[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/drivers/md/raid10.c b/ap/os/linux/linux-3.4.x/drivers/md/raid10.c
new file mode 100644
index 0000000..149426c
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/md/raid10.c
@@ -0,0 +1,3613 @@
+/*
+ * raid10.c : Multiple Devices driver for Linux
+ *
+ * Copyright (C) 2000-2004 Neil Brown
+ *
+ * RAID-10 support for md.
+ *
+ * Base on code in raid1.c. See raid1.c for further copyright information.
+ *
+ *
+ * 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, or (at your option)
+ * any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * (for example /usr/src/linux/COPYING); if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/blkdev.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/ratelimit.h>
+#include "md.h"
+#include "raid10.h"
+#include "raid0.h"
+#include "bitmap.h"
+
+/*
+ * RAID10 provides a combination of RAID0 and RAID1 functionality.
+ * The layout of data is defined by
+ * chunk_size
+ * raid_disks
+ * near_copies (stored in low byte of layout)
+ * far_copies (stored in second byte of layout)
+ * far_offset (stored in bit 16 of layout )
+ *
+ * The data to be stored is divided into chunks using chunksize.
+ * Each device is divided into far_copies sections.
+ * In each section, chunks are laid out in a style similar to raid0, but
+ * near_copies copies of each chunk is stored (each on a different drive).
+ * The starting device for each section is offset near_copies from the starting
+ * device of the previous section.
+ * Thus they are (near_copies*far_copies) of each chunk, and each is on a different
+ * drive.
+ * near_copies and far_copies must be at least one, and their product is at most
+ * raid_disks.
+ *
+ * If far_offset is true, then the far_copies are handled a bit differently.
+ * The copies are still in different stripes, but instead of be very far apart
+ * on disk, there are adjacent stripes.
+ */
+
+/*
+ * Number of guaranteed r10bios in case of extreme VM load:
+ */
+#define NR_RAID10_BIOS 256
+
+/* When there are this many requests queue to be written by
+ * the raid10 thread, we become 'congested' to provide back-pressure
+ * for writeback.
+ */
+static int max_queued_requests = 1024;
+
+static void allow_barrier(struct r10conf *conf);
+static void lower_barrier(struct r10conf *conf);
+static int enough(struct r10conf *conf, int ignore);
+
+static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
+{
+ struct r10conf *conf = data;
+ int size = offsetof(struct r10bio, devs[conf->copies]);
+
+ /* allocate a r10bio with room for raid_disks entries in the
+ * bios array */
+ return kzalloc(size, gfp_flags);
+}
+
+static void r10bio_pool_free(void *r10_bio, void *data)
+{
+ kfree(r10_bio);
+}
+
+/* Maximum size of each resync request */
+#define RESYNC_BLOCK_SIZE (64*1024)
+#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
+/* amount of memory to reserve for resync requests */
+#define RESYNC_WINDOW (1024*1024)
+/* maximum number of concurrent requests, memory permitting */
+#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
+
+/*
+ * When performing a resync, we need to read and compare, so
+ * we need as many pages are there are copies.
+ * When performing a recovery, we need 2 bios, one for read,
+ * one for write (we recover only one drive per r10buf)
+ *
+ */
+static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
+{
+ struct r10conf *conf = data;
+ struct page *page;
+ struct r10bio *r10_bio;
+ struct bio *bio;
+ int i, j;
+ int nalloc;
+
+ r10_bio = r10bio_pool_alloc(gfp_flags, conf);
+ if (!r10_bio)
+ return NULL;
+
+ if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
+ nalloc = conf->copies; /* resync */
+ else
+ nalloc = 2; /* recovery */
+
+ /*
+ * Allocate bios.
+ */
+ for (j = nalloc ; j-- ; ) {
+ bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
+ if (!bio)
+ goto out_free_bio;
+ r10_bio->devs[j].bio = bio;
+ if (!conf->have_replacement)
+ continue;
+ bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
+ if (!bio)
+ goto out_free_bio;
+ r10_bio->devs[j].repl_bio = bio;
+ }
+ /*
+ * Allocate RESYNC_PAGES data pages and attach them
+ * where needed.
+ */
+ for (j = 0 ; j < nalloc; j++) {
+ struct bio *rbio = r10_bio->devs[j].repl_bio;
+ bio = r10_bio->devs[j].bio;
+ for (i = 0; i < RESYNC_PAGES; i++) {
+ if (j == 1 && !test_bit(MD_RECOVERY_SYNC,
+ &conf->mddev->recovery)) {
+ /* we can share bv_page's during recovery */
+ struct bio *rbio = r10_bio->devs[0].bio;
+ page = rbio->bi_io_vec[i].bv_page;
+ get_page(page);
+ } else
+ page = alloc_page(gfp_flags);
+ if (unlikely(!page))
+ goto out_free_pages;
+
+ bio->bi_io_vec[i].bv_page = page;
+ if (rbio)
+ rbio->bi_io_vec[i].bv_page = page;
+ }
+ }
+
+ return r10_bio;
+
+out_free_pages:
+ for ( ; i > 0 ; i--)
+ safe_put_page(bio->bi_io_vec[i-1].bv_page);
+ while (j--)
+ for (i = 0; i < RESYNC_PAGES ; i++)
+ safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
+ j = -1;
+out_free_bio:
+ while (++j < nalloc) {
+ bio_put(r10_bio->devs[j].bio);
+ if (r10_bio->devs[j].repl_bio)
+ bio_put(r10_bio->devs[j].repl_bio);
+ }
+ r10bio_pool_free(r10_bio, conf);
+ return NULL;
+}
+
+static void r10buf_pool_free(void *__r10_bio, void *data)
+{
+ int i;
+ struct r10conf *conf = data;
+ struct r10bio *r10bio = __r10_bio;
+ int j;
+
+ for (j=0; j < conf->copies; j++) {
+ struct bio *bio = r10bio->devs[j].bio;
+ if (bio) {
+ for (i = 0; i < RESYNC_PAGES; i++) {
+ safe_put_page(bio->bi_io_vec[i].bv_page);
+ bio->bi_io_vec[i].bv_page = NULL;
+ }
+ bio_put(bio);
+ }
+ bio = r10bio->devs[j].repl_bio;
+ if (bio)
+ bio_put(bio);
+ }
+ r10bio_pool_free(r10bio, conf);
+}
+
+static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio)
+{
+ int i;
+
+ for (i = 0; i < conf->copies; i++) {
+ struct bio **bio = & r10_bio->devs[i].bio;
+ if (!BIO_SPECIAL(*bio))
+ bio_put(*bio);
+ *bio = NULL;
+ bio = &r10_bio->devs[i].repl_bio;
+ if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio))
+ bio_put(*bio);
+ *bio = NULL;
+ }
+}
+
+static void free_r10bio(struct r10bio *r10_bio)
+{
+ struct r10conf *conf = r10_bio->mddev->private;
+
+ put_all_bios(conf, r10_bio);
+ mempool_free(r10_bio, conf->r10bio_pool);
+}
+
+static void put_buf(struct r10bio *r10_bio)
+{
+ struct r10conf *conf = r10_bio->mddev->private;
+
+ mempool_free(r10_bio, conf->r10buf_pool);
+
+ lower_barrier(conf);
+}
+
+static void reschedule_retry(struct r10bio *r10_bio)
+{
+ unsigned long flags;
+ struct mddev *mddev = r10_bio->mddev;
+ struct r10conf *conf = mddev->private;
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ list_add(&r10_bio->retry_list, &conf->retry_list);
+ conf->nr_queued ++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ /* wake up frozen array... */
+ wake_up(&conf->wait_barrier);
+
+ md_wakeup_thread(mddev->thread);
+}
+
+/*
+ * raid_end_bio_io() is called when we have finished servicing a mirrored
+ * operation and are ready to return a success/failure code to the buffer
+ * cache layer.
+ */
+static void raid_end_bio_io(struct r10bio *r10_bio)
+{
+ struct bio *bio = r10_bio->master_bio;
+ int done;
+ struct r10conf *conf = r10_bio->mddev->private;
+
+ if (bio->bi_phys_segments) {
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio->bi_phys_segments--;
+ done = (bio->bi_phys_segments == 0);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ } else
+ done = 1;
+ if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ if (done) {
+ bio_endio(bio, 0);
+ /*
+ * Wake up any possible resync thread that waits for the device
+ * to go idle.
+ */
+ allow_barrier(conf);
+ }
+ free_r10bio(r10_bio);
+}
+
+/*
+ * Update disk head position estimator based on IRQ completion info.
+ */
+static inline void update_head_pos(int slot, struct r10bio *r10_bio)
+{
+ struct r10conf *conf = r10_bio->mddev->private;
+
+ conf->mirrors[r10_bio->devs[slot].devnum].head_position =
+ r10_bio->devs[slot].addr + (r10_bio->sectors);
+}
+
+/*
+ * Find the disk number which triggered given bio
+ */
+static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio,
+ struct bio *bio, int *slotp, int *replp)
+{
+ int slot;
+ int repl = 0;
+
+ for (slot = 0; slot < conf->copies; slot++) {
+ if (r10_bio->devs[slot].bio == bio)
+ break;
+ if (r10_bio->devs[slot].repl_bio == bio) {
+ repl = 1;
+ break;
+ }
+ }
+
+ BUG_ON(slot == conf->copies);
+ update_head_pos(slot, r10_bio);
+
+ if (slotp)
+ *slotp = slot;
+ if (replp)
+ *replp = repl;
+ return r10_bio->devs[slot].devnum;
+}
+
+static void raid10_end_read_request(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct r10bio *r10_bio = bio->bi_private;
+ int slot, dev;
+ struct md_rdev *rdev;
+ struct r10conf *conf = r10_bio->mddev->private;
+
+
+ slot = r10_bio->read_slot;
+ dev = r10_bio->devs[slot].devnum;
+ rdev = r10_bio->devs[slot].rdev;
+ /*
+ * this branch is our 'one mirror IO has finished' event handler:
+ */
+ update_head_pos(slot, r10_bio);
+
+ if (uptodate) {
+ /*
+ * Set R10BIO_Uptodate in our master bio, so that
+ * we will return a good error code to the higher
+ * levels even if IO on some other mirrored buffer fails.
+ *
+ * The 'master' represents the composite IO operation to
+ * user-side. So if something waits for IO, then it will
+ * wait for the 'master' bio.
+ */
+ set_bit(R10BIO_Uptodate, &r10_bio->state);
+ } else {
+ /* If all other devices that store this block have
+ * failed, we want to return the error upwards rather
+ * than fail the last device. Here we redefine
+ * "uptodate" to mean "Don't want to retry"
+ */
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (!enough(conf, rdev->raid_disk))
+ uptodate = 1;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+ if (uptodate) {
+ raid_end_bio_io(r10_bio);
+ rdev_dec_pending(rdev, conf->mddev);
+ } else {
+ /*
+ * oops, read error - keep the refcount on the rdev
+ */
+ char b[BDEVNAME_SIZE];
+ printk_ratelimited(KERN_ERR
+ "md/raid10:%s: %s: rescheduling sector %llu\n",
+ mdname(conf->mddev),
+ bdevname(rdev->bdev, b),
+ (unsigned long long)r10_bio->sector);
+ set_bit(R10BIO_ReadError, &r10_bio->state);
+ reschedule_retry(r10_bio);
+ }
+}
+
+static void close_write(struct r10bio *r10_bio)
+{
+ /* clear the bitmap if all writes complete successfully */
+ bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
+ r10_bio->sectors,
+ !test_bit(R10BIO_Degraded, &r10_bio->state),
+ 0);
+ md_write_end(r10_bio->mddev);
+}
+
+static void one_write_done(struct r10bio *r10_bio)
+{
+ if (atomic_dec_and_test(&r10_bio->remaining)) {
+ if (test_bit(R10BIO_WriteError, &r10_bio->state))
+ reschedule_retry(r10_bio);
+ else {
+ close_write(r10_bio);
+ if (test_bit(R10BIO_MadeGood, &r10_bio->state))
+ reschedule_retry(r10_bio);
+ else
+ raid_end_bio_io(r10_bio);
+ }
+ }
+}
+
+static void raid10_end_write_request(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct r10bio *r10_bio = bio->bi_private;
+ int dev;
+ int dec_rdev = 1;
+ struct r10conf *conf = r10_bio->mddev->private;
+ int slot, repl;
+ struct md_rdev *rdev = NULL;
+
+ dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
+
+ if (repl)
+ rdev = conf->mirrors[dev].replacement;
+ if (!rdev) {
+ smp_rmb();
+ repl = 0;
+ rdev = conf->mirrors[dev].rdev;
+ }
+ /*
+ * this branch is our 'one mirror IO has finished' event handler:
+ */
+ if (!uptodate) {
+ if (repl)
+ /* Never record new bad blocks to replacement,
+ * just fail it.
+ */
+ md_error(rdev->mddev, rdev);
+ else {
+ set_bit(WriteErrorSeen, &rdev->flags);
+ if (!test_and_set_bit(WantReplacement, &rdev->flags))
+ set_bit(MD_RECOVERY_NEEDED,
+ &rdev->mddev->recovery);
+ set_bit(R10BIO_WriteError, &r10_bio->state);
+ dec_rdev = 0;
+ }
+ } else {
+ /*
+ * Set R10BIO_Uptodate in our master bio, so that
+ * we will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer fails.
+ *
+ * The 'master' represents the composite IO operation to
+ * user-side. So if something waits for IO, then it will
+ * wait for the 'master' bio.
+ */
+ sector_t first_bad;
+ int bad_sectors;
+
+ /*
+ * Do not set R10BIO_Uptodate if the current device is
+ * rebuilding or Faulty. This is because we cannot use
+ * such device for properly reading the data back (we could
+ * potentially use it, if the current write would have felt
+ * before rdev->recovery_offset, but for simplicity we don't
+ * check this here.
+ */
+ if (test_bit(In_sync, &rdev->flags) &&
+ !test_bit(Faulty, &rdev->flags))
+ set_bit(R10BIO_Uptodate, &r10_bio->state);
+
+ /* Maybe we can clear some bad blocks. */
+ if (is_badblock(rdev,
+ r10_bio->devs[slot].addr,
+ r10_bio->sectors,
+ &first_bad, &bad_sectors)) {
+ bio_put(bio);
+ if (repl)
+ r10_bio->devs[slot].repl_bio = IO_MADE_GOOD;
+ else
+ r10_bio->devs[slot].bio = IO_MADE_GOOD;
+ dec_rdev = 0;
+ set_bit(R10BIO_MadeGood, &r10_bio->state);
+ }
+ }
+
+ /*
+ *
+ * Let's see if all mirrored write operations have finished
+ * already.
