2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This file is released under the GPL.
10 #include "dm-uevent.h"
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/sched/signal.h>
16 #include <linux/blkpg.h>
17 #include <linux/bio.h>
18 #include <linux/mempool.h>
19 #include <linux/dax.h>
20 #include <linux/slab.h>
21 #include <linux/idr.h>
22 #include <linux/uio.h>
23 #include <linux/hdreg.h>
24 #include <linux/delay.h>
25 #include <linux/wait.h>
27 #include <linux/refcount.h>
29 #define DM_MSG_PREFIX "core"
32 * Cookies are numeric values sent with CHANGE and REMOVE
33 * uevents while resuming, removing or renaming the device.
35 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
36 #define DM_COOKIE_LENGTH 24
38 static const char *_name = DM_NAME;
40 static unsigned int major = 0;
41 static unsigned int _major = 0;
43 static DEFINE_IDR(_minor_idr);
45 static DEFINE_SPINLOCK(_minor_lock);
47 static void do_deferred_remove(struct work_struct *w);
49 static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
51 static struct workqueue_struct *deferred_remove_workqueue;
53 atomic_t dm_global_event_nr = ATOMIC_INIT(0);
54 DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq);
56 void dm_issue_global_event(void)
58 atomic_inc(&dm_global_event_nr);
59 wake_up(&dm_global_eventq);
63 * One of these is allocated (on-stack) per original bio.
70 unsigned sector_count;
74 * One of these is allocated per clone bio.
76 #define DM_TIO_MAGIC 7282014
81 unsigned target_bio_nr;
88 * One of these is allocated per original bio.
89 * It contains the first clone used for that original.
91 #define DM_IO_MAGIC 5191977
94 struct mapped_device *md;
98 unsigned long start_time;
99 spinlock_t endio_lock;
100 struct dm_stats_aux stats_aux;
101 /* last member of dm_target_io is 'struct bio' */
102 struct dm_target_io tio;
105 void *dm_per_bio_data(struct bio *bio, size_t data_size)
107 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
108 if (!tio->inside_dm_io)
109 return (char *)bio - offsetof(struct dm_target_io, clone) - data_size;
110 return (char *)bio - offsetof(struct dm_target_io, clone) - offsetof(struct dm_io, tio) - data_size;
112 EXPORT_SYMBOL_GPL(dm_per_bio_data);
114 struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size)
116 struct dm_io *io = (struct dm_io *)((char *)data + data_size);
117 if (io->magic == DM_IO_MAGIC)
118 return (struct bio *)((char *)io + offsetof(struct dm_io, tio) + offsetof(struct dm_target_io, clone));
119 BUG_ON(io->magic != DM_TIO_MAGIC);
120 return (struct bio *)((char *)io + offsetof(struct dm_target_io, clone));
122 EXPORT_SYMBOL_GPL(dm_bio_from_per_bio_data);
124 unsigned dm_bio_get_target_bio_nr(const struct bio *bio)
126 return container_of(bio, struct dm_target_io, clone)->target_bio_nr;
128 EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr);
130 #define MINOR_ALLOCED ((void *)-1)
133 * Bits for the md->flags field.
135 #define DMF_BLOCK_IO_FOR_SUSPEND 0
136 #define DMF_SUSPENDED 1
138 #define DMF_FREEING 3
139 #define DMF_DELETING 4
140 #define DMF_NOFLUSH_SUSPENDING 5
141 #define DMF_DEFERRED_REMOVE 6
142 #define DMF_SUSPENDED_INTERNALLY 7
144 #define DM_NUMA_NODE NUMA_NO_NODE
145 static int dm_numa_node = DM_NUMA_NODE;
148 * For mempools pre-allocation at the table loading time.
150 struct dm_md_mempools {
152 struct bio_set io_bs;
155 struct table_device {
156 struct list_head list;
158 struct dm_dev dm_dev;
161 static struct kmem_cache *_rq_tio_cache;
162 static struct kmem_cache *_rq_cache;
165 * Bio-based DM's mempools' reserved IOs set by the user.
167 #define RESERVED_BIO_BASED_IOS 16
168 static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
170 static int __dm_get_module_param_int(int *module_param, int min, int max)
172 int param = READ_ONCE(*module_param);
173 int modified_param = 0;
174 bool modified = true;
177 modified_param = min;
178 else if (param > max)
179 modified_param = max;
184 (void)cmpxchg(module_param, param, modified_param);
185 param = modified_param;
191 unsigned __dm_get_module_param(unsigned *module_param,
192 unsigned def, unsigned max)
194 unsigned param = READ_ONCE(*module_param);
195 unsigned modified_param = 0;
198 modified_param = def;
199 else if (param > max)
200 modified_param = max;
202 if (modified_param) {
203 (void)cmpxchg(module_param, param, modified_param);
204 param = modified_param;
210 unsigned dm_get_reserved_bio_based_ios(void)
212 return __dm_get_module_param(&reserved_bio_based_ios,
213 RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS);
215 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
217 static unsigned dm_get_numa_node(void)
219 return __dm_get_module_param_int(&dm_numa_node,
220 DM_NUMA_NODE, num_online_nodes() - 1);
223 static int __init local_init(void)
227 _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
231 _rq_cache = kmem_cache_create("dm_old_clone_request", sizeof(struct request),
232 __alignof__(struct request), 0, NULL);
234 goto out_free_rq_tio_cache;
236 r = dm_uevent_init();
238 goto out_free_rq_cache;
240 deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
241 if (!deferred_remove_workqueue) {
243 goto out_uevent_exit;
247 r = register_blkdev(_major, _name);
249 goto out_free_workqueue;
257 destroy_workqueue(deferred_remove_workqueue);
261 kmem_cache_destroy(_rq_cache);
262 out_free_rq_tio_cache:
263 kmem_cache_destroy(_rq_tio_cache);
268 static void local_exit(void)
270 flush_scheduled_work();
271 destroy_workqueue(deferred_remove_workqueue);
273 kmem_cache_destroy(_rq_cache);
274 kmem_cache_destroy(_rq_tio_cache);
275 unregister_blkdev(_major, _name);
280 DMINFO("cleaned up");
283 static int (*_inits[])(void) __initdata = {
294 static void (*_exits[])(void) = {
305 static int __init dm_init(void)
307 const int count = ARRAY_SIZE(_inits);
311 for (i = 0; i < count; i++) {
326 static void __exit dm_exit(void)
328 int i = ARRAY_SIZE(_exits);
334 * Should be empty by this point.
336 idr_destroy(&_minor_idr);
340 * Block device functions
342 int dm_deleting_md(struct mapped_device *md)
344 return test_bit(DMF_DELETING, &md->flags);
347 static int dm_blk_open(struct block_device *bdev, fmode_t mode)
349 struct mapped_device *md;
351 spin_lock(&_minor_lock);
353 md = bdev->bd_disk->private_data;
357 if (test_bit(DMF_FREEING, &md->flags) ||
358 dm_deleting_md(md)) {
364 atomic_inc(&md->open_count);
366 spin_unlock(&_minor_lock);
368 return md ? 0 : -ENXIO;
371 static void dm_blk_close(struct gendisk *disk, fmode_t mode)
373 struct mapped_device *md;
375 spin_lock(&_minor_lock);
377 md = disk->private_data;
381 if (atomic_dec_and_test(&md->open_count) &&
382 (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
383 queue_work(deferred_remove_workqueue, &deferred_remove_work);
387 spin_unlock(&_minor_lock);
390 int dm_open_count(struct mapped_device *md)
392 return atomic_read(&md->open_count);
396 * Guarantees nothing is using the device before it's deleted.
398 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
402 spin_lock(&_minor_lock);
404 if (dm_open_count(md)) {
407 set_bit(DMF_DEFERRED_REMOVE, &md->flags);
408 } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
411 set_bit(DMF_DELETING, &md->flags);
413 spin_unlock(&_minor_lock);
418 int dm_cancel_deferred_remove(struct mapped_device *md)
422 spin_lock(&_minor_lock);
424 if (test_bit(DMF_DELETING, &md->flags))
427 clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
429 spin_unlock(&_minor_lock);
434 static void do_deferred_remove(struct work_struct *w)
436 dm_deferred_remove();
439 sector_t dm_get_size(struct mapped_device *md)
441 return get_capacity(md->disk);
444 struct request_queue *dm_get_md_queue(struct mapped_device *md)
449 struct dm_stats *dm_get_stats(struct mapped_device *md)
454 static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
456 struct mapped_device *md = bdev->bd_disk->private_data;
458 return dm_get_geometry(md, geo);
461 static int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
462 struct blk_zone *zones, unsigned int *nr_zones,
465 #ifdef CONFIG_BLK_DEV_ZONED
466 struct mapped_device *md = disk->private_data;
467 struct dm_target *tgt;
468 struct dm_table *map;
471 if (dm_suspended_md(md))
474 map = dm_get_live_table(md, &srcu_idx);
478 tgt = dm_table_find_target(map, sector);
479 if (!dm_target_is_valid(tgt)) {
485 * If we are executing this, we already know that the block device
486 * is a zoned device and so each target should have support for that
487 * type of drive. A missing report_zones method means that the target
488 * driver has a problem.
