[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/md/dm.c b/src/kernel/linux/v4.14/drivers/md/dm.c
new file mode 100644
index 0000000..6e741f1
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/md/dm.c
@@ -0,0 +1,3030 @@
+/*
+ * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm-core.h"
+#include "dm-rq.h"
+#include "dm-uevent.h"
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/signal.h>
+#include <linux/blkpg.h>
+#include <linux/bio.h>
+#include <linux/mempool.h>
+#include <linux/dax.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/uio.h>
+#include <linux/hdreg.h>
+#include <linux/delay.h>
+#include <linux/wait.h>
+#include <linux/pr.h>
+
+#define DM_MSG_PREFIX "core"
+
+/*
+ * Cookies are numeric values sent with CHANGE and REMOVE
+ * uevents while resuming, removing or renaming the device.
+ */
+#define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
+#define DM_COOKIE_LENGTH 24
+
+static const char *_name = DM_NAME;
+
+static unsigned int major = 0;
+static unsigned int _major = 0;
+
+static DEFINE_IDR(_minor_idr);
+
+static DEFINE_SPINLOCK(_minor_lock);
+
+static void do_deferred_remove(struct work_struct *w);
+
+static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
+
+static struct workqueue_struct *deferred_remove_workqueue;
+
+atomic_t dm_global_event_nr = ATOMIC_INIT(0);
+DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq);
+
+void dm_issue_global_event(void)
+{
+ atomic_inc(&dm_global_event_nr);
+ wake_up(&dm_global_eventq);
+}
+
+/*
+ * One of these is allocated per bio.
+ */
+struct dm_io {
+ struct mapped_device *md;
+ blk_status_t status;
+ atomic_t io_count;
+ struct bio *bio;
+ unsigned long start_time;
+ spinlock_t endio_lock;
+ struct dm_stats_aux stats_aux;
+};
+
+#define MINOR_ALLOCED ((void *)-1)
+
+/*
+ * Bits for the md->flags field.
+ */
+#define DMF_BLOCK_IO_FOR_SUSPEND 0
+#define DMF_SUSPENDED 1
+#define DMF_FROZEN 2
+#define DMF_FREEING 3
+#define DMF_DELETING 4
+#define DMF_NOFLUSH_SUSPENDING 5
+#define DMF_DEFERRED_REMOVE 6
+#define DMF_SUSPENDED_INTERNALLY 7
+
+#define DM_NUMA_NODE NUMA_NO_NODE
+static int dm_numa_node = DM_NUMA_NODE;
+
+/*
+ * For mempools pre-allocation at the table loading time.
+ */
+struct dm_md_mempools {
+ mempool_t *io_pool;
+ struct bio_set *bs;
+};
+
+struct table_device {
+ struct list_head list;
+ atomic_t count;
+ struct dm_dev dm_dev;
+};
+
+static struct kmem_cache *_io_cache;
+static struct kmem_cache *_rq_tio_cache;
+static struct kmem_cache *_rq_cache;
+
+/*
+ * Bio-based DM's mempools' reserved IOs set by the user.
+ */
+#define RESERVED_BIO_BASED_IOS 16
+static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
+
+static int __dm_get_module_param_int(int *module_param, int min, int max)
+{
+ int param = ACCESS_ONCE(*module_param);
+ int modified_param = 0;
+ bool modified = true;
+
+ if (param < min)
+ modified_param = min;
+ else if (param > max)
+ modified_param = max;
+ else
+ modified = false;
+
+ if (modified) {
+ (void)cmpxchg(module_param, param, modified_param);
+ param = modified_param;
+ }
+
+ return param;
+}
+
+unsigned __dm_get_module_param(unsigned *module_param,
+ unsigned def, unsigned max)
+{
+ unsigned param = ACCESS_ONCE(*module_param);
+ unsigned modified_param = 0;
+
+ if (!param)
+ modified_param = def;
+ else if (param > max)
+ modified_param = max;
+
+ if (modified_param) {
+ (void)cmpxchg(module_param, param, modified_param);
+ param = modified_param;
+ }
+
+ return param;
+}
+
+unsigned dm_get_reserved_bio_based_ios(void)
+{
+ return __dm_get_module_param(&reserved_bio_based_ios,
+ RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS);
+}
+EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
+
+static unsigned dm_get_numa_node(void)
+{
+ return __dm_get_module_param_int(&dm_numa_node,
+ DM_NUMA_NODE, num_online_nodes() - 1);
+}
+
+static int __init local_init(void)
+{
+ int r = -ENOMEM;
+
+ /* allocate a slab for the dm_ios */
+ _io_cache = KMEM_CACHE(dm_io, 0);
+ if (!_io_cache)
+ return r;
+
+ _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
+ if (!_rq_tio_cache)
+ goto out_free_io_cache;
+
+ _rq_cache = kmem_cache_create("dm_old_clone_request", sizeof(struct request),
+ __alignof__(struct request), 0, NULL);
+ if (!_rq_cache)
+ goto out_free_rq_tio_cache;
+
+ r = dm_uevent_init();
+ if (r)
+ goto out_free_rq_cache;
+
+ deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
+ if (!deferred_remove_workqueue) {
+ r = -ENOMEM;
+ goto out_uevent_exit;
+ }
+
+ _major = major;
+ r = register_blkdev(_major, _name);
+ if (r < 0)
+ goto out_free_workqueue;
+
+ if (!_major)
+ _major = r;
+
+ return 0;
+
+out_free_workqueue:
+ destroy_workqueue(deferred_remove_workqueue);
+out_uevent_exit:
+ dm_uevent_exit();
+out_free_rq_cache:
+ kmem_cache_destroy(_rq_cache);
+out_free_rq_tio_cache:
+ kmem_cache_destroy(_rq_tio_cache);
+out_free_io_cache:
+ kmem_cache_destroy(_io_cache);
+
+ return r;
+}
+
+static void local_exit(void)
+{
+ flush_scheduled_work();
+ destroy_workqueue(deferred_remove_workqueue);
+
+ kmem_cache_destroy(_rq_cache);
+ kmem_cache_destroy(_rq_tio_cache);
+ kmem_cache_destroy(_io_cache);
+ unregister_blkdev(_major, _name);
+ dm_uevent_exit();
+
+ _major = 0;
+
+ DMINFO("cleaned up");
+}
+
+static int (*_inits[])(void) __initdata = {
+ local_init,
+ dm_target_init,
+ dm_linear_init,
+ dm_stripe_init,
+ dm_io_init,
+ dm_kcopyd_init,
+ dm_interface_init,
+ dm_statistics_init,
+};
+
+static void (*_exits[])(void) = {
+ local_exit,
+ dm_target_exit,
+ dm_linear_exit,
+ dm_stripe_exit,
+ dm_io_exit,
+ dm_kcopyd_exit,
+ dm_interface_exit,
+ dm_statistics_exit,
+};
+
+static int __init dm_init(void)
+{
+ const int count = ARRAY_SIZE(_inits);
+
+ int r, i;
+
+ for (i = 0; i < count; i++) {
+ r = _inits[i]();
+ if (r)
+ goto bad;
+ }
+
+ return 0;
+
+ bad:
+ while (i--)
+ _exits[i]();
+
+ return r;
+}
+
+static void __exit dm_exit(void)
+{
+ int i = ARRAY_SIZE(_exits);
+
+ while (i--)
+ _exits[i]();
+
+ /*
+ * Should be empty by this point.
+ */
+ idr_destroy(&_minor_idr);
+}
+
+/*
+ * Block device functions
+ */
+int dm_deleting_md(struct mapped_device *md)
+{
+ return test_bit(DMF_DELETING, &md->flags);
+}
+
+static int dm_blk_open(struct block_device *bdev, fmode_t mode)
+{
+ struct mapped_device *md;
+
+ spin_lock(&_minor_lock);
+
+ md = bdev->bd_disk->private_data;
+ if (!md)
+ goto out;
+
+ if (test_bit(DMF_FREEING, &md->flags) ||
+ dm_deleting_md(md)) {
+ md = NULL;
+ goto out;
+ }
+
+ dm_get(md);
+ atomic_inc(&md->open_count);
+out:
+ spin_unlock(&_minor_lock);
+
+ return md ? 0 : -ENXIO;
+}
+
+static void dm_blk_close(struct gendisk *disk, fmode_t mode)
+{
+ struct mapped_device *md;
+
+ spin_lock(&_minor_lock);
+
+ md = disk->private_data;
+ if (WARN_ON(!md))
+ goto out;
+
+ if (atomic_dec_and_test(&md->open_count) &&
+ (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
+ queue_work(deferred_remove_workqueue, &deferred_remove_work);
+
+ dm_put(md);
+out:
+ spin_unlock(&_minor_lock);
+}
+
+int dm_open_count(struct mapped_device *md)
+{
+ return atomic_read(&md->open_count);
+}
+
+/*
+ * Guarantees nothing is using the device before it's deleted.
+ */
+int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
+{
+ int r = 0;
+
+ spin_lock(&_minor_lock);
+
+ if (dm_open_count(md)) {
+ r = -EBUSY;
+ if (mark_deferred)
+ set_bit(DMF_DEFERRED_REMOVE, &md->flags);
+ } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
+ r = -EEXIST;
+ else
+ set_bit(DMF_DELETING, &md->flags);
+
+ spin_unlock(&_minor_lock);
+
+ return r;
+}
+
+int dm_cancel_deferred_remove(struct mapped_device *md)
+{
+ int r = 0;
+
+ spin_lock(&_minor_lock);
+
+ if (test_bit(DMF_DELETING, &md->flags))
+ r = -EBUSY;
+ else
+ clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
+
+ spin_unlock(&_minor_lock);
+
+ return r;
+}
+
+static void do_deferred_remove(struct work_struct *w)
+{
+ dm_deferred_remove();
+}
+
+sector_t dm_get_size(struct mapped_device *md)
+{
+ return get_capacity(md->disk);
+}
+
+struct request_queue *dm_get_md_queue(struct mapped_device *md)
+{
+ return md->queue;
+}
+
+struct dm_stats *dm_get_stats(struct mapped_device *md)
+{
+ return &md->stats;
+}
+
+static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+
+ return dm_get_geometry(md, geo);
+}
+
+static int dm_grab_bdev_for_ioctl(struct mapped_device *md,
+ struct block_device **bdev,
+ fmode_t *mode)
+{
+ struct dm_target *tgt;
+ struct dm_table *map;
+ int srcu_idx, r;
+
+retry:
+ r = -ENOTTY;
+ map = dm_get_live_table(md, &srcu_idx);
+ if (!map || !dm_table_get_size(map))
+ goto out;
+
+ /* We only support devices that have a single target */
+ if (dm_table_get_num_targets(map) != 1)
+ goto out;
+
+ tgt = dm_table_get_target(map, 0);
+ if (!tgt->type->prepare_ioctl)
+ goto out;
+
+ if (dm_suspended_md(md)) {
+ r = -EAGAIN;
+ goto out;
+ }
+
+ r = tgt->type->prepare_ioctl(tgt, bdev, mode);
+ if (r < 0)
+ goto out;
+
+ bdgrab(*bdev);
+ dm_put_live_table(md, srcu_idx);
+ return r;
+
+out:
+ dm_put_live_table(md, srcu_idx);
+ if (r == -ENOTCONN && !fatal_signal_pending(current)) {
+ msleep(10);
+ goto retry;
+ }
+ return r;
+}
+
+static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
+ unsigned int cmd, unsigned long arg)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ int r;
+
+ r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
+ if (r < 0)
+ return r;
+
+ if (r > 0) {
+ /*
+ * Target determined this ioctl is being issued against a
+ * subset of the parent bdev; require extra privileges.