+ */
+ one_write_done(r10_bio);
+ if (dec_rdev)
+ rdev_dec_pending(rdev, conf->mddev);
+}
+
+/*
+ * RAID10 layout manager
+ * As well as the chunksize and raid_disks count, there are two
+ * parameters: near_copies and far_copies.
+ * near_copies * far_copies must be <= raid_disks.
+ * Normally one of these will be 1.
+ * If both are 1, we get raid0.
+ * If near_copies == raid_disks, we get raid1.
+ *
+ * Chunks are laid out in raid0 style with near_copies copies of the
+ * first chunk, followed by near_copies copies of the next chunk and
+ * so on.
+ * If far_copies > 1, then after 1/far_copies of the array has been assigned
+ * as described above, we start again with a device offset of near_copies.
+ * So we effectively have another copy of the whole array further down all
+ * the drives, but with blocks on different drives.
+ * With this layout, and block is never stored twice on the one device.
+ *
+ * raid10_find_phys finds the sector offset of a given virtual sector
+ * on each device that it is on.
+ *
+ * raid10_find_virt does the reverse mapping, from a device and a
+ * sector offset to a virtual address
+ */
+
+static void raid10_find_phys(struct r10conf *conf, struct r10bio *r10bio)
+{
+ int n,f;
+ sector_t sector;
+ sector_t chunk;
+ sector_t stripe;
+ int dev;
+
+ int slot = 0;
+
+ /* now calculate first sector/dev */
+ chunk = r10bio->sector >> conf->chunk_shift;
+ sector = r10bio->sector & conf->chunk_mask;
+
+ chunk *= conf->near_copies;
+ stripe = chunk;
+ dev = sector_div(stripe, conf->raid_disks);
+ if (conf->far_offset)
+ stripe *= conf->far_copies;
+
+ sector += stripe << conf->chunk_shift;
+
+ /* and calculate all the others */
+ for (n=0; n < conf->near_copies; n++) {
+ int d = dev;
+ sector_t s = sector;
+ r10bio->devs[slot].addr = sector;
+ r10bio->devs[slot].devnum = d;
+ slot++;
+
+ for (f = 1; f < conf->far_copies; f++) {
+ d += conf->near_copies;
+ if (d >= conf->raid_disks)
+ d -= conf->raid_disks;
+ s += conf->stride;
+ r10bio->devs[slot].devnum = d;
+ r10bio->devs[slot].addr = s;
+ slot++;
+ }
+ dev++;
+ if (dev >= conf->raid_disks) {
+ dev = 0;
+ sector += (conf->chunk_mask + 1);
+ }
+ }
+ BUG_ON(slot != conf->copies);
+}
+
+static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev)
+{
+ sector_t offset, chunk, vchunk;
+
+ offset = sector & conf->chunk_mask;
+ if (conf->far_offset) {
+ int fc;
+ chunk = sector >> conf->chunk_shift;
+ fc = sector_div(chunk, conf->far_copies);
+ dev -= fc * conf->near_copies;
+ if (dev < 0)
+ dev += conf->raid_disks;
+ } else {
+ while (sector >= conf->stride) {
+ sector -= conf->stride;
+ if (dev < conf->near_copies)
+ dev += conf->raid_disks - conf->near_copies;
+ else
+ dev -= conf->near_copies;
+ }
+ chunk = sector >> conf->chunk_shift;
+ }
+ vchunk = chunk * conf->raid_disks + dev;
+ sector_div(vchunk, conf->near_copies);
+ return (vchunk << conf->chunk_shift) + offset;
+}
+
+/**
+ * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
+ * @q: request queue
+ * @bvm: properties of new bio
+ * @biovec: the request that could be merged to it.
+ *
+ * Return amount of bytes we can accept at this offset
+ * This requires checking for end-of-chunk if near_copies != raid_disks,
+ * and for subordinate merge_bvec_fns if merge_check_needed.
+ */
+static int raid10_mergeable_bvec(struct request_queue *q,
+ struct bvec_merge_data *bvm,
+ struct bio_vec *biovec)
+{
+ struct mddev *mddev = q->queuedata;
+ struct r10conf *conf = mddev->private;
+ sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
+ int max;
+ unsigned int chunk_sectors = mddev->chunk_sectors;
+ unsigned int bio_sectors = bvm->bi_size >> 9;
+
+ if (conf->near_copies < conf->raid_disks) {
+ max = (chunk_sectors - ((sector & (chunk_sectors - 1))
+ + bio_sectors)) << 9;
+ if (max < 0)
+ /* bio_add cannot handle a negative return */
+ max = 0;
+ if (max <= biovec->bv_len && bio_sectors == 0)
+ return biovec->bv_len;
+ } else
+ max = biovec->bv_len;
+
+ if (mddev->merge_check_needed) {
+ struct {
+ struct r10bio r10_bio;
+ struct r10dev devs[conf->copies];
+ } on_stack;
+ struct r10bio *r10_bio = &on_stack.r10_bio;
+ int s;
+ r10_bio->sector = sector;
+ raid10_find_phys(conf, r10_bio);
+ rcu_read_lock();
+ for (s = 0; s < conf->copies; s++) {
+ int disk = r10_bio->devs[s].devnum;
+ struct md_rdev *rdev = rcu_dereference(
+ conf->mirrors[disk].rdev);
+ if (rdev && !test_bit(Faulty, &rdev->flags)) {
+ struct request_queue *q =
+ bdev_get_queue(rdev->bdev);
+ if (q->merge_bvec_fn) {
+ bvm->bi_sector = r10_bio->devs[s].addr
+ + rdev->data_offset;
+ bvm->bi_bdev = rdev->bdev;
+ max = min(max, q->merge_bvec_fn(
+ q, bvm, biovec));
+ }
+ }
+ rdev = rcu_dereference(conf->mirrors[disk].replacement);
+ if (rdev && !test_bit(Faulty, &rdev->flags)) {
+ struct request_queue *q =
+ bdev_get_queue(rdev->bdev);
+ if (q->merge_bvec_fn) {
+ bvm->bi_sector = r10_bio->devs[s].addr
+ + rdev->data_offset;
+ bvm->bi_bdev = rdev->bdev;
+ max = min(max, q->merge_bvec_fn(
+ q, bvm, biovec));
+ }
+ }
+ }
+ rcu_read_unlock();
+ }
+ return max;
+}
+
+/*
+ * This routine returns the disk from which the requested read should
+ * be done. There is a per-array 'next expected sequential IO' sector
+ * number - if this matches on the next IO then we use the last disk.
+ * There is also a per-disk 'last know head position' sector that is
+ * maintained from IRQ contexts, both the normal and the resync IO
+ * completion handlers update this position correctly. If there is no
+ * perfect sequential match then we pick the disk whose head is closest.
+ *
+ * If there are 2 mirrors in the same 2 devices, performance degrades
+ * because position is mirror, not device based.
+ *
+ * The rdev for the device selected will have nr_pending incremented.
+ */
+
+/*
+ * FIXME: possibly should rethink readbalancing and do it differently
+ * depending on near_copies / far_copies geometry.
+ */
+static struct md_rdev *read_balance(struct r10conf *conf,
+ struct r10bio *r10_bio,
+ int *max_sectors)
+{
+ const sector_t this_sector = r10_bio->sector;
+ int disk, slot;
+ int sectors = r10_bio->sectors;
+ int best_good_sectors;
+ sector_t new_distance, best_dist;
+ struct md_rdev *rdev, *best_rdev;
+ int do_balance;
+ int best_slot;
+
+ raid10_find_phys(conf, r10_bio);
+ rcu_read_lock();
+retry:
+ sectors = r10_bio->sectors;
+ best_slot = -1;
+ best_rdev = NULL;
+ best_dist = MaxSector;
+ best_good_sectors = 0;
+ do_balance = 1;
+ /*
+ * Check if we can balance. We can balance on the whole
+ * device if no resync is going on (recovery is ok), or below
+ * the resync window. We take the first readable disk when
+ * above the resync window.
+ */
+ if (conf->mddev->recovery_cp < MaxSector
+ && (this_sector + sectors >= conf->next_resync))
+ do_balance = 0;
+
+ for (slot = 0; slot < conf->copies ; slot++) {
+ sector_t first_bad;
+ int bad_sectors;
+ sector_t dev_sector;
+
+ if (r10_bio->devs[slot].bio == IO_BLOCKED)
+ continue;
+ disk = r10_bio->devs[slot].devnum;
+ rdev = rcu_dereference(conf->mirrors[disk].replacement);
+ if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
+ test_bit(Unmerged, &rdev->flags) ||
+ r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
+ rdev = rcu_dereference(conf->mirrors[disk].rdev);
+ if (rdev == NULL ||
+ test_bit(Faulty, &rdev->flags) ||
+ test_bit(Unmerged, &rdev->flags))
+ continue;
+ if (!test_bit(In_sync, &rdev->flags) &&
+ r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
+ continue;
+
+ dev_sector = r10_bio->devs[slot].addr;
+ if (is_badblock(rdev, dev_sector, sectors,
+ &first_bad, &bad_sectors)) {
+ if (best_dist < MaxSector)
+ /* Already have a better slot */
+ continue;
+ if (first_bad <= dev_sector) {
+ /* Cannot read here. If this is the
+ * 'primary' device, then we must not read
+ * beyond 'bad_sectors' from another device.
+ */
+ bad_sectors -= (dev_sector - first_bad);
+ if (!do_balance && sectors > bad_sectors)
+ sectors = bad_sectors;
+ if (best_good_sectors > sectors)
+ best_good_sectors = sectors;
+ } else {
+ sector_t good_sectors =
+ first_bad - dev_sector;
+ if (good_sectors > best_good_sectors) {
+ best_good_sectors = good_sectors;
+ best_slot = slot;
+ best_rdev = rdev;
+ }
+ if (!do_balance)
+ /* Must read from here */
+ break;
+ }
+ continue;
+ } else
+ best_good_sectors = sectors;
+
+ if (!do_balance)
+ break;
+
+ /* This optimisation is debatable, and completely destroys
+ * sequential read speed for 'far copies' arrays. So only
+ * keep it for 'near' arrays, and review those later.
+ */
+ if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending))
+ break;
+
+ /* for far > 1 always use the lowest address */
+ if (conf->far_copies > 1)
+ new_distance = r10_bio->devs[slot].addr;
+ else
+ new_distance = abs(r10_bio->devs[slot].addr -
+ conf->mirrors[disk].head_position);
+ if (new_distance < best_dist) {
+ best_dist = new_distance;
+ best_slot = slot;
+ best_rdev = rdev;
+ }
+ }
+ if (slot >= conf->copies) {
+ slot = best_slot;
+ rdev = best_rdev;
+ }
+
+ if (slot >= 0) {
+ atomic_inc(&rdev->nr_pending);
+ if (test_bit(Faulty, &rdev->flags)) {
+ /* Cannot risk returning a device that failed
+ * before we inc'ed nr_pending
+ */
+ rdev_dec_pending(rdev, conf->mddev);
+ goto retry;
+ }
+ r10_bio->read_slot = slot;
+ } else
+ rdev = NULL;
+ rcu_read_unlock();
+ *max_sectors = best_good_sectors;
+
+ return rdev;
+}
+
+static int raid10_congested(void *data, int bits)
+{
+ struct mddev *mddev = data;
+ struct r10conf *conf = mddev->private;
+ int i, ret = 0;
+
+ if ((bits & (1 << BDI_async_congested)) &&
+ conf->pending_count >= max_queued_requests)
+ return 1;
+
+ if (mddev_congested(mddev, bits))
+ return 1;
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks && ret == 0; i++) {
+ struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev && !test_bit(Faulty, &rdev->flags)) {
+ struct request_queue *q = bdev_get_queue(rdev->bdev);
+
+ ret |= bdi_congested(&q->backing_dev_info, bits);
+ }
+ }
+ rcu_read_unlock();
+ return ret;
+}
+
+static void flush_pending_writes(struct r10conf *conf)
+{
+ /* Any writes that have been queued but are awaiting
+ * bitmap updates get flushed here.
+ */
+ spin_lock_irq(&conf->device_lock);
+
+ if (conf->pending_bio_list.head) {
+ struct bio *bio;
+ bio = bio_list_get(&conf->pending_bio_list);
+ conf->pending_count = 0;
+ spin_unlock_irq(&conf->device_lock);
+ /* flush any pending bitmap writes to disk
+ * before proceeding w/ I/O */
+ bitmap_unplug(conf->mddev->bitmap);
+ wake_up(&conf->wait_barrier);
+
+ while (bio) { /* submit pending writes */
+ struct bio *next = bio->bi_next;
+ bio->bi_next = NULL;
+ generic_make_request(bio);
+ bio = next;
+ }
+ } else
+ spin_unlock_irq(&conf->device_lock);
+}
+
+/* Barriers....
+ * Sometimes we need to suspend IO while we do something else,
+ * either some resync/recovery, or reconfigure the array.
+ * To do this we raise a 'barrier'.
+ * The 'barrier' is a counter that can be raised multiple times
+ * to count how many activities are happening which preclude
+ * normal IO.
+ * We can only raise the barrier if there is no pending IO.
+ * i.e. if nr_pending == 0.
+ * We choose only to raise the barrier if no-one is waiting for the
+ * barrier to go down. This means that as soon as an IO request
+ * is ready, no other operations which require a barrier will start
+ * until the IO request has had a chance.
+ *
+ * So: regular IO calls 'wait_barrier'. When that returns there
+ * is no backgroup IO happening, It must arrange to call
+ * allow_barrier when it has finished its IO.
+ * backgroup IO calls must call raise_barrier. Once that returns
+ * there is no normal IO happeing. It must arrange to call
+ * lower_barrier when the particular background IO completes.
+ */
+
+static void raise_barrier(struct r10conf *conf, int force)
+{
+ BUG_ON(force && !conf->barrier);
+ spin_lock_irq(&conf->resync_lock);
+
+ /* Wait until no block IO is waiting (unless 'force') */
+ wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
+ conf->resync_lock, );
+
+ /* block any new IO from starting */
+ conf->barrier++;
+
+ /* Now wait for all pending IO to complete */
+ wait_event_lock_irq(conf->wait_barrier,
+ !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
+ conf->resync_lock, );
+
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void lower_barrier(struct r10conf *conf)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&conf->resync_lock, flags);
+ conf->barrier--;
+ spin_unlock_irqrestore(&conf->resync_lock, flags);
+ wake_up(&conf->wait_barrier);
+}
+
+static void wait_barrier(struct r10conf *conf)
+{
+ spin_lock_irq(&conf->resync_lock);
+ if (conf->barrier) {
+ conf->nr_waiting++;
+ /* Wait for the barrier to drop.
