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/jiffies.h>
15 #include <linux/log2.h>
16 #include <linux/list.h>
17 #include <linux/rculist.h>
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/slab.h>
21 #include <linux/vmalloc.h>
22 #include <linux/sort.h>
23 #include <linux/rbtree.h>
25 #define DM_MSG_PREFIX "thin"
30 #define ENDIO_HOOK_POOL_SIZE 1024
31 #define MAPPING_POOL_SIZE 1024
32 #define COMMIT_PERIOD HZ
33 #define NO_SPACE_TIMEOUT_SECS 60
35 static unsigned no_space_timeout_secs
= NO_SPACE_TIMEOUT_SECS
;
37 DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle
,
38 "A percentage of time allocated for copy on write");
41 * The block size of the device holding pool data must be
42 * between 64KB and 1GB.
44 #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
45 #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
48 * Device id is restricted to 24 bits.
50 #define MAX_DEV_ID ((1 << 24) - 1)
53 * How do we handle breaking sharing of data blocks?
54 * =================================================
56 * We use a standard copy-on-write btree to store the mappings for the
57 * devices (note I'm talking about copy-on-write of the metadata here, not
58 * the data). When you take an internal snapshot you clone the root node
59 * of the origin btree. After this there is no concept of an origin or a
60 * snapshot. They are just two device trees that happen to point to the
63 * When we get a write in we decide if it's to a shared data block using
64 * some timestamp magic. If it is, we have to break sharing.
66 * Let's say we write to a shared block in what was the origin. The
69 * i) plug io further to this physical block. (see bio_prison code).
71 * ii) quiesce any read io to that shared data block. Obviously
72 * including all devices that share this block. (see dm_deferred_set code)
74 * iii) copy the data block to a newly allocate block. This step can be
75 * missed out if the io covers the block. (schedule_copy).
77 * iv) insert the new mapping into the origin's btree
78 * (process_prepared_mapping). This act of inserting breaks some
79 * sharing of btree nodes between the two devices. Breaking sharing only
80 * effects the btree of that specific device. Btrees for the other
81 * devices that share the block never change. The btree for the origin
82 * device as it was after the last commit is untouched, ie. we're using
83 * persistent data structures in the functional programming sense.
85 * v) unplug io to this physical block, including the io that triggered
86 * the breaking of sharing.
88 * Steps (ii) and (iii) occur in parallel.
90 * The metadata _doesn't_ need to be committed before the io continues. We
91 * get away with this because the io is always written to a _new_ block.
92 * If there's a crash, then:
94 * - The origin mapping will point to the old origin block (the shared
95 * one). This will contain the data as it was before the io that triggered
96 * the breaking of sharing came in.
98 * - The snap mapping still points to the old block. As it would after
101 * The downside of this scheme is the timestamp magic isn't perfect, and
102 * will continue to think that data block in the snapshot device is shared
103 * even after the write to the origin has broken sharing. I suspect data
104 * blocks will typically be shared by many different devices, so we're
105 * breaking sharing n + 1 times, rather than n, where n is the number of
106 * devices that reference this data block. At the moment I think the
107 * benefits far, far outweigh the disadvantages.
110 /*----------------------------------------------------------------*/
120 static void build_key(struct dm_thin_device
*td
, enum lock_space ls
,
121 dm_block_t b
, dm_block_t e
, struct dm_cell_key
*key
)
123 key
->virtual = (ls
== VIRTUAL
);
124 key
->dev
= dm_thin_dev_id(td
);
125 key
->block_begin
= b
;
129 static void build_data_key(struct dm_thin_device
*td
, dm_block_t b
,
130 struct dm_cell_key
*key
)
132 build_key(td
, PHYSICAL
, b
, b
+ 1llu, key
);
135 static void build_virtual_key(struct dm_thin_device
*td
, dm_block_t b
,
136 struct dm_cell_key
*key
)
138 build_key(td
, VIRTUAL
, b
, b
+ 1llu, key
);
141 /*----------------------------------------------------------------*/
143 #define THROTTLE_THRESHOLD (1 * HZ)
146 struct rw_semaphore lock
;
147 unsigned long threshold
;
148 bool throttle_applied
;
151 static void throttle_init(struct throttle
*t
)
153 init_rwsem(&t
->lock
);
154 t
->throttle_applied
= false;
157 static void throttle_work_start(struct throttle
*t
)
159 t
->threshold
= jiffies
+ THROTTLE_THRESHOLD
;
162 static void throttle_work_update(struct throttle
*t
)
164 if (!t
->throttle_applied
&& jiffies
> t
->threshold
) {
165 down_write(&t
->lock
);
166 t
->throttle_applied
= true;
170 static void throttle_work_complete(struct throttle
*t
)
172 if (t
->throttle_applied
) {
173 t
->throttle_applied
= false;
178 static void throttle_lock(struct throttle
*t
)
183 static void throttle_unlock(struct throttle
*t
)
188 /*----------------------------------------------------------------*/
191 * A pool device ties together a metadata device and a data device. It
192 * also provides the interface for creating and destroying internal
195 struct dm_thin_new_mapping
;
198 * The pool runs in 4 modes. Ordered in degraded order for comparisons.
201 PM_WRITE
, /* metadata may be changed */
202 PM_OUT_OF_DATA_SPACE
, /* metadata may be changed, though data may not be allocated */
203 PM_READ_ONLY
, /* metadata may not be changed */
204 PM_FAIL
, /* all I/O fails */
207 struct pool_features
{
210 bool zero_new_blocks
:1;
211 bool discard_enabled
:1;
212 bool discard_passdown
:1;
213 bool error_if_no_space
:1;
217 typedef void (*process_bio_fn
)(struct thin_c
*tc
, struct bio
*bio
);
218 typedef void (*process_cell_fn
)(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
);
219 typedef void (*process_mapping_fn
)(struct dm_thin_new_mapping
*m
);
221 #define CELL_SORT_ARRAY_SIZE 8192
224 struct list_head list
;
225 struct dm_target
*ti
; /* Only set if a pool target is bound */
227 struct mapped_device
*pool_md
;
228 struct block_device
*md_dev
;
229 struct dm_pool_metadata
*pmd
;
231 dm_block_t low_water_blocks
;
232 uint32_t sectors_per_block
;
233 int sectors_per_block_shift
;
235 struct pool_features pf
;
236 bool low_water_triggered
:1; /* A dm event has been sent */
239 struct dm_bio_prison
*prison
;
240 struct dm_kcopyd_client
*copier
;
242 struct workqueue_struct
*wq
;
243 struct throttle throttle
;
244 struct work_struct worker
;
245 struct delayed_work waker
;
246 struct delayed_work no_space_timeout
;
248 unsigned long last_commit_jiffies
;
252 struct bio_list deferred_flush_bios
;
253 struct list_head prepared_mappings
;
254 struct list_head prepared_discards
;
255 struct list_head active_thins
;
257 struct dm_deferred_set
*shared_read_ds
;
258 struct dm_deferred_set
*all_io_ds
;
260 struct dm_thin_new_mapping
*next_mapping
;
261 mempool_t
*mapping_pool
;
263 process_bio_fn process_bio
;
264 process_bio_fn process_discard
;
266 process_cell_fn process_cell
;
267 process_cell_fn process_discard_cell
;
269 process_mapping_fn process_prepared_mapping
;
270 process_mapping_fn process_prepared_discard
;
272 struct dm_bio_prison_cell
**cell_sort_array
;
275 static enum pool_mode
get_pool_mode(struct pool
*pool
);
276 static void metadata_operation_failed(struct pool
*pool
, const char *op
, int r
);
279 * Target context for a pool.
282 struct dm_target
*ti
;
284 struct dm_dev
*data_dev
;
285 struct dm_dev
*metadata_dev
;
286 struct dm_target_callbacks callbacks
;
288 dm_block_t low_water_blocks
;
289 struct pool_features requested_pf
; /* Features requested during table load */
290 struct pool_features adjusted_pf
; /* Features used after adjusting for constituent devices */
294 * Target context for a thin.
297 struct list_head list
;
298 struct dm_dev
*pool_dev
;
299 struct dm_dev
*origin_dev
;
300 sector_t origin_size
;
304 struct dm_thin_device
*td
;
305 struct mapped_device
*thin_md
;
309 struct list_head deferred_cells
;
310 struct bio_list deferred_bio_list
;
311 struct bio_list retry_on_resume_list
;
312 struct rb_root sort_bio_list
; /* sorted list of deferred bios */
315 * Ensures the thin is not destroyed until the worker has finished
316 * iterating the active_thins list.
319 struct completion can_destroy
;
322 /*----------------------------------------------------------------*/
325 * __blkdev_issue_discard_async - queue a discard with async completion
326 * @bdev: blockdev to issue discard for
327 * @sector: start sector
328 * @nr_sects: number of sectors to discard
329 * @gfp_mask: memory allocation flags (for bio_alloc)
330 * @flags: BLKDEV_IFL_* flags to control behaviour
331 * @parent_bio: parent discard bio that all sub discards get chained to
334 * Asynchronously issue a discard request for the sectors in question.
335 * NOTE: this variant of blk-core's blkdev_issue_discard() is a stop-gap
336 * that is being kept local to DM thinp until the block changes to allow
337 * late bio splitting land upstream.
339 static int __blkdev_issue_discard_async(struct block_device
*bdev
, sector_t sector
,
340 sector_t nr_sects
, gfp_t gfp_mask
, unsigned long flags
,
341 struct bio
*parent_bio
)
343 struct request_queue
*q
= bdev_get_queue(bdev
);
344 int type
= REQ_WRITE
| REQ_DISCARD
;
345 unsigned int max_discard_sectors
, granularity
;
349 struct blk_plug plug
;
354 if (!blk_queue_discard(q
))
357 /* Zero-sector (unknown) and one-sector granularities are the same. */
358 granularity
= max(q
->limits
.discard_granularity
>> 9, 1U);
359 alignment
= (bdev_discard_alignment(bdev
) >> 9) % granularity
;
362 * Ensure that max_discard_sectors is of the proper
363 * granularity, so that requests stay aligned after a split.
365 max_discard_sectors
= min(q
->limits
.max_discard_sectors
, UINT_MAX
>> 9);
366 max_discard_sectors
-= max_discard_sectors
% granularity
;
367 if (unlikely(!max_discard_sectors
)) {
368 /* Avoid infinite loop below. Being cautious never hurts. */
372 if (flags
& BLKDEV_DISCARD_SECURE
) {
373 if (!blk_queue_secdiscard(q
))
378 blk_start_plug(&plug
);
380 unsigned int req_sects
;
381 sector_t end_sect
, tmp
;
384 * Required bio_put occurs in bio_endio thanks to bio_chain below
386 bio
= bio_alloc(gfp_mask
, 1);
392 req_sects
= min_t(sector_t
, nr_sects
, max_discard_sectors
);
395 * If splitting a request, and the next starting sector would be
396 * misaligned, stop the discard at the previous aligned sector.
398 end_sect
= sector
+ req_sects
;
400 if (req_sects
< nr_sects
&&
401 sector_div(tmp
, granularity
) != alignment
) {
402 end_sect
= end_sect
- alignment
;
403 sector_div(end_sect
, granularity
);
404 end_sect
= end_sect
* granularity
+ alignment
;
405 req_sects
= end_sect
- sector
;
408 bio_chain(bio
, parent_bio
);
410 bio
->bi_iter
.bi_sector
= sector
;
413 bio
->bi_iter
.bi_size
= req_sects
<< 9;
414 nr_sects
-= req_sects
;
417 submit_bio(type
, bio
);
420 * We can loop for a long time in here, if someone does
421 * full device discards (like mkfs). Be nice and allow
422 * us to schedule out to avoid softlocking if preempt
427 blk_finish_plug(&plug
);
432 static bool block_size_is_power_of_two(struct pool
*pool
)
434 return pool
->sectors_per_block_shift
>= 0;
437 static sector_t
block_to_sectors(struct pool
*pool
, dm_block_t b
)
439 return block_size_is_power_of_two(pool
) ?
440 (b
<< pool
->sectors_per_block_shift
) :
441 (b
* pool
->sectors_per_block
);
444 static int issue_discard(struct thin_c
*tc
, dm_block_t data_b
, dm_block_t data_e
,
445 struct bio
*parent_bio
)
447 sector_t s
= block_to_sectors(tc
->pool
, data_b
);
448 sector_t len
= block_to_sectors(tc
->pool
, data_e
- data_b
);
450 return __blkdev_issue_discard_async(tc
->pool_dev
->bdev
, s
, len
,
451 GFP_NOWAIT
, 0, parent_bio
);
454 /*----------------------------------------------------------------*/
457 * wake_worker() is used when new work is queued and when pool_resume is
458 * ready to continue deferred IO processing.
460 static void wake_worker(struct pool
*pool
)
462 queue_work(pool
->wq
, &pool
->worker
);
465 /*----------------------------------------------------------------*/
467 static int bio_detain(struct pool
*pool
, struct dm_cell_key
*key
, struct bio
*bio
,
468 struct dm_bio_prison_cell
**cell_result
)
471 struct dm_bio_prison_cell
*cell_prealloc
;
474 * Allocate a cell from the prison's mempool.
475 * This might block but it can't fail.
477 cell_prealloc
= dm_bio_prison_alloc_cell(pool
->prison
, GFP_NOIO
);
479 r
= dm_bio_detain(pool
->prison
, key
, bio
, cell_prealloc
, cell_result
);
482 * We reused an old cell; we can get rid of
485 dm_bio_prison_free_cell(pool
->prison
, cell_prealloc
);
490 static void cell_release(struct pool
*pool
,
491 struct dm_bio_prison_cell
*cell
,
492 struct bio_list
*bios
)
494 dm_cell_release(pool
->prison
, cell
, bios
);
495 dm_bio_prison_free_cell(pool
->prison
, cell
);
498 static void cell_visit_release(struct pool
*pool
,
499 void (*fn
)(void *, struct dm_bio_prison_cell
*),
501 struct dm_bio_prison_cell
*cell
)
503 dm_cell_visit_release(pool
->prison
, fn
, context
, cell
);
504 dm_bio_prison_free_cell(pool
->prison
, cell
);
507 static void cell_release_no_holder(struct pool
*pool
,
508 struct dm_bio_prison_cell
*cell
,
509 struct bio_list
*bios
)
511 dm_cell_release_no_holder(pool
->prison
, cell
, bios
);
512 dm_bio_prison_free_cell(pool
->prison
, cell
);
515 static void cell_error_with_code(struct pool
*pool
,
516 struct dm_bio_prison_cell
*cell
, int error_code
)
518 dm_cell_error(pool
->prison
, cell
, error_code
);
519 dm_bio_prison_free_cell(pool
->prison
, cell
);
522 static void cell_error(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
524 cell_error_with_code(pool
, cell
, -EIO
);
527 static void cell_success(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
529 cell_error_with_code(pool
, cell
, 0);
532 static void cell_requeue(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
534 cell_error_with_code(pool
, cell
, DM_ENDIO_REQUEUE
);
537 /*----------------------------------------------------------------*/
540 * A global list of pools that uses a struct mapped_device as a key.
