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>
28 #include <linux/part_stat.h>
30 #define DM_MSG_PREFIX "core"
33 * Cookies are numeric values sent with CHANGE and REMOVE
34 * uevents while resuming, removing or renaming the device.
36 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
37 #define DM_COOKIE_LENGTH 24
39 static const char *_name = DM_NAME;
41 static unsigned int major = 0;
42 static unsigned int _major = 0;
44 static DEFINE_IDR(_minor_idr);
46 static DEFINE_SPINLOCK(_minor_lock);
48 static void do_deferred_remove(struct work_struct *w);
50 static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
52 static struct workqueue_struct *deferred_remove_workqueue;
54 atomic_t dm_global_event_nr = ATOMIC_INIT(0);
55 DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq);
57 void dm_issue_global_event(void)
59 atomic_inc(&dm_global_event_nr);
60 wake_up(&dm_global_eventq);
64 * One of these is allocated (on-stack) per original bio.
71 unsigned sector_count;
75 * One of these is allocated per clone bio.
77 #define DM_TIO_MAGIC 7282014
82 unsigned target_bio_nr;
89 * One of these is allocated per original bio.
90 * It contains the first clone used for that original.
92 #define DM_IO_MAGIC 5191977
95 struct mapped_device *md;
99 unsigned long start_time;
100 spinlock_t endio_lock;
101 struct dm_stats_aux stats_aux;
102 /* last member of dm_target_io is 'struct bio' */
103 struct dm_target_io tio;
106 void *dm_per_bio_data(struct bio *bio, size_t data_size)
108 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
109 if (!tio->inside_dm_io)
110 return (char *)bio - offsetof(struct dm_target_io, clone) - data_size;
111 return (char *)bio - offsetof(struct dm_target_io, clone) - offsetof(struct dm_io, tio) - data_size;
113 EXPORT_SYMBOL_GPL(dm_per_bio_data);
115 struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size)
117 struct dm_io *io = (struct dm_io *)((char *)data + data_size);
118 if (io->magic == DM_IO_MAGIC)
119 return (struct bio *)((char *)io + offsetof(struct dm_io, tio) + offsetof(struct dm_target_io, clone));
120 BUG_ON(io->magic != DM_TIO_MAGIC);
121 return (struct bio *)((char *)io + offsetof(struct dm_target_io, clone));
123 EXPORT_SYMBOL_GPL(dm_bio_from_per_bio_data);
125 unsigned dm_bio_get_target_bio_nr(const struct bio *bio)
127 return container_of(bio, struct dm_target_io, clone)->target_bio_nr;
129 EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr);
131 #define MINOR_ALLOCED ((void *)-1)
134 * Bits for the md->flags field.
136 #define DMF_BLOCK_IO_FOR_SUSPEND 0
137 #define DMF_SUSPENDED 1
139 #define DMF_FREEING 3
140 #define DMF_DELETING 4
141 #define DMF_NOFLUSH_SUSPENDING 5
142 #define DMF_DEFERRED_REMOVE 6
143 #define DMF_SUSPENDED_INTERNALLY 7
145 #define DM_NUMA_NODE NUMA_NO_NODE
146 static int dm_numa_node = DM_NUMA_NODE;
149 * For mempools pre-allocation at the table loading time.
151 struct dm_md_mempools {
153 struct bio_set io_bs;
156 struct table_device {
157 struct list_head list;
159 struct dm_dev dm_dev;
163 * Bio-based DM's mempools' reserved IOs set by the user.
165 #define RESERVED_BIO_BASED_IOS 16
166 static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
168 static int __dm_get_module_param_int(int *module_param, int min, int max)
170 int param = READ_ONCE(*module_param);
171 int modified_param = 0;
172 bool modified = true;
175 modified_param = min;
176 else if (param > max)
177 modified_param = max;
182 (void)cmpxchg(module_param, param, modified_param);
183 param = modified_param;
189 unsigned __dm_get_module_param(unsigned *module_param,
190 unsigned def, unsigned max)
192 unsigned param = READ_ONCE(*module_param);
193 unsigned modified_param = 0;
196 modified_param = def;
197 else if (param > max)
198 modified_param = max;
200 if (modified_param) {
201 (void)cmpxchg(module_param, param, modified_param);
202 param = modified_param;
208 unsigned dm_get_reserved_bio_based_ios(void)
210 return __dm_get_module_param(&reserved_bio_based_ios,
211 RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS);
213 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
215 static unsigned dm_get_numa_node(void)
217 return __dm_get_module_param_int(&dm_numa_node,
218 DM_NUMA_NODE, num_online_nodes() - 1);
221 static int __init local_init(void)
225 r = dm_uevent_init();
229 deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
230 if (!deferred_remove_workqueue) {
232 goto out_uevent_exit;
236 r = register_blkdev(_major, _name);
238 goto out_free_workqueue;
246 destroy_workqueue(deferred_remove_workqueue);
253 static void local_exit(void)
255 flush_scheduled_work();
256 destroy_workqueue(deferred_remove_workqueue);
258 unregister_blkdev(_major, _name);
263 DMINFO("cleaned up");
266 static int (*_inits[])(void) __initdata = {
277 static void (*_exits[])(void) = {
288 static int __init dm_init(void)
290 const int count = ARRAY_SIZE(_inits);
294 for (i = 0; i < count; i++) {
309 static void __exit dm_exit(void)
311 int i = ARRAY_SIZE(_exits);
317 * Should be empty by this point.
319 idr_destroy(&_minor_idr);
323 * Block device functions
325 int dm_deleting_md(struct mapped_device *md)
327 return test_bit(DMF_DELETING, &md->flags);
330 static int dm_blk_open(struct block_device *bdev, fmode_t mode)
332 struct mapped_device *md;
334 spin_lock(&_minor_lock);
336 md = bdev->bd_disk->private_data;
340 if (test_bit(DMF_FREEING, &md->flags) ||
341 dm_deleting_md(md)) {
347 atomic_inc(&md->open_count);
349 spin_unlock(&_minor_lock);
351 return md ? 0 : -ENXIO;
354 static void dm_blk_close(struct gendisk *disk, fmode_t mode)
356 struct mapped_device *md;
358 spin_lock(&_minor_lock);
360 md = disk->private_data;
364 if (atomic_dec_and_test(&md->open_count) &&
365 (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
366 queue_work(deferred_remove_workqueue, &deferred_remove_work);
370 spin_unlock(&_minor_lock);
373 int dm_open_count(struct mapped_device *md)
375 return atomic_read(&md->open_count);
379 * Guarantees nothing is using the device before it's deleted.
381 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
385 spin_lock(&_minor_lock);
387 if (dm_open_count(md)) {
390 set_bit(DMF_DEFERRED_REMOVE, &md->flags);
391 } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
394 set_bit(DMF_DELETING, &md->flags);
396 spin_unlock(&_minor_lock);
401 int dm_cancel_deferred_remove(struct mapped_device *md)
405 spin_lock(&_minor_lock);
407 if (test_bit(DMF_DELETING, &md->flags))
410 clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
412 spin_unlock(&_minor_lock);
417 static void do_deferred_remove(struct work_struct *w)
419 dm_deferred_remove();
422 sector_t dm_get_size(struct mapped_device *md)
424 return get_capacity(md->disk);
427 struct request_queue *dm_get_md_queue(struct mapped_device *md)
432 struct dm_stats *dm_get_stats(struct mapped_device *md)
437 static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
439 struct mapped_device *md = bdev->bd_disk->private_data;
441 return dm_get_geometry(md, geo);
444 #ifdef CONFIG_BLK_DEV_ZONED
445 int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx, void *data)
447 struct dm_report_zones_args *args = data;
448 sector_t sector_diff = args->tgt->begin - args->start;
451 * Ignore zones beyond the target range.
453 if (zone->start >= args->start + args->tgt->len)
457 * Remap the start sector and write pointer position of the zone
458 * to match its position in the target range.
