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.
10 #include "dm-uevent.h"
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/sched/signal.h>
16 #include <linux/blkpg.h>
17 #include <linux/bio.h>
18 #include <linux/mempool.h>
19 #include <linux/dax.h>
20 #include <linux/slab.h>
21 #include <linux/idr.h>
22 #include <linux/hdreg.h>
23 #include <linux/delay.h>
24 #include <linux/wait.h>
27 #define DM_MSG_PREFIX "core"
31 * ratelimit state to be used in DMXXX_LIMIT().
33 DEFINE_RATELIMIT_STATE(dm_ratelimit_state
,
34 DEFAULT_RATELIMIT_INTERVAL
,
35 DEFAULT_RATELIMIT_BURST
);
36 EXPORT_SYMBOL(dm_ratelimit_state
);
40 * Cookies are numeric values sent with CHANGE and REMOVE
41 * uevents while resuming, removing or renaming the device.
43 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
44 #define DM_COOKIE_LENGTH 24
46 static const char *_name
= DM_NAME
;
48 static unsigned int major
= 0;
49 static unsigned int _major
= 0;
51 static DEFINE_IDR(_minor_idr
);
53 static DEFINE_SPINLOCK(_minor_lock
);
55 static void do_deferred_remove(struct work_struct
*w
);
57 static DECLARE_WORK(deferred_remove_work
, do_deferred_remove
);
59 static struct workqueue_struct
*deferred_remove_workqueue
;
62 * One of these is allocated per bio.
65 struct mapped_device
*md
;
69 unsigned long start_time
;
70 spinlock_t endio_lock
;
71 struct dm_stats_aux stats_aux
;
74 #define MINOR_ALLOCED ((void *)-1)
77 * Bits for the md->flags field.
79 #define DMF_BLOCK_IO_FOR_SUSPEND 0
80 #define DMF_SUSPENDED 1
83 #define DMF_DELETING 4
84 #define DMF_NOFLUSH_SUSPENDING 5
85 #define DMF_DEFERRED_REMOVE 6
86 #define DMF_SUSPENDED_INTERNALLY 7
88 #define DM_NUMA_NODE NUMA_NO_NODE
89 static int dm_numa_node
= DM_NUMA_NODE
;
92 * For mempools pre-allocation at the table loading time.
94 struct dm_md_mempools
{
100 struct list_head list
;
102 struct dm_dev dm_dev
;
105 static struct kmem_cache
*_io_cache
;
106 static struct kmem_cache
*_rq_tio_cache
;
107 static struct kmem_cache
*_rq_cache
;
110 * Bio-based DM's mempools' reserved IOs set by the user.
112 #define RESERVED_BIO_BASED_IOS 16
113 static unsigned reserved_bio_based_ios
= RESERVED_BIO_BASED_IOS
;
115 static int __dm_get_module_param_int(int *module_param
, int min
, int max
)
117 int param
= ACCESS_ONCE(*module_param
);
118 int modified_param
= 0;
119 bool modified
= true;
122 modified_param
= min
;
123 else if (param
> max
)
124 modified_param
= max
;
129 (void)cmpxchg(module_param
, param
, modified_param
);
130 param
= modified_param
;
136 unsigned __dm_get_module_param(unsigned *module_param
,
137 unsigned def
, unsigned max
)
139 unsigned param
= ACCESS_ONCE(*module_param
);
140 unsigned modified_param
= 0;
143 modified_param
= def
;
144 else if (param
> max
)
145 modified_param
= max
;
147 if (modified_param
) {
148 (void)cmpxchg(module_param
, param
, modified_param
);
149 param
= modified_param
;
155 unsigned dm_get_reserved_bio_based_ios(void)
157 return __dm_get_module_param(&reserved_bio_based_ios
,
158 RESERVED_BIO_BASED_IOS
, DM_RESERVED_MAX_IOS
);
160 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios
);
162 static unsigned dm_get_numa_node(void)
164 return __dm_get_module_param_int(&dm_numa_node
,
165 DM_NUMA_NODE
, num_online_nodes() - 1);
168 static int __init
local_init(void)
172 /* allocate a slab for the dm_ios */
173 _io_cache
= KMEM_CACHE(dm_io
, 0);
177 _rq_tio_cache
= KMEM_CACHE(dm_rq_target_io
, 0);
179 goto out_free_io_cache
;
181 _rq_cache
= kmem_cache_create("dm_old_clone_request", sizeof(struct request
),
182 __alignof__(struct request
), 0, NULL
);
184 goto out_free_rq_tio_cache
;
186 r
= dm_uevent_init();
188 goto out_free_rq_cache
;
190 deferred_remove_workqueue
= alloc_workqueue("kdmremove", WQ_UNBOUND
, 1);
191 if (!deferred_remove_workqueue
) {
193 goto out_uevent_exit
;
197 r
= register_blkdev(_major
, _name
);
199 goto out_free_workqueue
;
207 destroy_workqueue(deferred_remove_workqueue
);
211 kmem_cache_destroy(_rq_cache
);
212 out_free_rq_tio_cache
:
213 kmem_cache_destroy(_rq_tio_cache
);
215 kmem_cache_destroy(_io_cache
);
220 static void local_exit(void)
222 flush_scheduled_work();
223 destroy_workqueue(deferred_remove_workqueue
);
225 kmem_cache_destroy(_rq_cache
);
226 kmem_cache_destroy(_rq_tio_cache
);
227 kmem_cache_destroy(_io_cache
);
228 unregister_blkdev(_major
, _name
);
233 DMINFO("cleaned up");
236 static int (*_inits
[])(void) __initdata
= {
247 static void (*_exits
[])(void) = {
258 static int __init
dm_init(void)
260 const int count
= ARRAY_SIZE(_inits
);
264 for (i
= 0; i
< count
; i
++) {
279 static void __exit
dm_exit(void)
281 int i
= ARRAY_SIZE(_exits
);
287 * Should be empty by this point.
289 idr_destroy(&_minor_idr
);
293 * Block device functions
295 int dm_deleting_md(struct mapped_device
*md
)
297 return test_bit(DMF_DELETING
, &md
->flags
);
300 static int dm_blk_open(struct block_device
*bdev
, fmode_t mode
)
302 struct mapped_device
*md
;
304 spin_lock(&_minor_lock
);
306 md
= bdev
->bd_disk
->private_data
;
310 if (test_bit(DMF_FREEING
, &md
->flags
) ||
311 dm_deleting_md(md
)) {
317 atomic_inc(&md
->open_count
);
319 spin_unlock(&_minor_lock
);
321 return md
? 0 : -ENXIO
;
324 static void dm_blk_close(struct gendisk
*disk
, fmode_t mode
)
326 struct mapped_device
*md
;
328 spin_lock(&_minor_lock
);
330 md
= disk
->private_data
;
334 if (atomic_dec_and_test(&md
->open_count
) &&
335 (test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
)))
336 queue_work(deferred_remove_workqueue
, &deferred_remove_work
);
340 spin_unlock(&_minor_lock
);
343 int dm_open_count(struct mapped_device
*md
)
345 return atomic_read(&md
->open_count
);
349 * Guarantees nothing is using the device before it's deleted.
351 int dm_lock_for_deletion(struct mapped_device
*md
, bool mark_deferred
, bool only_deferred
)
355 spin_lock(&_minor_lock
);
357 if (dm_open_count(md
)) {
360 set_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
361 } else if (only_deferred
&& !test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
))
364 set_bit(DMF_DELETING
, &md
->flags
);
366 spin_unlock(&_minor_lock
);
371 int dm_cancel_deferred_remove(struct mapped_device
*md
)
375 spin_lock(&_minor_lock
);
377 if (test_bit(DMF_DELETING
, &md
->flags
))
380 clear_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
382 spin_unlock(&_minor_lock
);
387 static void do_deferred_remove(struct work_struct
*w
)
389 dm_deferred_remove();
392 sector_t
dm_get_size(struct mapped_device
*md
)
394 return get_capacity(md
->disk
);
397 struct request_queue
*dm_get_md_queue(struct mapped_device
*md
)
402 struct dm_stats
*dm_get_stats(struct mapped_device
*md
)
407 static int dm_blk_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
409 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
411 return dm_get_geometry(md
, geo
);
414 static int dm_grab_bdev_for_ioctl(struct mapped_device
*md
,
415 struct block_device
**bdev
,
418 struct dm_target
*tgt
;
419 struct dm_table
*map
;
424 map
= dm_get_live_table(md
, &srcu_idx
);
425 if (!map
|| !dm_table_get_size(map
))
428 /* We only support devices that have a single target */
429 if (dm_table_get_num_targets(map
) != 1)
432 tgt
= dm_table_get_target(map
, 0);
433 if (!tgt
->type
->prepare_ioctl
)
436 if (dm_suspended_md(md
)) {
441 r
= tgt
->type
->prepare_ioctl(tgt
, bdev
, mode
);
446 dm_put_live_table(md
, srcu_idx
);
450 dm_put_live_table(md
, srcu_idx
);
451 if (r
== -ENOTCONN
&& !fatal_signal_pending(current
)) {
458 static int dm_blk_ioctl(struct block_device
*bdev
, fmode_t mode
,
459 unsigned int cmd
, unsigned long arg
)
461 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
464 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
470 * Target determined this ioctl is being issued against a
471 * subset of the parent bdev; require extra privileges.
