+
+void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
+{
+ struct request_queue *q;
+ unsigned long flags;
+ struct request *rq;
+ LIST_HEAD(list);
+ unsigned int depth;
+
+ flush_plug_callbacks(plug, from_schedule);
+
+ if (!list_empty(&plug->mq_list))
+ blk_mq_flush_plug_list(plug, from_schedule);
+
+ if (list_empty(&plug->list))
+ return;
+
+ list_splice_init(&plug->list, &list);
+
+ list_sort(NULL, &list, plug_rq_cmp);
+
+ q = NULL;
+ depth = 0;
+
+ /*
+ * Save and disable interrupts here, to avoid doing it for every
+ * queue lock we have to take.
+ */
+ local_irq_save(flags);
+ while (!list_empty(&list)) {
+ rq = list_entry_rq(list.next);
+ list_del_init(&rq->queuelist);
+ BUG_ON(!rq->q);
+ if (rq->q != q) {
+ /*
+ * This drops the queue lock
+ */
+ if (q)
+ queue_unplugged(q, depth, from_schedule);
+ q = rq->q;
+ depth = 0;
+ spin_lock(q->queue_lock);
+ }
+
+ /*
+ * Short-circuit if @q is dead
+ */
+ if (unlikely(blk_queue_dying(q))) {
+ __blk_end_request_all(rq, BLK_STS_IOERR);
+ continue;
+ }
+
+ /*
+ * rq is already accounted, so use raw insert
+ */
+ if (op_is_flush(rq->cmd_flags))
+ __elv_add_request(q, rq, ELEVATOR_INSERT_FLUSH);
+ else
+ __elv_add_request(q, rq, ELEVATOR_INSERT_SORT_MERGE);
+
+ depth++;
+ }
+
+ /*
+ * This drops the queue lock
+ */
+ if (q)
+ queue_unplugged(q, depth, from_schedule);
+
+ local_irq_restore(flags);
+}
+
+void blk_finish_plug(struct blk_plug *plug)
+{
+ if (plug != current->plug)
+ return;
+ blk_flush_plug_list(plug, false);
+
+ current->plug = NULL;
+}
+EXPORT_SYMBOL(blk_finish_plug);
+
+#ifdef CONFIG_PM
+/**
+ * blk_pm_runtime_init - Block layer runtime PM initialization routine
+ * @q: the queue of the device
+ * @dev: the device the queue belongs to
+ *
+ * Description:
+ * Initialize runtime-PM-related fields for @q and start auto suspend for
+ * @dev. Drivers that want to take advantage of request-based runtime PM
+ * should call this function after @dev has been initialized, and its
+ * request queue @q has been allocated, and runtime PM for it can not happen
+ * yet(either due to disabled/forbidden or its usage_count > 0). In most
+ * cases, driver should call this function before any I/O has taken place.
+ *
+ * This function takes care of setting up using auto suspend for the device,
+ * the autosuspend delay is set to -1 to make runtime suspend impossible
+ * until an updated value is either set by user or by driver. Drivers do
+ * not need to touch other autosuspend settings.
+ *
+ * The block layer runtime PM is request based, so only works for drivers
+ * that use request as their IO unit instead of those directly use bio's.
+ */
+void blk_pm_runtime_init(struct request_queue *q, struct device *dev)
+{
+ /* Don't enable runtime PM for blk-mq until it is ready */
+ if (q->mq_ops) {
+ pm_runtime_disable(dev);
+ return;
+ }
+
+ q->dev = dev;
+ q->rpm_status = RPM_ACTIVE;
+ pm_runtime_set_autosuspend_delay(q->dev, -1);
+ pm_runtime_use_autosuspend(q->dev);
+}
+EXPORT_SYMBOL(blk_pm_runtime_init);
+
+/**
+ * blk_pre_runtime_suspend - Pre runtime suspend check
+ * @q: the queue of the device
+ *
+ * Description:
+ * This function will check if runtime suspend is allowed for the device
+ * by examining if there are any requests pending in the queue. If there
+ * are requests pending, the device can not be runtime suspended; otherwise,
+ * the queue's status will be updated to SUSPENDING and the driver can
+ * proceed to suspend the device.
+ *
+ * For the not allowed case, we mark last busy for the device so that
+ * runtime PM core will try to autosuspend it some time later.
+ *
+ * This function should be called near the start of the device's
+ * runtime_suspend callback.
+ *
+ * Return:
+ * 0 - OK to runtime suspend the device
+ * -EBUSY - Device should not be runtime suspended
+ */
+int blk_pre_runtime_suspend(struct request_queue *q)
+{
+ int ret = 0;
+
+ if (!q->dev)
+ return ret;
+
+ spin_lock_irq(q->queue_lock);
+ if (q->nr_pending) {
+ ret = -EBUSY;
+ pm_runtime_mark_last_busy(q->dev);
+ } else {
+ q->rpm_status = RPM_SUSPENDING;
+ }
+ spin_unlock_irq(q->queue_lock);
+ return ret;
+}
+EXPORT_SYMBOL(blk_pre_runtime_suspend);
+
+/**
+ * blk_post_runtime_suspend - Post runtime suspend processing
+ * @q: the queue of the device
+ * @err: return value of the device's runtime_suspend function
+ *
+ * Description:
+ * Update the queue's runtime status according to the return value of the
+ * device's runtime suspend function and mark last busy for the device so
+ * that PM core will try to auto suspend the device at a later time.
+ *
+ * This function should be called near the end of the device's
+ * runtime_suspend callback.
+ */
+void blk_post_runtime_suspend(struct request_queue *q, int err)
+{
+ if (!q->dev)
+ return;
+
+ spin_lock_irq(q->queue_lock);
+ if (!err) {
+ q->rpm_status = RPM_SUSPENDED;
+ } else {
+ q->rpm_status = RPM_ACTIVE;
+ pm_runtime_mark_last_busy(q->dev);
+ }
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL(blk_post_runtime_suspend);
+
+/**
+ * blk_pre_runtime_resume - Pre runtime resume processing
+ * @q: the queue of the device
+ *
+ * Description:
+ * Update the queue's runtime status to RESUMING in preparation for the
+ * runtime resume of the device.
+ *
+ * This function should be called near the start of the device's
+ * runtime_resume callback.
+ */
+void blk_pre_runtime_resume(struct request_queue *q)
+{
+ if (!q->dev)
+ return;
+
+ spin_lock_irq(q->queue_lock);
+ q->rpm_status = RPM_RESUMING;
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL(blk_pre_runtime_resume);
+
+/**
+ * blk_post_runtime_resume - Post runtime resume processing
+ * @q: the queue of the device
+ * @err: return value of the device's runtime_resume function
+ *
+ * Description:
+ * Update the queue's runtime status according to the return value of the
+ * device's runtime_resume function. If it is successfully resumed, process
+ * the requests that are queued into the device's queue when it is resuming
+ * and then mark last busy and initiate autosuspend for it.
+ *
+ * This function should be called near the end of the device's
+ * runtime_resume callback.
+ */
+void blk_post_runtime_resume(struct request_queue *q, int err)
+{
+ if (!q->dev)
+ return;
+
+ spin_lock_irq(q->queue_lock);
+ if (!err) {
+ q->rpm_status = RPM_ACTIVE;
+ __blk_run_queue(q);
+ pm_runtime_mark_last_busy(q->dev);
+ pm_request_autosuspend(q->dev);
+ } else {
+ q->rpm_status = RPM_SUSPENDED;
+ }
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL(blk_post_runtime_resume);
+
+/**
+ * blk_set_runtime_active - Force runtime status of the queue to be active
+ * @q: the queue of the device
+ *
+ * If the device is left runtime suspended during system suspend the resume
+ * hook typically resumes the device and corrects runtime status
+ * accordingly. However, that does not affect the queue runtime PM status
+ * which is still "suspended". This prevents processing requests from the
+ * queue.
+ *
+ * This function can be used in driver's resume hook to correct queue
+ * runtime PM status and re-enable peeking requests from the queue. It
+ * should be called before first request is added to the queue.
+ */
+void blk_set_runtime_active(struct request_queue *q)
+{
+ spin_lock_irq(q->queue_lock);
+ q->rpm_status = RPM_ACTIVE;
+ pm_runtime_mark_last_busy(q->dev);
+ pm_request_autosuspend(q->dev);
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL(blk_set_runtime_active);
+#endif
+
+int __init blk_dev_init(void)
+{
+ BUILD_BUG_ON(REQ_OP_LAST >= (1 << REQ_OP_BITS));
+ BUILD_BUG_ON(REQ_OP_BITS + REQ_FLAG_BITS > 8 *
+ FIELD_SIZEOF(struct request, cmd_flags));
+ BUILD_BUG_ON(REQ_OP_BITS + REQ_FLAG_BITS > 8 *
+ FIELD_SIZEOF(struct bio, bi_opf));
+
+ /* used for unplugging and affects IO latency/throughput - HIGHPRI */
+ kblockd_workqueue = alloc_workqueue("kblockd",
+ WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
+ if (!kblockd_workqueue)
+ panic("Failed to create kblockd\n");
+
+ request_cachep = kmem_cache_create("blkdev_requests",
+ sizeof(struct request), 0, SLAB_PANIC, NULL);
+
+ blk_requestq_cachep = kmem_cache_create("request_queue",
+ sizeof(struct request_queue), 0, SLAB_PANIC, NULL);
+
+#ifdef CONFIG_DEBUG_FS
+ blk_debugfs_root = debugfs_create_dir("block", NULL);
+#endif
+
+ return 0;
+}
diff --git a/src/kernel/linux/v4.14/block/blk-exec.c b/src/kernel/linux/v4.14/block/blk-exec.c
new file mode 100644
index 0000000..5c0f3dc
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-exec.c
@@ -0,0 +1,110 @@
+/*
+ * Functions related to setting various queue properties from drivers
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/sched/sysctl.h>
+
+#include "blk.h"
+#include "blk-mq-sched.h"
+
+/**
+ * blk_end_sync_rq - executes a completion event on a request
+ * @rq: request to complete
+ * @error: end I/O status of the request
+ */
+static void blk_end_sync_rq(struct request *rq, blk_status_t error)
+{
+ struct completion *waiting = rq->end_io_data;
+
+ rq->end_io_data = NULL;
+
+ /*
+ * complete last, if this is a stack request the process (and thus
+ * the rq pointer) could be invalid right after this complete()
+ */
+ complete(waiting);
+}
+
+/**
+ * blk_execute_rq_nowait - insert a request into queue for execution
+ * @q: queue to insert the request in
+ * @bd_disk: matching gendisk
+ * @rq: request to insert
+ * @at_head: insert request at head or tail of queue
+ * @done: I/O completion handler
+ *
+ * Description:
+ * Insert a fully prepared request at the back of the I/O scheduler queue
+ * for execution. Don't wait for completion.
+ *
+ * Note:
+ * This function will invoke @done directly if the queue is dead.
+ */
+void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
+ struct request *rq, int at_head,
+ rq_end_io_fn *done)
+{
+ int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
+
+ WARN_ON(irqs_disabled());
+ WARN_ON(!blk_rq_is_passthrough(rq));
+
+ rq->rq_disk = bd_disk;
+ rq->end_io = done;
+
+ /*
+ * don't check dying flag for MQ because the request won't
+ * be reused after dying flag is set
+ */
+ if (q->mq_ops) {
+ blk_mq_sched_insert_request(rq, at_head, true, false, false);
+ return;
+ }
+
+ spin_lock_irq(q->queue_lock);
+
+ if (unlikely(blk_queue_dying(q))) {
+ rq->rq_flags |= RQF_QUIET;
+ __blk_end_request_all(rq, BLK_STS_IOERR);
+ spin_unlock_irq(q->queue_lock);
+ return;
+ }
+
+ __elv_add_request(q, rq, where);
+ __blk_run_queue(q);
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
+
+/**
+ * blk_execute_rq - insert a request into queue for execution
+ * @q: queue to insert the request in
+ * @bd_disk: matching gendisk
+ * @rq: request to insert
+ * @at_head: insert request at head or tail of queue
+ *
+ * Description:
+ * Insert a fully prepared request at the back of the I/O scheduler queue
+ * for execution and wait for completion.
+ */
+void blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
+ struct request *rq, int at_head)
+{
+ DECLARE_COMPLETION_ONSTACK(wait);
+ unsigned long hang_check;
+
+ rq->end_io_data = &wait;
+ blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
+
+ /* Prevent hang_check timer from firing at us during very long I/O */
+ hang_check = sysctl_hung_task_timeout_secs;
+ if (hang_check)
+ while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2)));
+ else
+ wait_for_completion_io(&wait);
+}
+EXPORT_SYMBOL(blk_execute_rq);
diff --git a/src/kernel/linux/v4.14/block/blk-flush.c b/src/kernel/linux/v4.14/block/blk-flush.c
new file mode 100644
index 0000000..6603352
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-flush.c
@@ -0,0 +1,584 @@
+/*
+ * Functions to sequence PREFLUSH and FUA writes.
+ *
+ * Copyright (C) 2011 Max Planck Institute for Gravitational Physics
+ * Copyright (C) 2011 Tejun Heo <tj@kernel.org>
+ *
+ * This file is released under the GPLv2.
+ *
+ * REQ_{PREFLUSH|FUA} requests are decomposed to sequences consisted of three
+ * optional steps - PREFLUSH, DATA and POSTFLUSH - according to the request
+ * properties and hardware capability.
+ *
+ * If a request doesn't have data, only REQ_PREFLUSH makes sense, which
+ * indicates a simple flush request. If there is data, REQ_PREFLUSH indicates
+ * that the device cache should be flushed before the data is executed, and
+ * REQ_FUA means that the data must be on non-volatile media on request
+ * completion.
+ *
+ * If the device doesn't have writeback cache, PREFLUSH and FUA don't make any
+ * difference. The requests are either completed immediately if there's no data
+ * or executed as normal requests otherwise.
+ *
+ * If the device has writeback cache and supports FUA, REQ_PREFLUSH is
+ * translated to PREFLUSH but REQ_FUA is passed down directly with DATA.
+ *
+ * If the device has writeback cache and doesn't support FUA, REQ_PREFLUSH
+ * is translated to PREFLUSH and REQ_FUA to POSTFLUSH.
+ *
+ * The actual execution of flush is double buffered. Whenever a request
+ * needs to execute PRE or POSTFLUSH, it queues at
+ * fq->flush_queue[fq->flush_pending_idx]. Once certain criteria are met, a
+ * REQ_OP_FLUSH is issued and the pending_idx is toggled. When the flush
+ * completes, all the requests which were pending are proceeded to the next
+ * step. This allows arbitrary merging of different types of PREFLUSH/FUA
+ * requests.
+ *
+ * Currently, the following conditions are used to determine when to issue
+ * flush.
+ *
+ * C1. At any given time, only one flush shall be in progress. This makes
+ * double buffering sufficient.
+ *
+ * C2. Flush is deferred if any request is executing DATA of its sequence.
+ * This avoids issuing separate POSTFLUSHes for requests which shared
+ * PREFLUSH.
+ *
+ * C3. The second condition is ignored if there is a request which has
+ * waited longer than FLUSH_PENDING_TIMEOUT. This is to avoid
+ * starvation in the unlikely case where there are continuous stream of
+ * FUA (without PREFLUSH) requests.
+ *
+ * For devices which support FUA, it isn't clear whether C2 (and thus C3)
+ * is beneficial.
+ *
+ * Note that a sequenced PREFLUSH/FUA request with DATA is completed twice.
+ * Once while executing DATA and again after the whole sequence is
+ * complete. The first completion updates the contained bio but doesn't
+ * finish it so that the bio submitter is notified only after the whole
+ * sequence is complete. This is implemented by testing RQF_FLUSH_SEQ in
+ * req_bio_endio().
+ *
+ * The above peculiarity requires that each PREFLUSH/FUA request has only one
+ * bio attached to it, which is guaranteed as they aren't allowed to be
+ * merged in the usual way.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/gfp.h>
+#include <linux/blk-mq.h>
+
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-tag.h"
+#include "blk-mq-sched.h"
+
+/* PREFLUSH/FUA sequences */
+enum {
+ REQ_FSEQ_PREFLUSH = (1 << 0), /* pre-flushing in progress */
+ REQ_FSEQ_DATA = (1 << 1), /* data write in progress */
+ REQ_FSEQ_POSTFLUSH = (1 << 2), /* post-flushing in progress */
+ REQ_FSEQ_DONE = (1 << 3),
+
+ REQ_FSEQ_ACTIONS = REQ_FSEQ_PREFLUSH | REQ_FSEQ_DATA |
+ REQ_FSEQ_POSTFLUSH,
+
+ /*
+ * If flush has been pending longer than the following timeout,
+ * it's issued even if flush_data requests are still in flight.
+ */
+ FLUSH_PENDING_TIMEOUT = 5 * HZ,
+};
+
+static bool blk_kick_flush(struct request_queue *q,
+ struct blk_flush_queue *fq);
+
+static unsigned int blk_flush_policy(unsigned long fflags, struct request *rq)
+{
+ unsigned int policy = 0;
+
+ if (blk_rq_sectors(rq))
+ policy |= REQ_FSEQ_DATA;
+
+ if (fflags & (1UL << QUEUE_FLAG_WC)) {
+ if (rq->cmd_flags & REQ_PREFLUSH)
+ policy |= REQ_FSEQ_PREFLUSH;
+ if (!(fflags & (1UL << QUEUE_FLAG_FUA)) &&
+ (rq->cmd_flags & REQ_FUA))
+ policy |= REQ_FSEQ_POSTFLUSH;
+ }
+ return policy;
+}
+
+static unsigned int blk_flush_cur_seq(struct request *rq)
+{
+ return 1 << ffz(rq->flush.seq);
+}
+
+static void blk_flush_restore_request(struct request *rq)
+{
+ /*
+ * After flush data completion, @rq->bio is %NULL but we need to
+ * complete the bio again. @rq->biotail is guaranteed to equal the
+ * original @rq->bio. Restore it.
+ */
+ rq->bio = rq->biotail;
+
+ /* make @rq a normal request */
+ rq->rq_flags &= ~RQF_FLUSH_SEQ;
+ rq->end_io = rq->flush.saved_end_io;
+}
+
+static bool blk_flush_queue_rq(struct request *rq, bool add_front)
+{
+ if (rq->q->mq_ops) {
+ blk_mq_add_to_requeue_list(rq, add_front, true);
+ return false;
+ } else {
+ if (add_front)
+ list_add(&rq->queuelist, &rq->q->queue_head);
+ else
+ list_add_tail(&rq->queuelist, &rq->q->queue_head);
+ return true;
+ }
+}
+
+/**
+ * blk_flush_complete_seq - complete flush sequence
+ * @rq: PREFLUSH/FUA request being sequenced
+ * @fq: flush queue
+ * @seq: sequences to complete (mask of %REQ_FSEQ_*, can be zero)
+ * @error: whether an error occurred
+ *
+ * @rq just completed @seq part of its flush sequence, record the
+ * completion and trigger the next step.
+ *
+ * CONTEXT:
+ * spin_lock_irq(q->queue_lock or fq->mq_flush_lock)
+ *
+ * RETURNS:
+ * %true if requests were added to the dispatch queue, %false otherwise.
+ */
+static bool blk_flush_complete_seq(struct request *rq,
+ struct blk_flush_queue *fq,
+ unsigned int seq, blk_status_t error)
+{
+ struct request_queue *q = rq->q;
+ struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx];
+ bool queued = false, kicked;
+
+ BUG_ON(rq->flush.seq & seq);
+ rq->flush.seq |= seq;
+
+ if (likely(!error))
+ seq = blk_flush_cur_seq(rq);
+ else
+ seq = REQ_FSEQ_DONE;
+
+ switch (seq) {
+ case REQ_FSEQ_PREFLUSH:
+ case REQ_FSEQ_POSTFLUSH:
+ /* queue for flush */
+ if (list_empty(pending))
+ fq->flush_pending_since = jiffies;
+ list_move_tail(&rq->flush.list, pending);
+ break;
+
+ case REQ_FSEQ_DATA:
+ list_move_tail(&rq->flush.list, &fq->flush_data_in_flight);
+ queued = blk_flush_queue_rq(rq, true);
+ break;
+
+ case REQ_FSEQ_DONE:
+ /*
+ * @rq was previously adjusted by blk_flush_issue() for
+ * flush sequencing and may already have gone through the
+ * flush data request completion path. Restore @rq for
+ * normal completion and end it.
+ */
+ BUG_ON(!list_empty(&rq->queuelist));
+ list_del_init(&rq->flush.list);
+ blk_flush_restore_request(rq);
+ if (q->mq_ops)
+ blk_mq_end_request(rq, error);
+ else
+ __blk_end_request_all(rq, error);
+ break;
+
+ default:
+ BUG();
+ }
+
+ kicked = blk_kick_flush(q, fq);
+ return kicked | queued;
+}
+
+static void flush_end_io(struct request *flush_rq, blk_status_t error)
+{
+ struct request_queue *q = flush_rq->q;
+ struct list_head *running;
+ bool queued = false;
+ struct request *rq, *n;
+ unsigned long flags = 0;
+ struct blk_flush_queue *fq = blk_get_flush_queue(q, flush_rq->mq_ctx);
+
+ if (q->mq_ops) {
+ struct blk_mq_hw_ctx *hctx;
+
+ /* release the tag's ownership to the req cloned from */
+ spin_lock_irqsave(&fq->mq_flush_lock, flags);
+ hctx = blk_mq_map_queue(q, flush_rq->mq_ctx->cpu);
+ blk_mq_tag_set_rq(hctx, flush_rq->tag, fq->orig_rq);
+ flush_rq->tag = -1;
+ }
+
+ running = &fq->flush_queue[fq->flush_running_idx];
+ BUG_ON(fq->flush_pending_idx == fq->flush_running_idx);
+
+ /* account completion of the flush request */
+ fq->flush_running_idx ^= 1;
+
+ if (!q->mq_ops)
+ elv_completed_request(q, flush_rq);
+
+ /* and push the waiting requests to the next stage */
+ list_for_each_entry_safe(rq, n, running, flush.list) {
+ unsigned int seq = blk_flush_cur_seq(rq);
+
+ BUG_ON(seq != REQ_FSEQ_PREFLUSH && seq != REQ_FSEQ_POSTFLUSH);
+ queued |= blk_flush_complete_seq(rq, fq, seq, error);
+ }
+
+ /*
+ * Kick the queue to avoid stall for two cases:
+ * 1. Moving a request silently to empty queue_head may stall the
+ * queue.
+ * 2. When flush request is running in non-queueable queue, the
+ * queue is hold. Restart the queue after flush request is finished
+ * to avoid stall.
+ * This function is called from request completion path and calling
+ * directly into request_fn may confuse the driver. Always use
+ * kblockd.
+ */
+ if (queued || fq->flush_queue_delayed) {
+ WARN_ON(q->mq_ops);
+ blk_run_queue_async(q);
+ }
+ fq->flush_queue_delayed = 0;
+ if (q->mq_ops)
+ spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
+}
+
+/**
+ * blk_kick_flush - consider issuing flush request
+ * @q: request_queue being kicked
+ * @fq: flush queue
+ *
+ * Flush related states of @q have changed, consider issuing flush request.
+ * Please read the comment at the top of this file for more info.
+ *
+ * CONTEXT:
+ * spin_lock_irq(q->queue_lock or fq->mq_flush_lock)
+ *
+ * RETURNS:
+ * %true if flush was issued, %false otherwise.
+ */
+static bool blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq)
+{
+ struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx];
+ struct request *first_rq =
+ list_first_entry(pending, struct request, flush.list);
+ struct request *flush_rq = fq->flush_rq;
+
+ /* C1 described at the top of this file */
+ if (fq->flush_pending_idx != fq->flush_running_idx || list_empty(pending))
+ return false;
+
+ /* C2 and C3
+ *
+ * For blk-mq + scheduling, we can risk having all driver tags
+ * assigned to empty flushes, and we deadlock if we are expecting
+ * other requests to make progress. Don't defer for that case.
+ */
+ if (!list_empty(&fq->flush_data_in_flight) &&
+ !(q->mq_ops && q->elevator) &&
+ time_before(jiffies,
+ fq->flush_pending_since + FLUSH_PENDING_TIMEOUT))
+ return false;
+
+ /*
+ * Issue flush and toggle pending_idx. This makes pending_idx
+ * different from running_idx, which means flush is in flight.
+ */
+ fq->flush_pending_idx ^= 1;
+
+ blk_rq_init(q, flush_rq);
+
+ /*
+ * Borrow tag from the first request since they can't
+ * be in flight at the same time. And acquire the tag's
+ * ownership for flush req.
+ */
+ if (q->mq_ops) {
+ struct blk_mq_hw_ctx *hctx;
+
+ flush_rq->mq_ctx = first_rq->mq_ctx;
+ flush_rq->tag = first_rq->tag;
+ fq->orig_rq = first_rq;
+
+ hctx = blk_mq_map_queue(q, first_rq->mq_ctx->cpu);
+ blk_mq_tag_set_rq(hctx, first_rq->tag, flush_rq);
+ }
+
+ flush_rq->cmd_flags = REQ_OP_FLUSH | REQ_PREFLUSH;
+ flush_rq->rq_flags |= RQF_FLUSH_SEQ;
+ flush_rq->rq_disk = first_rq->rq_disk;
+ flush_rq->end_io = flush_end_io;
+
+ return blk_flush_queue_rq(flush_rq, false);
+}
+
+static void flush_data_end_io(struct request *rq, blk_status_t error)
+{
+ struct request_queue *q = rq->q;
+ struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
+
+ lockdep_assert_held(q->queue_lock);
+
+ /*
+ * Updating q->in_flight[] here for making this tag usable
+ * early. Because in blk_queue_start_tag(),
+ * q->in_flight[BLK_RW_ASYNC] is used to limit async I/O and
+ * reserve tags for sync I/O.
+ *
+ * More importantly this way can avoid the following I/O
+ * deadlock:
+ *
+ * - suppose there are 40 fua requests comming to flush queue
+ * and queue depth is 31
+ * - 30 rqs are scheduled then blk_queue_start_tag() can't alloc
+ * tag for async I/O any more
+ * - all the 30 rqs are completed before FLUSH_PENDING_TIMEOUT
+ * and flush_data_end_io() is called
+ * - the other rqs still can't go ahead if not updating
+ * q->in_flight[BLK_RW_ASYNC] here, meantime these rqs
+ * are held in flush data queue and make no progress of
+ * handling post flush rq
+ * - only after the post flush rq is handled, all these rqs
+ * can be completed
+ */
+
+ elv_completed_request(q, rq);
+
+ /* for avoiding double accounting */
+ rq->rq_flags &= ~RQF_STARTED;
+
+ /*
+ * After populating an empty queue, kick it to avoid stall. Read
+ * the comment in flush_end_io().
+ */
+ if (blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error))
+ blk_run_queue_async(q);
+}
+
+static void mq_flush_data_end_io(struct request *rq, blk_status_t error)
+{
+ struct request_queue *q = rq->q;
+ struct blk_mq_hw_ctx *hctx;
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+ unsigned long flags;
+ struct blk_flush_queue *fq = blk_get_flush_queue(q, ctx);
+
+ hctx = blk_mq_map_queue(q, ctx->cpu);
+
+ /*
+ * After populating an empty queue, kick it to avoid stall. Read
+ * the comment in flush_end_io().
+ */
+ spin_lock_irqsave(&fq->mq_flush_lock, flags);
+ blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error);
+ spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
+
+ blk_mq_sched_restart(hctx);
+}
+
+/**
+ * blk_insert_flush - insert a new PREFLUSH/FUA request
+ * @rq: request to insert
+ *
+ * To be called from __elv_add_request() for %ELEVATOR_INSERT_FLUSH insertions.
+ * or __blk_mq_run_hw_queue() to dispatch request.
+ * @rq is being submitted. Analyze what needs to be done and put it on the
+ * right queue.
+ */
+void blk_insert_flush(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ unsigned long fflags = q->queue_flags; /* may change, cache */
+ unsigned int policy = blk_flush_policy(fflags, rq);
+ struct blk_flush_queue *fq = blk_get_flush_queue(q, rq->mq_ctx);
+
+ if (!q->mq_ops)
+ lockdep_assert_held(q->queue_lock);
+
+ /*
+ * @policy now records what operations need to be done. Adjust
+ * REQ_PREFLUSH and FUA for the driver.
+ */
+ rq->cmd_flags &= ~REQ_PREFLUSH;
+ if (!(fflags & (1UL << QUEUE_FLAG_FUA)))
+ rq->cmd_flags &= ~REQ_FUA;
+
+ /*
+ * REQ_PREFLUSH|REQ_FUA implies REQ_SYNC, so if we clear any
+ * of those flags, we have to set REQ_SYNC to avoid skewing
+ * the request accounting.
+ */
+ rq->cmd_flags |= REQ_SYNC;
+
+ /*
+ * An empty flush handed down from a stacking driver may
+ * translate into nothing if the underlying device does not
+ * advertise a write-back cache. In this case, simply
+ * complete the request.
+ */
+ if (!policy) {
+ if (q->mq_ops)
+ blk_mq_end_request(rq, 0);
+ else
+ __blk_end_request(rq, 0, 0);
+ return;
+ }
+
+ BUG_ON(rq->bio != rq->biotail); /*assumes zero or single bio rq */
+
+ /*
+ * If there's data but flush is not necessary, the request can be
+ * processed directly without going through flush machinery. Queue
+ * for normal execution.
+ */
+ if ((policy & REQ_FSEQ_DATA) &&
+ !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) {
+ if (q->mq_ops)
+ blk_mq_sched_insert_request(rq, false, true, false, false);
+ else
+ list_add_tail(&rq->queuelist, &q->queue_head);
+ return;
+ }
+
+ /*
+ * @rq should go through flush machinery. Mark it part of flush
+ * sequence and submit for further processing.
+ */
+ memset(&rq->flush, 0, sizeof(rq->flush));
+ INIT_LIST_HEAD(&rq->flush.list);
+ rq->rq_flags |= RQF_FLUSH_SEQ;
+ rq->flush.saved_end_io = rq->end_io; /* Usually NULL */
+ if (q->mq_ops) {
+ rq->end_io = mq_flush_data_end_io;
+
+ spin_lock_irq(&fq->mq_flush_lock);
+ blk_flush_complete_seq(rq, fq, REQ_FSEQ_ACTIONS & ~policy, 0);
+ spin_unlock_irq(&fq->mq_flush_lock);
+ return;
+ }
+ rq->end_io = flush_data_end_io;
+
+ blk_flush_complete_seq(rq, fq, REQ_FSEQ_ACTIONS & ~policy, 0);
+}
+
+/**
+ * blkdev_issue_flush - queue a flush
+ * @bdev: blockdev to issue flush for
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @error_sector: error sector
+ *
+ * Description:
+ * Issue a flush for the block device in question. Caller can supply
+ * room for storing the error offset in case of a flush error, if they
+ * wish to.
+ */
+int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
+ sector_t *error_sector)
+{
+ struct request_queue *q;
+ struct bio *bio;
+ int ret = 0;
+
+ if (bdev->bd_disk == NULL)
+ return -ENXIO;
+
+ q = bdev_get_queue(bdev);
+ if (!q)
+ return -ENXIO;
+
+ /*
+ * some block devices may not have their queue correctly set up here
+ * (e.g. loop device without a backing file) and so issuing a flush
+ * here will panic. Ensure there is a request function before issuing
+ * the flush.
+ */
+ if (!q->make_request_fn)
+ return -ENXIO;
+
+ bio = bio_alloc(gfp_mask, 0);
+ bio_set_dev(bio, bdev);
+ bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
+
+ ret = submit_bio_wait(bio);
+
+ /*
+ * The driver must store the error location in ->bi_sector, if
+ * it supports it. For non-stacked drivers, this should be
+ * copied from blk_rq_pos(rq).
+ */
+ if (error_sector)
+ *error_sector = bio->bi_iter.bi_sector;
+
+ bio_put(bio);
+ return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_flush);
+
+struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
+ int node, int cmd_size)
+{
+ struct blk_flush_queue *fq;
+ int rq_sz = sizeof(struct request);
+
+ fq = kzalloc_node(sizeof(*fq), GFP_KERNEL, node);
+ if (!fq)
+ goto fail;
+
+ if (q->mq_ops)
+ spin_lock_init(&fq->mq_flush_lock);
+
+ rq_sz = round_up(rq_sz + cmd_size, cache_line_size());
+ fq->flush_rq = kzalloc_node(rq_sz, GFP_KERNEL, node);
+ if (!fq->flush_rq)
+ goto fail_rq;
+
+ INIT_LIST_HEAD(&fq->flush_queue[0]);
+ INIT_LIST_HEAD(&fq->flush_queue[1]);
+ INIT_LIST_HEAD(&fq->flush_data_in_flight);
+
+ return fq;
+
+ fail_rq:
+ kfree(fq);
+ fail:
+ return NULL;
+}
+
+void blk_free_flush_queue(struct blk_flush_queue *fq)
+{
+ /* bio based request queue hasn't flush queue */
+ if (!fq)
+ return;
+
+ kfree(fq->flush_rq);
+ kfree(fq);
+}
diff --git a/src/kernel/linux/v4.14/block/blk-integrity.c b/src/kernel/linux/v4.14/block/blk-integrity.c
new file mode 100644
index 0000000..feb3057
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-integrity.c
@@ -0,0 +1,453 @@
+/*
+ * blk-integrity.c - Block layer data integrity extensions
+ *
+ * Copyright (C) 2007, 2008 Oracle Corporation
+ * Written by: Martin K. Petersen <martin.petersen@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ */
+
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/mempool.h>
+#include <linux/bio.h>
+#include <linux/scatterlist.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+
+#include "blk.h"
+
+/**
+ * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
+ * @q: request queue
+ * @bio: bio with integrity metadata attached
+ *
+ * Description: Returns the number of elements required in a
+ * scatterlist corresponding to the integrity metadata in a bio.
+ */
+int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
+{
+ struct bio_vec iv, ivprv = { NULL };
+ unsigned int segments = 0;
+ unsigned int seg_size = 0;
+ struct bvec_iter iter;
+ int prev = 0;
+
+ bio_for_each_integrity_vec(iv, bio, iter) {
+
+ if (prev) {
+ if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
+ goto new_segment;
+
+ if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
+ goto new_segment;
+
+ if (seg_size + iv.bv_len > queue_max_segment_size(q))
+ goto new_segment;
+
+ seg_size += iv.bv_len;
+ } else {
+new_segment:
+ segments++;
+ seg_size = iv.bv_len;
+ }
+
+ prev = 1;
+ ivprv = iv;
+ }
+
+ return segments;
+}
+EXPORT_SYMBOL(blk_rq_count_integrity_sg);
+
+/**
+ * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
+ * @q: request queue
+ * @bio: bio with integrity metadata attached
+ * @sglist: target scatterlist
+ *
+ * Description: Map the integrity vectors in request into a
+ * scatterlist. The scatterlist must be big enough to hold all
+ * elements. I.e. sized using blk_rq_count_integrity_sg().
+ */
+int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
+ struct scatterlist *sglist)
+{
+ struct bio_vec iv, ivprv = { NULL };
+ struct scatterlist *sg = NULL;
+ unsigned int segments = 0;
+ struct bvec_iter iter;
+ int prev = 0;
+
+ bio_for_each_integrity_vec(iv, bio, iter) {
+
+ if (prev) {
+ if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
+ goto new_segment;
+
+ if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
+ goto new_segment;
+
+ if (sg->length + iv.bv_len > queue_max_segment_size(q))
+ goto new_segment;
+
+ sg->length += iv.bv_len;
+ } else {
+new_segment:
+ if (!sg)
+ sg = sglist;
+ else {
+ sg_unmark_end(sg);
+ sg = sg_next(sg);
+ }
+
+ sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
+ segments++;
+ }
+
+ prev = 1;
+ ivprv = iv;
+ }
+
+ if (sg)
+ sg_mark_end(sg);
+
+ return segments;
+}
+EXPORT_SYMBOL(blk_rq_map_integrity_sg);
+
+/**
+ * blk_integrity_compare - Compare integrity profile of two disks
+ * @gd1: Disk to compare
+ * @gd2: Disk to compare
+ *
+ * Description: Meta-devices like DM and MD need to verify that all
+ * sub-devices use the same integrity format before advertising to
+ * upper layers that they can send/receive integrity metadata. This
+ * function can be used to check whether two gendisk devices have
+ * compatible integrity formats.
+ */
+int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
+{
+ struct blk_integrity *b1 = &gd1->queue->integrity;
+ struct blk_integrity *b2 = &gd2->queue->integrity;
+
+ if (!b1->profile && !b2->profile)
+ return 0;
+
+ if (!b1->profile || !b2->profile)
+ return -1;
+
+ if (b1->interval_exp != b2->interval_exp) {
+ pr_err("%s: %s/%s protection interval %u != %u\n",
+ __func__, gd1->disk_name, gd2->disk_name,
+ 1 << b1->interval_exp, 1 << b2->interval_exp);
+ return -1;
+ }
+
+ if (b1->tuple_size != b2->tuple_size) {
+ pr_err("%s: %s/%s tuple sz %u != %u\n", __func__,
+ gd1->disk_name, gd2->disk_name,
+ b1->tuple_size, b2->tuple_size);
+ return -1;
+ }
+
+ if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
+ pr_err("%s: %s/%s tag sz %u != %u\n", __func__,
+ gd1->disk_name, gd2->disk_name,
+ b1->tag_size, b2->tag_size);
+ return -1;
+ }
+
+ if (b1->profile != b2->profile) {
+ pr_err("%s: %s/%s type %s != %s\n", __func__,
+ gd1->disk_name, gd2->disk_name,
+ b1->profile->name, b2->profile->name);
+ return -1;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(blk_integrity_compare);
+
+bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
+ struct request *next)
+{
+ if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
+ return true;
+
+ if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
+ return false;
+
+ if (bio_integrity(req->bio)->bip_flags !=
+ bio_integrity(next->bio)->bip_flags)
+ return false;
+
+ if (req->nr_integrity_segments + next->nr_integrity_segments >
+ q->limits.max_integrity_segments)
+ return false;
+
+ if (integrity_req_gap_back_merge(req, next->bio))
+ return false;
+
+ return true;
+}
+EXPORT_SYMBOL(blk_integrity_merge_rq);
+
+bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
+ struct bio *bio)
+{
+ int nr_integrity_segs;
+ struct bio *next = bio->bi_next;
+
+ if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
+ return true;
+
+ if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
+ return false;
+
+ if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
+ return false;
+
+ bio->bi_next = NULL;
+ nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
+ bio->bi_next = next;
+
+ if (req->nr_integrity_segments + nr_integrity_segs >
+ q->limits.max_integrity_segments)
+ return false;
+
+ req->nr_integrity_segments += nr_integrity_segs;
+
+ return true;
+}
+EXPORT_SYMBOL(blk_integrity_merge_bio);
+
+struct integrity_sysfs_entry {
+ struct attribute attr;
+ ssize_t (*show)(struct blk_integrity *, char *);
+ ssize_t (*store)(struct blk_integrity *, const char *, size_t);
+};
+
+static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
+ char *page)
+{
+ struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
+ struct blk_integrity *bi = &disk->queue->integrity;
+ struct integrity_sysfs_entry *entry =
+ container_of(attr, struct integrity_sysfs_entry, attr);
+
+ return entry->show(bi, page);
+}
+
+static ssize_t integrity_attr_store(struct kobject *kobj,
+ struct attribute *attr, const char *page,
+ size_t count)
+{
+ struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
+ struct blk_integrity *bi = &disk->queue->integrity;
+ struct integrity_sysfs_entry *entry =
+ container_of(attr, struct integrity_sysfs_entry, attr);
+ ssize_t ret = 0;
+
+ if (entry->store)
+ ret = entry->store(bi, page, count);
+
+ return ret;
+}
+
+static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
+{
+ if (bi->profile && bi->profile->name)
+ return sprintf(page, "%s\n", bi->profile->name);
+ else
+ return sprintf(page, "none\n");
+}
+
+static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
+{
+ return sprintf(page, "%u\n", bi->tag_size);
+}
+
+static ssize_t integrity_interval_show(struct blk_integrity *bi, char *page)
+{
+ return sprintf(page, "%u\n",
+ bi->interval_exp ? 1 << bi->interval_exp : 0);
+}
+
+static ssize_t integrity_verify_store(struct blk_integrity *bi,
+ const char *page, size_t count)
+{
+ char *p = (char *) page;
+ unsigned long val = simple_strtoul(p, &p, 10);
+
+ if (val)
+ bi->flags |= BLK_INTEGRITY_VERIFY;
+ else
+ bi->flags &= ~BLK_INTEGRITY_VERIFY;
+
+ return count;
+}
+
+static ssize_t integrity_verify_show(struct blk_integrity *bi, char *page)
+{
+ return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
+}
+
+static ssize_t integrity_generate_store(struct blk_integrity *bi,
+ const char *page, size_t count)
+{
+ char *p = (char *) page;
+ unsigned long val = simple_strtoul(p, &p, 10);
+
+ if (val)
+ bi->flags |= BLK_INTEGRITY_GENERATE;
+ else
+ bi->flags &= ~BLK_INTEGRITY_GENERATE;
+
+ return count;
+}
+
+static ssize_t integrity_generate_show(struct blk_integrity *bi, char *page)
+{
+ return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
+}
+
+static ssize_t integrity_device_show(struct blk_integrity *bi, char *page)
+{
+ return sprintf(page, "%u\n",
+ (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) != 0);
+}
+
+static struct integrity_sysfs_entry integrity_format_entry = {
+ .attr = { .name = "format", .mode = S_IRUGO },
+ .show = integrity_format_show,
+};
+
+static struct integrity_sysfs_entry integrity_tag_size_entry = {
+ .attr = { .name = "tag_size", .mode = S_IRUGO },
+ .show = integrity_tag_size_show,
+};
+
+static struct integrity_sysfs_entry integrity_interval_entry = {
+ .attr = { .name = "protection_interval_bytes", .mode = S_IRUGO },
+ .show = integrity_interval_show,
+};
+
+static struct integrity_sysfs_entry integrity_verify_entry = {
+ .attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
+ .show = integrity_verify_show,
+ .store = integrity_verify_store,
+};
+
+static struct integrity_sysfs_entry integrity_generate_entry = {
+ .attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
+ .show = integrity_generate_show,
+ .store = integrity_generate_store,
+};
+
+static struct integrity_sysfs_entry integrity_device_entry = {
+ .attr = { .name = "device_is_integrity_capable", .mode = S_IRUGO },
+ .show = integrity_device_show,
+};
+
+static struct attribute *integrity_attrs[] = {
+ &integrity_format_entry.attr,
+ &integrity_tag_size_entry.attr,
+ &integrity_interval_entry.attr,
+ &integrity_verify_entry.attr,
+ &integrity_generate_entry.attr,
+ &integrity_device_entry.attr,
+ NULL,
+};
+
+static const struct sysfs_ops integrity_ops = {
+ .show = &integrity_attr_show,
+ .store = &integrity_attr_store,
+};
+
+static struct kobj_type integrity_ktype = {
+ .default_attrs = integrity_attrs,
+ .sysfs_ops = &integrity_ops,
+};
+
+static blk_status_t blk_integrity_nop_fn(struct blk_integrity_iter *iter)
+{
+ return BLK_STS_OK;
+}
+
+static const struct blk_integrity_profile nop_profile = {
+ .name = "nop",
+ .generate_fn = blk_integrity_nop_fn,
+ .verify_fn = blk_integrity_nop_fn,
+};
+
+/**
+ * blk_integrity_register - Register a gendisk as being integrity-capable
+ * @disk: struct gendisk pointer to make integrity-aware
+ * @template: block integrity profile to register
+ *
+ * Description: When a device needs to advertise itself as being able to
+ * send/receive integrity metadata it must use this function to register
+ * the capability with the block layer. The template is a blk_integrity
+ * struct with values appropriate for the underlying hardware. See
+ * Documentation/block/data-integrity.txt.
+ */
+void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
+{
+ struct blk_integrity *bi = &disk->queue->integrity;
+
+ bi->flags = BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE |
+ template->flags;
+ bi->interval_exp = template->interval_exp ? :
+ ilog2(queue_logical_block_size(disk->queue));
+ bi->profile = template->profile ? template->profile : &nop_profile;
+ bi->tuple_size = template->tuple_size;
+ bi->tag_size = template->tag_size;
+
+ disk->queue->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
+}
+EXPORT_SYMBOL(blk_integrity_register);
+
+/**
+ * blk_integrity_unregister - Unregister block integrity profile
+ * @disk: disk whose integrity profile to unregister
+ *
+ * Description: This function unregisters the integrity capability from
+ * a block device.
+ */
+void blk_integrity_unregister(struct gendisk *disk)
+{
+ disk->queue->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
+ memset(&disk->queue->integrity, 0, sizeof(struct blk_integrity));
+}
+EXPORT_SYMBOL(blk_integrity_unregister);
+
+void blk_integrity_add(struct gendisk *disk)
+{
+ if (kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,
+ &disk_to_dev(disk)->kobj, "%s", "integrity"))
+ return;
+
+ kobject_uevent(&disk->integrity_kobj, KOBJ_ADD);
+}
+
+void blk_integrity_del(struct gendisk *disk)
+{
+ kobject_uevent(&disk->integrity_kobj, KOBJ_REMOVE);
+ kobject_del(&disk->integrity_kobj);
+ kobject_put(&disk->integrity_kobj);
+}
diff --git a/src/kernel/linux/v4.14/block/blk-ioc.c b/src/kernel/linux/v4.14/block/blk-ioc.c
new file mode 100644
index 0000000..e56a480
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-ioc.c
@@ -0,0 +1,448 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to io context handling
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/sched/task.h>
+
+#include "blk.h"
+
+/*
+ * For io context allocations
+ */
+static struct kmem_cache *iocontext_cachep;
+
+/**
+ * get_io_context - increment reference count to io_context
+ * @ioc: io_context to get
+ *
+ * Increment reference count to @ioc.
+ */
+void get_io_context(struct io_context *ioc)
+{
+ BUG_ON(atomic_long_read(&ioc->refcount) <= 0);
+ atomic_long_inc(&ioc->refcount);
+}
+EXPORT_SYMBOL(get_io_context);
+
+static void icq_free_icq_rcu(struct rcu_head *head)
+{
+ struct io_cq *icq = container_of(head, struct io_cq, __rcu_head);
+
+ kmem_cache_free(icq->__rcu_icq_cache, icq);
+}
+
+/*
+ * Exit an icq. Called with ioc locked for blk-mq, and with both ioc
+ * and queue locked for legacy.
+ */
+static void ioc_exit_icq(struct io_cq *icq)
+{
+ struct elevator_type *et = icq->q->elevator->type;
+
+ if (icq->flags & ICQ_EXITED)
+ return;
+
+ if (et->uses_mq && et->ops.mq.exit_icq)
+ et->ops.mq.exit_icq(icq);
+ else if (!et->uses_mq && et->ops.sq.elevator_exit_icq_fn)
+ et->ops.sq.elevator_exit_icq_fn(icq);
+
+ icq->flags |= ICQ_EXITED;
+}
+
+/*
+ * Release an icq. Called with ioc locked for blk-mq, and with both ioc
+ * and queue locked for legacy.
+ */
+static void ioc_destroy_icq(struct io_cq *icq)
+{
+ struct io_context *ioc = icq->ioc;
+ struct request_queue *q = icq->q;
+ struct elevator_type *et = q->elevator->type;
+
+ lockdep_assert_held(&ioc->lock);
+
+ radix_tree_delete(&ioc->icq_tree, icq->q->id);
+ hlist_del_init(&icq->ioc_node);
+ list_del_init(&icq->q_node);
+
+ /*
+ * Both setting lookup hint to and clearing it from @icq are done
+ * under queue_lock. If it's not pointing to @icq now, it never
+ * will. Hint assignment itself can race safely.
+ */
+ if (rcu_access_pointer(ioc->icq_hint) == icq)
+ rcu_assign_pointer(ioc->icq_hint, NULL);
+
+ ioc_exit_icq(icq);
+
+ /*
+ * @icq->q might have gone away by the time RCU callback runs
+ * making it impossible to determine icq_cache. Record it in @icq.
+ */
+ icq->__rcu_icq_cache = et->icq_cache;
+ icq->flags |= ICQ_DESTROYED;
+ call_rcu(&icq->__rcu_head, icq_free_icq_rcu);
+}
+
+/*
+ * Slow path for ioc release in put_io_context(). Performs double-lock
+ * dancing to unlink all icq's and then frees ioc.
+ */
+static void ioc_release_fn(struct work_struct *work)
+{
+ struct io_context *ioc = container_of(work, struct io_context,
+ release_work);
+ unsigned long flags;
+
+ /*
+ * Exiting icq may call into put_io_context() through elevator
+ * which will trigger lockdep warning. The ioc's are guaranteed to
+ * be different, use a different locking subclass here. Use
+ * irqsave variant as there's no spin_lock_irq_nested().
+ */
+ spin_lock_irqsave_nested(&ioc->lock, flags, 1);
+
+ while (!hlist_empty(&ioc->icq_list)) {
+ struct io_cq *icq = hlist_entry(ioc->icq_list.first,
+ struct io_cq, ioc_node);
+ struct request_queue *q = icq->q;
+
+ if (spin_trylock(q->queue_lock)) {
+ ioc_destroy_icq(icq);
+ spin_unlock(q->queue_lock);
+ } else {
+ spin_unlock_irqrestore(&ioc->lock, flags);
+ cpu_relax();
+ spin_lock_irqsave_nested(&ioc->lock, flags, 1);
+ }
+ }
+
+ spin_unlock_irqrestore(&ioc->lock, flags);
+
+ kmem_cache_free(iocontext_cachep, ioc);
+}
+
+/**
+ * put_io_context - put a reference of io_context
+ * @ioc: io_context to put
+ *
+ * Decrement reference count of @ioc and release it if the count reaches
+ * zero.
+ */
+void put_io_context(struct io_context *ioc)
+{
+ unsigned long flags;
+ bool free_ioc = false;
+
+ if (ioc == NULL)
+ return;
+
+ BUG_ON(atomic_long_read(&ioc->refcount) <= 0);
+
+ /*
+ * Releasing ioc requires reverse order double locking and we may
+ * already be holding a queue_lock. Do it asynchronously from wq.
+ */
+ if (atomic_long_dec_and_test(&ioc->refcount)) {
+ spin_lock_irqsave(&ioc->lock, flags);
+ if (!hlist_empty(&ioc->icq_list))
+ queue_work(system_power_efficient_wq,
+ &ioc->release_work);
+ else
+ free_ioc = true;
+ spin_unlock_irqrestore(&ioc->lock, flags);
+ }
+
+ if (free_ioc)
+ kmem_cache_free(iocontext_cachep, ioc);
+}
+EXPORT_SYMBOL(put_io_context);
+
+/**
+ * put_io_context_active - put active reference on ioc
+ * @ioc: ioc of interest
+ *
+ * Undo get_io_context_active(). If active reference reaches zero after
+ * put, @ioc can never issue further IOs and ioscheds are notified.
+ */
+void put_io_context_active(struct io_context *ioc)
+{
+ struct elevator_type *et;
+ unsigned long flags;
+ struct io_cq *icq;
+
+ if (!atomic_dec_and_test(&ioc->active_ref)) {
+ put_io_context(ioc);
+ return;
+ }
+
+ /*
+ * Need ioc lock to walk icq_list and q lock to exit icq. Perform
+ * reverse double locking. Read comment in ioc_release_fn() for
+ * explanation on the nested locking annotation.
+ */
+retry:
+ spin_lock_irqsave_nested(&ioc->lock, flags, 1);
+ hlist_for_each_entry(icq, &ioc->icq_list, ioc_node) {
+ if (icq->flags & ICQ_EXITED)
+ continue;
+
+ et = icq->q->elevator->type;
+ if (et->uses_mq) {
+ ioc_exit_icq(icq);
+ } else {
+ if (spin_trylock(icq->q->queue_lock)) {
+ ioc_exit_icq(icq);
+ spin_unlock(icq->q->queue_lock);
+ } else {
+ spin_unlock_irqrestore(&ioc->lock, flags);
+ cpu_relax();
+ goto retry;
+ }
+ }
+ }
+ spin_unlock_irqrestore(&ioc->lock, flags);
+
+ put_io_context(ioc);
+}
+
+/* Called by the exiting task */
+void exit_io_context(struct task_struct *task)
+{
+ struct io_context *ioc;
+
+ task_lock(task);
+ ioc = task->io_context;
+ task->io_context = NULL;
+ task_unlock(task);
+
+ atomic_dec(&ioc->nr_tasks);
+ put_io_context_active(ioc);
+}
+
+static void __ioc_clear_queue(struct list_head *icq_list)
+{
+ unsigned long flags;
+
+ rcu_read_lock();
+ while (!list_empty(icq_list)) {
+ struct io_cq *icq = list_entry(icq_list->next,
+ struct io_cq, q_node);
+ struct io_context *ioc = icq->ioc;
+
+ spin_lock_irqsave(&ioc->lock, flags);
+ if (icq->flags & ICQ_DESTROYED) {
+ spin_unlock_irqrestore(&ioc->lock, flags);
+ continue;
+ }
+ ioc_destroy_icq(icq);
+ spin_unlock_irqrestore(&ioc->lock, flags);
+ }
+ rcu_read_unlock();
+}
+
+/**
+ * ioc_clear_queue - break any ioc association with the specified queue
+ * @q: request_queue being cleared
+ *
+ * Walk @q->icq_list and exit all io_cq's.
+ */
+void ioc_clear_queue(struct request_queue *q)
+{
+ LIST_HEAD(icq_list);
+
+ spin_lock_irq(q->queue_lock);
+ list_splice_init(&q->icq_list, &icq_list);
+
+ if (q->mq_ops) {
+ spin_unlock_irq(q->queue_lock);
+ __ioc_clear_queue(&icq_list);
+ } else {
+ __ioc_clear_queue(&icq_list);
+ spin_unlock_irq(q->queue_lock);
+ }
+}
+
+int create_task_io_context(struct task_struct *task, gfp_t gfp_flags, int node)
+{
+ struct io_context *ioc;
+ int ret;
+
+ ioc = kmem_cache_alloc_node(iocontext_cachep, gfp_flags | __GFP_ZERO,
+ node);
+ if (unlikely(!ioc))
+ return -ENOMEM;
+
+ /* initialize */
+ atomic_long_set(&ioc->refcount, 1);
+ atomic_set(&ioc->nr_tasks, 1);
+ atomic_set(&ioc->active_ref, 1);
+ spin_lock_init(&ioc->lock);
+ INIT_RADIX_TREE(&ioc->icq_tree, GFP_ATOMIC | __GFP_HIGH);
+ INIT_HLIST_HEAD(&ioc->icq_list);
+ INIT_WORK(&ioc->release_work, ioc_release_fn);
+
+ /*
+ * Try to install. ioc shouldn't be installed if someone else
+ * already did or @task, which isn't %current, is exiting. Note
+ * that we need to allow ioc creation on exiting %current as exit
+ * path may issue IOs from e.g. exit_files(). The exit path is
+ * responsible for not issuing IO after exit_io_context().
+ */
+ task_lock(task);
+ if (!task->io_context &&
+ (task == current || !(task->flags & PF_EXITING)))
+ task->io_context = ioc;
+ else
+ kmem_cache_free(iocontext_cachep, ioc);
+
+ ret = task->io_context ? 0 : -EBUSY;
+
+ task_unlock(task);
+
+ return ret;
+}
+
+/**
+ * get_task_io_context - get io_context of a task
+ * @task: task of interest
+ * @gfp_flags: allocation flags, used if allocation is necessary
+ * @node: allocation node, used if allocation is necessary
+ *
+ * Return io_context of @task. If it doesn't exist, it is created with
+ * @gfp_flags and @node. The returned io_context has its reference count
+ * incremented.
+ *
+ * This function always goes through task_lock() and it's better to use
+ * %current->io_context + get_io_context() for %current.
+ */
+struct io_context *get_task_io_context(struct task_struct *task,
+ gfp_t gfp_flags, int node)
+{
+ struct io_context *ioc;
+
+ might_sleep_if(gfpflags_allow_blocking(gfp_flags));
+
+ do {
+ task_lock(task);
+ ioc = task->io_context;
+ if (likely(ioc)) {
+ get_io_context(ioc);
+ task_unlock(task);
+ return ioc;
+ }
+ task_unlock(task);
+ } while (!create_task_io_context(task, gfp_flags, node));
+
+ return NULL;
+}
+EXPORT_SYMBOL(get_task_io_context);
+
+/**
+ * ioc_lookup_icq - lookup io_cq from ioc
+ * @ioc: the associated io_context
+ * @q: the associated request_queue
+ *
+ * Look up io_cq associated with @ioc - @q pair from @ioc. Must be called
+ * with @q->queue_lock held.
+ */
+struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q)
+{
+ struct io_cq *icq;
+
+ lockdep_assert_held(q->queue_lock);
+
+ /*
+ * icq's are indexed from @ioc using radix tree and hint pointer,
+ * both of which are protected with RCU. All removals are done
+ * holding both q and ioc locks, and we're holding q lock - if we
+ * find a icq which points to us, it's guaranteed to be valid.
+ */
+ rcu_read_lock();
+ icq = rcu_dereference(ioc->icq_hint);
+ if (icq && icq->q == q)
+ goto out;
+
+ icq = radix_tree_lookup(&ioc->icq_tree, q->id);
+ if (icq && icq->q == q)
+ rcu_assign_pointer(ioc->icq_hint, icq); /* allowed to race */
+ else
+ icq = NULL;
+out:
+ rcu_read_unlock();
+ return icq;
+}
+EXPORT_SYMBOL(ioc_lookup_icq);
+
+/**
+ * ioc_create_icq - create and link io_cq
+ * @ioc: io_context of interest
+ * @q: request_queue of interest
+ * @gfp_mask: allocation mask
+ *
+ * Make sure io_cq linking @ioc and @q exists. If icq doesn't exist, they
+ * will be created using @gfp_mask.
+ *
+ * The caller is responsible for ensuring @ioc won't go away and @q is
+ * alive and will stay alive until this function returns.
+ */
+struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
+ gfp_t gfp_mask)
+{
+ struct elevator_type *et = q->elevator->type;
+ struct io_cq *icq;
+
+ /* allocate stuff */
+ icq = kmem_cache_alloc_node(et->icq_cache, gfp_mask | __GFP_ZERO,
+ q->node);
+ if (!icq)
+ return NULL;
+
+ if (radix_tree_maybe_preload(gfp_mask) < 0) {
+ kmem_cache_free(et->icq_cache, icq);
+ return NULL;
+ }
+
+ icq->ioc = ioc;
+ icq->q = q;
+ INIT_LIST_HEAD(&icq->q_node);
+ INIT_HLIST_NODE(&icq->ioc_node);
+
+ /* lock both q and ioc and try to link @icq */
+ spin_lock_irq(q->queue_lock);
+ spin_lock(&ioc->lock);
+
+ if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) {
+ hlist_add_head(&icq->ioc_node, &ioc->icq_list);
+ list_add(&icq->q_node, &q->icq_list);
+ if (et->uses_mq && et->ops.mq.init_icq)
+ et->ops.mq.init_icq(icq);
+ else if (!et->uses_mq && et->ops.sq.elevator_init_icq_fn)
+ et->ops.sq.elevator_init_icq_fn(icq);
+ } else {
+ kmem_cache_free(et->icq_cache, icq);
+ icq = ioc_lookup_icq(ioc, q);
+ if (!icq)
+ printk(KERN_ERR "cfq: icq link failed!\n");
+ }
+
+ spin_unlock(&ioc->lock);
+ spin_unlock_irq(q->queue_lock);
+ radix_tree_preload_end();
+ return icq;
+}
+
+static int __init blk_ioc_init(void)
+{
+ iocontext_cachep = kmem_cache_create("blkdev_ioc",
+ sizeof(struct io_context), 0, SLAB_PANIC, NULL);
+ return 0;
+}
+subsys_initcall(blk_ioc_init);
diff --git a/src/kernel/linux/v4.14/block/blk-lib.c b/src/kernel/linux/v4.14/block/blk-lib.c
new file mode 100644
index 0000000..0bdc778
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-lib.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to generic helpers functions
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/scatterlist.h>
+
+#include "blk.h"
+
+static struct bio *next_bio(struct bio *bio, unsigned int nr_pages,
+ gfp_t gfp)
+{
+ struct bio *new = bio_alloc(gfp, nr_pages);
+
+ if (bio) {
+ bio_chain(bio, new);
+ submit_bio(bio);
+ }
+
+ return new;
+}
+
+int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, int flags,
+ struct bio **biop)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+ struct bio *bio = *biop;
+ unsigned int granularity;
+ unsigned int op;
+ int alignment;
+ sector_t bs_mask;
+
+ if (!q)
+ return -ENXIO;
+
+ if (flags & BLKDEV_DISCARD_SECURE) {
+ if (!blk_queue_secure_erase(q))
+ return -EOPNOTSUPP;
+ op = REQ_OP_SECURE_ERASE;
+ } else {
+ if (!blk_queue_discard(q))
+ return -EOPNOTSUPP;
+ op = REQ_OP_DISCARD;
+ }
+
+ bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+ if ((sector | nr_sects) & bs_mask)
+ return -EINVAL;
+
+ /* Zero-sector (unknown) and one-sector granularities are the same. */
+ granularity = max(q->limits.discard_granularity >> 9, 1U);
+ alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
+
+ while (nr_sects) {
+ unsigned int req_sects;
+ sector_t end_sect, tmp;
+
+ /*
+ * Issue in chunks of the user defined max discard setting,
+ * ensuring that bi_size doesn't overflow
+ */
+ req_sects = min_t(sector_t, nr_sects,
+ q->limits.max_discard_sectors);
+ if (!req_sects)
+ goto fail;
+ if (req_sects > UINT_MAX >> 9)
+ req_sects = UINT_MAX >> 9;
+
+ /*
+ * If splitting a request, and the next starting sector would be
+ * misaligned, stop the discard at the previous aligned sector.
+ */
+ end_sect = sector + req_sects;
+ tmp = end_sect;
+ if (req_sects < nr_sects &&
+ sector_div(tmp, granularity) != alignment) {
+ end_sect = end_sect - alignment;
+ sector_div(end_sect, granularity);
+ end_sect = end_sect * granularity + alignment;
+ req_sects = end_sect - sector;
+ }
+
+ bio = next_bio(bio, 0, gfp_mask);
+ bio->bi_iter.bi_sector = sector;
+ bio_set_dev(bio, bdev);
+ bio_set_op_attrs(bio, op, 0);
+
+ bio->bi_iter.bi_size = req_sects << 9;
+ nr_sects -= req_sects;
+ sector = end_sect;
+
+ /*
+ * We can loop for a long time in here, if someone does
+ * full device discards (like mkfs). Be nice and allow
+ * us to schedule out to avoid softlocking if preempt
+ * is disabled.
+ */
+ cond_resched();
+ }
+
+ *biop = bio;
+ return 0;
+
+fail:
+ if (bio) {
+ submit_bio_wait(bio);
+ bio_put(bio);
+ }
+ *biop = NULL;
+ return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL(__blkdev_issue_discard);
+
+/**
+ * blkdev_issue_discard - queue a discard
+ * @bdev: blockdev to issue discard for
+ * @sector: start sector
+ * @nr_sects: number of sectors to discard
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @flags: BLKDEV_DISCARD_* flags to control behaviour
+ *
+ * Description:
+ * Issue a discard request for the sectors in question.
+ */
+int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
+{
+ struct bio *bio = NULL;
+ struct blk_plug plug;
+ int ret;
+
+ blk_start_plug(&plug);
+ ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
+ &bio);
+ if (!ret && bio) {
+ ret = submit_bio_wait(bio);
+ if (ret == -EOPNOTSUPP)
+ ret = 0;
+ bio_put(bio);
+ }
+ blk_finish_plug(&plug);
+
+ return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_discard);
+
+/**
+ * __blkdev_issue_write_same - generate number of bios with same page
+ * @bdev: target blockdev
+ * @sector: start sector
+ * @nr_sects: number of sectors to write
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @page: page containing data to write
+ * @biop: pointer to anchor bio
+ *
+ * Description:
+ * Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page.
+ */
+static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, struct page *page,
+ struct bio **biop)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+ unsigned int max_write_same_sectors;
+ struct bio *bio = *biop;
+ sector_t bs_mask;
+
+ if (!q)
+ return -ENXIO;
+
+ bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+ if ((sector | nr_sects) & bs_mask)
+ return -EINVAL;
+
+ if (!bdev_write_same(bdev))
+ return -EOPNOTSUPP;
+
+ /* Ensure that max_write_same_sectors doesn't overflow bi_size */
+ max_write_same_sectors = UINT_MAX >> 9;
+
+ while (nr_sects) {
+ bio = next_bio(bio, 1, gfp_mask);
+ bio->bi_iter.bi_sector = sector;
+ bio_set_dev(bio, bdev);
+ bio->bi_vcnt = 1;
+ bio->bi_io_vec->bv_page = page;
+ bio->bi_io_vec->bv_offset = 0;
+ bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev);
+ bio_set_op_attrs(bio, REQ_OP_WRITE_SAME, 0);
+
+ if (nr_sects > max_write_same_sectors) {
+ bio->bi_iter.bi_size = max_write_same_sectors << 9;
+ nr_sects -= max_write_same_sectors;
+ sector += max_write_same_sectors;
+ } else {
+ bio->bi_iter.bi_size = nr_sects << 9;
+ nr_sects = 0;
+ }
+ cond_resched();
+ }
+
+ *biop = bio;
+ return 0;
+}
+
+/**
+ * blkdev_issue_write_same - queue a write same operation
+ * @bdev: target blockdev
+ * @sector: start sector
+ * @nr_sects: number of sectors to write
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @page: page containing data
+ *
+ * Description:
+ * Issue a write same request for the sectors in question.
+ */
+int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask,
+ struct page *page)
+{
+ struct bio *bio = NULL;
+ struct blk_plug plug;
+ int ret;
+
+ blk_start_plug(&plug);
+ ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page,
+ &bio);
+ if (ret == 0 && bio) {
+ ret = submit_bio_wait(bio);
+ bio_put(bio);
+ }
+ blk_finish_plug(&plug);
+ return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_write_same);
+
+static int __blkdev_issue_write_zeroes(struct block_device *bdev,
+ sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
+ struct bio **biop, unsigned flags)
+{
+ struct bio *bio = *biop;
+ unsigned int max_write_zeroes_sectors;
+ struct request_queue *q = bdev_get_queue(bdev);
+
+ if (!q)
+ return -ENXIO;
+
+ /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
+ max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
+
+ if (max_write_zeroes_sectors == 0)
+ return -EOPNOTSUPP;
+
+ while (nr_sects) {
+ bio = next_bio(bio, 0, gfp_mask);
+ bio->bi_iter.bi_sector = sector;
+ bio_set_dev(bio, bdev);
+ bio->bi_opf = REQ_OP_WRITE_ZEROES;
+ if (flags & BLKDEV_ZERO_NOUNMAP)
+ bio->bi_opf |= REQ_NOUNMAP;
+
+ if (nr_sects > max_write_zeroes_sectors) {
+ bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
+ nr_sects -= max_write_zeroes_sectors;
+ sector += max_write_zeroes_sectors;
+ } else {
+ bio->bi_iter.bi_size = nr_sects << 9;
+ nr_sects = 0;
+ }
+ cond_resched();
+ }
+
+ *biop = bio;
+ return 0;
+}
+
+/*
+ * Convert a number of 512B sectors to a number of pages.
+ * The result is limited to a number of pages that can fit into a BIO.
+ * Also make sure that the result is always at least 1 (page) for the cases
+ * where nr_sects is lower than the number of sectors in a page.
+ */
+static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
+{
+ sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
+
+ return min(pages, (sector_t)BIO_MAX_PAGES);
+}
+
+static int __blkdev_issue_zero_pages(struct block_device *bdev,
+ sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
+ struct bio **biop)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+ struct bio *bio = *biop;
+ int bi_size = 0;
+ unsigned int sz;
+
+ if (!q)
+ return -ENXIO;
+
+ while (nr_sects != 0) {
+ bio = next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
+ gfp_mask);
+ bio->bi_iter.bi_sector = sector;
+ bio_set_dev(bio, bdev);
+ bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+
+ while (nr_sects != 0) {
+ sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
+ bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
+ nr_sects -= bi_size >> 9;
+ sector += bi_size >> 9;
+ if (bi_size < sz)
+ break;
+ }
+ cond_resched();
+ }
+
+ *biop = bio;
+ return 0;
+}
+
+/**
+ * __blkdev_issue_zeroout - generate number of zero filed write bios
+ * @bdev: blockdev to issue
+ * @sector: start sector
+ * @nr_sects: number of sectors to write
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @biop: pointer to anchor bio
+ * @flags: controls detailed behavior
+ *
+ * Description:
+ * Zero-fill a block range, either using hardware offload or by explicitly
+ * writing zeroes to the device.
+ *
+ * If a device is using logical block provisioning, the underlying space will
+ * not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
+ *
+ * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
+ * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
+ */
+int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
+ unsigned flags)
+{
+ int ret;
+ sector_t bs_mask;
+
+ bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+ if ((sector | nr_sects) & bs_mask)
+ return -EINVAL;
+
+ ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
+ biop, flags);
+ if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
+ return ret;
+
+ return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
+ biop);
+}
+EXPORT_SYMBOL(__blkdev_issue_zeroout);
+
+/**
+ * blkdev_issue_zeroout - zero-fill a block range
+ * @bdev: blockdev to write
+ * @sector: start sector
+ * @nr_sects: number of sectors to write
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @flags: controls detailed behavior
+ *
+ * Description:
+ * Zero-fill a block range, either using hardware offload or by explicitly
+ * writing zeroes to the device. See __blkdev_issue_zeroout() for the
+ * valid values for %flags.
+ */
+int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
+{
+ int ret = 0;
+ sector_t bs_mask;
+ struct bio *bio;
+ struct blk_plug plug;
+ bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
+
+ bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+ if ((sector | nr_sects) & bs_mask)
+ return -EINVAL;
+
+retry:
+ bio = NULL;
+ blk_start_plug(&plug);
+ if (try_write_zeroes) {
+ ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
+ gfp_mask, &bio, flags);
+ } else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
+ ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
+ gfp_mask, &bio);
+ } else {
+ /* No zeroing offload support */
+ ret = -EOPNOTSUPP;
+ }
+ if (ret == 0 && bio) {
+ ret = submit_bio_wait(bio);
+ bio_put(bio);
+ }
+ blk_finish_plug(&plug);
+ if (ret && try_write_zeroes) {
+ if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
+ try_write_zeroes = false;
+ goto retry;
+ }
+ if (!bdev_write_zeroes_sectors(bdev)) {
+ /*
+ * Zeroing offload support was indicated, but the
+ * device reported ILLEGAL REQUEST (for some devices
+ * there is no non-destructive way to verify whether
+ * WRITE ZEROES is actually supported).
+ */
+ ret = -EOPNOTSUPP;
+ }
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_zeroout);
diff --git a/src/kernel/linux/v4.14/block/blk-map.c b/src/kernel/linux/v4.14/block/blk-map.c
new file mode 100644
index 0000000..f72a3af
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-map.c
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to mapping data to requests
+ */
+#include <linux/kernel.h>
+#include <linux/sched/task_stack.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/uio.h>
+
+#include "blk.h"
+
+/*
+ * Append a bio to a passthrough request. Only works if the bio can be merged
+ * into the request based on the driver constraints.
+ */
+int blk_rq_append_bio(struct request *rq, struct bio **bio)
+{
+ struct bio *orig_bio = *bio;
+
+ blk_queue_bounce(rq->q, bio);
+
+ if (!rq->bio) {
+ blk_rq_bio_prep(rq->q, rq, *bio);
+ } else {
+ if (!ll_back_merge_fn(rq->q, rq, *bio)) {
+ if (orig_bio != *bio) {
+ bio_put(*bio);
+ *bio = orig_bio;
+ }
+ return -EINVAL;
+ }
+
+ rq->biotail->bi_next = *bio;
+ rq->biotail = *bio;
+ rq->__data_len += (*bio)->bi_iter.bi_size;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(blk_rq_append_bio);
+
+static int __blk_rq_unmap_user(struct bio *bio)
+{
+ int ret = 0;
+
+ if (bio) {
+ if (bio_flagged(bio, BIO_USER_MAPPED))
+ bio_unmap_user(bio);
+ else
+ ret = bio_uncopy_user(bio);
+ }
+
+ return ret;
+}
+
+static int __blk_rq_map_user_iov(struct request *rq,
+ struct rq_map_data *map_data, struct iov_iter *iter,
+ gfp_t gfp_mask, bool copy)
+{
+ struct request_queue *q = rq->q;
+ struct bio *bio, *orig_bio;
+ int ret;
+
+ if (copy)
+ bio = bio_copy_user_iov(q, map_data, iter, gfp_mask);
+ else
+ bio = bio_map_user_iov(q, iter, gfp_mask);
+
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ bio->bi_opf &= ~REQ_OP_MASK;
+ bio->bi_opf |= req_op(rq);
+
+ if (map_data && map_data->null_mapped)
+ bio_set_flag(bio, BIO_NULL_MAPPED);
+
+ iov_iter_advance(iter, bio->bi_iter.bi_size);
+ if (map_data)
+ map_data->offset += bio->bi_iter.bi_size;
+
+ orig_bio = bio;
+
+ /*
+ * We link the bounce buffer in and could have to traverse it
+ * later so we have to get a ref to prevent it from being freed
+ */
+ ret = blk_rq_append_bio(rq, &bio);
+ if (ret) {
+ __blk_rq_unmap_user(orig_bio);
+ return ret;
+ }
+ bio_get(bio);
+
+ return 0;
+}
+
+/**
+ * blk_rq_map_user_iov - map user data to a request, for passthrough requests
+ * @q: request queue where request should be inserted
+ * @rq: request to map data to
+ * @map_data: pointer to the rq_map_data holding pages (if necessary)
+ * @iter: iovec iterator
+ * @gfp_mask: memory allocation flags
+ *
+ * Description:
+ * Data will be mapped directly for zero copy I/O, if possible. Otherwise
+ * a kernel bounce buffer is used.
+ *
+ * A matching blk_rq_unmap_user() must be issued at the end of I/O, while
+ * still in process context.
+ *
+ * Note: The mapped bio may need to be bounced through blk_queue_bounce()
+ * before being submitted to the device, as pages mapped may be out of
+ * reach. It's the callers responsibility to make sure this happens. The
+ * original bio must be passed back in to blk_rq_unmap_user() for proper
+ * unmapping.
+ */
+int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
+ struct rq_map_data *map_data,
+ const struct iov_iter *iter, gfp_t gfp_mask)
+{
+ bool copy = false;
+ unsigned long align = q->dma_pad_mask | queue_dma_alignment(q);
+ struct bio *bio = NULL;
+ struct iov_iter i;
+ int ret = -EINVAL;
+
+ if (!iter_is_iovec(iter))
+ goto fail;
+
+ if (map_data)
+ copy = true;
+ else if (iov_iter_alignment(iter) & align)
+ copy = true;
+ else if (queue_virt_boundary(q))
+ copy = queue_virt_boundary(q) & iov_iter_gap_alignment(iter);
+
+ i = *iter;
+ do {
+ ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy);
+ if (ret)
+ goto unmap_rq;
+ if (!bio)
+ bio = rq->bio;
+ } while (iov_iter_count(&i));
+
+ if (!bio_flagged(bio, BIO_USER_MAPPED))
+ rq->rq_flags |= RQF_COPY_USER;
+ return 0;
+
+unmap_rq:
+ blk_rq_unmap_user(bio);
+fail:
+ rq->bio = NULL;
+ return ret;
+}
+EXPORT_SYMBOL(blk_rq_map_user_iov);
+
+int blk_rq_map_user(struct request_queue *q, struct request *rq,
+ struct rq_map_data *map_data, void __user *ubuf,
+ unsigned long len, gfp_t gfp_mask)
+{
+ struct iovec iov;
+ struct iov_iter i;
+ int ret = import_single_range(rq_data_dir(rq), ubuf, len, &iov, &i);
+
+ if (unlikely(ret < 0))
+ return ret;
+
+ return blk_rq_map_user_iov(q, rq, map_data, &i, gfp_mask);
+}
+EXPORT_SYMBOL(blk_rq_map_user);
+
+/**
+ * blk_rq_unmap_user - unmap a request with user data
+ * @bio: start of bio list
+ *
+ * Description:
+ * Unmap a rq previously mapped by blk_rq_map_user(). The caller must
+ * supply the original rq->bio from the blk_rq_map_user() return, since
+ * the I/O completion may have changed rq->bio.
+ */
+int blk_rq_unmap_user(struct bio *bio)
+{
+ struct bio *mapped_bio;
+ int ret = 0, ret2;
+
+ while (bio) {
+ mapped_bio = bio;
+ if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
+ mapped_bio = bio->bi_private;
+
+ ret2 = __blk_rq_unmap_user(mapped_bio);
+ if (ret2 && !ret)
+ ret = ret2;
+
+ mapped_bio = bio;
+ bio = bio->bi_next;
+ bio_put(mapped_bio);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(blk_rq_unmap_user);
+
+/**
+ * blk_rq_map_kern - map kernel data to a request, for passthrough requests
+ * @q: request queue where request should be inserted
+ * @rq: request to fill
+ * @kbuf: the kernel buffer
+ * @len: length of user data
+ * @gfp_mask: memory allocation flags
+ *
+ * Description:
+ * Data will be mapped directly if possible. Otherwise a bounce
+ * buffer is used. Can be called multiple times to append multiple
+ * buffers.
+ */
+int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
+ unsigned int len, gfp_t gfp_mask)
+{
+ int reading = rq_data_dir(rq) == READ;
+ unsigned long addr = (unsigned long) kbuf;
+ int do_copy = 0;
+ struct bio *bio, *orig_bio;
+ int ret;
+
+ if (len > (queue_max_hw_sectors(q) << 9))
+ return -EINVAL;
+ if (!len || !kbuf)
+ return -EINVAL;
+
+ do_copy = !blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf);
+ if (do_copy)
+ bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
+ else
+ bio = bio_map_kern(q, kbuf, len, gfp_mask);
+
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ bio->bi_opf &= ~REQ_OP_MASK;
+ bio->bi_opf |= req_op(rq);
+
+ if (do_copy)
+ rq->rq_flags |= RQF_COPY_USER;
+
+ orig_bio = bio;
+ ret = blk_rq_append_bio(rq, &bio);
+ if (unlikely(ret)) {
+ /* request is too big */
+ bio_put(orig_bio);
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(blk_rq_map_kern);
diff --git a/src/kernel/linux/v4.14/block/blk-merge.c b/src/kernel/linux/v4.14/block/blk-merge.c
new file mode 100644
index 0000000..415b5da
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-merge.c
@@ -0,0 +1,865 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to segment and merge handling
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/scatterlist.h>
+
+#include <trace/events/block.h>
+
+#include "blk.h"
+
+static struct bio *blk_bio_discard_split(struct request_queue *q,
+ struct bio *bio,
+ struct bio_set *bs,
+ unsigned *nsegs)
+{
+ unsigned int max_discard_sectors, granularity;
+ int alignment;
+ sector_t tmp;
+ unsigned split_sectors;
+
+ *nsegs = 1;
+
+ /* Zero-sector (unknown) and one-sector granularities are the same. */
+ granularity = max(q->limits.discard_granularity >> 9, 1U);
+
+ max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+ max_discard_sectors -= max_discard_sectors % granularity;
+
+ if (unlikely(!max_discard_sectors)) {
+ /* XXX: warn */
+ return NULL;
+ }
+
+ if (bio_sectors(bio) <= max_discard_sectors)
+ return NULL;
+
+ split_sectors = max_discard_sectors;
+
+ /*
+ * If the next starting sector would be misaligned, stop the discard at
+ * the previous aligned sector.
+ */
+ alignment = (q->limits.discard_alignment >> 9) % granularity;
+
+ tmp = bio->bi_iter.bi_sector + split_sectors - alignment;
+ tmp = sector_div(tmp, granularity);
+
+ if (split_sectors > tmp)
+ split_sectors -= tmp;
+
+ return bio_split(bio, split_sectors, GFP_NOIO, bs);
+}
+
+static struct bio *blk_bio_write_zeroes_split(struct request_queue *q,
+ struct bio *bio, struct bio_set *bs, unsigned *nsegs)
+{
+ *nsegs = 1;
+
+ if (!q->limits.max_write_zeroes_sectors)
+ return NULL;
+
+ if (bio_sectors(bio) <= q->limits.max_write_zeroes_sectors)
+ return NULL;
+
+ return bio_split(bio, q->limits.max_write_zeroes_sectors, GFP_NOIO, bs);
+}
+
+static struct bio *blk_bio_write_same_split(struct request_queue *q,
+ struct bio *bio,
+ struct bio_set *bs,
+ unsigned *nsegs)
+{
+ *nsegs = 1;
+
+ if (!q->limits.max_write_same_sectors)
+ return NULL;
+
+ if (bio_sectors(bio) <= q->limits.max_write_same_sectors)
+ return NULL;
+
+ return bio_split(bio, q->limits.max_write_same_sectors, GFP_NOIO, bs);
+}
+
+static inline unsigned get_max_io_size(struct request_queue *q,
+ struct bio *bio)
+{
+ unsigned sectors = blk_max_size_offset(q, bio->bi_iter.bi_sector);
+ unsigned mask = queue_logical_block_size(q) - 1;
+
+ /* aligned to logical block size */
+ sectors &= ~(mask >> 9);
+
+ return sectors;
+}
+
+static struct bio *blk_bio_segment_split(struct request_queue *q,
+ struct bio *bio,
+ struct bio_set *bs,
+ unsigned *segs)
+{
+ struct bio_vec bv, bvprv, *bvprvp = NULL;
+ struct bvec_iter iter;
+ unsigned seg_size = 0, nsegs = 0, sectors = 0;
+ unsigned front_seg_size = bio->bi_seg_front_size;
+ bool do_split = true;
+ struct bio *new = NULL;
+ const unsigned max_sectors = get_max_io_size(q, bio);
+
+ bio_for_each_segment(bv, bio, iter) {
+ /*
+ * If the queue doesn't support SG gaps and adding this
+ * offset would create a gap, disallow it.
+ */
+ if (bvprvp && bvec_gap_to_prev(q, bvprvp, bv.bv_offset))
+ goto split;
+
+ if (sectors + (bv.bv_len >> 9) > max_sectors) {
+ /*
+ * Consider this a new segment if we're splitting in
+ * the middle of this vector.
+ */
+ if (nsegs < queue_max_segments(q) &&
+ sectors < max_sectors) {
+ nsegs++;
+ sectors = max_sectors;
+ }
+ if (sectors)
+ goto split;
+ /* Make this single bvec as the 1st segment */
+ }
+
+ if (bvprvp && blk_queue_cluster(q)) {
+ if (seg_size + bv.bv_len > queue_max_segment_size(q))
+ goto new_segment;
+ if (!BIOVEC_PHYS_MERGEABLE(bvprvp, &bv))
+ goto new_segment;
+ if (!BIOVEC_SEG_BOUNDARY(q, bvprvp, &bv))
+ goto new_segment;
+
+ seg_size += bv.bv_len;
+ bvprv = bv;
+ bvprvp = &bvprv;
+ sectors += bv.bv_len >> 9;
+
+ if (nsegs == 1 && seg_size > front_seg_size)
+ front_seg_size = seg_size;
+ continue;
+ }
+new_segment:
+ if (nsegs == queue_max_segments(q))
+ goto split;
+
+ nsegs++;
+ bvprv = bv;
+ bvprvp = &bvprv;
+ seg_size = bv.bv_len;
+ sectors += bv.bv_len >> 9;
+
+ if (nsegs == 1 && seg_size > front_seg_size)
+ front_seg_size = seg_size;
+ }
+
+ do_split = false;
+split:
+ *segs = nsegs;
+
+ if (do_split) {
+ new = bio_split(bio, sectors, GFP_NOIO, bs);
+ if (new)
+ bio = new;
+ }
+
+ bio->bi_seg_front_size = front_seg_size;
+ if (seg_size > bio->bi_seg_back_size)
+ bio->bi_seg_back_size = seg_size;
+
+ return do_split ? new : NULL;
+}
+
+void blk_queue_split(struct request_queue *q, struct bio **bio)
+{
+ struct bio *split, *res;
+ unsigned nsegs;
+
+ switch (bio_op(*bio)) {
+ case REQ_OP_DISCARD:
+ case REQ_OP_SECURE_ERASE:
+ split = blk_bio_discard_split(q, *bio, q->bio_split, &nsegs);
+ break;
+ case REQ_OP_WRITE_ZEROES:
+ split = blk_bio_write_zeroes_split(q, *bio, q->bio_split, &nsegs);
+ break;
+ case REQ_OP_WRITE_SAME:
+ split = blk_bio_write_same_split(q, *bio, q->bio_split, &nsegs);
+ break;
+ default:
+ split = blk_bio_segment_split(q, *bio, q->bio_split, &nsegs);
+ break;
+ }
+
+ /* physical segments can be figured out during splitting */
+ res = split ? split : *bio;
+ res->bi_phys_segments = nsegs;
+ bio_set_flag(res, BIO_SEG_VALID);
+
+ if (split) {
+ /* there isn't chance to merge the splitted bio */
+ split->bi_opf |= REQ_NOMERGE;
+
+ bio_chain(split, *bio);
+ trace_block_split(q, split, (*bio)->bi_iter.bi_sector);
+ generic_make_request(*bio);
+ *bio = split;
+ }
+}
+EXPORT_SYMBOL(blk_queue_split);
+
+static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
+ struct bio *bio,
+ bool no_sg_merge)
+{
+ struct bio_vec bv, bvprv = { NULL };
+ int cluster, prev = 0;
+ unsigned int seg_size, nr_phys_segs;
+ struct bio *fbio, *bbio;
+ struct bvec_iter iter;
+
+ if (!bio)
+ return 0;
+
+ switch (bio_op(bio)) {
+ case REQ_OP_DISCARD:
+ case REQ_OP_SECURE_ERASE:
+ case REQ_OP_WRITE_ZEROES:
+ return 0;
+ case REQ_OP_WRITE_SAME:
+ return 1;
+ }
+
+ fbio = bio;
+ cluster = blk_queue_cluster(q);
+ seg_size = 0;
+ nr_phys_segs = 0;
+ for_each_bio(bio) {
+ bio_for_each_segment(bv, bio, iter) {
+ /*
+ * If SG merging is disabled, each bio vector is
+ * a segment
+ */
+ if (no_sg_merge)
+ goto new_segment;
+
+ if (prev && cluster) {
+ if (seg_size + bv.bv_len
+ > queue_max_segment_size(q))
+ goto new_segment;
+ if (!BIOVEC_PHYS_MERGEABLE(&bvprv, &bv))
+ goto new_segment;
+ if (!BIOVEC_SEG_BOUNDARY(q, &bvprv, &bv))
+ goto new_segment;
+
+ seg_size += bv.bv_len;
+ bvprv = bv;
+ continue;
+ }
+new_segment:
+ if (nr_phys_segs == 1 && seg_size >
+ fbio->bi_seg_front_size)
+ fbio->bi_seg_front_size = seg_size;
+
+ nr_phys_segs++;
+ bvprv = bv;
+ prev = 1;
+ seg_size = bv.bv_len;
+ }
+ bbio = bio;
+ }
+
+ if (nr_phys_segs == 1 && seg_size > fbio->bi_seg_front_size)
+ fbio->bi_seg_front_size = seg_size;
+ if (seg_size > bbio->bi_seg_back_size)
+ bbio->bi_seg_back_size = seg_size;
+
+ return nr_phys_segs;
+}
+
+void blk_recalc_rq_segments(struct request *rq)
+{
+ bool no_sg_merge = !!test_bit(QUEUE_FLAG_NO_SG_MERGE,
+ &rq->q->queue_flags);
+
+ rq->nr_phys_segments = __blk_recalc_rq_segments(rq->q, rq->bio,
+ no_sg_merge);
+}
+
+void blk_recount_segments(struct request_queue *q, struct bio *bio)
+{
+ unsigned short seg_cnt = bio_segments(bio);
+
+ if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) &&
+ (seg_cnt < queue_max_segments(q)))
+ bio->bi_phys_segments = seg_cnt;
+ else {
+ struct bio *nxt = bio->bi_next;
+
+ bio->bi_next = NULL;
+ bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, false);
+ bio->bi_next = nxt;
+ }
+
+ bio_set_flag(bio, BIO_SEG_VALID);
+}
+EXPORT_SYMBOL(blk_recount_segments);
+
+static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
+ struct bio *nxt)
+{
+ struct bio_vec end_bv = { NULL }, nxt_bv;
+
+ if (!blk_queue_cluster(q))
+ return 0;
+
+ if (bio->bi_seg_back_size + nxt->bi_seg_front_size >
+ queue_max_segment_size(q))
+ return 0;
+
+ if (!bio_has_data(bio))
+ return 1;
+
+ bio_get_last_bvec(bio, &end_bv);
+ bio_get_first_bvec(nxt, &nxt_bv);
+
+ if (!BIOVEC_PHYS_MERGEABLE(&end_bv, &nxt_bv))
+ return 0;
+
+ /*
+ * bio and nxt are contiguous in memory; check if the queue allows
+ * these two to be merged into one
+ */
+ if (BIOVEC_SEG_BOUNDARY(q, &end_bv, &nxt_bv))
+ return 1;
+
+ return 0;
+}
+
+static inline void
+__blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec,
+ struct scatterlist *sglist, struct bio_vec *bvprv,
+ struct scatterlist **sg, int *nsegs, int *cluster)
+{
+
+ int nbytes = bvec->bv_len;
+
+ if (*sg && *cluster) {
+ if ((*sg)->length + nbytes > queue_max_segment_size(q))
+ goto new_segment;
+
+ if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec))
+ goto new_segment;
+ if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec))
+ goto new_segment;
+
+ (*sg)->length += nbytes;
+ } else {
+new_segment:
+ if (!*sg)
+ *sg = sglist;
+ else {
+ /*
+ * If the driver previously mapped a shorter
+ * list, we could see a termination bit
+ * prematurely unless it fully inits the sg
+ * table on each mapping. We KNOW that there
+ * must be more entries here or the driver
+ * would be buggy, so force clear the
+ * termination bit to avoid doing a full
+ * sg_init_table() in drivers for each command.
+ */
+ sg_unmark_end(*sg);
+ *sg = sg_next(*sg);
+ }
+
+ sg_set_page(*sg, bvec->bv_page, nbytes, bvec->bv_offset);
+ (*nsegs)++;
+ }
+ *bvprv = *bvec;
+}
+
+static inline int __blk_bvec_map_sg(struct request_queue *q, struct bio_vec bv,
+ struct scatterlist *sglist, struct scatterlist **sg)
+{
+ *sg = sglist;
+ sg_set_page(*sg, bv.bv_page, bv.bv_len, bv.bv_offset);
+ return 1;
+}
+
+static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio,
+ struct scatterlist *sglist,
+ struct scatterlist **sg)
+{
+ struct bio_vec bvec, bvprv = { NULL };
+ struct bvec_iter iter;
+ int cluster = blk_queue_cluster(q), nsegs = 0;
+
+ for_each_bio(bio)
+ bio_for_each_segment(bvec, bio, iter)
+ __blk_segment_map_sg(q, &bvec, sglist, &bvprv, sg,
+ &nsegs, &cluster);
+
+ return nsegs;
+}
+
+/*
+ * map a request to scatterlist, return number of sg entries setup. Caller
+ * must make sure sg can hold rq->nr_phys_segments entries
+ */
+int blk_rq_map_sg(struct request_queue *q, struct request *rq,
+ struct scatterlist *sglist)
+{
+ struct scatterlist *sg = NULL;
+ int nsegs = 0;
+
+ if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
+ nsegs = __blk_bvec_map_sg(q, rq->special_vec, sglist, &sg);
+ else if (rq->bio && bio_op(rq->bio) == REQ_OP_WRITE_SAME)
+ nsegs = __blk_bvec_map_sg(q, bio_iovec(rq->bio), sglist, &sg);
+ else if (rq->bio)
+ nsegs = __blk_bios_map_sg(q, rq->bio, sglist, &sg);
+
+ if (unlikely(rq->rq_flags & RQF_COPY_USER) &&
+ (blk_rq_bytes(rq) & q->dma_pad_mask)) {
+ unsigned int pad_len =
+ (q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1;
+
+ sg->length += pad_len;
+ rq->extra_len += pad_len;
+ }
+
+ if (q->dma_drain_size && q->dma_drain_needed(rq)) {
+ if (op_is_write(req_op(rq)))
+ memset(q->dma_drain_buffer, 0, q->dma_drain_size);
+
+ sg_unmark_end(sg);
+ sg = sg_next(sg);
+ sg_set_page(sg, virt_to_page(q->dma_drain_buffer),
+ q->dma_drain_size,
+ ((unsigned long)q->dma_drain_buffer) &
+ (PAGE_SIZE - 1));
+ nsegs++;
+ rq->extra_len += q->dma_drain_size;
+ }
+
+ if (sg)
+ sg_mark_end(sg);
+
+ /*
+ * Something must have been wrong if the figured number of
+ * segment is bigger than number of req's physical segments
+ */
+ WARN_ON(nsegs > blk_rq_nr_phys_segments(rq));
+
+ return nsegs;
+}
+EXPORT_SYMBOL(blk_rq_map_sg);
+
+static inline int ll_new_hw_segment(struct request_queue *q,
+ struct request *req,
+ struct bio *bio)
+{
+ int nr_phys_segs = bio_phys_segments(q, bio);
+
+ if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q))
+ goto no_merge;
+
+ if (blk_integrity_merge_bio(q, req, bio) == false)
+ goto no_merge;
+
+ /*
+ * This will form the start of a new hw segment. Bump both
+ * counters.
+ */
+ req->nr_phys_segments += nr_phys_segs;
+ return 1;
+
+no_merge:
+ req_set_nomerge(q, req);
+ return 0;
+}
+
+int ll_back_merge_fn(struct request_queue *q, struct request *req,
+ struct bio *bio)
+{
+ if (req_gap_back_merge(req, bio))
+ return 0;
+ if (blk_integrity_rq(req) &&
+ integrity_req_gap_back_merge(req, bio))
+ return 0;
+ if (blk_rq_sectors(req) + bio_sectors(bio) >
+ blk_rq_get_max_sectors(req, blk_rq_pos(req))) {
+ req_set_nomerge(q, req);
+ return 0;
+ }
+ if (!bio_flagged(req->biotail, BIO_SEG_VALID))
+ blk_recount_segments(q, req->biotail);
+ if (!bio_flagged(bio, BIO_SEG_VALID))
+ blk_recount_segments(q, bio);
+
+ return ll_new_hw_segment(q, req, bio);
+}
+
+int ll_front_merge_fn(struct request_queue *q, struct request *req,
+ struct bio *bio)
+{
+
+ if (req_gap_front_merge(req, bio))
+ return 0;
+ if (blk_integrity_rq(req) &&
+ integrity_req_gap_front_merge(req, bio))
+ return 0;
+ if (blk_rq_sectors(req) + bio_sectors(bio) >
+ blk_rq_get_max_sectors(req, bio->bi_iter.bi_sector)) {
+ req_set_nomerge(q, req);
+ return 0;
+ }
+ if (!bio_flagged(bio, BIO_SEG_VALID))
+ blk_recount_segments(q, bio);
+ if (!bio_flagged(req->bio, BIO_SEG_VALID))
+ blk_recount_segments(q, req->bio);
+
+ return ll_new_hw_segment(q, req, bio);
+}
+
+/*
+ * blk-mq uses req->special to carry normal driver per-request payload, it
+ * does not indicate a prepared command that we cannot merge with.
+ */
+static bool req_no_special_merge(struct request *req)
+{
+ struct request_queue *q = req->q;
+
+ return !q->mq_ops && req->special;
+}
+
+static bool req_attempt_discard_merge(struct request_queue *q, struct request *req,
+ struct request *next)
+{
+ unsigned short segments = blk_rq_nr_discard_segments(req);
+
+ if (segments >= queue_max_discard_segments(q))
+ goto no_merge;
+ if (blk_rq_sectors(req) + bio_sectors(next->bio) >
+ blk_rq_get_max_sectors(req, blk_rq_pos(req)))
+ goto no_merge;
+
+ req->nr_phys_segments = segments + blk_rq_nr_discard_segments(next);
+ return true;
+no_merge:
+ req_set_nomerge(q, req);
+ return false;
+}
+
+static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
+ struct request *next)
+{
+ int total_phys_segments;
+ unsigned int seg_size =
+ req->biotail->bi_seg_back_size + next->bio->bi_seg_front_size;
+
+ /*
+ * First check if the either of the requests are re-queued
+ * requests. Can't merge them if they are.
+ */
+ if (req_no_special_merge(req) || req_no_special_merge(next))
+ return 0;
+
+ if (req_gap_back_merge(req, next->bio))
+ return 0;
+
+ /*
+ * Will it become too large?
+ */
+ if ((blk_rq_sectors(req) + blk_rq_sectors(next)) >
+ blk_rq_get_max_sectors(req, blk_rq_pos(req)))
+ return 0;
+
+ total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
+ if (blk_phys_contig_segment(q, req->biotail, next->bio)) {
+ if (req->nr_phys_segments == 1)
+ req->bio->bi_seg_front_size = seg_size;
+ if (next->nr_phys_segments == 1)
+ next->biotail->bi_seg_back_size = seg_size;
+ total_phys_segments--;
+ }
+
+ if (total_phys_segments > queue_max_segments(q))
+ return 0;
+
+ if (blk_integrity_merge_rq(q, req, next) == false)
+ return 0;
+
+ /* Merge is OK... */
+ req->nr_phys_segments = total_phys_segments;
+ return 1;
+}
+
+/**
+ * blk_rq_set_mixed_merge - mark a request as mixed merge
+ * @rq: request to mark as mixed merge
+ *
+ * Description:
+ * @rq is about to be mixed merged. Make sure the attributes
+ * which can be mixed are set in each bio and mark @rq as mixed
+ * merged.
+ */
+void blk_rq_set_mixed_merge(struct request *rq)
+{
+ unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK;
+ struct bio *bio;
+
+ if (rq->rq_flags & RQF_MIXED_MERGE)
+ return;
+
+ /*
+ * @rq will no longer represent mixable attributes for all the
+ * contained bios. It will just track those of the first one.
+ * Distributes the attributs to each bio.
+ */
+ for (bio = rq->bio; bio; bio = bio->bi_next) {
+ WARN_ON_ONCE((bio->bi_opf & REQ_FAILFAST_MASK) &&
+ (bio->bi_opf & REQ_FAILFAST_MASK) != ff);
+ bio->bi_opf |= ff;
+ }
+ rq->rq_flags |= RQF_MIXED_MERGE;
+}
+
+static void blk_account_io_merge(struct request *req)
+{
+ if (blk_do_io_stat(req)) {
+ struct hd_struct *part;
+ int cpu;
+
+ cpu = part_stat_lock();
+ part = req->part;
+
+ part_round_stats(req->q, cpu, part);
+ part_dec_in_flight(req->q, part, rq_data_dir(req));
+
+ hd_struct_put(part);
+ part_stat_unlock();
+ }
+}
+/*
+ * Two cases of handling DISCARD merge:
+ * If max_discard_segments > 1, the driver takes every bio
+ * as a range and send them to controller together. The ranges
+ * needn't to be contiguous.
+ * Otherwise, the bios/requests will be handled as same as
+ * others which should be contiguous.
+ */
+static inline bool blk_discard_mergable(struct request *req)
+{
+ if (req_op(req) == REQ_OP_DISCARD &&
+ queue_max_discard_segments(req->q) > 1)
+ return true;
+ return false;
+}
+
+enum elv_merge blk_try_req_merge(struct request *req, struct request *next)
+{
+ if (blk_discard_mergable(req))
+ return ELEVATOR_DISCARD_MERGE;
+ else if (blk_rq_pos(req) + blk_rq_sectors(req) == blk_rq_pos(next))
+ return ELEVATOR_BACK_MERGE;
+
+ return ELEVATOR_NO_MERGE;
+}
+
+/*
+ * For non-mq, this has to be called with the request spinlock acquired.
+ * For mq with scheduling, the appropriate queue wide lock should be held.
+ */
+static struct request *attempt_merge(struct request_queue *q,
+ struct request *req, struct request *next)
+{
+ if (!q->mq_ops)
+ lockdep_assert_held(q->queue_lock);
+
+ if (!rq_mergeable(req) || !rq_mergeable(next))
+ return NULL;
+
+ if (req_op(req) != req_op(next))
+ return NULL;
+
+ if (rq_data_dir(req) != rq_data_dir(next)
+ || req->rq_disk != next->rq_disk
+ || req_no_special_merge(next))
+ return NULL;
+
+ if (req_op(req) == REQ_OP_WRITE_SAME &&
+ !blk_write_same_mergeable(req->bio, next->bio))
+ return NULL;
+
+ /*
+ * Don't allow merge of different write hints, or for a hint with
+ * non-hint IO.
+ */
+ if (req->write_hint != next->write_hint)
+ return NULL;
+
+ /*
+ * If we are allowed to merge, then append bio list
+ * from next to rq and release next. merge_requests_fn
+ * will have updated segment counts, update sector
+ * counts here. Handle DISCARDs separately, as they
+ * have separate settings.
+ */
+
+ switch (blk_try_req_merge(req, next)) {
+ case ELEVATOR_DISCARD_MERGE:
+ if (!req_attempt_discard_merge(q, req, next))
+ return NULL;
+ break;
+ case ELEVATOR_BACK_MERGE:
+ if (!ll_merge_requests_fn(q, req, next))
+ return NULL;
+ break;
+ default:
+ return NULL;
+ }
+
+ /*
+ * If failfast settings disagree or any of the two is already
+ * a mixed merge, mark both as mixed before proceeding. This
+ * makes sure that all involved bios have mixable attributes
+ * set properly.
+ */
+ if (((req->rq_flags | next->rq_flags) & RQF_MIXED_MERGE) ||
+ (req->cmd_flags & REQ_FAILFAST_MASK) !=
+ (next->cmd_flags & REQ_FAILFAST_MASK)) {
+ blk_rq_set_mixed_merge(req);
+ blk_rq_set_mixed_merge(next);
+ }
+
+ /*
+ * At this point we have either done a back merge
+ * or front merge. We need the smaller start_time of
+ * the merged requests to be the current request
+ * for accounting purposes.
+ */
+ if (time_after(req->start_time, next->start_time))
+ req->start_time = next->start_time;
+
+ req->biotail->bi_next = next->bio;
+ req->biotail = next->biotail;
+
+ req->__data_len += blk_rq_bytes(next);
+
+ if (!blk_discard_mergable(req))
+ elv_merge_requests(q, req, next);
+
+ /*
+ * 'next' is going away, so update stats accordingly
+ */
+ blk_account_io_merge(next);
+
+ req->ioprio = ioprio_best(req->ioprio, next->ioprio);
+ if (blk_rq_cpu_valid(next))
+ req->cpu = next->cpu;
+
+ /*
+ * ownership of bio passed from next to req, return 'next' for
+ * the caller to free
+ */
+ next->bio = NULL;
+ return next;
+}
+
+struct request *attempt_back_merge(struct request_queue *q, struct request *rq)
+{
+ struct request *next = elv_latter_request(q, rq);
+
+ if (next)
+ return attempt_merge(q, rq, next);
+
+ return NULL;
+}
+
+struct request *attempt_front_merge(struct request_queue *q, struct request *rq)
+{
+ struct request *prev = elv_former_request(q, rq);
+
+ if (prev)
+ return attempt_merge(q, prev, rq);
+
+ return NULL;
+}
+
+int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
+ struct request *next)
+{
+ struct elevator_queue *e = q->elevator;
+ struct request *free;
+
+ if (!e->uses_mq && e->type->ops.sq.elevator_allow_rq_merge_fn)
+ if (!e->type->ops.sq.elevator_allow_rq_merge_fn(q, rq, next))
+ return 0;
+
+ free = attempt_merge(q, rq, next);
+ if (free) {
+ __blk_put_request(q, free);
+ return 1;
+ }
+
+ return 0;
+}
+
+bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
+{
+ if (!rq_mergeable(rq) || !bio_mergeable(bio))
+ return false;
+
+ if (req_op(rq) != bio_op(bio))
+ return false;
+
+ /* different data direction or already started, don't merge */
+ if (bio_data_dir(bio) != rq_data_dir(rq))
+ return false;
+
+ /* must be same device and not a special request */
+ if (rq->rq_disk != bio->bi_disk || req_no_special_merge(rq))
+ return false;
+
+ /* only merge integrity protected bio into ditto rq */
+ if (blk_integrity_merge_bio(rq->q, rq, bio) == false)
+ return false;
+
+ /* must be using the same buffer */
+ if (req_op(rq) == REQ_OP_WRITE_SAME &&
+ !blk_write_same_mergeable(rq->bio, bio))
+ return false;
+
+ /*
+ * Don't allow merge of different write hints, or for a hint with
+ * non-hint IO.
+ */
+ if (rq->write_hint != bio->bi_write_hint)
+ return false;
+
+ return true;
+}
+
+enum elv_merge blk_try_merge(struct request *rq, struct bio *bio)
+{
+ if (blk_discard_mergable(rq))
+ return ELEVATOR_DISCARD_MERGE;
+ else if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_iter.bi_sector)
+ return ELEVATOR_BACK_MERGE;
+ else if (blk_rq_pos(rq) - bio_sectors(bio) == bio->bi_iter.bi_sector)
+ return ELEVATOR_FRONT_MERGE;
+ return ELEVATOR_NO_MERGE;
+}
diff --git a/src/kernel/linux/v4.14/block/blk-mq-cpumap.c b/src/kernel/linux/v4.14/block/blk-mq-cpumap.c
new file mode 100644
index 0000000..3eb169f
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-cpumap.c
@@ -0,0 +1,75 @@
+/*
+ * CPU <-> hardware queue mapping helpers
+ *
+ * Copyright (C) 2013-2014 Jens Axboe
+ */
+#include <linux/kernel.h>
+#include <linux/threads.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+
+#include <linux/blk-mq.h>
+#include "blk.h"
+#include "blk-mq.h"
+
+static int cpu_to_queue_index(unsigned int nr_queues, const int cpu)
+{
+ return cpu % nr_queues;
+}
+
+static int get_first_sibling(unsigned int cpu)
+{
+ unsigned int ret;
+
+ ret = cpumask_first(topology_sibling_cpumask(cpu));
+ if (ret < nr_cpu_ids)
+ return ret;
+
+ return cpu;
+}
+
+int blk_mq_map_queues(struct blk_mq_tag_set *set)
+{
+ unsigned int *map = set->mq_map;
+ unsigned int nr_queues = set->nr_hw_queues;
+ unsigned int cpu, first_sibling;
+
+ for_each_possible_cpu(cpu) {
+ /*
+ * First do sequential mapping between CPUs and queues.
+ * In case we still have CPUs to map, and we have some number of
+ * threads per cores then map sibling threads to the same queue for
+ * performace optimizations.
+ */
+ if (cpu < nr_queues) {
+ map[cpu] = cpu_to_queue_index(nr_queues, cpu);
+ } else {
+ first_sibling = get_first_sibling(cpu);
+ if (first_sibling == cpu)
+ map[cpu] = cpu_to_queue_index(nr_queues, cpu);
+ else
+ map[cpu] = map[first_sibling];
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blk_mq_map_queues);
+
+/*
+ * We have no quick way of doing reverse lookups. This is only used at
+ * queue init time, so runtime isn't important.
+ */
+int blk_mq_hw_queue_to_node(unsigned int *mq_map, unsigned int index)
+{
+ int i;
+
+ for_each_possible_cpu(i) {
+ if (index == mq_map[i])
+ return local_memory_node(cpu_to_node(i));
+ }
+
+ return NUMA_NO_NODE;
+}
diff --git a/src/kernel/linux/v4.14/block/blk-mq-debugfs.c b/src/kernel/linux/v4.14/block/blk-mq-debugfs.c
new file mode 100644
index 0000000..d954391
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-debugfs.c
@@ -0,0 +1,987 @@
+/*
+ * Copyright (C) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/debugfs.h>
+
+#include <linux/blk-mq.h>
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-debugfs.h"
+#include "blk-mq-tag.h"
+
+static int blk_flags_show(struct seq_file *m, const unsigned long flags,
+ const char *const *flag_name, int flag_name_count)
+{
+ bool sep = false;
+ int i;
+
+ for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
+ if (!(flags & BIT(i)))
+ continue;
+ if (sep)
+ seq_puts(m, "|");
+ sep = true;
+ if (i < flag_name_count && flag_name[i])
+ seq_puts(m, flag_name[i]);
+ else
+ seq_printf(m, "%d", i);
+ }
+ return 0;
+}
+
+#define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
+static const char *const blk_queue_flag_name[] = {
+ QUEUE_FLAG_NAME(QUEUED),
+ QUEUE_FLAG_NAME(STOPPED),
+ QUEUE_FLAG_NAME(DYING),
+ QUEUE_FLAG_NAME(BYPASS),
+ QUEUE_FLAG_NAME(BIDI),
+ QUEUE_FLAG_NAME(NOMERGES),
+ QUEUE_FLAG_NAME(SAME_COMP),
+ QUEUE_FLAG_NAME(FAIL_IO),
+ QUEUE_FLAG_NAME(STACKABLE),
+ QUEUE_FLAG_NAME(NONROT),
+ QUEUE_FLAG_NAME(IO_STAT),
+ QUEUE_FLAG_NAME(DISCARD),
+ QUEUE_FLAG_NAME(NOXMERGES),
+ QUEUE_FLAG_NAME(ADD_RANDOM),
+ QUEUE_FLAG_NAME(SECERASE),
+ QUEUE_FLAG_NAME(SAME_FORCE),
+ QUEUE_FLAG_NAME(DEAD),
+ QUEUE_FLAG_NAME(INIT_DONE),
+ QUEUE_FLAG_NAME(NO_SG_MERGE),
+ QUEUE_FLAG_NAME(POLL),
+ QUEUE_FLAG_NAME(WC),
+ QUEUE_FLAG_NAME(FUA),
+ QUEUE_FLAG_NAME(FLUSH_NQ),
+ QUEUE_FLAG_NAME(DAX),
+ QUEUE_FLAG_NAME(STATS),
+ QUEUE_FLAG_NAME(POLL_STATS),
+ QUEUE_FLAG_NAME(REGISTERED),
+ QUEUE_FLAG_NAME(SCSI_PASSTHROUGH),
+ QUEUE_FLAG_NAME(QUIESCED),
+};
+#undef QUEUE_FLAG_NAME
+
+static int queue_state_show(void *data, struct seq_file *m)
+{
+ struct request_queue *q = data;
+
+ blk_flags_show(m, q->queue_flags, blk_queue_flag_name,
+ ARRAY_SIZE(blk_queue_flag_name));
+ seq_puts(m, "\n");
+ return 0;
+}
+
+static ssize_t queue_state_write(void *data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct request_queue *q = data;
+ char opbuf[16] = { }, *op;
+
+ /*
+ * The "state" attribute is removed after blk_cleanup_queue() has called
+ * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid
+ * triggering a use-after-free.
+ */
+ if (blk_queue_dead(q))
+ return -ENOENT;
+
+ if (count >= sizeof(opbuf)) {
+ pr_err("%s: operation too long\n", __func__);
+ goto inval;
+ }
+
+ if (copy_from_user(opbuf, buf, count))
+ return -EFAULT;
+ op = strstrip(opbuf);
+ if (strcmp(op, "run") == 0) {
+ blk_mq_run_hw_queues(q, true);
+ } else if (strcmp(op, "start") == 0) {
+ blk_mq_start_stopped_hw_queues(q, true);
+ } else if (strcmp(op, "kick") == 0) {
+ blk_mq_kick_requeue_list(q);
+ } else {
+ pr_err("%s: unsupported operation '%s'\n", __func__, op);
+inval:
+ pr_err("%s: use 'run', 'start' or 'kick'\n", __func__);
+ return -EINVAL;
+ }
+ return count;
+}
+
+static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
+{
+ if (stat->nr_samples) {
+ seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
+ stat->nr_samples, stat->mean, stat->min, stat->max);
+ } else {
+ seq_puts(m, "samples=0");
+ }
+}
+
+static int queue_write_hint_show(void *data, struct seq_file *m)
+{
+ struct request_queue *q = data;
+ int i;
+
+ for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
+ seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
+
+ return 0;
+}
+
+static ssize_t queue_write_hint_store(void *data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct request_queue *q = data;
+ int i;
+
+ for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
+ q->write_hints[i] = 0;
+
+ return count;
+}
+
+static int queue_poll_stat_show(void *data, struct seq_file *m)
+{
+ struct request_queue *q = data;
+ int bucket;
+
+ for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
+ seq_printf(m, "read (%d Bytes): ", 1 << (9+bucket));
+ print_stat(m, &q->poll_stat[2*bucket]);
+ seq_puts(m, "\n");
+
+ seq_printf(m, "write (%d Bytes): ", 1 << (9+bucket));
+ print_stat(m, &q->poll_stat[2*bucket+1]);
+ seq_puts(m, "\n");
+ }
+ return 0;
+}
+
+#define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
+static const char *const hctx_state_name[] = {
+ HCTX_STATE_NAME(STOPPED),
+ HCTX_STATE_NAME(TAG_ACTIVE),
+ HCTX_STATE_NAME(SCHED_RESTART),
+ HCTX_STATE_NAME(TAG_WAITING),
+ HCTX_STATE_NAME(START_ON_RUN),
+};
+#undef HCTX_STATE_NAME
+
+static int hctx_state_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ blk_flags_show(m, hctx->state, hctx_state_name,
+ ARRAY_SIZE(hctx_state_name));
+ seq_puts(m, "\n");
+ return 0;
+}
+
+#define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
+static const char *const alloc_policy_name[] = {
+ BLK_TAG_ALLOC_NAME(FIFO),
+ BLK_TAG_ALLOC_NAME(RR),
+};
+#undef BLK_TAG_ALLOC_NAME
+
+#define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
+static const char *const hctx_flag_name[] = {
+ HCTX_FLAG_NAME(SHOULD_MERGE),
+ HCTX_FLAG_NAME(TAG_SHARED),
+ HCTX_FLAG_NAME(SG_MERGE),
+ HCTX_FLAG_NAME(BLOCKING),
+ HCTX_FLAG_NAME(NO_SCHED),
+};
+#undef HCTX_FLAG_NAME
+
+static int hctx_flags_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
+
+ seq_puts(m, "alloc_policy=");
+ if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
+ alloc_policy_name[alloc_policy])
+ seq_puts(m, alloc_policy_name[alloc_policy]);
+ else
+ seq_printf(m, "%d", alloc_policy);
+ seq_puts(m, " ");
+ blk_flags_show(m,
+ hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
+ hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
+ seq_puts(m, "\n");
+ return 0;
+}
+
+#define REQ_OP_NAME(name) [REQ_OP_##name] = #name
+static const char *const op_name[] = {
+ REQ_OP_NAME(READ),
+ REQ_OP_NAME(WRITE),
+ REQ_OP_NAME(FLUSH),
+ REQ_OP_NAME(DISCARD),
+ REQ_OP_NAME(ZONE_REPORT),
+ REQ_OP_NAME(SECURE_ERASE),
+ REQ_OP_NAME(ZONE_RESET),
+ REQ_OP_NAME(WRITE_SAME),
+ REQ_OP_NAME(WRITE_ZEROES),
+ REQ_OP_NAME(SCSI_IN),
+ REQ_OP_NAME(SCSI_OUT),
+ REQ_OP_NAME(DRV_IN),
+ REQ_OP_NAME(DRV_OUT),
+};
+#undef REQ_OP_NAME
+
+#define CMD_FLAG_NAME(name) [__REQ_##name] = #name
+static const char *const cmd_flag_name[] = {
+ CMD_FLAG_NAME(FAILFAST_DEV),
+ CMD_FLAG_NAME(FAILFAST_TRANSPORT),
+ CMD_FLAG_NAME(FAILFAST_DRIVER),
+ CMD_FLAG_NAME(SYNC),
+ CMD_FLAG_NAME(META),
+ CMD_FLAG_NAME(PRIO),
+ CMD_FLAG_NAME(NOMERGE),
+ CMD_FLAG_NAME(IDLE),
+ CMD_FLAG_NAME(INTEGRITY),
+ CMD_FLAG_NAME(FUA),
+ CMD_FLAG_NAME(PREFLUSH),
+ CMD_FLAG_NAME(RAHEAD),
+ CMD_FLAG_NAME(BACKGROUND),
+ CMD_FLAG_NAME(NOUNMAP),
+ CMD_FLAG_NAME(NOWAIT),
+};
+#undef CMD_FLAG_NAME
+
+#define RQF_NAME(name) [ilog2((__force u32)RQF_##name)] = #name
+static const char *const rqf_name[] = {
+ RQF_NAME(SORTED),
+ RQF_NAME(STARTED),
+ RQF_NAME(QUEUED),
+ RQF_NAME(SOFTBARRIER),
+ RQF_NAME(FLUSH_SEQ),
+ RQF_NAME(MIXED_MERGE),
+ RQF_NAME(MQ_INFLIGHT),
+ RQF_NAME(DONTPREP),
+ RQF_NAME(PREEMPT),
+ RQF_NAME(COPY_USER),
+ RQF_NAME(FAILED),
+ RQF_NAME(QUIET),
+ RQF_NAME(ELVPRIV),
+ RQF_NAME(IO_STAT),
+ RQF_NAME(ALLOCED),
+ RQF_NAME(PM),
+ RQF_NAME(HASHED),
+ RQF_NAME(STATS),
+ RQF_NAME(SPECIAL_PAYLOAD),
+};
+#undef RQF_NAME
+
+#define RQAF_NAME(name) [REQ_ATOM_##name] = #name
+static const char *const rqaf_name[] = {
+ RQAF_NAME(COMPLETE),
+ RQAF_NAME(STARTED),
+ RQAF_NAME(POLL_SLEPT),
+};
+#undef RQAF_NAME
+
+int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
+{
+ const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
+ const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
+
+ seq_printf(m, "%p {.op=", rq);
+ if (op < ARRAY_SIZE(op_name) && op_name[op])
+ seq_printf(m, "%s", op_name[op]);
+ else
+ seq_printf(m, "%d", op);
+ seq_puts(m, ", .cmd_flags=");
+ blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
+ ARRAY_SIZE(cmd_flag_name));
+ seq_puts(m, ", .rq_flags=");
+ blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
+ ARRAY_SIZE(rqf_name));
+ seq_puts(m, ", .atomic_flags=");
+ blk_flags_show(m, rq->atomic_flags, rqaf_name, ARRAY_SIZE(rqaf_name));
+ seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
+ rq->internal_tag);
+ if (mq_ops->show_rq)
+ mq_ops->show_rq(m, rq);
+ seq_puts(m, "}\n");
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__blk_mq_debugfs_rq_show);
+
+int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
+{
+ return __blk_mq_debugfs_rq_show(m, list_entry_rq(v));
+}
+EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show);
+
+static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
+ __acquires(&q->requeue_lock)
+{
+ struct request_queue *q = m->private;
+
+ spin_lock_irq(&q->requeue_lock);
+ return seq_list_start(&q->requeue_list, *pos);
+}
+
+static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct request_queue *q = m->private;
+
+ return seq_list_next(v, &q->requeue_list, pos);
+}
+
+static void queue_requeue_list_stop(struct seq_file *m, void *v)
+ __releases(&q->requeue_lock)
+{
+ struct request_queue *q = m->private;
+
+ spin_unlock_irq(&q->requeue_lock);
+}
+
+static const struct seq_operations queue_requeue_list_seq_ops = {
+ .start = queue_requeue_list_start,
+ .next = queue_requeue_list_next,
+ .stop = queue_requeue_list_stop,
+ .show = blk_mq_debugfs_rq_show,
+};
+
+static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
+ __acquires(&hctx->lock)
+{
+ struct blk_mq_hw_ctx *hctx = m->private;
+
+ spin_lock(&hctx->lock);
+ return seq_list_start(&hctx->dispatch, *pos);
+}
+
+static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct blk_mq_hw_ctx *hctx = m->private;
+
+ return seq_list_next(v, &hctx->dispatch, pos);
+}
+
+static void hctx_dispatch_stop(struct seq_file *m, void *v)
+ __releases(&hctx->lock)
+{
+ struct blk_mq_hw_ctx *hctx = m->private;
+
+ spin_unlock(&hctx->lock);
+}
+
+static const struct seq_operations hctx_dispatch_seq_ops = {
+ .start = hctx_dispatch_start,
+ .next = hctx_dispatch_next,
+ .stop = hctx_dispatch_stop,
+ .show = blk_mq_debugfs_rq_show,
+};
+
+struct show_busy_params {
+ struct seq_file *m;
+ struct blk_mq_hw_ctx *hctx;
+};
+
+/*
+ * Note: the state of a request may change while this function is in progress,
+ * e.g. due to a concurrent blk_mq_finish_request() call.
+ */
+static void hctx_show_busy_rq(struct request *rq, void *data, bool reserved)
+{
+ const struct show_busy_params *params = data;
+
+ if (blk_mq_map_queue(rq->q, rq->mq_ctx->cpu) == params->hctx &&
+ test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
+ __blk_mq_debugfs_rq_show(params->m,
+ list_entry_rq(&rq->queuelist));
+}
+
+static int hctx_busy_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ struct show_busy_params params = { .m = m, .hctx = hctx };
+
+ blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq,
+ ¶ms);
+
+ return 0;
+}
+
+static int hctx_ctx_map_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ sbitmap_bitmap_show(&hctx->ctx_map, m);
+ return 0;
+}
+
+static void blk_mq_debugfs_tags_show(struct seq_file *m,
+ struct blk_mq_tags *tags)
+{
+ seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
+ seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
+ seq_printf(m, "active_queues=%d\n",
+ atomic_read(&tags->active_queues));
+
+ seq_puts(m, "\nbitmap_tags:\n");
+ sbitmap_queue_show(&tags->bitmap_tags, m);
+
+ if (tags->nr_reserved_tags) {
+ seq_puts(m, "\nbreserved_tags:\n");
+ sbitmap_queue_show(&tags->breserved_tags, m);
+ }
+}
+
+static int hctx_tags_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ struct request_queue *q = hctx->queue;
+ int res;
+
+ res = mutex_lock_interruptible(&q->sysfs_lock);
+ if (res)
+ goto out;
+ if (hctx->tags)
+ blk_mq_debugfs_tags_show(m, hctx->tags);
+ mutex_unlock(&q->sysfs_lock);
+
+out:
+ return res;
+}
+
+static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ struct request_queue *q = hctx->queue;
+ int res;
+
+ res = mutex_lock_interruptible(&q->sysfs_lock);
+ if (res)
+ goto out;
+ if (hctx->tags)
+ sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
+ mutex_unlock(&q->sysfs_lock);
+
+out:
+ return res;
+}
+
+static int hctx_sched_tags_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ struct request_queue *q = hctx->queue;
+ int res;
+
+ res = mutex_lock_interruptible(&q->sysfs_lock);
+ if (res)
+ goto out;
+ if (hctx->sched_tags)
+ blk_mq_debugfs_tags_show(m, hctx->sched_tags);
+ mutex_unlock(&q->sysfs_lock);
+
+out:
+ return res;
+}
+
+static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ struct request_queue *q = hctx->queue;
+ int res;
+
+ res = mutex_lock_interruptible(&q->sysfs_lock);
+ if (res)
+ goto out;
+ if (hctx->sched_tags)
+ sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
+ mutex_unlock(&q->sysfs_lock);
+
+out:
+ return res;
+}
+
+static int hctx_io_poll_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ seq_printf(m, "considered=%lu\n", hctx->poll_considered);
+ seq_printf(m, "invoked=%lu\n", hctx->poll_invoked);
+ seq_printf(m, "success=%lu\n", hctx->poll_success);
+ return 0;
+}
+
+static ssize_t hctx_io_poll_write(void *data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0;
+ return count;
+}
+
+static int hctx_dispatched_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ int i;
+
+ seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
+
+ for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
+ unsigned int d = 1U << (i - 1);
+
+ seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]);
+ }
+
+ seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]);
+ return 0;
+}
+
+static ssize_t hctx_dispatched_write(void *data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ int i;
+
+ for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++)
+ hctx->dispatched[i] = 0;
+ return count;
+}
+
+static int hctx_queued_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ seq_printf(m, "%lu\n", hctx->queued);
+ return 0;
+}
+
+static ssize_t hctx_queued_write(void *data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ hctx->queued = 0;
+ return count;
+}
+
+static int hctx_run_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ seq_printf(m, "%lu\n", hctx->run);
+ return 0;
+}
+
+static ssize_t hctx_run_write(void *data, const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ hctx->run = 0;
+ return count;
+}
+
+static int hctx_active_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ seq_printf(m, "%d\n", atomic_read(&hctx->nr_active));
+ return 0;
+}
+
+static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
+ __acquires(&ctx->lock)
+{
+ struct blk_mq_ctx *ctx = m->private;
+
+ spin_lock(&ctx->lock);
+ return seq_list_start(&ctx->rq_list, *pos);
+}
+
+static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct blk_mq_ctx *ctx = m->private;
+
+ return seq_list_next(v, &ctx->rq_list, pos);
+}
+
+static void ctx_rq_list_stop(struct seq_file *m, void *v)
+ __releases(&ctx->lock)
+{
+ struct blk_mq_ctx *ctx = m->private;
+
+ spin_unlock(&ctx->lock);
+}
+
+static const struct seq_operations ctx_rq_list_seq_ops = {
+ .start = ctx_rq_list_start,
+ .next = ctx_rq_list_next,
+ .stop = ctx_rq_list_stop,
+ .show = blk_mq_debugfs_rq_show,
+};
+static int ctx_dispatched_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_ctx *ctx = data;
+
+ seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);
+ return 0;
+}
+
+static ssize_t ctx_dispatched_write(void *data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct blk_mq_ctx *ctx = data;
+
+ ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;
+ return count;
+}
+
+static int ctx_merged_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_ctx *ctx = data;
+
+ seq_printf(m, "%lu\n", ctx->rq_merged);
+ return 0;
+}
+
+static ssize_t ctx_merged_write(void *data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct blk_mq_ctx *ctx = data;
+
+ ctx->rq_merged = 0;
+ return count;
+}
+
+static int ctx_completed_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_ctx *ctx = data;
+
+ seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);
+ return 0;
+}
+
+static ssize_t ctx_completed_write(void *data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct blk_mq_ctx *ctx = data;
+
+ ctx->rq_completed[0] = ctx->rq_completed[1] = 0;
+ return count;
+}
+
+static int blk_mq_debugfs_show(struct seq_file *m, void *v)
+{
+ const struct blk_mq_debugfs_attr *attr = m->private;
+ void *data = d_inode(m->file->f_path.dentry->d_parent)->i_private;
+
+ return attr->show(data, m);
+}
+
+static ssize_t blk_mq_debugfs_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct seq_file *m = file->private_data;
+ const struct blk_mq_debugfs_attr *attr = m->private;
+ void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
+
+ /*
+ * Attributes that only implement .seq_ops are read-only and 'attr' is
+ * the same with 'data' in this case.
+ */
+ if (attr == data || !attr->write)
+ return -EPERM;
+
+ return attr->write(data, buf, count, ppos);
+}
+
+static int blk_mq_debugfs_open(struct inode *inode, struct file *file)
+{
+ const struct blk_mq_debugfs_attr *attr = inode->i_private;
+ void *data = d_inode(file->f_path.dentry->d_parent)->i_private;
+ struct seq_file *m;
+ int ret;
+
+ if (attr->seq_ops) {
+ ret = seq_open(file, attr->seq_ops);
+ if (!ret) {
+ m = file->private_data;
+ m->private = data;
+ }
+ return ret;
+ }
+
+ if (WARN_ON_ONCE(!attr->show))
+ return -EPERM;
+
+ return single_open(file, blk_mq_debugfs_show, inode->i_private);
+}
+
+static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
+{
+ const struct blk_mq_debugfs_attr *attr = inode->i_private;
+
+ if (attr->show)
+ return single_release(inode, file);
+ else
+ return seq_release(inode, file);
+}
+
+static const struct file_operations blk_mq_debugfs_fops = {
+ .open = blk_mq_debugfs_open,
+ .read = seq_read,
+ .write = blk_mq_debugfs_write,
+ .llseek = seq_lseek,
+ .release = blk_mq_debugfs_release,
+};
+
+static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
+ {"poll_stat", 0400, queue_poll_stat_show},
+ {"requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops},
+ {"state", 0600, queue_state_show, queue_state_write},
+ {"write_hints", 0600, queue_write_hint_show, queue_write_hint_store},
+ {},
+};
+
+static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
+ {"state", 0400, hctx_state_show},
+ {"flags", 0400, hctx_flags_show},
+ {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops},
+ {"busy", 0400, hctx_busy_show},
+ {"ctx_map", 0400, hctx_ctx_map_show},
+ {"tags", 0400, hctx_tags_show},
+ {"tags_bitmap", 0400, hctx_tags_bitmap_show},
+ {"sched_tags", 0400, hctx_sched_tags_show},
+ {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show},
+ {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write},
+ {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write},
+ {"queued", 0600, hctx_queued_show, hctx_queued_write},
+ {"run", 0600, hctx_run_show, hctx_run_write},
+ {"active", 0400, hctx_active_show},
+ {},
+};
+
+static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
+ {"rq_list", 0400, .seq_ops = &ctx_rq_list_seq_ops},
+ {"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},
+ {"merged", 0600, ctx_merged_show, ctx_merged_write},
+ {"completed", 0600, ctx_completed_show, ctx_completed_write},
+ {},
+};
+
+static bool debugfs_create_files(struct dentry *parent, void *data,
+ const struct blk_mq_debugfs_attr *attr)
+{
+ d_inode(parent)->i_private = data;
+
+ for (; attr->name; attr++) {
+ if (!debugfs_create_file(attr->name, attr->mode, parent,
+ (void *)attr, &blk_mq_debugfs_fops))
+ return false;
+ }
+ return true;
+}
+
+int blk_mq_debugfs_register(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ if (!blk_debugfs_root)
+ return -ENOENT;
+
+ q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
+ blk_debugfs_root);
+ if (!q->debugfs_dir)
+ return -ENOMEM;
+
+ if (!debugfs_create_files(q->debugfs_dir, q,
+ blk_mq_debugfs_queue_attrs))
+ goto err;
+
+ /*
+ * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
+ * didn't exist yet (because we don't know what to name the directory
+ * until the queue is registered to a gendisk).
+ */
+ if (q->elevator && !q->sched_debugfs_dir)
+ blk_mq_debugfs_register_sched(q);
+
+ /* Similarly, blk_mq_init_hctx() couldn't do this previously. */
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))
+ goto err;
+ if (q->elevator && !hctx->sched_debugfs_dir &&
+ blk_mq_debugfs_register_sched_hctx(q, hctx))
+ goto err;
+ }
+
+ return 0;
+
+err:
+ blk_mq_debugfs_unregister(q);
+ return -ENOMEM;
+}
+
+void blk_mq_debugfs_unregister(struct request_queue *q)
+{
+ debugfs_remove_recursive(q->debugfs_dir);
+ q->sched_debugfs_dir = NULL;
+ q->debugfs_dir = NULL;
+}
+
+static int blk_mq_debugfs_register_ctx(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *ctx)
+{
+ struct dentry *ctx_dir;
+ char name[20];
+
+ snprintf(name, sizeof(name), "cpu%u", ctx->cpu);
+ ctx_dir = debugfs_create_dir(name, hctx->debugfs_dir);
+ if (!ctx_dir)
+ return -ENOMEM;
+
+ if (!debugfs_create_files(ctx_dir, ctx, blk_mq_debugfs_ctx_attrs))
+ return -ENOMEM;
+
+ return 0;
+}
+
+int blk_mq_debugfs_register_hctx(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx)
+{
+ struct blk_mq_ctx *ctx;
+ char name[20];
+ int i;
+
+ if (!q->debugfs_dir)
+ return -ENOENT;
+
+ snprintf(name, sizeof(name), "hctx%u", hctx->queue_num);
+ hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir);
+ if (!hctx->debugfs_dir)
+ return -ENOMEM;
+
+ if (!debugfs_create_files(hctx->debugfs_dir, hctx,
+ blk_mq_debugfs_hctx_attrs))
+ goto err;
+
+ hctx_for_each_ctx(hctx, ctx, i) {
+ if (blk_mq_debugfs_register_ctx(hctx, ctx))
+ goto err;
+ }
+
+ return 0;
+
+err:
+ blk_mq_debugfs_unregister_hctx(hctx);
+ return -ENOMEM;
+}
+
+void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ debugfs_remove_recursive(hctx->debugfs_dir);
+ hctx->sched_debugfs_dir = NULL;
+ hctx->debugfs_dir = NULL;
+}
+
+int blk_mq_debugfs_register_hctxs(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (blk_mq_debugfs_register_hctx(q, hctx))
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_debugfs_unregister_hctx(hctx);
+}
+
+int blk_mq_debugfs_register_sched(struct request_queue *q)
+{
+ struct elevator_type *e = q->elevator->type;
+
+ if (!q->debugfs_dir)
+ return -ENOENT;
+
+ if (!e->queue_debugfs_attrs)
+ return 0;
+
+ q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);
+ if (!q->sched_debugfs_dir)
+ return -ENOMEM;
+
+ if (!debugfs_create_files(q->sched_debugfs_dir, q,
+ e->queue_debugfs_attrs))
+ goto err;
+
+ return 0;
+
+err:
+ blk_mq_debugfs_unregister_sched(q);
+ return -ENOMEM;
+}
+
+void blk_mq_debugfs_unregister_sched(struct request_queue *q)
+{
+ debugfs_remove_recursive(q->sched_debugfs_dir);
+ q->sched_debugfs_dir = NULL;
+}
+
+int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx)
+{
+ struct elevator_type *e = q->elevator->type;
+
+ if (!hctx->debugfs_dir)
+ return -ENOENT;
+
+ if (!e->hctx_debugfs_attrs)
+ return 0;
+
+ hctx->sched_debugfs_dir = debugfs_create_dir("sched",
+ hctx->debugfs_dir);
+ if (!hctx->sched_debugfs_dir)
+ return -ENOMEM;
+
+ if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,
+ e->hctx_debugfs_attrs))
+ return -ENOMEM;
+
+ return 0;
+}
+
+void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ debugfs_remove_recursive(hctx->sched_debugfs_dir);
+ hctx->sched_debugfs_dir = NULL;
+}
diff --git a/src/kernel/linux/v4.14/block/blk-mq-debugfs.h b/src/kernel/linux/v4.14/block/blk-mq-debugfs.h
new file mode 100644
index 0000000..b9d366e
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-debugfs.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef INT_BLK_MQ_DEBUGFS_H
+#define INT_BLK_MQ_DEBUGFS_H
+
+#ifdef CONFIG_BLK_DEBUG_FS
+
+#include <linux/seq_file.h>
+
+struct blk_mq_debugfs_attr {
+ const char *name;
+ umode_t mode;
+ int (*show)(void *, struct seq_file *);
+ ssize_t (*write)(void *, const char __user *, size_t, loff_t *);
+ /* Set either .show or .seq_ops. */
+ const struct seq_operations *seq_ops;
+};
+
+int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq);
+int blk_mq_debugfs_rq_show(struct seq_file *m, void *v);
+
+int blk_mq_debugfs_register(struct request_queue *q);
+void blk_mq_debugfs_unregister(struct request_queue *q);
+int blk_mq_debugfs_register_hctx(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx);
+void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx);
+int blk_mq_debugfs_register_hctxs(struct request_queue *q);
+void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);
+
+int blk_mq_debugfs_register_sched(struct request_queue *q);
+void blk_mq_debugfs_unregister_sched(struct request_queue *q);
+int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx);
+void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);
+#else
+static inline int blk_mq_debugfs_register(struct request_queue *q)
+{
+ return 0;
+}
+
+static inline void blk_mq_debugfs_unregister(struct request_queue *q)
+{
+}
+
+static inline int blk_mq_debugfs_register_hctx(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx)
+{
+ return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
+{
+}
+
+static inline int blk_mq_debugfs_register_hctxs(struct request_queue *q)
+{
+ return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
+{
+}
+
+static inline int blk_mq_debugfs_register_sched(struct request_queue *q)
+{
+ return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_sched(struct request_queue *q)
+{
+}
+
+static inline int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx)
+{
+ return 0;
+}
+
+static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
+{
+}
+#endif
+
+#endif
diff --git a/src/kernel/linux/v4.14/block/blk-mq-pci.c b/src/kernel/linux/v4.14/block/blk-mq-pci.c
new file mode 100644
index 0000000..76944e3
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-pci.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2016 Christoph Hellwig.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#include <linux/kobject.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/blk-mq-pci.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+
+/**
+ * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
+ * @set: tagset to provide the mapping for
+ * @pdev: PCI device associated with @set.
+ *
+ * This function assumes the PCI device @pdev has at least as many available
+ * interrupt vectors as @set has queues. It will then query the vector
+ * corresponding to each queue for it's affinity mask and built queue mapping
+ * that maps a queue to the CPUs that have irq affinity for the corresponding
+ * vector.
+ */
+int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev)
+{
+ const struct cpumask *mask;
+ unsigned int queue, cpu;
+
+ for (queue = 0; queue < set->nr_hw_queues; queue++) {
+ mask = pci_irq_get_affinity(pdev, queue);
+ if (!mask)
+ goto fallback;
+
+ for_each_cpu(cpu, mask)
+ set->mq_map[cpu] = queue;
+ }
+
+ return 0;
+
+fallback:
+ WARN_ON_ONCE(set->nr_hw_queues > 1);
+ for_each_possible_cpu(cpu)
+ set->mq_map[cpu] = 0;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);
diff --git a/src/kernel/linux/v4.14/block/blk-mq-rdma.c b/src/kernel/linux/v4.14/block/blk-mq-rdma.c
new file mode 100644
index 0000000..996167f
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-rdma.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2017 Sagi Grimberg.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#include <linux/blk-mq.h>
+#include <linux/blk-mq-rdma.h>
+#include <rdma/ib_verbs.h>
+
+/**
+ * blk_mq_rdma_map_queues - provide a default queue mapping for rdma device
+ * @set: tagset to provide the mapping for
+ * @dev: rdma device associated with @set.
+ * @first_vec: first interrupt vectors to use for queues (usually 0)
+ *
+ * This function assumes the rdma device @dev has at least as many available
+ * interrupt vetors as @set has queues. It will then query it's affinity mask
+ * and built queue mapping that maps a queue to the CPUs that have irq affinity
+ * for the corresponding vector.
+ *
+ * In case either the driver passed a @dev with less vectors than
+ * @set->nr_hw_queues, or @dev does not provide an affinity mask for a
+ * vector, we fallback to the naive mapping.
+ */
+int blk_mq_rdma_map_queues(struct blk_mq_tag_set *set,
+ struct ib_device *dev, int first_vec)
+{
+ const struct cpumask *mask;
+ unsigned int queue, cpu;
+
+ for (queue = 0; queue < set->nr_hw_queues; queue++) {
+ mask = ib_get_vector_affinity(dev, first_vec + queue);
+ if (!mask)
+ goto fallback;
+
+ for_each_cpu(cpu, mask)
+ set->mq_map[cpu] = queue;
+ }
+
+ return 0;
+
+fallback:
+ return blk_mq_map_queues(set);
+}
+EXPORT_SYMBOL_GPL(blk_mq_rdma_map_queues);
diff --git a/src/kernel/linux/v4.14/block/blk-mq-sched.c b/src/kernel/linux/v4.14/block/blk-mq-sched.c
new file mode 100644
index 0000000..ae5d8f1
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-sched.c
@@ -0,0 +1,587 @@
+/*
+ * blk-mq scheduling framework
+ *
+ * Copyright (C) 2016 Jens Axboe
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/blk-mq.h>
+
+#include <trace/events/block.h>
+
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-debugfs.h"
+#include "blk-mq-sched.h"
+#include "blk-mq-tag.h"
+#include "blk-wbt.h"
+
+void blk_mq_sched_free_hctx_data(struct request_queue *q,
+ void (*exit)(struct blk_mq_hw_ctx *))
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (exit && hctx->sched_data)
+ exit(hctx);
+ kfree(hctx->sched_data);
+ hctx->sched_data = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data);
+
+void blk_mq_sched_assign_ioc(struct request *rq, struct bio *bio)
+{
+ struct request_queue *q = rq->q;
+ struct io_context *ioc = rq_ioc(bio);
+ struct io_cq *icq;
+
+ spin_lock_irq(q->queue_lock);
+ icq = ioc_lookup_icq(ioc, q);
+ spin_unlock_irq(q->queue_lock);
+
+ if (!icq) {
+ icq = ioc_create_icq(ioc, q, GFP_ATOMIC);
+ if (!icq)
+ return;
+ }
+ get_io_context(icq->ioc);
+ rq->elv.icq = icq;
+}
+
+/*
+ * Mark a hardware queue as needing a restart. For shared queues, maintain
+ * a count of how many hardware queues are marked for restart.
+ */
+static void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ return;
+
+ if (hctx->flags & BLK_MQ_F_TAG_SHARED) {
+ struct request_queue *q = hctx->queue;
+
+ if (!test_and_set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_inc(&q->shared_hctx_restart);
+ } else
+ set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+}
+
+static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ return false;
+
+ if (hctx->flags & BLK_MQ_F_TAG_SHARED) {
+ struct request_queue *q = hctx->queue;
+
+ if (test_and_clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_dec(&q->shared_hctx_restart);
+ } else
+ clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+
+ if (blk_mq_hctx_has_pending(hctx)) {
+ blk_mq_run_hw_queue(hctx, true);
+ return true;
+ }
+
+ return false;
+}
+
+void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
+{
+ struct request_queue *q = hctx->queue;
+ struct elevator_queue *e = q->elevator;
+ const bool has_sched_dispatch = e && e->type->ops.mq.dispatch_request;
+ bool do_sched_dispatch = true;
+ LIST_HEAD(rq_list);
+
+ /* RCU or SRCU read lock is needed before checking quiesced flag */
+ if (unlikely(blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)))
+ return;
+
+ hctx->run++;
+
+ /*
+ * If we have previous entries on our dispatch list, grab them first for
+ * more fair dispatch.
+ */
+ if (!list_empty_careful(&hctx->dispatch)) {
+ spin_lock(&hctx->lock);
+ if (!list_empty(&hctx->dispatch))
+ list_splice_init(&hctx->dispatch, &rq_list);
+ spin_unlock(&hctx->lock);
+ }
+
+ /*
+ * Only ask the scheduler for requests, if we didn't have residual
+ * requests from the dispatch list. This is to avoid the case where
+ * we only ever dispatch a fraction of the requests available because
+ * of low device queue depth. Once we pull requests out of the IO
+ * scheduler, we can no longer merge or sort them. So it's best to
+ * leave them there for as long as we can. Mark the hw queue as
+ * needing a restart in that case.
+ */
+ if (!list_empty(&rq_list)) {
+ blk_mq_sched_mark_restart_hctx(hctx);
+ do_sched_dispatch = blk_mq_dispatch_rq_list(q, &rq_list);
+ } else if (!has_sched_dispatch) {
+ blk_mq_flush_busy_ctxs(hctx, &rq_list);
+ blk_mq_dispatch_rq_list(q, &rq_list);
+ }
+
+ /*
+ * We want to dispatch from the scheduler if there was nothing
+ * on the dispatch list or we were able to dispatch from the
+ * dispatch list.
+ */
+ if (do_sched_dispatch && has_sched_dispatch) {
+ do {
+ struct request *rq;
+
+ rq = e->type->ops.mq.dispatch_request(hctx);
+ if (!rq)
+ break;
+ list_add(&rq->queuelist, &rq_list);
+ } while (blk_mq_dispatch_rq_list(q, &rq_list));
+ }
+}
+
+bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
+ struct request **merged_request)
+{
+ struct request *rq;
+
+ switch (elv_merge(q, &rq, bio)) {
+ case ELEVATOR_BACK_MERGE:
+ if (!blk_mq_sched_allow_merge(q, rq, bio))
+ return false;
+ if (!bio_attempt_back_merge(q, rq, bio))
+ return false;
+ *merged_request = attempt_back_merge(q, rq);
+ if (!*merged_request)
+ elv_merged_request(q, rq, ELEVATOR_BACK_MERGE);
+ return true;
+ case ELEVATOR_FRONT_MERGE:
+ if (!blk_mq_sched_allow_merge(q, rq, bio))
+ return false;
+ if (!bio_attempt_front_merge(q, rq, bio))
+ return false;
+ *merged_request = attempt_front_merge(q, rq);
+ if (!*merged_request)
+ elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE);
+ return true;
+ default:
+ return false;
+ }
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge);
+
+/*
+ * Reverse check our software queue for entries that we could potentially
+ * merge with. Currently includes a hand-wavy stop count of 8, to not spend
+ * too much time checking for merges.
+ */
+static bool blk_mq_attempt_merge(struct request_queue *q,
+ struct blk_mq_ctx *ctx, struct bio *bio)
+{
+ struct request *rq;
+ int checked = 8;
+
+ lockdep_assert_held(&ctx->lock);
+
+ list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
+ bool merged = false;
+
+ if (!checked--)
+ break;
+
+ if (!blk_rq_merge_ok(rq, bio))
+ continue;
+
+ switch (blk_try_merge(rq, bio)) {
+ case ELEVATOR_BACK_MERGE:
+ if (blk_mq_sched_allow_merge(q, rq, bio))
+ merged = bio_attempt_back_merge(q, rq, bio);
+ break;
+ case ELEVATOR_FRONT_MERGE:
+ if (blk_mq_sched_allow_merge(q, rq, bio))
+ merged = bio_attempt_front_merge(q, rq, bio);
+ break;
+ case ELEVATOR_DISCARD_MERGE:
+ merged = bio_attempt_discard_merge(q, rq, bio);
+ break;
+ default:
+ continue;
+ }
+
+ if (merged)
+ ctx->rq_merged++;
+ return merged;
+ }
+
+ return false;
+}
+
+bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
+{
+ struct elevator_queue *e = q->elevator;
+ struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
+ bool ret = false;
+
+ if (e && e->type->ops.mq.bio_merge) {
+ blk_mq_put_ctx(ctx);
+ return e->type->ops.mq.bio_merge(hctx, bio);
+ }
+
+ if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
+ !list_empty_careful(&ctx->rq_list)) {
+ /* default per sw-queue merge */
+ spin_lock(&ctx->lock);
+ ret = blk_mq_attempt_merge(q, ctx, bio);
+ spin_unlock(&ctx->lock);
+ }
+
+ blk_mq_put_ctx(ctx);
+ return ret;
+}
+
+bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq)
+{
+ return rq_mergeable(rq) && elv_attempt_insert_merge(q, rq);
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge);
+
+void blk_mq_sched_request_inserted(struct request *rq)
+{
+ trace_block_rq_insert(rq->q, rq);
+}
+EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted);
+
+static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx,
+ struct request *rq)
+{
+ if (rq->tag == -1) {
+ rq->rq_flags |= RQF_SORTED;
+ return false;
+ }
+
+ /*
+ * If we already have a real request tag, send directly to
+ * the dispatch list.
+ */
+ spin_lock(&hctx->lock);
+ list_add(&rq->queuelist, &hctx->dispatch);
+ spin_unlock(&hctx->lock);
+ return true;
+}
+
+/**
+ * list_for_each_entry_rcu_rr - iterate in a round-robin fashion over rcu list
+ * @pos: loop cursor.
+ * @skip: the list element that will not be examined. Iteration starts at
+ * @skip->next.
+ * @head: head of the list to examine. This list must have at least one
+ * element, namely @skip.
+ * @member: name of the list_head structure within typeof(*pos).
+ */
+#define list_for_each_entry_rcu_rr(pos, skip, head, member) \
+ for ((pos) = (skip); \
+ (pos = (pos)->member.next != (head) ? list_entry_rcu( \
+ (pos)->member.next, typeof(*pos), member) : \
+ list_entry_rcu((pos)->member.next->next, typeof(*pos), member)), \
+ (pos) != (skip); )
+
+/*
+ * Called after a driver tag has been freed to check whether a hctx needs to
+ * be restarted. Restarts @hctx if its tag set is not shared. Restarts hardware
+ * queues in a round-robin fashion if the tag set of @hctx is shared with other
+ * hardware queues.
+ */
+void blk_mq_sched_restart(struct blk_mq_hw_ctx *const hctx)
+{
+ struct blk_mq_tags *const tags = hctx->tags;
+ struct blk_mq_tag_set *const set = hctx->queue->tag_set;
+ struct request_queue *const queue = hctx->queue, *q;
+ struct blk_mq_hw_ctx *hctx2;
+ unsigned int i, j;
+
+ if (set->flags & BLK_MQ_F_TAG_SHARED) {
+ /*
+ * If this is 0, then we know that no hardware queues
+ * have RESTART marked. We're done.
+ */
+ if (!atomic_read(&queue->shared_hctx_restart))
+ return;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu_rr(q, queue, &set->tag_list,
+ tag_set_list) {
+ queue_for_each_hw_ctx(q, hctx2, i)
+ if (hctx2->tags == tags &&
+ blk_mq_sched_restart_hctx(hctx2))
+ goto done;
+ }
+ j = hctx->queue_num + 1;
+ for (i = 0; i < queue->nr_hw_queues; i++, j++) {
+ if (j == queue->nr_hw_queues)
+ j = 0;
+ hctx2 = queue->queue_hw_ctx[j];
+ if (hctx2->tags == tags &&
+ blk_mq_sched_restart_hctx(hctx2))
+ break;
+ }
+done:
+ rcu_read_unlock();
+ } else {
+ blk_mq_sched_restart_hctx(hctx);
+ }
+}
+
+/*
+ * Add flush/fua to the queue. If we fail getting a driver tag, then
+ * punt to the requeue list. Requeue will re-invoke us from a context
+ * that's safe to block from.
+ */
+static void blk_mq_sched_insert_flush(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, bool can_block)
+{
+ if (blk_mq_get_driver_tag(rq, &hctx, can_block)) {
+ blk_insert_flush(rq);
+ blk_mq_run_hw_queue(hctx, true);
+ } else
+ blk_mq_add_to_requeue_list(rq, false, true);
+}
+
+void blk_mq_sched_insert_request(struct request *rq, bool at_head,
+ bool run_queue, bool async, bool can_block)
+{
+ struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
+
+ if (rq->tag == -1 && op_is_flush(rq->cmd_flags)) {
+ blk_mq_sched_insert_flush(hctx, rq, can_block);
+ return;
+ }
+
+ if (e && blk_mq_sched_bypass_insert(hctx, rq))
+ goto run;
+
+ if (e && e->type->ops.mq.insert_requests) {
+ LIST_HEAD(list);
+
+ list_add(&rq->queuelist, &list);
+ e->type->ops.mq.insert_requests(hctx, &list, at_head);
+ } else {
+ spin_lock(&ctx->lock);
+ __blk_mq_insert_request(hctx, rq, at_head);
+ spin_unlock(&ctx->lock);
+ }
+
+run:
+ if (run_queue)
+ blk_mq_run_hw_queue(hctx, async);
+}
+
+void blk_mq_sched_insert_requests(struct request_queue *q,
+ struct blk_mq_ctx *ctx,
+ struct list_head *list, bool run_queue_async)
+{
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
+ struct elevator_queue *e = hctx->queue->elevator;
+
+ if (e) {
+ struct request *rq, *next;
+
+ /*
+ * We bypass requests that already have a driver tag assigned,
+ * which should only be flushes. Flushes are only ever inserted
+ * as single requests, so we shouldn't ever hit the
+ * WARN_ON_ONCE() below (but let's handle it just in case).
+ */
+ list_for_each_entry_safe(rq, next, list, queuelist) {
+ if (WARN_ON_ONCE(rq->tag != -1)) {
+ list_del_init(&rq->queuelist);
+ blk_mq_sched_bypass_insert(hctx, rq);
+ }
+ }
+ }
+
+ if (e && e->type->ops.mq.insert_requests)
+ e->type->ops.mq.insert_requests(hctx, list, false);
+ else
+ blk_mq_insert_requests(hctx, ctx, list);
+
+ blk_mq_run_hw_queue(hctx, run_queue_async);
+}
+
+static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set,
+ struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx)
+{
+ if (hctx->sched_tags) {
+ blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx);
+ blk_mq_free_rq_map(hctx->sched_tags);
+ hctx->sched_tags = NULL;
+ }
+}
+
+static int blk_mq_sched_alloc_tags(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx)
+{
+ struct blk_mq_tag_set *set = q->tag_set;
+ int ret;
+
+ hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests,
+ set->reserved_tags);
+ if (!hctx->sched_tags)
+ return -ENOMEM;
+
+ ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests);
+ if (ret)
+ blk_mq_sched_free_tags(set, hctx, hctx_idx);
+
+ return ret;
+}
+
+static void blk_mq_sched_tags_teardown(struct request_queue *q)
+{
+ struct blk_mq_tag_set *set = q->tag_set;
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_sched_free_tags(set, hctx, i);
+}
+
+int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx)
+{
+ struct elevator_queue *e = q->elevator;
+ int ret;
+
+ if (!e)
+ return 0;
+
+ ret = blk_mq_sched_alloc_tags(q, hctx, hctx_idx);
+ if (ret)
+ return ret;
+
+ if (e->type->ops.mq.init_hctx) {
+ ret = e->type->ops.mq.init_hctx(hctx, hctx_idx);
+ if (ret) {
+ blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx);
+ return ret;
+ }
+ }
+
+ blk_mq_debugfs_register_sched_hctx(q, hctx);
+
+ return 0;
+}
+
+void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (!e)
+ return;
+
+ blk_mq_debugfs_unregister_sched_hctx(hctx);
+
+ if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
+ e->type->ops.mq.exit_hctx(hctx, hctx_idx);
+ hctx->sched_data = NULL;
+ }
+
+ blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx);
+}
+
+int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
+{
+ struct blk_mq_hw_ctx *hctx;
+ struct elevator_queue *eq;
+ unsigned int i;
+ int ret;
+
+ if (!e) {
+ q->elevator = NULL;
+ return 0;
+ }
+
+ /*
+ * Default to double of smaller one between hw queue_depth and 128,
+ * since we don't split into sync/async like the old code did.
