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 #ifdef CONFIG_DM_MQ_DEFAULT
235 static bool use_blk_mq
= true;
237 static bool use_blk_mq
= false;
240 bool dm_use_blk_mq(struct mapped_device
*md
)
242 return md
->use_blk_mq
;
246 * For mempools pre-allocation at the table loading time.
248 struct dm_md_mempools
{
254 struct table_device
{
255 struct list_head list
;
257 struct dm_dev dm_dev
;
260 #define RESERVED_BIO_BASED_IOS 16
261 #define RESERVED_REQUEST_BASED_IOS 256
262 #define RESERVED_MAX_IOS 1024
263 static struct kmem_cache
*_io_cache
;
264 static struct kmem_cache
*_rq_tio_cache
;
265 static struct kmem_cache
*_rq_cache
;
268 * Bio-based DM's mempools' reserved IOs set by the user.
270 static unsigned reserved_bio_based_ios
= RESERVED_BIO_BASED_IOS
;
273 * Request-based DM's mempools' reserved IOs set by the user.
275 static unsigned reserved_rq_based_ios
= RESERVED_REQUEST_BASED_IOS
;
277 static unsigned __dm_get_module_param(unsigned *module_param
,
278 unsigned def
, unsigned max
)
280 unsigned param
= ACCESS_ONCE(*module_param
);
281 unsigned modified_param
= 0;
284 modified_param
= def
;
285 else if (param
> max
)
286 modified_param
= max
;
288 if (modified_param
) {
289 (void)cmpxchg(module_param
, param
, modified_param
);
290 param
= modified_param
;
296 unsigned dm_get_reserved_bio_based_ios(void)
298 return __dm_get_module_param(&reserved_bio_based_ios
,
299 RESERVED_BIO_BASED_IOS
, RESERVED_MAX_IOS
);
301 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios
);
303 unsigned dm_get_reserved_rq_based_ios(void)
305 return __dm_get_module_param(&reserved_rq_based_ios
,
306 RESERVED_REQUEST_BASED_IOS
, RESERVED_MAX_IOS
);
308 EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios
);
310 static int __init
local_init(void)
314 /* allocate a slab for the dm_ios */
315 _io_cache
= KMEM_CACHE(dm_io
, 0);
319 _rq_tio_cache
= KMEM_CACHE(dm_rq_target_io
, 0);
321 goto out_free_io_cache
;
323 _rq_cache
= kmem_cache_create("dm_clone_request", sizeof(struct request
),
324 __alignof__(struct request
), 0, NULL
);
326 goto out_free_rq_tio_cache
;
328 r
= dm_uevent_init();
330 goto out_free_rq_cache
;
332 deferred_remove_workqueue
= alloc_workqueue("kdmremove", WQ_UNBOUND
, 1);
333 if (!deferred_remove_workqueue
) {
335 goto out_uevent_exit
;
339 r
= register_blkdev(_major
, _name
);
341 goto out_free_workqueue
;
349 destroy_workqueue(deferred_remove_workqueue
);
353 kmem_cache_destroy(_rq_cache
);
354 out_free_rq_tio_cache
:
355 kmem_cache_destroy(_rq_tio_cache
);
357 kmem_cache_destroy(_io_cache
);
362 static void local_exit(void)
364 flush_scheduled_work();
365 destroy_workqueue(deferred_remove_workqueue
);
367 kmem_cache_destroy(_rq_cache
);
368 kmem_cache_destroy(_rq_tio_cache
);
369 kmem_cache_destroy(_io_cache
);
370 unregister_blkdev(_major
, _name
);
375 DMINFO("cleaned up");
378 static int (*_inits
[])(void) __initdata
= {
389 static void (*_exits
[])(void) = {
400 static int __init
dm_init(void)
402 const int count
= ARRAY_SIZE(_inits
);
406 for (i
= 0; i
< count
; i
++) {
421 static void __exit
dm_exit(void)
423 int i
= ARRAY_SIZE(_exits
);
429 * Should be empty by this point.
431 idr_destroy(&_minor_idr
);
435 * Block device functions
437 int dm_deleting_md(struct mapped_device
*md
)
439 return test_bit(DMF_DELETING
, &md
->flags
);
442 static int dm_blk_open(struct block_device
*bdev
, fmode_t mode
)
444 struct mapped_device
*md
;
446 spin_lock(&_minor_lock
);
448 md
= bdev
->bd_disk
->private_data
;
452 if (test_bit(DMF_FREEING
, &md
->flags
) ||
453 dm_deleting_md(md
)) {
459 atomic_inc(&md
->open_count
);
461 spin_unlock(&_minor_lock
);
463 return md
? 0 : -ENXIO
;
466 static void dm_blk_close(struct gendisk
*disk
, fmode_t mode
)
468 struct mapped_device
*md
;
470 spin_lock(&_minor_lock
);
472 md
= disk
->private_data
;
476 if (atomic_dec_and_test(&md
->open_count
) &&
477 (test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
)))
478 queue_work(deferred_remove_workqueue
, &deferred_remove_work
);
482 spin_unlock(&_minor_lock
);
485 int dm_open_count(struct mapped_device
*md
)
487 return atomic_read(&md
->open_count
);
491 * Guarantees nothing is using the device before it's deleted.
493 int dm_lock_for_deletion(struct mapped_device
*md
, bool mark_deferred
, bool only_deferred
)
497 spin_lock(&_minor_lock
);
499 if (dm_open_count(md
)) {
502 set_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
503 } else if (only_deferred
&& !test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
))
506 set_bit(DMF_DELETING
, &md
->flags
);
508 spin_unlock(&_minor_lock
);
513 int dm_cancel_deferred_remove(struct mapped_device
*md
)
517 spin_lock(&_minor_lock
);
519 if (test_bit(DMF_DELETING
, &md
->flags
))
522 clear_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
524 spin_unlock(&_minor_lock
);
529 static void do_deferred_remove(struct work_struct
*w
)
531 dm_deferred_remove();
534 sector_t
dm_get_size(struct mapped_device
*md
)
536 return get_capacity(md
->disk
);
539 struct request_queue
*dm_get_md_queue(struct mapped_device
*md
)
544 struct dm_stats
*dm_get_stats(struct mapped_device
*md
)
549 static int dm_blk_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
551 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
553 return dm_get_geometry(md
, geo
);
556 static int dm_blk_ioctl(struct block_device
*bdev
, fmode_t mode
,
557 unsigned int cmd
, unsigned long arg
)
559 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
561 struct dm_table
*map
;
562 struct dm_target
*tgt
;
566 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);
576 if (!tgt
->type
->ioctl
)
579 if (dm_suspended_md(md
)) {
584 r
= tgt
->type
->ioctl(tgt
, cmd
, arg
);
587 dm_put_live_table(md
, srcu_idx
);
589 if (r
== -ENOTCONN
) {
597 static struct dm_io
*alloc_io(struct mapped_device
*md
)
599 return mempool_alloc(md
->io_pool
, GFP_NOIO
);
602 static void free_io(struct mapped_device
*md
, struct dm_io
*io
)
604 mempool_free(io
, md
->io_pool
);
607 static void free_tio(struct mapped_device
*md
, struct dm_target_io
*tio
)
609 bio_put(&tio
->clone
);
612 static struct dm_rq_target_io
*alloc_rq_tio(struct mapped_device
*md
,
615 return mempool_alloc(md
->io_pool
, gfp_mask
);
618 static void free_rq_tio(struct dm_rq_target_io
*tio
)
620 mempool_free(tio
, tio
->md
->io_pool
);
623 static struct request
*alloc_clone_request(struct mapped_device
*md
,
626 return mempool_alloc(md
->rq_pool
, gfp_mask
);
629 static void free_clone_request(struct mapped_device
*md
, struct request
*rq
)
631 mempool_free(rq
, md
->rq_pool
);
634 static int md_in_flight(struct mapped_device
*md
)
636 return atomic_read(&md
->pending
[READ
]) +
637 atomic_read(&md
->pending
[WRITE
]);
640 static void start_io_acct(struct dm_io
*io
)
642 struct mapped_device
*md
= io
->md
;
643 struct bio
*bio
= io
->bio
;
645 int rw
= bio_data_dir(bio
);
647 io
->start_time
= jiffies
;
649 cpu
= part_stat_lock();
650 part_round_stats(cpu
, &dm_disk(md
)->part0
);
652 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
],
653 atomic_inc_return(&md
->pending
[rw
]));
655 if (unlikely(dm_stats_used(&md
->stats
)))
656 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
657 bio_sectors(bio
), false, 0, &io
->stats_aux
);
660 static void end_io_acct(struct dm_io
*io
)
662 struct mapped_device
*md
= io
->md
;
663 struct bio
*bio
= io
->bio
;
664 unsigned long duration
= jiffies
- io
->start_time
;
666 int rw
= bio_data_dir(bio
);
668 generic_end_io_acct(rw
, &dm_disk(md
)->part0
, io
->start_time
);
670 if (unlikely(dm_stats_used(&md
->stats
)))
671 dm_stats_account_io(&md
->stats
, bio
->bi_rw
, bio
->bi_iter
.bi_sector
,
672 bio_sectors(bio
), true, duration
, &io
->stats_aux
);
675 * After this is decremented the bio must not be touched if it is
678 pending
= atomic_dec_return(&md
->pending
[rw
]);
679 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
], pending
);
680 pending
+= atomic_read(&md
->pending
[rw
^0x1]);
682 /* nudge anyone waiting on suspend queue */
688 * Add the bio to the list of deferred io.
690 static void queue_io(struct mapped_device
*md
, struct bio
*bio
)
694 spin_lock_irqsave(&md
->deferred_lock
, flags
);
695 bio_list_add(&md
->deferred
, bio
);
696 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
697 queue_work(md
->wq
, &md
->work
);
701 * Everyone (including functions in this file), should use this
702 * function to access the md->map field, and make sure they call
703 * dm_put_live_table() when finished.
705 struct dm_table
*dm_get_live_table(struct mapped_device
*md
, int *srcu_idx
) __acquires(md
->io_barrier
)
707 *srcu_idx
= srcu_read_lock(&md
->io_barrier
);
709 return srcu_dereference(md
->map
, &md
->io_barrier
);
712 void dm_put_live_table(struct mapped_device
*md
, int srcu_idx
) __releases(md
->io_barrier
)
714 srcu_read_unlock(&md
->io_barrier
, srcu_idx
);
717 void dm_sync_table(struct mapped_device
*md
)
719 synchronize_srcu(&md
->io_barrier
);
720 synchronize_rcu_expedited();
724 * A fast alternative to dm_get_live_table/dm_put_live_table.
725 * The caller must not block between these two functions.
727 static struct dm_table
*dm_get_live_table_fast(struct mapped_device
*md
) __acquires(RCU
)
730 return rcu_dereference(md
->map
);
733 static void dm_put_live_table_fast(struct mapped_device
*md
) __releases(RCU
)
739 * Open a table device so we can use it as a map destination.