460 zone->start += sector_diff;
461 if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
462 if (zone->cond == BLK_ZONE_COND_FULL)
463 zone->wp = zone->start + zone->len;
464 else if (zone->cond == BLK_ZONE_COND_EMPTY)
465 zone->wp = zone->start;
467 zone->wp += sector_diff;
470 args->next_sector = zone->start + zone->len;
471 return args->orig_cb(zone, args->zone_idx++, args->orig_data);
473 EXPORT_SYMBOL_GPL(dm_report_zones_cb);
475 static int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
476 unsigned int nr_zones, report_zones_cb cb, void *data)
478 struct mapped_device *md = disk->private_data;
479 struct dm_table *map;
481 struct dm_report_zones_args args = {
482 .next_sector = sector,
487 if (dm_suspended_md(md))
490 map = dm_get_live_table(md, &srcu_idx);
495 struct dm_target *tgt;
497 tgt = dm_table_find_target(map, args.next_sector);
498 if (WARN_ON_ONCE(!tgt->type->report_zones)) {
504 ret = tgt->type->report_zones(tgt, &args, nr_zones);
507 } while (args.zone_idx < nr_zones &&
508 args.next_sector < get_capacity(disk));
512 dm_put_live_table(md, srcu_idx);
516 #define dm_blk_report_zones NULL
517 #endif /* CONFIG_BLK_DEV_ZONED */
519 static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx,
520 struct block_device **bdev)
521 __acquires(md->io_barrier)
523 struct dm_target *tgt;
524 struct dm_table *map;
529 map = dm_get_live_table(md, srcu_idx);
530 if (!map || !dm_table_get_size(map))
533 /* We only support devices that have a single target */
534 if (dm_table_get_num_targets(map) != 1)
537 tgt = dm_table_get_target(map, 0);
538 if (!tgt->type->prepare_ioctl)
541 if (dm_suspended_md(md))
544 r = tgt->type->prepare_ioctl(tgt, bdev);
545 if (r == -ENOTCONN && !fatal_signal_pending(current)) {
546 dm_put_live_table(md, *srcu_idx);
554 static void dm_unprepare_ioctl(struct mapped_device *md, int srcu_idx)
555 __releases(md->io_barrier)
557 dm_put_live_table(md, srcu_idx);
560 static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
561 unsigned int cmd, unsigned long arg)
563 struct mapped_device *md = bdev->bd_disk->private_data;
566 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
572 * Target determined this ioctl is being issued against a
573 * subset of the parent bdev; require extra privileges.
575 if (!capable(CAP_SYS_RAWIO)) {
577 "%s: sending ioctl %x to DM device without required privilege.",
584 r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
586 dm_unprepare_ioctl(md, srcu_idx);
590 static void start_io_acct(struct dm_io *io);
592 static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio)
595 struct dm_target_io *tio;
598 clone = bio_alloc_bioset(GFP_NOIO, 0, &md->io_bs);
602 tio = container_of(clone, struct dm_target_io, clone);
603 tio->inside_dm_io = true;
606 io = container_of(tio, struct dm_io, tio);
607 io->magic = DM_IO_MAGIC;
609 atomic_set(&io->io_count, 1);
612 spin_lock_init(&io->endio_lock);
619 static void free_io(struct mapped_device *md, struct dm_io *io)
621 bio_put(&io->tio.clone);
624 static struct dm_target_io *alloc_tio(struct clone_info *ci, struct dm_target *ti,
625 unsigned target_bio_nr, gfp_t gfp_mask)
627 struct dm_target_io *tio;
629 if (!ci->io->tio.io) {
630 /* the dm_target_io embedded in ci->io is available */
633 struct bio *clone = bio_alloc_bioset(gfp_mask, 0, &ci->io->md->bs);
637 tio = container_of(clone, struct dm_target_io, clone);
638 tio->inside_dm_io = false;
641 tio->magic = DM_TIO_MAGIC;
644 tio->target_bio_nr = target_bio_nr;
649 static void free_tio(struct dm_target_io *tio)
651 if (tio->inside_dm_io)
653 bio_put(&tio->clone);
656 static bool md_in_flight_bios(struct mapped_device *md)
659 struct hd_struct *part = &dm_disk(md)->part0;
662 for_each_possible_cpu(cpu) {
663 sum += part_stat_local_read_cpu(part, in_flight[0], cpu);
664 sum += part_stat_local_read_cpu(part, in_flight[1], cpu);
670 static bool md_in_flight(struct mapped_device *md)
672 if (queue_is_mq(md->queue))
673 return blk_mq_queue_inflight(md->queue);
675 return md_in_flight_bios(md);
678 static void start_io_acct(struct dm_io *io)
680 struct mapped_device *md = io->md;
681 struct bio *bio = io->orig_bio;
683 io->start_time = jiffies;
685 generic_start_io_acct(md->queue, bio_op(bio), bio_sectors(bio),
686 &dm_disk(md)->part0);
688 if (unlikely(dm_stats_used(&md->stats)))
689 dm_stats_account_io(&md->stats, bio_data_dir(bio),
690 bio->bi_iter.bi_sector, bio_sectors(bio),
691 false, 0, &io->stats_aux);
694 static void end_io_acct(struct dm_io *io)
696 struct mapped_device *md = io->md;
697 struct bio *bio = io->orig_bio;
698 unsigned long duration = jiffies - io->start_time;
700 generic_end_io_acct(md->queue, bio_op(bio), &dm_disk(md)->part0,
703 if (unlikely(dm_stats_used(&md->stats)))
704 dm_stats_account_io(&md->stats, bio_data_dir(bio),
705 bio->bi_iter.bi_sector, bio_sectors(bio),
706 true, duration, &io->stats_aux);
708 /* nudge anyone waiting on suspend queue */
709 if (unlikely(wq_has_sleeper(&md->wait)))
714 * Add the bio to the list of deferred io.
716 static void queue_io(struct mapped_device *md, struct bio *bio)
720 spin_lock_irqsave(&md->deferred_lock, flags);
721 bio_list_add(&md->deferred, bio);
722 spin_unlock_irqrestore(&md->deferred_lock, flags);
723 queue_work(md->wq, &md->work);
727 * Everyone (including functions in this file), should use this
728 * function to access the md->map field, and make sure they call
729 * dm_put_live_table() when finished.
731 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
733 *srcu_idx = srcu_read_lock(&md->io_barrier);
735 return srcu_dereference(md->map, &md->io_barrier);
738 void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
740 srcu_read_unlock(&md->io_barrier, srcu_idx);
743 void dm_sync_table(struct mapped_device *md)
745 synchronize_srcu(&md->io_barrier);
746 synchronize_rcu_expedited();
750 * A fast alternative to dm_get_live_table/dm_put_live_table.
751 * The caller must not block between these two functions.
753 static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
756 return rcu_dereference(md->map);
759 static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
764 static char *_dm_claim_ptr = "I belong to device-mapper";
767 * Open a table device so we can use it as a map destination.
769 static int open_table_device(struct table_device *td, dev_t dev,
770 struct mapped_device *md)
772 struct block_device *bdev;
776 BUG_ON(td->dm_dev.bdev);
778 bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr);
780 return PTR_ERR(bdev);
782 r = bd_link_disk_holder(bdev, dm_disk(md));
784 blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
788 td->dm_dev.bdev = bdev;
789 td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
794 * Close a table device that we've been using.
796 static void close_table_device(struct table_device *td, struct mapped_device *md)
798 if (!td->dm_dev.bdev)
801 bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
802 blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
803 put_dax(td->dm_dev.dax_dev);
804 td->dm_dev.bdev = NULL;
805 td->dm_dev.dax_dev = NULL;
808 static struct table_device *find_table_device(struct list_head *l, dev_t dev,
811 struct table_device *td;
813 list_for_each_entry(td, l, list)
814 if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
820 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
821 struct dm_dev **result)
824 struct table_device *td;
826 mutex_lock(&md->table_devices_lock);
827 td = find_table_device(&md->table_devices, dev, mode);
829 td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
831 mutex_unlock(&md->table_devices_lock);
835 td->dm_dev.mode = mode;
836 td->dm_dev.bdev = NULL;
838 if ((r = open_table_device(td, dev, md))) {
839 mutex_unlock(&md->table_devices_lock);
844 format_dev_t(td->dm_dev.name, dev);
846 refcount_set(&td->count, 1);
847 list_add(&td->list, &md->table_devices);
849 refcount_inc(&td->count);
851 mutex_unlock(&md->table_devices_lock);
853 *result = &td->dm_dev;
856 EXPORT_SYMBOL_GPL(dm_get_table_device);
858 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
860 struct table_device *td = container_of(d, struct table_device, dm_dev);
862 mutex_lock(&md->table_devices_lock);
863 if (refcount_dec_and_test(&td->count)) {
864 close_table_device(td, md);
868 mutex_unlock(&md->table_devices_lock);
870 EXPORT_SYMBOL(dm_put_table_device);
872 static void free_table_devices(struct list_head *devices)
874 struct list_head *tmp, *next;
876 list_for_each_safe(tmp, next, devices) {
877 struct table_device *td = list_entry(tmp, struct table_device, list);
879 DMWARN("dm_destroy: %s still exists with %d references",
880 td->dm_dev.name, refcount_read(&td->count));
886 * Get the geometry associated with a dm device
888 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
896 * Set the geometry of a device.
898 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
900 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
902 if (geo->start > sz) {
903 DMWARN("Start sector is beyond the geometry limits.");
912 static int __noflush_suspending(struct mapped_device *md)
914 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
918 * Decrements the number of outstanding ios that a bio has been
919 * cloned into, completing the original io if necc.