+ * Additionally, this is a per-hw queue depth.
+ */
+ q->nr_requests = 2 * min_t(unsigned int, q->tag_set->queue_depth,
+ BLKDEV_MAX_RQ);
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ ret = blk_mq_sched_alloc_tags(q, hctx, i);
+ if (ret)
+ goto err;
+ }
+
+ ret = e->ops.mq.init_sched(q, e);
+ if (ret)
+ goto err;
+
+ blk_mq_debugfs_register_sched(q);
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (e->ops.mq.init_hctx) {
+ ret = e->ops.mq.init_hctx(hctx, i);
+ if (ret) {
+ eq = q->elevator;
+ blk_mq_exit_sched(q, eq);
+ kobject_put(&eq->kobj);
+ return ret;
+ }
+ }
+ blk_mq_debugfs_register_sched_hctx(q, hctx);
+ }
+
+ return 0;
+
+err:
+ blk_mq_sched_tags_teardown(q);
+ q->elevator = NULL;
+ return ret;
+}
+
+void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ blk_mq_debugfs_unregister_sched_hctx(hctx);
+ if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
+ e->type->ops.mq.exit_hctx(hctx, i);
+ hctx->sched_data = NULL;
+ }
+ }
+ blk_mq_debugfs_unregister_sched(q);
+ if (e->type->ops.mq.exit_sched)
+ e->type->ops.mq.exit_sched(e);
+ blk_mq_sched_tags_teardown(q);
+ q->elevator = NULL;
+}
+
+int blk_mq_sched_init(struct request_queue *q)
+{
+ int ret;
+
+ mutex_lock(&q->sysfs_lock);
+ ret = elevator_init(q, NULL);
+ mutex_unlock(&q->sysfs_lock);
+
+ return ret;
+}
diff --git a/src/kernel/linux/v4.14/block/blk-mq-sched.h b/src/kernel/linux/v4.14/block/blk-mq-sched.h
new file mode 100644
index 0000000..ba1d141
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-sched.h
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BLK_MQ_SCHED_H
+#define BLK_MQ_SCHED_H
+
+#include "blk-mq.h"
+#include "blk-mq-tag.h"
+
+void blk_mq_sched_free_hctx_data(struct request_queue *q,
+ void (*exit)(struct blk_mq_hw_ctx *));
+
+void blk_mq_sched_assign_ioc(struct request *rq, struct bio *bio);
+
+void blk_mq_sched_request_inserted(struct request *rq);
+bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
+ struct request **merged_request);
+bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio);
+bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq);
+void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx);
+
+void blk_mq_sched_insert_request(struct request *rq, bool at_head,
+ bool run_queue, bool async, bool can_block);
+void blk_mq_sched_insert_requests(struct request_queue *q,
+ struct blk_mq_ctx *ctx,
+ struct list_head *list, bool run_queue_async);
+
+void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx);
+
+int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e);
+void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e);
+
+int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx);
+void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx);
+
+int blk_mq_sched_init(struct request_queue *q);
+
+static inline bool
+blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
+{
+ if (blk_queue_nomerges(q) || !bio_mergeable(bio))
+ return false;
+
+ return __blk_mq_sched_bio_merge(q, bio);
+}
+
+static inline bool
+blk_mq_sched_allow_merge(struct request_queue *q, struct request *rq,
+ struct bio *bio)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (e && e->type->ops.mq.allow_merge)
+ return e->type->ops.mq.allow_merge(q, rq, bio);
+
+ return true;
+}
+
+static inline void blk_mq_sched_completed_request(struct request *rq)
+{
+ struct elevator_queue *e = rq->q->elevator;
+
+ if (e && e->type->ops.mq.completed_request)
+ e->type->ops.mq.completed_request(rq);
+}
+
+static inline void blk_mq_sched_started_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+
+ if (e && e->type->ops.mq.started_request)
+ e->type->ops.mq.started_request(rq);
+}
+
+static inline void blk_mq_sched_requeue_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+
+ if (e && e->type->ops.mq.requeue_request)
+ e->type->ops.mq.requeue_request(rq);
+}
+
+static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx)
+{
+ struct elevator_queue *e = hctx->queue->elevator;
+
+ if (e && e->type->ops.mq.has_work)
+ return e->type->ops.mq.has_work(hctx);
+
+ return false;
+}
+
+static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx)
+{
+ return test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+}
+
+#endif
diff --git a/src/kernel/linux/v4.14/block/blk-mq-sysfs.c b/src/kernel/linux/v4.14/block/blk-mq-sysfs.c
new file mode 100644
index 0000000..c97fafa
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-sysfs.c
@@ -0,0 +1,392 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/backing-dev.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/smp.h>
+
+#include <linux/blk-mq.h>
+#include "blk-mq.h"
+#include "blk-mq-tag.h"
+
+static void blk_mq_sysfs_release(struct kobject *kobj)
+{
+}
+
+static void blk_mq_hw_sysfs_release(struct kobject *kobj)
+{
+ struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx,
+ kobj);
+ free_cpumask_var(hctx->cpumask);
+ kfree(hctx->ctxs);
+ kfree(hctx);
+}
+
+struct blk_mq_ctx_sysfs_entry {
+ struct attribute attr;
+ ssize_t (*show)(struct blk_mq_ctx *, char *);
+ ssize_t (*store)(struct blk_mq_ctx *, const char *, size_t);
+};
+
+struct blk_mq_hw_ctx_sysfs_entry {
+ struct attribute attr;
+ ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
+ ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
+};
+
+static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
+ char *page)
+{
+ struct blk_mq_ctx_sysfs_entry *entry;
+ struct blk_mq_ctx *ctx;
+ struct request_queue *q;
+ ssize_t res;
+
+ entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
+ ctx = container_of(kobj, struct blk_mq_ctx, kobj);
+ q = ctx->queue;
+
+ if (!entry->show)
+ return -EIO;
+
+ res = -ENOENT;
+ mutex_lock(&q->sysfs_lock);
+ if (!blk_queue_dying(q))
+ res = entry->show(ctx, page);
+ mutex_unlock(&q->sysfs_lock);
+ return res;
+}
+
+static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
+ const char *page, size_t length)
+{
+ struct blk_mq_ctx_sysfs_entry *entry;
+ struct blk_mq_ctx *ctx;
+ struct request_queue *q;
+ ssize_t res;
+
+ entry = container_of(attr, struct blk_mq_ctx_sysfs_entry, attr);
+ ctx = container_of(kobj, struct blk_mq_ctx, kobj);
+ q = ctx->queue;
+
+ if (!entry->store)
+ return -EIO;
+
+ res = -ENOENT;
+ mutex_lock(&q->sysfs_lock);
+ if (!blk_queue_dying(q))
+ res = entry->store(ctx, page, length);
+ mutex_unlock(&q->sysfs_lock);
+ return res;
+}
+
+static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
+ struct attribute *attr, char *page)
+{
+ struct blk_mq_hw_ctx_sysfs_entry *entry;
+ struct blk_mq_hw_ctx *hctx;
+ struct request_queue *q;
+ ssize_t res;
+
+ entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
+ hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
+ q = hctx->queue;
+
+ if (!entry->show)
+ return -EIO;
+
+ res = -ENOENT;
+ mutex_lock(&q->sysfs_lock);
+ if (!blk_queue_dying(q))
+ res = entry->show(hctx, page);
+ mutex_unlock(&q->sysfs_lock);
+ return res;
+}
+
+static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
+ struct attribute *attr, const char *page,
+ size_t length)
+{
+ struct blk_mq_hw_ctx_sysfs_entry *entry;
+ struct blk_mq_hw_ctx *hctx;
+ struct request_queue *q;
+ ssize_t res;
+
+ entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
+ hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
+ q = hctx->queue;
+
+ if (!entry->store)
+ return -EIO;
+
+ res = -ENOENT;
+ mutex_lock(&q->sysfs_lock);
+ if (!blk_queue_dying(q))
+ res = entry->store(hctx, page, length);
+ mutex_unlock(&q->sysfs_lock);
+ return res;
+}
+
+static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
+ char *page)
+{
+ return sprintf(page, "%u\n", hctx->tags->nr_tags);
+}
+
+static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx,
+ char *page)
+{
+ return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags);
+}
+
+static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
+{
+ const size_t size = PAGE_SIZE - 1;
+ unsigned int i, first = 1;
+ int ret = 0, pos = 0;
+
+ for_each_cpu(i, hctx->cpumask) {
+ if (first)
+ ret = snprintf(pos + page, size - pos, "%u", i);
+ else
+ ret = snprintf(pos + page, size - pos, ", %u", i);
+
+ if (ret >= size - pos)
+ break;
+
+ first = 0;
+ pos += ret;
+ }
+
+ ret = snprintf(pos + page, size + 1 - pos, "\n");
+ return pos + ret;
+}
+
+static struct attribute *default_ctx_attrs[] = {
+ NULL,
+};
+
+static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = {
+ .attr = {.name = "nr_tags", .mode = S_IRUGO },
+ .show = blk_mq_hw_sysfs_nr_tags_show,
+};
+static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = {
+ .attr = {.name = "nr_reserved_tags", .mode = S_IRUGO },
+ .show = blk_mq_hw_sysfs_nr_reserved_tags_show,
+};
+static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
+ .attr = {.name = "cpu_list", .mode = S_IRUGO },
+ .show = blk_mq_hw_sysfs_cpus_show,
+};
+
+static struct attribute *default_hw_ctx_attrs[] = {
+ &blk_mq_hw_sysfs_nr_tags.attr,
+ &blk_mq_hw_sysfs_nr_reserved_tags.attr,
+ &blk_mq_hw_sysfs_cpus.attr,
+ NULL,
+};
+
+static const struct sysfs_ops blk_mq_sysfs_ops = {
+ .show = blk_mq_sysfs_show,
+ .store = blk_mq_sysfs_store,
+};
+
+static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
+ .show = blk_mq_hw_sysfs_show,
+ .store = blk_mq_hw_sysfs_store,
+};
+
+static struct kobj_type blk_mq_ktype = {
+ .sysfs_ops = &blk_mq_sysfs_ops,
+ .release = blk_mq_sysfs_release,
+};
+
+static struct kobj_type blk_mq_ctx_ktype = {
+ .sysfs_ops = &blk_mq_sysfs_ops,
+ .default_attrs = default_ctx_attrs,
+ .release = blk_mq_sysfs_release,
+};
+
+static struct kobj_type blk_mq_hw_ktype = {
+ .sysfs_ops = &blk_mq_hw_sysfs_ops,
+ .default_attrs = default_hw_ctx_attrs,
+ .release = blk_mq_hw_sysfs_release,
+};
+
+static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ struct blk_mq_ctx *ctx;
+ int i;
+
+ if (!hctx->nr_ctx)
+ return;
+
+ hctx_for_each_ctx(hctx, ctx, i)
+ kobject_del(&ctx->kobj);
+
+ kobject_del(&hctx->kobj);
+}
+
+static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ struct request_queue *q = hctx->queue;
+ struct blk_mq_ctx *ctx;
+ int i, ret;
+
+ if (!hctx->nr_ctx)
+ return 0;
+
+ ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
+ if (ret)
+ return ret;
+
+ hctx_for_each_ctx(hctx, ctx, i) {
+ ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ lockdep_assert_held(&q->sysfs_lock);
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_unregister_hctx(hctx);
+
+ kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
+ kobject_del(&q->mq_kobj);
+ kobject_put(&dev->kobj);
+
+ q->mq_sysfs_init_done = false;
+}
+
+void blk_mq_unregister_dev(struct device *dev, struct request_queue *q)
+{
+ mutex_lock(&q->sysfs_lock);
+ __blk_mq_unregister_dev(dev, q);
+ mutex_unlock(&q->sysfs_lock);
+}
+
+void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx)
+{
+ kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
+}
+
+void blk_mq_sysfs_deinit(struct request_queue *q)
+{
+ struct blk_mq_ctx *ctx;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ ctx = per_cpu_ptr(q->queue_ctx, cpu);
+ kobject_put(&ctx->kobj);
+ }
+ kobject_put(&q->mq_kobj);
+}
+
+void blk_mq_sysfs_init(struct request_queue *q)
+{
+ struct blk_mq_ctx *ctx;
+ int cpu;
+
+ kobject_init(&q->mq_kobj, &blk_mq_ktype);
+
+ for_each_possible_cpu(cpu) {
+ ctx = per_cpu_ptr(q->queue_ctx, cpu);
+ kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
+ }
+}
+
+int __blk_mq_register_dev(struct device *dev, struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int ret, i;
+
+ WARN_ON_ONCE(!q->kobj.parent);
+ lockdep_assert_held(&q->sysfs_lock);
+
+ ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
+ if (ret < 0)
+ goto out;
+
+ kobject_uevent(&q->mq_kobj, KOBJ_ADD);
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ ret = blk_mq_register_hctx(hctx);
+ if (ret)
+ goto unreg;
+ }
+
+ q->mq_sysfs_init_done = true;
+
+out:
+ return ret;
+
+unreg:
+ while (--i >= 0)
+ blk_mq_unregister_hctx(q->queue_hw_ctx[i]);
+
+ kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);
+ kobject_del(&q->mq_kobj);
+ kobject_put(&dev->kobj);
+ return ret;
+}
+
+int blk_mq_register_dev(struct device *dev, struct request_queue *q)
+{
+ int ret;
+
+ mutex_lock(&q->sysfs_lock);
+ ret = __blk_mq_register_dev(dev, q);
+ mutex_unlock(&q->sysfs_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blk_mq_register_dev);
+
+void blk_mq_sysfs_unregister(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ mutex_lock(&q->sysfs_lock);
+ if (!q->mq_sysfs_init_done)
+ goto unlock;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_unregister_hctx(hctx);
+
+unlock:
+ mutex_unlock(&q->sysfs_lock);
+}
+
+int blk_mq_sysfs_register(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i, ret = 0;
+
+ mutex_lock(&q->sysfs_lock);
+ if (!q->mq_sysfs_init_done)
+ goto unlock;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ ret = blk_mq_register_hctx(hctx);
+ if (ret)
+ break;
+ }
+
+unlock:
+ mutex_unlock(&q->sysfs_lock);
+
+ return ret;
+}
diff --git a/src/kernel/linux/v4.14/block/blk-mq-tag.c b/src/kernel/linux/v4.14/block/blk-mq-tag.c
new file mode 100644
index 0000000..e4b3eea
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-tag.c
@@ -0,0 +1,496 @@
+/*
+ * Tag allocation using scalable bitmaps. Uses active queue tracking to support
+ * fairer distribution of tags between multiple submitters when a shared tag map
+ * is used.
+ *
+ * Copyright (C) 2013-2014 Jens Axboe
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/blk-mq.h>
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-tag.h"
+
+bool blk_mq_has_free_tags(struct blk_mq_tags *tags)
+{
+ if (!tags)
+ return true;
+
+ return sbitmap_any_bit_clear(&tags->bitmap_tags.sb);
+}
+
+/*
+ * If a previously inactive queue goes active, bump the active user count.
+ */
+bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
+{
+ if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) &&
+ !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
+ atomic_inc(&hctx->tags->active_queues);
+
+ return true;
+}
+
+/*
+ * Wakeup all potentially sleeping on tags
+ */
+void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve)
+{
+ sbitmap_queue_wake_all(&tags->bitmap_tags);
+ if (include_reserve)
+ sbitmap_queue_wake_all(&tags->breserved_tags);
+}
+
+/*
+ * If a previously busy queue goes inactive, potential waiters could now
+ * be allowed to queue. Wake them up and check.
+ */
+void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
+{
+ struct blk_mq_tags *tags = hctx->tags;
+
+ if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
+ return;
+
+ atomic_dec(&tags->active_queues);
+
+ blk_mq_tag_wakeup_all(tags, false);
+}
+
+/*
+ * For shared tag users, we track the number of currently active users
+ * and attempt to provide a fair share of the tag depth for each of them.
+ */
+static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
+ struct sbitmap_queue *bt)
+{
+ unsigned int depth, users;
+
+ if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED))
+ return true;
+ if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
+ return true;
+
+ /*
+ * Don't try dividing an ant
+ */
+ if (bt->sb.depth == 1)
+ return true;
+
+ users = atomic_read(&hctx->tags->active_queues);
+ if (!users)
+ return true;
+
+ /*
+ * Allow at least some tags
+ */
+ depth = max((bt->sb.depth + users - 1) / users, 4U);
+ return atomic_read(&hctx->nr_active) < depth;
+}
+
+static int __blk_mq_get_tag(struct blk_mq_alloc_data *data,
+ struct sbitmap_queue *bt)
+{
+ if (!(data->flags & BLK_MQ_REQ_INTERNAL) &&
+ !hctx_may_queue(data->hctx, bt))
+ return -1;
+ if (data->shallow_depth)
+ return __sbitmap_queue_get_shallow(bt, data->shallow_depth);
+ else
+ return __sbitmap_queue_get(bt);
+}
+
+unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
+{
+ struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
+ struct sbitmap_queue *bt;
+ struct sbq_wait_state *ws;
+ DEFINE_WAIT(wait);
+ unsigned int tag_offset;
+ bool drop_ctx;
+ int tag;
+
+ if (data->flags & BLK_MQ_REQ_RESERVED) {
+ if (unlikely(!tags->nr_reserved_tags)) {
+ WARN_ON_ONCE(1);
+ return BLK_MQ_TAG_FAIL;
+ }
+ bt = &tags->breserved_tags;
+ tag_offset = 0;
+ } else {
+ bt = &tags->bitmap_tags;
+ tag_offset = tags->nr_reserved_tags;
+ }
+
+ tag = __blk_mq_get_tag(data, bt);
+ if (tag != -1)
+ goto found_tag;
+
+ if (data->flags & BLK_MQ_REQ_NOWAIT)
+ return BLK_MQ_TAG_FAIL;
+
+ ws = bt_wait_ptr(bt, data->hctx);
+ drop_ctx = data->ctx == NULL;
+ do {
+ prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE);
+
+ tag = __blk_mq_get_tag(data, bt);
+ if (tag != -1)
+ break;
+
+ /*
+ * We're out of tags on this hardware queue, kick any
+ * pending IO submits before going to sleep waiting for
+ * some to complete.
+ */
+ blk_mq_run_hw_queue(data->hctx, false);
+
+ /*
+ * Retry tag allocation after running the hardware queue,
+ * as running the queue may also have found completions.
+ */
+ tag = __blk_mq_get_tag(data, bt);
+ if (tag != -1)
+ break;
+
+ if (data->ctx)
+ blk_mq_put_ctx(data->ctx);
+
+ io_schedule();
+
+ data->ctx = blk_mq_get_ctx(data->q);
+ data->hctx = blk_mq_map_queue(data->q, data->ctx->cpu);
+ tags = blk_mq_tags_from_data(data);
+ if (data->flags & BLK_MQ_REQ_RESERVED)
+ bt = &tags->breserved_tags;
+ else
+ bt = &tags->bitmap_tags;
+
+ finish_wait(&ws->wait, &wait);
+ ws = bt_wait_ptr(bt, data->hctx);
+ } while (1);
+
+ if (drop_ctx && data->ctx)
+ blk_mq_put_ctx(data->ctx);
+
+ finish_wait(&ws->wait, &wait);
+
+found_tag:
+ return tag + tag_offset;
+}
+
+void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags,
+ struct blk_mq_ctx *ctx, unsigned int tag)
+{
+ if (!blk_mq_tag_is_reserved(tags, tag)) {
+ const int real_tag = tag - tags->nr_reserved_tags;
+
+ BUG_ON(real_tag >= tags->nr_tags);
+ sbitmap_queue_clear(&tags->bitmap_tags, real_tag, ctx->cpu);
+ } else {
+ BUG_ON(tag >= tags->nr_reserved_tags);
+ sbitmap_queue_clear(&tags->breserved_tags, tag, ctx->cpu);
+ }
+}
+
+struct bt_iter_data {
+ struct blk_mq_hw_ctx *hctx;
+ busy_iter_fn *fn;
+ void *data;
+ bool reserved;
+};
+
+static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
+{
+ struct bt_iter_data *iter_data = data;
+ struct blk_mq_hw_ctx *hctx = iter_data->hctx;
+ struct blk_mq_tags *tags = hctx->tags;
+ bool reserved = iter_data->reserved;
+ struct request *rq;
+
+ if (!reserved)
+ bitnr += tags->nr_reserved_tags;
+ rq = tags->rqs[bitnr];
+
+ /*
+ * We can hit rq == NULL here, because the tagging functions
+ * test and set the bit before assining ->rqs[].
+ */
+ if (rq && rq->q == hctx->queue)
+ iter_data->fn(hctx, rq, iter_data->data, reserved);
+ return true;
+}
+
+static void bt_for_each(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt,
+ busy_iter_fn *fn, void *data, bool reserved)
+{
+ struct bt_iter_data iter_data = {
+ .hctx = hctx,
+ .fn = fn,
+ .data = data,
+ .reserved = reserved,
+ };
+
+ sbitmap_for_each_set(&bt->sb, bt_iter, &iter_data);
+}
+
+struct bt_tags_iter_data {
+ struct blk_mq_tags *tags;
+ busy_tag_iter_fn *fn;
+ void *data;
+ bool reserved;
+};
+
+static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
+{
+ struct bt_tags_iter_data *iter_data = data;
+ struct blk_mq_tags *tags = iter_data->tags;
+ bool reserved = iter_data->reserved;
+ struct request *rq;
+
+ if (!reserved)
+ bitnr += tags->nr_reserved_tags;
+
+ /*
+ * We can hit rq == NULL here, because the tagging functions
+ * test and set the bit before assining ->rqs[].
+ */
+ rq = tags->rqs[bitnr];
+ if (rq)
+ iter_data->fn(rq, iter_data->data, reserved);
+
+ return true;
+}
+
+static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt,
+ busy_tag_iter_fn *fn, void *data, bool reserved)
+{
+ struct bt_tags_iter_data iter_data = {
+ .tags = tags,
+ .fn = fn,
+ .data = data,
+ .reserved = reserved,
+ };
+
+ if (tags->rqs)
+ sbitmap_for_each_set(&bt->sb, bt_tags_iter, &iter_data);
+}
+
+static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags,
+ busy_tag_iter_fn *fn, void *priv)
+{
+ if (tags->nr_reserved_tags)
+ bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true);
+ bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false);
+}
+
+void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
+ busy_tag_iter_fn *fn, void *priv)
+{
+ int i;
+
+ for (i = 0; i < tagset->nr_hw_queues; i++) {
+ if (tagset->tags && tagset->tags[i])
+ blk_mq_all_tag_busy_iter(tagset->tags[i], fn, priv);
+ }
+}
+EXPORT_SYMBOL(blk_mq_tagset_busy_iter);
+
+int blk_mq_reinit_tagset(struct blk_mq_tag_set *set,
+ int (reinit_request)(void *, struct request *))
+{
+ int i, j, ret = 0;
+
+ if (WARN_ON_ONCE(!reinit_request))
+ goto out;
+
+ for (i = 0; i < set->nr_hw_queues; i++) {
+ struct blk_mq_tags *tags = set->tags[i];
+
+ if (!tags)
+ continue;
+
+ for (j = 0; j < tags->nr_tags; j++) {
+ if (!tags->static_rqs[j])
+ continue;
+
+ ret = reinit_request(set->driver_data,
+ tags->static_rqs[j]);
+ if (ret)
+ goto out;
+ }
+ }
+
+out:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blk_mq_reinit_tagset);
+
+void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
+ void *priv)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ /*
+ * __blk_mq_update_nr_hw_queues will update the nr_hw_queues and
+ * queue_hw_ctx after freeze the queue, so we use q_usage_counter
+ * to avoid race with it.
+ */
+ if (!percpu_ref_tryget(&q->q_usage_counter))
+ return;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ struct blk_mq_tags *tags = hctx->tags;
+
+ /*
+ * If not software queues are currently mapped to this
+ * hardware queue, there's nothing to check
+ */
+ if (!blk_mq_hw_queue_mapped(hctx))
+ continue;
+
+ if (tags->nr_reserved_tags)
+ bt_for_each(hctx, &tags->breserved_tags, fn, priv, true);
+ bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false);
+ }
+ blk_queue_exit(q);
+}
+
+static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth,
+ bool round_robin, int node)
+{
+ return sbitmap_queue_init_node(bt, depth, -1, round_robin, GFP_KERNEL,
+ node);
+}
+
+static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
+ int node, int alloc_policy)
+{
+ unsigned int depth = tags->nr_tags - tags->nr_reserved_tags;
+ bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR;
+
+ if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node))
+ goto free_tags;
+ if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin,
+ node))
+ goto free_bitmap_tags;
+
+ return tags;
+free_bitmap_tags:
+ sbitmap_queue_free(&tags->bitmap_tags);
+free_tags:
+ kfree(tags);
+ return NULL;
+}
+
+struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
+ unsigned int reserved_tags,
+ int node, int alloc_policy)
+{
+ struct blk_mq_tags *tags;
+
+ if (total_tags > BLK_MQ_TAG_MAX) {
+ pr_err("blk-mq: tag depth too large\n");
+ return NULL;
+ }
+
+ tags = kzalloc_node(sizeof(*tags), GFP_KERNEL, node);
+ if (!tags)
+ return NULL;
+
+ tags->nr_tags = total_tags;
+ tags->nr_reserved_tags = reserved_tags;
+
+ return blk_mq_init_bitmap_tags(tags, node, alloc_policy);
+}
+
+void blk_mq_free_tags(struct blk_mq_tags *tags)
+{
+ sbitmap_queue_free(&tags->bitmap_tags);
+ sbitmap_queue_free(&tags->breserved_tags);
+ kfree(tags);
+}
+
+int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_tags **tagsptr, unsigned int tdepth,
+ bool can_grow)
+{
+ struct blk_mq_tags *tags = *tagsptr;
+
+ if (tdepth <= tags->nr_reserved_tags)
+ return -EINVAL;
+
+ /*
+ * If we are allowed to grow beyond the original size, allocate
+ * a new set of tags before freeing the old one.
+ */
+ if (tdepth > tags->nr_tags) {
+ struct blk_mq_tag_set *set = hctx->queue->tag_set;
+ struct blk_mq_tags *new;
+ bool ret;
+
+ if (!can_grow)
+ return -EINVAL;
+
+ /*
+ * We need some sort of upper limit, set it high enough that
+ * no valid use cases should require more.
+ */
+ if (tdepth > 16 * BLKDEV_MAX_RQ)
+ return -EINVAL;
+
+ new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth,
+ tags->nr_reserved_tags);
+ if (!new)
+ return -ENOMEM;
+ ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth);
+ if (ret) {
+ blk_mq_free_rq_map(new);
+ return -ENOMEM;
+ }
+
+ blk_mq_free_rqs(set, *tagsptr, hctx->queue_num);
+ blk_mq_free_rq_map(*tagsptr);
+ *tagsptr = new;
+ } else {
+ /*
+ * Don't need (or can't) update reserved tags here, they
+ * remain static and should never need resizing.
+ */
+ sbitmap_queue_resize(&tags->bitmap_tags,
+ tdepth - tags->nr_reserved_tags);
+ }
+
+ return 0;
+}
+
+/**
+ * blk_mq_unique_tag() - return a tag that is unique queue-wide
+ * @rq: request for which to compute a unique tag
+ *
+ * The tag field in struct request is unique per hardware queue but not over
+ * all hardware queues. Hence this function that returns a tag with the
+ * hardware context index in the upper bits and the per hardware queue tag in
+ * the lower bits.
+ *
+ * Note: When called for a request that is queued on a non-multiqueue request
+ * queue, the hardware context index is set to zero.
+ */
+u32 blk_mq_unique_tag(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ struct blk_mq_hw_ctx *hctx;
+ int hwq = 0;
+
+ if (q->mq_ops) {
+ hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu);
+ hwq = hctx->queue_num;
+ }
+
+ return (hwq << BLK_MQ_UNIQUE_TAG_BITS) |
+ (rq->tag & BLK_MQ_UNIQUE_TAG_MASK);
+}
+EXPORT_SYMBOL(blk_mq_unique_tag);
diff --git a/src/kernel/linux/v4.14/block/blk-mq-tag.h b/src/kernel/linux/v4.14/block/blk-mq-tag.h
new file mode 100644
index 0000000..c190165
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-tag.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef INT_BLK_MQ_TAG_H
+#define INT_BLK_MQ_TAG_H
+
+#include "blk-mq.h"
+
+/*
+ * Tag address space map.
+ */
+struct blk_mq_tags {
+ unsigned int nr_tags;
+ unsigned int nr_reserved_tags;
+
+ atomic_t active_queues;
+
+ struct sbitmap_queue bitmap_tags;
+ struct sbitmap_queue breserved_tags;
+
+ struct request **rqs;
+ struct request **static_rqs;
+ struct list_head page_list;
+};
+
+
+extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node, int alloc_policy);
+extern void blk_mq_free_tags(struct blk_mq_tags *tags);
+
+extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
+extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags,
+ struct blk_mq_ctx *ctx, unsigned int tag);
+extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
+extern int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_tags **tags,
+ unsigned int depth, bool can_grow);
+extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
+void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
+ void *priv);
+
+static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
+ struct blk_mq_hw_ctx *hctx)
+{
+ if (!hctx)
+ return &bt->ws[0];
+ return sbq_wait_ptr(bt, &hctx->wait_index);
+}
+
+enum {
+ BLK_MQ_TAG_CACHE_MIN = 1,
+ BLK_MQ_TAG_CACHE_MAX = 64,
+};
+
+enum {
+ BLK_MQ_TAG_FAIL = -1U,
+ BLK_MQ_TAG_MIN = BLK_MQ_TAG_CACHE_MIN,
+ BLK_MQ_TAG_MAX = BLK_MQ_TAG_FAIL - 1,
+};
+
+extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
+extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
+
+static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
+{
+ if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
+ return false;
+
+ return __blk_mq_tag_busy(hctx);
+}
+
+static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
+{
+ if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
+ return;
+
+ __blk_mq_tag_idle(hctx);
+}
+
+/*
+ * This helper should only be used for flush request to share tag
+ * with the request cloned from, and both the two requests can't be
+ * in flight at the same time. The caller has to make sure the tag
+ * can't be freed.
+ */
+static inline void blk_mq_tag_set_rq(struct blk_mq_hw_ctx *hctx,
+ unsigned int tag, struct request *rq)
+{
+ hctx->tags->rqs[tag] = rq;
+}
+
+static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags,
+ unsigned int tag)
+{
+ return tag < tags->nr_reserved_tags;
+}
+
+#endif
diff --git a/src/kernel/linux/v4.14/block/blk-mq-virtio.c b/src/kernel/linux/v4.14/block/blk-mq-virtio.c
new file mode 100644
index 0000000..c3afbca
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq-virtio.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2016 Christoph Hellwig.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#include <linux/device.h>
+#include <linux/blk-mq.h>
+#include <linux/blk-mq-virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/module.h>
+#include "blk-mq.h"
+
+/**
+ * blk_mq_virtio_map_queues - provide a default queue mapping for virtio device
+ * @set: tagset to provide the mapping for
+ * @vdev: virtio device associated with @set.
+ * @first_vec: first interrupt vectors to use for queues (usually 0)
+ *
+ * This function assumes the virtio device @vdev has at least as many available
+ * interrupt vetors as @set has queues. It will then queuery the vector
+ * corresponding to each queue for it's affinity mask and built queue mapping
+ * that maps a queue to the CPUs that have irq affinity for the corresponding
+ * vector.
+ */
+int blk_mq_virtio_map_queues(struct blk_mq_tag_set *set,
+ struct virtio_device *vdev, int first_vec)
+{
+ const struct cpumask *mask;
+ unsigned int queue, cpu;
+
+ if (!vdev->config->get_vq_affinity)
+ goto fallback;
+
+ for (queue = 0; queue < set->nr_hw_queues; queue++) {
+ mask = vdev->config->get_vq_affinity(vdev, first_vec + queue);
+ if (!mask)
+ goto fallback;
+
+ for_each_cpu(cpu, mask)
+ set->mq_map[cpu] = queue;
+ }
+
+ return 0;
+fallback:
+ return blk_mq_map_queues(set);
+}
+EXPORT_SYMBOL_GPL(blk_mq_virtio_map_queues);
diff --git a/src/kernel/linux/v4.14/block/blk-mq.c b/src/kernel/linux/v4.14/block/blk-mq.c
new file mode 100644
index 0000000..cf56bda
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq.c
@@ -0,0 +1,2972 @@
+/*
+ * Block multiqueue core code
+ *
+ * Copyright (C) 2013-2014 Jens Axboe
+ * Copyright (C) 2013-2014 Christoph Hellwig
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/backing-dev.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/kmemleak.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/smp.h>
+#include <linux/llist.h>
+#include <linux/list_sort.h>
+#include <linux/cpu.h>
+#include <linux/cache.h>
+#include <linux/sched/sysctl.h>
+#include <linux/sched/topology.h>
+#include <linux/sched/signal.h>
+#include <linux/delay.h>
+#include <linux/crash_dump.h>
+#include <linux/prefetch.h>
+
+#include <trace/events/block.h>
+
+#include <linux/blk-mq.h>
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-debugfs.h"
+#include "blk-mq-tag.h"
+#include "blk-stat.h"
+#include "blk-wbt.h"
+#include "blk-mq-sched.h"
+
+static void blk_mq_poll_stats_start(struct request_queue *q);
+static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb);
+
+static int blk_mq_poll_stats_bkt(const struct request *rq)
+{
+ int ddir, bytes, bucket;
+
+ ddir = rq_data_dir(rq);
+ bytes = blk_rq_bytes(rq);
+
+ bucket = ddir + 2*(ilog2(bytes) - 9);
+
+ if (bucket < 0)
+ return -1;
+ else if (bucket >= BLK_MQ_POLL_STATS_BKTS)
+ return ddir + BLK_MQ_POLL_STATS_BKTS - 2;
+
+ return bucket;
+}
+
+/*
+ * Check if any of the ctx's have pending work in this hardware queue
+ */
+bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
+{
+ return sbitmap_any_bit_set(&hctx->ctx_map) ||
+ !list_empty_careful(&hctx->dispatch) ||
+ blk_mq_sched_has_work(hctx);
+}
+
+/*
+ * Mark this ctx as having pending work in this hardware queue
+ */
+static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *ctx)
+{
+ if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw))
+ sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw);
+}
+
+static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *ctx)
+{
+ sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw);
+}
+
+struct mq_inflight {
+ struct hd_struct *part;
+ unsigned int *inflight;
+};
+
+static void blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, void *priv,
+ bool reserved)
+{
+ struct mq_inflight *mi = priv;
+
+ if (test_bit(REQ_ATOM_STARTED, &rq->atomic_flags) &&
+ !test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) {
+ /*
+ * index[0] counts the specific partition that was asked
+ * for. index[1] counts the ones that are active on the
+ * whole device, so increment that if mi->part is indeed
+ * a partition, and not a whole device.
+ */
+ if (rq->part == mi->part)
+ mi->inflight[0]++;
+ if (mi->part->partno)
+ mi->inflight[1]++;
+ }
+}
+
+void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
+ unsigned int inflight[2])
+{
+ struct mq_inflight mi = { .part = part, .inflight = inflight, };
+
+ inflight[0] = inflight[1] = 0;
+ blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
+}
+
+static void blk_mq_check_inflight_rw(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, void *priv,
+ bool reserved)
+{
+ struct mq_inflight *mi = priv;
+
+ if (rq->part == mi->part)
+ mi->inflight[rq_data_dir(rq)]++;
+}
+
+void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+ unsigned int inflight[2])
+{
+ struct mq_inflight mi = { .part = part, .inflight = inflight, };
+
+ inflight[0] = inflight[1] = 0;
+ blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight_rw, &mi);
+}
+
+void blk_freeze_queue_start(struct request_queue *q)
+{
+ int freeze_depth;
+
+ freeze_depth = atomic_inc_return(&q->mq_freeze_depth);
+ if (freeze_depth == 1) {
+ percpu_ref_kill(&q->q_usage_counter);
+ blk_mq_run_hw_queues(q, false);
+ }
+}
+EXPORT_SYMBOL_GPL(blk_freeze_queue_start);
+
+void blk_mq_freeze_queue_wait(struct request_queue *q)
+{
+ wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
+}
+EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait);
+
+int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
+ unsigned long timeout)
+{
+ return wait_event_timeout(q->mq_freeze_wq,
+ percpu_ref_is_zero(&q->q_usage_counter),
+ timeout);
+}
+EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout);
+
+/*
+ * Guarantee no request is in use, so we can change any data structure of
+ * the queue afterward.
+ */
+void blk_freeze_queue(struct request_queue *q)
+{
+ /*
+ * In the !blk_mq case we are only calling this to kill the
+ * q_usage_counter, otherwise this increases the freeze depth
+ * and waits for it to return to zero. For this reason there is
+ * no blk_unfreeze_queue(), and blk_freeze_queue() is not
+ * exported to drivers as the only user for unfreeze is blk_mq.
+ */
+ blk_freeze_queue_start(q);
+ if (!q->mq_ops)
+ blk_drain_queue(q);
+ blk_mq_freeze_queue_wait(q);
+}
+
+void blk_mq_freeze_queue(struct request_queue *q)
+{
+ /*
+ * ...just an alias to keep freeze and unfreeze actions balanced
+ * in the blk_mq_* namespace
+ */
+ blk_freeze_queue(q);
+}
+EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);
+
+void blk_mq_unfreeze_queue(struct request_queue *q)
+{
+ int freeze_depth;
+
+ freeze_depth = atomic_dec_return(&q->mq_freeze_depth);
+ WARN_ON_ONCE(freeze_depth < 0);
+ if (!freeze_depth) {
+ percpu_ref_reinit(&q->q_usage_counter);
+ wake_up_all(&q->mq_freeze_wq);
+ }
+}
+EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
+
+/*
+ * FIXME: replace the scsi_internal_device_*block_nowait() calls in the
+ * mpt3sas driver such that this function can be removed.
+ */
+void blk_mq_quiesce_queue_nowait(struct request_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ queue_flag_set(QUEUE_FLAG_QUIESCED, q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait);
+
+/**
+ * blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished
+ * @q: request queue.
+ *
+ * Note: this function does not prevent that the struct request end_io()
+ * callback function is invoked. Once this function is returned, we make
+ * sure no dispatch can happen until the queue is unquiesced via
+ * blk_mq_unquiesce_queue().
+ */
+void blk_mq_quiesce_queue(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+ bool rcu = false;
+
+ blk_mq_quiesce_queue_nowait(q);
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (hctx->flags & BLK_MQ_F_BLOCKING)
+ synchronize_srcu(hctx->queue_rq_srcu);
+ else
+ rcu = true;
+ }
+ if (rcu)
+ synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue);
+
+/*
+ * blk_mq_unquiesce_queue() - counterpart of blk_mq_quiesce_queue()
+ * @q: request queue.
+ *
+ * This function recovers queue into the state before quiescing
+ * which is done by blk_mq_quiesce_queue.
+ */
+void blk_mq_unquiesce_queue(struct request_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ /* dispatch requests which are inserted during quiescing */
+ blk_mq_run_hw_queues(q, true);
+}
+EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue);
+
+void blk_mq_wake_waiters(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ if (blk_mq_hw_queue_mapped(hctx))
+ blk_mq_tag_wakeup_all(hctx->tags, true);
+
+ /*
+ * If we are called because the queue has now been marked as
+ * dying, we need to ensure that processes currently waiting on
+ * the queue are notified as well.
+ */
+ wake_up_all(&q->mq_freeze_wq);
+}
+
+bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
+{
+ return blk_mq_has_free_tags(hctx->tags);
+}
+EXPORT_SYMBOL(blk_mq_can_queue);
+
+static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
+ unsigned int tag, unsigned int op)
+{
+ struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
+ struct request *rq = tags->static_rqs[tag];
+
+ rq->rq_flags = 0;
+
+ if (data->flags & BLK_MQ_REQ_INTERNAL) {
+ rq->tag = -1;
+ rq->internal_tag = tag;
+ } else {
+ if (blk_mq_tag_busy(data->hctx)) {
+ rq->rq_flags = RQF_MQ_INFLIGHT;
+ atomic_inc(&data->hctx->nr_active);
+ }
+ rq->tag = tag;
+ rq->internal_tag = -1;
+ data->hctx->tags->rqs[rq->tag] = rq;
+ }
+
+ INIT_LIST_HEAD(&rq->queuelist);
+ /* csd/requeue_work/fifo_time is initialized before use */
+ rq->q = data->q;
+ rq->mq_ctx = data->ctx;
+ rq->cmd_flags = op;
+ if (blk_queue_io_stat(data->q))
+ rq->rq_flags |= RQF_IO_STAT;
+ /* do not touch atomic flags, it needs atomic ops against the timer */
+ rq->cpu = -1;
+ INIT_HLIST_NODE(&rq->hash);
+ RB_CLEAR_NODE(&rq->rb_node);
+ rq->rq_disk = NULL;
+ rq->part = NULL;
+ rq->start_time = jiffies;
+#ifdef CONFIG_BLK_CGROUP
+ rq->rl = NULL;
+ set_start_time_ns(rq);
+ rq->io_start_time_ns = 0;
+#endif
+ rq->nr_phys_segments = 0;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+ rq->nr_integrity_segments = 0;
+#endif
+ rq->special = NULL;
+ /* tag was already set */
+ rq->extra_len = 0;
+
+ INIT_LIST_HEAD(&rq->timeout_list);
+ rq->timeout = 0;
+
+ rq->end_io = NULL;
+ rq->end_io_data = NULL;
+ rq->next_rq = NULL;
+
+ data->ctx->rq_dispatched[op_is_sync(op)]++;
+ return rq;
+}
+
+static struct request *blk_mq_get_request(struct request_queue *q,
+ struct bio *bio, unsigned int op,
+ struct blk_mq_alloc_data *data)
+{
+ struct elevator_queue *e = q->elevator;
+ struct request *rq;
+ unsigned int tag;
+ struct blk_mq_ctx *local_ctx = NULL;
+
+ blk_queue_enter_live(q);
+ data->q = q;
+ if (likely(!data->ctx))
+ data->ctx = local_ctx = blk_mq_get_ctx(q);
+ if (likely(!data->hctx))
+ data->hctx = blk_mq_map_queue(q, data->ctx->cpu);
+ if (op & REQ_NOWAIT)
+ data->flags |= BLK_MQ_REQ_NOWAIT;
+
+ if (e) {
+ data->flags |= BLK_MQ_REQ_INTERNAL;
+
+ /*
+ * Flush requests are special and go directly to the
+ * dispatch list.
+ */
+ if (!op_is_flush(op) && e->type->ops.mq.limit_depth)
+ e->type->ops.mq.limit_depth(op, data);
+ }
+
+ tag = blk_mq_get_tag(data);
+ if (tag == BLK_MQ_TAG_FAIL) {
+ if (local_ctx) {
+ blk_mq_put_ctx(local_ctx);
+ data->ctx = NULL;
+ }
+ blk_queue_exit(q);
+ return NULL;
+ }
+
+ rq = blk_mq_rq_ctx_init(data, tag, op);
+ if (!op_is_flush(op)) {
+ rq->elv.icq = NULL;
+ if (e && e->type->ops.mq.prepare_request) {
+ if (e->type->icq_cache && rq_ioc(bio))
+ blk_mq_sched_assign_ioc(rq, bio);
+
+ e->type->ops.mq.prepare_request(rq, bio);
+ rq->rq_flags |= RQF_ELVPRIV;
+ }
+ }
+ data->hctx->queued++;
+ return rq;
+}
+
+struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
+ unsigned int flags)
+{
+ struct blk_mq_alloc_data alloc_data = { .flags = flags };
+ struct request *rq;
+ int ret;
+
+ ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT);
+ if (ret)
+ return ERR_PTR(ret);
+
+ rq = blk_mq_get_request(q, NULL, op, &alloc_data);
+ blk_queue_exit(q);
+
+ if (!rq)
+ return ERR_PTR(-EWOULDBLOCK);
+
+ blk_mq_put_ctx(alloc_data.ctx);
+
+ rq->__data_len = 0;
+ rq->__sector = (sector_t) -1;
+ rq->bio = rq->biotail = NULL;
+ return rq;
+}
+EXPORT_SYMBOL(blk_mq_alloc_request);
+
+struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
+ unsigned int op, unsigned int flags, unsigned int hctx_idx)
+{
+ struct blk_mq_alloc_data alloc_data = { .flags = flags };
+ struct request *rq;
+ unsigned int cpu;
+ int ret;
+
+ /*
+ * If the tag allocator sleeps we could get an allocation for a
+ * different hardware context. No need to complicate the low level
+ * allocator for this for the rare use case of a command tied to
+ * a specific queue.
+ */
+ if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)))
+ return ERR_PTR(-EINVAL);
+
+ if (hctx_idx >= q->nr_hw_queues)
+ return ERR_PTR(-EIO);
+
+ ret = blk_queue_enter(q, true);
+ if (ret)
+ return ERR_PTR(ret);
+
+ /*
+ * Check if the hardware context is actually mapped to anything.
+ * If not tell the caller that it should skip this queue.
+ */
+ alloc_data.hctx = q->queue_hw_ctx[hctx_idx];
+ if (!blk_mq_hw_queue_mapped(alloc_data.hctx)) {
+ blk_queue_exit(q);
+ return ERR_PTR(-EXDEV);
+ }
+ cpu = cpumask_first(alloc_data.hctx->cpumask);
+ alloc_data.ctx = __blk_mq_get_ctx(q, cpu);
+
+ rq = blk_mq_get_request(q, NULL, op, &alloc_data);
+ blk_queue_exit(q);
+
+ if (!rq)
+ return ERR_PTR(-EWOULDBLOCK);
+
+ return rq;
+}
+EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
+
+void blk_mq_free_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
+ const int sched_tag = rq->internal_tag;
+
+ if (rq->rq_flags & RQF_ELVPRIV) {
+ if (e && e->type->ops.mq.finish_request)
+ e->type->ops.mq.finish_request(rq);
+ if (rq->elv.icq) {
+ put_io_context(rq->elv.icq->ioc);
+ rq->elv.icq = NULL;
+ }
+ }
+
+ ctx->rq_completed[rq_is_sync(rq)]++;
+ if (rq->rq_flags & RQF_MQ_INFLIGHT)
+ atomic_dec(&hctx->nr_active);
+
+ wbt_done(q->rq_wb, &rq->issue_stat);
+
+ clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
+ clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags);
+ if (rq->tag != -1)
+ blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag);
+ if (sched_tag != -1)
+ blk_mq_put_tag(hctx, hctx->sched_tags, ctx, sched_tag);
+ blk_mq_sched_restart(hctx);
+ blk_queue_exit(q);
+}
+EXPORT_SYMBOL_GPL(blk_mq_free_request);
+
+inline void __blk_mq_end_request(struct request *rq, blk_status_t error)
+{
+ blk_account_io_done(rq);
+
+ if (rq->end_io) {
+ wbt_done(rq->q->rq_wb, &rq->issue_stat);
+ rq->end_io(rq, error);
+ } else {
+ if (unlikely(blk_bidi_rq(rq)))
+ blk_mq_free_request(rq->next_rq);
+ blk_mq_free_request(rq);
+ }
+}
+EXPORT_SYMBOL(__blk_mq_end_request);
+
+void blk_mq_end_request(struct request *rq, blk_status_t error)
+{
+ if (blk_update_request(rq, error, blk_rq_bytes(rq)))
+ BUG();
+ __blk_mq_end_request(rq, error);
+}
+EXPORT_SYMBOL(blk_mq_end_request);
+
+static void __blk_mq_complete_request_remote(void *data)
+{
+ struct request *rq = data;
+
+ rq->q->softirq_done_fn(rq);
+}
+
+static void __blk_mq_complete_request(struct request *rq)
+{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+ bool shared = false;
+ int cpu;
+
+ if (rq->internal_tag != -1)
+ blk_mq_sched_completed_request(rq);
+ if (rq->rq_flags & RQF_STATS) {
+ blk_mq_poll_stats_start(rq->q);
+ blk_stat_add(rq);
+ }
+
+ if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) {
+ rq->q->softirq_done_fn(rq);
+ return;
+ }
+
+ cpu = get_cpu();
+ if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags))
+ shared = cpus_share_cache(cpu, ctx->cpu);
+
+ if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
+ rq->csd.func = __blk_mq_complete_request_remote;
+ rq->csd.info = rq;
+ rq->csd.flags = 0;
+ smp_call_function_single_async(ctx->cpu, &rq->csd);
+ } else {
+ rq->q->softirq_done_fn(rq);
+ }
+ put_cpu();
+}
+
+/**
+ * blk_mq_complete_request - end I/O on a request
+ * @rq: the request being processed
+ *
+ * Description:
+ * Ends all I/O on a request. It does not handle partial completions.
+ * The actual completion happens out-of-order, through a IPI handler.
+ **/
+void blk_mq_complete_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+
+ if (unlikely(blk_should_fake_timeout(q)))
+ return;
+ if (!blk_mark_rq_complete(rq))
+ __blk_mq_complete_request(rq);
+}
+EXPORT_SYMBOL(blk_mq_complete_request);
+
+int blk_mq_request_started(struct request *rq)
+{
+ return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
+}
+EXPORT_SYMBOL_GPL(blk_mq_request_started);
+
+void blk_mq_start_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+
+ blk_mq_sched_started_request(rq);
+
+ trace_block_rq_issue(q, rq);
+
+ if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) {
+ blk_stat_set_issue(&rq->issue_stat, blk_rq_sectors(rq));
+ rq->rq_flags |= RQF_STATS;
+ wbt_issue(q->rq_wb, &rq->issue_stat);
+ }
+
+ blk_add_timer(rq);
+
+ /*
+ * Ensure that ->deadline is visible before set the started
+ * flag and clear the completed flag.
+ */
+ smp_mb__before_atomic();
+
+ /*
+ * Mark us as started and clear complete. Complete might have been
+ * set if requeue raced with timeout, which then marked it as
+ * complete. So be sure to clear complete again when we start
+ * the request, otherwise we'll ignore the completion event.
+ */
+ if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
+ set_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
+ if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags))
+ clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+
+ if (q->dma_drain_size && blk_rq_bytes(rq)) {
+ /*
+ * Make sure space for the drain appears. We know we can do
+ * this because max_hw_segments has been adjusted to be one
+ * fewer than the device can handle.
+ */
+ rq->nr_phys_segments++;
+ }
+}
+EXPORT_SYMBOL(blk_mq_start_request);
+
+/*
+ * When we reach here because queue is busy, REQ_ATOM_COMPLETE
+ * flag isn't set yet, so there may be race with timeout handler,
+ * but given rq->deadline is just set in .queue_rq() under
+ * this situation, the race won't be possible in reality because
+ * rq->timeout should be set as big enough to cover the window
+ * between blk_mq_start_request() called from .queue_rq() and
+ * clearing REQ_ATOM_STARTED here.
+ */
+static void __blk_mq_requeue_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+
+ trace_block_rq_requeue(q, rq);
+ wbt_requeue(q->rq_wb, &rq->issue_stat);
+
+ if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
+ if (q->dma_drain_size && blk_rq_bytes(rq))
+ rq->nr_phys_segments--;
+ }
+}
+
+void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list)
+{
+ __blk_mq_requeue_request(rq);
+
+ /* this request will be re-inserted to io scheduler queue */
+ blk_mq_sched_requeue_request(rq);
+
+ BUG_ON(blk_queued_rq(rq));
+ blk_mq_add_to_requeue_list(rq, true, kick_requeue_list);
+}
+EXPORT_SYMBOL(blk_mq_requeue_request);
+
+static void blk_mq_requeue_work(struct work_struct *work)
+{
+ struct request_queue *q =
+ container_of(work, struct request_queue, requeue_work.work);
+ LIST_HEAD(rq_list);
+ struct request *rq, *next;
+
+ spin_lock_irq(&q->requeue_lock);
+ list_splice_init(&q->requeue_list, &rq_list);
+ spin_unlock_irq(&q->requeue_lock);
+
+ list_for_each_entry_safe(rq, next, &rq_list, queuelist) {
+ if (!(rq->rq_flags & RQF_SOFTBARRIER))
+ continue;
+
+ rq->rq_flags &= ~RQF_SOFTBARRIER;
+ list_del_init(&rq->queuelist);
+ blk_mq_sched_insert_request(rq, true, false, false, true);
+ }
+
+ while (!list_empty(&rq_list)) {
+ rq = list_entry(rq_list.next, struct request, queuelist);
+ list_del_init(&rq->queuelist);
+ blk_mq_sched_insert_request(rq, false, false, false, true);
+ }
+
+ blk_mq_run_hw_queues(q, false);
+}
+
+void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
+ bool kick_requeue_list)
+{
+ struct request_queue *q = rq->q;
+ unsigned long flags;
+
+ /*
+ * We abuse this flag that is otherwise used by the I/O scheduler to
+ * request head insertation from the workqueue.
+ */
+ BUG_ON(rq->rq_flags & RQF_SOFTBARRIER);
+
+ spin_lock_irqsave(&q->requeue_lock, flags);
+ if (at_head) {
+ rq->rq_flags |= RQF_SOFTBARRIER;
+ list_add(&rq->queuelist, &q->requeue_list);
+ } else {
+ list_add_tail(&rq->queuelist, &q->requeue_list);
+ }
+ spin_unlock_irqrestore(&q->requeue_lock, flags);
+
+ if (kick_requeue_list)
+ blk_mq_kick_requeue_list(q);
+}
+EXPORT_SYMBOL(blk_mq_add_to_requeue_list);
+
+void blk_mq_kick_requeue_list(struct request_queue *q)
+{
+ kblockd_schedule_delayed_work(&q->requeue_work, 0);
+}
+EXPORT_SYMBOL(blk_mq_kick_requeue_list);
+
+void blk_mq_delay_kick_requeue_list(struct request_queue *q,
+ unsigned long msecs)
+{
+ kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work,
+ msecs_to_jiffies(msecs));
+}
+EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list);
+
+struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
+{
+ if (tag < tags->nr_tags) {
+ prefetch(tags->rqs[tag]);
+ return tags->rqs[tag];
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL(blk_mq_tag_to_rq);
+
+struct blk_mq_timeout_data {
+ unsigned long next;
+ unsigned int next_set;
+};
+
+void blk_mq_rq_timed_out(struct request *req, bool reserved)
+{
+ const struct blk_mq_ops *ops = req->q->mq_ops;
+ enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
+
+ /*
+ * We know that complete is set at this point. If STARTED isn't set
+ * anymore, then the request isn't active and the "timeout" should
+ * just be ignored. This can happen due to the bitflag ordering.
+ * Timeout first checks if STARTED is set, and if it is, assumes
+ * the request is active. But if we race with completion, then
+ * both flags will get cleared. So check here again, and ignore
+ * a timeout event with a request that isn't active.
+ */
+ if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags))
+ return;
+
+ if (ops->timeout)
+ ret = ops->timeout(req, reserved);
+
+ switch (ret) {
+ case BLK_EH_HANDLED:
+ __blk_mq_complete_request(req);
+ break;
+ case BLK_EH_RESET_TIMER:
+ blk_add_timer(req);
+ blk_clear_rq_complete(req);
+ break;
+ case BLK_EH_NOT_HANDLED:
+ break;
+ default:
+ printk(KERN_ERR "block: bad eh return: %d\n", ret);
+ break;
+ }
+}
+
+static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, void *priv, bool reserved)
+{
+ struct blk_mq_timeout_data *data = priv;
+
+ if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
+ return;
+
+ /*
+ * The rq being checked may have been freed and reallocated
+ * out already here, we avoid this race by checking rq->deadline
+ * and REQ_ATOM_COMPLETE flag together:
+ *
+ * - if rq->deadline is observed as new value because of
+ * reusing, the rq won't be timed out because of timing.
+ * - if rq->deadline is observed as previous value,
+ * REQ_ATOM_COMPLETE flag won't be cleared in reuse path
+ * because we put a barrier between setting rq->deadline
+ * and clearing the flag in blk_mq_start_request(), so
+ * this rq won't be timed out too.
+ */
+ if (time_after_eq(jiffies, rq->deadline)) {
+ if (!blk_mark_rq_complete(rq))
+ blk_mq_rq_timed_out(rq, reserved);
+ } else if (!data->next_set || time_after(data->next, rq->deadline)) {
+ data->next = rq->deadline;
+ data->next_set = 1;
+ }
+}
+
+static void blk_mq_timeout_work(struct work_struct *work)
+{
+ struct request_queue *q =
+ container_of(work, struct request_queue, timeout_work);
+ struct blk_mq_timeout_data data = {
+ .next = 0,
+ .next_set = 0,
+ };
+ int i;
+
+ /* A deadlock might occur if a request is stuck requiring a
+ * timeout at the same time a queue freeze is waiting
+ * completion, since the timeout code would not be able to
+ * acquire the queue reference here.
+ *
+ * That's why we don't use blk_queue_enter here; instead, we use
+ * percpu_ref_tryget directly, because we need to be able to
+ * obtain a reference even in the short window between the queue
+ * starting to freeze, by dropping the first reference in
+ * blk_freeze_queue_start, and the moment the last request is
+ * consumed, marked by the instant q_usage_counter reaches
+ * zero.
+ */
+ if (!percpu_ref_tryget(&q->q_usage_counter))
+ return;
+
+ blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data);
+
+ if (data.next_set) {
+ data.next = blk_rq_timeout(round_jiffies_up(data.next));
+ mod_timer(&q->timeout, data.next);
+ } else {
+ struct blk_mq_hw_ctx *hctx;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ /* the hctx may be unmapped, so check it here */
+ if (blk_mq_hw_queue_mapped(hctx))
+ blk_mq_tag_idle(hctx);
+ }
+ }
+ blk_queue_exit(q);
+}
+
+struct flush_busy_ctx_data {
+ struct blk_mq_hw_ctx *hctx;
+ struct list_head *list;
+};
+
+static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data)
+{
+ struct flush_busy_ctx_data *flush_data = data;
+ struct blk_mq_hw_ctx *hctx = flush_data->hctx;
+ struct blk_mq_ctx *ctx = hctx->ctxs[bitnr];
+
+ sbitmap_clear_bit(sb, bitnr);
+ spin_lock(&ctx->lock);
+ list_splice_tail_init(&ctx->rq_list, flush_data->list);
+ spin_unlock(&ctx->lock);
+ return true;
+}
+
+/*
+ * Process software queues that have been marked busy, splicing them
+ * to the for-dispatch
+ */
+void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
+{
+ struct flush_busy_ctx_data data = {
+ .hctx = hctx,
+ .list = list,
+ };
+
+ sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data);
+}
+EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs);
+
+static inline unsigned int queued_to_index(unsigned int queued)
+{
+ if (!queued)
+ return 0;
+
+ return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1);
+}
+
+bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
+ bool wait)
+{
+ struct blk_mq_alloc_data data = {
+ .q = rq->q,
+ .hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu),
+ .flags = wait ? 0 : BLK_MQ_REQ_NOWAIT,
+ };
+
+ might_sleep_if(wait);
+
+ if (rq->tag != -1)
+ goto done;
+
+ if (blk_mq_tag_is_reserved(data.hctx->sched_tags, rq->internal_tag))
+ data.flags |= BLK_MQ_REQ_RESERVED;
+
+ rq->tag = blk_mq_get_tag(&data);
+ if (rq->tag >= 0) {
+ if (blk_mq_tag_busy(data.hctx)) {
+ rq->rq_flags |= RQF_MQ_INFLIGHT;
+ atomic_inc(&data.hctx->nr_active);
+ }
+ data.hctx->tags->rqs[rq->tag] = rq;
+ }
+
+done:
+ if (hctx)
+ *hctx = data.hctx;
+ return rq->tag != -1;
+}
+
+static void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
+ struct request *rq)
+{
+ blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
+ rq->tag = -1;
+
+ if (rq->rq_flags & RQF_MQ_INFLIGHT) {
+ rq->rq_flags &= ~RQF_MQ_INFLIGHT;
+ atomic_dec(&hctx->nr_active);
+ }
+}
+
+static void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
+ struct request *rq)
+{
+ if (rq->tag == -1 || rq->internal_tag == -1)
+ return;
+
+ __blk_mq_put_driver_tag(hctx, rq);
+}
+
+static void blk_mq_put_driver_tag(struct request *rq)
+{
+ struct blk_mq_hw_ctx *hctx;
+
+ if (rq->tag == -1 || rq->internal_tag == -1)
+ return;
+
+ hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
+ __blk_mq_put_driver_tag(hctx, rq);
+}
+
+/*
+ * If we fail getting a driver tag because all the driver tags are already
+ * assigned and on the dispatch list, BUT the first entry does not have a
+ * tag, then we could deadlock. For that case, move entries with assigned
+ * driver tags to the front, leaving the set of tagged requests in the
+ * same order, and the untagged set in the same order.
+ */
+static bool reorder_tags_to_front(struct list_head *list)
+{
+ struct request *rq, *tmp, *first = NULL;
+
+ list_for_each_entry_safe_reverse(rq, tmp, list, queuelist) {
+ if (rq == first)
+ break;
+ if (rq->tag != -1) {
+ list_move(&rq->queuelist, list);
+ if (!first)
+ first = rq;
+ }
+ }
+
+ return first != NULL;
+}
+
+static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, int flags,
+ void *key)
+{
+ struct blk_mq_hw_ctx *hctx;
+
+ hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait);
+
+ list_del(&wait->entry);
+ clear_bit_unlock(BLK_MQ_S_TAG_WAITING, &hctx->state);
+ blk_mq_run_hw_queue(hctx, true);
+ return 1;
+}
+
+static bool blk_mq_dispatch_wait_add(struct blk_mq_hw_ctx *hctx)
+{
+ struct sbq_wait_state *ws;
+
+ /*
+ * The TAG_WAITING bit serves as a lock protecting hctx->dispatch_wait.
+ * The thread which wins the race to grab this bit adds the hardware
+ * queue to the wait queue.
+ */
+ if (test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state) ||
+ test_and_set_bit_lock(BLK_MQ_S_TAG_WAITING, &hctx->state))
+ return false;
+
+ init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake);
+ ws = bt_wait_ptr(&hctx->tags->bitmap_tags, hctx);
+
+ /*
+ * As soon as this returns, it's no longer safe to fiddle with
+ * hctx->dispatch_wait, since a completion can wake up the wait queue
+ * and unlock the bit.
+ */
+ add_wait_queue(&ws->wait, &hctx->dispatch_wait);
+ return true;
+}
+
+bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list)
+{
+ struct blk_mq_hw_ctx *hctx;
+ struct request *rq;
+ int errors, queued;
+
+ if (list_empty(list))
+ return false;
+
+ /*
+ * Now process all the entries, sending them to the driver.
+ */
+ errors = queued = 0;
+ do {
+ struct blk_mq_queue_data bd;
+ blk_status_t ret;
+
+ rq = list_first_entry(list, struct request, queuelist);
+ if (!blk_mq_get_driver_tag(rq, &hctx, false)) {
+ if (!queued && reorder_tags_to_front(list))
+ continue;
+
+ /*
+ * The initial allocation attempt failed, so we need to
+ * rerun the hardware queue when a tag is freed.
+ */
+ if (!blk_mq_dispatch_wait_add(hctx))
+ break;
+
+ /*
+ * It's possible that a tag was freed in the window
+ * between the allocation failure and adding the
+ * hardware queue to the wait queue.
+ */
+ if (!blk_mq_get_driver_tag(rq, &hctx, false))
+ break;
+ }
+
+ list_del_init(&rq->queuelist);
+
+ bd.rq = rq;
+
+ /*
+ * Flag last if we have no more requests, or if we have more
+ * but can't assign a driver tag to it.
+ */
+ if (list_empty(list))
+ bd.last = true;
+ else {
+ struct request *nxt;
+
+ nxt = list_first_entry(list, struct request, queuelist);
+ bd.last = !blk_mq_get_driver_tag(nxt, NULL, false);
+ }
+
+ ret = q->mq_ops->queue_rq(hctx, &bd);
+ if (ret == BLK_STS_RESOURCE) {
+ blk_mq_put_driver_tag_hctx(hctx, rq);
+ list_add(&rq->queuelist, list);
+ __blk_mq_requeue_request(rq);
+ break;
+ }
+
+ if (unlikely(ret != BLK_STS_OK)) {
+ errors++;
+ blk_mq_end_request(rq, BLK_STS_IOERR);
+ continue;
+ }
+
+ queued++;
+ } while (!list_empty(list));
+
+ hctx->dispatched[queued_to_index(queued)]++;
+
+ /*
+ * Any items that need requeuing? Stuff them into hctx->dispatch,
+ * that is where we will continue on next queue run.
+ */
+ if (!list_empty(list)) {
+ /*
+ * If an I/O scheduler has been configured and we got a driver
+ * tag for the next request already, free it again.
+ */
+ rq = list_first_entry(list, struct request, queuelist);
+ blk_mq_put_driver_tag(rq);
+
+ spin_lock(&hctx->lock);
+ list_splice_init(list, &hctx->dispatch);
+ spin_unlock(&hctx->lock);
+
+ /*
+ * If SCHED_RESTART was set by the caller of this function and
+ * it is no longer set that means that it was cleared by another
+ * thread and hence that a queue rerun is needed.
+ *
+ * If TAG_WAITING is set that means that an I/O scheduler has
+ * been configured and another thread is waiting for a driver
+ * tag. To guarantee fairness, do not rerun this hardware queue
+ * but let the other thread grab the driver tag.
+ *
+ * If no I/O scheduler has been configured it is possible that
+ * the hardware queue got stopped and restarted before requests
+ * were pushed back onto the dispatch list. Rerun the queue to
+ * avoid starvation. Notes:
+ * - blk_mq_run_hw_queue() checks whether or not a queue has
+ * been stopped before rerunning a queue.
+ * - Some but not all block drivers stop a queue before
+ * returning BLK_STS_RESOURCE. Two exceptions are scsi-mq
+ * and dm-rq.
+ */
+ if (!blk_mq_sched_needs_restart(hctx) &&
+ !test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state))
+ blk_mq_run_hw_queue(hctx, true);
+ }
+
+ return (queued + errors) != 0;
+}
+
+static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
+{
+ int srcu_idx;
+
+ /*
+ * We should be running this queue from one of the CPUs that
+ * are mapped to it.
+ *
+ * There are at least two related races now between setting
+ * hctx->next_cpu from blk_mq_hctx_next_cpu() and running
+ * __blk_mq_run_hw_queue():
+ *
+ * - hctx->next_cpu is found offline in blk_mq_hctx_next_cpu(),
+ * but later it becomes online, then this warning is harmless
+ * at all
+ *
+ * - hctx->next_cpu is found online in blk_mq_hctx_next_cpu(),
+ * but later it becomes offline, then the warning can't be
+ * triggered, and we depend on blk-mq timeout handler to
+ * handle dispatched requests to this hctx
+ */
+ if (!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
+ cpu_online(hctx->next_cpu)) {
+ printk(KERN_WARNING "run queue from wrong CPU %d, hctx %s\n",
+ raw_smp_processor_id(),
+ cpumask_empty(hctx->cpumask) ? "inactive": "active");
+ dump_stack();
+ }
+
+ /*
+ * We can't run the queue inline with ints disabled. Ensure that
+ * we catch bad users of this early.
+ */
+ WARN_ON_ONCE(in_interrupt());
+
+ if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
+ rcu_read_lock();
+ blk_mq_sched_dispatch_requests(hctx);
+ rcu_read_unlock();
+ } else {
+ might_sleep();
+
+ srcu_idx = srcu_read_lock(hctx->queue_rq_srcu);
+ blk_mq_sched_dispatch_requests(hctx);
+ srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx);
+ }
+}
+
+/*
+ * It'd be great if the workqueue API had a way to pass
+ * in a mask and had some smarts for more clever placement.
+ * For now we just round-robin here, switching for every
+ * BLK_MQ_CPU_WORK_BATCH queued items.
+ */
+static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
+{
+ if (hctx->queue->nr_hw_queues == 1)
+ return WORK_CPU_UNBOUND;
+
+ if (--hctx->next_cpu_batch <= 0) {
+ int next_cpu;
+
+ next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask);
+ if (next_cpu >= nr_cpu_ids)
+ next_cpu = cpumask_first(hctx->cpumask);
+
+ hctx->next_cpu = next_cpu;
+ hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
+ }
+
+ return hctx->next_cpu;
+}
+
+static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async,
+ unsigned long msecs)
+{
+ if (WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx)))
+ return;
+
+ if (unlikely(blk_mq_hctx_stopped(hctx)))
+ return;
+
+ if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
+ int cpu = get_cpu();
+ if (cpumask_test_cpu(cpu, hctx->cpumask)) {
+ __blk_mq_run_hw_queue(hctx);
+ put_cpu();
+ return;
+ }
+
+ put_cpu();
+ }
+
+ kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
+ &hctx->run_work,
+ msecs_to_jiffies(msecs));
+}
+
+void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
+{
+ __blk_mq_delay_run_hw_queue(hctx, true, msecs);
+}
+EXPORT_SYMBOL(blk_mq_delay_run_hw_queue);
+
+void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
+{
+ __blk_mq_delay_run_hw_queue(hctx, async, 0);
+}
+EXPORT_SYMBOL(blk_mq_run_hw_queue);
+
+void blk_mq_run_hw_queues(struct request_queue *q, bool async)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (!blk_mq_hctx_has_pending(hctx) ||
+ blk_mq_hctx_stopped(hctx))
+ continue;
+
+ blk_mq_run_hw_queue(hctx, async);
+ }
+}
+EXPORT_SYMBOL(blk_mq_run_hw_queues);
+
+/**
+ * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped
+ * @q: request queue.
+ *
+ * The caller is responsible for serializing this function against
+ * blk_mq_{start,stop}_hw_queue().
+ */
+bool blk_mq_queue_stopped(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ if (blk_mq_hctx_stopped(hctx))
+ return true;
+
+ return false;
+}
+EXPORT_SYMBOL(blk_mq_queue_stopped);
+
+/*
+ * This function is often used for pausing .queue_rq() by driver when
+ * there isn't enough resource or some conditions aren't satisfied, and
+ * BLK_STS_RESOURCE is usually returned.
+ *
+ * We do not guarantee that dispatch can be drained or blocked
+ * after blk_mq_stop_hw_queue() returns. Please use
+ * blk_mq_quiesce_queue() for that requirement.
+ */
+void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
+{
+ cancel_delayed_work(&hctx->run_work);
+
+ set_bit(BLK_MQ_S_STOPPED, &hctx->state);
+}
+EXPORT_SYMBOL(blk_mq_stop_hw_queue);
+
+/*
+ * This function is often used for pausing .queue_rq() by driver when
+ * there isn't enough resource or some conditions aren't satisfied, and
+ * BLK_STS_RESOURCE is usually returned.
+ *
+ * We do not guarantee that dispatch can be drained or blocked
+ * after blk_mq_stop_hw_queues() returns. Please use
+ * blk_mq_quiesce_queue() for that requirement.
+ */
+void blk_mq_stop_hw_queues(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_stop_hw_queue(hctx);
+}
+EXPORT_SYMBOL(blk_mq_stop_hw_queues);
+
+void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
+{
+ clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
+
+ blk_mq_run_hw_queue(hctx, false);
+}
+EXPORT_SYMBOL(blk_mq_start_hw_queue);
+
+void blk_mq_start_hw_queues(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_start_hw_queue(hctx);
+}
+EXPORT_SYMBOL(blk_mq_start_hw_queues);
+
+void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
+{
+ if (!blk_mq_hctx_stopped(hctx))
+ return;
+
+ clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
+ blk_mq_run_hw_queue(hctx, async);
+}
+EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue);
+
+void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_start_stopped_hw_queue(hctx, async);
+}
+EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
+
+static void blk_mq_run_work_fn(struct work_struct *work)
+{
+ struct blk_mq_hw_ctx *hctx;
+
+ hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work);
+
+ /*
+ * If we are stopped, don't run the queue. The exception is if
+ * BLK_MQ_S_START_ON_RUN is set. For that case, we auto-clear
+ * the STOPPED bit and run it.
+ */
+ if (test_bit(BLK_MQ_S_STOPPED, &hctx->state)) {
+ if (!test_bit(BLK_MQ_S_START_ON_RUN, &hctx->state))
+ return;
+
+ clear_bit(BLK_MQ_S_START_ON_RUN, &hctx->state);
+ clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
+ }
+
+ __blk_mq_run_hw_queue(hctx);
+}
+
+
+void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
+{
+ if (WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx)))
+ return;
+
+ /*
+ * Stop the hw queue, then modify currently delayed work.
+ * This should prevent us from running the queue prematurely.
+ * Mark the queue as auto-clearing STOPPED when it runs.
+ */
+ blk_mq_stop_hw_queue(hctx);
+ set_bit(BLK_MQ_S_START_ON_RUN, &hctx->state);
+ kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
+ &hctx->run_work,
+ msecs_to_jiffies(msecs));
+}
+EXPORT_SYMBOL(blk_mq_delay_queue);
+
+static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
+ struct request *rq,
+ bool at_head)
+{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+
+ lockdep_assert_held(&ctx->lock);
+
+ trace_block_rq_insert(hctx->queue, rq);
+
+ if (at_head)
+ list_add(&rq->queuelist, &ctx->rq_list);
+ else
+ list_add_tail(&rq->queuelist, &ctx->rq_list);
+}
+
+void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
+ bool at_head)
+{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+
+ lockdep_assert_held(&ctx->lock);
+
+ __blk_mq_insert_req_list(hctx, rq, at_head);
+ blk_mq_hctx_mark_pending(hctx, ctx);
+}
+
+/*
+ * Should only be used carefully, when the caller knows we want to
+ * bypass a potential IO scheduler on the target device.
+ */
+void blk_mq_request_bypass_insert(struct request *rq)
+{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(rq->q, ctx->cpu);
+
+ spin_lock(&hctx->lock);
+ list_add_tail(&rq->queuelist, &hctx->dispatch);
+ spin_unlock(&hctx->lock);
+
+ blk_mq_run_hw_queue(hctx, false);
+}
+
+void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+ struct list_head *list)
+
+{
+ /*
+ * preemption doesn't flush plug list, so it's possible ctx->cpu is
+ * offline now
+ */
+ spin_lock(&ctx->lock);
+ while (!list_empty(list)) {
+ struct request *rq;
+
+ rq = list_first_entry(list, struct request, queuelist);
+ BUG_ON(rq->mq_ctx != ctx);
+ list_del_init(&rq->queuelist);
+ __blk_mq_insert_req_list(hctx, rq, false);
+ }
+ blk_mq_hctx_mark_pending(hctx, ctx);
+ spin_unlock(&ctx->lock);
+}
+
+static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct request *rqa = container_of(a, struct request, queuelist);
+ struct request *rqb = container_of(b, struct request, queuelist);
+
+ return !(rqa->mq_ctx < rqb->mq_ctx ||
+ (rqa->mq_ctx == rqb->mq_ctx &&
+ blk_rq_pos(rqa) < blk_rq_pos(rqb)));
+}
+
+void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
+{
+ struct blk_mq_ctx *this_ctx;
+ struct request_queue *this_q;
+ struct request *rq;
+ LIST_HEAD(list);
+ LIST_HEAD(ctx_list);
+ unsigned int depth;
+
+ list_splice_init(&plug->mq_list, &list);
+
+ list_sort(NULL, &list, plug_ctx_cmp);
+
+ this_q = NULL;
+ this_ctx = NULL;
+ depth = 0;
+
+ while (!list_empty(&list)) {
+ rq = list_entry_rq(list.next);
+ list_del_init(&rq->queuelist);
+ BUG_ON(!rq->q);
+ if (rq->mq_ctx != this_ctx) {
+ if (this_ctx) {
+ trace_block_unplug(this_q, depth, !from_schedule);
+ blk_mq_sched_insert_requests(this_q, this_ctx,
+ &ctx_list,
+ from_schedule);
+ }
+
+ this_ctx = rq->mq_ctx;
+ this_q = rq->q;
+ depth = 0;
+ }
+
+ depth++;
+ list_add_tail(&rq->queuelist, &ctx_list);
+ }
+
+ /*
+ * If 'this_ctx' is set, we know we have entries to complete
+ * on 'ctx_list'. Do those.
+ */
+ if (this_ctx) {
+ trace_block_unplug(this_q, depth, !from_schedule);
+ blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list,
+ from_schedule);
+ }
+}
+
+static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
+{
+ blk_init_request_from_bio(rq, bio);
+
+ blk_account_io_start(rq, true);
+}
+
+static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx)
+{
+ return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
+ !blk_queue_nomerges(hctx->queue);
+}
+
+static inline void blk_mq_queue_io(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *ctx,
+ struct request *rq)
+{
+ spin_lock(&ctx->lock);
+ __blk_mq_insert_request(hctx, rq, false);
+ spin_unlock(&ctx->lock);
+}
+
+static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq)
+{
+ if (rq->tag != -1)
+ return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false);
+
+ return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true);
+}
+
+static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
+ struct request *rq,
+ blk_qc_t *cookie, bool may_sleep)
+{
+ struct request_queue *q = rq->q;
+ struct blk_mq_queue_data bd = {
+ .rq = rq,
+ .last = true,
+ };
+ blk_qc_t new_cookie;
+ blk_status_t ret;
+ bool run_queue = true;
+
+ /* RCU or SRCU read lock is needed before checking quiesced flag */
+ if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) {
+ run_queue = false;
+ goto insert;
+ }
+
+ if (q->elevator)
+ goto insert;
+
+ if (!blk_mq_get_driver_tag(rq, NULL, false))
+ goto insert;
+
+ new_cookie = request_to_qc_t(hctx, rq);
+
+ /*
+ * For OK queue, we are done. For error, kill it. Any other
+ * error (busy), just add it to our list as we previously
+ * would have done
+ */
+ ret = q->mq_ops->queue_rq(hctx, &bd);
+ switch (ret) {
+ case BLK_STS_OK:
+ *cookie = new_cookie;
+ return;
+ case BLK_STS_RESOURCE:
+ __blk_mq_requeue_request(rq);
+ goto insert;
+ default:
+ *cookie = BLK_QC_T_NONE;
+ blk_mq_end_request(rq, ret);
+ return;
+ }
+
+insert:
+ blk_mq_sched_insert_request(rq, false, run_queue, false, may_sleep);
+}
+
+static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, blk_qc_t *cookie)
+{
+ if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
+ rcu_read_lock();
+ __blk_mq_try_issue_directly(hctx, rq, cookie, false);
+ rcu_read_unlock();
+ } else {
+ unsigned int srcu_idx;
+
+ might_sleep();
+
+ srcu_idx = srcu_read_lock(hctx->queue_rq_srcu);
+ __blk_mq_try_issue_directly(hctx, rq, cookie, true);
+ srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx);
+ }
+}
+
+static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
+{
+ const int is_sync = op_is_sync(bio->bi_opf);
+ const int is_flush_fua = op_is_flush(bio->bi_opf);
+ struct blk_mq_alloc_data data = { .flags = 0 };
+ struct request *rq;
+ unsigned int request_count = 0;
+ struct blk_plug *plug;
+ struct request *same_queue_rq = NULL;
+ blk_qc_t cookie;
+ unsigned int wb_acct;
+
+ blk_queue_bounce(q, &bio);
+
+ blk_queue_split(q, &bio);
+
+ if (!bio_integrity_prep(bio))
+ return BLK_QC_T_NONE;
+
+ if (!is_flush_fua && !blk_queue_nomerges(q) &&
+ blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
+ return BLK_QC_T_NONE;
+
+ if (blk_mq_sched_bio_merge(q, bio))
+ return BLK_QC_T_NONE;
+
+ wb_acct = wbt_wait(q->rq_wb, bio, NULL);
+
+ trace_block_getrq(q, bio, bio->bi_opf);
+
+ rq = blk_mq_get_request(q, bio, bio->bi_opf, &data);
+ if (unlikely(!rq)) {
+ __wbt_done(q->rq_wb, wb_acct);
+ if (bio->bi_opf & REQ_NOWAIT)
+ bio_wouldblock_error(bio);
+ return BLK_QC_T_NONE;
+ }
+
+ wbt_track(&rq->issue_stat, wb_acct);
+
+ cookie = request_to_qc_t(data.hctx, rq);
+
+ plug = current->plug;
+ if (unlikely(is_flush_fua)) {
+ blk_mq_put_ctx(data.ctx);
+ blk_mq_bio_to_request(rq, bio);
+ if (q->elevator) {
+ blk_mq_sched_insert_request(rq, false, true, true,
+ true);
+ } else {
+ blk_insert_flush(rq);
+ blk_mq_run_hw_queue(data.hctx, true);
+ }
+ } else if (plug && q->nr_hw_queues == 1) {
+ struct request *last = NULL;
+
+ blk_mq_put_ctx(data.ctx);
+ blk_mq_bio_to_request(rq, bio);
+
+ /*
+ * @request_count may become stale because of schedule
+ * out, so check the list again.
+ */
+ if (list_empty(&plug->mq_list))
+ request_count = 0;
+ else if (blk_queue_nomerges(q))
+ request_count = blk_plug_queued_count(q);
+
+ if (!request_count)
+ trace_block_plug(q);
+ else
+ last = list_entry_rq(plug->mq_list.prev);
+
+ if (request_count >= BLK_MAX_REQUEST_COUNT || (last &&
+ blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) {
+ blk_flush_plug_list(plug, false);
+ trace_block_plug(q);
+ }
+
+ list_add_tail(&rq->queuelist, &plug->mq_list);
+ } else if (plug && !blk_queue_nomerges(q)) {
+ blk_mq_bio_to_request(rq, bio);
+
+ /*
+ * We do limited plugging. If the bio can be merged, do that.
+ * Otherwise the existing request in the plug list will be
+ * issued. So the plug list will have one request at most
+ * The plug list might get flushed before this. If that happens,
+ * the plug list is empty, and same_queue_rq is invalid.
+ */
+ if (list_empty(&plug->mq_list))
+ same_queue_rq = NULL;
+ if (same_queue_rq)
+ list_del_init(&same_queue_rq->queuelist);
+ list_add_tail(&rq->queuelist, &plug->mq_list);
+
+ blk_mq_put_ctx(data.ctx);
+
+ if (same_queue_rq) {
+ data.hctx = blk_mq_map_queue(q,
+ same_queue_rq->mq_ctx->cpu);
+ blk_mq_try_issue_directly(data.hctx, same_queue_rq,
+ &cookie);
+ }
+ } else if (q->nr_hw_queues > 1 && is_sync) {
+ blk_mq_put_ctx(data.ctx);
+ blk_mq_bio_to_request(rq, bio);
+ blk_mq_try_issue_directly(data.hctx, rq, &cookie);
+ } else if (q->elevator) {
+ blk_mq_put_ctx(data.ctx);
+ blk_mq_bio_to_request(rq, bio);
+ blk_mq_sched_insert_request(rq, false, true, true, true);
+ } else {
+ blk_mq_put_ctx(data.ctx);
+ blk_mq_bio_to_request(rq, bio);
+ blk_mq_queue_io(data.hctx, data.ctx, rq);
+ blk_mq_run_hw_queue(data.hctx, true);
+ }
+
+ return cookie;
+}
+
+void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
+ unsigned int hctx_idx)
+{
+ struct page *page;
+
+ if (tags->rqs && set->ops->exit_request) {
+ int i;
+
+ for (i = 0; i < tags->nr_tags; i++) {
+ struct request *rq = tags->static_rqs[i];
+
+ if (!rq)
+ continue;
+ set->ops->exit_request(set, rq, hctx_idx);
+ tags->static_rqs[i] = NULL;
+ }
+ }
+
+ while (!list_empty(&tags->page_list)) {
+ page = list_first_entry(&tags->page_list, struct page, lru);
+ list_del_init(&page->lru);
+ /*
+ * Remove kmemleak object previously allocated in
+ * blk_mq_init_rq_map().
+ */
+ kmemleak_free(page_address(page));
+ __free_pages(page, page->private);
+ }
+}
+
+void blk_mq_free_rq_map(struct blk_mq_tags *tags)
+{
+ kfree(tags->rqs);
+ tags->rqs = NULL;
+ kfree(tags->static_rqs);
+ tags->static_rqs = NULL;
+
+ blk_mq_free_tags(tags);
+}
+
+struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
+ unsigned int hctx_idx,
+ unsigned int nr_tags,
+ unsigned int reserved_tags)
+{
+ struct blk_mq_tags *tags;
+ int node;
+
+ node = blk_mq_hw_queue_to_node(set->mq_map, hctx_idx);
+ if (node == NUMA_NO_NODE)
+ node = set->numa_node;
+
+ tags = blk_mq_init_tags(nr_tags, reserved_tags, node,
+ BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));
+ if (!tags)
+ return NULL;
+
+ tags->rqs = kzalloc_node(nr_tags * sizeof(struct request *),
+ GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
+ node);
+ if (!tags->rqs) {
+ blk_mq_free_tags(tags);
+ return NULL;
+ }
+
+ tags->static_rqs = kzalloc_node(nr_tags * sizeof(struct request *),
+ GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
+ node);
+ if (!tags->static_rqs) {
+ kfree(tags->rqs);
+ blk_mq_free_tags(tags);
+ return NULL;
+ }
+
+ return tags;
+}
+
+static size_t order_to_size(unsigned int order)
+{
+ return (size_t)PAGE_SIZE << order;
+}
+
+int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
+ unsigned int hctx_idx, unsigned int depth)
+{
+ unsigned int i, j, entries_per_page, max_order = 4;
+ size_t rq_size, left;
+ int node;
+
+ node = blk_mq_hw_queue_to_node(set->mq_map, hctx_idx);
+ if (node == NUMA_NO_NODE)
+ node = set->numa_node;
+
+ INIT_LIST_HEAD(&tags->page_list);
+
+ /*
+ * rq_size is the size of the request plus driver payload, rounded
+ * to the cacheline size
+ */
+ rq_size = round_up(sizeof(struct request) + set->cmd_size,
+ cache_line_size());
+ left = rq_size * depth;
+
+ for (i = 0; i < depth; ) {
+ int this_order = max_order;
+ struct page *page;
+ int to_do;
+ void *p;
+
+ while (this_order && left < order_to_size(this_order - 1))
+ this_order--;
+
+ do {
+ page = alloc_pages_node(node,
+ GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO,
+ this_order);
+ if (page)
+ break;
+ if (!this_order--)
+ break;
+ if (order_to_size(this_order) < rq_size)
+ break;
+ } while (1);
+
+ if (!page)
+ goto fail;
+
+ page->private = this_order;
+ list_add_tail(&page->lru, &tags->page_list);
+
+ p = page_address(page);
+ /*
+ * Allow kmemleak to scan these pages as they contain pointers
+ * to additional allocations like via ops->init_request().
+ */
+ kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO);
+ entries_per_page = order_to_size(this_order) / rq_size;
+ to_do = min(entries_per_page, depth - i);
+ left -= to_do * rq_size;
+ for (j = 0; j < to_do; j++) {
+ struct request *rq = p;
+
+ tags->static_rqs[i] = rq;
+ if (set->ops->init_request) {
+ if (set->ops->init_request(set, rq, hctx_idx,
+ node)) {
+ tags->static_rqs[i] = NULL;
+ goto fail;
+ }
+ }
+
+ p += rq_size;
+ i++;
+ }
+ }
+ return 0;
+
+fail:
+ blk_mq_free_rqs(set, tags, hctx_idx);
+ return -ENOMEM;
+}
+
+/*
+ * 'cpu' is going away. splice any existing rq_list entries from this
+ * software queue to the hw queue dispatch list, and ensure that it
+ * gets run.
+ */
+static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node)
+{
+ struct blk_mq_hw_ctx *hctx;
+ struct blk_mq_ctx *ctx;
+ LIST_HEAD(tmp);
+
+ hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead);
+ ctx = __blk_mq_get_ctx(hctx->queue, cpu);
+
+ spin_lock(&ctx->lock);
+ if (!list_empty(&ctx->rq_list)) {
+ list_splice_init(&ctx->rq_list, &tmp);
+ blk_mq_hctx_clear_pending(hctx, ctx);
+ }
+ spin_unlock(&ctx->lock);
+
+ if (list_empty(&tmp))
+ return 0;
+
+ spin_lock(&hctx->lock);
+ list_splice_tail_init(&tmp, &hctx->dispatch);
+ spin_unlock(&hctx->lock);
+
+ blk_mq_run_hw_queue(hctx, true);
+ return 0;
+}
+
+static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx)
+{
+ cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD,
+ &hctx->cpuhp_dead);
+}
+
+/* hctx->ctxs will be freed in queue's release handler */
+static void blk_mq_exit_hctx(struct request_queue *q,
+ struct blk_mq_tag_set *set,
+ struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
+{
+ blk_mq_debugfs_unregister_hctx(hctx);
+
+ if (blk_mq_hw_queue_mapped(hctx))
+ blk_mq_tag_idle(hctx);
+
+ if (set->ops->exit_request)
+ set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx);
+
+ blk_mq_sched_exit_hctx(q, hctx, hctx_idx);
+
+ if (set->ops->exit_hctx)
+ set->ops->exit_hctx(hctx, hctx_idx);
+
+ if (hctx->flags & BLK_MQ_F_BLOCKING)
+ cleanup_srcu_struct(hctx->queue_rq_srcu);
+
+ blk_mq_remove_cpuhp(hctx);
+ blk_free_flush_queue(hctx->fq);
+ sbitmap_free(&hctx->ctx_map);
+}
+
+static void blk_mq_exit_hw_queues(struct request_queue *q,
+ struct blk_mq_tag_set *set, int nr_queue)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (i == nr_queue)
+ break;
+ blk_mq_exit_hctx(q, set, hctx, i);
+ }
+}
+
+static int blk_mq_init_hctx(struct request_queue *q,
+ struct blk_mq_tag_set *set,
+ struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
+{
+ int node;
+
+ node = hctx->numa_node;
+ if (node == NUMA_NO_NODE)
+ node = hctx->numa_node = set->numa_node;
+
+ INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
+ spin_lock_init(&hctx->lock);
+ INIT_LIST_HEAD(&hctx->dispatch);
+ hctx->queue = q;
+ hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED;
+
+ cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead);
+
+ hctx->tags = set->tags[hctx_idx];
+
+ /*
+ * Allocate space for all possible cpus to avoid allocation at
+ * runtime
+ */
+ hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
+ GFP_KERNEL, node);
+ if (!hctx->ctxs)
+ goto unregister_cpu_notifier;
+
+ if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL,
+ node))
+ goto free_ctxs;
+
+ hctx->nr_ctx = 0;
+
+ if (set->ops->init_hctx &&
+ set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
+ goto free_bitmap;
+
+ if (blk_mq_sched_init_hctx(q, hctx, hctx_idx))
+ goto exit_hctx;
+
+ hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
+ if (!hctx->fq)
+ goto sched_exit_hctx;
+
+ if (set->ops->init_request &&
+ set->ops->init_request(set, hctx->fq->flush_rq, hctx_idx,
+ node))
+ goto free_fq;
+
+ if (hctx->flags & BLK_MQ_F_BLOCKING)
+ init_srcu_struct(hctx->queue_rq_srcu);
+
+ blk_mq_debugfs_register_hctx(q, hctx);
+
+ return 0;
+
+ free_fq:
+ kfree(hctx->fq);
+ sched_exit_hctx:
+ blk_mq_sched_exit_hctx(q, hctx, hctx_idx);
+ exit_hctx:
+ if (set->ops->exit_hctx)
+ set->ops->exit_hctx(hctx, hctx_idx);
+ free_bitmap:
+ sbitmap_free(&hctx->ctx_map);
+ free_ctxs:
+ kfree(hctx->ctxs);
+ unregister_cpu_notifier:
+ blk_mq_remove_cpuhp(hctx);
+ return -1;
+}
+
+static void blk_mq_init_cpu_queues(struct request_queue *q,
+ unsigned int nr_hw_queues)
+{
+ unsigned int i;
+
+ for_each_possible_cpu(i) {
+ struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
+ struct blk_mq_hw_ctx *hctx;
+
+ __ctx->cpu = i;
+ spin_lock_init(&__ctx->lock);
+ INIT_LIST_HEAD(&__ctx->rq_list);
+ __ctx->queue = q;
+
+ /* If the cpu isn't present, the cpu is mapped to first hctx */
+ if (!cpu_present(i))
+ continue;
+
+ hctx = blk_mq_map_queue(q, i);
+
+ /*
+ * Set local node, IFF we have more than one hw queue. If
+ * not, we remain on the home node of the device
+ */
+ if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
+ hctx->numa_node = local_memory_node(cpu_to_node(i));
+ }
+}
+
+static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx)
+{
+ int ret = 0;
+
+ set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx,
+ set->queue_depth, set->reserved_tags);
+ if (!set->tags[hctx_idx])
+ return false;
+
+ ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx,
+ set->queue_depth);
+ if (!ret)
+ return true;
+
+ blk_mq_free_rq_map(set->tags[hctx_idx]);
+ set->tags[hctx_idx] = NULL;
+ return false;
+}
+
+static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set,
+ unsigned int hctx_idx)
+{
+ if (set->tags[hctx_idx]) {
+ blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx);
+ blk_mq_free_rq_map(set->tags[hctx_idx]);
+ set->tags[hctx_idx] = NULL;
+ }
+}
+
+static void blk_mq_map_swqueue(struct request_queue *q)
+{
+ unsigned int i, hctx_idx;
+ struct blk_mq_hw_ctx *hctx;
+ struct blk_mq_ctx *ctx;
+ struct blk_mq_tag_set *set = q->tag_set;
+
+ /*
+ * Avoid others reading imcomplete hctx->cpumask through sysfs
+ */
+ mutex_lock(&q->sysfs_lock);
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ cpumask_clear(hctx->cpumask);
+ hctx->nr_ctx = 0;
+ }
+
+ /*
+ * Map software to hardware queues.
+ *
+ * If the cpu isn't present, the cpu is mapped to first hctx.
+ */
+ for_each_present_cpu(i) {
+ hctx_idx = q->mq_map[i];
+ /* unmapped hw queue can be remapped after CPU topo changed */
+ if (!set->tags[hctx_idx] &&
+ !__blk_mq_alloc_rq_map(set, hctx_idx)) {
+ /*
+ * If tags initialization fail for some hctx,
+ * that hctx won't be brought online. In this
+ * case, remap the current ctx to hctx[0] which
+ * is guaranteed to always have tags allocated
+ */
+ q->mq_map[i] = 0;
+ }
+
+ ctx = per_cpu_ptr(q->queue_ctx, i);
+ hctx = blk_mq_map_queue(q, i);
+
+ cpumask_set_cpu(i, hctx->cpumask);
+ ctx->index_hw = hctx->nr_ctx;
+ hctx->ctxs[hctx->nr_ctx++] = ctx;
+ }
+
+ mutex_unlock(&q->sysfs_lock);
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ /*
+ * If no software queues are mapped to this hardware queue,
+ * disable it and free the request entries.
+ */
+ if (!hctx->nr_ctx) {
+ /* Never unmap queue 0. We need it as a
+ * fallback in case of a new remap fails
+ * allocation
+ */
+ if (i && set->tags[i])
+ blk_mq_free_map_and_requests(set, i);
+
+ hctx->tags = NULL;
+ continue;
+ }
+
+ hctx->tags = set->tags[i];
+ WARN_ON(!hctx->tags);
+
+ /*
+ * Set the map size to the number of mapped software queues.
+ * This is more accurate and more efficient than looping
+ * over all possibly mapped software queues.
+ */
+ sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx);
+
+ /*
+ * Initialize batch roundrobin counts
+ */
+ hctx->next_cpu = cpumask_first(hctx->cpumask);
+ hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
+ }
+}
+
+/*
+ * Caller needs to ensure that we're either frozen/quiesced, or that
+ * the queue isn't live yet.
+ */
+static void queue_set_hctx_shared(struct request_queue *q, bool shared)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (shared) {
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_inc(&q->shared_hctx_restart);
+ hctx->flags |= BLK_MQ_F_TAG_SHARED;
+ } else {
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_dec(&q->shared_hctx_restart);
+ hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
+ }
+ }
+}
+
+static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set,
+ bool shared)
+{
+ struct request_queue *q;
+
+ lockdep_assert_held(&set->tag_list_lock);
+
+ list_for_each_entry(q, &set->tag_list, tag_set_list) {
+ blk_mq_freeze_queue(q);
+ queue_set_hctx_shared(q, shared);
+ blk_mq_unfreeze_queue(q);
+ }
+}
+
+static void blk_mq_del_queue_tag_set(struct request_queue *q)
+{
+ struct blk_mq_tag_set *set = q->tag_set;
+
+ mutex_lock(&set->tag_list_lock);
+ list_del_rcu(&q->tag_set_list);
+ if (list_is_singular(&set->tag_list)) {
+ /* just transitioned to unshared */
+ set->flags &= ~BLK_MQ_F_TAG_SHARED;
+ /* update existing queue */
+ blk_mq_update_tag_set_depth(set, false);
+ }
+ mutex_unlock(&set->tag_list_lock);
+ synchronize_rcu();
+ INIT_LIST_HEAD(&q->tag_set_list);
+}
+
+static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
+ struct request_queue *q)
+{
+ q->tag_set = set;
+
+ mutex_lock(&set->tag_list_lock);
+
+ /* Check to see if we're transitioning to shared (from 1 to 2 queues). */
+ if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) {
+ set->flags |= BLK_MQ_F_TAG_SHARED;
+ /* update existing queue */
+ blk_mq_update_tag_set_depth(set, true);
+ }
+ if (set->flags & BLK_MQ_F_TAG_SHARED)
+ queue_set_hctx_shared(q, true);
+ list_add_tail_rcu(&q->tag_set_list, &set->tag_list);
+
+ mutex_unlock(&set->tag_list_lock);
+}
+
+/*
+ * It is the actual release handler for mq, but we do it from
+ * request queue's release handler for avoiding use-after-free
+ * and headache because q->mq_kobj shouldn't have been introduced,
+ * but we can't group ctx/kctx kobj without it.
+ */
+void blk_mq_release(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+
+ /* hctx kobj stays in hctx */
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (!hctx)
+ continue;
+ kobject_put(&hctx->kobj);
+ }
+
+ q->mq_map = NULL;
+
+ kfree(q->queue_hw_ctx);
+
+ /*
+ * release .mq_kobj and sw queue's kobject now because
+ * both share lifetime with request queue.
+ */
+ blk_mq_sysfs_deinit(q);
+
+ free_percpu(q->queue_ctx);
+}
+
+struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
+{
+ struct request_queue *uninit_q, *q;
+
+ uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);
+ if (!uninit_q)
+ return ERR_PTR(-ENOMEM);
+
+ q = blk_mq_init_allocated_queue(set, uninit_q);
+ if (IS_ERR(q))
+ blk_cleanup_queue(uninit_q);
+
+ return q;
+}
+EXPORT_SYMBOL(blk_mq_init_queue);
+
+static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set)
+{
+ int hw_ctx_size = sizeof(struct blk_mq_hw_ctx);
+
+ BUILD_BUG_ON(ALIGN(offsetof(struct blk_mq_hw_ctx, queue_rq_srcu),
+ __alignof__(struct blk_mq_hw_ctx)) !=
+ sizeof(struct blk_mq_hw_ctx));
+
+ if (tag_set->flags & BLK_MQ_F_BLOCKING)
+ hw_ctx_size += sizeof(struct srcu_struct);
+
+ return hw_ctx_size;
+}
+
+static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
+ struct request_queue *q)
+{
+ int i, j;
+ struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx;
+
+ blk_mq_sysfs_unregister(q);
+
+ /* protect against switching io scheduler */
+ mutex_lock(&q->sysfs_lock);
+ for (i = 0; i < set->nr_hw_queues; i++) {
+ int node;
+
+ if (hctxs[i])
+ continue;
+
+ node = blk_mq_hw_queue_to_node(q->mq_map, i);
+ hctxs[i] = kzalloc_node(blk_mq_hw_ctx_size(set),
+ GFP_KERNEL, node);
+ if (!hctxs[i])
+ break;
+
+ if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL,
+ node)) {
+ kfree(hctxs[i]);
+ hctxs[i] = NULL;
+ break;
+ }
+
+ atomic_set(&hctxs[i]->nr_active, 0);
+ hctxs[i]->numa_node = node;
+ hctxs[i]->queue_num = i;
+
+ if (blk_mq_init_hctx(q, set, hctxs[i], i)) {
+ free_cpumask_var(hctxs[i]->cpumask);
+ kfree(hctxs[i]);
+ hctxs[i] = NULL;
+ break;
+ }
+ blk_mq_hctx_kobj_init(hctxs[i]);
+ }
+ for (j = i; j < q->nr_hw_queues; j++) {
+ struct blk_mq_hw_ctx *hctx = hctxs[j];
+
+ if (hctx) {
+ if (hctx->tags)
+ blk_mq_free_map_and_requests(set, j);
+ blk_mq_exit_hctx(q, set, hctx, j);
+ kobject_put(&hctx->kobj);
+ hctxs[j] = NULL;
+
+ }
+ }
+ q->nr_hw_queues = i;
+ mutex_unlock(&q->sysfs_lock);
+ blk_mq_sysfs_register(q);
+}
+
+struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
+ struct request_queue *q)
+{
+ /* mark the queue as mq asap */
+ q->mq_ops = set->ops;
+
+ q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn,
+ blk_mq_poll_stats_bkt,
+ BLK_MQ_POLL_STATS_BKTS, q);
+ if (!q->poll_cb)
+ goto err_exit;
+
+ q->queue_ctx = alloc_percpu(struct blk_mq_ctx);
+ if (!q->queue_ctx)
+ goto err_exit;
+
+ /* init q->mq_kobj and sw queues' kobjects */
+ blk_mq_sysfs_init(q);
+
+ q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)),
+ GFP_KERNEL, set->numa_node);
+ if (!q->queue_hw_ctx)
+ goto err_percpu;
+
+ q->mq_map = set->mq_map;
+
+ blk_mq_realloc_hw_ctxs(set, q);
+ if (!q->nr_hw_queues)
+ goto err_hctxs;
+
+ INIT_WORK(&q->timeout_work, blk_mq_timeout_work);
+ blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);
+
+ q->nr_queues = nr_cpu_ids;
+
+ q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
+
+ if (!(set->flags & BLK_MQ_F_SG_MERGE))
+ q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE;
+
+ q->sg_reserved_size = INT_MAX;
+
+ INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);
+ INIT_LIST_HEAD(&q->requeue_list);
+ spin_lock_init(&q->requeue_lock);
+
+ blk_queue_make_request(q, blk_mq_make_request);
+
+ /*
+ * Do this after blk_queue_make_request() overrides it...
+ */
+ q->nr_requests = set->queue_depth;
+
+ /*
+ * Default to classic polling
+ */
+ q->poll_nsec = -1;
+
+ if (set->ops->complete)
+ blk_queue_softirq_done(q, set->ops->complete);
+
+ blk_mq_init_cpu_queues(q, set->nr_hw_queues);
+ blk_mq_add_queue_tag_set(set, q);
+ blk_mq_map_swqueue(q);
+
+ if (!(set->flags & BLK_MQ_F_NO_SCHED)) {
+ int ret;
+
+ ret = blk_mq_sched_init(q);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ return q;
+
+err_hctxs:
+ kfree(q->queue_hw_ctx);
+err_percpu:
+ free_percpu(q->queue_ctx);
+err_exit:
+ q->mq_ops = NULL;
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL(blk_mq_init_allocated_queue);
+
+void blk_mq_free_queue(struct request_queue *q)
+{
+ struct blk_mq_tag_set *set = q->tag_set;
+
+ blk_mq_del_queue_tag_set(q);
+ blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
+}
+
+/* Basically redo blk_mq_init_queue with queue frozen */
+static void blk_mq_queue_reinit(struct request_queue *q)
+{
+ WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth));
+
+ blk_mq_debugfs_unregister_hctxs(q);
+ blk_mq_sysfs_unregister(q);
+
+ /*
+ * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe
+ * we should change hctx numa_node according to new topology (this
+ * involves free and re-allocate memory, worthy doing?)
+ */
+
+ blk_mq_map_swqueue(q);
+
+ blk_mq_sysfs_register(q);
+ blk_mq_debugfs_register_hctxs(q);
+}
+
+static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
+{
+ int i;
+
+ for (i = 0; i < set->nr_hw_queues; i++)
+ if (!__blk_mq_alloc_rq_map(set, i))
+ goto out_unwind;
+
+ return 0;
+
+out_unwind:
+ while (--i >= 0)
+ blk_mq_free_rq_map(set->tags[i]);
+
+ return -ENOMEM;
+}
+
+/*
+ * Allocate the request maps associated with this tag_set. Note that this
+ * may reduce the depth asked for, if memory is tight. set->queue_depth
+ * will be updated to reflect the allocated depth.
+ */
+static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
+{
+ unsigned int depth;
+ int err;
+
+ depth = set->queue_depth;
+ do {
+ err = __blk_mq_alloc_rq_maps(set);
+ if (!err)
+ break;
+
+ set->queue_depth >>= 1;
+ if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
+ err = -ENOMEM;
+ break;
+ }
+ } while (set->queue_depth);
+
+ if (!set->queue_depth || err) {
+ pr_err("blk-mq: failed to allocate request map\n");
+ return -ENOMEM;
+ }
+
+ if (depth != set->queue_depth)
+ pr_info("blk-mq: reduced tag depth (%u -> %u)\n",
+ depth, set->queue_depth);
+
+ return 0;
+}
+
+static int blk_mq_update_queue_map(struct blk_mq_tag_set *set)
+{
+ if (set->ops->map_queues) {
+ int cpu;
+ /*
+ * transport .map_queues is usually done in the following
+ * way:
+ *
+ * for (queue = 0; queue < set->nr_hw_queues; queue++) {
+ * mask = get_cpu_mask(queue)
+ * for_each_cpu(cpu, mask)
+ * set->mq_map[cpu] = queue;
+ * }
+ *
+ * When we need to remap, the table has to be cleared for
+ * killing stale mapping since one CPU may not be mapped
+ * to any hw queue.
+ */
+ for_each_possible_cpu(cpu)
+ set->mq_map[cpu] = 0;
+
+ return set->ops->map_queues(set);
+ } else
+ return blk_mq_map_queues(set);
+}
+
+/*
+ * Alloc a tag set to be associated with one or more request queues.
+ * May fail with EINVAL for various error conditions. May adjust the
+ * requested depth down, if if it too large. In that case, the set
+ * value will be stored in set->queue_depth.
+ */
+int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
+{
+ int ret;
+
+ BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS);
+
+ if (!set->nr_hw_queues)
+ return -EINVAL;
+ if (!set->queue_depth)
+ return -EINVAL;
+ if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
+ return -EINVAL;
+
+ if (!set->ops->queue_rq)
+ return -EINVAL;
+
+ if (set->queue_depth > BLK_MQ_MAX_DEPTH) {
+ pr_info("blk-mq: reduced tag depth to %u\n",
+ BLK_MQ_MAX_DEPTH);
+ set->queue_depth = BLK_MQ_MAX_DEPTH;
+ }
+
+ /*
+ * If a crashdump is active, then we are potentially in a very
+ * memory constrained environment. Limit us to 1 queue and
+ * 64 tags to prevent using too much memory.
+ */
+ if (is_kdump_kernel()) {
+ set->nr_hw_queues = 1;
+ set->queue_depth = min(64U, set->queue_depth);
+ }
+ /*
+ * There is no use for more h/w queues than cpus.
+ */
+ if (set->nr_hw_queues > nr_cpu_ids)
+ set->nr_hw_queues = nr_cpu_ids;
+
+ set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *),
+ GFP_KERNEL, set->numa_node);
+ if (!set->tags)
+ return -ENOMEM;
+
+ ret = -ENOMEM;
+ set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids,
+ GFP_KERNEL, set->numa_node);
+ if (!set->mq_map)
+ goto out_free_tags;
+
+ ret = blk_mq_update_queue_map(set);
+ if (ret)
+ goto out_free_mq_map;
+
+ ret = blk_mq_alloc_rq_maps(set);
+ if (ret)
+ goto out_free_mq_map;
+
+ mutex_init(&set->tag_list_lock);
+ INIT_LIST_HEAD(&set->tag_list);
+
+ return 0;
+
+out_free_mq_map:
+ kfree(set->mq_map);
+ set->mq_map = NULL;
+out_free_tags:
+ kfree(set->tags);
+ set->tags = NULL;
+ return ret;
+}
+EXPORT_SYMBOL(blk_mq_alloc_tag_set);
+
+void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
+{
+ int i;
+
+ for (i = 0; i < nr_cpu_ids; i++)
+ blk_mq_free_map_and_requests(set, i);
+
+ kfree(set->mq_map);
+ set->mq_map = NULL;
+
+ kfree(set->tags);
+ set->tags = NULL;
+}
+EXPORT_SYMBOL(blk_mq_free_tag_set);
+
+int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
+{
+ struct blk_mq_tag_set *set = q->tag_set;
+ struct blk_mq_hw_ctx *hctx;
+ int i, ret;
+
+ if (!set)
+ return -EINVAL;
+
+ blk_mq_freeze_queue(q);
+
+ ret = 0;
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (!hctx->tags)
+ continue;
+ /*
+ * If we're using an MQ scheduler, just update the scheduler
+ * queue depth. This is similar to what the old code would do.
+ */
+ if (!hctx->sched_tags) {
+ ret = blk_mq_tag_update_depth(hctx, &hctx->tags,
+ min(nr, set->queue_depth),
+ false);
+ } else {
+ ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags,
+ nr, true);
+ }
+ if (ret)
+ break;
+ }
+
+ if (!ret)
+ q->nr_requests = nr;
+
+ blk_mq_unfreeze_queue(q);
+
+ return ret;
+}
+
+static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
+ int nr_hw_queues)
+{
+ struct request_queue *q;
+
+ lockdep_assert_held(&set->tag_list_lock);
+
+ if (nr_hw_queues > nr_cpu_ids)
+ nr_hw_queues = nr_cpu_ids;
+ if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues)
+ return;
+
+ list_for_each_entry(q, &set->tag_list, tag_set_list)
+ blk_mq_freeze_queue(q);
+ /*
+ * Sync with blk_mq_queue_tag_busy_iter.
+ */
+ synchronize_rcu();
+
+ set->nr_hw_queues = nr_hw_queues;
+ blk_mq_update_queue_map(set);
+ list_for_each_entry(q, &set->tag_list, tag_set_list) {
+ blk_mq_realloc_hw_ctxs(set, q);
+ blk_mq_queue_reinit(q);
+ }
+
+ list_for_each_entry(q, &set->tag_list, tag_set_list)
+ blk_mq_unfreeze_queue(q);
+}
+
+void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
+{
+ mutex_lock(&set->tag_list_lock);
+ __blk_mq_update_nr_hw_queues(set, nr_hw_queues);
+ mutex_unlock(&set->tag_list_lock);
+}
+EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
+
+/* Enable polling stats and return whether they were already enabled. */
+static bool blk_poll_stats_enable(struct request_queue *q)
+{
+ if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) ||
+ test_and_set_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
+ return true;
+ blk_stat_add_callback(q, q->poll_cb);
+ return false;
+}
+
+static void blk_mq_poll_stats_start(struct request_queue *q)
+{
+ /*
+ * We don't arm the callback if polling stats are not enabled or the
+ * callback is already active.
+ */
+ if (!test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) ||
+ blk_stat_is_active(q->poll_cb))
+ return;
+
+ blk_stat_activate_msecs(q->poll_cb, 100);
+}
+
+static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb)
+{
+ struct request_queue *q = cb->data;
+ int bucket;
+
+ for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS; bucket++) {
+ if (cb->stat[bucket].nr_samples)
+ q->poll_stat[bucket] = cb->stat[bucket];
+ }
+}
+
+static unsigned long blk_mq_poll_nsecs(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx,
+ struct request *rq)
+{
+ unsigned long ret = 0;
+ int bucket;
+
+ /*
+ * If stats collection isn't on, don't sleep but turn it on for
+ * future users
+ */
+ if (!blk_poll_stats_enable(q))
+ return 0;
+
+ /*
+ * As an optimistic guess, use half of the mean service time
+ * for this type of request. We can (and should) make this smarter.
+ * For instance, if the completion latencies are tight, we can
+ * get closer than just half the mean. This is especially
+ * important on devices where the completion latencies are longer
+ * than ~10 usec. We do use the stats for the relevant IO size
+ * if available which does lead to better estimates.
+ */
+ bucket = blk_mq_poll_stats_bkt(rq);
+ if (bucket < 0)
+ return ret;
+
+ if (q->poll_stat[bucket].nr_samples)
+ ret = (q->poll_stat[bucket].mean + 1) / 2;
+
+ return ret;
+}
+
+static bool blk_mq_poll_hybrid_sleep(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx,
+ struct request *rq)
+{
+ struct hrtimer_sleeper hs;
+ enum hrtimer_mode mode;
+ unsigned int nsecs;
+ ktime_t kt;
+
+ if (test_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags))
+ return false;
+
+ /*
+ * poll_nsec can be:
+ *
+ * -1: don't ever hybrid sleep
+ * 0: use half of prev avg
+ * >0: use this specific value
+ */
+ if (q->poll_nsec == -1)
+ return false;
+ else if (q->poll_nsec > 0)
+ nsecs = q->poll_nsec;
+ else
+ nsecs = blk_mq_poll_nsecs(q, hctx, rq);
+
+ if (!nsecs)
+ return false;
+
+ set_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags);
+
+ /*
+ * This will be replaced with the stats tracking code, using
+ * 'avg_completion_time / 2' as the pre-sleep target.
+ */
+ kt = nsecs;
+
+ mode = HRTIMER_MODE_REL;
+ hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode);
+ hrtimer_set_expires(&hs.timer, kt);
+
+ hrtimer_init_sleeper(&hs, current);
+ do {
+ if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags))
+ break;
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ hrtimer_start_expires(&hs.timer, mode);
+ if (hs.task)
+ io_schedule();
+ hrtimer_cancel(&hs.timer);
+ mode = HRTIMER_MODE_ABS;
+ } while (hs.task && !signal_pending(current));
+
+ __set_current_state(TASK_RUNNING);
+ destroy_hrtimer_on_stack(&hs.timer);
+ return true;
+}
+
+static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
+{
+ struct request_queue *q = hctx->queue;
+ long state;
+
+ /*
+ * If we sleep, have the caller restart the poll loop to reset
+ * the state. Like for the other success return cases, the
+ * caller is responsible for checking if the IO completed. If
+ * the IO isn't complete, we'll get called again and will go
+ * straight to the busy poll loop.
+ */
+ if (blk_mq_poll_hybrid_sleep(q, hctx, rq))
+ return true;
+
+ hctx->poll_considered++;
+
+ state = current->state;
+ while (!need_resched()) {
+ int ret;
+
+ hctx->poll_invoked++;
+
+ ret = q->mq_ops->poll(hctx, rq->tag);
+ if (ret > 0) {
+ hctx->poll_success++;
+ set_current_state(TASK_RUNNING);
+ return true;
+ }
+
+ if (signal_pending_state(state, current))
+ set_current_state(TASK_RUNNING);
+
+ if (current->state == TASK_RUNNING)
+ return true;
+ if (ret < 0)
+ break;
+ cpu_relax();
+ }
+
+ return false;
+}
+
+bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
+{
+ struct blk_mq_hw_ctx *hctx;
+ struct blk_plug *plug;
+ struct request *rq;
+
+ if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) ||
+ !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
+ return false;
+
+ plug = current->plug;
+ if (plug)
+ blk_flush_plug_list(plug, false);
+
+ hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)];
+ if (!blk_qc_t_is_internal(cookie))
+ rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
+ else {
+ rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie));
+ /*
+ * With scheduling, if the request has completed, we'll
+ * get a NULL return here, as we clear the sched tag when
+ * that happens. The request still remains valid, like always,
+ * so we should be safe with just the NULL check.
+ */
+ if (!rq)
+ return false;
+ }
+
+ return __blk_mq_poll(hctx, rq);
+}
+EXPORT_SYMBOL_GPL(blk_mq_poll);
+
+static int __init blk_mq_init(void)
+{
+ cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL,
+ blk_mq_hctx_notify_dead);
+ return 0;
+}
+subsys_initcall(blk_mq_init);
diff --git a/src/kernel/linux/v4.14/block/blk-mq.h b/src/kernel/linux/v4.14/block/blk-mq.h
new file mode 100644
index 0000000..877237e
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-mq.h
@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef INT_BLK_MQ_H
+#define INT_BLK_MQ_H
+
+#include "blk-stat.h"
+
+struct blk_mq_tag_set;
+
+struct blk_mq_ctx {
+ struct {
+ spinlock_t lock;
+ struct list_head rq_list;
+ } ____cacheline_aligned_in_smp;
+
+ unsigned int cpu;
+ unsigned int index_hw;
+
+ /* incremented at dispatch time */
+ unsigned long rq_dispatched[2];
+ unsigned long rq_merged;
+
+ /* incremented at completion time */
+ unsigned long ____cacheline_aligned_in_smp rq_completed[2];
+
+ struct request_queue *queue;
+ struct kobject kobj;
+} ____cacheline_aligned_in_smp;
+
+void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
+void blk_mq_freeze_queue(struct request_queue *q);
+void blk_mq_free_queue(struct request_queue *q);
+int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
+void blk_mq_wake_waiters(struct request_queue *q);
+bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *);
+void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
+bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx);
+bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
+ bool wait);
+
+/*
+ * Internal helpers for allocating/freeing the request map
+ */
+void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
+ unsigned int hctx_idx);
+void blk_mq_free_rq_map(struct blk_mq_tags *tags);
+struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
+ unsigned int hctx_idx,
+ unsigned int nr_tags,
+ unsigned int reserved_tags);
+int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
+ unsigned int hctx_idx, unsigned int depth);
+
+/*
+ * Internal helpers for request insertion into sw queues
+ */
+void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
+ bool at_head);
+void blk_mq_request_bypass_insert(struct request *rq);
+void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+ struct list_head *list);
+
+/*
+ * CPU -> queue mappings
+ */
+extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
+
+static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
+ int cpu)
+{
+ return q->queue_hw_ctx[q->mq_map[cpu]];
+}
+
+/*
+ * sysfs helpers
+ */
+extern void blk_mq_sysfs_init(struct request_queue *q);
+extern void blk_mq_sysfs_deinit(struct request_queue *q);
+extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
+extern int blk_mq_sysfs_register(struct request_queue *q);
+extern void blk_mq_sysfs_unregister(struct request_queue *q);
+extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
+
+extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
+
+void blk_mq_release(struct request_queue *q);
+
+static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
+ unsigned int cpu)
+{
+ return per_cpu_ptr(q->queue_ctx, cpu);
+}
+
+/*
+ * This assumes per-cpu software queueing queues. They could be per-node
+ * as well, for instance. For now this is hardcoded as-is. Note that we don't
+ * care about preemption, since we know the ctx's are persistent. This does
+ * mean that we can't rely on ctx always matching the currently running CPU.
+ */
+static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
+{
+ return __blk_mq_get_ctx(q, get_cpu());
+}
+
+static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
+{
+ put_cpu();
+}
+
+struct blk_mq_alloc_data {
+ /* input parameter */
+ struct request_queue *q;
+ unsigned int flags;
+ unsigned int shallow_depth;
+
+ /* input & output parameter */
+ struct blk_mq_ctx *ctx;
+ struct blk_mq_hw_ctx *hctx;
+};
+
+static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
+{
+ if (data->flags & BLK_MQ_REQ_INTERNAL)
+ return data->hctx->sched_tags;
+
+ return data->hctx->tags;
+}
+
+static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
+{
+ return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
+}
+
+static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
+{
+ return hctx->nr_ctx && hctx->tags;
+}
+
+void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
+ unsigned int inflight[2]);
+void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+ unsigned int inflight[2]);
+
+#endif
diff --git a/src/kernel/linux/v4.14/block/blk-settings.c b/src/kernel/linux/v4.14/block/blk-settings.c
new file mode 100644
index 0000000..e0a7449
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-settings.c
@@ -0,0 +1,918 @@
+/*
+ * Functions related to setting various queue properties from drivers
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/bootmem.h> /* for max_pfn/max_low_pfn */
+#include <linux/gcd.h>
+#include <linux/lcm.h>
+#include <linux/jiffies.h>
+#include <linux/gfp.h>
+
+#include "blk.h"
+#include "blk-wbt.h"
+
+unsigned long blk_max_low_pfn;
+EXPORT_SYMBOL(blk_max_low_pfn);
+
+unsigned long blk_max_pfn;
+
+/**
+ * blk_queue_prep_rq - set a prepare_request function for queue
+ * @q: queue
+ * @pfn: prepare_request function
+ *
+ * It's possible for a queue to register a prepare_request callback which
+ * is invoked before the request is handed to the request_fn. The goal of
+ * the function is to prepare a request for I/O, it can be used to build a
+ * cdb from the request data for instance.
+ *
+ */
+void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn)
+{
+ q->prep_rq_fn = pfn;
+}
+EXPORT_SYMBOL(blk_queue_prep_rq);
+
+/**
+ * blk_queue_unprep_rq - set an unprepare_request function for queue
+ * @q: queue
+ * @ufn: unprepare_request function
+ *
+ * It's possible for a queue to register an unprepare_request callback
+ * which is invoked before the request is finally completed. The goal
+ * of the function is to deallocate any data that was allocated in the
+ * prepare_request callback.
+ *
+ */
+void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *ufn)
+{
+ q->unprep_rq_fn = ufn;
+}
+EXPORT_SYMBOL(blk_queue_unprep_rq);
+
+void blk_queue_softirq_done(struct request_queue *q, softirq_done_fn *fn)
+{
+ q->softirq_done_fn = fn;
+}
+EXPORT_SYMBOL(blk_queue_softirq_done);
+
+void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
+{
+ q->rq_timeout = timeout;
+}
+EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
+
+void blk_queue_rq_timed_out(struct request_queue *q, rq_timed_out_fn *fn)
+{
+ WARN_ON_ONCE(q->mq_ops);
+ q->rq_timed_out_fn = fn;
+}
+EXPORT_SYMBOL_GPL(blk_queue_rq_timed_out);
+
+void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn)
+{
+ q->lld_busy_fn = fn;
+}
+EXPORT_SYMBOL_GPL(blk_queue_lld_busy);
+
+/**
+ * blk_set_default_limits - reset limits to default values
+ * @lim: the queue_limits structure to reset
+ *
+ * Description:
+ * Returns a queue_limit struct to its default state.
+ */
+void blk_set_default_limits(struct queue_limits *lim)
+{
+ lim->max_segments = BLK_MAX_SEGMENTS;
+ lim->max_discard_segments = 1;
+ lim->max_integrity_segments = 0;
+ lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
+ lim->virt_boundary_mask = 0;
+ lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
+ lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
+ lim->max_dev_sectors = 0;
+ lim->chunk_sectors = 0;
+ lim->max_write_same_sectors = 0;
+ lim->max_write_zeroes_sectors = 0;
+ lim->max_discard_sectors = 0;
+ lim->max_hw_discard_sectors = 0;
+ lim->discard_granularity = 0;
+ lim->discard_alignment = 0;
+ lim->discard_misaligned = 0;
+ lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
+ lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT);
+ lim->alignment_offset = 0;
+ lim->io_opt = 0;
+ lim->misaligned = 0;
+ lim->cluster = 1;
+ lim->zoned = BLK_ZONED_NONE;
+}
+EXPORT_SYMBOL(blk_set_default_limits);
+
+/**
+ * blk_set_stacking_limits - set default limits for stacking devices
+ * @lim: the queue_limits structure to reset
+ *
+ * Description:
+ * Returns a queue_limit struct to its default state. Should be used
+ * by stacking drivers like DM that have no internal limits.
+ */
+void blk_set_stacking_limits(struct queue_limits *lim)
+{
+ blk_set_default_limits(lim);
+
+ /* Inherit limits from component devices */
+ lim->max_segments = USHRT_MAX;
+ lim->max_discard_segments = USHRT_MAX;
+ lim->max_hw_sectors = UINT_MAX;
+ lim->max_segment_size = UINT_MAX;
+ lim->max_sectors = UINT_MAX;
+ lim->max_dev_sectors = UINT_MAX;
+ lim->max_write_same_sectors = UINT_MAX;
+ lim->max_write_zeroes_sectors = UINT_MAX;
+}
+EXPORT_SYMBOL(blk_set_stacking_limits);
+
+/**
+ * blk_queue_make_request - define an alternate make_request function for a device
+ * @q: the request queue for the device to be affected
+ * @mfn: the alternate make_request function
+ *
+ * Description:
+ * The normal way for &struct bios to be passed to a device
+ * driver is for them to be collected into requests on a request
+ * queue, and then to allow the device driver to select requests
+ * off that queue when it is ready. This works well for many block
+ * devices. However some block devices (typically virtual devices
+ * such as md or lvm) do not benefit from the processing on the
+ * request queue, and are served best by having the requests passed
+ * directly to them. This can be achieved by providing a function
+ * to blk_queue_make_request().
+ *
+ * Caveat:
+ * The driver that does this *must* be able to deal appropriately
+ * with buffers in "highmemory". This can be accomplished by either calling
+ * __bio_kmap_atomic() to get a temporary kernel mapping, or by calling
+ * blk_queue_bounce() to create a buffer in normal memory.
+ **/
+void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
+{
+ /*
+ * set defaults
+ */
+ q->nr_requests = BLKDEV_MAX_RQ;
+
+ q->make_request_fn = mfn;
+ blk_queue_dma_alignment(q, 511);
+ blk_queue_congestion_threshold(q);
+ q->nr_batching = BLK_BATCH_REQ;
+
+ blk_set_default_limits(&q->limits);
+}
+EXPORT_SYMBOL(blk_queue_make_request);
+
+/**
+ * blk_queue_bounce_limit - set bounce buffer limit for queue
+ * @q: the request queue for the device
+ * @max_addr: the maximum address the device can handle
+ *
+ * Description:
+ * Different hardware can have different requirements as to what pages
+ * it can do I/O directly to. A low level driver can call
+ * blk_queue_bounce_limit to have lower memory pages allocated as bounce
+ * buffers for doing I/O to pages residing above @max_addr.
+ **/
+void blk_queue_bounce_limit(struct request_queue *q, u64 max_addr)
+{
+ unsigned long b_pfn = max_addr >> PAGE_SHIFT;
+ int dma = 0;
+
+ q->bounce_gfp = GFP_NOIO;
+#if BITS_PER_LONG == 64
+ /*
+ * Assume anything <= 4GB can be handled by IOMMU. Actually
+ * some IOMMUs can handle everything, but I don't know of a
+ * way to test this here.
+ */
+ if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
+ dma = 1;
+ q->limits.bounce_pfn = max(max_low_pfn, b_pfn);
+#else
+ if (b_pfn < blk_max_low_pfn)
+ dma = 1;
+ q->limits.bounce_pfn = b_pfn;
+#endif
+ if (dma) {
+ init_emergency_isa_pool();
+ q->bounce_gfp = GFP_NOIO | GFP_DMA;
+ q->limits.bounce_pfn = b_pfn;
+ }
+}
+EXPORT_SYMBOL(blk_queue_bounce_limit);
+
+/**
+ * blk_queue_max_hw_sectors - set max sectors for a request for this queue
+ * @q: the request queue for the device
+ * @max_hw_sectors: max hardware sectors in the usual 512b unit
+ *
+ * Description:
+ * Enables a low level driver to set a hard upper limit,
+ * max_hw_sectors, on the size of requests. max_hw_sectors is set by
+ * the device driver based upon the capabilities of the I/O
+ * controller.
+ *
+ * max_dev_sectors is a hard limit imposed by the storage device for
+ * READ/WRITE requests. It is set by the disk driver.
+ *
+ * max_sectors is a soft limit imposed by the block layer for
+ * filesystem type requests. This value can be overridden on a
+ * per-device basis in /sys/block/<device>/queue/max_sectors_kb.
+ * The soft limit can not exceed max_hw_sectors.
+ **/
+void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
+{
+ struct queue_limits *limits = &q->limits;
+ unsigned int max_sectors;
+
+ if ((max_hw_sectors << 9) < PAGE_SIZE) {
+ max_hw_sectors = 1 << (PAGE_SHIFT - 9);
+ printk(KERN_INFO "%s: set to minimum %d\n",
+ __func__, max_hw_sectors);
+ }
+
+ limits->max_hw_sectors = max_hw_sectors;
+ max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
+ max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS);
+ limits->max_sectors = max_sectors;
+ q->backing_dev_info->io_pages = max_sectors >> (PAGE_SHIFT - 9);
+}
+EXPORT_SYMBOL(blk_queue_max_hw_sectors);
+
+/**
+ * blk_queue_chunk_sectors - set size of the chunk for this queue
+ * @q: the request queue for the device
+ * @chunk_sectors: chunk sectors in the usual 512b unit
+ *
+ * Description:
+ * If a driver doesn't want IOs to cross a given chunk size, it can set
+ * this limit and prevent merging across chunks. Note that the chunk size
+ * must currently be a power-of-2 in sectors. Also note that the block
+ * layer must accept a page worth of data at any offset. So if the
+ * crossing of chunks is a hard limitation in the driver, it must still be
+ * prepared to split single page bios.
+ **/
+void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)
+{
+ BUG_ON(!is_power_of_2(chunk_sectors));
+ q->limits.chunk_sectors = chunk_sectors;
+}
+EXPORT_SYMBOL(blk_queue_chunk_sectors);
+
+/**
+ * blk_queue_max_discard_sectors - set max sectors for a single discard
+ * @q: the request queue for the device
+ * @max_discard_sectors: maximum number of sectors to discard
+ **/
+void blk_queue_max_discard_sectors(struct request_queue *q,
+ unsigned int max_discard_sectors)
+{
+ q->limits.max_hw_discard_sectors = max_discard_sectors;
+ q->limits.max_discard_sectors = max_discard_sectors;
+}
+EXPORT_SYMBOL(blk_queue_max_discard_sectors);
+
+/**
+ * blk_queue_max_write_same_sectors - set max sectors for a single write same
+ * @q: the request queue for the device
+ * @max_write_same_sectors: maximum number of sectors to write per command
+ **/
+void blk_queue_max_write_same_sectors(struct request_queue *q,
+ unsigned int max_write_same_sectors)
+{
+ q->limits.max_write_same_sectors = max_write_same_sectors;
+}
+EXPORT_SYMBOL(blk_queue_max_write_same_sectors);
+
+/**
+ * blk_queue_max_write_zeroes_sectors - set max sectors for a single
+ * write zeroes
+ * @q: the request queue for the device
+ * @max_write_zeroes_sectors: maximum number of sectors to write per command
+ **/
+void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
+ unsigned int max_write_zeroes_sectors)
+{
+ q->limits.max_write_zeroes_sectors = max_write_zeroes_sectors;
+}
+EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors);
+
+/**
+ * blk_queue_max_segments - set max hw segments for a request for this queue
+ * @q: the request queue for the device
+ * @max_segments: max number of segments
+ *
+ * Description:
+ * Enables a low level driver to set an upper limit on the number of
+ * hw data segments in a request.
+ **/
+void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
+{
+ if (!max_segments) {
+ max_segments = 1;
+ printk(KERN_INFO "%s: set to minimum %d\n",
+ __func__, max_segments);
+ }
+
+ q->limits.max_segments = max_segments;
+}
+EXPORT_SYMBOL(blk_queue_max_segments);
+
+/**
+ * blk_queue_max_discard_segments - set max segments for discard requests
+ * @q: the request queue for the device
+ * @max_segments: max number of segments
+ *
+ * Description:
+ * Enables a low level driver to set an upper limit on the number of
+ * segments in a discard request.
+ **/
+void blk_queue_max_discard_segments(struct request_queue *q,
+ unsigned short max_segments)
+{
+ q->limits.max_discard_segments = max_segments;
+}
+EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments);
+
+/**
+ * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
+ * @q: the request queue for the device
+ * @max_size: max size of segment in bytes
+ *
+ * Description:
+ * Enables a low level driver to set an upper limit on the size of a
+ * coalesced segment
+ **/
+void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
+{
+ if (max_size < PAGE_SIZE) {
+ max_size = PAGE_SIZE;
+ printk(KERN_INFO "%s: set to minimum %d\n",
+ __func__, max_size);
+ }
+
+ q->limits.max_segment_size = max_size;
+}
+EXPORT_SYMBOL(blk_queue_max_segment_size);
+
+/**
+ * blk_queue_logical_block_size - set logical block size for the queue
+ * @q: the request queue for the device
+ * @size: the logical block size, in bytes
+ *
+ * Description:
+ * This should be set to the lowest possible block size that the
+ * storage device can address. The default of 512 covers most
+ * hardware.
+ **/
+void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
+{
+ q->limits.logical_block_size = size;
+
+ if (q->limits.physical_block_size < size)
+ q->limits.physical_block_size = size;
+
+ if (q->limits.io_min < q->limits.physical_block_size)
+ q->limits.io_min = q->limits.physical_block_size;
+}
+EXPORT_SYMBOL(blk_queue_logical_block_size);
+
+/**
+ * blk_queue_physical_block_size - set physical block size for the queue
+ * @q: the request queue for the device
+ * @size: the physical block size, in bytes
+ *
+ * Description:
+ * This should be set to the lowest possible sector size that the
+ * hardware can operate on without reverting to read-modify-write
+ * operations.
+ */
+void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
+{
+ q->limits.physical_block_size = size;
+
+ if (q->limits.physical_block_size < q->limits.logical_block_size)
+ q->limits.physical_block_size = q->limits.logical_block_size;
+
+ if (q->limits.io_min < q->limits.physical_block_size)
+ q->limits.io_min = q->limits.physical_block_size;
+}
+EXPORT_SYMBOL(blk_queue_physical_block_size);
+
+/**
+ * blk_queue_alignment_offset - set physical block alignment offset
+ * @q: the request queue for the device
+ * @offset: alignment offset in bytes
+ *
+ * Description:
+ * Some devices are naturally misaligned to compensate for things like
+ * the legacy DOS partition table 63-sector offset. Low-level drivers
+ * should call this function for devices whose first sector is not
+ * naturally aligned.
+ */
+void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
+{
+ q->limits.alignment_offset =
+ offset & (q->limits.physical_block_size - 1);
+ q->limits.misaligned = 0;
+}
+EXPORT_SYMBOL(blk_queue_alignment_offset);
+
+/**
+ * blk_limits_io_min - set minimum request size for a device
+ * @limits: the queue limits
+ * @min: smallest I/O size in bytes
+ *
+ * Description:
+ * Some devices have an internal block size bigger than the reported
+ * hardware sector size. This function can be used to signal the
+ * smallest I/O the device can perform without incurring a performance
+ * penalty.
+ */
+void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
+{
+ limits->io_min = min;
+
+ if (limits->io_min < limits->logical_block_size)
+ limits->io_min = limits->logical_block_size;
+
+ if (limits->io_min < limits->physical_block_size)
+ limits->io_min = limits->physical_block_size;
+}
+EXPORT_SYMBOL(blk_limits_io_min);
+
+/**
+ * blk_queue_io_min - set minimum request size for the queue
+ * @q: the request queue for the device
+ * @min: smallest I/O size in bytes
+ *
+ * Description:
+ * Storage devices may report a granularity or preferred minimum I/O
+ * size which is the smallest request the device can perform without
+ * incurring a performance penalty. For disk drives this is often the
+ * physical block size. For RAID arrays it is often the stripe chunk
+ * size. A properly aligned multiple of minimum_io_size is the
+ * preferred request size for workloads where a high number of I/O
+ * operations is desired.
+ */
+void blk_queue_io_min(struct request_queue *q, unsigned int min)
+{
+ blk_limits_io_min(&q->limits, min);
+}
+EXPORT_SYMBOL(blk_queue_io_min);
+
+/**
+ * blk_limits_io_opt - set optimal request size for a device
+ * @limits: the queue limits
+ * @opt: smallest I/O size in bytes
+ *
+ * Description:
+ * Storage devices may report an optimal I/O size, which is the
+ * device's preferred unit for sustained I/O. This is rarely reported
+ * for disk drives. For RAID arrays it is usually the stripe width or
+ * the internal track size. A properly aligned multiple of
+ * optimal_io_size is the preferred request size for workloads where
+ * sustained throughput is desired.
+ */
+void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt)
+{
+ limits->io_opt = opt;
+}
+EXPORT_SYMBOL(blk_limits_io_opt);
+
+/**
+ * blk_queue_io_opt - set optimal request size for the queue
+ * @q: the request queue for the device
+ * @opt: optimal request size in bytes
+ *
+ * Description:
+ * Storage devices may report an optimal I/O size, which is the
+ * device's preferred unit for sustained I/O. This is rarely reported
+ * for disk drives. For RAID arrays it is usually the stripe width or
+ * the internal track size. A properly aligned multiple of
+ * optimal_io_size is the preferred request size for workloads where
+ * sustained throughput is desired.
+ */
+void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
+{
+ blk_limits_io_opt(&q->limits, opt);
+}
+EXPORT_SYMBOL(blk_queue_io_opt);
+
+/**
+ * blk_queue_stack_limits - inherit underlying queue limits for stacked drivers
+ * @t: the stacking driver (top)
+ * @b: the underlying device (bottom)
+ **/
+void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
+{
+ blk_stack_limits(&t->limits, &b->limits, 0);
+}
+EXPORT_SYMBOL(blk_queue_stack_limits);
+
+/**
+ * blk_stack_limits - adjust queue_limits for stacked devices
+ * @t: the stacking driver limits (top device)
+ * @b: the underlying queue limits (bottom, component device)
+ * @start: first data sector within component device
+ *
+ * Description:
+ * This function is used by stacking drivers like MD and DM to ensure
+ * that all component devices have compatible block sizes and
+ * alignments. The stacking driver must provide a queue_limits
+ * struct (top) and then iteratively call the stacking function for
+ * all component (bottom) devices. The stacking function will
+ * attempt to combine the values and ensure proper alignment.
+ *
+ * Returns 0 if the top and bottom queue_limits are compatible. The
+ * top device's block sizes and alignment offsets may be adjusted to
+ * ensure alignment with the bottom device. If no compatible sizes
+ * and alignments exist, -1 is returned and the resulting top
+ * queue_limits will have the misaligned flag set to indicate that
+ * the alignment_offset is undefined.
+ */
+int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
+ sector_t start)
+{
+ unsigned int top, bottom, alignment, ret = 0;
+
+ t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
+ t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
+ t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
+ t->max_write_same_sectors = min(t->max_write_same_sectors,
+ b->max_write_same_sectors);
+ t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,
+ b->max_write_zeroes_sectors);
+ t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn);
+
+ t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask,
+ b->seg_boundary_mask);
+ t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask,
+ b->virt_boundary_mask);
+
+ t->max_segments = min_not_zero(t->max_segments, b->max_segments);
+ t->max_discard_segments = min_not_zero(t->max_discard_segments,
+ b->max_discard_segments);
+ t->max_integrity_segments = min_not_zero(t->max_integrity_segments,
+ b->max_integrity_segments);
+
+ t->max_segment_size = min_not_zero(t->max_segment_size,
+ b->max_segment_size);
+
+ t->misaligned |= b->misaligned;
+
+ alignment = queue_limit_alignment_offset(b, start);
+
+ /* Bottom device has different alignment. Check that it is
+ * compatible with the current top alignment.
+ */
+ if (t->alignment_offset != alignment) {
+
+ top = max(t->physical_block_size, t->io_min)
+ + t->alignment_offset;
+ bottom = max(b->physical_block_size, b->io_min) + alignment;
+
+ /* Verify that top and bottom intervals line up */
+ if (max(top, bottom) % min(top, bottom)) {
+ t->misaligned = 1;
+ ret = -1;
+ }
+ }
+
+ t->logical_block_size = max(t->logical_block_size,
+ b->logical_block_size);
+
+ t->physical_block_size = max(t->physical_block_size,
+ b->physical_block_size);
+
+ t->io_min = max(t->io_min, b->io_min);
+ t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
+
+ t->cluster &= b->cluster;
+
+ /* Physical block size a multiple of the logical block size? */
+ if (t->physical_block_size & (t->logical_block_size - 1)) {
+ t->physical_block_size = t->logical_block_size;
+ t->misaligned = 1;
+ ret = -1;
+ }
+
+ /* Minimum I/O a multiple of the physical block size? */
+ if (t->io_min & (t->physical_block_size - 1)) {
+ t->io_min = t->physical_block_size;
+ t->misaligned = 1;
+ ret = -1;
+ }
+
+ /* Optimal I/O a multiple of the physical block size? */
+ if (t->io_opt & (t->physical_block_size - 1)) {
+ t->io_opt = 0;
+ t->misaligned = 1;
+ ret = -1;
+ }
+
+ t->raid_partial_stripes_expensive =
+ max(t->raid_partial_stripes_expensive,
+ b->raid_partial_stripes_expensive);
+
+ /* Find lowest common alignment_offset */
+ t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
+ % max(t->physical_block_size, t->io_min);
+
+ /* Verify that new alignment_offset is on a logical block boundary */
+ if (t->alignment_offset & (t->logical_block_size - 1)) {
+ t->misaligned = 1;
+ ret = -1;
+ }
+
+ /* Discard alignment and granularity */
+ if (b->discard_granularity) {
+ alignment = queue_limit_discard_alignment(b, start);
+
+ if (t->discard_granularity != 0 &&
+ t->discard_alignment != alignment) {
+ top = t->discard_granularity + t->discard_alignment;
+ bottom = b->discard_granularity + alignment;
+
+ /* Verify that top and bottom intervals line up */
+ if ((max(top, bottom) % min(top, bottom)) != 0)
+ t->discard_misaligned = 1;
+ }
+
+ t->max_discard_sectors = min_not_zero(t->max_discard_sectors,
+ b->max_discard_sectors);
+ t->max_hw_discard_sectors = min_not_zero(t->max_hw_discard_sectors,
+ b->max_hw_discard_sectors);
+ t->discard_granularity = max(t->discard_granularity,
+ b->discard_granularity);
+ t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
+ t->discard_granularity;
+ }
+
+ if (b->chunk_sectors)
+ t->chunk_sectors = min_not_zero(t->chunk_sectors,
+ b->chunk_sectors);
+
+ return ret;
+}
+EXPORT_SYMBOL(blk_stack_limits);
+
+/**
+ * bdev_stack_limits - adjust queue limits for stacked drivers
+ * @t: the stacking driver limits (top device)
+ * @bdev: the component block_device (bottom)
+ * @start: first data sector within component device
+ *
+ * Description:
+ * Merges queue limits for a top device and a block_device. Returns
+ * 0 if alignment didn't change. Returns -1 if adding the bottom
+ * device caused misalignment.
+ */
+int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
+ sector_t start)
+{
+ struct request_queue *bq = bdev_get_queue(bdev);
+
+ start += get_start_sect(bdev);
+
+ return blk_stack_limits(t, &bq->limits, start);
+}
+EXPORT_SYMBOL(bdev_stack_limits);
+
+/**
+ * disk_stack_limits - adjust queue limits for stacked drivers
+ * @disk: MD/DM gendisk (top)
+ * @bdev: the underlying block device (bottom)
+ * @offset: offset to beginning of data within component device
+ *
+ * Description:
+ * Merges the limits for a top level gendisk and a bottom level
+ * block_device.
+ */
+void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
+ sector_t offset)
+{
+ struct request_queue *t = disk->queue;
+
+ if (bdev_stack_limits(&t->limits, bdev, offset >> 9) < 0) {
+ char top[BDEVNAME_SIZE], bottom[BDEVNAME_SIZE];
+
+ disk_name(disk, 0, top);
+ bdevname(bdev, bottom);
+
+ printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",
+ top, bottom);
+ }
+
+ t->backing_dev_info->io_pages =
+ t->limits.max_sectors >> (PAGE_SHIFT - 9);
+}
+EXPORT_SYMBOL(disk_stack_limits);
+
+/**
+ * blk_queue_dma_pad - set pad mask
+ * @q: the request queue for the device
+ * @mask: pad mask
+ *
+ * Set dma pad mask.
+ *
+ * Appending pad buffer to a request modifies the last entry of a
+ * scatter list such that it includes the pad buffer.
+ **/
+void blk_queue_dma_pad(struct request_queue *q, unsigned int mask)
+{
+ q->dma_pad_mask = mask;
+}
+EXPORT_SYMBOL(blk_queue_dma_pad);
+
+/**
+ * blk_queue_update_dma_pad - update pad mask
+ * @q: the request queue for the device
+ * @mask: pad mask
+ *
+ * Update dma pad mask.
+ *
+ * Appending pad buffer to a request modifies the last entry of a
+ * scatter list such that it includes the pad buffer.
+ **/
+void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
+{
+ if (mask > q->dma_pad_mask)
+ q->dma_pad_mask = mask;
+}
+EXPORT_SYMBOL(blk_queue_update_dma_pad);
+
+/**
+ * blk_queue_dma_drain - Set up a drain buffer for excess dma.
+ * @q: the request queue for the device
+ * @dma_drain_needed: fn which returns non-zero if drain is necessary
+ * @buf: physically contiguous buffer
+ * @size: size of the buffer in bytes
+ *
+ * Some devices have excess DMA problems and can't simply discard (or
+ * zero fill) the unwanted piece of the transfer. They have to have a
+ * real area of memory to transfer it into. The use case for this is
+ * ATAPI devices in DMA mode. If the packet command causes a transfer
+ * bigger than the transfer size some HBAs will lock up if there
+ * aren't DMA elements to contain the excess transfer. What this API
+ * does is adjust the queue so that the buf is always appended
+ * silently to the scatterlist.
+ *
+ * Note: This routine adjusts max_hw_segments to make room for appending
+ * the drain buffer. If you call blk_queue_max_segments() after calling
+ * this routine, you must set the limit to one fewer than your device
+ * can support otherwise there won't be room for the drain buffer.
+ */
+int blk_queue_dma_drain(struct request_queue *q,
+ dma_drain_needed_fn *dma_drain_needed,
+ void *buf, unsigned int size)
+{
+ if (queue_max_segments(q) < 2)
+ return -EINVAL;
+ /* make room for appending the drain */
+ blk_queue_max_segments(q, queue_max_segments(q) - 1);
+ q->dma_drain_needed = dma_drain_needed;
+ q->dma_drain_buffer = buf;
+ q->dma_drain_size = size;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blk_queue_dma_drain);
+
+/**
+ * blk_queue_segment_boundary - set boundary rules for segment merging
+ * @q: the request queue for the device
+ * @mask: the memory boundary mask
+ **/
+void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
+{
+ if (mask < PAGE_SIZE - 1) {
+ mask = PAGE_SIZE - 1;
+ printk(KERN_INFO "%s: set to minimum %lx\n",
+ __func__, mask);
+ }
+
+ q->limits.seg_boundary_mask = mask;
+}
+EXPORT_SYMBOL(blk_queue_segment_boundary);
+
+/**
+ * blk_queue_virt_boundary - set boundary rules for bio merging
+ * @q: the request queue for the device
+ * @mask: the memory boundary mask
+ **/
+void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask)
+{
+ q->limits.virt_boundary_mask = mask;
+}
+EXPORT_SYMBOL(blk_queue_virt_boundary);
+
+/**
+ * blk_queue_dma_alignment - set dma length and memory alignment
+ * @q: the request queue for the device
+ * @mask: alignment mask
+ *
+ * description:
+ * set required memory and length alignment for direct dma transactions.
+ * this is used when building direct io requests for the queue.
+ *
+ **/
+void blk_queue_dma_alignment(struct request_queue *q, int mask)
+{
+ q->dma_alignment = mask;
+}
+EXPORT_SYMBOL(blk_queue_dma_alignment);
+
+/**
+ * blk_queue_update_dma_alignment - update dma length and memory alignment
+ * @q: the request queue for the device
+ * @mask: alignment mask
+ *
+ * description:
+ * update required memory and length alignment for direct dma transactions.
+ * If the requested alignment is larger than the current alignment, then
+ * the current queue alignment is updated to the new value, otherwise it
+ * is left alone. The design of this is to allow multiple objects
+ * (driver, device, transport etc) to set their respective
+ * alignments without having them interfere.
+ *
+ **/
+void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
+{
+ BUG_ON(mask > PAGE_SIZE);
+
+ if (mask > q->dma_alignment)
+ q->dma_alignment = mask;
+}
+EXPORT_SYMBOL(blk_queue_update_dma_alignment);
+
+void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
+{
+ spin_lock_irq(q->queue_lock);
+ if (queueable)
+ clear_bit(QUEUE_FLAG_FLUSH_NQ, &q->queue_flags);
+ else
+ set_bit(QUEUE_FLAG_FLUSH_NQ, &q->queue_flags);
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);
+
+/**
+ * blk_set_queue_depth - tell the block layer about the device queue depth
+ * @q: the request queue for the device
+ * @depth: queue depth
+ *
+ */
+void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
+{
+ q->queue_depth = depth;
+ wbt_set_queue_depth(q->rq_wb, depth);
+}
+EXPORT_SYMBOL(blk_set_queue_depth);
+
+/**
+ * blk_queue_write_cache - configure queue's write cache
+ * @q: the request queue for the device
+ * @wc: write back cache on or off
+ * @fua: device supports FUA writes, if true
+ *
+ * Tell the block layer about the write cache of @q.
+ */
+void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
+{
+ spin_lock_irq(q->queue_lock);
+ if (wc)
+ queue_flag_set(QUEUE_FLAG_WC, q);
+ else
+ queue_flag_clear(QUEUE_FLAG_WC, q);
+ if (fua)
+ queue_flag_set(QUEUE_FLAG_FUA, q);
+ else
+ queue_flag_clear(QUEUE_FLAG_FUA, q);
+ spin_unlock_irq(q->queue_lock);
+
+ wbt_set_write_cache(q->rq_wb, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
+}
+EXPORT_SYMBOL_GPL(blk_queue_write_cache);
+
+static int __init blk_settings_init(void)
+{
+ blk_max_low_pfn = max_low_pfn - 1;
+ blk_max_pfn = max_pfn - 1;
+ return 0;
+}
+subsys_initcall(blk_settings_init);
diff --git a/src/kernel/linux/v4.14/block/blk-softirq.c b/src/kernel/linux/v4.14/block/blk-softirq.c
new file mode 100644
index 0000000..01e2b35
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-softirq.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to softirq rq completions
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/interrupt.h>
+#include <linux/cpu.h>
+#include <linux/sched.h>
+#include <linux/sched/topology.h>
+
+#include "blk.h"
+
+static DEFINE_PER_CPU(struct list_head, blk_cpu_done);
+
+/*
+ * Softirq action handler - move entries to local list and loop over them
+ * while passing them to the queue registered handler.
+ */
+static __latent_entropy void blk_done_softirq(struct softirq_action *h)
+{
+ struct list_head *cpu_list, local_list;
+
+ local_irq_disable();
+ cpu_list = this_cpu_ptr(&blk_cpu_done);
+ list_replace_init(cpu_list, &local_list);
+ local_irq_enable();
+
+ while (!list_empty(&local_list)) {
+ struct request *rq;
+
+ rq = list_entry(local_list.next, struct request, ipi_list);
+ list_del_init(&rq->ipi_list);
+ rq->q->softirq_done_fn(rq);
+ }
+}
+
+#ifdef CONFIG_SMP
+static void trigger_softirq(void *data)
+{
+ struct request *rq = data;
+ unsigned long flags;
+ struct list_head *list;
+
+ local_irq_save(flags);
+ list = this_cpu_ptr(&blk_cpu_done);
+ list_add_tail(&rq->ipi_list, list);
+
+ if (list->next == &rq->ipi_list)
+ raise_softirq_irqoff(BLOCK_SOFTIRQ);
+
+ local_irq_restore(flags);
+}
+
+/*
+ * Setup and invoke a run of 'trigger_softirq' on the given cpu.
+ */
+static int raise_blk_irq(int cpu, struct request *rq)
+{
+ if (cpu_online(cpu)) {
+ call_single_data_t *data = &rq->csd;
+
+ data->func = trigger_softirq;
+ data->info = rq;
+ data->flags = 0;
+
+ smp_call_function_single_async(cpu, data);
+ return 0;
+ }
+
+ return 1;
+}
+#else /* CONFIG_SMP */
+static int raise_blk_irq(int cpu, struct request *rq)
+{
+ return 1;
+}
+#endif
+
+static int blk_softirq_cpu_dead(unsigned int cpu)
+{
+ /*
+ * If a CPU goes away, splice its entries to the current CPU
+ * and trigger a run of the softirq
+ */
+ local_irq_disable();
+ list_splice_init(&per_cpu(blk_cpu_done, cpu),
+ this_cpu_ptr(&blk_cpu_done));
+ raise_softirq_irqoff(BLOCK_SOFTIRQ);
+ local_irq_enable();
+
+ return 0;
+}
+
+void __blk_complete_request(struct request *req)
+{
+ int ccpu, cpu;
+ struct request_queue *q = req->q;
+ unsigned long flags;
+ bool shared = false;
+
+ BUG_ON(!q->softirq_done_fn);
+
+ local_irq_save(flags);
+ cpu = smp_processor_id();
+
+ /*
+ * Select completion CPU
+ */
+ if (req->cpu != -1) {
+ ccpu = req->cpu;
+ if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags))
+ shared = cpus_share_cache(cpu, ccpu);
+ } else
+ ccpu = cpu;
+
+ /*
+ * If current CPU and requested CPU share a cache, run the softirq on
+ * the current CPU. One might concern this is just like
+ * QUEUE_FLAG_SAME_FORCE, but actually not. blk_complete_request() is
+ * running in interrupt handler, and currently I/O controller doesn't
+ * support multiple interrupts, so current CPU is unique actually. This
+ * avoids IPI sending from current CPU to the first CPU of a group.
+ */
+ if (ccpu == cpu || shared) {
+ struct list_head *list;
+do_local:
+ list = this_cpu_ptr(&blk_cpu_done);
+ list_add_tail(&req->ipi_list, list);
+
+ /*
+ * if the list only contains our just added request,
+ * signal a raise of the softirq. If there are already
+ * entries there, someone already raised the irq but it
+ * hasn't run yet.
