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/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>
25 #define DM_MSG_PREFIX "core"
29 * ratelimit state to be used in DMXXX_LIMIT().
31 DEFINE_RATELIMIT_STATE(dm_ratelimit_state
,
32 DEFAULT_RATELIMIT_INTERVAL
,
33 DEFAULT_RATELIMIT_BURST
);
34 EXPORT_SYMBOL(dm_ratelimit_state
);
38 * Cookies are numeric values sent with CHANGE and REMOVE
39 * uevents while resuming, removing or renaming the device.
41 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
42 #define DM_COOKIE_LENGTH 24
44 static const char *_name
= DM_NAME
;
46 static unsigned int major
= 0;
47 static unsigned int _major
= 0;
49 static DEFINE_IDR(_minor_idr
);
51 static DEFINE_SPINLOCK(_minor_lock
);
53 static void do_deferred_remove(struct work_struct
*w
);
55 static DECLARE_WORK(deferred_remove_work
, do_deferred_remove
);
57 static struct workqueue_struct
*deferred_remove_workqueue
;
60 * One of these is allocated per bio.
63 struct mapped_device
*md
;
67 unsigned long start_time
;
68 spinlock_t endio_lock
;
69 struct dm_stats_aux stats_aux
;
72 #define MINOR_ALLOCED ((void *)-1)
75 * Bits for the md->flags field.
77 #define DMF_BLOCK_IO_FOR_SUSPEND 0
78 #define DMF_SUSPENDED 1
81 #define DMF_DELETING 4
82 #define DMF_NOFLUSH_SUSPENDING 5
83 #define DMF_DEFERRED_REMOVE 6
84 #define DMF_SUSPENDED_INTERNALLY 7
86 #define DM_NUMA_NODE NUMA_NO_NODE
87 static int dm_numa_node
= DM_NUMA_NODE
;
90 * For mempools pre-allocation at the table loading time.
92 struct dm_md_mempools
{
99 struct list_head list
;
101 struct dm_dev dm_dev
;
104 static struct kmem_cache
*_io_cache
;
105 static struct kmem_cache
*_rq_tio_cache
;
106 static struct kmem_cache
*_rq_cache
;
109 * Bio-based DM's mempools' reserved IOs set by the user.
111 #define RESERVED_BIO_BASED_IOS 16
112 static unsigned reserved_bio_based_ios
= RESERVED_BIO_BASED_IOS
;
114 static int __dm_get_module_param_int(int *module_param
, int min
, int max
)
116 int param
= ACCESS_ONCE(*module_param
);
117 int modified_param
= 0;
118 bool modified
= true;
121 modified_param
= min
;
122 else if (param
> max
)
123 modified_param
= max
;
128 (void)cmpxchg(module_param
, param
, modified_param
);
129 param
= modified_param
;
135 unsigned __dm_get_module_param(unsigned *module_param
,
136 unsigned def
, unsigned max
)
138 unsigned param
= ACCESS_ONCE(*module_param
);
139 unsigned modified_param
= 0;
142 modified_param
= def
;
143 else if (param
> max
)
144 modified_param
= max
;
146 if (modified_param
) {
147 (void)cmpxchg(module_param
, param
, modified_param
);
148 param
= modified_param
;
154 unsigned dm_get_reserved_bio_based_ios(void)
156 return __dm_get_module_param(&reserved_bio_based_ios
,
157 RESERVED_BIO_BASED_IOS
, DM_RESERVED_MAX_IOS
);
159 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios
);
161 static unsigned dm_get_numa_node(void)
163 return __dm_get_module_param_int(&dm_numa_node
,
164 DM_NUMA_NODE
, num_online_nodes() - 1);
167 static int __init
local_init(void)
171 /* allocate a slab for the dm_ios */
172 _io_cache
= KMEM_CACHE(dm_io
, 0);
176 _rq_tio_cache
= KMEM_CACHE(dm_rq_target_io
, 0);
178 goto out_free_io_cache
;
180 _rq_cache
= kmem_cache_create("dm_old_clone_request", sizeof(struct request
),
181 __alignof__(struct request
), 0, NULL
);
183 goto out_free_rq_tio_cache
;
185 r
= dm_uevent_init();
187 goto out_free_rq_cache
;
189 deferred_remove_workqueue
= alloc_workqueue("kdmremove", WQ_UNBOUND
, 1);
190 if (!deferred_remove_workqueue
) {
192 goto out_uevent_exit
;
196 r
= register_blkdev(_major
, _name
);
198 goto out_free_workqueue
;
206 destroy_workqueue(deferred_remove_workqueue
);
210 kmem_cache_destroy(_rq_cache
);
211 out_free_rq_tio_cache
:
212 kmem_cache_destroy(_rq_tio_cache
);
214 kmem_cache_destroy(_io_cache
);
219 static void local_exit(void)
221 flush_scheduled_work();
222 destroy_workqueue(deferred_remove_workqueue
);
224 kmem_cache_destroy(_rq_cache
);
225 kmem_cache_destroy(_rq_tio_cache
);
226 kmem_cache_destroy(_io_cache
);
227 unregister_blkdev(_major
, _name
);
232 DMINFO("cleaned up");
235 static int (*_inits
[])(void) __initdata
= {
246 static void (*_exits
[])(void) = {
257 static int __init
dm_init(void)
259 const int count
= ARRAY_SIZE(_inits
);
263 for (i
= 0; i
< count
; i
++) {
278 static void __exit
dm_exit(void)
280 int i
= ARRAY_SIZE(_exits
);
286 * Should be empty by this point.
288 idr_destroy(&_minor_idr
);
292 * Block device functions
294 int dm_deleting_md(struct mapped_device
*md
)
296 return test_bit(DMF_DELETING
, &md
->flags
);
299 static int dm_blk_open(struct block_device
*bdev
, fmode_t mode
)
301 struct mapped_device
*md
;
303 spin_lock(&_minor_lock
);
305 md
= bdev
->bd_disk
->private_data
;
309 if (test_bit(DMF_FREEING
, &md
->flags
) ||
310 dm_deleting_md(md
)) {
316 atomic_inc(&md
->open_count
);
318 spin_unlock(&_minor_lock
);
320 return md
? 0 : -ENXIO
;
323 static void dm_blk_close(struct gendisk
*disk
, fmode_t mode
)
325 struct mapped_device
*md
;
327 spin_lock(&_minor_lock
);
329 md
= disk
->private_data
;
333 if (atomic_dec_and_test(&md
->open_count
) &&
334 (test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
)))
335 queue_work(deferred_remove_workqueue
, &deferred_remove_work
);
339 spin_unlock(&_minor_lock
);
342 int dm_open_count(struct mapped_device
*md
)
344 return atomic_read(&md
->open_count
);
348 * Guarantees nothing is using the device before it's deleted.
350 int dm_lock_for_deletion(struct mapped_device
*md
, bool mark_deferred
, bool only_deferred
)
354 spin_lock(&_minor_lock
);
356 if (dm_open_count(md
)) {
359 set_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
360 } else if (only_deferred
&& !test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
))
363 set_bit(DMF_DELETING
, &md
->flags
);
365 spin_unlock(&_minor_lock
);
370 int dm_cancel_deferred_remove(struct mapped_device
*md
)
374 spin_lock(&_minor_lock
);
376 if (test_bit(DMF_DELETING
, &md
->flags
))
379 clear_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
381 spin_unlock(&_minor_lock
);
386 static void do_deferred_remove(struct work_struct
*w
)
388 dm_deferred_remove();
391 sector_t
dm_get_size(struct mapped_device
*md
)
393 return get_capacity(md
->disk
);
396 struct request_queue
*dm_get_md_queue(struct mapped_device
*md
)
401 struct dm_stats
*dm_get_stats(struct mapped_device
*md
)
406 static int dm_blk_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
408 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
410 return dm_get_geometry(md
, geo
);
413 static int dm_grab_bdev_for_ioctl(struct mapped_device
*md
,
414 struct block_device
**bdev
,
417 struct dm_target
*tgt
;
418 struct dm_table
*map
;
423 map
= dm_get_live_table(md
, &srcu_idx
);
424 if (!map
|| !dm_table_get_size(map
))
427 /* We only support devices that have a single target */
428 if (dm_table_get_num_targets(map
) != 1)
431 tgt
= dm_table_get_target(map
, 0);
432 if (!tgt
->type
->prepare_ioctl
)
435 if (dm_suspended_md(md
)) {
440 r
= tgt
->type
->prepare_ioctl(tgt
, bdev
, mode
);
445 dm_put_live_table(md
, srcu_idx
);
449 dm_put_live_table(md
, srcu_idx
);
450 if (r
== -ENOTCONN
&& !fatal_signal_pending(current
)) {
457 static int dm_blk_ioctl(struct block_device
*bdev
, fmode_t mode
,
458 unsigned int cmd
, unsigned long arg
)
460 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
463 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
469 * Target determined this ioctl is being issued against
470 * a logical partition of the parent bdev; so extra
471 * validation is needed.
