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>
22 #include <linux/wait.h>
23 #include <linux/kthread.h>
24 #include <linux/ktime.h>
25 #include <linux/elevator.h> /* for rq_end_sector() */
26 #include <linux/blk-mq.h>
28 #include <trace/events/block.h>
30 #define DM_MSG_PREFIX "core"
34 * ratelimit state to be used in DMXXX_LIMIT().
36 DEFINE_RATELIMIT_STATE(dm_ratelimit_state
,
37 DEFAULT_RATELIMIT_INTERVAL
,
38 DEFAULT_RATELIMIT_BURST
);
39 EXPORT_SYMBOL(dm_ratelimit_state
);
43 * Cookies are numeric values sent with CHANGE and REMOVE
44 * uevents while resuming, removing or renaming the device.
46 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
47 #define DM_COOKIE_LENGTH 24
49 static const char *_name
= DM_NAME
;
51 static unsigned int major
= 0;
52 static unsigned int _major
= 0;
54 static DEFINE_IDR(_minor_idr
);
56 static DEFINE_SPINLOCK(_minor_lock
);
58 static void do_deferred_remove(struct work_struct
*w
);
60 static DECLARE_WORK(deferred_remove_work
, do_deferred_remove
);
62 static struct workqueue_struct
*deferred_remove_workqueue
;
66 * One of these is allocated per bio.
69 struct mapped_device
*md
;
73 unsigned long start_time
;
74 spinlock_t endio_lock
;
75 struct dm_stats_aux stats_aux
;
79 * For request-based dm.
80 * One of these is allocated per request.
82 struct dm_rq_target_io
{
83 struct mapped_device
*md
;
85 struct request
*orig
, *clone
;
86 struct kthread_work work
;
89 struct dm_stats_aux stats_aux
;
90 unsigned long duration_jiffies
;
95 * For request-based dm - the bio clones we allocate are embedded in these
98 * We allocate these with bio_alloc_bioset, using the front_pad parameter when
99 * the bioset is created - this means the bio has to come at the end of the
102 struct dm_rq_clone_bio_info
{
104 struct dm_rq_target_io
*tio
;
108 union map_info
*dm_get_rq_mapinfo(struct request
*rq
)
110 if (rq
&& rq
->end_io_data
)
111 return &((struct dm_rq_target_io
*)rq
->end_io_data
)->info
;
114 EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo
);
116 #define MINOR_ALLOCED ((void *)-1)
119 * Bits for the md->flags field.
121 #define DMF_BLOCK_IO_FOR_SUSPEND 0
122 #define DMF_SUSPENDED 1
124 #define DMF_FREEING 3
125 #define DMF_DELETING 4
126 #define DMF_NOFLUSH_SUSPENDING 5
127 #define DMF_DEFERRED_REMOVE 6
128 #define DMF_SUSPENDED_INTERNALLY 7
131 * A dummy definition to make RCU happy.
132 * struct dm_table should never be dereferenced in this file.
139 * Work processed by per-device workqueue.
141 struct mapped_device
{
142 struct srcu_struct io_barrier
;
143 struct mutex suspend_lock
;
148 * The current mapping.
149 * Use dm_get_live_table{_fast} or take suspend_lock for
152 struct dm_table __rcu
*map
;
154 struct list_head table_devices
;
155 struct mutex table_devices_lock
;
159 struct request_queue
*queue
;
161 /* Protect queue and type against concurrent access. */
162 struct mutex type_lock
;
164 struct target_type
*immutable_target_type
;
166 struct gendisk
*disk
;
172 * A list of ios that arrived while we were suspended.
175 wait_queue_head_t wait
;
176 struct work_struct work
;
177 struct bio_list deferred
;
178 spinlock_t deferred_lock
;
181 * Processing queue (flush)
183 struct workqueue_struct
*wq
;
186 * io objects are allocated from here.
197 wait_queue_head_t eventq
;
199 struct list_head uevent_list
;
200 spinlock_t uevent_lock
; /* Protect access to uevent_list */
203 * freeze/thaw support require holding onto a super block
205 struct super_block
*frozen_sb
;
206 struct block_device
*bdev
;
208 /* forced geometry settings */
209 struct hd_geometry geometry
;
211 /* kobject and completion */
212 struct dm_kobject_holder kobj_holder
;
214 /* zero-length flush that will be cloned and submitted to targets */
215 struct bio flush_bio
;
217 /* the number of internal suspends */
218 unsigned internal_suspend_count
;
220 struct dm_stats stats
;
222 struct kthread_worker kworker
;
223 struct task_struct
*kworker_task
;
225 /* for request-based merge heuristic in dm_request_fn() */
226 unsigned seq_rq_merge_deadline_usecs
;
228 sector_t last_rq_pos
;
229 ktime_t last_rq_start_time
;
231 /* for blk-mq request-based DM support */
232 struct blk_mq_tag_set tag_set
;
236 #ifdef CONFIG_DM_MQ_DEFAULT
237 static bool use_blk_mq
= true;
239 static bool use_blk_mq
= false;
242 bool dm_use_blk_mq(struct mapped_device
*md
)
244 return md
->use_blk_mq
;
248 * For mempools pre-allocation at the table loading time.
250 struct dm_md_mempools
{
256 struct table_device
{
257 struct list_head list
;
259 struct dm_dev dm_dev
;
262 #define RESERVED_BIO_BASED_IOS 16
263 #define RESERVED_REQUEST_BASED_IOS 256
264 #define RESERVED_MAX_IOS 1024
265 static struct kmem_cache
*_io_cache
;
266 static struct kmem_cache
*_rq_tio_cache
;
267 static struct kmem_cache
*_rq_cache
;
270 * Bio-based DM's mempools' reserved IOs set by the user.
272 static unsigned reserved_bio_based_ios
= RESERVED_BIO_BASED_IOS
;
275 * Request-based DM's mempools' reserved IOs set by the user.
277 static unsigned reserved_rq_based_ios
= RESERVED_REQUEST_BASED_IOS
;
279 static unsigned __dm_get_module_param(unsigned *module_param
,
280 unsigned def
, unsigned max
)
282 unsigned param
= ACCESS_ONCE(*module_param
);
283 unsigned modified_param
= 0;
286 modified_param
= def
;
287 else if (param
> max
)
288 modified_param
= max
;
290 if (modified_param
) {
291 (void)cmpxchg(module_param
, param
, modified_param
);
292 param
= modified_param
;
298 unsigned dm_get_reserved_bio_based_ios(void)
300 return __dm_get_module_param(&reserved_bio_based_ios
,
301 RESERVED_BIO_BASED_IOS
, RESERVED_MAX_IOS
);
303 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios
);
305 unsigned dm_get_reserved_rq_based_ios(void)
307 return __dm_get_module_param(&reserved_rq_based_ios
,
308 RESERVED_REQUEST_BASED_IOS
, RESERVED_MAX_IOS
);
310 EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios
);
312 static int __init
local_init(void)
316 /* allocate a slab for the dm_ios */
317 _io_cache
= KMEM_CACHE(dm_io
, 0);
321 _rq_tio_cache
= KMEM_CACHE(dm_rq_target_io
, 0);
323 goto out_free_io_cache
;
325 _rq_cache
= kmem_cache_create("dm_clone_request", sizeof(struct request
),
326 __alignof__(struct request
), 0, NULL
);
328 goto out_free_rq_tio_cache
;
330 r
= dm_uevent_init();
332 goto out_free_rq_cache
;
334 deferred_remove_workqueue
= alloc_workqueue("kdmremove", WQ_UNBOUND
, 1);
335 if (!deferred_remove_workqueue
) {
337 goto out_uevent_exit
;
341 r
= register_blkdev(_major
, _name
);
343 goto out_free_workqueue
;
351 destroy_workqueue(deferred_remove_workqueue
);
355 kmem_cache_destroy(_rq_cache
);
356 out_free_rq_tio_cache
:
357 kmem_cache_destroy(_rq_tio_cache
);
359 kmem_cache_destroy(_io_cache
);
364 static void local_exit(void)
366 flush_scheduled_work();
367 destroy_workqueue(deferred_remove_workqueue
);
369 kmem_cache_destroy(_rq_cache
);
370 kmem_cache_destroy(_rq_tio_cache
);
371 kmem_cache_destroy(_io_cache
);
372 unregister_blkdev(_major
, _name
);
377 DMINFO("cleaned up");
380 static int (*_inits
[])(void) __initdata
= {
391 static void (*_exits
[])(void) = {
402 static int __init
dm_init(void)
404 const int count
= ARRAY_SIZE(_inits
);
408 for (i
= 0; i
< count
; i
++) {
423 static void __exit
dm_exit(void)
425 int i
= ARRAY_SIZE(_exits
);
431 * Should be empty by this point.
433 idr_destroy(&_minor_idr
);
437 * Block device functions
439 int dm_deleting_md(struct mapped_device
*md
)
441 return test_bit(DMF_DELETING
, &md
->flags
);
444 static int dm_blk_open(struct block_device
*bdev
, fmode_t mode
)
446 struct mapped_device
*md
;
448 spin_lock(&_minor_lock
);
450 md
= bdev
->bd_disk
->private_data
;
454 if (test_bit(DMF_FREEING
, &md
->flags
) ||
455 dm_deleting_md(md
)) {
461 atomic_inc(&md
->open_count
);
463 spin_unlock(&_minor_lock
);
465 return md
? 0 : -ENXIO
;
468 static void dm_blk_close(struct gendisk
*disk
, fmode_t mode
)
470 struct mapped_device
*md
;
472 spin_lock(&_minor_lock
);
474 md
= disk
->private_data
;
478 if (atomic_dec_and_test(&md
->open_count
) &&
479 (test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
)))
480 queue_work(deferred_remove_workqueue
, &deferred_remove_work
);
484 spin_unlock(&_minor_lock
);
487 int dm_open_count(struct mapped_device
*md
)
489 return atomic_read(&md
->open_count
);
493 * Guarantees nothing is using the device before it's deleted.
495 int dm_lock_for_deletion(struct mapped_device
*md
, bool mark_deferred
, bool only_deferred
)
499 spin_lock(&_minor_lock
);
501 if (dm_open_count(md
)) {
504 set_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
505 } else if (only_deferred
&& !test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
))
508 set_bit(DMF_DELETING
, &md
->flags
);
510 spin_unlock(&_minor_lock
);
515 int dm_cancel_deferred_remove(struct mapped_device
*md
)
519 spin_lock(&_minor_lock
);
521 if (test_bit(DMF_DELETING
, &md
->flags
))
524 clear_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
526 spin_unlock(&_minor_lock
);
531 static void do_deferred_remove(struct work_struct
*w
)
533 dm_deferred_remove();
536 sector_t
dm_get_size(struct mapped_device
*md
)
538 return get_capacity(md
->disk
);
541 struct request_queue
*dm_get_md_queue(struct mapped_device
*md
)
546 struct dm_stats
*dm_get_stats(struct mapped_device
*md
)
551 static int dm_blk_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
553 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
555 return dm_get_geometry(md
, geo
);
558 static int dm_get_live_table_for_ioctl(struct mapped_device
*md
,
559 struct dm_target
**tgt
, struct block_device
**bdev
,
560 fmode_t
*mode
, int *srcu_idx
)
562 struct dm_table
*map
;
567 map
= dm_get_live_table(md
, srcu_idx
);
568 if (!map
|| !dm_table_get_size(map
))
571 /* We only support devices that have a single target */
572 if (dm_table_get_num_targets(map
) != 1)
575 *tgt
= dm_table_get_target(map
, 0);
577 if (!(*tgt
)->type
->prepare_ioctl
)
580 if (dm_suspended_md(md
)) {
585 r
= (*tgt
)->type
->prepare_ioctl(*tgt
, bdev
, mode
);
592 dm_put_live_table(md
, *srcu_idx
);
593 if (r
== -ENOTCONN
) {
600 static int dm_blk_ioctl(struct block_device
*bdev
, fmode_t mode
,
601 unsigned int cmd
, unsigned long arg
)
603 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
604 struct dm_target
*tgt
;
607 r
= dm_get_live_table_for_ioctl(md
, &tgt
, &bdev
, &mode
, &srcu_idx
);
613 * Target determined this ioctl is being issued against
614 * a logical partition of the parent bdev; so extra
615 * validation is needed.