+ */
+ if (list->next == &req->ipi_list)
+ raise_softirq_irqoff(BLOCK_SOFTIRQ);
+ } else if (raise_blk_irq(ccpu, req))
+ goto do_local;
+
+ local_irq_restore(flags);
+}
+
+/**
+ * blk_complete_request - end I/O on a request
+ * @req: the request being processed
+ *
+ * Description:
+ * Ends all I/O on a request. It does not handle partial completions,
+ * unless the driver actually implements this in its completion callback
+ * through requeueing. The actual completion happens out-of-order,
+ * through a softirq handler. The user must have registered a completion
+ * callback through blk_queue_softirq_done().
+ **/
+void blk_complete_request(struct request *req)
+{
+ if (unlikely(blk_should_fake_timeout(req->q)))
+ return;
+ if (!blk_mark_rq_complete(req))
+ __blk_complete_request(req);
+}
+EXPORT_SYMBOL(blk_complete_request);
+
+static __init int blk_softirq_init(void)
+{
+ int i;
+
+ for_each_possible_cpu(i)
+ INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));
+
+ open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
+ cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD,
+ "block/softirq:dead", NULL,
+ blk_softirq_cpu_dead);
+ return 0;
+}
+subsys_initcall(blk_softirq_init);
diff --git a/src/kernel/linux/v4.14/block/blk-stat.c b/src/kernel/linux/v4.14/block/blk-stat.c
new file mode 100644
index 0000000..c52356d
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-stat.c
@@ -0,0 +1,252 @@
+/*
+ * Block stat tracking code
+ *
+ * Copyright (C) 2016 Jens Axboe
+ */
+#include <linux/kernel.h>
+#include <linux/rculist.h>
+#include <linux/blk-mq.h>
+
+#include "blk-stat.h"
+#include "blk-mq.h"
+#include "blk.h"
+
+#define BLK_RQ_STAT_BATCH 64
+
+struct blk_queue_stats {
+ struct list_head callbacks;
+ spinlock_t lock;
+ bool enable_accounting;
+};
+
+static void blk_stat_init(struct blk_rq_stat *stat)
+{
+ stat->min = -1ULL;
+ stat->max = stat->nr_samples = stat->mean = 0;
+ stat->batch = stat->nr_batch = 0;
+}
+
+static void blk_stat_flush_batch(struct blk_rq_stat *stat)
+{
+ const s32 nr_batch = READ_ONCE(stat->nr_batch);
+ const s32 nr_samples = READ_ONCE(stat->nr_samples);
+
+ if (!nr_batch)
+ return;
+ if (!nr_samples)
+ stat->mean = div64_s64(stat->batch, nr_batch);
+ else {
+ stat->mean = div64_s64((stat->mean * nr_samples) +
+ stat->batch,
+ nr_batch + nr_samples);
+ }
+
+ stat->nr_samples += nr_batch;
+ stat->nr_batch = stat->batch = 0;
+}
+
+static void blk_stat_sum(struct blk_rq_stat *dst, struct blk_rq_stat *src)
+{
+ blk_stat_flush_batch(src);
+
+ if (!src->nr_samples)
+ return;
+
+ dst->min = min(dst->min, src->min);
+ dst->max = max(dst->max, src->max);
+
+ if (!dst->nr_samples)
+ dst->mean = src->mean;
+ else {
+ dst->mean = div64_s64((src->mean * src->nr_samples) +
+ (dst->mean * dst->nr_samples),
+ dst->nr_samples + src->nr_samples);
+ }
+ dst->nr_samples += src->nr_samples;
+}
+
+static void __blk_stat_add(struct blk_rq_stat *stat, u64 value)
+{
+ stat->min = min(stat->min, value);
+ stat->max = max(stat->max, value);
+
+ if (stat->batch + value < stat->batch ||
+ stat->nr_batch + 1 == BLK_RQ_STAT_BATCH)
+ blk_stat_flush_batch(stat);
+
+ stat->batch += value;
+ stat->nr_batch++;
+}
+
+void blk_stat_add(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ struct blk_stat_callback *cb;
+ struct blk_rq_stat *stat;
+ int bucket;
+ s64 now, value;
+
+ now = __blk_stat_time(ktime_to_ns(ktime_get()));
+ if (now < blk_stat_time(&rq->issue_stat))
+ return;
+
+ value = now - blk_stat_time(&rq->issue_stat);
+
+ blk_throtl_stat_add(rq, value);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(cb, &q->stats->callbacks, list) {
+ if (!blk_stat_is_active(cb))
+ continue;
+
+ bucket = cb->bucket_fn(rq);
+ if (bucket < 0)
+ continue;
+
+ stat = &get_cpu_ptr(cb->cpu_stat)[bucket];
+ __blk_stat_add(stat, value);
+ put_cpu_ptr(cb->cpu_stat);
+ }
+ rcu_read_unlock();
+}
+
+static void blk_stat_timer_fn(unsigned long data)
+{
+ struct blk_stat_callback *cb = (void *)data;
+ unsigned int bucket;
+ int cpu;
+
+ for (bucket = 0; bucket < cb->buckets; bucket++)
+ blk_stat_init(&cb->stat[bucket]);
+
+ for_each_online_cpu(cpu) {
+ struct blk_rq_stat *cpu_stat;
+
+ cpu_stat = per_cpu_ptr(cb->cpu_stat, cpu);
+ for (bucket = 0; bucket < cb->buckets; bucket++) {
+ blk_stat_sum(&cb->stat[bucket], &cpu_stat[bucket]);
+ blk_stat_init(&cpu_stat[bucket]);
+ }
+ }
+
+ cb->timer_fn(cb);
+}
+
+struct blk_stat_callback *
+blk_stat_alloc_callback(void (*timer_fn)(struct blk_stat_callback *),
+ int (*bucket_fn)(const struct request *),
+ unsigned int buckets, void *data)
+{
+ struct blk_stat_callback *cb;
+
+ cb = kmalloc(sizeof(*cb), GFP_KERNEL);
+ if (!cb)
+ return NULL;
+
+ cb->stat = kmalloc_array(buckets, sizeof(struct blk_rq_stat),
+ GFP_KERNEL);
+ if (!cb->stat) {
+ kfree(cb);
+ return NULL;
+ }
+ cb->cpu_stat = __alloc_percpu(buckets * sizeof(struct blk_rq_stat),
+ __alignof__(struct blk_rq_stat));
+ if (!cb->cpu_stat) {
+ kfree(cb->stat);
+ kfree(cb);
+ return NULL;
+ }
+
+ cb->timer_fn = timer_fn;
+ cb->bucket_fn = bucket_fn;
+ cb->data = data;
+ cb->buckets = buckets;
+ setup_timer(&cb->timer, blk_stat_timer_fn, (unsigned long)cb);
+
+ return cb;
+}
+EXPORT_SYMBOL_GPL(blk_stat_alloc_callback);
+
+void blk_stat_add_callback(struct request_queue *q,
+ struct blk_stat_callback *cb)
+{
+ unsigned int bucket;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct blk_rq_stat *cpu_stat;
+
+ cpu_stat = per_cpu_ptr(cb->cpu_stat, cpu);
+ for (bucket = 0; bucket < cb->buckets; bucket++)
+ blk_stat_init(&cpu_stat[bucket]);
+ }
+
+ spin_lock(&q->stats->lock);
+ list_add_tail_rcu(&cb->list, &q->stats->callbacks);
+ set_bit(QUEUE_FLAG_STATS, &q->queue_flags);
+ spin_unlock(&q->stats->lock);
+}
+EXPORT_SYMBOL_GPL(blk_stat_add_callback);
+
+void blk_stat_remove_callback(struct request_queue *q,
+ struct blk_stat_callback *cb)
+{
+ spin_lock(&q->stats->lock);
+ list_del_rcu(&cb->list);
+ if (list_empty(&q->stats->callbacks) && !q->stats->enable_accounting)
+ clear_bit(QUEUE_FLAG_STATS, &q->queue_flags);
+ spin_unlock(&q->stats->lock);
+
+ del_timer_sync(&cb->timer);
+}
+EXPORT_SYMBOL_GPL(blk_stat_remove_callback);
+
+static void blk_stat_free_callback_rcu(struct rcu_head *head)
+{
+ struct blk_stat_callback *cb;
+
+ cb = container_of(head, struct blk_stat_callback, rcu);
+ free_percpu(cb->cpu_stat);
+ kfree(cb->stat);
+ kfree(cb);
+}
+
+void blk_stat_free_callback(struct blk_stat_callback *cb)
+{
+ if (cb)
+ call_rcu(&cb->rcu, blk_stat_free_callback_rcu);
+}
+EXPORT_SYMBOL_GPL(blk_stat_free_callback);
+
+void blk_stat_enable_accounting(struct request_queue *q)
+{
+ spin_lock(&q->stats->lock);
+ q->stats->enable_accounting = true;
+ set_bit(QUEUE_FLAG_STATS, &q->queue_flags);
+ spin_unlock(&q->stats->lock);
+}
+
+struct blk_queue_stats *blk_alloc_queue_stats(void)
+{
+ struct blk_queue_stats *stats;
+
+ stats = kmalloc(sizeof(*stats), GFP_KERNEL);
+ if (!stats)
+ return NULL;
+
+ INIT_LIST_HEAD(&stats->callbacks);
+ spin_lock_init(&stats->lock);
+ stats->enable_accounting = false;
+
+ return stats;
+}
+
+void blk_free_queue_stats(struct blk_queue_stats *stats)
+{
+ if (!stats)
+ return;
+
+ WARN_ON(!list_empty(&stats->callbacks));
+
+ kfree(stats);
+}
diff --git a/src/kernel/linux/v4.14/block/blk-stat.h b/src/kernel/linux/v4.14/block/blk-stat.h
new file mode 100644
index 0000000..2dd3634
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-stat.h
@@ -0,0 +1,205 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BLK_STAT_H
+#define BLK_STAT_H
+
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/ktime.h>
+#include <linux/rcupdate.h>
+#include <linux/timer.h>
+
+/*
+ * from upper:
+ * 3 bits: reserved for other usage
+ * 12 bits: size
+ * 49 bits: time
+ */
+#define BLK_STAT_RES_BITS 3
+#define BLK_STAT_SIZE_BITS 12
+#define BLK_STAT_RES_SHIFT (64 - BLK_STAT_RES_BITS)
+#define BLK_STAT_SIZE_SHIFT (BLK_STAT_RES_SHIFT - BLK_STAT_SIZE_BITS)
+#define BLK_STAT_TIME_MASK ((1ULL << BLK_STAT_SIZE_SHIFT) - 1)
+#define BLK_STAT_SIZE_MASK \
+ (((1ULL << BLK_STAT_SIZE_BITS) - 1) << BLK_STAT_SIZE_SHIFT)
+#define BLK_STAT_RES_MASK (~((1ULL << BLK_STAT_RES_SHIFT) - 1))
+
+/**
+ * struct blk_stat_callback - Block statistics callback.
+ *
+ * A &struct blk_stat_callback is associated with a &struct request_queue. While
+ * @timer is active, that queue's request completion latencies are sorted into
+ * buckets by @bucket_fn and added to a per-cpu buffer, @cpu_stat. When the
+ * timer fires, @cpu_stat is flushed to @stat and @timer_fn is invoked.
+ */
+struct blk_stat_callback {
+ /*
+ * @list: RCU list of callbacks for a &struct request_queue.
+ */
+ struct list_head list;
+
+ /**
+ * @timer: Timer for the next callback invocation.
+ */
+ struct timer_list timer;
+
+ /**
+ * @cpu_stat: Per-cpu statistics buckets.
+ */
+ struct blk_rq_stat __percpu *cpu_stat;
+
+ /**
+ * @bucket_fn: Given a request, returns which statistics bucket it
+ * should be accounted under. Return -1 for no bucket for this
+ * request.
+ */
+ int (*bucket_fn)(const struct request *);
+
+ /**
+ * @buckets: Number of statistics buckets.
+ */
+ unsigned int buckets;
+
+ /**
+ * @stat: Array of statistics buckets.
+ */
+ struct blk_rq_stat *stat;
+
+ /**
+ * @fn: Callback function.
+ */
+ void (*timer_fn)(struct blk_stat_callback *);
+
+ /**
+ * @data: Private pointer for the user.
+ */
+ void *data;
+
+ struct rcu_head rcu;
+};
+
+struct blk_queue_stats *blk_alloc_queue_stats(void);
+void blk_free_queue_stats(struct blk_queue_stats *);
+
+void blk_stat_add(struct request *);
+
+static inline u64 __blk_stat_time(u64 time)
+{
+ return time & BLK_STAT_TIME_MASK;
+}
+
+static inline u64 blk_stat_time(struct blk_issue_stat *stat)
+{
+ return __blk_stat_time(stat->stat);
+}
+
+static inline sector_t blk_capped_size(sector_t size)
+{
+ return size & ((1ULL << BLK_STAT_SIZE_BITS) - 1);
+}
+
+static inline sector_t blk_stat_size(struct blk_issue_stat *stat)
+{
+ return (stat->stat & BLK_STAT_SIZE_MASK) >> BLK_STAT_SIZE_SHIFT;
+}
+
+static inline void blk_stat_set_issue(struct blk_issue_stat *stat,
+ sector_t size)
+{
+ stat->stat = (stat->stat & BLK_STAT_RES_MASK) |
+ (ktime_to_ns(ktime_get()) & BLK_STAT_TIME_MASK) |
+ (((u64)blk_capped_size(size)) << BLK_STAT_SIZE_SHIFT);
+}
+
+/* record time/size info in request but not add a callback */
+void blk_stat_enable_accounting(struct request_queue *q);
+
+/**
+ * blk_stat_alloc_callback() - Allocate a block statistics callback.
+ * @timer_fn: Timer callback function.
+ * @bucket_fn: Bucket callback function.
+ * @buckets: Number of statistics buckets.
+ * @data: Value for the @data field of the &struct blk_stat_callback.
+ *
+ * See &struct blk_stat_callback for details on the callback functions.
+ *
+ * Return: &struct blk_stat_callback on success or NULL on ENOMEM.
+ */
+struct blk_stat_callback *
+blk_stat_alloc_callback(void (*timer_fn)(struct blk_stat_callback *),
+ int (*bucket_fn)(const struct request *),
+ unsigned int buckets, void *data);
+
+/**
+ * blk_stat_add_callback() - Add a block statistics callback to be run on a
+ * request queue.
+ * @q: The request queue.
+ * @cb: The callback.
+ *
+ * Note that a single &struct blk_stat_callback can only be added to a single
+ * &struct request_queue.
+ */
+void blk_stat_add_callback(struct request_queue *q,
+ struct blk_stat_callback *cb);
+
+/**
+ * blk_stat_remove_callback() - Remove a block statistics callback from a
+ * request queue.
+ * @q: The request queue.
+ * @cb: The callback.
+ *
+ * When this returns, the callback is not running on any CPUs and will not be
+ * called again unless readded.
+ */
+void blk_stat_remove_callback(struct request_queue *q,
+ struct blk_stat_callback *cb);
+
+/**
+ * blk_stat_free_callback() - Free a block statistics callback.
+ * @cb: The callback.
+ *
+ * @cb may be NULL, in which case this does nothing. If it is not NULL, @cb must
+ * not be associated with a request queue. I.e., if it was previously added with
+ * blk_stat_add_callback(), it must also have been removed since then with
+ * blk_stat_remove_callback().
+ */
+void blk_stat_free_callback(struct blk_stat_callback *cb);
+
+/**
+ * blk_stat_is_active() - Check if a block statistics callback is currently
+ * gathering statistics.
+ * @cb: The callback.
+ */
+static inline bool blk_stat_is_active(struct blk_stat_callback *cb)
+{
+ return timer_pending(&cb->timer);
+}
+
+/**
+ * blk_stat_activate_nsecs() - Gather block statistics during a time window in
+ * nanoseconds.
+ * @cb: The callback.
+ * @nsecs: Number of nanoseconds to gather statistics for.
+ *
+ * The timer callback will be called when the window expires.
+ */
+static inline void blk_stat_activate_nsecs(struct blk_stat_callback *cb,
+ u64 nsecs)
+{
+ mod_timer(&cb->timer, jiffies + nsecs_to_jiffies(nsecs));
+}
+
+/**
+ * blk_stat_activate_msecs() - Gather block statistics during a time window in
+ * milliseconds.
+ * @cb: The callback.
+ * @msecs: Number of milliseconds to gather statistics for.
+ *
+ * The timer callback will be called when the window expires.
+ */
+static inline void blk_stat_activate_msecs(struct blk_stat_callback *cb,
+ unsigned int msecs)
+{
+ mod_timer(&cb->timer, jiffies + msecs_to_jiffies(msecs));
+}
+
+#endif
diff --git a/src/kernel/linux/v4.14/block/blk-sysfs.c b/src/kernel/linux/v4.14/block/blk-sysfs.c
new file mode 100644
index 0000000..9caf96c
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-sysfs.c
@@ -0,0 +1,955 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to sysfs handling
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/blktrace_api.h>
+#include <linux/blk-mq.h>
+#include <linux/blk-cgroup.h>
+
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-debugfs.h"
+#include "blk-wbt.h"
+
+struct queue_sysfs_entry {
+ struct attribute attr;
+ ssize_t (*show)(struct request_queue *, char *);
+ ssize_t (*store)(struct request_queue *, const char *, size_t);
+};
+
+static ssize_t
+queue_var_show(unsigned long var, char *page)
+{
+ return sprintf(page, "%lu\n", var);
+}
+
+static ssize_t
+queue_var_store(unsigned long *var, const char *page, size_t count)
+{
+ int err;
+ unsigned long v;
+
+ err = kstrtoul(page, 10, &v);
+ if (err || v > UINT_MAX)
+ return -EINVAL;
+
+ *var = v;
+
+ return count;
+}
+
+static ssize_t queue_var_store64(s64 *var, const char *page)
+{
+ int err;
+ s64 v;
+
+ err = kstrtos64(page, 10, &v);
+ if (err < 0)
+ return err;
+
+ *var = v;
+ return 0;
+}
+
+static ssize_t queue_requests_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(q->nr_requests, (page));
+}
+
+static ssize_t
+queue_requests_store(struct request_queue *q, const char *page, size_t count)
+{
+ unsigned long nr;
+ int ret, err;
+
+ if (!q->request_fn && !q->mq_ops)
+ return -EINVAL;
+
+ ret = queue_var_store(&nr, page, count);
+ if (ret < 0)
+ return ret;
+
+ if (nr < BLKDEV_MIN_RQ)
+ nr = BLKDEV_MIN_RQ;
+
+ if (q->request_fn)
+ err = blk_update_nr_requests(q, nr);
+ else
+ err = blk_mq_update_nr_requests(q, nr);
+
+ if (err)
+ return err;
+
+ return ret;
+}
+
+static ssize_t queue_ra_show(struct request_queue *q, char *page)
+{
+ unsigned long ra_kb = q->backing_dev_info->ra_pages <<
+ (PAGE_SHIFT - 10);
+
+ return queue_var_show(ra_kb, (page));
+}
+
+static ssize_t
+queue_ra_store(struct request_queue *q, const char *page, size_t count)
+{
+ unsigned long ra_kb;
+ ssize_t ret = queue_var_store(&ra_kb, page, count);
+
+ if (ret < 0)
+ return ret;
+
+ q->backing_dev_info->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
+
+ return ret;
+}
+
+static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
+{
+ int max_sectors_kb = queue_max_sectors(q) >> 1;
+
+ return queue_var_show(max_sectors_kb, (page));
+}
+
+static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(queue_max_segments(q), (page));
+}
+
+static ssize_t queue_max_discard_segments_show(struct request_queue *q,
+ char *page)
+{
+ return queue_var_show(queue_max_discard_segments(q), (page));
+}
+
+static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(q->limits.max_integrity_segments, (page));
+}
+
+static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
+{
+ if (blk_queue_cluster(q))
+ return queue_var_show(queue_max_segment_size(q), (page));
+
+ return queue_var_show(PAGE_SIZE, (page));
+}
+
+static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(queue_logical_block_size(q), page);
+}
+
+static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(queue_physical_block_size(q), page);
+}
+
+static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(q->limits.chunk_sectors, page);
+}
+
+static ssize_t queue_io_min_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(queue_io_min(q), page);
+}
+
+static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(queue_io_opt(q), page);
+}
+
+static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(q->limits.discard_granularity, page);
+}
+
+static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
+{
+
+ return sprintf(page, "%llu\n",
+ (unsigned long long)q->limits.max_hw_discard_sectors << 9);
+}
+
+static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
+{
+ return sprintf(page, "%llu\n",
+ (unsigned long long)q->limits.max_discard_sectors << 9);
+}
+
+static ssize_t queue_discard_max_store(struct request_queue *q,
+ const char *page, size_t count)
+{
+ unsigned long max_discard;
+ ssize_t ret = queue_var_store(&max_discard, page, count);
+
+ if (ret < 0)
+ return ret;
+
+ if (max_discard & (q->limits.discard_granularity - 1))
+ return -EINVAL;
+
+ max_discard >>= 9;
+ if (max_discard > UINT_MAX)
+ return -EINVAL;
+
+ if (max_discard > q->limits.max_hw_discard_sectors)
+ max_discard = q->limits.max_hw_discard_sectors;
+
+ q->limits.max_discard_sectors = max_discard;
+ return ret;
+}
+
+static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(0, page);
+}
+
+static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
+{
+ return sprintf(page, "%llu\n",
+ (unsigned long long)q->limits.max_write_same_sectors << 9);
+}
+
+static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
+{
+ return sprintf(page, "%llu\n",
+ (unsigned long long)q->limits.max_write_zeroes_sectors << 9);
+}
+
+static ssize_t
+queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
+{
+ unsigned long max_sectors_kb,
+ max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
+ page_kb = 1 << (PAGE_SHIFT - 10);
+ ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
+
+ if (ret < 0)
+ return ret;
+
+ max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long)
+ q->limits.max_dev_sectors >> 1);
+
+ if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
+ return -EINVAL;
+
+ spin_lock_irq(q->queue_lock);
+ q->limits.max_sectors = max_sectors_kb << 1;
+ q->backing_dev_info->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
+ spin_unlock_irq(q->queue_lock);
+
+ return ret;
+}
+
+static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
+{
+ int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
+
+ return queue_var_show(max_hw_sectors_kb, (page));
+}
+
+#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
+static ssize_t \
+queue_show_##name(struct request_queue *q, char *page) \
+{ \
+ int bit; \
+ bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
+ return queue_var_show(neg ? !bit : bit, page); \
+} \
+static ssize_t \
+queue_store_##name(struct request_queue *q, const char *page, size_t count) \
+{ \
+ unsigned long val; \
+ ssize_t ret; \
+ ret = queue_var_store(&val, page, count); \
+ if (ret < 0) \
+ return ret; \
+ if (neg) \
+ val = !val; \
+ \
+ spin_lock_irq(q->queue_lock); \
+ if (val) \
+ queue_flag_set(QUEUE_FLAG_##flag, q); \
+ else \
+ queue_flag_clear(QUEUE_FLAG_##flag, q); \
+ spin_unlock_irq(q->queue_lock); \
+ return ret; \
+}
+
+QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
+QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
+QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
+#undef QUEUE_SYSFS_BIT_FNS
+
+static ssize_t queue_zoned_show(struct request_queue *q, char *page)
+{
+ switch (blk_queue_zoned_model(q)) {
+ case BLK_ZONED_HA:
+ return sprintf(page, "host-aware\n");
+ case BLK_ZONED_HM:
+ return sprintf(page, "host-managed\n");
+ default:
+ return sprintf(page, "none\n");
+ }
+}
+
+static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
+{
+ return queue_var_show((blk_queue_nomerges(q) << 1) |
+ blk_queue_noxmerges(q), page);
+}
+
+static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
+ size_t count)
+{
+ unsigned long nm;
+ ssize_t ret = queue_var_store(&nm, page, count);
+
+ if (ret < 0)
+ return ret;
+
+ spin_lock_irq(q->queue_lock);
+ queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
+ queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
+ if (nm == 2)
+ queue_flag_set(QUEUE_FLAG_NOMERGES, q);
+ else if (nm)
+ queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
+ spin_unlock_irq(q->queue_lock);
+
+ return ret;
+}
+
+static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
+{
+ bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
+ bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
+
+ return queue_var_show(set << force, page);
+}
+
+static ssize_t
+queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
+{
+ ssize_t ret = -EINVAL;
+#ifdef CONFIG_SMP
+ unsigned long val;
+
+ ret = queue_var_store(&val, page, count);
+ if (ret < 0)
+ return ret;
+
+ spin_lock_irq(q->queue_lock);
+ if (val == 2) {
+ queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
+ queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
+ } else if (val == 1) {
+ queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
+ queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
+ } else if (val == 0) {
+ queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
+ queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
+ }
+ spin_unlock_irq(q->queue_lock);
+#endif
+ return ret;
+}
+
+static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
+{
+ int val;
+
+ if (q->poll_nsec == -1)
+ val = -1;
+ else
+ val = q->poll_nsec / 1000;
+
+ return sprintf(page, "%d\n", val);
+}
+
+static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
+ size_t count)
+{
+ int err, val;
+
+ if (!q->mq_ops || !q->mq_ops->poll)
+ return -EINVAL;
+
+ err = kstrtoint(page, 10, &val);
+ if (err < 0)
+ return err;
+
+ if (val == -1)
+ q->poll_nsec = -1;
+ else
+ q->poll_nsec = val * 1000;
+
+ return count;
+}
+
+static ssize_t queue_poll_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
+}
+
+static ssize_t queue_poll_store(struct request_queue *q, const char *page,
+ size_t count)
+{
+ unsigned long poll_on;
+ ssize_t ret;
+
+ if (!q->mq_ops || !q->mq_ops->poll)
+ return -EINVAL;
+
+ ret = queue_var_store(&poll_on, page, count);
+ if (ret < 0)
+ return ret;
+
+ spin_lock_irq(q->queue_lock);
+ if (poll_on)
+ queue_flag_set(QUEUE_FLAG_POLL, q);
+ else
+ queue_flag_clear(QUEUE_FLAG_POLL, q);
+ spin_unlock_irq(q->queue_lock);
+
+ return ret;
+}
+
+static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
+{
+ if (!q->rq_wb)
+ return -EINVAL;
+
+ return sprintf(page, "%llu\n", div_u64(q->rq_wb->min_lat_nsec, 1000));
+}
+
+static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
+ size_t count)
+{
+ struct rq_wb *rwb;
+ ssize_t ret;
+ s64 val;
+
+ ret = queue_var_store64(&val, page);
+ if (ret < 0)
+ return ret;
+ if (val < -1)
+ return -EINVAL;
+
+ rwb = q->rq_wb;
+ if (!rwb) {
+ ret = wbt_init(q);
+ if (ret)
+ return ret;
+
+ rwb = q->rq_wb;
+ if (!rwb)
+ return -EINVAL;
+ }
+
+ if (val == -1)
+ rwb->min_lat_nsec = wbt_default_latency_nsec(q);
+ else if (val >= 0)
+ rwb->min_lat_nsec = val * 1000ULL;
+
+ if (rwb->enable_state == WBT_STATE_ON_DEFAULT)
+ rwb->enable_state = WBT_STATE_ON_MANUAL;
+
+ wbt_update_limits(rwb);
+ return count;
+}
+
+static ssize_t queue_wc_show(struct request_queue *q, char *page)
+{
+ if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
+ return sprintf(page, "write back\n");
+
+ return sprintf(page, "write through\n");
+}
+
+static ssize_t queue_wc_store(struct request_queue *q, const char *page,
+ size_t count)
+{
+ int set = -1;
+
+ if (!strncmp(page, "write back", 10))
+ set = 1;
+ else if (!strncmp(page, "write through", 13) ||
+ !strncmp(page, "none", 4))
+ set = 0;
+
+ if (set == -1)
+ return -EINVAL;
+
+ spin_lock_irq(q->queue_lock);
+ if (set)
+ queue_flag_set(QUEUE_FLAG_WC, q);
+ else
+ queue_flag_clear(QUEUE_FLAG_WC, q);
+ spin_unlock_irq(q->queue_lock);
+
+ return count;
+}
+
+static ssize_t queue_dax_show(struct request_queue *q, char *page)
+{
+ return queue_var_show(blk_queue_dax(q), page);
+}
+
+static struct queue_sysfs_entry queue_requests_entry = {
+ .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_requests_show,
+ .store = queue_requests_store,
+};
+
+static struct queue_sysfs_entry queue_ra_entry = {
+ .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_ra_show,
+ .store = queue_ra_store,
+};
+
+static struct queue_sysfs_entry queue_max_sectors_entry = {
+ .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_max_sectors_show,
+ .store = queue_max_sectors_store,
+};
+
+static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
+ .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
+ .show = queue_max_hw_sectors_show,
+};
+
+static struct queue_sysfs_entry queue_max_segments_entry = {
+ .attr = {.name = "max_segments", .mode = S_IRUGO },
+ .show = queue_max_segments_show,
+};
+
+static struct queue_sysfs_entry queue_max_discard_segments_entry = {
+ .attr = {.name = "max_discard_segments", .mode = S_IRUGO },
+ .show = queue_max_discard_segments_show,
+};
+
+static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
+ .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
+ .show = queue_max_integrity_segments_show,
+};
+
+static struct queue_sysfs_entry queue_max_segment_size_entry = {
+ .attr = {.name = "max_segment_size", .mode = S_IRUGO },
+ .show = queue_max_segment_size_show,
+};
+
+static struct queue_sysfs_entry queue_iosched_entry = {
+ .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
+ .show = elv_iosched_show,
+ .store = elv_iosched_store,
+};
+
+static struct queue_sysfs_entry queue_hw_sector_size_entry = {
+ .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
+ .show = queue_logical_block_size_show,
+};
+
+static struct queue_sysfs_entry queue_logical_block_size_entry = {
+ .attr = {.name = "logical_block_size", .mode = S_IRUGO },
+ .show = queue_logical_block_size_show,
+};
+
+static struct queue_sysfs_entry queue_physical_block_size_entry = {
+ .attr = {.name = "physical_block_size", .mode = S_IRUGO },
+ .show = queue_physical_block_size_show,
+};
+
+static struct queue_sysfs_entry queue_chunk_sectors_entry = {
+ .attr = {.name = "chunk_sectors", .mode = S_IRUGO },
+ .show = queue_chunk_sectors_show,
+};
+
+static struct queue_sysfs_entry queue_io_min_entry = {
+ .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
+ .show = queue_io_min_show,
+};
+
+static struct queue_sysfs_entry queue_io_opt_entry = {
+ .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
+ .show = queue_io_opt_show,
+};
+
+static struct queue_sysfs_entry queue_discard_granularity_entry = {
+ .attr = {.name = "discard_granularity", .mode = S_IRUGO },
+ .show = queue_discard_granularity_show,
+};
+
+static struct queue_sysfs_entry queue_discard_max_hw_entry = {
+ .attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO },
+ .show = queue_discard_max_hw_show,
+};
+
+static struct queue_sysfs_entry queue_discard_max_entry = {
+ .attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_discard_max_show,
+ .store = queue_discard_max_store,
+};
+
+static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
+ .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
+ .show = queue_discard_zeroes_data_show,
+};
+
+static struct queue_sysfs_entry queue_write_same_max_entry = {
+ .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
+ .show = queue_write_same_max_show,
+};
+
+static struct queue_sysfs_entry queue_write_zeroes_max_entry = {
+ .attr = {.name = "write_zeroes_max_bytes", .mode = S_IRUGO },
+ .show = queue_write_zeroes_max_show,
+};
+
+static struct queue_sysfs_entry queue_nonrot_entry = {
+ .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_show_nonrot,
+ .store = queue_store_nonrot,
+};
+
+static struct queue_sysfs_entry queue_zoned_entry = {
+ .attr = {.name = "zoned", .mode = S_IRUGO },
+ .show = queue_zoned_show,
+};
+
+static struct queue_sysfs_entry queue_nomerges_entry = {
+ .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_nomerges_show,
+ .store = queue_nomerges_store,
+};
+
+static struct queue_sysfs_entry queue_rq_affinity_entry = {
+ .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_rq_affinity_show,
+ .store = queue_rq_affinity_store,
+};
+
+static struct queue_sysfs_entry queue_iostats_entry = {
+ .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_show_iostats,
+ .store = queue_store_iostats,
+};
+
+static struct queue_sysfs_entry queue_random_entry = {
+ .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_show_random,
+ .store = queue_store_random,
+};
+
+static struct queue_sysfs_entry queue_poll_entry = {
+ .attr = {.name = "io_poll", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_poll_show,
+ .store = queue_poll_store,
+};
+
+static struct queue_sysfs_entry queue_poll_delay_entry = {
+ .attr = {.name = "io_poll_delay", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_poll_delay_show,
+ .store = queue_poll_delay_store,
+};
+
+static struct queue_sysfs_entry queue_wc_entry = {
+ .attr = {.name = "write_cache", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_wc_show,
+ .store = queue_wc_store,
+};
+
+static struct queue_sysfs_entry queue_dax_entry = {
+ .attr = {.name = "dax", .mode = S_IRUGO },
+ .show = queue_dax_show,
+};
+
+static struct queue_sysfs_entry queue_wb_lat_entry = {
+ .attr = {.name = "wbt_lat_usec", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_wb_lat_show,
+ .store = queue_wb_lat_store,
+};
+
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+static struct queue_sysfs_entry throtl_sample_time_entry = {
+ .attr = {.name = "throttle_sample_time", .mode = S_IRUGO | S_IWUSR },
+ .show = blk_throtl_sample_time_show,
+ .store = blk_throtl_sample_time_store,
+};
+#endif
+
+static struct attribute *default_attrs[] = {
+ &queue_requests_entry.attr,
+ &queue_ra_entry.attr,
+ &queue_max_hw_sectors_entry.attr,
+ &queue_max_sectors_entry.attr,
+ &queue_max_segments_entry.attr,
+ &queue_max_discard_segments_entry.attr,
+ &queue_max_integrity_segments_entry.attr,
+ &queue_max_segment_size_entry.attr,
+ &queue_iosched_entry.attr,
+ &queue_hw_sector_size_entry.attr,
+ &queue_logical_block_size_entry.attr,
+ &queue_physical_block_size_entry.attr,
+ &queue_chunk_sectors_entry.attr,
+ &queue_io_min_entry.attr,
+ &queue_io_opt_entry.attr,
+ &queue_discard_granularity_entry.attr,
+ &queue_discard_max_entry.attr,
+ &queue_discard_max_hw_entry.attr,
+ &queue_discard_zeroes_data_entry.attr,
+ &queue_write_same_max_entry.attr,
+ &queue_write_zeroes_max_entry.attr,
+ &queue_nonrot_entry.attr,
+ &queue_zoned_entry.attr,
+ &queue_nomerges_entry.attr,
+ &queue_rq_affinity_entry.attr,
+ &queue_iostats_entry.attr,
+ &queue_random_entry.attr,
+ &queue_poll_entry.attr,
+ &queue_wc_entry.attr,
+ &queue_dax_entry.attr,
+ &queue_wb_lat_entry.attr,
+ &queue_poll_delay_entry.attr,
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+ &throtl_sample_time_entry.attr,
+#endif
+ NULL,
+};
+
+#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
+
+static ssize_t
+queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
+{
+ struct queue_sysfs_entry *entry = to_queue(attr);
+ struct request_queue *q =
+ container_of(kobj, struct request_queue, kobj);
+ ssize_t res;
+
+ if (!entry->show)
+ return -EIO;
+ mutex_lock(&q->sysfs_lock);
+ if (blk_queue_dying(q)) {
+ mutex_unlock(&q->sysfs_lock);
+ return -ENOENT;
+ }
+ res = entry->show(q, page);
+ mutex_unlock(&q->sysfs_lock);
+ return res;
+}
+
+static ssize_t
+queue_attr_store(struct kobject *kobj, struct attribute *attr,
+ const char *page, size_t length)
+{
+ struct queue_sysfs_entry *entry = to_queue(attr);
+ struct request_queue *q;
+ ssize_t res;
+
+ if (!entry->store)
+ return -EIO;
+
+ q = container_of(kobj, struct request_queue, kobj);
+ mutex_lock(&q->sysfs_lock);
+ if (blk_queue_dying(q)) {
+ mutex_unlock(&q->sysfs_lock);
+ return -ENOENT;
+ }
+ res = entry->store(q, page, length);
+ mutex_unlock(&q->sysfs_lock);
+ return res;
+}
+
+static void blk_free_queue_rcu(struct rcu_head *rcu_head)
+{
+ struct request_queue *q = container_of(rcu_head, struct request_queue,
+ rcu_head);
+ kmem_cache_free(blk_requestq_cachep, q);
+}
+
+/**
+ * __blk_release_queue - release a request queue when it is no longer needed
+ * @work: pointer to the release_work member of the request queue to be released
+ *
+ * Description:
+ * blk_release_queue is the counterpart of blk_init_queue(). It should be
+ * called when a request queue is being released; typically when a block
+ * device is being de-registered. Its primary task it to free the queue
+ * itself.
+ *
+ * Notes:
+ * The low level driver must have finished any outstanding requests first
+ * via blk_cleanup_queue().
+ *
+ * Although blk_release_queue() may be called with preemption disabled,
+ * __blk_release_queue() may sleep.
+ */
+static void __blk_release_queue(struct work_struct *work)
+{
+ struct request_queue *q = container_of(work, typeof(*q), release_work);
+
+ if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
+ blk_stat_remove_callback(q, q->poll_cb);
+ blk_stat_free_callback(q->poll_cb);
+ bdi_put(q->backing_dev_info);
+ blkcg_exit_queue(q);
+
+ if (q->elevator) {
+ ioc_clear_queue(q);
+ elevator_exit(q, q->elevator);
+ }
+
+ blk_free_queue_stats(q->stats);
+
+ if (q->mq_ops)
+ cancel_delayed_work_sync(&q->requeue_work);
+
+ blk_exit_rl(q, &q->root_rl);
+
+ if (q->queue_tags)
+ __blk_queue_free_tags(q);
+
+ if (!q->mq_ops) {
+ if (q->exit_rq_fn)
+ q->exit_rq_fn(q, q->fq->flush_rq);
+ blk_free_flush_queue(q->fq);
+ } else {
+ blk_mq_release(q);
+ }
+
+ blk_trace_shutdown(q);
+
+ if (q->mq_ops)
+ blk_mq_debugfs_unregister(q);
+
+ if (q->bio_split)
+ bioset_free(q->bio_split);
+
+ ida_simple_remove(&blk_queue_ida, q->id);
+ call_rcu(&q->rcu_head, blk_free_queue_rcu);
+}
+
+static void blk_release_queue(struct kobject *kobj)
+{
+ struct request_queue *q =
+ container_of(kobj, struct request_queue, kobj);
+
+ INIT_WORK(&q->release_work, __blk_release_queue);
+ schedule_work(&q->release_work);
+}
+
+static const struct sysfs_ops queue_sysfs_ops = {
+ .show = queue_attr_show,
+ .store = queue_attr_store,
+};
+
+struct kobj_type blk_queue_ktype = {
+ .sysfs_ops = &queue_sysfs_ops,
+ .default_attrs = default_attrs,
+ .release = blk_release_queue,
+};
+
+int blk_register_queue(struct gendisk *disk)
+{
+ int ret;
+ struct device *dev = disk_to_dev(disk);
+ struct request_queue *q = disk->queue;
+
+ if (WARN_ON(!q))
+ return -ENXIO;
+
+ WARN_ONCE(test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags),
+ "%s is registering an already registered queue\n",
+ kobject_name(&dev->kobj));
+ queue_flag_set_unlocked(QUEUE_FLAG_REGISTERED, q);
+
+ /*
+ * SCSI probing may synchronously create and destroy a lot of
+ * request_queues for non-existent devices. Shutting down a fully
+ * functional queue takes measureable wallclock time as RCU grace
+ * periods are involved. To avoid excessive latency in these
+ * cases, a request_queue starts out in a degraded mode which is
+ * faster to shut down and is made fully functional here as
+ * request_queues for non-existent devices never get registered.
+ */
+ if (!blk_queue_init_done(q)) {
+ queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
+ percpu_ref_switch_to_percpu(&q->q_usage_counter);
+ blk_queue_bypass_end(q);
+ }
+
+ ret = blk_trace_init_sysfs(dev);
+ if (ret)
+ return ret;
+
+ /* Prevent changes through sysfs until registration is completed. */
+ mutex_lock(&q->sysfs_lock);
+
+ ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
+ if (ret < 0) {
+ blk_trace_remove_sysfs(dev);
+ goto unlock;
+ }
+
+ if (q->mq_ops) {
+ __blk_mq_register_dev(dev, q);
+ blk_mq_debugfs_register(q);
+ }
+
+ kobject_uevent(&q->kobj, KOBJ_ADD);
+
+ wbt_enable_default(q);
+
+ blk_throtl_register_queue(q);
+
+ if (q->request_fn || (q->mq_ops && q->elevator)) {
+ ret = elv_register_queue(q);
+ if (ret) {
+ kobject_uevent(&q->kobj, KOBJ_REMOVE);
+ kobject_del(&q->kobj);
+ blk_trace_remove_sysfs(dev);
+ kobject_put(&dev->kobj);
+ goto unlock;
+ }
+ }
+ ret = 0;
+unlock:
+ mutex_unlock(&q->sysfs_lock);
+ return ret;
+}
+
+void blk_unregister_queue(struct gendisk *disk)
+{
+ struct request_queue *q = disk->queue;
+
+ if (WARN_ON(!q))
+ return;
+
+ mutex_lock(&q->sysfs_lock);
+ queue_flag_clear_unlocked(QUEUE_FLAG_REGISTERED, q);
+ mutex_unlock(&q->sysfs_lock);
+
+ wbt_exit(q);
+
+
+ if (q->mq_ops)
+ blk_mq_unregister_dev(disk_to_dev(disk), q);
+
+ if (q->request_fn || (q->mq_ops && q->elevator))
+ elv_unregister_queue(q);
+
+ kobject_uevent(&q->kobj, KOBJ_REMOVE);
+ kobject_del(&q->kobj);
+ blk_trace_remove_sysfs(disk_to_dev(disk));
+ kobject_put(&disk_to_dev(disk)->kobj);
+}
diff --git a/src/kernel/linux/v4.14/block/blk-tag.c b/src/kernel/linux/v4.14/block/blk-tag.c
new file mode 100644
index 0000000..09f19c6
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-tag.c
@@ -0,0 +1,400 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to tagged command queuing
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+
+#include "blk.h"
+
+/**
+ * blk_queue_find_tag - find a request by its tag and queue
+ * @q: The request queue for the device
+ * @tag: The tag of the request
+ *
+ * Notes:
+ * Should be used when a device returns a tag and you want to match
+ * it with a request.
+ *
+ * no locks need be held.
+ **/
+struct request *blk_queue_find_tag(struct request_queue *q, int tag)
+{
+ return blk_map_queue_find_tag(q->queue_tags, tag);
+}
+EXPORT_SYMBOL(blk_queue_find_tag);
+
+/**
+ * blk_free_tags - release a given set of tag maintenance info
+ * @bqt: the tag map to free
+ *
+ * Drop the reference count on @bqt and frees it when the last reference
+ * is dropped.
+ */
+void blk_free_tags(struct blk_queue_tag *bqt)
+{
+ if (atomic_dec_and_test(&bqt->refcnt)) {
+ BUG_ON(find_first_bit(bqt->tag_map, bqt->max_depth) <
+ bqt->max_depth);
+
+ kfree(bqt->tag_index);
+ bqt->tag_index = NULL;
+
+ kfree(bqt->tag_map);
+ bqt->tag_map = NULL;
+
+ kfree(bqt);
+ }
+}
+EXPORT_SYMBOL(blk_free_tags);
+
+/**
+ * __blk_queue_free_tags - release tag maintenance info
+ * @q: the request queue for the device
+ *
+ * Notes:
+ * blk_cleanup_queue() will take care of calling this function, if tagging
+ * has been used. So there's no need to call this directly.
+ **/
+void __blk_queue_free_tags(struct request_queue *q)
+{
+ struct blk_queue_tag *bqt = q->queue_tags;
+
+ if (!bqt)
+ return;
+
+ blk_free_tags(bqt);
+
+ q->queue_tags = NULL;
+ queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q);
+}
+
+/**
+ * blk_queue_free_tags - release tag maintenance info
+ * @q: the request queue for the device
+ *
+ * Notes:
+ * This is used to disable tagged queuing to a device, yet leave
+ * queue in function.
+ **/
+void blk_queue_free_tags(struct request_queue *q)
+{
+ queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q);
+}
+EXPORT_SYMBOL(blk_queue_free_tags);
+
+static int
+init_tag_map(struct request_queue *q, struct blk_queue_tag *tags, int depth)
+{
+ struct request **tag_index;
+ unsigned long *tag_map;
+ int nr_ulongs;
+
+ if (q && depth > q->nr_requests * 2) {
+ depth = q->nr_requests * 2;
+ printk(KERN_ERR "%s: adjusted depth to %d\n",
+ __func__, depth);
+ }
+
+ tag_index = kzalloc(depth * sizeof(struct request *), GFP_ATOMIC);
+ if (!tag_index)
+ goto fail;
+
+ nr_ulongs = ALIGN(depth, BITS_PER_LONG) / BITS_PER_LONG;
+ tag_map = kzalloc(nr_ulongs * sizeof(unsigned long), GFP_ATOMIC);
+ if (!tag_map)
+ goto fail;
+
+ tags->real_max_depth = depth;
+ tags->max_depth = depth;
+ tags->tag_index = tag_index;
+ tags->tag_map = tag_map;
+
+ return 0;
+fail:
+ kfree(tag_index);
+ return -ENOMEM;
+}
+
+static struct blk_queue_tag *__blk_queue_init_tags(struct request_queue *q,
+ int depth, int alloc_policy)
+{
+ struct blk_queue_tag *tags;
+
+ tags = kmalloc(sizeof(struct blk_queue_tag), GFP_ATOMIC);
+ if (!tags)
+ goto fail;
+
+ if (init_tag_map(q, tags, depth))
+ goto fail;
+
+ atomic_set(&tags->refcnt, 1);
+ tags->alloc_policy = alloc_policy;
+ tags->next_tag = 0;
+ return tags;
+fail:
+ kfree(tags);
+ return NULL;
+}
+
+/**
+ * blk_init_tags - initialize the tag info for an external tag map
+ * @depth: the maximum queue depth supported
+ * @alloc_policy: tag allocation policy
+ **/
+struct blk_queue_tag *blk_init_tags(int depth, int alloc_policy)
+{
+ return __blk_queue_init_tags(NULL, depth, alloc_policy);
+}
+EXPORT_SYMBOL(blk_init_tags);
+
+/**
+ * blk_queue_init_tags - initialize the queue tag info
+ * @q: the request queue for the device
+ * @depth: the maximum queue depth supported
+ * @tags: the tag to use
+ * @alloc_policy: tag allocation policy
+ *
+ * Queue lock must be held here if the function is called to resize an
+ * existing map.
+ **/
+int blk_queue_init_tags(struct request_queue *q, int depth,
+ struct blk_queue_tag *tags, int alloc_policy)
+{
+ int rc;
+
+ BUG_ON(tags && q->queue_tags && tags != q->queue_tags);
+
+ if (!tags && !q->queue_tags) {
+ tags = __blk_queue_init_tags(q, depth, alloc_policy);
+
+ if (!tags)
+ return -ENOMEM;
+
+ } else if (q->queue_tags) {
+ rc = blk_queue_resize_tags(q, depth);
+ if (rc)
+ return rc;
+ queue_flag_set(QUEUE_FLAG_QUEUED, q);
+ return 0;
+ } else
+ atomic_inc(&tags->refcnt);
+
+ /*
+ * assign it, all done
+ */
+ q->queue_tags = tags;
+ queue_flag_set_unlocked(QUEUE_FLAG_QUEUED, q);
+ INIT_LIST_HEAD(&q->tag_busy_list);
+ return 0;
+}
+EXPORT_SYMBOL(blk_queue_init_tags);
+
+/**
+ * blk_queue_resize_tags - change the queueing depth
+ * @q: the request queue for the device
+ * @new_depth: the new max command queueing depth
+ *
+ * Notes:
+ * Must be called with the queue lock held.
+ **/
+int blk_queue_resize_tags(struct request_queue *q, int new_depth)
+{
+ struct blk_queue_tag *bqt = q->queue_tags;
+ struct request **tag_index;
+ unsigned long *tag_map;
+ int max_depth, nr_ulongs;
+
+ if (!bqt)
+ return -ENXIO;
+
+ /*
+ * if we already have large enough real_max_depth. just
+ * adjust max_depth. *NOTE* as requests with tag value
+ * between new_depth and real_max_depth can be in-flight, tag
+ * map can not be shrunk blindly here.
+ */
+ if (new_depth <= bqt->real_max_depth) {
+ bqt->max_depth = new_depth;
+ return 0;
+ }
+
+ /*
+ * Currently cannot replace a shared tag map with a new
+ * one, so error out if this is the case
+ */
+ if (atomic_read(&bqt->refcnt) != 1)
+ return -EBUSY;
+
+ /*
+ * save the old state info, so we can copy it back
+ */
+ tag_index = bqt->tag_index;
+ tag_map = bqt->tag_map;
+ max_depth = bqt->real_max_depth;
+
+ if (init_tag_map(q, bqt, new_depth))
+ return -ENOMEM;
+
+ memcpy(bqt->tag_index, tag_index, max_depth * sizeof(struct request *));
+ nr_ulongs = ALIGN(max_depth, BITS_PER_LONG) / BITS_PER_LONG;
+ memcpy(bqt->tag_map, tag_map, nr_ulongs * sizeof(unsigned long));
+
+ kfree(tag_index);
+ kfree(tag_map);
+ return 0;
+}
+EXPORT_SYMBOL(blk_queue_resize_tags);
+
+/**
+ * blk_queue_end_tag - end tag operations for a request
+ * @q: the request queue for the device
+ * @rq: the request that has completed
+ *
+ * Description:
+ * Typically called when end_that_request_first() returns %0, meaning
+ * all transfers have been done for a request. It's important to call
+ * this function before end_that_request_last(), as that will put the
+ * request back on the free list thus corrupting the internal tag list.
+ **/
+void blk_queue_end_tag(struct request_queue *q, struct request *rq)
+{
+ struct blk_queue_tag *bqt = q->queue_tags;
+ unsigned tag = rq->tag; /* negative tags invalid */
+
+ lockdep_assert_held(q->queue_lock);
+
+ BUG_ON(tag >= bqt->real_max_depth);
+
+ list_del_init(&rq->queuelist);
+ rq->rq_flags &= ~RQF_QUEUED;
+ rq->tag = -1;
+ rq->internal_tag = -1;
+
+ if (unlikely(bqt->tag_index[tag] == NULL))
+ printk(KERN_ERR "%s: tag %d is missing\n",
+ __func__, tag);
+
+ bqt->tag_index[tag] = NULL;
+
+ if (unlikely(!test_bit(tag, bqt->tag_map))) {
+ printk(KERN_ERR "%s: attempt to clear non-busy tag (%d)\n",
+ __func__, tag);
+ return;
+ }
+ /*
+ * The tag_map bit acts as a lock for tag_index[bit], so we need
+ * unlock memory barrier semantics.
+ */
+ clear_bit_unlock(tag, bqt->tag_map);
+}
+
+/**
+ * blk_queue_start_tag - find a free tag and assign it
+ * @q: the request queue for the device
+ * @rq: the block request that needs tagging
+ *
+ * Description:
+ * This can either be used as a stand-alone helper, or possibly be
+ * assigned as the queue &prep_rq_fn (in which case &struct request
+ * automagically gets a tag assigned). Note that this function
+ * assumes that any type of request can be queued! if this is not
+ * true for your device, you must check the request type before
+ * calling this function. The request will also be removed from
+ * the request queue, so it's the drivers responsibility to readd
+ * it if it should need to be restarted for some reason.
+ **/
+int blk_queue_start_tag(struct request_queue *q, struct request *rq)
+{
+ struct blk_queue_tag *bqt = q->queue_tags;
+ unsigned max_depth;
+ int tag;
+
+ lockdep_assert_held(q->queue_lock);
+
+ if (unlikely((rq->rq_flags & RQF_QUEUED))) {
+ printk(KERN_ERR
+ "%s: request %p for device [%s] already tagged %d",
+ __func__, rq,
+ rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->tag);
+ BUG();
+ }
+
+ /*
+ * Protect against shared tag maps, as we may not have exclusive
+ * access to the tag map.
+ *
+ * We reserve a few tags just for sync IO, since we don't want
+ * to starve sync IO on behalf of flooding async IO.
+ */
+ max_depth = bqt->max_depth;
+ if (!rq_is_sync(rq) && max_depth > 1) {
+ switch (max_depth) {
+ case 2:
+ max_depth = 1;
+ break;
+ case 3:
+ max_depth = 2;
+ break;
+ default:
+ max_depth -= 2;
+ }
+ if (q->in_flight[BLK_RW_ASYNC] > max_depth)
+ return 1;
+ }
+
+ do {
+ if (bqt->alloc_policy == BLK_TAG_ALLOC_FIFO) {
+ tag = find_first_zero_bit(bqt->tag_map, max_depth);
+ if (tag >= max_depth)
+ return 1;
+ } else {
+ int start = bqt->next_tag;
+ int size = min_t(int, bqt->max_depth, max_depth + start);
+ tag = find_next_zero_bit(bqt->tag_map, size, start);
+ if (tag >= size && start + size > bqt->max_depth) {
+ size = start + size - bqt->max_depth;
+ tag = find_first_zero_bit(bqt->tag_map, size);
+ }
+ if (tag >= size)
+ return 1;
+ }
+
+ } while (test_and_set_bit_lock(tag, bqt->tag_map));
+ /*
+ * We need lock ordering semantics given by test_and_set_bit_lock.
+ * See blk_queue_end_tag for details.
+ */
+
+ bqt->next_tag = (tag + 1) % bqt->max_depth;
+ rq->rq_flags |= RQF_QUEUED;
+ rq->tag = tag;
+ bqt->tag_index[tag] = rq;
+ blk_start_request(rq);
+ list_add(&rq->queuelist, &q->tag_busy_list);
+ return 0;
+}
+EXPORT_SYMBOL(blk_queue_start_tag);
+
+/**
+ * blk_queue_invalidate_tags - invalidate all pending tags
+ * @q: the request queue for the device
+ *
+ * Description:
+ * Hardware conditions may dictate a need to stop all pending requests.
+ * In this case, we will safely clear the block side of the tag queue and
+ * readd all requests to the request queue in the right order.
+ **/
+void blk_queue_invalidate_tags(struct request_queue *q)
+{
+ struct list_head *tmp, *n;
+
+ lockdep_assert_held(q->queue_lock);
+
+ list_for_each_safe(tmp, n, &q->tag_busy_list)
+ blk_requeue_request(q, list_entry_rq(tmp));
+}
+EXPORT_SYMBOL(blk_queue_invalidate_tags);
diff --git a/src/kernel/linux/v4.14/block/blk-throttle.c b/src/kernel/linux/v4.14/block/blk-throttle.c
new file mode 100644
index 0000000..a8cd7b3
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-throttle.c
@@ -0,0 +1,2485 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Interface for controlling IO bandwidth on a request queue
+ *
+ * Copyright (C) 2010 Vivek Goyal <vgoyal@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/blktrace_api.h>
+#include <linux/blk-cgroup.h>
+#include "blk.h"
+
+/* Max dispatch from a group in 1 round */
+static int throtl_grp_quantum = 8;
+
+/* Total max dispatch from all groups in one round */
+static int throtl_quantum = 32;
+
+/* Throttling is performed over a slice and after that slice is renewed */
+#define DFL_THROTL_SLICE_HD (HZ / 10)
+#define DFL_THROTL_SLICE_SSD (HZ / 50)
+#define MAX_THROTL_SLICE (HZ)
+#define MAX_IDLE_TIME (5L * 1000 * 1000) /* 5 s */
+#define MIN_THROTL_BPS (320 * 1024)
+#define MIN_THROTL_IOPS (10)
+#define DFL_LATENCY_TARGET (-1L)
+#define DFL_IDLE_THRESHOLD (0)
+#define DFL_HD_BASELINE_LATENCY (4000L) /* 4ms */
+#define LATENCY_FILTERED_SSD (0)
+/*
+ * For HD, very small latency comes from sequential IO. Such IO is helpless to
+ * help determine if its IO is impacted by others, hence we ignore the IO
+ */
+#define LATENCY_FILTERED_HD (1000L) /* 1ms */
+
+#define SKIP_LATENCY (((u64)1) << BLK_STAT_RES_SHIFT)
+
+static struct blkcg_policy blkcg_policy_throtl;
+
+/* A workqueue to queue throttle related work */
+static struct workqueue_struct *kthrotld_workqueue;
+
+/*
+ * To implement hierarchical throttling, throtl_grps form a tree and bios
+ * are dispatched upwards level by level until they reach the top and get
+ * issued. When dispatching bios from the children and local group at each
+ * level, if the bios are dispatched into a single bio_list, there's a risk
+ * of a local or child group which can queue many bios at once filling up
+ * the list starving others.
+ *
+ * To avoid such starvation, dispatched bios are queued separately
+ * according to where they came from. When they are again dispatched to
+ * the parent, they're popped in round-robin order so that no single source
+ * hogs the dispatch window.
+ *
+ * throtl_qnode is used to keep the queued bios separated by their sources.
+ * Bios are queued to throtl_qnode which in turn is queued to
+ * throtl_service_queue and then dispatched in round-robin order.
+ *
+ * It's also used to track the reference counts on blkg's. A qnode always
+ * belongs to a throtl_grp and gets queued on itself or the parent, so
+ * incrementing the reference of the associated throtl_grp when a qnode is
+ * queued and decrementing when dequeued is enough to keep the whole blkg
+ * tree pinned while bios are in flight.
+ */
+struct throtl_qnode {
+ struct list_head node; /* service_queue->queued[] */
+ struct bio_list bios; /* queued bios */
+ struct throtl_grp *tg; /* tg this qnode belongs to */
+};
+
+struct throtl_service_queue {
+ struct throtl_service_queue *parent_sq; /* the parent service_queue */
+
+ /*
+ * Bios queued directly to this service_queue or dispatched from
+ * children throtl_grp's.
+ */
+ struct list_head queued[2]; /* throtl_qnode [READ/WRITE] */
+ unsigned int nr_queued[2]; /* number of queued bios */
+
+ /*
+ * RB tree of active children throtl_grp's, which are sorted by
+ * their ->disptime.
+ */
+ struct rb_root pending_tree; /* RB tree of active tgs */
+ struct rb_node *first_pending; /* first node in the tree */
+ unsigned int nr_pending; /* # queued in the tree */
+ unsigned long first_pending_disptime; /* disptime of the first tg */
+ struct timer_list pending_timer; /* fires on first_pending_disptime */
+};
+
+enum tg_state_flags {
+ THROTL_TG_PENDING = 1 << 0, /* on parent's pending tree */
+ THROTL_TG_WAS_EMPTY = 1 << 1, /* bio_lists[] became non-empty */
+};
+
+#define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node)
+
+enum {
+ LIMIT_LOW,
+ LIMIT_MAX,
+ LIMIT_CNT,
+};
+
+struct throtl_grp {
+ /* must be the first member */
+ struct blkg_policy_data pd;
+
+ /* active throtl group service_queue member */
+ struct rb_node rb_node;
+
+ /* throtl_data this group belongs to */
+ struct throtl_data *td;
+
+ /* this group's service queue */
+ struct throtl_service_queue service_queue;
+
+ /*
+ * qnode_on_self is used when bios are directly queued to this
+ * throtl_grp so that local bios compete fairly with bios
+ * dispatched from children. qnode_on_parent is used when bios are
+ * dispatched from this throtl_grp into its parent and will compete
+ * with the sibling qnode_on_parents and the parent's
+ * qnode_on_self.
+ */
+ struct throtl_qnode qnode_on_self[2];
+ struct throtl_qnode qnode_on_parent[2];
+
+ /*
+ * Dispatch time in jiffies. This is the estimated time when group
+ * will unthrottle and is ready to dispatch more bio. It is used as
+ * key to sort active groups in service tree.
+ */
+ unsigned long disptime;
+
+ unsigned int flags;
+
+ /* are there any throtl rules between this group and td? */
+ bool has_rules[2];
+
+ /* internally used bytes per second rate limits */
+ uint64_t bps[2][LIMIT_CNT];
+ /* user configured bps limits */
+ uint64_t bps_conf[2][LIMIT_CNT];
+
+ /* internally used IOPS limits */
+ unsigned int iops[2][LIMIT_CNT];
+ /* user configured IOPS limits */
+ unsigned int iops_conf[2][LIMIT_CNT];
+
+ /* Number of bytes disptached in current slice */
+ uint64_t bytes_disp[2];
+ /* Number of bio's dispatched in current slice */
+ unsigned int io_disp[2];
+
+ unsigned long last_low_overflow_time[2];
+
+ uint64_t last_bytes_disp[2];
+ unsigned int last_io_disp[2];
+
+ unsigned long last_check_time;
+
+ unsigned long latency_target; /* us */
+ unsigned long latency_target_conf; /* us */
+ /* When did we start a new slice */
+ unsigned long slice_start[2];
+ unsigned long slice_end[2];
+
+ unsigned long last_finish_time; /* ns / 1024 */
+ unsigned long checked_last_finish_time; /* ns / 1024 */
+ unsigned long avg_idletime; /* ns / 1024 */
+ unsigned long idletime_threshold; /* us */
+ unsigned long idletime_threshold_conf; /* us */
+
+ unsigned int bio_cnt; /* total bios */
+ unsigned int bad_bio_cnt; /* bios exceeding latency threshold */
+ unsigned long bio_cnt_reset_time;
+};
+
+/* We measure latency for request size from <= 4k to >= 1M */
+#define LATENCY_BUCKET_SIZE 9
+
+struct latency_bucket {
+ unsigned long total_latency; /* ns / 1024 */
+ int samples;
+};
+
+struct avg_latency_bucket {
+ unsigned long latency; /* ns / 1024 */
+ bool valid;
+};
+
+struct throtl_data
+{
+ /* service tree for active throtl groups */
+ struct throtl_service_queue service_queue;
+
+ struct request_queue *queue;
+
+ /* Total Number of queued bios on READ and WRITE lists */
+ unsigned int nr_queued[2];
+
+ unsigned int throtl_slice;
+
+ /* Work for dispatching throttled bios */
+ struct work_struct dispatch_work;
+ unsigned int limit_index;
+ bool limit_valid[LIMIT_CNT];
+
+ unsigned long low_upgrade_time;
+ unsigned long low_downgrade_time;
+
+ unsigned int scale;
+
+ struct latency_bucket tmp_buckets[LATENCY_BUCKET_SIZE];
+ struct avg_latency_bucket avg_buckets[LATENCY_BUCKET_SIZE];
+ struct latency_bucket __percpu *latency_buckets;
+ unsigned long last_calculate_time;
+ unsigned long filtered_latency;
+
+ bool track_bio_latency;
+};
+
+static void throtl_pending_timer_fn(unsigned long arg);
+
+static inline struct throtl_grp *pd_to_tg(struct blkg_policy_data *pd)
+{
+ return pd ? container_of(pd, struct throtl_grp, pd) : NULL;
+}
+
+static inline struct throtl_grp *blkg_to_tg(struct blkcg_gq *blkg)
+{
+ return pd_to_tg(blkg_to_pd(blkg, &blkcg_policy_throtl));
+}
+
+static inline struct blkcg_gq *tg_to_blkg(struct throtl_grp *tg)
+{
+ return pd_to_blkg(&tg->pd);
+}
+
+/**
+ * sq_to_tg - return the throl_grp the specified service queue belongs to
+ * @sq: the throtl_service_queue of interest
+ *
+ * Return the throtl_grp @sq belongs to. If @sq is the top-level one
+ * embedded in throtl_data, %NULL is returned.
+ */
+static struct throtl_grp *sq_to_tg(struct throtl_service_queue *sq)
+{
+ if (sq && sq->parent_sq)
+ return container_of(sq, struct throtl_grp, service_queue);
+ else
+ return NULL;
+}
+
+/**
+ * sq_to_td - return throtl_data the specified service queue belongs to
+ * @sq: the throtl_service_queue of interest
+ *
+ * A service_queue can be embedded in either a throtl_grp or throtl_data.
+ * Determine the associated throtl_data accordingly and return it.
+ */
+static struct throtl_data *sq_to_td(struct throtl_service_queue *sq)
+{
+ struct throtl_grp *tg = sq_to_tg(sq);
+
+ if (tg)
+ return tg->td;
+ else
+ return container_of(sq, struct throtl_data, service_queue);
+}
+
+/*
+ * cgroup's limit in LIMIT_MAX is scaled if low limit is set. This scale is to
+ * make the IO dispatch more smooth.
+ * Scale up: linearly scale up according to lapsed time since upgrade. For
+ * every throtl_slice, the limit scales up 1/2 .low limit till the
+ * limit hits .max limit
+ * Scale down: exponentially scale down if a cgroup doesn't hit its .low limit
+ */
+static uint64_t throtl_adjusted_limit(uint64_t low, struct throtl_data *td)
+{
+ /* arbitrary value to avoid too big scale */
+ if (td->scale < 4096 && time_after_eq(jiffies,
+ td->low_upgrade_time + td->scale * td->throtl_slice))
+ td->scale = (jiffies - td->low_upgrade_time) / td->throtl_slice;
+
+ return low + (low >> 1) * td->scale;
+}
+
+static uint64_t tg_bps_limit(struct throtl_grp *tg, int rw)
+{
+ struct blkcg_gq *blkg = tg_to_blkg(tg);
+ struct throtl_data *td;
+ uint64_t ret;
+
+ if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent)
+ return U64_MAX;
+
+ td = tg->td;
+ ret = tg->bps[rw][td->limit_index];
+ if (ret == 0 && td->limit_index == LIMIT_LOW) {
+ /* intermediate node or iops isn't 0 */
+ if (!list_empty(&blkg->blkcg->css.children) ||
+ tg->iops[rw][td->limit_index])
+ return U64_MAX;
+ else
+ return MIN_THROTL_BPS;
+ }
+
+ if (td->limit_index == LIMIT_MAX && tg->bps[rw][LIMIT_LOW] &&
+ tg->bps[rw][LIMIT_LOW] != tg->bps[rw][LIMIT_MAX]) {
+ uint64_t adjusted;
+
+ adjusted = throtl_adjusted_limit(tg->bps[rw][LIMIT_LOW], td);
+ ret = min(tg->bps[rw][LIMIT_MAX], adjusted);
+ }
+ return ret;
+}
+
+static unsigned int tg_iops_limit(struct throtl_grp *tg, int rw)
+{
+ struct blkcg_gq *blkg = tg_to_blkg(tg);
+ struct throtl_data *td;
+ unsigned int ret;
+
+ if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent)
+ return UINT_MAX;
+
+ td = tg->td;
+ ret = tg->iops[rw][td->limit_index];
+ if (ret == 0 && tg->td->limit_index == LIMIT_LOW) {
+ /* intermediate node or bps isn't 0 */
+ if (!list_empty(&blkg->blkcg->css.children) ||
+ tg->bps[rw][td->limit_index])
+ return UINT_MAX;
+ else
+ return MIN_THROTL_IOPS;
+ }
+
+ if (td->limit_index == LIMIT_MAX && tg->iops[rw][LIMIT_LOW] &&
+ tg->iops[rw][LIMIT_LOW] != tg->iops[rw][LIMIT_MAX]) {
+ uint64_t adjusted;
+
+ adjusted = throtl_adjusted_limit(tg->iops[rw][LIMIT_LOW], td);
+ if (adjusted > UINT_MAX)
+ adjusted = UINT_MAX;
+ ret = min_t(unsigned int, tg->iops[rw][LIMIT_MAX], adjusted);
+ }
+ return ret;
+}
+
+#define request_bucket_index(sectors) \
+ clamp_t(int, order_base_2(sectors) - 3, 0, LATENCY_BUCKET_SIZE - 1)
+
+/**
+ * throtl_log - log debug message via blktrace
+ * @sq: the service_queue being reported
+ * @fmt: printf format string
+ * @args: printf args
+ *
+ * The messages are prefixed with "throtl BLKG_NAME" if @sq belongs to a
+ * throtl_grp; otherwise, just "throtl".
+ */
+#define throtl_log(sq, fmt, args...) do { \
+ struct throtl_grp *__tg = sq_to_tg((sq)); \
+ struct throtl_data *__td = sq_to_td((sq)); \
+ \
+ (void)__td; \
+ if (likely(!blk_trace_note_message_enabled(__td->queue))) \
+ break; \
+ if ((__tg)) { \
+ blk_add_cgroup_trace_msg(__td->queue, \
+ tg_to_blkg(__tg)->blkcg, "throtl " fmt, ##args);\
+ } else { \
+ blk_add_trace_msg(__td->queue, "throtl " fmt, ##args); \
+ } \
+} while (0)
+
+static inline unsigned int throtl_bio_data_size(struct bio *bio)
+{
+ /* assume it's one sector */
+ if (unlikely(bio_op(bio) == REQ_OP_DISCARD))
+ return 512;
+ return bio->bi_iter.bi_size;
+}
+
+static void throtl_qnode_init(struct throtl_qnode *qn, struct throtl_grp *tg)
+{
+ INIT_LIST_HEAD(&qn->node);
+ bio_list_init(&qn->bios);
+ qn->tg = tg;
+}
+
+/**
+ * throtl_qnode_add_bio - add a bio to a throtl_qnode and activate it
+ * @bio: bio being added
+ * @qn: qnode to add bio to
+ * @queued: the service_queue->queued[] list @qn belongs to
+ *
+ * Add @bio to @qn and put @qn on @queued if it's not already on.
+ * @qn->tg's reference count is bumped when @qn is activated. See the
+ * comment on top of throtl_qnode definition for details.
+ */
+static void throtl_qnode_add_bio(struct bio *bio, struct throtl_qnode *qn,
+ struct list_head *queued)
+{
+ bio_list_add(&qn->bios, bio);
+ if (list_empty(&qn->node)) {
+ list_add_tail(&qn->node, queued);
+ blkg_get(tg_to_blkg(qn->tg));
+ }
+}
+
+/**
+ * throtl_peek_queued - peek the first bio on a qnode list
+ * @queued: the qnode list to peek
+ */
+static struct bio *throtl_peek_queued(struct list_head *queued)
+{
+ struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node);
+ struct bio *bio;
+
+ if (list_empty(queued))
+ return NULL;
+
+ bio = bio_list_peek(&qn->bios);
+ WARN_ON_ONCE(!bio);
+ return bio;
+}
+
+/**
+ * throtl_pop_queued - pop the first bio form a qnode list
+ * @queued: the qnode list to pop a bio from
+ * @tg_to_put: optional out argument for throtl_grp to put
+ *
+ * Pop the first bio from the qnode list @queued. After popping, the first
+ * qnode is removed from @queued if empty or moved to the end of @queued so
+ * that the popping order is round-robin.
+ *
+ * When the first qnode is removed, its associated throtl_grp should be put
+ * too. If @tg_to_put is NULL, this function automatically puts it;
+ * otherwise, *@tg_to_put is set to the throtl_grp to put and the caller is
+ * responsible for putting it.
+ */
+static struct bio *throtl_pop_queued(struct list_head *queued,
+ struct throtl_grp **tg_to_put)
+{
+ struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node);
+ struct bio *bio;
+
+ if (list_empty(queued))
+ return NULL;
+
+ bio = bio_list_pop(&qn->bios);
+ WARN_ON_ONCE(!bio);
+
+ if (bio_list_empty(&qn->bios)) {
+ list_del_init(&qn->node);
+ if (tg_to_put)
+ *tg_to_put = qn->tg;
+ else
+ blkg_put(tg_to_blkg(qn->tg));
+ } else {
+ list_move_tail(&qn->node, queued);
+ }
+
+ return bio;
+}
+
+/* init a service_queue, assumes the caller zeroed it */
+static void throtl_service_queue_init(struct throtl_service_queue *sq)
+{
+ INIT_LIST_HEAD(&sq->queued[0]);
+ INIT_LIST_HEAD(&sq->queued[1]);
+ sq->pending_tree = RB_ROOT;
+ setup_timer(&sq->pending_timer, throtl_pending_timer_fn,
+ (unsigned long)sq);
+}
+
+static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)
+{
+ struct throtl_grp *tg;
+ int rw;
+
+ tg = kzalloc_node(sizeof(*tg), gfp, node);
+ if (!tg)
+ return NULL;
+
+ throtl_service_queue_init(&tg->service_queue);
+
+ for (rw = READ; rw <= WRITE; rw++) {
+ throtl_qnode_init(&tg->qnode_on_self[rw], tg);
+ throtl_qnode_init(&tg->qnode_on_parent[rw], tg);
+ }
+
+ RB_CLEAR_NODE(&tg->rb_node);
+ tg->bps[READ][LIMIT_MAX] = U64_MAX;
+ tg->bps[WRITE][LIMIT_MAX] = U64_MAX;
+ tg->iops[READ][LIMIT_MAX] = UINT_MAX;
+ tg->iops[WRITE][LIMIT_MAX] = UINT_MAX;
+ tg->bps_conf[READ][LIMIT_MAX] = U64_MAX;
+ tg->bps_conf[WRITE][LIMIT_MAX] = U64_MAX;
+ tg->iops_conf[READ][LIMIT_MAX] = UINT_MAX;
+ tg->iops_conf[WRITE][LIMIT_MAX] = UINT_MAX;
+ /* LIMIT_LOW will have default value 0 */
+
+ tg->latency_target = DFL_LATENCY_TARGET;
+ tg->latency_target_conf = DFL_LATENCY_TARGET;
+ tg->idletime_threshold = DFL_IDLE_THRESHOLD;
+ tg->idletime_threshold_conf = DFL_IDLE_THRESHOLD;
+
+ return &tg->pd;
+}
+
+static void throtl_pd_init(struct blkg_policy_data *pd)
+{
+ struct throtl_grp *tg = pd_to_tg(pd);
+ struct blkcg_gq *blkg = tg_to_blkg(tg);
+ struct throtl_data *td = blkg->q->td;
+ struct throtl_service_queue *sq = &tg->service_queue;
+
+ /*
+ * If on the default hierarchy, we switch to properly hierarchical
+ * behavior where limits on a given throtl_grp are applied to the
+ * whole subtree rather than just the group itself. e.g. If 16M
+ * read_bps limit is set on the root group, the whole system can't
+ * exceed 16M for the device.
+ *
+ * If not on the default hierarchy, the broken flat hierarchy
+ * behavior is retained where all throtl_grps are treated as if
+ * they're all separate root groups right below throtl_data.
+ * Limits of a group don't interact with limits of other groups
+ * regardless of the position of the group in the hierarchy.
+ */
+ sq->parent_sq = &td->service_queue;
+ if (cgroup_subsys_on_dfl(io_cgrp_subsys) && blkg->parent)
+ sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue;
+ tg->td = td;
+}
+
+/*
+ * Set has_rules[] if @tg or any of its parents have limits configured.
+ * This doesn't require walking up to the top of the hierarchy as the
+ * parent's has_rules[] is guaranteed to be correct.
+ */
+static void tg_update_has_rules(struct throtl_grp *tg)
+{
+ struct throtl_grp *parent_tg = sq_to_tg(tg->service_queue.parent_sq);
+ struct throtl_data *td = tg->td;
+ int rw;
+
+ for (rw = READ; rw <= WRITE; rw++)
+ tg->has_rules[rw] = (parent_tg && parent_tg->has_rules[rw]) ||
+ (td->limit_valid[td->limit_index] &&
+ (tg_bps_limit(tg, rw) != U64_MAX ||
+ tg_iops_limit(tg, rw) != UINT_MAX));
+}
+
+static void throtl_pd_online(struct blkg_policy_data *pd)
+{
+ struct throtl_grp *tg = pd_to_tg(pd);
+ /*
+ * We don't want new groups to escape the limits of its ancestors.
+ * Update has_rules[] after a new group is brought online.
+ */
+ tg_update_has_rules(tg);
+}
+
+static void blk_throtl_update_limit_valid(struct throtl_data *td)
+{
+ struct cgroup_subsys_state *pos_css;
+ struct blkcg_gq *blkg;
+ bool low_valid = false;
+
+ rcu_read_lock();
+ blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) {
+ struct throtl_grp *tg = blkg_to_tg(blkg);
+
+ if (tg->bps[READ][LIMIT_LOW] || tg->bps[WRITE][LIMIT_LOW] ||
+ tg->iops[READ][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW])
+ low_valid = true;
+ }
+ rcu_read_unlock();
+
+ td->limit_valid[LIMIT_LOW] = low_valid;
+}
+
+static void throtl_upgrade_state(struct throtl_data *td);
+static void throtl_pd_offline(struct blkg_policy_data *pd)
+{
+ struct throtl_grp *tg = pd_to_tg(pd);
+
+ tg->bps[READ][LIMIT_LOW] = 0;
+ tg->bps[WRITE][LIMIT_LOW] = 0;
+ tg->iops[READ][LIMIT_LOW] = 0;
+ tg->iops[WRITE][LIMIT_LOW] = 0;
+
+ blk_throtl_update_limit_valid(tg->td);
+
+ if (!tg->td->limit_valid[tg->td->limit_index])
+ throtl_upgrade_state(tg->td);
+}
+
+static void throtl_pd_free(struct blkg_policy_data *pd)
+{
+ struct throtl_grp *tg = pd_to_tg(pd);
+
+ del_timer_sync(&tg->service_queue.pending_timer);
+ kfree(tg);
+}
+
+static struct throtl_grp *
+throtl_rb_first(struct throtl_service_queue *parent_sq)
+{
+ /* Service tree is empty */
+ if (!parent_sq->nr_pending)
+ return NULL;
+
+ if (!parent_sq->first_pending)
+ parent_sq->first_pending = rb_first(&parent_sq->pending_tree);
+
+ if (parent_sq->first_pending)
+ return rb_entry_tg(parent_sq->first_pending);
+
+ return NULL;
+}
+
+static void rb_erase_init(struct rb_node *n, struct rb_root *root)
+{
+ rb_erase(n, root);
+ RB_CLEAR_NODE(n);
+}
+
+static void throtl_rb_erase(struct rb_node *n,
+ struct throtl_service_queue *parent_sq)
+{
+ if (parent_sq->first_pending == n)
+ parent_sq->first_pending = NULL;
+ rb_erase_init(n, &parent_sq->pending_tree);
+ --parent_sq->nr_pending;
+}
+
+static void update_min_dispatch_time(struct throtl_service_queue *parent_sq)
+{
+ struct throtl_grp *tg;
+
+ tg = throtl_rb_first(parent_sq);
+ if (!tg)
+ return;
+
+ parent_sq->first_pending_disptime = tg->disptime;
+}
+
+static void tg_service_queue_add(struct throtl_grp *tg)
+{
+ struct throtl_service_queue *parent_sq = tg->service_queue.parent_sq;
+ struct rb_node **node = &parent_sq->pending_tree.rb_node;
+ struct rb_node *parent = NULL;
+ struct throtl_grp *__tg;
+ unsigned long key = tg->disptime;
+ int left = 1;
+
+ while (*node != NULL) {
+ parent = *node;
+ __tg = rb_entry_tg(parent);
+
+ if (time_before(key, __tg->disptime))
+ node = &parent->rb_left;
+ else {
+ node = &parent->rb_right;
+ left = 0;
+ }
+ }
+
+ if (left)
+ parent_sq->first_pending = &tg->rb_node;
+
+ rb_link_node(&tg->rb_node, parent, node);
+ rb_insert_color(&tg->rb_node, &parent_sq->pending_tree);
+}
+
+static void __throtl_enqueue_tg(struct throtl_grp *tg)
+{
+ tg_service_queue_add(tg);
+ tg->flags |= THROTL_TG_PENDING;
+ tg->service_queue.parent_sq->nr_pending++;
+}
+
+static void throtl_enqueue_tg(struct throtl_grp *tg)
+{
+ if (!(tg->flags & THROTL_TG_PENDING))
+ __throtl_enqueue_tg(tg);
+}
+
+static void __throtl_dequeue_tg(struct throtl_grp *tg)
+{
+ throtl_rb_erase(&tg->rb_node, tg->service_queue.parent_sq);
+ tg->flags &= ~THROTL_TG_PENDING;
+}
+
+static void throtl_dequeue_tg(struct throtl_grp *tg)
+{
+ if (tg->flags & THROTL_TG_PENDING)
+ __throtl_dequeue_tg(tg);
+}
+
+/* Call with queue lock held */
+static void throtl_schedule_pending_timer(struct throtl_service_queue *sq,
+ unsigned long expires)
+{
+ unsigned long max_expire = jiffies + 8 * sq_to_td(sq)->throtl_slice;
+
+ /*
+ * Since we are adjusting the throttle limit dynamically, the sleep
+ * time calculated according to previous limit might be invalid. It's
+ * possible the cgroup sleep time is very long and no other cgroups
+ * have IO running so notify the limit changes. Make sure the cgroup
+ * doesn't sleep too long to avoid the missed notification.
+ */
+ if (time_after(expires, max_expire))
+ expires = max_expire;
+ mod_timer(&sq->pending_timer, expires);
+ throtl_log(sq, "schedule timer. delay=%lu jiffies=%lu",
+ expires - jiffies, jiffies);
+}
+
+/**
+ * throtl_schedule_next_dispatch - schedule the next dispatch cycle
+ * @sq: the service_queue to schedule dispatch for
+ * @force: force scheduling
+ *
+ * Arm @sq->pending_timer so that the next dispatch cycle starts on the
+ * dispatch time of the first pending child. Returns %true if either timer
+ * is armed or there's no pending child left. %false if the current
+ * dispatch window is still open and the caller should continue
+ * dispatching.
+ *
+ * If @force is %true, the dispatch timer is always scheduled and this
+ * function is guaranteed to return %true. This is to be used when the
+ * caller can't dispatch itself and needs to invoke pending_timer
+ * unconditionally. Note that forced scheduling is likely to induce short
+ * delay before dispatch starts even if @sq->first_pending_disptime is not
+ * in the future and thus shouldn't be used in hot paths.
+ */
+static bool throtl_schedule_next_dispatch(struct throtl_service_queue *sq,
+ bool force)
+{
+ /* any pending children left? */
+ if (!sq->nr_pending)
+ return true;
+
+ update_min_dispatch_time(sq);
+
+ /* is the next dispatch time in the future? */
+ if (force || time_after(sq->first_pending_disptime, jiffies)) {
+ throtl_schedule_pending_timer(sq, sq->first_pending_disptime);
+ return true;
+ }
+
+ /* tell the caller to continue dispatching */
+ return false;
+}
+
+static inline void throtl_start_new_slice_with_credit(struct throtl_grp *tg,
+ bool rw, unsigned long start)
+{
+ tg->bytes_disp[rw] = 0;
+ tg->io_disp[rw] = 0;
+
+ /*
+ * Previous slice has expired. We must have trimmed it after last
+ * bio dispatch. That means since start of last slice, we never used
+ * that bandwidth. Do try to make use of that bandwidth while giving
+ * credit.
+ */
+ if (time_after_eq(start, tg->slice_start[rw]))
+ tg->slice_start[rw] = start;
+
+ tg->slice_end[rw] = jiffies + tg->td->throtl_slice;
+ throtl_log(&tg->service_queue,
+ "[%c] new slice with credit start=%lu end=%lu jiffies=%lu",
+ rw == READ ? 'R' : 'W', tg->slice_start[rw],
+ tg->slice_end[rw], jiffies);
+}
+
+static inline void throtl_start_new_slice(struct throtl_grp *tg, bool rw)
+{
+ tg->bytes_disp[rw] = 0;
+ tg->io_disp[rw] = 0;
+ tg->slice_start[rw] = jiffies;
+ tg->slice_end[rw] = jiffies + tg->td->throtl_slice;
+ throtl_log(&tg->service_queue,
+ "[%c] new slice start=%lu end=%lu jiffies=%lu",
+ rw == READ ? 'R' : 'W', tg->slice_start[rw],
+ tg->slice_end[rw], jiffies);
+}
+
+static inline void throtl_set_slice_end(struct throtl_grp *tg, bool rw,
+ unsigned long jiffy_end)
+{
+ tg->slice_end[rw] = roundup(jiffy_end, tg->td->throtl_slice);
+}
+
+static inline void throtl_extend_slice(struct throtl_grp *tg, bool rw,
+ unsigned long jiffy_end)
+{
+ tg->slice_end[rw] = roundup(jiffy_end, tg->td->throtl_slice);
+ throtl_log(&tg->service_queue,
+ "[%c] extend slice start=%lu end=%lu jiffies=%lu",
+ rw == READ ? 'R' : 'W', tg->slice_start[rw],
+ tg->slice_end[rw], jiffies);
+}
+
+/* Determine if previously allocated or extended slice is complete or not */
+static bool throtl_slice_used(struct throtl_grp *tg, bool rw)
+{
+ if (time_in_range(jiffies, tg->slice_start[rw], tg->slice_end[rw]))
+ return false;
+
+ return 1;
+}
+
+/* Trim the used slices and adjust slice start accordingly */
+static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw)
+{
+ unsigned long nr_slices, time_elapsed, io_trim;
+ u64 bytes_trim, tmp;
+
+ BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw]));
+
+ /*
+ * If bps are unlimited (-1), then time slice don't get
+ * renewed. Don't try to trim the slice if slice is used. A new
+ * slice will start when appropriate.
+ */
+ if (throtl_slice_used(tg, rw))
+ return;
+
+ /*
+ * A bio has been dispatched. Also adjust slice_end. It might happen
+ * that initially cgroup limit was very low resulting in high
+ * slice_end, but later limit was bumped up and bio was dispached
+ * sooner, then we need to reduce slice_end. A high bogus slice_end
+ * is bad because it does not allow new slice to start.
+ */
+
+ throtl_set_slice_end(tg, rw, jiffies + tg->td->throtl_slice);
+
+ time_elapsed = jiffies - tg->slice_start[rw];
+
+ nr_slices = time_elapsed / tg->td->throtl_slice;
+
+ if (!nr_slices)
+ return;
+ tmp = tg_bps_limit(tg, rw) * tg->td->throtl_slice * nr_slices;
+ do_div(tmp, HZ);
+ bytes_trim = tmp;
+
+ io_trim = (tg_iops_limit(tg, rw) * tg->td->throtl_slice * nr_slices) /
+ HZ;
+
+ if (!bytes_trim && !io_trim)
+ return;
+
+ if (tg->bytes_disp[rw] >= bytes_trim)
+ tg->bytes_disp[rw] -= bytes_trim;
+ else
+ tg->bytes_disp[rw] = 0;
+
+ if (tg->io_disp[rw] >= io_trim)
+ tg->io_disp[rw] -= io_trim;
+ else
+ tg->io_disp[rw] = 0;
+
+ tg->slice_start[rw] += nr_slices * tg->td->throtl_slice;
+
+ throtl_log(&tg->service_queue,
+ "[%c] trim slice nr=%lu bytes=%llu io=%lu start=%lu end=%lu jiffies=%lu",
+ rw == READ ? 'R' : 'W', nr_slices, bytes_trim, io_trim,
+ tg->slice_start[rw], tg->slice_end[rw], jiffies);
+}
+
+static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio,
+ unsigned long *wait)
+{
+ bool rw = bio_data_dir(bio);
+ unsigned int io_allowed;
+ unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd;
+ u64 tmp;
+
+ jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw];
+
+ /* Slice has just started. Consider one slice interval */
+ if (!jiffy_elapsed)
+ jiffy_elapsed_rnd = tg->td->throtl_slice;
+
+ jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, tg->td->throtl_slice);
+
+ /*
+ * jiffy_elapsed_rnd should not be a big value as minimum iops can be
+ * 1 then at max jiffy elapsed should be equivalent of 1 second as we
+ * will allow dispatch after 1 second and after that slice should
+ * have been trimmed.
+ */
+
+ tmp = (u64)tg_iops_limit(tg, rw) * jiffy_elapsed_rnd;
+ do_div(tmp, HZ);
+
+ if (tmp > UINT_MAX)
+ io_allowed = UINT_MAX;
+ else
+ io_allowed = tmp;
+
+ if (tg->io_disp[rw] + 1 <= io_allowed) {
+ if (wait)
+ *wait = 0;
+ return true;
+ }
+
+ /* Calc approx time to dispatch */
+ jiffy_wait = ((tg->io_disp[rw] + 1) * HZ) / tg_iops_limit(tg, rw) + 1;
+
+ if (jiffy_wait > jiffy_elapsed)
+ jiffy_wait = jiffy_wait - jiffy_elapsed;
+ else
+ jiffy_wait = 1;
+
+ if (wait)
+ *wait = jiffy_wait;
+ return 0;
+}
+
+static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio,
+ unsigned long *wait)
+{
+ bool rw = bio_data_dir(bio);
+ u64 bytes_allowed, extra_bytes, tmp;
+ unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd;
+ unsigned int bio_size = throtl_bio_data_size(bio);
+
+ jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw];
+
+ /* Slice has just started. Consider one slice interval */
+ if (!jiffy_elapsed)
+ jiffy_elapsed_rnd = tg->td->throtl_slice;
+
+ jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, tg->td->throtl_slice);
+
+ tmp = tg_bps_limit(tg, rw) * jiffy_elapsed_rnd;
+ do_div(tmp, HZ);
+ bytes_allowed = tmp;
+
+ if (tg->bytes_disp[rw] + bio_size <= bytes_allowed) {
+ if (wait)
+ *wait = 0;
+ return true;
+ }
+
+ /* Calc approx time to dispatch */
+ extra_bytes = tg->bytes_disp[rw] + bio_size - bytes_allowed;
+ jiffy_wait = div64_u64(extra_bytes * HZ, tg_bps_limit(tg, rw));
+
+ if (!jiffy_wait)
+ jiffy_wait = 1;
+
+ /*
+ * This wait time is without taking into consideration the rounding
+ * up we did. Add that time also.
+ */
+ jiffy_wait = jiffy_wait + (jiffy_elapsed_rnd - jiffy_elapsed);
+ if (wait)
+ *wait = jiffy_wait;
+ return 0;
+}
+
+/*
+ * Returns whether one can dispatch a bio or not. Also returns approx number
+ * of jiffies to wait before this bio is with-in IO rate and can be dispatched
+ */
+static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio,
+ unsigned long *wait)
+{
+ bool rw = bio_data_dir(bio);
+ unsigned long bps_wait = 0, iops_wait = 0, max_wait = 0;
+
+ /*
+ * Currently whole state machine of group depends on first bio
+ * queued in the group bio list. So one should not be calling
+ * this function with a different bio if there are other bios
+ * queued.
+ */
+ BUG_ON(tg->service_queue.nr_queued[rw] &&
+ bio != throtl_peek_queued(&tg->service_queue.queued[rw]));
+
+ /* If tg->bps = -1, then BW is unlimited */
+ if (tg_bps_limit(tg, rw) == U64_MAX &&
+ tg_iops_limit(tg, rw) == UINT_MAX) {
+ if (wait)
+ *wait = 0;
+ return true;
+ }
+
+ /*
+ * If previous slice expired, start a new one otherwise renew/extend
+ * existing slice to make sure it is at least throtl_slice interval
+ * long since now. New slice is started only for empty throttle group.
+ * If there is queued bio, that means there should be an active
+ * slice and it should be extended instead.
+ */
+ if (throtl_slice_used(tg, rw) && !(tg->service_queue.nr_queued[rw]))
+ throtl_start_new_slice(tg, rw);
+ else {
+ if (time_before(tg->slice_end[rw],
+ jiffies + tg->td->throtl_slice))
+ throtl_extend_slice(tg, rw,
+ jiffies + tg->td->throtl_slice);
+ }
+
+ if (tg_with_in_bps_limit(tg, bio, &bps_wait) &&
+ tg_with_in_iops_limit(tg, bio, &iops_wait)) {
+ if (wait)
+ *wait = 0;
+ return 1;
+ }
+
+ max_wait = max(bps_wait, iops_wait);
+
+ if (wait)
+ *wait = max_wait;
+
+ if (time_before(tg->slice_end[rw], jiffies + max_wait))
+ throtl_extend_slice(tg, rw, jiffies + max_wait);
+
+ return 0;
+}
+
+static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio)
+{
+ bool rw = bio_data_dir(bio);
+ unsigned int bio_size = throtl_bio_data_size(bio);
+
+ /* Charge the bio to the group */
+ tg->bytes_disp[rw] += bio_size;
+ tg->io_disp[rw]++;
+ tg->last_bytes_disp[rw] += bio_size;
+ tg->last_io_disp[rw]++;
+
+ /*
+ * BIO_THROTTLED is used to prevent the same bio to be throttled
+ * more than once as a throttled bio will go through blk-throtl the
+ * second time when it eventually gets issued. Set it when a bio
+ * is being charged to a tg.
+ */
+ if (!bio_flagged(bio, BIO_THROTTLED))
+ bio_set_flag(bio, BIO_THROTTLED);
+}
+
+/**
+ * throtl_add_bio_tg - add a bio to the specified throtl_grp
+ * @bio: bio to add
+ * @qn: qnode to use
+ * @tg: the target throtl_grp
+ *
+ * Add @bio to @tg's service_queue using @qn. If @qn is not specified,
+ * tg->qnode_on_self[] is used.
+ */
+static void throtl_add_bio_tg(struct bio *bio, struct throtl_qnode *qn,
+ struct throtl_grp *tg)
+{
+ struct throtl_service_queue *sq = &tg->service_queue;
+ bool rw = bio_data_dir(bio);
+
+ if (!qn)
+ qn = &tg->qnode_on_self[rw];
+
+ /*
+ * If @tg doesn't currently have any bios queued in the same
+ * direction, queueing @bio can change when @tg should be
+ * dispatched. Mark that @tg was empty. This is automatically
+ * cleaered on the next tg_update_disptime().
+ */
+ if (!sq->nr_queued[rw])
+ tg->flags |= THROTL_TG_WAS_EMPTY;
+
+ throtl_qnode_add_bio(bio, qn, &sq->queued[rw]);
+
+ sq->nr_queued[rw]++;
+ throtl_enqueue_tg(tg);
+}
+
+static void tg_update_disptime(struct throtl_grp *tg)
+{
+ struct throtl_service_queue *sq = &tg->service_queue;
+ unsigned long read_wait = -1, write_wait = -1, min_wait = -1, disptime;
+ struct bio *bio;
+
+ bio = throtl_peek_queued(&sq->queued[READ]);
+ if (bio)
+ tg_may_dispatch(tg, bio, &read_wait);
+
+ bio = throtl_peek_queued(&sq->queued[WRITE]);
+ if (bio)
+ tg_may_dispatch(tg, bio, &write_wait);
+
+ min_wait = min(read_wait, write_wait);
+ disptime = jiffies + min_wait;
+
+ /* Update dispatch time */
+ throtl_dequeue_tg(tg);
+ tg->disptime = disptime;
+ throtl_enqueue_tg(tg);
+
+ /* see throtl_add_bio_tg() */
+ tg->flags &= ~THROTL_TG_WAS_EMPTY;
+}
+
+static void start_parent_slice_with_credit(struct throtl_grp *child_tg,
+ struct throtl_grp *parent_tg, bool rw)
+{
+ if (throtl_slice_used(parent_tg, rw)) {
+ throtl_start_new_slice_with_credit(parent_tg, rw,
+ child_tg->slice_start[rw]);
+ }
+
+}
+
+static void tg_dispatch_one_bio(struct throtl_grp *tg, bool rw)
+{
+ struct throtl_service_queue *sq = &tg->service_queue;
+ struct throtl_service_queue *parent_sq = sq->parent_sq;
+ struct throtl_grp *parent_tg = sq_to_tg(parent_sq);
+ struct throtl_grp *tg_to_put = NULL;
+ struct bio *bio;
+
+ /*
+ * @bio is being transferred from @tg to @parent_sq. Popping a bio
+ * from @tg may put its reference and @parent_sq might end up
+ * getting released prematurely. Remember the tg to put and put it
+ * after @bio is transferred to @parent_sq.
+ */
+ bio = throtl_pop_queued(&sq->queued[rw], &tg_to_put);
+ sq->nr_queued[rw]--;
+
+ throtl_charge_bio(tg, bio);
+
+ /*
+ * If our parent is another tg, we just need to transfer @bio to
+ * the parent using throtl_add_bio_tg(). If our parent is
+ * @td->service_queue, @bio is ready to be issued. Put it on its
+ * bio_lists[] and decrease total number queued. The caller is
+ * responsible for issuing these bios.
+ */
+ if (parent_tg) {
+ throtl_add_bio_tg(bio, &tg->qnode_on_parent[rw], parent_tg);
+ start_parent_slice_with_credit(tg, parent_tg, rw);
+ } else {
+ throtl_qnode_add_bio(bio, &tg->qnode_on_parent[rw],
+ &parent_sq->queued[rw]);
+ BUG_ON(tg->td->nr_queued[rw] <= 0);
+ tg->td->nr_queued[rw]--;
+ }
+
+ throtl_trim_slice(tg, rw);
+
+ if (tg_to_put)
+ blkg_put(tg_to_blkg(tg_to_put));
+}
+
+static int throtl_dispatch_tg(struct throtl_grp *tg)
+{
+ struct throtl_service_queue *sq = &tg->service_queue;
+ unsigned int nr_reads = 0, nr_writes = 0;
+ unsigned int max_nr_reads = throtl_grp_quantum*3/4;
+ unsigned int max_nr_writes = throtl_grp_quantum - max_nr_reads;
+ struct bio *bio;
+
+ /* Try to dispatch 75% READS and 25% WRITES */
+
+ while ((bio = throtl_peek_queued(&sq->queued[READ])) &&
+ tg_may_dispatch(tg, bio, NULL)) {
+
+ tg_dispatch_one_bio(tg, bio_data_dir(bio));
+ nr_reads++;
+
+ if (nr_reads >= max_nr_reads)
+ break;
+ }
+
+ while ((bio = throtl_peek_queued(&sq->queued[WRITE])) &&
+ tg_may_dispatch(tg, bio, NULL)) {
+
+ tg_dispatch_one_bio(tg, bio_data_dir(bio));
+ nr_writes++;
+
+ if (nr_writes >= max_nr_writes)
+ break;
+ }
+
+ return nr_reads + nr_writes;
+}
+
+static int throtl_select_dispatch(struct throtl_service_queue *parent_sq)
+{
+ unsigned int nr_disp = 0;
+
+ while (1) {
+ struct throtl_grp *tg = throtl_rb_first(parent_sq);
+ struct throtl_service_queue *sq = &tg->service_queue;
+
+ if (!tg)
+ break;
+
+ if (time_before(jiffies, tg->disptime))
+ break;
+
+ throtl_dequeue_tg(tg);
+
+ nr_disp += throtl_dispatch_tg(tg);
+
+ if (sq->nr_queued[0] || sq->nr_queued[1])
+ tg_update_disptime(tg);
+
+ if (nr_disp >= throtl_quantum)
+ break;
+ }
+
+ return nr_disp;
+}
+
+static bool throtl_can_upgrade(struct throtl_data *td,
+ struct throtl_grp *this_tg);
+/**
+ * throtl_pending_timer_fn - timer function for service_queue->pending_timer
+ * @arg: the throtl_service_queue being serviced
+ *
+ * This timer is armed when a child throtl_grp with active bio's become
+ * pending and queued on the service_queue's pending_tree and expires when
+ * the first child throtl_grp should be dispatched. This function
+ * dispatches bio's from the children throtl_grps to the parent
+ * service_queue.
+ *
+ * If the parent's parent is another throtl_grp, dispatching is propagated
+ * by either arming its pending_timer or repeating dispatch directly. If
+ * the top-level service_tree is reached, throtl_data->dispatch_work is
+ * kicked so that the ready bio's are issued.
+ */
+static void throtl_pending_timer_fn(unsigned long arg)
+{
+ struct throtl_service_queue *sq = (void *)arg;
+ struct throtl_grp *tg = sq_to_tg(sq);
+ struct throtl_data *td = sq_to_td(sq);
+ struct request_queue *q = td->queue;
+ struct throtl_service_queue *parent_sq;
+ bool dispatched;
+ int ret;
+
+ spin_lock_irq(q->queue_lock);
+ if (throtl_can_upgrade(td, NULL))
+ throtl_upgrade_state(td);
+
+again:
+ parent_sq = sq->parent_sq;
+ dispatched = false;
+
+ while (true) {
+ throtl_log(sq, "dispatch nr_queued=%u read=%u write=%u",
+ sq->nr_queued[READ] + sq->nr_queued[WRITE],
+ sq->nr_queued[READ], sq->nr_queued[WRITE]);
+
+ ret = throtl_select_dispatch(sq);
+ if (ret) {
+ throtl_log(sq, "bios disp=%u", ret);
+ dispatched = true;
+ }
+
+ if (throtl_schedule_next_dispatch(sq, false))
+ break;
+
+ /* this dispatch windows is still open, relax and repeat */
+ spin_unlock_irq(q->queue_lock);
+ cpu_relax();
+ spin_lock_irq(q->queue_lock);
+ }
+
+ if (!dispatched)
+ goto out_unlock;
+
+ if (parent_sq) {
+ /* @parent_sq is another throl_grp, propagate dispatch */
+ if (tg->flags & THROTL_TG_WAS_EMPTY) {
+ tg_update_disptime(tg);
+ if (!throtl_schedule_next_dispatch(parent_sq, false)) {
+ /* window is already open, repeat dispatching */
+ sq = parent_sq;
+ tg = sq_to_tg(sq);
+ goto again;
+ }
+ }
+ } else {
+ /* reached the top-level, queue issueing */
+ queue_work(kthrotld_workqueue, &td->dispatch_work);
+ }
+out_unlock:
+ spin_unlock_irq(q->queue_lock);
+}
+
+/**
+ * blk_throtl_dispatch_work_fn - work function for throtl_data->dispatch_work
+ * @work: work item being executed
+ *
+ * This function is queued for execution when bio's reach the bio_lists[]
+ * of throtl_data->service_queue. Those bio's are ready and issued by this
+ * function.
+ */
+static void blk_throtl_dispatch_work_fn(struct work_struct *work)
+{
+ struct throtl_data *td = container_of(work, struct throtl_data,
+ dispatch_work);
+ struct throtl_service_queue *td_sq = &td->service_queue;
+ struct request_queue *q = td->queue;
+ struct bio_list bio_list_on_stack;
+ struct bio *bio;
+ struct blk_plug plug;
+ int rw;
+
+ bio_list_init(&bio_list_on_stack);
+
+ spin_lock_irq(q->queue_lock);
+ for (rw = READ; rw <= WRITE; rw++)
+ while ((bio = throtl_pop_queued(&td_sq->queued[rw], NULL)))
+ bio_list_add(&bio_list_on_stack, bio);
+ spin_unlock_irq(q->queue_lock);
+
+ if (!bio_list_empty(&bio_list_on_stack)) {
+ blk_start_plug(&plug);
+ while((bio = bio_list_pop(&bio_list_on_stack)))
+ generic_make_request(bio);
+ blk_finish_plug(&plug);
+ }
+}
+
+static u64 tg_prfill_conf_u64(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off)
+{
+ struct throtl_grp *tg = pd_to_tg(pd);
+ u64 v = *(u64 *)((void *)tg + off);
+
+ if (v == U64_MAX)
+ return 0;
+ return __blkg_prfill_u64(sf, pd, v);
+}
+
+static u64 tg_prfill_conf_uint(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off)
+{
+ struct throtl_grp *tg = pd_to_tg(pd);
+ unsigned int v = *(unsigned int *)((void *)tg + off);
+
+ if (v == UINT_MAX)
+ return 0;
+ return __blkg_prfill_u64(sf, pd, v);
+}
+
+static int tg_print_conf_u64(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_u64,
+ &blkcg_policy_throtl, seq_cft(sf)->private, false);
+ return 0;
+}
+
+static int tg_print_conf_uint(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_uint,
+ &blkcg_policy_throtl, seq_cft(sf)->private, false);
+ return 0;
+}
+
+static void tg_conf_updated(struct throtl_grp *tg, bool global)
+{
+ struct throtl_service_queue *sq = &tg->service_queue;
+ struct cgroup_subsys_state *pos_css;
+ struct blkcg_gq *blkg;
+
+ throtl_log(&tg->service_queue,
+ "limit change rbps=%llu wbps=%llu riops=%u wiops=%u",
+ tg_bps_limit(tg, READ), tg_bps_limit(tg, WRITE),
+ tg_iops_limit(tg, READ), tg_iops_limit(tg, WRITE));
+
+ /*
+ * Update has_rules[] flags for the updated tg's subtree. A tg is
+ * considered to have rules if either the tg itself or any of its
+ * ancestors has rules. This identifies groups without any
+ * restrictions in the whole hierarchy and allows them to bypass
+ * blk-throttle.
+ */
+ blkg_for_each_descendant_pre(blkg, pos_css,
+ global ? tg->td->queue->root_blkg : tg_to_blkg(tg)) {
+ struct throtl_grp *this_tg = blkg_to_tg(blkg);
+ struct throtl_grp *parent_tg;
+
+ tg_update_has_rules(this_tg);
+ /* ignore root/second level */
+ if (!cgroup_subsys_on_dfl(io_cgrp_subsys) || !blkg->parent ||
+ !blkg->parent->parent)
+ continue;
+ parent_tg = blkg_to_tg(blkg->parent);
+ /*
+ * make sure all children has lower idle time threshold and
+ * higher latency target
+ */
+ this_tg->idletime_threshold = min(this_tg->idletime_threshold,
+ parent_tg->idletime_threshold);
+ this_tg->latency_target = max(this_tg->latency_target,
+ parent_tg->latency_target);
+ }
+
+ /*
+ * We're already holding queue_lock and know @tg is valid. Let's
+ * apply the new config directly.
+ *
+ * Restart the slices for both READ and WRITES. It might happen
+ * that a group's limit are dropped suddenly and we don't want to
+ * account recently dispatched IO with new low rate.
+ */
+ throtl_start_new_slice(tg, 0);
+ throtl_start_new_slice(tg, 1);
+
+ if (tg->flags & THROTL_TG_PENDING) {
+ tg_update_disptime(tg);
+ throtl_schedule_next_dispatch(sq->parent_sq, true);
+ }
+}
+
+static ssize_t tg_set_conf(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off, bool is_u64)
+{
+ struct blkcg *blkcg = css_to_blkcg(of_css(of));
+ struct blkg_conf_ctx ctx;
+ struct throtl_grp *tg;
+ int ret;
+ u64 v;
+
+ ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx);
+ if (ret)
+ return ret;
+
+ ret = -EINVAL;
+ if (sscanf(ctx.body, "%llu", &v) != 1)
+ goto out_finish;
+ if (!v)
+ v = U64_MAX;
+
+ tg = blkg_to_tg(ctx.blkg);
+
+ if (is_u64)
+ *(u64 *)((void *)tg + of_cft(of)->private) = v;
+ else
+ *(unsigned int *)((void *)tg + of_cft(of)->private) = v;
+
+ tg_conf_updated(tg, false);
+ ret = 0;
+out_finish:
+ blkg_conf_finish(&ctx);
+ return ret ?: nbytes;
+}
+
+static ssize_t tg_set_conf_u64(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ return tg_set_conf(of, buf, nbytes, off, true);
+}
+
+static ssize_t tg_set_conf_uint(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ return tg_set_conf(of, buf, nbytes, off, false);
+}
+
+static struct cftype throtl_legacy_files[] = {
+ {
+ .name = "throttle.read_bps_device",
+ .private = offsetof(struct throtl_grp, bps[READ][LIMIT_MAX]),
+ .seq_show = tg_print_conf_u64,
+ .write = tg_set_conf_u64,
+ },
+ {
+ .name = "throttle.write_bps_device",
+ .private = offsetof(struct throtl_grp, bps[WRITE][LIMIT_MAX]),
+ .seq_show = tg_print_conf_u64,
+ .write = tg_set_conf_u64,
+ },
+ {
+ .name = "throttle.read_iops_device",
+ .private = offsetof(struct throtl_grp, iops[READ][LIMIT_MAX]),
+ .seq_show = tg_print_conf_uint,
+ .write = tg_set_conf_uint,
+ },
+ {
+ .name = "throttle.write_iops_device",
+ .private = offsetof(struct throtl_grp, iops[WRITE][LIMIT_MAX]),
+ .seq_show = tg_print_conf_uint,
+ .write = tg_set_conf_uint,
+ },
+ {
+ .name = "throttle.io_service_bytes",
+ .private = (unsigned long)&blkcg_policy_throtl,
+ .seq_show = blkg_print_stat_bytes,
+ },
+ {
+ .name = "throttle.io_serviced",
+ .private = (unsigned long)&blkcg_policy_throtl,
+ .seq_show = blkg_print_stat_ios,
+ },
+ { } /* terminate */
+};
+
+static u64 tg_prfill_limit(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off)
+{
+ struct throtl_grp *tg = pd_to_tg(pd);
+ const char *dname = blkg_dev_name(pd->blkg);
+ char bufs[4][21] = { "max", "max", "max", "max" };
+ u64 bps_dft;
+ unsigned int iops_dft;
+ char idle_time[26] = "";
+ char latency_time[26] = "";
+
+ if (!dname)
+ return 0;
+
+ if (off == LIMIT_LOW) {
+ bps_dft = 0;
+ iops_dft = 0;
+ } else {
+ bps_dft = U64_MAX;
+ iops_dft = UINT_MAX;
+ }
+
+ if (tg->bps_conf[READ][off] == bps_dft &&
+ tg->bps_conf[WRITE][off] == bps_dft &&
+ tg->iops_conf[READ][off] == iops_dft &&
+ tg->iops_conf[WRITE][off] == iops_dft &&
+ (off != LIMIT_LOW ||
+ (tg->idletime_threshold_conf == DFL_IDLE_THRESHOLD &&
+ tg->latency_target_conf == DFL_LATENCY_TARGET)))
+ return 0;
+
+ if (tg->bps_conf[READ][off] != U64_MAX)
+ snprintf(bufs[0], sizeof(bufs[0]), "%llu",
+ tg->bps_conf[READ][off]);
+ if (tg->bps_conf[WRITE][off] != U64_MAX)
+ snprintf(bufs[1], sizeof(bufs[1]), "%llu",
+ tg->bps_conf[WRITE][off]);
+ if (tg->iops_conf[READ][off] != UINT_MAX)
+ snprintf(bufs[2], sizeof(bufs[2]), "%u",
+ tg->iops_conf[READ][off]);
+ if (tg->iops_conf[WRITE][off] != UINT_MAX)
+ snprintf(bufs[3], sizeof(bufs[3]), "%u",
+ tg->iops_conf[WRITE][off]);
+ if (off == LIMIT_LOW) {
+ if (tg->idletime_threshold_conf == ULONG_MAX)
+ strcpy(idle_time, " idle=max");
+ else
+ snprintf(idle_time, sizeof(idle_time), " idle=%lu",
+ tg->idletime_threshold_conf);
+
+ if (tg->latency_target_conf == ULONG_MAX)
+ strcpy(latency_time, " latency=max");
+ else
+ snprintf(latency_time, sizeof(latency_time),
+ " latency=%lu", tg->latency_target_conf);
+ }
+
+ seq_printf(sf, "%s rbps=%s wbps=%s riops=%s wiops=%s%s%s\n",
+ dname, bufs[0], bufs[1], bufs[2], bufs[3], idle_time,
+ latency_time);
+ return 0;
+}
+
+static int tg_print_limit(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_limit,
+ &blkcg_policy_throtl, seq_cft(sf)->private, false);
+ return 0;
+}
+
+static ssize_t tg_set_limit(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct blkcg *blkcg = css_to_blkcg(of_css(of));
+ struct blkg_conf_ctx ctx;
+ struct throtl_grp *tg;
+ u64 v[4];
+ unsigned long idle_time;
+ unsigned long latency_time;
+ int ret;
+ int index = of_cft(of)->private;
+
+ ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx);
+ if (ret)
+ return ret;
+
+ tg = blkg_to_tg(ctx.blkg);
+
+ v[0] = tg->bps_conf[READ][index];
+ v[1] = tg->bps_conf[WRITE][index];
+ v[2] = tg->iops_conf[READ][index];
+ v[3] = tg->iops_conf[WRITE][index];
+
+ idle_time = tg->idletime_threshold_conf;
+ latency_time = tg->latency_target_conf;
+ while (true) {
+ char tok[27]; /* wiops=18446744073709551616 */
+ char *p;
+ u64 val = U64_MAX;
+ int len;
+
+ if (sscanf(ctx.body, "%26s%n", tok, &len) != 1)
+ break;
+ if (tok[0] == '\0')
+ break;
+ ctx.body += len;
+
+ ret = -EINVAL;
+ p = tok;
+ strsep(&p, "=");
+ if (!p || (sscanf(p, "%llu", &val) != 1 && strcmp(p, "max")))
+ goto out_finish;
+
+ ret = -ERANGE;
+ if (!val)
+ goto out_finish;
+
+ ret = -EINVAL;
+ if (!strcmp(tok, "rbps"))
+ v[0] = val;
+ else if (!strcmp(tok, "wbps"))
+ v[1] = val;
+ else if (!strcmp(tok, "riops"))
+ v[2] = min_t(u64, val, UINT_MAX);
+ else if (!strcmp(tok, "wiops"))
+ v[3] = min_t(u64, val, UINT_MAX);
+ else if (off == LIMIT_LOW && !strcmp(tok, "idle"))
+ idle_time = val;
+ else if (off == LIMIT_LOW && !strcmp(tok, "latency"))
+ latency_time = val;
+ else
+ goto out_finish;
+ }
+
+ tg->bps_conf[READ][index] = v[0];
+ tg->bps_conf[WRITE][index] = v[1];
+ tg->iops_conf[READ][index] = v[2];
+ tg->iops_conf[WRITE][index] = v[3];
+
+ if (index == LIMIT_MAX) {
+ tg->bps[READ][index] = v[0];
+ tg->bps[WRITE][index] = v[1];
+ tg->iops[READ][index] = v[2];
+ tg->iops[WRITE][index] = v[3];
+ }
+ tg->bps[READ][LIMIT_LOW] = min(tg->bps_conf[READ][LIMIT_LOW],
+ tg->bps_conf[READ][LIMIT_MAX]);
+ tg->bps[WRITE][LIMIT_LOW] = min(tg->bps_conf[WRITE][LIMIT_LOW],
+ tg->bps_conf[WRITE][LIMIT_MAX]);
+ tg->iops[READ][LIMIT_LOW] = min(tg->iops_conf[READ][LIMIT_LOW],
+ tg->iops_conf[READ][LIMIT_MAX]);
+ tg->iops[WRITE][LIMIT_LOW] = min(tg->iops_conf[WRITE][LIMIT_LOW],
+ tg->iops_conf[WRITE][LIMIT_MAX]);
+ tg->idletime_threshold_conf = idle_time;
+ tg->latency_target_conf = latency_time;
+
+ /* force user to configure all settings for low limit */
+ if (!(tg->bps[READ][LIMIT_LOW] || tg->iops[READ][LIMIT_LOW] ||
+ tg->bps[WRITE][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]) ||
+ tg->idletime_threshold_conf == DFL_IDLE_THRESHOLD ||
+ tg->latency_target_conf == DFL_LATENCY_TARGET) {
+ tg->bps[READ][LIMIT_LOW] = 0;
+ tg->bps[WRITE][LIMIT_LOW] = 0;
+ tg->iops[READ][LIMIT_LOW] = 0;
+ tg->iops[WRITE][LIMIT_LOW] = 0;
+ tg->idletime_threshold = DFL_IDLE_THRESHOLD;
+ tg->latency_target = DFL_LATENCY_TARGET;
+ } else if (index == LIMIT_LOW) {
+ tg->idletime_threshold = tg->idletime_threshold_conf;
+ tg->latency_target = tg->latency_target_conf;
+ }
+
+ blk_throtl_update_limit_valid(tg->td);
+ if (tg->td->limit_valid[LIMIT_LOW]) {
+ if (index == LIMIT_LOW)
+ tg->td->limit_index = LIMIT_LOW;
+ } else
+ tg->td->limit_index = LIMIT_MAX;
+ tg_conf_updated(tg, index == LIMIT_LOW &&
+ tg->td->limit_valid[LIMIT_LOW]);
+ ret = 0;
+out_finish:
+ blkg_conf_finish(&ctx);
+ return ret ?: nbytes;
+}
+
+static struct cftype throtl_files[] = {
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+ {
+ .name = "low",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = tg_print_limit,
+ .write = tg_set_limit,
+ .private = LIMIT_LOW,
+ },
+#endif
+ {
+ .name = "max",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = tg_print_limit,
+ .write = tg_set_limit,
+ .private = LIMIT_MAX,
+ },
+ { } /* terminate */
+};
+
+static void throtl_shutdown_wq(struct request_queue *q)
+{
+ struct throtl_data *td = q->td;
+
+ cancel_work_sync(&td->dispatch_work);
+}
+
+static struct blkcg_policy blkcg_policy_throtl = {
+ .dfl_cftypes = throtl_files,
+ .legacy_cftypes = throtl_legacy_files,
+
+ .pd_alloc_fn = throtl_pd_alloc,
+ .pd_init_fn = throtl_pd_init,
+ .pd_online_fn = throtl_pd_online,
+ .pd_offline_fn = throtl_pd_offline,
+ .pd_free_fn = throtl_pd_free,
+};
+
+static unsigned long __tg_last_low_overflow_time(struct throtl_grp *tg)
+{
+ unsigned long rtime = jiffies, wtime = jiffies;
+
+ if (tg->bps[READ][LIMIT_LOW] || tg->iops[READ][LIMIT_LOW])
+ rtime = tg->last_low_overflow_time[READ];
+ if (tg->bps[WRITE][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW])
+ wtime = tg->last_low_overflow_time[WRITE];
+ return min(rtime, wtime);
+}
+
+/* tg should not be an intermediate node */
+static unsigned long tg_last_low_overflow_time(struct throtl_grp *tg)
+{
+ struct throtl_service_queue *parent_sq;
+ struct throtl_grp *parent = tg;
+ unsigned long ret = __tg_last_low_overflow_time(tg);
+
+ while (true) {
+ parent_sq = parent->service_queue.parent_sq;
+ parent = sq_to_tg(parent_sq);
+ if (!parent)
+ break;
+
+ /*
+ * The parent doesn't have low limit, it always reaches low
+ * limit. Its overflow time is useless for children
+ */
+ if (!parent->bps[READ][LIMIT_LOW] &&
+ !parent->iops[READ][LIMIT_LOW] &&
+ !parent->bps[WRITE][LIMIT_LOW] &&
+ !parent->iops[WRITE][LIMIT_LOW])
+ continue;
+ if (time_after(__tg_last_low_overflow_time(parent), ret))
+ ret = __tg_last_low_overflow_time(parent);
+ }
+ return ret;
+}
+
+static bool throtl_tg_is_idle(struct throtl_grp *tg)
+{
+ /*
+ * cgroup is idle if:
+ * - single idle is too long, longer than a fixed value (in case user
+ * configure a too big threshold) or 4 times of idletime threshold
+ * - average think time is more than threshold
+ * - IO latency is largely below threshold
+ */
+ unsigned long time;
+ bool ret;
+
+ time = min_t(unsigned long, MAX_IDLE_TIME, 4 * tg->idletime_threshold);
+ ret = tg->latency_target == DFL_LATENCY_TARGET ||
+ tg->idletime_threshold == DFL_IDLE_THRESHOLD ||
+ (ktime_get_ns() >> 10) - tg->last_finish_time > time ||
+ tg->avg_idletime > tg->idletime_threshold ||
+ (tg->latency_target && tg->bio_cnt &&
+ tg->bad_bio_cnt * 5 < tg->bio_cnt);
+ throtl_log(&tg->service_queue,
+ "avg_idle=%ld, idle_threshold=%ld, bad_bio=%d, total_bio=%d, is_idle=%d, scale=%d",
+ tg->avg_idletime, tg->idletime_threshold, tg->bad_bio_cnt,
+ tg->bio_cnt, ret, tg->td->scale);
+ return ret;
+}
+
+static bool throtl_tg_can_upgrade(struct throtl_grp *tg)
+{
+ struct throtl_service_queue *sq = &tg->service_queue;
+ bool read_limit, write_limit;
+
+ /*
+ * if cgroup reaches low limit (if low limit is 0, the cgroup always
+ * reaches), it's ok to upgrade to next limit
+ */
+ read_limit = tg->bps[READ][LIMIT_LOW] || tg->iops[READ][LIMIT_LOW];
+ write_limit = tg->bps[WRITE][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW];
+ if (!read_limit && !write_limit)
+ return true;
+ if (read_limit && sq->nr_queued[READ] &&
+ (!write_limit || sq->nr_queued[WRITE]))
+ return true;
+ if (write_limit && sq->nr_queued[WRITE] &&
+ (!read_limit || sq->nr_queued[READ]))
+ return true;
+
+ if (time_after_eq(jiffies,
+ tg_last_low_overflow_time(tg) + tg->td->throtl_slice) &&
+ throtl_tg_is_idle(tg))
+ return true;
+ return false;
+}
+
+static bool throtl_hierarchy_can_upgrade(struct throtl_grp *tg)
+{
+ while (true) {
+ if (throtl_tg_can_upgrade(tg))
+ return true;
+ tg = sq_to_tg(tg->service_queue.parent_sq);
+ if (!tg || !tg_to_blkg(tg)->parent)
+ return false;
+ }
+ return false;
+}
+
+static bool throtl_can_upgrade(struct throtl_data *td,
+ struct throtl_grp *this_tg)
+{
+ struct cgroup_subsys_state *pos_css;
+ struct blkcg_gq *blkg;
+
+ if (td->limit_index != LIMIT_LOW)
+ return false;
+
+ if (time_before(jiffies, td->low_downgrade_time + td->throtl_slice))
+ return false;
+
+ rcu_read_lock();
+ blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) {
+ struct throtl_grp *tg = blkg_to_tg(blkg);
+
+ if (tg == this_tg)
+ continue;
+ if (!list_empty(&tg_to_blkg(tg)->blkcg->css.children))
+ continue;
+ if (!throtl_hierarchy_can_upgrade(tg)) {
+ rcu_read_unlock();
+ return false;
+ }
+ }
+ rcu_read_unlock();
+ return true;
+}
+
+static void throtl_upgrade_check(struct throtl_grp *tg)
+{
+ unsigned long now = jiffies;
+
+ if (tg->td->limit_index != LIMIT_LOW)
+ return;
+
+ if (time_after(tg->last_check_time + tg->td->throtl_slice, now))
+ return;
+
+ tg->last_check_time = now;
+
+ if (!time_after_eq(now,
+ __tg_last_low_overflow_time(tg) + tg->td->throtl_slice))
+ return;
+
+ if (throtl_can_upgrade(tg->td, NULL))
+ throtl_upgrade_state(tg->td);
+}
+
+static void throtl_upgrade_state(struct throtl_data *td)
+{
+ struct cgroup_subsys_state *pos_css;
+ struct blkcg_gq *blkg;
+
+ throtl_log(&td->service_queue, "upgrade to max");
+ td->limit_index = LIMIT_MAX;
+ td->low_upgrade_time = jiffies;
+ td->scale = 0;
+ rcu_read_lock();
+ blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) {
+ struct throtl_grp *tg = blkg_to_tg(blkg);
+ struct throtl_service_queue *sq = &tg->service_queue;
+
+ tg->disptime = jiffies - 1;
+ throtl_select_dispatch(sq);
+ throtl_schedule_next_dispatch(sq, true);
+ }
+ rcu_read_unlock();
+ throtl_select_dispatch(&td->service_queue);
+ throtl_schedule_next_dispatch(&td->service_queue, true);
+ queue_work(kthrotld_workqueue, &td->dispatch_work);
+}
+
+static void throtl_downgrade_state(struct throtl_data *td, int new)
+{
+ td->scale /= 2;
+
+ throtl_log(&td->service_queue, "downgrade, scale %d", td->scale);
+ if (td->scale) {
+ td->low_upgrade_time = jiffies - td->scale * td->throtl_slice;
+ return;
+ }
+
+ td->limit_index = new;
+ td->low_downgrade_time = jiffies;
+}
+
+static bool throtl_tg_can_downgrade(struct throtl_grp *tg)
+{
+ struct throtl_data *td = tg->td;
+ unsigned long now = jiffies;
+
+ /*
+ * If cgroup is below low limit, consider downgrade and throttle other
+ * cgroups
+ */
+ if (time_after_eq(now, td->low_upgrade_time + td->throtl_slice) &&
+ time_after_eq(now, tg_last_low_overflow_time(tg) +
+ td->throtl_slice) &&
+ (!throtl_tg_is_idle(tg) ||
+ !list_empty(&tg_to_blkg(tg)->blkcg->css.children)))
+ return true;
+ return false;
+}
+
+static bool throtl_hierarchy_can_downgrade(struct throtl_grp *tg)
+{
+ while (true) {
+ if (!throtl_tg_can_downgrade(tg))
+ return false;
+ tg = sq_to_tg(tg->service_queue.parent_sq);
+ if (!tg || !tg_to_blkg(tg)->parent)
+ break;
+ }
+ return true;
+}
+
+static void throtl_downgrade_check(struct throtl_grp *tg)
+{
+ uint64_t bps;
+ unsigned int iops;
+ unsigned long elapsed_time;
+ unsigned long now = jiffies;
+
+ if (tg->td->limit_index != LIMIT_MAX ||
+ !tg->td->limit_valid[LIMIT_LOW])
+ return;
+ if (!list_empty(&tg_to_blkg(tg)->blkcg->css.children))
+ return;
+ if (time_after(tg->last_check_time + tg->td->throtl_slice, now))
+ return;
+
+ elapsed_time = now - tg->last_check_time;
+ tg->last_check_time = now;
+
+ if (time_before(now, tg_last_low_overflow_time(tg) +
+ tg->td->throtl_slice))
+ return;
+
+ if (tg->bps[READ][LIMIT_LOW]) {
+ bps = tg->last_bytes_disp[READ] * HZ;
+ do_div(bps, elapsed_time);
+ if (bps >= tg->bps[READ][LIMIT_LOW])
+ tg->last_low_overflow_time[READ] = now;
+ }
+
+ if (tg->bps[WRITE][LIMIT_LOW]) {
+ bps = tg->last_bytes_disp[WRITE] * HZ;
+ do_div(bps, elapsed_time);
+ if (bps >= tg->bps[WRITE][LIMIT_LOW])
+ tg->last_low_overflow_time[WRITE] = now;
+ }
+
+ if (tg->iops[READ][LIMIT_LOW]) {
+ iops = tg->last_io_disp[READ] * HZ / elapsed_time;
+ if (iops >= tg->iops[READ][LIMIT_LOW])
+ tg->last_low_overflow_time[READ] = now;
+ }
+
+ if (tg->iops[WRITE][LIMIT_LOW]) {
+ iops = tg->last_io_disp[WRITE] * HZ / elapsed_time;
+ if (iops >= tg->iops[WRITE][LIMIT_LOW])
+ tg->last_low_overflow_time[WRITE] = now;
+ }
+
+ /*
+ * If cgroup is below low limit, consider downgrade and throttle other
+ * cgroups
+ */
+ if (throtl_hierarchy_can_downgrade(tg))
+ throtl_downgrade_state(tg->td, LIMIT_LOW);
+
+ tg->last_bytes_disp[READ] = 0;
+ tg->last_bytes_disp[WRITE] = 0;
+ tg->last_io_disp[READ] = 0;
+ tg->last_io_disp[WRITE] = 0;
+}
+
+static void blk_throtl_update_idletime(struct throtl_grp *tg)
+{
+ unsigned long now = ktime_get_ns() >> 10;
+ unsigned long last_finish_time = tg->last_finish_time;
+
+ if (now <= last_finish_time || last_finish_time == 0 ||
+ last_finish_time == tg->checked_last_finish_time)
+ return;
+
+ tg->avg_idletime = (tg->avg_idletime * 7 + now - last_finish_time) >> 3;
+ tg->checked_last_finish_time = last_finish_time;
+}
+
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+static void throtl_update_latency_buckets(struct throtl_data *td)
+{
+ struct avg_latency_bucket avg_latency[LATENCY_BUCKET_SIZE];
+ int i, cpu;
+ unsigned long last_latency = 0;
+ unsigned long latency;
+
+ if (!blk_queue_nonrot(td->queue))
+ return;
+ if (time_before(jiffies, td->last_calculate_time + HZ))
+ return;
+ td->last_calculate_time = jiffies;
+
+ memset(avg_latency, 0, sizeof(avg_latency));
+ for (i = 0; i < LATENCY_BUCKET_SIZE; i++) {
+ struct latency_bucket *tmp = &td->tmp_buckets[i];
+
+ for_each_possible_cpu(cpu) {
+ struct latency_bucket *bucket;
+
+ /* this isn't race free, but ok in practice */
+ bucket = per_cpu_ptr(td->latency_buckets, cpu);
+ tmp->total_latency += bucket[i].total_latency;
+ tmp->samples += bucket[i].samples;
+ bucket[i].total_latency = 0;
+ bucket[i].samples = 0;
+ }
+
+ if (tmp->samples >= 32) {
+ int samples = tmp->samples;
+
+ latency = tmp->total_latency;
+
+ tmp->total_latency = 0;
+ tmp->samples = 0;
+ latency /= samples;
+ if (latency == 0)
+ continue;
+ avg_latency[i].latency = latency;
+ }
+ }
+
+ for (i = 0; i < LATENCY_BUCKET_SIZE; i++) {
+ if (!avg_latency[i].latency) {
+ if (td->avg_buckets[i].latency < last_latency)
+ td->avg_buckets[i].latency = last_latency;
+ continue;
+ }
+
+ if (!td->avg_buckets[i].valid)
+ latency = avg_latency[i].latency;
+ else
+ latency = (td->avg_buckets[i].latency * 7 +
+ avg_latency[i].latency) >> 3;
+
+ td->avg_buckets[i].latency = max(latency, last_latency);
+ td->avg_buckets[i].valid = true;
+ last_latency = td->avg_buckets[i].latency;
+ }
+
+ for (i = 0; i < LATENCY_BUCKET_SIZE; i++)
+ throtl_log(&td->service_queue,
+ "Latency bucket %d: latency=%ld, valid=%d", i,
+ td->avg_buckets[i].latency, td->avg_buckets[i].valid);
+}
+#else
+static inline void throtl_update_latency_buckets(struct throtl_data *td)
+{
+}
+#endif
+
+static void blk_throtl_assoc_bio(struct throtl_grp *tg, struct bio *bio)
+{
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+ if (bio->bi_css)
+ bio->bi_cg_private = tg;
+ blk_stat_set_issue(&bio->bi_issue_stat, bio_sectors(bio));
+#endif
+}
+
+bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
+ struct bio *bio)
+{
+ struct throtl_qnode *qn = NULL;
+ struct throtl_grp *tg = blkg_to_tg(blkg ?: q->root_blkg);
+ struct throtl_service_queue *sq;
+ bool rw = bio_data_dir(bio);
+ bool throttled = false;
+ struct throtl_data *td = tg->td;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ /* see throtl_charge_bio() */
+ if (bio_flagged(bio, BIO_THROTTLED) || !tg->has_rules[rw])
+ goto out;
+
+ spin_lock_irq(q->queue_lock);
+
+ throtl_update_latency_buckets(td);
+
+ if (unlikely(blk_queue_bypass(q)))
+ goto out_unlock;
+
+ blk_throtl_assoc_bio(tg, bio);
+ blk_throtl_update_idletime(tg);
+
+ sq = &tg->service_queue;
+
+again:
+ while (true) {
+ if (tg->last_low_overflow_time[rw] == 0)
+ tg->last_low_overflow_time[rw] = jiffies;
+ throtl_downgrade_check(tg);
+ throtl_upgrade_check(tg);
+ /* throtl is FIFO - if bios are already queued, should queue */
+ if (sq->nr_queued[rw])
+ break;
+
+ /* if above limits, break to queue */
+ if (!tg_may_dispatch(tg, bio, NULL)) {
+ tg->last_low_overflow_time[rw] = jiffies;
+ if (throtl_can_upgrade(td, tg)) {
+ throtl_upgrade_state(td);
+ goto again;
+ }
+ break;
+ }
+
+ /* within limits, let's charge and dispatch directly */
+ throtl_charge_bio(tg, bio);
+
+ /*
+ * We need to trim slice even when bios are not being queued
+ * otherwise it might happen that a bio is not queued for
+ * a long time and slice keeps on extending and trim is not
+ * called for a long time. Now if limits are reduced suddenly
+ * we take into account all the IO dispatched so far at new
+ * low rate and * newly queued IO gets a really long dispatch
+ * time.
+ *
+ * So keep on trimming slice even if bio is not queued.
+ */
+ throtl_trim_slice(tg, rw);
+
+ /*
+ * @bio passed through this layer without being throttled.
+ * Climb up the ladder. If we''re already at the top, it
+ * can be executed directly.
+ */
+ qn = &tg->qnode_on_parent[rw];
+ sq = sq->parent_sq;
+ tg = sq_to_tg(sq);
+ if (!tg)
+ goto out_unlock;
+ }
+
+ /* out-of-limit, queue to @tg */
+ throtl_log(sq, "[%c] bio. bdisp=%llu sz=%u bps=%llu iodisp=%u iops=%u queued=%d/%d",
+ rw == READ ? 'R' : 'W',
+ tg->bytes_disp[rw], bio->bi_iter.bi_size,
+ tg_bps_limit(tg, rw),
+ tg->io_disp[rw], tg_iops_limit(tg, rw),
+ sq->nr_queued[READ], sq->nr_queued[WRITE]);
+
+ tg->last_low_overflow_time[rw] = jiffies;
+
+ td->nr_queued[rw]++;
+ throtl_add_bio_tg(bio, qn, tg);
+ throttled = true;
+
+ /*
+ * Update @tg's dispatch time and force schedule dispatch if @tg
+ * was empty before @bio. The forced scheduling isn't likely to
+ * cause undue delay as @bio is likely to be dispatched directly if
+ * its @tg's disptime is not in the future.
+ */
+ if (tg->flags & THROTL_TG_WAS_EMPTY) {
+ tg_update_disptime(tg);
+ throtl_schedule_next_dispatch(tg->service_queue.parent_sq, true);
+ }
+
+out_unlock:
+ spin_unlock_irq(q->queue_lock);
+out:
+ bio_set_flag(bio, BIO_THROTTLED);
+
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+ if (throttled || !td->track_bio_latency)
+ bio->bi_issue_stat.stat |= SKIP_LATENCY;
+#endif
+ return throttled;
+}
+
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+static void throtl_track_latency(struct throtl_data *td, sector_t size,
+ int op, unsigned long time)
+{
+ struct latency_bucket *latency;
+ int index;
+
+ if (!td || td->limit_index != LIMIT_LOW || op != REQ_OP_READ ||
+ !blk_queue_nonrot(td->queue))
+ return;
+
+ index = request_bucket_index(size);
+
+ latency = get_cpu_ptr(td->latency_buckets);
+ latency[index].total_latency += time;
+ latency[index].samples++;
+ put_cpu_ptr(td->latency_buckets);
+}
+
+void blk_throtl_stat_add(struct request *rq, u64 time_ns)
+{
+ struct request_queue *q = rq->q;
+ struct throtl_data *td = q->td;
+
+ throtl_track_latency(td, blk_stat_size(&rq->issue_stat),
+ req_op(rq), time_ns >> 10);
+}
+
+void blk_throtl_bio_endio(struct bio *bio)
+{
+ struct throtl_grp *tg;
+ u64 finish_time_ns;
+ unsigned long finish_time;
+ unsigned long start_time;
+ unsigned long lat;
+
+ tg = bio->bi_cg_private;
+ if (!tg)
+ return;
+ bio->bi_cg_private = NULL;
+
+ finish_time_ns = ktime_get_ns();
+ tg->last_finish_time = finish_time_ns >> 10;
+
+ start_time = blk_stat_time(&bio->bi_issue_stat) >> 10;
+ finish_time = __blk_stat_time(finish_time_ns) >> 10;
+ if (!start_time || finish_time <= start_time)
+ return;
+
+ lat = finish_time - start_time;
+ /* this is only for bio based driver */
+ if (!(bio->bi_issue_stat.stat & SKIP_LATENCY))
+ throtl_track_latency(tg->td, blk_stat_size(&bio->bi_issue_stat),
+ bio_op(bio), lat);
+
+ if (tg->latency_target && lat >= tg->td->filtered_latency) {
+ int bucket;
+ unsigned int threshold;
+
+ bucket = request_bucket_index(
+ blk_stat_size(&bio->bi_issue_stat));
+ threshold = tg->td->avg_buckets[bucket].latency +
+ tg->latency_target;
+ if (lat > threshold)
+ tg->bad_bio_cnt++;
+ /*
+ * Not race free, could get wrong count, which means cgroups
+ * will be throttled
+ */
+ tg->bio_cnt++;
+ }
+
+ if (time_after(jiffies, tg->bio_cnt_reset_time) || tg->bio_cnt > 1024) {
+ tg->bio_cnt_reset_time = tg->td->throtl_slice + jiffies;
+ tg->bio_cnt /= 2;
+ tg->bad_bio_cnt /= 2;
+ }
+}
+#endif
+
+/*
+ * Dispatch all bios from all children tg's queued on @parent_sq. On
+ * return, @parent_sq is guaranteed to not have any active children tg's
+ * and all bios from previously active tg's are on @parent_sq->bio_lists[].
+ */
+static void tg_drain_bios(struct throtl_service_queue *parent_sq)
+{
+ struct throtl_grp *tg;
+
+ while ((tg = throtl_rb_first(parent_sq))) {
+ struct throtl_service_queue *sq = &tg->service_queue;
+ struct bio *bio;
+
+ throtl_dequeue_tg(tg);
+
+ while ((bio = throtl_peek_queued(&sq->queued[READ])))
+ tg_dispatch_one_bio(tg, bio_data_dir(bio));
+ while ((bio = throtl_peek_queued(&sq->queued[WRITE])))
+ tg_dispatch_one_bio(tg, bio_data_dir(bio));
+ }
+}
+
+/**
+ * blk_throtl_drain - drain throttled bios
+ * @q: request_queue to drain throttled bios for
+ *
+ * Dispatch all currently throttled bios on @q through ->make_request_fn().
+ */
+void blk_throtl_drain(struct request_queue *q)
+ __releases(q->queue_lock) __acquires(q->queue_lock)
+{
+ struct throtl_data *td = q->td;
+ struct blkcg_gq *blkg;
+ struct cgroup_subsys_state *pos_css;
+ struct bio *bio;
+ int rw;
+
+ queue_lockdep_assert_held(q);
+ rcu_read_lock();
+
+ /*
+ * Drain each tg while doing post-order walk on the blkg tree, so
+ * that all bios are propagated to td->service_queue. It'd be
+ * better to walk service_queue tree directly but blkg walk is
+ * easier.
+ */
+ blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg)
+ tg_drain_bios(&blkg_to_tg(blkg)->service_queue);
+
+ /* finally, transfer bios from top-level tg's into the td */
+ tg_drain_bios(&td->service_queue);
+
+ rcu_read_unlock();
+ spin_unlock_irq(q->queue_lock);
+
+ /* all bios now should be in td->service_queue, issue them */
+ for (rw = READ; rw <= WRITE; rw++)
+ while ((bio = throtl_pop_queued(&td->service_queue.queued[rw],
+ NULL)))
+ generic_make_request(bio);
+
+ spin_lock_irq(q->queue_lock);
+}
+
+int blk_throtl_init(struct request_queue *q)
+{
+ struct throtl_data *td;
+ int ret;
+
+ td = kzalloc_node(sizeof(*td), GFP_KERNEL, q->node);
+ if (!td)
+ return -ENOMEM;
+ td->latency_buckets = __alloc_percpu(sizeof(struct latency_bucket) *
+ LATENCY_BUCKET_SIZE, __alignof__(u64));
+ if (!td->latency_buckets) {
+ kfree(td);
+ return -ENOMEM;
+ }
+
+ INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn);
+ throtl_service_queue_init(&td->service_queue);
+
+ q->td = td;
+ td->queue = q;
+
+ td->limit_valid[LIMIT_MAX] = true;
+ td->limit_index = LIMIT_MAX;
+ td->low_upgrade_time = jiffies;
+ td->low_downgrade_time = jiffies;
+
+ /* activate policy */
+ ret = blkcg_activate_policy(q, &blkcg_policy_throtl);
+ if (ret) {
+ free_percpu(td->latency_buckets);
+ kfree(td);
+ }
+ return ret;
+}
+
+void blk_throtl_exit(struct request_queue *q)
+{
+ BUG_ON(!q->td);
+ throtl_shutdown_wq(q);
+ blkcg_deactivate_policy(q, &blkcg_policy_throtl);
+ free_percpu(q->td->latency_buckets);
+ kfree(q->td);
+}
+
+void blk_throtl_register_queue(struct request_queue *q)
+{
+ struct throtl_data *td;
+ int i;
+
+ td = q->td;
+ BUG_ON(!td);
+
+ if (blk_queue_nonrot(q)) {
+ td->throtl_slice = DFL_THROTL_SLICE_SSD;
+ td->filtered_latency = LATENCY_FILTERED_SSD;
+ } else {
+ td->throtl_slice = DFL_THROTL_SLICE_HD;
+ td->filtered_latency = LATENCY_FILTERED_HD;
+ for (i = 0; i < LATENCY_BUCKET_SIZE; i++)
+ td->avg_buckets[i].latency = DFL_HD_BASELINE_LATENCY;
+ }
+#ifndef CONFIG_BLK_DEV_THROTTLING_LOW
+ /* if no low limit, use previous default */
+ td->throtl_slice = DFL_THROTL_SLICE_HD;
+#endif
+
+ td->track_bio_latency = !q->mq_ops && !q->request_fn;
+ if (!td->track_bio_latency)
+ blk_stat_enable_accounting(q);
+}
+
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page)
+{
+ if (!q->td)
+ return -EINVAL;
+ return sprintf(page, "%u\n", jiffies_to_msecs(q->td->throtl_slice));
+}
+
+ssize_t blk_throtl_sample_time_store(struct request_queue *q,
+ const char *page, size_t count)
+{
+ unsigned long v;
+ unsigned long t;
+
+ if (!q->td)
+ return -EINVAL;
+ if (kstrtoul(page, 10, &v))
+ return -EINVAL;
+ t = msecs_to_jiffies(v);
+ if (t == 0 || t > MAX_THROTL_SLICE)
+ return -EINVAL;
+ q->td->throtl_slice = t;
+ return count;
+}
+#endif
+
+static int __init throtl_init(void)
+{
+ kthrotld_workqueue = alloc_workqueue("kthrotld", WQ_MEM_RECLAIM, 0);
+ if (!kthrotld_workqueue)
+ panic("Failed to create kthrotld\n");
+
+ return blkcg_policy_register(&blkcg_policy_throtl);
+}
+
+module_init(throtl_init);
diff --git a/src/kernel/linux/v4.14/block/blk-timeout.c b/src/kernel/linux/v4.14/block/blk-timeout.c
new file mode 100644
index 0000000..6427be7
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-timeout.c
@@ -0,0 +1,242 @@
+/*
+ * Functions related to generic timeout handling of requests.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/fault-inject.h>
+
+#include "blk.h"
+#include "blk-mq.h"
+
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+
+static DECLARE_FAULT_ATTR(fail_io_timeout);
+
+static int __init setup_fail_io_timeout(char *str)
+{
+ return setup_fault_attr(&fail_io_timeout, str);
+}
+__setup("fail_io_timeout=", setup_fail_io_timeout);
+
+int blk_should_fake_timeout(struct request_queue *q)
+{
+ if (!test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags))
+ return 0;
+
+ return should_fail(&fail_io_timeout, 1);
+}
+
+static int __init fail_io_timeout_debugfs(void)
+{
+ struct dentry *dir = fault_create_debugfs_attr("fail_io_timeout",
+ NULL, &fail_io_timeout);
+
+ return PTR_ERR_OR_ZERO(dir);
+}
+
+late_initcall(fail_io_timeout_debugfs);
+
+ssize_t part_timeout_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ int set = test_bit(QUEUE_FLAG_FAIL_IO, &disk->queue->queue_flags);
+
+ return sprintf(buf, "%d\n", set != 0);
+}
+
+ssize_t part_timeout_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ int val;
+
+ if (count) {
+ struct request_queue *q = disk->queue;
+ char *p = (char *) buf;
+
+ val = simple_strtoul(p, &p, 10);
+ spin_lock_irq(q->queue_lock);
+ if (val)
+ queue_flag_set(QUEUE_FLAG_FAIL_IO, q);
+ else
+ queue_flag_clear(QUEUE_FLAG_FAIL_IO, q);
+ spin_unlock_irq(q->queue_lock);
+ }
+
+ return count;
+}
+
+#endif /* CONFIG_FAIL_IO_TIMEOUT */
+
+/*
+ * blk_delete_timer - Delete/cancel timer for a given function.
+ * @req: request that we are canceling timer for
+ *
+ */
+void blk_delete_timer(struct request *req)
+{
+ list_del_init(&req->timeout_list);
+}
+
+static void blk_rq_timed_out(struct request *req)
+{
+ struct request_queue *q = req->q;
+ enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
+
+ if (q->rq_timed_out_fn)
+ ret = q->rq_timed_out_fn(req);
+ switch (ret) {
+ case BLK_EH_HANDLED:
+ __blk_complete_request(req);
+ break;
+ case BLK_EH_RESET_TIMER:
+ blk_add_timer(req);
+ blk_clear_rq_complete(req);
+ break;
+ case BLK_EH_NOT_HANDLED:
+ /*
+ * LLD handles this for now but in the future
+ * we can send a request msg to abort the command
+ * and we can move more of the generic scsi eh code to
+ * the blk layer.
+ */
+ break;
+ default:
+ printk(KERN_ERR "block: bad eh return: %d\n", ret);
+ break;
+ }
+}
+
+static void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
+ unsigned int *next_set)
+{
+ if (time_after_eq(jiffies, rq->deadline)) {
+ list_del_init(&rq->timeout_list);
+
+ /*
+ * Check if we raced with end io completion
+ */
+ if (!blk_mark_rq_complete(rq))
+ blk_rq_timed_out(rq);
+ } else if (!*next_set || time_after(*next_timeout, rq->deadline)) {
+ *next_timeout = rq->deadline;
+ *next_set = 1;
+ }
+}
+
+void blk_timeout_work(struct work_struct *work)
+{
+ struct request_queue *q =
+ container_of(work, struct request_queue, timeout_work);
+ unsigned long flags, next = 0;
+ struct request *rq, *tmp;
+ int next_set = 0;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+
+ list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list)
+ blk_rq_check_expired(rq, &next, &next_set);
+
+ if (next_set)
+ mod_timer(&q->timeout, round_jiffies_up(next));
+
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+
+/**
+ * blk_abort_request -- Request request recovery for the specified command
+ * @req: pointer to the request of interest
+ *
+ * This function requests that the block layer start recovery for the
+ * request by deleting the timer and calling the q's timeout function.
+ * LLDDs who implement their own error recovery MAY ignore the timeout
+ * event if they generated blk_abort_req. Must hold queue lock.
+ */
+void blk_abort_request(struct request *req)
+{
+ if (blk_mark_rq_complete(req))
+ return;
+
+ if (req->q->mq_ops) {
+ blk_mq_rq_timed_out(req, false);
+ } else {
+ blk_delete_timer(req);
+ blk_rq_timed_out(req);
+ }
+}
+EXPORT_SYMBOL_GPL(blk_abort_request);
+
+unsigned long blk_rq_timeout(unsigned long timeout)
+{
+ unsigned long maxt;
+
+ maxt = round_jiffies_up(jiffies + BLK_MAX_TIMEOUT);
+ if (time_after(timeout, maxt))
+ timeout = maxt;
+
+ return timeout;
+}
+
+/**
+ * blk_add_timer - Start timeout timer for a single request
+ * @req: request that is about to start running.
+ *
+ * Notes:
+ * Each request has its own timer, and as it is added to the queue, we
+ * set up the timer. When the request completes, we cancel the timer.
+ */
+void blk_add_timer(struct request *req)
+{
+ struct request_queue *q = req->q;
+ unsigned long expiry;
+
+ if (!q->mq_ops)
+ lockdep_assert_held(q->queue_lock);
+
+ /* blk-mq has its own handler, so we don't need ->rq_timed_out_fn */
+ if (!q->mq_ops && !q->rq_timed_out_fn)
+ return;
+
+ BUG_ON(!list_empty(&req->timeout_list));
+
+ /*
+ * Some LLDs, like scsi, peek at the timeout to prevent a
+ * command from being retried forever.
+ */
+ if (!req->timeout)
+ req->timeout = q->rq_timeout;
+
+ req->deadline = jiffies + req->timeout;
+
+ /*
+ * Only the non-mq case needs to add the request to a protected list.
+ * For the mq case we simply scan the tag map.
+ */
+ if (!q->mq_ops)
+ list_add_tail(&req->timeout_list, &req->q->timeout_list);
+
+ /*
+ * If the timer isn't already pending or this timeout is earlier
+ * than an existing one, modify the timer. Round up to next nearest
+ * second.
+ */
+ expiry = blk_rq_timeout(round_jiffies_up(req->deadline));
+
+ if (!timer_pending(&q->timeout) ||
+ time_before(expiry, q->timeout.expires)) {
+ unsigned long diff = q->timeout.expires - expiry;
+
+ /*
+ * Due to added timer slack to group timers, the timer
+ * will often be a little in front of what we asked for.
+ * So apply some tolerance here too, otherwise we keep
+ * modifying the timer because expires for value X
+ * will be X + something.
+ */
+ if (!timer_pending(&q->timeout) || (diff >= HZ / 2))
+ mod_timer(&q->timeout, expiry);
+ }
+
+}
diff --git a/src/kernel/linux/v4.14/block/blk-wbt.c b/src/kernel/linux/v4.14/block/blk-wbt.c
new file mode 100644
index 0000000..5c10551
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-wbt.c
@@ -0,0 +1,766 @@
+/*
+ * buffered writeback throttling. loosely based on CoDel. We can't drop
+ * packets for IO scheduling, so the logic is something like this:
+ *
+ * - Monitor latencies in a defined window of time.
+ * - If the minimum latency in the above window exceeds some target, increment
+ * scaling step and scale down queue depth by a factor of 2x. The monitoring
+ * window is then shrunk to 100 / sqrt(scaling step + 1).
+ * - For any window where we don't have solid data on what the latencies
+ * look like, retain status quo.
+ * - If latencies look good, decrement scaling step.
+ * - If we're only doing writes, allow the scaling step to go negative. This
+ * will temporarily boost write performance, snapping back to a stable
+ * scaling step of 0 if reads show up or the heavy writers finish. Unlike
+ * positive scaling steps where we shrink the monitoring window, a negative
+ * scaling step retains the default step==0 window size.
+ *
+ * Copyright (C) 2016 Jens Axboe
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/blk_types.h>
+#include <linux/slab.h>
+#include <linux/backing-dev.h>
+#include <linux/swap.h>
+
+#include "blk-wbt.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/wbt.h>
+
+enum {
+ /*
+ * Default setting, we'll scale up (to 75% of QD max) or down (min 1)
+ * from here depending on device stats
+ */
+ RWB_DEF_DEPTH = 16,
+
+ /*
+ * 100msec window
+ */
+ RWB_WINDOW_NSEC = 100 * 1000 * 1000ULL,
+
+ /*
+ * Disregard stats, if we don't meet this minimum
+ */
+ RWB_MIN_WRITE_SAMPLES = 3,
+
+ /*
+ * If we have this number of consecutive windows with not enough
+ * information to scale up or down, scale up.
+ */
+ RWB_UNKNOWN_BUMP = 5,
+};
+
+static inline bool rwb_enabled(struct rq_wb *rwb)
+{
+ return rwb && rwb->wb_normal != 0;
+}
+
+/*
+ * Increment 'v', if 'v' is below 'below'. Returns true if we succeeded,
+ * false if 'v' + 1 would be bigger than 'below'.
+ */
+static bool atomic_inc_below(atomic_t *v, int below)
+{
+ int cur = atomic_read(v);
+
+ for (;;) {
+ int old;
+
+ if (cur >= below)
+ return false;
+ old = atomic_cmpxchg(v, cur, cur + 1);
+ if (old == cur)
+ break;
+ cur = old;
+ }
+
+ return true;
+}
+
+static void wb_timestamp(struct rq_wb *rwb, unsigned long *var)
+{
+ if (rwb_enabled(rwb)) {
+ const unsigned long cur = jiffies;
+
+ if (cur != *var)
+ *var = cur;
+ }
+}
+
+/*
+ * If a task was rate throttled in balance_dirty_pages() within the last
+ * second or so, use that to indicate a higher cleaning rate.
+ */
+static bool wb_recent_wait(struct rq_wb *rwb)
+{
+ struct bdi_writeback *wb = &rwb->queue->backing_dev_info->wb;
+
+ return time_before(jiffies, wb->dirty_sleep + HZ);
+}
+
+static inline struct rq_wait *get_rq_wait(struct rq_wb *rwb, bool is_kswapd)
+{
+ return &rwb->rq_wait[is_kswapd];
+}
+
+static void rwb_wake_all(struct rq_wb *rwb)
+{
+ int i;
+
+ for (i = 0; i < WBT_NUM_RWQ; i++) {
+ struct rq_wait *rqw = &rwb->rq_wait[i];
+
+ if (waitqueue_active(&rqw->wait))
+ wake_up_all(&rqw->wait);
+ }
+}
+
+void __wbt_done(struct rq_wb *rwb, enum wbt_flags wb_acct)
+{
+ struct rq_wait *rqw;
+ int inflight, limit;
+
+ if (!(wb_acct & WBT_TRACKED))
+ return;
+
+ rqw = get_rq_wait(rwb, wb_acct & WBT_KSWAPD);
+ inflight = atomic_dec_return(&rqw->inflight);
+
+ /*
+ * wbt got disabled with IO in flight. Wake up any potential
+ * waiters, we don't have to do more than that.
+ */
+ if (unlikely(!rwb_enabled(rwb))) {
+ rwb_wake_all(rwb);
+ return;
+ }
+
+ /*
+ * If the device does write back caching, drop further down
+ * before we wake people up.
