/*
* Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
- * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include "dm.h"
-#include "dm-bio-list.h"
#include "dm-uevent.h"
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/hdreg.h>
-#include <linux/blktrace_api.h>
-#include <trace/block.h>
+
+#include <trace/events/block.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 DEFINE_SPINLOCK(_minor_lock);
/*
+ * For bio-based dm.
* One of these is allocated per bio.
*/
struct dm_io {
atomic_t io_count;
struct bio *bio;
unsigned long start_time;
+ spinlock_t endio_lock;
};
/*
+ * For bio-based dm.
* One of these is allocated per target within a bio. Hopefully
* this will be simplified out one day.
*/
union map_info info;
};
-DEFINE_TRACE(block_bio_complete);
+/*
+ * For request-based dm.
+ * One of these is allocated per request.
+ */
+struct dm_rq_target_io {
+ struct mapped_device *md;
+ struct dm_target *ti;
+ struct request *orig, clone;
+ int error;
+ union map_info info;
+};
+
+/*
+ * For request-based dm.
+ * One of these is allocated per bio.
+ */
+struct dm_rq_clone_bio_info {
+ struct bio *orig;
+ struct dm_rq_target_io *tio;
+};
union map_info *dm_get_mapinfo(struct bio *bio)
{
return NULL;
}
+union map_info *dm_get_rq_mapinfo(struct request *rq)
+{
+ if (rq && rq->end_io_data)
+ return &((struct dm_rq_target_io *)rq->end_io_data)->info;
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo);
+
#define MINOR_ALLOCED ((void *)-1)
/*
* Bits for the md->flags field.
*/
-#define DMF_BLOCK_IO 0
+#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_QUEUE_IO_TO_THREAD 6
/*
* Work processed by per-device workqueue.
*/
-struct dm_wq_req {
- enum {
- DM_WQ_FLUSH_DEFERRED,
- } type;
- struct work_struct work;
- struct mapped_device *md;
- void *context;
-};
-
struct mapped_device {
struct rw_semaphore io_lock;
struct mutex suspend_lock;
- spinlock_t pushback_lock;
rwlock_t map_lock;
atomic_t holders;
atomic_t open_count;
/*
* A list of ios that arrived while we were suspended.
*/
- atomic_t pending;
+ atomic_t pending[2];
wait_queue_head_t wait;
+ struct work_struct work;
struct bio_list deferred;
- struct bio_list pushback;
+ spinlock_t deferred_lock;
+
+ /*
+ * An error from the barrier request currently being processed.
+ */
+ int barrier_error;
+
+ /*
+ * Protect barrier_error from concurrent endio processing
+ * in request-based dm.
+ */
+ spinlock_t barrier_error_lock;
/*
* Processing queue (flush/barriers)
*/
struct workqueue_struct *wq;
+ struct work_struct barrier_work;
+
+ /* A pointer to the currently processing pre/post flush request */
+ struct request *flush_request;
/*
* The current mapping.
* freeze/thaw support require holding onto a super block
*/
struct super_block *frozen_sb;
- struct block_device *suspended_bdev;
+ struct block_device *bdev;
/* forced geometry settings */
struct hd_geometry geometry;
+
+ /* For saving the address of __make_request for request based dm */
+ make_request_fn *saved_make_request_fn;
+
+ /* sysfs handle */
+ struct kobject kobj;
+
+ /* zero-length barrier that will be cloned and submitted to targets */
+ struct bio barrier_bio;
+};
+
+/*
+ * For mempools pre-allocation at the table loading time.
+ */
+struct dm_md_mempools {
+ mempool_t *io_pool;
+ mempool_t *tio_pool;
+ struct bio_set *bs;
};
#define MIN_IOS 256
static struct kmem_cache *_io_cache;
static struct kmem_cache *_tio_cache;
+static struct kmem_cache *_rq_tio_cache;
+static struct kmem_cache *_rq_bio_info_cache;
static int __init local_init(void)
{
if (!_tio_cache)
goto out_free_io_cache;
+ _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
+ if (!_rq_tio_cache)
+ goto out_free_tio_cache;
+
+ _rq_bio_info_cache = KMEM_CACHE(dm_rq_clone_bio_info, 0);
+ if (!_rq_bio_info_cache)
+ goto out_free_rq_tio_cache;
+
r = dm_uevent_init();
if (r)
- goto out_free_tio_cache;
+ goto out_free_rq_bio_info_cache;
_major = major;
r = register_blkdev(_major, _name);
out_uevent_exit:
dm_uevent_exit();
+out_free_rq_bio_info_cache:
+ kmem_cache_destroy(_rq_bio_info_cache);
+out_free_rq_tio_cache:
+ kmem_cache_destroy(_rq_tio_cache);
out_free_tio_cache:
kmem_cache_destroy(_tio_cache);
out_free_io_cache:
static void local_exit(void)
{
+ kmem_cache_destroy(_rq_bio_info_cache);
+ kmem_cache_destroy(_rq_tio_cache);
kmem_cache_destroy(_tio_cache);
kmem_cache_destroy(_io_cache);
unregister_blkdev(_major, _name);
dm_target_init,
dm_linear_init,
dm_stripe_init,
+ dm_io_init,
dm_kcopyd_init,
dm_interface_init,
};
dm_target_exit,
dm_linear_exit,
dm_stripe_exit,
+ dm_io_exit,
dm_kcopyd_exit,
dm_interface_exit,
};
/*
* 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;
goto out;
if (test_bit(DMF_FREEING, &md->flags) ||
- test_bit(DMF_DELETING, &md->flags)) {
+ dm_deleting_md(md)) {
md = NULL;
goto out;
}
unsigned int cmd, unsigned long arg)
{
struct mapped_device *md = bdev->bd_disk->private_data;
- struct dm_table *map = dm_get_table(md);
+ struct dm_table *map = dm_get_live_table(md);
struct dm_target *tgt;
int r = -ENOTTY;
tgt = dm_table_get_target(map, 0);
- if (dm_suspended(md)) {
+ if (dm_suspended_md(md)) {
r = -EAGAIN;
goto out;
}
mempool_free(io, md->io_pool);
}
-static struct dm_target_io *alloc_tio(struct mapped_device *md)
+static void free_tio(struct mapped_device *md, struct dm_target_io *tio)
{
- return mempool_alloc(md->tio_pool, GFP_NOIO);
+ mempool_free(tio, md->tio_pool);
}
-static void free_tio(struct mapped_device *md, struct dm_target_io *tio)
+static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md,
+ gfp_t gfp_mask)
{
- mempool_free(tio, md->tio_pool);
+ return mempool_alloc(md->tio_pool, gfp_mask);
+}
+
+static void free_rq_tio(struct dm_rq_target_io *tio)
+{
+ mempool_free(tio, tio->md->tio_pool);
+}
+
+static struct dm_rq_clone_bio_info *alloc_bio_info(struct mapped_device *md)
+{
+ return mempool_alloc(md->io_pool, GFP_ATOMIC);
+}
+
+static void free_bio_info(struct dm_rq_clone_bio_info *info)
+{
+ mempool_free(info, info->tio->md->io_pool);
+}
+
+static 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;
int cpu;
+ int rw = bio_data_dir(io->bio);
io->start_time = jiffies;
cpu = part_stat_lock();
part_round_stats(cpu, &dm_disk(md)->part0);
part_stat_unlock();
- dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending);
+ dm_disk(md)->part0.in_flight[rw] = atomic_inc_return(&md->pending[rw]);
}
static void end_io_acct(struct dm_io *io)
part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration);
part_stat_unlock();
- dm_disk(md)->part0.in_flight = pending =
- atomic_dec_return(&md->pending);
+ /*
+ * After this is decremented the bio must not be touched if it is
+ * a barrier.
+ */
+ dm_disk(md)->part0.in_flight[rw] = pending =
+ atomic_dec_return(&md->pending[rw]);
+ pending += atomic_read(&md->pending[rw^0x1]);
/* nudge anyone waiting on suspend queue */
if (!pending)
/*
* Add the bio to the list of deferred io.