473 r
= scsi_verify_blk_ioctl(NULL
, cmd
);
478 r
= __blkdev_driver_ioctl(bdev
, mode
, cmd
, arg
);
484 static struct dm_io
*alloc_io(struct mapped_device
*md
)
486 return mempool_alloc(md
->io_pool
, GFP_NOIO
);
489 static void free_io(struct mapped_device
*md
, struct dm_io
*io
)
491 mempool_free(io
, md
->io_pool
);
494 static void free_tio(struct dm_target_io
*tio
)
496 bio_put(&tio
->clone
);
499 int md_in_flight(struct mapped_device
*md
)
501 return atomic_read(&md
->pending
[READ
]) +
502 atomic_read(&md
->pending
[WRITE
]);
505 static void start_io_acct(struct dm_io
*io
)
507 struct mapped_device
*md
= io
->md
;
508 struct bio
*bio
= io
->bio
;
510 int rw
= bio_data_dir(bio
);
512 io
->start_time
= jiffies
;
514 cpu
= part_stat_lock();
515 part_round_stats(cpu
, &dm_disk(md
)->part0
);
517 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
],
518 atomic_inc_return(&md
->pending
[rw
]));
520 if (unlikely(dm_stats_used(&md
->stats
)))
521 dm_stats_account_io(&md
->stats
, bio_data_dir(bio
),
522 bio
->bi_iter
.bi_sector
, bio_sectors(bio
),
523 false, 0, &io
->stats_aux
);
526 static void end_io_acct(struct dm_io
*io
)
528 struct mapped_device
*md
= io
->md
;
529 struct bio
*bio
= io
->bio
;
530 unsigned long duration
= jiffies
- io
->start_time
;
532 int rw
= bio_data_dir(bio
);
534 generic_end_io_acct(rw
, &dm_disk(md
)->part0
, io
->start_time
);
536 if (unlikely(dm_stats_used(&md
->stats
)))
537 dm_stats_account_io(&md
->stats
, bio_data_dir(bio
),
538 bio
->bi_iter
.bi_sector
, bio_sectors(bio
),
539 true, duration
, &io
->stats_aux
);
542 * After this is decremented the bio must not be touched if it is
545 pending
= atomic_dec_return(&md
->pending
[rw
]);
546 atomic_set(&dm_disk(md
)->part0
.in_flight
[rw
], pending
);
547 pending
+= atomic_read(&md
->pending
[rw
^0x1]);
549 /* nudge anyone waiting on suspend queue */
555 * Add the bio to the list of deferred io.
557 static void queue_io(struct mapped_device
*md
, struct bio
*bio
)
561 spin_lock_irqsave(&md
->deferred_lock
, flags
);
562 bio_list_add(&md
->deferred
, bio
);
563 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
564 queue_work(md
->wq
, &md
->work
);
568 * Everyone (including functions in this file), should use this
569 * function to access the md->map field, and make sure they call
570 * dm_put_live_table() when finished.
572 struct dm_table
*dm_get_live_table(struct mapped_device
*md
, int *srcu_idx
) __acquires(md
->io_barrier
)
574 *srcu_idx
= srcu_read_lock(&md
->io_barrier
);
576 return srcu_dereference(md
->map
, &md
->io_barrier
);
579 void dm_put_live_table(struct mapped_device
*md
, int srcu_idx
) __releases(md
->io_barrier
)
581 srcu_read_unlock(&md
->io_barrier
, srcu_idx
);
584 void dm_sync_table(struct mapped_device
*md
)
586 synchronize_srcu(&md
->io_barrier
);
587 synchronize_rcu_expedited();
591 * A fast alternative to dm_get_live_table/dm_put_live_table.
592 * The caller must not block between these two functions.
594 static struct dm_table
*dm_get_live_table_fast(struct mapped_device
*md
) __acquires(RCU
)
597 return rcu_dereference(md
->map
);
600 static void dm_put_live_table_fast(struct mapped_device
*md
) __releases(RCU
)
606 * Open a table device so we can use it as a map destination.
608 static int open_table_device(struct table_device
*td
, dev_t dev
,
609 struct mapped_device
*md
)
611 static char *_claim_ptr
= "I belong to device-mapper";
612 struct block_device
*bdev
;
616 BUG_ON(td
->dm_dev
.bdev
);
618 bdev
= blkdev_get_by_dev(dev
, td
->dm_dev
.mode
| FMODE_EXCL
, _claim_ptr
);
620 return PTR_ERR(bdev
);
622 r
= bd_link_disk_holder(bdev
, dm_disk(md
));
624 blkdev_put(bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
628 td
->dm_dev
.bdev
= bdev
;
633 * Close a table device that we've been using.
635 static void close_table_device(struct table_device
*td
, struct mapped_device
*md
)
637 if (!td
->dm_dev
.bdev
)
640 bd_unlink_disk_holder(td
->dm_dev
.bdev
, dm_disk(md
));
641 blkdev_put(td
->dm_dev
.bdev
, td
->dm_dev
.mode
| FMODE_EXCL
);
642 td
->dm_dev
.bdev
= NULL
;
645 static struct table_device
*find_table_device(struct list_head
*l
, dev_t dev
,
647 struct table_device
*td
;
649 list_for_each_entry(td
, l
, list
)
650 if (td
->dm_dev
.bdev
->bd_dev
== dev
&& td
->dm_dev
.mode
== mode
)
656 int dm_get_table_device(struct mapped_device
*md
, dev_t dev
, fmode_t mode
,
657 struct dm_dev
**result
) {
659 struct table_device
*td
;
661 mutex_lock(&md
->table_devices_lock
);
662 td
= find_table_device(&md
->table_devices
, dev
, mode
);
664 td
= kmalloc_node(sizeof(*td
), GFP_KERNEL
, md
->numa_node_id
);
666 mutex_unlock(&md
->table_devices_lock
);
670 td
->dm_dev
.mode
= mode
;
671 td
->dm_dev
.bdev
= NULL
;
673 if ((r
= open_table_device(td
, dev
, md
))) {
674 mutex_unlock(&md
->table_devices_lock
);
679 format_dev_t(td
->dm_dev
.name
, dev
);
681 atomic_set(&td
->count
, 0);
682 list_add(&td
->list
, &md
->table_devices
);
684 atomic_inc(&td
->count
);
685 mutex_unlock(&md
->table_devices_lock
);
687 *result
= &td
->dm_dev
;
690 EXPORT_SYMBOL_GPL(dm_get_table_device
);
692 void dm_put_table_device(struct mapped_device
*md
, struct dm_dev
*d
)
694 struct table_device
*td
= container_of(d
, struct table_device
, dm_dev
);
696 mutex_lock(&md
->table_devices_lock
);
697 if (atomic_dec_and_test(&td
->count
)) {
698 close_table_device(td
, md
);
702 mutex_unlock(&md
->table_devices_lock
);
704 EXPORT_SYMBOL(dm_put_table_device
);
706 static void free_table_devices(struct list_head
*devices
)
708 struct list_head
*tmp
, *next
;
710 list_for_each_safe(tmp
, next
, devices
) {
711 struct table_device
*td
= list_entry(tmp
, struct table_device
, list
);
713 DMWARN("dm_destroy: %s still exists with %d references",
714 td
->dm_dev
.name
, atomic_read(&td
->count
));
720 * Get the geometry associated with a dm device
722 int dm_get_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
730 * Set the geometry of a device.
732 int dm_set_geometry(struct mapped_device
*md
, struct hd_geometry
*geo
)
734 sector_t sz
= (sector_t
)geo
->cylinders
* geo
->heads
* geo
->sectors
;
736 if (geo
->start
> sz
) {
737 DMWARN("Start sector is beyond the geometry limits.");
746 /*-----------------------------------------------------------------
748 * A more elegant soln is in the works that uses the queue
749 * merge fn, unfortunately there are a couple of changes to
750 * the block layer that I want to make for this. So in the
751 * interests of getting something for people to use I give
752 * you this clearly demarcated crap.
753 *---------------------------------------------------------------*/
755 static int __noflush_suspending(struct mapped_device
*md
)
757 return test_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
761 * Decrements the number of outstanding ios that a bio has been
762 * cloned into, completing the original io if necc.
764 static void dec_pending(struct dm_io
*io
, int error
)
769 struct mapped_device
*md
= io
->md
;
771 /* Push-back supersedes any I/O errors */
772 if (unlikely(error
)) {
773 spin_lock_irqsave(&io
->endio_lock
, flags
);
774 if (!(io
->error
> 0 && __noflush_suspending(md
)))
776 spin_unlock_irqrestore(&io
->endio_lock
, flags
);
779 if (atomic_dec_and_test(&io
->io_count
)) {
780 if (io
->error
== DM_ENDIO_REQUEUE
) {
782 * Target requested pushing back the I/O.
