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>
28 #define DM_MSG_PREFIX "core"
32 * ratelimit state to be used in DMXXX_LIMIT().
34 DEFINE_RATELIMIT_STATE(dm_ratelimit_state,
35 DEFAULT_RATELIMIT_INTERVAL,
36 DEFAULT_RATELIMIT_BURST);
37 EXPORT_SYMBOL(dm_ratelimit_state);
41 * Cookies are numeric values sent with CHANGE and REMOVE
42 * uevents while resuming, removing or renaming the device.
44 #define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
45 #define DM_COOKIE_LENGTH 24
47 static const char *_name = DM_NAME;
49 static unsigned int major = 0;
50 static unsigned int _major = 0;
52 static DEFINE_IDR(_minor_idr);
54 static DEFINE_SPINLOCK(_minor_lock);
56 static void do_deferred_remove(struct work_struct *w);
58 static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
60 static struct workqueue_struct *deferred_remove_workqueue;
62 atomic_t dm_global_event_nr = ATOMIC_INIT(0);
63 DECLARE_WAIT_QUEUE_HEAD(dm_global_eventq);
66 * One of these is allocated per bio.
69 struct mapped_device *md;
73 unsigned long start_time;
74 spinlock_t endio_lock;
75 struct dm_stats_aux stats_aux;
78 #define MINOR_ALLOCED ((void *)-1)
81 * Bits for the md->flags field.
83 #define DMF_BLOCK_IO_FOR_SUSPEND 0
84 #define DMF_SUSPENDED 1
87 #define DMF_DELETING 4
88 #define DMF_NOFLUSH_SUSPENDING 5
89 #define DMF_DEFERRED_REMOVE 6
90 #define DMF_SUSPENDED_INTERNALLY 7
92 #define DM_NUMA_NODE NUMA_NO_NODE
93 static int dm_numa_node = DM_NUMA_NODE;
96 * For mempools pre-allocation at the table loading time.
98 struct dm_md_mempools {
103 struct table_device {
104 struct list_head list;
106 struct dm_dev dm_dev;
109 static struct kmem_cache *_io_cache;
110 static struct kmem_cache *_rq_tio_cache;
111 static struct kmem_cache *_rq_cache;
114 * Bio-based DM's mempools' reserved IOs set by the user.
116 #define RESERVED_BIO_BASED_IOS 16
117 static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
119 static int __dm_get_module_param_int(int *module_param, int min, int max)
121 int param = ACCESS_ONCE(*module_param);
122 int modified_param = 0;
123 bool modified = true;
126 modified_param = min;
127 else if (param > max)
128 modified_param = max;
133 (void)cmpxchg(module_param, param, modified_param);
134 param = modified_param;
140 unsigned __dm_get_module_param(unsigned *module_param,
141 unsigned def, unsigned max)
143 unsigned param = ACCESS_ONCE(*module_param);
144 unsigned modified_param = 0;
147 modified_param = def;
148 else if (param > max)
149 modified_param = max;
151 if (modified_param) {
152 (void)cmpxchg(module_param, param, modified_param);
153 param = modified_param;
159 unsigned dm_get_reserved_bio_based_ios(void)
161 return __dm_get_module_param(&reserved_bio_based_ios,
162 RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS);
164 EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
166 static unsigned dm_get_numa_node(void)
168 return __dm_get_module_param_int(&dm_numa_node,
169 DM_NUMA_NODE, num_online_nodes() - 1);
172 static int __init local_init(void)
176 /* allocate a slab for the dm_ios */
177 _io_cache = KMEM_CACHE(dm_io, 0);
181 _rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
183 goto out_free_io_cache;
185 _rq_cache = kmem_cache_create("dm_old_clone_request", sizeof(struct request),
186 __alignof__(struct request), 0, NULL);
188 goto out_free_rq_tio_cache;
190 r = dm_uevent_init();
192 goto out_free_rq_cache;
194 deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
195 if (!deferred_remove_workqueue) {
197 goto out_uevent_exit;
201 r = register_blkdev(_major, _name);
203 goto out_free_workqueue;
211 destroy_workqueue(deferred_remove_workqueue);
215 kmem_cache_destroy(_rq_cache);
216 out_free_rq_tio_cache:
217 kmem_cache_destroy(_rq_tio_cache);
219 kmem_cache_destroy(_io_cache);
224 static void local_exit(void)
226 flush_scheduled_work();
227 destroy_workqueue(deferred_remove_workqueue);
229 kmem_cache_destroy(_rq_cache);
230 kmem_cache_destroy(_rq_tio_cache);
231 kmem_cache_destroy(_io_cache);
232 unregister_blkdev(_major, _name);
237 DMINFO("cleaned up");
240 static int (*_inits[])(void) __initdata = {
251 static void (*_exits[])(void) = {
262 static int __init dm_init(void)
264 const int count = ARRAY_SIZE(_inits);
268 for (i = 0; i < count; i++) {
283 static void __exit dm_exit(void)
285 int i = ARRAY_SIZE(_exits);
291 * Should be empty by this point.
293 idr_destroy(&_minor_idr);
297 * Block device functions
299 int dm_deleting_md(struct mapped_device *md)
301 return test_bit(DMF_DELETING, &md->flags);
304 static int dm_blk_open(struct block_device *bdev, fmode_t mode)
306 struct mapped_device *md;
308 spin_lock(&_minor_lock);
310 md = bdev->bd_disk->private_data;
314 if (test_bit(DMF_FREEING, &md->flags) ||
315 dm_deleting_md(md)) {
321 atomic_inc(&md->open_count);
323 spin_unlock(&_minor_lock);
325 return md ? 0 : -ENXIO;
328 static void dm_blk_close(struct gendisk *disk, fmode_t mode)
330 struct mapped_device *md;
332 spin_lock(&_minor_lock);
334 md = disk->private_data;
338 if (atomic_dec_and_test(&md->open_count) &&
339 (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
340 queue_work(deferred_remove_workqueue, &deferred_remove_work);
344 spin_unlock(&_minor_lock);
347 int dm_open_count(struct mapped_device *md)
349 return atomic_read(&md->open_count);
353 * Guarantees nothing is using the device before it's deleted.
355 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
359 spin_lock(&_minor_lock);
361 if (dm_open_count(md)) {
364 set_bit(DMF_DEFERRED_REMOVE, &md->flags);
365 } else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
368 set_bit(DMF_DELETING, &md->flags);
370 spin_unlock(&_minor_lock);
375 int dm_cancel_deferred_remove(struct mapped_device *md)
379 spin_lock(&_minor_lock);
381 if (test_bit(DMF_DELETING, &md->flags))
384 clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
386 spin_unlock(&_minor_lock);
391 static void do_deferred_remove(struct work_struct *w)
393 dm_deferred_remove();
396 sector_t dm_get_size(struct mapped_device *md)
398 return get_capacity(md->disk);
401 struct request_queue *dm_get_md_queue(struct mapped_device *md)
406 struct dm_stats *dm_get_stats(struct mapped_device *md)
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_grab_bdev_for_ioctl(struct mapped_device *md,
419 struct block_device **bdev,
422 struct dm_target *tgt;
423 struct dm_table *map;
428 map = dm_get_live_table(md, &srcu_idx);
429 if (!map || !dm_table_get_size(map))
432 /* We only support devices that have a single target */
433 if (dm_table_get_num_targets(map) != 1)
436 tgt = dm_table_get_target(map, 0);
437 if (!tgt->type->prepare_ioctl)
440 if (dm_suspended_md(md)) {
445 r = tgt->type->prepare_ioctl(tgt, bdev, mode);
450 dm_put_live_table(md, srcu_idx);
454 dm_put_live_table(md, srcu_idx);
455 if (r == -ENOTCONN && !fatal_signal_pending(current)) {
462 static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
463 unsigned int cmd, unsigned long arg)
465 struct mapped_device *md = bdev->bd_disk->private_data;
468 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
474 * Target determined this ioctl is being issued against a
475 * subset of the parent bdev; require extra privileges.