+ */
+ if (!capable(CAP_SYS_RAWIO)) {
+ DMWARN_LIMIT(
+ "%s: sending ioctl %x to DM device without required privilege.",
+ current->comm, cmd);
+ r = -ENOIOCTLCMD;
+ goto out;
+ }
+ }
+
+ r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+out:
+ bdput(bdev);
+ return r;
+}
+
+static struct dm_io *alloc_io(struct mapped_device *md)
+{
+ return mempool_alloc(md->io_pool, GFP_NOIO);
+}
+
+static void free_io(struct mapped_device *md, struct dm_io *io)
+{
+ mempool_free(io, md->io_pool);
+}
+
+static void free_tio(struct dm_target_io *tio)
+{
+ bio_put(&tio->clone);
+}
+
+int md_in_flight(struct mapped_device *md)
+{
+ return atomic_read(&md->pending[READ]) +
+ atomic_read(&md->pending[WRITE]);
+}
+
+static void start_io_acct(struct dm_io *io)
+{
+ struct mapped_device *md = io->md;
+ struct bio *bio = io->bio;
+ int cpu;
+ int rw = bio_data_dir(bio);
+
+ io->start_time = jiffies;
+
+ cpu = part_stat_lock();
+ part_round_stats(md->queue, cpu, &dm_disk(md)->part0);
+ part_stat_unlock();
+ atomic_set(&dm_disk(md)->part0.in_flight[rw],
+ atomic_inc_return(&md->pending[rw]));
+
+ if (unlikely(dm_stats_used(&md->stats)))
+ dm_stats_account_io(&md->stats, bio_data_dir(bio),
+ bio->bi_iter.bi_sector, bio_sectors(bio),
+ false, 0, &io->stats_aux);
+}
+
+static void end_io_acct(struct dm_io *io)
+{
+ struct mapped_device *md = io->md;
+ struct bio *bio = io->bio;
+ unsigned long duration = jiffies - io->start_time;
+ int pending;
+ int rw = bio_data_dir(bio);
+
+ generic_end_io_acct(md->queue, rw, &dm_disk(md)->part0, io->start_time);
+
+ if (unlikely(dm_stats_used(&md->stats)))
+ dm_stats_account_io(&md->stats, bio_data_dir(bio),
+ bio->bi_iter.bi_sector, bio_sectors(bio),
+ true, duration, &io->stats_aux);
+
+ /*
+ * After this is decremented the bio must not be touched if it is
+ * a flush.
+ */
+ pending = atomic_dec_return(&md->pending[rw]);
+ atomic_set(&dm_disk(md)->part0.in_flight[rw], pending);
+ pending += atomic_read(&md->pending[rw^0x1]);
+
+ /* nudge anyone waiting on suspend queue */
+ if (!pending)
+ wake_up(&md->wait);
+}
+
+/*
+ * Add the bio to the list of deferred io.
+ */
+static void queue_io(struct mapped_device *md, struct bio *bio)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&md->deferred_lock, flags);
+ bio_list_add(&md->deferred, bio);
+ spin_unlock_irqrestore(&md->deferred_lock, flags);
+ queue_work(md->wq, &md->work);
+}
+
+/*
+ * Everyone (including functions in this file), should use this
+ * function to access the md->map field, and make sure they call
+ * dm_put_live_table() when finished.
+ */
+struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
+{
+ *srcu_idx = srcu_read_lock(&md->io_barrier);
+
+ return srcu_dereference(md->map, &md->io_barrier);
+}
+
+void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
+{
+ srcu_read_unlock(&md->io_barrier, srcu_idx);
+}
+
+void dm_sync_table(struct mapped_device *md)
+{
+ synchronize_srcu(&md->io_barrier);
+ synchronize_rcu_expedited();
+}
+
+/*
+ * A fast alternative to dm_get_live_table/dm_put_live_table.
+ * The caller must not block between these two functions.
+ */
+static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
+{
+ rcu_read_lock();
+ return rcu_dereference(md->map);
+}
+
+static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
+{
+ rcu_read_unlock();
+}
+
+/*
+ * Open a table device so we can use it as a map destination.
+ */
+static int open_table_device(struct table_device *td, dev_t dev,
+ struct mapped_device *md)
+{
+ static char *_claim_ptr = "I belong to device-mapper";
+ struct block_device *bdev;
+
+ int r;
+
+ BUG_ON(td->dm_dev.bdev);
+
+ bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _claim_ptr);
+ if (IS_ERR(bdev))
+ return PTR_ERR(bdev);
+
+ r = bd_link_disk_holder(bdev, dm_disk(md));
+ if (r) {
+ blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
+ return r;
+ }
+
+ td->dm_dev.bdev = bdev;
+ td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
+ return 0;
+}
+
+/*
+ * Close a table device that we've been using.
+ */
+static void close_table_device(struct table_device *td, struct mapped_device *md)
+{
+ if (!td->dm_dev.bdev)
+ return;
+
+ bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
+ blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
+ put_dax(td->dm_dev.dax_dev);
+ td->dm_dev.bdev = NULL;
+ td->dm_dev.dax_dev = NULL;
+}
+
+static struct table_device *find_table_device(struct list_head *l, dev_t dev,
+ fmode_t mode) {
+ struct table_device *td;
+
+ list_for_each_entry(td, l, list)
+ if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
+ return td;
+
+ return NULL;
+}
+
+int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
+ struct dm_dev **result) {
+ int r;
+ struct table_device *td;
+
+ mutex_lock(&md->table_devices_lock);
+ td = find_table_device(&md->table_devices, dev, mode);
+ if (!td) {
+ td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
+ if (!td) {
+ mutex_unlock(&md->table_devices_lock);
+ return -ENOMEM;
+ }
+
+ td->dm_dev.mode = mode;
+ td->dm_dev.bdev = NULL;
+
+ if ((r = open_table_device(td, dev, md))) {
+ mutex_unlock(&md->table_devices_lock);
+ kfree(td);
+ return r;
+ }
+
+ format_dev_t(td->dm_dev.name, dev);
+
+ atomic_set(&td->count, 0);
+ list_add(&td->list, &md->table_devices);
+ }
+ atomic_inc(&td->count);
+ mutex_unlock(&md->table_devices_lock);
+
+ *result = &td->dm_dev;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_get_table_device);
+
+void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
+{
+ struct table_device *td = container_of(d, struct table_device, dm_dev);
+
+ mutex_lock(&md->table_devices_lock);
+ if (atomic_dec_and_test(&td->count)) {
+ close_table_device(td, md);
+ list_del(&td->list);
+ kfree(td);
+ }
+ mutex_unlock(&md->table_devices_lock);
+}
+EXPORT_SYMBOL(dm_put_table_device);
+
+static void free_table_devices(struct list_head *devices)
+{
+ struct list_head *tmp, *next;
+
+ list_for_each_safe(tmp, next, devices) {
+ struct table_device *td = list_entry(tmp, struct table_device, list);
+
+ DMWARN("dm_destroy: %s still exists with %d references",
+ td->dm_dev.name, atomic_read(&td->count));
+ kfree(td);
+ }
+}
+
+/*
+ * Get the geometry associated with a dm device
+ */
+int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
+{
+ *geo = md->geometry;
+
+ return 0;
+}
+
+/*
+ * Set the geometry of a device.
+ */
+int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
+{
+ sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
+
+ if (geo->start > sz) {
+ DMWARN("Start sector is beyond the geometry limits.");
+ return -EINVAL;
+ }
+
+ md->geometry = *geo;
+
+ return 0;
+}
+
+/*-----------------------------------------------------------------
+ * CRUD START:
+ * A more elegant soln is in the works that uses the queue
+ * merge fn, unfortunately there are a couple of changes to
+ * the block layer that I want to make for this. So in the
+ * interests of getting something for people to use I give
+ * you this clearly demarcated crap.
+ *---------------------------------------------------------------*/
+
+static int __noflush_suspending(struct mapped_device *md)
+{
+ return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
+}
+
+/*
+ * Decrements the number of outstanding ios that a bio has been
+ * cloned into, completing the original io if necc.
+ */
+static void dec_pending(struct dm_io *io, blk_status_t error)
+{
+ unsigned long flags;
+ blk_status_t io_error;
+ struct bio *bio;
+ struct mapped_device *md = io->md;
+
+ /* Push-back supersedes any I/O errors */
+ if (unlikely(error)) {
+ spin_lock_irqsave(&io->endio_lock, flags);
+ if (!(io->status == BLK_STS_DM_REQUEUE &&
+ __noflush_suspending(md)))
+ io->status = error;
+ spin_unlock_irqrestore(&io->endio_lock, flags);
+ }
+
+ if (atomic_dec_and_test(&io->io_count)) {
+ if (io->status == BLK_STS_DM_REQUEUE) {
+ /*
+ * Target requested pushing back the I/O.
