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
;
92 * For request-based dm - the bio clones we allocate are embedded in these
95 * We allocate these with bio_alloc_bioset, using the front_pad parameter when
96 * the bioset is created - this means the bio has to come at the end of the
99 struct dm_rq_clone_bio_info
{
101 struct dm_rq_target_io
*tio
;
105 union map_info
*dm_get_rq_mapinfo(struct request
*rq
)
107 if (rq
&& rq
->end_io_data
)
108 return &((struct dm_rq_target_io
*)rq
->end_io_data
)->info
;
111 EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo
);
113 #define MINOR_ALLOCED ((void *)-1)
116 * Bits for the md->flags field.
118 #define DMF_BLOCK_IO_FOR_SUSPEND 0
119 #define DMF_SUSPENDED 1
121 #define DMF_FREEING 3
122 #define DMF_DELETING 4
123 #define DMF_NOFLUSH_SUSPENDING 5
124 #define DMF_MERGE_IS_OPTIONAL 6
125 #define DMF_DEFERRED_REMOVE 7
126 #define DMF_SUSPENDED_INTERNALLY 8
129 * A dummy definition to make RCU happy.
130 * struct dm_table should never be dereferenced in this file.
137 * Work processed by per-device workqueue.
139 struct mapped_device
{
140 struct srcu_struct io_barrier
;
141 struct mutex suspend_lock
;
146 * The current mapping.
147 * Use dm_get_live_table{_fast} or take suspend_lock for
150 struct dm_table __rcu
*map
;
152 struct list_head table_devices
;
153 struct mutex table_devices_lock
;
157 struct request_queue
*queue
;
159 /* Protect queue and type against concurrent access. */
160 struct mutex type_lock
;
162 struct target_type
*immutable_target_type
;
164 struct gendisk
*disk
;
170 * A list of ios that arrived while we were suspended.
173 wait_queue_head_t wait
;
174 struct work_struct work
;
175 struct bio_list deferred
;
176 spinlock_t deferred_lock
;
179 * Processing queue (flush)
181 struct workqueue_struct
*wq
;
184 * io objects are allocated from here.
195 wait_queue_head_t eventq
;
197 struct list_head uevent_list
;
198 spinlock_t uevent_lock
; /* Protect access to uevent_list */
201 * freeze/thaw support require holding onto a super block
203 struct super_block
*frozen_sb
;
204 struct block_device
*bdev
;
206 /* forced geometry settings */
207 struct hd_geometry geometry
;
209 /* kobject and completion */
210 struct dm_kobject_holder kobj_holder
;
212 /* zero-length flush that will be cloned and submitted to targets */
213 struct bio flush_bio
;
215 /* the number of internal suspends */
216 unsigned internal_suspend_count
;
218 struct dm_stats stats
;
220 struct kthread_worker kworker
;
221 struct task_struct
*kworker_task
;
223 /* for request-based merge heuristic in dm_request_fn() */
224 unsigned seq_rq_merge_deadline_usecs
;
226 sector_t last_rq_pos
;
227 ktime_t last_rq_start_time
;
229 /* for blk-mq request-based DM support */
230 struct blk_mq_tag_set tag_set
;
234 * For mempools pre-allocation at the table loading time.
236 struct dm_md_mempools
{
242 struct table_device
{
243 struct list_head list
;
245 struct dm_dev dm_dev
;
248 #define RESERVED_BIO_BASED_IOS 16
249 #define RESERVED_REQUEST_BASED_IOS 256
250 #define RESERVED_MAX_IOS 1024
251 static struct kmem_cache
*_io_cache
;
252 static struct kmem_cache
*_rq_tio_cache
;
253 static struct kmem_cache
*_rq_cache
;
256 * Bio-based DM's mempools' reserved IOs set by the user.
258 static unsigned reserved_bio_based_ios
= RESERVED_BIO_BASED_IOS
;
261 * Request-based DM's mempools' reserved IOs set by the user.
263 static unsigned reserved_rq_based_ios
= RESERVED_REQUEST_BASED_IOS
;
265 static unsigned __dm_get_module_param(unsigned *module_param
,
266 unsigned def
, unsigned max
)
268 unsigned param
= ACCESS_ONCE(*module_param
);
269 unsigned modified_param
= 0;
272 modified_param
= def
;
273 else if (param
> max
)
274 modified_param
= max
;
276 if (modified_param
) {
277 (void)cmpxchg(module_param
, param
, modified_param
);
278 param
= modified_param
;
284 unsigned dm_get_reserved_bio_based_ios(void)
286 return __dm_get_module_param(&reserved_bio_based_ios
,
287 RESERVED_BIO_BASED_IOS
, RESERVED_MAX_IOS
);
289 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios
);
291 unsigned dm_get_reserved_rq_based_ios(void)
293 return __dm_get_module_param(&reserved_rq_based_ios
,
294 RESERVED_REQUEST_BASED_IOS
, RESERVED_MAX_IOS
);
296 EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios
);
298 static int __init
local_init(void)
302 /* allocate a slab for the dm_ios */
303 _io_cache
= KMEM_CACHE(dm_io
, 0);
307 _rq_tio_cache
= KMEM_CACHE(dm_rq_target_io
, 0);
309 goto out_free_io_cache
;
311 _rq_cache
= kmem_cache_create("dm_clone_request", sizeof(struct request
),
312 __alignof__(struct request
), 0, NULL
);
314 goto out_free_rq_tio_cache
;
316 r
= dm_uevent_init();
318 goto out_free_rq_cache
;
320 deferred_remove_workqueue
= alloc_workqueue("kdmremove", WQ_UNBOUND
, 1);
321 if (!deferred_remove_workqueue
) {
323 goto out_uevent_exit
;
327 r
= register_blkdev(_major
, _name
);
329 goto out_free_workqueue
;
337 destroy_workqueue(deferred_remove_workqueue
);
341 kmem_cache_destroy(_rq_cache
);
342 out_free_rq_tio_cache
:
343 kmem_cache_destroy(_rq_tio_cache
);
345 kmem_cache_destroy(_io_cache
);
350 static void local_exit(void)
352 flush_scheduled_work();
353 destroy_workqueue(deferred_remove_workqueue
);
355 kmem_cache_destroy(_rq_cache
);
356 kmem_cache_destroy(_rq_tio_cache
);
357 kmem_cache_destroy(_io_cache
);
358 unregister_blkdev(_major
, _name
);
363 DMINFO("cleaned up");
366 static int (*_inits
[])(void) __initdata
= {
377 static void (*_exits
[])(void) = {
388 static int __init
dm_init(void)
390 const int count
= ARRAY_SIZE(_inits
);
394 for (i
= 0; i
< count
; i
++) {
409 static void __exit
dm_exit(void)
411 int i
= ARRAY_SIZE(_exits
);
417 * Should be empty by this point.
419 idr_destroy(&_minor_idr
);
423 * Block device functions
425 int dm_deleting_md(struct mapped_device
*md
)
427 return test_bit(DMF_DELETING
, &md
->flags
);
430 static int dm_blk_open(struct block_device
*bdev
, fmode_t mode
)
432 struct mapped_device
*md
;
434 spin_lock(&_minor_lock
);
436 md
= bdev
->bd_disk
->private_data
;
440 if (test_bit(DMF_FREEING
, &md
->flags
) ||
441 dm_deleting_md(md
)) {
447 atomic_inc(&md
->open_count
);
449 spin_unlock(&_minor_lock
);
451 return md
? 0 : -ENXIO
;
454 static void dm_blk_close(struct gendisk
*disk
, fmode_t mode
)
456 struct mapped_device
*md
;
458 spin_lock(&_minor_lock
);
460 md
= disk
->private_data
;
464 if (atomic_dec_and_test(&md
->open_count
) &&
465 (test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
)))
466 queue_work(deferred_remove_workqueue
, &deferred_remove_work
);
470 spin_unlock(&_minor_lock
);
473 int dm_open_count(struct mapped_device
*md
)
475 return atomic_read(&md
->open_count
);
479 * Guarantees nothing is using the device before it's deleted.
481 int dm_lock_for_deletion(struct mapped_device
*md
, bool mark_deferred
, bool only_deferred
)
485 spin_lock(&_minor_lock
);
487 if (dm_open_count(md
)) {
490 set_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
491 } else if (only_deferred
&& !test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
))
494 set_bit(DMF_DELETING
, &md
->flags
);
496 spin_unlock(&_minor_lock
);
501 int dm_cancel_deferred_remove(struct mapped_device
*md
)
505 spin_lock(&_minor_lock
);
507 if (test_bit(DMF_DELETING
, &md
->flags
))
510 clear_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
512 spin_unlock(&_minor_lock
);
517 static void do_deferred_remove(struct work_struct
*w
)
519 dm_deferred_remove();
522 sector_t
dm_get_size(struct mapped_device
*md
)
524 return get_capacity(md
->disk
);
527 struct request_queue
*dm_get_md_queue(struct mapped_device
*md
)
532 struct dm_stats
*dm_get_stats(struct mapped_device
*md
)
537 static int dm_blk_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
539 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
541 return dm_get_geometry(md
, geo
);
544 static int dm_blk_ioctl(struct block_device
*bdev
, fmode_t mode
,
545 unsigned int cmd
, unsigned long arg
)
547 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
549 struct dm_table
*map
;
550 struct dm_target
*tgt
;
554 map
= dm_get_live_table(md
, &srcu_idx
);
556 if (!map
|| !dm_table_get_size(map
))
559 /* We only support devices that have a single target */
560 if (dm_table_get_num_targets(map
) != 1)
563 tgt
= dm_table_get_target(map
, 0);
564 if (!tgt
->type
->ioctl
)
567 if (dm_suspended_md(md
)) {
572 r
= tgt
->type
->ioctl(tgt
, cmd
, arg
);
575 dm_put_live_table(md
, srcu_idx
);
577 if (r
== -ENOTCONN
) {
585 static struct dm_io
*alloc_io(struct mapped_device
*md
)
587 return mempool_alloc(md
->io_pool
, GFP_NOIO
);
590 static void free_io(struct mapped_device
*md
, struct dm_io
*io
)
592 mempool_free(io
, md
->io_pool
);
595 static void free_tio(struct mapped_device
*md
, struct dm_target_io
*tio
)
597 bio_put(&tio
->clone
);
600 static struct dm_rq_target_io
*alloc_rq_tio(struct mapped_device
*md
,
603 return mempool_alloc(md
->io_pool
, gfp_mask
);
606 static void free_rq_tio(struct dm_rq_target_io
*tio
)
608 mempool_free(tio
, tio
->md
->io_pool
);
611 static struct request
*alloc_clone_request(struct mapped_device
*md
,
614 return mempool_alloc(md
->rq_pool
, gfp_mask
);
617 static void free_clone_request(struct mapped_device
*md
, struct request
*rq
)
619 mempool_free(rq
, md
->rq_pool
);
622 static int md_in_flight(struct mapped_device
*md
)
624 return atomic_read(&md
->pending
[READ
]) +
625 atomic_read(&md
->pending
[WRITE
]);
628 static void start_io_acct(struct dm_io
*io
)
630 struct mapped_device
*md
= io
->md
;
631 struct bio
*bio
= io
->bio
;
633 int rw
= bio_data_dir(bio
);
635 io
->start_time
= jiffies
;
637 cpu
= part_stat_lock();
638 part_round_stats(cpu
, &dm_disk(md
)->part0
);
640 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
],
641 atomic_inc_return(&md
->pending
[rw
]));
643 if (unlikely(dm_stats_used(&md
->stats
)))
644 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
645 bio_sectors(bio
), false, 0, &io
->stats_aux
);
648 static void end_io_acct(struct dm_io
*io
)
650 struct mapped_device
*md
= io
->md
;
651 struct bio
*bio
= io
->bio
;
652 unsigned long duration
= jiffies
- io
->start_time
;
654 int rw
= bio_data_dir(bio
);
656 generic_end_io_acct(rw
, &dm_disk(md
)->part0
, io
->start_time
);
658 if (unlikely(dm_stats_used(&md
->stats
)))
659 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
660 bio_sectors(bio
), true, duration
, &io
->stats_aux
);
663 * After this is decremented the bio must not be touched if it is
666 pending
= atomic_dec_return(&md
->pending
[rw
]);
667 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
], pending
);
668 pending
+= atomic_read(&md
->pending
[rw
^0x1]);
670 /* nudge anyone waiting on suspend queue */
676 * Add the bio to the list of deferred io.