477 if (!capable(CAP_SYS_RAWIO)) {
479 "%s: sending ioctl %x to DM device without required privilege.",
486 r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
492 static struct dm_io *alloc_io(struct mapped_device *md)
494 return mempool_alloc(md->io_pool, GFP_NOIO);
497 static void free_io(struct mapped_device *md, struct dm_io *io)
499 mempool_free(io, md->io_pool);
502 static void free_tio(struct dm_target_io *tio)
504 bio_put(&tio->clone);
507 int md_in_flight(struct mapped_device *md)
509 return atomic_read(&md->pending[READ]) +
510 atomic_read(&md->pending[WRITE]);
513 static void start_io_acct(struct dm_io *io)
515 struct mapped_device *md = io->md;
516 struct bio *bio = io->bio;
518 int rw = bio_data_dir(bio);
520 io->start_time = jiffies;
522 cpu = part_stat_lock();
523 part_round_stats(cpu, &dm_disk(md)->part0);
525 atomic_set(&dm_disk(md)->part0.in_flight[rw],
526 atomic_inc_return(&md->pending[rw]));
528 if (unlikely(dm_stats_used(&md->stats)))
529 dm_stats_account_io(&md->stats, bio_data_dir(bio),
530 bio->bi_iter.bi_sector, bio_sectors(bio),
531 false, 0, &io->stats_aux);
534 static void end_io_acct(struct dm_io *io)
536 struct mapped_device *md = io->md;
537 struct bio *bio = io->bio;
538 unsigned long duration = jiffies - io->start_time;
540 int rw = bio_data_dir(bio);
542 generic_end_io_acct(rw, &dm_disk(md)->part0, io->start_time);
544 if (unlikely(dm_stats_used(&md->stats)))
545 dm_stats_account_io(&md->stats, bio_data_dir(bio),
546 bio->bi_iter.bi_sector, bio_sectors(bio),
547 true, duration, &io->stats_aux);
550 * After this is decremented the bio must not be touched if it is
553 pending = atomic_dec_return(&md->pending[rw]);
554 atomic_set(&dm_disk(md)->part0.in_flight[rw], pending);
555 pending += atomic_read(&md->pending[rw^0x1]);
557 /* nudge anyone waiting on suspend queue */
563 * Add the bio to the list of deferred io.
565 static void queue_io(struct mapped_device *md, struct bio *bio)
569 spin_lock_irqsave(&md->deferred_lock, flags);
570 bio_list_add(&md->deferred, bio);
571 spin_unlock_irqrestore(&md->deferred_lock, flags);
572 queue_work(md->wq, &md->work);
576 * Everyone (including functions in this file), should use this
577 * function to access the md->map field, and make sure they call
578 * dm_put_live_table() when finished.
580 struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
582 *srcu_idx = srcu_read_lock(&md->io_barrier);
584 return srcu_dereference(md->map, &md->io_barrier);
587 void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
589 srcu_read_unlock(&md->io_barrier, srcu_idx);
592 void dm_sync_table(struct mapped_device *md)
594 synchronize_srcu(&md->io_barrier);
595 synchronize_rcu_expedited();
599 * A fast alternative to dm_get_live_table/dm_put_live_table.
600 * The caller must not block between these two functions.
602 static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
605 return rcu_dereference(md->map);
608 static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
614 * Open a table device so we can use it as a map destination.
616 static int open_table_device(struct table_device *td, dev_t dev,
617 struct mapped_device *md)
619 static char *_claim_ptr = "I belong to device-mapper";
620 struct block_device *bdev;
624 BUG_ON(td->dm_dev.bdev);
626 bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _claim_ptr);
628 return PTR_ERR(bdev);
630 r = bd_link_disk_holder(bdev, dm_disk(md));
632 blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
636 td->dm_dev.bdev = bdev;
637 td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
642 * Close a table device that we've been using.
644 static void close_table_device(struct table_device *td, struct mapped_device *md)
646 if (!td->dm_dev.bdev)
649 bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
650 blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
651 put_dax(td->dm_dev.dax_dev);
652 td->dm_dev.bdev = NULL;
653 td->dm_dev.dax_dev = NULL;
656 static struct table_device *find_table_device(struct list_head *l, dev_t dev,
658 struct table_device *td;
660 list_for_each_entry(td, l, list)
661 if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
667 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
668 struct dm_dev **result) {
670 struct table_device *td;
672 mutex_lock(&md->table_devices_lock);
673 td = find_table_device(&md->table_devices, dev, mode);
675 td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
677 mutex_unlock(&md->table_devices_lock);
681 td->dm_dev.mode = mode;
682 td->dm_dev.bdev = NULL;
684 if ((r = open_table_device(td, dev, md))) {
685 mutex_unlock(&md->table_devices_lock);
690 format_dev_t(td->dm_dev.name, dev);
692 atomic_set(&td->count, 0);
693 list_add(&td->list, &md->table_devices);
695 atomic_inc(&td->count);
696 mutex_unlock(&md->table_devices_lock);
698 *result = &td->dm_dev;
701 EXPORT_SYMBOL_GPL(dm_get_table_device);
703 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
705 struct table_device *td = container_of(d, struct table_device, dm_dev);
707 mutex_lock(&md->table_devices_lock);
708 if (atomic_dec_and_test(&td->count)) {
709 close_table_device(td, md);
713 mutex_unlock(&md->table_devices_lock);
715 EXPORT_SYMBOL(dm_put_table_device);
717 static void free_table_devices(struct list_head *devices)
719 struct list_head *tmp, *next;
721 list_for_each_safe(tmp, next, devices) {
722 struct table_device *td = list_entry(tmp, struct table_device, list);
724 DMWARN("dm_destroy: %s still exists with %d references",
725 td->dm_dev.name, atomic_read(&td->count));
731 * Get the geometry associated with a dm device
733 int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
741 * Set the geometry of a device.
743 int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
745 sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
747 if (geo->start > sz) {
748 DMWARN("Start sector is beyond the geometry limits.");
757 /*-----------------------------------------------------------------
759 * A more elegant soln is in the works that uses the queue
760 * merge fn, unfortunately there are a couple of changes to
761 * the block layer that I want to make for this. So in the
762 * interests of getting something for people to use I give
763 * you this clearly demarcated crap.
764 *---------------------------------------------------------------*/
766 static int __noflush_suspending(struct mapped_device *md)
768 return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
772 * Decrements the number of outstanding ios that a bio has been
773 * cloned into, completing the original io if necc.
775 static void dec_pending(struct dm_io *io, blk_status_t error)
778 blk_status_t io_error;
780 struct mapped_device *md = io->md;
782 /* Push-back supersedes any I/O errors */
783 if (unlikely(error)) {
784 spin_lock_irqsave(&io->endio_lock, flags);
785 if (!(io->status == BLK_STS_DM_REQUEUE &&
786 __noflush_suspending(md)))
788 spin_unlock_irqrestore(&io->endio_lock, flags);
791 if (atomic_dec_and_test(&io->io_count)) {
792 if (io->status == BLK_STS_DM_REQUEUE) {
794 * Target requested pushing back the I/O.
796 spin_lock_irqsave(&md->deferred_lock, flags);
797 if (__noflush_suspending(md))
798 bio_list_add_head(&md->deferred, io->bio);
800 /* noflush suspend was interrupted. */
801 io->status = BLK_STS_IOERR;
802 spin_unlock_irqrestore(&md->deferred_lock, flags);
805 io_error = io->status;
810 if (io_error == BLK_STS_DM_REQUEUE)
813 if ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size) {
815 * Preflush done for flush with data, reissue
816 * without REQ_PREFLUSH.
