2 * Copyright (C) 2011-2012 Red Hat UK.
4 * This file is released under the GPL.
7 #include "dm-thin-metadata.h"
8 #include "dm-bio-prison.h"
11 #include <linux/device-mapper.h>
12 #include <linux/dm-io.h>
13 #include <linux/dm-kcopyd.h>
14 #include <linux/list.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
19 #define DM_MSG_PREFIX "thin"
24 #define ENDIO_HOOK_POOL_SIZE 1024
25 #define MAPPING_POOL_SIZE 1024
26 #define PRISON_CELLS 1024
27 #define COMMIT_PERIOD HZ
29 DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle,
30 "A percentage of time allocated for copy on write");
33 * The block size of the device holding pool data must be
34 * between 64KB and 1GB.
36 #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
37 #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
40 * Device id is restricted to 24 bits.
42 #define MAX_DEV_ID ((1 << 24) - 1)
45 * How do we handle breaking sharing of data blocks?
46 * =================================================
48 * We use a standard copy-on-write btree to store the mappings for the
49 * devices (note I'm talking about copy-on-write of the metadata here, not
50 * the data). When you take an internal snapshot you clone the root node
51 * of the origin btree. After this there is no concept of an origin or a
52 * snapshot. They are just two device trees that happen to point to the
55 * When we get a write in we decide if it's to a shared data block using
56 * some timestamp magic. If it is, we have to break sharing.
58 * Let's say we write to a shared block in what was the origin. The
61 * i) plug io further to this physical block. (see bio_prison code).
63 * ii) quiesce any read io to that shared data block. Obviously
64 * including all devices that share this block. (see dm_deferred_set code)
66 * iii) copy the data block to a newly allocate block. This step can be
67 * missed out if the io covers the block. (schedule_copy).
69 * iv) insert the new mapping into the origin's btree
70 * (process_prepared_mapping). This act of inserting breaks some
71 * sharing of btree nodes between the two devices. Breaking sharing only
72 * effects the btree of that specific device. Btrees for the other
73 * devices that share the block never change. The btree for the origin
74 * device as it was after the last commit is untouched, ie. we're using
75 * persistent data structures in the functional programming sense.
77 * v) unplug io to this physical block, including the io that triggered
78 * the breaking of sharing.
80 * Steps (ii) and (iii) occur in parallel.
82 * The metadata _doesn't_ need to be committed before the io continues. We
83 * get away with this because the io is always written to a _new_ block.
84 * If there's a crash, then:
86 * - The origin mapping will point to the old origin block (the shared
87 * one). This will contain the data as it was before the io that triggered
88 * the breaking of sharing came in.
90 * - The snap mapping still points to the old block. As it would after
93 * The downside of this scheme is the timestamp magic isn't perfect, and
94 * will continue to think that data block in the snapshot device is shared
95 * even after the write to the origin has broken sharing. I suspect data
96 * blocks will typically be shared by many different devices, so we're
97 * breaking sharing n + 1 times, rather than n, where n is the number of
98 * devices that reference this data block. At the moment I think the
99 * benefits far, far outweigh the disadvantages.
102 /*----------------------------------------------------------------*/
107 static void build_data_key(struct dm_thin_device *td,
108 dm_block_t b, struct dm_cell_key *key)
111 key->dev = dm_thin_dev_id(td);
115 static void build_virtual_key(struct dm_thin_device *td, dm_block_t b,
116 struct dm_cell_key *key)
119 key->dev = dm_thin_dev_id(td);
123 /*----------------------------------------------------------------*/
126 * A pool device ties together a metadata device and a data device. It
127 * also provides the interface for creating and destroying internal
130 struct dm_thin_new_mapping;
133 * The pool runs in 3 modes. Ordered in degraded order for comparisons.
136 PM_WRITE, /* metadata may be changed */
137 PM_READ_ONLY, /* metadata may not be changed */
138 PM_FAIL, /* all I/O fails */
141 struct pool_features {
144 bool zero_new_blocks:1;
145 bool discard_enabled:1;
146 bool discard_passdown:1;
150 typedef void (*process_bio_fn)(struct thin_c *tc, struct bio *bio);
151 typedef void (*process_mapping_fn)(struct dm_thin_new_mapping *m);
154 struct list_head list;
155 struct dm_target *ti; /* Only set if a pool target is bound */
157 struct mapped_device *pool_md;
158 struct block_device *md_dev;
159 struct dm_pool_metadata *pmd;
161 dm_block_t low_water_blocks;
162 uint32_t sectors_per_block;
163 int sectors_per_block_shift;
165 struct pool_features pf;
166 unsigned low_water_triggered:1; /* A dm event has been sent */
167 unsigned no_free_space:1; /* A -ENOSPC warning has been issued */
169 struct dm_bio_prison *prison;
170 struct dm_kcopyd_client *copier;
172 struct workqueue_struct *wq;
173 struct work_struct worker;
174 struct delayed_work waker;
176 unsigned long last_commit_jiffies;
180 struct bio_list deferred_bios;
181 struct bio_list deferred_flush_bios;
182 struct list_head prepared_mappings;
183 struct list_head prepared_discards;
185 struct bio_list retry_on_resume_list;
187 struct dm_deferred_set *shared_read_ds;
188 struct dm_deferred_set *all_io_ds;
190 struct dm_thin_new_mapping *next_mapping;
191 mempool_t *mapping_pool;
193 process_bio_fn process_bio;
194 process_bio_fn process_discard;
196 process_mapping_fn process_prepared_mapping;
197 process_mapping_fn process_prepared_discard;
200 static enum pool_mode get_pool_mode(struct pool *pool);
201 static void set_pool_mode(struct pool *pool, enum pool_mode mode);
204 * Target context for a pool.
207 struct dm_target *ti;
209 struct dm_dev *data_dev;
210 struct dm_dev *metadata_dev;
211 struct dm_target_callbacks callbacks;
213 dm_block_t low_water_blocks;
214 struct pool_features requested_pf; /* Features requested during table load */
215 struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */
219 * Target context for a thin.
222 struct dm_dev *pool_dev;
223 struct dm_dev *origin_dev;
227 struct dm_thin_device *td;
230 /*----------------------------------------------------------------*/
233 * wake_worker() is used when new work is queued and when pool_resume is
234 * ready to continue deferred IO processing.
236 static void wake_worker(struct pool *pool)
238 queue_work(pool->wq, &pool->worker);
241 /*----------------------------------------------------------------*/
243 static int bio_detain(struct pool *pool, struct dm_cell_key *key, struct bio *bio,
244 struct dm_bio_prison_cell **cell_result)
247 struct dm_bio_prison_cell *cell_prealloc;
250 * Allocate a cell from the prison's mempool.
251 * This might block but it can't fail.
253 cell_prealloc = dm_bio_prison_alloc_cell(pool->prison, GFP_NOIO);
255 r = dm_bio_detain(pool->prison, key, bio, cell_prealloc, cell_result);
258 * We reused an old cell; we can get rid of
261 dm_bio_prison_free_cell(pool->prison, cell_prealloc);
266 static void cell_release(struct pool *pool,
267 struct dm_bio_prison_cell *cell,
268 struct bio_list *bios)
270 dm_cell_release(pool->prison, cell, bios);
271 dm_bio_prison_free_cell(pool->prison, cell);
274 static void cell_release_no_holder(struct pool *pool,
275 struct dm_bio_prison_cell *cell,
276 struct bio_list *bios)
278 dm_cell_release_no_holder(pool->prison, cell, bios);
279 dm_bio_prison_free_cell(pool->prison, cell);
282 static void cell_defer_no_holder_no_free(struct thin_c *tc,
283 struct dm_bio_prison_cell *cell)
285 struct pool *pool = tc->pool;
288 spin_lock_irqsave(&pool->lock, flags);
289 dm_cell_release_no_holder(pool->prison, cell, &pool->deferred_bios);
290 spin_unlock_irqrestore(&pool->lock, flags);
295 static void cell_error(struct pool *pool,
296 struct dm_bio_prison_cell *cell)
298 dm_cell_error(pool->prison, cell);
299 dm_bio_prison_free_cell(pool->prison, cell);
302 /*----------------------------------------------------------------*/
305 * A global list of pools that uses a struct mapped_device as a key.
