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/sort.h>
22 #include <linux/rbtree.h>
24 #define DM_MSG_PREFIX "thin"
29 #define ENDIO_HOOK_POOL_SIZE 1024
30 #define MAPPING_POOL_SIZE 1024
31 #define COMMIT_PERIOD HZ
32 #define NO_SPACE_TIMEOUT_SECS 60
34 static unsigned no_space_timeout_secs
= NO_SPACE_TIMEOUT_SECS
;
36 DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle
,
37 "A percentage of time allocated for copy on write");
40 * The block size of the device holding pool data must be
41 * between 64KB and 1GB.
43 #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
44 #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
47 * Device id is restricted to 24 bits.
49 #define MAX_DEV_ID ((1 << 24) - 1)
52 * How do we handle breaking sharing of data blocks?
53 * =================================================
55 * We use a standard copy-on-write btree to store the mappings for the
56 * devices (note I'm talking about copy-on-write of the metadata here, not
57 * the data). When you take an internal snapshot you clone the root node
58 * of the origin btree. After this there is no concept of an origin or a
59 * snapshot. They are just two device trees that happen to point to the
62 * When we get a write in we decide if it's to a shared data block using
63 * some timestamp magic. If it is, we have to break sharing.
65 * Let's say we write to a shared block in what was the origin. The
68 * i) plug io further to this physical block. (see bio_prison code).
70 * ii) quiesce any read io to that shared data block. Obviously
71 * including all devices that share this block. (see dm_deferred_set code)
73 * iii) copy the data block to a newly allocate block. This step can be
74 * missed out if the io covers the block. (schedule_copy).
76 * iv) insert the new mapping into the origin's btree
77 * (process_prepared_mapping). This act of inserting breaks some
78 * sharing of btree nodes between the two devices. Breaking sharing only
79 * effects the btree of that specific device. Btrees for the other
80 * devices that share the block never change. The btree for the origin
81 * device as it was after the last commit is untouched, ie. we're using
82 * persistent data structures in the functional programming sense.
84 * v) unplug io to this physical block, including the io that triggered
85 * the breaking of sharing.
87 * Steps (ii) and (iii) occur in parallel.
89 * The metadata _doesn't_ need to be committed before the io continues. We
90 * get away with this because the io is always written to a _new_ block.
91 * If there's a crash, then:
93 * - The origin mapping will point to the old origin block (the shared
94 * one). This will contain the data as it was before the io that triggered
95 * the breaking of sharing came in.
97 * - The snap mapping still points to the old block. As it would after
100 * The downside of this scheme is the timestamp magic isn't perfect, and
101 * will continue to think that data block in the snapshot device is shared
102 * even after the write to the origin has broken sharing. I suspect data
103 * blocks will typically be shared by many different devices, so we're
104 * breaking sharing n + 1 times, rather than n, where n is the number of
105 * devices that reference this data block. At the moment I think the
106 * benefits far, far outweigh the disadvantages.
109 /*----------------------------------------------------------------*/
119 static void build_key(struct dm_thin_device
*td
, enum lock_space ls
,
120 dm_block_t b
, dm_block_t e
, struct dm_cell_key
*key
)
122 key
->virtual = (ls
== VIRTUAL
);
123 key
->dev
= dm_thin_dev_id(td
);
124 key
->block_begin
= b
;
128 static void build_data_key(struct dm_thin_device
*td
, dm_block_t b
,
129 struct dm_cell_key
*key
)
131 build_key(td
, PHYSICAL
, b
, b
+ 1llu, key
);
134 static void build_virtual_key(struct dm_thin_device
*td
, dm_block_t b
,
135 struct dm_cell_key
*key
)
137 build_key(td
, VIRTUAL
, b
, b
+ 1llu, key
);
140 /*----------------------------------------------------------------*/
142 #define THROTTLE_THRESHOLD (1 * HZ)
145 struct rw_semaphore lock
;
146 unsigned long threshold
;
147 bool throttle_applied
;
150 static void throttle_init(struct throttle
*t
)
152 init_rwsem(&t
->lock
);
153 t
->throttle_applied
= false;
156 static void throttle_work_start(struct throttle
*t
)
158 t
->threshold
= jiffies
+ THROTTLE_THRESHOLD
;
161 static void throttle_work_update(struct throttle
*t
)
163 if (!t
->throttle_applied
&& jiffies
> t
->threshold
) {
164 down_write(&t
->lock
);
165 t
->throttle_applied
= true;
169 static void throttle_work_complete(struct throttle
*t
)
171 if (t
->throttle_applied
) {
172 t
->throttle_applied
= false;
177 static void throttle_lock(struct throttle
*t
)
182 static void throttle_unlock(struct throttle
*t
)
187 /*----------------------------------------------------------------*/
190 * A pool device ties together a metadata device and a data device. It
191 * also provides the interface for creating and destroying internal
194 struct dm_thin_new_mapping
;
197 * The pool runs in 4 modes. Ordered in degraded order for comparisons.
200 PM_WRITE
, /* metadata may be changed */
201 PM_OUT_OF_DATA_SPACE
, /* metadata may be changed, though data may not be allocated */
202 PM_READ_ONLY
, /* metadata may not be changed */
203 PM_FAIL
, /* all I/O fails */
206 struct pool_features
{
209 bool zero_new_blocks
:1;
210 bool discard_enabled
:1;
211 bool discard_passdown
:1;
212 bool error_if_no_space
:1;
216 typedef void (*process_bio_fn
)(struct thin_c
*tc
, struct bio
*bio
);
217 typedef void (*process_cell_fn
)(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
);
218 typedef void (*process_mapping_fn
)(struct dm_thin_new_mapping
*m
);
220 #define CELL_SORT_ARRAY_SIZE 8192
223 struct list_head list
;
224 struct dm_target
*ti
; /* Only set if a pool target is bound */
226 struct mapped_device
*pool_md
;
227 struct block_device
*md_dev
;
228 struct dm_pool_metadata
*pmd
;
230 dm_block_t low_water_blocks
;
231 uint32_t sectors_per_block
;
232 int sectors_per_block_shift
;
234 struct pool_features pf
;
235 bool low_water_triggered
:1; /* A dm event has been sent */
238 struct dm_bio_prison
*prison
;
239 struct dm_kcopyd_client
*copier
;
241 struct workqueue_struct
*wq
;
242 struct throttle throttle
;
243 struct work_struct worker
;
244 struct delayed_work waker
;
245 struct delayed_work no_space_timeout
;
247 unsigned long last_commit_jiffies
;
251 struct bio_list deferred_flush_bios
;
252 struct list_head prepared_mappings
;
253 struct list_head prepared_discards
;
254 struct list_head active_thins
;
256 struct dm_deferred_set
*shared_read_ds
;
257 struct dm_deferred_set
*all_io_ds
;
259 struct dm_thin_new_mapping
*next_mapping
;
260 mempool_t
*mapping_pool
;
262 process_bio_fn process_bio
;
263 process_bio_fn process_discard
;
265 process_cell_fn process_cell
;
266 process_cell_fn process_discard_cell
;
268 process_mapping_fn process_prepared_mapping
;
269 process_mapping_fn process_prepared_discard
;
271 struct dm_bio_prison_cell
*cell_sort_array
[CELL_SORT_ARRAY_SIZE
];
274 static enum pool_mode
get_pool_mode(struct pool
*pool
);
275 static void metadata_operation_failed(struct pool
*pool
, const char *op
, int r
);
278 * Target context for a pool.
281 struct dm_target
*ti
;
283 struct dm_dev
*data_dev
;
284 struct dm_dev
*metadata_dev
;
285 struct dm_target_callbacks callbacks
;
287 dm_block_t low_water_blocks
;
288 struct pool_features requested_pf
; /* Features requested during table load */
289 struct pool_features adjusted_pf
; /* Features used after adjusting for constituent devices */
293 * Target context for a thin.
296 struct list_head list
;
297 struct dm_dev
*pool_dev
;
298 struct dm_dev
*origin_dev
;
299 sector_t origin_size
;
303 struct dm_thin_device
*td
;
304 struct mapped_device
*thin_md
;
308 struct list_head deferred_cells
;
309 struct bio_list deferred_bio_list
;
310 struct bio_list retry_on_resume_list
;
311 struct rb_root sort_bio_list
; /* sorted list of deferred bios */
314 * Ensures the thin is not destroyed until the worker has finished
315 * iterating the active_thins list.
318 struct completion can_destroy
;
321 /*----------------------------------------------------------------*/
324 * __blkdev_issue_discard_async - queue a discard with async completion
325 * @bdev: blockdev to issue discard for
326 * @sector: start sector
327 * @nr_sects: number of sectors to discard
328 * @gfp_mask: memory allocation flags (for bio_alloc)
329 * @flags: BLKDEV_IFL_* flags to control behaviour
330 * @parent_bio: parent discard bio that all sub discards get chained to
333 * Asynchronously issue a discard request for the sectors in question.
334 * NOTE: this variant of blk-core's blkdev_issue_discard() is a stop-gap
335 * that is being kept local to DM thinp until the block changes to allow
336 * late bio splitting land upstream.
338 static int __blkdev_issue_discard_async(struct block_device
*bdev
, sector_t sector
,
339 sector_t nr_sects
, gfp_t gfp_mask
, unsigned long flags
,
340 struct bio
*parent_bio
)
342 struct request_queue
*q
= bdev_get_queue(bdev
);
343 int type
= REQ_WRITE
| REQ_DISCARD
;
344 unsigned int max_discard_sectors
, granularity
;
348 struct blk_plug plug
;
353 if (!blk_queue_discard(q
))
356 /* Zero-sector (unknown) and one-sector granularities are the same. */
357 granularity
= max(q
->limits
.discard_granularity
>> 9, 1U);
358 alignment
= (bdev_discard_alignment(bdev
) >> 9) % granularity
;
361 * Ensure that max_discard_sectors is of the proper
362 * granularity, so that requests stay aligned after a split.
364 max_discard_sectors
= min(q
->limits
.max_discard_sectors
, UINT_MAX
>> 9);
365 max_discard_sectors
-= max_discard_sectors
% granularity
;
366 if (unlikely(!max_discard_sectors
)) {
367 /* Avoid infinite loop below. Being cautious never hurts. */
371 if (flags
& BLKDEV_DISCARD_SECURE
) {
372 if (!blk_queue_secdiscard(q
))
377 blk_start_plug(&plug
);
379 unsigned int req_sects
;
380 sector_t end_sect
, tmp
;
383 * Required bio_put occurs in bio_endio thanks to bio_chain below
385 bio
= bio_alloc(gfp_mask
, 1);
391 req_sects
= min_t(sector_t
, nr_sects
, max_discard_sectors
);
394 * If splitting a request, and the next starting sector would be
395 * misaligned, stop the discard at the previous aligned sector.