818 bio->bi_opf &= ~REQ_PREFLUSH;
821 /* done with normal IO or empty flush */
822 bio->bi_status = io_error;
828 void disable_write_same(struct mapped_device *md)
830 struct queue_limits *limits = dm_get_queue_limits(md);
832 /* device doesn't really support WRITE SAME, disable it */
833 limits->max_write_same_sectors = 0;
836 void disable_write_zeroes(struct mapped_device *md)
838 struct queue_limits *limits = dm_get_queue_limits(md);
840 /* device doesn't really support WRITE ZEROES, disable it */
841 limits->max_write_zeroes_sectors = 0;
844 static void clone_endio(struct bio *bio)
846 blk_status_t error = bio->bi_status;
847 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
848 struct dm_io *io = tio->io;
849 struct mapped_device *md = tio->io->md;
850 dm_endio_fn endio = tio->ti->type->end_io;
852 if (unlikely(error == BLK_STS_TARGET)) {
853 if (bio_op(bio) == REQ_OP_WRITE_SAME &&
854 !bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors)
855 disable_write_same(md);
856 if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
857 !bdev_get_queue(bio->bi_bdev)->limits.max_write_zeroes_sectors)
858 disable_write_zeroes(md);
862 int r = endio(tio->ti, bio, &error);
864 case DM_ENDIO_REQUEUE:
865 error = BLK_STS_DM_REQUEUE;
869 case DM_ENDIO_INCOMPLETE:
870 /* The target will handle the io */
873 DMWARN("unimplemented target endio return value: %d", r);
879 dec_pending(io, error);
883 * Return maximum size of I/O possible at the supplied sector up to the current
886 static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
888 sector_t target_offset = dm_target_offset(ti, sector);
890 return ti->len - target_offset;
893 static sector_t max_io_len(sector_t sector, struct dm_target *ti)
895 sector_t len = max_io_len_target_boundary(sector, ti);
896 sector_t offset, max_len;
899 * Does the target need to split even further?
901 if (ti->max_io_len) {
902 offset = dm_target_offset(ti, sector);
903 if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
904 max_len = sector_div(offset, ti->max_io_len);
906 max_len = offset & (ti->max_io_len - 1);
907 max_len = ti->max_io_len - max_len;
916 int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
918 if (len > UINT_MAX) {
919 DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
920 (unsigned long long)len, UINT_MAX);
921 ti->error = "Maximum size of target IO is too large";
925 ti->max_io_len = (uint32_t) len;
929 EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
931 static struct dm_target *dm_dax_get_live_target(struct mapped_device *md,
932 sector_t sector, int *srcu_idx)
934 struct dm_table *map;
935 struct dm_target *ti;
937 map = dm_get_live_table(md, srcu_idx);
941 ti = dm_table_find_target(map, sector);
942 if (!dm_target_is_valid(ti))
948 static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
949 long nr_pages, void **kaddr, pfn_t *pfn)
951 struct mapped_device *md = dax_get_private(dax_dev);
952 sector_t sector = pgoff * PAGE_SECTORS;
953 struct dm_target *ti;
954 long len, ret = -EIO;
957 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
961 if (!ti->type->direct_access)
963 len = max_io_len(sector, ti) / PAGE_SECTORS;
966 nr_pages = min(len, nr_pages);
967 if (ti->type->direct_access)
968 ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn);
971 dm_put_live_table(md, srcu_idx);
976 static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
977 void *addr, size_t bytes, struct iov_iter *i)
979 struct mapped_device *md = dax_get_private(dax_dev);
980 sector_t sector = pgoff * PAGE_SECTORS;
981 struct dm_target *ti;
985 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
989 if (!ti->type->dax_copy_from_iter) {
990 ret = copy_from_iter(addr, bytes, i);
993 ret = ti->type->dax_copy_from_iter(ti, pgoff, addr, bytes, i);
995 dm_put_live_table(md, srcu_idx);
1000 static void dm_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
1003 struct mapped_device *md = dax_get_private(dax_dev);
1004 sector_t sector = pgoff * PAGE_SECTORS;
1005 struct dm_target *ti;
1008 ti = dm_dax_get_live_target(md, sector, &srcu_idx);
1012 if (ti->type->dax_flush)
1013 ti->type->dax_flush(ti, pgoff, addr, size);
1015 dm_put_live_table(md, srcu_idx);
1019 * A target may call dm_accept_partial_bio only from the map routine. It is
1020 * allowed for all bio types except REQ_PREFLUSH.
1022 * dm_accept_partial_bio informs the dm that the target only wants to process
1023 * additional n_sectors sectors of the bio and the rest of the data should be
1024 * sent in a next bio.
1026 * A diagram that explains the arithmetics:
1027 * +--------------------+---------------+-------+
1029 * +--------------------+---------------+-------+
1031 * <-------------- *tio->len_ptr --------------->
1032 * <------- bi_size ------->
1035 * Region 1 was already iterated over with bio_advance or similar function.
1036 * (it may be empty if the target doesn't use bio_advance)
1037 * Region 2 is the remaining bio size that the target wants to process.
1038 * (it may be empty if region 1 is non-empty, although there is no reason
1040 * The target requires that region 3 is to be sent in the next bio.
1042 * If the target wants to receive multiple copies of the bio (via num_*bios, etc),
1043 * the partially processed part (the sum of regions 1+2) must be the same for all
1044 * copies of the bio.
1046 void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
1048 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1049 unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
1050 BUG_ON(bio->bi_opf & REQ_PREFLUSH);
1051 BUG_ON(bi_size > *tio->len_ptr);
1052 BUG_ON(n_sectors > bi_size);
1053 *tio->len_ptr -= bi_size - n_sectors;
1054 bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
1056 EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
1059 * The zone descriptors obtained with a zone report indicate
1060 * zone positions within the target device. The zone descriptors
1061 * must be remapped to match their position within the dm device.
1062 * A target may call dm_remap_zone_report after completion of a
1063 * REQ_OP_ZONE_REPORT bio to remap the zone descriptors obtained
1064 * from the target device mapping to the dm device.
1066 void dm_remap_zone_report(struct dm_target *ti, struct bio *bio, sector_t start)
1068 #ifdef CONFIG_BLK_DEV_ZONED
1069 struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
1070 struct bio *report_bio = tio->io->bio;
1071 struct blk_zone_report_hdr *hdr = NULL;
1072 struct blk_zone *zone;
1073 unsigned int nr_rep = 0;
1075 struct bio_vec bvec;
1076 struct bvec_iter iter;
1083 * Remap the start sector of the reported zones. For sequential zones,
1084 * also remap the write pointer position.
1086 bio_for_each_segment(bvec, report_bio, iter) {
1087 addr = kmap_atomic(bvec.bv_page);
1089 /* Remember the report header in the first page */
1092 ofst = sizeof(struct blk_zone_report_hdr);
1096 /* Set zones start sector */
1097 while (hdr->nr_zones && ofst < bvec.bv_len) {
1099 if (zone->start >= start + ti->len) {
1103 zone->start = zone->start + ti->begin - start;
1104 if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
1105 if (zone->cond == BLK_ZONE_COND_FULL)
1106 zone->wp = zone->start + zone->len;
1107 else if (zone->cond == BLK_ZONE_COND_EMPTY)
1108 zone->wp = zone->start;
1110 zone->wp = zone->wp + ti->begin - start;
1112 ofst += sizeof(struct blk_zone);
1118 kunmap_atomic(addr);
1125 hdr->nr_zones = nr_rep;
1129 bio_advance(report_bio, report_bio->bi_iter.bi_size);
1131 #else /* !CONFIG_BLK_DEV_ZONED */
1132 bio->bi_status = BLK_STS_NOTSUPP;
1135 EXPORT_SYMBOL_GPL(dm_remap_zone_report);
1138 * Flush current->bio_list when the target map method blocks.
1139 * This fixes deadlocks in snapshot and possibly in other targets.