+ */
+ if (rwb->wc && !wb_recent_wait(rwb))
+ limit = 0;
+ else
+ limit = rwb->wb_normal;
+
+ /*
+ * Don't wake anyone up if we are above the normal limit.
+ */
+ if (inflight && inflight >= limit)
+ return;
+
+ if (waitqueue_active(&rqw->wait)) {
+ int diff = limit - inflight;
+
+ if (!inflight || diff >= rwb->wb_background / 2)
+ wake_up_all(&rqw->wait);
+ }
+}
+
+/*
+ * Called on completion of a request. Note that it's also called when
+ * a request is merged, when the request gets freed.
+ */
+void wbt_done(struct rq_wb *rwb, struct blk_issue_stat *stat)
+{
+ if (!rwb)
+ return;
+
+ if (!wbt_is_tracked(stat)) {
+ if (rwb->sync_cookie == stat) {
+ rwb->sync_issue = 0;
+ rwb->sync_cookie = NULL;
+ }
+
+ if (wbt_is_read(stat))
+ wb_timestamp(rwb, &rwb->last_comp);
+ wbt_clear_state(stat);
+ } else {
+ WARN_ON_ONCE(stat == rwb->sync_cookie);
+ __wbt_done(rwb, wbt_stat_to_mask(stat));
+ wbt_clear_state(stat);
+ }
+}
+
+/*
+ * Return true, if we can't increase the depth further by scaling
+ */
+static bool calc_wb_limits(struct rq_wb *rwb)
+{
+ unsigned int depth;
+ bool ret = false;
+
+ if (!rwb->min_lat_nsec) {
+ rwb->wb_max = rwb->wb_normal = rwb->wb_background = 0;
+ return false;
+ }
+
+ /*
+ * For QD=1 devices, this is a special case. It's important for those
+ * to have one request ready when one completes, so force a depth of
+ * 2 for those devices. On the backend, it'll be a depth of 1 anyway,
+ * since the device can't have more than that in flight. If we're
+ * scaling down, then keep a setting of 1/1/1.
+ */
+ if (rwb->queue_depth == 1) {
+ if (rwb->scale_step > 0)
+ rwb->wb_max = rwb->wb_normal = 1;
+ else {
+ rwb->wb_max = rwb->wb_normal = 2;
+ ret = true;
+ }
+ rwb->wb_background = 1;
+ } else {
+ /*
+ * scale_step == 0 is our default state. If we have suffered
+ * latency spikes, step will be > 0, and we shrink the
+ * allowed write depths. If step is < 0, we're only doing
+ * writes, and we allow a temporarily higher depth to
+ * increase performance.
+ */
+ depth = min_t(unsigned int, RWB_DEF_DEPTH, rwb->queue_depth);
+ if (rwb->scale_step > 0)
+ depth = 1 + ((depth - 1) >> min(31, rwb->scale_step));
+ else if (rwb->scale_step < 0) {
+ unsigned int maxd = 3 * rwb->queue_depth / 4;
+
+ depth = 1 + ((depth - 1) << -rwb->scale_step);
+ if (depth > maxd) {
+ depth = maxd;
+ ret = true;
+ }
+ }
+
+ /*
+ * Set our max/normal/bg queue depths based on how far
+ * we have scaled down (->scale_step).
+ */
+ rwb->wb_max = depth;
+ rwb->wb_normal = (rwb->wb_max + 1) / 2;
+ rwb->wb_background = (rwb->wb_max + 3) / 4;
+ }
+
+ return ret;
+}
+
+static inline bool stat_sample_valid(struct blk_rq_stat *stat)
+{
+ /*
+ * We need at least one read sample, and a minimum of
+ * RWB_MIN_WRITE_SAMPLES. We require some write samples to know
+ * that it's writes impacting us, and not just some sole read on
+ * a device that is in a lower power state.
+ */
+ return (stat[READ].nr_samples >= 1 &&
+ stat[WRITE].nr_samples >= RWB_MIN_WRITE_SAMPLES);
+}
+
+static u64 rwb_sync_issue_lat(struct rq_wb *rwb)
+{
+ u64 now, issue = ACCESS_ONCE(rwb->sync_issue);
+
+ if (!issue || !rwb->sync_cookie)
+ return 0;
+
+ now = ktime_to_ns(ktime_get());
+ return now - issue;
+}
+
+enum {
+ LAT_OK = 1,
+ LAT_UNKNOWN,
+ LAT_UNKNOWN_WRITES,
+ LAT_EXCEEDED,
+};
+
+static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
+{
+ struct backing_dev_info *bdi = rwb->queue->backing_dev_info;
+ u64 thislat;
+
+ /*
+ * If our stored sync issue exceeds the window size, or it
+ * exceeds our min target AND we haven't logged any entries,
+ * flag the latency as exceeded. wbt works off completion latencies,
+ * but for a flooded device, a single sync IO can take a long time
+ * to complete after being issued. If this time exceeds our
+ * monitoring window AND we didn't see any other completions in that
+ * window, then count that sync IO as a violation of the latency.
+ */
+ thislat = rwb_sync_issue_lat(rwb);
+ if (thislat > rwb->cur_win_nsec ||
+ (thislat > rwb->min_lat_nsec && !stat[READ].nr_samples)) {
+ trace_wbt_lat(bdi, thislat);
+ return LAT_EXCEEDED;
+ }
+
+ /*
+ * No read/write mix, if stat isn't valid
+ */
+ if (!stat_sample_valid(stat)) {
+ /*
+ * If we had writes in this stat window and the window is
+ * current, we're only doing writes. If a task recently
+ * waited or still has writes in flights, consider us doing
+ * just writes as well.
+ */
+ if (stat[WRITE].nr_samples || wb_recent_wait(rwb) ||
+ wbt_inflight(rwb))
+ return LAT_UNKNOWN_WRITES;
+ return LAT_UNKNOWN;
+ }
+
+ /*
+ * If the 'min' latency exceeds our target, step down.
+ */
+ if (stat[READ].min > rwb->min_lat_nsec) {
+ trace_wbt_lat(bdi, stat[READ].min);
+ trace_wbt_stat(bdi, stat);
+ return LAT_EXCEEDED;
+ }
+
+ if (rwb->scale_step)
+ trace_wbt_stat(bdi, stat);
+
+ return LAT_OK;
+}
+
+static void rwb_trace_step(struct rq_wb *rwb, const char *msg)
+{
+ struct backing_dev_info *bdi = rwb->queue->backing_dev_info;
+
+ trace_wbt_step(bdi, msg, rwb->scale_step, rwb->cur_win_nsec,
+ rwb->wb_background, rwb->wb_normal, rwb->wb_max);
+}
+
+static void scale_up(struct rq_wb *rwb)
+{
+ /*
+ * Hit max in previous round, stop here
+ */
+ if (rwb->scaled_max)
+ return;
+
+ rwb->scale_step--;
+ rwb->unknown_cnt = 0;
+
+ rwb->scaled_max = calc_wb_limits(rwb);
+
+ rwb_wake_all(rwb);
+
+ rwb_trace_step(rwb, "step up");
+}
+
+/*
+ * Scale rwb down. If 'hard_throttle' is set, do it quicker, since we
+ * had a latency violation.
+ */
+static void scale_down(struct rq_wb *rwb, bool hard_throttle)
+{
+ /*
+ * Stop scaling down when we've hit the limit. This also prevents
+ * ->scale_step from going to crazy values, if the device can't
+ * keep up.
+ */
+ if (rwb->wb_max == 1)
+ return;
+
+ if (rwb->scale_step < 0 && hard_throttle)
+ rwb->scale_step = 0;
+ else
+ rwb->scale_step++;
+
+ rwb->scaled_max = false;
+ rwb->unknown_cnt = 0;
+ calc_wb_limits(rwb);
+ rwb_trace_step(rwb, "step down");
+}
+
+static void rwb_arm_timer(struct rq_wb *rwb)
+{
+ if (rwb->scale_step > 0) {
+ /*
+ * We should speed this up, using some variant of a fast
+ * integer inverse square root calculation. Since we only do
+ * this for every window expiration, it's not a huge deal,
+ * though.
+ */
+ rwb->cur_win_nsec = div_u64(rwb->win_nsec << 4,
+ int_sqrt((rwb->scale_step + 1) << 8));
+ } else {
+ /*
+ * For step < 0, we don't want to increase/decrease the
+ * window size.
+ */
+ rwb->cur_win_nsec = rwb->win_nsec;
+ }
+
+ blk_stat_activate_nsecs(rwb->cb, rwb->cur_win_nsec);
+}
+
+static void wb_timer_fn(struct blk_stat_callback *cb)
+{
+ struct rq_wb *rwb = cb->data;
+ unsigned int inflight = wbt_inflight(rwb);
+ int status;
+
+ status = latency_exceeded(rwb, cb->stat);
+
+ trace_wbt_timer(rwb->queue->backing_dev_info, status, rwb->scale_step,
+ inflight);
+
+ /*
+ * If we exceeded the latency target, step down. If we did not,
+ * step one level up. If we don't know enough to say either exceeded
+ * or ok, then don't do anything.
+ */
+ switch (status) {
+ case LAT_EXCEEDED:
+ scale_down(rwb, true);
+ break;
+ case LAT_OK:
+ scale_up(rwb);
+ break;
+ case LAT_UNKNOWN_WRITES:
+ /*
+ * We started a the center step, but don't have a valid
+ * read/write sample, but we do have writes going on.
+ * Allow step to go negative, to increase write perf.
+ */
+ scale_up(rwb);
+ break;
+ case LAT_UNKNOWN:
+ if (++rwb->unknown_cnt < RWB_UNKNOWN_BUMP)
+ break;
+ /*
+ * We get here when previously scaled reduced depth, and we
+ * currently don't have a valid read/write sample. For that
+ * case, slowly return to center state (step == 0).
+ */
+ if (rwb->scale_step > 0)
+ scale_up(rwb);
+ else if (rwb->scale_step < 0)
+ scale_down(rwb, false);
+ break;
+ default:
+ break;
+ }
+
+ /*
+ * Re-arm timer, if we have IO in flight
+ */
+ if (rwb->scale_step || inflight)
+ rwb_arm_timer(rwb);
+}
+
+void wbt_update_limits(struct rq_wb *rwb)
+{
+ rwb->scale_step = 0;
+ rwb->scaled_max = false;
+ calc_wb_limits(rwb);
+
+ rwb_wake_all(rwb);
+}
+
+static bool close_io(struct rq_wb *rwb)
+{
+ const unsigned long now = jiffies;
+
+ return time_before(now, rwb->last_issue + HZ / 10) ||
+ time_before(now, rwb->last_comp + HZ / 10);
+}
+
+#define REQ_HIPRIO (REQ_SYNC | REQ_META | REQ_PRIO)
+
+static inline unsigned int get_limit(struct rq_wb *rwb, unsigned long rw)
+{
+ unsigned int limit;
+
+ /*
+ * At this point we know it's a buffered write. If this is
+ * kswapd trying to free memory, or REQ_SYNC is set, set, then
+ * it's WB_SYNC_ALL writeback, and we'll use the max limit for
+ * that. If the write is marked as a background write, then use
+ * the idle limit, or go to normal if we haven't had competing
+ * IO for a bit.
+ */
+ if ((rw & REQ_HIPRIO) || wb_recent_wait(rwb) || current_is_kswapd())
+ limit = rwb->wb_max;
+ else if ((rw & REQ_BACKGROUND) || close_io(rwb)) {
+ /*
+ * If less than 100ms since we completed unrelated IO,
+ * limit us to half the depth for background writeback.
+ */
+ limit = rwb->wb_background;
+ } else
+ limit = rwb->wb_normal;
+
+ return limit;
+}
+
+static inline bool may_queue(struct rq_wb *rwb, struct rq_wait *rqw,
+ wait_queue_entry_t *wait, unsigned long rw)
+{
+ /*
+ * inc it here even if disabled, since we'll dec it at completion.
+ * this only happens if the task was sleeping in __wbt_wait(),
+ * and someone turned it off at the same time.
+ */
+ if (!rwb_enabled(rwb)) {
+ atomic_inc(&rqw->inflight);
+ return true;
+ }
+
+ /*
+ * If the waitqueue is already active and we are not the next
+ * in line to be woken up, wait for our turn.
+ */
+ if (waitqueue_active(&rqw->wait) &&
+ rqw->wait.head.next != &wait->entry)
+ return false;
+
+ return atomic_inc_below(&rqw->inflight, get_limit(rwb, rw));
+}
+
+/*
+ * Block if we will exceed our limit, or if we are currently waiting for
+ * the timer to kick off queuing again.
+ */
+static void __wbt_wait(struct rq_wb *rwb, unsigned long rw, spinlock_t *lock)
+ __releases(lock)
+ __acquires(lock)
+{
+ struct rq_wait *rqw = get_rq_wait(rwb, current_is_kswapd());
+ DEFINE_WAIT(wait);
+
+ if (may_queue(rwb, rqw, &wait, rw))
+ return;
+
+ do {
+ prepare_to_wait_exclusive(&rqw->wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+
+ if (may_queue(rwb, rqw, &wait, rw))
+ break;
+
+ if (lock) {
+ spin_unlock_irq(lock);
+ io_schedule();
+ spin_lock_irq(lock);
+ } else
+ io_schedule();
+ } while (1);
+
+ finish_wait(&rqw->wait, &wait);
+}
+
+static inline bool wbt_should_throttle(struct rq_wb *rwb, struct bio *bio)
+{
+ const int op = bio_op(bio);
+
+ /*
+ * If not a WRITE, do nothing
+ */
+ if (op != REQ_OP_WRITE)
+ return false;
+
+ /*
+ * Don't throttle WRITE_ODIRECT
+ */
+ if ((bio->bi_opf & (REQ_SYNC | REQ_IDLE)) == (REQ_SYNC | REQ_IDLE))
+ return false;
+
+ return true;
+}
+
+/*
+ * Returns true if the IO request should be accounted, false if not.
+ * May sleep, if we have exceeded the writeback limits. Caller can pass
+ * in an irq held spinlock, if it holds one when calling this function.
+ * If we do sleep, we'll release and re-grab it.
+ */
+enum wbt_flags wbt_wait(struct rq_wb *rwb, struct bio *bio, spinlock_t *lock)
+{
+ unsigned int ret = 0;
+
+ if (!rwb_enabled(rwb))
+ return 0;
+
+ if (bio_op(bio) == REQ_OP_READ)
+ ret = WBT_READ;
+
+ if (!wbt_should_throttle(rwb, bio)) {
+ if (ret & WBT_READ)
+ wb_timestamp(rwb, &rwb->last_issue);
+ return ret;
+ }
+
+ __wbt_wait(rwb, bio->bi_opf, lock);
+
+ if (!blk_stat_is_active(rwb->cb))
+ rwb_arm_timer(rwb);
+
+ if (current_is_kswapd())
+ ret |= WBT_KSWAPD;
+
+ return ret | WBT_TRACKED;
+}
+
+void wbt_issue(struct rq_wb *rwb, struct blk_issue_stat *stat)
+{
+ if (!rwb_enabled(rwb))
+ return;
+
+ /*
+ * Track sync issue, in case it takes a long time to complete. Allows
+ * us to react quicker, if a sync IO takes a long time to complete.
+ * Note that this is just a hint. 'stat' can go away when the
+ * request completes, so it's important we never dereference it. We
+ * only use the address to compare with, which is why we store the
+ * sync_issue time locally.
+ */
+ if (wbt_is_read(stat) && !rwb->sync_issue) {
+ rwb->sync_cookie = stat;
+ rwb->sync_issue = blk_stat_time(stat);
+ }
+}
+
+void wbt_requeue(struct rq_wb *rwb, struct blk_issue_stat *stat)
+{
+ if (!rwb_enabled(rwb))
+ return;
+ if (stat == rwb->sync_cookie) {
+ rwb->sync_issue = 0;
+ rwb->sync_cookie = NULL;
+ }
+}
+
+void wbt_set_queue_depth(struct rq_wb *rwb, unsigned int depth)
+{
+ if (rwb) {
+ rwb->queue_depth = depth;
+ wbt_update_limits(rwb);
+ }
+}
+
+void wbt_set_write_cache(struct rq_wb *rwb, bool write_cache_on)
+{
+ if (rwb)
+ rwb->wc = write_cache_on;
+}
+
+/*
+ * Disable wbt, if enabled by default.
+ */
+void wbt_disable_default(struct request_queue *q)
+{
+ struct rq_wb *rwb = q->rq_wb;
+
+ if (rwb && rwb->enable_state == WBT_STATE_ON_DEFAULT)
+ wbt_exit(q);
+}
+EXPORT_SYMBOL_GPL(wbt_disable_default);
+
+/*
+ * Enable wbt if defaults are configured that way
+ */
+void wbt_enable_default(struct request_queue *q)
+{
+ /* Throttling already enabled? */
+ if (q->rq_wb)
+ return;
+
+ /* Queue not registered? Maybe shutting down... */
+ if (!test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags))
+ return;
+
+ if ((q->mq_ops && IS_ENABLED(CONFIG_BLK_WBT_MQ)) ||
+ (q->request_fn && IS_ENABLED(CONFIG_BLK_WBT_SQ)))
+ wbt_init(q);
+}
+EXPORT_SYMBOL_GPL(wbt_enable_default);
+
+u64 wbt_default_latency_nsec(struct request_queue *q)
+{
+ /*
+ * We default to 2msec for non-rotational storage, and 75msec
+ * for rotational storage.
+ */
+ if (blk_queue_nonrot(q))
+ return 2000000ULL;
+ else
+ return 75000000ULL;
+}
+
+static int wbt_data_dir(const struct request *rq)
+{
+ const int op = req_op(rq);
+
+ if (op == REQ_OP_READ)
+ return READ;
+ else if (op == REQ_OP_WRITE || op == REQ_OP_FLUSH)
+ return WRITE;
+
+ /* don't account */
+ return -1;
+}
+
+int wbt_init(struct request_queue *q)
+{
+ struct rq_wb *rwb;
+ int i;
+
+ BUILD_BUG_ON(WBT_NR_BITS > BLK_STAT_RES_BITS);
+
+ rwb = kzalloc(sizeof(*rwb), GFP_KERNEL);
+ if (!rwb)
+ return -ENOMEM;
+
+ rwb->cb = blk_stat_alloc_callback(wb_timer_fn, wbt_data_dir, 2, rwb);
+ if (!rwb->cb) {
+ kfree(rwb);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < WBT_NUM_RWQ; i++) {
+ atomic_set(&rwb->rq_wait[i].inflight, 0);
+ init_waitqueue_head(&rwb->rq_wait[i].wait);
+ }
+
+ rwb->wc = 1;
+ rwb->queue_depth = RWB_DEF_DEPTH;
+ rwb->last_comp = rwb->last_issue = jiffies;
+ rwb->queue = q;
+ rwb->win_nsec = RWB_WINDOW_NSEC;
+ rwb->enable_state = WBT_STATE_ON_DEFAULT;
+ wbt_update_limits(rwb);
+
+ /*
+ * Assign rwb and add the stats callback.
+ */
+ q->rq_wb = rwb;
+ blk_stat_add_callback(q, rwb->cb);
+
+ rwb->min_lat_nsec = wbt_default_latency_nsec(q);
+
+ wbt_set_queue_depth(rwb, blk_queue_depth(q));
+ wbt_set_write_cache(rwb, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
+
+ return 0;
+}
+
+void wbt_exit(struct request_queue *q)
+{
+ struct rq_wb *rwb = q->rq_wb;
+
+ if (rwb) {
+ blk_stat_remove_callback(q, rwb->cb);
+ blk_stat_free_callback(rwb->cb);
+ q->rq_wb = NULL;
+ kfree(rwb);
+ }
+}
diff --git a/src/kernel/linux/v4.14/block/blk-wbt.h b/src/kernel/linux/v4.14/block/blk-wbt.h
new file mode 100644
index 0000000..a232c98
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-wbt.h
@@ -0,0 +1,176 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef WB_THROTTLE_H
+#define WB_THROTTLE_H
+
+#include <linux/kernel.h>
+#include <linux/atomic.h>
+#include <linux/wait.h>
+#include <linux/timer.h>
+#include <linux/ktime.h>
+
+#include "blk-stat.h"
+
+enum wbt_flags {
+ WBT_TRACKED = 1, /* write, tracked for throttling */
+ WBT_READ = 2, /* read */
+ WBT_KSWAPD = 4, /* write, from kswapd */
+
+ WBT_NR_BITS = 3, /* number of bits */
+};
+
+enum {
+ WBT_NUM_RWQ = 2,
+};
+
+/*
+ * Enable states. Either off, or on by default (done at init time),
+ * or on through manual setup in sysfs.
+ */
+enum {
+ WBT_STATE_ON_DEFAULT = 1,
+ WBT_STATE_ON_MANUAL = 2,
+};
+
+static inline void wbt_clear_state(struct blk_issue_stat *stat)
+{
+ stat->stat &= ~BLK_STAT_RES_MASK;
+}
+
+static inline enum wbt_flags wbt_stat_to_mask(struct blk_issue_stat *stat)
+{
+ return (stat->stat & BLK_STAT_RES_MASK) >> BLK_STAT_RES_SHIFT;
+}
+
+static inline void wbt_track(struct blk_issue_stat *stat, enum wbt_flags wb_acct)
+{
+ stat->stat |= ((u64) wb_acct) << BLK_STAT_RES_SHIFT;
+}
+
+static inline bool wbt_is_tracked(struct blk_issue_stat *stat)
+{
+ return (stat->stat >> BLK_STAT_RES_SHIFT) & WBT_TRACKED;
+}
+
+static inline bool wbt_is_read(struct blk_issue_stat *stat)
+{
+ return (stat->stat >> BLK_STAT_RES_SHIFT) & WBT_READ;
+}
+
+struct rq_wait {
+ wait_queue_head_t wait;
+ atomic_t inflight;
+};
+
+struct rq_wb {
+ /*
+ * Settings that govern how we throttle
+ */
+ unsigned int wb_background; /* background writeback */
+ unsigned int wb_normal; /* normal writeback */
+ unsigned int wb_max; /* max throughput writeback */
+ int scale_step;
+ bool scaled_max;
+
+ short enable_state; /* WBT_STATE_* */
+
+ /*
+ * Number of consecutive periods where we don't have enough
+ * information to make a firm scale up/down decision.
+ */
+ unsigned int unknown_cnt;
+
+ u64 win_nsec; /* default window size */
+ u64 cur_win_nsec; /* current window size */
+
+ struct blk_stat_callback *cb;
+
+ s64 sync_issue;
+ void *sync_cookie;
+
+ unsigned int wc;
+ unsigned int queue_depth;
+
+ unsigned long last_issue; /* last non-throttled issue */
+ unsigned long last_comp; /* last non-throttled comp */
+ unsigned long min_lat_nsec;
+ struct request_queue *queue;
+ struct rq_wait rq_wait[WBT_NUM_RWQ];
+};
+
+static inline unsigned int wbt_inflight(struct rq_wb *rwb)
+{
+ unsigned int i, ret = 0;
+
+ for (i = 0; i < WBT_NUM_RWQ; i++)
+ ret += atomic_read(&rwb->rq_wait[i].inflight);
+
+ return ret;
+}
+
+#ifdef CONFIG_BLK_WBT
+
+void __wbt_done(struct rq_wb *, enum wbt_flags);
+void wbt_done(struct rq_wb *, struct blk_issue_stat *);
+enum wbt_flags wbt_wait(struct rq_wb *, struct bio *, spinlock_t *);
+int wbt_init(struct request_queue *);
+void wbt_exit(struct request_queue *);
+void wbt_update_limits(struct rq_wb *);
+void wbt_requeue(struct rq_wb *, struct blk_issue_stat *);
+void wbt_issue(struct rq_wb *, struct blk_issue_stat *);
+void wbt_disable_default(struct request_queue *);
+void wbt_enable_default(struct request_queue *);
+
+void wbt_set_queue_depth(struct rq_wb *, unsigned int);
+void wbt_set_write_cache(struct rq_wb *, bool);
+
+u64 wbt_default_latency_nsec(struct request_queue *);
+
+#else
+
+static inline void __wbt_done(struct rq_wb *rwb, enum wbt_flags flags)
+{
+}
+static inline void wbt_done(struct rq_wb *rwb, struct blk_issue_stat *stat)
+{
+}
+static inline enum wbt_flags wbt_wait(struct rq_wb *rwb, struct bio *bio,
+ spinlock_t *lock)
+{
+ return 0;
+}
+static inline int wbt_init(struct request_queue *q)
+{
+ return -EINVAL;
+}
+static inline void wbt_exit(struct request_queue *q)
+{
+}
+static inline void wbt_update_limits(struct rq_wb *rwb)
+{
+}
+static inline void wbt_requeue(struct rq_wb *rwb, struct blk_issue_stat *stat)
+{
+}
+static inline void wbt_issue(struct rq_wb *rwb, struct blk_issue_stat *stat)
+{
+}
+static inline void wbt_disable_default(struct request_queue *q)
+{
+}
+static inline void wbt_enable_default(struct request_queue *q)
+{
+}
+static inline void wbt_set_queue_depth(struct rq_wb *rwb, unsigned int depth)
+{
+}
+static inline void wbt_set_write_cache(struct rq_wb *rwb, bool wc)
+{
+}
+static inline u64 wbt_default_latency_nsec(struct request_queue *q)
+{
+ return 0;
+}
+
+#endif /* CONFIG_BLK_WBT */
+
+#endif
diff --git a/src/kernel/linux/v4.14/block/blk-zoned.c b/src/kernel/linux/v4.14/block/blk-zoned.c
new file mode 100644
index 0000000..77fce6f
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk-zoned.c
@@ -0,0 +1,352 @@
+/*
+ * Zoned block device handling
+ *
+ * Copyright (c) 2015, Hannes Reinecke
+ * Copyright (c) 2015, SUSE Linux GmbH
+ *
+ * Copyright (c) 2016, Damien Le Moal
+ * Copyright (c) 2016, Western Digital
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rbtree.h>
+#include <linux/blkdev.h>
+
+static inline sector_t blk_zone_start(struct request_queue *q,
+ sector_t sector)
+{
+ sector_t zone_mask = blk_queue_zone_sectors(q) - 1;
+
+ return sector & ~zone_mask;
+}
+
+/*
+ * Check that a zone report belongs to the partition.
+ * If yes, fix its start sector and write pointer, copy it in the
+ * zone information array and return true. Return false otherwise.
+ */
+static bool blkdev_report_zone(struct block_device *bdev,
+ struct blk_zone *rep,
+ struct blk_zone *zone)
+{
+ sector_t offset = get_start_sect(bdev);
+
+ if (rep->start < offset)
+ return false;
+
+ rep->start -= offset;
+ if (rep->start + rep->len > bdev->bd_part->nr_sects)
+ return false;
+
+ if (rep->type == BLK_ZONE_TYPE_CONVENTIONAL)
+ rep->wp = rep->start + rep->len;
+ else
+ rep->wp -= offset;
+ memcpy(zone, rep, sizeof(struct blk_zone));
+
+ return true;
+}
+
+/**
+ * blkdev_report_zones - Get zones information
+ * @bdev: Target block device
+ * @sector: Sector from which to report zones
+ * @zones: Array of zone structures where to return the zones information
+ * @nr_zones: Number of zone structures in the zone array
+ * @gfp_mask: Memory allocation flags (for bio_alloc)
+ *
+ * Description:
+ * Get zone information starting from the zone containing @sector.
+ * The number of zone information reported may be less than the number
+ * requested by @nr_zones. The number of zones actually reported is
+ * returned in @nr_zones.
+ */
+int blkdev_report_zones(struct block_device *bdev,
+ sector_t sector,
+ struct blk_zone *zones,
+ unsigned int *nr_zones,
+ gfp_t gfp_mask)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+ struct blk_zone_report_hdr *hdr;
+ unsigned int nrz = *nr_zones;
+ struct page *page;
+ unsigned int nr_rep;
+ size_t rep_bytes;
+ unsigned int nr_pages;
+ struct bio *bio;
+ struct bio_vec *bv;
+ unsigned int i, n, nz;
+ unsigned int ofst;
+ void *addr;
+ int ret;
+
+ if (!q)
+ return -ENXIO;
+
+ if (!blk_queue_is_zoned(q))
+ return -EOPNOTSUPP;
+
+ if (!nrz)
+ return 0;
+
+ if (sector > bdev->bd_part->nr_sects) {
+ *nr_zones = 0;
+ return 0;
+ }
+
+ /*
+ * The zone report has a header. So make room for it in the
+ * payload. Also make sure that the report fits in a single BIO
+ * that will not be split down the stack.
+ */
+ rep_bytes = sizeof(struct blk_zone_report_hdr) +
+ sizeof(struct blk_zone) * nrz;
+ rep_bytes = (rep_bytes + PAGE_SIZE - 1) & PAGE_MASK;
+ if (rep_bytes > (queue_max_sectors(q) << 9))
+ rep_bytes = queue_max_sectors(q) << 9;
+
+ nr_pages = min_t(unsigned int, BIO_MAX_PAGES,
+ rep_bytes >> PAGE_SHIFT);
+ nr_pages = min_t(unsigned int, nr_pages,
+ queue_max_segments(q));
+
+ bio = bio_alloc(gfp_mask, nr_pages);
+ if (!bio)
+ return -ENOMEM;
+
+ bio_set_dev(bio, bdev);
+ bio->bi_iter.bi_sector = blk_zone_start(q, sector);
+ bio_set_op_attrs(bio, REQ_OP_ZONE_REPORT, 0);
+
+ for (i = 0; i < nr_pages; i++) {
+ page = alloc_page(gfp_mask);
+ if (!page) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ if (!bio_add_page(bio, page, PAGE_SIZE, 0)) {
+ __free_page(page);
+ break;
+ }
+ }
+
+ if (i == 0)
+ ret = -ENOMEM;
+ else
+ ret = submit_bio_wait(bio);
+ if (ret)
+ goto out;
+
+ /*
+ * Process the report result: skip the header and go through the
+ * reported zones to fixup and fixup the zone information for
+ * partitions. At the same time, return the zone information into
+ * the zone array.
+ */
+ n = 0;
+ nz = 0;
+ nr_rep = 0;
+ bio_for_each_segment_all(bv, bio, i) {
+
+ if (!bv->bv_page)
+ break;
+
+ addr = kmap_atomic(bv->bv_page);
+
+ /* Get header in the first page */
+ ofst = 0;
+ if (!nr_rep) {
+ hdr = (struct blk_zone_report_hdr *) addr;
+ nr_rep = hdr->nr_zones;
+ ofst = sizeof(struct blk_zone_report_hdr);
+ }
+
+ /* Fixup and report zones */
+ while (ofst < bv->bv_len &&
+ n < nr_rep && nz < nrz) {
+ if (blkdev_report_zone(bdev, addr + ofst, &zones[nz]))
+ nz++;
+ ofst += sizeof(struct blk_zone);
+ n++;
+ }
+
+ kunmap_atomic(addr);
+
+ if (n >= nr_rep || nz >= nrz)
+ break;
+
+ }
+
+ *nr_zones = nz;
+out:
+ bio_for_each_segment_all(bv, bio, i)
+ __free_page(bv->bv_page);
+ bio_put(bio);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blkdev_report_zones);
+
+/**
+ * blkdev_reset_zones - Reset zones write pointer
+ * @bdev: Target block device
+ * @sector: Start sector of the first zone to reset
+ * @nr_sectors: Number of sectors, at least the length of one zone
+ * @gfp_mask: Memory allocation flags (for bio_alloc)
+ *
+ * Description:
+ * Reset the write pointer of the zones contained in the range
+ * @sector..@sector+@nr_sectors. Specifying the entire disk sector range
+ * is valid, but the specified range should not contain conventional zones.
+ */
+int blkdev_reset_zones(struct block_device *bdev,
+ sector_t sector, sector_t nr_sectors,
+ gfp_t gfp_mask)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+ sector_t zone_sectors;
+ sector_t end_sector = sector + nr_sectors;
+ struct bio *bio;
+ int ret;
+
+ if (!q)
+ return -ENXIO;
+
+ if (!blk_queue_is_zoned(q))
+ return -EOPNOTSUPP;
+
+ if (end_sector > bdev->bd_part->nr_sects)
+ /* Out of range */
+ return -EINVAL;
+
+ /* Check alignment (handle eventual smaller last zone) */
+ zone_sectors = blk_queue_zone_sectors(q);
+ if (sector & (zone_sectors - 1))
+ return -EINVAL;
+
+ if ((nr_sectors & (zone_sectors - 1)) &&
+ end_sector != bdev->bd_part->nr_sects)
+ return -EINVAL;
+
+ while (sector < end_sector) {
+
+ bio = bio_alloc(gfp_mask, 0);
+ bio->bi_iter.bi_sector = sector;
+ bio_set_dev(bio, bdev);
+ bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
+
+ ret = submit_bio_wait(bio);
+ bio_put(bio);
+
+ if (ret)
+ return ret;
+
+ sector += zone_sectors;
+
+ /* This may take a while, so be nice to others */
+ cond_resched();
+
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkdev_reset_zones);
+
+/**
+ * BLKREPORTZONE ioctl processing.
+ * Called from blkdev_ioctl.
+ */
+int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
+ unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ struct request_queue *q;
+ struct blk_zone_report rep;
+ struct blk_zone *zones;
+ int ret;
+
+ if (!argp)
+ return -EINVAL;
+
+ q = bdev_get_queue(bdev);
+ if (!q)
+ return -ENXIO;
+
+ if (!blk_queue_is_zoned(q))
+ return -ENOTTY;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
+ return -EFAULT;
+
+ if (!rep.nr_zones)
+ return -EINVAL;
+
+ if (rep.nr_zones > INT_MAX / sizeof(struct blk_zone))
+ return -ERANGE;
+
+ zones = kvmalloc(rep.nr_zones * sizeof(struct blk_zone),
+ GFP_KERNEL | __GFP_ZERO);
+ if (!zones)
+ return -ENOMEM;
+
+ ret = blkdev_report_zones(bdev, rep.sector,
+ zones, &rep.nr_zones,
+ GFP_KERNEL);
+ if (ret)
+ goto out;
+
+ if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (rep.nr_zones) {
+ if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
+ sizeof(struct blk_zone) * rep.nr_zones))
+ ret = -EFAULT;
+ }
+
+ out:
+ kvfree(zones);
+
+ return ret;
+}
+
+/**
+ * BLKRESETZONE ioctl processing.
+ * Called from blkdev_ioctl.
+ */
+int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
+ unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ struct request_queue *q;
+ struct blk_zone_range zrange;
+
+ if (!argp)
+ return -EINVAL;
+
+ q = bdev_get_queue(bdev);
+ if (!q)
+ return -ENXIO;
+
+ if (!blk_queue_is_zoned(q))
+ return -ENOTTY;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (!(mode & FMODE_WRITE))
+ return -EBADF;
+
+ if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
+ return -EFAULT;
+
+ return blkdev_reset_zones(bdev, zrange.sector, zrange.nr_sectors,
+ GFP_KERNEL);
+}
diff --git a/src/kernel/linux/v4.14/block/blk.h b/src/kernel/linux/v4.14/block/blk.h
new file mode 100644
index 0000000..b2c287c
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/blk.h
@@ -0,0 +1,367 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BLK_INTERNAL_H
+#define BLK_INTERNAL_H
+
+#include <linux/idr.h>
+#include <linux/blk-mq.h>
+#include "blk-mq.h"
+
+/* Amount of time in which a process may batch requests */
+#define BLK_BATCH_TIME (HZ/50UL)
+
+/* Number of requests a "batching" process may submit */
+#define BLK_BATCH_REQ 32
+
+/* Max future timer expiry for timeouts */
+#define BLK_MAX_TIMEOUT (5 * HZ)
+
+#ifdef CONFIG_DEBUG_FS
+extern struct dentry *blk_debugfs_root;
+#endif
+
+struct blk_flush_queue {
+ unsigned int flush_queue_delayed:1;
+ unsigned int flush_pending_idx:1;
+ unsigned int flush_running_idx:1;
+ unsigned long flush_pending_since;
+ struct list_head flush_queue[2];
+ struct list_head flush_data_in_flight;
+ struct request *flush_rq;
+
+ /*
+ * flush_rq shares tag with this rq, both can't be active
+ * at the same time
+ */
+ struct request *orig_rq;
+ spinlock_t mq_flush_lock;
+};
+
+extern struct kmem_cache *blk_requestq_cachep;
+extern struct kmem_cache *request_cachep;
+extern struct kobj_type blk_queue_ktype;
+extern struct ida blk_queue_ida;
+
+static inline struct blk_flush_queue *blk_get_flush_queue(
+ struct request_queue *q, struct blk_mq_ctx *ctx)
+{
+ if (q->mq_ops)
+ return blk_mq_map_queue(q, ctx->cpu)->fq;
+ return q->fq;
+}
+
+static inline void __blk_get_queue(struct request_queue *q)
+{
+ kobject_get(&q->kobj);
+}
+
+struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
+ int node, int cmd_size);
+void blk_free_flush_queue(struct blk_flush_queue *q);
+
+int blk_init_rl(struct request_list *rl, struct request_queue *q,
+ gfp_t gfp_mask);
+void blk_exit_rl(struct request_queue *q, struct request_list *rl);
+void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
+ struct bio *bio);
+void blk_queue_bypass_start(struct request_queue *q);
+void blk_queue_bypass_end(struct request_queue *q);
+void __blk_queue_free_tags(struct request_queue *q);
+void blk_freeze_queue(struct request_queue *q);
+
+static inline void blk_queue_enter_live(struct request_queue *q)
+{
+ /*
+ * Given that running in generic_make_request() context
+ * guarantees that a live reference against q_usage_counter has
+ * been established, further references under that same context
+ * need not check that the queue has been frozen (marked dead).
+ */
+ percpu_ref_get(&q->q_usage_counter);
+}
+
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+void blk_flush_integrity(void);
+bool __bio_integrity_endio(struct bio *);
+static inline bool bio_integrity_endio(struct bio *bio)
+{
+ if (bio_integrity(bio))
+ return __bio_integrity_endio(bio);
+ return true;
+}
+#else
+static inline void blk_flush_integrity(void)
+{
+}
+static inline bool bio_integrity_endio(struct bio *bio)
+{
+ return true;
+}
+#endif
+
+void blk_timeout_work(struct work_struct *work);
+unsigned long blk_rq_timeout(unsigned long timeout);
+void blk_add_timer(struct request *req);
+void blk_delete_timer(struct request *);
+
+
+bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
+ struct bio *bio);
+bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
+ struct bio *bio);
+bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
+ struct bio *bio);
+bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
+ unsigned int *request_count,
+ struct request **same_queue_rq);
+unsigned int blk_plug_queued_count(struct request_queue *q);
+
+void blk_account_io_start(struct request *req, bool new_io);
+void blk_account_io_completion(struct request *req, unsigned int bytes);
+void blk_account_io_done(struct request *req);
+
+/*
+ * Internal atomic flags for request handling
+ */
+enum rq_atomic_flags {
+ REQ_ATOM_COMPLETE = 0,
+ REQ_ATOM_STARTED,
+ REQ_ATOM_POLL_SLEPT,
+};
+
+/*
+ * EH timer and IO completion will both attempt to 'grab' the request, make
+ * sure that only one of them succeeds
+ */
+static inline int blk_mark_rq_complete(struct request *rq)
+{
+ return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+static inline void blk_clear_rq_complete(struct request *rq)
+{
+ clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+/*
+ * Internal elevator interface
+ */
+#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
+
+void blk_insert_flush(struct request *rq);
+
+static inline struct request *__elv_next_request(struct request_queue *q)
+{
+ struct request *rq;
+ struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
+
+ WARN_ON_ONCE(q->mq_ops);
+
+ while (1) {
+ if (!list_empty(&q->queue_head)) {
+ rq = list_entry_rq(q->queue_head.next);
+ return rq;
+ }
+
+ /*
+ * Flush request is running and flush request isn't queueable
+ * in the drive, we can hold the queue till flush request is
+ * finished. Even we don't do this, driver can't dispatch next
+ * requests and will requeue them. And this can improve
+ * throughput too. For example, we have request flush1, write1,
+ * flush 2. flush1 is dispatched, then queue is hold, write1
+ * isn't inserted to queue. After flush1 is finished, flush2
+ * will be dispatched. Since disk cache is already clean,
+ * flush2 will be finished very soon, so looks like flush2 is
+ * folded to flush1.
+ * Since the queue is hold, a flag is set to indicate the queue
+ * should be restarted later. Please see flush_end_io() for
+ * details.
+ */
+ if (fq->flush_pending_idx != fq->flush_running_idx &&
+ !queue_flush_queueable(q)) {
+ fq->flush_queue_delayed = 1;
+ return NULL;
+ }
+ if (unlikely(blk_queue_bypass(q)) ||
+ !q->elevator->type->ops.sq.elevator_dispatch_fn(q, 0))
+ return NULL;
+ }
+}
+
+static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (e->type->ops.sq.elevator_activate_req_fn)
+ e->type->ops.sq.elevator_activate_req_fn(q, rq);
+}
+
+static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (e->type->ops.sq.elevator_deactivate_req_fn)
+ e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
+}
+
+struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
+
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+int blk_should_fake_timeout(struct request_queue *);
+ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
+ssize_t part_timeout_store(struct device *, struct device_attribute *,
+ const char *, size_t);
+#else
+static inline int blk_should_fake_timeout(struct request_queue *q)
+{
+ return 0;
+}
+#endif
+
+int ll_back_merge_fn(struct request_queue *q, struct request *req,
+ struct bio *bio);
+int ll_front_merge_fn(struct request_queue *q, struct request *req,
+ struct bio *bio);
+struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
+struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
+int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
+ struct request *next);
+void blk_recalc_rq_segments(struct request *rq);
+void blk_rq_set_mixed_merge(struct request *rq);
+bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
+enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
+
+void blk_queue_congestion_threshold(struct request_queue *q);
+
+int blk_dev_init(void);
+
+
+/*
+ * Return the threshold (number of used requests) at which the queue is
+ * considered to be congested. It include a little hysteresis to keep the
+ * context switch rate down.
+ */
+static inline int queue_congestion_on_threshold(struct request_queue *q)
+{
+ return q->nr_congestion_on;
+}
+
+/*
+ * The threshold at which a queue is considered to be uncongested
+ */
+static inline int queue_congestion_off_threshold(struct request_queue *q)
+{
+ return q->nr_congestion_off;
+}
+
+extern int blk_update_nr_requests(struct request_queue *, unsigned int);
+
+/*
+ * Contribute to IO statistics IFF:
+ *
+ * a) it's attached to a gendisk, and
+ * b) the queue had IO stats enabled when this request was started, and
+ * c) it's a file system request
+ */
+static inline int blk_do_io_stat(struct request *rq)
+{
+ return rq->rq_disk &&
+ (rq->rq_flags & RQF_IO_STAT) &&
+ !blk_rq_is_passthrough(rq);
+}
+
+static inline void req_set_nomerge(struct request_queue *q, struct request *req)
+{
+ req->cmd_flags |= REQ_NOMERGE;
+ if (req == q->last_merge)
+ q->last_merge = NULL;
+}
+
+/*
+ * Internal io_context interface
+ */
+void get_io_context(struct io_context *ioc);
+struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
+struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
+ gfp_t gfp_mask);
+void ioc_clear_queue(struct request_queue *q);
+
+int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
+
+/**
+ * rq_ioc - determine io_context for request allocation
+ * @bio: request being allocated is for this bio (can be %NULL)
+ *
+ * Determine io_context to use for request allocation for @bio. May return
+ * %NULL if %current->io_context doesn't exist.
+ */
+static inline struct io_context *rq_ioc(struct bio *bio)
+{
+#ifdef CONFIG_BLK_CGROUP
+ if (bio && bio->bi_ioc)
+ return bio->bi_ioc;
+#endif
+ return current->io_context;
+}
+
+/**
+ * create_io_context - try to create task->io_context
+ * @gfp_mask: allocation mask
+ * @node: allocation node
+ *
+ * If %current->io_context is %NULL, allocate a new io_context and install
+ * it. Returns the current %current->io_context which may be %NULL if
+ * allocation failed.
+ *
+ * Note that this function can't be called with IRQ disabled because
+ * task_lock which protects %current->io_context is IRQ-unsafe.
+ */
+static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
+{
+ WARN_ON_ONCE(irqs_disabled());
+ if (unlikely(!current->io_context))
+ create_task_io_context(current, gfp_mask, node);
+ return current->io_context;
+}
+
+/*
+ * Internal throttling interface
+ */
+#ifdef CONFIG_BLK_DEV_THROTTLING
+extern void blk_throtl_drain(struct request_queue *q);
+extern int blk_throtl_init(struct request_queue *q);
+extern void blk_throtl_exit(struct request_queue *q);
+extern void blk_throtl_register_queue(struct request_queue *q);
+#else /* CONFIG_BLK_DEV_THROTTLING */
+static inline void blk_throtl_drain(struct request_queue *q) { }
+static inline int blk_throtl_init(struct request_queue *q) { return 0; }
+static inline void blk_throtl_exit(struct request_queue *q) { }
+static inline void blk_throtl_register_queue(struct request_queue *q) { }
+#endif /* CONFIG_BLK_DEV_THROTTLING */
+#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
+extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
+extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
+ const char *page, size_t count);
+extern void blk_throtl_bio_endio(struct bio *bio);
+extern void blk_throtl_stat_add(struct request *rq, u64 time);
+#else
+static inline void blk_throtl_bio_endio(struct bio *bio) { }
+static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
+#endif
+
+#ifdef CONFIG_BOUNCE
+extern int init_emergency_isa_pool(void);
+extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
+#else
+static inline int init_emergency_isa_pool(void)
+{
+ return 0;
+}
+static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
+{
+}
+#endif /* CONFIG_BOUNCE */
+
+extern void blk_drain_queue(struct request_queue *q);
+
+#endif /* BLK_INTERNAL_H */
diff --git a/src/kernel/linux/v4.14/block/bounce.c b/src/kernel/linux/v4.14/block/bounce.c
new file mode 100644
index 0000000..1d05c42
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/bounce.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0
+/* bounce buffer handling for block devices
+ *
+ * - Split from highmem.c
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/swap.h>
+#include <linux/gfp.h>
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/mempool.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/init.h>
+#include <linux/hash.h>
+#include <linux/highmem.h>
+#include <linux/bootmem.h>
+#include <linux/printk.h>
+#include <asm/tlbflush.h>
+
+#include <trace/events/block.h>
+#include "blk.h"
+
+#define POOL_SIZE 64
+#define ISA_POOL_SIZE 16
+
+static struct bio_set *bounce_bio_set, *bounce_bio_split;
+static mempool_t *page_pool, *isa_page_pool;
+
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_NEED_BOUNCE_POOL)
+static __init int init_emergency_pool(void)
+{
+#if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG)
+ if (max_pfn <= max_low_pfn)
+ return 0;
+#endif
+
+ page_pool = mempool_create_page_pool(POOL_SIZE, 0);
+ BUG_ON(!page_pool);
+ pr_info("pool size: %d pages\n", POOL_SIZE);
+
+ bounce_bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
+ BUG_ON(!bounce_bio_set);
+ if (bioset_integrity_create(bounce_bio_set, BIO_POOL_SIZE))
+ BUG_ON(1);
+
+ bounce_bio_split = bioset_create(BIO_POOL_SIZE, 0, 0);
+ BUG_ON(!bounce_bio_split);
+
+ return 0;
+}
+
+__initcall(init_emergency_pool);
+#endif
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * highmem version, map in to vec
+ */
+static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom)
+{
+ unsigned long flags;
+ unsigned char *vto;
+
+ local_irq_save(flags);
+ vto = kmap_atomic(to->bv_page);
+ memcpy(vto + to->bv_offset, vfrom, to->bv_len);
+ kunmap_atomic(vto);
+ local_irq_restore(flags);
+}
+
+#else /* CONFIG_HIGHMEM */
+
+#define bounce_copy_vec(to, vfrom) \
+ memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len)
+
+#endif /* CONFIG_HIGHMEM */
+
+/*
+ * allocate pages in the DMA region for the ISA pool
+ */
+static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data)
+{
+ return mempool_alloc_pages(gfp_mask | GFP_DMA, data);
+}
+
+/*
+ * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA
+ * as the max address, so check if the pool has already been created.
+ */
+int init_emergency_isa_pool(void)
+{
+ if (isa_page_pool)
+ return 0;
+
+ isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa,
+ mempool_free_pages, (void *) 0);
+ BUG_ON(!isa_page_pool);
+
+ pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE);
+ return 0;
+}
+
+/*
+ * Simple bounce buffer support for highmem pages. Depending on the
+ * queue gfp mask set, *to may or may not be a highmem page. kmap it
+ * always, it will do the Right Thing
+ */
+static void copy_to_high_bio_irq(struct bio *to, struct bio *from)
+{
+ unsigned char *vfrom;
+ struct bio_vec tovec, *fromvec = from->bi_io_vec;
+ struct bvec_iter iter;
+
+ bio_for_each_segment(tovec, to, iter) {
+ if (tovec.bv_page != fromvec->bv_page) {
+ /*
+ * fromvec->bv_offset and fromvec->bv_len might have
+ * been modified by the block layer, so use the original
+ * copy, bounce_copy_vec already uses tovec->bv_len
+ */
+ vfrom = page_address(fromvec->bv_page) +
+ tovec.bv_offset;
+
+ bounce_copy_vec(&tovec, vfrom);
+ flush_dcache_page(tovec.bv_page);
+ }
+
+ fromvec++;
+ }
+}
+
+static void bounce_end_io(struct bio *bio, mempool_t *pool)
+{
+ struct bio *bio_orig = bio->bi_private;
+ struct bio_vec *bvec, *org_vec;
+ int i;
+ int start = bio_orig->bi_iter.bi_idx;
+
+ /*
+ * free up bounce indirect pages used
+ */
+ bio_for_each_segment_all(bvec, bio, i) {
+ org_vec = bio_orig->bi_io_vec + i + start;
+
+ if (bvec->bv_page == org_vec->bv_page)
+ continue;
+
+ dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
+ mempool_free(bvec->bv_page, pool);
+ }
+
+ bio_orig->bi_status = bio->bi_status;
+ bio_endio(bio_orig);
+ bio_put(bio);
+}
+
+static void bounce_end_io_write(struct bio *bio)
+{
+ bounce_end_io(bio, page_pool);
+}
+
+static void bounce_end_io_write_isa(struct bio *bio)
+{
+
+ bounce_end_io(bio, isa_page_pool);
+}
+
+static void __bounce_end_io_read(struct bio *bio, mempool_t *pool)
+{
+ struct bio *bio_orig = bio->bi_private;
+
+ if (!bio->bi_status)
+ copy_to_high_bio_irq(bio_orig, bio);
+
+ bounce_end_io(bio, pool);
+}
+
+static void bounce_end_io_read(struct bio *bio)
+{
+ __bounce_end_io_read(bio, page_pool);
+}
+
+static void bounce_end_io_read_isa(struct bio *bio)
+{
+ __bounce_end_io_read(bio, isa_page_pool);
+}
+
+static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
+ mempool_t *pool)
+{
+ struct bio *bio;
+ int rw = bio_data_dir(*bio_orig);
+ struct bio_vec *to, from;
+ struct bvec_iter iter;
+ unsigned i = 0;
+ bool bounce = false;
+ int sectors = 0;
+ bool passthrough = bio_is_passthrough(*bio_orig);
+
+ bio_for_each_segment(from, *bio_orig, iter) {
+ if (i++ < BIO_MAX_PAGES)
+ sectors += from.bv_len >> 9;
+ if (page_to_pfn(from.bv_page) > q->limits.bounce_pfn)
+ bounce = true;
+ }
+ if (!bounce)
+ return;
+
+ if (!passthrough && sectors < bio_sectors(*bio_orig)) {
+ bio = bio_split(*bio_orig, sectors, GFP_NOIO, bounce_bio_split);
+ bio_chain(bio, *bio_orig);
+ generic_make_request(*bio_orig);
+ *bio_orig = bio;
+ }
+ bio = bio_clone_bioset(*bio_orig, GFP_NOIO, passthrough ? NULL :
+ bounce_bio_set);
+
+ bio_for_each_segment_all(to, bio, i) {
+ struct page *page = to->bv_page;
+
+ if (page_to_pfn(page) <= q->limits.bounce_pfn)
+ continue;
+
+ to->bv_page = mempool_alloc(pool, q->bounce_gfp);
+ inc_zone_page_state(to->bv_page, NR_BOUNCE);
+
+ if (rw == WRITE) {
+ char *vto, *vfrom;
+
+ flush_dcache_page(page);
+
+ vto = page_address(to->bv_page) + to->bv_offset;
+ vfrom = kmap_atomic(page) + to->bv_offset;
+ memcpy(vto, vfrom, to->bv_len);
+ kunmap_atomic(vfrom);
+ }
+ }
+
+ trace_block_bio_bounce(q, *bio_orig);
+
+ bio->bi_flags |= (1 << BIO_BOUNCED);
+
+ if (pool == page_pool) {
+ bio->bi_end_io = bounce_end_io_write;
+ if (rw == READ)
+ bio->bi_end_io = bounce_end_io_read;
+ } else {
+ bio->bi_end_io = bounce_end_io_write_isa;
+ if (rw == READ)
+ bio->bi_end_io = bounce_end_io_read_isa;
+ }
+
+ bio->bi_private = *bio_orig;
+ *bio_orig = bio;
+}
+
+void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
+{
+ mempool_t *pool;
+
+ /*
+ * Data-less bio, nothing to bounce
+ */
+ if (!bio_has_data(*bio_orig))
+ return;
+
+ /*
+ * for non-isa bounce case, just check if the bounce pfn is equal
+ * to or bigger than the highest pfn in the system -- in that case,
+ * don't waste time iterating over bio segments
+ */
+ if (!(q->bounce_gfp & GFP_DMA)) {
+ if (q->limits.bounce_pfn >= blk_max_pfn)
+ return;
+ pool = page_pool;
+ } else {
+ BUG_ON(!isa_page_pool);
+ pool = isa_page_pool;
+ }
+
+ /*
+ * slow path
+ */
+ __blk_queue_bounce(q, bio_orig, pool);
+}
diff --git a/src/kernel/linux/v4.14/block/bsg-lib.c b/src/kernel/linux/v4.14/block/bsg-lib.c
new file mode 100644
index 0000000..15d25cc
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/bsg-lib.c
@@ -0,0 +1,294 @@
+/*
+ * BSG helper library
+ *
+ * Copyright (C) 2008 James Smart, Emulex Corporation
+ * Copyright (C) 2011 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2011 Mike Christie
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/scatterlist.h>
+#include <linux/bsg-lib.h>
+#include <linux/export.h>
+#include <scsi/scsi_cmnd.h>
+
+/**
+ * bsg_teardown_job - routine to teardown a bsg job
+ * @job: bsg_job that is to be torn down
+ */
+static void bsg_teardown_job(struct kref *kref)
+{
+ struct bsg_job *job = container_of(kref, struct bsg_job, kref);
+ struct request *rq = job->req;
+
+ put_device(job->dev); /* release reference for the request */
+
+ kfree(job->request_payload.sg_list);
+ kfree(job->reply_payload.sg_list);
+
+ blk_end_request_all(rq, BLK_STS_OK);
+}
+
+void bsg_job_put(struct bsg_job *job)
+{
+ kref_put(&job->kref, bsg_teardown_job);
+}
+EXPORT_SYMBOL_GPL(bsg_job_put);
+
+int bsg_job_get(struct bsg_job *job)
+{
+ return kref_get_unless_zero(&job->kref);
+}
+EXPORT_SYMBOL_GPL(bsg_job_get);
+
+/**
+ * bsg_job_done - completion routine for bsg requests
+ * @job: bsg_job that is complete
+ * @result: job reply result
+ * @reply_payload_rcv_len: length of payload recvd
+ *
+ * The LLD should call this when the bsg job has completed.
+ */
+void bsg_job_done(struct bsg_job *job, int result,
+ unsigned int reply_payload_rcv_len)
+{
+ struct request *req = job->req;
+ struct request *rsp = req->next_rq;
+ struct scsi_request *rq = scsi_req(req);
+ int err;
+
+ err = scsi_req(job->req)->result = result;
+ if (err < 0)
+ /* we're only returning the result field in the reply */
+ rq->sense_len = sizeof(u32);
+ else
+ rq->sense_len = job->reply_len;
+ /* we assume all request payload was transferred, residual == 0 */
+ rq->resid_len = 0;
+
+ if (rsp) {
+ WARN_ON(reply_payload_rcv_len > scsi_req(rsp)->resid_len);
+
+ /* set reply (bidi) residual */
+ scsi_req(rsp)->resid_len -=
+ min(reply_payload_rcv_len, scsi_req(rsp)->resid_len);
+ }
+ blk_complete_request(req);
+}
+EXPORT_SYMBOL_GPL(bsg_job_done);
+
+/**
+ * bsg_softirq_done - softirq done routine for destroying the bsg requests
+ * @rq: BSG request that holds the job to be destroyed
+ */
+static void bsg_softirq_done(struct request *rq)
+{
+ struct bsg_job *job = blk_mq_rq_to_pdu(rq);
+
+ bsg_job_put(job);
+}
+
+static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
+{
+ size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
+
+ BUG_ON(!req->nr_phys_segments);
+
+ buf->sg_list = kzalloc(sz, GFP_KERNEL);
+ if (!buf->sg_list)
+ return -ENOMEM;
+ sg_init_table(buf->sg_list, req->nr_phys_segments);
+ scsi_req(req)->resid_len = blk_rq_bytes(req);
+ buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
+ buf->payload_len = blk_rq_bytes(req);
+ return 0;
+}
+
+/**
+ * bsg_prepare_job - create the bsg_job structure for the bsg request
+ * @dev: device that is being sent the bsg request
+ * @req: BSG request that needs a job structure
+ */
+static int bsg_prepare_job(struct device *dev, struct request *req)
+{
+ struct request *rsp = req->next_rq;
+ struct scsi_request *rq = scsi_req(req);
+ struct bsg_job *job = blk_mq_rq_to_pdu(req);
+ int ret;
+
+ job->request = rq->cmd;
+ job->request_len = rq->cmd_len;
+
+ if (req->bio) {
+ ret = bsg_map_buffer(&job->request_payload, req);
+ if (ret)
+ goto failjob_rls_job;
+ }
+ if (rsp && rsp->bio) {
+ ret = bsg_map_buffer(&job->reply_payload, rsp);
+ if (ret)
+ goto failjob_rls_rqst_payload;
+ }
+ job->dev = dev;
+ /* take a reference for the request */
+ get_device(job->dev);
+ kref_init(&job->kref);
+ return 0;
+
+failjob_rls_rqst_payload:
+ kfree(job->request_payload.sg_list);
+failjob_rls_job:
+ return -ENOMEM;
+}
+
+/**
+ * bsg_request_fn - generic handler for bsg requests
+ * @q: request queue to manage
+ *
+ * On error the create_bsg_job function should return a -Exyz error value
+ * that will be set to ->result.
+ *
+ * Drivers/subsys should pass this to the queue init function.
+ */
+static void bsg_request_fn(struct request_queue *q)
+ __releases(q->queue_lock)
+ __acquires(q->queue_lock)
+{
+ struct device *dev = q->queuedata;
+ struct request *req;
+ int ret;
+
+ if (!get_device(dev))
+ return;
+
+ while (1) {
+ req = blk_fetch_request(q);
+ if (!req)
+ break;
+ spin_unlock_irq(q->queue_lock);
+
+ ret = bsg_prepare_job(dev, req);
+ if (ret) {
+ scsi_req(req)->result = ret;
+ blk_end_request_all(req, BLK_STS_OK);
+ spin_lock_irq(q->queue_lock);
+ continue;
+ }
+
+ ret = q->bsg_job_fn(blk_mq_rq_to_pdu(req));
+ spin_lock_irq(q->queue_lock);
+ if (ret)
+ break;
+ }
+
+ spin_unlock_irq(q->queue_lock);
+ put_device(dev);
+ spin_lock_irq(q->queue_lock);
+}
+
+static int bsg_init_rq(struct request_queue *q, struct request *req, gfp_t gfp)
+{
+ struct bsg_job *job = blk_mq_rq_to_pdu(req);
+ struct scsi_request *sreq = &job->sreq;
+
+ /* called right after the request is allocated for the request_queue */
+
+ sreq->sense = kzalloc(SCSI_SENSE_BUFFERSIZE, gfp);
+ if (!sreq->sense)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void bsg_initialize_rq(struct request *req)
+{
+ struct bsg_job *job = blk_mq_rq_to_pdu(req);
+ struct scsi_request *sreq = &job->sreq;
+ void *sense = sreq->sense;
+
+ /* called right before the request is given to the request_queue user */
+
+ memset(job, 0, sizeof(*job));
+
+ scsi_req_init(sreq);
+
+ sreq->sense = sense;
+ sreq->sense_len = SCSI_SENSE_BUFFERSIZE;
+
+ job->req = req;
+ job->reply = sense;
+ job->reply_len = sreq->sense_len;
+ job->dd_data = job + 1;
+}
+
+static void bsg_exit_rq(struct request_queue *q, struct request *req)
+{
+ struct bsg_job *job = blk_mq_rq_to_pdu(req);
+ struct scsi_request *sreq = &job->sreq;
+
+ kfree(sreq->sense);
+}
+
+/**
+ * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
+ * @dev: device to attach bsg device to
+ * @name: device to give bsg device
+ * @job_fn: bsg job handler
+ * @dd_job_size: size of LLD data needed for each job
+ */
+struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
+ bsg_job_fn *job_fn, int dd_job_size,
+ void (*release)(struct device *))
+{
+ struct request_queue *q;
+ int ret;
+
+ q = blk_alloc_queue(GFP_KERNEL);
+ if (!q)
+ return ERR_PTR(-ENOMEM);
+ q->cmd_size = sizeof(struct bsg_job) + dd_job_size;
+ q->init_rq_fn = bsg_init_rq;
+ q->exit_rq_fn = bsg_exit_rq;
+ q->initialize_rq_fn = bsg_initialize_rq;
+ q->request_fn = bsg_request_fn;
+
+ ret = blk_init_allocated_queue(q);
+ if (ret)
+ goto out_cleanup_queue;
+
+ q->queuedata = dev;
+ q->bsg_job_fn = job_fn;
+ queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
+ queue_flag_set_unlocked(QUEUE_FLAG_SCSI_PASSTHROUGH, q);
+ blk_queue_softirq_done(q, bsg_softirq_done);
+ blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
+
+ ret = bsg_register_queue(q, dev, name, release);
+ if (ret) {
+ printk(KERN_ERR "%s: bsg interface failed to "
+ "initialize - register queue\n", dev->kobj.name);
+ goto out_cleanup_queue;
+ }
+
+ return q;
+out_cleanup_queue:
+ blk_cleanup_queue(q);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(bsg_setup_queue);
diff --git a/src/kernel/linux/v4.14/block/bsg.c b/src/kernel/linux/v4.14/block/bsg.c
new file mode 100644
index 0000000..ee1335c
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/bsg.c
@@ -0,0 +1,1092 @@
+/*
+ * bsg.c - block layer implementation of the sg v4 interface
+ *
+ * Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs
+ * Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License version 2. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/file.h>
+#include <linux/blkdev.h>
+#include <linux/poll.h>
+#include <linux/cdev.h>
+#include <linux/jiffies.h>
+#include <linux/percpu.h>
+#include <linux/uio.h>
+#include <linux/idr.h>
+#include <linux/bsg.h>
+#include <linux/slab.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_ioctl.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
+#include <scsi/sg.h>
+
+#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
+#define BSG_VERSION "0.4"
+
+struct bsg_device {
+ struct request_queue *queue;
+ spinlock_t lock;
+ struct list_head busy_list;
+ struct list_head done_list;
+ struct hlist_node dev_list;
+ atomic_t ref_count;
+ int queued_cmds;
+ int done_cmds;
+ wait_queue_head_t wq_done;
+ wait_queue_head_t wq_free;
+ char name[20];
+ int max_queue;
+ unsigned long flags;
+};
+
+enum {
+ BSG_F_BLOCK = 1,
+};
+
+#define BSG_DEFAULT_CMDS 64
+#define BSG_MAX_DEVS 32768
+
+#undef BSG_DEBUG
+
+#ifdef BSG_DEBUG
+#define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args)
+#else
+#define dprintk(fmt, args...)
+#endif
+
+static DEFINE_MUTEX(bsg_mutex);
+static DEFINE_IDR(bsg_minor_idr);
+
+#define BSG_LIST_ARRAY_SIZE 8
+static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
+
+static struct class *bsg_class;
+static int bsg_major;
+
+static struct kmem_cache *bsg_cmd_cachep;
+
+/*
+ * our internal command type
+ */
+struct bsg_command {
+ struct bsg_device *bd;
+ struct list_head list;
+ struct request *rq;
+ struct bio *bio;
+ struct bio *bidi_bio;
+ int err;
+ struct sg_io_v4 hdr;
+};
+
+static void bsg_free_command(struct bsg_command *bc)
+{
+ struct bsg_device *bd = bc->bd;
+ unsigned long flags;
+
+ kmem_cache_free(bsg_cmd_cachep, bc);
+
+ spin_lock_irqsave(&bd->lock, flags);
+ bd->queued_cmds--;
+ spin_unlock_irqrestore(&bd->lock, flags);
+
+ wake_up(&bd->wq_free);
+}
+
+static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
+{
+ struct bsg_command *bc = ERR_PTR(-EINVAL);
+
+ spin_lock_irq(&bd->lock);
+
+ if (bd->queued_cmds >= bd->max_queue)
+ goto out;
+
+ bd->queued_cmds++;
+ spin_unlock_irq(&bd->lock);
+
+ bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
+ if (unlikely(!bc)) {
+ spin_lock_irq(&bd->lock);
+ bd->queued_cmds--;
+ bc = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ bc->bd = bd;
+ INIT_LIST_HEAD(&bc->list);
+ dprintk("%s: returning free cmd %p\n", bd->name, bc);
+ return bc;
+out:
+ spin_unlock_irq(&bd->lock);
+ return bc;
+}
+
+static inline struct hlist_head *bsg_dev_idx_hash(int index)
+{
+ return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
+}
+
+static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
+ struct sg_io_v4 *hdr, struct bsg_device *bd,
+ fmode_t has_write_perm)
+{
+ struct scsi_request *req = scsi_req(rq);
+
+ if (hdr->request_len > BLK_MAX_CDB) {
+ req->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
+ if (!req->cmd)
+ return -ENOMEM;
+ }
+
+ if (copy_from_user(req->cmd, (void __user *)(unsigned long)hdr->request,
+ hdr->request_len))
+ return -EFAULT;
+
+ if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
+ if (blk_verify_command(req->cmd, has_write_perm))
+ return -EPERM;
+ } else if (!capable(CAP_SYS_RAWIO))
+ return -EPERM;
+
+ /*
+ * fill in request structure
+ */
+ req->cmd_len = hdr->request_len;
+
+ rq->timeout = msecs_to_jiffies(hdr->timeout);
+ if (!rq->timeout)
+ rq->timeout = q->sg_timeout;
+ if (!rq->timeout)
+ rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
+ if (rq->timeout < BLK_MIN_SG_TIMEOUT)
+ rq->timeout = BLK_MIN_SG_TIMEOUT;
+
+ return 0;
+}
+
+/*
+ * Check if sg_io_v4 from user is allowed and valid
+ */
+static int
+bsg_validate_sgv4_hdr(struct sg_io_v4 *hdr, int *op)
+{
+ int ret = 0;
+
+ if (hdr->guard != 'Q')
+ return -EINVAL;
+
+ switch (hdr->protocol) {
+ case BSG_PROTOCOL_SCSI:
+ switch (hdr->subprotocol) {
+ case BSG_SUB_PROTOCOL_SCSI_CMD:
+ case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ *op = hdr->dout_xfer_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN;
+ return ret;
+}
+
+/*
+ * map sg_io_v4 to a request.
+ */
+static struct request *
+bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm)
+{
+ struct request_queue *q = bd->queue;
+ struct request *rq, *next_rq = NULL;
+ int ret;
+ unsigned int op, dxfer_len;
+ void __user *dxferp = NULL;
+ struct bsg_class_device *bcd = &q->bsg_dev;
+
+ /* if the LLD has been removed then the bsg_unregister_queue will
+ * eventually be called and the class_dev was freed, so we can no
+ * longer use this request_queue. Return no such address.
+ */
+ if (!bcd->class_dev)
+ return ERR_PTR(-ENXIO);
+
+ dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
+ hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
+ hdr->din_xfer_len);
+
+ ret = bsg_validate_sgv4_hdr(hdr, &op);
+ if (ret)
+ return ERR_PTR(ret);
+
+ /*
+ * map scatter-gather elements separately and string them to request
+ */
+ rq = blk_get_request(q, op, GFP_KERNEL);
+ if (IS_ERR(rq))
+ return rq;
+
+ ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
+ if (ret)
+ goto out;
+
+ if (op == REQ_OP_SCSI_OUT && hdr->din_xfer_len) {
+ if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ next_rq = blk_get_request(q, REQ_OP_SCSI_IN, GFP_KERNEL);
+ if (IS_ERR(next_rq)) {
+ ret = PTR_ERR(next_rq);
+ next_rq = NULL;
+ goto out;
+ }
+ rq->next_rq = next_rq;
+
+ dxferp = (void __user *)(unsigned long)hdr->din_xferp;
+ ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
+ hdr->din_xfer_len, GFP_KERNEL);
+ if (ret)
+ goto out;
+ }
+
+ if (hdr->dout_xfer_len) {
+ dxfer_len = hdr->dout_xfer_len;
+ dxferp = (void __user *)(unsigned long)hdr->dout_xferp;
+ } else if (hdr->din_xfer_len) {
+ dxfer_len = hdr->din_xfer_len;
+ dxferp = (void __user *)(unsigned long)hdr->din_xferp;
+ } else
+ dxfer_len = 0;
+
+ if (dxfer_len) {
+ ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
+ GFP_KERNEL);
+ if (ret)
+ goto out;
+ }
+
+ return rq;
+out:
+ scsi_req_free_cmd(scsi_req(rq));
+ blk_put_request(rq);
+ if (next_rq) {
+ blk_rq_unmap_user(next_rq->bio);
+ blk_put_request(next_rq);
+ }
+ return ERR_PTR(ret);
+}
+
+/*
+ * async completion call-back from the block layer, when scsi/ide/whatever
+ * calls end_that_request_last() on a request
+ */
+static void bsg_rq_end_io(struct request *rq, blk_status_t status)
+{
+ struct bsg_command *bc = rq->end_io_data;
+ struct bsg_device *bd = bc->bd;
+ unsigned long flags;
+
+ dprintk("%s: finished rq %p bc %p, bio %p\n",
+ bd->name, rq, bc, bc->bio);
+
+ bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
+
+ spin_lock_irqsave(&bd->lock, flags);
+ list_move_tail(&bc->list, &bd->done_list);
+ bd->done_cmds++;
+ spin_unlock_irqrestore(&bd->lock, flags);
+
+ wake_up(&bd->wq_done);
+}
+
+/*
+ * do final setup of a 'bc' and submit the matching 'rq' to the block
+ * layer for io
+ */
+static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
+ struct bsg_command *bc, struct request *rq)
+{
+ int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
+
+ /*
+ * add bc command to busy queue and submit rq for io
+ */
+ bc->rq = rq;
+ bc->bio = rq->bio;
+ if (rq->next_rq)
+ bc->bidi_bio = rq->next_rq->bio;
+ bc->hdr.duration = jiffies;
+ spin_lock_irq(&bd->lock);
+ list_add_tail(&bc->list, &bd->busy_list);
+ spin_unlock_irq(&bd->lock);
+
+ dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
+
+ rq->end_io_data = bc;
+ blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
+}
+
+static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
+{
+ struct bsg_command *bc = NULL;
+
+ spin_lock_irq(&bd->lock);
+ if (bd->done_cmds) {
+ bc = list_first_entry(&bd->done_list, struct bsg_command, list);
+ list_del(&bc->list);
+ bd->done_cmds--;
+ }
+ spin_unlock_irq(&bd->lock);
+
+ return bc;
+}
+
+/*
+ * Get a finished command from the done list
+ */
+static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
+{
+ struct bsg_command *bc;
+ int ret;
+
+ do {
+ bc = bsg_next_done_cmd(bd);
+ if (bc)
+ break;
+
+ if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
+ bc = ERR_PTR(-EAGAIN);
+ break;
+ }
+
+ ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
+ if (ret) {
+ bc = ERR_PTR(-ERESTARTSYS);
+ break;
+ }
+ } while (1);
+
+ dprintk("%s: returning done %p\n", bd->name, bc);
+
+ return bc;
+}
+
+static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
+ struct bio *bio, struct bio *bidi_bio)
+{
+ struct scsi_request *req = scsi_req(rq);
+ int ret = 0;
+
+ dprintk("rq %p bio %p 0x%x\n", rq, bio, req->result);
+ /*
+ * fill in all the output members
+ */
+ hdr->device_status = req->result & 0xff;
+ hdr->transport_status = host_byte(req->result);
+ hdr->driver_status = driver_byte(req->result);
+ hdr->info = 0;
+ if (hdr->device_status || hdr->transport_status || hdr->driver_status)
+ hdr->info |= SG_INFO_CHECK;
+ hdr->response_len = 0;
+
+ if (req->sense_len && hdr->response) {
+ int len = min_t(unsigned int, hdr->max_response_len,
+ req->sense_len);
+
+ ret = copy_to_user((void __user *)(unsigned long)hdr->response,
+ req->sense, len);
+ if (!ret)
+ hdr->response_len = len;
+ else
+ ret = -EFAULT;
+ }
+
+ if (rq->next_rq) {
+ hdr->dout_resid = req->resid_len;
+ hdr->din_resid = scsi_req(rq->next_rq)->resid_len;
+ blk_rq_unmap_user(bidi_bio);
+ blk_put_request(rq->next_rq);
+ } else if (rq_data_dir(rq) == READ)
+ hdr->din_resid = req->resid_len;
+ else
+ hdr->dout_resid = req->resid_len;
+
+ /*
+ * If the request generated a negative error number, return it
+ * (providing we aren't already returning an error); if it's
+ * just a protocol response (i.e. non negative), that gets
+ * processed above.
+ */
+ if (!ret && req->result < 0)
+ ret = req->result;
+
+ blk_rq_unmap_user(bio);
+ scsi_req_free_cmd(req);
+ blk_put_request(rq);
+
+ return ret;
+}
+
+static bool bsg_complete(struct bsg_device *bd)
+{
+ bool ret = false;
+ bool spin;
+
+ do {
+ spin_lock_irq(&bd->lock);
+
+ BUG_ON(bd->done_cmds > bd->queued_cmds);
+
+ /*
+ * All commands consumed.
+ */
+ if (bd->done_cmds == bd->queued_cmds)
+ ret = true;
+
+ spin = !test_bit(BSG_F_BLOCK, &bd->flags);
+
+ spin_unlock_irq(&bd->lock);
+ } while (!ret && spin);
+
+ return ret;
+}
+
+static int bsg_complete_all_commands(struct bsg_device *bd)
+{
+ struct bsg_command *bc;
+ int ret, tret;
+
+ dprintk("%s: entered\n", bd->name);
+
+ /*
+ * wait for all commands to complete
+ */
+ io_wait_event(bd->wq_done, bsg_complete(bd));
+
+ /*
+ * discard done commands
+ */
+ ret = 0;
+ do {
+ spin_lock_irq(&bd->lock);
+ if (!bd->queued_cmds) {
+ spin_unlock_irq(&bd->lock);
+ break;
+ }
+ spin_unlock_irq(&bd->lock);
+
+ bc = bsg_get_done_cmd(bd);
+ if (IS_ERR(bc))
+ break;
+
+ tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
+ bc->bidi_bio);
+ if (!ret)
+ ret = tret;
+
+ bsg_free_command(bc);
+ } while (1);
+
+ return ret;
+}
+
+static int
+__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
+ const struct iovec *iov, ssize_t *bytes_read)
+{
+ struct bsg_command *bc;
+ int nr_commands, ret;
+
+ if (count % sizeof(struct sg_io_v4))
+ return -EINVAL;
+
+ ret = 0;
+ nr_commands = count / sizeof(struct sg_io_v4);
+ while (nr_commands) {
+ bc = bsg_get_done_cmd(bd);
+ if (IS_ERR(bc)) {
+ ret = PTR_ERR(bc);
+ break;
+ }
+
+ /*
+ * this is the only case where we need to copy data back
+ * after completing the request. so do that here,
+ * bsg_complete_work() cannot do that for us
+ */
+ ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
+ bc->bidi_bio);
+
+ if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
+ ret = -EFAULT;
+
+ bsg_free_command(bc);
+
+ if (ret)
+ break;
+
+ buf += sizeof(struct sg_io_v4);
+ *bytes_read += sizeof(struct sg_io_v4);
+ nr_commands--;
+ }
+
+ return ret;
+}
+
+static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
+{
+ if (file->f_flags & O_NONBLOCK)
+ clear_bit(BSG_F_BLOCK, &bd->flags);
+ else
+ set_bit(BSG_F_BLOCK, &bd->flags);
+}
+
+/*
+ * Check if the error is a "real" error that we should return.
+ */
+static inline int err_block_err(int ret)
+{
+ if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
+ return 1;
+
+ return 0;
+}
+
+static ssize_t
+bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+ struct bsg_device *bd = file->private_data;
+ int ret;
+ ssize_t bytes_read;
+
+ dprintk("%s: read %zd bytes\n", bd->name, count);
+
+ bsg_set_block(bd, file);
+
+ bytes_read = 0;
+ ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
+ *ppos = bytes_read;
+
+ if (!bytes_read || err_block_err(ret))
+ bytes_read = ret;
+
+ return bytes_read;
+}
+
+static int __bsg_write(struct bsg_device *bd, const char __user *buf,
+ size_t count, ssize_t *bytes_written,
+ fmode_t has_write_perm)
+{
+ struct bsg_command *bc;
+ struct request *rq;
+ int ret, nr_commands;
+
+ if (count % sizeof(struct sg_io_v4))
+ return -EINVAL;
+
+ nr_commands = count / sizeof(struct sg_io_v4);
+ rq = NULL;
+ bc = NULL;
+ ret = 0;
+ while (nr_commands) {
+ struct request_queue *q = bd->queue;
+
+ bc = bsg_alloc_command(bd);
+ if (IS_ERR(bc)) {
+ ret = PTR_ERR(bc);
+ bc = NULL;
+ break;
+ }
+
+ if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
+ ret = -EFAULT;
+ break;
+ }
+
+ /*
+ * get a request, fill in the blanks, and add to request queue
+ */
+ rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm);
+ if (IS_ERR(rq)) {
+ ret = PTR_ERR(rq);
+ rq = NULL;
+ break;
+ }
+
+ bsg_add_command(bd, q, bc, rq);
+ bc = NULL;
+ rq = NULL;
+ nr_commands--;
+ buf += sizeof(struct sg_io_v4);
+ *bytes_written += sizeof(struct sg_io_v4);
+ }
+
+ if (bc)
+ bsg_free_command(bc);
+
+ return ret;
+}
+
+static ssize_t
+bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+ struct bsg_device *bd = file->private_data;
+ ssize_t bytes_written;
+ int ret;
+
+ dprintk("%s: write %zd bytes\n", bd->name, count);
+
+ if (unlikely(uaccess_kernel()))
+ return -EINVAL;
+
+ bsg_set_block(bd, file);
+
+ bytes_written = 0;
+ ret = __bsg_write(bd, buf, count, &bytes_written,
+ file->f_mode & FMODE_WRITE);
+
+ *ppos = bytes_written;
+
+ /*
+ * return bytes written on non-fatal errors
+ */
+ if (!bytes_written || err_block_err(ret))
+ bytes_written = ret;
+
+ dprintk("%s: returning %zd\n", bd->name, bytes_written);
+ return bytes_written;
+}
+
+static struct bsg_device *bsg_alloc_device(void)
+{
+ struct bsg_device *bd;
+
+ bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
+ if (unlikely(!bd))
+ return NULL;
+
+ spin_lock_init(&bd->lock);
+
+ bd->max_queue = BSG_DEFAULT_CMDS;
+
+ INIT_LIST_HEAD(&bd->busy_list);
+ INIT_LIST_HEAD(&bd->done_list);
+ INIT_HLIST_NODE(&bd->dev_list);
+
+ init_waitqueue_head(&bd->wq_free);
+ init_waitqueue_head(&bd->wq_done);
+ return bd;
+}
+
+static void bsg_kref_release_function(struct kref *kref)
+{
+ struct bsg_class_device *bcd =
+ container_of(kref, struct bsg_class_device, ref);
+ struct device *parent = bcd->parent;
+
+ if (bcd->release)
+ bcd->release(bcd->parent);
+
+ put_device(parent);
+}
+
+static int bsg_put_device(struct bsg_device *bd)
+{
+ int ret = 0, do_free;
+ struct request_queue *q = bd->queue;
+
+ mutex_lock(&bsg_mutex);
+
+ do_free = atomic_dec_and_test(&bd->ref_count);
+ if (!do_free) {
+ mutex_unlock(&bsg_mutex);
+ goto out;
+ }
+
+ hlist_del(&bd->dev_list);
+ mutex_unlock(&bsg_mutex);
+
+ dprintk("%s: tearing down\n", bd->name);
+
+ /*
+ * close can always block
+ */
+ set_bit(BSG_F_BLOCK, &bd->flags);
+
+ /*
+ * correct error detection baddies here again. it's the responsibility
+ * of the app to properly reap commands before close() if it wants
+ * fool-proof error detection
+ */
+ ret = bsg_complete_all_commands(bd);
+
+ kfree(bd);
+out:
+ kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
+ if (do_free)
+ blk_put_queue(q);
+ return ret;
+}
+
+static struct bsg_device *bsg_add_device(struct inode *inode,
+ struct request_queue *rq,
+ struct file *file)
+{
+ struct bsg_device *bd;
+#ifdef BSG_DEBUG
+ unsigned char buf[32];
+#endif
+
+ if (!blk_queue_scsi_passthrough(rq)) {
+ WARN_ONCE(true, "Attempt to register a non-SCSI queue\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!blk_get_queue(rq))
+ return ERR_PTR(-ENXIO);
+
+ bd = bsg_alloc_device();
+ if (!bd) {
+ blk_put_queue(rq);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ bd->queue = rq;
+
+ bsg_set_block(bd, file);
+
+ atomic_set(&bd->ref_count, 1);
+ mutex_lock(&bsg_mutex);
+ hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
+
+ strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
+ dprintk("bound to <%s>, max queue %d\n",
+ format_dev_t(buf, inode->i_rdev), bd->max_queue);
+
+ mutex_unlock(&bsg_mutex);
+ return bd;
+}
+
+static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
+{
+ struct bsg_device *bd;
+
+ mutex_lock(&bsg_mutex);
+
+ hlist_for_each_entry(bd, bsg_dev_idx_hash(minor), dev_list) {
+ if (bd->queue == q) {
+ atomic_inc(&bd->ref_count);
+ goto found;
+ }
+ }
+ bd = NULL;
+found:
+ mutex_unlock(&bsg_mutex);
+ return bd;
+}
+
+static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
+{
+ struct bsg_device *bd;
+ struct bsg_class_device *bcd;
+
+ /*
+ * find the class device
+ */
+ mutex_lock(&bsg_mutex);
+ bcd = idr_find(&bsg_minor_idr, iminor(inode));
+ if (bcd)
+ kref_get(&bcd->ref);
+ mutex_unlock(&bsg_mutex);
+
+ if (!bcd)
+ return ERR_PTR(-ENODEV);
+
+ bd = __bsg_get_device(iminor(inode), bcd->queue);
+ if (bd)
+ return bd;
+
+ bd = bsg_add_device(inode, bcd->queue, file);
+ if (IS_ERR(bd))
+ kref_put(&bcd->ref, bsg_kref_release_function);
+
+ return bd;
+}
+
+static int bsg_open(struct inode *inode, struct file *file)
+{
+ struct bsg_device *bd;
+
+ bd = bsg_get_device(inode, file);
+
+ if (IS_ERR(bd))
+ return PTR_ERR(bd);
+
+ file->private_data = bd;
+ return 0;
+}
+
+static int bsg_release(struct inode *inode, struct file *file)
+{
+ struct bsg_device *bd = file->private_data;
+
+ file->private_data = NULL;
+ return bsg_put_device(bd);
+}
+
+static unsigned int bsg_poll(struct file *file, poll_table *wait)
+{
+ struct bsg_device *bd = file->private_data;
+ unsigned int mask = 0;
+
+ poll_wait(file, &bd->wq_done, wait);
+ poll_wait(file, &bd->wq_free, wait);
+
+ spin_lock_irq(&bd->lock);
+ if (!list_empty(&bd->done_list))
+ mask |= POLLIN | POLLRDNORM;
+ if (bd->queued_cmds < bd->max_queue)
+ mask |= POLLOUT;
+ spin_unlock_irq(&bd->lock);
+
+ return mask;
+}
+
+static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct bsg_device *bd = file->private_data;
+ int __user *uarg = (int __user *) arg;
+ int ret;
+
+ switch (cmd) {
+ /*
+ * our own ioctls
+ */
+ case SG_GET_COMMAND_Q:
+ return put_user(bd->max_queue, uarg);
+ case SG_SET_COMMAND_Q: {
+ int queue;
+
+ if (get_user(queue, uarg))
+ return -EFAULT;
+ if (queue < 1)
+ return -EINVAL;
+
+ spin_lock_irq(&bd->lock);
+ bd->max_queue = queue;
+ spin_unlock_irq(&bd->lock);
+ return 0;
+ }
+
+ /*
+ * SCSI/sg ioctls
+ */
+ case SG_GET_VERSION_NUM:
+ case SCSI_IOCTL_GET_IDLUN:
+ case SCSI_IOCTL_GET_BUS_NUMBER:
+ case SG_SET_TIMEOUT:
+ case SG_GET_TIMEOUT:
+ case SG_GET_RESERVED_SIZE:
+ case SG_SET_RESERVED_SIZE:
+ case SG_EMULATED_HOST:
+ case SCSI_IOCTL_SEND_COMMAND: {
+ void __user *uarg = (void __user *) arg;
+ return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
+ }
+ case SG_IO: {
+ struct request *rq;
+ struct bio *bio, *bidi_bio = NULL;
+ struct sg_io_v4 hdr;
+ int at_head;
+
+ if (copy_from_user(&hdr, uarg, sizeof(hdr)))
+ return -EFAULT;
+
+ rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE);
+ if (IS_ERR(rq))
+ return PTR_ERR(rq);
+
+ bio = rq->bio;
+ if (rq->next_rq)
+ bidi_bio = rq->next_rq->bio;
+
+ at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
+ blk_execute_rq(bd->queue, NULL, rq, at_head);
+ ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
+
+ if (copy_to_user(uarg, &hdr, sizeof(hdr)))
+ return -EFAULT;
+
+ return ret;
+ }
+ default:
+ return -ENOTTY;
+ }
+}
+
+static const struct file_operations bsg_fops = {
+ .read = bsg_read,
+ .write = bsg_write,
+ .poll = bsg_poll,
+ .open = bsg_open,
+ .release = bsg_release,
+ .unlocked_ioctl = bsg_ioctl,
+ .owner = THIS_MODULE,
+ .llseek = default_llseek,
+};
+
+void bsg_unregister_queue(struct request_queue *q)
+{
+ struct bsg_class_device *bcd = &q->bsg_dev;
+
+ if (!bcd->class_dev)
+ return;
+
+ mutex_lock(&bsg_mutex);
+ idr_remove(&bsg_minor_idr, bcd->minor);
+ if (q->kobj.sd)
+ sysfs_remove_link(&q->kobj, "bsg");
+ device_unregister(bcd->class_dev);
+ bcd->class_dev = NULL;
+ kref_put(&bcd->ref, bsg_kref_release_function);
+ mutex_unlock(&bsg_mutex);
+}
+EXPORT_SYMBOL_GPL(bsg_unregister_queue);
+
+int bsg_register_queue(struct request_queue *q, struct device *parent,
+ const char *name, void (*release)(struct device *))
+{
+ struct bsg_class_device *bcd;
+ dev_t dev;
+ int ret;
+ struct device *class_dev = NULL;
+ const char *devname;
+
+ if (name)
+ devname = name;
+ else
+ devname = dev_name(parent);
+
+ /*
+ * we need a proper transport to send commands, not a stacked device
+ */
+ if (!queue_is_rq_based(q))
+ return 0;
+
+ bcd = &q->bsg_dev;
+ memset(bcd, 0, sizeof(*bcd));
+
+ mutex_lock(&bsg_mutex);
+
+ ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL);
+ if (ret < 0) {
+ if (ret == -ENOSPC) {
+ printk(KERN_ERR "bsg: too many bsg devices\n");
+ ret = -EINVAL;
+ }
+ goto unlock;
+ }
+
+ bcd->minor = ret;
+ bcd->queue = q;
+ bcd->parent = get_device(parent);
+ bcd->release = release;
+ kref_init(&bcd->ref);
+ dev = MKDEV(bsg_major, bcd->minor);
+ class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
+ if (IS_ERR(class_dev)) {
+ ret = PTR_ERR(class_dev);
+ goto put_dev;
+ }
+ bcd->class_dev = class_dev;
+
+ if (q->kobj.sd) {
+ ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
+ if (ret)
+ goto unregister_class_dev;
+ }
+
+ mutex_unlock(&bsg_mutex);
+ return 0;
+
+unregister_class_dev:
+ device_unregister(class_dev);
+put_dev:
+ put_device(parent);
+ idr_remove(&bsg_minor_idr, bcd->minor);
+unlock:
+ mutex_unlock(&bsg_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(bsg_register_queue);
+
+static struct cdev bsg_cdev;
+
+static char *bsg_devnode(struct device *dev, umode_t *mode)
+{
+ return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
+}
+
+static int __init bsg_init(void)
+{
+ int ret, i;
+ dev_t devid;
+
+ bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
+ sizeof(struct bsg_command), 0, 0, NULL);
+ if (!bsg_cmd_cachep) {
+ printk(KERN_ERR "bsg: failed creating slab cache\n");
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
+ INIT_HLIST_HEAD(&bsg_device_list[i]);
+
+ bsg_class = class_create(THIS_MODULE, "bsg");
+ if (IS_ERR(bsg_class)) {
+ ret = PTR_ERR(bsg_class);
+ goto destroy_kmemcache;
+ }
+ bsg_class->devnode = bsg_devnode;
+
+ ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
+ if (ret)
+ goto destroy_bsg_class;
+
+ bsg_major = MAJOR(devid);
+
+ cdev_init(&bsg_cdev, &bsg_fops);
+ ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
+ if (ret)
+ goto unregister_chrdev;
+
+ printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
+ " loaded (major %d)\n", bsg_major);
+ return 0;
+unregister_chrdev:
+ unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
+destroy_bsg_class:
+ class_destroy(bsg_class);
+destroy_kmemcache:
+ kmem_cache_destroy(bsg_cmd_cachep);
+ return ret;
+}
+
+MODULE_AUTHOR("Jens Axboe");
+MODULE_DESCRIPTION(BSG_DESCRIPTION);
+MODULE_LICENSE("GPL");
+
+device_initcall(bsg_init);
diff --git a/src/kernel/linux/v4.14/block/cfq-iosched.c b/src/kernel/linux/v4.14/block/cfq-iosched.c
new file mode 100644
index 0000000..9c4f1c4
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/cfq-iosched.c
@@ -0,0 +1,4915 @@
+/*
+ * CFQ, or complete fairness queueing, disk scheduler.
+ *
+ * Based on ideas from a previously unfinished io
+ * scheduler (round robin per-process disk scheduling) and Andrea Arcangeli.
+ *
+ * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
+ */
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sched/clock.h>
+#include <linux/blkdev.h>
+#include <linux/elevator.h>
+#include <linux/ktime.h>
+#include <linux/rbtree.h>
+#include <linux/ioprio.h>
+#include <linux/blktrace_api.h>
+#include <linux/blk-cgroup.h>
+#include "blk.h"
+#include "blk-wbt.h"
+
+/*
+ * tunables
+ */
+/* max queue in one round of service */
+static const int cfq_quantum = 8;
+static const u64 cfq_fifo_expire[2] = { NSEC_PER_SEC / 4, NSEC_PER_SEC / 8 };
+/* maximum backwards seek, in KiB */
+static const int cfq_back_max = 16 * 1024;
+/* penalty of a backwards seek */
+static const int cfq_back_penalty = 2;
+static const u64 cfq_slice_sync = NSEC_PER_SEC / 10;
+static u64 cfq_slice_async = NSEC_PER_SEC / 25;
+static const int cfq_slice_async_rq = 2;
+static u64 cfq_slice_idle = NSEC_PER_SEC / 125;
+static u64 cfq_group_idle = NSEC_PER_SEC / 125;
+static const u64 cfq_target_latency = (u64)NSEC_PER_SEC * 3/10; /* 300 ms */
+static const int cfq_hist_divisor = 4;
+
+/*
+ * offset from end of queue service tree for idle class
+ */
+#define CFQ_IDLE_DELAY (NSEC_PER_SEC / 5)
+/* offset from end of group service tree under time slice mode */
+#define CFQ_SLICE_MODE_GROUP_DELAY (NSEC_PER_SEC / 5)
+/* offset from end of group service under IOPS mode */
+#define CFQ_IOPS_MODE_GROUP_DELAY (HZ / 5)
+
+/*
+ * below this threshold, we consider thinktime immediate
+ */
+#define CFQ_MIN_TT (2 * NSEC_PER_SEC / HZ)
+
+#define CFQ_SLICE_SCALE (5)
+#define CFQ_HW_QUEUE_MIN (5)
+#define CFQ_SERVICE_SHIFT 12
+
+#define CFQQ_SEEK_THR (sector_t)(8 * 100)
+#define CFQQ_CLOSE_THR (sector_t)(8 * 1024)
+#define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32)
+#define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8)
+
+#define RQ_CIC(rq) icq_to_cic((rq)->elv.icq)
+#define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elv.priv[0])
+#define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elv.priv[1])
+
+static struct kmem_cache *cfq_pool;
+
+#define CFQ_PRIO_LISTS IOPRIO_BE_NR
+#define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
+#define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT)
+
+#define sample_valid(samples) ((samples) > 80)
+#define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node)
+
+/* blkio-related constants */
+#define CFQ_WEIGHT_LEGACY_MIN 10
+#define CFQ_WEIGHT_LEGACY_DFL 500
+#define CFQ_WEIGHT_LEGACY_MAX 1000
+
+struct cfq_ttime {
+ u64 last_end_request;
+
+ u64 ttime_total;
+ u64 ttime_mean;
+ unsigned long ttime_samples;
+};
+
+/*
+ * Most of our rbtree usage is for sorting with min extraction, so
+ * if we cache the leftmost node we don't have to walk down the tree
+ * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should
+ * move this into the elevator for the rq sorting as well.
+ */
+struct cfq_rb_root {
+ struct rb_root_cached rb;
+ struct rb_node *rb_rightmost;
+ unsigned count;
+ u64 min_vdisktime;
+ struct cfq_ttime ttime;
+};
+#define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT_CACHED, \
+ .rb_rightmost = NULL, \
+ .ttime = {.last_end_request = ktime_get_ns(),},}
+
+/*
+ * Per process-grouping structure
+ */
+struct cfq_queue {
+ /* reference count */
+ int ref;
+ /* various state flags, see below */
+ unsigned int flags;
+ /* parent cfq_data */
+ struct cfq_data *cfqd;
+ /* service_tree member */
+ struct rb_node rb_node;
+ /* service_tree key */
+ u64 rb_key;
+ /* prio tree member */
+ struct rb_node p_node;
+ /* prio tree root we belong to, if any */
+ struct rb_root *p_root;
+ /* sorted list of pending requests */
+ struct rb_root sort_list;
+ /* if fifo isn't expired, next request to serve */
+ struct request *next_rq;
+ /* requests queued in sort_list */
+ int queued[2];
+ /* currently allocated requests */
+ int allocated[2];
+ /* fifo list of requests in sort_list */
+ struct list_head fifo;
+
+ /* time when queue got scheduled in to dispatch first request. */
+ u64 dispatch_start;
+ u64 allocated_slice;
+ u64 slice_dispatch;
+ /* time when first request from queue completed and slice started. */
+ u64 slice_start;
+ u64 slice_end;
+ s64 slice_resid;
+
+ /* pending priority requests */
+ int prio_pending;
+ /* number of requests that are on the dispatch list or inside driver */
+ int dispatched;
+
+ /* io prio of this group */
+ unsigned short ioprio, org_ioprio;
+ unsigned short ioprio_class, org_ioprio_class;
+
+ pid_t pid;
+
+ u32 seek_history;
+ sector_t last_request_pos;
+
+ struct cfq_rb_root *service_tree;
+ struct cfq_queue *new_cfqq;
+ struct cfq_group *cfqg;
+ /* Number of sectors dispatched from queue in single dispatch round */
+ unsigned long nr_sectors;
+};
+
+/*
+ * First index in the service_trees.
+ * IDLE is handled separately, so it has negative index
+ */
+enum wl_class_t {
+ BE_WORKLOAD = 0,
+ RT_WORKLOAD = 1,
+ IDLE_WORKLOAD = 2,
+ CFQ_PRIO_NR,
+};
+
+/*
+ * Second index in the service_trees.
+ */
+enum wl_type_t {
+ ASYNC_WORKLOAD = 0,
+ SYNC_NOIDLE_WORKLOAD = 1,
+ SYNC_WORKLOAD = 2
+};
+
+struct cfqg_stats {
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ /* number of ios merged */
+ struct blkg_rwstat merged;
+ /* total time spent on device in ns, may not be accurate w/ queueing */
+ struct blkg_rwstat service_time;
+ /* total time spent waiting in scheduler queue in ns */
+ struct blkg_rwstat wait_time;
+ /* number of IOs queued up */
+ struct blkg_rwstat queued;
+ /* total disk time and nr sectors dispatched by this group */
+ struct blkg_stat time;
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ /* time not charged to this cgroup */
+ struct blkg_stat unaccounted_time;
+ /* sum of number of ios queued across all samples */
+ struct blkg_stat avg_queue_size_sum;
+ /* count of samples taken for average */
+ struct blkg_stat avg_queue_size_samples;
+ /* how many times this group has been removed from service tree */
+ struct blkg_stat dequeue;
+ /* total time spent waiting for it to be assigned a timeslice. */
+ struct blkg_stat group_wait_time;
+ /* time spent idling for this blkcg_gq */
+ struct blkg_stat idle_time;
+ /* total time with empty current active q with other requests queued */
+ struct blkg_stat empty_time;
+ /* fields after this shouldn't be cleared on stat reset */
+ uint64_t start_group_wait_time;
+ uint64_t start_idle_time;
+ uint64_t start_empty_time;
+ uint16_t flags;
+#endif /* CONFIG_DEBUG_BLK_CGROUP */
+#endif /* CONFIG_CFQ_GROUP_IOSCHED */
+};
+
+/* Per-cgroup data */
+struct cfq_group_data {
+ /* must be the first member */
+ struct blkcg_policy_data cpd;
+
+ unsigned int weight;
+ unsigned int leaf_weight;
+};
+
+/* This is per cgroup per device grouping structure */
+struct cfq_group {
+ /* must be the first member */
+ struct blkg_policy_data pd;
+
+ /* group service_tree member */
+ struct rb_node rb_node;
+
+ /* group service_tree key */
+ u64 vdisktime;
+
+ /*
+ * The number of active cfqgs and sum of their weights under this
+ * cfqg. This covers this cfqg's leaf_weight and all children's
+ * weights, but does not cover weights of further descendants.
+ *
+ * If a cfqg is on the service tree, it's active. An active cfqg
+ * also activates its parent and contributes to the children_weight
+ * of the parent.
+ */
+ int nr_active;
+ unsigned int children_weight;
+
+ /*
+ * vfraction is the fraction of vdisktime that the tasks in this
+ * cfqg are entitled to. This is determined by compounding the
+ * ratios walking up from this cfqg to the root.
+ *
+ * It is in fixed point w/ CFQ_SERVICE_SHIFT and the sum of all
+ * vfractions on a service tree is approximately 1. The sum may
+ * deviate a bit due to rounding errors and fluctuations caused by
+ * cfqgs entering and leaving the service tree.
+ */
+ unsigned int vfraction;
+
+ /*
+ * There are two weights - (internal) weight is the weight of this
+ * cfqg against the sibling cfqgs. leaf_weight is the wight of
+ * this cfqg against the child cfqgs. For the root cfqg, both
+ * weights are kept in sync for backward compatibility.
+ */
+ unsigned int weight;
+ unsigned int new_weight;
+ unsigned int dev_weight;
+
+ unsigned int leaf_weight;
+ unsigned int new_leaf_weight;
+ unsigned int dev_leaf_weight;
+
+ /* number of cfqq currently on this group */
+ int nr_cfqq;
+
+ /*
+ * Per group busy queues average. Useful for workload slice calc. We
+ * create the array for each prio class but at run time it is used
+ * only for RT and BE class and slot for IDLE class remains unused.
+ * This is primarily done to avoid confusion and a gcc warning.
+ */
+ unsigned int busy_queues_avg[CFQ_PRIO_NR];
+ /*
+ * rr lists of queues with requests. We maintain service trees for
+ * RT and BE classes. These trees are subdivided in subclasses
+ * of SYNC, SYNC_NOIDLE and ASYNC based on workload type. For IDLE
+ * class there is no subclassification and all the cfq queues go on
+ * a single tree service_tree_idle.
+ * Counts are embedded in the cfq_rb_root
+ */
+ struct cfq_rb_root service_trees[2][3];
+ struct cfq_rb_root service_tree_idle;
+
+ u64 saved_wl_slice;
+ enum wl_type_t saved_wl_type;
+ enum wl_class_t saved_wl_class;
+
+ /* number of requests that are on the dispatch list or inside driver */
+ int dispatched;
+ struct cfq_ttime ttime;
+ struct cfqg_stats stats; /* stats for this cfqg */
+
+ /* async queue for each priority case */
+ struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR];
+ struct cfq_queue *async_idle_cfqq;
+
+};
+
+struct cfq_io_cq {
+ struct io_cq icq; /* must be the first member */
+ struct cfq_queue *cfqq[2];
+ struct cfq_ttime ttime;
+ int ioprio; /* the current ioprio */
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ uint64_t blkcg_serial_nr; /* the current blkcg serial */
+#endif
+};
+
+/*
+ * Per block device queue structure
+ */
+struct cfq_data {
+ struct request_queue *queue;
+ /* Root service tree for cfq_groups */
+ struct cfq_rb_root grp_service_tree;
+ struct cfq_group *root_group;
+
+ /*
+ * The priority currently being served
+ */
+ enum wl_class_t serving_wl_class;
+ enum wl_type_t serving_wl_type;
+ u64 workload_expires;
+ struct cfq_group *serving_group;
+
+ /*
+ * Each priority tree is sorted by next_request position. These
+ * trees are used when determining if two or more queues are
+ * interleaving requests (see cfq_close_cooperator).
+ */
+ struct rb_root prio_trees[CFQ_PRIO_LISTS];
+
+ unsigned int busy_queues;
+ unsigned int busy_sync_queues;
+
+ int rq_in_driver;
+ int rq_in_flight[2];
+
+ /*
+ * queue-depth detection
+ */
+ int rq_queued;
+ int hw_tag;
+ /*
+ * hw_tag can be
+ * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection)
+ * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth)
+ * 0 => no NCQ
+ */
+ int hw_tag_est_depth;
+ unsigned int hw_tag_samples;
+
+ /*
+ * idle window management
+ */
+ struct hrtimer idle_slice_timer;
+ struct work_struct unplug_work;
+
+ struct cfq_queue *active_queue;
+ struct cfq_io_cq *active_cic;
+
+ sector_t last_position;
+
+ /*
+ * tunables, see top of file
+ */
+ unsigned int cfq_quantum;
+ unsigned int cfq_back_penalty;
+ unsigned int cfq_back_max;
+ unsigned int cfq_slice_async_rq;
+ unsigned int cfq_latency;
+ u64 cfq_fifo_expire[2];
+ u64 cfq_slice[2];
+ u64 cfq_slice_idle;
+ u64 cfq_group_idle;
+ u64 cfq_target_latency;
+
+ /*
+ * Fallback dummy cfqq for extreme OOM conditions
+ */
+ struct cfq_queue oom_cfqq;
+
+ u64 last_delayed_sync;
+};
+
+static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd);
+static void cfq_put_queue(struct cfq_queue *cfqq);
+
+static struct cfq_rb_root *st_for(struct cfq_group *cfqg,
+ enum wl_class_t class,
+ enum wl_type_t type)
+{
+ if (!cfqg)
+ return NULL;
+
+ if (class == IDLE_WORKLOAD)
+ return &cfqg->service_tree_idle;
+
+ return &cfqg->service_trees[class][type];
+}
+
+enum cfqq_state_flags {
+ CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */
+ CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */
+ CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */
+ CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */
+ CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */
+ CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */
+ CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */
+ CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */
+ CFQ_CFQQ_FLAG_sync, /* synchronous queue */
+ CFQ_CFQQ_FLAG_coop, /* cfqq is shared */
+ CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */
+ CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */
+ CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */
+};
+
+#define CFQ_CFQQ_FNS(name) \
+static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \
+{ \
+ (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \
+} \
+static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \
+{ \
+ (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \
+} \
+static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \
+{ \
+ return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \
+}
+
+CFQ_CFQQ_FNS(on_rr);
+CFQ_CFQQ_FNS(wait_request);
+CFQ_CFQQ_FNS(must_dispatch);
+CFQ_CFQQ_FNS(must_alloc_slice);
+CFQ_CFQQ_FNS(fifo_expire);
+CFQ_CFQQ_FNS(idle_window);
+CFQ_CFQQ_FNS(prio_changed);
+CFQ_CFQQ_FNS(slice_new);
+CFQ_CFQQ_FNS(sync);
+CFQ_CFQQ_FNS(coop);
+CFQ_CFQQ_FNS(split_coop);
+CFQ_CFQQ_FNS(deep);
+CFQ_CFQQ_FNS(wait_busy);
+#undef CFQ_CFQQ_FNS
+
+#if defined(CONFIG_CFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)
+
+/* cfqg stats flags */
+enum cfqg_stats_flags {
+ CFQG_stats_waiting = 0,
+ CFQG_stats_idling,
+ CFQG_stats_empty,
+};
+
+#define CFQG_FLAG_FNS(name) \
+static inline void cfqg_stats_mark_##name(struct cfqg_stats *stats) \
+{ \
+ stats->flags |= (1 << CFQG_stats_##name); \
+} \
+static inline void cfqg_stats_clear_##name(struct cfqg_stats *stats) \
+{ \
+ stats->flags &= ~(1 << CFQG_stats_##name); \
+} \
+static inline int cfqg_stats_##name(struct cfqg_stats *stats) \
+{ \
+ return (stats->flags & (1 << CFQG_stats_##name)) != 0; \
+} \
+
+CFQG_FLAG_FNS(waiting)
+CFQG_FLAG_FNS(idling)
+CFQG_FLAG_FNS(empty)
+#undef CFQG_FLAG_FNS
+
+/* This should be called with the queue_lock held. */
+static void cfqg_stats_update_group_wait_time(struct cfqg_stats *stats)
+{
+ unsigned long long now;
+
+ if (!cfqg_stats_waiting(stats))
+ return;
+
+ now = sched_clock();
+ if (time_after64(now, stats->start_group_wait_time))
+ blkg_stat_add(&stats->group_wait_time,
+ now - stats->start_group_wait_time);
+ cfqg_stats_clear_waiting(stats);
+}
+
+/* This should be called with the queue_lock held. */
+static void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg,
+ struct cfq_group *curr_cfqg)
+{
+ struct cfqg_stats *stats = &cfqg->stats;
+
+ if (cfqg_stats_waiting(stats))
+ return;
+ if (cfqg == curr_cfqg)
+ return;
+ stats->start_group_wait_time = sched_clock();
+ cfqg_stats_mark_waiting(stats);
+}
+
+/* This should be called with the queue_lock held. */
+static void cfqg_stats_end_empty_time(struct cfqg_stats *stats)
+{
+ unsigned long long now;
+
+ if (!cfqg_stats_empty(stats))
+ return;
+
+ now = sched_clock();
+ if (time_after64(now, stats->start_empty_time))
+ blkg_stat_add(&stats->empty_time,
+ now - stats->start_empty_time);
+ cfqg_stats_clear_empty(stats);
+}
+
+static void cfqg_stats_update_dequeue(struct cfq_group *cfqg)
+{
+ blkg_stat_add(&cfqg->stats.dequeue, 1);
+}
+
+static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg)
+{
+ struct cfqg_stats *stats = &cfqg->stats;
+
+ if (blkg_rwstat_total(&stats->queued))
+ return;
+
+ /*
+ * group is already marked empty. This can happen if cfqq got new
+ * request in parent group and moved to this group while being added
+ * to service tree. Just ignore the event and move on.
+ */
+ if (cfqg_stats_empty(stats))
+ return;
+
+ stats->start_empty_time = sched_clock();
+ cfqg_stats_mark_empty(stats);
+}
+
+static void cfqg_stats_update_idle_time(struct cfq_group *cfqg)
+{
+ struct cfqg_stats *stats = &cfqg->stats;
+
+ if (cfqg_stats_idling(stats)) {
+ unsigned long long now = sched_clock();
+
+ if (time_after64(now, stats->start_idle_time))
+ blkg_stat_add(&stats->idle_time,
+ now - stats->start_idle_time);
+ cfqg_stats_clear_idling(stats);
+ }
+}
+
+static void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg)
+{
+ struct cfqg_stats *stats = &cfqg->stats;
+
+ BUG_ON(cfqg_stats_idling(stats));
+
+ stats->start_idle_time = sched_clock();
+ cfqg_stats_mark_idling(stats);
+}
+
+static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg)
+{
+ struct cfqg_stats *stats = &cfqg->stats;
+
+ blkg_stat_add(&stats->avg_queue_size_sum,
+ blkg_rwstat_total(&stats->queued));
+ blkg_stat_add(&stats->avg_queue_size_samples, 1);
+ cfqg_stats_update_group_wait_time(stats);
+}
+
+#else /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */
+
+static inline void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, struct cfq_group *curr_cfqg) { }
+static inline void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { }
+static inline void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { }
+static inline void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { }
+static inline void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { }
+static inline void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { }
+static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { }
+
+#endif /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */
+
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+
+static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd)
+{
+ return pd ? container_of(pd, struct cfq_group, pd) : NULL;
+}
+
+static struct cfq_group_data
+*cpd_to_cfqgd(struct blkcg_policy_data *cpd)
+{
+ return cpd ? container_of(cpd, struct cfq_group_data, cpd) : NULL;
+}
+
+static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg)
+{
+ return pd_to_blkg(&cfqg->pd);
+}
+
+static struct blkcg_policy blkcg_policy_cfq;
+
+static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg)
+{
+ return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq));
+}
+
+static struct cfq_group_data *blkcg_to_cfqgd(struct blkcg *blkcg)
+{
+ return cpd_to_cfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_cfq));
+}
+
+static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg)
+{
+ struct blkcg_gq *pblkg = cfqg_to_blkg(cfqg)->parent;
+
+ return pblkg ? blkg_to_cfqg(pblkg) : NULL;
+}
+
+static inline bool cfqg_is_descendant(struct cfq_group *cfqg,
+ struct cfq_group *ancestor)
+{
+ return cgroup_is_descendant(cfqg_to_blkg(cfqg)->blkcg->css.cgroup,
+ cfqg_to_blkg(ancestor)->blkcg->css.cgroup);
+}
+
+static inline void cfqg_get(struct cfq_group *cfqg)
+{
+ return blkg_get(cfqg_to_blkg(cfqg));
+}
+
+static inline void cfqg_put(struct cfq_group *cfqg)
+{
+ return blkg_put(cfqg_to_blkg(cfqg));
+}
+
+#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) do { \
+ blk_add_cgroup_trace_msg((cfqd)->queue, \
+ cfqg_to_blkg((cfqq)->cfqg)->blkcg, \
+ "cfq%d%c%c " fmt, (cfqq)->pid, \
+ cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
+ cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\
+ ##args); \
+} while (0)
+
+#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do { \
+ blk_add_cgroup_trace_msg((cfqd)->queue, \
+ cfqg_to_blkg(cfqg)->blkcg, fmt, ##args); \
+} while (0)
+
+static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
+ struct cfq_group *curr_cfqg,
+ unsigned int op)
+{
+ blkg_rwstat_add(&cfqg->stats.queued, op, 1);
+ cfqg_stats_end_empty_time(&cfqg->stats);
+ cfqg_stats_set_start_group_wait_time(cfqg, curr_cfqg);
+}
+
+static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg,
+ uint64_t time, unsigned long unaccounted_time)
+{
+ blkg_stat_add(&cfqg->stats.time, time);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ blkg_stat_add(&cfqg->stats.unaccounted_time, unaccounted_time);
+#endif
+}
+
+static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg,
+ unsigned int op)
+{
+ blkg_rwstat_add(&cfqg->stats.queued, op, -1);
+}
+
+static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg,
+ unsigned int op)
+{
+ blkg_rwstat_add(&cfqg->stats.merged, op, 1);
+}
+
+static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
+ uint64_t start_time, uint64_t io_start_time,
+ unsigned int op)
+{
+ struct cfqg_stats *stats = &cfqg->stats;
+ unsigned long long now = sched_clock();
+
+ if (time_after64(now, io_start_time))
+ blkg_rwstat_add(&stats->service_time, op, now - io_start_time);
+ if (time_after64(io_start_time, start_time))
+ blkg_rwstat_add(&stats->wait_time, op,
+ io_start_time - start_time);
+}
+
+/* @stats = 0 */
+static void cfqg_stats_reset(struct cfqg_stats *stats)
+{
+ /* queued stats shouldn't be cleared */
+ blkg_rwstat_reset(&stats->merged);
+ blkg_rwstat_reset(&stats->service_time);
+ blkg_rwstat_reset(&stats->wait_time);
+ blkg_stat_reset(&stats->time);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ blkg_stat_reset(&stats->unaccounted_time);
+ blkg_stat_reset(&stats->avg_queue_size_sum);
+ blkg_stat_reset(&stats->avg_queue_size_samples);
+ blkg_stat_reset(&stats->dequeue);
+ blkg_stat_reset(&stats->group_wait_time);
+ blkg_stat_reset(&stats->idle_time);
+ blkg_stat_reset(&stats->empty_time);
+#endif
+}
+
+/* @to += @from */
+static void cfqg_stats_add_aux(struct cfqg_stats *to, struct cfqg_stats *from)
+{
+ /* queued stats shouldn't be cleared */
+ blkg_rwstat_add_aux(&to->merged, &from->merged);
+ blkg_rwstat_add_aux(&to->service_time, &from->service_time);
+ blkg_rwstat_add_aux(&to->wait_time, &from->wait_time);
+ blkg_stat_add_aux(&from->time, &from->time);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ blkg_stat_add_aux(&to->unaccounted_time, &from->unaccounted_time);
+ blkg_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
+ blkg_stat_add_aux(&to->avg_queue_size_samples, &from->avg_queue_size_samples);
+ blkg_stat_add_aux(&to->dequeue, &from->dequeue);
+ blkg_stat_add_aux(&to->group_wait_time, &from->group_wait_time);
+ blkg_stat_add_aux(&to->idle_time, &from->idle_time);
+ blkg_stat_add_aux(&to->empty_time, &from->empty_time);
+#endif
+}
+
+/*
+ * Transfer @cfqg's stats to its parent's aux counts so that the ancestors'
+ * recursive stats can still account for the amount used by this cfqg after
+ * it's gone.
+ */
+static void cfqg_stats_xfer_dead(struct cfq_group *cfqg)
+{
+ struct cfq_group *parent = cfqg_parent(cfqg);
+
+ lockdep_assert_held(cfqg_to_blkg(cfqg)->q->queue_lock);
+
+ if (unlikely(!parent))
+ return;
+
+ cfqg_stats_add_aux(&parent->stats, &cfqg->stats);
+ cfqg_stats_reset(&cfqg->stats);
+}
+
+#else /* CONFIG_CFQ_GROUP_IOSCHED */
+
+static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; }
+static inline bool cfqg_is_descendant(struct cfq_group *cfqg,
+ struct cfq_group *ancestor)
+{
+ return true;
+}
+static inline void cfqg_get(struct cfq_group *cfqg) { }
+static inline void cfqg_put(struct cfq_group *cfqg) { }
+
+#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
+ blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c " fmt, (cfqq)->pid, \
+ cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
+ cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\
+ ##args)
+#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0)
+
+static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
+ struct cfq_group *curr_cfqg, unsigned int op) { }
+static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg,
+ uint64_t time, unsigned long unaccounted_time) { }
+static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg,
+ unsigned int op) { }
+static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg,
+ unsigned int op) { }
+static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
+ uint64_t start_time, uint64_t io_start_time,
+ unsigned int op) { }
+
+#endif /* CONFIG_CFQ_GROUP_IOSCHED */
+
+#define cfq_log(cfqd, fmt, args...) \
+ blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args)
+
+/* Traverses through cfq group service trees */
+#define for_each_cfqg_st(cfqg, i, j, st) \
+ for (i = 0; i <= IDLE_WORKLOAD; i++) \
+ for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\
+ : &cfqg->service_tree_idle; \
+ (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \
+ (i == IDLE_WORKLOAD && j == 0); \
+ j++, st = i < IDLE_WORKLOAD ? \
+ &cfqg->service_trees[i][j]: NULL) \
+
+static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd,
+ struct cfq_ttime *ttime, bool group_idle)
+{
+ u64 slice;
+ if (!sample_valid(ttime->ttime_samples))
+ return false;
+ if (group_idle)
+ slice = cfqd->cfq_group_idle;
+ else
+ slice = cfqd->cfq_slice_idle;
+ return ttime->ttime_mean > slice;
+}
+
+static inline bool iops_mode(struct cfq_data *cfqd)
+{
+ /*
+ * If we are not idling on queues and it is a NCQ drive, parallel
+ * execution of requests is on and measuring time is not possible
+ * in most of the cases until and unless we drive shallower queue
+ * depths and that becomes a performance bottleneck. In such cases
+ * switch to start providing fairness in terms of number of IOs.
+ */
+ if (!cfqd->cfq_slice_idle && cfqd->hw_tag)
+ return true;
+ else
+ return false;
+}
+
+static inline enum wl_class_t cfqq_class(struct cfq_queue *cfqq)
+{
+ if (cfq_class_idle(cfqq))
+ return IDLE_WORKLOAD;
+ if (cfq_class_rt(cfqq))
+ return RT_WORKLOAD;
+ return BE_WORKLOAD;
+}
+
+
+static enum wl_type_t cfqq_type(struct cfq_queue *cfqq)
+{
+ if (!cfq_cfqq_sync(cfqq))
+ return ASYNC_WORKLOAD;
+ if (!cfq_cfqq_idle_window(cfqq))
+ return SYNC_NOIDLE_WORKLOAD;
+ return SYNC_WORKLOAD;
+}
+
+static inline int cfq_group_busy_queues_wl(enum wl_class_t wl_class,
+ struct cfq_data *cfqd,
+ struct cfq_group *cfqg)
+{
+ if (wl_class == IDLE_WORKLOAD)
+ return cfqg->service_tree_idle.count;
+
+ return cfqg->service_trees[wl_class][ASYNC_WORKLOAD].count +
+ cfqg->service_trees[wl_class][SYNC_NOIDLE_WORKLOAD].count +
+ cfqg->service_trees[wl_class][SYNC_WORKLOAD].count;
+}
+
+static inline int cfqg_busy_async_queues(struct cfq_data *cfqd,
+ struct cfq_group *cfqg)
+{
+ return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count +
+ cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count;
+}
+
+static void cfq_dispatch_insert(struct request_queue *, struct request *);
+static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, bool is_sync,
+ struct cfq_io_cq *cic, struct bio *bio);
+
+static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq)
+{
+ /* cic->icq is the first member, %NULL will convert to %NULL */
+ return container_of(icq, struct cfq_io_cq, icq);
+}
+
+static inline struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *cfqd,
+ struct io_context *ioc)
+{
+ if (ioc)
+ return icq_to_cic(ioc_lookup_icq(ioc, cfqd->queue));
+ return NULL;
+}
+
+static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync)
+{
+ return cic->cfqq[is_sync];
+}
+
+static inline void cic_set_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq,
+ bool is_sync)
+{
+ cic->cfqq[is_sync] = cfqq;
+}
+
+static inline struct cfq_data *cic_to_cfqd(struct cfq_io_cq *cic)
+{
+ return cic->icq.q->elevator->elevator_data;
+}
+
+/*
+ * scheduler run of queue, if there are requests pending and no one in the
+ * driver that will restart queueing
+ */
+static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
+{
+ if (cfqd->busy_queues) {
+ cfq_log(cfqd, "schedule dispatch");
+ kblockd_schedule_work(&cfqd->unplug_work);
+ }
+}
+
+/*
+ * Scale schedule slice based on io priority. Use the sync time slice only
+ * if a queue is marked sync and has sync io queued. A sync queue with async
+ * io only, should not get full sync slice length.
+ */
+static inline u64 cfq_prio_slice(struct cfq_data *cfqd, bool sync,
+ unsigned short prio)
+{
+ u64 base_slice = cfqd->cfq_slice[sync];
+ u64 slice = div_u64(base_slice, CFQ_SLICE_SCALE);
+
+ WARN_ON(prio >= IOPRIO_BE_NR);
+
+ return base_slice + (slice * (4 - prio));
+}
+
+static inline u64
+cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio);
+}
+
+/**
+ * cfqg_scale_charge - scale disk time charge according to cfqg weight
+ * @charge: disk time being charged
+ * @vfraction: vfraction of the cfqg, fixed point w/ CFQ_SERVICE_SHIFT
+ *
+ * Scale @charge according to @vfraction, which is in range (0, 1]. The
+ * scaling is inversely proportional.
+ *
+ * scaled = charge / vfraction
+ *
+ * The result is also in fixed point w/ CFQ_SERVICE_SHIFT.
+ */
+static inline u64 cfqg_scale_charge(u64 charge,
+ unsigned int vfraction)
+{
+ u64 c = charge << CFQ_SERVICE_SHIFT; /* make it fixed point */
+
+ /* charge / vfraction */
+ c <<= CFQ_SERVICE_SHIFT;
+ return div_u64(c, vfraction);
+}
+
+static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime)
+{
+ s64 delta = (s64)(vdisktime - min_vdisktime);
+ if (delta > 0)
+ min_vdisktime = vdisktime;
+
+ return min_vdisktime;
+}
+
+static void update_min_vdisktime(struct cfq_rb_root *st)
+{
+ if (!RB_EMPTY_ROOT(&st->rb.rb_root)) {
+ struct cfq_group *cfqg = rb_entry_cfqg(st->rb.rb_leftmost);
+
+ st->min_vdisktime = max_vdisktime(st->min_vdisktime,
+ cfqg->vdisktime);
+ }
+}
+
+/*
+ * get averaged number of queues of RT/BE priority.
+ * average is updated, with a formula that gives more weight to higher numbers,
+ * to quickly follows sudden increases and decrease slowly
+ */
+
+static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd,
+ struct cfq_group *cfqg, bool rt)
+{
+ unsigned min_q, max_q;
+ unsigned mult = cfq_hist_divisor - 1;
+ unsigned round = cfq_hist_divisor / 2;
+ unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg);
+
+ min_q = min(cfqg->busy_queues_avg[rt], busy);
+ max_q = max(cfqg->busy_queues_avg[rt], busy);
+ cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) /
+ cfq_hist_divisor;
+ return cfqg->busy_queues_avg[rt];
+}
+
+static inline u64
+cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg)
+{
+ return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT;
+}
+
+static inline u64
+cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ u64 slice = cfq_prio_to_slice(cfqd, cfqq);
+ if (cfqd->cfq_latency) {
+ /*
+ * interested queues (we consider only the ones with the same
+ * priority class in the cfq group)
+ */
+ unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg,
+ cfq_class_rt(cfqq));
+ u64 sync_slice = cfqd->cfq_slice[1];
+ u64 expect_latency = sync_slice * iq;
+ u64 group_slice = cfq_group_slice(cfqd, cfqq->cfqg);
+
+ if (expect_latency > group_slice) {
+ u64 base_low_slice = 2 * cfqd->cfq_slice_idle;
+ u64 low_slice;
+
+ /* scale low_slice according to IO priority
+ * and sync vs async */
+ low_slice = div64_u64(base_low_slice*slice, sync_slice);
+ low_slice = min(slice, low_slice);
+ /* the adapted slice value is scaled to fit all iqs
+ * into the target latency */
+ slice = div64_u64(slice*group_slice, expect_latency);
+ slice = max(slice, low_slice);
+ }
+ }
+ return slice;
+}
+
+static inline void
+cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ u64 slice = cfq_scaled_cfqq_slice(cfqd, cfqq);
+ u64 now = ktime_get_ns();
+
+ cfqq->slice_start = now;
+ cfqq->slice_end = now + slice;
+ cfqq->allocated_slice = slice;
+ cfq_log_cfqq(cfqd, cfqq, "set_slice=%llu", cfqq->slice_end - now);
+}
+
+/*
+ * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end
+ * isn't valid until the first request from the dispatch is activated
+ * and the slice time set.
+ */
+static inline bool cfq_slice_used(struct cfq_queue *cfqq)
+{
+ if (cfq_cfqq_slice_new(cfqq))
+ return false;
+ if (ktime_get_ns() < cfqq->slice_end)
+ return false;
+
+ return true;
+}
+
+/*
+ * Lifted from AS - choose which of rq1 and rq2 that is best served now.
+ * We choose the request that is closest to the head right now. Distance
+ * behind the head is penalized and only allowed to a certain extent.
+ */
+static struct request *
+cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last)
+{
+ sector_t s1, s2, d1 = 0, d2 = 0;
+ unsigned long back_max;
+#define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */
+#define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */
+ unsigned wrap = 0; /* bit mask: requests behind the disk head? */
+
+ if (rq1 == NULL || rq1 == rq2)
+ return rq2;
+ if (rq2 == NULL)
+ return rq1;
+
+ if (rq_is_sync(rq1) != rq_is_sync(rq2))
+ return rq_is_sync(rq1) ? rq1 : rq2;
+
+ if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO)
+ return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2;
+
+ s1 = blk_rq_pos(rq1);
+ s2 = blk_rq_pos(rq2);
+
+ /*
+ * by definition, 1KiB is 2 sectors
+ */
+ back_max = cfqd->cfq_back_max * 2;
+
+ /*
+ * Strict one way elevator _except_ in the case where we allow
+ * short backward seeks which are biased as twice the cost of a
+ * similar forward seek.
+ */
+ if (s1 >= last)
+ d1 = s1 - last;
+ else if (s1 + back_max >= last)
+ d1 = (last - s1) * cfqd->cfq_back_penalty;
+ else
+ wrap |= CFQ_RQ1_WRAP;
+
+ if (s2 >= last)
+ d2 = s2 - last;
+ else if (s2 + back_max >= last)
+ d2 = (last - s2) * cfqd->cfq_back_penalty;
+ else
+ wrap |= CFQ_RQ2_WRAP;
+
+ /* Found required data */
+
+ /*
+ * By doing switch() on the bit mask "wrap" we avoid having to
+ * check two variables for all permutations: --> faster!
+ */
+ switch (wrap) {
+ case 0: /* common case for CFQ: rq1 and rq2 not wrapped */
+ if (d1 < d2)
+ return rq1;
+ else if (d2 < d1)
+ return rq2;
+ else {
+ if (s1 >= s2)
+ return rq1;
+ else
+ return rq2;
+ }
+
+ case CFQ_RQ2_WRAP:
+ return rq1;
+ case CFQ_RQ1_WRAP:
+ return rq2;
+ case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */
+ default:
+ /*
+ * Since both rqs are wrapped,
+ * start with the one that's further behind head
+ * (--> only *one* back seek required),
+ * since back seek takes more time than forward.
+ */
+ if (s1 <= s2)
+ return rq1;
+ else
+ return rq2;
+ }
+}
+
+static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
+{
+ /* Service tree is empty */
+ if (!root->count)
+ return NULL;
+
+ return rb_entry(rb_first_cached(&root->rb), struct cfq_queue, rb_node);
+}
+
+static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root)
+{
+ return rb_entry_cfqg(rb_first_cached(&root->rb));
+}
+
+static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root)
+{
+ if (root->rb_rightmost == n)
+ root->rb_rightmost = rb_prev(n);
+
+ rb_erase_cached(n, &root->rb);
+ RB_CLEAR_NODE(n);
+
+ --root->count;
+}
+
+/*
+ * would be nice to take fifo expire time into account as well
+ */
+static struct request *
+cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ struct request *last)
+{
+ struct rb_node *rbnext = rb_next(&last->rb_node);
+ struct rb_node *rbprev = rb_prev(&last->rb_node);
+ struct request *next = NULL, *prev = NULL;
+
+ BUG_ON(RB_EMPTY_NODE(&last->rb_node));
+
+ if (rbprev)
+ prev = rb_entry_rq(rbprev);
+
+ if (rbnext)
+ next = rb_entry_rq(rbnext);
+ else {
+ rbnext = rb_first(&cfqq->sort_list);
+ if (rbnext && rbnext != &last->rb_node)
+ next = rb_entry_rq(rbnext);
+ }
+
+ return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last));
+}
+
+static u64 cfq_slice_offset(struct cfq_data *cfqd,
+ struct cfq_queue *cfqq)
+{
+ /*
+ * just an approximation, should be ok.
+ */
+ return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) -
+ cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio));
+}
+
+static inline s64
+cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg)
+{
+ return cfqg->vdisktime - st->min_vdisktime;
+}
+
+static void
+__cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
+{
+ struct rb_node **node = &st->rb.rb_root.rb_node;
+ struct rb_node *parent = NULL;
+ struct cfq_group *__cfqg;
+ s64 key = cfqg_key(st, cfqg);
+ bool leftmost = true, rightmost = true;
+
+ while (*node != NULL) {
+ parent = *node;
+ __cfqg = rb_entry_cfqg(parent);
+
+ if (key < cfqg_key(st, __cfqg)) {
+ node = &parent->rb_left;
+ rightmost = false;
+ } else {
+ node = &parent->rb_right;
+ leftmost = false;
+ }
+ }
+
+ if (rightmost)
+ st->rb_rightmost = &cfqg->rb_node;
+
+ rb_link_node(&cfqg->rb_node, parent, node);
+ rb_insert_color_cached(&cfqg->rb_node, &st->rb, leftmost);
+}
+
+/*
+ * This has to be called only on activation of cfqg
+ */
+static void
+cfq_update_group_weight(struct cfq_group *cfqg)
+{
+ if (cfqg->new_weight) {
+ cfqg->weight = cfqg->new_weight;
+ cfqg->new_weight = 0;
+ }
+}
+
+static void
+cfq_update_group_leaf_weight(struct cfq_group *cfqg)
+{
+ BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));
+
+ if (cfqg->new_leaf_weight) {
+ cfqg->leaf_weight = cfqg->new_leaf_weight;
+ cfqg->new_leaf_weight = 0;
+ }
+}
+
+static void
+cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
+{
+ unsigned int vfr = 1 << CFQ_SERVICE_SHIFT; /* start with 1 */
+ struct cfq_group *pos = cfqg;
+ struct cfq_group *parent;
+ bool propagate;
+
+ /* add to the service tree */
+ BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));
+
+ /*
+ * Update leaf_weight. We cannot update weight at this point
+ * because cfqg might already have been activated and is
+ * contributing its current weight to the parent's child_weight.
+ */
+ cfq_update_group_leaf_weight(cfqg);
+ __cfq_group_service_tree_add(st, cfqg);
+
+ /*
+ * Activate @cfqg and calculate the portion of vfraction @cfqg is
+ * entitled to. vfraction is calculated by walking the tree
+ * towards the root calculating the fraction it has at each level.
+ * The compounded ratio is how much vfraction @cfqg owns.
+ *
+ * Start with the proportion tasks in this cfqg has against active
+ * children cfqgs - its leaf_weight against children_weight.
+ */
+ propagate = !pos->nr_active++;
+ pos->children_weight += pos->leaf_weight;
+ vfr = vfr * pos->leaf_weight / pos->children_weight;
+
+ /*
+ * Compound ->weight walking up the tree. Both activation and
+ * vfraction calculation are done in the same loop. Propagation
+ * stops once an already activated node is met. vfraction
+ * calculation should always continue to the root.
+ */
+ while ((parent = cfqg_parent(pos))) {
+ if (propagate) {
+ cfq_update_group_weight(pos);
+ propagate = !parent->nr_active++;
+ parent->children_weight += pos->weight;
+ }
+ vfr = vfr * pos->weight / parent->children_weight;
+ pos = parent;
+ }
+
+ cfqg->vfraction = max_t(unsigned, vfr, 1);
+}
+
+static inline u64 cfq_get_cfqg_vdisktime_delay(struct cfq_data *cfqd)
+{
+ if (!iops_mode(cfqd))
+ return CFQ_SLICE_MODE_GROUP_DELAY;
+ else
+ return CFQ_IOPS_MODE_GROUP_DELAY;
+}
+
+static void
+cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
+{
+ struct cfq_rb_root *st = &cfqd->grp_service_tree;
+ struct cfq_group *__cfqg;
+ struct rb_node *n;
+
+ cfqg->nr_cfqq++;
+ if (!RB_EMPTY_NODE(&cfqg->rb_node))
+ return;
+
+ /*
+ * Currently put the group at the end. Later implement something
+ * so that groups get lesser vtime based on their weights, so that
+ * if group does not loose all if it was not continuously backlogged.
+ */
+ n = st->rb_rightmost;
+ if (n) {
+ __cfqg = rb_entry_cfqg(n);
+ cfqg->vdisktime = __cfqg->vdisktime +
+ cfq_get_cfqg_vdisktime_delay(cfqd);
+ } else
+ cfqg->vdisktime = st->min_vdisktime;
+ cfq_group_service_tree_add(st, cfqg);
+}
+
+static void
+cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg)
+{
+ struct cfq_group *pos = cfqg;
+ bool propagate;
+
+ /*
+ * Undo activation from cfq_group_service_tree_add(). Deactivate
+ * @cfqg and propagate deactivation upwards.
+ */
+ propagate = !--pos->nr_active;
+ pos->children_weight -= pos->leaf_weight;
+
+ while (propagate) {
+ struct cfq_group *parent = cfqg_parent(pos);
+
+ /* @pos has 0 nr_active at this point */
+ WARN_ON_ONCE(pos->children_weight);
+ pos->vfraction = 0;
+
+ if (!parent)
+ break;
+
+ propagate = !--parent->nr_active;
+ parent->children_weight -= pos->weight;
+ pos = parent;
+ }
+
+ /* remove from the service tree */
+ if (!RB_EMPTY_NODE(&cfqg->rb_node))
+ cfq_rb_erase(&cfqg->rb_node, st);
+}
+
+static void
+cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
+{
+ struct cfq_rb_root *st = &cfqd->grp_service_tree;
+
+ BUG_ON(cfqg->nr_cfqq < 1);
+ cfqg->nr_cfqq--;
+
+ /* If there are other cfq queues under this group, don't delete it */
+ if (cfqg->nr_cfqq)
+ return;
+
+ cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
+ cfq_group_service_tree_del(st, cfqg);
+ cfqg->saved_wl_slice = 0;
+ cfqg_stats_update_dequeue(cfqg);
+}
+
+static inline u64 cfq_cfqq_slice_usage(struct cfq_queue *cfqq,
+ u64 *unaccounted_time)
+{
+ u64 slice_used;
+ u64 now = ktime_get_ns();
+
+ /*
+ * Queue got expired before even a single request completed or
+ * got expired immediately after first request completion.
+ */
+ if (!cfqq->slice_start || cfqq->slice_start == now) {
+ /*
+ * Also charge the seek time incurred to the group, otherwise
+ * if there are mutiple queues in the group, each can dispatch
+ * a single request on seeky media and cause lots of seek time
+ * and group will never know it.
+ */
+ slice_used = max_t(u64, (now - cfqq->dispatch_start),
+ jiffies_to_nsecs(1));
+ } else {
+ slice_used = now - cfqq->slice_start;
+ if (slice_used > cfqq->allocated_slice) {
+ *unaccounted_time = slice_used - cfqq->allocated_slice;
+ slice_used = cfqq->allocated_slice;
+ }
+ if (cfqq->slice_start > cfqq->dispatch_start)
+ *unaccounted_time += cfqq->slice_start -
+ cfqq->dispatch_start;
+ }
+
+ return slice_used;
+}
+
+static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
+ struct cfq_queue *cfqq)
+{
+ struct cfq_rb_root *st = &cfqd->grp_service_tree;
+ u64 used_sl, charge, unaccounted_sl = 0;
+ int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg)
+ - cfqg->service_tree_idle.count;
+ unsigned int vfr;
+ u64 now = ktime_get_ns();
+
+ BUG_ON(nr_sync < 0);
+ used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl);
+
+ if (iops_mode(cfqd))
+ charge = cfqq->slice_dispatch;
+ else if (!cfq_cfqq_sync(cfqq) && !nr_sync)
+ charge = cfqq->allocated_slice;
+
+ /*
+ * Can't update vdisktime while on service tree and cfqg->vfraction
+ * is valid only while on it. Cache vfr, leave the service tree,
+ * update vdisktime and go back on. The re-addition to the tree
+ * will also update the weights as necessary.
+ */
+ vfr = cfqg->vfraction;
+ cfq_group_service_tree_del(st, cfqg);
+ cfqg->vdisktime += cfqg_scale_charge(charge, vfr);
+ cfq_group_service_tree_add(st, cfqg);
+
+ /* This group is being expired. Save the context */
+ if (cfqd->workload_expires > now) {
+ cfqg->saved_wl_slice = cfqd->workload_expires - now;
+ cfqg->saved_wl_type = cfqd->serving_wl_type;
+ cfqg->saved_wl_class = cfqd->serving_wl_class;
+ } else
+ cfqg->saved_wl_slice = 0;
+
+ cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
+ st->min_vdisktime);
+ cfq_log_cfqq(cfqq->cfqd, cfqq,
+ "sl_used=%llu disp=%llu charge=%llu iops=%u sect=%lu",
+ used_sl, cfqq->slice_dispatch, charge,
+ iops_mode(cfqd), cfqq->nr_sectors);
+ cfqg_stats_update_timeslice_used(cfqg, used_sl, unaccounted_sl);
+ cfqg_stats_set_start_empty_time(cfqg);
+}
+
+/**
+ * cfq_init_cfqg_base - initialize base part of a cfq_group
+ * @cfqg: cfq_group to initialize
+ *
+ * Initialize the base part which is used whether %CONFIG_CFQ_GROUP_IOSCHED
+ * is enabled or not.
+ */
+static void cfq_init_cfqg_base(struct cfq_group *cfqg)
+{
+ struct cfq_rb_root *st;
+ int i, j;
+
+ for_each_cfqg_st(cfqg, i, j, st)
+ *st = CFQ_RB_ROOT;
+ RB_CLEAR_NODE(&cfqg->rb_node);
+
+ cfqg->ttime.last_end_request = ktime_get_ns();
+}
+
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val,
+ bool on_dfl, bool reset_dev, bool is_leaf_weight);
+
+static void cfqg_stats_exit(struct cfqg_stats *stats)
+{
+ blkg_rwstat_exit(&stats->merged);
+ blkg_rwstat_exit(&stats->service_time);
+ blkg_rwstat_exit(&stats->wait_time);
+ blkg_rwstat_exit(&stats->queued);
+ blkg_stat_exit(&stats->time);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ blkg_stat_exit(&stats->unaccounted_time);
+ blkg_stat_exit(&stats->avg_queue_size_sum);
+ blkg_stat_exit(&stats->avg_queue_size_samples);
+ blkg_stat_exit(&stats->dequeue);
+ blkg_stat_exit(&stats->group_wait_time);
+ blkg_stat_exit(&stats->idle_time);
+ blkg_stat_exit(&stats->empty_time);
+#endif
+}
+
+static int cfqg_stats_init(struct cfqg_stats *stats, gfp_t gfp)
+{
+ if (blkg_rwstat_init(&stats->merged, gfp) ||
+ blkg_rwstat_init(&stats->service_time, gfp) ||
+ blkg_rwstat_init(&stats->wait_time, gfp) ||
+ blkg_rwstat_init(&stats->queued, gfp) ||
+ blkg_stat_init(&stats->time, gfp))
+ goto err;
+
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ if (blkg_stat_init(&stats->unaccounted_time, gfp) ||
+ blkg_stat_init(&stats->avg_queue_size_sum, gfp) ||
+ blkg_stat_init(&stats->avg_queue_size_samples, gfp) ||
+ blkg_stat_init(&stats->dequeue, gfp) ||
+ blkg_stat_init(&stats->group_wait_time, gfp) ||
+ blkg_stat_init(&stats->idle_time, gfp) ||
+ blkg_stat_init(&stats->empty_time, gfp))
+ goto err;
+#endif
+ return 0;
+err:
+ cfqg_stats_exit(stats);
+ return -ENOMEM;
+}
+
+static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp)
+{
+ struct cfq_group_data *cgd;
+
+ cgd = kzalloc(sizeof(*cgd), gfp);
+ if (!cgd)
+ return NULL;
+ return &cgd->cpd;
+}
+
+static void cfq_cpd_init(struct blkcg_policy_data *cpd)
+{
+ struct cfq_group_data *cgd = cpd_to_cfqgd(cpd);
+ unsigned int weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ?
+ CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL;
+
+ if (cpd_to_blkcg(cpd) == &blkcg_root)
+ weight *= 2;
+
+ cgd->weight = weight;
+ cgd->leaf_weight = weight;
+}
+
+static void cfq_cpd_free(struct blkcg_policy_data *cpd)
+{
+ kfree(cpd_to_cfqgd(cpd));
+}
+
+static void cfq_cpd_bind(struct blkcg_policy_data *cpd)
+{
+ struct blkcg *blkcg = cpd_to_blkcg(cpd);
+ bool on_dfl = cgroup_subsys_on_dfl(io_cgrp_subsys);
+ unsigned int weight = on_dfl ? CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL;
+
+ if (blkcg == &blkcg_root)
+ weight *= 2;
+
+ WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, false));
+ WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, true));
+}
+
+static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
+{
+ struct cfq_group *cfqg;
+
+ cfqg = kzalloc_node(sizeof(*cfqg), gfp, node);
+ if (!cfqg)
+ return NULL;
+
+ cfq_init_cfqg_base(cfqg);
+ if (cfqg_stats_init(&cfqg->stats, gfp)) {
+ kfree(cfqg);
+ return NULL;
+ }
+
+ return &cfqg->pd;
+}
+
+static void cfq_pd_init(struct blkg_policy_data *pd)
+{
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
+ struct cfq_group_data *cgd = blkcg_to_cfqgd(pd->blkg->blkcg);
+
+ cfqg->weight = cgd->weight;
+ cfqg->leaf_weight = cgd->leaf_weight;
+}
+
+static void cfq_pd_offline(struct blkg_policy_data *pd)
+{
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
+ int i;
+
+ for (i = 0; i < IOPRIO_BE_NR; i++) {
+ if (cfqg->async_cfqq[0][i])
+ cfq_put_queue(cfqg->async_cfqq[0][i]);
+ if (cfqg->async_cfqq[1][i])
+ cfq_put_queue(cfqg->async_cfqq[1][i]);
+ }
+
+ if (cfqg->async_idle_cfqq)
+ cfq_put_queue(cfqg->async_idle_cfqq);
+
+ /*
+ * @blkg is going offline and will be ignored by
+ * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so
+ * that they don't get lost. If IOs complete after this point, the
+ * stats for them will be lost. Oh well...
+ */
+ cfqg_stats_xfer_dead(cfqg);
+}
+
+static void cfq_pd_free(struct blkg_policy_data *pd)
+{
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
+
+ cfqg_stats_exit(&cfqg->stats);
+ return kfree(cfqg);
+}
+
+static void cfq_pd_reset_stats(struct blkg_policy_data *pd)
+{
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
+
+ cfqg_stats_reset(&cfqg->stats);
+}
+
+static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd,
+ struct blkcg *blkcg)
+{
+ struct blkcg_gq *blkg;
+
+ blkg = blkg_lookup(blkcg, cfqd->queue);
+ if (likely(blkg))
+ return blkg_to_cfqg(blkg);
+ return NULL;
+}
+
+static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg)
+{
+ cfqq->cfqg = cfqg;
+ /* cfqq reference on cfqg */
+ cfqg_get(cfqg);
+}
+
+static u64 cfqg_prfill_weight_device(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
+
+ if (!cfqg->dev_weight)
+ return 0;
+ return __blkg_prfill_u64(sf, pd, cfqg->dev_weight);
+}
+
+static int cfqg_print_weight_device(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_weight_device, &blkcg_policy_cfq,
+ 0, false);
+ return 0;
+}
+
+static u64 cfqg_prfill_leaf_weight_device(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
+
+ if (!cfqg->dev_leaf_weight)
+ return 0;
+ return __blkg_prfill_u64(sf, pd, cfqg->dev_leaf_weight);
+}
+
+static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_leaf_weight_device, &blkcg_policy_cfq,
+ 0, false);
+ return 0;
+}
+
+static int cfq_print_weight(struct seq_file *sf, void *v)
+{
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
+ unsigned int val = 0;
+
+ if (cgd)
+ val = cgd->weight;
+
+ seq_printf(sf, "%u\n", val);
+ return 0;
+}
+
+static int cfq_print_leaf_weight(struct seq_file *sf, void *v)
+{
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
+ unsigned int val = 0;
+
+ if (cgd)
+ val = cgd->leaf_weight;
+
+ seq_printf(sf, "%u\n", val);
+ return 0;
+}
+
+static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off,
+ bool on_dfl, bool is_leaf_weight)
+{
+ unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN;
+ unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX;
+ struct blkcg *blkcg = css_to_blkcg(of_css(of));
+ struct blkg_conf_ctx ctx;
+ struct cfq_group *cfqg;
+ struct cfq_group_data *cfqgd;
+ int ret;
+ u64 v;
+
+ ret = blkg_conf_prep(blkcg, &blkcg_policy_cfq, buf, &ctx);
+ if (ret)
+ return ret;
+
+ if (sscanf(ctx.body, "%llu", &v) == 1) {
+ /* require "default" on dfl */
+ ret = -ERANGE;
+ if (!v && on_dfl)
+ goto out_finish;
+ } else if (!strcmp(strim(ctx.body), "default")) {
+ v = 0;
+ } else {
+ ret = -EINVAL;
+ goto out_finish;
+ }
+
+ cfqg = blkg_to_cfqg(ctx.blkg);
+ cfqgd = blkcg_to_cfqgd(blkcg);
+
+ ret = -ERANGE;
+ if (!v || (v >= min && v <= max)) {
+ if (!is_leaf_weight) {
+ cfqg->dev_weight = v;
+ cfqg->new_weight = v ?: cfqgd->weight;
+ } else {
+ cfqg->dev_leaf_weight = v;
+ cfqg->new_leaf_weight = v ?: cfqgd->leaf_weight;
+ }
+ ret = 0;
+ }
+out_finish:
+ blkg_conf_finish(&ctx);
+ return ret ?: nbytes;
+}
+
+static ssize_t cfqg_set_weight_device(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ return __cfqg_set_weight_device(of, buf, nbytes, off, false, false);
+}
+
+static ssize_t cfqg_set_leaf_weight_device(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ return __cfqg_set_weight_device(of, buf, nbytes, off, false, true);
+}
+
+static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val,
+ bool on_dfl, bool reset_dev, bool is_leaf_weight)
+{
+ unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN;
+ unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX;
+ struct blkcg *blkcg = css_to_blkcg(css);
+ struct blkcg_gq *blkg;
+ struct cfq_group_data *cfqgd;
+ int ret = 0;
+
+ if (val < min || val > max)
+ return -ERANGE;
+
+ spin_lock_irq(&blkcg->lock);
+ cfqgd = blkcg_to_cfqgd(blkcg);
+ if (!cfqgd) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!is_leaf_weight)
+ cfqgd->weight = val;
+ else
+ cfqgd->leaf_weight = val;
+
+ hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
+ struct cfq_group *cfqg = blkg_to_cfqg(blkg);
+
+ if (!cfqg)
+ continue;
+
+ if (!is_leaf_weight) {
+ if (reset_dev)
+ cfqg->dev_weight = 0;
+ if (!cfqg->dev_weight)
+ cfqg->new_weight = cfqgd->weight;
+ } else {
+ if (reset_dev)
+ cfqg->dev_leaf_weight = 0;
+ if (!cfqg->dev_leaf_weight)
+ cfqg->new_leaf_weight = cfqgd->leaf_weight;
+ }
+ }
+
+out:
+ spin_unlock_irq(&blkcg->lock);
+ return ret;
+}
+
+static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
+ u64 val)
+{
+ return __cfq_set_weight(css, val, false, false, false);
+}
+
+static int cfq_set_leaf_weight(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ return __cfq_set_weight(css, val, false, false, true);
+}
+
+static int cfqg_print_stat(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat,
+ &blkcg_policy_cfq, seq_cft(sf)->private, false);
+ return 0;
+}
+
+static int cfqg_print_rwstat(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat,
+ &blkcg_policy_cfq, seq_cft(sf)->private, true);
+ return 0;
+}
+
+static u64 cfqg_prfill_stat_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ u64 sum = blkg_stat_recursive_sum(pd_to_blkg(pd),
+ &blkcg_policy_cfq, off);
+ return __blkg_prfill_u64(sf, pd, sum);
+}
+
+static u64 cfqg_prfill_rwstat_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct blkg_rwstat sum = blkg_rwstat_recursive_sum(pd_to_blkg(pd),
+ &blkcg_policy_cfq, off);
+ return __blkg_prfill_rwstat(sf, pd, &sum);
+}
+
+static int cfqg_print_stat_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_stat_recursive, &blkcg_policy_cfq,
+ seq_cft(sf)->private, false);
+ return 0;
+}
+
+static int cfqg_print_rwstat_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_rwstat_recursive, &blkcg_policy_cfq,
+ seq_cft(sf)->private, true);
+ return 0;
+}
+
+static u64 cfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off)
+{
+ u64 sum = blkg_rwstat_total(&pd->blkg->stat_bytes);
+
+ return __blkg_prfill_u64(sf, pd, sum >> 9);
+}
+
+static int cfqg_print_stat_sectors(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_sectors, &blkcg_policy_cfq, 0, false);
+ return 0;
+}
+
+static u64 cfqg_prfill_sectors_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct blkg_rwstat tmp = blkg_rwstat_recursive_sum(pd->blkg, NULL,
+ offsetof(struct blkcg_gq, stat_bytes));
+ u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +
+ atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]);
+
+ return __blkg_prfill_u64(sf, pd, sum >> 9);
+}
+
+static int cfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_sectors_recursive, &blkcg_policy_cfq, 0,
+ false);
+ return 0;
+}
+
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
+ u64 samples = blkg_stat_read(&cfqg->stats.avg_queue_size_samples);
+ u64 v = 0;
+
+ if (samples) {
+ v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum);
+ v = div64_u64(v, samples);
+ }
+ __blkg_prfill_u64(sf, pd, v);
+ return 0;
+}
+
+/* print avg_queue_size */
+static int cfqg_print_avg_queue_size(struct seq_file *sf, void *v)
+{
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_avg_queue_size, &blkcg_policy_cfq,
+ 0, false);
+ return 0;
+}
+#endif /* CONFIG_DEBUG_BLK_CGROUP */
+
+static struct cftype cfq_blkcg_legacy_files[] = {
+ /* on root, weight is mapped to leaf_weight */
+ {
+ .name = "weight_device",
+ .flags = CFTYPE_ONLY_ON_ROOT,
+ .seq_show = cfqg_print_leaf_weight_device,
+ .write = cfqg_set_leaf_weight_device,
+ },
+ {
+ .name = "weight",
+ .flags = CFTYPE_ONLY_ON_ROOT,
+ .seq_show = cfq_print_leaf_weight,
+ .write_u64 = cfq_set_leaf_weight,
+ },
+
+ /* no such mapping necessary for !roots */
+ {
+ .name = "weight_device",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cfqg_print_weight_device,
+ .write = cfqg_set_weight_device,
+ },
+ {
+ .name = "weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cfq_print_weight,
+ .write_u64 = cfq_set_weight,
+ },
+
+ {
+ .name = "leaf_weight_device",
+ .seq_show = cfqg_print_leaf_weight_device,
+ .write = cfqg_set_leaf_weight_device,
+ },
+ {
+ .name = "leaf_weight",
+ .seq_show = cfq_print_leaf_weight,
+ .write_u64 = cfq_set_leaf_weight,
+ },
+
+ /* statistics, covers only the tasks in the cfqg */
+ {
+ .name = "time",
+ .private = offsetof(struct cfq_group, stats.time),
+ .seq_show = cfqg_print_stat,
+ },
+ {
+ .name = "sectors",
+ .seq_show = cfqg_print_stat_sectors,
+ },
+ {
+ .name = "io_service_bytes",
+ .private = (unsigned long)&blkcg_policy_cfq,
+ .seq_show = blkg_print_stat_bytes,
+ },
+ {
+ .name = "io_serviced",
+ .private = (unsigned long)&blkcg_policy_cfq,
+ .seq_show = blkg_print_stat_ios,
+ },
+ {
+ .name = "io_service_time",
+ .private = offsetof(struct cfq_group, stats.service_time),
+ .seq_show = cfqg_print_rwstat,
+ },
+ {
+ .name = "io_wait_time",
+ .private = offsetof(struct cfq_group, stats.wait_time),
+ .seq_show = cfqg_print_rwstat,
+ },
+ {
+ .name = "io_merged",
+ .private = offsetof(struct cfq_group, stats.merged),
+ .seq_show = cfqg_print_rwstat,
+ },
+ {
+ .name = "io_queued",
+ .private = offsetof(struct cfq_group, stats.queued),
+ .seq_show = cfqg_print_rwstat,
+ },
+
+ /* the same statictics which cover the cfqg and its descendants */
+ {
+ .name = "time_recursive",
+ .private = offsetof(struct cfq_group, stats.time),
+ .seq_show = cfqg_print_stat_recursive,
+ },
+ {
+ .name = "sectors_recursive",
+ .seq_show = cfqg_print_stat_sectors_recursive,
+ },
+ {
+ .name = "io_service_bytes_recursive",
+ .private = (unsigned long)&blkcg_policy_cfq,
+ .seq_show = blkg_print_stat_bytes_recursive,
+ },
+ {
+ .name = "io_serviced_recursive",
+ .private = (unsigned long)&blkcg_policy_cfq,
+ .seq_show = blkg_print_stat_ios_recursive,
+ },
+ {
+ .name = "io_service_time_recursive",
+ .private = offsetof(struct cfq_group, stats.service_time),
+ .seq_show = cfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "io_wait_time_recursive",
+ .private = offsetof(struct cfq_group, stats.wait_time),
+ .seq_show = cfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "io_merged_recursive",
+ .private = offsetof(struct cfq_group, stats.merged),
+ .seq_show = cfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "io_queued_recursive",
+ .private = offsetof(struct cfq_group, stats.queued),
+ .seq_show = cfqg_print_rwstat_recursive,
+ },
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ {
+ .name = "avg_queue_size",
+ .seq_show = cfqg_print_avg_queue_size,
+ },
+ {
+ .name = "group_wait_time",
+ .private = offsetof(struct cfq_group, stats.group_wait_time),
+ .seq_show = cfqg_print_stat,
+ },
+ {
+ .name = "idle_time",
+ .private = offsetof(struct cfq_group, stats.idle_time),
+ .seq_show = cfqg_print_stat,
+ },
+ {
+ .name = "empty_time",
+ .private = offsetof(struct cfq_group, stats.empty_time),
+ .seq_show = cfqg_print_stat,
+ },
+ {
+ .name = "dequeue",
+ .private = offsetof(struct cfq_group, stats.dequeue),
+ .seq_show = cfqg_print_stat,
+ },
+ {
+ .name = "unaccounted_time",
+ .private = offsetof(struct cfq_group, stats.unaccounted_time),
+ .seq_show = cfqg_print_stat,
+ },
+#endif /* CONFIG_DEBUG_BLK_CGROUP */
+ { } /* terminate */
+};
+
+static int cfq_print_weight_on_dfl(struct seq_file *sf, void *v)
+{
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
+
+ seq_printf(sf, "default %u\n", cgd->weight);
+ blkcg_print_blkgs(sf, blkcg, cfqg_prfill_weight_device,
+ &blkcg_policy_cfq, 0, false);
+ return 0;
+}
+
+static ssize_t cfq_set_weight_on_dfl(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ char *endp;
+ int ret;
+ u64 v;
+
+ buf = strim(buf);
+
+ /* "WEIGHT" or "default WEIGHT" sets the default weight */
+ v = simple_strtoull(buf, &endp, 0);
+ if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) {
+ ret = __cfq_set_weight(of_css(of), v, true, false, false);
+ return ret ?: nbytes;
+ }
+
+ /* "MAJ:MIN WEIGHT" */
+ return __cfqg_set_weight_device(of, buf, nbytes, off, true, false);
+}
+
+static struct cftype cfq_blkcg_files[] = {
+ {
+ .name = "weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cfq_print_weight_on_dfl,
+ .write = cfq_set_weight_on_dfl,
+ },
+ { } /* terminate */
+};
+
+#else /* GROUP_IOSCHED */
+static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd,
+ struct blkcg *blkcg)
+{
+ return cfqd->root_group;
+}
+
+static inline void
+cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) {
+ cfqq->cfqg = cfqg;
+}
+
+#endif /* GROUP_IOSCHED */
+
+/*
+ * The cfqd->service_trees holds all pending cfq_queue's that have
+ * requests waiting to be processed. It is sorted in the order that
+ * we will service the queues.