397 end_sect
= sector
+ req_sects
;
399 if (req_sects
< nr_sects
&&
400 sector_div(tmp
, granularity
) != alignment
) {
401 end_sect
= end_sect
- alignment
;
402 sector_div(end_sect
, granularity
);
403 end_sect
= end_sect
* granularity
+ alignment
;
404 req_sects
= end_sect
- sector
;
407 bio_chain(bio
, parent_bio
);
409 bio
->bi_iter
.bi_sector
= sector
;
412 bio
->bi_iter
.bi_size
= req_sects
<< 9;
413 nr_sects
-= req_sects
;
416 submit_bio(type
, bio
);
419 * We can loop for a long time in here, if someone does
420 * full device discards (like mkfs). Be nice and allow
421 * us to schedule out to avoid softlocking if preempt
426 blk_finish_plug(&plug
);
431 static bool block_size_is_power_of_two(struct pool
*pool
)
433 return pool
->sectors_per_block_shift
>= 0;
436 static sector_t
block_to_sectors(struct pool
*pool
, dm_block_t b
)
438 return block_size_is_power_of_two(pool
) ?
439 (b
<< pool
->sectors_per_block_shift
) :
440 (b
* pool
->sectors_per_block
);
443 static int issue_discard(struct thin_c
*tc
, dm_block_t data_b
, dm_block_t data_e
,
444 struct bio
*parent_bio
)
446 sector_t s
= block_to_sectors(tc
->pool
, data_b
);
447 sector_t len
= block_to_sectors(tc
->pool
, data_e
- data_b
);
449 return __blkdev_issue_discard_async(tc
->pool_dev
->bdev
, s
, len
,
450 GFP_NOWAIT
, 0, parent_bio
);
453 /*----------------------------------------------------------------*/
456 * wake_worker() is used when new work is queued and when pool_resume is
457 * ready to continue deferred IO processing.
459 static void wake_worker(struct pool
*pool
)
461 queue_work(pool
->wq
, &pool
->worker
);
464 /*----------------------------------------------------------------*/
466 static int bio_detain(struct pool
*pool
, struct dm_cell_key
*key
, struct bio
*bio
,
467 struct dm_bio_prison_cell
**cell_result
)
470 struct dm_bio_prison_cell
*cell_prealloc
;
473 * Allocate a cell from the prison's mempool.
474 * This might block but it can't fail.
476 cell_prealloc
= dm_bio_prison_alloc_cell(pool
->prison
, GFP_NOIO
);
478 r
= dm_bio_detain(pool
->prison
, key
, bio
, cell_prealloc
, cell_result
);
481 * We reused an old cell; we can get rid of
484 dm_bio_prison_free_cell(pool
->prison
, cell_prealloc
);
489 static void cell_release(struct pool
*pool
,
490 struct dm_bio_prison_cell
*cell
,
491 struct bio_list
*bios
)
493 dm_cell_release(pool
->prison
, cell
, bios
);
494 dm_bio_prison_free_cell(pool
->prison
, cell
);
497 static void cell_visit_release(struct pool
*pool
,
498 void (*fn
)(void *, struct dm_bio_prison_cell
*),
500 struct dm_bio_prison_cell
*cell
)
502 dm_cell_visit_release(pool
->prison
, fn
, context
, cell
);
503 dm_bio_prison_free_cell(pool
->prison
, cell
);
506 static void cell_release_no_holder(struct pool
*pool
,
507 struct dm_bio_prison_cell
*cell
,
508 struct bio_list
*bios
)
510 dm_cell_release_no_holder(pool
->prison
, cell
, bios
);
511 dm_bio_prison_free_cell(pool
->prison
, cell
);
514 static void cell_error_with_code(struct pool
*pool
,
515 struct dm_bio_prison_cell
*cell
, int error_code
)
517 dm_cell_error(pool
->prison
, cell
, error_code
);
518 dm_bio_prison_free_cell(pool
->prison
, cell
);
521 static void cell_error(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
523 cell_error_with_code(pool
, cell
, -EIO
);
526 static void cell_success(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
528 cell_error_with_code(pool
, cell
, 0);
531 static void cell_requeue(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
533 cell_error_with_code(pool
, cell
, DM_ENDIO_REQUEUE
);
536 /*----------------------------------------------------------------*/
539 * A global list of pools that uses a struct mapped_device as a key.
541 static struct dm_thin_pool_table
{
543 struct list_head pools
;
544 } dm_thin_pool_table
;
546 static void pool_table_init(void)
548 mutex_init(&dm_thin_pool_table
.mutex
);
549 INIT_LIST_HEAD(&dm_thin_pool_table
.pools
);
552 static void __pool_table_insert(struct pool
*pool
)
554 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
555 list_add(&pool
->list
, &dm_thin_pool_table
.pools
);
558 static void __pool_table_remove(struct pool
*pool
)
560 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
561 list_del(&pool
->list
);
564 static struct pool
*__pool_table_lookup(struct mapped_device
*md
)
566 struct pool
*pool
= NULL
, *tmp
;
568 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
570 list_for_each_entry(tmp
, &dm_thin_pool_table
.pools
, list
) {
571 if (tmp
->pool_md
== md
) {
580 static struct pool
*__pool_table_lookup_metadata_dev(struct block_device
*md_dev
)
582 struct pool
*pool
= NULL
, *tmp
;
584 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
586 list_for_each_entry(tmp
, &dm_thin_pool_table
.pools
, list
) {
587 if (tmp
->md_dev
== md_dev
) {
596 /*----------------------------------------------------------------*/
598 struct dm_thin_endio_hook
{
600 struct dm_deferred_entry
*shared_read_entry
;
601 struct dm_deferred_entry
*all_io_entry
;
602 struct dm_thin_new_mapping
*overwrite_mapping
;
603 struct rb_node rb_node
;
604 struct dm_bio_prison_cell
*cell
;
607 static void __merge_bio_list(struct bio_list
*bios
, struct bio_list
*master
)
609 bio_list_merge(bios
, master
);
610 bio_list_init(master
);
613 static void error_bio_list(struct bio_list
*bios
, int error
)
617 while ((bio
= bio_list_pop(bios
)))
618 bio_endio(bio
, error
);
621 static void error_thin_bio_list(struct thin_c
*tc
, struct bio_list
*master
, int error
)
623 struct bio_list bios
;
626 bio_list_init(&bios
);
628 spin_lock_irqsave(&tc
->lock
, flags
);
629 __merge_bio_list(&bios
, master
);
630 spin_unlock_irqrestore(&tc
->lock
, flags
);
632 error_bio_list(&bios
, error
);
635 static void requeue_deferred_cells(struct thin_c
*tc
)
637 struct pool
*pool
= tc
->pool
;
639 struct list_head cells
;
640 struct dm_bio_prison_cell
*cell
, *tmp
;
642 INIT_LIST_HEAD(&cells
);
644 spin_lock_irqsave(&tc
->lock
, flags
);
645 list_splice_init(&tc
->deferred_cells
, &cells
);
646 spin_unlock_irqrestore(&tc
->lock
, flags
);
648 list_for_each_entry_safe(cell
, tmp
, &cells
, user_list
)
649 cell_requeue(pool
, cell
);
652 static void requeue_io(struct thin_c
*tc
)
654 struct bio_list bios
;
657 bio_list_init(&bios
);
659 spin_lock_irqsave(&tc
->lock
, flags
);
660 __merge_bio_list(&bios
, &tc
->deferred_bio_list
);
661 __merge_bio_list(&bios
, &tc
->retry_on_resume_list
);
662 spin_unlock_irqrestore(&tc
->lock
, flags
);
664 error_bio_list(&bios
, DM_ENDIO_REQUEUE
);
665 requeue_deferred_cells(tc
);
668 static void error_retry_list(struct pool
*pool
)
673 list_for_each_entry_rcu(tc
, &pool
->active_thins
, list
)
674 error_thin_bio_list(tc
, &tc
->retry_on_resume_list
, -EIO
);
679 * This section of code contains the logic for processing a thin device's IO.
680 * Much of the code depends on pool object resources (lists, workqueues, etc)
681 * but most is exclusively called from the thin target rather than the thin-pool
685 static dm_block_t
get_bio_block(struct thin_c
*tc
, struct bio
*bio
)
687 struct pool
*pool
= tc
->pool
;
688 sector_t block_nr
= bio
->bi_iter
.bi_sector
;
690 if (block_size_is_power_of_two(pool
))
691 block_nr
>>= pool
->sectors_per_block_shift
;
693 (void) sector_div(block_nr
, pool
->sectors_per_block
);
699 * Returns the _complete_ blocks that this bio covers.
701 static void get_bio_block_range(struct thin_c
*tc
, struct bio
*bio
,
702 dm_block_t
*begin
, dm_block_t
*end
)
704 struct pool
*pool
= tc
->pool
;
705 sector_t b
= bio
->bi_iter
.bi_sector
;
706 sector_t e
= b
+ (bio
->bi_iter
.bi_size
>> SECTOR_SHIFT
);
708 b
+= pool
->sectors_per_block
- 1ull; /* so we round up */
710 if (block_size_is_power_of_two(pool
)) {
711 b
>>= pool
->sectors_per_block_shift
;
712 e
>>= pool
->sectors_per_block_shift
;
714 (void) sector_div(b
, pool
->sectors_per_block
);
715 (void) sector_div(e
, pool
->sectors_per_block
);
719 /* Can happen if the bio is within a single block. */
726 static void remap(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
)
728 struct pool
*pool
= tc
->pool
;
729 sector_t bi_sector
= bio
->bi_iter
.bi_sector
;
731 bio
->bi_bdev
= tc
->pool_dev
->bdev
;
732 if (block_size_is_power_of_two(pool
))
733 bio
->bi_iter
.bi_sector
=
734 (block
<< pool
->sectors_per_block_shift
) |
735 (bi_sector
& (pool
->sectors_per_block
- 1));
737 bio
->bi_iter
.bi_sector
= (block
* pool
->sectors_per_block
) +
738 sector_div(bi_sector
, pool
->sectors_per_block
);
741 static void remap_to_origin(struct thin_c
*tc
, struct bio
*bio
)
743 bio
->bi_bdev
= tc
->origin_dev
->bdev
;
746 static int bio_triggers_commit(struct thin_c
*tc
, struct bio
*bio
)
748 return (bio
->bi_rw
& (REQ_FLUSH
| REQ_FUA
)) &&
749 dm_thin_changed_this_transaction(tc
->td
);
752 static void inc_all_io_entry(struct pool
*pool
, struct bio
*bio
)
754 struct dm_thin_endio_hook
*h
;
756 if (bio
->bi_rw
& REQ_DISCARD
)
759 h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
760 h
->all_io_entry
= dm_deferred_entry_inc(pool
->all_io_ds
);
763 static void issue(struct thin_c
*tc
, struct bio
*bio
)
765 struct pool
*pool
= tc
->pool
;
768 if (!bio_triggers_commit(tc
, bio
)) {
769 generic_make_request(bio
);
774 * Complete bio with an error if earlier I/O caused changes to
775 * the metadata that can't be committed e.g, due to I/O errors
776 * on the metadata device.