1142 struct blk_plug plug;
1143 struct blk_plug_cb cb;
1146 static void flush_current_bio_list(struct blk_plug_cb *cb, bool from_schedule)
1148 struct dm_offload *o = container_of(cb, struct dm_offload, cb);
1149 struct bio_list list;
1153 INIT_LIST_HEAD(&o->cb.list);
1155 if (unlikely(!current->bio_list))
1158 for (i = 0; i < 2; i++) {
1159 list = current->bio_list[i];
1160 bio_list_init(¤t->bio_list[i]);
1162 while ((bio = bio_list_pop(&list))) {
1163 struct bio_set *bs = bio->bi_pool;
1164 if (unlikely(!bs) || bs == fs_bio_set ||
1165 !bs->rescue_workqueue) {
1166 bio_list_add(¤t->bio_list[i], bio);
1170 spin_lock(&bs->rescue_lock);
1171 bio_list_add(&bs->rescue_list, bio);
1172 queue_work(bs->rescue_workqueue, &bs->rescue_work);
1173 spin_unlock(&bs->rescue_lock);
1178 static void dm_offload_start(struct dm_offload *o)
1180 blk_start_plug(&o->plug);
1181 o->cb.callback = flush_current_bio_list;
1182 list_add(&o->cb.list, ¤t->plug->cb_list);
1185 static void dm_offload_end(struct dm_offload *o)
1187 list_del(&o->cb.list);
1188 blk_finish_plug(&o->plug);
1191 static void __map_bio(struct dm_target_io *tio)
1195 struct dm_offload o;
1196 struct bio *clone = &tio->clone;
1197 struct dm_target *ti = tio->ti;
1199 clone->bi_end_io = clone_endio;
1202 * Map the clone. If r == 0 we don't need to do
1203 * anything, the target has assumed ownership of
1206 atomic_inc(&tio->io->io_count);
1207 sector = clone->bi_iter.bi_sector;
1209 dm_offload_start(&o);
1210 r = ti->type->map(ti, clone);
1214 case DM_MAPIO_SUBMITTED:
1216 case DM_MAPIO_REMAPPED:
1217 /* the bio has been remapped so dispatch it */
1218 trace_block_bio_remap(bdev_get_queue(clone->bi_bdev), clone,
1219 tio->io->bio->bi_bdev->bd_dev, sector);
1220 generic_make_request(clone);
1223 dec_pending(tio->io, BLK_STS_IOERR);
1226 case DM_MAPIO_REQUEUE:
1227 dec_pending(tio->io, BLK_STS_DM_REQUEUE);
1231 DMWARN("unimplemented target map return value: %d", r);
1237 struct mapped_device *md;
1238 struct dm_table *map;
1242 unsigned sector_count;
1245 static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
1247 bio->bi_iter.bi_sector = sector;
1248 bio->bi_iter.bi_size = to_bytes(len);
1252 * Creates a bio that consists of range of complete bvecs.
1254 static int clone_bio(struct dm_target_io *tio, struct bio *bio,
1255 sector_t sector, unsigned len)
1257 struct bio *clone = &tio->clone;
1259 __bio_clone_fast(clone, bio);
1261 if (unlikely(bio_integrity(bio) != NULL)) {
1264 if (unlikely(!dm_target_has_integrity(tio->ti->type) &&
1265 !dm_target_passes_integrity(tio->ti->type))) {
1266 DMWARN("%s: the target %s doesn't support integrity data.",
1267 dm_device_name(tio->io->md),
1268 tio->ti->type->name);
1272 r = bio_integrity_clone(clone, bio, GFP_NOIO);
1277 if (bio_op(bio) != REQ_OP_ZONE_REPORT)
1278 bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
1279 clone->bi_iter.bi_size = to_bytes(len);
1281 if (unlikely(bio_integrity(bio) != NULL))
1282 bio_integrity_trim(clone);
1287 static struct dm_target_io *alloc_tio(struct clone_info *ci,
1288 struct dm_target *ti,
1289 unsigned target_bio_nr)
1291 struct dm_target_io *tio;
1294 clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
1295 tio = container_of(clone, struct dm_target_io, clone);
1299 tio->target_bio_nr = target_bio_nr;
1304 static void __clone_and_map_simple_bio(struct clone_info *ci,
1305 struct dm_target *ti,
1306 unsigned target_bio_nr, unsigned *len)
1308 struct dm_target_io *tio = alloc_tio(ci, ti, target_bio_nr);
1309 struct bio *clone = &tio->clone;
1313 __bio_clone_fast(clone, ci->bio);
1315 bio_setup_sector(clone, ci->sector, *len);
1320 static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
1321 unsigned num_bios, unsigned *len)
1323 unsigned target_bio_nr;
1325 for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++)
1326 __clone_and_map_simple_bio(ci, ti, target_bio_nr, len);
1329 static int __send_empty_flush(struct clone_info *ci)
1331 unsigned target_nr = 0;
1332 struct dm_target *ti;
1334 BUG_ON(bio_has_data(ci->bio));
1335 while ((ti = dm_table_get_target(ci->map, target_nr++)))
1336 __send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
1341 static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
1342 sector_t sector, unsigned *len)
1344 struct bio *bio = ci->bio;
1345 struct dm_target_io *tio;
1346 unsigned target_bio_nr;
1347 unsigned num_target_bios = 1;
1351 * Does the target want to receive duplicate copies of the bio?
1353 if (bio_data_dir(bio) == WRITE && ti->num_write_bios)
1354 num_target_bios = ti->num_write_bios(ti, bio);
1356 for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
1357 tio = alloc_tio(ci, ti, target_bio_nr);
1359 r = clone_bio(tio, bio, sector, *len);
1370 typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
1372 static unsigned get_num_discard_bios(struct dm_target *ti)
1374 return ti->num_discard_bios;
1377 static unsigned get_num_write_same_bios(struct dm_target *ti)
1379 return ti->num_write_same_bios;
1382 static unsigned get_num_write_zeroes_bios(struct dm_target *ti)
1384 return ti->num_write_zeroes_bios;
1387 typedef bool (*is_split_required_fn)(struct dm_target *ti);
1389 static bool is_split_required_for_discard(struct dm_target *ti)
1391 return ti->split_discard_bios;
1394 static int __send_changing_extent_only(struct clone_info *ci,
1395 get_num_bios_fn get_num_bios,
1396 is_split_required_fn is_split_required)
1398 struct dm_target *ti;
1403 ti = dm_table_find_target(ci->map, ci->sector);
1404 if (!dm_target_is_valid(ti))
1408 * Even though the device advertised support for this type of
1409 * request, that does not mean every target supports it, and
1410 * reconfiguration might also have changed that since the
1411 * check was performed.
1413 num_bios = get_num_bios ? get_num_bios(ti) : 0;
1417 if (is_split_required && !is_split_required(ti))
1418 len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
1420 len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
1422 __send_duplicate_bios(ci, ti, num_bios, &len);
1425 } while (ci->sector_count -= len);
1430 static int __send_discard(struct clone_info *ci)
1432 return __send_changing_extent_only(ci, get_num_discard_bios,
1433 is_split_required_for_discard);
1436 static int __send_write_same(struct clone_info *ci)
1438 return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
1441 static int __send_write_zeroes(struct clone_info *ci)
1443 return __send_changing_extent_only(ci, get_num_write_zeroes_bios, NULL);
1447 * Select the correct strategy for processing a non-flush bio.
1449 static int __split_and_process_non_flush(struct clone_info *ci)
1451 struct bio *bio = ci->bio;
1452 struct dm_target *ti;
1456 if (unlikely(bio_op(bio) == REQ_OP_DISCARD))
1457 return __send_discard(ci);
1458 else if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))
1459 return __send_write_same(ci);
1460 else if (unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES))
1461 return __send_write_zeroes(ci);
1463 ti = dm_table_find_target(ci->map, ci->sector);
1464 if (!dm_target_is_valid(ti))
1467 if (bio_op(bio) == REQ_OP_ZONE_REPORT)
1468 len = ci->sector_count;
1470 len = min_t(sector_t, max_io_len(ci->sector, ti),
1473 r = __clone_and_map_data_bio(ci, ti, ci->sector, &len);
1478 ci->sector_count -= len;
1484 * Entry point to split a bio into clones and submit them to the targets.