+ * However if there are already pending
+ * requests (preventing the barrier from
+ * rising completely), and the
+ * pre-process bio queue isn't empty,
+ * then don't wait, as we need to empty
+ * that queue to get the nr_pending
+ * count down.
+ */
+ wait_event_lock_irq(conf->wait_barrier,
+ !conf->barrier ||
+ (conf->nr_pending &&
+ current->bio_list &&
+ !bio_list_empty(current->bio_list)),
+ conf->resync_lock,
+ );
+ conf->nr_waiting--;
+ }
+ conf->nr_pending++;
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void allow_barrier(struct r10conf *conf)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&conf->resync_lock, flags);
+ conf->nr_pending--;
+ spin_unlock_irqrestore(&conf->resync_lock, flags);
+ wake_up(&conf->wait_barrier);
+}
+
+static void freeze_array(struct r10conf *conf, int extra)
+{
+ /* stop syncio and normal IO and wait for everything to
+ * go quiet.
+ * We increment barrier and nr_waiting, and then
+ * wait until nr_pending match nr_queued+extra
+ * This is called in the context of one normal IO request
+ * that has failed. Thus any sync request that might be pending
+ * will be blocked by nr_pending, and we need to wait for
+ * pending IO requests to complete or be queued for re-try.
+ * Thus the number queued (nr_queued) plus this request (extra)
+ * must match the number of pending IOs (nr_pending) before
+ * we continue.
+ */
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier++;
+ conf->nr_waiting++;
+ wait_event_lock_irq(conf->wait_barrier,
+ conf->nr_pending == conf->nr_queued+extra,
+ conf->resync_lock,
+ flush_pending_writes(conf));
+
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void unfreeze_array(struct r10conf *conf)
+{
+ /* reverse the effect of the freeze */
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier--;
+ conf->nr_waiting--;
+ wake_up(&conf->wait_barrier);
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void make_request(struct mddev *mddev, struct bio * bio)
+{
+ struct r10conf *conf = mddev->private;
+ struct r10bio *r10_bio;
+ struct bio *read_bio;
+ int i;
+ int chunk_sects = conf->chunk_mask + 1;
+ const int rw = bio_data_dir(bio);
+ const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
+ const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
+ unsigned long flags;
+ struct md_rdev *blocked_rdev;
+ int plugged;
+ int sectors_handled;
+ int max_sectors;
+
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
+ return;
+ }
+
+ /* If this request crosses a chunk boundary, we need to
+ * split it. This will only happen for 1 PAGE (or less) requests.
+ */
+ if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9)
+ > chunk_sects &&
+ conf->near_copies < conf->raid_disks)) {
+ struct bio_pair *bp;
+ /* Sanity check -- queue functions should prevent this happening */
+ if (bio->bi_vcnt != 1 ||
+ bio->bi_idx != 0)
+ goto bad_map;
+ /* This is a one page bio that upper layers
+ * refuse to split for us, so we need to split it.
+ */
+ bp = bio_split(bio,
+ chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
+
+ /* Each of these 'make_request' calls will call 'wait_barrier'.
+ * If the first succeeds but the second blocks due to the resync
+ * thread raising the barrier, we will deadlock because the
+ * IO to the underlying device will be queued in generic_make_request
+ * and will never complete, so will never reduce nr_pending.
+ * So increment nr_waiting here so no new raise_barriers will
+ * succeed, and so the second wait_barrier cannot block.
+ */
+ spin_lock_irq(&conf->resync_lock);
+ conf->nr_waiting++;
+ spin_unlock_irq(&conf->resync_lock);
+
+ make_request(mddev, &bp->bio1);
+ make_request(mddev, &bp->bio2);
+
+ spin_lock_irq(&conf->resync_lock);
+ conf->nr_waiting--;
+ wake_up(&conf->wait_barrier);
+ spin_unlock_irq(&conf->resync_lock);
+
+ bio_pair_release(bp);
+ return;
+ bad_map:
+ printk("md/raid10:%s: make_request bug: can't convert block across chunks"
+ " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2,
+ (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
+
+ bio_io_error(bio);
+ return;
+ }
+
+ md_write_start(mddev, bio);
+
+ /*
+ * Register the new request and wait if the reconstruction
+ * thread has put up a bar for new requests.
+ * Continue immediately if no resync is active currently.
+ */
+ wait_barrier(conf);
+
+ r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
+
+ r10_bio->master_bio = bio;
+ r10_bio->sectors = bio->bi_size >> 9;
+
+ r10_bio->mddev = mddev;
+ r10_bio->sector = bio->bi_sector;
+ r10_bio->state = 0;
+
+ /* We might need to issue multiple reads to different
+ * devices if there are bad blocks around, so we keep
+ * track of the number of reads in bio->bi_phys_segments.
+ * If this is 0, there is only one r10_bio and no locking
+ * will be needed when the request completes. If it is
+ * non-zero, then it is the number of not-completed requests.
+ */
+ bio->bi_phys_segments = 0;
+ clear_bit(BIO_SEG_VALID, &bio->bi_flags);
+
+ if (rw == READ) {
+ /*
+ * read balancing logic:
+ */
+ struct md_rdev *rdev;
+ int slot;
+
+read_again:
+ rdev = read_balance(conf, r10_bio, &max_sectors);
+ if (!rdev) {
+ raid_end_bio_io(r10_bio);
+ return;
+ }
+ slot = r10_bio->read_slot;
+
+ read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(read_bio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
+
+ r10_bio->devs[slot].bio = read_bio;
+ r10_bio->devs[slot].rdev = rdev;
+
+ read_bio->bi_sector = r10_bio->devs[slot].addr +
+ rdev->data_offset;
+ read_bio->bi_bdev = rdev->bdev;
+ read_bio->bi_end_io = raid10_end_read_request;
+ read_bio->bi_rw = READ | do_sync;
+ read_bio->bi_private = r10_bio;
+
+ if (max_sectors < r10_bio->sectors) {
+ /* Could not read all from this device, so we will
+ * need another r10_bio.
+ */
+ sectors_handled = (r10_bio->sector + max_sectors
+ - bio->bi_sector);
+ r10_bio->sectors = max_sectors;
+ spin_lock_irq(&conf->device_lock);
+ if (bio->bi_phys_segments == 0)
+ bio->bi_phys_segments = 2;
+ else
+ bio->bi_phys_segments++;
+ spin_unlock_irq(&conf->device_lock);
+ /* Cannot call generic_make_request directly
+ * as that will be queued in __generic_make_request
+ * and subsequent mempool_alloc might block
+ * waiting for it. so hand bio over to raid10d.
+ */
+ reschedule_retry(r10_bio);
+
+ r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
+
+ r10_bio->master_bio = bio;
+ r10_bio->sectors = ((bio->bi_size >> 9)
+ - sectors_handled);
+ r10_bio->state = 0;
+ r10_bio->mddev = mddev;
+ r10_bio->sector = bio->bi_sector + sectors_handled;
+ goto read_again;
+ } else
+ generic_make_request(read_bio);
+ return;
+ }
+
+ /*
+ * WRITE:
+ */
+ if (conf->pending_count >= max_queued_requests) {
+ md_wakeup_thread(mddev->thread);
+ wait_event(conf->wait_barrier,
+ conf->pending_count < max_queued_requests);
+ }
+ /* first select target devices under rcu_lock and
+ * inc refcount on their rdev. Record them by setting
+ * bios[x] to bio
+ * If there are known/acknowledged bad blocks on any device
+ * on which we have seen a write error, we want to avoid
+ * writing to those blocks. This potentially requires several
+ * writes to write around the bad blocks. Each set of writes
+ * gets its own r10_bio with a set of bios attached. The number
+ * of r10_bios is recored in bio->bi_phys_segments just as with
+ * the read case.
+ */
+ plugged = mddev_check_plugged(mddev);
+
+ r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
+ raid10_find_phys(conf, r10_bio);
+retry_write:
+ blocked_rdev = NULL;
+ rcu_read_lock();
+ max_sectors = r10_bio->sectors;
+
+ for (i = 0; i < conf->copies; i++) {
+ int d = r10_bio->devs[i].devnum;
+ struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
+ struct md_rdev *rrdev = rcu_dereference(
+ conf->mirrors[d].replacement);
+ if (rdev == rrdev)
+ rrdev = NULL;
+ if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+ atomic_inc(&rdev->nr_pending);
+ blocked_rdev = rdev;
+ break;
+ }
+ if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
+ atomic_inc(&rrdev->nr_pending);
+ blocked_rdev = rrdev;
+ break;
+ }
+ if (rdev && (test_bit(Faulty, &rdev->flags)
+ || test_bit(Unmerged, &rdev->flags)))
+ rdev = NULL;
+ if (rrdev && (test_bit(Faulty, &rrdev->flags)
+ || test_bit(Unmerged, &rrdev->flags)))
+ rrdev = NULL;
+
+ r10_bio->devs[i].bio = NULL;
+ r10_bio->devs[i].repl_bio = NULL;
+
+ if (!rdev && !rrdev) {
+ set_bit(R10BIO_Degraded, &r10_bio->state);
+ continue;
+ }
+ if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
+ sector_t first_bad;
+ sector_t dev_sector = r10_bio->devs[i].addr;
+ int bad_sectors;
+ int is_bad;
+
+ is_bad = is_badblock(rdev, dev_sector,
+ max_sectors,
+ &first_bad, &bad_sectors);
+ if (is_bad < 0) {
+ /* Mustn't write here until the bad block
+ * is acknowledged
+ */
+ atomic_inc(&rdev->nr_pending);
+ set_bit(BlockedBadBlocks, &rdev->flags);
+ blocked_rdev = rdev;
+ break;
+ }
+ if (is_bad && first_bad <= dev_sector) {
+ /* Cannot write here at all */
+ bad_sectors -= (dev_sector - first_bad);
+ if (bad_sectors < max_sectors)
+ /* Mustn't write more than bad_sectors
+ * to other devices yet
+ */
+ max_sectors = bad_sectors;
+ /* We don't set R10BIO_Degraded as that
+ * only applies if the disk is missing,
+ * so it might be re-added, and we want to
+ * know to recover this chunk.
+ * In this case the device is here, and the
+ * fact that this chunk is not in-sync is
+ * recorded in the bad block log.
+ */
+ continue;
+ }
+ if (is_bad) {
+ int good_sectors = first_bad - dev_sector;
+ if (good_sectors < max_sectors)
+ max_sectors = good_sectors;
+ }
+ }
+ if (rdev) {
+ r10_bio->devs[i].bio = bio;
+ atomic_inc(&rdev->nr_pending);
+ }
+ if (rrdev) {
+ r10_bio->devs[i].repl_bio = bio;
+ atomic_inc(&rrdev->nr_pending);
+ }
+ }
+ rcu_read_unlock();
+
+ if (unlikely(blocked_rdev)) {
+ /* Have to wait for this device to get unblocked, then retry */
+ int j;
+ int d;
+
+ for (j = 0; j < i; j++) {
+ if (r10_bio->devs[j].bio) {
+ d = r10_bio->devs[j].devnum;
+ rdev_dec_pending(conf->mirrors[d].rdev, mddev);
+ }
+ if (r10_bio->devs[j].repl_bio) {
+ struct md_rdev *rdev;
+ d = r10_bio->devs[j].devnum;
+ rdev = conf->mirrors[d].replacement;
+ if (!rdev) {
+ /* Race with remove_disk */
+ smp_mb();
+ rdev = conf->mirrors[d].rdev;
+ }
+ rdev_dec_pending(rdev, mddev);
+ }
+ }
+ allow_barrier(conf);
+ md_wait_for_blocked_rdev(blocked_rdev, mddev);
+ wait_barrier(conf);
+ goto retry_write;
+ }
+
+ if (max_sectors < r10_bio->sectors) {
+ /* We are splitting this into multiple parts, so
+ * we need to prepare for allocating another r10_bio.
+ */
+ r10_bio->sectors = max_sectors;
+ spin_lock_irq(&conf->device_lock);
+ if (bio->bi_phys_segments == 0)
+ bio->bi_phys_segments = 2;
+ else
+ bio->bi_phys_segments++;
+ spin_unlock_irq(&conf->device_lock);
+ }
+ sectors_handled = r10_bio->sector + max_sectors - bio->bi_sector;
+
+ atomic_set(&r10_bio->remaining, 1);
+ bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
+
+ for (i = 0; i < conf->copies; i++) {
+ struct bio *mbio;
+ int d = r10_bio->devs[i].devnum;
+ if (r10_bio->devs[i].bio) {
+ struct md_rdev *rdev = conf->mirrors[d].rdev;
+ mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
+ r10_bio->devs[i].bio = mbio;
+
+ mbio->bi_sector = (r10_bio->devs[i].addr+
+ rdev->data_offset);
+ mbio->bi_bdev = rdev->bdev;
+ mbio->bi_end_io = raid10_end_write_request;
+ mbio->bi_rw = WRITE | do_sync | do_fua;
+ mbio->bi_private = r10_bio;
+
+ atomic_inc(&r10_bio->remaining);
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio_list_add(&conf->pending_bio_list, mbio);
+ conf->pending_count++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+
+ if (r10_bio->devs[i].repl_bio) {
+ struct md_rdev *rdev = conf->mirrors[d].replacement;
+ if (rdev == NULL) {
+ /* Replacement just got moved to main 'rdev' */
+ smp_mb();
+ rdev = conf->mirrors[d].rdev;
+ }
+ mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
+ r10_bio->devs[i].repl_bio = mbio;
+
+ mbio->bi_sector = (r10_bio->devs[i].addr+
+ rdev->data_offset);
+ mbio->bi_bdev = rdev->bdev;
+ mbio->bi_end_io = raid10_end_write_request;
+ mbio->bi_rw = WRITE | do_sync | do_fua;
+ mbio->bi_private = r10_bio;
+
+ atomic_inc(&r10_bio->remaining);
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio_list_add(&conf->pending_bio_list, mbio);
+ conf->pending_count++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+ }
+
+ /* Don't remove the bias on 'remaining' (one_write_done) until
+ * after checking if we need to go around again.
+ */
+
+ if (sectors_handled < (bio->bi_size >> 9)) {
+ one_write_done(r10_bio);
+ /* We need another r10_bio. It has already been counted
+ * in bio->bi_phys_segments.
