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"
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/sched/mm.h>
17 #include <linux/sched/signal.h>
18 #include <linux/blkpg.h>
19 #include <linux/bio.h>
20 #include <linux/mempool.h>
21 #include <linux/dax.h>
22 #include <linux/slab.h>
23 #include <linux/idr.h>
24 #include <linux/uio.h>
25 #include <linux/hdreg.h>
26 #include <linux/delay.h>
27 #include <linux/wait.h>
29 #include <linux/refcount.h>
30 #include <linux/part_stat.h>
31 #include <linux/blk-crypto.h>
32 #include <linux/blk-crypto-profile.h>
34 #define DM_MSG_PREFIX "core"
37 * Cookies are numeric values sent with CHANGE and REMOVE
38 * uevents while resuming, removing or renaming the device.
40 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
41 #define DM_COOKIE_LENGTH 24
44 * For REQ_POLLED fs bio, this flag is set if we link mapped underlying
45 * dm_io into one list, and reuse bio->bi_private as the list head. Before
46 * ending this fs bio, we will recover its ->bi_private.
48 #define REQ_DM_POLL_LIST REQ_DRV
50 static const char *_name = DM_NAME;
52 static unsigned int major = 0;
53 static unsigned int _major = 0;
55 static DEFINE_IDR(_minor_idr);
57 static DEFINE_SPINLOCK(_minor_lock);
59 static void do_deferred_remove(struct work_struct *w);
61 static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
63 static struct workqueue_struct *deferred_remove_workqueue;
65 atomic_t dm_global_event_nr = ATOMIC_INIT(0);
66 DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq);
68 void dm_issue_global_event(void)
70 atomic_inc(&dm_global_event_nr);
71 wake_up(&dm_global_eventq);
75 * One of these is allocated (on-stack) per original bio.
82 unsigned sector_count;
83 bool submit_as_polled;
86 #define DM_TARGET_IO_BIO_OFFSET (offsetof(struct dm_target_io, clone))
87 #define DM_IO_BIO_OFFSET \
88 (offsetof(struct dm_target_io, clone) + offsetof(struct dm_io, tio))
90 static inline struct dm_target_io *clone_to_tio(struct bio *clone)
92 return container_of(clone, struct dm_target_io, clone);
95 void *dm_per_bio_data(struct bio *bio, size_t data_size)
97 if (!dm_tio_flagged(clone_to_tio(bio), DM_TIO_INSIDE_DM_IO))
98 return (char *)bio - DM_TARGET_IO_BIO_OFFSET - data_size;
99 return (char *)bio - DM_IO_BIO_OFFSET - data_size;
101 EXPORT_SYMBOL_GPL(dm_per_bio_data);
103 struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size)
105 struct dm_io *io = (struct dm_io *)((char *)data + data_size);
106 if (io->magic == DM_IO_MAGIC)
107 return (struct bio *)((char *)io + DM_IO_BIO_OFFSET);
108 BUG_ON(io->magic != DM_TIO_MAGIC);
109 return (struct bio *)((char *)io + DM_TARGET_IO_BIO_OFFSET);
111 EXPORT_SYMBOL_GPL(dm_bio_from_per_bio_data);
113 unsigned dm_bio_get_target_bio_nr(const struct bio *bio)
115 return container_of(bio, struct dm_target_io, clone)->target_bio_nr;
117 EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr);
119 #define MINOR_ALLOCED ((void *)-1)
121 #define DM_NUMA_NODE NUMA_NO_NODE
122 static int dm_numa_node = DM_NUMA_NODE;
124 #define DEFAULT_SWAP_BIOS (8 * 1048576 / PAGE_SIZE)
125 static int swap_bios = DEFAULT_SWAP_BIOS;
126 static int get_swap_bios(void)
128 int latch = READ_ONCE(swap_bios);
129 if (unlikely(latch <= 0))
130 latch = DEFAULT_SWAP_BIOS;
135 * For mempools pre-allocation at the table loading time.
137 struct dm_md_mempools {
139 struct bio_set io_bs;
142 struct table_device {
143 struct list_head list;
145 struct dm_dev dm_dev;
149 * Bio-based DM's mempools' reserved IOs set by the user.
151 #define RESERVED_BIO_BASED_IOS 16
152 static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
154 static int __dm_get_module_param_int(int *module_param, int min, int max)
156 int param = READ_ONCE(*module_param);
157 int modified_param = 0;
158 bool modified = true;
161 modified_param = min;
162 else if (param > max)
163 modified_param = max;
168 (void)cmpxchg(module_param, param, modified_param);
169 param = modified_param;
175 unsigned __dm_get_module_param(unsigned *module_param,
176 unsigned def, unsigned max)
178 unsigned param = READ_ONCE(*module_param);
179 unsigned modified_param = 0;
182 modified_param = def;
183 else if (param > max)
184 modified_param = max;
186 if (modified_param) {
187 (void)cmpxchg(module_param, param, modified_param);
188 param = modified_param;
194 unsigned dm_get_reserved_bio_based_ios(void)
196 return __dm_get_module_param(&reserved_bio_based_ios,
197 RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS);
199 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
201 static unsigned dm_get_numa_node(void)
203 return __dm_get_module_param_int(&dm_numa_node,
204 DM_NUMA_NODE, num_online_nodes() - 1);
207 static int __init local_init(void)
211 r = dm_uevent_init();
215 deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
216 if (!deferred_remove_workqueue) {
218 goto out_uevent_exit;
222 r = register_blkdev(_major, _name);
224 goto out_free_workqueue;
232 destroy_workqueue(deferred_remove_workqueue);
239 static void local_exit(void)
241 flush_scheduled_work();
242 destroy_workqueue(deferred_remove_workqueue);
244 unregister_blkdev(_major, _name);
249 DMINFO("cleaned up");
252 static int (*_inits[])(void) __initdata = {
263 static void (*_exits[])(void) = {
274 static int __init dm_init(void)
276 const int count = ARRAY_SIZE(_inits);
279 #if (IS_ENABLED(CONFIG_IMA) && !IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE))
280 DMWARN("CONFIG_IMA_DISABLE_HTABLE is disabled."
281 " Duplicate IMA measurements will not be recorded in the IMA log.");
284 for (i = 0; i < count; i++) {
298 static void __exit dm_exit(void)
300 int i = ARRAY_SIZE(_exits);
306 * Should be empty by this point.
308 idr_destroy(&_minor_idr);
312 * Block device functions
314 int dm_deleting_md(struct mapped_device *md)
316 return test_bit(DMF_DELETING, &md->flags);
319 static int dm_blk_open(struct block_device *bdev, fmode_t mode)
321 struct mapped_device *md;
323 spin_lock(&_minor_lock);
325 md = bdev->bd_disk->private_data;
329 if (test_bit(DMF_FREEING, &md->flags) ||
330 dm_deleting_md(md)) {
336 atomic_inc(&md->open_count);
338 spin_unlock(&_minor_lock);
340 return md ? 0 : -ENXIO;
343 static void dm_blk_close(struct gendisk *disk, fmode_t mode)
345 struct mapped_device *md;
347 spin_lock(&_minor_lock);
349 md = disk->private_data;
353 if (atomic_dec_and_test(&md->open_count) &&
354 (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
355 queue_work(deferred_remove_workqueue, &deferred_remove_work);
359 spin_unlock(&_minor_lock);
362 int dm_open_count(struct mapped_device *md)
364 return atomic_read(&md->open_count);
368 * Guarantees nothing is using the device before it's deleted.
370 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
374 spin_lock(&_minor_lock);
376 if (dm_open_count(md)) {
379 set_bit(DMF_DEFERRED_REMOVE, &md->flags);
380 } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
383 set_bit(DMF_DELETING, &md->flags);
385 spin_unlock(&_minor_lock);
390 int dm_cancel_deferred_remove(struct mapped_device *md)
394 spin_lock(&_minor_lock);
396 if (test_bit(DMF_DELETING, &md->flags))
399 clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
401 spin_unlock(&_minor_lock);
406 static void do_deferred_remove(struct work_struct *w)
408 dm_deferred_remove();
411 static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
413 struct mapped_device *md = bdev->bd_disk->private_data;
415 return dm_get_geometry(md, geo);
418 static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx,
419 struct block_device **bdev)
421 struct dm_target *tgt;
422 struct dm_table *map;
427 map = dm_get_live_table(md, srcu_idx);
428 if (!map || !dm_table_get_size(map))
431 /* We only support devices that have a single target */
432 if (dm_table_get_num_targets(map) != 1)
435 tgt = dm_table_get_target(map, 0);
436 if (!tgt->type->prepare_ioctl)
439 if (dm_suspended_md(md))
442 r = tgt->type->prepare_ioctl(tgt, bdev);
443 if (r == -ENOTCONN && !fatal_signal_pending(current)) {
444 dm_put_live_table(md, *srcu_idx);
452 static void dm_unprepare_ioctl(struct mapped_device *md, int srcu_idx)
454 dm_put_live_table(md, srcu_idx);
457 static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
458 unsigned int cmd, unsigned long arg)
460 struct mapped_device *md = bdev->bd_disk->private_data;
463 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
469 * Target determined this ioctl is being issued against a
470 * subset of the parent bdev; require extra privileges.