617 r
= scsi_verify_blk_ioctl(NULL
, cmd
);
622 r
= __blkdev_driver_ioctl(bdev
, mode
, cmd
, arg
);
624 dm_put_live_table(md
, srcu_idx
);
628 static struct dm_io
*alloc_io(struct mapped_device
*md
)
630 return mempool_alloc(md
->io_pool
, GFP_NOIO
);
633 static void free_io(struct mapped_device
*md
, struct dm_io
*io
)
635 mempool_free(io
, md
->io_pool
);
638 static void free_tio(struct mapped_device
*md
, struct dm_target_io
*tio
)
640 bio_put(&tio
->clone
);
643 static struct dm_rq_target_io
*alloc_rq_tio(struct mapped_device
*md
,
646 return mempool_alloc(md
->io_pool
, gfp_mask
);
649 static void free_rq_tio(struct dm_rq_target_io
*tio
)
651 mempool_free(tio
, tio
->md
->io_pool
);
654 static struct request
*alloc_clone_request(struct mapped_device
*md
,
657 return mempool_alloc(md
->rq_pool
, gfp_mask
);
660 static void free_clone_request(struct mapped_device
*md
, struct request
*rq
)
662 mempool_free(rq
, md
->rq_pool
);
665 static int md_in_flight(struct mapped_device
*md
)
667 return atomic_read(&md
->pending
[READ
]) +
668 atomic_read(&md
->pending
[WRITE
]);
671 static void start_io_acct(struct dm_io
*io
)
673 struct mapped_device
*md
= io
->md
;
674 struct bio
*bio
= io
->bio
;
676 int rw
= bio_data_dir(bio
);
678 io
->start_time
= jiffies
;
680 cpu
= part_stat_lock();
681 part_round_stats(cpu
, &dm_disk(md
)->part0
);
683 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
],
684 atomic_inc_return(&md
->pending
[rw
]));
686 if (unlikely(dm_stats_used(&md
->stats
)))
687 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
688 bio_sectors(bio
), false, 0, &io
->stats_aux
);
691 static void end_io_acct(struct dm_io
*io
)
693 struct mapped_device
*md
= io
->md
;
694 struct bio
*bio
= io
->bio
;
695 unsigned long duration
= jiffies
- io
->start_time
;
697 int rw
= bio_data_dir(bio
);
699 generic_end_io_acct(rw
, &dm_disk(md
)->part0
, io
->start_time
);
701 if (unlikely(dm_stats_used(&md
->stats
)))
702 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
703 bio_sectors(bio
), true, duration
, &io
->stats_aux
);
706 * After this is decremented the bio must not be touched if it is
709 pending
= atomic_dec_return(&md
->pending
[rw
]);
710 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
], pending
);
711 pending
+= atomic_read(&md
->pending
[rw
^0x1]);
713 /* nudge anyone waiting on suspend queue */
719 * Add the bio to the list of deferred io.
721 static void queue_io(struct mapped_device
*md
, struct bio
*bio
)
725 spin_lock_irqsave(&md
->deferred_lock
, flags
);
726 bio_list_add(&md
->deferred
, bio
);
727 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
728 queue_work(md
->wq
, &md
->work
);
732 * Everyone (including functions in this file), should use this
733 * function to access the md->map field, and make sure they call
734 * dm_put_live_table() when finished.
736 struct dm_table
*dm_get_live_table(struct mapped_device
*md
, int *srcu_idx
) __acquires(md
->io_barrier
)
738 *srcu_idx
= srcu_read_lock(&md
->io_barrier
);
740 return srcu_dereference(md
->map
, &md
->io_barrier
);
743 void dm_put_live_table(struct mapped_device
*md
, int srcu_idx
) __releases(md
->io_barrier
)
745 srcu_read_unlock(&md
->io_barrier
, srcu_idx
);
748 void dm_sync_table(struct mapped_device
*md
)
750 synchronize_srcu(&md
->io_barrier
);
751 synchronize_rcu_expedited();
755 * A fast alternative to dm_get_live_table/dm_put_live_table.
756 * The caller must not block between these two functions.
758 static struct dm_table
*dm_get_live_table_fast(struct mapped_device
*md
) __acquires(RCU
)
761 return rcu_dereference(md
->map
);
764 static void dm_put_live_table_fast(struct mapped_device
*md
) __releases(RCU
)
770 * Open a table device so we can use it as a map destination.
772 static int open_table_device(struct table_device
*td
, dev_t dev
,
773 struct mapped_device
*md
)
775 static char *_claim_ptr
= "I belong to device-mapper";
776 struct block_device
*bdev
;
780 BUG_ON(td
->dm_dev
.bdev
);
782 bdev
= blkdev_get_by_dev(dev
, td
->dm_dev
.mode
| FMODE_EXCL
, _claim_ptr
);
784 return PTR_ERR(bdev
);
786 r
= bd_link_disk_holder(bdev
, dm_disk(md
));
788 blkdev_put(bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
792 td
->dm_dev
.bdev
= bdev
;
797 * Close a table device that we've been using.
799 static void close_table_device(struct table_device
*td
, struct mapped_device
*md
)
801 if (!td
->dm_dev
.bdev
)
804 bd_unlink_disk_holder(td
->dm_dev
.bdev
, dm_disk(md
));
805 blkdev_put(td
->dm_dev
.bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
806 td
->dm_dev
.bdev
= NULL
;
809 static struct table_device
*find_table_device(struct list_head
*l
, dev_t dev
,
811 struct table_device
*td
;
813 list_for_each_entry(td
, l
, list
)
814 if (td
->dm_dev
.bdev
->bd_dev
== dev
&& td
->dm_dev
.mode
== mode
)
820 int dm_get_table_device(struct mapped_device
*md
, dev_t dev
, fmode_t mode
,
821 struct dm_dev
**result
) {
823 struct table_device
*td
;
825 mutex_lock(&md
->table_devices_lock
);
826 td
= find_table_device(&md
->table_devices
, dev
, mode
);
828 td
= kmalloc(sizeof(*td
), GFP_KERNEL
);
830 mutex_unlock(&md
->table_devices_lock
);
834 td
->dm_dev
.mode
= mode
;
835 td
->dm_dev
.bdev
= NULL
;
837 if ((r
= open_table_device(td
, dev
, md
))) {
838 mutex_unlock(&md
->table_devices_lock
);
843 format_dev_t(td
->dm_dev
.name
, dev
);
845 atomic_set(&td
->count
, 0);
846 list_add(&td
->list
, &md
->table_devices
);
848 atomic_inc(&td
->count
);
849 mutex_unlock(&md
->table_devices_lock
);
851 *result
= &td
->dm_dev
;
854 EXPORT_SYMBOL_GPL(dm_get_table_device
);
856 void dm_put_table_device(struct mapped_device
*md
, struct dm_dev
*d
)
858 struct table_device
*td
= container_of(d
, struct table_device
, dm_dev
);
860 mutex_lock(&md
->table_devices_lock
);
861 if (atomic_dec_and_test(&td
->count
)) {
862 close_table_device(td
, md
);
866 mutex_unlock(&md
->table_devices_lock
);
868 EXPORT_SYMBOL(dm_put_table_device
);
870 static void free_table_devices(struct list_head
*devices
)
872 struct list_head
*tmp
, *next
;
874 list_for_each_safe(tmp
, next
, devices
) {
875 struct table_device
*td
= list_entry(tmp
, struct table_device
, list
);
877 DMWARN("dm_destroy: %s still exists with %d references",
878 td
->dm_dev
.name
, atomic_read(&td
->count
));
884 * Get the geometry associated with a dm device
886 int dm_get_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
894 * Set the geometry of a device.
896 int dm_set_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
898 sector_t sz
= (sector_t
)geo
->cylinders
* geo
->heads
* geo
->sectors
;
900 if (geo
->start
> sz
) {
901 DMWARN("Start sector is beyond the geometry limits.");
910 /*-----------------------------------------------------------------
912 * A more elegant soln is in the works that uses the queue
913 * merge fn, unfortunately there are a couple of changes to
914 * the block layer that I want to make for this. So in the
915 * interests of getting something for people to use I give
916 * you this clearly demarcated crap.
917 *---------------------------------------------------------------*/
919 static int __noflush_suspending(struct mapped_device
*md
)
921 return test_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
925 * Decrements the number of outstanding ios that a bio has been
926 * cloned into, completing the original io if necc.
928 static void dec_pending(struct dm_io
*io
, int error
)
933 struct mapped_device
*md
= io
->md
;
935 /* Push-back supersedes any I/O errors */
936 if (unlikely(error
)) {
937 spin_lock_irqsave(&io
->endio_lock
, flags
);
938 if (!(io
->error
> 0 && __noflush_suspending(md
)))
940 spin_unlock_irqrestore(&io
->endio_lock
, flags
);
943 if (atomic_dec_and_test(&io
->io_count
)) {
944 if (io
->error
== DM_ENDIO_REQUEUE
) {
946 * Target requested pushing back the I/O.
948 spin_lock_irqsave(&md
->deferred_lock
, flags
);
949 if (__noflush_suspending(md
))
950 bio_list_add_head(&md
->deferred
, io
->bio
);
952 /* noflush suspend was interrupted. */
954 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
957 io_error
= io
->error
;
962 if (io_error
== DM_ENDIO_REQUEUE
)
965 if ((bio
->bi_rw
& REQ_FLUSH
) && bio
->bi_iter
.bi_size
) {
967 * Preflush done for flush with data, reissue
970 bio
->bi_rw
&= ~REQ_FLUSH
;
973 /* done with normal IO or empty flush */
974 trace_block_bio_complete(md
->queue
, bio
, io_error
);
975 bio
->bi_error
= io_error
;
981 static void disable_write_same(struct mapped_device
*md
)
983 struct queue_limits
*limits
= dm_get_queue_limits(md
);
985 /* device doesn't really support WRITE SAME, disable it */
986 limits
->max_write_same_sectors
= 0;
989 static void clone_endio(struct bio
*bio
)
991 int error
= bio
->bi_error
;
993 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
994 struct dm_io
*io
= tio
->io
;
995 struct mapped_device
*md
= tio
->io
->md
;
996 dm_endio_fn endio
= tio
->ti
->type
->end_io
;
999 r
= endio(tio
->ti
, bio
, error
);
1000 if (r
< 0 || r
== DM_ENDIO_REQUEUE
)
1002 * error and requeue request are handled
1006 else if (r
== DM_ENDIO_INCOMPLETE
)
1007 /* The target will handle the io */
1010 DMWARN("unimplemented target endio return value: %d", r
);
1015 if (unlikely(r
== -EREMOTEIO
&& (bio
->bi_rw
& REQ_WRITE_SAME
) &&
1016 !bdev_get_queue(bio
->bi_bdev
)->limits
.max_write_same_sectors
))
1017 disable_write_same(md
);
1020 dec_pending(io
, error
);
1024 * Partial completion handling for request-based dm
1026 static void end_clone_bio(struct bio
*clone
)
1028 struct dm_rq_clone_bio_info
*info
=
1029 container_of(clone
, struct dm_rq_clone_bio_info
, clone
);
1030 struct dm_rq_target_io
*tio
= info
->tio
;
1031 struct bio
*bio
= info
->orig
;
1032 unsigned int nr_bytes
= info
->orig
->bi_iter
.bi_size
;
1038 * An error has already been detected on the request.