778 if (dm_thin_aborted_changes(tc
->td
)) {
784 * Batch together any bios that trigger commits and then issue a
785 * single commit for them in process_deferred_bios().
787 spin_lock_irqsave(&pool
->lock
, flags
);
788 bio_list_add(&pool
->deferred_flush_bios
, bio
);
789 spin_unlock_irqrestore(&pool
->lock
, flags
);
792 static void remap_to_origin_and_issue(struct thin_c
*tc
, struct bio
*bio
)
794 remap_to_origin(tc
, bio
);
798 static void remap_and_issue(struct thin_c
*tc
, struct bio
*bio
,
801 remap(tc
, bio
, block
);
805 /*----------------------------------------------------------------*/
808 * Bio endio functions.
810 struct dm_thin_new_mapping
{
811 struct list_head list
;
817 * Track quiescing, copying and zeroing preparation actions. When this
818 * counter hits zero the block is prepared and can be inserted into the
821 atomic_t prepare_actions
;
825 dm_block_t virt_begin
, virt_end
;
826 dm_block_t data_block
;
827 struct dm_bio_prison_cell
*cell
;
830 * If the bio covers the whole area of a block then we can avoid
831 * zeroing or copying. Instead this bio is hooked. The bio will
832 * still be in the cell, so care has to be taken to avoid issuing
836 bio_end_io_t
*saved_bi_end_io
;
839 static void __complete_mapping_preparation(struct dm_thin_new_mapping
*m
)
841 struct pool
*pool
= m
->tc
->pool
;
843 if (atomic_dec_and_test(&m
->prepare_actions
)) {
844 list_add_tail(&m
->list
, &pool
->prepared_mappings
);
849 static void complete_mapping_preparation(struct dm_thin_new_mapping
*m
)
852 struct pool
*pool
= m
->tc
->pool
;
854 spin_lock_irqsave(&pool
->lock
, flags
);
855 __complete_mapping_preparation(m
);
856 spin_unlock_irqrestore(&pool
->lock
, flags
);
859 static void copy_complete(int read_err
, unsigned long write_err
, void *context
)
861 struct dm_thin_new_mapping
*m
= context
;
863 m
->err
= read_err
|| write_err
? -EIO
: 0;
864 complete_mapping_preparation(m
);
867 static void overwrite_endio(struct bio
*bio
, int err
)
869 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
870 struct dm_thin_new_mapping
*m
= h
->overwrite_mapping
;
872 bio
->bi_end_io
= m
->saved_bi_end_io
;
875 complete_mapping_preparation(m
);
878 /*----------------------------------------------------------------*/
885 * Prepared mapping jobs.
889 * This sends the bios in the cell, except the original holder, back
890 * to the deferred_bios list.
892 static void cell_defer_no_holder(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
894 struct pool
*pool
= tc
->pool
;
897 spin_lock_irqsave(&tc
->lock
, flags
);
898 cell_release_no_holder(pool
, cell
, &tc
->deferred_bio_list
);
899 spin_unlock_irqrestore(&tc
->lock
, flags
);
904 static void thin_defer_bio(struct thin_c
*tc
, struct bio
*bio
);
908 struct bio_list defer_bios
;
909 struct bio_list issue_bios
;
912 static void __inc_remap_and_issue_cell(void *context
,
913 struct dm_bio_prison_cell
*cell
)
915 struct remap_info
*info
= context
;
918 while ((bio
= bio_list_pop(&cell
->bios
))) {
919 if (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
))
920 bio_list_add(&info
->defer_bios
, bio
);
922 inc_all_io_entry(info
->tc
->pool
, bio
);
925 * We can't issue the bios with the bio prison lock
926 * held, so we add them to a list to issue on
927 * return from this function.
929 bio_list_add(&info
->issue_bios
, bio
);
934 static void inc_remap_and_issue_cell(struct thin_c
*tc
,
935 struct dm_bio_prison_cell
*cell
,
939 struct remap_info info
;
942 bio_list_init(&info
.defer_bios
);
943 bio_list_init(&info
.issue_bios
);
946 * We have to be careful to inc any bios we're about to issue
947 * before the cell is released, and avoid a race with new bios
948 * being added to the cell.
950 cell_visit_release(tc
->pool
, __inc_remap_and_issue_cell
,
953 while ((bio
= bio_list_pop(&info
.defer_bios
)))
954 thin_defer_bio(tc
, bio
);
956 while ((bio
= bio_list_pop(&info
.issue_bios
)))
957 remap_and_issue(info
.tc
, bio
, block
);
960 static void process_prepared_mapping_fail(struct dm_thin_new_mapping
*m
)
962 cell_error(m
->tc
->pool
, m
->cell
);
964 mempool_free(m
, m
->tc
->pool
->mapping_pool
);
967 static void process_prepared_mapping(struct dm_thin_new_mapping
*m
)
969 struct thin_c
*tc
= m
->tc
;
970 struct pool
*pool
= tc
->pool
;
971 struct bio
*bio
= m
->bio
;
975 cell_error(pool
, m
->cell
);
980 * Commit the prepared block into the mapping btree.
981 * Any I/O for this block arriving after this point will get
982 * remapped to it directly.
984 r
= dm_thin_insert_block(tc
->td
, m
->virt_begin
, m
->data_block
);
986 metadata_operation_failed(pool
, "dm_thin_insert_block", r
);
987 cell_error(pool
, m
->cell
);
992 * Release any bios held while the block was being provisioned.
993 * If we are processing a write bio that completely covers the block,
994 * we already processed it so can ignore it now when processing
995 * the bios in the cell.
998 inc_remap_and_issue_cell(tc
, m
->cell
, m
->data_block
);
1001 inc_all_io_entry(tc
->pool
, m
->cell
->holder
);
1002 remap_and_issue(tc
, m
->cell
->holder
, m
->data_block
);
1003 inc_remap_and_issue_cell(tc
, m
->cell
, m
->data_block
);
1008 mempool_free(m
, pool
->mapping_pool
);
1011 /*----------------------------------------------------------------*/
1013 static void free_discard_mapping(struct dm_thin_new_mapping
*m
)
1015 struct thin_c
*tc
= m
->tc
;
1017 cell_defer_no_holder(tc
, m
->cell
);
1018 mempool_free(m
, tc
->pool
->mapping_pool
);
1021 static void process_prepared_discard_fail(struct dm_thin_new_mapping
*m
)
1023 bio_io_error(m
->bio
);
1024 free_discard_mapping(m
);
1027 static void process_prepared_discard_success(struct dm_thin_new_mapping
*m
)
1029 bio_endio(m
->bio
, 0);
1030 free_discard_mapping(m
);
1033 static void process_prepared_discard_no_passdown(struct dm_thin_new_mapping
*m
)
1036 struct thin_c
*tc
= m
->tc
;
1038 r
= dm_thin_remove_range(tc
->td
, m
->cell
->key
.block_begin
, m
->cell
->key
.block_end
);
1040 metadata_operation_failed(tc
->pool
, "dm_thin_remove_range", r
);
1041 bio_io_error(m
->bio
);
1043 bio_endio(m
->bio
, 0);
1045 cell_defer_no_holder(tc
, m
->cell
);
1046 mempool_free(m
, tc
->pool
->mapping_pool
);
1049 static int passdown_double_checking_shared_status(struct dm_thin_new_mapping
*m
)
1052 * We've already unmapped this range of blocks, but before we
1053 * passdown we have to check that these blocks are now unused.
1057 struct thin_c
*tc
= m
->tc
;
1058 struct pool
*pool
= tc
->pool
;
1059 dm_block_t b
= m
->data_block
, e
, end
= m
->data_block
+ m
->virt_end
- m
->virt_begin
;
1062 /* find start of unmapped run */
1063 for (; b
< end
; b
++) {
1064 r
= dm_pool_block_is_used(pool
->pmd
, b
, &used
);
1075 /* find end of run */
1076 for (e
= b
+ 1; e
!= end
; e
++) {
1077 r
= dm_pool_block_is_used(pool
->pmd
, e
, &used
);
1085 r
= issue_discard(tc
, b
, e
, m
->bio
);
1095 static void process_prepared_discard_passdown(struct dm_thin_new_mapping
*m
)
1098 struct thin_c
*tc
= m
->tc
;
1099 struct pool
*pool
= tc
->pool
;
1101 r
= dm_thin_remove_range(tc
->td
, m
->virt_begin
, m
->virt_end
);
1103 metadata_operation_failed(pool
, "dm_thin_remove_range", r
);
1105 else if (m
->maybe_shared
)
1106 r
= passdown_double_checking_shared_status(m
);
1108 r
= issue_discard(tc
, m
->data_block
, m
->data_block
+ (m
->virt_end
- m
->virt_begin
), m
->bio
);
1111 * Even if r is set, there could be sub discards in flight that we
1114 bio_endio(m
->bio
, r
);
1115 cell_defer_no_holder(tc
, m
->cell
);
1116 mempool_free(m
, pool
->mapping_pool
);
1119 static void process_prepared(struct pool
*pool
, struct list_head
*head
,
1120 process_mapping_fn
*fn
)
1122 unsigned long flags
;
1123 struct list_head maps
;
1124 struct dm_thin_new_mapping
*m
, *tmp
;
1126 INIT_LIST_HEAD(&maps
);
1127 spin_lock_irqsave(&pool
->lock
, flags
);
1128 list_splice_init(head
, &maps
);
1129 spin_unlock_irqrestore(&pool
->lock
, flags
);
1131 list_for_each_entry_safe(m
, tmp
, &maps
, list
)
1136 * Deferred bio jobs.
1138 static int io_overlaps_block(struct pool
*pool
, struct bio
*bio
)
1140 return bio
->bi_iter
.bi_size
==
1141 (pool
->sectors_per_block
<< SECTOR_SHIFT
);
1144 static int io_overwrites_block(struct pool
*pool
, struct bio
*bio
)
1146 return (bio_data_dir(bio
) == WRITE
) &&
1147 io_overlaps_block(pool
, bio
);
1150 static void save_and_set_endio(struct bio
*bio
, bio_end_io_t
**save
,
1153 *save
= bio
->bi_end_io
;
1154 bio
->bi_end_io
= fn
;
1157 static int ensure_next_mapping(struct pool
*pool
)
1159 if (pool
->next_mapping
)
1162 pool
->next_mapping
= mempool_alloc(pool
->mapping_pool
, GFP_ATOMIC
);
1164 return pool
->next_mapping
? 0 : -ENOMEM
;
1167 static struct dm_thin_new_mapping
*get_next_mapping(struct pool
*pool
)
1169 struct dm_thin_new_mapping
*m
= pool
->next_mapping
;
1171 BUG_ON(!pool
->next_mapping
);
1173 memset(m
, 0, sizeof(struct dm_thin_new_mapping
));
1174 INIT_LIST_HEAD(&m
->list
);
1177 pool
->next_mapping
= NULL
;
1182 static void ll_zero(struct thin_c
*tc
, struct dm_thin_new_mapping
*m
,
1183 sector_t begin
, sector_t end
)
1186 struct dm_io_region to
;
1188 to
.bdev
= tc
->pool_dev
->bdev
;
1190 to
.count
= end
- begin
;
1192 r
= dm_kcopyd_zero(tc
->pool
->copier
, 1, &to
, 0, copy_complete
, m
);
1194 DMERR_LIMIT("dm_kcopyd_zero() failed");
1195 copy_complete(1, 1, m
);
1199 static void remap_and_issue_overwrite(struct thin_c
*tc
, struct bio
*bio
,
1200 dm_block_t data_begin
,
1201 struct dm_thin_new_mapping
*m
)
1203 struct pool
*pool
= tc
->pool
;
1204 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1206 h
->overwrite_mapping
= m
;
1208 save_and_set_endio(bio
, &m
->saved_bi_end_io
, overwrite_endio
);
1209 inc_all_io_entry(pool
, bio
);
1210 remap_and_issue(tc
, bio
, data_begin
);
1214 * A partial copy also needs to zero the uncopied region.
