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/log2.h>
15 #include <linux/list.h>
16 #include <linux/rculist.h>
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/sort.h>
21 #include <linux/rbtree.h>
23 #define DM_MSG_PREFIX "thin"
28 #define ENDIO_HOOK_POOL_SIZE 1024
29 #define MAPPING_POOL_SIZE 1024
30 #define COMMIT_PERIOD HZ
31 #define NO_SPACE_TIMEOUT_SECS 60
33 static unsigned no_space_timeout_secs
= NO_SPACE_TIMEOUT_SECS
;
35 DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle
,
36 "A percentage of time allocated for copy on write");
39 * The block size of the device holding pool data must be
40 * between 64KB and 1GB.
42 #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
43 #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
46 * Device id is restricted to 24 bits.
48 #define MAX_DEV_ID ((1 << 24) - 1)
51 * How do we handle breaking sharing of data blocks?
52 * =================================================
54 * We use a standard copy-on-write btree to store the mappings for the
55 * devices (note I'm talking about copy-on-write of the metadata here, not
56 * the data). When you take an internal snapshot you clone the root node
57 * of the origin btree. After this there is no concept of an origin or a
58 * snapshot. They are just two device trees that happen to point to the
61 * When we get a write in we decide if it's to a shared data block using
62 * some timestamp magic. If it is, we have to break sharing.
64 * Let's say we write to a shared block in what was the origin. The
67 * i) plug io further to this physical block. (see bio_prison code).
69 * ii) quiesce any read io to that shared data block. Obviously
70 * including all devices that share this block. (see dm_deferred_set code)
72 * iii) copy the data block to a newly allocate block. This step can be
73 * missed out if the io covers the block. (schedule_copy).
75 * iv) insert the new mapping into the origin's btree
76 * (process_prepared_mapping). This act of inserting breaks some
77 * sharing of btree nodes between the two devices. Breaking sharing only
78 * effects the btree of that specific device. Btrees for the other
79 * devices that share the block never change. The btree for the origin
80 * device as it was after the last commit is untouched, ie. we're using
81 * persistent data structures in the functional programming sense.
83 * v) unplug io to this physical block, including the io that triggered
84 * the breaking of sharing.
86 * Steps (ii) and (iii) occur in parallel.
88 * The metadata _doesn't_ need to be committed before the io continues. We
89 * get away with this because the io is always written to a _new_ block.
90 * If there's a crash, then:
92 * - The origin mapping will point to the old origin block (the shared
93 * one). This will contain the data as it was before the io that triggered
94 * the breaking of sharing came in.
96 * - The snap mapping still points to the old block. As it would after
99 * The downside of this scheme is the timestamp magic isn't perfect, and
100 * will continue to think that data block in the snapshot device is shared
101 * even after the write to the origin has broken sharing. I suspect data
102 * blocks will typically be shared by many different devices, so we're
103 * breaking sharing n + 1 times, rather than n, where n is the number of
104 * devices that reference this data block. At the moment I think the
105 * benefits far, far outweigh the disadvantages.
108 /*----------------------------------------------------------------*/
113 static void build_data_key(struct dm_thin_device
*td
,
114 dm_block_t b
, struct dm_cell_key
*key
)
117 key
->dev
= dm_thin_dev_id(td
);
118 key
->block_begin
= b
;
119 key
->block_end
= b
+ 1ULL;
122 static void build_virtual_key(struct dm_thin_device
*td
, dm_block_t b
,
123 struct dm_cell_key
*key
)
126 key
->dev
= dm_thin_dev_id(td
);
127 key
->block_begin
= b
;
128 key
->block_end
= b
+ 1ULL;
131 /*----------------------------------------------------------------*/
133 #define THROTTLE_THRESHOLD (1 * HZ)
136 struct rw_semaphore lock
;
137 unsigned long threshold
;
138 bool throttle_applied
;
141 static void throttle_init(struct throttle
*t
)
143 init_rwsem(&t
->lock
);
144 t
->throttle_applied
= false;
147 static void throttle_work_start(struct throttle
*t
)
149 t
->threshold
= jiffies
+ THROTTLE_THRESHOLD
;
152 static void throttle_work_update(struct throttle
*t
)
154 if (!t
->throttle_applied
&& jiffies
> t
->threshold
) {
155 down_write(&t
->lock
);
156 t
->throttle_applied
= true;
160 static void throttle_work_complete(struct throttle
*t
)
162 if (t
->throttle_applied
) {
163 t
->throttle_applied
= false;
168 static void throttle_lock(struct throttle
*t
)
173 static void throttle_unlock(struct throttle
*t
)
178 /*----------------------------------------------------------------*/
181 * A pool device ties together a metadata device and a data device. It
182 * also provides the interface for creating and destroying internal
185 struct dm_thin_new_mapping
;
188 * The pool runs in 4 modes. Ordered in degraded order for comparisons.
191 PM_WRITE
, /* metadata may be changed */
192 PM_OUT_OF_DATA_SPACE
, /* metadata may be changed, though data may not be allocated */
193 PM_READ_ONLY
, /* metadata may not be changed */
194 PM_FAIL
, /* all I/O fails */
197 struct pool_features
{
200 bool zero_new_blocks
:1;
201 bool discard_enabled
:1;
202 bool discard_passdown
:1;
203 bool error_if_no_space
:1;
207 typedef void (*process_bio_fn
)(struct thin_c
*tc
, struct bio
*bio
);
208 typedef void (*process_cell_fn
)(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
);
209 typedef void (*process_mapping_fn
)(struct dm_thin_new_mapping
*m
);
211 #define CELL_SORT_ARRAY_SIZE 8192
214 struct list_head list
;
215 struct dm_target
*ti
; /* Only set if a pool target is bound */
217 struct mapped_device
*pool_md
;
218 struct block_device
*md_dev
;
219 struct dm_pool_metadata
*pmd
;
221 dm_block_t low_water_blocks
;
222 uint32_t sectors_per_block
;
223 int sectors_per_block_shift
;
225 struct pool_features pf
;
226 bool low_water_triggered
:1; /* A dm event has been sent */
229 struct dm_bio_prison
*prison
;
230 struct dm_kcopyd_client
*copier
;
232 struct workqueue_struct
*wq
;
233 struct throttle throttle
;
234 struct work_struct worker
;
235 struct delayed_work waker
;
236 struct delayed_work no_space_timeout
;
238 unsigned long last_commit_jiffies
;
242 struct bio_list deferred_flush_bios
;
243 struct list_head prepared_mappings
;
244 struct list_head prepared_discards
;
245 struct list_head active_thins
;
247 struct dm_deferred_set
*shared_read_ds
;
248 struct dm_deferred_set
*all_io_ds
;
250 struct dm_thin_new_mapping
*next_mapping
;
251 mempool_t
*mapping_pool
;
253 process_bio_fn process_bio
;
254 process_bio_fn process_discard
;
256 process_cell_fn process_cell
;
257 process_cell_fn process_discard_cell
;
259 process_mapping_fn process_prepared_mapping
;
260 process_mapping_fn process_prepared_discard
;
262 struct dm_bio_prison_cell
*cell_sort_array
[CELL_SORT_ARRAY_SIZE
];
265 static enum pool_mode
get_pool_mode(struct pool
*pool
);
266 static void metadata_operation_failed(struct pool
*pool
, const char *op
, int r
);
269 * Target context for a pool.
272 struct dm_target
*ti
;
274 struct dm_dev
*data_dev
;
275 struct dm_dev
*metadata_dev
;
276 struct dm_target_callbacks callbacks
;
278 dm_block_t low_water_blocks
;
279 struct pool_features requested_pf
; /* Features requested during table load */
280 struct pool_features adjusted_pf
; /* Features used after adjusting for constituent devices */
284 * Target context for a thin.
287 struct list_head list
;
288 struct dm_dev
*pool_dev
;
289 struct dm_dev
*origin_dev
;
290 sector_t origin_size
;
294 struct dm_thin_device
*td
;
295 struct mapped_device
*thin_md
;
299 struct list_head deferred_cells
;
300 struct bio_list deferred_bio_list
;
301 struct bio_list retry_on_resume_list
;
302 struct rb_root sort_bio_list
; /* sorted list of deferred bios */
305 * Ensures the thin is not destroyed until the worker has finished
306 * iterating the active_thins list.
309 struct completion can_destroy
;
312 /*----------------------------------------------------------------*/
315 * wake_worker() is used when new work is queued and when pool_resume is
316 * ready to continue deferred IO processing.
318 static void wake_worker(struct pool
*pool
)
320 queue_work(pool
->wq
, &pool
->worker
);
323 /*----------------------------------------------------------------*/
325 static int bio_detain(struct pool
*pool
, struct dm_cell_key
*key
, struct bio
*bio
,
326 struct dm_bio_prison_cell
**cell_result
)
329 struct dm_bio_prison_cell
*cell_prealloc
;
332 * Allocate a cell from the prison's mempool.
333 * This might block but it can't fail.
335 cell_prealloc
= dm_bio_prison_alloc_cell(pool
->prison
, GFP_NOIO
);
337 r
= dm_bio_detain(pool
->prison
, key
, bio
, cell_prealloc
, cell_result
);
340 * We reused an old cell; we can get rid of
343 dm_bio_prison_free_cell(pool
->prison
, cell_prealloc
);
348 static void cell_release(struct pool
*pool
,
349 struct dm_bio_prison_cell
*cell
,
350 struct bio_list
*bios
)
352 dm_cell_release(pool
->prison
, cell
, bios
);
353 dm_bio_prison_free_cell(pool
->prison
, cell
);
356 static void cell_visit_release(struct pool
*pool
,
357 void (*fn
)(void *, struct dm_bio_prison_cell
*),
359 struct dm_bio_prison_cell
*cell
)
361 dm_cell_visit_release(pool
->prison
, fn
, context
, cell
);
362 dm_bio_prison_free_cell(pool
->prison
, cell
);
365 static void cell_release_no_holder(struct pool
*pool
,
366 struct dm_bio_prison_cell
*cell
,
367 struct bio_list
*bios
)
369 dm_cell_release_no_holder(pool
->prison
, cell
, bios
);
370 dm_bio_prison_free_cell(pool
->prison
, cell
);
373 static void cell_error_with_code(struct pool
*pool
,
374 struct dm_bio_prison_cell
*cell
, int error_code
)
376 dm_cell_error(pool
->prison
, cell
, error_code
);
377 dm_bio_prison_free_cell(pool
->prison
, cell
);
380 static void cell_error(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
382 cell_error_with_code(pool
, cell
, -EIO
);
385 static void cell_success(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
387 cell_error_with_code(pool
, cell
, 0);
390 static void cell_requeue(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
392 cell_error_with_code(pool
, cell
, DM_ENDIO_REQUEUE
);
395 /*----------------------------------------------------------------*/
398 * A global list of pools that uses a struct mapped_device as a key.
400 static struct dm_thin_pool_table
{
402 struct list_head pools
;
403 } dm_thin_pool_table
;
405 static void pool_table_init(void)
407 mutex_init(&dm_thin_pool_table
.mutex
);
408 INIT_LIST_HEAD(&dm_thin_pool_table
.pools
);
411 static void __pool_table_insert(struct pool
*pool
)
413 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
414 list_add(&pool
->list
, &dm_thin_pool_table
.pools
);
417 static void __pool_table_remove(struct pool
*pool
)
419 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
420 list_del(&pool
->list
);
423 static struct pool
*__pool_table_lookup(struct mapped_device
*md
)
425 struct pool
*pool
= NULL
, *tmp
;
427 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
429 list_for_each_entry(tmp
, &dm_thin_pool_table
.pools
, list
) {
430 if (tmp
->pool_md
== md
) {
439 static struct pool
*__pool_table_lookup_metadata_dev(struct block_device
*md_dev
)
441 struct pool
*pool
= NULL
, *tmp
;
443 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
445 list_for_each_entry(tmp
, &dm_thin_pool_table
.pools
, list
) {
446 if (tmp
->md_dev
== md_dev
) {
455 /*----------------------------------------------------------------*/
457 struct dm_thin_endio_hook
{
459 struct dm_deferred_entry
*shared_read_entry
;
460 struct dm_deferred_entry
*all_io_entry
;
461 struct dm_thin_new_mapping
*overwrite_mapping
;
462 struct rb_node rb_node
;
465 static void __merge_bio_list(struct bio_list
*bios
, struct bio_list
*master
)
467 bio_list_merge(bios
, master
);
468 bio_list_init(master
);
471 static void error_bio_list(struct bio_list
*bios
, int error
)
475 while ((bio
= bio_list_pop(bios
)))
476 bio_endio(bio
, error
);
479 static void error_thin_bio_list(struct thin_c
*tc
, struct bio_list
*master
, int error
)
481 struct bio_list bios
;
484 bio_list_init(&bios
);
486 spin_lock_irqsave(&tc
->lock
, flags
);
487 __merge_bio_list(&bios
, master
);
488 spin_unlock_irqrestore(&tc
->lock
, flags
);
490 error_bio_list(&bios
, error
);
493 static void requeue_deferred_cells(struct thin_c
*tc
)
495 struct pool
*pool
= tc
->pool
;
497 struct list_head cells
;
498 struct dm_bio_prison_cell
*cell
, *tmp
;
500 INIT_LIST_HEAD(&cells
);
502 spin_lock_irqsave(&tc
->lock
, flags
);
503 list_splice_init(&tc
->deferred_cells
, &cells
);
504 spin_unlock_irqrestore(&tc
->lock
, flags
);
506 list_for_each_entry_safe(cell
, tmp
, &cells
, user_list
)
507 cell_requeue(pool
, cell
);
510 static void requeue_io(struct thin_c
*tc
)
512 struct bio_list bios
;
515 bio_list_init(&bios
);
517 spin_lock_irqsave(&tc
->lock
, flags
);
518 __merge_bio_list(&bios
, &tc
->deferred_bio_list
);
519 __merge_bio_list(&bios
, &tc
->retry_on_resume_list
);
520 spin_unlock_irqrestore(&tc
->lock
, flags
);
522 error_bio_list(&bios
, DM_ENDIO_REQUEUE
);
523 requeue_deferred_cells(tc
);
526 static void error_retry_list(struct pool
*pool
)
531 list_for_each_entry_rcu(tc
, &pool
->active_thins
, list
)
532 error_thin_bio_list(tc
, &tc
->retry_on_resume_list
, -EIO
);
537 * This section of code contains the logic for processing a thin device's IO.