472 if (!capable(CAP_SYS_RAWIO)) {
474 "%s: sending ioctl %x to DM device without required privilege.",
481 if (!bdev->bd_disk->fops->ioctl)
484 r = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
486 dm_unprepare_ioctl(md, srcu_idx);
490 u64 dm_start_time_ns_from_clone(struct bio *bio)
492 return jiffies_to_nsecs(clone_to_tio(bio)->io->start_time);
494 EXPORT_SYMBOL_GPL(dm_start_time_ns_from_clone);
496 static bool bio_is_flush_with_data(struct bio *bio)
498 return ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size);
501 static void dm_io_acct(bool end, struct mapped_device *md, struct bio *bio,
502 unsigned long start_time, struct dm_stats_aux *stats_aux)
504 bool is_flush_with_data;
505 unsigned int bi_size;
507 /* If REQ_PREFLUSH set save any payload but do not account it */
508 is_flush_with_data = bio_is_flush_with_data(bio);
509 if (is_flush_with_data) {
510 bi_size = bio->bi_iter.bi_size;
511 bio->bi_iter.bi_size = 0;
515 bio_start_io_acct_time(bio, start_time);
517 bio_end_io_acct(bio, start_time);
519 if (unlikely(dm_stats_used(&md->stats)))
520 dm_stats_account_io(&md->stats, bio_data_dir(bio),
521 bio->bi_iter.bi_sector, bio_sectors(bio),
522 end, start_time, stats_aux);
524 /* Restore bio's payload so it does get accounted upon requeue */
525 if (is_flush_with_data)
526 bio->bi_iter.bi_size = bi_size;
529 static void __dm_start_io_acct(struct dm_io *io, struct bio *bio)
531 dm_io_acct(false, io->md, bio, io->start_time, &io->stats_aux);
534 static void dm_start_io_acct(struct dm_io *io, struct bio *clone)
536 /* Must account IO to DM device in terms of orig_bio */
537 struct bio *bio = io->orig_bio;
540 * Ensure IO accounting is only ever started once.
541 * Expect no possibility for race unless DM_TIO_IS_DUPLICATE_BIO.
544 likely(!dm_tio_flagged(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO))) {
545 if (WARN_ON_ONCE(dm_io_flagged(io, DM_IO_ACCOUNTED)))
547 dm_io_set_flag(io, DM_IO_ACCOUNTED);
550 if (dm_io_flagged(io, DM_IO_ACCOUNTED))
552 /* Can afford locking given DM_TIO_IS_DUPLICATE_BIO */
553 spin_lock_irqsave(&io->lock, flags);
554 dm_io_set_flag(io, DM_IO_ACCOUNTED);
555 spin_unlock_irqrestore(&io->lock, flags);
558 __dm_start_io_acct(io, bio);
561 static void dm_end_io_acct(struct dm_io *io, struct bio *bio)
563 dm_io_acct(true, io->md, bio, io->start_time, &io->stats_aux);
566 static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio)
569 struct dm_target_io *tio;
572 clone = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO, &md->io_bs);
574 tio = clone_to_tio(clone);
576 dm_tio_set_flag(tio, DM_TIO_INSIDE_DM_IO);
579 io = container_of(tio, struct dm_io, tio);
580 io->magic = DM_IO_MAGIC;
582 atomic_set(&io->io_count, 1);
583 this_cpu_inc(*md->pending_io);
586 io->map_task = current;
587 spin_lock_init(&io->lock);
588 io->start_time = jiffies;
591 dm_stats_record_start(&md->stats, &io->stats_aux);
596 static void free_io(struct dm_io *io)
598 bio_put(&io->tio.clone);
601 static struct bio *alloc_tio(struct clone_info *ci, struct dm_target *ti,
602 unsigned target_bio_nr, unsigned *len, gfp_t gfp_mask)
604 struct dm_target_io *tio;
607 if (!ci->io->tio.io) {
608 /* the dm_target_io embedded in ci->io is available */
610 /* alloc_io() already initialized embedded clone */
613 clone = bio_alloc_clone(ci->bio->bi_bdev, ci->bio,
614 gfp_mask, &ci->io->md->bs);
618 /* REQ_DM_POLL_LIST shouldn't be inherited */
619 clone->bi_opf &= ~REQ_DM_POLL_LIST;
621 tio = clone_to_tio(clone);
622 tio->flags = 0; /* also clears DM_TIO_INSIDE_DM_IO */
625 tio->magic = DM_TIO_MAGIC;
628 tio->target_bio_nr = target_bio_nr;
633 clone->bi_iter.bi_size = to_bytes(*len);
634 if (bio_integrity(clone))
635 bio_integrity_trim(clone);
641 static void free_tio(struct bio *clone)
643 if (dm_tio_flagged(clone_to_tio(clone), DM_TIO_INSIDE_DM_IO))
649 * Add the bio to the list of deferred io.
651 static void queue_io(struct mapped_device *md, struct bio *bio)
655 spin_lock_irqsave(&md->deferred_lock, flags);
656 bio_list_add(&md->deferred, bio);
657 spin_unlock_irqrestore(&md->deferred_lock, flags);
658 queue_work(md->wq, &md->work);
662 * Everyone (including functions in this file), should use this
663 * function to access the md->map field, and make sure they call
664 * dm_put_live_table() when finished.
666 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
668 *srcu_idx = srcu_read_lock(&md->io_barrier);
670 return srcu_dereference(md->map, &md->io_barrier);
673 void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
675 srcu_read_unlock(&md->io_barrier, srcu_idx);
678 void dm_sync_table(struct mapped_device *md)
680 synchronize_srcu(&md->io_barrier);
681 synchronize_rcu_expedited();
685 * A fast alternative to dm_get_live_table/dm_put_live_table.
686 * The caller must not block between these two functions.
688 static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
691 return rcu_dereference(md->map);
694 static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
699 static char *_dm_claim_ptr = "I belong to device-mapper";
702 * Open a table device so we can use it as a map destination.
704 static int open_table_device(struct table_device *td, dev_t dev,
705 struct mapped_device *md)
707 struct block_device *bdev;
711 BUG_ON(td->dm_dev.bdev);
713 bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr);
715 return PTR_ERR(bdev);
717 r = bd_link_disk_holder(bdev, dm_disk(md));
719 blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
723 td->dm_dev.bdev = bdev;
724 td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev, &part_off);
729 * Close a table device that we've been using.
731 static void close_table_device(struct table_device *td, struct mapped_device *md)
733 if (!td->dm_dev.bdev)
736 bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
737 blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
738 put_dax(td->dm_dev.dax_dev);
739 td->dm_dev.bdev = NULL;
740 td->dm_dev.dax_dev = NULL;
743 static struct table_device *find_table_device(struct list_head *l, dev_t dev,
746 struct table_device *td;
748 list_for_each_entry(td, l, list)
749 if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
755 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
756 struct dm_dev **result)
759 struct table_device *td;
761 mutex_lock(&md->table_devices_lock);
762 td = find_table_device(&md->table_devices, dev, mode);
764 td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
766 mutex_unlock(&md->table_devices_lock);
770 td->dm_dev.mode = mode;
771 td->dm_dev.bdev = NULL;
773 if ((r = open_table_device(td, dev, md))) {
774 mutex_unlock(&md->table_devices_lock);
779 format_dev_t(td->dm_dev.name, dev);
781 refcount_set(&td->count, 1);
782 list_add(&td->list, &md->table_devices);
784 refcount_inc(&td->count);
786 mutex_unlock(&md->table_devices_lock);
788 *result = &td->dm_dev;
792 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
794 struct table_device *td = container_of(d, struct table_device, dm_dev);
796 mutex_lock(&md->table_devices_lock);
797 if (refcount_dec_and_test(&td->count)) {
798 close_table_device(td, md);
802 mutex_unlock(&md->table_devices_lock);
805 static void free_table_devices(struct list_head *devices)
807 struct list_head *tmp, *next;
809 list_for_each_safe(tmp, next, devices) {
810 struct table_device *td = list_entry(tmp, struct table_device, list);
812 DMWARN("dm_destroy: %s still exists with %d references",
813 td->dm_dev.name, refcount_read(&td->count));
819 * Get the geometry associated with a dm device
821 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
829 * Set the geometry of a device.
831 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
833 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
835 if (geo->start > sz) {
836 DMWARN("Start sector is beyond the geometry limits.");
845 static int __noflush_suspending(struct mapped_device *md)
847 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
850 static void dm_io_complete(struct dm_io *io)
852 blk_status_t io_error;
853 struct mapped_device *md = io->md;
854 struct bio *bio = io->orig_bio;
856 if (io->status == BLK_STS_DM_REQUEUE) {
859 * Target requested pushing back the I/O.
861 spin_lock_irqsave(&md->deferred_lock, flags);
862 if (__noflush_suspending(md) &&
863 !WARN_ON_ONCE(dm_is_zone_write(md, bio))) {
864 /* NOTE early return due to BLK_STS_DM_REQUEUE below */
865 bio_list_add_head(&md->deferred, bio);
868 * noflush suspend was interrupted or this is
869 * a write to a zoned target.