1216 static void schedule_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1217 struct dm_dev
*origin
, dm_block_t data_origin
,
1218 dm_block_t data_dest
,
1219 struct dm_bio_prison_cell
*cell
, struct bio
*bio
,
1223 struct pool
*pool
= tc
->pool
;
1224 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1227 m
->virt_begin
= virt_block
;
1228 m
->virt_end
= virt_block
+ 1u;
1229 m
->data_block
= data_dest
;
1233 * quiesce action + copy action + an extra reference held for the
1234 * duration of this function (we may need to inc later for a
1237 atomic_set(&m
->prepare_actions
, 3);
1239 if (!dm_deferred_set_add_work(pool
->shared_read_ds
, &m
->list
))
1240 complete_mapping_preparation(m
); /* already quiesced */
1243 * IO to pool_dev remaps to the pool target's data_dev.
1245 * If the whole block of data is being overwritten, we can issue the
1246 * bio immediately. Otherwise we use kcopyd to clone the data first.
1248 if (io_overwrites_block(pool
, bio
))
1249 remap_and_issue_overwrite(tc
, bio
, data_dest
, m
);
1251 struct dm_io_region from
, to
;
1253 from
.bdev
= origin
->bdev
;
1254 from
.sector
= data_origin
* pool
->sectors_per_block
;
1257 to
.bdev
= tc
->pool_dev
->bdev
;
1258 to
.sector
= data_dest
* pool
->sectors_per_block
;
1261 r
= dm_kcopyd_copy(pool
->copier
, &from
, 1, &to
,
1262 0, copy_complete
, m
);
1264 DMERR_LIMIT("dm_kcopyd_copy() failed");
1265 copy_complete(1, 1, m
);
1268 * We allow the zero to be issued, to simplify the
1269 * error path. Otherwise we'd need to start
1270 * worrying about decrementing the prepare_actions
1276 * Do we need to zero a tail region?
1278 if (len
< pool
->sectors_per_block
&& pool
->pf
.zero_new_blocks
) {
1279 atomic_inc(&m
->prepare_actions
);
1281 data_dest
* pool
->sectors_per_block
+ len
,
1282 (data_dest
+ 1) * pool
->sectors_per_block
);
1286 complete_mapping_preparation(m
); /* drop our ref */
1289 static void schedule_internal_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1290 dm_block_t data_origin
, dm_block_t data_dest
,
1291 struct dm_bio_prison_cell
*cell
, struct bio
*bio
)
1293 schedule_copy(tc
, virt_block
, tc
->pool_dev
,
1294 data_origin
, data_dest
, cell
, bio
,
1295 tc
->pool
->sectors_per_block
);
1298 static void schedule_zero(struct thin_c
*tc
, dm_block_t virt_block
,
1299 dm_block_t data_block
, struct dm_bio_prison_cell
*cell
,
1302 struct pool
*pool
= tc
->pool
;
1303 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1305 atomic_set(&m
->prepare_actions
, 1); /* no need to quiesce */
1307 m
->virt_begin
= virt_block
;
1308 m
->virt_end
= virt_block
+ 1u;
1309 m
->data_block
= data_block
;
1313 * If the whole block of data is being overwritten or we are not
1314 * zeroing pre-existing data, we can issue the bio immediately.
1315 * Otherwise we use kcopyd to zero the data first.
1317 if (pool
->pf
.zero_new_blocks
) {
1318 if (io_overwrites_block(pool
, bio
))
1319 remap_and_issue_overwrite(tc
, bio
, data_block
, m
);
1321 ll_zero(tc
, m
, data_block
* pool
->sectors_per_block
,
1322 (data_block
+ 1) * pool
->sectors_per_block
);
1324 process_prepared_mapping(m
);
1327 static void schedule_external_copy(struct thin_c
*tc
, dm_block_t virt_block
,
1328 dm_block_t data_dest
,
1329 struct dm_bio_prison_cell
*cell
, struct bio
*bio
)
1331 struct pool
*pool
= tc
->pool
;
1332 sector_t virt_block_begin
= virt_block
* pool
->sectors_per_block
;
1333 sector_t virt_block_end
= (virt_block
+ 1) * pool
->sectors_per_block
;
1335 if (virt_block_end
<= tc
->origin_size
)
1336 schedule_copy(tc
, virt_block
, tc
->origin_dev
,
1337 virt_block
, data_dest
, cell
, bio
,
1338 pool
->sectors_per_block
);
1340 else if (virt_block_begin
< tc
->origin_size
)
1341 schedule_copy(tc
, virt_block
, tc
->origin_dev
,
1342 virt_block
, data_dest
, cell
, bio
,
1343 tc
->origin_size
- virt_block_begin
);
1346 schedule_zero(tc
, virt_block
, data_dest
, cell
, bio
);
1349 static void set_pool_mode(struct pool
*pool
, enum pool_mode new_mode
);
1351 static void check_for_space(struct pool
*pool
)
1356 if (get_pool_mode(pool
) != PM_OUT_OF_DATA_SPACE
)
1359 r
= dm_pool_get_free_block_count(pool
->pmd
, &nr_free
);
1364 set_pool_mode(pool
, PM_WRITE
);
1368 * A non-zero return indicates read_only or fail_io mode.
1369 * Many callers don't care about the return value.
1371 static int commit(struct pool
*pool
)
1375 if (get_pool_mode(pool
) >= PM_READ_ONLY
)
1378 r
= dm_pool_commit_metadata(pool
->pmd
);
1380 metadata_operation_failed(pool
, "dm_pool_commit_metadata", r
);
1382 check_for_space(pool
);
1387 static void check_low_water_mark(struct pool
*pool
, dm_block_t free_blocks
)
1389 unsigned long flags
;
1391 if (free_blocks
<= pool
->low_water_blocks
&& !pool
->low_water_triggered
) {
1392 DMWARN("%s: reached low water mark for data device: sending event.",
1393 dm_device_name(pool
->pool_md
));
1394 spin_lock_irqsave(&pool
->lock
, flags
);
1395 pool
->low_water_triggered
= true;
1396 spin_unlock_irqrestore(&pool
->lock
, flags
);
1397 dm_table_event(pool
->ti
->table
);
1401 static int alloc_data_block(struct thin_c
*tc
, dm_block_t
*result
)
1404 dm_block_t free_blocks
;
1405 struct pool
*pool
= tc
->pool
;
1407 if (WARN_ON(get_pool_mode(pool
) != PM_WRITE
))
1410 r
= dm_pool_get_free_block_count(pool
->pmd
, &free_blocks
);
1412 metadata_operation_failed(pool
, "dm_pool_get_free_block_count", r
);
1416 check_low_water_mark(pool
, free_blocks
);
1420 * Try to commit to see if that will free up some
1427 r
= dm_pool_get_free_block_count(pool
->pmd
, &free_blocks
);
1429 metadata_operation_failed(pool
, "dm_pool_get_free_block_count", r
);
1434 set_pool_mode(pool
, PM_OUT_OF_DATA_SPACE
);
1439 r
= dm_pool_alloc_data_block(pool
->pmd
, result
);
1441 metadata_operation_failed(pool
, "dm_pool_alloc_data_block", r
);
1449 * If we have run out of space, queue bios until the device is
1450 * resumed, presumably after having been reloaded with more space.
1452 static void retry_on_resume(struct bio
*bio
)
1454 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1455 struct thin_c
*tc
= h
->tc
;
1456 unsigned long flags
;
1458 spin_lock_irqsave(&tc
->lock
, flags
);
1459 bio_list_add(&tc
->retry_on_resume_list
, bio
);
1460 spin_unlock_irqrestore(&tc
->lock
, flags
);
1463 static int should_error_unserviceable_bio(struct pool
*pool
)
1465 enum pool_mode m
= get_pool_mode(pool
);
1469 /* Shouldn't get here */
1470 DMERR_LIMIT("bio unserviceable, yet pool is in PM_WRITE mode");
1473 case PM_OUT_OF_DATA_SPACE
:
1474 return pool
->pf
.error_if_no_space
? -ENOSPC
: 0;
1480 /* Shouldn't get here */
1481 DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode");
1486 static void handle_unserviceable_bio(struct pool
*pool
, struct bio
*bio
)
1488 int error
= should_error_unserviceable_bio(pool
);
1491 bio_endio(bio
, error
);
1493 retry_on_resume(bio
);
1496 static void retry_bios_on_resume(struct pool
*pool
, struct dm_bio_prison_cell
*cell
)
1499 struct bio_list bios
;
1502 error
= should_error_unserviceable_bio(pool
);
1504 cell_error_with_code(pool
, cell
, error
);
1508 bio_list_init(&bios
);
1509 cell_release(pool
, cell
, &bios
);
1511 while ((bio
= bio_list_pop(&bios
)))
1512 retry_on_resume(bio
);
1515 static void process_discard_cell_no_passdown(struct thin_c
*tc
,
1516 struct dm_bio_prison_cell
*virt_cell
)
1518 struct pool
*pool
= tc
->pool
;
1519 struct dm_thin_new_mapping
*m
= get_next_mapping(pool
);
1522 * We don't need to lock the data blocks, since there's no
1523 * passdown. We only lock data blocks for allocation and breaking sharing.
1526 m
->virt_begin
= virt_cell
->key
.block_begin
;
1527 m
->virt_end
= virt_cell
->key
.block_end
;
1528 m
->cell
= virt_cell
;
1529 m
->bio
= virt_cell
->holder
;
1531 if (!dm_deferred_set_add_work(pool
->all_io_ds
, &m
->list
))
1532 pool
->process_prepared_discard(m
);
1536 * FIXME: DM local hack to defer parent bios's end_io until we
1537 * _know_ all chained sub range discard bios have completed.
1538 * Will go away once late bio splitting lands upstream!