+ */
+ spin_lock_irqsave(&md->deferred_lock, flags);
+ if (__noflush_suspending(md))
+ bio_list_add_head(&md->deferred, io->bio);
+ else
+ /* noflush suspend was interrupted. */
+ io->status = BLK_STS_IOERR;
+ spin_unlock_irqrestore(&md->deferred_lock, flags);
+ }
+
+ io_error = io->status;
+ bio = io->bio;
+ end_io_acct(io);
+ free_io(md, io);
+
+ if (io_error == BLK_STS_DM_REQUEUE)
+ return;
+
+ if ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size) {
+ /*
+ * Preflush done for flush with data, reissue
+ * without REQ_PREFLUSH.
+ */
+ bio->bi_opf &= ~REQ_PREFLUSH;
+ queue_io(md, bio);
+ } else {
+ /* done with normal IO or empty flush */
+ if (io_error)
+ bio->bi_status = io_error;
+ bio_endio(bio);
+ }
+ }
+}
+
+void disable_write_same(struct mapped_device *md)
+{
+ struct queue_limits *limits = dm_get_queue_limits(md);
+
+ /* device doesn't really support WRITE SAME, disable it */
+ limits->max_write_same_sectors = 0;
+}
+
+void disable_write_zeroes(struct mapped_device *md)
+{
+ struct queue_limits *limits = dm_get_queue_limits(md);
+
+ /* device doesn't really support WRITE ZEROES, disable it */
+ limits->max_write_zeroes_sectors = 0;
+}
+
+static void clone_endio(struct bio *bio)
+{
+ blk_status_t error = bio->bi_status;
+ struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
+ struct dm_io *io = tio->io;
+ struct mapped_device *md = tio->io->md;
+ dm_endio_fn endio = tio->ti->type->end_io;
+
+ if (unlikely(error == BLK_STS_TARGET)) {
+ if (bio_op(bio) == REQ_OP_WRITE_SAME &&
+ !bio->bi_disk->queue->limits.max_write_same_sectors)
+ disable_write_same(md);
+ if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
+ !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
+ disable_write_zeroes(md);
+ }
+
+ if (endio) {
+ int r = endio(tio->ti, bio, &error);
+ switch (r) {
+ case DM_ENDIO_REQUEUE:
+ error = BLK_STS_DM_REQUEUE;
+ /*FALLTHRU*/
+ case DM_ENDIO_DONE:
+ break;
+ case DM_ENDIO_INCOMPLETE:
+ /* The target will handle the io */
+ return;
+ default:
+ DMWARN("unimplemented target endio return value: %d", r);
+ BUG();
+ }
+ }
+
+ free_tio(tio);
+ dec_pending(io, error);
+}
+
+/*
+ * Return maximum size of I/O possible at the supplied sector up to the current
+ * target boundary.
+ */
+static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
+{
+ sector_t target_offset = dm_target_offset(ti, sector);
+
+ return ti->len - target_offset;
+}
+
+static sector_t max_io_len(sector_t sector, struct dm_target *ti)
+{
+ sector_t len = max_io_len_target_boundary(sector, ti);
+ sector_t offset, max_len;
+
+ /*
+ * Does the target need to split even further?
+ */
+ if (ti->max_io_len) {
+ offset = dm_target_offset(ti, sector);
+ if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
+ max_len = sector_div(offset, ti->max_io_len);
+ else
+ max_len = offset & (ti->max_io_len - 1);
+ max_len = ti->max_io_len - max_len;
+
+ if (len > max_len)
+ len = max_len;
+ }
+
+ return len;
+}
+
+int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
+{
+ if (len > UINT_MAX) {
+ DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
+ (unsigned long long)len, UINT_MAX);
+ ti->error = "Maximum size of target IO is too large";
+ return -EINVAL;
+ }
+
+ ti->max_io_len = (uint32_t) len;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
+
+static struct dm_target *dm_dax_get_live_target(struct mapped_device *md,
+ sector_t sector, int *srcu_idx)
+{
+ struct dm_table *map;
+ struct dm_target *ti;
+
+ map = dm_get_live_table(md, srcu_idx);
+ if (!map)
+ return NULL;
+
+ ti = dm_table_find_target(map, sector);
+ if (!dm_target_is_valid(ti))
+ return NULL;
+
+ return ti;
+}
+
+static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
+ long nr_pages, void **kaddr, pfn_t *pfn)
+{
+ struct mapped_device *md = dax_get_private(dax_dev);
+ sector_t sector = pgoff * PAGE_SECTORS;
+ struct dm_target *ti;
+ long len, ret = -EIO;
+ int srcu_idx;
+
+ ti = dm_dax_get_live_target(md, sector, &srcu_idx);
+
+ if (!ti)
+ goto out;
+ if (!ti->type->direct_access)
+ goto out;
+ len = max_io_len(sector, ti) / PAGE_SECTORS;
+ if (len < 1)
+ goto out;
+ nr_pages = min(len, nr_pages);
+ ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn);
+
+ out:
+ dm_put_live_table(md, srcu_idx);
+
+ return ret;
+}
+
+static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
+ void *addr, size_t bytes, struct iov_iter *i)
+{
+ struct mapped_device *md = dax_get_private(dax_dev);
+ sector_t sector = pgoff * PAGE_SECTORS;
+ struct dm_target *ti;
+ long ret = 0;
+ int srcu_idx;
+
+ ti = dm_dax_get_live_target(md, sector, &srcu_idx);
+
+ if (!ti)
+ goto out;
+ if (!ti->type->dax_copy_from_iter) {
+ ret = copy_from_iter(addr, bytes, i);
+ goto out;
+ }
+ ret = ti->type->dax_copy_from_iter(ti, pgoff, addr, bytes, i);
+ out:
+ dm_put_live_table(md, srcu_idx);
+
+ return ret;
+}
+
+/*
+ * A target may call dm_accept_partial_bio only from the map routine. It is
+ * allowed for all bio types except REQ_PREFLUSH.
+ *
+ * dm_accept_partial_bio informs the dm that the target only wants to process
+ * additional n_sectors sectors of the bio and the rest of the data should be
+ * sent in a next bio.
+ *
+ * A diagram that explains the arithmetics:
+ * +--------------------+---------------+-------+
+ * | 1 | 2 | 3 |
+ * +--------------------+---------------+-------+
+ *
+ * <-------------- *tio->len_ptr --------------->
+ * <------- bi_size ------->
+ * <-- n_sectors -->
+ *
+ * Region 1 was already iterated over with bio_advance or similar function.
+ * (it may be empty if the target doesn't use bio_advance)
+ * Region 2 is the remaining bio size that the target wants to process.
+ * (it may be empty if region 1 is non-empty, although there is no reason
+ * to make it empty)
+ * The target requires that region 3 is to be sent in the next bio.
+ *
+ * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
+ * the partially processed part (the sum of regions 1+2) must be the same for all
+ * copies of the bio.
+ */
+void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
+{
+ struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
+ unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
+ BUG_ON(bio->bi_opf & REQ_PREFLUSH);
+ BUG_ON(bi_size > *tio->len_ptr);
+ BUG_ON(n_sectors > bi_size);
+ *tio->len_ptr -= bi_size - n_sectors;
+ bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
+}
+EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
+
+/*
+ * The zone descriptors obtained with a zone report indicate zone positions
+ * within the target backing device, regardless of that device is a partition
+ * and regardless of the target mapping start sector on the device or partition.
+ * The zone descriptors start sector and write pointer position must be adjusted
+ * to match their relative position within the dm device.
+ * A target may call dm_remap_zone_report() after completion of a
+ * REQ_OP_ZONE_REPORT bio to remap the zone descriptors obtained from the
+ * backing device.
+ */
+void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start)
+{
+#ifdef CONFIG_BLK_DEV_ZONED
+ struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
+ struct bio *report_bio = tio->io->bio;
+ struct blk_zone_report_hdr *hdr = NULL;
+ struct blk_zone *zone;
+ unsigned int nr_rep = 0;
+ unsigned int ofst;
+ sector_t part_offset;
+ struct bio_vec bvec;
+ struct bvec_iter iter;
+ void *addr;
+
+ if (bio->bi_status)
+ return;
+
+ /*
+ * bio sector was incremented by the request size on completion. Taking
+ * into account the original request sector, the target start offset on
+ * the backing device and the target mapping offset (ti->begin), the
+ * start sector of the backing device. The partition offset is always 0
+ * if the target uses a whole device.
+ */
+ part_offset = bio->bi_iter.bi_sector + ti->begin - (start + bio_end_sector(report_bio));
+
+ /*
+ * Remap the start sector of the reported zones. For sequential zones,
+ * also remap the write pointer position.
+ */
+ bio_for_each_segment(bvec, report_bio, iter) {
+ addr = kmap_atomic(bvec.bv_page);
+
+ /* Remember the report header in the first page */
+ if (!hdr) {
+ hdr = addr;
+ ofst = sizeof(struct blk_zone_report_hdr);
+ } else
+ ofst = 0;
+
+ /* Set zones start sector */
+ while (hdr->nr_zones && ofst < bvec.bv_len) {
+ zone = addr + ofst;
+ zone->start -= part_offset;
+ if (zone->start >= start + ti->len) {
+ hdr->nr_zones = 0;
+ break;
+ }
+ zone->start = zone->start + ti->begin - start;
+ if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
+ if (zone->cond == BLK_ZONE_COND_FULL)
+ zone->wp = zone->start + zone->len;
+ else if (zone->cond == BLK_ZONE_COND_EMPTY)
+ zone->wp = zone->start;
+ else
+ zone->wp = zone->wp + ti->begin - start - part_offset;
+ }
+ ofst += sizeof(struct blk_zone);
+ hdr->nr_zones--;
+ nr_rep++;
+ }
+
+ if (addr != hdr)
+ kunmap_atomic(addr);
+
+ if (!hdr->nr_zones)
+ break;
+ }
+
+ if (hdr) {
+ hdr->nr_zones = nr_rep;
+ kunmap_atomic(hdr);
+ }
+
+ bio_advance(report_bio, report_bio->bi_iter.bi_size);
+
+#else /* !CONFIG_BLK_DEV_ZONED */
+ bio->bi_status = BLK_STS_NOTSUPP;
+#endif
+}
+EXPORT_SYMBOL_GPL(dm_remap_zone_report);
+
+/*
+ * Flush current->bio_list when the target map method blocks.
