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
);
53 static void do_deferred_remove(struct work_struct
*w
);
55 static DECLARE_WORK(deferred_remove_work
, do_deferred_remove
);
57 static struct workqueue_struct
*deferred_remove_workqueue
;
61 * One of these is allocated per bio.
64 struct mapped_device
*md
;
68 unsigned long start_time
;
69 spinlock_t endio_lock
;
70 struct dm_stats_aux stats_aux
;
74 * For request-based dm.
75 * One of these is allocated per request.
77 struct dm_rq_target_io
{
78 struct mapped_device
*md
;
80 struct request
*orig
, clone
;
86 * For request-based dm - the bio clones we allocate are embedded in these
89 * We allocate these with bio_alloc_bioset, using the front_pad parameter when
90 * the bioset is created - this means the bio has to come at the end of the
93 struct dm_rq_clone_bio_info
{
95 struct dm_rq_target_io
*tio
;
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
119 #define DMF_DEFERRED_REMOVE 7
122 * A dummy definition to make RCU happy.
123 * struct dm_table should never be dereferenced in this file.
130 * Work processed by per-device workqueue.
132 struct mapped_device
{
133 struct srcu_struct io_barrier
;
134 struct mutex suspend_lock
;
139 * The current mapping.
140 * Use dm_get_live_table{_fast} or take suspend_lock for
143 struct dm_table
*map
;
147 struct request_queue
*queue
;
149 /* Protect queue and type against concurrent access. */
150 struct mutex type_lock
;
152 struct target_type
*immutable_target_type
;
154 struct gendisk
*disk
;
160 * A list of ios that arrived while we were suspended.
163 wait_queue_head_t wait
;
164 struct work_struct work
;
165 struct bio_list deferred
;
166 spinlock_t deferred_lock
;
169 * Processing queue (flush)
171 struct workqueue_struct
*wq
;
174 * io objects are allocated from here.
184 wait_queue_head_t eventq
;
186 struct list_head uevent_list
;
187 spinlock_t uevent_lock
; /* Protect access to uevent_list */
190 * freeze/thaw support require holding onto a super block
192 struct super_block
*frozen_sb
;
193 struct block_device
*bdev
;
195 /* forced geometry settings */
196 struct hd_geometry geometry
;
198 /* kobject and completion */
199 struct dm_kobject_holder kobj_holder
;
201 /* zero-length flush that will be cloned and submitted to targets */
202 struct bio flush_bio
;
204 struct dm_stats stats
;
208 * For mempools pre-allocation at the table loading time.
210 struct dm_md_mempools
{
215 #define RESERVED_BIO_BASED_IOS 16
216 #define RESERVED_REQUEST_BASED_IOS 256
217 #define RESERVED_MAX_IOS 1024
218 static struct kmem_cache
*_io_cache
;
219 static struct kmem_cache
*_rq_tio_cache
;
222 * Bio-based DM's mempools' reserved IOs set by the user.
224 static unsigned reserved_bio_based_ios
= RESERVED_BIO_BASED_IOS
;
227 * Request-based DM's mempools' reserved IOs set by the user.
229 static unsigned reserved_rq_based_ios
= RESERVED_REQUEST_BASED_IOS
;
231 static unsigned __dm_get_reserved_ios(unsigned *reserved_ios
,
232 unsigned def
, unsigned max
)
234 unsigned ios
= ACCESS_ONCE(*reserved_ios
);
235 unsigned modified_ios
= 0;
243 (void)cmpxchg(reserved_ios
, ios
, modified_ios
);
250 unsigned dm_get_reserved_bio_based_ios(void)
252 return __dm_get_reserved_ios(&reserved_bio_based_ios
,
253 RESERVED_BIO_BASED_IOS
, RESERVED_MAX_IOS
);
255 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios
);
257 unsigned dm_get_reserved_rq_based_ios(void)
259 return __dm_get_reserved_ios(&reserved_rq_based_ios
,
260 RESERVED_REQUEST_BASED_IOS
, RESERVED_MAX_IOS
);
262 EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios
);
264 static int __init
local_init(void)
268 /* allocate a slab for the dm_ios */
269 _io_cache
= KMEM_CACHE(dm_io
, 0);
273 _rq_tio_cache
= KMEM_CACHE(dm_rq_target_io
, 0);
275 goto out_free_io_cache
;
277 r
= dm_uevent_init();
279 goto out_free_rq_tio_cache
;
281 deferred_remove_workqueue
= alloc_workqueue("kdmremove", WQ_UNBOUND
, 1);
282 if (!deferred_remove_workqueue
) {
284 goto out_uevent_exit
;
288 r
= register_blkdev(_major
, _name
);
290 goto out_free_workqueue
;
298 destroy_workqueue(deferred_remove_workqueue
);
301 out_free_rq_tio_cache
:
302 kmem_cache_destroy(_rq_tio_cache
);
304 kmem_cache_destroy(_io_cache
);
309 static void local_exit(void)
311 flush_scheduled_work();
312 destroy_workqueue(deferred_remove_workqueue
);
314 kmem_cache_destroy(_rq_tio_cache
);
315 kmem_cache_destroy(_io_cache
);
316 unregister_blkdev(_major
, _name
);
321 DMINFO("cleaned up");
324 static int (*_inits
[])(void) __initdata
= {
335 static void (*_exits
[])(void) = {
346 static int __init
dm_init(void)
348 const int count
= ARRAY_SIZE(_inits
);
352 for (i
= 0; i
< count
; i
++) {
367 static void __exit
dm_exit(void)
369 int i
= ARRAY_SIZE(_exits
);
375 * Should be empty by this point.
377 idr_destroy(&_minor_idr
);
381 * Block device functions
383 int dm_deleting_md(struct mapped_device
*md
)
385 return test_bit(DMF_DELETING
, &md
->flags
);
388 static int dm_blk_open(struct block_device
*bdev
, fmode_t mode
)
390 struct mapped_device
*md
;
392 spin_lock(&_minor_lock
);
394 md
= bdev
->bd_disk
->private_data
;
398 if (test_bit(DMF_FREEING
, &md
->flags
) ||
399 dm_deleting_md(md
)) {
405 atomic_inc(&md
->open_count
);
408 spin_unlock(&_minor_lock
);
410 return md
? 0 : -ENXIO
;
413 static void dm_blk_close(struct gendisk
*disk
, fmode_t mode
)
415 struct mapped_device
*md
= disk
->private_data
;
417 spin_lock(&_minor_lock
);
419 if (atomic_dec_and_test(&md
->open_count
) &&
420 (test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
)))
421 queue_work(deferred_remove_workqueue
, &deferred_remove_work
);
425 spin_unlock(&_minor_lock
);
428 int dm_open_count(struct mapped_device
*md
)
430 return atomic_read(&md
->open_count
);
434 * Guarantees nothing is using the device before it's deleted.
436 int dm_lock_for_deletion(struct mapped_device
*md
, bool mark_deferred
, bool only_deferred
)
440 spin_lock(&_minor_lock
);
442 if (dm_open_count(md
)) {
445 set_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
446 } else if (only_deferred
&& !test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
))
449 set_bit(DMF_DELETING
, &md
->flags
);
451 spin_unlock(&_minor_lock
);
456 int dm_cancel_deferred_remove(struct mapped_device
*md
)
460 spin_lock(&_minor_lock
);
462 if (test_bit(DMF_DELETING
, &md
->flags
))
465 clear_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
467 spin_unlock(&_minor_lock
);
472 static void do_deferred_remove(struct work_struct
*w
)
474 dm_deferred_remove();
477 sector_t
dm_get_size(struct mapped_device
*md
)
479 return get_capacity(md
->disk
);
482 struct request_queue
*dm_get_md_queue(struct mapped_device
*md
)
487 struct dm_stats
*dm_get_stats(struct mapped_device
*md
)
492 static int dm_blk_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
494 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
496 return dm_get_geometry(md
, geo
);
499 static int dm_blk_ioctl(struct block_device
*bdev
, fmode_t mode
,
500 unsigned int cmd
, unsigned long arg
)
502 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
504 struct dm_table
*map
;
505 struct dm_target
*tgt
;
509 map
= dm_get_live_table(md
, &srcu_idx
);
511 if (!map
|| !dm_table_get_size(map
))
514 /* We only support devices that have a single target */
515 if (dm_table_get_num_targets(map
) != 1)
518 tgt
= dm_table_get_target(map
, 0);
520 if (dm_suspended_md(md
)) {
525 if (tgt
->type
->ioctl
)
526 r
= tgt
->type
->ioctl(tgt
, cmd
, arg
);
529 dm_put_live_table(md
, srcu_idx
);
531 if (r
== -ENOTCONN
) {
539 static struct dm_io
*alloc_io(struct mapped_device
*md
)
541 return mempool_alloc(md
->io_pool
, GFP_NOIO
);
544 static void free_io(struct mapped_device
*md
, struct dm_io
*io
)
546 mempool_free(io
, md
->io_pool
);
549 static void free_tio(struct mapped_device
*md
, struct dm_target_io
*tio
)
551 bio_put(&tio
->clone
);
554 static struct dm_rq_target_io
*alloc_rq_tio(struct mapped_device
*md
,
557 return mempool_alloc(md
->io_pool
, gfp_mask
);
560 static void free_rq_tio(struct dm_rq_target_io
*tio
)
562 mempool_free(tio
, tio
->md
->io_pool
);
565 static int md_in_flight(struct mapped_device
*md
)
567 return atomic_read(&md
->pending
[READ
]) +
568 atomic_read(&md
->pending
[WRITE
]);
571 static void start_io_acct(struct dm_io
*io
)
573 struct mapped_device
*md
= io
->md
;
574 struct bio
*bio
= io
->bio
;
576 int rw
= bio_data_dir(bio
);
578 io
->start_time
= jiffies
;
580 cpu
= part_stat_lock();
581 part_round_stats(cpu
, &dm_disk(md
)->part0
);
583 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
],
584 atomic_inc_return(&md
->pending
[rw
]));
586 if (unlikely(dm_stats_used(&md
->stats
)))
587 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
588 bio_sectors(bio
), false, 0, &io
->stats_aux
);
591 static void end_io_acct(struct dm_io
*io
)
593 struct mapped_device
*md
= io
->md
;
594 struct bio
*bio
= io
->bio
;
595 unsigned long duration
= jiffies
- io
->start_time
;
597 int rw
= bio_data_dir(bio
);
599 cpu
= part_stat_lock();
600 part_round_stats(cpu
, &dm_disk(md
)->part0
);
601 part_stat_add(cpu
, &dm_disk(md
)->part0
, ticks
[rw
], duration
);
604 if (unlikely(dm_stats_used(&md
->stats
)))
605 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
606 bio_sectors(bio
), true, duration
, &io
->stats_aux
);
609 * After this is decremented the bio must not be touched if it is
612 pending
= atomic_dec_return(&md
->pending
[rw
]);
613 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
], pending
);
614 pending
+= atomic_read(&md
->pending
[rw
^0x1]);
616 /* nudge anyone waiting on suspend queue */
622 * Add the bio to the list of deferred io.