1486 static void __split_and_process_bio(struct mapped_device *md,
1487 struct dm_table *map, struct bio *bio)
1489 struct clone_info ci;
1492 if (unlikely(!map)) {
1499 ci.io = alloc_io(md);
1501 atomic_set(&ci.io->io_count, 1);
1504 spin_lock_init(&ci.io->endio_lock);
1505 ci.sector = bio->bi_iter.bi_sector;
1507 start_io_acct(ci.io);
1509 if (bio->bi_opf & REQ_PREFLUSH) {
1510 ci.bio = &ci.md->flush_bio;
1511 ci.sector_count = 0;
1512 error = __send_empty_flush(&ci);
1513 /* dec_pending submits any data associated with flush */
1514 } else if (bio_op(bio) == REQ_OP_ZONE_RESET) {
1516 ci.sector_count = 0;
1517 error = __split_and_process_non_flush(&ci);
1520 ci.sector_count = bio_sectors(bio);
1521 while (ci.sector_count && !error)
1522 error = __split_and_process_non_flush(&ci);
1525 /* drop the extra reference count */
1526 dec_pending(ci.io, error);
1528 /*-----------------------------------------------------------------
1530 *---------------------------------------------------------------*/
1533 * The request function that just remaps the bio built up by
1536 static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
1538 int rw = bio_data_dir(bio);
1539 struct mapped_device *md = q->queuedata;
1541 struct dm_table *map;
1543 map = dm_get_live_table(md, &srcu_idx);
1545 generic_start_io_acct(rw, bio_sectors(bio), &dm_disk(md)->part0);
1547 /* if we're suspended, we have to queue this io for later */
1548 if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
1549 dm_put_live_table(md, srcu_idx);
1551 if (!(bio->bi_opf & REQ_RAHEAD))
1555 return BLK_QC_T_NONE;
1558 __split_and_process_bio(md, map, bio);
1559 dm_put_live_table(md, srcu_idx);
1560 return BLK_QC_T_NONE;
1563 static int dm_any_congested(void *congested_data, int bdi_bits)
1566 struct mapped_device *md = congested_data;
1567 struct dm_table *map;
1569 if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
1570 if (dm_request_based(md)) {
1572 * With request-based DM we only need to check the
1573 * top-level queue for congestion.
1575 r = md->queue->backing_dev_info->wb.state & bdi_bits;
1577 map = dm_get_live_table_fast(md);
1579 r = dm_table_any_congested(map, bdi_bits);
1580 dm_put_live_table_fast(md);
1587 /*-----------------------------------------------------------------
1588 * An IDR is used to keep track of allocated minor numbers.
1589 *---------------------------------------------------------------*/
1590 static void free_minor(int minor)
1592 spin_lock(&_minor_lock);
1593 idr_remove(&_minor_idr, minor);
1594 spin_unlock(&_minor_lock);
1598 * See if the device with a specific minor # is free.
1600 static int specific_minor(int minor)
1604 if (minor >= (1 << MINORBITS))
1607 idr_preload(GFP_KERNEL);
1608 spin_lock(&_minor_lock);
1610 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
1612 spin_unlock(&_minor_lock);
1615 return r == -ENOSPC ? -EBUSY : r;
1619 static int next_free_minor(int *minor)
1623 idr_preload(GFP_KERNEL);
1624 spin_lock(&_minor_lock);
1626 r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
1628 spin_unlock(&_minor_lock);
1636 static const struct block_device_operations dm_blk_dops;
1637 static const struct dax_operations dm_dax_ops;
1639 static void dm_wq_work(struct work_struct *work);
1641 void dm_init_md_queue(struct mapped_device *md)
1644 * Request-based dm devices cannot be stacked on top of bio-based dm
1645 * devices. The type of this dm device may not have been decided yet.
1646 * The type is decided at the first table loading time.
1647 * To prevent problematic device stacking, clear the queue flag
1648 * for request stacking support until then.
1650 * This queue is new, so no concurrency on the queue_flags.
1652 queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
1655 * Initialize data that will only be used by a non-blk-mq DM queue
1656 * - must do so here (in alloc_dev callchain) before queue is used
1658 md->queue->queuedata = md;
1659 md->queue->backing_dev_info->congested_data = md;
1662 void dm_init_normal_md_queue(struct mapped_device *md)
1664 md->use_blk_mq = false;
1665 dm_init_md_queue(md);
1668 * Initialize aspects of queue that aren't relevant for blk-mq
1670 md->queue->backing_dev_info->congested_fn = dm_any_congested;
1673 static void cleanup_mapped_device(struct mapped_device *md)
1676 destroy_workqueue(md->wq);
1677 if (md->kworker_task)
1678 kthread_stop(md->kworker_task);
1679 mempool_destroy(md->io_pool);
1681 bioset_free(md->bs);
1684 kill_dax(md->dax_dev);
1685 put_dax(md->dax_dev);
1690 spin_lock(&_minor_lock);
1691 md->disk->private_data = NULL;
1692 spin_unlock(&_minor_lock);
1693 del_gendisk(md->disk);
1698 blk_cleanup_queue(md->queue);
1700 cleanup_srcu_struct(&md->io_barrier);
1707 dm_mq_cleanup_mapped_device(md);
1711 * Allocate and initialise a blank device with a given minor.
1713 static struct mapped_device *alloc_dev(int minor)
1715 int r, numa_node_id = dm_get_numa_node();
1716 struct dax_device *dax_dev;
1717 struct mapped_device *md;
1720 md = kzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
1722 DMWARN("unable to allocate device, out of memory.");
1726 if (!try_module_get(THIS_MODULE))
1727 goto bad_module_get;
1729 /* get a minor number for the dev */
1730 if (minor == DM_ANY_MINOR)
1731 r = next_free_minor(&minor);
1733 r = specific_minor(minor);
1737 r = init_srcu_struct(&md->io_barrier);
1739 goto bad_io_barrier;
1741 md->numa_node_id = numa_node_id;
1742 md->use_blk_mq = dm_use_blk_mq_default();
1743 md->init_tio_pdu = false;
1744 md->type = DM_TYPE_NONE;
1745 mutex_init(&md->suspend_lock);
1746 mutex_init(&md->type_lock);
1747 mutex_init(&md->table_devices_lock);
1748 spin_lock_init(&md->deferred_lock);
1749 atomic_set(&md->holders, 1);
1750 atomic_set(&md->open_count, 0);
1751 atomic_set(&md->event_nr, 0);
1752 atomic_set(&md->uevent_seq, 0);
1753 INIT_LIST_HEAD(&md->uevent_list);
1754 INIT_LIST_HEAD(&md->table_devices);
1755 spin_lock_init(&md->uevent_lock);
1757 md->queue = blk_alloc_queue_node(GFP_KERNEL, numa_node_id);
1761 dm_init_md_queue(md);
1763 md->disk = alloc_disk_node(1, numa_node_id);
1767 atomic_set(&md->pending[0], 0);
1768 atomic_set(&md->pending[1], 0);
1769 init_waitqueue_head(&md->wait);
1770 INIT_WORK(&md->work, dm_wq_work);
1771 init_waitqueue_head(&md->eventq);
1772 init_completion(&md->kobj_holder.completion);
1773 md->kworker_task = NULL;
1775 md->disk->major = _major;
1776 md->disk->first_minor = minor;
1777 md->disk->fops = &dm_blk_dops;
1778 md->disk->queue = md->queue;
1779 md->disk->private_data = md;
1780 sprintf(md->disk->disk_name, "dm-%d", minor);
1782 dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops);
1785 md->dax_dev = dax_dev;
1788 format_dev_t(md->name, MKDEV(_major, minor));
1790 md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
1794 md->bdev = bdget_disk(md->disk, 0);
1798 bio_init(&md->flush_bio, NULL, 0);
1799 md->flush_bio.bi_bdev = md->bdev;
1800 md->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
1802 dm_stats_init(&md->stats);
1804 /* Populate the mapping, nobody knows we exist yet */
1805 spin_lock(&_minor_lock);
1806 old_md = idr_replace(&_minor_idr, md, minor);
1807 spin_unlock(&_minor_lock);
1809 BUG_ON(old_md != MINOR_ALLOCED);
1814 cleanup_mapped_device(md);
1818 module_put(THIS_MODULE);
1824 static void unlock_fs(struct mapped_device *md);
1826 static void free_dev(struct mapped_device *md)
1828 int minor = MINOR(disk_devt(md->disk));
1832 cleanup_mapped_device(md);
1834 free_table_devices(&md->table_devices);
1835 dm_stats_cleanup(&md->stats);
1838 module_put(THIS_MODULE);
1842 static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
1844 struct dm_md_mempools *p = dm_table_get_md_mempools(t);
1847 /* The md already has necessary mempools. */
1848 if (dm_table_bio_based(t)) {
1850 * Reload bioset because front_pad may have changed
1851 * because a different table was loaded.
1853 bioset_free(md->bs);
1858 * There's no need to reload with request-based dm
1859 * because the size of front_pad doesn't change.
1860 * Note for future: If you are to reload bioset,
1861 * prep-ed requests in the queue may refer
1862 * to bio from the old bioset, so you must walk
1863 * through the queue to unprep.