490 if (WARN_ON(!tgt->type->report_zones)) {
496 * blkdev_report_zones() will loop and call this again to cover all the
497 * zones of the target, eventually moving on to the next target.
498 * So there is no need to loop here trying to fill the entire array
501 ret = tgt->type->report_zones(tgt, sector, zones,
505 dm_put_live_table(md, srcu_idx);
512 static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx,
513 struct block_device **bdev)
514 __acquires(md->io_barrier)
516 struct dm_target *tgt;
517 struct dm_table *map;
522 map = dm_get_live_table(md, srcu_idx);
523 if (!map || !dm_table_get_size(map))
526 /* We only support devices that have a single target */
527 if (dm_table_get_num_targets(map) != 1)
530 tgt = dm_table_get_target(map, 0);
531 if (!tgt->type->prepare_ioctl)
534 if (dm_suspended_md(md))
537 r = tgt->type->prepare_ioctl(tgt, bdev);
538 if (r == -ENOTCONN && !fatal_signal_pending(current)) {
539 dm_put_live_table(md, *srcu_idx);
547 static void dm_unprepare_ioctl(struct mapped_device *md, int srcu_idx)
548 __releases(md->io_barrier)
550 dm_put_live_table(md, srcu_idx);
553 static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
554 unsigned int cmd, unsigned long arg)
556 struct mapped_device *md = bdev->bd_disk->private_data;
559 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
565 * Target determined this ioctl is being issued against a
566 * subset of the parent bdev; require extra privileges.
568 if (!capable(CAP_SYS_RAWIO)) {
570 "%s: sending ioctl %x to DM device without required privilege.",
577 r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
579 dm_unprepare_ioctl(md, srcu_idx);
583 static void start_io_acct(struct dm_io *io);
585 static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio)
588 struct dm_target_io *tio;
591 clone = bio_alloc_bioset(GFP_NOIO, 0, &md->io_bs);
595 tio = container_of(clone, struct dm_target_io, clone);
596 tio->inside_dm_io = true;
599 io = container_of(tio, struct dm_io, tio);
600 io->magic = DM_IO_MAGIC;
602 atomic_set(&io->io_count, 1);
605 spin_lock_init(&io->endio_lock);
612 static void free_io(struct mapped_device *md, struct dm_io *io)
614 bio_put(&io->tio.clone);
617 static struct dm_target_io *alloc_tio(struct clone_info *ci, struct dm_target *ti,
618 unsigned target_bio_nr, gfp_t gfp_mask)
620 struct dm_target_io *tio;
622 if (!ci->io->tio.io) {
623 /* the dm_target_io embedded in ci->io is available */
626 struct bio *clone = bio_alloc_bioset(gfp_mask, 0, &ci->io->md->bs);
630 tio = container_of(clone, struct dm_target_io, clone);
631 tio->inside_dm_io = false;
634 tio->magic = DM_TIO_MAGIC;
637 tio->target_bio_nr = target_bio_nr;
642 static void free_tio(struct dm_target_io *tio)
644 if (tio->inside_dm_io)
646 bio_put(&tio->clone);
649 static bool md_in_flight_bios(struct mapped_device *md)
652 struct hd_struct *part = &dm_disk(md)->part0;
655 for_each_possible_cpu(cpu) {
656 sum += part_stat_local_read_cpu(part, in_flight[0], cpu);
657 sum += part_stat_local_read_cpu(part, in_flight[1], cpu);
663 static bool md_in_flight(struct mapped_device *md)
665 if (queue_is_mq(md->queue))
666 return blk_mq_queue_inflight(md->queue);
668 return md_in_flight_bios(md);
671 static void start_io_acct(struct dm_io *io)
673 struct mapped_device *md = io->md;
674 struct bio *bio = io->orig_bio;
676 io->start_time = jiffies;
678 generic_start_io_acct(md->queue, bio_op(bio), bio_sectors(bio),
679 &dm_disk(md)->part0);
681 if (unlikely(dm_stats_used(&md->stats)))
682 dm_stats_account_io(&md->stats, bio_data_dir(bio),
683 bio->bi_iter.bi_sector, bio_sectors(bio),
684 false, 0, &io->stats_aux);
687 static void end_io_acct(struct dm_io *io)
689 struct mapped_device *md = io->md;
690 struct bio *bio = io->orig_bio;
691 unsigned long duration = jiffies - io->start_time;
693 generic_end_io_acct(md->queue, bio_op(bio), &dm_disk(md)->part0,
696 if (unlikely(dm_stats_used(&md->stats)))
697 dm_stats_account_io(&md->stats, bio_data_dir(bio),
698 bio->bi_iter.bi_sector, bio_sectors(bio),
699 true, duration, &io->stats_aux);
701 /* nudge anyone waiting on suspend queue */
702 if (unlikely(waitqueue_active(&md->wait)))
707 * Add the bio to the list of deferred io.
709 static void queue_io(struct mapped_device *md, struct bio *bio)
713 spin_lock_irqsave(&md->deferred_lock, flags);
714 bio_list_add(&md->deferred, bio);
715 spin_unlock_irqrestore(&md->deferred_lock, flags);
716 queue_work(md->wq, &md->work);
720 * Everyone (including functions in this file), should use this
721 * function to access the md->map field, and make sure they call
722 * dm_put_live_table() when finished.
724 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
726 *srcu_idx = srcu_read_lock(&md->io_barrier);
728 return srcu_dereference(md->map, &md->io_barrier);
731 void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
733 srcu_read_unlock(&md->io_barrier, srcu_idx);
736 void dm_sync_table(struct mapped_device *md)
738 synchronize_srcu(&md->io_barrier);
739 synchronize_rcu_expedited();
743 * A fast alternative to dm_get_live_table/dm_put_live_table.
744 * The caller must not block between these two functions.
746 static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
749 return rcu_dereference(md->map);
752 static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
757 static char *_dm_claim_ptr = "I belong to device-mapper";
760 * Open a table device so we can use it as a map destination.
762 static int open_table_device(struct table_device *td, dev_t dev,
763 struct mapped_device *md)
765 struct block_device *bdev;
769 BUG_ON(td->dm_dev.bdev);
771 bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr);
773 return PTR_ERR(bdev);
775 r = bd_link_disk_holder(bdev, dm_disk(md));
777 blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
781 td->dm_dev.bdev = bdev;
782 td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
787 * Close a table device that we've been using.
789 static void close_table_device(struct table_device *td, struct mapped_device *md)
791 if (!td->dm_dev.bdev)
794 bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
795 blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
796 put_dax(td->dm_dev.dax_dev);
797 td->dm_dev.bdev = NULL;
798 td->dm_dev.dax_dev = NULL;
801 static struct table_device *find_table_device(struct list_head *l, dev_t dev,
803 struct table_device *td;
805 list_for_each_entry(td, l, list)
806 if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
812 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
813 struct dm_dev **result) {
815 struct table_device *td;
817 mutex_lock(&md->table_devices_lock);
818 td = find_table_device(&md->table_devices, dev, mode);
820 td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
822 mutex_unlock(&md->table_devices_lock);
826 td->dm_dev.mode = mode;
827 td->dm_dev.bdev = NULL;
829 if ((r = open_table_device(td, dev, md))) {
830 mutex_unlock(&md->table_devices_lock);
835 format_dev_t(td->dm_dev.name, dev);
837 refcount_set(&td->count, 1);
838 list_add(&td->list, &md->table_devices);
840 refcount_inc(&td->count);
842 mutex_unlock(&md->table_devices_lock);
844 *result = &td->dm_dev;
847 EXPORT_SYMBOL_GPL(dm_get_table_device);
849 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
851 struct table_device *td = container_of(d, struct table_device, dm_dev);
853 mutex_lock(&md->table_devices_lock);
854 if (refcount_dec_and_test(&td->count)) {
855 close_table_device(td, md);
859 mutex_unlock(&md->table_devices_lock);
861 EXPORT_SYMBOL(dm_put_table_device);
863 static void free_table_devices(struct list_head *devices)
865 struct list_head *tmp, *next;
867 list_for_each_safe(tmp, next, devices) {
868 struct table_device *td = list_entry(tmp, struct table_device, list);
870 DMWARN("dm_destroy: %s still exists with %d references",
871 td->dm_dev.name, refcount_read(&td->count));
877 * Get the geometry associated with a dm device
879 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
887 * Set the geometry of a device.
889 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
891 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
893 if (geo->start > sz) {
894 DMWARN("Start sector is beyond the geometry limits.");
903 static int __noflush_suspending(struct mapped_device *md)
905 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
909 * Decrements the number of outstanding ios that a bio has been
910 * cloned into, completing the original io if necc.