+ */
+static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ bool add_front)
+{
+ struct rb_node **p, *parent;
+ struct cfq_queue *__cfqq;
+ u64 rb_key;
+ struct cfq_rb_root *st;
+ bool leftmost = true;
+ int new_cfqq = 1;
+ u64 now = ktime_get_ns();
+
+ st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq));
+ if (cfq_class_idle(cfqq)) {
+ rb_key = CFQ_IDLE_DELAY;
+ parent = st->rb_rightmost;
+ if (parent && parent != &cfqq->rb_node) {
+ __cfqq = rb_entry(parent, struct cfq_queue, rb_node);
+ rb_key += __cfqq->rb_key;
+ } else
+ rb_key += now;
+ } else if (!add_front) {
+ /*
+ * Get our rb key offset. Subtract any residual slice
+ * value carried from last service. A negative resid
+ * count indicates slice overrun, and this should position
+ * the next service time further away in the tree.
+ */
+ rb_key = cfq_slice_offset(cfqd, cfqq) + now;
+ rb_key -= cfqq->slice_resid;
+ cfqq->slice_resid = 0;
+ } else {
+ rb_key = -NSEC_PER_SEC;
+ __cfqq = cfq_rb_first(st);
+ rb_key += __cfqq ? __cfqq->rb_key : now;
+ }
+
+ if (!RB_EMPTY_NODE(&cfqq->rb_node)) {
+ new_cfqq = 0;
+ /*
+ * same position, nothing more to do
+ */
+ if (rb_key == cfqq->rb_key && cfqq->service_tree == st)
+ return;
+
+ cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree);
+ cfqq->service_tree = NULL;
+ }
+
+ parent = NULL;
+ cfqq->service_tree = st;
+ p = &st->rb.rb_root.rb_node;
+ while (*p) {
+ parent = *p;
+ __cfqq = rb_entry(parent, struct cfq_queue, rb_node);
+
+ /*
+ * sort by key, that represents service time.
+ */
+ if (rb_key < __cfqq->rb_key)
+ p = &parent->rb_left;
+ else {
+ p = &parent->rb_right;
+ leftmost = false;
+ }
+ }
+
+ cfqq->rb_key = rb_key;
+ rb_link_node(&cfqq->rb_node, parent, p);
+ rb_insert_color_cached(&cfqq->rb_node, &st->rb, leftmost);
+ st->count++;
+ if (add_front || !new_cfqq)
+ return;
+ cfq_group_notify_queue_add(cfqd, cfqq->cfqg);
+}
+
+static struct cfq_queue *
+cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root,
+ sector_t sector, struct rb_node **ret_parent,
+ struct rb_node ***rb_link)
+{
+ struct rb_node **p, *parent;
+ struct cfq_queue *cfqq = NULL;
+
+ parent = NULL;
+ p = &root->rb_node;
+ while (*p) {
+ struct rb_node **n;
+
+ parent = *p;
+ cfqq = rb_entry(parent, struct cfq_queue, p_node);
+
+ /*
+ * Sort strictly based on sector. Smallest to the left,
+ * largest to the right.
+ */
+ if (sector > blk_rq_pos(cfqq->next_rq))
+ n = &(*p)->rb_right;
+ else if (sector < blk_rq_pos(cfqq->next_rq))
+ n = &(*p)->rb_left;
+ else
+ break;
+ p = n;
+ cfqq = NULL;
+ }
+
+ *ret_parent = parent;
+ if (rb_link)
+ *rb_link = p;
+ return cfqq;
+}
+
+static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ struct rb_node **p, *parent;
+ struct cfq_queue *__cfqq;
+
+ if (cfqq->p_root) {
+ rb_erase(&cfqq->p_node, cfqq->p_root);
+ cfqq->p_root = NULL;
+ }
+
+ if (cfq_class_idle(cfqq))
+ return;
+ if (!cfqq->next_rq)
+ return;
+
+ cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio];
+ __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root,
+ blk_rq_pos(cfqq->next_rq), &parent, &p);
+ if (!__cfqq) {
+ rb_link_node(&cfqq->p_node, parent, p);
+ rb_insert_color(&cfqq->p_node, cfqq->p_root);
+ } else
+ cfqq->p_root = NULL;
+}
+
+/*
+ * Update cfqq's position in the service tree.
+ */
+static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ /*
+ * Resorting requires the cfqq to be on the RR list already.
+ */
+ if (cfq_cfqq_on_rr(cfqq)) {
+ cfq_service_tree_add(cfqd, cfqq, 0);
+ cfq_prio_tree_add(cfqd, cfqq);
+ }
+}
+
+/*
+ * add to busy list of queues for service, trying to be fair in ordering
+ * the pending list according to last request service
+ */
+static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ cfq_log_cfqq(cfqd, cfqq, "add_to_rr");
+ BUG_ON(cfq_cfqq_on_rr(cfqq));
+ cfq_mark_cfqq_on_rr(cfqq);
+ cfqd->busy_queues++;
+ if (cfq_cfqq_sync(cfqq))
+ cfqd->busy_sync_queues++;
+
+ cfq_resort_rr_list(cfqd, cfqq);
+}
+
+/*
+ * Called when the cfqq no longer has requests pending, remove it from
+ * the service tree.
+ */
+static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ cfq_log_cfqq(cfqd, cfqq, "del_from_rr");
+ BUG_ON(!cfq_cfqq_on_rr(cfqq));
+ cfq_clear_cfqq_on_rr(cfqq);
+
+ if (!RB_EMPTY_NODE(&cfqq->rb_node)) {
+ cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree);
+ cfqq->service_tree = NULL;
+ }
+ if (cfqq->p_root) {
+ rb_erase(&cfqq->p_node, cfqq->p_root);
+ cfqq->p_root = NULL;
+ }
+
+ cfq_group_notify_queue_del(cfqd, cfqq->cfqg);
+ BUG_ON(!cfqd->busy_queues);
+ cfqd->busy_queues--;
+ if (cfq_cfqq_sync(cfqq))
+ cfqd->busy_sync_queues--;
+}
+
+/*
+ * rb tree support functions
+ */
+static void cfq_del_rq_rb(struct request *rq)
+{
+ struct cfq_queue *cfqq = RQ_CFQQ(rq);
+ const int sync = rq_is_sync(rq);
+
+ BUG_ON(!cfqq->queued[sync]);
+ cfqq->queued[sync]--;
+
+ elv_rb_del(&cfqq->sort_list, rq);
+
+ if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) {
+ /*
+ * Queue will be deleted from service tree when we actually
+ * expire it later. Right now just remove it from prio tree
+ * as it is empty.
+ */
+ if (cfqq->p_root) {
+ rb_erase(&cfqq->p_node, cfqq->p_root);
+ cfqq->p_root = NULL;
+ }
+ }
+}
+
+static void cfq_add_rq_rb(struct request *rq)
+{
+ struct cfq_queue *cfqq = RQ_CFQQ(rq);
+ struct cfq_data *cfqd = cfqq->cfqd;
+ struct request *prev;
+
+ cfqq->queued[rq_is_sync(rq)]++;
+
+ elv_rb_add(&cfqq->sort_list, rq);
+
+ if (!cfq_cfqq_on_rr(cfqq))
+ cfq_add_cfqq_rr(cfqd, cfqq);
+
+ /*
+ * check if this request is a better next-serve candidate
+ */
+ prev = cfqq->next_rq;
+ cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position);
+
+ /*
+ * adjust priority tree position, if ->next_rq changes
+ */
+ if (prev != cfqq->next_rq)
+ cfq_prio_tree_add(cfqd, cfqq);
+
+ BUG_ON(!cfqq->next_rq);
+}
+
+static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
+{
+ elv_rb_del(&cfqq->sort_list, rq);
+ cfqq->queued[rq_is_sync(rq)]--;
+ cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags);
+ cfq_add_rq_rb(rq);
+ cfqg_stats_update_io_add(RQ_CFQG(rq), cfqq->cfqd->serving_group,
+ rq->cmd_flags);
+}
+
+static struct request *
+cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
+{
+ struct task_struct *tsk = current;
+ struct cfq_io_cq *cic;
+ struct cfq_queue *cfqq;
+
+ cic = cfq_cic_lookup(cfqd, tsk->io_context);
+ if (!cic)
+ return NULL;
+
+ cfqq = cic_to_cfqq(cic, op_is_sync(bio->bi_opf));
+ if (cfqq)
+ return elv_rb_find(&cfqq->sort_list, bio_end_sector(bio));
+
+ return NULL;
+}
+
+static void cfq_activate_request(struct request_queue *q, struct request *rq)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+
+ cfqd->rq_in_driver++;
+ cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d",
+ cfqd->rq_in_driver);
+
+ cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq);
+}
+
+static void cfq_deactivate_request(struct request_queue *q, struct request *rq)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+
+ WARN_ON(!cfqd->rq_in_driver);
+ cfqd->rq_in_driver--;
+ cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d",
+ cfqd->rq_in_driver);
+}
+
+static void cfq_remove_request(struct request *rq)
+{
+ struct cfq_queue *cfqq = RQ_CFQQ(rq);
+
+ if (cfqq->next_rq == rq)
+ cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq);
+
+ list_del_init(&rq->queuelist);
+ cfq_del_rq_rb(rq);
+
+ cfqq->cfqd->rq_queued--;
+ cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags);
+ if (rq->cmd_flags & REQ_PRIO) {
+ WARN_ON(!cfqq->prio_pending);
+ cfqq->prio_pending--;
+ }
+}
+
+static enum elv_merge cfq_merge(struct request_queue *q, struct request **req,
+ struct bio *bio)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+ struct request *__rq;
+
+ __rq = cfq_find_rq_fmerge(cfqd, bio);
+ if (__rq && elv_bio_merge_ok(__rq, bio)) {
+ *req = __rq;
+ return ELEVATOR_FRONT_MERGE;
+ }
+
+ return ELEVATOR_NO_MERGE;
+}
+
+static void cfq_merged_request(struct request_queue *q, struct request *req,
+ enum elv_merge type)
+{
+ if (type == ELEVATOR_FRONT_MERGE) {
+ struct cfq_queue *cfqq = RQ_CFQQ(req);
+
+ cfq_reposition_rq_rb(cfqq, req);
+ }
+}
+
+static void cfq_bio_merged(struct request_queue *q, struct request *req,
+ struct bio *bio)
+{
+ cfqg_stats_update_io_merged(RQ_CFQG(req), bio->bi_opf);
+}
+
+static void
+cfq_merged_requests(struct request_queue *q, struct request *rq,
+ struct request *next)
+{
+ struct cfq_queue *cfqq = RQ_CFQQ(rq);
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+
+ /*
+ * reposition in fifo if next is older than rq
+ */
+ if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) &&
+ next->fifo_time < rq->fifo_time &&
+ cfqq == RQ_CFQQ(next)) {
+ list_move(&rq->queuelist, &next->queuelist);
+ rq->fifo_time = next->fifo_time;
+ }
+
+ if (cfqq->next_rq == next)
+ cfqq->next_rq = rq;
+ cfq_remove_request(next);
+ cfqg_stats_update_io_merged(RQ_CFQG(rq), next->cmd_flags);
+
+ cfqq = RQ_CFQQ(next);
+ /*
+ * all requests of this queue are merged to other queues, delete it
+ * from the service tree. If it's the active_queue,
+ * cfq_dispatch_requests() will choose to expire it or do idle
+ */
+ if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list) &&
+ cfqq != cfqd->active_queue)
+ cfq_del_cfqq_rr(cfqd, cfqq);
+}
+
+static int cfq_allow_bio_merge(struct request_queue *q, struct request *rq,
+ struct bio *bio)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+ bool is_sync = op_is_sync(bio->bi_opf);
+ struct cfq_io_cq *cic;
+ struct cfq_queue *cfqq;
+
+ /*
+ * Disallow merge of a sync bio into an async request.
+ */
+ if (is_sync && !rq_is_sync(rq))
+ return false;
+
+ /*
+ * Lookup the cfqq that this bio will be queued with and allow
+ * merge only if rq is queued there.
+ */
+ cic = cfq_cic_lookup(cfqd, current->io_context);
+ if (!cic)
+ return false;
+
+ cfqq = cic_to_cfqq(cic, is_sync);
+ return cfqq == RQ_CFQQ(rq);
+}
+
+static int cfq_allow_rq_merge(struct request_queue *q, struct request *rq,
+ struct request *next)
+{
+ return RQ_CFQQ(rq) == RQ_CFQQ(next);
+}
+
+static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ hrtimer_try_to_cancel(&cfqd->idle_slice_timer);
+ cfqg_stats_update_idle_time(cfqq->cfqg);
+}
+
+static void __cfq_set_active_queue(struct cfq_data *cfqd,
+ struct cfq_queue *cfqq)
+{
+ if (cfqq) {
+ cfq_log_cfqq(cfqd, cfqq, "set_active wl_class:%d wl_type:%d",
+ cfqd->serving_wl_class, cfqd->serving_wl_type);
+ cfqg_stats_update_avg_queue_size(cfqq->cfqg);
+ cfqq->slice_start = 0;
+ cfqq->dispatch_start = ktime_get_ns();
+ cfqq->allocated_slice = 0;
+ cfqq->slice_end = 0;
+ cfqq->slice_dispatch = 0;
+ cfqq->nr_sectors = 0;
+
+ cfq_clear_cfqq_wait_request(cfqq);
+ cfq_clear_cfqq_must_dispatch(cfqq);
+ cfq_clear_cfqq_must_alloc_slice(cfqq);
+ cfq_clear_cfqq_fifo_expire(cfqq);
+ cfq_mark_cfqq_slice_new(cfqq);
+
+ cfq_del_timer(cfqd, cfqq);
+ }
+
+ cfqd->active_queue = cfqq;
+}
+
+/*
+ * current cfqq expired its slice (or was too idle), select new one
+ */
+static void
+__cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ bool timed_out)
+{
+ cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out);
+
+ if (cfq_cfqq_wait_request(cfqq))
+ cfq_del_timer(cfqd, cfqq);
+
+ cfq_clear_cfqq_wait_request(cfqq);
+ cfq_clear_cfqq_wait_busy(cfqq);
+
+ /*
+ * If this cfqq is shared between multiple processes, check to
+ * make sure that those processes are still issuing I/Os within
+ * the mean seek distance. If not, it may be time to break the
+ * queues apart again.
+ */
+ if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq))
+ cfq_mark_cfqq_split_coop(cfqq);
+
+ /*
+ * store what was left of this slice, if the queue idled/timed out
+ */
+ if (timed_out) {
+ if (cfq_cfqq_slice_new(cfqq))
+ cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq);
+ else
+ cfqq->slice_resid = cfqq->slice_end - ktime_get_ns();
+ cfq_log_cfqq(cfqd, cfqq, "resid=%lld", cfqq->slice_resid);
+ }
+
+ cfq_group_served(cfqd, cfqq->cfqg, cfqq);
+
+ if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
+ cfq_del_cfqq_rr(cfqd, cfqq);
+
+ cfq_resort_rr_list(cfqd, cfqq);
+
+ if (cfqq == cfqd->active_queue)
+ cfqd->active_queue = NULL;
+
+ if (cfqd->active_cic) {
+ put_io_context(cfqd->active_cic->icq.ioc);
+ cfqd->active_cic = NULL;
+ }
+}
+
+static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out)
+{
+ struct cfq_queue *cfqq = cfqd->active_queue;
+
+ if (cfqq)
+ __cfq_slice_expired(cfqd, cfqq, timed_out);
+}
+
+/*
+ * Get next queue for service. Unless we have a queue preemption,
+ * we'll simply select the first cfqq in the service tree.
+ */
+static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
+{
+ struct cfq_rb_root *st = st_for(cfqd->serving_group,
+ cfqd->serving_wl_class, cfqd->serving_wl_type);
+
+ if (!cfqd->rq_queued)
+ return NULL;
+
+ /* There is nothing to dispatch */
+ if (!st)
+ return NULL;
+ if (RB_EMPTY_ROOT(&st->rb.rb_root))
+ return NULL;
+ return cfq_rb_first(st);
+}
+
+static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
+{
+ struct cfq_group *cfqg;
+ struct cfq_queue *cfqq;
+ int i, j;
+ struct cfq_rb_root *st;
+
+ if (!cfqd->rq_queued)
+ return NULL;
+
+ cfqg = cfq_get_next_cfqg(cfqd);
+ if (!cfqg)
+ return NULL;
+
+ for_each_cfqg_st(cfqg, i, j, st) {
+ cfqq = cfq_rb_first(st);
+ if (cfqq)
+ return cfqq;
+ }
+ return NULL;
+}
+
+/*
+ * Get and set a new active queue for service.
+ */
+static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd,
+ struct cfq_queue *cfqq)
+{
+ if (!cfqq)
+ cfqq = cfq_get_next_queue(cfqd);
+
+ __cfq_set_active_queue(cfqd, cfqq);
+ return cfqq;
+}
+
+static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd,
+ struct request *rq)
+{
+ if (blk_rq_pos(rq) >= cfqd->last_position)
+ return blk_rq_pos(rq) - cfqd->last_position;
+ else
+ return cfqd->last_position - blk_rq_pos(rq);
+}
+
+static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ struct request *rq)
+{
+ return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR;
+}
+
+static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
+ struct cfq_queue *cur_cfqq)
+{
+ struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio];
+ struct rb_node *parent, *node;
+ struct cfq_queue *__cfqq;
+ sector_t sector = cfqd->last_position;
+
+ if (RB_EMPTY_ROOT(root))
+ return NULL;
+
+ /*
+ * First, if we find a request starting at the end of the last
+ * request, choose it.
+ */
+ __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL);
+ if (__cfqq)
+ return __cfqq;
+
+ /*
+ * If the exact sector wasn't found, the parent of the NULL leaf
+ * will contain the closest sector.
+ */
+ __cfqq = rb_entry(parent, struct cfq_queue, p_node);
+ if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
+ return __cfqq;
+
+ if (blk_rq_pos(__cfqq->next_rq) < sector)
+ node = rb_next(&__cfqq->p_node);
+ else
+ node = rb_prev(&__cfqq->p_node);
+ if (!node)
+ return NULL;
+
+ __cfqq = rb_entry(node, struct cfq_queue, p_node);
+ if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
+ return __cfqq;
+
+ return NULL;
+}
+
+/*
+ * cfqd - obvious
+ * cur_cfqq - passed in so that we don't decide that the current queue is
+ * closely cooperating with itself.
+ *
+ * So, basically we're assuming that that cur_cfqq has dispatched at least
+ * one request, and that cfqd->last_position reflects a position on the disk
+ * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid
+ * assumption.
+ */
+static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd,
+ struct cfq_queue *cur_cfqq)
+{
+ struct cfq_queue *cfqq;
+
+ if (cfq_class_idle(cur_cfqq))
+ return NULL;
+ if (!cfq_cfqq_sync(cur_cfqq))
+ return NULL;
+ if (CFQQ_SEEKY(cur_cfqq))
+ return NULL;
+
+ /*
+ * Don't search priority tree if it's the only queue in the group.
+ */
+ if (cur_cfqq->cfqg->nr_cfqq == 1)
+ return NULL;
+
+ /*
+ * We should notice if some of the queues are cooperating, eg
+ * working closely on the same area of the disk. In that case,
+ * we can group them together and don't waste time idling.
+ */
+ cfqq = cfqq_close(cfqd, cur_cfqq);
+ if (!cfqq)
+ return NULL;
+
+ /* If new queue belongs to different cfq_group, don't choose it */
+ if (cur_cfqq->cfqg != cfqq->cfqg)
+ return NULL;
+
+ /*
+ * It only makes sense to merge sync queues.
+ */
+ if (!cfq_cfqq_sync(cfqq))
+ return NULL;
+ if (CFQQ_SEEKY(cfqq))
+ return NULL;
+
+ /*
+ * Do not merge queues of different priority classes
+ */
+ if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq))
+ return NULL;
+
+ return cfqq;
+}
+
+/*
+ * Determine whether we should enforce idle window for this queue.
+ */
+
+static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ enum wl_class_t wl_class = cfqq_class(cfqq);
+ struct cfq_rb_root *st = cfqq->service_tree;
+
+ BUG_ON(!st);
+ BUG_ON(!st->count);
+
+ if (!cfqd->cfq_slice_idle)
+ return false;
+
+ /* We never do for idle class queues. */
+ if (wl_class == IDLE_WORKLOAD)
+ return false;
+
+ /* We do for queues that were marked with idle window flag. */
+ if (cfq_cfqq_idle_window(cfqq) &&
+ !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag))
+ return true;
+
+ /*
+ * Otherwise, we do only if they are the last ones
+ * in their service tree.
+ */
+ if (st->count == 1 && cfq_cfqq_sync(cfqq) &&
+ !cfq_io_thinktime_big(cfqd, &st->ttime, false))
+ return true;
+ cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", st->count);
+ return false;
+}
+
+static void cfq_arm_slice_timer(struct cfq_data *cfqd)
+{
+ struct cfq_queue *cfqq = cfqd->active_queue;
+ struct cfq_rb_root *st = cfqq->service_tree;
+ struct cfq_io_cq *cic;
+ u64 sl, group_idle = 0;
+ u64 now = ktime_get_ns();
+
+ /*
+ * SSD device without seek penalty, disable idling. But only do so
+ * for devices that support queuing, otherwise we still have a problem
+ * with sync vs async workloads.
+ */
+ if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag &&
+ !cfqd->cfq_group_idle)
+ return;
+
+ WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list));
+ WARN_ON(cfq_cfqq_slice_new(cfqq));
+
+ /*
+ * idle is disabled, either manually or by past process history
+ */
+ if (!cfq_should_idle(cfqd, cfqq)) {
+ /* no queue idling. Check for group idling */
+ if (cfqd->cfq_group_idle)
+ group_idle = cfqd->cfq_group_idle;
+ else
+ return;
+ }
+
+ /*
+ * still active requests from this queue, don't idle
+ */
+ if (cfqq->dispatched)
+ return;
+
+ /*
+ * task has exited, don't wait
+ */
+ cic = cfqd->active_cic;
+ if (!cic || !atomic_read(&cic->icq.ioc->active_ref))
+ return;
+
+ /*
+ * If our average think time is larger than the remaining time
+ * slice, then don't idle. This avoids overrunning the allotted
+ * time slice.
+ */
+ if (sample_valid(cic->ttime.ttime_samples) &&
+ (cfqq->slice_end - now < cic->ttime.ttime_mean)) {
+ cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%llu",
+ cic->ttime.ttime_mean);
+ return;
+ }
+
+ /*
+ * There are other queues in the group or this is the only group and
+ * it has too big thinktime, don't do group idle.
+ */
+ if (group_idle &&
+ (cfqq->cfqg->nr_cfqq > 1 ||
+ cfq_io_thinktime_big(cfqd, &st->ttime, true)))
+ return;
+
+ cfq_mark_cfqq_wait_request(cfqq);
+
+ if (group_idle)
+ sl = cfqd->cfq_group_idle;
+ else
+ sl = cfqd->cfq_slice_idle;
+
+ hrtimer_start(&cfqd->idle_slice_timer, ns_to_ktime(sl),
+ HRTIMER_MODE_REL);
+ cfqg_stats_set_start_idle_time(cfqq->cfqg);
+ cfq_log_cfqq(cfqd, cfqq, "arm_idle: %llu group_idle: %d", sl,
+ group_idle ? 1 : 0);
+}
+
+/*
+ * Move request from internal lists to the request queue dispatch list.
+ */
+static void cfq_dispatch_insert(struct request_queue *q, struct request *rq)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+ struct cfq_queue *cfqq = RQ_CFQQ(rq);
+
+ cfq_log_cfqq(cfqd, cfqq, "dispatch_insert");
+
+ cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq);
+ cfq_remove_request(rq);
+ cfqq->dispatched++;
+ (RQ_CFQG(rq))->dispatched++;
+ elv_dispatch_sort(q, rq);
+
+ cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;
+ cfqq->nr_sectors += blk_rq_sectors(rq);
+}
+
+/*
+ * return expired entry, or NULL to just start from scratch in rbtree
+ */
+static struct request *cfq_check_fifo(struct cfq_queue *cfqq)
+{
+ struct request *rq = NULL;
+
+ if (cfq_cfqq_fifo_expire(cfqq))
+ return NULL;
+
+ cfq_mark_cfqq_fifo_expire(cfqq);
+
+ if (list_empty(&cfqq->fifo))
+ return NULL;
+
+ rq = rq_entry_fifo(cfqq->fifo.next);
+ if (ktime_get_ns() < rq->fifo_time)
+ rq = NULL;
+
+ return rq;
+}
+
+static inline int
+cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ const int base_rq = cfqd->cfq_slice_async_rq;
+
+ WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR);
+
+ return 2 * base_rq * (IOPRIO_BE_NR - cfqq->ioprio);
+}
+
+/*
+ * Must be called with the queue_lock held.
+ */
+static int cfqq_process_refs(struct cfq_queue *cfqq)
+{
+ int process_refs, io_refs;
+
+ io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE];
+ process_refs = cfqq->ref - io_refs;
+ BUG_ON(process_refs < 0);
+ return process_refs;
+}
+
+static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq)
+{
+ int process_refs, new_process_refs;
+ struct cfq_queue *__cfqq;
+
+ /*
+ * If there are no process references on the new_cfqq, then it is
+ * unsafe to follow the ->new_cfqq chain as other cfqq's in the
+ * chain may have dropped their last reference (not just their
+ * last process reference).
+ */
+ if (!cfqq_process_refs(new_cfqq))
+ return;
+
+ /* Avoid a circular list and skip interim queue merges */
+ while ((__cfqq = new_cfqq->new_cfqq)) {
+ if (__cfqq == cfqq)
+ return;
+ new_cfqq = __cfqq;
+ }
+
+ process_refs = cfqq_process_refs(cfqq);
+ new_process_refs = cfqq_process_refs(new_cfqq);
+ /*
+ * If the process for the cfqq has gone away, there is no
+ * sense in merging the queues.
+ */
+ if (process_refs == 0 || new_process_refs == 0)
+ return;
+
+ /*
+ * Merge in the direction of the lesser amount of work.
+ */
+ if (new_process_refs >= process_refs) {
+ cfqq->new_cfqq = new_cfqq;
+ new_cfqq->ref += process_refs;
+ } else {
+ new_cfqq->new_cfqq = cfqq;
+ cfqq->ref += new_process_refs;
+ }
+}
+
+static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd,
+ struct cfq_group *cfqg, enum wl_class_t wl_class)
+{
+ struct cfq_queue *queue;
+ int i;
+ bool key_valid = false;
+ u64 lowest_key = 0;
+ enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD;
+
+ for (i = 0; i <= SYNC_WORKLOAD; ++i) {
+ /* select the one with lowest rb_key */
+ queue = cfq_rb_first(st_for(cfqg, wl_class, i));
+ if (queue &&
+ (!key_valid || queue->rb_key < lowest_key)) {
+ lowest_key = queue->rb_key;
+ cur_best = i;
+ key_valid = true;
+ }
+ }
+
+ return cur_best;
+}
+
+static void
+choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg)
+{
+ u64 slice;
+ unsigned count;
+ struct cfq_rb_root *st;
+ u64 group_slice;
+ enum wl_class_t original_class = cfqd->serving_wl_class;
+ u64 now = ktime_get_ns();
+
+ /* Choose next priority. RT > BE > IDLE */
+ if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg))
+ cfqd->serving_wl_class = RT_WORKLOAD;
+ else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg))
+ cfqd->serving_wl_class = BE_WORKLOAD;
+ else {
+ cfqd->serving_wl_class = IDLE_WORKLOAD;
+ cfqd->workload_expires = now + jiffies_to_nsecs(1);
+ return;
+ }
+
+ if (original_class != cfqd->serving_wl_class)
+ goto new_workload;
+
+ /*
+ * For RT and BE, we have to choose also the type
+ * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload
+ * expiration time
+ */
+ st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type);
+ count = st->count;
+
+ /*
+ * check workload expiration, and that we still have other queues ready
+ */
+ if (count && !(now > cfqd->workload_expires))
+ return;
+
+new_workload:
+ /* otherwise select new workload type */
+ cfqd->serving_wl_type = cfq_choose_wl_type(cfqd, cfqg,
+ cfqd->serving_wl_class);
+ st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type);
+ count = st->count;
+
+ /*
+ * the workload slice is computed as a fraction of target latency
+ * proportional to the number of queues in that workload, over
+ * all the queues in the same priority class
+ */
+ group_slice = cfq_group_slice(cfqd, cfqg);
+
+ slice = div_u64(group_slice * count,
+ max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class],
+ cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd,
+ cfqg)));
+
+ if (cfqd->serving_wl_type == ASYNC_WORKLOAD) {
+ u64 tmp;
+
+ /*
+ * Async queues are currently system wide. Just taking
+ * proportion of queues with-in same group will lead to higher
+ * async ratio system wide as generally root group is going
+ * to have higher weight. A more accurate thing would be to
+ * calculate system wide asnc/sync ratio.
+ */
+ tmp = cfqd->cfq_target_latency *
+ cfqg_busy_async_queues(cfqd, cfqg);
+ tmp = div_u64(tmp, cfqd->busy_queues);
+ slice = min_t(u64, slice, tmp);
+
+ /* async workload slice is scaled down according to
+ * the sync/async slice ratio. */
+ slice = div64_u64(slice*cfqd->cfq_slice[0], cfqd->cfq_slice[1]);
+ } else
+ /* sync workload slice is at least 2 * cfq_slice_idle */
+ slice = max(slice, 2 * cfqd->cfq_slice_idle);
+
+ slice = max_t(u64, slice, CFQ_MIN_TT);
+ cfq_log(cfqd, "workload slice:%llu", slice);
+ cfqd->workload_expires = now + slice;
+}
+
+static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd)
+{
+ struct cfq_rb_root *st = &cfqd->grp_service_tree;
+ struct cfq_group *cfqg;
+
+ if (RB_EMPTY_ROOT(&st->rb.rb_root))
+ return NULL;
+ cfqg = cfq_rb_first_group(st);
+ update_min_vdisktime(st);
+ return cfqg;
+}
+
+static void cfq_choose_cfqg(struct cfq_data *cfqd)
+{
+ struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd);
+ u64 now = ktime_get_ns();
+
+ cfqd->serving_group = cfqg;
+
+ /* Restore the workload type data */
+ if (cfqg->saved_wl_slice) {
+ cfqd->workload_expires = now + cfqg->saved_wl_slice;
+ cfqd->serving_wl_type = cfqg->saved_wl_type;
+ cfqd->serving_wl_class = cfqg->saved_wl_class;
+ } else
+ cfqd->workload_expires = now - 1;
+
+ choose_wl_class_and_type(cfqd, cfqg);
+}
+
+/*
+ * Select a queue for service. If we have a current active queue,
+ * check whether to continue servicing it, or retrieve and set a new one.
+ */
+static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
+{
+ struct cfq_queue *cfqq, *new_cfqq = NULL;
+ u64 now = ktime_get_ns();
+
+ cfqq = cfqd->active_queue;
+ if (!cfqq)
+ goto new_queue;
+
+ if (!cfqd->rq_queued)
+ return NULL;
+
+ /*
+ * We were waiting for group to get backlogged. Expire the queue
+ */
+ if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list))
+ goto expire;
+
+ /*
+ * The active queue has run out of time, expire it and select new.
+ */
+ if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) {
+ /*
+ * If slice had not expired at the completion of last request
+ * we might not have turned on wait_busy flag. Don't expire
+ * the queue yet. Allow the group to get backlogged.
+ *
+ * The very fact that we have used the slice, that means we
+ * have been idling all along on this queue and it should be
+ * ok to wait for this request to complete.
+ */
+ if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list)
+ && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) {
+ cfqq = NULL;
+ goto keep_queue;
+ } else
+ goto check_group_idle;
+ }
+
+ /*
+ * The active queue has requests and isn't expired, allow it to
+ * dispatch.
+ */
+ if (!RB_EMPTY_ROOT(&cfqq->sort_list))
+ goto keep_queue;
+
+ /*
+ * If another queue has a request waiting within our mean seek
+ * distance, let it run. The expire code will check for close
+ * cooperators and put the close queue at the front of the service
+ * tree. If possible, merge the expiring queue with the new cfqq.
+ */
+ new_cfqq = cfq_close_cooperator(cfqd, cfqq);
+ if (new_cfqq) {
+ if (!cfqq->new_cfqq)
+ cfq_setup_merge(cfqq, new_cfqq);
+ goto expire;
+ }
+
+ /*
+ * No requests pending. If the active queue still has requests in
+ * flight or is idling for a new request, allow either of these
+ * conditions to happen (or time out) before selecting a new queue.
+ */
+ if (hrtimer_active(&cfqd->idle_slice_timer)) {
+ cfqq = NULL;
+ goto keep_queue;
+ }
+
+ /*
+ * This is a deep seek queue, but the device is much faster than
+ * the queue can deliver, don't idle
+ **/
+ if (CFQQ_SEEKY(cfqq) && cfq_cfqq_idle_window(cfqq) &&
+ (cfq_cfqq_slice_new(cfqq) ||
+ (cfqq->slice_end - now > now - cfqq->slice_start))) {
+ cfq_clear_cfqq_deep(cfqq);
+ cfq_clear_cfqq_idle_window(cfqq);
+ }
+
+ if (cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) {
+ cfqq = NULL;
+ goto keep_queue;
+ }
+
+ /*
+ * If group idle is enabled and there are requests dispatched from
+ * this group, wait for requests to complete.
+ */
+check_group_idle:
+ if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 &&
+ cfqq->cfqg->dispatched &&
+ !cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) {
+ cfqq = NULL;
+ goto keep_queue;
+ }
+
+expire:
+ cfq_slice_expired(cfqd, 0);
+new_queue:
+ /*
+ * Current queue expired. Check if we have to switch to a new
+ * service tree
+ */
+ if (!new_cfqq)
+ cfq_choose_cfqg(cfqd);
+
+ cfqq = cfq_set_active_queue(cfqd, new_cfqq);
+keep_queue:
+ return cfqq;
+}
+
+static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
+{
+ int dispatched = 0;
+
+ while (cfqq->next_rq) {
+ cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq);
+ dispatched++;
+ }
+
+ BUG_ON(!list_empty(&cfqq->fifo));
+
+ /* By default cfqq is not expired if it is empty. Do it explicitly */
+ __cfq_slice_expired(cfqq->cfqd, cfqq, 0);
+ return dispatched;
+}
+
+/*
+ * Drain our current requests. Used for barriers and when switching
+ * io schedulers on-the-fly.
+ */
+static int cfq_forced_dispatch(struct cfq_data *cfqd)
+{
+ struct cfq_queue *cfqq;
+ int dispatched = 0;
+
+ /* Expire the timeslice of the current active queue first */
+ cfq_slice_expired(cfqd, 0);
+ while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) {
+ __cfq_set_active_queue(cfqd, cfqq);
+ dispatched += __cfq_forced_dispatch_cfqq(cfqq);
+ }
+
+ BUG_ON(cfqd->busy_queues);
+
+ cfq_log(cfqd, "forced_dispatch=%d", dispatched);
+ return dispatched;
+}
+
+static inline bool cfq_slice_used_soon(struct cfq_data *cfqd,
+ struct cfq_queue *cfqq)
+{
+ u64 now = ktime_get_ns();
+
+ /* the queue hasn't finished any request, can't estimate */
+ if (cfq_cfqq_slice_new(cfqq))
+ return true;
+ if (now + cfqd->cfq_slice_idle * cfqq->dispatched > cfqq->slice_end)
+ return true;
+
+ return false;
+}
+
+static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ unsigned int max_dispatch;
+
+ if (cfq_cfqq_must_dispatch(cfqq))
+ return true;
+
+ /*
+ * Drain async requests before we start sync IO
+ */
+ if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_flight[BLK_RW_ASYNC])
+ return false;
+
+ /*
+ * If this is an async queue and we have sync IO in flight, let it wait
+ */
+ if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq))
+ return false;
+
+ max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1);
+ if (cfq_class_idle(cfqq))
+ max_dispatch = 1;
+
+ /*
+ * Does this cfqq already have too much IO in flight?
+ */
+ if (cfqq->dispatched >= max_dispatch) {
+ bool promote_sync = false;
+ /*
+ * idle queue must always only have a single IO in flight
+ */
+ if (cfq_class_idle(cfqq))
+ return false;
+
+ /*
+ * If there is only one sync queue
+ * we can ignore async queue here and give the sync
+ * queue no dispatch limit. The reason is a sync queue can
+ * preempt async queue, limiting the sync queue doesn't make
+ * sense. This is useful for aiostress test.
+ */
+ if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1)
+ promote_sync = true;
+
+ /*
+ * We have other queues, don't allow more IO from this one
+ */
+ if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq) &&
+ !promote_sync)
+ return false;
+
+ /*
+ * Sole queue user, no limit
+ */
+ if (cfqd->busy_queues == 1 || promote_sync)
+ max_dispatch = -1;
+ else
+ /*
+ * Normally we start throttling cfqq when cfq_quantum/2
+ * requests have been dispatched. But we can drive
+ * deeper queue depths at the beginning of slice
+ * subjected to upper limit of cfq_quantum.
+ * */
+ max_dispatch = cfqd->cfq_quantum;
+ }
+
+ /*
+ * Async queues must wait a bit before being allowed dispatch.
+ * We also ramp up the dispatch depth gradually for async IO,
+ * based on the last sync IO we serviced
+ */
+ if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) {
+ u64 last_sync = ktime_get_ns() - cfqd->last_delayed_sync;
+ unsigned int depth;
+
+ depth = div64_u64(last_sync, cfqd->cfq_slice[1]);
+ if (!depth && !cfqq->dispatched)
+ depth = 1;
+ if (depth < max_dispatch)
+ max_dispatch = depth;
+ }
+
+ /*
+ * If we're below the current max, allow a dispatch
+ */
+ return cfqq->dispatched < max_dispatch;
+}
+
+/*
+ * Dispatch a request from cfqq, moving them to the request queue
+ * dispatch list.
+ */
+static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ struct request *rq;
+
+ BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list));
+
+ rq = cfq_check_fifo(cfqq);
+ if (rq)
+ cfq_mark_cfqq_must_dispatch(cfqq);
+
+ if (!cfq_may_dispatch(cfqd, cfqq))
+ return false;
+
+ /*
+ * follow expired path, else get first next available
+ */
+ if (!rq)
+ rq = cfqq->next_rq;
+ else
+ cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq);
+
+ /*
+ * insert request into driver dispatch list
+ */
+ cfq_dispatch_insert(cfqd->queue, rq);
+
+ if (!cfqd->active_cic) {
+ struct cfq_io_cq *cic = RQ_CIC(rq);
+
+ atomic_long_inc(&cic->icq.ioc->refcount);
+ cfqd->active_cic = cic;
+ }
+
+ return true;
+}
+
+/*
+ * Find the cfqq that we need to service and move a request from that to the
+ * dispatch list
+ */
+static int cfq_dispatch_requests(struct request_queue *q, int force)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+ struct cfq_queue *cfqq;
+
+ if (!cfqd->busy_queues)
+ return 0;
+
+ if (unlikely(force))
+ return cfq_forced_dispatch(cfqd);
+
+ cfqq = cfq_select_queue(cfqd);
+ if (!cfqq)
+ return 0;
+
+ /*
+ * Dispatch a request from this cfqq, if it is allowed
+ */
+ if (!cfq_dispatch_request(cfqd, cfqq))
+ return 0;
+
+ cfqq->slice_dispatch++;
+ cfq_clear_cfqq_must_dispatch(cfqq);
+
+ /*
+ * expire an async queue immediately if it has used up its slice. idle
+ * queue always expire after 1 dispatch round.
+ */
+ if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) &&
+ cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) ||
+ cfq_class_idle(cfqq))) {
+ cfqq->slice_end = ktime_get_ns() + 1;
+ cfq_slice_expired(cfqd, 0);
+ }
+
+ cfq_log_cfqq(cfqd, cfqq, "dispatched a request");
+ return 1;
+}
+
+/*
+ * task holds one reference to the queue, dropped when task exits. each rq
+ * in-flight on this queue also holds a reference, dropped when rq is freed.
+ *
+ * Each cfq queue took a reference on the parent group. Drop it now.
+ * queue lock must be held here.
+ */
+static void cfq_put_queue(struct cfq_queue *cfqq)
+{
+ struct cfq_data *cfqd = cfqq->cfqd;
+ struct cfq_group *cfqg;
+
+ BUG_ON(cfqq->ref <= 0);
+
+ cfqq->ref--;
+ if (cfqq->ref)
+ return;
+
+ cfq_log_cfqq(cfqd, cfqq, "put_queue");
+ BUG_ON(rb_first(&cfqq->sort_list));
+ BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]);
+ cfqg = cfqq->cfqg;
+
+ if (unlikely(cfqd->active_queue == cfqq)) {
+ __cfq_slice_expired(cfqd, cfqq, 0);
+ cfq_schedule_dispatch(cfqd);
+ }
+
+ BUG_ON(cfq_cfqq_on_rr(cfqq));
+ kmem_cache_free(cfq_pool, cfqq);
+ cfqg_put(cfqg);
+}
+
+static void cfq_put_cooperator(struct cfq_queue *cfqq)
+{
+ struct cfq_queue *__cfqq, *next;
+
+ /*
+ * If this queue was scheduled to merge with another queue, be
+ * sure to drop the reference taken on that queue (and others in
+ * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs.
+ */
+ __cfqq = cfqq->new_cfqq;
+ while (__cfqq) {
+ if (__cfqq == cfqq) {
+ WARN(1, "cfqq->new_cfqq loop detected\n");
+ break;
+ }
+ next = __cfqq->new_cfqq;
+ cfq_put_queue(__cfqq);
+ __cfqq = next;
+ }
+}
+
+static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ if (unlikely(cfqq == cfqd->active_queue)) {
+ __cfq_slice_expired(cfqd, cfqq, 0);
+ cfq_schedule_dispatch(cfqd);
+ }
+
+ cfq_put_cooperator(cfqq);
+
+ cfq_put_queue(cfqq);
+}
+
+static void cfq_init_icq(struct io_cq *icq)
+{
+ struct cfq_io_cq *cic = icq_to_cic(icq);
+
+ cic->ttime.last_end_request = ktime_get_ns();
+}
+
+static void cfq_exit_icq(struct io_cq *icq)
+{
+ struct cfq_io_cq *cic = icq_to_cic(icq);
+ struct cfq_data *cfqd = cic_to_cfqd(cic);
+
+ if (cic_to_cfqq(cic, false)) {
+ cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, false));
+ cic_set_cfqq(cic, NULL, false);
+ }
+
+ if (cic_to_cfqq(cic, true)) {
+ cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, true));
+ cic_set_cfqq(cic, NULL, true);
+ }
+}
+
+static void cfq_init_prio_data(struct cfq_queue *cfqq, struct cfq_io_cq *cic)
+{
+ struct task_struct *tsk = current;
+ int ioprio_class;
+
+ if (!cfq_cfqq_prio_changed(cfqq))
+ return;
+
+ ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio);
+ switch (ioprio_class) {
+ default:
+ printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
+ case IOPRIO_CLASS_NONE:
+ /*
+ * no prio set, inherit CPU scheduling settings
+ */
+ cfqq->ioprio = task_nice_ioprio(tsk);
+ cfqq->ioprio_class = task_nice_ioclass(tsk);
+ break;
+ case IOPRIO_CLASS_RT:
+ cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio);
+ cfqq->ioprio_class = IOPRIO_CLASS_RT;
+ break;
+ case IOPRIO_CLASS_BE:
+ cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio);
+ cfqq->ioprio_class = IOPRIO_CLASS_BE;
+ break;
+ case IOPRIO_CLASS_IDLE:
+ cfqq->ioprio_class = IOPRIO_CLASS_IDLE;
+ cfqq->ioprio = 7;
+ cfq_clear_cfqq_idle_window(cfqq);
+ break;
+ }
+
+ /*
+ * keep track of original prio settings in case we have to temporarily
+ * elevate the priority of this queue
+ */
+ cfqq->org_ioprio = cfqq->ioprio;
+ cfqq->org_ioprio_class = cfqq->ioprio_class;
+ cfq_clear_cfqq_prio_changed(cfqq);
+}
+
+static void check_ioprio_changed(struct cfq_io_cq *cic, struct bio *bio)
+{
+ int ioprio = cic->icq.ioc->ioprio;
+ struct cfq_data *cfqd = cic_to_cfqd(cic);
+ struct cfq_queue *cfqq;
+
+ /*
+ * Check whether ioprio has changed. The condition may trigger
+ * spuriously on a newly created cic but there's no harm.
+ */
+ if (unlikely(!cfqd) || likely(cic->ioprio == ioprio))
+ return;
+
+ cfqq = cic_to_cfqq(cic, false);
+ if (cfqq) {
+ cfq_put_queue(cfqq);
+ cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic, bio);
+ cic_set_cfqq(cic, cfqq, false);
+ }
+
+ cfqq = cic_to_cfqq(cic, true);
+ if (cfqq)
+ cfq_mark_cfqq_prio_changed(cfqq);
+
+ cic->ioprio = ioprio;
+}
+
+static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ pid_t pid, bool is_sync)
+{
+ RB_CLEAR_NODE(&cfqq->rb_node);
+ RB_CLEAR_NODE(&cfqq->p_node);
+ INIT_LIST_HEAD(&cfqq->fifo);
+
+ cfqq->ref = 0;
+ cfqq->cfqd = cfqd;
+
+ cfq_mark_cfqq_prio_changed(cfqq);
+
+ if (is_sync) {
+ if (!cfq_class_idle(cfqq))
+ cfq_mark_cfqq_idle_window(cfqq);
+ cfq_mark_cfqq_sync(cfqq);
+ }
+ cfqq->pid = pid;
+}
+
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio)
+{
+ struct cfq_data *cfqd = cic_to_cfqd(cic);
+ struct cfq_queue *cfqq;
+ uint64_t serial_nr;
+
+ rcu_read_lock();
+ serial_nr = bio_blkcg(bio)->css.serial_nr;
+ rcu_read_unlock();
+
+ /*
+ * Check whether blkcg has changed. The condition may trigger
+ * spuriously on a newly created cic but there's no harm.
+ */
+ if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr))
+ return;
+
+ /*
+ * Drop reference to queues. New queues will be assigned in new
+ * group upon arrival of fresh requests.
+ */
+ cfqq = cic_to_cfqq(cic, false);
+ if (cfqq) {
+ cfq_log_cfqq(cfqd, cfqq, "changed cgroup");
+ cic_set_cfqq(cic, NULL, false);
+ cfq_put_queue(cfqq);
+ }
+
+ cfqq = cic_to_cfqq(cic, true);
+ if (cfqq) {
+ cfq_log_cfqq(cfqd, cfqq, "changed cgroup");
+ cic_set_cfqq(cic, NULL, true);
+ cfq_put_queue(cfqq);
+ }
+
+ cic->blkcg_serial_nr = serial_nr;
+}
+#else
+static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio)
+{
+}
+#endif /* CONFIG_CFQ_GROUP_IOSCHED */
+
+static struct cfq_queue **
+cfq_async_queue_prio(struct cfq_group *cfqg, int ioprio_class, int ioprio)
+{
+ switch (ioprio_class) {
+ case IOPRIO_CLASS_RT:
+ return &cfqg->async_cfqq[0][ioprio];
+ case IOPRIO_CLASS_NONE:
+ ioprio = IOPRIO_NORM;
+ /* fall through */
+ case IOPRIO_CLASS_BE:
+ return &cfqg->async_cfqq[1][ioprio];
+ case IOPRIO_CLASS_IDLE:
+ return &cfqg->async_idle_cfqq;
+ default:
+ BUG();
+ }
+}
+
+static struct cfq_queue *
+cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
+ struct bio *bio)
+{
+ int ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio);
+ int ioprio = IOPRIO_PRIO_DATA(cic->ioprio);
+ struct cfq_queue **async_cfqq = NULL;
+ struct cfq_queue *cfqq;
+ struct cfq_group *cfqg;
+
+ rcu_read_lock();
+ cfqg = cfq_lookup_cfqg(cfqd, bio_blkcg(bio));
+ if (!cfqg) {
+ cfqq = &cfqd->oom_cfqq;
+ goto out;
+ }
+
+ if (!is_sync) {
+ if (!ioprio_valid(cic->ioprio)) {
+ struct task_struct *tsk = current;
+ ioprio = task_nice_ioprio(tsk);
+ ioprio_class = task_nice_ioclass(tsk);
+ }
+ async_cfqq = cfq_async_queue_prio(cfqg, ioprio_class, ioprio);
+ cfqq = *async_cfqq;
+ if (cfqq)
+ goto out;
+ }
+
+ cfqq = kmem_cache_alloc_node(cfq_pool,
+ GFP_NOWAIT | __GFP_ZERO | __GFP_NOWARN,
+ cfqd->queue->node);
+ if (!cfqq) {
+ cfqq = &cfqd->oom_cfqq;
+ goto out;
+ }
+
+ /* cfq_init_cfqq() assumes cfqq->ioprio_class is initialized. */
+ cfqq->ioprio_class = IOPRIO_CLASS_NONE;
+ cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync);
+ cfq_init_prio_data(cfqq, cic);
+ cfq_link_cfqq_cfqg(cfqq, cfqg);
+ cfq_log_cfqq(cfqd, cfqq, "alloced");
+
+ if (async_cfqq) {
+ /* a new async queue is created, pin and remember */
+ cfqq->ref++;
+ *async_cfqq = cfqq;
+ }
+out:
+ cfqq->ref++;
+ rcu_read_unlock();
+ return cfqq;
+}
+
+static void
+__cfq_update_io_thinktime(struct cfq_ttime *ttime, u64 slice_idle)
+{
+ u64 elapsed = ktime_get_ns() - ttime->last_end_request;
+ elapsed = min(elapsed, 2UL * slice_idle);
+
+ ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8;
+ ttime->ttime_total = div_u64(7*ttime->ttime_total + 256*elapsed, 8);
+ ttime->ttime_mean = div64_ul(ttime->ttime_total + 128,
+ ttime->ttime_samples);
+}
+
+static void
+cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ struct cfq_io_cq *cic)
+{
+ if (cfq_cfqq_sync(cfqq)) {
+ __cfq_update_io_thinktime(&cic->ttime, cfqd->cfq_slice_idle);
+ __cfq_update_io_thinktime(&cfqq->service_tree->ttime,
+ cfqd->cfq_slice_idle);
+ }
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ __cfq_update_io_thinktime(&cfqq->cfqg->ttime, cfqd->cfq_group_idle);
+#endif
+}
+
+static void
+cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ struct request *rq)
+{
+ sector_t sdist = 0;
+ sector_t n_sec = blk_rq_sectors(rq);
+ if (cfqq->last_request_pos) {
+ if (cfqq->last_request_pos < blk_rq_pos(rq))
+ sdist = blk_rq_pos(rq) - cfqq->last_request_pos;
+ else
+ sdist = cfqq->last_request_pos - blk_rq_pos(rq);
+ }
+
+ cfqq->seek_history <<= 1;
+ if (blk_queue_nonrot(cfqd->queue))
+ cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT);
+ else
+ cfqq->seek_history |= (sdist > CFQQ_SEEK_THR);
+}
+
+static inline bool req_noidle(struct request *req)
+{
+ return req_op(req) == REQ_OP_WRITE &&
+ (req->cmd_flags & (REQ_SYNC | REQ_IDLE)) == REQ_SYNC;
+}
+
+/*
+ * Disable idle window if the process thinks too long or seeks so much that
+ * it doesn't matter
+ */
+static void
+cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ struct cfq_io_cq *cic)
+{
+ int old_idle, enable_idle;
+
+ /*
+ * Don't idle for async or idle io prio class
+ */
+ if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq))
+ return;
+
+ enable_idle = old_idle = cfq_cfqq_idle_window(cfqq);
+
+ if (cfqq->queued[0] + cfqq->queued[1] >= 4)
+ cfq_mark_cfqq_deep(cfqq);
+
+ if (cfqq->next_rq && req_noidle(cfqq->next_rq))
+ enable_idle = 0;
+ else if (!atomic_read(&cic->icq.ioc->active_ref) ||
+ !cfqd->cfq_slice_idle ||
+ (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq)))
+ enable_idle = 0;
+ else if (sample_valid(cic->ttime.ttime_samples)) {
+ if (cic->ttime.ttime_mean > cfqd->cfq_slice_idle)
+ enable_idle = 0;
+ else
+ enable_idle = 1;
+ }
+
+ if (old_idle != enable_idle) {
+ cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle);
+ if (enable_idle)
+ cfq_mark_cfqq_idle_window(cfqq);
+ else
+ cfq_clear_cfqq_idle_window(cfqq);
+ }
+}
+
+/*
+ * Check if new_cfqq should preempt the currently active queue. Return 0 for
+ * no or if we aren't sure, a 1 will cause a preempt.
+ */
+static bool
+cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
+ struct request *rq)
+{
+ struct cfq_queue *cfqq;
+
+ cfqq = cfqd->active_queue;
+ if (!cfqq)
+ return false;
+
+ if (cfq_class_idle(new_cfqq))
+ return false;
+
+ if (cfq_class_idle(cfqq))
+ return true;
+
+ /*
+ * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice.
+ */
+ if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq))
+ return false;
+
+ /*
+ * if the new request is sync, but the currently running queue is
+ * not, let the sync request have priority.
+ */
+ if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq) && !cfq_cfqq_must_dispatch(cfqq))
+ return true;
+
+ /*
+ * Treat ancestors of current cgroup the same way as current cgroup.
+ * For anybody else we disallow preemption to guarantee service
+ * fairness among cgroups.
+ */
+ if (!cfqg_is_descendant(cfqq->cfqg, new_cfqq->cfqg))
+ return false;
+
+ if (cfq_slice_used(cfqq))
+ return true;
+
+ /*
+ * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice.
+ */
+ if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq))
+ return true;
+
+ WARN_ON_ONCE(cfqq->ioprio_class != new_cfqq->ioprio_class);
+ /* Allow preemption only if we are idling on sync-noidle tree */
+ if (cfqd->serving_wl_type == SYNC_NOIDLE_WORKLOAD &&
+ cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD &&
+ RB_EMPTY_ROOT(&cfqq->sort_list))
+ return true;
+
+ /*
+ * So both queues are sync. Let the new request get disk time if
+ * it's a metadata request and the current queue is doing regular IO.
+ */
+ if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending)
+ return true;
+
+ /* An idle queue should not be idle now for some reason */
+ if (RB_EMPTY_ROOT(&cfqq->sort_list) && !cfq_should_idle(cfqd, cfqq))
+ return true;
+
+ if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq))
+ return false;
+
+ /*
+ * if this request is as-good as one we would expect from the
+ * current cfqq, let it preempt
+ */
+ if (cfq_rq_close(cfqd, cfqq, rq))
+ return true;
+
+ return false;
+}
+
+/*
+ * cfqq preempts the active queue. if we allowed preempt with no slice left,
+ * let it have half of its nominal slice.
+ */
+static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ enum wl_type_t old_type = cfqq_type(cfqd->active_queue);
+
+ cfq_log_cfqq(cfqd, cfqq, "preempt");
+ cfq_slice_expired(cfqd, 1);
+
+ /*
+ * workload type is changed, don't save slice, otherwise preempt
+ * doesn't happen
+ */
+ if (old_type != cfqq_type(cfqq))
+ cfqq->cfqg->saved_wl_slice = 0;
+
+ /*
+ * Put the new queue at the front of the of the current list,
+ * so we know that it will be selected next.
+ */
+ BUG_ON(!cfq_cfqq_on_rr(cfqq));
+
+ cfq_service_tree_add(cfqd, cfqq, 1);
+
+ cfqq->slice_end = 0;
+ cfq_mark_cfqq_slice_new(cfqq);
+}
+
+/*
+ * Called when a new fs request (rq) is added (to cfqq). Check if there's
+ * something we should do about it
+ */
+static void
+cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ struct request *rq)
+{
+ struct cfq_io_cq *cic = RQ_CIC(rq);
+
+ cfqd->rq_queued++;
+ if (rq->cmd_flags & REQ_PRIO)
+ cfqq->prio_pending++;
+
+ cfq_update_io_thinktime(cfqd, cfqq, cic);
+ cfq_update_io_seektime(cfqd, cfqq, rq);
+ cfq_update_idle_window(cfqd, cfqq, cic);
+
+ cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq);
+
+ if (cfqq == cfqd->active_queue) {
+ /*
+ * Remember that we saw a request from this process, but
+ * don't start queuing just yet. Otherwise we risk seeing lots
+ * of tiny requests, because we disrupt the normal plugging
+ * and merging. If the request is already larger than a single
+ * page, let it rip immediately. For that case we assume that
+ * merging is already done. Ditto for a busy system that
+ * has other work pending, don't risk delaying until the
+ * idle timer unplug to continue working.
+ */
+ if (cfq_cfqq_wait_request(cfqq)) {
+ if (blk_rq_bytes(rq) > PAGE_SIZE ||
+ cfqd->busy_queues > 1) {
+ cfq_del_timer(cfqd, cfqq);
+ cfq_clear_cfqq_wait_request(cfqq);
+ __blk_run_queue(cfqd->queue);
+ } else {
+ cfqg_stats_update_idle_time(cfqq->cfqg);
+ cfq_mark_cfqq_must_dispatch(cfqq);
+ }
+ }
+ } else if (cfq_should_preempt(cfqd, cfqq, rq)) {
+ /*
+ * not the active queue - expire current slice if it is
+ * idle and has expired it's mean thinktime or this new queue
+ * has some old slice time left and is of higher priority or
+ * this new queue is RT and the current one is BE
+ */
+ cfq_preempt_queue(cfqd, cfqq);
+ __blk_run_queue(cfqd->queue);
+ }
+}
+
+static void cfq_insert_request(struct request_queue *q, struct request *rq)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+ struct cfq_queue *cfqq = RQ_CFQQ(rq);
+
+ cfq_log_cfqq(cfqd, cfqq, "insert_request");
+ cfq_init_prio_data(cfqq, RQ_CIC(rq));
+
+ rq->fifo_time = ktime_get_ns() + cfqd->cfq_fifo_expire[rq_is_sync(rq)];
+ list_add_tail(&rq->queuelist, &cfqq->fifo);
+ cfq_add_rq_rb(rq);
+ cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group,
+ rq->cmd_flags);
+ cfq_rq_enqueued(cfqd, cfqq, rq);
+}
+
+/*
+ * Update hw_tag based on peak queue depth over 50 samples under
+ * sufficient load.
+ */
+static void cfq_update_hw_tag(struct cfq_data *cfqd)
+{
+ struct cfq_queue *cfqq = cfqd->active_queue;
+
+ if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth)
+ cfqd->hw_tag_est_depth = cfqd->rq_in_driver;
+
+ if (cfqd->hw_tag == 1)
+ return;
+
+ if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN &&
+ cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN)
+ return;
+
+ /*
+ * If active queue hasn't enough requests and can idle, cfq might not
+ * dispatch sufficient requests to hardware. Don't zero hw_tag in this
+ * case
+ */
+ if (cfqq && cfq_cfqq_idle_window(cfqq) &&
+ cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] <
+ CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN)
+ return;
+
+ if (cfqd->hw_tag_samples++ < 50)
+ return;
+
+ if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN)
+ cfqd->hw_tag = 1;
+ else
+ cfqd->hw_tag = 0;
+}
+
+static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ struct cfq_io_cq *cic = cfqd->active_cic;
+ u64 now = ktime_get_ns();
+
+ /* If the queue already has requests, don't wait */
+ if (!RB_EMPTY_ROOT(&cfqq->sort_list))
+ return false;
+
+ /* If there are other queues in the group, don't wait */
+ if (cfqq->cfqg->nr_cfqq > 1)
+ return false;
+
+ /* the only queue in the group, but think time is big */
+ if (cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true))
+ return false;
+
+ if (cfq_slice_used(cfqq))
+ return true;
+
+ /* if slice left is less than think time, wait busy */
+ if (cic && sample_valid(cic->ttime.ttime_samples)
+ && (cfqq->slice_end - now < cic->ttime.ttime_mean))
+ return true;
+
+ /*
+ * If think times is less than a jiffy than ttime_mean=0 and above
+ * will not be true. It might happen that slice has not expired yet
+ * but will expire soon (4-5 ns) during select_queue(). To cover the
+ * case where think time is less than a jiffy, mark the queue wait
+ * busy if only 1 jiffy is left in the slice.
+ */
+ if (cfqq->slice_end - now <= jiffies_to_nsecs(1))
+ return true;
+
+ return false;
+}
+
+static void cfq_completed_request(struct request_queue *q, struct request *rq)
+{
+ struct cfq_queue *cfqq = RQ_CFQQ(rq);
+ struct cfq_data *cfqd = cfqq->cfqd;
+ const int sync = rq_is_sync(rq);
+ u64 now = ktime_get_ns();
+
+ cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", req_noidle(rq));
+
+ cfq_update_hw_tag(cfqd);
+
+ WARN_ON(!cfqd->rq_in_driver);
+ WARN_ON(!cfqq->dispatched);
+ cfqd->rq_in_driver--;
+ cfqq->dispatched--;
+ (RQ_CFQG(rq))->dispatched--;
+ cfqg_stats_update_completion(cfqq->cfqg, rq_start_time_ns(rq),
+ rq_io_start_time_ns(rq), rq->cmd_flags);
+
+ cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
+
+ if (sync) {
+ struct cfq_rb_root *st;
+
+ RQ_CIC(rq)->ttime.last_end_request = now;
+
+ if (cfq_cfqq_on_rr(cfqq))
+ st = cfqq->service_tree;
+ else
+ st = st_for(cfqq->cfqg, cfqq_class(cfqq),
+ cfqq_type(cfqq));
+
+ st->ttime.last_end_request = now;
+ /*
+ * We have to do this check in jiffies since start_time is in
+ * jiffies and it is not trivial to convert to ns. If
+ * cfq_fifo_expire[1] ever comes close to 1 jiffie, this test
+ * will become problematic but so far we are fine (the default
+ * is 128 ms).
+ */
+ if (!time_after(rq->start_time +
+ nsecs_to_jiffies(cfqd->cfq_fifo_expire[1]),
+ jiffies))
+ cfqd->last_delayed_sync = now;
+ }
+
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ cfqq->cfqg->ttime.last_end_request = now;
+#endif
+
+ /*
+ * If this is the active queue, check if it needs to be expired,
+ * or if we want to idle in case it has no pending requests.
+ */
+ if (cfqd->active_queue == cfqq) {
+ const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list);
+
+ if (cfq_cfqq_slice_new(cfqq)) {
+ cfq_set_prio_slice(cfqd, cfqq);
+ cfq_clear_cfqq_slice_new(cfqq);
+ }
+
+ /*
+ * Should we wait for next request to come in before we expire
+ * the queue.
+ */
+ if (cfq_should_wait_busy(cfqd, cfqq)) {
+ u64 extend_sl = cfqd->cfq_slice_idle;
+ if (!cfqd->cfq_slice_idle)
+ extend_sl = cfqd->cfq_group_idle;
+ cfqq->slice_end = now + extend_sl;
+ cfq_mark_cfqq_wait_busy(cfqq);
+ cfq_log_cfqq(cfqd, cfqq, "will busy wait");
+ }
+
+ /*
+ * Idling is not enabled on:
+ * - expired queues
+ * - idle-priority queues
+ * - async queues
+ * - queues with still some requests queued
+ * - when there is a close cooperator
+ */
+ if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq))
+ cfq_slice_expired(cfqd, 1);
+ else if (sync && cfqq_empty &&
+ !cfq_close_cooperator(cfqd, cfqq)) {
+ cfq_arm_slice_timer(cfqd);
+ }
+ }
+
+ if (!cfqd->rq_in_driver)
+ cfq_schedule_dispatch(cfqd);
+}
+
+static void cfqq_boost_on_prio(struct cfq_queue *cfqq, unsigned int op)
+{
+ /*
+ * If REQ_PRIO is set, boost class and prio level, if it's below
+ * BE/NORM. If prio is not set, restore the potentially boosted
+ * class/prio level.
+ */
+ if (!(op & REQ_PRIO)) {
+ cfqq->ioprio_class = cfqq->org_ioprio_class;
+ cfqq->ioprio = cfqq->org_ioprio;
+ } else {
+ if (cfq_class_idle(cfqq))
+ cfqq->ioprio_class = IOPRIO_CLASS_BE;
+ if (cfqq->ioprio > IOPRIO_NORM)
+ cfqq->ioprio = IOPRIO_NORM;
+ }
+}
+
+static inline int __cfq_may_queue(struct cfq_queue *cfqq)
+{
+ if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) {
+ cfq_mark_cfqq_must_alloc_slice(cfqq);
+ return ELV_MQUEUE_MUST;
+ }
+
+ return ELV_MQUEUE_MAY;
+}
+
+static int cfq_may_queue(struct request_queue *q, unsigned int op)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+ struct task_struct *tsk = current;
+ struct cfq_io_cq *cic;
+ struct cfq_queue *cfqq;
+
+ /*
+ * don't force setup of a queue from here, as a call to may_queue
+ * does not necessarily imply that a request actually will be queued.
+ * so just lookup a possibly existing queue, or return 'may queue'
+ * if that fails
+ */
+ cic = cfq_cic_lookup(cfqd, tsk->io_context);
+ if (!cic)
+ return ELV_MQUEUE_MAY;
+
+ cfqq = cic_to_cfqq(cic, op_is_sync(op));
+ if (cfqq) {
+ cfq_init_prio_data(cfqq, cic);
+ cfqq_boost_on_prio(cfqq, op);
+
+ return __cfq_may_queue(cfqq);
+ }
+
+ return ELV_MQUEUE_MAY;
+}
+
+/*
+ * queue lock held here
+ */
+static void cfq_put_request(struct request *rq)
+{
+ struct cfq_queue *cfqq = RQ_CFQQ(rq);
+
+ if (cfqq) {
+ const int rw = rq_data_dir(rq);
+
+ BUG_ON(!cfqq->allocated[rw]);
+ cfqq->allocated[rw]--;
+
+ /* Put down rq reference on cfqg */
+ cfqg_put(RQ_CFQG(rq));
+ rq->elv.priv[0] = NULL;
+ rq->elv.priv[1] = NULL;
+
+ cfq_put_queue(cfqq);
+ }
+}
+
+static struct cfq_queue *
+cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_cq *cic,
+ struct cfq_queue *cfqq)
+{
+ cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq);
+ cic_set_cfqq(cic, cfqq->new_cfqq, 1);
+ cfq_mark_cfqq_coop(cfqq->new_cfqq);
+ cfq_put_queue(cfqq);
+ return cic_to_cfqq(cic, 1);
+}
+
+/*
+ * Returns NULL if a new cfqq should be allocated, or the old cfqq if this
+ * was the last process referring to said cfqq.
+ */
+static struct cfq_queue *
+split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq)
+{
+ if (cfqq_process_refs(cfqq) == 1) {
+ cfqq->pid = current->pid;
+ cfq_clear_cfqq_coop(cfqq);
+ cfq_clear_cfqq_split_coop(cfqq);
+ return cfqq;
+ }
+
+ cic_set_cfqq(cic, NULL, 1);
+
+ cfq_put_cooperator(cfqq);
+
+ cfq_put_queue(cfqq);
+ return NULL;
+}
+/*
+ * Allocate cfq data structures associated with this request.
+ */
+static int
+cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio,
+ gfp_t gfp_mask)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+ struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq);
+ const int rw = rq_data_dir(rq);
+ const bool is_sync = rq_is_sync(rq);
+ struct cfq_queue *cfqq;
+
+ spin_lock_irq(q->queue_lock);
+
+ check_ioprio_changed(cic, bio);
+ check_blkcg_changed(cic, bio);
+new_queue:
+ cfqq = cic_to_cfqq(cic, is_sync);
+ if (!cfqq || cfqq == &cfqd->oom_cfqq) {
+ if (cfqq)
+ cfq_put_queue(cfqq);
+ cfqq = cfq_get_queue(cfqd, is_sync, cic, bio);
+ cic_set_cfqq(cic, cfqq, is_sync);
+ } else {
+ /*
+ * If the queue was seeky for too long, break it apart.
+ */
+ if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) {
+ cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq");
+ cfqq = split_cfqq(cic, cfqq);
+ if (!cfqq)
+ goto new_queue;
+ }
+
+ /*
+ * Check to see if this queue is scheduled to merge with
+ * another, closely cooperating queue. The merging of
+ * queues happens here as it must be done in process context.
+ * The reference on new_cfqq was taken in merge_cfqqs.
+ */
+ if (cfqq->new_cfqq)
+ cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq);
+ }
+
+ cfqq->allocated[rw]++;
+
+ cfqq->ref++;
+ cfqg_get(cfqq->cfqg);
+ rq->elv.priv[0] = cfqq;
+ rq->elv.priv[1] = cfqq->cfqg;
+ spin_unlock_irq(q->queue_lock);
+
+ return 0;
+}
+
+static void cfq_kick_queue(struct work_struct *work)
+{
+ struct cfq_data *cfqd =
+ container_of(work, struct cfq_data, unplug_work);
+ struct request_queue *q = cfqd->queue;
+
+ spin_lock_irq(q->queue_lock);
+ __blk_run_queue(cfqd->queue);
+ spin_unlock_irq(q->queue_lock);
+}
+
+/*
+ * Timer running if the active_queue is currently idling inside its time slice
+ */
+static enum hrtimer_restart cfq_idle_slice_timer(struct hrtimer *timer)
+{
+ struct cfq_data *cfqd = container_of(timer, struct cfq_data,
+ idle_slice_timer);
+ struct cfq_queue *cfqq;
+ unsigned long flags;
+ int timed_out = 1;
+
+ cfq_log(cfqd, "idle timer fired");
+
+ spin_lock_irqsave(cfqd->queue->queue_lock, flags);
+
+ cfqq = cfqd->active_queue;
+ if (cfqq) {
+ timed_out = 0;
+
+ /*
+ * We saw a request before the queue expired, let it through
+ */
+ if (cfq_cfqq_must_dispatch(cfqq))
+ goto out_kick;
+
+ /*
+ * expired
+ */
+ if (cfq_slice_used(cfqq))
+ goto expire;
+
+ /*
+ * only expire and reinvoke request handler, if there are
+ * other queues with pending requests
+ */
+ if (!cfqd->busy_queues)
+ goto out_cont;
+
+ /*
+ * not expired and it has a request pending, let it dispatch
+ */
+ if (!RB_EMPTY_ROOT(&cfqq->sort_list))
+ goto out_kick;
+
+ /*
+ * Queue depth flag is reset only when the idle didn't succeed
+ */
+ cfq_clear_cfqq_deep(cfqq);
+ }
+expire:
+ cfq_slice_expired(cfqd, timed_out);
+out_kick:
+ cfq_schedule_dispatch(cfqd);
+out_cont:
+ spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
+ return HRTIMER_NORESTART;
+}
+
+static void cfq_shutdown_timer_wq(struct cfq_data *cfqd)
+{
+ hrtimer_cancel(&cfqd->idle_slice_timer);
+ cancel_work_sync(&cfqd->unplug_work);
+}
+
+static void cfq_exit_queue(struct elevator_queue *e)
+{
+ struct cfq_data *cfqd = e->elevator_data;
+ struct request_queue *q = cfqd->queue;
+
+ cfq_shutdown_timer_wq(cfqd);
+
+ spin_lock_irq(q->queue_lock);
+
+ if (cfqd->active_queue)
+ __cfq_slice_expired(cfqd, cfqd->active_queue, 0);
+
+ spin_unlock_irq(q->queue_lock);
+
+ cfq_shutdown_timer_wq(cfqd);
+
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ blkcg_deactivate_policy(q, &blkcg_policy_cfq);
+#else
+ kfree(cfqd->root_group);
+#endif
+ kfree(cfqd);
+}
+
+static int cfq_init_queue(struct request_queue *q, struct elevator_type *e)
+{
+ struct cfq_data *cfqd;
+ struct blkcg_gq *blkg __maybe_unused;
+ int i, ret;
+ struct elevator_queue *eq;
+
+ eq = elevator_alloc(q, e);
+ if (!eq)
+ return -ENOMEM;
+
+ cfqd = kzalloc_node(sizeof(*cfqd), GFP_KERNEL, q->node);
+ if (!cfqd) {
+ kobject_put(&eq->kobj);
+ return -ENOMEM;
+ }
+ eq->elevator_data = cfqd;
+
+ cfqd->queue = q;
+ spin_lock_irq(q->queue_lock);
+ q->elevator = eq;
+ spin_unlock_irq(q->queue_lock);
+
+ /* Init root service tree */
+ cfqd->grp_service_tree = CFQ_RB_ROOT;
+
+ /* Init root group and prefer root group over other groups by default */
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ ret = blkcg_activate_policy(q, &blkcg_policy_cfq);
+ if (ret)
+ goto out_free;
+
+ cfqd->root_group = blkg_to_cfqg(q->root_blkg);
+#else
+ ret = -ENOMEM;
+ cfqd->root_group = kzalloc_node(sizeof(*cfqd->root_group),
+ GFP_KERNEL, cfqd->queue->node);
+ if (!cfqd->root_group)
+ goto out_free;
+
+ cfq_init_cfqg_base(cfqd->root_group);
+ cfqd->root_group->weight = 2 * CFQ_WEIGHT_LEGACY_DFL;
+ cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_LEGACY_DFL;
+#endif
+
+ /*
+ * Not strictly needed (since RB_ROOT just clears the node and we
+ * zeroed cfqd on alloc), but better be safe in case someone decides
+ * to add magic to the rb code
+ */
+ for (i = 0; i < CFQ_PRIO_LISTS; i++)
+ cfqd->prio_trees[i] = RB_ROOT;
+
+ /*
+ * Our fallback cfqq if cfq_get_queue() runs into OOM issues.
+ * Grab a permanent reference to it, so that the normal code flow
+ * will not attempt to free it. oom_cfqq is linked to root_group
+ * but shouldn't hold a reference as it'll never be unlinked. Lose
+ * the reference from linking right away.
+ */
+ cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0);
+ cfqd->oom_cfqq.ref++;
+
+ spin_lock_irq(q->queue_lock);
+ cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, cfqd->root_group);
+ cfqg_put(cfqd->root_group);
+ spin_unlock_irq(q->queue_lock);
+
+ hrtimer_init(&cfqd->idle_slice_timer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL);
+ cfqd->idle_slice_timer.function = cfq_idle_slice_timer;
+
+ INIT_WORK(&cfqd->unplug_work, cfq_kick_queue);
+
+ cfqd->cfq_quantum = cfq_quantum;
+ cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0];
+ cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1];
+ cfqd->cfq_back_max = cfq_back_max;
+ cfqd->cfq_back_penalty = cfq_back_penalty;
+ cfqd->cfq_slice[0] = cfq_slice_async;
+ cfqd->cfq_slice[1] = cfq_slice_sync;
+ cfqd->cfq_target_latency = cfq_target_latency;
+ cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
+ cfqd->cfq_slice_idle = cfq_slice_idle;
+ cfqd->cfq_group_idle = cfq_group_idle;
+ cfqd->cfq_latency = 1;
+ cfqd->hw_tag = -1;
+ /*
+ * we optimistically start assuming sync ops weren't delayed in last
+ * second, in order to have larger depth for async operations.
+ */
+ cfqd->last_delayed_sync = ktime_get_ns() - NSEC_PER_SEC;
+ return 0;
+
+out_free:
+ kfree(cfqd);
+ kobject_put(&eq->kobj);
+ return ret;
+}
+
+static void cfq_registered_queue(struct request_queue *q)
+{
+ struct elevator_queue *e = q->elevator;
+ struct cfq_data *cfqd = e->elevator_data;
+
+ /*
+ * Default to IOPS mode with no idling for SSDs
+ */
+ if (blk_queue_nonrot(q))
+ cfqd->cfq_slice_idle = 0;
+ wbt_disable_default(q);
+}
+
+/*
+ * sysfs parts below -->
+ */
+static ssize_t
+cfq_var_show(unsigned int var, char *page)
+{
+ return sprintf(page, "%u\n", var);
+}
+
+static void
+cfq_var_store(unsigned int *var, const char *page)
+{
+ char *p = (char *) page;
+
+ *var = simple_strtoul(p, &p, 10);
+}
+
+#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
+static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+{ \
+ struct cfq_data *cfqd = e->elevator_data; \
+ u64 __data = __VAR; \
+ if (__CONV) \
+ __data = div_u64(__data, NSEC_PER_MSEC); \
+ return cfq_var_show(__data, (page)); \
+}
+SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0);
+SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1);
+SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1);
+SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0);
+SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0);
+SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1);
+SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1);
+SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1);
+SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1);
+SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
+SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0);
+SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1);
+#undef SHOW_FUNCTION
+
+#define USEC_SHOW_FUNCTION(__FUNC, __VAR) \
+static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+{ \
+ struct cfq_data *cfqd = e->elevator_data; \
+ u64 __data = __VAR; \
+ __data = div_u64(__data, NSEC_PER_USEC); \
+ return cfq_var_show(__data, (page)); \
+}
+USEC_SHOW_FUNCTION(cfq_slice_idle_us_show, cfqd->cfq_slice_idle);
+USEC_SHOW_FUNCTION(cfq_group_idle_us_show, cfqd->cfq_group_idle);
+USEC_SHOW_FUNCTION(cfq_slice_sync_us_show, cfqd->cfq_slice[1]);
+USEC_SHOW_FUNCTION(cfq_slice_async_us_show, cfqd->cfq_slice[0]);
+USEC_SHOW_FUNCTION(cfq_target_latency_us_show, cfqd->cfq_target_latency);
+#undef USEC_SHOW_FUNCTION
+
+#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
+{ \
+ struct cfq_data *cfqd = e->elevator_data; \
+ unsigned int __data, __min = (MIN), __max = (MAX); \
+ \
+ cfq_var_store(&__data, (page)); \
+ if (__data < __min) \
+ __data = __min; \
+ else if (__data > __max) \
+ __data = __max; \
+ if (__CONV) \
+ *(__PTR) = (u64)__data * NSEC_PER_MSEC; \
+ else \
+ *(__PTR) = __data; \
+ return count; \
+}
+STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0);
+STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1,
+ UINT_MAX, 1);
+STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1,
+ UINT_MAX, 1);
+STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0);
+STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1,
+ UINT_MAX, 0);
+STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1);
+STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1);
+STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1);
+STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1);
+STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1,
+ UINT_MAX, 0);
+STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0);
+STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX, 1);
+#undef STORE_FUNCTION
+
+#define USEC_STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
+{ \
+ struct cfq_data *cfqd = e->elevator_data; \
+ unsigned int __data, __min = (MIN), __max = (MAX); \
+ \
+ cfq_var_store(&__data, (page)); \
+ if (__data < __min) \
+ __data = __min; \
+ else if (__data > __max) \
+ __data = __max; \
+ *(__PTR) = (u64)__data * NSEC_PER_USEC; \
+ return count; \
+}
+USEC_STORE_FUNCTION(cfq_slice_idle_us_store, &cfqd->cfq_slice_idle, 0, UINT_MAX);
+USEC_STORE_FUNCTION(cfq_group_idle_us_store, &cfqd->cfq_group_idle, 0, UINT_MAX);
+USEC_STORE_FUNCTION(cfq_slice_sync_us_store, &cfqd->cfq_slice[1], 1, UINT_MAX);
+USEC_STORE_FUNCTION(cfq_slice_async_us_store, &cfqd->cfq_slice[0], 1, UINT_MAX);
+USEC_STORE_FUNCTION(cfq_target_latency_us_store, &cfqd->cfq_target_latency, 1, UINT_MAX);
+#undef USEC_STORE_FUNCTION
+
+#define CFQ_ATTR(name) \
+ __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store)
+
+static struct elv_fs_entry cfq_attrs[] = {
+ CFQ_ATTR(quantum),
+ CFQ_ATTR(fifo_expire_sync),
+ CFQ_ATTR(fifo_expire_async),
+ CFQ_ATTR(back_seek_max),
+ CFQ_ATTR(back_seek_penalty),
+ CFQ_ATTR(slice_sync),
+ CFQ_ATTR(slice_sync_us),
+ CFQ_ATTR(slice_async),
+ CFQ_ATTR(slice_async_us),
+ CFQ_ATTR(slice_async_rq),
+ CFQ_ATTR(slice_idle),
+ CFQ_ATTR(slice_idle_us),
+ CFQ_ATTR(group_idle),
+ CFQ_ATTR(group_idle_us),
+ CFQ_ATTR(low_latency),
+ CFQ_ATTR(target_latency),
+ CFQ_ATTR(target_latency_us),
+ __ATTR_NULL
+};
+
+static struct elevator_type iosched_cfq = {
+ .ops.sq = {
+ .elevator_merge_fn = cfq_merge,
+ .elevator_merged_fn = cfq_merged_request,
+ .elevator_merge_req_fn = cfq_merged_requests,
+ .elevator_allow_bio_merge_fn = cfq_allow_bio_merge,
+ .elevator_allow_rq_merge_fn = cfq_allow_rq_merge,
+ .elevator_bio_merged_fn = cfq_bio_merged,
+ .elevator_dispatch_fn = cfq_dispatch_requests,
+ .elevator_add_req_fn = cfq_insert_request,
+ .elevator_activate_req_fn = cfq_activate_request,
+ .elevator_deactivate_req_fn = cfq_deactivate_request,
+ .elevator_completed_req_fn = cfq_completed_request,
+ .elevator_former_req_fn = elv_rb_former_request,
+ .elevator_latter_req_fn = elv_rb_latter_request,
+ .elevator_init_icq_fn = cfq_init_icq,
+ .elevator_exit_icq_fn = cfq_exit_icq,
+ .elevator_set_req_fn = cfq_set_request,
+ .elevator_put_req_fn = cfq_put_request,
+ .elevator_may_queue_fn = cfq_may_queue,
+ .elevator_init_fn = cfq_init_queue,
+ .elevator_exit_fn = cfq_exit_queue,
+ .elevator_registered_fn = cfq_registered_queue,
+ },
+ .icq_size = sizeof(struct cfq_io_cq),
+ .icq_align = __alignof__(struct cfq_io_cq),
+ .elevator_attrs = cfq_attrs,
+ .elevator_name = "cfq",
+ .elevator_owner = THIS_MODULE,
+};
+
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+static struct blkcg_policy blkcg_policy_cfq = {
+ .dfl_cftypes = cfq_blkcg_files,
+ .legacy_cftypes = cfq_blkcg_legacy_files,
+
+ .cpd_alloc_fn = cfq_cpd_alloc,
+ .cpd_init_fn = cfq_cpd_init,
+ .cpd_free_fn = cfq_cpd_free,
+ .cpd_bind_fn = cfq_cpd_bind,
+
+ .pd_alloc_fn = cfq_pd_alloc,
+ .pd_init_fn = cfq_pd_init,
+ .pd_offline_fn = cfq_pd_offline,
+ .pd_free_fn = cfq_pd_free,
+ .pd_reset_stats_fn = cfq_pd_reset_stats,
+};
+#endif
+
+static int __init cfq_init(void)
+{
+ int ret;
+
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ ret = blkcg_policy_register(&blkcg_policy_cfq);
+ if (ret)
+ return ret;
+#else
+ cfq_group_idle = 0;
+#endif
+
+ ret = -ENOMEM;
+ cfq_pool = KMEM_CACHE(cfq_queue, 0);
+ if (!cfq_pool)
+ goto err_pol_unreg;
+
+ ret = elv_register(&iosched_cfq);
+ if (ret)
+ goto err_free_pool;
+
+ return 0;
+
+err_free_pool:
+ kmem_cache_destroy(cfq_pool);
+err_pol_unreg:
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ blkcg_policy_unregister(&blkcg_policy_cfq);
+#endif
+ return ret;
+}
+
+static void __exit cfq_exit(void)
+{
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+ blkcg_policy_unregister(&blkcg_policy_cfq);
+#endif
+ elv_unregister(&iosched_cfq);
+ kmem_cache_destroy(cfq_pool);
+}
+
+module_init(cfq_init);
+module_exit(cfq_exit);
+
+MODULE_AUTHOR("Jens Axboe");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler");
diff --git a/src/kernel/linux/v4.14/block/cmdline-parser.c b/src/kernel/linux/v4.14/block/cmdline-parser.c
new file mode 100644
index 0000000..f2a1457
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/cmdline-parser.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Parse command line, get partition information
+ *
+ * Written by Cai Zhiyong <caizhiyong@huawei.com>
+ *
+ */
+#include <linux/export.h>
+#include <linux/cmdline-parser.h>
+
+static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
+{
+ int ret = 0;
+ struct cmdline_subpart *new_subpart;
+
+ *subpart = NULL;
+
+ new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL);
+ if (!new_subpart)
+ return -ENOMEM;
+
+ if (*partdef == '-') {
+ new_subpart->size = (sector_t)(~0ULL);
+ partdef++;
+ } else {
+ new_subpart->size = (sector_t)memparse(partdef, &partdef);
+ if (new_subpart->size < (sector_t)PAGE_SIZE) {
+ pr_warn("cmdline partition size is invalid.");
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ if (*partdef == '@') {
+ partdef++;
+ new_subpart->from = (sector_t)memparse(partdef, &partdef);
+ } else {
+ new_subpart->from = (sector_t)(~0ULL);
+ }
+
+ if (*partdef == '(') {
+ int length;
+ char *next = strchr(++partdef, ')');
+
+ if (!next) {
+ pr_warn("cmdline partition format is invalid.");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ length = min_t(int, next - partdef,
+ sizeof(new_subpart->name) - 1);
+ strncpy(new_subpart->name, partdef, length);
+ new_subpart->name[length] = '\0';
+
+ partdef = ++next;
+ } else
+ new_subpart->name[0] = '\0';
+
+ new_subpart->flags = 0;
+
+ if (!strncmp(partdef, "ro", 2)) {
+ new_subpart->flags |= PF_RDONLY;
+ partdef += 2;
+ }
+
+ if (!strncmp(partdef, "lk", 2)) {
+ new_subpart->flags |= PF_POWERUP_LOCK;
+ partdef += 2;
+ }
+
+ *subpart = new_subpart;
+ return 0;
+fail:
+ kfree(new_subpart);
+ return ret;
+}
+
+static void free_subpart(struct cmdline_parts *parts)
+{
+ struct cmdline_subpart *subpart;
+
+ while (parts->subpart) {
+ subpart = parts->subpart;
+ parts->subpart = subpart->next_subpart;
+ kfree(subpart);
+ }
+}
+
+static int parse_parts(struct cmdline_parts **parts, const char *bdevdef)
+{
+ int ret = -EINVAL;
+ char *next;
+ int length;
+ struct cmdline_subpart **next_subpart;
+ struct cmdline_parts *newparts;
+ char buf[BDEVNAME_SIZE + 32 + 4];
+
+ *parts = NULL;
+
+ newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL);
+ if (!newparts)
+ return -ENOMEM;
+
+ next = strchr(bdevdef, ':');
+ if (!next) {
+ pr_warn("cmdline partition has no block device.");
+ goto fail;
+ }
+
+ length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1);
+ strncpy(newparts->name, bdevdef, length);
+ newparts->name[length] = '\0';
+ newparts->nr_subparts = 0;
+
+ next_subpart = &newparts->subpart;
+
+ while (next && *(++next)) {
+ bdevdef = next;
+ next = strchr(bdevdef, ',');
+
+ length = (!next) ? (sizeof(buf) - 1) :
+ min_t(int, next - bdevdef, sizeof(buf) - 1);
+
+ strncpy(buf, bdevdef, length);
+ buf[length] = '\0';
+
+ ret = parse_subpart(next_subpart, buf);
+ if (ret)
+ goto fail;
+
+ newparts->nr_subparts++;
+ next_subpart = &(*next_subpart)->next_subpart;
+ }
+
+ if (!newparts->subpart) {
+ pr_warn("cmdline partition has no valid partition.");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ *parts = newparts;
+
+ return 0;
+fail:
+ free_subpart(newparts);
+ kfree(newparts);
+ return ret;
+}
+
+void cmdline_parts_free(struct cmdline_parts **parts)
+{
+ struct cmdline_parts *next_parts;
+
+ while (*parts) {
+ next_parts = (*parts)->next_parts;
+ free_subpart(*parts);
+ kfree(*parts);
+ *parts = next_parts;
+ }
+}
+EXPORT_SYMBOL(cmdline_parts_free);
+
+int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline)
+{
+ int ret;
+ char *buf;
+ char *pbuf;
+ char *next;
+ struct cmdline_parts **next_parts;
+
+ *parts = NULL;
+
+ next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ next_parts = parts;
+
+ while (next && *pbuf) {
+ next = strchr(pbuf, ';');
+ if (next)
+ *next = '\0';
+
+ ret = parse_parts(next_parts, pbuf);
+ if (ret)
+ goto fail;
+
+ if (next)
+ pbuf = ++next;
+
+ next_parts = &(*next_parts)->next_parts;
+ }
+
+ if (!*parts) {
+ pr_warn("cmdline partition has no valid partition.");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ ret = 0;
+done:
+ kfree(buf);
+ return ret;
+
+fail:
+ cmdline_parts_free(parts);
+ goto done;
+}
+EXPORT_SYMBOL(cmdline_parts_parse);
+
+struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
+ const char *bdev)
+{
+ while (parts && strncmp(bdev, parts->name, sizeof(parts->name)))
+ parts = parts->next_parts;
+ return parts;
+}
+EXPORT_SYMBOL(cmdline_parts_find);
+
+/*
+ * add_part()
+ * 0 success.
+ * 1 can not add so many partitions.
+ */
+int cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
+ int slot,
+ int (*add_part)(int, struct cmdline_subpart *, void *),
+ void *param)
+{
+ sector_t from = 0;
+ struct cmdline_subpart *subpart;
+
+ for (subpart = parts->subpart; subpart;
+ subpart = subpart->next_subpart, slot++) {
+ if (subpart->from == (sector_t)(~0ULL))
+ subpart->from = from;
+ else
+ from = subpart->from;
+
+ if (from >= disk_size)
+ break;
+
+ if (subpart->size > (disk_size - from))
+ subpart->size = disk_size - from;
+
+ from += subpart->size;
+
+ if (add_part(slot, subpart, param))
+ break;
+ }
+
+ return slot;
+}
+EXPORT_SYMBOL(cmdline_parts_set);
diff --git a/src/kernel/linux/v4.14/block/compat_ioctl.c b/src/kernel/linux/v4.14/block/compat_ioctl.c
new file mode 100644
index 0000000..6490b27
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/compat_ioctl.c
@@ -0,0 +1,422 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/blkdev.h>
+#include <linux/blkpg.h>
+#include <linux/blktrace_api.h>
+#include <linux/cdrom.h>
+#include <linux/compat.h>
+#include <linux/elevator.h>
+#include <linux/hdreg.h>
+#include <linux/pr.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+static int compat_put_ushort(unsigned long arg, unsigned short val)
+{
+ return put_user(val, (unsigned short __user *)compat_ptr(arg));
+}
+
+static int compat_put_int(unsigned long arg, int val)
+{
+ return put_user(val, (compat_int_t __user *)compat_ptr(arg));
+}
+
+static int compat_put_uint(unsigned long arg, unsigned int val)
+{
+ return put_user(val, (compat_uint_t __user *)compat_ptr(arg));
+}
+
+static int compat_put_long(unsigned long arg, long val)
+{
+ return put_user(val, (compat_long_t __user *)compat_ptr(arg));
+}
+
+static int compat_put_ulong(unsigned long arg, compat_ulong_t val)
+{
+ return put_user(val, (compat_ulong_t __user *)compat_ptr(arg));
+}
+
+static int compat_put_u64(unsigned long arg, u64 val)
+{
+ return put_user(val, (compat_u64 __user *)compat_ptr(arg));
+}
+
+struct compat_hd_geometry {
+ unsigned char heads;
+ unsigned char sectors;
+ unsigned short cylinders;
+ u32 start;
+};
+
+static int compat_hdio_getgeo(struct gendisk *disk, struct block_device *bdev,
+ struct compat_hd_geometry __user *ugeo)
+{
+ struct hd_geometry geo;
+ int ret;
+
+ if (!ugeo)
+ return -EINVAL;
+ if (!disk->fops->getgeo)
+ return -ENOTTY;
+
+ memset(&geo, 0, sizeof(geo));
+ /*
+ * We need to set the startsect first, the driver may
+ * want to override it.
+ */
+ geo.start = get_start_sect(bdev);
+ ret = disk->fops->getgeo(bdev, &geo);
+ if (ret)
+ return ret;
+
+ ret = copy_to_user(ugeo, &geo, 4);
+ ret |= put_user(geo.start, &ugeo->start);
+ if (ret)
+ ret = -EFAULT;
+
+ return ret;
+}
+
+static int compat_hdio_ioctl(struct block_device *bdev, fmode_t mode,
+ unsigned int cmd, unsigned long arg)
+{
+ unsigned long __user *p;
+ int error;
+
+ p = compat_alloc_user_space(sizeof(unsigned long));
+ error = __blkdev_driver_ioctl(bdev, mode,
+ cmd, (unsigned long)p);
+ if (error == 0) {
+ unsigned int __user *uvp = compat_ptr(arg);
+ unsigned long v;
+ if (get_user(v, p) || put_user(v, uvp))
+ error = -EFAULT;
+ }
+ return error;
+}
+
+struct compat_cdrom_read_audio {
+ union cdrom_addr addr;
+ u8 addr_format;
+ compat_int_t nframes;
+ compat_caddr_t buf;
+};
+
+struct compat_cdrom_generic_command {
+ unsigned char cmd[CDROM_PACKET_SIZE];
+ compat_caddr_t buffer;
+ compat_uint_t buflen;
+ compat_int_t stat;
+ compat_caddr_t sense;
+ unsigned char data_direction;
+ compat_int_t quiet;
+ compat_int_t timeout;
+ compat_caddr_t reserved[1];
+};
+
+static int compat_cdrom_read_audio(struct block_device *bdev, fmode_t mode,
+ unsigned int cmd, unsigned long arg)
+{
+ struct cdrom_read_audio __user *cdread_audio;
+ struct compat_cdrom_read_audio __user *cdread_audio32;
+ __u32 data;
+ void __user *datap;
+
+ cdread_audio = compat_alloc_user_space(sizeof(*cdread_audio));
+ cdread_audio32 = compat_ptr(arg);
+
+ if (copy_in_user(&cdread_audio->addr,
+ &cdread_audio32->addr,
+ (sizeof(*cdread_audio32) -
+ sizeof(compat_caddr_t))))
+ return -EFAULT;
+
+ if (get_user(data, &cdread_audio32->buf))
+ return -EFAULT;
+ datap = compat_ptr(data);
+ if (put_user(datap, &cdread_audio->buf))
+ return -EFAULT;
+
+ return __blkdev_driver_ioctl(bdev, mode, cmd,
+ (unsigned long)cdread_audio);
+}
+
+static int compat_cdrom_generic_command(struct block_device *bdev, fmode_t mode,
+ unsigned int cmd, unsigned long arg)
+{
+ struct cdrom_generic_command __user *cgc;
+ struct compat_cdrom_generic_command __user *cgc32;
+ u32 data;
+ unsigned char dir;
+ int itmp;
+
+ cgc = compat_alloc_user_space(sizeof(*cgc));
+ cgc32 = compat_ptr(arg);
+
+ if (copy_in_user(&cgc->cmd, &cgc32->cmd, sizeof(cgc->cmd)) ||
+ get_user(data, &cgc32->buffer) ||
+ put_user(compat_ptr(data), &cgc->buffer) ||
+ copy_in_user(&cgc->buflen, &cgc32->buflen,
+ (sizeof(unsigned int) + sizeof(int))) ||
+ get_user(data, &cgc32->sense) ||
+ put_user(compat_ptr(data), &cgc->sense) ||
+ get_user(dir, &cgc32->data_direction) ||
+ put_user(dir, &cgc->data_direction) ||
+ get_user(itmp, &cgc32->quiet) ||
+ put_user(itmp, &cgc->quiet) ||
+ get_user(itmp, &cgc32->timeout) ||
+ put_user(itmp, &cgc->timeout) ||
+ get_user(data, &cgc32->reserved[0]) ||
+ put_user(compat_ptr(data), &cgc->reserved[0]))
+ return -EFAULT;
+
+ return __blkdev_driver_ioctl(bdev, mode, cmd, (unsigned long)cgc);
+}
+
+struct compat_blkpg_ioctl_arg {
+ compat_int_t op;
+ compat_int_t flags;
+ compat_int_t datalen;
+ compat_caddr_t data;
+};
+
+static int compat_blkpg_ioctl(struct block_device *bdev, fmode_t mode,
+ unsigned int cmd, struct compat_blkpg_ioctl_arg __user *ua32)
+{
+ struct blkpg_ioctl_arg __user *a = compat_alloc_user_space(sizeof(*a));
+ compat_caddr_t udata;
+ compat_int_t n;
+ int err;
+
+ err = get_user(n, &ua32->op);
+ err |= put_user(n, &a->op);
+ err |= get_user(n, &ua32->flags);
+ err |= put_user(n, &a->flags);
+ err |= get_user(n, &ua32->datalen);
+ err |= put_user(n, &a->datalen);
+ err |= get_user(udata, &ua32->data);
+ err |= put_user(compat_ptr(udata), &a->data);
+ if (err)
+ return err;
+
+ return blkdev_ioctl(bdev, mode, cmd, (unsigned long)a);
+}
+
+#define BLKBSZGET_32 _IOR(0x12, 112, int)
+#define BLKBSZSET_32 _IOW(0x12, 113, int)
+#define BLKGETSIZE64_32 _IOR(0x12, 114, int)
+
+static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
+ unsigned cmd, unsigned long arg)
+{
+ switch (cmd) {
+ case HDIO_GET_UNMASKINTR:
+ case HDIO_GET_MULTCOUNT:
+ case HDIO_GET_KEEPSETTINGS:
+ case HDIO_GET_32BIT:
+ case HDIO_GET_NOWERR:
+ case HDIO_GET_DMA:
+ case HDIO_GET_NICE:
+ case HDIO_GET_WCACHE:
+ case HDIO_GET_ACOUSTIC:
+ case HDIO_GET_ADDRESS:
+ case HDIO_GET_BUSSTATE:
+ return compat_hdio_ioctl(bdev, mode, cmd, arg);
+ case CDROMREADAUDIO:
+ return compat_cdrom_read_audio(bdev, mode, cmd, arg);
+ case CDROM_SEND_PACKET:
+ return compat_cdrom_generic_command(bdev, mode, cmd, arg);
+
+ /*
+ * No handler required for the ones below, we just need to
+ * convert arg to a 64 bit pointer.
+ */
+ case BLKSECTSET:
+ /*
+ * 0x03 -- HD/IDE ioctl's used by hdparm and friends.
+ * Some need translations, these do not.
+ */
+ case HDIO_GET_IDENTITY:
+ case HDIO_DRIVE_TASK:
+ case HDIO_DRIVE_CMD:
+ /* 0x330 is reserved -- it used to be HDIO_GETGEO_BIG */
+ case 0x330:
+ /* CDROM stuff */
+ case CDROMPAUSE:
+ case CDROMRESUME:
+ case CDROMPLAYMSF:
+ case CDROMPLAYTRKIND:
+ case CDROMREADTOCHDR:
+ case CDROMREADTOCENTRY:
+ case CDROMSTOP:
+ case CDROMSTART:
+ case CDROMEJECT:
+ case CDROMVOLCTRL:
+ case CDROMSUBCHNL:
+ case CDROMMULTISESSION:
+ case CDROM_GET_MCN:
+ case CDROMRESET:
+ case CDROMVOLREAD:
+ case CDROMSEEK:
+ case CDROMPLAYBLK:
+ case CDROMCLOSETRAY:
+ case CDROM_DISC_STATUS:
+ case CDROM_CHANGER_NSLOTS:
+ case CDROM_GET_CAPABILITY:
+ /* Ignore cdrom.h about these next 5 ioctls, they absolutely do
+ * not take a struct cdrom_read, instead they take a struct cdrom_msf
+ * which is compatible.
+ */
+ case CDROMREADMODE2:
+ case CDROMREADMODE1:
+ case CDROMREADRAW:
+ case CDROMREADCOOKED:
+ case CDROMREADALL:
+ /* DVD ioctls */
+ case DVD_READ_STRUCT:
+ case DVD_WRITE_STRUCT:
+ case DVD_AUTH:
+ arg = (unsigned long)compat_ptr(arg);
+ /* These intepret arg as an unsigned long, not as a pointer,
+ * so we must not do compat_ptr() conversion. */
+ case HDIO_SET_MULTCOUNT:
+ case HDIO_SET_UNMASKINTR:
+ case HDIO_SET_KEEPSETTINGS:
+ case HDIO_SET_32BIT:
+ case HDIO_SET_NOWERR:
+ case HDIO_SET_DMA:
+ case HDIO_SET_PIO_MODE:
+ case HDIO_SET_NICE:
+ case HDIO_SET_WCACHE:
+ case HDIO_SET_ACOUSTIC:
+ case HDIO_SET_BUSSTATE:
+ case HDIO_SET_ADDRESS:
+ case CDROMEJECT_SW:
+ case CDROM_SET_OPTIONS:
+ case CDROM_CLEAR_OPTIONS:
+ case CDROM_SELECT_SPEED:
+ case CDROM_SELECT_DISC:
+ case CDROM_MEDIA_CHANGED:
+ case CDROM_DRIVE_STATUS:
+ case CDROM_LOCKDOOR:
+ case CDROM_DEBUG:
+ break;
+ default:
+ /* unknown ioctl number */
+ return -ENOIOCTLCMD;
+ }
+
+ return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+}
+
+/* Most of the generic ioctls are handled in the normal fallback path.
+ This assumes the blkdev's low level compat_ioctl always returns
+ ENOIOCTLCMD for unknown ioctls. */
+long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+ int ret = -ENOIOCTLCMD;
+ struct inode *inode = file->f_mapping->host;
+ struct block_device *bdev = inode->i_bdev;
+ struct gendisk *disk = bdev->bd_disk;
+ fmode_t mode = file->f_mode;
+ loff_t size;
+ unsigned int max_sectors;
+
+ /*
+ * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
+ * to updated it before every ioctl.
+ */
+ if (file->f_flags & O_NDELAY)
+ mode |= FMODE_NDELAY;
+ else
+ mode &= ~FMODE_NDELAY;
+
+ switch (cmd) {
+ case HDIO_GETGEO:
+ return compat_hdio_getgeo(disk, bdev, compat_ptr(arg));
+ case BLKPBSZGET:
+ return compat_put_uint(arg, bdev_physical_block_size(bdev));
+ case BLKIOMIN:
+ return compat_put_uint(arg, bdev_io_min(bdev));
+ case BLKIOOPT:
+ return compat_put_uint(arg, bdev_io_opt(bdev));
+ case BLKALIGNOFF:
+ return compat_put_int(arg, bdev_alignment_offset(bdev));
+ case BLKDISCARDZEROES:
+ return compat_put_uint(arg, 0);
+ case BLKFLSBUF:
+ case BLKROSET:
+ case BLKDISCARD:
+ case BLKSECDISCARD:
+ case BLKZEROOUT:
+ /*
+ * the ones below are implemented in blkdev_locked_ioctl,
+ * but we call blkdev_ioctl, which gets the lock for us
+ */
+ case BLKRRPART:
+ case BLKREPORTZONE:
+ case BLKRESETZONE:
+ return blkdev_ioctl(bdev, mode, cmd,
+ (unsigned long)compat_ptr(arg));
+ case BLKBSZSET_32:
+ return blkdev_ioctl(bdev, mode, BLKBSZSET,
+ (unsigned long)compat_ptr(arg));
+ case BLKPG:
+ return compat_blkpg_ioctl(bdev, mode, cmd, compat_ptr(arg));
+ case BLKRAGET:
+ case BLKFRAGET:
+ if (!arg)
+ return -EINVAL;
+ return compat_put_long(arg,
+ (bdev->bd_bdi->ra_pages * PAGE_SIZE) / 512);
+ case BLKROGET: /* compatible */
+ return compat_put_int(arg, bdev_read_only(bdev) != 0);
+ case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
+ return compat_put_int(arg, block_size(bdev));
+ case BLKSSZGET: /* get block device hardware sector size */
+ return compat_put_int(arg, bdev_logical_block_size(bdev));
+ case BLKSECTGET:
+ max_sectors = min_t(unsigned int, USHRT_MAX,
+ queue_max_sectors(bdev_get_queue(bdev)));
+ return compat_put_ushort(arg, max_sectors);
+ case BLKROTATIONAL:
+ return compat_put_ushort(arg,
+ !blk_queue_nonrot(bdev_get_queue(bdev)));
+ case BLKRASET: /* compatible, but no compat_ptr (!) */
+ case BLKFRASET:
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
+ return 0;
+ case BLKGETSIZE:
+ size = i_size_read(bdev->bd_inode);
+ if ((size >> 9) > ~0UL)
+ return -EFBIG;
+ return compat_put_ulong(arg, size >> 9);
+
+ case BLKGETSIZE64_32:
+ return compat_put_u64(arg, i_size_read(bdev->bd_inode));
+
+ case BLKTRACESETUP32:
+ case BLKTRACESTART: /* compatible */
+ case BLKTRACESTOP: /* compatible */
+ case BLKTRACETEARDOWN: /* compatible */
+ ret = blk_trace_ioctl(bdev, cmd, compat_ptr(arg));
+ return ret;
+ case IOC_PR_REGISTER:
+ case IOC_PR_RESERVE:
+ case IOC_PR_RELEASE:
+ case IOC_PR_PREEMPT:
+ case IOC_PR_PREEMPT_ABORT:
+ case IOC_PR_CLEAR:
+ return blkdev_ioctl(bdev, mode, cmd,
+ (unsigned long)compat_ptr(arg));
+ default:
+ if (disk->fops->compat_ioctl)
+ ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
+ if (ret == -ENOIOCTLCMD)
+ ret = compat_blkdev_driver_ioctl(bdev, mode, cmd, arg);
+ return ret;
+ }
+}
diff --git a/src/kernel/linux/v4.14/block/deadline-iosched.c b/src/kernel/linux/v4.14/block/deadline-iosched.c
new file mode 100644
index 0000000..b83f774
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/deadline-iosched.c
@@ -0,0 +1,469 @@
+/*
+ * Deadline i/o scheduler.
+ *
+ * Copyright (C) 2002 Jens Axboe <axboe@kernel.dk>
+ */
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/elevator.h>
+#include <linux/bio.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/compiler.h>
+#include <linux/rbtree.h>
+
+/*
+ * See Documentation/block/deadline-iosched.txt
+ */
+static const int read_expire = HZ / 2; /* max time before a read is submitted. */
+static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
+static const int writes_starved = 2; /* max times reads can starve a write */
+static const int fifo_batch = 16; /* # of sequential requests treated as one
+ by the above parameters. For throughput. */
+
+struct deadline_data {
+ /*
+ * run time data
+ */
+
+ /*
+ * requests (deadline_rq s) are present on both sort_list and fifo_list
+ */
+ struct rb_root sort_list[2];
+ struct list_head fifo_list[2];
+
+ /*
+ * next in sort order. read, write or both are NULL
+ */
+ struct request *next_rq[2];
+ unsigned int batching; /* number of sequential requests made */
+ unsigned int starved; /* times reads have starved writes */
+
+ /*
+ * settings that change how the i/o scheduler behaves
+ */
+ int fifo_expire[2];
+ int fifo_batch;
+ int writes_starved;
+ int front_merges;
+};
+
+static void deadline_move_request(struct deadline_data *, struct request *);
+
+static inline struct rb_root *
+deadline_rb_root(struct deadline_data *dd, struct request *rq)
+{
+ return &dd->sort_list[rq_data_dir(rq)];
+}
+
+/*
+ * get the request after `rq' in sector-sorted order
+ */
+static inline struct request *
+deadline_latter_request(struct request *rq)
+{
+ struct rb_node *node = rb_next(&rq->rb_node);
+
+ if (node)
+ return rb_entry_rq(node);
+
+ return NULL;
+}
+
+static void
+deadline_add_rq_rb(struct deadline_data *dd, struct request *rq)
+{
+ struct rb_root *root = deadline_rb_root(dd, rq);
+
+ elv_rb_add(root, rq);
+}
+
+static inline void
+deadline_del_rq_rb(struct deadline_data *dd, struct request *rq)
+{
+ const int data_dir = rq_data_dir(rq);
+
+ if (dd->next_rq[data_dir] == rq)
+ dd->next_rq[data_dir] = deadline_latter_request(rq);
+
+ elv_rb_del(deadline_rb_root(dd, rq), rq);
+}
+
+/*
+ * add rq to rbtree and fifo
+ */
+static void
+deadline_add_request(struct request_queue *q, struct request *rq)
+{
+ struct deadline_data *dd = q->elevator->elevator_data;
+ const int data_dir = rq_data_dir(rq);
+
+ deadline_add_rq_rb(dd, rq);
+
+ /*
+ * set expire time and add to fifo list
+ */
+ rq->fifo_time = jiffies + dd->fifo_expire[data_dir];
+ list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]);
+}
+
+/*
+ * remove rq from rbtree and fifo.
+ */
+static void deadline_remove_request(struct request_queue *q, struct request *rq)
+{
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ rq_fifo_clear(rq);
+ deadline_del_rq_rb(dd, rq);
+}
+
+static enum elv_merge
+deadline_merge(struct request_queue *q, struct request **req, struct bio *bio)
+{
+ struct deadline_data *dd = q->elevator->elevator_data;
+ struct request *__rq;
+
+ /*
+ * check for front merge
+ */
+ if (dd->front_merges) {
+ sector_t sector = bio_end_sector(bio);
+
+ __rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
+ if (__rq) {
+ BUG_ON(sector != blk_rq_pos(__rq));
+
+ if (elv_bio_merge_ok(__rq, bio)) {
+ *req = __rq;
+ return ELEVATOR_FRONT_MERGE;
+ }
+ }
+ }
+
+ return ELEVATOR_NO_MERGE;
+}
+
+static void deadline_merged_request(struct request_queue *q,
+ struct request *req, enum elv_merge type)
+{
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ /*
+ * if the merge was a front merge, we need to reposition request
+ */
+ if (type == ELEVATOR_FRONT_MERGE) {
+ elv_rb_del(deadline_rb_root(dd, req), req);
+ deadline_add_rq_rb(dd, req);
+ }
+}
+
+static void
+deadline_merged_requests(struct request_queue *q, struct request *req,
+ struct request *next)
+{
+ /*
+ * if next expires before rq, assign its expire time to rq
+ * and move into next position (next will be deleted) in fifo
+ */
+ if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
+ if (time_before((unsigned long)next->fifo_time,
+ (unsigned long)req->fifo_time)) {
+ list_move(&req->queuelist, &next->queuelist);
+ req->fifo_time = next->fifo_time;
+ }
+ }
+
+ /*
+ * kill knowledge of next, this one is a goner
+ */
+ deadline_remove_request(q, next);
+}
+
+/*
+ * move request from sort list to dispatch queue.
+ */
+static inline void
+deadline_move_to_dispatch(struct deadline_data *dd, struct request *rq)
+{
+ struct request_queue *q = rq->q;
+
+ deadline_remove_request(q, rq);
+ elv_dispatch_add_tail(q, rq);
+}
+
+/*
+ * move an entry to dispatch queue
+ */
+static void
+deadline_move_request(struct deadline_data *dd, struct request *rq)
+{
+ const int data_dir = rq_data_dir(rq);
+
+ dd->next_rq[READ] = NULL;
+ dd->next_rq[WRITE] = NULL;
+ dd->next_rq[data_dir] = deadline_latter_request(rq);
+
+ /*
+ * take it off the sort and fifo list, move
+ * to dispatch queue
+ */
+ deadline_move_to_dispatch(dd, rq);
+}
+
+/*
+ * deadline_check_fifo returns 0 if there are no expired requests on the fifo,
+ * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir])
+ */
+static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
+{
+ struct request *rq = rq_entry_fifo(dd->fifo_list[ddir].next);
+
+ /*
+ * rq is expired!
+ */
+ if (time_after_eq(jiffies, (unsigned long)rq->fifo_time))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * deadline_dispatch_requests selects the best request according to
+ * read/write expire, fifo_batch, etc
+ */
+static int deadline_dispatch_requests(struct request_queue *q, int force)
+{
+ struct deadline_data *dd = q->elevator->elevator_data;
+ const int reads = !list_empty(&dd->fifo_list[READ]);
+ const int writes = !list_empty(&dd->fifo_list[WRITE]);
+ struct request *rq;
+ int data_dir;
+
+ /*
+ * batches are currently reads XOR writes
+ */
+ if (dd->next_rq[WRITE])
+ rq = dd->next_rq[WRITE];
+ else
+ rq = dd->next_rq[READ];
+
+ if (rq && dd->batching < dd->fifo_batch)
+ /* we have a next request are still entitled to batch */
+ goto dispatch_request;
+
+ /*
+ * at this point we are not running a batch. select the appropriate
+ * data direction (read / write)
+ */
+
+ if (reads) {
+ BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[READ]));
+
+ if (writes && (dd->starved++ >= dd->writes_starved))
+ goto dispatch_writes;
+
+ data_dir = READ;
+
+ goto dispatch_find_request;
+ }
+
+ /*
+ * there are either no reads or writes have been starved
+ */
+
+ if (writes) {
+dispatch_writes:
+ BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[WRITE]));
+
+ dd->starved = 0;
+
+ data_dir = WRITE;
+
+ goto dispatch_find_request;
+ }
+
+ return 0;
+
+dispatch_find_request:
+ /*
+ * we are not running a batch, find best request for selected data_dir
+ */
+ if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) {
+ /*
+ * A deadline has expired, the last request was in the other
+ * direction, or we have run out of higher-sectored requests.
+ * Start again from the request with the earliest expiry time.
+ */
+ rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
+ } else {
+ /*
+ * The last req was the same dir and we have a next request in
+ * sort order. No expired requests so continue on from here.
+ */
+ rq = dd->next_rq[data_dir];
+ }
+
+ dd->batching = 0;
+
+dispatch_request:
+ /*
+ * rq is the selected appropriate request.
+ */
+ dd->batching++;
+ deadline_move_request(dd, rq);
+
+ return 1;
+}
+
+static void deadline_exit_queue(struct elevator_queue *e)
+{
+ struct deadline_data *dd = e->elevator_data;
+
+ BUG_ON(!list_empty(&dd->fifo_list[READ]));
+ BUG_ON(!list_empty(&dd->fifo_list[WRITE]));
+
+ kfree(dd);
+}
+
+/*
+ * initialize elevator private data (deadline_data).
+ */
+static int deadline_init_queue(struct request_queue *q, struct elevator_type *e)
+{
+ struct deadline_data *dd;
+ struct elevator_queue *eq;
+
+ eq = elevator_alloc(q, e);
+ if (!eq)
+ return -ENOMEM;
+
+ dd = kzalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
+ if (!dd) {
+ kobject_put(&eq->kobj);
+ return -ENOMEM;
+ }
+ eq->elevator_data = dd;
+
+ INIT_LIST_HEAD(&dd->fifo_list[READ]);
+ INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
+ dd->sort_list[READ] = RB_ROOT;
+ dd->sort_list[WRITE] = RB_ROOT;
+ dd->fifo_expire[READ] = read_expire;
+ dd->fifo_expire[WRITE] = write_expire;
+ dd->writes_starved = writes_starved;
+ dd->front_merges = 1;
+ dd->fifo_batch = fifo_batch;
+
+ spin_lock_irq(q->queue_lock);
+ q->elevator = eq;
+ spin_unlock_irq(q->queue_lock);
+ return 0;
+}
+
+/*
+ * sysfs parts below
+ */
+
+static ssize_t
+deadline_var_show(int var, char *page)
+{
+ return sprintf(page, "%d\n", var);
+}
+
+static void
+deadline_var_store(int *var, const char *page)
+{
+ char *p = (char *) page;
+
+ *var = simple_strtol(p, &p, 10);
+}
+
+#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
+static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+{ \
+ struct deadline_data *dd = e->elevator_data; \
+ int __data = __VAR; \
+ if (__CONV) \
+ __data = jiffies_to_msecs(__data); \
+ return deadline_var_show(__data, (page)); \
+}
+SHOW_FUNCTION(deadline_read_expire_show, dd->fifo_expire[READ], 1);
+SHOW_FUNCTION(deadline_write_expire_show, dd->fifo_expire[WRITE], 1);
+SHOW_FUNCTION(deadline_writes_starved_show, dd->writes_starved, 0);
+SHOW_FUNCTION(deadline_front_merges_show, dd->front_merges, 0);
+SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0);
+#undef SHOW_FUNCTION
+
+#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
+{ \
+ struct deadline_data *dd = e->elevator_data; \
+ int __data; \
+ deadline_var_store(&__data, (page)); \
+ if (__data < (MIN)) \
+ __data = (MIN); \
+ else if (__data > (MAX)) \
+ __data = (MAX); \
+ if (__CONV) \
+ *(__PTR) = msecs_to_jiffies(__data); \
+ else \
+ *(__PTR) = __data; \
+ return count; \
+}
+STORE_FUNCTION(deadline_read_expire_store, &dd->fifo_expire[READ], 0, INT_MAX, 1);
+STORE_FUNCTION(deadline_write_expire_store, &dd->fifo_expire[WRITE], 0, INT_MAX, 1);
+STORE_FUNCTION(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX, 0);
+STORE_FUNCTION(deadline_front_merges_store, &dd->front_merges, 0, 1, 0);
+STORE_FUNCTION(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX, 0);
+#undef STORE_FUNCTION
+
+#define DD_ATTR(name) \
+ __ATTR(name, S_IRUGO|S_IWUSR, deadline_##name##_show, \
+ deadline_##name##_store)
+
+static struct elv_fs_entry deadline_attrs[] = {
+ DD_ATTR(read_expire),
+ DD_ATTR(write_expire),
+ DD_ATTR(writes_starved),
+ DD_ATTR(front_merges),
+ DD_ATTR(fifo_batch),
+ __ATTR_NULL
+};
+
+static struct elevator_type iosched_deadline = {
+ .ops.sq = {
+ .elevator_merge_fn = deadline_merge,
+ .elevator_merged_fn = deadline_merged_request,
+ .elevator_merge_req_fn = deadline_merged_requests,
+ .elevator_dispatch_fn = deadline_dispatch_requests,
+ .elevator_add_req_fn = deadline_add_request,
+ .elevator_former_req_fn = elv_rb_former_request,
+ .elevator_latter_req_fn = elv_rb_latter_request,
+ .elevator_init_fn = deadline_init_queue,
+ .elevator_exit_fn = deadline_exit_queue,
+ },
+
+ .elevator_attrs = deadline_attrs,
+ .elevator_name = "deadline",
+ .elevator_owner = THIS_MODULE,
+};
+
+static int __init deadline_init(void)
+{
+ return elv_register(&iosched_deadline);
+}
+
+static void __exit deadline_exit(void)
+{
+ elv_unregister(&iosched_deadline);
+}
+
+module_init(deadline_init);
+module_exit(deadline_exit);
+
+MODULE_AUTHOR("Jens Axboe");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("deadline IO scheduler");
diff --git a/src/kernel/linux/v4.14/block/elevator.c b/src/kernel/linux/v4.14/block/elevator.c
new file mode 100644
index 0000000..8320d97
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/elevator.c
@@ -0,0 +1,1169 @@
+/*
+ * Block device elevator/IO-scheduler.
+ *
+ * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
+ *
+ * 30042000 Jens Axboe <axboe@kernel.dk> :
+ *
+ * Split the elevator a bit so that it is possible to choose a different
+ * one or even write a new "plug in". There are three pieces:
+ * - elevator_fn, inserts a new request in the queue list
+ * - elevator_merge_fn, decides whether a new buffer can be merged with
+ * an existing request
+ * - elevator_dequeue_fn, called when a request is taken off the active list
+ *
+ * 20082000 Dave Jones <davej@suse.de> :
+ * Removed tests for max-bomb-segments, which was breaking elvtune
+ * when run without -bN
+ *
+ * Jens:
+ * - Rework again to work with bio instead of buffer_heads
+ * - loose bi_dev comparisons, partition handling is right now
+ * - completely modularize elevator setup and teardown
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/elevator.h>
+#include <linux/bio.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/compiler.h>
+#include <linux/blktrace_api.h>
+#include <linux/hash.h>
+#include <linux/uaccess.h>
+#include <linux/pm_runtime.h>
+#include <linux/blk-cgroup.h>
+
+#include <trace/events/block.h>
+
+#include "blk.h"
+#include "blk-mq-sched.h"
+#include "blk-wbt.h"
+
+static DEFINE_SPINLOCK(elv_list_lock);
+static LIST_HEAD(elv_list);
+
+/*
+ * Merge hash stuff.
+ */
+#define rq_hash_key(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq))
+
+/*
+ * Query io scheduler to see if the current process issuing bio may be
+ * merged with rq.
+ */
+static int elv_iosched_allow_bio_merge(struct request *rq, struct bio *bio)
+{
+ struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+
+ if (e->uses_mq && e->type->ops.mq.allow_merge)
+ return e->type->ops.mq.allow_merge(q, rq, bio);
+ else if (!e->uses_mq && e->type->ops.sq.elevator_allow_bio_merge_fn)
+ return e->type->ops.sq.elevator_allow_bio_merge_fn(q, rq, bio);
+
+ return 1;
+}
+
+/*
+ * can we safely merge with this request?
+ */
+bool elv_bio_merge_ok(struct request *rq, struct bio *bio)
+{
+ if (!blk_rq_merge_ok(rq, bio))
+ return false;
+
+ if (!elv_iosched_allow_bio_merge(rq, bio))
+ return false;
+
+ return true;
+}
+EXPORT_SYMBOL(elv_bio_merge_ok);
+
+/*
+ * Return scheduler with name 'name' and with matching 'mq capability
+ */
+static struct elevator_type *elevator_find(const char *name, bool mq)
+{
+ struct elevator_type *e;
+
+ list_for_each_entry(e, &elv_list, list) {
+ if (!strcmp(e->elevator_name, name) && (mq == e->uses_mq))
+ return e;
+ }
+
+ return NULL;
+}
+
+static void elevator_put(struct elevator_type *e)
+{
+ module_put(e->elevator_owner);
+}
+
+static struct elevator_type *elevator_get(struct request_queue *q,
+ const char *name, bool try_loading)
+{
+ struct elevator_type *e;
+
+ spin_lock(&elv_list_lock);
+
+ e = elevator_find(name, q->mq_ops != NULL);
+ if (!e && try_loading) {
+ spin_unlock(&elv_list_lock);
+ request_module("%s-iosched", name);
+ spin_lock(&elv_list_lock);
+ e = elevator_find(name, q->mq_ops != NULL);
+ }
+
+ if (e && !try_module_get(e->elevator_owner))
+ e = NULL;
+
+ spin_unlock(&elv_list_lock);
+ return e;
+}
+
+static char chosen_elevator[ELV_NAME_MAX];
+
+static int __init elevator_setup(char *str)
+{
+ /*
+ * Be backwards-compatible with previous kernels, so users
+ * won't get the wrong elevator.
+ */
+ strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1);
+ return 1;
+}
+
+__setup("elevator=", elevator_setup);
+
+/* called during boot to load the elevator chosen by the elevator param */
+void __init load_default_elevator_module(void)
+{
+ struct elevator_type *e;
+
+ if (!chosen_elevator[0])
+ return;
+
+ /*
+ * Boot parameter is deprecated, we haven't supported that for MQ.
+ * Only look for non-mq schedulers from here.
+ */
+ spin_lock(&elv_list_lock);
+ e = elevator_find(chosen_elevator, false);
+ spin_unlock(&elv_list_lock);
+
+ if (!e)
+ request_module("%s-iosched", chosen_elevator);
+}
+
+static struct kobj_type elv_ktype;
+
+struct elevator_queue *elevator_alloc(struct request_queue *q,
+ struct elevator_type *e)
+{
+ struct elevator_queue *eq;
+
+ eq = kzalloc_node(sizeof(*eq), GFP_KERNEL, q->node);
+ if (unlikely(!eq))
+ return NULL;
+
+ eq->type = e;
+ kobject_init(&eq->kobj, &elv_ktype);
+ mutex_init(&eq->sysfs_lock);
+ hash_init(eq->hash);
+ eq->uses_mq = e->uses_mq;
+
+ return eq;
+}
+EXPORT_SYMBOL(elevator_alloc);
+
+static void elevator_release(struct kobject *kobj)
+{
+ struct elevator_queue *e;
+
+ e = container_of(kobj, struct elevator_queue, kobj);
+ elevator_put(e->type);
+ kfree(e);
+}
+
+int elevator_init(struct request_queue *q, char *name)
+{
+ struct elevator_type *e = NULL;
+ int err;
+
+ /*
+ * q->sysfs_lock must be held to provide mutual exclusion between
+ * elevator_switch() and here.
+ */
+ lockdep_assert_held(&q->sysfs_lock);
+
+ if (unlikely(q->elevator))
+ return 0;
+
+ INIT_LIST_HEAD(&q->queue_head);
+ q->last_merge = NULL;
+ q->end_sector = 0;
+ q->boundary_rq = NULL;
+
+ if (name) {
+ e = elevator_get(q, name, true);
+ if (!e)
+ return -EINVAL;
+ }
+
+ /*
+ * Use the default elevator specified by config boot param for
+ * non-mq devices, or by config option. Don't try to load modules
+ * as we could be running off async and request_module() isn't
+ * allowed from async.
+ */
+ if (!e && !q->mq_ops && *chosen_elevator) {
+ e = elevator_get(q, chosen_elevator, false);
+ if (!e)
+ printk(KERN_ERR "I/O scheduler %s not found\n",
+ chosen_elevator);
+ }
+
+ if (!e) {
+ /*
+ * For blk-mq devices, we default to using mq-deadline,
+ * if available, for single queue devices. If deadline
+ * isn't available OR we have multiple queues, default
+ * to "none".
+ */
+ if (q->mq_ops) {
+ if (q->nr_hw_queues == 1)
+ e = elevator_get(q, "mq-deadline", false);
+ if (!e)
+ return 0;
+ } else
+ e = elevator_get(q, CONFIG_DEFAULT_IOSCHED, false);
+
+ if (!e) {
+ printk(KERN_ERR
+ "Default I/O scheduler not found. " \
+ "Using noop.\n");
+ e = elevator_get(q, "noop", false);
+ }
+ }
+
+ if (e->uses_mq)
+ err = blk_mq_init_sched(q, e);
+ else
+ err = e->ops.sq.elevator_init_fn(q, e);
+ if (err)
+ elevator_put(e);
+ return err;
+}
+EXPORT_SYMBOL(elevator_init);
+
+void elevator_exit(struct request_queue *q, struct elevator_queue *e)
+{
+ mutex_lock(&e->sysfs_lock);
+ if (e->uses_mq && e->type->ops.mq.exit_sched)
+ blk_mq_exit_sched(q, e);
+ else if (!e->uses_mq && e->type->ops.sq.elevator_exit_fn)
+ e->type->ops.sq.elevator_exit_fn(e);
+ mutex_unlock(&e->sysfs_lock);
+
+ kobject_put(&e->kobj);
+}
+EXPORT_SYMBOL(elevator_exit);
+
+static inline void __elv_rqhash_del(struct request *rq)
+{
+ hash_del(&rq->hash);
+ rq->rq_flags &= ~RQF_HASHED;
+}
+
+void elv_rqhash_del(struct request_queue *q, struct request *rq)
+{
+ if (ELV_ON_HASH(rq))
+ __elv_rqhash_del(rq);
+}
+EXPORT_SYMBOL_GPL(elv_rqhash_del);
+
+void elv_rqhash_add(struct request_queue *q, struct request *rq)
+{
+ struct elevator_queue *e = q->elevator;
+
+ BUG_ON(ELV_ON_HASH(rq));
+ hash_add(e->hash, &rq->hash, rq_hash_key(rq));
+ rq->rq_flags |= RQF_HASHED;
+}
+EXPORT_SYMBOL_GPL(elv_rqhash_add);
+
+void elv_rqhash_reposition(struct request_queue *q, struct request *rq)
+{
+ __elv_rqhash_del(rq);
+ elv_rqhash_add(q, rq);
+}
+
+struct request *elv_rqhash_find(struct request_queue *q, sector_t offset)
+{
+ struct elevator_queue *e = q->elevator;
+ struct hlist_node *next;
+ struct request *rq;
+
+ hash_for_each_possible_safe(e->hash, rq, next, hash, offset) {
+ BUG_ON(!ELV_ON_HASH(rq));
+
+ if (unlikely(!rq_mergeable(rq))) {
+ __elv_rqhash_del(rq);
+ continue;
+ }
+
+ if (rq_hash_key(rq) == offset)
+ return rq;
+ }
+
+ return NULL;
+}
+
+/*
+ * RB-tree support functions for inserting/lookup/removal of requests
+ * in a sorted RB tree.
+ */
+void elv_rb_add(struct rb_root *root, struct request *rq)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct request *__rq;
+
+ while (*p) {
+ parent = *p;
+ __rq = rb_entry(parent, struct request, rb_node);
+
+ if (blk_rq_pos(rq) < blk_rq_pos(__rq))
+ p = &(*p)->rb_left;
+ else if (blk_rq_pos(rq) >= blk_rq_pos(__rq))
+ p = &(*p)->rb_right;
+ }
+
+ rb_link_node(&rq->rb_node, parent, p);
+ rb_insert_color(&rq->rb_node, root);
+}
+EXPORT_SYMBOL(elv_rb_add);
+
+void elv_rb_del(struct rb_root *root, struct request *rq)
+{
+ BUG_ON(RB_EMPTY_NODE(&rq->rb_node));
+ rb_erase(&rq->rb_node, root);
+ RB_CLEAR_NODE(&rq->rb_node);
+}
+EXPORT_SYMBOL(elv_rb_del);
+
+struct request *elv_rb_find(struct rb_root *root, sector_t sector)
+{
+ struct rb_node *n = root->rb_node;
+ struct request *rq;
+
+ while (n) {
+ rq = rb_entry(n, struct request, rb_node);
+
+ if (sector < blk_rq_pos(rq))
+ n = n->rb_left;
+ else if (sector > blk_rq_pos(rq))
+ n = n->rb_right;
+ else
+ return rq;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL(elv_rb_find);
+
+/*
+ * Insert rq into dispatch queue of q. Queue lock must be held on
+ * entry. rq is sort instead into the dispatch queue. To be used by
+ * specific elevators.
+ */
+void elv_dispatch_sort(struct request_queue *q, struct request *rq)
+{
+ sector_t boundary;
+ struct list_head *entry;
+
+ if (q->last_merge == rq)
+ q->last_merge = NULL;
+
+ elv_rqhash_del(q, rq);
+
+ q->nr_sorted--;
+
+ boundary = q->end_sector;
+ list_for_each_prev(entry, &q->queue_head) {
+ struct request *pos = list_entry_rq(entry);
+
+ if (req_op(rq) != req_op(pos))
+ break;
+ if (rq_data_dir(rq) != rq_data_dir(pos))
+ break;
+ if (pos->rq_flags & (RQF_STARTED | RQF_SOFTBARRIER))
+ break;
+ if (blk_rq_pos(rq) >= boundary) {
+ if (blk_rq_pos(pos) < boundary)
+ continue;
+ } else {
+ if (blk_rq_pos(pos) >= boundary)
+ break;
+ }
+ if (blk_rq_pos(rq) >= blk_rq_pos(pos))
+ break;
+ }
+
+ list_add(&rq->queuelist, entry);
+}
+EXPORT_SYMBOL(elv_dispatch_sort);
+
+/*
+ * Insert rq into dispatch queue of q. Queue lock must be held on
+ * entry. rq is added to the back of the dispatch queue. To be used by
+ * specific elevators.
+ */
+void elv_dispatch_add_tail(struct request_queue *q, struct request *rq)
+{
+ if (q->last_merge == rq)
+ q->last_merge = NULL;
+
+ elv_rqhash_del(q, rq);
+
+ q->nr_sorted--;
+
+ q->end_sector = rq_end_sector(rq);
+ q->boundary_rq = rq;
+ list_add_tail(&rq->queuelist, &q->queue_head);
+}
+EXPORT_SYMBOL(elv_dispatch_add_tail);
+
+enum elv_merge elv_merge(struct request_queue *q, struct request **req,
+ struct bio *bio)
+{
+ struct elevator_queue *e = q->elevator;
+ struct request *__rq;
+
+ /*
+ * Levels of merges:
+ * nomerges: No merges at all attempted
+ * noxmerges: Only simple one-hit cache try
+ * merges: All merge tries attempted
+ */
+ if (blk_queue_nomerges(q) || !bio_mergeable(bio))
+ return ELEVATOR_NO_MERGE;
+
+ /*
+ * First try one-hit cache.
+ */
+ if (q->last_merge && elv_bio_merge_ok(q->last_merge, bio)) {
+ enum elv_merge ret = blk_try_merge(q->last_merge, bio);
+
+ if (ret != ELEVATOR_NO_MERGE) {
+ *req = q->last_merge;
+ return ret;
+ }
+ }
+
+ if (blk_queue_noxmerges(q))
+ return ELEVATOR_NO_MERGE;
+
+ /*
+ * See if our hash lookup can find a potential backmerge.
+ */
+ __rq = elv_rqhash_find(q, bio->bi_iter.bi_sector);
+ if (__rq && elv_bio_merge_ok(__rq, bio)) {
+ *req = __rq;
+ return ELEVATOR_BACK_MERGE;
+ }
+
+ if (e->uses_mq && e->type->ops.mq.request_merge)
+ return e->type->ops.mq.request_merge(q, req, bio);
+ else if (!e->uses_mq && e->type->ops.sq.elevator_merge_fn)
+ return e->type->ops.sq.elevator_merge_fn(q, req, bio);
+
+ return ELEVATOR_NO_MERGE;
+}
+
+/*
+ * Attempt to do an insertion back merge. Only check for the case where
+ * we can append 'rq' to an existing request, so we can throw 'rq' away
+ * afterwards.
+ *
+ * Returns true if we merged, false otherwise
+ */
+bool elv_attempt_insert_merge(struct request_queue *q, struct request *rq)
+{
+ struct request *__rq;
+ bool ret;
+
+ if (blk_queue_nomerges(q))
+ return false;
+
+ /*
+ * First try one-hit cache.
+ */
+ if (q->last_merge && blk_attempt_req_merge(q, q->last_merge, rq))
+ return true;
+
+ if (blk_queue_noxmerges(q))
+ return false;
+
+ ret = false;
+ /*
+ * See if our hash lookup can find a potential backmerge.
+ */
+ while (1) {
+ __rq = elv_rqhash_find(q, blk_rq_pos(rq));
+ if (!__rq || !blk_attempt_req_merge(q, __rq, rq))
+ break;
+
+ /* The merged request could be merged with others, try again */
+ ret = true;
+ rq = __rq;
+ }
+
+ return ret;
+}
+
+void elv_merged_request(struct request_queue *q, struct request *rq,
+ enum elv_merge type)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (e->uses_mq && e->type->ops.mq.request_merged)
+ e->type->ops.mq.request_merged(q, rq, type);
+ else if (!e->uses_mq && e->type->ops.sq.elevator_merged_fn)
+ e->type->ops.sq.elevator_merged_fn(q, rq, type);
+
+ if (type == ELEVATOR_BACK_MERGE)
+ elv_rqhash_reposition(q, rq);
+
+ q->last_merge = rq;
+}
+
+void elv_merge_requests(struct request_queue *q, struct request *rq,
+ struct request *next)
+{
+ struct elevator_queue *e = q->elevator;
+ bool next_sorted = false;
+
+ if (e->uses_mq && e->type->ops.mq.requests_merged)
+ e->type->ops.mq.requests_merged(q, rq, next);
+ else if (e->type->ops.sq.elevator_merge_req_fn) {
+ next_sorted = (__force bool)(next->rq_flags & RQF_SORTED);
+ if (next_sorted)
+ e->type->ops.sq.elevator_merge_req_fn(q, rq, next);
+ }
+
+ elv_rqhash_reposition(q, rq);
+
+ if (next_sorted) {
+ elv_rqhash_del(q, next);
+ q->nr_sorted--;
+ }
+
+ q->last_merge = rq;
+}
+
+void elv_bio_merged(struct request_queue *q, struct request *rq,
+ struct bio *bio)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (WARN_ON_ONCE(e->uses_mq))
+ return;
+
+ if (e->type->ops.sq.elevator_bio_merged_fn)
+ e->type->ops.sq.elevator_bio_merged_fn(q, rq, bio);
+}
+
+#ifdef CONFIG_PM
+static void blk_pm_requeue_request(struct request *rq)
+{
+ if (rq->q->dev && !(rq->rq_flags & RQF_PM))
+ rq->q->nr_pending--;
+}
+
+static void blk_pm_add_request(struct request_queue *q, struct request *rq)
+{
+ if (q->dev && !(rq->rq_flags & RQF_PM) && q->nr_pending++ == 0 &&
+ (q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING))
+ pm_request_resume(q->dev);
+}
+#else
+static inline void blk_pm_requeue_request(struct request *rq) {}
+static inline void blk_pm_add_request(struct request_queue *q,
+ struct request *rq)
+{
+}
+#endif
+
+void elv_requeue_request(struct request_queue *q, struct request *rq)
+{
+ /*
+ * it already went through dequeue, we need to decrement the
+ * in_flight count again
+ */
+ if (blk_account_rq(rq)) {
+ q->in_flight[rq_is_sync(rq)]--;
+ if (rq->rq_flags & RQF_SORTED)
+ elv_deactivate_rq(q, rq);
+ }
+
+ rq->rq_flags &= ~RQF_STARTED;
+
+ blk_pm_requeue_request(rq);
+
+ __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE);
+}
+
+void elv_drain_elevator(struct request_queue *q)
+{
+ struct elevator_queue *e = q->elevator;
+ static int printed;
+
+ if (WARN_ON_ONCE(e->uses_mq))
+ return;
+
+ lockdep_assert_held(q->queue_lock);
+
+ while (e->type->ops.sq.elevator_dispatch_fn(q, 1))
+ ;
+ if (q->nr_sorted && printed++ < 10) {
+ printk(KERN_ERR "%s: forced dispatching is broken "
+ "(nr_sorted=%u), please report this\n",
+ q->elevator->type->elevator_name, q->nr_sorted);
+ }
+}
+
+void __elv_add_request(struct request_queue *q, struct request *rq, int where)
+{
+ trace_block_rq_insert(q, rq);
+
+ blk_pm_add_request(q, rq);
+
+ rq->q = q;
+
+ if (rq->rq_flags & RQF_SOFTBARRIER) {
+ /* barriers are scheduling boundary, update end_sector */
+ if (!blk_rq_is_passthrough(rq)) {
+ q->end_sector = rq_end_sector(rq);
+ q->boundary_rq = rq;
+ }
+ } else if (!(rq->rq_flags & RQF_ELVPRIV) &&
+ (where == ELEVATOR_INSERT_SORT ||
+ where == ELEVATOR_INSERT_SORT_MERGE))
+ where = ELEVATOR_INSERT_BACK;
+
+ switch (where) {
+ case ELEVATOR_INSERT_REQUEUE:
+ case ELEVATOR_INSERT_FRONT:
+ rq->rq_flags |= RQF_SOFTBARRIER;
+ list_add(&rq->queuelist, &q->queue_head);
+ break;
+
+ case ELEVATOR_INSERT_BACK:
+ rq->rq_flags |= RQF_SOFTBARRIER;
+ elv_drain_elevator(q);
+ list_add_tail(&rq->queuelist, &q->queue_head);
+ /*
+ * We kick the queue here for the following reasons.
+ * - The elevator might have returned NULL previously
+ * to delay requests and returned them now. As the
+ * queue wasn't empty before this request, ll_rw_blk
+ * won't run the queue on return, resulting in hang.
+ * - Usually, back inserted requests won't be merged
+ * with anything. There's no point in delaying queue
+ * processing.
+ */
+ __blk_run_queue(q);
+ break;
+
+ case ELEVATOR_INSERT_SORT_MERGE:
+ /*
+ * If we succeed in merging this request with one in the
+ * queue already, we are done - rq has now been freed,
+ * so no need to do anything further.
+ */
+ if (elv_attempt_insert_merge(q, rq))
+ break;
+ /* fall through */
+ case ELEVATOR_INSERT_SORT:
+ BUG_ON(blk_rq_is_passthrough(rq));
+ rq->rq_flags |= RQF_SORTED;
+ q->nr_sorted++;
+ if (rq_mergeable(rq)) {
+ elv_rqhash_add(q, rq);
+ if (!q->last_merge)
+ q->last_merge = rq;
+ }
+
+ /*
+ * Some ioscheds (cfq) run q->request_fn directly, so
+ * rq cannot be accessed after calling
+ * elevator_add_req_fn.
+ */
+ q->elevator->type->ops.sq.elevator_add_req_fn(q, rq);
+ break;
+
+ case ELEVATOR_INSERT_FLUSH:
+ rq->rq_flags |= RQF_SOFTBARRIER;
+ blk_insert_flush(rq);
+ break;
+ default:
+ printk(KERN_ERR "%s: bad insertion point %d\n",
+ __func__, where);
+ BUG();
+ }
+}
+EXPORT_SYMBOL(__elv_add_request);
+
+void elv_add_request(struct request_queue *q, struct request *rq, int where)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ __elv_add_request(q, rq, where);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL(elv_add_request);
+
+struct request *elv_latter_request(struct request_queue *q, struct request *rq)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (e->uses_mq && e->type->ops.mq.next_request)
+ return e->type->ops.mq.next_request(q, rq);
+ else if (!e->uses_mq && e->type->ops.sq.elevator_latter_req_fn)
+ return e->type->ops.sq.elevator_latter_req_fn(q, rq);
+
+ return NULL;
+}
+
+struct request *elv_former_request(struct request_queue *q, struct request *rq)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (e->uses_mq && e->type->ops.mq.former_request)
+ return e->type->ops.mq.former_request(q, rq);
+ if (!e->uses_mq && e->type->ops.sq.elevator_former_req_fn)
+ return e->type->ops.sq.elevator_former_req_fn(q, rq);
+ return NULL;
+}
+
+int elv_set_request(struct request_queue *q, struct request *rq,
+ struct bio *bio, gfp_t gfp_mask)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (WARN_ON_ONCE(e->uses_mq))
+ return 0;
+
+ if (e->type->ops.sq.elevator_set_req_fn)
+ return e->type->ops.sq.elevator_set_req_fn(q, rq, bio, gfp_mask);
+ return 0;
+}
+
+void elv_put_request(struct request_queue *q, struct request *rq)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (WARN_ON_ONCE(e->uses_mq))
+ return;
+
+ if (e->type->ops.sq.elevator_put_req_fn)
+ e->type->ops.sq.elevator_put_req_fn(rq);
+}
+
+int elv_may_queue(struct request_queue *q, unsigned int op)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (WARN_ON_ONCE(e->uses_mq))
+ return 0;
+
+ if (e->type->ops.sq.elevator_may_queue_fn)
+ return e->type->ops.sq.elevator_may_queue_fn(q, op);
+
+ return ELV_MQUEUE_MAY;
+}
+
+void elv_completed_request(struct request_queue *q, struct request *rq)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (WARN_ON_ONCE(e->uses_mq))
+ return;
+
+ /*
+ * request is released from the driver, io must be done
+ */
+ if (blk_account_rq(rq)) {
+ q->in_flight[rq_is_sync(rq)]--;
+ if ((rq->rq_flags & RQF_SORTED) &&
+ e->type->ops.sq.elevator_completed_req_fn)
+ e->type->ops.sq.elevator_completed_req_fn(q, rq);
+ }
+}
+
+#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
+
+static ssize_t
+elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
+{
+ struct elv_fs_entry *entry = to_elv(attr);
+ struct elevator_queue *e;
+ ssize_t error;
+
+ if (!entry->show)
+ return -EIO;
+
+ e = container_of(kobj, struct elevator_queue, kobj);
+ mutex_lock(&e->sysfs_lock);
+ error = e->type ? entry->show(e, page) : -ENOENT;
+ mutex_unlock(&e->sysfs_lock);
+ return error;
+}
+
+static ssize_t
+elv_attr_store(struct kobject *kobj, struct attribute *attr,
+ const char *page, size_t length)
+{
+ struct elv_fs_entry *entry = to_elv(attr);
+ struct elevator_queue *e;
+ ssize_t error;
+
+ if (!entry->store)
+ return -EIO;
+
+ e = container_of(kobj, struct elevator_queue, kobj);
+ mutex_lock(&e->sysfs_lock);
+ error = e->type ? entry->store(e, page, length) : -ENOENT;
+ mutex_unlock(&e->sysfs_lock);
+ return error;
+}
+
+static const struct sysfs_ops elv_sysfs_ops = {
+ .show = elv_attr_show,
+ .store = elv_attr_store,
+};
+
+static struct kobj_type elv_ktype = {
+ .sysfs_ops = &elv_sysfs_ops,
+ .release = elevator_release,
+};
+
+int elv_register_queue(struct request_queue *q)
+{
+ struct elevator_queue *e = q->elevator;
+ int error;
+
+ error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched");
+ if (!error) {
+ struct elv_fs_entry *attr = e->type->elevator_attrs;
+ if (attr) {
+ while (attr->attr.name) {
+ if (sysfs_create_file(&e->kobj, &attr->attr))
+ break;
+ attr++;
+ }
+ }
+ kobject_uevent(&e->kobj, KOBJ_ADD);
+ e->registered = 1;
+ if (!e->uses_mq && e->type->ops.sq.elevator_registered_fn)
+ e->type->ops.sq.elevator_registered_fn(q);
+ }
+ return error;
+}
+EXPORT_SYMBOL(elv_register_queue);
+
+void elv_unregister_queue(struct request_queue *q)
+{
+ if (q) {
+ struct elevator_queue *e = q->elevator;
+
+ kobject_uevent(&e->kobj, KOBJ_REMOVE);
+ kobject_del(&e->kobj);
+ e->registered = 0;
+ /* Re-enable throttling in case elevator disabled it */
+ wbt_enable_default(q);
+ }
+}
+EXPORT_SYMBOL(elv_unregister_queue);
+
+int elv_register(struct elevator_type *e)
+{
+ char *def = "";
+
+ /* create icq_cache if requested */
+ if (e->icq_size) {
+ if (WARN_ON(e->icq_size < sizeof(struct io_cq)) ||
+ WARN_ON(e->icq_align < __alignof__(struct io_cq)))
+ return -EINVAL;
+
+ snprintf(e->icq_cache_name, sizeof(e->icq_cache_name),
+ "%s_io_cq", e->elevator_name);
+ e->icq_cache = kmem_cache_create(e->icq_cache_name, e->icq_size,
+ e->icq_align, 0, NULL);
+ if (!e->icq_cache)
+ return -ENOMEM;
+ }
+
+ /* register, don't allow duplicate names */
+ spin_lock(&elv_list_lock);
+ if (elevator_find(e->elevator_name, e->uses_mq)) {
+ spin_unlock(&elv_list_lock);
+ if (e->icq_cache)
+ kmem_cache_destroy(e->icq_cache);
+ return -EBUSY;
+ }
+ list_add_tail(&e->list, &elv_list);
+ spin_unlock(&elv_list_lock);
+
+ /* print pretty message */
+ if (!strcmp(e->elevator_name, chosen_elevator) ||
+ (!*chosen_elevator &&
+ !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED)))
+ def = " (default)";
+
+ printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name,
+ def);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(elv_register);
+
+void elv_unregister(struct elevator_type *e)
+{
+ /* unregister */
+ spin_lock(&elv_list_lock);
+ list_del_init(&e->list);
+ spin_unlock(&elv_list_lock);
+
+ /*
+ * Destroy icq_cache if it exists. icq's are RCU managed. Make
+ * sure all RCU operations are complete before proceeding.
+ */
+ if (e->icq_cache) {
+ rcu_barrier();
+ kmem_cache_destroy(e->icq_cache);
+ e->icq_cache = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(elv_unregister);
+
+static int elevator_switch_mq(struct request_queue *q,
+ struct elevator_type *new_e)
+{
+ int ret;
+
+ blk_mq_freeze_queue(q);
+
+ if (q->elevator) {
+ if (q->elevator->registered)
+ elv_unregister_queue(q);
+ ioc_clear_queue(q);
+ elevator_exit(q, q->elevator);
+ }
+
+ ret = blk_mq_init_sched(q, new_e);
+ if (ret)
+ goto out;
+
+ if (new_e) {
+ ret = elv_register_queue(q);
+ if (ret) {
+ elevator_exit(q, q->elevator);
+ goto out;
+ }
+ }
+
+ if (new_e)
+ blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
+ else
+ blk_add_trace_msg(q, "elv switch: none");
+
+out:
+ blk_mq_unfreeze_queue(q);
+ return ret;
+}
+
+/*
+ * switch to new_e io scheduler. be careful not to introduce deadlocks -
+ * we don't free the old io scheduler, before we have allocated what we
+ * need for the new one. this way we have a chance of going back to the old
+ * one, if the new one fails init for some reason.
+ */
+static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
+{
+ struct elevator_queue *old = q->elevator;
+ bool old_registered = false;
+ int err;
+
+ if (q->mq_ops)
+ return elevator_switch_mq(q, new_e);
+
+ /*
+ * Turn on BYPASS and drain all requests w/ elevator private data.
+ * Block layer doesn't call into a quiesced elevator - all requests
+ * are directly put on the dispatch list without elevator data
+ * using INSERT_BACK. All requests have SOFTBARRIER set and no
+ * merge happens either.
+ */
+ if (old) {
+ old_registered = old->registered;
+
+ blk_queue_bypass_start(q);
+
+ /* unregister and clear all auxiliary data of the old elevator */
+ if (old_registered)
+ elv_unregister_queue(q);
+
+ ioc_clear_queue(q);
+ }
+
+ /* allocate, init and register new elevator */
+ err = new_e->ops.sq.elevator_init_fn(q, new_e);
+ if (err)
+ goto fail_init;
+
+ err = elv_register_queue(q);
+ if (err)
+ goto fail_register;
+
+ /* done, kill the old one and finish */
+ if (old) {
+ elevator_exit(q, old);
+ blk_queue_bypass_end(q);
+ }
+
+ blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
+
+ return 0;
+
+fail_register:
+ elevator_exit(q, q->elevator);
+fail_init:
+ /* switch failed, restore and re-register old elevator */
+ if (old) {
+ q->elevator = old;
+ elv_register_queue(q);
+ blk_queue_bypass_end(q);
+ }
+
+ return err;
+}
+
+/*
+ * Switch this queue to the given IO scheduler.
