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(struct pool
*pool
)
674 list_for_each_entry_rcu(tc
, &pool
->active_thins
, list
)
675 error_thin_bio_list(tc
, &tc
->retry_on_resume_list
, -EIO
);
680 * This section of code contains the logic for processing a thin device's IO.
681 * Much of the code depends on pool object resources (lists, workqueues, etc)
682 * but most is exclusively called from the thin target rather than the thin-pool
686 static dm_block_t
get_bio_block(struct thin_c
*tc
, struct bio
*bio
)
688 struct pool
*pool
= tc
->pool
;
689 sector_t block_nr
= bio
->bi_iter
.bi_sector
;
691 if (block_size_is_power_of_two(pool
))
692 block_nr
>>= pool
->sectors_per_block_shift
;
694 (void) sector_div(block_nr
, pool
->sectors_per_block
);
700 * Returns the _complete_ blocks that this bio covers.
702 static void get_bio_block_range(struct thin_c
*tc
, struct bio
*bio
,
703 dm_block_t
*begin
, dm_block_t
*end
)
705 struct pool
*pool
= tc
->pool
;
706 sector_t b
= bio
->bi_iter
.bi_sector
;
707 sector_t e
= b
+ (bio
->bi_iter
.bi_size
>> SECTOR_SHIFT
);
709 b
+= pool
->sectors_per_block
- 1ull; /* so we round up */
711 if (block_size_is_power_of_two(pool
)) {
712 b
>>= pool
->sectors_per_block_shift
;
713 e
>>= pool
->sectors_per_block_shift
;
715 (void) sector_div(b
, pool
->sectors_per_block
);
716 (void) sector_div(e
, pool
->sectors_per_block
);
720 /* Can happen if the bio is within a single block. */
727 static void remap(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
)
729 struct pool
*pool
= tc
->pool
;
730 sector_t bi_sector
= bio
->bi_iter
.bi_sector
;
732 bio
->bi_bdev
= tc
->pool_dev
->bdev
;
733 if (block_size_is_power_of_two(pool
))
734 bio
->bi_iter
.bi_sector
=
735 (block
<< pool
->sectors_per_block_shift
) |
736 (bi_sector
& (pool
->sectors_per_block
- 1));
738 bio
->bi_iter
.bi_sector
= (block
* pool
->sectors_per_block
) +
739 sector_div(bi_sector
, pool
->sectors_per_block
);
742 static void remap_to_origin(struct thin_c
*tc
, struct bio
*bio
)
744 bio
->bi_bdev
= tc
->origin_dev
->bdev
;
747 static int bio_triggers_commit(struct thin_c
*tc
, struct bio
*bio
)
749 return (bio
->bi_rw
& (REQ_FLUSH
| REQ_FUA
)) &&
750 dm_thin_changed_this_transaction(tc
->td
);
753 static void inc_all_io_entry(struct pool
*pool
, struct bio
*bio
)
755 struct dm_thin_endio_hook
*h
;
757 if (bio
->bi_rw
& REQ_DISCARD
)
760 h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
761 h
->all_io_entry
= dm_deferred_entry_inc(pool
->all_io_ds
);
764 static void issue(struct thin_c
*tc
, struct bio
*bio
)
766 struct pool
*pool
= tc
->pool
;
769 if (!bio_triggers_commit(tc
, bio
)) {
770 generic_make_request(bio
);
775 * Complete bio with an error if earlier I/O caused changes to
776 * the metadata that can't be committed e.g, due to I/O errors
777 * on the metadata device.
779 if (dm_thin_aborted_changes(tc
->td
)) {
785 * Batch together any bios that trigger commits and then issue a
786 * single commit for them in process_deferred_bios().
788 spin_lock_irqsave(&pool
->lock
, flags
);
789 bio_list_add(&pool
->deferred_flush_bios
, bio
);
790 spin_unlock_irqrestore(&pool
->lock
, flags
);
793 static void remap_to_origin_and_issue(struct thin_c
*tc
, struct bio
*bio
)
795 remap_to_origin(tc
, bio
);
799 static void remap_and_issue(struct thin_c
*tc
, struct bio
*bio
,
802 remap(tc
, bio
, block
);
806 /*----------------------------------------------------------------*/
809 * Bio endio functions.
811 struct dm_thin_new_mapping
{
812 struct list_head list
;
818 * Track quiescing, copying and zeroing preparation actions. When this
819 * counter hits zero the block is prepared and can be inserted into the
822 atomic_t prepare_actions
;
826 dm_block_t virt_begin
, virt_end
;
827 dm_block_t data_block
;
828 struct dm_bio_prison_cell
*cell
;
831 * If the bio covers the whole area of a block then we can avoid
832 * zeroing or copying. Instead this bio is hooked. The bio will
833 * still be in the cell, so care has to be taken to avoid issuing
837 bio_end_io_t
*saved_bi_end_io
;
840 static void __complete_mapping_preparation(struct dm_thin_new_mapping
*m
)
842 struct pool
*pool
= m
->tc
->pool
;
844 if (atomic_dec_and_test(&m
->prepare_actions
)) {
845 list_add_tail(&m
->list
, &pool
->prepared_mappings
);
850 static void complete_mapping_preparation(struct dm_thin_new_mapping
*m
)
853 struct pool
*pool
= m
->tc
->pool
;
855 spin_lock_irqsave(&pool
->lock
, flags
);
856 __complete_mapping_preparation(m
);
857 spin_unlock_irqrestore(&pool
->lock
, flags
);
860 static void copy_complete(int read_err
, unsigned long write_err
, void *context
)
862 struct dm_thin_new_mapping
*m
= context
;
864 m
->err
= read_err
|| write_err
? -EIO
: 0;
865 complete_mapping_preparation(m
);
868 static void overwrite_endio(struct bio
*bio
, int err
)
870 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
871 struct dm_thin_new_mapping
*m
= h
->overwrite_mapping
;
873 bio
->bi_end_io
= m
->saved_bi_end_io
;
876 complete_mapping_preparation(m
);
879 /*----------------------------------------------------------------*/
886 * Prepared mapping jobs.
890 * This sends the bios in the cell, except the original holder, back
891 * to the deferred_bios list.
893 static void cell_defer_no_holder(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
895 struct pool
*pool
= tc
->pool
;
898 spin_lock_irqsave(&tc
->lock
, flags
);
899 cell_release_no_holder(pool
, cell
, &tc
->deferred_bio_list
);
900 spin_unlock_irqrestore(&tc
->lock
, flags
);
905 static void thin_defer_bio(struct thin_c
*tc
, struct bio
*bio
);
909 struct bio_list defer_bios
;
910 struct bio_list issue_bios
;
913 static void __inc_remap_and_issue_cell(void *context
,
914 struct dm_bio_prison_cell
*cell
)
916 struct remap_info
*info
= context
;
919 while ((bio
= bio_list_pop(&cell
->bios
))) {
920 if (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
))
921 bio_list_add(&info
->defer_bios
, bio
);
923 inc_all_io_entry(info
->tc
->pool
, bio
);
926 * We can't issue the bios with the bio prison lock
927 * held, so we add them to a list to issue on
928 * return from this function.
930 bio_list_add(&info
->issue_bios
, bio
);
935 static void inc_remap_and_issue_cell(struct thin_c
*tc
,
936 struct dm_bio_prison_cell
*cell
,
940 struct remap_info info
;
943 bio_list_init(&info
.defer_bios
);
944 bio_list_init(&info
.issue_bios
);
947 * We have to be careful to inc any bios we're about to issue
948 * before the cell is released, and avoid a race with new bios
949 * being added to the cell.
951 cell_visit_release(tc
->pool
, __inc_remap_and_issue_cell
,
954 while ((bio
= bio_list_pop(&info
.defer_bios
)))
955 thin_defer_bio(tc
, bio
);
957 while ((bio
= bio_list_pop(&info
.issue_bios
)))
958 remap_and_issue(info
.tc
, bio
, block
);
961 static void process_prepared_mapping_fail(struct dm_thin_new_mapping
*m
)
963 cell_error(m
->tc
->pool
, m
->cell
);
965 mempool_free(m
, m
->tc
->pool
->mapping_pool
);
968 static void process_prepared_mapping(struct dm_thin_new_mapping
*m
)
970 struct thin_c
*tc
= m
->tc
;
971 struct pool
*pool
= tc
->pool
;
972 struct bio
*bio
= m
->bio
;
976 cell_error(pool
, m
->cell
);
981 * Commit the prepared block into the mapping btree.
982 * Any I/O for this block arriving after this point will get
983 * remapped to it directly.
985 r
= dm_thin_insert_block(tc
->td
, m
->virt_begin
, m
->data_block
);
987 metadata_operation_failed(pool
, "dm_thin_insert_block", r
);
988 cell_error(pool
, m
->cell
);
993 * Release any bios held while the block was being provisioned.
994 * If we are processing a write bio that completely covers the block,
995 * we already processed it so can ignore it now when processing
996 * the bios in the cell.
999 inc_remap_and_issue_cell(tc
, m
->cell
, m
->data_block
);
1002 inc_all_io_entry(tc
->pool
, m
->cell
->holder
);
1003 remap_and_issue(tc
, m
->cell
->holder
, m
->data_block
);
1004 inc_remap_and_issue_cell(tc
, m
->cell
, m
->data_block
);
1009 mempool_free(m
, pool
->mapping_pool
);
1012 /*----------------------------------------------------------------*/
1014 static void free_discard_mapping(struct dm_thin_new_mapping
*m
)
1016 struct thin_c
*tc
= m
->tc
;
1018 cell_defer_no_holder(tc
, m
->cell
);
1019 mempool_free(m
, tc
->pool
->mapping_pool
);
1022 static void process_prepared_discard_fail(struct dm_thin_new_mapping
*m
)
1024 bio_io_error(m
->bio
);
1025 free_discard_mapping(m
);
1028 static void process_prepared_discard_success(struct dm_thin_new_mapping
*m
)
1030 bio_endio(m
->bio
, 0);
1031 free_discard_mapping(m
);
1034 static void process_prepared_discard_no_passdown(struct dm_thin_new_mapping
*m
)
1037 struct thin_c
*tc
= m
->tc
;
1039 r
= dm_thin_remove_range(tc
->td
, m
->cell
->key
.block_begin
, m
->cell
->key
.block_end
);
1041 metadata_operation_failed(tc
->pool
, "dm_thin_remove_range", r
);
1042 bio_io_error(m
->bio
);
1044 bio_endio(m
->bio
, 0);
1046 cell_defer_no_holder(tc
, m
->cell
);
1047 mempool_free(m
, tc
->pool
->mapping_pool
);
1050 static int passdown_double_checking_shared_status(struct dm_thin_new_mapping
*m
)
1053 * We've already unmapped this range of blocks, but before we
1054 * passdown we have to check that these blocks are now unused.
1058 struct thin_c
*tc
= m
->tc
;
1059 struct pool
*pool
= tc
->pool
;
1060 dm_block_t b
= m
->data_block
, e
, end
= m
->data_block
+ m
->virt_end
- m
->virt_begin
;
1063 /* find start of unmapped run */
1064 for (; b
< end
; b
++) {
1065 r
= dm_pool_block_is_used(pool
->pmd
, b
, &used
);
1076 /* find end of run */
1077 for (e
= b
+ 1; e
!= end
; e
++) {
1078 r
= dm_pool_block_is_used(pool
->pmd
, e
, &used
);
1086 r
= issue_discard(tc
, b
, e
, m
->bio
);
1096 static void process_prepared_discard_passdown(struct dm_thin_new_mapping
*m
)
1099 struct thin_c
*tc
= m
->tc
;
1100 struct pool
*pool
= tc
->pool
;
1102 r
= dm_thin_remove_range(tc
->td
, m
->virt_begin
, m
->virt_end
);
1104 metadata_operation_failed(pool
, "dm_thin_remove_range", r
);
1106 else if (m
->maybe_shared
)
1107 r
= passdown_double_checking_shared_status(m
);
1109 r
= issue_discard(tc
, m
->data_block
, m
->data_block
+ (m
->virt_end
- m
->virt_begin
), m
->bio
);
1112 * Even if r is set, there could be sub discards in flight that we
1115 bio_endio(m
->bio
, r
);
1116 cell_defer_no_holder(tc
, m
->cell
);
1117 mempool_free(m
, pool
->mapping_pool
);
1120 static void process_prepared(struct pool
*pool
, struct list_head
*head
,
1121 process_mapping_fn
*fn
)
1123 unsigned long flags
;
1124 struct list_head maps
;
1125 struct dm_thin_new_mapping
*m
, *tmp
;
1127 INIT_LIST_HEAD(&maps
);
1128 spin_lock_irqsave(&pool
->lock
, flags
);
1129 list_splice_init(head
, &maps
);
1130 spin_unlock_irqrestore(&pool
->lock
, flags
);
1132 list_for_each_entry_safe(m
, tmp
, &maps
, list
)
1137 * Deferred bio jobs.