538 * Much of the code depends on pool object resources (lists, workqueues, etc)
539 * but most is exclusively called from the thin target rather than the thin-pool
543 static bool block_size_is_power_of_two(struct pool
*pool
)
545 return pool
->sectors_per_block_shift
>= 0;
548 static dm_block_t
get_bio_block(struct thin_c
*tc
, struct bio
*bio
)
550 struct pool
*pool
= tc
->pool
;
551 sector_t block_nr
= bio
->bi_iter
.bi_sector
;
553 if (block_size_is_power_of_two(pool
))
554 block_nr
>>= pool
->sectors_per_block_shift
;
556 (void) sector_div(block_nr
, pool
->sectors_per_block
);
561 static void remap(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
)
563 struct pool
*pool
= tc
->pool
;
564 sector_t bi_sector
= bio
->bi_iter
.bi_sector
;
566 bio
->bi_bdev
= tc
->pool_dev
->bdev
;
567 if (block_size_is_power_of_two(pool
))
568 bio
->bi_iter
.bi_sector
=
569 (block
<< pool
->sectors_per_block_shift
) |
570 (bi_sector
& (pool
->sectors_per_block
- 1));
572 bio
->bi_iter
.bi_sector
= (block
* pool
->sectors_per_block
) +
573 sector_div(bi_sector
, pool
->sectors_per_block
);
576 static void remap_to_origin(struct thin_c
*tc
, struct bio
*bio
)
578 bio
->bi_bdev
= tc
->origin_dev
->bdev
;
581 static int bio_triggers_commit(struct thin_c
*tc
, struct bio
*bio
)
583 return (bio
->bi_rw
& (REQ_FLUSH
| REQ_FUA
)) &&
584 dm_thin_changed_this_transaction(tc
->td
);
587 static void inc_all_io_entry(struct pool
*pool
, struct bio
*bio
)
589 struct dm_thin_endio_hook
*h
;
591 if (bio
->bi_rw
& REQ_DISCARD
)
594 h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
595 h
->all_io_entry
= dm_deferred_entry_inc(pool
->all_io_ds
);
598 static void issue(struct thin_c
*tc
, struct bio
*bio
)
600 struct pool
*pool
= tc
->pool
;
603 if (!bio_triggers_commit(tc
, bio
)) {
604 generic_make_request(bio
);
609 * Complete bio with an error if earlier I/O caused changes to
610 * the metadata that can't be committed e.g, due to I/O errors
611 * on the metadata device.
613 if (dm_thin_aborted_changes(tc
->td
)) {
619 * Batch together any bios that trigger commits and then issue a
620 * single commit for them in process_deferred_bios().
622 spin_lock_irqsave(&pool
->lock
, flags
);
623 bio_list_add(&pool
->deferred_flush_bios
, bio
);
624 spin_unlock_irqrestore(&pool
->lock
, flags
);
627 static void remap_to_origin_and_issue(struct thin_c
*tc
, struct bio
*bio
)
629 remap_to_origin(tc
, bio
);
633 static void remap_and_issue(struct thin_c
*tc
, struct bio
*bio
,
636 remap(tc
, bio
, block
);
640 /*----------------------------------------------------------------*/
643 * Bio endio functions.
645 struct dm_thin_new_mapping
{
646 struct list_head list
;
649 bool definitely_not_shared
:1;
652 * Track quiescing, copying and zeroing preparation actions. When this
653 * counter hits zero the block is prepared and can be inserted into the
656 atomic_t prepare_actions
;
660 dm_block_t virt_block
;
661 dm_block_t data_block
;
662 struct dm_bio_prison_cell
*cell
, *cell2
;
665 * If the bio covers the whole area of a block then we can avoid
666 * zeroing or copying. Instead this bio is hooked. The bio will
667 * still be in the cell, so care has to be taken to avoid issuing
671 bio_end_io_t
*saved_bi_end_io
;
674 static void __complete_mapping_preparation(struct dm_thin_new_mapping
*m
)
676 struct pool
*pool
= m
->tc
->pool
;
678 if (atomic_dec_and_test(&m
->prepare_actions
)) {
679 list_add_tail(&m
->list
, &pool
->prepared_mappings
);
684 static void complete_mapping_preparation(struct dm_thin_new_mapping
*m
)
687 struct pool
*pool
= m
->tc
->pool
;
689 spin_lock_irqsave(&pool
->lock
, flags
);
690 __complete_mapping_preparation(m
);
691 spin_unlock_irqrestore(&pool
->lock
, flags
);
694 static void copy_complete(int read_err
, unsigned long write_err
, void *context
)
696 struct dm_thin_new_mapping
*m
= context
;
698 m
->err
= read_err
|| write_err
? -EIO
: 0;
699 complete_mapping_preparation(m
);
702 static void overwrite_endio(struct bio
*bio
, int err
)
704 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
705 struct dm_thin_new_mapping
*m
= h
->overwrite_mapping
;
708 complete_mapping_preparation(m
);
711 /*----------------------------------------------------------------*/
718 * Prepared mapping jobs.
722 * This sends the bios in the cell, except the original holder, back
723 * to the deferred_bios list.
725 static void cell_defer_no_holder(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
727 struct pool
*pool
= tc
->pool
;
730 spin_lock_irqsave(&tc
->lock
, flags
);
731 cell_release_no_holder(pool
, cell
, &tc
->deferred_bio_list
);
732 spin_unlock_irqrestore(&tc
->lock
, flags
);
737 static void thin_defer_bio(struct thin_c
*tc
, struct bio
*bio
);
741 struct bio_list defer_bios
;
742 struct bio_list issue_bios
;
745 static void __inc_remap_and_issue_cell(void *context
,
746 struct dm_bio_prison_cell
*cell
)
748 struct remap_info
*info
= context
;
751 while ((bio
= bio_list_pop(&cell
->bios
))) {
752 if (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
))
753 bio_list_add(&info
->defer_bios
, bio
);
755 inc_all_io_entry(info
->tc
->pool
, bio
);
758 * We can't issue the bios with the bio prison lock
759 * held, so we add them to a list to issue on
760 * return from this function.
762 bio_list_add(&info
->issue_bios
, bio
);
767 static void inc_remap_and_issue_cell(struct thin_c
*tc
,
768 struct dm_bio_prison_cell
*cell
,
772 struct remap_info info
;
775 bio_list_init(&info
.defer_bios
);
776 bio_list_init(&info
.issue_bios
);
779 * We have to be careful to inc any bios we're about to issue
780 * before the cell is released, and avoid a race with new bios
781 * being added to the cell.
783 cell_visit_release(tc
->pool
, __inc_remap_and_issue_cell
,
786 while ((bio
= bio_list_pop(&info
.defer_bios
)))
787 thin_defer_bio(tc
, bio
);
789 while ((bio
= bio_list_pop(&info
.issue_bios
)))
790 remap_and_issue(info
.tc
, bio
, block
);
793 static void process_prepared_mapping_fail(struct dm_thin_new_mapping
*m
)
796 m
->bio
->bi_end_io
= m
->saved_bi_end_io
;
797 atomic_inc(&m
->bio
->bi_remaining
);
799 cell_error(m
->tc
->pool
, m
->cell
);
801 mempool_free(m
, m
->tc
->pool
->mapping_pool
);
804 static void process_prepared_mapping(struct dm_thin_new_mapping
*m
)
806 struct thin_c
*tc
= m
->tc
;
807 struct pool
*pool
= tc
->pool
;
813 bio
->bi_end_io
= m
->saved_bi_end_io
;
814 atomic_inc(&bio
->bi_remaining
);
818 cell_error(pool
, m
->cell
);
823 * Commit the prepared block into the mapping btree.
824 * Any I/O for this block arriving after this point will get
825 * remapped to it directly.
827 r
= dm_thin_insert_block(tc
->td
, m
->virt_block
, m
->data_block
);
829 metadata_operation_failed(pool
, "dm_thin_insert_block", r
);
830 cell_error(pool
, m
->cell
);
835 * Release any bios held while the block was being provisioned.
836 * If we are processing a write bio that completely covers the block,
837 * we already processed it so can ignore it now when processing
838 * the bios in the cell.
841 inc_remap_and_issue_cell(tc
, m
->cell
, m
->data_block
);
844 inc_all_io_entry(tc
->pool
, m
->cell
->holder
);
845 remap_and_issue(tc
, m
->cell
->holder
, m
->data_block
);
846 inc_remap_and_issue_cell(tc
, m
->cell
, m
->data_block
);
851 mempool_free(m
, pool
->mapping_pool
);
854 static void process_prepared_discard_fail(struct dm_thin_new_mapping
*m
)
856 struct thin_c
*tc
= m
->tc
;
858 bio_io_error(m
->bio
);
859 cell_defer_no_holder(tc
, m
->cell
);
860 cell_defer_no_holder(tc
, m
->cell2
);
861 mempool_free(m
, tc
->pool
->mapping_pool
);
864 static void process_prepared_discard_passdown(struct dm_thin_new_mapping
*m
)
866 struct thin_c
*tc
= m
->tc
;
868 inc_all_io_entry(tc
->pool
, m
->bio
);
869 cell_defer_no_holder(tc
, m
->cell
);
870 cell_defer_no_holder(tc
, m
->cell2
);
873 if (m
->definitely_not_shared
)
874 remap_and_issue(tc
, m
->bio
, m
->data_block
);
877 if (dm_pool_block_is_used(tc
->pool
->pmd
, m
->data_block
, &used
) || used
)
878 bio_endio(m
->bio
, 0);
880 remap_and_issue(tc
, m
->bio
, m
->data_block
);
883 bio_endio(m
->bio
, 0);
885 mempool_free(m
, tc
->pool
->mapping_pool
);
888 static void process_prepared_discard(struct dm_thin_new_mapping
*m
)
891 struct thin_c
*tc
= m
->tc
;
893 r
= dm_thin_remove_block(tc
->td
, m
->virt_block
);
895 DMERR_LIMIT("dm_thin_remove_block() failed");
897 process_prepared_discard_passdown(m
);
900 static void process_prepared(struct pool
*pool
, struct list_head
*head
,
901 process_mapping_fn
*fn
)
904 struct list_head maps
;
905 struct dm_thin_new_mapping
*m
, *tmp
;
907 INIT_LIST_HEAD(&maps
);
908 spin_lock_irqsave(&pool
->lock
, flags
);
909 list_splice_init(head
, &maps
);
910 spin_unlock_irqrestore(&pool
->lock
, flags
);
912 list_for_each_entry_safe(m
, tmp
, &maps
, list
)
919 static int io_overlaps_block(struct pool
*pool
, struct bio
*bio
)
921 return bio
->bi_iter
.bi_size
==
922 (pool
->sectors_per_block
<< SECTOR_SHIFT
);
925 static int io_overwrites_block(struct pool
*pool
, struct bio
*bio
)
927 return (bio_data_dir(bio
) == WRITE
) &&
928 io_overlaps_block(pool
, bio
);
931 static void save_and_set_endio(struct bio
*bio
, bio_end_io_t
**save
,
934 *save
= bio
->bi_end_io
;
938 static int ensure_next_mapping(struct pool
*pool
)
940 if (pool
->next_mapping
)
943 pool
->next_mapping
= mempool_alloc(pool
->mapping_pool
, GFP_ATOMIC
);
945 return pool
->next_mapping
? 0 : -ENOMEM
;
948 static struct dm_thin_new_mapping
*get_next_mapping(struct pool
*pool
)
950 struct dm_thin_new_mapping
*m
= pool
->next_mapping
;
952 BUG_ON(!pool
->next_mapping
);
954 memset(m
, 0, sizeof(struct dm_thin_new_mapping
));
955 INIT_LIST_HEAD(&m
->list
);
958 pool
->next_mapping
= NULL
;
963 static void ll_zero(struct thin_c
*tc
, struct dm_thin_new_mapping
*m
,
964 sector_t begin
, sector_t end
)
967 struct dm_io_region to
;
969 to
.bdev
= tc
->pool_dev
->bdev
;
971 to
.count
= end
- begin
;
973 r
= dm_kcopyd_zero(tc
->pool
->copier
, 1, &to
, 0, copy_complete
, m
);
975 DMERR_LIMIT("dm_kcopyd_zero() failed");
976 copy_complete(1, 1, m
);
980 static void remap_and_issue_overwrite(struct thin_c
*tc
, struct bio
*bio
,
981 dm_block_t data_block
,
982 struct dm_thin_new_mapping
*m
)
984 struct pool
*pool
= tc
->pool
;
985 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
987 h
->overwrite_mapping
= m
;
989 save_and_set_endio(bio
, &m
->saved_bi_end_io
, overwrite_endio
);
990 inc_all_io_entry(pool
, bio
);
991 remap_and_issue(tc
, bio
, data_block
);
995 * A partial copy also needs to zero the uncopied region.
997 static void schedule_copy(struct thin_c
*tc
, dm_block_t virt_block
,
998 struct dm_dev
*origin
, dm_block_t data_origin
,
999 dm_block_t data_dest
,
1000 struct dm_bio_prison_cell
*cell
, struct bio
*bio
,
1004 struct pool
*pool
= tc
->pool
;
1005 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1008 m
->virt_block
= virt_block
;
1009 m
->data_block
= data_dest
;
1013 * quiesce action + copy action + an extra reference held for the
1014 * duration of this function (we may need to inc later for a
1017 atomic_set(&m
->prepare_actions
, 3);
1019 if (!dm_deferred_set_add_work(pool
->shared_read_ds
, &m
->list
))
1020 complete_mapping_preparation(m
); /* already quiesced */
1023 * IO to pool_dev remaps to the pool target's data_dev.
1025 * If the whole block of data is being overwritten, we can issue the
1026 * bio immediately. Otherwise we use kcopyd to clone the data first.
1028 if (io_overwrites_block(pool
, bio
))
1029 remap_and_issue_overwrite(tc
, bio
, data_dest
, m
);
1031 struct dm_io_region from
, to
;
1033 from
.bdev
= origin
->bdev
;
1034 from
.sector
= data_origin
* pool
->sectors_per_block
;
1037 to
.bdev
= tc
->pool_dev
->bdev
;
1038 to
.sector
= data_dest
* pool
->sectors_per_block
;
1041 r
= dm_kcopyd_copy(pool
->copier
, &from
, 1, &to
,
1042 0, copy_complete
, m
);
1044 DMERR_LIMIT("dm_kcopyd_copy() failed");
1045 copy_complete(1, 1, m
);
1048 * We allow the zero to be issued, to simplify the
1049 * error path. Otherwise we'd need to start
1050 * worrying about decrementing the prepare_actions
1056 * Do we need to zero a tail region?
1058 if (len
< pool
->sectors_per_block
&& pool
->pf
.zero_new_blocks
) {
1059 atomic_inc(&m
->prepare_actions
);
1061 data_dest
* pool
->sectors_per_block
+ len
,
1062 (data_dest
+ 1) * pool
->sectors_per_block
);
1066 complete_mapping_preparation(m
); /* drop our ref */
1069 static void schedule_internal_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1070 dm_block_t data_origin
, dm_block_t data_dest
,
1071 struct dm_bio_prison_cell
*cell
, struct bio
*bio
)
1073 schedule_copy(tc
, virt_block
, tc
->pool_dev
,
1074 data_origin
, data_dest
, cell
, bio
,
1075 tc
->pool
->sectors_per_block
);
1078 static void schedule_zero(struct thin_c
*tc
, dm_block_t virt_block
,
1079 dm_block_t data_block
, struct dm_bio_prison_cell
*cell
,
1082 struct pool
*pool
= tc
->pool
;
1083 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1085 atomic_set(&m
->prepare_actions
, 1); /* no need to quiesce */
1087 m
->virt_block
= virt_block
;
1088 m
->data_block
= data_block
;
1092 * If the whole block of data is being overwritten or we are not
1093 * zeroing pre-existing data, we can issue the bio immediately.