1868 BUG_ON(!p || md->io_pool || md->bs);
1870 md->io_pool = p->io_pool;
1876 /* mempool bind completed, no longer need any mempools in the table */
1877 dm_table_free_md_mempools(t);
1881 * Bind a table to the device.
1883 static void event_callback(void *context)
1885 unsigned long flags;
1887 struct mapped_device *md = (struct mapped_device *) context;
1889 spin_lock_irqsave(&md->uevent_lock, flags);
1890 list_splice_init(&md->uevent_list, &uevents);
1891 spin_unlock_irqrestore(&md->uevent_lock, flags);
1893 dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
1895 atomic_inc(&md->event_nr);
1896 atomic_inc(&dm_global_event_nr);
1897 wake_up(&md->eventq);
1898 wake_up(&dm_global_eventq);
1902 * Protected by md->suspend_lock obtained by dm_swap_table().
1904 static void __set_size(struct mapped_device *md, sector_t size)
1906 lockdep_assert_held(&md->suspend_lock);
1908 set_capacity(md->disk, size);
1910 i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
1914 * Returns old map, which caller must destroy.
1916 static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
1917 struct queue_limits *limits)
1919 struct dm_table *old_map;
1920 struct request_queue *q = md->queue;
1923 lockdep_assert_held(&md->suspend_lock);
1925 size = dm_table_get_size(t);
1928 * Wipe any geometry if the size of the table changed.
1930 if (size != dm_get_size(md))
1931 memset(&md->geometry, 0, sizeof(md->geometry));
1933 __set_size(md, size);
1935 dm_table_event_callback(t, event_callback, md);
1938 * The queue hasn't been stopped yet, if the old table type wasn't
1939 * for request-based during suspension. So stop it to prevent
1940 * I/O mapping before resume.
1941 * This must be done before setting the queue restrictions,
1942 * because request-based dm may be run just after the setting.
1944 if (dm_table_request_based(t)) {
1947 * Leverage the fact that request-based DM targets are
1948 * immutable singletons and establish md->immutable_target
1949 * - used to optimize both dm_request_fn and dm_mq_queue_rq
1951 md->immutable_target = dm_table_get_immutable_target(t);
1954 __bind_mempools(md, t);
1956 old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
1957 rcu_assign_pointer(md->map, (void *)t);
1958 md->immutable_target_type = dm_table_get_immutable_target_type(t);
1960 dm_table_set_restrictions(t, q, limits);
1968 * Returns unbound table for the caller to free.
1970 static struct dm_table *__unbind(struct mapped_device *md)
1972 struct dm_table *map = rcu_dereference_protected(md->map, 1);
1977 dm_table_event_callback(map, NULL, NULL);
1978 RCU_INIT_POINTER(md->map, NULL);
1985 * Constructor for a new device.
1987 int dm_create(int minor, struct mapped_device **result)
1989 struct mapped_device *md;
1991 md = alloc_dev(minor);
2002 * Functions to manage md->type.
2003 * All are required to hold md->type_lock.
2005 void dm_lock_md_type(struct mapped_device *md)
2007 mutex_lock(&md->type_lock);
2010 void dm_unlock_md_type(struct mapped_device *md)
2012 mutex_unlock(&md->type_lock);
2015 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type)
2017 BUG_ON(!mutex_is_locked(&md->type_lock));
2021 enum dm_queue_mode dm_get_md_type(struct mapped_device *md)
2026 struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
2028 return md->immutable_target_type;
2032 * The queue_limits are only valid as long as you have a reference
2035 struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
2037 BUG_ON(!atomic_read(&md->holders));
2038 return &md->queue->limits;
2040 EXPORT_SYMBOL_GPL(dm_get_queue_limits);
2043 * Setup the DM device's queue based on md's type
2045 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
2048 enum dm_queue_mode type = dm_get_md_type(md);
2051 case DM_TYPE_REQUEST_BASED:
2052 r = dm_old_init_request_queue(md, t);
2054 DMERR("Cannot initialize queue for request-based mapped device");
2058 case DM_TYPE_MQ_REQUEST_BASED:
2059 r = dm_mq_init_request_queue(md, t);
2061 DMERR("Cannot initialize queue for request-based dm-mq mapped device");
2065 case DM_TYPE_BIO_BASED:
2066 case DM_TYPE_DAX_BIO_BASED:
2067 dm_init_normal_md_queue(md);
2068 blk_queue_make_request(md->queue, dm_make_request);
2070 * DM handles splitting bios as needed. Free the bio_split bioset
2071 * since it won't be used (saves 1 process per bio-based DM device).
2073 bioset_free(md->queue->bio_split);
2074 md->queue->bio_split = NULL;
2076 if (type == DM_TYPE_DAX_BIO_BASED)
2077 queue_flag_set_unlocked(QUEUE_FLAG_DAX, md->queue);
2087 struct mapped_device *dm_get_md(dev_t dev)
2089 struct mapped_device *md;
2090 unsigned minor = MINOR(dev);
2092 if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
2095 spin_lock(&_minor_lock);
2097 md = idr_find(&_minor_idr, minor);
2099 if ((md == MINOR_ALLOCED ||
2100 (MINOR(disk_devt(dm_disk(md))) != minor) ||
2101 dm_deleting_md(md) ||
2102 test_bit(DMF_FREEING, &md->flags))) {
2110 spin_unlock(&_minor_lock);
2114 EXPORT_SYMBOL_GPL(dm_get_md);
2116 void *dm_get_mdptr(struct mapped_device *md)
2118 return md->interface_ptr;
2121 void dm_set_mdptr(struct mapped_device *md, void *ptr)
2123 md->interface_ptr = ptr;
2126 void dm_get(struct mapped_device *md)
2128 atomic_inc(&md->holders);
2129 BUG_ON(test_bit(DMF_FREEING, &md->flags));
2132 int dm_hold(struct mapped_device *md)
2134 spin_lock(&_minor_lock);
2135 if (test_bit(DMF_FREEING, &md->flags)) {
2136 spin_unlock(&_minor_lock);
2140 spin_unlock(&_minor_lock);
2143 EXPORT_SYMBOL_GPL(dm_hold);
2145 const char *dm_device_name(struct mapped_device *md)
2149 EXPORT_SYMBOL_GPL(dm_device_name);
2151 static void __dm_destroy(struct mapped_device *md, bool wait)
2153 struct request_queue *q = dm_get_md_queue(md);
2154 struct dm_table *map;
2159 spin_lock(&_minor_lock);
2160 idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
2161 set_bit(DMF_FREEING, &md->flags);
2162 spin_unlock(&_minor_lock);
2164 blk_set_queue_dying(q);
2166 if (dm_request_based(md) && md->kworker_task)
2167 kthread_flush_worker(&md->kworker);
2170 * Take suspend_lock so that presuspend and postsuspend methods
2171 * do not race with internal suspend.
2173 mutex_lock(&md->suspend_lock);
2174 map = dm_get_live_table(md, &srcu_idx);
2175 if (!dm_suspended_md(md)) {
2176 dm_table_presuspend_targets(map);
2177 dm_table_postsuspend_targets(map);
2179 /* dm_put_live_table must be before msleep, otherwise deadlock is possible */
2180 dm_put_live_table(md, srcu_idx);
2181 mutex_unlock(&md->suspend_lock);
2184 * Rare, but there may be I/O requests still going to complete,
2185 * for example. Wait for all references to disappear.
2186 * No one should increment the reference count of the mapped_device,
2187 * after the mapped_device state becomes DMF_FREEING.