1139 static int io_overlaps_block(struct pool
*pool
, struct bio
*bio
)
1141 return bio
->bi_iter
.bi_size
==
1142 (pool
->sectors_per_block
<< SECTOR_SHIFT
);
1145 static int io_overwrites_block(struct pool
*pool
, struct bio
*bio
)
1147 return (bio_data_dir(bio
) == WRITE
) &&
1148 io_overlaps_block(pool
, bio
);
1151 static void save_and_set_endio(struct bio
*bio
, bio_end_io_t
**save
,
1154 *save
= bio
->bi_end_io
;
1155 bio
->bi_end_io
= fn
;
1158 static int ensure_next_mapping(struct pool
*pool
)
1160 if (pool
->next_mapping
)
1163 pool
->next_mapping
= mempool_alloc(pool
->mapping_pool
, GFP_ATOMIC
);
1165 return pool
->next_mapping
? 0 : -ENOMEM
;
1168 static struct dm_thin_new_mapping
*get_next_mapping(struct pool
*pool
)
1170 struct dm_thin_new_mapping
*m
= pool
->next_mapping
;
1172 BUG_ON(!pool
->next_mapping
);
1174 memset(m
, 0, sizeof(struct dm_thin_new_mapping
));
1175 INIT_LIST_HEAD(&m
->list
);
1178 pool
->next_mapping
= NULL
;
1183 static void ll_zero(struct thin_c
*tc
, struct dm_thin_new_mapping
*m
,
1184 sector_t begin
, sector_t end
)
1187 struct dm_io_region to
;
1189 to
.bdev
= tc
->pool_dev
->bdev
;
1191 to
.count
= end
- begin
;
1193 r
= dm_kcopyd_zero(tc
->pool
->copier
, 1, &to
, 0, copy_complete
, m
);
1195 DMERR_LIMIT("dm_kcopyd_zero() failed");
1196 copy_complete(1, 1, m
);
1200 static void remap_and_issue_overwrite(struct thin_c
*tc
, struct bio
*bio
,
1201 dm_block_t data_begin
,
1202 struct dm_thin_new_mapping
*m
)
1204 struct pool
*pool
= tc
->pool
;
1205 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1207 h
->overwrite_mapping
= m
;
1209 save_and_set_endio(bio
, &m
->saved_bi_end_io
, overwrite_endio
);
1210 inc_all_io_entry(pool
, bio
);
1211 remap_and_issue(tc
, bio
, data_begin
);
1215 * A partial copy also needs to zero the uncopied region.
1217 static void schedule_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1218 struct dm_dev
*origin
, dm_block_t data_origin
,
1219 dm_block_t data_dest
,
1220 struct dm_bio_prison_cell
*cell
, struct bio
*bio
,
1224 struct pool
*pool
= tc
->pool
;
1225 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1228 m
->virt_begin
= virt_block
;
1229 m
->virt_end
= virt_block
+ 1u;
1230 m
->data_block
= data_dest
;
1234 * quiesce action + copy action + an extra reference held for the
1235 * duration of this function (we may need to inc later for a
1238 atomic_set(&m
->prepare_actions
, 3);
1240 if (!dm_deferred_set_add_work(pool
->shared_read_ds
, &m
->list
))
1241 complete_mapping_preparation(m
); /* already quiesced */
1244 * IO to pool_dev remaps to the pool target's data_dev.
1246 * If the whole block of data is being overwritten, we can issue the
1247 * bio immediately. Otherwise we use kcopyd to clone the data first.
1249 if (io_overwrites_block(pool
, bio
))
1250 remap_and_issue_overwrite(tc
, bio
, data_dest
, m
);
1252 struct dm_io_region from
, to
;
1254 from
.bdev
= origin
->bdev
;
1255 from
.sector
= data_origin
* pool
->sectors_per_block
;
1258 to
.bdev
= tc
->pool_dev
->bdev
;
1259 to
.sector
= data_dest
* pool
->sectors_per_block
;
1262 r
= dm_kcopyd_copy(pool
->copier
, &from
, 1, &to
,
1263 0, copy_complete
, m
);
1265 DMERR_LIMIT("dm_kcopyd_copy() failed");
1266 copy_complete(1, 1, m
);
1269 * We allow the zero to be issued, to simplify the
1270 * error path. Otherwise we'd need to start
1271 * worrying about decrementing the prepare_actions
1277 * Do we need to zero a tail region?
1279 if (len
< pool
->sectors_per_block
&& pool
->pf
.zero_new_blocks
) {
1280 atomic_inc(&m
->prepare_actions
);
1282 data_dest
* pool
->sectors_per_block
+ len
,
1283 (data_dest
+ 1) * pool
->sectors_per_block
);
1287 complete_mapping_preparation(m
); /* drop our ref */
1290 static void schedule_internal_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1291 dm_block_t data_origin
, dm_block_t data_dest
,
1292 struct dm_bio_prison_cell
*cell
, struct bio
*bio
)
1294 schedule_copy(tc
, virt_block
, tc
->pool_dev
,
1295 data_origin
, data_dest
, cell
, bio
,
1296 tc
->pool
->sectors_per_block
);
1299 static void schedule_zero(struct thin_c
*tc
, dm_block_t virt_block
,
1300 dm_block_t data_block
, struct dm_bio_prison_cell
*cell
,
1303 struct pool
*pool
= tc
->pool
;
1304 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1306 atomic_set(&m
->prepare_actions
, 1); /* no need to quiesce */
1308 m
->virt_begin
= virt_block
;
1309 m
->virt_end
= virt_block
+ 1u;
1310 m
->data_block
= data_block
;
1314 * If the whole block of data is being overwritten or we are not
1315 * zeroing pre-existing data, we can issue the bio immediately.
1316 * Otherwise we use kcopyd to zero the data first.
1318 if (pool
->pf
.zero_new_blocks
) {
1319 if (io_overwrites_block(pool
, bio
))
1320 remap_and_issue_overwrite(tc
, bio
, data_block
, m
);
1322 ll_zero(tc
, m
, data_block
* pool
->sectors_per_block
,
1323 (data_block
+ 1) * pool
->sectors_per_block
);
1325 process_prepared_mapping(m
);
1328 static void schedule_external_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1329 dm_block_t data_dest
,
1330 struct dm_bio_prison_cell
*cell
, struct bio
*bio
)
1332 struct pool
*pool
= tc
->pool
;
1333 sector_t virt_block_begin
= virt_block
* pool
->sectors_per_block
;
1334 sector_t virt_block_end
= (virt_block
+ 1) * pool
->sectors_per_block
;
1336 if (virt_block_end
<= tc
->origin_size
)
1337 schedule_copy(tc
, virt_block
, tc
->origin_dev
,
1338 virt_block
, data_dest
, cell
, bio
,
1339 pool
->sectors_per_block
);
1341 else if (virt_block_begin
< tc
->origin_size
)
1342 schedule_copy(tc
, virt_block
, tc
->origin_dev
,
1343 virt_block
, data_dest
, cell
, bio
,
1344 tc
->origin_size
- virt_block_begin
);
1347 schedule_zero(tc
, virt_block
, data_dest
, cell
, bio
);
1350 static void set_pool_mode(struct pool
*pool
, enum pool_mode new_mode
);
1352 static void check_for_space(struct pool
*pool
)
1357 if (get_pool_mode(pool
) != PM_OUT_OF_DATA_SPACE
)
1360 r
= dm_pool_get_free_block_count(pool
->pmd
, &nr_free
);
1365 set_pool_mode(pool
, PM_WRITE
);
1369 * A non-zero return indicates read_only or fail_io mode.
1370 * Many callers don't care about the return value.
1372 static int commit(struct pool
*pool
)
1376 if (get_pool_mode(pool
) >= PM_READ_ONLY
)
1379 r
= dm_pool_commit_metadata(pool
->pmd
);
1381 metadata_operation_failed(pool
, "dm_pool_commit_metadata", r
);
1383 check_for_space(pool
);
1388 static void check_low_water_mark(struct pool
*pool
, dm_block_t free_blocks
)
1390 unsigned long flags
;
1392 if (free_blocks
<= pool
->low_water_blocks
&& !pool
->low_water_triggered
) {
1393 DMWARN("%s: reached low water mark for data device: sending event.",
1394 dm_device_name(pool
->pool_md
));
1395 spin_lock_irqsave(&pool
->lock
, flags
);
1396 pool
->low_water_triggered
= true;
1397 spin_unlock_irqrestore(&pool
->lock
, flags
);
1398 dm_table_event(pool
->ti
->table
);
1402 static int alloc_data_block(struct thin_c
*tc
, dm_block_t
*result
)
1405 dm_block_t free_blocks
;
1406 struct pool
*pool
= tc
->pool
;
1408 if (WARN_ON(get_pool_mode(pool
) != PM_WRITE
))
1411 r
= dm_pool_get_free_block_count(pool
->pmd
, &free_blocks
);
1413 metadata_operation_failed(pool
, "dm_pool_get_free_block_count", r
);
1417 check_low_water_mark(pool
, free_blocks
);
1421 * Try to commit to see if that will free up some
1428 r
= dm_pool_get_free_block_count(pool
->pmd
, &free_blocks
);
1430 metadata_operation_failed(pool
, "dm_pool_get_free_block_count", r
);
1435 set_pool_mode(pool
, PM_OUT_OF_DATA_SPACE
);
1440 r
= dm_pool_alloc_data_block(pool
->pmd
, result
);
1442 metadata_operation_failed(pool
, "dm_pool_alloc_data_block", r
);
1450 * If we have run out of space, queue bios until the device is
1451 * resumed, presumably after having been reloaded with more space.
1453 static void retry_on_resume(struct bio
*bio
)
1455 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1456 struct thin_c
*tc
= h
->tc
;
1457 unsigned long flags
;
1459 spin_lock_irqsave(&tc
->lock
, flags
);
1460 bio_list_add(&tc
->retry_on_resume_list
, bio
);
1461 spin_unlock_irqrestore(&tc
->lock
, flags
);
1464 static int should_error_unserviceable_bio(struct pool
*pool
)
1466 enum pool_mode m
= get_pool_mode(pool
);
1470 /* Shouldn't get here */
1471 DMERR_LIMIT("bio unserviceable, yet pool is in PM_WRITE mode");
1474 case PM_OUT_OF_DATA_SPACE
:
1475 return pool
->pf
.error_if_no_space
? -ENOSPC
: 0;
1481 /* Shouldn't get here */
1482 DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode");
1487 static void handle_unserviceable_bio(struct pool
*pool
, struct bio
*bio
)
1489 int error
= should_error_unserviceable_bio(pool
);
1492 bio_endio(bio
, error
);
1494 retry_on_resume(bio
);
1497 static void retry_bios_on_resume(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
1500 struct bio_list bios
;
1503 error
= should_error_unserviceable_bio(pool
);
1505 cell_error_with_code(pool
, cell
, error
);
1509 bio_list_init(&bios
);
1510 cell_release(pool
, cell
, &bios
);
1512 while ((bio
= bio_list_pop(&bios
)))
1513 retry_on_resume(bio
);
1516 static void process_discard_cell_no_passdown(struct thin_c
*tc
,
1517 struct dm_bio_prison_cell
*virt_cell
)
1519 struct pool
*pool
= tc
->pool
;
1520 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1523 * We don't need to lock the data blocks, since there's no
1524 * passdown. We only lock data blocks for allocation and breaking sharing.
1527 m
->virt_begin
= virt_cell
->key
.block_begin
;
1528 m
->virt_end
= virt_cell
->key
.block_end
;
1529 m
->cell
= virt_cell
;
1530 m
->bio
= virt_cell
->holder
;
1532 if (!dm_deferred_set_add_work(pool
->all_io_ds
, &m
->list
))
1533 pool
->process_prepared_discard(m
);
1537 * FIXME: DM local hack to defer parent bios's end_io until we
1538 * _know_ all chained sub range discard bios have completed.
1539 * Will go away once late bio splitting lands upstream!
1541 static inline void __bio_inc_remaining(struct bio
*bio
)
1543 bio
->bi_flags
|= (1 << BIO_CHAIN
);
1544 smp_mb__before_atomic();
1545 atomic_inc(&bio
->__bi_remaining
);
1548 static void break_up_discard_bio(struct thin_c
*tc
, dm_block_t begin
, dm_block_t end
,
1551 struct pool
*pool
= tc
->pool
;
1555 struct dm_cell_key data_key
;
1556 struct dm_bio_prison_cell
*data_cell
;
1557 struct dm_thin_new_mapping
*m
;
1558 dm_block_t virt_begin
, virt_end
, data_begin
;
1560 while (begin
!= end
) {
1561 r
= ensure_next_mapping(pool
);
1563 /* we did our best */
1566 r
= dm_thin_find_mapped_range(tc
->td
, begin
, end
, &virt_begin
, &virt_end
,
1567 &data_begin
, &maybe_shared
);
1570 * Silently fail, letting any mappings we've
1575 build_key(tc
->td
, PHYSICAL
, data_begin
, data_begin
+ (virt_end
- virt_begin
), &data_key
);
1576 if (bio_detain(tc
->pool
, &data_key
, NULL
, &data_cell
)) {
1577 /* contention, we'll give up with this range */
1583 * IO may still be going to the destination block. We must
1584 * quiesce before we can do the removal.
1586 m
= get_next_mapping(pool
);
1588 m
->maybe_shared
= maybe_shared
;
1589 m
->virt_begin
= virt_begin
;
1590 m
->virt_end
= virt_end
;
1591 m
->data_block
= data_begin
;
1592 m
->cell
= data_cell
;
1596 * The parent bio must not complete before sub discard bios are
1597 * chained to it (see __blkdev_issue_discard_async's bio_chain)!
1599 * This per-mapping bi_remaining increment is paired with
1600 * the implicit decrement that occurs via bio_endio() in
1601 * process_prepared_discard_{passdown,no_passdown}.
1603 __bio_inc_remaining(bio
);
1604 if (!dm_deferred_set_add_work(pool
->all_io_ds
, &m
->list
))
1605 pool
->process_prepared_discard(m
);
1611 static void process_discard_cell_passdown(struct thin_c
*tc
, struct dm_bio_prison_cell
*virt_cell
)
1613 struct bio
*bio
= virt_cell
->holder
;
1614 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1617 * The virt_cell will only get freed once the origin bio completes.
1618 * This means it will remain locked while all the individual
1619 * passdown bios are in flight.
1621 h
->cell
= virt_cell
;
1622 break_up_discard_bio(tc
, virt_cell
->key
.block_begin
, virt_cell
->key
.block_end
, bio
);
1625 * We complete the bio now, knowing that the bi_remaining field
1626 * will prevent completion until the sub range discards have
1632 static void process_discard_bio(struct thin_c
*tc
, struct bio
*bio
)
1634 dm_block_t begin
, end
;
1635 struct dm_cell_key virt_key
;
1636 struct dm_bio_prison_cell
*virt_cell
;
1638 get_bio_block_range(tc
, bio
, &begin
, &end
);
1641 * The discard covers less than a block.