1039 * Once error occurred, just let clone->end_io() handle
1043 else if (bio
->bi_error
) {
1045 * Don't notice the error to the upper layer yet.
1046 * The error handling decision is made by the target driver,
1047 * when the request is completed.
1049 tio
->error
= bio
->bi_error
;
1054 * I/O for the bio successfully completed.
1055 * Notice the data completion to the upper layer.
1059 * bios are processed from the head of the list.
1060 * So the completing bio should always be rq->bio.
1061 * If it's not, something wrong is happening.
1063 if (tio
->orig
->bio
!= bio
)
1064 DMERR("bio completion is going in the middle of the request");
1067 * Update the original request.
1068 * Do not use blk_end_request() here, because it may complete
1069 * the original request before the clone, and break the ordering.
1071 blk_update_request(tio
->orig
, 0, nr_bytes
);
1074 static struct dm_rq_target_io
*tio_from_request(struct request
*rq
)
1076 return (rq
->q
->mq_ops
? blk_mq_rq_to_pdu(rq
) : rq
->special
);
1079 static void rq_end_stats(struct mapped_device
*md
, struct request
*orig
)
1081 if (unlikely(dm_stats_used(&md
->stats
))) {
1082 struct dm_rq_target_io
*tio
= tio_from_request(orig
);
1083 tio
->duration_jiffies
= jiffies
- tio
->duration_jiffies
;
1084 dm_stats_account_io(&md
->stats
, orig
->cmd_flags
, blk_rq_pos(orig
),
1085 tio
->n_sectors
, true, tio
->duration_jiffies
,
1091 * Don't touch any member of the md after calling this function because
1092 * the md may be freed in dm_put() at the end of this function.
1093 * Or do dm_get() before calling this function and dm_put() later.
1095 static void rq_completed(struct mapped_device
*md
, int rw
, bool run_queue
)
1097 atomic_dec(&md
->pending
[rw
]);
1099 /* nudge anyone waiting on suspend queue */
1100 if (!md_in_flight(md
))
1104 * Run this off this callpath, as drivers could invoke end_io while
1105 * inside their request_fn (and holding the queue lock). Calling
1106 * back into ->request_fn() could deadlock attempting to grab the
1110 if (md
->queue
->mq_ops
)
1111 blk_mq_run_hw_queues(md
->queue
, true);
1113 blk_run_queue_async(md
->queue
);
1117 * dm_put() must be at the end of this function. See the comment above
1122 static void free_rq_clone(struct request
*clone
)
1124 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1125 struct mapped_device
*md
= tio
->md
;
1127 blk_rq_unprep_clone(clone
);
1129 if (md
->type
== DM_TYPE_MQ_REQUEST_BASED
)
1130 /* stacked on blk-mq queue(s) */
1131 tio
->ti
->type
->release_clone_rq(clone
);
1132 else if (!md
->queue
->mq_ops
)
1133 /* request_fn queue stacked on request_fn queue(s) */
1134 free_clone_request(md
, clone
);
1136 * NOTE: for the blk-mq queue stacked on request_fn queue(s) case:
1137 * no need to call free_clone_request() because we leverage blk-mq by
1138 * allocating the clone at the end of the blk-mq pdu (see: clone_rq)
1141 if (!md
->queue
->mq_ops
)
1146 * Complete the clone and the original request.
1147 * Must be called without clone's queue lock held,
1148 * see end_clone_request() for more details.
1150 static void dm_end_request(struct request
*clone
, int error
)
1152 int rw
= rq_data_dir(clone
);
1153 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1154 struct mapped_device
*md
= tio
->md
;
1155 struct request
*rq
= tio
->orig
;
1157 if (rq
->cmd_type
== REQ_TYPE_BLOCK_PC
) {
1158 rq
->errors
= clone
->errors
;
1159 rq
->resid_len
= clone
->resid_len
;
1163 * We are using the sense buffer of the original
1165 * So setting the length of the sense data is enough.
1167 rq
->sense_len
= clone
->sense_len
;
1170 free_rq_clone(clone
);
1171 rq_end_stats(md
, rq
);
1173 blk_end_request_all(rq
, error
);
1175 blk_mq_end_request(rq
, error
);
1176 rq_completed(md
, rw
, true);
1179 static void dm_unprep_request(struct request
*rq
)
1181 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
1182 struct request
*clone
= tio
->clone
;
1184 if (!rq
->q
->mq_ops
) {
1186 rq
->cmd_flags
&= ~REQ_DONTPREP
;
1190 free_rq_clone(clone
);
1194 * Requeue the original request of a clone.
1196 static void old_requeue_request(struct request
*rq
)
1198 struct request_queue
*q
= rq
->q
;
1199 unsigned long flags
;
1201 spin_lock_irqsave(q
->queue_lock
, flags
);
1202 blk_requeue_request(q
, rq
);
1203 blk_run_queue_async(q
);
1204 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1207 static void dm_requeue_original_request(struct mapped_device
*md
,
1210 int rw
= rq_data_dir(rq
);
1212 dm_unprep_request(rq
);
1214 rq_end_stats(md
, rq
);
1216 old_requeue_request(rq
);
1218 blk_mq_requeue_request(rq
);
1219 blk_mq_kick_requeue_list(rq
->q
);
1222 rq_completed(md
, rw
, false);
1225 static void old_stop_queue(struct request_queue
*q
)
1227 unsigned long flags
;
1229 if (blk_queue_stopped(q
))
1232 spin_lock_irqsave(q
->queue_lock
, flags
);
1234 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1237 static void stop_queue(struct request_queue
*q
)
1242 blk_mq_stop_hw_queues(q
);
1245 static void old_start_queue(struct request_queue
*q
)
1247 unsigned long flags
;
1249 spin_lock_irqsave(q
->queue_lock
, flags
);
1250 if (blk_queue_stopped(q
))
1252 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1255 static void start_queue(struct request_queue
*q
)
1260 blk_mq_start_stopped_hw_queues(q
, true);
1263 static void dm_done(struct request
*clone
, int error
, bool mapped
)
1266 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1267 dm_request_endio_fn rq_end_io
= NULL
;
1270 rq_end_io
= tio
->ti
->type
->rq_end_io
;
1272 if (mapped
&& rq_end_io
)
1273 r
= rq_end_io(tio
->ti
, clone
, error
, &tio
->info
);
1276 if (unlikely(r
== -EREMOTEIO
&& (clone
->cmd_flags
& REQ_WRITE_SAME
) &&
1277 !clone
->q
->limits
.max_write_same_sectors
))
1278 disable_write_same(tio
->md
);
1281 /* The target wants to complete the I/O */
1282 dm_end_request(clone
, r
);
1283 else if (r
== DM_ENDIO_INCOMPLETE
)
1284 /* The target will handle the I/O */
1286 else if (r
== DM_ENDIO_REQUEUE
)
1287 /* The target wants to requeue the I/O */
1288 dm_requeue_original_request(tio
->md
, tio
->orig
);
1290 DMWARN("unimplemented target endio return value: %d", r
);
1296 * Request completion handler for request-based dm
1298 static void dm_softirq_done(struct request
*rq
)
1301 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
1302 struct request
*clone
= tio
->clone
;
1306 rq_end_stats(tio
->md
, rq
);
1307 rw
= rq_data_dir(rq
);
1308 if (!rq
->q
->mq_ops
) {
1309 blk_end_request_all(rq
, tio
->error
);
1310 rq_completed(tio
->md
, rw
, false);
1313 blk_mq_end_request(rq
, tio
->error
);
1314 rq_completed(tio
->md
, rw
, false);
1319 if (rq
->cmd_flags
& REQ_FAILED
)
1322 dm_done(clone
, tio
->error
, mapped
);
1326 * Complete the clone and the original request with the error status
1327 * through softirq context.
1329 static void dm_complete_request(struct request
*rq
, int error
)
1331 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
1334 blk_complete_request(rq
);
1338 * Complete the not-mapped clone and the original request with the error status
1339 * through softirq context.
1340 * Target's rq_end_io() function isn't called.
1341 * This may be used when the target's map_rq() or clone_and_map_rq() functions fail.
1343 static void dm_kill_unmapped_request(struct request
*rq
, int error
)
1345 rq
->cmd_flags
|= REQ_FAILED
;
1346 dm_complete_request(rq
, error
);
1350 * Called with the clone's queue lock held (for non-blk-mq)
1352 static void end_clone_request(struct request
*clone
, int error
)
1354 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1356 if (!clone
->q
->mq_ops
) {
1358 * For just cleaning up the information of the queue in which
1359 * the clone was dispatched.
1360 * The clone is *NOT* freed actually here because it is alloced
1361 * from dm own mempool (REQ_ALLOCED isn't set).
1363 __blk_put_request(clone
->q
, clone
);
1367 * Actual request completion is done in a softirq context which doesn't
1368 * hold the clone's queue lock. Otherwise, deadlock could occur because:
1369 * - another request may be submitted by the upper level driver
1370 * of the stacking during the completion
1371 * - the submission which requires queue lock may be done
1372 * against this clone's queue
1374 dm_complete_request(tio
->orig
, error
);
1378 * Return maximum size of I/O possible at the supplied sector up to the current
1381 static sector_t
max_io_len_target_boundary(sector_t sector
, struct dm_target
*ti
)
1383 sector_t target_offset
= dm_target_offset(ti
, sector
);
1385 return ti
->len
- target_offset
;
1388 static sector_t
max_io_len(sector_t sector
, struct dm_target
*ti
)
1390 sector_t len
= max_io_len_target_boundary(sector
, ti
);
1391 sector_t offset
, max_len
;
1394 * Does the target need to split even further?
1396 if (ti
->max_io_len
) {
1397 offset
= dm_target_offset(ti
, sector
);
1398 if (unlikely(ti
->max_io_len
& (ti
->max_io_len
- 1)))
1399 max_len
= sector_div(offset
, ti
->max_io_len
);
1401 max_len
= offset
& (ti
->max_io_len
- 1);
1402 max_len
= ti
->max_io_len
- max_len
;
1411 int dm_set_target_max_io_len(struct dm_target
*ti
, sector_t len
)
1413 if (len
> UINT_MAX
) {
1414 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1415 (unsigned long long)len
, UINT_MAX
);
1416 ti
->error
= "Maximum size of target IO is too large";
1420 ti
->max_io_len
= (uint32_t) len
;
1424 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len
);
1427 * A target may call dm_accept_partial_bio only from the map routine. It is
1428 * allowed for all bio types except REQ_FLUSH.
1430 * dm_accept_partial_bio informs the dm that the target only wants to process
1431 * additional n_sectors sectors of the bio and the rest of the data should be
1432 * sent in a next bio.
1434 * A diagram that explains the arithmetics:
1435 * +--------------------+---------------+-------+
1437 * +--------------------+---------------+-------+
1439 * <-------------- *tio->len_ptr --------------->
1440 * <------- bi_size ------->
1443 * Region 1 was already iterated over with bio_advance or similar function.
1444 * (it may be empty if the target doesn't use bio_advance)
1445 * Region 2 is the remaining bio size that the target wants to process.
1446 * (it may be empty if region 1 is non-empty, although there is no reason
1448 * The target requires that region 3 is to be sent in the next bio.
1450 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1451 * the partially processed part (the sum of regions 1+2) must be the same for all
1452 * copies of the bio.
