1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2011-2012 Red Hat UK.
5 * This file is released under the GPL.
8 #include "dm-thin-metadata.h"
9 #include "dm-bio-prison-v1.h"
12 #include <linux/device-mapper.h>
13 #include <linux/dm-io.h>
14 #include <linux/dm-kcopyd.h>
15 #include <linux/jiffies.h>
16 #include <linux/log2.h>
17 #include <linux/list.h>
18 #include <linux/rculist.h>
19 #include <linux/init.h>
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 #include <linux/vmalloc.h>
23 #include <linux/sort.h>
24 #include <linux/rbtree.h>
26 #define DM_MSG_PREFIX "thin"
31 #define ENDIO_HOOK_POOL_SIZE 1024
32 #define MAPPING_POOL_SIZE 1024
33 #define COMMIT_PERIOD HZ
34 #define NO_SPACE_TIMEOUT_SECS 60
36 static unsigned int no_space_timeout_secs = NO_SPACE_TIMEOUT_SECS;
38 DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle,
39 "A percentage of time allocated for copy on write");
42 * The block size of the device holding pool data must be
43 * between 64KB and 1GB.
45 #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
46 #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
49 * Device id is restricted to 24 bits.
51 #define MAX_DEV_ID ((1 << 24) - 1)
54 * How do we handle breaking sharing of data blocks?
55 * =================================================
57 * We use a standard copy-on-write btree to store the mappings for the
58 * devices (note I'm talking about copy-on-write of the metadata here, not
59 * the data). When you take an internal snapshot you clone the root node
60 * of the origin btree. After this there is no concept of an origin or a
61 * snapshot. They are just two device trees that happen to point to the
64 * When we get a write in we decide if it's to a shared data block using
65 * some timestamp magic. If it is, we have to break sharing.
67 * Let's say we write to a shared block in what was the origin. The
70 * i) plug io further to this physical block. (see bio_prison code).
72 * ii) quiesce any read io to that shared data block. Obviously
73 * including all devices that share this block. (see dm_deferred_set code)
75 * iii) copy the data block to a newly allocate block. This step can be
76 * missed out if the io covers the block. (schedule_copy).
78 * iv) insert the new mapping into the origin's btree
79 * (process_prepared_mapping). This act of inserting breaks some
80 * sharing of btree nodes between the two devices. Breaking sharing only
81 * effects the btree of that specific device. Btrees for the other
82 * devices that share the block never change. The btree for the origin
83 * device as it was after the last commit is untouched, ie. we're using
84 * persistent data structures in the functional programming sense.
86 * v) unplug io to this physical block, including the io that triggered
87 * the breaking of sharing.
89 * Steps (ii) and (iii) occur in parallel.
91 * The metadata _doesn't_ need to be committed before the io continues. We
92 * get away with this because the io is always written to a _new_ block.
93 * If there's a crash, then:
95 * - The origin mapping will point to the old origin block (the shared
96 * one). This will contain the data as it was before the io that triggered
97 * the breaking of sharing came in.
99 * - The snap mapping still points to the old block. As it would after
102 * The downside of this scheme is the timestamp magic isn't perfect, and
103 * will continue to think that data block in the snapshot device is shared
104 * even after the write to the origin has broken sharing. I suspect data
105 * blocks will typically be shared by many different devices, so we're
106 * breaking sharing n + 1 times, rather than n, where n is the number of
107 * devices that reference this data block. At the moment I think the
108 * benefits far, far outweigh the disadvantages.
111 /*----------------------------------------------------------------*/
121 static bool build_key(struct dm_thin_device *td, enum lock_space ls,
122 dm_block_t b, dm_block_t e, struct dm_cell_key *key)
124 key->virtual = (ls == VIRTUAL);
125 key->dev = dm_thin_dev_id(td);
126 key->block_begin = b;
129 return dm_cell_key_has_valid_range(key);
132 static void build_data_key(struct dm_thin_device *td, dm_block_t b,
133 struct dm_cell_key *key)
135 (void) build_key(td, PHYSICAL, b, b + 1llu, key);
138 static void build_virtual_key(struct dm_thin_device *td, dm_block_t b,
139 struct dm_cell_key *key)
141 (void) build_key(td, VIRTUAL, b, b + 1llu, key);
144 /*----------------------------------------------------------------*/
146 #define THROTTLE_THRESHOLD (1 * HZ)
149 struct rw_semaphore lock;
150 unsigned long threshold;
151 bool throttle_applied;
154 static void throttle_init(struct throttle *t)
156 init_rwsem(&t->lock);
157 t->throttle_applied = false;
160 static void throttle_work_start(struct throttle *t)
162 t->threshold = jiffies + THROTTLE_THRESHOLD;
165 static void throttle_work_update(struct throttle *t)
167 if (!t->throttle_applied && time_is_before_jiffies(t->threshold)) {
168 down_write(&t->lock);
169 t->throttle_applied = true;
173 static void throttle_work_complete(struct throttle *t)
175 if (t->throttle_applied) {
176 t->throttle_applied = false;
181 static void throttle_lock(struct throttle *t)
186 static void throttle_unlock(struct throttle *t)
191 /*----------------------------------------------------------------*/
194 * A pool device ties together a metadata device and a data device. It
195 * also provides the interface for creating and destroying internal
198 struct dm_thin_new_mapping;
201 * The pool runs in various modes. Ordered in degraded order for comparisons.
204 PM_WRITE, /* metadata may be changed */
205 PM_OUT_OF_DATA_SPACE, /* metadata may be changed, though data may not be allocated */
208 * Like READ_ONLY, except may switch back to WRITE on metadata resize. Reported as READ_ONLY.
210 PM_OUT_OF_METADATA_SPACE,
211 PM_READ_ONLY, /* metadata may not be changed */
213 PM_FAIL, /* all I/O fails */
216 struct pool_features {
219 bool zero_new_blocks:1;
220 bool discard_enabled:1;
221 bool discard_passdown:1;
222 bool error_if_no_space:1;
226 typedef void (*process_bio_fn)(struct thin_c *tc, struct bio *bio);
227 typedef void (*process_cell_fn)(struct thin_c *tc, struct dm_bio_prison_cell *cell);
228 typedef void (*process_mapping_fn)(struct dm_thin_new_mapping *m);
230 #define CELL_SORT_ARRAY_SIZE 8192
233 struct list_head list;
234 struct dm_target *ti; /* Only set if a pool target is bound */
236 struct mapped_device *pool_md;
237 struct block_device *data_dev;
238 struct block_device *md_dev;
239 struct dm_pool_metadata *pmd;
241 dm_block_t low_water_blocks;
242 uint32_t sectors_per_block;
243 int sectors_per_block_shift;
245 struct pool_features pf;
246 bool low_water_triggered:1; /* A dm event has been sent */
248 bool out_of_data_space:1;
250 struct dm_bio_prison *prison;
251 struct dm_kcopyd_client *copier;
253 struct work_struct worker;
254 struct workqueue_struct *wq;
255 struct throttle throttle;
256 struct delayed_work waker;
257 struct delayed_work no_space_timeout;
259 unsigned long last_commit_jiffies;
260 unsigned int ref_count;
263 struct bio_list deferred_flush_bios;
264 struct bio_list deferred_flush_completions;
265 struct list_head prepared_mappings;
266 struct list_head prepared_discards;
267 struct list_head prepared_discards_pt2;
268 struct list_head active_thins;
270 struct dm_deferred_set *shared_read_ds;
271 struct dm_deferred_set *all_io_ds;
273 struct dm_thin_new_mapping *next_mapping;
275 process_bio_fn process_bio;
276 process_bio_fn process_discard;
278 process_cell_fn process_cell;
279 process_cell_fn process_discard_cell;
281 process_mapping_fn process_prepared_mapping;
282 process_mapping_fn process_prepared_discard;
283 process_mapping_fn process_prepared_discard_pt2;
285 struct dm_bio_prison_cell **cell_sort_array;
287 mempool_t mapping_pool;
290 static void metadata_operation_failed(struct pool *pool, const char *op, int r);
292 static enum pool_mode get_pool_mode(struct pool *pool)
294 return pool->pf.mode;
297 static void notify_of_pool_mode_change(struct pool *pool)
299 static const char *descs[] = {
306 const char *extra_desc = NULL;
307 enum pool_mode mode = get_pool_mode(pool);
309 if (mode == PM_OUT_OF_DATA_SPACE) {
310 if (!pool->pf.error_if_no_space)
311 extra_desc = " (queue IO)";
313 extra_desc = " (error IO)";
316 dm_table_event(pool->ti->table);
317 DMINFO("%s: switching pool to %s%s mode",
318 dm_device_name(pool->pool_md),
319 descs[(int)mode], extra_desc ? : "");
323 * Target context for a pool.
326 struct dm_target *ti;
328 struct dm_dev *data_dev;
329 struct dm_dev *metadata_dev;
331 dm_block_t low_water_blocks;
332 struct pool_features requested_pf; /* Features requested during table load */
333 struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */
337 * Target context for a thin.
340 struct list_head list;
341 struct dm_dev *pool_dev;
342 struct dm_dev *origin_dev;
343 sector_t origin_size;
347 struct dm_thin_device *td;
348 struct mapped_device *thin_md;
352 struct list_head deferred_cells;
353 struct bio_list deferred_bio_list;
354 struct bio_list retry_on_resume_list;
355 struct rb_root sort_bio_list; /* sorted list of deferred bios */
358 * Ensures the thin is not destroyed until the worker has finished
359 * iterating the active_thins list.
362 struct completion can_destroy;
365 /*----------------------------------------------------------------*/
367 static bool block_size_is_power_of_two(struct pool *pool)
369 return pool->sectors_per_block_shift >= 0;
372 static sector_t block_to_sectors(struct pool *pool, dm_block_t b)
374 return block_size_is_power_of_two(pool) ?
375 (b << pool->sectors_per_block_shift) :
376 (b * pool->sectors_per_block);
379 /*----------------------------------------------------------------*/
383 struct blk_plug plug;
384 struct bio *parent_bio;
388 static void begin_discard(struct discard_op *op, struct thin_c *tc, struct bio *parent)
393 blk_start_plug(&op->plug);
394 op->parent_bio = parent;
398 static int issue_discard(struct discard_op *op, dm_block_t data_b, dm_block_t data_e)
400 struct thin_c *tc = op->tc;
401 sector_t s = block_to_sectors(tc->pool, data_b);
402 sector_t len = block_to_sectors(tc->pool, data_e - data_b);
404 return __blkdev_issue_discard(tc->pool_dev->bdev, s, len, GFP_NOIO, &op->bio);
407 static void end_discard(struct discard_op *op, int r)
411 * Even if one of the calls to issue_discard failed, we
412 * need to wait for the chain to complete.
414 bio_chain(op->bio, op->parent_bio);
415 op->bio->bi_opf = REQ_OP_DISCARD;
419 blk_finish_plug(&op->plug);
422 * Even if r is set, there could be sub discards in flight that we
425 if (r && !op->parent_bio->bi_status)
426 op->parent_bio->bi_status = errno_to_blk_status(r);
427 bio_endio(op->parent_bio);
430 /*----------------------------------------------------------------*/
433 * wake_worker() is used when new work is queued and when pool_resume is
434 * ready to continue deferred IO processing.
436 static void wake_worker(struct pool *pool)
438 queue_work(pool->wq, &pool->worker);
441 /*----------------------------------------------------------------*/
443 static int bio_detain(struct pool *pool, struct dm_cell_key *key, struct bio *bio,
444 struct dm_bio_prison_cell **cell_result)
447 struct dm_bio_prison_cell *cell_prealloc;
450 * Allocate a cell from the prison's mempool.
451 * This might block but it can't fail.
453 cell_prealloc = dm_bio_prison_alloc_cell(pool->prison, GFP_NOIO);
455 r = dm_bio_detain(pool->prison, key, bio, cell_prealloc, cell_result);
458 * We reused an old cell; we can get rid of
461 dm_bio_prison_free_cell(pool->prison, cell_prealloc);
467 static void cell_release(struct pool *pool,
468 struct dm_bio_prison_cell *cell,
469 struct bio_list *bios)
471 dm_cell_release(pool->prison, cell, bios);
472 dm_bio_prison_free_cell(pool->prison, cell);
475 static void cell_visit_release(struct pool *pool,
476 void (*fn)(void *, struct dm_bio_prison_cell *),
478 struct dm_bio_prison_cell *cell)
480 dm_cell_visit_release(pool->prison, fn, context, cell);
481 dm_bio_prison_free_cell(pool->prison, cell);
484 static void cell_release_no_holder(struct pool *pool,
485 struct dm_bio_prison_cell *cell,
486 struct bio_list *bios)
488 dm_cell_release_no_holder(pool->prison, cell, bios);
489 dm_bio_prison_free_cell(pool->prison, cell);
492 static void cell_error_with_code(struct pool *pool,
493 struct dm_bio_prison_cell *cell, blk_status_t error_code)
495 dm_cell_error(pool->prison, cell, error_code);
496 dm_bio_prison_free_cell(pool->prison, cell);
499 static blk_status_t get_pool_io_error_code(struct pool *pool)
501 return pool->out_of_data_space ? BLK_STS_NOSPC : BLK_STS_IOERR;
504 static void cell_error(struct pool *pool, struct dm_bio_prison_cell *cell)
506 cell_error_with_code(pool, cell, get_pool_io_error_code(pool));
509 static void cell_success(struct pool *pool, struct dm_bio_prison_cell *cell)
511 cell_error_with_code(pool, cell, 0);
514 static void cell_requeue(struct pool *pool, struct dm_bio_prison_cell *cell)
516 cell_error_with_code(pool, cell, BLK_STS_DM_REQUEUE);
519 /*----------------------------------------------------------------*/
522 * A global list of pools that uses a struct mapped_device as a key.