624 static void queue_io(struct mapped_device
*md
, struct bio
*bio
)
628 spin_lock_irqsave(&md
->deferred_lock
, flags
);
629 bio_list_add(&md
->deferred
, bio
);
630 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
631 queue_work(md
->wq
, &md
->work
);
635 * Everyone (including functions in this file), should use this
636 * function to access the md->map field, and make sure they call
637 * dm_put_live_table() when finished.
639 struct dm_table
*dm_get_live_table(struct mapped_device
*md
, int *srcu_idx
) __acquires(md
->io_barrier
)
641 *srcu_idx
= srcu_read_lock(&md
->io_barrier
);
643 return srcu_dereference(md
->map
, &md
->io_barrier
);
646 void dm_put_live_table(struct mapped_device
*md
, int srcu_idx
) __releases(md
->io_barrier
)
648 srcu_read_unlock(&md
->io_barrier
, srcu_idx
);
651 void dm_sync_table(struct mapped_device
*md
)
653 synchronize_srcu(&md
->io_barrier
);
654 synchronize_rcu_expedited();
658 * A fast alternative to dm_get_live_table/dm_put_live_table.
659 * The caller must not block between these two functions.
661 static struct dm_table
*dm_get_live_table_fast(struct mapped_device
*md
) __acquires(RCU
)
664 return rcu_dereference(md
->map
);
667 static void dm_put_live_table_fast(struct mapped_device
*md
) __releases(RCU
)
673 * Get the geometry associated with a dm device
675 int dm_get_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
683 * Set the geometry of a device.
685 int dm_set_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
687 sector_t sz
= (sector_t
)geo
->cylinders
* geo
->heads
* geo
->sectors
;
689 if (geo
->start
> sz
) {
690 DMWARN("Start sector is beyond the geometry limits.");
699 /*-----------------------------------------------------------------
701 * A more elegant soln is in the works that uses the queue
702 * merge fn, unfortunately there are a couple of changes to
703 * the block layer that I want to make for this. So in the
704 * interests of getting something for people to use I give
705 * you this clearly demarcated crap.
706 *---------------------------------------------------------------*/
708 static int __noflush_suspending(struct mapped_device
*md
)
710 return test_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
714 * Decrements the number of outstanding ios that a bio has been
715 * cloned into, completing the original io if necc.
717 static void dec_pending(struct dm_io
*io
, int error
)
722 struct mapped_device
*md
= io
->md
;
724 /* Push-back supersedes any I/O errors */
725 if (unlikely(error
)) {
726 spin_lock_irqsave(&io
->endio_lock
, flags
);
727 if (!(io
->error
> 0 && __noflush_suspending(md
)))
729 spin_unlock_irqrestore(&io
->endio_lock
, flags
);
732 if (atomic_dec_and_test(&io
->io_count
)) {
733 if (io
->error
== DM_ENDIO_REQUEUE
) {
735 * Target requested pushing back the I/O.
737 spin_lock_irqsave(&md
->deferred_lock
, flags
);
738 if (__noflush_suspending(md
))
739 bio_list_add_head(&md
->deferred
, io
->bio
);
741 /* noflush suspend was interrupted. */
743 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
746 io_error
= io
->error
;
751 if (io_error
== DM_ENDIO_REQUEUE
)
754 if ((bio
->bi_rw
& REQ_FLUSH
) && bio
->bi_iter
.bi_size
) {
756 * Preflush done for flush with data, reissue
759 bio
->bi_rw
&= ~REQ_FLUSH
;
762 /* done with normal IO or empty flush */
763 trace_block_bio_complete(md
->queue
, bio
, io_error
);
764 bio_endio(bio
, io_error
);
769 static void disable_write_same(struct mapped_device
*md
)
771 struct queue_limits
*limits
= dm_get_queue_limits(md
);
773 /* device doesn't really support WRITE SAME, disable it */
774 limits
->max_write_same_sectors
= 0;
777 static void clone_endio(struct bio
*bio
, int error
)
780 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
781 struct dm_io
*io
= tio
->io
;
782 struct mapped_device
*md
= tio
->io
->md
;
783 dm_endio_fn endio
= tio
->ti
->type
->end_io
;
785 if (!bio_flagged(bio
, BIO_UPTODATE
) && !error
)
789 r
= endio(tio
->ti
, bio
, error
);
790 if (r
< 0 || r
== DM_ENDIO_REQUEUE
)
792 * error and requeue request are handled
796 else if (r
== DM_ENDIO_INCOMPLETE
)
797 /* The target will handle the io */
800 DMWARN("unimplemented target endio return value: %d", r
);
805 if (unlikely(r
== -EREMOTEIO
&& (bio
->bi_rw
& REQ_WRITE_SAME
) &&
806 !bdev_get_queue(bio
->bi_bdev
)->limits
.max_write_same_sectors
))
807 disable_write_same(md
);
810 dec_pending(io
, error
);
814 * Partial completion handling for request-based dm
816 static void end_clone_bio(struct bio
*clone
, int error
)
818 struct dm_rq_clone_bio_info
*info
=
819 container_of(clone
, struct dm_rq_clone_bio_info
, clone
);
820 struct dm_rq_target_io
*tio
= info
->tio
;
821 struct bio
*bio
= info
->orig
;
822 unsigned int nr_bytes
= info
->orig
->bi_iter
.bi_size
;
828 * An error has already been detected on the request.
829 * Once error occurred, just let clone->end_io() handle
835 * Don't notice the error to the upper layer yet.
836 * The error handling decision is made by the target driver,
837 * when the request is completed.
844 * I/O for the bio successfully completed.
845 * Notice the data completion to the upper layer.
849 * bios are processed from the head of the list.
850 * So the completing bio should always be rq->bio.
851 * If it's not, something wrong is happening.
853 if (tio
->orig
->bio
!= bio
)
854 DMERR("bio completion is going in the middle of the request");
857 * Update the original request.
858 * Do not use blk_end_request() here, because it may complete
859 * the original request before the clone, and break the ordering.
861 blk_update_request(tio
->orig
, 0, nr_bytes
);
865 * Don't touch any member of the md after calling this function because
866 * the md may be freed in dm_put() at the end of this function.
867 * Or do dm_get() before calling this function and dm_put() later.
869 static void rq_completed(struct mapped_device
*md
, int rw
, int run_queue
)
871 atomic_dec(&md
->pending
[rw
]);
873 /* nudge anyone waiting on suspend queue */
874 if (!md_in_flight(md
))
878 * Run this off this callpath, as drivers could invoke end_io while
879 * inside their request_fn (and holding the queue lock). Calling
880 * back into ->request_fn() could deadlock attempting to grab the
884 blk_run_queue_async(md
->queue
);
887 * dm_put() must be at the end of this function. See the comment above
892 static void free_rq_clone(struct request
*clone
)
894 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
896 blk_rq_unprep_clone(clone
);
901 * Complete the clone and the original request.
902 * Must be called without queue lock.
904 static void dm_end_request(struct request
*clone
, int error
)
906 int rw
= rq_data_dir(clone
);
907 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
908 struct mapped_device
*md
= tio
->md
;
909 struct request
*rq
= tio
->orig
;
911 if (rq
->cmd_type
== REQ_TYPE_BLOCK_PC
) {
912 rq
->errors
= clone
->errors
;
913 rq
->resid_len
= clone
->resid_len
;
917 * We are using the sense buffer of the original
919 * So setting the length of the sense data is enough.