678 static void queue_io(struct mapped_device
*md
, struct bio
*bio
)
682 spin_lock_irqsave(&md
->deferred_lock
, flags
);
683 bio_list_add(&md
->deferred
, bio
);
684 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
685 queue_work(md
->wq
, &md
->work
);
689 * Everyone (including functions in this file), should use this
690 * function to access the md->map field, and make sure they call
691 * dm_put_live_table() when finished.
693 struct dm_table
*dm_get_live_table(struct mapped_device
*md
, int *srcu_idx
) __acquires(md
->io_barrier
)
695 *srcu_idx
= srcu_read_lock(&md
->io_barrier
);
697 return srcu_dereference(md
->map
, &md
->io_barrier
);
700 void dm_put_live_table(struct mapped_device
*md
, int srcu_idx
) __releases(md
->io_barrier
)
702 srcu_read_unlock(&md
->io_barrier
, srcu_idx
);
705 void dm_sync_table(struct mapped_device
*md
)
707 synchronize_srcu(&md
->io_barrier
);
708 synchronize_rcu_expedited();
712 * A fast alternative to dm_get_live_table/dm_put_live_table.
713 * The caller must not block between these two functions.
715 static struct dm_table
*dm_get_live_table_fast(struct mapped_device
*md
) __acquires(RCU
)
718 return rcu_dereference(md
->map
);
721 static void dm_put_live_table_fast(struct mapped_device
*md
) __releases(RCU
)
727 * Open a table device so we can use it as a map destination.
729 static int open_table_device(struct table_device
*td
, dev_t dev
,
730 struct mapped_device
*md
)
732 static char *_claim_ptr
= "I belong to device-mapper";
733 struct block_device
*bdev
;
737 BUG_ON(td
->dm_dev
.bdev
);
739 bdev
= blkdev_get_by_dev(dev
, td
->dm_dev
.mode
| FMODE_EXCL
, _claim_ptr
);
741 return PTR_ERR(bdev
);
743 r
= bd_link_disk_holder(bdev
, dm_disk(md
));
745 blkdev_put(bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
749 td
->dm_dev
.bdev
= bdev
;
754 * Close a table device that we've been using.
756 static void close_table_device(struct table_device
*td
, struct mapped_device
*md
)
758 if (!td
->dm_dev
.bdev
)
761 bd_unlink_disk_holder(td
->dm_dev
.bdev
, dm_disk(md
));
762 blkdev_put(td
->dm_dev
.bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
763 td
->dm_dev
.bdev
= NULL
;
766 static struct table_device
*find_table_device(struct list_head
*l
, dev_t dev
,
768 struct table_device
*td
;
770 list_for_each_entry(td
, l
, list
)
771 if (td
->dm_dev
.bdev
->bd_dev
== dev
&& td
->dm_dev
.mode
== mode
)
777 int dm_get_table_device(struct mapped_device
*md
, dev_t dev
, fmode_t mode
,
778 struct dm_dev
**result
) {
780 struct table_device
*td
;
782 mutex_lock(&md
->table_devices_lock
);
783 td
= find_table_device(&md
->table_devices
, dev
, mode
);
785 td
= kmalloc(sizeof(*td
), GFP_KERNEL
);
787 mutex_unlock(&md
->table_devices_lock
);
791 td
->dm_dev
.mode
= mode
;
792 td
->dm_dev
.bdev
= NULL
;
794 if ((r
= open_table_device(td
, dev
, md
))) {
795 mutex_unlock(&md
->table_devices_lock
);
800 format_dev_t(td
->dm_dev
.name
, dev
);
802 atomic_set(&td
->count
, 0);
803 list_add(&td
->list
, &md
->table_devices
);
805 atomic_inc(&td
->count
);
806 mutex_unlock(&md
->table_devices_lock
);
808 *result
= &td
->dm_dev
;
811 EXPORT_SYMBOL_GPL(dm_get_table_device
);
813 void dm_put_table_device(struct mapped_device
*md
, struct dm_dev
*d
)
815 struct table_device
*td
= container_of(d
, struct table_device
, dm_dev
);
817 mutex_lock(&md
->table_devices_lock
);
818 if (atomic_dec_and_test(&td
->count
)) {
819 close_table_device(td
, md
);
823 mutex_unlock(&md
->table_devices_lock
);
825 EXPORT_SYMBOL(dm_put_table_device
);
827 static void free_table_devices(struct list_head
*devices
)
829 struct list_head
*tmp
, *next
;
831 list_for_each_safe(tmp
, next
, devices
) {
832 struct table_device
*td
= list_entry(tmp
, struct table_device
, list
);
834 DMWARN("dm_destroy: %s still exists with %d references",
835 td
->dm_dev
.name
, atomic_read(&td
->count
));
841 * Get the geometry associated with a dm device
843 int dm_get_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
851 * Set the geometry of a device.
853 int dm_set_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
855 sector_t sz
= (sector_t
)geo
->cylinders
* geo
->heads
* geo
->sectors
;
857 if (geo
->start
> sz
) {
858 DMWARN("Start sector is beyond the geometry limits.");
867 /*-----------------------------------------------------------------
869 * A more elegant soln is in the works that uses the queue
870 * merge fn, unfortunately there are a couple of changes to
871 * the block layer that I want to make for this. So in the
872 * interests of getting something for people to use I give
873 * you this clearly demarcated crap.
874 *---------------------------------------------------------------*/
876 static int __noflush_suspending(struct mapped_device
*md
)
878 return test_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
882 * Decrements the number of outstanding ios that a bio has been
883 * cloned into, completing the original io if necc.
885 static void dec_pending(struct dm_io
*io
, int error
)
890 struct mapped_device
*md
= io
->md
;
892 /* Push-back supersedes any I/O errors */
893 if (unlikely(error
)) {
894 spin_lock_irqsave(&io
->endio_lock
, flags
);
895 if (!(io
->error
> 0 && __noflush_suspending(md
)))
897 spin_unlock_irqrestore(&io
->endio_lock
, flags
);
900 if (atomic_dec_and_test(&io
->io_count
)) {
901 if (io
->error
== DM_ENDIO_REQUEUE
) {
903 * Target requested pushing back the I/O.
905 spin_lock_irqsave(&md
->deferred_lock
, flags
);
906 if (__noflush_suspending(md
))
907 bio_list_add_head(&md
->deferred
, io
->bio
);
909 /* noflush suspend was interrupted. */
911 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
914 io_error
= io
->error
;
919 if (io_error
== DM_ENDIO_REQUEUE
)
922 if ((bio
->bi_rw
& REQ_FLUSH
) && bio
->bi_iter
.bi_size
) {
924 * Preflush done for flush with data, reissue
927 bio
->bi_rw
&= ~REQ_FLUSH
;
930 /* done with normal IO or empty flush */
931 trace_block_bio_complete(md
->queue
, bio
, io_error
);
932 bio_endio(bio
, io_error
);
937 static void disable_write_same(struct mapped_device
*md
)
939 struct queue_limits
*limits
= dm_get_queue_limits(md
);
941 /* device doesn't really support WRITE SAME, disable it */
942 limits
->max_write_same_sectors
= 0;
945 static void clone_endio(struct bio
*bio
, int error
)
948 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
949 struct dm_io
*io
= tio
->io
;
950 struct mapped_device
*md
= tio
->io
->md
;
951 dm_endio_fn endio
= tio
->ti
->type
->end_io
;
953 if (!bio_flagged(bio
, BIO_UPTODATE
) && !error
)
957 r
= endio(tio
->ti
, bio
, error
);
958 if (r
< 0 || r
== DM_ENDIO_REQUEUE
)
960 * error and requeue request are handled
964 else if (r
== DM_ENDIO_INCOMPLETE
)
965 /* The target will handle the io */
968 DMWARN("unimplemented target endio return value: %d", r
);
973 if (unlikely(r
== -EREMOTEIO
&& (bio
->bi_rw
& REQ_WRITE_SAME
) &&
974 !bdev_get_queue(bio
->bi_bdev
)->limits
.max_write_same_sectors
))
975 disable_write_same(md
);
978 dec_pending(io
, error
);
982 * Partial completion handling for request-based dm
984 static void end_clone_bio(struct bio
*clone
, int error
)
986 struct dm_rq_clone_bio_info
*info
=
987 container_of(clone
, struct dm_rq_clone_bio_info
, clone
);
988 struct dm_rq_target_io
*tio
= info
->tio
;
989 struct bio
*bio
= info
->orig
;
990 unsigned int nr_bytes
= info
->orig
->bi_iter
.bi_size
;
996 * An error has already been detected on the request.
997 * Once error occurred, just let clone->end_io() handle
1003 * Don't notice the error to the upper layer yet.
1004 * The error handling decision is made by the target driver,
1005 * when the request is completed.
1012 * I/O for the bio successfully completed.
1013 * Notice the data completion to the upper layer.
1017 * bios are processed from the head of the list.
1018 * So the completing bio should always be rq->bio.
1019 * If it's not, something wrong is happening.
1021 if (tio
->orig
->bio
!= bio
)
1022 DMERR("bio completion is going in the middle of the request");
1025 * Update the original request.