542 static struct dm_thin_pool_table
{
544 struct list_head pools
;
545 } dm_thin_pool_table
;
547 static void pool_table_init(void)
549 mutex_init(&dm_thin_pool_table
.mutex
);
550 INIT_LIST_HEAD(&dm_thin_pool_table
.pools
);
553 static void __pool_table_insert(struct pool
*pool
)
555 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
556 list_add(&pool
->list
, &dm_thin_pool_table
.pools
);
559 static void __pool_table_remove(struct pool
*pool
)
561 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
562 list_del(&pool
->list
);
565 static struct pool
*__pool_table_lookup(struct mapped_device
*md
)
567 struct pool
*pool
= NULL
, *tmp
;
569 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
571 list_for_each_entry(tmp
, &dm_thin_pool_table
.pools
, list
) {
572 if (tmp
->pool_md
== md
) {
581 static struct pool
*__pool_table_lookup_metadata_dev(struct block_device
*md_dev
)
583 struct pool
*pool
= NULL
, *tmp
;
585 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
587 list_for_each_entry(tmp
, &dm_thin_pool_table
.pools
, list
) {
588 if (tmp
->md_dev
== md_dev
) {
597 /*----------------------------------------------------------------*/
599 struct dm_thin_endio_hook
{
601 struct dm_deferred_entry
*shared_read_entry
;
602 struct dm_deferred_entry
*all_io_entry
;
603 struct dm_thin_new_mapping
*overwrite_mapping
;
604 struct rb_node rb_node
;
605 struct dm_bio_prison_cell
*cell
;
608 static void __merge_bio_list(struct bio_list
*bios
, struct bio_list
*master
)
610 bio_list_merge(bios
, master
);
611 bio_list_init(master
);
614 static void error_bio_list(struct bio_list
*bios
, int error
)
618 while ((bio
= bio_list_pop(bios
)))
619 bio_endio(bio
, error
);
622 static void error_thin_bio_list(struct thin_c
*tc
, struct bio_list
*master
, int error
)
624 struct bio_list bios
;
627 bio_list_init(&bios
);
629 spin_lock_irqsave(&tc
->lock
, flags
);
630 __merge_bio_list(&bios
, master
);
631 spin_unlock_irqrestore(&tc
->lock
, flags
);
633 error_bio_list(&bios
, error
);
636 static void requeue_deferred_cells(struct thin_c
*tc
)
638 struct pool
*pool
= tc
->pool
;
640 struct list_head cells
;
641 struct dm_bio_prison_cell
*cell
, *tmp
;
643 INIT_LIST_HEAD(&cells
);
645 spin_lock_irqsave(&tc
->lock
, flags
);
646 list_splice_init(&tc
->deferred_cells
, &cells
);
647 spin_unlock_irqrestore(&tc
->lock
, flags
);
649 list_for_each_entry_safe(cell
, tmp
, &cells
, user_list
)
650 cell_requeue(pool
, cell
);
653 static void requeue_io(struct thin_c
*tc
)
655 struct bio_list bios
;
658 bio_list_init(&bios
);
660 spin_lock_irqsave(&tc
->lock
, flags
);
661 __merge_bio_list(&bios
, &tc
->deferred_bio_list
);
662 __merge_bio_list(&bios
, &tc
->retry_on_resume_list
);
663 spin_unlock_irqrestore(&tc
->lock
, flags
);
665 error_bio_list(&bios
, DM_ENDIO_REQUEUE
);
666 requeue_deferred_cells(tc
);
669 static void error_retry_list_with_code(struct pool
*pool
, int error
)
674 list_for_each_entry_rcu(tc
, &pool
->active_thins
, list
)
675 error_thin_bio_list(tc
, &tc
->retry_on_resume_list
, error
);
679 static void error_retry_list(struct pool
*pool
)
681 return error_retry_list_with_code(pool
, -EIO
);
685 * This section of code contains the logic for processing a thin device's IO.
686 * Much of the code depends on pool object resources (lists, workqueues, etc)
687 * but most is exclusively called from the thin target rather than the thin-pool
691 static dm_block_t
get_bio_block(struct thin_c
*tc
, struct bio
*bio
)
693 struct pool
*pool
= tc
->pool
;
694 sector_t block_nr
= bio
->bi_iter
.bi_sector
;
696 if (block_size_is_power_of_two(pool
))
697 block_nr
>>= pool
->sectors_per_block_shift
;
699 (void) sector_div(block_nr
, pool
->sectors_per_block
);
705 * Returns the _complete_ blocks that this bio covers.
707 static void get_bio_block_range(struct thin_c
*tc
, struct bio
*bio
,
708 dm_block_t
*begin
, dm_block_t
*end
)
710 struct pool
*pool
= tc
->pool
;
711 sector_t b
= bio
->bi_iter
.bi_sector
;
712 sector_t e
= b
+ (bio
->bi_iter
.bi_size
>> SECTOR_SHIFT
);
714 b
+= pool
->sectors_per_block
- 1ull; /* so we round up */
716 if (block_size_is_power_of_two(pool
)) {
717 b
>>= pool
->sectors_per_block_shift
;
718 e
>>= pool
->sectors_per_block_shift
;
720 (void) sector_div(b
, pool
->sectors_per_block
);
721 (void) sector_div(e
, pool
->sectors_per_block
);
725 /* Can happen if the bio is within a single block. */
732 static void remap(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
)
734 struct pool
*pool
= tc
->pool
;
735 sector_t bi_sector
= bio
->bi_iter
.bi_sector
;
737 bio
->bi_bdev
= tc
->pool_dev
->bdev
;
738 if (block_size_is_power_of_two(pool
))
739 bio
->bi_iter
.bi_sector
=
740 (block
<< pool
->sectors_per_block_shift
) |
741 (bi_sector
& (pool
->sectors_per_block
- 1));
743 bio
->bi_iter
.bi_sector
= (block
* pool
->sectors_per_block
) +
744 sector_div(bi_sector
, pool
->sectors_per_block
);
747 static void remap_to_origin(struct thin_c
*tc
, struct bio
*bio
)
749 bio
->bi_bdev
= tc
->origin_dev
->bdev
;
752 static int bio_triggers_commit(struct thin_c
*tc
, struct bio
*bio
)
754 return (bio
->bi_rw
& (REQ_FLUSH
| REQ_FUA
)) &&
755 dm_thin_changed_this_transaction(tc
->td
);
758 static void inc_all_io_entry(struct pool
*pool
, struct bio
*bio
)
760 struct dm_thin_endio_hook
*h
;
762 if (bio
->bi_rw
& REQ_DISCARD
)
765 h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
766 h
->all_io_entry
= dm_deferred_entry_inc(pool
->all_io_ds
);
769 static void issue(struct thin_c
*tc
, struct bio
*bio
)
771 struct pool
*pool
= tc
->pool
;
774 if (!bio_triggers_commit(tc
, bio
)) {
775 generic_make_request(bio
);
780 * Complete bio with an error if earlier I/O caused changes to
781 * the metadata that can't be committed e.g, due to I/O errors
782 * on the metadata device.
784 if (dm_thin_aborted_changes(tc
->td
)) {
790 * Batch together any bios that trigger commits and then issue a
791 * single commit for them in process_deferred_bios().
793 spin_lock_irqsave(&pool
->lock
, flags
);
794 bio_list_add(&pool
->deferred_flush_bios
, bio
);
795 spin_unlock_irqrestore(&pool
->lock
, flags
);
798 static void remap_to_origin_and_issue(struct thin_c
*tc
, struct bio
*bio
)
800 remap_to_origin(tc
, bio
);
804 static void remap_and_issue(struct thin_c
*tc
, struct bio
*bio
,
807 remap(tc
, bio
, block
);
811 /*----------------------------------------------------------------*/
814 * Bio endio functions.
816 struct dm_thin_new_mapping
{
817 struct list_head list
;
823 * Track quiescing, copying and zeroing preparation actions. When this
824 * counter hits zero the block is prepared and can be inserted into the
827 atomic_t prepare_actions
;
831 dm_block_t virt_begin
, virt_end
;
832 dm_block_t data_block
;
833 struct dm_bio_prison_cell
*cell
;
836 * If the bio covers the whole area of a block then we can avoid
837 * zeroing or copying. Instead this bio is hooked. The bio will
838 * still be in the cell, so care has to be taken to avoid issuing
842 bio_end_io_t
*saved_bi_end_io
;
845 static void __complete_mapping_preparation(struct dm_thin_new_mapping
*m
)
847 struct pool
*pool
= m
->tc
->pool
;
849 if (atomic_dec_and_test(&m
->prepare_actions
)) {
850 list_add_tail(&m
->list
, &pool
->prepared_mappings
);
855 static void complete_mapping_preparation(struct dm_thin_new_mapping
*m
)
858 struct pool
*pool
= m
->tc
->pool
;
860 spin_lock_irqsave(&pool
->lock
, flags
);
861 __complete_mapping_preparation(m
);
862 spin_unlock_irqrestore(&pool
->lock
, flags
);
865 static void copy_complete(int read_err
, unsigned long write_err
, void *context
)
867 struct dm_thin_new_mapping
*m
= context
;
869 m
->err
= read_err
|| write_err
? -EIO
: 0;
870 complete_mapping_preparation(m
);
873 static void overwrite_endio(struct bio
*bio
, int err
)
875 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
876 struct dm_thin_new_mapping
*m
= h
->overwrite_mapping
;
878 bio
->bi_end_io
= m
->saved_bi_end_io
;
881 complete_mapping_preparation(m
);
884 /*----------------------------------------------------------------*/
891 * Prepared mapping jobs.
895 * This sends the bios in the cell, except the original holder, back
896 * to the deferred_bios list.
898 static void cell_defer_no_holder(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
900 struct pool
*pool
= tc
->pool
;
903 spin_lock_irqsave(&tc
->lock
, flags
);
904 cell_release_no_holder(pool
, cell
, &tc
->deferred_bio_list
);
905 spin_unlock_irqrestore(&tc
->lock
, flags
);
910 static void thin_defer_bio(struct thin_c
*tc
, struct bio
*bio
);
914 struct bio_list defer_bios
;
915 struct bio_list issue_bios
;
918 static void __inc_remap_and_issue_cell(void *context
,
919 struct dm_bio_prison_cell
*cell
)
921 struct remap_info
*info
= context
;
924 while ((bio
= bio_list_pop(&cell
->bios
))) {
925 if (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
))
926 bio_list_add(&info
->defer_bios
, bio
);
928 inc_all_io_entry(info
->tc
->pool
, bio
);
931 * We can't issue the bios with the bio prison lock
932 * held, so we add them to a list to issue on
933 * return from this function.
935 bio_list_add(&info
->issue_bios
, bio
);
940 static void inc_remap_and_issue_cell(struct thin_c
*tc
,
941 struct dm_bio_prison_cell
*cell
,
945 struct remap_info info
;
948 bio_list_init(&info
.defer_bios
);
949 bio_list_init(&info
.issue_bios
);
952 * We have to be careful to inc any bios we're about to issue
953 * before the cell is released, and avoid a race with new bios
954 * being added to the cell.
956 cell_visit_release(tc
->pool
, __inc_remap_and_issue_cell
,
959 while ((bio
= bio_list_pop(&info
.defer_bios
)))
960 thin_defer_bio(tc
, bio
);
962 while ((bio
= bio_list_pop(&info
.issue_bios
)))
963 remap_and_issue(info
.tc
, bio
, block
);
966 static void process_prepared_mapping_fail(struct dm_thin_new_mapping
*m
)
968 cell_error(m
->tc
->pool
, m
->cell
);
970 mempool_free(m
, m
->tc
->pool
->mapping_pool
);
973 static void process_prepared_mapping(struct dm_thin_new_mapping
*m
)
975 struct thin_c
*tc
= m
->tc
;
976 struct pool
*pool
= tc
->pool
;
977 struct bio
*bio
= m
->bio
;
981 cell_error(pool
, m
->cell
);
986 * Commit the prepared block into the mapping btree.
987 * Any I/O for this block arriving after this point will get
988 * remapped to it directly.
990 r
= dm_thin_insert_block(tc
->td
, m
->virt_begin
, m
->data_block
);
992 metadata_operation_failed(pool
, "dm_thin_insert_block", r
);
993 cell_error(pool
, m
->cell
);
998 * Release any bios held while the block was being provisioned.
999 * If we are processing a write bio that completely covers the block,
1000 * we already processed it so can ignore it now when processing
1001 * the bios in the cell.
1004 inc_remap_and_issue_cell(tc
, m
->cell
, m
->data_block
);
1007 inc_all_io_entry(tc
->pool
, m
->cell
->holder
);
1008 remap_and_issue(tc
, m
->cell
->holder
, m
->data_block
);
1009 inc_remap_and_issue_cell(tc
, m
->cell
, m
->data_block
);
1014 mempool_free(m
, pool
->mapping_pool
);
1017 /*----------------------------------------------------------------*/
1019 static void free_discard_mapping(struct dm_thin_new_mapping
*m
)
1021 struct thin_c
*tc
= m
->tc
;
1023 cell_defer_no_holder(tc
, m
->cell
);
1024 mempool_free(m
, tc
->pool
->mapping_pool
);
1027 static void process_prepared_discard_fail(struct dm_thin_new_mapping
*m
)
1029 bio_io_error(m
->bio
);
1030 free_discard_mapping(m
);
1033 static void process_prepared_discard_success(struct dm_thin_new_mapping
*m
)
1035 bio_endio(m
->bio
, 0);
1036 free_discard_mapping(m
);
1039 static void process_prepared_discard_no_passdown(struct dm_thin_new_mapping
*m
)
1042 struct thin_c
*tc
= m
->tc
;
1044 r
= dm_thin_remove_range(tc
->td
, m
->cell
->key
.block_begin
, m
->cell
->key
.block_end
);
1046 metadata_operation_failed(tc
->pool
, "dm_thin_remove_range", r
);
1047 bio_io_error(m
->bio
);
1049 bio_endio(m
->bio
, 0);
1051 cell_defer_no_holder(tc
, m
->cell
);
1052 mempool_free(m
, tc
->pool
->mapping_pool
);
1055 static int passdown_double_checking_shared_status(struct dm_thin_new_mapping
*m
)
1058 * We've already unmapped this range of blocks, but before we
1059 * passdown we have to check that these blocks are now unused.
1063 struct thin_c
*tc
= m
->tc
;
1064 struct pool
*pool
= tc
->pool
;
1065 dm_block_t b
= m
->data_block
, e
, end
= m
->data_block
+ m
->virt_end
- m
->virt_begin
;
1068 /* find start of unmapped run */
1069 for (; b
< end
; b
++) {
1070 r
= dm_pool_block_is_used(pool
->pmd
, b
, &used
);
1081 /* find end of run */
1082 for (e
= b
+ 1; e
!= end
; e
++) {
1083 r
= dm_pool_block_is_used(pool
->pmd
, e
, &used
);
1091 r
= issue_discard(tc
, b
, e
, m
->bio
);
1101 static void process_prepared_discard_passdown(struct dm_thin_new_mapping
*m
)
1104 struct thin_c
*tc
= m
->tc
;
1105 struct pool
*pool
= tc
->pool
;
1107 r
= dm_thin_remove_range(tc
->td
, m
->virt_begin
, m
->virt_end
);
1109 metadata_operation_failed(pool
, "dm_thin_remove_range", r
);
1111 else if (m
->maybe_shared
)
1112 r
= passdown_double_checking_shared_status(m
);
1114 r
= issue_discard(tc
, m
->data_block
, m
->data_block
+ (m
->virt_end
- m
->virt_begin
), m
->bio
);
1117 * Even if r is set, there could be sub discards in flight that we
1120 bio_endio(m
->bio
, r
);
1121 cell_defer_no_holder(tc
, m
->cell
);
1122 mempool_free(m
, pool
->mapping_pool
);
1125 static void process_prepared(struct pool
*pool
, struct list_head
*head
,
1126 process_mapping_fn
*fn
)
1128 unsigned long flags
;
1129 struct list_head maps
;
1130 struct dm_thin_new_mapping
*m
, *tmp
;
1132 INIT_LIST_HEAD(&maps
);
1133 spin_lock_irqsave(&pool
->lock
, flags
);
1134 list_splice_init(head
, &maps
);
1135 spin_unlock_irqrestore(&pool
->lock
, flags
);
1137 list_for_each_entry_safe(m
, tmp
, &maps
, list
)
1142 * Deferred bio jobs.