784 spin_lock_irqsave(&md
->deferred_lock
, flags
);
785 if (__noflush_suspending(md
))
786 bio_list_add_head(&md
->deferred
, io
->bio
);
788 /* noflush suspend was interrupted. */
790 spin_unlock_irqrestore(&md
->deferred_lock
, flags
);
793 io_error
= io
->error
;
798 if (io_error
== DM_ENDIO_REQUEUE
)
801 if ((bio
->bi_rw
& REQ_PREFLUSH
) && bio
->bi_iter
.bi_size
) {
803 * Preflush done for flush with data, reissue
804 * without REQ_PREFLUSH.
806 bio
->bi_rw
&= ~REQ_PREFLUSH
;
809 /* done with normal IO or empty flush */
810 trace_block_bio_complete(md
->queue
, bio
, io_error
);
811 bio
->bi_error
= io_error
;
817 void disable_write_same(struct mapped_device
*md
)
819 struct queue_limits
*limits
= dm_get_queue_limits(md
);
821 /* device doesn't really support WRITE SAME, disable it */
822 limits
->max_write_same_sectors
= 0;
825 static void clone_endio(struct bio
*bio
)
827 int error
= bio
->bi_error
;
829 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
830 struct dm_io
*io
= tio
->io
;
831 struct mapped_device
*md
= tio
->io
->md
;
832 dm_endio_fn endio
= tio
->ti
->type
->end_io
;
835 r
= endio(tio
->ti
, bio
, error
);
836 if (r
< 0 || r
== DM_ENDIO_REQUEUE
)
838 * error and requeue request are handled
842 else if (r
== DM_ENDIO_INCOMPLETE
)
843 /* The target will handle the io */
846 DMWARN("unimplemented target endio return value: %d", r
);
851 if (unlikely(r
== -EREMOTEIO
&& (bio_op(bio
) == REQ_OP_WRITE_SAME
) &&
852 !bdev_get_queue(bio
->bi_bdev
)->limits
.max_write_same_sectors
))
853 disable_write_same(md
);
856 dec_pending(io
, error
);
860 * Return maximum size of I/O possible at the supplied sector up to the current
863 static sector_t
max_io_len_target_boundary(sector_t sector
, struct dm_target
*ti
)
865 sector_t target_offset
= dm_target_offset(ti
, sector
);
867 return ti
->len
- target_offset
;
870 static sector_t
max_io_len(sector_t sector
, struct dm_target
*ti
)
872 sector_t len
= max_io_len_target_boundary(sector
, ti
);
873 sector_t offset
, max_len
;
876 * Does the target need to split even further?
878 if (ti
->max_io_len
) {
879 offset
= dm_target_offset(ti
, sector
);
880 if (unlikely(ti
->max_io_len
& (ti
->max_io_len
- 1)))
881 max_len
= sector_div(offset
, ti
->max_io_len
);
883 max_len
= offset
& (ti
->max_io_len
- 1);
884 max_len
= ti
->max_io_len
- max_len
;
893 int dm_set_target_max_io_len(struct dm_target
*ti
, sector_t len
)
895 if (len
> UINT_MAX
) {
896 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
897 (unsigned long long)len
, UINT_MAX
);
898 ti
->error
= "Maximum size of target IO is too large";
902 ti
->max_io_len
= (uint32_t) len
;
906 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len
);
908 static long dm_blk_direct_access(struct block_device
*bdev
, sector_t sector
,
909 void **kaddr
, pfn_t
*pfn
, long size
)
911 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
912 struct dm_table
*map
;
913 struct dm_target
*ti
;
915 long len
, ret
= -EIO
;
917 map
= dm_get_live_table(md
, &srcu_idx
);
921 ti
= dm_table_find_target(map
, sector
);
922 if (!dm_target_is_valid(ti
))
925 len
= max_io_len(sector
, ti
) << SECTOR_SHIFT
;
926 size
= min(len
, size
);
928 if (ti
->type
->direct_access
)
929 ret
= ti
->type
->direct_access(ti
, sector
, kaddr
, pfn
, size
);
931 dm_put_live_table(md
, srcu_idx
);
932 return min(ret
, size
);
936 * A target may call dm_accept_partial_bio only from the map routine. It is
937 * allowed for all bio types except REQ_PREFLUSH.
939 * dm_accept_partial_bio informs the dm that the target only wants to process
940 * additional n_sectors sectors of the bio and the rest of the data should be
941 * sent in a next bio.
943 * A diagram that explains the arithmetics:
944 * +--------------------+---------------+-------+
946 * +--------------------+---------------+-------+
948 * <-------------- *tio->len_ptr --------------->
949 * <------- bi_size ------->
952 * Region 1 was already iterated over with bio_advance or similar function.
953 * (it may be empty if the target doesn't use bio_advance)
954 * Region 2 is the remaining bio size that the target wants to process.
955 * (it may be empty if region 1 is non-empty, although there is no reason
957 * The target requires that region 3 is to be sent in the next bio.
959 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
960 * the partially processed part (the sum of regions 1+2) must be the same for all
963 void dm_accept_partial_bio(struct bio
*bio
, unsigned n_sectors
)
965 struct dm_target_io
*tio
= container_of(bio
, struct dm_target_io
, clone
);
966 unsigned bi_size
= bio
->bi_iter
.bi_size
>> SECTOR_SHIFT
;
967 BUG_ON(bio
->bi_rw
& REQ_PREFLUSH
);
968 BUG_ON(bi_size
> *tio
->len_ptr
);
969 BUG_ON(n_sectors
> bi_size
);
970 *tio
->len_ptr
-= bi_size
- n_sectors
;
971 bio
->bi_iter
.bi_size
= n_sectors
<< SECTOR_SHIFT
;
973 EXPORT_SYMBOL_GPL(dm_accept_partial_bio
);
975 static void __map_bio(struct dm_target_io
*tio
)
979 struct bio
*clone
= &tio
->clone
;
980 struct dm_target
*ti
= tio
->ti
;
982 clone
->bi_end_io
= clone_endio
;
985 * Map the clone. If r == 0 we don't need to do
986 * anything, the target has assumed ownership of
989 atomic_inc(&tio
->io
->io_count
);
990 sector
= clone
->bi_iter
.bi_sector
;
991 r
= ti
->type
->map(ti
, clone
);
992 if (r
== DM_MAPIO_REMAPPED
) {
993 /* the bio has been remapped so dispatch it */
995 trace_block_bio_remap(bdev_get_queue(clone
->bi_bdev
), clone
,
996 tio
->io
->bio
->bi_bdev
->bd_dev
, sector
);
998 generic_make_request(clone
);
999 } else if (r
< 0 || r
== DM_MAPIO_REQUEUE
) {
1000 /* error the io and bail out, or requeue it if needed */
1001 dec_pending(tio
->io
, r
);
1003 } else if (r
!= DM_MAPIO_SUBMITTED
) {
1004 DMWARN("unimplemented target map return value: %d", r
);
1010 struct mapped_device
*md
;
1011 struct dm_table
*map
;
1015 unsigned sector_count
;
1018 static void bio_setup_sector(struct bio
*bio
, sector_t sector
, unsigned len
)
1020 bio
->bi_iter
.bi_sector
= sector
;
1021 bio
->bi_iter
.bi_size
= to_bytes(len
);
1025 * Creates a bio that consists of range of complete bvecs.
1027 static int clone_bio(struct dm_target_io
*tio
, struct bio
*bio
,
1028 sector_t sector
, unsigned len
)
1030 struct bio
*clone
= &tio
->clone
;
1032 __bio_clone_fast(clone
, bio
);
1034 if (bio_integrity(bio
)) {
1035 int r
= bio_integrity_clone(clone
, bio
, GFP_NOIO
);
1040 bio_advance(clone
, to_bytes(sector
- clone
->bi_iter
.bi_sector
));
1041 clone
->bi_iter
.bi_size
= to_bytes(len
);
1043 if (bio_integrity(bio
))
1044 bio_integrity_trim(clone
, 0, len
);
1049 static struct dm_target_io
*alloc_tio(struct clone_info
*ci
,
1050 struct dm_target
*ti
,
1051 unsigned target_bio_nr
)
1053 struct dm_target_io
*tio
;
1056 clone
= bio_alloc_bioset(GFP_NOIO
, 0, ci
->md
->bs
);
1057 tio
= container_of(clone
, struct dm_target_io
, clone
);
1061 tio
->target_bio_nr
= target_bio_nr
;
1066 static void __clone_and_map_simple_bio(struct clone_info
*ci
,
1067 struct dm_target
*ti
,
1068 unsigned target_bio_nr
, unsigned *len
)
1070 struct dm_target_io
*tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1071 struct bio
*clone
= &tio
->clone
;
1075 __bio_clone_fast(clone
, ci
->bio
);
1077 bio_setup_sector(clone
, ci
->sector
, *len
);
1082 static void __send_duplicate_bios(struct clone_info
*ci
, struct dm_target
*ti
,
1083 unsigned num_bios
, unsigned *len
)
1085 unsigned target_bio_nr
;
1087 for (target_bio_nr
= 0; target_bio_nr
< num_bios
; target_bio_nr
++)
1088 __clone_and_map_simple_bio(ci
, ti
, target_bio_nr
, len
);
1091 static int __send_empty_flush(struct clone_info
*ci
)
1093 unsigned target_nr
= 0;
1094 struct dm_target
*ti
;
1096 BUG_ON(bio_has_data(ci
->bio
));
1097 while ((ti
= dm_table_get_target(ci
->map
, target_nr
++)))
1098 __send_duplicate_bios(ci
, ti
, ti
->num_flush_bios
, NULL
);
1103 static int __clone_and_map_data_bio(struct clone_info
*ci
, struct dm_target
*ti
,
1104 sector_t sector
, unsigned *len
)
1106 struct bio
*bio
= ci
->bio
;
1107 struct dm_target_io
*tio
;
1108 unsigned target_bio_nr
;
1109 unsigned num_target_bios
= 1;
1113 * Does the target want to receive duplicate copies of the bio?