921 rq
->sense_len
= clone
->sense_len
;
924 free_rq_clone(clone
);
925 blk_end_request_all(rq
, error
);
926 rq_completed(md
, rw
, true);
929 static void dm_unprep_request(struct request
*rq
)
931 struct request
*clone
= rq
->special
;
934 rq
->cmd_flags
&= ~REQ_DONTPREP
;
936 free_rq_clone(clone
);
940 * Requeue the original request of a clone.
942 void dm_requeue_unmapped_request(struct request
*clone
)
944 int rw
= rq_data_dir(clone
);
945 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
946 struct mapped_device
*md
= tio
->md
;
947 struct request
*rq
= tio
->orig
;
948 struct request_queue
*q
= rq
->q
;
951 dm_unprep_request(rq
);
953 spin_lock_irqsave(q
->queue_lock
, flags
);
954 blk_requeue_request(q
, rq
);
955 spin_unlock_irqrestore(q
->queue_lock
, flags
);
957 rq_completed(md
, rw
, 0);
959 EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request
);
961 static void __stop_queue(struct request_queue
*q
)
966 static void stop_queue(struct request_queue
*q
)
970 spin_lock_irqsave(q
->queue_lock
, flags
);
972 spin_unlock_irqrestore(q
->queue_lock
, flags
);
975 static void __start_queue(struct request_queue
*q
)
977 if (blk_queue_stopped(q
))
981 static void start_queue(struct request_queue
*q
)
985 spin_lock_irqsave(q
->queue_lock
, flags
);
987 spin_unlock_irqrestore(q
->queue_lock
, flags
);
990 static void dm_done(struct request
*clone
, int error
, bool mapped
)
993 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
994 dm_request_endio_fn rq_end_io
= NULL
;
997 rq_end_io
= tio
->ti
->type
->rq_end_io
;
999 if (mapped
&& rq_end_io
)
1000 r
= rq_end_io(tio
->ti
, clone
, error
, &tio
->info
);
1003 if (unlikely(r
== -EREMOTEIO
&& (clone
->cmd_flags
& REQ_WRITE_SAME
) &&
1004 !clone
->q
->limits
.max_write_same_sectors
))
1005 disable_write_same(tio
->md
);
1008 /* The target wants to complete the I/O */
1009 dm_end_request(clone
, r
);
1010 else if (r
== DM_ENDIO_INCOMPLETE
)
1011 /* The target will handle the I/O */
1013 else if (r
== DM_ENDIO_REQUEUE
)
1014 /* The target wants to requeue the I/O */
1015 dm_requeue_unmapped_request(clone
);
1017 DMWARN("unimplemented target endio return value: %d", r
);
1023 * Request completion handler for request-based dm
1025 static void dm_softirq_done(struct request
*rq
)
1028 struct request
*clone
= rq
->completion_data
;
1029 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1031 if (rq
->cmd_flags
& REQ_FAILED
)
1034 dm_done(clone
, tio
->error
, mapped
);
1038 * Complete the clone and the original request with the error status
1039 * through softirq context.
1041 static void dm_complete_request(struct request
*clone
, int error
)
1043 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1044 struct request
*rq
= tio
->orig
;
1047 rq
->completion_data
= clone
;
1048 blk_complete_request(rq
);
1052 * Complete the not-mapped clone and the original request with the error status
1053 * through softirq context.
1054 * Target's rq_end_io() function isn't called.
1055 * This may be used when the target's map_rq() function fails.
1057 void dm_kill_unmapped_request(struct request
*clone
, int error
)
1059 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1060 struct request
*rq
= tio
->orig
;
1062 rq
->cmd_flags
|= REQ_FAILED
;
1063 dm_complete_request(clone
, error
);
1065 EXPORT_SYMBOL_GPL(dm_kill_unmapped_request
);
1068 * Called with the queue lock held
1070 static void end_clone_request(struct request
*clone
, int error
)
1073 * For just cleaning up the information of the queue in which
1074 * the clone was dispatched.
1075 * The clone is *NOT* freed actually here because it is alloced from
1076 * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags.
1078 __blk_put_request(clone
->q
, clone
);
1081 * Actual request completion is done in a softirq context which doesn't
1082 * hold the queue lock. Otherwise, deadlock could occur because:
1083 * - another request may be submitted by the upper level driver
1084 * of the stacking during the completion
1085 * - the submission which requires queue lock may be done
1086 * against this queue
1088 dm_complete_request(clone
, error
);
1092 * Return maximum size of I/O possible at the supplied sector up to the current
1095 static sector_t
max_io_len_target_boundary(sector_t sector
, struct dm_target
*ti
)
1097 sector_t target_offset
= dm_target_offset(ti
, sector
);
1099 return ti
->len
- target_offset
;
1102 static sector_t
max_io_len(sector_t sector
, struct dm_target
*ti
)
1104 sector_t len
= max_io_len_target_boundary(sector
, ti
);
1105 sector_t offset
, max_len
;
1108 * Does the target need to split even further?
1110 if (ti
->max_io_len
) {
1111 offset
= dm_target_offset(ti
, sector
);
1112 if (unlikely(ti
->max_io_len
& (ti
->max_io_len
- 1)))
1113 max_len
= sector_div(offset
, ti
->max_io_len
);
1115 max_len
= offset
& (ti
->max_io_len
- 1);
1116 max_len
= ti
->max_io_len
- max_len
;
1125 int dm_set_target_max_io_len(struct dm_target
*ti
, sector_t len
)
1127 if (len
> UINT_MAX
) {
1128 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1129 (unsigned long long)len
, UINT_MAX
);
1130 ti
->error
= "Maximum size of target IO is too large";
1134 ti
->max_io_len
= (uint32_t) len
;
1138 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len
);
1141 * A target may call dm_accept_partial_bio only from the map routine. It is
1142 * allowed for all bio types except REQ_FLUSH.
1144 * dm_accept_partial_bio informs the dm that the target only wants to process
1145 * additional n_sectors sectors of the bio and the rest of the data should be
1146 * sent in a next bio.
1148 * A diagram that explains the arithmetics:
1149 * +--------------------+---------------+-------+
1151 * +--------------------+---------------+-------+
1153 * <-------------- *tio->len_ptr --------------->
1154 * <------- bi_size ------->
1157 * Region 1 was already iterated over with bio_advance or similar function.
1158 * (it may be empty if the target doesn't use bio_advance)
1159 * Region 2 is the remaining bio size that the target wants to process.
1160 * (it may be empty if region 1 is non-empty, although there is no reason
1162 * The target requires that region 3 is to be sent in the next bio.
1164 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1165 * the partially processed part (the sum of regions 1+2) must be the same for all
1166 * copies of the bio.
1168 void dm_accept_partial_bio(struct bio
*bio
, unsigned n_sectors
)
1170 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
1171 unsigned bi_size
= bio
->bi_iter
.bi_size
>> SECTOR_SHIFT
;
1172 BUG_ON(bio
->bi_rw
& REQ_FLUSH
);
1173 BUG_ON(bi_size
> *tio
->len_ptr
);
1174 BUG_ON(n_sectors
> bi_size
);
1175 *tio
->len_ptr
-= bi_size
- n_sectors
;
1176 bio
->bi_iter
.bi_size
= n_sectors
<< SECTOR_SHIFT
;
1178 EXPORT_SYMBOL_GPL(dm_accept_partial_bio
);
1180 static void __map_bio(struct dm_target_io
*tio
)
1184 struct mapped_device
*md
;
1185 struct bio
*clone
= &tio
->clone
;
1186 struct dm_target
*ti
= tio
->ti
;
1188 clone
->bi_end_io
= clone_endio
;
1191 * Map the clone. If r == 0 we don't need to do
1192 * anything, the target has assumed ownership of
1195 atomic_inc(&tio
->io
->io_count
);
1196 sector
= clone
->bi_iter
.bi_sector
;
1197 r
= ti
->type
->map(ti
, clone
);
1198 if (r
== DM_MAPIO_REMAPPED
) {
1199 /* the bio has been remapped so dispatch it */
1201 trace_block_bio_remap(bdev_get_queue(clone
->bi_bdev
), clone
,
1202 tio
->io
->bio
->bi_bdev
->bd_dev
, sector
);
1204 generic_make_request(clone
);
1205 } else if (r
< 0 || r
== DM_MAPIO_REQUEUE
) {
1206 /* error the io and bail out, or requeue it if needed */
1208 dec_pending(tio
->io
, r
);
1211 DMWARN("unimplemented target map return value: %d", r
);
1217 struct mapped_device
*md
;
1218 struct dm_table
*map
;
1222 unsigned sector_count
;
1225 static void bio_setup_sector(struct bio
*bio
, sector_t sector
, unsigned len
)
1227 bio
->bi_iter
.bi_sector
= sector
;
1228 bio
->bi_iter
.bi_size
= to_bytes(len
);
1232 * Creates a bio that consists of range of complete bvecs.