921 static void dec_pending(struct dm_io *io, blk_status_t error)
924 blk_status_t io_error;
926 struct mapped_device *md = io->md;
928 /* Push-back supersedes any I/O errors */
929 if (unlikely(error)) {
930 spin_lock_irqsave(&io->endio_lock, flags);
931 if (!(io->status == BLK_STS_DM_REQUEUE && __noflush_suspending(md)))
933 spin_unlock_irqrestore(&io->endio_lock, flags);
936 if (atomic_dec_and_test(&io->io_count)) {
937 if (io->status == BLK_STS_DM_REQUEUE) {
939 * Target requested pushing back the I/O.
941 spin_lock_irqsave(&md->deferred_lock, flags);
942 if (__noflush_suspending(md))
943 /* NOTE early return due to BLK_STS_DM_REQUEUE below */
944 bio_list_add_head(&md->deferred, io->orig_bio);
946 /* noflush suspend was interrupted. */
947 io->status = BLK_STS_IOERR;
948 spin_unlock_irqrestore(&md->deferred_lock, flags);
951 io_error = io->status;
956 if (io_error == BLK_STS_DM_REQUEUE)
959 if ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size) {
961 * Preflush done for flush with data, reissue
962 * without REQ_PREFLUSH.
964 bio->bi_opf &= ~REQ_PREFLUSH;
967 /* done with normal IO or empty flush */
969 bio->bi_status = io_error;
975 void disable_discard(struct mapped_device *md)
977 struct queue_limits *limits = dm_get_queue_limits(md);
979 /* device doesn't really support DISCARD, disable it */
980 limits->max_discard_sectors = 0;
981 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, md->queue);
984 void disable_write_same(struct mapped_device *md)
986 struct queue_limits *limits = dm_get_queue_limits(md);
988 /* device doesn't really support WRITE SAME, disable it */
989 limits->max_write_same_sectors = 0;
992 void disable_write_zeroes(struct mapped_device *md)
994 struct queue_limits *limits = dm_get_queue_limits(md);
996 /* device doesn't really support WRITE ZEROES, disable it */
997 limits->max_write_zeroes_sectors = 0;
1000 static void clone_endio(struct bio *bio)
1002 blk_status_t error = bio->bi_status;
1003 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1004 struct dm_io *io = tio->io;
1005 struct mapped_device *md = tio->io->md;
1006 dm_endio_fn endio = tio->ti->type->end_io;
1008 if (unlikely(error == BLK_STS_TARGET) && md->type != DM_TYPE_NVME_BIO_BASED) {
1009 if (bio_op(bio) == REQ_OP_DISCARD &&
1010 !bio->bi_disk->queue->limits.max_discard_sectors)
1011 disable_discard(md);
1012 else if (bio_op(bio) == REQ_OP_WRITE_SAME &&
1013 !bio->bi_disk->queue->limits.max_write_same_sectors)
1014 disable_write_same(md);
1015 else if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
1016 !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
1017 disable_write_zeroes(md);
1021 int r = endio(tio->ti, bio, &error);
1023 case DM_ENDIO_REQUEUE:
1024 error = BLK_STS_DM_REQUEUE;
1028 case DM_ENDIO_INCOMPLETE:
1029 /* The target will handle the io */
1032 DMWARN("unimplemented target endio return value: %d", r);
1038 dec_pending(io, error);
1042 * Return maximum size of I/O possible at the supplied sector up to the current
1045 static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
1047 sector_t target_offset = dm_target_offset(ti, sector);
1049 return ti->len - target_offset;
1052 static sector_t max_io_len(sector_t sector, struct dm_target *ti)
1054 sector_t len = max_io_len_target_boundary(sector, ti);
1055 sector_t offset, max_len;
1058 * Does the target need to split even further?
1060 if (ti->max_io_len) {
1061 offset = dm_target_offset(ti, sector);
1062 if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
1063 max_len = sector_div(offset, ti->max_io_len);
1065 max_len = offset & (ti->max_io_len - 1);
1066 max_len = ti->max_io_len - max_len;
1075 int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
1077 if (len > UINT_MAX) {
1078 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
1079 (unsigned long long)len, UINT_MAX);
1080 ti->error = "Maximum size of target IO is too large";
1084 ti->max_io_len = (uint32_t) len;
1088 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
1090 static struct dm_target *dm_dax_get_live_target(struct mapped_device *md,
1091 sector_t sector, int *srcu_idx)
1092 __acquires(md->io_barrier)
1094 struct dm_table *map;
1095 struct dm_target *ti;
1097 map = dm_get_live_table(md, srcu_idx);
1101 ti = dm_table_find_target(map, sector);
1108 static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
1109 long nr_pages, void **kaddr, pfn_t *pfn)
1111 struct mapped_device *md = dax_get_private(dax_dev);
1112 sector_t sector = pgoff * PAGE_SECTORS;
1113 struct dm_target *ti;
1114 long len, ret = -EIO;
1117 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1121 if (!ti->type->direct_access)
1123 len = max_io_len(sector, ti) / PAGE_SECTORS;
1126 nr_pages = min(len, nr_pages);
1127 ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn);
1130 dm_put_live_table(md, srcu_idx);
1135 static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
1136 int blocksize, sector_t start, sector_t len)
1138 struct mapped_device *md = dax_get_private(dax_dev);
1139 struct dm_table *map;
1143 map = dm_get_live_table(md, &srcu_idx);
1147 ret = dm_table_supports_dax(map, device_supports_dax, &blocksize);
1149 dm_put_live_table(md, srcu_idx);
1154 static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
1155 void *addr, size_t bytes, struct iov_iter *i)
1157 struct mapped_device *md = dax_get_private(dax_dev);
1158 sector_t sector = pgoff * PAGE_SECTORS;
1159 struct dm_target *ti;
1163 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1167 if (!ti->type->dax_copy_from_iter) {
1168 ret = copy_from_iter(addr, bytes, i);
1171 ret = ti->type->dax_copy_from_iter(ti, pgoff, addr, bytes, i);
1173 dm_put_live_table(md, srcu_idx);
1178 static size_t dm_dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
1179 void *addr, size_t bytes, struct iov_iter *i)
1181 struct mapped_device *md = dax_get_private(dax_dev);
1182 sector_t sector = pgoff * PAGE_SECTORS;
1183 struct dm_target *ti;
1187 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1191 if (!ti->type->dax_copy_to_iter) {
1192 ret = copy_to_iter(addr, bytes, i);
1195 ret = ti->type->dax_copy_to_iter(ti, pgoff, addr, bytes, i);
1197 dm_put_live_table(md, srcu_idx);
1203 * A target may call dm_accept_partial_bio only from the map routine. It is
1204 * allowed for all bio types except REQ_PREFLUSH, REQ_OP_ZONE_RESET,
1205 * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH.
1207 * dm_accept_partial_bio informs the dm that the target only wants to process
1208 * additional n_sectors sectors of the bio and the rest of the data should be
1209 * sent in a next bio.
1211 * A diagram that explains the arithmetics:
1212 * +--------------------+---------------+-------+
1214 * +--------------------+---------------+-------+
1216 * <-------------- *tio->len_ptr --------------->
1217 * <------- bi_size ------->
1220 * Region 1 was already iterated over with bio_advance or similar function.
1221 * (it may be empty if the target doesn't use bio_advance)
1222 * Region 2 is the remaining bio size that the target wants to process.
1223 * (it may be empty if region 1 is non-empty, although there is no reason
1225 * The target requires that region 3 is to be sent in the next bio.
1227 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1228 * the partially processed part (the sum of regions 1+2) must be the same for all
1229 * copies of the bio.
1231 void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
1233 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1234 unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
1235 BUG_ON(bio->bi_opf & REQ_PREFLUSH);
1236 BUG_ON(bi_size > *tio->len_ptr);
1237 BUG_ON(n_sectors > bi_size);
1238 *tio->len_ptr -= bi_size - n_sectors;
1239 bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
1241 EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
1243 static blk_qc_t __map_bio(struct dm_target_io *tio)
1247 struct bio *clone = &tio->clone;
1248 struct dm_io *io = tio->io;
1249 struct mapped_device *md = io->md;
1250 struct dm_target *ti = tio->ti;
1251 blk_qc_t ret = BLK_QC_T_NONE;
1253 clone->bi_end_io = clone_endio;
1256 * Map the clone. If r == 0 we don't need to do
1257 * anything, the target has assumed ownership of
1260 atomic_inc(&io->io_count);
1261 sector = clone->bi_iter.bi_sector;
1263 r = ti->type->map(ti, clone);
1265 case DM_MAPIO_SUBMITTED:
1267 case DM_MAPIO_REMAPPED:
1268 /* the bio has been remapped so dispatch it */
1269 trace_block_bio_remap(clone->bi_disk->queue, clone,
1270 bio_dev(io->orig_bio), sector);
1271 if (md->type == DM_TYPE_NVME_BIO_BASED)
1272 ret = direct_make_request(clone);
1274 ret = generic_make_request(clone);
1278 dec_pending(io, BLK_STS_IOERR);
1280 case DM_MAPIO_REQUEUE:
1282 dec_pending(io, BLK_STS_DM_REQUEUE);
1285 DMWARN("unimplemented target map return value: %d", r);
1292 static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
1294 bio->bi_iter.bi_sector = sector;
1295 bio->bi_iter.bi_size = to_bytes(len);
1299 * Creates a bio that consists of range of complete bvecs.