307 static struct dm_thin_pool_table {
309 struct list_head pools;
310 } dm_thin_pool_table;
312 static void pool_table_init(void)
314 mutex_init(&dm_thin_pool_table.mutex);
315 INIT_LIST_HEAD(&dm_thin_pool_table.pools);
318 static void __pool_table_insert(struct pool *pool)
320 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
321 list_add(&pool->list, &dm_thin_pool_table.pools);
324 static void __pool_table_remove(struct pool *pool)
326 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
327 list_del(&pool->list);
330 static struct pool *__pool_table_lookup(struct mapped_device *md)
332 struct pool *pool = NULL, *tmp;
334 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
336 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
337 if (tmp->pool_md == md) {
346 static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev)
348 struct pool *pool = NULL, *tmp;
350 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
352 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
353 if (tmp->md_dev == md_dev) {
362 /*----------------------------------------------------------------*/
364 struct dm_thin_endio_hook {
366 struct dm_deferred_entry *shared_read_entry;
367 struct dm_deferred_entry *all_io_entry;
368 struct dm_thin_new_mapping *overwrite_mapping;
371 static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master)
374 struct bio_list bios;
376 bio_list_init(&bios);
377 bio_list_merge(&bios, master);
378 bio_list_init(master);
380 while ((bio = bio_list_pop(&bios))) {
381 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
384 bio_endio(bio, DM_ENDIO_REQUEUE);
386 bio_list_add(master, bio);
390 static void requeue_io(struct thin_c *tc)
392 struct pool *pool = tc->pool;
395 spin_lock_irqsave(&pool->lock, flags);
396 __requeue_bio_list(tc, &pool->deferred_bios);
397 __requeue_bio_list(tc, &pool->retry_on_resume_list);
398 spin_unlock_irqrestore(&pool->lock, flags);
402 * This section of code contains the logic for processing a thin device's IO.
403 * Much of the code depends on pool object resources (lists, workqueues, etc)
404 * but most is exclusively called from the thin target rather than the thin-pool
408 static bool block_size_is_power_of_two(struct pool *pool)
410 return pool->sectors_per_block_shift >= 0;
413 static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
415 struct pool *pool = tc->pool;
416 sector_t block_nr = bio->bi_sector;
418 if (block_size_is_power_of_two(pool))
419 block_nr >>= pool->sectors_per_block_shift;
421 (void) sector_div(block_nr, pool->sectors_per_block);
426 static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
428 struct pool *pool = tc->pool;
429 sector_t bi_sector = bio->bi_sector;
431 bio->bi_bdev = tc->pool_dev->bdev;
432 if (block_size_is_power_of_two(pool))
433 bio->bi_sector = (block << pool->sectors_per_block_shift) |
434 (bi_sector & (pool->sectors_per_block - 1));
436 bio->bi_sector = (block * pool->sectors_per_block) +
437 sector_div(bi_sector, pool->sectors_per_block);
440 static void remap_to_origin(struct thin_c *tc, struct bio *bio)
442 bio->bi_bdev = tc->origin_dev->bdev;
445 static int bio_triggers_commit(struct thin_c *tc, struct bio *bio)
447 return (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) &&
448 dm_thin_changed_this_transaction(tc->td);
451 static void inc_all_io_entry(struct pool *pool, struct bio *bio)
453 struct dm_thin_endio_hook *h;
455 if (bio->bi_rw & REQ_DISCARD)
458 h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
459 h->all_io_entry = dm_deferred_entry_inc(pool->all_io_ds);
462 static void issue(struct thin_c *tc, struct bio *bio)
464 struct pool *pool = tc->pool;
467 if (!bio_triggers_commit(tc, bio)) {
468 generic_make_request(bio);
473 * Complete bio with an error if earlier I/O caused changes to
474 * the metadata that can't be committed e.g, due to I/O errors
475 * on the metadata device.
477 if (dm_thin_aborted_changes(tc->td)) {
483 * Batch together any bios that trigger commits and then issue a
484 * single commit for them in process_deferred_bios().
486 spin_lock_irqsave(&pool->lock, flags);
487 bio_list_add(&pool->deferred_flush_bios, bio);
488 spin_unlock_irqrestore(&pool->lock, flags);
491 static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio)
493 remap_to_origin(tc, bio);
497 static void remap_and_issue(struct thin_c *tc, struct bio *bio,
500 remap(tc, bio, block);
504 /*----------------------------------------------------------------*/
507 * Bio endio functions.
509 struct dm_thin_new_mapping {
510 struct list_head list;
514 unsigned pass_discard:1;
517 dm_block_t virt_block;
518 dm_block_t data_block;
519 struct dm_bio_prison_cell *cell, *cell2;
523 * If the bio covers the whole area of a block then we can avoid
524 * zeroing or copying. Instead this bio is hooked. The bio will
525 * still be in the cell, so care has to be taken to avoid issuing
529 bio_end_io_t *saved_bi_end_io;
532 static void __maybe_add_mapping(struct dm_thin_new_mapping *m)
534 struct pool *pool = m->tc->pool;
536 if (m->quiesced && m->prepared) {
537 list_add(&m->list, &pool->prepared_mappings);
542 static void copy_complete(int read_err, unsigned long write_err, void *context)
545 struct dm_thin_new_mapping *m = context;
546 struct pool *pool = m->tc->pool;
548 m->err = read_err || write_err ? -EIO : 0;
550 spin_lock_irqsave(&pool->lock, flags);
552 __maybe_add_mapping(m);
553 spin_unlock_irqrestore(&pool->lock, flags);
556 static void overwrite_endio(struct bio *bio, int err)
559 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
560 struct dm_thin_new_mapping *m = h->overwrite_mapping;
561 struct pool *pool = m->tc->pool;
565 spin_lock_irqsave(&pool->lock, flags);
567 __maybe_add_mapping(m);
568 spin_unlock_irqrestore(&pool->lock, flags);
571 /*----------------------------------------------------------------*/
578 * Prepared mapping jobs.
582 * This sends the bios in the cell back to the deferred_bios list.
584 static void cell_defer(struct thin_c *tc, struct dm_bio_prison_cell *cell)
586 struct pool *pool = tc->pool;
589 spin_lock_irqsave(&pool->lock, flags);
590 cell_release(pool, cell, &pool->deferred_bios);
591 spin_unlock_irqrestore(&tc->pool->lock, flags);
597 * Same as cell_defer above, except it omits the original holder of the cell.
599 static void cell_defer_no_holder(struct thin_c *tc, struct dm_bio_prison_cell *cell)
601 struct pool *pool = tc->pool;
604 spin_lock_irqsave(&pool->lock, flags);
605 cell_release_no_holder(pool, cell, &pool->deferred_bios);
606 spin_unlock_irqrestore(&pool->lock, flags);
611 static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
614 m->bio->bi_end_io = m->saved_bi_end_io;
615 cell_error(m->tc->pool, m->cell);
617 mempool_free(m, m->tc->pool->mapping_pool);
620 static void process_prepared_mapping(struct dm_thin_new_mapping *m)
622 struct thin_c *tc = m->tc;
623 struct pool *pool = tc->pool;
629 bio->bi_end_io = m->saved_bi_end_io;
632 cell_error(pool, m->cell);
637 * Commit the prepared block into the mapping btree.
638 * Any I/O for this block arriving after this point will get
639 * remapped to it directly.
641 r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);
643 DMERR_LIMIT("dm_thin_insert_block() failed");
644 cell_error(pool, m->cell);
649 * Release any bios held while the block was being provisioned.
650 * If we are processing a write bio that completely covers the block,
651 * we already processed it so can ignore it now when processing
652 * the bios in the cell.