+ */
+static int __elevator_change(struct request_queue *q, const char *name)
+{
+ char elevator_name[ELV_NAME_MAX];
+ struct elevator_type *e;
+
+ /* Make sure queue is not in the middle of being removed */
+ if (!test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags))
+ return -ENOENT;
+
+ /*
+ * Special case for mq, turn off scheduling
+ */
+ if (q->mq_ops && !strncmp(name, "none", 4))
+ return elevator_switch(q, NULL);
+
+ strlcpy(elevator_name, name, sizeof(elevator_name));
+ e = elevator_get(q, strstrip(elevator_name), true);
+ if (!e)
+ return -EINVAL;
+
+ if (q->elevator &&
+ !strcmp(elevator_name, q->elevator->type->elevator_name)) {
+ elevator_put(e);
+ return 0;
+ }
+
+ return elevator_switch(q, e);
+}
+
+static inline bool elv_support_iosched(struct request_queue *q)
+{
+ if (q->mq_ops && q->tag_set && (q->tag_set->flags &
+ BLK_MQ_F_NO_SCHED))
+ return false;
+ return true;
+}
+
+ssize_t elv_iosched_store(struct request_queue *q, const char *name,
+ size_t count)
+{
+ int ret;
+
+ if (!(q->mq_ops || q->request_fn) || !elv_support_iosched(q))
+ return count;
+
+ ret = __elevator_change(q, name);
+ if (!ret)
+ return count;
+
+ return ret;
+}
+
+ssize_t elv_iosched_show(struct request_queue *q, char *name)
+{
+ struct elevator_queue *e = q->elevator;
+ struct elevator_type *elv = NULL;
+ struct elevator_type *__e;
+ int len = 0;
+
+ if (!blk_queue_stackable(q))
+ return sprintf(name, "none\n");
+
+ if (!q->elevator)
+ len += sprintf(name+len, "[none] ");
+ else
+ elv = e->type;
+
+ spin_lock(&elv_list_lock);
+ list_for_each_entry(__e, &elv_list, list) {
+ if (elv && !strcmp(elv->elevator_name, __e->elevator_name)) {
+ len += sprintf(name+len, "[%s] ", elv->elevator_name);
+ continue;
+ }
+ if (__e->uses_mq && q->mq_ops && elv_support_iosched(q))
+ len += sprintf(name+len, "%s ", __e->elevator_name);
+ else if (!__e->uses_mq && !q->mq_ops)
+ len += sprintf(name+len, "%s ", __e->elevator_name);
+ }
+ spin_unlock(&elv_list_lock);
+
+ if (q->mq_ops && q->elevator)
+ len += sprintf(name+len, "none");
+
+ len += sprintf(len+name, "\n");
+ return len;
+}
+
+struct request *elv_rb_former_request(struct request_queue *q,
+ struct request *rq)
+{
+ struct rb_node *rbprev = rb_prev(&rq->rb_node);
+
+ if (rbprev)
+ return rb_entry_rq(rbprev);
+
+ return NULL;
+}
+EXPORT_SYMBOL(elv_rb_former_request);
+
+struct request *elv_rb_latter_request(struct request_queue *q,
+ struct request *rq)
+{
+ struct rb_node *rbnext = rb_next(&rq->rb_node);
+
+ if (rbnext)
+ return rb_entry_rq(rbnext);
+
+ return NULL;
+}
+EXPORT_SYMBOL(elv_rb_latter_request);
diff --git a/src/kernel/linux/v4.14/block/genhd.c b/src/kernel/linux/v4.14/block/genhd.c
new file mode 100644
index 0000000..449ef56
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/genhd.c
@@ -0,0 +1,1969 @@
+/*
+ * gendisk handling
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/genhd.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/kmod.h>
+#include <linux/kobj_map.h>
+#include <linux/mutex.h>
+#include <linux/idr.h>
+#include <linux/log2.h>
+#include <linux/pm_runtime.h>
+#include <linux/badblocks.h>
+
+#include "blk.h"
+
+static DEFINE_MUTEX(block_class_lock);
+struct kobject *block_depr;
+
+/* for extended dynamic devt allocation, currently only one major is used */
+#define NR_EXT_DEVT (1 << MINORBITS)
+
+/* For extended devt allocation. ext_devt_lock prevents look up
+ * results from going away underneath its user.
+ */
+static DEFINE_SPINLOCK(ext_devt_lock);
+static DEFINE_IDR(ext_devt_idr);
+
+static const struct device_type disk_type;
+
+static void disk_check_events(struct disk_events *ev,
+ unsigned int *clearing_ptr);
+static void disk_alloc_events(struct gendisk *disk);
+static void disk_add_events(struct gendisk *disk);
+static void disk_del_events(struct gendisk *disk);
+static void disk_release_events(struct gendisk *disk);
+
+void part_inc_in_flight(struct request_queue *q, struct hd_struct *part, int rw)
+{
+ if (q->mq_ops)
+ return;
+
+ atomic_inc(&part->in_flight[rw]);
+ if (part->partno)
+ atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
+}
+
+void part_dec_in_flight(struct request_queue *q, struct hd_struct *part, int rw)
+{
+ if (q->mq_ops)
+ return;
+
+ atomic_dec(&part->in_flight[rw]);
+ if (part->partno)
+ atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
+}
+
+void part_in_flight(struct request_queue *q, struct hd_struct *part,
+ unsigned int inflight[2])
+{
+ if (q->mq_ops) {
+ blk_mq_in_flight(q, part, inflight);
+ return;
+ }
+
+ inflight[0] = atomic_read(&part->in_flight[0]) +
+ atomic_read(&part->in_flight[1]);
+ if (part->partno) {
+ part = &part_to_disk(part)->part0;
+ inflight[1] = atomic_read(&part->in_flight[0]) +
+ atomic_read(&part->in_flight[1]);
+ }
+}
+
+void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+ unsigned int inflight[2])
+{
+ if (q->mq_ops) {
+ blk_mq_in_flight_rw(q, part, inflight);
+ return;
+ }
+
+ inflight[0] = atomic_read(&part->in_flight[0]);
+ inflight[1] = atomic_read(&part->in_flight[1]);
+}
+
+struct hd_struct *__disk_get_part(struct gendisk *disk, int partno)
+{
+ struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
+
+ if (unlikely(partno < 0 || partno >= ptbl->len))
+ return NULL;
+ return rcu_dereference(ptbl->part[partno]);
+}
+
+/**
+ * disk_get_part - get partition
+ * @disk: disk to look partition from
+ * @partno: partition number
+ *
+ * Look for partition @partno from @disk. If found, increment
+ * reference count and return it.
+ *
+ * CONTEXT:
+ * Don't care.
+ *
+ * RETURNS:
+ * Pointer to the found partition on success, NULL if not found.
+ */
+struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
+{
+ struct hd_struct *part;
+
+ rcu_read_lock();
+ part = __disk_get_part(disk, partno);
+ if (part)
+ get_device(part_to_dev(part));
+ rcu_read_unlock();
+
+ return part;
+}
+EXPORT_SYMBOL_GPL(disk_get_part);
+
+/**
+ * disk_part_iter_init - initialize partition iterator
+ * @piter: iterator to initialize
+ * @disk: disk to iterate over
+ * @flags: DISK_PITER_* flags
+ *
+ * Initialize @piter so that it iterates over partitions of @disk.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
+ unsigned int flags)
+{
+ struct disk_part_tbl *ptbl;
+
+ rcu_read_lock();
+ ptbl = rcu_dereference(disk->part_tbl);
+
+ piter->disk = disk;
+ piter->part = NULL;
+
+ if (flags & DISK_PITER_REVERSE)
+ piter->idx = ptbl->len - 1;
+ else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
+ piter->idx = 0;
+ else
+ piter->idx = 1;
+
+ piter->flags = flags;
+
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(disk_part_iter_init);
+
+/**
+ * disk_part_iter_next - proceed iterator to the next partition and return it
+ * @piter: iterator of interest
+ *
+ * Proceed @piter to the next partition and return it.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
+{
+ struct disk_part_tbl *ptbl;
+ int inc, end;
+
+ /* put the last partition */
+ disk_put_part(piter->part);
+ piter->part = NULL;
+
+ /* get part_tbl */
+ rcu_read_lock();
+ ptbl = rcu_dereference(piter->disk->part_tbl);
+
+ /* determine iteration parameters */
+ if (piter->flags & DISK_PITER_REVERSE) {
+ inc = -1;
+ if (piter->flags & (DISK_PITER_INCL_PART0 |
+ DISK_PITER_INCL_EMPTY_PART0))
+ end = -1;
+ else
+ end = 0;
+ } else {
+ inc = 1;
+ end = ptbl->len;
+ }
+
+ /* iterate to the next partition */
+ for (; piter->idx != end; piter->idx += inc) {
+ struct hd_struct *part;
+
+ part = rcu_dereference(ptbl->part[piter->idx]);
+ if (!part)
+ continue;
+ if (!part_nr_sects_read(part) &&
+ !(piter->flags & DISK_PITER_INCL_EMPTY) &&
+ !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
+ piter->idx == 0))
+ continue;
+
+ get_device(part_to_dev(part));
+ piter->part = part;
+ piter->idx += inc;
+ break;
+ }
+
+ rcu_read_unlock();
+
+ return piter->part;
+}
+EXPORT_SYMBOL_GPL(disk_part_iter_next);
+
+/**
+ * disk_part_iter_exit - finish up partition iteration
+ * @piter: iter of interest
+ *
+ * Called when iteration is over. Cleans up @piter.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+void disk_part_iter_exit(struct disk_part_iter *piter)
+{
+ disk_put_part(piter->part);
+ piter->part = NULL;
+}
+EXPORT_SYMBOL_GPL(disk_part_iter_exit);
+
+static inline int sector_in_part(struct hd_struct *part, sector_t sector)
+{
+ return part->start_sect <= sector &&
+ sector < part->start_sect + part_nr_sects_read(part);
+}
+
+/**
+ * disk_map_sector_rcu - map sector to partition
+ * @disk: gendisk of interest
+ * @sector: sector to map
+ *
+ * Find out which partition @sector maps to on @disk. This is
+ * primarily used for stats accounting.
+ *
+ * CONTEXT:
+ * RCU read locked. The returned partition pointer is valid only
+ * while preemption is disabled.
+ *
+ * RETURNS:
+ * Found partition on success, part0 is returned if no partition matches
+ */
+struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
+{
+ struct disk_part_tbl *ptbl;
+ struct hd_struct *part;
+ int i;
+
+ ptbl = rcu_dereference(disk->part_tbl);
+
+ part = rcu_dereference(ptbl->last_lookup);
+ if (part && sector_in_part(part, sector))
+ return part;
+
+ for (i = 1; i < ptbl->len; i++) {
+ part = rcu_dereference(ptbl->part[i]);
+
+ if (part && sector_in_part(part, sector)) {
+ rcu_assign_pointer(ptbl->last_lookup, part);
+ return part;
+ }
+ }
+ return &disk->part0;
+}
+EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
+
+/*
+ * Can be deleted altogether. Later.
+ *
+ */
+#define BLKDEV_MAJOR_HASH_SIZE 255
+static struct blk_major_name {
+ struct blk_major_name *next;
+ int major;
+ char name[16];
+} *major_names[BLKDEV_MAJOR_HASH_SIZE];
+
+/* index in the above - for now: assume no multimajor ranges */
+static inline int major_to_index(unsigned major)
+{
+ return major % BLKDEV_MAJOR_HASH_SIZE;
+}
+
+#ifdef CONFIG_PROC_FS
+void blkdev_show(struct seq_file *seqf, off_t offset)
+{
+ struct blk_major_name *dp;
+
+ mutex_lock(&block_class_lock);
+ for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
+ if (dp->major == offset)
+ seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
+ mutex_unlock(&block_class_lock);
+}
+#endif /* CONFIG_PROC_FS */
+
+/**
+ * register_blkdev - register a new block device
+ *
+ * @major: the requested major device number [1..255]. If @major = 0, try to
+ * allocate any unused major number.
+ * @name: the name of the new block device as a zero terminated string
+ *
+ * The @name must be unique within the system.
+ *
+ * The return value depends on the @major input parameter:
+ *
+ * - if a major device number was requested in range [1..255] then the
+ * function returns zero on success, or a negative error code
+ * - if any unused major number was requested with @major = 0 parameter
+ * then the return value is the allocated major number in range
+ * [1..255] or a negative error code otherwise
+ */
+int register_blkdev(unsigned int major, const char *name)
+{
+ struct blk_major_name **n, *p;
+ int index, ret = 0;
+
+ mutex_lock(&block_class_lock);
+
+ /* temporary */
+ if (major == 0) {
+ for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
+ if (major_names[index] == NULL)
+ break;
+ }
+
+ if (index == 0) {
+ printk("register_blkdev: failed to get major for %s\n",
+ name);
+ ret = -EBUSY;
+ goto out;
+ }
+ major = index;
+ ret = major;
+ }
+
+ if (major >= BLKDEV_MAJOR_MAX) {
+ pr_err("register_blkdev: major requested (%d) is greater than the maximum (%d) for %s\n",
+ major, BLKDEV_MAJOR_MAX, name);
+
+ ret = -EINVAL;
+ goto out;
+ }
+
+ p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
+ if (p == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ p->major = major;
+ strlcpy(p->name, name, sizeof(p->name));
+ p->next = NULL;
+ index = major_to_index(major);
+
+ for (n = &major_names[index]; *n; n = &(*n)->next) {
+ if ((*n)->major == major)
+ break;
+ }
+ if (!*n)
+ *n = p;
+ else
+ ret = -EBUSY;
+
+ if (ret < 0) {
+ printk("register_blkdev: cannot get major %d for %s\n",
+ major, name);
+ kfree(p);
+ }
+out:
+ mutex_unlock(&block_class_lock);
+ return ret;
+}
+
+EXPORT_SYMBOL(register_blkdev);
+
+void unregister_blkdev(unsigned int major, const char *name)
+{
+ struct blk_major_name **n;
+ struct blk_major_name *p = NULL;
+ int index = major_to_index(major);
+
+ mutex_lock(&block_class_lock);
+ for (n = &major_names[index]; *n; n = &(*n)->next)
+ if ((*n)->major == major)
+ break;
+ if (!*n || strcmp((*n)->name, name)) {
+ WARN_ON(1);
+ } else {
+ p = *n;
+ *n = p->next;
+ }
+ mutex_unlock(&block_class_lock);
+ kfree(p);
+}
+
+EXPORT_SYMBOL(unregister_blkdev);
+
+static struct kobj_map *bdev_map;
+
+/**
+ * blk_mangle_minor - scatter minor numbers apart
+ * @minor: minor number to mangle
+ *
+ * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
+ * is enabled. Mangling twice gives the original value.
+ *
+ * RETURNS:
+ * Mangled value.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+static int blk_mangle_minor(int minor)
+{
+#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
+ int i;
+
+ for (i = 0; i < MINORBITS / 2; i++) {
+ int low = minor & (1 << i);
+ int high = minor & (1 << (MINORBITS - 1 - i));
+ int distance = MINORBITS - 1 - 2 * i;
+
+ minor ^= low | high; /* clear both bits */
+ low <<= distance; /* swap the positions */
+ high >>= distance;
+ minor |= low | high; /* and set */
+ }
+#endif
+ return minor;
+}
+
+/**
+ * blk_alloc_devt - allocate a dev_t for a partition
+ * @part: partition to allocate dev_t for
+ * @devt: out parameter for resulting dev_t
+ *
+ * Allocate a dev_t for block device.
+ *
+ * RETURNS:
+ * 0 on success, allocated dev_t is returned in *@devt. -errno on
+ * failure.
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
+{
+ struct gendisk *disk = part_to_disk(part);
+ int idx;
+
+ /* in consecutive minor range? */
+ if (part->partno < disk->minors) {
+ *devt = MKDEV(disk->major, disk->first_minor + part->partno);
+ return 0;
+ }
+
+ /* allocate ext devt */
+ idr_preload(GFP_KERNEL);
+
+ spin_lock_bh(&ext_devt_lock);
+ idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
+ spin_unlock_bh(&ext_devt_lock);
+
+ idr_preload_end();
+ if (idx < 0)
+ return idx == -ENOSPC ? -EBUSY : idx;
+
+ *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
+ return 0;
+}
+
+/**
+ * blk_free_devt - free a dev_t
+ * @devt: dev_t to free
+ *
+ * Free @devt which was allocated using blk_alloc_devt().
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void blk_free_devt(dev_t devt)
+{
+ if (devt == MKDEV(0, 0))
+ return;
+
+ if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
+ spin_lock_bh(&ext_devt_lock);
+ idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
+ spin_unlock_bh(&ext_devt_lock);
+ }
+}
+
+static char *bdevt_str(dev_t devt, char *buf)
+{
+ if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
+ char tbuf[BDEVT_SIZE];
+ snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
+ snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
+ } else
+ snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
+
+ return buf;
+}
+
+/*
+ * Register device numbers dev..(dev+range-1)
+ * range must be nonzero
+ * The hash chain is sorted on range, so that subranges can override.
+ */
+void blk_register_region(dev_t devt, unsigned long range, struct module *module,
+ struct kobject *(*probe)(dev_t, int *, void *),
+ int (*lock)(dev_t, void *), void *data)
+{
+ kobj_map(bdev_map, devt, range, module, probe, lock, data);
+}
+
+EXPORT_SYMBOL(blk_register_region);
+
+void blk_unregister_region(dev_t devt, unsigned long range)
+{
+ kobj_unmap(bdev_map, devt, range);
+}
+
+EXPORT_SYMBOL(blk_unregister_region);
+
+static struct kobject *exact_match(dev_t devt, int *partno, void *data)
+{
+ struct gendisk *p = data;
+
+ return &disk_to_dev(p)->kobj;
+}
+
+static int exact_lock(dev_t devt, void *data)
+{
+ struct gendisk *p = data;
+
+ if (!get_disk(p))
+ return -1;
+ return 0;
+}
+
+static void register_disk(struct device *parent, struct gendisk *disk)
+{
+ struct device *ddev = disk_to_dev(disk);
+ struct block_device *bdev;
+ struct disk_part_iter piter;
+ struct hd_struct *part;
+ int err;
+
+ ddev->parent = parent;
+
+ dev_set_name(ddev, "%s", disk->disk_name);
+
+ /* delay uevents, until we scanned partition table */
+ dev_set_uevent_suppress(ddev, 1);
+
+ if (device_add(ddev))
+ return;
+ if (!sysfs_deprecated) {
+ err = sysfs_create_link(block_depr, &ddev->kobj,
+ kobject_name(&ddev->kobj));
+ if (err) {
+ device_del(ddev);
+ return;
+ }
+ }
+
+ /*
+ * avoid probable deadlock caused by allocating memory with
+ * GFP_KERNEL in runtime_resume callback of its all ancestor
+ * devices
+ */
+ pm_runtime_set_memalloc_noio(ddev, true);
+
+ disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
+ disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
+
+ /* No minors to use for partitions */
+ if (!disk_part_scan_enabled(disk))
+ goto exit;
+
+ /* No such device (e.g., media were just removed) */
+ if (!get_capacity(disk))
+ goto exit;
+
+ bdev = bdget_disk(disk, 0);
+ if (!bdev)
+ goto exit;
+
+ bdev->bd_invalidated = 1;
+ err = blkdev_get(bdev, FMODE_READ, NULL);
+ if (err < 0)
+ goto exit;
+ blkdev_put(bdev, FMODE_READ);
+
+exit:
+ /* announce disk after possible partitions are created */
+ dev_set_uevent_suppress(ddev, 0);
+ kobject_uevent(&ddev->kobj, KOBJ_ADD);
+
+ /* announce possible partitions */
+ disk_part_iter_init(&piter, disk, 0);
+ while ((part = disk_part_iter_next(&piter)))
+ kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
+ disk_part_iter_exit(&piter);
+}
+
+/**
+ * device_add_disk - add partitioning information to kernel list
+ * @parent: parent device for the disk
+ * @disk: per-device partitioning information
+ *
+ * This function registers the partitioning information in @disk
+ * with the kernel.
+ *
+ * FIXME: error handling
+ */
+void device_add_disk(struct device *parent, struct gendisk *disk)
+{
+ struct backing_dev_info *bdi;
+ dev_t devt;
+ int retval;
+
+ /* minors == 0 indicates to use ext devt from part0 and should
+ * be accompanied with EXT_DEVT flag. Make sure all
+ * parameters make sense.
+ */
+ WARN_ON(disk->minors && !(disk->major || disk->first_minor));
+ WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));
+
+ disk->flags |= GENHD_FL_UP;
+
+ retval = blk_alloc_devt(&disk->part0, &devt);
+ if (retval) {
+ WARN_ON(1);
+ return;
+ }
+ disk_to_dev(disk)->devt = devt;
+
+ /* ->major and ->first_minor aren't supposed to be
+ * dereferenced from here on, but set them just in case.
+ */
+ disk->major = MAJOR(devt);
+ disk->first_minor = MINOR(devt);
+
+ disk_alloc_events(disk);
+
+ /* Register BDI before referencing it from bdev */
+ bdi = disk->queue->backing_dev_info;
+ bdi_register_owner(bdi, disk_to_dev(disk));
+
+ blk_register_region(disk_devt(disk), disk->minors, NULL,
+ exact_match, exact_lock, disk);
+ register_disk(parent, disk);
+ blk_register_queue(disk);
+
+ /*
+ * Take an extra ref on queue which will be put on disk_release()
+ * so that it sticks around as long as @disk is there.
+ */
+ WARN_ON_ONCE(!blk_get_queue(disk->queue));
+
+ retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
+ "bdi");
+ WARN_ON(retval);
+
+ disk_add_events(disk);
+ blk_integrity_add(disk);
+}
+EXPORT_SYMBOL(device_add_disk);
+
+void del_gendisk(struct gendisk *disk)
+{
+ struct disk_part_iter piter;
+ struct hd_struct *part;
+
+ blk_integrity_del(disk);
+ disk_del_events(disk);
+
+ /* invalidate stuff */
+ disk_part_iter_init(&piter, disk,
+ DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
+ while ((part = disk_part_iter_next(&piter))) {
+ invalidate_partition(disk, part->partno);
+ bdev_unhash_inode(part_devt(part));
+ delete_partition(disk, part->partno);
+ }
+ disk_part_iter_exit(&piter);
+
+ invalidate_partition(disk, 0);
+ bdev_unhash_inode(disk_devt(disk));
+ set_capacity(disk, 0);
+ disk->flags &= ~GENHD_FL_UP;
+
+ sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
+ if (disk->queue) {
+ /*
+ * Unregister bdi before releasing device numbers (as they can
+ * get reused and we'd get clashes in sysfs).
+ */
+ bdi_unregister(disk->queue->backing_dev_info);
+ blk_unregister_queue(disk);
+ } else {
+ WARN_ON(1);
+ }
+ blk_unregister_region(disk_devt(disk), disk->minors);
+
+ part_stat_set_all(&disk->part0, 0);
+ disk->part0.stamp = 0;
+
+ kobject_put(disk->part0.holder_dir);
+ kobject_put(disk->slave_dir);
+ if (!sysfs_deprecated)
+ sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
+ pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
+ device_del(disk_to_dev(disk));
+}
+EXPORT_SYMBOL(del_gendisk);
+
+/* sysfs access to bad-blocks list. */
+static ssize_t disk_badblocks_show(struct device *dev,
+ struct device_attribute *attr,
+ char *page)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ if (!disk->bb)
+ return sprintf(page, "\n");
+
+ return badblocks_show(disk->bb, page, 0);
+}
+
+static ssize_t disk_badblocks_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *page, size_t len)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ if (!disk->bb)
+ return -ENXIO;
+
+ return badblocks_store(disk->bb, page, len, 0);
+}
+
+/**
+ * get_gendisk - get partitioning information for a given device
+ * @devt: device to get partitioning information for
+ * @partno: returned partition index
+ *
+ * This function gets the structure containing partitioning
+ * information for the given device @devt.
+ */
+struct gendisk *get_gendisk(dev_t devt, int *partno)
+{
+ struct gendisk *disk = NULL;
+
+ if (MAJOR(devt) != BLOCK_EXT_MAJOR) {
+ struct kobject *kobj;
+
+ kobj = kobj_lookup(bdev_map, devt, partno);
+ if (kobj)
+ disk = dev_to_disk(kobj_to_dev(kobj));
+ } else {
+ struct hd_struct *part;
+
+ spin_lock_bh(&ext_devt_lock);
+ part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
+ if (part && get_disk(part_to_disk(part))) {
+ *partno = part->partno;
+ disk = part_to_disk(part);
+ }
+ spin_unlock_bh(&ext_devt_lock);
+ }
+
+ return disk;
+}
+EXPORT_SYMBOL(get_gendisk);
+
+/**
+ * bdget_disk - do bdget() by gendisk and partition number
+ * @disk: gendisk of interest
+ * @partno: partition number
+ *
+ * Find partition @partno from @disk, do bdget() on it.
+ *
+ * CONTEXT:
+ * Don't care.
+ *
+ * RETURNS:
+ * Resulting block_device on success, NULL on failure.
+ */
+struct block_device *bdget_disk(struct gendisk *disk, int partno)
+{
+ struct hd_struct *part;
+ struct block_device *bdev = NULL;
+
+ part = disk_get_part(disk, partno);
+ if (part)
+ bdev = bdget(part_devt(part));
+ disk_put_part(part);
+
+ return bdev;
+}
+EXPORT_SYMBOL(bdget_disk);
+
+/*
+ * print a full list of all partitions - intended for places where the root
+ * filesystem can't be mounted and thus to give the victim some idea of what
+ * went wrong
+ */
+void __init printk_all_partitions(void)
+{
+ struct class_dev_iter iter;
+ struct device *dev;
+
+ class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
+ while ((dev = class_dev_iter_next(&iter))) {
+ struct gendisk *disk = dev_to_disk(dev);
+ struct disk_part_iter piter;
+ struct hd_struct *part;
+ char name_buf[BDEVNAME_SIZE];
+ char devt_buf[BDEVT_SIZE];
+
+ /*
+ * Don't show empty devices or things that have been
+ * suppressed
+ */
+ if (get_capacity(disk) == 0 ||
+ (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
+ continue;
+
+ /*
+ * Note, unlike /proc/partitions, I am showing the
+ * numbers in hex - the same format as the root=
+ * option takes.
+ */
+ disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
+ while ((part = disk_part_iter_next(&piter))) {
+ bool is_part0 = part == &disk->part0;
+
+ printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
+ bdevt_str(part_devt(part), devt_buf),
+ (unsigned long long)part_nr_sects_read(part) >> 1
+ , disk_name(disk, part->partno, name_buf),
+ part->info ? part->info->uuid : "");
+ if (is_part0) {
+ if (dev->parent && dev->parent->driver)
+ printk(" driver: %s\n",
+ dev->parent->driver->name);
+ else
+ printk(" (driver?)\n");
+ } else
+ printk("\n");
+ }
+ disk_part_iter_exit(&piter);
+ }
+ class_dev_iter_exit(&iter);
+}
+
+#ifdef CONFIG_PROC_FS
+/* iterator */
+static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
+{
+ loff_t skip = *pos;
+ struct class_dev_iter *iter;
+ struct device *dev;
+
+ iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return ERR_PTR(-ENOMEM);
+
+ seqf->private = iter;
+ class_dev_iter_init(iter, &block_class, NULL, &disk_type);
+ do {
+ dev = class_dev_iter_next(iter);
+ if (!dev)
+ return NULL;
+ } while (skip--);
+
+ return dev_to_disk(dev);
+}
+
+static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
+{
+ struct device *dev;
+
+ (*pos)++;
+ dev = class_dev_iter_next(seqf->private);
+ if (dev)
+ return dev_to_disk(dev);
+
+ return NULL;
+}
+
+static void disk_seqf_stop(struct seq_file *seqf, void *v)
+{
+ struct class_dev_iter *iter = seqf->private;
+
+ /* stop is called even after start failed :-( */
+ if (iter) {
+ class_dev_iter_exit(iter);
+ kfree(iter);
+ seqf->private = NULL;
+ }
+}
+
+static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
+{
+ void *p;
+
+ p = disk_seqf_start(seqf, pos);
+ if (!IS_ERR_OR_NULL(p) && !*pos)
+ seq_puts(seqf, "major minor #blocks name\n\n");
+ return p;
+}
+
+static int show_partition(struct seq_file *seqf, void *v)
+{
+ struct gendisk *sgp = v;
+ struct disk_part_iter piter;
+ struct hd_struct *part;
+ char buf[BDEVNAME_SIZE];
+
+ /* Don't show non-partitionable removeable devices or empty devices */
+ if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
+ (sgp->flags & GENHD_FL_REMOVABLE)))
+ return 0;
+ if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
+ return 0;
+
+ /* show the full disk and all non-0 size partitions of it */
+ disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
+ while ((part = disk_part_iter_next(&piter)))
+ seq_printf(seqf, "%4d %7d %10llu %s\n",
+ MAJOR(part_devt(part)), MINOR(part_devt(part)),
+ (unsigned long long)part_nr_sects_read(part) >> 1,
+ disk_name(sgp, part->partno, buf));
+ disk_part_iter_exit(&piter);
+
+ return 0;
+}
+
+static const struct seq_operations partitions_op = {
+ .start = show_partition_start,
+ .next = disk_seqf_next,
+ .stop = disk_seqf_stop,
+ .show = show_partition
+};
+
+static int partitions_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &partitions_op);
+}
+
+static const struct file_operations proc_partitions_operations = {
+ .open = partitions_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+#endif
+
+
+static struct kobject *base_probe(dev_t devt, int *partno, void *data)
+{
+ if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
+ /* Make old-style 2.4 aliases work */
+ request_module("block-major-%d", MAJOR(devt));
+ return NULL;
+}
+
+static int __init genhd_device_init(void)
+{
+ int error;
+
+ block_class.dev_kobj = sysfs_dev_block_kobj;
+ error = class_register(&block_class);
+ if (unlikely(error))
+ return error;
+ bdev_map = kobj_map_init(base_probe, &block_class_lock);
+ blk_dev_init();
+
+ register_blkdev(BLOCK_EXT_MAJOR, "blkext");
+
+ /* create top-level block dir */
+ if (!sysfs_deprecated)
+ block_depr = kobject_create_and_add("block", NULL);
+ return 0;
+}
+
+subsys_initcall(genhd_device_init);
+
+static ssize_t disk_range_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%d\n", disk->minors);
+}
+
+static ssize_t disk_ext_range_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%d\n", disk_max_parts(disk));
+}
+
+static ssize_t disk_removable_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%d\n",
+ (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
+}
+
+static ssize_t disk_ro_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
+}
+
+static ssize_t disk_capability_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%x\n", disk->flags);
+}
+
+static ssize_t disk_alignment_offset_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
+}
+
+static ssize_t disk_discard_alignment_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
+}
+
+static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
+static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
+static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
+static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
+static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
+static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL);
+static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show,
+ NULL);
+static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
+static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
+static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
+static DEVICE_ATTR(badblocks, S_IRUGO | S_IWUSR, disk_badblocks_show,
+ disk_badblocks_store);
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+static struct device_attribute dev_attr_fail =
+ __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
+#endif
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+static struct device_attribute dev_attr_fail_timeout =
+ __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show,
+ part_timeout_store);
+#endif
+
+static struct attribute *disk_attrs[] = {
+ &dev_attr_range.attr,
+ &dev_attr_ext_range.attr,
+ &dev_attr_removable.attr,
+ &dev_attr_ro.attr,
+ &dev_attr_size.attr,
+ &dev_attr_alignment_offset.attr,
+ &dev_attr_discard_alignment.attr,
+ &dev_attr_capability.attr,
+ &dev_attr_stat.attr,
+ &dev_attr_inflight.attr,
+ &dev_attr_badblocks.attr,
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+ &dev_attr_fail.attr,
+#endif
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+ &dev_attr_fail_timeout.attr,
+#endif
+ NULL
+};
+
+static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+ struct device *dev = container_of(kobj, typeof(*dev), kobj);
+ struct gendisk *disk = dev_to_disk(dev);
+
+ if (a == &dev_attr_badblocks.attr && !disk->bb)
+ return 0;
+ return a->mode;
+}
+
+static struct attribute_group disk_attr_group = {
+ .attrs = disk_attrs,
+ .is_visible = disk_visible,
+};
+
+static const struct attribute_group *disk_attr_groups[] = {
+ &disk_attr_group,
+ NULL
+};
+
+/**
+ * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
+ * @disk: disk to replace part_tbl for
+ * @new_ptbl: new part_tbl to install
+ *
+ * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
+ * original ptbl is freed using RCU callback.
+ *
+ * LOCKING:
+ * Matching bd_mutex locked or the caller is the only user of @disk.
+ */
+static void disk_replace_part_tbl(struct gendisk *disk,
+ struct disk_part_tbl *new_ptbl)
+{
+ struct disk_part_tbl *old_ptbl =
+ rcu_dereference_protected(disk->part_tbl, 1);
+
+ rcu_assign_pointer(disk->part_tbl, new_ptbl);
+
+ if (old_ptbl) {
+ rcu_assign_pointer(old_ptbl->last_lookup, NULL);
+ kfree_rcu(old_ptbl, rcu_head);
+ }
+}
+
+/**
+ * disk_expand_part_tbl - expand disk->part_tbl
+ * @disk: disk to expand part_tbl for
+ * @partno: expand such that this partno can fit in
+ *
+ * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
+ * uses RCU to allow unlocked dereferencing for stats and other stuff.
+ *
+ * LOCKING:
+ * Matching bd_mutex locked or the caller is the only user of @disk.
+ * Might sleep.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int disk_expand_part_tbl(struct gendisk *disk, int partno)
+{
+ struct disk_part_tbl *old_ptbl =
+ rcu_dereference_protected(disk->part_tbl, 1);
+ struct disk_part_tbl *new_ptbl;
+ int len = old_ptbl ? old_ptbl->len : 0;
+ int i, target;
+ size_t size;
+
+ /*
+ * check for int overflow, since we can get here from blkpg_ioctl()
+ * with a user passed 'partno'.
+ */
+ target = partno + 1;
+ if (target < 0)
+ return -EINVAL;
+
+ /* disk_max_parts() is zero during initialization, ignore if so */
+ if (disk_max_parts(disk) && target > disk_max_parts(disk))
+ return -EINVAL;
+
+ if (target <= len)
+ return 0;
+
+ size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
+ new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
+ if (!new_ptbl)
+ return -ENOMEM;
+
+ new_ptbl->len = target;
+
+ for (i = 0; i < len; i++)
+ rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
+
+ disk_replace_part_tbl(disk, new_ptbl);
+ return 0;
+}
+
+static void disk_release(struct device *dev)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ blk_free_devt(dev->devt);
+ disk_release_events(disk);
+ kfree(disk->random);
+ disk_replace_part_tbl(disk, NULL);
+ hd_free_part(&disk->part0);
+ if (disk->queue)
+ blk_put_queue(disk->queue);
+ kfree(disk);
+}
+struct class block_class = {
+ .name = "block",
+};
+
+static char *block_devnode(struct device *dev, umode_t *mode,
+ kuid_t *uid, kgid_t *gid)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ if (disk->devnode)
+ return disk->devnode(disk, mode);
+ return NULL;
+}
+
+static const struct device_type disk_type = {
+ .name = "disk",
+ .groups = disk_attr_groups,
+ .release = disk_release,
+ .devnode = block_devnode,
+};
+
+#ifdef CONFIG_PROC_FS
+/*
+ * aggregate disk stat collector. Uses the same stats that the sysfs
+ * entries do, above, but makes them available through one seq_file.
+ *
+ * The output looks suspiciously like /proc/partitions with a bunch of
+ * extra fields.
+ */
+static int diskstats_show(struct seq_file *seqf, void *v)
+{
+ struct gendisk *gp = v;
+ struct disk_part_iter piter;
+ struct hd_struct *hd;
+ char buf[BDEVNAME_SIZE];
+ unsigned int inflight[2];
+ int cpu;
+
+ /*
+ if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
+ seq_puts(seqf, "major minor name"
+ " rio rmerge rsect ruse wio wmerge "
+ "wsect wuse running use aveq"
+ "\n\n");
+ */
+
+ disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
+ while ((hd = disk_part_iter_next(&piter))) {
+ cpu = part_stat_lock();
+ part_round_stats(gp->queue, cpu, hd);
+ part_stat_unlock();
+ part_in_flight(gp->queue, hd, inflight);
+ seq_printf(seqf, "%4d %7d %s %lu %lu %lu "
+ "%u %lu %lu %lu %u %u %u %u\n",
+ MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
+ disk_name(gp, hd->partno, buf),
+ part_stat_read(hd, ios[READ]),
+ part_stat_read(hd, merges[READ]),
+ part_stat_read(hd, sectors[READ]),
+ jiffies_to_msecs(part_stat_read(hd, ticks[READ])),
+ part_stat_read(hd, ios[WRITE]),
+ part_stat_read(hd, merges[WRITE]),
+ part_stat_read(hd, sectors[WRITE]),
+ jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])),
+ inflight[0],
+ jiffies_to_msecs(part_stat_read(hd, io_ticks)),
+ jiffies_to_msecs(part_stat_read(hd, time_in_queue))
+ );
+ }
+ disk_part_iter_exit(&piter);
+
+ return 0;
+}
+
+static const struct seq_operations diskstats_op = {
+ .start = disk_seqf_start,
+ .next = disk_seqf_next,
+ .stop = disk_seqf_stop,
+ .show = diskstats_show
+};
+
+static int diskstats_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &diskstats_op);
+}
+
+static const struct file_operations proc_diskstats_operations = {
+ .open = diskstats_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int __init proc_genhd_init(void)
+{
+ proc_create("diskstats", 0, NULL, &proc_diskstats_operations);
+ proc_create("partitions", 0, NULL, &proc_partitions_operations);
+ return 0;
+}
+module_init(proc_genhd_init);
+#endif /* CONFIG_PROC_FS */
+
+dev_t blk_lookup_devt(const char *name, int partno)
+{
+ dev_t devt = MKDEV(0, 0);
+ struct class_dev_iter iter;
+ struct device *dev;
+
+ class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
+ while ((dev = class_dev_iter_next(&iter))) {
+ struct gendisk *disk = dev_to_disk(dev);
+ struct hd_struct *part;
+
+ if (strcmp(dev_name(dev), name))
+ continue;
+
+ if (partno < disk->minors) {
+ /* We need to return the right devno, even
+ * if the partition doesn't exist yet.
+ */
+ devt = MKDEV(MAJOR(dev->devt),
+ MINOR(dev->devt) + partno);
+ break;
+ }
+ part = disk_get_part(disk, partno);
+ if (part) {
+ devt = part_devt(part);
+ disk_put_part(part);
+ break;
+ }
+ disk_put_part(part);
+ }
+ class_dev_iter_exit(&iter);
+ return devt;
+}
+EXPORT_SYMBOL(blk_lookup_devt);
+
+struct gendisk *alloc_disk(int minors)
+{
+ return alloc_disk_node(minors, NUMA_NO_NODE);
+}
+EXPORT_SYMBOL(alloc_disk);
+
+struct gendisk *alloc_disk_node(int minors, int node_id)
+{
+ struct gendisk *disk;
+ struct disk_part_tbl *ptbl;
+
+ if (minors > DISK_MAX_PARTS) {
+ printk(KERN_ERR
+ "block: can't allocated more than %d partitions\n",
+ DISK_MAX_PARTS);
+ minors = DISK_MAX_PARTS;
+ }
+
+ disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
+ if (disk) {
+ if (!init_part_stats(&disk->part0)) {
+ kfree(disk);
+ return NULL;
+ }
+ disk->node_id = node_id;
+ if (disk_expand_part_tbl(disk, 0)) {
+ free_part_stats(&disk->part0);
+ kfree(disk);
+ return NULL;
+ }
+ ptbl = rcu_dereference_protected(disk->part_tbl, 1);
+ rcu_assign_pointer(ptbl->part[0], &disk->part0);
+
+ /*
+ * set_capacity() and get_capacity() currently don't use
+ * seqcounter to read/update the part0->nr_sects. Still init
+ * the counter as we can read the sectors in IO submission
+ * patch using seqence counters.
+ *
+ * TODO: Ideally set_capacity() and get_capacity() should be
+ * converted to make use of bd_mutex and sequence counters.
+ */
+ seqcount_init(&disk->part0.nr_sects_seq);
+ if (hd_ref_init(&disk->part0)) {
+ hd_free_part(&disk->part0);
+ kfree(disk);
+ return NULL;
+ }
+
+ disk->minors = minors;
+ rand_initialize_disk(disk);
+ disk_to_dev(disk)->class = &block_class;
+ disk_to_dev(disk)->type = &disk_type;
+ device_initialize(disk_to_dev(disk));
+ }
+ return disk;
+}
+EXPORT_SYMBOL(alloc_disk_node);
+
+struct kobject *get_disk(struct gendisk *disk)
+{
+ struct module *owner;
+ struct kobject *kobj;
+
+ if (!disk->fops)
+ return NULL;
+ owner = disk->fops->owner;
+ if (owner && !try_module_get(owner))
+ return NULL;
+ kobj = kobject_get_unless_zero(&disk_to_dev(disk)->kobj);
+ if (kobj == NULL) {
+ module_put(owner);
+ return NULL;
+ }
+ return kobj;
+
+}
+
+EXPORT_SYMBOL(get_disk);
+
+void put_disk(struct gendisk *disk)
+{
+ if (disk)
+ kobject_put(&disk_to_dev(disk)->kobj);
+}
+
+EXPORT_SYMBOL(put_disk);
+
+static void set_disk_ro_uevent(struct gendisk *gd, int ro)
+{
+ char event[] = "DISK_RO=1";
+ char *envp[] = { event, NULL };
+
+ if (!ro)
+ event[8] = '0';
+ kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
+}
+
+void set_device_ro(struct block_device *bdev, int flag)
+{
+ bdev->bd_part->policy = flag;
+}
+
+EXPORT_SYMBOL(set_device_ro);
+
+void set_disk_ro(struct gendisk *disk, int flag)
+{
+ struct disk_part_iter piter;
+ struct hd_struct *part;
+
+ if (disk->part0.policy != flag) {
+ set_disk_ro_uevent(disk, flag);
+ disk->part0.policy = flag;
+ }
+
+ disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
+ while ((part = disk_part_iter_next(&piter)))
+ part->policy = flag;
+ disk_part_iter_exit(&piter);
+}
+
+EXPORT_SYMBOL(set_disk_ro);
+
+int bdev_read_only(struct block_device *bdev)
+{
+ if (!bdev)
+ return 0;
+ return bdev->bd_part->policy;
+}
+
+EXPORT_SYMBOL(bdev_read_only);
+
+int invalidate_partition(struct gendisk *disk, int partno)
+{
+ int res = 0;
+ struct block_device *bdev = bdget_disk(disk, partno);
+ if (bdev) {
+ fsync_bdev(bdev);
+ res = __invalidate_device(bdev, true);
+ bdput(bdev);
+ }
+ return res;
+}
+
+EXPORT_SYMBOL(invalidate_partition);
+
+/*
+ * Disk events - monitor disk events like media change and eject request.
+ */
+struct disk_events {
+ struct list_head node; /* all disk_event's */
+ struct gendisk *disk; /* the associated disk */
+ spinlock_t lock;
+
+ struct mutex block_mutex; /* protects blocking */
+ int block; /* event blocking depth */
+ unsigned int pending; /* events already sent out */
+ unsigned int clearing; /* events being cleared */
+
+ long poll_msecs; /* interval, -1 for default */
+ struct delayed_work dwork;
+};
+
+static const char *disk_events_strs[] = {
+ [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
+ [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
+};
+
+static char *disk_uevents[] = {
+ [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
+ [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
+};
+
+/* list of all disk_events */
+static DEFINE_MUTEX(disk_events_mutex);
+static LIST_HEAD(disk_events);
+
+/* disable in-kernel polling by default */
+static unsigned long disk_events_dfl_poll_msecs;
+
+static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
+{
+ struct disk_events *ev = disk->ev;
+ long intv_msecs = 0;
+
+ /*
+ * If device-specific poll interval is set, always use it. If
+ * the default is being used, poll iff there are events which
+ * can't be monitored asynchronously.
+ */
+ if (ev->poll_msecs >= 0)
+ intv_msecs = ev->poll_msecs;
+ else if (disk->events & ~disk->async_events)
+ intv_msecs = disk_events_dfl_poll_msecs;
+
+ return msecs_to_jiffies(intv_msecs);
+}
+
+/**
+ * disk_block_events - block and flush disk event checking
+ * @disk: disk to block events for
+ *
+ * On return from this function, it is guaranteed that event checking
+ * isn't in progress and won't happen until unblocked by
+ * disk_unblock_events(). Events blocking is counted and the actual
+ * unblocking happens after the matching number of unblocks are done.
+ *
+ * Note that this intentionally does not block event checking from
+ * disk_clear_events().
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void disk_block_events(struct gendisk *disk)
+{
+ struct disk_events *ev = disk->ev;
+ unsigned long flags;
+ bool cancel;
+
+ if (!ev)
+ return;
+
+ /*
+ * Outer mutex ensures that the first blocker completes canceling
+ * the event work before further blockers are allowed to finish.
+ */
+ mutex_lock(&ev->block_mutex);
+
+ spin_lock_irqsave(&ev->lock, flags);
+ cancel = !ev->block++;
+ spin_unlock_irqrestore(&ev->lock, flags);
+
+ if (cancel)
+ cancel_delayed_work_sync(&disk->ev->dwork);
+
+ mutex_unlock(&ev->block_mutex);
+}
+
+static void __disk_unblock_events(struct gendisk *disk, bool check_now)
+{
+ struct disk_events *ev = disk->ev;
+ unsigned long intv;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ev->lock, flags);
+
+ if (WARN_ON_ONCE(ev->block <= 0))
+ goto out_unlock;
+
+ if (--ev->block)
+ goto out_unlock;
+
+ intv = disk_events_poll_jiffies(disk);
+ if (check_now)
+ queue_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, 0);
+ else if (intv)
+ queue_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, intv);
+out_unlock:
+ spin_unlock_irqrestore(&ev->lock, flags);
+}
+
+/**
+ * disk_unblock_events - unblock disk event checking
+ * @disk: disk to unblock events for
+ *
+ * Undo disk_block_events(). When the block count reaches zero, it
+ * starts events polling if configured.
+ *
+ * CONTEXT:
+ * Don't care. Safe to call from irq context.
+ */
+void disk_unblock_events(struct gendisk *disk)
+{
+ if (disk->ev)
+ __disk_unblock_events(disk, false);
+}
+
+/**
+ * disk_flush_events - schedule immediate event checking and flushing
+ * @disk: disk to check and flush events for
+ * @mask: events to flush
+ *
+ * Schedule immediate event checking on @disk if not blocked. Events in
+ * @mask are scheduled to be cleared from the driver. Note that this
+ * doesn't clear the events from @disk->ev.
+ *
+ * CONTEXT:
+ * If @mask is non-zero must be called with bdev->bd_mutex held.
+ */
+void disk_flush_events(struct gendisk *disk, unsigned int mask)
+{
+ struct disk_events *ev = disk->ev;
+
+ if (!ev)
+ return;
+
+ spin_lock_irq(&ev->lock);
+ ev->clearing |= mask;
+ if (!ev->block)
+ mod_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, 0);
+ spin_unlock_irq(&ev->lock);
+}
+
+/**
+ * disk_clear_events - synchronously check, clear and return pending events
+ * @disk: disk to fetch and clear events from
+ * @mask: mask of events to be fetched and cleared
+ *
+ * Disk events are synchronously checked and pending events in @mask
+ * are cleared and returned. This ignores the block count.
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
+{
+ const struct block_device_operations *bdops = disk->fops;
+ struct disk_events *ev = disk->ev;
+ unsigned int pending;
+ unsigned int clearing = mask;
+
+ if (!ev) {
+ /* for drivers still using the old ->media_changed method */
+ if ((mask & DISK_EVENT_MEDIA_CHANGE) &&
+ bdops->media_changed && bdops->media_changed(disk))
+ return DISK_EVENT_MEDIA_CHANGE;
+ return 0;
+ }
+
+ disk_block_events(disk);
+
+ /*
+ * store the union of mask and ev->clearing on the stack so that the
+ * race with disk_flush_events does not cause ambiguity (ev->clearing
+ * can still be modified even if events are blocked).
+ */
+ spin_lock_irq(&ev->lock);
+ clearing |= ev->clearing;
+ ev->clearing = 0;
+ spin_unlock_irq(&ev->lock);
+
+ disk_check_events(ev, &clearing);
+ /*
+ * if ev->clearing is not 0, the disk_flush_events got called in the
+ * middle of this function, so we want to run the workfn without delay.
+ */
+ __disk_unblock_events(disk, ev->clearing ? true : false);
+
+ /* then, fetch and clear pending events */
+ spin_lock_irq(&ev->lock);
+ pending = ev->pending & mask;
+ ev->pending &= ~mask;
+ spin_unlock_irq(&ev->lock);
+ WARN_ON_ONCE(clearing & mask);
+
+ return pending;
+}
+
+/*
+ * Separate this part out so that a different pointer for clearing_ptr can be
+ * passed in for disk_clear_events.
+ */
+static void disk_events_workfn(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
+
+ disk_check_events(ev, &ev->clearing);
+}
+
+static void disk_check_events(struct disk_events *ev,
+ unsigned int *clearing_ptr)
+{
+ struct gendisk *disk = ev->disk;
+ char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
+ unsigned int clearing = *clearing_ptr;
+ unsigned int events;
+ unsigned long intv;
+ int nr_events = 0, i;
+
+ /* check events */
+ events = disk->fops->check_events(disk, clearing);
+
+ /* accumulate pending events and schedule next poll if necessary */
+ spin_lock_irq(&ev->lock);
+
+ events &= ~ev->pending;
+ ev->pending |= events;
+ *clearing_ptr &= ~clearing;
+
+ intv = disk_events_poll_jiffies(disk);
+ if (!ev->block && intv)
+ queue_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, intv);
+
+ spin_unlock_irq(&ev->lock);
+
+ /*
+ * Tell userland about new events. Only the events listed in
+ * @disk->events are reported. Unlisted events are processed the
+ * same internally but never get reported to userland.
+ */
+ for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
+ if (events & disk->events & (1 << i))
+ envp[nr_events++] = disk_uevents[i];
+
+ if (nr_events)
+ kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
+}
+
+/*
+ * A disk events enabled device has the following sysfs nodes under
+ * its /sys/block/X/ directory.
+ *
+ * events : list of all supported events
+ * events_async : list of events which can be detected w/o polling
+ * events_poll_msecs : polling interval, 0: disable, -1: system default
+ */
+static ssize_t __disk_events_show(unsigned int events, char *buf)
+{
+ const char *delim = "";
+ ssize_t pos = 0;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
+ if (events & (1 << i)) {
+ pos += sprintf(buf + pos, "%s%s",
+ delim, disk_events_strs[i]);
+ delim = " ";
+ }
+ if (pos)
+ pos += sprintf(buf + pos, "\n");
+ return pos;
+}
+
+static ssize_t disk_events_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return __disk_events_show(disk->events, buf);
+}
+
+static ssize_t disk_events_async_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return __disk_events_show(disk->async_events, buf);
+}
+
+static ssize_t disk_events_poll_msecs_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
+}
+
+static ssize_t disk_events_poll_msecs_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ long intv;
+
+ if (!count || !sscanf(buf, "%ld", &intv))
+ return -EINVAL;
+
+ if (intv < 0 && intv != -1)
+ return -EINVAL;
+
+ disk_block_events(disk);
+ disk->ev->poll_msecs = intv;
+ __disk_unblock_events(disk, true);
+
+ return count;
+}
+
+static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL);
+static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL);
+static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR,
+ disk_events_poll_msecs_show,
+ disk_events_poll_msecs_store);
+
+static const struct attribute *disk_events_attrs[] = {
+ &dev_attr_events.attr,
+ &dev_attr_events_async.attr,
+ &dev_attr_events_poll_msecs.attr,
+ NULL,
+};
+
+/*
+ * The default polling interval can be specified by the kernel
+ * parameter block.events_dfl_poll_msecs which defaults to 0
+ * (disable). This can also be modified runtime by writing to
+ * /sys/module/block/events_dfl_poll_msecs.
+ */
+static int disk_events_set_dfl_poll_msecs(const char *val,
+ const struct kernel_param *kp)
+{
+ struct disk_events *ev;
+ int ret;
+
+ ret = param_set_ulong(val, kp);
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&disk_events_mutex);
+
+ list_for_each_entry(ev, &disk_events, node)
+ disk_flush_events(ev->disk, 0);
+
+ mutex_unlock(&disk_events_mutex);
+
+ return 0;
+}
+
+static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
+ .set = disk_events_set_dfl_poll_msecs,
+ .get = param_get_ulong,
+};
+
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "block."
+
+module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
+ &disk_events_dfl_poll_msecs, 0644);
+
+/*
+ * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
+ */
+static void disk_alloc_events(struct gendisk *disk)
+{
+ struct disk_events *ev;
+
+ if (!disk->fops->check_events)
+ return;
+
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev) {
+ pr_warn("%s: failed to initialize events\n", disk->disk_name);
+ return;
+ }
+
+ INIT_LIST_HEAD(&ev->node);
+ ev->disk = disk;
+ spin_lock_init(&ev->lock);
+ mutex_init(&ev->block_mutex);
+ ev->block = 1;
+ ev->poll_msecs = -1;
+ INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
+
+ disk->ev = ev;
+}
+
+static void disk_add_events(struct gendisk *disk)
+{
+ if (!disk->ev)
+ return;
+
+ /* FIXME: error handling */
+ if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
+ pr_warn("%s: failed to create sysfs files for events\n",
+ disk->disk_name);
+
+ mutex_lock(&disk_events_mutex);
+ list_add_tail(&disk->ev->node, &disk_events);
+ mutex_unlock(&disk_events_mutex);
+
+ /*
+ * Block count is initialized to 1 and the following initial
+ * unblock kicks it into action.
+ */
+ __disk_unblock_events(disk, true);
+}
+
+static void disk_del_events(struct gendisk *disk)
+{
+ if (!disk->ev)
+ return;
+
+ disk_block_events(disk);
+
+ mutex_lock(&disk_events_mutex);
+ list_del_init(&disk->ev->node);
+ mutex_unlock(&disk_events_mutex);
+
+ sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
+}
+
+static void disk_release_events(struct gendisk *disk)
+{
+ /* the block count should be 1 from disk_del_events() */
+ WARN_ON_ONCE(disk->ev && disk->ev->block != 1);
+ kfree(disk->ev);
+}
diff --git a/src/kernel/linux/v4.14/block/ioctl.c b/src/kernel/linux/v4.14/block/ioctl.c
new file mode 100644
index 0000000..0de02ee
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/ioctl.c
@@ -0,0 +1,597 @@
+#include <linux/capability.h>
+#include <linux/blkdev.h>
+#include <linux/export.h>
+#include <linux/gfp.h>
+#include <linux/blkpg.h>
+#include <linux/hdreg.h>
+#include <linux/backing-dev.h>
+#include <linux/fs.h>
+#include <linux/blktrace_api.h>
+#include <linux/pr.h>
+#include <linux/uaccess.h>
+
+static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
+{
+ struct block_device *bdevp;
+ struct gendisk *disk;
+ struct hd_struct *part, *lpart;
+ struct blkpg_ioctl_arg a;
+ struct blkpg_partition p;
+ struct disk_part_iter piter;
+ long long start, length;
+ int partno;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
+ return -EFAULT;
+ if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
+ return -EFAULT;
+ disk = bdev->bd_disk;
+ if (bdev != bdev->bd_contains)
+ return -EINVAL;
+ partno = p.pno;
+ if (partno <= 0)
+ return -EINVAL;
+ switch (a.op) {
+ case BLKPG_ADD_PARTITION:
+ start = p.start >> 9;
+ length = p.length >> 9;
+ /* check for fit in a hd_struct */
+ if (sizeof(sector_t) == sizeof(long) &&
+ sizeof(long long) > sizeof(long)) {
+ long pstart = start, plength = length;
+ if (pstart != start || plength != length
+ || pstart < 0 || plength < 0 || partno > 65535)
+ return -EINVAL;
+ }
+ /* check if partition is aligned to blocksize */
+ if (p.start & (bdev_logical_block_size(bdev) - 1))
+ return -EINVAL;
+
+ mutex_lock(&bdev->bd_mutex);
+
+ /* overlap? */
+ disk_part_iter_init(&piter, disk,
+ DISK_PITER_INCL_EMPTY);
+ while ((part = disk_part_iter_next(&piter))) {
+ if (!(start + length <= part->start_sect ||
+ start >= part->start_sect + part->nr_sects)) {
+ disk_part_iter_exit(&piter);
+ mutex_unlock(&bdev->bd_mutex);
+ return -EBUSY;
+ }
+ }
+ disk_part_iter_exit(&piter);
+
+ /* all seems OK */
+ part = add_partition(disk, partno, start, length,
+ ADDPART_FLAG_NONE, NULL);
+ mutex_unlock(&bdev->bd_mutex);
+ return PTR_ERR_OR_ZERO(part);
+ case BLKPG_DEL_PARTITION:
+ part = disk_get_part(disk, partno);
+ if (!part)
+ return -ENXIO;
+
+ bdevp = bdget(part_devt(part));
+ disk_put_part(part);
+ if (!bdevp)
+ return -ENOMEM;
+
+ mutex_lock(&bdevp->bd_mutex);
+ if (bdevp->bd_openers) {
+ mutex_unlock(&bdevp->bd_mutex);
+ bdput(bdevp);
+ return -EBUSY;
+ }
+ /* all seems OK */
+ fsync_bdev(bdevp);
+ invalidate_bdev(bdevp);
+
+ mutex_lock_nested(&bdev->bd_mutex, 1);
+ delete_partition(disk, partno);
+ mutex_unlock(&bdev->bd_mutex);
+ mutex_unlock(&bdevp->bd_mutex);
+ bdput(bdevp);
+
+ return 0;
+ case BLKPG_RESIZE_PARTITION:
+ start = p.start >> 9;
+ /* new length of partition in bytes */
+ length = p.length >> 9;
+ /* check for fit in a hd_struct */
+ if (sizeof(sector_t) == sizeof(long) &&
+ sizeof(long long) > sizeof(long)) {
+ long pstart = start, plength = length;
+ if (pstart != start || plength != length
+ || pstart < 0 || plength < 0)
+ return -EINVAL;
+ }
+ part = disk_get_part(disk, partno);
+ if (!part)
+ return -ENXIO;
+ bdevp = bdget(part_devt(part));
+ if (!bdevp) {
+ disk_put_part(part);
+ return -ENOMEM;
+ }
+ mutex_lock(&bdevp->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, 1);
+ if (start != part->start_sect) {
+ mutex_unlock(&bdevp->bd_mutex);
+ mutex_unlock(&bdev->bd_mutex);
+ bdput(bdevp);
+ disk_put_part(part);
+ return -EINVAL;
+ }
+ /* overlap? */
+ disk_part_iter_init(&piter, disk,
+ DISK_PITER_INCL_EMPTY);
+ while ((lpart = disk_part_iter_next(&piter))) {
+ if (lpart->partno != partno &&
+ !(start + length <= lpart->start_sect ||
+ start >= lpart->start_sect + lpart->nr_sects)
+ ) {
+ disk_part_iter_exit(&piter);
+ mutex_unlock(&bdevp->bd_mutex);
+ mutex_unlock(&bdev->bd_mutex);
+ bdput(bdevp);
+ disk_put_part(part);
+ return -EBUSY;
+ }
+ }
+ disk_part_iter_exit(&piter);
+ part_nr_sects_write(part, (sector_t)length);
+ i_size_write(bdevp->bd_inode, p.length);
+ mutex_unlock(&bdevp->bd_mutex);
+ mutex_unlock(&bdev->bd_mutex);
+ bdput(bdevp);
+ disk_put_part(part);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+/*
+ * This is an exported API for the block driver, and will not
+ * acquire bd_mutex. This API should be used in case that
+ * caller has held bd_mutex already.
+ */
+int __blkdev_reread_part(struct block_device *bdev)
+{
+ struct gendisk *disk = bdev->bd_disk;
+
+ if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
+ return -EINVAL;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ lockdep_assert_held(&bdev->bd_mutex);
+
+ return rescan_partitions(disk, bdev);
+}
+EXPORT_SYMBOL(__blkdev_reread_part);
+
+/*
+ * This is an exported API for the block driver, and will
+ * try to acquire bd_mutex. If bd_mutex has been held already
+ * in current context, please call __blkdev_reread_part().
+ *
+ * Make sure the held locks in current context aren't required
+ * in open()/close() handler and I/O path for avoiding ABBA deadlock:
+ * - bd_mutex is held before calling block driver's open/close
+ * handler
+ * - reading partition table may submit I/O to the block device
+ */
+int blkdev_reread_part(struct block_device *bdev)
+{
+ int res;
+
+ mutex_lock(&bdev->bd_mutex);
+ res = __blkdev_reread_part(bdev);
+ mutex_unlock(&bdev->bd_mutex);
+
+ return res;
+}
+EXPORT_SYMBOL(blkdev_reread_part);
+
+static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
+ unsigned long arg, unsigned long flags)
+{
+ uint64_t range[2];
+ uint64_t start, len;
+
+ if (!(mode & FMODE_WRITE))
+ return -EBADF;
+
+ if (copy_from_user(range, (void __user *)arg, sizeof(range)))
+ return -EFAULT;
+
+ start = range[0];
+ len = range[1];
+
+ if (start & 511)
+ return -EINVAL;
+ if (len & 511)
+ return -EINVAL;
+ start >>= 9;
+ len >>= 9;
+
+ if (start + len > (i_size_read(bdev->bd_inode) >> 9))
+ return -EINVAL;
+ return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
+}
+
+static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
+ unsigned long arg)
+{
+ uint64_t range[2];
+ struct address_space *mapping;
+ uint64_t start, end, len;
+
+ if (!(mode & FMODE_WRITE))
+ return -EBADF;
+
+ if (copy_from_user(range, (void __user *)arg, sizeof(range)))
+ return -EFAULT;
+
+ start = range[0];
+ len = range[1];
+ end = start + len - 1;
+
+ if (start & 511)
+ return -EINVAL;
+ if (len & 511)
+ return -EINVAL;
+ if (end >= (uint64_t)i_size_read(bdev->bd_inode))
+ return -EINVAL;
+ if (end < start)
+ return -EINVAL;
+
+ /* Invalidate the page cache, including dirty pages */
+ mapping = bdev->bd_inode->i_mapping;
+ truncate_inode_pages_range(mapping, start, end);
+
+ return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
+ BLKDEV_ZERO_NOUNMAP);
+}
+
+static int put_ushort(unsigned long arg, unsigned short val)
+{
+ return put_user(val, (unsigned short __user *)arg);
+}
+
+static int put_int(unsigned long arg, int val)
+{
+ return put_user(val, (int __user *)arg);
+}
+
+static int put_uint(unsigned long arg, unsigned int val)
+{
+ return put_user(val, (unsigned int __user *)arg);
+}
+
+static int put_long(unsigned long arg, long val)
+{
+ return put_user(val, (long __user *)arg);
+}
+
+static int put_ulong(unsigned long arg, unsigned long val)
+{
+ return put_user(val, (unsigned long __user *)arg);
+}
+
+static int put_u64(unsigned long arg, u64 val)
+{
+ return put_user(val, (u64 __user *)arg);
+}
+
+int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
+ unsigned cmd, unsigned long arg)
+{
+ struct gendisk *disk = bdev->bd_disk;
+
+ if (disk->fops->ioctl)
+ return disk->fops->ioctl(bdev, mode, cmd, arg);
+
+ return -ENOTTY;
+}
+/*
+ * For the record: _GPL here is only because somebody decided to slap it
+ * on the previous export. Sheer idiocy, since it wasn't copyrightable
+ * at all and could be open-coded without any exports by anybody who cares.
+ */
+EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
+
+static int blkdev_pr_register(struct block_device *bdev,
+ struct pr_registration __user *arg)
+{
+ const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
+ struct pr_registration reg;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (!ops || !ops->pr_register)
+ return -EOPNOTSUPP;
+ if (copy_from_user(®, arg, sizeof(reg)))
+ return -EFAULT;
+
+ if (reg.flags & ~PR_FL_IGNORE_KEY)
+ return -EOPNOTSUPP;
+ return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
+}
+
+static int blkdev_pr_reserve(struct block_device *bdev,
+ struct pr_reservation __user *arg)
+{
+ const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
+ struct pr_reservation rsv;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (!ops || !ops->pr_reserve)
+ return -EOPNOTSUPP;
+ if (copy_from_user(&rsv, arg, sizeof(rsv)))
+ return -EFAULT;
+
+ if (rsv.flags & ~PR_FL_IGNORE_KEY)
+ return -EOPNOTSUPP;
+ return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
+}
+
+static int blkdev_pr_release(struct block_device *bdev,
+ struct pr_reservation __user *arg)
+{
+ const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
+ struct pr_reservation rsv;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (!ops || !ops->pr_release)
+ return -EOPNOTSUPP;
+ if (copy_from_user(&rsv, arg, sizeof(rsv)))
+ return -EFAULT;
+
+ if (rsv.flags)
+ return -EOPNOTSUPP;
+ return ops->pr_release(bdev, rsv.key, rsv.type);
+}
+
+static int blkdev_pr_preempt(struct block_device *bdev,
+ struct pr_preempt __user *arg, bool abort)
+{
+ const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
+ struct pr_preempt p;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (!ops || !ops->pr_preempt)
+ return -EOPNOTSUPP;
+ if (copy_from_user(&p, arg, sizeof(p)))
+ return -EFAULT;
+
+ if (p.flags)
+ return -EOPNOTSUPP;
+ return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
+}
+
+static int blkdev_pr_clear(struct block_device *bdev,
+ struct pr_clear __user *arg)
+{
+ const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
+ struct pr_clear c;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (!ops || !ops->pr_clear)
+ return -EOPNOTSUPP;
+ if (copy_from_user(&c, arg, sizeof(c)))
+ return -EFAULT;
+
+ if (c.flags)
+ return -EOPNOTSUPP;
+ return ops->pr_clear(bdev, c.key);
+}
+
+/*
+ * Is it an unrecognized ioctl? The correct returns are either
+ * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
+ * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
+ * code before returning.
+ *
+ * Confused drivers sometimes return EINVAL, which is wrong. It
+ * means "I understood the ioctl command, but the parameters to
+ * it were wrong".
+ *
+ * We should aim to just fix the broken drivers, the EINVAL case
+ * should go away.
+ */
+static inline int is_unrecognized_ioctl(int ret)
+{
+ return ret == -EINVAL ||
+ ret == -ENOTTY ||
+ ret == -ENOIOCTLCMD;
+}
+
+static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
+ unsigned cmd, unsigned long arg)
+{
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+ if (!is_unrecognized_ioctl(ret))
+ return ret;
+
+ fsync_bdev(bdev);
+ invalidate_bdev(bdev);
+ return 0;
+}
+
+static int blkdev_roset(struct block_device *bdev, fmode_t mode,
+ unsigned cmd, unsigned long arg)
+{
+ int ret, n;
+
+ ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+ if (!is_unrecognized_ioctl(ret))
+ return ret;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ if (get_user(n, (int __user *)arg))
+ return -EFAULT;
+ set_device_ro(bdev, n);
+ return 0;
+}
+
+static int blkdev_getgeo(struct block_device *bdev,
+ struct hd_geometry __user *argp)
+{
+ struct gendisk *disk = bdev->bd_disk;
+ struct hd_geometry geo;
+ int ret;
+
+ if (!argp)
+ return -EINVAL;
+ if (!disk->fops->getgeo)
+ return -ENOTTY;
+
+ /*
+ * We need to set the startsect first, the driver may
+ * want to override it.
+ */
+ memset(&geo, 0, sizeof(geo));
+ geo.start = get_start_sect(bdev);
+ ret = disk->fops->getgeo(bdev, &geo);
+ if (ret)
+ return ret;
+ if (copy_to_user(argp, &geo, sizeof(geo)))
+ return -EFAULT;
+ return 0;
+}
+
+/* set the logical block size */
+static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
+ int __user *argp)
+{
+ int ret, n;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ if (!argp)
+ return -EINVAL;
+ if (get_user(n, argp))
+ return -EFAULT;
+
+ if (!(mode & FMODE_EXCL)) {
+ bdgrab(bdev);
+ if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
+ return -EBUSY;
+ }
+
+ ret = set_blocksize(bdev, n);
+ if (!(mode & FMODE_EXCL))
+ blkdev_put(bdev, mode | FMODE_EXCL);
+ return ret;
+}
+
+/*
+ * always keep this in sync with compat_blkdev_ioctl()
+ */
+int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
+ unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ loff_t size;
+ unsigned int max_sectors;
+
+ switch (cmd) {
+ case BLKFLSBUF:
+ return blkdev_flushbuf(bdev, mode, cmd, arg);
+ case BLKROSET:
+ return blkdev_roset(bdev, mode, cmd, arg);
+ case BLKDISCARD:
+ return blk_ioctl_discard(bdev, mode, arg, 0);
+ case BLKSECDISCARD:
+ return blk_ioctl_discard(bdev, mode, arg,
+ BLKDEV_DISCARD_SECURE);
+ case BLKZEROOUT:
+ return blk_ioctl_zeroout(bdev, mode, arg);
+ case BLKREPORTZONE:
+ return blkdev_report_zones_ioctl(bdev, mode, cmd, arg);
+ case BLKRESETZONE:
+ return blkdev_reset_zones_ioctl(bdev, mode, cmd, arg);
+ case HDIO_GETGEO:
+ return blkdev_getgeo(bdev, argp);
+ case BLKRAGET:
+ case BLKFRAGET:
+ if (!arg)
+ return -EINVAL;
+ return put_long(arg, (bdev->bd_bdi->ra_pages*PAGE_SIZE) / 512);
+ case BLKROGET:
+ return put_int(arg, bdev_read_only(bdev) != 0);
+ case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
+ return put_int(arg, block_size(bdev));
+ case BLKSSZGET: /* get block device logical block size */
+ return put_int(arg, bdev_logical_block_size(bdev));
+ case BLKPBSZGET: /* get block device physical block size */
+ return put_uint(arg, bdev_physical_block_size(bdev));
+ case BLKIOMIN:
+ return put_uint(arg, bdev_io_min(bdev));
+ case BLKIOOPT:
+ return put_uint(arg, bdev_io_opt(bdev));
+ case BLKALIGNOFF:
+ return put_int(arg, bdev_alignment_offset(bdev));
+ case BLKDISCARDZEROES:
+ return put_uint(arg, 0);
+ case BLKSECTGET:
+ max_sectors = min_t(unsigned int, USHRT_MAX,
+ queue_max_sectors(bdev_get_queue(bdev)));
+ return put_ushort(arg, max_sectors);
+ case BLKROTATIONAL:
+ return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
+ case BLKRASET:
+ case BLKFRASET:
+ if(!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
+ return 0;
+ case BLKBSZSET:
+ return blkdev_bszset(bdev, mode, argp);
+ case BLKPG:
+ return blkpg_ioctl(bdev, argp);
+ case BLKRRPART:
+ return blkdev_reread_part(bdev);
+ case BLKGETSIZE:
+ size = i_size_read(bdev->bd_inode);
+ if ((size >> 9) > ~0UL)
+ return -EFBIG;
+ return put_ulong(arg, size >> 9);
+ case BLKGETSIZE64:
+ return put_u64(arg, i_size_read(bdev->bd_inode));
+ case BLKTRACESTART:
+ case BLKTRACESTOP:
+ case BLKTRACESETUP:
+ case BLKTRACETEARDOWN:
+ return blk_trace_ioctl(bdev, cmd, argp);
+ case IOC_PR_REGISTER:
+ return blkdev_pr_register(bdev, argp);
+ case IOC_PR_RESERVE:
+ return blkdev_pr_reserve(bdev, argp);
+ case IOC_PR_RELEASE:
+ return blkdev_pr_release(bdev, argp);
+ case IOC_PR_PREEMPT:
+ return blkdev_pr_preempt(bdev, argp, false);
+ case IOC_PR_PREEMPT_ABORT:
+ return blkdev_pr_preempt(bdev, argp, true);
+ case IOC_PR_CLEAR:
+ return blkdev_pr_clear(bdev, argp);
+ default:
+ return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+ }
+}
+EXPORT_SYMBOL_GPL(blkdev_ioctl);
diff --git a/src/kernel/linux/v4.14/block/ioprio.c b/src/kernel/linux/v4.14/block/ioprio.c
new file mode 100644
index 0000000..6f5d0b6
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/ioprio.c
@@ -0,0 +1,241 @@
+/*
+ * fs/ioprio.c
+ *
+ * Copyright (C) 2004 Jens Axboe <axboe@kernel.dk>
+ *
+ * Helper functions for setting/querying io priorities of processes. The
+ * system calls closely mimmick getpriority/setpriority, see the man page for
+ * those. The prio argument is a composite of prio class and prio data, where
+ * the data argument has meaning within that class. The standard scheduling
+ * classes have 8 distinct prio levels, with 0 being the highest prio and 7
+ * being the lowest.
+ *
+ * IOW, setting BE scheduling class with prio 2 is done ala:
+ *
+ * unsigned int prio = (IOPRIO_CLASS_BE << IOPRIO_CLASS_SHIFT) | 2;
+ *
+ * ioprio_set(PRIO_PROCESS, pid, prio);
+ *
+ * See also Documentation/block/ioprio.txt
+ *
+ */
+#include <linux/gfp.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/ioprio.h>
+#include <linux/cred.h>
+#include <linux/blkdev.h>
+#include <linux/capability.h>
+#include <linux/sched/user.h>
+#include <linux/sched/task.h>
+#include <linux/syscalls.h>
+#include <linux/security.h>
+#include <linux/pid_namespace.h>
+
+int set_task_ioprio(struct task_struct *task, int ioprio)
+{
+ int err;
+ struct io_context *ioc;
+ const struct cred *cred = current_cred(), *tcred;
+
+ rcu_read_lock();
+ tcred = __task_cred(task);
+ if (!uid_eq(tcred->uid, cred->euid) &&
+ !uid_eq(tcred->uid, cred->uid) && !capable(CAP_SYS_NICE)) {
+ rcu_read_unlock();
+ return -EPERM;
+ }
+ rcu_read_unlock();
+
+ err = security_task_setioprio(task, ioprio);
+ if (err)
+ return err;
+
+ ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE);
+ if (ioc) {
+ ioc->ioprio = ioprio;
+ put_io_context(ioc);
+ }
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(set_task_ioprio);
+
+SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
+{
+ int class = IOPRIO_PRIO_CLASS(ioprio);
+ int data = IOPRIO_PRIO_DATA(ioprio);
+ struct task_struct *p, *g;
+ struct user_struct *user;
+ struct pid *pgrp;
+ kuid_t uid;
+ int ret;
+
+ switch (class) {
+ case IOPRIO_CLASS_RT:
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ /* fall through */
+ /* rt has prio field too */
+ case IOPRIO_CLASS_BE:
+ if (data >= IOPRIO_BE_NR || data < 0)
+ return -EINVAL;
+
+ break;
+ case IOPRIO_CLASS_IDLE:
+ break;
+ case IOPRIO_CLASS_NONE:
+ if (data)
+ return -EINVAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = -ESRCH;
+ rcu_read_lock();
+ switch (which) {
+ case IOPRIO_WHO_PROCESS:
+ if (!who)
+ p = current;
+ else
+ p = find_task_by_vpid(who);
+ if (p)
+ ret = set_task_ioprio(p, ioprio);
+ break;
+ case IOPRIO_WHO_PGRP:
+ if (!who)
+ pgrp = task_pgrp(current);
+ else
+ pgrp = find_vpid(who);
+ do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
+ ret = set_task_ioprio(p, ioprio);
+ if (ret)
+ break;
+ } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
+ break;
+ case IOPRIO_WHO_USER:
+ uid = make_kuid(current_user_ns(), who);
+ if (!uid_valid(uid))
+ break;
+ if (!who)
+ user = current_user();
+ else
+ user = find_user(uid);
+
+ if (!user)
+ break;
+
+ for_each_process_thread(g, p) {
+ if (!uid_eq(task_uid(p), uid) ||
+ !task_pid_vnr(p))
+ continue;
+ ret = set_task_ioprio(p, ioprio);
+ if (ret)
+ goto free_uid;
+ }
+free_uid:
+ if (who)
+ free_uid(user);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ rcu_read_unlock();
+ return ret;
+}
+
+static int get_task_ioprio(struct task_struct *p)
+{
+ int ret;
+
+ ret = security_task_getioprio(p);
+ if (ret)
+ goto out;
+ ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM);
+ task_lock(p);
+ if (p->io_context)
+ ret = p->io_context->ioprio;
+ task_unlock(p);
+out:
+ return ret;
+}
+
+int ioprio_best(unsigned short aprio, unsigned short bprio)
+{
+ if (!ioprio_valid(aprio))
+ aprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM);
+ if (!ioprio_valid(bprio))
+ bprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM);
+
+ return min(aprio, bprio);
+}
+
+SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
+{
+ struct task_struct *g, *p;
+ struct user_struct *user;
+ struct pid *pgrp;
+ kuid_t uid;
+ int ret = -ESRCH;
+ int tmpio;
+
+ rcu_read_lock();
+ switch (which) {
+ case IOPRIO_WHO_PROCESS:
+ if (!who)
+ p = current;
+ else
+ p = find_task_by_vpid(who);
+ if (p)
+ ret = get_task_ioprio(p);
+ break;
+ case IOPRIO_WHO_PGRP:
+ if (!who)
+ pgrp = task_pgrp(current);
+ else
+ pgrp = find_vpid(who);
+ do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
+ tmpio = get_task_ioprio(p);
+ if (tmpio < 0)
+ continue;
+ if (ret == -ESRCH)
+ ret = tmpio;
+ else
+ ret = ioprio_best(ret, tmpio);
+ } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
+ break;
+ case IOPRIO_WHO_USER:
+ uid = make_kuid(current_user_ns(), who);
+ if (!who)
+ user = current_user();
+ else
+ user = find_user(uid);
+
+ if (!user)
+ break;
+
+ for_each_process_thread(g, p) {
+ if (!uid_eq(task_uid(p), user->uid) ||
+ !task_pid_vnr(p))
+ continue;
+ tmpio = get_task_ioprio(p);
+ if (tmpio < 0)
+ continue;
+ if (ret == -ESRCH)
+ ret = tmpio;
+ else
+ ret = ioprio_best(ret, tmpio);
+ }
+
+ if (who)
+ free_uid(user);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ rcu_read_unlock();
+ return ret;
+}
diff --git a/src/kernel/linux/v4.14/block/kyber-iosched.c b/src/kernel/linux/v4.14/block/kyber-iosched.c
new file mode 100644
index 0000000..09cd5cf
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/kyber-iosched.c
@@ -0,0 +1,847 @@
+/*
+ * The Kyber I/O scheduler. Controls latency by throttling queue depths using
+ * scalable techniques.
+ *
+ * Copyright (C) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/elevator.h>
+#include <linux/module.h>
+#include <linux/sbitmap.h>
+
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-debugfs.h"
+#include "blk-mq-sched.h"
+#include "blk-mq-tag.h"
+#include "blk-stat.h"
+
+/* Scheduling domains. */
+enum {
+ KYBER_READ,
+ KYBER_SYNC_WRITE,
+ KYBER_OTHER, /* Async writes, discard, etc. */
+ KYBER_NUM_DOMAINS,
+};
+
+enum {
+ KYBER_MIN_DEPTH = 256,
+
+ /*
+ * In order to prevent starvation of synchronous requests by a flood of
+ * asynchronous requests, we reserve 25% of requests for synchronous
+ * operations.
+ */
+ KYBER_ASYNC_PERCENT = 75,
+};
+
+/*
+ * Initial device-wide depths for each scheduling domain.
+ *
+ * Even for fast devices with lots of tags like NVMe, you can saturate
+ * the device with only a fraction of the maximum possible queue depth.
+ * So, we cap these to a reasonable value.
+ */
+static const unsigned int kyber_depth[] = {
+ [KYBER_READ] = 256,
+ [KYBER_SYNC_WRITE] = 128,
+ [KYBER_OTHER] = 64,
+};
+
+/*
+ * Scheduling domain batch sizes. We favor reads.
+ */
+static const unsigned int kyber_batch_size[] = {
+ [KYBER_READ] = 16,
+ [KYBER_SYNC_WRITE] = 8,
+ [KYBER_OTHER] = 8,
+};
+
+struct kyber_queue_data {
+ struct request_queue *q;
+
+ struct blk_stat_callback *cb;
+
+ /*
+ * The device is divided into multiple scheduling domains based on the
+ * request type. Each domain has a fixed number of in-flight requests of
+ * that type device-wide, limited by these tokens.
+ */
+ struct sbitmap_queue domain_tokens[KYBER_NUM_DOMAINS];
+
+ /*
+ * Async request percentage, converted to per-word depth for
+ * sbitmap_get_shallow().
+ */
+ unsigned int async_depth;
+
+ /* Target latencies in nanoseconds. */
+ u64 read_lat_nsec, write_lat_nsec;
+};
+
+struct kyber_hctx_data {
+ spinlock_t lock;
+ struct list_head rqs[KYBER_NUM_DOMAINS];
+ unsigned int cur_domain;
+ unsigned int batching;
+ wait_queue_entry_t domain_wait[KYBER_NUM_DOMAINS];
+ atomic_t wait_index[KYBER_NUM_DOMAINS];
+};
+
+static int rq_sched_domain(const struct request *rq)
+{
+ unsigned int op = rq->cmd_flags;
+
+ if ((op & REQ_OP_MASK) == REQ_OP_READ)
+ return KYBER_READ;
+ else if ((op & REQ_OP_MASK) == REQ_OP_WRITE && op_is_sync(op))
+ return KYBER_SYNC_WRITE;
+ else
+ return KYBER_OTHER;
+}
+
+enum {
+ NONE = 0,
+ GOOD = 1,
+ GREAT = 2,
+ BAD = -1,
+ AWFUL = -2,
+};
+
+#define IS_GOOD(status) ((status) > 0)
+#define IS_BAD(status) ((status) < 0)
+
+static int kyber_lat_status(struct blk_stat_callback *cb,
+ unsigned int sched_domain, u64 target)
+{
+ u64 latency;
+
+ if (!cb->stat[sched_domain].nr_samples)
+ return NONE;
+
+ latency = cb->stat[sched_domain].mean;
+ if (latency >= 2 * target)
+ return AWFUL;
+ else if (latency > target)
+ return BAD;
+ else if (latency <= target / 2)
+ return GREAT;
+ else /* (latency <= target) */
+ return GOOD;
+}
+
+/*
+ * Adjust the read or synchronous write depth given the status of reads and
+ * writes. The goal is that the latencies of the two domains are fair (i.e., if
+ * one is good, then the other is good).
+ */
+static void kyber_adjust_rw_depth(struct kyber_queue_data *kqd,
+ unsigned int sched_domain, int this_status,
+ int other_status)
+{
+ unsigned int orig_depth, depth;
+
+ /*
+ * If this domain had no samples, or reads and writes are both good or
+ * both bad, don't adjust the depth.
+ */
+ if (this_status == NONE ||
+ (IS_GOOD(this_status) && IS_GOOD(other_status)) ||
+ (IS_BAD(this_status) && IS_BAD(other_status)))
+ return;
+
+ orig_depth = depth = kqd->domain_tokens[sched_domain].sb.depth;
+
+ if (other_status == NONE) {
+ depth++;
+ } else {
+ switch (this_status) {
+ case GOOD:
+ if (other_status == AWFUL)
+ depth -= max(depth / 4, 1U);
+ else
+ depth -= max(depth / 8, 1U);
+ break;
+ case GREAT:
+ if (other_status == AWFUL)
+ depth /= 2;
+ else
+ depth -= max(depth / 4, 1U);
+ break;
+ case BAD:
+ depth++;
+ break;
+ case AWFUL:
+ if (other_status == GREAT)
+ depth += 2;
+ else
+ depth++;
+ break;
+ }
+ }
+
+ depth = clamp(depth, 1U, kyber_depth[sched_domain]);
+ if (depth != orig_depth)
+ sbitmap_queue_resize(&kqd->domain_tokens[sched_domain], depth);
+}
+
+/*
+ * Adjust the depth of other requests given the status of reads and synchronous
+ * writes. As long as either domain is doing fine, we don't throttle, but if
+ * both domains are doing badly, we throttle heavily.
+ */
+static void kyber_adjust_other_depth(struct kyber_queue_data *kqd,
+ int read_status, int write_status,
+ bool have_samples)
+{
+ unsigned int orig_depth, depth;
+ int status;
+
+ orig_depth = depth = kqd->domain_tokens[KYBER_OTHER].sb.depth;
+
+ if (read_status == NONE && write_status == NONE) {
+ depth += 2;
+ } else if (have_samples) {
+ if (read_status == NONE)
+ status = write_status;
+ else if (write_status == NONE)
+ status = read_status;
+ else
+ status = max(read_status, write_status);
+ switch (status) {
+ case GREAT:
+ depth += 2;
+ break;
+ case GOOD:
+ depth++;
+ break;
+ case BAD:
+ depth -= max(depth / 4, 1U);
+ break;
+ case AWFUL:
+ depth /= 2;
+ break;
+ }
+ }
+
+ depth = clamp(depth, 1U, kyber_depth[KYBER_OTHER]);
+ if (depth != orig_depth)
+ sbitmap_queue_resize(&kqd->domain_tokens[KYBER_OTHER], depth);
+}
+
+/*
+ * Apply heuristics for limiting queue depths based on gathered latency
+ * statistics.
+ */
+static void kyber_stat_timer_fn(struct blk_stat_callback *cb)
+{
+ struct kyber_queue_data *kqd = cb->data;
+ int read_status, write_status;
+
+ read_status = kyber_lat_status(cb, KYBER_READ, kqd->read_lat_nsec);
+ write_status = kyber_lat_status(cb, KYBER_SYNC_WRITE, kqd->write_lat_nsec);
+
+ kyber_adjust_rw_depth(kqd, KYBER_READ, read_status, write_status);
+ kyber_adjust_rw_depth(kqd, KYBER_SYNC_WRITE, write_status, read_status);
+ kyber_adjust_other_depth(kqd, read_status, write_status,
+ cb->stat[KYBER_OTHER].nr_samples != 0);
+
+ /*
+ * Continue monitoring latencies if we aren't hitting the targets or
+ * we're still throttling other requests.
+ */
+ if (!blk_stat_is_active(kqd->cb) &&
+ ((IS_BAD(read_status) || IS_BAD(write_status) ||
+ kqd->domain_tokens[KYBER_OTHER].sb.depth < kyber_depth[KYBER_OTHER])))
+ blk_stat_activate_msecs(kqd->cb, 100);
+}
+
+static unsigned int kyber_sched_tags_shift(struct kyber_queue_data *kqd)
+{
+ /*
+ * All of the hardware queues have the same depth, so we can just grab
+ * the shift of the first one.
+ */
+ return kqd->q->queue_hw_ctx[0]->sched_tags->bitmap_tags.sb.shift;
+}
+
+static struct kyber_queue_data *kyber_queue_data_alloc(struct request_queue *q)
+{
+ struct kyber_queue_data *kqd;
+ unsigned int max_tokens;
+ unsigned int shift;
+ int ret = -ENOMEM;
+ int i;
+
+ kqd = kmalloc_node(sizeof(*kqd), GFP_KERNEL, q->node);
+ if (!kqd)
+ goto err;
+ kqd->q = q;
+
+ kqd->cb = blk_stat_alloc_callback(kyber_stat_timer_fn, rq_sched_domain,
+ KYBER_NUM_DOMAINS, kqd);
+ if (!kqd->cb)
+ goto err_kqd;
+
+ /*
+ * The maximum number of tokens for any scheduling domain is at least
+ * the queue depth of a single hardware queue. If the hardware doesn't
+ * have many tags, still provide a reasonable number.
+ */
+ max_tokens = max_t(unsigned int, q->tag_set->queue_depth,
+ KYBER_MIN_DEPTH);
+ for (i = 0; i < KYBER_NUM_DOMAINS; i++) {
+ WARN_ON(!kyber_depth[i]);
+ WARN_ON(!kyber_batch_size[i]);
+ ret = sbitmap_queue_init_node(&kqd->domain_tokens[i],
+ max_tokens, -1, false, GFP_KERNEL,
+ q->node);
+ if (ret) {
+ while (--i >= 0)
+ sbitmap_queue_free(&kqd->domain_tokens[i]);
+ goto err_cb;
+ }
+ sbitmap_queue_resize(&kqd->domain_tokens[i], kyber_depth[i]);
+ }
+
+ shift = kyber_sched_tags_shift(kqd);
+ kqd->async_depth = (1U << shift) * KYBER_ASYNC_PERCENT / 100U;
+
+ kqd->read_lat_nsec = 2000000ULL;
+ kqd->write_lat_nsec = 10000000ULL;
+
+ return kqd;
+
+err_cb:
+ blk_stat_free_callback(kqd->cb);
+err_kqd:
+ kfree(kqd);
+err:
+ return ERR_PTR(ret);
+}
+
+static int kyber_init_sched(struct request_queue *q, struct elevator_type *e)
+{
+ struct kyber_queue_data *kqd;
+ struct elevator_queue *eq;
+
+ eq = elevator_alloc(q, e);
+ if (!eq)
+ return -ENOMEM;
+
+ kqd = kyber_queue_data_alloc(q);
+ if (IS_ERR(kqd)) {
+ kobject_put(&eq->kobj);
+ return PTR_ERR(kqd);
+ }
+
+ eq->elevator_data = kqd;
+ q->elevator = eq;
+
+ blk_stat_add_callback(q, kqd->cb);
+
+ return 0;
+}
+
+static void kyber_exit_sched(struct elevator_queue *e)
+{
+ struct kyber_queue_data *kqd = e->elevator_data;
+ struct request_queue *q = kqd->q;
+ int i;
+
+ blk_stat_remove_callback(q, kqd->cb);
+
+ for (i = 0; i < KYBER_NUM_DOMAINS; i++)
+ sbitmap_queue_free(&kqd->domain_tokens[i]);
+ blk_stat_free_callback(kqd->cb);
+ kfree(kqd);
+}
+
+static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
+{
+ struct kyber_hctx_data *khd;
+ int i;
+
+ khd = kmalloc_node(sizeof(*khd), GFP_KERNEL, hctx->numa_node);
+ if (!khd)
+ return -ENOMEM;
+
+ spin_lock_init(&khd->lock);
+
+ for (i = 0; i < KYBER_NUM_DOMAINS; i++) {
+ INIT_LIST_HEAD(&khd->rqs[i]);
+ INIT_LIST_HEAD(&khd->domain_wait[i].entry);
+ atomic_set(&khd->wait_index[i], 0);
+ }
+
+ khd->cur_domain = 0;
+ khd->batching = 0;
+
+ hctx->sched_data = khd;
+
+ return 0;
+}
+
+static void kyber_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
+{
+ kfree(hctx->sched_data);
+}
+
+static int rq_get_domain_token(struct request *rq)
+{
+ return (long)rq->elv.priv[0];
+}
+
+static void rq_set_domain_token(struct request *rq, int token)
+{
+ rq->elv.priv[0] = (void *)(long)token;
+}
+
+static void rq_clear_domain_token(struct kyber_queue_data *kqd,
+ struct request *rq)
+{
+ unsigned int sched_domain;
+ int nr;
+
+ nr = rq_get_domain_token(rq);
+ if (nr != -1) {
+ sched_domain = rq_sched_domain(rq);
+ sbitmap_queue_clear(&kqd->domain_tokens[sched_domain], nr,
+ rq->mq_ctx->cpu);
+ }
+}
+
+static void kyber_limit_depth(unsigned int op, struct blk_mq_alloc_data *data)
+{
+ /*
+ * We use the scheduler tags as per-hardware queue queueing tokens.
+ * Async requests can be limited at this stage.
+ */
+ if (!op_is_sync(op)) {
+ struct kyber_queue_data *kqd = data->q->elevator->elevator_data;
+
+ data->shallow_depth = kqd->async_depth;
+ }
+}
+
+static void kyber_prepare_request(struct request *rq, struct bio *bio)
+{
+ rq_set_domain_token(rq, -1);
+}
+
+static void kyber_finish_request(struct request *rq)
+{
+ struct kyber_queue_data *kqd = rq->q->elevator->elevator_data;
+
+ rq_clear_domain_token(kqd, rq);
+}
+
+static void kyber_completed_request(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+ struct kyber_queue_data *kqd = q->elevator->elevator_data;
+ unsigned int sched_domain;
+ u64 now, latency, target;
+
+ /*
+ * Check if this request met our latency goal. If not, quickly gather
+ * some statistics and start throttling.
+ */
+ sched_domain = rq_sched_domain(rq);
+ switch (sched_domain) {
+ case KYBER_READ:
+ target = kqd->read_lat_nsec;
+ break;
+ case KYBER_SYNC_WRITE:
+ target = kqd->write_lat_nsec;
+ break;
+ default:
+ return;
+ }
+
+ /* If we are already monitoring latencies, don't check again. */
+ if (blk_stat_is_active(kqd->cb))
+ return;
+
+ now = __blk_stat_time(ktime_to_ns(ktime_get()));
+ if (now < blk_stat_time(&rq->issue_stat))
+ return;
+
+ latency = now - blk_stat_time(&rq->issue_stat);
+
+ if (latency > target)
+ blk_stat_activate_msecs(kqd->cb, 10);
+}
+
+static void kyber_flush_busy_ctxs(struct kyber_hctx_data *khd,
+ struct blk_mq_hw_ctx *hctx)
+{
+ LIST_HEAD(rq_list);
+ struct request *rq, *next;
+
+ blk_mq_flush_busy_ctxs(hctx, &rq_list);
+ list_for_each_entry_safe(rq, next, &rq_list, queuelist) {
+ unsigned int sched_domain;
+
+ sched_domain = rq_sched_domain(rq);
+ list_move_tail(&rq->queuelist, &khd->rqs[sched_domain]);
+ }
+}
+
+static int kyber_domain_wake(wait_queue_entry_t *wait, unsigned mode, int flags,
+ void *key)
+{
+ struct blk_mq_hw_ctx *hctx = READ_ONCE(wait->private);
+
+ list_del_init(&wait->entry);
+ blk_mq_run_hw_queue(hctx, true);
+ return 1;
+}
+
+static int kyber_get_domain_token(struct kyber_queue_data *kqd,
+ struct kyber_hctx_data *khd,
+ struct blk_mq_hw_ctx *hctx)
+{
+ unsigned int sched_domain = khd->cur_domain;
+ struct sbitmap_queue *domain_tokens = &kqd->domain_tokens[sched_domain];
+ wait_queue_entry_t *wait = &khd->domain_wait[sched_domain];
+ struct sbq_wait_state *ws;
+ int nr;
+
+ nr = __sbitmap_queue_get(domain_tokens);
+ if (nr >= 0)
+ return nr;
+
+ /*
+ * If we failed to get a domain token, make sure the hardware queue is
+ * run when one becomes available. Note that this is serialized on
+ * khd->lock, but we still need to be careful about the waker.
+ */
+ if (list_empty_careful(&wait->entry)) {
+ init_waitqueue_func_entry(wait, kyber_domain_wake);
+ wait->private = hctx;
+ ws = sbq_wait_ptr(domain_tokens,
+ &khd->wait_index[sched_domain]);
+ add_wait_queue(&ws->wait, wait);
+
+ /*
+ * Try again in case a token was freed before we got on the wait
+ * queue.
+ */
+ nr = __sbitmap_queue_get(domain_tokens);
+ }
+ return nr;
+}
+
+static struct request *
+kyber_dispatch_cur_domain(struct kyber_queue_data *kqd,
+ struct kyber_hctx_data *khd,
+ struct blk_mq_hw_ctx *hctx,
+ bool *flushed)
+{
+ struct list_head *rqs;
+ struct request *rq;
+ int nr;
+
+ rqs = &khd->rqs[khd->cur_domain];
+ rq = list_first_entry_or_null(rqs, struct request, queuelist);
+
+ /*
+ * If there wasn't already a pending request and we haven't flushed the
+ * software queues yet, flush the software queues and check again.
+ */
+ if (!rq && !*flushed) {
+ kyber_flush_busy_ctxs(khd, hctx);
+ *flushed = true;
+ rq = list_first_entry_or_null(rqs, struct request, queuelist);
+ }
+
+ if (rq) {
+ nr = kyber_get_domain_token(kqd, khd, hctx);
+ if (nr >= 0) {
+ khd->batching++;
+ rq_set_domain_token(rq, nr);
+ list_del_init(&rq->queuelist);
+ return rq;
+ }
+ }
+
+ /* There were either no pending requests or no tokens. */
+ return NULL;
+}
+
+static struct request *kyber_dispatch_request(struct blk_mq_hw_ctx *hctx)
+{
+ struct kyber_queue_data *kqd = hctx->queue->elevator->elevator_data;
+ struct kyber_hctx_data *khd = hctx->sched_data;
+ bool flushed = false;
+ struct request *rq;
+ int i;
+
+ spin_lock(&khd->lock);
+
+ /*
+ * First, if we are still entitled to batch, try to dispatch a request
+ * from the batch.
+ */
+ if (khd->batching < kyber_batch_size[khd->cur_domain]) {
+ rq = kyber_dispatch_cur_domain(kqd, khd, hctx, &flushed);
+ if (rq)
+ goto out;
+ }
+
+ /*
+ * Either,
+ * 1. We were no longer entitled to a batch.
+ * 2. The domain we were batching didn't have any requests.
+ * 3. The domain we were batching was out of tokens.
+ *
+ * Start another batch. Note that this wraps back around to the original
+ * domain if no other domains have requests or tokens.
+ */
+ khd->batching = 0;
+ for (i = 0; i < KYBER_NUM_DOMAINS; i++) {
+ if (khd->cur_domain == KYBER_NUM_DOMAINS - 1)
+ khd->cur_domain = 0;
+ else
+ khd->cur_domain++;
+
+ rq = kyber_dispatch_cur_domain(kqd, khd, hctx, &flushed);
+ if (rq)
+ goto out;
+ }
+
+ rq = NULL;
+out:
+ spin_unlock(&khd->lock);
+ return rq;
+}
+
+static bool kyber_has_work(struct blk_mq_hw_ctx *hctx)
+{
+ struct kyber_hctx_data *khd = hctx->sched_data;
+ int i;
+
+ for (i = 0; i < KYBER_NUM_DOMAINS; i++) {
+ if (!list_empty_careful(&khd->rqs[i]))
+ return true;
+ }
+ return false;
+}
+
+#define KYBER_LAT_SHOW_STORE(op) \
+static ssize_t kyber_##op##_lat_show(struct elevator_queue *e, \
+ char *page) \
+{ \
+ struct kyber_queue_data *kqd = e->elevator_data; \
+ \
+ return sprintf(page, "%llu\n", kqd->op##_lat_nsec); \
+} \
+ \
+static ssize_t kyber_##op##_lat_store(struct elevator_queue *e, \
+ const char *page, size_t count) \
+{ \
+ struct kyber_queue_data *kqd = e->elevator_data; \
+ unsigned long long nsec; \
+ int ret; \
+ \
+ ret = kstrtoull(page, 10, &nsec); \
+ if (ret) \
+ return ret; \
+ \
+ kqd->op##_lat_nsec = nsec; \
+ \
+ return count; \
+}
+KYBER_LAT_SHOW_STORE(read);
+KYBER_LAT_SHOW_STORE(write);
+#undef KYBER_LAT_SHOW_STORE
+
+#define KYBER_LAT_ATTR(op) __ATTR(op##_lat_nsec, 0644, kyber_##op##_lat_show, kyber_##op##_lat_store)
+static struct elv_fs_entry kyber_sched_attrs[] = {
+ KYBER_LAT_ATTR(read),
+ KYBER_LAT_ATTR(write),
+ __ATTR_NULL
+};
+#undef KYBER_LAT_ATTR
+
+#ifdef CONFIG_BLK_DEBUG_FS
+#define KYBER_DEBUGFS_DOMAIN_ATTRS(domain, name) \
+static int kyber_##name##_tokens_show(void *data, struct seq_file *m) \
+{ \
+ struct request_queue *q = data; \
+ struct kyber_queue_data *kqd = q->elevator->elevator_data; \
+ \
+ sbitmap_queue_show(&kqd->domain_tokens[domain], m); \
+ return 0; \
+} \
+ \
+static void *kyber_##name##_rqs_start(struct seq_file *m, loff_t *pos) \
+ __acquires(&khd->lock) \
+{ \
+ struct blk_mq_hw_ctx *hctx = m->private; \
+ struct kyber_hctx_data *khd = hctx->sched_data; \
+ \
+ spin_lock(&khd->lock); \
+ return seq_list_start(&khd->rqs[domain], *pos); \
+} \
+ \
+static void *kyber_##name##_rqs_next(struct seq_file *m, void *v, \
+ loff_t *pos) \
+{ \
+ struct blk_mq_hw_ctx *hctx = m->private; \
+ struct kyber_hctx_data *khd = hctx->sched_data; \
+ \
+ return seq_list_next(v, &khd->rqs[domain], pos); \
+} \
+ \
+static void kyber_##name##_rqs_stop(struct seq_file *m, void *v) \
+ __releases(&khd->lock) \
+{ \
+ struct blk_mq_hw_ctx *hctx = m->private; \
+ struct kyber_hctx_data *khd = hctx->sched_data; \
+ \
+ spin_unlock(&khd->lock); \
+} \
+ \
+static const struct seq_operations kyber_##name##_rqs_seq_ops = { \
+ .start = kyber_##name##_rqs_start, \
+ .next = kyber_##name##_rqs_next, \
+ .stop = kyber_##name##_rqs_stop, \
+ .show = blk_mq_debugfs_rq_show, \
+}; \
+ \
+static int kyber_##name##_waiting_show(void *data, struct seq_file *m) \
+{ \
+ struct blk_mq_hw_ctx *hctx = data; \
+ struct kyber_hctx_data *khd = hctx->sched_data; \
+ wait_queue_entry_t *wait = &khd->domain_wait[domain]; \
+ \
+ seq_printf(m, "%d\n", !list_empty_careful(&wait->entry)); \
+ return 0; \
+}
+KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_READ, read)
+KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_SYNC_WRITE, sync_write)
+KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_OTHER, other)
+#undef KYBER_DEBUGFS_DOMAIN_ATTRS
+
+static int kyber_async_depth_show(void *data, struct seq_file *m)
+{
+ struct request_queue *q = data;
+ struct kyber_queue_data *kqd = q->elevator->elevator_data;
+
+ seq_printf(m, "%u\n", kqd->async_depth);
+ return 0;
+}
+
+static int kyber_cur_domain_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ struct kyber_hctx_data *khd = hctx->sched_data;
+
+ switch (khd->cur_domain) {
+ case KYBER_READ:
+ seq_puts(m, "READ\n");
+ break;
+ case KYBER_SYNC_WRITE:
+ seq_puts(m, "SYNC_WRITE\n");
+ break;
+ case KYBER_OTHER:
+ seq_puts(m, "OTHER\n");
+ break;
+ default:
+ seq_printf(m, "%u\n", khd->cur_domain);
+ break;
+ }
+ return 0;
+}
+
+static int kyber_batching_show(void *data, struct seq_file *m)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+ struct kyber_hctx_data *khd = hctx->sched_data;
+
+ seq_printf(m, "%u\n", khd->batching);
+ return 0;
+}
+
+#define KYBER_QUEUE_DOMAIN_ATTRS(name) \
+ {#name "_tokens", 0400, kyber_##name##_tokens_show}
+static const struct blk_mq_debugfs_attr kyber_queue_debugfs_attrs[] = {
+ KYBER_QUEUE_DOMAIN_ATTRS(read),
+ KYBER_QUEUE_DOMAIN_ATTRS(sync_write),
+ KYBER_QUEUE_DOMAIN_ATTRS(other),
+ {"async_depth", 0400, kyber_async_depth_show},
+ {},
+};
+#undef KYBER_QUEUE_DOMAIN_ATTRS
+
+#define KYBER_HCTX_DOMAIN_ATTRS(name) \
+ {#name "_rqs", 0400, .seq_ops = &kyber_##name##_rqs_seq_ops}, \
+ {#name "_waiting", 0400, kyber_##name##_waiting_show}
+static const struct blk_mq_debugfs_attr kyber_hctx_debugfs_attrs[] = {
+ KYBER_HCTX_DOMAIN_ATTRS(read),
+ KYBER_HCTX_DOMAIN_ATTRS(sync_write),
+ KYBER_HCTX_DOMAIN_ATTRS(other),
+ {"cur_domain", 0400, kyber_cur_domain_show},
+ {"batching", 0400, kyber_batching_show},
+ {},
+};
+#undef KYBER_HCTX_DOMAIN_ATTRS
+#endif
+
+static struct elevator_type kyber_sched = {
+ .ops.mq = {
+ .init_sched = kyber_init_sched,
+ .exit_sched = kyber_exit_sched,
+ .init_hctx = kyber_init_hctx,
+ .exit_hctx = kyber_exit_hctx,
+ .limit_depth = kyber_limit_depth,
+ .prepare_request = kyber_prepare_request,
+ .finish_request = kyber_finish_request,
+ .requeue_request = kyber_finish_request,
+ .completed_request = kyber_completed_request,
+ .dispatch_request = kyber_dispatch_request,
+ .has_work = kyber_has_work,
+ },
+ .uses_mq = true,
+#ifdef CONFIG_BLK_DEBUG_FS
+ .queue_debugfs_attrs = kyber_queue_debugfs_attrs,
+ .hctx_debugfs_attrs = kyber_hctx_debugfs_attrs,
+#endif
+ .elevator_attrs = kyber_sched_attrs,
+ .elevator_name = "kyber",
+ .elevator_owner = THIS_MODULE,
+};
+
+static int __init kyber_init(void)
+{
+ return elv_register(&kyber_sched);
+}
+
+static void __exit kyber_exit(void)
+{
+ elv_unregister(&kyber_sched);
+}
+
+module_init(kyber_init);
+module_exit(kyber_exit);
+
+MODULE_AUTHOR("Omar Sandoval");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Kyber I/O scheduler");
diff --git a/src/kernel/linux/v4.14/block/mq-deadline.c b/src/kernel/linux/v4.14/block/mq-deadline.c
new file mode 100644
index 0000000..a1cad43
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/mq-deadline.c
@@ -0,0 +1,679 @@
+/*
+ * MQ Deadline i/o scheduler - adaptation of the legacy deadline scheduler,
+ * for the blk-mq scheduling framework
+ *
+ * Copyright (C) 2016 Jens Axboe <axboe@kernel.dk>
+ */
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/elevator.h>
+#include <linux/bio.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/compiler.h>
+#include <linux/rbtree.h>
+#include <linux/sbitmap.h>
+
+#include "blk.h"
+#include "blk-mq.h"
+#include "blk-mq-debugfs.h"
+#include "blk-mq-tag.h"
+#include "blk-mq-sched.h"
+
+/*
+ * See Documentation/block/deadline-iosched.txt
+ */
+static const int read_expire = HZ / 2; /* max time before a read is submitted. */
+static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
+static const int writes_starved = 2; /* max times reads can starve a write */
+static const int fifo_batch = 16; /* # of sequential requests treated as one
+ by the above parameters. For throughput. */
+
+struct deadline_data {
+ /*
+ * run time data
+ */
+
+ /*
+ * requests (deadline_rq s) are present on both sort_list and fifo_list
+ */
+ struct rb_root sort_list[2];
+ struct list_head fifo_list[2];
+
+ /*
+ * next in sort order. read, write or both are NULL
+ */
+ struct request *next_rq[2];
+ unsigned int batching; /* number of sequential requests made */
+ unsigned int starved; /* times reads have starved writes */
+
+ /*
+ * settings that change how the i/o scheduler behaves
+ */
+ int fifo_expire[2];
+ int fifo_batch;
+ int writes_starved;
+ int front_merges;
+
+ spinlock_t lock;
+ struct list_head dispatch;
+};
+
+static inline struct rb_root *
+deadline_rb_root(struct deadline_data *dd, struct request *rq)
+{
+ return &dd->sort_list[rq_data_dir(rq)];
+}
+
+/*
+ * get the request after `rq' in sector-sorted order
+ */
+static inline struct request *
+deadline_latter_request(struct request *rq)
+{
+ struct rb_node *node = rb_next(&rq->rb_node);
+
+ if (node)
+ return rb_entry_rq(node);
+
+ return NULL;
+}
+
+static void
+deadline_add_rq_rb(struct deadline_data *dd, struct request *rq)
+{
+ struct rb_root *root = deadline_rb_root(dd, rq);
+
+ elv_rb_add(root, rq);
+}
+
+static inline void
+deadline_del_rq_rb(struct deadline_data *dd, struct request *rq)
+{
+ const int data_dir = rq_data_dir(rq);
+
+ if (dd->next_rq[data_dir] == rq)
+ dd->next_rq[data_dir] = deadline_latter_request(rq);
+
+ elv_rb_del(deadline_rb_root(dd, rq), rq);
+}
+
+/*
+ * remove rq from rbtree and fifo.
+ */
+static void deadline_remove_request(struct request_queue *q, struct request *rq)
+{
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ list_del_init(&rq->queuelist);
+
+ /*
+ * We might not be on the rbtree, if we are doing an insert merge
+ */
+ if (!RB_EMPTY_NODE(&rq->rb_node))
+ deadline_del_rq_rb(dd, rq);
+
+ elv_rqhash_del(q, rq);
+ if (q->last_merge == rq)
+ q->last_merge = NULL;
+}
+
+static void dd_request_merged(struct request_queue *q, struct request *req,
+ enum elv_merge type)
+{
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ /*
+ * if the merge was a front merge, we need to reposition request
+ */
+ if (type == ELEVATOR_FRONT_MERGE) {
+ elv_rb_del(deadline_rb_root(dd, req), req);
+ deadline_add_rq_rb(dd, req);
+ }
+}
+
+static void dd_merged_requests(struct request_queue *q, struct request *req,
+ struct request *next)
+{
+ /*
+ * if next expires before rq, assign its expire time to rq
+ * and move into next position (next will be deleted) in fifo
+ */
+ if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
+ if (time_before((unsigned long)next->fifo_time,
+ (unsigned long)req->fifo_time)) {
+ list_move(&req->queuelist, &next->queuelist);
+ req->fifo_time = next->fifo_time;
+ }
+ }
+
+ /*
+ * kill knowledge of next, this one is a goner
+ */
+ deadline_remove_request(q, next);
+}
+
+/*
+ * move an entry to dispatch queue
+ */
+static void
+deadline_move_request(struct deadline_data *dd, struct request *rq)
+{
+ const int data_dir = rq_data_dir(rq);
+
+ dd->next_rq[READ] = NULL;
+ dd->next_rq[WRITE] = NULL;
+ dd->next_rq[data_dir] = deadline_latter_request(rq);
+
+ /*
+ * take it off the sort and fifo list
+ */
+ deadline_remove_request(rq->q, rq);
+}
+
+/*
+ * deadline_check_fifo returns 0 if there are no expired requests on the fifo,
+ * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir])
+ */
+static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
+{
+ struct request *rq = rq_entry_fifo(dd->fifo_list[ddir].next);
+
+ /*
+ * rq is expired!
+ */
+ if (time_after_eq(jiffies, (unsigned long)rq->fifo_time))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * deadline_dispatch_requests selects the best request according to
+ * read/write expire, fifo_batch, etc
+ */
+static struct request *__dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
+{
+ struct deadline_data *dd = hctx->queue->elevator->elevator_data;
+ struct request *rq;
+ bool reads, writes;
+ int data_dir;
+
+ if (!list_empty(&dd->dispatch)) {
+ rq = list_first_entry(&dd->dispatch, struct request, queuelist);
+ list_del_init(&rq->queuelist);
+ goto done;
+ }
+
+ reads = !list_empty(&dd->fifo_list[READ]);
+ writes = !list_empty(&dd->fifo_list[WRITE]);
+
+ /*
+ * batches are currently reads XOR writes
+ */
+ if (dd->next_rq[WRITE])
+ rq = dd->next_rq[WRITE];
+ else
+ rq = dd->next_rq[READ];
+
+ if (rq && dd->batching < dd->fifo_batch)
+ /* we have a next request are still entitled to batch */
+ goto dispatch_request;
+
+ /*
+ * at this point we are not running a batch. select the appropriate
+ * data direction (read / write)
+ */
+
+ if (reads) {
+ BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[READ]));
+
+ if (writes && (dd->starved++ >= dd->writes_starved))
+ goto dispatch_writes;
+
+ data_dir = READ;
+
+ goto dispatch_find_request;
+ }
+
+ /*
+ * there are either no reads or writes have been starved
+ */
+
+ if (writes) {
+dispatch_writes:
+ BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[WRITE]));
+
+ dd->starved = 0;
+
+ data_dir = WRITE;
+
+ goto dispatch_find_request;
+ }
+
+ return NULL;
+
+dispatch_find_request:
+ /*
+ * we are not running a batch, find best request for selected data_dir
+ */
+ if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) {
+ /*
+ * A deadline has expired, the last request was in the other
+ * direction, or we have run out of higher-sectored requests.
+ * Start again from the request with the earliest expiry time.
+ */
+ rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
+ } else {
+ /*
+ * The last req was the same dir and we have a next request in
+ * sort order. No expired requests so continue on from here.
+ */
+ rq = dd->next_rq[data_dir];
+ }
+
+ dd->batching = 0;
+
+dispatch_request:
+ /*
+ * rq is the selected appropriate request.
+ */
+ dd->batching++;
+ deadline_move_request(dd, rq);
+done:
+ rq->rq_flags |= RQF_STARTED;
+ return rq;
+}
+
+static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
+{
+ struct deadline_data *dd = hctx->queue->elevator->elevator_data;
+ struct request *rq;
+
+ spin_lock(&dd->lock);
+ rq = __dd_dispatch_request(hctx);
+ spin_unlock(&dd->lock);
+
+ return rq;
+}
+
+static void dd_exit_queue(struct elevator_queue *e)
+{
+ struct deadline_data *dd = e->elevator_data;
+
+ BUG_ON(!list_empty(&dd->fifo_list[READ]));
+ BUG_ON(!list_empty(&dd->fifo_list[WRITE]));
+
+ kfree(dd);
+}
+
+/*
+ * initialize elevator private data (deadline_data).
+ */
+static int dd_init_queue(struct request_queue *q, struct elevator_type *e)
+{
+ struct deadline_data *dd;
+ struct elevator_queue *eq;
+
+ eq = elevator_alloc(q, e);
+ if (!eq)
+ return -ENOMEM;
+
+ dd = kzalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
+ if (!dd) {
+ kobject_put(&eq->kobj);
+ return -ENOMEM;
+ }
+ eq->elevator_data = dd;
+
+ INIT_LIST_HEAD(&dd->fifo_list[READ]);
+ INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
+ dd->sort_list[READ] = RB_ROOT;
+ dd->sort_list[WRITE] = RB_ROOT;
+ dd->fifo_expire[READ] = read_expire;
+ dd->fifo_expire[WRITE] = write_expire;
+ dd->writes_starved = writes_starved;
+ dd->front_merges = 1;
+ dd->fifo_batch = fifo_batch;
+ spin_lock_init(&dd->lock);
+ INIT_LIST_HEAD(&dd->dispatch);
+
+ q->elevator = eq;
+ return 0;
+}
+
+static int dd_request_merge(struct request_queue *q, struct request **rq,
+ struct bio *bio)
+{
+ struct deadline_data *dd = q->elevator->elevator_data;
+ sector_t sector = bio_end_sector(bio);
+ struct request *__rq;
+
+ if (!dd->front_merges)
+ return ELEVATOR_NO_MERGE;
+
+ __rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
+ if (__rq) {
+ BUG_ON(sector != blk_rq_pos(__rq));
+
+ if (elv_bio_merge_ok(__rq, bio)) {
+ *rq = __rq;
+ return ELEVATOR_FRONT_MERGE;
+ }
+ }
+
+ return ELEVATOR_NO_MERGE;
+}
+
+static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
+{
+ struct request_queue *q = hctx->queue;
+ struct deadline_data *dd = q->elevator->elevator_data;
+ struct request *free = NULL;
+ bool ret;
+
+ spin_lock(&dd->lock);
+ ret = blk_mq_sched_try_merge(q, bio, &free);
+ spin_unlock(&dd->lock);
+
+ if (free)
+ blk_mq_free_request(free);
+
+ return ret;
+}
+
+/*
+ * add rq to rbtree and fifo
+ */
+static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
+ bool at_head)
+{
+ struct request_queue *q = hctx->queue;
+ struct deadline_data *dd = q->elevator->elevator_data;
+ const int data_dir = rq_data_dir(rq);
+
+ if (blk_mq_sched_try_insert_merge(q, rq))
+ return;
+
+ blk_mq_sched_request_inserted(rq);
+
+ if (at_head || blk_rq_is_passthrough(rq)) {
+ if (at_head)
+ list_add(&rq->queuelist, &dd->dispatch);
+ else
+ list_add_tail(&rq->queuelist, &dd->dispatch);
+ } else {
+ deadline_add_rq_rb(dd, rq);
+
+ if (rq_mergeable(rq)) {
+ elv_rqhash_add(q, rq);
+ if (!q->last_merge)
+ q->last_merge = rq;
+ }
+
+ /*
+ * set expire time and add to fifo list
+ */
+ rq->fifo_time = jiffies + dd->fifo_expire[data_dir];
+ list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]);
+ }
+}
+
+static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
+ struct list_head *list, bool at_head)
+{
+ struct request_queue *q = hctx->queue;
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ spin_lock(&dd->lock);
+ while (!list_empty(list)) {
+ struct request *rq;
+
+ rq = list_first_entry(list, struct request, queuelist);
+ list_del_init(&rq->queuelist);
+ dd_insert_request(hctx, rq, at_head);
+ }
+ spin_unlock(&dd->lock);
+}
+
+static bool dd_has_work(struct blk_mq_hw_ctx *hctx)
+{
+ struct deadline_data *dd = hctx->queue->elevator->elevator_data;
+
+ return !list_empty_careful(&dd->dispatch) ||
+ !list_empty_careful(&dd->fifo_list[0]) ||
+ !list_empty_careful(&dd->fifo_list[1]);
+}
+
+/*
+ * sysfs parts below
+ */
+static ssize_t
+deadline_var_show(int var, char *page)
+{
+ return sprintf(page, "%d\n", var);
+}
+
+static void
+deadline_var_store(int *var, const char *page)
+{
+ char *p = (char *) page;
+
+ *var = simple_strtol(p, &p, 10);
+}
+
+#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
+static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+{ \
+ struct deadline_data *dd = e->elevator_data; \
+ int __data = __VAR; \
+ if (__CONV) \
+ __data = jiffies_to_msecs(__data); \
+ return deadline_var_show(__data, (page)); \
+}
+SHOW_FUNCTION(deadline_read_expire_show, dd->fifo_expire[READ], 1);
+SHOW_FUNCTION(deadline_write_expire_show, dd->fifo_expire[WRITE], 1);
+SHOW_FUNCTION(deadline_writes_starved_show, dd->writes_starved, 0);
+SHOW_FUNCTION(deadline_front_merges_show, dd->front_merges, 0);
+SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0);
+#undef SHOW_FUNCTION
+
+#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
+{ \
+ struct deadline_data *dd = e->elevator_data; \
+ int __data; \
+ deadline_var_store(&__data, (page)); \
+ if (__data < (MIN)) \
+ __data = (MIN); \
+ else if (__data > (MAX)) \
+ __data = (MAX); \
+ if (__CONV) \
+ *(__PTR) = msecs_to_jiffies(__data); \
+ else \
+ *(__PTR) = __data; \
+ return count; \
+}
+STORE_FUNCTION(deadline_read_expire_store, &dd->fifo_expire[READ], 0, INT_MAX, 1);
+STORE_FUNCTION(deadline_write_expire_store, &dd->fifo_expire[WRITE], 0, INT_MAX, 1);
+STORE_FUNCTION(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX, 0);
+STORE_FUNCTION(deadline_front_merges_store, &dd->front_merges, 0, 1, 0);
+STORE_FUNCTION(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX, 0);
+#undef STORE_FUNCTION
+
+#define DD_ATTR(name) \
+ __ATTR(name, S_IRUGO|S_IWUSR, deadline_##name##_show, \
+ deadline_##name##_store)
+
+static struct elv_fs_entry deadline_attrs[] = {
+ DD_ATTR(read_expire),
+ DD_ATTR(write_expire),
+ DD_ATTR(writes_starved),
+ DD_ATTR(front_merges),
+ DD_ATTR(fifo_batch),
+ __ATTR_NULL
+};
+
+#ifdef CONFIG_BLK_DEBUG_FS
+#define DEADLINE_DEBUGFS_DDIR_ATTRS(ddir, name) \
+static void *deadline_##name##_fifo_start(struct seq_file *m, \
+ loff_t *pos) \
+ __acquires(&dd->lock) \
+{ \
+ struct request_queue *q = m->private; \
+ struct deadline_data *dd = q->elevator->elevator_data; \
+ \
+ spin_lock(&dd->lock); \
+ return seq_list_start(&dd->fifo_list[ddir], *pos); \
+} \
+ \
+static void *deadline_##name##_fifo_next(struct seq_file *m, void *v, \
+ loff_t *pos) \
+{ \
+ struct request_queue *q = m->private; \
+ struct deadline_data *dd = q->elevator->elevator_data; \
+ \
+ return seq_list_next(v, &dd->fifo_list[ddir], pos); \
+} \
+ \
+static void deadline_##name##_fifo_stop(struct seq_file *m, void *v) \
+ __releases(&dd->lock) \
+{ \
+ struct request_queue *q = m->private; \
+ struct deadline_data *dd = q->elevator->elevator_data; \
+ \
+ spin_unlock(&dd->lock); \
+} \
+ \
+static const struct seq_operations deadline_##name##_fifo_seq_ops = { \
+ .start = deadline_##name##_fifo_start, \
+ .next = deadline_##name##_fifo_next, \
+ .stop = deadline_##name##_fifo_stop, \
+ .show = blk_mq_debugfs_rq_show, \
+}; \
+ \
+static int deadline_##name##_next_rq_show(void *data, \
+ struct seq_file *m) \
+{ \
+ struct request_queue *q = data; \
+ struct deadline_data *dd = q->elevator->elevator_data; \
+ struct request *rq = dd->next_rq[ddir]; \
+ \
+ if (rq) \
+ __blk_mq_debugfs_rq_show(m, rq); \
+ return 0; \
+}
+DEADLINE_DEBUGFS_DDIR_ATTRS(READ, read)
+DEADLINE_DEBUGFS_DDIR_ATTRS(WRITE, write)
+#undef DEADLINE_DEBUGFS_DDIR_ATTRS
+
+static int deadline_batching_show(void *data, struct seq_file *m)
+{
+ struct request_queue *q = data;
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ seq_printf(m, "%u\n", dd->batching);
+ return 0;
+}
+
+static int deadline_starved_show(void *data, struct seq_file *m)
+{
+ struct request_queue *q = data;
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ seq_printf(m, "%u\n", dd->starved);
+ return 0;
+}
+
+static void *deadline_dispatch_start(struct seq_file *m, loff_t *pos)
+ __acquires(&dd->lock)
+{
+ struct request_queue *q = m->private;
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ spin_lock(&dd->lock);
+ return seq_list_start(&dd->dispatch, *pos);
+}
+
+static void *deadline_dispatch_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct request_queue *q = m->private;
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ return seq_list_next(v, &dd->dispatch, pos);
+}
+
+static void deadline_dispatch_stop(struct seq_file *m, void *v)
+ __releases(&dd->lock)
+{
+ struct request_queue *q = m->private;
+ struct deadline_data *dd = q->elevator->elevator_data;
+
+ spin_unlock(&dd->lock);
+}
+
+static const struct seq_operations deadline_dispatch_seq_ops = {
+ .start = deadline_dispatch_start,
+ .next = deadline_dispatch_next,
+ .stop = deadline_dispatch_stop,
+ .show = blk_mq_debugfs_rq_show,
+};
+
+#define DEADLINE_QUEUE_DDIR_ATTRS(name) \
+ {#name "_fifo_list", 0400, .seq_ops = &deadline_##name##_fifo_seq_ops}, \
+ {#name "_next_rq", 0400, deadline_##name##_next_rq_show}
+static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = {
+ DEADLINE_QUEUE_DDIR_ATTRS(read),
+ DEADLINE_QUEUE_DDIR_ATTRS(write),
+ {"batching", 0400, deadline_batching_show},
+ {"starved", 0400, deadline_starved_show},
+ {"dispatch", 0400, .seq_ops = &deadline_dispatch_seq_ops},
+ {},
+};
+#undef DEADLINE_QUEUE_DDIR_ATTRS
+#endif
+
+static struct elevator_type mq_deadline = {
+ .ops.mq = {
+ .insert_requests = dd_insert_requests,
+ .dispatch_request = dd_dispatch_request,
+ .next_request = elv_rb_latter_request,
+ .former_request = elv_rb_former_request,
+ .bio_merge = dd_bio_merge,
+ .request_merge = dd_request_merge,
+ .requests_merged = dd_merged_requests,
+ .request_merged = dd_request_merged,
+ .has_work = dd_has_work,
+ .init_sched = dd_init_queue,
+ .exit_sched = dd_exit_queue,
+ },
+
+ .uses_mq = true,
+#ifdef CONFIG_BLK_DEBUG_FS
+ .queue_debugfs_attrs = deadline_queue_debugfs_attrs,
+#endif
+ .elevator_attrs = deadline_attrs,
+ .elevator_name = "mq-deadline",
+ .elevator_owner = THIS_MODULE,
+};
+MODULE_ALIAS("mq-deadline-iosched");
+
+static int __init deadline_init(void)
+{
+ return elv_register(&mq_deadline);
+}
+
+static void __exit deadline_exit(void)
+{
+ elv_unregister(&mq_deadline);
+}
+
+module_init(deadline_init);
+module_exit(deadline_exit);
+
+MODULE_AUTHOR("Jens Axboe");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MQ deadline IO scheduler");
diff --git a/src/kernel/linux/v4.14/block/noop-iosched.c b/src/kernel/linux/v4.14/block/noop-iosched.c
new file mode 100644
index 0000000..2d1b15d
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/noop-iosched.c
@@ -0,0 +1,124 @@
+/*
+ * elevator noop
+ */
+#include <linux/blkdev.h>
+#include <linux/elevator.h>
+#include <linux/bio.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+
+struct noop_data {
+ struct list_head queue;
+};
+
+static void noop_merged_requests(struct request_queue *q, struct request *rq,
+ struct request *next)
+{
+ list_del_init(&next->queuelist);
+}
+
+static int noop_dispatch(struct request_queue *q, int force)
+{
+ struct noop_data *nd = q->elevator->elevator_data;
+ struct request *rq;
+
+ rq = list_first_entry_or_null(&nd->queue, struct request, queuelist);
+ if (rq) {
+ list_del_init(&rq->queuelist);
+ elv_dispatch_sort(q, rq);
+ return 1;
+ }
+ return 0;
+}
+
+static void noop_add_request(struct request_queue *q, struct request *rq)
+{
+ struct noop_data *nd = q->elevator->elevator_data;
+
+ list_add_tail(&rq->queuelist, &nd->queue);
+}
+
+static struct request *
+noop_former_request(struct request_queue *q, struct request *rq)
+{
+ struct noop_data *nd = q->elevator->elevator_data;
+
+ if (rq->queuelist.prev == &nd->queue)
+ return NULL;
+ return list_prev_entry(rq, queuelist);
+}
+
+static struct request *
+noop_latter_request(struct request_queue *q, struct request *rq)
+{
+ struct noop_data *nd = q->elevator->elevator_data;
+
+ if (rq->queuelist.next == &nd->queue)
+ return NULL;
+ return list_next_entry(rq, queuelist);
+}
+
+static int noop_init_queue(struct request_queue *q, struct elevator_type *e)
+{
+ struct noop_data *nd;
+ struct elevator_queue *eq;
+
+ eq = elevator_alloc(q, e);
+ if (!eq)
+ return -ENOMEM;
+
+ nd = kmalloc_node(sizeof(*nd), GFP_KERNEL, q->node);
+ if (!nd) {
+ kobject_put(&eq->kobj);
+ return -ENOMEM;
+ }
+ eq->elevator_data = nd;
+
+ INIT_LIST_HEAD(&nd->queue);
+
+ spin_lock_irq(q->queue_lock);
+ q->elevator = eq;
+ spin_unlock_irq(q->queue_lock);
+ return 0;
+}
+
+static void noop_exit_queue(struct elevator_queue *e)
+{
+ struct noop_data *nd = e->elevator_data;
+
+ BUG_ON(!list_empty(&nd->queue));
+ kfree(nd);
+}
+
+static struct elevator_type elevator_noop = {
+ .ops.sq = {
+ .elevator_merge_req_fn = noop_merged_requests,
+ .elevator_dispatch_fn = noop_dispatch,
+ .elevator_add_req_fn = noop_add_request,
+ .elevator_former_req_fn = noop_former_request,
+ .elevator_latter_req_fn = noop_latter_request,
+ .elevator_init_fn = noop_init_queue,
+ .elevator_exit_fn = noop_exit_queue,
+ },
+ .elevator_name = "noop",
+ .elevator_owner = THIS_MODULE,
+};
+
+static int __init noop_init(void)
+{
+ return elv_register(&elevator_noop);
+}
+
+static void __exit noop_exit(void)
+{
+ elv_unregister(&elevator_noop);
+}
+
+module_init(noop_init);
+module_exit(noop_exit);
+
+
+MODULE_AUTHOR("Jens Axboe");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("No-op IO scheduler");
diff --git a/src/kernel/linux/v4.14/block/opal_proto.h b/src/kernel/linux/v4.14/block/opal_proto.h
new file mode 100644
index 0000000..e20be82
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/opal_proto.h
@@ -0,0 +1,453 @@
+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * Authors:
+ * Rafael Antognolli <rafael.antognolli@intel.com>
+ * Scott Bauer <scott.bauer@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#include <linux/types.h>
+
+#ifndef _OPAL_PROTO_H
+#define _OPAL_PROTO_H
+
+/*
+ * These constant values come from:
+ * SPC-4 section
+ * 6.30 SECURITY PROTOCOL IN command / table 265.
+ */
+enum {
+ TCG_SECP_00 = 0,
+ TCG_SECP_01,
+};
+
+/*
+ * Token defs derived from:
+ * TCG_Storage_Architecture_Core_Spec_v2.01_r1.00
+ * 3.2.2 Data Stream Encoding
+ */
+enum opal_response_token {
+ OPAL_DTA_TOKENID_BYTESTRING = 0xe0,
+ OPAL_DTA_TOKENID_SINT = 0xe1,
+ OPAL_DTA_TOKENID_UINT = 0xe2,
+ OPAL_DTA_TOKENID_TOKEN = 0xe3, /* actual token is returned */
+ OPAL_DTA_TOKENID_INVALID = 0X0
+};
+
+#define DTAERROR_NO_METHOD_STATUS 0x89
+#define GENERIC_HOST_SESSION_NUM 0x41
+
+#define TPER_SYNC_SUPPORTED 0x01
+#define MBR_ENABLED_MASK 0x10
+
+#define TINY_ATOM_DATA_MASK 0x3F
+#define TINY_ATOM_SIGNED 0x40
+
+#define SHORT_ATOM_ID 0x80
+#define SHORT_ATOM_BYTESTRING 0x20
+#define SHORT_ATOM_SIGNED 0x10
+#define SHORT_ATOM_LEN_MASK 0xF
+
+#define MEDIUM_ATOM_ID 0xC0
+#define MEDIUM_ATOM_BYTESTRING 0x10
+#define MEDIUM_ATOM_SIGNED 0x8
+#define MEDIUM_ATOM_LEN_MASK 0x7
+
+#define LONG_ATOM_ID 0xe0
+#define LONG_ATOM_BYTESTRING 0x2
+#define LONG_ATOM_SIGNED 0x1
+
+/* Derived from TCG Core spec 2.01 Section:
+ * 3.2.2.1
+ * Data Type
+ */
+#define TINY_ATOM_BYTE 0x7F
+#define SHORT_ATOM_BYTE 0xBF
+#define MEDIUM_ATOM_BYTE 0xDF
+#define LONG_ATOM_BYTE 0xE3
+
+#define OPAL_INVAL_PARAM 12
+#define OPAL_MANUFACTURED_INACTIVE 0x08
+#define OPAL_DISCOVERY_COMID 0x0001
+
+#define LOCKING_RANGE_NON_GLOBAL 0x03
+/*
+ * User IDs used in the TCG storage SSCs
+ * Derived from: TCG_Storage_Architecture_Core_Spec_v2.01_r1.00
+ * Section: 6.3 Assigned UIDs
+ */
+#define OPAL_UID_LENGTH 8
+#define OPAL_METHOD_LENGTH 8
+#define OPAL_MSID_KEYLEN 15
+#define OPAL_UID_LENGTH_HALF 4
+
+/* Enum to index OPALUID array */
+enum opal_uid {
+ /* users */
+ OPAL_SMUID_UID,
+ OPAL_THISSP_UID,
+ OPAL_ADMINSP_UID,
+ OPAL_LOCKINGSP_UID,
+ OPAL_ENTERPRISE_LOCKINGSP_UID,
+ OPAL_ANYBODY_UID,
+ OPAL_SID_UID,
+ OPAL_ADMIN1_UID,
+ OPAL_USER1_UID,
+ OPAL_USER2_UID,
+ OPAL_PSID_UID,
+ OPAL_ENTERPRISE_BANDMASTER0_UID,
+ OPAL_ENTERPRISE_ERASEMASTER_UID,
+ /* tables */
+ OPAL_LOCKINGRANGE_GLOBAL,
+ OPAL_LOCKINGRANGE_ACE_RDLOCKED,
+ OPAL_LOCKINGRANGE_ACE_WRLOCKED,
+ OPAL_MBRCONTROL,
+ OPAL_MBR,
+ OPAL_AUTHORITY_TABLE,
+ OPAL_C_PIN_TABLE,
+ OPAL_LOCKING_INFO_TABLE,
+ OPAL_ENTERPRISE_LOCKING_INFO_TABLE,
+ /* C_PIN_TABLE object ID's */
+ OPAL_C_PIN_MSID,
+ OPAL_C_PIN_SID,
+ OPAL_C_PIN_ADMIN1,
+ /* half UID's (only first 4 bytes used) */
+ OPAL_HALF_UID_AUTHORITY_OBJ_REF,
+ OPAL_HALF_UID_BOOLEAN_ACE,
+ /* omitted optional parameter */
+ OPAL_UID_HEXFF,
+};
+
+#define OPAL_METHOD_LENGTH 8
+
+/* Enum for indexing the OPALMETHOD array */
+enum opal_method {
+ OPAL_PROPERTIES,
+ OPAL_STARTSESSION,
+ OPAL_REVERT,
+ OPAL_ACTIVATE,
+ OPAL_EGET,
+ OPAL_ESET,
+ OPAL_NEXT,
+ OPAL_EAUTHENTICATE,
+ OPAL_GETACL,
+ OPAL_GENKEY,
+ OPAL_REVERTSP,
+ OPAL_GET,
+ OPAL_SET,
+ OPAL_AUTHENTICATE,
+ OPAL_RANDOM,
+ OPAL_ERASE,
+};
+
+enum opal_token {
+ /* Boolean */
+ OPAL_TRUE = 0x01,
+ OPAL_FALSE = 0x00,
+ OPAL_BOOLEAN_EXPR = 0x03,
+ /* cellblocks */
+ OPAL_TABLE = 0x00,
+ OPAL_STARTROW = 0x01,
+ OPAL_ENDROW = 0x02,
+ OPAL_STARTCOLUMN = 0x03,
+ OPAL_ENDCOLUMN = 0x04,
+ OPAL_VALUES = 0x01,
+ /* authority table */
+ OPAL_PIN = 0x03,
+ /* locking tokens */
+ OPAL_RANGESTART = 0x03,
+ OPAL_RANGELENGTH = 0x04,
+ OPAL_READLOCKENABLED = 0x05,
+ OPAL_WRITELOCKENABLED = 0x06,
+ OPAL_READLOCKED = 0x07,
+ OPAL_WRITELOCKED = 0x08,
+ OPAL_ACTIVEKEY = 0x0A,
+ /* locking info table */
+ OPAL_MAXRANGES = 0x04,
+ /* mbr control */
+ OPAL_MBRENABLE = 0x01,
+ OPAL_MBRDONE = 0x02,
+ /* properties */
+ OPAL_HOSTPROPERTIES = 0x00,
+ /* atoms */
+ OPAL_STARTLIST = 0xf0,
+ OPAL_ENDLIST = 0xf1,
+ OPAL_STARTNAME = 0xf2,
+ OPAL_ENDNAME = 0xf3,
+ OPAL_CALL = 0xf8,
+ OPAL_ENDOFDATA = 0xf9,
+ OPAL_ENDOFSESSION = 0xfa,
+ OPAL_STARTTRANSACTON = 0xfb,
+ OPAL_ENDTRANSACTON = 0xfC,
+ OPAL_EMPTYATOM = 0xff,
+ OPAL_WHERE = 0x00,
+};
+
+/* Locking state for a locking range */
+enum opal_lockingstate {
+ OPAL_LOCKING_READWRITE = 0x01,
+ OPAL_LOCKING_READONLY = 0x02,
+ OPAL_LOCKING_LOCKED = 0x03,
+};
+
+/* Packets derived from:
+ * TCG_Storage_Architecture_Core_Spec_v2.01_r1.00
+ * Secion: 3.2.3 ComPackets, Packets & Subpackets
+ */
+
+/* Comm Packet (header) for transmissions. */
+struct opal_compacket {
+ __be32 reserved0;
+ u8 extendedComID[4];
+ __be32 outstandingData;
+ __be32 minTransfer;
+ __be32 length;
+};
+
+/* Packet structure. */
+struct opal_packet {
+ __be32 tsn;
+ __be32 hsn;
+ __be32 seq_number;
+ __be16 reserved0;
+ __be16 ack_type;
+ __be32 acknowledgment;
+ __be32 length;
+};
+
+/* Data sub packet header */
+struct opal_data_subpacket {
+ u8 reserved0[6];
+ __be16 kind;
+ __be32 length;
+};
+
+/* header of a response */
+struct opal_header {
+ struct opal_compacket cp;
+ struct opal_packet pkt;
+ struct opal_data_subpacket subpkt;
+};
+
+#define FC_TPER 0x0001
+#define FC_LOCKING 0x0002
+#define FC_GEOMETRY 0x0003
+#define FC_ENTERPRISE 0x0100
+#define FC_DATASTORE 0x0202
+#define FC_SINGLEUSER 0x0201
+#define FC_OPALV100 0x0200
+#define FC_OPALV200 0x0203
+
+/*
+ * The Discovery 0 Header. As defined in
+ * Opal SSC Documentation
+ * Section: 3.3.5 Capability Discovery
+ */
+struct d0_header {
+ __be32 length; /* the length of the header 48 in 2.00.100 */
+ __be32 revision; /**< revision of the header 1 in 2.00.100 */
+ __be32 reserved01;
+ __be32 reserved02;
+ /*
+ * the remainder of the structure is vendor specific and will not be
+ * addressed now
+ */
+ u8 ignored[32];
+};
+
+/*
+ * TPer Feature Descriptor. Contains flags indicating support for the
+ * TPer features described in the OPAL specification. The names match the
+ * OPAL terminology
+ *
+ * code == 0x001 in 2.00.100
+ */
+struct d0_tper_features {
+ /*
+ * supported_features bits:
+ * bit 7: reserved
+ * bit 6: com ID management
+ * bit 5: reserved
+ * bit 4: streaming support
+ * bit 3: buffer management
+ * bit 2: ACK/NACK
+ * bit 1: async
+ * bit 0: sync
+ */
+ u8 supported_features;
+ /*
+ * bytes 5 through 15 are reserved, but we represent the first 3 as
+ * u8 to keep the other two 32bits integers aligned.
+ */
+ u8 reserved01[3];
+ __be32 reserved02;
+ __be32 reserved03;
+};
+
+/*
+ * Locking Feature Descriptor. Contains flags indicating support for the
+ * locking features described in the OPAL specification. The names match the
+ * OPAL terminology
+ *
+ * code == 0x0002 in 2.00.100
+ */
+struct d0_locking_features {
+ /*
+ * supported_features bits:
+ * bits 6-7: reserved
+ * bit 5: MBR done
+ * bit 4: MBR enabled
+ * bit 3: media encryption
+ * bit 2: locked
+ * bit 1: locking enabled
+ * bit 0: locking supported
+ */
+ u8 supported_features;
+ /*
+ * bytes 5 through 15 are reserved, but we represent the first 3 as
+ * u8 to keep the other two 32bits integers aligned.
+ */
+ u8 reserved01[3];
+ __be32 reserved02;
+ __be32 reserved03;
+};
+
+/*
+ * Geometry Feature Descriptor. Contains flags indicating support for the
+ * geometry features described in the OPAL specification. The names match the
+ * OPAL terminology
+ *
+ * code == 0x0003 in 2.00.100
+ */
+struct d0_geometry_features {
+ /*
+ * skip 32 bits from header, needed to align the struct to 64 bits.
+ */
+ u8 header[4];
+ /*
+ * reserved01:
+ * bits 1-6: reserved
+ * bit 0: align
+ */
+ u8 reserved01;
+ u8 reserved02[7];
+ __be32 logical_block_size;
+ __be64 alignment_granularity;
+ __be64 lowest_aligned_lba;
+};
+
+/*
+ * Enterprise SSC Feature
+ *
+ * code == 0x0100
+ */
+struct d0_enterprise_ssc {
+ __be16 baseComID;
+ __be16 numComIDs;
+ /* range_crossing:
+ * bits 1-6: reserved
+ * bit 0: range crossing
+ */
+ u8 range_crossing;
+ u8 reserved01;
+ __be16 reserved02;
+ __be32 reserved03;
+ __be32 reserved04;
+};
+
+/*
+ * Opal V1 feature
+ *
+ * code == 0x0200
+ */
+struct d0_opal_v100 {
+ __be16 baseComID;
+ __be16 numComIDs;
+};
+
+/*
+ * Single User Mode feature
+ *
+ * code == 0x0201
+ */
+struct d0_single_user_mode {
+ __be32 num_locking_objects;
+ /* reserved01:
+ * bit 0: any
+ * bit 1: all
+ * bit 2: policy
+ * bits 3-7: reserved
+ */
+ u8 reserved01;
+ u8 reserved02;
+ __be16 reserved03;
+ __be32 reserved04;
+};
+
+/*
+ * Additonal Datastores feature
+ *
+ * code == 0x0202
+ */
+struct d0_datastore_table {
+ __be16 reserved01;
+ __be16 max_tables;
+ __be32 max_size_tables;
+ __be32 table_size_alignment;
+};
+
+/*
+ * OPAL 2.0 feature
+ *
+ * code == 0x0203
+ */
+struct d0_opal_v200 {
+ __be16 baseComID;
+ __be16 numComIDs;
+ /* range_crossing:
+ * bits 1-6: reserved
+ * bit 0: range crossing
+ */
+ u8 range_crossing;
+ /* num_locking_admin_auth:
+ * not aligned to 16 bits, so use two u8.
+ * stored in big endian:
+ * 0: MSB
+ * 1: LSB
+ */
+ u8 num_locking_admin_auth[2];
+ /* num_locking_user_auth:
+ * not aligned to 16 bits, so use two u8.
+ * stored in big endian:
+ * 0: MSB
+ * 1: LSB
+ */
+ u8 num_locking_user_auth[2];
+ u8 initialPIN;
+ u8 revertedPIN;
+ u8 reserved01;
+ __be32 reserved02;
+};
+
+/* Union of features used to parse the discovery 0 response */
+struct d0_features {
+ __be16 code;
+ /*
+ * r_version bits:
+ * bits 4-7: version
+ * bits 0-3: reserved
+ */
+ u8 r_version;
+ u8 length;
+ u8 features[];
+};
+
+#endif /* _OPAL_PROTO_H */
diff --git a/src/kernel/linux/v4.14/block/partition-generic.c b/src/kernel/linux/v4.14/block/partition-generic.c
new file mode 100644
index 0000000..db57cce
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partition-generic.c
@@ -0,0 +1,672 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Code extracted from drivers/block/genhd.c
+ * Copyright (C) 1991-1998 Linus Torvalds
+ * Re-organised Feb 1998 Russell King
+ *
+ * We now have independent partition support from the
+ * block drivers, which allows all the partition code to
+ * be grouped in one location, and it to be mostly self
+ * contained.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/kmod.h>
+#include <linux/ctype.h>
+#include <linux/genhd.h>
+#include <linux/blktrace_api.h>
+
+#include "partitions/check.h"
+
+#ifdef CONFIG_BLK_DEV_MD
+extern void md_autodetect_dev(dev_t dev);
+#endif
+
+/*
+ * disk_name() is used by partition check code and the genhd driver.
+ * It formats the devicename of the indicated disk into
+ * the supplied buffer (of size at least 32), and returns
+ * a pointer to that same buffer (for convenience).
+ */
+
+char *disk_name(struct gendisk *hd, int partno, char *buf)
+{
+ if (!partno)
+ snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
+ else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
+ snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
+ else
+ snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
+
+ return buf;
+}
+
+const char *bdevname(struct block_device *bdev, char *buf)
+{
+ return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
+}
+
+EXPORT_SYMBOL(bdevname);
+
+const char *bio_devname(struct bio *bio, char *buf)
+{
+ return disk_name(bio->bi_disk, bio->bi_partno, buf);
+}
+EXPORT_SYMBOL(bio_devname);
+
+/*
+ * There's very little reason to use this, you should really
+ * have a struct block_device just about everywhere and use
+ * bdevname() instead.
+ */
+const char *__bdevname(dev_t dev, char *buffer)
+{
+ scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
+ MAJOR(dev), MINOR(dev));
+ return buffer;
+}
+
+EXPORT_SYMBOL(__bdevname);
+
+static ssize_t part_partition_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+
+ return sprintf(buf, "%d\n", p->partno);
+}
+
+static ssize_t part_start_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+
+ return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
+}
+
+ssize_t part_size_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p));
+}
+
+static ssize_t part_ro_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ return sprintf(buf, "%d\n", p->policy ? 1 : 0);
+}
+
+static ssize_t part_alignment_offset_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
+}
+
+static ssize_t part_discard_alignment_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ return sprintf(buf, "%u\n", p->discard_alignment);
+}
+
+ssize_t part_stat_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ struct request_queue *q = part_to_disk(p)->queue;
+ unsigned int inflight[2];
+ int cpu;
+
+ cpu = part_stat_lock();
+ part_round_stats(q, cpu, p);
+ part_stat_unlock();
+ part_in_flight(q, p, inflight);
+ return sprintf(buf,
+ "%8lu %8lu %8llu %8u "
+ "%8lu %8lu %8llu %8u "
+ "%8u %8u %8u"
+ "\n",
+ part_stat_read(p, ios[READ]),
+ part_stat_read(p, merges[READ]),
+ (unsigned long long)part_stat_read(p, sectors[READ]),
+ jiffies_to_msecs(part_stat_read(p, ticks[READ])),
+ part_stat_read(p, ios[WRITE]),
+ part_stat_read(p, merges[WRITE]),
+ (unsigned long long)part_stat_read(p, sectors[WRITE]),
+ jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
+ inflight[0],
+ jiffies_to_msecs(part_stat_read(p, io_ticks)),
+ jiffies_to_msecs(part_stat_read(p, time_in_queue)));
+}
+
+ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ struct request_queue *q = part_to_disk(p)->queue;
+ unsigned int inflight[2];
+
+ part_in_flight_rw(q, p, inflight);
+ return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
+}
+
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+ssize_t part_fail_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+
+ return sprintf(buf, "%d\n", p->make_it_fail);
+}
+
+ssize_t part_fail_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ int i;
+
+ if (count > 0 && sscanf(buf, "%d", &i) > 0)
+ p->make_it_fail = (i == 0) ? 0 : 1;
+
+ return count;
+}
+#endif
+
+static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL);
+static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
+static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
+static DEVICE_ATTR(ro, S_IRUGO, part_ro_show, NULL);
+static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
+static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show,
+ NULL);
+static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
+static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+static struct device_attribute dev_attr_fail =
+ __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
+#endif
+
+static struct attribute *part_attrs[] = {
+ &dev_attr_partition.attr,
+ &dev_attr_start.attr,
+ &dev_attr_size.attr,
+ &dev_attr_ro.attr,
+ &dev_attr_alignment_offset.attr,
+ &dev_attr_discard_alignment.attr,
+ &dev_attr_stat.attr,
+ &dev_attr_inflight.attr,
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+ &dev_attr_fail.attr,
+#endif
+ NULL
+};
+
+static struct attribute_group part_attr_group = {
+ .attrs = part_attrs,
+};
+
+static const struct attribute_group *part_attr_groups[] = {
+ &part_attr_group,
+#ifdef CONFIG_BLK_DEV_IO_TRACE
+ &blk_trace_attr_group,
+#endif
+ NULL
+};
+
+static void part_release(struct device *dev)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ blk_free_devt(dev->devt);
+ hd_free_part(p);
+ kfree(p);
+}
+
+static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ struct hd_struct *part = dev_to_part(dev);
+
+ add_uevent_var(env, "PARTN=%u", part->partno);
+ if (part->info && part->info->volname[0])
+ add_uevent_var(env, "PARTNAME=%s", part->info->volname);
+ return 0;
+}
+
+struct device_type part_type = {
+ .name = "partition",
+ .groups = part_attr_groups,
+ .release = part_release,
+ .uevent = part_uevent,
+};
+
+static void delete_partition_rcu_cb(struct rcu_head *head)
+{
+ struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
+
+ part->start_sect = 0;
+ part->nr_sects = 0;
+ part_stat_set_all(part, 0);
+ put_device(part_to_dev(part));
+}
+
+void __delete_partition(struct percpu_ref *ref)
+{
+ struct hd_struct *part = container_of(ref, struct hd_struct, ref);
+ call_rcu(&part->rcu_head, delete_partition_rcu_cb);
+}
+
+/*
+ * Must be called either with bd_mutex held, before a disk can be opened or
+ * after all disk users are gone.
+ */
+void delete_partition(struct gendisk *disk, int partno)
+{
+ struct disk_part_tbl *ptbl =
+ rcu_dereference_protected(disk->part_tbl, 1);
+ struct hd_struct *part;
+
+ if (partno >= ptbl->len)
+ return;
+
+ part = rcu_dereference_protected(ptbl->part[partno], 1);
+ if (!part)
+ return;
+
+ rcu_assign_pointer(ptbl->part[partno], NULL);
+ rcu_assign_pointer(ptbl->last_lookup, NULL);
+ kobject_put(part->holder_dir);
+ device_del(part_to_dev(part));
+
+ hd_struct_kill(part);
+}
+
+static ssize_t whole_disk_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return 0;
+}
+static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
+ whole_disk_show, NULL);
+
+/*
+ * Must be called either with bd_mutex held, before a disk can be opened or
+ * after all disk users are gone.
+ */
+struct hd_struct *add_partition(struct gendisk *disk, int partno,
+ sector_t start, sector_t len, int flags,
+ struct partition_meta_info *info)
+{
+ struct hd_struct *p;
+ dev_t devt = MKDEV(0, 0);
+ struct device *ddev = disk_to_dev(disk);
+ struct device *pdev;
+ struct disk_part_tbl *ptbl;
+ const char *dname;
+ int err;
+
+ err = disk_expand_part_tbl(disk, partno);
+ if (err)
+ return ERR_PTR(err);
+ ptbl = rcu_dereference_protected(disk->part_tbl, 1);
+
+ if (ptbl->part[partno])
+ return ERR_PTR(-EBUSY);
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return ERR_PTR(-EBUSY);
+
+ if (!init_part_stats(p)) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+
+ seqcount_init(&p->nr_sects_seq);
+ pdev = part_to_dev(p);
+
+ p->start_sect = start;
+ p->alignment_offset =
+ queue_limit_alignment_offset(&disk->queue->limits, start);
+ p->discard_alignment =
+ queue_limit_discard_alignment(&disk->queue->limits, start);
+ p->nr_sects = len;
+ p->partno = partno;
+ p->policy = get_disk_ro(disk);
+
+ if (info) {
+ struct partition_meta_info *pinfo = alloc_part_info(disk);
+ if (!pinfo) {
+ err = -ENOMEM;
+ goto out_free_stats;
+ }
+ memcpy(pinfo, info, sizeof(*info));
+ p->info = pinfo;
+ }
+
+ dname = dev_name(ddev);
+ if (isdigit(dname[strlen(dname) - 1]))
+ dev_set_name(pdev, "%sp%d", dname, partno);
+ else
+ dev_set_name(pdev, "%s%d", dname, partno);
+
+ device_initialize(pdev);
+ pdev->class = &block_class;
+ pdev->type = &part_type;
+ pdev->parent = ddev;
+
+ err = blk_alloc_devt(p, &devt);
+ if (err)
+ goto out_free_info;
+ pdev->devt = devt;
+
+ /* delay uevent until 'holders' subdir is created */
+ dev_set_uevent_suppress(pdev, 1);
+ err = device_add(pdev);
+ if (err)
+ goto out_put;
+
+ err = -ENOMEM;
+ p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
+ if (!p->holder_dir)
+ goto out_del;
+
+ dev_set_uevent_suppress(pdev, 0);
+ if (flags & ADDPART_FLAG_WHOLEDISK) {
+ err = device_create_file(pdev, &dev_attr_whole_disk);
+ if (err)
+ goto out_del;
+ }
+
+ err = hd_ref_init(p);
+ if (err) {
+ if (flags & ADDPART_FLAG_WHOLEDISK)
+ goto out_remove_file;
+ goto out_del;
+ }
+
+ /* everything is up and running, commence */
+ rcu_assign_pointer(ptbl->part[partno], p);
+
+ /* suppress uevent if the disk suppresses it */
+ if (!dev_get_uevent_suppress(ddev))
+ kobject_uevent(&pdev->kobj, KOBJ_ADD);
+ return p;
+
+out_free_info:
+ free_part_info(p);
+out_free_stats:
+ free_part_stats(p);
+out_free:
+ kfree(p);
+ return ERR_PTR(err);
+out_remove_file:
+ device_remove_file(pdev, &dev_attr_whole_disk);
+out_del:
+ kobject_put(p->holder_dir);
+ device_del(pdev);
+out_put:
+ put_device(pdev);
+ return ERR_PTR(err);
+}
+
+static bool disk_unlock_native_capacity(struct gendisk *disk)
+{
+ const struct block_device_operations *bdops = disk->fops;
+
+ if (bdops->unlock_native_capacity &&
+ !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
+ printk(KERN_CONT "enabling native capacity\n");
+ bdops->unlock_native_capacity(disk);
+ disk->flags |= GENHD_FL_NATIVE_CAPACITY;
+ return true;
+ } else {
+ printk(KERN_CONT "truncated\n");
+ return false;
+ }
+}
+
+static int drop_partitions(struct gendisk *disk, struct block_device *bdev)
+{
+ struct disk_part_iter piter;
+ struct hd_struct *part;
+ int res;
+
+ if (bdev->bd_part_count || bdev->bd_super)
+ return -EBUSY;
+ res = invalidate_partition(disk, 0);
+ if (res)
+ return res;
+
+ disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
+ while ((part = disk_part_iter_next(&piter)))
+ delete_partition(disk, part->partno);
+ disk_part_iter_exit(&piter);
+
+ return 0;
+}
+
+static bool part_zone_aligned(struct gendisk *disk,
+ struct block_device *bdev,
+ sector_t from, sector_t size)
+{
+ unsigned int zone_sectors = bdev_zone_sectors(bdev);
+
+ /*
+ * If this function is called, then the disk is a zoned block device
+ * (host-aware or host-managed). This can be detected even if the
+ * zoned block device support is disabled (CONFIG_BLK_DEV_ZONED not
+ * set). In this case, however, only host-aware devices will be seen
+ * as a block device is not created for host-managed devices. Without
+ * zoned block device support, host-aware drives can still be used as
+ * regular block devices (no zone operation) and their zone size will
+ * be reported as 0. Allow this case.