1144 static int io_overlaps_block(struct pool
*pool
, struct bio
*bio
)
1146 return bio
->bi_iter
.bi_size
==
1147 (pool
->sectors_per_block
<< SECTOR_SHIFT
);
1150 static int io_overwrites_block(struct pool
*pool
, struct bio
*bio
)
1152 return (bio_data_dir(bio
) == WRITE
) &&
1153 io_overlaps_block(pool
, bio
);
1156 static void save_and_set_endio(struct bio
*bio
, bio_end_io_t
**save
,
1159 *save
= bio
->bi_end_io
;
1160 bio
->bi_end_io
= fn
;
1163 static int ensure_next_mapping(struct pool
*pool
)
1165 if (pool
->next_mapping
)
1168 pool
->next_mapping
= mempool_alloc(pool
->mapping_pool
, GFP_ATOMIC
);
1170 return pool
->next_mapping
? 0 : -ENOMEM
;
1173 static struct dm_thin_new_mapping
*get_next_mapping(struct pool
*pool
)
1175 struct dm_thin_new_mapping
*m
= pool
->next_mapping
;
1177 BUG_ON(!pool
->next_mapping
);
1179 memset(m
, 0, sizeof(struct dm_thin_new_mapping
));
1180 INIT_LIST_HEAD(&m
->list
);
1183 pool
->next_mapping
= NULL
;
1188 static void ll_zero(struct thin_c
*tc
, struct dm_thin_new_mapping
*m
,
1189 sector_t begin
, sector_t end
)
1192 struct dm_io_region to
;
1194 to
.bdev
= tc
->pool_dev
->bdev
;
1196 to
.count
= end
- begin
;
1198 r
= dm_kcopyd_zero(tc
->pool
->copier
, 1, &to
, 0, copy_complete
, m
);
1200 DMERR_LIMIT("dm_kcopyd_zero() failed");
1201 copy_complete(1, 1, m
);
1205 static void remap_and_issue_overwrite(struct thin_c
*tc
, struct bio
*bio
,
1206 dm_block_t data_begin
,
1207 struct dm_thin_new_mapping
*m
)
1209 struct pool
*pool
= tc
->pool
;
1210 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1212 h
->overwrite_mapping
= m
;
1214 save_and_set_endio(bio
, &m
->saved_bi_end_io
, overwrite_endio
);
1215 inc_all_io_entry(pool
, bio
);
1216 remap_and_issue(tc
, bio
, data_begin
);
1220 * A partial copy also needs to zero the uncopied region.
1222 static void schedule_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1223 struct dm_dev
*origin
, dm_block_t data_origin
,
1224 dm_block_t data_dest
,
1225 struct dm_bio_prison_cell
*cell
, struct bio
*bio
,
1229 struct pool
*pool
= tc
->pool
;
1230 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1233 m
->virt_begin
= virt_block
;
1234 m
->virt_end
= virt_block
+ 1u;
1235 m
->data_block
= data_dest
;
1239 * quiesce action + copy action + an extra reference held for the
1240 * duration of this function (we may need to inc later for a
1243 atomic_set(&m
->prepare_actions
, 3);
1245 if (!dm_deferred_set_add_work(pool
->shared_read_ds
, &m
->list
))
1246 complete_mapping_preparation(m
); /* already quiesced */
1249 * IO to pool_dev remaps to the pool target's data_dev.
1251 * If the whole block of data is being overwritten, we can issue the
1252 * bio immediately. Otherwise we use kcopyd to clone the data first.
1254 if (io_overwrites_block(pool
, bio
))
1255 remap_and_issue_overwrite(tc
, bio
, data_dest
, m
);
1257 struct dm_io_region from
, to
;
1259 from
.bdev
= origin
->bdev
;
1260 from
.sector
= data_origin
* pool
->sectors_per_block
;
1263 to
.bdev
= tc
->pool_dev
->bdev
;
1264 to
.sector
= data_dest
* pool
->sectors_per_block
;
1267 r
= dm_kcopyd_copy(pool
->copier
, &from
, 1, &to
,
1268 0, copy_complete
, m
);
1270 DMERR_LIMIT("dm_kcopyd_copy() failed");
1271 copy_complete(1, 1, m
);
1274 * We allow the zero to be issued, to simplify the
1275 * error path. Otherwise we'd need to start
1276 * worrying about decrementing the prepare_actions
1282 * Do we need to zero a tail region?
1284 if (len
< pool
->sectors_per_block
&& pool
->pf
.zero_new_blocks
) {
1285 atomic_inc(&m
->prepare_actions
);
1287 data_dest
* pool
->sectors_per_block
+ len
,
1288 (data_dest
+ 1) * pool
->sectors_per_block
);
1292 complete_mapping_preparation(m
); /* drop our ref */
1295 static void schedule_internal_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1296 dm_block_t data_origin
, dm_block_t data_dest
,
1297 struct dm_bio_prison_cell
*cell
, struct bio
*bio
)
1299 schedule_copy(tc
, virt_block
, tc
->pool_dev
,
1300 data_origin
, data_dest
, cell
, bio
,
1301 tc
->pool
->sectors_per_block
);
1304 static void schedule_zero(struct thin_c
*tc
, dm_block_t virt_block
,
1305 dm_block_t data_block
, struct dm_bio_prison_cell
*cell
,
1308 struct pool
*pool
= tc
->pool
;
1309 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1311 atomic_set(&m
->prepare_actions
, 1); /* no need to quiesce */
1313 m
->virt_begin
= virt_block
;
1314 m
->virt_end
= virt_block
+ 1u;
1315 m
->data_block
= data_block
;
1319 * If the whole block of data is being overwritten or we are not
1320 * zeroing pre-existing data, we can issue the bio immediately.
1321 * Otherwise we use kcopyd to zero the data first.
1323 if (pool
->pf
.zero_new_blocks
) {
1324 if (io_overwrites_block(pool
, bio
))
1325 remap_and_issue_overwrite(tc
, bio
, data_block
, m
);
1327 ll_zero(tc
, m
, data_block
* pool
->sectors_per_block
,
1328 (data_block
+ 1) * pool
->sectors_per_block
);
1330 process_prepared_mapping(m
);
1333 static void schedule_external_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1334 dm_block_t data_dest
,
1335 struct dm_bio_prison_cell
*cell
, struct bio
*bio
)
1337 struct pool
*pool
= tc
->pool
;
1338 sector_t virt_block_begin
= virt_block
* pool
->sectors_per_block
;
1339 sector_t virt_block_end
= (virt_block
+ 1) * pool
->sectors_per_block
;
1341 if (virt_block_end
<= tc
->origin_size
)
1342 schedule_copy(tc
, virt_block
, tc
->origin_dev
,
1343 virt_block
, data_dest
, cell
, bio
,
1344 pool
->sectors_per_block
);
1346 else if (virt_block_begin
< tc
->origin_size
)
1347 schedule_copy(tc
, virt_block
, tc
->origin_dev
,
1348 virt_block
, data_dest
, cell
, bio
,
1349 tc
->origin_size
- virt_block_begin
);
1352 schedule_zero(tc
, virt_block
, data_dest
, cell
, bio
);
1355 static void set_pool_mode(struct pool
*pool
, enum pool_mode new_mode
);
1357 static void check_for_space(struct pool
*pool
)
1362 if (get_pool_mode(pool
) != PM_OUT_OF_DATA_SPACE
)
1365 r
= dm_pool_get_free_block_count(pool
->pmd
, &nr_free
);
1370 set_pool_mode(pool
, PM_WRITE
);
1374 * A non-zero return indicates read_only or fail_io mode.
1375 * Many callers don't care about the return value.
1377 static int commit(struct pool
*pool
)
1381 if (get_pool_mode(pool
) >= PM_READ_ONLY
)
1384 r
= dm_pool_commit_metadata(pool
->pmd
);
1386 metadata_operation_failed(pool
, "dm_pool_commit_metadata", r
);
1388 check_for_space(pool
);
1393 static void check_low_water_mark(struct pool
*pool
, dm_block_t free_blocks
)
1395 unsigned long flags
;
1397 if (free_blocks
<= pool
->low_water_blocks
&& !pool
->low_water_triggered
) {
1398 DMWARN("%s: reached low water mark for data device: sending event.",
1399 dm_device_name(pool
->pool_md
));
1400 spin_lock_irqsave(&pool
->lock
, flags
);
1401 pool
->low_water_triggered
= true;
1402 spin_unlock_irqrestore(&pool
->lock
, flags
);
1403 dm_table_event(pool
->ti
->table
);
1407 static int alloc_data_block(struct thin_c
*tc
, dm_block_t
*result
)
1410 dm_block_t free_blocks
;
1411 struct pool
*pool
= tc
->pool
;
1413 if (WARN_ON(get_pool_mode(pool
) != PM_WRITE
))
1416 r
= dm_pool_get_free_block_count(pool
->pmd
, &free_blocks
);
1418 metadata_operation_failed(pool
, "dm_pool_get_free_block_count", r
);
1422 check_low_water_mark(pool
, free_blocks
);
1426 * Try to commit to see if that will free up some
1433 r
= dm_pool_get_free_block_count(pool
->pmd
, &free_blocks
);
1435 metadata_operation_failed(pool
, "dm_pool_get_free_block_count", r
);
1440 set_pool_mode(pool
, PM_OUT_OF_DATA_SPACE
);
1445 r
= dm_pool_alloc_data_block(pool
->pmd
, result
);
1447 metadata_operation_failed(pool
, "dm_pool_alloc_data_block", r
);
1455 * If we have run out of space, queue bios until the device is
1456 * resumed, presumably after having been reloaded with more space.
1458 static void retry_on_resume(struct bio
*bio
)
1460 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1461 struct thin_c
*tc
= h
->tc
;
1462 unsigned long flags
;
1464 spin_lock_irqsave(&tc
->lock
, flags
);
1465 bio_list_add(&tc
->retry_on_resume_list
, bio
);
1466 spin_unlock_irqrestore(&tc
->lock
, flags
);
1469 static int should_error_unserviceable_bio(struct pool
*pool
)
1471 enum pool_mode m
= get_pool_mode(pool
);
1475 /* Shouldn't get here */
1476 DMERR_LIMIT("bio unserviceable, yet pool is in PM_WRITE mode");
1479 case PM_OUT_OF_DATA_SPACE
:
1480 return pool
->pf
.error_if_no_space
? -ENOSPC
: 0;
1486 /* Shouldn't get here */
1487 DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode");
1492 static void handle_unserviceable_bio(struct pool
*pool
, struct bio
*bio
)
1494 int error
= should_error_unserviceable_bio(pool
);
1497 bio_endio(bio
, error
);
1499 retry_on_resume(bio
);
1502 static void retry_bios_on_resume(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
1505 struct bio_list bios
;
1508 error
= should_error_unserviceable_bio(pool
);
1510 cell_error_with_code(pool
, cell
, error
);
1514 bio_list_init(&bios
);
1515 cell_release(pool
, cell
, &bios
);
1517 while ((bio
= bio_list_pop(&bios
)))
1518 retry_on_resume(bio
);
1521 static void process_discard_cell_no_passdown(struct thin_c
*tc
,
1522 struct dm_bio_prison_cell
*virt_cell
)
1524 struct pool
*pool
= tc
->pool
;
1525 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1528 * We don't need to lock the data blocks, since there's no
1529 * passdown. We only lock data blocks for allocation and breaking sharing.
1532 m
->virt_begin
= virt_cell
->key
.block_begin
;
1533 m
->virt_end
= virt_cell
->key
.block_end
;
1534 m
->cell
= virt_cell
;
1535 m
->bio
= virt_cell
->holder
;
1537 if (!dm_deferred_set_add_work(pool
->all_io_ds
, &m
->list
))
1538 pool
->process_prepared_discard(m
);
1542 * FIXME: DM local hack to defer parent bios's end_io until we
1543 * _know_ all chained sub range discard bios have completed.
1544 * Will go away once late bio splitting lands upstream!
1546 static inline void __bio_inc_remaining(struct bio
*bio
)
1548 bio
->bi_flags
|= (1 << BIO_CHAIN
);
1549 smp_mb__before_atomic();
1550 atomic_inc(&bio
->__bi_remaining
);
1553 static void break_up_discard_bio(struct thin_c
*tc
, dm_block_t begin
, dm_block_t end
,
1556 struct pool
*pool
= tc
->pool
;
1560 struct dm_cell_key data_key
;
1561 struct dm_bio_prison_cell
*data_cell
;
1562 struct dm_thin_new_mapping
*m
;
1563 dm_block_t virt_begin
, virt_end
, data_begin
;
1565 while (begin
!= end
) {
1566 r
= ensure_next_mapping(pool
);
1568 /* we did our best */
1571 r
= dm_thin_find_mapped_range(tc
->td
, begin
, end
, &virt_begin
, &virt_end
,
1572 &data_begin
, &maybe_shared
);
1575 * Silently fail, letting any mappings we've
1580 build_key(tc
->td
, PHYSICAL
, data_begin
, data_begin
+ (virt_end
- virt_begin
), &data_key
);
1581 if (bio_detain(tc
->pool
, &data_key
, NULL
, &data_cell
)) {
1582 /* contention, we'll give up with this range */
1588 * IO may still be going to the destination block. We must
1589 * quiesce before we can do the removal.
1591 m
= get_next_mapping(pool
);
1593 m
->maybe_shared
= maybe_shared
;
1594 m
->virt_begin
= virt_begin
;
1595 m
->virt_end
= virt_end
;
1596 m
->data_block
= data_begin
;
1597 m
->cell
= data_cell
;
1601 * The parent bio must not complete before sub discard bios are
1602 * chained to it (see __blkdev_issue_discard_async's bio_chain)!
1604 * This per-mapping bi_remaining increment is paired with
1605 * the implicit decrement that occurs via bio_endio() in
1606 * process_prepared_discard_{passdown,no_passdown}.
1608 __bio_inc_remaining(bio
);
1609 if (!dm_deferred_set_add_work(pool
->all_io_ds
, &m
->list
))
1610 pool
->process_prepared_discard(m
);
1616 static void process_discard_cell_passdown(struct thin_c
*tc
, struct dm_bio_prison_cell
*virt_cell
)
1618 struct bio
*bio
= virt_cell
->holder
;
1619 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1622 * The virt_cell will only get freed once the origin bio completes.
1623 * This means it will remain locked while all the individual
1624 * passdown bios are in flight.
1626 h
->cell
= virt_cell
;
1627 break_up_discard_bio(tc
, virt_cell
->key
.block_begin
, virt_cell
->key
.block_end
, bio
);
1630 * We complete the bio now, knowing that the bi_remaining field
1631 * will prevent completion until the sub range discards have
1637 static void process_discard_bio(struct thin_c
*tc
, struct bio
*bio
)
1639 dm_block_t begin
, end
;
1640 struct dm_cell_key virt_key
;
1641 struct dm_bio_prison_cell
*virt_cell
;
1643 get_bio_block_range(tc
, bio
, &begin
, &end
);
1646 * The discard covers less than a block.
1652 build_key(tc
->td
, VIRTUAL
, begin
, end
, &virt_key
);
1653 if (bio_detain(tc
->pool
, &virt_key
, bio
, &virt_cell
))
1655 * Potential starvation issue: We're relying on the
1656 * fs/application being well behaved, and not trying to
1657 * send IO to a region at the same time as discarding it.
1658 * If they do this persistently then it's possible this
1659 * cell will never be granted.
1663 tc
->pool
->process_discard_cell(tc
, virt_cell
);
1666 static void break_sharing(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
,
1667 struct dm_cell_key
*key
,
1668 struct dm_thin_lookup_result
*lookup_result
,
1669 struct dm_bio_prison_cell
*cell
)
1672 dm_block_t data_block
;
1673 struct pool
*pool
= tc
->pool
;
1675 r
= alloc_data_block(tc
, &data_block
);
1678 schedule_internal_copy(tc
, block
, lookup_result
->block
,
1679 data_block
, cell
, bio
);
1683 retry_bios_on_resume(pool
, cell
);
1687 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1689 cell_error(pool
, cell
);
1694 static void __remap_and_issue_shared_cell(void *context
,
1695 struct dm_bio_prison_cell
*cell
)
1697 struct remap_info
*info
= context
;
1700 while ((bio
= bio_list_pop(&cell
->bios
))) {
1701 if ((bio_data_dir(bio
) == WRITE
) ||
1702 (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
)))
1703 bio_list_add(&info
->defer_bios
, bio
);
1705 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));;
1707 h
->shared_read_entry
= dm_deferred_entry_inc(info
->tc
->pool
->shared_read_ds
);
1708 inc_all_io_entry(info
->tc
->pool
, bio
);
1709 bio_list_add(&info
->issue_bios
, bio
);
1714 static void remap_and_issue_shared_cell(struct thin_c
*tc
,
1715 struct dm_bio_prison_cell
*cell
,
1719 struct remap_info info
;
1722 bio_list_init(&info
.defer_bios
);
1723 bio_list_init(&info
.issue_bios
);
1725 cell_visit_release(tc
->pool
, __remap_and_issue_shared_cell
,
1728 while ((bio
= bio_list_pop(&info
.defer_bios
)))
1729 thin_defer_bio(tc
, bio
);
1731 while ((bio
= bio_list_pop(&info
.issue_bios
)))
1732 remap_and_issue(tc
, bio
, block
);
1735 static void process_shared_bio(struct thin_c
*tc
, struct bio
*bio
,
1737 struct dm_thin_lookup_result
*lookup_result
,
1738 struct dm_bio_prison_cell
*virt_cell
)
1740 struct dm_bio_prison_cell
*data_cell
;
1741 struct pool
*pool
= tc
->pool
;
1742 struct dm_cell_key key
;
1745 * If cell is already occupied, then sharing is already in the process
1746 * of being broken so we have nothing further to do here.