871 io->status = BLK_STS_IOERR;
873 spin_unlock_irqrestore(&md->deferred_lock, flags);
876 io_error = io->status;
877 if (dm_io_flagged(io, DM_IO_ACCOUNTED))
878 dm_end_io_acct(io, bio);
879 else if (!io_error) {
881 * Must handle target that DM_MAPIO_SUBMITTED only to
882 * then bio_endio() rather than dm_submit_bio_remap()
884 __dm_start_io_acct(io, bio);
885 dm_end_io_acct(io, bio);
889 this_cpu_dec(*md->pending_io);
891 /* nudge anyone waiting on suspend queue */
892 if (unlikely(wq_has_sleeper(&md->wait)))
895 if (io_error == BLK_STS_DM_REQUEUE || io_error == BLK_STS_AGAIN) {
896 if (bio->bi_opf & REQ_POLLED) {
898 * Upper layer won't help us poll split bio (io->orig_bio
899 * may only reflect a subset of the pre-split original)
900 * so clear REQ_POLLED in case of requeue.
902 bio->bi_opf &= ~REQ_POLLED;
903 if (io_error == BLK_STS_AGAIN) {
904 /* io_uring doesn't handle BLK_STS_AGAIN (yet) */
911 if (bio_is_flush_with_data(bio)) {
913 * Preflush done for flush with data, reissue
914 * without REQ_PREFLUSH.
916 bio->bi_opf &= ~REQ_PREFLUSH;
919 /* done with normal IO or empty flush */
921 bio->bi_status = io_error;
926 static inline bool dm_tio_is_normal(struct dm_target_io *tio)
928 return (dm_tio_flagged(tio, DM_TIO_INSIDE_DM_IO) &&
929 !dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));
933 * Decrements the number of outstanding ios that a bio has been
934 * cloned into, completing the original io if necc.
936 void dm_io_dec_pending(struct dm_io *io, blk_status_t error)
938 /* Push-back supersedes any I/O errors */
939 if (unlikely(error)) {
941 spin_lock_irqsave(&io->lock, flags);
942 if (!(io->status == BLK_STS_DM_REQUEUE &&
943 __noflush_suspending(io->md)))
945 spin_unlock_irqrestore(&io->lock, flags);
948 if (atomic_dec_and_test(&io->io_count))
952 void disable_discard(struct mapped_device *md)
954 struct queue_limits *limits = dm_get_queue_limits(md);
956 /* device doesn't really support DISCARD, disable it */
957 limits->max_discard_sectors = 0;
958 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, md->queue);
961 void disable_write_zeroes(struct mapped_device *md)
963 struct queue_limits *limits = dm_get_queue_limits(md);
965 /* device doesn't really support WRITE ZEROES, disable it */
966 limits->max_write_zeroes_sectors = 0;
969 static bool swap_bios_limit(struct dm_target *ti, struct bio *bio)
971 return unlikely((bio->bi_opf & REQ_SWAP) != 0) && unlikely(ti->limit_swap_bios);
974 static void clone_endio(struct bio *bio)
976 blk_status_t error = bio->bi_status;
977 struct dm_target_io *tio = clone_to_tio(bio);
978 struct dm_io *io = tio->io;
979 struct mapped_device *md = tio->io->md;
980 dm_endio_fn endio = tio->ti->type->end_io;
981 struct request_queue *q = bio->bi_bdev->bd_disk->queue;
983 if (unlikely(error == BLK_STS_TARGET)) {
984 if (bio_op(bio) == REQ_OP_DISCARD &&
985 !q->limits.max_discard_sectors)
987 else if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
988 !q->limits.max_write_zeroes_sectors)
989 disable_write_zeroes(md);
992 if (blk_queue_is_zoned(q))
993 dm_zone_endio(io, bio);
996 int r = endio(tio->ti, bio, &error);
998 case DM_ENDIO_REQUEUE:
1000 * Requeuing writes to a sequential zone of a zoned
1001 * target will break the sequential write pattern:
1004 if (WARN_ON_ONCE(dm_is_zone_write(md, bio)))
1005 error = BLK_STS_IOERR;
1007 error = BLK_STS_DM_REQUEUE;
1011 case DM_ENDIO_INCOMPLETE:
1012 /* The target will handle the io */
1015 DMWARN("unimplemented target endio return value: %d", r);
1020 if (unlikely(swap_bios_limit(tio->ti, bio))) {
1021 struct mapped_device *md = io->md;
1022 up(&md->swap_bios_semaphore);
1026 dm_io_dec_pending(io, error);
1030 * Return maximum size of I/O possible at the supplied sector up to the current
1033 static inline sector_t max_io_len_target_boundary(struct dm_target *ti,
1034 sector_t target_offset)
1036 return ti->len - target_offset;
1039 static sector_t max_io_len(struct dm_target *ti, sector_t sector)
1041 sector_t target_offset = dm_target_offset(ti, sector);
1042 sector_t len = max_io_len_target_boundary(ti, target_offset);
1046 * Does the target need to split IO even further?
1047 * - varied (per target) IO splitting is a tenet of DM; this
1048 * explains why stacked chunk_sectors based splitting via
1049 * blk_max_size_offset() isn't possible here. So pass in
1050 * ti->max_io_len to override stacked chunk_sectors.
1052 if (ti->max_io_len) {
1053 max_len = blk_max_size_offset(ti->table->md->queue,
1054 target_offset, ti->max_io_len);
1062 int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
1064 if (len > UINT_MAX) {
1065 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1066 (unsigned long long)len, UINT_MAX);
1067 ti->error = "Maximum size of target IO is too large";
1071 ti->max_io_len = (uint32_t) len;
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);
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(ti, sector) / 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 int dm_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
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 (WARN_ON(!ti->type->dax_zero_page_range)) {
1137 * ->zero_page_range() is mandatory dax operation. If we are
1138 * here, something is wrong.
1142 ret = ti->type->dax_zero_page_range(ti, pgoff, nr_pages);
1144 dm_put_live_table(md, srcu_idx);
1150 * A target may call dm_accept_partial_bio only from the map routine. It is
1151 * allowed for all bio types except REQ_PREFLUSH, REQ_OP_ZONE_* zone management
1152 * operations, REQ_OP_ZONE_APPEND (zone append writes) and any bio serviced by
1153 * __send_duplicate_bios().
1155 * dm_accept_partial_bio informs the dm that the target only wants to process
1156 * additional n_sectors sectors of the bio and the rest of the data should be
1157 * sent in a next bio.
1159 * A diagram that explains the arithmetics:
1160 * +--------------------+---------------+-------+
1162 * +--------------------+---------------+-------+
1164 * <-------------- *tio->len_ptr --------------->
1165 * <------- bi_size ------->
1168 * Region 1 was already iterated over with bio_advance or similar function.
1169 * (it may be empty if the target doesn't use bio_advance)
1170 * Region 2 is the remaining bio size that the target wants to process.
1171 * (it may be empty if region 1 is non-empty, although there is no reason
1173 * The target requires that region 3 is to be sent in the next bio.
1175 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1176 * the partially processed part (the sum of regions 1+2) must be the same for all
1177 * copies of the bio.
1179 void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
1181 struct dm_target_io *tio = clone_to_tio(bio);
1182 unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
1184 BUG_ON(dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));
1185 BUG_ON(op_is_zone_mgmt(bio_op(bio)));
1186 BUG_ON(bio_op(bio) == REQ_OP_ZONE_APPEND);
1187 BUG_ON(bi_size > *tio->len_ptr);
1188 BUG_ON(n_sectors > bi_size);
1190 *tio->len_ptr -= bi_size - n_sectors;
1191 bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
1193 EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
1195 static inline void __dm_submit_bio_remap(struct bio *clone,
1196 dev_t dev, sector_t old_sector)
1198 trace_block_bio_remap(clone, dev, old_sector);
1199 submit_bio_noacct(clone);
1203 * @clone: clone bio that DM core passed to target's .map function
1204 * @tgt_clone: clone of @clone bio that target needs submitted
1206 * Targets should use this interface to submit bios they take
1207 * ownership of when returning DM_MAPIO_SUBMITTED.
1209 * Target should also enable ti->accounts_remapped_io
1211 void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone)
1213 struct dm_target_io *tio = clone_to_tio(clone);
1214 struct dm_io *io = tio->io;
1216 WARN_ON_ONCE(!tio->ti->accounts_remapped_io);
1218 /* establish bio that will get submitted */
1223 * Account io->origin_bio to DM dev on behalf of target
1224 * that took ownership of IO with DM_MAPIO_SUBMITTED.