1301 static int clone_bio(struct dm_target_io *tio, struct bio *bio,
1302 sector_t sector, unsigned len)
1304 struct bio *clone = &tio->clone;
1306 __bio_clone_fast(clone, bio);
1308 if (bio_integrity(bio)) {
1311 if (unlikely(!dm_target_has_integrity(tio->ti->type) &&
1312 !dm_target_passes_integrity(tio->ti->type))) {
1313 DMWARN("%s: the target %s doesn't support integrity data.",
1314 dm_device_name(tio->io->md),
1315 tio->ti->type->name);
1319 r = bio_integrity_clone(clone, bio, GFP_NOIO);
1324 bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
1325 clone->bi_iter.bi_size = to_bytes(len);
1327 if (bio_integrity(bio))
1328 bio_integrity_trim(clone);
1333 static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci,
1334 struct dm_target *ti, unsigned num_bios)
1336 struct dm_target_io *tio;
1342 if (num_bios == 1) {
1343 tio = alloc_tio(ci, ti, 0, GFP_NOIO);
1344 bio_list_add(blist, &tio->clone);
1348 for (try = 0; try < 2; try++) {
1353 mutex_lock(&ci->io->md->table_devices_lock);
1354 for (bio_nr = 0; bio_nr < num_bios; bio_nr++) {
1355 tio = alloc_tio(ci, ti, bio_nr, try ? GFP_NOIO : GFP_NOWAIT);
1359 bio_list_add(blist, &tio->clone);
1362 mutex_unlock(&ci->io->md->table_devices_lock);
1363 if (bio_nr == num_bios)
1366 while ((bio = bio_list_pop(blist))) {
1367 tio = container_of(bio, struct dm_target_io, clone);
1373 static blk_qc_t __clone_and_map_simple_bio(struct clone_info *ci,
1374 struct dm_target_io *tio, unsigned *len)
1376 struct bio *clone = &tio->clone;
1380 __bio_clone_fast(clone, ci->bio);
1382 bio_setup_sector(clone, ci->sector, *len);
1384 return __map_bio(tio);
1387 static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
1388 unsigned num_bios, unsigned *len)
1390 struct bio_list blist = BIO_EMPTY_LIST;
1392 struct dm_target_io *tio;
1394 alloc_multiple_bios(&blist, ci, ti, num_bios);
1396 while ((bio = bio_list_pop(&blist))) {
1397 tio = container_of(bio, struct dm_target_io, clone);
1398 (void) __clone_and_map_simple_bio(ci, tio, len);
1402 static int __send_empty_flush(struct clone_info *ci)
1404 unsigned target_nr = 0;
1405 struct dm_target *ti;
1408 * Empty flush uses a statically initialized bio, as the base for
1409 * cloning. However, blkg association requires that a bdev is
1410 * associated with a gendisk, which doesn't happen until the bdev is
1411 * opened. So, blkg association is done at issue time of the flush
1412 * rather than when the device is created in alloc_dev().
1414 bio_set_dev(ci->bio, ci->io->md->bdev);
1416 BUG_ON(bio_has_data(ci->bio));
1417 while ((ti = dm_table_get_target(ci->map, target_nr++)))
1418 __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
1420 bio_disassociate_blkg(ci->bio);
1425 static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
1426 sector_t sector, unsigned *len)
1428 struct bio *bio = ci->bio;
1429 struct dm_target_io *tio;
1432 tio = alloc_tio(ci, ti, 0, GFP_NOIO);
1434 r = clone_bio(tio, bio, sector, *len);
1439 (void) __map_bio(tio);
1444 typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
1446 static unsigned get_num_discard_bios(struct dm_target *ti)
1448 return ti->num_discard_bios;
1451 static unsigned get_num_secure_erase_bios(struct dm_target *ti)
1453 return ti->num_secure_erase_bios;
1456 static unsigned get_num_write_same_bios(struct dm_target *ti)
1458 return ti->num_write_same_bios;
1461 static unsigned get_num_write_zeroes_bios(struct dm_target *ti)
1463 return ti->num_write_zeroes_bios;
1466 static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti,
1472 * Even though the device advertised support for this type of
1473 * request, that does not mean every target supports it, and
1474 * reconfiguration might also have changed that since the
1475 * check was performed.
1480 len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
1482 __send_duplicate_bios(ci, ti, num_bios, &len);
1485 ci->sector_count -= len;
1490 static int __send_discard(struct clone_info *ci, struct dm_target *ti)
1492 return __send_changing_extent_only(ci, ti, get_num_discard_bios(ti));
1495 static int __send_secure_erase(struct clone_info *ci, struct dm_target *ti)
1497 return __send_changing_extent_only(ci, ti, get_num_secure_erase_bios(ti));
1500 static int __send_write_same(struct clone_info *ci, struct dm_target *ti)
1502 return __send_changing_extent_only(ci, ti, get_num_write_same_bios(ti));
1505 static int __send_write_zeroes(struct clone_info *ci, struct dm_target *ti)
1507 return __send_changing_extent_only(ci, ti, get_num_write_zeroes_bios(ti));
1510 static bool is_abnormal_io(struct bio *bio)
1514 switch (bio_op(bio)) {
1515 case REQ_OP_DISCARD:
1516 case REQ_OP_SECURE_ERASE:
1517 case REQ_OP_WRITE_SAME:
1518 case REQ_OP_WRITE_ZEROES:
1526 static bool __process_abnormal_io(struct clone_info *ci, struct dm_target *ti,
1529 struct bio *bio = ci->bio;
1531 if (bio_op(bio) == REQ_OP_DISCARD)
1532 *result = __send_discard(ci, ti);
1533 else if (bio_op(bio) == REQ_OP_SECURE_ERASE)
1534 *result = __send_secure_erase(ci, ti);
1535 else if (bio_op(bio) == REQ_OP_WRITE_SAME)
1536 *result = __send_write_same(ci, ti);
1537 else if (bio_op(bio) == REQ_OP_WRITE_ZEROES)
1538 *result = __send_write_zeroes(ci, ti);
1546 * Select the correct strategy for processing a non-flush bio.
1548 static int __split_and_process_non_flush(struct clone_info *ci)
1550 struct dm_target *ti;
1554 ti = dm_table_find_target(ci->map, ci->sector);
1558 if (__process_abnormal_io(ci, ti, &r))
1561 len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count);
1563 r = __clone_and_map_data_bio(ci, ti, ci->sector, &len);
1568 ci->sector_count -= len;
1573 static void init_clone_info(struct clone_info *ci, struct mapped_device *md,
1574 struct dm_table *map, struct bio *bio)
1577 ci->io = alloc_io(md, bio);
1578 ci->sector = bio->bi_iter.bi_sector;
1581 #define __dm_part_stat_sub(part, field, subnd) \
1582 (part_stat_get(part, field) -= (subnd))
1585 * Entry point to split a bio into clones and submit them to the targets.
1587 static blk_qc_t __split_and_process_bio(struct mapped_device *md,
1588 struct dm_table *map, struct bio *bio)
1590 struct clone_info ci;
1591 blk_qc_t ret = BLK_QC_T_NONE;
1594 init_clone_info(&ci, md, map, bio);
1596 if (bio->bi_opf & REQ_PREFLUSH) {
1597 struct bio flush_bio;
1600 * Use an on-stack bio for this, it's safe since we don't
1601 * need to reference it after submit. It's just used as
1602 * the basis for the clone(s).
1604 bio_init(&flush_bio, NULL, 0);
1605 flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
1606 ci.bio = &flush_bio;
1607 ci.sector_count = 0;
1608 error = __send_empty_flush(&ci);
1609 /* dec_pending submits any data associated with flush */
1610 } else if (op_is_zone_mgmt(bio_op(bio))) {
1612 ci.sector_count = 0;
1613 error = __split_and_process_non_flush(&ci);
1616 ci.sector_count = bio_sectors(bio);
1617 while (ci.sector_count && !error) {
1618 error = __split_and_process_non_flush(&ci);
1619 if (current->bio_list && ci.sector_count && !error) {
1621 * Remainder must be passed to generic_make_request()
1622 * so that it gets handled *after* bios already submitted
1623 * have been completely processed.
1624 * We take a clone of the original to store in
1625 * ci.io->orig_bio to be used by end_io_acct() and
1626 * for dec_pending to use for completion handling.
1628 struct bio *b = bio_split(bio, bio_sectors(bio) - ci.sector_count,
1629 GFP_NOIO, &md->queue->bio_split);
1630 ci.io->orig_bio = b;
1633 * Adjust IO stats for each split, otherwise upon queue
1634 * reentry there will be redundant IO accounting.