1026 * Do not use blk_end_request() here, because it may complete
1027 * the original request before the clone, and break the ordering.
1029 blk_update_request(tio
->orig
, 0, nr_bytes
);
1032 static struct dm_rq_target_io
*tio_from_request(struct request
*rq
)
1034 return (rq
->q
->mq_ops
? blk_mq_rq_to_pdu(rq
) : rq
->special
);
1038 * Don't touch any member of the md after calling this function because
1039 * the md may be freed in dm_put() at the end of this function.
1040 * Or do dm_get() before calling this function and dm_put() later.
1042 static void rq_completed(struct mapped_device
*md
, int rw
, bool run_queue
)
1044 int nr_requests_pending
;
1046 atomic_dec(&md
->pending
[rw
]);
1048 /* nudge anyone waiting on suspend queue */
1049 nr_requests_pending
= md_in_flight(md
);
1050 if (!nr_requests_pending
)
1054 * Run this off this callpath, as drivers could invoke end_io while
1055 * inside their request_fn (and holding the queue lock). Calling
1056 * back into ->request_fn() could deadlock attempting to grab the
1060 if (md
->queue
->mq_ops
)
1061 blk_mq_run_hw_queues(md
->queue
, true);
1062 else if (!nr_requests_pending
||
1063 (nr_requests_pending
>= md
->queue
->nr_congestion_on
))
1064 blk_run_queue_async(md
->queue
);
1068 * dm_put() must be at the end of this function. See the comment above
1073 static void free_rq_clone(struct request
*clone
)
1075 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1076 struct mapped_device
*md
= tio
->md
;
1078 blk_rq_unprep_clone(clone
);
1080 if (clone
->q
->mq_ops
)
1081 tio
->ti
->type
->release_clone_rq(clone
);
1082 else if (!md
->queue
->mq_ops
)
1083 /* request_fn queue stacked on request_fn queue(s) */
1084 free_clone_request(md
, clone
);
1086 if (!md
->queue
->mq_ops
)
1091 * Complete the clone and the original request.
1092 * Must be called without clone's queue lock held,
1093 * see end_clone_request() for more details.
1095 static void dm_end_request(struct request
*clone
, int error
)
1097 int rw
= rq_data_dir(clone
);
1098 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1099 struct mapped_device
*md
= tio
->md
;
1100 struct request
*rq
= tio
->orig
;
1102 if (rq
->cmd_type
== REQ_TYPE_BLOCK_PC
) {
1103 rq
->errors
= clone
->errors
;
1104 rq
->resid_len
= clone
->resid_len
;
1108 * We are using the sense buffer of the original
1110 * So setting the length of the sense data is enough.
1112 rq
->sense_len
= clone
->sense_len
;
1115 free_rq_clone(clone
);
1117 blk_end_request_all(rq
, error
);
1119 blk_mq_end_request(rq
, error
);
1120 rq_completed(md
, rw
, true);
1123 static void dm_unprep_request(struct request
*rq
)
1125 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
1126 struct request
*clone
= tio
->clone
;
1128 if (!rq
->q
->mq_ops
) {
1130 rq
->cmd_flags
&= ~REQ_DONTPREP
;
1134 free_rq_clone(clone
);
1138 * Requeue the original request of a clone.
1140 static void old_requeue_request(struct request
*rq
)
1142 struct request_queue
*q
= rq
->q
;
1143 unsigned long flags
;
1145 spin_lock_irqsave(q
->queue_lock
, flags
);
1146 blk_requeue_request(q
, rq
);
1147 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1150 static void dm_requeue_unmapped_original_request(struct mapped_device
*md
,
1153 int rw
= rq_data_dir(rq
);
1155 dm_unprep_request(rq
);
1158 old_requeue_request(rq
);
1160 blk_mq_requeue_request(rq
);
1161 blk_mq_kick_requeue_list(rq
->q
);
1164 rq_completed(md
, rw
, false);
1167 static void dm_requeue_unmapped_request(struct request
*clone
)
1169 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1171 dm_requeue_unmapped_original_request(tio
->md
, tio
->orig
);
1174 static void old_stop_queue(struct request_queue
*q
)
1176 unsigned long flags
;
1178 if (blk_queue_stopped(q
))
1181 spin_lock_irqsave(q
->queue_lock
, flags
);
1183 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1186 static void stop_queue(struct request_queue
*q
)
1191 blk_mq_stop_hw_queues(q
);
1194 static void old_start_queue(struct request_queue
*q
)
1196 unsigned long flags
;
1198 spin_lock_irqsave(q
->queue_lock
, flags
);
1199 if (blk_queue_stopped(q
))
1201 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1204 static void start_queue(struct request_queue
*q
)
1209 blk_mq_start_stopped_hw_queues(q
, true);
1212 static void dm_done(struct request
*clone
, int error
, bool mapped
)
1215 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1216 dm_request_endio_fn rq_end_io
= NULL
;
1219 rq_end_io
= tio
->ti
->type
->rq_end_io
;
1221 if (mapped
&& rq_end_io
)
1222 r
= rq_end_io(tio
->ti
, clone
, error
, &tio
->info
);
1225 if (unlikely(r
== -EREMOTEIO
&& (clone
->cmd_flags
& REQ_WRITE_SAME
) &&
1226 !clone
->q
->limits
.max_write_same_sectors
))
1227 disable_write_same(tio
->md
);
1230 /* The target wants to complete the I/O */
1231 dm_end_request(clone
, r
);
1232 else if (r
== DM_ENDIO_INCOMPLETE
)
1233 /* The target will handle the I/O */
1235 else if (r
== DM_ENDIO_REQUEUE
)
1236 /* The target wants to requeue the I/O */
1237 dm_requeue_unmapped_request(clone
);
1239 DMWARN("unimplemented target endio return value: %d", r
);
1245 * Request completion handler for request-based dm
1247 static void dm_softirq_done(struct request
*rq
)
1250 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
1251 struct request
*clone
= tio
->clone
;
1255 rw
= rq_data_dir(rq
);
1256 if (!rq
->q
->mq_ops
) {
1257 blk_end_request_all(rq
, tio
->error
);
1258 rq_completed(tio
->md
, rw
, false);
1261 blk_mq_end_request(rq
, tio
->error
);
1262 rq_completed(tio
->md
, rw
, false);
1267 if (rq
->cmd_flags
& REQ_FAILED
)
1270 dm_done(clone
, tio
->error
, mapped
);
1274 * Complete the clone and the original request with the error status
1275 * through softirq context.
1277 static void dm_complete_request(struct request
*rq
, int error
)
1279 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
1282 blk_complete_request(rq
);
1286 * Complete the not-mapped clone and the original request with the error status
1287 * through softirq context.
1288 * Target's rq_end_io() function isn't called.
1289 * This may be used when the target's map_rq() or clone_and_map_rq() functions fail.
1291 static void dm_kill_unmapped_request(struct request
*rq
, int error
)
1293 rq
->cmd_flags
|= REQ_FAILED
;
1294 dm_complete_request(rq
, error
);
1298 * Called with the clone's queue lock held (for non-blk-mq)
1300 static void end_clone_request(struct request
*clone
, int error
)
1302 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1304 if (!clone
->q
->mq_ops
) {
1306 * For just cleaning up the information of the queue in which
1307 * the clone was dispatched.
1308 * The clone is *NOT* freed actually here because it is alloced
1309 * from dm own mempool (REQ_ALLOCED isn't set).
1311 __blk_put_request(clone
->q
, clone
);
1315 * Actual request completion is done in a softirq context which doesn't
1316 * hold the clone's queue lock. Otherwise, deadlock could occur because:
1317 * - another request may be submitted by the upper level driver
1318 * of the stacking during the completion
1319 * - the submission which requires queue lock may be done
1320 * against this clone's queue
1322 dm_complete_request(tio
->orig
, error
);
1326 * Return maximum size of I/O possible at the supplied sector up to the current
1329 static sector_t
max_io_len_target_boundary(sector_t sector
, struct dm_target
*ti
)
1331 sector_t target_offset
= dm_target_offset(ti
, sector
);
1333 return ti
->len
- target_offset
;
1336 static sector_t
max_io_len(sector_t sector
, struct dm_target
*ti
)
1338 sector_t len
= max_io_len_target_boundary(sector
, ti
);
1339 sector_t offset
, max_len
;
1342 * Does the target need to split even further?
1344 if (ti
->max_io_len
) {
1345 offset
= dm_target_offset(ti
, sector
);
1346 if (unlikely(ti
->max_io_len
& (ti
->max_io_len
- 1)))
1347 max_len
= sector_div(offset
, ti
->max_io_len
);
1349 max_len
= offset
& (ti
->max_io_len
- 1);
1350 max_len
= ti
->max_io_len
- max_len
;
1359 int dm_set_target_max_io_len(struct dm_target
*ti
, sector_t len
)
1361 if (len
> UINT_MAX
) {
1362 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1363 (unsigned long long)len
, UINT_MAX
);
1364 ti
->error
= "Maximum size of target IO is too large";
1368 ti
->max_io_len
= (uint32_t) len
;
1372 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len
);
1375 * A target may call dm_accept_partial_bio only from the map routine. It is
1376 * allowed for all bio types except REQ_FLUSH.
1378 * dm_accept_partial_bio informs the dm that the target only wants to process
1379 * additional n_sectors sectors of the bio and the rest of the data should be
1380 * sent in a next bio.
1382 * A diagram that explains the arithmetics:
1383 * +--------------------+---------------+-------+
1385 * +--------------------+---------------+-------+
1387 * <-------------- *tio->len_ptr --------------->
1388 * <------- bi_size ------->
1391 * Region 1 was already iterated over with bio_advance or similar function.
1392 * (it may be empty if the target doesn't use bio_advance)
1393 * Region 2 is the remaining bio size that the target wants to process.
1394 * (it may be empty if region 1 is non-empty, although there is no reason
1396 * The target requires that region 3 is to be sent in the next bio.
1398 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1399 * the partially processed part (the sum of regions 1+2) must be the same for all
1400 * copies of the bio.