1226 if (io->map_task == current) {
1227 /* Still in target's map function */
1228 dm_io_set_flag(io, DM_IO_START_ACCT);
1231 * Called by another thread, managed by DM target,
1232 * wait for dm_split_and_process_bio() to store
1235 while (unlikely(!smp_load_acquire(&io->orig_bio)))
1237 dm_start_io_acct(io, clone);
1240 __dm_submit_bio_remap(tgt_clone, disk_devt(io->md->disk),
1243 EXPORT_SYMBOL_GPL(dm_submit_bio_remap);
1245 static noinline void __set_swap_bios_limit(struct mapped_device *md, int latch)
1247 mutex_lock(&md->swap_bios_lock);
1248 while (latch < md->swap_bios) {
1250 down(&md->swap_bios_semaphore);
1253 while (latch > md->swap_bios) {
1255 up(&md->swap_bios_semaphore);
1258 mutex_unlock(&md->swap_bios_lock);
1261 static void __map_bio(struct bio *clone)
1263 struct dm_target_io *tio = clone_to_tio(clone);
1265 struct dm_io *io = tio->io;
1266 struct dm_target *ti = tio->ti;
1268 clone->bi_end_io = clone_endio;
1273 dm_io_inc_pending(io);
1274 tio->old_sector = clone->bi_iter.bi_sector;
1276 if (unlikely(swap_bios_limit(ti, clone))) {
1277 struct mapped_device *md = io->md;
1278 int latch = get_swap_bios();
1279 if (unlikely(latch != md->swap_bios))
1280 __set_swap_bios_limit(md, latch);
1281 down(&md->swap_bios_semaphore);
1285 * Check if the IO needs a special mapping due to zone append emulation
1286 * on zoned target. In this case, dm_zone_map_bio() calls the target
1289 if (dm_emulate_zone_append(io->md))
1290 r = dm_zone_map_bio(tio);
1292 r = ti->type->map(ti, clone);
1295 case DM_MAPIO_SUBMITTED:
1296 /* target has assumed ownership of this io */
1297 if (!ti->accounts_remapped_io)
1298 dm_io_set_flag(io, DM_IO_START_ACCT);
1300 case DM_MAPIO_REMAPPED:
1302 * the bio has been remapped so dispatch it, but defer
1303 * dm_start_io_acct() until after possible bio_split().
1305 __dm_submit_bio_remap(clone, disk_devt(io->md->disk),
1307 dm_io_set_flag(io, DM_IO_START_ACCT);
1310 case DM_MAPIO_REQUEUE:
1311 if (unlikely(swap_bios_limit(ti, clone)))
1312 up(&io->md->swap_bios_semaphore);
1314 if (r == DM_MAPIO_KILL)
1315 dm_io_dec_pending(io, BLK_STS_IOERR);
1317 dm_io_dec_pending(io, BLK_STS_DM_REQUEUE);
1320 DMWARN("unimplemented target map return value: %d", r);
1325 static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci,
1326 struct dm_target *ti, unsigned num_bios,
1332 for (try = 0; try < 2; try++) {
1336 mutex_lock(&ci->io->md->table_devices_lock);
1337 for (bio_nr = 0; bio_nr < num_bios; bio_nr++) {
1338 bio = alloc_tio(ci, ti, bio_nr, len,
1339 try ? GFP_NOIO : GFP_NOWAIT);
1343 bio_list_add(blist, bio);
1346 mutex_unlock(&ci->io->md->table_devices_lock);
1347 if (bio_nr == num_bios)
1350 while ((bio = bio_list_pop(blist)))
1355 static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
1356 unsigned num_bios, unsigned *len)
1358 struct bio_list blist = BIO_EMPTY_LIST;
1365 clone = alloc_tio(ci, ti, 0, len, GFP_NOIO);
1366 dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO);
1370 alloc_multiple_bios(&blist, ci, ti, num_bios, len);
1371 while ((clone = bio_list_pop(&blist))) {
1372 dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO);
1379 static void __send_empty_flush(struct clone_info *ci)
1381 unsigned target_nr = 0;
1382 struct dm_target *ti;
1383 struct bio flush_bio;
1386 * Use an on-stack bio for this, it's safe since we don't
1387 * need to reference it after submit. It's just used as
1388 * the basis for the clone(s).
1390 bio_init(&flush_bio, ci->io->md->disk->part0, NULL, 0,
1391 REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC);
1393 ci->bio = &flush_bio;
1394 ci->sector_count = 0;
1396 while ((ti = dm_table_get_target(ci->map, target_nr++)))
1397 __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
1399 bio_uninit(ci->bio);
1402 static void __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti,
1407 len = min_t(sector_t, ci->sector_count,
1408 max_io_len_target_boundary(ti, dm_target_offset(ti, ci->sector)));
1411 * dm_accept_partial_bio cannot be used with duplicate bios,
1412 * so update clone_info cursor before __send_duplicate_bios().
1415 ci->sector_count -= len;
1417 __send_duplicate_bios(ci, ti, num_bios, &len);
1420 static bool is_abnormal_io(struct bio *bio)
1424 switch (bio_op(bio)) {
1425 case REQ_OP_DISCARD:
1426 case REQ_OP_SECURE_ERASE:
1427 case REQ_OP_WRITE_ZEROES:
1435 static bool __process_abnormal_io(struct clone_info *ci, struct dm_target *ti,
1438 unsigned num_bios = 0;
1440 switch (bio_op(ci->bio)) {
1441 case REQ_OP_DISCARD:
1442 num_bios = ti->num_discard_bios;
1444 case REQ_OP_SECURE_ERASE:
1445 num_bios = ti->num_secure_erase_bios;
1447 case REQ_OP_WRITE_ZEROES:
1448 num_bios = ti->num_write_zeroes_bios;
1455 * Even though the device advertised support for this type of
1456 * request, that does not mean every target supports it, and
1457 * reconfiguration might also have changed that since the
1458 * check was performed.
1461 *result = -EOPNOTSUPP;
1463 __send_changing_extent_only(ci, ti, num_bios);
1470 * Reuse ->bi_private as hlist head for storing all dm_io instances
1471 * associated with this bio, and this bio's bi_private needs to be
1472 * stored in dm_io->data before the reuse.
1474 * bio->bi_private is owned by fs or upper layer, so block layer won't
1475 * touch it after splitting. Meantime it won't be changed by anyone after
1476 * bio is submitted. So this reuse is safe.
1478 static inline struct hlist_head *dm_get_bio_hlist_head(struct bio *bio)
1480 return (struct hlist_head *)&bio->bi_private;
1483 static void dm_queue_poll_io(struct bio *bio, struct dm_io *io)
1485 struct hlist_head *head = dm_get_bio_hlist_head(bio);
1487 if (!(bio->bi_opf & REQ_DM_POLL_LIST)) {
1488 bio->bi_opf |= REQ_DM_POLL_LIST;
1490 * Save .bi_private into dm_io, so that we can reuse
1491 * .bi_private as hlist head for storing dm_io list
1493 io->data = bio->bi_private;
1495 INIT_HLIST_HEAD(head);
1497 /* tell block layer to poll for completion */
1498 bio->bi_cookie = ~BLK_QC_T_NONE;
1501 * bio recursed due to split, reuse original poll list,
1502 * and save bio->bi_private too.
1504 io->data = hlist_entry(head->first, struct dm_io, node)->data;
1507 hlist_add_head(&io->node, head);
1511 * Select the correct strategy for processing a non-flush bio.
1513 static int __split_and_process_bio(struct clone_info *ci)
1516 struct dm_target *ti;
1520 ti = dm_table_find_target(ci->map, ci->sector);
1524 if (__process_abnormal_io(ci, ti, &r))
1528 * Only support bio polling for normal IO, and the target io is
1529 * exactly inside the dm_io instance (verified in dm_poll_dm_io)
1531 ci->submit_as_polled = ci->bio->bi_opf & REQ_POLLED;
1533 len = min_t(sector_t, max_io_len(ti, ci->sector), ci->sector_count);
1534 clone = alloc_tio(ci, ti, 0, &len, GFP_NOIO);
1538 ci->sector_count -= len;
1543 static void init_clone_info(struct clone_info *ci, struct mapped_device *md,
1544 struct dm_table *map, struct bio *bio)
1547 ci->io = alloc_io(md, bio);
1549 ci->submit_as_polled = false;
1550 ci->sector = bio->bi_iter.bi_sector;
1551 ci->sector_count = bio_sectors(bio);
1553 /* Shouldn't happen but sector_count was being set to 0 so... */
1554 if (WARN_ON_ONCE(op_is_zone_mgmt(bio_op(bio)) && ci->sector_count))
1555 ci->sector_count = 0;
1559 * Entry point to split a bio into clones and submit them to the targets.
1561 static void dm_split_and_process_bio(struct mapped_device *md,
1562 struct dm_table *map, struct bio *bio)
1564 struct clone_info ci;
1565 struct bio *orig_bio = NULL;
1568 init_clone_info(&ci, md, map, bio);
1570 if (bio->bi_opf & REQ_PREFLUSH) {
1571 __send_empty_flush(&ci);
1572 /* dm_io_complete submits any data associated with flush */
1576 error = __split_and_process_bio(&ci);
1577 ci.io->map_task = NULL;
1578 if (error || !ci.sector_count)
1582 * Remainder must be passed to submit_bio_noacct() so it gets handled
1583 * *after* bios already submitted have been completely processed.
1584 * We take a clone of the original to store in ci.io->orig_bio to be
1585 * used by dm_end_io_acct() and for dm_io_complete() to use for
1586 * completion handling.