+ */
+ r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
+
+ r10_bio->master_bio = bio;
+ r10_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
+
+ r10_bio->mddev = mddev;
+ r10_bio->sector = bio->bi_sector + sectors_handled;
+ r10_bio->state = 0;
+ goto retry_write;
+ }
+ one_write_done(r10_bio);
+
+ /* In case raid10d snuck in to freeze_array */
+ wake_up(&conf->wait_barrier);
+
+ if (do_sync || !mddev->bitmap || !plugged)
+ md_wakeup_thread(mddev->thread);
+}
+
+static void status(struct seq_file *seq, struct mddev *mddev)
+{
+ struct r10conf *conf = mddev->private;
+ int i;
+
+ if (conf->near_copies < conf->raid_disks)
+ seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
+ if (conf->near_copies > 1)
+ seq_printf(seq, " %d near-copies", conf->near_copies);
+ if (conf->far_copies > 1) {
+ if (conf->far_offset)
+ seq_printf(seq, " %d offset-copies", conf->far_copies);
+ else
+ seq_printf(seq, " %d far-copies", conf->far_copies);
+ }
+ seq_printf(seq, " [%d/%d] [", conf->raid_disks,
+ conf->raid_disks - mddev->degraded);
+ for (i = 0; i < conf->raid_disks; i++)
+ seq_printf(seq, "%s",
+ conf->mirrors[i].rdev &&
+ test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
+ seq_printf(seq, "]");
+}
+
+/* check if there are enough drives for
+ * every block to appear on atleast one.
+ * Don't consider the device numbered 'ignore'
+ * as we might be about to remove it.
+ */
+static int enough(struct r10conf *conf, int ignore)
+{
+ int first = 0;
+
+ do {
+ int n = conf->copies;
+ int cnt = 0;
+ int this = first;
+ while (n--) {
+ if (conf->mirrors[this].rdev &&
+ this != ignore)
+ cnt++;
+ this = (this+1) % conf->raid_disks;
+ }
+ if (cnt == 0)
+ return 0;
+ first = (first + conf->near_copies) % conf->raid_disks;
+ } while (first != 0);
+ return 1;
+}
+
+static void error(struct mddev *mddev, struct md_rdev *rdev)
+{
+ char b[BDEVNAME_SIZE];
+ struct r10conf *conf = mddev->private;
+
+ /*
+ * If it is not operational, then we have already marked it as dead
+ * else if it is the last working disks, ignore the error, let the
+ * next level up know.
+ * else mark the drive as failed
+ */
+ if (test_bit(In_sync, &rdev->flags)
+ && !enough(conf, rdev->raid_disk))
+ /*
+ * Don't fail the drive, just return an IO error.
+ */
+ return;
+ if (test_and_clear_bit(In_sync, &rdev->flags)) {
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ /*
+ * if recovery is running, make sure it aborts.
+ */
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+ }
+ set_bit(Blocked, &rdev->flags);
+ set_bit(Faulty, &rdev->flags);
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ printk(KERN_ALERT
+ "md/raid10:%s: Disk failure on %s, disabling device.\n"
+ "md/raid10:%s: Operation continuing on %d devices.\n",
+ mdname(mddev), bdevname(rdev->bdev, b),
+ mdname(mddev), conf->raid_disks - mddev->degraded);
+}
+
+static void print_conf(struct r10conf *conf)
+{
+ int i;
+ struct mirror_info *tmp;
+
+ printk(KERN_DEBUG "RAID10 conf printout:\n");
+ if (!conf) {
+ printk(KERN_DEBUG "(!conf)\n");
+ return;
+ }
+ printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
+ conf->raid_disks);
+
+ for (i = 0; i < conf->raid_disks; i++) {
+ char b[BDEVNAME_SIZE];
+ tmp = conf->mirrors + i;
+ if (tmp->rdev)
+ printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
+ i, !test_bit(In_sync, &tmp->rdev->flags),
+ !test_bit(Faulty, &tmp->rdev->flags),
+ bdevname(tmp->rdev->bdev,b));
+ }
+}
+
+static void close_sync(struct r10conf *conf)
+{
+ wait_barrier(conf);
+ allow_barrier(conf);
+
+ mempool_destroy(conf->r10buf_pool);
+ conf->r10buf_pool = NULL;
+}
+
+static int raid10_spare_active(struct mddev *mddev)
+{
+ int i;
+ struct r10conf *conf = mddev->private;
+ struct mirror_info *tmp;
+ int count = 0;
+ unsigned long flags;
+
+ /*
+ * Find all non-in_sync disks within the RAID10 configuration
+ * and mark them in_sync
+ */
+ for (i = 0; i < conf->raid_disks; i++) {
+ tmp = conf->mirrors + i;
+ if (tmp->replacement
+ && tmp->replacement->recovery_offset == MaxSector
+ && !test_bit(Faulty, &tmp->replacement->flags)
+ && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
+ /* Replacement has just become active */
+ if (!tmp->rdev
+ || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
+ count++;
+ if (tmp->rdev) {
+ /* Replaced device not technically faulty,
+ * but we need to be sure it gets removed
+ * and never re-added.
+ */
+ set_bit(Faulty, &tmp->rdev->flags);
+ sysfs_notify_dirent_safe(
+ tmp->rdev->sysfs_state);
+ }
+ sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
+ } else if (tmp->rdev
+ && tmp->rdev->recovery_offset == MaxSector
+ && !test_bit(Faulty, &tmp->rdev->flags)
+ && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
+ count++;
+ sysfs_notify_dirent(tmp->rdev->sysfs_state);
+ }
+ }
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded -= count;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ print_conf(conf);
+ return count;
+}
+
+
+static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
+{
+ struct r10conf *conf = mddev->private;
+ int err = -EEXIST;
+ int mirror;
+ int first = 0;
+ int last = conf->raid_disks - 1;
+ struct request_queue *q = bdev_get_queue(rdev->bdev);
+
+ if (mddev->recovery_cp < MaxSector)
+ /* only hot-add to in-sync arrays, as recovery is
+ * very different from resync
+ */
+ return -EBUSY;
+ if (rdev->saved_raid_disk < 0 && !enough(conf, -1))
+ return -EINVAL;
+
+ if (rdev->raid_disk >= 0)
+ first = last = rdev->raid_disk;
+
+ if (q->merge_bvec_fn) {
+ set_bit(Unmerged, &rdev->flags);
+ mddev->merge_check_needed = 1;
+ }
+
+ if (rdev->saved_raid_disk >= first &&
+ conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
+ mirror = rdev->saved_raid_disk;
+ else
+ mirror = first;
+ for ( ; mirror <= last ; mirror++) {
+ struct mirror_info *p = &conf->mirrors[mirror];
+ if (p->recovery_disabled == mddev->recovery_disabled)
+ continue;
+ if (p->rdev) {
+ if (!test_bit(WantReplacement, &p->rdev->flags) ||
+ p->replacement != NULL)
+ continue;
+ clear_bit(In_sync, &rdev->flags);
+ set_bit(Replacement, &rdev->flags);
+ rdev->raid_disk = mirror;
+ err = 0;
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+ conf->fullsync = 1;
+ rcu_assign_pointer(p->replacement, rdev);
+ break;
+ }
+
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+
+ p->head_position = 0;
+ p->recovery_disabled = mddev->recovery_disabled - 1;
+ rdev->raid_disk = mirror;
+ err = 0;
+ if (rdev->saved_raid_disk != mirror)
+ conf->fullsync = 1;
+ rcu_assign_pointer(p->rdev, rdev);
+ break;
+ }
+ if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
+ /* Some requests might not have seen this new
+ * merge_bvec_fn. We must wait for them to complete
+ * before merging the device fully.
+ * First we make sure any code which has tested
+ * our function has submitted the request, then
+ * we wait for all outstanding requests to complete.
+ */
+ synchronize_sched();
+ freeze_array(conf, 0);
+ unfreeze_array(conf);
+ clear_bit(Unmerged, &rdev->flags);
+ }
+ md_integrity_add_rdev(rdev, mddev);
+ print_conf(conf);
+ return err;
+}
+
+static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
+{
+ struct r10conf *conf = mddev->private;
+ int err = 0;
+ int number = rdev->raid_disk;
+ struct md_rdev **rdevp;
+ struct mirror_info *p = conf->mirrors + number;
+
+ print_conf(conf);
+ if (rdev == p->rdev)
+ rdevp = &p->rdev;
+ else if (rdev == p->replacement)
+ rdevp = &p->replacement;
+ else
+ return 0;
+
+ if (test_bit(In_sync, &rdev->flags) ||
+ atomic_read(&rdev->nr_pending)) {
+ err = -EBUSY;
+ goto abort;
+ }
+ /* Only remove faulty devices if recovery
+ * is not possible.
+ */
+ if (!test_bit(Faulty, &rdev->flags) &&
+ mddev->recovery_disabled != p->recovery_disabled &&
+ (!p->replacement || p->replacement == rdev) &&
+ enough(conf, -1)) {
+ err = -EBUSY;
+ goto abort;
+ }
+ *rdevp = NULL;
+ synchronize_rcu();
+ if (atomic_read(&rdev->nr_pending)) {
+ /* lost the race, try later */
+ err = -EBUSY;
+ *rdevp = rdev;
+ goto abort;
+ } else if (p->replacement) {
+ /* We must have just cleared 'rdev' */
+ p->rdev = p->replacement;
+ clear_bit(Replacement, &p->replacement->flags);
+ smp_mb(); /* Make sure other CPUs may see both as identical
+ * but will never see neither -- if they are careful.
+ */
+ p->replacement = NULL;
+ clear_bit(WantReplacement, &rdev->flags);
+ } else
+ /* We might have just remove the Replacement as faulty
+ * Clear the flag just in case
+ */
+ clear_bit(WantReplacement, &rdev->flags);
+
+ err = md_integrity_register(mddev);
+
+abort:
+
+ print_conf(conf);
+ return err;
+}
+
+
+static void end_sync_read(struct bio *bio, int error)
+{
+ struct r10bio *r10_bio = bio->bi_private;
+ struct r10conf *conf = r10_bio->mddev->private;
+ int d;
+
+ d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
+
+ if (test_bit(BIO_UPTODATE, &bio->bi_flags))
+ set_bit(R10BIO_Uptodate, &r10_bio->state);
+ else
+ /* The write handler will notice the lack of
+ * R10BIO_Uptodate and record any errors etc
+ */
+ atomic_add(r10_bio->sectors,
+ &conf->mirrors[d].rdev->corrected_errors);
+
+ /* for reconstruct, we always reschedule after a read.
+ * for resync, only after all reads
+ */
+ rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
+ if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
+ atomic_dec_and_test(&r10_bio->remaining)) {
+ /* we have read all the blocks,
+ * do the comparison in process context in raid10d
+ */
+ reschedule_retry(r10_bio);
+ }
+}
+
+static void end_sync_request(struct r10bio *r10_bio)
+{
+ struct mddev *mddev = r10_bio->mddev;
+
+ while (atomic_dec_and_test(&r10_bio->remaining)) {
+ if (r10_bio->master_bio == NULL) {
+ /* the primary of several recovery bios */
+ sector_t s = r10_bio->sectors;
+ if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
+ test_bit(R10BIO_WriteError, &r10_bio->state))
+ reschedule_retry(r10_bio);
+ else
+ put_buf(r10_bio);
+ md_done_sync(mddev, s, 1);
+ break;
+ } else {
+ struct r10bio *r10_bio2 = (struct r10bio *)r10_bio->master_bio;
+ if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
+ test_bit(R10BIO_WriteError, &r10_bio->state))
+ reschedule_retry(r10_bio);
+ else
+ put_buf(r10_bio);
+ r10_bio = r10_bio2;
+ }
+ }
+}
+
+static void end_sync_write(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct r10bio *r10_bio = bio->bi_private;
+ struct mddev *mddev = r10_bio->mddev;
+ struct r10conf *conf = mddev->private;
+ int d;
+ sector_t first_bad;
+ int bad_sectors;
+ int slot;
+ int repl;
+ struct md_rdev *rdev = NULL;
+
+ d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
+ if (repl)
+ rdev = conf->mirrors[d].replacement;
+ else
+ rdev = conf->mirrors[d].rdev;
+
+ if (!uptodate) {
+ if (repl)
+ md_error(mddev, rdev);
+ else {
+ set_bit(WriteErrorSeen, &rdev->flags);
+ if (!test_and_set_bit(WantReplacement, &rdev->flags))
+ set_bit(MD_RECOVERY_NEEDED,
+ &rdev->mddev->recovery);
+ set_bit(R10BIO_WriteError, &r10_bio->state);
+ }
+ } else if (is_badblock(rdev,
+ r10_bio->devs[slot].addr,
+ r10_bio->sectors,
+ &first_bad, &bad_sectors))
+ set_bit(R10BIO_MadeGood, &r10_bio->state);
+
+ rdev_dec_pending(rdev, mddev);
+
+ end_sync_request(r10_bio);
+}
+
+/*
+ * Note: sync and recover and handled very differently for raid10
+ * This code is for resync.
+ * For resync, we read through virtual addresses and read all blocks.
+ * If there is any error, we schedule a write. The lowest numbered
+ * drive is authoritative.
+ * However requests come for physical address, so we need to map.
+ * For every physical address there are raid_disks/copies virtual addresses,
+ * which is always are least one, but is not necessarly an integer.
+ * This means that a physical address can span multiple chunks, so we may
+ * have to submit multiple io requests for a single sync request.
+ */
+/*
+ * We check if all blocks are in-sync and only write to blocks that
+ * aren't in sync
+ */
+static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
+{
+ struct r10conf *conf = mddev->private;
+ int i, first;
+ struct bio *tbio, *fbio;
+ int vcnt;
+
+ atomic_set(&r10_bio->remaining, 1);
+
+ /* find the first device with a block */
+ for (i=0; i<conf->copies; i++)
+ if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags))
+ break;
+
+ if (i == conf->copies)
+ goto done;
+
+ first = i;
+ fbio = r10_bio->devs[i].bio;
+
+ vcnt = (r10_bio->sectors + (PAGE_SIZE >> 9) - 1) >> (PAGE_SHIFT - 9);
+ /* now find blocks with errors */
+ for (i=0 ; i < conf->copies ; i++) {
+ int j, d;
+
+ tbio = r10_bio->devs[i].bio;
+
+ if (tbio->bi_end_io != end_sync_read)
+ continue;
+ if (i == first)
+ continue;
+ if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) {
+ /* We know that the bi_io_vec layout is the same for
+ * both 'first' and 'i', so we just compare them.