1635 * NOTE: this is a stop-gap fix, a proper fix involves
1636 * significant refactoring of DM core's bio splitting
1637 * (by eliminating DM's splitting and just using bio_split)
1640 __dm_part_stat_sub(&dm_disk(md)->part0,
1641 sectors[op_stat_group(bio_op(bio))], ci.sector_count);
1645 trace_block_split(md->queue, b, bio->bi_iter.bi_sector);
1646 ret = generic_make_request(bio);
1652 /* drop the extra reference count */
1653 dec_pending(ci.io, errno_to_blk_status(error));
1658 * Optimized variant of __split_and_process_bio that leverages the
1659 * fact that targets that use it do _not_ have a need to split bios.
1661 static blk_qc_t __process_bio(struct mapped_device *md, struct dm_table *map,
1662 struct bio *bio, struct dm_target *ti)
1664 struct clone_info ci;
1665 blk_qc_t ret = BLK_QC_T_NONE;
1668 init_clone_info(&ci, md, map, bio);
1670 if (bio->bi_opf & REQ_PREFLUSH) {
1671 struct bio flush_bio;
1674 * Use an on-stack bio for this, it's safe since we don't
1675 * need to reference it after submit. It's just used as
1676 * the basis for the clone(s).
1678 bio_init(&flush_bio, NULL, 0);
1679 flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
1680 ci.bio = &flush_bio;
1681 ci.sector_count = 0;
1682 error = __send_empty_flush(&ci);
1683 /* dec_pending submits any data associated with flush */
1685 struct dm_target_io *tio;
1688 ci.sector_count = bio_sectors(bio);
1689 if (__process_abnormal_io(&ci, ti, &error))
1692 tio = alloc_tio(&ci, ti, 0, GFP_NOIO);
1693 ret = __clone_and_map_simple_bio(&ci, tio, NULL);
1696 /* drop the extra reference count */
1697 dec_pending(ci.io, errno_to_blk_status(error));
1701 static void dm_queue_split(struct mapped_device *md, struct dm_target *ti, struct bio **bio)
1703 unsigned len, sector_count;
1705 sector_count = bio_sectors(*bio);
1706 len = min_t(sector_t, max_io_len((*bio)->bi_iter.bi_sector, ti), sector_count);
1708 if (sector_count > len) {
1709 struct bio *split = bio_split(*bio, len, GFP_NOIO, &md->queue->bio_split);
1711 bio_chain(split, *bio);
1712 trace_block_split(md->queue, split, (*bio)->bi_iter.bi_sector);
1713 generic_make_request(*bio);
1718 static blk_qc_t dm_process_bio(struct mapped_device *md,
1719 struct dm_table *map, struct bio *bio)
1721 blk_qc_t ret = BLK_QC_T_NONE;
1722 struct dm_target *ti = md->immutable_target;
1724 if (unlikely(!map)) {
1730 ti = dm_table_find_target(map, bio->bi_iter.bi_sector);
1731 if (unlikely(!ti)) {
1738 * If in ->make_request_fn we need to use blk_queue_split(), otherwise
1739 * queue_limits for abnormal requests (e.g. discard, writesame, etc)
1742 if (current->bio_list) {
1743 if (is_abnormal_io(bio))
1744 blk_queue_split(md->queue, &bio);
1746 dm_queue_split(md, ti, &bio);
1749 if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
1750 return __process_bio(md, map, bio, ti);
1752 return __split_and_process_bio(md, map, bio);
1755 static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
1757 struct mapped_device *md = q->queuedata;
1758 blk_qc_t ret = BLK_QC_T_NONE;
1760 struct dm_table *map;
1762 map = dm_get_live_table(md, &srcu_idx);
1764 /* if we're suspended, we have to queue this io for later */
1765 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
1766 dm_put_live_table(md, srcu_idx);
1768 if (!(bio->bi_opf & REQ_RAHEAD))
1775 ret = dm_process_bio(md, map, bio);
1777 dm_put_live_table(md, srcu_idx);
1781 static int dm_any_congested(void *congested_data, int bdi_bits)
1784 struct mapped_device *md = congested_data;
1785 struct dm_table *map;
1787 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
1788 if (dm_request_based(md)) {
1790 * With request-based DM we only need to check the
1791 * top-level queue for congestion.
1793 struct backing_dev_info *bdi = md->queue->backing_dev_info;
1794 r = bdi->wb.congested->state & bdi_bits;
1796 map = dm_get_live_table_fast(md);
1798 r = dm_table_any_congested(map, bdi_bits);
1799 dm_put_live_table_fast(md);
1806 /*-----------------------------------------------------------------
1807 * An IDR is used to keep track of allocated minor numbers.
1808 *---------------------------------------------------------------*/
1809 static void free_minor(int minor)
1811 spin_lock(&_minor_lock);
1812 idr_remove(&_minor_idr, minor);
1813 spin_unlock(&_minor_lock);
1817 * See if the device with a specific minor # is free.
1819 static int specific_minor(int minor)
1823 if (minor >= (1 << MINORBITS))
1826 idr_preload(GFP_KERNEL);
1827 spin_lock(&_minor_lock);
1829 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
1831 spin_unlock(&_minor_lock);
1834 return r == -ENOSPC ? -EBUSY : r;
1838 static int next_free_minor(int *minor)
1842 idr_preload(GFP_KERNEL);
1843 spin_lock(&_minor_lock);
1845 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
1847 spin_unlock(&_minor_lock);
1855 static const struct block_device_operations dm_blk_dops;
1856 static const struct dax_operations dm_dax_ops;
1858 static void dm_wq_work(struct work_struct *work);
1860 static void cleanup_mapped_device(struct mapped_device *md)
1863 destroy_workqueue(md->wq);
1864 bioset_exit(&md->bs);
1865 bioset_exit(&md->io_bs);
1868 kill_dax(md->dax_dev);
1869 put_dax(md->dax_dev);
1874 spin_lock(&_minor_lock);
1875 md->disk->private_data = NULL;
1876 spin_unlock(&_minor_lock);
1877 del_gendisk(md->disk);
1882 blk_cleanup_queue(md->queue);
1884 cleanup_srcu_struct(&md->io_barrier);
1891 mutex_destroy(&md->suspend_lock);
1892 mutex_destroy(&md->type_lock);
1893 mutex_destroy(&md->table_devices_lock);
1895 dm_mq_cleanup_mapped_device(md);
1899 * Allocate and initialise a blank device with a given minor.
1901 static struct mapped_device *alloc_dev(int minor)
1903 int r, numa_node_id = dm_get_numa_node();
1904 struct mapped_device *md;
1907 md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
1909 DMWARN("unable to allocate device, out of memory.");
1913 if (!try_module_get(THIS_MODULE))
1914 goto bad_module_get;
1916 /* get a minor number for the dev */
1917 if (minor == DM_ANY_MINOR)
1918 r = next_free_minor(&minor);
1920 r = specific_minor(minor);
1924 r = init_srcu_struct(&md->io_barrier);
1926 goto bad_io_barrier;
1928 md->numa_node_id = numa_node_id;
1929 md->init_tio_pdu = false;
1930 md->type = DM_TYPE_NONE;
1931 mutex_init(&md->suspend_lock);
1932 mutex_init(&md->type_lock);
1933 mutex_init(&md->table_devices_lock);
1934 spin_lock_init(&md->deferred_lock);
1935 atomic_set(&md->holders, 1);
1936 atomic_set(&md->open_count, 0);
1937 atomic_set(&md->event_nr, 0);
1938 atomic_set(&md->uevent_seq, 0);
1939 INIT_LIST_HEAD(&md->uevent_list);
1940 INIT_LIST_HEAD(&md->table_devices);
1941 spin_lock_init(&md->uevent_lock);
1944 * default to bio-based required ->make_request_fn until DM
1945 * table is loaded and md->type established. If request-based
1946 * table is loaded: blk-mq will override accordingly.