655 cell_defer_no_holder(tc, m->cell);
658 cell_defer(tc, m->cell);
662 mempool_free(m, pool->mapping_pool);
665 static void process_prepared_discard_fail(struct dm_thin_new_mapping *m)
667 struct thin_c *tc = m->tc;
669 bio_io_error(m->bio);
670 cell_defer_no_holder(tc, m->cell);
671 cell_defer_no_holder(tc, m->cell2);
672 mempool_free(m, tc->pool->mapping_pool);
675 static void process_prepared_discard_passdown(struct dm_thin_new_mapping *m)
677 struct thin_c *tc = m->tc;
679 inc_all_io_entry(tc->pool, m->bio);
680 cell_defer_no_holder(tc, m->cell);
681 cell_defer_no_holder(tc, m->cell2);
684 remap_and_issue(tc, m->bio, m->data_block);
686 bio_endio(m->bio, 0);
688 mempool_free(m, tc->pool->mapping_pool);
691 static void process_prepared_discard(struct dm_thin_new_mapping *m)
694 struct thin_c *tc = m->tc;
696 r = dm_thin_remove_block(tc->td, m->virt_block);
698 DMERR_LIMIT("dm_thin_remove_block() failed");
700 process_prepared_discard_passdown(m);
703 static void process_prepared(struct pool *pool, struct list_head *head,
704 process_mapping_fn *fn)
707 struct list_head maps;
708 struct dm_thin_new_mapping *m, *tmp;
710 INIT_LIST_HEAD(&maps);
711 spin_lock_irqsave(&pool->lock, flags);
712 list_splice_init(head, &maps);
713 spin_unlock_irqrestore(&pool->lock, flags);
715 list_for_each_entry_safe(m, tmp, &maps, list)
722 static int io_overlaps_block(struct pool *pool, struct bio *bio)
724 return bio->bi_size == (pool->sectors_per_block << SECTOR_SHIFT);
727 static int io_overwrites_block(struct pool *pool, struct bio *bio)
729 return (bio_data_dir(bio) == WRITE) &&
730 io_overlaps_block(pool, bio);
733 static void save_and_set_endio(struct bio *bio, bio_end_io_t **save,
736 *save = bio->bi_end_io;
740 static int ensure_next_mapping(struct pool *pool)
742 if (pool->next_mapping)
745 pool->next_mapping = mempool_alloc(pool->mapping_pool, GFP_ATOMIC);
747 return pool->next_mapping ? 0 : -ENOMEM;
750 static struct dm_thin_new_mapping *get_next_mapping(struct pool *pool)
752 struct dm_thin_new_mapping *r = pool->next_mapping;
754 BUG_ON(!pool->next_mapping);
756 pool->next_mapping = NULL;
761 static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
762 struct dm_dev *origin, dm_block_t data_origin,
763 dm_block_t data_dest,
764 struct dm_bio_prison_cell *cell, struct bio *bio)
767 struct pool *pool = tc->pool;
768 struct dm_thin_new_mapping *m = get_next_mapping(pool);
770 INIT_LIST_HEAD(&m->list);
774 m->virt_block = virt_block;
775 m->data_block = data_dest;
780 if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list))
784 * IO to pool_dev remaps to the pool target's data_dev.
786 * If the whole block of data is being overwritten, we can issue the
787 * bio immediately. Otherwise we use kcopyd to clone the data first.
789 if (io_overwrites_block(pool, bio)) {
790 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
792 h->overwrite_mapping = m;
794 save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
795 inc_all_io_entry(pool, bio);
796 remap_and_issue(tc, bio, data_dest);
798 struct dm_io_region from, to;
800 from.bdev = origin->bdev;
801 from.sector = data_origin * pool->sectors_per_block;
802 from.count = pool->sectors_per_block;
804 to.bdev = tc->pool_dev->bdev;
805 to.sector = data_dest * pool->sectors_per_block;
806 to.count = pool->sectors_per_block;
808 r = dm_kcopyd_copy(pool->copier, &from, 1, &to,
809 0, copy_complete, m);
811 mempool_free(m, pool->mapping_pool);
812 DMERR_LIMIT("dm_kcopyd_copy() failed");
813 cell_error(pool, cell);
818 static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block,
819 dm_block_t data_origin, dm_block_t data_dest,
820 struct dm_bio_prison_cell *cell, struct bio *bio)
822 schedule_copy(tc, virt_block, tc->pool_dev,
823 data_origin, data_dest, cell, bio);
826 static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block,
827 dm_block_t data_dest,
828 struct dm_bio_prison_cell *cell, struct bio *bio)
830 schedule_copy(tc, virt_block, tc->origin_dev,
831 virt_block, data_dest, cell, bio);
834 static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
835 dm_block_t data_block, struct dm_bio_prison_cell *cell,
838 struct pool *pool = tc->pool;
839 struct dm_thin_new_mapping *m = get_next_mapping(pool);
841 INIT_LIST_HEAD(&m->list);
845 m->virt_block = virt_block;
846 m->data_block = data_block;
852 * If the whole block of data is being overwritten or we are not
853 * zeroing pre-existing data, we can issue the bio immediately.
854 * Otherwise we use kcopyd to zero the data first.
856 if (!pool->pf.zero_new_blocks)
857 process_prepared_mapping(m);
859 else if (io_overwrites_block(pool, bio)) {
860 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
862 h->overwrite_mapping = m;
864 save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
865 inc_all_io_entry(pool, bio);
866 remap_and_issue(tc, bio, data_block);
869 struct dm_io_region to;
871 to.bdev = tc->pool_dev->bdev;
872 to.sector = data_block * pool->sectors_per_block;
873 to.count = pool->sectors_per_block;
875 r = dm_kcopyd_zero(pool->copier, 1, &to, 0, copy_complete, m);
877 mempool_free(m, pool->mapping_pool);
878 DMERR_LIMIT("dm_kcopyd_zero() failed");
879 cell_error(pool, cell);
884 static int commit(struct pool *pool)
888 r = dm_pool_commit_metadata(pool->pmd);
890 DMERR_LIMIT("commit failed: error = %d", r);
896 * A non-zero return indicates read_only or fail_io mode.
897 * Many callers don't care about the return value.
899 static int commit_or_fallback(struct pool *pool)
903 if (get_pool_mode(pool) != PM_WRITE)
908 set_pool_mode(pool, PM_READ_ONLY);
913 static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
916 dm_block_t free_blocks;
918 struct pool *pool = tc->pool;
920 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
924 if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) {
925 DMWARN("%s: reached low water mark, sending event.",
926 dm_device_name(pool->pool_md));
927 spin_lock_irqsave(&pool->lock, flags);
928 pool->low_water_triggered = 1;
929 spin_unlock_irqrestore(&pool->lock, flags);
930 dm_table_event(pool->ti->table);
934 if (pool->no_free_space)
938 * Try to commit to see if that will free up some
941 (void) commit_or_fallback(pool);
943 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
948 * If we still have no space we set a flag to avoid
949 * doing all this checking and return -ENOSPC.
952 DMWARN("%s: no free space available.",
953 dm_device_name(pool->pool_md));
954 spin_lock_irqsave(&pool->lock, flags);
955 pool->no_free_space = 1;
956 spin_unlock_irqrestore(&pool->lock, flags);
962 r = dm_pool_alloc_data_block(pool->pmd, result);
970 * If we have run out of space, queue bios until the device is
971 * resumed, presumably after having been reloaded with more space.
973 static void retry_on_resume(struct bio *bio)
975 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
976 struct thin_c *tc = h->tc;
977 struct pool *pool = tc->pool;
980 spin_lock_irqsave(&pool->lock, flags);
981 bio_list_add(&pool->retry_on_resume_list, bio);
982 spin_unlock_irqrestore(&pool->lock, flags);
985 static void no_space(struct pool *pool, struct dm_bio_prison_cell *cell)
988 struct bio_list bios;
990 bio_list_init(&bios);
991 cell_release(pool, cell, &bios);
993 while ((bio = bio_list_pop(&bios)))
994 retry_on_resume(bio);
997 static void process_discard(struct thin_c *tc, struct bio *bio)
1000 unsigned long flags;
1001 struct pool *pool = tc->pool;
1002 struct dm_bio_prison_cell *cell, *cell2;
1003 struct dm_cell_key key, key2;
1004 dm_block_t block = get_bio_block(tc, bio);
1005 struct dm_thin_lookup_result lookup_result;
1006 struct dm_thin_new_mapping *m;
1008 build_virtual_key(tc->td, block, &key);
1009 if (bio_detain(tc->pool, &key, bio, &cell))
1012 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1016 * Check nobody is fiddling with this pool block. This can
1017 * happen if someone's in the process of breaking sharing
1020 build_data_key(tc->td, lookup_result.block, &key2);
1021 if (bio_detain(tc->pool, &key2, bio, &cell2)) {
1022 cell_defer_no_holder(tc, cell);
1026 if (io_overlaps_block(pool, bio)) {
1028 * IO may still be going to the destination block. We must
1029 * quiesce before we can do the removal.
1031 m = get_next_mapping(pool);
1033 m->pass_discard = (!lookup_result.shared) && pool->pf.discard_passdown;
1034 m->virt_block = block;
1035 m->data_block = lookup_result.block;
1041 if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) {
1042 spin_lock_irqsave(&pool->lock, flags);
1043 list_add(&m->list, &pool->prepared_discards);
1044 spin_unlock_irqrestore(&pool->lock, flags);
1048 inc_all_io_entry(pool, bio);
1049 cell_defer_no_holder(tc, cell);
1050 cell_defer_no_holder(tc, cell2);
1053 * The DM core makes sure that the discard doesn't span
1054 * a block boundary. So we submit the discard of a
1055 * partial block appropriately.
1057 if ((!lookup_result.shared) && pool->pf.discard_passdown)
1058 remap_and_issue(tc, bio, lookup_result.block);
1066 * It isn't provisioned, just forget it.