1115 if (bio_data_dir(bio
) == WRITE
&& ti
->num_write_bios
)
1116 num_target_bios
= ti
->num_write_bios(ti
, bio
);
1118 for (target_bio_nr
= 0; target_bio_nr
< num_target_bios
; target_bio_nr
++) {
1119 tio
= alloc_tio(ci
, ti
, target_bio_nr
);
1121 r
= clone_bio(tio
, bio
, sector
, *len
);
1132 typedef unsigned (*get_num_bios_fn
)(struct dm_target
*ti
);
1134 static unsigned get_num_discard_bios(struct dm_target
*ti
)
1136 return ti
->num_discard_bios
;
1139 static unsigned get_num_write_same_bios(struct dm_target
*ti
)
1141 return ti
->num_write_same_bios
;
1144 typedef bool (*is_split_required_fn
)(struct dm_target
*ti
);
1146 static bool is_split_required_for_discard(struct dm_target
*ti
)
1148 return ti
->split_discard_bios
;
1151 static int __send_changing_extent_only(struct clone_info
*ci
,
1152 get_num_bios_fn get_num_bios
,
1153 is_split_required_fn is_split_required
)
1155 struct dm_target
*ti
;
1160 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1161 if (!dm_target_is_valid(ti
))
1165 * Even though the device advertised support for this type of
1166 * request, that does not mean every target supports it, and
1167 * reconfiguration might also have changed that since the
1168 * check was performed.
1170 num_bios
= get_num_bios
? get_num_bios(ti
) : 0;
1174 if (is_split_required
&& !is_split_required(ti
))
1175 len
= min((sector_t
)ci
->sector_count
, max_io_len_target_boundary(ci
->sector
, ti
));
1177 len
= min((sector_t
)ci
->sector_count
, max_io_len(ci
->sector
, ti
));
1179 __send_duplicate_bios(ci
, ti
, num_bios
, &len
);
1182 } while (ci
->sector_count
-= len
);
1187 static int __send_discard(struct clone_info
*ci
)
1189 return __send_changing_extent_only(ci
, get_num_discard_bios
,
1190 is_split_required_for_discard
);
1193 static int __send_write_same(struct clone_info
*ci
)
1195 return __send_changing_extent_only(ci
, get_num_write_same_bios
, NULL
);
1199 * Select the correct strategy for processing a non-flush bio.
1201 static int __split_and_process_non_flush(struct clone_info
*ci
)
1203 struct bio
*bio
= ci
->bio
;
1204 struct dm_target
*ti
;
1208 if (unlikely(bio_op(bio
) == REQ_OP_DISCARD
))
1209 return __send_discard(ci
);
1210 else if (unlikely(bio_op(bio
) == REQ_OP_WRITE_SAME
))
1211 return __send_write_same(ci
);
1213 ti
= dm_table_find_target(ci
->map
, ci
->sector
);
1214 if (!dm_target_is_valid(ti
))
1217 len
= min_t(sector_t
, max_io_len(ci
->sector
, ti
), ci
->sector_count
);
1219 r
= __clone_and_map_data_bio(ci
, ti
, ci
->sector
, &len
);
1224 ci
->sector_count
-= len
;
1230 * Entry point to split a bio into clones and submit them to the targets.
1232 static void __split_and_process_bio(struct mapped_device
*md
,
1233 struct dm_table
*map
, struct bio
*bio
)
1235 struct clone_info ci
;
1238 if (unlikely(!map
)) {
1245 ci
.io
= alloc_io(md
);
1247 atomic_set(&ci
.io
->io_count
, 1);
1250 spin_lock_init(&ci
.io
->endio_lock
);
1251 ci
.sector
= bio
->bi_iter
.bi_sector
;
1253 start_io_acct(ci
.io
);
1255 if (bio
->bi_rw
& REQ_PREFLUSH
) {
1256 ci
.bio
= &ci
.md
->flush_bio
;
1257 ci
.sector_count
= 0;
1258 error
= __send_empty_flush(&ci
);
1259 /* dec_pending submits any data associated with flush */
1262 ci
.sector_count
= bio_sectors(bio
);
1263 while (ci
.sector_count
&& !error
)
1264 error
= __split_and_process_non_flush(&ci
);
1267 /* drop the extra reference count */
1268 dec_pending(ci
.io
, error
);
1270 /*-----------------------------------------------------------------
1272 *---------------------------------------------------------------*/
1275 * The request function that just remaps the bio built up by
1278 static blk_qc_t
dm_make_request(struct request_queue
*q
, struct bio
*bio
)
1280 int rw
= bio_data_dir(bio
);
1281 struct mapped_device
*md
= q
->queuedata
;
1283 struct dm_table
*map
;
1285 map
= dm_get_live_table(md
, &srcu_idx
);
1287 generic_start_io_acct(rw
, bio_sectors(bio
), &dm_disk(md
)->part0
);
1289 /* if we're suspended, we have to queue this io for later */
1290 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
))) {
1291 dm_put_live_table(md
, srcu_idx
);
1293 if (!(bio
->bi_rw
& REQ_RAHEAD
))
1297 return BLK_QC_T_NONE
;
1300 __split_and_process_bio(md
, map
, bio
);
1301 dm_put_live_table(md
, srcu_idx
);
1302 return BLK_QC_T_NONE
;
1305 static int dm_any_congested(void *congested_data
, int bdi_bits
)
1308 struct mapped_device
*md
= congested_data
;
1309 struct dm_table
*map
;
1311 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
1312 if (dm_request_based(md
)) {
1314 * With request-based DM we only need to check the
1315 * top-level queue for congestion.
1317 r
= md
->queue
->backing_dev_info
.wb
.state
& bdi_bits
;
1319 map
= dm_get_live_table_fast(md
);
1321 r
= dm_table_any_congested(map
, bdi_bits
);
1322 dm_put_live_table_fast(md
);
1329 /*-----------------------------------------------------------------
1330 * An IDR is used to keep track of allocated minor numbers.
1331 *---------------------------------------------------------------*/
1332 static void free_minor(int minor
)
1334 spin_lock(&_minor_lock
);
1335 idr_remove(&_minor_idr
, minor
);
1336 spin_unlock(&_minor_lock
);
1340 * See if the device with a specific minor # is free.
1342 static int specific_minor(int minor
)
1346 if (minor
>= (1 << MINORBITS
))
1349 idr_preload(GFP_KERNEL
);
1350 spin_lock(&_minor_lock
);
1352 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, minor
, minor
+ 1, GFP_NOWAIT
);
1354 spin_unlock(&_minor_lock
);
1357 return r
== -ENOSPC
? -EBUSY
: r
;
1361 static int next_free_minor(int *minor
)
1365 idr_preload(GFP_KERNEL
);
1366 spin_lock(&_minor_lock
);
1368 r
= idr_alloc(&_minor_idr
, MINOR_ALLOCED
, 0, 1 << MINORBITS
, GFP_NOWAIT
);
1370 spin_unlock(&_minor_lock
);
1378 static const struct block_device_operations dm_blk_dops
;
1380 static void dm_wq_work(struct work_struct
*work
);
1382 void dm_init_md_queue(struct mapped_device
*md
)
1385 * Request-based dm devices cannot be stacked on top of bio-based dm
1386 * devices. The type of this dm device may not have been decided yet.
1387 * The type is decided at the first table loading time.
1388 * To prevent problematic device stacking, clear the queue flag
1389 * for request stacking support until then.
1391 * This queue is new, so no concurrency on the queue_flags.
