2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This file is released under the GPL.
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/moduleparam.h>
15 #include <linux/blkpg.h>
16 #include <linux/bio.h>
17 #include <linux/mempool.h>
18 #include <linux/slab.h>
19 #include <linux/idr.h>
20 #include <linux/hdreg.h>
21 #include <linux/delay.h>
23 #include <trace/events/block.h>
25 #define DM_MSG_PREFIX "core"
29 * ratelimit state to be used in DMXXX_LIMIT().
31 DEFINE_RATELIMIT_STATE(dm_ratelimit_state
,
32 DEFAULT_RATELIMIT_INTERVAL
,
33 DEFAULT_RATELIMIT_BURST
);
34 EXPORT_SYMBOL(dm_ratelimit_state
);
38 * Cookies are numeric values sent with CHANGE and REMOVE
39 * uevents while resuming, removing or renaming the device.
41 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
42 #define DM_COOKIE_LENGTH 24
44 static const char *_name
= DM_NAME
;
46 static unsigned int major
= 0;
47 static unsigned int _major
= 0;
49 static DEFINE_IDR(_minor_idr
);
51 static DEFINE_SPINLOCK(_minor_lock
);
54 * One of these is allocated per bio.
57 struct mapped_device
*md
;
61 unsigned long start_time
;
62 spinlock_t endio_lock
;
63 struct dm_stats_aux stats_aux
;
67 * For request-based dm.
68 * One of these is allocated per request.
70 struct dm_rq_target_io
{
71 struct mapped_device
*md
;
73 struct request
*orig
, clone
;
79 * For request-based dm - the bio clones we allocate are embedded in these
82 * We allocate these with bio_alloc_bioset, using the front_pad parameter when
83 * the bioset is created - this means the bio has to come at the end of the
86 struct dm_rq_clone_bio_info
{
88 struct dm_rq_target_io
*tio
;
92 union map_info
*dm_get_mapinfo(struct bio
*bio
)
94 if (bio
&& bio
->bi_private
)
95 return &((struct dm_target_io
*)bio
->bi_private
)->info
;
99 union map_info
*dm_get_rq_mapinfo(struct request
*rq
)
101 if (rq
&& rq
->end_io_data
)
102 return &((struct dm_rq_target_io
*)rq
->end_io_data
)->info
;
105 EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo
);
107 #define MINOR_ALLOCED ((void *)-1)
110 * Bits for the md->flags field.
112 #define DMF_BLOCK_IO_FOR_SUSPEND 0
113 #define DMF_SUSPENDED 1
115 #define DMF_FREEING 3
116 #define DMF_DELETING 4
117 #define DMF_NOFLUSH_SUSPENDING 5
118 #define DMF_MERGE_IS_OPTIONAL 6
121 * A dummy definition to make RCU happy.
122 * struct dm_table should never be dereferenced in this file.
129 * Work processed by per-device workqueue.
131 struct mapped_device
{
132 struct srcu_struct io_barrier
;
133 struct mutex suspend_lock
;
138 * The current mapping.
139 * Use dm_get_live_table{_fast} or take suspend_lock for
142 struct dm_table
*map
;
146 struct request_queue
*queue
;
148 /* Protect queue and type against concurrent access. */
149 struct mutex type_lock
;
151 struct target_type
*immutable_target_type
;
153 struct gendisk
*disk
;
159 * A list of ios that arrived while we were suspended.
162 wait_queue_head_t wait
;
163 struct work_struct work
;
164 struct bio_list deferred
;
165 spinlock_t deferred_lock
;
168 * Processing queue (flush)
170 struct workqueue_struct
*wq
;
173 * io objects are allocated from here.
183 wait_queue_head_t eventq
;
185 struct list_head uevent_list
;
186 spinlock_t uevent_lock
; /* Protect access to uevent_list */
189 * freeze/thaw support require holding onto a super block
191 struct super_block
*frozen_sb
;
192 struct block_device
*bdev
;
194 /* forced geometry settings */
195 struct hd_geometry geometry
;
200 /* zero-length flush that will be cloned and submitted to targets */
201 struct bio flush_bio
;
203 struct dm_stats stats
;
207 * For mempools pre-allocation at the table loading time.
209 struct dm_md_mempools
{
214 #define RESERVED_BIO_BASED_IOS 16
215 #define RESERVED_REQUEST_BASED_IOS 256
216 #define RESERVED_MAX_IOS 1024
217 static struct kmem_cache
*_io_cache
;
218 static struct kmem_cache
*_rq_tio_cache
;
221 * Bio-based DM's mempools' reserved IOs set by the user.
223 static unsigned reserved_bio_based_ios
= RESERVED_BIO_BASED_IOS
;
226 * Request-based DM's mempools' reserved IOs set by the user.
228 static unsigned reserved_rq_based_ios
= RESERVED_REQUEST_BASED_IOS
;
230 static unsigned __dm_get_reserved_ios(unsigned *reserved_ios
,
231 unsigned def
, unsigned max
)
233 unsigned ios
= ACCESS_ONCE(*reserved_ios
);
234 unsigned modified_ios
= 0;
242 (void)cmpxchg(reserved_ios
, ios
, modified_ios
);
249 unsigned dm_get_reserved_bio_based_ios(void)
251 return __dm_get_reserved_ios(&reserved_bio_based_ios
,
252 RESERVED_BIO_BASED_IOS
, RESERVED_MAX_IOS
);
254 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios
);
256 unsigned dm_get_reserved_rq_based_ios(void)
258 return __dm_get_reserved_ios(&reserved_rq_based_ios
,
259 RESERVED_REQUEST_BASED_IOS
, RESERVED_MAX_IOS
);
261 EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios
);
263 static int __init
local_init(void)
267 /* allocate a slab for the dm_ios */
268 _io_cache
= KMEM_CACHE(dm_io
, 0);
272 _rq_tio_cache
= KMEM_CACHE(dm_rq_target_io
, 0);
274 goto out_free_io_cache
;
276 r
= dm_uevent_init();
278 goto out_free_rq_tio_cache
;
281 r
= register_blkdev(_major
, _name
);
283 goto out_uevent_exit
;
292 out_free_rq_tio_cache
:
293 kmem_cache_destroy(_rq_tio_cache
);
295 kmem_cache_destroy(_io_cache
);
300 static void local_exit(void)
302 kmem_cache_destroy(_rq_tio_cache
);
303 kmem_cache_destroy(_io_cache
);
304 unregister_blkdev(_major
, _name
);
309 DMINFO("cleaned up");
312 static int (*_inits
[])(void) __initdata
= {
323 static void (*_exits
[])(void) = {
334 static int __init
dm_init(void)
336 const int count
= ARRAY_SIZE(_inits
);
340 for (i
= 0; i
< count
; i
++) {
355 static void __exit
dm_exit(void)
357 int i
= ARRAY_SIZE(_exits
);
363 * Should be empty by this point.
365 idr_destroy(&_minor_idr
);
369 * Block device functions
371 int dm_deleting_md(struct mapped_device
*md
)
373 return test_bit(DMF_DELETING
, &md
->flags
);
376 static int dm_blk_open(struct block_device
*bdev
, fmode_t mode
)
378 struct mapped_device
*md
;
380 spin_lock(&_minor_lock
);
382 md
= bdev
->bd_disk
->private_data
;
386 if (test_bit(DMF_FREEING
, &md
->flags
) ||
387 dm_deleting_md(md
)) {
393 atomic_inc(&md
->open_count
);
396 spin_unlock(&_minor_lock
);
398 return md
? 0 : -ENXIO
;
401 static void dm_blk_close(struct gendisk
*disk
, fmode_t mode
)
403 struct mapped_device
*md
= disk
->private_data
;
405 spin_lock(&_minor_lock
);
407 atomic_dec(&md
->open_count
);
410 spin_unlock(&_minor_lock
);
413 int dm_open_count(struct mapped_device
*md
)
415 return atomic_read(&md
->open_count
);
419 * Guarantees nothing is using the device before it's deleted.