*/
-static int queue_io(struct mapped_device *md, struct bio *bio)
+static void queue_io(struct mapped_device *md, struct bio *bio)
{
down_write(&md->io_lock);
- if (!test_bit(DMF_BLOCK_IO, &md->flags)) {
- up_write(&md->io_lock);
- return 1;
- }
-
+ spin_lock_irq(&md->deferred_lock);
bio_list_add(&md->deferred, bio);
+ spin_unlock_irq(&md->deferred_lock);
+
+ if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags))
+ queue_work(md->wq, &md->work);
up_write(&md->io_lock);
- return 0; /* deferred successfully */
}
/*
* function to access the md->map field, and make sure they call
* dm_table_put() when finished.
*/
-struct dm_table *dm_get_table(struct mapped_device *md)
+struct dm_table *dm_get_live_table(struct mapped_device *md)
{
struct dm_table *t;
+ unsigned long flags;
- read_lock(&md->map_lock);
+ read_lock_irqsave(&md->map_lock, flags);
t = md->map;
if (t)
dm_table_get(t);
- read_unlock(&md->map_lock);
+ read_unlock_irqrestore(&md->map_lock, flags);
return t;
}
static void dec_pending(struct dm_io *io, int error)
{
unsigned long flags;
+ int io_error;
+ struct bio *bio;
+ struct mapped_device *md = io->md;
/* Push-back supersedes any I/O errors */
- if (error && !(io->error > 0 && __noflush_suspending(io->md)))
- io->error = error;
+ if (unlikely(error)) {
+ spin_lock_irqsave(&io->endio_lock, flags);
+ if (!(io->error > 0 && __noflush_suspending(md)))
+ io->error = error;
+ spin_unlock_irqrestore(&io->endio_lock, flags);
+ }
if (atomic_dec_and_test(&io->io_count)) {
if (io->error == DM_ENDIO_REQUEUE) {
/*
* Target requested pushing back the I/O.
- * This must be handled before the sleeper on
- * suspend queue merges the pushback list.
*/
- spin_lock_irqsave(&io->md->pushback_lock, flags);
- if (__noflush_suspending(io->md))
- bio_list_add(&io->md->pushback, io->bio);
- else
+ spin_lock_irqsave(&md->deferred_lock, flags);
+ if (__noflush_suspending(md)) {
+ if (!bio_rw_flagged(io->bio, BIO_RW_BARRIER))
+ bio_list_add_head(&md->deferred,
+ io->bio);
+ } else
/* noflush suspend was interrupted. */
io->error = -EIO;
- spin_unlock_irqrestore(&io->md->pushback_lock, flags);
+ spin_unlock_irqrestore(&md->deferred_lock, flags);
}
- end_io_acct(io);
+ io_error = io->error;
+ bio = io->bio;
- if (io->error != DM_ENDIO_REQUEUE) {
- trace_block_bio_complete(io->md->queue, io->bio);
-
- bio_endio(io->bio, io->error);
+ if (bio_rw_flagged(bio, BIO_RW_BARRIER)) {
+ /*
+ * There can be just one barrier request so we use
+ * a per-device variable for error reporting.
+ * Note that you can't touch the bio after end_io_acct
+ */
+ if (!md->barrier_error && io_error != -EOPNOTSUPP)
+ md->barrier_error = io_error;
+ end_io_acct(io);
+ free_io(md, io);
+ } else {
+ end_io_acct(io);
+ free_io(md, io);
+
+ if (io_error != DM_ENDIO_REQUEUE) {
+ trace_block_bio_complete(md->queue, bio);
+
+ bio_endio(bio, io_error);
+ }
}
-
- free_io(io->md, io);
}
}
{
int r = 0;
struct dm_target_io *tio = bio->bi_private;
+ struct dm_io *io = tio->io;
struct mapped_device *md = tio->io->md;
dm_endio_fn endio = tio->ti->type->end_io;
}
}
- dec_pending(tio->io, error);
-
/*
* Store md for cleanup instead of tio which is about to get freed.
*/
bio->bi_private = md->bs;
- bio_put(bio);
free_tio(md, tio);
+ bio_put(bio);
+ dec_pending(io, error);
+}
+
+/*
+ * Partial completion handling for request-based dm
+ */
+static void end_clone_bio(struct bio *clone, int error)
+{
+ struct dm_rq_clone_bio_info *info = clone->bi_private;
+ struct dm_rq_target_io *tio = info->tio;
+ struct bio *bio = info->orig;
+ unsigned int nr_bytes = info->orig->bi_size;
+
+ bio_put(clone);
+
+ if (tio->error)
+ /*
+ * An error has already been detected on the request.
+ * Once error occurred, just let clone->end_io() handle
+ * the remainder.
+ */
+ return;
+ else if (error) {
+ /*
+ * Don't notice the error to the upper layer yet.
+ * The error handling decision is made by the target driver,
+ * when the request is completed.
+ */
+ tio->error = error;
+ return;
+ }
+
+ /*
+ * I/O for the bio successfully completed.
+ * Notice the data completion to the upper layer.
+ */
+
+ /*
+ * bios are processed from the head of the list.
+ * So the completing bio should always be rq->bio.
+ * If it's not, something wrong is happening.
+ */
+ if (tio->orig->bio != bio)
+ DMERR("bio completion is going in the middle of the request");
+
+ /*
+ * Update the original request.
+ * Do not use blk_end_request() here, because it may complete
+ * the original request before the clone, and break the ordering.
+ */
+ blk_update_request(tio->orig, 0, nr_bytes);
+}
+
+static void store_barrier_error(struct mapped_device *md, int error)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&md->barrier_error_lock, flags);
+ /*
+ * Basically, the first error is taken, but:
+ * -EOPNOTSUPP supersedes any I/O error.
+ * Requeue request supersedes any I/O error but -EOPNOTSUPP.
+ */
+ if (!md->barrier_error || error == -EOPNOTSUPP ||
+ (md->barrier_error != -EOPNOTSUPP &&
+ error == DM_ENDIO_REQUEUE))
+ md->barrier_error = error;
+ spin_unlock_irqrestore(&md->barrier_error_lock, flags);
+}
+
+/*
+ * Don't touch any member of the md after calling this function because
+ * the md may be freed in dm_put() at the end of this function.
+ * Or do dm_get() before calling this function and dm_put() later.
+ */
+static void rq_completed(struct mapped_device *md, int rw, int run_queue)
+{
+ atomic_dec(&md->pending[rw]);
+
+ /* nudge anyone waiting on suspend queue */
+ if (!md_in_flight(md))
+ wake_up(&md->wait);
+
+ if (run_queue)
+ blk_run_queue(md->queue);
+
+ /*
+ * dm_put() must be at the end of this function. See the comment above
+ */
+ dm_put(md);
+}
+
+static void free_rq_clone(struct request *clone)
+{
+ struct dm_rq_target_io *tio = clone->end_io_data;
+
+ blk_rq_unprep_clone(clone);
+ free_rq_tio(tio);
+}
+
+/*
+ * Complete the clone and the original request.
+ * Must be called without queue lock.
+ */
+static void dm_end_request(struct request *clone, int error)
+{
+ int rw = rq_data_dir(clone);
+ int run_queue = 1;
+ bool is_barrier = blk_barrier_rq(clone);
+ struct dm_rq_target_io *tio = clone->end_io_data;
+ struct mapped_device *md = tio->md;
+ struct request *rq = tio->orig;
+
+ if (blk_pc_request(rq) && !is_barrier) {
+ rq->errors = clone->errors;
+ rq->resid_len = clone->resid_len;
+
+ if (rq->sense)
+ /*
+ * We are using the sense buffer of the original
+ * request.
+ * So setting the length of the sense data is enough.