1393 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE
, md
->queue
);
1396 * Initialize data that will only be used by a non-blk-mq DM queue
1397 * - must do so here (in alloc_dev callchain) before queue is used
1399 md
->queue
->queuedata
= md
;
1400 md
->queue
->backing_dev_info
.congested_data
= md
;
1403 void dm_init_normal_md_queue(struct mapped_device
*md
)
1405 md
->use_blk_mq
= false;
1406 dm_init_md_queue(md
);
1409 * Initialize aspects of queue that aren't relevant for blk-mq
1411 md
->queue
->backing_dev_info
.congested_fn
= dm_any_congested
;
1412 blk_queue_bounce_limit(md
->queue
, BLK_BOUNCE_ANY
);
1415 static void cleanup_mapped_device(struct mapped_device
*md
)
1418 destroy_workqueue(md
->wq
);
1419 if (md
->kworker_task
)
1420 kthread_stop(md
->kworker_task
);
1421 mempool_destroy(md
->io_pool
);
1422 mempool_destroy(md
->rq_pool
);
1424 bioset_free(md
->bs
);
1426 cleanup_srcu_struct(&md
->io_barrier
);
1429 spin_lock(&_minor_lock
);
1430 md
->disk
->private_data
= NULL
;
1431 spin_unlock(&_minor_lock
);
1432 del_gendisk(md
->disk
);
1437 blk_cleanup_queue(md
->queue
);
1444 dm_mq_cleanup_mapped_device(md
);
1448 * Allocate and initialise a blank device with a given minor.
1450 static struct mapped_device
*alloc_dev(int minor
)
1452 int r
, numa_node_id
= dm_get_numa_node();
1453 struct mapped_device
*md
;
1456 md
= kzalloc_node(sizeof(*md
), GFP_KERNEL
, numa_node_id
);
1458 DMWARN("unable to allocate device, out of memory.");
1462 if (!try_module_get(THIS_MODULE
))
1463 goto bad_module_get
;
1465 /* get a minor number for the dev */
1466 if (minor
== DM_ANY_MINOR
)
1467 r
= next_free_minor(&minor
);
1469 r
= specific_minor(minor
);
1473 r
= init_srcu_struct(&md
->io_barrier
);
1475 goto bad_io_barrier
;
1477 md
->numa_node_id
= numa_node_id
;
1478 md
->use_blk_mq
= dm_use_blk_mq_default();
1479 md
->init_tio_pdu
= false;
1480 md
->type
= DM_TYPE_NONE
;
1481 mutex_init(&md
->suspend_lock
);
1482 mutex_init(&md
->type_lock
);
1483 mutex_init(&md
->table_devices_lock
);
1484 spin_lock_init(&md
->deferred_lock
);
1485 atomic_set(&md
->holders
, 1);
1486 atomic_set(&md
->open_count
, 0);
1487 atomic_set(&md
->event_nr
, 0);
1488 atomic_set(&md
->uevent_seq
, 0);
1489 INIT_LIST_HEAD(&md
->uevent_list
);
1490 INIT_LIST_HEAD(&md
->table_devices
);
1491 spin_lock_init(&md
->uevent_lock
);
1493 md
->queue
= blk_alloc_queue_node(GFP_KERNEL
, numa_node_id
);
1497 dm_init_md_queue(md
);
1499 md
->disk
= alloc_disk_node(1, numa_node_id
);
1503 atomic_set(&md
->pending
[0], 0);
1504 atomic_set(&md
->pending
[1], 0);
1505 init_waitqueue_head(&md
->wait
);
1506 INIT_WORK(&md
->work
, dm_wq_work
);
1507 init_waitqueue_head(&md
->eventq
);
1508 init_completion(&md
->kobj_holder
.completion
);
1509 md
->kworker_task
= NULL
;
1511 md
->disk
->major
= _major
;
1512 md
->disk
->first_minor
= minor
;
1513 md
->disk
->fops
= &dm_blk_dops
;
1514 md
->disk
->queue
= md
->queue
;
1515 md
->disk
->private_data
= md
;
1516 sprintf(md
->disk
->disk_name
, "dm-%d", minor
);
1518 format_dev_t(md
->name
, MKDEV(_major
, minor
));
1520 md
->wq
= alloc_workqueue("kdmflush", WQ_MEM_RECLAIM
, 0);
1524 md
->bdev
= bdget_disk(md
->disk
, 0);
1528 bio_init(&md
->flush_bio
);
1529 md
->flush_bio
.bi_bdev
= md
->bdev
;
1530 bio_set_op_attrs(&md
->flush_bio
, REQ_OP_WRITE
, WRITE_FLUSH
);
1532 dm_stats_init(&md
->stats
);
1534 /* Populate the mapping, nobody knows we exist yet */
1535 spin_lock(&_minor_lock
);
1536 old_md
= idr_replace(&_minor_idr
, md
, minor
);
1537 spin_unlock(&_minor_lock
);
1539 BUG_ON(old_md
!= MINOR_ALLOCED
);
1544 cleanup_mapped_device(md
);
1548 module_put(THIS_MODULE
);
1554 static void unlock_fs(struct mapped_device
*md
);
1556 static void free_dev(struct mapped_device
*md
)
1558 int minor
= MINOR(disk_devt(md
->disk
));
1562 cleanup_mapped_device(md
);
1564 free_table_devices(&md
->table_devices
);
1565 dm_stats_cleanup(&md
->stats
);
1568 module_put(THIS_MODULE
);
1572 static void __bind_mempools(struct mapped_device
*md
, struct dm_table
*t
)
1574 struct dm_md_mempools
*p
= dm_table_get_md_mempools(t
);
1577 /* The md already has necessary mempools. */
1578 if (dm_table_bio_based(t
)) {
1580 * Reload bioset because front_pad may have changed
1581 * because a different table was loaded.
1583 bioset_free(md
->bs
);
1588 * There's no need to reload with request-based dm
1589 * because the size of front_pad doesn't change.
1590 * Note for future: If you are to reload bioset,
1591 * prep-ed requests in the queue may refer
1592 * to bio from the old bioset, so you must walk
1593 * through the queue to unprep.
1598 BUG_ON(!p
|| md
->io_pool
|| md
->rq_pool
|| md
->bs
);
1600 md
->io_pool
= p
->io_pool
;
1602 md
->rq_pool
= p
->rq_pool
;
1608 /* mempool bind completed, no longer need any mempools in the table */
1609 dm_table_free_md_mempools(t
);
1613 * Bind a table to the device.
1615 static void event_callback(void *context
)
1617 unsigned long flags
;
1619 struct mapped_device
*md
= (struct mapped_device
*) context
;
1621 spin_lock_irqsave(&md
->uevent_lock
, flags
);
1622 list_splice_init(&md
->uevent_list
, &uevents
);
1623 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
1625 dm_send_uevents(&uevents
, &disk_to_dev(md
->disk
)->kobj
);
1627 atomic_inc(&md
->event_nr
);
1628 wake_up(&md
->eventq
);
1632 * Protected by md->suspend_lock obtained by dm_swap_table().
1634 static void __set_size(struct mapped_device
*md
, sector_t size
)
1636 set_capacity(md
->disk
, size
);
1638 i_size_write(md
->bdev
->bd_inode
, (loff_t
)size
<< SECTOR_SHIFT
);
1642 * Returns old map, which caller must destroy.
1644 static struct dm_table
*__bind(struct mapped_device
*md
, struct dm_table
*t
,
1645 struct queue_limits
*limits
)
1647 struct dm_table
*old_map
;
1648 struct request_queue
*q
= md
->queue
;
1651 size
= dm_table_get_size(t
);
1654 * Wipe any geometry if the size of the table changed.
1656 if (size
!= dm_get_size(md
))
1657 memset(&md
->geometry
, 0, sizeof(md
->geometry
));
1659 __set_size(md
, size
);
1661 dm_table_event_callback(t
, event_callback
, md
);
1664 * The queue hasn't been stopped yet, if the old table type wasn't
1665 * for request-based during suspension. So stop it to prevent
1666 * I/O mapping before resume.
1667 * This must be done before setting the queue restrictions,
1668 * because request-based dm may be run just after the setting.
1670 if (dm_table_request_based(t
)) {
1673 * Leverage the fact that request-based DM targets are
1674 * immutable singletons and establish md->immutable_target
1675 * - used to optimize both dm_request_fn and dm_mq_queue_rq
1677 md
->immutable_target
= dm_table_get_immutable_target(t
);
1680 __bind_mempools(md
, t
);
1682 old_map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
1683 rcu_assign_pointer(md
->map
, (void *)t
);
1684 md
->immutable_target_type
= dm_table_get_immutable_target_type(t
);
1686 dm_table_set_restrictions(t
, q
, limits
);
1694 * Returns unbound table for the caller to free.
1696 static struct dm_table
*__unbind(struct mapped_device
*md
)
1698 struct dm_table
*map
= rcu_dereference_protected(md
->map
, 1);
1703 dm_table_event_callback(map
, NULL
, NULL
);
1704 RCU_INIT_POINTER(md
->map
, NULL
);
1711 * Constructor for a new device.
1713 int dm_create(int minor
, struct mapped_device
**result
)
1715 struct mapped_device
*md
;
1717 md
= alloc_dev(minor
);
1728 * Functions to manage md->type.
1729 * All are required to hold md->type_lock.