+ * This fixes deadlocks in snapshot and possibly in other targets.
+ */
+struct dm_offload {
+ struct blk_plug plug;
+ struct blk_plug_cb cb;
+};
+
+static void flush_current_bio_list(struct blk_plug_cb *cb, bool from_schedule)
+{
+ struct dm_offload *o = container_of(cb, struct dm_offload, cb);
+ struct bio_list list;
+ struct bio *bio;
+ int i;
+
+ INIT_LIST_HEAD(&o->cb.list);
+
+ if (unlikely(!current->bio_list))
+ return;
+
+ for (i = 0; i < 2; i++) {
+ list = current->bio_list[i];
+ bio_list_init(¤t->bio_list[i]);
+
+ while ((bio = bio_list_pop(&list))) {
+ struct bio_set *bs = bio->bi_pool;
+ if (unlikely(!bs) || bs == fs_bio_set ||
+ !bs->rescue_workqueue) {
+ bio_list_add(¤t->bio_list[i], bio);
+ continue;
+ }
+
+ spin_lock(&bs->rescue_lock);
+ bio_list_add(&bs->rescue_list, bio);
+ queue_work(bs->rescue_workqueue, &bs->rescue_work);
+ spin_unlock(&bs->rescue_lock);
+ }
+ }
+}
+
+static void dm_offload_start(struct dm_offload *o)
+{
+ blk_start_plug(&o->plug);
+ o->cb.callback = flush_current_bio_list;
+ list_add(&o->cb.list, ¤t->plug->cb_list);
+}
+
+static void dm_offload_end(struct dm_offload *o)
+{
+ list_del(&o->cb.list);
+ blk_finish_plug(&o->plug);
+}
+
+static void __map_bio(struct dm_target_io *tio)
+{
+ int r;
+ sector_t sector;
+ struct dm_offload o;
+ struct bio *clone = &tio->clone;
+ struct dm_target *ti = tio->ti;
+
+ clone->bi_end_io = clone_endio;
+
+ /*
+ * Map the clone. If r == 0 we don't need to do
+ * anything, the target has assumed ownership of
+ * this io.
+ */
+ atomic_inc(&tio->io->io_count);
+ sector = clone->bi_iter.bi_sector;
+
+ dm_offload_start(&o);
+ r = ti->type->map(ti, clone);
+ dm_offload_end(&o);
+
+ switch (r) {
+ case DM_MAPIO_SUBMITTED:
+ break;
+ case DM_MAPIO_REMAPPED:
+ /* the bio has been remapped so dispatch it */
+ trace_block_bio_remap(clone->bi_disk->queue, clone,
+ bio_dev(tio->io->bio), sector);
+ generic_make_request(clone);
+ break;
+ case DM_MAPIO_KILL:
+ dec_pending(tio->io, BLK_STS_IOERR);
+ free_tio(tio);
+ break;
+ case DM_MAPIO_REQUEUE:
+ dec_pending(tio->io, BLK_STS_DM_REQUEUE);
+ free_tio(tio);
+ break;
+ default:
+ DMWARN("unimplemented target map return value: %d", r);
+ BUG();
+ }
+}
+
+struct clone_info {
+ struct mapped_device *md;
+ struct dm_table *map;
+ struct bio *bio;
+ struct dm_io *io;
+ sector_t sector;
+ unsigned sector_count;
+};
+
+static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
+{
+ bio->bi_iter.bi_sector = sector;
+ bio->bi_iter.bi_size = to_bytes(len);
+}
+
+/*
+ * Creates a bio that consists of range of complete bvecs.
+ */
+static int clone_bio(struct dm_target_io *tio, struct bio *bio,
+ sector_t sector, unsigned len)
+{
+ struct bio *clone = &tio->clone;
+
+ __bio_clone_fast(clone, bio);
+
+ if (unlikely(bio_integrity(bio) != NULL)) {
+ int r;
+
+ if (unlikely(!dm_target_has_integrity(tio->ti->type) &&
+ !dm_target_passes_integrity(tio->ti->type))) {
+ DMWARN("%s: the target %s doesn't support integrity data.",
+ dm_device_name(tio->io->md),
+ tio->ti->type->name);
+ return -EIO;
+ }
+
+ r = bio_integrity_clone(clone, bio, GFP_NOIO);
+ if (r < 0)
+ return r;
+ }
+
+ if (bio_op(bio) != REQ_OP_ZONE_REPORT)
+ bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
+ clone->bi_iter.bi_size = to_bytes(len);
+
+ if (unlikely(bio_integrity(bio) != NULL))
+ bio_integrity_trim(clone);
+
+ return 0;
+}
+
+static struct dm_target_io *alloc_tio(struct clone_info *ci,
+ struct dm_target *ti,
+ unsigned target_bio_nr)
+{
+ struct dm_target_io *tio;
+ struct bio *clone;
+
+ clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
+ tio = container_of(clone, struct dm_target_io, clone);
+
+ tio->io = ci->io;
+ tio->ti = ti;
+ tio->target_bio_nr = target_bio_nr;
+
+ return tio;
+}
+
+static void __clone_and_map_simple_bio(struct clone_info *ci,
+ struct dm_target *ti,
+ unsigned target_bio_nr, unsigned *len)
+{
+ struct dm_target_io *tio = alloc_tio(ci, ti, target_bio_nr);
+ struct bio *clone = &tio->clone;
+
+ tio->len_ptr = len;
+
+ __bio_clone_fast(clone, ci->bio);
+ if (len)
+ bio_setup_sector(clone, ci->sector, *len);
+
+ __map_bio(tio);
+}
+
+static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
+ unsigned num_bios, unsigned *len)
+{
+ unsigned target_bio_nr;
+
+ for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++)
+ __clone_and_map_simple_bio(ci, ti, target_bio_nr, len);
+}
+
+static int __send_empty_flush(struct clone_info *ci)
+{
+ unsigned target_nr = 0;
+ struct dm_target *ti;
+
+ BUG_ON(bio_has_data(ci->bio));
+ while ((ti = dm_table_get_target(ci->map, target_nr++)))
+ __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
+
+ return 0;
+}
+
+static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
+ sector_t sector, unsigned *len)
+{
+ struct bio *bio = ci->bio;
+ struct dm_target_io *tio;
+ unsigned target_bio_nr;
+ unsigned num_target_bios = 1;
+ int r = 0;
+
+ /*
+ * Does the target want to receive duplicate copies of the bio?
+ */
+ if (bio_data_dir(bio) == WRITE && ti->num_write_bios)
+ num_target_bios = ti->num_write_bios(ti, bio);
+
+ for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
+ tio = alloc_tio(ci, ti, target_bio_nr);
+ tio->len_ptr = len;
+ r = clone_bio(tio, bio, sector, *len);
+ if (r < 0) {
+ free_tio(tio);
+ break;
+ }
+ __map_bio(tio);
+ }
+
+ return r;
+}
+
+typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
+
+static unsigned get_num_discard_bios(struct dm_target *ti)
+{
+ return ti->num_discard_bios;
+}
+
+static unsigned get_num_write_same_bios(struct dm_target *ti)
+{
+ return ti->num_write_same_bios;
+}
+
+static unsigned get_num_write_zeroes_bios(struct dm_target *ti)
+{
+ return ti->num_write_zeroes_bios;
+}
+
+typedef bool (*is_split_required_fn)(struct dm_target *ti);
+
+static bool is_split_required_for_discard(struct dm_target *ti)
+{
+ return ti->split_discard_bios;
+}
+
+static int __send_changing_extent_only(struct clone_info *ci,
+ get_num_bios_fn get_num_bios,
+ is_split_required_fn is_split_required)
+{
+ struct dm_target *ti;
+ unsigned len;
+ unsigned num_bios;
+
+ do {
+ ti = dm_table_find_target(ci->map, ci->sector);
+ if (!dm_target_is_valid(ti))
+ return -EIO;
+
+ /*
+ * Even though the device advertised support for this type of
+ * request, that does not mean every target supports it, and
+ * reconfiguration might also have changed that since the
+ * check was performed.
+ */
+ num_bios = get_num_bios ? get_num_bios(ti) : 0;
+ if (!num_bios)
+ return -EOPNOTSUPP;
+
+ if (is_split_required && !is_split_required(ti))
+ len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
+ else
+ len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
+
+ __send_duplicate_bios(ci, ti, num_bios, &len);
+
+ ci->sector += len;
+ } while (ci->sector_count -= len);
+
+ return 0;
+}
+
+static int __send_discard(struct clone_info *ci)
+{
+ return __send_changing_extent_only(ci, get_num_discard_bios,
+ is_split_required_for_discard);
+}
+
+static int __send_write_same(struct clone_info *ci)
+{
+ return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
+}
+
+static int __send_write_zeroes(struct clone_info *ci)
+{
+ return __send_changing_extent_only(ci, get_num_write_zeroes_bios, NULL);
+}
+
+/*
+ * Select the correct strategy for processing a non-flush bio.
+ */
+static int __split_and_process_non_flush(struct clone_info *ci)
+{
+ struct bio *bio = ci->bio;
+ struct dm_target *ti;
+ unsigned len;
+ int r;
+
+ if (unlikely(bio_op(bio) == REQ_OP_DISCARD))
+ return __send_discard(ci);
+ else if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))
+ return __send_write_same(ci);
+ else if (unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES))
+ return __send_write_zeroes(ci);
+
+ ti = dm_table_find_target(ci->map, ci->sector);
+ if (!dm_target_is_valid(ti))
+ return -EIO;
+
+ if (bio_op(bio) == REQ_OP_ZONE_REPORT)
+ len = ci->sector_count;
+ else
+ len = min_t(sector_t, max_io_len(ci->sector, ti),
+ ci->sector_count);
+
+ r = __clone_and_map_data_bio(ci, ti, ci->sector, &len);
+ if (r < 0)
+ return r;
+
+ ci->sector += len;
+ ci->sector_count -= len;
+
+ return 0;
+}
+
+/*
+ * Entry point to split a bio into clones and submit them to the targets.