1588 orig_bio = bio_split(bio, bio_sectors(bio) - ci.sector_count,
1589 GFP_NOIO, &md->queue->bio_split);
1590 bio_chain(orig_bio, bio);
1591 trace_block_split(orig_bio, bio->bi_iter.bi_sector);
1592 submit_bio_noacct(bio);
1596 smp_store_release(&ci.io->orig_bio, orig_bio);
1597 if (dm_io_flagged(ci.io, DM_IO_START_ACCT))
1598 dm_start_io_acct(ci.io, NULL);
1601 * Drop the extra reference count for non-POLLED bio, and hold one
1602 * reference for POLLED bio, which will be released in dm_poll_bio
1604 * Add every dm_io instance into the hlist_head which is stored in
1605 * bio->bi_private, so that dm_poll_bio can poll them all.
1607 if (error || !ci.submit_as_polled)
1608 dm_io_dec_pending(ci.io, errno_to_blk_status(error));
1610 dm_queue_poll_io(bio, ci.io);
1613 static void dm_submit_bio(struct bio *bio)
1615 struct mapped_device *md = bio->bi_bdev->bd_disk->private_data;
1617 struct dm_table *map;
1619 map = dm_get_live_table(md, &srcu_idx);
1621 /* If suspended, or map not yet available, queue this IO for later */
1622 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) ||
1624 if (bio->bi_opf & REQ_NOWAIT)
1625 bio_wouldblock_error(bio);
1626 else if (bio->bi_opf & REQ_RAHEAD)
1634 * Use blk_queue_split() for abnormal IO (e.g. discard, writesame, etc)
1635 * otherwise associated queue_limits won't be imposed.
1637 if (is_abnormal_io(bio))
1638 blk_queue_split(&bio);
1640 dm_split_and_process_bio(md, map, bio);
1642 dm_put_live_table(md, srcu_idx);
1645 static bool dm_poll_dm_io(struct dm_io *io, struct io_comp_batch *iob,
1648 WARN_ON_ONCE(!dm_tio_is_normal(&io->tio));
1650 /* don't poll if the mapped io is done */
1651 if (atomic_read(&io->io_count) > 1)
1652 bio_poll(&io->tio.clone, iob, flags);
1654 /* bio_poll holds the last reference */
1655 return atomic_read(&io->io_count) == 1;
1658 static int dm_poll_bio(struct bio *bio, struct io_comp_batch *iob,
1661 struct hlist_head *head = dm_get_bio_hlist_head(bio);
1662 struct hlist_head tmp = HLIST_HEAD_INIT;
1663 struct hlist_node *next;
1666 /* Only poll normal bio which was marked as REQ_DM_POLL_LIST */
1667 if (!(bio->bi_opf & REQ_DM_POLL_LIST))
1670 WARN_ON_ONCE(hlist_empty(head));
1672 hlist_move_list(head, &tmp);
1675 * Restore .bi_private before possibly completing dm_io.
1677 * bio_poll() is only possible once @bio has been completely
1678 * submitted via submit_bio_noacct()'s depth-first submission.
1679 * So there is no dm_queue_poll_io() race associated with
1680 * clearing REQ_DM_POLL_LIST here.
1682 bio->bi_opf &= ~REQ_DM_POLL_LIST;
1683 bio->bi_private = hlist_entry(tmp.first, struct dm_io, node)->data;
1685 hlist_for_each_entry_safe(io, next, &tmp, node) {
1686 if (dm_poll_dm_io(io, iob, flags)) {
1687 hlist_del_init(&io->node);
1689 * clone_endio() has already occurred, so passing
1690 * error as 0 here doesn't override io->status
1692 dm_io_dec_pending(io, 0);
1697 if (!hlist_empty(&tmp)) {
1698 bio->bi_opf |= REQ_DM_POLL_LIST;
1699 /* Reset bio->bi_private to dm_io list head */
1700 hlist_move_list(&tmp, head);
1706 /*-----------------------------------------------------------------
1707 * An IDR is used to keep track of allocated minor numbers.
1708 *---------------------------------------------------------------*/
1709 static void free_minor(int minor)
1711 spin_lock(&_minor_lock);
1712 idr_remove(&_minor_idr, minor);
1713 spin_unlock(&_minor_lock);
1717 * See if the device with a specific minor # is free.
1719 static int specific_minor(int minor)
1723 if (minor >= (1 << MINORBITS))
1726 idr_preload(GFP_KERNEL);
1727 spin_lock(&_minor_lock);
1729 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
1731 spin_unlock(&_minor_lock);
1734 return r == -ENOSPC ? -EBUSY : r;
1738 static int next_free_minor(int *minor)
1742 idr_preload(GFP_KERNEL);
1743 spin_lock(&_minor_lock);
1745 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
1747 spin_unlock(&_minor_lock);
1755 static const struct block_device_operations dm_blk_dops;
1756 static const struct block_device_operations dm_rq_blk_dops;
1757 static const struct dax_operations dm_dax_ops;
1759 static void dm_wq_work(struct work_struct *work);
1761 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1762 static void dm_queue_destroy_crypto_profile(struct request_queue *q)
1764 dm_destroy_crypto_profile(q->crypto_profile);
1767 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1769 static inline void dm_queue_destroy_crypto_profile(struct request_queue *q)
1772 #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1774 static void cleanup_mapped_device(struct mapped_device *md)
1777 destroy_workqueue(md->wq);
1778 bioset_exit(&md->bs);
1779 bioset_exit(&md->io_bs);
1782 dax_remove_host(md->disk);
1783 kill_dax(md->dax_dev);
1784 put_dax(md->dax_dev);
1788 dm_cleanup_zoned_dev(md);
1790 spin_lock(&_minor_lock);
1791 md->disk->private_data = NULL;
1792 spin_unlock(&_minor_lock);
1793 if (dm_get_md_type(md) != DM_TYPE_NONE) {
1795 del_gendisk(md->disk);
1797 dm_queue_destroy_crypto_profile(md->queue);
1798 blk_cleanup_disk(md->disk);
1801 if (md->pending_io) {
1802 free_percpu(md->pending_io);
1803 md->pending_io = NULL;
1806 cleanup_srcu_struct(&md->io_barrier);
1808 mutex_destroy(&md->suspend_lock);
1809 mutex_destroy(&md->type_lock);
1810 mutex_destroy(&md->table_devices_lock);
1811 mutex_destroy(&md->swap_bios_lock);
1813 dm_mq_cleanup_mapped_device(md);
1817 * Allocate and initialise a blank device with a given minor.
1819 static struct mapped_device *alloc_dev(int minor)
1821 int r, numa_node_id = dm_get_numa_node();
1822 struct mapped_device *md;
1825 md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
1827 DMWARN("unable to allocate device, out of memory.");
1831 if (!try_module_get(THIS_MODULE))
1832 goto bad_module_get;
1834 /* get a minor number for the dev */
1835 if (minor == DM_ANY_MINOR)
1836 r = next_free_minor(&minor);
1838 r = specific_minor(minor);
1842 r = init_srcu_struct(&md->io_barrier);
1844 goto bad_io_barrier;
1846 md->numa_node_id = numa_node_id;
1847 md->init_tio_pdu = false;
1848 md->type = DM_TYPE_NONE;
1849 mutex_init(&md->suspend_lock);
1850 mutex_init(&md->type_lock);
1851 mutex_init(&md->table_devices_lock);
1852 spin_lock_init(&md->deferred_lock);
1853 atomic_set(&md->holders, 1);
1854 atomic_set(&md->open_count, 0);
1855 atomic_set(&md->event_nr, 0);
1856 atomic_set(&md->uevent_seq, 0);
1857 INIT_LIST_HEAD(&md->uevent_list);
1858 INIT_LIST_HEAD(&md->table_devices);
1859 spin_lock_init(&md->uevent_lock);
1862 * default to bio-based until DM table is loaded and md->type
1863 * established. If request-based table is loaded: blk-mq will
1864 * override accordingly.