1731 void dm_lock_md_type(struct mapped_device
*md
)
1733 mutex_lock(&md
->type_lock
);
1736 void dm_unlock_md_type(struct mapped_device
*md
)
1738 mutex_unlock(&md
->type_lock
);
1741 void dm_set_md_type(struct mapped_device
*md
, unsigned type
)
1743 BUG_ON(!mutex_is_locked(&md
->type_lock
));
1747 unsigned dm_get_md_type(struct mapped_device
*md
)
1752 struct target_type
*dm_get_immutable_target_type(struct mapped_device
*md
)
1754 return md
->immutable_target_type
;
1758 * The queue_limits are only valid as long as you have a reference
1761 struct queue_limits
*dm_get_queue_limits(struct mapped_device
*md
)
1763 BUG_ON(!atomic_read(&md
->holders
));
1764 return &md
->queue
->limits
;
1766 EXPORT_SYMBOL_GPL(dm_get_queue_limits
);
1769 * Setup the DM device's queue based on md's type
1771 int dm_setup_md_queue(struct mapped_device
*md
, struct dm_table
*t
)
1774 unsigned type
= dm_get_md_type(md
);
1777 case DM_TYPE_REQUEST_BASED
:
1778 r
= dm_old_init_request_queue(md
);
1780 DMERR("Cannot initialize queue for request-based mapped device");
1784 case DM_TYPE_MQ_REQUEST_BASED
:
1785 r
= dm_mq_init_request_queue(md
, t
);
1787 DMERR("Cannot initialize queue for request-based dm-mq mapped device");
1791 case DM_TYPE_BIO_BASED
:
1792 case DM_TYPE_DAX_BIO_BASED
:
1793 dm_init_normal_md_queue(md
);
1794 blk_queue_make_request(md
->queue
, dm_make_request
);
1796 * DM handles splitting bios as needed. Free the bio_split bioset
1797 * since it won't be used (saves 1 process per bio-based DM device).
1799 bioset_free(md
->queue
->bio_split
);
1800 md
->queue
->bio_split
= NULL
;
1802 if (type
== DM_TYPE_DAX_BIO_BASED
)
1803 queue_flag_set_unlocked(QUEUE_FLAG_DAX
, md
->queue
);
1810 struct mapped_device
*dm_get_md(dev_t dev
)
1812 struct mapped_device
*md
;
1813 unsigned minor
= MINOR(dev
);
1815 if (MAJOR(dev
) != _major
|| minor
>= (1 << MINORBITS
))
1818 spin_lock(&_minor_lock
);
1820 md
= idr_find(&_minor_idr
, minor
);
1822 if ((md
== MINOR_ALLOCED
||
1823 (MINOR(disk_devt(dm_disk(md
))) != minor
) ||
1824 dm_deleting_md(md
) ||
1825 test_bit(DMF_FREEING
, &md
->flags
))) {
1833 spin_unlock(&_minor_lock
);
1837 EXPORT_SYMBOL_GPL(dm_get_md
);
1839 void *dm_get_mdptr(struct mapped_device
*md
)
1841 return md
->interface_ptr
;
1844 void dm_set_mdptr(struct mapped_device
*md
, void *ptr
)
1846 md
->interface_ptr
= ptr
;
1849 void dm_get(struct mapped_device
*md
)
1851 atomic_inc(&md
->holders
);
1852 BUG_ON(test_bit(DMF_FREEING
, &md
->flags
));
1855 int dm_hold(struct mapped_device
*md
)
1857 spin_lock(&_minor_lock
);
1858 if (test_bit(DMF_FREEING
, &md
->flags
)) {
1859 spin_unlock(&_minor_lock
);
1863 spin_unlock(&_minor_lock
);
1866 EXPORT_SYMBOL_GPL(dm_hold
);
1868 const char *dm_device_name(struct mapped_device
*md
)
1872 EXPORT_SYMBOL_GPL(dm_device_name
);
1874 static void __dm_destroy(struct mapped_device
*md
, bool wait
)
1876 struct dm_table
*map
;
1881 spin_lock(&_minor_lock
);
1882 idr_replace(&_minor_idr
, MINOR_ALLOCED
, MINOR(disk_devt(dm_disk(md
))));
1883 set_bit(DMF_FREEING
, &md
->flags
);
1884 spin_unlock(&_minor_lock
);
1886 if (dm_request_based(md
) && md
->kworker_task
)
1887 flush_kthread_worker(&md
->kworker
);
1890 * Take suspend_lock so that presuspend and postsuspend methods
1891 * do not race with internal suspend.
1893 mutex_lock(&md
->suspend_lock
);
1894 map
= dm_get_live_table(md
, &srcu_idx
);
1895 if (!dm_suspended_md(md
)) {
1896 dm_table_presuspend_targets(map
);
1897 dm_table_postsuspend_targets(map
);
1899 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
1900 dm_put_live_table(md
, srcu_idx
);
1901 mutex_unlock(&md
->suspend_lock
);
1904 * Rare, but there may be I/O requests still going to complete,
1905 * for example. Wait for all references to disappear.
1906 * No one should increment the reference count of the mapped_device,
1907 * after the mapped_device state becomes DMF_FREEING.
1910 while (atomic_read(&md
->holders
))
1912 else if (atomic_read(&md
->holders
))
1913 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
1914 dm_device_name(md
), atomic_read(&md
->holders
));
1917 dm_table_destroy(__unbind(md
));
1921 void dm_destroy(struct mapped_device
*md
)
1923 __dm_destroy(md
, true);
1926 void dm_destroy_immediate(struct mapped_device
*md
)
1928 __dm_destroy(md
, false);
1931 void dm_put(struct mapped_device
*md
)
1933 atomic_dec(&md
->holders
);
1935 EXPORT_SYMBOL_GPL(dm_put
);
1937 static int dm_wait_for_completion(struct mapped_device
*md
, int interruptible
)
1940 DECLARE_WAITQUEUE(wait
, current
);
1942 add_wait_queue(&md
->wait
, &wait
);
1945 set_current_state(interruptible
);
1947 if (!md_in_flight(md
))
1950 if (interruptible
== TASK_INTERRUPTIBLE
&&
1951 signal_pending(current
)) {
1958 set_current_state(TASK_RUNNING
);
1960 remove_wait_queue(&md
->wait
, &wait
);
1966 * Process the deferred bios
1968 static void dm_wq_work(struct work_struct
*work
)
1970 struct mapped_device
*md
= container_of(work
, struct mapped_device
,
1974 struct dm_table
*map
;
1976 map
= dm_get_live_table(md
, &srcu_idx
);
1978 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
)) {
1979 spin_lock_irq(&md
->deferred_lock
);
1980 c
= bio_list_pop(&md
->deferred
);
1981 spin_unlock_irq(&md
->deferred_lock
);
1986 if (dm_request_based(md
))
1987 generic_make_request(c
);
1989 __split_and_process_bio(md
, map
, c
);
1992 dm_put_live_table(md
, srcu_idx
);
1995 static void dm_queue_flush(struct mapped_device
*md
)
1997 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
1998 smp_mb__after_atomic();
1999 queue_work(md
->wq
, &md
->work
);
2003 * Swap in a new table, returning the old one for the caller to destroy.
2005 struct dm_table
*dm_swap_table(struct mapped_device
*md
, struct dm_table
*table
)
2007 struct dm_table
*live_map
= NULL
, *map
= ERR_PTR(-EINVAL
);
2008 struct queue_limits limits
;
2011 mutex_lock(&md
->suspend_lock
);
2013 /* device must be suspended */
2014 if (!dm_suspended_md(md
))
2018 * If the new table has no data devices, retain the existing limits.
2019 * This helps multipath with queue_if_no_path if all paths disappear,
2020 * then new I/O is queued based on these limits, and then some paths
2023 if (dm_table_has_no_data_devices(table
)) {
2024 live_map
= dm_get_live_table_fast(md
);
2026 limits
= md
->queue
->limits
;
2027 dm_put_live_table_fast(md
);
2031 r
= dm_calculate_queue_limits(table
, &limits
);
2038 map
= __bind(md
, table
, &limits
);
2041 mutex_unlock(&md
->suspend_lock
);
2046 * Functions to lock and unlock any filesystem running on the
2049 static int lock_fs(struct mapped_device
*md
)
2053 WARN_ON(md
->frozen_sb
);
2055 md
->frozen_sb
= freeze_bdev(md
->bdev
);
2056 if (IS_ERR(md
->frozen_sb
)) {
2057 r
= PTR_ERR(md
->frozen_sb
);
2058 md
->frozen_sb
= NULL
;
2062 set_bit(DMF_FROZEN
, &md
->flags
);
2067 static void unlock_fs(struct mapped_device
*md
)
2069 if (!test_bit(DMF_FROZEN
, &md
->flags
))
2072 thaw_bdev(md
->bdev
, md
->frozen_sb
);
2073 md
->frozen_sb
= NULL
;
2074 clear_bit(DMF_FROZEN
, &md
->flags
);
2078 * If __dm_suspend returns 0, the device is completely quiescent
2079 * now. There is no request-processing activity. All new requests
2080 * are being added to md->deferred list.