912 static void dec_pending(struct dm_io *io, blk_status_t error)
915 blk_status_t io_error;
917 struct mapped_device *md = io->md;
919 /* Push-back supersedes any I/O errors */
920 if (unlikely(error)) {
921 spin_lock_irqsave(&io->endio_lock, flags);
922 if (!(io->status == BLK_STS_DM_REQUEUE && __noflush_suspending(md)))
924 spin_unlock_irqrestore(&io->endio_lock, flags);
927 if (atomic_dec_and_test(&io->io_count)) {
928 if (io->status == BLK_STS_DM_REQUEUE) {
930 * Target requested pushing back the I/O.
932 spin_lock_irqsave(&md->deferred_lock, flags);
933 if (__noflush_suspending(md))
934 /* NOTE early return due to BLK_STS_DM_REQUEUE below */
935 bio_list_add_head(&md->deferred, io->orig_bio);
937 /* noflush suspend was interrupted. */
938 io->status = BLK_STS_IOERR;
939 spin_unlock_irqrestore(&md->deferred_lock, flags);
942 io_error = io->status;
947 if (io_error == BLK_STS_DM_REQUEUE)
950 if ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size) {
952 * Preflush done for flush with data, reissue
953 * without REQ_PREFLUSH.
955 bio->bi_opf &= ~REQ_PREFLUSH;
958 /* done with normal IO or empty flush */
960 bio->bi_status = io_error;
966 void disable_write_same(struct mapped_device *md)
968 struct queue_limits *limits = dm_get_queue_limits(md);
970 /* device doesn't really support WRITE SAME, disable it */
971 limits->max_write_same_sectors = 0;
974 void disable_write_zeroes(struct mapped_device *md)
976 struct queue_limits *limits = dm_get_queue_limits(md);
978 /* device doesn't really support WRITE ZEROES, disable it */
979 limits->max_write_zeroes_sectors = 0;
982 static void clone_endio(struct bio *bio)
984 blk_status_t error = bio->bi_status;
985 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
986 struct dm_io *io = tio->io;
987 struct mapped_device *md = tio->io->md;
988 dm_endio_fn endio = tio->ti->type->end_io;
990 if (unlikely(error == BLK_STS_TARGET) && md->type != DM_TYPE_NVME_BIO_BASED) {
991 if (bio_op(bio) == REQ_OP_WRITE_SAME &&
992 !bio->bi_disk->queue->limits.max_write_same_sectors)
993 disable_write_same(md);
994 if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
995 !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
996 disable_write_zeroes(md);
1000 int r = endio(tio->ti, bio, &error);
1002 case DM_ENDIO_REQUEUE:
1003 error = BLK_STS_DM_REQUEUE;
1007 case DM_ENDIO_INCOMPLETE:
1008 /* The target will handle the io */
1011 DMWARN("unimplemented target endio return value: %d", r);
1017 dec_pending(io, error);
1021 * Return maximum size of I/O possible at the supplied sector up to the current
1024 static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
1026 sector_t target_offset = dm_target_offset(ti, sector);
1028 return ti->len - target_offset;
1031 static sector_t max_io_len(sector_t sector, struct dm_target *ti)
1033 sector_t len = max_io_len_target_boundary(sector, ti);
1034 sector_t offset, max_len;
1037 * Does the target need to split even further?
1039 if (ti->max_io_len) {
1040 offset = dm_target_offset(ti, sector);
1041 if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
1042 max_len = sector_div(offset, ti->max_io_len);
1044 max_len = offset & (ti->max_io_len - 1);
1045 max_len = ti->max_io_len - max_len;
1054 int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
1056 if (len > UINT_MAX) {
1057 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1058 (unsigned long long)len, UINT_MAX);
1059 ti->error = "Maximum size of target IO is too large";
1064 * BIO based queue uses its own splitting. When multipage bvecs
1065 * is switched on, size of the incoming bio may be too big to
1066 * be handled in some targets, such as crypt.
1068 * When these targets are ready for the big bio, we can remove
1071 ti->max_io_len = min_t(uint32_t, len, BIO_MAX_PAGES * PAGE_SIZE);
1075 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
1077 static struct dm_target *dm_dax_get_live_target(struct mapped_device *md,
1078 sector_t sector, int *srcu_idx)
1079 __acquires(md->io_barrier)
1081 struct dm_table *map;
1082 struct dm_target *ti;
1084 map = dm_get_live_table(md, srcu_idx);
1088 ti = dm_table_find_target(map, sector);
1089 if (!dm_target_is_valid(ti))
1095 static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
1096 long nr_pages, void **kaddr, pfn_t *pfn)
1098 struct mapped_device *md = dax_get_private(dax_dev);
1099 sector_t sector = pgoff * PAGE_SECTORS;
1100 struct dm_target *ti;
1101 long len, ret = -EIO;
1104 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1108 if (!ti->type->direct_access)
1110 len = max_io_len(sector, ti) / PAGE_SECTORS;
1113 nr_pages = min(len, nr_pages);
1114 ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn);
1117 dm_put_live_table(md, srcu_idx);
1122 static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
1123 void *addr, size_t bytes, struct iov_iter *i)
1125 struct mapped_device *md = dax_get_private(dax_dev);
1126 sector_t sector = pgoff * PAGE_SECTORS;
1127 struct dm_target *ti;
1131 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1135 if (!ti->type->dax_copy_from_iter) {
1136 ret = copy_from_iter(addr, bytes, i);
1139 ret = ti->type->dax_copy_from_iter(ti, pgoff, addr, bytes, i);
1141 dm_put_live_table(md, srcu_idx);
1146 static size_t dm_dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
1147 void *addr, size_t bytes, struct iov_iter *i)
1149 struct mapped_device *md = dax_get_private(dax_dev);
1150 sector_t sector = pgoff * PAGE_SECTORS;
1151 struct dm_target *ti;
1155 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1159 if (!ti->type->dax_copy_to_iter) {
1160 ret = copy_to_iter(addr, bytes, i);
1163 ret = ti->type->dax_copy_to_iter(ti, pgoff, addr, bytes, i);
1165 dm_put_live_table(md, srcu_idx);
1171 * A target may call dm_accept_partial_bio only from the map routine. It is
1172 * allowed for all bio types except REQ_PREFLUSH and REQ_OP_ZONE_RESET.
1174 * dm_accept_partial_bio informs the dm that the target only wants to process
1175 * additional n_sectors sectors of the bio and the rest of the data should be
1176 * sent in a next bio.
1178 * A diagram that explains the arithmetics:
1179 * +--------------------+---------------+-------+
1181 * +--------------------+---------------+-------+
1183 * <-------------- *tio->len_ptr --------------->
1184 * <------- bi_size ------->
1187 * Region 1 was already iterated over with bio_advance or similar function.
1188 * (it may be empty if the target doesn't use bio_advance)
1189 * Region 2 is the remaining bio size that the target wants to process.
1190 * (it may be empty if region 1 is non-empty, although there is no reason
1192 * The target requires that region 3 is to be sent in the next bio.
1194 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1195 * the partially processed part (the sum of regions 1+2) must be the same for all
1196 * copies of the bio.
1198 void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
1200 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1201 unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
1202 BUG_ON(bio->bi_opf & REQ_PREFLUSH);
1203 BUG_ON(bi_size > *tio->len_ptr);
1204 BUG_ON(n_sectors > bi_size);
1205 *tio->len_ptr -= bi_size - n_sectors;
1206 bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
1208 EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
1211 * The zone descriptors obtained with a zone report indicate
1212 * zone positions within the underlying device of the target. The zone
1213 * descriptors must be remapped to match their position within the dm device.