+ */
+ if (!zone_sectors)
+ return true;
+
+ /*
+ * Check partition start and size alignement. If the drive has a
+ * smaller last runt zone, ignore it and allow the partition to
+ * use it. Check the zone size too: it should be a power of 2 number
+ * of sectors.
+ */
+ if (WARN_ON_ONCE(!is_power_of_2(zone_sectors))) {
+ u32 rem;
+
+ div_u64_rem(from, zone_sectors, &rem);
+ if (rem)
+ return false;
+ if ((from + size) < get_capacity(disk)) {
+ div_u64_rem(size, zone_sectors, &rem);
+ if (rem)
+ return false;
+ }
+
+ } else {
+
+ if (from & (zone_sectors - 1))
+ return false;
+ if ((from + size) < get_capacity(disk) &&
+ (size & (zone_sectors - 1)))
+ return false;
+
+ }
+
+ return true;
+}
+
+int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
+{
+ struct parsed_partitions *state = NULL;
+ struct hd_struct *part;
+ int p, highest, res;
+rescan:
+ if (state && !IS_ERR(state)) {
+ free_partitions(state);
+ state = NULL;
+ }
+
+ res = drop_partitions(disk, bdev);
+ if (res)
+ return res;
+
+ if (disk->fops->revalidate_disk)
+ disk->fops->revalidate_disk(disk);
+ check_disk_size_change(disk, bdev);
+ bdev->bd_invalidated = 0;
+ if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
+ return 0;
+ if (IS_ERR(state)) {
+ /*
+ * I/O error reading the partition table. If any
+ * partition code tried to read beyond EOD, retry
+ * after unlocking native capacity.
+ */
+ if (PTR_ERR(state) == -ENOSPC) {
+ printk(KERN_WARNING "%s: partition table beyond EOD, ",
+ disk->disk_name);
+ if (disk_unlock_native_capacity(disk))
+ goto rescan;
+ }
+ return -EIO;
+ }
+ /*
+ * If any partition code tried to read beyond EOD, try
+ * unlocking native capacity even if partition table is
+ * successfully read as we could be missing some partitions.
+ */
+ if (state->access_beyond_eod) {
+ printk(KERN_WARNING
+ "%s: partition table partially beyond EOD, ",
+ disk->disk_name);
+ if (disk_unlock_native_capacity(disk))
+ goto rescan;
+ }
+
+ /* tell userspace that the media / partition table may have changed */
+ kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+
+ /* Detect the highest partition number and preallocate
+ * disk->part_tbl. This is an optimization and not strictly
+ * necessary.
+ */
+ for (p = 1, highest = 0; p < state->limit; p++)
+ if (state->parts[p].size)
+ highest = p;
+
+ disk_expand_part_tbl(disk, highest);
+
+ /* add partitions */
+ for (p = 1; p < state->limit; p++) {
+ sector_t size, from;
+
+ size = state->parts[p].size;
+ if (!size)
+ continue;
+
+ from = state->parts[p].from;
+ if (from >= get_capacity(disk)) {
+ printk(KERN_WARNING
+ "%s: p%d start %llu is beyond EOD, ",
+ disk->disk_name, p, (unsigned long long) from);
+ if (disk_unlock_native_capacity(disk))
+ goto rescan;
+ continue;
+ }
+
+ if (from + size > get_capacity(disk)) {
+ printk(KERN_WARNING
+ "%s: p%d size %llu extends beyond EOD, ",
+ disk->disk_name, p, (unsigned long long) size);
+
+ if (disk_unlock_native_capacity(disk)) {
+ /* free state and restart */
+ goto rescan;
+ } else {
+ /*
+ * we can not ignore partitions of broken tables
+ * created by for example camera firmware, but
+ * we limit them to the end of the disk to avoid
+ * creating invalid block devices
+ */
+ size = get_capacity(disk) - from;
+ }
+ }
+
+ /*
+ * On a zoned block device, partitions should be aligned on the
+ * device zone size (i.e. zone boundary crossing not allowed).
+ * Otherwise, resetting the write pointer of the last zone of
+ * one partition may impact the following partition.
+ */
+ if (bdev_is_zoned(bdev) &&
+ !part_zone_aligned(disk, bdev, from, size)) {
+ printk(KERN_WARNING
+ "%s: p%d start %llu+%llu is not zone aligned\n",
+ disk->disk_name, p, (unsigned long long) from,
+ (unsigned long long) size);
+ continue;
+ }
+
+ part = add_partition(disk, p, from, size,
+ state->parts[p].flags,
+ &state->parts[p].info);
+ if (IS_ERR(part)) {
+ printk(KERN_ERR " %s: p%d could not be added: %ld\n",
+ disk->disk_name, p, -PTR_ERR(part));
+ continue;
+ }
+#ifdef CONFIG_BLK_DEV_MD
+ if (state->parts[p].flags & ADDPART_FLAG_RAID)
+ md_autodetect_dev(part_to_dev(part)->devt);
+#endif
+ }
+ free_partitions(state);
+ return 0;
+}
+
+int invalidate_partitions(struct gendisk *disk, struct block_device *bdev)
+{
+ int res;
+
+ if (!bdev->bd_invalidated)
+ return 0;
+
+ res = drop_partitions(disk, bdev);
+ if (res)
+ return res;
+
+ set_capacity(disk, 0);
+ check_disk_size_change(disk, bdev);
+ bdev->bd_invalidated = 0;
+ /* tell userspace that the media / partition table may have changed */
+ kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+
+ return 0;
+}
+
+unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
+{
+ struct address_space *mapping = bdev->bd_inode->i_mapping;
+ struct page *page;
+
+ page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_SHIFT-9)), NULL);
+ if (!IS_ERR(page)) {
+ if (PageError(page))
+ goto fail;
+ p->v = page;
+ return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << 9);
+fail:
+ put_page(page);
+ }
+ p->v = NULL;
+ return NULL;
+}
+
+EXPORT_SYMBOL(read_dev_sector);
diff --git a/src/kernel/linux/v4.14/block/partitions/Kconfig b/src/kernel/linux/v4.14/block/partitions/Kconfig
new file mode 100644
index 0000000..37b9710
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/Kconfig
@@ -0,0 +1,270 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Partition configuration
+#
+config PARTITION_ADVANCED
+ bool "Advanced partition selection"
+ help
+ Say Y here if you would like to use hard disks under Linux which
+ were partitioned under an operating system running on a different
+ architecture than your Linux system.
+
+ Note that the answer to this question won't directly affect the
+ kernel: saying N will just cause the configurator to skip all
+ the questions about foreign partitioning schemes.
+
+ If unsure, say N.
+
+config ACORN_PARTITION
+ bool "Acorn partition support" if PARTITION_ADVANCED
+ default y if ARCH_ACORN
+ help
+ Support hard disks partitioned under Acorn operating systems.
+
+config ACORN_PARTITION_CUMANA
+ bool "Cumana partition support" if PARTITION_ADVANCED
+ default y if ARCH_ACORN
+ depends on ACORN_PARTITION
+ help
+ Say Y here if you would like to use hard disks under Linux which
+ were partitioned using the Cumana interface on Acorn machines.
+
+config ACORN_PARTITION_EESOX
+ bool "EESOX partition support" if PARTITION_ADVANCED
+ default y if ARCH_ACORN
+ depends on ACORN_PARTITION
+
+config ACORN_PARTITION_ICS
+ bool "ICS partition support" if PARTITION_ADVANCED
+ default y if ARCH_ACORN
+ depends on ACORN_PARTITION
+ help
+ Say Y here if you would like to use hard disks under Linux which
+ were partitioned using the ICS interface on Acorn machines.
+
+config ACORN_PARTITION_ADFS
+ bool "Native filecore partition support" if PARTITION_ADVANCED
+ default y if ARCH_ACORN
+ depends on ACORN_PARTITION
+ help
+ The Acorn Disc Filing System is the standard file system of the
+ RiscOS operating system which runs on Acorn's ARM-based Risc PC
+ systems and the Acorn Archimedes range of machines. If you say
+ `Y' here, Linux will support disk partitions created under ADFS.
+
+config ACORN_PARTITION_POWERTEC
+ bool "PowerTec partition support" if PARTITION_ADVANCED
+ default y if ARCH_ACORN
+ depends on ACORN_PARTITION
+ help
+ Support reading partition tables created on Acorn machines using
+ the PowerTec SCSI drive.
+
+config ACORN_PARTITION_RISCIX
+ bool "RISCiX partition support" if PARTITION_ADVANCED
+ default y if ARCH_ACORN
+ depends on ACORN_PARTITION
+ help
+ Once upon a time, there was a native Unix port for the Acorn series
+ of machines called RISCiX. If you say 'Y' here, Linux will be able
+ to read disks partitioned under RISCiX.
+
+config AIX_PARTITION
+ bool "AIX basic partition table support" if PARTITION_ADVANCED
+ help
+ Say Y here if you would like to be able to read the hard disk
+ partition table format used by IBM or Motorola PowerPC machines
+ running AIX. AIX actually uses a Logical Volume Manager, where
+ "logical volumes" can be spread across one or multiple disks,
+ but this driver works only for the simple case of partitions which
+ are contiguous.
+ Otherwise, say N.
+
+config OSF_PARTITION
+ bool "Alpha OSF partition support" if PARTITION_ADVANCED
+ default y if ALPHA
+ help
+ Say Y here if you would like to use hard disks under Linux which
+ were partitioned on an Alpha machine.
+
+config AMIGA_PARTITION
+ bool "Amiga partition table support" if PARTITION_ADVANCED
+ default y if (AMIGA || AFFS_FS=y)
+ help
+ Say Y here if you would like to use hard disks under Linux which
+ were partitioned under AmigaOS.
+
+config ATARI_PARTITION
+ bool "Atari partition table support" if PARTITION_ADVANCED
+ default y if ATARI
+ help
+ Say Y here if you would like to use hard disks under Linux which
+ were partitioned under the Atari OS.
+
+config IBM_PARTITION
+ bool "IBM disk label and partition support"
+ depends on PARTITION_ADVANCED && S390
+ help
+ Say Y here if you would like to be able to read the hard disk
+ partition table format used by IBM DASD disks operating under CMS.
+ Otherwise, say N.
+
+config MAC_PARTITION
+ bool "Macintosh partition map support" if PARTITION_ADVANCED
+ default y if (MAC || PPC_PMAC)
+ help
+ Say Y here if you would like to use hard disks under Linux which
+ were partitioned on a Macintosh.
+
+config MSDOS_PARTITION
+ bool "PC BIOS (MSDOS partition tables) support" if PARTITION_ADVANCED
+ default y
+ help
+ Say Y here.
+
+config BSD_DISKLABEL
+ bool "BSD disklabel (FreeBSD partition tables) support"
+ depends on PARTITION_ADVANCED && MSDOS_PARTITION
+ help
+ FreeBSD uses its own hard disk partition scheme on your PC. It
+ requires only one entry in the primary partition table of your disk
+ and manages it similarly to DOS extended partitions, putting in its
+ first sector a new partition table in BSD disklabel format. Saying Y
+ here allows you to read these disklabels and further mount FreeBSD
+ partitions from within Linux if you have also said Y to "UFS
+ file system support", above. If you don't know what all this is
+ about, say N.
+
+config MINIX_SUBPARTITION
+ bool "Minix subpartition support"
+ depends on PARTITION_ADVANCED && MSDOS_PARTITION
+ help
+ Minix 2.0.0/2.0.2 subpartition table support for Linux.
+ Say Y here if you want to mount and use Minix 2.0.0/2.0.2
+ subpartitions.
+
+config SOLARIS_X86_PARTITION
+ bool "Solaris (x86) partition table support"
+ depends on PARTITION_ADVANCED && MSDOS_PARTITION
+ help
+ Like most systems, Solaris x86 uses its own hard disk partition
+ table format, incompatible with all others. Saying Y here allows you
+ to read these partition tables and further mount Solaris x86
+ partitions from within Linux if you have also said Y to "UFS
+ file system support", above.
+
+config UNIXWARE_DISKLABEL
+ bool "Unixware slices support"
+ depends on PARTITION_ADVANCED && MSDOS_PARTITION
+ ---help---
+ Like some systems, UnixWare uses its own slice table inside a
+ partition (VTOC - Virtual Table of Contents). Its format is
+ incompatible with all other OSes. Saying Y here allows you to read
+ VTOC and further mount UnixWare partitions read-only from within
+ Linux if you have also said Y to "UFS file system support" or
+ "System V and Coherent file system support", above.
+
+ This is mainly used to carry data from a UnixWare box to your
+ Linux box via a removable medium like magneto-optical, ZIP or
+ removable IDE drives. Note, however, that a good portable way to
+ transport files and directories between unixes (and even other
+ operating systems) is given by the tar program ("man tar" or
+ preferably "info tar").
+
+ If you don't know what all this is about, say N.
+
+config LDM_PARTITION
+ bool "Windows Logical Disk Manager (Dynamic Disk) support"
+ depends on PARTITION_ADVANCED
+ ---help---
+ Say Y here if you would like to use hard disks under Linux which
+ were partitioned using Windows 2000's/XP's or Vista's Logical Disk
+ Manager. They are also known as "Dynamic Disks".
+
+ Note this driver only supports Dynamic Disks with a protective MBR
+ label, i.e. DOS partition table. It does not support GPT labelled
+ Dynamic Disks yet as can be created with Vista.
+
+ Windows 2000 introduced the concept of Dynamic Disks to get around
+ the limitations of the PC's partitioning scheme. The Logical Disk
+ Manager allows the user to repartition a disk and create spanned,
+ mirrored, striped or RAID volumes, all without the need for
+ rebooting.
+
+ Normal partitions are now called Basic Disks under Windows 2000, XP,
+ and Vista.
+
+ For a fuller description read <file:Documentation/ldm.txt>.
+
+ If unsure, say N.
+
+config LDM_DEBUG
+ bool "Windows LDM extra logging"
+ depends on LDM_PARTITION
+ help
+ Say Y here if you would like LDM to log verbosely. This could be
+ helpful if the driver doesn't work as expected and you'd like to
+ report a bug.
+
+ If unsure, say N.
+
+config SGI_PARTITION
+ bool "SGI partition support" if PARTITION_ADVANCED
+ default y if DEFAULT_SGI_PARTITION
+ help
+ Say Y here if you would like to be able to read the hard disk
+ partition table format used by SGI machines.
+
+config ULTRIX_PARTITION
+ bool "Ultrix partition table support" if PARTITION_ADVANCED
+ default y if MACH_DECSTATION
+ help
+ Say Y here if you would like to be able to read the hard disk
+ partition table format used by DEC (now Compaq) Ultrix machines.
+ Otherwise, say N.
+
+config SUN_PARTITION
+ bool "Sun partition tables support" if PARTITION_ADVANCED
+ default y if (SPARC || SUN3 || SUN3X)
+ ---help---
+ Like most systems, SunOS uses its own hard disk partition table
+ format, incompatible with all others. Saying Y here allows you to
+ read these partition tables and further mount SunOS partitions from
+ within Linux if you have also said Y to "UFS file system support",
+ above. This is mainly used to carry data from a SPARC under SunOS to
+ your Linux box via a removable medium like magneto-optical or ZIP
+ drives; note however that a good portable way to transport files and
+ directories between unixes (and even other operating systems) is
+ given by the tar program ("man tar" or preferably "info tar"). If
+ you don't know what all this is about, say N.
+
+config KARMA_PARTITION
+ bool "Karma Partition support"
+ depends on PARTITION_ADVANCED
+ help
+ Say Y here if you would like to mount the Rio Karma MP3 player, as it
+ uses a proprietary partition table.
+
+config EFI_PARTITION
+ bool "EFI GUID Partition support" if PARTITION_ADVANCED
+ default y
+ select CRC32
+ help
+ Say Y here if you would like to use hard disks under Linux which
+ were partitioned using EFI GPT.
+
+config SYSV68_PARTITION
+ bool "SYSV68 partition table support" if PARTITION_ADVANCED
+ default y if VME
+ help
+ Say Y here if you would like to be able to read the hard disk
+ partition table format used by Motorola Delta machines (using
+ sysv68).
+ Otherwise, say N.
+
+config CMDLINE_PARTITION
+ bool "Command line partition support" if PARTITION_ADVANCED
+ select BLK_CMDLINE_PARSER
+ help
+ Say Y here if you want to read the partition table from bootargs.
+ The format for the command line is just like mtdparts.
diff --git a/src/kernel/linux/v4.14/block/partitions/Makefile b/src/kernel/linux/v4.14/block/partitions/Makefile
new file mode 100644
index 0000000..2f276b6
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/Makefile
@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+
+obj-$(CONFIG_BLOCK) := check.o
+
+obj-$(CONFIG_ACORN_PARTITION) += acorn.o
+obj-$(CONFIG_AMIGA_PARTITION) += amiga.o
+obj-$(CONFIG_ATARI_PARTITION) += atari.o
+obj-$(CONFIG_AIX_PARTITION) += aix.o
+obj-$(CONFIG_CMDLINE_PARTITION) += cmdline.o
+obj-$(CONFIG_MAC_PARTITION) += mac.o
+obj-$(CONFIG_LDM_PARTITION) += ldm.o
+obj-$(CONFIG_MSDOS_PARTITION) += msdos.o
+obj-$(CONFIG_OSF_PARTITION) += osf.o
+obj-$(CONFIG_SGI_PARTITION) += sgi.o
+obj-$(CONFIG_SUN_PARTITION) += sun.o
+obj-$(CONFIG_ULTRIX_PARTITION) += ultrix.o
+obj-$(CONFIG_IBM_PARTITION) += ibm.o
+obj-$(CONFIG_EFI_PARTITION) += efi.o
+obj-$(CONFIG_KARMA_PARTITION) += karma.o
+obj-$(CONFIG_SYSV68_PARTITION) += sysv68.o
diff --git a/src/kernel/linux/v4.14/block/partitions/acorn.c b/src/kernel/linux/v4.14/block/partitions/acorn.c
new file mode 100644
index 0000000..fbeb697
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/acorn.c
@@ -0,0 +1,556 @@
+/*
+ * linux/fs/partitions/acorn.c
+ *
+ * Copyright (c) 1996-2000 Russell King.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Scan ADFS partitions on hard disk drives. Unfortunately, there
+ * isn't a standard for partitioning drives on Acorn machines, so
+ * every single manufacturer of SCSI and IDE cards created their own
+ * method.
+ */
+#include <linux/buffer_head.h>
+#include <linux/adfs_fs.h>
+
+#include "check.h"
+#include "acorn.h"
+
+/*
+ * Partition types. (Oh for reusability)
+ */
+#define PARTITION_RISCIX_MFM 1
+#define PARTITION_RISCIX_SCSI 2
+#define PARTITION_LINUX 9
+
+#if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
+ defined(CONFIG_ACORN_PARTITION_ADFS)
+static struct adfs_discrecord *
+adfs_partition(struct parsed_partitions *state, char *name, char *data,
+ unsigned long first_sector, int slot)
+{
+ struct adfs_discrecord *dr;
+ unsigned int nr_sects;
+
+ if (adfs_checkbblk(data))
+ return NULL;
+
+ dr = (struct adfs_discrecord *)(data + 0x1c0);
+
+ if (dr->disc_size == 0 && dr->disc_size_high == 0)
+ return NULL;
+
+ nr_sects = (le32_to_cpu(dr->disc_size_high) << 23) |
+ (le32_to_cpu(dr->disc_size) >> 9);
+
+ if (name) {
+ strlcat(state->pp_buf, " [", PAGE_SIZE);
+ strlcat(state->pp_buf, name, PAGE_SIZE);
+ strlcat(state->pp_buf, "]", PAGE_SIZE);
+ }
+ put_partition(state, slot, first_sector, nr_sects);
+ return dr;
+}
+#endif
+
+#ifdef CONFIG_ACORN_PARTITION_RISCIX
+
+struct riscix_part {
+ __le32 start;
+ __le32 length;
+ __le32 one;
+ char name[16];
+};
+
+struct riscix_record {
+ __le32 magic;
+#define RISCIX_MAGIC cpu_to_le32(0x4a657320)
+ __le32 date;
+ struct riscix_part part[8];
+};
+
+#if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
+ defined(CONFIG_ACORN_PARTITION_ADFS)
+static int riscix_partition(struct parsed_partitions *state,
+ unsigned long first_sect, int slot,
+ unsigned long nr_sects)
+{
+ Sector sect;
+ struct riscix_record *rr;
+
+ rr = read_part_sector(state, first_sect, §);
+ if (!rr)
+ return -1;
+
+ strlcat(state->pp_buf, " [RISCiX]", PAGE_SIZE);
+
+
+ if (rr->magic == RISCIX_MAGIC) {
+ unsigned long size = nr_sects > 2 ? 2 : nr_sects;
+ int part;
+
+ strlcat(state->pp_buf, " <", PAGE_SIZE);
+
+ put_partition(state, slot++, first_sect, size);
+ for (part = 0; part < 8; part++) {
+ if (rr->part[part].one &&
+ memcmp(rr->part[part].name, "All\0", 4)) {
+ put_partition(state, slot++,
+ le32_to_cpu(rr->part[part].start),
+ le32_to_cpu(rr->part[part].length));
+ strlcat(state->pp_buf, "(", PAGE_SIZE);
+ strlcat(state->pp_buf, rr->part[part].name, PAGE_SIZE);
+ strlcat(state->pp_buf, ")", PAGE_SIZE);
+ }
+ }
+
+ strlcat(state->pp_buf, " >\n", PAGE_SIZE);
+ } else {
+ put_partition(state, slot++, first_sect, nr_sects);
+ }
+
+ put_dev_sector(sect);
+ return slot;
+}
+#endif
+#endif
+
+#define LINUX_NATIVE_MAGIC 0xdeafa1de
+#define LINUX_SWAP_MAGIC 0xdeafab1e
+
+struct linux_part {
+ __le32 magic;
+ __le32 start_sect;
+ __le32 nr_sects;
+};
+
+#if defined(CONFIG_ACORN_PARTITION_CUMANA) || \
+ defined(CONFIG_ACORN_PARTITION_ADFS)
+static int linux_partition(struct parsed_partitions *state,
+ unsigned long first_sect, int slot,
+ unsigned long nr_sects)
+{
+ Sector sect;
+ struct linux_part *linuxp;
+ unsigned long size = nr_sects > 2 ? 2 : nr_sects;
+
+ strlcat(state->pp_buf, " [Linux]", PAGE_SIZE);
+
+ put_partition(state, slot++, first_sect, size);
+
+ linuxp = read_part_sector(state, first_sect, §);
+ if (!linuxp)
+ return -1;
+
+ strlcat(state->pp_buf, " <", PAGE_SIZE);
+ while (linuxp->magic == cpu_to_le32(LINUX_NATIVE_MAGIC) ||
+ linuxp->magic == cpu_to_le32(LINUX_SWAP_MAGIC)) {
+ if (slot == state->limit)
+ break;
+ put_partition(state, slot++, first_sect +
+ le32_to_cpu(linuxp->start_sect),
+ le32_to_cpu(linuxp->nr_sects));
+ linuxp ++;
+ }
+ strlcat(state->pp_buf, " >", PAGE_SIZE);
+
+ put_dev_sector(sect);
+ return slot;
+}
+#endif
+
+#ifdef CONFIG_ACORN_PARTITION_CUMANA
+int adfspart_check_CUMANA(struct parsed_partitions *state)
+{
+ unsigned long first_sector = 0;
+ unsigned int start_blk = 0;
+ Sector sect;
+ unsigned char *data;
+ char *name = "CUMANA/ADFS";
+ int first = 1;
+ int slot = 1;
+
+ /*
+ * Try Cumana style partitions - sector 6 contains ADFS boot block
+ * with pointer to next 'drive'.
+ *
+ * There are unknowns in this code - is the 'cylinder number' of the
+ * next partition relative to the start of this one - I'm assuming
+ * it is.
+ *
+ * Also, which ID did Cumana use?
+ *
+ * This is totally unfinished, and will require more work to get it
+ * going. Hence it is totally untested.
+ */
+ do {
+ struct adfs_discrecord *dr;
+ unsigned int nr_sects;
+
+ data = read_part_sector(state, start_blk * 2 + 6, §);
+ if (!data)
+ return -1;
+
+ if (slot == state->limit)
+ break;
+
+ dr = adfs_partition(state, name, data, first_sector, slot++);
+ if (!dr)
+ break;
+
+ name = NULL;
+
+ nr_sects = (data[0x1fd] + (data[0x1fe] << 8)) *
+ (dr->heads + (dr->lowsector & 0x40 ? 1 : 0)) *
+ dr->secspertrack;
+
+ if (!nr_sects)
+ break;
+
+ first = 0;
+ first_sector += nr_sects;
+ start_blk += nr_sects >> (BLOCK_SIZE_BITS - 9);
+ nr_sects = 0; /* hmm - should be partition size */
+
+ switch (data[0x1fc] & 15) {
+ case 0: /* No partition / ADFS? */
+ break;
+
+#ifdef CONFIG_ACORN_PARTITION_RISCIX
+ case PARTITION_RISCIX_SCSI:
+ /* RISCiX - we don't know how to find the next one. */
+ slot = riscix_partition(state, first_sector, slot,
+ nr_sects);
+ break;
+#endif
+
+ case PARTITION_LINUX:
+ slot = linux_partition(state, first_sector, slot,
+ nr_sects);
+ break;
+ }
+ put_dev_sector(sect);
+ if (slot == -1)
+ return -1;
+ } while (1);
+ put_dev_sector(sect);
+ return first ? 0 : 1;
+}
+#endif
+
+#ifdef CONFIG_ACORN_PARTITION_ADFS
+/*
+ * Purpose: allocate ADFS partitions.
+ *
+ * Params : hd - pointer to gendisk structure to store partition info.
+ * dev - device number to access.
+ *
+ * Returns: -1 on error, 0 for no ADFS boot sector, 1 for ok.
+ *
+ * Alloc : hda = whole drive
+ * hda1 = ADFS partition on first drive.
+ * hda2 = non-ADFS partition.
+ */
+int adfspart_check_ADFS(struct parsed_partitions *state)
+{
+ unsigned long start_sect, nr_sects, sectscyl, heads;
+ Sector sect;
+ unsigned char *data;
+ struct adfs_discrecord *dr;
+ unsigned char id;
+ int slot = 1;
+
+ data = read_part_sector(state, 6, §);
+ if (!data)
+ return -1;
+
+ dr = adfs_partition(state, "ADFS", data, 0, slot++);
+ if (!dr) {
+ put_dev_sector(sect);
+ return 0;
+ }
+
+ heads = dr->heads + ((dr->lowsector >> 6) & 1);
+ sectscyl = dr->secspertrack * heads;
+ start_sect = ((data[0x1fe] << 8) + data[0x1fd]) * sectscyl;
+ id = data[0x1fc] & 15;
+ put_dev_sector(sect);
+
+ /*
+ * Work out start of non-adfs partition.
+ */
+ nr_sects = (state->bdev->bd_inode->i_size >> 9) - start_sect;
+
+ if (start_sect) {
+ switch (id) {
+#ifdef CONFIG_ACORN_PARTITION_RISCIX
+ case PARTITION_RISCIX_SCSI:
+ case PARTITION_RISCIX_MFM:
+ slot = riscix_partition(state, start_sect, slot,
+ nr_sects);
+ break;
+#endif
+
+ case PARTITION_LINUX:
+ slot = linux_partition(state, start_sect, slot,
+ nr_sects);
+ break;
+ }
+ }
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ return 1;
+}
+#endif
+
+#ifdef CONFIG_ACORN_PARTITION_ICS
+
+struct ics_part {
+ __le32 start;
+ __le32 size;
+};
+
+static int adfspart_check_ICSLinux(struct parsed_partitions *state,
+ unsigned long block)
+{
+ Sector sect;
+ unsigned char *data = read_part_sector(state, block, §);
+ int result = 0;
+
+ if (data) {
+ if (memcmp(data, "LinuxPart", 9) == 0)
+ result = 1;
+ put_dev_sector(sect);
+ }
+
+ return result;
+}
+
+/*
+ * Check for a valid ICS partition using the checksum.
+ */
+static inline int valid_ics_sector(const unsigned char *data)
+{
+ unsigned long sum;
+ int i;
+
+ for (i = 0, sum = 0x50617274; i < 508; i++)
+ sum += data[i];
+
+ sum -= le32_to_cpu(*(__le32 *)(&data[508]));
+
+ return sum == 0;
+}
+
+/*
+ * Purpose: allocate ICS partitions.
+ * Params : hd - pointer to gendisk structure to store partition info.
+ * dev - device number to access.
+ * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
+ * Alloc : hda = whole drive
+ * hda1 = ADFS partition 0 on first drive.
+ * hda2 = ADFS partition 1 on first drive.
+ * ..etc..
+ */
+int adfspart_check_ICS(struct parsed_partitions *state)
+{
+ const unsigned char *data;
+ const struct ics_part *p;
+ int slot;
+ Sector sect;
+
+ /*
+ * Try ICS style partitions - sector 0 contains partition info.
+ */
+ data = read_part_sector(state, 0, §);
+ if (!data)
+ return -1;
+
+ if (!valid_ics_sector(data)) {
+ put_dev_sector(sect);
+ return 0;
+ }
+
+ strlcat(state->pp_buf, " [ICS]", PAGE_SIZE);
+
+ for (slot = 1, p = (const struct ics_part *)data; p->size; p++) {
+ u32 start = le32_to_cpu(p->start);
+ s32 size = le32_to_cpu(p->size); /* yes, it's signed. */
+
+ if (slot == state->limit)
+ break;
+
+ /*
+ * Negative sizes tell the RISC OS ICS driver to ignore
+ * this partition - in effect it says that this does not
+ * contain an ADFS filesystem.
+ */
+ if (size < 0) {
+ size = -size;
+
+ /*
+ * Our own extension - We use the first sector
+ * of the partition to identify what type this
+ * partition is. We must not make this visible
+ * to the filesystem.
+ */
+ if (size > 1 && adfspart_check_ICSLinux(state, start)) {
+ start += 1;
+ size -= 1;
+ }
+ }
+
+ if (size)
+ put_partition(state, slot++, start, size);
+ }
+
+ put_dev_sector(sect);
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ return 1;
+}
+#endif
+
+#ifdef CONFIG_ACORN_PARTITION_POWERTEC
+struct ptec_part {
+ __le32 unused1;
+ __le32 unused2;
+ __le32 start;
+ __le32 size;
+ __le32 unused5;
+ char type[8];
+};
+
+static inline int valid_ptec_sector(const unsigned char *data)
+{
+ unsigned char checksum = 0x2a;
+ int i;
+
+ /*
+ * If it looks like a PC/BIOS partition, then it
+ * probably isn't PowerTec.
+ */
+ if (data[510] == 0x55 && data[511] == 0xaa)
+ return 0;
+
+ for (i = 0; i < 511; i++)
+ checksum += data[i];
+
+ return checksum == data[511];
+}
+
+/*
+ * Purpose: allocate ICS partitions.
+ * Params : hd - pointer to gendisk structure to store partition info.
+ * dev - device number to access.
+ * Returns: -1 on error, 0 for no ICS table, 1 for partitions ok.
+ * Alloc : hda = whole drive
+ * hda1 = ADFS partition 0 on first drive.
+ * hda2 = ADFS partition 1 on first drive.
+ * ..etc..
+ */
+int adfspart_check_POWERTEC(struct parsed_partitions *state)
+{
+ Sector sect;
+ const unsigned char *data;
+ const struct ptec_part *p;
+ int slot = 1;
+ int i;
+
+ data = read_part_sector(state, 0, §);
+ if (!data)
+ return -1;
+
+ if (!valid_ptec_sector(data)) {
+ put_dev_sector(sect);
+ return 0;
+ }
+
+ strlcat(state->pp_buf, " [POWERTEC]", PAGE_SIZE);
+
+ for (i = 0, p = (const struct ptec_part *)data; i < 12; i++, p++) {
+ u32 start = le32_to_cpu(p->start);
+ u32 size = le32_to_cpu(p->size);
+
+ if (size)
+ put_partition(state, slot++, start, size);
+ }
+
+ put_dev_sector(sect);
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ return 1;
+}
+#endif
+
+#ifdef CONFIG_ACORN_PARTITION_EESOX
+struct eesox_part {
+ char magic[6];
+ char name[10];
+ __le32 start;
+ __le32 unused6;
+ __le32 unused7;
+ __le32 unused8;
+};
+
+/*
+ * Guess who created this format?
+ */
+static const char eesox_name[] = {
+ 'N', 'e', 'i', 'l', ' ',
+ 'C', 'r', 'i', 't', 'c', 'h', 'e', 'l', 'l', ' ', ' '
+};
+
+/*
+ * EESOX SCSI partition format.
+ *
+ * This is a goddamned awful partition format. We don't seem to store
+ * the size of the partition in this table, only the start addresses.
+ *
+ * There are two possibilities where the size comes from:
+ * 1. The individual ADFS boot block entries that are placed on the disk.
+ * 2. The start address of the next entry.
+ */
+int adfspart_check_EESOX(struct parsed_partitions *state)
+{
+ Sector sect;
+ const unsigned char *data;
+ unsigned char buffer[256];
+ struct eesox_part *p;
+ sector_t start = 0;
+ int i, slot = 1;
+
+ data = read_part_sector(state, 7, §);
+ if (!data)
+ return -1;
+
+ /*
+ * "Decrypt" the partition table. God knows why...
+ */
+ for (i = 0; i < 256; i++)
+ buffer[i] = data[i] ^ eesox_name[i & 15];
+
+ put_dev_sector(sect);
+
+ for (i = 0, p = (struct eesox_part *)buffer; i < 8; i++, p++) {
+ sector_t next;
+
+ if (memcmp(p->magic, "Eesox", 6))
+ break;
+
+ next = le32_to_cpu(p->start);
+ if (i)
+ put_partition(state, slot++, start, next - start);
+ start = next;
+ }
+
+ if (i != 0) {
+ sector_t size;
+
+ size = get_capacity(state->bdev->bd_disk);
+ put_partition(state, slot++, start, size - start);
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ }
+
+ return i ? 1 : 0;
+}
+#endif
diff --git a/src/kernel/linux/v4.14/block/partitions/acorn.h b/src/kernel/linux/v4.14/block/partitions/acorn.h
new file mode 100644
index 0000000..67b0660
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/acorn.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/fs/partitions/acorn.h
+ *
+ * Copyright (C) 1996-2001 Russell King.
+ *
+ * I _hate_ this partitioning mess - why can't we have one defined
+ * format, and everyone stick to it?
+ */
+
+int adfspart_check_CUMANA(struct parsed_partitions *state);
+int adfspart_check_ADFS(struct parsed_partitions *state);
+int adfspart_check_ICS(struct parsed_partitions *state);
+int adfspart_check_POWERTEC(struct parsed_partitions *state);
+int adfspart_check_EESOX(struct parsed_partitions *state);
diff --git a/src/kernel/linux/v4.14/block/partitions/aix.c b/src/kernel/linux/v4.14/block/partitions/aix.c
new file mode 100644
index 0000000..903f3ed
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/aix.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/aix.c
+ *
+ * Copyright (C) 2012-2013 Philippe De Muyter <phdm@macqel.be>
+ */
+
+#include "check.h"
+#include "aix.h"
+
+struct lvm_rec {
+ char lvm_id[4]; /* "_LVM" */
+ char reserved4[16];
+ __be32 lvmarea_len;
+ __be32 vgda_len;
+ __be32 vgda_psn[2];
+ char reserved36[10];
+ __be16 pp_size; /* log2(pp_size) */
+ char reserved46[12];
+ __be16 version;
+ };
+
+struct vgda {
+ __be32 secs;
+ __be32 usec;
+ char reserved8[16];
+ __be16 numlvs;
+ __be16 maxlvs;
+ __be16 pp_size;
+ __be16 numpvs;
+ __be16 total_vgdas;
+ __be16 vgda_size;
+ };
+
+struct lvd {
+ __be16 lv_ix;
+ __be16 res2;
+ __be16 res4;
+ __be16 maxsize;
+ __be16 lv_state;
+ __be16 mirror;
+ __be16 mirror_policy;
+ __be16 num_lps;
+ __be16 res10[8];
+ };
+
+struct lvname {
+ char name[64];
+ };
+
+struct ppe {
+ __be16 lv_ix;
+ unsigned short res2;
+ unsigned short res4;
+ __be16 lp_ix;
+ unsigned short res8[12];
+ };
+
+struct pvd {
+ char reserved0[16];
+ __be16 pp_count;
+ char reserved18[2];
+ __be32 psn_part1;
+ char reserved24[8];
+ struct ppe ppe[1016];
+ };
+
+#define LVM_MAXLVS 256
+
+/**
+ * last_lba(): return number of last logical block of device
+ * @bdev: block device
+ *
+ * Description: Returns last LBA value on success, 0 on error.
+ * This is stored (by sd and ide-geometry) in
+ * the part[0] entry for this disk, and is the number of
+ * physical sectors available on the disk.
+ */
+static u64 last_lba(struct block_device *bdev)
+{
+ if (!bdev || !bdev->bd_inode)
+ return 0;
+ return (bdev->bd_inode->i_size >> 9) - 1ULL;
+}
+
+/**
+ * read_lba(): Read bytes from disk, starting at given LBA
+ * @state
+ * @lba
+ * @buffer
+ * @count
+ *
+ * Description: Reads @count bytes from @state->bdev into @buffer.
+ * Returns number of bytes read on success, 0 on error.
+ */
+static size_t read_lba(struct parsed_partitions *state, u64 lba, u8 *buffer,
+ size_t count)
+{
+ size_t totalreadcount = 0;
+
+ if (!buffer || lba + count / 512 > last_lba(state->bdev))
+ return 0;
+
+ while (count) {
+ int copied = 512;
+ Sector sect;
+ unsigned char *data = read_part_sector(state, lba++, §);
+ if (!data)
+ break;
+ if (copied > count)
+ copied = count;
+ memcpy(buffer, data, copied);
+ put_dev_sector(sect);
+ buffer += copied;
+ totalreadcount += copied;
+ count -= copied;
+ }
+ return totalreadcount;
+}
+
+/**
+ * alloc_pvd(): reads physical volume descriptor
+ * @state
+ * @lba
+ *
+ * Description: Returns pvd on success, NULL on error.
+ * Allocates space for pvd and fill it with disk blocks at @lba
+ * Notes: remember to free pvd when you're done!
+ */
+static struct pvd *alloc_pvd(struct parsed_partitions *state, u32 lba)
+{
+ size_t count = sizeof(struct pvd);
+ struct pvd *p;
+
+ p = kmalloc(count, GFP_KERNEL);
+ if (!p)
+ return NULL;
+
+ if (read_lba(state, lba, (u8 *) p, count) < count) {
+ kfree(p);
+ return NULL;
+ }
+ return p;
+}
+
+/**
+ * alloc_lvn(): reads logical volume names
+ * @state
+ * @lba
+ *
+ * Description: Returns lvn on success, NULL on error.
+ * Allocates space for lvn and fill it with disk blocks at @lba
+ * Notes: remember to free lvn when you're done!
+ */
+static struct lvname *alloc_lvn(struct parsed_partitions *state, u32 lba)
+{
+ size_t count = sizeof(struct lvname) * LVM_MAXLVS;
+ struct lvname *p;
+
+ p = kmalloc(count, GFP_KERNEL);
+ if (!p)
+ return NULL;
+
+ if (read_lba(state, lba, (u8 *) p, count) < count) {
+ kfree(p);
+ return NULL;
+ }
+ return p;
+}
+
+int aix_partition(struct parsed_partitions *state)
+{
+ int ret = 0;
+ Sector sect;
+ unsigned char *d;
+ u32 pp_bytes_size;
+ u32 pp_blocks_size = 0;
+ u32 vgda_sector = 0;
+ u32 vgda_len = 0;
+ int numlvs = 0;
+ struct pvd *pvd = NULL;
+ struct lv_info {
+ unsigned short pps_per_lv;
+ unsigned short pps_found;
+ unsigned char lv_is_contiguous;
+ } *lvip;
+ struct lvname *n = NULL;
+
+ d = read_part_sector(state, 7, §);
+ if (d) {
+ struct lvm_rec *p = (struct lvm_rec *)d;
+ u16 lvm_version = be16_to_cpu(p->version);
+ char tmp[64];
+
+ if (lvm_version == 1) {
+ int pp_size_log2 = be16_to_cpu(p->pp_size);
+
+ pp_bytes_size = 1 << pp_size_log2;
+ pp_blocks_size = pp_bytes_size / 512;
+ snprintf(tmp, sizeof(tmp),
+ " AIX LVM header version %u found\n",
+ lvm_version);
+ vgda_len = be32_to_cpu(p->vgda_len);
+ vgda_sector = be32_to_cpu(p->vgda_psn[0]);
+ } else {
+ snprintf(tmp, sizeof(tmp),
+ " unsupported AIX LVM version %d found\n",
+ lvm_version);
+ }
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ put_dev_sector(sect);
+ }
+ if (vgda_sector && (d = read_part_sector(state, vgda_sector, §))) {
+ struct vgda *p = (struct vgda *)d;
+
+ numlvs = be16_to_cpu(p->numlvs);
+ put_dev_sector(sect);
+ }
+ lvip = kcalloc(state->limit, sizeof(struct lv_info), GFP_KERNEL);
+ if (!lvip)
+ return 0;
+ if (numlvs && (d = read_part_sector(state, vgda_sector + 1, §))) {
+ struct lvd *p = (struct lvd *)d;
+ int i;
+
+ n = alloc_lvn(state, vgda_sector + vgda_len - 33);
+ if (n) {
+ int foundlvs = 0;
+
+ for (i = 0; foundlvs < numlvs && i < state->limit; i += 1) {
+ lvip[i].pps_per_lv = be16_to_cpu(p[i].num_lps);
+ if (lvip[i].pps_per_lv)
+ foundlvs += 1;
+ }
+ /* pvd loops depend on n[].name and lvip[].pps_per_lv */
+ pvd = alloc_pvd(state, vgda_sector + 17);
+ }
+ put_dev_sector(sect);
+ }
+ if (pvd) {
+ int numpps = be16_to_cpu(pvd->pp_count);
+ int psn_part1 = be32_to_cpu(pvd->psn_part1);
+ int i;
+ int cur_lv_ix = -1;
+ int next_lp_ix = 1;
+ int lp_ix;
+
+ for (i = 0; i < numpps; i += 1) {
+ struct ppe *p = pvd->ppe + i;
+ unsigned int lv_ix;
+
+ lp_ix = be16_to_cpu(p->lp_ix);
+ if (!lp_ix) {
+ next_lp_ix = 1;
+ continue;
+ }
+ lv_ix = be16_to_cpu(p->lv_ix) - 1;
+ if (lv_ix >= state->limit) {
+ cur_lv_ix = -1;
+ continue;
+ }
+ lvip[lv_ix].pps_found += 1;
+ if (lp_ix == 1) {
+ cur_lv_ix = lv_ix;
+ next_lp_ix = 1;
+ } else if (lv_ix != cur_lv_ix || lp_ix != next_lp_ix) {
+ next_lp_ix = 1;
+ continue;
+ }
+ if (lp_ix == lvip[lv_ix].pps_per_lv) {
+ char tmp[70];
+
+ put_partition(state, lv_ix + 1,
+ (i + 1 - lp_ix) * pp_blocks_size + psn_part1,
+ lvip[lv_ix].pps_per_lv * pp_blocks_size);
+ snprintf(tmp, sizeof(tmp), " <%s>\n",
+ n[lv_ix].name);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ lvip[lv_ix].lv_is_contiguous = 1;
+ ret = 1;
+ next_lp_ix = 1;
+ } else
+ next_lp_ix += 1;
+ }
+ for (i = 0; i < state->limit; i += 1)
+ if (lvip[i].pps_found && !lvip[i].lv_is_contiguous) {
+ char tmp[sizeof(n[i].name) + 1]; // null char
+
+ snprintf(tmp, sizeof(tmp), "%s", n[i].name);
+ pr_warn("partition %s (%u pp's found) is "
+ "not contiguous\n",
+ tmp, lvip[i].pps_found);
+ }
+ kfree(pvd);
+ }
+ kfree(n);
+ kfree(lvip);
+ return ret;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/aix.h b/src/kernel/linux/v4.14/block/partitions/aix.h
new file mode 100644
index 0000000..e0c66a9
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/aix.h
@@ -0,0 +1 @@
+extern int aix_partition(struct parsed_partitions *state);
diff --git a/src/kernel/linux/v4.14/block/partitions/amiga.c b/src/kernel/linux/v4.14/block/partitions/amiga.c
new file mode 100644
index 0000000..5609366
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/amiga.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/amiga.c
+ *
+ * Code extracted from drivers/block/genhd.c
+ *
+ * Copyright (C) 1991-1998 Linus Torvalds
+ * Re-organised Feb 1998 Russell King
+ */
+
+#define pr_fmt(fmt) fmt
+
+#include <linux/types.h>
+#include <linux/affs_hardblocks.h>
+
+#include "check.h"
+#include "amiga.h"
+
+static __inline__ u32
+checksum_block(__be32 *m, int size)
+{
+ u32 sum = 0;
+
+ while (size--)
+ sum += be32_to_cpu(*m++);
+ return sum;
+}
+
+int amiga_partition(struct parsed_partitions *state)
+{
+ Sector sect;
+ unsigned char *data;
+ struct RigidDiskBlock *rdb;
+ struct PartitionBlock *pb;
+ int start_sect, nr_sects, blk, part, res = 0;
+ int blksize = 1; /* Multiplier for disk block size */
+ int slot = 1;
+ char b[BDEVNAME_SIZE];
+
+ for (blk = 0; ; blk++, put_dev_sector(sect)) {
+ if (blk == RDB_ALLOCATION_LIMIT)
+ goto rdb_done;
+ data = read_part_sector(state, blk, §);
+ if (!data) {
+ if (warn_no_part)
+ pr_err("Dev %s: unable to read RDB block %d\n",
+ bdevname(state->bdev, b), blk);
+ res = -1;
+ goto rdb_done;
+ }
+ if (*(__be32 *)data != cpu_to_be32(IDNAME_RIGIDDISK))
+ continue;
+
+ rdb = (struct RigidDiskBlock *)data;
+ if (checksum_block((__be32 *)data, be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F) == 0)
+ break;
+ /* Try again with 0xdc..0xdf zeroed, Windows might have
+ * trashed it.
+ */
+ *(__be32 *)(data+0xdc) = 0;
+ if (checksum_block((__be32 *)data,
+ be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
+ pr_err("Trashed word at 0xd0 in block %d ignored in checksum calculation\n",
+ blk);
+ break;
+ }
+
+ pr_err("Dev %s: RDB in block %d has bad checksum\n",
+ bdevname(state->bdev, b), blk);
+ }
+
+ /* blksize is blocks per 512 byte standard block */
+ blksize = be32_to_cpu( rdb->rdb_BlockBytes ) / 512;
+
+ {
+ char tmp[7 + 10 + 1 + 1];
+
+ /* Be more informative */
+ snprintf(tmp, sizeof(tmp), " RDSK (%d)", blksize * 512);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ }
+ blk = be32_to_cpu(rdb->rdb_PartitionList);
+ put_dev_sector(sect);
+ for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
+ blk *= blksize; /* Read in terms partition table understands */
+ data = read_part_sector(state, blk, §);
+ if (!data) {
+ if (warn_no_part)
+ pr_err("Dev %s: unable to read partition block %d\n",
+ bdevname(state->bdev, b), blk);
+ res = -1;
+ goto rdb_done;
+ }
+ pb = (struct PartitionBlock *)data;
+ blk = be32_to_cpu(pb->pb_Next);
+ if (pb->pb_ID != cpu_to_be32(IDNAME_PARTITION))
+ continue;
+ if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
+ continue;
+
+ /* Tell Kernel about it */
+
+ nr_sects = (be32_to_cpu(pb->pb_Environment[10]) + 1 -
+ be32_to_cpu(pb->pb_Environment[9])) *
+ be32_to_cpu(pb->pb_Environment[3]) *
+ be32_to_cpu(pb->pb_Environment[5]) *
+ blksize;
+ if (!nr_sects)
+ continue;
+ start_sect = be32_to_cpu(pb->pb_Environment[9]) *
+ be32_to_cpu(pb->pb_Environment[3]) *
+ be32_to_cpu(pb->pb_Environment[5]) *
+ blksize;
+ put_partition(state,slot++,start_sect,nr_sects);
+ {
+ /* Be even more informative to aid mounting */
+ char dostype[4];
+ char tmp[42];
+
+ __be32 *dt = (__be32 *)dostype;
+ *dt = pb->pb_Environment[16];
+ if (dostype[3] < ' ')
+ snprintf(tmp, sizeof(tmp), " (%c%c%c^%c)",
+ dostype[0], dostype[1],
+ dostype[2], dostype[3] + '@' );
+ else
+ snprintf(tmp, sizeof(tmp), " (%c%c%c%c)",
+ dostype[0], dostype[1],
+ dostype[2], dostype[3]);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ snprintf(tmp, sizeof(tmp), "(res %d spb %d)",
+ be32_to_cpu(pb->pb_Environment[6]),
+ be32_to_cpu(pb->pb_Environment[4]));
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ }
+ res = 1;
+ }
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+
+rdb_done:
+ return res;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/amiga.h b/src/kernel/linux/v4.14/block/partitions/amiga.h
new file mode 100644
index 0000000..d094585
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/amiga.h
@@ -0,0 +1,6 @@
+/*
+ * fs/partitions/amiga.h
+ */
+
+int amiga_partition(struct parsed_partitions *state);
+
diff --git a/src/kernel/linux/v4.14/block/partitions/atari.c b/src/kernel/linux/v4.14/block/partitions/atari.c
new file mode 100644
index 0000000..2305840
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/atari.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/atari.c
+ *
+ * Code extracted from drivers/block/genhd.c
+ *
+ * Copyright (C) 1991-1998 Linus Torvalds
+ * Re-organised Feb 1998 Russell King
+ */
+
+#include <linux/ctype.h>
+#include "check.h"
+#include "atari.h"
+
+/* ++guenther: this should be settable by the user ("make config")?.
+ */
+#define ICD_PARTS
+
+/* check if a partition entry looks valid -- Atari format is assumed if at
+ least one of the primary entries is ok this way */
+#define VALID_PARTITION(pi,hdsiz) \
+ (((pi)->flg & 1) && \
+ isalnum((pi)->id[0]) && isalnum((pi)->id[1]) && isalnum((pi)->id[2]) && \
+ be32_to_cpu((pi)->st) <= (hdsiz) && \
+ be32_to_cpu((pi)->st) + be32_to_cpu((pi)->siz) <= (hdsiz))
+
+static inline int OK_id(char *s)
+{
+ return memcmp (s, "GEM", 3) == 0 || memcmp (s, "BGM", 3) == 0 ||
+ memcmp (s, "LNX", 3) == 0 || memcmp (s, "SWP", 3) == 0 ||
+ memcmp (s, "RAW", 3) == 0 ;
+}
+
+int atari_partition(struct parsed_partitions *state)
+{
+ Sector sect;
+ struct rootsector *rs;
+ struct partition_info *pi;
+ u32 extensect;
+ u32 hd_size;
+ int slot;
+#ifdef ICD_PARTS
+ int part_fmt = 0; /* 0:unknown, 1:AHDI, 2:ICD/Supra */
+#endif
+
+ /*
+ * ATARI partition scheme supports 512 lba only. If this is not
+ * the case, bail early to avoid miscalculating hd_size.
+ */
+ if (bdev_logical_block_size(state->bdev) != 512)
+ return 0;
+
+ rs = read_part_sector(state, 0, §);
+ if (!rs)
+ return -1;
+
+ /* Verify this is an Atari rootsector: */
+ hd_size = state->bdev->bd_inode->i_size >> 9;
+ if (!VALID_PARTITION(&rs->part[0], hd_size) &&
+ !VALID_PARTITION(&rs->part[1], hd_size) &&
+ !VALID_PARTITION(&rs->part[2], hd_size) &&
+ !VALID_PARTITION(&rs->part[3], hd_size)) {
+ /*
+ * if there's no valid primary partition, assume that no Atari
+ * format partition table (there's no reliable magic or the like
+ * :-()
+ */
+ put_dev_sector(sect);
+ return 0;
+ }
+
+ pi = &rs->part[0];
+ strlcat(state->pp_buf, " AHDI", PAGE_SIZE);
+ for (slot = 1; pi < &rs->part[4] && slot < state->limit; slot++, pi++) {
+ struct rootsector *xrs;
+ Sector sect2;
+ ulong partsect;
+
+ if ( !(pi->flg & 1) )
+ continue;
+ /* active partition */
+ if (memcmp (pi->id, "XGM", 3) != 0) {
+ /* we don't care about other id's */
+ put_partition (state, slot, be32_to_cpu(pi->st),
+ be32_to_cpu(pi->siz));
+ continue;
+ }
+ /* extension partition */
+#ifdef ICD_PARTS
+ part_fmt = 1;
+#endif
+ strlcat(state->pp_buf, " XGM<", PAGE_SIZE);
+ partsect = extensect = be32_to_cpu(pi->st);
+ while (1) {
+ xrs = read_part_sector(state, partsect, §2);
+ if (!xrs) {
+ printk (" block %ld read failed\n", partsect);
+ put_dev_sector(sect);
+ return -1;
+ }
+
+ /* ++roman: sanity check: bit 0 of flg field must be set */
+ if (!(xrs->part[0].flg & 1)) {
+ printk( "\nFirst sub-partition in extended partition is not valid!\n" );
+ put_dev_sector(sect2);
+ break;
+ }
+
+ put_partition(state, slot,
+ partsect + be32_to_cpu(xrs->part[0].st),
+ be32_to_cpu(xrs->part[0].siz));
+
+ if (!(xrs->part[1].flg & 1)) {
+ /* end of linked partition list */
+ put_dev_sector(sect2);
+ break;
+ }
+ if (memcmp( xrs->part[1].id, "XGM", 3 ) != 0) {
+ printk("\nID of extended partition is not XGM!\n");
+ put_dev_sector(sect2);
+ break;
+ }
+
+ partsect = be32_to_cpu(xrs->part[1].st) + extensect;
+ put_dev_sector(sect2);
+ if (++slot == state->limit) {
+ printk( "\nMaximum number of partitions reached!\n" );
+ break;
+ }
+ }
+ strlcat(state->pp_buf, " >", PAGE_SIZE);
+ }
+#ifdef ICD_PARTS
+ if ( part_fmt!=1 ) { /* no extended partitions -> test ICD-format */
+ pi = &rs->icdpart[0];
+ /* sanity check: no ICD format if first partition invalid */
+ if (OK_id(pi->id)) {
+ strlcat(state->pp_buf, " ICD<", PAGE_SIZE);
+ for (; pi < &rs->icdpart[8] && slot < state->limit; slot++, pi++) {
+ /* accept only GEM,BGM,RAW,LNX,SWP partitions */
+ if (!((pi->flg & 1) && OK_id(pi->id)))
+ continue;
+ part_fmt = 2;
+ put_partition (state, slot,
+ be32_to_cpu(pi->st),
+ be32_to_cpu(pi->siz));
+ }
+ strlcat(state->pp_buf, " >", PAGE_SIZE);
+ }
+ }
+#endif
+ put_dev_sector(sect);
+
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+
+ return 1;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/atari.h b/src/kernel/linux/v4.14/block/partitions/atari.h
new file mode 100644
index 0000000..01c2b94
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/atari.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * fs/partitions/atari.h
+ * Moved by Russell King from:
+ *
+ * linux/include/linux/atari_rootsec.h
+ * definitions for Atari Rootsector layout
+ * by Andreas Schwab (schwab@ls5.informatik.uni-dortmund.de)
+ *
+ * modified for ICD/Supra partitioning scheme restricted to at most 12
+ * partitions
+ * by Guenther Kelleter (guenther@pool.informatik.rwth-aachen.de)
+ */
+
+#include <linux/compiler.h>
+
+struct partition_info
+{
+ u8 flg; /* bit 0: active; bit 7: bootable */
+ char id[3]; /* "GEM", "BGM", "XGM", or other */
+ __be32 st; /* start of partition */
+ __be32 siz; /* length of partition */
+};
+
+struct rootsector
+{
+ char unused[0x156]; /* room for boot code */
+ struct partition_info icdpart[8]; /* info for ICD-partitions 5..12 */
+ char unused2[0xc];
+ u32 hd_siz; /* size of disk in blocks */
+ struct partition_info part[4];
+ u32 bsl_st; /* start of bad sector list */
+ u32 bsl_cnt; /* length of bad sector list */
+ u16 checksum; /* checksum for bootable disks */
+} __packed;
+
+int atari_partition(struct parsed_partitions *state);
diff --git a/src/kernel/linux/v4.14/block/partitions/check.c b/src/kernel/linux/v4.14/block/partitions/check.c
new file mode 100644
index 0000000..720145c
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/check.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/check.c
+ *
+ * Code extracted from drivers/block/genhd.c
+ * Copyright (C) 1991-1998 Linus Torvalds
+ * Re-organised Feb 1998 Russell King
+ *
+ * We now have independent partition support from the
+ * block drivers, which allows all the partition code to
+ * be grouped in one location, and it to be mostly self
+ * contained.
+ *
+ * Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
+ */
+
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/ctype.h>
+#include <linux/genhd.h>
+
+#include "check.h"
+
+#include "acorn.h"
+#include "amiga.h"
+#include "atari.h"
+#include "ldm.h"
+#include "mac.h"
+#include "msdos.h"
+#include "osf.h"
+#include "sgi.h"
+#include "sun.h"
+#include "ibm.h"
+#include "ultrix.h"
+#include "efi.h"
+#include "karma.h"
+#include "sysv68.h"
+#include "cmdline.h"
+
+int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
+
+static int (*check_part[])(struct parsed_partitions *) = {
+ /*
+ * Probe partition formats with tables at disk address 0
+ * that also have an ADFS boot block at 0xdc0.
+ */
+#ifdef CONFIG_ACORN_PARTITION_ICS
+ adfspart_check_ICS,
+#endif
+#ifdef CONFIG_ACORN_PARTITION_POWERTEC
+ adfspart_check_POWERTEC,
+#endif
+#ifdef CONFIG_ACORN_PARTITION_EESOX
+ adfspart_check_EESOX,
+#endif
+
+ /*
+ * Now move on to formats that only have partition info at
+ * disk address 0xdc0. Since these may also have stale
+ * PC/BIOS partition tables, they need to come before
+ * the msdos entry.
+ */
+#ifdef CONFIG_ACORN_PARTITION_CUMANA
+ adfspart_check_CUMANA,
+#endif
+#ifdef CONFIG_ACORN_PARTITION_ADFS
+ adfspart_check_ADFS,
+#endif
+
+#ifdef CONFIG_CMDLINE_PARTITION
+ cmdline_partition,
+#endif
+#ifdef CONFIG_EFI_PARTITION
+ efi_partition, /* this must come before msdos */
+#endif
+#ifdef CONFIG_SGI_PARTITION
+ sgi_partition,
+#endif
+#ifdef CONFIG_LDM_PARTITION
+ ldm_partition, /* this must come before msdos */
+#endif
+#ifdef CONFIG_MSDOS_PARTITION
+ msdos_partition,
+#endif
+#ifdef CONFIG_OSF_PARTITION
+ osf_partition,
+#endif
+#ifdef CONFIG_SUN_PARTITION
+ sun_partition,
+#endif
+#ifdef CONFIG_AMIGA_PARTITION
+ amiga_partition,
+#endif
+#ifdef CONFIG_ATARI_PARTITION
+ atari_partition,
+#endif
+#ifdef CONFIG_MAC_PARTITION
+ mac_partition,
+#endif
+#ifdef CONFIG_ULTRIX_PARTITION
+ ultrix_partition,
+#endif
+#ifdef CONFIG_IBM_PARTITION
+ ibm_partition,
+#endif
+#ifdef CONFIG_KARMA_PARTITION
+ karma_partition,
+#endif
+#ifdef CONFIG_SYSV68_PARTITION
+ sysv68_partition,
+#endif
+ NULL
+};
+
+static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
+{
+ struct parsed_partitions *state;
+ int nr;
+
+ state = kzalloc(sizeof(*state), GFP_KERNEL);
+ if (!state)
+ return NULL;
+
+ nr = disk_max_parts(hd);
+ state->parts = vzalloc(nr * sizeof(state->parts[0]));
+ if (!state->parts) {
+ kfree(state);
+ return NULL;
+ }
+
+ state->limit = nr;
+
+ return state;
+}
+
+void free_partitions(struct parsed_partitions *state)
+{
+ vfree(state->parts);
+ kfree(state);
+}
+
+struct parsed_partitions *
+check_partition(struct gendisk *hd, struct block_device *bdev)
+{
+ struct parsed_partitions *state;
+ int i, res, err;
+
+ state = allocate_partitions(hd);
+ if (!state)
+ return NULL;
+ state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
+ if (!state->pp_buf) {
+ free_partitions(state);
+ return NULL;
+ }
+ state->pp_buf[0] = '\0';
+
+ state->bdev = bdev;
+ disk_name(hd, 0, state->name);
+ snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
+ if (isdigit(state->name[strlen(state->name)-1]))
+ sprintf(state->name, "p");
+
+ i = res = err = 0;
+ while (!res && check_part[i]) {
+ memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
+ res = check_part[i++](state);
+ if (res < 0) {
+ /* We have hit an I/O error which we don't report now.
+ * But record it, and let the others do their job.
+ */
+ err = res;
+ res = 0;
+ }
+
+ }
+ if (res > 0) {
+ printk(KERN_INFO "%s", state->pp_buf);
+
+ free_page((unsigned long)state->pp_buf);
+ return state;
+ }
+ if (state->access_beyond_eod)
+ err = -ENOSPC;
+ if (err)
+ /* The partition is unrecognized. So report I/O errors if there were any */
+ res = err;
+ if (res) {
+ if (warn_no_part)
+ strlcat(state->pp_buf,
+ " unable to read partition table\n", PAGE_SIZE);
+ printk(KERN_INFO "%s", state->pp_buf);
+ }
+
+ free_page((unsigned long)state->pp_buf);
+ free_partitions(state);
+ return ERR_PTR(res);
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/check.h b/src/kernel/linux/v4.14/block/partitions/check.h
new file mode 100644
index 0000000..6042f76
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/check.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/pagemap.h>
+#include <linux/blkdev.h>
+#include <linux/genhd.h>
+
+/*
+ * add_gd_partition adds a partitions details to the devices partition
+ * description.
+ */
+struct parsed_partitions {
+ struct block_device *bdev;
+ char name[BDEVNAME_SIZE];
+ struct {
+ sector_t from;
+ sector_t size;
+ int flags;
+ bool has_info;
+ struct partition_meta_info info;
+ } *parts;
+ int next;
+ int limit;
+ bool access_beyond_eod;
+ char *pp_buf;
+};
+
+void free_partitions(struct parsed_partitions *state);
+
+struct parsed_partitions *
+check_partition(struct gendisk *, struct block_device *);
+
+static inline void *read_part_sector(struct parsed_partitions *state,
+ sector_t n, Sector *p)
+{
+ if (n >= get_capacity(state->bdev->bd_disk)) {
+ state->access_beyond_eod = true;
+ return NULL;
+ }
+ return read_dev_sector(state->bdev, n, p);
+}
+
+static inline void
+put_partition(struct parsed_partitions *p, int n, sector_t from, sector_t size)
+{
+ if (n < p->limit) {
+ char tmp[1 + BDEVNAME_SIZE + 10 + 1];
+
+ p->parts[n].from = from;
+ p->parts[n].size = size;
+ snprintf(tmp, sizeof(tmp), " %s%d", p->name, n);
+ strlcat(p->pp_buf, tmp, PAGE_SIZE);
+ }
+}
+
+extern int warn_no_part;
+
diff --git a/src/kernel/linux/v4.14/block/partitions/cmdline.c b/src/kernel/linux/v4.14/block/partitions/cmdline.c
new file mode 100644
index 0000000..e333583
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/cmdline.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013 HUAWEI
+ * Author: Cai Zhiyong <caizhiyong@huawei.com>
+ *
+ * Read block device partition table from the command line.
+ * Typically used for fixed block (eMMC) embedded devices.
+ * It has no MBR, so saves storage space. Bootloader can be easily accessed
+ * by absolute address of data on the block device.
+ * Users can easily change the partition.
+ *
+ * The format for the command line is just like mtdparts.
+ *
+ * For further information, see "Documentation/block/cmdline-partition.txt"
+ *
+ */
+
+#include <linux/cmdline-parser.h>
+
+#include "check.h"
+#include "cmdline.h"
+
+static char *cmdline;
+static struct cmdline_parts *bdev_parts;
+
+static int add_part(int slot, struct cmdline_subpart *subpart, void *param)
+{
+ int label_min;
+ struct partition_meta_info *info;
+ char tmp[sizeof(info->volname) + 4];
+ struct parsed_partitions *state = (struct parsed_partitions *)param;
+
+ if (slot >= state->limit)
+ return 1;
+
+ put_partition(state, slot, subpart->from >> 9,
+ subpart->size >> 9);
+
+ info = &state->parts[slot].info;
+
+ label_min = min_t(int, sizeof(info->volname) - 1,
+ sizeof(subpart->name));
+ strncpy(info->volname, subpart->name, label_min);
+ info->volname[label_min] = '\0';
+
+ snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+
+ state->parts[slot].has_info = true;
+
+ return 0;
+}
+
+static int __init cmdline_parts_setup(char *s)
+{
+ cmdline = s;
+ return 1;
+}
+__setup("blkdevparts=", cmdline_parts_setup);
+
+/*
+ * Purpose: allocate cmdline partitions.
+ * Returns:
+ * -1 if unable to read the partition table
+ * 0 if this isn't our partition table
+ * 1 if successful
+ */
+int cmdline_partition(struct parsed_partitions *state)
+{
+ sector_t disk_size;
+ char bdev[BDEVNAME_SIZE];
+ struct cmdline_parts *parts;
+
+ if (cmdline) {
+ if (bdev_parts)
+ cmdline_parts_free(&bdev_parts);
+
+ if (cmdline_parts_parse(&bdev_parts, cmdline)) {
+ cmdline = NULL;
+ return -1;
+ }
+ cmdline = NULL;
+ }
+
+ if (!bdev_parts)
+ return 0;
+
+ bdevname(state->bdev, bdev);
+ parts = cmdline_parts_find(bdev_parts, bdev);
+ if (!parts)
+ return 0;
+
+ disk_size = get_capacity(state->bdev->bd_disk) << 9;
+
+ cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state);
+
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+
+ return 1;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/cmdline.h b/src/kernel/linux/v4.14/block/partitions/cmdline.h
new file mode 100644
index 0000000..e64a316
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/cmdline.h
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+int cmdline_partition(struct parsed_partitions *state);
diff --git a/src/kernel/linux/v4.14/block/partitions/efi.c b/src/kernel/linux/v4.14/block/partitions/efi.c
new file mode 100644
index 0000000..39f70d9
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/efi.c
@@ -0,0 +1,744 @@
+/************************************************************
+ * EFI GUID Partition Table handling
+ *
+ * http://www.uefi.org/specs/
+ * http://www.intel.com/technology/efi/
+ *
+ * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com>
+ * Copyright 2000,2001,2002,2004 Dell Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ *
+ * TODO:
+ *
+ * Changelog:
+ * Mon August 5th, 2013 Davidlohr Bueso <davidlohr@hp.com>
+ * - detect hybrid MBRs, tighter pMBR checking & cleanups.
+ *
+ * Mon Nov 09 2004 Matt Domsch <Matt_Domsch@dell.com>
+ * - test for valid PMBR and valid PGPT before ever reading
+ * AGPT, allow override with 'gpt' kernel command line option.
+ * - check for first/last_usable_lba outside of size of disk
+ *
+ * Tue Mar 26 2002 Matt Domsch <Matt_Domsch@dell.com>
+ * - Ported to 2.5.7-pre1 and 2.5.7-dj2
+ * - Applied patch to avoid fault in alternate header handling
+ * - cleaned up find_valid_gpt
+ * - On-disk structure and copy in memory is *always* LE now -
+ * swab fields as needed
+ * - remove print_gpt_header()
+ * - only use first max_p partition entries, to keep the kernel minor number
+ * and partition numbers tied.
+ *
+ * Mon Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com>
+ * - Removed __PRIPTR_PREFIX - not being used
+ *
+ * Mon Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com>
+ * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied
+ *
+ * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com>
+ * - Added compare_gpts().
+ * - moved le_efi_guid_to_cpus() back into this file. GPT is the only
+ * thing that keeps EFI GUIDs on disk.
+ * - Changed gpt structure names and members to be simpler and more Linux-like.
+ *
+ * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com>
+ * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck
+ *
+ * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com>
+ * - Changed function comments to DocBook style per Andreas Dilger suggestion.
+ *
+ * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com>
+ * - Change read_lba() to use the page cache per Al Viro's work.
+ * - print u64s properly on all architectures
+ * - fixed debug_printk(), now Dprintk()
+ *
+ * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com>
+ * - Style cleanups
+ * - made most functions static
+ * - Endianness addition
+ * - remove test for second alternate header, as it's not per spec,
+ * and is unnecessary. There's now a method to read/write the last
+ * sector of an odd-sized disk from user space. No tools have ever
+ * been released which used this code, so it's effectively dead.
+ * - Per Asit Mallick of Intel, added a test for a valid PMBR.
+ * - Added kernel command line option 'gpt' to override valid PMBR test.
+ *
+ * Wed Jun 6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com>
+ * - added devfs volume UUID support (/dev/volumes/uuids) for
+ * mounting file systems by the partition GUID.
+ *
+ * Tue Dec 5 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * - Moved crc32() to linux/lib, added efi_crc32().
+ *
+ * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * - Replaced Intel's CRC32 function with an equivalent
+ * non-license-restricted version.
+ *
+ * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * - Fixed the last_lba() call to return the proper last block
+ *
+ * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * - Thanks to Andries Brouwer for his debugging assistance.
+ * - Code works, detects all the partitions.
+ *
+ ************************************************************/
+#include <linux/kernel.h>
+#include <linux/crc32.h>
+#include <linux/ctype.h>
+#include <linux/math64.h>
+#include <linux/slab.h>
+#include "check.h"
+#include "efi.h"
+
+/* This allows a kernel command line option 'gpt' to override
+ * the test for invalid PMBR. Not __initdata because reloading
+ * the partition tables happens after init too.
+ */
+static int force_gpt;
+static int __init
+force_gpt_fn(char *str)
+{
+ force_gpt = 1;
+ return 1;
+}
+__setup("gpt", force_gpt_fn);
+
+
+/**
+ * efi_crc32() - EFI version of crc32 function
+ * @buf: buffer to calculate crc32 of
+ * @len: length of buf
+ *
+ * Description: Returns EFI-style CRC32 value for @buf
+ *
+ * This function uses the little endian Ethernet polynomial
+ * but seeds the function with ~0, and xor's with ~0 at the end.
+ * Note, the EFI Specification, v1.02, has a reference to
+ * Dr. Dobbs Journal, May 1994 (actually it's in May 1992).
+ */
+static inline u32
+efi_crc32(const void *buf, unsigned long len)
+{
+ return (crc32(~0L, buf, len) ^ ~0L);
+}
+
+/**
+ * last_lba(): return number of last logical block of device
+ * @bdev: block device
+ *
+ * Description: Returns last LBA value on success, 0 on error.
+ * This is stored (by sd and ide-geometry) in
+ * the part[0] entry for this disk, and is the number of
+ * physical sectors available on the disk.
+ */
+static u64 last_lba(struct block_device *bdev)
+{
+ if (!bdev || !bdev->bd_inode)
+ return 0;
+ return div_u64(bdev->bd_inode->i_size,
+ bdev_logical_block_size(bdev)) - 1ULL;
+}
+
+static inline int pmbr_part_valid(gpt_mbr_record *part)
+{
+ if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT)
+ goto invalid;
+
+ /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */
+ if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA)
+ goto invalid;
+
+ return GPT_MBR_PROTECTIVE;
+invalid:
+ return 0;
+}
+
+/**
+ * is_pmbr_valid(): test Protective MBR for validity
+ * @mbr: pointer to a legacy mbr structure
+ * @total_sectors: amount of sectors in the device
+ *
+ * Description: Checks for a valid protective or hybrid
+ * master boot record (MBR). The validity of a pMBR depends
+ * on all of the following properties:
+ * 1) MSDOS signature is in the last two bytes of the MBR
+ * 2) One partition of type 0xEE is found
+ *
+ * In addition, a hybrid MBR will have up to three additional
+ * primary partitions, which point to the same space that's
+ * marked out by up to three GPT partitions.
+ *
+ * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or
+ * GPT_MBR_HYBRID depending on the device layout.
+ */
+static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors)
+{
+ uint32_t sz = 0;
+ int i, part = 0, ret = 0; /* invalid by default */
+
+ if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
+ goto done;
+
+ for (i = 0; i < 4; i++) {
+ ret = pmbr_part_valid(&mbr->partition_record[i]);
+ if (ret == GPT_MBR_PROTECTIVE) {
+ part = i;
+ /*
+ * Ok, we at least know that there's a protective MBR,
+ * now check if there are other partition types for
+ * hybrid MBR.
+ */
+ goto check_hybrid;
+ }
+ }
+
+ if (ret != GPT_MBR_PROTECTIVE)
+ goto done;
+check_hybrid:
+ for (i = 0; i < 4; i++)
+ if ((mbr->partition_record[i].os_type !=
+ EFI_PMBR_OSTYPE_EFI_GPT) &&
+ (mbr->partition_record[i].os_type != 0x00))
+ ret = GPT_MBR_HYBRID;
+
+ /*
+ * Protective MBRs take up the lesser of the whole disk
+ * or 2 TiB (32bit LBA), ignoring the rest of the disk.
+ * Some partitioning programs, nonetheless, choose to set
+ * the size to the maximum 32-bit limitation, disregarding
+ * the disk size.
+ *
+ * Hybrid MBRs do not necessarily comply with this.
+ *
+ * Consider a bad value here to be a warning to support dd'ing
+ * an image from a smaller disk to a larger disk.
+ */
+ if (ret == GPT_MBR_PROTECTIVE) {
+ sz = le32_to_cpu(mbr->partition_record[part].size_in_lba);
+ if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF)
+ pr_debug("GPT: mbr size in lba (%u) different than whole disk (%u).\n",
+ sz, min_t(uint32_t,
+ total_sectors - 1, 0xFFFFFFFF));
+ }
+done:
+ return ret;
+}
+
+/**
+ * read_lba(): Read bytes from disk, starting at given LBA
+ * @state: disk parsed partitions
+ * @lba: the Logical Block Address of the partition table
+ * @buffer: destination buffer
+ * @count: bytes to read
+ *
+ * Description: Reads @count bytes from @state->bdev into @buffer.
+ * Returns number of bytes read on success, 0 on error.
+ */
+static size_t read_lba(struct parsed_partitions *state,
+ u64 lba, u8 *buffer, size_t count)
+{
+ size_t totalreadcount = 0;
+ struct block_device *bdev = state->bdev;
+ sector_t n = lba * (bdev_logical_block_size(bdev) / 512);
+
+ if (!buffer || lba > last_lba(bdev))
+ return 0;
+
+ while (count) {
+ int copied = 512;
+ Sector sect;
+ unsigned char *data = read_part_sector(state, n++, §);
+ if (!data)
+ break;
+ if (copied > count)
+ copied = count;
+ memcpy(buffer, data, copied);
+ put_dev_sector(sect);
+ buffer += copied;
+ totalreadcount +=copied;
+ count -= copied;
+ }
+ return totalreadcount;
+}
+
+/**
+ * alloc_read_gpt_entries(): reads partition entries from disk
+ * @state: disk parsed partitions
+ * @gpt: GPT header
+ *
+ * Description: Returns ptes on success, NULL on error.
+ * Allocates space for PTEs based on information found in @gpt.
+ * Notes: remember to free pte when you're done!
+ */
+static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state,
+ gpt_header *gpt)
+{
+ size_t count;
+ gpt_entry *pte;
+
+ if (!gpt)
+ return NULL;
+
+ count = (size_t)le32_to_cpu(gpt->num_partition_entries) *
+ le32_to_cpu(gpt->sizeof_partition_entry);
+ if (!count)
+ return NULL;
+ pte = kmalloc(count, GFP_KERNEL);
+ if (!pte)
+ return NULL;
+
+ if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
+ (u8 *) pte, count) < count) {
+ kfree(pte);
+ pte=NULL;
+ return NULL;
+ }
+ return pte;
+}
+
+/**
+ * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
+ * @state: disk parsed partitions
+ * @lba: the Logical Block Address of the partition table
+ *
+ * Description: returns GPT header on success, NULL on error. Allocates
+ * and fills a GPT header starting at @ from @state->bdev.
+ * Note: remember to free gpt when finished with it.
+ */
+static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
+ u64 lba)
+{
+ gpt_header *gpt;
+ unsigned ssz = bdev_logical_block_size(state->bdev);
+
+ gpt = kmalloc(ssz, GFP_KERNEL);
+ if (!gpt)
+ return NULL;
+
+ if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
+ kfree(gpt);
+ gpt=NULL;
+ return NULL;
+ }
+
+ return gpt;
+}
+
+/**
+ * is_gpt_valid() - tests one GPT header and PTEs for validity
+ * @state: disk parsed partitions
+ * @lba: logical block address of the GPT header to test
+ * @gpt: GPT header ptr, filled on return.
+ * @ptes: PTEs ptr, filled on return.
+ *
+ * Description: returns 1 if valid, 0 on error.
+ * If valid, returns pointers to newly allocated GPT header and PTEs.
+ */
+static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
+ gpt_header **gpt, gpt_entry **ptes)
+{
+ u32 crc, origcrc;
+ u64 lastlba, pt_size;
+
+ if (!ptes)
+ return 0;
+ if (!(*gpt = alloc_read_gpt_header(state, lba)))
+ return 0;
+
+ /* Check the GUID Partition Table signature */
+ if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
+ pr_debug("GUID Partition Table Header signature is wrong:"
+ "%lld != %lld\n",
+ (unsigned long long)le64_to_cpu((*gpt)->signature),
+ (unsigned long long)GPT_HEADER_SIGNATURE);
+ goto fail;
+ }
+
+ /* Check the GUID Partition Table header size is too big */
+ if (le32_to_cpu((*gpt)->header_size) >
+ bdev_logical_block_size(state->bdev)) {
+ pr_debug("GUID Partition Table Header size is too large: %u > %u\n",
+ le32_to_cpu((*gpt)->header_size),
+ bdev_logical_block_size(state->bdev));
+ goto fail;
+ }
+
+ /* Check the GUID Partition Table header size is too small */
+ if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) {
+ pr_debug("GUID Partition Table Header size is too small: %u < %zu\n",
+ le32_to_cpu((*gpt)->header_size),
+ sizeof(gpt_header));
+ goto fail;
+ }
+
+ /* Check the GUID Partition Table CRC */
+ origcrc = le32_to_cpu((*gpt)->header_crc32);
+ (*gpt)->header_crc32 = 0;
+ crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
+
+ if (crc != origcrc) {
+ pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
+ crc, origcrc);
+ goto fail;
+ }
+ (*gpt)->header_crc32 = cpu_to_le32(origcrc);
+
+ /* Check that the my_lba entry points to the LBA that contains
+ * the GUID Partition Table */
+ if (le64_to_cpu((*gpt)->my_lba) != lba) {
+ pr_debug("GPT my_lba incorrect: %lld != %lld\n",
+ (unsigned long long)le64_to_cpu((*gpt)->my_lba),
+ (unsigned long long)lba);
+ goto fail;
+ }
+
+ /* Check the first_usable_lba and last_usable_lba are
+ * within the disk.
+ */
+ lastlba = last_lba(state->bdev);
+ if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
+ pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
+ (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
+ (unsigned long long)lastlba);
+ goto fail;
+ }
+ if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
+ pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
+ (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
+ (unsigned long long)lastlba);
+ goto fail;
+ }
+ if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) {
+ pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
+ (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
+ (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba));
+ goto fail;
+ }
+ /* Check that sizeof_partition_entry has the correct value */
+ if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
+ pr_debug("GUID Partition Entry Size check failed.\n");
+ goto fail;
+ }
+
+ /* Sanity check partition table size */
+ pt_size = (u64)le32_to_cpu((*gpt)->num_partition_entries) *
+ le32_to_cpu((*gpt)->sizeof_partition_entry);
+ if (pt_size > KMALLOC_MAX_SIZE) {
+ pr_debug("GUID Partition Table is too large: %llu > %lu bytes\n",
+ (unsigned long long)pt_size, KMALLOC_MAX_SIZE);
+ goto fail;
+ }
+
+ if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
+ goto fail;
+
+ /* Check the GUID Partition Entry Array CRC */
+ crc = efi_crc32((const unsigned char *) (*ptes), pt_size);
+
+ if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
+ pr_debug("GUID Partition Entry Array CRC check failed.\n");
+ goto fail_ptes;
+ }
+
+ /* We're done, all's well */
+ return 1;
+
+ fail_ptes:
+ kfree(*ptes);
+ *ptes = NULL;
+ fail:
+ kfree(*gpt);
+ *gpt = NULL;
+ return 0;
+}
+
+/**
+ * is_pte_valid() - tests one PTE for validity
+ * @pte:pte to check
+ * @lastlba: last lba of the disk
+ *
+ * Description: returns 1 if valid, 0 on error.
+ */
+static inline int
+is_pte_valid(const gpt_entry *pte, const u64 lastlba)
+{
+ if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
+ le64_to_cpu(pte->starting_lba) > lastlba ||
+ le64_to_cpu(pte->ending_lba) > lastlba)
+ return 0;
+ return 1;
+}
+
+/**
+ * compare_gpts() - Search disk for valid GPT headers and PTEs
+ * @pgpt: primary GPT header
+ * @agpt: alternate GPT header
+ * @lastlba: last LBA number
+ *
+ * Description: Returns nothing. Sanity checks pgpt and agpt fields
+ * and prints warnings on discrepancies.
+ *
+ */
+static void
+compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
+{
+ int error_found = 0;
+ if (!pgpt || !agpt)
+ return;
+ if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
+ pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n");
+ pr_warn("GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->my_lba),
+ (unsigned long long)le64_to_cpu(agpt->alternate_lba));
+ error_found++;
+ }
+ if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
+ pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n");
+ pr_warn("GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
+ (unsigned long long)le64_to_cpu(agpt->my_lba));
+ error_found++;
+ }
+ if (le64_to_cpu(pgpt->first_usable_lba) !=
+ le64_to_cpu(agpt->first_usable_lba)) {
+ pr_warn("GPT:first_usable_lbas don't match.\n");
+ pr_warn("GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
+ (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
+ error_found++;
+ }
+ if (le64_to_cpu(pgpt->last_usable_lba) !=
+ le64_to_cpu(agpt->last_usable_lba)) {
+ pr_warn("GPT:last_usable_lbas don't match.\n");
+ pr_warn("GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
+ (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
+ error_found++;
+ }
+ if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
+ pr_warn("GPT:disk_guids don't match.\n");
+ error_found++;
+ }
+ if (le32_to_cpu(pgpt->num_partition_entries) !=
+ le32_to_cpu(agpt->num_partition_entries)) {
+ pr_warn("GPT:num_partition_entries don't match: "
+ "0x%x != 0x%x\n",
+ le32_to_cpu(pgpt->num_partition_entries),
+ le32_to_cpu(agpt->num_partition_entries));
+ error_found++;
+ }
+ if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
+ le32_to_cpu(agpt->sizeof_partition_entry)) {
+ pr_warn("GPT:sizeof_partition_entry values don't match: "
+ "0x%x != 0x%x\n",
+ le32_to_cpu(pgpt->sizeof_partition_entry),
+ le32_to_cpu(agpt->sizeof_partition_entry));
+ error_found++;
+ }
+ if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
+ le32_to_cpu(agpt->partition_entry_array_crc32)) {
+ pr_warn("GPT:partition_entry_array_crc32 values don't match: "
+ "0x%x != 0x%x\n",
+ le32_to_cpu(pgpt->partition_entry_array_crc32),
+ le32_to_cpu(agpt->partition_entry_array_crc32));
+ error_found++;
+ }
+ if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
+ pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
+ pr_warn("GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
+ (unsigned long long)lastlba);
+ error_found++;
+ }
+
+ if (le64_to_cpu(agpt->my_lba) != lastlba) {
+ pr_warn("GPT:Alternate GPT header not at the end of the disk.\n");
+ pr_warn("GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(agpt->my_lba),
+ (unsigned long long)lastlba);
+ error_found++;
+ }
+
+ if (error_found)
+ pr_warn("GPT: Use GNU Parted to correct GPT errors.\n");
+ return;
+}
+
+/**
+ * find_valid_gpt() - Search disk for valid GPT headers and PTEs
+ * @state: disk parsed partitions
+ * @gpt: GPT header ptr, filled on return.
+ * @ptes: PTEs ptr, filled on return.
+ *
+ * Description: Returns 1 if valid, 0 on error.
+ * If valid, returns pointers to newly allocated GPT header and PTEs.
+ * Validity depends on PMBR being valid (or being overridden by the
+ * 'gpt' kernel command line option) and finding either the Primary
+ * GPT header and PTEs valid, or the Alternate GPT header and PTEs
+ * valid. If the Primary GPT header is not valid, the Alternate GPT header
+ * is not checked unless the 'gpt' kernel command line option is passed.
+ * This protects against devices which misreport their size, and forces
+ * the user to decide to use the Alternate GPT.
+ */
+static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
+ gpt_entry **ptes)
+{
+ int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
+ gpt_header *pgpt = NULL, *agpt = NULL;
+ gpt_entry *pptes = NULL, *aptes = NULL;
+ legacy_mbr *legacymbr;
+ sector_t total_sectors = i_size_read(state->bdev->bd_inode) >> 9;
+ u64 lastlba;
+
+ if (!ptes)
+ return 0;
+
+ lastlba = last_lba(state->bdev);
+ if (!force_gpt) {
+ /* This will be added to the EFI Spec. per Intel after v1.02. */
+ legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL);
+ if (!legacymbr)
+ goto fail;
+
+ read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr));
+ good_pmbr = is_pmbr_valid(legacymbr, total_sectors);
+ kfree(legacymbr);
+
+ if (!good_pmbr)
+ goto fail;
+
+ pr_debug("Device has a %s MBR\n",
+ good_pmbr == GPT_MBR_PROTECTIVE ?
+ "protective" : "hybrid");
+ }
+
+ good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA,
+ &pgpt, &pptes);
+ if (good_pgpt)
+ good_agpt = is_gpt_valid(state,
+ le64_to_cpu(pgpt->alternate_lba),
+ &agpt, &aptes);
+ if (!good_agpt && force_gpt)
+ good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
+
+ /* The obviously unsuccessful case */
+ if (!good_pgpt && !good_agpt)
+ goto fail;
+
+ compare_gpts(pgpt, agpt, lastlba);
+
+ /* The good cases */
+ if (good_pgpt) {
+ *gpt = pgpt;
+ *ptes = pptes;
+ kfree(agpt);
+ kfree(aptes);
+ if (!good_agpt)
+ pr_warn("Alternate GPT is invalid, using primary GPT.\n");
+ return 1;
+ }
+ else if (good_agpt) {
+ *gpt = agpt;
+ *ptes = aptes;
+ kfree(pgpt);
+ kfree(pptes);
+ pr_warn("Primary GPT is invalid, using alternate GPT.\n");
+ return 1;
+ }
+
+ fail:
+ kfree(pgpt);
+ kfree(agpt);
+ kfree(pptes);
+ kfree(aptes);
+ *gpt = NULL;
+ *ptes = NULL;
+ return 0;
+}
+
+/**
+ * efi_partition(struct parsed_partitions *state)
+ * @state: disk parsed partitions
+ *
+ * Description: called from check.c, if the disk contains GPT
+ * partitions, sets up partition entries in the kernel.
+ *
+ * If the first block on the disk is a legacy MBR,
+ * it will get handled by msdos_partition().
+ * If it's a Protective MBR, we'll handle it here.
+ *
+ * We do not create a Linux partition for GPT, but
+ * only for the actual data partitions.
+ * Returns:
+ * -1 if unable to read the partition table
+ * 0 if this isn't our partition table
+ * 1 if successful
+ *
+ */
+int efi_partition(struct parsed_partitions *state)
+{
+ gpt_header *gpt = NULL;
+ gpt_entry *ptes = NULL;
+ u32 i;
+ unsigned ssz = bdev_logical_block_size(state->bdev) / 512;
+
+ if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
+ kfree(gpt);
+ kfree(ptes);
+ return 0;
+ }
+
+ pr_debug("GUID Partition Table is valid! Yea!\n");
+
+ for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
+ struct partition_meta_info *info;
+ unsigned label_count = 0;
+ unsigned label_max;
+ u64 start = le64_to_cpu(ptes[i].starting_lba);
+ u64 size = le64_to_cpu(ptes[i].ending_lba) -
+ le64_to_cpu(ptes[i].starting_lba) + 1ULL;
+
+ if (!is_pte_valid(&ptes[i], last_lba(state->bdev)))
+ continue;
+
+ put_partition(state, i+1, start * ssz, size * ssz);
+
+ /* If this is a RAID volume, tell md */
+ if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID))
+ state->parts[i + 1].flags = ADDPART_FLAG_RAID;
+
+ info = &state->parts[i + 1].info;
+ efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid);
+
+ /* Naively convert UTF16-LE to 7 bits. */
+ label_max = min(ARRAY_SIZE(info->volname) - 1,
+ ARRAY_SIZE(ptes[i].partition_name));
+ info->volname[label_max] = 0;
+ while (label_count < label_max) {
+ u8 c = ptes[i].partition_name[label_count] & 0xff;
+ if (c && !isprint(c))
+ c = '!';
+ info->volname[label_count] = c;
+ label_count++;
+ }
+ state->parts[i + 1].has_info = true;
+ }
+ kfree(ptes);
+ kfree(gpt);
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ return 1;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/efi.h b/src/kernel/linux/v4.14/block/partitions/efi.h
new file mode 100644
index 0000000..abd0b19
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/efi.h
@@ -0,0 +1,133 @@
+/************************************************************
+ * EFI GUID Partition Table
+ * Per Intel EFI Specification v1.02
+ * http://developer.intel.com/technology/efi/efi.htm
+ *
+ * By Matt Domsch <Matt_Domsch@dell.com> Fri Sep 22 22:15:56 CDT 2000
+ * Copyright 2000,2001 Dell Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ ************************************************************/
+
+#ifndef FS_PART_EFI_H_INCLUDED
+#define FS_PART_EFI_H_INCLUDED
+
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/genhd.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/efi.h>
+#include <linux/compiler.h>
+
+#define MSDOS_MBR_SIGNATURE 0xaa55
+#define EFI_PMBR_OSTYPE_EFI 0xEF
+#define EFI_PMBR_OSTYPE_EFI_GPT 0xEE
+
+#define GPT_MBR_PROTECTIVE 1
+#define GPT_MBR_HYBRID 2
+
+#define GPT_HEADER_SIGNATURE 0x5452415020494645ULL
+#define GPT_HEADER_REVISION_V1 0x00010000
+#define GPT_PRIMARY_PARTITION_TABLE_LBA 1
+
+#define PARTITION_SYSTEM_GUID \
+ EFI_GUID( 0xC12A7328, 0xF81F, 0x11d2, \
+ 0xBA, 0x4B, 0x00, 0xA0, 0xC9, 0x3E, 0xC9, 0x3B)
+#define LEGACY_MBR_PARTITION_GUID \
+ EFI_GUID( 0x024DEE41, 0x33E7, 0x11d3, \
+ 0x9D, 0x69, 0x00, 0x08, 0xC7, 0x81, 0xF3, 0x9F)
+#define PARTITION_MSFT_RESERVED_GUID \
+ EFI_GUID( 0xE3C9E316, 0x0B5C, 0x4DB8, \
+ 0x81, 0x7D, 0xF9, 0x2D, 0xF0, 0x02, 0x15, 0xAE)
+#define PARTITION_BASIC_DATA_GUID \
+ EFI_GUID( 0xEBD0A0A2, 0xB9E5, 0x4433, \
+ 0x87, 0xC0, 0x68, 0xB6, 0xB7, 0x26, 0x99, 0xC7)
+#define PARTITION_LINUX_RAID_GUID \
+ EFI_GUID( 0xa19d880f, 0x05fc, 0x4d3b, \
+ 0xa0, 0x06, 0x74, 0x3f, 0x0f, 0x84, 0x91, 0x1e)
+#define PARTITION_LINUX_SWAP_GUID \
+ EFI_GUID( 0x0657fd6d, 0xa4ab, 0x43c4, \
+ 0x84, 0xe5, 0x09, 0x33, 0xc8, 0x4b, 0x4f, 0x4f)
+#define PARTITION_LINUX_LVM_GUID \
+ EFI_GUID( 0xe6d6d379, 0xf507, 0x44c2, \
+ 0xa2, 0x3c, 0x23, 0x8f, 0x2a, 0x3d, 0xf9, 0x28)
+
+typedef struct _gpt_header {
+ __le64 signature;
+ __le32 revision;
+ __le32 header_size;
+ __le32 header_crc32;
+ __le32 reserved1;
+ __le64 my_lba;
+ __le64 alternate_lba;
+ __le64 first_usable_lba;
+ __le64 last_usable_lba;
+ efi_guid_t disk_guid;
+ __le64 partition_entry_lba;
+ __le32 num_partition_entries;
+ __le32 sizeof_partition_entry;
+ __le32 partition_entry_array_crc32;
+
+ /* The rest of the logical block is reserved by UEFI and must be zero.
+ * EFI standard handles this by:
+ *
+ * uint8_t reserved2[ BlockSize - 92 ];
+ */
+} __packed gpt_header;
+
+typedef struct _gpt_entry_attributes {
+ u64 required_to_function:1;
+ u64 reserved:47;
+ u64 type_guid_specific:16;
+} __packed gpt_entry_attributes;
+
+typedef struct _gpt_entry {
+ efi_guid_t partition_type_guid;
+ efi_guid_t unique_partition_guid;
+ __le64 starting_lba;
+ __le64 ending_lba;
+ gpt_entry_attributes attributes;
+ efi_char16_t partition_name[72 / sizeof (efi_char16_t)];
+} __packed gpt_entry;
+
+typedef struct _gpt_mbr_record {
+ u8 boot_indicator; /* unused by EFI, set to 0x80 for bootable */
+ u8 start_head; /* unused by EFI, pt start in CHS */
+ u8 start_sector; /* unused by EFI, pt start in CHS */
+ u8 start_track;
+ u8 os_type; /* EFI and legacy non-EFI OS types */
+ u8 end_head; /* unused by EFI, pt end in CHS */
+ u8 end_sector; /* unused by EFI, pt end in CHS */
+ u8 end_track; /* unused by EFI, pt end in CHS */
+ __le32 starting_lba; /* used by EFI - start addr of the on disk pt */
+ __le32 size_in_lba; /* used by EFI - size of pt in LBA */
+} __packed gpt_mbr_record;
+
+
+typedef struct _legacy_mbr {
+ u8 boot_code[440];
+ __le32 unique_mbr_signature;
+ __le16 unknown;
+ gpt_mbr_record partition_record[4];
+ __le16 signature;
+} __packed legacy_mbr;
+
+/* Functions */
+extern int efi_partition(struct parsed_partitions *state);
+
+#endif
diff --git a/src/kernel/linux/v4.14/block/partitions/ibm.c b/src/kernel/linux/v4.14/block/partitions/ibm.c
new file mode 100644
index 0000000..a5d480f
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/ibm.c
@@ -0,0 +1,365 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ * Volker Sameske <sameske@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2012
+ */
+
+#include <linux/buffer_head.h>
+#include <linux/hdreg.h>
+#include <linux/slab.h>
+#include <asm/dasd.h>
+#include <asm/ebcdic.h>
+#include <linux/uaccess.h>
+#include <asm/vtoc.h>
+
+#include "check.h"
+#include "ibm.h"
+
+
+union label_t {
+ struct vtoc_volume_label_cdl vol;
+ struct vtoc_volume_label_ldl lnx;
+ struct vtoc_cms_label cms;
+};
+
+/*
+ * compute the block number from a
+ * cyl-cyl-head-head structure
+ */
+static sector_t cchh2blk(struct vtoc_cchh *ptr, struct hd_geometry *geo)
+{
+ sector_t cyl;
+ __u16 head;
+
+ /* decode cylinder and heads for large volumes */
+ cyl = ptr->hh & 0xFFF0;
+ cyl <<= 12;
+ cyl |= ptr->cc;
+ head = ptr->hh & 0x000F;
+ return cyl * geo->heads * geo->sectors +
+ head * geo->sectors;
+}
+
+/*
+ * compute the block number from a
+ * cyl-cyl-head-head-block structure
+ */
+static sector_t cchhb2blk(struct vtoc_cchhb *ptr, struct hd_geometry *geo)
+{
+ sector_t cyl;
+ __u16 head;
+
+ /* decode cylinder and heads for large volumes */
+ cyl = ptr->hh & 0xFFF0;
+ cyl <<= 12;
+ cyl |= ptr->cc;
+ head = ptr->hh & 0x000F;
+ return cyl * geo->heads * geo->sectors +
+ head * geo->sectors +
+ ptr->b;
+}
+
+static int find_label(struct parsed_partitions *state,
+ dasd_information2_t *info,
+ struct hd_geometry *geo,
+ int blocksize,
+ sector_t *labelsect,
+ char name[],
+ char type[],
+ union label_t *label)
+{
+ Sector sect;
+ unsigned char *data;
+ sector_t testsect[3];
+ unsigned char temp[5];
+ int found = 0;
+ int i, testcount;
+
+ /* There a three places where we may find a valid label:
+ * - on an ECKD disk it's block 2
+ * - on an FBA disk it's block 1
+ * - on an CMS formatted FBA disk it is sector 1, even if the block size
+ * is larger than 512 bytes (possible if the DIAG discipline is used)
+ * If we have a valid info structure, then we know exactly which case we
+ * have, otherwise we just search through all possebilities.
+ */
+ if (info) {
+ if ((info->cu_type == 0x6310 && info->dev_type == 0x9336) ||
+ (info->cu_type == 0x3880 && info->dev_type == 0x3370))
+ testsect[0] = info->label_block;
+ else
+ testsect[0] = info->label_block * (blocksize >> 9);
+ testcount = 1;
+ } else {
+ testsect[0] = 1;
+ testsect[1] = (blocksize >> 9);
+ testsect[2] = 2 * (blocksize >> 9);
+ testcount = 3;
+ }
+ for (i = 0; i < testcount; ++i) {
+ data = read_part_sector(state, testsect[i], §);
+ if (data == NULL)
+ continue;
+ memcpy(label, data, sizeof(*label));
+ memcpy(temp, data, 4);
+ temp[4] = 0;
+ EBCASC(temp, 4);
+ put_dev_sector(sect);
+ if (!strcmp(temp, "VOL1") ||
+ !strcmp(temp, "LNX1") ||
+ !strcmp(temp, "CMS1")) {
+ if (!strcmp(temp, "VOL1")) {
+ strncpy(type, label->vol.vollbl, 4);
+ strncpy(name, label->vol.volid, 6);
+ } else {
+ strncpy(type, label->lnx.vollbl, 4);
+ strncpy(name, label->lnx.volid, 6);
+ }
+ EBCASC(type, 4);
+ EBCASC(name, 6);
+ *labelsect = testsect[i];
+ found = 1;
+ break;
+ }
+ }
+ if (!found)
+ memset(label, 0, sizeof(*label));
+
+ return found;
+}
+
+static int find_vol1_partitions(struct parsed_partitions *state,
+ struct hd_geometry *geo,
+ int blocksize,
+ char name[],
+ union label_t *label)
+{
+ sector_t blk;
+ int counter;
+ char tmp[64];
+ Sector sect;
+ unsigned char *data;
+ loff_t offset, size;
+ struct vtoc_format1_label f1;
+ int secperblk;
+
+ snprintf(tmp, sizeof(tmp), "VOL1/%8s:", name);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ /*
+ * get start of VTOC from the disk label and then search for format1
+ * and format8 labels
+ */
+ secperblk = blocksize >> 9;
+ blk = cchhb2blk(&label->vol.vtoc, geo) + 1;
+ counter = 0;
+ data = read_part_sector(state, blk * secperblk, §);
+ while (data != NULL) {
+ memcpy(&f1, data, sizeof(struct vtoc_format1_label));
+ put_dev_sector(sect);
+ /* skip FMT4 / FMT5 / FMT7 labels */
+ if (f1.DS1FMTID == _ascebc['4']
+ || f1.DS1FMTID == _ascebc['5']
+ || f1.DS1FMTID == _ascebc['7']
+ || f1.DS1FMTID == _ascebc['9']) {
+ blk++;
+ data = read_part_sector(state, blk * secperblk, §);
+ continue;
+ }
+ /* only FMT1 and 8 labels valid at this point */
+ if (f1.DS1FMTID != _ascebc['1'] &&
+ f1.DS1FMTID != _ascebc['8'])
+ break;
+ /* OK, we got valid partition data */
+ offset = cchh2blk(&f1.DS1EXT1.llimit, geo);
+ size = cchh2blk(&f1.DS1EXT1.ulimit, geo) -
+ offset + geo->sectors;
+ offset *= secperblk;
+ size *= secperblk;
+ if (counter >= state->limit)
+ break;
+ put_partition(state, counter + 1, offset, size);
+ counter++;
+ blk++;
+ data = read_part_sector(state, blk * secperblk, §);
+ }
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+
+ if (!data)
+ return -1;
+
+ return 1;
+}
+
+static int find_lnx1_partitions(struct parsed_partitions *state,
+ struct hd_geometry *geo,
+ int blocksize,
+ char name[],
+ union label_t *label,
+ sector_t labelsect,
+ loff_t i_size,
+ dasd_information2_t *info)
+{
+ loff_t offset, geo_size, size;
+ char tmp[64];
+ int secperblk;
+
+ snprintf(tmp, sizeof(tmp), "LNX1/%8s:", name);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ secperblk = blocksize >> 9;
+ if (label->lnx.ldl_version == 0xf2) {
+ size = label->lnx.formatted_blocks * secperblk;
+ } else {
+ /*
+ * Formated w/o large volume support. If the sanity check
+ * 'size based on geo == size based on i_size' is true, then
+ * we can safely assume that we know the formatted size of
+ * the disk, otherwise we need additional information
+ * that we can only get from a real DASD device.
+ */
+ geo_size = geo->cylinders * geo->heads
+ * geo->sectors * secperblk;
+ size = i_size >> 9;
+ if (size != geo_size) {
+ if (!info) {
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ return 1;
+ }
+ if (!strcmp(info->type, "ECKD"))
+ if (geo_size < size)
+ size = geo_size;
+ /* else keep size based on i_size */
+ }
+ }
+ /* first and only partition starts in the first block after the label */
+ offset = labelsect + secperblk;
+ put_partition(state, 1, offset, size - offset);
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ return 1;
+}
+
+static int find_cms1_partitions(struct parsed_partitions *state,
+ struct hd_geometry *geo,
+ int blocksize,
+ char name[],
+ union label_t *label,
+ sector_t labelsect)
+{
+ loff_t offset, size;
+ char tmp[64];
+ int secperblk;
+
+ /*
+ * VM style CMS1 labeled disk
+ */
+ blocksize = label->cms.block_size;
+ secperblk = blocksize >> 9;
+ if (label->cms.disk_offset != 0) {
+ snprintf(tmp, sizeof(tmp), "CMS1/%8s(MDSK):", name);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ /* disk is reserved minidisk */
+ offset = label->cms.disk_offset * secperblk;
+ size = (label->cms.block_count - 1) * secperblk;
+ } else {
+ snprintf(tmp, sizeof(tmp), "CMS1/%8s:", name);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ /*
+ * Special case for FBA devices:
+ * If an FBA device is CMS formatted with blocksize > 512 byte
+ * and the DIAG discipline is used, then the CMS label is found
+ * in sector 1 instead of block 1. However, the partition is
+ * still supposed to start in block 2.
+ */
+ if (labelsect == 1)
+ offset = 2 * secperblk;
+ else
+ offset = labelsect + secperblk;
+ size = label->cms.block_count * secperblk;
+ }
+
+ put_partition(state, 1, offset, size-offset);
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ return 1;
+}
+
+
+/*
+ * This is the main function, called by check.c
+ */
+int ibm_partition(struct parsed_partitions *state)
+{
+ struct block_device *bdev = state->bdev;
+ int blocksize, res;
+ loff_t i_size, offset, size;
+ dasd_information2_t *info;
+ struct hd_geometry *geo;
+ char type[5] = {0,};
+ char name[7] = {0,};
+ sector_t labelsect;
+ union label_t *label;
+
+ res = 0;
+ blocksize = bdev_logical_block_size(bdev);
+ if (blocksize <= 0)
+ goto out_exit;
+ i_size = i_size_read(bdev->bd_inode);
+ if (i_size == 0)
+ goto out_exit;
+ info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
+ if (info == NULL)
+ goto out_exit;
+ geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL);
+ if (geo == NULL)
+ goto out_nogeo;
+ label = kmalloc(sizeof(union label_t), GFP_KERNEL);
+ if (label == NULL)
+ goto out_nolab;
+ if (ioctl_by_bdev(bdev, HDIO_GETGEO, (unsigned long)geo) != 0)
+ goto out_freeall;
+ if (ioctl_by_bdev(bdev, BIODASDINFO2, (unsigned long)info) != 0) {
+ kfree(info);
+ info = NULL;
+ }
+
+ if (find_label(state, info, geo, blocksize, &labelsect, name, type,
+ label)) {
+ if (!strncmp(type, "VOL1", 4)) {
+ res = find_vol1_partitions(state, geo, blocksize, name,
+ label);
+ } else if (!strncmp(type, "LNX1", 4)) {
+ res = find_lnx1_partitions(state, geo, blocksize, name,
+ label, labelsect, i_size,
+ info);
+ } else if (!strncmp(type, "CMS1", 4)) {
+ res = find_cms1_partitions(state, geo, blocksize, name,
+ label, labelsect);
+ }
+ } else if (info) {
+ /*
+ * ugly but needed for backward compatibility:
+ * If the block device is a DASD (i.e. BIODASDINFO2 works),
+ * then we claim it in any case, even though it has no valid
+ * label. If it has the LDL format, then we simply define a
+ * partition as if it had an LNX1 label.
+ */
+ res = 1;
+ if (info->format == DASD_FORMAT_LDL) {
+ strlcat(state->pp_buf, "(nonl)", PAGE_SIZE);
+ size = i_size >> 9;
+ offset = (info->label_block + 1) * (blocksize >> 9);
+ put_partition(state, 1, offset, size-offset);
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ }
+ } else
+ res = 0;
+
+out_freeall:
+ kfree(label);
+out_nolab:
+ kfree(geo);
+out_nogeo:
+ kfree(info);
+out_exit:
+ return res;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/ibm.h b/src/kernel/linux/v4.14/block/partitions/ibm.h
new file mode 100644
index 0000000..08fb080
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/ibm.h
@@ -0,0 +1 @@
+int ibm_partition(struct parsed_partitions *);
diff --git a/src/kernel/linux/v4.14/block/partitions/karma.c b/src/kernel/linux/v4.14/block/partitions/karma.c
new file mode 100644
index 0000000..59812d7
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/karma.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/karma.c
+ * Rio Karma partition info.
+ *
+ * Copyright (C) 2006 Bob Copeland (me@bobcopeland.com)
+ * based on osf.c
+ */
+
+#include "check.h"
+#include "karma.h"
+#include <linux/compiler.h>
+
+int karma_partition(struct parsed_partitions *state)
+{
+ int i;
+ int slot = 1;
+ Sector sect;
+ unsigned char *data;
+ struct disklabel {
+ u8 d_reserved[270];
+ struct d_partition {
+ __le32 p_res;
+ u8 p_fstype;
+ u8 p_res2[3];
+ __le32 p_offset;
+ __le32 p_size;
+ } d_partitions[2];
+ u8 d_blank[208];
+ __le16 d_magic;
+ } __packed *label;
+ struct d_partition *p;
+
+ data = read_part_sector(state, 0, §);
+ if (!data)
+ return -1;
+
+ label = (struct disklabel *)data;
+ if (le16_to_cpu(label->d_magic) != KARMA_LABEL_MAGIC) {
+ put_dev_sector(sect);
+ return 0;
+ }
+
+ p = label->d_partitions;
+ for (i = 0 ; i < 2; i++, p++) {
+ if (slot == state->limit)
+ break;
+
+ if (p->p_fstype == 0x4d && le32_to_cpu(p->p_size)) {
+ put_partition(state, slot, le32_to_cpu(p->p_offset),
+ le32_to_cpu(p->p_size));
+ }
+ slot++;
+ }
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ put_dev_sector(sect);
+ return 1;
+}
+
diff --git a/src/kernel/linux/v4.14/block/partitions/karma.h b/src/kernel/linux/v4.14/block/partitions/karma.h
new file mode 100644
index 0000000..c764b2e
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/karma.h
@@ -0,0 +1,8 @@
+/*
+ * fs/partitions/karma.h
+ */
+
+#define KARMA_LABEL_MAGIC 0xAB56
+
+int karma_partition(struct parsed_partitions *state);
+
diff --git a/src/kernel/linux/v4.14/block/partitions/ldm.c b/src/kernel/linux/v4.14/block/partitions/ldm.c
new file mode 100644
index 0000000..2a365c7
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/ldm.c
@@ -0,0 +1,1515 @@
+/**
+ * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
+ *
+ * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
+ * Copyright (c) 2001-2012 Anton Altaparmakov
+ * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
+ *
+ * Documentation is available at http://www.linux-ntfs.org/doku.php?id=downloads
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program (in the main directory of the source in the file COPYING); if
+ * not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307 USA
+ */
+
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/stringify.h>
+#include <linux/kernel.h>
+#include <linux/uuid.h>
+
+#include "ldm.h"
+#include "check.h"
+#include "msdos.h"
+
+/**
+ * ldm_debug/info/error/crit - Output an error message
+ * @f: A printf format string containing the message
+ * @...: Variables to substitute into @f
+ *
+ * ldm_debug() writes a DEBUG level message to the syslog but only if the
+ * driver was compiled with debug enabled. Otherwise, the call turns into a NOP.
+ */
+#ifndef CONFIG_LDM_DEBUG
+#define ldm_debug(...) do {} while (0)
+#else
+#define ldm_debug(f, a...) _ldm_printk (KERN_DEBUG, __func__, f, ##a)
+#endif
+
+#define ldm_crit(f, a...) _ldm_printk (KERN_CRIT, __func__, f, ##a)
+#define ldm_error(f, a...) _ldm_printk (KERN_ERR, __func__, f, ##a)
+#define ldm_info(f, a...) _ldm_printk (KERN_INFO, __func__, f, ##a)
+
+static __printf(3, 4)
+void _ldm_printk(const char *level, const char *function, const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+
+ va_start (args, fmt);
+
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ printk("%s%s(): %pV\n", level, function, &vaf);
+
+ va_end(args);
+}
+
+/**
+ * ldm_parse_privhead - Read the LDM Database PRIVHEAD structure
+ * @data: Raw database PRIVHEAD structure loaded from the device
+ * @ph: In-memory privhead structure in which to return parsed information
+ *
+ * This parses the LDM database PRIVHEAD structure supplied in @data and
+ * sets up the in-memory privhead structure @ph with the obtained information.
+ *
+ * Return: 'true' @ph contains the PRIVHEAD data
+ * 'false' @ph contents are undefined
+ */
+static bool ldm_parse_privhead(const u8 *data, struct privhead *ph)
+{
+ bool is_vista = false;
+
+ BUG_ON(!data || !ph);
+ if (MAGIC_PRIVHEAD != get_unaligned_be64(data)) {
+ ldm_error("Cannot find PRIVHEAD structure. LDM database is"
+ " corrupt. Aborting.");
+ return false;
+ }
+ ph->ver_major = get_unaligned_be16(data + 0x000C);
+ ph->ver_minor = get_unaligned_be16(data + 0x000E);
+ ph->logical_disk_start = get_unaligned_be64(data + 0x011B);
+ ph->logical_disk_size = get_unaligned_be64(data + 0x0123);
+ ph->config_start = get_unaligned_be64(data + 0x012B);
+ ph->config_size = get_unaligned_be64(data + 0x0133);
+ /* Version 2.11 is Win2k/XP and version 2.12 is Vista. */
+ if (ph->ver_major == 2 && ph->ver_minor == 12)
+ is_vista = true;
+ if (!is_vista && (ph->ver_major != 2 || ph->ver_minor != 11)) {
+ ldm_error("Expected PRIVHEAD version 2.11 or 2.12, got %d.%d."
+ " Aborting.", ph->ver_major, ph->ver_minor);
+ return false;
+ }
+ ldm_debug("PRIVHEAD version %d.%d (Windows %s).", ph->ver_major,
+ ph->ver_minor, is_vista ? "Vista" : "2000/XP");
+ if (ph->config_size != LDM_DB_SIZE) { /* 1 MiB in sectors. */
+ /* Warn the user and continue, carefully. */
+ ldm_info("Database is normally %u bytes, it claims to "
+ "be %llu bytes.", LDM_DB_SIZE,
+ (unsigned long long)ph->config_size);
+ }
+ if ((ph->logical_disk_size == 0) || (ph->logical_disk_start +
+ ph->logical_disk_size > ph->config_start)) {
+ ldm_error("PRIVHEAD disk size doesn't match real disk size");
+ return false;
+ }
+ if (uuid_parse(data + 0x0030, &ph->disk_id)) {
+ ldm_error("PRIVHEAD contains an invalid GUID.");
+ return false;
+ }
+ ldm_debug("Parsed PRIVHEAD successfully.");
+ return true;
+}
+
+/**
+ * ldm_parse_tocblock - Read the LDM Database TOCBLOCK structure
+ * @data: Raw database TOCBLOCK structure loaded from the device
+ * @toc: In-memory toc structure in which to return parsed information
+ *
+ * This parses the LDM Database TOCBLOCK (table of contents) structure supplied
+ * in @data and sets up the in-memory tocblock structure @toc with the obtained
+ * information.
+ *
+ * N.B. The *_start and *_size values returned in @toc are not range-checked.
+ *
+ * Return: 'true' @toc contains the TOCBLOCK data
+ * 'false' @toc contents are undefined
+ */
+static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc)
+{
+ BUG_ON (!data || !toc);
+
+ if (MAGIC_TOCBLOCK != get_unaligned_be64(data)) {
+ ldm_crit ("Cannot find TOCBLOCK, database may be corrupt.");
+ return false;
+ }
+ strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
+ toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0;
+ toc->bitmap1_start = get_unaligned_be64(data + 0x2E);
+ toc->bitmap1_size = get_unaligned_be64(data + 0x36);
+
+ if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
+ sizeof (toc->bitmap1_name)) != 0) {
+ ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
+ TOC_BITMAP1, toc->bitmap1_name);
+ return false;
+ }
+ strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
+ toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0;
+ toc->bitmap2_start = get_unaligned_be64(data + 0x50);
+ toc->bitmap2_size = get_unaligned_be64(data + 0x58);
+ if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
+ sizeof (toc->bitmap2_name)) != 0) {
+ ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
+ TOC_BITMAP2, toc->bitmap2_name);
+ return false;
+ }
+ ldm_debug ("Parsed TOCBLOCK successfully.");
+ return true;
+}
+
+/**
+ * ldm_parse_vmdb - Read the LDM Database VMDB structure
+ * @data: Raw database VMDB structure loaded from the device
+ * @vm: In-memory vmdb structure in which to return parsed information
+ *
+ * This parses the LDM Database VMDB structure supplied in @data and sets up
+ * the in-memory vmdb structure @vm with the obtained information.
+ *
+ * N.B. The *_start, *_size and *_seq values will be range-checked later.
+ *
+ * Return: 'true' @vm contains VMDB info
+ * 'false' @vm contents are undefined
+ */
+static bool ldm_parse_vmdb (const u8 *data, struct vmdb *vm)
+{
+ BUG_ON (!data || !vm);
+
+ if (MAGIC_VMDB != get_unaligned_be32(data)) {
+ ldm_crit ("Cannot find the VMDB, database may be corrupt.");
+ return false;
+ }
+
+ vm->ver_major = get_unaligned_be16(data + 0x12);
+ vm->ver_minor = get_unaligned_be16(data + 0x14);
+ if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
+ ldm_error ("Expected VMDB version %d.%d, got %d.%d. "
+ "Aborting.", 4, 10, vm->ver_major, vm->ver_minor);
+ return false;
+ }
+
+ vm->vblk_size = get_unaligned_be32(data + 0x08);
+ if (vm->vblk_size == 0) {
+ ldm_error ("Illegal VBLK size");
+ return false;
+ }
+
+ vm->vblk_offset = get_unaligned_be32(data + 0x0C);
+ vm->last_vblk_seq = get_unaligned_be32(data + 0x04);
+
+ ldm_debug ("Parsed VMDB successfully.");
+ return true;
+}
+
+/**
+ * ldm_compare_privheads - Compare two privhead objects
+ * @ph1: First privhead
+ * @ph2: Second privhead
+ *
+ * This compares the two privhead structures @ph1 and @ph2.
+ *
+ * Return: 'true' Identical
+ * 'false' Different
+ */
+static bool ldm_compare_privheads (const struct privhead *ph1,
+ const struct privhead *ph2)
+{
+ BUG_ON (!ph1 || !ph2);
+
+ return ((ph1->ver_major == ph2->ver_major) &&
+ (ph1->ver_minor == ph2->ver_minor) &&
+ (ph1->logical_disk_start == ph2->logical_disk_start) &&
+ (ph1->logical_disk_size == ph2->logical_disk_size) &&
+ (ph1->config_start == ph2->config_start) &&
+ (ph1->config_size == ph2->config_size) &&
+ uuid_equal(&ph1->disk_id, &ph2->disk_id));
+}
+
+/**
+ * ldm_compare_tocblocks - Compare two tocblock objects
+ * @toc1: First toc
+ * @toc2: Second toc
+ *
+ * This compares the two tocblock structures @toc1 and @toc2.
+ *
+ * Return: 'true' Identical
+ * 'false' Different
+ */
+static bool ldm_compare_tocblocks (const struct tocblock *toc1,
+ const struct tocblock *toc2)
+{
+ BUG_ON (!toc1 || !toc2);
+
+ return ((toc1->bitmap1_start == toc2->bitmap1_start) &&
+ (toc1->bitmap1_size == toc2->bitmap1_size) &&
+ (toc1->bitmap2_start == toc2->bitmap2_start) &&
+ (toc1->bitmap2_size == toc2->bitmap2_size) &&
+ !strncmp (toc1->bitmap1_name, toc2->bitmap1_name,
+ sizeof (toc1->bitmap1_name)) &&
+ !strncmp (toc1->bitmap2_name, toc2->bitmap2_name,
+ sizeof (toc1->bitmap2_name)));
+}
+
+/**
+ * ldm_validate_privheads - Compare the primary privhead with its backups
+ * @state: Partition check state including device holding the LDM Database
+ * @ph1: Memory struct to fill with ph contents
+ *
+ * Read and compare all three privheads from disk.
+ *
+ * The privheads on disk show the size and location of the main disk area and
+ * the configuration area (the database). The values are range-checked against
+ * @hd, which contains the real size of the disk.
+ *
+ * Return: 'true' Success
+ * 'false' Error
+ */
+static bool ldm_validate_privheads(struct parsed_partitions *state,
+ struct privhead *ph1)
+{
+ static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
+ struct privhead *ph[3] = { ph1 };
+ Sector sect;
+ u8 *data;
+ bool result = false;
+ long num_sects;
+ int i;
+
+ BUG_ON (!state || !ph1);
+
+ ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
+ ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
+ if (!ph[1] || !ph[2]) {
+ ldm_crit ("Out of memory.");
+ goto out;
+ }
+
+ /* off[1 & 2] are relative to ph[0]->config_start */
+ ph[0]->config_start = 0;
+
+ /* Read and parse privheads */
+ for (i = 0; i < 3; i++) {
+ data = read_part_sector(state, ph[0]->config_start + off[i],
+ §);
+ if (!data) {
+ ldm_crit ("Disk read failed.");
+ goto out;
+ }
+ result = ldm_parse_privhead (data, ph[i]);
+ put_dev_sector (sect);
+ if (!result) {
+ ldm_error ("Cannot find PRIVHEAD %d.", i+1); /* Log again */
+ if (i < 2)
+ goto out; /* Already logged */
+ else
+ break; /* FIXME ignore for now, 3rd PH can fail on odd-sized disks */
+ }
+ }
+
+ num_sects = state->bdev->bd_inode->i_size >> 9;
+
+ if ((ph[0]->config_start > num_sects) ||
+ ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
+ ldm_crit ("Database extends beyond the end of the disk.");
+ goto out;
+ }
+
+ if ((ph[0]->logical_disk_start > ph[0]->config_start) ||
+ ((ph[0]->logical_disk_start + ph[0]->logical_disk_size)
+ > ph[0]->config_start)) {
+ ldm_crit ("Disk and database overlap.");
+ goto out;
+ }
+
+ if (!ldm_compare_privheads (ph[0], ph[1])) {
+ ldm_crit ("Primary and backup PRIVHEADs don't match.");
+ goto out;
+ }
+ /* FIXME ignore this for now
+ if (!ldm_compare_privheads (ph[0], ph[2])) {
+ ldm_crit ("Primary and backup PRIVHEADs don't match.");
+ goto out;
+ }*/
+ ldm_debug ("Validated PRIVHEADs successfully.");
+ result = true;
+out:
+ kfree (ph[1]);
+ kfree (ph[2]);
+ return result;
+}
+
+/**
+ * ldm_validate_tocblocks - Validate the table of contents and its backups
+ * @state: Partition check state including device holding the LDM Database
+ * @base: Offset, into @state->bdev, of the database
+ * @ldb: Cache of the database structures
+ *
+ * Find and compare the four tables of contents of the LDM Database stored on
+ * @state->bdev and return the parsed information into @toc1.
+ *
+ * The offsets and sizes of the configs are range-checked against a privhead.
+ *
+ * Return: 'true' @toc1 contains validated TOCBLOCK info
+ * 'false' @toc1 contents are undefined
+ */
+static bool ldm_validate_tocblocks(struct parsed_partitions *state,
+ unsigned long base, struct ldmdb *ldb)
+{
+ static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
+ struct tocblock *tb[4];
+ struct privhead *ph;
+ Sector sect;
+ u8 *data;
+ int i, nr_tbs;
+ bool result = false;
+
+ BUG_ON(!state || !ldb);
+ ph = &ldb->ph;
+ tb[0] = &ldb->toc;
+ tb[1] = kmalloc(sizeof(*tb[1]) * 3, GFP_KERNEL);
+ if (!tb[1]) {
+ ldm_crit("Out of memory.");
+ goto err;
+ }
+ tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
+ tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
+ /*
+ * Try to read and parse all four TOCBLOCKs.
+ *
+ * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
+ * skip any that fail as long as we get at least one valid TOCBLOCK.
+ */
+ for (nr_tbs = i = 0; i < 4; i++) {
+ data = read_part_sector(state, base + off[i], §);
+ if (!data) {
+ ldm_error("Disk read failed for TOCBLOCK %d.", i);
+ continue;
+ }
+ if (ldm_parse_tocblock(data, tb[nr_tbs]))
+ nr_tbs++;
+ put_dev_sector(sect);
+ }
+ if (!nr_tbs) {
+ ldm_crit("Failed to find a valid TOCBLOCK.");
+ goto err;
+ }
+ /* Range check the TOCBLOCK against a privhead. */
+ if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
+ ((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
+ ph->config_size)) {
+ ldm_crit("The bitmaps are out of range. Giving up.");
+ goto err;
+ }
+ /* Compare all loaded TOCBLOCKs. */
+ for (i = 1; i < nr_tbs; i++) {
+ if (!ldm_compare_tocblocks(tb[0], tb[i])) {
+ ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
+ goto err;
+ }
+ }
+ ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
+ result = true;
+err:
+ kfree(tb[1]);
+ return result;
+}
+
+/**
+ * ldm_validate_vmdb - Read the VMDB and validate it
+ * @state: Partition check state including device holding the LDM Database
+ * @base: Offset, into @bdev, of the database
+ * @ldb: Cache of the database structures
+ *
+ * Find the vmdb of the LDM Database stored on @bdev and return the parsed
+ * information in @ldb.
+ *
+ * Return: 'true' @ldb contains validated VBDB info
+ * 'false' @ldb contents are undefined
+ */
+static bool ldm_validate_vmdb(struct parsed_partitions *state,
+ unsigned long base, struct ldmdb *ldb)
+{
+ Sector sect;
+ u8 *data;
+ bool result = false;
+ struct vmdb *vm;
+ struct tocblock *toc;
+
+ BUG_ON (!state || !ldb);
+
+ vm = &ldb->vm;
+ toc = &ldb->toc;
+
+ data = read_part_sector(state, base + OFF_VMDB, §);
+ if (!data) {
+ ldm_crit ("Disk read failed.");
+ return false;
+ }
+
+ if (!ldm_parse_vmdb (data, vm))
+ goto out; /* Already logged */
+
+ /* Are there uncommitted transactions? */
+ if (get_unaligned_be16(data + 0x10) != 0x01) {
+ ldm_crit ("Database is not in a consistent state. Aborting.");
+ goto out;
+ }
+
+ if (vm->vblk_offset != 512)
+ ldm_info ("VBLKs start at offset 0x%04x.", vm->vblk_offset);
+
+ /*
+ * The last_vblkd_seq can be before the end of the vmdb, just make sure
+ * it is not out of bounds.
+ */
+ if ((vm->vblk_size * vm->last_vblk_seq) > (toc->bitmap1_size << 9)) {
+ ldm_crit ("VMDB exceeds allowed size specified by TOCBLOCK. "
+ "Database is corrupt. Aborting.");
+ goto out;
+ }
+
+ result = true;
+out:
+ put_dev_sector (sect);
+ return result;
+}
+
+
+/**
+ * ldm_validate_partition_table - Determine whether bdev might be a dynamic disk
+ * @state: Partition check state including device holding the LDM Database
+ *
+ * This function provides a weak test to decide whether the device is a dynamic
+ * disk or not. It looks for an MS-DOS-style partition table containing at
+ * least one partition of type 0x42 (formerly SFS, now used by Windows for
+ * dynamic disks).
+ *
+ * N.B. The only possible error can come from the read_part_sector and that is
+ * only likely to happen if the underlying device is strange. If that IS
+ * the case we should return zero to let someone else try.
+ *
+ * Return: 'true' @state->bdev is a dynamic disk
+ * 'false' @state->bdev is not a dynamic disk, or an error occurred
+ */
+static bool ldm_validate_partition_table(struct parsed_partitions *state)
+{
+ Sector sect;
+ u8 *data;
+ struct partition *p;
+ int i;
+ bool result = false;
+
+ BUG_ON(!state);
+
+ data = read_part_sector(state, 0, §);
+ if (!data) {
+ ldm_info ("Disk read failed.");
+ return false;
+ }
+
+ if (*(__le16*) (data + 0x01FE) != cpu_to_le16 (MSDOS_LABEL_MAGIC))
+ goto out;
+
+ p = (struct partition*)(data + 0x01BE);
+ for (i = 0; i < 4; i++, p++)
+ if (SYS_IND (p) == LDM_PARTITION) {
+ result = true;
+ break;
+ }
+
+ if (result)
+ ldm_debug ("Found W2K dynamic disk partition type.");
+
+out:
+ put_dev_sector (sect);
+ return result;
+}
+
+/**
+ * ldm_get_disk_objid - Search a linked list of vblk's for a given Disk Id
+ * @ldb: Cache of the database structures
+ *
+ * The LDM Database contains a list of all partitions on all dynamic disks.
+ * The primary PRIVHEAD, at the beginning of the physical disk, tells us
+ * the GUID of this disk. This function searches for the GUID in a linked
+ * list of vblk's.
+ *
+ * Return: Pointer, A matching vblk was found
+ * NULL, No match, or an error
+ */
+static struct vblk * ldm_get_disk_objid (const struct ldmdb *ldb)
+{
+ struct list_head *item;
+
+ BUG_ON (!ldb);
+
+ list_for_each (item, &ldb->v_disk) {
+ struct vblk *v = list_entry (item, struct vblk, list);
+ if (uuid_equal(&v->vblk.disk.disk_id, &ldb->ph.disk_id))
+ return v;
+ }
+
+ return NULL;
+}
+
+/**
+ * ldm_create_data_partitions - Create data partitions for this device
+ * @pp: List of the partitions parsed so far
+ * @ldb: Cache of the database structures
+ *
+ * The database contains ALL the partitions for ALL disk groups, so we need to
+ * filter out this specific disk. Using the disk's object id, we can find all
+ * the partitions in the database that belong to this disk.
+ *
+ * Add each partition in our database, to the parsed_partitions structure.
+ *
+ * N.B. This function creates the partitions in the order it finds partition
+ * objects in the linked list.
+ *
+ * Return: 'true' Partition created
+ * 'false' Error, probably a range checking problem
+ */
+static bool ldm_create_data_partitions (struct parsed_partitions *pp,
+ const struct ldmdb *ldb)
+{
+ struct list_head *item;
+ struct vblk *vb;
+ struct vblk *disk;
+ struct vblk_part *part;
+ int part_num = 1;
+
+ BUG_ON (!pp || !ldb);
+
+ disk = ldm_get_disk_objid (ldb);
+ if (!disk) {
+ ldm_crit ("Can't find the ID of this disk in the database.");
+ return false;
+ }
+
+ strlcat(pp->pp_buf, " [LDM]", PAGE_SIZE);
+
+ /* Create the data partitions */
+ list_for_each (item, &ldb->v_part) {
+ vb = list_entry (item, struct vblk, list);
+ part = &vb->vblk.part;
+
+ if (part->disk_id != disk->obj_id)
+ continue;
+
+ put_partition (pp, part_num, ldb->ph.logical_disk_start +
+ part->start, part->size);
+ part_num++;
+ }
+
+ strlcat(pp->pp_buf, "\n", PAGE_SIZE);
+ return true;
+}
+
+
+/**
+ * ldm_relative - Calculate the next relative offset
+ * @buffer: Block of data being worked on
+ * @buflen: Size of the block of data
+ * @base: Size of the previous fixed width fields
+ * @offset: Cumulative size of the previous variable-width fields
+ *
+ * Because many of the VBLK fields are variable-width, it's necessary
+ * to calculate each offset based on the previous one and the length
+ * of the field it pointed to.
+ *
+ * Return: -1 Error, the calculated offset exceeded the size of the buffer
+ * n OK, a range-checked offset into buffer
+ */
+static int ldm_relative(const u8 *buffer, int buflen, int base, int offset)
+{
+
+ base += offset;
+ if (!buffer || offset < 0 || base > buflen) {
+ if (!buffer)
+ ldm_error("!buffer");
+ if (offset < 0)
+ ldm_error("offset (%d) < 0", offset);
+ if (base > buflen)
+ ldm_error("base (%d) > buflen (%d)", base, buflen);
+ return -1;
+ }
+ if (base + buffer[base] >= buflen) {
+ ldm_error("base (%d) + buffer[base] (%d) >= buflen (%d)", base,
+ buffer[base], buflen);
+ return -1;
+ }
+ return buffer[base] + offset + 1;
+}
+
+/**
+ * ldm_get_vnum - Convert a variable-width, big endian number, into cpu order
+ * @block: Pointer to the variable-width number to convert
+ *
+ * Large numbers in the LDM Database are often stored in a packed format. Each
+ * number is prefixed by a one byte width marker. All numbers in the database
+ * are stored in big-endian byte order. This function reads one of these
+ * numbers and returns the result
+ *
+ * N.B. This function DOES NOT perform any range checking, though the most
+ * it will read is eight bytes.
+ *
+ * Return: n A number
+ * 0 Zero, or an error occurred
+ */
+static u64 ldm_get_vnum (const u8 *block)
+{
+ u64 tmp = 0;
+ u8 length;
+
+ BUG_ON (!block);
+
+ length = *block++;
+
+ if (length && length <= 8)
+ while (length--)
+ tmp = (tmp << 8) | *block++;
+ else
+ ldm_error ("Illegal length %d.", length);
+
+ return tmp;
+}
+
+/**
+ * ldm_get_vstr - Read a length-prefixed string into a buffer
+ * @block: Pointer to the length marker
+ * @buffer: Location to copy string to
+ * @buflen: Size of the output buffer
+ *
+ * Many of the strings in the LDM Database are not NULL terminated. Instead
+ * they are prefixed by a one byte length marker. This function copies one of
+ * these strings into a buffer.
+ *
+ * N.B. This function DOES NOT perform any range checking on the input.
+ * If the buffer is too small, the output will be truncated.
+ *
+ * Return: 0, Error and @buffer contents are undefined
+ * n, String length in characters (excluding NULL)
+ * buflen-1, String was truncated.
+ */
+static int ldm_get_vstr (const u8 *block, u8 *buffer, int buflen)
+{
+ int length;
+
+ BUG_ON (!block || !buffer);
+
+ length = block[0];
+ if (length >= buflen) {
+ ldm_error ("Truncating string %d -> %d.", length, buflen);
+ length = buflen - 1;
+ }
+ memcpy (buffer, block + 1, length);
+ buffer[length] = 0;
+ return length;
+}
+
+
+/**
+ * ldm_parse_cmp3 - Read a raw VBLK Component object into a vblk structure
+ * @buffer: Block of data being worked on
+ * @buflen: Size of the block of data
+ * @vb: In-memory vblk in which to return information
+ *
+ * Read a raw VBLK Component object (version 3) into a vblk structure.
+ *
+ * Return: 'true' @vb contains a Component VBLK
+ * 'false' @vb contents are not defined
+ */
+static bool ldm_parse_cmp3 (const u8 *buffer, int buflen, struct vblk *vb)
+{
+ int r_objid, r_name, r_vstate, r_child, r_parent, r_stripe, r_cols, len;
+ struct vblk_comp *comp;
+
+ BUG_ON (!buffer || !vb);
+
+ r_objid = ldm_relative (buffer, buflen, 0x18, 0);
+ r_name = ldm_relative (buffer, buflen, 0x18, r_objid);
+ r_vstate = ldm_relative (buffer, buflen, 0x18, r_name);
+ r_child = ldm_relative (buffer, buflen, 0x1D, r_vstate);
+ r_parent = ldm_relative (buffer, buflen, 0x2D, r_child);
+
+ if (buffer[0x12] & VBLK_FLAG_COMP_STRIPE) {
+ r_stripe = ldm_relative (buffer, buflen, 0x2E, r_parent);
+ r_cols = ldm_relative (buffer, buflen, 0x2E, r_stripe);
+ len = r_cols;
+ } else {
+ r_stripe = 0;
+ r_cols = 0;
+ len = r_parent;
+ }
+ if (len < 0)
+ return false;
+
+ len += VBLK_SIZE_CMP3;
+ if (len != get_unaligned_be32(buffer + 0x14))
+ return false;
+
+ comp = &vb->vblk.comp;
+ ldm_get_vstr (buffer + 0x18 + r_name, comp->state,
+ sizeof (comp->state));
+ comp->type = buffer[0x18 + r_vstate];
+ comp->children = ldm_get_vnum (buffer + 0x1D + r_vstate);
+ comp->parent_id = ldm_get_vnum (buffer + 0x2D + r_child);
+ comp->chunksize = r_stripe ? ldm_get_vnum (buffer+r_parent+0x2E) : 0;
+
+ return true;
+}
+
+/**
+ * ldm_parse_dgr3 - Read a raw VBLK Disk Group object into a vblk structure
+ * @buffer: Block of data being worked on
+ * @buflen: Size of the block of data
+ * @vb: In-memory vblk in which to return information
+ *
+ * Read a raw VBLK Disk Group object (version 3) into a vblk structure.
+ *
+ * Return: 'true' @vb contains a Disk Group VBLK
+ * 'false' @vb contents are not defined
+ */
+static int ldm_parse_dgr3 (const u8 *buffer, int buflen, struct vblk *vb)
+{
+ int r_objid, r_name, r_diskid, r_id1, r_id2, len;
+ struct vblk_dgrp *dgrp;
+
+ BUG_ON (!buffer || !vb);
+
+ r_objid = ldm_relative (buffer, buflen, 0x18, 0);
+ r_name = ldm_relative (buffer, buflen, 0x18, r_objid);
+ r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);
+
+ if (buffer[0x12] & VBLK_FLAG_DGR3_IDS) {
+ r_id1 = ldm_relative (buffer, buflen, 0x24, r_diskid);
+ r_id2 = ldm_relative (buffer, buflen, 0x24, r_id1);
+ len = r_id2;
+ } else {
+ r_id1 = 0;
+ r_id2 = 0;
+ len = r_diskid;
+ }
+ if (len < 0)
+ return false;
+
+ len += VBLK_SIZE_DGR3;
+ if (len != get_unaligned_be32(buffer + 0x14))
+ return false;
+
+ dgrp = &vb->vblk.dgrp;
+ ldm_get_vstr (buffer + 0x18 + r_name, dgrp->disk_id,
+ sizeof (dgrp->disk_id));
+ return true;
+}
+
+/**
+ * ldm_parse_dgr4 - Read a raw VBLK Disk Group object into a vblk structure
+ * @buffer: Block of data being worked on
+ * @buflen: Size of the block of data
+ * @vb: In-memory vblk in which to return information
+ *
+ * Read a raw VBLK Disk Group object (version 4) into a vblk structure.
+ *
+ * Return: 'true' @vb contains a Disk Group VBLK
+ * 'false' @vb contents are not defined
+ */
+static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
+{
+ char buf[64];
+ int r_objid, r_name, r_id1, r_id2, len;
+ struct vblk_dgrp *dgrp;
+
+ BUG_ON (!buffer || !vb);
+
+ r_objid = ldm_relative (buffer, buflen, 0x18, 0);
+ r_name = ldm_relative (buffer, buflen, 0x18, r_objid);
+
+ if (buffer[0x12] & VBLK_FLAG_DGR4_IDS) {
+ r_id1 = ldm_relative (buffer, buflen, 0x44, r_name);
+ r_id2 = ldm_relative (buffer, buflen, 0x44, r_id1);
+ len = r_id2;
+ } else {
+ r_id1 = 0;
+ r_id2 = 0;
+ len = r_name;
+ }
+ if (len < 0)
+ return false;
+
+ len += VBLK_SIZE_DGR4;
+ if (len != get_unaligned_be32(buffer + 0x14))
+ return false;
+
+ dgrp = &vb->vblk.dgrp;
+
+ ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
+ return true;
+}
+
+/**
+ * ldm_parse_dsk3 - Read a raw VBLK Disk object into a vblk structure
+ * @buffer: Block of data being worked on
+ * @buflen: Size of the block of data
+ * @vb: In-memory vblk in which to return information
+ *
+ * Read a raw VBLK Disk object (version 3) into a vblk structure.
+ *
+ * Return: 'true' @vb contains a Disk VBLK
+ * 'false' @vb contents are not defined
+ */
+static bool ldm_parse_dsk3 (const u8 *buffer, int buflen, struct vblk *vb)
+{
+ int r_objid, r_name, r_diskid, r_altname, len;
+ struct vblk_disk *disk;
+
+ BUG_ON (!buffer || !vb);
+
+ r_objid = ldm_relative (buffer, buflen, 0x18, 0);
+ r_name = ldm_relative (buffer, buflen, 0x18, r_objid);
+ r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);
+ r_altname = ldm_relative (buffer, buflen, 0x18, r_diskid);
+ len = r_altname;
+ if (len < 0)
+ return false;
+
+ len += VBLK_SIZE_DSK3;
+ if (len != get_unaligned_be32(buffer + 0x14))
+ return false;
+
+ disk = &vb->vblk.disk;
+ ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
+ sizeof (disk->alt_name));
+ if (uuid_parse(buffer + 0x19 + r_name, &disk->disk_id))
+ return false;
+
+ return true;
+}
+
+/**
+ * ldm_parse_dsk4 - Read a raw VBLK Disk object into a vblk structure
+ * @buffer: Block of data being worked on
+ * @buflen: Size of the block of data
+ * @vb: In-memory vblk in which to return information
+ *
+ * Read a raw VBLK Disk object (version 4) into a vblk structure.
+ *
+ * Return: 'true' @vb contains a Disk VBLK
+ * 'false' @vb contents are not defined
+ */
+static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
+{
+ int r_objid, r_name, len;
+ struct vblk_disk *disk;
+
+ BUG_ON (!buffer || !vb);
+
+ r_objid = ldm_relative (buffer, buflen, 0x18, 0);
+ r_name = ldm_relative (buffer, buflen, 0x18, r_objid);
+ len = r_name;
+ if (len < 0)
+ return false;
+
+ len += VBLK_SIZE_DSK4;
+ if (len != get_unaligned_be32(buffer + 0x14))
+ return false;
+
+ disk = &vb->vblk.disk;
+ uuid_copy(&disk->disk_id, (uuid_t *)(buffer + 0x18 + r_name));
+ return true;
+}
+
+/**
+ * ldm_parse_prt3 - Read a raw VBLK Partition object into a vblk structure
+ * @buffer: Block of data being worked on
+ * @buflen: Size of the block of data
+ * @vb: In-memory vblk in which to return information
+ *
+ * Read a raw VBLK Partition object (version 3) into a vblk structure.
+ *
+ * Return: 'true' @vb contains a Partition VBLK
+ * 'false' @vb contents are not defined
+ */
+static bool ldm_parse_prt3(const u8 *buffer, int buflen, struct vblk *vb)
+{
+ int r_objid, r_name, r_size, r_parent, r_diskid, r_index, len;
+ struct vblk_part *part;
+
+ BUG_ON(!buffer || !vb);
+ r_objid = ldm_relative(buffer, buflen, 0x18, 0);
+ if (r_objid < 0) {
+ ldm_error("r_objid %d < 0", r_objid);
+ return false;
+ }
+ r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
+ if (r_name < 0) {
+ ldm_error("r_name %d < 0", r_name);
+ return false;
+ }
+ r_size = ldm_relative(buffer, buflen, 0x34, r_name);
+ if (r_size < 0) {
+ ldm_error("r_size %d < 0", r_size);
+ return false;
+ }
+ r_parent = ldm_relative(buffer, buflen, 0x34, r_size);
+ if (r_parent < 0) {
+ ldm_error("r_parent %d < 0", r_parent);
+ return false;
+ }
+ r_diskid = ldm_relative(buffer, buflen, 0x34, r_parent);
+ if (r_diskid < 0) {
+ ldm_error("r_diskid %d < 0", r_diskid);
+ return false;
+ }
+ if (buffer[0x12] & VBLK_FLAG_PART_INDEX) {
+ r_index = ldm_relative(buffer, buflen, 0x34, r_diskid);
+ if (r_index < 0) {
+ ldm_error("r_index %d < 0", r_index);
+ return false;
+ }
+ len = r_index;
+ } else {
+ r_index = 0;
+ len = r_diskid;
+ }
+ if (len < 0) {
+ ldm_error("len %d < 0", len);
+ return false;
+ }
+ len += VBLK_SIZE_PRT3;
+ if (len > get_unaligned_be32(buffer + 0x14)) {
+ ldm_error("len %d > BE32(buffer + 0x14) %d", len,
+ get_unaligned_be32(buffer + 0x14));
+ return false;
+ }
+ part = &vb->vblk.part;
+ part->start = get_unaligned_be64(buffer + 0x24 + r_name);
+ part->volume_offset = get_unaligned_be64(buffer + 0x2C + r_name);
+ part->size = ldm_get_vnum(buffer + 0x34 + r_name);
+ part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
+ part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
+ if (vb->flags & VBLK_FLAG_PART_INDEX)
+ part->partnum = buffer[0x35 + r_diskid];
+ else
+ part->partnum = 0;
+ return true;
+}
+
+/**
+ * ldm_parse_vol5 - Read a raw VBLK Volume object into a vblk structure
+ * @buffer: Block of data being worked on
+ * @buflen: Size of the block of data
+ * @vb: In-memory vblk in which to return information
+ *
+ * Read a raw VBLK Volume object (version 5) into a vblk structure.
+ *
+ * Return: 'true' @vb contains a Volume VBLK
+ * 'false' @vb contents are not defined
+ */
+static bool ldm_parse_vol5(const u8 *buffer, int buflen, struct vblk *vb)
+{
+ int r_objid, r_name, r_vtype, r_disable_drive_letter, r_child, r_size;
+ int r_id1, r_id2, r_size2, r_drive, len;
+ struct vblk_volu *volu;
+
+ BUG_ON(!buffer || !vb);
+ r_objid = ldm_relative(buffer, buflen, 0x18, 0);
+ if (r_objid < 0) {
+ ldm_error("r_objid %d < 0", r_objid);
+ return false;
+ }
+ r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
+ if (r_name < 0) {
+ ldm_error("r_name %d < 0", r_name);
+ return false;
+ }
+ r_vtype = ldm_relative(buffer, buflen, 0x18, r_name);
+ if (r_vtype < 0) {
+ ldm_error("r_vtype %d < 0", r_vtype);
+ return false;
+ }
+ r_disable_drive_letter = ldm_relative(buffer, buflen, 0x18, r_vtype);
+ if (r_disable_drive_letter < 0) {
+ ldm_error("r_disable_drive_letter %d < 0",
+ r_disable_drive_letter);
+ return false;
+ }
+ r_child = ldm_relative(buffer, buflen, 0x2D, r_disable_drive_letter);
+ if (r_child < 0) {
+ ldm_error("r_child %d < 0", r_child);
+ return false;
+ }
+ r_size = ldm_relative(buffer, buflen, 0x3D, r_child);
+ if (r_size < 0) {
+ ldm_error("r_size %d < 0", r_size);
+ return false;
+ }
+ if (buffer[0x12] & VBLK_FLAG_VOLU_ID1) {
+ r_id1 = ldm_relative(buffer, buflen, 0x52, r_size);
+ if (r_id1 < 0) {
+ ldm_error("r_id1 %d < 0", r_id1);
+ return false;
+ }
+ } else
+ r_id1 = r_size;
+ if (buffer[0x12] & VBLK_FLAG_VOLU_ID2) {
+ r_id2 = ldm_relative(buffer, buflen, 0x52, r_id1);
+ if (r_id2 < 0) {
+ ldm_error("r_id2 %d < 0", r_id2);
+ return false;
+ }
+ } else
+ r_id2 = r_id1;
+ if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE) {
+ r_size2 = ldm_relative(buffer, buflen, 0x52, r_id2);
+ if (r_size2 < 0) {
+ ldm_error("r_size2 %d < 0", r_size2);
+ return false;
+ }
+ } else
+ r_size2 = r_id2;
+ if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
+ r_drive = ldm_relative(buffer, buflen, 0x52, r_size2);
+ if (r_drive < 0) {
+ ldm_error("r_drive %d < 0", r_drive);
+ return false;
+ }
+ } else
+ r_drive = r_size2;
+ len = r_drive;
+ if (len < 0) {
+ ldm_error("len %d < 0", len);
+ return false;
+ }
+ len += VBLK_SIZE_VOL5;
+ if (len > get_unaligned_be32(buffer + 0x14)) {
+ ldm_error("len %d > BE32(buffer + 0x14) %d", len,
+ get_unaligned_be32(buffer + 0x14));
+ return false;
+ }
+ volu = &vb->vblk.volu;
+ ldm_get_vstr(buffer + 0x18 + r_name, volu->volume_type,
+ sizeof(volu->volume_type));
+ memcpy(volu->volume_state, buffer + 0x18 + r_disable_drive_letter,
+ sizeof(volu->volume_state));
+ volu->size = ldm_get_vnum(buffer + 0x3D + r_child);
+ volu->partition_type = buffer[0x41 + r_size];
+ memcpy(volu->guid, buffer + 0x42 + r_size, sizeof(volu->guid));
+ if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
+ ldm_get_vstr(buffer + 0x52 + r_size, volu->drive_hint,
+ sizeof(volu->drive_hint));
+ }
+ return true;
+}
+
+/**
+ * ldm_parse_vblk - Read a raw VBLK object into a vblk structure
+ * @buf: Block of data being worked on
+ * @len: Size of the block of data
+ * @vb: In-memory vblk in which to return information
+ *
+ * Read a raw VBLK object into a vblk structure. This function just reads the
+ * information common to all VBLK types, then delegates the rest of the work to
+ * helper functions: ldm_parse_*.
+ *
+ * Return: 'true' @vb contains a VBLK
+ * 'false' @vb contents are not defined
+ */
+static bool ldm_parse_vblk (const u8 *buf, int len, struct vblk *vb)
+{
+ bool result = false;
+ int r_objid;
+
+ BUG_ON (!buf || !vb);
+
+ r_objid = ldm_relative (buf, len, 0x18, 0);
+ if (r_objid < 0) {
+ ldm_error ("VBLK header is corrupt.");
+ return false;
+ }
+
+ vb->flags = buf[0x12];
+ vb->type = buf[0x13];
+ vb->obj_id = ldm_get_vnum (buf + 0x18);
+ ldm_get_vstr (buf+0x18+r_objid, vb->name, sizeof (vb->name));
+
+ switch (vb->type) {
+ case VBLK_CMP3: result = ldm_parse_cmp3 (buf, len, vb); break;
+ case VBLK_DSK3: result = ldm_parse_dsk3 (buf, len, vb); break;
+ case VBLK_DSK4: result = ldm_parse_dsk4 (buf, len, vb); break;
+ case VBLK_DGR3: result = ldm_parse_dgr3 (buf, len, vb); break;
+ case VBLK_DGR4: result = ldm_parse_dgr4 (buf, len, vb); break;
+ case VBLK_PRT3: result = ldm_parse_prt3 (buf, len, vb); break;
+ case VBLK_VOL5: result = ldm_parse_vol5 (buf, len, vb); break;
+ }
+
+ if (result)
+ ldm_debug ("Parsed VBLK 0x%llx (type: 0x%02x) ok.",
+ (unsigned long long) vb->obj_id, vb->type);
+ else
+ ldm_error ("Failed to parse VBLK 0x%llx (type: 0x%02x).",
+ (unsigned long long) vb->obj_id, vb->type);
+
+ return result;
+}
+
+
+/**
+ * ldm_ldmdb_add - Adds a raw VBLK entry to the ldmdb database
+ * @data: Raw VBLK to add to the database
+ * @len: Size of the raw VBLK
+ * @ldb: Cache of the database structures
+ *
+ * The VBLKs are sorted into categories. Partitions are also sorted by offset.
+ *
+ * N.B. This function does not check the validity of the VBLKs.
+ *
+ * Return: 'true' The VBLK was added
+ * 'false' An error occurred
+ */
+static bool ldm_ldmdb_add (u8 *data, int len, struct ldmdb *ldb)
+{
+ struct vblk *vb;
+ struct list_head *item;
+
+ BUG_ON (!data || !ldb);
+
+ vb = kmalloc (sizeof (*vb), GFP_KERNEL);
+ if (!vb) {
+ ldm_crit ("Out of memory.");
+ return false;
+ }
+
+ if (!ldm_parse_vblk (data, len, vb)) {
+ kfree(vb);
+ return false; /* Already logged */
+ }
+
+ /* Put vblk into the correct list. */
+ switch (vb->type) {
+ case VBLK_DGR3:
+ case VBLK_DGR4:
+ list_add (&vb->list, &ldb->v_dgrp);
+ break;
+ case VBLK_DSK3:
+ case VBLK_DSK4:
+ list_add (&vb->list, &ldb->v_disk);
+ break;
+ case VBLK_VOL5:
+ list_add (&vb->list, &ldb->v_volu);
+ break;
+ case VBLK_CMP3:
+ list_add (&vb->list, &ldb->v_comp);
+ break;
+ case VBLK_PRT3:
+ /* Sort by the partition's start sector. */
+ list_for_each (item, &ldb->v_part) {
+ struct vblk *v = list_entry (item, struct vblk, list);
+ if ((v->vblk.part.disk_id == vb->vblk.part.disk_id) &&
+ (v->vblk.part.start > vb->vblk.part.start)) {
+ list_add_tail (&vb->list, &v->list);
+ return true;
+ }
+ }
+ list_add_tail (&vb->list, &ldb->v_part);
+ break;
+ }
+ return true;
+}
+
+/**
+ * ldm_frag_add - Add a VBLK fragment to a list
+ * @data: Raw fragment to be added to the list
+ * @size: Size of the raw fragment
+ * @frags: Linked list of VBLK fragments
+ *
+ * Fragmented VBLKs may not be consecutive in the database, so they are placed
+ * in a list so they can be pieced together later.
