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
);
59 * One of these is allocated per bio.
62 struct mapped_device
*md
;
66 unsigned long start_time
;
67 spinlock_t endio_lock
;
68 struct dm_stats_aux stats_aux
;
72 * For request-based dm.
73 * One of these is allocated per request.
75 struct dm_rq_target_io
{
76 struct mapped_device
*md
;
78 struct request
*orig
, clone
;
84 * For request-based dm - the bio clones we allocate are embedded in these
87 * We allocate these with bio_alloc_bioset, using the front_pad parameter when
88 * the bioset is created - this means the bio has to come at the end of the
91 struct dm_rq_clone_bio_info
{
93 struct dm_rq_target_io
*tio
;
97 union map_info
*dm_get_rq_mapinfo(struct request
*rq
)
99 if (rq
&& rq
->end_io_data
)
100 return &((struct dm_rq_target_io
*)rq
->end_io_data
)->info
;
103 EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo
);
105 #define MINOR_ALLOCED ((void *)-1)
108 * Bits for the md->flags field.
110 #define DMF_BLOCK_IO_FOR_SUSPEND 0
111 #define DMF_SUSPENDED 1
113 #define DMF_FREEING 3
114 #define DMF_DELETING 4
115 #define DMF_NOFLUSH_SUSPENDING 5
116 #define DMF_MERGE_IS_OPTIONAL 6
117 #define DMF_DEFERRED_REMOVE 7
120 * A dummy definition to make RCU happy.
121 * struct dm_table should never be dereferenced in this file.
128 * Work processed by per-device workqueue.
130 struct mapped_device
{
131 struct srcu_struct io_barrier
;
132 struct mutex suspend_lock
;
137 * The current mapping.
138 * Use dm_get_live_table{_fast} or take suspend_lock for
141 struct dm_table
*map
;
145 struct request_queue
*queue
;
147 /* Protect queue and type against concurrent access. */
148 struct mutex type_lock
;
150 struct target_type
*immutable_target_type
;
152 struct gendisk
*disk
;
158 * A list of ios that arrived while we were suspended.
161 wait_queue_head_t wait
;
162 struct work_struct work
;
163 struct bio_list deferred
;
164 spinlock_t deferred_lock
;
167 * Processing queue (flush)
169 struct workqueue_struct
*wq
;
172 * io objects are allocated from here.
182 wait_queue_head_t eventq
;
184 struct list_head uevent_list
;
185 spinlock_t uevent_lock
; /* Protect access to uevent_list */
188 * freeze/thaw support require holding onto a super block
190 struct super_block
*frozen_sb
;
191 struct block_device
*bdev
;
193 /* forced geometry settings */
194 struct hd_geometry geometry
;
196 /* kobject and completion */
197 struct dm_kobject_holder kobj_holder
;
199 /* zero-length flush that will be cloned and submitted to targets */
200 struct bio flush_bio
;
202 struct dm_stats stats
;
206 * For mempools pre-allocation at the table loading time.
208 struct dm_md_mempools
{
213 #define RESERVED_BIO_BASED_IOS 16
214 #define RESERVED_REQUEST_BASED_IOS 256
215 #define RESERVED_MAX_IOS 1024
216 static struct kmem_cache
*_io_cache
;
217 static struct kmem_cache
*_rq_tio_cache
;
220 * Bio-based DM's mempools' reserved IOs set by the user.
222 static unsigned reserved_bio_based_ios
= RESERVED_BIO_BASED_IOS
;
225 * Request-based DM's mempools' reserved IOs set by the user.
227 static unsigned reserved_rq_based_ios
= RESERVED_REQUEST_BASED_IOS
;
229 static unsigned __dm_get_reserved_ios(unsigned *reserved_ios
,
230 unsigned def
, unsigned max
)
232 unsigned ios
= ACCESS_ONCE(*reserved_ios
);
233 unsigned modified_ios
= 0;
241 (void)cmpxchg(reserved_ios
, ios
, modified_ios
);
248 unsigned dm_get_reserved_bio_based_ios(void)
250 return __dm_get_reserved_ios(&reserved_bio_based_ios
,
251 RESERVED_BIO_BASED_IOS
, RESERVED_MAX_IOS
);
253 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios
);
255 unsigned dm_get_reserved_rq_based_ios(void)
257 return __dm_get_reserved_ios(&reserved_rq_based_ios
,
258 RESERVED_REQUEST_BASED_IOS
, RESERVED_MAX_IOS
);
260 EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios
);
262 static int __init
local_init(void)
266 /* allocate a slab for the dm_ios */
267 _io_cache
= KMEM_CACHE(dm_io
, 0);
271 _rq_tio_cache
= KMEM_CACHE(dm_rq_target_io
, 0);
273 goto out_free_io_cache
;
275 r
= dm_uevent_init();
277 goto out_free_rq_tio_cache
;
280 r
= register_blkdev(_major
, _name
);
282 goto out_uevent_exit
;
291 out_free_rq_tio_cache
:
292 kmem_cache_destroy(_rq_tio_cache
);
294 kmem_cache_destroy(_io_cache
);
299 static void local_exit(void)
301 flush_scheduled_work();
303 kmem_cache_destroy(_rq_tio_cache
);
304 kmem_cache_destroy(_io_cache
);
305 unregister_blkdev(_major
, _name
);
310 DMINFO("cleaned up");
313 static int (*_inits
[])(void) __initdata
= {
324 static void (*_exits
[])(void) = {
335 static int __init
dm_init(void)
337 const int count
= ARRAY_SIZE(_inits
);
341 for (i
= 0; i
< count
; i
++) {
356 static void __exit
dm_exit(void)
358 int i
= ARRAY_SIZE(_exits
);
364 * Should be empty by this point.
366 idr_destroy(&_minor_idr
);
370 * Block device functions
372 int dm_deleting_md(struct mapped_device
*md
)
374 return test_bit(DMF_DELETING
, &md
->flags
);
377 static int dm_blk_open(struct block_device
*bdev
, fmode_t mode
)
379 struct mapped_device
*md
;
381 spin_lock(&_minor_lock
);
383 md
= bdev
->bd_disk
->private_data
;
387 if (test_bit(DMF_FREEING
, &md
->flags
) ||
388 dm_deleting_md(md
)) {
394 atomic_inc(&md
->open_count
);
397 spin_unlock(&_minor_lock
);
399 return md
? 0 : -ENXIO
;
402 static void dm_blk_close(struct gendisk
*disk
, fmode_t mode
)
404 struct mapped_device
*md
= disk
->private_data
;
406 spin_lock(&_minor_lock
);
408 if (atomic_dec_and_test(&md
->open_count
) &&
409 (test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
)))
410 schedule_work(&deferred_remove_work
);
414 spin_unlock(&_minor_lock
);
417 int dm_open_count(struct mapped_device
*md
)
419 return atomic_read(&md
->open_count
);
423 * Guarantees nothing is using the device before it's deleted.