+ */
+ rq->sense_len = clone->sense_len;
+ }
+
+ free_rq_clone(clone);
+
+ if (unlikely(is_barrier)) {
+ if (unlikely(error))
+ store_barrier_error(md, error);
+ run_queue = 0;
+ } else
+ blk_end_request_all(rq, error);
+
+ rq_completed(md, rw, run_queue);
+}
+
+static void dm_unprep_request(struct request *rq)
+{
+ struct request *clone = rq->special;
+
+ rq->special = NULL;
+ rq->cmd_flags &= ~REQ_DONTPREP;
+
+ free_rq_clone(clone);
+}
+
+/*
+ * Requeue the original request of a clone.
+ */
+void dm_requeue_unmapped_request(struct request *clone)
+{
+ int rw = rq_data_dir(clone);
+ struct dm_rq_target_io *tio = clone->end_io_data;
+ struct mapped_device *md = tio->md;
+ struct request *rq = tio->orig;
+ struct request_queue *q = rq->q;
+ unsigned long flags;
+
+ if (unlikely(blk_barrier_rq(clone))) {
+ /*
+ * Barrier clones share an original request.
+ * Leave it to dm_end_request(), which handles this special
+ * case.
+ */
+ dm_end_request(clone, DM_ENDIO_REQUEUE);
+ return;
+ }
+
+ dm_unprep_request(rq);
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ if (elv_queue_empty(q))
+ blk_plug_device(q);
+ blk_requeue_request(q, rq);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ rq_completed(md, rw, 0);
+}
+EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request);
+
+static void __stop_queue(struct request_queue *q)
+{
+ blk_stop_queue(q);
+}
+
+static void stop_queue(struct request_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ __stop_queue(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+
+static void __start_queue(struct request_queue *q)
+{
+ if (blk_queue_stopped(q))
+ blk_start_queue(q);
+}
+
+static void start_queue(struct request_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ __start_queue(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+
+static void dm_done(struct request *clone, int error, bool mapped)
+{
+ int r = error;
+ struct dm_rq_target_io *tio = clone->end_io_data;
+ dm_request_endio_fn rq_end_io = tio->ti->type->rq_end_io;
+
+ if (mapped && rq_end_io)
+ r = rq_end_io(tio->ti, clone, error, &tio->info);
+
+ if (r <= 0)
+ /* The target wants to complete the I/O */
+ dm_end_request(clone, r);
+ else if (r == DM_ENDIO_INCOMPLETE)
+ /* The target will handle the I/O */
+ return;
+ else if (r == DM_ENDIO_REQUEUE)
+ /* The target wants to requeue the I/O */
+ dm_requeue_unmapped_request(clone);
+ else {
+ DMWARN("unimplemented target endio return value: %d", r);
+ BUG();
+ }
+}
+
+/*
+ * Request completion handler for request-based dm
+ */
+static void dm_softirq_done(struct request *rq)
+{
+ bool mapped = true;
+ struct request *clone = rq->completion_data;
+ struct dm_rq_target_io *tio = clone->end_io_data;
+
+ if (rq->cmd_flags & REQ_FAILED)
+ mapped = false;
+
+ dm_done(clone, tio->error, mapped);
+}
+
+/*
+ * Complete the clone and the original request with the error status
+ * through softirq context.
+ */
+static void dm_complete_request(struct request *clone, int error)
+{
+ struct dm_rq_target_io *tio = clone->end_io_data;
+ struct request *rq = tio->orig;
+
+ if (unlikely(blk_barrier_rq(clone))) {
+ /*
+ * Barrier clones share an original request. So can't use
+ * softirq_done with the original.
+ * Pass the clone to dm_done() directly in this special case.
+ * It is safe (even if clone->q->queue_lock is held here)
+ * because there is no I/O dispatching during the completion
+ * of barrier clone.
+ */
+ dm_done(clone, error, true);
+ return;
+ }
+
+ tio->error = error;
+ rq->completion_data = clone;
+ blk_complete_request(rq);
+}
+
+/*
+ * Complete the not-mapped clone and the original request with the error status
+ * through softirq context.
+ * Target's rq_end_io() function isn't called.
+ * This may be used when the target's map_rq() function fails.
+ */
+void dm_kill_unmapped_request(struct request *clone, int error)
+{
+ struct dm_rq_target_io *tio = clone->end_io_data;
+ struct request *rq = tio->orig;
+
+ if (unlikely(blk_barrier_rq(clone))) {
+ /*
+ * Barrier clones share an original request.
+ * Leave it to dm_end_request(), which handles this special
+ * case.
+ */
+ BUG_ON(error > 0);
+ dm_end_request(clone, error);
+ return;
+ }
+
+ rq->cmd_flags |= REQ_FAILED;
+ dm_complete_request(clone, error);
+}
+EXPORT_SYMBOL_GPL(dm_kill_unmapped_request);
+
+/*
+ * Called with the queue lock held
+ */
+static void end_clone_request(struct request *clone, int error)
+{
+ /*
+ * For just cleaning up the information of the queue in which
+ * the clone was dispatched.
+ * The clone is *NOT* freed actually here because it is alloced from
+ * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags.
+ */
+ __blk_put_request(clone->q, clone);
+
+ /*
+ * Actual request completion is done in a softirq context which doesn't
+ * hold the queue lock. Otherwise, deadlock could occur because:
+ * - another request may be submitted by the upper level driver
+ * of the stacking during the completion
+ * - the submission which requires queue lock may be done
+ * against this queue
+ */
+ dm_complete_request(clone, error);
}
static sector_t max_io_len(struct mapped_device *md,
sector_t sector;
struct mapped_device *md;
- /*
- * Sanity checks.
- */
- BUG_ON(!clone->bi_size);
-
clone->bi_end_io = clone_endio;
clone->bi_private = tio;
/* the bio has been remapped so dispatch it */
trace_block_remap(bdev_get_queue(clone->bi_bdev), clone,
- tio->io->bio->bi_bdev->bd_dev,
- clone->bi_sector, sector);
+ tio->io->bio->bi_bdev->bd_dev, sector);
generic_make_request(clone);
} else if (r < 0 || r == DM_MAPIO_REQUEUE) {
clone->bi_sector = sector;
clone->bi_bdev = bio->bi_bdev;
- clone->bi_rw = bio->bi_rw;
+ clone->bi_rw = bio->bi_rw & ~(1 << BIO_RW_BARRIER);
clone->bi_vcnt = 1;
clone->bi_size = to_bytes(len);
clone->bi_io_vec->bv_offset = offset;
clone->bi_io_vec->bv_len = clone->bi_size;
clone->bi_flags |= 1 << BIO_CLONED;
+ if (bio_integrity(bio)) {
+ bio_integrity_clone(clone, bio, GFP_NOIO, bs);
+ bio_integrity_trim(clone,
+ bio_sector_offset(bio, idx, offset), len);
+ }
+
return clone;
}
clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
__bio_clone(clone, bio);
+ clone->bi_rw &= ~(1 << BIO_RW_BARRIER);
clone->bi_destructor = dm_bio_destructor;
clone->bi_sector = sector;
clone->bi_idx = idx;
clone->bi_size = to_bytes(len);
clone->bi_flags &= ~(1 << BIO_SEG_VALID);
+ if (bio_integrity(bio)) {
+ bio_integrity_clone(clone, bio, GFP_NOIO, bs);
+
+ if (idx != bio->bi_idx || clone->bi_size < bio->bi_size)
+ bio_integrity_trim(clone,
+ bio_sector_offset(bio, idx, 0), len);
+ }
+
return clone;
}
-static int __clone_and_map(struct clone_info *ci)
+static struct dm_target_io *alloc_tio(struct clone_info *ci,
+ struct dm_target *ti)
{
- struct bio *clone, *bio = ci->bio;
- struct dm_target *ti;
- sector_t len = 0, max;
- struct dm_target_io *tio;
-
- ti = dm_table_find_target(ci->map, ci->sector);
- if (!dm_target_is_valid(ti))
- return -EIO;
-
- max = max_io_len(ci->md, ci->sector, ti);
+ struct dm_target_io *tio = mempool_alloc(ci->md->tio_pool, GFP_NOIO);
- /*
- * Allocate a target io object.