1234 static void clone_bio(struct dm_target_io
*tio
, struct bio
*bio
,
1235 sector_t sector
, unsigned len
)
1237 struct bio
*clone
= &tio
->clone
;
1239 __bio_clone_fast(clone
, bio
);
1241 if (bio_integrity(bio
))
1242 bio_integrity_clone(clone
, bio
, GFP_NOIO
);
1244 bio_advance(clone
, to_bytes(sector
- clone
->bi_iter
.bi_sector
));
1245 clone
->bi_iter
.bi_size
= to_bytes(len
);
1247 if (bio_integrity(bio
))
1248 bio_integrity_trim(clone
, 0, len
);
1251 static struct dm_target_io
*alloc_tio(struct clone_info
*ci
,
1252 struct dm_target
*ti
, int nr_iovecs
,
1253 unsigned target_bio_nr
)
1255 struct dm_target_io
*tio
;
1258 clone
= bio_alloc_bioset(GFP_NOIO
, nr_iovecs
, ci
->md
->bs
);
1259 tio
= container_of(clone
, struct dm_target_io
, clone
);
1263 tio
->target_bio_nr
= target_bio_nr
;
1268 static void __clone_and_map_simple_bio(struct clone_info
*ci
,
1269 struct dm_target
*ti
,
1270 unsigned target_bio_nr
, unsigned *len
)
1272 struct dm_target_io
*tio
= alloc_tio(ci
, ti
, ci
->bio
->bi_max_vecs
, target_bio_nr
);
1273 struct bio
*clone
= &tio
->clone
;
1278 * Discard requests require the bio's inline iovecs be initialized.
1279 * ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush
1280 * and discard, so no need for concern about wasted bvec allocations.
1282 __bio_clone_fast(clone
, ci
->bio
);
1284 bio_setup_sector(clone
, ci
->sector
, *len
);
1289 static void __send_duplicate_bios(struct clone_info
*ci
, struct dm_target
*ti
,
1290 unsigned num_bios
, unsigned *len
)
1292 unsigned target_bio_nr
;
1294 for (target_bio_nr
= 0; target_bio_nr
< num_bios
; target_bio_nr
++)
1295 __clone_and_map_simple_bio(ci
, ti
, target_bio_nr
, len
);
1298 static int __send_empty_flush(struct clone_info
*ci
)
1300 unsigned target_nr
= 0;
1301 struct dm_target
*ti
;
1303 BUG_ON(bio_has_data(ci
->bio
));
1304 while ((ti
= dm_table_get_target(ci
->map
, target_nr
++)))
1305 __send_duplicate_bios(ci
, ti
, ti
->num_flush_bios
, NULL
);
1310 static void __clone_and_map_data_bio(struct clone_info
*ci
, struct dm_target
*ti
,
1311 sector_t sector
, unsigned *len
)
1313 struct bio
*bio
= ci
->bio
;
1314 struct dm_target_io
*tio
;
1315 unsigned target_bio_nr
;
1316 unsigned num_target_bios
= 1;
1319 * Does the target want to receive duplicate copies of the bio?
1321 if (bio_data_dir(bio
) == WRITE
&& ti
->num_write_bios
)
1322 num_target_bios
= ti
->num_write_bios(ti
, bio
);
1324 for (target_bio_nr
= 0; target_bio_nr
< num_target_bios
; target_bio_nr
++) {
1325 tio
= alloc_tio(ci
, ti
, 0, target_bio_nr
);
1327 clone_bio(tio
, bio
, sector
, *len
);
1332 typedef unsigned (*get_num_bios_fn
)(struct dm_target
*ti
);
1334 static unsigned get_num_discard_bios(struct dm_target
*ti
)
1336 return ti
->num_discard_bios
;
1339 static unsigned get_num_write_same_bios(struct dm_target
*ti
)
1341 return ti
->num_write_same_bios
;
1344 typedef bool (*is_split_required_fn
)(struct dm_target
*ti
);
1346 static bool is_split_required_for_discard(struct dm_target
*ti
)
1348 return ti
->split_discard_bios
;
1351 static int __send_changing_extent_only(struct clone_info
*ci
,
1352 get_num_bios_fn get_num_bios
,
1353 is_split_required_fn is_split_required
)
1355 struct dm_target
*ti
;
1360 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1361 if (!dm_target_is_valid(ti
))
1365 * Even though the device advertised support for this type of
1366 * request, that does not mean every target supports it, and
1367 * reconfiguration might also have changed that since the
1368 * check was performed.
1370 num_bios
= get_num_bios
? get_num_bios(ti
) : 0;
1374 if (is_split_required
&& !is_split_required(ti
))
1375 len
= min((sector_t
)ci
->sector_count
, max_io_len_target_boundary(ci
->sector
, ti
));
1377 len
= min((sector_t
)ci
->sector_count
, max_io_len(ci
->sector
, ti
));
1379 __send_duplicate_bios(ci
, ti
, num_bios
, &len
);
1382 } while (ci
->sector_count
-= len
);
1387 static int __send_discard(struct clone_info
*ci
)
1389 return __send_changing_extent_only(ci
, get_num_discard_bios
,
1390 is_split_required_for_discard
);
1393 static int __send_write_same(struct clone_info
*ci
)
1395 return __send_changing_extent_only(ci
, get_num_write_same_bios
, NULL
);
1399 * Select the correct strategy for processing a non-flush bio.
1401 static int __split_and_process_non_flush(struct clone_info
*ci
)
1403 struct bio
*bio
= ci
->bio
;
1404 struct dm_target
*ti
;
1407 if (unlikely(bio
->bi_rw
& REQ_DISCARD
))
1408 return __send_discard(ci
);
1409 else if (unlikely(bio
->bi_rw
& REQ_WRITE_SAME
))
1410 return __send_write_same(ci
);
1412 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1413 if (!dm_target_is_valid(ti
))
1416 len
= min_t(sector_t
, max_io_len(ci
->sector
, ti
), ci
->sector_count
);
1418 __clone_and_map_data_bio(ci
, ti
, ci
->sector
, &len
);
1421 ci
->sector_count
-= len
;
1427 * Entry point to split a bio into clones and submit them to the targets.
1429 static void __split_and_process_bio(struct mapped_device
*md
,
1430 struct dm_table
*map
, struct bio
*bio
)
1432 struct clone_info ci
;
1435 if (unlikely(!map
)) {
1442 ci
.io
= alloc_io(md
);
1444 atomic_set(&ci
.io
->io_count
, 1);
1447 spin_lock_init(&ci
.io
->endio_lock
);
1448 ci
.sector
= bio
->bi_iter
.bi_sector
;
1450 start_io_acct(ci
.io
);
1452 if (bio
->bi_rw
& REQ_FLUSH
) {
1453 ci
.bio
= &ci
.md
->flush_bio
;
1454 ci
.sector_count
= 0;
1455 error
= __send_empty_flush(&ci
);
1456 /* dec_pending submits any data associated with flush */
1459 ci
.sector_count
= bio_sectors(bio
);
1460 while (ci
.sector_count
&& !error
)
1461 error
= __split_and_process_non_flush(&ci
);
1464 /* drop the extra reference count */
1465 dec_pending(ci
.io
, error
);
1467 /*-----------------------------------------------------------------
1469 *---------------------------------------------------------------*/
1471 static int dm_merge_bvec(struct request_queue
*q
,
1472 struct bvec_merge_data
*bvm
,
1473 struct bio_vec
*biovec
)
1475 struct mapped_device
*md
= q
->queuedata
;
1476 struct dm_table
*map
= dm_get_live_table_fast(md
);
1477 struct dm_target
*ti
;
1478 sector_t max_sectors
;
1484 ti
= dm_table_find_target(map
, bvm
->bi_sector
);
1485 if (!dm_target_is_valid(ti
))
1489 * Find maximum amount of I/O that won't need splitting
1491 max_sectors
= min(max_io_len(bvm
->bi_sector
, ti
),
1492 (sector_t
) BIO_MAX_SECTORS
);
1493 max_size
= (max_sectors
<< SECTOR_SHIFT
) - bvm
->bi_size
;
1498 * merge_bvec_fn() returns number of bytes
1499 * it can accept at this offset
1500 * max is precomputed maximal io size
1502 if (max_size
&& ti
->type
->merge
)
1503 max_size
= ti
->type
->merge(ti
, bvm
, biovec
, max_size
);
1505 * If the target doesn't support merge method and some of the devices
1506 * provided their merge_bvec method (we know this by looking at
1507 * queue_max_hw_sectors), then we can't allow bios with multiple vector
1508 * entries. So always set max_size to 0, and the code below allows
1511 else if (queue_max_hw_sectors(q
) <= PAGE_SIZE
>> 9)
1515 dm_put_live_table_fast(md
);
1517 * Always allow an entire first page
1519 if (max_size
<= biovec
->bv_len
&& !(bvm
->bi_size
>> SECTOR_SHIFT
))
1520 max_size
= biovec
->bv_len
;
1526 * The request function that just remaps the bio built up by
1529 static void _dm_request(struct request_queue
*q
, struct bio
*bio
)
1531 int rw
= bio_data_dir(bio
);
1532 struct mapped_device
*md
= q
->queuedata
;
1535 struct dm_table
*map
;
1537 map
= dm_get_live_table(md
, &srcu_idx
);
1539 cpu
= part_stat_lock();
1540 part_stat_inc(cpu
, &dm_disk(md
)->part0
, ios
[rw
]);
1541 part_stat_add(cpu
, &dm_disk(md
)->part0
, sectors
[rw
], bio_sectors(bio
));
1544 /* if we're suspended, we have to queue this io for later */
1545 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))) {
1546 dm_put_live_table(md
, srcu_idx
);
1548 if (bio_rw(bio
) != READA
)
1555 __split_and_process_bio(md
, map
, bio
);
1556 dm_put_live_table(md
, srcu_idx
);
1560 int dm_request_based(struct mapped_device
*md
)
1562 return blk_queue_stackable(md
->queue
);
1565 static void dm_request(struct request_queue
*q
, struct bio
*bio
)
1567 struct mapped_device
*md
= q
->queuedata
;
1569 if (dm_request_based(md
))
1570 blk_queue_bio(q
, bio
);
1572 _dm_request(q
, bio
);
1575 void dm_dispatch_request(struct request
*rq
)
1579 if (blk_queue_io_stat(rq
->q
))
1580 rq
->cmd_flags
|= REQ_IO_STAT
;
1582 rq
->start_time
= jiffies
;
1583 r
= blk_insert_cloned_request(rq
->q
, rq
);
1585 dm_complete_request(rq
, r
);
1587 EXPORT_SYMBOL_GPL(dm_dispatch_request
);
1589 static int dm_rq_bio_constructor(struct bio
*bio
, struct bio
*bio_orig
,
1592 struct dm_rq_target_io
*tio
= data
;
1593 struct dm_rq_clone_bio_info
*info
=
1594 container_of(bio
, struct dm_rq_clone_bio_info
, clone
);
1596 info
->orig
= bio_orig
;
1598 bio
->bi_end_io
= end_clone_bio
;
1603 static int setup_clone(struct request
*clone
, struct request
*rq
,
1604 struct dm_rq_target_io
*tio
)
1608 r
= blk_rq_prep_clone(clone
, rq
, tio
->md
->bs
, GFP_ATOMIC
,
1609 dm_rq_bio_constructor
, tio
);
1613 clone
->cmd
= rq
->cmd
;
1614 clone
->cmd_len
= rq
->cmd_len
;
1615 clone
->sense
= rq
->sense
;
1616 clone
->end_io
= end_clone_request
;
1617 clone
->end_io_data
= tio
;
1622 static struct request
*clone_rq(struct request
*rq
, struct mapped_device
*md
,
1625 struct request
*clone
;
1626 struct dm_rq_target_io
*tio
;
1628 tio
= alloc_rq_tio(md
, gfp_mask
);
1636 memset(&tio
->info
, 0, sizeof(tio
->info
));
1638 clone
= &tio
->clone
;
1639 if (setup_clone(clone
, rq
, tio
)) {
1649 * Called with the queue lock held.