2190 while (atomic_read(&md->holders))
2192 else if (atomic_read(&md->holders))
2193 DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
2194 dm_device_name(md), atomic_read(&md->holders));
2197 dm_table_destroy(__unbind(md));
2201 void dm_destroy(struct mapped_device *md)
2203 __dm_destroy(md, true);
2206 void dm_destroy_immediate(struct mapped_device *md)
2208 __dm_destroy(md, false);
2211 void dm_put(struct mapped_device *md)
2213 atomic_dec(&md->holders);
2215 EXPORT_SYMBOL_GPL(dm_put);
2217 static int dm_wait_for_completion(struct mapped_device *md, long task_state)
2223 prepare_to_wait(&md->wait, &wait, task_state);
2225 if (!md_in_flight(md))
2228 if (signal_pending_state(task_state, current)) {
2235 finish_wait(&md->wait, &wait);
2241 * Process the deferred bios
2243 static void dm_wq_work(struct work_struct *work)
2245 struct mapped_device *md = container_of(work, struct mapped_device,
2249 struct dm_table *map;
2251 map = dm_get_live_table(md, &srcu_idx);
2253 while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
2254 spin_lock_irq(&md->deferred_lock);
2255 c = bio_list_pop(&md->deferred);
2256 spin_unlock_irq(&md->deferred_lock);
2261 if (dm_request_based(md))
2262 generic_make_request(c);
2264 __split_and_process_bio(md, map, c);
2267 dm_put_live_table(md, srcu_idx);
2270 static void dm_queue_flush(struct mapped_device *md)
2272 clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2273 smp_mb__after_atomic();
2274 queue_work(md->wq, &md->work);
2278 * Swap in a new table, returning the old one for the caller to destroy.
2280 struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
2282 struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
2283 struct queue_limits limits;
2286 mutex_lock(&md->suspend_lock);
2288 /* device must be suspended */
2289 if (!dm_suspended_md(md))
2293 * If the new table has no data devices, retain the existing limits.
2294 * This helps multipath with queue_if_no_path if all paths disappear,
2295 * then new I/O is queued based on these limits, and then some paths
2298 if (dm_table_has_no_data_devices(table)) {
2299 live_map = dm_get_live_table_fast(md);
2301 limits = md->queue->limits;
2302 dm_put_live_table_fast(md);
2306 r = dm_calculate_queue_limits(table, &limits);
2313 map = __bind(md, table, &limits);
2316 mutex_unlock(&md->suspend_lock);
2321 * Functions to lock and unlock any filesystem running on the
2324 static int lock_fs(struct mapped_device *md)
2328 WARN_ON(md->frozen_sb);
2330 md->frozen_sb = freeze_bdev(md->bdev);
2331 if (IS_ERR(md->frozen_sb)) {
2332 r = PTR_ERR(md->frozen_sb);
2333 md->frozen_sb = NULL;
2337 set_bit(DMF_FROZEN, &md->flags);
2342 static void unlock_fs(struct mapped_device *md)
2344 if (!test_bit(DMF_FROZEN, &md->flags))
2347 thaw_bdev(md->bdev, md->frozen_sb);
2348 md->frozen_sb = NULL;
2349 clear_bit(DMF_FROZEN, &md->flags);
2353 * @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG
2354 * @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE
2355 * @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY
2357 * If __dm_suspend returns 0, the device is completely quiescent
2358 * now. There is no request-processing activity. All new requests
2359 * are being added to md->deferred list.
2361 static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
2362 unsigned suspend_flags, long task_state,
2363 int dmf_suspended_flag)
2365 bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
2366 bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
2369 lockdep_assert_held(&md->suspend_lock);
2372 * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
2373 * This flag is cleared before dm_suspend returns.
2376 set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2378 pr_debug("%s: suspending with flush\n", dm_device_name(md));
2381 * This gets reverted if there's an error later and the targets
2382 * provide the .presuspend_undo hook.
2384 dm_table_presuspend_targets(map);
2387 * Flush I/O to the device.
2388 * Any I/O submitted after lock_fs() may not be flushed.
2389 * noflush takes precedence over do_lockfs.
2390 * (lock_fs() flushes I/Os and waits for them to complete.)
2392 if (!noflush && do_lockfs) {
2395 dm_table_presuspend_undo_targets(map);
2401 * Here we must make sure that no processes are submitting requests
2402 * to target drivers i.e. no one may be executing
2403 * __split_and_process_bio. This is called from dm_request and
2406 * To get all processes out of __split_and_process_bio in dm_request,
2407 * we take the write lock. To prevent any process from reentering
2408 * __split_and_process_bio from dm_request and quiesce the thread
2409 * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
2410 * flush_workqueue(md->wq).
2412 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2414 synchronize_srcu(&md->io_barrier);
2417 * Stop md->queue before flushing md->wq in case request-based
2418 * dm defers requests to md->wq from md->queue.
2420 if (dm_request_based(md)) {
2421 dm_stop_queue(md->queue);
2422 if (md->kworker_task)
2423 kthread_flush_worker(&md->kworker);
2426 flush_workqueue(md->wq);
2429 * At this point no more requests are entering target request routines.
2430 * We call dm_wait_for_completion to wait for all existing requests
2433 r = dm_wait_for_completion(md, task_state);
2435 set_bit(dmf_suspended_flag, &md->flags);
2438 clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
2440 synchronize_srcu(&md->io_barrier);
2442 /* were we interrupted ? */
2446 if (dm_request_based(md))
2447 dm_start_queue(md->queue);
2450 dm_table_presuspend_undo_targets(map);
2451 /* pushback list is already flushed, so skip flush */
2458 * We need to be able to change a mapping table under a mounted
2459 * filesystem. For example we might want to move some data in
2460 * the background. Before the table can be swapped with
2461 * dm_bind_table, dm_suspend must be called to flush any in
2462 * flight bios and ensure that any further io gets deferred.
2465 * Suspend mechanism in request-based dm.
2467 * 1. Flush all I/Os by lock_fs() if needed.
2468 * 2. Stop dispatching any I/O by stopping the request_queue.
2469 * 3. Wait for all in-flight I/Os to be completed or requeued.
2471 * To abort suspend, start the request_queue.
2473 int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
2475 struct dm_table *map = NULL;
2479 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2481 if (dm_suspended_md(md)) {
2486 if (dm_suspended_internally_md(md)) {
2487 /* already internally suspended, wait for internal resume */
2488 mutex_unlock(&md->suspend_lock);
2489 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2495 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2497 r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);
2501 dm_table_postsuspend_targets(map);
2504 mutex_unlock(&md->suspend_lock);
2508 static int __dm_resume(struct mapped_device *md, struct dm_table *map)
2511 int r = dm_table_resume_targets(map);
2519 * Flushing deferred I/Os must be done after targets are resumed
2520 * so that mapping of targets can work correctly.
2521 * Request-based dm is queueing the deferred I/Os in its request_queue.
2523 if (dm_request_based(md))
2524 dm_start_queue(md->queue);
2531 int dm_resume(struct mapped_device *md)
2534 struct dm_table *map = NULL;
2538 mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
2540 if (!dm_suspended_md(md))
2543 if (dm_suspended_internally_md(md)) {
2544 /* already internally suspended, wait for internal resume */
2545 mutex_unlock(&md->suspend_lock);
2546 r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
2552 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2553 if (!map || !dm_table_get_size(map))
2556 r = __dm_resume(md, map);
2560 clear_bit(DMF_SUSPENDED, &md->flags);
2562 mutex_unlock(&md->suspend_lock);
2568 * Internal suspend/resume works like userspace-driven suspend. It waits
2569 * until all bios finish and prevents issuing new bios to the target drivers.
2570 * It may be used only from the kernel.
2573 static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
2575 struct dm_table *map = NULL;
2577 lockdep_assert_held(&md->suspend_lock);
2579 if (md->internal_suspend_count++)
2580 return; /* nested internal suspend */
2582 if (dm_suspended_md(md)) {
2583 set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2584 return; /* nest suspend */
2587 map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
2590 * Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
2591 * supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
2592 * would require changing .presuspend to return an error -- avoid this
2593 * until there is a need for more elaborate variants of internal suspend.
2595 (void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
2596 DMF_SUSPENDED_INTERNALLY);
2598 dm_table_postsuspend_targets(map);
2601 static void __dm_internal_resume(struct mapped_device *md)
2603 BUG_ON(!md->internal_suspend_count);
2605 if (--md->internal_suspend_count)
2606 return; /* resume from nested internal suspend */
2608 if (dm_suspended_md(md))
2609 goto done; /* resume from nested suspend */
2612 * NOTE: existing callers don't need to call dm_table_resume_targets
2613 * (which may fail -- so best to avoid it for now by passing NULL map)
2615 (void) __dm_resume(md, NULL);
2618 clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2619 smp_mb__after_atomic();
2620 wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
2623 void dm_internal_suspend_noflush(struct mapped_device *md)
2625 mutex_lock(&md->suspend_lock);
2626 __dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
2627 mutex_unlock(&md->suspend_lock);
2629 EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
2631 void dm_internal_resume(struct mapped_device *md)
2633 mutex_lock(&md->suspend_lock);
2634 __dm_internal_resume(md);
2635 mutex_unlock(&md->suspend_lock);
2637 EXPORT_SYMBOL_GPL(dm_internal_resume);
2640 * Fast variants of internal suspend/resume hold md->suspend_lock,
2641 * which prevents interaction with userspace-driven suspend.