741 static int open_table_device(struct table_device
*td
, dev_t dev
,
742 struct mapped_device
*md
)
744 static char *_claim_ptr
= "I belong to device-mapper";
745 struct block_device
*bdev
;
749 BUG_ON(td
->dm_dev
.bdev
);
751 bdev
= blkdev_get_by_dev(dev
, td
->dm_dev
.mode
| FMODE_EXCL
, _claim_ptr
);
753 return PTR_ERR(bdev
);
755 r
= bd_link_disk_holder(bdev
, dm_disk(md
));
757 blkdev_put(bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
761 td
->dm_dev
.bdev
= bdev
;
766 * Close a table device that we've been using.
768 static void close_table_device(struct table_device
*td
, struct mapped_device
*md
)
770 if (!td
->dm_dev
.bdev
)
773 bd_unlink_disk_holder(td
->dm_dev
.bdev
, dm_disk(md
));
774 blkdev_put(td
->dm_dev
.bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
775 td
->dm_dev
.bdev
= NULL
;
778 static struct table_device
*find_table_device(struct list_head
*l
, dev_t dev
,
780 struct table_device
*td
;
782 list_for_each_entry(td
, l
, list
)
783 if (td
->dm_dev
.bdev
->bd_dev
== dev
&& td
->dm_dev
.mode
== mode
)
789 int dm_get_table_device(struct mapped_device
*md
, dev_t dev
, fmode_t mode
,
790 struct dm_dev
**result
) {
792 struct table_device
*td
;
794 mutex_lock(&md
->table_devices_lock
);
795 td
= find_table_device(&md
->table_devices
, dev
, mode
);
797 td
= kmalloc(sizeof(*td
), GFP_KERNEL
);
799 mutex_unlock(&md
->table_devices_lock
);
803 td
->dm_dev
.mode
= mode
;
804 td
->dm_dev
.bdev
= NULL
;
806 if ((r
= open_table_device(td
, dev
, md
))) {
807 mutex_unlock(&md
->table_devices_lock
);
812 format_dev_t(td
->dm_dev
.name
, dev
);
814 atomic_set(&td
->count
, 0);
815 list_add(&td
->list
, &md
->table_devices
);
817 atomic_inc(&td
->count
);
818 mutex_unlock(&md
->table_devices_lock
);
820 *result
= &td
->dm_dev
;
823 EXPORT_SYMBOL_GPL(dm_get_table_device
);
825 void dm_put_table_device(struct mapped_device
*md
, struct dm_dev
*d
)
827 struct table_device
*td
= container_of(d
, struct table_device
, dm_dev
);
829 mutex_lock(&md
->table_devices_lock
);
830 if (atomic_dec_and_test(&td
->count
)) {
831 close_table_device(td
, md
);
835 mutex_unlock(&md
->table_devices_lock
);
837 EXPORT_SYMBOL(dm_put_table_device
);
839 static void free_table_devices(struct list_head
*devices
)
841 struct list_head
*tmp
, *next
;
843 list_for_each_safe(tmp
, next
, devices
) {
844 struct table_device
*td
= list_entry(tmp
, struct table_device
, list
);
846 DMWARN("dm_destroy: %s still exists with %d references",
847 td
->dm_dev
.name
, atomic_read(&td
->count
));
853 * Get the geometry associated with a dm device
855 int dm_get_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
863 * Set the geometry of a device.
865 int dm_set_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
867 sector_t sz
= (sector_t
)geo
->cylinders
* geo
->heads
* geo
->sectors
;
869 if (geo
->start
> sz
) {
870 DMWARN("Start sector is beyond the geometry limits.");
879 /*-----------------------------------------------------------------
881 * A more elegant soln is in the works that uses the queue
882 * merge fn, unfortunately there are a couple of changes to
883 * the block layer that I want to make for this. So in the
884 * interests of getting something for people to use I give
885 * you this clearly demarcated crap.
886 *---------------------------------------------------------------*/
888 static int __noflush_suspending(struct mapped_device
*md
)
890 return test_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
894 * Decrements the number of outstanding ios that a bio has been
895 * cloned into, completing the original io if necc.
897 static void dec_pending(struct dm_io
*io
, int error
)
902 struct mapped_device
*md
= io
->md
;
904 /* Push-back supersedes any I/O errors */
905 if (unlikely(error
)) {
906 spin_lock_irqsave(&io
->endio_lock
, flags
);
907 if (!(io
->error
> 0 && __noflush_suspending(md
)))
909 spin_unlock_irqrestore(&io
->endio_lock
, flags
);
912 if (atomic_dec_and_test(&io
->io_count
)) {
913 if (io
->error
== DM_ENDIO_REQUEUE
) {
915 * Target requested pushing back the I/O.
917 spin_lock_irqsave(&md
->deferred_lock
, flags
);
918 if (__noflush_suspending(md
))
919 bio_list_add_head(&md
->deferred
, io
->bio
);
921 /* noflush suspend was interrupted. */
923 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
926 io_error
= io
->error
;
931 if (io_error
== DM_ENDIO_REQUEUE
)
934 if ((bio
->bi_rw
& REQ_FLUSH
) && bio
->bi_iter
.bi_size
) {
936 * Preflush done for flush with data, reissue
939 bio
->bi_rw
&= ~REQ_FLUSH
;
942 /* done with normal IO or empty flush */
943 trace_block_bio_complete(md
->queue
, bio
, io_error
);
944 bio_endio(bio
, io_error
);
949 static void disable_write_same(struct mapped_device
*md
)
951 struct queue_limits
*limits
= dm_get_queue_limits(md
);
953 /* device doesn't really support WRITE SAME, disable it */
954 limits
->max_write_same_sectors
= 0;
957 static void clone_endio(struct bio
*bio
, int error
)
960 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
961 struct dm_io
*io
= tio
->io
;
962 struct mapped_device
*md
= tio
->io
->md
;
963 dm_endio_fn endio
= tio
->ti
->type
->end_io
;
965 if (!bio_flagged(bio
, BIO_UPTODATE
) && !error
)
969 r
= endio(tio
->ti
, bio
, error
);
970 if (r
< 0 || r
== DM_ENDIO_REQUEUE
)
972 * error and requeue request are handled
976 else if (r
== DM_ENDIO_INCOMPLETE
)
977 /* The target will handle the io */
980 DMWARN("unimplemented target endio return value: %d", r
);
985 if (unlikely(r
== -EREMOTEIO
&& (bio
->bi_rw
& REQ_WRITE_SAME
) &&
986 !bdev_get_queue(bio
->bi_bdev
)->limits
.max_write_same_sectors
))
987 disable_write_same(md
);
990 dec_pending(io
, error
);
994 * Partial completion handling for request-based dm
996 static void end_clone_bio(struct bio
*clone
, int error
)
998 struct dm_rq_clone_bio_info
*info
=
999 container_of(clone
, struct dm_rq_clone_bio_info
, clone
);
1000 struct dm_rq_target_io
*tio
= info
->tio
;
1001 struct bio
*bio
= info
->orig
;
1002 unsigned int nr_bytes
= info
->orig
->bi_iter
.bi_size
;
1008 * An error has already been detected on the request.
1009 * Once error occurred, just let clone->end_io() handle
1015 * Don't notice the error to the upper layer yet.
1016 * The error handling decision is made by the target driver,
1017 * when the request is completed.
1024 * I/O for the bio successfully completed.
1025 * Notice the data completion to the upper layer.
1029 * bios are processed from the head of the list.
1030 * So the completing bio should always be rq->bio.
1031 * If it's not, something wrong is happening.
1033 if (tio
->orig
->bio
!= bio
)
1034 DMERR("bio completion is going in the middle of the request");
1037 * Update the original request.
1038 * Do not use blk_end_request() here, because it may complete
1039 * the original request before the clone, and break the ordering.
1041 blk_update_request(tio
->orig
, 0, nr_bytes
);
1044 static struct dm_rq_target_io
*tio_from_request(struct request
*rq
)
1046 return (rq
->q
->mq_ops
? blk_mq_rq_to_pdu(rq
) : rq
->special
);
1050 * Don't touch any member of the md after calling this function because
1051 * the md may be freed in dm_put() at the end of this function.
1052 * Or do dm_get() before calling this function and dm_put() later.
1054 static void rq_completed(struct mapped_device
*md
, int rw
, bool run_queue
)
1056 int nr_requests_pending
;
1058 atomic_dec(&md
->pending
[rw
]);
1060 /* nudge anyone waiting on suspend queue */
1061 nr_requests_pending
= md_in_flight(md
);
1062 if (!nr_requests_pending
)
1066 * Run this off this callpath, as drivers could invoke end_io while
1067 * inside their request_fn (and holding the queue lock). Calling
1068 * back into ->request_fn() could deadlock attempting to grab the
1072 if (md
->queue
->mq_ops
)
1073 blk_mq_run_hw_queues(md
->queue
, true);
1074 else if (!nr_requests_pending
||
1075 (nr_requests_pending
>= md
->queue
->nr_congestion_on
))
1076 blk_run_queue_async(md
->queue
);
1080 * dm_put() must be at the end of this function. See the comment above
1085 static void free_rq_clone(struct request
*clone
, bool must_be_mapped
)
1087 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1088 struct mapped_device
*md
= tio
->md
;
1090 WARN_ON_ONCE(must_be_mapped
&& !clone
->q
);
1092 blk_rq_unprep_clone(clone
);
1094 if (md
->type
== DM_TYPE_MQ_REQUEST_BASED
)
1095 /* stacked on blk-mq queue(s) */
1096 tio
->ti
->type
->release_clone_rq(clone
);
1097 else if (!md
->queue
->mq_ops
)
1098 /* request_fn queue stacked on request_fn queue(s) */
1099 free_clone_request(md
, clone
);
1101 * NOTE: for the blk-mq queue stacked on request_fn queue(s) case:
1102 * no need to call free_clone_request() because we leverage blk-mq by
1103 * allocating the clone at the end of the blk-mq pdu (see: clone_rq)
1106 if (!md
->queue
->mq_ops
)
1111 * Complete the clone and the original request.
1112 * Must be called without clone's queue lock held,
1113 * see end_clone_request() for more details.
1115 static void dm_end_request(struct request
*clone
, int error
)
1117 int rw
= rq_data_dir(clone
);
1118 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1119 struct mapped_device
*md
= tio
->md
;
1120 struct request
*rq
= tio
->orig
;
1122 if (rq
->cmd_type
== REQ_TYPE_BLOCK_PC
) {
1123 rq
->errors
= clone
->errors
;
1124 rq
->resid_len
= clone
->resid_len
;
1128 * We are using the sense buffer of the original
1130 * So setting the length of the sense data is enough.
1132 rq
->sense_len
= clone
->sense_len
;
1135 free_rq_clone(clone
, true);
1137 blk_end_request_all(rq
, error
);
1139 blk_mq_end_request(rq
, error
);
1140 rq_completed(md
, rw
, true);
1143 static void dm_unprep_request(struct request
*rq
)
1145 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
1146 struct request
*clone
= tio
->clone
;
1148 if (!rq
->q
->mq_ops
) {
1150 rq
->cmd_flags
&= ~REQ_DONTPREP
;
1154 free_rq_clone(clone
, false);
1158 * Requeue the original request of a clone.