524 static struct dm_thin_pool_table {
526 struct list_head pools;
527 } dm_thin_pool_table;
529 static void pool_table_init(void)
531 mutex_init(&dm_thin_pool_table.mutex);
532 INIT_LIST_HEAD(&dm_thin_pool_table.pools);
535 static void pool_table_exit(void)
537 mutex_destroy(&dm_thin_pool_table.mutex);
540 static void __pool_table_insert(struct pool *pool)
542 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
543 list_add(&pool->list, &dm_thin_pool_table.pools);
546 static void __pool_table_remove(struct pool *pool)
548 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
549 list_del(&pool->list);
552 static struct pool *__pool_table_lookup(struct mapped_device *md)
554 struct pool *pool = NULL, *tmp;
556 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
558 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
559 if (tmp->pool_md == md) {
568 static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev)
570 struct pool *pool = NULL, *tmp;
572 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
574 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
575 if (tmp->md_dev == md_dev) {
584 /*----------------------------------------------------------------*/
586 struct dm_thin_endio_hook {
588 struct dm_deferred_entry *shared_read_entry;
589 struct dm_deferred_entry *all_io_entry;
590 struct dm_thin_new_mapping *overwrite_mapping;
591 struct rb_node rb_node;
592 struct dm_bio_prison_cell *cell;
595 static void __merge_bio_list(struct bio_list *bios, struct bio_list *master)
597 bio_list_merge(bios, master);
598 bio_list_init(master);
601 static void error_bio_list(struct bio_list *bios, blk_status_t error)
605 while ((bio = bio_list_pop(bios))) {
606 bio->bi_status = error;
611 static void error_thin_bio_list(struct thin_c *tc, struct bio_list *master,
614 struct bio_list bios;
616 bio_list_init(&bios);
618 spin_lock_irq(&tc->lock);
619 __merge_bio_list(&bios, master);
620 spin_unlock_irq(&tc->lock);
622 error_bio_list(&bios, error);
625 static void requeue_deferred_cells(struct thin_c *tc)
627 struct pool *pool = tc->pool;
628 struct list_head cells;
629 struct dm_bio_prison_cell *cell, *tmp;
631 INIT_LIST_HEAD(&cells);
633 spin_lock_irq(&tc->lock);
634 list_splice_init(&tc->deferred_cells, &cells);
635 spin_unlock_irq(&tc->lock);
637 list_for_each_entry_safe(cell, tmp, &cells, user_list)
638 cell_requeue(pool, cell);
641 static void requeue_io(struct thin_c *tc)
643 struct bio_list bios;
645 bio_list_init(&bios);
647 spin_lock_irq(&tc->lock);
648 __merge_bio_list(&bios, &tc->deferred_bio_list);
649 __merge_bio_list(&bios, &tc->retry_on_resume_list);
650 spin_unlock_irq(&tc->lock);
652 error_bio_list(&bios, BLK_STS_DM_REQUEUE);
653 requeue_deferred_cells(tc);
656 static void error_retry_list_with_code(struct pool *pool, blk_status_t error)
661 list_for_each_entry_rcu(tc, &pool->active_thins, list)
662 error_thin_bio_list(tc, &tc->retry_on_resume_list, error);
666 static void error_retry_list(struct pool *pool)
668 error_retry_list_with_code(pool, get_pool_io_error_code(pool));
672 * This section of code contains the logic for processing a thin device's IO.
673 * Much of the code depends on pool object resources (lists, workqueues, etc)
674 * but most is exclusively called from the thin target rather than the thin-pool
678 static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
680 struct pool *pool = tc->pool;
681 sector_t block_nr = bio->bi_iter.bi_sector;
683 if (block_size_is_power_of_two(pool))
684 block_nr >>= pool->sectors_per_block_shift;
686 (void) sector_div(block_nr, pool->sectors_per_block);
692 * Returns the _complete_ blocks that this bio covers.
694 static void get_bio_block_range(struct thin_c *tc, struct bio *bio,
695 dm_block_t *begin, dm_block_t *end)
697 struct pool *pool = tc->pool;
698 sector_t b = bio->bi_iter.bi_sector;
699 sector_t e = b + (bio->bi_iter.bi_size >> SECTOR_SHIFT);
701 b += pool->sectors_per_block - 1ull; /* so we round up */
703 if (block_size_is_power_of_two(pool)) {
704 b >>= pool->sectors_per_block_shift;
705 e >>= pool->sectors_per_block_shift;
707 (void) sector_div(b, pool->sectors_per_block);
708 (void) sector_div(e, pool->sectors_per_block);
712 /* Can happen if the bio is within a single block. */
720 static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
722 struct pool *pool = tc->pool;
723 sector_t bi_sector = bio->bi_iter.bi_sector;
725 bio_set_dev(bio, tc->pool_dev->bdev);
726 if (block_size_is_power_of_two(pool)) {
727 bio->bi_iter.bi_sector =
728 (block << pool->sectors_per_block_shift) |
729 (bi_sector & (pool->sectors_per_block - 1));
731 bio->bi_iter.bi_sector = (block * pool->sectors_per_block) +
732 sector_div(bi_sector, pool->sectors_per_block);
736 static void remap_to_origin(struct thin_c *tc, struct bio *bio)
738 bio_set_dev(bio, tc->origin_dev->bdev);
741 static int bio_triggers_commit(struct thin_c *tc, struct bio *bio)
743 return op_is_flush(bio->bi_opf) &&
744 dm_thin_changed_this_transaction(tc->td);
747 static void inc_all_io_entry(struct pool *pool, struct bio *bio)
749 struct dm_thin_endio_hook *h;
751 if (bio_op(bio) == REQ_OP_DISCARD)
754 h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
755 h->all_io_entry = dm_deferred_entry_inc(pool->all_io_ds);
758 static void issue(struct thin_c *tc, struct bio *bio)
760 struct pool *pool = tc->pool;
762 if (!bio_triggers_commit(tc, bio)) {
763 dm_submit_bio_remap(bio, NULL);
768 * Complete bio with an error if earlier I/O caused changes to
769 * the metadata that can't be committed e.g, due to I/O errors
770 * on the metadata device.
772 if (dm_thin_aborted_changes(tc->td)) {
778 * Batch together any bios that trigger commits and then issue a
779 * single commit for them in process_deferred_bios().
781 spin_lock_irq(&pool->lock);
782 bio_list_add(&pool->deferred_flush_bios, bio);
783 spin_unlock_irq(&pool->lock);
786 static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio)
788 remap_to_origin(tc, bio);
792 static void remap_and_issue(struct thin_c *tc, struct bio *bio,
795 remap(tc, bio, block);
799 /*----------------------------------------------------------------*/
802 * Bio endio functions.
804 struct dm_thin_new_mapping {
805 struct list_head list;
811 * Track quiescing, copying and zeroing preparation actions. When this
812 * counter hits zero the block is prepared and can be inserted into the
815 atomic_t prepare_actions;
819 dm_block_t virt_begin, virt_end;
820 dm_block_t data_block;
821 struct dm_bio_prison_cell *cell;
824 * If the bio covers the whole area of a block then we can avoid
825 * zeroing or copying. Instead this bio is hooked. The bio will
826 * still be in the cell, so care has to be taken to avoid issuing
830 bio_end_io_t *saved_bi_end_io;
833 static void __complete_mapping_preparation(struct dm_thin_new_mapping *m)
835 struct pool *pool = m->tc->pool;
837 if (atomic_dec_and_test(&m->prepare_actions)) {
838 list_add_tail(&m->list, &pool->prepared_mappings);
843 static void complete_mapping_preparation(struct dm_thin_new_mapping *m)
846 struct pool *pool = m->tc->pool;
848 spin_lock_irqsave(&pool->lock, flags);
849 __complete_mapping_preparation(m);
850 spin_unlock_irqrestore(&pool->lock, flags);
853 static void copy_complete(int read_err, unsigned long write_err, void *context)
855 struct dm_thin_new_mapping *m = context;
857 m->status = read_err || write_err ? BLK_STS_IOERR : 0;
858 complete_mapping_preparation(m);
861 static void overwrite_endio(struct bio *bio)
863 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
864 struct dm_thin_new_mapping *m = h->overwrite_mapping;
866 bio->bi_end_io = m->saved_bi_end_io;
868 m->status = bio->bi_status;
869 complete_mapping_preparation(m);
872 /*----------------------------------------------------------------*/
879 * Prepared mapping jobs.
883 * This sends the bios in the cell, except the original holder, back
884 * to the deferred_bios list.
886 static void cell_defer_no_holder(struct thin_c *tc, struct dm_bio_prison_cell *cell)
888 struct pool *pool = tc->pool;
890 struct bio_list bios;
892 bio_list_init(&bios);
893 cell_release_no_holder(pool, cell, &bios);
895 if (!bio_list_empty(&bios)) {
896 spin_lock_irqsave(&tc->lock, flags);
897 bio_list_merge(&tc->deferred_bio_list, &bios);
898 spin_unlock_irqrestore(&tc->lock, flags);
903 static void thin_defer_bio(struct thin_c *tc, struct bio *bio);
907 struct bio_list defer_bios;
908 struct bio_list issue_bios;
911 static void __inc_remap_and_issue_cell(void *context,
912 struct dm_bio_prison_cell *cell)
914 struct remap_info *info = context;
917 while ((bio = bio_list_pop(&cell->bios))) {
918 if (op_is_flush(bio->bi_opf) || bio_op(bio) == REQ_OP_DISCARD)
919 bio_list_add(&info->defer_bios, bio);
921 inc_all_io_entry(info->tc->pool, bio);
924 * We can't issue the bios with the bio prison lock
925 * held, so we add them to a list to issue on
926 * return from this function.
928 bio_list_add(&info->issue_bios, bio);
933 static void inc_remap_and_issue_cell(struct thin_c *tc,
934 struct dm_bio_prison_cell *cell,
938 struct remap_info info;
941 bio_list_init(&info.defer_bios);
942 bio_list_init(&info.issue_bios);
945 * We have to be careful to inc any bios we're about to issue
946 * before the cell is released, and avoid a race with new bios
947 * being added to the cell.
949 cell_visit_release(tc->pool, __inc_remap_and_issue_cell,
952 while ((bio = bio_list_pop(&info.defer_bios)))
953 thin_defer_bio(tc, bio);
955 while ((bio = bio_list_pop(&info.issue_bios)))
956 remap_and_issue(info.tc, bio, block);
959 static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
961 cell_error(m->tc->pool, m->cell);
963 mempool_free(m, &m->tc->pool->mapping_pool);
966 static void complete_overwrite_bio(struct thin_c *tc, struct bio *bio)
968 struct pool *pool = tc->pool;
971 * If the bio has the REQ_FUA flag set we must commit the metadata
972 * before signaling its completion.
974 if (!bio_triggers_commit(tc, bio)) {
980 * Complete bio with an error if earlier I/O caused changes to the
981 * metadata that can't be committed, e.g, due to I/O errors on the
984 if (dm_thin_aborted_changes(tc->td)) {
990 * Batch together any bios that trigger commits and then issue a
991 * single commit for them in process_deferred_bios().
993 spin_lock_irq(&pool->lock);
994 bio_list_add(&pool->deferred_flush_completions, bio);
995 spin_unlock_irq(&pool->lock);
998 static void process_prepared_mapping(struct dm_thin_new_mapping *m)
1000 struct thin_c *tc = m->tc;
1001 struct pool *pool = tc->pool;
1002 struct bio *bio = m->bio;
1006 cell_error(pool, m->cell);
1011 * Commit the prepared block into the mapping btree.
1012 * Any I/O for this block arriving after this point will get
1013 * remapped to it directly.
1015 r = dm_thin_insert_block(tc->td, m->virt_begin, m->data_block);
1017 metadata_operation_failed(pool, "dm_thin_insert_block", r);
1018 cell_error(pool, m->cell);
1023 * Release any bios held while the block was being provisioned.
1024 * If we are processing a write bio that completely covers the block,
1025 * we already processed it so can ignore it now when processing
1026 * the bios in the cell.
1029 inc_remap_and_issue_cell(tc, m->cell, m->data_block);
1030 complete_overwrite_bio(tc, bio);
1032 inc_all_io_entry(tc->pool, m->cell->holder);
1033 remap_and_issue(tc, m->cell->holder, m->data_block);
1034 inc_remap_and_issue_cell(tc, m->cell, m->data_block);
1039 mempool_free(m, &pool->mapping_pool);
1042 /*----------------------------------------------------------------*/
1044 static void free_discard_mapping(struct dm_thin_new_mapping *m)
1046 struct thin_c *tc = m->tc;
1049 cell_defer_no_holder(tc, m->cell);
1050 mempool_free(m, &tc->pool->mapping_pool);
1053 static void process_prepared_discard_fail(struct dm_thin_new_mapping *m)
1055 bio_io_error(m->bio);
1056 free_discard_mapping(m);
1059 static void process_prepared_discard_success(struct dm_thin_new_mapping *m)
1062 free_discard_mapping(m);
1065 static void process_prepared_discard_no_passdown(struct dm_thin_new_mapping *m)
1068 struct thin_c *tc = m->tc;
1070 r = dm_thin_remove_range(tc->td, m->cell->key.block_begin, m->cell->key.block_end);
1072 metadata_operation_failed(tc->pool, "dm_thin_remove_range", r);
1073 bio_io_error(m->bio);
1077 cell_defer_no_holder(tc, m->cell);
1078 mempool_free(m, &tc->pool->mapping_pool);
1081 /*----------------------------------------------------------------*/
1083 static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m,
1084 struct bio *discard_parent)
1087 * We've already unmapped this range of blocks, but before we
1088 * passdown we have to check that these blocks are now unused.
1092 struct thin_c *tc = m->tc;
1093 struct pool *pool = tc->pool;
1094 dm_block_t b = m->data_block, e, end = m->data_block + m->virt_end - m->virt_begin;
1095 struct discard_op op;
1097 begin_discard(&op, tc, discard_parent);
1099 /* find start of unmapped run */
1100 for (; b < end; b++) {
1101 r = dm_pool_block_is_shared(pool->pmd, b, &shared);
1112 /* find end of run */
1113 for (e = b + 1; e != end; e++) {
1114 r = dm_pool_block_is_shared(pool->pmd, e, &shared);
1122 r = issue_discard(&op, b, e);
1129 end_discard(&op, r);
1132 static void queue_passdown_pt2(struct dm_thin_new_mapping *m)
1134 unsigned long flags;
1135 struct pool *pool = m->tc->pool;
1137 spin_lock_irqsave(&pool->lock, flags);
1138 list_add_tail(&m->list, &pool->prepared_discards_pt2);
1139 spin_unlock_irqrestore(&pool->lock, flags);
1143 static void passdown_endio(struct bio *bio)
1146 * It doesn't matter if the passdown discard failed, we still want
1147 * to unmap (we ignore err).
1149 queue_passdown_pt2(bio->bi_private);
1153 static void process_prepared_discard_passdown_pt1(struct dm_thin_new_mapping *m)
1156 struct thin_c *tc = m->tc;
1157 struct pool *pool = tc->pool;
1158 struct bio *discard_parent;
1159 dm_block_t data_end = m->data_block + (m->virt_end - m->virt_begin);
1162 * Only this thread allocates blocks, so we can be sure that the
1163 * newly unmapped blocks will not be allocated before the end of
1166 r = dm_thin_remove_range(tc->td, m->virt_begin, m->virt_end);
1168 metadata_operation_failed(pool, "dm_thin_remove_range", r);
1169 bio_io_error(m->bio);
1170 cell_defer_no_holder(tc, m->cell);
1171 mempool_free(m, &pool->mapping_pool);
1176 * Increment the unmapped blocks. This prevents a race between the
1177 * passdown io and reallocation of freed blocks.