1647 build_key(tc
->td
, VIRTUAL
, begin
, end
, &virt_key
);
1648 if (bio_detain(tc
->pool
, &virt_key
, bio
, &virt_cell
))
1650 * Potential starvation issue: We're relying on the
1651 * fs/application being well behaved, and not trying to
1652 * send IO to a region at the same time as discarding it.
1653 * If they do this persistently then it's possible this
1654 * cell will never be granted.
1658 tc
->pool
->process_discard_cell(tc
, virt_cell
);
1661 static void break_sharing(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
,
1662 struct dm_cell_key
*key
,
1663 struct dm_thin_lookup_result
*lookup_result
,
1664 struct dm_bio_prison_cell
*cell
)
1667 dm_block_t data_block
;
1668 struct pool
*pool
= tc
->pool
;
1670 r
= alloc_data_block(tc
, &data_block
);
1673 schedule_internal_copy(tc
, block
, lookup_result
->block
,
1674 data_block
, cell
, bio
);
1678 retry_bios_on_resume(pool
, cell
);
1682 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1684 cell_error(pool
, cell
);
1689 static void __remap_and_issue_shared_cell(void *context
,
1690 struct dm_bio_prison_cell
*cell
)
1692 struct remap_info
*info
= context
;
1695 while ((bio
= bio_list_pop(&cell
->bios
))) {
1696 if ((bio_data_dir(bio
) == WRITE
) ||
1697 (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
)))
1698 bio_list_add(&info
->defer_bios
, bio
);
1700 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));;
1702 h
->shared_read_entry
= dm_deferred_entry_inc(info
->tc
->pool
->shared_read_ds
);
1703 inc_all_io_entry(info
->tc
->pool
, bio
);
1704 bio_list_add(&info
->issue_bios
, bio
);
1709 static void remap_and_issue_shared_cell(struct thin_c
*tc
,
1710 struct dm_bio_prison_cell
*cell
,
1714 struct remap_info info
;
1717 bio_list_init(&info
.defer_bios
);
1718 bio_list_init(&info
.issue_bios
);
1720 cell_visit_release(tc
->pool
, __remap_and_issue_shared_cell
,
1723 while ((bio
= bio_list_pop(&info
.defer_bios
)))
1724 thin_defer_bio(tc
, bio
);
1726 while ((bio
= bio_list_pop(&info
.issue_bios
)))
1727 remap_and_issue(tc
, bio
, block
);
1730 static void process_shared_bio(struct thin_c
*tc
, struct bio
*bio
,
1732 struct dm_thin_lookup_result
*lookup_result
,
1733 struct dm_bio_prison_cell
*virt_cell
)
1735 struct dm_bio_prison_cell
*data_cell
;
1736 struct pool
*pool
= tc
->pool
;
1737 struct dm_cell_key key
;
1740 * If cell is already occupied, then sharing is already in the process
1741 * of being broken so we have nothing further to do here.
1743 build_data_key(tc
->td
, lookup_result
->block
, &key
);
1744 if (bio_detain(pool
, &key
, bio
, &data_cell
)) {
1745 cell_defer_no_holder(tc
, virt_cell
);
1749 if (bio_data_dir(bio
) == WRITE
&& bio
->bi_iter
.bi_size
) {
1750 break_sharing(tc
, bio
, block
, &key
, lookup_result
, data_cell
);
1751 cell_defer_no_holder(tc
, virt_cell
);
1753 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1755 h
->shared_read_entry
= dm_deferred_entry_inc(pool
->shared_read_ds
);
1756 inc_all_io_entry(pool
, bio
);
1757 remap_and_issue(tc
, bio
, lookup_result
->block
);
1759 remap_and_issue_shared_cell(tc
, data_cell
, lookup_result
->block
);
1760 remap_and_issue_shared_cell(tc
, virt_cell
, lookup_result
->block
);
1764 static void provision_block(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
,
1765 struct dm_bio_prison_cell
*cell
)
1768 dm_block_t data_block
;
1769 struct pool
*pool
= tc
->pool
;
1772 * Remap empty bios (flushes) immediately, without provisioning.
1774 if (!bio
->bi_iter
.bi_size
) {
1775 inc_all_io_entry(pool
, bio
);
1776 cell_defer_no_holder(tc
, cell
);
1778 remap_and_issue(tc
, bio
, 0);
1783 * Fill read bios with zeroes and complete them immediately.
1785 if (bio_data_dir(bio
) == READ
) {
1787 cell_defer_no_holder(tc
, cell
);
1792 r
= alloc_data_block(tc
, &data_block
);
1796 schedule_external_copy(tc
, block
, data_block
, cell
, bio
);
1798 schedule_zero(tc
, block
, data_block
, cell
, bio
);
1802 retry_bios_on_resume(pool
, cell
);
1806 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1808 cell_error(pool
, cell
);
1813 static void process_cell(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1816 struct pool
*pool
= tc
->pool
;
1817 struct bio
*bio
= cell
->holder
;
1818 dm_block_t block
= get_bio_block(tc
, bio
);
1819 struct dm_thin_lookup_result lookup_result
;
1821 if (tc
->requeue_mode
) {
1822 cell_requeue(pool
, cell
);
1826 r
= dm_thin_find_block(tc
->td
, block
, 1, &lookup_result
);
1829 if (lookup_result
.shared
)
1830 process_shared_bio(tc
, bio
, block
, &lookup_result
, cell
);
1832 inc_all_io_entry(pool
, bio
);
1833 remap_and_issue(tc
, bio
, lookup_result
.block
);
1834 inc_remap_and_issue_cell(tc
, cell
, lookup_result
.block
);
1839 if (bio_data_dir(bio
) == READ
&& tc
->origin_dev
) {
1840 inc_all_io_entry(pool
, bio
);
1841 cell_defer_no_holder(tc
, cell
);
1843 if (bio_end_sector(bio
) <= tc
->origin_size
)
1844 remap_to_origin_and_issue(tc
, bio
);
1846 else if (bio
->bi_iter
.bi_sector
< tc
->origin_size
) {
1848 bio
->bi_iter
.bi_size
= (tc
->origin_size
- bio
->bi_iter
.bi_sector
) << SECTOR_SHIFT
;
1849 remap_to_origin_and_issue(tc
, bio
);
1856 provision_block(tc
, bio
, block
, cell
);
1860 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1862 cell_defer_no_holder(tc
, cell
);
1868 static void process_bio(struct thin_c
*tc
, struct bio
*bio
)
1870 struct pool
*pool
= tc
->pool
;
1871 dm_block_t block
= get_bio_block(tc
, bio
);
1872 struct dm_bio_prison_cell
*cell
;
1873 struct dm_cell_key key
;
1876 * If cell is already occupied, then the block is already
1877 * being provisioned so we have nothing further to do here.
1879 build_virtual_key(tc
->td
, block
, &key
);
1880 if (bio_detain(pool
, &key
, bio
, &cell
))
1883 process_cell(tc
, cell
);
1886 static void __process_bio_read_only(struct thin_c
*tc
, struct bio
*bio
,
1887 struct dm_bio_prison_cell
*cell
)
1890 int rw
= bio_data_dir(bio
);
1891 dm_block_t block
= get_bio_block(tc
, bio
);
1892 struct dm_thin_lookup_result lookup_result
;
1894 r
= dm_thin_find_block(tc
->td
, block
, 1, &lookup_result
);
1897 if (lookup_result
.shared
&& (rw
== WRITE
) && bio
->bi_iter
.bi_size
) {
1898 handle_unserviceable_bio(tc
->pool
, bio
);
1900 cell_defer_no_holder(tc
, cell
);
1902 inc_all_io_entry(tc
->pool
, bio
);
1903 remap_and_issue(tc
, bio
, lookup_result
.block
);
1905 inc_remap_and_issue_cell(tc
, cell
, lookup_result
.block
);
1911 cell_defer_no_holder(tc
, cell
);
1913 handle_unserviceable_bio(tc
->pool
, bio
);
1917 if (tc
->origin_dev
) {
1918 inc_all_io_entry(tc
->pool
, bio
);
1919 remap_to_origin_and_issue(tc
, bio
);
1928 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1931 cell_defer_no_holder(tc
, cell
);
1937 static void process_bio_read_only(struct thin_c
*tc
, struct bio
*bio
)
1939 __process_bio_read_only(tc
, bio
, NULL
);
1942 static void process_cell_read_only(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1944 __process_bio_read_only(tc
, cell
->holder
, cell
);
1947 static void process_bio_success(struct thin_c
*tc
, struct bio
*bio
)
1952 static void process_bio_fail(struct thin_c
*tc
, struct bio
*bio
)
1957 static void process_cell_success(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1959 cell_success(tc
->pool
, cell
);
1962 static void process_cell_fail(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1964 cell_error(tc
->pool
, cell
);
1968 * FIXME: should we also commit due to size of transaction, measured in
1971 static int need_commit_due_to_time(struct pool
*pool
)
1973 return !time_in_range(jiffies
, pool
->last_commit_jiffies
,
1974 pool
->last_commit_jiffies
+ COMMIT_PERIOD
);
1977 #define thin_pbd(node) rb_entry((node), struct dm_thin_endio_hook, rb_node)
1978 #define thin_bio(pbd) dm_bio_from_per_bio_data((pbd), sizeof(struct dm_thin_endio_hook))
1980 static void __thin_bio_rb_add(struct thin_c
*tc
, struct bio
*bio
)
1982 struct rb_node
**rbp
, *parent
;
1983 struct dm_thin_endio_hook
*pbd
;
1984 sector_t bi_sector
= bio
->bi_iter
.bi_sector
;
1986 rbp
= &tc
->sort_bio_list
.rb_node
;
1990 pbd
= thin_pbd(parent
);
1992 if (bi_sector
< thin_bio(pbd
)->bi_iter
.bi_sector
)
1993 rbp
= &(*rbp
)->rb_left
;
1995 rbp
= &(*rbp
)->rb_right
;
1998 pbd
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1999 rb_link_node(&pbd
->rb_node
, parent
, rbp
);
2000 rb_insert_color(&pbd
->rb_node
, &tc
->sort_bio_list
);
2003 static void __extract_sorted_bios(struct thin_c
*tc
)
2005 struct rb_node
*node
;
2006 struct dm_thin_endio_hook
*pbd
;
2009 for (node
= rb_first(&tc
->sort_bio_list
); node
; node
= rb_next(node
)) {
2010 pbd
= thin_pbd(node
);
2011 bio
= thin_bio(pbd
);
2013 bio_list_add(&tc
->deferred_bio_list
, bio
);
2014 rb_erase(&pbd
->rb_node
, &tc
->sort_bio_list
);
2017 WARN_ON(!RB_EMPTY_ROOT(&tc
->sort_bio_list
));
2020 static void __sort_thin_deferred_bios(struct thin_c
*tc
)
2023 struct bio_list bios
;
2025 bio_list_init(&bios
);
2026 bio_list_merge(&bios
, &tc
->deferred_bio_list
);
2027 bio_list_init(&tc
->deferred_bio_list
);
2029 /* Sort deferred_bio_list using rb-tree */
2030 while ((bio
= bio_list_pop(&bios
)))
2031 __thin_bio_rb_add(tc
, bio
);
2034 * Transfer the sorted bios in sort_bio_list back to
2035 * deferred_bio_list to allow lockless submission of
2038 __extract_sorted_bios(tc
);
2041 static void process_thin_deferred_bios(struct thin_c
*tc
)
2043 struct pool
*pool
= tc
->pool
;
2044 unsigned long flags
;
2046 struct bio_list bios
;
2047 struct blk_plug plug
;
2050 if (tc
->requeue_mode
) {
2051 error_thin_bio_list(tc
, &tc
->deferred_bio_list
, DM_ENDIO_REQUEUE
);
2055 bio_list_init(&bios
);
2057 spin_lock_irqsave(&tc
->lock
, flags
);
2059 if (bio_list_empty(&tc
->deferred_bio_list
)) {
2060 spin_unlock_irqrestore(&tc
->lock
, flags
);
2064 __sort_thin_deferred_bios(tc
);
2066 bio_list_merge(&bios
, &tc
->deferred_bio_list
);
2067 bio_list_init(&tc
->deferred_bio_list
);
2069 spin_unlock_irqrestore(&tc
->lock
, flags
);
2071 blk_start_plug(&plug
);
2072 while ((bio
= bio_list_pop(&bios
))) {
2074 * If we've got no free new_mapping structs, and processing
2075 * this bio might require one, we pause until there are some
2076 * prepared mappings to process.
2078 if (ensure_next_mapping(pool
)) {
2079 spin_lock_irqsave(&tc
->lock
, flags
);
2080 bio_list_add(&tc
->deferred_bio_list
, bio
);
2081 bio_list_merge(&tc
->deferred_bio_list
, &bios
);
2082 spin_unlock_irqrestore(&tc
->lock
, flags
);
2086 if (bio
->bi_rw
& REQ_DISCARD
)
2087 pool
->process_discard(tc
, bio
);
2089 pool
->process_bio(tc
, bio
);
2091 if ((count
++ & 127) == 0) {
2092 throttle_work_update(&pool
->throttle
);
2093 dm_pool_issue_prefetches(pool
->pmd
);
2096 blk_finish_plug(&plug
);
2099 static int cmp_cells(const void *lhs
, const void *rhs
)
2101 struct dm_bio_prison_cell
*lhs_cell
= *((struct dm_bio_prison_cell
**) lhs
);
2102 struct dm_bio_prison_cell
*rhs_cell
= *((struct dm_bio_prison_cell
**) rhs
);
2104 BUG_ON(!lhs_cell
->holder
);
2105 BUG_ON(!rhs_cell
->holder
);
2107 if (lhs_cell
->holder
->bi_iter
.bi_sector
< rhs_cell
->holder
->bi_iter
.bi_sector
)
2110 if (lhs_cell
->holder
->bi_iter
.bi_sector
> rhs_cell
->holder
->bi_iter
.bi_sector
)
2116 static unsigned sort_cells(struct pool
*pool
, struct list_head
*cells
)
2119 struct dm_bio_prison_cell
*cell
, *tmp
;
2121 list_for_each_entry_safe(cell
, tmp
, cells
, user_list
) {
2122 if (count
>= CELL_SORT_ARRAY_SIZE
)
2125 pool
->cell_sort_array
[count
++] = cell
;
2126 list_del(&cell
->user_list
);
2129 sort(pool
->cell_sort_array
, count
, sizeof(cell
), cmp_cells
, NULL
);
2134 static void process_thin_deferred_cells(struct thin_c
*tc
)
2136 struct pool
*pool
= tc
->pool
;
2137 unsigned long flags
;
2138 struct list_head cells
;
2139 struct dm_bio_prison_cell
*cell
;
2140 unsigned i
, j
, count
;
2142 INIT_LIST_HEAD(&cells
);
2144 spin_lock_irqsave(&tc
->lock
, flags
);
2145 list_splice_init(&tc
->deferred_cells
, &cells
);
2146 spin_unlock_irqrestore(&tc
->lock
, flags
);
2148 if (list_empty(&cells
))
2152 count
= sort_cells(tc
->pool
, &cells
);
2154 for (i
= 0; i
< count
; i
++) {
2155 cell
= pool
->cell_sort_array
[i
];
2156 BUG_ON(!cell
->holder
);
2159 * If we've got no free new_mapping structs, and processing
2160 * this bio might require one, we pause until there are some
2161 * prepared mappings to process.