1866 md->disk = blk_alloc_disk(md->numa_node_id);
1869 md->queue = md->disk->queue;
1871 init_waitqueue_head(&md->wait);
1872 INIT_WORK(&md->work, dm_wq_work);
1873 init_waitqueue_head(&md->eventq);
1874 init_completion(&md->kobj_holder.completion);
1876 md->swap_bios = get_swap_bios();
1877 sema_init(&md->swap_bios_semaphore, md->swap_bios);
1878 mutex_init(&md->swap_bios_lock);
1880 md->disk->major = _major;
1881 md->disk->first_minor = minor;
1882 md->disk->minors = 1;
1883 md->disk->flags |= GENHD_FL_NO_PART;
1884 md->disk->fops = &dm_blk_dops;
1885 md->disk->queue = md->queue;
1886 md->disk->private_data = md;
1887 sprintf(md->disk->disk_name, "dm-%d", minor);
1889 if (IS_ENABLED(CONFIG_FS_DAX)) {
1890 md->dax_dev = alloc_dax(md, &dm_dax_ops);
1891 if (IS_ERR(md->dax_dev)) {
1895 set_dax_nocache(md->dax_dev);
1896 set_dax_nomc(md->dax_dev);
1897 if (dax_add_host(md->dax_dev, md->disk))
1901 format_dev_t(md->name, MKDEV(_major, minor));
1903 md->wq = alloc_workqueue("kdmflush/%s", WQ_MEM_RECLAIM, 0, md->name);
1907 md->pending_io = alloc_percpu(unsigned long);
1908 if (!md->pending_io)
1911 dm_stats_init(&md->stats);
1913 /* Populate the mapping, nobody knows we exist yet */
1914 spin_lock(&_minor_lock);
1915 old_md = idr_replace(&_minor_idr, md, minor);
1916 spin_unlock(&_minor_lock);
1918 BUG_ON(old_md != MINOR_ALLOCED);
1923 cleanup_mapped_device(md);
1927 module_put(THIS_MODULE);
1933 static void unlock_fs(struct mapped_device *md);
1935 static void free_dev(struct mapped_device *md)
1937 int minor = MINOR(disk_devt(md->disk));
1941 cleanup_mapped_device(md);
1943 free_table_devices(&md->table_devices);
1944 dm_stats_cleanup(&md->stats);
1947 module_put(THIS_MODULE);
1951 static int __bind_mempools(struct mapped_device *md, struct dm_table *t)
1953 struct dm_md_mempools *p = dm_table_get_md_mempools(t);
1956 if (dm_table_bio_based(t)) {
1958 * The md may already have mempools that need changing.
1959 * If so, reload bioset because front_pad may have changed
1960 * because a different table was loaded.
1962 bioset_exit(&md->bs);
1963 bioset_exit(&md->io_bs);
1965 } else if (bioset_initialized(&md->bs)) {
1967 * There's no need to reload with request-based dm
1968 * because the size of front_pad doesn't change.
1969 * Note for future: If you are to reload bioset,
1970 * prep-ed requests in the queue may refer
1971 * to bio from the old bioset, so you must walk
1972 * through the queue to unprep.
1978 bioset_initialized(&md->bs) ||
1979 bioset_initialized(&md->io_bs));
1981 ret = bioset_init_from_src(&md->bs, &p->bs);
1984 ret = bioset_init_from_src(&md->io_bs, &p->io_bs);
1986 bioset_exit(&md->bs);
1988 /* mempool bind completed, no longer need any mempools in the table */
1989 dm_table_free_md_mempools(t);
1994 * Bind a table to the device.
1996 static void event_callback(void *context)
1998 unsigned long flags;
2000 struct mapped_device *md = (struct mapped_device *) context;
2002 spin_lock_irqsave(&md->uevent_lock, flags);
2003 list_splice_init(&md->uevent_list, &uevents);
2004 spin_unlock_irqrestore(&md->uevent_lock, flags);
2006 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
2008 atomic_inc(&md->event_nr);
2009 wake_up(&md->eventq);
2010 dm_issue_global_event();
2014 * Returns old map, which caller must destroy.
2016 static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
2017 struct queue_limits *limits)
2019 struct dm_table *old_map;
2023 lockdep_assert_held(&md->suspend_lock);
2025 size = dm_table_get_size(t);
2028 * Wipe any geometry if the size of the table changed.
2030 if (size != dm_get_size(md))
2031 memset(&md->geometry, 0, sizeof(md->geometry));
2033 if (!get_capacity(md->disk))
2034 set_capacity(md->disk, size);
2036 set_capacity_and_notify(md->disk, size);
2038 dm_table_event_callback(t, event_callback, md);
2040 if (dm_table_request_based(t)) {
2042 * Leverage the fact that request-based DM targets are
2043 * immutable singletons - used to optimize dm_mq_queue_rq.
2045 md->immutable_target = dm_table_get_immutable_target(t);
2048 ret = __bind_mempools(md, t);
2050 old_map = ERR_PTR(ret);
2054 ret = dm_table_set_restrictions(t, md->queue, limits);
2056 old_map = ERR_PTR(ret);
2060 old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2061 rcu_assign_pointer(md->map, (void *)t);
2062 md->immutable_target_type = dm_table_get_immutable_target_type(t);
2071 * Returns unbound table for the caller to free.
2073 static struct dm_table *__unbind(struct mapped_device *md)
2075 struct dm_table *map = rcu_dereference_protected(md->map, 1);
2080 dm_table_event_callback(map, NULL, NULL);
2081 RCU_INIT_POINTER(md->map, NULL);
2088 * Constructor for a new device.
2090 int dm_create(int minor, struct mapped_device **result)
2092 struct mapped_device *md;
2094 md = alloc_dev(minor);
2098 dm_ima_reset_data(md);
2105 * Functions to manage md->type.
2106 * All are required to hold md->type_lock.
2108 void dm_lock_md_type(struct mapped_device *md)
2110 mutex_lock(&md->type_lock);
2113 void dm_unlock_md_type(struct mapped_device *md)
2115 mutex_unlock(&md->type_lock);
2118 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type)
2120 BUG_ON(!mutex_is_locked(&md->type_lock));
2124 enum dm_queue_mode dm_get_md_type(struct mapped_device *md)
2129 struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
2131 return md->immutable_target_type;
2135 * The queue_limits are only valid as long as you have a reference
2138 struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
2140 BUG_ON(!atomic_read(&md->holders));
2141 return &md->queue->limits;
2143 EXPORT_SYMBOL_GPL(dm_get_queue_limits);
2146 * Setup the DM device's queue based on md's type
2148 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
2150 enum dm_queue_mode type = dm_table_get_type(t);
2151 struct queue_limits limits;
2155 case DM_TYPE_REQUEST_BASED:
2156 md->disk->fops = &dm_rq_blk_dops;
2157 r = dm_mq_init_request_queue(md, t);
2159 DMERR("Cannot initialize queue for request-based dm mapped device");
2163 case DM_TYPE_BIO_BASED:
2164 case DM_TYPE_DAX_BIO_BASED:
2171 r = dm_calculate_queue_limits(t, &limits);
2173 DMERR("Cannot calculate initial queue limits");
2176 r = dm_table_set_restrictions(t, md->queue, &limits);
2180 r = add_disk(md->disk);
2184 r = dm_sysfs_init(md);
2186 del_gendisk(md->disk);
2193 struct mapped_device *dm_get_md(dev_t dev)
2195 struct mapped_device *md;
2196 unsigned minor = MINOR(dev);
2198 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
2201 spin_lock(&_minor_lock);
2203 md = idr_find(&_minor_idr, minor);
2204 if (!md || md == MINOR_ALLOCED || (MINOR(disk_devt(dm_disk(md))) != minor) ||
2205 test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
2211 spin_unlock(&_minor_lock);
2215 EXPORT_SYMBOL_GPL(dm_get_md);
2217 void *dm_get_mdptr(struct mapped_device *md)
2219 return md->interface_ptr;
2222 void dm_set_mdptr(struct mapped_device *md, void *ptr)
2224 md->interface_ptr = ptr;
2227 void dm_get(struct mapped_device *md)
2229 atomic_inc(&md->holders);
2230 BUG_ON(test_bit(DMF_FREEING, &md->flags));
2233 int dm_hold(struct mapped_device *md)
2235 spin_lock(&_minor_lock);
2236 if (test_bit(DMF_FREEING, &md->flags)) {
2237 spin_unlock(&_minor_lock);
2241 spin_unlock(&_minor_lock);
2244 EXPORT_SYMBOL_GPL(dm_hold);
2246 const char *dm_device_name(struct mapped_device *md)
2250 EXPORT_SYMBOL_GPL(dm_device_name);
2252 static void __dm_destroy(struct mapped_device *md, bool wait)
2254 struct dm_table *map;
2259 spin_lock(&_minor_lock);
2260 idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
2261 set_bit(DMF_FREEING, &md->flags);
2262 spin_unlock(&_minor_lock);
2264 blk_mark_disk_dead(md->disk);
2267 * Take suspend_lock so that presuspend and postsuspend methods
2268 * do not race with internal suspend.
2270 mutex_lock(&md->suspend_lock);
2271 map = dm_get_live_table(md, &srcu_idx);
2272 if (!dm_suspended_md(md)) {
2273 dm_table_presuspend_targets(map);
2274 set_bit(DMF_SUSPENDED, &md->flags);
2275 set_bit(DMF_POST_SUSPENDING, &md->flags);
2276 dm_table_postsuspend_targets(map);
2278 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2279 dm_put_live_table(md, srcu_idx);
2280 mutex_unlock(&md->suspend_lock);
2283 * Rare, but there may be I/O requests still going to complete,
2284 * for example. Wait for all references to disappear.
2285 * No one should increment the reference count of the mapped_device,
2286 * after the mapped_device state becomes DMF_FREEING.