2644 void dm_internal_suspend_fast(struct mapped_device *md)
2646 mutex_lock(&md->suspend_lock);
2647 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2650 set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
2651 synchronize_srcu(&md->io_barrier);
2652 flush_workqueue(md->wq);
2653 dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
2655 EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
2657 void dm_internal_resume_fast(struct mapped_device *md)
2659 if (dm_suspended_md(md) || dm_suspended_internally_md(md))
2665 mutex_unlock(&md->suspend_lock);
2667 EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
2669 /*-----------------------------------------------------------------
2670 * Event notification.
2671 *---------------------------------------------------------------*/
2672 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
2675 char udev_cookie[DM_COOKIE_LENGTH];
2676 char *envp[] = { udev_cookie, NULL };
2679 return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
2681 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
2682 DM_COOKIE_ENV_VAR_NAME, cookie);
2683 return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
2688 uint32_t dm_next_uevent_seq(struct mapped_device *md)
2690 return atomic_add_return(1, &md->uevent_seq);
2693 uint32_t dm_get_event_nr(struct mapped_device *md)
2695 return atomic_read(&md->event_nr);
2698 int dm_wait_event(struct mapped_device *md, int event_nr)
2700 return wait_event_interruptible(md->eventq,
2701 (event_nr != atomic_read(&md->event_nr)));
2704 void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
2706 unsigned long flags;
2708 spin_lock_irqsave(&md->uevent_lock, flags);
2709 list_add(elist, &md->uevent_list);
2710 spin_unlock_irqrestore(&md->uevent_lock, flags);
2714 * The gendisk is only valid as long as you have a reference
2717 struct gendisk *dm_disk(struct mapped_device *md)
2721 EXPORT_SYMBOL_GPL(dm_disk);
2723 struct kobject *dm_kobject(struct mapped_device *md)
2725 return &md->kobj_holder.kobj;
2728 struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
2730 struct mapped_device *md;
2732 md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
2734 if (test_bit(DMF_FREEING, &md->flags) ||
2742 int dm_suspended_md(struct mapped_device *md)
2744 return test_bit(DMF_SUSPENDED, &md->flags);
2747 int dm_suspended_internally_md(struct mapped_device *md)
2749 return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
2752 int dm_test_deferred_remove_flag(struct mapped_device *md)
2754 return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
2757 int dm_suspended(struct dm_target *ti)
2759 return dm_suspended_md(dm_table_get_md(ti->table));
2761 EXPORT_SYMBOL_GPL(dm_suspended);
2763 int dm_noflush_suspending(struct dm_target *ti)
2765 return __noflush_suspending(dm_table_get_md(ti->table));
2767 EXPORT_SYMBOL_GPL(dm_noflush_suspending);
2769 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
2770 unsigned integrity, unsigned per_io_data_size)
2772 struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
2773 unsigned int pool_size = 0;
2774 unsigned int front_pad;
2780 case DM_TYPE_BIO_BASED:
2781 case DM_TYPE_DAX_BIO_BASED:
2782 pool_size = dm_get_reserved_bio_based_ios();
2783 front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
2785 pools->io_pool = mempool_create_slab_pool(pool_size, _io_cache);
2786 if (!pools->io_pool)
2789 case DM_TYPE_REQUEST_BASED:
2790 case DM_TYPE_MQ_REQUEST_BASED:
2791 pool_size = dm_get_reserved_rq_based_ios();
2792 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
2793 /* per_io_data_size is used for blk-mq pdu at queue allocation */
2799 pools->bs = bioset_create(pool_size, front_pad, BIOSET_NEED_RESCUER);
2803 if (integrity && bioset_integrity_create(pools->bs, pool_size))
2809 dm_free_md_mempools(pools);
2814 void dm_free_md_mempools(struct dm_md_mempools *pools)
2819 mempool_destroy(pools->io_pool);
2822 bioset_free(pools->bs);
2834 static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
2837 struct mapped_device *md = bdev->bd_disk->private_data;
2838 struct dm_table *table;
2839 struct dm_target *ti;
2840 int ret = -ENOTTY, srcu_idx;
2842 table = dm_get_live_table(md, &srcu_idx);
2843 if (!table || !dm_table_get_size(table))
2846 /* We only support devices that have a single target */
2847 if (dm_table_get_num_targets(table) != 1)
2849 ti = dm_table_get_target(table, 0);
2852 if (!ti->type->iterate_devices)
2855 ret = ti->type->iterate_devices(ti, fn, data);
2857 dm_put_live_table(md, srcu_idx);
2862 * For register / unregister we need to manually call out to every path.
2864 static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev,
2865 sector_t start, sector_t len, void *data)
2867 struct dm_pr *pr = data;
2868 const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
2870 if (!ops || !ops->pr_register)
2872 return ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
2875 static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
2886 ret = dm_call_pr(bdev, __dm_pr_register, &pr);
2887 if (ret && new_key) {
2888 /* unregister all paths if we failed to register any path */
2889 pr.old_key = new_key;
2892 pr.fail_early = false;
2893 dm_call_pr(bdev, __dm_pr_register, &pr);
2899 static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
2902 struct mapped_device *md = bdev->bd_disk->private_data;
2903 const struct pr_ops *ops;
2907 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
2911 ops = bdev->bd_disk->fops->pr_ops;
2912 if (ops && ops->pr_reserve)
2913 r = ops->pr_reserve(bdev, key, type, flags);
2921 static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
2923 struct mapped_device *md = bdev->bd_disk->private_data;
2924 const struct pr_ops *ops;
2928 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
2932 ops = bdev->bd_disk->fops->pr_ops;
2933 if (ops && ops->pr_release)
2934 r = ops->pr_release(bdev, key, type);
2942 static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
2943 enum pr_type type, bool abort)
2945 struct mapped_device *md = bdev->bd_disk->private_data;
2946 const struct pr_ops *ops;
2950 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
2954 ops = bdev->bd_disk->fops->pr_ops;
2955 if (ops && ops->pr_preempt)
2956 r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
2964 static int dm_pr_clear(struct block_device *bdev, u64 key)
2966 struct mapped_device *md = bdev->bd_disk->private_data;
2967 const struct pr_ops *ops;
2971 r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
2975 ops = bdev->bd_disk->fops->pr_ops;
2976 if (ops && ops->pr_clear)
2977 r = ops->pr_clear(bdev, key);
2985 static const struct pr_ops dm_pr_ops = {
2986 .pr_register = dm_pr_register,
2987 .pr_reserve = dm_pr_reserve,
2988 .pr_release = dm_pr_release,
2989 .pr_preempt = dm_pr_preempt,
2990 .pr_clear = dm_pr_clear,
2993 static const struct block_device_operations dm_blk_dops = {
2994 .open = dm_blk_open,
2995 .release = dm_blk_close,
2996 .ioctl = dm_blk_ioctl,
2997 .getgeo = dm_blk_getgeo,
2998 .pr_ops = &dm_pr_ops,
2999 .owner = THIS_MODULE
3002 static const struct dax_operations dm_dax_ops = {
3003 .direct_access = dm_dax_direct_access,
3004 .copy_from_iter = dm_dax_copy_from_iter,
3005 .flush = dm_dax_flush,
3011 module_init(dm_init);
3012 module_exit(dm_exit);
3014 module_param(major, uint, 0);
3015 MODULE_PARM_DESC(major, "The major number of the device mapper");
3017 module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
3018 MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
3020 module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
3021 MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
3023 MODULE_DESCRIPTION(DM_NAME " driver");
3024 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3025 MODULE_LICENSE("GPL");