1179 r = dm_pool_inc_data_range(pool->pmd, m->data_block, data_end);
1181 metadata_operation_failed(pool, "dm_pool_inc_data_range", r);
1182 bio_io_error(m->bio);
1183 cell_defer_no_holder(tc, m->cell);
1184 mempool_free(m, &pool->mapping_pool);
1188 discard_parent = bio_alloc(NULL, 1, 0, GFP_NOIO);
1189 discard_parent->bi_end_io = passdown_endio;
1190 discard_parent->bi_private = m;
1191 if (m->maybe_shared)
1192 passdown_double_checking_shared_status(m, discard_parent);
1194 struct discard_op op;
1196 begin_discard(&op, tc, discard_parent);
1197 r = issue_discard(&op, m->data_block, data_end);
1198 end_discard(&op, r);
1202 static void process_prepared_discard_passdown_pt2(struct dm_thin_new_mapping *m)
1205 struct thin_c *tc = m->tc;
1206 struct pool *pool = tc->pool;
1209 * The passdown has completed, so now we can decrement all those
1212 r = dm_pool_dec_data_range(pool->pmd, m->data_block,
1213 m->data_block + (m->virt_end - m->virt_begin));
1215 metadata_operation_failed(pool, "dm_pool_dec_data_range", r);
1216 bio_io_error(m->bio);
1220 cell_defer_no_holder(tc, m->cell);
1221 mempool_free(m, &pool->mapping_pool);
1224 static void process_prepared(struct pool *pool, struct list_head *head,
1225 process_mapping_fn *fn)
1227 struct list_head maps;
1228 struct dm_thin_new_mapping *m, *tmp;
1230 INIT_LIST_HEAD(&maps);
1231 spin_lock_irq(&pool->lock);
1232 list_splice_init(head, &maps);
1233 spin_unlock_irq(&pool->lock);
1235 list_for_each_entry_safe(m, tmp, &maps, list)
1240 * Deferred bio jobs.
1242 static int io_overlaps_block(struct pool *pool, struct bio *bio)
1244 return bio->bi_iter.bi_size ==
1245 (pool->sectors_per_block << SECTOR_SHIFT);
1248 static int io_overwrites_block(struct pool *pool, struct bio *bio)
1250 return (bio_data_dir(bio) == WRITE) &&
1251 io_overlaps_block(pool, bio);
1254 static void save_and_set_endio(struct bio *bio, bio_end_io_t **save,
1257 *save = bio->bi_end_io;
1258 bio->bi_end_io = fn;
1261 static int ensure_next_mapping(struct pool *pool)
1263 if (pool->next_mapping)
1266 pool->next_mapping = mempool_alloc(&pool->mapping_pool, GFP_ATOMIC);
1268 return pool->next_mapping ? 0 : -ENOMEM;
1271 static struct dm_thin_new_mapping *get_next_mapping(struct pool *pool)
1273 struct dm_thin_new_mapping *m = pool->next_mapping;
1275 BUG_ON(!pool->next_mapping);
1277 memset(m, 0, sizeof(struct dm_thin_new_mapping));
1278 INIT_LIST_HEAD(&m->list);
1281 pool->next_mapping = NULL;
1286 static void ll_zero(struct thin_c *tc, struct dm_thin_new_mapping *m,
1287 sector_t begin, sector_t end)
1289 struct dm_io_region to;
1291 to.bdev = tc->pool_dev->bdev;
1293 to.count = end - begin;
1295 dm_kcopyd_zero(tc->pool->copier, 1, &to, 0, copy_complete, m);
1298 static void remap_and_issue_overwrite(struct thin_c *tc, struct bio *bio,
1299 dm_block_t data_begin,
1300 struct dm_thin_new_mapping *m)
1302 struct pool *pool = tc->pool;
1303 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
1305 h->overwrite_mapping = m;
1307 save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
1308 inc_all_io_entry(pool, bio);
1309 remap_and_issue(tc, bio, data_begin);
1313 * A partial copy also needs to zero the uncopied region.
1315 static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
1316 struct dm_dev *origin, dm_block_t data_origin,
1317 dm_block_t data_dest,
1318 struct dm_bio_prison_cell *cell, struct bio *bio,
1321 struct pool *pool = tc->pool;
1322 struct dm_thin_new_mapping *m = get_next_mapping(pool);
1325 m->virt_begin = virt_block;
1326 m->virt_end = virt_block + 1u;
1327 m->data_block = data_dest;
1331 * quiesce action + copy action + an extra reference held for the
1332 * duration of this function (we may need to inc later for a
1335 atomic_set(&m->prepare_actions, 3);
1337 if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list))
1338 complete_mapping_preparation(m); /* already quiesced */
1341 * IO to pool_dev remaps to the pool target's data_dev.
1343 * If the whole block of data is being overwritten, we can issue the
1344 * bio immediately. Otherwise we use kcopyd to clone the data first.
1346 if (io_overwrites_block(pool, bio))
1347 remap_and_issue_overwrite(tc, bio, data_dest, m);
1349 struct dm_io_region from, to;
1351 from.bdev = origin->bdev;
1352 from.sector = data_origin * pool->sectors_per_block;
1355 to.bdev = tc->pool_dev->bdev;
1356 to.sector = data_dest * pool->sectors_per_block;
1359 dm_kcopyd_copy(pool->copier, &from, 1, &to,
1360 0, copy_complete, m);
1363 * Do we need to zero a tail region?
1365 if (len < pool->sectors_per_block && pool->pf.zero_new_blocks) {
1366 atomic_inc(&m->prepare_actions);
1368 data_dest * pool->sectors_per_block + len,
1369 (data_dest + 1) * pool->sectors_per_block);
1373 complete_mapping_preparation(m); /* drop our ref */
1376 static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block,
1377 dm_block_t data_origin, dm_block_t data_dest,
1378 struct dm_bio_prison_cell *cell, struct bio *bio)
1380 schedule_copy(tc, virt_block, tc->pool_dev,
1381 data_origin, data_dest, cell, bio,
1382 tc->pool->sectors_per_block);
1385 static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
1386 dm_block_t data_block, struct dm_bio_prison_cell *cell,
1389 struct pool *pool = tc->pool;
1390 struct dm_thin_new_mapping *m = get_next_mapping(pool);
1392 atomic_set(&m->prepare_actions, 1); /* no need to quiesce */
1394 m->virt_begin = virt_block;
1395 m->virt_end = virt_block + 1u;
1396 m->data_block = data_block;
1400 * If the whole block of data is being overwritten or we are not
1401 * zeroing pre-existing data, we can issue the bio immediately.
1402 * Otherwise we use kcopyd to zero the data first.
1404 if (pool->pf.zero_new_blocks) {
1405 if (io_overwrites_block(pool, bio))
1406 remap_and_issue_overwrite(tc, bio, data_block, m);
1408 ll_zero(tc, m, data_block * pool->sectors_per_block,
1409 (data_block + 1) * pool->sectors_per_block);
1412 process_prepared_mapping(m);
1415 static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block,
1416 dm_block_t data_dest,
1417 struct dm_bio_prison_cell *cell, struct bio *bio)
1419 struct pool *pool = tc->pool;
1420 sector_t virt_block_begin = virt_block * pool->sectors_per_block;
1421 sector_t virt_block_end = (virt_block + 1) * pool->sectors_per_block;
1423 if (virt_block_end <= tc->origin_size) {
1424 schedule_copy(tc, virt_block, tc->origin_dev,
1425 virt_block, data_dest, cell, bio,
1426 pool->sectors_per_block);
1428 } else if (virt_block_begin < tc->origin_size) {
1429 schedule_copy(tc, virt_block, tc->origin_dev,
1430 virt_block, data_dest, cell, bio,
1431 tc->origin_size - virt_block_begin);
1434 schedule_zero(tc, virt_block, data_dest, cell, bio);
1437 static void set_pool_mode(struct pool *pool, enum pool_mode new_mode);
1439 static void requeue_bios(struct pool *pool);
1441 static bool is_read_only_pool_mode(enum pool_mode mode)
1443 return (mode == PM_OUT_OF_METADATA_SPACE || mode == PM_READ_ONLY);
1446 static bool is_read_only(struct pool *pool)
1448 return is_read_only_pool_mode(get_pool_mode(pool));
1451 static void check_for_metadata_space(struct pool *pool)
1454 const char *ooms_reason = NULL;
1457 r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free);
1459 ooms_reason = "Could not get free metadata blocks";
1461 ooms_reason = "No free metadata blocks";
1463 if (ooms_reason && !is_read_only(pool)) {
1464 DMERR("%s", ooms_reason);
1465 set_pool_mode(pool, PM_OUT_OF_METADATA_SPACE);
1469 static void check_for_data_space(struct pool *pool)
1474 if (get_pool_mode(pool) != PM_OUT_OF_DATA_SPACE)
1477 r = dm_pool_get_free_block_count(pool->pmd, &nr_free);
1482 set_pool_mode(pool, PM_WRITE);
1488 * A non-zero return indicates read_only or fail_io mode.
1489 * Many callers don't care about the return value.
1491 static int commit(struct pool *pool)
1495 if (get_pool_mode(pool) >= PM_OUT_OF_METADATA_SPACE)
1498 r = dm_pool_commit_metadata(pool->pmd);
1500 metadata_operation_failed(pool, "dm_pool_commit_metadata", r);
1502 check_for_metadata_space(pool);
1503 check_for_data_space(pool);
1509 static void check_low_water_mark(struct pool *pool, dm_block_t free_blocks)
1511 if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) {
1512 DMWARN("%s: reached low water mark for data device: sending event.",
1513 dm_device_name(pool->pool_md));
1514 spin_lock_irq(&pool->lock);
1515 pool->low_water_triggered = true;
1516 spin_unlock_irq(&pool->lock);
1517 dm_table_event(pool->ti->table);
1521 static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
1524 dm_block_t free_blocks;
1525 struct pool *pool = tc->pool;
1527 if (WARN_ON(get_pool_mode(pool) != PM_WRITE))
1530 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
1532 metadata_operation_failed(pool, "dm_pool_get_free_block_count", r);
1536 check_low_water_mark(pool, free_blocks);
1540 * Try to commit to see if that will free up some
1547 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
1549 metadata_operation_failed(pool, "dm_pool_get_free_block_count", r);
1554 set_pool_mode(pool, PM_OUT_OF_DATA_SPACE);
1559 r = dm_pool_alloc_data_block(pool->pmd, result);
1562 set_pool_mode(pool, PM_OUT_OF_DATA_SPACE);
1564 metadata_operation_failed(pool, "dm_pool_alloc_data_block", r);
1568 r = dm_pool_get_free_metadata_block_count(pool->pmd, &free_blocks);
1570 metadata_operation_failed(pool, "dm_pool_get_free_metadata_block_count", r);
1575 /* Let's commit before we use up the metadata reserve. */
1585 * If we have run out of space, queue bios until the device is
1586 * resumed, presumably after having been reloaded with more space.
1588 static void retry_on_resume(struct bio *bio)
1590 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
1591 struct thin_c *tc = h->tc;
1593 spin_lock_irq(&tc->lock);
1594 bio_list_add(&tc->retry_on_resume_list, bio);
1595 spin_unlock_irq(&tc->lock);
1598 static blk_status_t should_error_unserviceable_bio(struct pool *pool)
1600 enum pool_mode m = get_pool_mode(pool);
1604 /* Shouldn't get here */
1605 DMERR_LIMIT("bio unserviceable, yet pool is in PM_WRITE mode");
1606 return BLK_STS_IOERR;
1608 case PM_OUT_OF_DATA_SPACE:
1609 return pool->pf.error_if_no_space ? BLK_STS_NOSPC : 0;
1611 case PM_OUT_OF_METADATA_SPACE:
1614 return BLK_STS_IOERR;
1616 /* Shouldn't get here */
1617 DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode");
1618 return BLK_STS_IOERR;
1622 static void handle_unserviceable_bio(struct pool *pool, struct bio *bio)
1624 blk_status_t error = should_error_unserviceable_bio(pool);
1627 bio->bi_status = error;
1630 retry_on_resume(bio);
1633 static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *cell)
1636 struct bio_list bios;
1639 error = should_error_unserviceable_bio(pool);
1641 cell_error_with_code(pool, cell, error);
1645 bio_list_init(&bios);
1646 cell_release(pool, cell, &bios);
1648 while ((bio = bio_list_pop(&bios)))
1649 retry_on_resume(bio);
1652 static void process_discard_cell_no_passdown(struct thin_c *tc,
1653 struct dm_bio_prison_cell *virt_cell)
1655 struct pool *pool = tc->pool;
1656 struct dm_thin_new_mapping *m = get_next_mapping(pool);
1659 * We don't need to lock the data blocks, since there's no
1660 * passdown. We only lock data blocks for allocation and breaking sharing.
1663 m->virt_begin = virt_cell->key.block_begin;
1664 m->virt_end = virt_cell->key.block_end;
1665 m->cell = virt_cell;
1666 m->bio = virt_cell->holder;
1668 if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list))
1669 pool->process_prepared_discard(m);
1672 static void break_up_discard_bio(struct thin_c *tc, dm_block_t begin, dm_block_t end,
1675 struct pool *pool = tc->pool;
1679 struct dm_cell_key data_key;
1680 struct dm_bio_prison_cell *data_cell;
1681 struct dm_thin_new_mapping *m;
1682 dm_block_t virt_begin, virt_end, data_begin, data_end;
1683 dm_block_t len, next_boundary;
1685 while (begin != end) {
1686 r = dm_thin_find_mapped_range(tc->td, begin, end, &virt_begin, &virt_end,
1687 &data_begin, &maybe_shared);
1690 * Silently fail, letting any mappings we've
1696 data_end = data_begin + (virt_end - virt_begin);
1699 * Make sure the data region obeys the bio prison restrictions.
1701 while (data_begin < data_end) {
1702 r = ensure_next_mapping(pool);
1704 return; /* we did our best */
1706 next_boundary = ((data_begin >> BIO_PRISON_MAX_RANGE_SHIFT) + 1)
1707 << BIO_PRISON_MAX_RANGE_SHIFT;
1708 len = min_t(sector_t, data_end - data_begin, next_boundary - data_begin);
1710 /* This key is certainly within range given the above splitting */
1711 (void) build_key(tc->td, PHYSICAL, data_begin, data_begin + len, &data_key);
1712 if (bio_detain(tc->pool, &data_key, NULL, &data_cell)) {
1713 /* contention, we'll give up with this range */
1719 * IO may still be going to the destination block. We must
1720 * quiesce before we can do the removal.
1722 m = get_next_mapping(pool);
1724 m->maybe_shared = maybe_shared;
1725 m->virt_begin = virt_begin;
1726 m->virt_end = virt_begin + len;
1727 m->data_block = data_begin;
1728 m->cell = data_cell;
1732 * The parent bio must not complete before sub discard bios are
1733 * chained to it (see end_discard's bio_chain)!
1735 * This per-mapping bi_remaining increment is paired with
1736 * the implicit decrement that occurs via bio_endio() in
1739 bio_inc_remaining(bio);
1740 if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list))
1741 pool->process_prepared_discard(m);
1751 static void process_discard_cell_passdown(struct thin_c *tc, struct dm_bio_prison_cell *virt_cell)
1753 struct bio *bio = virt_cell->holder;
1754 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
1757 * The virt_cell will only get freed once the origin bio completes.
1758 * This means it will remain locked while all the individual
1759 * passdown bios are in flight.