1160 static void old_requeue_request(struct request
*rq
)
1162 struct request_queue
*q
= rq
->q
;
1163 unsigned long flags
;
1165 spin_lock_irqsave(q
->queue_lock
, flags
);
1166 blk_requeue_request(q
, rq
);
1167 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1170 static void dm_requeue_unmapped_original_request(struct mapped_device
*md
,
1173 int rw
= rq_data_dir(rq
);
1175 dm_unprep_request(rq
);
1178 old_requeue_request(rq
);
1180 blk_mq_requeue_request(rq
);
1181 blk_mq_kick_requeue_list(rq
->q
);
1184 rq_completed(md
, rw
, false);
1187 static void dm_requeue_unmapped_request(struct request
*clone
)
1189 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1191 dm_requeue_unmapped_original_request(tio
->md
, tio
->orig
);
1194 static void old_stop_queue(struct request_queue
*q
)
1196 unsigned long flags
;
1198 if (blk_queue_stopped(q
))
1201 spin_lock_irqsave(q
->queue_lock
, flags
);
1203 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1206 static void stop_queue(struct request_queue
*q
)
1211 blk_mq_stop_hw_queues(q
);
1214 static void old_start_queue(struct request_queue
*q
)
1216 unsigned long flags
;
1218 spin_lock_irqsave(q
->queue_lock
, flags
);
1219 if (blk_queue_stopped(q
))
1221 spin_unlock_irqrestore(q
->queue_lock
, flags
);
1224 static void start_queue(struct request_queue
*q
)
1229 blk_mq_start_stopped_hw_queues(q
, true);
1232 static void dm_done(struct request
*clone
, int error
, bool mapped
)
1235 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1236 dm_request_endio_fn rq_end_io
= NULL
;
1239 rq_end_io
= tio
->ti
->type
->rq_end_io
;
1241 if (mapped
&& rq_end_io
)
1242 r
= rq_end_io(tio
->ti
, clone
, error
, &tio
->info
);
1245 if (unlikely(r
== -EREMOTEIO
&& (clone
->cmd_flags
& REQ_WRITE_SAME
) &&
1246 !clone
->q
->limits
.max_write_same_sectors
))
1247 disable_write_same(tio
->md
);
1250 /* The target wants to complete the I/O */
1251 dm_end_request(clone
, r
);
1252 else if (r
== DM_ENDIO_INCOMPLETE
)
1253 /* The target will handle the I/O */
1255 else if (r
== DM_ENDIO_REQUEUE
)
1256 /* The target wants to requeue the I/O */
1257 dm_requeue_unmapped_request(clone
);
1259 DMWARN("unimplemented target endio return value: %d", r
);
1265 * Request completion handler for request-based dm
1267 static void dm_softirq_done(struct request
*rq
)
1270 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
1271 struct request
*clone
= tio
->clone
;
1275 rw
= rq_data_dir(rq
);
1276 if (!rq
->q
->mq_ops
) {
1277 blk_end_request_all(rq
, tio
->error
);
1278 rq_completed(tio
->md
, rw
, false);
1281 blk_mq_end_request(rq
, tio
->error
);
1282 rq_completed(tio
->md
, rw
, false);
1287 if (rq
->cmd_flags
& REQ_FAILED
)
1290 dm_done(clone
, tio
->error
, mapped
);
1294 * Complete the clone and the original request with the error status
1295 * through softirq context.
1297 static void dm_complete_request(struct request
*rq
, int error
)
1299 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
1302 blk_complete_request(rq
);
1306 * Complete the not-mapped clone and the original request with the error status
1307 * through softirq context.
1308 * Target's rq_end_io() function isn't called.
1309 * This may be used when the target's map_rq() or clone_and_map_rq() functions fail.
1311 static void dm_kill_unmapped_request(struct request
*rq
, int error
)
1313 rq
->cmd_flags
|= REQ_FAILED
;
1314 dm_complete_request(rq
, error
);
1318 * Called with the clone's queue lock held (for non-blk-mq)
1320 static void end_clone_request(struct request
*clone
, int error
)
1322 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
1324 if (!clone
->q
->mq_ops
) {
1326 * For just cleaning up the information of the queue in which
1327 * the clone was dispatched.
1328 * The clone is *NOT* freed actually here because it is alloced
1329 * from dm own mempool (REQ_ALLOCED isn't set).
1331 __blk_put_request(clone
->q
, clone
);
1335 * Actual request completion is done in a softirq context which doesn't
1336 * hold the clone's queue lock. Otherwise, deadlock could occur because:
1337 * - another request may be submitted by the upper level driver
1338 * of the stacking during the completion
1339 * - the submission which requires queue lock may be done
1340 * against this clone's queue
1342 dm_complete_request(tio
->orig
, error
);
1346 * Return maximum size of I/O possible at the supplied sector up to the current
1349 static sector_t
max_io_len_target_boundary(sector_t sector
, struct dm_target
*ti
)
1351 sector_t target_offset
= dm_target_offset(ti
, sector
);
1353 return ti
->len
- target_offset
;
1356 static sector_t
max_io_len(sector_t sector
, struct dm_target
*ti
)
1358 sector_t len
= max_io_len_target_boundary(sector
, ti
);
1359 sector_t offset
, max_len
;
1362 * Does the target need to split even further?
1364 if (ti
->max_io_len
) {
1365 offset
= dm_target_offset(ti
, sector
);
1366 if (unlikely(ti
->max_io_len
& (ti
->max_io_len
- 1)))
1367 max_len
= sector_div(offset
, ti
->max_io_len
);
1369 max_len
= offset
& (ti
->max_io_len
- 1);
1370 max_len
= ti
->max_io_len
- max_len
;
1379 int dm_set_target_max_io_len(struct dm_target
*ti
, sector_t len
)
1381 if (len
> UINT_MAX
) {
1382 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1383 (unsigned long long)len
, UINT_MAX
);
1384 ti
->error
= "Maximum size of target IO is too large";
1388 ti
->max_io_len
= (uint32_t) len
;
1392 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len
);
1395 * A target may call dm_accept_partial_bio only from the map routine. It is
1396 * allowed for all bio types except REQ_FLUSH.
1398 * dm_accept_partial_bio informs the dm that the target only wants to process
1399 * additional n_sectors sectors of the bio and the rest of the data should be
1400 * sent in a next bio.
1402 * A diagram that explains the arithmetics:
1403 * +--------------------+---------------+-------+
1405 * +--------------------+---------------+-------+
1407 * <-------------- *tio->len_ptr --------------->
1408 * <------- bi_size ------->
1411 * Region 1 was already iterated over with bio_advance or similar function.
1412 * (it may be empty if the target doesn't use bio_advance)
1413 * Region 2 is the remaining bio size that the target wants to process.
1414 * (it may be empty if region 1 is non-empty, although there is no reason
1416 * The target requires that region 3 is to be sent in the next bio.
1418 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1419 * the partially processed part (the sum of regions 1+2) must be the same for all
1420 * copies of the bio.
1422 void dm_accept_partial_bio(struct bio
*bio
, unsigned n_sectors
)
1424 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
1425 unsigned bi_size
= bio
->bi_iter
.bi_size
>> SECTOR_SHIFT
;
1426 BUG_ON(bio
->bi_rw
& REQ_FLUSH
);
1427 BUG_ON(bi_size
> *tio
->len_ptr
);
1428 BUG_ON(n_sectors
> bi_size
);
1429 *tio
->len_ptr
-= bi_size
- n_sectors
;
1430 bio
->bi_iter
.bi_size
= n_sectors
<< SECTOR_SHIFT
;
1432 EXPORT_SYMBOL_GPL(dm_accept_partial_bio
);
1434 static void __map_bio(struct dm_target_io
*tio
)
1438 struct mapped_device
*md
;
1439 struct bio
*clone
= &tio
->clone
;
1440 struct dm_target
*ti
= tio
->ti
;
1442 clone
->bi_end_io
= clone_endio
;
1445 * Map the clone. If r == 0 we don't need to do
1446 * anything, the target has assumed ownership of
1449 atomic_inc(&tio
->io
->io_count
);
1450 sector
= clone
->bi_iter
.bi_sector
;
1451 r
= ti
->type
->map(ti
, clone
);
1452 if (r
== DM_MAPIO_REMAPPED
) {
1453 /* the bio has been remapped so dispatch it */
1455 trace_block_bio_remap(bdev_get_queue(clone
->bi_bdev
), clone
,
1456 tio
->io
->bio
->bi_bdev
->bd_dev
, sector
);
1458 generic_make_request(clone
);
1459 } else if (r
< 0 || r
== DM_MAPIO_REQUEUE
) {
1460 /* error the io and bail out, or requeue it if needed */
1462 dec_pending(tio
->io
, r
);
1465 DMWARN("unimplemented target map return value: %d", r
);
1471 struct mapped_device
*md
;
1472 struct dm_table
*map
;
1476 unsigned sector_count
;
1479 static void bio_setup_sector(struct bio
*bio
, sector_t sector
, unsigned len
)
1481 bio
->bi_iter
.bi_sector
= sector
;
1482 bio
->bi_iter
.bi_size
= to_bytes(len
);
1486 * Creates a bio that consists of range of complete bvecs.
1488 static void clone_bio(struct dm_target_io
*tio
, struct bio
*bio
,
1489 sector_t sector
, unsigned len
)
1491 struct bio
*clone
= &tio
->clone
;
1493 __bio_clone_fast(clone
, bio
);
1495 if (bio_integrity(bio
))
1496 bio_integrity_clone(clone
, bio
, GFP_NOIO
);
1498 bio_advance(clone
, to_bytes(sector
- clone
->bi_iter
.bi_sector
));
1499 clone
->bi_iter
.bi_size
= to_bytes(len
);
1501 if (bio_integrity(bio
))
1502 bio_integrity_trim(clone
, 0, len
);
1505 static struct dm_target_io
*alloc_tio(struct clone_info
*ci
,
1506 struct dm_target
*ti
,
1507 unsigned target_bio_nr
)
1509 struct dm_target_io
*tio
;
1512 clone
= bio_alloc_bioset(GFP_NOIO
, 0, ci
->md
->bs
);
1513 tio
= container_of(clone
, struct dm_target_io
, clone
);
1517 tio
->target_bio_nr
= target_bio_nr
;
1522 static void __clone_and_map_simple_bio(struct clone_info
*ci
,
1523 struct dm_target
*ti
,
1524 unsigned target_bio_nr
, unsigned *len
)
1526 struct dm_target_io
*tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1527 struct bio
*clone
= &tio
->clone
;
1531 __bio_clone_fast(clone
, ci
->bio
);
1533 bio_setup_sector(clone
, ci
->sector
, *len
);
1538 static void __send_duplicate_bios(struct clone_info
*ci
, struct dm_target
*ti
,
1539 unsigned num_bios
, unsigned *len
)
1541 unsigned target_bio_nr
;
1543 for (target_bio_nr
= 0; target_bio_nr
< num_bios
; target_bio_nr
++)
1544 __clone_and_map_simple_bio(ci
, ti
, target_bio_nr
, len
);
1547 static int __send_empty_flush(struct clone_info
*ci
)
1549 unsigned target_nr
= 0;
1550 struct dm_target
*ti
;
1552 BUG_ON(bio_has_data(ci
->bio
));
1553 while ((ti
= dm_table_get_target(ci
->map
, target_nr
++)))
1554 __send_duplicate_bios(ci
, ti
, ti
->num_flush_bios
, NULL
);
1559 static void __clone_and_map_data_bio(struct clone_info
*ci
, struct dm_target
*ti
,
1560 sector_t sector
, unsigned *len
)
1562 struct bio
*bio
= ci
->bio
;
1563 struct dm_target_io
*tio
;
1564 unsigned target_bio_nr
;
1565 unsigned num_target_bios
= 1;
1568 * Does the target want to receive duplicate copies of the bio?