421 int dm_lock_for_deletion(struct mapped_device
*md
)
425 spin_lock(&_minor_lock
);
427 if (dm_open_count(md
))
430 set_bit(DMF_DELETING
, &md
->flags
);
432 spin_unlock(&_minor_lock
);
437 sector_t
dm_get_size(struct mapped_device
*md
)
439 return get_capacity(md
->disk
);
442 struct dm_stats
*dm_get_stats(struct mapped_device
*md
)
447 static int dm_blk_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
449 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
451 return dm_get_geometry(md
, geo
);
454 static int dm_blk_ioctl(struct block_device
*bdev
, fmode_t mode
,
455 unsigned int cmd
, unsigned long arg
)
457 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
459 struct dm_table
*map
;
460 struct dm_target
*tgt
;
464 map
= dm_get_live_table(md
, &srcu_idx
);
466 if (!map
|| !dm_table_get_size(map
))
469 /* We only support devices that have a single target */
470 if (dm_table_get_num_targets(map
) != 1)
473 tgt
= dm_table_get_target(map
, 0);
475 if (dm_suspended_md(md
)) {
480 if (tgt
->type
->ioctl
)
481 r
= tgt
->type
->ioctl(tgt
, cmd
, arg
);
484 dm_put_live_table(md
, srcu_idx
);
486 if (r
== -ENOTCONN
) {
494 static struct dm_io
*alloc_io(struct mapped_device
*md
)
496 return mempool_alloc(md
->io_pool
, GFP_NOIO
);
499 static void free_io(struct mapped_device
*md
, struct dm_io
*io
)
501 mempool_free(io
, md
->io_pool
);
504 static void free_tio(struct mapped_device
*md
, struct dm_target_io
*tio
)
506 bio_put(&tio
->clone
);
509 static struct dm_rq_target_io
*alloc_rq_tio(struct mapped_device
*md
,
512 return mempool_alloc(md
->io_pool
, gfp_mask
);
515 static void free_rq_tio(struct dm_rq_target_io
*tio
)
517 mempool_free(tio
, tio
->md
->io_pool
);
520 static int md_in_flight(struct mapped_device
*md
)
522 return atomic_read(&md
->pending
[READ
]) +
523 atomic_read(&md
->pending
[WRITE
]);
526 static void start_io_acct(struct dm_io
*io
)
528 struct mapped_device
*md
= io
->md
;
529 struct bio
*bio
= io
->bio
;
531 int rw
= bio_data_dir(bio
);
533 io
->start_time
= jiffies
;
535 cpu
= part_stat_lock();
536 part_round_stats(cpu
, &dm_disk(md
)->part0
);
538 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
],
539 atomic_inc_return(&md
->pending
[rw
]));
541 if (unlikely(dm_stats_used(&md
->stats
)))
542 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_sector
,
543 bio_sectors(bio
), false, 0, &io
->stats_aux
);
546 static void end_io_acct(struct dm_io
*io
)
548 struct mapped_device
*md
= io
->md
;
549 struct bio
*bio
= io
->bio
;
550 unsigned long duration
= jiffies
- io
->start_time
;
552 int rw
= bio_data_dir(bio
);
554 cpu
= part_stat_lock();
555 part_round_stats(cpu
, &dm_disk(md
)->part0
);
556 part_stat_add(cpu
, &dm_disk(md
)->part0
, ticks
[rw
], duration
);
559 if (unlikely(dm_stats_used(&md
->stats
)))
560 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_sector
,
561 bio_sectors(bio
), true, duration
, &io
->stats_aux
);
564 * After this is decremented the bio must not be touched if it is
567 pending
= atomic_dec_return(&md
->pending
[rw
]);
568 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
], pending
);
569 pending
+= atomic_read(&md
->pending
[rw
^0x1]);
571 /* nudge anyone waiting on suspend queue */
577 * Add the bio to the list of deferred io.
579 static void queue_io(struct mapped_device
*md
, struct bio
*bio
)
583 spin_lock_irqsave(&md
->deferred_lock
, flags
);
584 bio_list_add(&md
->deferred
, bio
);
585 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
586 queue_work(md
->wq
, &md
->work
);
590 * Everyone (including functions in this file), should use this
591 * function to access the md->map field, and make sure they call
592 * dm_put_live_table() when finished.
594 struct dm_table
*dm_get_live_table(struct mapped_device
*md
, int *srcu_idx
) __acquires(md
->io_barrier
)
596 *srcu_idx
= srcu_read_lock(&md
->io_barrier
);
598 return srcu_dereference(md
->map
, &md
->io_barrier
);
601 void dm_put_live_table(struct mapped_device
*md
, int srcu_idx
) __releases(md
->io_barrier
)
603 srcu_read_unlock(&md
->io_barrier
, srcu_idx
);
606 void dm_sync_table(struct mapped_device
*md
)
608 synchronize_srcu(&md
->io_barrier
);
609 synchronize_rcu_expedited();
613 * A fast alternative to dm_get_live_table/dm_put_live_table.
614 * The caller must not block between these two functions.
616 static struct dm_table
*dm_get_live_table_fast(struct mapped_device
*md
) __acquires(RCU
)
619 return rcu_dereference(md
->map
);
622 static void dm_put_live_table_fast(struct mapped_device
*md
) __releases(RCU
)
628 * Get the geometry associated with a dm device
630 int dm_get_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
638 * Set the geometry of a device.
640 int dm_set_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
642 sector_t sz
= (sector_t
)geo
->cylinders
* geo
->heads
* geo
->sectors
;
644 if (geo
->start
> sz
) {
645 DMWARN("Start sector is beyond the geometry limits.");
654 /*-----------------------------------------------------------------
656 * A more elegant soln is in the works that uses the queue
657 * merge fn, unfortunately there are a couple of changes to
658 * the block layer that I want to make for this. So in the
659 * interests of getting something for people to use I give
660 * you this clearly demarcated crap.
661 *---------------------------------------------------------------*/
663 static int __noflush_suspending(struct mapped_device
*md
)
665 return test_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
669 * Decrements the number of outstanding ios that a bio has been
670 * cloned into, completing the original io if necc.
672 static void dec_pending(struct dm_io
*io
, int error
)
677 struct mapped_device
*md
= io
->md
;
679 /* Push-back supersedes any I/O errors */
680 if (unlikely(error
)) {
681 spin_lock_irqsave(&io
->endio_lock
, flags
);
682 if (!(io
->error
> 0 && __noflush_suspending(md
)))
684 spin_unlock_irqrestore(&io
->endio_lock
, flags
);
687 if (atomic_dec_and_test(&io
->io_count
)) {
688 if (io
->error
== DM_ENDIO_REQUEUE
) {
690 * Target requested pushing back the I/O.
692 spin_lock_irqsave(&md
->deferred_lock
, flags
);
693 if (__noflush_suspending(md
))
694 bio_list_add_head(&md
->deferred
, io
->bio
);
696 /* noflush suspend was interrupted. */
698 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
701 io_error
= io
->error
;
706 if (io_error
== DM_ENDIO_REQUEUE
)
709 if ((bio
->bi_rw
& REQ_FLUSH
) && bio
->bi_size
) {
711 * Preflush done for flush with data, reissue
714 bio
->bi_rw
&= ~REQ_FLUSH
;
717 /* done with normal IO or empty flush */
718 trace_block_bio_complete(md
->queue
, bio
, io_error
);
719 bio_endio(bio
, io_error
);
724 static void clone_endio(struct bio
*bio
, int error
)
727 struct dm_target_io
*tio
= bio
->bi_private
;
728 struct dm_io
*io
= tio
->io
;
729 struct mapped_device
*md
= tio
->io
->md
;
730 dm_endio_fn endio
= tio
->ti
->type
->end_io
;
732 if (!bio_flagged(bio
, BIO_UPTODATE
) && !error
)
736 r
= endio(tio
->ti
, bio
, error
);
737 if (r
< 0 || r
== DM_ENDIO_REQUEUE
)
739 * error and requeue request are handled
743 else if (r
== DM_ENDIO_INCOMPLETE
)
744 /* The target will handle the io */
747 DMWARN("unimplemented target endio return value: %d", r
);
753 dec_pending(io
, error
);
757 * Partial completion handling for request-based dm
759 static void end_clone_bio(struct bio
*clone
, int error
)
761 struct dm_rq_clone_bio_info
*info
= clone
->bi_private
;
762 struct dm_rq_target_io
*tio
= info
->tio
;
763 struct bio
*bio
= info
->orig
;
764 unsigned int nr_bytes
= info
->orig
->bi_size
;
770 * An error has already been detected on the request.
771 * Once error occurred, just let clone->end_io() handle
777 * Don't notice the error to the upper layer yet.
778 * The error handling decision is made by the target driver,
779 * when the request is completed.
786 * I/O for the bio successfully completed.
787 * Notice the data completion to the upper layer.
791 * bios are processed from the head of the list.
792 * So the completing bio should always be rq->bio.
793 * If it's not, something wrong is happening.
795 if (tio
->orig
->bio
!= bio
)
796 DMERR("bio completion is going in the middle of the request");
799 * Update the original request.
800 * Do not use blk_end_request() here, because it may complete
801 * the original request before the clone, and break the ordering.
803 blk_update_request(tio
->orig
, 0, nr_bytes
);
807 * Don't touch any member of the md after calling this function because
808 * the md may be freed in dm_put() at the end of this function.
809 * Or do dm_get() before calling this function and dm_put() later.
811 static void rq_completed(struct mapped_device
*md
, int rw
, int run_queue
)
813 atomic_dec(&md
->pending
[rw
]);
815 /* nudge anyone waiting on suspend queue */
816 if (!md_in_flight(md
))
820 * Run this off this callpath, as drivers could invoke end_io while
821 * inside their request_fn (and holding the queue lock). Calling
822 * back into ->request_fn() could deadlock attempting to grab the
826 blk_run_queue_async(md
->queue
);
829 * dm_put() must be at the end of this function. See the comment above
834 static void free_rq_clone(struct request
*clone
)
836 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
838 blk_rq_unprep_clone(clone
);
843 * Complete the clone and the original request.
844 * Must be called without queue lock.
846 static void dm_end_request(struct request
*clone
, int error
)
848 int rw
= rq_data_dir(clone
);
849 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
850 struct mapped_device
*md
= tio
->md
;
851 struct request
*rq
= tio
->orig
;
853 if (rq
->cmd_type
== REQ_TYPE_BLOCK_PC
) {
854 rq
->errors
= clone
->errors
;
855 rq
->resid_len
= clone
->resid_len
;
859 * We are using the sense buffer of the original
861 * So setting the length of the sense data is enough.
863 rq
->sense_len
= clone
->sense_len
;
866 free_rq_clone(clone
);
867 blk_end_request_all(rq
, error
);
868 rq_completed(md
, rw
, true);
871 static void dm_unprep_request(struct request
*rq
)
873 struct request
*clone
= rq
->special
;
876 rq
->cmd_flags
&= ~REQ_DONTPREP
;
878 free_rq_clone(clone
);
882 * Requeue the original request of a clone.