+ */
+static void __split_and_process_bio(struct mapped_device *md,
+ struct dm_table *map, struct bio *bio)
+{
+ struct clone_info ci;
+ int error = 0;
+
+ if (unlikely(!map)) {
+ bio_io_error(bio);
+ return;
+ }
+
+ ci.map = map;
+ ci.md = md;
+ ci.io = alloc_io(md);
+ ci.io->status = 0;
+ atomic_set(&ci.io->io_count, 1);
+ ci.io->bio = bio;
+ ci.io->md = md;
+ spin_lock_init(&ci.io->endio_lock);
+ ci.sector = bio->bi_iter.bi_sector;
+
+ start_io_acct(ci.io);
+
+ if (bio->bi_opf & REQ_PREFLUSH) {
+ ci.bio = &ci.md->flush_bio;
+ ci.sector_count = 0;
+ error = __send_empty_flush(&ci);
+ /* dec_pending submits any data associated with flush */
+ } else if (bio_op(bio) == REQ_OP_ZONE_RESET) {
+ ci.bio = bio;
+ ci.sector_count = 0;
+ error = __split_and_process_non_flush(&ci);
+ } else {
+ ci.bio = bio;
+ ci.sector_count = bio_sectors(bio);
+ while (ci.sector_count && !error)
+ error = __split_and_process_non_flush(&ci);
+ }
+
+ /* drop the extra reference count */
+ dec_pending(ci.io, errno_to_blk_status(error));
+}
+/*-----------------------------------------------------------------
+ * CRUD END
+ *---------------------------------------------------------------*/
+
+/*
+ * The request function that just remaps the bio built up by
+ * dm_merge_bvec.
+ */
+static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
+{
+ int rw = bio_data_dir(bio);
+ struct mapped_device *md = q->queuedata;
+ int srcu_idx;
+ struct dm_table *map;
+
+ map = dm_get_live_table(md, &srcu_idx);
+
+ generic_start_io_acct(q, rw, bio_sectors(bio), &dm_disk(md)->part0);
+
+ /* if we're suspended, we have to queue this io for later */
+ if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
+ dm_put_live_table(md, srcu_idx);
+
+ if (!(bio->bi_opf & REQ_RAHEAD))
+ queue_io(md, bio);
+ else
+ bio_io_error(bio);
+ return BLK_QC_T_NONE;
+ }
+
+ __split_and_process_bio(md, map, bio);
+ dm_put_live_table(md, srcu_idx);
+ return BLK_QC_T_NONE;
+}
+
+static int dm_any_congested(void *congested_data, int bdi_bits)
+{
+ int r = bdi_bits;
+ struct mapped_device *md = congested_data;
+ struct dm_table *map;
+
+ if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
+ if (dm_request_based(md)) {
+ /*
+ * With request-based DM we only need to check the
+ * top-level queue for congestion.
+ */
+ r = md->queue->backing_dev_info->wb.state & bdi_bits;
+ } else {
+ map = dm_get_live_table_fast(md);
+ if (map)
+ r = dm_table_any_congested(map, bdi_bits);
+ dm_put_live_table_fast(md);
+ }
+ }
+
+ return r;
+}
+
+/*-----------------------------------------------------------------
+ * An IDR is used to keep track of allocated minor numbers.
+ *---------------------------------------------------------------*/
+static void free_minor(int minor)
+{
+ spin_lock(&_minor_lock);
+ idr_remove(&_minor_idr, minor);
+ spin_unlock(&_minor_lock);
+}
+
+/*
+ * See if the device with a specific minor # is free.
+ */
+static int specific_minor(int minor)
+{
+ int r;
+
+ if (minor >= (1 << MINORBITS))
+ return -EINVAL;
+
+ idr_preload(GFP_KERNEL);
+ spin_lock(&_minor_lock);
+
+ r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
+
+ spin_unlock(&_minor_lock);
+ idr_preload_end();
+ if (r < 0)
+ return r == -ENOSPC ? -EBUSY : r;
+ return 0;
+}
+
+static int next_free_minor(int *minor)
+{
+ int r;
+
+ idr_preload(GFP_KERNEL);
+ spin_lock(&_minor_lock);
+
+ r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
+
+ spin_unlock(&_minor_lock);
+ idr_preload_end();
+ if (r < 0)
+ return r;
+ *minor = r;
+ return 0;
+}
+
+static const struct block_device_operations dm_blk_dops;
+static const struct dax_operations dm_dax_ops;
+
+static void dm_wq_work(struct work_struct *work);
+
+void dm_init_md_queue(struct mapped_device *md)
+{
+ /*
+ * Request-based dm devices cannot be stacked on top of bio-based dm
+ * devices. The type of this dm device may not have been decided yet.
+ * The type is decided at the first table loading time.
+ * To prevent problematic device stacking, clear the queue flag
+ * for request stacking support until then.
+ *
+ * This queue is new, so no concurrency on the queue_flags.
+ */
+ queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
+
+ /*
+ * Initialize data that will only be used by a non-blk-mq DM queue
+ * - must do so here (in alloc_dev callchain) before queue is used
+ */
+ md->queue->queuedata = md;
+}
+
+void dm_init_normal_md_queue(struct mapped_device *md)
+{
+ md->use_blk_mq = false;
+ dm_init_md_queue(md);
+
+ /*
+ * Initialize aspects of queue that aren't relevant for blk-mq
+ */
+ md->queue->backing_dev_info->congested_data = md;
+ md->queue->backing_dev_info->congested_fn = dm_any_congested;
+}
+
+static void cleanup_mapped_device(struct mapped_device *md)
+{
+ if (md->wq)
+ destroy_workqueue(md->wq);
+ if (md->kworker_task)
+ kthread_stop(md->kworker_task);
+ mempool_destroy(md->io_pool);
+ if (md->bs)
+ bioset_free(md->bs);
+
+ if (md->dax_dev) {
+ kill_dax(md->dax_dev);
+ put_dax(md->dax_dev);
+ md->dax_dev = NULL;
+ }
+
+ if (md->disk) {
+ spin_lock(&_minor_lock);
+ md->disk->private_data = NULL;
+ spin_unlock(&_minor_lock);
+ del_gendisk(md->disk);
+ put_disk(md->disk);
+ }
+
+ if (md->queue)
+ blk_cleanup_queue(md->queue);
+
+ cleanup_srcu_struct(&md->io_barrier);
+
+ if (md->bdev) {
+ bdput(md->bdev);
+ md->bdev = NULL;
+ }
+
+ dm_mq_cleanup_mapped_device(md);
+}
+
+/*
+ * Allocate and initialise a blank device with a given minor.
+ */
+static struct mapped_device *alloc_dev(int minor)
+{
+ int r, numa_node_id = dm_get_numa_node();
+ struct dax_device *dax_dev;
+ struct mapped_device *md;
+ void *old_md;
+
+ md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
+ if (!md) {
+ DMWARN("unable to allocate device, out of memory.");
+ return NULL;
+ }
+
+ if (!try_module_get(THIS_MODULE))
+ goto bad_module_get;
+
+ /* get a minor number for the dev */
+ if (minor == DM_ANY_MINOR)
+ r = next_free_minor(&minor);
+ else
+ r = specific_minor(minor);
+ if (r < 0)
+ goto bad_minor;
+
+ r = init_srcu_struct(&md->io_barrier);
+ if (r < 0)
+ goto bad_io_barrier;
+
+ md->numa_node_id = numa_node_id;
+ md->use_blk_mq = dm_use_blk_mq_default();
+ md->init_tio_pdu = false;
+ md->type = DM_TYPE_NONE;
+ mutex_init(&md->suspend_lock);
+ mutex_init(&md->type_lock);
+ mutex_init(&md->table_devices_lock);
+ spin_lock_init(&md->deferred_lock);
+ atomic_set(&md->holders, 1);
+ atomic_set(&md->open_count, 0);
+ atomic_set(&md->event_nr, 0);
+ atomic_set(&md->uevent_seq, 0);
+ INIT_LIST_HEAD(&md->uevent_list);
+ INIT_LIST_HEAD(&md->table_devices);
+ spin_lock_init(&md->uevent_lock);
+
+ md->queue = blk_alloc_queue_node(GFP_KERNEL, numa_node_id);
+ if (!md->queue)
+ goto bad;
+
+ dm_init_md_queue(md);
+ /*
+ * default to bio-based required ->make_request_fn until DM
+ * table is loaded and md->type established. If request-based
+ * table is loaded: blk-mq will override accordingly.
+ */
+ blk_queue_make_request(md->queue, dm_make_request);
+
+ md->disk = alloc_disk_node(1, numa_node_id);
+ if (!md->disk)
+ goto bad;
+
+ atomic_set(&md->pending[0], 0);
+ atomic_set(&md->pending[1], 0);
+ init_waitqueue_head(&md->wait);
+ INIT_WORK(&md->work, dm_wq_work);
+ init_waitqueue_head(&md->eventq);
+ init_completion(&md->kobj_holder.completion);
+ md->kworker_task = NULL;
+
+ md->disk->major = _major;
+ md->disk->first_minor = minor;
+ md->disk->fops = &dm_blk_dops;
+ md->disk->queue = md->queue;
+ md->disk->private_data = md;
+ sprintf(md->disk->disk_name, "dm-%d", minor);
+
+ dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops);
+ if (!dax_dev)
+ goto bad;
+ md->dax_dev = dax_dev;
+
+ add_disk(md->disk);
+ format_dev_t(md->name, MKDEV(_major, minor));
+
+ md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
+ if (!md->wq)
+ goto bad;
+
+ md->bdev = bdget_disk(md->disk, 0);
+ if (!md->bdev)
+ goto bad;
+
+ bio_init(&md->flush_bio, NULL, 0);
+ bio_set_dev(&md->flush_bio, md->bdev);
+ md->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
+
+ dm_stats_init(&md->stats);
+
+ /* Populate the mapping, nobody knows we exist yet */
+ spin_lock(&_minor_lock);
+ old_md = idr_replace(&_minor_idr, md, minor);
+ spin_unlock(&_minor_lock);
+
+ BUG_ON(old_md != MINOR_ALLOCED);
+
+ return md;
+
+bad:
+ cleanup_mapped_device(md);
+bad_io_barrier:
+ free_minor(minor);
+bad_minor:
+ module_put(THIS_MODULE);
+bad_module_get:
+ kvfree(md);
+ return NULL;
+}
+
+static void unlock_fs(struct mapped_device *md);
+
+static void free_dev(struct mapped_device *md)
+{
+ int minor = MINOR(disk_devt(md->disk));
+
+ unlock_fs(md);
+
+ cleanup_mapped_device(md);
+
+ free_table_devices(&md->table_devices);
+ dm_stats_cleanup(&md->stats);
+ free_minor(minor);
+
+ module_put(THIS_MODULE);
+ kvfree(md);
+}
+
+static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
+{
+ struct dm_md_mempools *p = dm_table_get_md_mempools(t);
+
+ if (md->bs) {
+ /* The md already has necessary mempools. */
+ if (dm_table_bio_based(t)) {
+ /*
+ * Reload bioset because front_pad may have changed
+ * because a different table was loaded.