1454 void dm_accept_partial_bio(struct bio
*bio
, unsigned n_sectors
)
1456 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
1457 unsigned bi_size
= bio
->bi_iter
.bi_size
>> SECTOR_SHIFT
;
1458 BUG_ON(bio
->bi_rw
& REQ_FLUSH
);
1459 BUG_ON(bi_size
> *tio
->len_ptr
);
1460 BUG_ON(n_sectors
> bi_size
);
1461 *tio
->len_ptr
-= bi_size
- n_sectors
;
1462 bio
->bi_iter
.bi_size
= n_sectors
<< SECTOR_SHIFT
;
1464 EXPORT_SYMBOL_GPL(dm_accept_partial_bio
);
1466 static void __map_bio(struct dm_target_io
*tio
)
1470 struct mapped_device
*md
;
1471 struct bio
*clone
= &tio
->clone
;
1472 struct dm_target
*ti
= tio
->ti
;
1474 clone
->bi_end_io
= clone_endio
;
1477 * Map the clone. If r == 0 we don't need to do
1478 * anything, the target has assumed ownership of
1481 atomic_inc(&tio
->io
->io_count
);
1482 sector
= clone
->bi_iter
.bi_sector
;
1483 r
= ti
->type
->map(ti
, clone
);
1484 if (r
== DM_MAPIO_REMAPPED
) {
1485 /* the bio has been remapped so dispatch it */
1487 trace_block_bio_remap(bdev_get_queue(clone
->bi_bdev
), clone
,
1488 tio
->io
->bio
->bi_bdev
->bd_dev
, sector
);
1490 generic_make_request(clone
);
1491 } else if (r
< 0 || r
== DM_MAPIO_REQUEUE
) {
1492 /* error the io and bail out, or requeue it if needed */
1494 dec_pending(tio
->io
, r
);
1496 } else if (r
!= DM_MAPIO_SUBMITTED
) {
1497 DMWARN("unimplemented target map return value: %d", r
);
1503 struct mapped_device
*md
;
1504 struct dm_table
*map
;
1508 unsigned sector_count
;
1511 static void bio_setup_sector(struct bio
*bio
, sector_t sector
, unsigned len
)
1513 bio
->bi_iter
.bi_sector
= sector
;
1514 bio
->bi_iter
.bi_size
= to_bytes(len
);
1518 * Creates a bio that consists of range of complete bvecs.
1520 static void clone_bio(struct dm_target_io
*tio
, struct bio
*bio
,
1521 sector_t sector
, unsigned len
)
1523 struct bio
*clone
= &tio
->clone
;
1525 __bio_clone_fast(clone
, bio
);
1527 if (bio_integrity(bio
))
1528 bio_integrity_clone(clone
, bio
, GFP_NOIO
);
1530 bio_advance(clone
, to_bytes(sector
- clone
->bi_iter
.bi_sector
));
1531 clone
->bi_iter
.bi_size
= to_bytes(len
);
1533 if (bio_integrity(bio
))
1534 bio_integrity_trim(clone
, 0, len
);
1537 static struct dm_target_io
*alloc_tio(struct clone_info
*ci
,
1538 struct dm_target
*ti
,
1539 unsigned target_bio_nr
)
1541 struct dm_target_io
*tio
;
1544 clone
= bio_alloc_bioset(GFP_NOIO
, 0, ci
->md
->bs
);
1545 tio
= container_of(clone
, struct dm_target_io
, clone
);
1549 tio
->target_bio_nr
= target_bio_nr
;
1554 static void __clone_and_map_simple_bio(struct clone_info
*ci
,
1555 struct dm_target
*ti
,
1556 unsigned target_bio_nr
, unsigned *len
)
1558 struct dm_target_io
*tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1559 struct bio
*clone
= &tio
->clone
;
1563 __bio_clone_fast(clone
, ci
->bio
);
1565 bio_setup_sector(clone
, ci
->sector
, *len
);
1570 static void __send_duplicate_bios(struct clone_info
*ci
, struct dm_target
*ti
,
1571 unsigned num_bios
, unsigned *len
)
1573 unsigned target_bio_nr
;
1575 for (target_bio_nr
= 0; target_bio_nr
< num_bios
; target_bio_nr
++)
1576 __clone_and_map_simple_bio(ci
, ti
, target_bio_nr
, len
);
1579 static int __send_empty_flush(struct clone_info
*ci
)
1581 unsigned target_nr
= 0;
1582 struct dm_target
*ti
;
1584 BUG_ON(bio_has_data(ci
->bio
));
1585 while ((ti
= dm_table_get_target(ci
->map
, target_nr
++)))
1586 __send_duplicate_bios(ci
, ti
, ti
->num_flush_bios
, NULL
);
1591 static void __clone_and_map_data_bio(struct clone_info
*ci
, struct dm_target
*ti
,
1592 sector_t sector
, unsigned *len
)
1594 struct bio
*bio
= ci
->bio
;
1595 struct dm_target_io
*tio
;
1596 unsigned target_bio_nr
;
1597 unsigned num_target_bios
= 1;
1600 * Does the target want to receive duplicate copies of the bio?
1602 if (bio_data_dir(bio
) == WRITE
&& ti
->num_write_bios
)
1603 num_target_bios
= ti
->num_write_bios(ti
, bio
);
1605 for (target_bio_nr
= 0; target_bio_nr
< num_target_bios
; target_bio_nr
++) {
1606 tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1608 clone_bio(tio
, bio
, sector
, *len
);
1613 typedef unsigned (*get_num_bios_fn
)(struct dm_target
*ti
);
1615 static unsigned get_num_discard_bios(struct dm_target
*ti
)
1617 return ti
->num_discard_bios
;
1620 static unsigned get_num_write_same_bios(struct dm_target
*ti
)
1622 return ti
->num_write_same_bios
;
1625 typedef bool (*is_split_required_fn
)(struct dm_target
*ti
);
1627 static bool is_split_required_for_discard(struct dm_target
*ti
)
1629 return ti
->split_discard_bios
;
1632 static int __send_changing_extent_only(struct clone_info
*ci
,
1633 get_num_bios_fn get_num_bios
,
1634 is_split_required_fn is_split_required
)
1636 struct dm_target
*ti
;
1641 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1642 if (!dm_target_is_valid(ti
))
1646 * Even though the device advertised support for this type of
1647 * request, that does not mean every target supports it, and
1648 * reconfiguration might also have changed that since the
1649 * check was performed.
1651 num_bios
= get_num_bios
? get_num_bios(ti
) : 0;
1655 if (is_split_required
&& !is_split_required(ti
))
1656 len
= min((sector_t
)ci
->sector_count
, max_io_len_target_boundary(ci
->sector
, ti
));
1658 len
= min((sector_t
)ci
->sector_count
, max_io_len(ci
->sector
, ti
));
1660 __send_duplicate_bios(ci
, ti
, num_bios
, &len
);
1663 } while (ci
->sector_count
-= len
);
1668 static int __send_discard(struct clone_info
*ci
)
1670 return __send_changing_extent_only(ci
, get_num_discard_bios
,
1671 is_split_required_for_discard
);
1674 static int __send_write_same(struct clone_info
*ci
)
1676 return __send_changing_extent_only(ci
, get_num_write_same_bios
, NULL
);
1680 * Select the correct strategy for processing a non-flush bio.
1682 static int __split_and_process_non_flush(struct clone_info
*ci
)
1684 struct bio
*bio
= ci
->bio
;
1685 struct dm_target
*ti
;
1688 if (unlikely(bio
->bi_rw
& REQ_DISCARD
))
1689 return __send_discard(ci
);
1690 else if (unlikely(bio
->bi_rw
& REQ_WRITE_SAME
))
1691 return __send_write_same(ci
);
1693 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1694 if (!dm_target_is_valid(ti
))
1697 len
= min_t(sector_t
, max_io_len(ci
->sector
, ti
), ci
->sector_count
);
1699 __clone_and_map_data_bio(ci
, ti
, ci
->sector
, &len
);
1702 ci
->sector_count
-= len
;
1708 * Entry point to split a bio into clones and submit them to the targets.
1710 static void __split_and_process_bio(struct mapped_device
*md
,
1711 struct dm_table
*map
, struct bio
*bio
)
1713 struct clone_info ci
;
1716 if (unlikely(!map
)) {
1723 ci
.io
= alloc_io(md
);
1725 atomic_set(&ci
.io
->io_count
, 1);
1728 spin_lock_init(&ci
.io
->endio_lock
);
1729 ci
.sector
= bio
->bi_iter
.bi_sector
;
1731 start_io_acct(ci
.io
);
1733 if (bio
->bi_rw
& REQ_FLUSH
) {
1734 ci
.bio
= &ci
.md
->flush_bio
;
1735 ci
.sector_count
= 0;
1736 error
= __send_empty_flush(&ci
);
1737 /* dec_pending submits any data associated with flush */
1740 ci
.sector_count
= bio_sectors(bio
);
1741 while (ci
.sector_count
&& !error
)
1742 error
= __split_and_process_non_flush(&ci
);
1745 /* drop the extra reference count */
1746 dec_pending(ci
.io
, error
);
1748 /*-----------------------------------------------------------------
1750 *---------------------------------------------------------------*/
1753 * The request function that just remaps the bio built up by
1756 static void dm_make_request(struct request_queue
*q
, struct bio
*bio
)
1758 int rw
= bio_data_dir(bio
);
1759 struct mapped_device
*md
= q
->queuedata
;
1761 struct dm_table
*map
;
1763 map
= dm_get_live_table(md
, &srcu_idx
);
1765 blk_queue_split(q
, &bio
, q
->bio_split
);
1767 generic_start_io_acct(rw
, bio_sectors(bio
), &dm_disk(md
)->part0
);
1769 /* if we're suspended, we have to queue this io for later */
1770 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))) {
1771 dm_put_live_table(md
, srcu_idx
);
1773 if (bio_rw(bio
) != READA
)
1780 __split_and_process_bio(md
, map
, bio
);
1781 dm_put_live_table(md
, srcu_idx
);
1785 int dm_request_based(struct mapped_device
*md
)
1787 return blk_queue_stackable(md
->queue
);
1790 static void dm_dispatch_clone_request(struct request
*clone
, struct request
*rq
)
1794 if (blk_queue_io_stat(clone
->q
))
1795 clone
->cmd_flags
|= REQ_IO_STAT
;
1797 clone
->start_time
= jiffies
;
1798 r
= blk_insert_cloned_request(clone
->q
, clone
);
1800 /* must complete clone in terms of original request */
1801 dm_complete_request(rq
, r
);
1804 static int dm_rq_bio_constructor(struct bio
*bio
, struct bio
*bio_orig
,
1807 struct dm_rq_target_io
*tio
= data
;
1808 struct dm_rq_clone_bio_info
*info
=
1809 container_of(bio
, struct dm_rq_clone_bio_info
, clone
);
1811 info
->orig
= bio_orig
;
1813 bio
->bi_end_io
= end_clone_bio
;
1818 static int setup_clone(struct request
*clone
, struct request
*rq
,
1819 struct dm_rq_target_io
*tio
, gfp_t gfp_mask
)
1823 r
= blk_rq_prep_clone(clone
, rq
, tio
->md
->bs
, gfp_mask
,
1824 dm_rq_bio_constructor
, tio
);
1828 clone
->cmd
= rq
->cmd
;
1829 clone
->cmd_len
= rq
->cmd_len
;
1830 clone
->sense
= rq
->sense
;
1831 clone
->end_io
= end_clone_request
;
1832 clone
->end_io_data
= tio
;
1839 static struct request
*clone_rq(struct request
*rq
, struct mapped_device
*md
,
1840 struct dm_rq_target_io
*tio
, gfp_t gfp_mask
)
1843 * Do not allocate a clone if tio->clone was already set
1844 * (see: dm_mq_queue_rq).