1748 build_data_key(tc
->td
, lookup_result
->block
, &key
);
1749 if (bio_detain(pool
, &key
, bio
, &data_cell
)) {
1750 cell_defer_no_holder(tc
, virt_cell
);
1754 if (bio_data_dir(bio
) == WRITE
&& bio
->bi_iter
.bi_size
) {
1755 break_sharing(tc
, bio
, block
, &key
, lookup_result
, data_cell
);
1756 cell_defer_no_holder(tc
, virt_cell
);
1758 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1760 h
->shared_read_entry
= dm_deferred_entry_inc(pool
->shared_read_ds
);
1761 inc_all_io_entry(pool
, bio
);
1762 remap_and_issue(tc
, bio
, lookup_result
->block
);
1764 remap_and_issue_shared_cell(tc
, data_cell
, lookup_result
->block
);
1765 remap_and_issue_shared_cell(tc
, virt_cell
, lookup_result
->block
);
1769 static void provision_block(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
,
1770 struct dm_bio_prison_cell
*cell
)
1773 dm_block_t data_block
;
1774 struct pool
*pool
= tc
->pool
;
1777 * Remap empty bios (flushes) immediately, without provisioning.
1779 if (!bio
->bi_iter
.bi_size
) {
1780 inc_all_io_entry(pool
, bio
);
1781 cell_defer_no_holder(tc
, cell
);
1783 remap_and_issue(tc
, bio
, 0);
1788 * Fill read bios with zeroes and complete them immediately.
1790 if (bio_data_dir(bio
) == READ
) {
1792 cell_defer_no_holder(tc
, cell
);
1797 r
= alloc_data_block(tc
, &data_block
);
1801 schedule_external_copy(tc
, block
, data_block
, cell
, bio
);
1803 schedule_zero(tc
, block
, data_block
, cell
, bio
);
1807 retry_bios_on_resume(pool
, cell
);
1811 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1813 cell_error(pool
, cell
);
1818 static void process_cell(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1821 struct pool
*pool
= tc
->pool
;
1822 struct bio
*bio
= cell
->holder
;
1823 dm_block_t block
= get_bio_block(tc
, bio
);
1824 struct dm_thin_lookup_result lookup_result
;
1826 if (tc
->requeue_mode
) {
1827 cell_requeue(pool
, cell
);
1831 r
= dm_thin_find_block(tc
->td
, block
, 1, &lookup_result
);
1834 if (lookup_result
.shared
)
1835 process_shared_bio(tc
, bio
, block
, &lookup_result
, cell
);
1837 inc_all_io_entry(pool
, bio
);
1838 remap_and_issue(tc
, bio
, lookup_result
.block
);
1839 inc_remap_and_issue_cell(tc
, cell
, lookup_result
.block
);
1844 if (bio_data_dir(bio
) == READ
&& tc
->origin_dev
) {
1845 inc_all_io_entry(pool
, bio
);
1846 cell_defer_no_holder(tc
, cell
);
1848 if (bio_end_sector(bio
) <= tc
->origin_size
)
1849 remap_to_origin_and_issue(tc
, bio
);
1851 else if (bio
->bi_iter
.bi_sector
< tc
->origin_size
) {
1853 bio
->bi_iter
.bi_size
= (tc
->origin_size
- bio
->bi_iter
.bi_sector
) << SECTOR_SHIFT
;
1854 remap_to_origin_and_issue(tc
, bio
);
1861 provision_block(tc
, bio
, block
, cell
);
1865 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1867 cell_defer_no_holder(tc
, cell
);
1873 static void process_bio(struct thin_c
*tc
, struct bio
*bio
)
1875 struct pool
*pool
= tc
->pool
;
1876 dm_block_t block
= get_bio_block(tc
, bio
);
1877 struct dm_bio_prison_cell
*cell
;
1878 struct dm_cell_key key
;
1881 * If cell is already occupied, then the block is already
1882 * being provisioned so we have nothing further to do here.
1884 build_virtual_key(tc
->td
, block
, &key
);
1885 if (bio_detain(pool
, &key
, bio
, &cell
))
1888 process_cell(tc
, cell
);
1891 static void __process_bio_read_only(struct thin_c
*tc
, struct bio
*bio
,
1892 struct dm_bio_prison_cell
*cell
)
1895 int rw
= bio_data_dir(bio
);
1896 dm_block_t block
= get_bio_block(tc
, bio
);
1897 struct dm_thin_lookup_result lookup_result
;
1899 r
= dm_thin_find_block(tc
->td
, block
, 1, &lookup_result
);
1902 if (lookup_result
.shared
&& (rw
== WRITE
) && bio
->bi_iter
.bi_size
) {
1903 handle_unserviceable_bio(tc
->pool
, bio
);
1905 cell_defer_no_holder(tc
, cell
);
1907 inc_all_io_entry(tc
->pool
, bio
);
1908 remap_and_issue(tc
, bio
, lookup_result
.block
);
1910 inc_remap_and_issue_cell(tc
, cell
, lookup_result
.block
);
1916 cell_defer_no_holder(tc
, cell
);
1918 handle_unserviceable_bio(tc
->pool
, bio
);
1922 if (tc
->origin_dev
) {
1923 inc_all_io_entry(tc
->pool
, bio
);
1924 remap_to_origin_and_issue(tc
, bio
);
1933 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1936 cell_defer_no_holder(tc
, cell
);
1942 static void process_bio_read_only(struct thin_c
*tc
, struct bio
*bio
)
1944 __process_bio_read_only(tc
, bio
, NULL
);
1947 static void process_cell_read_only(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1949 __process_bio_read_only(tc
, cell
->holder
, cell
);
1952 static void process_bio_success(struct thin_c
*tc
, struct bio
*bio
)
1957 static void process_bio_fail(struct thin_c
*tc
, struct bio
*bio
)
1962 static void process_cell_success(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1964 cell_success(tc
->pool
, cell
);
1967 static void process_cell_fail(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1969 cell_error(tc
->pool
, cell
);
1973 * FIXME: should we also commit due to size of transaction, measured in
1976 static int need_commit_due_to_time(struct pool
*pool
)
1978 return !time_in_range(jiffies
, pool
->last_commit_jiffies
,
1979 pool
->last_commit_jiffies
+ COMMIT_PERIOD
);
1982 #define thin_pbd(node) rb_entry((node), struct dm_thin_endio_hook, rb_node)
1983 #define thin_bio(pbd) dm_bio_from_per_bio_data((pbd), sizeof(struct dm_thin_endio_hook))
1985 static void __thin_bio_rb_add(struct thin_c
*tc
, struct bio
*bio
)
1987 struct rb_node
**rbp
, *parent
;
1988 struct dm_thin_endio_hook
*pbd
;
1989 sector_t bi_sector
= bio
->bi_iter
.bi_sector
;
1991 rbp
= &tc
->sort_bio_list
.rb_node
;
1995 pbd
= thin_pbd(parent
);
1997 if (bi_sector
< thin_bio(pbd
)->bi_iter
.bi_sector
)
1998 rbp
= &(*rbp
)->rb_left
;
2000 rbp
= &(*rbp
)->rb_right
;
2003 pbd
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
2004 rb_link_node(&pbd
->rb_node
, parent
, rbp
);
2005 rb_insert_color(&pbd
->rb_node
, &tc
->sort_bio_list
);
2008 static void __extract_sorted_bios(struct thin_c
*tc
)
2010 struct rb_node
*node
;
2011 struct dm_thin_endio_hook
*pbd
;
2014 for (node
= rb_first(&tc
->sort_bio_list
); node
; node
= rb_next(node
)) {
2015 pbd
= thin_pbd(node
);
2016 bio
= thin_bio(pbd
);
2018 bio_list_add(&tc
->deferred_bio_list
, bio
);
2019 rb_erase(&pbd
->rb_node
, &tc
->sort_bio_list
);
2022 WARN_ON(!RB_EMPTY_ROOT(&tc
->sort_bio_list
));
2025 static void __sort_thin_deferred_bios(struct thin_c
*tc
)
2028 struct bio_list bios
;
2030 bio_list_init(&bios
);
2031 bio_list_merge(&bios
, &tc
->deferred_bio_list
);
2032 bio_list_init(&tc
->deferred_bio_list
);
2034 /* Sort deferred_bio_list using rb-tree */
2035 while ((bio
= bio_list_pop(&bios
)))
2036 __thin_bio_rb_add(tc
, bio
);
2039 * Transfer the sorted bios in sort_bio_list back to
2040 * deferred_bio_list to allow lockless submission of
2043 __extract_sorted_bios(tc
);
2046 static void process_thin_deferred_bios(struct thin_c
*tc
)
2048 struct pool
*pool
= tc
->pool
;
2049 unsigned long flags
;
2051 struct bio_list bios
;
2052 struct blk_plug plug
;
2055 if (tc
->requeue_mode
) {
2056 error_thin_bio_list(tc
, &tc
->deferred_bio_list
, DM_ENDIO_REQUEUE
);
2060 bio_list_init(&bios
);
2062 spin_lock_irqsave(&tc
->lock
, flags
);
2064 if (bio_list_empty(&tc
->deferred_bio_list
)) {
2065 spin_unlock_irqrestore(&tc
->lock
, flags
);
2069 __sort_thin_deferred_bios(tc
);
2071 bio_list_merge(&bios
, &tc
->deferred_bio_list
);
2072 bio_list_init(&tc
->deferred_bio_list
);
2074 spin_unlock_irqrestore(&tc
->lock
, flags
);
2076 blk_start_plug(&plug
);
2077 while ((bio
= bio_list_pop(&bios
))) {
2079 * If we've got no free new_mapping structs, and processing
2080 * this bio might require one, we pause until there are some
2081 * prepared mappings to process.
2083 if (ensure_next_mapping(pool
)) {
2084 spin_lock_irqsave(&tc
->lock
, flags
);
2085 bio_list_add(&tc
->deferred_bio_list
, bio
);
2086 bio_list_merge(&tc
->deferred_bio_list
, &bios
);
2087 spin_unlock_irqrestore(&tc
->lock
, flags
);
2091 if (bio
->bi_rw
& REQ_DISCARD
)
2092 pool
->process_discard(tc
, bio
);
2094 pool
->process_bio(tc
, bio
);
2096 if ((count
++ & 127) == 0) {
2097 throttle_work_update(&pool
->throttle
);
2098 dm_pool_issue_prefetches(pool
->pmd
);
2101 blk_finish_plug(&plug
);
2104 static int cmp_cells(const void *lhs
, const void *rhs
)
2106 struct dm_bio_prison_cell
*lhs_cell
= *((struct dm_bio_prison_cell
**) lhs
);
2107 struct dm_bio_prison_cell
*rhs_cell
= *((struct dm_bio_prison_cell
**) rhs
);
2109 BUG_ON(!lhs_cell
->holder
);
2110 BUG_ON(!rhs_cell
->holder
);
2112 if (lhs_cell
->holder
->bi_iter
.bi_sector
< rhs_cell
->holder
->bi_iter
.bi_sector
)
2115 if (lhs_cell
->holder
->bi_iter
.bi_sector
> rhs_cell
->holder
->bi_iter
.bi_sector
)
2121 static unsigned sort_cells(struct pool
*pool
, struct list_head
*cells
)
2124 struct dm_bio_prison_cell
*cell
, *tmp
;
2126 list_for_each_entry_safe(cell
, tmp
, cells
, user_list
) {
2127 if (count
>= CELL_SORT_ARRAY_SIZE
)
2130 pool
->cell_sort_array
[count
++] = cell
;
2131 list_del(&cell
->user_list
);
2134 sort(pool
->cell_sort_array
, count
, sizeof(cell
), cmp_cells
, NULL
);
2139 static void process_thin_deferred_cells(struct thin_c
*tc
)
2141 struct pool
*pool
= tc
->pool
;
2142 unsigned long flags
;
2143 struct list_head cells
;
2144 struct dm_bio_prison_cell
*cell
;
2145 unsigned i
, j
, count
;
2147 INIT_LIST_HEAD(&cells
);
2149 spin_lock_irqsave(&tc
->lock
, flags
);
2150 list_splice_init(&tc
->deferred_cells
, &cells
);
2151 spin_unlock_irqrestore(&tc
->lock
, flags
);
2153 if (list_empty(&cells
))
2157 count
= sort_cells(tc
->pool
, &cells
);
2159 for (i
= 0; i
< count
; i
++) {
2160 cell
= pool
->cell_sort_array
[i
];
2161 BUG_ON(!cell
->holder
);
2164 * If we've got no free new_mapping structs, and processing
2165 * this bio might require one, we pause until there are some
2166 * prepared mappings to process.
2168 if (ensure_next_mapping(pool
)) {
2169 for (j
= i
; j
< count
; j
++)
2170 list_add(&pool
->cell_sort_array
[j
]->user_list
, &cells
);
2172 spin_lock_irqsave(&tc
->lock
, flags
);
2173 list_splice(&cells
, &tc
->deferred_cells
);
2174 spin_unlock_irqrestore(&tc
->lock
, flags
);
2178 if (cell
->holder
->bi_rw
& REQ_DISCARD
)
2179 pool
->process_discard_cell(tc
, cell
);
2181 pool
->process_cell(tc
, cell
);
2183 } while (!list_empty(&cells
));
2186 static void thin_get(struct thin_c
*tc
);
2187 static void thin_put(struct thin_c
*tc
);
2190 * We can't hold rcu_read_lock() around code that can block. So we
2191 * find a thin with the rcu lock held; bump a refcount; then drop
2194 static struct thin_c
*get_first_thin(struct pool
*pool
)
2196 struct thin_c
*tc
= NULL
;
2199 if (!list_empty(&pool
->active_thins
)) {
2200 tc
= list_entry_rcu(pool
->active_thins
.next
, struct thin_c
, list
);
2208 static struct thin_c
*get_next_thin(struct pool
*pool
, struct thin_c
*tc
)
2210 struct thin_c
*old_tc
= tc
;
2213 list_for_each_entry_continue_rcu(tc
, &pool
->active_thins
, list
) {
2225 static void process_deferred_bios(struct pool
*pool
)
2227 unsigned long flags
;
2229 struct bio_list bios
;
2232 tc
= get_first_thin(pool
);
2234 process_thin_deferred_cells(tc
);
2235 process_thin_deferred_bios(tc
);
2236 tc
= get_next_thin(pool
, tc
);
2240 * If there are any deferred flush bios, we must commit
2241 * the metadata before issuing them.
2243 bio_list_init(&bios
);
2244 spin_lock_irqsave(&pool
->lock
, flags
);
2245 bio_list_merge(&bios
, &pool
->deferred_flush_bios
);
2246 bio_list_init(&pool
->deferred_flush_bios
);
2247 spin_unlock_irqrestore(&pool
->lock
, flags
);
2249 if (bio_list_empty(&bios
) &&
2250 !(dm_pool_changed_this_transaction(pool
->pmd
) && need_commit_due_to_time(pool
)))
2254 while ((bio
= bio_list_pop(&bios
)))
2258 pool
->last_commit_jiffies
= jiffies
;
2260 while ((bio
= bio_list_pop(&bios
)))
2261 generic_make_request(bio
);
2264 static void do_worker(struct work_struct
*ws
)
2266 struct pool
*pool
= container_of(ws
, struct pool
, worker
);
2268 throttle_work_start(&pool
->throttle
);
2269 dm_pool_issue_prefetches(pool
->pmd
);
2270 throttle_work_update(&pool
->throttle
);
2271 process_prepared(pool
, &pool
->prepared_mappings
, &pool
->process_prepared_mapping
);
2272 throttle_work_update(&pool
->throttle
);
2273 process_prepared(pool
, &pool
->prepared_discards
, &pool
->process_prepared_discard
);
2274 throttle_work_update(&pool
->throttle
);
2275 process_deferred_bios(pool
);
2276 throttle_work_complete(&pool
->throttle
);
2280 * We want to commit periodically so that not too much
2281 * unwritten data builds up.