2289 while (atomic_read(&md->holders))
2291 else if (atomic_read(&md->holders))
2292 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2293 dm_device_name(md), atomic_read(&md->holders));
2295 dm_table_destroy(__unbind(md));
2299 void dm_destroy(struct mapped_device *md)
2301 __dm_destroy(md, true);
2304 void dm_destroy_immediate(struct mapped_device *md)
2306 __dm_destroy(md, false);
2309 void dm_put(struct mapped_device *md)
2311 atomic_dec(&md->holders);
2313 EXPORT_SYMBOL_GPL(dm_put);
2315 static bool dm_in_flight_bios(struct mapped_device *md)
2318 unsigned long sum = 0;
2320 for_each_possible_cpu(cpu)
2321 sum += *per_cpu_ptr(md->pending_io, cpu);
2326 static int dm_wait_for_bios_completion(struct mapped_device *md, unsigned int task_state)
2332 prepare_to_wait(&md->wait, &wait, task_state);
2334 if (!dm_in_flight_bios(md))
2337 if (signal_pending_state(task_state, current)) {
2344 finish_wait(&md->wait, &wait);
2351 static int dm_wait_for_completion(struct mapped_device *md, unsigned int task_state)
2355 if (!queue_is_mq(md->queue))
2356 return dm_wait_for_bios_completion(md, task_state);
2359 if (!blk_mq_queue_inflight(md->queue))
2362 if (signal_pending_state(task_state, current)) {
2374 * Process the deferred bios
2376 static void dm_wq_work(struct work_struct *work)
2378 struct mapped_device *md = container_of(work, struct mapped_device, work);
2381 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
2382 spin_lock_irq(&md->deferred_lock);
2383 bio = bio_list_pop(&md->deferred);
2384 spin_unlock_irq(&md->deferred_lock);
2389 submit_bio_noacct(bio);
2393 static void dm_queue_flush(struct mapped_device *md)
2395 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2396 smp_mb__after_atomic();
2397 queue_work(md->wq, &md->work);
2401 * Swap in a new table, returning the old one for the caller to destroy.
2403 struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
2405 struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
2406 struct queue_limits limits;
2409 mutex_lock(&md->suspend_lock);
2411 /* device must be suspended */
2412 if (!dm_suspended_md(md))
2416 * If the new table has no data devices, retain the existing limits.
2417 * This helps multipath with queue_if_no_path if all paths disappear,
2418 * then new I/O is queued based on these limits, and then some paths
2421 if (dm_table_has_no_data_devices(table)) {
2422 live_map = dm_get_live_table_fast(md);
2424 limits = md->queue->limits;
2425 dm_put_live_table_fast(md);
2429 r = dm_calculate_queue_limits(table, &limits);
2436 map = __bind(md, table, &limits);
2437 dm_issue_global_event();
2440 mutex_unlock(&md->suspend_lock);
2445 * Functions to lock and unlock any filesystem running on the
2448 static int lock_fs(struct mapped_device *md)
2452 WARN_ON(test_bit(DMF_FROZEN, &md->flags));
2454 r = freeze_bdev(md->disk->part0);
2456 set_bit(DMF_FROZEN, &md->flags);
2460 static void unlock_fs(struct mapped_device *md)
2462 if (!test_bit(DMF_FROZEN, &md->flags))
2464 thaw_bdev(md->disk->part0);
2465 clear_bit(DMF_FROZEN, &md->flags);
2469 * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG
2470 * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE
2471 * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY
2473 * If __dm_suspend returns 0, the device is completely quiescent
2474 * now. There is no request-processing activity. All new requests
2475 * are being added to md->deferred list.
2477 static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
2478 unsigned suspend_flags, unsigned int task_state,
2479 int dmf_suspended_flag)
2481 bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
2482 bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
2485 lockdep_assert_held(&md->suspend_lock);
2488 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2489 * This flag is cleared before dm_suspend returns.
2492 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2494 DMDEBUG("%s: suspending with flush", dm_device_name(md));
2497 * This gets reverted if there's an error later and the targets
2498 * provide the .presuspend_undo hook.
2500 dm_table_presuspend_targets(map);
2503 * Flush I/O to the device.
2504 * Any I/O submitted after lock_fs() may not be flushed.
2505 * noflush takes precedence over do_lockfs.
2506 * (lock_fs() flushes I/Os and waits for them to complete.)
2508 if (!noflush && do_lockfs) {
2511 dm_table_presuspend_undo_targets(map);
2517 * Here we must make sure that no processes are submitting requests
2518 * to target drivers i.e. no one may be executing
2519 * dm_split_and_process_bio from dm_submit_bio.
2521 * To get all processes out of dm_split_and_process_bio in dm_submit_bio,
2522 * we take the write lock. To prevent any process from reentering
2523 * dm_split_and_process_bio from dm_submit_bio and quiesce the thread
2524 * (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND and call
2525 * flush_workqueue(md->wq).
2527 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2529 synchronize_srcu(&md->io_barrier);
2532 * Stop md->queue before flushing md->wq in case request-based
2533 * dm defers requests to md->wq from md->queue.
2535 if (dm_request_based(md))
2536 dm_stop_queue(md->queue);
2538 flush_workqueue(md->wq);
2541 * At this point no more requests are entering target request routines.
2542 * We call dm_wait_for_completion to wait for all existing requests
2545 r = dm_wait_for_completion(md, task_state);
2547 set_bit(dmf_suspended_flag, &md->flags);
2550 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2552 synchronize_srcu(&md->io_barrier);
2554 /* were we interrupted ? */
2558 if (dm_request_based(md))
2559 dm_start_queue(md->queue);
2562 dm_table_presuspend_undo_targets(map);
2563 /* pushback list is already flushed, so skip flush */
2570 * We need to be able to change a mapping table under a mounted
2571 * filesystem. For example we might want to move some data in
2572 * the background. Before the table can be swapped with
2573 * dm_bind_table, dm_suspend must be called to flush any in
2574 * flight bios and ensure that any further io gets deferred.
2577 * Suspend mechanism in request-based dm.
2579 * 1. Flush all I/Os by lock_fs() if needed.
2580 * 2. Stop dispatching any I/O by stopping the request_queue.
2581 * 3. Wait for all in-flight I/Os to be completed or requeued.
2583 * To abort suspend, start the request_queue.
2585 int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
2587 struct dm_table *map = NULL;
2591 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2593 if (dm_suspended_md(md)) {
2598 if (dm_suspended_internally_md(md)) {
2599 /* already internally suspended, wait for internal resume */
2600 mutex_unlock(&md->suspend_lock);
2601 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2607 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2609 r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);
2613 set_bit(DMF_POST_SUSPENDING, &md->flags);
2614 dm_table_postsuspend_targets(map);
2615 clear_bit(DMF_POST_SUSPENDING, &md->flags);
2618 mutex_unlock(&md->suspend_lock);
2622 static int __dm_resume(struct mapped_device *md, struct dm_table *map)
2625 int r = dm_table_resume_targets(map);
2633 * Flushing deferred I/Os must be done after targets are resumed
2634 * so that mapping of targets can work correctly.
2635 * Request-based dm is queueing the deferred I/Os in its request_queue.
2637 if (dm_request_based(md))
2638 dm_start_queue(md->queue);
2645 int dm_resume(struct mapped_device *md)
2648 struct dm_table *map = NULL;
2652 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2654 if (!dm_suspended_md(md))
2657 if (dm_suspended_internally_md(md)) {
2658 /* already internally suspended, wait for internal resume */
2659 mutex_unlock(&md->suspend_lock);
2660 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2666 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2667 if (!map || !dm_table_get_size(map))
2670 r = __dm_resume(md, map);
2674 clear_bit(DMF_SUSPENDED, &md->flags);
2676 mutex_unlock(&md->suspend_lock);
2682 * Internal suspend/resume works like userspace-driven suspend. It waits
2683 * until all bios finish and prevents issuing new bios to the target drivers.
2684 * It may be used only from the kernel.
2687 static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
2689 struct dm_table *map = NULL;
2691 lockdep_assert_held(&md->suspend_lock);
2693 if (md->internal_suspend_count++)
2694 return; /* nested internal suspend */
2696 if (dm_suspended_md(md)) {
2697 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2698 return; /* nest suspend */
2701 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2704 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
2705 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
2706 * would require changing .presuspend to return an error -- avoid this
2707 * until there is a need for more elaborate variants of internal suspend.
2709 (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
2710 DMF_SUSPENDED_INTERNALLY);
2712 set_bit(DMF_POST_SUSPENDING, &md->flags);
2713 dm_table_postsuspend_targets(map);
2714 clear_bit(DMF_POST_SUSPENDING, &md->flags);
2717 static void __dm_internal_resume(struct mapped_device *md)
2719 BUG_ON(!md->internal_suspend_count);
2721 if (--md->internal_suspend_count)
2722 return; /* resume from nested internal suspend */
2724 if (dm_suspended_md(md))
2725 goto done; /* resume from nested suspend */
2728 * NOTE: existing callers don't need to call dm_table_resume_targets
2729 * (which may fail -- so best to avoid it for now by passing NULL map)
2731 (void) __dm_resume(md, NULL);
2734 clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2735 smp_mb__after_atomic();
2736 wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
2739 void dm_internal_suspend_noflush(struct mapped_device *md)
2741 mutex_lock(&md->suspend_lock);
2742 __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
2743 mutex_unlock(&md->suspend_lock);
2745 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
2747 void dm_internal_resume(struct mapped_device *md)
2749 mutex_lock(&md->suspend_lock);
2750 __dm_internal_resume(md);
2751 mutex_unlock(&md->suspend_lock);
2753 EXPORT_SYMBOL_GPL(dm_internal_resume);
2756 * Fast variants of internal suspend/resume hold md->suspend_lock,
2757 * which prevents interaction with userspace-driven suspend.