884 void dm_requeue_unmapped_request(struct request
*clone
)
886 int rw
= rq_data_dir(clone
);
887 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
888 struct mapped_device
*md
= tio
->md
;
889 struct request
*rq
= tio
->orig
;
890 struct request_queue
*q
= rq
->q
;
893 dm_unprep_request(rq
);
895 spin_lock_irqsave(q
->queue_lock
, flags
);
896 blk_requeue_request(q
, rq
);
897 spin_unlock_irqrestore(q
->queue_lock
, flags
);
899 rq_completed(md
, rw
, 0);
901 EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request
);
903 static void __stop_queue(struct request_queue
*q
)
908 static void stop_queue(struct request_queue
*q
)
912 spin_lock_irqsave(q
->queue_lock
, flags
);
914 spin_unlock_irqrestore(q
->queue_lock
, flags
);
917 static void __start_queue(struct request_queue
*q
)
919 if (blk_queue_stopped(q
))
923 static void start_queue(struct request_queue
*q
)
927 spin_lock_irqsave(q
->queue_lock
, flags
);
929 spin_unlock_irqrestore(q
->queue_lock
, flags
);
932 static void dm_done(struct request
*clone
, int error
, bool mapped
)
935 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
936 dm_request_endio_fn rq_end_io
= NULL
;
939 rq_end_io
= tio
->ti
->type
->rq_end_io
;
941 if (mapped
&& rq_end_io
)
942 r
= rq_end_io(tio
->ti
, clone
, error
, &tio
->info
);
946 /* The target wants to complete the I/O */
947 dm_end_request(clone
, r
);
948 else if (r
== DM_ENDIO_INCOMPLETE
)
949 /* The target will handle the I/O */
951 else if (r
== DM_ENDIO_REQUEUE
)
952 /* The target wants to requeue the I/O */
953 dm_requeue_unmapped_request(clone
);
955 DMWARN("unimplemented target endio return value: %d", r
);
961 * Request completion handler for request-based dm
963 static void dm_softirq_done(struct request
*rq
)
966 struct request
*clone
= rq
->completion_data
;
967 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
969 if (rq
->cmd_flags
& REQ_FAILED
)
972 dm_done(clone
, tio
->error
, mapped
);
976 * Complete the clone and the original request with the error status
977 * through softirq context.
979 static void dm_complete_request(struct request
*clone
, int error
)
981 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
982 struct request
*rq
= tio
->orig
;
985 rq
->completion_data
= clone
;
986 blk_complete_request(rq
);
990 * Complete the not-mapped clone and the original request with the error status
991 * through softirq context.
992 * Target's rq_end_io() function isn't called.
993 * This may be used when the target's map_rq() function fails.
995 void dm_kill_unmapped_request(struct request
*clone
, int error
)
997 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
998 struct request
*rq
= tio
->orig
;
1000 rq
->cmd_flags
|= REQ_FAILED
;
1001 dm_complete_request(clone
, error
);
1003 EXPORT_SYMBOL_GPL(dm_kill_unmapped_request
);
1006 * Called with the queue lock held
1008 static void end_clone_request(struct request
*clone
, int error
)
1011 * For just cleaning up the information of the queue in which
1012 * the clone was dispatched.
1013 * The clone is *NOT* freed actually here because it is alloced from
1014 * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags.
1016 __blk_put_request(clone
->q
, clone
);
1019 * Actual request completion is done in a softirq context which doesn't
1020 * hold the queue lock. Otherwise, deadlock could occur because:
1021 * - another request may be submitted by the upper level driver
1022 * of the stacking during the completion
1023 * - the submission which requires queue lock may be done
1024 * against this queue
1026 dm_complete_request(clone
, error
);
1030 * Return maximum size of I/O possible at the supplied sector up to the current
1033 static sector_t
max_io_len_target_boundary(sector_t sector
, struct dm_target
*ti
)
1035 sector_t target_offset
= dm_target_offset(ti
, sector
);
1037 return ti
->len
- target_offset
;
1040 static sector_t
max_io_len(sector_t sector
, struct dm_target
*ti
)
1042 sector_t len
= max_io_len_target_boundary(sector
, ti
);
1043 sector_t offset
, max_len
;
1046 * Does the target need to split even further?
1048 if (ti
->max_io_len
) {
1049 offset
= dm_target_offset(ti
, sector
);
1050 if (unlikely(ti
->max_io_len
& (ti
->max_io_len
- 1)))
1051 max_len
= sector_div(offset
, ti
->max_io_len
);
1053 max_len
= offset
& (ti
->max_io_len
- 1);
1054 max_len
= ti
->max_io_len
- max_len
;
1063 int dm_set_target_max_io_len(struct dm_target
*ti
, sector_t len
)
1065 if (len
> UINT_MAX
) {
1066 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1067 (unsigned long long)len
, UINT_MAX
);
1068 ti
->error
= "Maximum size of target IO is too large";
1072 ti
->max_io_len
= (uint32_t) len
;
1076 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len
);
1078 static void __map_bio(struct dm_target_io
*tio
)
1082 struct mapped_device
*md
;
1083 struct bio
*clone
= &tio
->clone
;
1084 struct dm_target
*ti
= tio
->ti
;
1086 clone
->bi_end_io
= clone_endio
;
1087 clone
->bi_private
= tio
;
1090 * Map the clone. If r == 0 we don't need to do
1091 * anything, the target has assumed ownership of
1094 atomic_inc(&tio
->io
->io_count
);
1095 sector
= clone
->bi_sector
;
1096 r
= ti
->type
->map(ti
, clone
);
1097 if (r
== DM_MAPIO_REMAPPED
) {
1098 /* the bio has been remapped so dispatch it */
1100 trace_block_bio_remap(bdev_get_queue(clone
->bi_bdev
), clone
,
1101 tio
->io
->bio
->bi_bdev
->bd_dev
, sector
);
1103 generic_make_request(clone
);
1104 } else if (r
< 0 || r
== DM_MAPIO_REQUEUE
) {
1105 /* error the io and bail out, or requeue it if needed */
1107 dec_pending(tio
->io
, r
);
1110 DMWARN("unimplemented target map return value: %d", r
);
1116 struct mapped_device
*md
;
1117 struct dm_table
*map
;
1121 sector_t sector_count
;
1125 static void bio_setup_sector(struct bio
*bio
, sector_t sector
, sector_t len
)
1127 bio
->bi_sector
= sector
;
1128 bio
->bi_size
= to_bytes(len
);
1131 static void bio_setup_bv(struct bio
*bio
, unsigned short idx
, unsigned short bv_count
)
1134 bio
->bi_vcnt
= idx
+ bv_count
;
1135 bio
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
1138 static void clone_bio_integrity(struct bio
*bio
, struct bio
*clone
,
1139 unsigned short idx
, unsigned len
, unsigned offset
,
1142 if (!bio_integrity(bio
))
1145 bio_integrity_clone(clone
, bio
, GFP_NOIO
);
1148 bio_integrity_trim(clone
, bio_sector_offset(bio
, idx
, offset
), len
);
1152 * Creates a little bio that just does part of a bvec.
1154 static void clone_split_bio(struct dm_target_io
*tio
, struct bio
*bio
,
1155 sector_t sector
, unsigned short idx
,
1156 unsigned offset
, unsigned len
)
1158 struct bio
*clone
= &tio
->clone
;
1159 struct bio_vec
*bv
= bio
->bi_io_vec
+ idx
;
1161 *clone
->bi_io_vec
= *bv
;
1163 bio_setup_sector(clone
, sector
, len
);
1165 clone
->bi_bdev
= bio
->bi_bdev
;
1166 clone
->bi_rw
= bio
->bi_rw
;
1168 clone
->bi_io_vec
->bv_offset
= offset
;
1169 clone
->bi_io_vec
->bv_len
= clone
->bi_size
;
1170 clone
->bi_flags
|= 1 << BIO_CLONED
;
1172 clone_bio_integrity(bio
, clone
, idx
, len
, offset
, 1);
1176 * Creates a bio that consists of range of complete bvecs.
1178 static void clone_bio(struct dm_target_io
*tio
, struct bio
*bio
,
1179 sector_t sector
, unsigned short idx
,
1180 unsigned short bv_count
, unsigned len
)
1182 struct bio
*clone
= &tio
->clone
;
1185 __bio_clone(clone
, bio
);
1186 bio_setup_sector(clone
, sector
, len
);
1187 bio_setup_bv(clone
, idx
, bv_count
);
1189 if (idx
!= bio
->bi_idx
|| clone
->bi_size
< bio
->bi_size
)
1191 clone_bio_integrity(bio
, clone
, idx
, len
, 0, trim
);
1194 static struct dm_target_io
*alloc_tio(struct clone_info
*ci
,
1195 struct dm_target
*ti
, int nr_iovecs
,
1196 unsigned target_bio_nr
)
1198 struct dm_target_io
*tio
;
1201 clone
= bio_alloc_bioset(GFP_NOIO
, nr_iovecs
, ci
->md
->bs
);
1202 tio
= container_of(clone
, struct dm_target_io
, clone
);
1206 memset(&tio
->info
, 0, sizeof(tio
->info
));
1207 tio
->target_bio_nr
= target_bio_nr
;
1212 static void __clone_and_map_simple_bio(struct clone_info
*ci
,
1213 struct dm_target
*ti
,
1214 unsigned target_bio_nr
, sector_t len
)
1216 struct dm_target_io
*tio
= alloc_tio(ci
, ti
, ci
->bio
->bi_max_vecs
, target_bio_nr
);
1217 struct bio
*clone
= &tio
->clone
;
1220 * Discard requests require the bio's inline iovecs be initialized.