1214 * The caller target should obtain the zones information using
1215 * blkdev_report_zones() to ensure that remapping for partition offset is
1218 void dm_remap_zone_report(struct dm_target *ti, sector_t start,
1219 struct blk_zone *zones, unsigned int *nr_zones)
1221 #ifdef CONFIG_BLK_DEV_ZONED
1222 struct blk_zone *zone;
1223 unsigned int nrz = *nr_zones;
1227 * Remap the start sector and write pointer position of the zones in
1228 * the array. Since we may have obtained from the target underlying
1229 * device more zones that the target size, also adjust the number
1232 for (i = 0; i < nrz; i++) {
1234 if (zone->start >= start + ti->len) {
1235 memset(zone, 0, sizeof(struct blk_zone) * (nrz - i));
1239 zone->start = zone->start + ti->begin - start;
1240 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
1243 if (zone->cond == BLK_ZONE_COND_FULL)
1244 zone->wp = zone->start + zone->len;
1245 else if (zone->cond == BLK_ZONE_COND_EMPTY)
1246 zone->wp = zone->start;
1248 zone->wp = zone->wp + ti->begin - start;
1252 #else /* !CONFIG_BLK_DEV_ZONED */
1256 EXPORT_SYMBOL_GPL(dm_remap_zone_report);
1258 static blk_qc_t __map_bio(struct dm_target_io *tio)
1262 struct bio *clone = &tio->clone;
1263 struct dm_io *io = tio->io;
1264 struct mapped_device *md = io->md;
1265 struct dm_target *ti = tio->ti;
1266 blk_qc_t ret = BLK_QC_T_NONE;
1268 clone->bi_end_io = clone_endio;
1271 * Map the clone. If r == 0 we don't need to do
1272 * anything, the target has assumed ownership of
1275 atomic_inc(&io->io_count);
1276 sector = clone->bi_iter.bi_sector;
1278 r = ti->type->map(ti, clone);
1280 case DM_MAPIO_SUBMITTED:
1282 case DM_MAPIO_REMAPPED:
1283 /* the bio has been remapped so dispatch it */
1284 trace_block_bio_remap(clone->bi_disk->queue, clone,
1285 bio_dev(io->orig_bio), sector);
1286 if (md->type == DM_TYPE_NVME_BIO_BASED)
1287 ret = direct_make_request(clone);
1289 ret = generic_make_request(clone);
1293 dec_pending(io, BLK_STS_IOERR);
1295 case DM_MAPIO_REQUEUE:
1297 dec_pending(io, BLK_STS_DM_REQUEUE);
1300 DMWARN("unimplemented target map return value: %d", r);
1307 static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
1309 bio->bi_iter.bi_sector = sector;
1310 bio->bi_iter.bi_size = to_bytes(len);
1314 * Creates a bio that consists of range of complete bvecs.
1316 static int clone_bio(struct dm_target_io *tio, struct bio *bio,
1317 sector_t sector, unsigned len)
1319 struct bio *clone = &tio->clone;
1321 __bio_clone_fast(clone, bio);
1323 if (bio_integrity(bio)) {
1326 if (unlikely(!dm_target_has_integrity(tio->ti->type) &&
1327 !dm_target_passes_integrity(tio->ti->type))) {
1328 DMWARN("%s: the target %s doesn't support integrity data.",
1329 dm_device_name(tio->io->md),
1330 tio->ti->type->name);
1334 r = bio_integrity_clone(clone, bio, GFP_NOIO);
1339 bio_trim(clone, sector - clone->bi_iter.bi_sector, len);
1344 static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci,
1345 struct dm_target *ti, unsigned num_bios)
1347 struct dm_target_io *tio;
1353 if (num_bios == 1) {
1354 tio = alloc_tio(ci, ti, 0, GFP_NOIO);
1355 bio_list_add(blist, &tio->clone);
1359 for (try = 0; try < 2; try++) {
1364 mutex_lock(&ci->io->md->table_devices_lock);
1365 for (bio_nr = 0; bio_nr < num_bios; bio_nr++) {
1366 tio = alloc_tio(ci, ti, bio_nr, try ? GFP_NOIO : GFP_NOWAIT);
1370 bio_list_add(blist, &tio->clone);
1373 mutex_unlock(&ci->io->md->table_devices_lock);
1374 if (bio_nr == num_bios)
1377 while ((bio = bio_list_pop(blist))) {
1378 tio = container_of(bio, struct dm_target_io, clone);
1384 static blk_qc_t __clone_and_map_simple_bio(struct clone_info *ci,
1385 struct dm_target_io *tio, unsigned *len)
1387 struct bio *clone = &tio->clone;
1391 __bio_clone_fast(clone, ci->bio);
1393 bio_setup_sector(clone, ci->sector, *len);
1395 return __map_bio(tio);
1398 static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
1399 unsigned num_bios, unsigned *len)
1401 struct bio_list blist = BIO_EMPTY_LIST;
1403 struct dm_target_io *tio;
1405 alloc_multiple_bios(&blist, ci, ti, num_bios);
1407 while ((bio = bio_list_pop(&blist))) {
1408 tio = container_of(bio, struct dm_target_io, clone);
1409 (void) __clone_and_map_simple_bio(ci, tio, len);
1413 static int __send_empty_flush(struct clone_info *ci)
1415 unsigned target_nr = 0;
1416 struct dm_target *ti;
1419 * Empty flush uses a statically initialized bio, as the base for
1420 * cloning. However, blkg association requires that a bdev is
1421 * associated with a gendisk, which doesn't happen until the bdev is
1422 * opened. So, blkg association is done at issue time of the flush
1423 * rather than when the device is created in alloc_dev().
1425 bio_set_dev(ci->bio, ci->io->md->bdev);
1427 BUG_ON(bio_has_data(ci->bio));
1428 while ((ti = dm_table_get_target(ci->map, target_nr++)))
1429 __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
1431 bio_disassociate_blkg(ci->bio);
1436 static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
1437 sector_t sector, unsigned *len)
1439 struct bio *bio = ci->bio;
1440 struct dm_target_io *tio;
1443 tio = alloc_tio(ci, ti, 0, GFP_NOIO);
1445 r = clone_bio(tio, bio, sector, *len);
1450 (void) __map_bio(tio);
1455 typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
1457 static unsigned get_num_discard_bios(struct dm_target *ti)
1459 return ti->num_discard_bios;
1462 static unsigned get_num_secure_erase_bios(struct dm_target *ti)
1464 return ti->num_secure_erase_bios;
1467 static unsigned get_num_write_same_bios(struct dm_target *ti)
1469 return ti->num_write_same_bios;
1472 static unsigned get_num_write_zeroes_bios(struct dm_target *ti)
1474 return ti->num_write_zeroes_bios;
1477 typedef bool (*is_split_required_fn)(struct dm_target *ti);
1479 static bool is_split_required_for_discard(struct dm_target *ti)
1481 return ti->split_discard_bios;
1484 static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti,
1485 unsigned num_bios, bool is_split_required)
1490 * Even though the device advertised support for this type of
1491 * request, that does not mean every target supports it, and
1492 * reconfiguration might also have changed that since the
1493 * check was performed.
1498 if (!is_split_required)
1499 len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
1501 len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
1503 __send_duplicate_bios(ci, ti, num_bios, &len);
1506 ci->sector_count -= len;
1511 static int __send_discard(struct clone_info *ci, struct dm_target *ti)
1513 return __send_changing_extent_only(ci, ti, get_num_discard_bios(ti),
1514 is_split_required_for_discard(ti));
1517 static int __send_secure_erase(struct clone_info *ci, struct dm_target *ti)
1519 return __send_changing_extent_only(ci, ti, get_num_secure_erase_bios(ti), false);
1522 static int __send_write_same(struct clone_info *ci, struct dm_target *ti)
1524 return __send_changing_extent_only(ci, ti, get_num_write_same_bios(ti), false);
1527 static int __send_write_zeroes(struct clone_info *ci, struct dm_target *ti)
1529 return __send_changing_extent_only(ci, ti, get_num_write_zeroes_bios(ti), false);
1532 static bool __process_abnormal_io(struct clone_info *ci, struct dm_target *ti,
1535 struct bio *bio = ci->bio;
1537 if (bio_op(bio) == REQ_OP_DISCARD)
1538 *result = __send_discard(ci, ti);
1539 else if (bio_op(bio) == REQ_OP_SECURE_ERASE)
1540 *result = __send_secure_erase(ci, ti);
1541 else if (bio_op(bio) == REQ_OP_WRITE_SAME)
1542 *result = __send_write_same(ci, ti);
1543 else if (bio_op(bio) == REQ_OP_WRITE_ZEROES)
1544 *result = __send_write_zeroes(ci, ti);
1552 * Select the correct strategy for processing a non-flush bio.
1554 static int __split_and_process_non_flush(struct clone_info *ci)
1556 struct dm_target *ti;
1560 ti = dm_table_find_target(ci->map, ci->sector);
1561 if (!dm_target_is_valid(ti))
1564 if (unlikely(__process_abnormal_io(ci, ti, &r)))
1567 len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count);
1569 r = __clone_and_map_data_bio(ci, ti, ci->sector, &len);
1574 ci->sector_count -= len;
1579 static void init_clone_info(struct clone_info *ci, struct mapped_device *md,
1580 struct dm_table *map, struct bio *bio)
1583 ci->io = alloc_io(md, bio);
1584 ci->sector = bio->bi_iter.bi_sector;
1587 #define __dm_part_stat_sub(part, field, subnd) \
1588 (part_stat_get(part, field) -= (subnd))
1591 * Entry point to split a bio into clones and submit them to the targets.
1593 static blk_qc_t __split_and_process_bio(struct mapped_device *md,
1594 struct dm_table *map, struct bio *bio)
1596 struct clone_info ci;
1597 blk_qc_t ret = BLK_QC_T_NONE;
1600 if (unlikely(!map)) {
1605 blk_queue_split(md->queue, &bio);
1607 init_clone_info(&ci, md, map, bio);
1609 if (bio->bi_opf & REQ_PREFLUSH) {
1610 struct bio flush_bio;
1613 * Use an on-stack bio for this, it's safe since we don't
1614 * need to reference it after submit. It's just used as
1615 * the basis for the clone(s).