1540 static inline void __bio_inc_remaining(struct bio
*bio
)
1542 bio
->bi_flags
|= (1 << BIO_CHAIN
);
1543 smp_mb__before_atomic();
1544 atomic_inc(&bio
->__bi_remaining
);
1547 static void break_up_discard_bio(struct thin_c
*tc
, dm_block_t begin
, dm_block_t end
,
1550 struct pool
*pool
= tc
->pool
;
1554 struct dm_cell_key data_key
;
1555 struct dm_bio_prison_cell
*data_cell
;
1556 struct dm_thin_new_mapping
*m
;
1557 dm_block_t virt_begin
, virt_end
, data_begin
;
1559 while (begin
!= end
) {
1560 r
= ensure_next_mapping(pool
);
1562 /* we did our best */
1565 r
= dm_thin_find_mapped_range(tc
->td
, begin
, end
, &virt_begin
, &virt_end
,
1566 &data_begin
, &maybe_shared
);
1569 * Silently fail, letting any mappings we've
1574 build_key(tc
->td
, PHYSICAL
, data_begin
, data_begin
+ (virt_end
- virt_begin
), &data_key
);
1575 if (bio_detain(tc
->pool
, &data_key
, NULL
, &data_cell
)) {
1576 /* contention, we'll give up with this range */
1582 * IO may still be going to the destination block. We must
1583 * quiesce before we can do the removal.
1585 m
= get_next_mapping(pool
);
1587 m
->maybe_shared
= maybe_shared
;
1588 m
->virt_begin
= virt_begin
;
1589 m
->virt_end
= virt_end
;
1590 m
->data_block
= data_begin
;
1591 m
->cell
= data_cell
;
1595 * The parent bio must not complete before sub discard bios are
1596 * chained to it (see __blkdev_issue_discard_async's bio_chain)!
1598 * This per-mapping bi_remaining increment is paired with
1599 * the implicit decrement that occurs via bio_endio() in
1600 * process_prepared_discard_{passdown,no_passdown}.
1602 __bio_inc_remaining(bio
);
1603 if (!dm_deferred_set_add_work(pool
->all_io_ds
, &m
->list
))
1604 pool
->process_prepared_discard(m
);
1610 static void process_discard_cell_passdown(struct thin_c
*tc
, struct dm_bio_prison_cell
*virt_cell
)
1612 struct bio
*bio
= virt_cell
->holder
;
1613 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1616 * The virt_cell will only get freed once the origin bio completes.
1617 * This means it will remain locked while all the individual
1618 * passdown bios are in flight.
1620 h
->cell
= virt_cell
;
1621 break_up_discard_bio(tc
, virt_cell
->key
.block_begin
, virt_cell
->key
.block_end
, bio
);
1624 * We complete the bio now, knowing that the bi_remaining field
1625 * will prevent completion until the sub range discards have
1631 static void process_discard_bio(struct thin_c
*tc
, struct bio
*bio
)
1633 dm_block_t begin
, end
;
1634 struct dm_cell_key virt_key
;
1635 struct dm_bio_prison_cell
*virt_cell
;
1637 get_bio_block_range(tc
, bio
, &begin
, &end
);
1640 * The discard covers less than a block.
1646 build_key(tc
->td
, VIRTUAL
, begin
, end
, &virt_key
);
1647 if (bio_detain(tc
->pool
, &virt_key
, bio
, &virt_cell
))
1649 * Potential starvation issue: We're relying on the
1650 * fs/application being well behaved, and not trying to
1651 * send IO to a region at the same time as discarding it.
1652 * If they do this persistently then it's possible this
1653 * cell will never be granted.
1657 tc
->pool
->process_discard_cell(tc
, virt_cell
);
1660 static void break_sharing(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
,
1661 struct dm_cell_key
*key
,
1662 struct dm_thin_lookup_result
*lookup_result
,
1663 struct dm_bio_prison_cell
*cell
)
1666 dm_block_t data_block
;
1667 struct pool
*pool
= tc
->pool
;
1669 r
= alloc_data_block(tc
, &data_block
);
1672 schedule_internal_copy(tc
, block
, lookup_result
->block
,
1673 data_block
, cell
, bio
);
1677 retry_bios_on_resume(pool
, cell
);
1681 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1683 cell_error(pool
, cell
);
1688 static void __remap_and_issue_shared_cell(void *context
,
1689 struct dm_bio_prison_cell
*cell
)
1691 struct remap_info
*info
= context
;
1694 while ((bio
= bio_list_pop(&cell
->bios
))) {
1695 if ((bio_data_dir(bio
) == WRITE
) ||
1696 (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
)))
1697 bio_list_add(&info
->defer_bios
, bio
);
1699 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));;
1701 h
->shared_read_entry
= dm_deferred_entry_inc(info
->tc
->pool
->shared_read_ds
);
1702 inc_all_io_entry(info
->tc
->pool
, bio
);
1703 bio_list_add(&info
->issue_bios
, bio
);
1708 static void remap_and_issue_shared_cell(struct thin_c
*tc
,
1709 struct dm_bio_prison_cell
*cell
,
1713 struct remap_info info
;
1716 bio_list_init(&info
.defer_bios
);
1717 bio_list_init(&info
.issue_bios
);
1719 cell_visit_release(tc
->pool
, __remap_and_issue_shared_cell
,
1722 while ((bio
= bio_list_pop(&info
.defer_bios
)))
1723 thin_defer_bio(tc
, bio
);
1725 while ((bio
= bio_list_pop(&info
.issue_bios
)))
1726 remap_and_issue(tc
, bio
, block
);
1729 static void process_shared_bio(struct thin_c
*tc
, struct bio
*bio
,
1731 struct dm_thin_lookup_result
*lookup_result
,
1732 struct dm_bio_prison_cell
*virt_cell
)
1734 struct dm_bio_prison_cell
*data_cell
;
1735 struct pool
*pool
= tc
->pool
;
1736 struct dm_cell_key key
;
1739 * If cell is already occupied, then sharing is already in the process
1740 * of being broken so we have nothing further to do here.
1742 build_data_key(tc
->td
, lookup_result
->block
, &key
);
1743 if (bio_detain(pool
, &key
, bio
, &data_cell
)) {
1744 cell_defer_no_holder(tc
, virt_cell
);
1748 if (bio_data_dir(bio
) == WRITE
&& bio
->bi_iter
.bi_size
) {
1749 break_sharing(tc
, bio
, block
, &key
, lookup_result
, data_cell
);
1750 cell_defer_no_holder(tc
, virt_cell
);
1752 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1754 h
->shared_read_entry
= dm_deferred_entry_inc(pool
->shared_read_ds
);
1755 inc_all_io_entry(pool
, bio
);
1756 remap_and_issue(tc
, bio
, lookup_result
->block
);
1758 remap_and_issue_shared_cell(tc
, data_cell
, lookup_result
->block
);
1759 remap_and_issue_shared_cell(tc
, virt_cell
, lookup_result
->block
);
1763 static void provision_block(struct thin_c
*tc
, struct bio
*bio
, dm_block_t block
,
1764 struct dm_bio_prison_cell
*cell
)
1767 dm_block_t data_block
;
1768 struct pool
*pool
= tc
->pool
;
1771 * Remap empty bios (flushes) immediately, without provisioning.
1773 if (!bio
->bi_iter
.bi_size
) {
1774 inc_all_io_entry(pool
, bio
);
1775 cell_defer_no_holder(tc
, cell
);
1777 remap_and_issue(tc
, bio
, 0);
1782 * Fill read bios with zeroes and complete them immediately.
1784 if (bio_data_dir(bio
) == READ
) {
1786 cell_defer_no_holder(tc
, cell
);
1791 r
= alloc_data_block(tc
, &data_block
);
1795 schedule_external_copy(tc
, block
, data_block
, cell
, bio
);
1797 schedule_zero(tc
, block
, data_block
, cell
, bio
);
1801 retry_bios_on_resume(pool
, cell
);
1805 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1807 cell_error(pool
, cell
);
1812 static void process_cell(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1815 struct pool
*pool
= tc
->pool
;
1816 struct bio
*bio
= cell
->holder
;
1817 dm_block_t block
= get_bio_block(tc
, bio
);
1818 struct dm_thin_lookup_result lookup_result
;
1820 if (tc
->requeue_mode
) {
1821 cell_requeue(pool
, cell
);
1825 r
= dm_thin_find_block(tc
->td
, block
, 1, &lookup_result
);
1828 if (lookup_result
.shared
)
1829 process_shared_bio(tc
, bio
, block
, &lookup_result
, cell
);
1831 inc_all_io_entry(pool
, bio
);
1832 remap_and_issue(tc
, bio
, lookup_result
.block
);
1833 inc_remap_and_issue_cell(tc
, cell
, lookup_result
.block
);
1838 if (bio_data_dir(bio
) == READ
&& tc
->origin_dev
) {
1839 inc_all_io_entry(pool
, bio
);
1840 cell_defer_no_holder(tc
, cell
);
1842 if (bio_end_sector(bio
) <= tc
->origin_size
)
1843 remap_to_origin_and_issue(tc
, bio
);
1845 else if (bio
->bi_iter
.bi_sector
< tc
->origin_size
) {
1847 bio
->bi_iter
.bi_size
= (tc
->origin_size
- bio
->bi_iter
.bi_sector
) << SECTOR_SHIFT
;
1848 remap_to_origin_and_issue(tc
, bio
);
1855 provision_block(tc
, bio
, block
, cell
);
1859 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1861 cell_defer_no_holder(tc
, cell
);
1867 static void process_bio(struct thin_c
*tc
, struct bio
*bio
)
1869 struct pool
*pool
= tc
->pool
;
1870 dm_block_t block
= get_bio_block(tc
, bio
);
1871 struct dm_bio_prison_cell
*cell
;
1872 struct dm_cell_key key
;
1875 * If cell is already occupied, then the block is already
1876 * being provisioned so we have nothing further to do here.