1651 static int dm_prep_fn(struct request_queue
*q
, struct request
*rq
)
1653 struct mapped_device
*md
= q
->queuedata
;
1654 struct request
*clone
;
1656 if (unlikely(rq
->special
)) {
1657 DMWARN("Already has something in rq->special.");
1658 return BLKPREP_KILL
;
1661 clone
= clone_rq(rq
, md
, GFP_ATOMIC
);
1663 return BLKPREP_DEFER
;
1665 rq
->special
= clone
;
1666 rq
->cmd_flags
|= REQ_DONTPREP
;
1673 * 0 : the request has been processed (not requeued)
1674 * !0 : the request has been requeued
1676 static int map_request(struct dm_target
*ti
, struct request
*clone
,
1677 struct mapped_device
*md
)
1679 int r
, requeued
= 0;
1680 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1683 r
= ti
->type
->map_rq(ti
, clone
, &tio
->info
);
1685 case DM_MAPIO_SUBMITTED
:
1686 /* The target has taken the I/O to submit by itself later */
1688 case DM_MAPIO_REMAPPED
:
1689 /* The target has remapped the I/O so dispatch it */
1690 trace_block_rq_remap(clone
->q
, clone
, disk_devt(dm_disk(md
)),
1691 blk_rq_pos(tio
->orig
));
1692 dm_dispatch_request(clone
);
1694 case DM_MAPIO_REQUEUE
:
1695 /* The target wants to requeue the I/O */
1696 dm_requeue_unmapped_request(clone
);
1701 DMWARN("unimplemented target map return value: %d", r
);
1705 /* The target wants to complete the I/O */
1706 dm_kill_unmapped_request(clone
, r
);
1713 static struct request
*dm_start_request(struct mapped_device
*md
, struct request
*orig
)
1715 struct request
*clone
;
1717 blk_start_request(orig
);
1718 clone
= orig
->special
;
1719 atomic_inc(&md
->pending
[rq_data_dir(clone
)]);
1722 * Hold the md reference here for the in-flight I/O.
1723 * We can't rely on the reference count by device opener,
1724 * because the device may be closed during the request completion
1725 * when all bios are completed.
1726 * See the comment in rq_completed() too.
1734 * q->request_fn for request-based dm.
1735 * Called with the queue lock held.
1737 static void dm_request_fn(struct request_queue
*q
)
1739 struct mapped_device
*md
= q
->queuedata
;
1741 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
1742 struct dm_target
*ti
;
1743 struct request
*rq
, *clone
;
1747 * For suspend, check blk_queue_stopped() and increment
1748 * ->pending within a single queue_lock not to increment the
1749 * number of in-flight I/Os after the queue is stopped in
1752 while (!blk_queue_stopped(q
)) {
1753 rq
= blk_peek_request(q
);
1757 /* always use block 0 to find the target for flushes for now */
1759 if (!(rq
->cmd_flags
& REQ_FLUSH
))
1760 pos
= blk_rq_pos(rq
);
1762 ti
= dm_table_find_target(map
, pos
);
1763 if (!dm_target_is_valid(ti
)) {
1765 * Must perform setup, that dm_done() requires,
1766 * before calling dm_kill_unmapped_request
1768 DMERR_LIMIT("request attempted access beyond the end of device");
1769 clone
= dm_start_request(md
, rq
);
1770 dm_kill_unmapped_request(clone
, -EIO
);
1774 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
1777 clone
= dm_start_request(md
, rq
);
1779 spin_unlock(q
->queue_lock
);
1780 if (map_request(ti
, clone
, md
))
1783 BUG_ON(!irqs_disabled());
1784 spin_lock(q
->queue_lock
);
1790 BUG_ON(!irqs_disabled());
1791 spin_lock(q
->queue_lock
);
1794 blk_delay_queue(q
, HZ
/ 10);
1796 dm_put_live_table(md
, srcu_idx
);
1799 int dm_underlying_device_busy(struct request_queue
*q
)
1801 return blk_lld_busy(q
);
1803 EXPORT_SYMBOL_GPL(dm_underlying_device_busy
);
1805 static int dm_lld_busy(struct request_queue
*q
)
1808 struct mapped_device
*md
= q
->queuedata
;
1809 struct dm_table
*map
= dm_get_live_table_fast(md
);
1811 if (!map
|| test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))
1814 r
= dm_table_any_busy_target(map
);
1816 dm_put_live_table_fast(md
);
1821 static int dm_any_congested(void *congested_data
, int bdi_bits
)
1824 struct mapped_device
*md
= congested_data
;
1825 struct dm_table
*map
;
1827 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
1828 map
= dm_get_live_table_fast(md
);
1831 * Request-based dm cares about only own queue for
1832 * the query about congestion status of request_queue
1834 if (dm_request_based(md
))
1835 r
= md
->queue
->backing_dev_info
.state
&
1838 r
= dm_table_any_congested(map
, bdi_bits
);
1840 dm_put_live_table_fast(md
);
1846 /*-----------------------------------------------------------------
1847 * An IDR is used to keep track of allocated minor numbers.
1848 *---------------------------------------------------------------*/
1849 static void free_minor(int minor
)
1851 spin_lock(&_minor_lock
);
1852 idr_remove(&_minor_idr
, minor
);
1853 spin_unlock(&_minor_lock
);
1857 * See if the device with a specific minor # is free.
1859 static int specific_minor(int minor
)
1863 if (minor
>= (1 << MINORBITS
))
1866 idr_preload(GFP_KERNEL
);
1867 spin_lock(&_minor_lock
);
1869 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, minor
, minor
+ 1, GFP_NOWAIT
);
1871 spin_unlock(&_minor_lock
);
1874 return r
== -ENOSPC
? -EBUSY
: r
;
1878 static int next_free_minor(int *minor
)
1882 idr_preload(GFP_KERNEL
);
1883 spin_lock(&_minor_lock
);
1885 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, 0, 1 << MINORBITS
, GFP_NOWAIT
);
1887 spin_unlock(&_minor_lock
);
1895 static const struct block_device_operations dm_blk_dops
;
1897 static void dm_wq_work(struct work_struct
*work
);
1899 static void dm_init_md_queue(struct mapped_device
*md
)
1902 * Request-based dm devices cannot be stacked on top of bio-based dm
1903 * devices. The type of this dm device has not been decided yet.
1904 * The type is decided at the first table loading time.
1905 * To prevent problematic device stacking, clear the queue flag
1906 * for request stacking support until then.
1908 * This queue is new, so no concurrency on the queue_flags.