- */
- tio = alloc_tio(ci->md);
tio->io = ci->io;
tio->ti = ti;
memset(&tio->info, 0, sizeof(tio->info));
- if (ci->sector_count <= max) {
- /*
- * Optimise for the simple case where we can do all of
- * the remaining io with a single clone.
- */
- clone = clone_bio(bio, ci->sector, ci->idx,
- bio->bi_vcnt - ci->idx, ci->sector_count,
- ci->md->bs);
+ return tio;
+}
+
+static void __flush_target(struct clone_info *ci, struct dm_target *ti,
+ unsigned flush_nr)
+{
+ struct dm_target_io *tio = alloc_tio(ci, ti);
+ struct bio *clone;
+
+ tio->info.flush_request = flush_nr;
+
+ clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
+ __bio_clone(clone, ci->bio);
+ clone->bi_destructor = dm_bio_destructor;
+
+ __map_bio(ti, clone, tio);
+}
+
+static int __clone_and_map_empty_barrier(struct clone_info *ci)
+{
+ unsigned target_nr = 0, flush_nr;
+ struct dm_target *ti;
+
+ while ((ti = dm_table_get_target(ci->map, target_nr++)))
+ for (flush_nr = 0; flush_nr < ti->num_flush_requests;
+ flush_nr++)
+ __flush_target(ci, ti, flush_nr);
+
+ ci->sector_count = 0;
+
+ return 0;
+}
+
+static int __clone_and_map(struct clone_info *ci)
+{
+ struct bio *clone, *bio = ci->bio;
+ struct dm_target *ti;
+ sector_t len = 0, max;
+ struct dm_target_io *tio;
+
+ if (unlikely(bio_empty_barrier(bio)))
+ return __clone_and_map_empty_barrier(ci);
+
+ ti = dm_table_find_target(ci->map, ci->sector);
+ if (!dm_target_is_valid(ti))
+ return -EIO;
+
+ max = max_io_len(ci->md, ci->sector, ti);
+
+ /*
+ * Allocate a target io object.
+ */
+ tio = alloc_tio(ci, ti);
+
+ if (ci->sector_count <= max) {
+ /*
+ * Optimise for the simple case where we can do all of
+ * the remaining io with a single clone.
+ */
+ clone = clone_bio(bio, ci->sector, ci->idx,
+ bio->bi_vcnt - ci->idx, ci->sector_count,
+ ci->md->bs);
__map_bio(ti, clone, tio);
ci->sector_count = 0;
max = max_io_len(ci->md, ci->sector, ti);
- tio = alloc_tio(ci->md);
- tio->io = ci->io;
- tio->ti = ti;
- memset(&tio->info, 0, sizeof(tio->info));
+ tio = alloc_tio(ci, ti);
}
len = min(remaining, max);
}
/*
- * Split the bio into several clones.
+ * Split the bio into several clones and submit it to targets.
*/
-static int __split_bio(struct mapped_device *md, struct bio *bio)
+static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
{
struct clone_info ci;
int error = 0;
- ci.map = dm_get_table(md);
- if (unlikely(!ci.map))
- return -EIO;
+ ci.map = dm_get_live_table(md);
+ if (unlikely(!ci.map)) {
+ if (!bio_rw_flagged(bio, BIO_RW_BARRIER))
+ bio_io_error(bio);
+ else
+ if (!md->barrier_error)
+ md->barrier_error = -EIO;
+ return;
+ }
ci.md = md;
ci.bio = bio;
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_sector;
ci.sector_count = bio_sectors(bio);
+ if (unlikely(bio_empty_barrier(bio)))
+ ci.sector_count = 1;
ci.idx = bio->bi_idx;
start_io_acct(ci.io);
/* drop the extra reference count */
dec_pending(ci.io, error);
dm_table_put(ci.map);
-
- return 0;
}
/*-----------------------------------------------------------------
* CRUD END
struct bio_vec *biovec)
{
struct mapped_device *md = q->queuedata;
- struct dm_table *map = dm_get_table(md);
+ struct dm_table *map = dm_get_live_table(md);
struct dm_target *ti;
sector_t max_sectors;
int max_size = 0;
*/
if (max_size && ti->type->merge)
max_size = ti->type->merge(ti, bvm, biovec, max_size);
+ /*
+ * If the target doesn't support merge method and some of the devices
+ * provided their merge_bvec method (we know this by looking at
+ * queue_max_hw_sectors), then we can't allow bios with multiple vector
+ * entries. So always set max_size to 0, and the code below allows
+ * just one page.
+ */
+ else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9)
+
+ max_size = 0;
out_table:
dm_table_put(map);
* The request function that just remaps the bio built up by
* dm_merge_bvec.
*/
-static int dm_request(struct request_queue *q, struct bio *bio)
+static int _dm_request(struct request_queue *q, struct bio *bio)
{
- int r = -EIO;
int rw = bio_data_dir(bio);
struct mapped_device *md = q->queuedata;
int cpu;
- /*
- * There is no use in forwarding any barrier request since we can't
- * guarantee it is (or can be) handled by the targets correctly.
- */
- if (unlikely(bio_barrier(bio))) {
- bio_endio(bio, -EOPNOTSUPP);
- return 0;
- }
-
down_read(&md->io_lock);
cpu = part_stat_lock();
part_stat_unlock();
/*
- * If we're suspended we have to queue
- * this io for later.
+ * If we're suspended or the thread is processing barriers
+ * we have to queue this io for later.
*/
- while (test_bit(DMF_BLOCK_IO, &md->flags)) {
+ if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
+ unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
up_read(&md->io_lock);
- if (bio_rw(bio) != READA)
- r = queue_io(md, bio);
+ if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
+ bio_rw(bio) == READA) {
+ bio_io_error(bio);
+ return 0;
+ }
- if (r <= 0)
- goto out_req;
+ queue_io(md, bio);
- /*
- * We're in a while loop, because someone could suspend
- * before we get to the following read lock.
- */
- down_read(&md->io_lock);
+ return 0;
}
- r = __split_bio(md, bio);
+ __split_and_process_bio(md, bio);
up_read(&md->io_lock);
+ return 0;
+}
-out_req:
- if (r < 0)
- bio_io_error(bio);
+static int dm_make_request(struct request_queue *q, struct bio *bio)
+{
+ struct mapped_device *md = q->queuedata;
+
+ return md->saved_make_request_fn(q, bio); /* call __make_request() */
+}
+
+static int dm_request_based(struct mapped_device *md)
+{
+ return blk_queue_stackable(md->queue);
+}
+
+static int dm_request(struct request_queue *q, struct bio *bio)
+{
+ struct mapped_device *md = q->queuedata;
+
+ if (dm_request_based(md))
+ return dm_make_request(q, bio);
+
+ return _dm_request(q, bio);
+}
+
+/*
+ * Mark this request as flush request, so that dm_request_fn() can
+ * recognize.