473 if (!capable(CAP_SYS_RAWIO
)) {
475 "%s: sending ioctl %x to DM device without required privilege.",
482 r
= __blkdev_driver_ioctl(bdev
, mode
, cmd
, arg
);
488 static struct dm_io
*alloc_io(struct mapped_device
*md
)
490 return mempool_alloc(md
->io_pool
, GFP_NOIO
);
493 static void free_io(struct mapped_device
*md
, struct dm_io
*io
)
495 mempool_free(io
, md
->io_pool
);
498 static void free_tio(struct dm_target_io
*tio
)
500 bio_put(&tio
->clone
);
503 int md_in_flight(struct mapped_device
*md
)
505 return atomic_read(&md
->pending
[READ
]) +
506 atomic_read(&md
->pending
[WRITE
]);
509 static void start_io_acct(struct dm_io
*io
)
511 struct mapped_device
*md
= io
->md
;
512 struct bio
*bio
= io
->bio
;
514 int rw
= bio_data_dir(bio
);
516 io
->start_time
= jiffies
;
518 cpu
= part_stat_lock();
519 part_round_stats(cpu
, &dm_disk(md
)->part0
);
521 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
],
522 atomic_inc_return(&md
->pending
[rw
]));
524 if (unlikely(dm_stats_used(&md
->stats
)))
525 dm_stats_account_io(&md
->stats
, bio_data_dir(bio
),
526 bio
->bi_iter
.bi_sector
, bio_sectors(bio
),
527 false, 0, &io
->stats_aux
);
530 static void end_io_acct(struct dm_io
*io
)
532 struct mapped_device
*md
= io
->md
;
533 struct bio
*bio
= io
->bio
;
534 unsigned long duration
= jiffies
- io
->start_time
;
536 int rw
= bio_data_dir(bio
);
538 generic_end_io_acct(rw
, &dm_disk(md
)->part0
, io
->start_time
);
540 if (unlikely(dm_stats_used(&md
->stats
)))
541 dm_stats_account_io(&md
->stats
, bio_data_dir(bio
),
542 bio
->bi_iter
.bi_sector
, bio_sectors(bio
),
543 true, duration
, &io
->stats_aux
);
546 * After this is decremented the bio must not be touched if it is
549 pending
= atomic_dec_return(&md
->pending
[rw
]);
550 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
], pending
);
551 pending
+= atomic_read(&md
->pending
[rw
^0x1]);
553 /* nudge anyone waiting on suspend queue */
559 * Add the bio to the list of deferred io.
561 static void queue_io(struct mapped_device
*md
, struct bio
*bio
)
565 spin_lock_irqsave(&md
->deferred_lock
, flags
);
566 bio_list_add(&md
->deferred
, bio
);
567 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
568 queue_work(md
->wq
, &md
->work
);
572 * Everyone (including functions in this file), should use this
573 * function to access the md->map field, and make sure they call
574 * dm_put_live_table() when finished.
576 struct dm_table
*dm_get_live_table(struct mapped_device
*md
, int *srcu_idx
) __acquires(md
->io_barrier
)
578 *srcu_idx
= srcu_read_lock(&md
->io_barrier
);
580 return srcu_dereference(md
->map
, &md
->io_barrier
);
583 void dm_put_live_table(struct mapped_device
*md
, int srcu_idx
) __releases(md
->io_barrier
)
585 srcu_read_unlock(&md
->io_barrier
, srcu_idx
);
588 void dm_sync_table(struct mapped_device
*md
)
590 synchronize_srcu(&md
->io_barrier
);
591 synchronize_rcu_expedited();
595 * A fast alternative to dm_get_live_table/dm_put_live_table.
596 * The caller must not block between these two functions.
598 static struct dm_table
*dm_get_live_table_fast(struct mapped_device
*md
) __acquires(RCU
)
601 return rcu_dereference(md
->map
);
604 static void dm_put_live_table_fast(struct mapped_device
*md
) __releases(RCU
)
610 * Open a table device so we can use it as a map destination.
612 static int open_table_device(struct table_device
*td
, dev_t dev
,
613 struct mapped_device
*md
)
615 static char *_claim_ptr
= "I belong to device-mapper";
616 struct block_device
*bdev
;
620 BUG_ON(td
->dm_dev
.bdev
);
622 bdev
= blkdev_get_by_dev(dev
, td
->dm_dev
.mode
| FMODE_EXCL
, _claim_ptr
);
624 return PTR_ERR(bdev
);
626 r
= bd_link_disk_holder(bdev
, dm_disk(md
));
628 blkdev_put(bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
632 td
->dm_dev
.bdev
= bdev
;
633 td
->dm_dev
.dax_dev
= dax_get_by_host(bdev
->bd_disk
->disk_name
);
638 * Close a table device that we've been using.
640 static void close_table_device(struct table_device
*td
, struct mapped_device
*md
)
642 if (!td
->dm_dev
.bdev
)
645 bd_unlink_disk_holder(td
->dm_dev
.bdev
, dm_disk(md
));
646 blkdev_put(td
->dm_dev
.bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
647 put_dax(td
->dm_dev
.dax_dev
);
648 td
->dm_dev
.bdev
= NULL
;
649 td
->dm_dev
.dax_dev
= NULL
;
652 static struct table_device
*find_table_device(struct list_head
*l
, dev_t dev
,
654 struct table_device
*td
;
656 list_for_each_entry(td
, l
, list
)
657 if (td
->dm_dev
.bdev
->bd_dev
== dev
&& td
->dm_dev
.mode
== mode
)
663 int dm_get_table_device(struct mapped_device
*md
, dev_t dev
, fmode_t mode
,
664 struct dm_dev
**result
) {
666 struct table_device
*td
;
668 mutex_lock(&md
->table_devices_lock
);
669 td
= find_table_device(&md
->table_devices
, dev
, mode
);
671 td
= kmalloc_node(sizeof(*td
), GFP_KERNEL
, md
->numa_node_id
);
673 mutex_unlock(&md
->table_devices_lock
);
677 td
->dm_dev
.mode
= mode
;
678 td
->dm_dev
.bdev
= NULL
;
680 if ((r
= open_table_device(td
, dev
, md
))) {
681 mutex_unlock(&md
->table_devices_lock
);
686 format_dev_t(td
->dm_dev
.name
, dev
);
688 atomic_set(&td
->count
, 0);
689 list_add(&td
->list
, &md
->table_devices
);
691 atomic_inc(&td
->count
);
692 mutex_unlock(&md
->table_devices_lock
);
694 *result
= &td
->dm_dev
;
697 EXPORT_SYMBOL_GPL(dm_get_table_device
);
699 void dm_put_table_device(struct mapped_device
*md
, struct dm_dev
*d
)
701 struct table_device
*td
= container_of(d
, struct table_device
, dm_dev
);
703 mutex_lock(&md
->table_devices_lock
);
704 if (atomic_dec_and_test(&td
->count
)) {
705 close_table_device(td
, md
);
709 mutex_unlock(&md
->table_devices_lock
);
711 EXPORT_SYMBOL(dm_put_table_device
);
713 static void free_table_devices(struct list_head
*devices
)
715 struct list_head
*tmp
, *next
;
717 list_for_each_safe(tmp
, next
, devices
) {
718 struct table_device
*td
= list_entry(tmp
, struct table_device
, list
);
720 DMWARN("dm_destroy: %s still exists with %d references",
721 td
->dm_dev
.name
, atomic_read(&td
->count
));
727 * Get the geometry associated with a dm device
729 int dm_get_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
737 * Set the geometry of a device.
739 int dm_set_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
741 sector_t sz
= (sector_t
)geo
->cylinders
* geo
->heads
* geo
->sectors
;
743 if (geo
->start
> sz
) {
744 DMWARN("Start sector is beyond the geometry limits.");
753 /*-----------------------------------------------------------------
755 * A more elegant soln is in the works that uses the queue
756 * merge fn, unfortunately there are a couple of changes to
757 * the block layer that I want to make for this. So in the
758 * interests of getting something for people to use I give
759 * you this clearly demarcated crap.
760 *---------------------------------------------------------------*/
762 static int __noflush_suspending(struct mapped_device
*md
)
764 return test_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
768 * Decrements the number of outstanding ios that a bio has been
769 * cloned into, completing the original io if necc.
771 static void dec_pending(struct dm_io
*io
, int error
)
776 struct mapped_device
*md
= io
->md
;
778 /* Push-back supersedes any I/O errors */
779 if (unlikely(error
)) {
780 spin_lock_irqsave(&io
->endio_lock
, flags
);
781 if (!(io
->error
> 0 && __noflush_suspending(md
)))
783 spin_unlock_irqrestore(&io
->endio_lock
, flags
);
786 if (atomic_dec_and_test(&io
->io_count
)) {
787 if (io
->error
== DM_ENDIO_REQUEUE
) {
789 * Target requested pushing back the I/O.
791 spin_lock_irqsave(&md
->deferred_lock
, flags
);
792 if (__noflush_suspending(md
))
793 bio_list_add_head(&md
->deferred
, io
->bio
);
795 /* noflush suspend was interrupted. */
797 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
800 io_error
= io
->error
;
805 if (io_error
== DM_ENDIO_REQUEUE
)
808 if ((bio
->bi_opf
& REQ_PREFLUSH
) && bio
->bi_iter
.bi_size
) {
810 * Preflush done for flush with data, reissue
811 * without REQ_PREFLUSH.