+ */
+ bioset_free(md->bs);
+ md->bs = p->bs;
+ p->bs = NULL;
+ }
+ /*
+ * There's no need to reload with request-based dm
+ * because the size of front_pad doesn't change.
+ * Note for future: If you are to reload bioset,
+ * prep-ed requests in the queue may refer
+ * to bio from the old bioset, so you must walk
+ * through the queue to unprep.
+ */
+ goto out;
+ }
+
+ BUG_ON(!p || md->io_pool || md->bs);
+
+ md->io_pool = p->io_pool;
+ p->io_pool = NULL;
+ md->bs = p->bs;
+ p->bs = NULL;
+
+out:
+ /* mempool bind completed, no longer need any mempools in the table */
+ dm_table_free_md_mempools(t);
+}
+
+/*
+ * Bind a table to the device.
+ */
+static void event_callback(void *context)
+{
+ unsigned long flags;
+ LIST_HEAD(uevents);
+ struct mapped_device *md = (struct mapped_device *) context;
+
+ spin_lock_irqsave(&md->uevent_lock, flags);
+ list_splice_init(&md->uevent_list, &uevents);
+ spin_unlock_irqrestore(&md->uevent_lock, flags);
+
+ dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
+
+ atomic_inc(&md->event_nr);
+ wake_up(&md->eventq);
+ dm_issue_global_event();
+}
+
+/*
+ * Protected by md->suspend_lock obtained by dm_swap_table().
+ */
+static void __set_size(struct mapped_device *md, sector_t size)
+{
+ lockdep_assert_held(&md->suspend_lock);
+
+ set_capacity(md->disk, size);
+
+ i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
+}
+
+/*
+ * Returns old map, which caller must destroy.
+ */
+static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
+ struct queue_limits *limits)
+{
+ struct dm_table *old_map;
+ struct request_queue *q = md->queue;
+ sector_t size;
+
+ lockdep_assert_held(&md->suspend_lock);
+
+ size = dm_table_get_size(t);
+
+ /*
+ * Wipe any geometry if the size of the table changed.
+ */
+ if (size != dm_get_size(md))
+ memset(&md->geometry, 0, sizeof(md->geometry));
+
+ __set_size(md, size);
+
+ dm_table_event_callback(t, event_callback, md);
+
+ /*
+ * The queue hasn't been stopped yet, if the old table type wasn't
+ * for request-based during suspension. So stop it to prevent
+ * I/O mapping before resume.
+ * This must be done before setting the queue restrictions,
+ * because request-based dm may be run just after the setting.
+ */
+ if (dm_table_request_based(t)) {
+ dm_stop_queue(q);
+ /*
+ * Leverage the fact that request-based DM targets are
+ * immutable singletons and establish md->immutable_target
+ * - used to optimize both dm_request_fn and dm_mq_queue_rq
+ */
+ md->immutable_target = dm_table_get_immutable_target(t);
+ }
+
+ __bind_mempools(md, t);
+
+ old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
+ rcu_assign_pointer(md->map, (void *)t);
+ md->immutable_target_type = dm_table_get_immutable_target_type(t);
+
+ dm_table_set_restrictions(t, q, limits);
+ if (old_map)
+ dm_sync_table(md);
+
+ return old_map;
+}
+
+/*
+ * Returns unbound table for the caller to free.
+ */
+static struct dm_table *__unbind(struct mapped_device *md)
+{
+ struct dm_table *map = rcu_dereference_protected(md->map, 1);
+
+ if (!map)
+ return NULL;
+
+ dm_table_event_callback(map, NULL, NULL);
+ RCU_INIT_POINTER(md->map, NULL);
+ dm_sync_table(md);
+
+ return map;
+}
+
+/*
+ * Constructor for a new device.
+ */
+int dm_create(int minor, struct mapped_device **result)
+{
+ struct mapped_device *md;
+
+ md = alloc_dev(minor);
+ if (!md)
+ return -ENXIO;
+
+ dm_sysfs_init(md);
+
+ *result = md;
+ return 0;
+}
+
+/*
+ * Functions to manage md->type.
+ * All are required to hold md->type_lock.
+ */
+void dm_lock_md_type(struct mapped_device *md)
+{
+ mutex_lock(&md->type_lock);
+}
+
+void dm_unlock_md_type(struct mapped_device *md)
+{
+ mutex_unlock(&md->type_lock);
+}
+
+void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type)
+{
+ BUG_ON(!mutex_is_locked(&md->type_lock));
+ md->type = type;
+}
+
+enum dm_queue_mode dm_get_md_type(struct mapped_device *md)
+{
+ return md->type;
+}
+
+struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
+{
+ return md->immutable_target_type;
+}
+
+/*
+ * The queue_limits are only valid as long as you have a reference
+ * count on 'md'.
+ */
+struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
+{
+ BUG_ON(!atomic_read(&md->holders));
+ return &md->queue->limits;
+}
+EXPORT_SYMBOL_GPL(dm_get_queue_limits);
+
+/*
+ * Setup the DM device's queue based on md's type
+ */
+int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
+{
+ int r;
+ enum dm_queue_mode type = dm_get_md_type(md);
+
+ switch (type) {
+ case DM_TYPE_REQUEST_BASED:
+ r = dm_old_init_request_queue(md, t);
+ if (r) {
+ DMERR("Cannot initialize queue for request-based mapped device");
+ return r;
+ }
+ break;
+ case DM_TYPE_MQ_REQUEST_BASED:
+ r = dm_mq_init_request_queue(md, t);
+ if (r) {
+ DMERR("Cannot initialize queue for request-based dm-mq mapped device");
+ return r;
+ }
+ break;
+ case DM_TYPE_BIO_BASED:
+ case DM_TYPE_DAX_BIO_BASED:
+ dm_init_normal_md_queue(md);
+ /*
+ * DM handles splitting bios as needed. Free the bio_split bioset
+ * since it won't be used (saves 1 process per bio-based DM device).
+ */
+ bioset_free(md->queue->bio_split);
+ md->queue->bio_split = NULL;
+ break;
+ case DM_TYPE_NONE:
+ WARN_ON_ONCE(true);
+ break;
+ }
+
+ return 0;
+}
+
+struct mapped_device *dm_get_md(dev_t dev)
+{
+ struct mapped_device *md;
+ unsigned minor = MINOR(dev);
+
+ if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
+ return NULL;
+
+ spin_lock(&_minor_lock);
+
+ md = idr_find(&_minor_idr, minor);
+ if (md) {
+ if ((md == MINOR_ALLOCED ||
+ (MINOR(disk_devt(dm_disk(md))) != minor) ||
+ dm_deleting_md(md) ||
+ test_bit(DMF_FREEING, &md->flags))) {
+ md = NULL;
+ goto out;
+ }
+ dm_get(md);
+ }
+
+out:
+ spin_unlock(&_minor_lock);
+
+ return md;
+}
+EXPORT_SYMBOL_GPL(dm_get_md);
+
+void *dm_get_mdptr(struct mapped_device *md)
+{
+ return md->interface_ptr;
+}
+
+void dm_set_mdptr(struct mapped_device *md, void *ptr)
+{
+ md->interface_ptr = ptr;
+}
+
+void dm_get(struct mapped_device *md)
+{
+ atomic_inc(&md->holders);
+ BUG_ON(test_bit(DMF_FREEING, &md->flags));
+}
+
+int dm_hold(struct mapped_device *md)
+{
+ spin_lock(&_minor_lock);
+ if (test_bit(DMF_FREEING, &md->flags)) {
+ spin_unlock(&_minor_lock);
+ return -EBUSY;
+ }
+ dm_get(md);
+ spin_unlock(&_minor_lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_hold);
+
+const char *dm_device_name(struct mapped_device *md)
+{
+ return md->name;
+}
+EXPORT_SYMBOL_GPL(dm_device_name);
+
+static void __dm_destroy(struct mapped_device *md, bool wait)
+{
+ struct request_queue *q = dm_get_md_queue(md);
+ struct dm_table *map;
+ int srcu_idx;
+
+ might_sleep();
+
+ spin_lock(&_minor_lock);
+ idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
+ set_bit(DMF_FREEING, &md->flags);
+ spin_unlock(&_minor_lock);
+
+ blk_set_queue_dying(q);
+
+ if (dm_request_based(md) && md->kworker_task)
+ kthread_flush_worker(&md->kworker);
+
+ /*
+ * Take suspend_lock so that presuspend and postsuspend methods
+ * do not race with internal suspend.
+ */
+ mutex_lock(&md->suspend_lock);
+ map = dm_get_live_table(md, &srcu_idx);
+ if (!dm_suspended_md(md)) {
+ dm_table_presuspend_targets(map);
+ dm_table_postsuspend_targets(map);
+ }
+ /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
+ dm_put_live_table(md, srcu_idx);
+ mutex_unlock(&md->suspend_lock);
+
+ /*
+ * Rare, but there may be I/O requests still going to complete,
+ * for example. Wait for all references to disappear.
+ * No one should increment the reference count of the mapped_device,
+ * after the mapped_device state becomes DMF_FREEING.