1617 bio_init(&flush_bio, NULL, 0);
1618 flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
1619 ci.bio = &flush_bio;
1620 ci.sector_count = 0;
1621 error = __send_empty_flush(&ci);
1622 /* dec_pending submits any data associated with flush */
1623 } else if (bio_op(bio) == REQ_OP_ZONE_RESET) {
1625 ci.sector_count = 0;
1626 error = __split_and_process_non_flush(&ci);
1629 ci.sector_count = bio_sectors(bio);
1630 while (ci.sector_count && !error) {
1631 error = __split_and_process_non_flush(&ci);
1632 if (current->bio_list && ci.sector_count && !error) {
1634 * Remainder must be passed to generic_make_request()
1635 * so that it gets handled *after* bios already submitted
1636 * have been completely processed.
1637 * We take a clone of the original to store in
1638 * ci.io->orig_bio to be used by end_io_acct() and
1639 * for dec_pending to use for completion handling.
1641 struct bio *b = bio_split(bio, bio_sectors(bio) - ci.sector_count,
1642 GFP_NOIO, &md->queue->bio_split);
1643 ci.io->orig_bio = b;
1646 * Adjust IO stats for each split, otherwise upon queue
1647 * reentry there will be redundant IO accounting.
1648 * NOTE: this is a stop-gap fix, a proper fix involves
1649 * significant refactoring of DM core's bio splitting
1650 * (by eliminating DM's splitting and just using bio_split)
1653 __dm_part_stat_sub(&dm_disk(md)->part0,
1654 sectors[op_stat_group(bio_op(bio))], ci.sector_count);
1658 ret = generic_make_request(bio);
1664 /* drop the extra reference count */
1665 dec_pending(ci.io, errno_to_blk_status(error));
1670 * Optimized variant of __split_and_process_bio that leverages the
1671 * fact that targets that use it do _not_ have a need to split bios.
1673 static blk_qc_t __process_bio(struct mapped_device *md,
1674 struct dm_table *map, struct bio *bio)
1676 struct clone_info ci;
1677 blk_qc_t ret = BLK_QC_T_NONE;
1680 if (unlikely(!map)) {
1685 init_clone_info(&ci, md, map, bio);
1687 if (bio->bi_opf & REQ_PREFLUSH) {
1688 struct bio flush_bio;
1691 * Use an on-stack bio for this, it's safe since we don't
1692 * need to reference it after submit. It's just used as
1693 * the basis for the clone(s).
1695 bio_init(&flush_bio, NULL, 0);
1696 flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
1697 ci.bio = &flush_bio;
1698 ci.sector_count = 0;
1699 error = __send_empty_flush(&ci);
1700 /* dec_pending submits any data associated with flush */
1702 struct dm_target *ti = md->immutable_target;
1703 struct dm_target_io *tio;
1706 * Defend against IO still getting in during teardown
1707 * - as was seen for a time with nvme-fcloop
1709 if (WARN_ON_ONCE(!ti || !dm_target_is_valid(ti))) {
1715 ci.sector_count = bio_sectors(bio);
1716 if (unlikely(__process_abnormal_io(&ci, ti, &error)))
1719 tio = alloc_tio(&ci, ti, 0, GFP_NOIO);
1720 ret = __clone_and_map_simple_bio(&ci, tio, NULL);
1723 /* drop the extra reference count */
1724 dec_pending(ci.io, errno_to_blk_status(error));
1728 static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
1730 struct mapped_device *md = q->queuedata;
1731 blk_qc_t ret = BLK_QC_T_NONE;
1733 struct dm_table *map;
1735 map = dm_get_live_table(md, &srcu_idx);
1737 /* if we're suspended, we have to queue this io for later */
1738 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
1739 dm_put_live_table(md, srcu_idx);
1741 if (!(bio->bi_opf & REQ_RAHEAD))
1748 if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
1749 ret = __process_bio(md, map, bio);
1751 ret = __split_and_process_bio(md, map, bio);
1753 dm_put_live_table(md, srcu_idx);
1757 static int dm_any_congested(void *congested_data, int bdi_bits)
1760 struct mapped_device *md = congested_data;
1761 struct dm_table *map;
1763 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
1764 if (dm_request_based(md)) {
1766 * With request-based DM we only need to check the
1767 * top-level queue for congestion.
1769 r = md->queue->backing_dev_info->wb.state & bdi_bits;
1771 map = dm_get_live_table_fast(md);
1773 r = dm_table_any_congested(map, bdi_bits);
1774 dm_put_live_table_fast(md);
1781 /*-----------------------------------------------------------------
1782 * An IDR is used to keep track of allocated minor numbers.
1783 *---------------------------------------------------------------*/
1784 static void free_minor(int minor)
1786 spin_lock(&_minor_lock);
1787 idr_remove(&_minor_idr, minor);
1788 spin_unlock(&_minor_lock);
1792 * See if the device with a specific minor # is free.
1794 static int specific_minor(int minor)
1798 if (minor >= (1 << MINORBITS))
1801 idr_preload(GFP_KERNEL);
1802 spin_lock(&_minor_lock);
1804 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
1806 spin_unlock(&_minor_lock);
1809 return r == -ENOSPC ? -EBUSY : r;
1813 static int next_free_minor(int *minor)
1817 idr_preload(GFP_KERNEL);
1818 spin_lock(&_minor_lock);
1820 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
1822 spin_unlock(&_minor_lock);
1830 static const struct block_device_operations dm_blk_dops;
1831 static const struct dax_operations dm_dax_ops;
1833 static void dm_wq_work(struct work_struct *work);
1835 static void dm_init_normal_md_queue(struct mapped_device *md)
1838 * Initialize aspects of queue that aren't relevant for blk-mq
1840 md->queue->backing_dev_info->congested_fn = dm_any_congested;
1843 static void cleanup_mapped_device(struct mapped_device *md)
1846 destroy_workqueue(md->wq);
1847 bioset_exit(&md->bs);
1848 bioset_exit(&md->io_bs);
1851 kill_dax(md->dax_dev);
1852 put_dax(md->dax_dev);
1857 spin_lock(&_minor_lock);
1858 md->disk->private_data = NULL;
1859 spin_unlock(&_minor_lock);
1860 del_gendisk(md->disk);
1865 blk_cleanup_queue(md->queue);
1867 cleanup_srcu_struct(&md->io_barrier);
1874 mutex_destroy(&md->suspend_lock);
1875 mutex_destroy(&md->type_lock);
1876 mutex_destroy(&md->table_devices_lock);
1878 dm_mq_cleanup_mapped_device(md);
1882 * Allocate and initialise a blank device with a given minor.
1884 static struct mapped_device *alloc_dev(int minor)
1886 int r, numa_node_id = dm_get_numa_node();
1887 struct dax_device *dax_dev = NULL;
1888 struct mapped_device *md;
1891 md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
1893 DMWARN("unable to allocate device, out of memory.");
1897 if (!try_module_get(THIS_MODULE))
1898 goto bad_module_get;
1900 /* get a minor number for the dev */
1901 if (minor == DM_ANY_MINOR)
1902 r = next_free_minor(&minor);
1904 r = specific_minor(minor);
1908 r = init_srcu_struct(&md->io_barrier);
1910 goto bad_io_barrier;
1912 md->numa_node_id = numa_node_id;
1913 md->init_tio_pdu = false;
1914 md->type = DM_TYPE_NONE;
1915 mutex_init(&md->suspend_lock);
1916 mutex_init(&md->type_lock);
1917 mutex_init(&md->table_devices_lock);
1918 spin_lock_init(&md->deferred_lock);
1919 atomic_set(&md->holders, 1);
1920 atomic_set(&md->open_count, 0);
1921 atomic_set(&md->event_nr, 0);
1922 atomic_set(&md->uevent_seq, 0);
1923 INIT_LIST_HEAD(&md->uevent_list);
1924 INIT_LIST_HEAD(&md->table_devices);
1925 spin_lock_init(&md->uevent_lock);
1927 md->queue = blk_alloc_queue_node(GFP_KERNEL, numa_node_id);
1930 md->queue->queuedata = md;
1931 md->queue->backing_dev_info->congested_data = md;
1933 md->disk = alloc_disk_node(1, md->numa_node_id);
1937 init_waitqueue_head(&md->wait);
1938 INIT_WORK(&md->work, dm_wq_work);
1939 init_waitqueue_head(&md->eventq);
1940 init_completion(&md->kobj_holder.completion);
1942 md->disk->major = _major;
1943 md->disk->first_minor = minor;
1944 md->disk->fops = &dm_blk_dops;
1945 md->disk->queue = md->queue;
1946 md->disk->private_data = md;
1947 sprintf(md->disk->disk_name, "dm-%d", minor);
1949 if (IS_ENABLED(CONFIG_DAX_DRIVER)) {
1950 dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops);
1954 md->dax_dev = dax_dev;
1956 add_disk_no_queue_reg(md->disk);
1957 format_dev_t(md->name, MKDEV(_major, minor));
1959 md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
1963 md->bdev = bdget_disk(md->disk, 0);
1967 dm_stats_init(&md->stats);
1969 /* Populate the mapping, nobody knows we exist yet */
1970 spin_lock(&_minor_lock);
1971 old_md = idr_replace(&_minor_idr, md, minor);
1972 spin_unlock(&_minor_lock);
1974 BUG_ON(old_md != MINOR_ALLOCED);
1979 cleanup_mapped_device(md);
1983 module_put(THIS_MODULE);
1989 static void unlock_fs(struct mapped_device *md);
1991 static void free_dev(struct mapped_device *md)
1993 int minor = MINOR(disk_devt(md->disk));
1997 cleanup_mapped_device(md);
1999 free_table_devices(&md->table_devices);
2000 dm_stats_cleanup(&md->stats);
2003 module_put(THIS_MODULE);
2007 static int __bind_mempools(struct mapped_device *md, struct dm_table *t)
2009 struct dm_md_mempools *p = dm_table_get_md_mempools(t);
2012 if (dm_table_bio_based(t)) {
2014 * The md may already have mempools that need changing.