+ * All vec entries are PAGE_SIZE;
+ */
+ for (j = 0; j < vcnt; j++)
+ if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
+ page_address(tbio->bi_io_vec[j].bv_page),
+ fbio->bi_io_vec[j].bv_len))
+ break;
+ if (j == vcnt)
+ continue;
+ mddev->resync_mismatches += r10_bio->sectors;
+ if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
+ /* Don't fix anything. */
+ continue;
+ }
+ /* Ok, we need to write this bio, either to correct an
+ * inconsistency or to correct an unreadable block.
+ * First we need to fixup bv_offset, bv_len and
+ * bi_vecs, as the read request might have corrupted these
+ */
+ tbio->bi_vcnt = vcnt;
+ tbio->bi_size = r10_bio->sectors << 9;
+ tbio->bi_idx = 0;
+ tbio->bi_phys_segments = 0;
+ tbio->bi_flags &= ~(BIO_POOL_MASK - 1);
+ tbio->bi_flags |= 1 << BIO_UPTODATE;
+ tbio->bi_next = NULL;
+ tbio->bi_rw = WRITE;
+ tbio->bi_private = r10_bio;
+ tbio->bi_sector = r10_bio->devs[i].addr;
+
+ for (j=0; j < vcnt ; j++) {
+ tbio->bi_io_vec[j].bv_offset = 0;
+ tbio->bi_io_vec[j].bv_len = PAGE_SIZE;
+
+ memcpy(page_address(tbio->bi_io_vec[j].bv_page),
+ page_address(fbio->bi_io_vec[j].bv_page),
+ PAGE_SIZE);
+ }
+ tbio->bi_end_io = end_sync_write;
+
+ d = r10_bio->devs[i].devnum;
+ atomic_inc(&conf->mirrors[d].rdev->nr_pending);
+ atomic_inc(&r10_bio->remaining);
+ md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9);
+
+ tbio->bi_sector += conf->mirrors[d].rdev->data_offset;
+ tbio->bi_bdev = conf->mirrors[d].rdev->bdev;
+ generic_make_request(tbio);
+ }
+
+ /* Now write out to any replacement devices
+ * that are active
+ */
+ for (i = 0; i < conf->copies; i++) {
+ int j, d;
+
+ tbio = r10_bio->devs[i].repl_bio;
+ if (!tbio || !tbio->bi_end_io)
+ continue;
+ if (r10_bio->devs[i].bio->bi_end_io != end_sync_write
+ && r10_bio->devs[i].bio != fbio)
+ for (j = 0; j < vcnt; j++)
+ memcpy(page_address(tbio->bi_io_vec[j].bv_page),
+ page_address(fbio->bi_io_vec[j].bv_page),
+ PAGE_SIZE);
+ d = r10_bio->devs[i].devnum;
+ atomic_inc(&r10_bio->remaining);
+ md_sync_acct(conf->mirrors[d].replacement->bdev,
+ tbio->bi_size >> 9);
+ generic_make_request(tbio);
+ }
+
+done:
+ if (atomic_dec_and_test(&r10_bio->remaining)) {
+ md_done_sync(mddev, r10_bio->sectors, 1);
+ put_buf(r10_bio);
+ }
+}
+
+/*
+ * Now for the recovery code.
+ * Recovery happens across physical sectors.
+ * We recover all non-is_sync drives by finding the virtual address of
+ * each, and then choose a working drive that also has that virt address.
+ * There is a separate r10_bio for each non-in_sync drive.
+ * Only the first two slots are in use. The first for reading,
+ * The second for writing.
+ *
+ */
+static void fix_recovery_read_error(struct r10bio *r10_bio)
+{
+ /* We got a read error during recovery.
+ * We repeat the read in smaller page-sized sections.
+ * If a read succeeds, write it to the new device or record
+ * a bad block if we cannot.
+ * If a read fails, record a bad block on both old and
+ * new devices.
+ */
+ struct mddev *mddev = r10_bio->mddev;
+ struct r10conf *conf = mddev->private;
+ struct bio *bio = r10_bio->devs[0].bio;
+ sector_t sect = 0;
+ int sectors = r10_bio->sectors;
+ int idx = 0;
+ int dr = r10_bio->devs[0].devnum;
+ int dw = r10_bio->devs[1].devnum;
+
+ while (sectors) {
+ int s = sectors;
+ struct md_rdev *rdev;
+ sector_t addr;
+ int ok;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+
+ rdev = conf->mirrors[dr].rdev;
+ addr = r10_bio->devs[0].addr + sect,
+ ok = sync_page_io(rdev,
+ addr,
+ s << 9,
+ bio->bi_io_vec[idx].bv_page,
+ READ, false);
+ if (ok) {
+ rdev = conf->mirrors[dw].rdev;
+ addr = r10_bio->devs[1].addr + sect;
+ ok = sync_page_io(rdev,
+ addr,
+ s << 9,
+ bio->bi_io_vec[idx].bv_page,
+ WRITE, false);
+ if (!ok) {
+ set_bit(WriteErrorSeen, &rdev->flags);
+ if (!test_and_set_bit(WantReplacement,
+ &rdev->flags))
+ set_bit(MD_RECOVERY_NEEDED,
+ &rdev->mddev->recovery);
+ }
+ }
+ if (!ok) {
+ /* We don't worry if we cannot set a bad block -
+ * it really is bad so there is no loss in not
+ * recording it yet
+ */
+ rdev_set_badblocks(rdev, addr, s, 0);
+
+ if (rdev != conf->mirrors[dw].rdev) {
+ /* need bad block on destination too */
+ struct md_rdev *rdev2 = conf->mirrors[dw].rdev;
+ addr = r10_bio->devs[1].addr + sect;
+ ok = rdev_set_badblocks(rdev2, addr, s, 0);
+ if (!ok) {
+ /* just abort the recovery */
+ printk(KERN_NOTICE
+ "md/raid10:%s: recovery aborted"
+ " due to read error\n",
+ mdname(mddev));
+
+ conf->mirrors[dw].recovery_disabled
+ = mddev->recovery_disabled;
+ set_bit(MD_RECOVERY_INTR,
+ &mddev->recovery);
+ break;
+ }
+ }
+ }
+
+ sectors -= s;
+ sect += s;
+ idx++;
+ }
+}
+
+static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
+{
+ struct r10conf *conf = mddev->private;
+ int d;
+ struct bio *wbio, *wbio2;
+
+ if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
+ fix_recovery_read_error(r10_bio);
+ end_sync_request(r10_bio);
+ return;
+ }
+
+ /*
+ * share the pages with the first bio
+ * and submit the write request
+ */
+ d = r10_bio->devs[1].devnum;
+ wbio = r10_bio->devs[1].bio;
+ wbio2 = r10_bio->devs[1].repl_bio;
+ /* Need to test wbio2->bi_end_io before we call
+ * generic_make_request as if the former is NULL,
+ * the latter is free to free wbio2.
+ */
+ if (wbio2 && !wbio2->bi_end_io)
+ wbio2 = NULL;
+ if (wbio->bi_end_io) {
+ atomic_inc(&conf->mirrors[d].rdev->nr_pending);
+ md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
+ generic_make_request(wbio);
+ }
+ if (wbio2) {
+ atomic_inc(&conf->mirrors[d].replacement->nr_pending);
+ md_sync_acct(conf->mirrors[d].replacement->bdev,
+ wbio2->bi_size >> 9);
+ generic_make_request(wbio2);
+ }
+}
+
+
+/*
+ * Used by fix_read_error() to decay the per rdev read_errors.
+ * We halve the read error count for every hour that has elapsed
+ * since the last recorded read error.
+ *
+ */
+static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)
+{
+ struct timespec cur_time_mon;
+ unsigned long hours_since_last;
+ unsigned int read_errors = atomic_read(&rdev->read_errors);
+
+ ktime_get_ts(&cur_time_mon);
+
+ if (rdev->last_read_error.tv_sec == 0 &&
+ rdev->last_read_error.tv_nsec == 0) {
+ /* first time we've seen a read error */
+ rdev->last_read_error = cur_time_mon;
+ return;
+ }
+
+ hours_since_last = (cur_time_mon.tv_sec -
+ rdev->last_read_error.tv_sec) / 3600;
+
+ rdev->last_read_error = cur_time_mon;
+
+ /*
+ * if hours_since_last is > the number of bits in read_errors
+ * just set read errors to 0. We do this to avoid
+ * overflowing the shift of read_errors by hours_since_last.
+ */
+ if (hours_since_last >= 8 * sizeof(read_errors))
+ atomic_set(&rdev->read_errors, 0);
+ else
+ atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
+}
+
+static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector,
+ int sectors, struct page *page, int rw)
+{
+ sector_t first_bad;
+ int bad_sectors;
+
+ if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors)
+ && (rw == READ || test_bit(WriteErrorSeen, &rdev->flags)))
+ return -1;
+ if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
+ /* success */
+ return 1;
+ if (rw == WRITE) {
+ set_bit(WriteErrorSeen, &rdev->flags);
+ if (!test_and_set_bit(WantReplacement, &rdev->flags))
+ set_bit(MD_RECOVERY_NEEDED,
+ &rdev->mddev->recovery);
+ }
+ /* need to record an error - either for the block or the device */
+ if (!rdev_set_badblocks(rdev, sector, sectors, 0))
+ md_error(rdev->mddev, rdev);
+ return 0;
+}
+
+/*
+ * This is a kernel thread which:
+ *
+ * 1. Retries failed read operations on working mirrors.
+ * 2. Updates the raid superblock when problems encounter.
+ * 3. Performs writes following reads for array synchronising.
+ */
+
+static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10bio *r10_bio)
+{
+ int sect = 0; /* Offset from r10_bio->sector */
+ int sectors = r10_bio->sectors;
+ struct md_rdev*rdev;
+ int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
+ int d = r10_bio->devs[r10_bio->read_slot].devnum;
+
+ /* still own a reference to this rdev, so it cannot
+ * have been cleared recently.
+ */
+ rdev = conf->mirrors[d].rdev;
+
+ if (test_bit(Faulty, &rdev->flags))
+ /* drive has already been failed, just ignore any
+ more fix_read_error() attempts */
+ return;
+
+ check_decay_read_errors(mddev, rdev);
+ atomic_inc(&rdev->read_errors);
+ if (atomic_read(&rdev->read_errors) > max_read_errors) {
+ char b[BDEVNAME_SIZE];
+ bdevname(rdev->bdev, b);
+
+ printk(KERN_NOTICE
+ "md/raid10:%s: %s: Raid device exceeded "
+ "read_error threshold [cur %d:max %d]\n",
+ mdname(mddev), b,
+ atomic_read(&rdev->read_errors), max_read_errors);
+ printk(KERN_NOTICE
+ "md/raid10:%s: %s: Failing raid device\n",
+ mdname(mddev), b);
+ md_error(mddev, conf->mirrors[d].rdev);
+ r10_bio->devs[r10_bio->read_slot].bio = IO_BLOCKED;
+ return;
+ }
+
+ while(sectors) {
+ int s = sectors;
+ int sl = r10_bio->read_slot;
+ int success = 0;
+ int start;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+
+ rcu_read_lock();
+ do {
+ sector_t first_bad;
+ int bad_sectors;
+
+ d = r10_bio->devs[sl].devnum;
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (rdev &&
+ !test_bit(Unmerged, &rdev->flags) &&
+ test_bit(In_sync, &rdev->flags) &&
+ is_badblock(rdev, r10_bio->devs[sl].addr + sect, s,
+ &first_bad, &bad_sectors) == 0) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ success = sync_page_io(rdev,
+ r10_bio->devs[sl].addr +
+ sect,
+ s<<9,
+ conf->tmppage, READ, false);
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ if (success)
+ break;
+ }
+ sl++;
+ if (sl == conf->copies)
+ sl = 0;
+ } while (!success && sl != r10_bio->read_slot);
+ rcu_read_unlock();
+
+ if (!success) {
+ /* Cannot read from anywhere, just mark the block
+ * as bad on the first device to discourage future
+ * reads.
+ */
+ int dn = r10_bio->devs[r10_bio->read_slot].devnum;
+ rdev = conf->mirrors[dn].rdev;
+
+ if (!rdev_set_badblocks(
+ rdev,
+ r10_bio->devs[r10_bio->read_slot].addr
+ + sect,
+ s, 0)) {
+ md_error(mddev, rdev);
+ r10_bio->devs[r10_bio->read_slot].bio
+ = IO_BLOCKED;
+ }
+ break;
+ }
+
+ start = sl;
+ /* write it back and re-read */
+ rcu_read_lock();
+ while (sl != r10_bio->read_slot) {
+ char b[BDEVNAME_SIZE];
+
+ if (sl==0)
+ sl = conf->copies;
+ sl--;
+ d = r10_bio->devs[sl].devnum;
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (!rdev ||
+ test_bit(Unmerged, &rdev->flags) ||
+ !test_bit(In_sync, &rdev->flags))
+ continue;
+
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ if (r10_sync_page_io(rdev,
+ r10_bio->devs[sl].addr +
+ sect,
+ s, conf->tmppage, WRITE)
+ == 0) {
+ /* Well, this device is dead */
+ printk(KERN_NOTICE
+ "md/raid10:%s: read correction "
+ "write failed"
+ " (%d sectors at %llu on %s)\n",
+ mdname(mddev), s,
+ (unsigned long long)(
+ sect + rdev->data_offset),
+ bdevname(rdev->bdev, b));
+ printk(KERN_NOTICE "md/raid10:%s: %s: failing "
+ "drive\n",
+ mdname(mddev),
+ bdevname(rdev->bdev, b));
+ }
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ }
+ sl = start;
+ while (sl != r10_bio->read_slot) {
+ char b[BDEVNAME_SIZE];
+
+ if (sl==0)
+ sl = conf->copies;
+ sl--;
+ d = r10_bio->devs[sl].devnum;
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (!rdev ||
+ !test_bit(In_sync, &rdev->flags))
+ continue;
+
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ switch (r10_sync_page_io(rdev,
+ r10_bio->devs[sl].addr +
+ sect,
+ s, conf->tmppage,
+ READ)) {
+ case 0:
+ /* Well, this device is dead */
+ printk(KERN_NOTICE
+ "md/raid10:%s: unable to read back "
+ "corrected sectors"
+ " (%d sectors at %llu on %s)\n",
+ mdname(mddev), s,
+ (unsigned long long)(
+ sect + rdev->data_offset),
+ bdevname(rdev->bdev, b));
+ printk(KERN_NOTICE "md/raid10:%s: %s: failing "
+ "drive\n",
+ mdname(mddev),
+ bdevname(rdev->bdev, b));
+ break;
+ case 1:
+ printk(KERN_INFO
+ "md/raid10:%s: read error corrected"
+ " (%d sectors at %llu on %s)\n",
+ mdname(mddev), s,
+ (unsigned long long)(
+ sect + rdev->data_offset),
+ bdevname(rdev->bdev, b));
+ atomic_add(s, &rdev->corrected_errors);
+ }
+
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ }
+ rcu_read_unlock();
+
+ sectors -= s;
+ sect += s;
+ }
+}
+
+static void bi_complete(struct bio *bio, int error)
+{
+ complete((struct completion *)bio->bi_private);
+}
+
+static int submit_bio_wait(int rw, struct bio *bio)
+{
+ struct completion event;
+ rw |= REQ_SYNC;
+
+ init_completion(&event);
+ bio->bi_private = &event;
+ bio->bi_end_io = bi_complete;
+ submit_bio(rw, bio);
+ wait_for_completion(&event);
+
+ return test_bit(BIO_UPTODATE, &bio->bi_flags);
+}
+
+static int narrow_write_error(struct r10bio *r10_bio, int i)
+{
+ struct bio *bio = r10_bio->master_bio;
+ struct mddev *mddev = r10_bio->mddev;
+ struct r10conf *conf = mddev->private;
+ struct md_rdev *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev;
+ /* bio has the data to be written to slot 'i' where
+ * we just recently had a write error.