+ */
+ if (wait)
+ while (atomic_read(&md->holders))
+ msleep(1);
+ else if (atomic_read(&md->holders))
+ DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
+ dm_device_name(md), atomic_read(&md->holders));
+
+ dm_sysfs_exit(md);
+ dm_table_destroy(__unbind(md));
+ free_dev(md);
+}
+
+void dm_destroy(struct mapped_device *md)
+{
+ __dm_destroy(md, true);
+}
+
+void dm_destroy_immediate(struct mapped_device *md)
+{
+ __dm_destroy(md, false);
+}
+
+void dm_put(struct mapped_device *md)
+{
+ atomic_dec(&md->holders);
+}
+EXPORT_SYMBOL_GPL(dm_put);
+
+static int dm_wait_for_completion(struct mapped_device *md, long task_state)
+{
+ int r = 0;
+ DEFINE_WAIT(wait);
+
+ while (1) {
+ prepare_to_wait(&md->wait, &wait, task_state);
+
+ if (!md_in_flight(md))
+ break;
+
+ if (signal_pending_state(task_state, current)) {
+ r = -EINTR;
+ break;
+ }
+
+ io_schedule();
+ }
+ finish_wait(&md->wait, &wait);
+
+ return r;
+}
+
+/*
+ * Process the deferred bios
+ */
+static void dm_wq_work(struct work_struct *work)
+{
+ struct mapped_device *md = container_of(work, struct mapped_device,
+ work);
+ struct bio *c;
+ int srcu_idx;
+ struct dm_table *map;
+
+ map = dm_get_live_table(md, &srcu_idx);
+
+ while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
+ spin_lock_irq(&md->deferred_lock);
+ c = bio_list_pop(&md->deferred);
+ spin_unlock_irq(&md->deferred_lock);
+
+ if (!c)
+ break;
+
+ if (dm_request_based(md))
+ generic_make_request(c);
+ else
+ __split_and_process_bio(md, map, c);
+ }
+
+ dm_put_live_table(md, srcu_idx);
+}
+
+static void dm_queue_flush(struct mapped_device *md)
+{
+ clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
+ smp_mb__after_atomic();
+ queue_work(md->wq, &md->work);
+}
+
+/*
+ * Swap in a new table, returning the old one for the caller to destroy.
+ */
+struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
+{
+ struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
+ struct queue_limits limits;
+ int r;
+
+ mutex_lock(&md->suspend_lock);
+
+ /* device must be suspended */
+ if (!dm_suspended_md(md))
+ goto out;
+
+ /*
+ * If the new table has no data devices, retain the existing limits.
+ * This helps multipath with queue_if_no_path if all paths disappear,
+ * then new I/O is queued based on these limits, and then some paths
+ * reappear.
+ */
+ if (dm_table_has_no_data_devices(table)) {
+ live_map = dm_get_live_table_fast(md);
+ if (live_map)
+ limits = md->queue->limits;
+ dm_put_live_table_fast(md);
+ }
+
+ if (!live_map) {
+ r = dm_calculate_queue_limits(table, &limits);
+ if (r) {
+ map = ERR_PTR(r);
+ goto out;
+ }
+ }
+
+ map = __bind(md, table, &limits);
+ dm_issue_global_event();
+
+out:
+ mutex_unlock(&md->suspend_lock);
+ return map;
+}
+
+/*
+ * Functions to lock and unlock any filesystem running on the
+ * device.
+ */
+static int lock_fs(struct mapped_device *md)
+{
+ int r;
+
+ WARN_ON(md->frozen_sb);
+
+ md->frozen_sb = freeze_bdev(md->bdev);
+ if (IS_ERR(md->frozen_sb)) {
+ r = PTR_ERR(md->frozen_sb);
+ md->frozen_sb = NULL;
+ return r;
+ }
+
+ set_bit(DMF_FROZEN, &md->flags);
+
+ return 0;
+}
+
+static void unlock_fs(struct mapped_device *md)
+{
+ if (!test_bit(DMF_FROZEN, &md->flags))
+ return;
+
+ thaw_bdev(md->bdev, md->frozen_sb);
+ md->frozen_sb = NULL;
+ clear_bit(DMF_FROZEN, &md->flags);
+}
+
+/*
+ * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG
+ * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE
+ * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY
+ *
+ * If __dm_suspend returns 0, the device is completely quiescent
+ * now. There is no request-processing activity. All new requests
+ * are being added to md->deferred list.
+ */
+static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
+ unsigned suspend_flags, long task_state,
+ int dmf_suspended_flag)
+{
+ bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
+ bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
+ int r;
+
+ lockdep_assert_held(&md->suspend_lock);
+
+ /*
+ * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
+ * This flag is cleared before dm_suspend returns.
+ */
+ if (noflush)
+ set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
+ else
+ pr_debug("%s: suspending with flush\n", dm_device_name(md));
+
+ /*
+ * This gets reverted if there's an error later and the targets
+ * provide the .presuspend_undo hook.
+ */
+ dm_table_presuspend_targets(map);
+
+ /*
+ * Flush I/O to the device.
+ * Any I/O submitted after lock_fs() may not be flushed.
+ * noflush takes precedence over do_lockfs.
+ * (lock_fs() flushes I/Os and waits for them to complete.)
+ */
+ if (!noflush && do_lockfs) {
+ r = lock_fs(md);
+ if (r) {
+ dm_table_presuspend_undo_targets(map);
+ return r;
+ }
+ }
+
+ /*
+ * Here we must make sure that no processes are submitting requests
+ * to target drivers i.e. no one may be executing
+ * __split_and_process_bio. This is called from dm_request and
+ * dm_wq_work.
+ *
+ * To get all processes out of __split_and_process_bio in dm_request,
+ * we take the write lock. To prevent any process from reentering
+ * __split_and_process_bio from dm_request and quiesce the thread
+ * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
+ * flush_workqueue(md->wq).
+ */
+ set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
+ if (map)
+ synchronize_srcu(&md->io_barrier);
+
+ /*
+ * Stop md->queue before flushing md->wq in case request-based
+ * dm defers requests to md->wq from md->queue.
+ */
+ if (dm_request_based(md)) {
+ dm_stop_queue(md->queue);
+ if (md->kworker_task)
+ kthread_flush_worker(&md->kworker);
+ }
+
+ flush_workqueue(md->wq);
+
+ /*
+ * At this point no more requests are entering target request routines.
+ * We call dm_wait_for_completion to wait for all existing requests
+ * to finish.
+ */
+ r = dm_wait_for_completion(md, task_state);
+ if (!r)
+ set_bit(dmf_suspended_flag, &md->flags);
+
+ if (noflush)
+ clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
+ if (map)
+ synchronize_srcu(&md->io_barrier);
+
+ /* were we interrupted ? */
+ if (r < 0) {
+ dm_queue_flush(md);
+
+ if (dm_request_based(md))
+ dm_start_queue(md->queue);
+
+ unlock_fs(md);
+ dm_table_presuspend_undo_targets(map);
+ /* pushback list is already flushed, so skip flush */
+ }
+
+ return r;
+}
+
+/*
+ * We need to be able to change a mapping table under a mounted
+ * filesystem. For example we might want to move some data in
+ * the background. Before the table can be swapped with
+ * dm_bind_table, dm_suspend must be called to flush any in
+ * flight bios and ensure that any further io gets deferred.
+ */
+/*
+ * Suspend mechanism in request-based dm.
+ *
+ * 1. Flush all I/Os by lock_fs() if needed.
+ * 2. Stop dispatching any I/O by stopping the request_queue.
+ * 3. Wait for all in-flight I/Os to be completed or requeued.
+ *
+ * To abort suspend, start the request_queue.
+ */
+int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
+{
+ struct dm_table *map = NULL;
+ int r = 0;
+
+retry:
+ mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
+
+ if (dm_suspended_md(md)) {
+ r = -EINVAL;
+ goto out_unlock;
+ }
+
+ if (dm_suspended_internally_md(md)) {
+ /* already internally suspended, wait for internal resume */
+ mutex_unlock(&md->suspend_lock);
+ r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
+ if (r)
+ return r;
+ goto retry;
+ }
+
+ map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
+
+ r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);
+ if (r)
+ goto out_unlock;
+
+ dm_table_postsuspend_targets(map);
+
+out_unlock:
+ mutex_unlock(&md->suspend_lock);
+ return r;
+}
+
+static int __dm_resume(struct mapped_device *md, struct dm_table *map)
+{
+ if (map) {
+ int r = dm_table_resume_targets(map);
+ if (r)
+ return r;
+ }
+
+ dm_queue_flush(md);
+
+ /*
+ * Flushing deferred I/Os must be done after targets are resumed
+ * so that mapping of targets can work correctly.
+ * Request-based dm is queueing the deferred I/Os in its request_queue.
+ */
+ if (dm_request_based(md))
+ dm_start_queue(md->queue);
+
+ unlock_fs(md);
+
+ return 0;
+}
+
+int dm_resume(struct mapped_device *md)
+{
+ int r;
+ struct dm_table *map = NULL;
+
+retry:
+ r = -EINVAL;
+ mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
+
+ if (!dm_suspended_md(md))
+ goto out;
+
+ if (dm_suspended_internally_md(md)) {
+ /* already internally suspended, wait for internal resume */
+ mutex_unlock(&md->suspend_lock);
+ r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
+ if (r)
+ return r;
+ goto retry;
+ }
+
+ map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
+ if (!map || !dm_table_get_size(map))
+ goto out;
+
+ r = __dm_resume(md, map);
+ if (r)
+ goto out;
+
+ clear_bit(DMF_SUSPENDED, &md->flags);
+out:
+ mutex_unlock(&md->suspend_lock);
+
+ return r;
+}
+
+/*
+ * Internal suspend/resume works like userspace-driven suspend. It waits
+ * until all bios finish and prevents issuing new bios to the target drivers.
+ * It may be used only from the kernel.
+ */
+
+static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
+{
+ struct dm_table *map = NULL;
+
+ lockdep_assert_held(&md->suspend_lock);
+
+ if (md->internal_suspend_count++)
+ return; /* nested internal suspend */
+
+ if (dm_suspended_md(md)) {
+ set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
+ return; /* nest suspend */
+ }
+
+ map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
+
+ /*
+ * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
+ * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
+ * would require changing .presuspend to return an error -- avoid this
+ * until there is a need for more elaborate variants of internal suspend.