+ */
+static void dm_rq_prepare_flush(struct request_queue *q, struct request *rq)
+{
+ rq->cmd_type = REQ_TYPE_LINUX_BLOCK;
+ rq->cmd[0] = REQ_LB_OP_FLUSH;
+}
+
+static bool dm_rq_is_flush_request(struct request *rq)
+{
+ if (rq->cmd_type == REQ_TYPE_LINUX_BLOCK &&
+ rq->cmd[0] == REQ_LB_OP_FLUSH)
+ return true;
+ else
+ return false;
+}
+
+void dm_dispatch_request(struct request *rq)
+{
+ int r;
+
+ if (blk_queue_io_stat(rq->q))
+ rq->cmd_flags |= REQ_IO_STAT;
+
+ rq->start_time = jiffies;
+ r = blk_insert_cloned_request(rq->q, rq);
+ if (r)
+ dm_complete_request(rq, r);
+}
+EXPORT_SYMBOL_GPL(dm_dispatch_request);
+
+static void dm_rq_bio_destructor(struct bio *bio)
+{
+ struct dm_rq_clone_bio_info *info = bio->bi_private;
+ struct mapped_device *md = info->tio->md;
+
+ free_bio_info(info);
+ bio_free(bio, md->bs);
+}
+
+static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig,
+ void *data)
+{
+ struct dm_rq_target_io *tio = data;
+ struct mapped_device *md = tio->md;
+ struct dm_rq_clone_bio_info *info = alloc_bio_info(md);
+
+ if (!info)
+ return -ENOMEM;
+
+ info->orig = bio_orig;
+ info->tio = tio;
+ bio->bi_end_io = end_clone_bio;
+ bio->bi_private = info;
+ bio->bi_destructor = dm_rq_bio_destructor;
return 0;
}
+static int setup_clone(struct request *clone, struct request *rq,
+ struct dm_rq_target_io *tio)
+{
+ int r;
+
+ if (dm_rq_is_flush_request(rq)) {
+ blk_rq_init(NULL, clone);
+ clone->cmd_type = REQ_TYPE_FS;
+ clone->cmd_flags |= (REQ_HARDBARRIER | WRITE);
+ } else {
+ r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
+ dm_rq_bio_constructor, tio);
+ if (r)
+ return r;
+
+ clone->cmd = rq->cmd;
+ clone->cmd_len = rq->cmd_len;
+ clone->sense = rq->sense;
+ clone->buffer = rq->buffer;
+ }
+
+ clone->end_io = end_clone_request;
+ clone->end_io_data = tio;
+
+ return 0;
+}
+
+static struct request *clone_rq(struct request *rq, struct mapped_device *md,
+ gfp_t gfp_mask)
+{
+ struct request *clone;
+ struct dm_rq_target_io *tio;
+
+ tio = alloc_rq_tio(md, gfp_mask);
+ if (!tio)
+ return NULL;
+
+ tio->md = md;
+ tio->ti = NULL;
+ tio->orig = rq;
+ tio->error = 0;
+ memset(&tio->info, 0, sizeof(tio->info));
+
+ clone = &tio->clone;
+ if (setup_clone(clone, rq, tio)) {
+ /* -ENOMEM */
+ free_rq_tio(tio);
+ return NULL;
+ }
+
+ return clone;
+}
+
+/*
+ * Called with the queue lock held.
+ */
+static int dm_prep_fn(struct request_queue *q, struct request *rq)
+{
+ struct mapped_device *md = q->queuedata;
+ struct request *clone;
+
+ if (unlikely(dm_rq_is_flush_request(rq)))
+ return BLKPREP_OK;
+
+ if (unlikely(rq->special)) {
+ DMWARN("Already has something in rq->special.");
+ return BLKPREP_KILL;
+ }
+
+ clone = clone_rq(rq, md, GFP_ATOMIC);
+ if (!clone)
+ return BLKPREP_DEFER;
+
+ rq->special = clone;
+ rq->cmd_flags |= REQ_DONTPREP;
+
+ return BLKPREP_OK;
+}
+
+/*
+ * Returns:
+ * 0 : the request has been processed (not requeued)
+ * !0 : the request has been requeued
+ */
+static int map_request(struct dm_target *ti, struct request *clone,
+ struct mapped_device *md)
+{
+ int r, requeued = 0;
+ struct dm_rq_target_io *tio = clone->end_io_data;
+
+ /*
+ * Hold the md reference here for the in-flight I/O.
+ * We can't rely on the reference count by device opener,
+ * because the device may be closed during the request completion
+ * when all bios are completed.
+ * See the comment in rq_completed() too.
+ */
+ dm_get(md);
+
+ tio->ti = ti;
+ r = ti->type->map_rq(ti, clone, &tio->info);
+ switch (r) {
+ case DM_MAPIO_SUBMITTED:
+ /* The target has taken the I/O to submit by itself later */
+ break;
+ case DM_MAPIO_REMAPPED:
+ /* The target has remapped the I/O so dispatch it */
+ trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
+ blk_rq_pos(tio->orig));
+ dm_dispatch_request(clone);
+ break;
+ case DM_MAPIO_REQUEUE:
+ /* The target wants to requeue the I/O */
+ dm_requeue_unmapped_request(clone);
+ requeued = 1;
+ break;
+ default:
+ if (r > 0) {
+ DMWARN("unimplemented target map return value: %d", r);
+ BUG();
+ }
+
+ /* The target wants to complete the I/O */
+ dm_kill_unmapped_request(clone, r);
+ break;
+ }
+
+ return requeued;
+}
+
+/*
+ * q->request_fn for request-based dm.
+ * Called with the queue lock held.
+ */
+static void dm_request_fn(struct request_queue *q)
+{
+ struct mapped_device *md = q->queuedata;
+ struct dm_table *map = dm_get_live_table(md);
+ struct dm_target *ti;
+ struct request *rq, *clone;
+
+ /*
+ * For suspend, check blk_queue_stopped() and increment
+ * ->pending within a single queue_lock not to increment the
+ * number of in-flight I/Os after the queue is stopped in
+ * dm_suspend().
+ */
+ while (!blk_queue_plugged(q) && !blk_queue_stopped(q)) {
+ rq = blk_peek_request(q);
+ if (!rq)
+ goto plug_and_out;
+
+ if (unlikely(dm_rq_is_flush_request(rq))) {
+ BUG_ON(md->flush_request);
+ md->flush_request = rq;
+ blk_start_request(rq);
+ queue_work(md->wq, &md->barrier_work);
+ goto out;
+ }
+
+ ti = dm_table_find_target(map, blk_rq_pos(rq));
+ if (ti->type->busy && ti->type->busy(ti))
+ goto plug_and_out;
+
+ blk_start_request(rq);
+ clone = rq->special;
+ atomic_inc(&md->pending[rq_data_dir(clone)]);
+
+ spin_unlock(q->queue_lock);
+ if (map_request(ti, clone, md))
+ goto requeued;
+
+ spin_lock_irq(q->queue_lock);
+ }
+
+ goto out;
+
+requeued:
+ spin_lock_irq(q->queue_lock);
+
+plug_and_out:
+ if (!elv_queue_empty(q))
+ /* Some requests still remain, retry later */
+ blk_plug_device(q);
+
+out:
+ dm_table_put(map);
+
+ return;
+}
+
+int dm_underlying_device_busy(struct request_queue *q)
+{
+ return blk_lld_busy(q);
+}
+EXPORT_SYMBOL_GPL(dm_underlying_device_busy);
+
+static int dm_lld_busy(struct request_queue *q)
+{
+ int r;
+ struct mapped_device *md = q->queuedata;
+ struct dm_table *map = dm_get_live_table(md);
+
+ if (!map || test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))
+ r = 1;
+ else
+ r = dm_table_any_busy_target(map);
+
+ dm_table_put(map);
+
+ return r;
+}
+
static void dm_unplug_all(struct request_queue *q)
{
struct mapped_device *md = q->queuedata;
- struct dm_table *map = dm_get_table(md);
+ struct dm_table *map = dm_get_live_table(md);
if (map) {
+ if (dm_request_based(md))
+ generic_unplug_device(q);
+
dm_table_unplug_all(map);
dm_table_put(map);
}
struct mapped_device *md = congested_data;
struct dm_table *map;
- atomic_inc(&md->pending);
-
- if (!test_bit(DMF_BLOCK_IO, &md->flags)) {
- map = dm_get_table(md);
+ if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
+ map = dm_get_live_table(md);
if (map) {
- r = dm_table_any_congested(map, bdi_bits);
+ /*
+ * Request-based dm cares about only own queue for
+ * the query about congestion status of request_queue
+ */
+ if (dm_request_based(md))
+ r = md->queue->backing_dev_info.state &
+ bdi_bits;
+ else
+ r = dm_table_any_congested(map, bdi_bits);
+
dm_table_put(map);
}
}
- if (!atomic_dec_return(&md->pending))
- /* nudge anyone waiting on suspend queue */
- wake_up(&md->wait);
-
return r;
}
return r;
}
-static struct block_device_operations dm_blk_dops;
+static const struct block_device_operations dm_blk_dops;
+
+static void dm_wq_work(struct work_struct *work);
+static void dm_rq_barrier_work(struct work_struct *work);
/*
* Allocate and initialise a blank device with a given minor.