1068 cell_defer_no_holder(tc, cell);
1073 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1075 cell_defer_no_holder(tc, cell);
1081 static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
1082 struct dm_cell_key *key,
1083 struct dm_thin_lookup_result *lookup_result,
1084 struct dm_bio_prison_cell *cell)
1087 dm_block_t data_block;
1089 r = alloc_data_block(tc, &data_block);
1092 schedule_internal_copy(tc, block, lookup_result->block,
1093 data_block, cell, bio);
1097 no_space(tc->pool, cell);
1101 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1103 cell_error(tc->pool, cell);
1108 static void process_shared_bio(struct thin_c *tc, struct bio *bio,
1110 struct dm_thin_lookup_result *lookup_result)
1112 struct dm_bio_prison_cell *cell;
1113 struct pool *pool = tc->pool;
1114 struct dm_cell_key key;
1117 * If cell is already occupied, then sharing is already in the process
1118 * of being broken so we have nothing further to do here.
1120 build_data_key(tc->td, lookup_result->block, &key);
1121 if (bio_detain(pool, &key, bio, &cell))
1124 if (bio_data_dir(bio) == WRITE && bio->bi_size)
1125 break_sharing(tc, bio, block, &key, lookup_result, cell);
1127 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
1129 h->shared_read_entry = dm_deferred_entry_inc(pool->shared_read_ds);
1130 inc_all_io_entry(pool, bio);
1131 cell_defer_no_holder(tc, cell);
1133 remap_and_issue(tc, bio, lookup_result->block);
1137 static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block,
1138 struct dm_bio_prison_cell *cell)
1141 dm_block_t data_block;
1142 struct pool *pool = tc->pool;
1145 * Remap empty bios (flushes) immediately, without provisioning.
1147 if (!bio->bi_size) {
1148 inc_all_io_entry(pool, bio);
1149 cell_defer_no_holder(tc, cell);
1151 remap_and_issue(tc, bio, 0);
1156 * Fill read bios with zeroes and complete them immediately.
1158 if (bio_data_dir(bio) == READ) {
1160 cell_defer_no_holder(tc, cell);
1165 r = alloc_data_block(tc, &data_block);
1169 schedule_external_copy(tc, block, data_block, cell, bio);
1171 schedule_zero(tc, block, data_block, cell, bio);
1175 no_space(pool, cell);
1179 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1181 set_pool_mode(pool, PM_READ_ONLY);
1182 cell_error(pool, cell);
1187 static void process_bio(struct thin_c *tc, struct bio *bio)
1190 struct pool *pool = tc->pool;
1191 dm_block_t block = get_bio_block(tc, bio);
1192 struct dm_bio_prison_cell *cell;
1193 struct dm_cell_key key;
1194 struct dm_thin_lookup_result lookup_result;
1197 * If cell is already occupied, then the block is already
1198 * being provisioned so we have nothing further to do here.
1200 build_virtual_key(tc->td, block, &key);
1201 if (bio_detain(pool, &key, bio, &cell))
1204 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1207 if (lookup_result.shared) {
1208 process_shared_bio(tc, bio, block, &lookup_result);
1209 cell_defer_no_holder(tc, cell); /* FIXME: pass this cell into process_shared? */
1211 inc_all_io_entry(pool, bio);
1212 cell_defer_no_holder(tc, cell);
1214 remap_and_issue(tc, bio, lookup_result.block);
1219 if (bio_data_dir(bio) == READ && tc->origin_dev) {
1220 inc_all_io_entry(pool, bio);
1221 cell_defer_no_holder(tc, cell);
1223 remap_to_origin_and_issue(tc, bio);
1225 provision_block(tc, bio, block, cell);
1229 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1231 cell_defer_no_holder(tc, cell);
1237 static void process_bio_read_only(struct thin_c *tc, struct bio *bio)
1240 int rw = bio_data_dir(bio);
1241 dm_block_t block = get_bio_block(tc, bio);
1242 struct dm_thin_lookup_result lookup_result;
1244 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1247 if (lookup_result.shared && (rw == WRITE) && bio->bi_size)
1250 inc_all_io_entry(tc->pool, bio);
1251 remap_and_issue(tc, bio, lookup_result.block);
1261 if (tc->origin_dev) {
1262 inc_all_io_entry(tc->pool, bio);
1263 remap_to_origin_and_issue(tc, bio);
1272 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1279 static void process_bio_fail(struct thin_c *tc, struct bio *bio)
1284 static int need_commit_due_to_time(struct pool *pool)
1286 return jiffies < pool->last_commit_jiffies ||
1287 jiffies > pool->last_commit_jiffies + COMMIT_PERIOD;
1290 static void process_deferred_bios(struct pool *pool)
1292 unsigned long flags;
1294 struct bio_list bios;
1296 bio_list_init(&bios);
1298 spin_lock_irqsave(&pool->lock, flags);
1299 bio_list_merge(&bios, &pool->deferred_bios);
1300 bio_list_init(&pool->deferred_bios);
1301 spin_unlock_irqrestore(&pool->lock, flags);
1303 while ((bio = bio_list_pop(&bios))) {
1304 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
1305 struct thin_c *tc = h->tc;
1308 * If we've got no free new_mapping structs, and processing
1309 * this bio might require one, we pause until there are some
1310 * prepared mappings to process.
1312 if (ensure_next_mapping(pool)) {
1313 spin_lock_irqsave(&pool->lock, flags);
1314 bio_list_merge(&pool->deferred_bios, &bios);
1315 spin_unlock_irqrestore(&pool->lock, flags);
1320 if (bio->bi_rw & REQ_DISCARD)
1321 pool->process_discard(tc, bio);
1323 pool->process_bio(tc, bio);
1327 * If there are any deferred flush bios, we must commit
1328 * the metadata before issuing them.
1330 bio_list_init(&bios);
1331 spin_lock_irqsave(&pool->lock, flags);
1332 bio_list_merge(&bios, &pool->deferred_flush_bios);
1333 bio_list_init(&pool->deferred_flush_bios);
1334 spin_unlock_irqrestore(&pool->lock, flags);
1336 if (bio_list_empty(&bios) && !need_commit_due_to_time(pool))
1339 if (commit_or_fallback(pool)) {
1340 while ((bio = bio_list_pop(&bios)))
1344 pool->last_commit_jiffies = jiffies;
1346 while ((bio = bio_list_pop(&bios)))
1347 generic_make_request(bio);
1350 static void do_worker(struct work_struct *ws)
1352 struct pool *pool = container_of(ws, struct pool, worker);
1354 process_prepared(pool, &pool->prepared_mappings, &pool->process_prepared_mapping);
1355 process_prepared(pool, &pool->prepared_discards, &pool->process_prepared_discard);
1356 process_deferred_bios(pool);
1360 * We want to commit periodically so that not too much
1361 * unwritten data builds up.
1363 static void do_waker(struct work_struct *ws)
1365 struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker);
1367 queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD);
1370 /*----------------------------------------------------------------*/
1372 static enum pool_mode get_pool_mode(struct pool *pool)
1374 return pool->pf.mode;
1377 static void set_pool_mode(struct pool *pool, enum pool_mode mode)
1381 pool->pf.mode = mode;
1385 DMERR("switching pool to failure mode");
1386 pool->process_bio = process_bio_fail;
1387 pool->process_discard = process_bio_fail;
1388 pool->process_prepared_mapping = process_prepared_mapping_fail;
1389 pool->process_prepared_discard = process_prepared_discard_fail;
1393 DMERR("switching pool to read-only mode");
1394 r = dm_pool_abort_metadata(pool->pmd);
1396 DMERR("aborting transaction failed");
1397 set_pool_mode(pool, PM_FAIL);
1399 dm_pool_metadata_read_only(pool->pmd);
1400 pool->process_bio = process_bio_read_only;
1401 pool->process_discard = process_discard;
1402 pool->process_prepared_mapping = process_prepared_mapping_fail;
1403 pool->process_prepared_discard = process_prepared_discard_passdown;
1408 pool->process_bio = process_bio;
1409 pool->process_discard = process_discard;
1410 pool->process_prepared_mapping = process_prepared_mapping;
1411 pool->process_prepared_discard = process_prepared_discard;
1416 /*----------------------------------------------------------------*/
1419 * Mapping functions.
1423 * Called only while mapping a thin bio to hand it over to the workqueue.
1425 static void thin_defer_bio(struct thin_c *tc, struct bio *bio)
1427 unsigned long flags;
1428 struct pool *pool = tc->pool;
1430 spin_lock_irqsave(&pool->lock, flags);
1431 bio_list_add(&pool->deferred_bios, bio);
1432 spin_unlock_irqrestore(&pool->lock, flags);
1437 static void thin_hook_bio(struct thin_c *tc, struct bio *bio)
1439 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
1442 h->shared_read_entry = NULL;
1443 h->all_io_entry = NULL;
1444 h->overwrite_mapping = NULL;
1448 * Non-blocking function called from the thin target's map function.