813 bio
->bi_opf
&= ~REQ_PREFLUSH
;
816 /* done with normal IO or empty flush */
817 bio
->bi_error
= io_error
;
823 void disable_write_same(struct mapped_device
*md
)
825 struct queue_limits
*limits
= dm_get_queue_limits(md
);
827 /* device doesn't really support WRITE SAME, disable it */
828 limits
->max_write_same_sectors
= 0;
831 void disable_write_zeroes(struct mapped_device
*md
)
833 struct queue_limits
*limits
= dm_get_queue_limits(md
);
835 /* device doesn't really support WRITE ZEROES, disable it */
836 limits
->max_write_zeroes_sectors
= 0;
839 static void clone_endio(struct bio
*bio
)
841 int error
= bio
->bi_error
;
843 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
844 struct dm_io
*io
= tio
->io
;
845 struct mapped_device
*md
= tio
->io
->md
;
846 dm_endio_fn endio
= tio
->ti
->type
->end_io
;
849 r
= endio(tio
->ti
, bio
, error
);
850 if (r
< 0 || r
== DM_ENDIO_REQUEUE
)
852 * error and requeue request are handled
856 else if (r
== DM_ENDIO_INCOMPLETE
)
857 /* The target will handle the io */
860 DMWARN("unimplemented target endio return value: %d", r
);
865 if (unlikely(r
== -EREMOTEIO
)) {
866 if (bio_op(bio
) == REQ_OP_WRITE_SAME
&&
867 !bdev_get_queue(bio
->bi_bdev
)->limits
.max_write_same_sectors
)
868 disable_write_same(md
);
869 if (bio_op(bio
) == REQ_OP_WRITE_ZEROES
&&
870 !bdev_get_queue(bio
->bi_bdev
)->limits
.max_write_zeroes_sectors
)
871 disable_write_zeroes(md
);
875 dec_pending(io
, error
);
879 * Return maximum size of I/O possible at the supplied sector up to the current
882 static sector_t
max_io_len_target_boundary(sector_t sector
, struct dm_target
*ti
)
884 sector_t target_offset
= dm_target_offset(ti
, sector
);
886 return ti
->len
- target_offset
;
889 static sector_t
max_io_len(sector_t sector
, struct dm_target
*ti
)
891 sector_t len
= max_io_len_target_boundary(sector
, ti
);
892 sector_t offset
, max_len
;
895 * Does the target need to split even further?
897 if (ti
->max_io_len
) {
898 offset
= dm_target_offset(ti
, sector
);
899 if (unlikely(ti
->max_io_len
& (ti
->max_io_len
- 1)))
900 max_len
= sector_div(offset
, ti
->max_io_len
);
902 max_len
= offset
& (ti
->max_io_len
- 1);
903 max_len
= ti
->max_io_len
- max_len
;
912 int dm_set_target_max_io_len(struct dm_target
*ti
, sector_t len
)
914 if (len
> UINT_MAX
) {
915 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
916 (unsigned long long)len
, UINT_MAX
);
917 ti
->error
= "Maximum size of target IO is too large";
921 ti
->max_io_len
= (uint32_t) len
;
925 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len
);
927 static struct dm_target
*dm_dax_get_live_target(struct mapped_device
*md
,
928 sector_t sector
, int *srcu_idx
)
930 struct dm_table
*map
;
931 struct dm_target
*ti
;
933 map
= dm_get_live_table(md
, srcu_idx
);
937 ti
= dm_table_find_target(map
, sector
);
938 if (!dm_target_is_valid(ti
))
944 static long dm_dax_direct_access(struct dax_device
*dax_dev
, pgoff_t pgoff
,
945 long nr_pages
, void **kaddr
, pfn_t
*pfn
)
947 struct mapped_device
*md
= dax_get_private(dax_dev
);
948 sector_t sector
= pgoff
* PAGE_SECTORS
;
949 struct dm_target
*ti
;
950 long len
, ret
= -EIO
;
953 ti
= dm_dax_get_live_target(md
, sector
, &srcu_idx
);
957 if (!ti
->type
->direct_access
)
959 len
= max_io_len(sector
, ti
) / PAGE_SECTORS
;
962 nr_pages
= min(len
, nr_pages
);
963 if (ti
->type
->direct_access
)
964 ret
= ti
->type
->direct_access(ti
, pgoff
, nr_pages
, kaddr
, pfn
);
967 dm_put_live_table(md
, srcu_idx
);
973 * A target may call dm_accept_partial_bio only from the map routine. It is
974 * allowed for all bio types except REQ_PREFLUSH.
976 * dm_accept_partial_bio informs the dm that the target only wants to process
977 * additional n_sectors sectors of the bio and the rest of the data should be
978 * sent in a next bio.
980 * A diagram that explains the arithmetics:
981 * +--------------------+---------------+-------+
983 * +--------------------+---------------+-------+
985 * <-------------- *tio->len_ptr --------------->
986 * <------- bi_size ------->
989 * Region 1 was already iterated over with bio_advance or similar function.
990 * (it may be empty if the target doesn't use bio_advance)
991 * Region 2 is the remaining bio size that the target wants to process.
992 * (it may be empty if region 1 is non-empty, although there is no reason
994 * The target requires that region 3 is to be sent in the next bio.
996 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
997 * the partially processed part (the sum of regions 1+2) must be the same for all
1000 void dm_accept_partial_bio(struct bio
*bio
, unsigned n_sectors
)
1002 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
1003 unsigned bi_size
= bio
->bi_iter
.bi_size
>> SECTOR_SHIFT
;
1004 BUG_ON(bio
->bi_opf
& REQ_PREFLUSH
);
1005 BUG_ON(bi_size
> *tio
->len_ptr
);
1006 BUG_ON(n_sectors
> bi_size
);
1007 *tio
->len_ptr
-= bi_size
- n_sectors
;
1008 bio
->bi_iter
.bi_size
= n_sectors
<< SECTOR_SHIFT
;
1010 EXPORT_SYMBOL_GPL(dm_accept_partial_bio
);
1013 * Flush current->bio_list when the target map method blocks.
1014 * This fixes deadlocks in snapshot and possibly in other targets.
1017 struct blk_plug plug
;
1018 struct blk_plug_cb cb
;
1021 static void flush_current_bio_list(struct blk_plug_cb
*cb
, bool from_schedule
)
1023 struct dm_offload
*o
= container_of(cb
, struct dm_offload
, cb
);
1024 struct bio_list list
;
1028 INIT_LIST_HEAD(&o
->cb
.list
);
1030 if (unlikely(!current
->bio_list
))
1033 for (i
= 0; i
< 2; i
++) {
1034 list
= current
->bio_list
[i
];
1035 bio_list_init(¤t
->bio_list
[i
]);
1037 while ((bio
= bio_list_pop(&list
))) {
1038 struct bio_set
*bs
= bio
->bi_pool
;
1039 if (unlikely(!bs
) || bs
== fs_bio_set
) {
1040 bio_list_add(¤t
->bio_list
[i
], bio
);
1044 spin_lock(&bs
->rescue_lock
);
1045 bio_list_add(&bs
->rescue_list
, bio
);
1046 queue_work(bs
->rescue_workqueue
, &bs
->rescue_work
);
1047 spin_unlock(&bs
->rescue_lock
);
1052 static void dm_offload_start(struct dm_offload
*o
)
1054 blk_start_plug(&o
->plug
);
1055 o
->cb
.callback
= flush_current_bio_list
;
1056 list_add(&o
->cb
.list
, ¤t
->plug
->cb_list
);
1059 static void dm_offload_end(struct dm_offload
*o
)
1061 list_del(&o
->cb
.list
);
1062 blk_finish_plug(&o
->plug
);
1065 static void __map_bio(struct dm_target_io
*tio
)
1069 struct dm_offload o
;
1070 struct bio
*clone
= &tio
->clone
;
1071 struct dm_target
*ti
= tio
->ti
;
1073 clone
->bi_end_io
= clone_endio
;
1076 * Map the clone. If r == 0 we don't need to do
1077 * anything, the target has assumed ownership of
1080 atomic_inc(&tio
->io
->io_count
);
1081 sector
= clone
->bi_iter
.bi_sector
;
1083 dm_offload_start(&o
);
1084 r
= ti
->type
->map(ti
, clone
);
1087 if (r
== DM_MAPIO_REMAPPED
) {
1088 /* the bio has been remapped so dispatch it */
1090 trace_block_bio_remap(bdev_get_queue(clone
->bi_bdev
), clone
,
1091 tio
->io
->bio
->bi_bdev
->bd_dev
, sector
);
1093 generic_make_request(clone
);
1094 } else if (r
< 0 || r
== DM_MAPIO_REQUEUE
) {
1095 /* error the io and bail out, or requeue it if needed */
1096 dec_pending(tio
->io
, r
);
1098 } else if (r
!= DM_MAPIO_SUBMITTED
) {
1099 DMWARN("unimplemented target map return value: %d", r
);
1105 struct mapped_device
*md
;
1106 struct dm_table
*map
;
1110 unsigned sector_count
;
1113 static void bio_setup_sector(struct bio
*bio
, sector_t sector
, unsigned len
)
1115 bio
->bi_iter
.bi_sector
= sector
;
1116 bio
->bi_iter
.bi_size
= to_bytes(len
);
1120 * Creates a bio that consists of range of complete bvecs.