init_rwsem(&md->io_lock);
mutex_init(&md->suspend_lock);
- spin_lock_init(&md->pushback_lock);
+ spin_lock_init(&md->deferred_lock);
+ spin_lock_init(&md->barrier_error_lock);
rwlock_init(&md->map_lock);
atomic_set(&md->holders, 1);
atomic_set(&md->open_count, 0);
INIT_LIST_HEAD(&md->uevent_list);
spin_lock_init(&md->uevent_lock);
- md->queue = blk_alloc_queue(GFP_KERNEL);
+ md->queue = blk_init_queue(dm_request_fn, NULL);
if (!md->queue)
goto bad_queue;
+ /*
+ * Request-based dm devices cannot be stacked on top of bio-based dm
+ * devices. The type of this dm device has not been decided yet,
+ * although we initialized the queue using blk_init_queue().
+ * 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);
+ md->saved_make_request_fn = md->queue->make_request_fn;
md->queue->queuedata = md;
md->queue->backing_dev_info.congested_fn = dm_any_congested;
md->queue->backing_dev_info.congested_data = md;
blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
md->queue->unplug_fn = dm_unplug_all;
blk_queue_merge_bvec(md->queue, dm_merge_bvec);
-
- md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache);
- if (!md->io_pool)
- goto bad_io_pool;
-
- md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache);
- if (!md->tio_pool)
- goto bad_tio_pool;
-
- md->bs = bioset_create(16, 16);
- if (!md->bs)
- goto bad_no_bioset;
+ blk_queue_softirq_done(md->queue, dm_softirq_done);
+ blk_queue_prep_rq(md->queue, dm_prep_fn);
+ blk_queue_lld_busy(md->queue, dm_lld_busy);
+ blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN_FLUSH,
+ dm_rq_prepare_flush);
md->disk = alloc_disk(1);
if (!md->disk)
goto bad_disk;
- atomic_set(&md->pending, 0);
+ 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_WORK(&md->barrier_work, dm_rq_barrier_work);
init_waitqueue_head(&md->eventq);
md->disk->major = _major;
if (!md->wq)
goto bad_thread;
+ md->bdev = bdget_disk(md->disk, 0);
+ if (!md->bdev)
+ goto bad_bdev;
+
/* Populate the mapping, nobody knows we exist yet */
spin_lock(&_minor_lock);
old_md = idr_replace(&_minor_idr, md, minor);
return md;
+bad_bdev:
+ destroy_workqueue(md->wq);
bad_thread:
+ del_gendisk(md->disk);
put_disk(md->disk);
bad_disk:
- bioset_free(md->bs);
-bad_no_bioset:
- mempool_destroy(md->tio_pool);
-bad_tio_pool:
- mempool_destroy(md->io_pool);
-bad_io_pool:
blk_cleanup_queue(md->queue);
bad_queue:
free_minor(minor);
{
int minor = MINOR(disk_devt(md->disk));
- if (md->suspended_bdev) {
- unlock_fs(md);
- bdput(md->suspended_bdev);
- }
+ unlock_fs(md);
+ bdput(md->bdev);
destroy_workqueue(md->wq);
- mempool_destroy(md->tio_pool);
- mempool_destroy(md->io_pool);
- bioset_free(md->bs);
+ if (md->tio_pool)
+ mempool_destroy(md->tio_pool);
+ if (md->io_pool)
+ mempool_destroy(md->io_pool);
+ if (md->bs)
+ bioset_free(md->bs);
+ blk_integrity_unregister(md->disk);
del_gendisk(md->disk);
free_minor(minor);
kfree(md);
}
+static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
+{
+ struct dm_md_mempools *p;
+
+ if (md->io_pool && md->tio_pool && md->bs)
+ /* the md already has necessary mempools */
+ goto out;
+
+ p = dm_table_get_md_mempools(t);
+ BUG_ON(!p || md->io_pool || md->tio_pool || md->bs);
+
+ md->io_pool = p->io_pool;
+ p->io_pool = NULL;
+ md->tio_pool = p->tio_pool;
+ p->tio_pool = NULL;
+ md->bs = p->bs;
+ p->bs = NULL;
+
+out:
+ /* mempool bind completed, now no need any mempools in the table */
+ dm_table_free_md_mempools(t);
+}
+
/*
* Bind a table to the device.
*/
{
set_capacity(md->disk, size);
- mutex_lock(&md->suspended_bdev->bd_inode->i_mutex);
- i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
- mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex);
+ mutex_lock(&md->bdev->bd_inode->i_mutex);
+ i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
+ mutex_unlock(&md->bdev->bd_inode->i_mutex);
}
-static int __bind(struct mapped_device *md, struct dm_table *t)
+/*
+ * 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;
+ unsigned long flags;
size = dm_table_get_size(t);
if (size != get_capacity(md->disk))
memset(&md->geometry, 0, sizeof(md->geometry));
- if (md->suspended_bdev)
- __set_size(md, size);
- if (size == 0)
- return 0;
+ __set_size(md, size);
- dm_table_get(t);
dm_table_event_callback(t, event_callback, md);
- write_lock(&md->map_lock);
+ /*
+ * 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) && !blk_queue_stopped(q))
+ stop_queue(q);
+
+ __bind_mempools(md, t);
+
+ write_lock_irqsave(&md->map_lock, flags);
+ old_map = md->map;
md->map = t;
- dm_table_set_restrictions(t, q);
- write_unlock(&md->map_lock);
+ dm_table_set_restrictions(t, q, limits);
+ write_unlock_irqrestore(&md->map_lock, flags);
- return 0;
+ return old_map;
}
-static void __unbind(struct mapped_device *md)
+/*
+ * Returns unbound table for the caller to free.