1450 static int thin_bio_map(struct dm_target *ti, struct bio *bio)
1453 struct thin_c *tc = ti->private;
1454 dm_block_t block = get_bio_block(tc, bio);
1455 struct dm_thin_device *td = tc->td;
1456 struct dm_thin_lookup_result result;
1457 struct dm_bio_prison_cell cell1, cell2;
1458 struct dm_bio_prison_cell *cell_result;
1459 struct dm_cell_key key;
1461 thin_hook_bio(tc, bio);
1463 if (get_pool_mode(tc->pool) == PM_FAIL) {
1465 return DM_MAPIO_SUBMITTED;
1468 if (bio->bi_rw & (REQ_DISCARD | REQ_FLUSH | REQ_FUA)) {
1469 thin_defer_bio(tc, bio);
1470 return DM_MAPIO_SUBMITTED;
1473 r = dm_thin_find_block(td, block, 0, &result);
1476 * Note that we defer readahead too.
1480 if (unlikely(result.shared)) {
1482 * We have a race condition here between the
1483 * result.shared value returned by the lookup and
1484 * snapshot creation, which may cause new
1487 * To avoid this always quiesce the origin before
1488 * taking the snap. You want to do this anyway to
1489 * ensure a consistent application view
1492 * More distant ancestors are irrelevant. The
1493 * shared flag will be set in their case.
1495 thin_defer_bio(tc, bio);
1496 return DM_MAPIO_SUBMITTED;
1499 build_virtual_key(tc->td, block, &key);
1500 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell1, &cell_result))
1501 return DM_MAPIO_SUBMITTED;
1503 build_data_key(tc->td, result.block, &key);
1504 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell2, &cell_result)) {
1505 cell_defer_no_holder_no_free(tc, &cell1);
1506 return DM_MAPIO_SUBMITTED;
1509 inc_all_io_entry(tc->pool, bio);
1510 cell_defer_no_holder_no_free(tc, &cell2);
1511 cell_defer_no_holder_no_free(tc, &cell1);
1513 remap(tc, bio, result.block);
1514 return DM_MAPIO_REMAPPED;
1517 if (get_pool_mode(tc->pool) == PM_READ_ONLY) {
1519 * This block isn't provisioned, and we have no way
1520 * of doing so. Just error it.
1523 return DM_MAPIO_SUBMITTED;
1529 * In future, the failed dm_thin_find_block above could
1530 * provide the hint to load the metadata into cache.
1532 thin_defer_bio(tc, bio);
1533 return DM_MAPIO_SUBMITTED;
1537 * Must always call bio_io_error on failure.
1538 * dm_thin_find_block can fail with -EINVAL if the
1539 * pool is switched to fail-io mode.
1542 return DM_MAPIO_SUBMITTED;
1546 static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
1549 unsigned long flags;
1550 struct pool_c *pt = container_of(cb, struct pool_c, callbacks);
1552 spin_lock_irqsave(&pt->pool->lock, flags);
1553 r = !bio_list_empty(&pt->pool->retry_on_resume_list);
1554 spin_unlock_irqrestore(&pt->pool->lock, flags);
1557 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
1558 r = bdi_congested(&q->backing_dev_info, bdi_bits);
1564 static void __requeue_bios(struct pool *pool)
1566 bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list);
1567 bio_list_init(&pool->retry_on_resume_list);
1570 /*----------------------------------------------------------------
1571 * Binding of control targets to a pool object
1572 *--------------------------------------------------------------*/
1573 static bool data_dev_supports_discard(struct pool_c *pt)
1575 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
1577 return q && blk_queue_discard(q);
1581 * If discard_passdown was enabled verify that the data device
1582 * supports discards. Disable discard_passdown if not.
1584 static void disable_passdown_if_not_supported(struct pool_c *pt)
1586 struct pool *pool = pt->pool;
1587 struct block_device *data_bdev = pt->data_dev->bdev;
1588 struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits;
1589 sector_t block_size = pool->sectors_per_block << SECTOR_SHIFT;
1590 const char *reason = NULL;
1591 char buf[BDEVNAME_SIZE];
1593 if (!pt->adjusted_pf.discard_passdown)
1596 if (!data_dev_supports_discard(pt))
1597 reason = "discard unsupported";
1599 else if (data_limits->max_discard_sectors < pool->sectors_per_block)
1600 reason = "max discard sectors smaller than a block";
1602 else if (data_limits->discard_granularity > block_size)
1603 reason = "discard granularity larger than a block";
1605 else if (block_size & (data_limits->discard_granularity - 1))
1606 reason = "discard granularity not a factor of block size";
1609 DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev, buf), reason);
1610 pt->adjusted_pf.discard_passdown = false;
1614 static int bind_control_target(struct pool *pool, struct dm_target *ti)
1616 struct pool_c *pt = ti->private;
1619 * We want to make sure that degraded pools are never upgraded.
1621 enum pool_mode old_mode = pool->pf.mode;
1622 enum pool_mode new_mode = pt->adjusted_pf.mode;
1624 if (old_mode > new_mode)
1625 new_mode = old_mode;
1628 pool->low_water_blocks = pt->low_water_blocks;
1629 pool->pf = pt->adjusted_pf;
1631 set_pool_mode(pool, new_mode);
1636 static void unbind_control_target(struct pool *pool, struct dm_target *ti)
1642 /*----------------------------------------------------------------
1644 *--------------------------------------------------------------*/
1645 /* Initialize pool features. */
1646 static void pool_features_init(struct pool_features *pf)
1648 pf->mode = PM_WRITE;
1649 pf->zero_new_blocks = true;
1650 pf->discard_enabled = true;
1651 pf->discard_passdown = true;
1654 static void __pool_destroy(struct pool *pool)
1656 __pool_table_remove(pool);
1658 if (dm_pool_metadata_close(pool->pmd) < 0)
1659 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
1661 dm_bio_prison_destroy(pool->prison);
1662 dm_kcopyd_client_destroy(pool->copier);
1665 destroy_workqueue(pool->wq);
1667 if (pool->next_mapping)
1668 mempool_free(pool->next_mapping, pool->mapping_pool);
1669 mempool_destroy(pool->mapping_pool);
1670 dm_deferred_set_destroy(pool->shared_read_ds);
1671 dm_deferred_set_destroy(pool->all_io_ds);
1675 static struct kmem_cache *_new_mapping_cache;
1677 static struct pool *pool_create(struct mapped_device *pool_md,
1678 struct block_device *metadata_dev,
1679 unsigned long block_size,
1680 int read_only, char **error)
1685 struct dm_pool_metadata *pmd;
1686 bool format_device = read_only ? false : true;
1688 pmd = dm_pool_metadata_open(metadata_dev, block_size, format_device);
1690 *error = "Error creating metadata object";
1691 return (struct pool *)pmd;
1694 pool = kmalloc(sizeof(*pool), GFP_KERNEL);
1696 *error = "Error allocating memory for pool";
1697 err_p = ERR_PTR(-ENOMEM);
1702 pool->sectors_per_block = block_size;
1703 if (block_size & (block_size - 1))
1704 pool->sectors_per_block_shift = -1;
1706 pool->sectors_per_block_shift = __ffs(block_size);
1707 pool->low_water_blocks = 0;
1708 pool_features_init(&pool->pf);
1709 pool->prison = dm_bio_prison_create(PRISON_CELLS);
1710 if (!pool->prison) {
1711 *error = "Error creating pool's bio prison";
1712 err_p = ERR_PTR(-ENOMEM);
1716 pool->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle);
1717 if (IS_ERR(pool->copier)) {
1718 r = PTR_ERR(pool->copier);
1719 *error = "Error creating pool's kcopyd client";
1721 goto bad_kcopyd_client;
1725 * Create singlethreaded workqueue that will service all devices
1726 * that use this metadata.