1402 void dm_accept_partial_bio(struct bio
*bio
, unsigned n_sectors
)
1404 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
1405 unsigned bi_size
= bio
->bi_iter
.bi_size
>> SECTOR_SHIFT
;
1406 BUG_ON(bio
->bi_rw
& REQ_FLUSH
);
1407 BUG_ON(bi_size
> *tio
->len_ptr
);
1408 BUG_ON(n_sectors
> bi_size
);
1409 *tio
->len_ptr
-= bi_size
- n_sectors
;
1410 bio
->bi_iter
.bi_size
= n_sectors
<< SECTOR_SHIFT
;
1412 EXPORT_SYMBOL_GPL(dm_accept_partial_bio
);
1414 static void __map_bio(struct dm_target_io
*tio
)
1418 struct mapped_device
*md
;
1419 struct bio
*clone
= &tio
->clone
;
1420 struct dm_target
*ti
= tio
->ti
;
1422 clone
->bi_end_io
= clone_endio
;
1425 * Map the clone. If r == 0 we don't need to do
1426 * anything, the target has assumed ownership of
1429 atomic_inc(&tio
->io
->io_count
);
1430 sector
= clone
->bi_iter
.bi_sector
;
1431 r
= ti
->type
->map(ti
, clone
);
1432 if (r
== DM_MAPIO_REMAPPED
) {
1433 /* the bio has been remapped so dispatch it */
1435 trace_block_bio_remap(bdev_get_queue(clone
->bi_bdev
), clone
,
1436 tio
->io
->bio
->bi_bdev
->bd_dev
, sector
);
1438 generic_make_request(clone
);
1439 } else if (r
< 0 || r
== DM_MAPIO_REQUEUE
) {
1440 /* error the io and bail out, or requeue it if needed */
1442 dec_pending(tio
->io
, r
);
1445 DMWARN("unimplemented target map return value: %d", r
);
1451 struct mapped_device
*md
;
1452 struct dm_table
*map
;
1456 unsigned sector_count
;
1459 static void bio_setup_sector(struct bio
*bio
, sector_t sector
, unsigned len
)
1461 bio
->bi_iter
.bi_sector
= sector
;
1462 bio
->bi_iter
.bi_size
= to_bytes(len
);
1466 * Creates a bio that consists of range of complete bvecs.
1468 static void clone_bio(struct dm_target_io
*tio
, struct bio
*bio
,
1469 sector_t sector
, unsigned len
)
1471 struct bio
*clone
= &tio
->clone
;
1473 __bio_clone_fast(clone
, bio
);
1475 if (bio_integrity(bio
))
1476 bio_integrity_clone(clone
, bio
, GFP_NOIO
);
1478 bio_advance(clone
, to_bytes(sector
- clone
->bi_iter
.bi_sector
));
1479 clone
->bi_iter
.bi_size
= to_bytes(len
);
1481 if (bio_integrity(bio
))
1482 bio_integrity_trim(clone
, 0, len
);
1485 static struct dm_target_io
*alloc_tio(struct clone_info
*ci
,
1486 struct dm_target
*ti
,
1487 unsigned target_bio_nr
)
1489 struct dm_target_io
*tio
;
1492 clone
= bio_alloc_bioset(GFP_NOIO
, 0, ci
->md
->bs
);
1493 tio
= container_of(clone
, struct dm_target_io
, clone
);
1497 tio
->target_bio_nr
= target_bio_nr
;
1502 static void __clone_and_map_simple_bio(struct clone_info
*ci
,
1503 struct dm_target
*ti
,
1504 unsigned target_bio_nr
, unsigned *len
)
1506 struct dm_target_io
*tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1507 struct bio
*clone
= &tio
->clone
;
1511 __bio_clone_fast(clone
, ci
->bio
);
1513 bio_setup_sector(clone
, ci
->sector
, *len
);
1518 static void __send_duplicate_bios(struct clone_info
*ci
, struct dm_target
*ti
,
1519 unsigned num_bios
, unsigned *len
)
1521 unsigned target_bio_nr
;
1523 for (target_bio_nr
= 0; target_bio_nr
< num_bios
; target_bio_nr
++)
1524 __clone_and_map_simple_bio(ci
, ti
, target_bio_nr
, len
);
1527 static int __send_empty_flush(struct clone_info
*ci
)
1529 unsigned target_nr
= 0;
1530 struct dm_target
*ti
;
1532 BUG_ON(bio_has_data(ci
->bio
));
1533 while ((ti
= dm_table_get_target(ci
->map
, target_nr
++)))
1534 __send_duplicate_bios(ci
, ti
, ti
->num_flush_bios
, NULL
);
1539 static void __clone_and_map_data_bio(struct clone_info
*ci
, struct dm_target
*ti
,
1540 sector_t sector
, unsigned *len
)
1542 struct bio
*bio
= ci
->bio
;
1543 struct dm_target_io
*tio
;
1544 unsigned target_bio_nr
;
1545 unsigned num_target_bios
= 1;
1548 * Does the target want to receive duplicate copies of the bio?
1550 if (bio_data_dir(bio
) == WRITE
&& ti
->num_write_bios
)
1551 num_target_bios
= ti
->num_write_bios(ti
, bio
);
1553 for (target_bio_nr
= 0; target_bio_nr
< num_target_bios
; target_bio_nr
++) {
1554 tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1556 clone_bio(tio
, bio
, sector
, *len
);
1561 typedef unsigned (*get_num_bios_fn
)(struct dm_target
*ti
);
1563 static unsigned get_num_discard_bios(struct dm_target
*ti
)
1565 return ti
->num_discard_bios
;
1568 static unsigned get_num_write_same_bios(struct dm_target
*ti
)
1570 return ti
->num_write_same_bios
;
1573 typedef bool (*is_split_required_fn
)(struct dm_target
*ti
);
1575 static bool is_split_required_for_discard(struct dm_target
*ti
)
1577 return ti
->split_discard_bios
;
1580 static int __send_changing_extent_only(struct clone_info
*ci
,
1581 get_num_bios_fn get_num_bios
,
1582 is_split_required_fn is_split_required
)
1584 struct dm_target
*ti
;
1589 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1590 if (!dm_target_is_valid(ti
))
1594 * Even though the device advertised support for this type of
1595 * request, that does not mean every target supports it, and
1596 * reconfiguration might also have changed that since the
1597 * check was performed.
1599 num_bios
= get_num_bios
? get_num_bios(ti
) : 0;
1603 if (is_split_required
&& !is_split_required(ti
))
1604 len
= min((sector_t
)ci
->sector_count
, max_io_len_target_boundary(ci
->sector
, ti
));
1606 len
= min((sector_t
)ci
->sector_count
, max_io_len(ci
->sector
, ti
));
1608 __send_duplicate_bios(ci
, ti
, num_bios
, &len
);
1611 } while (ci
->sector_count
-= len
);
1616 static int __send_discard(struct clone_info
*ci
)
1618 return __send_changing_extent_only(ci
, get_num_discard_bios
,
1619 is_split_required_for_discard
);
1622 static int __send_write_same(struct clone_info
*ci
)
1624 return __send_changing_extent_only(ci
, get_num_write_same_bios
, NULL
);
1628 * Select the correct strategy for processing a non-flush bio.
1630 static int __split_and_process_non_flush(struct clone_info
*ci
)
1632 struct bio
*bio
= ci
->bio
;
1633 struct dm_target
*ti
;
1636 if (unlikely(bio
->bi_rw
& REQ_DISCARD
))
1637 return __send_discard(ci
);
1638 else if (unlikely(bio
->bi_rw
& REQ_WRITE_SAME
))
1639 return __send_write_same(ci
);
1641 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1642 if (!dm_target_is_valid(ti
))
1645 len
= min_t(sector_t
, max_io_len(ci
->sector
, ti
), ci
->sector_count
);
1647 __clone_and_map_data_bio(ci
, ti
, ci
->sector
, &len
);
1650 ci
->sector_count
-= len
;
1656 * Entry point to split a bio into clones and submit them to the targets.
1658 static void __split_and_process_bio(struct mapped_device
*md
,
1659 struct dm_table
*map
, struct bio
*bio
)
1661 struct clone_info ci
;
1664 if (unlikely(!map
)) {
1671 ci
.io
= alloc_io(md
);
1673 atomic_set(&ci
.io
->io_count
, 1);
1676 spin_lock_init(&ci
.io
->endio_lock
);
1677 ci
.sector
= bio
->bi_iter
.bi_sector
;
1679 start_io_acct(ci
.io
);
1681 if (bio
->bi_rw
& REQ_FLUSH
) {
1682 ci
.bio
= &ci
.md
->flush_bio
;
1683 ci
.sector_count
= 0;
1684 error
= __send_empty_flush(&ci
);
1685 /* dec_pending submits any data associated with flush */
1688 ci
.sector_count
= bio_sectors(bio
);
1689 while (ci
.sector_count
&& !error
)
1690 error
= __split_and_process_non_flush(&ci
);
1693 /* drop the extra reference count */
1694 dec_pending(ci
.io
, error
);
1696 /*-----------------------------------------------------------------
1698 *---------------------------------------------------------------*/
1700 static int dm_merge_bvec(struct request_queue
*q
,
1701 struct bvec_merge_data
*bvm
,
1702 struct bio_vec
*biovec
)
1704 struct mapped_device
*md
= q
->queuedata
;
1705 struct dm_table
*map
= dm_get_live_table_fast(md
);
1706 struct dm_target
*ti
;
1707 sector_t max_sectors
;
1713 ti
= dm_table_find_target(map
, bvm
->bi_sector
);
1714 if (!dm_target_is_valid(ti
))
1718 * Find maximum amount of I/O that won't need splitting
1720 max_sectors
= min(max_io_len(bvm
->bi_sector
, ti
),
1721 (sector_t
) queue_max_sectors(q
));
1722 max_size
= (max_sectors
<< SECTOR_SHIFT
) - bvm
->bi_size
;
1723 if (unlikely(max_size
< 0)) /* this shouldn't _ever_ happen */
1727 * merge_bvec_fn() returns number of bytes
1728 * it can accept at this offset
1729 * max is precomputed maximal io size
1731 if (max_size
&& ti
->type
->merge
)
1732 max_size
= ti
->type
->merge(ti
, bvm
, biovec
, max_size
);
1734 * If the target doesn't support merge method and some of the devices
1735 * provided their merge_bvec method (we know this by looking for the
1736 * max_hw_sectors that dm_set_device_limits may set), then we can't
1737 * allow bios with multiple vector entries. So always set max_size
1738 * to 0, and the code below allows just one page.
1740 else if (queue_max_hw_sectors(q
) <= PAGE_SIZE
>> 9)
1744 dm_put_live_table_fast(md
);
1746 * Always allow an entire first page
1748 if (max_size
<= biovec
->bv_len
&& !(bvm
->bi_size
>> SECTOR_SHIFT
))
1749 max_size
= biovec
->bv_len
;
1755 * The request function that just remaps the bio built up by
1758 static void dm_make_request(struct request_queue
*q
, struct bio
*bio
)
1760 int rw
= bio_data_dir(bio
);
1761 struct mapped_device
*md
= q
->queuedata
;
1763 struct dm_table
*map
;
1765 map
= dm_get_live_table(md
, &srcu_idx
);
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
);
1955 return DM_MAPIO_REQUEUE
;
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_unmapped_request(clone
);
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_unmapped_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();
2016 * Hold the md reference here for the in-flight I/O.
2017 * We can't rely on the reference count by device opener,
2018 * because the device may be closed during the request completion
2019 * when all bios are completed.
2020 * See the comment in rq_completed() too.