1221 * ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush
1222 * and discard, so no need for concern about wasted bvec allocations.
1224 __bio_clone(clone
, ci
->bio
);
1226 bio_setup_sector(clone
, ci
->sector
, len
);
1231 static void __send_duplicate_bios(struct clone_info
*ci
, struct dm_target
*ti
,
1232 unsigned num_bios
, sector_t len
)
1234 unsigned target_bio_nr
;
1236 for (target_bio_nr
= 0; target_bio_nr
< num_bios
; target_bio_nr
++)
1237 __clone_and_map_simple_bio(ci
, ti
, target_bio_nr
, len
);
1240 static int __send_empty_flush(struct clone_info
*ci
)
1242 unsigned target_nr
= 0;
1243 struct dm_target
*ti
;
1245 BUG_ON(bio_has_data(ci
->bio
));
1246 while ((ti
= dm_table_get_target(ci
->map
, target_nr
++)))
1247 __send_duplicate_bios(ci
, ti
, ti
->num_flush_bios
, 0);
1252 static void __clone_and_map_data_bio(struct clone_info
*ci
, struct dm_target
*ti
,
1253 sector_t sector
, int nr_iovecs
,
1254 unsigned short idx
, unsigned short bv_count
,
1255 unsigned offset
, unsigned len
,
1256 unsigned split_bvec
)
1258 struct bio
*bio
= ci
->bio
;
1259 struct dm_target_io
*tio
;
1260 unsigned target_bio_nr
;
1261 unsigned num_target_bios
= 1;
1264 * Does the target want to receive duplicate copies of the bio?
1266 if (bio_data_dir(bio
) == WRITE
&& ti
->num_write_bios
)
1267 num_target_bios
= ti
->num_write_bios(ti
, bio
);
1269 for (target_bio_nr
= 0; target_bio_nr
< num_target_bios
; target_bio_nr
++) {
1270 tio
= alloc_tio(ci
, ti
, nr_iovecs
, target_bio_nr
);
1272 clone_split_bio(tio
, bio
, sector
, idx
, offset
, len
);
1274 clone_bio(tio
, bio
, sector
, idx
, bv_count
, len
);
1279 typedef unsigned (*get_num_bios_fn
)(struct dm_target
*ti
);
1281 static unsigned get_num_discard_bios(struct dm_target
*ti
)
1283 return ti
->num_discard_bios
;
1286 static unsigned get_num_write_same_bios(struct dm_target
*ti
)
1288 return ti
->num_write_same_bios
;
1291 typedef bool (*is_split_required_fn
)(struct dm_target
*ti
);
1293 static bool is_split_required_for_discard(struct dm_target
*ti
)
1295 return ti
->split_discard_bios
;
1298 static int __send_changing_extent_only(struct clone_info
*ci
,
1299 get_num_bios_fn get_num_bios
,
1300 is_split_required_fn is_split_required
)
1302 struct dm_target
*ti
;
1307 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1308 if (!dm_target_is_valid(ti
))
1312 * Even though the device advertised support for this type of
1313 * request, that does not mean every target supports it, and
1314 * reconfiguration might also have changed that since the
1315 * check was performed.
1317 num_bios
= get_num_bios
? get_num_bios(ti
) : 0;
1321 if (is_split_required
&& !is_split_required(ti
))
1322 len
= min(ci
->sector_count
, max_io_len_target_boundary(ci
->sector
, ti
));
1324 len
= min(ci
->sector_count
, max_io_len(ci
->sector
, ti
));
1326 __send_duplicate_bios(ci
, ti
, num_bios
, len
);
1329 } while (ci
->sector_count
-= len
);
1334 static int __send_discard(struct clone_info
*ci
)
1336 return __send_changing_extent_only(ci
, get_num_discard_bios
,
1337 is_split_required_for_discard
);
1340 static int __send_write_same(struct clone_info
*ci
)
1342 return __send_changing_extent_only(ci
, get_num_write_same_bios
, NULL
);
1346 * Find maximum number of sectors / bvecs we can process with a single bio.
1348 static sector_t
__len_within_target(struct clone_info
*ci
, sector_t max
, int *idx
)
1350 struct bio
*bio
= ci
->bio
;
1351 sector_t bv_len
, total_len
= 0;
1353 for (*idx
= ci
->idx
; max
&& (*idx
< bio
->bi_vcnt
); (*idx
)++) {
1354 bv_len
= to_sector(bio
->bi_io_vec
[*idx
].bv_len
);
1360 total_len
+= bv_len
;
1366 static int __split_bvec_across_targets(struct clone_info
*ci
,
1367 struct dm_target
*ti
, sector_t max
)
1369 struct bio
*bio
= ci
->bio
;
1370 struct bio_vec
*bv
= bio
->bi_io_vec
+ ci
->idx
;
1371 sector_t remaining
= to_sector(bv
->bv_len
);
1372 unsigned offset
= 0;
1377 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1378 if (!dm_target_is_valid(ti
))
1381 max
= max_io_len(ci
->sector
, ti
);
1384 len
= min(remaining
, max
);
1386 __clone_and_map_data_bio(ci
, ti
, ci
->sector
, 1, ci
->idx
, 0,
1387 bv
->bv_offset
+ offset
, len
, 1);
1390 ci
->sector_count
-= len
;
1391 offset
+= to_bytes(len
);
1392 } while (remaining
-= len
);
1400 * Select the correct strategy for processing a non-flush bio.
1402 static int __split_and_process_non_flush(struct clone_info
*ci
)
1404 struct bio
*bio
= ci
->bio
;
1405 struct dm_target
*ti
;
1409 if (unlikely(bio
->bi_rw
& REQ_DISCARD
))
1410 return __send_discard(ci
);
1411 else if (unlikely(bio
->bi_rw
& REQ_WRITE_SAME
))
1412 return __send_write_same(ci
);
1414 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1415 if (!dm_target_is_valid(ti
))
1418 max
= max_io_len(ci
->sector
, ti
);
1421 * Optimise for the simple case where we can do all of
1422 * the remaining io with a single clone.
1424 if (ci
->sector_count
<= max
) {
1425 __clone_and_map_data_bio(ci
, ti
, ci
->sector
, bio
->bi_max_vecs
,
1426 ci
->idx
, bio
->bi_vcnt
- ci
->idx
, 0,
1427 ci
->sector_count
, 0);
1428 ci
->sector_count
= 0;
1433 * There are some bvecs that don't span targets.
1434 * Do as many of these as possible.
1436 if (to_sector(bio
->bi_io_vec
[ci
->idx
].bv_len
) <= max
) {
1437 len
= __len_within_target(ci
, max
, &idx
);
1439 __clone_and_map_data_bio(ci
, ti
, ci
->sector
, bio
->bi_max_vecs
,
1440 ci
->idx
, idx
- ci
->idx
, 0, len
, 0);
1443 ci
->sector_count
-= len
;
1450 * Handle a bvec that must be split between two or more targets.
1452 return __split_bvec_across_targets(ci
, ti
, max
);
1456 * Entry point to split a bio into clones and submit them to the targets.