1846 bool alloc_clone
= !tio
->clone
;
1847 struct request
*clone
;
1850 clone
= alloc_clone_request(md
, gfp_mask
);
1856 blk_rq_init(NULL
, clone
);
1857 if (setup_clone(clone
, rq
, tio
, gfp_mask
)) {
1860 free_clone_request(md
, clone
);
1867 static void map_tio_request(struct kthread_work
*work
);
1869 static void init_tio(struct dm_rq_target_io
*tio
, struct request
*rq
,
1870 struct mapped_device
*md
)
1877 memset(&tio
->info
, 0, sizeof(tio
->info
));
1878 if (md
->kworker_task
)
1879 init_kthread_work(&tio
->work
, map_tio_request
);
1882 static struct dm_rq_target_io
*prep_tio(struct request
*rq
,
1883 struct mapped_device
*md
, gfp_t gfp_mask
)
1885 struct dm_rq_target_io
*tio
;
1887 struct dm_table
*table
;
1889 tio
= alloc_rq_tio(md
, gfp_mask
);
1893 init_tio(tio
, rq
, md
);
1895 table
= dm_get_live_table(md
, &srcu_idx
);
1896 if (!dm_table_mq_request_based(table
)) {
1897 if (!clone_rq(rq
, md
, tio
, gfp_mask
)) {
1898 dm_put_live_table(md
, srcu_idx
);
1903 dm_put_live_table(md
, srcu_idx
);
1909 * Called with the queue lock held.
1911 static int dm_prep_fn(struct request_queue
*q
, struct request
*rq
)
1913 struct mapped_device
*md
= q
->queuedata
;
1914 struct dm_rq_target_io
*tio
;
1916 if (unlikely(rq
->special
)) {
1917 DMWARN("Already has something in rq->special.");
1918 return BLKPREP_KILL
;
1921 tio
= prep_tio(rq
, md
, GFP_ATOMIC
);
1923 return BLKPREP_DEFER
;
1926 rq
->cmd_flags
|= REQ_DONTPREP
;
1933 * 0 : the request has been processed
1934 * DM_MAPIO_REQUEUE : the original request needs to be requeued
1935 * < 0 : the request was completed due to failure
1937 static int map_request(struct dm_rq_target_io
*tio
, struct request
*rq
,
1938 struct mapped_device
*md
)
1941 struct dm_target
*ti
= tio
->ti
;
1942 struct request
*clone
= NULL
;
1946 r
= ti
->type
->map_rq(ti
, clone
, &tio
->info
);
1948 r
= ti
->type
->clone_and_map_rq(ti
, rq
, &tio
->info
, &clone
);
1950 /* The target wants to complete the I/O */
1951 dm_kill_unmapped_request(rq
, r
);
1954 if (r
!= DM_MAPIO_REMAPPED
)
1956 if (setup_clone(clone
, rq
, tio
, GFP_ATOMIC
)) {
1958 ti
->type
->release_clone_rq(clone
);
1959 return DM_MAPIO_REQUEUE
;
1964 case DM_MAPIO_SUBMITTED
:
1965 /* The target has taken the I/O to submit by itself later */
1967 case DM_MAPIO_REMAPPED
:
1968 /* The target has remapped the I/O so dispatch it */
1969 trace_block_rq_remap(clone
->q
, clone
, disk_devt(dm_disk(md
)),
1971 dm_dispatch_clone_request(clone
, rq
);
1973 case DM_MAPIO_REQUEUE
:
1974 /* The target wants to requeue the I/O */
1975 dm_requeue_original_request(md
, tio
->orig
);
1979 DMWARN("unimplemented target map return value: %d", r
);
1983 /* The target wants to complete the I/O */
1984 dm_kill_unmapped_request(rq
, r
);
1991 static void map_tio_request(struct kthread_work
*work
)
1993 struct dm_rq_target_io
*tio
= container_of(work
, struct dm_rq_target_io
, work
);
1994 struct request
*rq
= tio
->orig
;
1995 struct mapped_device
*md
= tio
->md
;
1997 if (map_request(tio
, rq
, md
) == DM_MAPIO_REQUEUE
)
1998 dm_requeue_original_request(md
, rq
);
2001 static void dm_start_request(struct mapped_device
*md
, struct request
*orig
)
2003 if (!orig
->q
->mq_ops
)
2004 blk_start_request(orig
);
2006 blk_mq_start_request(orig
);
2007 atomic_inc(&md
->pending
[rq_data_dir(orig
)]);
2009 if (md
->seq_rq_merge_deadline_usecs
) {
2010 md
->last_rq_pos
= rq_end_sector(orig
);
2011 md
->last_rq_rw
= rq_data_dir(orig
);
2012 md
->last_rq_start_time
= ktime_get();
2015 if (unlikely(dm_stats_used(&md
->stats
))) {
2016 struct dm_rq_target_io
*tio
= tio_from_request(orig
);
2017 tio
->duration_jiffies
= jiffies
;
2018 tio
->n_sectors
= blk_rq_sectors(orig
);
2019 dm_stats_account_io(&md
->stats
, orig
->cmd_flags
, blk_rq_pos(orig
),
2020 tio
->n_sectors
, false, 0, &tio
->stats_aux
);
2024 * Hold the md reference here for the in-flight I/O.
2025 * We can't rely on the reference count by device opener,
2026 * because the device may be closed during the request completion
2027 * when all bios are completed.
2028 * See the comment in rq_completed() too.
2033 #define MAX_SEQ_RQ_MERGE_DEADLINE_USECS 100000
2035 ssize_t
dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device
*md
, char *buf
)
2037 return sprintf(buf
, "%u\n", md
->seq_rq_merge_deadline_usecs
);
2040 ssize_t
dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device
*md
,
2041 const char *buf
, size_t count
)
2045 if (!dm_request_based(md
) || md
->use_blk_mq
)
2048 if (kstrtouint(buf
, 10, &deadline
))
2051 if (deadline
> MAX_SEQ_RQ_MERGE_DEADLINE_USECS
)
2052 deadline
= MAX_SEQ_RQ_MERGE_DEADLINE_USECS
;
2054 md
->seq_rq_merge_deadline_usecs
= deadline
;
2059 static bool dm_request_peeked_before_merge_deadline(struct mapped_device
*md
)
2061 ktime_t kt_deadline
;
2063 if (!md
->seq_rq_merge_deadline_usecs
)
2066 kt_deadline
= ns_to_ktime((u64
)md
->seq_rq_merge_deadline_usecs
* NSEC_PER_USEC
);
2067 kt_deadline
= ktime_add_safe(md
->last_rq_start_time
, kt_deadline
);
2069 return !ktime_after(ktime_get(), kt_deadline
);
2073 * q->request_fn for request-based dm.
2074 * Called with the queue lock held.
2076 static void dm_request_fn(struct request_queue
*q
)
2078 struct mapped_device
*md
= q
->queuedata
;
2080 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
2081 struct dm_target
*ti
;
2083 struct dm_rq_target_io
*tio
;
2087 * For suspend, check blk_queue_stopped() and increment
2088 * ->pending within a single queue_lock not to increment the
2089 * number of in-flight I/Os after the queue is stopped in
2092 while (!blk_queue_stopped(q
)) {
2093 rq
= blk_peek_request(q
);
2097 /* always use block 0 to find the target for flushes for now */
2099 if (!(rq
->cmd_flags
& REQ_FLUSH
))
2100 pos
= blk_rq_pos(rq
);
2102 ti
= dm_table_find_target(map
, pos
);
2103 if (!dm_target_is_valid(ti
)) {
2105 * Must perform setup, that rq_completed() requires,
2106 * before calling dm_kill_unmapped_request
2108 DMERR_LIMIT("request attempted access beyond the end of device");
2109 dm_start_request(md
, rq
);
2110 dm_kill_unmapped_request(rq
, -EIO
);
2114 if (dm_request_peeked_before_merge_deadline(md
) &&
2115 md_in_flight(md
) && rq
->bio
&& rq
->bio
->bi_vcnt
== 1 &&
2116 md
->last_rq_pos
== pos
&& md
->last_rq_rw
== rq_data_dir(rq
))
2119 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
2122 dm_start_request(md
, rq
);
2124 tio
= tio_from_request(rq
);
2125 /* Establish tio->ti before queuing work (map_tio_request) */
2127 queue_kthread_work(&md
->kworker
, &tio
->work
);
2128 BUG_ON(!irqs_disabled());
2134 blk_delay_queue(q
, HZ
/ 100);
2136 dm_put_live_table(md
, srcu_idx
);
2139 static int dm_any_congested(void *congested_data
, int bdi_bits
)
2142 struct mapped_device
*md
= congested_data
;
2143 struct dm_table
*map
;
2145 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
2146 map
= dm_get_live_table_fast(md
);
2149 * Request-based dm cares about only own queue for
2150 * the query about congestion status of request_queue
2152 if (dm_request_based(md
))
2153 r
= md
->queue
->backing_dev_info
.wb
.state
&
2156 r
= dm_table_any_congested(map
, bdi_bits
);
2158 dm_put_live_table_fast(md
);
2164 /*-----------------------------------------------------------------
2165 * An IDR is used to keep track of allocated minor numbers.
2166 *---------------------------------------------------------------*/
2167 static void free_minor(int minor
)
2169 spin_lock(&_minor_lock
);
2170 idr_remove(&_minor_idr
, minor
);
2171 spin_unlock(&_minor_lock
);
2175 * See if the device with a specific minor # is free.
2177 static int specific_minor(int minor
)
2181 if (minor
>= (1 << MINORBITS
))
2184 idr_preload(GFP_KERNEL
);
2185 spin_lock(&_minor_lock
);
2187 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, minor
, minor
+ 1, GFP_NOWAIT
);
2189 spin_unlock(&_minor_lock
);
2192 return r
== -ENOSPC
? -EBUSY
: r
;
2196 static int next_free_minor(int *minor
)
2200 idr_preload(GFP_KERNEL
);
2201 spin_lock(&_minor_lock
);
2203 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, 0, 1 << MINORBITS
, GFP_NOWAIT
);
2205 spin_unlock(&_minor_lock
);
2213 static const struct block_device_operations dm_blk_dops
;
2215 static void dm_wq_work(struct work_struct
*work
);
2217 static void dm_init_md_queue(struct mapped_device
*md
)
2220 * Request-based dm devices cannot be stacked on top of bio-based dm
2221 * devices. The type of this dm device may not have been decided yet.
2222 * The type is decided at the first table loading time.
2223 * To prevent problematic device stacking, clear the queue flag
2224 * for request stacking support until then.
2226 * This queue is new, so no concurrency on the queue_flags.
2228 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE
, md
->queue
);
2231 * Initialize data that will only be used by a non-blk-mq DM queue
2232 * - must do so here (in alloc_dev callchain) before queue is used
2234 md
->queue
->queuedata
= md
;
2235 md
->queue
->backing_dev_info
.congested_data
= md
;
2238 static void dm_init_old_md_queue(struct mapped_device
*md
)
2240 md
->use_blk_mq
= false;
2241 dm_init_md_queue(md
);
2244 * Initialize aspects of queue that aren't relevant for blk-mq
2246 md
->queue
->backing_dev_info
.congested_fn
= dm_any_congested
;
2247 blk_queue_bounce_limit(md
->queue
, BLK_BOUNCE_ANY
);
2250 static void cleanup_mapped_device(struct mapped_device
*md
)
2253 destroy_workqueue(md
->wq
);
2254 if (md
->kworker_task
)
2255 kthread_stop(md
->kworker_task
);
2257 mempool_destroy(md
->io_pool
);
2259 mempool_destroy(md
->rq_pool
);
2261 bioset_free(md
->bs
);
2263 cleanup_srcu_struct(&md
->io_barrier
);
2266 spin_lock(&_minor_lock
);
2267 md
->disk
->private_data
= NULL
;
2268 spin_unlock(&_minor_lock
);
2269 if (blk_get_integrity(md
->disk
))
2270 blk_integrity_unregister(md
->disk
);
2271 del_gendisk(md
->disk
);
2276 blk_cleanup_queue(md
->queue
);
2285 * Allocate and initialise a blank device with a given minor.