+ */
+static struct dm_table *__unbind(struct mapped_device *md)
{
struct dm_table *map = md->map;
+ unsigned long flags;
if (!map)
- return;
+ return NULL;
dm_table_event_callback(map, NULL, NULL);
- write_lock(&md->map_lock);
+ write_lock_irqsave(&md->map_lock, flags);
md->map = NULL;
- write_unlock(&md->map_lock);
- dm_table_put(map);
+ write_unlock_irqrestore(&md->map_lock, flags);
+
+ return map;
}
/*
if (!md)
return -ENXIO;
+ dm_sysfs_init(md);
+
*result = md;
return 0;
}
BUG_ON(test_bit(DMF_FREEING, &md->flags));
if (atomic_dec_and_lock(&md->holders, &_minor_lock)) {
- map = dm_get_table(md);
+ map = dm_get_live_table(md);
idr_replace(&_minor_idr, MINOR_ALLOCED,
MINOR(disk_devt(dm_disk(md))));
set_bit(DMF_FREEING, &md->flags);
spin_unlock(&_minor_lock);
- if (!dm_suspended(md)) {
+ if (!dm_suspended_md(md)) {
dm_table_presuspend_targets(map);
dm_table_postsuspend_targets(map);
}
- __unbind(md);
+ dm_sysfs_exit(md);
dm_table_put(map);
+ dm_table_destroy(__unbind(md));
free_dev(md);
}
}
EXPORT_SYMBOL_GPL(dm_put);
-static int dm_wait_for_completion(struct mapped_device *md)
+static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
{
int r = 0;
+ DECLARE_WAITQUEUE(wait, current);
+
+ dm_unplug_all(md->queue);
+
+ add_wait_queue(&md->wait, &wait);
while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
+ set_current_state(interruptible);
smp_mb();
- if (!atomic_read(&md->pending))
+ if (!md_in_flight(md))
break;
- if (signal_pending(current)) {
+ if (interruptible == TASK_INTERRUPTIBLE &&
+ signal_pending(current)) {
r = -EINTR;
break;
}
}
set_current_state(TASK_RUNNING);
+ remove_wait_queue(&md->wait, &wait);
+
return r;
}
-/*
- * Process the deferred bios
- */
-static void __flush_deferred_io(struct mapped_device *md)
+static void dm_flush(struct mapped_device *md)
{
- struct bio *c;
+ dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
- while ((c = bio_list_pop(&md->deferred))) {
- if (__split_bio(md, c))
- bio_io_error(c);
- }
+ bio_init(&md->barrier_bio);
+ md->barrier_bio.bi_bdev = md->bdev;
+ md->barrier_bio.bi_rw = WRITE_BARRIER;
+ __split_and_process_bio(md, &md->barrier_bio);
- clear_bit(DMF_BLOCK_IO, &md->flags);
+ dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
}
-static void __merge_pushback_list(struct mapped_device *md)
+static void process_barrier(struct mapped_device *md, struct bio *bio)
{
- unsigned long flags;
+ md->barrier_error = 0;
+
+ dm_flush(md);
- spin_lock_irqsave(&md->pushback_lock, flags);
- clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
- bio_list_merge_head(&md->deferred, &md->pushback);
- bio_list_init(&md->pushback);
- spin_unlock_irqrestore(&md->pushback_lock, flags);
+ if (!bio_empty_barrier(bio)) {
+ __split_and_process_bio(md, bio);
+ dm_flush(md);
+ }
+
+ if (md->barrier_error != DM_ENDIO_REQUEUE)
+ bio_endio(bio, md->barrier_error);
+ else {
+ spin_lock_irq(&md->deferred_lock);
+ bio_list_add_head(&md->deferred, bio);
+ spin_unlock_irq(&md->deferred_lock);
+ }
}
+/*
+ * Process the deferred bios
+ */
static void dm_wq_work(struct work_struct *work)
{
- struct dm_wq_req *req = container_of(work, struct dm_wq_req, work);
- struct mapped_device *md = req->md;
+ struct mapped_device *md = container_of(work, struct mapped_device,
+ work);
+ struct bio *c;
down_write(&md->io_lock);
- switch (req->type) {
- case DM_WQ_FLUSH_DEFERRED:
- __flush_deferred_io(md);
- break;
- default:
- DMERR("dm_wq_work: unrecognised work type %d", req->type);
- BUG();
+
+ 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) {
+ clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
+ break;
+ }
+
+ up_write(&md->io_lock);
+
+ if (dm_request_based(md))
+ generic_make_request(c);
+ else {
+ if (bio_rw_flagged(c, BIO_RW_BARRIER))
+ process_barrier(md, c);
+ else
+ __split_and_process_bio(md, c);
+ }
+
+ down_write(&md->io_lock);
}
+
up_write(&md->io_lock);
}
-static void dm_wq_queue(struct mapped_device *md, int type, void *context,
- struct dm_wq_req *req)
+static void dm_queue_flush(struct mapped_device *md)
{
- req->type = type;
- req->md = md;
- req->context = context;
- INIT_WORK(&req->work, dm_wq_work);
- queue_work(md->wq, &req->work);
+ clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
+ smp_mb__after_clear_bit();
+ queue_work(md->wq, &md->work);
}
-static void dm_queue_flush(struct mapped_device *md, int type, void *context)
+static void dm_rq_set_flush_nr(struct request *clone, unsigned flush_nr)
{
- struct dm_wq_req req;
+ struct dm_rq_target_io *tio = clone->end_io_data;
- dm_wq_queue(md, type, context, &req);
- flush_workqueue(md->wq);
+ tio->info.flush_request = flush_nr;
+}
+
+/* Issue barrier requests to targets and wait for their completion. */
+static int dm_rq_barrier(struct mapped_device *md)
+{
+ int i, j;
+ struct dm_table *map = dm_get_live_table(md);
+ unsigned num_targets = dm_table_get_num_targets(map);
+ struct dm_target *ti;
+ struct request *clone;
+
+ md->barrier_error = 0;
+
+ for (i = 0; i < num_targets; i++) {
+ ti = dm_table_get_target(map, i);
+ for (j = 0; j < ti->num_flush_requests; j++) {
+ clone = clone_rq(md->flush_request, md, GFP_NOIO);
+ dm_rq_set_flush_nr(clone, j);
+ atomic_inc(&md->pending[rq_data_dir(clone)]);
+ map_request(ti, clone, md);
+ }
+ }
+
+ dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
+ dm_table_put(map);
+
+ return md->barrier_error;
+}
+
+static void dm_rq_barrier_work(struct work_struct *work)
+{
+ int error;
+ struct mapped_device *md = container_of(work, struct mapped_device,
+ barrier_work);
+ struct request_queue *q = md->queue;
+ struct request *rq;
+ unsigned long flags;
+
+ /*
+ * Hold the md reference here and leave it at the last part so that
+ * the md can't be deleted by device opener when the barrier request
+ * completes.
+ */
+ dm_get(md);
+
+ error = dm_rq_barrier(md);
+
+ rq = md->flush_request;
+ md->flush_request = NULL;
+
+ if (error == DM_ENDIO_REQUEUE) {
+ spin_lock_irqsave(q->queue_lock, flags);
+ blk_requeue_request(q, rq);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ } else
+ blk_end_request_all(rq, error);
+
+ blk_run_queue(q);
+
+ dm_put(md);
}
/*
- * Swap in a new table (destroying old one).
+ * Swap in a new table, returning the old one for the caller to destroy.
*/
-int dm_swap_table(struct mapped_device *md, struct dm_table *table)
+struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
{
- int r = -EINVAL;
+ struct dm_table *map = ERR_PTR(-EINVAL);
+ struct queue_limits limits;
+ int r;
mutex_lock(&md->suspend_lock);
/* device must be suspended */
- if (!dm_suspended(md))
+ if (!dm_suspended_md(md))
goto out;
- /* without bdev, the device size cannot be changed */
- if (!md->suspended_bdev)
- if (get_capacity(md->disk) != dm_table_get_size(table))
- goto out;
+ r = dm_calculate_queue_limits(table, &limits);
+ if (r) {
+ map = ERR_PTR(r);
+ goto out;
+ }
- __unbind(md);
- r = __bind(md, table);
+ /* cannot change the device type, once a table is bound */
+ if (md->map &&
+ (dm_table_get_type(md->map) != dm_table_get_type(table))) {
+ DMWARN("can't change the device type after a table is bound");
+ goto out;
+ }
+
+ map = __bind(md, table, &limits);
out:
mutex_unlock(&md->suspend_lock);
- return r;
+ return map;
}
/*
WARN_ON(md->frozen_sb);
- md->frozen_sb = freeze_bdev(md->suspended_bdev);
+ md->frozen_sb = freeze_bdev(md->bdev);
if (IS_ERR(md->frozen_sb)) {
r = PTR_ERR(md->frozen_sb);
md->frozen_sb = NULL;
set_bit(DMF_FROZEN, &md->flags);
- /* don't bdput right now, we don't want the bdev
- * to go away while it is locked.
- */
return 0;
}
if (!test_bit(DMF_FROZEN, &md->flags))
return;
- thaw_bdev(md->suspended_bdev, md->frozen_sb);
+ thaw_bdev(md->bdev, md->frozen_sb);
md->frozen_sb = NULL;
clear_bit(DMF_FROZEN, &md->flags);
}
* 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;
- DECLARE_WAITQUEUE(wait, current);
int r = 0;
int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0;
int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0;
mutex_lock(&md->suspend_lock);
- if (dm_suspended(md)) {
+ if (dm_suspended_md(md)) {
r = -EINVAL;
goto out_unlock;
}
- map = dm_get_table(md);
+ map = dm_get_live_table(md);
/*
* DMF_NOFLUSH_SUSPENDING must be set before presuspend.