1122 static int clone_bio(struct dm_target_io
*tio
, struct bio
*bio
,
1123 sector_t sector
, unsigned len
)
1125 struct bio
*clone
= &tio
->clone
;
1127 __bio_clone_fast(clone
, bio
);
1129 if (unlikely(bio_integrity(bio
) != NULL
)) {
1132 if (unlikely(!dm_target_has_integrity(tio
->ti
->type
) &&
1133 !dm_target_passes_integrity(tio
->ti
->type
))) {
1134 DMWARN("%s: the target %s doesn't support integrity data.",
1135 dm_device_name(tio
->io
->md
),
1136 tio
->ti
->type
->name
);
1140 r
= bio_integrity_clone(clone
, bio
, GFP_NOIO
);
1145 bio_advance(clone
, to_bytes(sector
- clone
->bi_iter
.bi_sector
));
1146 clone
->bi_iter
.bi_size
= to_bytes(len
);
1148 if (unlikely(bio_integrity(bio
) != NULL
))
1149 bio_integrity_trim(clone
, 0, len
);
1154 static struct dm_target_io
*alloc_tio(struct clone_info
*ci
,
1155 struct dm_target
*ti
,
1156 unsigned target_bio_nr
)
1158 struct dm_target_io
*tio
;
1161 clone
= bio_alloc_bioset(GFP_NOIO
, 0, ci
->md
->bs
);
1162 tio
= container_of(clone
, struct dm_target_io
, clone
);
1166 tio
->target_bio_nr
= target_bio_nr
;
1171 static void __clone_and_map_simple_bio(struct clone_info
*ci
,
1172 struct dm_target
*ti
,
1173 unsigned target_bio_nr
, unsigned *len
)
1175 struct dm_target_io
*tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1176 struct bio
*clone
= &tio
->clone
;
1180 __bio_clone_fast(clone
, ci
->bio
);
1182 bio_setup_sector(clone
, ci
->sector
, *len
);
1187 static void __send_duplicate_bios(struct clone_info
*ci
, struct dm_target
*ti
,
1188 unsigned num_bios
, unsigned *len
)
1190 unsigned target_bio_nr
;
1192 for (target_bio_nr
= 0; target_bio_nr
< num_bios
; target_bio_nr
++)
1193 __clone_and_map_simple_bio(ci
, ti
, target_bio_nr
, len
);
1196 static int __send_empty_flush(struct clone_info
*ci
)
1198 unsigned target_nr
= 0;
1199 struct dm_target
*ti
;
1201 BUG_ON(bio_has_data(ci
->bio
));
1202 while ((ti
= dm_table_get_target(ci
->map
, target_nr
++)))
1203 __send_duplicate_bios(ci
, ti
, ti
->num_flush_bios
, NULL
);
1208 static int __clone_and_map_data_bio(struct clone_info
*ci
, struct dm_target
*ti
,
1209 sector_t sector
, unsigned *len
)
1211 struct bio
*bio
= ci
->bio
;
1212 struct dm_target_io
*tio
;
1213 unsigned target_bio_nr
;
1214 unsigned num_target_bios
= 1;
1218 * Does the target want to receive duplicate copies of the bio?
1220 if (bio_data_dir(bio
) == WRITE
&& ti
->num_write_bios
)
1221 num_target_bios
= ti
->num_write_bios(ti
, bio
);
1223 for (target_bio_nr
= 0; target_bio_nr
< num_target_bios
; target_bio_nr
++) {
1224 tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1226 r
= clone_bio(tio
, bio
, sector
, *len
);
1237 typedef unsigned (*get_num_bios_fn
)(struct dm_target
*ti
);
1239 static unsigned get_num_discard_bios(struct dm_target
*ti
)
1241 return ti
->num_discard_bios
;
1244 static unsigned get_num_write_same_bios(struct dm_target
*ti
)
1246 return ti
->num_write_same_bios
;
1249 static unsigned get_num_write_zeroes_bios(struct dm_target
*ti
)
1251 return ti
->num_write_zeroes_bios
;
1254 typedef bool (*is_split_required_fn
)(struct dm_target
*ti
);
1256 static bool is_split_required_for_discard(struct dm_target
*ti
)
1258 return ti
->split_discard_bios
;
1261 static int __send_changing_extent_only(struct clone_info
*ci
,
1262 get_num_bios_fn get_num_bios
,
1263 is_split_required_fn is_split_required
)
1265 struct dm_target
*ti
;
1270 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1271 if (!dm_target_is_valid(ti
))
1275 * Even though the device advertised support for this type of
1276 * request, that does not mean every target supports it, and
1277 * reconfiguration might also have changed that since the
1278 * check was performed.
1280 num_bios
= get_num_bios
? get_num_bios(ti
) : 0;
1284 if (is_split_required
&& !is_split_required(ti
))
1285 len
= min((sector_t
)ci
->sector_count
, max_io_len_target_boundary(ci
->sector
, ti
));
1287 len
= min((sector_t
)ci
->sector_count
, max_io_len(ci
->sector
, ti
));
1289 __send_duplicate_bios(ci
, ti
, num_bios
, &len
);
1292 } while (ci
->sector_count
-= len
);
1297 static int __send_discard(struct clone_info
*ci
)
1299 return __send_changing_extent_only(ci
, get_num_discard_bios
,
1300 is_split_required_for_discard
);
1303 static int __send_write_same(struct clone_info
*ci
)
1305 return __send_changing_extent_only(ci
, get_num_write_same_bios
, NULL
);
1308 static int __send_write_zeroes(struct clone_info
*ci
)
1310 return __send_changing_extent_only(ci
, get_num_write_zeroes_bios
, NULL
);
1314 * Select the correct strategy for processing a non-flush bio.
1316 static int __split_and_process_non_flush(struct clone_info
*ci
)
1318 struct bio
*bio
= ci
->bio
;
1319 struct dm_target
*ti
;
1323 if (unlikely(bio_op(bio
) == REQ_OP_DISCARD
))
1324 return __send_discard(ci
);
1325 else if (unlikely(bio_op(bio
) == REQ_OP_WRITE_SAME
))
1326 return __send_write_same(ci
);
1327 else if (unlikely(bio_op(bio
) == REQ_OP_WRITE_ZEROES
))
1328 return __send_write_zeroes(ci
);
1330 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1331 if (!dm_target_is_valid(ti
))
1334 len
= min_t(sector_t
, max_io_len(ci
->sector
, ti
), ci
->sector_count
);
1336 r
= __clone_and_map_data_bio(ci
, ti
, ci
->sector
, &len
);
1341 ci
->sector_count
-= len
;
1347 * Entry point to split a bio into clones and submit them to the targets.
1349 static void __split_and_process_bio(struct mapped_device
*md
,
1350 struct dm_table
*map
, struct bio
*bio
)
1352 struct clone_info ci
;
1355 if (unlikely(!map
)) {
1362 ci
.io
= alloc_io(md
);
1364 atomic_set(&ci
.io
->io_count
, 1);
1367 spin_lock_init(&ci
.io
->endio_lock
);
1368 ci
.sector
= bio
->bi_iter
.bi_sector
;
1370 start_io_acct(ci
.io
);
1372 if (bio
->bi_opf
& REQ_PREFLUSH
) {
1373 ci
.bio
= &ci
.md
->flush_bio
;
1374 ci
.sector_count
= 0;
1375 error
= __send_empty_flush(&ci
);
1376 /* dec_pending submits any data associated with flush */
1379 ci
.sector_count
= bio_sectors(bio
);
1380 while (ci
.sector_count
&& !error
)
1381 error
= __split_and_process_non_flush(&ci
);
1384 /* drop the extra reference count */
1385 dec_pending(ci
.io
, error
);
1387 /*-----------------------------------------------------------------
1389 *---------------------------------------------------------------*/
1392 * The request function that just remaps the bio built up by
1395 static blk_qc_t
dm_make_request(struct request_queue
*q
, struct bio
*bio
)
1397 int rw
= bio_data_dir(bio
);
1398 struct mapped_device
*md
= q
->queuedata
;
1400 struct dm_table
*map
;
1402 map
= dm_get_live_table(md
, &srcu_idx
);
1404 generic_start_io_acct(rw
, bio_sectors(bio
), &dm_disk(md
)->part0
);
1406 /* if we're suspended, we have to queue this io for later */
1407 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))) {
1408 dm_put_live_table(md
, srcu_idx
);
1410 if (!(bio
->bi_opf
& REQ_RAHEAD
))
1414 return BLK_QC_T_NONE
;
1417 __split_and_process_bio(md
, map
, bio
);
1418 dm_put_live_table(md
, srcu_idx
);
1419 return BLK_QC_T_NONE
;
1422 static int dm_any_congested(void *congested_data
, int bdi_bits
)
1425 struct mapped_device
*md
= congested_data
;
1426 struct dm_table
*map
;
1428 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
1429 if (dm_request_based(md
)) {
1431 * With request-based DM we only need to check the
1432 * top-level queue for congestion.
1434 r
= md
->queue
->backing_dev_info
->wb
.state
& bdi_bits
;
1436 map
= dm_get_live_table_fast(md
);
1438 r
= dm_table_any_congested(map
, bdi_bits
);
1439 dm_put_live_table_fast(md
);
1446 /*-----------------------------------------------------------------
1447 * An IDR is used to keep track of allocated minor numbers.