2163 if (ensure_next_mapping(pool
)) {
2164 for (j
= i
; j
< count
; j
++)
2165 list_add(&pool
->cell_sort_array
[j
]->user_list
, &cells
);
2167 spin_lock_irqsave(&tc
->lock
, flags
);
2168 list_splice(&cells
, &tc
->deferred_cells
);
2169 spin_unlock_irqrestore(&tc
->lock
, flags
);
2173 if (cell
->holder
->bi_rw
& REQ_DISCARD
)
2174 pool
->process_discard_cell(tc
, cell
);
2176 pool
->process_cell(tc
, cell
);
2178 } while (!list_empty(&cells
));
2181 static void thin_get(struct thin_c
*tc
);
2182 static void thin_put(struct thin_c
*tc
);
2185 * We can't hold rcu_read_lock() around code that can block. So we
2186 * find a thin with the rcu lock held; bump a refcount; then drop
2189 static struct thin_c
*get_first_thin(struct pool
*pool
)
2191 struct thin_c
*tc
= NULL
;
2194 if (!list_empty(&pool
->active_thins
)) {
2195 tc
= list_entry_rcu(pool
->active_thins
.next
, struct thin_c
, list
);
2203 static struct thin_c
*get_next_thin(struct pool
*pool
, struct thin_c
*tc
)
2205 struct thin_c
*old_tc
= tc
;
2208 list_for_each_entry_continue_rcu(tc
, &pool
->active_thins
, list
) {
2220 static void process_deferred_bios(struct pool
*pool
)
2222 unsigned long flags
;
2224 struct bio_list bios
;
2227 tc
= get_first_thin(pool
);
2229 process_thin_deferred_cells(tc
);
2230 process_thin_deferred_bios(tc
);
2231 tc
= get_next_thin(pool
, tc
);
2235 * If there are any deferred flush bios, we must commit
2236 * the metadata before issuing them.
2238 bio_list_init(&bios
);
2239 spin_lock_irqsave(&pool
->lock
, flags
);
2240 bio_list_merge(&bios
, &pool
->deferred_flush_bios
);
2241 bio_list_init(&pool
->deferred_flush_bios
);
2242 spin_unlock_irqrestore(&pool
->lock
, flags
);
2244 if (bio_list_empty(&bios
) &&
2245 !(dm_pool_changed_this_transaction(pool
->pmd
) && need_commit_due_to_time(pool
)))
2249 while ((bio
= bio_list_pop(&bios
)))
2253 pool
->last_commit_jiffies
= jiffies
;
2255 while ((bio
= bio_list_pop(&bios
)))
2256 generic_make_request(bio
);
2259 static void do_worker(struct work_struct
*ws
)
2261 struct pool
*pool
= container_of(ws
, struct pool
, worker
);
2263 throttle_work_start(&pool
->throttle
);
2264 dm_pool_issue_prefetches(pool
->pmd
);
2265 throttle_work_update(&pool
->throttle
);
2266 process_prepared(pool
, &pool
->prepared_mappings
, &pool
->process_prepared_mapping
);
2267 throttle_work_update(&pool
->throttle
);
2268 process_prepared(pool
, &pool
->prepared_discards
, &pool
->process_prepared_discard
);
2269 throttle_work_update(&pool
->throttle
);
2270 process_deferred_bios(pool
);
2271 throttle_work_complete(&pool
->throttle
);
2275 * We want to commit periodically so that not too much
2276 * unwritten data builds up.
2278 static void do_waker(struct work_struct
*ws
)
2280 struct pool
*pool
= container_of(to_delayed_work(ws
), struct pool
, waker
);
2282 queue_delayed_work(pool
->wq
, &pool
->waker
, COMMIT_PERIOD
);
2285 static void notify_of_pool_mode_change_to_oods(struct pool
*pool
);
2288 * We're holding onto IO to allow userland time to react. After the
2289 * timeout either the pool will have been resized (and thus back in
2290 * PM_WRITE mode), or we degrade to PM_OUT_OF_DATA_SPACE w/ error_if_no_space.
2292 static void do_no_space_timeout(struct work_struct
*ws
)
2294 struct pool
*pool
= container_of(to_delayed_work(ws
), struct pool
,
2297 if (get_pool_mode(pool
) == PM_OUT_OF_DATA_SPACE
&& !pool
->pf
.error_if_no_space
) {
2298 pool
->pf
.error_if_no_space
= true;
2299 notify_of_pool_mode_change_to_oods(pool
);
2300 error_retry_list(pool
);
2304 /*----------------------------------------------------------------*/
2307 struct work_struct worker
;
2308 struct completion complete
;
2311 static struct pool_work
*to_pool_work(struct work_struct
*ws
)
2313 return container_of(ws
, struct pool_work
, worker
);
2316 static void pool_work_complete(struct pool_work
*pw
)
2318 complete(&pw
->complete
);
2321 static void pool_work_wait(struct pool_work
*pw
, struct pool
*pool
,
2322 void (*fn
)(struct work_struct
*))
2324 INIT_WORK_ONSTACK(&pw
->worker
, fn
);
2325 init_completion(&pw
->complete
);
2326 queue_work(pool
->wq
, &pw
->worker
);
2327 wait_for_completion(&pw
->complete
);
2330 /*----------------------------------------------------------------*/
2332 struct noflush_work
{
2333 struct pool_work pw
;
2337 static struct noflush_work
*to_noflush(struct work_struct
*ws
)
2339 return container_of(to_pool_work(ws
), struct noflush_work
, pw
);
2342 static void do_noflush_start(struct work_struct
*ws
)
2344 struct noflush_work
*w
= to_noflush(ws
);
2345 w
->tc
->requeue_mode
= true;
2347 pool_work_complete(&w
->pw
);
2350 static void do_noflush_stop(struct work_struct
*ws
)
2352 struct noflush_work
*w
= to_noflush(ws
);
2353 w
->tc
->requeue_mode
= false;
2354 pool_work_complete(&w
->pw
);
2357 static void noflush_work(struct thin_c
*tc
, void (*fn
)(struct work_struct
*))
2359 struct noflush_work w
;
2362 pool_work_wait(&w
.pw
, tc
->pool
, fn
);
2365 /*----------------------------------------------------------------*/
2367 static enum pool_mode
get_pool_mode(struct pool
*pool
)
2369 return pool
->pf
.mode
;
2372 static void notify_of_pool_mode_change(struct pool
*pool
, const char *new_mode
)
2374 dm_table_event(pool
->ti
->table
);
2375 DMINFO("%s: switching pool to %s mode",
2376 dm_device_name(pool
->pool_md
), new_mode
);
2379 static void notify_of_pool_mode_change_to_oods(struct pool
*pool
)
2381 if (!pool
->pf
.error_if_no_space
)
2382 notify_of_pool_mode_change(pool
, "out-of-data-space (queue IO)");
2384 notify_of_pool_mode_change(pool
, "out-of-data-space (error IO)");
2387 static bool passdown_enabled(struct pool_c
*pt
)
2389 return pt
->adjusted_pf
.discard_passdown
;
2392 static void set_discard_callbacks(struct pool
*pool
)
2394 struct pool_c
*pt
= pool
->ti
->private;
2396 if (passdown_enabled(pt
)) {
2397 pool
->process_discard_cell
= process_discard_cell_passdown
;
2398 pool
->process_prepared_discard
= process_prepared_discard_passdown
;
2400 pool
->process_discard_cell
= process_discard_cell_no_passdown
;
2401 pool
->process_prepared_discard
= process_prepared_discard_no_passdown
;
2405 static void set_pool_mode(struct pool
*pool
, enum pool_mode new_mode
)
2407 struct pool_c
*pt
= pool
->ti
->private;
2408 bool needs_check
= dm_pool_metadata_needs_check(pool
->pmd
);
2409 enum pool_mode old_mode
= get_pool_mode(pool
);
2410 unsigned long no_space_timeout
= ACCESS_ONCE(no_space_timeout_secs
) * HZ
;
2413 * Never allow the pool to transition to PM_WRITE mode if user
2414 * intervention is required to verify metadata and data consistency.
2416 if (new_mode
== PM_WRITE
&& needs_check
) {
2417 DMERR("%s: unable to switch pool to write mode until repaired.",
2418 dm_device_name(pool
->pool_md
));
2419 if (old_mode
!= new_mode
)
2420 new_mode
= old_mode
;
2422 new_mode
= PM_READ_ONLY
;
2425 * If we were in PM_FAIL mode, rollback of metadata failed. We're
2426 * not going to recover without a thin_repair. So we never let the
2427 * pool move out of the old mode.
2429 if (old_mode
== PM_FAIL
)
2430 new_mode
= old_mode
;
2434 if (old_mode
!= new_mode
)
2435 notify_of_pool_mode_change(pool
, "failure");
2436 dm_pool_metadata_read_only(pool
->pmd
);
2437 pool
->process_bio
= process_bio_fail
;
2438 pool
->process_discard
= process_bio_fail
;
2439 pool
->process_cell
= process_cell_fail
;
2440 pool
->process_discard_cell
= process_cell_fail
;
2441 pool
->process_prepared_mapping
= process_prepared_mapping_fail
;
2442 pool
->process_prepared_discard
= process_prepared_discard_fail
;
2444 error_retry_list(pool
);
2448 if (old_mode
!= new_mode
)
2449 notify_of_pool_mode_change(pool
, "read-only");
2450 dm_pool_metadata_read_only(pool
->pmd
);
2451 pool
->process_bio
= process_bio_read_only
;
2452 pool
->process_discard
= process_bio_success
;
2453 pool
->process_cell
= process_cell_read_only
;
2454 pool
->process_discard_cell
= process_cell_success
;
2455 pool
->process_prepared_mapping
= process_prepared_mapping_fail
;
2456 pool
->process_prepared_discard
= process_prepared_discard_success
;
2458 error_retry_list(pool
);
2461 case PM_OUT_OF_DATA_SPACE
:
2463 * Ideally we'd never hit this state; the low water mark
2464 * would trigger userland to extend the pool before we
2465 * completely run out of data space. However, many small
2466 * IOs to unprovisioned space can consume data space at an
2467 * alarming rate. Adjust your low water mark if you're
2468 * frequently seeing this mode.
2470 if (old_mode
!= new_mode
)
2471 notify_of_pool_mode_change_to_oods(pool
);
2472 pool
->process_bio
= process_bio_read_only
;
2473 pool
->process_discard
= process_discard_bio
;
2474 pool
->process_cell
= process_cell_read_only
;
2475 pool
->process_prepared_mapping
= process_prepared_mapping
;
2476 set_discard_callbacks(pool
);
2478 if (!pool
->pf
.error_if_no_space
&& no_space_timeout
)
2479 queue_delayed_work(pool
->wq
, &pool
->no_space_timeout
, no_space_timeout
);
2483 if (old_mode
!= new_mode
)
2484 notify_of_pool_mode_change(pool
, "write");
2485 dm_pool_metadata_read_write(pool
->pmd
);
2486 pool
->process_bio
= process_bio
;
2487 pool
->process_discard
= process_discard_bio
;
2488 pool
->process_cell
= process_cell
;
2489 pool
->process_prepared_mapping
= process_prepared_mapping
;
2490 set_discard_callbacks(pool
);
2494 pool
->pf
.mode
= new_mode
;
2496 * The pool mode may have changed, sync it so bind_control_target()
2497 * doesn't cause an unexpected mode transition on resume.
2499 pt
->adjusted_pf
.mode
= new_mode
;
2502 static void abort_transaction(struct pool
*pool
)
2504 const char *dev_name
= dm_device_name(pool
->pool_md
);
2506 DMERR_LIMIT("%s: aborting current metadata transaction", dev_name
);
2507 if (dm_pool_abort_metadata(pool
->pmd
)) {
2508 DMERR("%s: failed to abort metadata transaction", dev_name
);
2509 set_pool_mode(pool
, PM_FAIL
);
2512 if (dm_pool_metadata_set_needs_check(pool
->pmd
)) {
2513 DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name
);
2514 set_pool_mode(pool
, PM_FAIL
);
2518 static void metadata_operation_failed(struct pool
*pool
, const char *op
, int r
)
2520 DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d",
2521 dm_device_name(pool
->pool_md
), op
, r
);
2523 abort_transaction(pool
);
2524 set_pool_mode(pool
, PM_READ_ONLY
);
2527 /*----------------------------------------------------------------*/
2530 * Mapping functions.
2534 * Called only while mapping a thin bio to hand it over to the workqueue.