1570 if (bio_data_dir(bio
) == WRITE
&& ti
->num_write_bios
)
1571 num_target_bios
= ti
->num_write_bios(ti
, bio
);
1573 for (target_bio_nr
= 0; target_bio_nr
< num_target_bios
; target_bio_nr
++) {
1574 tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1576 clone_bio(tio
, bio
, sector
, *len
);
1581 typedef unsigned (*get_num_bios_fn
)(struct dm_target
*ti
);
1583 static unsigned get_num_discard_bios(struct dm_target
*ti
)
1585 return ti
->num_discard_bios
;
1588 static unsigned get_num_write_same_bios(struct dm_target
*ti
)
1590 return ti
->num_write_same_bios
;
1593 typedef bool (*is_split_required_fn
)(struct dm_target
*ti
);
1595 static bool is_split_required_for_discard(struct dm_target
*ti
)
1597 return ti
->split_discard_bios
;
1600 static int __send_changing_extent_only(struct clone_info
*ci
,
1601 get_num_bios_fn get_num_bios
,
1602 is_split_required_fn is_split_required
)
1604 struct dm_target
*ti
;
1609 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1610 if (!dm_target_is_valid(ti
))
1614 * Even though the device advertised support for this type of
1615 * request, that does not mean every target supports it, and
1616 * reconfiguration might also have changed that since the
1617 * check was performed.
1619 num_bios
= get_num_bios
? get_num_bios(ti
) : 0;
1623 if (is_split_required
&& !is_split_required(ti
))
1624 len
= min((sector_t
)ci
->sector_count
, max_io_len_target_boundary(ci
->sector
, ti
));
1626 len
= min((sector_t
)ci
->sector_count
, max_io_len(ci
->sector
, ti
));
1628 __send_duplicate_bios(ci
, ti
, num_bios
, &len
);
1631 } while (ci
->sector_count
-= len
);
1636 static int __send_discard(struct clone_info
*ci
)
1638 return __send_changing_extent_only(ci
, get_num_discard_bios
,
1639 is_split_required_for_discard
);
1642 static int __send_write_same(struct clone_info
*ci
)
1644 return __send_changing_extent_only(ci
, get_num_write_same_bios
, NULL
);
1648 * Select the correct strategy for processing a non-flush bio.
1650 static int __split_and_process_non_flush(struct clone_info
*ci
)
1652 struct bio
*bio
= ci
->bio
;
1653 struct dm_target
*ti
;
1656 if (unlikely(bio
->bi_rw
& REQ_DISCARD
))
1657 return __send_discard(ci
);
1658 else if (unlikely(bio
->bi_rw
& REQ_WRITE_SAME
))
1659 return __send_write_same(ci
);
1661 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1662 if (!dm_target_is_valid(ti
))
1665 len
= min_t(sector_t
, max_io_len(ci
->sector
, ti
), ci
->sector_count
);
1667 __clone_and_map_data_bio(ci
, ti
, ci
->sector
, &len
);
1670 ci
->sector_count
-= len
;
1676 * Entry point to split a bio into clones and submit them to the targets.
1678 static void __split_and_process_bio(struct mapped_device
*md
,
1679 struct dm_table
*map
, struct bio
*bio
)
1681 struct clone_info ci
;
1684 if (unlikely(!map
)) {
1691 ci
.io
= alloc_io(md
);
1693 atomic_set(&ci
.io
->io_count
, 1);
1696 spin_lock_init(&ci
.io
->endio_lock
);
1697 ci
.sector
= bio
->bi_iter
.bi_sector
;
1699 start_io_acct(ci
.io
);
1701 if (bio
->bi_rw
& REQ_FLUSH
) {
1702 ci
.bio
= &ci
.md
->flush_bio
;
1703 ci
.sector_count
= 0;
1704 error
= __send_empty_flush(&ci
);
1705 /* dec_pending submits any data associated with flush */
1708 ci
.sector_count
= bio_sectors(bio
);
1709 while (ci
.sector_count
&& !error
)
1710 error
= __split_and_process_non_flush(&ci
);
1713 /* drop the extra reference count */
1714 dec_pending(ci
.io
, error
);
1716 /*-----------------------------------------------------------------
1718 *---------------------------------------------------------------*/
1720 static int dm_merge_bvec(struct request_queue
*q
,
1721 struct bvec_merge_data
*bvm
,
1722 struct bio_vec
*biovec
)
1724 struct mapped_device
*md
= q
->queuedata
;
1725 struct dm_table
*map
= dm_get_live_table_fast(md
);
1726 struct dm_target
*ti
;
1727 sector_t max_sectors
;
1733 ti
= dm_table_find_target(map
, bvm
->bi_sector
);
1734 if (!dm_target_is_valid(ti
))
1738 * Find maximum amount of I/O that won't need splitting
1740 max_sectors
= min(max_io_len(bvm
->bi_sector
, ti
),
1741 (sector_t
) queue_max_sectors(q
));
1742 max_size
= (max_sectors
<< SECTOR_SHIFT
) - bvm
->bi_size
;
1743 if (unlikely(max_size
< 0)) /* this shouldn't _ever_ happen */
1747 * merge_bvec_fn() returns number of bytes
1748 * it can accept at this offset
1749 * max is precomputed maximal io size
1751 if (max_size
&& ti
->type
->merge
)
1752 max_size
= ti
->type
->merge(ti
, bvm
, biovec
, max_size
);
1754 * If the target doesn't support merge method and some of the devices
1755 * provided their merge_bvec method (we know this by looking for the
1756 * max_hw_sectors that dm_set_device_limits may set), then we can't
1757 * allow bios with multiple vector entries. So always set max_size
1758 * to 0, and the code below allows just one page.
1760 else if (queue_max_hw_sectors(q
) <= PAGE_SIZE
>> 9)
1764 dm_put_live_table_fast(md
);
1766 * Always allow an entire first page
1768 if (max_size
<= biovec
->bv_len
&& !(bvm
->bi_size
>> SECTOR_SHIFT
))
1769 max_size
= biovec
->bv_len
;
1775 * The request function that just remaps the bio built up by
1778 static void dm_make_request(struct request_queue
*q
, struct bio
*bio
)
1780 int rw
= bio_data_dir(bio
);
1781 struct mapped_device
*md
= q
->queuedata
;
1783 struct dm_table
*map
;
1785 map
= dm_get_live_table(md
, &srcu_idx
);
1787 generic_start_io_acct(rw
, bio_sectors(bio
), &dm_disk(md
)->part0
);
1789 /* if we're suspended, we have to queue this io for later */
1790 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))) {
1791 dm_put_live_table(md
, srcu_idx
);
1793 if (bio_rw(bio
) != READA
)
1800 __split_and_process_bio(md
, map
, bio
);
1801 dm_put_live_table(md
, srcu_idx
);
1805 int dm_request_based(struct mapped_device
*md
)
1807 return blk_queue_stackable(md
->queue
);
1810 static void dm_dispatch_clone_request(struct request
*clone
, struct request
*rq
)
1814 if (blk_queue_io_stat(clone
->q
))
1815 clone
->cmd_flags
|= REQ_IO_STAT
;
1817 clone
->start_time
= jiffies
;
1818 r
= blk_insert_cloned_request(clone
->q
, clone
);
1820 /* must complete clone in terms of original request */
1821 dm_complete_request(rq
, r
);
1824 static int dm_rq_bio_constructor(struct bio
*bio
, struct bio
*bio_orig
,
1827 struct dm_rq_target_io
*tio
= data
;
1828 struct dm_rq_clone_bio_info
*info
=
1829 container_of(bio
, struct dm_rq_clone_bio_info
, clone
);
1831 info
->orig
= bio_orig
;
1833 bio
->bi_end_io
= end_clone_bio
;
1838 static int setup_clone(struct request
*clone
, struct request
*rq
,
1839 struct dm_rq_target_io
*tio
, gfp_t gfp_mask
)
1843 r
= blk_rq_prep_clone(clone
, rq
, tio
->md
->bs
, gfp_mask
,
1844 dm_rq_bio_constructor
, tio
);
1848 clone
->cmd
= rq
->cmd
;
1849 clone
->cmd_len
= rq
->cmd_len
;
1850 clone
->sense
= rq
->sense
;
1851 clone
->end_io
= end_clone_request
;
1852 clone
->end_io_data
= tio
;
1859 static struct request
*clone_rq(struct request
*rq
, struct mapped_device
*md
,
1860 struct dm_rq_target_io
*tio
, gfp_t gfp_mask
)
1863 * Do not allocate a clone if tio->clone was already set
1864 * (see: dm_mq_queue_rq).
1866 bool alloc_clone
= !tio
->clone
;
1867 struct request
*clone
;
1870 clone
= alloc_clone_request(md
, gfp_mask
);
1876 blk_rq_init(NULL
, clone
);
1877 if (setup_clone(clone
, rq
, tio
, gfp_mask
)) {
1880 free_clone_request(md
, clone
);
1887 static void map_tio_request(struct kthread_work
*work
);
1889 static void init_tio(struct dm_rq_target_io
*tio
, struct request
*rq
,
1890 struct mapped_device
*md
)
1897 memset(&tio
->info
, 0, sizeof(tio
->info
));
1898 if (md
->kworker_task
)
1899 init_kthread_work(&tio
->work
, map_tio_request
);
1902 static struct dm_rq_target_io
*prep_tio(struct request
*rq
,
1903 struct mapped_device
*md
, gfp_t gfp_mask
)
1905 struct dm_rq_target_io
*tio
;
1907 struct dm_table
*table
;
1909 tio
= alloc_rq_tio(md
, gfp_mask
);
1913 init_tio(tio
, rq
, md
);
1915 table
= dm_get_live_table(md
, &srcu_idx
);
1916 if (!dm_table_mq_request_based(table
)) {
1917 if (!clone_rq(rq
, md
, tio
, gfp_mask
)) {
1918 dm_put_live_table(md
, srcu_idx
);
1923 dm_put_live_table(md
, srcu_idx
);
1929 * Called with the queue lock held.