1448 *---------------------------------------------------------------*/
1449 static void free_minor(int minor
)
1451 spin_lock(&_minor_lock
);
1452 idr_remove(&_minor_idr
, minor
);
1453 spin_unlock(&_minor_lock
);
1457 * See if the device with a specific minor # is free.
1459 static int specific_minor(int minor
)
1463 if (minor
>= (1 << MINORBITS
))
1466 idr_preload(GFP_KERNEL
);
1467 spin_lock(&_minor_lock
);
1469 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, minor
, minor
+ 1, GFP_NOWAIT
);
1471 spin_unlock(&_minor_lock
);
1474 return r
== -ENOSPC
? -EBUSY
: r
;
1478 static int next_free_minor(int *minor
)
1482 idr_preload(GFP_KERNEL
);
1483 spin_lock(&_minor_lock
);
1485 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, 0, 1 << MINORBITS
, GFP_NOWAIT
);
1487 spin_unlock(&_minor_lock
);
1495 static const struct block_device_operations dm_blk_dops
;
1496 static const struct dax_operations dm_dax_ops
;
1498 static void dm_wq_work(struct work_struct
*work
);
1500 void dm_init_md_queue(struct mapped_device
*md
)
1503 * Request-based dm devices cannot be stacked on top of bio-based dm
1504 * devices. The type of this dm device may not have been decided yet.
1505 * The type is decided at the first table loading time.
1506 * To prevent problematic device stacking, clear the queue flag
1507 * for request stacking support until then.
1509 * This queue is new, so no concurrency on the queue_flags.
1511 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE
, md
->queue
);
1514 * Initialize data that will only be used by a non-blk-mq DM queue
1515 * - must do so here (in alloc_dev callchain) before queue is used
1517 md
->queue
->queuedata
= md
;
1518 md
->queue
->backing_dev_info
->congested_data
= md
;
1521 void dm_init_normal_md_queue(struct mapped_device
*md
)
1523 md
->use_blk_mq
= false;
1524 dm_init_md_queue(md
);
1527 * Initialize aspects of queue that aren't relevant for blk-mq
1529 md
->queue
->backing_dev_info
->congested_fn
= dm_any_congested
;
1530 blk_queue_bounce_limit(md
->queue
, BLK_BOUNCE_ANY
);
1533 static void cleanup_mapped_device(struct mapped_device
*md
)
1536 destroy_workqueue(md
->wq
);
1537 if (md
->kworker_task
)
1538 kthread_stop(md
->kworker_task
);
1539 mempool_destroy(md
->io_pool
);
1541 bioset_free(md
->bs
);
1544 kill_dax(md
->dax_dev
);
1545 put_dax(md
->dax_dev
);
1550 spin_lock(&_minor_lock
);
1551 md
->disk
->private_data
= NULL
;
1552 spin_unlock(&_minor_lock
);
1553 del_gendisk(md
->disk
);
1558 blk_cleanup_queue(md
->queue
);
1560 cleanup_srcu_struct(&md
->io_barrier
);
1567 dm_mq_cleanup_mapped_device(md
);
1571 * Allocate and initialise a blank device with a given minor.
1573 static struct mapped_device
*alloc_dev(int minor
)
1575 int r
, numa_node_id
= dm_get_numa_node();
1576 struct dax_device
*dax_dev
;
1577 struct mapped_device
*md
;
1580 md
= kzalloc_node(sizeof(*md
), GFP_KERNEL
, numa_node_id
);
1582 DMWARN("unable to allocate device, out of memory.");
1586 if (!try_module_get(THIS_MODULE
))
1587 goto bad_module_get
;
1589 /* get a minor number for the dev */
1590 if (minor
== DM_ANY_MINOR
)
1591 r
= next_free_minor(&minor
);
1593 r
= specific_minor(minor
);
1597 r
= init_srcu_struct(&md
->io_barrier
);
1599 goto bad_io_barrier
;
1601 md
->numa_node_id
= numa_node_id
;
1602 md
->use_blk_mq
= dm_use_blk_mq_default();
1603 md
->init_tio_pdu
= false;
1604 md
->type
= DM_TYPE_NONE
;
1605 mutex_init(&md
->suspend_lock
);
1606 mutex_init(&md
->type_lock
);
1607 mutex_init(&md
->table_devices_lock
);
1608 spin_lock_init(&md
->deferred_lock
);
1609 atomic_set(&md
->holders
, 1);
1610 atomic_set(&md
->open_count
, 0);
1611 atomic_set(&md
->event_nr
, 0);
1612 atomic_set(&md
->uevent_seq
, 0);
1613 INIT_LIST_HEAD(&md
->uevent_list
);
1614 INIT_LIST_HEAD(&md
->table_devices
);
1615 spin_lock_init(&md
->uevent_lock
);
1617 md
->queue
= blk_alloc_queue_node(GFP_KERNEL
, numa_node_id
);
1621 dm_init_md_queue(md
);
1623 md
->disk
= alloc_disk_node(1, numa_node_id
);
1627 atomic_set(&md
->pending
[0], 0);
1628 atomic_set(&md
->pending
[1], 0);
1629 init_waitqueue_head(&md
->wait
);
1630 INIT_WORK(&md
->work
, dm_wq_work
);
1631 init_waitqueue_head(&md
->eventq
);
1632 init_completion(&md
->kobj_holder
.completion
);
1633 md
->kworker_task
= NULL
;
1635 md
->disk
->major
= _major
;
1636 md
->disk
->first_minor
= minor
;
1637 md
->disk
->fops
= &dm_blk_dops
;
1638 md
->disk
->queue
= md
->queue
;
1639 md
->disk
->private_data
= md
;
1640 sprintf(md
->disk
->disk_name
, "dm-%d", minor
);
1642 dax_dev
= alloc_dax(md
, md
->disk
->disk_name
, &dm_dax_ops
);
1645 md
->dax_dev
= dax_dev
;
1648 format_dev_t(md
->name
, MKDEV(_major
, minor
));
1650 md
->wq
= alloc_workqueue("kdmflush", WQ_MEM_RECLAIM
, 0);
1654 md
->bdev
= bdget_disk(md
->disk
, 0);
1658 bio_init(&md
->flush_bio
, NULL
, 0);
1659 md
->flush_bio
.bi_bdev
= md
->bdev
;
1660 md
->flush_bio
.bi_opf
= REQ_OP_WRITE
| REQ_PREFLUSH
| REQ_SYNC
;
1662 dm_stats_init(&md
->stats
);
1664 /* Populate the mapping, nobody knows we exist yet */
1665 spin_lock(&_minor_lock
);
1666 old_md
= idr_replace(&_minor_idr
, md
, minor
);
1667 spin_unlock(&_minor_lock
);
1669 BUG_ON(old_md
!= MINOR_ALLOCED
);
1674 cleanup_mapped_device(md
);
1678 module_put(THIS_MODULE
);
1684 static void unlock_fs(struct mapped_device
*md
);
1686 static void free_dev(struct mapped_device
*md
)
1688 int minor
= MINOR(disk_devt(md
->disk
));
1692 cleanup_mapped_device(md
);
1694 free_table_devices(&md
->table_devices
);
1695 dm_stats_cleanup(&md
->stats
);
1698 module_put(THIS_MODULE
);
1702 static void __bind_mempools(struct mapped_device
*md
, struct dm_table
*t
)
1704 struct dm_md_mempools
*p
= dm_table_get_md_mempools(t
);
1707 /* The md already has necessary mempools. */
1708 if (dm_table_bio_based(t
)) {
1710 * Reload bioset because front_pad may have changed
1711 * because a different table was loaded.
1713 bioset_free(md
->bs
);
1718 * There's no need to reload with request-based dm
1719 * because the size of front_pad doesn't change.
1720 * Note for future: If you are to reload bioset,
1721 * prep-ed requests in the queue may refer
1722 * to bio from the old bioset, so you must walk
1723 * through the queue to unprep.
1728 BUG_ON(!p
|| md
->io_pool
|| md
->bs
);
1730 md
->io_pool
= p
->io_pool
;
1736 /* mempool bind completed, no longer need any mempools in the table */
1737 dm_table_free_md_mempools(t
);
1741 * Bind a table to the device.
1743 static void event_callback(void *context
)
1745 unsigned long flags
;
1747 struct mapped_device
*md
= (struct mapped_device
*) context
;
1749 spin_lock_irqsave(&md
->uevent_lock
, flags
);
1750 list_splice_init(&md
->uevent_list
, &uevents
);
1751 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
1753 dm_send_uevents(&uevents
, &disk_to_dev(md
->disk
)->kobj
);
1755 atomic_inc(&md
->event_nr
);
1756 wake_up(&md
->eventq
);
1760 * Protected by md->suspend_lock obtained by dm_swap_table().
1762 static void __set_size(struct mapped_device
*md
, sector_t size
)
1764 lockdep_assert_held(&md
->suspend_lock
);
1766 set_capacity(md
->disk
, size
);
1768 i_size_write(md
->bdev
->bd_inode
, (loff_t
)size
<< SECTOR_SHIFT
);
1772 * Returns old map, which caller must destroy.