2015 * If so, reload bioset because front_pad may have changed
2016 * because a different table was loaded.
2018 bioset_exit(&md->bs);
2019 bioset_exit(&md->io_bs);
2021 } else if (bioset_initialized(&md->bs)) {
2023 * There's no need to reload with request-based dm
2024 * because the size of front_pad doesn't change.
2025 * Note for future: If you are to reload bioset,
2026 * prep-ed requests in the queue may refer
2027 * to bio from the old bioset, so you must walk
2028 * through the queue to unprep.
2034 bioset_initialized(&md->bs) ||
2035 bioset_initialized(&md->io_bs));
2037 ret = bioset_init_from_src(&md->bs, &p->bs);
2040 ret = bioset_init_from_src(&md->io_bs, &p->io_bs);
2042 bioset_exit(&md->bs);
2044 /* mempool bind completed, no longer need any mempools in the table */
2045 dm_table_free_md_mempools(t);
2050 * Bind a table to the device.
2052 static void event_callback(void *context)
2054 unsigned long flags;
2056 struct mapped_device *md = (struct mapped_device *) context;
2058 spin_lock_irqsave(&md->uevent_lock, flags);
2059 list_splice_init(&md->uevent_list, &uevents);
2060 spin_unlock_irqrestore(&md->uevent_lock, flags);
2062 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
2064 atomic_inc(&md->event_nr);
2065 wake_up(&md->eventq);
2066 dm_issue_global_event();
2070 * Protected by md->suspend_lock obtained by dm_swap_table().
2072 static void __set_size(struct mapped_device *md, sector_t size)
2074 lockdep_assert_held(&md->suspend_lock);
2076 set_capacity(md->disk, size);
2078 i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
2082 * Returns old map, which caller must destroy.
2084 static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
2085 struct queue_limits *limits)
2087 struct dm_table *old_map;
2088 struct request_queue *q = md->queue;
2089 bool request_based = dm_table_request_based(t);
2093 lockdep_assert_held(&md->suspend_lock);
2095 size = dm_table_get_size(t);
2098 * Wipe any geometry if the size of the table changed.
2100 if (size != dm_get_size(md))
2101 memset(&md->geometry, 0, sizeof(md->geometry));
2103 __set_size(md, size);
2105 dm_table_event_callback(t, event_callback, md);
2108 * The queue hasn't been stopped yet, if the old table type wasn't
2109 * for request-based during suspension. So stop it to prevent
2110 * I/O mapping before resume.
2111 * This must be done before setting the queue restrictions,
2112 * because request-based dm may be run just after the setting.
2117 if (request_based || md->type == DM_TYPE_NVME_BIO_BASED) {
2119 * Leverage the fact that request-based DM targets and
2120 * NVMe bio based targets are immutable singletons
2121 * - used to optimize both dm_request_fn and dm_mq_queue_rq;
2122 * and __process_bio.
2124 md->immutable_target = dm_table_get_immutable_target(t);
2127 ret = __bind_mempools(md, t);
2129 old_map = ERR_PTR(ret);
2133 old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2134 rcu_assign_pointer(md->map, (void *)t);
2135 md->immutable_target_type = dm_table_get_immutable_target_type(t);
2137 dm_table_set_restrictions(t, q, limits);
2146 * Returns unbound table for the caller to free.
2148 static struct dm_table *__unbind(struct mapped_device *md)
2150 struct dm_table *map = rcu_dereference_protected(md->map, 1);
2155 dm_table_event_callback(map, NULL, NULL);
2156 RCU_INIT_POINTER(md->map, NULL);
2163 * Constructor for a new device.
2165 int dm_create(int minor, struct mapped_device **result)
2168 struct mapped_device *md;
2170 md = alloc_dev(minor);
2174 r = dm_sysfs_init(md);
2185 * Functions to manage md->type.
2186 * All are required to hold md->type_lock.
2188 void dm_lock_md_type(struct mapped_device *md)
2190 mutex_lock(&md->type_lock);
2193 void dm_unlock_md_type(struct mapped_device *md)
2195 mutex_unlock(&md->type_lock);
2198 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type)
2200 BUG_ON(!mutex_is_locked(&md->type_lock));
2204 enum dm_queue_mode dm_get_md_type(struct mapped_device *md)
2209 struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
2211 return md->immutable_target_type;
2215 * The queue_limits are only valid as long as you have a reference
2218 struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
2220 BUG_ON(!atomic_read(&md->holders));
2221 return &md->queue->limits;
2223 EXPORT_SYMBOL_GPL(dm_get_queue_limits);
2226 * Setup the DM device's queue based on md's type
2228 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
2231 struct queue_limits limits;
2232 enum dm_queue_mode type = dm_get_md_type(md);
2235 case DM_TYPE_REQUEST_BASED:
2236 r = dm_mq_init_request_queue(md, t);
2238 DMERR("Cannot initialize queue for request-based dm-mq mapped device");
2242 case DM_TYPE_BIO_BASED:
2243 case DM_TYPE_DAX_BIO_BASED:
2244 case DM_TYPE_NVME_BIO_BASED:
2245 dm_init_normal_md_queue(md);
2246 blk_queue_make_request(md->queue, dm_make_request);
2253 r = dm_calculate_queue_limits(t, &limits);
2255 DMERR("Cannot calculate initial queue limits");
2258 dm_table_set_restrictions(t, md->queue, &limits);
2259 blk_register_queue(md->disk);
2264 struct mapped_device *dm_get_md(dev_t dev)
2266 struct mapped_device *md;
2267 unsigned minor = MINOR(dev);
2269 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
2272 spin_lock(&_minor_lock);
2274 md = idr_find(&_minor_idr, minor);
2275 if (!md || md == MINOR_ALLOCED || (MINOR(disk_devt(dm_disk(md))) != minor) ||
2276 test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
2282 spin_unlock(&_minor_lock);
2286 EXPORT_SYMBOL_GPL(dm_get_md);
2288 void *dm_get_mdptr(struct mapped_device *md)
2290 return md->interface_ptr;
2293 void dm_set_mdptr(struct mapped_device *md, void *ptr)
2295 md->interface_ptr = ptr;
2298 void dm_get(struct mapped_device *md)
2300 atomic_inc(&md->holders);
2301 BUG_ON(test_bit(DMF_FREEING, &md->flags));
2304 int dm_hold(struct mapped_device *md)
2306 spin_lock(&_minor_lock);
2307 if (test_bit(DMF_FREEING, &md->flags)) {
2308 spin_unlock(&_minor_lock);
2312 spin_unlock(&_minor_lock);
2315 EXPORT_SYMBOL_GPL(dm_hold);
2317 const char *dm_device_name(struct mapped_device *md)
2321 EXPORT_SYMBOL_GPL(dm_device_name);
2323 static void __dm_destroy(struct mapped_device *md, bool wait)
2325 struct dm_table *map;
2330 spin_lock(&_minor_lock);
2331 idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
2332 set_bit(DMF_FREEING, &md->flags);
2333 spin_unlock(&_minor_lock);
2335 blk_set_queue_dying(md->queue);
2338 * Take suspend_lock so that presuspend and postsuspend methods
2339 * do not race with internal suspend.