1948 md->queue = blk_alloc_queue(dm_make_request, numa_node_id);
1951 md->queue->queuedata = md;
1953 md->disk = alloc_disk_node(1, md->numa_node_id);
1957 init_waitqueue_head(&md->wait);
1958 INIT_WORK(&md->work, dm_wq_work);
1959 init_waitqueue_head(&md->eventq);
1960 init_completion(&md->kobj_holder.completion);
1962 md->disk->major = _major;
1963 md->disk->first_minor = minor;
1964 md->disk->fops = &dm_blk_dops;
1965 md->disk->queue = md->queue;
1966 md->disk->private_data = md;
1967 sprintf(md->disk->disk_name, "dm-%d", minor);
1969 if (IS_ENABLED(CONFIG_DAX_DRIVER)) {
1970 md->dax_dev = alloc_dax(md, md->disk->disk_name,
1976 add_disk_no_queue_reg(md->disk);
1977 format_dev_t(md->name, MKDEV(_major, minor));
1979 md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
1983 md->bdev = bdget_disk(md->disk, 0);
1987 dm_stats_init(&md->stats);
1989 /* Populate the mapping, nobody knows we exist yet */
1990 spin_lock(&_minor_lock);
1991 old_md = idr_replace(&_minor_idr, md, minor);
1992 spin_unlock(&_minor_lock);
1994 BUG_ON(old_md != MINOR_ALLOCED);
1999 cleanup_mapped_device(md);
2003 module_put(THIS_MODULE);
2009 static void unlock_fs(struct mapped_device *md);
2011 static void free_dev(struct mapped_device *md)
2013 int minor = MINOR(disk_devt(md->disk));
2017 cleanup_mapped_device(md);
2019 free_table_devices(&md->table_devices);
2020 dm_stats_cleanup(&md->stats);
2023 module_put(THIS_MODULE);
2027 static int __bind_mempools(struct mapped_device *md, struct dm_table *t)
2029 struct dm_md_mempools *p = dm_table_get_md_mempools(t);
2032 if (dm_table_bio_based(t)) {
2034 * The md may already have mempools that need changing.
2035 * If so, reload bioset because front_pad may have changed
2036 * because a different table was loaded.
2038 bioset_exit(&md->bs);
2039 bioset_exit(&md->io_bs);
2041 } else if (bioset_initialized(&md->bs)) {
2043 * There's no need to reload with request-based dm
2044 * because the size of front_pad doesn't change.
2045 * Note for future: If you are to reload bioset,
2046 * prep-ed requests in the queue may refer
2047 * to bio from the old bioset, so you must walk
2048 * through the queue to unprep.
2054 bioset_initialized(&md->bs) ||
2055 bioset_initialized(&md->io_bs));
2057 ret = bioset_init_from_src(&md->bs, &p->bs);
2060 ret = bioset_init_from_src(&md->io_bs, &p->io_bs);
2062 bioset_exit(&md->bs);
2064 /* mempool bind completed, no longer need any mempools in the table */
2065 dm_table_free_md_mempools(t);
2070 * Bind a table to the device.
2072 static void event_callback(void *context)
2074 unsigned long flags;
2076 struct mapped_device *md = (struct mapped_device *) context;
2078 spin_lock_irqsave(&md->uevent_lock, flags);
2079 list_splice_init(&md->uevent_list, &uevents);
2080 spin_unlock_irqrestore(&md->uevent_lock, flags);
2082 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
2084 atomic_inc(&md->event_nr);
2085 wake_up(&md->eventq);
2086 dm_issue_global_event();
2090 * Protected by md->suspend_lock obtained by dm_swap_table().
2092 static void __set_size(struct mapped_device *md, sector_t size)
2094 lockdep_assert_held(&md->suspend_lock);
2096 set_capacity(md->disk, size);
2098 i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
2102 * Returns old map, which caller must destroy.
2104 static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
2105 struct queue_limits *limits)
2107 struct dm_table *old_map;
2108 struct request_queue *q = md->queue;
2109 bool request_based = dm_table_request_based(t);
2113 lockdep_assert_held(&md->suspend_lock);
2115 size = dm_table_get_size(t);
2118 * Wipe any geometry if the size of the table changed.
2120 if (size != dm_get_size(md))
2121 memset(&md->geometry, 0, sizeof(md->geometry));
2123 __set_size(md, size);
2125 dm_table_event_callback(t, event_callback, md);
2128 * The queue hasn't been stopped yet, if the old table type wasn't
2129 * for request-based during suspension. So stop it to prevent
2130 * I/O mapping before resume.
2131 * This must be done before setting the queue restrictions,
2132 * because request-based dm may be run just after the setting.
2137 if (request_based || md->type == DM_TYPE_NVME_BIO_BASED) {
2139 * Leverage the fact that request-based DM targets and
2140 * NVMe bio based targets are immutable singletons
2141 * - used to optimize both dm_request_fn and dm_mq_queue_rq;
2142 * and __process_bio.
2144 md->immutable_target = dm_table_get_immutable_target(t);
2147 ret = __bind_mempools(md, t);
2149 old_map = ERR_PTR(ret);
2153 old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2154 rcu_assign_pointer(md->map, (void *)t);
2155 md->immutable_target_type = dm_table_get_immutable_target_type(t);
2157 dm_table_set_restrictions(t, q, limits);
2166 * Returns unbound table for the caller to free.
2168 static struct dm_table *__unbind(struct mapped_device *md)
2170 struct dm_table *map = rcu_dereference_protected(md->map, 1);
2175 dm_table_event_callback(map, NULL, NULL);
2176 RCU_INIT_POINTER(md->map, NULL);
2183 * Constructor for a new device.
2185 int dm_create(int minor, struct mapped_device **result)
2188 struct mapped_device *md;
2190 md = alloc_dev(minor);
2194 r = dm_sysfs_init(md);
2205 * Functions to manage md->type.
2206 * All are required to hold md->type_lock.
2208 void dm_lock_md_type(struct mapped_device *md)
2210 mutex_lock(&md->type_lock);
2213 void dm_unlock_md_type(struct mapped_device *md)
2215 mutex_unlock(&md->type_lock);
2218 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type)
2220 BUG_ON(!mutex_is_locked(&md->type_lock));
2224 enum dm_queue_mode dm_get_md_type(struct mapped_device *md)
2229 struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
2231 return md->immutable_target_type;
2235 * The queue_limits are only valid as long as you have a reference
2238 struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
2240 BUG_ON(!atomic_read(&md->holders));
2241 return &md->queue->limits;
2243 EXPORT_SYMBOL_GPL(dm_get_queue_limits);
2245 static void dm_init_congested_fn(struct mapped_device *md)
2247 md->queue->backing_dev_info->congested_data = md;
2248 md->queue->backing_dev_info->congested_fn = dm_any_congested;
2252 * Setup the DM device's queue based on md's type
2254 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
2257 struct queue_limits limits;
2258 enum dm_queue_mode type = dm_get_md_type(md);
2261 case DM_TYPE_REQUEST_BASED:
2262 r = dm_mq_init_request_queue(md, t);
2264 DMERR("Cannot initialize queue for request-based dm-mq mapped device");
2267 dm_init_congested_fn(md);
2269 case DM_TYPE_BIO_BASED:
2270 case DM_TYPE_DAX_BIO_BASED:
2271 case DM_TYPE_NVME_BIO_BASED:
2272 dm_init_congested_fn(md);
2279 r = dm_calculate_queue_limits(t, &limits);
2281 DMERR("Cannot calculate initial queue limits");
2284 dm_table_set_restrictions(t, md->queue, &limits);
2285 blk_register_queue(md->disk);
2290 struct mapped_device *dm_get_md(dev_t dev)
2292 struct mapped_device *md;
2293 unsigned minor = MINOR(dev);
2295 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
2298 spin_lock(&_minor_lock);
2300 md = idr_find(&_minor_idr, minor);
2301 if (!md || md == MINOR_ALLOCED || (MINOR(disk_devt(dm_disk(md))) != minor) ||
2302 test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
2308 spin_unlock(&_minor_lock);
2312 EXPORT_SYMBOL_GPL(dm_get_md);
2314 void *dm_get_mdptr(struct mapped_device *md)
2316 return md->interface_ptr;
2319 void dm_set_mdptr(struct mapped_device *md, void *ptr)
2321 md->interface_ptr = ptr;
2324 void dm_get(struct mapped_device *md)
2326 atomic_inc(&md->holders);
2327 BUG_ON(test_bit(DMF_FREEING, &md->flags));
2330 int dm_hold(struct mapped_device *md)
2332 spin_lock(&_minor_lock);
2333 if (test_bit(DMF_FREEING, &md->flags)) {
2334 spin_unlock(&_minor_lock);
2338 spin_unlock(&_minor_lock);
2341 EXPORT_SYMBOL_GPL(dm_hold);
2343 const char *dm_device_name(struct mapped_device *md)
2347 EXPORT_SYMBOL_GPL(dm_device_name);
2349 static void __dm_destroy(struct mapped_device *md, bool wait)
2351 struct dm_table *map;
2356 spin_lock(&_minor_lock);
2357 idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
2358 set_bit(DMF_FREEING, &md->flags);
2359 spin_unlock(&_minor_lock);
2361 blk_set_queue_dying(md->queue);
2364 * Take suspend_lock so that presuspend and postsuspend methods
2365 * do not race with internal suspend.
2367 mutex_lock(&md->suspend_lock);
2368 map = dm_get_live_table(md, &srcu_idx);
2369 if (!dm_suspended_md(md)) {
2370 dm_table_presuspend_targets(map);
2371 set_bit(DMF_SUSPENDED, &md->flags);
2372 dm_table_postsuspend_targets(map);
2374 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2375 dm_put_live_table(md, srcu_idx);
2376 mutex_unlock(&md->suspend_lock);
2379 * Rare, but there may be I/O requests still going to complete,
2380 * for example. Wait for all references to disappear.