2536 static void thin_defer_bio(struct thin_c
*tc
, struct bio
*bio
)
2538 unsigned long flags
;
2539 struct pool
*pool
= tc
->pool
;
2541 spin_lock_irqsave(&tc
->lock
, flags
);
2542 bio_list_add(&tc
->deferred_bio_list
, bio
);
2543 spin_unlock_irqrestore(&tc
->lock
, flags
);
2548 static void thin_defer_bio_with_throttle(struct thin_c
*tc
, struct bio
*bio
)
2550 struct pool
*pool
= tc
->pool
;
2552 throttle_lock(&pool
->throttle
);
2553 thin_defer_bio(tc
, bio
);
2554 throttle_unlock(&pool
->throttle
);
2557 static void thin_defer_cell(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
2559 unsigned long flags
;
2560 struct pool
*pool
= tc
->pool
;
2562 throttle_lock(&pool
->throttle
);
2563 spin_lock_irqsave(&tc
->lock
, flags
);
2564 list_add_tail(&cell
->user_list
, &tc
->deferred_cells
);
2565 spin_unlock_irqrestore(&tc
->lock
, flags
);
2566 throttle_unlock(&pool
->throttle
);
2571 static void thin_hook_bio(struct thin_c
*tc
, struct bio
*bio
)
2573 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
2576 h
->shared_read_entry
= NULL
;
2577 h
->all_io_entry
= NULL
;
2578 h
->overwrite_mapping
= NULL
;
2583 * Non-blocking function called from the thin target's map function.
2585 static int thin_bio_map(struct dm_target
*ti
, struct bio
*bio
)
2588 struct thin_c
*tc
= ti
->private;
2589 dm_block_t block
= get_bio_block(tc
, bio
);
2590 struct dm_thin_device
*td
= tc
->td
;
2591 struct dm_thin_lookup_result result
;
2592 struct dm_bio_prison_cell
*virt_cell
, *data_cell
;
2593 struct dm_cell_key key
;
2595 thin_hook_bio(tc
, bio
);
2597 if (tc
->requeue_mode
) {
2598 bio_endio(bio
, DM_ENDIO_REQUEUE
);
2599 return DM_MAPIO_SUBMITTED
;
2602 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
2604 return DM_MAPIO_SUBMITTED
;
2607 if (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
)) {
2608 thin_defer_bio_with_throttle(tc
, bio
);
2609 return DM_MAPIO_SUBMITTED
;
2613 * We must hold the virtual cell before doing the lookup, otherwise
2614 * there's a race with discard.
2616 build_virtual_key(tc
->td
, block
, &key
);
2617 if (bio_detain(tc
->pool
, &key
, bio
, &virt_cell
))
2618 return DM_MAPIO_SUBMITTED
;
2620 r
= dm_thin_find_block(td
, block
, 0, &result
);
2623 * Note that we defer readahead too.
2627 if (unlikely(result
.shared
)) {
2629 * We have a race condition here between the
2630 * result.shared value returned by the lookup and
2631 * snapshot creation, which may cause new
2634 * To avoid this always quiesce the origin before
2635 * taking the snap. You want to do this anyway to
2636 * ensure a consistent application view
2639 * More distant ancestors are irrelevant. The
2640 * shared flag will be set in their case.
2642 thin_defer_cell(tc
, virt_cell
);
2643 return DM_MAPIO_SUBMITTED
;
2646 build_data_key(tc
->td
, result
.block
, &key
);
2647 if (bio_detain(tc
->pool
, &key
, bio
, &data_cell
)) {
2648 cell_defer_no_holder(tc
, virt_cell
);
2649 return DM_MAPIO_SUBMITTED
;
2652 inc_all_io_entry(tc
->pool
, bio
);
2653 cell_defer_no_holder(tc
, data_cell
);
2654 cell_defer_no_holder(tc
, virt_cell
);
2656 remap(tc
, bio
, result
.block
);
2657 return DM_MAPIO_REMAPPED
;
2661 thin_defer_cell(tc
, virt_cell
);
2662 return DM_MAPIO_SUBMITTED
;
2666 * Must always call bio_io_error on failure.
2667 * dm_thin_find_block can fail with -EINVAL if the
2668 * pool is switched to fail-io mode.
2671 cell_defer_no_holder(tc
, virt_cell
);
2672 return DM_MAPIO_SUBMITTED
;
2676 static int pool_is_congested(struct dm_target_callbacks
*cb
, int bdi_bits
)
2678 struct pool_c
*pt
= container_of(cb
, struct pool_c
, callbacks
);
2679 struct request_queue
*q
;
2681 if (get_pool_mode(pt
->pool
) == PM_OUT_OF_DATA_SPACE
)
2684 q
= bdev_get_queue(pt
->data_dev
->bdev
);
2685 return bdi_congested(&q
->backing_dev_info
, bdi_bits
);
2688 static void requeue_bios(struct pool
*pool
)
2690 unsigned long flags
;
2694 list_for_each_entry_rcu(tc
, &pool
->active_thins
, list
) {
2695 spin_lock_irqsave(&tc
->lock
, flags
);
2696 bio_list_merge(&tc
->deferred_bio_list
, &tc
->retry_on_resume_list
);
2697 bio_list_init(&tc
->retry_on_resume_list
);
2698 spin_unlock_irqrestore(&tc
->lock
, flags
);
2703 /*----------------------------------------------------------------
2704 * Binding of control targets to a pool object
2705 *--------------------------------------------------------------*/
2706 static bool data_dev_supports_discard(struct pool_c
*pt
)
2708 struct request_queue
*q
= bdev_get_queue(pt
->data_dev
->bdev
);
2710 return q
&& blk_queue_discard(q
);
2713 static bool is_factor(sector_t block_size
, uint32_t n
)
2715 return !sector_div(block_size
, n
);
2719 * If discard_passdown was enabled verify that the data device
2720 * supports discards. Disable discard_passdown if not.
2722 static void disable_passdown_if_not_supported(struct pool_c
*pt
)
2724 struct pool
*pool
= pt
->pool
;
2725 struct block_device
*data_bdev
= pt
->data_dev
->bdev
;
2726 struct queue_limits
*data_limits
= &bdev_get_queue(data_bdev
)->limits
;
2727 const char *reason
= NULL
;
2728 char buf
[BDEVNAME_SIZE
];
2730 if (!pt
->adjusted_pf
.discard_passdown
)
2733 if (!data_dev_supports_discard(pt
))
2734 reason
= "discard unsupported";
2736 else if (data_limits
->max_discard_sectors
< pool
->sectors_per_block
)
2737 reason
= "max discard sectors smaller than a block";
2740 DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev
, buf
), reason
);
2741 pt
->adjusted_pf
.discard_passdown
= false;
2745 static int bind_control_target(struct pool
*pool
, struct dm_target
*ti
)
2747 struct pool_c
*pt
= ti
->private;
2750 * We want to make sure that a pool in PM_FAIL mode is never upgraded.
2752 enum pool_mode old_mode
= get_pool_mode(pool
);
2753 enum pool_mode new_mode
= pt
->adjusted_pf
.mode
;
2756 * Don't change the pool's mode until set_pool_mode() below.
2757 * Otherwise the pool's process_* function pointers may
2758 * not match the desired pool mode.
2760 pt
->adjusted_pf
.mode
= old_mode
;
2763 pool
->pf
= pt
->adjusted_pf
;
2764 pool
->low_water_blocks
= pt
->low_water_blocks
;
2766 set_pool_mode(pool
, new_mode
);
2771 static void unbind_control_target(struct pool
*pool
, struct dm_target
*ti
)
2777 /*----------------------------------------------------------------
2779 *--------------------------------------------------------------*/
2780 /* Initialize pool features. */
2781 static void pool_features_init(struct pool_features
*pf
)
2783 pf
->mode
= PM_WRITE
;
2784 pf
->zero_new_blocks
= true;
2785 pf
->discard_enabled
= true;
2786 pf
->discard_passdown
= true;
2787 pf
->error_if_no_space
= false;
2790 static void __pool_destroy(struct pool
*pool
)
2792 __pool_table_remove(pool
);
2794 vfree(pool
->cell_sort_array
);
2795 if (dm_pool_metadata_close(pool
->pmd
) < 0)
2796 DMWARN("%s: dm_pool_metadata_close() failed.", __func__
);
2798 dm_bio_prison_destroy(pool
->prison
);
2799 dm_kcopyd_client_destroy(pool
->copier
);
2802 destroy_workqueue(pool
->wq
);
2804 if (pool
->next_mapping
)
2805 mempool_free(pool
->next_mapping
, pool
->mapping_pool
);
2806 mempool_destroy(pool
->mapping_pool
);
2807 dm_deferred_set_destroy(pool
->shared_read_ds
);
2808 dm_deferred_set_destroy(pool
->all_io_ds
);
2812 static struct kmem_cache
*_new_mapping_cache
;
2814 static struct pool
*pool_create(struct mapped_device
*pool_md
,
2815 struct block_device
*metadata_dev
,
2816 unsigned long block_size
,
2817 int read_only
, char **error
)
2822 struct dm_pool_metadata
*pmd
;
2823 bool format_device
= read_only
? false : true;
2825 pmd
= dm_pool_metadata_open(metadata_dev
, block_size
, format_device
);
2827 *error
= "Error creating metadata object";
2828 return (struct pool
*)pmd
;
2831 pool
= kmalloc(sizeof(*pool
), GFP_KERNEL
);
2833 *error
= "Error allocating memory for pool";
2834 err_p
= ERR_PTR(-ENOMEM
);
2839 pool
->sectors_per_block
= block_size
;
2840 if (block_size
& (block_size
- 1))
2841 pool
->sectors_per_block_shift
= -1;
2843 pool
->sectors_per_block_shift
= __ffs(block_size
);
2844 pool
->low_water_blocks
= 0;
2845 pool_features_init(&pool
->pf
);
2846 pool
->prison
= dm_bio_prison_create();
2847 if (!pool
->prison
) {
2848 *error
= "Error creating pool's bio prison";
2849 err_p
= ERR_PTR(-ENOMEM
);
2853 pool
->copier
= dm_kcopyd_client_create(&dm_kcopyd_throttle
);
2854 if (IS_ERR(pool
->copier
)) {
2855 r
= PTR_ERR(pool
->copier
);
2856 *error
= "Error creating pool's kcopyd client";
2858 goto bad_kcopyd_client
;
2862 * Create singlethreaded workqueue that will service all devices
2863 * that use this metadata.
2865 pool
->wq
= alloc_ordered_workqueue("dm-" DM_MSG_PREFIX
, WQ_MEM_RECLAIM
);
2867 *error
= "Error creating pool's workqueue";
2868 err_p
= ERR_PTR(-ENOMEM
);
2872 throttle_init(&pool
->throttle
);
2873 INIT_WORK(&pool
->worker
, do_worker
);
2874 INIT_DELAYED_WORK(&pool
->waker
, do_waker
);
2875 INIT_DELAYED_WORK(&pool
->no_space_timeout
, do_no_space_timeout
);
2876 spin_lock_init(&pool
->lock
);
2877 bio_list_init(&pool
->deferred_flush_bios
);
2878 INIT_LIST_HEAD(&pool
->prepared_mappings
);
2879 INIT_LIST_HEAD(&pool
->prepared_discards
);
2880 INIT_LIST_HEAD(&pool
->active_thins
);
2881 pool
->low_water_triggered
= false;
2882 pool
->suspended
= true;
2884 pool
->shared_read_ds
= dm_deferred_set_create();
2885 if (!pool
->shared_read_ds
) {
2886 *error
= "Error creating pool's shared read deferred set";
2887 err_p
= ERR_PTR(-ENOMEM
);
2888 goto bad_shared_read_ds
;
2891 pool
->all_io_ds
= dm_deferred_set_create();
2892 if (!pool
->all_io_ds
) {
2893 *error
= "Error creating pool's all io deferred set";
2894 err_p
= ERR_PTR(-ENOMEM
);
2898 pool
->next_mapping
= NULL
;
2899 pool
->mapping_pool
= mempool_create_slab_pool(MAPPING_POOL_SIZE
,
2900 _new_mapping_cache
);
2901 if (!pool
->mapping_pool
) {
2902 *error
= "Error creating pool's mapping mempool";
2903 err_p
= ERR_PTR(-ENOMEM
);
2904 goto bad_mapping_pool
;
2907 pool
->cell_sort_array
= vmalloc(sizeof(*pool
->cell_sort_array
) * CELL_SORT_ARRAY_SIZE
);
2908 if (!pool
->cell_sort_array
) {
2909 *error
= "Error allocating cell sort array";
2910 err_p
= ERR_PTR(-ENOMEM
);
2911 goto bad_sort_array
;
2914 pool
->ref_count
= 1;
2915 pool
->last_commit_jiffies
= jiffies
;
2916 pool
->pool_md
= pool_md
;
2917 pool
->md_dev
= metadata_dev
;
2918 __pool_table_insert(pool
);
2923 mempool_destroy(pool
->mapping_pool
);
2925 dm_deferred_set_destroy(pool
->all_io_ds
);
2927 dm_deferred_set_destroy(pool
->shared_read_ds
);
2929 destroy_workqueue(pool
->wq
);
2931 dm_kcopyd_client_destroy(pool
->copier
);
2933 dm_bio_prison_destroy(pool
->prison
);
2937 if (dm_pool_metadata_close(pmd
))
2938 DMWARN("%s: dm_pool_metadata_close() failed.", __func__
);
2943 static void __pool_inc(struct pool
*pool
)
2945 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
2949 static void __pool_dec(struct pool
*pool
)
2951 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
2952 BUG_ON(!pool
->ref_count
);
2953 if (!--pool
->ref_count
)
2954 __pool_destroy(pool
);
2957 static struct pool
*__pool_find(struct mapped_device
*pool_md
,
2958 struct block_device
*metadata_dev
,
2959 unsigned long block_size
, int read_only
,
2960 char **error
, int *created
)
2962 struct pool
*pool
= __pool_table_lookup_metadata_dev(metadata_dev
);
2965 if (pool
->pool_md
!= pool_md
) {
2966 *error
= "metadata device already in use by a pool";
2967 return ERR_PTR(-EBUSY
);
2972 pool
= __pool_table_lookup(pool_md
);
2974 if (pool
->md_dev
!= metadata_dev
) {
2975 *error
= "different pool cannot replace a pool";
2976 return ERR_PTR(-EINVAL
);
2981 pool
= pool_create(pool_md
, metadata_dev
, block_size
, read_only
, error
);
2989 /*----------------------------------------------------------------
2990 * Pool target methods
2991 *--------------------------------------------------------------*/
2992 static void pool_dtr(struct dm_target
*ti
)
2994 struct pool_c
*pt
= ti
->private;
2996 mutex_lock(&dm_thin_pool_table
.mutex
);
2998 unbind_control_target(pt
->pool
, ti
);
2999 __pool_dec(pt
->pool
);
3000 dm_put_device(ti
, pt
->metadata_dev
);
3001 dm_put_device(ti
, pt
->data_dev
);
3004 mutex_unlock(&dm_thin_pool_table
.mutex
);
3007 static int parse_pool_features(struct dm_arg_set
*as
, struct pool_features
*pf
,
3008 struct dm_target
*ti
)
3012 const char *arg_name
;
3014 static struct dm_arg _args
[] = {
3015 {0, 4, "Invalid number of pool feature arguments"},
3019 * No feature arguments supplied.