1878 build_virtual_key(tc
->td
, block
, &key
);
1879 if (bio_detain(pool
, &key
, bio
, &cell
))
1882 process_cell(tc
, cell
);
1885 static void __process_bio_read_only(struct thin_c
*tc
, struct bio
*bio
,
1886 struct dm_bio_prison_cell
*cell
)
1889 int rw
= bio_data_dir(bio
);
1890 dm_block_t block
= get_bio_block(tc
, bio
);
1891 struct dm_thin_lookup_result lookup_result
;
1893 r
= dm_thin_find_block(tc
->td
, block
, 1, &lookup_result
);
1896 if (lookup_result
.shared
&& (rw
== WRITE
) && bio
->bi_iter
.bi_size
) {
1897 handle_unserviceable_bio(tc
->pool
, bio
);
1899 cell_defer_no_holder(tc
, cell
);
1901 inc_all_io_entry(tc
->pool
, bio
);
1902 remap_and_issue(tc
, bio
, lookup_result
.block
);
1904 inc_remap_and_issue_cell(tc
, cell
, lookup_result
.block
);
1910 cell_defer_no_holder(tc
, cell
);
1912 handle_unserviceable_bio(tc
->pool
, bio
);
1916 if (tc
->origin_dev
) {
1917 inc_all_io_entry(tc
->pool
, bio
);
1918 remap_to_origin_and_issue(tc
, bio
);
1927 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1930 cell_defer_no_holder(tc
, cell
);
1936 static void process_bio_read_only(struct thin_c
*tc
, struct bio
*bio
)
1938 __process_bio_read_only(tc
, bio
, NULL
);
1941 static void process_cell_read_only(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1943 __process_bio_read_only(tc
, cell
->holder
, cell
);
1946 static void process_bio_success(struct thin_c
*tc
, struct bio
*bio
)
1951 static void process_bio_fail(struct thin_c
*tc
, struct bio
*bio
)
1956 static void process_cell_success(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1958 cell_success(tc
->pool
, cell
);
1961 static void process_cell_fail(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
1963 cell_error(tc
->pool
, cell
);
1967 * FIXME: should we also commit due to size of transaction, measured in
1970 static int need_commit_due_to_time(struct pool
*pool
)
1972 return !time_in_range(jiffies
, pool
->last_commit_jiffies
,
1973 pool
->last_commit_jiffies
+ COMMIT_PERIOD
);
1976 #define thin_pbd(node) rb_entry((node), struct dm_thin_endio_hook, rb_node)
1977 #define thin_bio(pbd) dm_bio_from_per_bio_data((pbd), sizeof(struct dm_thin_endio_hook))
1979 static void __thin_bio_rb_add(struct thin_c
*tc
, struct bio
*bio
)
1981 struct rb_node
**rbp
, *parent
;
1982 struct dm_thin_endio_hook
*pbd
;
1983 sector_t bi_sector
= bio
->bi_iter
.bi_sector
;
1985 rbp
= &tc
->sort_bio_list
.rb_node
;
1989 pbd
= thin_pbd(parent
);
1991 if (bi_sector
< thin_bio(pbd
)->bi_iter
.bi_sector
)
1992 rbp
= &(*rbp
)->rb_left
;
1994 rbp
= &(*rbp
)->rb_right
;
1997 pbd
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
1998 rb_link_node(&pbd
->rb_node
, parent
, rbp
);
1999 rb_insert_color(&pbd
->rb_node
, &tc
->sort_bio_list
);
2002 static void __extract_sorted_bios(struct thin_c
*tc
)
2004 struct rb_node
*node
;
2005 struct dm_thin_endio_hook
*pbd
;
2008 for (node
= rb_first(&tc
->sort_bio_list
); node
; node
= rb_next(node
)) {
2009 pbd
= thin_pbd(node
);
2010 bio
= thin_bio(pbd
);
2012 bio_list_add(&tc
->deferred_bio_list
, bio
);
2013 rb_erase(&pbd
->rb_node
, &tc
->sort_bio_list
);
2016 WARN_ON(!RB_EMPTY_ROOT(&tc
->sort_bio_list
));
2019 static void __sort_thin_deferred_bios(struct thin_c
*tc
)
2022 struct bio_list bios
;
2024 bio_list_init(&bios
);
2025 bio_list_merge(&bios
, &tc
->deferred_bio_list
);
2026 bio_list_init(&tc
->deferred_bio_list
);
2028 /* Sort deferred_bio_list using rb-tree */
2029 while ((bio
= bio_list_pop(&bios
)))
2030 __thin_bio_rb_add(tc
, bio
);
2033 * Transfer the sorted bios in sort_bio_list back to
2034 * deferred_bio_list to allow lockless submission of
2037 __extract_sorted_bios(tc
);
2040 static void process_thin_deferred_bios(struct thin_c
*tc
)
2042 struct pool
*pool
= tc
->pool
;
2043 unsigned long flags
;
2045 struct bio_list bios
;
2046 struct blk_plug plug
;
2049 if (tc
->requeue_mode
) {
2050 error_thin_bio_list(tc
, &tc
->deferred_bio_list
, DM_ENDIO_REQUEUE
);
2054 bio_list_init(&bios
);
2056 spin_lock_irqsave(&tc
->lock
, flags
);
2058 if (bio_list_empty(&tc
->deferred_bio_list
)) {
2059 spin_unlock_irqrestore(&tc
->lock
, flags
);
2063 __sort_thin_deferred_bios(tc
);
2065 bio_list_merge(&bios
, &tc
->deferred_bio_list
);
2066 bio_list_init(&tc
->deferred_bio_list
);
2068 spin_unlock_irqrestore(&tc
->lock
, flags
);
2070 blk_start_plug(&plug
);
2071 while ((bio
= bio_list_pop(&bios
))) {
2073 * If we've got no free new_mapping structs, and processing
2074 * this bio might require one, we pause until there are some
2075 * prepared mappings to process.
2077 if (ensure_next_mapping(pool
)) {
2078 spin_lock_irqsave(&tc
->lock
, flags
);
2079 bio_list_add(&tc
->deferred_bio_list
, bio
);
2080 bio_list_merge(&tc
->deferred_bio_list
, &bios
);
2081 spin_unlock_irqrestore(&tc
->lock
, flags
);
2085 if (bio
->bi_rw
& REQ_DISCARD
)
2086 pool
->process_discard(tc
, bio
);
2088 pool
->process_bio(tc
, bio
);
2090 if ((count
++ & 127) == 0) {
2091 throttle_work_update(&pool
->throttle
);
2092 dm_pool_issue_prefetches(pool
->pmd
);
2095 blk_finish_plug(&plug
);
2098 static int cmp_cells(const void *lhs
, const void *rhs
)
2100 struct dm_bio_prison_cell
*lhs_cell
= *((struct dm_bio_prison_cell
**) lhs
);
2101 struct dm_bio_prison_cell
*rhs_cell
= *((struct dm_bio_prison_cell
**) rhs
);
2103 BUG_ON(!lhs_cell
->holder
);
2104 BUG_ON(!rhs_cell
->holder
);
2106 if (lhs_cell
->holder
->bi_iter
.bi_sector
< rhs_cell
->holder
->bi_iter
.bi_sector
)
2109 if (lhs_cell
->holder
->bi_iter
.bi_sector
> rhs_cell
->holder
->bi_iter
.bi_sector
)
2115 static unsigned sort_cells(struct pool
*pool
, struct list_head
*cells
)
2118 struct dm_bio_prison_cell
*cell
, *tmp
;
2120 list_for_each_entry_safe(cell
, tmp
, cells
, user_list
) {
2121 if (count
>= CELL_SORT_ARRAY_SIZE
)
2124 pool
->cell_sort_array
[count
++] = cell
;
2125 list_del(&cell
->user_list
);
2128 sort(pool
->cell_sort_array
, count
, sizeof(cell
), cmp_cells
, NULL
);
2133 static void process_thin_deferred_cells(struct thin_c
*tc
)
2135 struct pool
*pool
= tc
->pool
;
2136 unsigned long flags
;
2137 struct list_head cells
;
2138 struct dm_bio_prison_cell
*cell
;
2139 unsigned i
, j
, count
;
2141 INIT_LIST_HEAD(&cells
);
2143 spin_lock_irqsave(&tc
->lock
, flags
);
2144 list_splice_init(&tc
->deferred_cells
, &cells
);
2145 spin_unlock_irqrestore(&tc
->lock
, flags
);
2147 if (list_empty(&cells
))
2151 count
= sort_cells(tc
->pool
, &cells
);
2153 for (i
= 0; i
< count
; i
++) {
2154 cell
= pool
->cell_sort_array
[i
];
2155 BUG_ON(!cell
->holder
);
2158 * If we've got no free new_mapping structs, and processing
2159 * this bio might require one, we pause until there are some
2160 * prepared mappings to process.
2162 if (ensure_next_mapping(pool
)) {
2163 for (j
= i
; j
< count
; j
++)
2164 list_add(&pool
->cell_sort_array
[j
]->user_list
, &cells
);
2166 spin_lock_irqsave(&tc
->lock
, flags
);
2167 list_splice(&cells
, &tc
->deferred_cells
);
2168 spin_unlock_irqrestore(&tc
->lock
, flags
);
2172 if (cell
->holder
->bi_rw
& REQ_DISCARD
)
2173 pool
->process_discard_cell(tc
, cell
);
2175 pool
->process_cell(tc
, cell
);
2177 } while (!list_empty(&cells
));
2180 static void thin_get(struct thin_c
*tc
);
2181 static void thin_put(struct thin_c
*tc
);
2184 * We can't hold rcu_read_lock() around code that can block. So we
2185 * find a thin with the rcu lock held; bump a refcount; then drop
2188 static struct thin_c
*get_first_thin(struct pool
*pool
)
2190 struct thin_c
*tc
= NULL
;
2193 if (!list_empty(&pool
->active_thins
)) {
2194 tc
= list_entry_rcu(pool
->active_thins
.next
, struct thin_c
, list
);
2202 static struct thin_c
*get_next_thin(struct pool
*pool
, struct thin_c
*tc
)
2204 struct thin_c
*old_tc
= tc
;
2207 list_for_each_entry_continue_rcu(tc
, &pool
->active_thins
, list
) {
2219 static void process_deferred_bios(struct pool
*pool
)
2221 unsigned long flags
;
2223 struct bio_list bios
;
2226 tc
= get_first_thin(pool
);
2228 process_thin_deferred_cells(tc
);
2229 process_thin_deferred_bios(tc
);
2230 tc
= get_next_thin(pool
, tc
);
2234 * If there are any deferred flush bios, we must commit
2235 * the metadata before issuing them.
2237 bio_list_init(&bios
);
2238 spin_lock_irqsave(&pool
->lock
, flags
);
2239 bio_list_merge(&bios
, &pool
->deferred_flush_bios
);
2240 bio_list_init(&pool
->deferred_flush_bios
);
2241 spin_unlock_irqrestore(&pool
->lock
, flags
);
2243 if (bio_list_empty(&bios
) &&
2244 !(dm_pool_changed_this_transaction(pool
->pmd
) && need_commit_due_to_time(pool
)))
2248 while ((bio
= bio_list_pop(&bios
)))
2252 pool
->last_commit_jiffies
= jiffies
;
2254 while ((bio
= bio_list_pop(&bios
)))
2255 generic_make_request(bio
);
2258 static void do_worker(struct work_struct
*ws
)
2260 struct pool
*pool
= container_of(ws
, struct pool
, worker
);
2262 throttle_work_start(&pool
->throttle
);
2263 dm_pool_issue_prefetches(pool
->pmd
);
2264 throttle_work_update(&pool
->throttle
);
2265 process_prepared(pool
, &pool
->prepared_mappings
, &pool
->process_prepared_mapping
);
2266 throttle_work_update(&pool
->throttle
);
2267 process_prepared(pool
, &pool
->prepared_discards
, &pool
->process_prepared_discard
);
2268 throttle_work_update(&pool
->throttle
);
2269 process_deferred_bios(pool
);
2270 throttle_work_complete(&pool
->throttle
);
2274 * We want to commit periodically so that not too much
2275 * unwritten data builds up.