2381 * No one should increment the reference count of the mapped_device,
2382 * after the mapped_device state becomes DMF_FREEING.
2385 while (atomic_read(&md->holders))
2387 else if (atomic_read(&md->holders))
2388 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2389 dm_device_name(md), atomic_read(&md->holders));
2392 dm_table_destroy(__unbind(md));
2396 void dm_destroy(struct mapped_device *md)
2398 __dm_destroy(md, true);
2401 void dm_destroy_immediate(struct mapped_device *md)
2403 __dm_destroy(md, false);
2406 void dm_put(struct mapped_device *md)
2408 atomic_dec(&md->holders);
2410 EXPORT_SYMBOL_GPL(dm_put);
2412 static int dm_wait_for_completion(struct mapped_device *md, long task_state)
2418 prepare_to_wait(&md->wait, &wait, task_state);
2420 if (!md_in_flight(md))
2423 if (signal_pending_state(task_state, current)) {
2430 finish_wait(&md->wait, &wait);
2436 * Process the deferred bios
2438 static void dm_wq_work(struct work_struct *work)
2440 struct mapped_device *md = container_of(work, struct mapped_device,
2444 struct dm_table *map;
2446 map = dm_get_live_table(md, &srcu_idx);
2448 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
2449 spin_lock_irq(&md->deferred_lock);
2450 c = bio_list_pop(&md->deferred);
2451 spin_unlock_irq(&md->deferred_lock);
2456 if (dm_request_based(md))
2457 (void) generic_make_request(c);
2459 (void) dm_process_bio(md, map, c);
2462 dm_put_live_table(md, srcu_idx);
2465 static void dm_queue_flush(struct mapped_device *md)
2467 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2468 smp_mb__after_atomic();
2469 queue_work(md->wq, &md->work);
2473 * Swap in a new table, returning the old one for the caller to destroy.
2475 struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
2477 struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
2478 struct queue_limits limits;
2481 mutex_lock(&md->suspend_lock);
2483 /* device must be suspended */
2484 if (!dm_suspended_md(md))
2488 * If the new table has no data devices, retain the existing limits.
2489 * This helps multipath with queue_if_no_path if all paths disappear,
2490 * then new I/O is queued based on these limits, and then some paths
2493 if (dm_table_has_no_data_devices(table)) {
2494 live_map = dm_get_live_table_fast(md);
2496 limits = md->queue->limits;
2497 dm_put_live_table_fast(md);
2501 r = dm_calculate_queue_limits(table, &limits);
2508 map = __bind(md, table, &limits);
2509 dm_issue_global_event();
2512 mutex_unlock(&md->suspend_lock);
2517 * Functions to lock and unlock any filesystem running on the
2520 static int lock_fs(struct mapped_device *md)
2524 WARN_ON(md->frozen_sb);
2526 md->frozen_sb = freeze_bdev(md->bdev);
2527 if (IS_ERR(md->frozen_sb)) {
2528 r = PTR_ERR(md->frozen_sb);
2529 md->frozen_sb = NULL;
2533 set_bit(DMF_FROZEN, &md->flags);
2538 static void unlock_fs(struct mapped_device *md)
2540 if (!test_bit(DMF_FROZEN, &md->flags))
2543 thaw_bdev(md->bdev, md->frozen_sb);
2544 md->frozen_sb = NULL;
2545 clear_bit(DMF_FROZEN, &md->flags);
2549 * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG
2550 * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE
2551 * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY
2553 * If __dm_suspend returns 0, the device is completely quiescent
2554 * now. There is no request-processing activity. All new requests
2555 * are being added to md->deferred list.
2557 static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
2558 unsigned suspend_flags, long task_state,
2559 int dmf_suspended_flag)
2561 bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
2562 bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
2565 lockdep_assert_held(&md->suspend_lock);
2568 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2569 * This flag is cleared before dm_suspend returns.
2572 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2574 pr_debug("%s: suspending with flush\n", dm_device_name(md));
2577 * This gets reverted if there's an error later and the targets
2578 * provide the .presuspend_undo hook.
2580 dm_table_presuspend_targets(map);
2583 * Flush I/O to the device.
2584 * Any I/O submitted after lock_fs() may not be flushed.
2585 * noflush takes precedence over do_lockfs.
2586 * (lock_fs() flushes I/Os and waits for them to complete.)
2588 if (!noflush && do_lockfs) {
2591 dm_table_presuspend_undo_targets(map);
2597 * Here we must make sure that no processes are submitting requests
2598 * to target drivers i.e. no one may be executing
2599 * __split_and_process_bio. This is called from dm_request and
2602 * To get all processes out of __split_and_process_bio in dm_request,
2603 * we take the write lock. To prevent any process from reentering
2604 * __split_and_process_bio from dm_request and quiesce the thread
2605 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2606 * flush_workqueue(md->wq).
2608 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2610 synchronize_srcu(&md->io_barrier);
2613 * Stop md->queue before flushing md->wq in case request-based
2614 * dm defers requests to md->wq from md->queue.
2616 if (dm_request_based(md))
2617 dm_stop_queue(md->queue);
2619 flush_workqueue(md->wq);
2622 * At this point no more requests are entering target request routines.
2623 * We call dm_wait_for_completion to wait for all existing requests
2626 r = dm_wait_for_completion(md, task_state);
2628 set_bit(dmf_suspended_flag, &md->flags);
2631 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2633 synchronize_srcu(&md->io_barrier);
2635 /* were we interrupted ? */
2639 if (dm_request_based(md))
2640 dm_start_queue(md->queue);
2643 dm_table_presuspend_undo_targets(map);
2644 /* pushback list is already flushed, so skip flush */
2651 * We need to be able to change a mapping table under a mounted
2652 * filesystem. For example we might want to move some data in
2653 * the background. Before the table can be swapped with
2654 * dm_bind_table, dm_suspend must be called to flush any in
2655 * flight bios and ensure that any further io gets deferred.
2658 * Suspend mechanism in request-based dm.
2660 * 1. Flush all I/Os by lock_fs() if needed.
2661 * 2. Stop dispatching any I/O by stopping the request_queue.
2662 * 3. Wait for all in-flight I/Os to be completed or requeued.
2664 * To abort suspend, start the request_queue.
2666 int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
2668 struct dm_table *map = NULL;
2672 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2674 if (dm_suspended_md(md)) {
2679 if (dm_suspended_internally_md(md)) {
2680 /* already internally suspended, wait for internal resume */
2681 mutex_unlock(&md->suspend_lock);
2682 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2688 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2690 r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);
2694 dm_table_postsuspend_targets(map);
2697 mutex_unlock(&md->suspend_lock);
2701 static int __dm_resume(struct mapped_device *md, struct dm_table *map)
2704 int r = dm_table_resume_targets(map);
2712 * Flushing deferred I/Os must be done after targets are resumed
2713 * so that mapping of targets can work correctly.
2714 * Request-based dm is queueing the deferred I/Os in its request_queue.
2716 if (dm_request_based(md))
2717 dm_start_queue(md->queue);
2724 int dm_resume(struct mapped_device *md)
2727 struct dm_table *map = NULL;
2731 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2733 if (!dm_suspended_md(md))
2736 if (dm_suspended_internally_md(md)) {
2737 /* already internally suspended, wait for internal resume */
2738 mutex_unlock(&md->suspend_lock);
2739 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2745 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2746 if (!map || !dm_table_get_size(map))
2749 r = __dm_resume(md, map);
2753 clear_bit(DMF_SUSPENDED, &md->flags);
2755 mutex_unlock(&md->suspend_lock);
2761 * Internal suspend/resume works like userspace-driven suspend. It waits
2762 * until all bios finish and prevents issuing new bios to the target drivers.
2763 * It may be used only from the kernel.
2766 static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
2768 struct dm_table *map = NULL;
2770 lockdep_assert_held(&md->suspend_lock);
2772 if (md->internal_suspend_count++)
2773 return; /* nested internal suspend */
2775 if (dm_suspended_md(md)) {
2776 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2777 return; /* nest suspend */
2780 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2783 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
2784 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
2785 * would require changing .presuspend to return an error -- avoid this
2786 * until there is a need for more elaborate variants of internal suspend.