1910 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE
, md
->queue
);
1912 md
->queue
->queuedata
= md
;
1913 md
->queue
->backing_dev_info
.congested_fn
= dm_any_congested
;
1914 md
->queue
->backing_dev_info
.congested_data
= md
;
1915 blk_queue_make_request(md
->queue
, dm_request
);
1916 blk_queue_bounce_limit(md
->queue
, BLK_BOUNCE_ANY
);
1917 blk_queue_merge_bvec(md
->queue
, dm_merge_bvec
);
1921 * Allocate and initialise a blank device with a given minor.
1923 static struct mapped_device
*alloc_dev(int minor
)
1926 struct mapped_device
*md
= kzalloc(sizeof(*md
), GFP_KERNEL
);
1930 DMWARN("unable to allocate device, out of memory.");
1934 if (!try_module_get(THIS_MODULE
))
1935 goto bad_module_get
;
1937 /* get a minor number for the dev */
1938 if (minor
== DM_ANY_MINOR
)
1939 r
= next_free_minor(&minor
);
1941 r
= specific_minor(minor
);
1945 r
= init_srcu_struct(&md
->io_barrier
);
1947 goto bad_io_barrier
;
1949 md
->type
= DM_TYPE_NONE
;
1950 mutex_init(&md
->suspend_lock
);
1951 mutex_init(&md
->type_lock
);
1952 spin_lock_init(&md
->deferred_lock
);
1953 atomic_set(&md
->holders
, 1);
1954 atomic_set(&md
->open_count
, 0);
1955 atomic_set(&md
->event_nr
, 0);
1956 atomic_set(&md
->uevent_seq
, 0);
1957 INIT_LIST_HEAD(&md
->uevent_list
);
1958 spin_lock_init(&md
->uevent_lock
);
1960 md
->queue
= blk_alloc_queue(GFP_KERNEL
);
1964 dm_init_md_queue(md
);
1966 md
->disk
= alloc_disk(1);
1970 atomic_set(&md
->pending
[0], 0);
1971 atomic_set(&md
->pending
[1], 0);
1972 init_waitqueue_head(&md
->wait
);
1973 INIT_WORK(&md
->work
, dm_wq_work
);
1974 init_waitqueue_head(&md
->eventq
);
1975 init_completion(&md
->kobj_holder
.completion
);
1977 md
->disk
->major
= _major
;
1978 md
->disk
->first_minor
= minor
;
1979 md
->disk
->fops
= &dm_blk_dops
;
1980 md
->disk
->queue
= md
->queue
;
1981 md
->disk
->private_data
= md
;
1982 sprintf(md
->disk
->disk_name
, "dm-%d", minor
);
1984 format_dev_t(md
->name
, MKDEV(_major
, minor
));
1986 md
->wq
= alloc_workqueue("kdmflush", WQ_MEM_RECLAIM
, 0);
1990 md
->bdev
= bdget_disk(md
->disk
, 0);
1994 bio_init(&md
->flush_bio
);
1995 md
->flush_bio
.bi_bdev
= md
->bdev
;
1996 md
->flush_bio
.bi_rw
= WRITE_FLUSH
;
1998 dm_stats_init(&md
->stats
);
2000 /* Populate the mapping, nobody knows we exist yet */
2001 spin_lock(&_minor_lock
);
2002 old_md
= idr_replace(&_minor_idr
, md
, minor
);
2003 spin_unlock(&_minor_lock
);
2005 BUG_ON(old_md
!= MINOR_ALLOCED
);
2010 destroy_workqueue(md
->wq
);
2012 del_gendisk(md
->disk
);
2015 blk_cleanup_queue(md
->queue
);
2017 cleanup_srcu_struct(&md
->io_barrier
);
2021 module_put(THIS_MODULE
);
2027 static void unlock_fs(struct mapped_device
*md
);
2029 static void free_dev(struct mapped_device
*md
)
2031 int minor
= MINOR(disk_devt(md
->disk
));
2035 destroy_workqueue(md
->wq
);
2037 mempool_destroy(md
->io_pool
);
2039 bioset_free(md
->bs
);
2040 blk_integrity_unregister(md
->disk
);
2041 del_gendisk(md
->disk
);
2042 cleanup_srcu_struct(&md
->io_barrier
);
2045 spin_lock(&_minor_lock
);
2046 md
->disk
->private_data
= NULL
;
2047 spin_unlock(&_minor_lock
);
2050 blk_cleanup_queue(md
->queue
);
2051 dm_stats_cleanup(&md
->stats
);
2052 module_put(THIS_MODULE
);
2056 static void __bind_mempools(struct mapped_device
*md
, struct dm_table
*t
)
2058 struct dm_md_mempools
*p
= dm_table_get_md_mempools(t
);
2060 if (md
->io_pool
&& md
->bs
) {
2061 /* The md already has necessary mempools. */
2062 if (dm_table_get_type(t
) == DM_TYPE_BIO_BASED
) {
2064 * Reload bioset because front_pad may have changed
2065 * because a different table was loaded.
2067 bioset_free(md
->bs
);
2070 } else if (dm_table_get_type(t
) == DM_TYPE_REQUEST_BASED
) {
2072 * There's no need to reload with request-based dm
2073 * because the size of front_pad doesn't change.
2074 * Note for future: If you are to reload bioset,
2075 * prep-ed requests in the queue may refer
2076 * to bio from the old bioset, so you must walk
2077 * through the queue to unprep.
2083 BUG_ON(!p
|| md
->io_pool
|| md
->bs
);
2085 md
->io_pool
= p
->io_pool
;
2091 /* mempool bind completed, now no need any mempools in the table */
2092 dm_table_free_md_mempools(t
);
2096 * Bind a table to the device.
2098 static void event_callback(void *context
)
2100 unsigned long flags
;
2102 struct mapped_device
*md
= (struct mapped_device
*) context
;
2104 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2105 list_splice_init(&md
->uevent_list
, &uevents
);
2106 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2108 dm_send_uevents(&uevents
, &disk_to_dev(md
->disk
)->kobj
);
2110 atomic_inc(&md
->event_nr
);
2111 wake_up(&md
->eventq
);
2115 * Protected by md->suspend_lock obtained by dm_swap_table().
2117 static void __set_size(struct mapped_device
*md
, sector_t size
)
2119 set_capacity(md
->disk
, size
);
2121 i_size_write(md
->bdev
->bd_inode
, (loff_t
)size
<< SECTOR_SHIFT
);
2125 * Return 1 if the queue has a compulsory merge_bvec_fn function.
2127 * If this function returns 0, then the device is either a non-dm
2128 * device without a merge_bvec_fn, or it is a dm device that is
2129 * able to split any bios it receives that are too big.
2131 int dm_queue_merge_is_compulsory(struct request_queue
*q
)
2133 struct mapped_device
*dev_md
;
2135 if (!q
->merge_bvec_fn
)
2138 if (q
->make_request_fn
== dm_request
) {
2139 dev_md
= q
->queuedata
;
2140 if (test_bit(DMF_MERGE_IS_OPTIONAL
, &dev_md
->flags
))
2147 static int dm_device_merge_is_compulsory(struct dm_target
*ti
,
2148 struct dm_dev
*dev
, sector_t start
,
2149 sector_t len
, void *data
)
2151 struct block_device
*bdev
= dev
->bdev
;
2152 struct request_queue
*q
= bdev_get_queue(bdev
);
2154 return dm_queue_merge_is_compulsory(q
);
2158 * Return 1 if it is acceptable to ignore merge_bvec_fn based
2159 * on the properties of the underlying devices.
2161 static int dm_table_merge_is_optional(struct dm_table
*table
)
2164 struct dm_target
*ti
;
2166 while (i
< dm_table_get_num_targets(table
)) {
2167 ti
= dm_table_get_target(table
, i
++);
2169 if (ti
->type
->iterate_devices
&&
2170 ti
->type
->iterate_devices(ti
, dm_device_merge_is_compulsory
, NULL
))
2178 * Returns old map, which caller must destroy.
2180 static struct dm_table
*__bind(struct mapped_device
*md
, struct dm_table
*t
,
2181 struct queue_limits
*limits
)
2183 struct dm_table
*old_map
;
2184 struct request_queue
*q
= md
->queue
;
2186 int merge_is_optional
;
2188 size
= dm_table_get_size(t
);
2191 * Wipe any geometry if the size of the table changed.
2193 if (size
!= dm_get_size(md
))
2194 memset(&md
->geometry
, 0, sizeof(md
->geometry
));
2196 __set_size(md
, size
);
2198 dm_table_event_callback(t
, event_callback
, md
);
2201 * The queue hasn't been stopped yet, if the old table type wasn't
2202 * for request-based during suspension. So stop it to prevent
2203 * I/O mapping before resume.
2204 * This must be done before setting the queue restrictions,
2205 * because request-based dm may be run just after the setting.
2207 if (dm_table_request_based(t
) && !blk_queue_stopped(q
))
2210 __bind_mempools(md
, t
);
2212 merge_is_optional
= dm_table_merge_is_optional(t
);
2215 rcu_assign_pointer(md
->map
, t
);
2216 md
->immutable_target_type
= dm_table_get_immutable_target_type(t
);
2218 dm_table_set_restrictions(t
, q
, limits
);
2219 if (merge_is_optional
)
2220 set_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2222 clear_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2229 * Returns unbound table for the caller to free.