2283 static void do_waker(struct work_struct
*ws
)
2285 struct pool
*pool
= container_of(to_delayed_work(ws
), struct pool
, waker
);
2287 queue_delayed_work(pool
->wq
, &pool
->waker
, COMMIT_PERIOD
);
2290 static void notify_of_pool_mode_change_to_oods(struct pool
*pool
);
2293 * We're holding onto IO to allow userland time to react. After the
2294 * timeout either the pool will have been resized (and thus back in
2295 * PM_WRITE mode), or we degrade to PM_OUT_OF_DATA_SPACE w/ error_if_no_space.
2297 static void do_no_space_timeout(struct work_struct
*ws
)
2299 struct pool
*pool
= container_of(to_delayed_work(ws
), struct pool
,
2302 if (get_pool_mode(pool
) == PM_OUT_OF_DATA_SPACE
&& !pool
->pf
.error_if_no_space
) {
2303 pool
->pf
.error_if_no_space
= true;
2304 notify_of_pool_mode_change_to_oods(pool
);
2305 error_retry_list_with_code(pool
, -ENOSPC
);
2309 /*----------------------------------------------------------------*/
2312 struct work_struct worker
;
2313 struct completion complete
;
2316 static struct pool_work
*to_pool_work(struct work_struct
*ws
)
2318 return container_of(ws
, struct pool_work
, worker
);
2321 static void pool_work_complete(struct pool_work
*pw
)
2323 complete(&pw
->complete
);
2326 static void pool_work_wait(struct pool_work
*pw
, struct pool
*pool
,
2327 void (*fn
)(struct work_struct
*))
2329 INIT_WORK_ONSTACK(&pw
->worker
, fn
);
2330 init_completion(&pw
->complete
);
2331 queue_work(pool
->wq
, &pw
->worker
);
2332 wait_for_completion(&pw
->complete
);
2335 /*----------------------------------------------------------------*/
2337 struct noflush_work
{
2338 struct pool_work pw
;
2342 static struct noflush_work
*to_noflush(struct work_struct
*ws
)
2344 return container_of(to_pool_work(ws
), struct noflush_work
, pw
);
2347 static void do_noflush_start(struct work_struct
*ws
)
2349 struct noflush_work
*w
= to_noflush(ws
);
2350 w
->tc
->requeue_mode
= true;
2352 pool_work_complete(&w
->pw
);
2355 static void do_noflush_stop(struct work_struct
*ws
)
2357 struct noflush_work
*w
= to_noflush(ws
);
2358 w
->tc
->requeue_mode
= false;
2359 pool_work_complete(&w
->pw
);
2362 static void noflush_work(struct thin_c
*tc
, void (*fn
)(struct work_struct
*))
2364 struct noflush_work w
;
2367 pool_work_wait(&w
.pw
, tc
->pool
, fn
);
2370 /*----------------------------------------------------------------*/
2372 static enum pool_mode
get_pool_mode(struct pool
*pool
)
2374 return pool
->pf
.mode
;
2377 static void notify_of_pool_mode_change(struct pool
*pool
, const char *new_mode
)
2379 dm_table_event(pool
->ti
->table
);
2380 DMINFO("%s: switching pool to %s mode",
2381 dm_device_name(pool
->pool_md
), new_mode
);
2384 static void notify_of_pool_mode_change_to_oods(struct pool
*pool
)
2386 if (!pool
->pf
.error_if_no_space
)
2387 notify_of_pool_mode_change(pool
, "out-of-data-space (queue IO)");
2389 notify_of_pool_mode_change(pool
, "out-of-data-space (error IO)");
2392 static bool passdown_enabled(struct pool_c
*pt
)
2394 return pt
->adjusted_pf
.discard_passdown
;
2397 static void set_discard_callbacks(struct pool
*pool
)
2399 struct pool_c
*pt
= pool
->ti
->private;
2401 if (passdown_enabled(pt
)) {
2402 pool
->process_discard_cell
= process_discard_cell_passdown
;
2403 pool
->process_prepared_discard
= process_prepared_discard_passdown
;
2405 pool
->process_discard_cell
= process_discard_cell_no_passdown
;
2406 pool
->process_prepared_discard
= process_prepared_discard_no_passdown
;
2410 static void set_pool_mode(struct pool
*pool
, enum pool_mode new_mode
)
2412 struct pool_c
*pt
= pool
->ti
->private;
2413 bool needs_check
= dm_pool_metadata_needs_check(pool
->pmd
);
2414 enum pool_mode old_mode
= get_pool_mode(pool
);
2415 unsigned long no_space_timeout
= ACCESS_ONCE(no_space_timeout_secs
) * HZ
;
2418 * Never allow the pool to transition to PM_WRITE mode if user
2419 * intervention is required to verify metadata and data consistency.
2421 if (new_mode
== PM_WRITE
&& needs_check
) {
2422 DMERR("%s: unable to switch pool to write mode until repaired.",
2423 dm_device_name(pool
->pool_md
));
2424 if (old_mode
!= new_mode
)
2425 new_mode
= old_mode
;
2427 new_mode
= PM_READ_ONLY
;
2430 * If we were in PM_FAIL mode, rollback of metadata failed. We're
2431 * not going to recover without a thin_repair. So we never let the
2432 * pool move out of the old mode.
2434 if (old_mode
== PM_FAIL
)
2435 new_mode
= old_mode
;
2439 if (old_mode
!= new_mode
)
2440 notify_of_pool_mode_change(pool
, "failure");
2441 dm_pool_metadata_read_only(pool
->pmd
);
2442 pool
->process_bio
= process_bio_fail
;
2443 pool
->process_discard
= process_bio_fail
;
2444 pool
->process_cell
= process_cell_fail
;
2445 pool
->process_discard_cell
= process_cell_fail
;
2446 pool
->process_prepared_mapping
= process_prepared_mapping_fail
;
2447 pool
->process_prepared_discard
= process_prepared_discard_fail
;
2449 error_retry_list(pool
);
2453 if (old_mode
!= new_mode
)
2454 notify_of_pool_mode_change(pool
, "read-only");
2455 dm_pool_metadata_read_only(pool
->pmd
);
2456 pool
->process_bio
= process_bio_read_only
;
2457 pool
->process_discard
= process_bio_success
;
2458 pool
->process_cell
= process_cell_read_only
;
2459 pool
->process_discard_cell
= process_cell_success
;
2460 pool
->process_prepared_mapping
= process_prepared_mapping_fail
;
2461 pool
->process_prepared_discard
= process_prepared_discard_success
;
2463 error_retry_list(pool
);
2466 case PM_OUT_OF_DATA_SPACE
:
2468 * Ideally we'd never hit this state; the low water mark
2469 * would trigger userland to extend the pool before we
2470 * completely run out of data space. However, many small
2471 * IOs to unprovisioned space can consume data space at an
2472 * alarming rate. Adjust your low water mark if you're
2473 * frequently seeing this mode.
2475 if (old_mode
!= new_mode
)
2476 notify_of_pool_mode_change_to_oods(pool
);
2477 pool
->process_bio
= process_bio_read_only
;
2478 pool
->process_discard
= process_discard_bio
;
2479 pool
->process_cell
= process_cell_read_only
;
2480 pool
->process_prepared_mapping
= process_prepared_mapping
;
2481 set_discard_callbacks(pool
);
2483 if (!pool
->pf
.error_if_no_space
&& no_space_timeout
)
2484 queue_delayed_work(pool
->wq
, &pool
->no_space_timeout
, no_space_timeout
);
2488 if (old_mode
!= new_mode
)
2489 notify_of_pool_mode_change(pool
, "write");
2490 dm_pool_metadata_read_write(pool
->pmd
);
2491 pool
->process_bio
= process_bio
;
2492 pool
->process_discard
= process_discard_bio
;
2493 pool
->process_cell
= process_cell
;
2494 pool
->process_prepared_mapping
= process_prepared_mapping
;
2495 set_discard_callbacks(pool
);
2499 pool
->pf
.mode
= new_mode
;
2501 * The pool mode may have changed, sync it so bind_control_target()
2502 * doesn't cause an unexpected mode transition on resume.
2504 pt
->adjusted_pf
.mode
= new_mode
;
2507 static void abort_transaction(struct pool
*pool
)
2509 const char *dev_name
= dm_device_name(pool
->pool_md
);
2511 DMERR_LIMIT("%s: aborting current metadata transaction", dev_name
);
2512 if (dm_pool_abort_metadata(pool
->pmd
)) {
2513 DMERR("%s: failed to abort metadata transaction", dev_name
);
2514 set_pool_mode(pool
, PM_FAIL
);
2517 if (dm_pool_metadata_set_needs_check(pool
->pmd
)) {
2518 DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name
);
2519 set_pool_mode(pool
, PM_FAIL
);
2523 static void metadata_operation_failed(struct pool
*pool
, const char *op
, int r
)
2525 DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d",
2526 dm_device_name(pool
->pool_md
), op
, r
);
2528 abort_transaction(pool
);
2529 set_pool_mode(pool
, PM_READ_ONLY
);
2532 /*----------------------------------------------------------------*/
2535 * Mapping functions.
2539 * Called only while mapping a thin bio to hand it over to the workqueue.
2541 static void thin_defer_bio(struct thin_c
*tc
, struct bio
*bio
)
2543 unsigned long flags
;
2544 struct pool
*pool
= tc
->pool
;
2546 spin_lock_irqsave(&tc
->lock
, flags
);
2547 bio_list_add(&tc
->deferred_bio_list
, bio
);
2548 spin_unlock_irqrestore(&tc
->lock
, flags
);
2553 static void thin_defer_bio_with_throttle(struct thin_c
*tc
, struct bio
*bio
)
2555 struct pool
*pool
= tc
->pool
;
2557 throttle_lock(&pool
->throttle
);
2558 thin_defer_bio(tc
, bio
);
2559 throttle_unlock(&pool
->throttle
);
2562 static void thin_defer_cell(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
2564 unsigned long flags
;
2565 struct pool
*pool
= tc
->pool
;
2567 throttle_lock(&pool
->throttle
);
2568 spin_lock_irqsave(&tc
->lock
, flags
);
2569 list_add_tail(&cell
->user_list
, &tc
->deferred_cells
);
2570 spin_unlock_irqrestore(&tc
->lock
, flags
);
2571 throttle_unlock(&pool
->throttle
);
2576 static void thin_hook_bio(struct thin_c
*tc
, struct bio
*bio
)
2578 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
2581 h
->shared_read_entry
= NULL
;
2582 h
->all_io_entry
= NULL
;
2583 h
->overwrite_mapping
= NULL
;
2588 * Non-blocking function called from the thin target's map function.
2590 static int thin_bio_map(struct dm_target
*ti
, struct bio
*bio
)
2593 struct thin_c
*tc
= ti
->private;
2594 dm_block_t block
= get_bio_block(tc
, bio
);
2595 struct dm_thin_device
*td
= tc
->td
;
2596 struct dm_thin_lookup_result result
;
2597 struct dm_bio_prison_cell
*virt_cell
, *data_cell
;
2598 struct dm_cell_key key
;
2600 thin_hook_bio(tc
, bio
);
2602 if (tc
->requeue_mode
) {
2603 bio_endio(bio
, DM_ENDIO_REQUEUE
);
2604 return DM_MAPIO_SUBMITTED
;
2607 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
2609 return DM_MAPIO_SUBMITTED
;
2612 if (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
)) {
2613 thin_defer_bio_with_throttle(tc
, bio
);
2614 return DM_MAPIO_SUBMITTED
;
2618 * We must hold the virtual cell before doing the lookup, otherwise
2619 * there's a race with discard.
2621 build_virtual_key(tc
->td
, block
, &key
);
2622 if (bio_detain(tc
->pool
, &key
, bio
, &virt_cell
))
2623 return DM_MAPIO_SUBMITTED
;
2625 r
= dm_thin_find_block(td
, block
, 0, &result
);
2628 * Note that we defer readahead too.
2632 if (unlikely(result
.shared
)) {
2634 * We have a race condition here between the
2635 * result.shared value returned by the lookup and
2636 * snapshot creation, which may cause new
2639 * To avoid this always quiesce the origin before
2640 * taking the snap. You want to do this anyway to
2641 * ensure a consistent application view
2644 * More distant ancestors are irrelevant. The
2645 * shared flag will be set in their case.
2647 thin_defer_cell(tc
, virt_cell
);
2648 return DM_MAPIO_SUBMITTED
;
2651 build_data_key(tc
->td
, result
.block
, &key
);
2652 if (bio_detain(tc
->pool
, &key
, bio
, &data_cell
)) {
2653 cell_defer_no_holder(tc
, virt_cell
);
2654 return DM_MAPIO_SUBMITTED
;
2657 inc_all_io_entry(tc
->pool
, bio
);
2658 cell_defer_no_holder(tc
, data_cell
);
2659 cell_defer_no_holder(tc
, virt_cell
);
2661 remap(tc
, bio
, result
.block
);
2662 return DM_MAPIO_REMAPPED
;
2666 thin_defer_cell(tc
, virt_cell
);
2667 return DM_MAPIO_SUBMITTED
;
2671 * Must always call bio_io_error on failure.
2672 * dm_thin_find_block can fail with -EINVAL if the
2673 * pool is switched to fail-io mode.
2676 cell_defer_no_holder(tc
, virt_cell
);
2677 return DM_MAPIO_SUBMITTED
;
2681 static int pool_is_congested(struct dm_target_callbacks
*cb
, int bdi_bits
)
2683 struct pool_c
*pt
= container_of(cb
, struct pool_c
, callbacks
);
2684 struct request_queue
*q
;
2686 if (get_pool_mode(pt
->pool
) == PM_OUT_OF_DATA_SPACE
)
2689 q
= bdev_get_queue(pt
->data_dev
->bdev
);
2690 return bdi_congested(&q
->backing_dev_info
, bdi_bits
);
2693 static void requeue_bios(struct pool
*pool
)
2695 unsigned long flags
;
2699 list_for_each_entry_rcu(tc
, &pool
->active_thins
, list
) {
2700 spin_lock_irqsave(&tc
->lock
, flags
);
2701 bio_list_merge(&tc
->deferred_bio_list
, &tc
->retry_on_resume_list
);
2702 bio_list_init(&tc
->retry_on_resume_list
);
2703 spin_unlock_irqrestore(&tc
->lock
, flags
);
2708 /*----------------------------------------------------------------
2709 * Binding of control targets to a pool object
2710 *--------------------------------------------------------------*/
2711 static bool data_dev_supports_discard(struct pool_c
*pt
)
2713 struct request_queue
*q
= bdev_get_queue(pt
->data_dev
->bdev
);
2715 return q
&& blk_queue_discard(q
);
2718 static bool is_factor(sector_t block_size
, uint32_t n
)
2720 return !sector_div(block_size
, n
);
2724 * If discard_passdown was enabled verify that the data device
2725 * supports discards. Disable discard_passdown if not.
2727 static void disable_passdown_if_not_supported(struct pool_c
*pt
)
2729 struct pool
*pool
= pt
->pool
;
2730 struct block_device
*data_bdev
= pt
->data_dev
->bdev
;
2731 struct queue_limits
*data_limits
= &bdev_get_queue(data_bdev
)->limits
;
2732 const char *reason
= NULL
;
2733 char buf
[BDEVNAME_SIZE
];
2735 if (!pt
->adjusted_pf
.discard_passdown
)
2738 if (!data_dev_supports_discard(pt
))
2739 reason
= "discard unsupported";
2741 else if (data_limits
->max_discard_sectors
< pool
->sectors_per_block
)
2742 reason
= "max discard sectors smaller than a block";
2745 DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev
, buf
), reason
);
2746 pt
->adjusted_pf
.discard_passdown
= false;
2750 static int bind_control_target(struct pool
*pool
, struct dm_target
*ti
)
2752 struct pool_c
*pt
= ti
->private;
2755 * We want to make sure that a pool in PM_FAIL mode is never upgraded.
2757 enum pool_mode old_mode
= get_pool_mode(pool
);
2758 enum pool_mode new_mode
= pt
->adjusted_pf
.mode
;
2761 * Don't change the pool's mode until set_pool_mode() below.
2762 * Otherwise the pool's process_* function pointers may
2763 * not match the desired pool mode.