1761 h->cell = virt_cell;
1762 break_up_discard_bio(tc, virt_cell->key.block_begin, virt_cell->key.block_end, bio);
1765 * We complete the bio now, knowing that the bi_remaining field
1766 * will prevent completion until the sub range discards have
1772 static void process_discard_bio(struct thin_c *tc, struct bio *bio)
1774 dm_block_t begin, end;
1775 struct dm_cell_key virt_key;
1776 struct dm_bio_prison_cell *virt_cell;
1778 get_bio_block_range(tc, bio, &begin, &end);
1781 * The discard covers less than a block.
1787 if (unlikely(!build_key(tc->td, VIRTUAL, begin, end, &virt_key))) {
1788 DMERR_LIMIT("Discard doesn't respect bio prison limits");
1793 if (bio_detain(tc->pool, &virt_key, bio, &virt_cell)) {
1795 * Potential starvation issue: We're relying on the
1796 * fs/application being well behaved, and not trying to
1797 * send IO to a region at the same time as discarding it.
1798 * If they do this persistently then it's possible this
1799 * cell will never be granted.
1804 tc->pool->process_discard_cell(tc, virt_cell);
1807 static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
1808 struct dm_cell_key *key,
1809 struct dm_thin_lookup_result *lookup_result,
1810 struct dm_bio_prison_cell *cell)
1813 dm_block_t data_block;
1814 struct pool *pool = tc->pool;
1816 r = alloc_data_block(tc, &data_block);
1819 schedule_internal_copy(tc, block, lookup_result->block,
1820 data_block, cell, bio);
1824 retry_bios_on_resume(pool, cell);
1828 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1830 cell_error(pool, cell);
1835 static void __remap_and_issue_shared_cell(void *context,
1836 struct dm_bio_prison_cell *cell)
1838 struct remap_info *info = context;
1841 while ((bio = bio_list_pop(&cell->bios))) {
1842 if (bio_data_dir(bio) == WRITE || op_is_flush(bio->bi_opf) ||
1843 bio_op(bio) == REQ_OP_DISCARD)
1844 bio_list_add(&info->defer_bios, bio);
1846 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
1848 h->shared_read_entry = dm_deferred_entry_inc(info->tc->pool->shared_read_ds);
1849 inc_all_io_entry(info->tc->pool, bio);
1850 bio_list_add(&info->issue_bios, bio);
1855 static void remap_and_issue_shared_cell(struct thin_c *tc,
1856 struct dm_bio_prison_cell *cell,
1860 struct remap_info info;
1863 bio_list_init(&info.defer_bios);
1864 bio_list_init(&info.issue_bios);
1866 cell_visit_release(tc->pool, __remap_and_issue_shared_cell,
1869 while ((bio = bio_list_pop(&info.defer_bios)))
1870 thin_defer_bio(tc, bio);
1872 while ((bio = bio_list_pop(&info.issue_bios)))
1873 remap_and_issue(tc, bio, block);
1876 static void process_shared_bio(struct thin_c *tc, struct bio *bio,
1878 struct dm_thin_lookup_result *lookup_result,
1879 struct dm_bio_prison_cell *virt_cell)
1881 struct dm_bio_prison_cell *data_cell;
1882 struct pool *pool = tc->pool;
1883 struct dm_cell_key key;
1886 * If cell is already occupied, then sharing is already in the process
1887 * of being broken so we have nothing further to do here.
1889 build_data_key(tc->td, lookup_result->block, &key);
1890 if (bio_detain(pool, &key, bio, &data_cell)) {
1891 cell_defer_no_holder(tc, virt_cell);
1895 if (bio_data_dir(bio) == WRITE && bio->bi_iter.bi_size) {
1896 break_sharing(tc, bio, block, &key, lookup_result, data_cell);
1897 cell_defer_no_holder(tc, virt_cell);
1899 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
1901 h->shared_read_entry = dm_deferred_entry_inc(pool->shared_read_ds);
1902 inc_all_io_entry(pool, bio);
1903 remap_and_issue(tc, bio, lookup_result->block);
1905 remap_and_issue_shared_cell(tc, data_cell, lookup_result->block);
1906 remap_and_issue_shared_cell(tc, virt_cell, lookup_result->block);
1910 static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block,
1911 struct dm_bio_prison_cell *cell)
1914 dm_block_t data_block;
1915 struct pool *pool = tc->pool;
1918 * Remap empty bios (flushes) immediately, without provisioning.
1920 if (!bio->bi_iter.bi_size) {
1921 inc_all_io_entry(pool, bio);
1922 cell_defer_no_holder(tc, cell);
1924 remap_and_issue(tc, bio, 0);
1929 * Fill read bios with zeroes and complete them immediately.
1931 if (bio_data_dir(bio) == READ) {
1933 cell_defer_no_holder(tc, cell);
1938 r = alloc_data_block(tc, &data_block);
1942 schedule_external_copy(tc, block, data_block, cell, bio);
1944 schedule_zero(tc, block, data_block, cell, bio);
1948 retry_bios_on_resume(pool, cell);
1952 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1954 cell_error(pool, cell);
1959 static void process_cell(struct thin_c *tc, struct dm_bio_prison_cell *cell)
1962 struct pool *pool = tc->pool;
1963 struct bio *bio = cell->holder;
1964 dm_block_t block = get_bio_block(tc, bio);
1965 struct dm_thin_lookup_result lookup_result;
1967 if (tc->requeue_mode) {
1968 cell_requeue(pool, cell);
1972 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1975 if (lookup_result.shared)
1976 process_shared_bio(tc, bio, block, &lookup_result, cell);
1978 inc_all_io_entry(pool, bio);
1979 remap_and_issue(tc, bio, lookup_result.block);
1980 inc_remap_and_issue_cell(tc, cell, lookup_result.block);
1985 if (bio_data_dir(bio) == READ && tc->origin_dev) {
1986 inc_all_io_entry(pool, bio);
1987 cell_defer_no_holder(tc, cell);
1989 if (bio_end_sector(bio) <= tc->origin_size)
1990 remap_to_origin_and_issue(tc, bio);
1992 else if (bio->bi_iter.bi_sector < tc->origin_size) {
1994 bio->bi_iter.bi_size = (tc->origin_size - bio->bi_iter.bi_sector) << SECTOR_SHIFT;
1995 remap_to_origin_and_issue(tc, bio);
2002 provision_block(tc, bio, block, cell);
2006 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
2008 cell_defer_no_holder(tc, cell);
2014 static void process_bio(struct thin_c *tc, struct bio *bio)
2016 struct pool *pool = tc->pool;
2017 dm_block_t block = get_bio_block(tc, bio);
2018 struct dm_bio_prison_cell *cell;
2019 struct dm_cell_key key;
2022 * If cell is already occupied, then the block is already
2023 * being provisioned so we have nothing further to do here.
2025 build_virtual_key(tc->td, block, &key);
2026 if (bio_detain(pool, &key, bio, &cell))
2029 process_cell(tc, cell);
2032 static void __process_bio_read_only(struct thin_c *tc, struct bio *bio,
2033 struct dm_bio_prison_cell *cell)
2036 int rw = bio_data_dir(bio);
2037 dm_block_t block = get_bio_block(tc, bio);
2038 struct dm_thin_lookup_result lookup_result;
2040 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
2043 if (lookup_result.shared && (rw == WRITE) && bio->bi_iter.bi_size) {
2044 handle_unserviceable_bio(tc->pool, bio);
2046 cell_defer_no_holder(tc, cell);
2048 inc_all_io_entry(tc->pool, bio);
2049 remap_and_issue(tc, bio, lookup_result.block);
2051 inc_remap_and_issue_cell(tc, cell, lookup_result.block);
2057 cell_defer_no_holder(tc, cell);
2059 handle_unserviceable_bio(tc->pool, bio);
2063 if (tc->origin_dev) {
2064 inc_all_io_entry(tc->pool, bio);
2065 remap_to_origin_and_issue(tc, bio);
2074 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
2077 cell_defer_no_holder(tc, cell);
2083 static void process_bio_read_only(struct thin_c *tc, struct bio *bio)
2085 __process_bio_read_only(tc, bio, NULL);
2088 static void process_cell_read_only(struct thin_c *tc, struct dm_bio_prison_cell *cell)
2090 __process_bio_read_only(tc, cell->holder, cell);
2093 static void process_bio_success(struct thin_c *tc, struct bio *bio)
2098 static void process_bio_fail(struct thin_c *tc, struct bio *bio)
2103 static void process_cell_success(struct thin_c *tc, struct dm_bio_prison_cell *cell)
2105 cell_success(tc->pool, cell);
2108 static void process_cell_fail(struct thin_c *tc, struct dm_bio_prison_cell *cell)
2110 cell_error(tc->pool, cell);
2114 * FIXME: should we also commit due to size of transaction, measured in
2117 static int need_commit_due_to_time(struct pool *pool)
2119 return !time_in_range(jiffies, pool->last_commit_jiffies,
2120 pool->last_commit_jiffies + COMMIT_PERIOD);
2123 #define thin_pbd(node) rb_entry((node), struct dm_thin_endio_hook, rb_node)
2124 #define thin_bio(pbd) dm_bio_from_per_bio_data((pbd), sizeof(struct dm_thin_endio_hook))
2126 static void __thin_bio_rb_add(struct thin_c *tc, struct bio *bio)
2128 struct rb_node **rbp, *parent;
2129 struct dm_thin_endio_hook *pbd;
2130 sector_t bi_sector = bio->bi_iter.bi_sector;
2132 rbp = &tc->sort_bio_list.rb_node;
2136 pbd = thin_pbd(parent);
2138 if (bi_sector < thin_bio(pbd)->bi_iter.bi_sector)
2139 rbp = &(*rbp)->rb_left;
2141 rbp = &(*rbp)->rb_right;
2144 pbd = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
2145 rb_link_node(&pbd->rb_node, parent, rbp);
2146 rb_insert_color(&pbd->rb_node, &tc->sort_bio_list);
2149 static void __extract_sorted_bios(struct thin_c *tc)
2151 struct rb_node *node;
2152 struct dm_thin_endio_hook *pbd;
2155 for (node = rb_first(&tc->sort_bio_list); node; node = rb_next(node)) {
2156 pbd = thin_pbd(node);
2157 bio = thin_bio(pbd);
2159 bio_list_add(&tc->deferred_bio_list, bio);
2160 rb_erase(&pbd->rb_node, &tc->sort_bio_list);
2163 WARN_ON(!RB_EMPTY_ROOT(&tc->sort_bio_list));
2166 static void __sort_thin_deferred_bios(struct thin_c *tc)
2169 struct bio_list bios;
2171 bio_list_init(&bios);
2172 bio_list_merge(&bios, &tc->deferred_bio_list);
2173 bio_list_init(&tc->deferred_bio_list);
2175 /* Sort deferred_bio_list using rb-tree */
2176 while ((bio = bio_list_pop(&bios)))
2177 __thin_bio_rb_add(tc, bio);
2180 * Transfer the sorted bios in sort_bio_list back to
2181 * deferred_bio_list to allow lockless submission of
2184 __extract_sorted_bios(tc);
2187 static void process_thin_deferred_bios(struct thin_c *tc)
2189 struct pool *pool = tc->pool;
2191 struct bio_list bios;
2192 struct blk_plug plug;
2193 unsigned int count = 0;
2195 if (tc->requeue_mode) {
2196 error_thin_bio_list(tc, &tc->deferred_bio_list,
2197 BLK_STS_DM_REQUEUE);
2201 bio_list_init(&bios);
2203 spin_lock_irq(&tc->lock);
2205 if (bio_list_empty(&tc->deferred_bio_list)) {
2206 spin_unlock_irq(&tc->lock);
2210 __sort_thin_deferred_bios(tc);
2212 bio_list_merge(&bios, &tc->deferred_bio_list);
2213 bio_list_init(&tc->deferred_bio_list);
2215 spin_unlock_irq(&tc->lock);
2217 blk_start_plug(&plug);
2218 while ((bio = bio_list_pop(&bios))) {
2220 * If we've got no free new_mapping structs, and processing
2221 * this bio might require one, we pause until there are some
2222 * prepared mappings to process.
2224 if (ensure_next_mapping(pool)) {
2225 spin_lock_irq(&tc->lock);
2226 bio_list_add(&tc->deferred_bio_list, bio);
2227 bio_list_merge(&tc->deferred_bio_list, &bios);
2228 spin_unlock_irq(&tc->lock);
2232 if (bio_op(bio) == REQ_OP_DISCARD)
2233 pool->process_discard(tc, bio);
2235 pool->process_bio(tc, bio);
2237 if ((count++ & 127) == 0) {
2238 throttle_work_update(&pool->throttle);
2239 dm_pool_issue_prefetches(pool->pmd);
2243 blk_finish_plug(&plug);
2246 static int cmp_cells(const void *lhs, const void *rhs)
2248 struct dm_bio_prison_cell *lhs_cell = *((struct dm_bio_prison_cell **) lhs);
2249 struct dm_bio_prison_cell *rhs_cell = *((struct dm_bio_prison_cell **) rhs);
2251 BUG_ON(!lhs_cell->holder);
2252 BUG_ON(!rhs_cell->holder);
2254 if (lhs_cell->holder->bi_iter.bi_sector < rhs_cell->holder->bi_iter.bi_sector)
2257 if (lhs_cell->holder->bi_iter.bi_sector > rhs_cell->holder->bi_iter.bi_sector)
2263 static unsigned int sort_cells(struct pool *pool, struct list_head *cells)
2265 unsigned int count = 0;
2266 struct dm_bio_prison_cell *cell, *tmp;
2268 list_for_each_entry_safe(cell, tmp, cells, user_list) {
2269 if (count >= CELL_SORT_ARRAY_SIZE)
2272 pool->cell_sort_array[count++] = cell;
2273 list_del(&cell->user_list);
2276 sort(pool->cell_sort_array, count, sizeof(cell), cmp_cells, NULL);
2281 static void process_thin_deferred_cells(struct thin_c *tc)
2283 struct pool *pool = tc->pool;
2284 struct list_head cells;
2285 struct dm_bio_prison_cell *cell;
2286 unsigned int i, j, count;
2288 INIT_LIST_HEAD(&cells);
2290 spin_lock_irq(&tc->lock);
2291 list_splice_init(&tc->deferred_cells, &cells);
2292 spin_unlock_irq(&tc->lock);
2294 if (list_empty(&cells))
2298 count = sort_cells(tc->pool, &cells);
2300 for (i = 0; i < count; i++) {
2301 cell = pool->cell_sort_array[i];
2302 BUG_ON(!cell->holder);
2305 * If we've got no free new_mapping structs, and processing
2306 * this bio might require one, we pause until there are some
2307 * prepared mappings to process.