2025 #define MAX_SEQ_RQ_MERGE_DEADLINE_USECS 100000
2027 ssize_t
dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device
*md
, char *buf
)
2029 return sprintf(buf
, "%u\n", md
->seq_rq_merge_deadline_usecs
);
2032 ssize_t
dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device
*md
,
2033 const char *buf
, size_t count
)
2037 if (!dm_request_based(md
))
2040 if (kstrtouint(buf
, 10, &deadline
))
2043 if (deadline
> MAX_SEQ_RQ_MERGE_DEADLINE_USECS
)
2044 deadline
= MAX_SEQ_RQ_MERGE_DEADLINE_USECS
;
2046 md
->seq_rq_merge_deadline_usecs
= deadline
;
2051 static bool dm_request_peeked_before_merge_deadline(struct mapped_device
*md
)
2053 ktime_t kt_deadline
;
2055 if (!md
->seq_rq_merge_deadline_usecs
)
2058 kt_deadline
= ns_to_ktime((u64
)md
->seq_rq_merge_deadline_usecs
* NSEC_PER_USEC
);
2059 kt_deadline
= ktime_add_safe(md
->last_rq_start_time
, kt_deadline
);
2061 return !ktime_after(ktime_get(), kt_deadline
);
2065 * q->request_fn for request-based dm.
2066 * Called with the queue lock held.
2068 static void dm_request_fn(struct request_queue
*q
)
2070 struct mapped_device
*md
= q
->queuedata
;
2072 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
2073 struct dm_target
*ti
;
2075 struct dm_rq_target_io
*tio
;
2079 * For suspend, check blk_queue_stopped() and increment
2080 * ->pending within a single queue_lock not to increment the
2081 * number of in-flight I/Os after the queue is stopped in
2084 while (!blk_queue_stopped(q
)) {
2085 rq
= blk_peek_request(q
);
2089 /* always use block 0 to find the target for flushes for now */
2091 if (!(rq
->cmd_flags
& REQ_FLUSH
))
2092 pos
= blk_rq_pos(rq
);
2094 ti
= dm_table_find_target(map
, pos
);
2095 if (!dm_target_is_valid(ti
)) {
2097 * Must perform setup, that rq_completed() requires,
2098 * before calling dm_kill_unmapped_request
2100 DMERR_LIMIT("request attempted access beyond the end of device");
2101 dm_start_request(md
, rq
);
2102 dm_kill_unmapped_request(rq
, -EIO
);
2106 if (dm_request_peeked_before_merge_deadline(md
) &&
2107 md_in_flight(md
) && rq
->bio
&& rq
->bio
->bi_vcnt
== 1 &&
2108 md
->last_rq_pos
== pos
&& md
->last_rq_rw
== rq_data_dir(rq
))
2111 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
2114 dm_start_request(md
, rq
);
2116 tio
= tio_from_request(rq
);
2117 /* Establish tio->ti before queuing work (map_tio_request) */
2119 queue_kthread_work(&md
->kworker
, &tio
->work
);
2120 BUG_ON(!irqs_disabled());
2126 blk_delay_queue(q
, HZ
/ 100);
2128 dm_put_live_table(md
, srcu_idx
);
2131 static int dm_any_congested(void *congested_data
, int bdi_bits
)
2134 struct mapped_device
*md
= congested_data
;
2135 struct dm_table
*map
;
2137 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
2138 map
= dm_get_live_table_fast(md
);
2141 * Request-based dm cares about only own queue for
2142 * the query about congestion status of request_queue
2144 if (dm_request_based(md
))
2145 r
= md
->queue
->backing_dev_info
.state
&
2148 r
= dm_table_any_congested(map
, bdi_bits
);
2150 dm_put_live_table_fast(md
);
2156 /*-----------------------------------------------------------------
2157 * An IDR is used to keep track of allocated minor numbers.
2158 *---------------------------------------------------------------*/
2159 static void free_minor(int minor
)
2161 spin_lock(&_minor_lock
);
2162 idr_remove(&_minor_idr
, minor
);
2163 spin_unlock(&_minor_lock
);
2167 * See if the device with a specific minor # is free.
2169 static int specific_minor(int minor
)
2173 if (minor
>= (1 << MINORBITS
))
2176 idr_preload(GFP_KERNEL
);
2177 spin_lock(&_minor_lock
);
2179 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, minor
, minor
+ 1, GFP_NOWAIT
);
2181 spin_unlock(&_minor_lock
);
2184 return r
== -ENOSPC
? -EBUSY
: r
;
2188 static int next_free_minor(int *minor
)
2192 idr_preload(GFP_KERNEL
);
2193 spin_lock(&_minor_lock
);
2195 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, 0, 1 << MINORBITS
, GFP_NOWAIT
);
2197 spin_unlock(&_minor_lock
);
2205 static const struct block_device_operations dm_blk_dops
;
2207 static void dm_wq_work(struct work_struct
*work
);
2209 static void dm_init_md_queue(struct mapped_device
*md
)
2212 * Request-based dm devices cannot be stacked on top of bio-based dm
2213 * devices. The type of this dm device may not have been decided yet.
2214 * The type is decided at the first table loading time.
2215 * To prevent problematic device stacking, clear the queue flag
2216 * for request stacking support until then.
2218 * This queue is new, so no concurrency on the queue_flags.
2220 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE
, md
->queue
);
2223 static void dm_init_old_md_queue(struct mapped_device
*md
)
2225 dm_init_md_queue(md
);
2228 * Initialize aspects of queue that aren't relevant for blk-mq
2230 md
->queue
->queuedata
= md
;
2231 md
->queue
->backing_dev_info
.congested_fn
= dm_any_congested
;
2232 md
->queue
->backing_dev_info
.congested_data
= md
;
2234 blk_queue_bounce_limit(md
->queue
, BLK_BOUNCE_ANY
);
2238 * Allocate and initialise a blank device with a given minor.
2240 static struct mapped_device
*alloc_dev(int minor
)
2243 struct mapped_device
*md
= kzalloc(sizeof(*md
), GFP_KERNEL
);
2247 DMWARN("unable to allocate device, out of memory.");
2251 if (!try_module_get(THIS_MODULE
))
2252 goto bad_module_get
;
2254 /* get a minor number for the dev */
2255 if (minor
== DM_ANY_MINOR
)
2256 r
= next_free_minor(&minor
);
2258 r
= specific_minor(minor
);
2262 r
= init_srcu_struct(&md
->io_barrier
);
2264 goto bad_io_barrier
;
2266 md
->type
= DM_TYPE_NONE
;
2267 mutex_init(&md
->suspend_lock
);
2268 mutex_init(&md
->type_lock
);
2269 mutex_init(&md
->table_devices_lock
);
2270 spin_lock_init(&md
->deferred_lock
);
2271 atomic_set(&md
->holders
, 1);
2272 atomic_set(&md
->open_count
, 0);
2273 atomic_set(&md
->event_nr
, 0);
2274 atomic_set(&md
->uevent_seq
, 0);
2275 INIT_LIST_HEAD(&md
->uevent_list
);
2276 INIT_LIST_HEAD(&md
->table_devices
);
2277 spin_lock_init(&md
->uevent_lock
);
2279 md
->queue
= blk_alloc_queue(GFP_KERNEL
);
2283 dm_init_md_queue(md
);
2285 md
->disk
= alloc_disk(1);
2289 atomic_set(&md
->pending
[0], 0);
2290 atomic_set(&md
->pending
[1], 0);
2291 init_waitqueue_head(&md
->wait
);
2292 INIT_WORK(&md
->work
, dm_wq_work
);
2293 init_waitqueue_head(&md
->eventq
);
2294 init_completion(&md
->kobj_holder
.completion
);
2295 md
->kworker_task
= NULL
;
2297 md
->disk
->major
= _major
;
2298 md
->disk
->first_minor
= minor
;
2299 md
->disk
->fops
= &dm_blk_dops
;
2300 md
->disk
->queue
= md
->queue
;
2301 md
->disk
->private_data
= md
;
2302 sprintf(md
->disk
->disk_name
, "dm-%d", minor
);
2304 format_dev_t(md
->name
, MKDEV(_major
, minor
));
2306 md
->wq
= alloc_workqueue("kdmflush", WQ_MEM_RECLAIM
, 0);
2310 md
->bdev
= bdget_disk(md
->disk
, 0);
2314 bio_init(&md
->flush_bio
);
2315 md
->flush_bio
.bi_bdev
= md
->bdev
;
2316 md
->flush_bio
.bi_rw
= WRITE_FLUSH
;
2318 dm_stats_init(&md
->stats
);
2320 /* Populate the mapping, nobody knows we exist yet */
2321 spin_lock(&_minor_lock
);
2322 old_md
= idr_replace(&_minor_idr
, md
, minor
);
2323 spin_unlock(&_minor_lock
);
2325 BUG_ON(old_md
!= MINOR_ALLOCED
);
2330 destroy_workqueue(md
->wq
);
2332 del_gendisk(md
->disk
);
2335 blk_cleanup_queue(md
->queue
);
2337 cleanup_srcu_struct(&md
->io_barrier
);
2341 module_put(THIS_MODULE
);
2347 static void unlock_fs(struct mapped_device
*md
);
2349 static void free_dev(struct mapped_device
*md
)
2351 int minor
= MINOR(disk_devt(md
->disk
));
2352 bool using_blk_mq
= !!md
->queue
->mq_ops
;
2355 destroy_workqueue(md
->wq
);
2357 if (md
->kworker_task
)
2358 kthread_stop(md
->kworker_task
);
2360 mempool_destroy(md
->io_pool
);
2362 mempool_destroy(md
->rq_pool
);
2364 bioset_free(md
->bs
);
2366 cleanup_srcu_struct(&md
->io_barrier
);
2367 free_table_devices(&md
->table_devices
);
2368 dm_stats_cleanup(&md
->stats
);
2370 spin_lock(&_minor_lock
);
2371 md
->disk
->private_data
= NULL
;
2372 spin_unlock(&_minor_lock
);
2373 if (blk_get_integrity(md
->disk
))
2374 blk_integrity_unregister(md
->disk
);
2375 del_gendisk(md
->disk
);
2377 blk_cleanup_queue(md
->queue
);
2379 blk_mq_free_tag_set(&md
->tag_set
);
2383 module_put(THIS_MODULE
);
2387 static void __bind_mempools(struct mapped_device
*md
, struct dm_table
*t
)
2389 struct dm_md_mempools
*p
= dm_table_get_md_mempools(t
);
2391 if (md
->io_pool
&& md
->bs
) {
2392 /* The md already has necessary mempools. */
2393 if (dm_table_get_type(t
) == DM_TYPE_BIO_BASED
) {
2395 * Reload bioset because front_pad may have changed
2396 * because a different table was loaded.