1728 pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
1730 *error = "Error creating pool's workqueue";
1731 err_p = ERR_PTR(-ENOMEM);
1735 INIT_WORK(&pool->worker, do_worker);
1736 INIT_DELAYED_WORK(&pool->waker, do_waker);
1737 spin_lock_init(&pool->lock);
1738 bio_list_init(&pool->deferred_bios);
1739 bio_list_init(&pool->deferred_flush_bios);
1740 INIT_LIST_HEAD(&pool->prepared_mappings);
1741 INIT_LIST_HEAD(&pool->prepared_discards);
1742 pool->low_water_triggered = 0;
1743 pool->no_free_space = 0;
1744 bio_list_init(&pool->retry_on_resume_list);
1746 pool->shared_read_ds = dm_deferred_set_create();
1747 if (!pool->shared_read_ds) {
1748 *error = "Error creating pool's shared read deferred set";
1749 err_p = ERR_PTR(-ENOMEM);
1750 goto bad_shared_read_ds;
1753 pool->all_io_ds = dm_deferred_set_create();
1754 if (!pool->all_io_ds) {
1755 *error = "Error creating pool's all io deferred set";
1756 err_p = ERR_PTR(-ENOMEM);
1760 pool->next_mapping = NULL;
1761 pool->mapping_pool = mempool_create_slab_pool(MAPPING_POOL_SIZE,
1762 _new_mapping_cache);
1763 if (!pool->mapping_pool) {
1764 *error = "Error creating pool's mapping mempool";
1765 err_p = ERR_PTR(-ENOMEM);
1766 goto bad_mapping_pool;
1769 pool->ref_count = 1;
1770 pool->last_commit_jiffies = jiffies;
1771 pool->pool_md = pool_md;
1772 pool->md_dev = metadata_dev;
1773 __pool_table_insert(pool);
1778 dm_deferred_set_destroy(pool->all_io_ds);
1780 dm_deferred_set_destroy(pool->shared_read_ds);
1782 destroy_workqueue(pool->wq);
1784 dm_kcopyd_client_destroy(pool->copier);
1786 dm_bio_prison_destroy(pool->prison);
1790 if (dm_pool_metadata_close(pmd))
1791 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
1796 static void __pool_inc(struct pool *pool)
1798 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
1802 static void __pool_dec(struct pool *pool)
1804 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
1805 BUG_ON(!pool->ref_count);
1806 if (!--pool->ref_count)
1807 __pool_destroy(pool);
1810 static struct pool *__pool_find(struct mapped_device *pool_md,
1811 struct block_device *metadata_dev,
1812 unsigned long block_size, int read_only,
1813 char **error, int *created)
1815 struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev);
1818 if (pool->pool_md != pool_md) {
1819 *error = "metadata device already in use by a pool";
1820 return ERR_PTR(-EBUSY);
1825 pool = __pool_table_lookup(pool_md);
1827 if (pool->md_dev != metadata_dev) {
1828 *error = "different pool cannot replace a pool";
1829 return ERR_PTR(-EINVAL);
1834 pool = pool_create(pool_md, metadata_dev, block_size, read_only, error);
1842 /*----------------------------------------------------------------
1843 * Pool target methods
1844 *--------------------------------------------------------------*/
1845 static void pool_dtr(struct dm_target *ti)
1847 struct pool_c *pt = ti->private;
1849 mutex_lock(&dm_thin_pool_table.mutex);
1851 unbind_control_target(pt->pool, ti);
1852 __pool_dec(pt->pool);
1853 dm_put_device(ti, pt->metadata_dev);
1854 dm_put_device(ti, pt->data_dev);
1857 mutex_unlock(&dm_thin_pool_table.mutex);
1860 static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf,
1861 struct dm_target *ti)
1865 const char *arg_name;
1867 static struct dm_arg _args[] = {
1868 {0, 3, "Invalid number of pool feature arguments"},
1872 * No feature arguments supplied.
1877 r = dm_read_arg_group(_args, as, &argc, &ti->error);
1881 while (argc && !r) {
1882 arg_name = dm_shift_arg(as);
1885 if (!strcasecmp(arg_name, "skip_block_zeroing"))
1886 pf->zero_new_blocks = false;
1888 else if (!strcasecmp(arg_name, "ignore_discard"))
1889 pf->discard_enabled = false;
1891 else if (!strcasecmp(arg_name, "no_discard_passdown"))
1892 pf->discard_passdown = false;
1894 else if (!strcasecmp(arg_name, "read_only"))
1895 pf->mode = PM_READ_ONLY;
1898 ti->error = "Unrecognised pool feature requested";
1908 * thin-pool <metadata dev> <data dev>
1909 * <data block size (sectors)>
1910 * <low water mark (blocks)>
1911 * [<#feature args> [<arg>]*]
1913 * Optional feature arguments are:
1914 * skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
1915 * ignore_discard: disable discard
1916 * no_discard_passdown: don't pass discards down to the data device
1918 static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv)
1920 int r, pool_created = 0;
1923 struct pool_features pf;
1924 struct dm_arg_set as;
1925 struct dm_dev *data_dev;
1926 unsigned long block_size;
1927 dm_block_t low_water_blocks;
1928 struct dm_dev *metadata_dev;
1929 sector_t metadata_dev_size;
1930 char b[BDEVNAME_SIZE];
1933 * FIXME Remove validation from scope of lock.
1935 mutex_lock(&dm_thin_pool_table.mutex);
1938 ti->error = "Invalid argument count";
1945 r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &metadata_dev);
1947 ti->error = "Error opening metadata block device";
1951 metadata_dev_size = i_size_read(metadata_dev->bdev->bd_inode) >> SECTOR_SHIFT;
1952 if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING)
1953 DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",
1954 bdevname(metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS);
1956 r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev);
1958 ti->error = "Error getting data device";
1962 if (kstrtoul(argv[2], 10, &block_size) || !block_size ||
1963 block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
1964 block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
1965 block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
1966 ti->error = "Invalid block size";
1971 if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) {
1972 ti->error = "Invalid low water mark";
1978 * Set default pool features.
1980 pool_features_init(&pf);
1982 dm_consume_args(&as, 4);
1983 r = parse_pool_features(&as, &pf, ti);
1987 pt = kzalloc(sizeof(*pt), GFP_KERNEL);
1993 pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev,
1994 block_size, pf.mode == PM_READ_ONLY, &ti->error, &pool_created);
2001 * 'pool_created' reflects whether this is the first table load.
2002 * Top level discard support is not allowed to be changed after
2003 * initial load. This would require a pool reload to trigger thin
2006 if (!pool_created && pf.discard_enabled != pool->pf.discard_enabled) {
2007 ti->error = "Discard support cannot be disabled once enabled";
2009 goto out_flags_changed;
2014 pt->metadata_dev = metadata_dev;
2015 pt->data_dev = data_dev;
2016 pt->low_water_blocks = low_water_blocks;
2017 pt->adjusted_pf = pt->requested_pf = pf;
2018 ti->num_flush_bios = 1;
2021 * Only need to enable discards if the pool should pass
2022 * them down to the data device. The thin device's discard
2023 * processing will cause mappings to be removed from the btree.
2025 if (pf.discard_enabled && pf.discard_passdown) {
2026 ti->num_discard_bios = 1;
2029 * Setting 'discards_supported' circumvents the normal
2030 * stacking of discard limits (this keeps the pool and
2031 * thin devices' discard limits consistent).
2033 ti->discards_supported = true;
2034 ti->discard_zeroes_data_unsupported = true;
2038 pt->callbacks.congested_fn = pool_is_congested;
2039 dm_table_add_target_callbacks(ti->table, &pt->callbacks);
2041 mutex_unlock(&dm_thin_pool_table.mutex);
2050 dm_put_device(ti, data_dev);
2052 dm_put_device(ti, metadata_dev);
2054 mutex_unlock(&dm_thin_pool_table.mutex);
2059 static int pool_map(struct dm_target *ti, struct bio *bio)
2062 struct pool_c *pt = ti->private;
2063 struct pool *pool = pt->pool;
2064 unsigned long flags;
2067 * As this is a singleton target, ti->begin is always zero.
2069 spin_lock_irqsave(&pool->lock, flags);
2070 bio->bi_bdev = pt->data_dev->bdev;
2071 r = DM_MAPIO_REMAPPED;
2072 spin_unlock_irqrestore(&pool->lock, flags);
2078 * Retrieves the number of blocks of the data device from
2079 * the superblock and compares it to the actual device size,
2080 * thus resizing the data device in case it has grown.
2082 * This both copes with opening preallocated data devices in the ctr
2083 * being followed by a resume
2085 * calling the resume method individually after userspace has
2086 * grown the data device in reaction to a table event.
2088 static int pool_preresume(struct dm_target *ti)
2091 struct pool_c *pt = ti->private;
2092 struct pool *pool = pt->pool;
2093 sector_t data_size = ti->len;
2094 dm_block_t sb_data_size;
2097 * Take control of the pool object.