2277 static void do_waker(struct work_struct
*ws
)
2279 struct pool
*pool
= container_of(to_delayed_work(ws
), struct pool
, waker
);
2281 queue_delayed_work(pool
->wq
, &pool
->waker
, COMMIT_PERIOD
);
2285 * We're holding onto IO to allow userland time to react. After the
2286 * timeout either the pool will have been resized (and thus back in
2287 * PM_WRITE mode), or we degrade to PM_READ_ONLY and start erroring IO.
2289 static void do_no_space_timeout(struct work_struct
*ws
)
2291 struct pool
*pool
= container_of(to_delayed_work(ws
), struct pool
,
2294 if (get_pool_mode(pool
) == PM_OUT_OF_DATA_SPACE
&& !pool
->pf
.error_if_no_space
)
2295 set_pool_mode(pool
, PM_READ_ONLY
);
2298 /*----------------------------------------------------------------*/
2301 struct work_struct worker
;
2302 struct completion complete
;
2305 static struct pool_work
*to_pool_work(struct work_struct
*ws
)
2307 return container_of(ws
, struct pool_work
, worker
);
2310 static void pool_work_complete(struct pool_work
*pw
)
2312 complete(&pw
->complete
);
2315 static void pool_work_wait(struct pool_work
*pw
, struct pool
*pool
,
2316 void (*fn
)(struct work_struct
*))
2318 INIT_WORK_ONSTACK(&pw
->worker
, fn
);
2319 init_completion(&pw
->complete
);
2320 queue_work(pool
->wq
, &pw
->worker
);
2321 wait_for_completion(&pw
->complete
);
2324 /*----------------------------------------------------------------*/
2326 struct noflush_work
{
2327 struct pool_work pw
;
2331 static struct noflush_work
*to_noflush(struct work_struct
*ws
)
2333 return container_of(to_pool_work(ws
), struct noflush_work
, pw
);
2336 static void do_noflush_start(struct work_struct
*ws
)
2338 struct noflush_work
*w
= to_noflush(ws
);
2339 w
->tc
->requeue_mode
= true;
2341 pool_work_complete(&w
->pw
);
2344 static void do_noflush_stop(struct work_struct
*ws
)
2346 struct noflush_work
*w
= to_noflush(ws
);
2347 w
->tc
->requeue_mode
= false;
2348 pool_work_complete(&w
->pw
);
2351 static void noflush_work(struct thin_c
*tc
, void (*fn
)(struct work_struct
*))
2353 struct noflush_work w
;
2356 pool_work_wait(&w
.pw
, tc
->pool
, fn
);
2359 /*----------------------------------------------------------------*/
2361 static enum pool_mode
get_pool_mode(struct pool
*pool
)
2363 return pool
->pf
.mode
;
2366 static void notify_of_pool_mode_change(struct pool
*pool
, const char *new_mode
)
2368 dm_table_event(pool
->ti
->table
);
2369 DMINFO("%s: switching pool to %s mode",
2370 dm_device_name(pool
->pool_md
), new_mode
);
2373 static bool passdown_enabled(struct pool_c
*pt
)
2375 return pt
->adjusted_pf
.discard_passdown
;
2378 static void set_discard_callbacks(struct pool
*pool
)
2380 struct pool_c
*pt
= pool
->ti
->private;
2382 if (passdown_enabled(pt
)) {
2383 pool
->process_discard_cell
= process_discard_cell_passdown
;
2384 pool
->process_prepared_discard
= process_prepared_discard_passdown
;
2386 pool
->process_discard_cell
= process_discard_cell_no_passdown
;
2387 pool
->process_prepared_discard
= process_prepared_discard_no_passdown
;
2391 static void set_pool_mode(struct pool
*pool
, enum pool_mode new_mode
)
2393 struct pool_c
*pt
= pool
->ti
->private;
2394 bool needs_check
= dm_pool_metadata_needs_check(pool
->pmd
);
2395 enum pool_mode old_mode
= get_pool_mode(pool
);
2396 unsigned long no_space_timeout
= ACCESS_ONCE(no_space_timeout_secs
) * HZ
;
2399 * Never allow the pool to transition to PM_WRITE mode if user
2400 * intervention is required to verify metadata and data consistency.
2402 if (new_mode
== PM_WRITE
&& needs_check
) {
2403 DMERR("%s: unable to switch pool to write mode until repaired.",
2404 dm_device_name(pool
->pool_md
));
2405 if (old_mode
!= new_mode
)
2406 new_mode
= old_mode
;
2408 new_mode
= PM_READ_ONLY
;
2411 * If we were in PM_FAIL mode, rollback of metadata failed. We're
2412 * not going to recover without a thin_repair. So we never let the
2413 * pool move out of the old mode.
2415 if (old_mode
== PM_FAIL
)
2416 new_mode
= old_mode
;
2420 if (old_mode
!= new_mode
)
2421 notify_of_pool_mode_change(pool
, "failure");
2422 dm_pool_metadata_read_only(pool
->pmd
);
2423 pool
->process_bio
= process_bio_fail
;
2424 pool
->process_discard
= process_bio_fail
;
2425 pool
->process_cell
= process_cell_fail
;
2426 pool
->process_discard_cell
= process_cell_fail
;
2427 pool
->process_prepared_mapping
= process_prepared_mapping_fail
;
2428 pool
->process_prepared_discard
= process_prepared_discard_fail
;
2430 error_retry_list(pool
);
2434 if (old_mode
!= new_mode
)
2435 notify_of_pool_mode_change(pool
, "read-only");
2436 dm_pool_metadata_read_only(pool
->pmd
);
2437 pool
->process_bio
= process_bio_read_only
;
2438 pool
->process_discard
= process_bio_success
;
2439 pool
->process_cell
= process_cell_read_only
;
2440 pool
->process_discard_cell
= process_cell_success
;
2441 pool
->process_prepared_mapping
= process_prepared_mapping_fail
;
2442 pool
->process_prepared_discard
= process_prepared_discard_success
;
2444 error_retry_list(pool
);
2447 case PM_OUT_OF_DATA_SPACE
:
2449 * Ideally we'd never hit this state; the low water mark
2450 * would trigger userland to extend the pool before we
2451 * completely run out of data space. However, many small
2452 * IOs to unprovisioned space can consume data space at an
2453 * alarming rate. Adjust your low water mark if you're
2454 * frequently seeing this mode.
2456 if (old_mode
!= new_mode
)
2457 notify_of_pool_mode_change(pool
, "out-of-data-space");
2458 pool
->process_bio
= process_bio_read_only
;
2459 pool
->process_discard
= process_discard_bio
;
2460 pool
->process_cell
= process_cell_read_only
;
2461 pool
->process_prepared_mapping
= process_prepared_mapping
;
2462 set_discard_callbacks(pool
);
2464 if (!pool
->pf
.error_if_no_space
&& no_space_timeout
)
2465 queue_delayed_work(pool
->wq
, &pool
->no_space_timeout
, no_space_timeout
);
2469 if (old_mode
!= new_mode
)
2470 notify_of_pool_mode_change(pool
, "write");
2471 dm_pool_metadata_read_write(pool
->pmd
);
2472 pool
->process_bio
= process_bio
;
2473 pool
->process_discard
= process_discard_bio
;
2474 pool
->process_cell
= process_cell
;
2475 pool
->process_prepared_mapping
= process_prepared_mapping
;
2476 set_discard_callbacks(pool
);
2480 pool
->pf
.mode
= new_mode
;
2482 * The pool mode may have changed, sync it so bind_control_target()
2483 * doesn't cause an unexpected mode transition on resume.
2485 pt
->adjusted_pf
.mode
= new_mode
;
2488 static void abort_transaction(struct pool
*pool
)
2490 const char *dev_name
= dm_device_name(pool
->pool_md
);
2492 DMERR_LIMIT("%s: aborting current metadata transaction", dev_name
);
2493 if (dm_pool_abort_metadata(pool
->pmd
)) {
2494 DMERR("%s: failed to abort metadata transaction", dev_name
);
2495 set_pool_mode(pool
, PM_FAIL
);
2498 if (dm_pool_metadata_set_needs_check(pool
->pmd
)) {
2499 DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name
);
2500 set_pool_mode(pool
, PM_FAIL
);
2504 static void metadata_operation_failed(struct pool
*pool
, const char *op
, int r
)
2506 DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d",
2507 dm_device_name(pool
->pool_md
), op
, r
);
2509 abort_transaction(pool
);
2510 set_pool_mode(pool
, PM_READ_ONLY
);
2513 /*----------------------------------------------------------------*/
2516 * Mapping functions.
2520 * Called only while mapping a thin bio to hand it over to the workqueue.
2522 static void thin_defer_bio(struct thin_c
*tc
, struct bio
*bio
)
2524 unsigned long flags
;
2525 struct pool
*pool
= tc
->pool
;
2527 spin_lock_irqsave(&tc
->lock
, flags
);
2528 bio_list_add(&tc
->deferred_bio_list
, bio
);
2529 spin_unlock_irqrestore(&tc
->lock
, flags
);
2534 static void thin_defer_bio_with_throttle(struct thin_c
*tc
, struct bio
*bio
)
2536 struct pool
*pool
= tc
->pool
;
2538 throttle_lock(&pool
->throttle
);
2539 thin_defer_bio(tc
, bio
);
2540 throttle_unlock(&pool
->throttle
);
2543 static void thin_defer_cell(struct thin_c
*tc
, struct dm_bio_prison_cell
*cell
)
2545 unsigned long flags
;
2546 struct pool
*pool
= tc
->pool
;
2548 throttle_lock(&pool
->throttle
);
2549 spin_lock_irqsave(&tc
->lock
, flags
);
2550 list_add_tail(&cell
->user_list
, &tc
->deferred_cells
);
2551 spin_unlock_irqrestore(&tc
->lock
, flags
);
2552 throttle_unlock(&pool
->throttle
);
2557 static void thin_hook_bio(struct thin_c
*tc
, struct bio
*bio
)
2559 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
2562 h
->shared_read_entry
= NULL
;
2563 h
->all_io_entry
= NULL
;
2564 h
->overwrite_mapping
= NULL
;
2569 * Non-blocking function called from the thin target's map function.
2571 static int thin_bio_map(struct dm_target
*ti
, struct bio
*bio
)
2574 struct thin_c
*tc
= ti
->private;
2575 dm_block_t block
= get_bio_block(tc
, bio
);
2576 struct dm_thin_device
*td
= tc
->td
;
2577 struct dm_thin_lookup_result result
;
2578 struct dm_bio_prison_cell
*virt_cell
, *data_cell
;
2579 struct dm_cell_key key
;
2581 thin_hook_bio(tc
, bio
);
2583 if (tc
->requeue_mode
) {
2584 bio_endio(bio
, DM_ENDIO_REQUEUE
);
2585 return DM_MAPIO_SUBMITTED
;
2588 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
2590 return DM_MAPIO_SUBMITTED
;
2593 if (bio
->bi_rw
& (REQ_DISCARD
| REQ_FLUSH
| REQ_FUA
)) {
2594 thin_defer_bio_with_throttle(tc
, bio
);
2595 return DM_MAPIO_SUBMITTED
;
2599 * We must hold the virtual cell before doing the lookup, otherwise
2600 * there's a race with discard.