1458 static void __split_and_process_bio(struct mapped_device
*md
,
1459 struct dm_table
*map
, struct bio
*bio
)
1461 struct clone_info ci
;
1464 if (unlikely(!map
)) {
1471 ci
.io
= alloc_io(md
);
1473 atomic_set(&ci
.io
->io_count
, 1);
1476 spin_lock_init(&ci
.io
->endio_lock
);
1477 ci
.sector
= bio
->bi_sector
;
1478 ci
.idx
= bio
->bi_idx
;
1480 start_io_acct(ci
.io
);
1482 if (bio
->bi_rw
& REQ_FLUSH
) {
1483 ci
.bio
= &ci
.md
->flush_bio
;
1484 ci
.sector_count
= 0;
1485 error
= __send_empty_flush(&ci
);
1486 /* dec_pending submits any data associated with flush */
1489 ci
.sector_count
= bio_sectors(bio
);
1490 while (ci
.sector_count
&& !error
)
1491 error
= __split_and_process_non_flush(&ci
);
1494 /* drop the extra reference count */
1495 dec_pending(ci
.io
, error
);
1497 /*-----------------------------------------------------------------
1499 *---------------------------------------------------------------*/
1501 static int dm_merge_bvec(struct request_queue
*q
,
1502 struct bvec_merge_data
*bvm
,
1503 struct bio_vec
*biovec
)
1505 struct mapped_device
*md
= q
->queuedata
;
1506 struct dm_table
*map
= dm_get_live_table_fast(md
);
1507 struct dm_target
*ti
;
1508 sector_t max_sectors
;
1514 ti
= dm_table_find_target(map
, bvm
->bi_sector
);
1515 if (!dm_target_is_valid(ti
))
1519 * Find maximum amount of I/O that won't need splitting
1521 max_sectors
= min(max_io_len(bvm
->bi_sector
, ti
),
1522 (sector_t
) BIO_MAX_SECTORS
);
1523 max_size
= (max_sectors
<< SECTOR_SHIFT
) - bvm
->bi_size
;
1528 * merge_bvec_fn() returns number of bytes
1529 * it can accept at this offset
1530 * max is precomputed maximal io size
1532 if (max_size
&& ti
->type
->merge
)
1533 max_size
= ti
->type
->merge(ti
, bvm
, biovec
, max_size
);
1535 * If the target doesn't support merge method and some of the devices
1536 * provided their merge_bvec method (we know this by looking at
1537 * queue_max_hw_sectors), then we can't allow bios with multiple vector
1538 * entries. So always set max_size to 0, and the code below allows
1541 else if (queue_max_hw_sectors(q
) <= PAGE_SIZE
>> 9)
1546 dm_put_live_table_fast(md
);
1548 * Always allow an entire first page
1550 if (max_size
<= biovec
->bv_len
&& !(bvm
->bi_size
>> SECTOR_SHIFT
))
1551 max_size
= biovec
->bv_len
;
1557 * The request function that just remaps the bio built up by
1560 static void _dm_request(struct request_queue
*q
, struct bio
*bio
)
1562 int rw
= bio_data_dir(bio
);
1563 struct mapped_device
*md
= q
->queuedata
;
1566 struct dm_table
*map
;
1568 map
= dm_get_live_table(md
, &srcu_idx
);
1570 cpu
= part_stat_lock();
1571 part_stat_inc(cpu
, &dm_disk(md
)->part0
, ios
[rw
]);
1572 part_stat_add(cpu
, &dm_disk(md
)->part0
, sectors
[rw
], bio_sectors(bio
));
1575 /* if we're suspended, we have to queue this io for later */
1576 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))) {
1577 dm_put_live_table(md
, srcu_idx
);
1579 if (bio_rw(bio
) != READA
)
1586 __split_and_process_bio(md
, map
, bio
);
1587 dm_put_live_table(md
, srcu_idx
);
1591 int dm_request_based(struct mapped_device
*md
)
1593 return blk_queue_stackable(md
->queue
);
1596 static void dm_request(struct request_queue
*q
, struct bio
*bio
)
1598 struct mapped_device
*md
= q
->queuedata
;
1600 if (dm_request_based(md
))
1601 blk_queue_bio(q
, bio
);
1603 _dm_request(q
, bio
);
1606 void dm_dispatch_request(struct request
*rq
)
1610 if (blk_queue_io_stat(rq
->q
))
1611 rq
->cmd_flags
|= REQ_IO_STAT
;
1613 rq
->start_time
= jiffies
;
1614 r
= blk_insert_cloned_request(rq
->q
, rq
);
1616 dm_complete_request(rq
, r
);
1618 EXPORT_SYMBOL_GPL(dm_dispatch_request
);
1620 static int dm_rq_bio_constructor(struct bio
*bio
, struct bio
*bio_orig
,
1623 struct dm_rq_target_io
*tio
= data
;
1624 struct dm_rq_clone_bio_info
*info
=
1625 container_of(bio
, struct dm_rq_clone_bio_info
, clone
);
1627 info
->orig
= bio_orig
;
1629 bio
->bi_end_io
= end_clone_bio
;
1630 bio
->bi_private
= info
;
1635 static int setup_clone(struct request
*clone
, struct request
*rq
,
1636 struct dm_rq_target_io
*tio
)
1640 r
= blk_rq_prep_clone(clone
, rq
, tio
->md
->bs
, GFP_ATOMIC
,
1641 dm_rq_bio_constructor
, tio
);
1645 clone
->cmd
= rq
->cmd
;
1646 clone
->cmd_len
= rq
->cmd_len
;
1647 clone
->sense
= rq
->sense
;
1648 clone
->buffer
= rq
->buffer
;
1649 clone
->end_io
= end_clone_request
;
1650 clone
->end_io_data
= tio
;
1655 static struct request
*clone_rq(struct request
*rq
, struct mapped_device
*md
,
1658 struct request
*clone
;
1659 struct dm_rq_target_io
*tio
;
1661 tio
= alloc_rq_tio(md
, gfp_mask
);
1669 memset(&tio
->info
, 0, sizeof(tio
->info
));
1671 clone
= &tio
->clone
;
1672 if (setup_clone(clone
, rq
, tio
)) {
1682 * Called with the queue lock held.
1684 static int dm_prep_fn(struct request_queue
*q
, struct request
*rq
)
1686 struct mapped_device
*md
= q
->queuedata
;
1687 struct request
*clone
;
1689 if (unlikely(rq
->special
)) {
1690 DMWARN("Already has something in rq->special.");
1691 return BLKPREP_KILL
;
1694 clone
= clone_rq(rq
, md
, GFP_ATOMIC
);
1696 return BLKPREP_DEFER
;
1698 rq
->special
= clone
;
1699 rq
->cmd_flags
|= REQ_DONTPREP
;
1706 * 0 : the request has been processed (not requeued)
1707 * !0 : the request has been requeued
1709 static int map_request(struct dm_target
*ti
, struct request
*clone
,
1710 struct mapped_device
*md
)
1712 int r
, requeued
= 0;
1713 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1716 r
= ti
->type
->map_rq(ti
, clone
, &tio
->info
);
1718 case DM_MAPIO_SUBMITTED
:
1719 /* The target has taken the I/O to submit by itself later */
1721 case DM_MAPIO_REMAPPED
:
1722 /* The target has remapped the I/O so dispatch it */
1723 trace_block_rq_remap(clone
->q
, clone
, disk_devt(dm_disk(md
)),
1724 blk_rq_pos(tio
->orig
));
1725 dm_dispatch_request(clone
);
1727 case DM_MAPIO_REQUEUE
:
1728 /* The target wants to requeue the I/O */
1729 dm_requeue_unmapped_request(clone
);
1734 DMWARN("unimplemented target map return value: %d", r
);
1738 /* The target wants to complete the I/O */
1739 dm_kill_unmapped_request(clone
, r
);
1746 static struct request
*dm_start_request(struct mapped_device
*md
, struct request
*orig
)
1748 struct request
*clone
;
1750 blk_start_request(orig
);
1751 clone
= orig
->special
;
1752 atomic_inc(&md
->pending
[rq_data_dir(clone
)]);
1755 * Hold the md reference here for the in-flight I/O.
1756 * We can't rely on the reference count by device opener,
1757 * because the device may be closed during the request completion
1758 * when all bios are completed.
1759 * See the comment in rq_completed() too.
1767 * q->request_fn for request-based dm.
1768 * Called with the queue lock held.
1770 static void dm_request_fn(struct request_queue
*q
)
1772 struct mapped_device
*md
= q
->queuedata
;
1774 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
1775 struct dm_target
*ti
;
1776 struct request
*rq
, *clone
;
1780 * For suspend, check blk_queue_stopped() and increment
1781 * ->pending within a single queue_lock not to increment the
1782 * number of in-flight I/Os after the queue is stopped in
1785 while (!blk_queue_stopped(q
)) {
1786 rq
= blk_peek_request(q
);
1790 /* always use block 0 to find the target for flushes for now */
1792 if (!(rq
->cmd_flags
& REQ_FLUSH
))
1793 pos
= blk_rq_pos(rq
);
1795 ti
= dm_table_find_target(map
, pos
);
1796 if (!dm_target_is_valid(ti
)) {
1798 * Must perform setup, that dm_done() requires,
1799 * before calling dm_kill_unmapped_request
1801 DMERR_LIMIT("request attempted access beyond the end of device");
1802 clone
= dm_start_request(md
, rq
);
1803 dm_kill_unmapped_request(clone
, -EIO
);
1807 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
1810 clone
= dm_start_request(md
, rq
);
1812 spin_unlock(q
->queue_lock
);
1813 if (map_request(ti
, clone
, md
))
1816 BUG_ON(!irqs_disabled());
1817 spin_lock(q
->queue_lock
);
1823 BUG_ON(!irqs_disabled());
1824 spin_lock(q
->queue_lock
);
1827 blk_delay_queue(q
, HZ
/ 10);
1829 dm_put_live_table(md
, srcu_idx
);
1832 int dm_underlying_device_busy(struct request_queue
*q
)
1834 return blk_lld_busy(q
);
1836 EXPORT_SYMBOL_GPL(dm_underlying_device_busy
);
1838 static int dm_lld_busy(struct request_queue
*q
)
1841 struct mapped_device
*md
= q
->queuedata
;
1842 struct dm_table
*map
= dm_get_live_table_fast(md
);
1844 if (!map
|| test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))
1847 r
= dm_table_any_busy_target(map
);
1849 dm_put_live_table_fast(md
);
1854 static int dm_any_congested(void *congested_data
, int bdi_bits
)
1857 struct mapped_device
*md
= congested_data
;
1858 struct dm_table
*map
;
1860 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
1861 map
= dm_get_live_table_fast(md
);
1864 * Request-based dm cares about only own queue for
1865 * the query about congestion status of request_queue
1867 if (dm_request_based(md
))
1868 r
= md
->queue
->backing_dev_info
.state
&
1871 r
= dm_table_any_congested(map
, bdi_bits
);
1873 dm_put_live_table_fast(md
);
1879 /*-----------------------------------------------------------------
1880 * An IDR is used to keep track of allocated minor numbers.
1881 *---------------------------------------------------------------*/
1882 static void free_minor(int minor
)
1884 spin_lock(&_minor_lock
);
1885 idr_remove(&_minor_idr
, minor
);
1886 spin_unlock(&_minor_lock
);
1890 * See if the device with a specific minor # is free.