2099 r = bind_control_target(pool, ti);
2103 (void) sector_div(data_size, pool->sectors_per_block);
2105 r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
2107 DMERR("failed to retrieve data device size");
2111 if (data_size < sb_data_size) {
2112 DMERR("pool target too small, is %llu blocks (expected %llu)",
2113 (unsigned long long)data_size, sb_data_size);
2116 } else if (data_size > sb_data_size) {
2117 r = dm_pool_resize_data_dev(pool->pmd, data_size);
2119 DMERR("failed to resize data device");
2120 /* FIXME Stricter than necessary: Rollback transaction instead here */
2121 set_pool_mode(pool, PM_READ_ONLY);
2125 (void) commit_or_fallback(pool);
2131 static void pool_resume(struct dm_target *ti)
2133 struct pool_c *pt = ti->private;
2134 struct pool *pool = pt->pool;
2135 unsigned long flags;
2137 spin_lock_irqsave(&pool->lock, flags);
2138 pool->low_water_triggered = 0;
2139 pool->no_free_space = 0;
2140 __requeue_bios(pool);
2141 spin_unlock_irqrestore(&pool->lock, flags);
2143 do_waker(&pool->waker.work);
2146 static void pool_postsuspend(struct dm_target *ti)
2148 struct pool_c *pt = ti->private;
2149 struct pool *pool = pt->pool;
2151 cancel_delayed_work(&pool->waker);
2152 flush_workqueue(pool->wq);
2153 (void) commit_or_fallback(pool);
2156 static int check_arg_count(unsigned argc, unsigned args_required)
2158 if (argc != args_required) {
2159 DMWARN("Message received with %u arguments instead of %u.",
2160 argc, args_required);
2167 static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning)
2169 if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) &&
2170 *dev_id <= MAX_DEV_ID)
2174 DMWARN("Message received with invalid device id: %s", arg);
2179 static int process_create_thin_mesg(unsigned argc, char **argv, struct pool *pool)
2184 r = check_arg_count(argc, 2);
2188 r = read_dev_id(argv[1], &dev_id, 1);
2192 r = dm_pool_create_thin(pool->pmd, dev_id);
2194 DMWARN("Creation of new thinly-provisioned device with id %s failed.",
2202 static int process_create_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2205 dm_thin_id origin_dev_id;
2208 r = check_arg_count(argc, 3);
2212 r = read_dev_id(argv[1], &dev_id, 1);
2216 r = read_dev_id(argv[2], &origin_dev_id, 1);
2220 r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id);
2222 DMWARN("Creation of new snapshot %s of device %s failed.",
2230 static int process_delete_mesg(unsigned argc, char **argv, struct pool *pool)
2235 r = check_arg_count(argc, 2);
2239 r = read_dev_id(argv[1], &dev_id, 1);
2243 r = dm_pool_delete_thin_device(pool->pmd, dev_id);
2245 DMWARN("Deletion of thin device %s failed.", argv[1]);
2250 static int process_set_transaction_id_mesg(unsigned argc, char **argv, struct pool *pool)
2252 dm_thin_id old_id, new_id;
2255 r = check_arg_count(argc, 3);
2259 if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) {
2260 DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]);
2264 if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) {
2265 DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]);
2269 r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id);
2271 DMWARN("Failed to change transaction id from %s to %s.",
2279 static int process_reserve_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2283 r = check_arg_count(argc, 1);
2287 (void) commit_or_fallback(pool);
2289 r = dm_pool_reserve_metadata_snap(pool->pmd);
2291 DMWARN("reserve_metadata_snap message failed.");
2296 static int process_release_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2300 r = check_arg_count(argc, 1);
2304 r = dm_pool_release_metadata_snap(pool->pmd);
2306 DMWARN("release_metadata_snap message failed.");
2312 * Messages supported:
2313 * create_thin <dev_id>
2314 * create_snap <dev_id> <origin_id>
2316 * trim <dev_id> <new_size_in_sectors>
2317 * set_transaction_id <current_trans_id> <new_trans_id>
2318 * reserve_metadata_snap
2319 * release_metadata_snap
2321 static int pool_message(struct dm_target *ti, unsigned argc, char **argv)
2324 struct pool_c *pt = ti->private;
2325 struct pool *pool = pt->pool;
2327 if (!strcasecmp(argv[0], "create_thin"))
2328 r = process_create_thin_mesg(argc, argv, pool);
2330 else if (!strcasecmp(argv[0], "create_snap"))
2331 r = process_create_snap_mesg(argc, argv, pool);
2333 else if (!strcasecmp(argv[0], "delete"))
2334 r = process_delete_mesg(argc, argv, pool);
2336 else if (!strcasecmp(argv[0], "set_transaction_id"))
2337 r = process_set_transaction_id_mesg(argc, argv, pool);
2339 else if (!strcasecmp(argv[0], "reserve_metadata_snap"))
2340 r = process_reserve_metadata_snap_mesg(argc, argv, pool);
2342 else if (!strcasecmp(argv[0], "release_metadata_snap"))
2343 r = process_release_metadata_snap_mesg(argc, argv, pool);
2346 DMWARN("Unrecognised thin pool target message received: %s", argv[0]);
2349 (void) commit_or_fallback(pool);
2354 static void emit_flags(struct pool_features *pf, char *result,
2355 unsigned sz, unsigned maxlen)
2357 unsigned count = !pf->zero_new_blocks + !pf->discard_enabled +
2358 !pf->discard_passdown + (pf->mode == PM_READ_ONLY);
2359 DMEMIT("%u ", count);
2361 if (!pf->zero_new_blocks)
2362 DMEMIT("skip_block_zeroing ");
2364 if (!pf->discard_enabled)
2365 DMEMIT("ignore_discard ");
2367 if (!pf->discard_passdown)
2368 DMEMIT("no_discard_passdown ");
2370 if (pf->mode == PM_READ_ONLY)
2371 DMEMIT("read_only ");
2376 * <transaction id> <used metadata sectors>/<total metadata sectors>
2377 * <used data sectors>/<total data sectors> <held metadata root>
2379 static void pool_status(struct dm_target *ti, status_type_t type,
2380 unsigned status_flags, char *result, unsigned maxlen)
2384 uint64_t transaction_id;
2385 dm_block_t nr_free_blocks_data;
2386 dm_block_t nr_free_blocks_metadata;
2387 dm_block_t nr_blocks_data;
2388 dm_block_t nr_blocks_metadata;
2389 dm_block_t held_root;
2390 char buf[BDEVNAME_SIZE];
2391 char buf2[BDEVNAME_SIZE];
2392 struct pool_c *pt = ti->private;
2393 struct pool *pool = pt->pool;
2396 case STATUSTYPE_INFO:
2397 if (get_pool_mode(pool) == PM_FAIL) {
2402 /* Commit to ensure statistics aren't out-of-date */
2403 if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
2404 (void) commit_or_fallback(pool);
2406 r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id);
2408 DMERR("dm_pool_get_metadata_transaction_id returned %d", r);
2412 r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free_blocks_metadata);
2414 DMERR("dm_pool_get_free_metadata_block_count returned %d", r);
2418 r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
2420 DMERR("dm_pool_get_metadata_dev_size returned %d", r);
2424 r = dm_pool_get_free_block_count(pool->pmd, &nr_free_blocks_data);
2426 DMERR("dm_pool_get_free_block_count returned %d", r);
2430 r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
2432 DMERR("dm_pool_get_data_dev_size returned %d", r);
2436 r = dm_pool_get_metadata_snap(pool->pmd, &held_root);
2438 DMERR("dm_pool_get_metadata_snap returned %d", r);
2442 DMEMIT("%llu %llu/%llu %llu/%llu ",
2443 (unsigned long long)transaction_id,
2444 (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata),
2445 (unsigned long long)nr_blocks_metadata,
2446 (unsigned long long)(nr_blocks_data - nr_free_blocks_data),
2447 (unsigned long long)nr_blocks_data);
2450 DMEMIT("%llu ", held_root);
2454 if (pool->pf.mode == PM_READ_ONLY)
2459 if (!pool->pf.discard_enabled)
2460 DMEMIT("ignore_discard");
2461 else if (pool->pf.discard_passdown)
2462 DMEMIT("discard_passdown");
2464 DMEMIT("no_discard_passdown");
2468 case STATUSTYPE_TABLE:
2469 DMEMIT("%s %s %lu %llu ",
2470 format_dev_t(buf, pt->metadata_dev->bdev->bd_dev),
2471 format_dev_t(buf2, pt->data_dev->bdev->bd_dev),
2472 (unsigned long)pool->sectors_per_block,
2473 (unsigned long long)pt->low_water_blocks);
2474 emit_flags(&pt->requested_pf, result, sz, maxlen);
2483 static int pool_iterate_devices(struct dm_target *ti,
2484 iterate_devices_callout_fn fn, void *data)
2486 struct pool_c *pt = ti->private;
2488 return fn(ti, pt->data_dev, 0, ti->len, data);
2491 static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
2492 struct bio_vec *biovec, int max_size)
2494 struct pool_c *pt = ti->private;
2495 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
2497 if (!q->merge_bvec_fn)
2500 bvm->bi_bdev = pt->data_dev->bdev;
2502 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
2505 static void set_discard_limits(struct pool_c *pt, struct queue_limits *limits)
2507 struct pool *pool = pt->pool;
2508 struct queue_limits *data_limits;
2510 limits->max_discard_sectors = pool->sectors_per_block;
2513 * discard_granularity is just a hint, and not enforced.