425 int dm_lock_for_deletion(struct mapped_device
*md
, bool mark_deferred
, bool only_deferred
)
429 spin_lock(&_minor_lock
);
431 if (dm_open_count(md
)) {
434 set_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
435 } else if (only_deferred
&& !test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
))
438 set_bit(DMF_DELETING
, &md
->flags
);
440 spin_unlock(&_minor_lock
);
445 int dm_cancel_deferred_remove(struct mapped_device
*md
)
449 spin_lock(&_minor_lock
);
451 if (test_bit(DMF_DELETING
, &md
->flags
))
454 clear_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
456 spin_unlock(&_minor_lock
);
461 static void do_deferred_remove(struct work_struct
*w
)
463 dm_deferred_remove();
466 sector_t
dm_get_size(struct mapped_device
*md
)
468 return get_capacity(md
->disk
);
471 struct request_queue
*dm_get_md_queue(struct mapped_device
*md
)
476 struct dm_stats
*dm_get_stats(struct mapped_device
*md
)
481 static int dm_blk_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
483 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
485 return dm_get_geometry(md
, geo
);
488 static int dm_blk_ioctl(struct block_device
*bdev
, fmode_t mode
,
489 unsigned int cmd
, unsigned long arg
)
491 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
493 struct dm_table
*map
;
494 struct dm_target
*tgt
;
498 map
= dm_get_live_table(md
, &srcu_idx
);
500 if (!map
|| !dm_table_get_size(map
))
503 /* We only support devices that have a single target */
504 if (dm_table_get_num_targets(map
) != 1)
507 tgt
= dm_table_get_target(map
, 0);
509 if (dm_suspended_md(md
)) {
514 if (tgt
->type
->ioctl
)
515 r
= tgt
->type
->ioctl(tgt
, cmd
, arg
);
518 dm_put_live_table(md
, srcu_idx
);
520 if (r
== -ENOTCONN
) {
528 static struct dm_io
*alloc_io(struct mapped_device
*md
)
530 return mempool_alloc(md
->io_pool
, GFP_NOIO
);
533 static void free_io(struct mapped_device
*md
, struct dm_io
*io
)
535 mempool_free(io
, md
->io_pool
);
538 static void free_tio(struct mapped_device
*md
, struct dm_target_io
*tio
)
540 bio_put(&tio
->clone
);
543 static struct dm_rq_target_io
*alloc_rq_tio(struct mapped_device
*md
,
546 return mempool_alloc(md
->io_pool
, gfp_mask
);
549 static void free_rq_tio(struct dm_rq_target_io
*tio
)
551 mempool_free(tio
, tio
->md
->io_pool
);
554 static int md_in_flight(struct mapped_device
*md
)
556 return atomic_read(&md
->pending
[READ
]) +
557 atomic_read(&md
->pending
[WRITE
]);
560 static void start_io_acct(struct dm_io
*io
)
562 struct mapped_device
*md
= io
->md
;
563 struct bio
*bio
= io
->bio
;
565 int rw
= bio_data_dir(bio
);
567 io
->start_time
= jiffies
;
569 cpu
= part_stat_lock();
570 part_round_stats(cpu
, &dm_disk(md
)->part0
);
572 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
],
573 atomic_inc_return(&md
->pending
[rw
]));
575 if (unlikely(dm_stats_used(&md
->stats
)))
576 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
577 bio_sectors(bio
), false, 0, &io
->stats_aux
);
580 static void end_io_acct(struct dm_io
*io
)
582 struct mapped_device
*md
= io
->md
;
583 struct bio
*bio
= io
->bio
;
584 unsigned long duration
= jiffies
- io
->start_time
;
586 int rw
= bio_data_dir(bio
);
588 cpu
= part_stat_lock();
589 part_round_stats(cpu
, &dm_disk(md
)->part0
);
590 part_stat_add(cpu
, &dm_disk(md
)->part0
, ticks
[rw
], duration
);
593 if (unlikely(dm_stats_used(&md
->stats
)))
594 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
595 bio_sectors(bio
), true, duration
, &io
->stats_aux
);
598 * After this is decremented the bio must not be touched if it is
601 pending
= atomic_dec_return(&md
->pending
[rw
]);
602 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
], pending
);
603 pending
+= atomic_read(&md
->pending
[rw
^0x1]);
605 /* nudge anyone waiting on suspend queue */
611 * Add the bio to the list of deferred io.
613 static void queue_io(struct mapped_device
*md
, struct bio
*bio
)
617 spin_lock_irqsave(&md
->deferred_lock
, flags
);
618 bio_list_add(&md
->deferred
, bio
);
619 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
620 queue_work(md
->wq
, &md
->work
);
624 * Everyone (including functions in this file), should use this
625 * function to access the md->map field, and make sure they call
626 * dm_put_live_table() when finished.
628 struct dm_table
*dm_get_live_table(struct mapped_device
*md
, int *srcu_idx
) __acquires(md
->io_barrier
)
630 *srcu_idx
= srcu_read_lock(&md
->io_barrier
);
632 return srcu_dereference(md
->map
, &md
->io_barrier
);
635 void dm_put_live_table(struct mapped_device
*md
, int srcu_idx
) __releases(md
->io_barrier
)
637 srcu_read_unlock(&md
->io_barrier
, srcu_idx
);
640 void dm_sync_table(struct mapped_device
*md
)
642 synchronize_srcu(&md
->io_barrier
);
643 synchronize_rcu_expedited();
647 * A fast alternative to dm_get_live_table/dm_put_live_table.
648 * The caller must not block between these two functions.
650 static struct dm_table
*dm_get_live_table_fast(struct mapped_device
*md
) __acquires(RCU
)
653 return rcu_dereference(md
->map
);
656 static void dm_put_live_table_fast(struct mapped_device
*md
) __releases(RCU
)
662 * Get the geometry associated with a dm device
664 int dm_get_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
672 * Set the geometry of a device.
674 int dm_set_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
676 sector_t sz
= (sector_t
)geo
->cylinders
* geo
->heads
* geo
->sectors
;
678 if (geo
->start
> sz
) {
679 DMWARN("Start sector is beyond the geometry limits.");
688 /*-----------------------------------------------------------------
690 * A more elegant soln is in the works that uses the queue
691 * merge fn, unfortunately there are a couple of changes to
692 * the block layer that I want to make for this. So in the
693 * interests of getting something for people to use I give
694 * you this clearly demarcated crap.
695 *---------------------------------------------------------------*/
697 static int __noflush_suspending(struct mapped_device
*md
)
699 return test_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
703 * Decrements the number of outstanding ios that a bio has been
704 * cloned into, completing the original io if necc.
706 static void dec_pending(struct dm_io
*io
, int error
)
711 struct mapped_device
*md
= io
->md
;
713 /* Push-back supersedes any I/O errors */
714 if (unlikely(error
)) {
715 spin_lock_irqsave(&io
->endio_lock
, flags
);
716 if (!(io
->error
> 0 && __noflush_suspending(md
)))
718 spin_unlock_irqrestore(&io
->endio_lock
, flags
);
721 if (atomic_dec_and_test(&io
->io_count
)) {
722 if (io
->error
== DM_ENDIO_REQUEUE
) {
724 * Target requested pushing back the I/O.
726 spin_lock_irqsave(&md
->deferred_lock
, flags
);
727 if (__noflush_suspending(md
))
728 bio_list_add_head(&md
->deferred
, io
->bio
);
730 /* noflush suspend was interrupted. */
732 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
735 io_error
= io
->error
;
740 if (io_error
== DM_ENDIO_REQUEUE
)
743 if ((bio
->bi_rw
& REQ_FLUSH
) && bio
->bi_iter
.bi_size
) {
745 * Preflush done for flush with data, reissue
748 bio
->bi_rw
&= ~REQ_FLUSH
;
751 /* done with normal IO or empty flush */
752 trace_block_bio_complete(md
->queue
, bio
, io_error
);
753 bio_endio(bio
, io_error
);
758 static void clone_endio(struct bio
*bio
, int error
)
761 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
762 struct dm_io
*io
= tio
->io
;
763 struct mapped_device
*md
= tio
->io
->md
;
764 dm_endio_fn endio
= tio
->ti
->type
->end_io
;
766 if (!bio_flagged(bio
, BIO_UPTODATE
) && !error
)
770 r
= endio(tio
->ti
, bio
, error
);
771 if (r
< 0 || r
== DM_ENDIO_REQUEUE
)
773 * error and requeue request are handled
777 else if (r
== DM_ENDIO_INCOMPLETE
)
778 /* The target will handle the io */
781 DMWARN("unimplemented target endio return value: %d", r
);
787 dec_pending(io
, error
);
791 * Partial completion handling for request-based dm
793 static void end_clone_bio(struct bio
*clone
, int error
)
795 struct dm_rq_clone_bio_info
*info
=
796 container_of(clone
, struct dm_rq_clone_bio_info
, clone
);
797 struct dm_rq_target_io
*tio
= info
->tio
;
798 struct bio
*bio
= info
->orig
;
799 unsigned int nr_bytes
= info
->orig
->bi_iter
.bi_size
;
805 * An error has already been detected on the request.
806 * Once error occurred, just let clone->end_io() handle
812 * Don't notice the error to the upper layer yet.
813 * The error handling decision is made by the target driver,
814 * when the request is completed.
821 * I/O for the bio successfully completed.
822 * Notice the data completion to the upper layer.
826 * bios are processed from the head of the list.
827 * So the completing bio should always be rq->bio.
828 * If it's not, something wrong is happening.
830 if (tio
->orig
->bio
!= bio
)
831 DMERR("bio completion is going in the middle of the request");
834 * Update the original request.
835 * Do not use blk_end_request() here, because it may complete
836 * the original request before the clone, and break the ordering.
838 blk_update_request(tio
->orig
, 0, nr_bytes
);
842 * Don't touch any member of the md after calling this function because
843 * the md may be freed in dm_put() at the end of this function.
844 * Or do dm_get() before calling this function and dm_put() later.
846 static void rq_completed(struct mapped_device
*md
, int rw
, int run_queue
)
848 atomic_dec(&md
->pending
[rw
]);
850 /* nudge anyone waiting on suspend queue */
851 if (!md_in_flight(md
))
855 * Run this off this callpath, as drivers could invoke end_io while
856 * inside their request_fn (and holding the queue lock). Calling
857 * back into ->request_fn() could deadlock attempting to grab the
861 blk_run_queue_async(md
->queue
);
864 * dm_put() must be at the end of this function. See the comment above
869 static void free_rq_clone(struct request
*clone
)
871 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
873 blk_rq_unprep_clone(clone
);
878 * Complete the clone and the original request.
879 * Must be called without queue lock.
881 static void dm_end_request(struct request
*clone
, int error
)
883 int rw
= rq_data_dir(clone
);
884 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
885 struct mapped_device
*md
= tio
->md
;
886 struct request
*rq
= tio
->orig
;
888 if (rq
->cmd_type
== REQ_TYPE_BLOCK_PC
) {
889 rq
->errors
= clone
->errors
;
890 rq
->resid_len
= clone
->resid_len
;
894 * We are using the sense buffer of the original
896 * So setting the length of the sense data is enough.