3024 r
= dm_read_arg_group(_args
, as
, &argc
, &ti
->error
);
3028 while (argc
&& !r
) {
3029 arg_name
= dm_shift_arg(as
);
3032 if (!strcasecmp(arg_name
, "skip_block_zeroing"))
3033 pf
->zero_new_blocks
= false;
3035 else if (!strcasecmp(arg_name
, "ignore_discard"))
3036 pf
->discard_enabled
= false;
3038 else if (!strcasecmp(arg_name
, "no_discard_passdown"))
3039 pf
->discard_passdown
= false;
3041 else if (!strcasecmp(arg_name
, "read_only"))
3042 pf
->mode
= PM_READ_ONLY
;
3044 else if (!strcasecmp(arg_name
, "error_if_no_space"))
3045 pf
->error_if_no_space
= true;
3048 ti
->error
= "Unrecognised pool feature requested";
3057 static void metadata_low_callback(void *context
)
3059 struct pool
*pool
= context
;
3061 DMWARN("%s: reached low water mark for metadata device: sending event.",
3062 dm_device_name(pool
->pool_md
));
3064 dm_table_event(pool
->ti
->table
);
3067 static sector_t
get_dev_size(struct block_device
*bdev
)
3069 return i_size_read(bdev
->bd_inode
) >> SECTOR_SHIFT
;
3072 static void warn_if_metadata_device_too_big(struct block_device
*bdev
)
3074 sector_t metadata_dev_size
= get_dev_size(bdev
);
3075 char buffer
[BDEVNAME_SIZE
];
3077 if (metadata_dev_size
> THIN_METADATA_MAX_SECTORS_WARNING
)
3078 DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",
3079 bdevname(bdev
, buffer
), THIN_METADATA_MAX_SECTORS
);
3082 static sector_t
get_metadata_dev_size(struct block_device
*bdev
)
3084 sector_t metadata_dev_size
= get_dev_size(bdev
);
3086 if (metadata_dev_size
> THIN_METADATA_MAX_SECTORS
)
3087 metadata_dev_size
= THIN_METADATA_MAX_SECTORS
;
3089 return metadata_dev_size
;
3092 static dm_block_t
get_metadata_dev_size_in_blocks(struct block_device
*bdev
)
3094 sector_t metadata_dev_size
= get_metadata_dev_size(bdev
);
3096 sector_div(metadata_dev_size
, THIN_METADATA_BLOCK_SIZE
);
3098 return metadata_dev_size
;
3102 * When a metadata threshold is crossed a dm event is triggered, and
3103 * userland should respond by growing the metadata device. We could let
3104 * userland set the threshold, like we do with the data threshold, but I'm
3105 * not sure they know enough to do this well.
3107 static dm_block_t
calc_metadata_threshold(struct pool_c
*pt
)
3110 * 4M is ample for all ops with the possible exception of thin
3111 * device deletion which is harmless if it fails (just retry the
3112 * delete after you've grown the device).
3114 dm_block_t quarter
= get_metadata_dev_size_in_blocks(pt
->metadata_dev
->bdev
) / 4;
3115 return min((dm_block_t
)1024ULL /* 4M */, quarter
);
3119 * thin-pool <metadata dev> <data dev>
3120 * <data block size (sectors)>
3121 * <low water mark (blocks)>
3122 * [<#feature args> [<arg>]*]
3124 * Optional feature arguments are:
3125 * skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
3126 * ignore_discard: disable discard
3127 * no_discard_passdown: don't pass discards down to the data device
3128 * read_only: Don't allow any changes to be made to the pool metadata.
3129 * error_if_no_space: error IOs, instead of queueing, if no space.
3131 static int pool_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
3133 int r
, pool_created
= 0;
3136 struct pool_features pf
;
3137 struct dm_arg_set as
;
3138 struct dm_dev
*data_dev
;
3139 unsigned long block_size
;
3140 dm_block_t low_water_blocks
;
3141 struct dm_dev
*metadata_dev
;
3142 fmode_t metadata_mode
;
3145 * FIXME Remove validation from scope of lock.
3147 mutex_lock(&dm_thin_pool_table
.mutex
);
3150 ti
->error
= "Invalid argument count";
3159 * Set default pool features.
3161 pool_features_init(&pf
);
3163 dm_consume_args(&as
, 4);
3164 r
= parse_pool_features(&as
, &pf
, ti
);
3168 metadata_mode
= FMODE_READ
| ((pf
.mode
== PM_READ_ONLY
) ? 0 : FMODE_WRITE
);
3169 r
= dm_get_device(ti
, argv
[0], metadata_mode
, &metadata_dev
);
3171 ti
->error
= "Error opening metadata block device";
3174 warn_if_metadata_device_too_big(metadata_dev
->bdev
);
3176 r
= dm_get_device(ti
, argv
[1], FMODE_READ
| FMODE_WRITE
, &data_dev
);
3178 ti
->error
= "Error getting data device";
3182 if (kstrtoul(argv
[2], 10, &block_size
) || !block_size
||
3183 block_size
< DATA_DEV_BLOCK_SIZE_MIN_SECTORS
||
3184 block_size
> DATA_DEV_BLOCK_SIZE_MAX_SECTORS
||
3185 block_size
& (DATA_DEV_BLOCK_SIZE_MIN_SECTORS
- 1)) {
3186 ti
->error
= "Invalid block size";
3191 if (kstrtoull(argv
[3], 10, (unsigned long long *)&low_water_blocks
)) {
3192 ti
->error
= "Invalid low water mark";
3197 pt
= kzalloc(sizeof(*pt
), GFP_KERNEL
);
3203 pool
= __pool_find(dm_table_get_md(ti
->table
), metadata_dev
->bdev
,
3204 block_size
, pf
.mode
== PM_READ_ONLY
, &ti
->error
, &pool_created
);
3211 * 'pool_created' reflects whether this is the first table load.
3212 * Top level discard support is not allowed to be changed after
3213 * initial load. This would require a pool reload to trigger thin
3216 if (!pool_created
&& pf
.discard_enabled
!= pool
->pf
.discard_enabled
) {
3217 ti
->error
= "Discard support cannot be disabled once enabled";
3219 goto out_flags_changed
;
3224 pt
->metadata_dev
= metadata_dev
;
3225 pt
->data_dev
= data_dev
;
3226 pt
->low_water_blocks
= low_water_blocks
;
3227 pt
->adjusted_pf
= pt
->requested_pf
= pf
;
3228 ti
->num_flush_bios
= 1;
3231 * Only need to enable discards if the pool should pass
3232 * them down to the data device. The thin device's discard
3233 * processing will cause mappings to be removed from the btree.
3235 ti
->discard_zeroes_data_unsupported
= true;
3236 if (pf
.discard_enabled
&& pf
.discard_passdown
) {
3237 ti
->num_discard_bios
= 1;
3240 * Setting 'discards_supported' circumvents the normal
3241 * stacking of discard limits (this keeps the pool and
3242 * thin devices' discard limits consistent).
3244 ti
->discards_supported
= true;
3248 r
= dm_pool_register_metadata_threshold(pt
->pool
->pmd
,
3249 calc_metadata_threshold(pt
),
3250 metadata_low_callback
,
3255 pt
->callbacks
.congested_fn
= pool_is_congested
;
3256 dm_table_add_target_callbacks(ti
->table
, &pt
->callbacks
);
3258 mutex_unlock(&dm_thin_pool_table
.mutex
);
3267 dm_put_device(ti
, data_dev
);
3269 dm_put_device(ti
, metadata_dev
);
3271 mutex_unlock(&dm_thin_pool_table
.mutex
);
3276 static int pool_map(struct dm_target
*ti
, struct bio
*bio
)
3279 struct pool_c
*pt
= ti
->private;
3280 struct pool
*pool
= pt
->pool
;
3281 unsigned long flags
;
3284 * As this is a singleton target, ti->begin is always zero.
3286 spin_lock_irqsave(&pool
->lock
, flags
);
3287 bio
->bi_bdev
= pt
->data_dev
->bdev
;
3288 r
= DM_MAPIO_REMAPPED
;
3289 spin_unlock_irqrestore(&pool
->lock
, flags
);
3294 static int maybe_resize_data_dev(struct dm_target
*ti
, bool *need_commit
)
3297 struct pool_c
*pt
= ti
->private;
3298 struct pool
*pool
= pt
->pool
;
3299 sector_t data_size
= ti
->len
;
3300 dm_block_t sb_data_size
;
3302 *need_commit
= false;
3304 (void) sector_div(data_size
, pool
->sectors_per_block
);
3306 r
= dm_pool_get_data_dev_size(pool
->pmd
, &sb_data_size
);
3308 DMERR("%s: failed to retrieve data device size",
3309 dm_device_name(pool
->pool_md
));
3313 if (data_size
< sb_data_size
) {
3314 DMERR("%s: pool target (%llu blocks) too small: expected %llu",
3315 dm_device_name(pool
->pool_md
),
3316 (unsigned long long)data_size
, sb_data_size
);
3319 } else if (data_size
> sb_data_size
) {
3320 if (dm_pool_metadata_needs_check(pool
->pmd
)) {
3321 DMERR("%s: unable to grow the data device until repaired.",
3322 dm_device_name(pool
->pool_md
));
3327 DMINFO("%s: growing the data device from %llu to %llu blocks",
3328 dm_device_name(pool
->pool_md
),
3329 sb_data_size
, (unsigned long long)data_size
);
3330 r
= dm_pool_resize_data_dev(pool
->pmd
, data_size
);
3332 metadata_operation_failed(pool
, "dm_pool_resize_data_dev", r
);
3336 *need_commit
= true;
3342 static int maybe_resize_metadata_dev(struct dm_target
*ti
, bool *need_commit
)
3345 struct pool_c
*pt
= ti
->private;
3346 struct pool
*pool
= pt
->pool
;
3347 dm_block_t metadata_dev_size
, sb_metadata_dev_size
;
3349 *need_commit
= false;
3351 metadata_dev_size
= get_metadata_dev_size_in_blocks(pool
->md_dev
);
3353 r
= dm_pool_get_metadata_dev_size(pool
->pmd
, &sb_metadata_dev_size
);
3355 DMERR("%s: failed to retrieve metadata device size",
3356 dm_device_name(pool
->pool_md
));
3360 if (metadata_dev_size
< sb_metadata_dev_size
) {
3361 DMERR("%s: metadata device (%llu blocks) too small: expected %llu",
3362 dm_device_name(pool
->pool_md
),
3363 metadata_dev_size
, sb_metadata_dev_size
);
3366 } else if (metadata_dev_size
> sb_metadata_dev_size
) {
3367 if (dm_pool_metadata_needs_check(pool
->pmd
)) {
3368 DMERR("%s: unable to grow the metadata device until repaired.",
3369 dm_device_name(pool
->pool_md
));
3373 warn_if_metadata_device_too_big(pool
->md_dev
);
3374 DMINFO("%s: growing the metadata device from %llu to %llu blocks",
3375 dm_device_name(pool
->pool_md
),
3376 sb_metadata_dev_size
, metadata_dev_size
);
3377 r
= dm_pool_resize_metadata_dev(pool
->pmd
, metadata_dev_size
);
3379 metadata_operation_failed(pool
, "dm_pool_resize_metadata_dev", r
);
3383 *need_commit
= true;
3390 * Retrieves the number of blocks of the data device from
3391 * the superblock and compares it to the actual device size,
3392 * thus resizing the data device in case it has grown.
3394 * This both copes with opening preallocated data devices in the ctr
3395 * being followed by a resume
3397 * calling the resume method individually after userspace has
3398 * grown the data device in reaction to a table event.
3400 static int pool_preresume(struct dm_target
*ti
)
3403 bool need_commit1
, need_commit2
;
3404 struct pool_c
*pt
= ti
->private;
3405 struct pool
*pool
= pt
->pool
;
3408 * Take control of the pool object.
3410 r
= bind_control_target(pool
, ti
);
3414 r
= maybe_resize_data_dev(ti
, &need_commit1
);
3418 r
= maybe_resize_metadata_dev(ti
, &need_commit2
);
3422 if (need_commit1
|| need_commit2
)
3423 (void) commit(pool
);
3428 static void pool_suspend_active_thins(struct pool
*pool
)
3432 /* Suspend all active thin devices */
3433 tc
= get_first_thin(pool
);
3435 dm_internal_suspend_noflush(tc
->thin_md
);
3436 tc
= get_next_thin(pool
, tc
);
3440 static void pool_resume_active_thins(struct pool
*pool
)
3444 /* Resume all active thin devices */
3445 tc
= get_first_thin(pool
);
3447 dm_internal_resume(tc
->thin_md
);
3448 tc
= get_next_thin(pool
, tc
);
3452 static void pool_resume(struct dm_target
*ti
)
3454 struct pool_c
*pt
= ti
->private;
3455 struct pool
*pool
= pt
->pool
;
3456 unsigned long flags
;
3459 * Must requeue active_thins' bios and then resume
3460 * active_thins _before_ clearing 'suspend' flag.