+ */
+ (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
+ DMF_SUSPENDED_INTERNALLY);
+
+ dm_table_postsuspend_targets(map);
+}
+
+static void __dm_internal_resume(struct mapped_device *md)
+{
+ BUG_ON(!md->internal_suspend_count);
+
+ if (--md->internal_suspend_count)
+ return; /* resume from nested internal suspend */
+
+ if (dm_suspended_md(md))
+ goto done; /* resume from nested suspend */
+
+ /*
+ * NOTE: existing callers don't need to call dm_table_resume_targets
+ * (which may fail -- so best to avoid it for now by passing NULL map)
+ */
+ (void) __dm_resume(md, NULL);
+
+done:
+ clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
+ smp_mb__after_atomic();
+ wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
+}
+
+void dm_internal_suspend_noflush(struct mapped_device *md)
+{
+ mutex_lock(&md->suspend_lock);
+ __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
+ mutex_unlock(&md->suspend_lock);
+}
+EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
+
+void dm_internal_resume(struct mapped_device *md)
+{
+ mutex_lock(&md->suspend_lock);
+ __dm_internal_resume(md);
+ mutex_unlock(&md->suspend_lock);
+}
+EXPORT_SYMBOL_GPL(dm_internal_resume);
+
+/*
+ * Fast variants of internal suspend/resume hold md->suspend_lock,
+ * which prevents interaction with userspace-driven suspend.
+ */
+
+void dm_internal_suspend_fast(struct mapped_device *md)
+{
+ mutex_lock(&md->suspend_lock);
+ if (dm_suspended_md(md) || dm_suspended_internally_md(md))
+ return;
+
+ set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
+ synchronize_srcu(&md->io_barrier);
+ flush_workqueue(md->wq);
+ dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
+
+void dm_internal_resume_fast(struct mapped_device *md)
+{
+ if (dm_suspended_md(md) || dm_suspended_internally_md(md))
+ goto done;
+
+ dm_queue_flush(md);
+
+done:
+ mutex_unlock(&md->suspend_lock);
+}
+EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
+
+/*-----------------------------------------------------------------
+ * Event notification.
+ *---------------------------------------------------------------*/
+int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
+ unsigned cookie)
+{
+ int r;
+ unsigned noio_flag;
+ char udev_cookie[DM_COOKIE_LENGTH];
+ char *envp[] = { udev_cookie, NULL };
+
+ noio_flag = memalloc_noio_save();
+
+ if (!cookie)
+ r = kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
+ else {
+ snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
+ DM_COOKIE_ENV_VAR_NAME, cookie);
+ r = kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
+ action, envp);
+ }
+
+ memalloc_noio_restore(noio_flag);
+
+ return r;
+}
+
+uint32_t dm_next_uevent_seq(struct mapped_device *md)
+{
+ return atomic_add_return(1, &md->uevent_seq);
+}
+
+uint32_t dm_get_event_nr(struct mapped_device *md)
+{
+ return atomic_read(&md->event_nr);
+}
+
+int dm_wait_event(struct mapped_device *md, int event_nr)
+{
+ return wait_event_interruptible(md->eventq,
+ (event_nr != atomic_read(&md->event_nr)));
+}
+
+void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&md->uevent_lock, flags);
+ list_add(elist, &md->uevent_list);
+ spin_unlock_irqrestore(&md->uevent_lock, flags);
+}
+
+/*
+ * The gendisk is only valid as long as you have a reference
+ * count on 'md'.
+ */
+struct gendisk *dm_disk(struct mapped_device *md)
+{
+ return md->disk;
+}
+EXPORT_SYMBOL_GPL(dm_disk);
+
+struct kobject *dm_kobject(struct mapped_device *md)
+{
+ return &md->kobj_holder.kobj;
+}
+
+struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
+{
+ struct mapped_device *md;
+
+ md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
+
+ spin_lock(&_minor_lock);
+ if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
+ md = NULL;
+ goto out;
+ }
+ dm_get(md);
+out:
+ spin_unlock(&_minor_lock);
+
+ return md;
+}
+
+int dm_suspended_md(struct mapped_device *md)
+{
+ return test_bit(DMF_SUSPENDED, &md->flags);
+}
+
+int dm_suspended_internally_md(struct mapped_device *md)
+{
+ return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
+}
+
+int dm_test_deferred_remove_flag(struct mapped_device *md)
+{
+ return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
+}
+
+int dm_suspended(struct dm_target *ti)
+{
+ return dm_suspended_md(dm_table_get_md(ti->table));
+}
+EXPORT_SYMBOL_GPL(dm_suspended);
+
+int dm_noflush_suspending(struct dm_target *ti)
+{
+ return __noflush_suspending(dm_table_get_md(ti->table));
+}
+EXPORT_SYMBOL_GPL(dm_noflush_suspending);
+
+struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
+ unsigned integrity, unsigned per_io_data_size)
+{
+ struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
+ unsigned int pool_size = 0;
+ unsigned int front_pad;
+
+ if (!pools)
+ return NULL;
+
+ switch (type) {
+ case DM_TYPE_BIO_BASED:
+ case DM_TYPE_DAX_BIO_BASED:
+ pool_size = dm_get_reserved_bio_based_ios();
+ front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
+
+ pools->io_pool = mempool_create_slab_pool(pool_size, _io_cache);
+ if (!pools->io_pool)
+ goto out;
+ break;
+ case DM_TYPE_REQUEST_BASED:
+ case DM_TYPE_MQ_REQUEST_BASED:
+ pool_size = dm_get_reserved_rq_based_ios();
+ front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
+ /* per_io_data_size is used for blk-mq pdu at queue allocation */
+ break;
+ default:
+ BUG();
+ }
+
+ pools->bs = bioset_create(pool_size, front_pad, BIOSET_NEED_RESCUER);
+ if (!pools->bs)
+ goto out;
+
+ if (integrity && bioset_integrity_create(pools->bs, pool_size))
+ goto out;
+
+ return pools;
+
+out:
+ dm_free_md_mempools(pools);
+
+ return NULL;
+}
+
+void dm_free_md_mempools(struct dm_md_mempools *pools)
+{
+ if (!pools)
+ return;
+
+ mempool_destroy(pools->io_pool);
+
+ if (pools->bs)
+ bioset_free(pools->bs);
+
+ kfree(pools);
+}
+
+struct dm_pr {
+ u64 old_key;
+ u64 new_key;
+ u32 flags;
+ bool fail_early;
+};
+
+static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
+ void *data)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ struct dm_table *table;
+ struct dm_target *ti;
+ int ret = -ENOTTY, srcu_idx;
+
+ table = dm_get_live_table(md, &srcu_idx);
+ if (!table || !dm_table_get_size(table))
+ goto out;
+
+ /* We only support devices that have a single target */
+ if (dm_table_get_num_targets(table) != 1)
+ goto out;
+ ti = dm_table_get_target(table, 0);
+
+ ret = -EINVAL;
+ if (!ti->type->iterate_devices)
+ goto out;
+
+ ret = ti->type->iterate_devices(ti, fn, data);
+out:
+ dm_put_live_table(md, srcu_idx);
+ return ret;
+}
+
+/*
+ * For register / unregister we need to manually call out to every path.
+ */
+static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data)
+{
+ struct dm_pr *pr = data;
+ const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
+
+ if (!ops || !ops->pr_register)
+ return -EOPNOTSUPP;
+ return ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
+}
+
+static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
+ u32 flags)
+{
+ struct dm_pr pr = {
+ .old_key = old_key,
+ .new_key = new_key,
+ .flags = flags,
+ .fail_early = true,
+ };
+ int ret;
+
+ ret = dm_call_pr(bdev, __dm_pr_register, &pr);
+ if (ret && new_key) {
+ /* unregister all paths if we failed to register any path */
+ pr.old_key = new_key;
+ pr.new_key = 0;
+ pr.flags = 0;
+ pr.fail_early = false;
+ dm_call_pr(bdev, __dm_pr_register, &pr);
+ }
+
+ return ret;
+}
+
+static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
+ u32 flags)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ const struct pr_ops *ops;
+ fmode_t mode;
+ int r;
+
+ r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
+ if (r < 0)
+ return r;
+
+ ops = bdev->bd_disk->fops->pr_ops;
+ if (ops && ops->pr_reserve)
+ r = ops->pr_reserve(bdev, key, type, flags);
+ else
+ r = -EOPNOTSUPP;
+
+ bdput(bdev);
+ return r;
+}
+
+static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ const struct pr_ops *ops;
+ fmode_t mode;
+ int r;
+
+ r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
+ if (r < 0)
+ return r;
+
+ ops = bdev->bd_disk->fops->pr_ops;
+ if (ops && ops->pr_release)
+ r = ops->pr_release(bdev, key, type);
+ else
+ r = -EOPNOTSUPP;
+
+ bdput(bdev);
+ return r;
+}
+
+static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
+ enum pr_type type, bool abort)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ const struct pr_ops *ops;
+ fmode_t mode;
+ int r;
+
+ r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
+ if (r < 0)
+ return r;
+
+ ops = bdev->bd_disk->fops->pr_ops;
+ if (ops && ops->pr_preempt)
+ r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
+ else
+ r = -EOPNOTSUPP;
+
+ bdput(bdev);
+ return r;
+}
+
+static int dm_pr_clear(struct block_device *bdev, u64 key)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+ const struct pr_ops *ops;
+ fmode_t mode;
+ int r;
+
+ r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
+ if (r < 0)
+ return r;
+
+ ops = bdev->bd_disk->fops->pr_ops;
+ if (ops && ops->pr_clear)
+ r = ops->pr_clear(bdev, key);
+ else
+ r = -EOPNOTSUPP;
+
+ bdput(bdev);
+ return r;
+}
+
+static const struct pr_ops dm_pr_ops = {
+ .pr_register = dm_pr_register,
+ .pr_reserve = dm_pr_reserve,
+ .pr_release = dm_pr_release,
+ .pr_preempt = dm_pr_preempt,
+ .pr_clear = dm_pr_clear,
+};
+
+static const struct block_device_operations dm_blk_dops = {
+ .open = dm_blk_open,
+ .release = dm_blk_close,
+ .ioctl = dm_blk_ioctl,
+ .getgeo = dm_blk_getgeo,
+ .pr_ops = &dm_pr_ops,
+ .owner = THIS_MODULE
+};
+
+static const struct dax_operations dm_dax_ops = {
+ .direct_access = dm_dax_direct_access,
+ .copy_from_iter = dm_dax_copy_from_iter,
+};
+
+/*
+ * module hooks
+ */
+module_init(dm_init);
+module_exit(dm_exit);
+
+module_param(major, uint, 0);
+MODULE_PARM_DESC(major, "The major number of the device mapper");
+
+module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
+
+module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
+
+MODULE_DESCRIPTION(DM_NAME " driver");
+MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
+MODULE_LICENSE("GPL");