2398 bioset_free(md
->bs
);
2403 * There's no need to reload with request-based dm
2404 * because the size of front_pad doesn't change.
2405 * Note for future: If you are to reload bioset,
2406 * prep-ed requests in the queue may refer
2407 * to bio from the old bioset, so you must walk
2408 * through the queue to unprep.
2413 BUG_ON(!p
|| md
->io_pool
|| md
->rq_pool
|| md
->bs
);
2415 md
->io_pool
= p
->io_pool
;
2417 md
->rq_pool
= p
->rq_pool
;
2423 /* mempool bind completed, no longer need any mempools in the table */
2424 dm_table_free_md_mempools(t
);
2428 * Bind a table to the device.
2430 static void event_callback(void *context
)
2432 unsigned long flags
;
2434 struct mapped_device
*md
= (struct mapped_device
*) context
;
2436 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2437 list_splice_init(&md
->uevent_list
, &uevents
);
2438 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2440 dm_send_uevents(&uevents
, &disk_to_dev(md
->disk
)->kobj
);
2442 atomic_inc(&md
->event_nr
);
2443 wake_up(&md
->eventq
);
2447 * Protected by md->suspend_lock obtained by dm_swap_table().
2449 static void __set_size(struct mapped_device
*md
, sector_t size
)
2451 set_capacity(md
->disk
, size
);
2453 i_size_write(md
->bdev
->bd_inode
, (loff_t
)size
<< SECTOR_SHIFT
);
2457 * Return 1 if the queue has a compulsory merge_bvec_fn function.
2459 * If this function returns 0, then the device is either a non-dm
2460 * device without a merge_bvec_fn, or it is a dm device that is
2461 * able to split any bios it receives that are too big.
2463 int dm_queue_merge_is_compulsory(struct request_queue
*q
)
2465 struct mapped_device
*dev_md
;
2467 if (!q
->merge_bvec_fn
)
2470 if (q
->make_request_fn
== dm_make_request
) {
2471 dev_md
= q
->queuedata
;
2472 if (test_bit(DMF_MERGE_IS_OPTIONAL
, &dev_md
->flags
))
2479 static int dm_device_merge_is_compulsory(struct dm_target
*ti
,
2480 struct dm_dev
*dev
, sector_t start
,
2481 sector_t len
, void *data
)
2483 struct block_device
*bdev
= dev
->bdev
;
2484 struct request_queue
*q
= bdev_get_queue(bdev
);
2486 return dm_queue_merge_is_compulsory(q
);
2490 * Return 1 if it is acceptable to ignore merge_bvec_fn based
2491 * on the properties of the underlying devices.
2493 static int dm_table_merge_is_optional(struct dm_table
*table
)
2496 struct dm_target
*ti
;
2498 while (i
< dm_table_get_num_targets(table
)) {
2499 ti
= dm_table_get_target(table
, i
++);
2501 if (ti
->type
->iterate_devices
&&
2502 ti
->type
->iterate_devices(ti
, dm_device_merge_is_compulsory
, NULL
))
2510 * Returns old map, which caller must destroy.
2512 static struct dm_table
*__bind(struct mapped_device
*md
, struct dm_table
*t
,
2513 struct queue_limits
*limits
)
2515 struct dm_table
*old_map
;
2516 struct request_queue
*q
= md
->queue
;
2518 int merge_is_optional
;
2520 size
= dm_table_get_size(t
);
2523 * Wipe any geometry if the size of the table changed.
2525 if (size
!= dm_get_size(md
))
2526 memset(&md
->geometry
, 0, sizeof(md
->geometry
));
2528 __set_size(md
, size
);
2530 dm_table_event_callback(t
, event_callback
, md
);
2533 * The queue hasn't been stopped yet, if the old table type wasn't
2534 * for request-based during suspension. So stop it to prevent
2535 * I/O mapping before resume.
2536 * This must be done before setting the queue restrictions,
2537 * because request-based dm may be run just after the setting.
2539 if (dm_table_request_based(t
))
2542 __bind_mempools(md
, t
);
2544 merge_is_optional
= dm_table_merge_is_optional(t
);
2546 old_map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
2547 rcu_assign_pointer(md
->map
, t
);
2548 md
->immutable_target_type
= dm_table_get_immutable_target_type(t
);
2550 dm_table_set_restrictions(t
, q
, limits
);
2551 if (merge_is_optional
)
2552 set_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2554 clear_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2562 * Returns unbound table for the caller to free.
2564 static struct dm_table
*__unbind(struct mapped_device
*md
)
2566 struct dm_table
*map
= rcu_dereference_protected(md
->map
, 1);
2571 dm_table_event_callback(map
, NULL
, NULL
);
2572 RCU_INIT_POINTER(md
->map
, NULL
);
2579 * Constructor for a new device.
2581 int dm_create(int minor
, struct mapped_device
**result
)
2583 struct mapped_device
*md
;
2585 md
= alloc_dev(minor
);
2596 * Functions to manage md->type.
2597 * All are required to hold md->type_lock.
2599 void dm_lock_md_type(struct mapped_device
*md
)
2601 mutex_lock(&md
->type_lock
);
2604 void dm_unlock_md_type(struct mapped_device
*md
)
2606 mutex_unlock(&md
->type_lock
);
2609 void dm_set_md_type(struct mapped_device
*md
, unsigned type
)
2611 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2615 unsigned dm_get_md_type(struct mapped_device
*md
)
2617 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2621 struct target_type
*dm_get_immutable_target_type(struct mapped_device
*md
)
2623 return md
->immutable_target_type
;
2627 * The queue_limits are only valid as long as you have a reference
2630 struct queue_limits
*dm_get_queue_limits(struct mapped_device
*md
)
2632 BUG_ON(!atomic_read(&md
->holders
));
2633 return &md
->queue
->limits
;
2635 EXPORT_SYMBOL_GPL(dm_get_queue_limits
);
2637 static void init_rq_based_worker_thread(struct mapped_device
*md
)
2639 /* Initialize the request-based DM worker thread */
2640 init_kthread_worker(&md
->kworker
);
2641 md
->kworker_task
= kthread_run(kthread_worker_fn
, &md
->kworker
,
2642 "kdmwork-%s", dm_device_name(md
));
2646 * Fully initialize a request-based queue (->elevator, ->request_fn, etc).
2648 static int dm_init_request_based_queue(struct mapped_device
*md
)
2650 struct request_queue
*q
= NULL
;
2652 if (md
->queue
->elevator
)
2655 /* Fully initialize the queue */
2656 q
= blk_init_allocated_queue(md
->queue
, dm_request_fn
, NULL
);
2660 /* disable dm_request_fn's merge heuristic by default */
2661 md
->seq_rq_merge_deadline_usecs
= 0;
2664 dm_init_old_md_queue(md
);
2665 blk_queue_softirq_done(md
->queue
, dm_softirq_done
);
2666 blk_queue_prep_rq(md
->queue
, dm_prep_fn
);
2668 init_rq_based_worker_thread(md
);
2670 elv_register_queue(md
->queue
);
2675 static int dm_mq_init_request(void *data
, struct request
*rq
,
2676 unsigned int hctx_idx
, unsigned int request_idx
,
2677 unsigned int numa_node
)
2679 struct mapped_device
*md
= data
;
2680 struct dm_rq_target_io
*tio
= blk_mq_rq_to_pdu(rq
);
2683 * Must initialize md member of tio, otherwise it won't
2684 * be available in dm_mq_queue_rq.
2691 static int dm_mq_queue_rq(struct blk_mq_hw_ctx
*hctx
,
2692 const struct blk_mq_queue_data
*bd
)
2694 struct request
*rq
= bd
->rq
;
2695 struct dm_rq_target_io
*tio
= blk_mq_rq_to_pdu(rq
);
2696 struct mapped_device
*md
= tio
->md
;
2698 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
2699 struct dm_target
*ti
;
2702 /* always use block 0 to find the target for flushes for now */
2704 if (!(rq
->cmd_flags
& REQ_FLUSH
))
2705 pos
= blk_rq_pos(rq
);
2707 ti
= dm_table_find_target(map
, pos
);
2708 if (!dm_target_is_valid(ti
)) {
2709 dm_put_live_table(md
, srcu_idx
);
2710 DMERR_LIMIT("request attempted access beyond the end of device");
2712 * Must perform setup, that rq_completed() requires,
2713 * before returning BLK_MQ_RQ_QUEUE_ERROR
2715 dm_start_request(md
, rq
);
2716 return BLK_MQ_RQ_QUEUE_ERROR
;
2718 dm_put_live_table(md
, srcu_idx
);
2720 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
2721 return BLK_MQ_RQ_QUEUE_BUSY
;
2723 dm_start_request(md
, rq
);
2725 /* Init tio using md established in .init_request */
2726 init_tio(tio
, rq
, md
);
2729 * Establish tio->ti before queuing work (map_tio_request)
2730 * or making direct call to map_request().