2231 static struct dm_table
*__unbind(struct mapped_device
*md
)
2233 struct dm_table
*map
= md
->map
;
2238 dm_table_event_callback(map
, NULL
, NULL
);
2239 RCU_INIT_POINTER(md
->map
, NULL
);
2246 * Constructor for a new device.
2248 int dm_create(int minor
, struct mapped_device
**result
)
2250 struct mapped_device
*md
;
2252 md
= alloc_dev(minor
);
2263 * Functions to manage md->type.
2264 * All are required to hold md->type_lock.
2266 void dm_lock_md_type(struct mapped_device
*md
)
2268 mutex_lock(&md
->type_lock
);
2271 void dm_unlock_md_type(struct mapped_device
*md
)
2273 mutex_unlock(&md
->type_lock
);
2276 void dm_set_md_type(struct mapped_device
*md
, unsigned type
)
2278 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2282 unsigned dm_get_md_type(struct mapped_device
*md
)
2284 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2288 struct target_type
*dm_get_immutable_target_type(struct mapped_device
*md
)
2290 return md
->immutable_target_type
;
2294 * The queue_limits are only valid as long as you have a reference
2297 struct queue_limits
*dm_get_queue_limits(struct mapped_device
*md
)
2299 BUG_ON(!atomic_read(&md
->holders
));
2300 return &md
->queue
->limits
;
2302 EXPORT_SYMBOL_GPL(dm_get_queue_limits
);
2305 * Fully initialize a request-based queue (->elevator, ->request_fn, etc).
2307 static int dm_init_request_based_queue(struct mapped_device
*md
)
2309 struct request_queue
*q
= NULL
;
2311 if (md
->queue
->elevator
)
2314 /* Fully initialize the queue */
2315 q
= blk_init_allocated_queue(md
->queue
, dm_request_fn
, NULL
);
2320 dm_init_md_queue(md
);
2321 blk_queue_softirq_done(md
->queue
, dm_softirq_done
);
2322 blk_queue_prep_rq(md
->queue
, dm_prep_fn
);
2323 blk_queue_lld_busy(md
->queue
, dm_lld_busy
);
2325 elv_register_queue(md
->queue
);
2331 * Setup the DM device's queue based on md's type
2333 int dm_setup_md_queue(struct mapped_device
*md
)
2335 if ((dm_get_md_type(md
) == DM_TYPE_REQUEST_BASED
) &&
2336 !dm_init_request_based_queue(md
)) {
2337 DMWARN("Cannot initialize queue for request-based mapped device");
2344 static struct mapped_device
*dm_find_md(dev_t dev
)
2346 struct mapped_device
*md
;
2347 unsigned minor
= MINOR(dev
);
2349 if (MAJOR(dev
) != _major
|| minor
>= (1 << MINORBITS
))
2352 spin_lock(&_minor_lock
);
2354 md
= idr_find(&_minor_idr
, minor
);
2355 if (md
&& (md
== MINOR_ALLOCED
||
2356 (MINOR(disk_devt(dm_disk(md
))) != minor
) ||
2357 dm_deleting_md(md
) ||
2358 test_bit(DMF_FREEING
, &md
->flags
))) {
2364 spin_unlock(&_minor_lock
);
2369 struct mapped_device
*dm_get_md(dev_t dev
)
2371 struct mapped_device
*md
= dm_find_md(dev
);
2378 EXPORT_SYMBOL_GPL(dm_get_md
);
2380 void *dm_get_mdptr(struct mapped_device
*md
)
2382 return md
->interface_ptr
;
2385 void dm_set_mdptr(struct mapped_device
*md
, void *ptr
)
2387 md
->interface_ptr
= ptr
;
2390 void dm_get(struct mapped_device
*md
)
2392 atomic_inc(&md
->holders
);
2393 BUG_ON(test_bit(DMF_FREEING
, &md
->flags
));
2396 const char *dm_device_name(struct mapped_device
*md
)
2400 EXPORT_SYMBOL_GPL(dm_device_name
);
2402 static void __dm_destroy(struct mapped_device
*md
, bool wait
)
2404 struct dm_table
*map
;
2409 spin_lock(&_minor_lock
);
2410 map
= dm_get_live_table(md
, &srcu_idx
);
2411 idr_replace(&_minor_idr
, MINOR_ALLOCED
, MINOR(disk_devt(dm_disk(md
))));
2412 set_bit(DMF_FREEING
, &md
->flags
);
2413 spin_unlock(&_minor_lock
);
2415 if (!dm_suspended_md(md
)) {
2416 dm_table_presuspend_targets(map
);
2417 dm_table_postsuspend_targets(map
);
2420 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2421 dm_put_live_table(md
, srcu_idx
);
2424 * Rare, but there may be I/O requests still going to complete,
2425 * for example. Wait for all references to disappear.
2426 * No one should increment the reference count of the mapped_device,
2427 * after the mapped_device state becomes DMF_FREEING.
2430 while (atomic_read(&md
->holders
))
2432 else if (atomic_read(&md
->holders
))
2433 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2434 dm_device_name(md
), atomic_read(&md
->holders
));
2437 dm_table_destroy(__unbind(md
));
2441 void dm_destroy(struct mapped_device
*md
)
2443 __dm_destroy(md
, true);
2446 void dm_destroy_immediate(struct mapped_device
*md
)
2448 __dm_destroy(md
, false);
2451 void dm_put(struct mapped_device
*md
)
2453 atomic_dec(&md
->holders
);
2455 EXPORT_SYMBOL_GPL(dm_put
);
2457 static int dm_wait_for_completion(struct mapped_device
*md
, int interruptible
)
2460 DECLARE_WAITQUEUE(wait
, current
);
2462 add_wait_queue(&md
->wait
, &wait
);
2465 set_current_state(interruptible
);
2467 if (!md_in_flight(md
))
2470 if (interruptible
== TASK_INTERRUPTIBLE
&&
2471 signal_pending(current
)) {
2478 set_current_state(TASK_RUNNING
);
2480 remove_wait_queue(&md
->wait
, &wait
);
2486 * Process the deferred bios
2488 static void dm_wq_work(struct work_struct
*work
)
2490 struct mapped_device
*md
= container_of(work
, struct mapped_device
,
2494 struct dm_table
*map
;
2496 map
= dm_get_live_table(md
, &srcu_idx
);
2498 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
2499 spin_lock_irq(&md
->deferred_lock
);
2500 c
= bio_list_pop(&md
->deferred
);
2501 spin_unlock_irq(&md
->deferred_lock
);
2506 if (dm_request_based(md
))
2507 generic_make_request(c
);
2509 __split_and_process_bio(md
, map
, c
);
2512 dm_put_live_table(md
, srcu_idx
);
2515 static void dm_queue_flush(struct mapped_device
*md
)
2517 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2518 smp_mb__after_atomic();
2519 queue_work(md
->wq
, &md
->work
);
2523 * Swap in a new table, returning the old one for the caller to destroy.
2525 struct dm_table
*dm_swap_table(struct mapped_device
*md
, struct dm_table
*table
)
2527 struct dm_table
*live_map
= NULL
, *map
= ERR_PTR(-EINVAL
);
2528 struct queue_limits limits
;
2531 mutex_lock(&md
->suspend_lock
);
2533 /* device must be suspended */
2534 if (!dm_suspended_md(md
))
2538 * If the new table has no data devices, retain the existing limits.
2539 * This helps multipath with queue_if_no_path if all paths disappear,
2540 * then new I/O is queued based on these limits, and then some paths
2543 if (dm_table_has_no_data_devices(table
)) {
2544 live_map
= dm_get_live_table_fast(md
);
2546 limits
= md
->queue
->limits
;
2547 dm_put_live_table_fast(md
);
2551 r
= dm_calculate_queue_limits(table
, &limits
);
2558 map
= __bind(md
, table
, &limits
);
2561 mutex_unlock(&md
->suspend_lock
);
2566 * Functions to lock and unlock any filesystem running on the
2569 static int lock_fs(struct mapped_device
*md
)
2573 WARN_ON(md
->frozen_sb
);
2575 md
->frozen_sb
= freeze_bdev(md
->bdev
);
2576 if (IS_ERR(md
->frozen_sb
)) {
2577 r
= PTR_ERR(md
->frozen_sb
);
2578 md
->frozen_sb
= NULL
;
2582 set_bit(DMF_FROZEN
, &md
->flags
);
2587 static void unlock_fs(struct mapped_device
*md
)
2589 if (!test_bit(DMF_FROZEN
, &md
->flags
))
2592 thaw_bdev(md
->bdev
, md
->frozen_sb
);
2593 md
->frozen_sb
= NULL
;
2594 clear_bit(DMF_FROZEN
, &md
->flags
);
2598 * We need to be able to change a mapping table under a mounted
2599 * filesystem. For example we might want to move some data in
2600 * the background. Before the table can be swapped with
2601 * dm_bind_table, dm_suspend must be called to flush any in
2602 * flight bios and ensure that any further io gets deferred.
2605 * Suspend mechanism in request-based dm.
2607 * 1. Flush all I/Os by lock_fs() if needed.
2608 * 2. Stop dispatching any I/O by stopping the request_queue.
2609 * 3. Wait for all in-flight I/Os to be completed or requeued.