1774 static struct dm_table
*__bind(struct mapped_device
*md
, struct dm_table
*t
,
1775 struct queue_limits
*limits
)
1777 struct dm_table
*old_map
;
1778 struct request_queue
*q
= md
->queue
;
1781 lockdep_assert_held(&md
->suspend_lock
);
1783 size
= dm_table_get_size(t
);
1786 * Wipe any geometry if the size of the table changed.
1788 if (size
!= dm_get_size(md
))
1789 memset(&md
->geometry
, 0, sizeof(md
->geometry
));
1791 __set_size(md
, size
);
1793 dm_table_event_callback(t
, event_callback
, md
);
1796 * The queue hasn't been stopped yet, if the old table type wasn't
1797 * for request-based during suspension. So stop it to prevent
1798 * I/O mapping before resume.
1799 * This must be done before setting the queue restrictions,
1800 * because request-based dm may be run just after the setting.
1802 if (dm_table_request_based(t
)) {
1805 * Leverage the fact that request-based DM targets are
1806 * immutable singletons and establish md->immutable_target
1807 * - used to optimize both dm_request_fn and dm_mq_queue_rq
1809 md
->immutable_target
= dm_table_get_immutable_target(t
);
1812 __bind_mempools(md
, t
);
1814 old_map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
1815 rcu_assign_pointer(md
->map
, (void *)t
);
1816 md
->immutable_target_type
= dm_table_get_immutable_target_type(t
);
1818 dm_table_set_restrictions(t
, q
, limits
);
1826 * Returns unbound table for the caller to free.
1828 static struct dm_table
*__unbind(struct mapped_device
*md
)
1830 struct dm_table
*map
= rcu_dereference_protected(md
->map
, 1);
1835 dm_table_event_callback(map
, NULL
, NULL
);
1836 RCU_INIT_POINTER(md
->map
, NULL
);
1843 * Constructor for a new device.
1845 int dm_create(int minor
, struct mapped_device
**result
)
1847 struct mapped_device
*md
;
1849 md
= alloc_dev(minor
);
1860 * Functions to manage md->type.
1861 * All are required to hold md->type_lock.
1863 void dm_lock_md_type(struct mapped_device
*md
)
1865 mutex_lock(&md
->type_lock
);
1868 void dm_unlock_md_type(struct mapped_device
*md
)
1870 mutex_unlock(&md
->type_lock
);
1873 void dm_set_md_type(struct mapped_device
*md
, enum dm_queue_mode type
)
1875 BUG_ON(!mutex_is_locked(&md
->type_lock
));
1879 enum dm_queue_mode
dm_get_md_type(struct mapped_device
*md
)
1884 struct target_type
*dm_get_immutable_target_type(struct mapped_device
*md
)
1886 return md
->immutable_target_type
;
1890 * The queue_limits are only valid as long as you have a reference
1893 struct queue_limits
*dm_get_queue_limits(struct mapped_device
*md
)
1895 BUG_ON(!atomic_read(&md
->holders
));
1896 return &md
->queue
->limits
;
1898 EXPORT_SYMBOL_GPL(dm_get_queue_limits
);
1901 * Setup the DM device's queue based on md's type
1903 int dm_setup_md_queue(struct mapped_device
*md
, struct dm_table
*t
)
1906 enum dm_queue_mode type
= dm_get_md_type(md
);
1909 case DM_TYPE_REQUEST_BASED
:
1910 r
= dm_old_init_request_queue(md
, t
);
1912 DMERR("Cannot initialize queue for request-based mapped device");
1916 case DM_TYPE_MQ_REQUEST_BASED
:
1917 r
= dm_mq_init_request_queue(md
, t
);
1919 DMERR("Cannot initialize queue for request-based dm-mq mapped device");
1923 case DM_TYPE_BIO_BASED
:
1924 case DM_TYPE_DAX_BIO_BASED
:
1925 dm_init_normal_md_queue(md
);
1926 blk_queue_make_request(md
->queue
, dm_make_request
);
1928 * DM handles splitting bios as needed. Free the bio_split bioset
1929 * since it won't be used (saves 1 process per bio-based DM device).
1931 bioset_free(md
->queue
->bio_split
);
1932 md
->queue
->bio_split
= NULL
;
1934 if (type
== DM_TYPE_DAX_BIO_BASED
)
1935 queue_flag_set_unlocked(QUEUE_FLAG_DAX
, md
->queue
);
1945 struct mapped_device
*dm_get_md(dev_t dev
)
1947 struct mapped_device
*md
;
1948 unsigned minor
= MINOR(dev
);
1950 if (MAJOR(dev
) != _major
|| minor
>= (1 << MINORBITS
))
1953 spin_lock(&_minor_lock
);
1955 md
= idr_find(&_minor_idr
, minor
);
1957 if ((md
== MINOR_ALLOCED
||
1958 (MINOR(disk_devt(dm_disk(md
))) != minor
) ||
1959 dm_deleting_md(md
) ||
1960 test_bit(DMF_FREEING
, &md
->flags
))) {
1968 spin_unlock(&_minor_lock
);
1972 EXPORT_SYMBOL_GPL(dm_get_md
);
1974 void *dm_get_mdptr(struct mapped_device
*md
)
1976 return md
->interface_ptr
;
1979 void dm_set_mdptr(struct mapped_device
*md
, void *ptr
)
1981 md
->interface_ptr
= ptr
;
1984 void dm_get(struct mapped_device
*md
)
1986 atomic_inc(&md
->holders
);
1987 BUG_ON(test_bit(DMF_FREEING
, &md
->flags
));
1990 int dm_hold(struct mapped_device
*md
)
1992 spin_lock(&_minor_lock
);
1993 if (test_bit(DMF_FREEING
, &md
->flags
)) {
1994 spin_unlock(&_minor_lock
);
1998 spin_unlock(&_minor_lock
);
2001 EXPORT_SYMBOL_GPL(dm_hold
);
2003 const char *dm_device_name(struct mapped_device
*md
)
2007 EXPORT_SYMBOL_GPL(dm_device_name
);
2009 static void __dm_destroy(struct mapped_device
*md
, bool wait
)
2011 struct request_queue
*q
= dm_get_md_queue(md
);
2012 struct dm_table
*map
;
2017 spin_lock(&_minor_lock
);
2018 idr_replace(&_minor_idr
, MINOR_ALLOCED
, MINOR(disk_devt(dm_disk(md
))));
2019 set_bit(DMF_FREEING
, &md
->flags
);
2020 spin_unlock(&_minor_lock
);
2022 blk_set_queue_dying(q
);
2024 if (dm_request_based(md
) && md
->kworker_task
)
2025 kthread_flush_worker(&md
->kworker
);
2028 * Take suspend_lock so that presuspend and postsuspend methods
2029 * do not race with internal suspend.
2031 mutex_lock(&md
->suspend_lock
);
2032 map
= dm_get_live_table(md
, &srcu_idx
);
2033 if (!dm_suspended_md(md
)) {
2034 dm_table_presuspend_targets(map
);
2035 dm_table_postsuspend_targets(map
);
2037 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2038 dm_put_live_table(md
, srcu_idx
);
2039 mutex_unlock(&md
->suspend_lock
);
2042 * Rare, but there may be I/O requests still going to complete,
2043 * for example. Wait for all references to disappear.
2044 * No one should increment the reference count of the mapped_device,
2045 * after the mapped_device state becomes DMF_FREEING.
2048 while (atomic_read(&md
->holders
))
2050 else if (atomic_read(&md
->holders
))
2051 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2052 dm_device_name(md
), atomic_read(&md
->holders
));
2055 dm_table_destroy(__unbind(md
));
2059 void dm_destroy(struct mapped_device
*md
)
2061 __dm_destroy(md
, true);
2064 void dm_destroy_immediate(struct mapped_device
*md
)
2066 __dm_destroy(md
, false);
2069 void dm_put(struct mapped_device
*md
)
2071 atomic_dec(&md
->holders
);
2073 EXPORT_SYMBOL_GPL(dm_put
);
2075 static int dm_wait_for_completion(struct mapped_device
*md
, long task_state
)
2081 prepare_to_wait(&md
->wait
, &wait
, task_state
);
2083 if (!md_in_flight(md
))
2086 if (signal_pending_state(task_state
, current
)) {
2093 finish_wait(&md
->wait
, &wait
);
2099 * Process the deferred bios
2101 static void dm_wq_work(struct work_struct
*work
)
2103 struct mapped_device
*md
= container_of(work
, struct mapped_device
,
2107 struct dm_table
*map
;
2109 map
= dm_get_live_table(md
, &srcu_idx
);
2111 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
2112 spin_lock_irq(&md
->deferred_lock
);
2113 c
= bio_list_pop(&md
->deferred
);
2114 spin_unlock_irq(&md
->deferred_lock
);
2119 if (dm_request_based(md
))
2120 generic_make_request(c
);
2122 __split_and_process_bio(md
, map
, c
);
2125 dm_put_live_table(md
, srcu_idx
);
2128 static void dm_queue_flush(struct mapped_device
*md
)
2130 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2131 smp_mb__after_atomic();
2132 queue_work(md
->wq
, &md
->work
);
2136 * Swap in a new table, returning the old one for the caller to destroy.
2138 struct dm_table
*dm_swap_table(struct mapped_device
*md
, struct dm_table
*table
)
2140 struct dm_table
*live_map
= NULL
, *map
= ERR_PTR(-EINVAL
);
2141 struct queue_limits limits
;
2144 mutex_lock(&md
->suspend_lock
);
2146 /* device must be suspended */
2147 if (!dm_suspended_md(md
))
2151 * If the new table has no data devices, retain the existing limits.