3463 pool_resume_active_thins(pool
);
3465 spin_lock_irqsave(&pool
->lock
, flags
);
3466 pool
->low_water_triggered
= false;
3467 pool
->suspended
= false;
3468 spin_unlock_irqrestore(&pool
->lock
, flags
);
3470 do_waker(&pool
->waker
.work
);
3473 static void pool_presuspend(struct dm_target
*ti
)
3475 struct pool_c
*pt
= ti
->private;
3476 struct pool
*pool
= pt
->pool
;
3477 unsigned long flags
;
3479 spin_lock_irqsave(&pool
->lock
, flags
);
3480 pool
->suspended
= true;
3481 spin_unlock_irqrestore(&pool
->lock
, flags
);
3483 pool_suspend_active_thins(pool
);
3486 static void pool_presuspend_undo(struct dm_target
*ti
)
3488 struct pool_c
*pt
= ti
->private;
3489 struct pool
*pool
= pt
->pool
;
3490 unsigned long flags
;
3492 pool_resume_active_thins(pool
);
3494 spin_lock_irqsave(&pool
->lock
, flags
);
3495 pool
->suspended
= false;
3496 spin_unlock_irqrestore(&pool
->lock
, flags
);
3499 static void pool_postsuspend(struct dm_target
*ti
)
3501 struct pool_c
*pt
= ti
->private;
3502 struct pool
*pool
= pt
->pool
;
3504 cancel_delayed_work(&pool
->waker
);
3505 cancel_delayed_work(&pool
->no_space_timeout
);
3506 flush_workqueue(pool
->wq
);
3507 (void) commit(pool
);
3510 static int check_arg_count(unsigned argc
, unsigned args_required
)
3512 if (argc
!= args_required
) {
3513 DMWARN("Message received with %u arguments instead of %u.",
3514 argc
, args_required
);
3521 static int read_dev_id(char *arg
, dm_thin_id
*dev_id
, int warning
)
3523 if (!kstrtoull(arg
, 10, (unsigned long long *)dev_id
) &&
3524 *dev_id
<= MAX_DEV_ID
)
3528 DMWARN("Message received with invalid device id: %s", arg
);
3533 static int process_create_thin_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3538 r
= check_arg_count(argc
, 2);
3542 r
= read_dev_id(argv
[1], &dev_id
, 1);
3546 r
= dm_pool_create_thin(pool
->pmd
, dev_id
);
3548 DMWARN("Creation of new thinly-provisioned device with id %s failed.",
3556 static int process_create_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3559 dm_thin_id origin_dev_id
;
3562 r
= check_arg_count(argc
, 3);
3566 r
= read_dev_id(argv
[1], &dev_id
, 1);
3570 r
= read_dev_id(argv
[2], &origin_dev_id
, 1);
3574 r
= dm_pool_create_snap(pool
->pmd
, dev_id
, origin_dev_id
);
3576 DMWARN("Creation of new snapshot %s of device %s failed.",
3584 static int process_delete_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3589 r
= check_arg_count(argc
, 2);
3593 r
= read_dev_id(argv
[1], &dev_id
, 1);
3597 r
= dm_pool_delete_thin_device(pool
->pmd
, dev_id
);
3599 DMWARN("Deletion of thin device %s failed.", argv
[1]);
3604 static int process_set_transaction_id_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3606 dm_thin_id old_id
, new_id
;
3609 r
= check_arg_count(argc
, 3);
3613 if (kstrtoull(argv
[1], 10, (unsigned long long *)&old_id
)) {
3614 DMWARN("set_transaction_id message: Unrecognised id %s.", argv
[1]);
3618 if (kstrtoull(argv
[2], 10, (unsigned long long *)&new_id
)) {
3619 DMWARN("set_transaction_id message: Unrecognised new id %s.", argv
[2]);
3623 r
= dm_pool_set_metadata_transaction_id(pool
->pmd
, old_id
, new_id
);
3625 DMWARN("Failed to change transaction id from %s to %s.",
3633 static int process_reserve_metadata_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3637 r
= check_arg_count(argc
, 1);
3641 (void) commit(pool
);
3643 r
= dm_pool_reserve_metadata_snap(pool
->pmd
);
3645 DMWARN("reserve_metadata_snap message failed.");
3650 static int process_release_metadata_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3654 r
= check_arg_count(argc
, 1);
3658 r
= dm_pool_release_metadata_snap(pool
->pmd
);
3660 DMWARN("release_metadata_snap message failed.");
3666 * Messages supported:
3667 * create_thin <dev_id>
3668 * create_snap <dev_id> <origin_id>
3670 * set_transaction_id <current_trans_id> <new_trans_id>
3671 * reserve_metadata_snap
3672 * release_metadata_snap
3674 static int pool_message(struct dm_target
*ti
, unsigned argc
, char **argv
)
3677 struct pool_c
*pt
= ti
->private;
3678 struct pool
*pool
= pt
->pool
;
3680 if (get_pool_mode(pool
) >= PM_READ_ONLY
) {
3681 DMERR("%s: unable to service pool target messages in READ_ONLY or FAIL mode",
3682 dm_device_name(pool
->pool_md
));
3686 if (!strcasecmp(argv
[0], "create_thin"))
3687 r
= process_create_thin_mesg(argc
, argv
, pool
);
3689 else if (!strcasecmp(argv
[0], "create_snap"))
3690 r
= process_create_snap_mesg(argc
, argv
, pool
);
3692 else if (!strcasecmp(argv
[0], "delete"))
3693 r
= process_delete_mesg(argc
, argv
, pool
);
3695 else if (!strcasecmp(argv
[0], "set_transaction_id"))
3696 r
= process_set_transaction_id_mesg(argc
, argv
, pool
);
3698 else if (!strcasecmp(argv
[0], "reserve_metadata_snap"))
3699 r
= process_reserve_metadata_snap_mesg(argc
, argv
, pool
);
3701 else if (!strcasecmp(argv
[0], "release_metadata_snap"))
3702 r
= process_release_metadata_snap_mesg(argc
, argv
, pool
);
3705 DMWARN("Unrecognised thin pool target message received: %s", argv
[0]);
3708 (void) commit(pool
);
3713 static void emit_flags(struct pool_features
*pf
, char *result
,
3714 unsigned sz
, unsigned maxlen
)
3716 unsigned count
= !pf
->zero_new_blocks
+ !pf
->discard_enabled
+
3717 !pf
->discard_passdown
+ (pf
->mode
== PM_READ_ONLY
) +
3718 pf
->error_if_no_space
;
3719 DMEMIT("%u ", count
);
3721 if (!pf
->zero_new_blocks
)
3722 DMEMIT("skip_block_zeroing ");
3724 if (!pf
->discard_enabled
)
3725 DMEMIT("ignore_discard ");
3727 if (!pf
->discard_passdown
)
3728 DMEMIT("no_discard_passdown ");
3730 if (pf
->mode
== PM_READ_ONLY
)
3731 DMEMIT("read_only ");
3733 if (pf
->error_if_no_space
)
3734 DMEMIT("error_if_no_space ");
3739 * <transaction id> <used metadata sectors>/<total metadata sectors>
3740 * <used data sectors>/<total data sectors> <held metadata root>
3741 * <pool mode> <discard config> <no space config> <needs_check>
3743 static void pool_status(struct dm_target
*ti
, status_type_t type
,
3744 unsigned status_flags
, char *result
, unsigned maxlen
)
3748 uint64_t transaction_id
;
3749 dm_block_t nr_free_blocks_data
;
3750 dm_block_t nr_free_blocks_metadata
;
3751 dm_block_t nr_blocks_data
;
3752 dm_block_t nr_blocks_metadata
;
3753 dm_block_t held_root
;
3754 char buf
[BDEVNAME_SIZE
];
3755 char buf2
[BDEVNAME_SIZE
];
3756 struct pool_c
*pt
= ti
->private;
3757 struct pool
*pool
= pt
->pool
;
3760 case STATUSTYPE_INFO
:
3761 if (get_pool_mode(pool
) == PM_FAIL
) {
3766 /* Commit to ensure statistics aren't out-of-date */
3767 if (!(status_flags
& DM_STATUS_NOFLUSH_FLAG
) && !dm_suspended(ti
))
3768 (void) commit(pool
);
3770 r
= dm_pool_get_metadata_transaction_id(pool
->pmd
, &transaction_id
);
3772 DMERR("%s: dm_pool_get_metadata_transaction_id returned %d",
3773 dm_device_name(pool
->pool_md
), r
);
3777 r
= dm_pool_get_free_metadata_block_count(pool
->pmd
, &nr_free_blocks_metadata
);
3779 DMERR("%s: dm_pool_get_free_metadata_block_count returned %d",
3780 dm_device_name(pool
->pool_md
), r
);
3784 r
= dm_pool_get_metadata_dev_size(pool
->pmd
, &nr_blocks_metadata
);
3786 DMERR("%s: dm_pool_get_metadata_dev_size returned %d",
3787 dm_device_name(pool
->pool_md
), r
);
3791 r
= dm_pool_get_free_block_count(pool
->pmd
, &nr_free_blocks_data
);
3793 DMERR("%s: dm_pool_get_free_block_count returned %d",
3794 dm_device_name(pool
->pool_md
), r
);
3798 r
= dm_pool_get_data_dev_size(pool
->pmd
, &nr_blocks_data
);
3800 DMERR("%s: dm_pool_get_data_dev_size returned %d",
3801 dm_device_name(pool
->pool_md
), r
);
3805 r
= dm_pool_get_metadata_snap(pool
->pmd
, &held_root
);
3807 DMERR("%s: dm_pool_get_metadata_snap returned %d",
3808 dm_device_name(pool
->pool_md
), r
);
3812 DMEMIT("%llu %llu/%llu %llu/%llu ",
3813 (unsigned long long)transaction_id
,
3814 (unsigned long long)(nr_blocks_metadata
- nr_free_blocks_metadata
),
3815 (unsigned long long)nr_blocks_metadata
,
3816 (unsigned long long)(nr_blocks_data
- nr_free_blocks_data
),
3817 (unsigned long long)nr_blocks_data
);
3820 DMEMIT("%llu ", held_root
);
3824 if (pool
->pf
.mode
== PM_OUT_OF_DATA_SPACE
)
3825 DMEMIT("out_of_data_space ");
3826 else if (pool
->pf
.mode
== PM_READ_ONLY
)
3831 if (!pool
->pf
.discard_enabled
)
3832 DMEMIT("ignore_discard ");
3833 else if (pool
->pf
.discard_passdown
)
3834 DMEMIT("discard_passdown ");
3836 DMEMIT("no_discard_passdown ");
3838 if (pool
->pf
.error_if_no_space
)
3839 DMEMIT("error_if_no_space ");
3841 DMEMIT("queue_if_no_space ");
3843 if (dm_pool_metadata_needs_check(pool
->pmd
))
3844 DMEMIT("needs_check ");
3850 case STATUSTYPE_TABLE
:
3851 DMEMIT("%s %s %lu %llu ",
3852 format_dev_t(buf
, pt
->metadata_dev
->bdev
->bd_dev
),
3853 format_dev_t(buf2
, pt
->data_dev
->bdev
->bd_dev
),
3854 (unsigned long)pool
->sectors_per_block
,
3855 (unsigned long long)pt
->low_water_blocks
);
3856 emit_flags(&pt
->requested_pf
, result
, sz
, maxlen
);
3865 static int pool_iterate_devices(struct dm_target
*ti
,
3866 iterate_devices_callout_fn fn
, void *data
)
3868 struct pool_c
*pt
= ti
->private;
3870 return fn(ti
, pt
->data_dev
, 0, ti
->len
, data
);
3873 static int pool_merge(struct dm_target
*ti
, struct bvec_merge_data
*bvm
,
3874 struct bio_vec
*biovec
, int max_size
)
3876 struct pool_c
*pt
= ti
->private;
3877 struct request_queue
*q
= bdev_get_queue(pt
->data_dev
->bdev
);
3879 if (!q
->merge_bvec_fn
)
3882 bvm
->bi_bdev
= pt
->data_dev
->bdev
;
3884 return min(max_size
, q
->merge_bvec_fn(q
, bvm
, biovec
));
3887 static void pool_io_hints(struct dm_target
*ti
, struct queue_limits
*limits
)
3889 struct pool_c
*pt
= ti
->private;
3890 struct pool
*pool
= pt
->pool
;
3891 sector_t io_opt_sectors
= limits
->io_opt
>> SECTOR_SHIFT
;
3894 * If max_sectors is smaller than pool->sectors_per_block adjust it
3895 * to the highest possible power-of-2 factor of pool->sectors_per_block.
3896 * This is especially beneficial when the pool's data device is a RAID
3897 * device that has a full stripe width that matches pool->sectors_per_block
3898 * -- because even though partial RAID stripe-sized IOs will be issued to a
3899 * single RAID stripe; when aggregated they will end on a full RAID stripe
3900 * boundary.. which avoids additional partial RAID stripe writes cascading
3902 if (limits
->max_sectors
< pool
->sectors_per_block
) {
3903 while (!is_factor(pool
->sectors_per_block
, limits
->max_sectors
)) {
3904 if ((limits
->max_sectors
& (limits
->max_sectors
- 1)) == 0)
3905 limits
->max_sectors
--;
3906 limits
->max_sectors
= rounddown_pow_of_two(limits
->max_sectors
);
3911 * If the system-determined stacked limits are compatible with the
3912 * pool's blocksize (io_opt is a factor) do not override them.
3914 if (io_opt_sectors
< pool
->sectors_per_block
||
3915 !is_factor(io_opt_sectors
, pool
->sectors_per_block
)) {
3916 if (is_factor(pool
->sectors_per_block
, limits
->max_sectors
))
3917 blk_limits_io_min(limits
, limits
->max_sectors
<< SECTOR_SHIFT
);
3919 blk_limits_io_min(limits
, pool
->sectors_per_block
<< SECTOR_SHIFT
);
3920 blk_limits_io_opt(limits
, pool
->sectors_per_block
<< SECTOR_SHIFT
);
3924 * pt->adjusted_pf is a staging area for the actual features to use.