2309 if (ensure_next_mapping(pool)) {
2310 for (j = i; j < count; j++)
2311 list_add(&pool->cell_sort_array[j]->user_list, &cells);
2313 spin_lock_irq(&tc->lock);
2314 list_splice(&cells, &tc->deferred_cells);
2315 spin_unlock_irq(&tc->lock);
2319 if (bio_op(cell->holder) == REQ_OP_DISCARD)
2320 pool->process_discard_cell(tc, cell);
2322 pool->process_cell(tc, cell);
2325 } while (!list_empty(&cells));
2328 static void thin_get(struct thin_c *tc);
2329 static void thin_put(struct thin_c *tc);
2332 * We can't hold rcu_read_lock() around code that can block. So we
2333 * find a thin with the rcu lock held; bump a refcount; then drop
2336 static struct thin_c *get_first_thin(struct pool *pool)
2338 struct thin_c *tc = NULL;
2341 if (!list_empty(&pool->active_thins)) {
2342 tc = list_entry_rcu(pool->active_thins.next, struct thin_c, list);
2350 static struct thin_c *get_next_thin(struct pool *pool, struct thin_c *tc)
2352 struct thin_c *old_tc = tc;
2355 list_for_each_entry_continue_rcu(tc, &pool->active_thins, list) {
2367 static void process_deferred_bios(struct pool *pool)
2370 struct bio_list bios, bio_completions;
2373 tc = get_first_thin(pool);
2375 process_thin_deferred_cells(tc);
2376 process_thin_deferred_bios(tc);
2377 tc = get_next_thin(pool, tc);
2381 * If there are any deferred flush bios, we must commit the metadata
2382 * before issuing them or signaling their completion.
2384 bio_list_init(&bios);
2385 bio_list_init(&bio_completions);
2387 spin_lock_irq(&pool->lock);
2388 bio_list_merge(&bios, &pool->deferred_flush_bios);
2389 bio_list_init(&pool->deferred_flush_bios);
2391 bio_list_merge(&bio_completions, &pool->deferred_flush_completions);
2392 bio_list_init(&pool->deferred_flush_completions);
2393 spin_unlock_irq(&pool->lock);
2395 if (bio_list_empty(&bios) && bio_list_empty(&bio_completions) &&
2396 !(dm_pool_changed_this_transaction(pool->pmd) && need_commit_due_to_time(pool)))
2400 bio_list_merge(&bios, &bio_completions);
2402 while ((bio = bio_list_pop(&bios)))
2406 pool->last_commit_jiffies = jiffies;
2408 while ((bio = bio_list_pop(&bio_completions)))
2411 while ((bio = bio_list_pop(&bios))) {
2413 * The data device was flushed as part of metadata commit,
2414 * so complete redundant flushes immediately.
2416 if (bio->bi_opf & REQ_PREFLUSH)
2419 dm_submit_bio_remap(bio, NULL);
2423 static void do_worker(struct work_struct *ws)
2425 struct pool *pool = container_of(ws, struct pool, worker);
2427 throttle_work_start(&pool->throttle);
2428 dm_pool_issue_prefetches(pool->pmd);
2429 throttle_work_update(&pool->throttle);
2430 process_prepared(pool, &pool->prepared_mappings, &pool->process_prepared_mapping);
2431 throttle_work_update(&pool->throttle);
2432 process_prepared(pool, &pool->prepared_discards, &pool->process_prepared_discard);
2433 throttle_work_update(&pool->throttle);
2434 process_prepared(pool, &pool->prepared_discards_pt2, &pool->process_prepared_discard_pt2);
2435 throttle_work_update(&pool->throttle);
2436 process_deferred_bios(pool);
2437 throttle_work_complete(&pool->throttle);
2441 * We want to commit periodically so that not too much
2442 * unwritten data builds up.
2444 static void do_waker(struct work_struct *ws)
2446 struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker);
2449 queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD);
2453 * We're holding onto IO to allow userland time to react. After the
2454 * timeout either the pool will have been resized (and thus back in
2455 * PM_WRITE mode), or we degrade to PM_OUT_OF_DATA_SPACE w/ error_if_no_space.
2457 static void do_no_space_timeout(struct work_struct *ws)
2459 struct pool *pool = container_of(to_delayed_work(ws), struct pool,
2462 if (get_pool_mode(pool) == PM_OUT_OF_DATA_SPACE && !pool->pf.error_if_no_space) {
2463 pool->pf.error_if_no_space = true;
2464 notify_of_pool_mode_change(pool);
2465 error_retry_list_with_code(pool, BLK_STS_NOSPC);
2469 /*----------------------------------------------------------------*/
2472 struct work_struct worker;
2473 struct completion complete;
2476 static struct pool_work *to_pool_work(struct work_struct *ws)
2478 return container_of(ws, struct pool_work, worker);
2481 static void pool_work_complete(struct pool_work *pw)
2483 complete(&pw->complete);
2486 static void pool_work_wait(struct pool_work *pw, struct pool *pool,
2487 void (*fn)(struct work_struct *))
2489 INIT_WORK_ONSTACK(&pw->worker, fn);
2490 init_completion(&pw->complete);
2491 queue_work(pool->wq, &pw->worker);
2492 wait_for_completion(&pw->complete);
2495 /*----------------------------------------------------------------*/
2497 struct noflush_work {
2498 struct pool_work pw;
2502 static struct noflush_work *to_noflush(struct work_struct *ws)
2504 return container_of(to_pool_work(ws), struct noflush_work, pw);
2507 static void do_noflush_start(struct work_struct *ws)
2509 struct noflush_work *w = to_noflush(ws);
2511 w->tc->requeue_mode = true;
2513 pool_work_complete(&w->pw);
2516 static void do_noflush_stop(struct work_struct *ws)
2518 struct noflush_work *w = to_noflush(ws);
2520 w->tc->requeue_mode = false;
2521 pool_work_complete(&w->pw);
2524 static void noflush_work(struct thin_c *tc, void (*fn)(struct work_struct *))
2526 struct noflush_work w;
2529 pool_work_wait(&w.pw, tc->pool, fn);
2532 /*----------------------------------------------------------------*/
2534 static void set_discard_callbacks(struct pool *pool)
2536 struct pool_c *pt = pool->ti->private;
2538 if (pt->adjusted_pf.discard_passdown) {
2539 pool->process_discard_cell = process_discard_cell_passdown;
2540 pool->process_prepared_discard = process_prepared_discard_passdown_pt1;
2541 pool->process_prepared_discard_pt2 = process_prepared_discard_passdown_pt2;
2543 pool->process_discard_cell = process_discard_cell_no_passdown;
2544 pool->process_prepared_discard = process_prepared_discard_no_passdown;
2548 static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
2550 struct pool_c *pt = pool->ti->private;
2551 bool needs_check = dm_pool_metadata_needs_check(pool->pmd);
2552 enum pool_mode old_mode = get_pool_mode(pool);
2553 unsigned long no_space_timeout = READ_ONCE(no_space_timeout_secs) * HZ;
2556 * Never allow the pool to transition to PM_WRITE mode if user
2557 * intervention is required to verify metadata and data consistency.
2559 if (new_mode == PM_WRITE && needs_check) {
2560 DMERR("%s: unable to switch pool to write mode until repaired.",
2561 dm_device_name(pool->pool_md));
2562 if (old_mode != new_mode)
2563 new_mode = old_mode;
2565 new_mode = PM_READ_ONLY;
2568 * If we were in PM_FAIL mode, rollback of metadata failed. We're
2569 * not going to recover without a thin_repair. So we never let the
2570 * pool move out of the old mode.
2572 if (old_mode == PM_FAIL)
2573 new_mode = old_mode;
2577 dm_pool_metadata_read_only(pool->pmd);
2578 pool->process_bio = process_bio_fail;
2579 pool->process_discard = process_bio_fail;
2580 pool->process_cell = process_cell_fail;
2581 pool->process_discard_cell = process_cell_fail;
2582 pool->process_prepared_mapping = process_prepared_mapping_fail;
2583 pool->process_prepared_discard = process_prepared_discard_fail;
2585 error_retry_list(pool);
2588 case PM_OUT_OF_METADATA_SPACE:
2590 dm_pool_metadata_read_only(pool->pmd);
2591 pool->process_bio = process_bio_read_only;
2592 pool->process_discard = process_bio_success;
2593 pool->process_cell = process_cell_read_only;
2594 pool->process_discard_cell = process_cell_success;
2595 pool->process_prepared_mapping = process_prepared_mapping_fail;
2596 pool->process_prepared_discard = process_prepared_discard_success;
2598 error_retry_list(pool);
2601 case PM_OUT_OF_DATA_SPACE:
2603 * Ideally we'd never hit this state; the low water mark
2604 * would trigger userland to extend the pool before we
2605 * completely run out of data space. However, many small
2606 * IOs to unprovisioned space can consume data space at an
2607 * alarming rate. Adjust your low water mark if you're
2608 * frequently seeing this mode.
2610 pool->out_of_data_space = true;
2611 pool->process_bio = process_bio_read_only;
2612 pool->process_discard = process_discard_bio;
2613 pool->process_cell = process_cell_read_only;
2614 pool->process_prepared_mapping = process_prepared_mapping;
2615 set_discard_callbacks(pool);
2617 if (!pool->pf.error_if_no_space && no_space_timeout)
2618 queue_delayed_work(pool->wq, &pool->no_space_timeout, no_space_timeout);
2622 if (old_mode == PM_OUT_OF_DATA_SPACE)
2623 cancel_delayed_work_sync(&pool->no_space_timeout);
2624 pool->out_of_data_space = false;
2625 pool->pf.error_if_no_space = pt->requested_pf.error_if_no_space;
2626 dm_pool_metadata_read_write(pool->pmd);
2627 pool->process_bio = process_bio;
2628 pool->process_discard = process_discard_bio;
2629 pool->process_cell = process_cell;
2630 pool->process_prepared_mapping = process_prepared_mapping;
2631 set_discard_callbacks(pool);
2635 pool->pf.mode = new_mode;
2637 * The pool mode may have changed, sync it so bind_control_target()
2638 * doesn't cause an unexpected mode transition on resume.
2640 pt->adjusted_pf.mode = new_mode;
2642 if (old_mode != new_mode)
2643 notify_of_pool_mode_change(pool);
2646 static void abort_transaction(struct pool *pool)
2648 const char *dev_name = dm_device_name(pool->pool_md);
2650 DMERR_LIMIT("%s: aborting current metadata transaction", dev_name);
2651 if (dm_pool_abort_metadata(pool->pmd)) {
2652 DMERR("%s: failed to abort metadata transaction", dev_name);
2653 set_pool_mode(pool, PM_FAIL);
2656 if (dm_pool_metadata_set_needs_check(pool->pmd)) {
2657 DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name);
2658 set_pool_mode(pool, PM_FAIL);
2662 static void metadata_operation_failed(struct pool *pool, const char *op, int r)
2664 DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d",
2665 dm_device_name(pool->pool_md), op, r);
2667 abort_transaction(pool);
2668 set_pool_mode(pool, PM_READ_ONLY);
2671 /*----------------------------------------------------------------*/
2674 * Mapping functions.
2678 * Called only while mapping a thin bio to hand it over to the workqueue.
2680 static void thin_defer_bio(struct thin_c *tc, struct bio *bio)
2682 struct pool *pool = tc->pool;
2684 spin_lock_irq(&tc->lock);
2685 bio_list_add(&tc->deferred_bio_list, bio);
2686 spin_unlock_irq(&tc->lock);
2691 static void thin_defer_bio_with_throttle(struct thin_c *tc, struct bio *bio)
2693 struct pool *pool = tc->pool;
2695 throttle_lock(&pool->throttle);
2696 thin_defer_bio(tc, bio);
2697 throttle_unlock(&pool->throttle);
2700 static void thin_defer_cell(struct thin_c *tc, struct dm_bio_prison_cell *cell)
2702 struct pool *pool = tc->pool;
2704 throttle_lock(&pool->throttle);
2705 spin_lock_irq(&tc->lock);
2706 list_add_tail(&cell->user_list, &tc->deferred_cells);
2707 spin_unlock_irq(&tc->lock);
2708 throttle_unlock(&pool->throttle);
2713 static void thin_hook_bio(struct thin_c *tc, struct bio *bio)
2715 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
2718 h->shared_read_entry = NULL;
2719 h->all_io_entry = NULL;
2720 h->overwrite_mapping = NULL;
2725 * Non-blocking function called from the thin target's map function.
2727 static int thin_bio_map(struct dm_target *ti, struct bio *bio)
2730 struct thin_c *tc = ti->private;
2731 dm_block_t block = get_bio_block(tc, bio);
2732 struct dm_thin_device *td = tc->td;
2733 struct dm_thin_lookup_result result;
2734 struct dm_bio_prison_cell *virt_cell, *data_cell;
2735 struct dm_cell_key key;
2737 thin_hook_bio(tc, bio);
2739 if (tc->requeue_mode) {
2740 bio->bi_status = BLK_STS_DM_REQUEUE;
2742 return DM_MAPIO_SUBMITTED;
2745 if (get_pool_mode(tc->pool) == PM_FAIL) {
2747 return DM_MAPIO_SUBMITTED;
2750 if (op_is_flush(bio->bi_opf) || bio_op(bio) == REQ_OP_DISCARD) {
2751 thin_defer_bio_with_throttle(tc, bio);
2752 return DM_MAPIO_SUBMITTED;
2756 * We must hold the virtual cell before doing the lookup, otherwise
2757 * there's a race with discard.
2759 build_virtual_key(tc->td, block, &key);
2760 if (bio_detain(tc->pool, &key, bio, &virt_cell))
2761 return DM_MAPIO_SUBMITTED;
2763 r = dm_thin_find_block(td, block, 0, &result);
2766 * Note that we defer readahead too.
2770 if (unlikely(result.shared)) {
2772 * We have a race condition here between the
2773 * result.shared value returned by the lookup and
2774 * snapshot creation, which may cause new
2777 * To avoid this always quiesce the origin before
2778 * taking the snap. You want to do this anyway to
2779 * ensure a consistent application view
2782 * More distant ancestors are irrelevant. The
2783 * shared flag will be set in their case.
2785 thin_defer_cell(tc, virt_cell);
2786 return DM_MAPIO_SUBMITTED;
2789 build_data_key(tc->td, result.block, &key);
2790 if (bio_detain(tc->pool, &key, bio, &data_cell)) {
2791 cell_defer_no_holder(tc, virt_cell);
2792 return DM_MAPIO_SUBMITTED;
2795 inc_all_io_entry(tc->pool, bio);
2796 cell_defer_no_holder(tc, data_cell);
2797 cell_defer_no_holder(tc, virt_cell);
2799 remap(tc, bio, result.block);
2800 return DM_MAPIO_REMAPPED;
2804 thin_defer_cell(tc, virt_cell);
2805 return DM_MAPIO_SUBMITTED;
2809 * Must always call bio_io_error on failure.
2810 * dm_thin_find_block can fail with -EINVAL if the
2811 * pool is switched to fail-io mode.