2287 static struct mapped_device
*alloc_dev(int minor
)
2290 struct mapped_device
*md
= kzalloc(sizeof(*md
), GFP_KERNEL
);
2294 DMWARN("unable to allocate device, out of memory.");
2298 if (!try_module_get(THIS_MODULE
))
2299 goto bad_module_get
;
2301 /* get a minor number for the dev */
2302 if (minor
== DM_ANY_MINOR
)
2303 r
= next_free_minor(&minor
);
2305 r
= specific_minor(minor
);
2309 r
= init_srcu_struct(&md
->io_barrier
);
2311 goto bad_io_barrier
;
2313 md
->use_blk_mq
= use_blk_mq
;
2314 md
->type
= DM_TYPE_NONE
;
2315 mutex_init(&md
->suspend_lock
);
2316 mutex_init(&md
->type_lock
);
2317 mutex_init(&md
->table_devices_lock
);
2318 spin_lock_init(&md
->deferred_lock
);
2319 atomic_set(&md
->holders
, 1);
2320 atomic_set(&md
->open_count
, 0);
2321 atomic_set(&md
->event_nr
, 0);
2322 atomic_set(&md
->uevent_seq
, 0);
2323 INIT_LIST_HEAD(&md
->uevent_list
);
2324 INIT_LIST_HEAD(&md
->table_devices
);
2325 spin_lock_init(&md
->uevent_lock
);
2327 md
->queue
= blk_alloc_queue(GFP_KERNEL
);
2331 dm_init_md_queue(md
);
2333 md
->disk
= alloc_disk(1);
2337 atomic_set(&md
->pending
[0], 0);
2338 atomic_set(&md
->pending
[1], 0);
2339 init_waitqueue_head(&md
->wait
);
2340 INIT_WORK(&md
->work
, dm_wq_work
);
2341 init_waitqueue_head(&md
->eventq
);
2342 init_completion(&md
->kobj_holder
.completion
);
2343 md
->kworker_task
= NULL
;
2345 md
->disk
->major
= _major
;
2346 md
->disk
->first_minor
= minor
;
2347 md
->disk
->fops
= &dm_blk_dops
;
2348 md
->disk
->queue
= md
->queue
;
2349 md
->disk
->private_data
= md
;
2350 sprintf(md
->disk
->disk_name
, "dm-%d", minor
);
2352 format_dev_t(md
->name
, MKDEV(_major
, minor
));
2354 md
->wq
= alloc_workqueue("kdmflush", WQ_MEM_RECLAIM
, 0);
2358 md
->bdev
= bdget_disk(md
->disk
, 0);
2362 bio_init(&md
->flush_bio
);
2363 md
->flush_bio
.bi_bdev
= md
->bdev
;
2364 md
->flush_bio
.bi_rw
= WRITE_FLUSH
;
2366 dm_stats_init(&md
->stats
);
2368 /* Populate the mapping, nobody knows we exist yet */
2369 spin_lock(&_minor_lock
);
2370 old_md
= idr_replace(&_minor_idr
, md
, minor
);
2371 spin_unlock(&_minor_lock
);
2373 BUG_ON(old_md
!= MINOR_ALLOCED
);
2378 cleanup_mapped_device(md
);
2382 module_put(THIS_MODULE
);
2388 static void unlock_fs(struct mapped_device
*md
);
2390 static void free_dev(struct mapped_device
*md
)
2392 int minor
= MINOR(disk_devt(md
->disk
));
2396 cleanup_mapped_device(md
);
2398 blk_mq_free_tag_set(&md
->tag_set
);
2400 free_table_devices(&md
->table_devices
);
2401 dm_stats_cleanup(&md
->stats
);
2404 module_put(THIS_MODULE
);
2408 static void __bind_mempools(struct mapped_device
*md
, struct dm_table
*t
)
2410 struct dm_md_mempools
*p
= dm_table_get_md_mempools(t
);
2413 /* The md already has necessary mempools. */
2414 if (dm_table_get_type(t
) == DM_TYPE_BIO_BASED
) {
2416 * Reload bioset because front_pad may have changed
2417 * because a different table was loaded.
2419 bioset_free(md
->bs
);
2424 * There's no need to reload with request-based dm
2425 * because the size of front_pad doesn't change.
2426 * Note for future: If you are to reload bioset,
2427 * prep-ed requests in the queue may refer
2428 * to bio from the old bioset, so you must walk
2429 * through the queue to unprep.
2434 BUG_ON(!p
|| md
->io_pool
|| md
->rq_pool
|| md
->bs
);
2436 md
->io_pool
= p
->io_pool
;
2438 md
->rq_pool
= p
->rq_pool
;
2444 /* mempool bind completed, no longer need any mempools in the table */
2445 dm_table_free_md_mempools(t
);
2449 * Bind a table to the device.
2451 static void event_callback(void *context
)
2453 unsigned long flags
;
2455 struct mapped_device
*md
= (struct mapped_device
*) context
;
2457 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2458 list_splice_init(&md
->uevent_list
, &uevents
);
2459 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2461 dm_send_uevents(&uevents
, &disk_to_dev(md
->disk
)->kobj
);
2463 atomic_inc(&md
->event_nr
);
2464 wake_up(&md
->eventq
);
2468 * Protected by md->suspend_lock obtained by dm_swap_table().
2470 static void __set_size(struct mapped_device
*md
, sector_t size
)
2472 set_capacity(md
->disk
, size
);
2474 i_size_write(md
->bdev
->bd_inode
, (loff_t
)size
<< SECTOR_SHIFT
);
2478 * Returns old map, which caller must destroy.
2480 static struct dm_table
*__bind(struct mapped_device
*md
, struct dm_table
*t
,
2481 struct queue_limits
*limits
)
2483 struct dm_table
*old_map
;
2484 struct request_queue
*q
= md
->queue
;
2487 size
= dm_table_get_size(t
);
2490 * Wipe any geometry if the size of the table changed.
2492 if (size
!= dm_get_size(md
))
2493 memset(&md
->geometry
, 0, sizeof(md
->geometry
));
2495 __set_size(md
, size
);
2497 dm_table_event_callback(t
, event_callback
, md
);
2500 * The queue hasn't been stopped yet, if the old table type wasn't
2501 * for request-based during suspension. So stop it to prevent
2502 * I/O mapping before resume.
2503 * This must be done before setting the queue restrictions,
2504 * because request-based dm may be run just after the setting.
2506 if (dm_table_request_based(t
))
2509 __bind_mempools(md
, t
);
2511 old_map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
2512 rcu_assign_pointer(md
->map
, t
);
2513 md
->immutable_target_type
= dm_table_get_immutable_target_type(t
);
2515 dm_table_set_restrictions(t
, q
, limits
);
2523 * Returns unbound table for the caller to free.
2525 static struct dm_table
*__unbind(struct mapped_device
*md
)
2527 struct dm_table
*map
= rcu_dereference_protected(md
->map
, 1);
2532 dm_table_event_callback(map
, NULL
, NULL
);
2533 RCU_INIT_POINTER(md
->map
, NULL
);
2540 * Constructor for a new device.
2542 int dm_create(int minor
, struct mapped_device
**result
)
2544 struct mapped_device
*md
;
2546 md
= alloc_dev(minor
);
2557 * Functions to manage md->type.
2558 * All are required to hold md->type_lock.
2560 void dm_lock_md_type(struct mapped_device
*md
)
2562 mutex_lock(&md
->type_lock
);
2565 void dm_unlock_md_type(struct mapped_device
*md
)
2567 mutex_unlock(&md
->type_lock
);
2570 void dm_set_md_type(struct mapped_device
*md
, unsigned type
)
2572 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2576 unsigned dm_get_md_type(struct mapped_device
*md
)
2578 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2582 struct target_type
*dm_get_immutable_target_type(struct mapped_device
*md
)
2584 return md
->immutable_target_type
;
2588 * The queue_limits are only valid as long as you have a reference
2591 struct queue_limits
*dm_get_queue_limits(struct mapped_device
*md
)
2593 BUG_ON(!atomic_read(&md
->holders
));
2594 return &md
->queue
->limits
;
2596 EXPORT_SYMBOL_GPL(dm_get_queue_limits
);
2598 static void init_rq_based_worker_thread(struct mapped_device
*md
)
2600 /* Initialize the request-based DM worker thread */
2601 init_kthread_worker(&md
->kworker
);
2602 md
->kworker_task
= kthread_run(kthread_worker_fn
, &md
->kworker
,
2603 "kdmwork-%s", dm_device_name(md
));
2607 * Fully initialize a request-based queue (->elevator, ->request_fn, etc).
2609 static int dm_init_request_based_queue(struct mapped_device
*md
)
2611 struct request_queue
*q
= NULL
;
2613 /* Fully initialize the queue */
2614 q
= blk_init_allocated_queue(md
->queue
, dm_request_fn
, NULL
);
2618 /* disable dm_request_fn's merge heuristic by default */
2619 md
->seq_rq_merge_deadline_usecs
= 0;
2622 dm_init_old_md_queue(md
);
2623 blk_queue_softirq_done(md
->queue
, dm_softirq_done
);
2624 blk_queue_prep_rq(md
->queue
, dm_prep_fn
);
2626 init_rq_based_worker_thread(md
);
2628 elv_register_queue(md
->queue
);
2633 static int dm_mq_init_request(void *data
, struct request
*rq
,
2634 unsigned int hctx_idx
, unsigned int request_idx
,
2635 unsigned int numa_node
)
2637 struct mapped_device
*md
= data
;
2638 struct dm_rq_target_io
*tio
= blk_mq_rq_to_pdu(rq
);
2641 * Must initialize md member of tio, otherwise it won't
2642 * be available in dm_mq_queue_rq.
2649 static int dm_mq_queue_rq(struct blk_mq_hw_ctx
*hctx
,
2650 const struct blk_mq_queue_data
*bd
)
2652 struct request
*rq
= bd
->rq
;
2653 struct dm_rq_target_io
*tio
= blk_mq_rq_to_pdu(rq
);
2654 struct mapped_device
*md
= tio
->md
;
2656 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
2657 struct dm_target
*ti
;
2660 /* always use block 0 to find the target for flushes for now */
2662 if (!(rq
->cmd_flags
& REQ_FLUSH
))
2663 pos
= blk_rq_pos(rq
);
2665 ti
= dm_table_find_target(map
, pos
);
2666 if (!dm_target_is_valid(ti
)) {
2667 dm_put_live_table(md
, srcu_idx
);
2668 DMERR_LIMIT("request attempted access beyond the end of device");
2670 * Must perform setup, that rq_completed() requires,
2671 * before returning BLK_MQ_RQ_QUEUE_ERROR
2673 dm_start_request(md
, rq
);
2674 return BLK_MQ_RQ_QUEUE_ERROR
;
2676 dm_put_live_table(md
, srcu_idx
);
2678 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
2679 return BLK_MQ_RQ_QUEUE_BUSY
;
2681 dm_start_request(md
, rq
);
2683 /* Init tio using md established in .init_request */
2684 init_tio(tio
, rq
, md
);
2687 * Establish tio->ti before queuing work (map_tio_request)
2688 * or making direct call to map_request().