2152 * This helps multipath with queue_if_no_path if all paths disappear,
2153 * then new I/O is queued based on these limits, and then some paths
2156 if (dm_table_has_no_data_devices(table
)) {
2157 live_map
= dm_get_live_table_fast(md
);
2159 limits
= md
->queue
->limits
;
2160 dm_put_live_table_fast(md
);
2164 r
= dm_calculate_queue_limits(table
, &limits
);
2171 map
= __bind(md
, table
, &limits
);
2174 mutex_unlock(&md
->suspend_lock
);
2179 * Functions to lock and unlock any filesystem running on the
2182 static int lock_fs(struct mapped_device
*md
)
2186 WARN_ON(md
->frozen_sb
);
2188 md
->frozen_sb
= freeze_bdev(md
->bdev
);
2189 if (IS_ERR(md
->frozen_sb
)) {
2190 r
= PTR_ERR(md
->frozen_sb
);
2191 md
->frozen_sb
= NULL
;
2195 set_bit(DMF_FROZEN
, &md
->flags
);
2200 static void unlock_fs(struct mapped_device
*md
)
2202 if (!test_bit(DMF_FROZEN
, &md
->flags
))
2205 thaw_bdev(md
->bdev
, md
->frozen_sb
);
2206 md
->frozen_sb
= NULL
;
2207 clear_bit(DMF_FROZEN
, &md
->flags
);
2211 * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG
2212 * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE
2213 * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY
2215 * If __dm_suspend returns 0, the device is completely quiescent
2216 * now. There is no request-processing activity. All new requests
2217 * are being added to md->deferred list.
2219 static int __dm_suspend(struct mapped_device
*md
, struct dm_table
*map
,
2220 unsigned suspend_flags
, long task_state
,
2221 int dmf_suspended_flag
)
2223 bool do_lockfs
= suspend_flags
& DM_SUSPEND_LOCKFS_FLAG
;
2224 bool noflush
= suspend_flags
& DM_SUSPEND_NOFLUSH_FLAG
;
2227 lockdep_assert_held(&md
->suspend_lock
);
2230 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2231 * This flag is cleared before dm_suspend returns.
2234 set_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2236 pr_debug("%s: suspending with flush\n", dm_device_name(md
));
2239 * This gets reverted if there's an error later and the targets
2240 * provide the .presuspend_undo hook.
2242 dm_table_presuspend_targets(map
);
2245 * Flush I/O to the device.
2246 * Any I/O submitted after lock_fs() may not be flushed.
2247 * noflush takes precedence over do_lockfs.
2248 * (lock_fs() flushes I/Os and waits for them to complete.)
2250 if (!noflush
&& do_lockfs
) {
2253 dm_table_presuspend_undo_targets(map
);
2259 * Here we must make sure that no processes are submitting requests
2260 * to target drivers i.e. no one may be executing
2261 * __split_and_process_bio. This is called from dm_request and
2264 * To get all processes out of __split_and_process_bio in dm_request,
2265 * we take the write lock. To prevent any process from reentering
2266 * __split_and_process_bio from dm_request and quiesce the thread
2267 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2268 * flush_workqueue(md->wq).
2270 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2272 synchronize_srcu(&md
->io_barrier
);
2275 * Stop md->queue before flushing md->wq in case request-based
2276 * dm defers requests to md->wq from md->queue.
2278 if (dm_request_based(md
)) {
2279 dm_stop_queue(md
->queue
);
2280 if (md
->kworker_task
)
2281 kthread_flush_worker(&md
->kworker
);
2284 flush_workqueue(md
->wq
);
2287 * At this point no more requests are entering target request routines.
2288 * We call dm_wait_for_completion to wait for all existing requests
2291 r
= dm_wait_for_completion(md
, task_state
);
2293 set_bit(dmf_suspended_flag
, &md
->flags
);
2296 clear_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2298 synchronize_srcu(&md
->io_barrier
);
2300 /* were we interrupted ? */
2304 if (dm_request_based(md
))
2305 dm_start_queue(md
->queue
);
2308 dm_table_presuspend_undo_targets(map
);
2309 /* pushback list is already flushed, so skip flush */
2316 * We need to be able to change a mapping table under a mounted
2317 * filesystem. For example we might want to move some data in
2318 * the background. Before the table can be swapped with
2319 * dm_bind_table, dm_suspend must be called to flush any in
2320 * flight bios and ensure that any further io gets deferred.
2323 * Suspend mechanism in request-based dm.
2325 * 1. Flush all I/Os by lock_fs() if needed.
2326 * 2. Stop dispatching any I/O by stopping the request_queue.
2327 * 3. Wait for all in-flight I/Os to be completed or requeued.
2329 * To abort suspend, start the request_queue.
2331 int dm_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
2333 struct dm_table
*map
= NULL
;
2337 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
2339 if (dm_suspended_md(md
)) {
2344 if (dm_suspended_internally_md(md
)) {
2345 /* already internally suspended, wait for internal resume */
2346 mutex_unlock(&md
->suspend_lock
);
2347 r
= wait_on_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
, TASK_INTERRUPTIBLE
);
2353 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
2355 r
= __dm_suspend(md
, map
, suspend_flags
, TASK_INTERRUPTIBLE
, DMF_SUSPENDED
);
2359 dm_table_postsuspend_targets(map
);
2362 mutex_unlock(&md
->suspend_lock
);
2366 static int __dm_resume(struct mapped_device
*md
, struct dm_table
*map
)
2369 int r
= dm_table_resume_targets(map
);
2377 * Flushing deferred I/Os must be done after targets are resumed
2378 * so that mapping of targets can work correctly.
2379 * Request-based dm is queueing the deferred I/Os in its request_queue.
2381 if (dm_request_based(md
))
2382 dm_start_queue(md
->queue
);
2389 int dm_resume(struct mapped_device
*md
)
2392 struct dm_table
*map
= NULL
;
2396 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
2398 if (!dm_suspended_md(md
))
2401 if (dm_suspended_internally_md(md
)) {
2402 /* already internally suspended, wait for internal resume */
2403 mutex_unlock(&md
->suspend_lock
);
2404 r
= wait_on_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
, TASK_INTERRUPTIBLE
);
2410 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
2411 if (!map
|| !dm_table_get_size(map
))
2414 r
= __dm_resume(md
, map
);
2418 clear_bit(DMF_SUSPENDED
, &md
->flags
);
2420 mutex_unlock(&md
->suspend_lock
);
2426 * Internal suspend/resume works like userspace-driven suspend. It waits
2427 * until all bios finish and prevents issuing new bios to the target drivers.
2428 * It may be used only from the kernel.
2431 static void __dm_internal_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
2433 struct dm_table
*map
= NULL
;
2435 lockdep_assert_held(&md
->suspend_lock
);
2437 if (md
->internal_suspend_count
++)
2438 return; /* nested internal suspend */
2440 if (dm_suspended_md(md
)) {
2441 set_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
2442 return; /* nest suspend */
2445 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
2448 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
2449 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
2450 * would require changing .presuspend to return an error -- avoid this
2451 * until there is a need for more elaborate variants of internal suspend.
2453 (void) __dm_suspend(md
, map
, suspend_flags
, TASK_UNINTERRUPTIBLE
,
2454 DMF_SUSPENDED_INTERNALLY
);
2456 dm_table_postsuspend_targets(map
);
2459 static void __dm_internal_resume(struct mapped_device
*md
)
2461 BUG_ON(!md
->internal_suspend_count
);
2463 if (--md
->internal_suspend_count
)
2464 return; /* resume from nested internal suspend */
2466 if (dm_suspended_md(md
))
2467 goto done
; /* resume from nested suspend */
2470 * NOTE: existing callers don't need to call dm_table_resume_targets
2471 * (which may fail -- so best to avoid it for now by passing NULL map)
2473 (void) __dm_resume(md
, NULL
);
2476 clear_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
2477 smp_mb__after_atomic();
2478 wake_up_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
);
2481 void dm_internal_suspend_noflush(struct mapped_device
*md
)
2483 mutex_lock(&md
->suspend_lock
);
2484 __dm_internal_suspend(md
, DM_SUSPEND_NOFLUSH_FLAG
);
2485 mutex_unlock(&md
->suspend_lock
);
2487 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush
);
2489 void dm_internal_resume(struct mapped_device
*md
)
2491 mutex_lock(&md
->suspend_lock
);
2492 __dm_internal_resume(md
);
2493 mutex_unlock(&md
->suspend_lock
);
2495 EXPORT_SYMBOL_GPL(dm_internal_resume
);
2498 * Fast variants of internal suspend/resume hold md->suspend_lock,
2499 * which prevents interaction with userspace-driven suspend.
2502 void dm_internal_suspend_fast(struct mapped_device
*md
)
2504 mutex_lock(&md
->suspend_lock
);
2505 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
2508 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2509 synchronize_srcu(&md
->io_barrier
);
2510 flush_workqueue(md
->wq
);
2511 dm_wait_for_completion(md
, TASK_UNINTERRUPTIBLE
);
2513 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast
);
2515 void dm_internal_resume_fast(struct mapped_device
*md
)
2517 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
2523 mutex_unlock(&md
->suspend_lock
);
2525 EXPORT_SYMBOL_GPL(dm_internal_resume_fast
);
2527 /*-----------------------------------------------------------------
2528 * Event notification.