2814 cell_defer_no_holder(tc, virt_cell);
2815 return DM_MAPIO_SUBMITTED;
2819 static void requeue_bios(struct pool *pool)
2824 list_for_each_entry_rcu(tc, &pool->active_thins, list) {
2825 spin_lock_irq(&tc->lock);
2826 bio_list_merge(&tc->deferred_bio_list, &tc->retry_on_resume_list);
2827 bio_list_init(&tc->retry_on_resume_list);
2828 spin_unlock_irq(&tc->lock);
2834 *--------------------------------------------------------------
2835 * Binding of control targets to a pool object
2836 *--------------------------------------------------------------
2838 static bool is_factor(sector_t block_size, uint32_t n)
2840 return !sector_div(block_size, n);
2844 * If discard_passdown was enabled verify that the data device
2845 * supports discards. Disable discard_passdown if not.
2847 static void disable_discard_passdown_if_not_supported(struct pool_c *pt)
2849 struct pool *pool = pt->pool;
2850 struct block_device *data_bdev = pt->data_dev->bdev;
2851 struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits;
2852 const char *reason = NULL;
2854 if (!pt->adjusted_pf.discard_passdown)
2857 if (!bdev_max_discard_sectors(pt->data_dev->bdev))
2858 reason = "discard unsupported";
2860 else if (data_limits->max_discard_sectors < pool->sectors_per_block)
2861 reason = "max discard sectors smaller than a block";
2864 DMWARN("Data device (%pg) %s: Disabling discard passdown.", data_bdev, reason);
2865 pt->adjusted_pf.discard_passdown = false;
2869 static int bind_control_target(struct pool *pool, struct dm_target *ti)
2871 struct pool_c *pt = ti->private;
2874 * We want to make sure that a pool in PM_FAIL mode is never upgraded.
2876 enum pool_mode old_mode = get_pool_mode(pool);
2877 enum pool_mode new_mode = pt->adjusted_pf.mode;
2880 * Don't change the pool's mode until set_pool_mode() below.
2881 * Otherwise the pool's process_* function pointers may
2882 * not match the desired pool mode.
2884 pt->adjusted_pf.mode = old_mode;
2887 pool->pf = pt->adjusted_pf;
2888 pool->low_water_blocks = pt->low_water_blocks;
2890 set_pool_mode(pool, new_mode);
2895 static void unbind_control_target(struct pool *pool, struct dm_target *ti)
2902 *--------------------------------------------------------------
2904 *--------------------------------------------------------------
2906 /* Initialize pool features. */
2907 static void pool_features_init(struct pool_features *pf)
2909 pf->mode = PM_WRITE;
2910 pf->zero_new_blocks = true;
2911 pf->discard_enabled = true;
2912 pf->discard_passdown = true;
2913 pf->error_if_no_space = false;
2916 static void __pool_destroy(struct pool *pool)
2918 __pool_table_remove(pool);
2920 vfree(pool->cell_sort_array);
2921 if (dm_pool_metadata_close(pool->pmd) < 0)
2922 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
2924 dm_bio_prison_destroy(pool->prison);
2925 dm_kcopyd_client_destroy(pool->copier);
2927 cancel_delayed_work_sync(&pool->waker);
2928 cancel_delayed_work_sync(&pool->no_space_timeout);
2930 destroy_workqueue(pool->wq);
2932 if (pool->next_mapping)
2933 mempool_free(pool->next_mapping, &pool->mapping_pool);
2934 mempool_exit(&pool->mapping_pool);
2935 dm_deferred_set_destroy(pool->shared_read_ds);
2936 dm_deferred_set_destroy(pool->all_io_ds);
2940 static struct kmem_cache *_new_mapping_cache;
2942 static struct pool *pool_create(struct mapped_device *pool_md,
2943 struct block_device *metadata_dev,
2944 struct block_device *data_dev,
2945 unsigned long block_size,
2946 int read_only, char **error)
2951 struct dm_pool_metadata *pmd;
2952 bool format_device = read_only ? false : true;
2954 pmd = dm_pool_metadata_open(metadata_dev, block_size, format_device);
2956 *error = "Error creating metadata object";
2957 return (struct pool *)pmd;
2960 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
2962 *error = "Error allocating memory for pool";
2963 err_p = ERR_PTR(-ENOMEM);
2968 pool->sectors_per_block = block_size;
2969 if (block_size & (block_size - 1))
2970 pool->sectors_per_block_shift = -1;
2972 pool->sectors_per_block_shift = __ffs(block_size);
2973 pool->low_water_blocks = 0;
2974 pool_features_init(&pool->pf);
2975 pool->prison = dm_bio_prison_create();
2976 if (!pool->prison) {
2977 *error = "Error creating pool's bio prison";
2978 err_p = ERR_PTR(-ENOMEM);
2982 pool->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle);
2983 if (IS_ERR(pool->copier)) {
2984 r = PTR_ERR(pool->copier);
2985 *error = "Error creating pool's kcopyd client";
2987 goto bad_kcopyd_client;
2991 * Create singlethreaded workqueue that will service all devices
2992 * that use this metadata.
2994 pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
2996 *error = "Error creating pool's workqueue";
2997 err_p = ERR_PTR(-ENOMEM);
3001 throttle_init(&pool->throttle);
3002 INIT_WORK(&pool->worker, do_worker);
3003 INIT_DELAYED_WORK(&pool->waker, do_waker);
3004 INIT_DELAYED_WORK(&pool->no_space_timeout, do_no_space_timeout);
3005 spin_lock_init(&pool->lock);
3006 bio_list_init(&pool->deferred_flush_bios);
3007 bio_list_init(&pool->deferred_flush_completions);
3008 INIT_LIST_HEAD(&pool->prepared_mappings);
3009 INIT_LIST_HEAD(&pool->prepared_discards);
3010 INIT_LIST_HEAD(&pool->prepared_discards_pt2);
3011 INIT_LIST_HEAD(&pool->active_thins);
3012 pool->low_water_triggered = false;
3013 pool->suspended = true;
3014 pool->out_of_data_space = false;
3016 pool->shared_read_ds = dm_deferred_set_create();
3017 if (!pool->shared_read_ds) {
3018 *error = "Error creating pool's shared read deferred set";
3019 err_p = ERR_PTR(-ENOMEM);
3020 goto bad_shared_read_ds;
3023 pool->all_io_ds = dm_deferred_set_create();
3024 if (!pool->all_io_ds) {
3025 *error = "Error creating pool's all io deferred set";
3026 err_p = ERR_PTR(-ENOMEM);
3030 pool->next_mapping = NULL;
3031 r = mempool_init_slab_pool(&pool->mapping_pool, MAPPING_POOL_SIZE,
3032 _new_mapping_cache);
3034 *error = "Error creating pool's mapping mempool";
3036 goto bad_mapping_pool;
3039 pool->cell_sort_array =
3040 vmalloc(array_size(CELL_SORT_ARRAY_SIZE,
3041 sizeof(*pool->cell_sort_array)));
3042 if (!pool->cell_sort_array) {
3043 *error = "Error allocating cell sort array";
3044 err_p = ERR_PTR(-ENOMEM);
3045 goto bad_sort_array;
3048 pool->ref_count = 1;
3049 pool->last_commit_jiffies = jiffies;
3050 pool->pool_md = pool_md;
3051 pool->md_dev = metadata_dev;
3052 pool->data_dev = data_dev;
3053 __pool_table_insert(pool);
3058 mempool_exit(&pool->mapping_pool);
3060 dm_deferred_set_destroy(pool->all_io_ds);
3062 dm_deferred_set_destroy(pool->shared_read_ds);
3064 destroy_workqueue(pool->wq);
3066 dm_kcopyd_client_destroy(pool->copier);
3068 dm_bio_prison_destroy(pool->prison);
3072 if (dm_pool_metadata_close(pmd))
3073 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
3078 static void __pool_inc(struct pool *pool)
3080 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
3084 static void __pool_dec(struct pool *pool)
3086 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
3087 BUG_ON(!pool->ref_count);
3088 if (!--pool->ref_count)
3089 __pool_destroy(pool);
3092 static struct pool *__pool_find(struct mapped_device *pool_md,
3093 struct block_device *metadata_dev,
3094 struct block_device *data_dev,
3095 unsigned long block_size, int read_only,
3096 char **error, int *created)
3098 struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev);
3101 if (pool->pool_md != pool_md) {
3102 *error = "metadata device already in use by a pool";
3103 return ERR_PTR(-EBUSY);
3105 if (pool->data_dev != data_dev) {
3106 *error = "data device already in use by a pool";
3107 return ERR_PTR(-EBUSY);
3112 pool = __pool_table_lookup(pool_md);
3114 if (pool->md_dev != metadata_dev || pool->data_dev != data_dev) {
3115 *error = "different pool cannot replace a pool";
3116 return ERR_PTR(-EINVAL);
3121 pool = pool_create(pool_md, metadata_dev, data_dev, block_size, read_only, error);
3130 *--------------------------------------------------------------
3131 * Pool target methods
3132 *--------------------------------------------------------------
3134 static void pool_dtr(struct dm_target *ti)
3136 struct pool_c *pt = ti->private;
3138 mutex_lock(&dm_thin_pool_table.mutex);
3140 unbind_control_target(pt->pool, ti);
3141 __pool_dec(pt->pool);
3142 dm_put_device(ti, pt->metadata_dev);
3143 dm_put_device(ti, pt->data_dev);
3146 mutex_unlock(&dm_thin_pool_table.mutex);
3149 static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf,
3150 struct dm_target *ti)
3154 const char *arg_name;
3156 static const struct dm_arg _args[] = {
3157 {0, 4, "Invalid number of pool feature arguments"},
3161 * No feature arguments supplied.
3166 r = dm_read_arg_group(_args, as, &argc, &ti->error);
3170 while (argc && !r) {
3171 arg_name = dm_shift_arg(as);
3174 if (!strcasecmp(arg_name, "skip_block_zeroing"))
3175 pf->zero_new_blocks = false;
3177 else if (!strcasecmp(arg_name, "ignore_discard"))
3178 pf->discard_enabled = false;
3180 else if (!strcasecmp(arg_name, "no_discard_passdown"))
3181 pf->discard_passdown = false;
3183 else if (!strcasecmp(arg_name, "read_only"))
3184 pf->mode = PM_READ_ONLY;
3186 else if (!strcasecmp(arg_name, "error_if_no_space"))
3187 pf->error_if_no_space = true;
3190 ti->error = "Unrecognised pool feature requested";
3199 static void metadata_low_callback(void *context)
3201 struct pool *pool = context;
3203 DMWARN("%s: reached low water mark for metadata device: sending event.",
3204 dm_device_name(pool->pool_md));
3206 dm_table_event(pool->ti->table);
3210 * We need to flush the data device **before** committing the metadata.
3212 * This ensures that the data blocks of any newly inserted mappings are
3213 * properly written to non-volatile storage and won't be lost in case of a
3216 * Failure to do so can result in data corruption in the case of internal or
3217 * external snapshots and in the case of newly provisioned blocks, when block
3218 * zeroing is enabled.
3220 static int metadata_pre_commit_callback(void *context)
3222 struct pool *pool = context;
3224 return blkdev_issue_flush(pool->data_dev);
3227 static sector_t get_dev_size(struct block_device *bdev)
3229 return bdev_nr_sectors(bdev);
3232 static void warn_if_metadata_device_too_big(struct block_device *bdev)
3234 sector_t metadata_dev_size = get_dev_size(bdev);
3236 if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING)
3237 DMWARN("Metadata device %pg is larger than %u sectors: excess space will not be used.",
3238 bdev, THIN_METADATA_MAX_SECTORS);
3241 static sector_t get_metadata_dev_size(struct block_device *bdev)
3243 sector_t metadata_dev_size = get_dev_size(bdev);
3245 if (metadata_dev_size > THIN_METADATA_MAX_SECTORS)
3246 metadata_dev_size = THIN_METADATA_MAX_SECTORS;
3248 return metadata_dev_size;
3251 static dm_block_t get_metadata_dev_size_in_blocks(struct block_device *bdev)
3253 sector_t metadata_dev_size = get_metadata_dev_size(bdev);
3255 sector_div(metadata_dev_size, THIN_METADATA_BLOCK_SIZE);
3257 return metadata_dev_size;
3261 * When a metadata threshold is crossed a dm event is triggered, and
3262 * userland should respond by growing the metadata device. We could let
3263 * userland set the threshold, like we do with the data threshold, but I'm
3264 * not sure they know enough to do this well.
3266 static dm_block_t calc_metadata_threshold(struct pool_c *pt)
3269 * 4M is ample for all ops with the possible exception of thin
3270 * device deletion which is harmless if it fails (just retry the
3271 * delete after you've grown the device).
3273 dm_block_t quarter = get_metadata_dev_size_in_blocks(pt->metadata_dev->bdev) / 4;
3275 return min((dm_block_t)1024ULL /* 4M */, quarter);
3279 * thin-pool <metadata dev> <data dev>
3280 * <data block size (sectors)>
3281 * <low water mark (blocks)>
3282 * [<#feature args> [<arg>]*]
3284 * Optional feature arguments are:
3285 * skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
3286 * ignore_discard: disable discard
3287 * no_discard_passdown: don't pass discards down to the data device
3288 * read_only: Don't allow any changes to be made to the pool metadata.
3289 * error_if_no_space: error IOs, instead of queueing, if no space.
3291 static int pool_ctr(struct dm_target *ti, unsigned int argc, char **argv)
3293 int r, pool_created = 0;
3296 struct pool_features pf;
3297 struct dm_arg_set as;
3298 struct dm_dev *data_dev;
3299 unsigned long block_size;
3300 dm_block_t low_water_blocks;
3301 struct dm_dev *metadata_dev;
3302 blk_mode_t metadata_mode;
3305 * FIXME Remove validation from scope of lock.
3307 mutex_lock(&dm_thin_pool_table.mutex);
3310 ti->error = "Invalid argument count";
3318 /* make sure metadata and data are different devices */
3319 if (!strcmp(argv[0], argv[1])) {
3320 ti->error = "Error setting metadata or data device";
3326 * Set default pool features.
3328 pool_features_init(&pf);
3330 dm_consume_args(&as, 4);
3331 r = parse_pool_features(&as, &pf, ti);
3335 metadata_mode = BLK_OPEN_READ |
3336 ((pf.mode == PM_READ_ONLY) ? 0 : BLK_OPEN_WRITE);
3337 r = dm_get_device(ti, argv[0], metadata_mode, &metadata_dev);
3339 ti->error = "Error opening metadata block device";
3342 warn_if_metadata_device_too_big(metadata_dev->bdev);
3344 r = dm_get_device(ti, argv[1], BLK_OPEN_READ | BLK_OPEN_WRITE, &data_dev);
3346 ti->error = "Error getting data device";
3350 if (kstrtoul(argv[2], 10, &block_size) || !block_size ||
3351 block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
3352 block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
3353 block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
3354 ti->error = "Invalid block size";
3359 if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) {
3360 ti->error = "Invalid low water mark";
3365 pt = kzalloc(sizeof(*pt), GFP_KERNEL);
3371 pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev, data_dev->bdev,
3372 block_size, pf.mode == PM_READ_ONLY, &ti->error, &pool_created);
3379 * 'pool_created' reflects whether this is the first table load.