/* This does not get reverted if there's an error later. */
dm_table_presuspend_targets(map);
- /* bdget() can stall if the pending I/Os are not flushed */
- if (!noflush) {
- md->suspended_bdev = bdget_disk(md->disk, 0);
- if (!md->suspended_bdev) {
- DMWARN("bdget failed in dm_suspend");
- r = -ENOMEM;
+ /*
+ * 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)
goto out;
- }
-
- /*
- * Flush I/O to the device. noflush supersedes do_lockfs,
- * because lock_fs() needs to flush I/Os.
- */
- if (do_lockfs) {
- r = lock_fs(md);
- if (r)
- goto out;
- }
}
/*
- * First we set the BLOCK_IO flag so no more ios will be mapped.
+ * 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, we set
+ * DMF_QUEUE_IO_TO_THREAD.
+ *
+ * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND
+ * and call flush_workqueue(md->wq). flush_workqueue will wait until
+ * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any
+ * further calls to __split_and_process_bio from dm_wq_work.
*/
down_write(&md->io_lock);
- set_bit(DMF_BLOCK_IO, &md->flags);
-
- add_wait_queue(&md->wait, &wait);
+ set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
+ set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
up_write(&md->io_lock);
- /* unplug */
- if (map)
- dm_table_unplug_all(map);
+ /*
+ * Request-based dm uses md->wq for barrier (dm_rq_barrier_work) which
+ * can be kicked until md->queue is stopped. So stop md->queue before
+ * flushing md->wq.
+ */
+ if (dm_request_based(md))
+ stop_queue(md->queue);
+
+ flush_workqueue(md->wq);
/*
- * Wait for the already-mapped ios to complete.
+ * 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);
+ r = dm_wait_for_completion(md, TASK_INTERRUPTIBLE);
down_write(&md->io_lock);
- remove_wait_queue(&md->wait, &wait);
-
if (noflush)
- __merge_pushback_list(md);
+ clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
up_write(&md->io_lock);
/* were we interrupted ? */
if (r < 0) {
- dm_queue_flush(md, DM_WQ_FLUSH_DEFERRED, NULL);
+ dm_queue_flush(md);
+
+ if (dm_request_based(md))
+ start_queue(md->queue);
unlock_fs(md);
goto out; /* pushback list is already flushed, so skip flush */
}
- dm_table_postsuspend_targets(map);
+ /*
+ * If dm_wait_for_completion returned 0, the device is completely
+ * quiescent now. There is no request-processing activity. All new
+ * requests are being added to md->deferred list.
+ */
set_bit(DMF_SUSPENDED, &md->flags);
-out:
- if (r && md->suspended_bdev) {
- bdput(md->suspended_bdev);
- md->suspended_bdev = NULL;
- }
+ dm_table_postsuspend_targets(map);
+out:
dm_table_put(map);
out_unlock:
struct dm_table *map = NULL;
mutex_lock(&md->suspend_lock);
- if (!dm_suspended(md))
+ if (!dm_suspended_md(md))
goto out;
- map = dm_get_table(md);
+ map = dm_get_live_table(md);
if (!map || !dm_table_get_size(map))
goto out;
if (r)
goto out;
- dm_queue_flush(md, DM_WQ_FLUSH_DEFERRED, NULL);
+ dm_queue_flush(md);
- unlock_fs(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))
+ start_queue(md->queue);
- if (md->suspended_bdev) {
- bdput(md->suspended_bdev);
- md->suspended_bdev = NULL;
- }
+ unlock_fs(md);
clear_bit(DMF_SUSPENDED, &md->flags);
dm_table_unplug_all(map);
-
- dm_kobject_uevent(md);
-
r = 0;
-
out:
dm_table_put(map);
mutex_unlock(&md->suspend_lock);
/*-----------------------------------------------------------------
* Event notification.
*---------------------------------------------------------------*/
-void dm_kobject_uevent(struct mapped_device *md)
-{
- kobject_uevent(&disk_to_dev(md->disk)->kobj, KOBJ_CHANGE);
+int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
+ unsigned cookie)
+{
+ char udev_cookie[DM_COOKIE_LENGTH];
+ char *envp[] = { udev_cookie, NULL };
+
+ if (!cookie)
+ return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
+ else {
+ snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
+ DM_COOKIE_ENV_VAR_NAME, cookie);
+ return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
+ action, envp);
+ }
}
uint32_t dm_next_uevent_seq(struct mapped_device *md)
return md->disk;
}
-int dm_suspended(struct mapped_device *md)
+struct kobject *dm_kobject(struct mapped_device *md)
+{
+ return &md->kobj;
+}
+
+/*
+ * struct mapped_device should not be exported outside of dm.c
+ * so use this check to verify that kobj is part of md structure
+ */
+struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
+{
+ struct mapped_device *md;
+
+ md = container_of(kobj, struct mapped_device, kobj);
+ if (&md->kobj != kobj)
+ return NULL;
+
+ if (test_bit(DMF_FREEING, &md->flags) ||
+ dm_deleting_md(md))
+ return NULL;
+
+ dm_get(md);
+ return md;
+}
+
+int dm_suspended_md(struct mapped_device *md)
{
return test_bit(DMF_SUSPENDED, &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)
{
- struct mapped_device *md = dm_table_get_md(ti->table);
- int r = __noflush_suspending(md);
+ return __noflush_suspending(dm_table_get_md(ti->table));
+}
+EXPORT_SYMBOL_GPL(dm_noflush_suspending);
- dm_put(md);
+struct dm_md_mempools *dm_alloc_md_mempools(unsigned type)
+{
+ struct dm_md_mempools *pools = kmalloc(sizeof(*pools), GFP_KERNEL);
- return r;
+ if (!pools)
+ return NULL;
+
+ pools->io_pool = (type == DM_TYPE_BIO_BASED) ?
+ mempool_create_slab_pool(MIN_IOS, _io_cache) :
+ mempool_create_slab_pool(MIN_IOS, _rq_bio_info_cache);
+ if (!pools->io_pool)
+ goto free_pools_and_out;
+
+ pools->tio_pool = (type == DM_TYPE_BIO_BASED) ?
+ mempool_create_slab_pool(MIN_IOS, _tio_cache) :
+ mempool_create_slab_pool(MIN_IOS, _rq_tio_cache);
+ if (!pools->tio_pool)
+ goto free_io_pool_and_out;
+
+ pools->bs = (type == DM_TYPE_BIO_BASED) ?
+ bioset_create(16, 0) : bioset_create(MIN_IOS, 0);
+ if (!pools->bs)
+ goto free_tio_pool_and_out;
+
+ return pools;
+
+free_tio_pool_and_out:
+ mempool_destroy(pools->tio_pool);
+
+free_io_pool_and_out:
+ mempool_destroy(pools->io_pool);
+
+free_pools_and_out:
+ kfree(pools);
+
+ return NULL;
+}
+
+void dm_free_md_mempools(struct dm_md_mempools *pools)
+{
+ if (!pools)
+ return;
+
+ if (pools->io_pool)
+ mempool_destroy(pools->io_pool);
+
+ if (pools->tio_pool)
+ mempool_destroy(pools->tio_pool);
+
+ if (pools->bs)
+ bioset_free(pools->bs);
+
+ kfree(pools);
}
-EXPORT_SYMBOL_GPL(dm_noflush_suspending);
-static struct block_device_operations dm_blk_dops = {
+static const struct block_device_operations dm_blk_dops = {
.open = dm_blk_open,
.release = dm_blk_close,
.ioctl = dm_blk_ioctl,
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff