2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This file is released under the GPL.
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/moduleparam.h>
15 #include <linux/blkpg.h>
16 #include <linux/bio.h>
17 #include <linux/mempool.h>
18 #include <linux/slab.h>
19 #include <linux/idr.h>
20 #include <linux/hdreg.h>
21 #include <linux/delay.h>
22 #include <linux/wait.h>
24 #include <trace/events/block.h>
26 #define DM_MSG_PREFIX "core"
30 * ratelimit state to be used in DMXXX_LIMIT().
32 DEFINE_RATELIMIT_STATE(dm_ratelimit_state,
33 DEFAULT_RATELIMIT_INTERVAL,
34 DEFAULT_RATELIMIT_BURST);
35 EXPORT_SYMBOL(dm_ratelimit_state);
39 * Cookies are numeric values sent with CHANGE and REMOVE
40 * uevents while resuming, removing or renaming the device.
42 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
43 #define DM_COOKIE_LENGTH 24
45 static const char *_name = DM_NAME;
47 static unsigned int major = 0;
48 static unsigned int _major = 0;
50 static DEFINE_IDR(_minor_idr);
52 static DEFINE_SPINLOCK(_minor_lock);
54 static void do_deferred_remove(struct work_struct *w);
56 static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
58 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;
75 * For request-based dm.
76 * One of these is allocated per request.
78 struct dm_rq_target_io {
79 struct mapped_device *md;
81 struct request *orig, clone;
87 * For request-based dm - the bio clones we allocate are embedded in these
90 * We allocate these with bio_alloc_bioset, using the front_pad parameter when
91 * the bioset is created - this means the bio has to come at the end of the
94 struct dm_rq_clone_bio_info {
96 struct dm_rq_target_io *tio;
100 union map_info *dm_get_rq_mapinfo(struct request *rq)
102 if (rq && rq->end_io_data)
103 return &((struct dm_rq_target_io *)rq->end_io_data)->info;
106 EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo);
108 #define MINOR_ALLOCED ((void *)-1)
111 * Bits for the md->flags field.
113 #define DMF_BLOCK_IO_FOR_SUSPEND 0
114 #define DMF_SUSPENDED 1
116 #define DMF_FREEING 3
117 #define DMF_DELETING 4
118 #define DMF_NOFLUSH_SUSPENDING 5
119 #define DMF_MERGE_IS_OPTIONAL 6
120 #define DMF_DEFERRED_REMOVE 7
121 #define DMF_SUSPENDED_INTERNALLY 8
124 * A dummy definition to make RCU happy.
125 * struct dm_table should never be dereferenced in this file.
132 * Work processed by per-device workqueue.
134 struct mapped_device {
135 struct srcu_struct io_barrier;
136 struct mutex suspend_lock;
141 * The current mapping.
142 * Use dm_get_live_table{_fast} or take suspend_lock for
145 struct dm_table __rcu *map;
147 struct list_head table_devices;
148 struct mutex table_devices_lock;
152 struct request_queue *queue;
154 /* Protect queue and type against concurrent access. */
155 struct mutex type_lock;
157 struct target_type *immutable_target_type;
159 struct gendisk *disk;
165 * A list of ios that arrived while we were suspended.
168 wait_queue_head_t wait;
169 struct work_struct work;
170 struct bio_list deferred;
171 spinlock_t deferred_lock;
174 * Processing queue (flush)
176 struct workqueue_struct *wq;
179 * io objects are allocated from here.
189 wait_queue_head_t eventq;
191 struct list_head uevent_list;
192 spinlock_t uevent_lock; /* Protect access to uevent_list */
195 * freeze/thaw support require holding onto a super block
197 struct super_block *frozen_sb;
198 struct block_device *bdev;
200 /* forced geometry settings */
201 struct hd_geometry geometry;
203 /* kobject and completion */
204 struct dm_kobject_holder kobj_holder;
206 /* zero-length flush that will be cloned and submitted to targets */
207 struct bio flush_bio;
209 /* the number of internal suspends */
210 unsigned internal_suspend_count;
212 struct dm_stats stats;
216 * For mempools pre-allocation at the table loading time.
218 struct dm_md_mempools {
223 struct table_device {
224 struct list_head list;
226 struct dm_dev dm_dev;
229 #define RESERVED_BIO_BASED_IOS 16
230 #define RESERVED_REQUEST_BASED_IOS 256
231 #define RESERVED_MAX_IOS 1024
232 static struct kmem_cache *_io_cache;
233 static struct kmem_cache *_rq_tio_cache;
236 * Bio-based DM's mempools' reserved IOs set by the user.
238 static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
241 * Request-based DM's mempools' reserved IOs set by the user.
243 static unsigned reserved_rq_based_ios = RESERVED_REQUEST_BASED_IOS;
245 static unsigned __dm_get_reserved_ios(unsigned *reserved_ios,
246 unsigned def, unsigned max)
248 unsigned ios = ACCESS_ONCE(*reserved_ios);
249 unsigned modified_ios = 0;
257 (void)cmpxchg(reserved_ios, ios, modified_ios);
264 unsigned dm_get_reserved_bio_based_ios(void)
266 return __dm_get_reserved_ios(&reserved_bio_based_ios,
267 RESERVED_BIO_BASED_IOS, RESERVED_MAX_IOS);
269 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
271 unsigned dm_get_reserved_rq_based_ios(void)
273 return __dm_get_reserved_ios(&reserved_rq_based_ios,
274 RESERVED_REQUEST_BASED_IOS, RESERVED_MAX_IOS);
276 EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios);
278 static int __init local_init(void)
282 /* allocate a slab for the dm_ios */
283 _io_cache = KMEM_CACHE(dm_io, 0);
287 _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
289 goto out_free_io_cache;
291 r = dm_uevent_init();
293 goto out_free_rq_tio_cache;
295 deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
296 if (!deferred_remove_workqueue) {
298 goto out_uevent_exit;
302 r = register_blkdev(_major, _name);
304 goto out_free_workqueue;
312 destroy_workqueue(deferred_remove_workqueue);
315 out_free_rq_tio_cache:
316 kmem_cache_destroy(_rq_tio_cache);
318 kmem_cache_destroy(_io_cache);
323 static void local_exit(void)
325 flush_scheduled_work();
326 destroy_workqueue(deferred_remove_workqueue);
328 kmem_cache_destroy(_rq_tio_cache);
329 kmem_cache_destroy(_io_cache);
330 unregister_blkdev(_major, _name);
335 DMINFO("cleaned up");
338 static int (*_inits[])(void) __initdata = {
349 static void (*_exits[])(void) = {
360 static int __init dm_init(void)
362 const int count = ARRAY_SIZE(_inits);
366 for (i = 0; i < count; i++) {
381 static void __exit dm_exit(void)
383 int i = ARRAY_SIZE(_exits);
389 * Should be empty by this point.
391 idr_destroy(&_minor_idr);
395 * Block device functions
397 int dm_deleting_md(struct mapped_device *md)
399 return test_bit(DMF_DELETING, &md->flags);
402 static int dm_blk_open(struct block_device *bdev, fmode_t mode)
404 struct mapped_device *md;
406 spin_lock(&_minor_lock);
408 md = bdev->bd_disk->private_data;
412 if (test_bit(DMF_FREEING, &md->flags) ||
413 dm_deleting_md(md)) {
419 atomic_inc(&md->open_count);
422 spin_unlock(&_minor_lock);
424 return md ? 0 : -ENXIO;
427 static void dm_blk_close(struct gendisk *disk, fmode_t mode)
429 struct mapped_device *md = disk->private_data;
431 spin_lock(&_minor_lock);
433 if (atomic_dec_and_test(&md->open_count) &&
434 (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
435 queue_work(deferred_remove_workqueue, &deferred_remove_work);
439 spin_unlock(&_minor_lock);
442 int dm_open_count(struct mapped_device *md)
444 return atomic_read(&md->open_count);
448 * Guarantees nothing is using the device before it's deleted.
450 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
454 spin_lock(&_minor_lock);
456 if (dm_open_count(md)) {
459 set_bit(DMF_DEFERRED_REMOVE, &md->flags);
460 } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
463 set_bit(DMF_DELETING, &md->flags);
465 spin_unlock(&_minor_lock);
470 int dm_cancel_deferred_remove(struct mapped_device *md)
474 spin_lock(&_minor_lock);
476 if (test_bit(DMF_DELETING, &md->flags))
479 clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
481 spin_unlock(&_minor_lock);
486 static void do_deferred_remove(struct work_struct *w)
488 dm_deferred_remove();
491 sector_t dm_get_size(struct mapped_device *md)
493 return get_capacity(md->disk);
496 struct request_queue *dm_get_md_queue(struct mapped_device *md)
501 struct dm_stats *dm_get_stats(struct mapped_device *md)
506 static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
508 struct mapped_device *md = bdev->bd_disk->private_data;
510 return dm_get_geometry(md, geo);
513 static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
514 unsigned int cmd, unsigned long arg)
516 struct mapped_device *md = bdev->bd_disk->private_data;
518 struct dm_table *map;
519 struct dm_target *tgt;
523 map = dm_get_live_table(md, &srcu_idx);
525 if (!map || !dm_table_get_size(map))
528 /* We only support devices that have a single target */
529 if (dm_table_get_num_targets(map) != 1)
532 tgt = dm_table_get_target(map, 0);
533 if (!tgt->type->ioctl)
536 if (dm_suspended_md(md)) {
541 r = tgt->type->ioctl(tgt, cmd, arg);
544 dm_put_live_table(md, srcu_idx);
546 if (r == -ENOTCONN) {
554 static struct dm_io *alloc_io(struct mapped_device *md)
556 return mempool_alloc(md->io_pool, GFP_NOIO);
559 static void free_io(struct mapped_device *md, struct dm_io *io)
561 mempool_free(io, md->io_pool);
564 static void free_tio(struct mapped_device *md, struct dm_target_io *tio)
566 bio_put(&tio->clone);
569 static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md,
572 return mempool_alloc(md->io_pool, gfp_mask);
575 static void free_rq_tio(struct dm_rq_target_io *tio)
577 mempool_free(tio, tio->md->io_pool);
580 static int md_in_flight(struct mapped_device *md)
582 return atomic_read(&md->pending[READ]) +
583 atomic_read(&md->pending[WRITE]);
586 static void start_io_acct(struct dm_io *io)
588 struct mapped_device *md = io->md;
589 struct bio *bio = io->bio;
591 int rw = bio_data_dir(bio);
593 io->start_time = jiffies;
595 cpu = part_stat_lock();
596 part_round_stats(cpu, &dm_disk(md)->part0);
598 atomic_set(&dm_disk(md)->part0.in_flight[rw],
599 atomic_inc_return(&md->pending[rw]));
601 if (unlikely(dm_stats_used(&md->stats)))
602 dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_iter.bi_sector,
603 bio_sectors(bio), false, 0, &io->stats_aux);
606 static void end_io_acct(struct dm_io *io)
608 struct mapped_device *md = io->md;
609 struct bio *bio = io->bio;
610 unsigned long duration = jiffies - io->start_time;
612 int rw = bio_data_dir(bio);
614 generic_end_io_acct(rw, &dm_disk(md)->part0, io->start_time);
616 if (unlikely(dm_stats_used(&md->stats)))
617 dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_iter.bi_sector,
618 bio_sectors(bio), true, duration, &io->stats_aux);
621 * After this is decremented the bio must not be touched if it is
624 pending = atomic_dec_return(&md->pending[rw]);
625 atomic_set(&dm_disk(md)->part0.in_flight[rw], pending);
626 pending += atomic_read(&md->pending[rw^0x1]);
628 /* nudge anyone waiting on suspend queue */
634 * Add the bio to the list of deferred io.
636 static void queue_io(struct mapped_device *md, struct bio *bio)
640 spin_lock_irqsave(&md->deferred_lock, flags);
641 bio_list_add(&md->deferred, bio);
642 spin_unlock_irqrestore(&md->deferred_lock, flags);
643 queue_work(md->wq, &md->work);
647 * Everyone (including functions in this file), should use this
648 * function to access the md->map field, and make sure they call
649 * dm_put_live_table() when finished.
651 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
653 *srcu_idx = srcu_read_lock(&md->io_barrier);
655 return srcu_dereference(md->map, &md->io_barrier);
658 void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
660 srcu_read_unlock(&md->io_barrier, srcu_idx);
663 void dm_sync_table(struct mapped_device *md)
665 synchronize_srcu(&md->io_barrier);
666 synchronize_rcu_expedited();
670 * A fast alternative to dm_get_live_table/dm_put_live_table.
671 * The caller must not block between these two functions.
673 static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
676 return rcu_dereference(md->map);
679 static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
685 * Open a table device so we can use it as a map destination.
687 static int open_table_device(struct table_device *td, dev_t dev,
688 struct mapped_device *md)
690 static char *_claim_ptr = "I belong to device-mapper";
691 struct block_device *bdev;
695 BUG_ON(td->dm_dev.bdev);
697 bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _claim_ptr);
699 return PTR_ERR(bdev);
701 r = bd_link_disk_holder(bdev, dm_disk(md));
703 blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
707 td->dm_dev.bdev = bdev;
712 * Close a table device that we've been using.
714 static void close_table_device(struct table_device *td, struct mapped_device *md)
716 if (!td->dm_dev.bdev)
719 bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
720 blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
721 td->dm_dev.bdev = NULL;
724 static struct table_device *find_table_device(struct list_head *l, dev_t dev,
726 struct table_device *td;
728 list_for_each_entry(td, l, list)
729 if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
735 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
736 struct dm_dev **result) {
738 struct table_device *td;
740 mutex_lock(&md->table_devices_lock);
741 td = find_table_device(&md->table_devices, dev, mode);
743 td = kmalloc(sizeof(*td), GFP_KERNEL);
745 mutex_unlock(&md->table_devices_lock);
749 td->dm_dev.mode = mode;
750 td->dm_dev.bdev = NULL;
752 if ((r = open_table_device(td, dev, md))) {
753 mutex_unlock(&md->table_devices_lock);
758 format_dev_t(td->dm_dev.name, dev);
760 atomic_set(&td->count, 0);
761 list_add(&td->list, &md->table_devices);
763 atomic_inc(&td->count);
764 mutex_unlock(&md->table_devices_lock);
766 *result = &td->dm_dev;
769 EXPORT_SYMBOL_GPL(dm_get_table_device);
771 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
773 struct table_device *td = container_of(d, struct table_device, dm_dev);
775 mutex_lock(&md->table_devices_lock);
776 if (atomic_dec_and_test(&td->count)) {
777 close_table_device(td, md);
781 mutex_unlock(&md->table_devices_lock);
783 EXPORT_SYMBOL(dm_put_table_device);
785 static void free_table_devices(struct list_head *devices)
787 struct list_head *tmp, *next;
789 list_for_each_safe(tmp, next, devices) {
790 struct table_device *td = list_entry(tmp, struct table_device, list);
792 DMWARN("dm_destroy: %s still exists with %d references",
793 td->dm_dev.name, atomic_read(&td->count));
799 * Get the geometry associated with a dm device
801 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
809 * Set the geometry of a device.
811 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
813 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
815 if (geo->start > sz) {
816 DMWARN("Start sector is beyond the geometry limits.");
825 /*-----------------------------------------------------------------
827 * A more elegant soln is in the works that uses the queue
828 * merge fn, unfortunately there are a couple of changes to
829 * the block layer that I want to make for this. So in the
830 * interests of getting something for people to use I give
831 * you this clearly demarcated crap.
832 *---------------------------------------------------------------*/
834 static int __noflush_suspending(struct mapped_device *md)
836 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
840 * Decrements the number of outstanding ios that a bio has been
841 * cloned into, completing the original io if necc.
843 static void dec_pending(struct dm_io *io, int error)
848 struct mapped_device *md = io->md;
850 /* Push-back supersedes any I/O errors */
851 if (unlikely(error)) {
852 spin_lock_irqsave(&io->endio_lock, flags);
853 if (!(io->error > 0 && __noflush_suspending(md)))
855 spin_unlock_irqrestore(&io->endio_lock, flags);
858 if (atomic_dec_and_test(&io->io_count)) {
859 if (io->error == DM_ENDIO_REQUEUE) {
861 * Target requested pushing back the I/O.
863 spin_lock_irqsave(&md->deferred_lock, flags);
864 if (__noflush_suspending(md))
865 bio_list_add_head(&md->deferred, io->bio);
867 /* noflush suspend was interrupted. */
869 spin_unlock_irqrestore(&md->deferred_lock, flags);
872 io_error = io->error;
877 if (io_error == DM_ENDIO_REQUEUE)
880 if ((bio->bi_rw & REQ_FLUSH) && bio->bi_iter.bi_size) {
882 * Preflush done for flush with data, reissue
885 bio->bi_rw &= ~REQ_FLUSH;
888 /* done with normal IO or empty flush */
889 trace_block_bio_complete(md->queue, bio, io_error);
890 bio_endio(bio, io_error);
895 static void disable_write_same(struct mapped_device *md)
897 struct queue_limits *limits = dm_get_queue_limits(md);
899 /* device doesn't really support WRITE SAME, disable it */
900 limits->max_write_same_sectors = 0;
903 static void clone_endio(struct bio *bio, int error)
906 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
907 struct dm_io *io = tio->io;
908 struct mapped_device *md = tio->io->md;
909 dm_endio_fn endio = tio->ti->type->end_io;
911 if (!bio_flagged(bio, BIO_UPTODATE) && !error)
915 r = endio(tio->ti, bio, error);
916 if (r < 0 || r == DM_ENDIO_REQUEUE)
918 * error and requeue request are handled
922 else if (r == DM_ENDIO_INCOMPLETE)
923 /* The target will handle the io */
926 DMWARN("unimplemented target endio return value: %d", r);
931 if (unlikely(r == -EREMOTEIO && (bio->bi_rw & REQ_WRITE_SAME) &&
932 !bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors))
933 disable_write_same(md);
936 dec_pending(io, error);
940 * Partial completion handling for request-based dm
942 static void end_clone_bio(struct bio *clone, int error)
944 struct dm_rq_clone_bio_info *info =
945 container_of(clone, struct dm_rq_clone_bio_info, clone);
946 struct dm_rq_target_io *tio = info->tio;
947 struct bio *bio = info->orig;
948 unsigned int nr_bytes = info->orig->bi_iter.bi_size;
954 * An error has already been detected on the request.
955 * Once error occurred, just let clone->end_io() handle
961 * Don't notice the error to the upper layer yet.
962 * The error handling decision is made by the target driver,
963 * when the request is completed.
970 * I/O for the bio successfully completed.
971 * Notice the data completion to the upper layer.
975 * bios are processed from the head of the list.
976 * So the completing bio should always be rq->bio.
977 * If it's not, something wrong is happening.
979 if (tio->orig->bio != bio)
980 DMERR("bio completion is going in the middle of the request");
983 * Update the original request.
984 * Do not use blk_end_request() here, because it may complete
985 * the original request before the clone, and break the ordering.
987 blk_update_request(tio->orig, 0, nr_bytes);
991 * Don't touch any member of the md after calling this function because
992 * the md may be freed in dm_put() at the end of this function.
993 * Or do dm_get() before calling this function and dm_put() later.
995 static void rq_completed(struct mapped_device *md, int rw, int run_queue)
997 atomic_dec(&md->pending[rw]);
999 /* nudge anyone waiting on suspend queue */
1000 if (!md_in_flight(md))
1004 * Run this off this callpath, as drivers could invoke end_io while
1005 * inside their request_fn (and holding the queue lock). Calling
1006 * back into ->request_fn() could deadlock attempting to grab the
1010 blk_run_queue_async(md->queue);
1013 * dm_put() must be at the end of this function. See the comment above
1018 static void free_rq_clone(struct request *clone)
1020 struct dm_rq_target_io *tio = clone->end_io_data;
1022 blk_rq_unprep_clone(clone);
1027 * Complete the clone and the original request.
1028 * Must be called without queue lock.
1030 static void dm_end_request(struct request *clone, int error)
1032 int rw = rq_data_dir(clone);
1033 struct dm_rq_target_io *tio = clone->end_io_data;
1034 struct mapped_device *md = tio->md;
1035 struct request *rq = tio->orig;
1037 if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
1038 rq->errors = clone->errors;
1039 rq->resid_len = clone->resid_len;
1043 * We are using the sense buffer of the original
1045 * So setting the length of the sense data is enough.
1047 rq->sense_len = clone->sense_len;
1050 free_rq_clone(clone);
1051 blk_end_request_all(rq, error);
1052 rq_completed(md, rw, true);
1055 static void dm_unprep_request(struct request *rq)
1057 struct request *clone = rq->special;
1060 rq->cmd_flags &= ~REQ_DONTPREP;
1062 free_rq_clone(clone);
1066 * Requeue the original request of a clone.
1068 void dm_requeue_unmapped_request(struct request *clone)
1070 int rw = rq_data_dir(clone);
1071 struct dm_rq_target_io *tio = clone->end_io_data;
1072 struct mapped_device *md = tio->md;
1073 struct request *rq = tio->orig;
1074 struct request_queue *q = rq->q;
1075 unsigned long flags;
1077 dm_unprep_request(rq);
1079 spin_lock_irqsave(q->queue_lock, flags);
1080 blk_requeue_request(q, rq);
1081 spin_unlock_irqrestore(q->queue_lock, flags);
1083 rq_completed(md, rw, 0);
1085 EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request);
1087 static void __stop_queue(struct request_queue *q)
1092 static void stop_queue(struct request_queue *q)
1094 unsigned long flags;
1096 spin_lock_irqsave(q->queue_lock, flags);
1098 spin_unlock_irqrestore(q->queue_lock, flags);
1101 static void __start_queue(struct request_queue *q)
1103 if (blk_queue_stopped(q))
1107 static void start_queue(struct request_queue *q)
1109 unsigned long flags;
1111 spin_lock_irqsave(q->queue_lock, flags);
1113 spin_unlock_irqrestore(q->queue_lock, flags);
1116 static void dm_done(struct request *clone, int error, bool mapped)
1119 struct dm_rq_target_io *tio = clone->end_io_data;
1120 dm_request_endio_fn rq_end_io = NULL;
1123 rq_end_io = tio->ti->type->rq_end_io;
1125 if (mapped && rq_end_io)
1126 r = rq_end_io(tio->ti, clone, error, &tio->info);
1129 if (unlikely(r == -EREMOTEIO && (clone->cmd_flags & REQ_WRITE_SAME) &&
1130 !clone->q->limits.max_write_same_sectors))
1131 disable_write_same(tio->md);
1134 /* The target wants to complete the I/O */
1135 dm_end_request(clone, r);
1136 else if (r == DM_ENDIO_INCOMPLETE)
1137 /* The target will handle the I/O */
1139 else if (r == DM_ENDIO_REQUEUE)
1140 /* The target wants to requeue the I/O */
1141 dm_requeue_unmapped_request(clone);
1143 DMWARN("unimplemented target endio return value: %d", r);
1149 * Request completion handler for request-based dm
1151 static void dm_softirq_done(struct request *rq)
1154 struct request *clone = rq->completion_data;
1155 struct dm_rq_target_io *tio = clone->end_io_data;
1157 if (rq->cmd_flags & REQ_FAILED)
1160 dm_done(clone, tio->error, mapped);
1164 * Complete the clone and the original request with the error status
1165 * through softirq context.
1167 static void dm_complete_request(struct request *clone, int error)
1169 struct dm_rq_target_io *tio = clone->end_io_data;
1170 struct request *rq = tio->orig;
1173 rq->completion_data = clone;
1174 blk_complete_request(rq);
1178 * Complete the not-mapped clone and the original request with the error status
1179 * through softirq context.
1180 * Target's rq_end_io() function isn't called.
1181 * This may be used when the target's map_rq() function fails.
1183 void dm_kill_unmapped_request(struct request *clone, int error)
1185 struct dm_rq_target_io *tio = clone->end_io_data;
1186 struct request *rq = tio->orig;
1188 rq->cmd_flags |= REQ_FAILED;
1189 dm_complete_request(clone, error);
1191 EXPORT_SYMBOL_GPL(dm_kill_unmapped_request);
1194 * Called with the queue lock held
1196 static void end_clone_request(struct request *clone, int error)
1199 * For just cleaning up the information of the queue in which
1200 * the clone was dispatched.
1201 * The clone is *NOT* freed actually here because it is alloced from
1202 * dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags.
1204 __blk_put_request(clone->q, clone);
1207 * Actual request completion is done in a softirq context which doesn't
1208 * hold the queue lock. Otherwise, deadlock could occur because:
1209 * - another request may be submitted by the upper level driver
1210 * of the stacking during the completion
1211 * - the submission which requires queue lock may be done
1212 * against this queue
1214 dm_complete_request(clone, error);
1218 * Return maximum size of I/O possible at the supplied sector up to the current
1221 static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
1223 sector_t target_offset = dm_target_offset(ti, sector);
1225 return ti->len - target_offset;
1228 static sector_t max_io_len(sector_t sector, struct dm_target *ti)
1230 sector_t len = max_io_len_target_boundary(sector, ti);
1231 sector_t offset, max_len;
1234 * Does the target need to split even further?
1236 if (ti->max_io_len) {
1237 offset = dm_target_offset(ti, sector);
1238 if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
1239 max_len = sector_div(offset, ti->max_io_len);
1241 max_len = offset & (ti->max_io_len - 1);
1242 max_len = ti->max_io_len - max_len;
1251 int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
1253 if (len > UINT_MAX) {
1254 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1255 (unsigned long long)len, UINT_MAX);
1256 ti->error = "Maximum size of target IO is too large";
1260 ti->max_io_len = (uint32_t) len;
1264 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
1267 * A target may call dm_accept_partial_bio only from the map routine. It is
1268 * allowed for all bio types except REQ_FLUSH.
1270 * dm_accept_partial_bio informs the dm that the target only wants to process
1271 * additional n_sectors sectors of the bio and the rest of the data should be
1272 * sent in a next bio.
1274 * A diagram that explains the arithmetics:
1275 * +--------------------+---------------+-------+
1277 * +--------------------+---------------+-------+
1279 * <-------------- *tio->len_ptr --------------->
1280 * <------- bi_size ------->
1283 * Region 1 was already iterated over with bio_advance or similar function.
1284 * (it may be empty if the target doesn't use bio_advance)
1285 * Region 2 is the remaining bio size that the target wants to process.
1286 * (it may be empty if region 1 is non-empty, although there is no reason
1288 * The target requires that region 3 is to be sent in the next bio.
1290 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1291 * the partially processed part (the sum of regions 1+2) must be the same for all
1292 * copies of the bio.
1294 void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
1296 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1297 unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
1298 BUG_ON(bio->bi_rw & REQ_FLUSH);
1299 BUG_ON(bi_size > *tio->len_ptr);
1300 BUG_ON(n_sectors > bi_size);
1301 *tio->len_ptr -= bi_size - n_sectors;
1302 bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
1304 EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
1306 static void __map_bio(struct dm_target_io *tio)
1310 struct mapped_device *md;
1311 struct bio *clone = &tio->clone;
1312 struct dm_target *ti = tio->ti;
1314 clone->bi_end_io = clone_endio;
1317 * Map the clone. If r == 0 we don't need to do
1318 * anything, the target has assumed ownership of
1321 atomic_inc(&tio->io->io_count);
1322 sector = clone->bi_iter.bi_sector;
1323 r = ti->type->map(ti, clone);
1324 if (r == DM_MAPIO_REMAPPED) {
1325 /* the bio has been remapped so dispatch it */
1327 trace_block_bio_remap(bdev_get_queue(clone->bi_bdev), clone,
1328 tio->io->bio->bi_bdev->bd_dev, sector);
1330 generic_make_request(clone);
1331 } else if (r < 0 || r == DM_MAPIO_REQUEUE) {
1332 /* error the io and bail out, or requeue it if needed */
1334 dec_pending(tio->io, r);
1337 DMWARN("unimplemented target map return value: %d", r);
1343 struct mapped_device *md;
1344 struct dm_table *map;
1348 unsigned sector_count;
1351 static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
1353 bio->bi_iter.bi_sector = sector;
1354 bio->bi_iter.bi_size = to_bytes(len);
1358 * Creates a bio that consists of range of complete bvecs.
1360 static void clone_bio(struct dm_target_io *tio, struct bio *bio,
1361 sector_t sector, unsigned len)
1363 struct bio *clone = &tio->clone;
1365 __bio_clone_fast(clone, bio);
1367 if (bio_integrity(bio))
1368 bio_integrity_clone(clone, bio, GFP_NOIO);
1370 bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
1371 clone->bi_iter.bi_size = to_bytes(len);
1373 if (bio_integrity(bio))
1374 bio_integrity_trim(clone, 0, len);
1377 static struct dm_target_io *alloc_tio(struct clone_info *ci,
1378 struct dm_target *ti,
1379 unsigned target_bio_nr)
1381 struct dm_target_io *tio;
1384 clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
1385 tio = container_of(clone, struct dm_target_io, clone);
1389 tio->target_bio_nr = target_bio_nr;
1394 static void __clone_and_map_simple_bio(struct clone_info *ci,
1395 struct dm_target *ti,
1396 unsigned target_bio_nr, unsigned *len)
1398 struct dm_target_io *tio = alloc_tio(ci, ti, target_bio_nr);
1399 struct bio *clone = &tio->clone;
1403 __bio_clone_fast(clone, ci->bio);
1405 bio_setup_sector(clone, ci->sector, *len);
1410 static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
1411 unsigned num_bios, unsigned *len)
1413 unsigned target_bio_nr;
1415 for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++)
1416 __clone_and_map_simple_bio(ci, ti, target_bio_nr, len);
1419 static int __send_empty_flush(struct clone_info *ci)
1421 unsigned target_nr = 0;
1422 struct dm_target *ti;
1424 BUG_ON(bio_has_data(ci->bio));
1425 while ((ti = dm_table_get_target(ci->map, target_nr++)))
1426 __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
1431 static void __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
1432 sector_t sector, unsigned *len)
1434 struct bio *bio = ci->bio;
1435 struct dm_target_io *tio;
1436 unsigned target_bio_nr;
1437 unsigned num_target_bios = 1;
1440 * Does the target want to receive duplicate copies of the bio?
1442 if (bio_data_dir(bio) == WRITE && ti->num_write_bios)
1443 num_target_bios = ti->num_write_bios(ti, bio);
1445 for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
1446 tio = alloc_tio(ci, ti, target_bio_nr);
1448 clone_bio(tio, bio, sector, *len);
1453 typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
1455 static unsigned get_num_discard_bios(struct dm_target *ti)
1457 return ti->num_discard_bios;
1460 static unsigned get_num_write_same_bios(struct dm_target *ti)
1462 return ti->num_write_same_bios;
1465 typedef bool (*is_split_required_fn)(struct dm_target *ti);
1467 static bool is_split_required_for_discard(struct dm_target *ti)
1469 return ti->split_discard_bios;
1472 static int __send_changing_extent_only(struct clone_info *ci,
1473 get_num_bios_fn get_num_bios,
1474 is_split_required_fn is_split_required)
1476 struct dm_target *ti;
1481 ti = dm_table_find_target(ci->map, ci->sector);
1482 if (!dm_target_is_valid(ti))
1486 * Even though the device advertised support for this type of
1487 * request, that does not mean every target supports it, and
1488 * reconfiguration might also have changed that since the
1489 * check was performed.
1491 num_bios = get_num_bios ? get_num_bios(ti) : 0;
1495 if (is_split_required && !is_split_required(ti))
1496 len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
1498 len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
1500 __send_duplicate_bios(ci, ti, num_bios, &len);
1503 } while (ci->sector_count -= len);
1508 static int __send_discard(struct clone_info *ci)
1510 return __send_changing_extent_only(ci, get_num_discard_bios,
1511 is_split_required_for_discard);
1514 static int __send_write_same(struct clone_info *ci)
1516 return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
1520 * Select the correct strategy for processing a non-flush bio.
1522 static int __split_and_process_non_flush(struct clone_info *ci)
1524 struct bio *bio = ci->bio;
1525 struct dm_target *ti;
1528 if (unlikely(bio->bi_rw & REQ_DISCARD))
1529 return __send_discard(ci);
1530 else if (unlikely(bio->bi_rw & REQ_WRITE_SAME))
1531 return __send_write_same(ci);
1533 ti = dm_table_find_target(ci->map, ci->sector);
1534 if (!dm_target_is_valid(ti))
1537 len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count);
1539 __clone_and_map_data_bio(ci, ti, ci->sector, &len);
1542 ci->sector_count -= len;
1548 * Entry point to split a bio into clones and submit them to the targets.
1550 static void __split_and_process_bio(struct mapped_device *md,
1551 struct dm_table *map, struct bio *bio)
1553 struct clone_info ci;
1556 if (unlikely(!map)) {
1563 ci.io = alloc_io(md);
1565 atomic_set(&ci.io->io_count, 1);
1568 spin_lock_init(&ci.io->endio_lock);
1569 ci.sector = bio->bi_iter.bi_sector;
1571 start_io_acct(ci.io);
1573 if (bio->bi_rw & REQ_FLUSH) {
1574 ci.bio = &ci.md->flush_bio;
1575 ci.sector_count = 0;
1576 error = __send_empty_flush(&ci);
1577 /* dec_pending submits any data associated with flush */
1580 ci.sector_count = bio_sectors(bio);
1581 while (ci.sector_count && !error)
1582 error = __split_and_process_non_flush(&ci);
1585 /* drop the extra reference count */
1586 dec_pending(ci.io, error);
1588 /*-----------------------------------------------------------------
1590 *---------------------------------------------------------------*/
1592 static int dm_merge_bvec(struct request_queue *q,
1593 struct bvec_merge_data *bvm,
1594 struct bio_vec *biovec)
1596 struct mapped_device *md = q->queuedata;
1597 struct dm_table *map = dm_get_live_table_fast(md);
1598 struct dm_target *ti;
1599 sector_t max_sectors;
1605 ti = dm_table_find_target(map, bvm->bi_sector);
1606 if (!dm_target_is_valid(ti))
1610 * Find maximum amount of I/O that won't need splitting
1612 max_sectors = min(max_io_len(bvm->bi_sector, ti),
1613 (sector_t) queue_max_sectors(q));
1614 max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size;
1615 if (unlikely(max_size < 0)) /* this shouldn't _ever_ happen */
1619 * merge_bvec_fn() returns number of bytes
1620 * it can accept at this offset
1621 * max is precomputed maximal io size
1623 if (max_size && ti->type->merge)
1624 max_size = ti->type->merge(ti, bvm, biovec, max_size);
1626 * If the target doesn't support merge method and some of the devices
1627 * provided their merge_bvec method (we know this by looking for the
1628 * max_hw_sectors that dm_set_device_limits may set), then we can't
1629 * allow bios with multiple vector entries. So always set max_size
1630 * to 0, and the code below allows just one page.
1632 else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9)
1636 dm_put_live_table_fast(md);
1638 * Always allow an entire first page
1640 if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT))
1641 max_size = biovec->bv_len;
1647 * The request function that just remaps the bio built up by
1650 static void _dm_request(struct request_queue *q, struct bio *bio)
1652 int rw = bio_data_dir(bio);
1653 struct mapped_device *md = q->queuedata;
1655 struct dm_table *map;
1657 map = dm_get_live_table(md, &srcu_idx);
1659 generic_start_io_acct(rw, bio_sectors(bio), &dm_disk(md)->part0);
1661 /* if we're suspended, we have to queue this io for later */
1662 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
1663 dm_put_live_table(md, srcu_idx);
1665 if (bio_rw(bio) != READA)
1672 __split_and_process_bio(md, map, bio);
1673 dm_put_live_table(md, srcu_idx);
1677 int dm_request_based(struct mapped_device *md)
1679 return blk_queue_stackable(md->queue);
1682 static void dm_request(struct request_queue *q, struct bio *bio)
1684 struct mapped_device *md = q->queuedata;
1686 if (dm_request_based(md))
1687 blk_queue_bio(q, bio);
1689 _dm_request(q, bio);
1692 void dm_dispatch_request(struct request *rq)
1696 if (blk_queue_io_stat(rq->q))
1697 rq->cmd_flags |= REQ_IO_STAT;
1699 rq->start_time = jiffies;
1700 r = blk_insert_cloned_request(rq->q, rq);
1702 dm_complete_request(rq, r);
1704 EXPORT_SYMBOL_GPL(dm_dispatch_request);
1706 static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig,
1709 struct dm_rq_target_io *tio = data;
1710 struct dm_rq_clone_bio_info *info =
1711 container_of(bio, struct dm_rq_clone_bio_info, clone);
1713 info->orig = bio_orig;
1715 bio->bi_end_io = end_clone_bio;
1720 static int setup_clone(struct request *clone, struct request *rq,
1721 struct dm_rq_target_io *tio)
1725 blk_rq_init(NULL, clone);
1726 r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
1727 dm_rq_bio_constructor, tio);
1731 clone->cmd = rq->cmd;
1732 clone->cmd_len = rq->cmd_len;
1733 clone->sense = rq->sense;
1734 clone->end_io = end_clone_request;
1735 clone->end_io_data = tio;
1740 static struct request *clone_rq(struct request *rq, struct mapped_device *md,
1743 struct request *clone;
1744 struct dm_rq_target_io *tio;
1746 tio = alloc_rq_tio(md, gfp_mask);
1754 memset(&tio->info, 0, sizeof(tio->info));
1756 clone = &tio->clone;
1757 if (setup_clone(clone, rq, tio)) {
1767 * Called with the queue lock held.
1769 static int dm_prep_fn(struct request_queue *q, struct request *rq)
1771 struct mapped_device *md = q->queuedata;
1772 struct request *clone;
1774 if (unlikely(rq->special)) {
1775 DMWARN("Already has something in rq->special.");
1776 return BLKPREP_KILL;
1779 clone = clone_rq(rq, md, GFP_ATOMIC);
1781 return BLKPREP_DEFER;
1783 rq->special = clone;
1784 rq->cmd_flags |= REQ_DONTPREP;
1791 * 0 : the request has been processed (not requeued)
1792 * !0 : the request has been requeued
1794 static int map_request(struct dm_target *ti, struct request *clone,
1795 struct mapped_device *md)
1797 int r, requeued = 0;
1798 struct dm_rq_target_io *tio = clone->end_io_data;
1801 r = ti->type->map_rq(ti, clone, &tio->info);
1803 case DM_MAPIO_SUBMITTED:
1804 /* The target has taken the I/O to submit by itself later */
1806 case DM_MAPIO_REMAPPED:
1807 /* The target has remapped the I/O so dispatch it */
1808 trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
1809 blk_rq_pos(tio->orig));
1810 dm_dispatch_request(clone);
1812 case DM_MAPIO_REQUEUE:
1813 /* The target wants to requeue the I/O */
1814 dm_requeue_unmapped_request(clone);
1819 DMWARN("unimplemented target map return value: %d", r);
1823 /* The target wants to complete the I/O */
1824 dm_kill_unmapped_request(clone, r);
1831 static struct request *dm_start_request(struct mapped_device *md, struct request *orig)
1833 struct request *clone;
1835 blk_start_request(orig);
1836 clone = orig->special;
1837 atomic_inc(&md->pending[rq_data_dir(clone)]);
1840 * Hold the md reference here for the in-flight I/O.
1841 * We can't rely on the reference count by device opener,
1842 * because the device may be closed during the request completion
1843 * when all bios are completed.
1844 * See the comment in rq_completed() too.
1852 * q->request_fn for request-based dm.
1853 * Called with the queue lock held.
1855 static void dm_request_fn(struct request_queue *q)
1857 struct mapped_device *md = q->queuedata;
1859 struct dm_table *map = dm_get_live_table(md, &srcu_idx);
1860 struct dm_target *ti;
1861 struct request *rq, *clone;
1865 * For suspend, check blk_queue_stopped() and increment
1866 * ->pending within a single queue_lock not to increment the
1867 * number of in-flight I/Os after the queue is stopped in
1870 while (!blk_queue_stopped(q)) {
1871 rq = blk_peek_request(q);
1875 /* always use block 0 to find the target for flushes for now */
1877 if (!(rq->cmd_flags & REQ_FLUSH))
1878 pos = blk_rq_pos(rq);
1880 ti = dm_table_find_target(map, pos);
1881 if (!dm_target_is_valid(ti)) {
1883 * Must perform setup, that dm_done() requires,
1884 * before calling dm_kill_unmapped_request
1886 DMERR_LIMIT("request attempted access beyond the end of device");
1887 clone = dm_start_request(md, rq);
1888 dm_kill_unmapped_request(clone, -EIO);
1892 if (ti->type->busy && ti->type->busy(ti))
1895 clone = dm_start_request(md, rq);
1897 spin_unlock(q->queue_lock);
1898 if (map_request(ti, clone, md))
1901 BUG_ON(!irqs_disabled());
1902 spin_lock(q->queue_lock);
1908 BUG_ON(!irqs_disabled());
1909 spin_lock(q->queue_lock);
1912 blk_delay_queue(q, HZ / 10);
1914 dm_put_live_table(md, srcu_idx);
1917 int dm_underlying_device_busy(struct request_queue *q)
1919 return blk_lld_busy(q);
1921 EXPORT_SYMBOL_GPL(dm_underlying_device_busy);
1923 static int dm_lld_busy(struct request_queue *q)
1926 struct mapped_device *md = q->queuedata;
1927 struct dm_table *map = dm_get_live_table_fast(md);
1929 if (!map || test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))
1932 r = dm_table_any_busy_target(map);
1934 dm_put_live_table_fast(md);
1939 static int dm_any_congested(void *congested_data, int bdi_bits)
1942 struct mapped_device *md = congested_data;
1943 struct dm_table *map;
1945 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
1946 map = dm_get_live_table_fast(md);
1949 * Request-based dm cares about only own queue for
1950 * the query about congestion status of request_queue
1952 if (dm_request_based(md))
1953 r = md->queue->backing_dev_info.state &
1956 r = dm_table_any_congested(map, bdi_bits);
1958 dm_put_live_table_fast(md);
1964 /*-----------------------------------------------------------------
1965 * An IDR is used to keep track of allocated minor numbers.
1966 *---------------------------------------------------------------*/
1967 static void free_minor(int minor)
1969 spin_lock(&_minor_lock);
1970 idr_remove(&_minor_idr, minor);
1971 spin_unlock(&_minor_lock);
1975 * See if the device with a specific minor # is free.
1977 static int specific_minor(int minor)
1981 if (minor >= (1 << MINORBITS))
1984 idr_preload(GFP_KERNEL);
1985 spin_lock(&_minor_lock);
1987 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
1989 spin_unlock(&_minor_lock);
1992 return r == -ENOSPC ? -EBUSY : r;
1996 static int next_free_minor(int *minor)
2000 idr_preload(GFP_KERNEL);
2001 spin_lock(&_minor_lock);
2003 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
2005 spin_unlock(&_minor_lock);
2013 static const struct block_device_operations dm_blk_dops;
2015 static void dm_wq_work(struct work_struct *work);
2017 static void dm_init_md_queue(struct mapped_device *md)
2020 * Request-based dm devices cannot be stacked on top of bio-based dm
2021 * devices. The type of this dm device has not been decided yet.
2022 * The type is decided at the first table loading time.
2023 * To prevent problematic device stacking, clear the queue flag
2024 * for request stacking support until then.
2026 * This queue is new, so no concurrency on the queue_flags.
2028 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
2030 md->queue->queuedata = md;
2031 md->queue->backing_dev_info.congested_fn = dm_any_congested;
2032 md->queue->backing_dev_info.congested_data = md;
2033 blk_queue_make_request(md->queue, dm_request);
2034 blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
2035 blk_queue_merge_bvec(md->queue, dm_merge_bvec);
2039 * Allocate and initialise a blank device with a given minor.
2041 static struct mapped_device *alloc_dev(int minor)
2044 struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL);
2048 DMWARN("unable to allocate device, out of memory.");
2052 if (!try_module_get(THIS_MODULE))
2053 goto bad_module_get;
2055 /* get a minor number for the dev */
2056 if (minor == DM_ANY_MINOR)
2057 r = next_free_minor(&minor);
2059 r = specific_minor(minor);
2063 r = init_srcu_struct(&md->io_barrier);
2065 goto bad_io_barrier;
2067 md->type = DM_TYPE_NONE;
2068 mutex_init(&md->suspend_lock);
2069 mutex_init(&md->type_lock);
2070 mutex_init(&md->table_devices_lock);
2071 spin_lock_init(&md->deferred_lock);
2072 atomic_set(&md->holders, 1);
2073 atomic_set(&md->open_count, 0);
2074 atomic_set(&md->event_nr, 0);
2075 atomic_set(&md->uevent_seq, 0);
2076 INIT_LIST_HEAD(&md->uevent_list);
2077 INIT_LIST_HEAD(&md->table_devices);
2078 spin_lock_init(&md->uevent_lock);
2080 md->queue = blk_alloc_queue(GFP_KERNEL);
2084 dm_init_md_queue(md);
2086 md->disk = alloc_disk(1);
2090 atomic_set(&md->pending[0], 0);
2091 atomic_set(&md->pending[1], 0);
2092 init_waitqueue_head(&md->wait);
2093 INIT_WORK(&md->work, dm_wq_work);
2094 init_waitqueue_head(&md->eventq);
2095 init_completion(&md->kobj_holder.completion);
2097 md->disk->major = _major;
2098 md->disk->first_minor = minor;
2099 md->disk->fops = &dm_blk_dops;
2100 md->disk->queue = md->queue;
2101 md->disk->private_data = md;
2102 sprintf(md->disk->disk_name, "dm-%d", minor);
2104 format_dev_t(md->name, MKDEV(_major, minor));
2106 md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
2110 md->bdev = bdget_disk(md->disk, 0);
2114 bio_init(&md->flush_bio);
2115 md->flush_bio.bi_bdev = md->bdev;
2116 md->flush_bio.bi_rw = WRITE_FLUSH;
2118 dm_stats_init(&md->stats);
2120 /* Populate the mapping, nobody knows we exist yet */
2121 spin_lock(&_minor_lock);
2122 old_md = idr_replace(&_minor_idr, md, minor);
2123 spin_unlock(&_minor_lock);
2125 BUG_ON(old_md != MINOR_ALLOCED);
2130 destroy_workqueue(md->wq);
2132 del_gendisk(md->disk);
2135 blk_cleanup_queue(md->queue);
2137 cleanup_srcu_struct(&md->io_barrier);
2141 module_put(THIS_MODULE);
2147 static void unlock_fs(struct mapped_device *md);
2149 static void free_dev(struct mapped_device *md)
2151 int minor = MINOR(disk_devt(md->disk));
2155 destroy_workqueue(md->wq);
2157 mempool_destroy(md->io_pool);
2159 bioset_free(md->bs);
2160 blk_integrity_unregister(md->disk);
2161 del_gendisk(md->disk);
2162 cleanup_srcu_struct(&md->io_barrier);
2163 free_table_devices(&md->table_devices);
2166 spin_lock(&_minor_lock);
2167 md->disk->private_data = NULL;
2168 spin_unlock(&_minor_lock);
2171 blk_cleanup_queue(md->queue);
2172 dm_stats_cleanup(&md->stats);
2173 module_put(THIS_MODULE);
2177 static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
2179 struct dm_md_mempools *p = dm_table_get_md_mempools(t);
2181 if (md->io_pool && md->bs) {
2182 /* The md already has necessary mempools. */
2183 if (dm_table_get_type(t) == DM_TYPE_BIO_BASED) {
2185 * Reload bioset because front_pad may have changed
2186 * because a different table was loaded.
2188 bioset_free(md->bs);
2191 } else if (dm_table_get_type(t) == DM_TYPE_REQUEST_BASED) {
2193 * There's no need to reload with request-based dm
2194 * because the size of front_pad doesn't change.
2195 * Note for future: If you are to reload bioset,
2196 * prep-ed requests in the queue may refer
2197 * to bio from the old bioset, so you must walk
2198 * through the queue to unprep.
2204 BUG_ON(!p || md->io_pool || md->bs);
2206 md->io_pool = p->io_pool;
2212 /* mempool bind completed, now no need any mempools in the table */
2213 dm_table_free_md_mempools(t);
2217 * Bind a table to the device.
2219 static void event_callback(void *context)
2221 unsigned long flags;
2223 struct mapped_device *md = (struct mapped_device *) context;
2225 spin_lock_irqsave(&md->uevent_lock, flags);
2226 list_splice_init(&md->uevent_list, &uevents);
2227 spin_unlock_irqrestore(&md->uevent_lock, flags);
2229 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
2231 atomic_inc(&md->event_nr);
2232 wake_up(&md->eventq);
2236 * Protected by md->suspend_lock obtained by dm_swap_table().
2238 static void __set_size(struct mapped_device *md, sector_t size)
2240 set_capacity(md->disk, size);
2242 i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
2246 * Return 1 if the queue has a compulsory merge_bvec_fn function.
2248 * If this function returns 0, then the device is either a non-dm
2249 * device without a merge_bvec_fn, or it is a dm device that is
2250 * able to split any bios it receives that are too big.
2252 int dm_queue_merge_is_compulsory(struct request_queue *q)
2254 struct mapped_device *dev_md;
2256 if (!q->merge_bvec_fn)
2259 if (q->make_request_fn == dm_request) {
2260 dev_md = q->queuedata;
2261 if (test_bit(DMF_MERGE_IS_OPTIONAL, &dev_md->flags))
2268 static int dm_device_merge_is_compulsory(struct dm_target *ti,
2269 struct dm_dev *dev, sector_t start,
2270 sector_t len, void *data)
2272 struct block_device *bdev = dev->bdev;
2273 struct request_queue *q = bdev_get_queue(bdev);
2275 return dm_queue_merge_is_compulsory(q);
2279 * Return 1 if it is acceptable to ignore merge_bvec_fn based
2280 * on the properties of the underlying devices.
2282 static int dm_table_merge_is_optional(struct dm_table *table)
2285 struct dm_target *ti;
2287 while (i < dm_table_get_num_targets(table)) {
2288 ti = dm_table_get_target(table, i++);
2290 if (ti->type->iterate_devices &&
2291 ti->type->iterate_devices(ti, dm_device_merge_is_compulsory, NULL))
2299 * Returns old map, which caller must destroy.
2301 static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
2302 struct queue_limits *limits)
2304 struct dm_table *old_map;
2305 struct request_queue *q = md->queue;
2307 int merge_is_optional;
2309 size = dm_table_get_size(t);
2312 * Wipe any geometry if the size of the table changed.
2314 if (size != dm_get_size(md))
2315 memset(&md->geometry, 0, sizeof(md->geometry));
2317 __set_size(md, size);
2319 dm_table_event_callback(t, event_callback, md);
2322 * The queue hasn't been stopped yet, if the old table type wasn't
2323 * for request-based during suspension. So stop it to prevent
2324 * I/O mapping before resume.
2325 * This must be done before setting the queue restrictions,
2326 * because request-based dm may be run just after the setting.
2328 if (dm_table_request_based(t) && !blk_queue_stopped(q))
2331 __bind_mempools(md, t);
2333 merge_is_optional = dm_table_merge_is_optional(t);
2335 old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2336 rcu_assign_pointer(md->map, t);
2337 md->immutable_target_type = dm_table_get_immutable_target_type(t);
2339 dm_table_set_restrictions(t, q, limits);
2340 if (merge_is_optional)
2341 set_bit(DMF_MERGE_IS_OPTIONAL, &md->flags);
2343 clear_bit(DMF_MERGE_IS_OPTIONAL, &md->flags);
2351 * Returns unbound table for the caller to free.
2353 static struct dm_table *__unbind(struct mapped_device *md)
2355 struct dm_table *map = rcu_dereference_protected(md->map, 1);
2360 dm_table_event_callback(map, NULL, NULL);
2361 RCU_INIT_POINTER(md->map, NULL);
2368 * Constructor for a new device.
2370 int dm_create(int minor, struct mapped_device **result)
2372 struct mapped_device *md;
2374 md = alloc_dev(minor);
2385 * Functions to manage md->type.
2386 * All are required to hold md->type_lock.
2388 void dm_lock_md_type(struct mapped_device *md)
2390 mutex_lock(&md->type_lock);
2393 void dm_unlock_md_type(struct mapped_device *md)
2395 mutex_unlock(&md->type_lock);
2398 void dm_set_md_type(struct mapped_device *md, unsigned type)
2400 BUG_ON(!mutex_is_locked(&md->type_lock));
2404 unsigned dm_get_md_type(struct mapped_device *md)
2406 BUG_ON(!mutex_is_locked(&md->type_lock));
2410 struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
2412 return md->immutable_target_type;
2416 * The queue_limits are only valid as long as you have a reference
2419 struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
2421 BUG_ON(!atomic_read(&md->holders));
2422 return &md->queue->limits;
2424 EXPORT_SYMBOL_GPL(dm_get_queue_limits);
2427 * Fully initialize a request-based queue (->elevator, ->request_fn, etc).
2429 static int dm_init_request_based_queue(struct mapped_device *md)
2431 struct request_queue *q = NULL;
2433 if (md->queue->elevator)
2436 /* Fully initialize the queue */
2437 q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL);
2442 dm_init_md_queue(md);
2443 blk_queue_softirq_done(md->queue, dm_softirq_done);
2444 blk_queue_prep_rq(md->queue, dm_prep_fn);
2445 blk_queue_lld_busy(md->queue, dm_lld_busy);
2447 elv_register_queue(md->queue);
2453 * Setup the DM device's queue based on md's type
2455 int dm_setup_md_queue(struct mapped_device *md)
2457 if ((dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) &&
2458 !dm_init_request_based_queue(md)) {
2459 DMWARN("Cannot initialize queue for request-based mapped device");
2466 static struct mapped_device *dm_find_md(dev_t dev)
2468 struct mapped_device *md;
2469 unsigned minor = MINOR(dev);
2471 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
2474 spin_lock(&_minor_lock);
2476 md = idr_find(&_minor_idr, minor);
2477 if (md && (md == MINOR_ALLOCED ||
2478 (MINOR(disk_devt(dm_disk(md))) != minor) ||
2479 dm_deleting_md(md) ||
2480 test_bit(DMF_FREEING, &md->flags))) {
2486 spin_unlock(&_minor_lock);
2491 struct mapped_device *dm_get_md(dev_t dev)
2493 struct mapped_device *md = dm_find_md(dev);
2500 EXPORT_SYMBOL_GPL(dm_get_md);
2502 void *dm_get_mdptr(struct mapped_device *md)
2504 return md->interface_ptr;
2507 void dm_set_mdptr(struct mapped_device *md, void *ptr)
2509 md->interface_ptr = ptr;
2512 void dm_get(struct mapped_device *md)
2514 atomic_inc(&md->holders);
2515 BUG_ON(test_bit(DMF_FREEING, &md->flags));
2518 const char *dm_device_name(struct mapped_device *md)
2522 EXPORT_SYMBOL_GPL(dm_device_name);
2524 static void __dm_destroy(struct mapped_device *md, bool wait)
2526 struct dm_table *map;
2531 spin_lock(&_minor_lock);
2532 map = dm_get_live_table(md, &srcu_idx);
2533 idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
2534 set_bit(DMF_FREEING, &md->flags);
2535 spin_unlock(&_minor_lock);
2537 if (!dm_suspended_md(md)) {
2538 dm_table_presuspend_targets(map);
2539 dm_table_postsuspend_targets(map);
2542 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2543 dm_put_live_table(md, srcu_idx);
2546 * Rare, but there may be I/O requests still going to complete,
2547 * for example. Wait for all references to disappear.
2548 * No one should increment the reference count of the mapped_device,
2549 * after the mapped_device state becomes DMF_FREEING.
2552 while (atomic_read(&md->holders))
2554 else if (atomic_read(&md->holders))
2555 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2556 dm_device_name(md), atomic_read(&md->holders));
2559 dm_table_destroy(__unbind(md));
2563 void dm_destroy(struct mapped_device *md)
2565 __dm_destroy(md, true);
2568 void dm_destroy_immediate(struct mapped_device *md)
2570 __dm_destroy(md, false);
2573 void dm_put(struct mapped_device *md)
2575 atomic_dec(&md->holders);
2577 EXPORT_SYMBOL_GPL(dm_put);
2579 static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
2582 DECLARE_WAITQUEUE(wait, current);
2584 add_wait_queue(&md->wait, &wait);
2587 set_current_state(interruptible);
2589 if (!md_in_flight(md))
2592 if (interruptible == TASK_INTERRUPTIBLE &&
2593 signal_pending(current)) {
2600 set_current_state(TASK_RUNNING);
2602 remove_wait_queue(&md->wait, &wait);
2608 * Process the deferred bios
2610 static void dm_wq_work(struct work_struct *work)
2612 struct mapped_device *md = container_of(work, struct mapped_device,
2616 struct dm_table *map;
2618 map = dm_get_live_table(md, &srcu_idx);
2620 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
2621 spin_lock_irq(&md->deferred_lock);
2622 c = bio_list_pop(&md->deferred);
2623 spin_unlock_irq(&md->deferred_lock);
2628 if (dm_request_based(md))
2629 generic_make_request(c);
2631 __split_and_process_bio(md, map, c);
2634 dm_put_live_table(md, srcu_idx);
2637 static void dm_queue_flush(struct mapped_device *md)
2639 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2640 smp_mb__after_atomic();
2641 queue_work(md->wq, &md->work);
2645 * Swap in a new table, returning the old one for the caller to destroy.
2647 struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
2649 struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
2650 struct queue_limits limits;
2653 mutex_lock(&md->suspend_lock);
2655 /* device must be suspended */
2656 if (!dm_suspended_md(md))
2660 * If the new table has no data devices, retain the existing limits.
2661 * This helps multipath with queue_if_no_path if all paths disappear,
2662 * then new I/O is queued based on these limits, and then some paths
2665 if (dm_table_has_no_data_devices(table)) {
2666 live_map = dm_get_live_table_fast(md);
2668 limits = md->queue->limits;
2669 dm_put_live_table_fast(md);
2673 r = dm_calculate_queue_limits(table, &limits);
2680 map = __bind(md, table, &limits);
2683 mutex_unlock(&md->suspend_lock);
2688 * Functions to lock and unlock any filesystem running on the
2691 static int lock_fs(struct mapped_device *md)
2695 WARN_ON(md->frozen_sb);
2697 md->frozen_sb = freeze_bdev(md->bdev);
2698 if (IS_ERR(md->frozen_sb)) {
2699 r = PTR_ERR(md->frozen_sb);
2700 md->frozen_sb = NULL;
2704 set_bit(DMF_FROZEN, &md->flags);
2709 static void unlock_fs(struct mapped_device *md)
2711 if (!test_bit(DMF_FROZEN, &md->flags))
2714 thaw_bdev(md->bdev, md->frozen_sb);
2715 md->frozen_sb = NULL;
2716 clear_bit(DMF_FROZEN, &md->flags);
2720 * If __dm_suspend returns 0, the device is completely quiescent
2721 * now. There is no request-processing activity. All new requests
2722 * are being added to md->deferred list.
2724 * Caller must hold md->suspend_lock
2726 static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
2727 unsigned suspend_flags, int interruptible)
2729 bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
2730 bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
2734 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2735 * This flag is cleared before dm_suspend returns.
2738 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2741 * This gets reverted if there's an error later and the targets
2742 * provide the .presuspend_undo hook.
2744 dm_table_presuspend_targets(map);
2747 * Flush I/O to the device.
2748 * Any I/O submitted after lock_fs() may not be flushed.
2749 * noflush takes precedence over do_lockfs.
2750 * (lock_fs() flushes I/Os and waits for them to complete.)
2752 if (!noflush && do_lockfs) {
2755 dm_table_presuspend_undo_targets(map);
2761 * Here we must make sure that no processes are submitting requests
2762 * to target drivers i.e. no one may be executing
2763 * __split_and_process_bio. This is called from dm_request and
2766 * To get all processes out of __split_and_process_bio in dm_request,
2767 * we take the write lock. To prevent any process from reentering
2768 * __split_and_process_bio from dm_request and quiesce the thread
2769 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2770 * flush_workqueue(md->wq).
2772 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2774 synchronize_srcu(&md->io_barrier);
2777 * Stop md->queue before flushing md->wq in case request-based
2778 * dm defers requests to md->wq from md->queue.
2780 if (dm_request_based(md))
2781 stop_queue(md->queue);
2783 flush_workqueue(md->wq);
2786 * At this point no more requests are entering target request routines.
2787 * We call dm_wait_for_completion to wait for all existing requests
2790 r = dm_wait_for_completion(md, interruptible);
2793 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2795 synchronize_srcu(&md->io_barrier);
2797 /* were we interrupted ? */
2801 if (dm_request_based(md))
2802 start_queue(md->queue);
2805 dm_table_presuspend_undo_targets(map);
2806 /* pushback list is already flushed, so skip flush */
2813 * We need to be able to change a mapping table under a mounted
2814 * filesystem. For example we might want to move some data in
2815 * the background. Before the table can be swapped with
2816 * dm_bind_table, dm_suspend must be called to flush any in
2817 * flight bios and ensure that any further io gets deferred.
2820 * Suspend mechanism in request-based dm.
2822 * 1. Flush all I/Os by lock_fs() if needed.
2823 * 2. Stop dispatching any I/O by stopping the request_queue.
2824 * 3. Wait for all in-flight I/Os to be completed or requeued.
2826 * To abort suspend, start the request_queue.
2828 int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
2830 struct dm_table *map = NULL;
2834 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2836 if (dm_suspended_md(md)) {
2841 if (dm_suspended_internally_md(md)) {
2842 /* already internally suspended, wait for internal resume */
2843 mutex_unlock(&md->suspend_lock);
2844 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2850 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2852 r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE);
2856 set_bit(DMF_SUSPENDED, &md->flags);
2858 dm_table_postsuspend_targets(map);
2861 mutex_unlock(&md->suspend_lock);
2865 static int __dm_resume(struct mapped_device *md, struct dm_table *map)
2868 int r = dm_table_resume_targets(map);
2876 * Flushing deferred I/Os must be done after targets are resumed
2877 * so that mapping of targets can work correctly.
2878 * Request-based dm is queueing the deferred I/Os in its request_queue.
2880 if (dm_request_based(md))
2881 start_queue(md->queue);
2888 int dm_resume(struct mapped_device *md)
2891 struct dm_table *map = NULL;
2894 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2896 if (!dm_suspended_md(md))
2899 if (dm_suspended_internally_md(md)) {
2900 /* already internally suspended, wait for internal resume */
2901 mutex_unlock(&md->suspend_lock);
2902 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2908 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2909 if (!map || !dm_table_get_size(map))
2912 r = __dm_resume(md, map);
2916 clear_bit(DMF_SUSPENDED, &md->flags);
2920 mutex_unlock(&md->suspend_lock);
2926 * Internal suspend/resume works like userspace-driven suspend. It waits
2927 * until all bios finish and prevents issuing new bios to the target drivers.
2928 * It may be used only from the kernel.
2931 static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
2933 struct dm_table *map = NULL;
2935 if (md->internal_suspend_count++)
2936 return; /* nested internal suspend */
2938 if (dm_suspended_md(md)) {
2939 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2940 return; /* nest suspend */
2943 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2946 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
2947 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
2948 * would require changing .presuspend to return an error -- avoid this
2949 * until there is a need for more elaborate variants of internal suspend.
2951 (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE);
2953 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2955 dm_table_postsuspend_targets(map);
2958 static void __dm_internal_resume(struct mapped_device *md)
2960 BUG_ON(!md->internal_suspend_count);
2962 if (--md->internal_suspend_count)
2963 return; /* resume from nested internal suspend */
2965 if (dm_suspended_md(md))
2966 goto done; /* resume from nested suspend */
2969 * NOTE: existing callers don't need to call dm_table_resume_targets
2970 * (which may fail -- so best to avoid it for now by passing NULL map)
2972 (void) __dm_resume(md, NULL);
2975 clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2976 smp_mb__after_atomic();
2977 wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
2980 void dm_internal_suspend_noflush(struct mapped_device *md)
2982 mutex_lock(&md->suspend_lock);
2983 __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
2984 mutex_unlock(&md->suspend_lock);
2986 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
2988 void dm_internal_resume(struct mapped_device *md)
2990 mutex_lock(&md->suspend_lock);
2991 __dm_internal_resume(md);
2992 mutex_unlock(&md->suspend_lock);
2994 EXPORT_SYMBOL_GPL(dm_internal_resume);
2997 * Fast variants of internal suspend/resume hold md->suspend_lock,
2998 * which prevents interaction with userspace-driven suspend.
3001 void dm_internal_suspend_fast(struct mapped_device *md)
3003 mutex_lock(&md->suspend_lock);
3004 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
3007 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
3008 synchronize_srcu(&md->io_barrier);
3009 flush_workqueue(md->wq);
3010 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
3013 void dm_internal_resume_fast(struct mapped_device *md)
3015 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
3021 mutex_unlock(&md->suspend_lock);
3024 /*-----------------------------------------------------------------
3025 * Event notification.
3026 *---------------------------------------------------------------*/
3027 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
3030 char udev_cookie[DM_COOKIE_LENGTH];
3031 char *envp[] = { udev_cookie, NULL };
3034 return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
3036 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
3037 DM_COOKIE_ENV_VAR_NAME, cookie);
3038 return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
3043 uint32_t dm_next_uevent_seq(struct mapped_device *md)
3045 return atomic_add_return(1, &md->uevent_seq);
3048 uint32_t dm_get_event_nr(struct mapped_device *md)
3050 return atomic_read(&md->event_nr);
3053 int dm_wait_event(struct mapped_device *md, int event_nr)
3055 return wait_event_interruptible(md->eventq,
3056 (event_nr != atomic_read(&md->event_nr)));
3059 void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
3061 unsigned long flags;
3063 spin_lock_irqsave(&md->uevent_lock, flags);
3064 list_add(elist, &md->uevent_list);
3065 spin_unlock_irqrestore(&md->uevent_lock, flags);
3069 * The gendisk is only valid as long as you have a reference
3072 struct gendisk *dm_disk(struct mapped_device *md)
3077 struct kobject *dm_kobject(struct mapped_device *md)
3079 return &md->kobj_holder.kobj;
3082 struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
3084 struct mapped_device *md;
3086 md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
3088 if (test_bit(DMF_FREEING, &md->flags) ||
3096 int dm_suspended_md(struct mapped_device *md)
3098 return test_bit(DMF_SUSPENDED, &md->flags);
3101 int dm_suspended_internally_md(struct mapped_device *md)
3103 return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
3106 int dm_test_deferred_remove_flag(struct mapped_device *md)
3108 return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
3111 int dm_suspended(struct dm_target *ti)
3113 return dm_suspended_md(dm_table_get_md(ti->table));
3115 EXPORT_SYMBOL_GPL(dm_suspended);
3117 int dm_noflush_suspending(struct dm_target *ti)
3119 return __noflush_suspending(dm_table_get_md(ti->table));
3121 EXPORT_SYMBOL_GPL(dm_noflush_suspending);
3123 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, unsigned per_bio_data_size)
3125 struct dm_md_mempools *pools = kzalloc(sizeof(*pools), GFP_KERNEL);
3126 struct kmem_cache *cachep;
3127 unsigned int pool_size;
3128 unsigned int front_pad;
3133 if (type == DM_TYPE_BIO_BASED) {
3135 pool_size = dm_get_reserved_bio_based_ios();
3136 front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
3137 } else if (type == DM_TYPE_REQUEST_BASED) {
3138 cachep = _rq_tio_cache;
3139 pool_size = dm_get_reserved_rq_based_ios();
3140 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
3141 /* per_bio_data_size is not used. See __bind_mempools(). */
3142 WARN_ON(per_bio_data_size != 0);
3146 pools->io_pool = mempool_create_slab_pool(pool_size, cachep);
3147 if (!pools->io_pool)
3150 pools->bs = bioset_create_nobvec(pool_size, front_pad);
3154 if (integrity && bioset_integrity_create(pools->bs, pool_size))
3160 dm_free_md_mempools(pools);
3165 void dm_free_md_mempools(struct dm_md_mempools *pools)
3171 mempool_destroy(pools->io_pool);
3174 bioset_free(pools->bs);
3179 static const struct block_device_operations dm_blk_dops = {
3180 .open = dm_blk_open,
3181 .release = dm_blk_close,
3182 .ioctl = dm_blk_ioctl,
3183 .getgeo = dm_blk_getgeo,
3184 .owner = THIS_MODULE
3190 module_init(dm_init);
3191 module_exit(dm_exit);
3193 module_param(major, uint, 0);
3194 MODULE_PARM_DESC(major, "The major number of the device mapper");
3196 module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
3197 MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
3199 module_param(reserved_rq_based_ios, uint, S_IRUGO | S_IWUSR);
3200 MODULE_PARM_DESC(reserved_rq_based_ios, "Reserved IOs in request-based mempools");
3202 MODULE_DESCRIPTION(DM_NAME " driver");
3203 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3204 MODULE_LICENSE("GPL");