1094 * Otherwise we use kcopyd to zero the data first.
1096 if (!pool
->pf
.zero_new_blocks
)
1097 process_prepared_mapping(m
);
1099 else if (io_overwrites_block(pool
, bio
))
1100 remap_and_issue_overwrite(tc
, bio
, data_block
, m
);
1104 data_block
* pool
->sectors_per_block
,
1105 (data_block
+ 1) * pool
->sectors_per_block
);
1108 static void schedule_external_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1109 dm_block_t data_dest
,
1110 struct dm_bio_prison_cell
*cell
, struct bio
*bio
)
1112 struct pool
*pool
= tc
->pool
;
1113 sector_t virt_block_begin
= virt_block
* pool
->sectors_per_block
;
1114 sector_t virt_block_end
= (virt_block
+ 1) * pool
->sectors_per_block
;
1116 if (virt_block_end
<= tc
->origin_size
)
1117 schedule_copy(tc
, virt_block
, tc
->origin_dev
,
1118 virt_block
, data_dest
, cell
, bio
,
1119 pool
->sectors_per_block
);
1121 else if (virt_block_begin
< tc
->origin_size
)
1122 schedule_copy(tc
, virt_block
, tc
->origin_dev
,
1123 virt_block
, data_dest
, cell
, bio
,
1124 tc
->origin_size
- virt_block_begin
);
1127 schedule_zero(tc
, virt_block
, data_dest
, cell
, bio
);
1131 * A non-zero return indicates read_only or fail_io mode.
1132 * Many callers don't care about the return value.
1134 static int commit(struct pool
*pool
)
1138 if (get_pool_mode(pool
) >= PM_READ_ONLY
)
1141 r
= dm_pool_commit_metadata(pool
->pmd
);
1143 metadata_operation_failed(pool
, "dm_pool_commit_metadata", r
);
1148 static void check_low_water_mark(struct pool
*pool
, dm_block_t free_blocks
)
1150 unsigned long flags
;
1152 if (free_blocks
<= pool
->low_water_blocks
&& !pool
->low_water_triggered
) {
1153 DMWARN("%s: reached low water mark for data device: sending event.",
1154 dm_device_name(pool
->pool_md
));
1155 spin_lock_irqsave(&pool
->lock
, flags
);
1156 pool
->low_water_triggered
= true;
1157 spin_unlock_irqrestore(&pool
->lock
, flags
);
1158 dm_table_event(pool
->ti
->table
);
1162 static void set_pool_mode(struct pool
*pool
, enum pool_mode new_mode
);
1164 static int alloc_data_block(struct thin_c
*tc
, dm_block_t
*result
)
1167 dm_block_t free_blocks
;
1168 struct pool
*pool
= tc
->pool
;
1170 if (WARN_ON(get_pool_mode(pool
) != PM_WRITE
))
1173 r
= dm_pool_get_free_block_count(pool
->pmd
, &free_blocks
);
1175 metadata_operation_failed(pool
, "dm_pool_get_free_block_count", r
);
1179 check_low_water_mark(pool
, free_blocks
);
1183 * Try to commit to see if that will free up some
1190 r
= dm_pool_get_free_block_count(pool
->pmd
, &free_blocks
);
1192 metadata_operation_failed(pool
, "dm_pool_get_free_block_count", r
);
1197 set_pool_mode(pool
, PM_OUT_OF_DATA_SPACE
);
1202 r
= dm_pool_alloc_data_block(pool
->pmd
, result
);
1204 metadata_operation_failed(pool
, "dm_pool_alloc_data_block", r
);
1212 * If we have run out of space, queue bios until the device is
1213 * resumed, presumably after having been reloaded with more space.
1215 static void retry_on_resume(struct bio
*bio
)
1217 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1218 struct thin_c
*tc
= h
->tc
;
1219 unsigned long flags
;
1221 spin_lock_irqsave(&tc
->lock
, flags
);
1222 bio_list_add(&tc
->retry_on_resume_list
, bio
);
1223 spin_unlock_irqrestore(&tc
->lock
, flags
);
1226 static int should_error_unserviceable_bio(struct pool
*pool
)
1228 enum pool_mode m
= get_pool_mode(pool
);
1232 /* Shouldn't get here */
1233 DMERR_LIMIT("bio unserviceable, yet pool is in PM_WRITE mode");
1236 case PM_OUT_OF_DATA_SPACE
:
1237 return pool
->pf
.error_if_no_space
? -ENOSPC
: 0;
1243 /* Shouldn't get here */
1244 DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode");
1249 static void handle_unserviceable_bio(struct pool
*pool
, struct bio
*bio
)
1251 int error
= should_error_unserviceable_bio(pool
);
1254 bio_endio(bio
, error
);
1256 retry_on_resume(bio
);
1259 static void retry_bios_on_resume(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
1262 struct bio_list bios
;
1265 error
= should_error_unserviceable_bio(pool
);
1267 cell_error_with_code(pool
, cell
, error
);
1271 bio_list_init(&bios
);
1272 cell_release(pool
, cell
, &bios
);
1274 while ((bio
= bio_list_pop(&bios
)))
1275 retry_on_resume(bio
);
1278 static void process_discard_cell(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1281 struct bio
*bio
= cell
->holder
;
1282 struct pool
*pool
= tc
->pool
;
1283 struct dm_bio_prison_cell
*cell2
;
1284 struct dm_cell_key key2
;
1285 dm_block_t block
= get_bio_block(tc
, bio
);
1286 struct dm_thin_lookup_result lookup_result
;
1287 struct dm_thin_new_mapping
*m
;
1289 if (tc
->requeue_mode
) {
1290 cell_requeue(pool
, cell
);
1294 r
= dm_thin_find_block(tc
->td
, block
, 1, &lookup_result
);
1298 * Check nobody is fiddling with this pool block. This can
1299 * happen if someone's in the process of breaking sharing
1302 build_data_key(tc
->td
, lookup_result
.block
, &key2
);
1303 if (bio_detain(tc
->pool
, &key2
, bio
, &cell2
)) {
1304 cell_defer_no_holder(tc
, cell
);
1308 if (io_overlaps_block(pool
, bio
)) {
1310 * IO may still be going to the destination block. We must
1311 * quiesce before we can do the removal.
1313 m
= get_next_mapping(pool
);
1315 m
->pass_discard
= pool
->pf
.discard_passdown
;
1316 m
->definitely_not_shared
= !lookup_result
.shared
;
1317 m
->virt_block
= block
;
1318 m
->data_block
= lookup_result
.block
;
1323 if (!dm_deferred_set_add_work(pool
->all_io_ds
, &m
->list
))
1324 pool
->process_prepared_discard(m
);
1327 inc_all_io_entry(pool
, bio
);
1328 cell_defer_no_holder(tc
, cell
);
1329 cell_defer_no_holder(tc
, cell2
);
1332 * The DM core makes sure that the discard doesn't span
1333 * a block boundary. So we submit the discard of a
1334 * partial block appropriately.
1336 if ((!lookup_result
.shared
) && pool
->pf
.discard_passdown
)
1337 remap_and_issue(tc
, bio
, lookup_result
.block
);
1345 * It isn't provisioned, just forget it.
1347 cell_defer_no_holder(tc
, cell
);
1352 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1354 cell_defer_no_holder(tc
, cell
);
1360 static void process_discard_bio(struct thin_c
*tc
, struct bio
*bio
)
1362 struct dm_bio_prison_cell
*cell
;
1363 struct dm_cell_key key
;
1364 dm_block_t block
= get_bio_block(tc
, bio
);
1366 build_virtual_key(tc
->td
, block
, &key
);
1367 if (bio_detain(tc
->pool
, &key
, bio
, &cell
))
1370 process_discard_cell(tc
, cell
);
1373 static void break_sharing(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
,
1374 struct dm_cell_key
*key
,
1375 struct dm_thin_lookup_result
*lookup_result
,
1376 struct dm_bio_prison_cell
*cell
)
1379 dm_block_t data_block
;
1380 struct pool
*pool
= tc
->pool
;
1382 r
= alloc_data_block(tc
, &data_block
);
1385 schedule_internal_copy(tc
, block
, lookup_result
->block
,
1386 data_block
, cell
, bio
);
1390 retry_bios_on_resume(pool
, cell
);
1394 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1396 cell_error(pool
, cell
);
1401 static void __remap_and_issue_shared_cell(void *context
,
1402 struct dm_bio_prison_cell
*cell
)
1404 struct remap_info
*info
= context
;
1407 while ((bio
= bio_list_pop(&cell
->bios
))) {
1408 if ((bio_data_dir(bio
) == WRITE
) ||
1409 (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
)))
1410 bio_list_add(&info
->defer_bios
, bio
);
1412 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));;
1414 h
->shared_read_entry
= dm_deferred_entry_inc(info
->tc
->pool
->shared_read_ds
);
1415 inc_all_io_entry(info
->tc
->pool
, bio
);
1416 bio_list_add(&info
->issue_bios
, bio
);
1421 static void remap_and_issue_shared_cell(struct thin_c
*tc
,
1422 struct dm_bio_prison_cell
*cell
,
1426 struct remap_info info
;
1429 bio_list_init(&info
.defer_bios
);
1430 bio_list_init(&info
.issue_bios
);
1432 cell_visit_release(tc
->pool
, __remap_and_issue_shared_cell
,
1435 while ((bio
= bio_list_pop(&info
.defer_bios
)))
1436 thin_defer_bio(tc
, bio
);
1438 while ((bio
= bio_list_pop(&info
.issue_bios
)))
1439 remap_and_issue(tc
, bio
, block
);
1442 static void process_shared_bio(struct thin_c
*tc
, struct bio
*bio
,
1444 struct dm_thin_lookup_result
*lookup_result
,
1445 struct dm_bio_prison_cell
*virt_cell
)
1447 struct dm_bio_prison_cell
*data_cell
;
1448 struct pool
*pool
= tc
->pool
;
1449 struct dm_cell_key key
;
1452 * If cell is already occupied, then sharing is already in the process
1453 * of being broken so we have nothing further to do here.
1455 build_data_key(tc
->td
, lookup_result
->block
, &key
);
1456 if (bio_detain(pool
, &key
, bio
, &data_cell
)) {
1457 cell_defer_no_holder(tc
, virt_cell
);
1461 if (bio_data_dir(bio
) == WRITE
&& bio
->bi_iter
.bi_size
) {
1462 break_sharing(tc
, bio
, block
, &key
, lookup_result
, data_cell
);
1463 cell_defer_no_holder(tc
, virt_cell
);
1465 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1467 h
->shared_read_entry
= dm_deferred_entry_inc(pool
->shared_read_ds
);
1468 inc_all_io_entry(pool
, bio
);
1469 remap_and_issue(tc
, bio
, lookup_result
->block
);
1471 remap_and_issue_shared_cell(tc
, data_cell
, lookup_result
->block
);
1472 remap_and_issue_shared_cell(tc
, virt_cell
, lookup_result
->block
);
1476 static void provision_block(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
,
1477 struct dm_bio_prison_cell
*cell
)
1480 dm_block_t data_block
;
1481 struct pool
*pool
= tc
->pool
;
1484 * Remap empty bios (flushes) immediately, without provisioning.
1486 if (!bio
->bi_iter
.bi_size
) {
1487 inc_all_io_entry(pool
, bio
);
1488 cell_defer_no_holder(tc
, cell
);
1490 remap_and_issue(tc
, bio
, 0);
1495 * Fill read bios with zeroes and complete them immediately.
1497 if (bio_data_dir(bio
) == READ
) {
1499 cell_defer_no_holder(tc
, cell
);
1504 r
= alloc_data_block(tc
, &data_block
);
1508 schedule_external_copy(tc
, block
, data_block
, cell
, bio
);
1510 schedule_zero(tc
, block
, data_block
, cell
, bio
);
1514 retry_bios_on_resume(pool
, cell
);
1518 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1520 cell_error(pool
, cell
);
1525 static void process_cell(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1528 struct pool
*pool
= tc
->pool
;
1529 struct bio
*bio
= cell
->holder
;
1530 dm_block_t block
= get_bio_block(tc
, bio
);
1531 struct dm_thin_lookup_result lookup_result
;
1533 if (tc
->requeue_mode
) {
1534 cell_requeue(pool
, cell
);
1538 r
= dm_thin_find_block(tc
->td
, block
, 1, &lookup_result
);
1541 if (lookup_result
.shared
)
1542 process_shared_bio(tc
, bio
, block
, &lookup_result
, cell
);
1544 inc_all_io_entry(pool
, bio
);
1545 remap_and_issue(tc
, bio
, lookup_result
.block
);
1546 inc_remap_and_issue_cell(tc
, cell
, lookup_result
.block
);
1551 if (bio_data_dir(bio
) == READ
&& tc
->origin_dev
) {
1552 inc_all_io_entry(pool
, bio
);
1553 cell_defer_no_holder(tc
, cell
);
1555 if (bio_end_sector(bio
) <= tc
->origin_size
)
1556 remap_to_origin_and_issue(tc
, bio
);
1558 else if (bio
->bi_iter
.bi_sector
< tc
->origin_size
) {
1560 bio
->bi_iter
.bi_size
= (tc
->origin_size
- bio
->bi_iter
.bi_sector
) << SECTOR_SHIFT
;
1561 remap_to_origin_and_issue(tc
, bio
);
1568 provision_block(tc
, bio
, block
, cell
);
1572 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1574 cell_defer_no_holder(tc
, cell
);
1580 static void process_bio(struct thin_c
*tc
, struct bio
*bio
)
1582 struct pool
*pool
= tc
->pool
;
1583 dm_block_t block
= get_bio_block(tc
, bio
);
1584 struct dm_bio_prison_cell
*cell
;
1585 struct dm_cell_key key
;
1588 * If cell is already occupied, then the block is already
1589 * being provisioned so we have nothing further to do here.