2082 * Caller must hold md->suspend_lock
2084 static int __dm_suspend(struct mapped_device
*md
, struct dm_table
*map
,
2085 unsigned suspend_flags
, int interruptible
)
2087 bool do_lockfs
= suspend_flags
& DM_SUSPEND_LOCKFS_FLAG
;
2088 bool noflush
= suspend_flags
& DM_SUSPEND_NOFLUSH_FLAG
;
2092 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2093 * This flag is cleared before dm_suspend returns.
2096 set_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2099 * This gets reverted if there's an error later and the targets
2100 * provide the .presuspend_undo hook.
2102 dm_table_presuspend_targets(map
);
2105 * Flush I/O to the device.
2106 * Any I/O submitted after lock_fs() may not be flushed.
2107 * noflush takes precedence over do_lockfs.
2108 * (lock_fs() flushes I/Os and waits for them to complete.)
2110 if (!noflush
&& do_lockfs
) {
2113 dm_table_presuspend_undo_targets(map
);
2119 * Here we must make sure that no processes are submitting requests
2120 * to target drivers i.e. no one may be executing
2121 * __split_and_process_bio. This is called from dm_request and
2124 * To get all processes out of __split_and_process_bio in dm_request,
2125 * we take the write lock. To prevent any process from reentering
2126 * __split_and_process_bio from dm_request and quiesce the thread
2127 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2128 * flush_workqueue(md->wq).
2130 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2132 synchronize_srcu(&md
->io_barrier
);
2135 * Stop md->queue before flushing md->wq in case request-based
2136 * dm defers requests to md->wq from md->queue.
2138 if (dm_request_based(md
)) {
2139 dm_stop_queue(md
->queue
);
2140 if (md
->kworker_task
)
2141 flush_kthread_worker(&md
->kworker
);
2144 flush_workqueue(md
->wq
);
2147 * At this point no more requests are entering target request routines.
2148 * We call dm_wait_for_completion to wait for all existing requests
2151 r
= dm_wait_for_completion(md
, interruptible
);
2154 clear_bit(DMF_NOFLUSH_SUSPENDING
, &md
->flags
);
2156 synchronize_srcu(&md
->io_barrier
);
2158 /* were we interrupted ? */
2162 if (dm_request_based(md
))
2163 dm_start_queue(md
->queue
);
2166 dm_table_presuspend_undo_targets(map
);
2167 /* pushback list is already flushed, so skip flush */
2174 * We need to be able to change a mapping table under a mounted
2175 * filesystem. For example we might want to move some data in
2176 * the background. Before the table can be swapped with
2177 * dm_bind_table, dm_suspend must be called to flush any in
2178 * flight bios and ensure that any further io gets deferred.
2181 * Suspend mechanism in request-based dm.
2183 * 1. Flush all I/Os by lock_fs() if needed.
2184 * 2. Stop dispatching any I/O by stopping the request_queue.
2185 * 3. Wait for all in-flight I/Os to be completed or requeued.
2187 * To abort suspend, start the request_queue.
2189 int dm_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
2191 struct dm_table
*map
= NULL
;
2195 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
2197 if (dm_suspended_md(md
)) {
2202 if (dm_suspended_internally_md(md
)) {
2203 /* already internally suspended, wait for internal resume */
2204 mutex_unlock(&md
->suspend_lock
);
2205 r
= wait_on_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
, TASK_INTERRUPTIBLE
);
2211 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
2213 r
= __dm_suspend(md
, map
, suspend_flags
, TASK_INTERRUPTIBLE
);
2217 set_bit(DMF_SUSPENDED
, &md
->flags
);
2219 dm_table_postsuspend_targets(map
);
2222 mutex_unlock(&md
->suspend_lock
);
2226 static int __dm_resume(struct mapped_device
*md
, struct dm_table
*map
)
2229 int r
= dm_table_resume_targets(map
);
2237 * Flushing deferred I/Os must be done after targets are resumed
2238 * so that mapping of targets can work correctly.
2239 * Request-based dm is queueing the deferred I/Os in its request_queue.
2241 if (dm_request_based(md
))
2242 dm_start_queue(md
->queue
);
2249 int dm_resume(struct mapped_device
*md
)
2252 struct dm_table
*map
= NULL
;
2255 mutex_lock_nested(&md
->suspend_lock
, SINGLE_DEPTH_NESTING
);
2257 if (!dm_suspended_md(md
))
2260 if (dm_suspended_internally_md(md
)) {
2261 /* already internally suspended, wait for internal resume */
2262 mutex_unlock(&md
->suspend_lock
);
2263 r
= wait_on_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
, TASK_INTERRUPTIBLE
);
2269 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
2270 if (!map
|| !dm_table_get_size(map
))
2273 r
= __dm_resume(md
, map
);
2277 clear_bit(DMF_SUSPENDED
, &md
->flags
);
2281 mutex_unlock(&md
->suspend_lock
);
2287 * Internal suspend/resume works like userspace-driven suspend. It waits
2288 * until all bios finish and prevents issuing new bios to the target drivers.
2289 * It may be used only from the kernel.
2292 static void __dm_internal_suspend(struct mapped_device
*md
, unsigned suspend_flags
)
2294 struct dm_table
*map
= NULL
;
2296 if (md
->internal_suspend_count
++)
2297 return; /* nested internal suspend */
2299 if (dm_suspended_md(md
)) {
2300 set_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
2301 return; /* nest suspend */
2304 map
= rcu_dereference_protected(md
->map
, lockdep_is_held(&md
->suspend_lock
));
2307 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
2308 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
2309 * would require changing .presuspend to return an error -- avoid this
2310 * until there is a need for more elaborate variants of internal suspend.
2312 (void) __dm_suspend(md
, map
, suspend_flags
, TASK_UNINTERRUPTIBLE
);
2314 set_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
2316 dm_table_postsuspend_targets(map
);
2319 static void __dm_internal_resume(struct mapped_device
*md
)
2321 BUG_ON(!md
->internal_suspend_count
);
2323 if (--md
->internal_suspend_count
)
2324 return; /* resume from nested internal suspend */
2326 if (dm_suspended_md(md
))
2327 goto done
; /* resume from nested suspend */
2330 * NOTE: existing callers don't need to call dm_table_resume_targets
2331 * (which may fail -- so best to avoid it for now by passing NULL map)
2333 (void) __dm_resume(md
, NULL
);
2336 clear_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
2337 smp_mb__after_atomic();
2338 wake_up_bit(&md
->flags
, DMF_SUSPENDED_INTERNALLY
);
2341 void dm_internal_suspend_noflush(struct mapped_device
*md
)
2343 mutex_lock(&md
->suspend_lock
);
2344 __dm_internal_suspend(md
, DM_SUSPEND_NOFLUSH_FLAG
);
2345 mutex_unlock(&md
->suspend_lock
);
2347 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush
);
2349 void dm_internal_resume(struct mapped_device
*md
)
2351 mutex_lock(&md
->suspend_lock
);
2352 __dm_internal_resume(md
);
2353 mutex_unlock(&md
->suspend_lock
);
2355 EXPORT_SYMBOL_GPL(dm_internal_resume
);
2358 * Fast variants of internal suspend/resume hold md->suspend_lock,
2359 * which prevents interaction with userspace-driven suspend.
2362 void dm_internal_suspend_fast(struct mapped_device
*md
)
2364 mutex_lock(&md
->suspend_lock
);
2365 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
2368 set_bit(DMF_BLOCK_IO_FOR_SUSPEND
, &md
->flags
);
2369 synchronize_srcu(&md
->io_barrier
);
2370 flush_workqueue(md
->wq
);
2371 dm_wait_for_completion(md
, TASK_UNINTERRUPTIBLE
);
2373 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast
);
2375 void dm_internal_resume_fast(struct mapped_device
*md
)
2377 if (dm_suspended_md(md
) || dm_suspended_internally_md(md
))
2383 mutex_unlock(&md
->suspend_lock
);
2385 EXPORT_SYMBOL_GPL(dm_internal_resume_fast
);
2387 /*-----------------------------------------------------------------
2388 * Event notification.