898 rq
->sense_len
= clone
->sense_len
;
901 free_rq_clone(clone
);
902 blk_end_request_all(rq
, error
);
903 rq_completed(md
, rw
, true);
906 static void dm_unprep_request(struct request
*rq
)
908 struct request
*clone
= rq
->special
;
911 rq
->cmd_flags
&= ~REQ_DONTPREP
;
913 free_rq_clone(clone
);
917 * Requeue the original request of a clone.
919 void dm_requeue_unmapped_request(struct request
*clone
)
921 int rw
= rq_data_dir(clone
);
922 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
923 struct mapped_device
*md
= tio
->md
;
924 struct request
*rq
= tio
->orig
;
925 struct request_queue
*q
= rq
->q
;
928 dm_unprep_request(rq
);
930 spin_lock_irqsave(q
->queue_lock
, flags
);
931 blk_requeue_request(q
, rq
);
932 spin_unlock_irqrestore(q
->queue_lock
, flags
);
934 rq_completed(md
, rw
, 0);
936 EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request
);
938 static void __stop_queue(struct request_queue
*q
)
943 static void stop_queue(struct request_queue
*q
)
947 spin_lock_irqsave(q
->queue_lock
, flags
);
949 spin_unlock_irqrestore(q
->queue_lock
, flags
);
952 static void __start_queue(struct request_queue
*q
)
954 if (blk_queue_stopped(q
))
958 static void start_queue(struct request_queue
*q
)
962 spin_lock_irqsave(q
->queue_lock
, flags
);
964 spin_unlock_irqrestore(q
->queue_lock
, flags
);
967 static void dm_done(struct request
*clone
, int error
, bool mapped
)
970 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
971 dm_request_endio_fn rq_end_io
= NULL
;
974 rq_end_io
= tio
->ti
->type
->rq_end_io
;
976 if (mapped
&& rq_end_io
)
977 r
= rq_end_io(tio
->ti
, clone
, error
, &tio
->info
);
981 /* The target wants to complete the I/O */
982 dm_end_request(clone
, r
);
983 else if (r
== DM_ENDIO_INCOMPLETE
)
984 /* The target will handle the I/O */
986 else if (r
== DM_ENDIO_REQUEUE
)
987 /* The target wants to requeue the I/O */
988 dm_requeue_unmapped_request(clone
);
990 DMWARN("unimplemented target endio return value: %d", r
);
996 * Request completion handler for request-based dm
998 static void dm_softirq_done(struct request
*rq
)
1001 struct request
*clone
= rq
->completion_data
;
1002 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1004 if (rq
->cmd_flags
& REQ_FAILED
)
1007 dm_done(clone
, tio
->error
, mapped
);
1011 * Complete the clone and the original request with the error status
1012 * through softirq context.
1014 static void dm_complete_request(struct request
*clone
, int error
)
1016 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1017 struct request
*rq
= tio
->orig
;
1020 rq
->completion_data
= clone
;
1021 blk_complete_request(rq
);
1025 * Complete the not-mapped clone and the original request with the error status
1026 * through softirq context.
1027 * Target's rq_end_io() function isn't called.
1028 * This may be used when the target's map_rq() function fails.
1030 void dm_kill_unmapped_request(struct request
*clone
, int error
)
1032 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1033 struct request
*rq
= tio
->orig
;
1035 rq
->cmd_flags
|= REQ_FAILED
;
1036 dm_complete_request(clone
, error
);
1038 EXPORT_SYMBOL_GPL(dm_kill_unmapped_request
);
1041 * Called with the queue lock held
1043 static void end_clone_request(struct request
*clone
, int error
)
1046 * For just cleaning up the information of the queue in which
1047 * the clone was dispatched.
1048 * The clone is *NOT* freed actually here because it is alloced from
1049 * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags.
1051 __blk_put_request(clone
->q
, clone
);
1054 * Actual request completion is done in a softirq context which doesn't
1055 * hold the queue lock. Otherwise, deadlock could occur because:
1056 * - another request may be submitted by the upper level driver
1057 * of the stacking during the completion
1058 * - the submission which requires queue lock may be done
1059 * against this queue
1061 dm_complete_request(clone
, error
);
1065 * Return maximum size of I/O possible at the supplied sector up to the current
1068 static sector_t
max_io_len_target_boundary(sector_t sector
, struct dm_target
*ti
)
1070 sector_t target_offset
= dm_target_offset(ti
, sector
);
1072 return ti
->len
- target_offset
;
1075 static sector_t
max_io_len(sector_t sector
, struct dm_target
*ti
)
1077 sector_t len
= max_io_len_target_boundary(sector
, ti
);
1078 sector_t offset
, max_len
;
1081 * Does the target need to split even further?
1083 if (ti
->max_io_len
) {
1084 offset
= dm_target_offset(ti
, sector
);
1085 if (unlikely(ti
->max_io_len
& (ti
->max_io_len
- 1)))
1086 max_len
= sector_div(offset
, ti
->max_io_len
);
1088 max_len
= offset
& (ti
->max_io_len
- 1);
1089 max_len
= ti
->max_io_len
- max_len
;
1098 int dm_set_target_max_io_len(struct dm_target
*ti
, sector_t len
)
1100 if (len
> UINT_MAX
) {
1101 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1102 (unsigned long long)len
, UINT_MAX
);
1103 ti
->error
= "Maximum size of target IO is too large";
1107 ti
->max_io_len
= (uint32_t) len
;
1111 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len
);
1113 static void __map_bio(struct dm_target_io
*tio
)
1117 struct mapped_device
*md
;
1118 struct bio
*clone
= &tio
->clone
;
1119 struct dm_target
*ti
= tio
->ti
;
1121 clone
->bi_end_io
= clone_endio
;
1124 * Map the clone. If r == 0 we don't need to do
1125 * anything, the target has assumed ownership of
1128 atomic_inc(&tio
->io
->io_count
);
1129 sector
= clone
->bi_iter
.bi_sector
;
1130 r
= ti
->type
->map(ti
, clone
);
1131 if (r
== DM_MAPIO_REMAPPED
) {
1132 /* the bio has been remapped so dispatch it */
1134 trace_block_bio_remap(bdev_get_queue(clone
->bi_bdev
), clone
,
1135 tio
->io
->bio
->bi_bdev
->bd_dev
, sector
);
1137 generic_make_request(clone
);
1138 } else if (r
< 0 || r
== DM_MAPIO_REQUEUE
) {
1139 /* error the io and bail out, or requeue it if needed */
1141 dec_pending(tio
->io
, r
);
1144 DMWARN("unimplemented target map return value: %d", r
);
1150 struct mapped_device
*md
;
1151 struct dm_table
*map
;
1155 sector_t sector_count
;
1158 static void bio_setup_sector(struct bio
*bio
, sector_t sector
, sector_t len
)
1160 bio
->bi_iter
.bi_sector
= sector
;
1161 bio
->bi_iter
.bi_size
= to_bytes(len
);
1165 * Creates a bio that consists of range of complete bvecs.
1167 static void clone_bio(struct dm_target_io
*tio
, struct bio
*bio
,
1168 sector_t sector
, unsigned len
)
1170 struct bio
*clone
= &tio
->clone
;
1172 __bio_clone_fast(clone
, bio
);
1174 if (bio_integrity(bio
))
1175 bio_integrity_clone(clone
, bio
, GFP_NOIO
);
1177 bio_advance(clone
, to_bytes(sector
- clone
->bi_iter
.bi_sector
));
1178 clone
->bi_iter
.bi_size
= to_bytes(len
);
1180 if (bio_integrity(bio
))
1181 bio_integrity_trim(clone
, 0, len
);
1184 static struct dm_target_io
*alloc_tio(struct clone_info
*ci
,
1185 struct dm_target
*ti
, int nr_iovecs
,
1186 unsigned target_bio_nr
)
1188 struct dm_target_io
*tio
;
1191 clone
= bio_alloc_bioset(GFP_NOIO
, nr_iovecs
, ci
->md
->bs
);
1192 tio
= container_of(clone
, struct dm_target_io
, clone
);
1196 tio
->target_bio_nr
= target_bio_nr
;
1201 static void __clone_and_map_simple_bio(struct clone_info
*ci
,
1202 struct dm_target
*ti
,
1203 unsigned target_bio_nr
, sector_t len
)
1205 struct dm_target_io
*tio
= alloc_tio(ci
, ti
, ci
->bio
->bi_max_vecs
, target_bio_nr
);
1206 struct bio
*clone
= &tio
->clone
;
1209 * Discard requests require the bio's inline iovecs be initialized.
1210 * ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush
1211 * and discard, so no need for concern about wasted bvec allocations.