2692 /* Clone the request if underlying devices aren't blk-mq */
2693 if (dm_table_get_type(map
) == DM_TYPE_REQUEST_BASED
) {
2694 /* clone request is allocated at the end of the pdu */
2695 tio
->clone
= (void *)blk_mq_rq_to_pdu(rq
) + sizeof(struct dm_rq_target_io
);
2696 (void) clone_rq(rq
, md
, tio
, GFP_ATOMIC
);
2697 queue_kthread_work(&md
->kworker
, &tio
->work
);
2699 /* Direct call is fine since .queue_rq allows allocations */
2700 if (map_request(tio
, rq
, md
) == DM_MAPIO_REQUEUE
) {
2701 /* Undo dm_start_request() before requeuing */
2702 rq_end_stats(md
, rq
);
2703 rq_completed(md
, rq_data_dir(rq
), false);
2704 return BLK_MQ_RQ_QUEUE_BUSY
;
2708 return BLK_MQ_RQ_QUEUE_OK
;
2711 static struct blk_mq_ops dm_mq_ops
= {
2712 .queue_rq
= dm_mq_queue_rq
,
2713 .map_queue
= blk_mq_map_queue
,
2714 .complete
= dm_softirq_done
,
2715 .init_request
= dm_mq_init_request
,
2718 static int dm_init_request_based_blk_mq_queue(struct mapped_device
*md
)
2720 unsigned md_type
= dm_get_md_type(md
);
2721 struct request_queue
*q
;
2724 memset(&md
->tag_set
, 0, sizeof(md
->tag_set
));
2725 md
->tag_set
.ops
= &dm_mq_ops
;
2726 md
->tag_set
.queue_depth
= BLKDEV_MAX_RQ
;
2727 md
->tag_set
.numa_node
= NUMA_NO_NODE
;
2728 md
->tag_set
.flags
= BLK_MQ_F_SHOULD_MERGE
| BLK_MQ_F_SG_MERGE
;
2729 md
->tag_set
.nr_hw_queues
= 1;
2730 if (md_type
== DM_TYPE_REQUEST_BASED
) {
2731 /* make the memory for non-blk-mq clone part of the pdu */
2732 md
->tag_set
.cmd_size
= sizeof(struct dm_rq_target_io
) + sizeof(struct request
);
2734 md
->tag_set
.cmd_size
= sizeof(struct dm_rq_target_io
);
2735 md
->tag_set
.driver_data
= md
;
2737 err
= blk_mq_alloc_tag_set(&md
->tag_set
);
2741 q
= blk_mq_init_allocated_queue(&md
->tag_set
, md
->queue
);
2747 dm_init_md_queue(md
);
2749 /* backfill 'mq' sysfs registration normally done in blk_register_queue */
2750 blk_mq_register_disk(md
->disk
);
2752 if (md_type
== DM_TYPE_REQUEST_BASED
)
2753 init_rq_based_worker_thread(md
);
2758 blk_mq_free_tag_set(&md
->tag_set
);
2762 static unsigned filter_md_type(unsigned type
, struct mapped_device
*md
)
2764 if (type
== DM_TYPE_BIO_BASED
)
2767 return !md
->use_blk_mq
? DM_TYPE_REQUEST_BASED
: DM_TYPE_MQ_REQUEST_BASED
;
2771 * Setup the DM device's queue based on md's type
2773 int dm_setup_md_queue(struct mapped_device
*md
)
2776 unsigned md_type
= filter_md_type(dm_get_md_type(md
), md
);
2779 case DM_TYPE_REQUEST_BASED
:
2780 r
= dm_init_request_based_queue(md
);
2782 DMWARN("Cannot initialize queue for request-based mapped device");
2786 case DM_TYPE_MQ_REQUEST_BASED
:
2787 r
= dm_init_request_based_blk_mq_queue(md
);
2789 DMWARN("Cannot initialize queue for request-based blk-mq mapped device");
2793 case DM_TYPE_BIO_BASED
:
2794 dm_init_old_md_queue(md
);
2795 blk_queue_make_request(md
->queue
, dm_make_request
);
2802 struct mapped_device
*dm_get_md(dev_t dev
)
2804 struct mapped_device
*md
;
2805 unsigned minor
= MINOR(dev
);
2807 if (MAJOR(dev
) != _major
|| minor
>= (1 << MINORBITS
))
2810 spin_lock(&_minor_lock
);
2812 md
= idr_find(&_minor_idr
, minor
);
2814 if ((md
== MINOR_ALLOCED
||
2815 (MINOR(disk_devt(dm_disk(md
))) != minor
) ||
2816 dm_deleting_md(md
) ||
2817 test_bit(DMF_FREEING
, &md
->flags
))) {
2825 spin_unlock(&_minor_lock
);
2829 EXPORT_SYMBOL_GPL(dm_get_md
);
2831 void *dm_get_mdptr(struct mapped_device
*md
)
2833 return md
->interface_ptr
;
2836 void dm_set_mdptr(struct mapped_device
*md
, void *ptr
)
2838 md
->interface_ptr
= ptr
;
2841 void dm_get(struct mapped_device
*md
)
2843 atomic_inc(&md
->holders
);
2844 BUG_ON(test_bit(DMF_FREEING
, &md
->flags
));
2847 int dm_hold(struct mapped_device
*md
)
2849 spin_lock(&_minor_lock
);
2850 if (test_bit(DMF_FREEING
, &md
->flags
)) {
2851 spin_unlock(&_minor_lock
);
2855 spin_unlock(&_minor_lock
);
2858 EXPORT_SYMBOL_GPL(dm_hold
);
2860 const char *dm_device_name(struct mapped_device
*md
)
2864 EXPORT_SYMBOL_GPL(dm_device_name
);
2866 static void __dm_destroy(struct mapped_device
*md
, bool wait
)
2868 struct dm_table
*map
;
2873 map
= dm_get_live_table(md
, &srcu_idx
);
2875 spin_lock(&_minor_lock
);
2876 idr_replace(&_minor_idr
, MINOR_ALLOCED
, MINOR(disk_devt(dm_disk(md
))));
2877 set_bit(DMF_FREEING
, &md
->flags
);
2878 spin_unlock(&_minor_lock
);
2880 if (dm_request_based(md
) && md
->kworker_task
)
2881 flush_kthread_worker(&md
->kworker
);
2884 * Take suspend_lock so that presuspend and postsuspend methods
2885 * do not race with internal suspend.
2887 mutex_lock(&md
->suspend_lock
);
2888 if (!dm_suspended_md(md
)) {
2889 dm_table_presuspend_targets(map
);
2890 dm_table_postsuspend_targets(map
);
2892 mutex_unlock(&md
->suspend_lock
);
2894 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2895 dm_put_live_table(md
, srcu_idx
);
2898 * Rare, but there may be I/O requests still going to complete,
2899 * for example. Wait for all references to disappear.
2900 * No one should increment the reference count of the mapped_device,
2901 * after the mapped_device state becomes DMF_FREEING.
2904 while (atomic_read(&md
->holders
))
2906 else if (atomic_read(&md
->holders
))
2907 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2908 dm_device_name(md
), atomic_read(&md
->holders
));
2911 dm_table_destroy(__unbind(md
));
2915 void dm_destroy(struct mapped_device
*md
)
2917 __dm_destroy(md
, true);
2920 void dm_destroy_immediate(struct mapped_device
*md
)
2922 __dm_destroy(md
, false);
2925 void dm_put(struct mapped_device
*md
)
2927 atomic_dec(&md
->holders
);
2929 EXPORT_SYMBOL_GPL(dm_put
);
2931 static int dm_wait_for_completion(struct mapped_device
*md
, int interruptible
)
2934 DECLARE_WAITQUEUE(wait
, current
);
2936 add_wait_queue(&md
->wait
, &wait
);
2939 set_current_state(interruptible
);
2941 if (!md_in_flight(md
))
2944 if (interruptible
== TASK_INTERRUPTIBLE
&&
2945 signal_pending(current
)) {
2952 set_current_state(TASK_RUNNING
);
2954 remove_wait_queue(&md
->wait
, &wait
);
2960 * Process the deferred bios
2962 static void dm_wq_work(struct work_struct
*work
)
2964 struct mapped_device
*md
= container_of(work
, struct mapped_device
,
2968 struct dm_table
*map
;
2970 map
= dm_get_live_table(md
, &srcu_idx
);
2972 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
2973 spin_lock_irq(&md
->deferred_lock
);
2974 c
= bio_list_pop(&md
->deferred
);
2975 spin_unlock_irq(&md
->deferred_lock
);
2980 if (dm_request_based(md
))
2981 generic_make_request(c
);
2983 __split_and_process_bio(md
, map
, c
);
2986 dm_put_live_table(md
, srcu_idx
);
2989 static void dm_queue_flush(struct mapped_device
*md
)
2991 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2992 smp_mb__after_atomic();
2993 queue_work(md
->wq
, &md
->work
);
2997 * Swap in a new table, returning the old one for the caller to destroy.
2999 struct dm_table
*dm_swap_table(struct mapped_device
*md
, struct dm_table
*table
)
3001 struct dm_table
*live_map
= NULL
, *map
= ERR_PTR(-EINVAL
);
3002 struct queue_limits limits
;
3005 mutex_lock(&md
->suspend_lock
);
3007 /* device must be suspended */
3008 if (!dm_suspended_md(md
))
3012 * If the new table has no data devices, retain the existing limits.
3013 * This helps multipath with queue_if_no_path if all paths disappear,
3014 * then new I/O is queued based on these limits, and then some paths
3017 if (dm_table_has_no_data_devices(table
)) {
3018 live_map
= dm_get_live_table_fast(md
);
3020 limits
= md
->queue
->limits
;
3021 dm_put_live_table_fast(md
);
3025 r
= dm_calculate_queue_limits(table
, &limits
);
3032 map
= __bind(md
, table
, &limits
);
3035 mutex_unlock(&md
->suspend_lock
);
3040 * Functions to lock and unlock any filesystem running on the
3043 static int lock_fs(struct mapped_device
*md
)
3047 WARN_ON(md
->frozen_sb
);
3049 md
->frozen_sb
= freeze_bdev(md
->bdev
);
3050 if (IS_ERR(md
->frozen_sb
)) {
3051 r
= PTR_ERR(md
->frozen_sb
);
3052 md
->frozen_sb
= NULL
;
3056 set_bit(DMF_FROZEN
, &md
->flags
);
3061 static void unlock_fs(struct mapped_device
*md
)
3063 if (!test_bit(DMF_FROZEN
, &md
->flags
))
3066 thaw_bdev(md
->bdev
, md
->frozen_sb
);
3067 md
->frozen_sb
= NULL
;
3068 clear_bit(DMF_FROZEN
, &md
->flags
);
3072 * If __dm_suspend returns 0, the device is completely quiescent
3073 * now. There is no request-processing activity. All new requests
3074 * are being added to md->deferred list.
3076 * Caller must hold md->suspend_lock
3078 static int __dm_suspend(struct mapped_device
*md
, struct dm_table
*map
,
3079 unsigned suspend_flags
, int interruptible
)
3081 bool do_lockfs
= suspend_flags
& DM_SUSPEND_LOCKFS_FLAG
;
3082 bool noflush
= suspend_flags
& DM_SUSPEND_NOFLUSH_FLAG
;
3086 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
3087 * This flag is cleared before dm_suspend returns.
3090 set_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
3093 * This gets reverted if there's an error later and the targets
3094 * provide the .presuspend_undo hook.
3096 dm_table_presuspend_targets(map
);
3099 * Flush I/O to the device.
3100 * Any I/O submitted after lock_fs() may not be flushed.
3101 * noflush takes precedence over do_lockfs.
3102 * (lock_fs() flushes I/Os and waits for them to complete.)
3104 if (!noflush
&& do_lockfs
) {
3107 dm_table_presuspend_undo_targets(map
);
3113 * Here we must make sure that no processes are submitting requests
3114 * to target drivers i.e. no one may be executing
3115 * __split_and_process_bio. This is called from dm_request and
3118 * To get all processes out of __split_and_process_bio in dm_request,
3119 * we take the write lock. To prevent any process from reentering
3120 * __split_and_process_bio from dm_request and quiesce the thread
3121 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
3122 * flush_workqueue(md->wq).
3124 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
3126 synchronize_srcu(&md
->io_barrier
);
3129 * Stop md->queue before flushing md->wq in case request-based
3130 * dm defers requests to md->wq from md->queue.