2341 mutex_lock(&md->suspend_lock);
2342 map = dm_get_live_table(md, &srcu_idx);
2343 if (!dm_suspended_md(md)) {
2344 dm_table_presuspend_targets(map);
2345 dm_table_postsuspend_targets(map);
2347 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2348 dm_put_live_table(md, srcu_idx);
2349 mutex_unlock(&md->suspend_lock);
2352 * Rare, but there may be I/O requests still going to complete,
2353 * for example. Wait for all references to disappear.
2354 * No one should increment the reference count of the mapped_device,
2355 * after the mapped_device state becomes DMF_FREEING.
2358 while (atomic_read(&md->holders))
2360 else if (atomic_read(&md->holders))
2361 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2362 dm_device_name(md), atomic_read(&md->holders));
2365 dm_table_destroy(__unbind(md));
2369 void dm_destroy(struct mapped_device *md)
2371 __dm_destroy(md, true);
2374 void dm_destroy_immediate(struct mapped_device *md)
2376 __dm_destroy(md, false);
2379 void dm_put(struct mapped_device *md)
2381 atomic_dec(&md->holders);
2383 EXPORT_SYMBOL_GPL(dm_put);
2385 static int dm_wait_for_completion(struct mapped_device *md, long task_state)
2391 prepare_to_wait(&md->wait, &wait, task_state);
2393 if (!md_in_flight(md))
2396 if (signal_pending_state(task_state, current)) {
2403 finish_wait(&md->wait, &wait);
2409 * Process the deferred bios
2411 static void dm_wq_work(struct work_struct *work)
2413 struct mapped_device *md = container_of(work, struct mapped_device,
2417 struct dm_table *map;
2419 map = dm_get_live_table(md, &srcu_idx);
2421 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
2422 spin_lock_irq(&md->deferred_lock);
2423 c = bio_list_pop(&md->deferred);
2424 spin_unlock_irq(&md->deferred_lock);
2429 if (dm_request_based(md))
2430 generic_make_request(c);
2432 __split_and_process_bio(md, map, c);
2435 dm_put_live_table(md, srcu_idx);
2438 static void dm_queue_flush(struct mapped_device *md)
2440 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2441 smp_mb__after_atomic();
2442 queue_work(md->wq, &md->work);
2446 * Swap in a new table, returning the old one for the caller to destroy.
2448 struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
2450 struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
2451 struct queue_limits limits;
2454 mutex_lock(&md->suspend_lock);
2456 /* device must be suspended */
2457 if (!dm_suspended_md(md))
2461 * If the new table has no data devices, retain the existing limits.
2462 * This helps multipath with queue_if_no_path if all paths disappear,
2463 * then new I/O is queued based on these limits, and then some paths
2466 if (dm_table_has_no_data_devices(table)) {
2467 live_map = dm_get_live_table_fast(md);
2469 limits = md->queue->limits;
2470 dm_put_live_table_fast(md);
2474 r = dm_calculate_queue_limits(table, &limits);
2481 map = __bind(md, table, &limits);
2482 dm_issue_global_event();
2485 mutex_unlock(&md->suspend_lock);
2490 * Functions to lock and unlock any filesystem running on the
2493 static int lock_fs(struct mapped_device *md)
2497 WARN_ON(md->frozen_sb);
2499 md->frozen_sb = freeze_bdev(md->bdev);
2500 if (IS_ERR(md->frozen_sb)) {
2501 r = PTR_ERR(md->frozen_sb);
2502 md->frozen_sb = NULL;
2506 set_bit(DMF_FROZEN, &md->flags);
2511 static void unlock_fs(struct mapped_device *md)
2513 if (!test_bit(DMF_FROZEN, &md->flags))
2516 thaw_bdev(md->bdev, md->frozen_sb);
2517 md->frozen_sb = NULL;
2518 clear_bit(DMF_FROZEN, &md->flags);
2522 * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG
2523 * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE
2524 * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY
2526 * If __dm_suspend returns 0, the device is completely quiescent
2527 * now. There is no request-processing activity. All new requests
2528 * are being added to md->deferred list.
2530 static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
2531 unsigned suspend_flags, long task_state,
2532 int dmf_suspended_flag)
2534 bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
2535 bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
2538 lockdep_assert_held(&md->suspend_lock);
2541 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2542 * This flag is cleared before dm_suspend returns.
2545 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2547 pr_debug("%s: suspending with flush\n", dm_device_name(md));
2550 * This gets reverted if there's an error later and the targets
2551 * provide the .presuspend_undo hook.
2553 dm_table_presuspend_targets(map);
2556 * Flush I/O to the device.
2557 * Any I/O submitted after lock_fs() may not be flushed.
2558 * noflush takes precedence over do_lockfs.
2559 * (lock_fs() flushes I/Os and waits for them to complete.)
2561 if (!noflush && do_lockfs) {
2564 dm_table_presuspend_undo_targets(map);
2570 * Here we must make sure that no processes are submitting requests
2571 * to target drivers i.e. no one may be executing
2572 * __split_and_process_bio. This is called from dm_request and
2575 * To get all processes out of __split_and_process_bio in dm_request,
2576 * we take the write lock. To prevent any process from reentering
2577 * __split_and_process_bio from dm_request and quiesce the thread
2578 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2579 * flush_workqueue(md->wq).
2581 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2583 synchronize_srcu(&md->io_barrier);
2586 * Stop md->queue before flushing md->wq in case request-based
2587 * dm defers requests to md->wq from md->queue.
2589 if (dm_request_based(md))
2590 dm_stop_queue(md->queue);
2592 flush_workqueue(md->wq);
2595 * At this point no more requests are entering target request routines.
2596 * We call dm_wait_for_completion to wait for all existing requests
2599 r = dm_wait_for_completion(md, task_state);
2601 set_bit(dmf_suspended_flag, &md->flags);
2604 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2606 synchronize_srcu(&md->io_barrier);
2608 /* were we interrupted ? */
2612 if (dm_request_based(md))
2613 dm_start_queue(md->queue);
2616 dm_table_presuspend_undo_targets(map);
2617 /* pushback list is already flushed, so skip flush */
2624 * We need to be able to change a mapping table under a mounted
2625 * filesystem. For example we might want to move some data in
2626 * the background. Before the table can be swapped with
2627 * dm_bind_table, dm_suspend must be called to flush any in
2628 * flight bios and ensure that any further io gets deferred.
2631 * Suspend mechanism in request-based dm.
2633 * 1. Flush all I/Os by lock_fs() if needed.
2634 * 2. Stop dispatching any I/O by stopping the request_queue.
2635 * 3. Wait for all in-flight I/Os to be completed or requeued.
2637 * To abort suspend, start the request_queue.
2639 int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
2641 struct dm_table *map = NULL;
2645 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2647 if (dm_suspended_md(md)) {
2652 if (dm_suspended_internally_md(md)) {
2653 /* already internally suspended, wait for internal resume */
2654 mutex_unlock(&md->suspend_lock);
2655 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2661 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2663 r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);
2667 dm_table_postsuspend_targets(map);
2670 mutex_unlock(&md->suspend_lock);
2674 static int __dm_resume(struct mapped_device *md, struct dm_table *map)
2677 int r = dm_table_resume_targets(map);
2685 * Flushing deferred I/Os must be done after targets are resumed
2686 * so that mapping of targets can work correctly.
2687 * Request-based dm is queueing the deferred I/Os in its request_queue.
2689 if (dm_request_based(md))
2690 dm_start_queue(md->queue);
2697 int dm_resume(struct mapped_device *md)
2700 struct dm_table *map = NULL;
2704 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2706 if (!dm_suspended_md(md))
2709 if (dm_suspended_internally_md(md)) {
2710 /* already internally suspended, wait for internal resume */
2711 mutex_unlock(&md->suspend_lock);
2712 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2718 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2719 if (!map || !dm_table_get_size(map))
2722 r = __dm_resume(md, map);
2726 clear_bit(DMF_SUSPENDED, &md->flags);
2728 mutex_unlock(&md->suspend_lock);
2734 * Internal suspend/resume works like userspace-driven suspend. It waits
2735 * until all bios finish and prevents issuing new bios to the target drivers.
2736 * It may be used only from the kernel.
2739 static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
2741 struct dm_table *map = NULL;
2743 lockdep_assert_held(&md->suspend_lock);
2745 if (md->internal_suspend_count++)
2746 return; /* nested internal suspend */
2748 if (dm_suspended_md(md)) {
2749 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2750 return; /* nest suspend */
2753 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2756 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
2757 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
2758 * would require changing .presuspend to return an error -- avoid this
2759 * until there is a need for more elaborate variants of internal suspend.