2788 (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
2789 DMF_SUSPENDED_INTERNALLY);
2791 dm_table_postsuspend_targets(map);
2794 static void __dm_internal_resume(struct mapped_device *md)
2796 BUG_ON(!md->internal_suspend_count);
2798 if (--md->internal_suspend_count)
2799 return; /* resume from nested internal suspend */
2801 if (dm_suspended_md(md))
2802 goto done; /* resume from nested suspend */
2805 * NOTE: existing callers don't need to call dm_table_resume_targets
2806 * (which may fail -- so best to avoid it for now by passing NULL map)
2808 (void) __dm_resume(md, NULL);
2811 clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2812 smp_mb__after_atomic();
2813 wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
2816 void dm_internal_suspend_noflush(struct mapped_device *md)
2818 mutex_lock(&md->suspend_lock);
2819 __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
2820 mutex_unlock(&md->suspend_lock);
2822 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
2824 void dm_internal_resume(struct mapped_device *md)
2826 mutex_lock(&md->suspend_lock);
2827 __dm_internal_resume(md);
2828 mutex_unlock(&md->suspend_lock);
2830 EXPORT_SYMBOL_GPL(dm_internal_resume);
2833 * Fast variants of internal suspend/resume hold md->suspend_lock,
2834 * which prevents interaction with userspace-driven suspend.
2837 void dm_internal_suspend_fast(struct mapped_device *md)
2839 mutex_lock(&md->suspend_lock);
2840 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2843 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2844 synchronize_srcu(&md->io_barrier);
2845 flush_workqueue(md->wq);
2846 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
2848 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
2850 void dm_internal_resume_fast(struct mapped_device *md)
2852 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2858 mutex_unlock(&md->suspend_lock);
2860 EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
2862 /*-----------------------------------------------------------------
2863 * Event notification.
2864 *---------------------------------------------------------------*/
2865 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
2868 char udev_cookie[DM_COOKIE_LENGTH];
2869 char *envp[] = { udev_cookie, NULL };
2872 return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
2874 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
2875 DM_COOKIE_ENV_VAR_NAME, cookie);
2876 return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
2881 uint32_t dm_next_uevent_seq(struct mapped_device *md)
2883 return atomic_add_return(1, &md->uevent_seq);
2886 uint32_t dm_get_event_nr(struct mapped_device *md)
2888 return atomic_read(&md->event_nr);
2891 int dm_wait_event(struct mapped_device *md, int event_nr)
2893 return wait_event_interruptible(md->eventq,
2894 (event_nr != atomic_read(&md->event_nr)));
2897 void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
2899 unsigned long flags;
2901 spin_lock_irqsave(&md->uevent_lock, flags);
2902 list_add(elist, &md->uevent_list);
2903 spin_unlock_irqrestore(&md->uevent_lock, flags);
2907 * The gendisk is only valid as long as you have a reference
2910 struct gendisk *dm_disk(struct mapped_device *md)
2914 EXPORT_SYMBOL_GPL(dm_disk);
2916 struct kobject *dm_kobject(struct mapped_device *md)
2918 return &md->kobj_holder.kobj;
2921 struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
2923 struct mapped_device *md;
2925 md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
2927 spin_lock(&_minor_lock);
2928 if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
2934 spin_unlock(&_minor_lock);
2939 int dm_suspended_md(struct mapped_device *md)
2941 return test_bit(DMF_SUSPENDED, &md->flags);
2944 int dm_suspended_internally_md(struct mapped_device *md)
2946 return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2949 int dm_test_deferred_remove_flag(struct mapped_device *md)
2951 return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
2954 int dm_suspended(struct dm_target *ti)
2956 return dm_suspended_md(dm_table_get_md(ti->table));
2958 EXPORT_SYMBOL_GPL(dm_suspended);
2960 int dm_noflush_suspending(struct dm_target *ti)
2962 return __noflush_suspending(dm_table_get_md(ti->table));
2964 EXPORT_SYMBOL_GPL(dm_noflush_suspending);
2966 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
2967 unsigned integrity, unsigned per_io_data_size,
2968 unsigned min_pool_size)
2970 struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
2971 unsigned int pool_size = 0;
2972 unsigned int front_pad, io_front_pad;
2979 case DM_TYPE_BIO_BASED:
2980 case DM_TYPE_DAX_BIO_BASED:
2981 case DM_TYPE_NVME_BIO_BASED:
2982 pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
2983 front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
2984 io_front_pad = roundup(front_pad, __alignof__(struct dm_io)) + offsetof(struct dm_io, tio);
2985 ret = bioset_init(&pools->io_bs, pool_size, io_front_pad, 0);
2988 if (integrity && bioset_integrity_create(&pools->io_bs, pool_size))
2991 case DM_TYPE_REQUEST_BASED:
2992 pool_size = max(dm_get_reserved_rq_based_ios(), min_pool_size);
2993 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
2994 /* per_io_data_size is used for blk-mq pdu at queue allocation */
3000 ret = bioset_init(&pools->bs, pool_size, front_pad, 0);
3004 if (integrity && bioset_integrity_create(&pools->bs, pool_size))
3010 dm_free_md_mempools(pools);
3015 void dm_free_md_mempools(struct dm_md_mempools *pools)
3020 bioset_exit(&pools->bs);
3021 bioset_exit(&pools->io_bs);
3033 static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
3036 struct mapped_device *md = bdev->bd_disk->private_data;
3037 struct dm_table *table;
3038 struct dm_target *ti;
3039 int ret = -ENOTTY, srcu_idx;
3041 table = dm_get_live_table(md, &srcu_idx);
3042 if (!table || !dm_table_get_size(table))
3045 /* We only support devices that have a single target */
3046 if (dm_table_get_num_targets(table) != 1)
3048 ti = dm_table_get_target(table, 0);
3051 if (!ti->type->iterate_devices)
3054 ret = ti->type->iterate_devices(ti, fn, data);
3056 dm_put_live_table(md, srcu_idx);
3061 * For register / unregister we need to manually call out to every path.
3063 static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev,
3064 sector_t start, sector_t len, void *data)
3066 struct dm_pr *pr = data;
3067 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
3069 if (!ops || !ops->pr_register)
3071 return ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
3074 static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
3085 ret = dm_call_pr(bdev, __dm_pr_register, &pr);
3086 if (ret && new_key) {
3087 /* unregister all paths if we failed to register any path */
3088 pr.old_key = new_key;
3091 pr.fail_early = false;
3092 dm_call_pr(bdev, __dm_pr_register, &pr);
3098 static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
3101 struct mapped_device *md = bdev->bd_disk->private_data;
3102 const struct pr_ops *ops;
3105 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3109 ops = bdev->bd_disk->fops->pr_ops;
3110 if (ops && ops->pr_reserve)
3111 r = ops->pr_reserve(bdev, key, type, flags);
3115 dm_unprepare_ioctl(md, srcu_idx);
3119 static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
3121 struct mapped_device *md = bdev->bd_disk->private_data;
3122 const struct pr_ops *ops;
3125 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3129 ops = bdev->bd_disk->fops->pr_ops;
3130 if (ops && ops->pr_release)
3131 r = ops->pr_release(bdev, key, type);
3135 dm_unprepare_ioctl(md, srcu_idx);
3139 static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
3140 enum pr_type type, bool abort)
3142 struct mapped_device *md = bdev->bd_disk->private_data;
3143 const struct pr_ops *ops;
3146 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3150 ops = bdev->bd_disk->fops->pr_ops;
3151 if (ops && ops->pr_preempt)
3152 r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
3156 dm_unprepare_ioctl(md, srcu_idx);
3160 static int dm_pr_clear(struct block_device *bdev, u64 key)
3162 struct mapped_device *md = bdev->bd_disk->private_data;
3163 const struct pr_ops *ops;
3166 r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
3170 ops = bdev->bd_disk->fops->pr_ops;
3171 if (ops && ops->pr_clear)
3172 r = ops->pr_clear(bdev, key);
3176 dm_unprepare_ioctl(md, srcu_idx);
3180 static const struct pr_ops dm_pr_ops = {
3181 .pr_register = dm_pr_register,
3182 .pr_reserve = dm_pr_reserve,
3183 .pr_release = dm_pr_release,
3184 .pr_preempt = dm_pr_preempt,
3185 .pr_clear = dm_pr_clear,
3188 static const struct block_device_operations dm_blk_dops = {
3189 .open = dm_blk_open,
3190 .release = dm_blk_close,
3191 .ioctl = dm_blk_ioctl,
3192 .getgeo = dm_blk_getgeo,
3193 .report_zones = dm_blk_report_zones,
3194 .pr_ops = &dm_pr_ops,
3195 .owner = THIS_MODULE
3198 static const struct dax_operations dm_dax_ops = {
3199 .direct_access = dm_dax_direct_access,
3200 .dax_supported = dm_dax_supported,
3201 .copy_from_iter = dm_dax_copy_from_iter,
3202 .copy_to_iter = dm_dax_copy_to_iter,
3208 module_init(dm_init);
3209 module_exit(dm_exit);
3211 module_param(major, uint, 0);
3212 MODULE_PARM_DESC(major, "The major number of the device mapper");
3214 module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
3215 MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
3217 module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
3218 MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
3220 MODULE_DESCRIPTION(DM_NAME " driver");
3221 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3222 MODULE_LICENSE("GPL");