1213 __bio_clone_fast(clone
, ci
->bio
);
1215 bio_setup_sector(clone
, ci
->sector
, len
);
1220 static void __send_duplicate_bios(struct clone_info
*ci
, struct dm_target
*ti
,
1221 unsigned num_bios
, sector_t len
)
1223 unsigned target_bio_nr
;
1225 for (target_bio_nr
= 0; target_bio_nr
< num_bios
; target_bio_nr
++)
1226 __clone_and_map_simple_bio(ci
, ti
, target_bio_nr
, len
);
1229 static int __send_empty_flush(struct clone_info
*ci
)
1231 unsigned target_nr
= 0;
1232 struct dm_target
*ti
;
1234 BUG_ON(bio_has_data(ci
->bio
));
1235 while ((ti
= dm_table_get_target(ci
->map
, target_nr
++)))
1236 __send_duplicate_bios(ci
, ti
, ti
->num_flush_bios
, 0);
1241 static void __clone_and_map_data_bio(struct clone_info
*ci
, struct dm_target
*ti
,
1242 sector_t sector
, unsigned len
)
1244 struct bio
*bio
= ci
->bio
;
1245 struct dm_target_io
*tio
;
1246 unsigned target_bio_nr
;
1247 unsigned num_target_bios
= 1;
1250 * Does the target want to receive duplicate copies of the bio?
1252 if (bio_data_dir(bio
) == WRITE
&& ti
->num_write_bios
)
1253 num_target_bios
= ti
->num_write_bios(ti
, bio
);
1255 for (target_bio_nr
= 0; target_bio_nr
< num_target_bios
; target_bio_nr
++) {
1256 tio
= alloc_tio(ci
, ti
, 0, target_bio_nr
);
1257 clone_bio(tio
, bio
, sector
, len
);
1262 typedef unsigned (*get_num_bios_fn
)(struct dm_target
*ti
);
1264 static unsigned get_num_discard_bios(struct dm_target
*ti
)
1266 return ti
->num_discard_bios
;
1269 static unsigned get_num_write_same_bios(struct dm_target
*ti
)
1271 return ti
->num_write_same_bios
;
1274 typedef bool (*is_split_required_fn
)(struct dm_target
*ti
);
1276 static bool is_split_required_for_discard(struct dm_target
*ti
)
1278 return ti
->split_discard_bios
;
1281 static int __send_changing_extent_only(struct clone_info
*ci
,
1282 get_num_bios_fn get_num_bios
,
1283 is_split_required_fn is_split_required
)
1285 struct dm_target
*ti
;
1290 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1291 if (!dm_target_is_valid(ti
))
1295 * Even though the device advertised support for this type of
1296 * request, that does not mean every target supports it, and
1297 * reconfiguration might also have changed that since the
1298 * check was performed.
1300 num_bios
= get_num_bios
? get_num_bios(ti
) : 0;
1304 if (is_split_required
&& !is_split_required(ti
))
1305 len
= min(ci
->sector_count
, max_io_len_target_boundary(ci
->sector
, ti
));
1307 len
= min(ci
->sector_count
, max_io_len(ci
->sector
, ti
));
1309 __send_duplicate_bios(ci
, ti
, num_bios
, len
);
1312 } while (ci
->sector_count
-= len
);
1317 static int __send_discard(struct clone_info
*ci
)
1319 return __send_changing_extent_only(ci
, get_num_discard_bios
,
1320 is_split_required_for_discard
);
1323 static int __send_write_same(struct clone_info
*ci
)
1325 return __send_changing_extent_only(ci
, get_num_write_same_bios
, NULL
);
1329 * Select the correct strategy for processing a non-flush bio.
1331 static int __split_and_process_non_flush(struct clone_info
*ci
)
1333 struct bio
*bio
= ci
->bio
;
1334 struct dm_target
*ti
;
1337 if (unlikely(bio
->bi_rw
& REQ_DISCARD
))
1338 return __send_discard(ci
);
1339 else if (unlikely(bio
->bi_rw
& REQ_WRITE_SAME
))
1340 return __send_write_same(ci
);
1342 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1343 if (!dm_target_is_valid(ti
))
1346 len
= min_t(sector_t
, max_io_len(ci
->sector
, ti
), ci
->sector_count
);
1348 __clone_and_map_data_bio(ci
, ti
, ci
->sector
, len
);
1351 ci
->sector_count
-= len
;
1357 * Entry point to split a bio into clones and submit them to the targets.
1359 static void __split_and_process_bio(struct mapped_device
*md
,
1360 struct dm_table
*map
, struct bio
*bio
)
1362 struct clone_info ci
;
1365 if (unlikely(!map
)) {
1372 ci
.io
= alloc_io(md
);
1374 atomic_set(&ci
.io
->io_count
, 1);
1377 spin_lock_init(&ci
.io
->endio_lock
);
1378 ci
.sector
= bio
->bi_iter
.bi_sector
;
1380 start_io_acct(ci
.io
);
1382 if (bio
->bi_rw
& REQ_FLUSH
) {
1383 ci
.bio
= &ci
.md
->flush_bio
;
1384 ci
.sector_count
= 0;
1385 error
= __send_empty_flush(&ci
);
1386 /* dec_pending submits any data associated with flush */
1389 ci
.sector_count
= bio_sectors(bio
);
1390 while (ci
.sector_count
&& !error
)
1391 error
= __split_and_process_non_flush(&ci
);
1394 /* drop the extra reference count */
1395 dec_pending(ci
.io
, error
);
1397 /*-----------------------------------------------------------------
1399 *---------------------------------------------------------------*/
1401 static int dm_merge_bvec(struct request_queue
*q
,
1402 struct bvec_merge_data
*bvm
,
1403 struct bio_vec
*biovec
)
1405 struct mapped_device
*md
= q
->queuedata
;
1406 struct dm_table
*map
= dm_get_live_table_fast(md
);
1407 struct dm_target
*ti
;
1408 sector_t max_sectors
;
1414 ti
= dm_table_find_target(map
, bvm
->bi_sector
);
1415 if (!dm_target_is_valid(ti
))
1419 * Find maximum amount of I/O that won't need splitting
1421 max_sectors
= min(max_io_len(bvm
->bi_sector
, ti
),
1422 (sector_t
) BIO_MAX_SECTORS
);
1423 max_size
= (max_sectors
<< SECTOR_SHIFT
) - bvm
->bi_size
;
1428 * merge_bvec_fn() returns number of bytes
1429 * it can accept at this offset
1430 * max is precomputed maximal io size
1432 if (max_size
&& ti
->type
->merge
)
1433 max_size
= ti
->type
->merge(ti
, bvm
, biovec
, max_size
);
1435 * If the target doesn't support merge method and some of the devices
1436 * provided their merge_bvec method (we know this by looking at
1437 * queue_max_hw_sectors), then we can't allow bios with multiple vector
1438 * entries. So always set max_size to 0, and the code below allows
1441 else if (queue_max_hw_sectors(q
) <= PAGE_SIZE
>> 9)
1446 dm_put_live_table_fast(md
);
1448 * Always allow an entire first page
1450 if (max_size
<= biovec
->bv_len
&& !(bvm
->bi_size
>> SECTOR_SHIFT
))
1451 max_size
= biovec
->bv_len
;
1457 * The request function that just remaps the bio built up by
1460 static void _dm_request(struct request_queue
*q
, struct bio
*bio
)
1462 int rw
= bio_data_dir(bio
);
1463 struct mapped_device
*md
= q
->queuedata
;
1466 struct dm_table
*map
;
1468 map
= dm_get_live_table(md
, &srcu_idx
);
1470 cpu
= part_stat_lock();
1471 part_stat_inc(cpu
, &dm_disk(md
)->part0
, ios
[rw
]);
1472 part_stat_add(cpu
, &dm_disk(md
)->part0
, sectors
[rw
], bio_sectors(bio
));
1475 /* if we're suspended, we have to queue this io for later */
1476 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))) {
1477 dm_put_live_table(md
, srcu_idx
);
1479 if (bio_rw(bio
) != READA
)
1486 __split_and_process_bio(md
, map
, bio
);
1487 dm_put_live_table(md
, srcu_idx
);
1491 int dm_request_based(struct mapped_device
*md
)
1493 return blk_queue_stackable(md
->queue
);
1496 static void dm_request(struct request_queue
*q
, struct bio
*bio
)
1498 struct mapped_device
*md
= q
->queuedata
;
1500 if (dm_request_based(md
))
1501 blk_queue_bio(q
, bio
);
1503 _dm_request(q
, bio
);
1506 void dm_dispatch_request(struct request
*rq
)
1510 if (blk_queue_io_stat(rq
->q
))
1511 rq
->cmd_flags
|= REQ_IO_STAT
;
1513 rq
->start_time
= jiffies
;
1514 r
= blk_insert_cloned_request(rq
->q
, rq
);
1516 dm_complete_request(rq
, r
);
1518 EXPORT_SYMBOL_GPL(dm_dispatch_request
);
1520 static int dm_rq_bio_constructor(struct bio
*bio
, struct bio
*bio_orig
,
1523 struct dm_rq_target_io
*tio
= data
;
1524 struct dm_rq_clone_bio_info
*info
=
1525 container_of(bio
, struct dm_rq_clone_bio_info
, clone
);
1527 info
->orig
= bio_orig
;
1529 bio
->bi_end_io
= end_clone_bio
;
1534 static int setup_clone(struct request
*clone
, struct request
*rq
,
1535 struct dm_rq_target_io
*tio
)
1539 r
= blk_rq_prep_clone(clone
, rq
, tio
->md
->bs
, GFP_ATOMIC
,
1540 dm_rq_bio_constructor
, tio
);
1544 clone
->cmd
= rq
->cmd
;
1545 clone
->cmd_len
= rq
->cmd_len
;
1546 clone
->sense
= rq
->sense
;
1547 clone
->end_io
= end_clone_request
;
1548 clone
->end_io_data
= tio
;
1553 static struct request
*clone_rq(struct request
*rq
, struct mapped_device
*md
,
1556 struct request
*clone
;
1557 struct dm_rq_target_io
*tio
;
1559 tio
= alloc_rq_tio(md
, gfp_mask
);
1567 memset(&tio
->info
, 0, sizeof(tio
->info
));
1569 clone
= &tio
->clone
;
1570 if (setup_clone(clone
, rq
, tio
)) {
1580 * Called with the queue lock held.