1931 static int dm_prep_fn(struct request_queue
*q
, struct request
*rq
)
1933 struct mapped_device
*md
= q
->queuedata
;
1934 struct dm_rq_target_io
*tio
;
1936 if (unlikely(rq
->special
)) {
1937 DMWARN("Already has something in rq->special.");
1938 return BLKPREP_KILL
;
1941 tio
= prep_tio(rq
, md
, GFP_ATOMIC
);
1943 return BLKPREP_DEFER
;
1946 rq
->cmd_flags
|= REQ_DONTPREP
;
1953 * 0 : the request has been processed
1954 * DM_MAPIO_REQUEUE : the original request needs to be requeued
1955 * < 0 : the request was completed due to failure
1957 static int map_request(struct dm_rq_target_io
*tio
, struct request
*rq
,
1958 struct mapped_device
*md
)
1961 struct dm_target
*ti
= tio
->ti
;
1962 struct request
*clone
= NULL
;
1966 r
= ti
->type
->map_rq(ti
, clone
, &tio
->info
);
1968 r
= ti
->type
->clone_and_map_rq(ti
, rq
, &tio
->info
, &clone
);
1970 /* The target wants to complete the I/O */
1971 dm_kill_unmapped_request(rq
, r
);
1975 return DM_MAPIO_REQUEUE
;
1976 if (setup_clone(clone
, rq
, tio
, GFP_ATOMIC
)) {
1978 ti
->type
->release_clone_rq(clone
);
1979 return DM_MAPIO_REQUEUE
;
1984 case DM_MAPIO_SUBMITTED
:
1985 /* The target has taken the I/O to submit by itself later */
1987 case DM_MAPIO_REMAPPED
:
1988 /* The target has remapped the I/O so dispatch it */
1989 trace_block_rq_remap(clone
->q
, clone
, disk_devt(dm_disk(md
)),
1991 dm_dispatch_clone_request(clone
, rq
);
1993 case DM_MAPIO_REQUEUE
:
1994 /* The target wants to requeue the I/O */
1995 dm_requeue_unmapped_request(clone
);
1999 DMWARN("unimplemented target map return value: %d", r
);
2003 /* The target wants to complete the I/O */
2004 dm_kill_unmapped_request(rq
, r
);
2011 static void map_tio_request(struct kthread_work
*work
)
2013 struct dm_rq_target_io
*tio
= container_of(work
, struct dm_rq_target_io
, work
);
2014 struct request
*rq
= tio
->orig
;
2015 struct mapped_device
*md
= tio
->md
;
2017 if (map_request(tio
, rq
, md
) == DM_MAPIO_REQUEUE
)
2018 dm_requeue_unmapped_original_request(md
, rq
);
2021 static void dm_start_request(struct mapped_device
*md
, struct request
*orig
)
2023 if (!orig
->q
->mq_ops
)
2024 blk_start_request(orig
);
2026 blk_mq_start_request(orig
);
2027 atomic_inc(&md
->pending
[rq_data_dir(orig
)]);
2029 if (md
->seq_rq_merge_deadline_usecs
) {
2030 md
->last_rq_pos
= rq_end_sector(orig
);
2031 md
->last_rq_rw
= rq_data_dir(orig
);
2032 md
->last_rq_start_time
= ktime_get();
2036 * Hold the md reference here for the in-flight I/O.
2037 * We can't rely on the reference count by device opener,
2038 * because the device may be closed during the request completion
2039 * when all bios are completed.
2040 * See the comment in rq_completed() too.
2045 #define MAX_SEQ_RQ_MERGE_DEADLINE_USECS 100000
2047 ssize_t
dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device
*md
, char *buf
)
2049 return sprintf(buf
, "%u\n", md
->seq_rq_merge_deadline_usecs
);
2052 ssize_t
dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device
*md
,
2053 const char *buf
, size_t count
)
2057 if (!dm_request_based(md
) || md
->use_blk_mq
)
2060 if (kstrtouint(buf
, 10, &deadline
))
2063 if (deadline
> MAX_SEQ_RQ_MERGE_DEADLINE_USECS
)
2064 deadline
= MAX_SEQ_RQ_MERGE_DEADLINE_USECS
;
2066 md
->seq_rq_merge_deadline_usecs
= deadline
;
2071 static bool dm_request_peeked_before_merge_deadline(struct mapped_device
*md
)
2073 ktime_t kt_deadline
;
2075 if (!md
->seq_rq_merge_deadline_usecs
)
2078 kt_deadline
= ns_to_ktime((u64
)md
->seq_rq_merge_deadline_usecs
* NSEC_PER_USEC
);
2079 kt_deadline
= ktime_add_safe(md
->last_rq_start_time
, kt_deadline
);
2081 return !ktime_after(ktime_get(), kt_deadline
);
2085 * q->request_fn for request-based dm.
2086 * Called with the queue lock held.
2088 static void dm_request_fn(struct request_queue
*q
)
2090 struct mapped_device
*md
= q
->queuedata
;
2092 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
2093 struct dm_target
*ti
;
2095 struct dm_rq_target_io
*tio
;
2099 * For suspend, check blk_queue_stopped() and increment
2100 * ->pending within a single queue_lock not to increment the
2101 * number of in-flight I/Os after the queue is stopped in
2104 while (!blk_queue_stopped(q
)) {
2105 rq
= blk_peek_request(q
);
2109 /* always use block 0 to find the target for flushes for now */
2111 if (!(rq
->cmd_flags
& REQ_FLUSH
))
2112 pos
= blk_rq_pos(rq
);
2114 ti
= dm_table_find_target(map
, pos
);
2115 if (!dm_target_is_valid(ti
)) {
2117 * Must perform setup, that rq_completed() requires,
2118 * before calling dm_kill_unmapped_request
2120 DMERR_LIMIT("request attempted access beyond the end of device");
2121 dm_start_request(md
, rq
);
2122 dm_kill_unmapped_request(rq
, -EIO
);
2126 if (dm_request_peeked_before_merge_deadline(md
) &&
2127 md_in_flight(md
) && rq
->bio
&& rq
->bio
->bi_vcnt
== 1 &&
2128 md
->last_rq_pos
== pos
&& md
->last_rq_rw
== rq_data_dir(rq
))
2131 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
2134 dm_start_request(md
, rq
);
2136 tio
= tio_from_request(rq
);
2137 /* Establish tio->ti before queuing work (map_tio_request) */
2139 queue_kthread_work(&md
->kworker
, &tio
->work
);
2140 BUG_ON(!irqs_disabled());
2146 blk_delay_queue(q
, HZ
/ 100);
2148 dm_put_live_table(md
, srcu_idx
);
2151 static int dm_any_congested(void *congested_data
, int bdi_bits
)
2154 struct mapped_device
*md
= congested_data
;
2155 struct dm_table
*map
;
2157 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
2158 map
= dm_get_live_table_fast(md
);
2161 * Request-based dm cares about only own queue for
2162 * the query about congestion status of request_queue
2164 if (dm_request_based(md
))
2165 r
= md
->queue
->backing_dev_info
.state
&
2168 r
= dm_table_any_congested(map
, bdi_bits
);
2170 dm_put_live_table_fast(md
);
2176 /*-----------------------------------------------------------------
2177 * An IDR is used to keep track of allocated minor numbers.
2178 *---------------------------------------------------------------*/
2179 static void free_minor(int minor
)
2181 spin_lock(&_minor_lock
);
2182 idr_remove(&_minor_idr
, minor
);
2183 spin_unlock(&_minor_lock
);
2187 * See if the device with a specific minor # is free.
2189 static int specific_minor(int minor
)
2193 if (minor
>= (1 << MINORBITS
))
2196 idr_preload(GFP_KERNEL
);
2197 spin_lock(&_minor_lock
);
2199 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, minor
, minor
+ 1, GFP_NOWAIT
);
2201 spin_unlock(&_minor_lock
);
2204 return r
== -ENOSPC
? -EBUSY
: r
;
2208 static int next_free_minor(int *minor
)
2212 idr_preload(GFP_KERNEL
);
2213 spin_lock(&_minor_lock
);
2215 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, 0, 1 << MINORBITS
, GFP_NOWAIT
);
2217 spin_unlock(&_minor_lock
);
2225 static const struct block_device_operations dm_blk_dops
;
2227 static void dm_wq_work(struct work_struct
*work
);
2229 static void dm_init_md_queue(struct mapped_device
*md
)
2232 * Request-based dm devices cannot be stacked on top of bio-based dm
2233 * devices. The type of this dm device may not have been decided yet.
2234 * The type is decided at the first table loading time.
2235 * To prevent problematic device stacking, clear the queue flag
2236 * for request stacking support until then.
2238 * This queue is new, so no concurrency on the queue_flags.
2240 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE
, md
->queue
);
2243 static void dm_init_old_md_queue(struct mapped_device
*md
)
2245 md
->use_blk_mq
= false;
2246 dm_init_md_queue(md
);
2249 * Initialize aspects of queue that aren't relevant for blk-mq
2251 md
->queue
->queuedata
= md
;
2252 md
->queue
->backing_dev_info
.congested_fn
= dm_any_congested
;
2253 md
->queue
->backing_dev_info
.congested_data
= md
;
2255 blk_queue_bounce_limit(md
->queue
, BLK_BOUNCE_ANY
);
2259 * Allocate and initialise a blank device with a given minor.
2261 static struct mapped_device
*alloc_dev(int minor
)
2264 struct mapped_device
*md
= kzalloc(sizeof(*md
), GFP_KERNEL
);
2268 DMWARN("unable to allocate device, out of memory.");
2272 if (!try_module_get(THIS_MODULE
))
2273 goto bad_module_get
;
2275 /* get a minor number for the dev */
2276 if (minor
== DM_ANY_MINOR
)
2277 r
= next_free_minor(&minor
);
2279 r
= specific_minor(minor
);
2283 r
= init_srcu_struct(&md
->io_barrier
);
2285 goto bad_io_barrier
;
2287 md
->use_blk_mq
= use_blk_mq
;
2288 md
->type
= DM_TYPE_NONE
;
2289 mutex_init(&md
->suspend_lock
);
2290 mutex_init(&md
->type_lock
);
2291 mutex_init(&md
->table_devices_lock
);
2292 spin_lock_init(&md
->deferred_lock
);
2293 atomic_set(&md
->holders
, 1);
2294 atomic_set(&md
->open_count
, 0);
2295 atomic_set(&md
->event_nr
, 0);
2296 atomic_set(&md
->uevent_seq
, 0);
2297 INIT_LIST_HEAD(&md
->uevent_list
);
2298 INIT_LIST_HEAD(&md
->table_devices
);
2299 spin_lock_init(&md
->uevent_lock
);
2301 md
->queue
= blk_alloc_queue(GFP_KERNEL
);
2305 dm_init_md_queue(md
);
2307 md
->disk
= alloc_disk(1);
2311 atomic_set(&md
->pending
[0], 0);
2312 atomic_set(&md
->pending
[1], 0);
2313 init_waitqueue_head(&md
->wait
);
2314 INIT_WORK(&md
->work
, dm_wq_work
);
2315 init_waitqueue_head(&md
->eventq
);
2316 init_completion(&md
->kobj_holder
.completion
);
2317 md
->kworker_task
= NULL
;
2319 md
->disk
->major
= _major
;
2320 md
->disk
->first_minor
= minor
;
2321 md
->disk
->fops
= &dm_blk_dops
;
2322 md
->disk
->queue
= md
->queue
;
2323 md
->disk
->private_data
= md
;
2324 sprintf(md
->disk
->disk_name
, "dm-%d", minor
);
2326 format_dev_t(md
->name
, MKDEV(_major
, minor
));
2328 md
->wq
= alloc_workqueue("kdmflush", WQ_MEM_RECLAIM
, 0);
2332 md
->bdev
= bdget_disk(md
->disk
, 0);
2336 bio_init(&md
->flush_bio
);
2337 md
->flush_bio
.bi_bdev
= md
->bdev
;
2338 md
->flush_bio
.bi_rw
= WRITE_FLUSH
;
2340 dm_stats_init(&md
->stats
);
2342 /* Populate the mapping, nobody knows we exist yet */
2343 spin_lock(&_minor_lock
);
2344 old_md
= idr_replace(&_minor_idr
, md
, minor
);
2345 spin_unlock(&_minor_lock
);
2347 BUG_ON(old_md
!= MINOR_ALLOCED
);
2352 destroy_workqueue(md
->wq
);
2354 del_gendisk(md
->disk
);
2357 blk_cleanup_queue(md
->queue
);
2359 cleanup_srcu_struct(&md
->io_barrier
);
2363 module_put(THIS_MODULE
);
2369 static void unlock_fs(struct mapped_device
*md
);
2371 static void free_dev(struct mapped_device
*md
)
2373 int minor
= MINOR(disk_devt(md
->disk
));
2376 destroy_workqueue(md
->wq
);
2378 if (md
->kworker_task
)
2379 kthread_stop(md
->kworker_task
);
2381 mempool_destroy(md
->io_pool
);
2383 mempool_destroy(md
->rq_pool
);
2385 bioset_free(md
->bs
);
2387 cleanup_srcu_struct(&md
->io_barrier
);
2388 free_table_devices(&md
->table_devices
);
2389 dm_stats_cleanup(&md
->stats
);
2391 spin_lock(&_minor_lock
);
2392 md
->disk
->private_data
= NULL
;
2393 spin_unlock(&_minor_lock
);
2394 if (blk_get_integrity(md
->disk
))
2395 blk_integrity_unregister(md
->disk
);
2396 del_gendisk(md
->disk
);
2398 blk_cleanup_queue(md
->queue
);
2400 blk_mq_free_tag_set(&md
->tag_set
);
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 * Return 1 if the queue has a compulsory merge_bvec_fn function.