2734 /* Clone the request if underlying devices aren't blk-mq */
2735 if (dm_table_get_type(map
) == DM_TYPE_REQUEST_BASED
) {
2736 /* clone request is allocated at the end of the pdu */
2737 tio
->clone
= (void *)blk_mq_rq_to_pdu(rq
) + sizeof(struct dm_rq_target_io
);
2738 if (!clone_rq(rq
, md
, tio
, GFP_ATOMIC
))
2739 return BLK_MQ_RQ_QUEUE_BUSY
;
2740 queue_kthread_work(&md
->kworker
, &tio
->work
);
2742 /* Direct call is fine since .queue_rq allows allocations */
2743 if (map_request(tio
, rq
, md
) == DM_MAPIO_REQUEUE
)
2744 dm_requeue_unmapped_original_request(md
, rq
);
2747 return BLK_MQ_RQ_QUEUE_OK
;
2750 static struct blk_mq_ops dm_mq_ops
= {
2751 .queue_rq
= dm_mq_queue_rq
,
2752 .map_queue
= blk_mq_map_queue
,
2753 .complete
= dm_softirq_done
,
2754 .init_request
= dm_mq_init_request
,
2757 static int dm_init_request_based_blk_mq_queue(struct mapped_device
*md
)
2759 unsigned md_type
= dm_get_md_type(md
);
2760 struct request_queue
*q
;
2763 memset(&md
->tag_set
, 0, sizeof(md
->tag_set
));
2764 md
->tag_set
.ops
= &dm_mq_ops
;
2765 md
->tag_set
.queue_depth
= BLKDEV_MAX_RQ
;
2766 md
->tag_set
.numa_node
= NUMA_NO_NODE
;
2767 md
->tag_set
.flags
= BLK_MQ_F_SHOULD_MERGE
| BLK_MQ_F_SG_MERGE
;
2768 md
->tag_set
.nr_hw_queues
= 1;
2769 if (md_type
== DM_TYPE_REQUEST_BASED
) {
2770 /* make the memory for non-blk-mq clone part of the pdu */
2771 md
->tag_set
.cmd_size
= sizeof(struct dm_rq_target_io
) + sizeof(struct request
);
2773 md
->tag_set
.cmd_size
= sizeof(struct dm_rq_target_io
);
2774 md
->tag_set
.driver_data
= md
;
2776 err
= blk_mq_alloc_tag_set(&md
->tag_set
);
2780 q
= blk_mq_init_allocated_queue(&md
->tag_set
, md
->queue
);
2786 dm_init_md_queue(md
);
2788 /* backfill 'mq' sysfs registration normally done in blk_register_queue */
2789 blk_mq_register_disk(md
->disk
);
2791 if (md_type
== DM_TYPE_REQUEST_BASED
)
2792 init_rq_based_worker_thread(md
);
2797 blk_mq_free_tag_set(&md
->tag_set
);
2802 * Setup the DM device's queue based on md's type
2804 int dm_setup_md_queue(struct mapped_device
*md
)
2807 unsigned md_type
= dm_get_md_type(md
);
2810 case DM_TYPE_REQUEST_BASED
:
2811 r
= dm_init_request_based_queue(md
);
2813 DMWARN("Cannot initialize queue for request-based mapped device");
2817 case DM_TYPE_MQ_REQUEST_BASED
:
2818 r
= dm_init_request_based_blk_mq_queue(md
);
2820 DMWARN("Cannot initialize queue for request-based blk-mq mapped device");
2824 case DM_TYPE_BIO_BASED
:
2825 dm_init_old_md_queue(md
);
2826 blk_queue_make_request(md
->queue
, dm_make_request
);
2827 blk_queue_merge_bvec(md
->queue
, dm_merge_bvec
);
2834 struct mapped_device
*dm_get_md(dev_t dev
)
2836 struct mapped_device
*md
;
2837 unsigned minor
= MINOR(dev
);
2839 if (MAJOR(dev
) != _major
|| minor
>= (1 << MINORBITS
))
2842 spin_lock(&_minor_lock
);
2844 md
= idr_find(&_minor_idr
, minor
);
2846 if ((md
== MINOR_ALLOCED
||
2847 (MINOR(disk_devt(dm_disk(md
))) != minor
) ||
2848 dm_deleting_md(md
) ||
2849 test_bit(DMF_FREEING
, &md
->flags
))) {
2857 spin_unlock(&_minor_lock
);
2861 EXPORT_SYMBOL_GPL(dm_get_md
);
2863 void *dm_get_mdptr(struct mapped_device
*md
)
2865 return md
->interface_ptr
;
2868 void dm_set_mdptr(struct mapped_device
*md
, void *ptr
)
2870 md
->interface_ptr
= ptr
;
2873 void dm_get(struct mapped_device
*md
)
2875 atomic_inc(&md
->holders
);
2876 BUG_ON(test_bit(DMF_FREEING
, &md
->flags
));
2879 int dm_hold(struct mapped_device
*md
)
2881 spin_lock(&_minor_lock
);
2882 if (test_bit(DMF_FREEING
, &md
->flags
)) {
2883 spin_unlock(&_minor_lock
);
2887 spin_unlock(&_minor_lock
);
2890 EXPORT_SYMBOL_GPL(dm_hold
);
2892 const char *dm_device_name(struct mapped_device
*md
)
2896 EXPORT_SYMBOL_GPL(dm_device_name
);
2898 static void __dm_destroy(struct mapped_device
*md
, bool wait
)
2900 struct dm_table
*map
;
2905 map
= dm_get_live_table(md
, &srcu_idx
);
2907 spin_lock(&_minor_lock
);
2908 idr_replace(&_minor_idr
, MINOR_ALLOCED
, MINOR(disk_devt(dm_disk(md
))));
2909 set_bit(DMF_FREEING
, &md
->flags
);
2910 spin_unlock(&_minor_lock
);
2912 if (dm_request_based(md
) && md
->kworker_task
)
2913 flush_kthread_worker(&md
->kworker
);
2916 * Take suspend_lock so that presuspend and postsuspend methods
2917 * do not race with internal suspend.
2919 mutex_lock(&md
->suspend_lock
);
2920 if (!dm_suspended_md(md
)) {
2921 dm_table_presuspend_targets(map
);
2922 dm_table_postsuspend_targets(map
);
2924 mutex_unlock(&md
->suspend_lock
);
2926 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2927 dm_put_live_table(md
, srcu_idx
);
2930 * Rare, but there may be I/O requests still going to complete,
2931 * for example. Wait for all references to disappear.
2932 * No one should increment the reference count of the mapped_device,
2933 * after the mapped_device state becomes DMF_FREEING.
2936 while (atomic_read(&md
->holders
))
2938 else if (atomic_read(&md
->holders
))
2939 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2940 dm_device_name(md
), atomic_read(&md
->holders
));
2943 dm_table_destroy(__unbind(md
));
2947 void dm_destroy(struct mapped_device
*md
)
2949 __dm_destroy(md
, true);
2952 void dm_destroy_immediate(struct mapped_device
*md
)
2954 __dm_destroy(md
, false);
2957 void dm_put(struct mapped_device
*md
)
2959 atomic_dec(&md
->holders
);
2961 EXPORT_SYMBOL_GPL(dm_put
);
2963 static int dm_wait_for_completion(struct mapped_device
*md
, int interruptible
)
2966 DECLARE_WAITQUEUE(wait
, current
);
2968 add_wait_queue(&md
->wait
, &wait
);
2971 set_current_state(interruptible
);
2973 if (!md_in_flight(md
))
2976 if (interruptible
== TASK_INTERRUPTIBLE
&&
2977 signal_pending(current
)) {
2984 set_current_state(TASK_RUNNING
);
2986 remove_wait_queue(&md
->wait
, &wait
);
2992 * Process the deferred bios
2994 static void dm_wq_work(struct work_struct
*work
)
2996 struct mapped_device
*md
= container_of(work
, struct mapped_device
,
3000 struct dm_table
*map
;
3002 map
= dm_get_live_table(md
, &srcu_idx
);
3004 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
3005 spin_lock_irq(&md
->deferred_lock
);
3006 c
= bio_list_pop(&md
->deferred
);
3007 spin_unlock_irq(&md
->deferred_lock
);
3012 if (dm_request_based(md
))
3013 generic_make_request(c
);
3015 __split_and_process_bio(md
, map
, c
);
3018 dm_put_live_table(md
, srcu_idx
);
3021 static void dm_queue_flush(struct mapped_device
*md
)
3023 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
3024 smp_mb__after_atomic();
3025 queue_work(md
->wq
, &md
->work
);
3029 * Swap in a new table, returning the old one for the caller to destroy.
3031 struct dm_table
*dm_swap_table(struct mapped_device
*md
, struct dm_table
*table
)
3033 struct dm_table
*live_map
= NULL
, *map
= ERR_PTR(-EINVAL
);
3034 struct queue_limits limits
;
3037 mutex_lock(&md
->suspend_lock
);
3039 /* device must be suspended */
3040 if (!dm_suspended_md(md
))
3044 * If the new table has no data devices, retain the existing limits.
3045 * This helps multipath with queue_if_no_path if all paths disappear,
3046 * then new I/O is queued based on these limits, and then some paths
3049 if (dm_table_has_no_data_devices(table
)) {
3050 live_map
= dm_get_live_table_fast(md
);
3052 limits
= md
->queue
->limits
;
3053 dm_put_live_table_fast(md
);
3057 r
= dm_calculate_queue_limits(table
, &limits
);
3064 map
= __bind(md
, table
, &limits
);
3067 mutex_unlock(&md
->suspend_lock
);
3072 * Functions to lock and unlock any filesystem running on the
3075 static int lock_fs(struct mapped_device
*md
)
3079 WARN_ON(md
->frozen_sb
);
3081 md
->frozen_sb
= freeze_bdev(md
->bdev
);
3082 if (IS_ERR(md
->frozen_sb
)) {
3083 r
= PTR_ERR(md
->frozen_sb
);
3084 md
->frozen_sb
= NULL
;
3088 set_bit(DMF_FROZEN
, &md
->flags
);
3093 static void unlock_fs(struct mapped_device
*md
)
3095 if (!test_bit(DMF_FROZEN
, &md
->flags
))
3098 thaw_bdev(md
->bdev
, md
->frozen_sb
);
3099 md
->frozen_sb
= NULL
;
3100 clear_bit(DMF_FROZEN
, &md
->flags
);
3104 * If __dm_suspend returns 0, the device is completely quiescent
3105 * now. There is no request-processing activity. All new requests
3106 * are being added to md->deferred list.
3108 * Caller must hold md->suspend_lock
3110 static int __dm_suspend(struct mapped_device
*md
, struct dm_table
*map
,
3111 unsigned suspend_flags
, int interruptible
)
3113 bool do_lockfs
= suspend_flags
& DM_SUSPEND_LOCKFS_FLAG
;
3114 bool noflush
= suspend_flags
& DM_SUSPEND_NOFLUSH_FLAG
;
3118 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
3119 * This flag is cleared before dm_suspend returns.
3122 set_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
3125 * This gets reverted if there's an error later and the targets
3126 * provide the .presuspend_undo hook.
3128 dm_table_presuspend_targets(map
);
3131 * Flush I/O to the device.
3132 * Any I/O submitted after lock_fs() may not be flushed.
3133 * noflush takes precedence over do_lockfs.
3134 * (lock_fs() flushes I/Os and waits for them to complete.)
3136 if (!noflush
&& do_lockfs
) {
3139 dm_table_presuspend_undo_targets(map
);
3145 * Here we must make sure that no processes are submitting requests
3146 * to target drivers i.e. no one may be executing
3147 * __split_and_process_bio. This is called from dm_request and
3150 * To get all processes out of __split_and_process_bio in dm_request,
3151 * we take the write lock. To prevent any process from reentering
3152 * __split_and_process_bio from dm_request and quiesce the thread
3153 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
3154 * flush_workqueue(md->wq).
3156 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
3158 synchronize_srcu(&md
->io_barrier
);
3161 * Stop md->queue before flushing md->wq in case request-based
3162 * dm defers requests to md->wq from md->queue.
3164 if (dm_request_based(md
)) {
3165 stop_queue(md
->queue
);
3166 if (md
->kworker_task
)
3167 flush_kthread_worker(&md
->kworker
);
3170 flush_workqueue(md
->wq
);
3173 * At this point no more requests are entering target request routines.
3174 * We call dm_wait_for_completion to wait for all existing requests
3177 r
= dm_wait_for_completion(md
, interruptible
);
3180 clear_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
3182 synchronize_srcu(&md
->io_barrier
);
3184 /* were we interrupted ? */
3188 if (dm_request_based(md
))
3189 start_queue(md
->queue
);
3192 dm_table_presuspend_undo_targets(map
);
3193 /* pushback list is already flushed, so skip flush */
3200 * We need to be able to change a mapping table under a mounted
3201 * filesystem. For example we might want to move some data in
3202 * the background. Before the table can be swapped with
3203 * dm_bind_table, dm_suspend must be called to flush any in
3204 * flight bios and ensure that any further io gets deferred.