1582 static int dm_prep_fn(struct request_queue
*q
, struct request
*rq
)
1584 struct mapped_device
*md
= q
->queuedata
;
1585 struct request
*clone
;
1587 if (unlikely(rq
->special
)) {
1588 DMWARN("Already has something in rq->special.");
1589 return BLKPREP_KILL
;
1592 clone
= clone_rq(rq
, md
, GFP_ATOMIC
);
1594 return BLKPREP_DEFER
;
1596 rq
->special
= clone
;
1597 rq
->cmd_flags
|= REQ_DONTPREP
;
1604 * 0 : the request has been processed (not requeued)
1605 * !0 : the request has been requeued
1607 static int map_request(struct dm_target
*ti
, struct request
*clone
,
1608 struct mapped_device
*md
)
1610 int r
, requeued
= 0;
1611 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1614 r
= ti
->type
->map_rq(ti
, clone
, &tio
->info
);
1616 case DM_MAPIO_SUBMITTED
:
1617 /* The target has taken the I/O to submit by itself later */
1619 case DM_MAPIO_REMAPPED
:
1620 /* The target has remapped the I/O so dispatch it */
1621 trace_block_rq_remap(clone
->q
, clone
, disk_devt(dm_disk(md
)),
1622 blk_rq_pos(tio
->orig
));
1623 dm_dispatch_request(clone
);
1625 case DM_MAPIO_REQUEUE
:
1626 /* The target wants to requeue the I/O */
1627 dm_requeue_unmapped_request(clone
);
1632 DMWARN("unimplemented target map return value: %d", r
);
1636 /* The target wants to complete the I/O */
1637 dm_kill_unmapped_request(clone
, r
);
1644 static struct request
*dm_start_request(struct mapped_device
*md
, struct request
*orig
)
1646 struct request
*clone
;
1648 blk_start_request(orig
);
1649 clone
= orig
->special
;
1650 atomic_inc(&md
->pending
[rq_data_dir(clone
)]);
1653 * Hold the md reference here for the in-flight I/O.
1654 * We can't rely on the reference count by device opener,
1655 * because the device may be closed during the request completion
1656 * when all bios are completed.
1657 * See the comment in rq_completed() too.
1665 * q->request_fn for request-based dm.
1666 * Called with the queue lock held.
1668 static void dm_request_fn(struct request_queue
*q
)
1670 struct mapped_device
*md
= q
->queuedata
;
1672 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
1673 struct dm_target
*ti
;
1674 struct request
*rq
, *clone
;
1678 * For suspend, check blk_queue_stopped() and increment
1679 * ->pending within a single queue_lock not to increment the
1680 * number of in-flight I/Os after the queue is stopped in
1683 while (!blk_queue_stopped(q
)) {
1684 rq
= blk_peek_request(q
);
1688 /* always use block 0 to find the target for flushes for now */
1690 if (!(rq
->cmd_flags
& REQ_FLUSH
))
1691 pos
= blk_rq_pos(rq
);
1693 ti
= dm_table_find_target(map
, pos
);
1694 if (!dm_target_is_valid(ti
)) {
1696 * Must perform setup, that dm_done() requires,
1697 * before calling dm_kill_unmapped_request
1699 DMERR_LIMIT("request attempted access beyond the end of device");
1700 clone
= dm_start_request(md
, rq
);
1701 dm_kill_unmapped_request(clone
, -EIO
);
1705 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
1708 clone
= dm_start_request(md
, rq
);
1710 spin_unlock(q
->queue_lock
);
1711 if (map_request(ti
, clone
, md
))
1714 BUG_ON(!irqs_disabled());
1715 spin_lock(q
->queue_lock
);
1721 BUG_ON(!irqs_disabled());
1722 spin_lock(q
->queue_lock
);
1725 blk_delay_queue(q
, HZ
/ 10);
1727 dm_put_live_table(md
, srcu_idx
);
1730 int dm_underlying_device_busy(struct request_queue
*q
)
1732 return blk_lld_busy(q
);
1734 EXPORT_SYMBOL_GPL(dm_underlying_device_busy
);
1736 static int dm_lld_busy(struct request_queue
*q
)
1739 struct mapped_device
*md
= q
->queuedata
;
1740 struct dm_table
*map
= dm_get_live_table_fast(md
);
1742 if (!map
|| test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))
1745 r
= dm_table_any_busy_target(map
);
1747 dm_put_live_table_fast(md
);
1752 static int dm_any_congested(void *congested_data
, int bdi_bits
)
1755 struct mapped_device
*md
= congested_data
;
1756 struct dm_table
*map
;
1758 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
1759 map
= dm_get_live_table_fast(md
);
1762 * Request-based dm cares about only own queue for
1763 * the query about congestion status of request_queue
1765 if (dm_request_based(md
))
1766 r
= md
->queue
->backing_dev_info
.state
&
1769 r
= dm_table_any_congested(map
, bdi_bits
);
1771 dm_put_live_table_fast(md
);
1777 /*-----------------------------------------------------------------
1778 * An IDR is used to keep track of allocated minor numbers.
1779 *---------------------------------------------------------------*/
1780 static void free_minor(int minor
)
1782 spin_lock(&_minor_lock
);
1783 idr_remove(&_minor_idr
, minor
);
1784 spin_unlock(&_minor_lock
);
1788 * See if the device with a specific minor # is free.
1790 static int specific_minor(int minor
)
1794 if (minor
>= (1 << MINORBITS
))
1797 idr_preload(GFP_KERNEL
);
1798 spin_lock(&_minor_lock
);
1800 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, minor
, minor
+ 1, GFP_NOWAIT
);
1802 spin_unlock(&_minor_lock
);
1805 return r
== -ENOSPC
? -EBUSY
: r
;
1809 static int next_free_minor(int *minor
)
1813 idr_preload(GFP_KERNEL
);
1814 spin_lock(&_minor_lock
);
1816 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, 0, 1 << MINORBITS
, GFP_NOWAIT
);
1818 spin_unlock(&_minor_lock
);
1826 static const struct block_device_operations dm_blk_dops
;
1828 static void dm_wq_work(struct work_struct
*work
);
1830 static void dm_init_md_queue(struct mapped_device
*md
)
1833 * Request-based dm devices cannot be stacked on top of bio-based dm
1834 * devices. The type of this dm device has not been decided yet.
1835 * The type is decided at the first table loading time.
1836 * To prevent problematic device stacking, clear the queue flag
1837 * for request stacking support until then.
1839 * This queue is new, so no concurrency on the queue_flags.
1841 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE
, md
->queue
);
1843 md
->queue
->queuedata
= md
;
1844 md
->queue
->backing_dev_info
.congested_fn
= dm_any_congested
;
1845 md
->queue
->backing_dev_info
.congested_data
= md
;
1846 blk_queue_make_request(md
->queue
, dm_request
);
1847 blk_queue_bounce_limit(md
->queue
, BLK_BOUNCE_ANY
);
1848 blk_queue_merge_bvec(md
->queue
, dm_merge_bvec
);
1852 * Allocate and initialise a blank device with a given minor.