2529 *---------------------------------------------------------------*/
2530 int dm_kobject_uevent(struct mapped_device
*md
, enum kobject_action action
,
2533 char udev_cookie
[DM_COOKIE_LENGTH
];
2534 char *envp
[] = { udev_cookie
, NULL
};
2537 return kobject_uevent(&disk_to_dev(md
->disk
)->kobj
, action
);
2539 snprintf(udev_cookie
, DM_COOKIE_LENGTH
, "%s=%u",
2540 DM_COOKIE_ENV_VAR_NAME
, cookie
);
2541 return kobject_uevent_env(&disk_to_dev(md
->disk
)->kobj
,
2546 uint32_t dm_next_uevent_seq(struct mapped_device
*md
)
2548 return atomic_add_return(1, &md
->uevent_seq
);
2551 uint32_t dm_get_event_nr(struct mapped_device
*md
)
2553 return atomic_read(&md
->event_nr
);
2556 int dm_wait_event(struct mapped_device
*md
, int event_nr
)
2558 return wait_event_interruptible(md
->eventq
,
2559 (event_nr
!= atomic_read(&md
->event_nr
)));
2562 void dm_uevent_add(struct mapped_device
*md
, struct list_head
*elist
)
2564 unsigned long flags
;
2566 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2567 list_add(elist
, &md
->uevent_list
);
2568 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2572 * The gendisk is only valid as long as you have a reference
2575 struct gendisk
*dm_disk(struct mapped_device
*md
)
2579 EXPORT_SYMBOL_GPL(dm_disk
);
2581 struct kobject
*dm_kobject(struct mapped_device
*md
)
2583 return &md
->kobj_holder
.kobj
;
2586 struct mapped_device
*dm_get_from_kobject(struct kobject
*kobj
)
2588 struct mapped_device
*md
;
2590 md
= container_of(kobj
, struct mapped_device
, kobj_holder
.kobj
);
2592 if (test_bit(DMF_FREEING
, &md
->flags
) ||
2600 int dm_suspended_md(struct mapped_device
*md
)
2602 return test_bit(DMF_SUSPENDED
, &md
->flags
);
2605 int dm_suspended_internally_md(struct mapped_device
*md
)
2607 return test_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
2610 int dm_test_deferred_remove_flag(struct mapped_device
*md
)
2612 return test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
2615 int dm_suspended(struct dm_target
*ti
)
2617 return dm_suspended_md(dm_table_get_md(ti
->table
));
2619 EXPORT_SYMBOL_GPL(dm_suspended
);
2621 int dm_noflush_suspending(struct dm_target
*ti
)
2623 return __noflush_suspending(dm_table_get_md(ti
->table
));
2625 EXPORT_SYMBOL_GPL(dm_noflush_suspending
);
2627 struct dm_md_mempools
*dm_alloc_md_mempools(struct mapped_device
*md
, enum dm_queue_mode type
,
2628 unsigned integrity
, unsigned per_io_data_size
)
2630 struct dm_md_mempools
*pools
= kzalloc_node(sizeof(*pools
), GFP_KERNEL
, md
->numa_node_id
);
2631 unsigned int pool_size
= 0;
2632 unsigned int front_pad
;
2638 case DM_TYPE_BIO_BASED
:
2639 case DM_TYPE_DAX_BIO_BASED
:
2640 pool_size
= dm_get_reserved_bio_based_ios();
2641 front_pad
= roundup(per_io_data_size
, __alignof__(struct dm_target_io
)) + offsetof(struct dm_target_io
, clone
);
2643 pools
->io_pool
= mempool_create_slab_pool(pool_size
, _io_cache
);
2644 if (!pools
->io_pool
)
2647 case DM_TYPE_REQUEST_BASED
:
2648 case DM_TYPE_MQ_REQUEST_BASED
:
2649 pool_size
= dm_get_reserved_rq_based_ios();
2650 front_pad
= offsetof(struct dm_rq_clone_bio_info
, clone
);
2651 /* per_io_data_size is used for blk-mq pdu at queue allocation */
2657 pools
->bs
= bioset_create_nobvec(pool_size
, front_pad
);
2661 if (integrity
&& bioset_integrity_create(pools
->bs
, pool_size
))
2667 dm_free_md_mempools(pools
);
2672 void dm_free_md_mempools(struct dm_md_mempools
*pools
)
2677 mempool_destroy(pools
->io_pool
);
2680 bioset_free(pools
->bs
);
2692 static int dm_call_pr(struct block_device
*bdev
, iterate_devices_callout_fn fn
,
2695 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2696 struct dm_table
*table
;
2697 struct dm_target
*ti
;
2698 int ret
= -ENOTTY
, srcu_idx
;
2700 table
= dm_get_live_table(md
, &srcu_idx
);
2701 if (!table
|| !dm_table_get_size(table
))
2704 /* We only support devices that have a single target */
2705 if (dm_table_get_num_targets(table
) != 1)
2707 ti
= dm_table_get_target(table
, 0);
2710 if (!ti
->type
->iterate_devices
)
2713 ret
= ti
->type
->iterate_devices(ti
, fn
, data
);
2715 dm_put_live_table(md
, srcu_idx
);
2720 * For register / unregister we need to manually call out to every path.
2722 static int __dm_pr_register(struct dm_target
*ti
, struct dm_dev
*dev
,
2723 sector_t start
, sector_t len
, void *data
)
2725 struct dm_pr
*pr
= data
;
2726 const struct pr_ops
*ops
= dev
->bdev
->bd_disk
->fops
->pr_ops
;
2728 if (!ops
|| !ops
->pr_register
)
2730 return ops
->pr_register(dev
->bdev
, pr
->old_key
, pr
->new_key
, pr
->flags
);
2733 static int dm_pr_register(struct block_device
*bdev
, u64 old_key
, u64 new_key
,
2744 ret
= dm_call_pr(bdev
, __dm_pr_register
, &pr
);
2745 if (ret
&& new_key
) {
2746 /* unregister all paths if we failed to register any path */
2747 pr
.old_key
= new_key
;
2750 pr
.fail_early
= false;
2751 dm_call_pr(bdev
, __dm_pr_register
, &pr
);
2757 static int dm_pr_reserve(struct block_device
*bdev
, u64 key
, enum pr_type type
,
2760 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2761 const struct pr_ops
*ops
;
2765 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
2769 ops
= bdev
->bd_disk
->fops
->pr_ops
;
2770 if (ops
&& ops
->pr_reserve
)
2771 r
= ops
->pr_reserve(bdev
, key
, type
, flags
);
2779 static int dm_pr_release(struct block_device
*bdev
, u64 key
, enum pr_type type
)
2781 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2782 const struct pr_ops
*ops
;
2786 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
2790 ops
= bdev
->bd_disk
->fops
->pr_ops
;
2791 if (ops
&& ops
->pr_release
)
2792 r
= ops
->pr_release(bdev
, key
, type
);
2800 static int dm_pr_preempt(struct block_device
*bdev
, u64 old_key
, u64 new_key
,
2801 enum pr_type type
, bool abort
)
2803 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2804 const struct pr_ops
*ops
;
2808 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
2812 ops
= bdev
->bd_disk
->fops
->pr_ops
;
2813 if (ops
&& ops
->pr_preempt
)
2814 r
= ops
->pr_preempt(bdev
, old_key
, new_key
, type
, abort
);
2822 static int dm_pr_clear(struct block_device
*bdev
, u64 key
)
2824 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2825 const struct pr_ops
*ops
;
2829 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
2833 ops
= bdev
->bd_disk
->fops
->pr_ops
;
2834 if (ops
&& ops
->pr_clear
)
2835 r
= ops
->pr_clear(bdev
, key
);
2843 static const struct pr_ops dm_pr_ops
= {
2844 .pr_register
= dm_pr_register
,
2845 .pr_reserve
= dm_pr_reserve
,
2846 .pr_release
= dm_pr_release
,
2847 .pr_preempt
= dm_pr_preempt
,
2848 .pr_clear
= dm_pr_clear
,
2851 static const struct block_device_operations dm_blk_dops
= {
2852 .open
= dm_blk_open
,
2853 .release
= dm_blk_close
,
2854 .ioctl
= dm_blk_ioctl
,
2855 .getgeo
= dm_blk_getgeo
,
2856 .pr_ops
= &dm_pr_ops
,
2857 .owner
= THIS_MODULE
2860 static const struct dax_operations dm_dax_ops
= {
2861 .direct_access
= dm_dax_direct_access
,
2867 module_init(dm_init
);
2868 module_exit(dm_exit
);
2870 module_param(major
, uint
, 0);
2871 MODULE_PARM_DESC(major
, "The major number of the device mapper");
2873 module_param(reserved_bio_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
2874 MODULE_PARM_DESC(reserved_bio_based_ios
, "Reserved IOs in bio-based mempools");
2876 module_param(dm_numa_node
, int, S_IRUGO
| S_IWUSR
);
2877 MODULE_PARM_DESC(dm_numa_node
, "NUMA node for DM device memory allocations");
2879 MODULE_DESCRIPTION(DM_NAME
" driver");
2880 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
2881 MODULE_LICENSE("GPL");