2765 pt
->adjusted_pf
.mode
= old_mode
;
2768 pool
->pf
= pt
->adjusted_pf
;
2769 pool
->low_water_blocks
= pt
->low_water_blocks
;
2771 set_pool_mode(pool
, new_mode
);
2776 static void unbind_control_target(struct pool
*pool
, struct dm_target
*ti
)
2782 /*----------------------------------------------------------------
2784 *--------------------------------------------------------------*/
2785 /* Initialize pool features. */
2786 static void pool_features_init(struct pool_features
*pf
)
2788 pf
->mode
= PM_WRITE
;
2789 pf
->zero_new_blocks
= true;
2790 pf
->discard_enabled
= true;
2791 pf
->discard_passdown
= true;
2792 pf
->error_if_no_space
= false;
2795 static void __pool_destroy(struct pool
*pool
)
2797 __pool_table_remove(pool
);
2799 vfree(pool
->cell_sort_array
);
2800 if (dm_pool_metadata_close(pool
->pmd
) < 0)
2801 DMWARN("%s: dm_pool_metadata_close() failed.", __func__
);
2803 dm_bio_prison_destroy(pool
->prison
);
2804 dm_kcopyd_client_destroy(pool
->copier
);
2807 destroy_workqueue(pool
->wq
);
2809 if (pool
->next_mapping
)
2810 mempool_free(pool
->next_mapping
, pool
->mapping_pool
);
2811 mempool_destroy(pool
->mapping_pool
);
2812 dm_deferred_set_destroy(pool
->shared_read_ds
);
2813 dm_deferred_set_destroy(pool
->all_io_ds
);
2817 static struct kmem_cache
*_new_mapping_cache
;
2819 static struct pool
*pool_create(struct mapped_device
*pool_md
,
2820 struct block_device
*metadata_dev
,
2821 unsigned long block_size
,
2822 int read_only
, char **error
)
2827 struct dm_pool_metadata
*pmd
;
2828 bool format_device
= read_only
? false : true;
2830 pmd
= dm_pool_metadata_open(metadata_dev
, block_size
, format_device
);
2832 *error
= "Error creating metadata object";
2833 return (struct pool
*)pmd
;
2836 pool
= kmalloc(sizeof(*pool
), GFP_KERNEL
);
2838 *error
= "Error allocating memory for pool";
2839 err_p
= ERR_PTR(-ENOMEM
);
2844 pool
->sectors_per_block
= block_size
;
2845 if (block_size
& (block_size
- 1))
2846 pool
->sectors_per_block_shift
= -1;
2848 pool
->sectors_per_block_shift
= __ffs(block_size
);
2849 pool
->low_water_blocks
= 0;
2850 pool_features_init(&pool
->pf
);
2851 pool
->prison
= dm_bio_prison_create();
2852 if (!pool
->prison
) {
2853 *error
= "Error creating pool's bio prison";
2854 err_p
= ERR_PTR(-ENOMEM
);
2858 pool
->copier
= dm_kcopyd_client_create(&dm_kcopyd_throttle
);
2859 if (IS_ERR(pool
->copier
)) {
2860 r
= PTR_ERR(pool
->copier
);
2861 *error
= "Error creating pool's kcopyd client";
2863 goto bad_kcopyd_client
;
2867 * Create singlethreaded workqueue that will service all devices
2868 * that use this metadata.
2870 pool
->wq
= alloc_ordered_workqueue("dm-" DM_MSG_PREFIX
, WQ_MEM_RECLAIM
);
2872 *error
= "Error creating pool's workqueue";
2873 err_p
= ERR_PTR(-ENOMEM
);
2877 throttle_init(&pool
->throttle
);
2878 INIT_WORK(&pool
->worker
, do_worker
);
2879 INIT_DELAYED_WORK(&pool
->waker
, do_waker
);
2880 INIT_DELAYED_WORK(&pool
->no_space_timeout
, do_no_space_timeout
);
2881 spin_lock_init(&pool
->lock
);
2882 bio_list_init(&pool
->deferred_flush_bios
);
2883 INIT_LIST_HEAD(&pool
->prepared_mappings
);
2884 INIT_LIST_HEAD(&pool
->prepared_discards
);
2885 INIT_LIST_HEAD(&pool
->active_thins
);
2886 pool
->low_water_triggered
= false;
2887 pool
->suspended
= true;
2889 pool
->shared_read_ds
= dm_deferred_set_create();
2890 if (!pool
->shared_read_ds
) {
2891 *error
= "Error creating pool's shared read deferred set";
2892 err_p
= ERR_PTR(-ENOMEM
);
2893 goto bad_shared_read_ds
;
2896 pool
->all_io_ds
= dm_deferred_set_create();
2897 if (!pool
->all_io_ds
) {
2898 *error
= "Error creating pool's all io deferred set";
2899 err_p
= ERR_PTR(-ENOMEM
);
2903 pool
->next_mapping
= NULL
;
2904 pool
->mapping_pool
= mempool_create_slab_pool(MAPPING_POOL_SIZE
,
2905 _new_mapping_cache
);
2906 if (!pool
->mapping_pool
) {
2907 *error
= "Error creating pool's mapping mempool";
2908 err_p
= ERR_PTR(-ENOMEM
);
2909 goto bad_mapping_pool
;
2912 pool
->cell_sort_array
= vmalloc(sizeof(*pool
->cell_sort_array
) * CELL_SORT_ARRAY_SIZE
);
2913 if (!pool
->cell_sort_array
) {
2914 *error
= "Error allocating cell sort array";
2915 err_p
= ERR_PTR(-ENOMEM
);
2916 goto bad_sort_array
;
2919 pool
->ref_count
= 1;
2920 pool
->last_commit_jiffies
= jiffies
;
2921 pool
->pool_md
= pool_md
;
2922 pool
->md_dev
= metadata_dev
;
2923 __pool_table_insert(pool
);
2928 mempool_destroy(pool
->mapping_pool
);
2930 dm_deferred_set_destroy(pool
->all_io_ds
);
2932 dm_deferred_set_destroy(pool
->shared_read_ds
);
2934 destroy_workqueue(pool
->wq
);
2936 dm_kcopyd_client_destroy(pool
->copier
);
2938 dm_bio_prison_destroy(pool
->prison
);
2942 if (dm_pool_metadata_close(pmd
))
2943 DMWARN("%s: dm_pool_metadata_close() failed.", __func__
);
2948 static void __pool_inc(struct pool
*pool
)
2950 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
2954 static void __pool_dec(struct pool
*pool
)
2956 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
2957 BUG_ON(!pool
->ref_count
);
2958 if (!--pool
->ref_count
)
2959 __pool_destroy(pool
);
2962 static struct pool
*__pool_find(struct mapped_device
*pool_md
,
2963 struct block_device
*metadata_dev
,
2964 unsigned long block_size
, int read_only
,
2965 char **error
, int *created
)
2967 struct pool
*pool
= __pool_table_lookup_metadata_dev(metadata_dev
);
2970 if (pool
->pool_md
!= pool_md
) {
2971 *error
= "metadata device already in use by a pool";
2972 return ERR_PTR(-EBUSY
);
2977 pool
= __pool_table_lookup(pool_md
);
2979 if (pool
->md_dev
!= metadata_dev
) {
2980 *error
= "different pool cannot replace a pool";
2981 return ERR_PTR(-EINVAL
);
2986 pool
= pool_create(pool_md
, metadata_dev
, block_size
, read_only
, error
);
2994 /*----------------------------------------------------------------
2995 * Pool target methods
2996 *--------------------------------------------------------------*/
2997 static void pool_dtr(struct dm_target
*ti
)
2999 struct pool_c
*pt
= ti
->private;
3001 mutex_lock(&dm_thin_pool_table
.mutex
);
3003 unbind_control_target(pt
->pool
, ti
);
3004 __pool_dec(pt
->pool
);
3005 dm_put_device(ti
, pt
->metadata_dev
);
3006 dm_put_device(ti
, pt
->data_dev
);
3009 mutex_unlock(&dm_thin_pool_table
.mutex
);
3012 static int parse_pool_features(struct dm_arg_set
*as
, struct pool_features
*pf
,
3013 struct dm_target
*ti
)
3017 const char *arg_name
;
3019 static struct dm_arg _args
[] = {
3020 {0, 4, "Invalid number of pool feature arguments"},
3024 * No feature arguments supplied.
3029 r
= dm_read_arg_group(_args
, as
, &argc
, &ti
->error
);
3033 while (argc
&& !r
) {
3034 arg_name
= dm_shift_arg(as
);
3037 if (!strcasecmp(arg_name
, "skip_block_zeroing"))
3038 pf
->zero_new_blocks
= false;
3040 else if (!strcasecmp(arg_name
, "ignore_discard"))
3041 pf
->discard_enabled
= false;
3043 else if (!strcasecmp(arg_name
, "no_discard_passdown"))
3044 pf
->discard_passdown
= false;
3046 else if (!strcasecmp(arg_name
, "read_only"))
3047 pf
->mode
= PM_READ_ONLY
;
3049 else if (!strcasecmp(arg_name
, "error_if_no_space"))
3050 pf
->error_if_no_space
= true;
3053 ti
->error
= "Unrecognised pool feature requested";
3062 static void metadata_low_callback(void *context
)
3064 struct pool
*pool
= context
;
3066 DMWARN("%s: reached low water mark for metadata device: sending event.",
3067 dm_device_name(pool
->pool_md
));
3069 dm_table_event(pool
->ti
->table
);
3072 static sector_t
get_dev_size(struct block_device
*bdev
)
3074 return i_size_read(bdev
->bd_inode
) >> SECTOR_SHIFT
;
3077 static void warn_if_metadata_device_too_big(struct block_device
*bdev
)
3079 sector_t metadata_dev_size
= get_dev_size(bdev
);
3080 char buffer
[BDEVNAME_SIZE
];
3082 if (metadata_dev_size
> THIN_METADATA_MAX_SECTORS_WARNING
)
3083 DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",
3084 bdevname(bdev
, buffer
), THIN_METADATA_MAX_SECTORS
);
3087 static sector_t
get_metadata_dev_size(struct block_device
*bdev
)
3089 sector_t metadata_dev_size
= get_dev_size(bdev
);
3091 if (metadata_dev_size
> THIN_METADATA_MAX_SECTORS
)
3092 metadata_dev_size
= THIN_METADATA_MAX_SECTORS
;
3094 return metadata_dev_size
;
3097 static dm_block_t
get_metadata_dev_size_in_blocks(struct block_device
*bdev
)
3099 sector_t metadata_dev_size
= get_metadata_dev_size(bdev
);
3101 sector_div(metadata_dev_size
, THIN_METADATA_BLOCK_SIZE
);
3103 return metadata_dev_size
;
3107 * When a metadata threshold is crossed a dm event is triggered, and
3108 * userland should respond by growing the metadata device. We could let
3109 * userland set the threshold, like we do with the data threshold, but I'm
3110 * not sure they know enough to do this well.
3112 static dm_block_t
calc_metadata_threshold(struct pool_c
*pt
)
3115 * 4M is ample for all ops with the possible exception of thin
3116 * device deletion which is harmless if it fails (just retry the
3117 * delete after you've grown the device).
3119 dm_block_t quarter
= get_metadata_dev_size_in_blocks(pt
->metadata_dev
->bdev
) / 4;
3120 return min((dm_block_t
)1024ULL /* 4M */, quarter
);
3124 * thin-pool <metadata dev> <data dev>
3125 * <data block size (sectors)>
3126 * <low water mark (blocks)>
3127 * [<#feature args> [<arg>]*]
3129 * Optional feature arguments are:
3130 * skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
3131 * ignore_discard: disable discard
3132 * no_discard_passdown: don't pass discards down to the data device
3133 * read_only: Don't allow any changes to be made to the pool metadata.
3134 * error_if_no_space: error IOs, instead of queueing, if no space.
3136 static int pool_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
3138 int r
, pool_created
= 0;
3141 struct pool_features pf
;
3142 struct dm_arg_set as
;
3143 struct dm_dev
*data_dev
;
3144 unsigned long block_size
;
3145 dm_block_t low_water_blocks
;
3146 struct dm_dev
*metadata_dev
;
3147 fmode_t metadata_mode
;
3150 * FIXME Remove validation from scope of lock.
3152 mutex_lock(&dm_thin_pool_table
.mutex
);
3155 ti
->error
= "Invalid argument count";
3164 * Set default pool features.
3166 pool_features_init(&pf
);
3168 dm_consume_args(&as
, 4);
3169 r
= parse_pool_features(&as
, &pf
, ti
);
3173 metadata_mode
= FMODE_READ
| ((pf
.mode
== PM_READ_ONLY
) ? 0 : FMODE_WRITE
);
3174 r
= dm_get_device(ti
, argv
[0], metadata_mode
, &metadata_dev
);
3176 ti
->error
= "Error opening metadata block device";
3179 warn_if_metadata_device_too_big(metadata_dev
->bdev
);
3181 r
= dm_get_device(ti
, argv
[1], FMODE_READ
| FMODE_WRITE
, &data_dev
);
3183 ti
->error
= "Error getting data device";
3187 if (kstrtoul(argv
[2], 10, &block_size
) || !block_size
||
3188 block_size
< DATA_DEV_BLOCK_SIZE_MIN_SECTORS
||
3189 block_size
> DATA_DEV_BLOCK_SIZE_MAX_SECTORS
||
3190 block_size
& (DATA_DEV_BLOCK_SIZE_MIN_SECTORS
- 1)) {
3191 ti
->error
= "Invalid block size";
3196 if (kstrtoull(argv
[3], 10, (unsigned long long *)&low_water_blocks
)) {
3197 ti
->error
= "Invalid low water mark";
3202 pt
= kzalloc(sizeof(*pt
), GFP_KERNEL
);
3208 pool
= __pool_find(dm_table_get_md(ti
->table
), metadata_dev
->bdev
,
3209 block_size
, pf
.mode
== PM_READ_ONLY
, &ti
->error
, &pool_created
);
3216 * 'pool_created' reflects whether this is the first table load.
3217 * Top level discard support is not allowed to be changed after
3218 * initial load. This would require a pool reload to trigger thin
3221 if (!pool_created
&& pf
.discard_enabled
!= pool
->pf
.discard_enabled
) {
3222 ti
->error
= "Discard support cannot be disabled once enabled";
3224 goto out_flags_changed
;
3229 pt
->metadata_dev
= metadata_dev
;
3230 pt
->data_dev
= data_dev
;
3231 pt
->low_water_blocks
= low_water_blocks
;
3232 pt
->adjusted_pf
= pt
->requested_pf
= pf
;
3233 ti
->num_flush_bios
= 1;
3236 * Only need to enable discards if the pool should pass
3237 * them down to the data device. The thin device's discard
3238 * processing will cause mappings to be removed from the btree.
3240 ti
->discard_zeroes_data_unsupported
= true;
3241 if (pf
.discard_enabled
&& pf
.discard_passdown
) {
3242 ti
->num_discard_bios
= 1;
3245 * Setting 'discards_supported' circumvents the normal
3246 * stacking of discard limits (this keeps the pool and
3247 * thin devices' discard limits consistent).
3249 ti
->discards_supported
= true;
3253 r
= dm_pool_register_metadata_threshold(pt
->pool
->pmd
,
3254 calc_metadata_threshold(pt
),
3255 metadata_low_callback
,
3260 pt
->callbacks
.congested_fn
= pool_is_congested
;
3261 dm_table_add_target_callbacks(ti
->table
, &pt
->callbacks
);
3263 mutex_unlock(&dm_thin_pool_table
.mutex
);
3272 dm_put_device(ti
, data_dev
);
3274 dm_put_device(ti
, metadata_dev
);
3276 mutex_unlock(&dm_thin_pool_table
.mutex
);
3281 static int pool_map(struct dm_target
*ti
, struct bio
*bio
)
3284 struct pool_c
*pt
= ti
->private;
3285 struct pool
*pool
= pt
->pool
;
3286 unsigned long flags
;
3289 * As this is a singleton target, ti->begin is always zero.