1892 static int specific_minor(int minor
)
1896 if (minor
>= (1 << MINORBITS
))
1899 idr_preload(GFP_KERNEL
);
1900 spin_lock(&_minor_lock
);
1902 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, minor
, minor
+ 1, GFP_NOWAIT
);
1904 spin_unlock(&_minor_lock
);
1907 return r
== -ENOSPC
? -EBUSY
: r
;
1911 static int next_free_minor(int *minor
)
1915 idr_preload(GFP_KERNEL
);
1916 spin_lock(&_minor_lock
);
1918 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, 0, 1 << MINORBITS
, GFP_NOWAIT
);
1920 spin_unlock(&_minor_lock
);
1928 static const struct block_device_operations dm_blk_dops
;
1930 static void dm_wq_work(struct work_struct
*work
);
1932 static void dm_init_md_queue(struct mapped_device
*md
)
1935 * Request-based dm devices cannot be stacked on top of bio-based dm
1936 * devices. The type of this dm device has not been decided yet.
1937 * The type is decided at the first table loading time.
1938 * To prevent problematic device stacking, clear the queue flag
1939 * for request stacking support until then.
1941 * This queue is new, so no concurrency on the queue_flags.
1943 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE
, md
->queue
);
1945 md
->queue
->queuedata
= md
;
1946 md
->queue
->backing_dev_info
.congested_fn
= dm_any_congested
;
1947 md
->queue
->backing_dev_info
.congested_data
= md
;
1948 blk_queue_make_request(md
->queue
, dm_request
);
1949 blk_queue_bounce_limit(md
->queue
, BLK_BOUNCE_ANY
);
1950 blk_queue_merge_bvec(md
->queue
, dm_merge_bvec
);
1954 * Allocate and initialise a blank device with a given minor.
1956 static struct mapped_device
*alloc_dev(int minor
)
1959 struct mapped_device
*md
= kzalloc(sizeof(*md
), GFP_KERNEL
);
1963 DMWARN("unable to allocate device, out of memory.");
1967 if (!try_module_get(THIS_MODULE
))
1968 goto bad_module_get
;
1970 /* get a minor number for the dev */
1971 if (minor
== DM_ANY_MINOR
)
1972 r
= next_free_minor(&minor
);
1974 r
= specific_minor(minor
);
1978 r
= init_srcu_struct(&md
->io_barrier
);
1980 goto bad_io_barrier
;
1982 md
->type
= DM_TYPE_NONE
;
1983 mutex_init(&md
->suspend_lock
);
1984 mutex_init(&md
->type_lock
);
1985 spin_lock_init(&md
->deferred_lock
);
1986 atomic_set(&md
->holders
, 1);
1987 atomic_set(&md
->open_count
, 0);
1988 atomic_set(&md
->event_nr
, 0);
1989 atomic_set(&md
->uevent_seq
, 0);
1990 INIT_LIST_HEAD(&md
->uevent_list
);
1991 spin_lock_init(&md
->uevent_lock
);
1993 md
->queue
= blk_alloc_queue(GFP_KERNEL
);
1997 dm_init_md_queue(md
);
1999 md
->disk
= alloc_disk(1);
2003 atomic_set(&md
->pending
[0], 0);
2004 atomic_set(&md
->pending
[1], 0);
2005 init_waitqueue_head(&md
->wait
);
2006 INIT_WORK(&md
->work
, dm_wq_work
);
2007 init_waitqueue_head(&md
->eventq
);
2009 md
->disk
->major
= _major
;
2010 md
->disk
->first_minor
= minor
;
2011 md
->disk
->fops
= &dm_blk_dops
;
2012 md
->disk
->queue
= md
->queue
;
2013 md
->disk
->private_data
= md
;
2014 sprintf(md
->disk
->disk_name
, "dm-%d", minor
);
2016 format_dev_t(md
->name
, MKDEV(_major
, minor
));
2018 md
->wq
= alloc_workqueue("kdmflush", WQ_MEM_RECLAIM
, 0);
2022 md
->bdev
= bdget_disk(md
->disk
, 0);
2026 bio_init(&md
->flush_bio
);
2027 md
->flush_bio
.bi_bdev
= md
->bdev
;
2028 md
->flush_bio
.bi_rw
= WRITE_FLUSH
;
2030 dm_stats_init(&md
->stats
);
2032 /* Populate the mapping, nobody knows we exist yet */
2033 spin_lock(&_minor_lock
);
2034 old_md
= idr_replace(&_minor_idr
, md
, minor
);
2035 spin_unlock(&_minor_lock
);
2037 BUG_ON(old_md
!= MINOR_ALLOCED
);
2042 destroy_workqueue(md
->wq
);
2044 del_gendisk(md
->disk
);
2047 blk_cleanup_queue(md
->queue
);
2049 cleanup_srcu_struct(&md
->io_barrier
);
2053 module_put(THIS_MODULE
);
2059 static void unlock_fs(struct mapped_device
*md
);
2061 static void free_dev(struct mapped_device
*md
)
2063 int minor
= MINOR(disk_devt(md
->disk
));
2067 destroy_workqueue(md
->wq
);
2069 mempool_destroy(md
->io_pool
);
2071 bioset_free(md
->bs
);
2072 blk_integrity_unregister(md
->disk
);
2073 del_gendisk(md
->disk
);
2074 cleanup_srcu_struct(&md
->io_barrier
);
2077 spin_lock(&_minor_lock
);
2078 md
->disk
->private_data
= NULL
;
2079 spin_unlock(&_minor_lock
);
2082 blk_cleanup_queue(md
->queue
);
2083 dm_stats_cleanup(&md
->stats
);
2084 module_put(THIS_MODULE
);
2088 static void __bind_mempools(struct mapped_device
*md
, struct dm_table
*t
)
2090 struct dm_md_mempools
*p
= dm_table_get_md_mempools(t
);
2092 if (md
->io_pool
&& md
->bs
) {
2093 /* The md already has necessary mempools. */
2094 if (dm_table_get_type(t
) == DM_TYPE_BIO_BASED
) {
2096 * Reload bioset because front_pad may have changed
2097 * because a different table was loaded.
2099 bioset_free(md
->bs
);
2102 } else if (dm_table_get_type(t
) == DM_TYPE_REQUEST_BASED
) {
2104 * There's no need to reload with request-based dm
2105 * because the size of front_pad doesn't change.
2106 * Note for future: If you are to reload bioset,
2107 * prep-ed requests in the queue may refer
2108 * to bio from the old bioset, so you must walk
2109 * through the queue to unprep.
2115 BUG_ON(!p
|| md
->io_pool
|| md
->bs
);
2117 md
->io_pool
= p
->io_pool
;
2123 /* mempool bind completed, now no need any mempools in the table */
2124 dm_table_free_md_mempools(t
);
2128 * Bind a table to the device.
2130 static void event_callback(void *context
)
2132 unsigned long flags
;
2134 struct mapped_device
*md
= (struct mapped_device
*) context
;
2136 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2137 list_splice_init(&md
->uevent_list
, &uevents
);
2138 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2140 dm_send_uevents(&uevents
, &disk_to_dev(md
->disk
)->kobj
);
2142 atomic_inc(&md
->event_nr
);
2143 wake_up(&md
->eventq
);
2147 * Protected by md->suspend_lock obtained by dm_swap_table().
2149 static void __set_size(struct mapped_device
*md
, sector_t size
)
2151 set_capacity(md
->disk
, size
);
2153 i_size_write(md
->bdev
->bd_inode
, (loff_t
)size
<< SECTOR_SHIFT
);
2157 * Return 1 if the queue has a compulsory merge_bvec_fn function.
2159 * If this function returns 0, then the device is either a non-dm
2160 * device without a merge_bvec_fn, or it is a dm device that is
2161 * able to split any bios it receives that are too big.
2163 int dm_queue_merge_is_compulsory(struct request_queue
*q
)
2165 struct mapped_device
*dev_md
;
2167 if (!q
->merge_bvec_fn
)
2170 if (q
->make_request_fn
== dm_request
) {
2171 dev_md
= q
->queuedata
;
2172 if (test_bit(DMF_MERGE_IS_OPTIONAL
, &dev_md
->flags
))
2179 static int dm_device_merge_is_compulsory(struct dm_target
*ti
,
2180 struct dm_dev
*dev
, sector_t start
,
2181 sector_t len
, void *data
)
2183 struct block_device
*bdev
= dev
->bdev
;
2184 struct request_queue
*q
= bdev_get_queue(bdev
);
2186 return dm_queue_merge_is_compulsory(q
);
2190 * Return 1 if it is acceptable to ignore merge_bvec_fn based
2191 * on the properties of the underlying devices.
2193 static int dm_table_merge_is_optional(struct dm_table
*table
)
2196 struct dm_target
*ti
;
2198 while (i
< dm_table_get_num_targets(table
)) {
2199 ti
= dm_table_get_target(table
, i
++);
2201 if (ti
->type
->iterate_devices
&&
2202 ti
->type
->iterate_devices(ti
, dm_device_merge_is_compulsory
, NULL
))
2210 * Returns old map, which caller must destroy.
2212 static struct dm_table
*__bind(struct mapped_device
*md
, struct dm_table
*t
,
2213 struct queue_limits
*limits
)
2215 struct dm_table
*old_map
;
2216 struct request_queue
*q
= md
->queue
;
2218 int merge_is_optional
;
2220 size
= dm_table_get_size(t
);
2223 * Wipe any geometry if the size of the table changed.
2225 if (size
!= dm_get_size(md
))
2226 memset(&md
->geometry
, 0, sizeof(md
->geometry
));
2228 __set_size(md
, size
);
2230 dm_table_event_callback(t
, event_callback
, md
);
2233 * The queue hasn't been stopped yet, if the old table type wasn't
2234 * for request-based during suspension. So stop it to prevent
2235 * I/O mapping before resume.
2236 * This must be done before setting the queue restrictions,
2237 * because request-based dm may be run just after the setting.