1854 static struct mapped_device
*alloc_dev(int minor
)
1857 struct mapped_device
*md
= kzalloc(sizeof(*md
), GFP_KERNEL
);
1861 DMWARN("unable to allocate device, out of memory.");
1865 if (!try_module_get(THIS_MODULE
))
1866 goto bad_module_get
;
1868 /* get a minor number for the dev */
1869 if (minor
== DM_ANY_MINOR
)
1870 r
= next_free_minor(&minor
);
1872 r
= specific_minor(minor
);
1876 r
= init_srcu_struct(&md
->io_barrier
);
1878 goto bad_io_barrier
;
1880 md
->type
= DM_TYPE_NONE
;
1881 mutex_init(&md
->suspend_lock
);
1882 mutex_init(&md
->type_lock
);
1883 spin_lock_init(&md
->deferred_lock
);
1884 atomic_set(&md
->holders
, 1);
1885 atomic_set(&md
->open_count
, 0);
1886 atomic_set(&md
->event_nr
, 0);
1887 atomic_set(&md
->uevent_seq
, 0);
1888 INIT_LIST_HEAD(&md
->uevent_list
);
1889 spin_lock_init(&md
->uevent_lock
);
1891 md
->queue
= blk_alloc_queue(GFP_KERNEL
);
1895 dm_init_md_queue(md
);
1897 md
->disk
= alloc_disk(1);
1901 atomic_set(&md
->pending
[0], 0);
1902 atomic_set(&md
->pending
[1], 0);
1903 init_waitqueue_head(&md
->wait
);
1904 INIT_WORK(&md
->work
, dm_wq_work
);
1905 init_waitqueue_head(&md
->eventq
);
1906 init_completion(&md
->kobj_holder
.completion
);
1908 md
->disk
->major
= _major
;
1909 md
->disk
->first_minor
= minor
;
1910 md
->disk
->fops
= &dm_blk_dops
;
1911 md
->disk
->queue
= md
->queue
;
1912 md
->disk
->private_data
= md
;
1913 sprintf(md
->disk
->disk_name
, "dm-%d", minor
);
1915 format_dev_t(md
->name
, MKDEV(_major
, minor
));
1917 md
->wq
= alloc_workqueue("kdmflush", WQ_MEM_RECLAIM
, 0);
1921 md
->bdev
= bdget_disk(md
->disk
, 0);
1925 bio_init(&md
->flush_bio
);
1926 md
->flush_bio
.bi_bdev
= md
->bdev
;
1927 md
->flush_bio
.bi_rw
= WRITE_FLUSH
;
1929 dm_stats_init(&md
->stats
);
1931 /* Populate the mapping, nobody knows we exist yet */
1932 spin_lock(&_minor_lock
);
1933 old_md
= idr_replace(&_minor_idr
, md
, minor
);
1934 spin_unlock(&_minor_lock
);
1936 BUG_ON(old_md
!= MINOR_ALLOCED
);
1941 destroy_workqueue(md
->wq
);
1943 del_gendisk(md
->disk
);
1946 blk_cleanup_queue(md
->queue
);
1948 cleanup_srcu_struct(&md
->io_barrier
);
1952 module_put(THIS_MODULE
);
1958 static void unlock_fs(struct mapped_device
*md
);
1960 static void free_dev(struct mapped_device
*md
)
1962 int minor
= MINOR(disk_devt(md
->disk
));
1966 destroy_workqueue(md
->wq
);
1968 mempool_destroy(md
->io_pool
);
1970 bioset_free(md
->bs
);
1971 blk_integrity_unregister(md
->disk
);
1972 del_gendisk(md
->disk
);
1973 cleanup_srcu_struct(&md
->io_barrier
);
1976 spin_lock(&_minor_lock
);
1977 md
->disk
->private_data
= NULL
;
1978 spin_unlock(&_minor_lock
);
1981 blk_cleanup_queue(md
->queue
);
1982 dm_stats_cleanup(&md
->stats
);
1983 module_put(THIS_MODULE
);
1987 static void __bind_mempools(struct mapped_device
*md
, struct dm_table
*t
)
1989 struct dm_md_mempools
*p
= dm_table_get_md_mempools(t
);
1991 if (md
->io_pool
&& md
->bs
) {
1992 /* The md already has necessary mempools. */
1993 if (dm_table_get_type(t
) == DM_TYPE_BIO_BASED
) {
1995 * Reload bioset because front_pad may have changed
1996 * because a different table was loaded.
1998 bioset_free(md
->bs
);
2001 } else if (dm_table_get_type(t
) == DM_TYPE_REQUEST_BASED
) {
2003 * There's no need to reload with request-based dm
2004 * because the size of front_pad doesn't change.
2005 * Note for future: If you are to reload bioset,
2006 * prep-ed requests in the queue may refer
2007 * to bio from the old bioset, so you must walk
2008 * through the queue to unprep.
2014 BUG_ON(!p
|| md
->io_pool
|| md
->bs
);
2016 md
->io_pool
= p
->io_pool
;
2022 /* mempool bind completed, now no need any mempools in the table */
2023 dm_table_free_md_mempools(t
);
2027 * Bind a table to the device.
2029 static void event_callback(void *context
)
2031 unsigned long flags
;
2033 struct mapped_device
*md
= (struct mapped_device
*) context
;
2035 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2036 list_splice_init(&md
->uevent_list
, &uevents
);
2037 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2039 dm_send_uevents(&uevents
, &disk_to_dev(md
->disk
)->kobj
);
2041 atomic_inc(&md
->event_nr
);
2042 wake_up(&md
->eventq
);
2046 * Protected by md->suspend_lock obtained by dm_swap_table().
2048 static void __set_size(struct mapped_device
*md
, sector_t size
)
2050 set_capacity(md
->disk
, size
);
2052 i_size_write(md
->bdev
->bd_inode
, (loff_t
)size
<< SECTOR_SHIFT
);
2056 * Return 1 if the queue has a compulsory merge_bvec_fn function.
2058 * If this function returns 0, then the device is either a non-dm
2059 * device without a merge_bvec_fn, or it is a dm device that is
2060 * able to split any bios it receives that are too big.
2062 int dm_queue_merge_is_compulsory(struct request_queue
*q
)
2064 struct mapped_device
*dev_md
;
2066 if (!q
->merge_bvec_fn
)
2069 if (q
->make_request_fn
== dm_request
) {
2070 dev_md
= q
->queuedata
;
2071 if (test_bit(DMF_MERGE_IS_OPTIONAL
, &dev_md
->flags
))
2078 static int dm_device_merge_is_compulsory(struct dm_target
*ti
,
2079 struct dm_dev
*dev
, sector_t start
,
2080 sector_t len
, void *data
)
2082 struct block_device
*bdev
= dev
->bdev
;
2083 struct request_queue
*q
= bdev_get_queue(bdev
);
2085 return dm_queue_merge_is_compulsory(q
);
2089 * Return 1 if it is acceptable to ignore merge_bvec_fn based
2090 * on the properties of the underlying devices.
2092 static int dm_table_merge_is_optional(struct dm_table
*table
)
2095 struct dm_target
*ti
;
2097 while (i
< dm_table_get_num_targets(table
)) {
2098 ti
= dm_table_get_target(table
, i
++);
2100 if (ti
->type
->iterate_devices
&&
2101 ti
->type
->iterate_devices(ti
, dm_device_merge_is_compulsory
, NULL
))
2109 * Returns old map, which caller must destroy.
2111 static struct dm_table
*__bind(struct mapped_device
*md
, struct dm_table
*t
,
2112 struct queue_limits
*limits
)
2114 struct dm_table
*old_map
;
2115 struct request_queue
*q
= md
->queue
;
2117 int merge_is_optional
;
2119 size
= dm_table_get_size(t
);
2122 * Wipe any geometry if the size of the table changed.
2124 if (size
!= dm_get_size(md
))
2125 memset(&md
->geometry
, 0, sizeof(md
->geometry
));
2127 __set_size(md
, size
);
2129 dm_table_event_callback(t
, event_callback
, md
);
2132 * The queue hasn't been stopped yet, if the old table type wasn't
2133 * for request-based during suspension. So stop it to prevent
2134 * I/O mapping before resume.
2135 * This must be done before setting the queue restrictions,
2136 * because request-based dm may be run just after the setting.
2138 if (dm_table_request_based(t
) && !blk_queue_stopped(q
))
2141 __bind_mempools(md
, t
);
2143 merge_is_optional
= dm_table_merge_is_optional(t
);
2146 rcu_assign_pointer(md
->map
, t
);
2147 md
->immutable_target_type
= dm_table_get_immutable_target_type(t
);
2149 dm_table_set_restrictions(t
, q
, limits
);
2150 if (merge_is_optional
)
2151 set_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2153 clear_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2160 * Returns unbound table for the caller to free.
2162 static struct dm_table
*__unbind(struct mapped_device
*md
)
2164 struct dm_table
*map
= md
->map
;
2169 dm_table_event_callback(map
, NULL
, NULL
);
2170 RCU_INIT_POINTER(md
->map
, NULL
);
2177 * Constructor for a new device.
2179 int dm_create(int minor
, struct mapped_device
**result
)
2181 struct mapped_device
*md
;
2183 md
= alloc_dev(minor
);
2194 * Functions to manage md->type.
2195 * All are required to hold md->type_lock.