3291 spin_lock_irqsave(&pool
->lock
, flags
);
3292 bio
->bi_bdev
= pt
->data_dev
->bdev
;
3293 r
= DM_MAPIO_REMAPPED
;
3294 spin_unlock_irqrestore(&pool
->lock
, flags
);
3299 static int maybe_resize_data_dev(struct dm_target
*ti
, bool *need_commit
)
3302 struct pool_c
*pt
= ti
->private;
3303 struct pool
*pool
= pt
->pool
;
3304 sector_t data_size
= ti
->len
;
3305 dm_block_t sb_data_size
;
3307 *need_commit
= false;
3309 (void) sector_div(data_size
, pool
->sectors_per_block
);
3311 r
= dm_pool_get_data_dev_size(pool
->pmd
, &sb_data_size
);
3313 DMERR("%s: failed to retrieve data device size",
3314 dm_device_name(pool
->pool_md
));
3318 if (data_size
< sb_data_size
) {
3319 DMERR("%s: pool target (%llu blocks) too small: expected %llu",
3320 dm_device_name(pool
->pool_md
),
3321 (unsigned long long)data_size
, sb_data_size
);
3324 } else if (data_size
> sb_data_size
) {
3325 if (dm_pool_metadata_needs_check(pool
->pmd
)) {
3326 DMERR("%s: unable to grow the data device until repaired.",
3327 dm_device_name(pool
->pool_md
));
3332 DMINFO("%s: growing the data device from %llu to %llu blocks",
3333 dm_device_name(pool
->pool_md
),
3334 sb_data_size
, (unsigned long long)data_size
);
3335 r
= dm_pool_resize_data_dev(pool
->pmd
, data_size
);
3337 metadata_operation_failed(pool
, "dm_pool_resize_data_dev", r
);
3341 *need_commit
= true;
3347 static int maybe_resize_metadata_dev(struct dm_target
*ti
, bool *need_commit
)
3350 struct pool_c
*pt
= ti
->private;
3351 struct pool
*pool
= pt
->pool
;
3352 dm_block_t metadata_dev_size
, sb_metadata_dev_size
;
3354 *need_commit
= false;
3356 metadata_dev_size
= get_metadata_dev_size_in_blocks(pool
->md_dev
);
3358 r
= dm_pool_get_metadata_dev_size(pool
->pmd
, &sb_metadata_dev_size
);
3360 DMERR("%s: failed to retrieve metadata device size",
3361 dm_device_name(pool
->pool_md
));
3365 if (metadata_dev_size
< sb_metadata_dev_size
) {
3366 DMERR("%s: metadata device (%llu blocks) too small: expected %llu",
3367 dm_device_name(pool
->pool_md
),
3368 metadata_dev_size
, sb_metadata_dev_size
);
3371 } else if (metadata_dev_size
> sb_metadata_dev_size
) {
3372 if (dm_pool_metadata_needs_check(pool
->pmd
)) {
3373 DMERR("%s: unable to grow the metadata device until repaired.",
3374 dm_device_name(pool
->pool_md
));
3378 warn_if_metadata_device_too_big(pool
->md_dev
);
3379 DMINFO("%s: growing the metadata device from %llu to %llu blocks",
3380 dm_device_name(pool
->pool_md
),
3381 sb_metadata_dev_size
, metadata_dev_size
);
3382 r
= dm_pool_resize_metadata_dev(pool
->pmd
, metadata_dev_size
);
3384 metadata_operation_failed(pool
, "dm_pool_resize_metadata_dev", r
);
3388 *need_commit
= true;
3395 * Retrieves the number of blocks of the data device from
3396 * the superblock and compares it to the actual device size,
3397 * thus resizing the data device in case it has grown.
3399 * This both copes with opening preallocated data devices in the ctr
3400 * being followed by a resume
3402 * calling the resume method individually after userspace has
3403 * grown the data device in reaction to a table event.
3405 static int pool_preresume(struct dm_target
*ti
)
3408 bool need_commit1
, need_commit2
;
3409 struct pool_c
*pt
= ti
->private;
3410 struct pool
*pool
= pt
->pool
;
3413 * Take control of the pool object.
3415 r
= bind_control_target(pool
, ti
);
3419 r
= maybe_resize_data_dev(ti
, &need_commit1
);
3423 r
= maybe_resize_metadata_dev(ti
, &need_commit2
);
3427 if (need_commit1
|| need_commit2
)
3428 (void) commit(pool
);
3433 static void pool_suspend_active_thins(struct pool
*pool
)
3437 /* Suspend all active thin devices */
3438 tc
= get_first_thin(pool
);
3440 dm_internal_suspend_noflush(tc
->thin_md
);
3441 tc
= get_next_thin(pool
, tc
);
3445 static void pool_resume_active_thins(struct pool
*pool
)
3449 /* Resume all active thin devices */
3450 tc
= get_first_thin(pool
);
3452 dm_internal_resume(tc
->thin_md
);
3453 tc
= get_next_thin(pool
, tc
);
3457 static void pool_resume(struct dm_target
*ti
)
3459 struct pool_c
*pt
= ti
->private;
3460 struct pool
*pool
= pt
->pool
;
3461 unsigned long flags
;
3464 * Must requeue active_thins' bios and then resume
3465 * active_thins _before_ clearing 'suspend' flag.
3468 pool_resume_active_thins(pool
);
3470 spin_lock_irqsave(&pool
->lock
, flags
);
3471 pool
->low_water_triggered
= false;
3472 pool
->suspended
= false;
3473 spin_unlock_irqrestore(&pool
->lock
, flags
);
3475 do_waker(&pool
->waker
.work
);
3478 static void pool_presuspend(struct dm_target
*ti
)
3480 struct pool_c
*pt
= ti
->private;
3481 struct pool
*pool
= pt
->pool
;
3482 unsigned long flags
;
3484 spin_lock_irqsave(&pool
->lock
, flags
);
3485 pool
->suspended
= true;
3486 spin_unlock_irqrestore(&pool
->lock
, flags
);
3488 pool_suspend_active_thins(pool
);
3491 static void pool_presuspend_undo(struct dm_target
*ti
)
3493 struct pool_c
*pt
= ti
->private;
3494 struct pool
*pool
= pt
->pool
;
3495 unsigned long flags
;
3497 pool_resume_active_thins(pool
);
3499 spin_lock_irqsave(&pool
->lock
, flags
);
3500 pool
->suspended
= false;
3501 spin_unlock_irqrestore(&pool
->lock
, flags
);
3504 static void pool_postsuspend(struct dm_target
*ti
)
3506 struct pool_c
*pt
= ti
->private;
3507 struct pool
*pool
= pt
->pool
;
3509 cancel_delayed_work(&pool
->waker
);
3510 cancel_delayed_work(&pool
->no_space_timeout
);
3511 flush_workqueue(pool
->wq
);
3512 (void) commit(pool
);
3515 static int check_arg_count(unsigned argc
, unsigned args_required
)
3517 if (argc
!= args_required
) {
3518 DMWARN("Message received with %u arguments instead of %u.",
3519 argc
, args_required
);
3526 static int read_dev_id(char *arg
, dm_thin_id
*dev_id
, int warning
)
3528 if (!kstrtoull(arg
, 10, (unsigned long long *)dev_id
) &&
3529 *dev_id
<= MAX_DEV_ID
)
3533 DMWARN("Message received with invalid device id: %s", arg
);
3538 static int process_create_thin_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3543 r
= check_arg_count(argc
, 2);
3547 r
= read_dev_id(argv
[1], &dev_id
, 1);
3551 r
= dm_pool_create_thin(pool
->pmd
, dev_id
);
3553 DMWARN("Creation of new thinly-provisioned device with id %s failed.",
3561 static int process_create_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3564 dm_thin_id origin_dev_id
;
3567 r
= check_arg_count(argc
, 3);
3571 r
= read_dev_id(argv
[1], &dev_id
, 1);
3575 r
= read_dev_id(argv
[2], &origin_dev_id
, 1);
3579 r
= dm_pool_create_snap(pool
->pmd
, dev_id
, origin_dev_id
);
3581 DMWARN("Creation of new snapshot %s of device %s failed.",
3589 static int process_delete_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3594 r
= check_arg_count(argc
, 2);
3598 r
= read_dev_id(argv
[1], &dev_id
, 1);
3602 r
= dm_pool_delete_thin_device(pool
->pmd
, dev_id
);
3604 DMWARN("Deletion of thin device %s failed.", argv
[1]);
3609 static int process_set_transaction_id_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3611 dm_thin_id old_id
, new_id
;
3614 r
= check_arg_count(argc
, 3);
3618 if (kstrtoull(argv
[1], 10, (unsigned long long *)&old_id
)) {
3619 DMWARN("set_transaction_id message: Unrecognised id %s.", argv
[1]);
3623 if (kstrtoull(argv
[2], 10, (unsigned long long *)&new_id
)) {
3624 DMWARN("set_transaction_id message: Unrecognised new id %s.", argv
[2]);
3628 r
= dm_pool_set_metadata_transaction_id(pool
->pmd
, old_id
, new_id
);
3630 DMWARN("Failed to change transaction id from %s to %s.",
3638 static int process_reserve_metadata_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3642 r
= check_arg_count(argc
, 1);
3646 (void) commit(pool
);
3648 r
= dm_pool_reserve_metadata_snap(pool
->pmd
);
3650 DMWARN("reserve_metadata_snap message failed.");
3655 static int process_release_metadata_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3659 r
= check_arg_count(argc
, 1);
3663 r
= dm_pool_release_metadata_snap(pool
->pmd
);
3665 DMWARN("release_metadata_snap message failed.");
3671 * Messages supported:
3672 * create_thin <dev_id>
3673 * create_snap <dev_id> <origin_id>
3675 * set_transaction_id <current_trans_id> <new_trans_id>
3676 * reserve_metadata_snap
3677 * release_metadata_snap
3679 static int pool_message(struct dm_target
*ti
, unsigned argc
, char **argv
)
3682 struct pool_c
*pt
= ti
->private;
3683 struct pool
*pool
= pt
->pool
;
3685 if (get_pool_mode(pool
) >= PM_READ_ONLY
) {
3686 DMERR("%s: unable to service pool target messages in READ_ONLY or FAIL mode",
3687 dm_device_name(pool
->pool_md
));
3691 if (!strcasecmp(argv
[0], "create_thin"))
3692 r
= process_create_thin_mesg(argc
, argv
, pool
);
3694 else if (!strcasecmp(argv
[0], "create_snap"))
3695 r
= process_create_snap_mesg(argc
, argv
, pool
);
3697 else if (!strcasecmp(argv
[0], "delete"))
3698 r
= process_delete_mesg(argc
, argv
, pool
);
3700 else if (!strcasecmp(argv
[0], "set_transaction_id"))
3701 r
= process_set_transaction_id_mesg(argc
, argv
, pool
);
3703 else if (!strcasecmp(argv
[0], "reserve_metadata_snap"))
3704 r
= process_reserve_metadata_snap_mesg(argc
, argv
, pool
);
3706 else if (!strcasecmp(argv
[0], "release_metadata_snap"))
3707 r
= process_release_metadata_snap_mesg(argc
, argv
, pool
);
3710 DMWARN("Unrecognised thin pool target message received: %s", argv
[0]);
3713 (void) commit(pool
);
3718 static void emit_flags(struct pool_features
*pf
, char *result
,
3719 unsigned sz
, unsigned maxlen
)
3721 unsigned count
= !pf
->zero_new_blocks
+ !pf
->discard_enabled
+
3722 !pf
->discard_passdown
+ (pf
->mode
== PM_READ_ONLY
) +
3723 pf
->error_if_no_space
;
3724 DMEMIT("%u ", count
);
3726 if (!pf
->zero_new_blocks
)
3727 DMEMIT("skip_block_zeroing ");
3729 if (!pf
->discard_enabled
)
3730 DMEMIT("ignore_discard ");
3732 if (!pf
->discard_passdown
)
3733 DMEMIT("no_discard_passdown ");
3735 if (pf
->mode
== PM_READ_ONLY
)
3736 DMEMIT("read_only ");
3738 if (pf
->error_if_no_space
)
3739 DMEMIT("error_if_no_space ");
3744 * <transaction id> <used metadata sectors>/<total metadata sectors>
3745 * <used data sectors>/<total data sectors> <held metadata root>
3746 * <pool mode> <discard config> <no space config> <needs_check>
3748 static void pool_status(struct dm_target
*ti
, status_type_t type
,
3749 unsigned status_flags
, char *result
, unsigned maxlen
)
3753 uint64_t transaction_id
;
3754 dm_block_t nr_free_blocks_data
;
3755 dm_block_t nr_free_blocks_metadata
;
3756 dm_block_t nr_blocks_data
;
3757 dm_block_t nr_blocks_metadata
;
3758 dm_block_t held_root
;
3759 char buf
[BDEVNAME_SIZE
];
3760 char buf2
[BDEVNAME_SIZE
];
3761 struct pool_c
*pt
= ti
->private;
3762 struct pool
*pool
= pt
->pool
;
3765 case STATUSTYPE_INFO
:
3766 if (get_pool_mode(pool
) == PM_FAIL
) {
3771 /* Commit to ensure statistics aren't out-of-date */
3772 if (!(status_flags
& DM_STATUS_NOFLUSH_FLAG
) && !dm_suspended(ti
))
3773 (void) commit(pool
);
3775 r
= dm_pool_get_metadata_transaction_id(pool
->pmd
, &transaction_id
);
3777 DMERR("%s: dm_pool_get_metadata_transaction_id returned %d",
3778 dm_device_name(pool
->pool_md
), r
);
3782 r
= dm_pool_get_free_metadata_block_count(pool
->pmd
, &nr_free_blocks_metadata
);
3784 DMERR("%s: dm_pool_get_free_metadata_block_count returned %d",
3785 dm_device_name(pool
->pool_md
), r
);
3789 r
= dm_pool_get_metadata_dev_size(pool
->pmd
, &nr_blocks_metadata
);
3791 DMERR("%s: dm_pool_get_metadata_dev_size returned %d",
3792 dm_device_name(pool
->pool_md
), r
);
3796 r
= dm_pool_get_free_block_count(pool
->pmd
, &nr_free_blocks_data
);
3798 DMERR("%s: dm_pool_get_free_block_count returned %d",
3799 dm_device_name(pool
->pool_md
), r
);
3803 r
= dm_pool_get_data_dev_size(pool
->pmd
, &nr_blocks_data
);
3805 DMERR("%s: dm_pool_get_data_dev_size returned %d",
3806 dm_device_name(pool
->pool_md
), r
);
3810 r
= dm_pool_get_metadata_snap(pool
->pmd
, &held_root
);
3812 DMERR("%s: dm_pool_get_metadata_snap returned %d",
3813 dm_device_name(pool
->pool_md
), r
);
3817 DMEMIT("%llu %llu/%llu %llu/%llu ",
3818 (unsigned long long)transaction_id
,
3819 (unsigned long long)(nr_blocks_metadata
- nr_free_blocks_metadata
),
3820 (unsigned long long)nr_blocks_metadata
,
3821 (unsigned long long)(nr_blocks_data
- nr_free_blocks_data
),
3822 (unsigned long long)nr_blocks_data
);
3825 DMEMIT("%llu ", held_root
);
3829 if (pool
->pf
.mode
== PM_OUT_OF_DATA_SPACE
)
3830 DMEMIT("out_of_data_space ");
3831 else if (pool
->pf
.mode
== PM_READ_ONLY
)
3836 if (!pool
->pf
.discard_enabled
)
3837 DMEMIT("ignore_discard ");
3838 else if (pool
->pf
.discard_passdown
)
3839 DMEMIT("discard_passdown ");
3841 DMEMIT("no_discard_passdown ");
3843 if (pool
->pf
.error_if_no_space
)
3844 DMEMIT("error_if_no_space ");
3846 DMEMIT("queue_if_no_space ");
3848 if (dm_pool_metadata_needs_check(pool
->pmd
))
3849 DMEMIT("needs_check ");
3855 case STATUSTYPE_TABLE
:
3856 DMEMIT("%s %s %lu %llu ",
3857 format_dev_t(buf
, pt
->metadata_dev
->bdev
->bd_dev
),
3858 format_dev_t(buf2
, pt
->data_dev
->bdev
->bd_dev
),
3859 (unsigned long)pool
->sectors_per_block
,
3860 (unsigned long long)pt
->low_water_blocks
);
3861 emit_flags(&pt
->requested_pf
, result
, sz
, maxlen
);
3870 static int pool_iterate_devices(struct dm_target
*ti
,
3871 iterate_devices_callout_fn fn
, void *data
)
3873 struct pool_c
*pt
= ti
->private;
3875 return fn(ti
, pt
->data_dev
, 0, ti
->len
, data
);
3878 static int pool_merge(struct dm_target
*ti
, struct bvec_merge_data
*bvm
,
3879 struct bio_vec
*biovec
, int max_size
)
3881 struct pool_c
*pt
= ti
->private;
3882 struct request_queue
*q
= bdev_get_queue(pt
->data_dev
->bdev
);
3884 if (!q
->merge_bvec_fn
)
3887 bvm
->bi_bdev
= pt
->data_dev
->bdev
;
3889 return min(max_size
, q
->merge_bvec_fn(q
, bvm
, biovec
));
3892 static void pool_io_hints(struct dm_target
*ti
, struct queue_limits
*limits
)
3894 struct pool_c
*pt
= ti
->private;
3895 struct pool
*pool
= pt
->pool
;
3896 sector_t io_opt_sectors
= limits
->io_opt
>> SECTOR_SHIFT
;
3899 * If max_sectors is smaller than pool->sectors_per_block adjust it
3900 * to the highest possible power-of-2 factor of pool->sectors_per_block.