2760 void dm_internal_suspend_fast(struct mapped_device *md)
2762 mutex_lock(&md->suspend_lock);
2763 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2766 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2767 synchronize_srcu(&md->io_barrier);
2768 flush_workqueue(md->wq);
2769 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
2771 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
2773 void dm_internal_resume_fast(struct mapped_device *md)
2775 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2781 mutex_unlock(&md->suspend_lock);
2783 EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
2785 /*-----------------------------------------------------------------
2786 * Event notification.
2787 *---------------------------------------------------------------*/
2788 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
2793 char udev_cookie[DM_COOKIE_LENGTH];
2794 char *envp[] = { udev_cookie, NULL };
2796 noio_flag = memalloc_noio_save();
2799 r = kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
2801 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
2802 DM_COOKIE_ENV_VAR_NAME, cookie);
2803 r = kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
2807 memalloc_noio_restore(noio_flag);
2812 uint32_t dm_next_uevent_seq(struct mapped_device *md)
2814 return atomic_add_return(1, &md->uevent_seq);
2817 uint32_t dm_get_event_nr(struct mapped_device *md)
2819 return atomic_read(&md->event_nr);
2822 int dm_wait_event(struct mapped_device *md, int event_nr)
2824 return wait_event_interruptible(md->eventq,
2825 (event_nr != atomic_read(&md->event_nr)));
2828 void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
2830 unsigned long flags;
2832 spin_lock_irqsave(&md->uevent_lock, flags);
2833 list_add(elist, &md->uevent_list);
2834 spin_unlock_irqrestore(&md->uevent_lock, flags);
2838 * The gendisk is only valid as long as you have a reference
2841 struct gendisk *dm_disk(struct mapped_device *md)
2845 EXPORT_SYMBOL_GPL(dm_disk);
2847 struct kobject *dm_kobject(struct mapped_device *md)
2849 return &md->kobj_holder.kobj;
2852 struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
2854 struct mapped_device *md;
2856 md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
2858 spin_lock(&_minor_lock);
2859 if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
2865 spin_unlock(&_minor_lock);
2870 int dm_suspended_md(struct mapped_device *md)
2872 return test_bit(DMF_SUSPENDED, &md->flags);
2875 static int dm_post_suspending_md(struct mapped_device *md)
2877 return test_bit(DMF_POST_SUSPENDING, &md->flags);
2880 int dm_suspended_internally_md(struct mapped_device *md)
2882 return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2885 int dm_test_deferred_remove_flag(struct mapped_device *md)
2887 return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
2890 int dm_suspended(struct dm_target *ti)
2892 return dm_suspended_md(ti->table->md);
2894 EXPORT_SYMBOL_GPL(dm_suspended);
2896 int dm_post_suspending(struct dm_target *ti)
2898 return dm_post_suspending_md(ti->table->md);
2900 EXPORT_SYMBOL_GPL(dm_post_suspending);
2902 int dm_noflush_suspending(struct dm_target *ti)
2904 return __noflush_suspending(ti->table->md);
2906 EXPORT_SYMBOL_GPL(dm_noflush_suspending);
2908 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
2909 unsigned integrity, unsigned per_io_data_size,
2910 unsigned min_pool_size)
2912 struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
2913 unsigned int pool_size = 0;
2914 unsigned int front_pad, io_front_pad;
2921 case DM_TYPE_BIO_BASED:
2922 case DM_TYPE_DAX_BIO_BASED:
2923 pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
2924 front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
2925 io_front_pad = roundup(per_io_data_size, __alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
2926 ret = bioset_init(&pools->io_bs, pool_size, io_front_pad, 0);
2929 if (integrity && bioset_integrity_create(&pools->io_bs, pool_size))
2932 case DM_TYPE_REQUEST_BASED:
2933 pool_size = max(dm_get_reserved_rq_based_ios(), min_pool_size);
2934 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
2935 /* per_io_data_size is used for blk-mq pdu at queue allocation */
2941 ret = bioset_init(&pools->bs, pool_size, front_pad, 0);
2945 if (integrity && bioset_integrity_create(&pools->bs, pool_size))
2951 dm_free_md_mempools(pools);
2956 void dm_free_md_mempools(struct dm_md_mempools *pools)
2961 bioset_exit(&pools->bs);
2962 bioset_exit(&pools->io_bs);
2974 static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
2977 struct mapped_device *md = bdev->bd_disk->private_data;
2978 struct dm_table *table;
2979 struct dm_target *ti;
2980 int ret = -ENOTTY, srcu_idx;
2982 table = dm_get_live_table(md, &srcu_idx);
2983 if (!table || !dm_table_get_size(table))
2986 /* We only support devices that have a single target */
2987 if (dm_table_get_num_targets(table) != 1)
2989 ti = dm_table_get_target(table, 0);
2992 if (!ti->type->iterate_devices)
2995 ret = ti->type->iterate_devices(ti, fn, data);
2997 dm_put_live_table(md, srcu_idx);
3002 * For register / unregister we need to manually call out to every path.
3004 static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev,
3005 sector_t start, sector_t len, void *data)
3007 struct dm_pr *pr = data;
3008 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
3010 if (!ops || !ops->pr_register)
3012 return ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
3015 static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
3026 ret = dm_call_pr(bdev, __dm_pr_register, &pr);
3027 if (ret && new_key) {
3028 /* unregister all paths if we failed to register any path */
3029 pr.old_key = new_key;
3032 pr.fail_early = false;
3033 dm_call_pr(bdev, __dm_pr_register, &pr);
3039 static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
3042 struct mapped_device *md = bdev->bd_disk->private_data;
3043 const struct pr_ops *ops;
3046 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3050 ops = bdev->bd_disk->fops->pr_ops;
3051 if (ops && ops->pr_reserve)
3052 r = ops->pr_reserve(bdev, key, type, flags);
3056 dm_unprepare_ioctl(md, srcu_idx);
3060 static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
3062 struct mapped_device *md = bdev->bd_disk->private_data;
3063 const struct pr_ops *ops;
3066 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3070 ops = bdev->bd_disk->fops->pr_ops;
3071 if (ops && ops->pr_release)
3072 r = ops->pr_release(bdev, key, type);
3076 dm_unprepare_ioctl(md, srcu_idx);
3080 static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
3081 enum pr_type type, bool abort)
3083 struct mapped_device *md = bdev->bd_disk->private_data;
3084 const struct pr_ops *ops;
3087 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3091 ops = bdev->bd_disk->fops->pr_ops;
3092 if (ops && ops->pr_preempt)
3093 r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
3097 dm_unprepare_ioctl(md, srcu_idx);
3101 static int dm_pr_clear(struct block_device *bdev, u64 key)
3103 struct mapped_device *md = bdev->bd_disk->private_data;
3104 const struct pr_ops *ops;
3107 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3111 ops = bdev->bd_disk->fops->pr_ops;
3112 if (ops && ops->pr_clear)
3113 r = ops->pr_clear(bdev, key);
3117 dm_unprepare_ioctl(md, srcu_idx);
3121 static const struct pr_ops dm_pr_ops = {
3122 .pr_register = dm_pr_register,
3123 .pr_reserve = dm_pr_reserve,
3124 .pr_release = dm_pr_release,
3125 .pr_preempt = dm_pr_preempt,
3126 .pr_clear = dm_pr_clear,
3129 static const struct block_device_operations dm_blk_dops = {
3130 .submit_bio = dm_submit_bio,
3131 .poll_bio = dm_poll_bio,
3132 .open = dm_blk_open,
3133 .release = dm_blk_close,
3134 .ioctl = dm_blk_ioctl,
3135 .getgeo = dm_blk_getgeo,
3136 .report_zones = dm_blk_report_zones,
3137 .pr_ops = &dm_pr_ops,
3138 .owner = THIS_MODULE
3141 static const struct block_device_operations dm_rq_blk_dops = {
3142 .open = dm_blk_open,
3143 .release = dm_blk_close,
3144 .ioctl = dm_blk_ioctl,
3145 .getgeo = dm_blk_getgeo,
3146 .pr_ops = &dm_pr_ops,
3147 .owner = THIS_MODULE
3150 static const struct dax_operations dm_dax_ops = {
3151 .direct_access = dm_dax_direct_access,
3152 .zero_page_range = dm_dax_zero_page_range,
3158 module_init(dm_init);
3159 module_exit(dm_exit);
3161 module_param(major, uint, 0);
3162 MODULE_PARM_DESC(major, "The major number of the device mapper");
3164 module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
3165 MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
3167 module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
3168 MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
3170 module_param(swap_bios, int, S_IRUGO | S_IWUSR);
3171 MODULE_PARM_DESC(swap_bios, "Maximum allowed inflight swap IOs");
3173 MODULE_DESCRIPTION(DM_NAME " driver");
3174 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3175 MODULE_LICENSE("GPL");