3207 * Suspend mechanism in request-based dm.
3209 * 1. Flush all I/Os by lock_fs() if needed.
3210 * 2. Stop dispatching any I/O by stopping the request_queue.
3211 * 3. Wait for all in-flight I/Os to be completed or requeued.
3213 * To abort suspend, start the request_queue.
3215 int dm_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
3217 struct dm_table
*map
= NULL
;
3221 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
3223 if (dm_suspended_md(md
)) {
3228 if (dm_suspended_internally_md(md
)) {
3229 /* already internally suspended, wait for internal resume */
3230 mutex_unlock(&md
->suspend_lock
);
3231 r
= wait_on_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
, TASK_INTERRUPTIBLE
);
3237 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
3239 r
= __dm_suspend(md
, map
, suspend_flags
, TASK_INTERRUPTIBLE
);
3243 set_bit(DMF_SUSPENDED
, &md
->flags
);
3245 dm_table_postsuspend_targets(map
);
3248 mutex_unlock(&md
->suspend_lock
);
3252 static int __dm_resume(struct mapped_device
*md
, struct dm_table
*map
)
3255 int r
= dm_table_resume_targets(map
);
3263 * Flushing deferred I/Os must be done after targets are resumed
3264 * so that mapping of targets can work correctly.
3265 * Request-based dm is queueing the deferred I/Os in its request_queue.
3267 if (dm_request_based(md
))
3268 start_queue(md
->queue
);
3275 int dm_resume(struct mapped_device
*md
)
3278 struct dm_table
*map
= NULL
;
3281 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
3283 if (!dm_suspended_md(md
))
3286 if (dm_suspended_internally_md(md
)) {
3287 /* already internally suspended, wait for internal resume */
3288 mutex_unlock(&md
->suspend_lock
);
3289 r
= wait_on_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
, TASK_INTERRUPTIBLE
);
3295 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
3296 if (!map
|| !dm_table_get_size(map
))
3299 r
= __dm_resume(md
, map
);
3303 clear_bit(DMF_SUSPENDED
, &md
->flags
);
3307 mutex_unlock(&md
->suspend_lock
);
3313 * Internal suspend/resume works like userspace-driven suspend. It waits
3314 * until all bios finish and prevents issuing new bios to the target drivers.
3315 * It may be used only from the kernel.
3318 static void __dm_internal_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
3320 struct dm_table
*map
= NULL
;
3322 if (md
->internal_suspend_count
++)
3323 return; /* nested internal suspend */
3325 if (dm_suspended_md(md
)) {
3326 set_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3327 return; /* nest suspend */
3330 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
3333 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
3334 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
3335 * would require changing .presuspend to return an error -- avoid this
3336 * until there is a need for more elaborate variants of internal suspend.
3338 (void) __dm_suspend(md
, map
, suspend_flags
, TASK_UNINTERRUPTIBLE
);
3340 set_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3342 dm_table_postsuspend_targets(map
);
3345 static void __dm_internal_resume(struct mapped_device
*md
)
3347 BUG_ON(!md
->internal_suspend_count
);
3349 if (--md
->internal_suspend_count
)
3350 return; /* resume from nested internal suspend */
3352 if (dm_suspended_md(md
))
3353 goto done
; /* resume from nested suspend */
3356 * NOTE: existing callers don't need to call dm_table_resume_targets
3357 * (which may fail -- so best to avoid it for now by passing NULL map)
3359 (void) __dm_resume(md
, NULL
);
3362 clear_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3363 smp_mb__after_atomic();
3364 wake_up_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
);
3367 void dm_internal_suspend_noflush(struct mapped_device
*md
)
3369 mutex_lock(&md
->suspend_lock
);
3370 __dm_internal_suspend(md
, DM_SUSPEND_NOFLUSH_FLAG
);
3371 mutex_unlock(&md
->suspend_lock
);
3373 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush
);
3375 void dm_internal_resume(struct mapped_device
*md
)
3377 mutex_lock(&md
->suspend_lock
);
3378 __dm_internal_resume(md
);
3379 mutex_unlock(&md
->suspend_lock
);
3381 EXPORT_SYMBOL_GPL(dm_internal_resume
);
3384 * Fast variants of internal suspend/resume hold md->suspend_lock,
3385 * which prevents interaction with userspace-driven suspend.
3388 void dm_internal_suspend_fast(struct mapped_device
*md
)
3390 mutex_lock(&md
->suspend_lock
);
3391 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
3394 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
3395 synchronize_srcu(&md
->io_barrier
);
3396 flush_workqueue(md
->wq
);
3397 dm_wait_for_completion(md
, TASK_UNINTERRUPTIBLE
);
3399 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast
);
3401 void dm_internal_resume_fast(struct mapped_device
*md
)
3403 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
3409 mutex_unlock(&md
->suspend_lock
);
3411 EXPORT_SYMBOL_GPL(dm_internal_resume_fast
);
3413 /*-----------------------------------------------------------------
3414 * Event notification.
3415 *---------------------------------------------------------------*/
3416 int dm_kobject_uevent(struct mapped_device
*md
, enum kobject_action action
,
3419 char udev_cookie
[DM_COOKIE_LENGTH
];
3420 char *envp
[] = { udev_cookie
, NULL
};
3423 return kobject_uevent(&disk_to_dev(md
->disk
)->kobj
, action
);
3425 snprintf(udev_cookie
, DM_COOKIE_LENGTH
, "%s=%u",
3426 DM_COOKIE_ENV_VAR_NAME
, cookie
);
3427 return kobject_uevent_env(&disk_to_dev(md
->disk
)->kobj
,
3432 uint32_t dm_next_uevent_seq(struct mapped_device
*md
)
3434 return atomic_add_return(1, &md
->uevent_seq
);
3437 uint32_t dm_get_event_nr(struct mapped_device
*md
)
3439 return atomic_read(&md
->event_nr
);
3442 int dm_wait_event(struct mapped_device
*md
, int event_nr
)
3444 return wait_event_interruptible(md
->eventq
,
3445 (event_nr
!= atomic_read(&md
->event_nr
)));
3448 void dm_uevent_add(struct mapped_device
*md
, struct list_head
*elist
)
3450 unsigned long flags
;
3452 spin_lock_irqsave(&md
->uevent_lock
, flags
);
3453 list_add(elist
, &md
->uevent_list
);
3454 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
3458 * The gendisk is only valid as long as you have a reference
3461 struct gendisk
*dm_disk(struct mapped_device
*md
)
3466 struct kobject
*dm_kobject(struct mapped_device
*md
)
3468 return &md
->kobj_holder
.kobj
;
3471 struct mapped_device
*dm_get_from_kobject(struct kobject
*kobj
)
3473 struct mapped_device
*md
;
3475 md
= container_of(kobj
, struct mapped_device
, kobj_holder
.kobj
);
3477 if (test_bit(DMF_FREEING
, &md
->flags
) ||
3485 int dm_suspended_md(struct mapped_device
*md
)
3487 return test_bit(DMF_SUSPENDED
, &md
->flags
);
3490 int dm_suspended_internally_md(struct mapped_device
*md
)
3492 return test_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3495 int dm_test_deferred_remove_flag(struct mapped_device
*md
)
3497 return test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
3500 int dm_suspended(struct dm_target
*ti
)
3502 return dm_suspended_md(dm_table_get_md(ti
->table
));
3504 EXPORT_SYMBOL_GPL(dm_suspended
);
3506 int dm_noflush_suspending(struct dm_target
*ti
)
3508 return __noflush_suspending(dm_table_get_md(ti
->table
));
3510 EXPORT_SYMBOL_GPL(dm_noflush_suspending
);
3512 struct dm_md_mempools
*dm_alloc_md_mempools(unsigned type
, unsigned integrity
, unsigned per_bio_data_size
)
3514 struct dm_md_mempools
*pools
= kzalloc(sizeof(*pools
), GFP_KERNEL
);
3515 struct kmem_cache
*cachep
;
3516 unsigned int pool_size
= 0;
3517 unsigned int front_pad
;
3523 case DM_TYPE_BIO_BASED
:
3525 pool_size
= dm_get_reserved_bio_based_ios();
3526 front_pad
= roundup(per_bio_data_size
, __alignof__(struct dm_target_io
)) + offsetof(struct dm_target_io
, clone
);
3528 case DM_TYPE_REQUEST_BASED
:
3529 pool_size
= dm_get_reserved_rq_based_ios();
3530 pools
->rq_pool
= mempool_create_slab_pool(pool_size
, _rq_cache
);
3531 if (!pools
->rq_pool
)
3533 /* fall through to setup remaining rq-based pools */
3534 case DM_TYPE_MQ_REQUEST_BASED
:
3535 cachep
= _rq_tio_cache
;
3537 pool_size
= dm_get_reserved_rq_based_ios();
3538 front_pad
= offsetof(struct dm_rq_clone_bio_info
, clone
);
3539 /* per_bio_data_size is not used. See __bind_mempools(). */
3540 WARN_ON(per_bio_data_size
!= 0);
3546 pools
->io_pool
= mempool_create_slab_pool(pool_size
, cachep
);
3547 if (!pools
->io_pool
)
3550 pools
->bs
= bioset_create_nobvec(pool_size
, front_pad
);
3554 if (integrity
&& bioset_integrity_create(pools
->bs
, pool_size
))
3560 dm_free_md_mempools(pools
);
3565 void dm_free_md_mempools(struct dm_md_mempools
*pools
)
3571 mempool_destroy(pools
->io_pool
);
3574 mempool_destroy(pools
->rq_pool
);
3577 bioset_free(pools
->bs
);
3582 static const struct block_device_operations dm_blk_dops
= {
3583 .open
= dm_blk_open
,
3584 .release
= dm_blk_close
,
3585 .ioctl
= dm_blk_ioctl
,
3586 .getgeo
= dm_blk_getgeo
,
3587 .owner
= THIS_MODULE
3593 module_init(dm_init
);
3594 module_exit(dm_exit
);
3596 module_param(major
, uint
, 0);
3597 MODULE_PARM_DESC(major
, "The major number of the device mapper");
3599 module_param(reserved_bio_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
3600 MODULE_PARM_DESC(reserved_bio_based_ios
, "Reserved IOs in bio-based mempools");
3602 module_param(reserved_rq_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
3603 MODULE_PARM_DESC(reserved_rq_based_ios
, "Reserved IOs in request-based mempools");
3605 MODULE_DESCRIPTION(DM_NAME
" driver");
3606 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3607 MODULE_LICENSE("GPL");