3925 * They get transferred to the live pool in bind_control_target()
3926 * called from pool_preresume().
3928 if (!pt
->adjusted_pf
.discard_enabled
) {
3930 * Must explicitly disallow stacking discard limits otherwise the
3931 * block layer will stack them if pool's data device has support.
3932 * QUEUE_FLAG_DISCARD wouldn't be set but there is no way for the
3933 * user to see that, so make sure to set all discard limits to 0.
3935 limits
->discard_granularity
= 0;
3939 disable_passdown_if_not_supported(pt
);
3942 * The pool uses the same discard limits as the underlying data
3943 * device. DM core has already set this up.
3947 static struct target_type pool_target
= {
3948 .name
= "thin-pool",
3949 .features
= DM_TARGET_SINGLETON
| DM_TARGET_ALWAYS_WRITEABLE
|
3950 DM_TARGET_IMMUTABLE
,
3951 .version
= {1, 16, 0},
3952 .module
= THIS_MODULE
,
3956 .presuspend
= pool_presuspend
,
3957 .presuspend_undo
= pool_presuspend_undo
,
3958 .postsuspend
= pool_postsuspend
,
3959 .preresume
= pool_preresume
,
3960 .resume
= pool_resume
,
3961 .message
= pool_message
,
3962 .status
= pool_status
,
3963 .merge
= pool_merge
,
3964 .iterate_devices
= pool_iterate_devices
,
3965 .io_hints
= pool_io_hints
,
3968 /*----------------------------------------------------------------
3969 * Thin target methods
3970 *--------------------------------------------------------------*/
3971 static void thin_get(struct thin_c
*tc
)
3973 atomic_inc(&tc
->refcount
);
3976 static void thin_put(struct thin_c
*tc
)
3978 if (atomic_dec_and_test(&tc
->refcount
))
3979 complete(&tc
->can_destroy
);
3982 static void thin_dtr(struct dm_target
*ti
)
3984 struct thin_c
*tc
= ti
->private;
3985 unsigned long flags
;
3987 spin_lock_irqsave(&tc
->pool
->lock
, flags
);
3988 list_del_rcu(&tc
->list
);
3989 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
3993 wait_for_completion(&tc
->can_destroy
);
3995 mutex_lock(&dm_thin_pool_table
.mutex
);
3997 __pool_dec(tc
->pool
);
3998 dm_pool_close_thin_device(tc
->td
);
3999 dm_put_device(ti
, tc
->pool_dev
);
4001 dm_put_device(ti
, tc
->origin_dev
);
4004 mutex_unlock(&dm_thin_pool_table
.mutex
);
4008 * Thin target parameters:
4010 * <pool_dev> <dev_id> [origin_dev]
4012 * pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
4013 * dev_id: the internal device identifier
4014 * origin_dev: a device external to the pool that should act as the origin
4016 * If the pool device has discards disabled, they get disabled for the thin
4019 static int thin_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
4023 struct dm_dev
*pool_dev
, *origin_dev
;
4024 struct mapped_device
*pool_md
;
4025 unsigned long flags
;
4027 mutex_lock(&dm_thin_pool_table
.mutex
);
4029 if (argc
!= 2 && argc
!= 3) {
4030 ti
->error
= "Invalid argument count";
4035 tc
= ti
->private = kzalloc(sizeof(*tc
), GFP_KERNEL
);
4037 ti
->error
= "Out of memory";
4041 tc
->thin_md
= dm_table_get_md(ti
->table
);
4042 spin_lock_init(&tc
->lock
);
4043 INIT_LIST_HEAD(&tc
->deferred_cells
);
4044 bio_list_init(&tc
->deferred_bio_list
);
4045 bio_list_init(&tc
->retry_on_resume_list
);
4046 tc
->sort_bio_list
= RB_ROOT
;
4049 r
= dm_get_device(ti
, argv
[2], FMODE_READ
, &origin_dev
);
4051 ti
->error
= "Error opening origin device";
4052 goto bad_origin_dev
;
4054 tc
->origin_dev
= origin_dev
;
4057 r
= dm_get_device(ti
, argv
[0], dm_table_get_mode(ti
->table
), &pool_dev
);
4059 ti
->error
= "Error opening pool device";
4062 tc
->pool_dev
= pool_dev
;
4064 if (read_dev_id(argv
[1], (unsigned long long *)&tc
->dev_id
, 0)) {
4065 ti
->error
= "Invalid device id";
4070 pool_md
= dm_get_md(tc
->pool_dev
->bdev
->bd_dev
);
4072 ti
->error
= "Couldn't get pool mapped device";
4077 tc
->pool
= __pool_table_lookup(pool_md
);
4079 ti
->error
= "Couldn't find pool object";
4081 goto bad_pool_lookup
;
4083 __pool_inc(tc
->pool
);
4085 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
4086 ti
->error
= "Couldn't open thin device, Pool is in fail mode";
4091 r
= dm_pool_open_thin_device(tc
->pool
->pmd
, tc
->dev_id
, &tc
->td
);
4093 ti
->error
= "Couldn't open thin internal device";
4097 r
= dm_set_target_max_io_len(ti
, tc
->pool
->sectors_per_block
);
4101 ti
->num_flush_bios
= 1;
4102 ti
->flush_supported
= true;
4103 ti
->per_bio_data_size
= sizeof(struct dm_thin_endio_hook
);
4105 /* In case the pool supports discards, pass them on. */
4106 ti
->discard_zeroes_data_unsupported
= true;
4107 if (tc
->pool
->pf
.discard_enabled
) {
4108 ti
->discards_supported
= true;
4109 ti
->num_discard_bios
= 1;
4110 ti
->split_discard_bios
= false;
4113 mutex_unlock(&dm_thin_pool_table
.mutex
);
4115 spin_lock_irqsave(&tc
->pool
->lock
, flags
);
4116 if (tc
->pool
->suspended
) {
4117 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
4118 mutex_lock(&dm_thin_pool_table
.mutex
); /* reacquire for __pool_dec */
4119 ti
->error
= "Unable to activate thin device while pool is suspended";
4123 atomic_set(&tc
->refcount
, 1);
4124 init_completion(&tc
->can_destroy
);
4125 list_add_tail_rcu(&tc
->list
, &tc
->pool
->active_thins
);
4126 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
4128 * This synchronize_rcu() call is needed here otherwise we risk a
4129 * wake_worker() call finding no bios to process (because the newly
4130 * added tc isn't yet visible). So this reduces latency since we
4131 * aren't then dependent on the periodic commit to wake_worker().
4140 dm_pool_close_thin_device(tc
->td
);
4142 __pool_dec(tc
->pool
);
4146 dm_put_device(ti
, tc
->pool_dev
);
4149 dm_put_device(ti
, tc
->origin_dev
);
4153 mutex_unlock(&dm_thin_pool_table
.mutex
);
4158 static int thin_map(struct dm_target
*ti
, struct bio
*bio
)
4160 bio
->bi_iter
.bi_sector
= dm_target_offset(ti
, bio
->bi_iter
.bi_sector
);
4162 return thin_bio_map(ti
, bio
);
4165 static int thin_endio(struct dm_target
*ti
, struct bio
*bio
, int err
)
4167 unsigned long flags
;
4168 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
4169 struct list_head work
;
4170 struct dm_thin_new_mapping
*m
, *tmp
;
4171 struct pool
*pool
= h
->tc
->pool
;
4173 if (h
->shared_read_entry
) {
4174 INIT_LIST_HEAD(&work
);
4175 dm_deferred_entry_dec(h
->shared_read_entry
, &work
);
4177 spin_lock_irqsave(&pool
->lock
, flags
);
4178 list_for_each_entry_safe(m
, tmp
, &work
, list
) {
4180 __complete_mapping_preparation(m
);
4182 spin_unlock_irqrestore(&pool
->lock
, flags
);
4185 if (h
->all_io_entry
) {
4186 INIT_LIST_HEAD(&work
);
4187 dm_deferred_entry_dec(h
->all_io_entry
, &work
);
4188 if (!list_empty(&work
)) {
4189 spin_lock_irqsave(&pool
->lock
, flags
);
4190 list_for_each_entry_safe(m
, tmp
, &work
, list
)
4191 list_add_tail(&m
->list
, &pool
->prepared_discards
);
4192 spin_unlock_irqrestore(&pool
->lock
, flags
);
4198 cell_defer_no_holder(h
->tc
, h
->cell
);
4203 static void thin_presuspend(struct dm_target
*ti
)
4205 struct thin_c
*tc
= ti
->private;
4207 if (dm_noflush_suspending(ti
))
4208 noflush_work(tc
, do_noflush_start
);
4211 static void thin_postsuspend(struct dm_target
*ti
)
4213 struct thin_c
*tc
= ti
->private;
4216 * The dm_noflush_suspending flag has been cleared by now, so
4217 * unfortunately we must always run this.
4219 noflush_work(tc
, do_noflush_stop
);
4222 static int thin_preresume(struct dm_target
*ti
)
4224 struct thin_c
*tc
= ti
->private;
4227 tc
->origin_size
= get_dev_size(tc
->origin_dev
->bdev
);
4233 * <nr mapped sectors> <highest mapped sector>
4235 static void thin_status(struct dm_target
*ti
, status_type_t type
,
4236 unsigned status_flags
, char *result
, unsigned maxlen
)
4240 dm_block_t mapped
, highest
;
4241 char buf
[BDEVNAME_SIZE
];
4242 struct thin_c
*tc
= ti
->private;
4244 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
4253 case STATUSTYPE_INFO
:
4254 r
= dm_thin_get_mapped_count(tc
->td
, &mapped
);
4256 DMERR("dm_thin_get_mapped_count returned %d", r
);
4260 r
= dm_thin_get_highest_mapped_block(tc
->td
, &highest
);
4262 DMERR("dm_thin_get_highest_mapped_block returned %d", r
);
4266 DMEMIT("%llu ", mapped
* tc
->pool
->sectors_per_block
);
4268 DMEMIT("%llu", ((highest
+ 1) *
4269 tc
->pool
->sectors_per_block
) - 1);
4274 case STATUSTYPE_TABLE
:
4276 format_dev_t(buf
, tc
->pool_dev
->bdev
->bd_dev
),
4277 (unsigned long) tc
->dev_id
);
4279 DMEMIT(" %s", format_dev_t(buf
, tc
->origin_dev
->bdev
->bd_dev
));
4290 static int thin_merge(struct dm_target
*ti
, struct bvec_merge_data
*bvm
,
4291 struct bio_vec
*biovec
, int max_size
)
4293 struct thin_c
*tc
= ti
->private;
4294 struct request_queue
*q
= bdev_get_queue(tc
->pool_dev
->bdev
);
4296 if (!q
->merge_bvec_fn
)
4299 bvm
->bi_bdev
= tc
->pool_dev
->bdev
;
4300 bvm
->bi_sector
= dm_target_offset(ti
, bvm
->bi_sector
);
4302 return min(max_size
, q
->merge_bvec_fn(q
, bvm
, biovec
));
4305 static int thin_iterate_devices(struct dm_target
*ti
,
4306 iterate_devices_callout_fn fn
, void *data
)
4309 struct thin_c
*tc
= ti
->private;
4310 struct pool
*pool
= tc
->pool
;
4313 * We can't call dm_pool_get_data_dev_size() since that blocks. So
4314 * we follow a more convoluted path through to the pool's target.
4317 return 0; /* nothing is bound */
4319 blocks
= pool
->ti
->len
;
4320 (void) sector_div(blocks
, pool
->sectors_per_block
);
4322 return fn(ti
, tc
->pool_dev
, 0, pool
->sectors_per_block
* blocks
, data
);
4327 static void thin_io_hints(struct dm_target
*ti
, struct queue_limits
*limits
)
4329 struct thin_c
*tc
= ti
->private;
4330 struct pool
*pool
= tc
->pool
;
4332 limits
->discard_granularity
= pool
->sectors_per_block
<< SECTOR_SHIFT
;
4333 limits
->max_discard_sectors
= 2048 * 1024 * 16; /* 16G */
4336 static struct target_type thin_target
= {
4338 .version
= {1, 16, 0},
4339 .module
= THIS_MODULE
,
4343 .end_io
= thin_endio
,
4344 .preresume
= thin_preresume
,
4345 .presuspend
= thin_presuspend
,
4346 .postsuspend
= thin_postsuspend
,
4347 .status
= thin_status
,
4348 .merge
= thin_merge
,
4349 .iterate_devices
= thin_iterate_devices
,
4350 .io_hints
= thin_io_hints
,
4353 /*----------------------------------------------------------------*/
4355 static int __init
dm_thin_init(void)
4361 r
= dm_register_target(&thin_target
);
4365 r
= dm_register_target(&pool_target
);
4367 goto bad_pool_target
;
4371 _new_mapping_cache
= KMEM_CACHE(dm_thin_new_mapping
, 0);
4372 if (!_new_mapping_cache
)
4373 goto bad_new_mapping_cache
;
4377 bad_new_mapping_cache
:
4378 dm_unregister_target(&pool_target
);
4380 dm_unregister_target(&thin_target
);
4385 static void dm_thin_exit(void)
4387 dm_unregister_target(&thin_target
);
4388 dm_unregister_target(&pool_target
);
4390 kmem_cache_destroy(_new_mapping_cache
);
4393 module_init(dm_thin_init
);
4394 module_exit(dm_thin_exit
);
4396 module_param_named(no_space_timeout
, no_space_timeout_secs
, uint
, S_IRUGO
| S_IWUSR
);
4397 MODULE_PARM_DESC(no_space_timeout
, "Out of data space queue IO timeout in seconds");
4399 MODULE_DESCRIPTION(DM_NAME
" thin provisioning target");
4400 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
4401 MODULE_LICENSE("GPL");