2389 *---------------------------------------------------------------*/
2390 int dm_kobject_uevent(struct mapped_device
*md
, enum kobject_action action
,
2393 char udev_cookie
[DM_COOKIE_LENGTH
];
2394 char *envp
[] = { udev_cookie
, NULL
};
2397 return kobject_uevent(&disk_to_dev(md
->disk
)->kobj
, action
);
2399 snprintf(udev_cookie
, DM_COOKIE_LENGTH
, "%s=%u",
2400 DM_COOKIE_ENV_VAR_NAME
, cookie
);
2401 return kobject_uevent_env(&disk_to_dev(md
->disk
)->kobj
,
2406 uint32_t dm_next_uevent_seq(struct mapped_device
*md
)
2408 return atomic_add_return(1, &md
->uevent_seq
);
2411 uint32_t dm_get_event_nr(struct mapped_device
*md
)
2413 return atomic_read(&md
->event_nr
);
2416 int dm_wait_event(struct mapped_device
*md
, int event_nr
)
2418 return wait_event_interruptible(md
->eventq
,
2419 (event_nr
!= atomic_read(&md
->event_nr
)));
2422 void dm_uevent_add(struct mapped_device
*md
, struct list_head
*elist
)
2424 unsigned long flags
;
2426 spin_lock_irqsave(&md
->uevent_lock
, flags
);
2427 list_add(elist
, &md
->uevent_list
);
2428 spin_unlock_irqrestore(&md
->uevent_lock
, flags
);
2432 * The gendisk is only valid as long as you have a reference
2435 struct gendisk
*dm_disk(struct mapped_device
*md
)
2439 EXPORT_SYMBOL_GPL(dm_disk
);
2441 struct kobject
*dm_kobject(struct mapped_device
*md
)
2443 return &md
->kobj_holder
.kobj
;
2446 struct mapped_device
*dm_get_from_kobject(struct kobject
*kobj
)
2448 struct mapped_device
*md
;
2450 md
= container_of(kobj
, struct mapped_device
, kobj_holder
.kobj
);
2452 if (test_bit(DMF_FREEING
, &md
->flags
) ||
2460 int dm_suspended_md(struct mapped_device
*md
)
2462 return test_bit(DMF_SUSPENDED
, &md
->flags
);
2465 int dm_suspended_internally_md(struct mapped_device
*md
)
2467 return test_bit(DMF_SUSPENDED_INTERNALLY
, &md
->flags
);
2470 int dm_test_deferred_remove_flag(struct mapped_device
*md
)
2472 return test_bit(DMF_DEFERRED_REMOVE
, &md
->flags
);
2475 int dm_suspended(struct dm_target
*ti
)
2477 return dm_suspended_md(dm_table_get_md(ti
->table
));
2479 EXPORT_SYMBOL_GPL(dm_suspended
);
2481 int dm_noflush_suspending(struct dm_target
*ti
)
2483 return __noflush_suspending(dm_table_get_md(ti
->table
));
2485 EXPORT_SYMBOL_GPL(dm_noflush_suspending
);
2487 struct dm_md_mempools
*dm_alloc_md_mempools(struct mapped_device
*md
, unsigned type
,
2488 unsigned integrity
, unsigned per_io_data_size
)
2490 struct dm_md_mempools
*pools
= kzalloc_node(sizeof(*pools
), GFP_KERNEL
, md
->numa_node_id
);
2491 struct kmem_cache
*cachep
= NULL
;
2492 unsigned int pool_size
= 0;
2493 unsigned int front_pad
;
2499 case DM_TYPE_BIO_BASED
:
2500 case DM_TYPE_DAX_BIO_BASED
:
2502 pool_size
= dm_get_reserved_bio_based_ios();
2503 front_pad
= roundup(per_io_data_size
, __alignof__(struct dm_target_io
)) + offsetof(struct dm_target_io
, clone
);
2505 case DM_TYPE_REQUEST_BASED
:
2506 cachep
= _rq_tio_cache
;
2507 pool_size
= dm_get_reserved_rq_based_ios();
2508 pools
->rq_pool
= mempool_create_slab_pool(pool_size
, _rq_cache
);
2509 if (!pools
->rq_pool
)
2511 /* fall through to setup remaining rq-based pools */
2512 case DM_TYPE_MQ_REQUEST_BASED
:
2514 pool_size
= dm_get_reserved_rq_based_ios();
2515 front_pad
= offsetof(struct dm_rq_clone_bio_info
, clone
);
2516 /* per_io_data_size is used for blk-mq pdu at queue allocation */
2523 pools
->io_pool
= mempool_create_slab_pool(pool_size
, cachep
);
2524 if (!pools
->io_pool
)
2528 pools
->bs
= bioset_create_nobvec(pool_size
, front_pad
);
2532 if (integrity
&& bioset_integrity_create(pools
->bs
, pool_size
))
2538 dm_free_md_mempools(pools
);
2543 void dm_free_md_mempools(struct dm_md_mempools
*pools
)
2548 mempool_destroy(pools
->io_pool
);
2549 mempool_destroy(pools
->rq_pool
);
2552 bioset_free(pools
->bs
);
2564 static int dm_call_pr(struct block_device
*bdev
, iterate_devices_callout_fn fn
,
2567 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2568 struct dm_table
*table
;
2569 struct dm_target
*ti
;
2570 int ret
= -ENOTTY
, srcu_idx
;
2572 table
= dm_get_live_table(md
, &srcu_idx
);
2573 if (!table
|| !dm_table_get_size(table
))
2576 /* We only support devices that have a single target */
2577 if (dm_table_get_num_targets(table
) != 1)
2579 ti
= dm_table_get_target(table
, 0);
2582 if (!ti
->type
->iterate_devices
)
2585 ret
= ti
->type
->iterate_devices(ti
, fn
, data
);
2587 dm_put_live_table(md
, srcu_idx
);
2592 * For register / unregister we need to manually call out to every path.
2594 static int __dm_pr_register(struct dm_target
*ti
, struct dm_dev
*dev
,
2595 sector_t start
, sector_t len
, void *data
)
2597 struct dm_pr
*pr
= data
;
2598 const struct pr_ops
*ops
= dev
->bdev
->bd_disk
->fops
->pr_ops
;
2600 if (!ops
|| !ops
->pr_register
)
2602 return ops
->pr_register(dev
->bdev
, pr
->old_key
, pr
->new_key
, pr
->flags
);
2605 static int dm_pr_register(struct block_device
*bdev
, u64 old_key
, u64 new_key
,
2616 ret
= dm_call_pr(bdev
, __dm_pr_register
, &pr
);
2617 if (ret
&& new_key
) {
2618 /* unregister all paths if we failed to register any path */
2619 pr
.old_key
= new_key
;
2622 pr
.fail_early
= false;
2623 dm_call_pr(bdev
, __dm_pr_register
, &pr
);
2629 static int dm_pr_reserve(struct block_device
*bdev
, u64 key
, enum pr_type type
,
2632 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2633 const struct pr_ops
*ops
;
2637 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
2641 ops
= bdev
->bd_disk
->fops
->pr_ops
;
2642 if (ops
&& ops
->pr_reserve
)
2643 r
= ops
->pr_reserve(bdev
, key
, type
, flags
);
2651 static int dm_pr_release(struct block_device
*bdev
, u64 key
, enum pr_type type
)
2653 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2654 const struct pr_ops
*ops
;
2658 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
2662 ops
= bdev
->bd_disk
->fops
->pr_ops
;
2663 if (ops
&& ops
->pr_release
)
2664 r
= ops
->pr_release(bdev
, key
, type
);
2672 static int dm_pr_preempt(struct block_device
*bdev
, u64 old_key
, u64 new_key
,
2673 enum pr_type type
, bool abort
)
2675 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2676 const struct pr_ops
*ops
;
2680 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
2684 ops
= bdev
->bd_disk
->fops
->pr_ops
;
2685 if (ops
&& ops
->pr_preempt
)
2686 r
= ops
->pr_preempt(bdev
, old_key
, new_key
, type
, abort
);
2694 static int dm_pr_clear(struct block_device
*bdev
, u64 key
)
2696 struct mapped_device
*md
= bdev
->bd_disk
->private_data
;
2697 const struct pr_ops
*ops
;
2701 r
= dm_grab_bdev_for_ioctl(md
, &bdev
, &mode
);
2705 ops
= bdev
->bd_disk
->fops
->pr_ops
;
2706 if (ops
&& ops
->pr_clear
)
2707 r
= ops
->pr_clear(bdev
, key
);
2715 static const struct pr_ops dm_pr_ops
= {
2716 .pr_register
= dm_pr_register
,
2717 .pr_reserve
= dm_pr_reserve
,
2718 .pr_release
= dm_pr_release
,
2719 .pr_preempt
= dm_pr_preempt
,
2720 .pr_clear
= dm_pr_clear
,
2723 static const struct block_device_operations dm_blk_dops
= {
2724 .open
= dm_blk_open
,
2725 .release
= dm_blk_close
,
2726 .ioctl
= dm_blk_ioctl
,
2727 .direct_access
= dm_blk_direct_access
,
2728 .getgeo
= dm_blk_getgeo
,
2729 .pr_ops
= &dm_pr_ops
,
2730 .owner
= THIS_MODULE
2736 module_init(dm_init
);
2737 module_exit(dm_exit
);
2739 module_param(major
, uint
, 0);
2740 MODULE_PARM_DESC(major
, "The major number of the device mapper");
2742 module_param(reserved_bio_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
2743 MODULE_PARM_DESC(reserved_bio_based_ios
, "Reserved IOs in bio-based mempools");
2745 module_param(dm_numa_node
, int, S_IRUGO
| S_IWUSR
);
2746 MODULE_PARM_DESC(dm_numa_node
, "NUMA node for DM device memory allocations");
2748 MODULE_DESCRIPTION(DM_NAME
" driver");
2749 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
2750 MODULE_LICENSE("GPL");