+ * We repeatedly clone the bio and trim down to one block,
+ * then try the write. Where the write fails we record
+ * a bad block.
+ * It is conceivable that the bio doesn't exactly align with
+ * blocks. We must handle this.
+ *
+ * We currently own a reference to the rdev.
+ */
+
+ int block_sectors;
+ sector_t sector;
+ int sectors;
+ int sect_to_write = r10_bio->sectors;
+ int ok = 1;
+
+ if (rdev->badblocks.shift < 0)
+ return 0;
+
+ block_sectors = 1 << rdev->badblocks.shift;
+ sector = r10_bio->sector;
+ sectors = ((r10_bio->sector + block_sectors)
+ & ~(sector_t)(block_sectors - 1))
+ - sector;
+
+ while (sect_to_write) {
+ struct bio *wbio;
+ if (sectors > sect_to_write)
+ sectors = sect_to_write;
+ /* Write at 'sector' for 'sectors' */
+ wbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(wbio, sector - bio->bi_sector, sectors);
+ wbio->bi_sector = (r10_bio->devs[i].addr+
+ rdev->data_offset+
+ (sector - r10_bio->sector));
+ wbio->bi_bdev = rdev->bdev;
+ if (submit_bio_wait(WRITE, wbio) == 0)
+ /* Failure! */
+ ok = rdev_set_badblocks(rdev, sector,
+ sectors, 0)
+ && ok;
+
+ bio_put(wbio);
+ sect_to_write -= sectors;
+ sector += sectors;
+ sectors = block_sectors;
+ }
+ return ok;
+}
+
+static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
+{
+ int slot = r10_bio->read_slot;
+ struct bio *bio;
+ struct r10conf *conf = mddev->private;
+ struct md_rdev *rdev = r10_bio->devs[slot].rdev;
+ char b[BDEVNAME_SIZE];
+ unsigned long do_sync;
+ int max_sectors;
+
+ /* we got a read error. Maybe the drive is bad. Maybe just
+ * the block and we can fix it.
+ * We freeze all other IO, and try reading the block from
+ * other devices. When we find one, we re-write
+ * and check it that fixes the read error.
+ * This is all done synchronously while the array is
+ * frozen.
+ */
+ bio = r10_bio->devs[slot].bio;
+ bdevname(bio->bi_bdev, b);
+ bio_put(bio);
+ r10_bio->devs[slot].bio = NULL;
+
+ if (mddev->ro == 0) {
+ freeze_array(conf, 1);
+ fix_read_error(conf, mddev, r10_bio);
+ unfreeze_array(conf);
+ } else
+ r10_bio->devs[slot].bio = IO_BLOCKED;
+
+ rdev_dec_pending(rdev, mddev);
+
+read_more:
+ rdev = read_balance(conf, r10_bio, &max_sectors);
+ if (rdev == NULL) {
+ printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O"
+ " read error for block %llu\n",
+ mdname(mddev), b,
+ (unsigned long long)r10_bio->sector);
+ raid_end_bio_io(r10_bio);
+ return;
+ }
+
+ do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC);
+ slot = r10_bio->read_slot;
+ printk_ratelimited(
+ KERN_ERR
+ "md/raid10:%s: %s: redirecting "
+ "sector %llu to another mirror\n",
+ mdname(mddev),
+ bdevname(rdev->bdev, b),
+ (unsigned long long)r10_bio->sector);
+ bio = bio_clone_mddev(r10_bio->master_bio,
+ GFP_NOIO, mddev);
+ md_trim_bio(bio,
+ r10_bio->sector - bio->bi_sector,
+ max_sectors);
+ r10_bio->devs[slot].bio = bio;
+ r10_bio->devs[slot].rdev = rdev;
+ bio->bi_sector = r10_bio->devs[slot].addr
+ + rdev->data_offset;
+ bio->bi_bdev = rdev->bdev;
+ bio->bi_rw = READ | do_sync;
+ bio->bi_private = r10_bio;
+ bio->bi_end_io = raid10_end_read_request;
+ if (max_sectors < r10_bio->sectors) {
+ /* Drat - have to split this up more */
+ struct bio *mbio = r10_bio->master_bio;
+ int sectors_handled =
+ r10_bio->sector + max_sectors
+ - mbio->bi_sector;
+ r10_bio->sectors = max_sectors;
+ spin_lock_irq(&conf->device_lock);
+ if (mbio->bi_phys_segments == 0)
+ mbio->bi_phys_segments = 2;
+ else
+ mbio->bi_phys_segments++;
+ spin_unlock_irq(&conf->device_lock);
+ generic_make_request(bio);
+
+ r10_bio = mempool_alloc(conf->r10bio_pool,
+ GFP_NOIO);
+ r10_bio->master_bio = mbio;
+ r10_bio->sectors = (mbio->bi_size >> 9)
+ - sectors_handled;
+ r10_bio->state = 0;
+ set_bit(R10BIO_ReadError,
+ &r10_bio->state);
+ r10_bio->mddev = mddev;
+ r10_bio->sector = mbio->bi_sector
+ + sectors_handled;
+
+ goto read_more;
+ } else
+ generic_make_request(bio);
+}
+
+static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
+{
+ /* Some sort of write request has finished and it
+ * succeeded in writing where we thought there was a
+ * bad block. So forget the bad block.
+ * Or possibly if failed and we need to record
+ * a bad block.
+ */
+ int m;
+ struct md_rdev *rdev;
+
+ if (test_bit(R10BIO_IsSync, &r10_bio->state) ||
+ test_bit(R10BIO_IsRecover, &r10_bio->state)) {
+ for (m = 0; m < conf->copies; m++) {
+ int dev = r10_bio->devs[m].devnum;
+ rdev = conf->mirrors[dev].rdev;
+ if (r10_bio->devs[m].bio == NULL)
+ continue;
+ if (test_bit(BIO_UPTODATE,
+ &r10_bio->devs[m].bio->bi_flags)) {
+ rdev_clear_badblocks(
+ rdev,
+ r10_bio->devs[m].addr,
+ r10_bio->sectors);
+ } else {
+ if (!rdev_set_badblocks(
+ rdev,
+ r10_bio->devs[m].addr,
+ r10_bio->sectors, 0))
+ md_error(conf->mddev, rdev);
+ }
+ rdev = conf->mirrors[dev].replacement;
+ if (r10_bio->devs[m].repl_bio == NULL)
+ continue;
+ if (test_bit(BIO_UPTODATE,
+ &r10_bio->devs[m].repl_bio->bi_flags)) {
+ rdev_clear_badblocks(
+ rdev,
+ r10_bio->devs[m].addr,
+ r10_bio->sectors);
+ } else {
+ if (!rdev_set_badblocks(
+ rdev,
+ r10_bio->devs[m].addr,
+ r10_bio->sectors, 0))
+ md_error(conf->mddev, rdev);
+ }
+ }
+ put_buf(r10_bio);
+ } else {
+ for (m = 0; m < conf->copies; m++) {
+ int dev = r10_bio->devs[m].devnum;
+ struct bio *bio = r10_bio->devs[m].bio;
+ rdev = conf->mirrors[dev].rdev;
+ if (bio == IO_MADE_GOOD) {
+ rdev_clear_badblocks(
+ rdev,
+ r10_bio->devs[m].addr,
+ r10_bio->sectors);
+ rdev_dec_pending(rdev, conf->mddev);
+ } else if (bio != NULL &&
+ !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
+ if (!narrow_write_error(r10_bio, m)) {
+ md_error(conf->mddev, rdev);
+ set_bit(R10BIO_Degraded,
+ &r10_bio->state);
+ }
+ rdev_dec_pending(rdev, conf->mddev);
+ }
+ bio = r10_bio->devs[m].repl_bio;
+ rdev = conf->mirrors[dev].replacement;
+ if (rdev && bio == IO_MADE_GOOD) {
+ rdev_clear_badblocks(
+ rdev,
+ r10_bio->devs[m].addr,
+ r10_bio->sectors);
+ rdev_dec_pending(rdev, conf->mddev);
+ }
+ }
+ if (test_bit(R10BIO_WriteError,
+ &r10_bio->state))
+ close_write(r10_bio);
+ raid_end_bio_io(r10_bio);
+ }
+}
+
+static void raid10d(struct mddev *mddev)
+{
+ struct r10bio *r10_bio;
+ unsigned long flags;
+ struct r10conf *conf = mddev->private;
+ struct list_head *head = &conf->retry_list;
+ struct blk_plug plug;
+
+ md_check_recovery(mddev);
+
+ blk_start_plug(&plug);
+ for (;;) {
+
+ flush_pending_writes(conf);
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (list_empty(head)) {
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ break;
+ }
+ r10_bio = list_entry(head->prev, struct r10bio, retry_list);
+ list_del(head->prev);
+ conf->nr_queued--;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ mddev = r10_bio->mddev;
+ conf = mddev->private;
+ if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
+ test_bit(R10BIO_WriteError, &r10_bio->state))
+ handle_write_completed(conf, r10_bio);
+ else if (test_bit(R10BIO_IsSync, &r10_bio->state))
+ sync_request_write(mddev, r10_bio);
+ else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
+ recovery_request_write(mddev, r10_bio);
+ else if (test_bit(R10BIO_ReadError, &r10_bio->state))
+ handle_read_error(mddev, r10_bio);
+ else {
+ /* just a partial read to be scheduled from a
+ * separate context
+ */
+ int slot = r10_bio->read_slot;
+ generic_make_request(r10_bio->devs[slot].bio);
+ }
+
+ cond_resched();
+ if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
+ md_check_recovery(mddev);
+ }
+ blk_finish_plug(&plug);
+}
+
+
+static int init_resync(struct r10conf *conf)
+{
+ int buffs;
+ int i;
+
+ buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
+ BUG_ON(conf->r10buf_pool);
+ conf->have_replacement = 0;
+ for (i = 0; i < conf->raid_disks; i++)
+ if (conf->mirrors[i].replacement)
+ conf->have_replacement = 1;
+ conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
+ if (!conf->r10buf_pool)
+ return -ENOMEM;
+ conf->next_resync = 0;
+ return 0;
+}
+
+/*
+ * perform a "sync" on one "block"
+ *
+ * We need to make sure that no normal I/O request - particularly write
+ * requests - conflict with active sync requests.
+ *
+ * This is achieved by tracking pending requests and a 'barrier' concept
+ * that can be installed to exclude normal IO requests.
+ *
+ * Resync and recovery are handled very differently.
+ * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
+ *
+ * For resync, we iterate over virtual addresses, read all copies,
+ * and update if there are differences. If only one copy is live,
+ * skip it.
+ * For recovery, we iterate over physical addresses, read a good
+ * value for each non-in_sync drive, and over-write.
+ *
+ * So, for recovery we may have several outstanding complex requests for a
+ * given address, one for each out-of-sync device. We model this by allocating
+ * a number of r10_bio structures, one for each out-of-sync device.
+ * As we setup these structures, we collect all bio's together into a list
+ * which we then process collectively to add pages, and then process again
+ * to pass to generic_make_request.
+ *
+ * The r10_bio structures are linked using a borrowed master_bio pointer.
+ * This link is counted in ->remaining. When the r10_bio that points to NULL
+ * has its remaining count decremented to 0, the whole complex operation
+ * is complete.
+ *
+ */
+
+static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
+ int *skipped, int go_faster)
+{
+ struct r10conf *conf = mddev->private;
+ struct r10bio *r10_bio;
+ struct bio *biolist = NULL, *bio;
+ sector_t max_sector, nr_sectors;
+ int i;
+ int max_sync;
+ sector_t sync_blocks;
+ sector_t sectors_skipped = 0;
+ int chunks_skipped = 0;
+
+ if (!conf->r10buf_pool)
+ if (init_resync(conf))
+ return 0;
+
+ skipped:
+ max_sector = mddev->dev_sectors;
+ if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
+ max_sector = mddev->resync_max_sectors;
+ if (sector_nr >= max_sector) {
+ /* If we aborted, we need to abort the
+ * sync on the 'current' bitmap chucks (there can
+ * be several when recovering multiple devices).
+ * as we may have started syncing it but not finished.
+ * We can find the current address in
+ * mddev->curr_resync, but for recovery,
+ * we need to convert that to several
+ * virtual addresses.
+ */
+ if (mddev->curr_resync < max_sector) { /* aborted */
+ if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
+ bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
+ &sync_blocks, 1);
+ else for (i=0; i<conf->raid_disks; i++) {
+ sector_t sect =
+ raid10_find_virt(conf, mddev->curr_resync, i);
+ bitmap_end_sync(mddev->bitmap, sect,
+ &sync_blocks, 1);
+ }
+ } else {
+ /* completed sync */
+ if ((!mddev->bitmap || conf->fullsync)
+ && conf->have_replacement
+ && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
+ /* Completed a full sync so the replacements
+ * are now fully recovered.