2197 void dm_lock_md_type(struct mapped_device
*md
)
2199 mutex_lock(&md
->type_lock
);
2202 void dm_unlock_md_type(struct mapped_device
*md
)
2204 mutex_unlock(&md
->type_lock
);
2207 void dm_set_md_type(struct mapped_device
*md
, unsigned type
)
2209 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2213 unsigned dm_get_md_type(struct mapped_device
*md
)
2215 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2219 struct target_type
*dm_get_immutable_target_type(struct mapped_device
*md
)
2221 return md
->immutable_target_type
;
2225 * The queue_limits are only valid as long as you have a reference
2228 struct queue_limits
*dm_get_queue_limits(struct mapped_device
*md
)
2230 BUG_ON(!atomic_read(&md
->holders
));
2231 return &md
->queue
->limits
;
2233 EXPORT_SYMBOL_GPL(dm_get_queue_limits
);
2236 * Fully initialize a request-based queue (->elevator, ->request_fn, etc).
2238 static int dm_init_request_based_queue(struct mapped_device
*md
)
2240 struct request_queue
*q
= NULL
;
2242 if (md
->queue
->elevator
)
2245 /* Fully initialize the queue */
2246 q
= blk_init_allocated_queue(md
->queue
, dm_request_fn
, NULL
);
2251 dm_init_md_queue(md
);
2252 blk_queue_softirq_done(md
->queue
, dm_softirq_done
);
2253 blk_queue_prep_rq(md
->queue
, dm_prep_fn
);
2254 blk_queue_lld_busy(md
->queue
, dm_lld_busy
);
2256 elv_register_queue(md
->queue
);
2262 * Setup the DM device's queue based on md's type
2264 int dm_setup_md_queue(struct mapped_device
*md
)
2266 if ((dm_get_md_type(md
) == DM_TYPE_REQUEST_BASED
) &&
2267 !dm_init_request_based_queue(md
)) {
2268 DMWARN("Cannot initialize queue for request-based mapped device");
2275 static struct mapped_device
*dm_find_md(dev_t dev
)
2277 struct mapped_device
*md
;
2278 unsigned minor
= MINOR(dev
);
2280 if (MAJOR(dev
) != _major
|| minor
>= (1 << MINORBITS
))
2283 spin_lock(&_minor_lock
);
2285 md
= idr_find(&_minor_idr
, minor
);
2286 if (md
&& (md
== MINOR_ALLOCED
||
2287 (MINOR(disk_devt(dm_disk(md
))) != minor
) ||
2288 dm_deleting_md(md
) ||
2289 test_bit(DMF_FREEING
, &md
->flags
))) {
2295 spin_unlock(&_minor_lock
);
2300 struct mapped_device
*dm_get_md(dev_t dev
)
2302 struct mapped_device
*md
= dm_find_md(dev
);
2309 EXPORT_SYMBOL_GPL(dm_get_md
);
2311 void *dm_get_mdptr(struct mapped_device
*md
)
2313 return md
->interface_ptr
;
2316 void dm_set_mdptr(struct mapped_device
*md
, void *ptr
)
2318 md
->interface_ptr
= ptr
;
2321 void dm_get(struct mapped_device
*md
)
2323 atomic_inc(&md
->holders
);
2324 BUG_ON(test_bit(DMF_FREEING
, &md
->flags
));
2327 const char *dm_device_name(struct mapped_device
*md
)
2331 EXPORT_SYMBOL_GPL(dm_device_name
);
2333 static void __dm_destroy(struct mapped_device
*md
, bool wait
)
2335 struct dm_table
*map
;
2340 spin_lock(&_minor_lock
);
2341 map
= dm_get_live_table(md
, &srcu_idx
);
2342 idr_replace(&_minor_idr
, MINOR_ALLOCED
, MINOR(disk_devt(dm_disk(md
))));
2343 set_bit(DMF_FREEING
, &md
->flags
);
2344 spin_unlock(&_minor_lock
);
2346 if (!dm_suspended_md(md
)) {
2347 dm_table_presuspend_targets(map
);
2348 dm_table_postsuspend_targets(map
);
2351 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2352 dm_put_live_table(md
, srcu_idx
);
2355 * Rare, but there may be I/O requests still going to complete,
2356 * for example. Wait for all references to disappear.
2357 * No one should increment the reference count of the mapped_device,
2358 * after the mapped_device state becomes DMF_FREEING.
2361 while (atomic_read(&md
->holders
))
2363 else if (atomic_read(&md
->holders
))
2364 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2365 dm_device_name(md
), atomic_read(&md
->holders
));
2368 dm_table_destroy(__unbind(md
));
2372 void dm_destroy(struct mapped_device
*md
)
2374 __dm_destroy(md
, true);
2377 void dm_destroy_immediate(struct mapped_device
*md
)
2379 __dm_destroy(md
, false);
2382 void dm_put(struct mapped_device
*md
)
2384 atomic_dec(&md
->holders
);
2386 EXPORT_SYMBOL_GPL(dm_put
);
2388 static int dm_wait_for_completion(struct mapped_device
*md
, int interruptible
)
2391 DECLARE_WAITQUEUE(wait
, current
);
2393 add_wait_queue(&md
->wait
, &wait
);
2396 set_current_state(interruptible
);
2398 if (!md_in_flight(md
))
2401 if (interruptible
== TASK_INTERRUPTIBLE
&&
2402 signal_pending(current
)) {
2409 set_current_state(TASK_RUNNING
);
2411 remove_wait_queue(&md
->wait
, &wait
);
2417 * Process the deferred bios
2419 static void dm_wq_work(struct work_struct
*work
)
2421 struct mapped_device
*md
= container_of(work
, struct mapped_device
,
2425 struct dm_table
*map
;
2427 map
= dm_get_live_table(md
, &srcu_idx
);
2429 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
2430 spin_lock_irq(&md
->deferred_lock
);
2431 c
= bio_list_pop(&md
->deferred
);
2432 spin_unlock_irq(&md
->deferred_lock
);
2437 if (dm_request_based(md
))
2438 generic_make_request(c
);
2440 __split_and_process_bio(md
, map
, c
);
2443 dm_put_live_table(md
, srcu_idx
);
2446 static void dm_queue_flush(struct mapped_device
*md
)
2448 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2449 smp_mb__after_atomic();
2450 queue_work(md
->wq
, &md
->work
);
2454 * Swap in a new table, returning the old one for the caller to destroy.
2456 struct dm_table
*dm_swap_table(struct mapped_device
*md
, struct dm_table
*table
)
2458 struct dm_table
*live_map
= NULL
, *map
= ERR_PTR(-EINVAL
);
2459 struct queue_limits limits
;
2462 mutex_lock(&md
->suspend_lock
);
2464 /* device must be suspended */
2465 if (!dm_suspended_md(md
))
2469 * If the new table has no data devices, retain the existing limits.
2470 * This helps multipath with queue_if_no_path if all paths disappear,
2471 * then new I/O is queued based on these limits, and then some paths
2474 if (dm_table_has_no_data_devices(table
)) {
2475 live_map
= dm_get_live_table_fast(md
);
2477 limits
= md
->queue
->limits
;
2478 dm_put_live_table_fast(md
);
2482 r
= dm_calculate_queue_limits(table
, &limits
);
2489 map
= __bind(md
, table
, &limits
);
2492 mutex_unlock(&md
->suspend_lock
);
2497 * Functions to lock and unlock any filesystem running on the
2500 static int lock_fs(struct mapped_device
*md
)
2504 WARN_ON(md
->frozen_sb
);
2506 md
->frozen_sb
= freeze_bdev(md
->bdev
);
2507 if (IS_ERR(md
->frozen_sb
)) {
2508 r
= PTR_ERR(md
->frozen_sb
);
2509 md
->frozen_sb
= NULL
;
2513 set_bit(DMF_FROZEN
, &md
->flags
);
2518 static void unlock_fs(struct mapped_device
*md
)
2520 if (!test_bit(DMF_FROZEN
, &md
->flags
))
2523 thaw_bdev(md
->bdev
, md
->frozen_sb
);
2524 md
->frozen_sb
= NULL
;
2525 clear_bit(DMF_FROZEN
, &md
->flags
);
2529 * We need to be able to change a mapping table under a mounted
2530 * filesystem. For example we might want to move some data in
2531 * the background. Before the table can be swapped with
2532 * dm_bind_table, dm_suspend must be called to flush any in
2533 * flight bios and ensure that any further io gets deferred.
2536 * Suspend mechanism in request-based dm.
2538 * 1. Flush all I/Os by lock_fs() if needed.
2539 * 2. Stop dispatching any I/O by stopping the request_queue.
2540 * 3. Wait for all in-flight I/Os to be completed or requeued.
2542 * To abort suspend, start the request_queue.