2239 if (dm_table_request_based(t
) && !blk_queue_stopped(q
))
2242 __bind_mempools(md
, t
);
2244 merge_is_optional
= dm_table_merge_is_optional(t
);
2247 rcu_assign_pointer(md
->map
, t
);
2248 md
->immutable_target_type
= dm_table_get_immutable_target_type(t
);
2250 dm_table_set_restrictions(t
, q
, limits
);
2251 if (merge_is_optional
)
2252 set_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2254 clear_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2261 * Returns unbound table for the caller to free.
2263 static struct dm_table
*__unbind(struct mapped_device
*md
)
2265 struct dm_table
*map
= md
->map
;
2270 dm_table_event_callback(map
, NULL
, NULL
);
2271 rcu_assign_pointer(md
->map
, NULL
);
2278 * Constructor for a new device.
2280 int dm_create(int minor
, struct mapped_device
**result
)
2282 struct mapped_device
*md
;
2284 md
= alloc_dev(minor
);
2295 * Functions to manage md->type.
2296 * All are required to hold md->type_lock.
2298 void dm_lock_md_type(struct mapped_device
*md
)
2300 mutex_lock(&md
->type_lock
);
2303 void dm_unlock_md_type(struct mapped_device
*md
)
2305 mutex_unlock(&md
->type_lock
);
2308 void dm_set_md_type(struct mapped_device
*md
, unsigned type
)
2310 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2314 unsigned dm_get_md_type(struct mapped_device
*md
)
2316 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2320 struct target_type
*dm_get_immutable_target_type(struct mapped_device
*md
)
2322 return md
->immutable_target_type
;
2326 * The queue_limits are only valid as long as you have a reference
2329 struct queue_limits
*dm_get_queue_limits(struct mapped_device
*md
)
2331 BUG_ON(!atomic_read(&md
->holders
));
2332 return &md
->queue
->limits
;
2334 EXPORT_SYMBOL_GPL(dm_get_queue_limits
);
2337 * Fully initialize a request-based queue (->elevator, ->request_fn, etc).
2339 static int dm_init_request_based_queue(struct mapped_device
*md
)
2341 struct request_queue
*q
= NULL
;
2343 if (md
->queue
->elevator
)
2346 /* Fully initialize the queue */
2347 q
= blk_init_allocated_queue(md
->queue
, dm_request_fn
, NULL
);
2352 dm_init_md_queue(md
);
2353 blk_queue_softirq_done(md
->queue
, dm_softirq_done
);
2354 blk_queue_prep_rq(md
->queue
, dm_prep_fn
);
2355 blk_queue_lld_busy(md
->queue
, dm_lld_busy
);
2357 elv_register_queue(md
->queue
);
2363 * Setup the DM device's queue based on md's type
2365 int dm_setup_md_queue(struct mapped_device
*md
)
2367 if ((dm_get_md_type(md
) == DM_TYPE_REQUEST_BASED
) &&
2368 !dm_init_request_based_queue(md
)) {
2369 DMWARN("Cannot initialize queue for request-based mapped device");
2376 static struct mapped_device
*dm_find_md(dev_t dev
)
2378 struct mapped_device
*md
;
2379 unsigned minor
= MINOR(dev
);
2381 if (MAJOR(dev
) != _major
|| minor
>= (1 << MINORBITS
))
2384 spin_lock(&_minor_lock
);
2386 md
= idr_find(&_minor_idr
, minor
);
2387 if (md
&& (md
== MINOR_ALLOCED
||
2388 (MINOR(disk_devt(dm_disk(md
))) != minor
) ||
2389 dm_deleting_md(md
) ||
2390 test_bit(DMF_FREEING
, &md
->flags
))) {
2396 spin_unlock(&_minor_lock
);
2401 struct mapped_device
*dm_get_md(dev_t dev
)
2403 struct mapped_device
*md
= dm_find_md(dev
);
2410 EXPORT_SYMBOL_GPL(dm_get_md
);
2412 void *dm_get_mdptr(struct mapped_device
*md
)
2414 return md
->interface_ptr
;
2417 void dm_set_mdptr(struct mapped_device
*md
, void *ptr
)
2419 md
->interface_ptr
= ptr
;
2422 void dm_get(struct mapped_device
*md
)
2424 atomic_inc(&md
->holders
);
2425 BUG_ON(test_bit(DMF_FREEING
, &md
->flags
));
2428 const char *dm_device_name(struct mapped_device
*md
)
2432 EXPORT_SYMBOL_GPL(dm_device_name
);
2434 static void __dm_destroy(struct mapped_device
*md
, bool wait
)
2436 struct dm_table
*map
;
2441 spin_lock(&_minor_lock
);
2442 map
= dm_get_live_table(md
, &srcu_idx
);
2443 idr_replace(&_minor_idr
, MINOR_ALLOCED
, MINOR(disk_devt(dm_disk(md
))));
2444 set_bit(DMF_FREEING
, &md
->flags
);
2445 spin_unlock(&_minor_lock
);
2447 if (!dm_suspended_md(md
)) {
2448 dm_table_presuspend_targets(map
);
2449 dm_table_postsuspend_targets(map
);
2452 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2453 dm_put_live_table(md
, srcu_idx
);
2456 * Rare, but there may be I/O requests still going to complete,
2457 * for example. Wait for all references to disappear.
2458 * No one should increment the reference count of the mapped_device,
2459 * after the mapped_device state becomes DMF_FREEING.
2462 while (atomic_read(&md
->holders
))
2464 else if (atomic_read(&md
->holders
))
2465 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2466 dm_device_name(md
), atomic_read(&md
->holders
));
2469 dm_table_destroy(__unbind(md
));
2473 void dm_destroy(struct mapped_device
*md
)
2475 __dm_destroy(md
, true);
2478 void dm_destroy_immediate(struct mapped_device
*md
)
2480 __dm_destroy(md
, false);
2483 void dm_put(struct mapped_device
*md
)
2485 atomic_dec(&md
->holders
);
2487 EXPORT_SYMBOL_GPL(dm_put
);
2489 static int dm_wait_for_completion(struct mapped_device
*md
, int interruptible
)
2492 DECLARE_WAITQUEUE(wait
, current
);
2494 add_wait_queue(&md
->wait
, &wait
);
2497 set_current_state(interruptible
);
2499 if (!md_in_flight(md
))
2502 if (interruptible
== TASK_INTERRUPTIBLE
&&
2503 signal_pending(current
)) {
2510 set_current_state(TASK_RUNNING
);
2512 remove_wait_queue(&md
->wait
, &wait
);
2518 * Process the deferred bios
2520 static void dm_wq_work(struct work_struct
*work
)
2522 struct mapped_device
*md
= container_of(work
, struct mapped_device
,
2526 struct dm_table
*map
;
2528 map
= dm_get_live_table(md
, &srcu_idx
);
2530 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
2531 spin_lock_irq(&md
->deferred_lock
);
2532 c
= bio_list_pop(&md
->deferred
);
2533 spin_unlock_irq(&md
->deferred_lock
);
2538 if (dm_request_based(md
))
2539 generic_make_request(c
);
2541 __split_and_process_bio(md
, map
, c
);
2544 dm_put_live_table(md
, srcu_idx
);
2547 static void dm_queue_flush(struct mapped_device
*md
)
2549 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2550 smp_mb__after_clear_bit();
2551 queue_work(md
->wq
, &md
->work
);
2555 * Swap in a new table, returning the old one for the caller to destroy.
2557 struct dm_table
*dm_swap_table(struct mapped_device
*md
, struct dm_table
*table
)
2559 struct dm_table
*live_map
= NULL
, *map
= ERR_PTR(-EINVAL
);
2560 struct queue_limits limits
;
2563 mutex_lock(&md
->suspend_lock
);
2565 /* device must be suspended */
2566 if (!dm_suspended_md(md
))
2570 * If the new table has no data devices, retain the existing limits.
2571 * This helps multipath with queue_if_no_path if all paths disappear,
2572 * then new I/O is queued based on these limits, and then some paths
2575 if (dm_table_has_no_data_devices(table
)) {
2576 live_map
= dm_get_live_table_fast(md
);
2578 limits
= md
->queue
->limits
;
2579 dm_put_live_table_fast(md
);
2583 r
= dm_calculate_queue_limits(table
, &limits
);
2590 map
= __bind(md
, table
, &limits
);
2593 mutex_unlock(&md
->suspend_lock
);
2598 * Functions to lock and unlock any filesystem running on the
2601 static int lock_fs(struct mapped_device
*md
)
2605 WARN_ON(md
->frozen_sb
);
2607 md
->frozen_sb
= freeze_bdev(md
->bdev
);
2608 if (IS_ERR(md
->frozen_sb
)) {
2609 r
= PTR_ERR(md
->frozen_sb
);
2610 md
->frozen_sb
= NULL
;
2614 set_bit(DMF_FROZEN
, &md
->flags
);
2619 static void unlock_fs(struct mapped_device
*md
)
2621 if (!test_bit(DMF_FROZEN
, &md
->flags
))
2624 thaw_bdev(md
->bdev
, md
->frozen_sb
);
2625 md
->frozen_sb
= NULL
;
2626 clear_bit(DMF_FROZEN
, &md
->flags
);
2630 * We need to be able to change a mapping table under a mounted
2631 * filesystem. For example we might want to move some data in
2632 * the background. Before the table can be swapped with
2633 * dm_bind_table, dm_suspend must be called to flush any in
2634 * flight bios and ensure that any further io gets deferred.