2480 * If this function returns 0, then the device is either a non-dm
2481 * device without a merge_bvec_fn, or it is a dm device that is
2482 * able to split any bios it receives that are too big.
2484 int dm_queue_merge_is_compulsory(struct request_queue
*q
)
2486 struct mapped_device
*dev_md
;
2488 if (!q
->merge_bvec_fn
)
2491 if (q
->make_request_fn
== dm_make_request
) {
2492 dev_md
= q
->queuedata
;
2493 if (test_bit(DMF_MERGE_IS_OPTIONAL
, &dev_md
->flags
))
2500 static int dm_device_merge_is_compulsory(struct dm_target
*ti
,
2501 struct dm_dev
*dev
, sector_t start
,
2502 sector_t len
, void *data
)
2504 struct block_device
*bdev
= dev
->bdev
;
2505 struct request_queue
*q
= bdev_get_queue(bdev
);
2507 return dm_queue_merge_is_compulsory(q
);
2511 * Return 1 if it is acceptable to ignore merge_bvec_fn based
2512 * on the properties of the underlying devices.
2514 static int dm_table_merge_is_optional(struct dm_table
*table
)
2517 struct dm_target
*ti
;
2519 while (i
< dm_table_get_num_targets(table
)) {
2520 ti
= dm_table_get_target(table
, i
++);
2522 if (ti
->type
->iterate_devices
&&
2523 ti
->type
->iterate_devices(ti
, dm_device_merge_is_compulsory
, NULL
))
2531 * Returns old map, which caller must destroy.
2533 static struct dm_table
*__bind(struct mapped_device
*md
, struct dm_table
*t
,
2534 struct queue_limits
*limits
)
2536 struct dm_table
*old_map
;
2537 struct request_queue
*q
= md
->queue
;
2539 int merge_is_optional
;
2541 size
= dm_table_get_size(t
);
2544 * Wipe any geometry if the size of the table changed.
2546 if (size
!= dm_get_size(md
))
2547 memset(&md
->geometry
, 0, sizeof(md
->geometry
));
2549 __set_size(md
, size
);
2551 dm_table_event_callback(t
, event_callback
, md
);
2554 * The queue hasn't been stopped yet, if the old table type wasn't
2555 * for request-based during suspension. So stop it to prevent
2556 * I/O mapping before resume.
2557 * This must be done before setting the queue restrictions,
2558 * because request-based dm may be run just after the setting.
2560 if (dm_table_request_based(t
))
2563 __bind_mempools(md
, t
);
2565 merge_is_optional
= dm_table_merge_is_optional(t
);
2567 old_map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
2568 rcu_assign_pointer(md
->map
, t
);
2569 md
->immutable_target_type
= dm_table_get_immutable_target_type(t
);
2571 dm_table_set_restrictions(t
, q
, limits
);
2572 if (merge_is_optional
)
2573 set_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2575 clear_bit(DMF_MERGE_IS_OPTIONAL
, &md
->flags
);
2583 * Returns unbound table for the caller to free.
2585 static struct dm_table
*__unbind(struct mapped_device
*md
)
2587 struct dm_table
*map
= rcu_dereference_protected(md
->map
, 1);
2592 dm_table_event_callback(map
, NULL
, NULL
);
2593 RCU_INIT_POINTER(md
->map
, NULL
);
2600 * Constructor for a new device.
2602 int dm_create(int minor
, struct mapped_device
**result
)
2604 struct mapped_device
*md
;
2606 md
= alloc_dev(minor
);
2617 * Functions to manage md->type.
2618 * All are required to hold md->type_lock.
2620 void dm_lock_md_type(struct mapped_device
*md
)
2622 mutex_lock(&md
->type_lock
);
2625 void dm_unlock_md_type(struct mapped_device
*md
)
2627 mutex_unlock(&md
->type_lock
);
2630 void dm_set_md_type(struct mapped_device
*md
, unsigned type
)
2632 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2636 unsigned dm_get_md_type(struct mapped_device
*md
)
2638 BUG_ON(!mutex_is_locked(&md
->type_lock
));
2642 struct target_type
*dm_get_immutable_target_type(struct mapped_device
*md
)
2644 return md
->immutable_target_type
;
2648 * The queue_limits are only valid as long as you have a reference
2651 struct queue_limits
*dm_get_queue_limits(struct mapped_device
*md
)
2653 BUG_ON(!atomic_read(&md
->holders
));
2654 return &md
->queue
->limits
;
2656 EXPORT_SYMBOL_GPL(dm_get_queue_limits
);
2658 static void init_rq_based_worker_thread(struct mapped_device
*md
)
2660 /* Initialize the request-based DM worker thread */
2661 init_kthread_worker(&md
->kworker
);
2662 md
->kworker_task
= kthread_run(kthread_worker_fn
, &md
->kworker
,
2663 "kdmwork-%s", dm_device_name(md
));
2667 * Fully initialize a request-based queue (->elevator, ->request_fn, etc).
2669 static int dm_init_request_based_queue(struct mapped_device
*md
)
2671 struct request_queue
*q
= NULL
;
2673 /* Fully initialize the queue */
2674 q
= blk_init_allocated_queue(md
->queue
, dm_request_fn
, NULL
);
2678 /* disable dm_request_fn's merge heuristic by default */
2679 md
->seq_rq_merge_deadline_usecs
= 0;
2682 dm_init_old_md_queue(md
);
2683 blk_queue_softirq_done(md
->queue
, dm_softirq_done
);
2684 blk_queue_prep_rq(md
->queue
, dm_prep_fn
);
2686 init_rq_based_worker_thread(md
);
2688 elv_register_queue(md
->queue
);
2693 static int dm_mq_init_request(void *data
, struct request
*rq
,
2694 unsigned int hctx_idx
, unsigned int request_idx
,
2695 unsigned int numa_node
)
2697 struct mapped_device
*md
= data
;
2698 struct dm_rq_target_io
*tio
= blk_mq_rq_to_pdu(rq
);
2701 * Must initialize md member of tio, otherwise it won't
2702 * be available in dm_mq_queue_rq.
2709 static int dm_mq_queue_rq(struct blk_mq_hw_ctx
*hctx
,
2710 const struct blk_mq_queue_data
*bd
)
2712 struct request
*rq
= bd
->rq
;
2713 struct dm_rq_target_io
*tio
= blk_mq_rq_to_pdu(rq
);
2714 struct mapped_device
*md
= tio
->md
;
2716 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
2717 struct dm_target
*ti
;
2720 /* always use block 0 to find the target for flushes for now */
2722 if (!(rq
->cmd_flags
& REQ_FLUSH
))
2723 pos
= blk_rq_pos(rq
);
2725 ti
= dm_table_find_target(map
, pos
);
2726 if (!dm_target_is_valid(ti
)) {
2727 dm_put_live_table(md
, srcu_idx
);
2728 DMERR_LIMIT("request attempted access beyond the end of device");
2730 * Must perform setup, that rq_completed() requires,
2731 * before returning BLK_MQ_RQ_QUEUE_ERROR
2733 dm_start_request(md
, rq
);
2734 return BLK_MQ_RQ_QUEUE_ERROR
;
2736 dm_put_live_table(md
, srcu_idx
);
2738 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
2739 return BLK_MQ_RQ_QUEUE_BUSY
;
2741 dm_start_request(md
, rq
);
2743 /* Init tio using md established in .init_request */
2744 init_tio(tio
, rq
, md
);
2747 * Establish tio->ti before queuing work (map_tio_request)
2748 * or making direct call to map_request().