+ *
+ * Return: 'true' Success, the VBLK was added to the list
+ * 'false' Error, a problem occurred
+ */
+static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
+{
+ struct frag *f;
+ struct list_head *item;
+ int rec, num, group;
+
+ BUG_ON (!data || !frags);
+
+ if (size < 2 * VBLK_SIZE_HEAD) {
+ ldm_error("Value of size is to small.");
+ return false;
+ }
+
+ group = get_unaligned_be32(data + 0x08);
+ rec = get_unaligned_be16(data + 0x0C);
+ num = get_unaligned_be16(data + 0x0E);
+ if ((num < 1) || (num > 4)) {
+ ldm_error ("A VBLK claims to have %d parts.", num);
+ return false;
+ }
+ if (rec >= num) {
+ ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num);
+ return false;
+ }
+
+ list_for_each (item, frags) {
+ f = list_entry (item, struct frag, list);
+ if (f->group == group)
+ goto found;
+ }
+
+ f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
+ if (!f) {
+ ldm_crit ("Out of memory.");
+ return false;
+ }
+
+ f->group = group;
+ f->num = num;
+ f->rec = rec;
+ f->map = 0xFF << num;
+
+ list_add_tail (&f->list, frags);
+found:
+ if (rec >= f->num) {
+ ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
+ return false;
+ }
+ if (f->map & (1 << rec)) {
+ ldm_error ("Duplicate VBLK, part %d.", rec);
+ f->map &= 0x7F; /* Mark the group as broken */
+ return false;
+ }
+ f->map |= (1 << rec);
+ if (!rec)
+ memcpy(f->data, data, VBLK_SIZE_HEAD);
+ data += VBLK_SIZE_HEAD;
+ size -= VBLK_SIZE_HEAD;
+ memcpy(f->data + VBLK_SIZE_HEAD + rec * size, data, size);
+ return true;
+}
+
+/**
+ * ldm_frag_free - Free a linked list of VBLK fragments
+ * @list: Linked list of fragments
+ *
+ * Free a linked list of VBLK fragments
+ *
+ * Return: none
+ */
+static void ldm_frag_free (struct list_head *list)
+{
+ struct list_head *item, *tmp;
+
+ BUG_ON (!list);
+
+ list_for_each_safe (item, tmp, list)
+ kfree (list_entry (item, struct frag, list));
+}
+
+/**
+ * ldm_frag_commit - Validate fragmented VBLKs and add them to the database
+ * @frags: Linked list of VBLK fragments
+ * @ldb: Cache of the database structures
+ *
+ * Now that all the fragmented VBLKs have been collected, they must be added to
+ * the database for later use.
+ *
+ * Return: 'true' All the fragments we added successfully
+ * 'false' One or more of the fragments we invalid
+ */
+static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
+{
+ struct frag *f;
+ struct list_head *item;
+
+ BUG_ON (!frags || !ldb);
+
+ list_for_each (item, frags) {
+ f = list_entry (item, struct frag, list);
+
+ if (f->map != 0xFF) {
+ ldm_error ("VBLK group %d is incomplete (0x%02x).",
+ f->group, f->map);
+ return false;
+ }
+
+ if (!ldm_ldmdb_add (f->data, f->num*ldb->vm.vblk_size, ldb))
+ return false; /* Already logged */
+ }
+ return true;
+}
+
+/**
+ * ldm_get_vblks - Read the on-disk database of VBLKs into memory
+ * @state: Partition check state including device holding the LDM Database
+ * @base: Offset, into @state->bdev, of the database
+ * @ldb: Cache of the database structures
+ *
+ * To use the information from the VBLKs, they need to be read from the disk,
+ * unpacked and validated. We cache them in @ldb according to their type.
+ *
+ * Return: 'true' All the VBLKs were read successfully
+ * 'false' An error occurred
+ */
+static bool ldm_get_vblks(struct parsed_partitions *state, unsigned long base,
+ struct ldmdb *ldb)
+{
+ int size, perbuf, skip, finish, s, v, recs;
+ u8 *data = NULL;
+ Sector sect;
+ bool result = false;
+ LIST_HEAD (frags);
+
+ BUG_ON(!state || !ldb);
+
+ size = ldb->vm.vblk_size;
+ perbuf = 512 / size;
+ skip = ldb->vm.vblk_offset >> 9; /* Bytes to sectors */
+ finish = (size * ldb->vm.last_vblk_seq) >> 9;
+
+ for (s = skip; s < finish; s++) { /* For each sector */
+ data = read_part_sector(state, base + OFF_VMDB + s, §);
+ if (!data) {
+ ldm_crit ("Disk read failed.");
+ goto out;
+ }
+
+ for (v = 0; v < perbuf; v++, data+=size) { /* For each vblk */
+ if (MAGIC_VBLK != get_unaligned_be32(data)) {
+ ldm_error ("Expected to find a VBLK.");
+ goto out;
+ }
+
+ recs = get_unaligned_be16(data + 0x0E); /* Number of records */
+ if (recs == 1) {
+ if (!ldm_ldmdb_add (data, size, ldb))
+ goto out; /* Already logged */
+ } else if (recs > 1) {
+ if (!ldm_frag_add (data, size, &frags))
+ goto out; /* Already logged */
+ }
+ /* else Record is not in use, ignore it. */
+ }
+ put_dev_sector (sect);
+ data = NULL;
+ }
+
+ result = ldm_frag_commit (&frags, ldb); /* Failures, already logged */
+out:
+ if (data)
+ put_dev_sector (sect);
+ ldm_frag_free (&frags);
+
+ return result;
+}
+
+/**
+ * ldm_free_vblks - Free a linked list of vblk's
+ * @lh: Head of a linked list of struct vblk
+ *
+ * Free a list of vblk's and free the memory used to maintain the list.
+ *
+ * Return: none
+ */
+static void ldm_free_vblks (struct list_head *lh)
+{
+ struct list_head *item, *tmp;
+
+ BUG_ON (!lh);
+
+ list_for_each_safe (item, tmp, lh)
+ kfree (list_entry (item, struct vblk, list));
+}
+
+
+/**
+ * ldm_partition - Find out whether a device is a dynamic disk and handle it
+ * @state: Partition check state including device holding the LDM Database
+ *
+ * This determines whether the device @bdev is a dynamic disk and if so creates
+ * the partitions necessary in the gendisk structure pointed to by @hd.
+ *
+ * We create a dummy device 1, which contains the LDM database, and then create
+ * each partition described by the LDM database in sequence as devices 2+. For
+ * example, if the device is hda, we would have: hda1: LDM database, hda2, hda3,
+ * and so on: the actual data containing partitions.
+ *
+ * Return: 1 Success, @state->bdev is a dynamic disk and we handled it
+ * 0 Success, @state->bdev is not a dynamic disk
+ * -1 An error occurred before enough information had been read
+ * Or @state->bdev is a dynamic disk, but it may be corrupted
+ */
+int ldm_partition(struct parsed_partitions *state)
+{
+ struct ldmdb *ldb;
+ unsigned long base;
+ int result = -1;
+
+ BUG_ON(!state);
+
+ /* Look for signs of a Dynamic Disk */
+ if (!ldm_validate_partition_table(state))
+ return 0;
+
+ ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
+ if (!ldb) {
+ ldm_crit ("Out of memory.");
+ goto out;
+ }
+
+ /* Parse and check privheads. */
+ if (!ldm_validate_privheads(state, &ldb->ph))
+ goto out; /* Already logged */
+
+ /* All further references are relative to base (database start). */
+ base = ldb->ph.config_start;
+
+ /* Parse and check tocs and vmdb. */
+ if (!ldm_validate_tocblocks(state, base, ldb) ||
+ !ldm_validate_vmdb(state, base, ldb))
+ goto out; /* Already logged */
+
+ /* Initialize vblk lists in ldmdb struct */
+ INIT_LIST_HEAD (&ldb->v_dgrp);
+ INIT_LIST_HEAD (&ldb->v_disk);
+ INIT_LIST_HEAD (&ldb->v_volu);
+ INIT_LIST_HEAD (&ldb->v_comp);
+ INIT_LIST_HEAD (&ldb->v_part);
+
+ if (!ldm_get_vblks(state, base, ldb)) {
+ ldm_crit ("Failed to read the VBLKs from the database.");
+ goto cleanup;
+ }
+
+ /* Finally, create the data partition devices. */
+ if (ldm_create_data_partitions(state, ldb)) {
+ ldm_debug ("Parsed LDM database successfully.");
+ result = 1;
+ }
+ /* else Already logged */
+
+cleanup:
+ ldm_free_vblks (&ldb->v_dgrp);
+ ldm_free_vblks (&ldb->v_disk);
+ ldm_free_vblks (&ldb->v_volu);
+ ldm_free_vblks (&ldb->v_comp);
+ ldm_free_vblks (&ldb->v_part);
+out:
+ kfree (ldb);
+ return result;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/ldm.h b/src/kernel/linux/v4.14/block/partitions/ldm.h
new file mode 100644
index 0000000..f4c6055
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/ldm.h
@@ -0,0 +1,213 @@
+/**
+ * ldm - Part of the Linux-NTFS project.
+ *
+ * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
+ * Copyright (c) 2001-2007 Anton Altaparmakov
+ * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
+ *
+ * Documentation is available at http://www.linux-ntfs.org/doku.php?id=downloads
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program (in the main directory of the Linux-NTFS source
+ * in the file COPYING); if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _FS_PT_LDM_H_
+#define _FS_PT_LDM_H_
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/genhd.h>
+#include <linux/fs.h>
+#include <asm/unaligned.h>
+#include <asm/byteorder.h>
+
+struct parsed_partitions;
+
+/* Magic numbers in CPU format. */
+#define MAGIC_VMDB 0x564D4442 /* VMDB */
+#define MAGIC_VBLK 0x56424C4B /* VBLK */
+#define MAGIC_PRIVHEAD 0x5052495648454144ULL /* PRIVHEAD */
+#define MAGIC_TOCBLOCK 0x544F43424C4F434BULL /* TOCBLOCK */
+
+/* The defined vblk types. */
+#define VBLK_VOL5 0x51 /* Volume, version 5 */
+#define VBLK_CMP3 0x32 /* Component, version 3 */
+#define VBLK_PRT3 0x33 /* Partition, version 3 */
+#define VBLK_DSK3 0x34 /* Disk, version 3 */
+#define VBLK_DSK4 0x44 /* Disk, version 4 */
+#define VBLK_DGR3 0x35 /* Disk Group, version 3 */
+#define VBLK_DGR4 0x45 /* Disk Group, version 4 */
+
+/* vblk flags indicating extra information will be present */
+#define VBLK_FLAG_COMP_STRIPE 0x10
+#define VBLK_FLAG_PART_INDEX 0x08
+#define VBLK_FLAG_DGR3_IDS 0x08
+#define VBLK_FLAG_DGR4_IDS 0x08
+#define VBLK_FLAG_VOLU_ID1 0x08
+#define VBLK_FLAG_VOLU_ID2 0x20
+#define VBLK_FLAG_VOLU_SIZE 0x80
+#define VBLK_FLAG_VOLU_DRIVE 0x02
+
+/* size of a vblk's static parts */
+#define VBLK_SIZE_HEAD 16
+#define VBLK_SIZE_CMP3 22 /* Name and version */
+#define VBLK_SIZE_DGR3 12
+#define VBLK_SIZE_DGR4 44
+#define VBLK_SIZE_DSK3 12
+#define VBLK_SIZE_DSK4 45
+#define VBLK_SIZE_PRT3 28
+#define VBLK_SIZE_VOL5 58
+
+/* component types */
+#define COMP_STRIPE 0x01 /* Stripe-set */
+#define COMP_BASIC 0x02 /* Basic disk */
+#define COMP_RAID 0x03 /* Raid-set */
+
+/* Other constants. */
+#define LDM_DB_SIZE 2048 /* Size in sectors (= 1MiB). */
+
+#define OFF_PRIV1 6 /* Offset of the first privhead
+ relative to the start of the
+ device in sectors */
+
+/* Offsets to structures within the LDM Database in sectors. */
+#define OFF_PRIV2 1856 /* Backup private headers. */
+#define OFF_PRIV3 2047
+
+#define OFF_TOCB1 1 /* Tables of contents. */
+#define OFF_TOCB2 2
+#define OFF_TOCB3 2045
+#define OFF_TOCB4 2046
+
+#define OFF_VMDB 17 /* List of partitions. */
+
+#define LDM_PARTITION 0x42 /* Formerly SFS (Landis). */
+
+#define TOC_BITMAP1 "config" /* Names of the two defined */
+#define TOC_BITMAP2 "log" /* bitmaps in the TOCBLOCK. */
+
+/* Borrowed from msdos.c */
+#define SYS_IND(p) (get_unaligned(&(p)->sys_ind))
+
+struct frag { /* VBLK Fragment handling */
+ struct list_head list;
+ u32 group;
+ u8 num; /* Total number of records */
+ u8 rec; /* This is record number n */
+ u8 map; /* Which portions are in use */
+ u8 data[0];
+};
+
+/* In memory LDM database structures. */
+
+struct privhead { /* Offsets and sizes are in sectors. */
+ u16 ver_major;
+ u16 ver_minor;
+ u64 logical_disk_start;
+ u64 logical_disk_size;
+ u64 config_start;
+ u64 config_size;
+ uuid_t disk_id;
+};
+
+struct tocblock { /* We have exactly two bitmaps. */
+ u8 bitmap1_name[16];
+ u64 bitmap1_start;
+ u64 bitmap1_size;
+ u8 bitmap2_name[16];
+ u64 bitmap2_start;
+ u64 bitmap2_size;
+};
+
+struct vmdb { /* VMDB: The database header */
+ u16 ver_major;
+ u16 ver_minor;
+ u32 vblk_size;
+ u32 vblk_offset;
+ u32 last_vblk_seq;
+};
+
+struct vblk_comp { /* VBLK Component */
+ u8 state[16];
+ u64 parent_id;
+ u8 type;
+ u8 children;
+ u16 chunksize;
+};
+
+struct vblk_dgrp { /* VBLK Disk Group */
+ u8 disk_id[64];
+};
+
+struct vblk_disk { /* VBLK Disk */
+ uuid_t disk_id;
+ u8 alt_name[128];
+};
+
+struct vblk_part { /* VBLK Partition */
+ u64 start;
+ u64 size; /* start, size and vol_off in sectors */
+ u64 volume_offset;
+ u64 parent_id;
+ u64 disk_id;
+ u8 partnum;
+};
+
+struct vblk_volu { /* VBLK Volume */
+ u8 volume_type[16];
+ u8 volume_state[16];
+ u8 guid[16];
+ u8 drive_hint[4];
+ u64 size;
+ u8 partition_type;
+};
+
+struct vblk_head { /* VBLK standard header */
+ u32 group;
+ u16 rec;
+ u16 nrec;
+};
+
+struct vblk { /* Generalised VBLK */
+ u8 name[64];
+ u64 obj_id;
+ u32 sequence;
+ u8 flags;
+ u8 type;
+ union {
+ struct vblk_comp comp;
+ struct vblk_dgrp dgrp;
+ struct vblk_disk disk;
+ struct vblk_part part;
+ struct vblk_volu volu;
+ } vblk;
+ struct list_head list;
+};
+
+struct ldmdb { /* Cache of the database */
+ struct privhead ph;
+ struct tocblock toc;
+ struct vmdb vm;
+ struct list_head v_dgrp;
+ struct list_head v_disk;
+ struct list_head v_volu;
+ struct list_head v_comp;
+ struct list_head v_part;
+};
+
+int ldm_partition(struct parsed_partitions *state);
+
+#endif /* _FS_PT_LDM_H_ */
+
diff --git a/src/kernel/linux/v4.14/block/partitions/mac.c b/src/kernel/linux/v4.14/block/partitions/mac.c
new file mode 100644
index 0000000..b609533
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/mac.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/mac.c
+ *
+ * Code extracted from drivers/block/genhd.c
+ * Copyright (C) 1991-1998 Linus Torvalds
+ * Re-organised Feb 1998 Russell King
+ */
+
+#include <linux/ctype.h>
+#include "check.h"
+#include "mac.h"
+
+#ifdef CONFIG_PPC_PMAC
+#include <asm/machdep.h>
+extern void note_bootable_part(dev_t dev, int part, int goodness);
+#endif
+
+/*
+ * Code to understand MacOS partition tables.
+ */
+
+static inline void mac_fix_string(char *stg, int len)
+{
+ int i;
+
+ for (i = len - 1; i >= 0 && stg[i] == ' '; i--)
+ stg[i] = 0;
+}
+
+int mac_partition(struct parsed_partitions *state)
+{
+ Sector sect;
+ unsigned char *data;
+ int slot, blocks_in_map;
+ unsigned secsize, datasize, partoffset;
+#ifdef CONFIG_PPC_PMAC
+ int found_root = 0;
+ int found_root_goodness = 0;
+#endif
+ struct mac_partition *part;
+ struct mac_driver_desc *md;
+
+ /* Get 0th block and look at the first partition map entry. */
+ md = read_part_sector(state, 0, §);
+ if (!md)
+ return -1;
+ if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC) {
+ put_dev_sector(sect);
+ return 0;
+ }
+ secsize = be16_to_cpu(md->block_size);
+ put_dev_sector(sect);
+ datasize = round_down(secsize, 512);
+ data = read_part_sector(state, datasize / 512, §);
+ if (!data)
+ return -1;
+ partoffset = secsize % 512;
+ if (partoffset + sizeof(*part) > datasize)
+ return -1;
+ part = (struct mac_partition *) (data + partoffset);
+ if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
+ put_dev_sector(sect);
+ return 0; /* not a MacOS disk */
+ }
+ blocks_in_map = be32_to_cpu(part->map_count);
+ if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
+ put_dev_sector(sect);
+ return 0;
+ }
+
+ if (blocks_in_map >= state->limit)
+ blocks_in_map = state->limit - 1;
+
+ strlcat(state->pp_buf, " [mac]", PAGE_SIZE);
+ for (slot = 1; slot <= blocks_in_map; ++slot) {
+ int pos = slot * secsize;
+ put_dev_sector(sect);
+ data = read_part_sector(state, pos/512, §);
+ if (!data)
+ return -1;
+ part = (struct mac_partition *) (data + pos%512);
+ if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
+ break;
+ put_partition(state, slot,
+ be32_to_cpu(part->start_block) * (secsize/512),
+ be32_to_cpu(part->block_count) * (secsize/512));
+
+ if (!strncasecmp(part->type, "Linux_RAID", 10))
+ state->parts[slot].flags = ADDPART_FLAG_RAID;
+#ifdef CONFIG_PPC_PMAC
+ /*
+ * If this is the first bootable partition, tell the
+ * setup code, in case it wants to make this the root.
+ */
+ if (machine_is(powermac)) {
+ int goodness = 0;
+
+ mac_fix_string(part->processor, 16);
+ mac_fix_string(part->name, 32);
+ mac_fix_string(part->type, 32);
+
+ if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
+ && strcasecmp(part->processor, "powerpc") == 0)
+ goodness++;
+
+ if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
+ || (strncasecmp(part->type, "Linux", 5) == 0
+ && strcasecmp(part->type, "Linux_swap") != 0)) {
+ int i, l;
+
+ goodness++;
+ l = strlen(part->name);
+ if (strcmp(part->name, "/") == 0)
+ goodness++;
+ for (i = 0; i <= l - 4; ++i) {
+ if (strncasecmp(part->name + i, "root",
+ 4) == 0) {
+ goodness += 2;
+ break;
+ }
+ }
+ if (strncasecmp(part->name, "swap", 4) == 0)
+ goodness--;
+ }
+
+ if (goodness > found_root_goodness) {
+ found_root = slot;
+ found_root_goodness = goodness;
+ }
+ }
+#endif /* CONFIG_PPC_PMAC */
+ }
+#ifdef CONFIG_PPC_PMAC
+ if (found_root_goodness)
+ note_bootable_part(state->bdev->bd_dev, found_root,
+ found_root_goodness);
+#endif
+
+ put_dev_sector(sect);
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ return 1;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/mac.h b/src/kernel/linux/v4.14/block/partitions/mac.h
new file mode 100644
index 0000000..453ed29
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/mac.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * fs/partitions/mac.h
+ */
+
+#define MAC_PARTITION_MAGIC 0x504d
+
+/* type field value for A/UX or other Unix partitions */
+#define APPLE_AUX_TYPE "Apple_UNIX_SVR2"
+
+struct mac_partition {
+ __be16 signature; /* expected to be MAC_PARTITION_MAGIC */
+ __be16 res1;
+ __be32 map_count; /* # blocks in partition map */
+ __be32 start_block; /* absolute starting block # of partition */
+ __be32 block_count; /* number of blocks in partition */
+ char name[32]; /* partition name */
+ char type[32]; /* string type description */
+ __be32 data_start; /* rel block # of first data block */
+ __be32 data_count; /* number of data blocks */
+ __be32 status; /* partition status bits */
+ __be32 boot_start;
+ __be32 boot_size;
+ __be32 boot_load;
+ __be32 boot_load2;
+ __be32 boot_entry;
+ __be32 boot_entry2;
+ __be32 boot_cksum;
+ char processor[16]; /* identifies ISA of boot */
+ /* there is more stuff after this that we don't need */
+};
+
+#define MAC_STATUS_BOOTABLE 8 /* partition is bootable */
+
+#define MAC_DRIVER_MAGIC 0x4552
+
+/* Driver descriptor structure, in block 0 */
+struct mac_driver_desc {
+ __be16 signature; /* expected to be MAC_DRIVER_MAGIC */
+ __be16 block_size;
+ __be32 block_count;
+ /* ... more stuff */
+};
+
+int mac_partition(struct parsed_partitions *state);
diff --git a/src/kernel/linux/v4.14/block/partitions/msdos.c b/src/kernel/linux/v4.14/block/partitions/msdos.c
new file mode 100644
index 0000000..82c44f7
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/msdos.c
@@ -0,0 +1,587 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/msdos.c
+ *
+ * Code extracted from drivers/block/genhd.c
+ * Copyright (C) 1991-1998 Linus Torvalds
+ *
+ * Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
+ * in the early extended-partition checks and added DM partitions
+ *
+ * Support for DiskManager v6.0x added by Mark Lord,
+ * with information provided by OnTrack. This now works for linux fdisk
+ * and LILO, as well as loadlin and bootln. Note that disks other than
+ * /dev/hda *must* have a "DOS" type 0x51 partition in the first slot (hda1).
+ *
+ * More flexible handling of extended partitions - aeb, 950831
+ *
+ * Check partition table on IDE disks for common CHS translations
+ *
+ * Re-organised Feb 1998 Russell King
+ */
+#include <linux/msdos_fs.h>
+
+#include "check.h"
+#include "msdos.h"
+#include "efi.h"
+#include "aix.h"
+
+/*
+ * Many architectures don't like unaligned accesses, while
+ * the nr_sects and start_sect partition table entries are
+ * at a 2 (mod 4) address.
+ */
+#include <asm/unaligned.h>
+
+#define SYS_IND(p) get_unaligned(&p->sys_ind)
+
+static inline sector_t nr_sects(struct partition *p)
+{
+ return (sector_t)get_unaligned_le32(&p->nr_sects);
+}
+
+static inline sector_t start_sect(struct partition *p)
+{
+ return (sector_t)get_unaligned_le32(&p->start_sect);
+}
+
+static inline int is_extended_partition(struct partition *p)
+{
+ return (SYS_IND(p) == DOS_EXTENDED_PARTITION ||
+ SYS_IND(p) == WIN98_EXTENDED_PARTITION ||
+ SYS_IND(p) == LINUX_EXTENDED_PARTITION);
+}
+
+#define MSDOS_LABEL_MAGIC1 0x55
+#define MSDOS_LABEL_MAGIC2 0xAA
+
+static inline int
+msdos_magic_present(unsigned char *p)
+{
+ return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2);
+}
+
+/* Value is EBCDIC 'IBMA' */
+#define AIX_LABEL_MAGIC1 0xC9
+#define AIX_LABEL_MAGIC2 0xC2
+#define AIX_LABEL_MAGIC3 0xD4
+#define AIX_LABEL_MAGIC4 0xC1
+static int aix_magic_present(struct parsed_partitions *state, unsigned char *p)
+{
+ struct partition *pt = (struct partition *) (p + 0x1be);
+ Sector sect;
+ unsigned char *d;
+ int slot, ret = 0;
+
+ if (!(p[0] == AIX_LABEL_MAGIC1 &&
+ p[1] == AIX_LABEL_MAGIC2 &&
+ p[2] == AIX_LABEL_MAGIC3 &&
+ p[3] == AIX_LABEL_MAGIC4))
+ return 0;
+ /* Assume the partition table is valid if Linux partitions exists */
+ for (slot = 1; slot <= 4; slot++, pt++) {
+ if (pt->sys_ind == LINUX_SWAP_PARTITION ||
+ pt->sys_ind == LINUX_RAID_PARTITION ||
+ pt->sys_ind == LINUX_DATA_PARTITION ||
+ pt->sys_ind == LINUX_LVM_PARTITION ||
+ is_extended_partition(pt))
+ return 0;
+ }
+ d = read_part_sector(state, 7, §);
+ if (d) {
+ if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M')
+ ret = 1;
+ put_dev_sector(sect);
+ }
+ return ret;
+}
+
+static void set_info(struct parsed_partitions *state, int slot,
+ u32 disksig)
+{
+ struct partition_meta_info *info = &state->parts[slot].info;
+
+ snprintf(info->uuid, sizeof(info->uuid), "%08x-%02x", disksig,
+ slot);
+ info->volname[0] = 0;
+ state->parts[slot].has_info = true;
+}
+
+/*
+ * Create devices for each logical partition in an extended partition.
+ * The logical partitions form a linked list, with each entry being
+ * a partition table with two entries. The first entry
+ * is the real data partition (with a start relative to the partition
+ * table start). The second is a pointer to the next logical partition
+ * (with a start relative to the entire extended partition).
+ * We do not create a Linux partition for the partition tables, but
+ * only for the actual data partitions.
+ */
+
+static void parse_extended(struct parsed_partitions *state,
+ sector_t first_sector, sector_t first_size,
+ u32 disksig)
+{
+ struct partition *p;
+ Sector sect;
+ unsigned char *data;
+ sector_t this_sector, this_size;
+ sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
+ int loopct = 0; /* number of links followed
+ without finding a data partition */
+ int i;
+
+ this_sector = first_sector;
+ this_size = first_size;
+
+ while (1) {
+ if (++loopct > 100)
+ return;
+ if (state->next == state->limit)
+ return;
+ data = read_part_sector(state, this_sector, §);
+ if (!data)
+ return;
+
+ if (!msdos_magic_present(data + 510))
+ goto done;
+
+ p = (struct partition *) (data + 0x1be);
+
+ /*
+ * Usually, the first entry is the real data partition,
+ * the 2nd entry is the next extended partition, or empty,
+ * and the 3rd and 4th entries are unused.
+ * However, DRDOS sometimes has the extended partition as
+ * the first entry (when the data partition is empty),
+ * and OS/2 seems to use all four entries.
+ */
+
+ /*
+ * First process the data partition(s)
+ */
+ for (i = 0; i < 4; i++, p++) {
+ sector_t offs, size, next;
+
+ if (!nr_sects(p) || is_extended_partition(p))
+ continue;
+
+ /* Check the 3rd and 4th entries -
+ these sometimes contain random garbage */
+ offs = start_sect(p)*sector_size;
+ size = nr_sects(p)*sector_size;
+ next = this_sector + offs;
+ if (i >= 2) {
+ if (offs + size > this_size)
+ continue;
+ if (next < first_sector)
+ continue;
+ if (next + size > first_sector + first_size)
+ continue;
+ }
+
+ put_partition(state, state->next, next, size);
+ set_info(state, state->next, disksig);
+ if (SYS_IND(p) == LINUX_RAID_PARTITION)
+ state->parts[state->next].flags = ADDPART_FLAG_RAID;
+ loopct = 0;
+ if (++state->next == state->limit)
+ goto done;
+ }
+ /*
+ * Next, process the (first) extended partition, if present.
+ * (So far, there seems to be no reason to make
+ * parse_extended() recursive and allow a tree
+ * of extended partitions.)
+ * It should be a link to the next logical partition.
+ */
+ p -= 4;
+ for (i = 0; i < 4; i++, p++)
+ if (nr_sects(p) && is_extended_partition(p))
+ break;
+ if (i == 4)
+ goto done; /* nothing left to do */
+
+ this_sector = first_sector + start_sect(p) * sector_size;
+ this_size = nr_sects(p) * sector_size;
+ put_dev_sector(sect);
+ }
+done:
+ put_dev_sector(sect);
+}
+
+/* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also
+ indicates linux swap. Be careful before believing this is Solaris. */
+
+static void parse_solaris_x86(struct parsed_partitions *state,
+ sector_t offset, sector_t size, int origin)
+{
+#ifdef CONFIG_SOLARIS_X86_PARTITION
+ Sector sect;
+ struct solaris_x86_vtoc *v;
+ int i;
+ short max_nparts;
+
+ v = read_part_sector(state, offset + 1, §);
+ if (!v)
+ return;
+ if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) {
+ put_dev_sector(sect);
+ return;
+ }
+ {
+ char tmp[1 + BDEVNAME_SIZE + 10 + 11 + 1];
+
+ snprintf(tmp, sizeof(tmp), " %s%d: <solaris:", state->name, origin);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ }
+ if (le32_to_cpu(v->v_version) != 1) {
+ char tmp[64];
+
+ snprintf(tmp, sizeof(tmp), " cannot handle version %d vtoc>\n",
+ le32_to_cpu(v->v_version));
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ put_dev_sector(sect);
+ return;
+ }
+ /* Ensure we can handle previous case of VTOC with 8 entries gracefully */
+ max_nparts = le16_to_cpu(v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8;
+ for (i = 0; i < max_nparts && state->next < state->limit; i++) {
+ struct solaris_x86_slice *s = &v->v_slice[i];
+ char tmp[3 + 10 + 1 + 1];
+
+ if (s->s_size == 0)
+ continue;
+ snprintf(tmp, sizeof(tmp), " [s%d]", i);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ /* solaris partitions are relative to current MS-DOS
+ * one; must add the offset of the current partition */
+ put_partition(state, state->next++,
+ le32_to_cpu(s->s_start)+offset,
+ le32_to_cpu(s->s_size));
+ }
+ put_dev_sector(sect);
+ strlcat(state->pp_buf, " >\n", PAGE_SIZE);
+#endif
+}
+
+#if defined(CONFIG_BSD_DISKLABEL)
+/*
+ * Create devices for BSD partitions listed in a disklabel, under a
+ * dos-like partition. See parse_extended() for more information.
+ */
+static void parse_bsd(struct parsed_partitions *state,
+ sector_t offset, sector_t size, int origin, char *flavour,
+ int max_partitions)
+{
+ Sector sect;
+ struct bsd_disklabel *l;
+ struct bsd_partition *p;
+ char tmp[64];
+
+ l = read_part_sector(state, offset + 1, §);
+ if (!l)
+ return;
+ if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
+ put_dev_sector(sect);
+ return;
+ }
+
+ snprintf(tmp, sizeof(tmp), " %s%d: <%s:", state->name, origin, flavour);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+
+ if (le16_to_cpu(l->d_npartitions) < max_partitions)
+ max_partitions = le16_to_cpu(l->d_npartitions);
+ for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) {
+ sector_t bsd_start, bsd_size;
+
+ if (state->next == state->limit)
+ break;
+ if (p->p_fstype == BSD_FS_UNUSED)
+ continue;
+ bsd_start = le32_to_cpu(p->p_offset);
+ bsd_size = le32_to_cpu(p->p_size);
+ /* FreeBSD has relative offset if C partition offset is zero */
+ if (memcmp(flavour, "bsd\0", 4) == 0 &&
+ le32_to_cpu(l->d_partitions[2].p_offset) == 0)
+ bsd_start += offset;
+ if (offset == bsd_start && size == bsd_size)
+ /* full parent partition, we have it already */
+ continue;
+ if (offset > bsd_start || offset+size < bsd_start+bsd_size) {
+ strlcat(state->pp_buf, "bad subpartition - ignored\n", PAGE_SIZE);
+ continue;
+ }
+ put_partition(state, state->next++, bsd_start, bsd_size);
+ }
+ put_dev_sector(sect);
+ if (le16_to_cpu(l->d_npartitions) > max_partitions) {
+ snprintf(tmp, sizeof(tmp), " (ignored %d more)",
+ le16_to_cpu(l->d_npartitions) - max_partitions);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ }
+ strlcat(state->pp_buf, " >\n", PAGE_SIZE);
+}
+#endif
+
+static void parse_freebsd(struct parsed_partitions *state,
+ sector_t offset, sector_t size, int origin)
+{
+#ifdef CONFIG_BSD_DISKLABEL
+ parse_bsd(state, offset, size, origin, "bsd", BSD_MAXPARTITIONS);
+#endif
+}
+
+static void parse_netbsd(struct parsed_partitions *state,
+ sector_t offset, sector_t size, int origin)
+{
+#ifdef CONFIG_BSD_DISKLABEL
+ parse_bsd(state, offset, size, origin, "netbsd", BSD_MAXPARTITIONS);
+#endif
+}
+
+static void parse_openbsd(struct parsed_partitions *state,
+ sector_t offset, sector_t size, int origin)
+{
+#ifdef CONFIG_BSD_DISKLABEL
+ parse_bsd(state, offset, size, origin, "openbsd",
+ OPENBSD_MAXPARTITIONS);
+#endif
+}
+
+/*
+ * Create devices for Unixware partitions listed in a disklabel, under a
+ * dos-like partition. See parse_extended() for more information.
+ */
+static void parse_unixware(struct parsed_partitions *state,
+ sector_t offset, sector_t size, int origin)
+{
+#ifdef CONFIG_UNIXWARE_DISKLABEL
+ Sector sect;
+ struct unixware_disklabel *l;
+ struct unixware_slice *p;
+
+ l = read_part_sector(state, offset + 29, §);
+ if (!l)
+ return;
+ if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC ||
+ le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) {
+ put_dev_sector(sect);
+ return;
+ }
+ {
+ char tmp[1 + BDEVNAME_SIZE + 10 + 12 + 1];
+
+ snprintf(tmp, sizeof(tmp), " %s%d: <unixware:", state->name, origin);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ }
+ p = &l->vtoc.v_slice[1];
+ /* I omit the 0th slice as it is the same as whole disk. */
+ while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) {
+ if (state->next == state->limit)
+ break;
+
+ if (p->s_label != UNIXWARE_FS_UNUSED)
+ put_partition(state, state->next++,
+ le32_to_cpu(p->start_sect),
+ le32_to_cpu(p->nr_sects));
+ p++;
+ }
+ put_dev_sector(sect);
+ strlcat(state->pp_buf, " >\n", PAGE_SIZE);
+#endif
+}
+
+/*
+ * Minix 2.0.0/2.0.2 subpartition support.
+ * Anand Krishnamurthy <anandk@wiproge.med.ge.com>
+ * Rajeev V. Pillai <rajeevvp@yahoo.com>
+ */
+static void parse_minix(struct parsed_partitions *state,
+ sector_t offset, sector_t size, int origin)
+{
+#ifdef CONFIG_MINIX_SUBPARTITION
+ Sector sect;
+ unsigned char *data;
+ struct partition *p;
+ int i;
+
+ data = read_part_sector(state, offset, §);
+ if (!data)
+ return;
+
+ p = (struct partition *)(data + 0x1be);
+
+ /* The first sector of a Minix partition can have either
+ * a secondary MBR describing its subpartitions, or
+ * the normal boot sector. */
+ if (msdos_magic_present(data + 510) &&
+ SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */
+ char tmp[1 + BDEVNAME_SIZE + 10 + 9 + 1];
+
+ snprintf(tmp, sizeof(tmp), " %s%d: <minix:", state->name, origin);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) {
+ if (state->next == state->limit)
+ break;
+ /* add each partition in use */
+ if (SYS_IND(p) == MINIX_PARTITION)
+ put_partition(state, state->next++,
+ start_sect(p), nr_sects(p));
+ }
+ strlcat(state->pp_buf, " >\n", PAGE_SIZE);
+ }
+ put_dev_sector(sect);
+#endif /* CONFIG_MINIX_SUBPARTITION */
+}
+
+static struct {
+ unsigned char id;
+ void (*parse)(struct parsed_partitions *, sector_t, sector_t, int);
+} subtypes[] = {
+ {FREEBSD_PARTITION, parse_freebsd},
+ {NETBSD_PARTITION, parse_netbsd},
+ {OPENBSD_PARTITION, parse_openbsd},
+ {MINIX_PARTITION, parse_minix},
+ {UNIXWARE_PARTITION, parse_unixware},
+ {SOLARIS_X86_PARTITION, parse_solaris_x86},
+ {NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
+ {0, NULL},
+};
+
+int msdos_partition(struct parsed_partitions *state)
+{
+ sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
+ Sector sect;
+ unsigned char *data;
+ struct partition *p;
+ struct fat_boot_sector *fb;
+ int slot;
+ u32 disksig;
+
+ data = read_part_sector(state, 0, §);
+ if (!data)
+ return -1;
+
+ /*
+ * Note order! (some AIX disks, e.g. unbootable kind,
+ * have no MSDOS 55aa)
+ */
+ if (aix_magic_present(state, data)) {
+ put_dev_sector(sect);
+#ifdef CONFIG_AIX_PARTITION
+ return aix_partition(state);
+#else
+ strlcat(state->pp_buf, " [AIX]", PAGE_SIZE);
+ return 0;
+#endif
+ }
+
+ if (!msdos_magic_present(data + 510)) {
+ put_dev_sector(sect);
+ return 0;
+ }
+
+ /*
+ * Now that the 55aa signature is present, this is probably
+ * either the boot sector of a FAT filesystem or a DOS-type
+ * partition table. Reject this in case the boot indicator
+ * is not 0 or 0x80.
+ */
+ p = (struct partition *) (data + 0x1be);
+ for (slot = 1; slot <= 4; slot++, p++) {
+ if (p->boot_ind != 0 && p->boot_ind != 0x80) {
+ /*
+ * Even without a valid boot inidicator value
+ * its still possible this is valid FAT filesystem
+ * without a partition table.
+ */
+ fb = (struct fat_boot_sector *) data;
+ if (slot == 1 && fb->reserved && fb->fats
+ && fat_valid_media(fb->media)) {
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ put_dev_sector(sect);
+ return 1;
+ } else {
+ put_dev_sector(sect);
+ return 0;
+ }
+ }
+ }
+
+#ifdef CONFIG_EFI_PARTITION
+ p = (struct partition *) (data + 0x1be);
+ for (slot = 1 ; slot <= 4 ; slot++, p++) {
+ /* If this is an EFI GPT disk, msdos should ignore it. */
+ if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) {
+ put_dev_sector(sect);
+ return 0;
+ }
+ }
+#endif
+ p = (struct partition *) (data + 0x1be);
+
+ disksig = le32_to_cpup((__le32 *)(data + 0x1b8));
+
+ /*
+ * Look for partitions in two passes:
+ * First find the primary and DOS-type extended partitions.
+ * On the second pass look inside *BSD, Unixware and Solaris partitions.
+ */
+
+ state->next = 5;
+ for (slot = 1 ; slot <= 4 ; slot++, p++) {
+ sector_t start = start_sect(p)*sector_size;
+ sector_t size = nr_sects(p)*sector_size;
+
+ if (!size)
+ continue;
+ if (is_extended_partition(p)) {
+ /*
+ * prevent someone doing mkfs or mkswap on an
+ * extended partition, but leave room for LILO
+ * FIXME: this uses one logical sector for > 512b
+ * sector, although it may not be enough/proper.
+ */
+ sector_t n = 2;
+
+ n = min(size, max(sector_size, n));
+ put_partition(state, slot, start, n);
+
+ strlcat(state->pp_buf, " <", PAGE_SIZE);
+ parse_extended(state, start, size, disksig);
+ strlcat(state->pp_buf, " >", PAGE_SIZE);
+ continue;
+ }
+ put_partition(state, slot, start, size);
+ set_info(state, slot, disksig);
+ if (SYS_IND(p) == LINUX_RAID_PARTITION)
+ state->parts[slot].flags = ADDPART_FLAG_RAID;
+ if (SYS_IND(p) == DM6_PARTITION)
+ strlcat(state->pp_buf, "[DM]", PAGE_SIZE);
+ if (SYS_IND(p) == EZD_PARTITION)
+ strlcat(state->pp_buf, "[EZD]", PAGE_SIZE);
+ }
+
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+
+ /* second pass - output for each on a separate line */
+ p = (struct partition *) (0x1be + data);
+ for (slot = 1 ; slot <= 4 ; slot++, p++) {
+ unsigned char id = SYS_IND(p);
+ int n;
+
+ if (!nr_sects(p))
+ continue;
+
+ for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++)
+ ;
+
+ if (!subtypes[n].parse)
+ continue;
+ subtypes[n].parse(state, start_sect(p) * sector_size,
+ nr_sects(p) * sector_size, slot);
+ }
+ put_dev_sector(sect);
+ return 1;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/msdos.h b/src/kernel/linux/v4.14/block/partitions/msdos.h
new file mode 100644
index 0000000..38c781c
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/msdos.h
@@ -0,0 +1,8 @@
+/*
+ * fs/partitions/msdos.h
+ */
+
+#define MSDOS_LABEL_MAGIC 0xAA55
+
+int msdos_partition(struct parsed_partitions *state);
+
diff --git a/src/kernel/linux/v4.14/block/partitions/osf.c b/src/kernel/linux/v4.14/block/partitions/osf.c
new file mode 100644
index 0000000..4b87397
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/osf.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/osf.c
+ *
+ * Code extracted from drivers/block/genhd.c
+ *
+ * Copyright (C) 1991-1998 Linus Torvalds
+ * Re-organised Feb 1998 Russell King
+ */
+
+#include "check.h"
+#include "osf.h"
+
+#define MAX_OSF_PARTITIONS 18
+
+int osf_partition(struct parsed_partitions *state)
+{
+ int i;
+ int slot = 1;
+ unsigned int npartitions;
+ Sector sect;
+ unsigned char *data;
+ struct disklabel {
+ __le32 d_magic;
+ __le16 d_type,d_subtype;
+ u8 d_typename[16];
+ u8 d_packname[16];
+ __le32 d_secsize;
+ __le32 d_nsectors;
+ __le32 d_ntracks;
+ __le32 d_ncylinders;
+ __le32 d_secpercyl;
+ __le32 d_secprtunit;
+ __le16 d_sparespertrack;
+ __le16 d_sparespercyl;
+ __le32 d_acylinders;
+ __le16 d_rpm, d_interleave, d_trackskew, d_cylskew;
+ __le32 d_headswitch, d_trkseek, d_flags;
+ __le32 d_drivedata[5];
+ __le32 d_spare[5];
+ __le32 d_magic2;
+ __le16 d_checksum;
+ __le16 d_npartitions;
+ __le32 d_bbsize, d_sbsize;
+ struct d_partition {
+ __le32 p_size;
+ __le32 p_offset;
+ __le32 p_fsize;
+ u8 p_fstype;
+ u8 p_frag;
+ __le16 p_cpg;
+ } d_partitions[MAX_OSF_PARTITIONS];
+ } * label;
+ struct d_partition * partition;
+
+ data = read_part_sector(state, 0, §);
+ if (!data)
+ return -1;
+
+ label = (struct disklabel *) (data+64);
+ partition = label->d_partitions;
+ if (le32_to_cpu(label->d_magic) != DISKLABELMAGIC) {
+ put_dev_sector(sect);
+ return 0;
+ }
+ if (le32_to_cpu(label->d_magic2) != DISKLABELMAGIC) {
+ put_dev_sector(sect);
+ return 0;
+ }
+ npartitions = le16_to_cpu(label->d_npartitions);
+ if (npartitions > MAX_OSF_PARTITIONS) {
+ put_dev_sector(sect);
+ return 0;
+ }
+ for (i = 0 ; i < npartitions; i++, partition++) {
+ if (slot == state->limit)
+ break;
+ if (le32_to_cpu(partition->p_size))
+ put_partition(state, slot,
+ le32_to_cpu(partition->p_offset),
+ le32_to_cpu(partition->p_size));
+ slot++;
+ }
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ put_dev_sector(sect);
+ return 1;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/osf.h b/src/kernel/linux/v4.14/block/partitions/osf.h
new file mode 100644
index 0000000..20ed231
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/osf.h
@@ -0,0 +1,7 @@
+/*
+ * fs/partitions/osf.h
+ */
+
+#define DISKLABELMAGIC (0x82564557UL)
+
+int osf_partition(struct parsed_partitions *state);
diff --git a/src/kernel/linux/v4.14/block/partitions/sgi.c b/src/kernel/linux/v4.14/block/partitions/sgi.c
new file mode 100644
index 0000000..d7b421c
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/sgi.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/sgi.c
+ *
+ * Code extracted from drivers/block/genhd.c
+ */
+
+#include "check.h"
+#include "sgi.h"
+
+struct sgi_disklabel {
+ __be32 magic_mushroom; /* Big fat spliff... */
+ __be16 root_part_num; /* Root partition number */
+ __be16 swap_part_num; /* Swap partition number */
+ s8 boot_file[16]; /* Name of boot file for ARCS */
+ u8 _unused0[48]; /* Device parameter useless crapola.. */
+ struct sgi_volume {
+ s8 name[8]; /* Name of volume */
+ __be32 block_num; /* Logical block number */
+ __be32 num_bytes; /* How big, in bytes */
+ } volume[15];
+ struct sgi_partition {
+ __be32 num_blocks; /* Size in logical blocks */
+ __be32 first_block; /* First logical block */
+ __be32 type; /* Type of this partition */
+ } partitions[16];
+ __be32 csum; /* Disk label checksum */
+ __be32 _unused1; /* Padding */
+};
+
+int sgi_partition(struct parsed_partitions *state)
+{
+ int i, csum;
+ __be32 magic;
+ int slot = 1;
+ unsigned int start, blocks;
+ __be32 *ui, cs;
+ Sector sect;
+ struct sgi_disklabel *label;
+ struct sgi_partition *p;
+ char b[BDEVNAME_SIZE];
+
+ label = read_part_sector(state, 0, §);
+ if (!label)
+ return -1;
+ p = &label->partitions[0];
+ magic = label->magic_mushroom;
+ if(be32_to_cpu(magic) != SGI_LABEL_MAGIC) {
+ /*printk("Dev %s SGI disklabel: bad magic %08x\n",
+ bdevname(bdev, b), be32_to_cpu(magic));*/
+ put_dev_sector(sect);
+ return 0;
+ }
+ ui = ((__be32 *) (label + 1)) - 1;
+ for(csum = 0; ui >= ((__be32 *) label);) {
+ cs = *ui--;
+ csum += be32_to_cpu(cs);
+ }
+ if(csum) {
+ printk(KERN_WARNING "Dev %s SGI disklabel: csum bad, label corrupted\n",
+ bdevname(state->bdev, b));
+ put_dev_sector(sect);
+ return 0;
+ }
+ /* All SGI disk labels have 16 partitions, disks under Linux only
+ * have 15 minor's. Luckily there are always a few zero length
+ * partitions which we don't care about so we never overflow the
+ * current_minor.
+ */
+ for(i = 0; i < 16; i++, p++) {
+ blocks = be32_to_cpu(p->num_blocks);
+ start = be32_to_cpu(p->first_block);
+ if (blocks) {
+ put_partition(state, slot, start, blocks);
+ if (be32_to_cpu(p->type) == LINUX_RAID_PARTITION)
+ state->parts[slot].flags = ADDPART_FLAG_RAID;
+ }
+ slot++;
+ }
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ put_dev_sector(sect);
+ return 1;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/sgi.h b/src/kernel/linux/v4.14/block/partitions/sgi.h
new file mode 100644
index 0000000..b9553eb
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/sgi.h
@@ -0,0 +1,8 @@
+/*
+ * fs/partitions/sgi.h
+ */
+
+extern int sgi_partition(struct parsed_partitions *state);
+
+#define SGI_LABEL_MAGIC 0x0be5a941
+
diff --git a/src/kernel/linux/v4.14/block/partitions/sun.c b/src/kernel/linux/v4.14/block/partitions/sun.c
new file mode 100644
index 0000000..90f3672
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/sun.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/sun.c
+ *
+ * Code extracted from drivers/block/genhd.c
+ *
+ * Copyright (C) 1991-1998 Linus Torvalds
+ * Re-organised Feb 1998 Russell King
+ */
+
+#include "check.h"
+#include "sun.h"
+
+int sun_partition(struct parsed_partitions *state)
+{
+ int i;
+ __be16 csum;
+ int slot = 1;
+ __be16 *ush;
+ Sector sect;
+ struct sun_disklabel {
+ unsigned char info[128]; /* Informative text string */
+ struct sun_vtoc {
+ __be32 version; /* Layout version */
+ char volume[8]; /* Volume name */
+ __be16 nparts; /* Number of partitions */
+ struct sun_info { /* Partition hdrs, sec 2 */
+ __be16 id;
+ __be16 flags;
+ } infos[8];
+ __be16 padding; /* Alignment padding */
+ __be32 bootinfo[3]; /* Info needed by mboot */
+ __be32 sanity; /* To verify vtoc sanity */
+ __be32 reserved[10]; /* Free space */
+ __be32 timestamp[8]; /* Partition timestamp */
+ } vtoc;
+ __be32 write_reinstruct; /* sectors to skip, writes */
+ __be32 read_reinstruct; /* sectors to skip, reads */
+ unsigned char spare[148]; /* Padding */
+ __be16 rspeed; /* Disk rotational speed */
+ __be16 pcylcount; /* Physical cylinder count */
+ __be16 sparecyl; /* extra sects per cylinder */
+ __be16 obs1; /* gap1 */
+ __be16 obs2; /* gap2 */
+ __be16 ilfact; /* Interleave factor */
+ __be16 ncyl; /* Data cylinder count */
+ __be16 nacyl; /* Alt. cylinder count */
+ __be16 ntrks; /* Tracks per cylinder */
+ __be16 nsect; /* Sectors per track */
+ __be16 obs3; /* bhead - Label head offset */
+ __be16 obs4; /* ppart - Physical Partition */
+ struct sun_partition {
+ __be32 start_cylinder;
+ __be32 num_sectors;
+ } partitions[8];
+ __be16 magic; /* Magic number */
+ __be16 csum; /* Label xor'd checksum */
+ } * label;
+ struct sun_partition *p;
+ unsigned long spc;
+ char b[BDEVNAME_SIZE];
+ int use_vtoc;
+ int nparts;
+
+ label = read_part_sector(state, 0, §);
+ if (!label)
+ return -1;
+
+ p = label->partitions;
+ if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
+/* printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
+ bdevname(bdev, b), be16_to_cpu(label->magic)); */
+ put_dev_sector(sect);
+ return 0;
+ }
+ /* Look at the checksum */
+ ush = ((__be16 *) (label+1)) - 1;
+ for (csum = 0; ush >= ((__be16 *) label);)
+ csum ^= *ush--;
+ if (csum) {
+ printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
+ bdevname(state->bdev, b));
+ put_dev_sector(sect);
+ return 0;
+ }
+
+ /* Check to see if we can use the VTOC table */
+ use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
+ (be32_to_cpu(label->vtoc.version) == 1) &&
+ (be16_to_cpu(label->vtoc.nparts) <= 8));
+
+ /* Use 8 partition entries if not specified in validated VTOC */
+ nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;
+
+ /*
+ * So that old Linux-Sun partitions continue to work,
+ * alow the VTOC to be used under the additional condition ...
+ */
+ use_vtoc = use_vtoc || !(label->vtoc.sanity ||
+ label->vtoc.version || label->vtoc.nparts);
+ spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
+ for (i = 0; i < nparts; i++, p++) {
+ unsigned long st_sector;
+ unsigned int num_sectors;
+
+ st_sector = be32_to_cpu(p->start_cylinder) * spc;
+ num_sectors = be32_to_cpu(p->num_sectors);
+ if (num_sectors) {
+ put_partition(state, slot, st_sector, num_sectors);
+ state->parts[slot].flags = 0;
+ if (use_vtoc) {
+ if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
+ state->parts[slot].flags |= ADDPART_FLAG_RAID;
+ else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
+ state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
+ }
+ }
+ slot++;
+ }
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ put_dev_sector(sect);
+ return 1;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/sun.h b/src/kernel/linux/v4.14/block/partitions/sun.h
new file mode 100644
index 0000000..2424baa
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/sun.h
@@ -0,0 +1,8 @@
+/*
+ * fs/partitions/sun.h
+ */
+
+#define SUN_LABEL_MAGIC 0xDABE
+#define SUN_VTOC_SANITY 0x600DDEEE
+
+int sun_partition(struct parsed_partitions *state);
diff --git a/src/kernel/linux/v4.14/block/partitions/sysv68.c b/src/kernel/linux/v4.14/block/partitions/sysv68.c
new file mode 100644
index 0000000..92e8108
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/sysv68.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/sysv68.c
+ *
+ * Copyright (C) 2007 Philippe De Muyter <phdm@macqel.be>
+ */
+
+#include "check.h"
+#include "sysv68.h"
+
+/*
+ * Volume ID structure: on first 256-bytes sector of disk
+ */
+
+struct volumeid {
+ u8 vid_unused[248];
+ u8 vid_mac[8]; /* ASCII string "MOTOROLA" */
+};
+
+/*
+ * config block: second 256-bytes sector on disk
+ */
+
+struct dkconfig {
+ u8 ios_unused0[128];
+ __be32 ios_slcblk; /* Slice table block number */
+ __be16 ios_slccnt; /* Number of entries in slice table */
+ u8 ios_unused1[122];
+};
+
+/*
+ * combined volumeid and dkconfig block
+ */
+
+struct dkblk0 {
+ struct volumeid dk_vid;
+ struct dkconfig dk_ios;
+};
+
+/*
+ * Slice Table Structure
+ */
+
+struct slice {
+ __be32 nblocks; /* slice size (in blocks) */
+ __be32 blkoff; /* block offset of slice */
+};
+
+
+int sysv68_partition(struct parsed_partitions *state)
+{
+ int i, slices;
+ int slot = 1;
+ Sector sect;
+ unsigned char *data;
+ struct dkblk0 *b;
+ struct slice *slice;
+ char tmp[64];
+
+ data = read_part_sector(state, 0, §);
+ if (!data)
+ return -1;
+
+ b = (struct dkblk0 *)data;
+ if (memcmp(b->dk_vid.vid_mac, "MOTOROLA", sizeof(b->dk_vid.vid_mac))) {
+ put_dev_sector(sect);
+ return 0;
+ }
+ slices = be16_to_cpu(b->dk_ios.ios_slccnt);
+ i = be32_to_cpu(b->dk_ios.ios_slcblk);
+ put_dev_sector(sect);
+
+ data = read_part_sector(state, i, §);
+ if (!data)
+ return -1;
+
+ slices -= 1; /* last slice is the whole disk */
+ snprintf(tmp, sizeof(tmp), "sysV68: %s(s%u)", state->name, slices);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ slice = (struct slice *)data;
+ for (i = 0; i < slices; i++, slice++) {
+ if (slot == state->limit)
+ break;
+ if (be32_to_cpu(slice->nblocks)) {
+ put_partition(state, slot,
+ be32_to_cpu(slice->blkoff),
+ be32_to_cpu(slice->nblocks));
+ snprintf(tmp, sizeof(tmp), "(s%u)", i);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ }
+ slot++;
+ }
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ put_dev_sector(sect);
+ return 1;
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/sysv68.h b/src/kernel/linux/v4.14/block/partitions/sysv68.h
new file mode 100644
index 0000000..bf2f5ff
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/sysv68.h
@@ -0,0 +1 @@
+extern int sysv68_partition(struct parsed_partitions *state);
diff --git a/src/kernel/linux/v4.14/block/partitions/ultrix.c b/src/kernel/linux/v4.14/block/partitions/ultrix.c
new file mode 100644
index 0000000..ecd0d73
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/ultrix.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fs/partitions/ultrix.c
+ *
+ * Code extracted from drivers/block/genhd.c
+ *
+ * Re-organised Jul 1999 Russell King
+ */
+
+#include "check.h"
+#include "ultrix.h"
+
+int ultrix_partition(struct parsed_partitions *state)
+{
+ int i;
+ Sector sect;
+ unsigned char *data;
+ struct ultrix_disklabel {
+ s32 pt_magic; /* magic no. indicating part. info exits */
+ s32 pt_valid; /* set by driver if pt is current */
+ struct pt_info {
+ s32 pi_nblocks; /* no. of sectors */
+ u32 pi_blkoff; /* block offset for start */
+ } pt_part[8];
+ } *label;
+
+#define PT_MAGIC 0x032957 /* Partition magic number */
+#define PT_VALID 1 /* Indicates if struct is valid */
+
+ data = read_part_sector(state, (16384 - sizeof(*label))/512, §);
+ if (!data)
+ return -1;
+
+ label = (struct ultrix_disklabel *)(data + 512 - sizeof(*label));
+
+ if (label->pt_magic == PT_MAGIC && label->pt_valid == PT_VALID) {
+ for (i=0; i<8; i++)
+ if (label->pt_part[i].pi_nblocks)
+ put_partition(state, i+1,
+ label->pt_part[i].pi_blkoff,
+ label->pt_part[i].pi_nblocks);
+ put_dev_sector(sect);
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+ return 1;
+ } else {
+ put_dev_sector(sect);
+ return 0;
+ }
+}
diff --git a/src/kernel/linux/v4.14/block/partitions/ultrix.h b/src/kernel/linux/v4.14/block/partitions/ultrix.h
new file mode 100644
index 0000000..a3cc00b
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/partitions/ultrix.h
@@ -0,0 +1,5 @@
+/*
+ * fs/partitions/ultrix.h
+ */
+
+int ultrix_partition(struct parsed_partitions *state);
diff --git a/src/kernel/linux/v4.14/block/scsi_ioctl.c b/src/kernel/linux/v4.14/block/scsi_ioctl.c
new file mode 100644
index 0000000..7440de4
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/scsi_ioctl.c
@@ -0,0 +1,764 @@
+/*
+ * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public Licens
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/capability.h>
+#include <linux/completion.h>
+#include <linux/cdrom.h>
+#include <linux/ratelimit.h>
+#include <linux/slab.h>
+#include <linux/times.h>
+#include <linux/uio.h>
+#include <linux/uaccess.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_ioctl.h>
+#include <scsi/scsi_cmnd.h>
+
+struct blk_cmd_filter {
+ unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
+ unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
+};
+
+static struct blk_cmd_filter blk_default_cmd_filter;
+
+/* Command group 3 is reserved and should never be used. */
+const unsigned char scsi_command_size_tbl[8] =
+{
+ 6, 10, 10, 12,
+ 16, 12, 10, 10
+};
+EXPORT_SYMBOL(scsi_command_size_tbl);
+
+#include <scsi/sg.h>
+
+static int sg_get_version(int __user *p)
+{
+ static const int sg_version_num = 30527;
+ return put_user(sg_version_num, p);
+}
+
+static int scsi_get_idlun(struct request_queue *q, int __user *p)
+{
+ return put_user(0, p);
+}
+
+static int scsi_get_bus(struct request_queue *q, int __user *p)
+{
+ return put_user(0, p);
+}
+
+static int sg_get_timeout(struct request_queue *q)
+{
+ return jiffies_to_clock_t(q->sg_timeout);
+}
+
+static int sg_set_timeout(struct request_queue *q, int __user *p)
+{
+ int timeout, err = get_user(timeout, p);
+
+ if (!err)
+ q->sg_timeout = clock_t_to_jiffies(timeout);
+
+ return err;
+}
+
+static int max_sectors_bytes(struct request_queue *q)
+{
+ unsigned int max_sectors = queue_max_sectors(q);
+
+ max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
+
+ return max_sectors << 9;
+}
+
+static int sg_get_reserved_size(struct request_queue *q, int __user *p)
+{
+ int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q));
+
+ return put_user(val, p);
+}
+
+static int sg_set_reserved_size(struct request_queue *q, int __user *p)
+{
+ int size, err = get_user(size, p);
+
+ if (err)
+ return err;
+
+ if (size < 0)
+ return -EINVAL;
+
+ q->sg_reserved_size = min(size, max_sectors_bytes(q));
+ return 0;
+}
+
+/*
+ * will always return that we are ATAPI even for a real SCSI drive, I'm not
+ * so sure this is worth doing anything about (why would you care??)
+ */
+static int sg_emulated_host(struct request_queue *q, int __user *p)
+{
+ return put_user(1, p);
+}
+
+static void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
+{
+ /* Basic read-only commands */
+ __set_bit(TEST_UNIT_READY, filter->read_ok);
+ __set_bit(REQUEST_SENSE, filter->read_ok);
+ __set_bit(READ_6, filter->read_ok);
+ __set_bit(READ_10, filter->read_ok);
+ __set_bit(READ_12, filter->read_ok);
+ __set_bit(READ_16, filter->read_ok);
+ __set_bit(READ_BUFFER, filter->read_ok);
+ __set_bit(READ_DEFECT_DATA, filter->read_ok);
+ __set_bit(READ_CAPACITY, filter->read_ok);
+ __set_bit(READ_LONG, filter->read_ok);
+ __set_bit(INQUIRY, filter->read_ok);
+ __set_bit(MODE_SENSE, filter->read_ok);
+ __set_bit(MODE_SENSE_10, filter->read_ok);
+ __set_bit(LOG_SENSE, filter->read_ok);
+ __set_bit(START_STOP, filter->read_ok);
+ __set_bit(GPCMD_VERIFY_10, filter->read_ok);
+ __set_bit(VERIFY_16, filter->read_ok);
+ __set_bit(REPORT_LUNS, filter->read_ok);
+ __set_bit(SERVICE_ACTION_IN_16, filter->read_ok);
+ __set_bit(RECEIVE_DIAGNOSTIC, filter->read_ok);
+ __set_bit(MAINTENANCE_IN, filter->read_ok);
+ __set_bit(GPCMD_READ_BUFFER_CAPACITY, filter->read_ok);
+
+ /* Audio CD commands */
+ __set_bit(GPCMD_PLAY_CD, filter->read_ok);
+ __set_bit(GPCMD_PLAY_AUDIO_10, filter->read_ok);
+ __set_bit(GPCMD_PLAY_AUDIO_MSF, filter->read_ok);
+ __set_bit(GPCMD_PLAY_AUDIO_TI, filter->read_ok);
+ __set_bit(GPCMD_PAUSE_RESUME, filter->read_ok);
+
+ /* CD/DVD data reading */
+ __set_bit(GPCMD_READ_CD, filter->read_ok);
+ __set_bit(GPCMD_READ_CD_MSF, filter->read_ok);
+ __set_bit(GPCMD_READ_DISC_INFO, filter->read_ok);
+ __set_bit(GPCMD_READ_CDVD_CAPACITY, filter->read_ok);
+ __set_bit(GPCMD_READ_DVD_STRUCTURE, filter->read_ok);
+ __set_bit(GPCMD_READ_HEADER, filter->read_ok);
+ __set_bit(GPCMD_READ_TRACK_RZONE_INFO, filter->read_ok);
+ __set_bit(GPCMD_READ_SUBCHANNEL, filter->read_ok);
+ __set_bit(GPCMD_READ_TOC_PMA_ATIP, filter->read_ok);
+ __set_bit(GPCMD_REPORT_KEY, filter->read_ok);
+ __set_bit(GPCMD_SCAN, filter->read_ok);
+ __set_bit(GPCMD_GET_CONFIGURATION, filter->read_ok);
+ __set_bit(GPCMD_READ_FORMAT_CAPACITIES, filter->read_ok);
+ __set_bit(GPCMD_GET_EVENT_STATUS_NOTIFICATION, filter->read_ok);
+ __set_bit(GPCMD_GET_PERFORMANCE, filter->read_ok);
+ __set_bit(GPCMD_SEEK, filter->read_ok);
+ __set_bit(GPCMD_STOP_PLAY_SCAN, filter->read_ok);
+
+ /* Basic writing commands */
+ __set_bit(WRITE_6, filter->write_ok);
+ __set_bit(WRITE_10, filter->write_ok);
+ __set_bit(WRITE_VERIFY, filter->write_ok);
+ __set_bit(WRITE_12, filter->write_ok);
+ __set_bit(WRITE_VERIFY_12, filter->write_ok);
+ __set_bit(WRITE_16, filter->write_ok);
+ __set_bit(WRITE_LONG, filter->write_ok);
+ __set_bit(WRITE_LONG_2, filter->write_ok);
+ __set_bit(WRITE_SAME, filter->write_ok);
+ __set_bit(WRITE_SAME_16, filter->write_ok);
+ __set_bit(WRITE_SAME_32, filter->write_ok);
+ __set_bit(ERASE, filter->write_ok);
+ __set_bit(GPCMD_MODE_SELECT_10, filter->write_ok);
+ __set_bit(MODE_SELECT, filter->write_ok);
+ __set_bit(LOG_SELECT, filter->write_ok);
+ __set_bit(GPCMD_BLANK, filter->write_ok);
+ __set_bit(GPCMD_CLOSE_TRACK, filter->write_ok);
+ __set_bit(GPCMD_FLUSH_CACHE, filter->write_ok);
+ __set_bit(GPCMD_FORMAT_UNIT, filter->write_ok);
+ __set_bit(GPCMD_REPAIR_RZONE_TRACK, filter->write_ok);
+ __set_bit(GPCMD_RESERVE_RZONE_TRACK, filter->write_ok);
+ __set_bit(GPCMD_SEND_DVD_STRUCTURE, filter->write_ok);
+ __set_bit(GPCMD_SEND_EVENT, filter->write_ok);
+ __set_bit(GPCMD_SEND_KEY, filter->write_ok);
+ __set_bit(GPCMD_SEND_OPC, filter->write_ok);
+ __set_bit(GPCMD_SEND_CUE_SHEET, filter->write_ok);
+ __set_bit(GPCMD_SET_SPEED, filter->write_ok);
+ __set_bit(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL, filter->write_ok);
+ __set_bit(GPCMD_LOAD_UNLOAD, filter->write_ok);
+ __set_bit(GPCMD_SET_STREAMING, filter->write_ok);
+ __set_bit(GPCMD_SET_READ_AHEAD, filter->write_ok);
+}
+
+int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm)
+{
+ struct blk_cmd_filter *filter = &blk_default_cmd_filter;
+
+ /* root can do any command. */
+ if (capable(CAP_SYS_RAWIO))
+ return 0;
+
+ /* Anybody who can open the device can do a read-safe command */
+ if (test_bit(cmd[0], filter->read_ok))
+ return 0;
+
+ /* Write-safe commands require a writable open */
+ if (test_bit(cmd[0], filter->write_ok) && has_write_perm)
+ return 0;
+
+ return -EPERM;
+}
+EXPORT_SYMBOL(blk_verify_command);
+
+static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
+ struct sg_io_hdr *hdr, fmode_t mode)
+{
+ struct scsi_request *req = scsi_req(rq);
+
+ if (copy_from_user(req->cmd, hdr->cmdp, hdr->cmd_len))
+ return -EFAULT;
+ if (blk_verify_command(req->cmd, mode & FMODE_WRITE))
+ return -EPERM;
+
+ /*
+ * fill in request structure
+ */
+ req->cmd_len = hdr->cmd_len;
+
+ rq->timeout = msecs_to_jiffies(hdr->timeout);
+ if (!rq->timeout)
+ rq->timeout = q->sg_timeout;
+ if (!rq->timeout)
+ rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
+ if (rq->timeout < BLK_MIN_SG_TIMEOUT)
+ rq->timeout = BLK_MIN_SG_TIMEOUT;
+
+ return 0;
+}
+
+static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
+ struct bio *bio)
+{
+ struct scsi_request *req = scsi_req(rq);
+ int r, ret = 0;
+
+ /*
+ * fill in all the output members
+ */
+ hdr->status = req->result & 0xff;
+ hdr->masked_status = status_byte(req->result);
+ hdr->msg_status = msg_byte(req->result);
+ hdr->host_status = host_byte(req->result);
+ hdr->driver_status = driver_byte(req->result);
+ hdr->info = 0;
+ if (hdr->masked_status || hdr->host_status || hdr->driver_status)
+ hdr->info |= SG_INFO_CHECK;
+ hdr->resid = req->resid_len;
+ hdr->sb_len_wr = 0;
+
+ if (req->sense_len && hdr->sbp) {
+ int len = min((unsigned int) hdr->mx_sb_len, req->sense_len);
+
+ if (!copy_to_user(hdr->sbp, req->sense, len))
+ hdr->sb_len_wr = len;
+ else
+ ret = -EFAULT;
+ }
+
+ r = blk_rq_unmap_user(bio);
+ if (!ret)
+ ret = r;
+
+ return ret;
+}
+
+static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
+ struct sg_io_hdr *hdr, fmode_t mode)
+{
+ unsigned long start_time;
+ ssize_t ret = 0;
+ int writing = 0;
+ int at_head = 0;
+ struct request *rq;
+ struct scsi_request *req;
+ struct bio *bio;
+
+ if (hdr->interface_id != 'S')
+ return -EINVAL;
+
+ if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
+ return -EIO;
+
+ if (hdr->dxfer_len)
+ switch (hdr->dxfer_direction) {
+ default:
+ return -EINVAL;
+ case SG_DXFER_TO_DEV:
+ writing = 1;
+ break;
+ case SG_DXFER_TO_FROM_DEV:
+ case SG_DXFER_FROM_DEV:
+ break;
+ }
+ if (hdr->flags & SG_FLAG_Q_AT_HEAD)
+ at_head = 1;
+
+ ret = -ENOMEM;
+ rq = blk_get_request(q, writing ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
+ GFP_KERNEL);
+ if (IS_ERR(rq))
+ return PTR_ERR(rq);
+ req = scsi_req(rq);
+
+ if (hdr->cmd_len > BLK_MAX_CDB) {
+ req->cmd = kzalloc(hdr->cmd_len, GFP_KERNEL);
+ if (!req->cmd)
+ goto out_put_request;
+ }
+
+ ret = blk_fill_sghdr_rq(q, rq, hdr, mode);
+ if (ret < 0)
+ goto out_free_cdb;
+
+ ret = 0;
+ if (hdr->iovec_count) {
+ struct iov_iter i;
+ struct iovec *iov = NULL;
+
+ ret = import_iovec(rq_data_dir(rq),
+ hdr->dxferp, hdr->iovec_count,
+ 0, &iov, &i);
+ if (ret < 0)
+ goto out_free_cdb;
+
+ /* SG_IO howto says that the shorter of the two wins */
+ iov_iter_truncate(&i, hdr->dxfer_len);
+
+ ret = blk_rq_map_user_iov(q, rq, NULL, &i, GFP_KERNEL);
+ kfree(iov);
+ } else if (hdr->dxfer_len)
+ ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
+ GFP_KERNEL);
+
+ if (ret)
+ goto out_free_cdb;
+
+ bio = rq->bio;
+ req->retries = 0;
+
+ start_time = jiffies;
+
+ /* ignore return value. All information is passed back to caller
+ * (if he doesn't check that is his problem).
+ * N.B. a non-zero SCSI status is _not_ necessarily an error.
+ */
+ blk_execute_rq(q, bd_disk, rq, at_head);
+
+ hdr->duration = jiffies_to_msecs(jiffies - start_time);
+
+ ret = blk_complete_sghdr_rq(rq, hdr, bio);
+
+out_free_cdb:
+ scsi_req_free_cmd(req);
+out_put_request:
+ blk_put_request(rq);
+ return ret;
+}
+
+/**
+ * sg_scsi_ioctl -- handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
+ * @file: file this ioctl operates on (optional)
+ * @q: request queue to send scsi commands down
+ * @disk: gendisk to operate on (option)
+ * @sic: userspace structure describing the command to perform
+ *
+ * Send down the scsi command described by @sic to the device below
+ * the request queue @q. If @file is non-NULL it's used to perform
+ * fine-grained permission checks that allow users to send down
+ * non-destructive SCSI commands. If the caller has a struct gendisk
+ * available it should be passed in as @disk to allow the low level
+ * driver to use the information contained in it. A non-NULL @disk
+ * is only allowed if the caller knows that the low level driver doesn't
+ * need it (e.g. in the scsi subsystem).
+ *
+ * Notes:
+ * - This interface is deprecated - users should use the SG_IO
+ * interface instead, as this is a more flexible approach to
+ * performing SCSI commands on a device.
+ * - The SCSI command length is determined by examining the 1st byte
+ * of the given command. There is no way to override this.
+ * - Data transfers are limited to PAGE_SIZE
+ * - The length (x + y) must be at least OMAX_SB_LEN bytes long to
+ * accommodate the sense buffer when an error occurs.
+ * The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
+ * old code will not be surprised.
+ * - If a Unix error occurs (e.g. ENOMEM) then the user will receive
+ * a negative return and the Unix error code in 'errno'.
+ * If the SCSI command succeeds then 0 is returned.
+ * Positive numbers returned are the compacted SCSI error codes (4
+ * bytes in one int) where the lowest byte is the SCSI status.
+ */
+#define OMAX_SB_LEN 16 /* For backward compatibility */
+int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
+ struct scsi_ioctl_command __user *sic)
+{
+ struct request *rq;
+ struct scsi_request *req;
+ int err;
+ unsigned int in_len, out_len, bytes, opcode, cmdlen;
+ char *buffer = NULL;
+
+ if (!sic)
+ return -EINVAL;
+
+ /*
+ * get in an out lengths, verify they don't exceed a page worth of data
+ */
+ if (get_user(in_len, &sic->inlen))
+ return -EFAULT;
+ if (get_user(out_len, &sic->outlen))
+ return -EFAULT;
+ if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
+ return -EINVAL;
+ if (get_user(opcode, sic->data))
+ return -EFAULT;
+
+ bytes = max(in_len, out_len);
+ if (bytes) {
+ buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
+ if (!buffer)
+ return -ENOMEM;
+
+ }
+
+ rq = blk_get_request(q, in_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
+ __GFP_RECLAIM);
+ if (IS_ERR(rq)) {
+ err = PTR_ERR(rq);
+ goto error_free_buffer;
+ }
+ req = scsi_req(rq);
+
+ cmdlen = COMMAND_SIZE(opcode);
+
+ /*
+ * get command and data to send to device, if any
+ */
+ err = -EFAULT;
+ req->cmd_len = cmdlen;
+ if (copy_from_user(req->cmd, sic->data, cmdlen))
+ goto error;
+
+ if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
+ goto error;
+
+ err = blk_verify_command(req->cmd, mode & FMODE_WRITE);
+ if (err)
+ goto error;
+
+ /* default. possible overriden later */
+ req->retries = 5;
+
+ switch (opcode) {
+ case SEND_DIAGNOSTIC:
+ case FORMAT_UNIT:
+ rq->timeout = FORMAT_UNIT_TIMEOUT;
+ req->retries = 1;
+ break;
+ case START_STOP:
+ rq->timeout = START_STOP_TIMEOUT;
+ break;
+ case MOVE_MEDIUM:
+ rq->timeout = MOVE_MEDIUM_TIMEOUT;
+ break;
+ case READ_ELEMENT_STATUS:
+ rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
+ break;
+ case READ_DEFECT_DATA:
+ rq->timeout = READ_DEFECT_DATA_TIMEOUT;
+ req->retries = 1;
+ break;
+ default:
+ rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
+ break;
+ }
+
+ if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_RECLAIM)) {
+ err = DRIVER_ERROR << 24;
+ goto error;
+ }
+
+ blk_execute_rq(q, disk, rq, 0);
+
+ err = req->result & 0xff; /* only 8 bit SCSI status */
+ if (err) {
+ if (req->sense_len && req->sense) {
+ bytes = (OMAX_SB_LEN > req->sense_len) ?
+ req->sense_len : OMAX_SB_LEN;
+ if (copy_to_user(sic->data, req->sense, bytes))
+ err = -EFAULT;
+ }
+ } else {
+ if (copy_to_user(sic->data, buffer, out_len))
+ err = -EFAULT;
+ }
+
+error:
+ blk_put_request(rq);
+
+error_free_buffer:
+ kfree(buffer);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(sg_scsi_ioctl);
+
+/* Send basic block requests */
+static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
+ int cmd, int data)
+{
+ struct request *rq;
+ int err;
+
+ rq = blk_get_request(q, REQ_OP_SCSI_OUT, __GFP_RECLAIM);
+ if (IS_ERR(rq))
+ return PTR_ERR(rq);
+ rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
+ scsi_req(rq)->cmd[0] = cmd;
+ scsi_req(rq)->cmd[4] = data;
+ scsi_req(rq)->cmd_len = 6;
+ blk_execute_rq(q, bd_disk, rq, 0);
+ err = scsi_req(rq)->result ? -EIO : 0;
+ blk_put_request(rq);
+
+ return err;
+}
+
+static inline int blk_send_start_stop(struct request_queue *q,
+ struct gendisk *bd_disk, int data)
+{
+ return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
+}
+
+int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mode,
+ unsigned int cmd, void __user *arg)
+{
+ int err;
+
+ if (!q)
+ return -ENXIO;
+
+ switch (cmd) {
+ /*
+ * new sgv3 interface
+ */
+ case SG_GET_VERSION_NUM:
+ err = sg_get_version(arg);
+ break;
+ case SCSI_IOCTL_GET_IDLUN:
+ err = scsi_get_idlun(q, arg);
+ break;
+ case SCSI_IOCTL_GET_BUS_NUMBER:
+ err = scsi_get_bus(q, arg);
+ break;
+ case SG_SET_TIMEOUT:
+ err = sg_set_timeout(q, arg);
+ break;
+ case SG_GET_TIMEOUT:
+ err = sg_get_timeout(q);
+ break;
+ case SG_GET_RESERVED_SIZE:
+ err = sg_get_reserved_size(q, arg);
+ break;
+ case SG_SET_RESERVED_SIZE:
+ err = sg_set_reserved_size(q, arg);
+ break;
+ case SG_EMULATED_HOST:
+ err = sg_emulated_host(q, arg);
+ break;
+ case SG_IO: {
+ struct sg_io_hdr hdr;
+
+ err = -EFAULT;
+ if (copy_from_user(&hdr, arg, sizeof(hdr)))
+ break;
+ err = sg_io(q, bd_disk, &hdr, mode);
+ if (err == -EFAULT)
+ break;
+
+ if (copy_to_user(arg, &hdr, sizeof(hdr)))
+ err = -EFAULT;
+ break;
+ }
+ case CDROM_SEND_PACKET: {
+ struct cdrom_generic_command cgc;
+ struct sg_io_hdr hdr;
+
+ err = -EFAULT;
+ if (copy_from_user(&cgc, arg, sizeof(cgc)))
+ break;
+ cgc.timeout = clock_t_to_jiffies(cgc.timeout);
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.interface_id = 'S';
+ hdr.cmd_len = sizeof(cgc.cmd);
+ hdr.dxfer_len = cgc.buflen;
+ err = 0;
+ switch (cgc.data_direction) {
+ case CGC_DATA_UNKNOWN:
+ hdr.dxfer_direction = SG_DXFER_UNKNOWN;
+ break;
+ case CGC_DATA_WRITE:
+ hdr.dxfer_direction = SG_DXFER_TO_DEV;
+ break;
+ case CGC_DATA_READ:
+ hdr.dxfer_direction = SG_DXFER_FROM_DEV;
+ break;
+ case CGC_DATA_NONE:
+ hdr.dxfer_direction = SG_DXFER_NONE;
+ break;
+ default:
+ err = -EINVAL;
+ }
+ if (err)
+ break;
+
+ hdr.dxferp = cgc.buffer;
+ hdr.sbp = cgc.sense;
+ if (hdr.sbp)
+ hdr.mx_sb_len = sizeof(struct request_sense);
+ hdr.timeout = jiffies_to_msecs(cgc.timeout);
+ hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
+ hdr.cmd_len = sizeof(cgc.cmd);
+
+ err = sg_io(q, bd_disk, &hdr, mode);
+ if (err == -EFAULT)
+ break;
+
+ if (hdr.status)
+ err = -EIO;
+
+ cgc.stat = err;
+ cgc.buflen = hdr.resid;
+ if (copy_to_user(arg, &cgc, sizeof(cgc)))
+ err = -EFAULT;
+
+ break;
+ }
+
+ /*
+ * old junk scsi send command ioctl
+ */
+ case SCSI_IOCTL_SEND_COMMAND:
+ printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
+ err = -EINVAL;
+ if (!arg)
+ break;
+
+ err = sg_scsi_ioctl(q, bd_disk, mode, arg);
+ break;
+ case CDROMCLOSETRAY:
+ err = blk_send_start_stop(q, bd_disk, 0x03);
+ break;
+ case CDROMEJECT:
+ err = blk_send_start_stop(q, bd_disk, 0x02);
+ break;
+ default:
+ err = -ENOTTY;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL(scsi_cmd_ioctl);
+
+int scsi_verify_blk_ioctl(struct block_device *bd, unsigned int cmd)
+{
+ if (bd && bd == bd->bd_contains)
+ return 0;
+
+ /* Actually none of these is particularly useful on a partition,
+ * but they are safe.
+ */
+ switch (cmd) {
+ case SCSI_IOCTL_GET_IDLUN:
+ case SCSI_IOCTL_GET_BUS_NUMBER:
+ case SCSI_IOCTL_GET_PCI:
+ case SCSI_IOCTL_PROBE_HOST:
+ case SG_GET_VERSION_NUM:
+ case SG_SET_TIMEOUT:
+ case SG_GET_TIMEOUT:
+ case SG_GET_RESERVED_SIZE:
+ case SG_SET_RESERVED_SIZE:
+ case SG_EMULATED_HOST:
+ return 0;
+ case CDROM_GET_CAPABILITY:
+ /* Keep this until we remove the printk below. udev sends it
+ * and we do not want to spam dmesg about it. CD-ROMs do
+ * not have partitions, so we get here only for disks.
+ */
+ return -ENOIOCTLCMD;
+ default:
+ break;
+ }
+
+ if (capable(CAP_SYS_RAWIO))
+ return 0;
+
+ /* In particular, rule out all resets and host-specific ioctls. */
+ printk_ratelimited(KERN_WARNING
+ "%s: sending ioctl %x to a partition!\n", current->comm, cmd);
+
+ return -ENOIOCTLCMD;
+}
+EXPORT_SYMBOL(scsi_verify_blk_ioctl);
+
+int scsi_cmd_blk_ioctl(struct block_device *bd, fmode_t mode,
+ unsigned int cmd, void __user *arg)
+{
+ int ret;
+
+ ret = scsi_verify_blk_ioctl(bd, cmd);
+ if (ret < 0)
+ return ret;
+
+ return scsi_cmd_ioctl(bd->bd_disk->queue, bd->bd_disk, mode, cmd, arg);
+}
+EXPORT_SYMBOL(scsi_cmd_blk_ioctl);
+
+/**
+ * scsi_req_init - initialize certain fields of a scsi_request structure
+ * @req: Pointer to a scsi_request structure.
+ * Initializes .__cmd[], .cmd, .cmd_len and .sense_len but no other members
+ * of struct scsi_request.
+ */
+void scsi_req_init(struct scsi_request *req)
+{
+ memset(req->__cmd, 0, sizeof(req->__cmd));
+ req->cmd = req->__cmd;
+ req->cmd_len = BLK_MAX_CDB;
+ req->sense_len = 0;
+}
+EXPORT_SYMBOL(scsi_req_init);
+
+static int __init blk_scsi_ioctl_init(void)
+{
+ blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
+ return 0;
+}
+fs_initcall(blk_scsi_ioctl_init);
diff --git a/src/kernel/linux/v4.14/block/sed-opal.c b/src/kernel/linux/v4.14/block/sed-opal.c
new file mode 100644
index 0000000..c64011c
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/sed-opal.c
@@ -0,0 +1,2449 @@
+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * Authors:
+ * Scott Bauer <scott.bauer@intel.com>
+ * Rafael Antognolli <rafael.antognolli@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":OPAL: " fmt
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/genhd.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <uapi/linux/sed-opal.h>
+#include <linux/sed-opal.h>
+#include <linux/string.h>
+#include <linux/kdev_t.h>
+
+#include "opal_proto.h"
+
+#define IO_BUFFER_LENGTH 2048
+#define MAX_TOKS 64
+
+struct opal_step {
+ int (*fn)(struct opal_dev *dev, void *data);
+ void *data;
+};
+typedef int (cont_fn)(struct opal_dev *dev);
+
+enum opal_atom_width {
+ OPAL_WIDTH_TINY,
+ OPAL_WIDTH_SHORT,
+ OPAL_WIDTH_MEDIUM,
+ OPAL_WIDTH_LONG,
+ OPAL_WIDTH_TOKEN
+};
+
+/*
+ * On the parsed response, we don't store again the toks that are already
+ * stored in the response buffer. Instead, for each token, we just store a
+ * pointer to the position in the buffer where the token starts, and the size
+ * of the token in bytes.
+ */
+struct opal_resp_tok {
+ const u8 *pos;
+ size_t len;
+ enum opal_response_token type;
+ enum opal_atom_width width;
+ union {
+ u64 u;
+ s64 s;
+ } stored;
+};
+
+/*
+ * From the response header it's not possible to know how many tokens there are
+ * on the payload. So we hardcode that the maximum will be MAX_TOKS, and later
+ * if we start dealing with messages that have more than that, we can increase
+ * this number. This is done to avoid having to make two passes through the
+ * response, the first one counting how many tokens we have and the second one
+ * actually storing the positions.
+ */
+struct parsed_resp {
+ int num;
+ struct opal_resp_tok toks[MAX_TOKS];
+};
+
+struct opal_dev {
+ bool supported;
+ bool mbr_enabled;
+
+ void *data;
+ sec_send_recv *send_recv;
+
+ const struct opal_step *steps;
+ struct mutex dev_lock;
+ u16 comid;
+ u32 hsn;
+ u32 tsn;
+ u64 align;
+ u64 lowest_lba;
+
+ size_t pos;
+ u8 cmd[IO_BUFFER_LENGTH];
+ u8 resp[IO_BUFFER_LENGTH];
+
+ struct parsed_resp parsed;
+ size_t prev_d_len;
+ void *prev_data;
+
+ struct list_head unlk_lst;
+};
+
+
+static const u8 opaluid[][OPAL_UID_LENGTH] = {
+ /* users */
+ [OPAL_SMUID_UID] =
+ { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff },
+ [OPAL_THISSP_UID] =
+ { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
+ [OPAL_ADMINSP_UID] =
+ { 0x00, 0x00, 0x02, 0x05, 0x00, 0x00, 0x00, 0x01 },
+ [OPAL_LOCKINGSP_UID] =
+ { 0x00, 0x00, 0x02, 0x05, 0x00, 0x00, 0x00, 0x02 },
+ [OPAL_ENTERPRISE_LOCKINGSP_UID] =
+ { 0x00, 0x00, 0x02, 0x05, 0x00, 0x01, 0x00, 0x01 },
+ [OPAL_ANYBODY_UID] =
+ { 0x00, 0x00, 0x00, 0x09, 0x00, 0x00, 0x00, 0x01 },
+ [OPAL_SID_UID] =
+ { 0x00, 0x00, 0x00, 0x09, 0x00, 0x00, 0x00, 0x06 },
+ [OPAL_ADMIN1_UID] =
+ { 0x00, 0x00, 0x00, 0x09, 0x00, 0x01, 0x00, 0x01 },
+ [OPAL_USER1_UID] =
+ { 0x00, 0x00, 0x00, 0x09, 0x00, 0x03, 0x00, 0x01 },
+ [OPAL_USER2_UID] =
+ { 0x00, 0x00, 0x00, 0x09, 0x00, 0x03, 0x00, 0x02 },
+ [OPAL_PSID_UID] =
+ { 0x00, 0x00, 0x00, 0x09, 0x00, 0x01, 0xff, 0x01 },
+ [OPAL_ENTERPRISE_BANDMASTER0_UID] =
+ { 0x00, 0x00, 0x00, 0x09, 0x00, 0x00, 0x80, 0x01 },
+ [OPAL_ENTERPRISE_ERASEMASTER_UID] =
+ { 0x00, 0x00, 0x00, 0x09, 0x00, 0x00, 0x84, 0x01 },
+
+ /* tables */
+
+ [OPAL_LOCKINGRANGE_GLOBAL] =
+ { 0x00, 0x00, 0x08, 0x02, 0x00, 0x00, 0x00, 0x01 },
+ [OPAL_LOCKINGRANGE_ACE_RDLOCKED] =
+ { 0x00, 0x00, 0x00, 0x08, 0x00, 0x03, 0xE0, 0x01 },
+ [OPAL_LOCKINGRANGE_ACE_WRLOCKED] =
+ { 0x00, 0x00, 0x00, 0x08, 0x00, 0x03, 0xE8, 0x01 },
+ [OPAL_MBRCONTROL] =
+ { 0x00, 0x00, 0x08, 0x03, 0x00, 0x00, 0x00, 0x01 },
+ [OPAL_MBR] =
+ { 0x00, 0x00, 0x08, 0x04, 0x00, 0x00, 0x00, 0x00 },
+ [OPAL_AUTHORITY_TABLE] =
+ { 0x00, 0x00, 0x00, 0x09, 0x00, 0x00, 0x00, 0x00},
+ [OPAL_C_PIN_TABLE] =
+ { 0x00, 0x00, 0x00, 0x0B, 0x00, 0x00, 0x00, 0x00},
+ [OPAL_LOCKING_INFO_TABLE] =
+ { 0x00, 0x00, 0x08, 0x01, 0x00, 0x00, 0x00, 0x01 },
+ [OPAL_ENTERPRISE_LOCKING_INFO_TABLE] =
+ { 0x00, 0x00, 0x08, 0x01, 0x00, 0x00, 0x00, 0x00 },
+
+ /* C_PIN_TABLE object ID's */
+
+ [OPAL_C_PIN_MSID] =
+ { 0x00, 0x00, 0x00, 0x0B, 0x00, 0x00, 0x84, 0x02},
+ [OPAL_C_PIN_SID] =
+ { 0x00, 0x00, 0x00, 0x0B, 0x00, 0x00, 0x00, 0x01},
+ [OPAL_C_PIN_ADMIN1] =
+ { 0x00, 0x00, 0x00, 0x0B, 0x00, 0x01, 0x00, 0x01},
+
+ /* half UID's (only first 4 bytes used) */
+
+ [OPAL_HALF_UID_AUTHORITY_OBJ_REF] =
+ { 0x00, 0x00, 0x0C, 0x05, 0xff, 0xff, 0xff, 0xff },
+ [OPAL_HALF_UID_BOOLEAN_ACE] =
+ { 0x00, 0x00, 0x04, 0x0E, 0xff, 0xff, 0xff, 0xff },
+
+ /* special value for omitted optional parameter */
+ [OPAL_UID_HEXFF] =
+ { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
+};
+
+/*
+ * TCG Storage SSC Methods.
+ * Derived from: TCG_Storage_Architecture_Core_Spec_v2.01_r1.00
+ * Section: 6.3 Assigned UIDs
+ */
+static const u8 opalmethod[][OPAL_UID_LENGTH] = {
+ [OPAL_PROPERTIES] =
+ { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0x01 },
+ [OPAL_STARTSESSION] =
+ { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0x02 },
+ [OPAL_REVERT] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x02, 0x02 },
+ [OPAL_ACTIVATE] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x02, 0x03 },
+ [OPAL_EGET] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x06 },
+ [OPAL_ESET] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x07 },
+ [OPAL_NEXT] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x08 },
+ [OPAL_EAUTHENTICATE] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x0c },
+ [OPAL_GETACL] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x0d },
+ [OPAL_GENKEY] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x10 },
+ [OPAL_REVERTSP] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x11 },
+ [OPAL_GET] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x16 },
+ [OPAL_SET] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x17 },
+ [OPAL_AUTHENTICATE] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x1c },
+ [OPAL_RANDOM] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x06, 0x01 },
+ [OPAL_ERASE] =
+ { 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x08, 0x03 },
+};
+
+static int end_opal_session_error(struct opal_dev *dev);
+
+struct opal_suspend_data {
+ struct opal_lock_unlock unlk;
+ u8 lr;
+ struct list_head node;
+};
+
+/*
+ * Derived from:
+ * TCG_Storage_Architecture_Core_Spec_v2.01_r1.00
+ * Section: 5.1.5 Method Status Codes
+ */
+static const char * const opal_errors[] = {
+ "Success",
+ "Not Authorized",
+ "Unknown Error",
+ "SP Busy",
+ "SP Failed",
+ "SP Disabled",
+ "SP Frozen",
+ "No Sessions Available",
+ "Uniqueness Conflict",
+ "Insufficient Space",
+ "Insufficient Rows",
+ "Invalid Function",
+ "Invalid Parameter",
+ "Invalid Reference",
+ "Unknown Error",
+ "TPER Malfunction",
+ "Transaction Failure",
+ "Response Overflow",
+ "Authority Locked Out",
+};
+
+static const char *opal_error_to_human(int error)
+{
+ if (error == 0x3f)
+ return "Failed";
+
+ if (error >= ARRAY_SIZE(opal_errors) || error < 0)
+ return "Unknown Error";
+
+ return opal_errors[error];
+}
+
+static void print_buffer(const u8 *ptr, u32 length)
+{
+#ifdef DEBUG
+ print_hex_dump_bytes("OPAL: ", DUMP_PREFIX_OFFSET, ptr, length);
+ pr_debug("\n");
+#endif
+}
+
+static bool check_tper(const void *data)
+{
+ const struct d0_tper_features *tper = data;
+ u8 flags = tper->supported_features;
+
+ if (!(flags & TPER_SYNC_SUPPORTED)) {
+ pr_debug("TPer sync not supported. flags = %d\n",
+ tper->supported_features);
+ return false;
+ }
+
+ return true;
+}
+
+static bool check_mbrenabled(const void *data)
+{
+ const struct d0_locking_features *lfeat = data;
+ u8 sup_feat = lfeat->supported_features;
+
+ return !!(sup_feat & MBR_ENABLED_MASK);
+}
+
+static bool check_sum(const void *data)
+{
+ const struct d0_single_user_mode *sum = data;
+ u32 nlo = be32_to_cpu(sum->num_locking_objects);
+
+ if (nlo == 0) {
+ pr_debug("Need at least one locking object.\n");
+ return false;
+ }
+
+ pr_debug("Number of locking objects: %d\n", nlo);
+
+ return true;
+}
+
+static u16 get_comid_v100(const void *data)
+{
+ const struct d0_opal_v100 *v100 = data;
+
+ return be16_to_cpu(v100->baseComID);
+}
+
+static u16 get_comid_v200(const void *data)
+{
+ const struct d0_opal_v200 *v200 = data;
+
+ return be16_to_cpu(v200->baseComID);
+}
+
+static int opal_send_cmd(struct opal_dev *dev)
+{
+ return dev->send_recv(dev->data, dev->comid, TCG_SECP_01,
+ dev->cmd, IO_BUFFER_LENGTH,
+ true);
+}
+
+static int opal_recv_cmd(struct opal_dev *dev)
+{
+ return dev->send_recv(dev->data, dev->comid, TCG_SECP_01,
+ dev->resp, IO_BUFFER_LENGTH,
+ false);
+}
+
+static int opal_recv_check(struct opal_dev *dev)
+{
+ size_t buflen = IO_BUFFER_LENGTH;
+ void *buffer = dev->resp;
+ struct opal_header *hdr = buffer;
+ int ret;
+
+ do {
+ pr_debug("Sent OPAL command: outstanding=%d, minTransfer=%d\n",
+ hdr->cp.outstandingData,
+ hdr->cp.minTransfer);
+
+ if (hdr->cp.outstandingData == 0 ||
+ hdr->cp.minTransfer != 0)
+ return 0;
+
+ memset(buffer, 0, buflen);
+ ret = opal_recv_cmd(dev);
+ } while (!ret);
+
+ return ret;
+}
+
+static int opal_send_recv(struct opal_dev *dev, cont_fn *cont)
+{
+ int ret;
+
+ ret = opal_send_cmd(dev);
+ if (ret)
+ return ret;
+ ret = opal_recv_cmd(dev);
+ if (ret)
+ return ret;
+ ret = opal_recv_check(dev);
+ if (ret)
+ return ret;
+ return cont(dev);
+}
+
+static void check_geometry(struct opal_dev *dev, const void *data)
+{
+ const struct d0_geometry_features *geo = data;
+
+ dev->align = geo->alignment_granularity;
+ dev->lowest_lba = geo->lowest_aligned_lba;
+}
+
+static int next(struct opal_dev *dev)
+{
+ const struct opal_step *step;
+ int state = 0, error = 0;
+
+ do {
+ step = &dev->steps[state];
+ if (!step->fn)
+ break;
+
+ error = step->fn(dev, step->data);
+ if (error) {
+ pr_debug("Error on step function: %d with error %d: %s\n",
+ state, error,
+ opal_error_to_human(error));
+
+ /* For each OPAL command we do a discovery0 then we
+ * start some sort of session.
+ * If we haven't passed state 1 then there was an error
+ * on discovery0 or during the attempt to start a
+ * session. Therefore we shouldn't attempt to terminate
+ * a session, as one has not yet been created.
+ */
+ if (state > 1) {
+ end_opal_session_error(dev);
+ return error;
+ }
+
+ }
+ state++;
+ } while (!error);
+
+ return error;
+}
+
+static int opal_discovery0_end(struct opal_dev *dev)
+{
+ bool found_com_id = false, supported = true, single_user = false;
+ const struct d0_header *hdr = (struct d0_header *)dev->resp;
+ const u8 *epos = dev->resp, *cpos = dev->resp;
+ u16 comid = 0;
+ u32 hlen = be32_to_cpu(hdr->length);
+
+ print_buffer(dev->resp, hlen);
+ dev->mbr_enabled = false;
+
+ if (hlen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
+ pr_debug("Discovery length overflows buffer (%zu+%u)/%u\n",
+ sizeof(*hdr), hlen, IO_BUFFER_LENGTH);
+ return -EFAULT;
+ }
+
+ epos += hlen; /* end of buffer */
+ cpos += sizeof(*hdr); /* current position on buffer */
+
+ while (cpos < epos && supported) {
+ const struct d0_features *body =
+ (const struct d0_features *)cpos;
+
+ switch (be16_to_cpu(body->code)) {
+ case FC_TPER:
+ supported = check_tper(body->features);
+ break;
+ case FC_SINGLEUSER:
+ single_user = check_sum(body->features);
+ break;
+ case FC_GEOMETRY:
+ check_geometry(dev, body);
+ break;
+ case FC_LOCKING:
+ dev->mbr_enabled = check_mbrenabled(body->features);
+ break;
+ case FC_ENTERPRISE:
+ case FC_DATASTORE:
+ /* some ignored properties */
+ pr_debug("Found OPAL feature description: %d\n",
+ be16_to_cpu(body->code));
+ break;
+ case FC_OPALV100:
+ comid = get_comid_v100(body->features);
+ found_com_id = true;
+ break;
+ case FC_OPALV200:
+ comid = get_comid_v200(body->features);
+ found_com_id = true;
+ break;
+ case 0xbfff ... 0xffff:
+ /* vendor specific, just ignore */
+ break;
+ default:
+ pr_debug("OPAL Unknown feature: %d\n",
+ be16_to_cpu(body->code));
+
+ }
+ cpos += body->length + 4;
+ }
+
+ if (!supported) {
+ pr_debug("This device is not Opal enabled. Not Supported!\n");
+ return -EOPNOTSUPP;
+ }
+
+ if (!single_user)
+ pr_debug("Device doesn't support single user mode\n");
+
+
+ if (!found_com_id) {
+ pr_debug("Could not find OPAL comid for device. Returning early\n");
+ return -EOPNOTSUPP;;
+ }
+
+ dev->comid = comid;
+
+ return 0;
+}
+
+static int opal_discovery0(struct opal_dev *dev, void *data)
+{
+ int ret;
+
+ memset(dev->resp, 0, IO_BUFFER_LENGTH);
+ dev->comid = OPAL_DISCOVERY_COMID;
+ ret = opal_recv_cmd(dev);
+ if (ret)
+ return ret;
+ return opal_discovery0_end(dev);
+}
+
+static void add_token_u8(int *err, struct opal_dev *cmd, u8 tok)
+{
+ if (*err)
+ return;
+ if (cmd->pos >= IO_BUFFER_LENGTH - 1) {
+ pr_debug("Error adding u8: end of buffer.\n");
+ *err = -ERANGE;
+ return;
+ }
+ cmd->cmd[cmd->pos++] = tok;
+}
+
+static void add_short_atom_header(struct opal_dev *cmd, bool bytestring,
+ bool has_sign, int len)
+{
+ u8 atom;
+ int err = 0;
+
+ atom = SHORT_ATOM_ID;
+ atom |= bytestring ? SHORT_ATOM_BYTESTRING : 0;
+ atom |= has_sign ? SHORT_ATOM_SIGNED : 0;
+ atom |= len & SHORT_ATOM_LEN_MASK;
+
+ add_token_u8(&err, cmd, atom);
+}
+
+static void add_medium_atom_header(struct opal_dev *cmd, bool bytestring,
+ bool has_sign, int len)
+{
+ u8 header0;
+
+ header0 = MEDIUM_ATOM_ID;
+ header0 |= bytestring ? MEDIUM_ATOM_BYTESTRING : 0;
+ header0 |= has_sign ? MEDIUM_ATOM_SIGNED : 0;
+ header0 |= (len >> 8) & MEDIUM_ATOM_LEN_MASK;
+ cmd->cmd[cmd->pos++] = header0;
+ cmd->cmd[cmd->pos++] = len;
+}
+
+static void add_token_u64(int *err, struct opal_dev *cmd, u64 number)
+{
+
+ size_t len;
+ int msb;
+ u8 n;
+
+ if (!(number & ~TINY_ATOM_DATA_MASK)) {
+ add_token_u8(err, cmd, number);
+ return;
+ }
+
+ msb = fls(number);
+ len = DIV_ROUND_UP(msb, 4);
+
+ if (cmd->pos >= IO_BUFFER_LENGTH - len - 1) {
+ pr_debug("Error adding u64: end of buffer.\n");
+ *err = -ERANGE;
+ return;
+ }
+ add_short_atom_header(cmd, false, false, len);
+ while (len--) {
+ n = number >> (len * 8);
+ add_token_u8(err, cmd, n);
+ }
+}
+
+static void add_token_bytestring(int *err, struct opal_dev *cmd,
+ const u8 *bytestring, size_t len)
+{
+ size_t header_len = 1;
+ bool is_short_atom = true;
+
+ if (*err)
+ return;
+
+ if (len & ~SHORT_ATOM_LEN_MASK) {
+ header_len = 2;
+ is_short_atom = false;
+ }
+
+ if (len >= IO_BUFFER_LENGTH - cmd->pos - header_len) {
+ pr_debug("Error adding bytestring: end of buffer.\n");
+ *err = -ERANGE;
+ return;
+ }
+
+ if (is_short_atom)
+ add_short_atom_header(cmd, true, false, len);
+ else
+ add_medium_atom_header(cmd, true, false, len);
+
+ memcpy(&cmd->cmd[cmd->pos], bytestring, len);
+ cmd->pos += len;
+
+}
+
+static int build_locking_range(u8 *buffer, size_t length, u8 lr)
+{
+ if (length > OPAL_UID_LENGTH) {
+ pr_debug("Can't build locking range. Length OOB\n");
+ return -ERANGE;
+ }
+
+ memcpy(buffer, opaluid[OPAL_LOCKINGRANGE_GLOBAL], OPAL_UID_LENGTH);
+
+ if (lr == 0)
+ return 0;
+ buffer[5] = LOCKING_RANGE_NON_GLOBAL;
+ buffer[7] = lr;
+
+ return 0;
+}
+
+static int build_locking_user(u8 *buffer, size_t length, u8 lr)
+{
+ if (length > OPAL_UID_LENGTH) {
+ pr_debug("Can't build locking range user, Length OOB\n");
+ return -ERANGE;
+ }
+
+ memcpy(buffer, opaluid[OPAL_USER1_UID], OPAL_UID_LENGTH);
+
+ buffer[7] = lr + 1;
+
+ return 0;
+}
+
+static void set_comid(struct opal_dev *cmd, u16 comid)
+{
+ struct opal_header *hdr = (struct opal_header *)cmd->cmd;
+
+ hdr->cp.extendedComID[0] = comid >> 8;
+ hdr->cp.extendedComID[1] = comid;
+ hdr->cp.extendedComID[2] = 0;
+ hdr->cp.extendedComID[3] = 0;
+}
+
+static int cmd_finalize(struct opal_dev *cmd, u32 hsn, u32 tsn)
+{
+ struct opal_header *hdr;
+ int err = 0;
+
+ add_token_u8(&err, cmd, OPAL_ENDOFDATA);
+ add_token_u8(&err, cmd, OPAL_STARTLIST);
+ add_token_u8(&err, cmd, 0);
+ add_token_u8(&err, cmd, 0);
+ add_token_u8(&err, cmd, 0);
+ add_token_u8(&err, cmd, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error finalizing command.\n");
+ return -EFAULT;
+ }
+
+ hdr = (struct opal_header *) cmd->cmd;
+
+ hdr->pkt.tsn = cpu_to_be32(tsn);
+ hdr->pkt.hsn = cpu_to_be32(hsn);
+
+ hdr->subpkt.length = cpu_to_be32(cmd->pos - sizeof(*hdr));
+ while (cmd->pos % 4) {
+ if (cmd->pos >= IO_BUFFER_LENGTH) {
+ pr_debug("Error: Buffer overrun\n");
+ return -ERANGE;
+ }
+ cmd->cmd[cmd->pos++] = 0;
+ }
+ hdr->pkt.length = cpu_to_be32(cmd->pos - sizeof(hdr->cp) -
+ sizeof(hdr->pkt));
+ hdr->cp.length = cpu_to_be32(cmd->pos - sizeof(hdr->cp));
+
+ return 0;
+}
+
+static const struct opal_resp_tok *response_get_token(
+ const struct parsed_resp *resp,
+ int n)
+{
+ const struct opal_resp_tok *tok;
+
+ if (n >= resp->num) {
+ pr_debug("Token number doesn't exist: %d, resp: %d\n",
+ n, resp->num);
+ return ERR_PTR(-EINVAL);
+ }
+
+ tok = &resp->toks[n];
+ if (tok->len == 0) {
+ pr_debug("Token length must be non-zero\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ return tok;
+}
+
+static ssize_t response_parse_tiny(struct opal_resp_tok *tok,
+ const u8 *pos)
+{
+ tok->pos = pos;
+ tok->len = 1;
+ tok->width = OPAL_WIDTH_TINY;
+
+ if (pos[0] & TINY_ATOM_SIGNED) {
+ tok->type = OPAL_DTA_TOKENID_SINT;
+ } else {
+ tok->type = OPAL_DTA_TOKENID_UINT;
+ tok->stored.u = pos[0] & 0x3f;
+ }
+
+ return tok->len;
+}
+
+static ssize_t response_parse_short(struct opal_resp_tok *tok,
+ const u8 *pos)
+{
+ tok->pos = pos;
+ tok->len = (pos[0] & SHORT_ATOM_LEN_MASK) + 1;
+ tok->width = OPAL_WIDTH_SHORT;
+
+ if (pos[0] & SHORT_ATOM_BYTESTRING) {
+ tok->type = OPAL_DTA_TOKENID_BYTESTRING;
+ } else if (pos[0] & SHORT_ATOM_SIGNED) {
+ tok->type = OPAL_DTA_TOKENID_SINT;
+ } else {
+ u64 u_integer = 0;
+ ssize_t i, b = 0;
+
+ tok->type = OPAL_DTA_TOKENID_UINT;
+ if (tok->len > 9) {
+ pr_debug("uint64 with more than 8 bytes\n");
+ return -EINVAL;
+ }
+ for (i = tok->len - 1; i > 0; i--) {
+ u_integer |= ((u64)pos[i] << (8 * b));
+ b++;
+ }
+ tok->stored.u = u_integer;
+ }
+
+ return tok->len;
+}
+
+static ssize_t response_parse_medium(struct opal_resp_tok *tok,
+ const u8 *pos)
+{
+ tok->pos = pos;
+ tok->len = (((pos[0] & MEDIUM_ATOM_LEN_MASK) << 8) | pos[1]) + 2;
+ tok->width = OPAL_WIDTH_MEDIUM;
+
+ if (pos[0] & MEDIUM_ATOM_BYTESTRING)
+ tok->type = OPAL_DTA_TOKENID_BYTESTRING;
+ else if (pos[0] & MEDIUM_ATOM_SIGNED)
+ tok->type = OPAL_DTA_TOKENID_SINT;
+ else
+ tok->type = OPAL_DTA_TOKENID_UINT;
+
+ return tok->len;
+}
+
+static ssize_t response_parse_long(struct opal_resp_tok *tok,
+ const u8 *pos)
+{
+ tok->pos = pos;
+ tok->len = ((pos[1] << 16) | (pos[2] << 8) | pos[3]) + 4;
+ tok->width = OPAL_WIDTH_LONG;
+
+ if (pos[0] & LONG_ATOM_BYTESTRING)
+ tok->type = OPAL_DTA_TOKENID_BYTESTRING;
+ else if (pos[0] & LONG_ATOM_SIGNED)
+ tok->type = OPAL_DTA_TOKENID_SINT;
+ else
+ tok->type = OPAL_DTA_TOKENID_UINT;
+
+ return tok->len;
+}
+
+static ssize_t response_parse_token(struct opal_resp_tok *tok,
+ const u8 *pos)
+{
+ tok->pos = pos;
+ tok->len = 1;
+ tok->type = OPAL_DTA_TOKENID_TOKEN;
+ tok->width = OPAL_WIDTH_TOKEN;
+
+ return tok->len;
+}
+
+static int response_parse(const u8 *buf, size_t length,
+ struct parsed_resp *resp)
+{
+ const struct opal_header *hdr;
+ struct opal_resp_tok *iter;
+ int num_entries = 0;
+ int total;
+ ssize_t token_length;
+ const u8 *pos;
+ u32 clen, plen, slen;
+
+ if (!buf)
+ return -EFAULT;
+
+ if (!resp)
+ return -EFAULT;
+
+ hdr = (struct opal_header *)buf;
+ pos = buf;
+ pos += sizeof(*hdr);
+
+ clen = be32_to_cpu(hdr->cp.length);
+ plen = be32_to_cpu(hdr->pkt.length);
+ slen = be32_to_cpu(hdr->subpkt.length);
+ pr_debug("Response size: cp: %u, pkt: %u, subpkt: %u\n",
+ clen, plen, slen);
+
+ if (clen == 0 || plen == 0 || slen == 0 ||
+ slen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
+ pr_debug("Bad header length. cp: %u, pkt: %u, subpkt: %u\n",
+ clen, plen, slen);
+ print_buffer(pos, sizeof(*hdr));
+ return -EINVAL;
+ }
+
+ if (pos > buf + length)
+ return -EFAULT;
+
+ iter = resp->toks;
+ total = slen;
+ print_buffer(pos, total);
+ while (total > 0) {
+ if (pos[0] <= TINY_ATOM_BYTE) /* tiny atom */
+ token_length = response_parse_tiny(iter, pos);
+ else if (pos[0] <= SHORT_ATOM_BYTE) /* short atom */
+ token_length = response_parse_short(iter, pos);
+ else if (pos[0] <= MEDIUM_ATOM_BYTE) /* medium atom */
+ token_length = response_parse_medium(iter, pos);
+ else if (pos[0] <= LONG_ATOM_BYTE) /* long atom */
+ token_length = response_parse_long(iter, pos);
+ else /* TOKEN */
+ token_length = response_parse_token(iter, pos);
+
+ if (token_length < 0)
+ return token_length;
+
+ pos += token_length;
+ total -= token_length;
+ iter++;
+ num_entries++;
+ }
+
+ if (num_entries == 0) {
+ pr_debug("Couldn't parse response.\n");
+ return -EINVAL;
+ }
+ resp->num = num_entries;
+
+ return 0;
+}
+
+static size_t response_get_string(const struct parsed_resp *resp, int n,
+ const char **store)
+{
+ *store = NULL;
+ if (!resp) {
+ pr_debug("Response is NULL\n");
+ return 0;
+ }
+
+ if (n >= resp->num) {
+ pr_debug("Response has %d tokens. Can't access %d\n",
+ resp->num, n);
+ return 0;
+ }
+
+ if (resp->toks[n].type != OPAL_DTA_TOKENID_BYTESTRING) {
+ pr_debug("Token is not a byte string!\n");
+ return 0;
+ }
+
+ *store = resp->toks[n].pos + 1;
+ return resp->toks[n].len - 1;
+}
+
+static u64 response_get_u64(const struct parsed_resp *resp, int n)
+{
+ if (!resp) {
+ pr_debug("Response is NULL\n");
+ return 0;
+ }
+
+ if (n >= resp->num) {
+ pr_debug("Response has %d tokens. Can't access %d\n",
+ resp->num, n);
+ return 0;
+ }
+
+ if (resp->toks[n].type != OPAL_DTA_TOKENID_UINT) {
+ pr_debug("Token is not unsigned it: %d\n",
+ resp->toks[n].type);
+ return 0;
+ }
+
+ if (!(resp->toks[n].width == OPAL_WIDTH_TINY ||
+ resp->toks[n].width == OPAL_WIDTH_SHORT)) {
+ pr_debug("Atom is not short or tiny: %d\n",
+ resp->toks[n].width);
+ return 0;
+ }
+
+ return resp->toks[n].stored.u;
+}
+
+static bool response_token_matches(const struct opal_resp_tok *token, u8 match)
+{
+ if (IS_ERR(token) ||
+ token->type != OPAL_DTA_TOKENID_TOKEN ||
+ token->pos[0] != match)
+ return false;
+ return true;
+}
+
+static u8 response_status(const struct parsed_resp *resp)
+{
+ const struct opal_resp_tok *tok;
+
+ tok = response_get_token(resp, 0);
+ if (response_token_matches(tok, OPAL_ENDOFSESSION))
+ return 0;
+
+ if (resp->num < 5)
+ return DTAERROR_NO_METHOD_STATUS;
+
+ tok = response_get_token(resp, resp->num - 5);
+ if (!response_token_matches(tok, OPAL_STARTLIST))
+ return DTAERROR_NO_METHOD_STATUS;
+
+ tok = response_get_token(resp, resp->num - 1);
+ if (!response_token_matches(tok, OPAL_ENDLIST))
+ return DTAERROR_NO_METHOD_STATUS;
+
+ return response_get_u64(resp, resp->num - 4);
+}
+
+/* Parses and checks for errors */
+static int parse_and_check_status(struct opal_dev *dev)
+{
+ int error;
+
+ print_buffer(dev->cmd, dev->pos);
+
+ error = response_parse(dev->resp, IO_BUFFER_LENGTH, &dev->parsed);
+ if (error) {
+ pr_debug("Couldn't parse response.\n");
+ return error;
+ }
+
+ return response_status(&dev->parsed);
+}
+
+static void clear_opal_cmd(struct opal_dev *dev)
+{
+ dev->pos = sizeof(struct opal_header);
+ memset(dev->cmd, 0, IO_BUFFER_LENGTH);
+}
+
+static int start_opal_session_cont(struct opal_dev *dev)
+{
+ u32 hsn, tsn;
+ int error = 0;
+
+ error = parse_and_check_status(dev);
+ if (error)
+ return error;
+
+ hsn = response_get_u64(&dev->parsed, 4);
+ tsn = response_get_u64(&dev->parsed, 5);
+
+ if (hsn == 0 && tsn == 0) {
+ pr_debug("Couldn't authenticate session\n");
+ return -EPERM;
+ }
+
+ dev->hsn = hsn;
+ dev->tsn = tsn;
+ return 0;
+}
+
+static void add_suspend_info(struct opal_dev *dev,
+ struct opal_suspend_data *sus)
+{
+ struct opal_suspend_data *iter;
+
+ list_for_each_entry(iter, &dev->unlk_lst, node) {
+ if (iter->lr == sus->lr) {
+ list_del(&iter->node);
+ kfree(iter);
+ break;
+ }
+ }
+ list_add_tail(&sus->node, &dev->unlk_lst);
+}
+
+static int end_session_cont(struct opal_dev *dev)
+{
+ dev->hsn = 0;
+ dev->tsn = 0;
+ return parse_and_check_status(dev);
+}
+
+static int finalize_and_send(struct opal_dev *dev, cont_fn cont)
+{
+ int ret;
+
+ ret = cmd_finalize(dev, dev->hsn, dev->tsn);
+ if (ret) {
+ pr_debug("Error finalizing command buffer: %d\n", ret);
+ return ret;
+ }
+
+ print_buffer(dev->cmd, dev->pos);
+
+ return opal_send_recv(dev, cont);
+}
+
+static int gen_key(struct opal_dev *dev, void *data)
+{
+ u8 uid[OPAL_UID_LENGTH];
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ memcpy(uid, dev->prev_data, min(sizeof(uid), dev->prev_d_len));
+ kfree(dev->prev_data);
+ dev->prev_data = NULL;
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, uid, OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_GENKEY],
+ OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error building gen key command\n");
+ return err;
+
+ }
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int get_active_key_cont(struct opal_dev *dev)
+{
+ const char *activekey;
+ size_t keylen;
+ int error = 0;
+
+ error = parse_and_check_status(dev);
+ if (error)
+ return error;
+ keylen = response_get_string(&dev->parsed, 4, &activekey);
+ if (!activekey) {
+ pr_debug("%s: Couldn't extract the Activekey from the response\n",
+ __func__);
+ return OPAL_INVAL_PARAM;
+ }
+ dev->prev_data = kmemdup(activekey, keylen, GFP_KERNEL);
+
+ if (!dev->prev_data)
+ return -ENOMEM;
+
+ dev->prev_d_len = keylen;
+
+ return 0;
+}
+
+static int get_active_key(struct opal_dev *dev, void *data)
+{
+ u8 uid[OPAL_UID_LENGTH];
+ int err = 0;
+ u8 *lr = data;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ err = build_locking_range(uid, sizeof(uid), *lr);
+ if (err)
+ return err;
+
+ err = 0;
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, uid, OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_GET], OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 3); /* startCloumn */
+ add_token_u8(&err, dev, 10); /* ActiveKey */
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 4); /* endColumn */
+ add_token_u8(&err, dev, 10); /* ActiveKey */
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ if (err) {
+ pr_debug("Error building get active key command\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, get_active_key_cont);
+}
+
+static int generic_lr_enable_disable(struct opal_dev *dev,
+ u8 *uid, bool rle, bool wle,
+ bool rl, bool wl)
+{
+ int err = 0;
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, uid, OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_SET], OPAL_UID_LENGTH);
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_VALUES);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 5); /* ReadLockEnabled */
+ add_token_u8(&err, dev, rle);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 6); /* WriteLockEnabled */
+ add_token_u8(&err, dev, wle);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_READLOCKED);
+ add_token_u8(&err, dev, rl);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_WRITELOCKED);
+ add_token_u8(&err, dev, wl);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ return err;
+}
+
+static inline int enable_global_lr(struct opal_dev *dev, u8 *uid,
+ struct opal_user_lr_setup *setup)
+{
+ int err;
+
+ err = generic_lr_enable_disable(dev, uid, !!setup->RLE, !!setup->WLE,
+ 0, 0);
+ if (err)
+ pr_debug("Failed to create enable global lr command\n");
+ return err;
+}
+
+static int setup_locking_range(struct opal_dev *dev, void *data)
+{
+ u8 uid[OPAL_UID_LENGTH];
+ struct opal_user_lr_setup *setup = data;
+ u8 lr;
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ lr = setup->session.opal_key.lr;
+ err = build_locking_range(uid, sizeof(uid), lr);
+ if (err)
+ return err;
+
+ if (lr == 0)
+ err = enable_global_lr(dev, uid, setup);
+ else {
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, uid, OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_SET],
+ OPAL_UID_LENGTH);
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_VALUES);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 3); /* Ranges Start */
+ add_token_u64(&err, dev, setup->range_start);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 4); /* Ranges length */
+ add_token_u64(&err, dev, setup->range_length);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 5); /*ReadLockEnabled */
+ add_token_u64(&err, dev, !!setup->RLE);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 6); /*WriteLockEnabled*/
+ add_token_u64(&err, dev, !!setup->WLE);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ }
+ if (err) {
+ pr_debug("Error building Setup Locking range command.\n");
+ return err;
+
+ }
+
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int start_generic_opal_session(struct opal_dev *dev,
+ enum opal_uid auth,
+ enum opal_uid sp_type,
+ const char *key,
+ u8 key_len)
+{
+ u32 hsn;
+ int err = 0;
+
+ if (key == NULL && auth != OPAL_ANYBODY_UID)
+ return OPAL_INVAL_PARAM;
+
+ clear_opal_cmd(dev);
+
+ set_comid(dev, dev->comid);
+ hsn = GENERIC_HOST_SESSION_NUM;
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, opaluid[OPAL_SMUID_UID],
+ OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_STARTSESSION],
+ OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u64(&err, dev, hsn);
+ add_token_bytestring(&err, dev, opaluid[sp_type], OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, 1);
+
+ switch (auth) {
+ case OPAL_ANYBODY_UID:
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ break;
+ case OPAL_ADMIN1_UID:
+ case OPAL_SID_UID:
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 0); /* HostChallenge */
+ add_token_bytestring(&err, dev, key, key_len);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 3); /* HostSignAuth */
+ add_token_bytestring(&err, dev, opaluid[auth],
+ OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ break;
+ default:
+ pr_debug("Cannot start Admin SP session with auth %d\n", auth);
+ return OPAL_INVAL_PARAM;
+ }
+
+ if (err) {
+ pr_debug("Error building start adminsp session command.\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, start_opal_session_cont);
+}
+
+static int start_anybodyASP_opal_session(struct opal_dev *dev, void *data)
+{
+ return start_generic_opal_session(dev, OPAL_ANYBODY_UID,
+ OPAL_ADMINSP_UID, NULL, 0);
+}
+
+static int start_SIDASP_opal_session(struct opal_dev *dev, void *data)
+{
+ int ret;
+ const u8 *key = dev->prev_data;
+
+ if (!key) {
+ const struct opal_key *okey = data;
+ ret = start_generic_opal_session(dev, OPAL_SID_UID,
+ OPAL_ADMINSP_UID,
+ okey->key,
+ okey->key_len);
+ } else {
+ ret = start_generic_opal_session(dev, OPAL_SID_UID,
+ OPAL_ADMINSP_UID,
+ key, dev->prev_d_len);
+ kfree(key);
+ dev->prev_data = NULL;
+ }
+ return ret;
+}
+
+static int start_admin1LSP_opal_session(struct opal_dev *dev, void *data)
+{
+ struct opal_key *key = data;
+ return start_generic_opal_session(dev, OPAL_ADMIN1_UID,
+ OPAL_LOCKINGSP_UID,
+ key->key, key->key_len);
+}
+
+static int start_auth_opal_session(struct opal_dev *dev, void *data)
+{
+ struct opal_session_info *session = data;
+ u8 lk_ul_user[OPAL_UID_LENGTH];
+ size_t keylen = session->opal_key.key_len;
+ int err = 0;
+
+ u8 *key = session->opal_key.key;
+ u32 hsn = GENERIC_HOST_SESSION_NUM;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ if (session->sum) {
+ err = build_locking_user(lk_ul_user, sizeof(lk_ul_user),
+ session->opal_key.lr);
+ if (err)
+ return err;
+
+ } else if (session->who != OPAL_ADMIN1 && !session->sum) {
+ err = build_locking_user(lk_ul_user, sizeof(lk_ul_user),
+ session->who - 1);
+ if (err)
+ return err;
+ } else
+ memcpy(lk_ul_user, opaluid[OPAL_ADMIN1_UID], OPAL_UID_LENGTH);
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, opaluid[OPAL_SMUID_UID],
+ OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_STARTSESSION],
+ OPAL_UID_LENGTH);
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u64(&err, dev, hsn);
+ add_token_bytestring(&err, dev, opaluid[OPAL_LOCKINGSP_UID],
+ OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, 1);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 0);
+ add_token_bytestring(&err, dev, key, keylen);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 3);
+ add_token_bytestring(&err, dev, lk_ul_user, OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error building STARTSESSION command.\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, start_opal_session_cont);
+}
+
+static int revert_tper(struct opal_dev *dev, void *data)
+{
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, opaluid[OPAL_ADMINSP_UID],
+ OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_REVERT],
+ OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ if (err) {
+ pr_debug("Error building REVERT TPER command.\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int internal_activate_user(struct opal_dev *dev, void *data)
+{
+ struct opal_session_info *session = data;
+ u8 uid[OPAL_UID_LENGTH];
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ memcpy(uid, opaluid[OPAL_USER1_UID], OPAL_UID_LENGTH);
+ uid[7] = session->who;
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, uid, OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_SET], OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_VALUES);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 5); /* Enabled */
+ add_token_u8(&err, dev, OPAL_TRUE);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error building Activate UserN command.\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int erase_locking_range(struct opal_dev *dev, void *data)
+{
+ struct opal_session_info *session = data;
+ u8 uid[OPAL_UID_LENGTH];
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ if (build_locking_range(uid, sizeof(uid), session->opal_key.lr) < 0)
+ return -ERANGE;
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, uid, OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_ERASE],
+ OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error building Erase Locking Range Command.\n");
+ return err;
+ }
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int set_mbr_done(struct opal_dev *dev, void *data)
+{
+ u8 *mbr_done_tf = data;
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, opaluid[OPAL_MBRCONTROL],
+ OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_SET], OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_VALUES);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 2); /* Done */
+ add_token_u8(&err, dev, *mbr_done_tf); /* Done T or F */
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error Building set MBR Done command\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int set_mbr_enable_disable(struct opal_dev *dev, void *data)
+{
+ u8 *mbr_en_dis = data;
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, opaluid[OPAL_MBRCONTROL],
+ OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_SET], OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_VALUES);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 1);
+ add_token_u8(&err, dev, *mbr_en_dis);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error Building set MBR done command\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int generic_pw_cmd(u8 *key, size_t key_len, u8 *cpin_uid,
+ struct opal_dev *dev)
+{
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, cpin_uid, OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_SET],
+ OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_VALUES);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 3); /* PIN */
+ add_token_bytestring(&err, dev, key, key_len);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ return err;
+}
+
+static int set_new_pw(struct opal_dev *dev, void *data)
+{
+ u8 cpin_uid[OPAL_UID_LENGTH];
+ struct opal_session_info *usr = data;
+
+ memcpy(cpin_uid, opaluid[OPAL_C_PIN_ADMIN1], OPAL_UID_LENGTH);
+
+ if (usr->who != OPAL_ADMIN1) {
+ cpin_uid[5] = 0x03;
+ if (usr->sum)
+ cpin_uid[7] = usr->opal_key.lr + 1;
+ else
+ cpin_uid[7] = usr->who;
+ }
+
+ if (generic_pw_cmd(usr->opal_key.key, usr->opal_key.key_len,
+ cpin_uid, dev)) {
+ pr_debug("Error building set password command.\n");
+ return -ERANGE;
+ }
+
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int set_sid_cpin_pin(struct opal_dev *dev, void *data)
+{
+ u8 cpin_uid[OPAL_UID_LENGTH];
+ struct opal_key *key = data;
+
+ memcpy(cpin_uid, opaluid[OPAL_C_PIN_SID], OPAL_UID_LENGTH);
+
+ if (generic_pw_cmd(key->key, key->key_len, cpin_uid, dev)) {
+ pr_debug("Error building Set SID cpin\n");
+ return -ERANGE;
+ }
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int add_user_to_lr(struct opal_dev *dev, void *data)
+{
+ u8 lr_buffer[OPAL_UID_LENGTH];
+ u8 user_uid[OPAL_UID_LENGTH];
+ struct opal_lock_unlock *lkul = data;
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ memcpy(lr_buffer, opaluid[OPAL_LOCKINGRANGE_ACE_RDLOCKED],
+ OPAL_UID_LENGTH);
+
+ if (lkul->l_state == OPAL_RW)
+ memcpy(lr_buffer, opaluid[OPAL_LOCKINGRANGE_ACE_WRLOCKED],
+ OPAL_UID_LENGTH);
+
+ lr_buffer[7] = lkul->session.opal_key.lr;
+
+ memcpy(user_uid, opaluid[OPAL_USER1_UID], OPAL_UID_LENGTH);
+
+ user_uid[7] = lkul->session.who;
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, lr_buffer, OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_SET],
+ OPAL_UID_LENGTH);
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_VALUES);
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 3);
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_bytestring(&err, dev,
+ opaluid[OPAL_HALF_UID_AUTHORITY_OBJ_REF],
+ OPAL_UID_LENGTH/2);
+ add_token_bytestring(&err, dev, user_uid, OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_bytestring(&err, dev,
+ opaluid[OPAL_HALF_UID_AUTHORITY_OBJ_REF],
+ OPAL_UID_LENGTH/2);
+ add_token_bytestring(&err, dev, user_uid, OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_bytestring(&err, dev, opaluid[OPAL_HALF_UID_BOOLEAN_ACE],
+ OPAL_UID_LENGTH/2);
+ add_token_u8(&err, dev, 1);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error building add user to locking range command.\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int lock_unlock_locking_range(struct opal_dev *dev, void *data)
+{
+ u8 lr_buffer[OPAL_UID_LENGTH];
+ struct opal_lock_unlock *lkul = data;
+ u8 read_locked = 1, write_locked = 1;
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ if (build_locking_range(lr_buffer, sizeof(lr_buffer),
+ lkul->session.opal_key.lr) < 0)
+ return -ERANGE;
+
+ switch (lkul->l_state) {
+ case OPAL_RO:
+ read_locked = 0;
+ write_locked = 1;
+ break;
+ case OPAL_RW:
+ read_locked = 0;
+ write_locked = 0;
+ break;
+ case OPAL_LK:
+ /* vars are initalized to locked */
+ break;
+ default:
+ pr_debug("Tried to set an invalid locking state... returning to uland\n");
+ return OPAL_INVAL_PARAM;
+ }
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, lr_buffer, OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_SET], OPAL_UID_LENGTH);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_VALUES);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_READLOCKED);
+ add_token_u8(&err, dev, read_locked);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_WRITELOCKED);
+ add_token_u8(&err, dev, write_locked);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error building SET command.\n");
+ return err;
+ }
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+
+static int lock_unlock_locking_range_sum(struct opal_dev *dev, void *data)
+{
+ u8 lr_buffer[OPAL_UID_LENGTH];
+ u8 read_locked = 1, write_locked = 1;
+ struct opal_lock_unlock *lkul = data;
+ int ret;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ if (build_locking_range(lr_buffer, sizeof(lr_buffer),
+ lkul->session.opal_key.lr) < 0)
+ return -ERANGE;
+
+ switch (lkul->l_state) {
+ case OPAL_RO:
+ read_locked = 0;
+ write_locked = 1;
+ break;
+ case OPAL_RW:
+ read_locked = 0;
+ write_locked = 0;
+ break;
+ case OPAL_LK:
+ /* vars are initalized to locked */
+ break;
+ default:
+ pr_debug("Tried to set an invalid locking state.\n");
+ return OPAL_INVAL_PARAM;
+ }
+ ret = generic_lr_enable_disable(dev, lr_buffer, 1, 1,
+ read_locked, write_locked);
+
+ if (ret < 0) {
+ pr_debug("Error building SET command.\n");
+ return ret;
+ }
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int activate_lsp(struct opal_dev *dev, void *data)
+{
+ struct opal_lr_act *opal_act = data;
+ u8 user_lr[OPAL_UID_LENGTH];
+ u8 uint_3 = 0x83;
+ int err = 0, i;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, opaluid[OPAL_LOCKINGSP_UID],
+ OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_ACTIVATE],
+ OPAL_UID_LENGTH);
+
+
+ if (opal_act->sum) {
+ err = build_locking_range(user_lr, sizeof(user_lr),
+ opal_act->lr[0]);
+ if (err)
+ return err;
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, uint_3);
+ add_token_u8(&err, dev, 6);
+ add_token_u8(&err, dev, 0);
+ add_token_u8(&err, dev, 0);
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_bytestring(&err, dev, user_lr, OPAL_UID_LENGTH);
+ for (i = 1; i < opal_act->num_lrs; i++) {
+ user_lr[7] = opal_act->lr[i];
+ add_token_bytestring(&err, dev, user_lr, OPAL_UID_LENGTH);
+ }
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ } else {
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ }
+
+ if (err) {
+ pr_debug("Error building Activate LockingSP command.\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, parse_and_check_status);
+}
+
+static int get_lsp_lifecycle_cont(struct opal_dev *dev)
+{
+ u8 lc_status;
+ int error = 0;
+
+ error = parse_and_check_status(dev);
+ if (error)
+ return error;
+
+ lc_status = response_get_u64(&dev->parsed, 4);
+ /* 0x08 is Manufacured Inactive */
+ /* 0x09 is Manufactured */
+ if (lc_status != OPAL_MANUFACTURED_INACTIVE) {
+ pr_debug("Couldn't determine the status of the Lifecycle state\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+/* Determine if we're in the Manufactured Inactive or Active state */
+static int get_lsp_lifecycle(struct opal_dev *dev, void *data)
+{
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, opaluid[OPAL_LOCKINGSP_UID],
+ OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_GET], OPAL_UID_LENGTH);
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 3); /* Start Column */
+ add_token_u8(&err, dev, 6); /* Lifecycle Column */
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 4); /* End Column */
+ add_token_u8(&err, dev, 6); /* Lifecycle Column */
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error Building GET Lifecycle Status command\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, get_lsp_lifecycle_cont);
+}
+
+static int get_msid_cpin_pin_cont(struct opal_dev *dev)
+{
+ const char *msid_pin;
+ size_t strlen;
+ int error = 0;
+
+ error = parse_and_check_status(dev);
+ if (error)
+ return error;
+
+ strlen = response_get_string(&dev->parsed, 4, &msid_pin);
+ if (!msid_pin) {
+ pr_debug("%s: Couldn't extract PIN from response\n", __func__);
+ return OPAL_INVAL_PARAM;
+ }
+
+ dev->prev_data = kmemdup(msid_pin, strlen, GFP_KERNEL);
+ if (!dev->prev_data)
+ return -ENOMEM;
+
+ dev->prev_d_len = strlen;
+
+ return 0;
+}
+
+static int get_msid_cpin_pin(struct opal_dev *dev, void *data)
+{
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+
+ add_token_u8(&err, dev, OPAL_CALL);
+ add_token_bytestring(&err, dev, opaluid[OPAL_C_PIN_MSID],
+ OPAL_UID_LENGTH);
+ add_token_bytestring(&err, dev, opalmethod[OPAL_GET], OPAL_UID_LENGTH);
+
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+ add_token_u8(&err, dev, OPAL_STARTLIST);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 3); /* Start Column */
+ add_token_u8(&err, dev, 3); /* PIN */
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, 4); /* End Column */
+ add_token_u8(&err, dev, 3); /* Lifecycle Column */
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+ add_token_u8(&err, dev, OPAL_ENDLIST);
+
+ if (err) {
+ pr_debug("Error building Get MSID CPIN PIN command.\n");
+ return err;
+ }
+
+ return finalize_and_send(dev, get_msid_cpin_pin_cont);
+}
+
+static int end_opal_session(struct opal_dev *dev, void *data)
+{
+ int err = 0;
+
+ clear_opal_cmd(dev);
+ set_comid(dev, dev->comid);
+ add_token_u8(&err, dev, OPAL_ENDOFSESSION);
+
+ if (err < 0)
+ return err;
+ return finalize_and_send(dev, end_session_cont);
+}
+
+static int end_opal_session_error(struct opal_dev *dev)
+{
+ const struct opal_step error_end_session[] = {
+ { end_opal_session, },
+ { NULL, }
+ };
+ dev->steps = error_end_session;
+ return next(dev);
+}
+
+static inline void setup_opal_dev(struct opal_dev *dev,
+ const struct opal_step *steps)
+{
+ dev->steps = steps;
+ dev->tsn = 0;
+ dev->hsn = 0;
+ dev->prev_data = NULL;
+}
+
+static int check_opal_support(struct opal_dev *dev)
+{
+ const struct opal_step steps[] = {
+ { opal_discovery0, },
+ { NULL, }
+ };
+ int ret;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, steps);
+ ret = next(dev);
+ dev->supported = !ret;
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static void clean_opal_dev(struct opal_dev *dev)
+{
+
+ struct opal_suspend_data *suspend, *next;
+
+ mutex_lock(&dev->dev_lock);
+ list_for_each_entry_safe(suspend, next, &dev->unlk_lst, node) {
+ list_del(&suspend->node);
+ kfree(suspend);
+ }
+ mutex_unlock(&dev->dev_lock);
+}
+
+void free_opal_dev(struct opal_dev *dev)
+{
+ if (!dev)
+ return;
+ clean_opal_dev(dev);
+ kfree(dev);
+}
+EXPORT_SYMBOL(free_opal_dev);
+
+struct opal_dev *init_opal_dev(void *data, sec_send_recv *send_recv)
+{
+ struct opal_dev *dev;
+
+ dev = kmalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return NULL;
+
+ INIT_LIST_HEAD(&dev->unlk_lst);
+ mutex_init(&dev->dev_lock);
+ dev->data = data;
+ dev->send_recv = send_recv;
+ if (check_opal_support(dev) != 0) {
+ pr_debug("Opal is not supported on this device\n");
+ kfree(dev);
+ return NULL;
+ }
+ return dev;
+}
+EXPORT_SYMBOL(init_opal_dev);
+
+static int opal_secure_erase_locking_range(struct opal_dev *dev,
+ struct opal_session_info *opal_session)
+{
+ const struct opal_step erase_steps[] = {
+ { opal_discovery0, },
+ { start_auth_opal_session, opal_session },
+ { get_active_key, &opal_session->opal_key.lr },
+ { gen_key, },
+ { end_opal_session, },
+ { NULL, }
+ };
+ int ret;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, erase_steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_erase_locking_range(struct opal_dev *dev,
+ struct opal_session_info *opal_session)
+{
+ const struct opal_step erase_steps[] = {
+ { opal_discovery0, },
+ { start_auth_opal_session, opal_session },
+ { erase_locking_range, opal_session },
+ { end_opal_session, },
+ { NULL, }
+ };
+ int ret;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, erase_steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_enable_disable_shadow_mbr(struct opal_dev *dev,
+ struct opal_mbr_data *opal_mbr)
+{
+ u8 enable_disable = opal_mbr->enable_disable == OPAL_MBR_ENABLE ?
+ OPAL_TRUE : OPAL_FALSE;
+
+ const struct opal_step mbr_steps[] = {
+ { opal_discovery0, },
+ { start_admin1LSP_opal_session, &opal_mbr->key },
+ { set_mbr_done, &enable_disable },
+ { end_opal_session, },
+ { start_admin1LSP_opal_session, &opal_mbr->key },
+ { set_mbr_enable_disable, &enable_disable },
+ { end_opal_session, },
+ { NULL, }
+ };
+ int ret;
+
+ if (opal_mbr->enable_disable != OPAL_MBR_ENABLE &&
+ opal_mbr->enable_disable != OPAL_MBR_DISABLE)
+ return -EINVAL;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, mbr_steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_save(struct opal_dev *dev, struct opal_lock_unlock *lk_unlk)
+{
+ struct opal_suspend_data *suspend;
+
+ suspend = kzalloc(sizeof(*suspend), GFP_KERNEL);
+ if (!suspend)
+ return -ENOMEM;
+
+ suspend->unlk = *lk_unlk;
+ suspend->lr = lk_unlk->session.opal_key.lr;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, NULL);
+ add_suspend_info(dev, suspend);
+ mutex_unlock(&dev->dev_lock);
+ return 0;
+}
+
+static int opal_add_user_to_lr(struct opal_dev *dev,
+ struct opal_lock_unlock *lk_unlk)
+{
+ const struct opal_step steps[] = {
+ { opal_discovery0, },
+ { start_admin1LSP_opal_session, &lk_unlk->session.opal_key },
+ { add_user_to_lr, lk_unlk },
+ { end_opal_session, },
+ { NULL, }
+ };
+ int ret;
+
+ if (lk_unlk->l_state != OPAL_RO &&
+ lk_unlk->l_state != OPAL_RW) {
+ pr_debug("Locking state was not RO or RW\n");
+ return -EINVAL;
+ }
+ if (lk_unlk->session.who < OPAL_USER1 ||
+ lk_unlk->session.who > OPAL_USER9) {
+ pr_debug("Authority was not within the range of users: %d\n",
+ lk_unlk->session.who);
+ return -EINVAL;
+ }
+ if (lk_unlk->session.sum) {
+ pr_debug("%s not supported in sum. Use setup locking range\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_reverttper(struct opal_dev *dev, struct opal_key *opal)
+{
+ const struct opal_step revert_steps[] = {
+ { opal_discovery0, },
+ { start_SIDASP_opal_session, opal },
+ { revert_tper, }, /* controller will terminate session */
+ { NULL, }
+ };
+ int ret;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, revert_steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+
+ /*
+ * If we successfully reverted lets clean
+ * any saved locking ranges.
+ */
+ if (!ret)
+ clean_opal_dev(dev);
+
+ return ret;
+}
+
+static int __opal_lock_unlock(struct opal_dev *dev,
+ struct opal_lock_unlock *lk_unlk)
+{
+ const struct opal_step unlock_steps[] = {
+ { opal_discovery0, },
+ { start_auth_opal_session, &lk_unlk->session },
+ { lock_unlock_locking_range, lk_unlk },
+ { end_opal_session, },
+ { NULL, }
+ };
+ const struct opal_step unlock_sum_steps[] = {
+ { opal_discovery0, },
+ { start_auth_opal_session, &lk_unlk->session },
+ { lock_unlock_locking_range_sum, lk_unlk },
+ { end_opal_session, },
+ { NULL, }
+ };
+
+ dev->steps = lk_unlk->session.sum ? unlock_sum_steps : unlock_steps;
+ return next(dev);
+}
+
+static int __opal_set_mbr_done(struct opal_dev *dev, struct opal_key *key)
+{
+ u8 mbr_done_tf = OPAL_TRUE;
+ const struct opal_step mbrdone_step [] = {
+ { opal_discovery0, },
+ { start_admin1LSP_opal_session, key },
+ { set_mbr_done, &mbr_done_tf },
+ { end_opal_session, },
+ { NULL, }
+ };
+
+ dev->steps = mbrdone_step;
+ return next(dev);
+}
+
+static int opal_lock_unlock(struct opal_dev *dev,
+ struct opal_lock_unlock *lk_unlk)
+{
+ int ret;
+
+ if (lk_unlk->session.who < OPAL_ADMIN1 ||
+ lk_unlk->session.who > OPAL_USER9)
+ return -EINVAL;
+
+ mutex_lock(&dev->dev_lock);
+ ret = __opal_lock_unlock(dev, lk_unlk);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_take_ownership(struct opal_dev *dev, struct opal_key *opal)
+{
+ const struct opal_step owner_steps[] = {
+ { opal_discovery0, },
+ { start_anybodyASP_opal_session, },
+ { get_msid_cpin_pin, },
+ { end_opal_session, },
+ { start_SIDASP_opal_session, opal },
+ { set_sid_cpin_pin, opal },
+ { end_opal_session, },
+ { NULL, }
+ };
+ int ret;
+
+ if (!dev)
+ return -ENODEV;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, owner_steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_activate_lsp(struct opal_dev *dev, struct opal_lr_act *opal_lr_act)
+{
+ const struct opal_step active_steps[] = {
+ { opal_discovery0, },
+ { start_SIDASP_opal_session, &opal_lr_act->key },
+ { get_lsp_lifecycle, },
+ { activate_lsp, opal_lr_act },
+ { end_opal_session, },
+ { NULL, }
+ };
+ int ret;
+
+ if (!opal_lr_act->num_lrs || opal_lr_act->num_lrs > OPAL_MAX_LRS)
+ return -EINVAL;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, active_steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_setup_locking_range(struct opal_dev *dev,
+ struct opal_user_lr_setup *opal_lrs)
+{
+ const struct opal_step lr_steps[] = {
+ { opal_discovery0, },
+ { start_auth_opal_session, &opal_lrs->session },
+ { setup_locking_range, opal_lrs },
+ { end_opal_session, },
+ { NULL, }
+ };
+ int ret;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, lr_steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_set_new_pw(struct opal_dev *dev, struct opal_new_pw *opal_pw)
+{
+ const struct opal_step pw_steps[] = {
+ { opal_discovery0, },
+ { start_auth_opal_session, &opal_pw->session },
+ { set_new_pw, &opal_pw->new_user_pw },
+ { end_opal_session, },
+ { NULL }
+ };
+ int ret;
+
+ if (opal_pw->session.who < OPAL_ADMIN1 ||
+ opal_pw->session.who > OPAL_USER9 ||
+ opal_pw->new_user_pw.who < OPAL_ADMIN1 ||
+ opal_pw->new_user_pw.who > OPAL_USER9)
+ return -EINVAL;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, pw_steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_activate_user(struct opal_dev *dev,
+ struct opal_session_info *opal_session)
+{
+ const struct opal_step act_steps[] = {
+ { opal_discovery0, },
+ { start_admin1LSP_opal_session, &opal_session->opal_key },
+ { internal_activate_user, opal_session },
+ { end_opal_session, },
+ { NULL, }
+ };
+ int ret;
+
+ /* We can't activate Admin1 it's active as manufactured */
+ if (opal_session->who < OPAL_USER1 ||
+ opal_session->who > OPAL_USER9) {
+ pr_debug("Who was not a valid user: %d\n", opal_session->who);
+ return -EINVAL;
+ }
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, act_steps);
+ ret = next(dev);
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+bool opal_unlock_from_suspend(struct opal_dev *dev)
+{
+ struct opal_suspend_data *suspend;
+ bool was_failure = false;
+ int ret = 0;
+
+ if (!dev)
+ return false;
+ if (!dev->supported)
+ return false;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev, NULL);
+
+ list_for_each_entry(suspend, &dev->unlk_lst, node) {
+ dev->tsn = 0;
+ dev->hsn = 0;
+
+ ret = __opal_lock_unlock(dev, &suspend->unlk);
+ if (ret) {
+ pr_debug("Failed to unlock LR %hhu with sum %d\n",
+ suspend->unlk.session.opal_key.lr,
+ suspend->unlk.session.sum);
+ was_failure = true;
+ }
+ if (dev->mbr_enabled) {
+ ret = __opal_set_mbr_done(dev, &suspend->unlk.session.opal_key);
+ if (ret)
+ pr_debug("Failed to set MBR Done in S3 resume\n");
+ }
+ }
+ mutex_unlock(&dev->dev_lock);
+ return was_failure;
+}
+EXPORT_SYMBOL(opal_unlock_from_suspend);
+
+int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
+{
+ void *p;
+ int ret = -ENOTTY;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ if (!dev)
+ return -ENOTSUPP;
+ if (!dev->supported)
+ return -ENOTSUPP;
+
+ p = memdup_user(arg, _IOC_SIZE(cmd));
+ if (IS_ERR(p))
+ return PTR_ERR(p);
+
+ switch (cmd) {
+ case IOC_OPAL_SAVE:
+ ret = opal_save(dev, p);
+ break;
+ case IOC_OPAL_LOCK_UNLOCK:
+ ret = opal_lock_unlock(dev, p);
+ break;
+ case IOC_OPAL_TAKE_OWNERSHIP:
+ ret = opal_take_ownership(dev, p);
+ break;
+ case IOC_OPAL_ACTIVATE_LSP:
+ ret = opal_activate_lsp(dev, p);
+ break;
+ case IOC_OPAL_SET_PW:
+ ret = opal_set_new_pw(dev, p);
+ break;
+ case IOC_OPAL_ACTIVATE_USR:
+ ret = opal_activate_user(dev, p);
+ break;
+ case IOC_OPAL_REVERT_TPR:
+ ret = opal_reverttper(dev, p);
+ break;
+ case IOC_OPAL_LR_SETUP:
+ ret = opal_setup_locking_range(dev, p);
+ break;
+ case IOC_OPAL_ADD_USR_TO_LR:
+ ret = opal_add_user_to_lr(dev, p);
+ break;
+ case IOC_OPAL_ENABLE_DISABLE_MBR:
+ ret = opal_enable_disable_shadow_mbr(dev, p);
+ break;
+ case IOC_OPAL_ERASE_LR:
+ ret = opal_erase_locking_range(dev, p);
+ break;
+ case IOC_OPAL_SECURE_ERASE_LR:
+ ret = opal_secure_erase_locking_range(dev, p);
+ break;
+ default:
+ break;
+ }
+
+ kfree(p);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(sed_ioctl);
diff --git a/src/kernel/linux/v4.14/block/t10-pi.c b/src/kernel/linux/v4.14/block/t10-pi.c
new file mode 100644
index 0000000..a98db38
--- /dev/null
+++ b/src/kernel/linux/v4.14/block/t10-pi.c
@@ -0,0 +1,186 @@
+/*
+ * t10_pi.c - Functions for generating and verifying T10 Protection
+ * Information.
+ *
+ * Copyright (C) 2007, 2008, 2014 Oracle Corporation
+ * Written by: Martin K. Petersen <martin.petersen@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ */
+
+#include <linux/t10-pi.h>
+#include <linux/blkdev.h>
+#include <linux/crc-t10dif.h>
+#include <net/checksum.h>
+
+typedef __be16 (csum_fn) (void *, unsigned int);
+
+static __be16 t10_pi_crc_fn(void *data, unsigned int len)
+{
+ return cpu_to_be16(crc_t10dif(data, len));
+}
+
+static __be16 t10_pi_ip_fn(void *data, unsigned int len)
+{
+ return (__force __be16)ip_compute_csum(data, len);
+}
+
+/*
+ * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
+ * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
+ * tag.
+ */
+static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
+ csum_fn *fn, unsigned int type)
+{
+ unsigned int i;
+
+ for (i = 0 ; i < iter->data_size ; i += iter->interval) {
+ struct t10_pi_tuple *pi = iter->prot_buf;
+
+ pi->guard_tag = fn(iter->data_buf, iter->interval);
+ pi->app_tag = 0;
+
+ if (type == 1)
+ pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
+ else
+ pi->ref_tag = 0;
+
+ iter->data_buf += iter->interval;
+ iter->prot_buf += sizeof(struct t10_pi_tuple);
+ iter->seed++;
+ }
+
+ return BLK_STS_OK;
+}
+
+static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
+ csum_fn *fn, unsigned int type)
+{
+ unsigned int i;
+
+ for (i = 0 ; i < iter->data_size ; i += iter->interval) {
+ struct t10_pi_tuple *pi = iter->prot_buf;
+ __be16 csum;
+
+ switch (type) {
+ case 1:
+ case 2:
+ if (pi->app_tag == T10_PI_APP_ESCAPE)
+ goto next;
+
+ if (be32_to_cpu(pi->ref_tag) !=
+ lower_32_bits(iter->seed)) {
+ pr_err("%s: ref tag error at location %llu " \
+ "(rcvd %u)\n", iter->disk_name,
+ (unsigned long long)
+ iter->seed, be32_to_cpu(pi->ref_tag));
+ return BLK_STS_PROTECTION;
+ }
+ break;
+ case 3:
+ if (pi->app_tag == T10_PI_APP_ESCAPE &&
+ pi->ref_tag == T10_PI_REF_ESCAPE)
+ goto next;
+ break;
+ }
+
+ csum = fn(iter->data_buf, iter->interval);
+
+ if (pi->guard_tag != csum) {
+ pr_err("%s: guard tag error at sector %llu " \
+ "(rcvd %04x, want %04x)\n", iter->disk_name,
+ (unsigned long long)iter->seed,
+ be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
+ return BLK_STS_PROTECTION;
+ }
+
+next:
+ iter->data_buf += iter->interval;
+ iter->prot_buf += sizeof(struct t10_pi_tuple);
+ iter->seed++;
+ }
+
+ return BLK_STS_OK;
+}
+
+static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
+{
+ return t10_pi_generate(iter, t10_pi_crc_fn, 1);
+}
+
+static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
+{
+ return t10_pi_generate(iter, t10_pi_ip_fn, 1);
+}
+
+static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
+{
+ return t10_pi_verify(iter, t10_pi_crc_fn, 1);
+}
+
+static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
+{
+ return t10_pi_verify(iter, t10_pi_ip_fn, 1);
+}
+
+static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
+{
+ return t10_pi_generate(iter, t10_pi_crc_fn, 3);
+}
+
+static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
+{
+ return t10_pi_generate(iter, t10_pi_ip_fn, 3);
+}
+
+static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
+{
+ return t10_pi_verify(iter, t10_pi_crc_fn, 3);
+}
+
+static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
+{
+ return t10_pi_verify(iter, t10_pi_ip_fn, 3);
+}
+
+const struct blk_integrity_profile t10_pi_type1_crc = {
+ .name = "T10-DIF-TYPE1-CRC",
+ .generate_fn = t10_pi_type1_generate_crc,
+ .verify_fn = t10_pi_type1_verify_crc,
+};
+EXPORT_SYMBOL(t10_pi_type1_crc);
+
+const struct blk_integrity_profile t10_pi_type1_ip = {
+ .name = "T10-DIF-TYPE1-IP",
+ .generate_fn = t10_pi_type1_generate_ip,
+ .verify_fn = t10_pi_type1_verify_ip,
+};
+EXPORT_SYMBOL(t10_pi_type1_ip);
+
+const struct blk_integrity_profile t10_pi_type3_crc = {
+ .name = "T10-DIF-TYPE3-CRC",
+ .generate_fn = t10_pi_type3_generate_crc,
+ .verify_fn = t10_pi_type3_verify_crc,
+};
+EXPORT_SYMBOL(t10_pi_type3_crc);
+
+const struct blk_integrity_profile t10_pi_type3_ip = {
+ .name = "T10-DIF-TYPE3-IP",
+ .generate_fn = t10_pi_type3_generate_ip,
+ .verify_fn = t10_pi_type3_verify_ip,
+};
+EXPORT_SYMBOL(t10_pi_type3_ip);