3901 * This is especially beneficial when the pool's data device is a RAID
3902 * device that has a full stripe width that matches pool->sectors_per_block
3903 * -- because even though partial RAID stripe-sized IOs will be issued to a
3904 * single RAID stripe; when aggregated they will end on a full RAID stripe
3905 * boundary.. which avoids additional partial RAID stripe writes cascading
3907 if (limits
->max_sectors
< pool
->sectors_per_block
) {
3908 while (!is_factor(pool
->sectors_per_block
, limits
->max_sectors
)) {
3909 if ((limits
->max_sectors
& (limits
->max_sectors
- 1)) == 0)
3910 limits
->max_sectors
--;
3911 limits
->max_sectors
= rounddown_pow_of_two(limits
->max_sectors
);
3916 * If the system-determined stacked limits are compatible with the
3917 * pool's blocksize (io_opt is a factor) do not override them.
3919 if (io_opt_sectors
< pool
->sectors_per_block
||
3920 !is_factor(io_opt_sectors
, pool
->sectors_per_block
)) {
3921 if (is_factor(pool
->sectors_per_block
, limits
->max_sectors
))
3922 blk_limits_io_min(limits
, limits
->max_sectors
<< SECTOR_SHIFT
);
3924 blk_limits_io_min(limits
, pool
->sectors_per_block
<< SECTOR_SHIFT
);
3925 blk_limits_io_opt(limits
, pool
->sectors_per_block
<< SECTOR_SHIFT
);
3929 * pt->adjusted_pf is a staging area for the actual features to use.
3930 * They get transferred to the live pool in bind_control_target()
3931 * called from pool_preresume().
3933 if (!pt
->adjusted_pf
.discard_enabled
) {
3935 * Must explicitly disallow stacking discard limits otherwise the
3936 * block layer will stack them if pool's data device has support.
3937 * QUEUE_FLAG_DISCARD wouldn't be set but there is no way for the
3938 * user to see that, so make sure to set all discard limits to 0.
3940 limits
->discard_granularity
= 0;
3944 disable_passdown_if_not_supported(pt
);
3947 * The pool uses the same discard limits as the underlying data
3948 * device. DM core has already set this up.
3952 static struct target_type pool_target
= {
3953 .name
= "thin-pool",
3954 .features
= DM_TARGET_SINGLETON
| DM_TARGET_ALWAYS_WRITEABLE
|
3955 DM_TARGET_IMMUTABLE
,
3956 .version
= {1, 16, 0},
3957 .module
= THIS_MODULE
,
3961 .presuspend
= pool_presuspend
,
3962 .presuspend_undo
= pool_presuspend_undo
,
3963 .postsuspend
= pool_postsuspend
,
3964 .preresume
= pool_preresume
,
3965 .resume
= pool_resume
,
3966 .message
= pool_message
,
3967 .status
= pool_status
,
3968 .merge
= pool_merge
,
3969 .iterate_devices
= pool_iterate_devices
,
3970 .io_hints
= pool_io_hints
,
3973 /*----------------------------------------------------------------
3974 * Thin target methods
3975 *--------------------------------------------------------------*/
3976 static void thin_get(struct thin_c
*tc
)
3978 atomic_inc(&tc
->refcount
);
3981 static void thin_put(struct thin_c
*tc
)
3983 if (atomic_dec_and_test(&tc
->refcount
))
3984 complete(&tc
->can_destroy
);
3987 static void thin_dtr(struct dm_target
*ti
)
3989 struct thin_c
*tc
= ti
->private;
3990 unsigned long flags
;
3992 spin_lock_irqsave(&tc
->pool
->lock
, flags
);
3993 list_del_rcu(&tc
->list
);
3994 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
3998 wait_for_completion(&tc
->can_destroy
);
4000 mutex_lock(&dm_thin_pool_table
.mutex
);
4002 __pool_dec(tc
->pool
);
4003 dm_pool_close_thin_device(tc
->td
);
4004 dm_put_device(ti
, tc
->pool_dev
);
4006 dm_put_device(ti
, tc
->origin_dev
);
4009 mutex_unlock(&dm_thin_pool_table
.mutex
);
4013 * Thin target parameters:
4015 * <pool_dev> <dev_id> [origin_dev]
4017 * pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
4018 * dev_id: the internal device identifier
4019 * origin_dev: a device external to the pool that should act as the origin
4021 * If the pool device has discards disabled, they get disabled for the thin
4024 static int thin_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
4028 struct dm_dev
*pool_dev
, *origin_dev
;
4029 struct mapped_device
*pool_md
;
4030 unsigned long flags
;
4032 mutex_lock(&dm_thin_pool_table
.mutex
);
4034 if (argc
!= 2 && argc
!= 3) {
4035 ti
->error
= "Invalid argument count";
4040 tc
= ti
->private = kzalloc(sizeof(*tc
), GFP_KERNEL
);
4042 ti
->error
= "Out of memory";
4046 tc
->thin_md
= dm_table_get_md(ti
->table
);
4047 spin_lock_init(&tc
->lock
);
4048 INIT_LIST_HEAD(&tc
->deferred_cells
);
4049 bio_list_init(&tc
->deferred_bio_list
);
4050 bio_list_init(&tc
->retry_on_resume_list
);
4051 tc
->sort_bio_list
= RB_ROOT
;
4054 r
= dm_get_device(ti
, argv
[2], FMODE_READ
, &origin_dev
);
4056 ti
->error
= "Error opening origin device";
4057 goto bad_origin_dev
;
4059 tc
->origin_dev
= origin_dev
;
4062 r
= dm_get_device(ti
, argv
[0], dm_table_get_mode(ti
->table
), &pool_dev
);
4064 ti
->error
= "Error opening pool device";
4067 tc
->pool_dev
= pool_dev
;
4069 if (read_dev_id(argv
[1], (unsigned long long *)&tc
->dev_id
, 0)) {
4070 ti
->error
= "Invalid device id";
4075 pool_md
= dm_get_md(tc
->pool_dev
->bdev
->bd_dev
);
4077 ti
->error
= "Couldn't get pool mapped device";
4082 tc
->pool
= __pool_table_lookup(pool_md
);
4084 ti
->error
= "Couldn't find pool object";
4086 goto bad_pool_lookup
;
4088 __pool_inc(tc
->pool
);
4090 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
4091 ti
->error
= "Couldn't open thin device, Pool is in fail mode";
4096 r
= dm_pool_open_thin_device(tc
->pool
->pmd
, tc
->dev_id
, &tc
->td
);
4098 ti
->error
= "Couldn't open thin internal device";
4102 r
= dm_set_target_max_io_len(ti
, tc
->pool
->sectors_per_block
);
4106 ti
->num_flush_bios
= 1;
4107 ti
->flush_supported
= true;
4108 ti
->per_bio_data_size
= sizeof(struct dm_thin_endio_hook
);
4110 /* In case the pool supports discards, pass them on. */
4111 ti
->discard_zeroes_data_unsupported
= true;
4112 if (tc
->pool
->pf
.discard_enabled
) {
4113 ti
->discards_supported
= true;
4114 ti
->num_discard_bios
= 1;
4115 ti
->split_discard_bios
= false;
4118 mutex_unlock(&dm_thin_pool_table
.mutex
);
4120 spin_lock_irqsave(&tc
->pool
->lock
, flags
);
4121 if (tc
->pool
->suspended
) {
4122 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
4123 mutex_lock(&dm_thin_pool_table
.mutex
); /* reacquire for __pool_dec */
4124 ti
->error
= "Unable to activate thin device while pool is suspended";
4128 atomic_set(&tc
->refcount
, 1);
4129 init_completion(&tc
->can_destroy
);
4130 list_add_tail_rcu(&tc
->list
, &tc
->pool
->active_thins
);
4131 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
4133 * This synchronize_rcu() call is needed here otherwise we risk a
4134 * wake_worker() call finding no bios to process (because the newly
4135 * added tc isn't yet visible). So this reduces latency since we
4136 * aren't then dependent on the periodic commit to wake_worker().
4145 dm_pool_close_thin_device(tc
->td
);
4147 __pool_dec(tc
->pool
);
4151 dm_put_device(ti
, tc
->pool_dev
);
4154 dm_put_device(ti
, tc
->origin_dev
);
4158 mutex_unlock(&dm_thin_pool_table
.mutex
);
4163 static int thin_map(struct dm_target
*ti
, struct bio
*bio
)
4165 bio
->bi_iter
.bi_sector
= dm_target_offset(ti
, bio
->bi_iter
.bi_sector
);
4167 return thin_bio_map(ti
, bio
);
4170 static int thin_endio(struct dm_target
*ti
, struct bio
*bio
, int err
)
4172 unsigned long flags
;
4173 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
4174 struct list_head work
;
4175 struct dm_thin_new_mapping
*m
, *tmp
;
4176 struct pool
*pool
= h
->tc
->pool
;
4178 if (h
->shared_read_entry
) {
4179 INIT_LIST_HEAD(&work
);
4180 dm_deferred_entry_dec(h
->shared_read_entry
, &work
);
4182 spin_lock_irqsave(&pool
->lock
, flags
);
4183 list_for_each_entry_safe(m
, tmp
, &work
, list
) {
4185 __complete_mapping_preparation(m
);
4187 spin_unlock_irqrestore(&pool
->lock
, flags
);
4190 if (h
->all_io_entry
) {
4191 INIT_LIST_HEAD(&work
);
4192 dm_deferred_entry_dec(h
->all_io_entry
, &work
);
4193 if (!list_empty(&work
)) {
4194 spin_lock_irqsave(&pool
->lock
, flags
);
4195 list_for_each_entry_safe(m
, tmp
, &work
, list
)
4196 list_add_tail(&m
->list
, &pool
->prepared_discards
);
4197 spin_unlock_irqrestore(&pool
->lock
, flags
);
4203 cell_defer_no_holder(h
->tc
, h
->cell
);
4208 static void thin_presuspend(struct dm_target
*ti
)
4210 struct thin_c
*tc
= ti
->private;
4212 if (dm_noflush_suspending(ti
))
4213 noflush_work(tc
, do_noflush_start
);
4216 static void thin_postsuspend(struct dm_target
*ti
)
4218 struct thin_c
*tc
= ti
->private;
4221 * The dm_noflush_suspending flag has been cleared by now, so
4222 * unfortunately we must always run this.
4224 noflush_work(tc
, do_noflush_stop
);
4227 static int thin_preresume(struct dm_target
*ti
)
4229 struct thin_c
*tc
= ti
->private;
4232 tc
->origin_size
= get_dev_size(tc
->origin_dev
->bdev
);
4238 * <nr mapped sectors> <highest mapped sector>
4240 static void thin_status(struct dm_target
*ti
, status_type_t type
,
4241 unsigned status_flags
, char *result
, unsigned maxlen
)
4245 dm_block_t mapped
, highest
;
4246 char buf
[BDEVNAME_SIZE
];
4247 struct thin_c
*tc
= ti
->private;
4249 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
4258 case STATUSTYPE_INFO
:
4259 r
= dm_thin_get_mapped_count(tc
->td
, &mapped
);
4261 DMERR("dm_thin_get_mapped_count returned %d", r
);
4265 r
= dm_thin_get_highest_mapped_block(tc
->td
, &highest
);
4267 DMERR("dm_thin_get_highest_mapped_block returned %d", r
);
4271 DMEMIT("%llu ", mapped
* tc
->pool
->sectors_per_block
);
4273 DMEMIT("%llu", ((highest
+ 1) *
4274 tc
->pool
->sectors_per_block
) - 1);
4279 case STATUSTYPE_TABLE
:
4281 format_dev_t(buf
, tc
->pool_dev
->bdev
->bd_dev
),
4282 (unsigned long) tc
->dev_id
);
4284 DMEMIT(" %s", format_dev_t(buf
, tc
->origin_dev
->bdev
->bd_dev
));
4295 static int thin_merge(struct dm_target
*ti
, struct bvec_merge_data
*bvm
,
4296 struct bio_vec
*biovec
, int max_size
)
4298 struct thin_c
*tc
= ti
->private;
4299 struct request_queue
*q
= bdev_get_queue(tc
->pool_dev
->bdev
);
4301 if (!q
->merge_bvec_fn
)
4304 bvm
->bi_bdev
= tc
->pool_dev
->bdev
;
4305 bvm
->bi_sector
= dm_target_offset(ti
, bvm
->bi_sector
);
4307 return min(max_size
, q
->merge_bvec_fn(q
, bvm
, biovec
));
4310 static int thin_iterate_devices(struct dm_target
*ti
,
4311 iterate_devices_callout_fn fn
, void *data
)
4314 struct thin_c
*tc
= ti
->private;
4315 struct pool
*pool
= tc
->pool
;
4318 * We can't call dm_pool_get_data_dev_size() since that blocks. So
4319 * we follow a more convoluted path through to the pool's target.
4322 return 0; /* nothing is bound */
4324 blocks
= pool
->ti
->len
;
4325 (void) sector_div(blocks
, pool
->sectors_per_block
);
4327 return fn(ti
, tc
->pool_dev
, 0, pool
->sectors_per_block
* blocks
, data
);
4332 static void thin_io_hints(struct dm_target
*ti
, struct queue_limits
*limits
)
4334 struct thin_c
*tc
= ti
->private;
4335 struct pool
*pool
= tc
->pool
;
4337 limits
->discard_granularity
= pool
->sectors_per_block
<< SECTOR_SHIFT
;
4338 limits
->max_discard_sectors
= 2048 * 1024 * 16; /* 16G */
4341 static struct target_type thin_target
= {
4343 .version
= {1, 16, 0},
4344 .module
= THIS_MODULE
,
4348 .end_io
= thin_endio
,
4349 .preresume
= thin_preresume
,
4350 .presuspend
= thin_presuspend
,
4351 .postsuspend
= thin_postsuspend
,
4352 .status
= thin_status
,
4353 .merge
= thin_merge
,
4354 .iterate_devices
= thin_iterate_devices
,
4355 .io_hints
= thin_io_hints
,
4358 /*----------------------------------------------------------------*/
4360 static int __init
dm_thin_init(void)
4366 r
= dm_register_target(&thin_target
);
4370 r
= dm_register_target(&pool_target
);
4372 goto bad_pool_target
;
4376 _new_mapping_cache
= KMEM_CACHE(dm_thin_new_mapping
, 0);
4377 if (!_new_mapping_cache
)
4378 goto bad_new_mapping_cache
;
4382 bad_new_mapping_cache
:
4383 dm_unregister_target(&pool_target
);
4385 dm_unregister_target(&thin_target
);
4390 static void dm_thin_exit(void)
4392 dm_unregister_target(&thin_target
);
4393 dm_unregister_target(&pool_target
);
4395 kmem_cache_destroy(_new_mapping_cache
);
4398 module_init(dm_thin_init
);
4399 module_exit(dm_thin_exit
);
4401 module_param_named(no_space_timeout
, no_space_timeout_secs
, uint
, S_IRUGO
| S_IWUSR
);
4402 MODULE_PARM_DESC(no_space_timeout
, "Out of data space queue IO timeout in seconds");
4404 MODULE_DESCRIPTION(DM_NAME
" thin provisioning target");
4405 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
4406 MODULE_LICENSE("GPL");