2752 /* Clone the request if underlying devices aren't blk-mq */
2753 if (dm_table_get_type(map
) == DM_TYPE_REQUEST_BASED
) {
2754 /* clone request is allocated at the end of the pdu */
2755 tio
->clone
= (void *)blk_mq_rq_to_pdu(rq
) + sizeof(struct dm_rq_target_io
);
2756 if (!clone_rq(rq
, md
, tio
, GFP_ATOMIC
))
2757 return BLK_MQ_RQ_QUEUE_BUSY
;
2758 queue_kthread_work(&md
->kworker
, &tio
->work
);
2760 /* Direct call is fine since .queue_rq allows allocations */
2761 if (map_request(tio
, rq
, md
) == DM_MAPIO_REQUEUE
)
2762 dm_requeue_unmapped_original_request(md
, rq
);
2765 return BLK_MQ_RQ_QUEUE_OK
;
2768 static struct blk_mq_ops dm_mq_ops
= {
2769 .queue_rq
= dm_mq_queue_rq
,
2770 .map_queue
= blk_mq_map_queue
,
2771 .complete
= dm_softirq_done
,
2772 .init_request
= dm_mq_init_request
,
2775 static int dm_init_request_based_blk_mq_queue(struct mapped_device
*md
)
2777 unsigned md_type
= dm_get_md_type(md
);
2778 struct request_queue
*q
;
2781 memset(&md
->tag_set
, 0, sizeof(md
->tag_set
));
2782 md
->tag_set
.ops
= &dm_mq_ops
;
2783 md
->tag_set
.queue_depth
= BLKDEV_MAX_RQ
;
2784 md
->tag_set
.numa_node
= NUMA_NO_NODE
;
2785 md
->tag_set
.flags
= BLK_MQ_F_SHOULD_MERGE
| BLK_MQ_F_SG_MERGE
;
2786 md
->tag_set
.nr_hw_queues
= 1;
2787 if (md_type
== DM_TYPE_REQUEST_BASED
) {
2788 /* make the memory for non-blk-mq clone part of the pdu */
2789 md
->tag_set
.cmd_size
= sizeof(struct dm_rq_target_io
) + sizeof(struct request
);
2791 md
->tag_set
.cmd_size
= sizeof(struct dm_rq_target_io
);
2792 md
->tag_set
.driver_data
= md
;
2794 err
= blk_mq_alloc_tag_set(&md
->tag_set
);
2798 q
= blk_mq_init_allocated_queue(&md
->tag_set
, md
->queue
);
2804 dm_init_md_queue(md
);
2806 /* backfill 'mq' sysfs registration normally done in blk_register_queue */
2807 blk_mq_register_disk(md
->disk
);
2809 if (md_type
== DM_TYPE_REQUEST_BASED
)
2810 init_rq_based_worker_thread(md
);
2815 blk_mq_free_tag_set(&md
->tag_set
);
2819 static unsigned filter_md_type(unsigned type
, struct mapped_device
*md
)
2821 if (type
== DM_TYPE_BIO_BASED
)
2824 return !md
->use_blk_mq
? DM_TYPE_REQUEST_BASED
: DM_TYPE_MQ_REQUEST_BASED
;
2828 * Setup the DM device's queue based on md's type
2830 int dm_setup_md_queue(struct mapped_device
*md
)
2833 unsigned md_type
= filter_md_type(dm_get_md_type(md
), md
);
2836 case DM_TYPE_REQUEST_BASED
:
2837 r
= dm_init_request_based_queue(md
);
2839 DMWARN("Cannot initialize queue for request-based mapped device");
2843 case DM_TYPE_MQ_REQUEST_BASED
:
2844 r
= dm_init_request_based_blk_mq_queue(md
);
2846 DMWARN("Cannot initialize queue for request-based blk-mq mapped device");
2850 case DM_TYPE_BIO_BASED
:
2851 dm_init_old_md_queue(md
);
2852 blk_queue_make_request(md
->queue
, dm_make_request
);
2853 blk_queue_merge_bvec(md
->queue
, dm_merge_bvec
);
2860 struct mapped_device
*dm_get_md(dev_t dev
)
2862 struct mapped_device
*md
;
2863 unsigned minor
= MINOR(dev
);
2865 if (MAJOR(dev
) != _major
|| minor
>= (1 << MINORBITS
))
2868 spin_lock(&_minor_lock
);
2870 md
= idr_find(&_minor_idr
, minor
);
2872 if ((md
== MINOR_ALLOCED
||
2873 (MINOR(disk_devt(dm_disk(md
))) != minor
) ||
2874 dm_deleting_md(md
) ||
2875 test_bit(DMF_FREEING
, &md
->flags
))) {
2883 spin_unlock(&_minor_lock
);
2887 EXPORT_SYMBOL_GPL(dm_get_md
);
2889 void *dm_get_mdptr(struct mapped_device
*md
)
2891 return md
->interface_ptr
;
2894 void dm_set_mdptr(struct mapped_device
*md
, void *ptr
)
2896 md
->interface_ptr
= ptr
;
2899 void dm_get(struct mapped_device
*md
)
2901 atomic_inc(&md
->holders
);
2902 BUG_ON(test_bit(DMF_FREEING
, &md
->flags
));
2905 int dm_hold(struct mapped_device
*md
)
2907 spin_lock(&_minor_lock
);
2908 if (test_bit(DMF_FREEING
, &md
->flags
)) {
2909 spin_unlock(&_minor_lock
);
2913 spin_unlock(&_minor_lock
);
2916 EXPORT_SYMBOL_GPL(dm_hold
);
2918 const char *dm_device_name(struct mapped_device
*md
)
2922 EXPORT_SYMBOL_GPL(dm_device_name
);
2924 static void __dm_destroy(struct mapped_device
*md
, bool wait
)
2926 struct dm_table
*map
;
2931 map
= dm_get_live_table(md
, &srcu_idx
);
2933 spin_lock(&_minor_lock
);
2934 idr_replace(&_minor_idr
, MINOR_ALLOCED
, MINOR(disk_devt(dm_disk(md
))));
2935 set_bit(DMF_FREEING
, &md
->flags
);
2936 spin_unlock(&_minor_lock
);
2938 if (dm_request_based(md
) && md
->kworker_task
)
2939 flush_kthread_worker(&md
->kworker
);
2942 * Take suspend_lock so that presuspend and postsuspend methods
2943 * do not race with internal suspend.
2945 mutex_lock(&md
->suspend_lock
);
2946 if (!dm_suspended_md(md
)) {
2947 dm_table_presuspend_targets(map
);
2948 dm_table_postsuspend_targets(map
);
2950 mutex_unlock(&md
->suspend_lock
);
2952 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2953 dm_put_live_table(md
, srcu_idx
);
2956 * Rare, but there may be I/O requests still going to complete,
2957 * for example. Wait for all references to disappear.
2958 * No one should increment the reference count of the mapped_device,
2959 * after the mapped_device state becomes DMF_FREEING.
2962 while (atomic_read(&md
->holders
))
2964 else if (atomic_read(&md
->holders
))
2965 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2966 dm_device_name(md
), atomic_read(&md
->holders
));
2969 dm_table_destroy(__unbind(md
));
2973 void dm_destroy(struct mapped_device
*md
)
2975 __dm_destroy(md
, true);
2978 void dm_destroy_immediate(struct mapped_device
*md
)
2980 __dm_destroy(md
, false);
2983 void dm_put(struct mapped_device
*md
)
2985 atomic_dec(&md
->holders
);
2987 EXPORT_SYMBOL_GPL(dm_put
);
2989 static int dm_wait_for_completion(struct mapped_device
*md
, int interruptible
)
2992 DECLARE_WAITQUEUE(wait
, current
);
2994 add_wait_queue(&md
->wait
, &wait
);
2997 set_current_state(interruptible
);
2999 if (!md_in_flight(md
))
3002 if (interruptible
== TASK_INTERRUPTIBLE
&&
3003 signal_pending(current
)) {
3010 set_current_state(TASK_RUNNING
);
3012 remove_wait_queue(&md
->wait
, &wait
);
3018 * Process the deferred bios
3020 static void dm_wq_work(struct work_struct
*work
)
3022 struct mapped_device
*md
= container_of(work
, struct mapped_device
,
3026 struct dm_table
*map
;
3028 map
= dm_get_live_table(md
, &srcu_idx
);
3030 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
3031 spin_lock_irq(&md
->deferred_lock
);
3032 c
= bio_list_pop(&md
->deferred
);
3033 spin_unlock_irq(&md
->deferred_lock
);
3038 if (dm_request_based(md
))
3039 generic_make_request(c
);
3041 __split_and_process_bio(md
, map
, c
);
3044 dm_put_live_table(md
, srcu_idx
);
3047 static void dm_queue_flush(struct mapped_device
*md
)
3049 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
3050 smp_mb__after_atomic();
3051 queue_work(md
->wq
, &md
->work
);
3055 * Swap in a new table, returning the old one for the caller to destroy.
3057 struct dm_table
*dm_swap_table(struct mapped_device
*md
, struct dm_table
*table
)
3059 struct dm_table
*live_map
= NULL
, *map
= ERR_PTR(-EINVAL
);
3060 struct queue_limits limits
;
3063 mutex_lock(&md
->suspend_lock
);
3065 /* device must be suspended */
3066 if (!dm_suspended_md(md
))
3070 * If the new table has no data devices, retain the existing limits.
3071 * This helps multipath with queue_if_no_path if all paths disappear,
3072 * then new I/O is queued based on these limits, and then some paths
3075 if (dm_table_has_no_data_devices(table
)) {
3076 live_map
= dm_get_live_table_fast(md
);
3078 limits
= md
->queue
->limits
;
3079 dm_put_live_table_fast(md
);
3083 r
= dm_calculate_queue_limits(table
, &limits
);
3090 map
= __bind(md
, table
, &limits
);
3093 mutex_unlock(&md
->suspend_lock
);
3098 * Functions to lock and unlock any filesystem running on the
3101 static int lock_fs(struct mapped_device
*md
)
3105 WARN_ON(md
->frozen_sb
);
3107 md
->frozen_sb
= freeze_bdev(md
->bdev
);
3108 if (IS_ERR(md
->frozen_sb
)) {
3109 r
= PTR_ERR(md
->frozen_sb
);
3110 md
->frozen_sb
= NULL
;
3114 set_bit(DMF_FROZEN
, &md
->flags
);
3119 static void unlock_fs(struct mapped_device
*md
)
3121 if (!test_bit(DMF_FROZEN
, &md
->flags
))
3124 thaw_bdev(md
->bdev
, md
->frozen_sb
);
3125 md
->frozen_sb
= NULL
;
3126 clear_bit(DMF_FROZEN
, &md
->flags
);
3130 * If __dm_suspend returns 0, the device is completely quiescent
3131 * now. There is no request-processing activity. All new requests
3132 * are being added to md->deferred list.
3134 * Caller must hold md->suspend_lock
3136 static int __dm_suspend(struct mapped_device
*md
, struct dm_table
*map
,
3137 unsigned suspend_flags
, int interruptible
)
3139 bool do_lockfs
= suspend_flags
& DM_SUSPEND_LOCKFS_FLAG
;
3140 bool noflush
= suspend_flags
& DM_SUSPEND_NOFLUSH_FLAG
;
3144 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
3145 * This flag is cleared before dm_suspend returns.
3148 set_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
3151 * This gets reverted if there's an error later and the targets
3152 * provide the .presuspend_undo hook.
3154 dm_table_presuspend_targets(map
);
3157 * Flush I/O to the device.
3158 * Any I/O submitted after lock_fs() may not be flushed.
3159 * noflush takes precedence over do_lockfs.
3160 * (lock_fs() flushes I/Os and waits for them to complete.)
3162 if (!noflush
&& do_lockfs
) {
3165 dm_table_presuspend_undo_targets(map
);
3171 * Here we must make sure that no processes are submitting requests
3172 * to target drivers i.e. no one may be executing
3173 * __split_and_process_bio. This is called from dm_request and
3176 * To get all processes out of __split_and_process_bio in dm_request,
3177 * we take the write lock. To prevent any process from reentering
3178 * __split_and_process_bio from dm_request and quiesce the thread
3179 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
3180 * flush_workqueue(md->wq).
3182 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
3184 synchronize_srcu(&md
->io_barrier
);
3187 * Stop md->queue before flushing md->wq in case request-based
3188 * dm defers requests to md->wq from md->queue.
3190 if (dm_request_based(md
)) {
3191 stop_queue(md
->queue
);
3192 if (md
->kworker_task
)
3193 flush_kthread_worker(&md
->kworker
);
3196 flush_workqueue(md
->wq
);
3199 * At this point no more requests are entering target request routines.