1591 build_virtual_key(tc
->td
, block
, &key
);
1592 if (bio_detain(pool
, &key
, bio
, &cell
))
1595 process_cell(tc
, cell
);
1598 static void __process_bio_read_only(struct thin_c
*tc
, struct bio
*bio
,
1599 struct dm_bio_prison_cell
*cell
)
1602 int rw
= bio_data_dir(bio
);
1603 dm_block_t block
= get_bio_block(tc
, bio
);
1604 struct dm_thin_lookup_result lookup_result
;
1606 r
= dm_thin_find_block(tc
->td
, block
, 1, &lookup_result
);
1609 if (lookup_result
.shared
&& (rw
== WRITE
) && bio
->bi_iter
.bi_size
) {
1610 handle_unserviceable_bio(tc
->pool
, bio
);
1612 cell_defer_no_holder(tc
, cell
);
1614 inc_all_io_entry(tc
->pool
, bio
);
1615 remap_and_issue(tc
, bio
, lookup_result
.block
);
1617 inc_remap_and_issue_cell(tc
, cell
, lookup_result
.block
);
1623 cell_defer_no_holder(tc
, cell
);
1625 handle_unserviceable_bio(tc
->pool
, bio
);
1629 if (tc
->origin_dev
) {
1630 inc_all_io_entry(tc
->pool
, bio
);
1631 remap_to_origin_and_issue(tc
, bio
);
1640 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1643 cell_defer_no_holder(tc
, cell
);
1649 static void process_bio_read_only(struct thin_c
*tc
, struct bio
*bio
)
1651 __process_bio_read_only(tc
, bio
, NULL
);
1654 static void process_cell_read_only(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1656 __process_bio_read_only(tc
, cell
->holder
, cell
);
1659 static void process_bio_success(struct thin_c
*tc
, struct bio
*bio
)
1664 static void process_bio_fail(struct thin_c
*tc
, struct bio
*bio
)
1669 static void process_cell_success(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1671 cell_success(tc
->pool
, cell
);
1674 static void process_cell_fail(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1676 cell_error(tc
->pool
, cell
);
1680 * FIXME: should we also commit due to size of transaction, measured in
1683 static int need_commit_due_to_time(struct pool
*pool
)
1685 return jiffies
< pool
->last_commit_jiffies
||
1686 jiffies
> pool
->last_commit_jiffies
+ COMMIT_PERIOD
;
1689 #define thin_pbd(node) rb_entry((node), struct dm_thin_endio_hook, rb_node)
1690 #define thin_bio(pbd) dm_bio_from_per_bio_data((pbd), sizeof(struct dm_thin_endio_hook))
1692 static void __thin_bio_rb_add(struct thin_c
*tc
, struct bio
*bio
)
1694 struct rb_node
**rbp
, *parent
;
1695 struct dm_thin_endio_hook
*pbd
;
1696 sector_t bi_sector
= bio
->bi_iter
.bi_sector
;
1698 rbp
= &tc
->sort_bio_list
.rb_node
;
1702 pbd
= thin_pbd(parent
);
1704 if (bi_sector
< thin_bio(pbd
)->bi_iter
.bi_sector
)
1705 rbp
= &(*rbp
)->rb_left
;
1707 rbp
= &(*rbp
)->rb_right
;
1710 pbd
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1711 rb_link_node(&pbd
->rb_node
, parent
, rbp
);
1712 rb_insert_color(&pbd
->rb_node
, &tc
->sort_bio_list
);
1715 static void __extract_sorted_bios(struct thin_c
*tc
)
1717 struct rb_node
*node
;
1718 struct dm_thin_endio_hook
*pbd
;
1721 for (node
= rb_first(&tc
->sort_bio_list
); node
; node
= rb_next(node
)) {
1722 pbd
= thin_pbd(node
);
1723 bio
= thin_bio(pbd
);
1725 bio_list_add(&tc
->deferred_bio_list
, bio
);
1726 rb_erase(&pbd
->rb_node
, &tc
->sort_bio_list
);
1729 WARN_ON(!RB_EMPTY_ROOT(&tc
->sort_bio_list
));
1732 static void __sort_thin_deferred_bios(struct thin_c
*tc
)
1735 struct bio_list bios
;
1737 bio_list_init(&bios
);
1738 bio_list_merge(&bios
, &tc
->deferred_bio_list
);
1739 bio_list_init(&tc
->deferred_bio_list
);
1741 /* Sort deferred_bio_list using rb-tree */
1742 while ((bio
= bio_list_pop(&bios
)))
1743 __thin_bio_rb_add(tc
, bio
);
1746 * Transfer the sorted bios in sort_bio_list back to
1747 * deferred_bio_list to allow lockless submission of
1750 __extract_sorted_bios(tc
);
1753 static void process_thin_deferred_bios(struct thin_c
*tc
)
1755 struct pool
*pool
= tc
->pool
;
1756 unsigned long flags
;
1758 struct bio_list bios
;
1759 struct blk_plug plug
;
1762 if (tc
->requeue_mode
) {
1763 error_thin_bio_list(tc
, &tc
->deferred_bio_list
, DM_ENDIO_REQUEUE
);
1767 bio_list_init(&bios
);
1769 spin_lock_irqsave(&tc
->lock
, flags
);
1771 if (bio_list_empty(&tc
->deferred_bio_list
)) {
1772 spin_unlock_irqrestore(&tc
->lock
, flags
);
1776 __sort_thin_deferred_bios(tc
);
1778 bio_list_merge(&bios
, &tc
->deferred_bio_list
);
1779 bio_list_init(&tc
->deferred_bio_list
);
1781 spin_unlock_irqrestore(&tc
->lock
, flags
);
1783 blk_start_plug(&plug
);
1784 while ((bio
= bio_list_pop(&bios
))) {
1786 * If we've got no free new_mapping structs, and processing
1787 * this bio might require one, we pause until there are some
1788 * prepared mappings to process.
1790 if (ensure_next_mapping(pool
)) {
1791 spin_lock_irqsave(&tc
->lock
, flags
);
1792 bio_list_add(&tc
->deferred_bio_list
, bio
);
1793 bio_list_merge(&tc
->deferred_bio_list
, &bios
);
1794 spin_unlock_irqrestore(&tc
->lock
, flags
);
1798 if (bio
->bi_rw
& REQ_DISCARD
)
1799 pool
->process_discard(tc
, bio
);
1801 pool
->process_bio(tc
, bio
);
1803 if ((count
++ & 127) == 0) {
1804 throttle_work_update(&pool
->throttle
);
1805 dm_pool_issue_prefetches(pool
->pmd
);
1808 blk_finish_plug(&plug
);
1811 static int cmp_cells(const void *lhs
, const void *rhs
)
1813 struct dm_bio_prison_cell
*lhs_cell
= *((struct dm_bio_prison_cell
**) lhs
);
1814 struct dm_bio_prison_cell
*rhs_cell
= *((struct dm_bio_prison_cell
**) rhs
);
1816 BUG_ON(!lhs_cell
->holder
);
1817 BUG_ON(!rhs_cell
->holder
);
1819 if (lhs_cell
->holder
->bi_iter
.bi_sector
< rhs_cell
->holder
->bi_iter
.bi_sector
)
1822 if (lhs_cell
->holder
->bi_iter
.bi_sector
> rhs_cell
->holder
->bi_iter
.bi_sector
)
1828 static unsigned sort_cells(struct pool
*pool
, struct list_head
*cells
)
1831 struct dm_bio_prison_cell
*cell
, *tmp
;
1833 list_for_each_entry_safe(cell
, tmp
, cells
, user_list
) {
1834 if (count
>= CELL_SORT_ARRAY_SIZE
)
1837 pool
->cell_sort_array
[count
++] = cell
;
1838 list_del(&cell
->user_list
);
1841 sort(pool
->cell_sort_array
, count
, sizeof(cell
), cmp_cells
, NULL
);
1846 static void process_thin_deferred_cells(struct thin_c
*tc
)
1848 struct pool
*pool
= tc
->pool
;
1849 unsigned long flags
;
1850 struct list_head cells
;
1851 struct dm_bio_prison_cell
*cell
;
1852 unsigned i
, j
, count
;
1854 INIT_LIST_HEAD(&cells
);
1856 spin_lock_irqsave(&tc
->lock
, flags
);
1857 list_splice_init(&tc
->deferred_cells
, &cells
);
1858 spin_unlock_irqrestore(&tc
->lock
, flags
);
1860 if (list_empty(&cells
))
1864 count
= sort_cells(tc
->pool
, &cells
);
1866 for (i
= 0; i
< count
; i
++) {
1867 cell
= pool
->cell_sort_array
[i
];
1868 BUG_ON(!cell
->holder
);
1871 * If we've got no free new_mapping structs, and processing
1872 * this bio might require one, we pause until there are some
1873 * prepared mappings to process.
1875 if (ensure_next_mapping(pool
)) {
1876 for (j
= i
; j
< count
; j
++)
1877 list_add(&pool
->cell_sort_array
[j
]->user_list
, &cells
);
1879 spin_lock_irqsave(&tc
->lock
, flags
);
1880 list_splice(&cells
, &tc
->deferred_cells
);
1881 spin_unlock_irqrestore(&tc
->lock
, flags
);
1885 if (cell
->holder
->bi_rw
& REQ_DISCARD
)
1886 pool
->process_discard_cell(tc
, cell
);
1888 pool
->process_cell(tc
, cell
);
1890 } while (!list_empty(&cells
));
1893 static void thin_get(struct thin_c
*tc
);
1894 static void thin_put(struct thin_c
*tc
);
1897 * We can't hold rcu_read_lock() around code that can block. So we
1898 * find a thin with the rcu lock held; bump a refcount; then drop
1901 static struct thin_c
*get_first_thin(struct pool
*pool
)
1903 struct thin_c
*tc
= NULL
;
1906 if (!list_empty(&pool
->active_thins
)) {
1907 tc
= list_entry_rcu(pool
->active_thins
.next
, struct thin_c
, list
);
1915 static struct thin_c
*get_next_thin(struct pool
*pool
, struct thin_c
*tc
)
1917 struct thin_c
*old_tc
= tc
;
1920 list_for_each_entry_continue_rcu(tc
, &pool
->active_thins
, list
) {
1932 static void process_deferred_bios(struct pool
*pool
)
1934 unsigned long flags
;
1936 struct bio_list bios
;
1939 tc
= get_first_thin(pool
);
1941 process_thin_deferred_cells(tc
);
1942 process_thin_deferred_bios(tc
);
1943 tc
= get_next_thin(pool
, tc
);
1947 * If there are any deferred flush bios, we must commit
1948 * the metadata before issuing them.
1950 bio_list_init(&bios
);
1951 spin_lock_irqsave(&pool
->lock
, flags
);
1952 bio_list_merge(&bios
, &pool
->deferred_flush_bios
);
1953 bio_list_init(&pool
->deferred_flush_bios
);
1954 spin_unlock_irqrestore(&pool
->lock
, flags
);
1956 if (bio_list_empty(&bios
) &&
1957 !(dm_pool_changed_this_transaction(pool
->pmd
) && need_commit_due_to_time(pool
)))
1961 while ((bio
= bio_list_pop(&bios
)))
1965 pool
->last_commit_jiffies
= jiffies
;
1967 while ((bio
= bio_list_pop(&bios
)))
1968 generic_make_request(bio
);
1971 static void do_worker(struct work_struct
*ws
)
1973 struct pool
*pool
= container_of(ws
, struct pool
, worker
);
1975 throttle_work_start(&pool
->throttle
);
1976 dm_pool_issue_prefetches(pool
->pmd
);
1977 throttle_work_update(&pool
->throttle
);
1978 process_prepared(pool
, &pool
->prepared_mappings
, &pool
->process_prepared_mapping
);
1979 throttle_work_update(&pool
->throttle
);
1980 process_prepared(pool
, &pool
->prepared_discards
, &pool
->process_prepared_discard
);
1981 throttle_work_update(&pool
->throttle
);
1982 process_deferred_bios(pool
);
1983 throttle_work_complete(&pool
->throttle
);
1987 * We want to commit periodically so that not too much
1988 * unwritten data builds up.
1990 static void do_waker(struct work_struct
*ws
)
1992 struct pool
*pool
= container_of(to_delayed_work(ws
), struct pool
, waker
);
1994 queue_delayed_work(pool
->wq
, &pool
->waker
, COMMIT_PERIOD
);
1998 * We're holding onto IO to allow userland time to react. After the
1999 * timeout either the pool will have been resized (and thus back in
2000 * PM_WRITE mode), or we degrade to PM_READ_ONLY and start erroring IO.
2002 static void do_no_space_timeout(struct work_struct
*ws
)
2004 struct pool
*pool
= container_of(to_delayed_work(ws
), struct pool
,
2007 if (get_pool_mode(pool
) == PM_OUT_OF_DATA_SPACE
&& !pool
->pf
.error_if_no_space
)
2008 set_pool_mode(pool
, PM_READ_ONLY
);
2011 /*----------------------------------------------------------------*/
2014 struct work_struct worker
;
2015 struct completion complete
;
2018 static struct pool_work
*to_pool_work(struct work_struct
*ws
)
2020 return container_of(ws
, struct pool_work
, worker
);
2023 static void pool_work_complete(struct pool_work
*pw
)
2025 complete(&pw
->complete
);
2028 static void pool_work_wait(struct pool_work
*pw
, struct pool
*pool
,
2029 void (*fn
)(struct work_struct
*))
2031 INIT_WORK_ONSTACK(&pw
->worker
, fn
);
2032 init_completion(&pw
->complete
);
2033 queue_work(pool
->wq
, &pw
->worker
);
2034 wait_for_completion(&pw
->complete
);
2037 /*----------------------------------------------------------------*/
2039 struct noflush_work
{
2040 struct pool_work pw
;
2044 static struct noflush_work
*to_noflush(struct work_struct
*ws
)
2046 return container_of(to_pool_work(ws
), struct noflush_work
, pw
);
2049 static void do_noflush_start(struct work_struct
*ws
)
2051 struct noflush_work
*w
= to_noflush(ws
);
2052 w
->tc
->requeue_mode
= true;
2054 pool_work_complete(&w
->pw
);
2057 static void do_noflush_stop(struct work_struct
*ws
)
2059 struct noflush_work
*w
= to_noflush(ws
);
2060 w
->tc
->requeue_mode
= false;
2061 pool_work_complete(&w
->pw
);
2064 static void noflush_work(struct thin_c
*tc
, void (*fn
)(struct work_struct
*))
2066 struct noflush_work w
;
2069 pool_work_wait(&w
.pw
, tc
->pool
, fn
);
2072 /*----------------------------------------------------------------*/
2074 static enum pool_mode
get_pool_mode(struct pool
*pool
)
2076 return pool
->pf
.mode
;
2079 static void notify_of_pool_mode_change(struct pool
*pool
, const char *new_mode
)
2081 dm_table_event(pool
->ti
->table
);
2082 DMINFO("%s: switching pool to %s mode",
2083 dm_device_name(pool
->pool_md
), new_mode
);
2086 static void set_pool_mode(struct pool
*pool
, enum pool_mode new_mode
)
2088 struct pool_c
*pt
= pool
->ti
->private;
2089 bool needs_check
= dm_pool_metadata_needs_check(pool
->pmd
);
2090 enum pool_mode old_mode
= get_pool_mode(pool
);
2091 unsigned long no_space_timeout
= ACCESS_ONCE(no_space_timeout_secs
) * HZ
;
2094 * Never allow the pool to transition to PM_WRITE mode if user
2095 * intervention is required to verify metadata and data consistency.
2097 if (new_mode
== PM_WRITE
&& needs_check
) {
2098 DMERR("%s: unable to switch pool to write mode until repaired.",
2099 dm_device_name(pool
->pool_md
));
2100 if (old_mode
!= new_mode
)
2101 new_mode
= old_mode
;
2103 new_mode
= PM_READ_ONLY
;
2106 * If we were in PM_FAIL mode, rollback of metadata failed. We're
2107 * not going to recover without a thin_repair. So we never let the
2108 * pool move out of the old mode.