2515 if (pt->adjusted_pf.discard_passdown) {
2516 data_limits = &bdev_get_queue(pt->data_dev->bdev)->limits;
2517 limits->discard_granularity = data_limits->discard_granularity;
2519 limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
2522 static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
2524 struct pool_c *pt = ti->private;
2525 struct pool *pool = pt->pool;
2527 blk_limits_io_min(limits, 0);
2528 blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
2531 * pt->adjusted_pf is a staging area for the actual features to use.
2532 * They get transferred to the live pool in bind_control_target()
2533 * called from pool_preresume().
2535 if (!pt->adjusted_pf.discard_enabled)
2538 disable_passdown_if_not_supported(pt);
2540 set_discard_limits(pt, limits);
2543 static struct target_type pool_target = {
2544 .name = "thin-pool",
2545 .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
2546 DM_TARGET_IMMUTABLE,
2547 .version = {1, 6, 1},
2548 .module = THIS_MODULE,
2552 .postsuspend = pool_postsuspend,
2553 .preresume = pool_preresume,
2554 .resume = pool_resume,
2555 .message = pool_message,
2556 .status = pool_status,
2557 .merge = pool_merge,
2558 .iterate_devices = pool_iterate_devices,
2559 .io_hints = pool_io_hints,
2562 /*----------------------------------------------------------------
2563 * Thin target methods
2564 *--------------------------------------------------------------*/
2565 static void thin_dtr(struct dm_target *ti)
2567 struct thin_c *tc = ti->private;
2569 mutex_lock(&dm_thin_pool_table.mutex);
2571 __pool_dec(tc->pool);
2572 dm_pool_close_thin_device(tc->td);
2573 dm_put_device(ti, tc->pool_dev);
2575 dm_put_device(ti, tc->origin_dev);
2578 mutex_unlock(&dm_thin_pool_table.mutex);
2582 * Thin target parameters:
2584 * <pool_dev> <dev_id> [origin_dev]
2586 * pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
2587 * dev_id: the internal device identifier
2588 * origin_dev: a device external to the pool that should act as the origin
2590 * If the pool device has discards disabled, they get disabled for the thin
2593 static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
2597 struct dm_dev *pool_dev, *origin_dev;
2598 struct mapped_device *pool_md;
2600 mutex_lock(&dm_thin_pool_table.mutex);
2602 if (argc != 2 && argc != 3) {
2603 ti->error = "Invalid argument count";
2608 tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL);
2610 ti->error = "Out of memory";
2616 r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev);
2618 ti->error = "Error opening origin device";
2619 goto bad_origin_dev;
2621 tc->origin_dev = origin_dev;
2624 r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev);
2626 ti->error = "Error opening pool device";
2629 tc->pool_dev = pool_dev;
2631 if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) {
2632 ti->error = "Invalid device id";
2637 pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev);
2639 ti->error = "Couldn't get pool mapped device";
2644 tc->pool = __pool_table_lookup(pool_md);
2646 ti->error = "Couldn't find pool object";
2648 goto bad_pool_lookup;
2650 __pool_inc(tc->pool);
2652 if (get_pool_mode(tc->pool) == PM_FAIL) {
2653 ti->error = "Couldn't open thin device, Pool is in fail mode";
2657 r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td);
2659 ti->error = "Couldn't open thin internal device";
2663 r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
2667 ti->num_flush_bios = 1;
2668 ti->flush_supported = true;
2669 ti->per_bio_data_size = sizeof(struct dm_thin_endio_hook);
2671 /* In case the pool supports discards, pass them on. */
2672 if (tc->pool->pf.discard_enabled) {
2673 ti->discards_supported = true;
2674 ti->num_discard_bios = 1;
2675 ti->discard_zeroes_data_unsupported = true;
2676 /* Discard bios must be split on a block boundary */
2677 ti->split_discard_bios = true;
2682 mutex_unlock(&dm_thin_pool_table.mutex);
2687 __pool_dec(tc->pool);
2691 dm_put_device(ti, tc->pool_dev);
2694 dm_put_device(ti, tc->origin_dev);
2698 mutex_unlock(&dm_thin_pool_table.mutex);
2703 static int thin_map(struct dm_target *ti, struct bio *bio)
2705 bio->bi_sector = dm_target_offset(ti, bio->bi_sector);
2707 return thin_bio_map(ti, bio);
2710 static int thin_endio(struct dm_target *ti, struct bio *bio, int err)
2712 unsigned long flags;
2713 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
2714 struct list_head work;
2715 struct dm_thin_new_mapping *m, *tmp;
2716 struct pool *pool = h->tc->pool;
2718 if (h->shared_read_entry) {
2719 INIT_LIST_HEAD(&work);
2720 dm_deferred_entry_dec(h->shared_read_entry, &work);
2722 spin_lock_irqsave(&pool->lock, flags);
2723 list_for_each_entry_safe(m, tmp, &work, list) {
2726 __maybe_add_mapping(m);
2728 spin_unlock_irqrestore(&pool->lock, flags);
2731 if (h->all_io_entry) {
2732 INIT_LIST_HEAD(&work);
2733 dm_deferred_entry_dec(h->all_io_entry, &work);
2734 if (!list_empty(&work)) {
2735 spin_lock_irqsave(&pool->lock, flags);
2736 list_for_each_entry_safe(m, tmp, &work, list)
2737 list_add(&m->list, &pool->prepared_discards);
2738 spin_unlock_irqrestore(&pool->lock, flags);
2746 static void thin_postsuspend(struct dm_target *ti)
2748 if (dm_noflush_suspending(ti))
2749 requeue_io((struct thin_c *)ti->private);
2753 * <nr mapped sectors> <highest mapped sector>
2755 static void thin_status(struct dm_target *ti, status_type_t type,
2756 unsigned status_flags, char *result, unsigned maxlen)
2760 dm_block_t mapped, highest;
2761 char buf[BDEVNAME_SIZE];
2762 struct thin_c *tc = ti->private;
2764 if (get_pool_mode(tc->pool) == PM_FAIL) {
2773 case STATUSTYPE_INFO:
2774 r = dm_thin_get_mapped_count(tc->td, &mapped);
2776 DMERR("dm_thin_get_mapped_count returned %d", r);
2780 r = dm_thin_get_highest_mapped_block(tc->td, &highest);
2782 DMERR("dm_thin_get_highest_mapped_block returned %d", r);
2786 DMEMIT("%llu ", mapped * tc->pool->sectors_per_block);
2788 DMEMIT("%llu", ((highest + 1) *
2789 tc->pool->sectors_per_block) - 1);
2794 case STATUSTYPE_TABLE:
2796 format_dev_t(buf, tc->pool_dev->bdev->bd_dev),
2797 (unsigned long) tc->dev_id);
2799 DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev));
2810 static int thin_iterate_devices(struct dm_target *ti,
2811 iterate_devices_callout_fn fn, void *data)
2814 struct thin_c *tc = ti->private;
2815 struct pool *pool = tc->pool;
2818 * We can't call dm_pool_get_data_dev_size() since that blocks. So
2819 * we follow a more convoluted path through to the pool's target.
2822 return 0; /* nothing is bound */
2824 blocks = pool->ti->len;
2825 (void) sector_div(blocks, pool->sectors_per_block);
2827 return fn(ti, tc->pool_dev, 0, pool->sectors_per_block * blocks, data);
2832 static struct target_type thin_target = {
2834 .version = {1, 7, 1},
2835 .module = THIS_MODULE,
2839 .end_io = thin_endio,
2840 .postsuspend = thin_postsuspend,
2841 .status = thin_status,
2842 .iterate_devices = thin_iterate_devices,
2845 /*----------------------------------------------------------------*/
2847 static int __init dm_thin_init(void)
2853 r = dm_register_target(&thin_target);
2857 r = dm_register_target(&pool_target);
2859 goto bad_pool_target;
2863 _new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
2864 if (!_new_mapping_cache)
2865 goto bad_new_mapping_cache;
2869 bad_new_mapping_cache:
2870 dm_unregister_target(&pool_target);
2872 dm_unregister_target(&thin_target);
2877 static void dm_thin_exit(void)
2879 dm_unregister_target(&thin_target);
2880 dm_unregister_target(&pool_target);
2882 kmem_cache_destroy(_new_mapping_cache);
2885 module_init(dm_thin_init);
2886 module_exit(dm_thin_exit);
2888 MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
2889 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
2890 MODULE_LICENSE("GPL");