+ */
+ for (i = 0; i < conf->raid_disks; i++)
+ if (conf->mirrors[i].replacement)
+ conf->mirrors[i].replacement
+ ->recovery_offset
+ = MaxSector;
+ }
+ conf->fullsync = 0;
+ }
+ bitmap_close_sync(mddev->bitmap);
+ close_sync(conf);
+ *skipped = 1;
+ return sectors_skipped;
+ }
+ if (chunks_skipped >= conf->raid_disks) {
+ /* if there has been nothing to do on any drive,
+ * then there is nothing to do at all..
+ */
+ *skipped = 1;
+ return (max_sector - sector_nr) + sectors_skipped;
+ }
+
+ if (max_sector > mddev->resync_max)
+ max_sector = mddev->resync_max; /* Don't do IO beyond here */
+
+ /* make sure whole request will fit in a chunk - if chunks
+ * are meaningful
+ */
+ if (conf->near_copies < conf->raid_disks &&
+ max_sector > (sector_nr | conf->chunk_mask))
+ max_sector = (sector_nr | conf->chunk_mask) + 1;
+ /*
+ * If there is non-resync activity waiting for us then
+ * put in a delay to throttle resync.
+ */
+ if (!go_faster && conf->nr_waiting)
+ msleep_interruptible(1000);
+
+ /* Again, very different code for resync and recovery.
+ * Both must result in an r10bio with a list of bios that
+ * have bi_end_io, bi_sector, bi_bdev set,
+ * and bi_private set to the r10bio.
+ * For recovery, we may actually create several r10bios
+ * with 2 bios in each, that correspond to the bios in the main one.
+ * In this case, the subordinate r10bios link back through a
+ * borrowed master_bio pointer, and the counter in the master
+ * includes a ref from each subordinate.
+ */
+ /* First, we decide what to do and set ->bi_end_io
+ * To end_sync_read if we want to read, and
+ * end_sync_write if we will want to write.
+ */
+
+ max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
+ if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
+ /* recovery... the complicated one */
+ int j;
+ r10_bio = NULL;
+
+ for (i=0 ; i<conf->raid_disks; i++) {
+ int still_degraded;
+ struct r10bio *rb2;
+ sector_t sect;
+ int must_sync;
+ int any_working;
+ struct mirror_info *mirror = &conf->mirrors[i];
+
+ if ((mirror->rdev == NULL ||
+ test_bit(In_sync, &mirror->rdev->flags))
+ &&
+ (mirror->replacement == NULL ||
+ test_bit(Faulty,
+ &mirror->replacement->flags)))
+ continue;
+
+ still_degraded = 0;
+ /* want to reconstruct this device */
+ rb2 = r10_bio;
+ sect = raid10_find_virt(conf, sector_nr, i);
+ if (sect >= mddev->resync_max_sectors) {
+ /* last stripe is not complete - don't
+ * try to recover this sector.
+ */
+ continue;
+ }
+ /* Unless we are doing a full sync, or a replacement
+ * we only need to recover the block if it is set in
+ * the bitmap
+ */
+ must_sync = bitmap_start_sync(mddev->bitmap, sect,
+ &sync_blocks, 1);
+ if (sync_blocks < max_sync)
+ max_sync = sync_blocks;
+ if (!must_sync &&
+ mirror->replacement == NULL &&
+ !conf->fullsync) {
+ /* yep, skip the sync_blocks here, but don't assume
+ * that there will never be anything to do here
+ */
+ chunks_skipped = -1;
+ continue;
+ }
+
+ r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
+ raise_barrier(conf, rb2 != NULL);
+ atomic_set(&r10_bio->remaining, 0);
+
+ r10_bio->master_bio = (struct bio*)rb2;
+ if (rb2)
+ atomic_inc(&rb2->remaining);
+ r10_bio->mddev = mddev;
+ set_bit(R10BIO_IsRecover, &r10_bio->state);
+ r10_bio->sector = sect;
+
+ raid10_find_phys(conf, r10_bio);
+
+ /* Need to check if the array will still be
+ * degraded
+ */
+ for (j=0; j<conf->raid_disks; j++)
+ if (conf->mirrors[j].rdev == NULL ||
+ test_bit(Faulty, &conf->mirrors[j].rdev->flags)) {
+ still_degraded = 1;
+ break;
+ }
+
+ must_sync = bitmap_start_sync(mddev->bitmap, sect,
+ &sync_blocks, still_degraded);
+
+ any_working = 0;
+ for (j=0; j<conf->copies;j++) {
+ int k;
+ int d = r10_bio->devs[j].devnum;
+ sector_t from_addr, to_addr;
+ struct md_rdev *rdev;
+ sector_t sector, first_bad;
+ int bad_sectors;
+ if (!conf->mirrors[d].rdev ||
+ !test_bit(In_sync, &conf->mirrors[d].rdev->flags))
+ continue;
+ /* This is where we read from */
+ any_working = 1;
+ rdev = conf->mirrors[d].rdev;
+ sector = r10_bio->devs[j].addr;
+
+ if (is_badblock(rdev, sector, max_sync,
+ &first_bad, &bad_sectors)) {
+ if (first_bad > sector)
+ max_sync = first_bad - sector;
+ else {
+ bad_sectors -= (sector
+ - first_bad);
+ if (max_sync > bad_sectors)
+ max_sync = bad_sectors;
+ continue;
+ }
+ }
+ bio = r10_bio->devs[0].bio;
+ bio->bi_next = biolist;
+ biolist = bio;
+ bio->bi_private = r10_bio;
+ bio->bi_end_io = end_sync_read;
+ bio->bi_rw = READ;
+ from_addr = r10_bio->devs[j].addr;
+ bio->bi_sector = from_addr + rdev->data_offset;
+ bio->bi_bdev = rdev->bdev;
+ atomic_inc(&rdev->nr_pending);
+ /* and we write to 'i' (if not in_sync) */
+
+ for (k=0; k<conf->copies; k++)
+ if (r10_bio->devs[k].devnum == i)
+ break;
+ BUG_ON(k == conf->copies);
+ to_addr = r10_bio->devs[k].addr;
+ r10_bio->devs[0].devnum = d;
+ r10_bio->devs[0].addr = from_addr;
+ r10_bio->devs[1].devnum = i;
+ r10_bio->devs[1].addr = to_addr;
+
+ rdev = mirror->rdev;
+ if (!test_bit(In_sync, &rdev->flags)) {
+ bio = r10_bio->devs[1].bio;
+ bio->bi_next = biolist;
+ biolist = bio;
+ bio->bi_private = r10_bio;
+ bio->bi_end_io = end_sync_write;
+ bio->bi_rw = WRITE;
+ bio->bi_sector = to_addr
+ + rdev->data_offset;
+ bio->bi_bdev = rdev->bdev;
+ atomic_inc(&r10_bio->remaining);
+ } else
+ r10_bio->devs[1].bio->bi_end_io = NULL;
+
+ /* and maybe write to replacement */
+ bio = r10_bio->devs[1].repl_bio;
+ if (bio)
+ bio->bi_end_io = NULL;
+ rdev = mirror->replacement;
+ /* Note: if rdev != NULL, then bio
+ * cannot be NULL as r10buf_pool_alloc will
+ * have allocated it.
+ * So the second test here is pointless.
+ * But it keeps semantic-checkers happy, and
+ * this comment keeps human reviewers
+ * happy.
+ */
+ if (rdev == NULL || bio == NULL ||
+ test_bit(Faulty, &rdev->flags))
+ break;
+ bio->bi_next = biolist;
+ biolist = bio;
+ bio->bi_private = r10_bio;
+ bio->bi_end_io = end_sync_write;
+ bio->bi_rw = WRITE;
+ bio->bi_sector = to_addr + rdev->data_offset;
+ bio->bi_bdev = rdev->bdev;
+ atomic_inc(&r10_bio->remaining);
+ break;
+ }
+ if (j == conf->copies) {
+ /* Cannot recover, so abort the recovery or
+ * record a bad block */
+ if (any_working) {
+ /* problem is that there are bad blocks
+ * on other device(s)
+ */
+ int k;
+ for (k = 0; k < conf->copies; k++)
+ if (r10_bio->devs[k].devnum == i)
+ break;
+ if (!test_bit(In_sync,
+ &mirror->rdev->flags)
+ && !rdev_set_badblocks(
+ mirror->rdev,
+ r10_bio->devs[k].addr,
+ max_sync, 0))
+ any_working = 0;
+ if (mirror->replacement &&
+ !rdev_set_badblocks(
+ mirror->replacement,
+ r10_bio->devs[k].addr,
+ max_sync, 0))
+ any_working = 0;
+ }
+ if (!any_working) {
+ if (!test_and_set_bit(MD_RECOVERY_INTR,
+ &mddev->recovery))
+ printk(KERN_INFO "md/raid10:%s: insufficient "
+ "working devices for recovery.\n",
+ mdname(mddev));
+ mirror->recovery_disabled
+ = mddev->recovery_disabled;
+ }
+ put_buf(r10_bio);
+ if (rb2)
+ atomic_dec(&rb2->remaining);
+ r10_bio = rb2;
+ break;
+ }
+ }
+ if (biolist == NULL) {
+ while (r10_bio) {
+ struct r10bio *rb2 = r10_bio;
+ r10_bio = (struct r10bio*) rb2->master_bio;
+ rb2->master_bio = NULL;
+ put_buf(rb2);
+ }
+ goto giveup;
+ }
+ } else {
+ /* resync. Schedule a read for every block at this virt offset */
+ int count = 0;
+
+ bitmap_cond_end_sync(mddev->bitmap, sector_nr);
+
+ if (!bitmap_start_sync(mddev->bitmap, sector_nr,
+ &sync_blocks, mddev->degraded) &&
+ !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED,
+ &mddev->recovery)) {
+ /* We can skip this block */
+ *skipped = 1;
+ return sync_blocks + sectors_skipped;
+ }
+ if (sync_blocks < max_sync)
+ max_sync = sync_blocks;
+ r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
+
+ r10_bio->mddev = mddev;
+ atomic_set(&r10_bio->remaining, 0);
+ raise_barrier(conf, 0);
+ conf->next_resync = sector_nr;
+
+ r10_bio->master_bio = NULL;
+ r10_bio->sector = sector_nr;
+ set_bit(R10BIO_IsSync, &r10_bio->state);
+ raid10_find_phys(conf, r10_bio);
+ r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1;
+
+ for (i=0; i<conf->copies; i++) {
+ int d = r10_bio->devs[i].devnum;
+ sector_t first_bad, sector;
+ int bad_sectors;
+
+ if (r10_bio->devs[i].repl_bio)
+ r10_bio->devs[i].repl_bio->bi_end_io = NULL;
+
+ bio = r10_bio->devs[i].bio;
+ bio->bi_end_io = NULL;
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ if (conf->mirrors[d].rdev == NULL ||
+ test_bit(Faulty, &conf->mirrors[d].rdev->flags))
+ continue;
+ sector = r10_bio->devs[i].addr;
+ if (is_badblock(conf->mirrors[d].rdev,
+ sector, max_sync,
+ &first_bad, &bad_sectors)) {
+ if (first_bad > sector)
+ max_sync = first_bad - sector;
+ else {
+ bad_sectors -= (sector - first_bad);
+ if (max_sync > bad_sectors)
+ max_sync = bad_sectors;
+ continue;
+ }
+ }
+ atomic_inc(&conf->mirrors[d].rdev->nr_pending);
+ atomic_inc(&r10_bio->remaining);
+ bio->bi_next = biolist;
+ biolist = bio;
+ bio->bi_private = r10_bio;
+ bio->bi_end_io = end_sync_read;
+ bio->bi_rw = READ;
+ bio->bi_sector = sector +
+ conf->mirrors[d].rdev->data_offset;
+ bio->bi_bdev = conf->mirrors[d].rdev->bdev;
+ count++;
+
+ if (conf->mirrors[d].replacement == NULL ||
+ test_bit(Faulty,
+ &conf->mirrors[d].replacement->flags))
+ continue;
+
+ /* Need to set up for writing to the replacement */
+ bio = r10_bio->devs[i].repl_bio;
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+
+ sector = r10_bio->devs[i].addr;
+ atomic_inc(&conf->mirrors[d].rdev->nr_pending);
+ bio->bi_next = biolist;
+ biolist = bio;
+ bio->bi_private = r10_bio;
+ bio->bi_end_io = end_sync_write;
+ bio->bi_rw = WRITE;
+ bio->bi_sector = sector +
+ conf->mirrors[d].replacement->data_offset;
+ bio->bi_bdev = conf->mirrors[d].replacement->bdev;
+ count++;
+ }
+
+ if (count < 2) {
+ for (i=0; i<conf->copies; i++) {
+ int d = r10_bio->devs[i].devnum;
+ if (r10_bio->devs[i].bio->bi_end_io)
+ rdev_dec_pending(conf->mirrors[d].rdev,
+ mddev);
+ if (r10_bio->devs[i].repl_bio &&
+ r10_bio->devs[i].repl_bio->bi_end_io)
+ rdev_dec_pending(
+ conf->mirrors[d].replacement,
+ mddev);
+ }
+ put_buf(r10_bio);
+ biolist = NULL;
+ goto giveup;
+ }
+ }
+
+ for (bio = biolist; bio ; bio=bio->bi_next) {
+
+ bio->bi_flags &= ~(BIO_POOL_MASK - 1);
+ if (bio->bi_end_io)
+ bio->bi_flags |= 1 << BIO_UPTODATE;
+ bio->bi_vcnt = 0;
+ bio->bi_idx = 0;
+ bio->bi_phys_segments = 0;
+ bio->bi_size = 0;
+ }
+
+ nr_sectors = 0;
+ if (sector_nr + max_sync < max_sector)
+ max_sector = sector_nr + max_sync;
+ do {
+ struct page *page;
+ int len = PAGE_SIZE;
+ if (sector_nr + (len>>9) > max_sector)
+ len = (max_sector - sector_nr) << 9;
+ if (len == 0)
+ break;
+ for (bio= biolist ; bio ; bio=bio->bi_next) {
+ struct bio *bio2;
+ page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
+ if (bio_add_page(bio, page, len, 0))
+ continue;
+
+ /* stop here */
+ bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
+ for (bio2 = biolist;
+ bio2 && bio2 != bio;
+ bio2 = bio2->bi_next) {
+ /* remove last page from this bio */
+ bio2->bi_vcnt--;
+ bio2->bi_size -= len;
+ bio2->bi_flags &= ~(1<< BIO_SEG_VALID);
+ }
+ goto bio_full;
+ }
+ nr_sectors += len>>9;
+ sector_nr += len>>9;
+ } while (biolist->bi_vcnt < RESYNC_PAGES);
+ bio_full:
+ r10_bio->sectors = nr_sectors;
+
+ while (biolist) {
+ bio = biolist;
+ biolist = biolist->bi_next;
+
+ bio->bi_next = NULL;
+ r10_bio = bio->bi_private;
+ r10_bio->sectors = nr_sectors;
+
+ if (bio->bi_end_io == end_sync_read) {
+ md_sync_acct(bio->bi_bdev, nr_sectors);
+ generic_make_request(bio);
+ }
+ }
+
+ if (sectors_skipped)
+ /* pretend they weren't skipped, it makes
+ * no important difference in this case
+ */
+ md_done_sync(mddev, sectors_skipped, 1);
+
+ return sectors_skipped + nr_sectors;
+ giveup:
+ /* There is nowhere to write, so all non-sync
+ * drives must be failed or in resync, all drives
+ * have a bad block, so try the next chunk...