3380 * Top level discard support is not allowed to be changed after
3381 * initial load. This would require a pool reload to trigger thin
3384 if (!pool_created && pf.discard_enabled != pool->pf.discard_enabled) {
3385 ti->error = "Discard support cannot be disabled once enabled";
3387 goto out_flags_changed;
3392 pt->metadata_dev = metadata_dev;
3393 pt->data_dev = data_dev;
3394 pt->low_water_blocks = low_water_blocks;
3395 pt->adjusted_pf = pt->requested_pf = pf;
3396 ti->num_flush_bios = 1;
3397 ti->limit_swap_bios = true;
3400 * Only need to enable discards if the pool should pass
3401 * them down to the data device. The thin device's discard
3402 * processing will cause mappings to be removed from the btree.
3404 if (pf.discard_enabled && pf.discard_passdown) {
3405 ti->num_discard_bios = 1;
3407 * Setting 'discards_supported' circumvents the normal
3408 * stacking of discard limits (this keeps the pool and
3409 * thin devices' discard limits consistent).
3411 ti->discards_supported = true;
3412 ti->max_discard_granularity = true;
3416 r = dm_pool_register_metadata_threshold(pt->pool->pmd,
3417 calc_metadata_threshold(pt),
3418 metadata_low_callback,
3421 ti->error = "Error registering metadata threshold";
3422 goto out_flags_changed;
3425 dm_pool_register_pre_commit_callback(pool->pmd,
3426 metadata_pre_commit_callback, pool);
3428 mutex_unlock(&dm_thin_pool_table.mutex);
3437 dm_put_device(ti, data_dev);
3439 dm_put_device(ti, metadata_dev);
3441 mutex_unlock(&dm_thin_pool_table.mutex);
3446 static int pool_map(struct dm_target *ti, struct bio *bio)
3448 struct pool_c *pt = ti->private;
3449 struct pool *pool = pt->pool;
3452 * As this is a singleton target, ti->begin is always zero.
3454 spin_lock_irq(&pool->lock);
3455 bio_set_dev(bio, pt->data_dev->bdev);
3456 spin_unlock_irq(&pool->lock);
3458 return DM_MAPIO_REMAPPED;
3461 static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit)
3464 struct pool_c *pt = ti->private;
3465 struct pool *pool = pt->pool;
3466 sector_t data_size = ti->len;
3467 dm_block_t sb_data_size;
3469 *need_commit = false;
3471 (void) sector_div(data_size, pool->sectors_per_block);
3473 r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
3475 DMERR("%s: failed to retrieve data device size",
3476 dm_device_name(pool->pool_md));
3480 if (data_size < sb_data_size) {
3481 DMERR("%s: pool target (%llu blocks) too small: expected %llu",
3482 dm_device_name(pool->pool_md),
3483 (unsigned long long)data_size, sb_data_size);
3486 } else if (data_size > sb_data_size) {
3487 if (dm_pool_metadata_needs_check(pool->pmd)) {
3488 DMERR("%s: unable to grow the data device until repaired.",
3489 dm_device_name(pool->pool_md));
3494 DMINFO("%s: growing the data device from %llu to %llu blocks",
3495 dm_device_name(pool->pool_md),
3496 sb_data_size, (unsigned long long)data_size);
3497 r = dm_pool_resize_data_dev(pool->pmd, data_size);
3499 metadata_operation_failed(pool, "dm_pool_resize_data_dev", r);
3503 *need_commit = true;
3509 static int maybe_resize_metadata_dev(struct dm_target *ti, bool *need_commit)
3512 struct pool_c *pt = ti->private;
3513 struct pool *pool = pt->pool;
3514 dm_block_t metadata_dev_size, sb_metadata_dev_size;
3516 *need_commit = false;
3518 metadata_dev_size = get_metadata_dev_size_in_blocks(pool->md_dev);
3520 r = dm_pool_get_metadata_dev_size(pool->pmd, &sb_metadata_dev_size);
3522 DMERR("%s: failed to retrieve metadata device size",
3523 dm_device_name(pool->pool_md));
3527 if (metadata_dev_size < sb_metadata_dev_size) {
3528 DMERR("%s: metadata device (%llu blocks) too small: expected %llu",
3529 dm_device_name(pool->pool_md),
3530 metadata_dev_size, sb_metadata_dev_size);
3533 } else if (metadata_dev_size > sb_metadata_dev_size) {
3534 if (dm_pool_metadata_needs_check(pool->pmd)) {
3535 DMERR("%s: unable to grow the metadata device until repaired.",
3536 dm_device_name(pool->pool_md));
3540 warn_if_metadata_device_too_big(pool->md_dev);
3541 DMINFO("%s: growing the metadata device from %llu to %llu blocks",
3542 dm_device_name(pool->pool_md),
3543 sb_metadata_dev_size, metadata_dev_size);
3545 if (get_pool_mode(pool) == PM_OUT_OF_METADATA_SPACE)
3546 set_pool_mode(pool, PM_WRITE);
3548 r = dm_pool_resize_metadata_dev(pool->pmd, metadata_dev_size);
3550 metadata_operation_failed(pool, "dm_pool_resize_metadata_dev", r);
3554 *need_commit = true;
3561 * Retrieves the number of blocks of the data device from
3562 * the superblock and compares it to the actual device size,
3563 * thus resizing the data device in case it has grown.
3565 * This both copes with opening preallocated data devices in the ctr
3566 * being followed by a resume
3568 * calling the resume method individually after userspace has
3569 * grown the data device in reaction to a table event.
3571 static int pool_preresume(struct dm_target *ti)
3574 bool need_commit1, need_commit2;
3575 struct pool_c *pt = ti->private;
3576 struct pool *pool = pt->pool;
3579 * Take control of the pool object.
3581 r = bind_control_target(pool, ti);
3585 r = maybe_resize_data_dev(ti, &need_commit1);
3589 r = maybe_resize_metadata_dev(ti, &need_commit2);
3593 if (need_commit1 || need_commit2)
3594 (void) commit(pool);
3597 * When a thin-pool is PM_FAIL, it cannot be rebuilt if
3598 * bio is in deferred list. Therefore need to return 0
3599 * to allow pool_resume() to flush IO.
3601 if (r && get_pool_mode(pool) == PM_FAIL)
3607 static void pool_suspend_active_thins(struct pool *pool)
3611 /* Suspend all active thin devices */
3612 tc = get_first_thin(pool);
3614 dm_internal_suspend_noflush(tc->thin_md);
3615 tc = get_next_thin(pool, tc);
3619 static void pool_resume_active_thins(struct pool *pool)
3623 /* Resume all active thin devices */
3624 tc = get_first_thin(pool);
3626 dm_internal_resume(tc->thin_md);
3627 tc = get_next_thin(pool, tc);
3631 static void pool_resume(struct dm_target *ti)
3633 struct pool_c *pt = ti->private;
3634 struct pool *pool = pt->pool;
3637 * Must requeue active_thins' bios and then resume
3638 * active_thins _before_ clearing 'suspend' flag.
3641 pool_resume_active_thins(pool);
3643 spin_lock_irq(&pool->lock);
3644 pool->low_water_triggered = false;
3645 pool->suspended = false;
3646 spin_unlock_irq(&pool->lock);
3648 do_waker(&pool->waker.work);
3651 static void pool_presuspend(struct dm_target *ti)
3653 struct pool_c *pt = ti->private;
3654 struct pool *pool = pt->pool;
3656 spin_lock_irq(&pool->lock);
3657 pool->suspended = true;
3658 spin_unlock_irq(&pool->lock);
3660 pool_suspend_active_thins(pool);
3663 static void pool_presuspend_undo(struct dm_target *ti)
3665 struct pool_c *pt = ti->private;
3666 struct pool *pool = pt->pool;
3668 pool_resume_active_thins(pool);
3670 spin_lock_irq(&pool->lock);
3671 pool->suspended = false;
3672 spin_unlock_irq(&pool->lock);
3675 static void pool_postsuspend(struct dm_target *ti)
3677 struct pool_c *pt = ti->private;
3678 struct pool *pool = pt->pool;
3680 cancel_delayed_work_sync(&pool->waker);
3681 cancel_delayed_work_sync(&pool->no_space_timeout);
3682 flush_workqueue(pool->wq);
3683 (void) commit(pool);
3686 static int check_arg_count(unsigned int argc, unsigned int args_required)
3688 if (argc != args_required) {
3689 DMWARN("Message received with %u arguments instead of %u.",
3690 argc, args_required);
3697 static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning)
3699 if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) &&
3700 *dev_id <= MAX_DEV_ID)
3704 DMWARN("Message received with invalid device id: %s", arg);
3709 static int process_create_thin_mesg(unsigned int argc, char **argv, struct pool *pool)
3714 r = check_arg_count(argc, 2);
3718 r = read_dev_id(argv[1], &dev_id, 1);
3722 r = dm_pool_create_thin(pool->pmd, dev_id);
3724 DMWARN("Creation of new thinly-provisioned device with id %s failed.",
3732 static int process_create_snap_mesg(unsigned int argc, char **argv, struct pool *pool)
3735 dm_thin_id origin_dev_id;
3738 r = check_arg_count(argc, 3);
3742 r = read_dev_id(argv[1], &dev_id, 1);
3746 r = read_dev_id(argv[2], &origin_dev_id, 1);
3750 r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id);
3752 DMWARN("Creation of new snapshot %s of device %s failed.",
3760 static int process_delete_mesg(unsigned int argc, char **argv, struct pool *pool)
3765 r = check_arg_count(argc, 2);
3769 r = read_dev_id(argv[1], &dev_id, 1);
3773 r = dm_pool_delete_thin_device(pool->pmd, dev_id);
3775 DMWARN("Deletion of thin device %s failed.", argv[1]);
3780 static int process_set_transaction_id_mesg(unsigned int argc, char **argv, struct pool *pool)
3782 dm_thin_id old_id, new_id;
3785 r = check_arg_count(argc, 3);
3789 if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) {
3790 DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]);
3794 if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) {
3795 DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]);
3799 r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id);
3801 DMWARN("Failed to change transaction id from %s to %s.",
3809 static int process_reserve_metadata_snap_mesg(unsigned int argc, char **argv, struct pool *pool)
3813 r = check_arg_count(argc, 1);
3817 (void) commit(pool);
3819 r = dm_pool_reserve_metadata_snap(pool->pmd);
3821 DMWARN("reserve_metadata_snap message failed.");
3826 static int process_release_metadata_snap_mesg(unsigned int argc, char **argv, struct pool *pool)
3830 r = check_arg_count(argc, 1);
3834 r = dm_pool_release_metadata_snap(pool->pmd);
3836 DMWARN("release_metadata_snap message failed.");
3842 * Messages supported:
3843 * create_thin <dev_id>
3844 * create_snap <dev_id> <origin_id>
3846 * set_transaction_id <current_trans_id> <new_trans_id>
3847 * reserve_metadata_snap
3848 * release_metadata_snap
3850 static int pool_message(struct dm_target *ti, unsigned int argc, char **argv,
3851 char *result, unsigned int maxlen)
3854 struct pool_c *pt = ti->private;
3855 struct pool *pool = pt->pool;
3857 if (get_pool_mode(pool) >= PM_OUT_OF_METADATA_SPACE) {
3858 DMERR("%s: unable to service pool target messages in READ_ONLY or FAIL mode",
3859 dm_device_name(pool->pool_md));
3863 if (!strcasecmp(argv[0], "create_thin"))
3864 r = process_create_thin_mesg(argc, argv, pool);
3866 else if (!strcasecmp(argv[0], "create_snap"))
3867 r = process_create_snap_mesg(argc, argv, pool);
3869 else if (!strcasecmp(argv[0], "delete"))
3870 r = process_delete_mesg(argc, argv, pool);
3872 else if (!strcasecmp(argv[0], "set_transaction_id"))
3873 r = process_set_transaction_id_mesg(argc, argv, pool);
3875 else if (!strcasecmp(argv[0], "reserve_metadata_snap"))
3876 r = process_reserve_metadata_snap_mesg(argc, argv, pool);
3878 else if (!strcasecmp(argv[0], "release_metadata_snap"))
3879 r = process_release_metadata_snap_mesg(argc, argv, pool);
3882 DMWARN("Unrecognised thin pool target message received: %s", argv[0]);
3885 (void) commit(pool);
3890 static void emit_flags(struct pool_features *pf, char *result,
3891 unsigned int sz, unsigned int maxlen)
3893 unsigned int count = !pf->zero_new_blocks + !pf->discard_enabled +
3894 !pf->discard_passdown + (pf->mode == PM_READ_ONLY) +
3895 pf->error_if_no_space;
3896 DMEMIT("%u ", count);
3898 if (!pf->zero_new_blocks)
3899 DMEMIT("skip_block_zeroing ");
3901 if (!pf->discard_enabled)
3902 DMEMIT("ignore_discard ");
3904 if (!pf->discard_passdown)
3905 DMEMIT("no_discard_passdown ");
3907 if (pf->mode == PM_READ_ONLY)
3908 DMEMIT("read_only ");
3910 if (pf->error_if_no_space)
3911 DMEMIT("error_if_no_space ");
3916 * <transaction id> <used metadata sectors>/<total metadata sectors>
3917 * <used data sectors>/<total data sectors> <held metadata root>
3918 * <pool mode> <discard config> <no space config> <needs_check>
3920 static void pool_status(struct dm_target *ti, status_type_t type,
3921 unsigned int status_flags, char *result, unsigned int maxlen)
3924 unsigned int sz = 0;
3925 uint64_t transaction_id;
3926 dm_block_t nr_free_blocks_data;
3927 dm_block_t nr_free_blocks_metadata;
3928 dm_block_t nr_blocks_data;
3929 dm_block_t nr_blocks_metadata;
3930 dm_block_t held_root;
3931 enum pool_mode mode;
3932 char buf[BDEVNAME_SIZE];
3933 char buf2[BDEVNAME_SIZE];
3934 struct pool_c *pt = ti->private;
3935 struct pool *pool = pt->pool;
3938 case STATUSTYPE_INFO:
3939 if (get_pool_mode(pool) == PM_FAIL) {
3944 /* Commit to ensure statistics aren't out-of-date */
3945 if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
3946 (void) commit(pool);
3948 r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id);
3950 DMERR("%s: dm_pool_get_metadata_transaction_id returned %d",
3951 dm_device_name(pool->pool_md), r);
3955 r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free_blocks_metadata);
3957 DMERR("%s: dm_pool_get_free_metadata_block_count returned %d",
3958 dm_device_name(pool->pool_md), r);
3962 r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
3964 DMERR("%s: dm_pool_get_metadata_dev_size returned %d",
3965 dm_device_name(pool->pool_md), r);
3969 r = dm_pool_get_free_block_count(pool->pmd, &nr_free_blocks_data);
3971 DMERR("%s: dm_pool_get_free_block_count returned %d",
3972 dm_device_name(pool->pool_md), r);
3976 r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
3978 DMERR("%s: dm_pool_get_data_dev_size returned %d",
3979 dm_device_name(pool->pool_md), r);
3983 r = dm_pool_get_metadata_snap(pool->pmd, &held_root);
3985 DMERR("%s: dm_pool_get_metadata_snap returned %d",
3986 dm_device_name(pool->pool_md), r);
3990 DMEMIT("%llu %llu/%llu %llu/%llu ",
3991 (unsigned long long)transaction_id,
3992 (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata),
3993 (unsigned long long)nr_blocks_metadata,
3994 (unsigned long long)(nr_blocks_data - nr_free_blocks_data),
3995 (unsigned long long)nr_blocks_data);
3998 DMEMIT("%llu ", held_root);
4002 mode = get_pool_mode(pool);
4003 if (mode == PM_OUT_OF_DATA_SPACE)
4004 DMEMIT("out_of_data_space ");
4005 else if (is_read_only_pool_mode(mode))
4010 if (!pool->pf.discard_enabled)
4011 DMEMIT("ignore_discard ");
4012 else if (pool->pf.discard_passdown)
4013 DMEMIT("discard_passdown ");
4015 DMEMIT("no_discard_passdown ");
4017 if (pool->pf.error_if_no_space)
4018 DMEMIT("error_if_no_space ");
4020 DMEMIT("queue_if_no_space ");
4022 if (dm_pool_metadata_needs_check(pool->pmd))
4023 DMEMIT("needs_check ");
4027 DMEMIT("%llu ", (unsigned long long)calc_metadata_threshold(pt));
4031 case STATUSTYPE_TABLE:
4032 DMEMIT("%s %s %lu %llu ",
4033 format_dev_t(buf, pt->metadata_dev->bdev->bd_dev),
4034 format_dev_t(buf2, pt->data_dev->bdev->bd_dev),
4035 (unsigned long)pool->sectors_per_block,
4036 (unsigned long long)pt->low_water_blocks);
4037 emit_flags(&pt->requested_pf, result, sz, maxlen);
4040 case STATUSTYPE_IMA:
4050 static int pool_iterate_devices(struct dm_target *ti,
4051 iterate_devices_callout_fn fn, void *data)
4053 struct pool_c *pt = ti->private;
4055 return fn(ti, pt->data_dev, 0, ti->len, data);
4058 static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
4060 struct pool_c *pt = ti->private;
4061 struct pool *pool = pt->pool;
4062 sector_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
4065 * If max_sectors is smaller than pool->sectors_per_block adjust it
4066 * to the highest possible power-of-2 factor of pool->sectors_per_block.