2110 if (old_mode
== PM_FAIL
)
2111 new_mode
= old_mode
;
2115 if (old_mode
!= new_mode
)
2116 notify_of_pool_mode_change(pool
, "failure");
2117 dm_pool_metadata_read_only(pool
->pmd
);
2118 pool
->process_bio
= process_bio_fail
;
2119 pool
->process_discard
= process_bio_fail
;
2120 pool
->process_cell
= process_cell_fail
;
2121 pool
->process_discard_cell
= process_cell_fail
;
2122 pool
->process_prepared_mapping
= process_prepared_mapping_fail
;
2123 pool
->process_prepared_discard
= process_prepared_discard_fail
;
2125 error_retry_list(pool
);
2129 if (old_mode
!= new_mode
)
2130 notify_of_pool_mode_change(pool
, "read-only");
2131 dm_pool_metadata_read_only(pool
->pmd
);
2132 pool
->process_bio
= process_bio_read_only
;
2133 pool
->process_discard
= process_bio_success
;
2134 pool
->process_cell
= process_cell_read_only
;
2135 pool
->process_discard_cell
= process_cell_success
;
2136 pool
->process_prepared_mapping
= process_prepared_mapping_fail
;
2137 pool
->process_prepared_discard
= process_prepared_discard_passdown
;
2139 error_retry_list(pool
);
2142 case PM_OUT_OF_DATA_SPACE
:
2144 * Ideally we'd never hit this state; the low water mark
2145 * would trigger userland to extend the pool before we
2146 * completely run out of data space. However, many small
2147 * IOs to unprovisioned space can consume data space at an
2148 * alarming rate. Adjust your low water mark if you're
2149 * frequently seeing this mode.
2151 if (old_mode
!= new_mode
)
2152 notify_of_pool_mode_change(pool
, "out-of-data-space");
2153 pool
->process_bio
= process_bio_read_only
;
2154 pool
->process_discard
= process_discard_bio
;
2155 pool
->process_cell
= process_cell_read_only
;
2156 pool
->process_discard_cell
= process_discard_cell
;
2157 pool
->process_prepared_mapping
= process_prepared_mapping
;
2158 pool
->process_prepared_discard
= process_prepared_discard_passdown
;
2160 if (!pool
->pf
.error_if_no_space
&& no_space_timeout
)
2161 queue_delayed_work(pool
->wq
, &pool
->no_space_timeout
, no_space_timeout
);
2165 if (old_mode
!= new_mode
)
2166 notify_of_pool_mode_change(pool
, "write");
2167 dm_pool_metadata_read_write(pool
->pmd
);
2168 pool
->process_bio
= process_bio
;
2169 pool
->process_discard
= process_discard_bio
;
2170 pool
->process_cell
= process_cell
;
2171 pool
->process_discard_cell
= process_discard_cell
;
2172 pool
->process_prepared_mapping
= process_prepared_mapping
;
2173 pool
->process_prepared_discard
= process_prepared_discard
;
2177 pool
->pf
.mode
= new_mode
;
2179 * The pool mode may have changed, sync it so bind_control_target()
2180 * doesn't cause an unexpected mode transition on resume.
2182 pt
->adjusted_pf
.mode
= new_mode
;
2185 static void abort_transaction(struct pool
*pool
)
2187 const char *dev_name
= dm_device_name(pool
->pool_md
);
2189 DMERR_LIMIT("%s: aborting current metadata transaction", dev_name
);
2190 if (dm_pool_abort_metadata(pool
->pmd
)) {
2191 DMERR("%s: failed to abort metadata transaction", dev_name
);
2192 set_pool_mode(pool
, PM_FAIL
);
2195 if (dm_pool_metadata_set_needs_check(pool
->pmd
)) {
2196 DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name
);
2197 set_pool_mode(pool
, PM_FAIL
);
2201 static void metadata_operation_failed(struct pool
*pool
, const char *op
, int r
)
2203 DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d",
2204 dm_device_name(pool
->pool_md
), op
, r
);
2206 abort_transaction(pool
);
2207 set_pool_mode(pool
, PM_READ_ONLY
);
2210 /*----------------------------------------------------------------*/
2213 * Mapping functions.
2217 * Called only while mapping a thin bio to hand it over to the workqueue.
2219 static void thin_defer_bio(struct thin_c
*tc
, struct bio
*bio
)
2221 unsigned long flags
;
2222 struct pool
*pool
= tc
->pool
;
2224 spin_lock_irqsave(&tc
->lock
, flags
);
2225 bio_list_add(&tc
->deferred_bio_list
, bio
);
2226 spin_unlock_irqrestore(&tc
->lock
, flags
);
2231 static void thin_defer_bio_with_throttle(struct thin_c
*tc
, struct bio
*bio
)
2233 struct pool
*pool
= tc
->pool
;
2235 throttle_lock(&pool
->throttle
);
2236 thin_defer_bio(tc
, bio
);
2237 throttle_unlock(&pool
->throttle
);
2240 static void thin_defer_cell(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
2242 unsigned long flags
;
2243 struct pool
*pool
= tc
->pool
;
2245 throttle_lock(&pool
->throttle
);
2246 spin_lock_irqsave(&tc
->lock
, flags
);
2247 list_add_tail(&cell
->user_list
, &tc
->deferred_cells
);
2248 spin_unlock_irqrestore(&tc
->lock
, flags
);
2249 throttle_unlock(&pool
->throttle
);
2254 static void thin_hook_bio(struct thin_c
*tc
, struct bio
*bio
)
2256 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
2259 h
->shared_read_entry
= NULL
;
2260 h
->all_io_entry
= NULL
;
2261 h
->overwrite_mapping
= NULL
;
2265 * Non-blocking function called from the thin target's map function.
2267 static int thin_bio_map(struct dm_target
*ti
, struct bio
*bio
)
2270 struct thin_c
*tc
= ti
->private;
2271 dm_block_t block
= get_bio_block(tc
, bio
);
2272 struct dm_thin_device
*td
= tc
->td
;
2273 struct dm_thin_lookup_result result
;
2274 struct dm_bio_prison_cell
*virt_cell
, *data_cell
;
2275 struct dm_cell_key key
;
2277 thin_hook_bio(tc
, bio
);
2279 if (tc
->requeue_mode
) {
2280 bio_endio(bio
, DM_ENDIO_REQUEUE
);
2281 return DM_MAPIO_SUBMITTED
;
2284 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
2286 return DM_MAPIO_SUBMITTED
;
2289 if (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
)) {
2290 thin_defer_bio_with_throttle(tc
, bio
);
2291 return DM_MAPIO_SUBMITTED
;
2295 * We must hold the virtual cell before doing the lookup, otherwise
2296 * there's a race with discard.
2298 build_virtual_key(tc
->td
, block
, &key
);
2299 if (bio_detain(tc
->pool
, &key
, bio
, &virt_cell
))
2300 return DM_MAPIO_SUBMITTED
;
2302 r
= dm_thin_find_block(td
, block
, 0, &result
);
2305 * Note that we defer readahead too.
2309 if (unlikely(result
.shared
)) {
2311 * We have a race condition here between the
2312 * result.shared value returned by the lookup and
2313 * snapshot creation, which may cause new
2316 * To avoid this always quiesce the origin before
2317 * taking the snap. You want to do this anyway to
2318 * ensure a consistent application view
2321 * More distant ancestors are irrelevant. The
2322 * shared flag will be set in their case.
2324 thin_defer_cell(tc
, virt_cell
);
2325 return DM_MAPIO_SUBMITTED
;
2328 build_data_key(tc
->td
, result
.block
, &key
);
2329 if (bio_detain(tc
->pool
, &key
, bio
, &data_cell
)) {
2330 cell_defer_no_holder(tc
, virt_cell
);
2331 return DM_MAPIO_SUBMITTED
;
2334 inc_all_io_entry(tc
->pool
, bio
);
2335 cell_defer_no_holder(tc
, data_cell
);
2336 cell_defer_no_holder(tc
, virt_cell
);
2338 remap(tc
, bio
, result
.block
);
2339 return DM_MAPIO_REMAPPED
;
2342 if (get_pool_mode(tc
->pool
) == PM_READ_ONLY
) {
2344 * This block isn't provisioned, and we have no way
2347 handle_unserviceable_bio(tc
->pool
, bio
);
2348 cell_defer_no_holder(tc
, virt_cell
);
2349 return DM_MAPIO_SUBMITTED
;
2354 thin_defer_cell(tc
, virt_cell
);
2355 return DM_MAPIO_SUBMITTED
;
2359 * Must always call bio_io_error on failure.
2360 * dm_thin_find_block can fail with -EINVAL if the
2361 * pool is switched to fail-io mode.
2364 cell_defer_no_holder(tc
, virt_cell
);
2365 return DM_MAPIO_SUBMITTED
;
2369 static int pool_is_congested(struct dm_target_callbacks
*cb
, int bdi_bits
)
2371 struct pool_c
*pt
= container_of(cb
, struct pool_c
, callbacks
);
2372 struct request_queue
*q
;
2374 if (get_pool_mode(pt
->pool
) == PM_OUT_OF_DATA_SPACE
)
2377 q
= bdev_get_queue(pt
->data_dev
->bdev
);
2378 return bdi_congested(&q
->backing_dev_info
, bdi_bits
);
2381 static void requeue_bios(struct pool
*pool
)
2383 unsigned long flags
;
2387 list_for_each_entry_rcu(tc
, &pool
->active_thins
, list
) {
2388 spin_lock_irqsave(&tc
->lock
, flags
);
2389 bio_list_merge(&tc
->deferred_bio_list
, &tc
->retry_on_resume_list
);
2390 bio_list_init(&tc
->retry_on_resume_list
);
2391 spin_unlock_irqrestore(&tc
->lock
, flags
);
2396 /*----------------------------------------------------------------
2397 * Binding of control targets to a pool object
2398 *--------------------------------------------------------------*/
2399 static bool data_dev_supports_discard(struct pool_c
*pt
)
2401 struct request_queue
*q
= bdev_get_queue(pt
->data_dev
->bdev
);
2403 return q
&& blk_queue_discard(q
);
2406 static bool is_factor(sector_t block_size
, uint32_t n
)
2408 return !sector_div(block_size
, n
);
2412 * If discard_passdown was enabled verify that the data device
2413 * supports discards. Disable discard_passdown if not.
2415 static void disable_passdown_if_not_supported(struct pool_c
*pt
)
2417 struct pool
*pool
= pt
->pool
;
2418 struct block_device
*data_bdev
= pt
->data_dev
->bdev
;
2419 struct queue_limits
*data_limits
= &bdev_get_queue(data_bdev
)->limits
;
2420 sector_t block_size
= pool
->sectors_per_block
<< SECTOR_SHIFT
;
2421 const char *reason
= NULL
;
2422 char buf
[BDEVNAME_SIZE
];
2424 if (!pt
->adjusted_pf
.discard_passdown
)
2427 if (!data_dev_supports_discard(pt
))
2428 reason
= "discard unsupported";
2430 else if (data_limits
->max_discard_sectors
< pool
->sectors_per_block
)
2431 reason
= "max discard sectors smaller than a block";
2433 else if (data_limits
->discard_granularity
> block_size
)
2434 reason
= "discard granularity larger than a block";
2436 else if (!is_factor(block_size
, data_limits
->discard_granularity
))
2437 reason
= "discard granularity not a factor of block size";
2440 DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev
, buf
), reason
);
2441 pt
->adjusted_pf
.discard_passdown
= false;
2445 static int bind_control_target(struct pool
*pool
, struct dm_target
*ti
)
2447 struct pool_c
*pt
= ti
->private;
2450 * We want to make sure that a pool in PM_FAIL mode is never upgraded.
2452 enum pool_mode old_mode
= get_pool_mode(pool
);
2453 enum pool_mode new_mode
= pt
->adjusted_pf
.mode
;
2456 * Don't change the pool's mode until set_pool_mode() below.
2457 * Otherwise the pool's process_* function pointers may
2458 * not match the desired pool mode.
2460 pt
->adjusted_pf
.mode
= old_mode
;
2463 pool
->pf
= pt
->adjusted_pf
;
2464 pool
->low_water_blocks
= pt
->low_water_blocks
;
2466 set_pool_mode(pool
, new_mode
);
2471 static void unbind_control_target(struct pool
*pool
, struct dm_target
*ti
)
2477 /*----------------------------------------------------------------
2479 *--------------------------------------------------------------*/
2480 /* Initialize pool features. */
2481 static void pool_features_init(struct pool_features
*pf
)
2483 pf
->mode
= PM_WRITE
;
2484 pf
->zero_new_blocks
= true;
2485 pf
->discard_enabled
= true;
2486 pf
->discard_passdown
= true;
2487 pf
->error_if_no_space
= false;
2490 static void __pool_destroy(struct pool
*pool
)
2492 __pool_table_remove(pool
);
2494 if (dm_pool_metadata_close(pool
->pmd
) < 0)
2495 DMWARN("%s: dm_pool_metadata_close() failed.", __func__
);
2497 dm_bio_prison_destroy(pool
->prison
);
2498 dm_kcopyd_client_destroy(pool
->copier
);
2501 destroy_workqueue(pool
->wq
);
2503 if (pool
->next_mapping
)
2504 mempool_free(pool
->next_mapping
, pool
->mapping_pool
);
2505 mempool_destroy(pool
->mapping_pool
);
2506 dm_deferred_set_destroy(pool
->shared_read_ds
);
2507 dm_deferred_set_destroy(pool
->all_io_ds
);
2511 static struct kmem_cache
*_new_mapping_cache
;
2513 static struct pool
*pool_create(struct mapped_device
*pool_md
,
2514 struct block_device
*metadata_dev
,
2515 unsigned long block_size
,
2516 int read_only
, char **error
)
2521 struct dm_pool_metadata
*pmd
;
2522 bool format_device
= read_only
? false : true;
2524 pmd
= dm_pool_metadata_open(metadata_dev
, block_size
, format_device
);
2526 *error
= "Error creating metadata object";
2527 return (struct pool
*)pmd
;
2530 pool
= kmalloc(sizeof(*pool
), GFP_KERNEL
);
2532 *error
= "Error allocating memory for pool";
2533 err_p
= ERR_PTR(-ENOMEM
);
2538 pool
->sectors_per_block
= block_size
;
2539 if (block_size
& (block_size
- 1))
2540 pool
->sectors_per_block_shift
= -1;
2542 pool
->sectors_per_block_shift
= __ffs(block_size
);
2543 pool
->low_water_blocks
= 0;
2544 pool_features_init(&pool
->pf
);
2545 pool
->prison
= dm_bio_prison_create();
2546 if (!pool
->prison
) {
2547 *error
= "Error creating pool's bio prison";
2548 err_p
= ERR_PTR(-ENOMEM
);
2552 pool
->copier
= dm_kcopyd_client_create(&dm_kcopyd_throttle
);
2553 if (IS_ERR(pool
->copier
)) {
2554 r
= PTR_ERR(pool
->copier
);
2555 *error
= "Error creating pool's kcopyd client";
2557 goto bad_kcopyd_client
;
2561 * Create singlethreaded workqueue that will service all devices
2562 * that use this metadata.