2637 * Suspend mechanism in request-based dm.
2639 * 1. Flush all I/Os by lock_fs() if needed.
2640 * 2. Stop dispatching any I/O by stopping the request_queue.
2641 * 3. Wait for all in-flight I/Os to be completed or requeued.
2643 * To abort suspend, start the request_queue.
2645 int dm_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
2647 struct dm_table
*map
= NULL
;
2649 int do_lockfs
= suspend_flags
& DM_SUSPEND_LOCKFS_FLAG
? 1 : 0;
2650 int noflush
= suspend_flags
& DM_SUSPEND_NOFLUSH_FLAG
? 1 : 0;
2652 mutex_lock(&md
->suspend_lock
);
2654 if (dm_suspended_md(md
)) {
2662 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2663 * This flag is cleared before dm_suspend returns.
2666 set_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2668 /* This does not get reverted if there's an error later. */
2669 dm_table_presuspend_targets(map
);
2672 * Flush I/O to the device.
2673 * Any I/O submitted after lock_fs() may not be flushed.
2674 * noflush takes precedence over do_lockfs.
2675 * (lock_fs() flushes I/Os and waits for them to complete.)
2677 if (!noflush
&& do_lockfs
) {
2684 * Here we must make sure that no processes are submitting requests
2685 * to target drivers i.e. no one may be executing
2686 * __split_and_process_bio. This is called from dm_request and
2689 * To get all processes out of __split_and_process_bio in dm_request,
2690 * we take the write lock. To prevent any process from reentering
2691 * __split_and_process_bio from dm_request and quiesce the thread
2692 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2693 * flush_workqueue(md->wq).
2695 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2696 synchronize_srcu(&md
->io_barrier
);
2699 * Stop md->queue before flushing md->wq in case request-based
2700 * dm defers requests to md->wq from md->queue.
2702 if (dm_request_based(md
))
2703 stop_queue(md
->queue
);
2705 flush_workqueue(md
->wq
);
2708 * At this point no more requests are entering target request routines.
2709 * We call dm_wait_for_completion to wait for all existing requests
2712 r
= dm_wait_for_completion(md
, TASK_INTERRUPTIBLE
);
2715 clear_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2716 synchronize_srcu(&md
->io_barrier
);
2718 /* were we interrupted ? */
2722 if (dm_request_based(md
))
2723 start_queue(md
->queue
);
2726 goto out_unlock
; /* pushback list is already flushed, so skip flush */
2730 * If dm_wait_for_completion returned 0, the device is completely
2731 * quiescent now. There is no request-processing activity. All new
2732 * requests are being added to md->deferred list.
2735 set_bit(DMF_SUSPENDED
, &md
->flags
);
2737 dm_table_postsuspend_targets(map
);
2740 mutex_unlock(&md
->suspend_lock
);
2744 int dm_resume(struct mapped_device
*md
)
2747 struct dm_table
*map
= NULL
;
2749 mutex_lock(&md
->suspend_lock
);
2750 if (!dm_suspended_md(md
))
2754 if (!map
|| !dm_table_get_size(map
))
2757 r
= dm_table_resume_targets(map
);
2764 * Flushing deferred I/Os must be done after targets are resumed
2765 * so that mapping of targets can work correctly.
2766 * Request-based dm is queueing the deferred I/Os in its request_queue.
2768 if (dm_request_based(md
))
2769 start_queue(md
->queue
);
2773 clear_bit(DMF_SUSPENDED
, &md
->flags
);
2777 mutex_unlock(&md
->suspend_lock
);
2783 * Internal suspend/resume works like userspace-driven suspend. It waits
2784 * until all bios finish and prevents issuing new bios to the target drivers.
2785 * It may be used only from the kernel.
2787 * Internal suspend holds md->suspend_lock, which prevents interaction with
2788 * userspace-driven suspend.
2791 void dm_internal_suspend(struct mapped_device
*md
)
2793 mutex_lock(&md
->suspend_lock
);
2794 if (dm_suspended_md(md
))
2797 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2798 synchronize_srcu(&md
->io_barrier
);
2799 flush_workqueue(md
->wq
);
2800 dm_wait_for_completion(md
, TASK_UNINTERRUPTIBLE
);
2803 void dm_internal_resume(struct mapped_device
*md
)
2805 if (dm_suspended_md(md
))
2811 mutex_unlock(&md
->suspend_lock
);
2814 /*-----------------------------------------------------------------
2815 * Event notification.
2816 *---------------------------------------------------------------*/
2817 int dm_kobject_uevent(struct mapped_device
*md
, enum kobject_action action
,
2820 char udev_cookie
[DM_COOKIE_LENGTH
];
2821 char *envp
[] = { udev_cookie
, NULL
};
2824 return kobject_uevent(&disk_to_dev(md
->disk
)->kobj
, action
);
2826 snprintf(udev_cookie
, DM_COOKIE_LENGTH
, "%s=%u",
2827 DM_COOKIE_ENV_VAR_NAME
, cookie
);
2828 return kobject_uevent_env(&disk_to_dev(md
->disk
)->kobj
,
2833 uint32_t dm_next_uevent_seq(struct mapped_device
*md
)
2835 return atomic_add_return(1, &md
->uevent_seq
);
2838 uint32_t dm_get_event_nr(struct mapped_device
*md
)
2840 return atomic_read(&md
->event_nr
);
2843 int dm_wait_event(struct mapped_device
*md
, int event_nr
)
2845 return wait_event_interruptible(md
->eventq
,
2846 (event_nr
!= atomic_read(&md
->event_nr
)));
2849 void dm_uevent_add(struct mapped_device
*md
, struct list_head
*elist
)
2851 unsigned long flags
;
2853 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2854 list_add(elist
, &md
->uevent_list
);
2855 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2859 * The gendisk is only valid as long as you have a reference
2862 struct gendisk
*dm_disk(struct mapped_device
*md
)
2867 struct kobject
*dm_kobject(struct mapped_device
*md
)
2873 * struct mapped_device should not be exported outside of dm.c
2874 * so use this check to verify that kobj is part of md structure
2876 struct mapped_device
*dm_get_from_kobject(struct kobject
*kobj
)
2878 struct mapped_device
*md
;
2880 md
= container_of(kobj
, struct mapped_device
, kobj
);
2881 if (&md
->kobj
!= kobj
)
2884 if (test_bit(DMF_FREEING
, &md
->flags
) ||
2892 int dm_suspended_md(struct mapped_device
*md
)
2894 return test_bit(DMF_SUSPENDED
, &md
->flags
);
2897 int dm_suspended(struct dm_target
*ti
)
2899 return dm_suspended_md(dm_table_get_md(ti
->table
));
2901 EXPORT_SYMBOL_GPL(dm_suspended
);
2903 int dm_noflush_suspending(struct dm_target
*ti
)
2905 return __noflush_suspending(dm_table_get_md(ti
->table
));
2907 EXPORT_SYMBOL_GPL(dm_noflush_suspending
);
2909 struct dm_md_mempools
*dm_alloc_md_mempools(unsigned type
, unsigned integrity
, unsigned per_bio_data_size
)
2911 struct dm_md_mempools
*pools
= kzalloc(sizeof(*pools
), GFP_KERNEL
);
2912 struct kmem_cache
*cachep
;
2913 unsigned int pool_size
;
2914 unsigned int front_pad
;
2919 if (type
== DM_TYPE_BIO_BASED
) {
2921 pool_size
= dm_get_reserved_bio_based_ios();
2922 front_pad
= roundup(per_bio_data_size
, __alignof__(struct dm_target_io
)) + offsetof(struct dm_target_io
, clone
);
2923 } else if (type
== DM_TYPE_REQUEST_BASED
) {
2924 cachep
= _rq_tio_cache
;
2925 pool_size
= dm_get_reserved_rq_based_ios();
2926 front_pad
= offsetof(struct dm_rq_clone_bio_info
, clone
);
2927 /* per_bio_data_size is not used. See __bind_mempools(). */
2928 WARN_ON(per_bio_data_size
!= 0);
2932 pools
->io_pool
= mempool_create_slab_pool(pool_size
, cachep
);
2933 if (!pools
->io_pool
)
2936 pools
->bs
= bioset_create(pool_size
, front_pad
);
2940 if (integrity
&& bioset_integrity_create(pools
->bs
, pool_size
))
2946 dm_free_md_mempools(pools
);
2951 void dm_free_md_mempools(struct dm_md_mempools
*pools
)
2957 mempool_destroy(pools
->io_pool
);
2960 bioset_free(pools
->bs
);
2965 static const struct block_device_operations dm_blk_dops
= {
2966 .open
= dm_blk_open
,
2967 .release
= dm_blk_close
,
2968 .ioctl
= dm_blk_ioctl
,
2969 .getgeo
= dm_blk_getgeo
,
2970 .owner
= THIS_MODULE
2973 EXPORT_SYMBOL(dm_get_mapinfo
);
2978 module_init(dm_init
);
2979 module_exit(dm_exit
);
2981 module_param(major
, uint
, 0);
2982 MODULE_PARM_DESC(major
, "The major number of the device mapper");
2984 module_param(reserved_bio_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
2985 MODULE_PARM_DESC(reserved_bio_based_ios
, "Reserved IOs in bio-based mempools");
2987 module_param(reserved_rq_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
2988 MODULE_PARM_DESC(reserved_rq_based_ios
, "Reserved IOs in request-based mempools");
2990 MODULE_DESCRIPTION(DM_NAME
" driver");
2991 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
2992 MODULE_LICENSE("GPL");