3200 * We call dm_wait_for_completion to wait for all existing requests
3203 r
= dm_wait_for_completion(md
, interruptible
);
3206 clear_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
3208 synchronize_srcu(&md
->io_barrier
);
3210 /* were we interrupted ? */
3214 if (dm_request_based(md
))
3215 start_queue(md
->queue
);
3218 dm_table_presuspend_undo_targets(map
);
3219 /* pushback list is already flushed, so skip flush */
3226 * We need to be able to change a mapping table under a mounted
3227 * filesystem. For example we might want to move some data in
3228 * the background. Before the table can be swapped with
3229 * dm_bind_table, dm_suspend must be called to flush any in
3230 * flight bios and ensure that any further io gets deferred.
3233 * Suspend mechanism in request-based dm.
3235 * 1. Flush all I/Os by lock_fs() if needed.
3236 * 2. Stop dispatching any I/O by stopping the request_queue.
3237 * 3. Wait for all in-flight I/Os to be completed or requeued.
3239 * To abort suspend, start the request_queue.
3241 int dm_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
3243 struct dm_table
*map
= NULL
;
3247 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
3249 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
));
3265 r
= __dm_suspend(md
, map
, suspend_flags
, TASK_INTERRUPTIBLE
);
3269 set_bit(DMF_SUSPENDED
, &md
->flags
);
3271 dm_table_postsuspend_targets(map
);
3274 mutex_unlock(&md
->suspend_lock
);
3278 static int __dm_resume(struct mapped_device
*md
, struct dm_table
*map
)
3281 int r
= dm_table_resume_targets(map
);
3289 * Flushing deferred I/Os must be done after targets are resumed
3290 * so that mapping of targets can work correctly.
3291 * Request-based dm is queueing the deferred I/Os in its request_queue.
3293 if (dm_request_based(md
))
3294 start_queue(md
->queue
);
3301 int dm_resume(struct mapped_device
*md
)
3304 struct dm_table
*map
= NULL
;
3307 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
3309 if (!dm_suspended_md(md
))
3312 if (dm_suspended_internally_md(md
)) {
3313 /* already internally suspended, wait for internal resume */
3314 mutex_unlock(&md
->suspend_lock
);
3315 r
= wait_on_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
, TASK_INTERRUPTIBLE
);
3321 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
3322 if (!map
|| !dm_table_get_size(map
))
3325 r
= __dm_resume(md
, map
);
3329 clear_bit(DMF_SUSPENDED
, &md
->flags
);
3333 mutex_unlock(&md
->suspend_lock
);
3339 * Internal suspend/resume works like userspace-driven suspend. It waits
3340 * until all bios finish and prevents issuing new bios to the target drivers.
3341 * It may be used only from the kernel.
3344 static void __dm_internal_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
3346 struct dm_table
*map
= NULL
;
3348 if (md
->internal_suspend_count
++)
3349 return; /* nested internal suspend */
3351 if (dm_suspended_md(md
)) {
3352 set_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3353 return; /* nest suspend */
3356 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
3359 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
3360 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
3361 * would require changing .presuspend to return an error -- avoid this
3362 * until there is a need for more elaborate variants of internal suspend.
3364 (void) __dm_suspend(md
, map
, suspend_flags
, TASK_UNINTERRUPTIBLE
);
3366 set_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3368 dm_table_postsuspend_targets(map
);
3371 static void __dm_internal_resume(struct mapped_device
*md
)
3373 BUG_ON(!md
->internal_suspend_count
);
3375 if (--md
->internal_suspend_count
)
3376 return; /* resume from nested internal suspend */
3378 if (dm_suspended_md(md
))
3379 goto done
; /* resume from nested suspend */
3382 * NOTE: existing callers don't need to call dm_table_resume_targets
3383 * (which may fail -- so best to avoid it for now by passing NULL map)
3385 (void) __dm_resume(md
, NULL
);
3388 clear_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3389 smp_mb__after_atomic();
3390 wake_up_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
);
3393 void dm_internal_suspend_noflush(struct mapped_device
*md
)
3395 mutex_lock(&md
->suspend_lock
);
3396 __dm_internal_suspend(md
, DM_SUSPEND_NOFLUSH_FLAG
);
3397 mutex_unlock(&md
->suspend_lock
);
3399 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush
);
3401 void dm_internal_resume(struct mapped_device
*md
)
3403 mutex_lock(&md
->suspend_lock
);
3404 __dm_internal_resume(md
);
3405 mutex_unlock(&md
->suspend_lock
);
3407 EXPORT_SYMBOL_GPL(dm_internal_resume
);
3410 * Fast variants of internal suspend/resume hold md->suspend_lock,
3411 * which prevents interaction with userspace-driven suspend.
3414 void dm_internal_suspend_fast(struct mapped_device
*md
)
3416 mutex_lock(&md
->suspend_lock
);
3417 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
3420 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
3421 synchronize_srcu(&md
->io_barrier
);
3422 flush_workqueue(md
->wq
);
3423 dm_wait_for_completion(md
, TASK_UNINTERRUPTIBLE
);
3425 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast
);
3427 void dm_internal_resume_fast(struct mapped_device
*md
)
3429 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
3435 mutex_unlock(&md
->suspend_lock
);
3437 EXPORT_SYMBOL_GPL(dm_internal_resume_fast
);
3439 /*-----------------------------------------------------------------
3440 * Event notification.
3441 *---------------------------------------------------------------*/
3442 int dm_kobject_uevent(struct mapped_device
*md
, enum kobject_action action
,
3445 char udev_cookie
[DM_COOKIE_LENGTH
];
3446 char *envp
[] = { udev_cookie
, NULL
};
3449 return kobject_uevent(&disk_to_dev(md
->disk
)->kobj
, action
);
3451 snprintf(udev_cookie
, DM_COOKIE_LENGTH
, "%s=%u",
3452 DM_COOKIE_ENV_VAR_NAME
, cookie
);
3453 return kobject_uevent_env(&disk_to_dev(md
->disk
)->kobj
,
3458 uint32_t dm_next_uevent_seq(struct mapped_device
*md
)
3460 return atomic_add_return(1, &md
->uevent_seq
);
3463 uint32_t dm_get_event_nr(struct mapped_device
*md
)
3465 return atomic_read(&md
->event_nr
);
3468 int dm_wait_event(struct mapped_device
*md
, int event_nr
)
3470 return wait_event_interruptible(md
->eventq
,
3471 (event_nr
!= atomic_read(&md
->event_nr
)));
3474 void dm_uevent_add(struct mapped_device
*md
, struct list_head
*elist
)
3476 unsigned long flags
;
3478 spin_lock_irqsave(&md
->uevent_lock
, flags
);
3479 list_add(elist
, &md
->uevent_list
);
3480 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
3484 * The gendisk is only valid as long as you have a reference
3487 struct gendisk
*dm_disk(struct mapped_device
*md
)
3491 EXPORT_SYMBOL_GPL(dm_disk
);
3493 struct kobject
*dm_kobject(struct mapped_device
*md
)
3495 return &md
->kobj_holder
.kobj
;
3498 struct mapped_device
*dm_get_from_kobject(struct kobject
*kobj
)
3500 struct mapped_device
*md
;
3502 md
= container_of(kobj
, struct mapped_device
, kobj_holder
.kobj
);
3504 if (test_bit(DMF_FREEING
, &md
->flags
) ||
3512 int dm_suspended_md(struct mapped_device
*md
)
3514 return test_bit(DMF_SUSPENDED
, &md
->flags
);
3517 int dm_suspended_internally_md(struct mapped_device
*md
)
3519 return test_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
3522 int dm_test_deferred_remove_flag(struct mapped_device
*md
)
3524 return test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
3527 int dm_suspended(struct dm_target
*ti
)
3529 return dm_suspended_md(dm_table_get_md(ti
->table
));
3531 EXPORT_SYMBOL_GPL(dm_suspended
);
3533 int dm_noflush_suspending(struct dm_target
*ti
)
3535 return __noflush_suspending(dm_table_get_md(ti
->table
));
3537 EXPORT_SYMBOL_GPL(dm_noflush_suspending
);
3539 struct dm_md_mempools
*dm_alloc_md_mempools(struct mapped_device
*md
, unsigned type
,
3540 unsigned integrity
, unsigned per_bio_data_size
)
3542 struct dm_md_mempools
*pools
= kzalloc(sizeof(*pools
), GFP_KERNEL
);
3543 struct kmem_cache
*cachep
= NULL
;
3544 unsigned int pool_size
= 0;
3545 unsigned int front_pad
;
3550 type
= filter_md_type(type
, md
);
3553 case DM_TYPE_BIO_BASED
:
3555 pool_size
= dm_get_reserved_bio_based_ios();
3556 front_pad
= roundup(per_bio_data_size
, __alignof__(struct dm_target_io
)) + offsetof(struct dm_target_io
, clone
);
3558 case DM_TYPE_REQUEST_BASED
:
3559 cachep
= _rq_tio_cache
;
3560 pool_size
= dm_get_reserved_rq_based_ios();
3561 pools
->rq_pool
= mempool_create_slab_pool(pool_size
, _rq_cache
);
3562 if (!pools
->rq_pool
)
3564 /* fall through to setup remaining rq-based pools */
3565 case DM_TYPE_MQ_REQUEST_BASED
:
3567 pool_size
= dm_get_reserved_rq_based_ios();
3568 front_pad
= offsetof(struct dm_rq_clone_bio_info
, clone
);
3569 /* per_bio_data_size is not used. See __bind_mempools(). */
3570 WARN_ON(per_bio_data_size
!= 0);
3577 pools
->io_pool
= mempool_create_slab_pool(pool_size
, cachep
);
3578 if (!pools
->io_pool
)
3582 pools
->bs
= bioset_create_nobvec(pool_size
, front_pad
);
3586 if (integrity
&& bioset_integrity_create(pools
->bs
, pool_size
))
3592 dm_free_md_mempools(pools
);
3597 void dm_free_md_mempools(struct dm_md_mempools
*pools
)
3603 mempool_destroy(pools
->io_pool
);
3606 mempool_destroy(pools
->rq_pool
);
3609 bioset_free(pools
->bs
);
3614 static const struct block_device_operations dm_blk_dops
= {
3615 .open
= dm_blk_open
,
3616 .release
= dm_blk_close
,
3617 .ioctl
= dm_blk_ioctl
,
3618 .getgeo
= dm_blk_getgeo
,
3619 .owner
= THIS_MODULE
3625 module_init(dm_init
);
3626 module_exit(dm_exit
);
3628 module_param(major
, uint
, 0);
3629 MODULE_PARM_DESC(major
, "The major number of the device mapper");
3631 module_param(reserved_bio_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
3632 MODULE_PARM_DESC(reserved_bio_based_ios
, "Reserved IOs in bio-based mempools");
3634 module_param(reserved_rq_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
3635 MODULE_PARM_DESC(reserved_rq_based_ios
, "Reserved IOs in request-based mempools");
3637 module_param(use_blk_mq
, bool, S_IRUGO
| S_IWUSR
);
3638 MODULE_PARM_DESC(use_blk_mq
, "Use block multiqueue for request-based DM devices");
3640 MODULE_DESCRIPTION(DM_NAME
" driver");
3641 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3642 MODULE_LICENSE("GPL");