4067 * This is especially beneficial when the pool's data device is a RAID
4068 * device that has a full stripe width that matches pool->sectors_per_block
4069 * -- because even though partial RAID stripe-sized IOs will be issued to a
4070 * single RAID stripe; when aggregated they will end on a full RAID stripe
4071 * boundary.. which avoids additional partial RAID stripe writes cascading
4073 if (limits->max_sectors < pool->sectors_per_block) {
4074 while (!is_factor(pool->sectors_per_block, limits->max_sectors)) {
4075 if ((limits->max_sectors & (limits->max_sectors - 1)) == 0)
4076 limits->max_sectors--;
4077 limits->max_sectors = rounddown_pow_of_two(limits->max_sectors);
4082 * If the system-determined stacked limits are compatible with the
4083 * pool's blocksize (io_opt is a factor) do not override them.
4085 if (io_opt_sectors < pool->sectors_per_block ||
4086 !is_factor(io_opt_sectors, pool->sectors_per_block)) {
4087 if (is_factor(pool->sectors_per_block, limits->max_sectors))
4088 blk_limits_io_min(limits, limits->max_sectors << SECTOR_SHIFT);
4090 blk_limits_io_min(limits, pool->sectors_per_block << SECTOR_SHIFT);
4091 blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
4095 * pt->adjusted_pf is a staging area for the actual features to use.
4096 * They get transferred to the live pool in bind_control_target()
4097 * called from pool_preresume().
4100 if (pt->adjusted_pf.discard_enabled) {
4101 disable_discard_passdown_if_not_supported(pt);
4102 if (!pt->adjusted_pf.discard_passdown)
4103 limits->max_discard_sectors = 0;
4105 * The pool uses the same discard limits as the underlying data
4106 * device. DM core has already set this up.
4110 * Must explicitly disallow stacking discard limits otherwise the
4111 * block layer will stack them if pool's data device has support.
4113 limits->discard_granularity = 0;
4117 static struct target_type pool_target = {
4118 .name = "thin-pool",
4119 .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
4120 DM_TARGET_IMMUTABLE,
4121 .version = {1, 23, 0},
4122 .module = THIS_MODULE,
4126 .presuspend = pool_presuspend,
4127 .presuspend_undo = pool_presuspend_undo,
4128 .postsuspend = pool_postsuspend,
4129 .preresume = pool_preresume,
4130 .resume = pool_resume,
4131 .message = pool_message,
4132 .status = pool_status,
4133 .iterate_devices = pool_iterate_devices,
4134 .io_hints = pool_io_hints,
4138 *--------------------------------------------------------------
4139 * Thin target methods
4140 *--------------------------------------------------------------
4142 static void thin_get(struct thin_c *tc)
4144 refcount_inc(&tc->refcount);
4147 static void thin_put(struct thin_c *tc)
4149 if (refcount_dec_and_test(&tc->refcount))
4150 complete(&tc->can_destroy);
4153 static void thin_dtr(struct dm_target *ti)
4155 struct thin_c *tc = ti->private;
4157 spin_lock_irq(&tc->pool->lock);
4158 list_del_rcu(&tc->list);
4159 spin_unlock_irq(&tc->pool->lock);
4163 wait_for_completion(&tc->can_destroy);
4165 mutex_lock(&dm_thin_pool_table.mutex);
4167 __pool_dec(tc->pool);
4168 dm_pool_close_thin_device(tc->td);
4169 dm_put_device(ti, tc->pool_dev);
4171 dm_put_device(ti, tc->origin_dev);
4174 mutex_unlock(&dm_thin_pool_table.mutex);
4178 * Thin target parameters:
4180 * <pool_dev> <dev_id> [origin_dev]
4182 * pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
4183 * dev_id: the internal device identifier
4184 * origin_dev: a device external to the pool that should act as the origin
4186 * If the pool device has discards disabled, they get disabled for the thin
4189 static int thin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
4193 struct dm_dev *pool_dev, *origin_dev;
4194 struct mapped_device *pool_md;
4196 mutex_lock(&dm_thin_pool_table.mutex);
4198 if (argc != 2 && argc != 3) {
4199 ti->error = "Invalid argument count";
4204 tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL);
4206 ti->error = "Out of memory";
4210 tc->thin_md = dm_table_get_md(ti->table);
4211 spin_lock_init(&tc->lock);
4212 INIT_LIST_HEAD(&tc->deferred_cells);
4213 bio_list_init(&tc->deferred_bio_list);
4214 bio_list_init(&tc->retry_on_resume_list);
4215 tc->sort_bio_list = RB_ROOT;
4218 if (!strcmp(argv[0], argv[2])) {
4219 ti->error = "Error setting origin device";
4221 goto bad_origin_dev;
4224 r = dm_get_device(ti, argv[2], BLK_OPEN_READ, &origin_dev);
4226 ti->error = "Error opening origin device";
4227 goto bad_origin_dev;
4229 tc->origin_dev = origin_dev;
4232 r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev);
4234 ti->error = "Error opening pool device";
4237 tc->pool_dev = pool_dev;
4239 if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) {
4240 ti->error = "Invalid device id";
4245 pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev);
4247 ti->error = "Couldn't get pool mapped device";
4252 tc->pool = __pool_table_lookup(pool_md);
4254 ti->error = "Couldn't find pool object";
4256 goto bad_pool_lookup;
4258 __pool_inc(tc->pool);
4260 if (get_pool_mode(tc->pool) == PM_FAIL) {
4261 ti->error = "Couldn't open thin device, Pool is in fail mode";
4266 r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td);
4268 ti->error = "Couldn't open thin internal device";
4272 r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
4276 ti->num_flush_bios = 1;
4277 ti->limit_swap_bios = true;
4278 ti->flush_supported = true;
4279 ti->accounts_remapped_io = true;
4280 ti->per_io_data_size = sizeof(struct dm_thin_endio_hook);
4282 /* In case the pool supports discards, pass them on. */
4283 if (tc->pool->pf.discard_enabled) {
4284 ti->discards_supported = true;
4285 ti->num_discard_bios = 1;
4286 ti->max_discard_granularity = true;
4289 mutex_unlock(&dm_thin_pool_table.mutex);
4291 spin_lock_irq(&tc->pool->lock);
4292 if (tc->pool->suspended) {
4293 spin_unlock_irq(&tc->pool->lock);
4294 mutex_lock(&dm_thin_pool_table.mutex); /* reacquire for __pool_dec */
4295 ti->error = "Unable to activate thin device while pool is suspended";
4299 refcount_set(&tc->refcount, 1);
4300 init_completion(&tc->can_destroy);
4301 list_add_tail_rcu(&tc->list, &tc->pool->active_thins);
4302 spin_unlock_irq(&tc->pool->lock);
4304 * This synchronize_rcu() call is needed here otherwise we risk a
4305 * wake_worker() call finding no bios to process (because the newly
4306 * added tc isn't yet visible). So this reduces latency since we
4307 * aren't then dependent on the periodic commit to wake_worker().
4316 dm_pool_close_thin_device(tc->td);
4318 __pool_dec(tc->pool);
4322 dm_put_device(ti, tc->pool_dev);
4325 dm_put_device(ti, tc->origin_dev);
4329 mutex_unlock(&dm_thin_pool_table.mutex);
4334 static int thin_map(struct dm_target *ti, struct bio *bio)
4336 bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector);
4338 return thin_bio_map(ti, bio);
4341 static int thin_endio(struct dm_target *ti, struct bio *bio,
4344 unsigned long flags;
4345 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
4346 struct list_head work;
4347 struct dm_thin_new_mapping *m, *tmp;
4348 struct pool *pool = h->tc->pool;
4350 if (h->shared_read_entry) {
4351 INIT_LIST_HEAD(&work);
4352 dm_deferred_entry_dec(h->shared_read_entry, &work);
4354 spin_lock_irqsave(&pool->lock, flags);
4355 list_for_each_entry_safe(m, tmp, &work, list) {
4357 __complete_mapping_preparation(m);
4359 spin_unlock_irqrestore(&pool->lock, flags);
4362 if (h->all_io_entry) {
4363 INIT_LIST_HEAD(&work);
4364 dm_deferred_entry_dec(h->all_io_entry, &work);
4365 if (!list_empty(&work)) {
4366 spin_lock_irqsave(&pool->lock, flags);
4367 list_for_each_entry_safe(m, tmp, &work, list)
4368 list_add_tail(&m->list, &pool->prepared_discards);
4369 spin_unlock_irqrestore(&pool->lock, flags);
4375 cell_defer_no_holder(h->tc, h->cell);
4377 return DM_ENDIO_DONE;
4380 static void thin_presuspend(struct dm_target *ti)
4382 struct thin_c *tc = ti->private;
4384 if (dm_noflush_suspending(ti))
4385 noflush_work(tc, do_noflush_start);
4388 static void thin_postsuspend(struct dm_target *ti)
4390 struct thin_c *tc = ti->private;
4393 * The dm_noflush_suspending flag has been cleared by now, so
4394 * unfortunately we must always run this.
4396 noflush_work(tc, do_noflush_stop);
4399 static int thin_preresume(struct dm_target *ti)
4401 struct thin_c *tc = ti->private;
4404 tc->origin_size = get_dev_size(tc->origin_dev->bdev);
4410 * <nr mapped sectors> <highest mapped sector>
4412 static void thin_status(struct dm_target *ti, status_type_t type,
4413 unsigned int status_flags, char *result, unsigned int maxlen)
4417 dm_block_t mapped, highest;
4418 char buf[BDEVNAME_SIZE];
4419 struct thin_c *tc = ti->private;
4421 if (get_pool_mode(tc->pool) == PM_FAIL) {
4430 case STATUSTYPE_INFO:
4431 r = dm_thin_get_mapped_count(tc->td, &mapped);
4433 DMERR("dm_thin_get_mapped_count returned %d", r);
4437 r = dm_thin_get_highest_mapped_block(tc->td, &highest);
4439 DMERR("dm_thin_get_highest_mapped_block returned %d", r);
4443 DMEMIT("%llu ", mapped * tc->pool->sectors_per_block);
4445 DMEMIT("%llu", ((highest + 1) *
4446 tc->pool->sectors_per_block) - 1);
4451 case STATUSTYPE_TABLE:
4453 format_dev_t(buf, tc->pool_dev->bdev->bd_dev),
4454 (unsigned long) tc->dev_id);
4456 DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev));
4459 case STATUSTYPE_IMA:
4471 static int thin_iterate_devices(struct dm_target *ti,
4472 iterate_devices_callout_fn fn, void *data)
4475 struct thin_c *tc = ti->private;
4476 struct pool *pool = tc->pool;
4479 * We can't call dm_pool_get_data_dev_size() since that blocks. So
4480 * we follow a more convoluted path through to the pool's target.
4483 return 0; /* nothing is bound */
4485 blocks = pool->ti->len;
4486 (void) sector_div(blocks, pool->sectors_per_block);
4488 return fn(ti, tc->pool_dev, 0, pool->sectors_per_block * blocks, data);
4493 static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
4495 struct thin_c *tc = ti->private;
4496 struct pool *pool = tc->pool;
4498 if (pool->pf.discard_enabled) {
4499 limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
4500 limits->max_discard_sectors = pool->sectors_per_block * BIO_PRISON_MAX_RANGE;
4504 static struct target_type thin_target = {
4506 .version = {1, 23, 0},
4507 .module = THIS_MODULE,
4511 .end_io = thin_endio,
4512 .preresume = thin_preresume,
4513 .presuspend = thin_presuspend,
4514 .postsuspend = thin_postsuspend,
4515 .status = thin_status,
4516 .iterate_devices = thin_iterate_devices,
4517 .io_hints = thin_io_hints,
4520 /*----------------------------------------------------------------*/
4522 static int __init dm_thin_init(void)
4528 _new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
4529 if (!_new_mapping_cache)
4532 r = dm_register_target(&thin_target);
4534 goto bad_new_mapping_cache;
4536 r = dm_register_target(&pool_target);
4538 goto bad_thin_target;
4543 dm_unregister_target(&thin_target);
4544 bad_new_mapping_cache:
4545 kmem_cache_destroy(_new_mapping_cache);
4550 static void dm_thin_exit(void)
4552 dm_unregister_target(&thin_target);
4553 dm_unregister_target(&pool_target);
4555 kmem_cache_destroy(_new_mapping_cache);
4560 module_init(dm_thin_init);
4561 module_exit(dm_thin_exit);
4563 module_param_named(no_space_timeout, no_space_timeout_secs, uint, 0644);
4564 MODULE_PARM_DESC(no_space_timeout, "Out of data space queue IO timeout in seconds");
4566 MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
4567 MODULE_AUTHOR("Joe Thornber <dm-devel@lists.linux.dev>");
4568 MODULE_LICENSE("GPL");