2564 pool
->wq
= alloc_ordered_workqueue("dm-" DM_MSG_PREFIX
, WQ_MEM_RECLAIM
);
2566 *error
= "Error creating pool's workqueue";
2567 err_p
= ERR_PTR(-ENOMEM
);
2571 throttle_init(&pool
->throttle
);
2572 INIT_WORK(&pool
->worker
, do_worker
);
2573 INIT_DELAYED_WORK(&pool
->waker
, do_waker
);
2574 INIT_DELAYED_WORK(&pool
->no_space_timeout
, do_no_space_timeout
);
2575 spin_lock_init(&pool
->lock
);
2576 bio_list_init(&pool
->deferred_flush_bios
);
2577 INIT_LIST_HEAD(&pool
->prepared_mappings
);
2578 INIT_LIST_HEAD(&pool
->prepared_discards
);
2579 INIT_LIST_HEAD(&pool
->active_thins
);
2580 pool
->low_water_triggered
= false;
2581 pool
->suspended
= true;
2583 pool
->shared_read_ds
= dm_deferred_set_create();
2584 if (!pool
->shared_read_ds
) {
2585 *error
= "Error creating pool's shared read deferred set";
2586 err_p
= ERR_PTR(-ENOMEM
);
2587 goto bad_shared_read_ds
;
2590 pool
->all_io_ds
= dm_deferred_set_create();
2591 if (!pool
->all_io_ds
) {
2592 *error
= "Error creating pool's all io deferred set";
2593 err_p
= ERR_PTR(-ENOMEM
);
2597 pool
->next_mapping
= NULL
;
2598 pool
->mapping_pool
= mempool_create_slab_pool(MAPPING_POOL_SIZE
,
2599 _new_mapping_cache
);
2600 if (!pool
->mapping_pool
) {
2601 *error
= "Error creating pool's mapping mempool";
2602 err_p
= ERR_PTR(-ENOMEM
);
2603 goto bad_mapping_pool
;
2606 pool
->ref_count
= 1;
2607 pool
->last_commit_jiffies
= jiffies
;
2608 pool
->pool_md
= pool_md
;
2609 pool
->md_dev
= metadata_dev
;
2610 __pool_table_insert(pool
);
2615 dm_deferred_set_destroy(pool
->all_io_ds
);
2617 dm_deferred_set_destroy(pool
->shared_read_ds
);
2619 destroy_workqueue(pool
->wq
);
2621 dm_kcopyd_client_destroy(pool
->copier
);
2623 dm_bio_prison_destroy(pool
->prison
);
2627 if (dm_pool_metadata_close(pmd
))
2628 DMWARN("%s: dm_pool_metadata_close() failed.", __func__
);
2633 static void __pool_inc(struct pool
*pool
)
2635 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
2639 static void __pool_dec(struct pool
*pool
)
2641 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
2642 BUG_ON(!pool
->ref_count
);
2643 if (!--pool
->ref_count
)
2644 __pool_destroy(pool
);
2647 static struct pool
*__pool_find(struct mapped_device
*pool_md
,
2648 struct block_device
*metadata_dev
,
2649 unsigned long block_size
, int read_only
,
2650 char **error
, int *created
)
2652 struct pool
*pool
= __pool_table_lookup_metadata_dev(metadata_dev
);
2655 if (pool
->pool_md
!= pool_md
) {
2656 *error
= "metadata device already in use by a pool";
2657 return ERR_PTR(-EBUSY
);
2662 pool
= __pool_table_lookup(pool_md
);
2664 if (pool
->md_dev
!= metadata_dev
) {
2665 *error
= "different pool cannot replace a pool";
2666 return ERR_PTR(-EINVAL
);
2671 pool
= pool_create(pool_md
, metadata_dev
, block_size
, read_only
, error
);
2679 /*----------------------------------------------------------------
2680 * Pool target methods
2681 *--------------------------------------------------------------*/
2682 static void pool_dtr(struct dm_target
*ti
)
2684 struct pool_c
*pt
= ti
->private;
2686 mutex_lock(&dm_thin_pool_table
.mutex
);
2688 unbind_control_target(pt
->pool
, ti
);
2689 __pool_dec(pt
->pool
);
2690 dm_put_device(ti
, pt
->metadata_dev
);
2691 dm_put_device(ti
, pt
->data_dev
);
2694 mutex_unlock(&dm_thin_pool_table
.mutex
);
2697 static int parse_pool_features(struct dm_arg_set
*as
, struct pool_features
*pf
,
2698 struct dm_target
*ti
)
2702 const char *arg_name
;
2704 static struct dm_arg _args
[] = {
2705 {0, 4, "Invalid number of pool feature arguments"},
2709 * No feature arguments supplied.
2714 r
= dm_read_arg_group(_args
, as
, &argc
, &ti
->error
);
2718 while (argc
&& !r
) {
2719 arg_name
= dm_shift_arg(as
);
2722 if (!strcasecmp(arg_name
, "skip_block_zeroing"))
2723 pf
->zero_new_blocks
= false;
2725 else if (!strcasecmp(arg_name
, "ignore_discard"))
2726 pf
->discard_enabled
= false;
2728 else if (!strcasecmp(arg_name
, "no_discard_passdown"))
2729 pf
->discard_passdown
= false;
2731 else if (!strcasecmp(arg_name
, "read_only"))
2732 pf
->mode
= PM_READ_ONLY
;
2734 else if (!strcasecmp(arg_name
, "error_if_no_space"))
2735 pf
->error_if_no_space
= true;
2738 ti
->error
= "Unrecognised pool feature requested";
2747 static void metadata_low_callback(void *context
)
2749 struct pool
*pool
= context
;
2751 DMWARN("%s: reached low water mark for metadata device: sending event.",
2752 dm_device_name(pool
->pool_md
));
2754 dm_table_event(pool
->ti
->table
);
2757 static sector_t
get_dev_size(struct block_device
*bdev
)
2759 return i_size_read(bdev
->bd_inode
) >> SECTOR_SHIFT
;
2762 static void warn_if_metadata_device_too_big(struct block_device
*bdev
)
2764 sector_t metadata_dev_size
= get_dev_size(bdev
);
2765 char buffer
[BDEVNAME_SIZE
];
2767 if (metadata_dev_size
> THIN_METADATA_MAX_SECTORS_WARNING
)
2768 DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",
2769 bdevname(bdev
, buffer
), THIN_METADATA_MAX_SECTORS
);
2772 static sector_t
get_metadata_dev_size(struct block_device
*bdev
)
2774 sector_t metadata_dev_size
= get_dev_size(bdev
);
2776 if (metadata_dev_size
> THIN_METADATA_MAX_SECTORS
)
2777 metadata_dev_size
= THIN_METADATA_MAX_SECTORS
;
2779 return metadata_dev_size
;
2782 static dm_block_t
get_metadata_dev_size_in_blocks(struct block_device
*bdev
)
2784 sector_t metadata_dev_size
= get_metadata_dev_size(bdev
);
2786 sector_div(metadata_dev_size
, THIN_METADATA_BLOCK_SIZE
);
2788 return metadata_dev_size
;
2792 * When a metadata threshold is crossed a dm event is triggered, and
2793 * userland should respond by growing the metadata device. We could let
2794 * userland set the threshold, like we do with the data threshold, but I'm
2795 * not sure they know enough to do this well.
2797 static dm_block_t
calc_metadata_threshold(struct pool_c
*pt
)
2800 * 4M is ample for all ops with the possible exception of thin
2801 * device deletion which is harmless if it fails (just retry the
2802 * delete after you've grown the device).
2804 dm_block_t quarter
= get_metadata_dev_size_in_blocks(pt
->metadata_dev
->bdev
) / 4;
2805 return min((dm_block_t
)1024ULL /* 4M */, quarter
);
2809 * thin-pool <metadata dev> <data dev>
2810 * <data block size (sectors)>
2811 * <low water mark (blocks)>
2812 * [<#feature args> [<arg>]*]
2814 * Optional feature arguments are:
2815 * skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
2816 * ignore_discard: disable discard
2817 * no_discard_passdown: don't pass discards down to the data device
2818 * read_only: Don't allow any changes to be made to the pool metadata.
2819 * error_if_no_space: error IOs, instead of queueing, if no space.
2821 static int pool_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
2823 int r
, pool_created
= 0;
2826 struct pool_features pf
;
2827 struct dm_arg_set as
;
2828 struct dm_dev
*data_dev
;
2829 unsigned long block_size
;
2830 dm_block_t low_water_blocks
;
2831 struct dm_dev
*metadata_dev
;
2832 fmode_t metadata_mode
;
2835 * FIXME Remove validation from scope of lock.
2837 mutex_lock(&dm_thin_pool_table
.mutex
);
2840 ti
->error
= "Invalid argument count";
2849 * Set default pool features.
2851 pool_features_init(&pf
);
2853 dm_consume_args(&as
, 4);
2854 r
= parse_pool_features(&as
, &pf
, ti
);
2858 metadata_mode
= FMODE_READ
| ((pf
.mode
== PM_READ_ONLY
) ? 0 : FMODE_WRITE
);
2859 r
= dm_get_device(ti
, argv
[0], metadata_mode
, &metadata_dev
);
2861 ti
->error
= "Error opening metadata block device";
2864 warn_if_metadata_device_too_big(metadata_dev
->bdev
);
2866 r
= dm_get_device(ti
, argv
[1], FMODE_READ
| FMODE_WRITE
, &data_dev
);
2868 ti
->error
= "Error getting data device";
2872 if (kstrtoul(argv
[2], 10, &block_size
) || !block_size
||
2873 block_size
< DATA_DEV_BLOCK_SIZE_MIN_SECTORS
||
2874 block_size
> DATA_DEV_BLOCK_SIZE_MAX_SECTORS
||
2875 block_size
& (DATA_DEV_BLOCK_SIZE_MIN_SECTORS
- 1)) {
2876 ti
->error
= "Invalid block size";
2881 if (kstrtoull(argv
[3], 10, (unsigned long long *)&low_water_blocks
)) {
2882 ti
->error
= "Invalid low water mark";
2887 pt
= kzalloc(sizeof(*pt
), GFP_KERNEL
);
2893 pool
= __pool_find(dm_table_get_md(ti
->table
), metadata_dev
->bdev
,
2894 block_size
, pf
.mode
== PM_READ_ONLY
, &ti
->error
, &pool_created
);
2901 * 'pool_created' reflects whether this is the first table load.
2902 * Top level discard support is not allowed to be changed after
2903 * initial load. This would require a pool reload to trigger thin
2906 if (!pool_created
&& pf
.discard_enabled
!= pool
->pf
.discard_enabled
) {
2907 ti
->error
= "Discard support cannot be disabled once enabled";
2909 goto out_flags_changed
;
2914 pt
->metadata_dev
= metadata_dev
;
2915 pt
->data_dev
= data_dev
;
2916 pt
->low_water_blocks
= low_water_blocks
;
2917 pt
->adjusted_pf
= pt
->requested_pf
= pf
;
2918 ti
->num_flush_bios
= 1;
2921 * Only need to enable discards if the pool should pass
2922 * them down to the data device. The thin device's discard
2923 * processing will cause mappings to be removed from the btree.
2925 ti
->discard_zeroes_data_unsupported
= true;
2926 if (pf
.discard_enabled
&& pf
.discard_passdown
) {
2927 ti
->num_discard_bios
= 1;
2930 * Setting 'discards_supported' circumvents the normal
2931 * stacking of discard limits (this keeps the pool and
2932 * thin devices' discard limits consistent).
2934 ti
->discards_supported
= true;
2938 r
= dm_pool_register_metadata_threshold(pt
->pool
->pmd
,
2939 calc_metadata_threshold(pt
),
2940 metadata_low_callback
,
2945 pt
->callbacks
.congested_fn
= pool_is_congested
;
2946 dm_table_add_target_callbacks(ti
->table
, &pt
->callbacks
);
2948 mutex_unlock(&dm_thin_pool_table
.mutex
);
2957 dm_put_device(ti
, data_dev
);
2959 dm_put_device(ti
, metadata_dev
);
2961 mutex_unlock(&dm_thin_pool_table
.mutex
);
2966 static int pool_map(struct dm_target
*ti
, struct bio
*bio
)
2969 struct pool_c
*pt
= ti
->private;
2970 struct pool
*pool
= pt
->pool
;
2971 unsigned long flags
;
2974 * As this is a singleton target, ti->begin is always zero.
2976 spin_lock_irqsave(&pool
->lock
, flags
);
2977 bio
->bi_bdev
= pt
->data_dev
->bdev
;
2978 r
= DM_MAPIO_REMAPPED
;
2979 spin_unlock_irqrestore(&pool
->lock
, flags
);
2984 static int maybe_resize_data_dev(struct dm_target
*ti
, bool *need_commit
)
2987 struct pool_c
*pt
= ti
->private;
2988 struct pool
*pool
= pt
->pool
;
2989 sector_t data_size
= ti
->len
;
2990 dm_block_t sb_data_size
;
2992 *need_commit
= false;
2994 (void) sector_div(data_size
, pool
->sectors_per_block
);
2996 r
= dm_pool_get_data_dev_size(pool
->pmd
, &sb_data_size
);
2998 DMERR("%s: failed to retrieve data device size",
2999 dm_device_name(pool
->pool_md
));
3003 if (data_size
< sb_data_size
) {
3004 DMERR("%s: pool target (%llu blocks) too small: expected %llu",
3005 dm_device_name(pool
->pool_md
),
3006 (unsigned long long)data_size
, sb_data_size
);
3009 } else if (data_size
> sb_data_size
) {
3010 if (dm_pool_metadata_needs_check(pool
->pmd
)) {
3011 DMERR("%s: unable to grow the data device until repaired.",
3012 dm_device_name(pool
->pool_md
));
3017 DMINFO("%s: growing the data device from %llu to %llu blocks",
3018 dm_device_name(pool
->pool_md
),
3019 sb_data_size
, (unsigned long long)data_size
);
3020 r
= dm_pool_resize_data_dev(pool
->pmd
, data_size
);
3022 metadata_operation_failed(pool
, "dm_pool_resize_data_dev", r
);
3026 *need_commit
= true;
3032 static int maybe_resize_metadata_dev(struct dm_target
*ti
, bool *need_commit
)
3035 struct pool_c
*pt
= ti
->private;
3036 struct pool
*pool
= pt
->pool
;
3037 dm_block_t metadata_dev_size
, sb_metadata_dev_size
;
3039 *need_commit
= false;
3041 metadata_dev_size
= get_metadata_dev_size_in_blocks(pool
->md_dev
);
3043 r
= dm_pool_get_metadata_dev_size(pool
->pmd
, &sb_metadata_dev_size
);
3045 DMERR("%s: failed to retrieve metadata device size",
3046 dm_device_name(pool
->pool_md
));
3050 if (metadata_dev_size
< sb_metadata_dev_size
) {
3051 DMERR("%s: metadata device (%llu blocks) too small: expected %llu",
3052 dm_device_name(pool
->pool_md
),
3053 metadata_dev_size
, sb_metadata_dev_size
);
3056 } else if (metadata_dev_size
> sb_metadata_dev_size
) {
3057 if (dm_pool_metadata_needs_check(pool
->pmd
)) {
3058 DMERR("%s: unable to grow the metadata device until repaired.",
3059 dm_device_name(pool
->pool_md
));
3063 warn_if_metadata_device_too_big(pool
->md_dev
);
3064 DMINFO("%s: growing the metadata device from %llu to %llu blocks",
3065 dm_device_name(pool
->pool_md
),
3066 sb_metadata_dev_size
, metadata_dev_size
);
3067 r
= dm_pool_resize_metadata_dev(pool
->pmd
, metadata_dev_size
);
3069 metadata_operation_failed(pool
, "dm_pool_resize_metadata_dev", r
);
3073 *need_commit
= true;
3080 * Retrieves the number of blocks of the data device from
3081 * the superblock and compares it to the actual device size,
3082 * thus resizing the data device in case it has grown.