2611 * To abort suspend, start the request_queue.
2613 int dm_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
2615 struct dm_table
*map
= NULL
;
2617 int do_lockfs
= suspend_flags
& DM_SUSPEND_LOCKFS_FLAG
? 1 : 0;
2618 int noflush
= suspend_flags
& DM_SUSPEND_NOFLUSH_FLAG
? 1 : 0;
2620 mutex_lock(&md
->suspend_lock
);
2622 if (dm_suspended_md(md
)) {
2630 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2631 * This flag is cleared before dm_suspend returns.
2634 set_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2636 /* This does not get reverted if there's an error later. */
2637 dm_table_presuspend_targets(map
);
2640 * Flush I/O to the device.
2641 * Any I/O submitted after lock_fs() may not be flushed.
2642 * noflush takes precedence over do_lockfs.
2643 * (lock_fs() flushes I/Os and waits for them to complete.)
2645 if (!noflush
&& do_lockfs
) {
2652 * Here we must make sure that no processes are submitting requests
2653 * to target drivers i.e. no one may be executing
2654 * __split_and_process_bio. This is called from dm_request and
2657 * To get all processes out of __split_and_process_bio in dm_request,
2658 * we take the write lock. To prevent any process from reentering
2659 * __split_and_process_bio from dm_request and quiesce the thread
2660 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2661 * flush_workqueue(md->wq).
2663 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2664 synchronize_srcu(&md
->io_barrier
);
2667 * Stop md->queue before flushing md->wq in case request-based
2668 * dm defers requests to md->wq from md->queue.
2670 if (dm_request_based(md
))
2671 stop_queue(md
->queue
);
2673 flush_workqueue(md
->wq
);
2676 * At this point no more requests are entering target request routines.
2677 * We call dm_wait_for_completion to wait for all existing requests
2680 r
= dm_wait_for_completion(md
, TASK_INTERRUPTIBLE
);
2683 clear_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2684 synchronize_srcu(&md
->io_barrier
);
2686 /* were we interrupted ? */
2690 if (dm_request_based(md
))
2691 start_queue(md
->queue
);
2694 goto out_unlock
; /* pushback list is already flushed, so skip flush */
2698 * If dm_wait_for_completion returned 0, the device is completely
2699 * quiescent now. There is no request-processing activity. All new
2700 * requests are being added to md->deferred list.
2703 set_bit(DMF_SUSPENDED
, &md
->flags
);
2705 dm_table_postsuspend_targets(map
);
2708 mutex_unlock(&md
->suspend_lock
);
2712 int dm_resume(struct mapped_device
*md
)
2715 struct dm_table
*map
= NULL
;
2717 mutex_lock(&md
->suspend_lock
);
2718 if (!dm_suspended_md(md
))
2722 if (!map
|| !dm_table_get_size(map
))
2725 r
= dm_table_resume_targets(map
);
2732 * Flushing deferred I/Os must be done after targets are resumed
2733 * so that mapping of targets can work correctly.
2734 * Request-based dm is queueing the deferred I/Os in its request_queue.
2736 if (dm_request_based(md
))
2737 start_queue(md
->queue
);
2741 clear_bit(DMF_SUSPENDED
, &md
->flags
);
2745 mutex_unlock(&md
->suspend_lock
);
2751 * Internal suspend/resume works like userspace-driven suspend. It waits
2752 * until all bios finish and prevents issuing new bios to the target drivers.
2753 * It may be used only from the kernel.
2755 * Internal suspend holds md->suspend_lock, which prevents interaction with
2756 * userspace-driven suspend.
2759 void dm_internal_suspend(struct mapped_device
*md
)
2761 mutex_lock(&md
->suspend_lock
);
2762 if (dm_suspended_md(md
))
2765 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2766 synchronize_srcu(&md
->io_barrier
);
2767 flush_workqueue(md
->wq
);
2768 dm_wait_for_completion(md
, TASK_UNINTERRUPTIBLE
);
2771 void dm_internal_resume(struct mapped_device
*md
)
2773 if (dm_suspended_md(md
))
2779 mutex_unlock(&md
->suspend_lock
);
2782 /*-----------------------------------------------------------------
2783 * Event notification.
2784 *---------------------------------------------------------------*/
2785 int dm_kobject_uevent(struct mapped_device
*md
, enum kobject_action action
,
2788 char udev_cookie
[DM_COOKIE_LENGTH
];
2789 char *envp
[] = { udev_cookie
, NULL
};
2792 return kobject_uevent(&disk_to_dev(md
->disk
)->kobj
, action
);
2794 snprintf(udev_cookie
, DM_COOKIE_LENGTH
, "%s=%u",
2795 DM_COOKIE_ENV_VAR_NAME
, cookie
);
2796 return kobject_uevent_env(&disk_to_dev(md
->disk
)->kobj
,
2801 uint32_t dm_next_uevent_seq(struct mapped_device
*md
)
2803 return atomic_add_return(1, &md
->uevent_seq
);
2806 uint32_t dm_get_event_nr(struct mapped_device
*md
)
2808 return atomic_read(&md
->event_nr
);
2811 int dm_wait_event(struct mapped_device
*md
, int event_nr
)
2813 return wait_event_interruptible(md
->eventq
,
2814 (event_nr
!= atomic_read(&md
->event_nr
)));
2817 void dm_uevent_add(struct mapped_device
*md
, struct list_head
*elist
)
2819 unsigned long flags
;
2821 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2822 list_add(elist
, &md
->uevent_list
);
2823 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2827 * The gendisk is only valid as long as you have a reference
2830 struct gendisk
*dm_disk(struct mapped_device
*md
)
2835 struct kobject
*dm_kobject(struct mapped_device
*md
)
2837 return &md
->kobj_holder
.kobj
;
2840 struct mapped_device
*dm_get_from_kobject(struct kobject
*kobj
)
2842 struct mapped_device
*md
;
2844 md
= container_of(kobj
, struct mapped_device
, kobj_holder
.kobj
);
2846 if (test_bit(DMF_FREEING
, &md
->flags
) ||
2854 int dm_suspended_md(struct mapped_device
*md
)
2856 return test_bit(DMF_SUSPENDED
, &md
->flags
);
2859 int dm_test_deferred_remove_flag(struct mapped_device
*md
)
2861 return test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
2864 int dm_suspended(struct dm_target
*ti
)
2866 return dm_suspended_md(dm_table_get_md(ti
->table
));
2868 EXPORT_SYMBOL_GPL(dm_suspended
);
2870 int dm_noflush_suspending(struct dm_target
*ti
)
2872 return __noflush_suspending(dm_table_get_md(ti
->table
));
2874 EXPORT_SYMBOL_GPL(dm_noflush_suspending
);
2876 struct dm_md_mempools
*dm_alloc_md_mempools(unsigned type
, unsigned integrity
, unsigned per_bio_data_size
)
2878 struct dm_md_mempools
*pools
= kzalloc(sizeof(*pools
), GFP_KERNEL
);
2879 struct kmem_cache
*cachep
;
2880 unsigned int pool_size
;
2881 unsigned int front_pad
;
2886 if (type
== DM_TYPE_BIO_BASED
) {
2888 pool_size
= dm_get_reserved_bio_based_ios();
2889 front_pad
= roundup(per_bio_data_size
, __alignof__(struct dm_target_io
)) + offsetof(struct dm_target_io
, clone
);
2890 } else if (type
== DM_TYPE_REQUEST_BASED
) {
2891 cachep
= _rq_tio_cache
;
2892 pool_size
= dm_get_reserved_rq_based_ios();
2893 front_pad
= offsetof(struct dm_rq_clone_bio_info
, clone
);
2894 /* per_bio_data_size is not used. See __bind_mempools(). */
2895 WARN_ON(per_bio_data_size
!= 0);
2899 pools
->io_pool
= mempool_create_slab_pool(pool_size
, cachep
);
2900 if (!pools
->io_pool
)
2903 pools
->bs
= bioset_create(pool_size
, front_pad
);
2907 if (integrity
&& bioset_integrity_create(pools
->bs
, pool_size
))
2913 dm_free_md_mempools(pools
);
2918 void dm_free_md_mempools(struct dm_md_mempools
*pools
)
2924 mempool_destroy(pools
->io_pool
);
2927 bioset_free(pools
->bs
);
2932 static const struct block_device_operations dm_blk_dops
= {
2933 .open
= dm_blk_open
,
2934 .release
= dm_blk_close
,
2935 .ioctl
= dm_blk_ioctl
,
2936 .getgeo
= dm_blk_getgeo
,
2937 .owner
= THIS_MODULE
2943 module_init(dm_init
);
2944 module_exit(dm_exit
);
2946 module_param(major
, uint
, 0);
2947 MODULE_PARM_DESC(major
, "The major number of the device mapper");
2949 module_param(reserved_bio_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
2950 MODULE_PARM_DESC(reserved_bio_based_ios
, "Reserved IOs in bio-based mempools");
2952 module_param(reserved_rq_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
2953 MODULE_PARM_DESC(reserved_rq_based_ios
, "Reserved IOs in request-based mempools");
2955 MODULE_DESCRIPTION(DM_NAME
" driver");
2956 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
2957 MODULE_LICENSE("GPL");