2544 int dm_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
2546 struct dm_table
*map
= NULL
;
2548 int do_lockfs
= suspend_flags
& DM_SUSPEND_LOCKFS_FLAG
? 1 : 0;
2549 int noflush
= suspend_flags
& DM_SUSPEND_NOFLUSH_FLAG
? 1 : 0;
2551 mutex_lock(&md
->suspend_lock
);
2553 if (dm_suspended_md(md
)) {
2561 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2562 * This flag is cleared before dm_suspend returns.
2565 set_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2567 /* This does not get reverted if there's an error later. */
2568 dm_table_presuspend_targets(map
);
2571 * Flush I/O to the device.
2572 * Any I/O submitted after lock_fs() may not be flushed.
2573 * noflush takes precedence over do_lockfs.
2574 * (lock_fs() flushes I/Os and waits for them to complete.)
2576 if (!noflush
&& do_lockfs
) {
2583 * Here we must make sure that no processes are submitting requests
2584 * to target drivers i.e. no one may be executing
2585 * __split_and_process_bio. This is called from dm_request and
2588 * To get all processes out of __split_and_process_bio in dm_request,
2589 * we take the write lock. To prevent any process from reentering
2590 * __split_and_process_bio from dm_request and quiesce the thread
2591 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2592 * flush_workqueue(md->wq).
2594 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2595 synchronize_srcu(&md
->io_barrier
);
2598 * Stop md->queue before flushing md->wq in case request-based
2599 * dm defers requests to md->wq from md->queue.
2601 if (dm_request_based(md
))
2602 stop_queue(md
->queue
);
2604 flush_workqueue(md
->wq
);
2607 * At this point no more requests are entering target request routines.
2608 * We call dm_wait_for_completion to wait for all existing requests
2611 r
= dm_wait_for_completion(md
, TASK_INTERRUPTIBLE
);
2614 clear_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2615 synchronize_srcu(&md
->io_barrier
);
2617 /* were we interrupted ? */
2621 if (dm_request_based(md
))
2622 start_queue(md
->queue
);
2625 goto out_unlock
; /* pushback list is already flushed, so skip flush */
2629 * If dm_wait_for_completion returned 0, the device is completely
2630 * quiescent now. There is no request-processing activity. All new
2631 * requests are being added to md->deferred list.
2634 set_bit(DMF_SUSPENDED
, &md
->flags
);
2636 dm_table_postsuspend_targets(map
);
2639 mutex_unlock(&md
->suspend_lock
);
2643 int dm_resume(struct mapped_device
*md
)
2646 struct dm_table
*map
= NULL
;
2648 mutex_lock(&md
->suspend_lock
);
2649 if (!dm_suspended_md(md
))
2653 if (!map
|| !dm_table_get_size(map
))
2656 r
= dm_table_resume_targets(map
);
2663 * Flushing deferred I/Os must be done after targets are resumed
2664 * so that mapping of targets can work correctly.
2665 * Request-based dm is queueing the deferred I/Os in its request_queue.
2667 if (dm_request_based(md
))
2668 start_queue(md
->queue
);
2672 clear_bit(DMF_SUSPENDED
, &md
->flags
);
2676 mutex_unlock(&md
->suspend_lock
);
2682 * Internal suspend/resume works like userspace-driven suspend. It waits
2683 * until all bios finish and prevents issuing new bios to the target drivers.
2684 * It may be used only from the kernel.
2686 * Internal suspend holds md->suspend_lock, which prevents interaction with
2687 * userspace-driven suspend.
2690 void dm_internal_suspend(struct mapped_device
*md
)
2692 mutex_lock(&md
->suspend_lock
);
2693 if (dm_suspended_md(md
))
2696 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2697 synchronize_srcu(&md
->io_barrier
);
2698 flush_workqueue(md
->wq
);
2699 dm_wait_for_completion(md
, TASK_UNINTERRUPTIBLE
);
2702 void dm_internal_resume(struct mapped_device
*md
)
2704 if (dm_suspended_md(md
))
2710 mutex_unlock(&md
->suspend_lock
);
2713 /*-----------------------------------------------------------------
2714 * Event notification.
2715 *---------------------------------------------------------------*/
2716 int dm_kobject_uevent(struct mapped_device
*md
, enum kobject_action action
,
2719 char udev_cookie
[DM_COOKIE_LENGTH
];
2720 char *envp
[] = { udev_cookie
, NULL
};
2723 return kobject_uevent(&disk_to_dev(md
->disk
)->kobj
, action
);
2725 snprintf(udev_cookie
, DM_COOKIE_LENGTH
, "%s=%u",
2726 DM_COOKIE_ENV_VAR_NAME
, cookie
);
2727 return kobject_uevent_env(&disk_to_dev(md
->disk
)->kobj
,
2732 uint32_t dm_next_uevent_seq(struct mapped_device
*md
)
2734 return atomic_add_return(1, &md
->uevent_seq
);
2737 uint32_t dm_get_event_nr(struct mapped_device
*md
)
2739 return atomic_read(&md
->event_nr
);
2742 int dm_wait_event(struct mapped_device
*md
, int event_nr
)
2744 return wait_event_interruptible(md
->eventq
,
2745 (event_nr
!= atomic_read(&md
->event_nr
)));
2748 void dm_uevent_add(struct mapped_device
*md
, struct list_head
*elist
)
2750 unsigned long flags
;
2752 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2753 list_add(elist
, &md
->uevent_list
);
2754 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2758 * The gendisk is only valid as long as you have a reference
2761 struct gendisk
*dm_disk(struct mapped_device
*md
)
2766 struct kobject
*dm_kobject(struct mapped_device
*md
)
2768 return &md
->kobj_holder
.kobj
;
2771 struct mapped_device
*dm_get_from_kobject(struct kobject
*kobj
)
2773 struct mapped_device
*md
;
2775 md
= container_of(kobj
, struct mapped_device
, kobj_holder
.kobj
);
2777 if (test_bit(DMF_FREEING
, &md
->flags
) ||
2785 int dm_suspended_md(struct mapped_device
*md
)
2787 return test_bit(DMF_SUSPENDED
, &md
->flags
);
2790 int dm_test_deferred_remove_flag(struct mapped_device
*md
)
2792 return test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
2795 int dm_suspended(struct dm_target
*ti
)
2797 return dm_suspended_md(dm_table_get_md(ti
->table
));
2799 EXPORT_SYMBOL_GPL(dm_suspended
);
2801 int dm_noflush_suspending(struct dm_target
*ti
)
2803 return __noflush_suspending(dm_table_get_md(ti
->table
));
2805 EXPORT_SYMBOL_GPL(dm_noflush_suspending
);
2807 struct dm_md_mempools
*dm_alloc_md_mempools(unsigned type
, unsigned integrity
, unsigned per_bio_data_size
)
2809 struct dm_md_mempools
*pools
= kzalloc(sizeof(*pools
), GFP_KERNEL
);
2810 struct kmem_cache
*cachep
;
2811 unsigned int pool_size
;
2812 unsigned int front_pad
;
2817 if (type
== DM_TYPE_BIO_BASED
) {
2819 pool_size
= dm_get_reserved_bio_based_ios();
2820 front_pad
= roundup(per_bio_data_size
, __alignof__(struct dm_target_io
)) + offsetof(struct dm_target_io
, clone
);
2821 } else if (type
== DM_TYPE_REQUEST_BASED
) {
2822 cachep
= _rq_tio_cache
;
2823 pool_size
= dm_get_reserved_rq_based_ios();
2824 front_pad
= offsetof(struct dm_rq_clone_bio_info
, clone
);
2825 /* per_bio_data_size is not used. See __bind_mempools(). */
2826 WARN_ON(per_bio_data_size
!= 0);
2830 pools
->io_pool
= mempool_create_slab_pool(pool_size
, cachep
);
2831 if (!pools
->io_pool
)
2834 pools
->bs
= bioset_create(pool_size
, front_pad
);
2838 if (integrity
&& bioset_integrity_create(pools
->bs
, pool_size
))
2844 dm_free_md_mempools(pools
);
2849 void dm_free_md_mempools(struct dm_md_mempools
*pools
)
2855 mempool_destroy(pools
->io_pool
);
2858 bioset_free(pools
->bs
);
2863 static const struct block_device_operations dm_blk_dops
= {
2864 .open
= dm_blk_open
,
2865 .release
= dm_blk_close
,
2866 .ioctl
= dm_blk_ioctl
,
2867 .getgeo
= dm_blk_getgeo
,
2868 .owner
= THIS_MODULE
2874 module_init(dm_init
);
2875 module_exit(dm_exit
);
2877 module_param(major
, uint
, 0);
2878 MODULE_PARM_DESC(major
, "The major number of the device mapper");
2880 module_param(reserved_bio_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
2881 MODULE_PARM_DESC(reserved_bio_based_ios
, "Reserved IOs in bio-based mempools");
2883 module_param(reserved_rq_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
2884 MODULE_PARM_DESC(reserved_rq_based_ios
, "Reserved IOs in request-based mempools");
2886 MODULE_DESCRIPTION(DM_NAME
" driver");
2887 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
2888 MODULE_LICENSE("GPL");