3084 * This both copes with opening preallocated data devices in the ctr
3085 * being followed by a resume
3087 * calling the resume method individually after userspace has
3088 * grown the data device in reaction to a table event.
3090 static int pool_preresume(struct dm_target
*ti
)
3093 bool need_commit1
, need_commit2
;
3094 struct pool_c
*pt
= ti
->private;
3095 struct pool
*pool
= pt
->pool
;
3098 * Take control of the pool object.
3100 r
= bind_control_target(pool
, ti
);
3104 r
= maybe_resize_data_dev(ti
, &need_commit1
);
3108 r
= maybe_resize_metadata_dev(ti
, &need_commit2
);
3112 if (need_commit1
|| need_commit2
)
3113 (void) commit(pool
);
3118 static void pool_suspend_active_thins(struct pool
*pool
)
3122 /* Suspend all active thin devices */
3123 tc
= get_first_thin(pool
);
3125 dm_internal_suspend_noflush(tc
->thin_md
);
3126 tc
= get_next_thin(pool
, tc
);
3130 static void pool_resume_active_thins(struct pool
*pool
)
3134 /* Resume all active thin devices */
3135 tc
= get_first_thin(pool
);
3137 dm_internal_resume(tc
->thin_md
);
3138 tc
= get_next_thin(pool
, tc
);
3142 static void pool_resume(struct dm_target
*ti
)
3144 struct pool_c
*pt
= ti
->private;
3145 struct pool
*pool
= pt
->pool
;
3146 unsigned long flags
;
3149 * Must requeue active_thins' bios and then resume
3150 * active_thins _before_ clearing 'suspend' flag.
3153 pool_resume_active_thins(pool
);
3155 spin_lock_irqsave(&pool
->lock
, flags
);
3156 pool
->low_water_triggered
= false;
3157 pool
->suspended
= false;
3158 spin_unlock_irqrestore(&pool
->lock
, flags
);
3160 do_waker(&pool
->waker
.work
);
3163 static void pool_presuspend(struct dm_target
*ti
)
3165 struct pool_c
*pt
= ti
->private;
3166 struct pool
*pool
= pt
->pool
;
3167 unsigned long flags
;
3169 spin_lock_irqsave(&pool
->lock
, flags
);
3170 pool
->suspended
= true;
3171 spin_unlock_irqrestore(&pool
->lock
, flags
);
3173 pool_suspend_active_thins(pool
);
3176 static void pool_presuspend_undo(struct dm_target
*ti
)
3178 struct pool_c
*pt
= ti
->private;
3179 struct pool
*pool
= pt
->pool
;
3180 unsigned long flags
;
3182 pool_resume_active_thins(pool
);
3184 spin_lock_irqsave(&pool
->lock
, flags
);
3185 pool
->suspended
= false;
3186 spin_unlock_irqrestore(&pool
->lock
, flags
);
3189 static void pool_postsuspend(struct dm_target
*ti
)
3191 struct pool_c
*pt
= ti
->private;
3192 struct pool
*pool
= pt
->pool
;
3194 cancel_delayed_work(&pool
->waker
);
3195 cancel_delayed_work(&pool
->no_space_timeout
);
3196 flush_workqueue(pool
->wq
);
3197 (void) commit(pool
);
3200 static int check_arg_count(unsigned argc
, unsigned args_required
)
3202 if (argc
!= args_required
) {
3203 DMWARN("Message received with %u arguments instead of %u.",
3204 argc
, args_required
);
3211 static int read_dev_id(char *arg
, dm_thin_id
*dev_id
, int warning
)
3213 if (!kstrtoull(arg
, 10, (unsigned long long *)dev_id
) &&
3214 *dev_id
<= MAX_DEV_ID
)
3218 DMWARN("Message received with invalid device id: %s", arg
);
3223 static int process_create_thin_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3228 r
= check_arg_count(argc
, 2);
3232 r
= read_dev_id(argv
[1], &dev_id
, 1);
3236 r
= dm_pool_create_thin(pool
->pmd
, dev_id
);
3238 DMWARN("Creation of new thinly-provisioned device with id %s failed.",
3246 static int process_create_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3249 dm_thin_id origin_dev_id
;
3252 r
= check_arg_count(argc
, 3);
3256 r
= read_dev_id(argv
[1], &dev_id
, 1);
3260 r
= read_dev_id(argv
[2], &origin_dev_id
, 1);
3264 r
= dm_pool_create_snap(pool
->pmd
, dev_id
, origin_dev_id
);
3266 DMWARN("Creation of new snapshot %s of device %s failed.",
3274 static int process_delete_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3279 r
= check_arg_count(argc
, 2);
3283 r
= read_dev_id(argv
[1], &dev_id
, 1);
3287 r
= dm_pool_delete_thin_device(pool
->pmd
, dev_id
);
3289 DMWARN("Deletion of thin device %s failed.", argv
[1]);
3294 static int process_set_transaction_id_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3296 dm_thin_id old_id
, new_id
;
3299 r
= check_arg_count(argc
, 3);
3303 if (kstrtoull(argv
[1], 10, (unsigned long long *)&old_id
)) {
3304 DMWARN("set_transaction_id message: Unrecognised id %s.", argv
[1]);
3308 if (kstrtoull(argv
[2], 10, (unsigned long long *)&new_id
)) {
3309 DMWARN("set_transaction_id message: Unrecognised new id %s.", argv
[2]);
3313 r
= dm_pool_set_metadata_transaction_id(pool
->pmd
, old_id
, new_id
);
3315 DMWARN("Failed to change transaction id from %s to %s.",
3323 static int process_reserve_metadata_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3327 r
= check_arg_count(argc
, 1);
3331 (void) commit(pool
);
3333 r
= dm_pool_reserve_metadata_snap(pool
->pmd
);
3335 DMWARN("reserve_metadata_snap message failed.");
3340 static int process_release_metadata_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3344 r
= check_arg_count(argc
, 1);
3348 r
= dm_pool_release_metadata_snap(pool
->pmd
);
3350 DMWARN("release_metadata_snap message failed.");
3356 * Messages supported:
3357 * create_thin <dev_id>
3358 * create_snap <dev_id> <origin_id>
3360 * set_transaction_id <current_trans_id> <new_trans_id>
3361 * reserve_metadata_snap
3362 * release_metadata_snap
3364 static int pool_message(struct dm_target
*ti
, unsigned argc
, char **argv
)
3367 struct pool_c
*pt
= ti
->private;
3368 struct pool
*pool
= pt
->pool
;
3370 if (!strcasecmp(argv
[0], "create_thin"))
3371 r
= process_create_thin_mesg(argc
, argv
, pool
);
3373 else if (!strcasecmp(argv
[0], "create_snap"))
3374 r
= process_create_snap_mesg(argc
, argv
, pool
);
3376 else if (!strcasecmp(argv
[0], "delete"))
3377 r
= process_delete_mesg(argc
, argv
, pool
);
3379 else if (!strcasecmp(argv
[0], "set_transaction_id"))
3380 r
= process_set_transaction_id_mesg(argc
, argv
, pool
);
3382 else if (!strcasecmp(argv
[0], "reserve_metadata_snap"))
3383 r
= process_reserve_metadata_snap_mesg(argc
, argv
, pool
);
3385 else if (!strcasecmp(argv
[0], "release_metadata_snap"))
3386 r
= process_release_metadata_snap_mesg(argc
, argv
, pool
);
3389 DMWARN("Unrecognised thin pool target message received: %s", argv
[0]);
3392 (void) commit(pool
);
3397 static void emit_flags(struct pool_features
*pf
, char *result
,
3398 unsigned sz
, unsigned maxlen
)
3400 unsigned count
= !pf
->zero_new_blocks
+ !pf
->discard_enabled
+
3401 !pf
->discard_passdown
+ (pf
->mode
== PM_READ_ONLY
) +
3402 pf
->error_if_no_space
;
3403 DMEMIT("%u ", count
);
3405 if (!pf
->zero_new_blocks
)
3406 DMEMIT("skip_block_zeroing ");
3408 if (!pf
->discard_enabled
)
3409 DMEMIT("ignore_discard ");
3411 if (!pf
->discard_passdown
)
3412 DMEMIT("no_discard_passdown ");
3414 if (pf
->mode
== PM_READ_ONLY
)
3415 DMEMIT("read_only ");
3417 if (pf
->error_if_no_space
)
3418 DMEMIT("error_if_no_space ");
3423 * <transaction id> <used metadata sectors>/<total metadata sectors>
3424 * <used data sectors>/<total data sectors> <held metadata root>
3426 static void pool_status(struct dm_target
*ti
, status_type_t type
,
3427 unsigned status_flags
, char *result
, unsigned maxlen
)
3431 uint64_t transaction_id
;
3432 dm_block_t nr_free_blocks_data
;
3433 dm_block_t nr_free_blocks_metadata
;
3434 dm_block_t nr_blocks_data
;
3435 dm_block_t nr_blocks_metadata
;
3436 dm_block_t held_root
;
3437 char buf
[BDEVNAME_SIZE
];
3438 char buf2
[BDEVNAME_SIZE
];
3439 struct pool_c
*pt
= ti
->private;
3440 struct pool
*pool
= pt
->pool
;
3443 case STATUSTYPE_INFO
:
3444 if (get_pool_mode(pool
) == PM_FAIL
) {
3449 /* Commit to ensure statistics aren't out-of-date */
3450 if (!(status_flags
& DM_STATUS_NOFLUSH_FLAG
) && !dm_suspended(ti
))
3451 (void) commit(pool
);
3453 r
= dm_pool_get_metadata_transaction_id(pool
->pmd
, &transaction_id
);
3455 DMERR("%s: dm_pool_get_metadata_transaction_id returned %d",
3456 dm_device_name(pool
->pool_md
), r
);
3460 r
= dm_pool_get_free_metadata_block_count(pool
->pmd
, &nr_free_blocks_metadata
);
3462 DMERR("%s: dm_pool_get_free_metadata_block_count returned %d",
3463 dm_device_name(pool
->pool_md
), r
);
3467 r
= dm_pool_get_metadata_dev_size(pool
->pmd
, &nr_blocks_metadata
);
3469 DMERR("%s: dm_pool_get_metadata_dev_size returned %d",
3470 dm_device_name(pool
->pool_md
), r
);
3474 r
= dm_pool_get_free_block_count(pool
->pmd
, &nr_free_blocks_data
);
3476 DMERR("%s: dm_pool_get_free_block_count returned %d",
3477 dm_device_name(pool
->pool_md
), r
);
3481 r
= dm_pool_get_data_dev_size(pool
->pmd
, &nr_blocks_data
);
3483 DMERR("%s: dm_pool_get_data_dev_size returned %d",
3484 dm_device_name(pool
->pool_md
), r
);
3488 r
= dm_pool_get_metadata_snap(pool
->pmd
, &held_root
);
3490 DMERR("%s: dm_pool_get_metadata_snap returned %d",
3491 dm_device_name(pool
->pool_md
), r
);
3495 DMEMIT("%llu %llu/%llu %llu/%llu ",
3496 (unsigned long long)transaction_id
,
3497 (unsigned long long)(nr_blocks_metadata
- nr_free_blocks_metadata
),
3498 (unsigned long long)nr_blocks_metadata
,
3499 (unsigned long long)(nr_blocks_data
- nr_free_blocks_data
),
3500 (unsigned long long)nr_blocks_data
);
3503 DMEMIT("%llu ", held_root
);
3507 if (pool
->pf
.mode
== PM_OUT_OF_DATA_SPACE
)
3508 DMEMIT("out_of_data_space ");
3509 else if (pool
->pf
.mode
== PM_READ_ONLY
)
3514 if (!pool
->pf
.discard_enabled
)
3515 DMEMIT("ignore_discard ");
3516 else if (pool
->pf
.discard_passdown
)
3517 DMEMIT("discard_passdown ");
3519 DMEMIT("no_discard_passdown ");
3521 if (pool
->pf
.error_if_no_space
)
3522 DMEMIT("error_if_no_space ");
3524 DMEMIT("queue_if_no_space ");
3528 case STATUSTYPE_TABLE
:
3529 DMEMIT("%s %s %lu %llu ",
3530 format_dev_t(buf
, pt
->metadata_dev
->bdev
->bd_dev
),
3531 format_dev_t(buf2
, pt
->data_dev
->bdev
->bd_dev
),
3532 (unsigned long)pool
->sectors_per_block
,
3533 (unsigned long long)pt
->low_water_blocks
);
3534 emit_flags(&pt
->requested_pf
, result
, sz
, maxlen
);
3543 static int pool_iterate_devices(struct dm_target
*ti
,
3544 iterate_devices_callout_fn fn
, void *data
)
3546 struct pool_c
*pt
= ti
->private;
3548 return fn(ti
, pt
->data_dev
, 0, ti
->len
, data
);
3551 static int pool_merge(struct dm_target
*ti
, struct bvec_merge_data
*bvm
,
3552 struct bio_vec
*biovec
, int max_size
)
3554 struct pool_c
*pt
= ti
->private;
3555 struct request_queue
*q
= bdev_get_queue(pt
->data_dev
->bdev
);
3557 if (!q
->merge_bvec_fn
)
3560 bvm
->bi_bdev
= pt
->data_dev
->bdev
;
3562 return min(max_size
, q
->merge_bvec_fn(q
, bvm
, biovec
));
3565 static void set_discard_limits(struct pool_c
*pt
, struct queue_limits
*limits
)
3567 struct pool
*pool
= pt
->pool
;
3568 struct queue_limits
*data_limits
;
3570 limits
->max_discard_sectors
= pool
->sectors_per_block
;
3573 * discard_granularity is just a hint, and not enforced.
3575 if (pt
->adjusted_pf
.discard_passdown
) {
3576 data_limits
= &bdev_get_queue(pt
->data_dev
->bdev
)->limits
;
3577 limits
->discard_granularity
= max(data_limits
->discard_granularity
,
3578 pool
->sectors_per_block
<< SECTOR_SHIFT
);
3580 limits
->discard_granularity
= pool
->sectors_per_block
<< SECTOR_SHIFT
;
3583 static void pool_io_hints(struct dm_target
*ti
, struct queue_limits
*limits
)
3585 struct pool_c
*pt
= ti
->private;
3586 struct pool
*pool
= pt
->pool
;
3587 sector_t io_opt_sectors
= limits
->io_opt
>> SECTOR_SHIFT
;
3590 * If max_sectors is smaller than pool->sectors_per_block adjust it
3591 * to the highest possible power-of-2 factor of pool->sectors_per_block.