3132 if (dm_request_based(md
)) {
3133 stop_queue(md
->queue
);
3134 if (md
->kworker_task
)
3135 flush_kthread_worker(&md
->kworker
);
3138 flush_workqueue(md
->wq
);
3141 * At this point no more requests are entering target request routines.
3142 * We call dm_wait_for_completion to wait for all existing requests
3145 r
= dm_wait_for_completion(md
, interruptible
);
3148 clear_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
3150 synchronize_srcu(&md
->io_barrier
);
3152 /* were we interrupted ? */
3156 if (dm_request_based(md
))
3157 start_queue(md
->queue
);
3160 dm_table_presuspend_undo_targets(map
);
3161 /* pushback list is already flushed, so skip flush */
3168 * We need to be able to change a mapping table under a mounted
3169 * filesystem. For example we might want to move some data in
3170 * the background. Before the table can be swapped with
3171 * dm_bind_table, dm_suspend must be called to flush any in
3172 * flight bios and ensure that any further io gets deferred.
3175 * Suspend mechanism in request-based dm.
3177 * 1. Flush all I/Os by lock_fs() if needed.
3178 * 2. Stop dispatching any I/O by stopping the request_queue.
3179 * 3. Wait for all in-flight I/Os to be completed or requeued.
3181 * To abort suspend, start the request_queue.
3183 int dm_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
3185 struct dm_table
*map
= NULL
;
3189 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
3191 if (dm_suspended_md(md
)) {
3196 if (dm_suspended_internally_md(md
)) {
3197 /* already internally suspended, wait for internal resume */
3198 mutex_unlock(&md
->suspend_lock
);
3199 r
= wait_on_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
, TASK_INTERRUPTIBLE
);
3205 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
3207 r
= __dm_suspend(md
, map
, suspend_flags
, TASK_INTERRUPTIBLE
);
3211 set_bit(DMF_SUSPENDED
, &md
->flags
);
3213 dm_table_postsuspend_targets(map
);
3216 mutex_unlock(&md
->suspend_lock
);
3220 static int __dm_resume(struct mapped_device
*md
, struct dm_table
*map
)
3223 int r
= dm_table_resume_targets(map
);
3231 * Flushing deferred I/Os must be done after targets are resumed
3232 * so that mapping of targets can work correctly.
3233 * Request-based dm is queueing the deferred I/Os in its request_queue.
3235 if (dm_request_based(md
))
3236 start_queue(md
->queue
);
3243 int dm_resume(struct mapped_device
*md
)
3246 struct dm_table
*map
= NULL
;
3249 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
3251 if (!dm_suspended_md(md
))
3254 if (dm_suspended_internally_md(md
)) {
3255 /* already internally suspended, wait for internal resume */
3256 mutex_unlock(&md
->suspend_lock
);
3257 r
= wait_on_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
, TASK_INTERRUPTIBLE
);
3263 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
3264 if (!map
|| !dm_table_get_size(map
))
3267 r
= __dm_resume(md
, map
);
3271 clear_bit(DMF_SUSPENDED
, &md
->flags
);
3275 mutex_unlock(&md
->suspend_lock
);
3281 * Internal suspend/resume works like userspace-driven suspend. It waits
3282 * until all bios finish and prevents issuing new bios to the target drivers.
3283 * It may be used only from the kernel.
3286 static void __dm_internal_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
3288 struct dm_table
*map
= NULL
;
3290 if (md
->internal_suspend_count
++)
3291 return; /* nested internal suspend */
3293 if (dm_suspended_md(md
)) {
3294 set_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3295 return; /* nest suspend */
3298 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
3301 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
3302 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
3303 * would require changing .presuspend to return an error -- avoid this
3304 * until there is a need for more elaborate variants of internal suspend.
3306 (void) __dm_suspend(md
, map
, suspend_flags
, TASK_UNINTERRUPTIBLE
);
3308 set_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3310 dm_table_postsuspend_targets(map
);
3313 static void __dm_internal_resume(struct mapped_device
*md
)
3315 BUG_ON(!md
->internal_suspend_count
);
3317 if (--md
->internal_suspend_count
)
3318 return; /* resume from nested internal suspend */
3320 if (dm_suspended_md(md
))
3321 goto done
; /* resume from nested suspend */
3324 * NOTE: existing callers don't need to call dm_table_resume_targets
3325 * (which may fail -- so best to avoid it for now by passing NULL map)
3327 (void) __dm_resume(md
, NULL
);
3330 clear_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3331 smp_mb__after_atomic();
3332 wake_up_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
);
3335 void dm_internal_suspend_noflush(struct mapped_device
*md
)
3337 mutex_lock(&md
->suspend_lock
);
3338 __dm_internal_suspend(md
, DM_SUSPEND_NOFLUSH_FLAG
);
3339 mutex_unlock(&md
->suspend_lock
);
3341 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush
);
3343 void dm_internal_resume(struct mapped_device
*md
)
3345 mutex_lock(&md
->suspend_lock
);
3346 __dm_internal_resume(md
);
3347 mutex_unlock(&md
->suspend_lock
);
3349 EXPORT_SYMBOL_GPL(dm_internal_resume
);
3352 * Fast variants of internal suspend/resume hold md->suspend_lock,
3353 * which prevents interaction with userspace-driven suspend.
3356 void dm_internal_suspend_fast(struct mapped_device
*md
)
3358 mutex_lock(&md
->suspend_lock
);
3359 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
3362 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
3363 synchronize_srcu(&md
->io_barrier
);
3364 flush_workqueue(md
->wq
);
3365 dm_wait_for_completion(md
, TASK_UNINTERRUPTIBLE
);
3367 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast
);
3369 void dm_internal_resume_fast(struct mapped_device
*md
)
3371 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
3377 mutex_unlock(&md
->suspend_lock
);
3379 EXPORT_SYMBOL_GPL(dm_internal_resume_fast
);
3381 /*-----------------------------------------------------------------
3382 * Event notification.
3383 *---------------------------------------------------------------*/
3384 int dm_kobject_uevent(struct mapped_device
*md
, enum kobject_action action
,
3387 char udev_cookie
[DM_COOKIE_LENGTH
];
3388 char *envp
[] = { udev_cookie
, NULL
};
3391 return kobject_uevent(&disk_to_dev(md
->disk
)->kobj
, action
);
3393 snprintf(udev_cookie
, DM_COOKIE_LENGTH
, "%s=%u",
3394 DM_COOKIE_ENV_VAR_NAME
, cookie
);
3395 return kobject_uevent_env(&disk_to_dev(md
->disk
)->kobj
,
3400 uint32_t dm_next_uevent_seq(struct mapped_device
*md
)
3402 return atomic_add_return(1, &md
->uevent_seq
);
3405 uint32_t dm_get_event_nr(struct mapped_device
*md
)
3407 return atomic_read(&md
->event_nr
);
3410 int dm_wait_event(struct mapped_device
*md
, int event_nr
)
3412 return wait_event_interruptible(md
->eventq
,
3413 (event_nr
!= atomic_read(&md
->event_nr
)));
3416 void dm_uevent_add(struct mapped_device
*md
, struct list_head
*elist
)
3418 unsigned long flags
;
3420 spin_lock_irqsave(&md
->uevent_lock
, flags
);
3421 list_add(elist
, &md
->uevent_list
);
3422 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
3426 * The gendisk is only valid as long as you have a reference
3429 struct gendisk
*dm_disk(struct mapped_device
*md
)
3433 EXPORT_SYMBOL_GPL(dm_disk
);
3435 struct kobject
*dm_kobject(struct mapped_device
*md
)
3437 return &md
->kobj_holder
.kobj
;
3440 struct mapped_device
*dm_get_from_kobject(struct kobject
*kobj
)
3442 struct mapped_device
*md
;
3444 md
= container_of(kobj
, struct mapped_device
, kobj_holder
.kobj
);
3446 if (test_bit(DMF_FREEING
, &md
->flags
) ||
3454 int dm_suspended_md(struct mapped_device
*md
)
3456 return test_bit(DMF_SUSPENDED
, &md
->flags
);
3459 int dm_suspended_internally_md(struct mapped_device
*md
)
3461 return test_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3464 int dm_test_deferred_remove_flag(struct mapped_device
*md
)
3466 return test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
3469 int dm_suspended(struct dm_target
*ti
)
3471 return dm_suspended_md(dm_table_get_md(ti
->table
));
3473 EXPORT_SYMBOL_GPL(dm_suspended
);
3475 int dm_noflush_suspending(struct dm_target
*ti
)
3477 return __noflush_suspending(dm_table_get_md(ti
->table
));
3479 EXPORT_SYMBOL_GPL(dm_noflush_suspending
);
3481 struct dm_md_mempools
*dm_alloc_md_mempools(struct mapped_device
*md
, unsigned type
,
3482 unsigned integrity
, unsigned per_bio_data_size
)
3484 struct dm_md_mempools
*pools
= kzalloc(sizeof(*pools
), GFP_KERNEL
);
3485 struct kmem_cache
*cachep
= NULL
;
3486 unsigned int pool_size
= 0;
3487 unsigned int front_pad
;
3492 type
= filter_md_type(type
, md
);
3495 case DM_TYPE_BIO_BASED
:
3497 pool_size
= dm_get_reserved_bio_based_ios();
3498 front_pad
= roundup(per_bio_data_size
, __alignof__(struct dm_target_io
)) + offsetof(struct dm_target_io
, clone
);
3500 case DM_TYPE_REQUEST_BASED
:
3501 cachep
= _rq_tio_cache
;
3502 pool_size
= dm_get_reserved_rq_based_ios();
3503 pools
->rq_pool
= mempool_create_slab_pool(pool_size
, _rq_cache
);
3504 if (!pools
->rq_pool
)
3506 /* fall through to setup remaining rq-based pools */
3507 case DM_TYPE_MQ_REQUEST_BASED
:
3509 pool_size
= dm_get_reserved_rq_based_ios();
3510 front_pad
= offsetof(struct dm_rq_clone_bio_info
, clone
);
3511 /* per_bio_data_size is not used. See __bind_mempools(). */
3512 WARN_ON(per_bio_data_size
!= 0);
3519 pools
->io_pool
= mempool_create_slab_pool(pool_size
, cachep
);
3520 if (!pools
->io_pool
)
3524 pools
->bs
= bioset_create_nobvec(pool_size
, front_pad
);
3528 if (integrity
&& bioset_integrity_create(pools
->bs
, pool_size
))
3534 dm_free_md_mempools(pools
);
3539 void dm_free_md_mempools(struct dm_md_mempools
*pools
)
3545 mempool_destroy(pools
->io_pool
);
3548 mempool_destroy(pools
->rq_pool
);
3551 bioset_free(pools
->bs
);
3556 static const struct block_device_operations dm_blk_dops
= {
3557 .open
= dm_blk_open
,
3558 .release
= dm_blk_close
,
3559 .ioctl
= dm_blk_ioctl
,
3560 .getgeo
= dm_blk_getgeo
,
3561 .owner
= THIS_MODULE
3567 module_init(dm_init
);
3568 module_exit(dm_exit
);
3570 module_param(major
, uint
, 0);
3571 MODULE_PARM_DESC(major
, "The major number of the device mapper");
3573 module_param(reserved_bio_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
3574 MODULE_PARM_DESC(reserved_bio_based_ios
, "Reserved IOs in bio-based mempools");
3576 module_param(reserved_rq_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
3577 MODULE_PARM_DESC(reserved_rq_based_ios
, "Reserved IOs in request-based mempools");
3579 module_param(use_blk_mq
, bool, S_IRUGO
| S_IWUSR
);
3580 MODULE_PARM_DESC(use_blk_mq
, "Use block multiqueue for request-based DM devices");
3582 MODULE_DESCRIPTION(DM_NAME
" driver");
3583 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3584 MODULE_LICENSE("GPL");