2761 (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
2762 DMF_SUSPENDED_INTERNALLY);
2764 dm_table_postsuspend_targets(map);
2767 static void __dm_internal_resume(struct mapped_device *md)
2769 BUG_ON(!md->internal_suspend_count);
2771 if (--md->internal_suspend_count)
2772 return; /* resume from nested internal suspend */
2774 if (dm_suspended_md(md))
2775 goto done; /* resume from nested suspend */
2778 * NOTE: existing callers don't need to call dm_table_resume_targets
2779 * (which may fail -- so best to avoid it for now by passing NULL map)
2781 (void) __dm_resume(md, NULL);
2784 clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2785 smp_mb__after_atomic();
2786 wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
2789 void dm_internal_suspend_noflush(struct mapped_device *md)
2791 mutex_lock(&md->suspend_lock);
2792 __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
2793 mutex_unlock(&md->suspend_lock);
2795 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
2797 void dm_internal_resume(struct mapped_device *md)
2799 mutex_lock(&md->suspend_lock);
2800 __dm_internal_resume(md);
2801 mutex_unlock(&md->suspend_lock);
2803 EXPORT_SYMBOL_GPL(dm_internal_resume);
2806 * Fast variants of internal suspend/resume hold md->suspend_lock,
2807 * which prevents interaction with userspace-driven suspend.
2810 void dm_internal_suspend_fast(struct mapped_device *md)
2812 mutex_lock(&md->suspend_lock);
2813 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2816 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2817 synchronize_srcu(&md->io_barrier);
2818 flush_workqueue(md->wq);
2819 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
2821 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
2823 void dm_internal_resume_fast(struct mapped_device *md)
2825 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2831 mutex_unlock(&md->suspend_lock);
2833 EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
2835 /*-----------------------------------------------------------------
2836 * Event notification.
2837 *---------------------------------------------------------------*/
2838 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
2841 char udev_cookie[DM_COOKIE_LENGTH];
2842 char *envp[] = { udev_cookie, NULL };
2845 return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
2847 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
2848 DM_COOKIE_ENV_VAR_NAME, cookie);
2849 return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
2854 uint32_t dm_next_uevent_seq(struct mapped_device *md)
2856 return atomic_add_return(1, &md->uevent_seq);
2859 uint32_t dm_get_event_nr(struct mapped_device *md)
2861 return atomic_read(&md->event_nr);
2864 int dm_wait_event(struct mapped_device *md, int event_nr)
2866 return wait_event_interruptible(md->eventq,
2867 (event_nr != atomic_read(&md->event_nr)));
2870 void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
2872 unsigned long flags;
2874 spin_lock_irqsave(&md->uevent_lock, flags);
2875 list_add(elist, &md->uevent_list);
2876 spin_unlock_irqrestore(&md->uevent_lock, flags);
2880 * The gendisk is only valid as long as you have a reference
2883 struct gendisk *dm_disk(struct mapped_device *md)
2887 EXPORT_SYMBOL_GPL(dm_disk);
2889 struct kobject *dm_kobject(struct mapped_device *md)
2891 return &md->kobj_holder.kobj;
2894 struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
2896 struct mapped_device *md;
2898 md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
2900 spin_lock(&_minor_lock);
2901 if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
2907 spin_unlock(&_minor_lock);
2912 int dm_suspended_md(struct mapped_device *md)
2914 return test_bit(DMF_SUSPENDED, &md->flags);
2917 int dm_suspended_internally_md(struct mapped_device *md)
2919 return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2922 int dm_test_deferred_remove_flag(struct mapped_device *md)
2924 return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
2927 int dm_suspended(struct dm_target *ti)
2929 return dm_suspended_md(dm_table_get_md(ti->table));
2931 EXPORT_SYMBOL_GPL(dm_suspended);
2933 int dm_noflush_suspending(struct dm_target *ti)
2935 return __noflush_suspending(dm_table_get_md(ti->table));
2937 EXPORT_SYMBOL_GPL(dm_noflush_suspending);
2939 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
2940 unsigned integrity, unsigned per_io_data_size,
2941 unsigned min_pool_size)
2943 struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
2944 unsigned int pool_size = 0;
2945 unsigned int front_pad, io_front_pad;
2952 case DM_TYPE_BIO_BASED:
2953 case DM_TYPE_DAX_BIO_BASED:
2954 case DM_TYPE_NVME_BIO_BASED:
2955 pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
2956 front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
2957 io_front_pad = roundup(front_pad, __alignof__(struct dm_io)) + offsetof(struct dm_io, tio);
2958 ret = bioset_init(&pools->io_bs, pool_size, io_front_pad, 0);
2961 if (integrity && bioset_integrity_create(&pools->io_bs, pool_size))
2964 case DM_TYPE_REQUEST_BASED:
2965 pool_size = max(dm_get_reserved_rq_based_ios(), min_pool_size);
2966 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
2967 /* per_io_data_size is used for blk-mq pdu at queue allocation */
2973 ret = bioset_init(&pools->bs, pool_size, front_pad, 0);
2977 if (integrity && bioset_integrity_create(&pools->bs, pool_size))
2983 dm_free_md_mempools(pools);
2988 void dm_free_md_mempools(struct dm_md_mempools *pools)
2993 bioset_exit(&pools->bs);
2994 bioset_exit(&pools->io_bs);
3006 static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
3009 struct mapped_device *md = bdev->bd_disk->private_data;
3010 struct dm_table *table;
3011 struct dm_target *ti;
3012 int ret = -ENOTTY, srcu_idx;
3014 table = dm_get_live_table(md, &srcu_idx);
3015 if (!table || !dm_table_get_size(table))
3018 /* We only support devices that have a single target */
3019 if (dm_table_get_num_targets(table) != 1)
3021 ti = dm_table_get_target(table, 0);
3024 if (!ti->type->iterate_devices)
3027 ret = ti->type->iterate_devices(ti, fn, data);
3029 dm_put_live_table(md, srcu_idx);
3034 * For register / unregister we need to manually call out to every path.
3036 static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev,
3037 sector_t start, sector_t len, void *data)
3039 struct dm_pr *pr = data;
3040 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
3042 if (!ops || !ops->pr_register)
3044 return ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
3047 static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
3058 ret = dm_call_pr(bdev, __dm_pr_register, &pr);
3059 if (ret && new_key) {
3060 /* unregister all paths if we failed to register any path */
3061 pr.old_key = new_key;
3064 pr.fail_early = false;
3065 dm_call_pr(bdev, __dm_pr_register, &pr);
3071 static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
3074 struct mapped_device *md = bdev->bd_disk->private_data;
3075 const struct pr_ops *ops;
3078 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3082 ops = bdev->bd_disk->fops->pr_ops;
3083 if (ops && ops->pr_reserve)
3084 r = ops->pr_reserve(bdev, key, type, flags);
3088 dm_unprepare_ioctl(md, srcu_idx);
3092 static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
3094 struct mapped_device *md = bdev->bd_disk->private_data;
3095 const struct pr_ops *ops;
3098 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3102 ops = bdev->bd_disk->fops->pr_ops;
3103 if (ops && ops->pr_release)
3104 r = ops->pr_release(bdev, key, type);
3108 dm_unprepare_ioctl(md, srcu_idx);
3112 static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
3113 enum pr_type type, bool abort)
3115 struct mapped_device *md = bdev->bd_disk->private_data;
3116 const struct pr_ops *ops;
3119 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3123 ops = bdev->bd_disk->fops->pr_ops;
3124 if (ops && ops->pr_preempt)
3125 r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
3129 dm_unprepare_ioctl(md, srcu_idx);
3133 static int dm_pr_clear(struct block_device *bdev, u64 key)
3135 struct mapped_device *md = bdev->bd_disk->private_data;
3136 const struct pr_ops *ops;
3139 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3143 ops = bdev->bd_disk->fops->pr_ops;
3144 if (ops && ops->pr_clear)
3145 r = ops->pr_clear(bdev, key);
3149 dm_unprepare_ioctl(md, srcu_idx);
3153 static const struct pr_ops dm_pr_ops = {
3154 .pr_register = dm_pr_register,
3155 .pr_reserve = dm_pr_reserve,
3156 .pr_release = dm_pr_release,
3157 .pr_preempt = dm_pr_preempt,
3158 .pr_clear = dm_pr_clear,
3161 static const struct block_device_operations dm_blk_dops = {
3162 .open = dm_blk_open,
3163 .release = dm_blk_close,
3164 .ioctl = dm_blk_ioctl,
3165 .getgeo = dm_blk_getgeo,
3166 .report_zones = dm_blk_report_zones,
3167 .pr_ops = &dm_pr_ops,
3168 .owner = THIS_MODULE
3171 static const struct dax_operations dm_dax_ops = {
3172 .direct_access = dm_dax_direct_access,
3173 .copy_from_iter = dm_dax_copy_from_iter,
3174 .copy_to_iter = dm_dax_copy_to_iter,
3180 module_init(dm_init);
3181 module_exit(dm_exit);
3183 module_param(major, uint, 0);
3184 MODULE_PARM_DESC(major, "The major number of the device mapper");
3186 module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
3187 MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
3189 module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
3190 MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
3192 MODULE_DESCRIPTION(DM_NAME " driver");
3193 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3194 MODULE_LICENSE("GPL");