3592 * This is especially beneficial when the pool's data device is a RAID
3593 * device that has a full stripe width that matches pool->sectors_per_block
3594 * -- because even though partial RAID stripe-sized IOs will be issued to a
3595 * single RAID stripe; when aggregated they will end on a full RAID stripe
3596 * boundary.. which avoids additional partial RAID stripe writes cascading
3598 if (limits
->max_sectors
< pool
->sectors_per_block
) {
3599 while (!is_factor(pool
->sectors_per_block
, limits
->max_sectors
)) {
3600 if ((limits
->max_sectors
& (limits
->max_sectors
- 1)) == 0)
3601 limits
->max_sectors
--;
3602 limits
->max_sectors
= rounddown_pow_of_two(limits
->max_sectors
);
3607 * If the system-determined stacked limits are compatible with the
3608 * pool's blocksize (io_opt is a factor) do not override them.
3610 if (io_opt_sectors
< pool
->sectors_per_block
||
3611 !is_factor(io_opt_sectors
, pool
->sectors_per_block
)) {
3612 if (is_factor(pool
->sectors_per_block
, limits
->max_sectors
))
3613 blk_limits_io_min(limits
, limits
->max_sectors
<< SECTOR_SHIFT
);
3615 blk_limits_io_min(limits
, pool
->sectors_per_block
<< SECTOR_SHIFT
);
3616 blk_limits_io_opt(limits
, pool
->sectors_per_block
<< SECTOR_SHIFT
);
3620 * pt->adjusted_pf is a staging area for the actual features to use.
3621 * They get transferred to the live pool in bind_control_target()
3622 * called from pool_preresume().
3624 if (!pt
->adjusted_pf
.discard_enabled
) {
3626 * Must explicitly disallow stacking discard limits otherwise the
3627 * block layer will stack them if pool's data device has support.
3628 * QUEUE_FLAG_DISCARD wouldn't be set but there is no way for the
3629 * user to see that, so make sure to set all discard limits to 0.
3631 limits
->discard_granularity
= 0;
3635 disable_passdown_if_not_supported(pt
);
3637 set_discard_limits(pt
, limits
);
3640 static struct target_type pool_target
= {
3641 .name
= "thin-pool",
3642 .features
= DM_TARGET_SINGLETON
| DM_TARGET_ALWAYS_WRITEABLE
|
3643 DM_TARGET_IMMUTABLE
,
3644 .version
= {1, 14, 0},
3645 .module
= THIS_MODULE
,
3649 .presuspend
= pool_presuspend
,
3650 .presuspend_undo
= pool_presuspend_undo
,
3651 .postsuspend
= pool_postsuspend
,
3652 .preresume
= pool_preresume
,
3653 .resume
= pool_resume
,
3654 .message
= pool_message
,
3655 .status
= pool_status
,
3656 .merge
= pool_merge
,
3657 .iterate_devices
= pool_iterate_devices
,
3658 .io_hints
= pool_io_hints
,
3661 /*----------------------------------------------------------------
3662 * Thin target methods
3663 *--------------------------------------------------------------*/
3664 static void thin_get(struct thin_c
*tc
)
3666 atomic_inc(&tc
->refcount
);
3669 static void thin_put(struct thin_c
*tc
)
3671 if (atomic_dec_and_test(&tc
->refcount
))
3672 complete(&tc
->can_destroy
);
3675 static void thin_dtr(struct dm_target
*ti
)
3677 struct thin_c
*tc
= ti
->private;
3678 unsigned long flags
;
3680 spin_lock_irqsave(&tc
->pool
->lock
, flags
);
3681 list_del_rcu(&tc
->list
);
3682 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
3686 wait_for_completion(&tc
->can_destroy
);
3688 mutex_lock(&dm_thin_pool_table
.mutex
);
3690 __pool_dec(tc
->pool
);
3691 dm_pool_close_thin_device(tc
->td
);
3692 dm_put_device(ti
, tc
->pool_dev
);
3694 dm_put_device(ti
, tc
->origin_dev
);
3697 mutex_unlock(&dm_thin_pool_table
.mutex
);
3701 * Thin target parameters:
3703 * <pool_dev> <dev_id> [origin_dev]
3705 * pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
3706 * dev_id: the internal device identifier
3707 * origin_dev: a device external to the pool that should act as the origin
3709 * If the pool device has discards disabled, they get disabled for the thin
3712 static int thin_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
3716 struct dm_dev
*pool_dev
, *origin_dev
;
3717 struct mapped_device
*pool_md
;
3718 unsigned long flags
;
3720 mutex_lock(&dm_thin_pool_table
.mutex
);
3722 if (argc
!= 2 && argc
!= 3) {
3723 ti
->error
= "Invalid argument count";
3728 tc
= ti
->private = kzalloc(sizeof(*tc
), GFP_KERNEL
);
3730 ti
->error
= "Out of memory";
3734 tc
->thin_md
= dm_table_get_md(ti
->table
);
3735 spin_lock_init(&tc
->lock
);
3736 INIT_LIST_HEAD(&tc
->deferred_cells
);
3737 bio_list_init(&tc
->deferred_bio_list
);
3738 bio_list_init(&tc
->retry_on_resume_list
);
3739 tc
->sort_bio_list
= RB_ROOT
;
3742 r
= dm_get_device(ti
, argv
[2], FMODE_READ
, &origin_dev
);
3744 ti
->error
= "Error opening origin device";
3745 goto bad_origin_dev
;
3747 tc
->origin_dev
= origin_dev
;
3750 r
= dm_get_device(ti
, argv
[0], dm_table_get_mode(ti
->table
), &pool_dev
);
3752 ti
->error
= "Error opening pool device";
3755 tc
->pool_dev
= pool_dev
;
3757 if (read_dev_id(argv
[1], (unsigned long long *)&tc
->dev_id
, 0)) {
3758 ti
->error
= "Invalid device id";
3763 pool_md
= dm_get_md(tc
->pool_dev
->bdev
->bd_dev
);
3765 ti
->error
= "Couldn't get pool mapped device";
3770 tc
->pool
= __pool_table_lookup(pool_md
);
3772 ti
->error
= "Couldn't find pool object";
3774 goto bad_pool_lookup
;
3776 __pool_inc(tc
->pool
);
3778 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
3779 ti
->error
= "Couldn't open thin device, Pool is in fail mode";
3784 r
= dm_pool_open_thin_device(tc
->pool
->pmd
, tc
->dev_id
, &tc
->td
);
3786 ti
->error
= "Couldn't open thin internal device";
3790 r
= dm_set_target_max_io_len(ti
, tc
->pool
->sectors_per_block
);
3794 ti
->num_flush_bios
= 1;
3795 ti
->flush_supported
= true;
3796 ti
->per_bio_data_size
= sizeof(struct dm_thin_endio_hook
);
3798 /* In case the pool supports discards, pass them on. */
3799 ti
->discard_zeroes_data_unsupported
= true;
3800 if (tc
->pool
->pf
.discard_enabled
) {
3801 ti
->discards_supported
= true;
3802 ti
->num_discard_bios
= 1;
3803 /* Discard bios must be split on a block boundary */
3804 ti
->split_discard_bios
= true;
3807 mutex_unlock(&dm_thin_pool_table
.mutex
);
3809 spin_lock_irqsave(&tc
->pool
->lock
, flags
);
3810 if (tc
->pool
->suspended
) {
3811 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
3812 mutex_lock(&dm_thin_pool_table
.mutex
); /* reacquire for __pool_dec */
3813 ti
->error
= "Unable to activate thin device while pool is suspended";
3817 list_add_tail_rcu(&tc
->list
, &tc
->pool
->active_thins
);
3818 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
3820 * This synchronize_rcu() call is needed here otherwise we risk a
3821 * wake_worker() call finding no bios to process (because the newly
3822 * added tc isn't yet visible). So this reduces latency since we
3823 * aren't then dependent on the periodic commit to wake_worker().
3829 atomic_set(&tc
->refcount
, 1);
3830 init_completion(&tc
->can_destroy
);
3835 dm_pool_close_thin_device(tc
->td
);
3837 __pool_dec(tc
->pool
);
3841 dm_put_device(ti
, tc
->pool_dev
);
3844 dm_put_device(ti
, tc
->origin_dev
);
3848 mutex_unlock(&dm_thin_pool_table
.mutex
);
3853 static int thin_map(struct dm_target
*ti
, struct bio
*bio
)
3855 bio
->bi_iter
.bi_sector
= dm_target_offset(ti
, bio
->bi_iter
.bi_sector
);
3857 return thin_bio_map(ti
, bio
);
3860 static int thin_endio(struct dm_target
*ti
, struct bio
*bio
, int err
)
3862 unsigned long flags
;
3863 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
3864 struct list_head work
;
3865 struct dm_thin_new_mapping
*m
, *tmp
;
3866 struct pool
*pool
= h
->tc
->pool
;
3868 if (h
->shared_read_entry
) {
3869 INIT_LIST_HEAD(&work
);
3870 dm_deferred_entry_dec(h
->shared_read_entry
, &work
);
3872 spin_lock_irqsave(&pool
->lock
, flags
);
3873 list_for_each_entry_safe(m
, tmp
, &work
, list
) {
3875 __complete_mapping_preparation(m
);
3877 spin_unlock_irqrestore(&pool
->lock
, flags
);
3880 if (h
->all_io_entry
) {
3881 INIT_LIST_HEAD(&work
);
3882 dm_deferred_entry_dec(h
->all_io_entry
, &work
);
3883 if (!list_empty(&work
)) {
3884 spin_lock_irqsave(&pool
->lock
, flags
);
3885 list_for_each_entry_safe(m
, tmp
, &work
, list
)
3886 list_add_tail(&m
->list
, &pool
->prepared_discards
);
3887 spin_unlock_irqrestore(&pool
->lock
, flags
);
3895 static void thin_presuspend(struct dm_target
*ti
)
3897 struct thin_c
*tc
= ti
->private;
3899 if (dm_noflush_suspending(ti
))
3900 noflush_work(tc
, do_noflush_start
);
3903 static void thin_postsuspend(struct dm_target
*ti
)
3905 struct thin_c
*tc
= ti
->private;
3908 * The dm_noflush_suspending flag has been cleared by now, so
3909 * unfortunately we must always run this.
3911 noflush_work(tc
, do_noflush_stop
);
3914 static int thin_preresume(struct dm_target
*ti
)
3916 struct thin_c
*tc
= ti
->private;
3919 tc
->origin_size
= get_dev_size(tc
->origin_dev
->bdev
);
3925 * <nr mapped sectors> <highest mapped sector>
3927 static void thin_status(struct dm_target
*ti
, status_type_t type
,
3928 unsigned status_flags
, char *result
, unsigned maxlen
)
3932 dm_block_t mapped
, highest
;
3933 char buf
[BDEVNAME_SIZE
];
3934 struct thin_c
*tc
= ti
->private;
3936 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
3945 case STATUSTYPE_INFO
:
3946 r
= dm_thin_get_mapped_count(tc
->td
, &mapped
);
3948 DMERR("dm_thin_get_mapped_count returned %d", r
);
3952 r
= dm_thin_get_highest_mapped_block(tc
->td
, &highest
);
3954 DMERR("dm_thin_get_highest_mapped_block returned %d", r
);
3958 DMEMIT("%llu ", mapped
* tc
->pool
->sectors_per_block
);
3960 DMEMIT("%llu", ((highest
+ 1) *
3961 tc
->pool
->sectors_per_block
) - 1);
3966 case STATUSTYPE_TABLE
:
3968 format_dev_t(buf
, tc
->pool_dev
->bdev
->bd_dev
),
3969 (unsigned long) tc
->dev_id
);
3971 DMEMIT(" %s", format_dev_t(buf
, tc
->origin_dev
->bdev
->bd_dev
));
3982 static int thin_merge(struct dm_target
*ti
, struct bvec_merge_data
*bvm
,
3983 struct bio_vec
*biovec
, int max_size
)
3985 struct thin_c
*tc
= ti
->private;
3986 struct request_queue
*q
= bdev_get_queue(tc
->pool_dev
->bdev
);
3988 if (!q
->merge_bvec_fn
)
3991 bvm
->bi_bdev
= tc
->pool_dev
->bdev
;
3992 bvm
->bi_sector
= dm_target_offset(ti
, bvm
->bi_sector
);
3994 return min(max_size
, q
->merge_bvec_fn(q
, bvm
, biovec
));
3997 static int thin_iterate_devices(struct dm_target
*ti
,
3998 iterate_devices_callout_fn fn
, void *data
)
4001 struct thin_c
*tc
= ti
->private;
4002 struct pool
*pool
= tc
->pool
;
4005 * We can't call dm_pool_get_data_dev_size() since that blocks. So
4006 * we follow a more convoluted path through to the pool's target.
4009 return 0; /* nothing is bound */
4011 blocks
= pool
->ti
->len
;
4012 (void) sector_div(blocks
, pool
->sectors_per_block
);
4014 return fn(ti
, tc
->pool_dev
, 0, pool
->sectors_per_block
* blocks
, data
);
4019 static struct target_type thin_target
= {
4021 .version
= {1, 14, 0},
4022 .module
= THIS_MODULE
,
4026 .end_io
= thin_endio
,
4027 .preresume
= thin_preresume
,
4028 .presuspend
= thin_presuspend
,
4029 .postsuspend
= thin_postsuspend
,
4030 .status
= thin_status
,
4031 .merge
= thin_merge
,
4032 .iterate_devices
= thin_iterate_devices
,
4035 /*----------------------------------------------------------------*/
4037 static int __init
dm_thin_init(void)
4043 r
= dm_register_target(&thin_target
);
4047 r
= dm_register_target(&pool_target
);
4049 goto bad_pool_target
;
4053 _new_mapping_cache
= KMEM_CACHE(dm_thin_new_mapping
, 0);
4054 if (!_new_mapping_cache
)
4055 goto bad_new_mapping_cache
;
4059 bad_new_mapping_cache
:
4060 dm_unregister_target(&pool_target
);
4062 dm_unregister_target(&thin_target
);
4067 static void dm_thin_exit(void)
4069 dm_unregister_target(&thin_target
);
4070 dm_unregister_target(&pool_target
);
4072 kmem_cache_destroy(_new_mapping_cache
);
4075 module_init(dm_thin_init
);
4076 module_exit(dm_thin_exit
);
4078 module_param_named(no_space_timeout
, no_space_timeout_secs
, uint
, S_IRUGO
| S_IWUSR
);
4079 MODULE_PARM_DESC(no_space_timeout
, "Out of data space queue IO timeout in seconds");
4081 MODULE_DESCRIPTION(DM_NAME
" thin provisioning target");
4082 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
4083 MODULE_LICENSE("GPL");