+ */
+ if (sector_nr + max_sync < max_sector)
+ max_sector = sector_nr + max_sync;
+
+ sectors_skipped += (max_sector - sector_nr);
+ chunks_skipped ++;
+ sector_nr = max_sector;
+ goto skipped;
+}
+
+static sector_t
+raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks)
+{
+ sector_t size;
+ struct r10conf *conf = mddev->private;
+
+ if (!raid_disks)
+ raid_disks = conf->raid_disks;
+ if (!sectors)
+ sectors = conf->dev_sectors;
+
+ size = sectors >> conf->chunk_shift;
+ sector_div(size, conf->far_copies);
+ size = size * raid_disks;
+ sector_div(size, conf->near_copies);
+
+ return size << conf->chunk_shift;
+}
+
+static void calc_sectors(struct r10conf *conf, sector_t size)
+{
+ /* Calculate the number of sectors-per-device that will
+ * actually be used, and set conf->dev_sectors and
+ * conf->stride
+ */
+
+ size = size >> conf->chunk_shift;
+ sector_div(size, conf->far_copies);
+ size = size * conf->raid_disks;
+ sector_div(size, conf->near_copies);
+ /* 'size' is now the number of chunks in the array */
+ /* calculate "used chunks per device" */
+ size = size * conf->copies;
+
+ /* We need to round up when dividing by raid_disks to
+ * get the stride size.
+ */
+ size = DIV_ROUND_UP_SECTOR_T(size, conf->raid_disks);
+
+ conf->dev_sectors = size << conf->chunk_shift;
+
+ if (conf->far_offset)
+ conf->stride = 1 << conf->chunk_shift;
+ else {
+ sector_div(size, conf->far_copies);
+ conf->stride = size << conf->chunk_shift;
+ }
+}
+
+static struct r10conf *setup_conf(struct mddev *mddev)
+{
+ struct r10conf *conf = NULL;
+ int nc, fc, fo;
+ int err = -EINVAL;
+
+ if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) ||
+ !is_power_of_2(mddev->new_chunk_sectors)) {
+ printk(KERN_ERR "md/raid10:%s: chunk size must be "
+ "at least PAGE_SIZE(%ld) and be a power of 2.\n",
+ mdname(mddev), PAGE_SIZE);
+ goto out;
+ }
+
+ nc = mddev->new_layout & 255;
+ fc = (mddev->new_layout >> 8) & 255;
+ fo = mddev->new_layout & (1<<16);
+
+ if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
+ (mddev->new_layout >> 17)) {
+ printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
+ mdname(mddev), mddev->new_layout);
+ goto out;
+ }
+
+ err = -ENOMEM;
+ conf = kzalloc(sizeof(struct r10conf), GFP_KERNEL);
+ if (!conf)
+ goto out;
+
+ conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
+ GFP_KERNEL);
+ if (!conf->mirrors)
+ goto out;
+
+ conf->tmppage = alloc_page(GFP_KERNEL);
+ if (!conf->tmppage)
+ goto out;
+
+
+ conf->raid_disks = mddev->raid_disks;
+ conf->near_copies = nc;
+ conf->far_copies = fc;
+ conf->copies = nc*fc;
+ conf->far_offset = fo;
+ conf->chunk_mask = mddev->new_chunk_sectors - 1;
+ conf->chunk_shift = ffz(~mddev->new_chunk_sectors);
+
+ conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
+ r10bio_pool_free, conf);
+ if (!conf->r10bio_pool)
+ goto out;
+
+ calc_sectors(conf, mddev->dev_sectors);
+
+ spin_lock_init(&conf->device_lock);
+ INIT_LIST_HEAD(&conf->retry_list);
+
+ spin_lock_init(&conf->resync_lock);
+ init_waitqueue_head(&conf->wait_barrier);
+
+ conf->thread = md_register_thread(raid10d, mddev, NULL);
+ if (!conf->thread)
+ goto out;
+
+ conf->mddev = mddev;
+ return conf;
+
+ out:
+ printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n",
+ mdname(mddev));
+ if (conf) {
+ if (conf->r10bio_pool)
+ mempool_destroy(conf->r10bio_pool);
+ kfree(conf->mirrors);
+ safe_put_page(conf->tmppage);
+ kfree(conf);
+ }
+ return ERR_PTR(err);
+}
+
+static int run(struct mddev *mddev)
+{
+ struct r10conf *conf;
+ int i, disk_idx, chunk_size;
+ struct mirror_info *disk;
+ struct md_rdev *rdev;
+ sector_t size;
+
+ /*
+ * copy the already verified devices into our private RAID10
+ * bookkeeping area. [whatever we allocate in run(),
+ * should be freed in stop()]
+ */
+
+ if (mddev->private == NULL) {
+ conf = setup_conf(mddev);
+ if (IS_ERR(conf))
+ return PTR_ERR(conf);
+ mddev->private = conf;
+ }
+ conf = mddev->private;
+ if (!conf)
+ goto out;
+
+ mddev->thread = conf->thread;
+ conf->thread = NULL;
+
+ chunk_size = mddev->chunk_sectors << 9;
+ blk_queue_io_min(mddev->queue, chunk_size);
+ if (conf->raid_disks % conf->near_copies)
+ blk_queue_io_opt(mddev->queue, chunk_size * conf->raid_disks);
+ else
+ blk_queue_io_opt(mddev->queue, chunk_size *
+ (conf->raid_disks / conf->near_copies));
+
+ rdev_for_each(rdev, mddev) {
+ struct request_queue *q;
+ disk_idx = rdev->raid_disk;
+ if (disk_idx >= conf->raid_disks
+ || disk_idx < 0)
+ continue;
+ disk = conf->mirrors + disk_idx;
+
+ if (test_bit(Replacement, &rdev->flags)) {
+ if (disk->replacement)
+ goto out_free_conf;
+ disk->replacement = rdev;
+ } else {
+ if (disk->rdev)
+ goto out_free_conf;
+ disk->rdev = rdev;
+ }
+ q = bdev_get_queue(rdev->bdev);
+ if (q->merge_bvec_fn)
+ mddev->merge_check_needed = 1;
+
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+
+ disk->head_position = 0;
+ }
+ /* need to check that every block has at least one working mirror */
+ if (!enough(conf, -1)) {
+ printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",
+ mdname(mddev));
+ goto out_free_conf;
+ }
+
+ mddev->degraded = 0;
+ for (i = 0; i < conf->raid_disks; i++) {
+
+ disk = conf->mirrors + i;
+
+ if (!disk->rdev && disk->replacement) {
+ /* The replacement is all we have - use it */
+ disk->rdev = disk->replacement;
+ disk->replacement = NULL;
+ clear_bit(Replacement, &disk->rdev->flags);
+ }
+
+ if (!disk->rdev ||
+ !test_bit(In_sync, &disk->rdev->flags)) {
+ disk->head_position = 0;
+ mddev->degraded++;
+ if (disk->rdev)
+ conf->fullsync = 1;
+ }
+ disk->recovery_disabled = mddev->recovery_disabled - 1;
+ }
+
+ if (mddev->recovery_cp != MaxSector)
+ printk(KERN_NOTICE "md/raid10:%s: not clean"
+ " -- starting background reconstruction\n",
+ mdname(mddev));
+ printk(KERN_INFO
+ "md/raid10:%s: active with %d out of %d devices\n",
+ mdname(mddev), conf->raid_disks - mddev->degraded,
+ conf->raid_disks);
+ /*
+ * Ok, everything is just fine now
+ */
+ mddev->dev_sectors = conf->dev_sectors;
+ size = raid10_size(mddev, 0, 0);
+ md_set_array_sectors(mddev, size);
+ mddev->resync_max_sectors = size;
+
+ mddev->queue->backing_dev_info.congested_fn = raid10_congested;
+ mddev->queue->backing_dev_info.congested_data = mddev;
+
+ /* Calculate max read-ahead size.
+ * We need to readahead at least twice a whole stripe....
+ * maybe...
+ */
+ {
+ int stripe = conf->raid_disks *
+ ((mddev->chunk_sectors << 9) / PAGE_SIZE);
+ stripe /= conf->near_copies;
+ if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
+ mddev->queue->backing_dev_info.ra_pages = 2* stripe;
+ }
+
+ blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec);
+
+ if (md_integrity_register(mddev))
+ goto out_free_conf;
+
+ return 0;
+
+out_free_conf:
+ md_unregister_thread(&mddev->thread);
+ if (conf->r10bio_pool)
+ mempool_destroy(conf->r10bio_pool);
+ safe_put_page(conf->tmppage);
+ kfree(conf->mirrors);
+ kfree(conf);
+ mddev->private = NULL;
+out:
+ return -EIO;
+}
+
+static int stop(struct mddev *mddev)
+{
+ struct r10conf *conf = mddev->private;
+
+ raise_barrier(conf, 0);
+ lower_barrier(conf);
+
+ md_unregister_thread(&mddev->thread);
+ blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
+ if (conf->r10bio_pool)
+ mempool_destroy(conf->r10bio_pool);
+ kfree(conf->mirrors);
+ kfree(conf);
+ mddev->private = NULL;
+ return 0;
+}
+
+static void raid10_quiesce(struct mddev *mddev, int state)
+{
+ struct r10conf *conf = mddev->private;
+
+ switch(state) {
+ case 1:
+ raise_barrier(conf, 0);
+ break;
+ case 0:
+ lower_barrier(conf);
+ break;
+ }
+}
+
+static int raid10_resize(struct mddev *mddev, sector_t sectors)
+{
+ /* Resize of 'far' arrays is not supported.
+ * For 'near' and 'offset' arrays we can set the
+ * number of sectors used to be an appropriate multiple
+ * of the chunk size.
+ * For 'offset', this is far_copies*chunksize.
+ * For 'near' the multiplier is the LCM of
+ * near_copies and raid_disks.
+ * So if far_copies > 1 && !far_offset, fail.
+ * Else find LCM(raid_disks, near_copy)*far_copies and
+ * multiply by chunk_size. Then round to this number.
+ * This is mostly done by raid10_size()
+ */
+ struct r10conf *conf = mddev->private;
+ sector_t oldsize, size;
+
+ if (conf->far_copies > 1 && !conf->far_offset)
+ return -EINVAL;
+
+ oldsize = raid10_size(mddev, 0, 0);
+ size = raid10_size(mddev, sectors, 0);
+ md_set_array_sectors(mddev, size);
+ if (mddev->array_sectors > size)
+ return -EINVAL;
+ set_capacity(mddev->gendisk, mddev->array_sectors);
+ revalidate_disk(mddev->gendisk);
+ if (sectors > mddev->dev_sectors &&
+ mddev->recovery_cp > oldsize) {
+ mddev->recovery_cp = oldsize;
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ }
+ calc_sectors(conf, sectors);
+ mddev->dev_sectors = conf->dev_sectors;
+ mddev->resync_max_sectors = size;
+ return 0;
+}
+
+static void *raid10_takeover_raid0(struct mddev *mddev)
+{
+ struct md_rdev *rdev;
+ struct r10conf *conf;
+
+ if (mddev->degraded > 0) {
+ printk(KERN_ERR "md/raid10:%s: Error: degraded raid0!\n",
+ mdname(mddev));
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* Set new parameters */
+ mddev->new_level = 10;
+ /* new layout: far_copies = 1, near_copies = 2 */
+ mddev->new_layout = (1<<8) + 2;
+ mddev->new_chunk_sectors = mddev->chunk_sectors;
+ mddev->delta_disks = mddev->raid_disks;
+ mddev->raid_disks *= 2;
+ /* make sure it will be not marked as dirty */
+ mddev->recovery_cp = MaxSector;
+
+ conf = setup_conf(mddev);
+ if (!IS_ERR(conf)) {
+ rdev_for_each(rdev, mddev)
+ if (rdev->raid_disk >= 0)
+ rdev->new_raid_disk = rdev->raid_disk * 2;
+ conf->barrier = 1;
+ }
+
+ return conf;
+}
+
+static void *raid10_takeover(struct mddev *mddev)
+{
+ struct r0conf *raid0_conf;
+
+ /* raid10 can take over:
+ * raid0 - providing it has only two drives
+ */
+ if (mddev->level == 0) {
+ /* for raid0 takeover only one zone is supported */
+ raid0_conf = mddev->private;
+ if (raid0_conf->nr_strip_zones > 1) {
+ printk(KERN_ERR "md/raid10:%s: cannot takeover raid 0"
+ " with more than one zone.\n",
+ mdname(mddev));
+ return ERR_PTR(-EINVAL);
+ }
+ return raid10_takeover_raid0(mddev);
+ }
+ return ERR_PTR(-EINVAL);
+}
+
+static struct md_personality raid10_personality =
+{
+ .name = "raid10",
+ .level = 10,
+ .owner = THIS_MODULE,
+ .make_request = make_request,
+ .run = run,
+ .stop = stop,
+ .status = status,
+ .error_handler = error,
+ .hot_add_disk = raid10_add_disk,
+ .hot_remove_disk= raid10_remove_disk,
+ .spare_active = raid10_spare_active,
+ .sync_request = sync_request,
+ .quiesce = raid10_quiesce,
+ .size = raid10_size,
+ .resize = raid10_resize,
+ .takeover = raid10_takeover,
+};
+
+static int __init raid_init(void)
+{
+ return register_md_personality(&raid10_personality);
+}
+
+static void raid_exit(void)
+{
+ unregister_md_personality(&raid10_personality);
+}
+
+module_init(raid_init);
+module_exit(raid_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
+MODULE_ALIAS("md-personality-9"); /* RAID10 */
+MODULE_ALIAS("md-raid10");
+MODULE_ALIAS("md-level-10");
+
+module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);