2602 build_virtual_key(tc
->td
, block
, &key
);
2603 if (bio_detain(tc
->pool
, &key
, bio
, &virt_cell
))
2604 return DM_MAPIO_SUBMITTED
;
2606 r
= dm_thin_find_block(td
, block
, 0, &result
);
2609 * Note that we defer readahead too.
2613 if (unlikely(result
.shared
)) {
2615 * We have a race condition here between the
2616 * result.shared value returned by the lookup and
2617 * snapshot creation, which may cause new
2620 * To avoid this always quiesce the origin before
2621 * taking the snap. You want to do this anyway to
2622 * ensure a consistent application view
2625 * More distant ancestors are irrelevant. The
2626 * shared flag will be set in their case.
2628 thin_defer_cell(tc
, virt_cell
);
2629 return DM_MAPIO_SUBMITTED
;
2632 build_data_key(tc
->td
, result
.block
, &key
);
2633 if (bio_detain(tc
->pool
, &key
, bio
, &data_cell
)) {
2634 cell_defer_no_holder(tc
, virt_cell
);
2635 return DM_MAPIO_SUBMITTED
;
2638 inc_all_io_entry(tc
->pool
, bio
);
2639 cell_defer_no_holder(tc
, data_cell
);
2640 cell_defer_no_holder(tc
, virt_cell
);
2642 remap(tc
, bio
, result
.block
);
2643 return DM_MAPIO_REMAPPED
;
2647 thin_defer_cell(tc
, virt_cell
);
2648 return DM_MAPIO_SUBMITTED
;
2652 * Must always call bio_io_error on failure.
2653 * dm_thin_find_block can fail with -EINVAL if the
2654 * pool is switched to fail-io mode.
2657 cell_defer_no_holder(tc
, virt_cell
);
2658 return DM_MAPIO_SUBMITTED
;
2662 static int pool_is_congested(struct dm_target_callbacks
*cb
, int bdi_bits
)
2664 struct pool_c
*pt
= container_of(cb
, struct pool_c
, callbacks
);
2665 struct request_queue
*q
;
2667 if (get_pool_mode(pt
->pool
) == PM_OUT_OF_DATA_SPACE
)
2670 q
= bdev_get_queue(pt
->data_dev
->bdev
);
2671 return bdi_congested(&q
->backing_dev_info
, bdi_bits
);
2674 static void requeue_bios(struct pool
*pool
)
2676 unsigned long flags
;
2680 list_for_each_entry_rcu(tc
, &pool
->active_thins
, list
) {
2681 spin_lock_irqsave(&tc
->lock
, flags
);
2682 bio_list_merge(&tc
->deferred_bio_list
, &tc
->retry_on_resume_list
);
2683 bio_list_init(&tc
->retry_on_resume_list
);
2684 spin_unlock_irqrestore(&tc
->lock
, flags
);
2689 /*----------------------------------------------------------------
2690 * Binding of control targets to a pool object
2691 *--------------------------------------------------------------*/
2692 static bool data_dev_supports_discard(struct pool_c
*pt
)
2694 struct request_queue
*q
= bdev_get_queue(pt
->data_dev
->bdev
);
2696 return q
&& blk_queue_discard(q
);
2699 static bool is_factor(sector_t block_size
, uint32_t n
)
2701 return !sector_div(block_size
, n
);
2705 * If discard_passdown was enabled verify that the data device
2706 * supports discards. Disable discard_passdown if not.
2708 static void disable_passdown_if_not_supported(struct pool_c
*pt
)
2710 struct pool
*pool
= pt
->pool
;
2711 struct block_device
*data_bdev
= pt
->data_dev
->bdev
;
2712 struct queue_limits
*data_limits
= &bdev_get_queue(data_bdev
)->limits
;
2713 const char *reason
= NULL
;
2714 char buf
[BDEVNAME_SIZE
];
2716 if (!pt
->adjusted_pf
.discard_passdown
)
2719 if (!data_dev_supports_discard(pt
))
2720 reason
= "discard unsupported";
2722 else if (data_limits
->max_discard_sectors
< pool
->sectors_per_block
)
2723 reason
= "max discard sectors smaller than a block";
2726 DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev
, buf
), reason
);
2727 pt
->adjusted_pf
.discard_passdown
= false;
2731 static int bind_control_target(struct pool
*pool
, struct dm_target
*ti
)
2733 struct pool_c
*pt
= ti
->private;
2736 * We want to make sure that a pool in PM_FAIL mode is never upgraded.
2738 enum pool_mode old_mode
= get_pool_mode(pool
);
2739 enum pool_mode new_mode
= pt
->adjusted_pf
.mode
;
2742 * Don't change the pool's mode until set_pool_mode() below.
2743 * Otherwise the pool's process_* function pointers may
2744 * not match the desired pool mode.
2746 pt
->adjusted_pf
.mode
= old_mode
;
2749 pool
->pf
= pt
->adjusted_pf
;
2750 pool
->low_water_blocks
= pt
->low_water_blocks
;
2752 set_pool_mode(pool
, new_mode
);
2757 static void unbind_control_target(struct pool
*pool
, struct dm_target
*ti
)
2763 /*----------------------------------------------------------------
2765 *--------------------------------------------------------------*/
2766 /* Initialize pool features. */
2767 static void pool_features_init(struct pool_features
*pf
)
2769 pf
->mode
= PM_WRITE
;
2770 pf
->zero_new_blocks
= true;
2771 pf
->discard_enabled
= true;
2772 pf
->discard_passdown
= true;
2773 pf
->error_if_no_space
= false;
2776 static void __pool_destroy(struct pool
*pool
)
2778 __pool_table_remove(pool
);
2780 if (dm_pool_metadata_close(pool
->pmd
) < 0)
2781 DMWARN("%s: dm_pool_metadata_close() failed.", __func__
);
2783 dm_bio_prison_destroy(pool
->prison
);
2784 dm_kcopyd_client_destroy(pool
->copier
);
2787 destroy_workqueue(pool
->wq
);
2789 if (pool
->next_mapping
)
2790 mempool_free(pool
->next_mapping
, pool
->mapping_pool
);
2791 mempool_destroy(pool
->mapping_pool
);
2792 dm_deferred_set_destroy(pool
->shared_read_ds
);
2793 dm_deferred_set_destroy(pool
->all_io_ds
);
2797 static struct kmem_cache
*_new_mapping_cache
;
2799 static struct pool
*pool_create(struct mapped_device
*pool_md
,
2800 struct block_device
*metadata_dev
,
2801 unsigned long block_size
,
2802 int read_only
, char **error
)
2807 struct dm_pool_metadata
*pmd
;
2808 bool format_device
= read_only
? false : true;
2810 pmd
= dm_pool_metadata_open(metadata_dev
, block_size
, format_device
);
2812 *error
= "Error creating metadata object";
2813 return (struct pool
*)pmd
;
2816 pool
= kmalloc(sizeof(*pool
), GFP_KERNEL
);
2818 *error
= "Error allocating memory for pool";
2819 err_p
= ERR_PTR(-ENOMEM
);
2824 pool
->sectors_per_block
= block_size
;
2825 if (block_size
& (block_size
- 1))
2826 pool
->sectors_per_block_shift
= -1;
2828 pool
->sectors_per_block_shift
= __ffs(block_size
);
2829 pool
->low_water_blocks
= 0;
2830 pool_features_init(&pool
->pf
);
2831 pool
->prison
= dm_bio_prison_create();
2832 if (!pool
->prison
) {
2833 *error
= "Error creating pool's bio prison";
2834 err_p
= ERR_PTR(-ENOMEM
);
2838 pool
->copier
= dm_kcopyd_client_create(&dm_kcopyd_throttle
);
2839 if (IS_ERR(pool
->copier
)) {
2840 r
= PTR_ERR(pool
->copier
);
2841 *error
= "Error creating pool's kcopyd client";
2843 goto bad_kcopyd_client
;
2847 * Create singlethreaded workqueue that will service all devices
2848 * that use this metadata.
2850 pool
->wq
= alloc_ordered_workqueue("dm-" DM_MSG_PREFIX
, WQ_MEM_RECLAIM
);
2852 *error
= "Error creating pool's workqueue";
2853 err_p
= ERR_PTR(-ENOMEM
);
2857 throttle_init(&pool
->throttle
);
2858 INIT_WORK(&pool
->worker
, do_worker
);
2859 INIT_DELAYED_WORK(&pool
->waker
, do_waker
);
2860 INIT_DELAYED_WORK(&pool
->no_space_timeout
, do_no_space_timeout
);
2861 spin_lock_init(&pool
->lock
);
2862 bio_list_init(&pool
->deferred_flush_bios
);
2863 INIT_LIST_HEAD(&pool
->prepared_mappings
);
2864 INIT_LIST_HEAD(&pool
->prepared_discards
);
2865 INIT_LIST_HEAD(&pool
->active_thins
);
2866 pool
->low_water_triggered
= false;
2867 pool
->suspended
= true;
2869 pool
->shared_read_ds
= dm_deferred_set_create();
2870 if (!pool
->shared_read_ds
) {
2871 *error
= "Error creating pool's shared read deferred set";
2872 err_p
= ERR_PTR(-ENOMEM
);
2873 goto bad_shared_read_ds
;
2876 pool
->all_io_ds
= dm_deferred_set_create();
2877 if (!pool
->all_io_ds
) {
2878 *error
= "Error creating pool's all io deferred set";
2879 err_p
= ERR_PTR(-ENOMEM
);
2883 pool
->next_mapping
= NULL
;
2884 pool
->mapping_pool
= mempool_create_slab_pool(MAPPING_POOL_SIZE
,
2885 _new_mapping_cache
);
2886 if (!pool
->mapping_pool
) {
2887 *error
= "Error creating pool's mapping mempool";
2888 err_p
= ERR_PTR(-ENOMEM
);
2889 goto bad_mapping_pool
;
2892 pool
->ref_count
= 1;
2893 pool
->last_commit_jiffies
= jiffies
;
2894 pool
->pool_md
= pool_md
;
2895 pool
->md_dev
= metadata_dev
;
2896 __pool_table_insert(pool
);
2901 dm_deferred_set_destroy(pool
->all_io_ds
);
2903 dm_deferred_set_destroy(pool
->shared_read_ds
);
2905 destroy_workqueue(pool
->wq
);
2907 dm_kcopyd_client_destroy(pool
->copier
);
2909 dm_bio_prison_destroy(pool
->prison
);
2913 if (dm_pool_metadata_close(pmd
))
2914 DMWARN("%s: dm_pool_metadata_close() failed.", __func__
);
2919 static void __pool_inc(struct pool
*pool
)
2921 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
2925 static void __pool_dec(struct pool
*pool
)
2927 BUG_ON(!mutex_is_locked(&dm_thin_pool_table
.mutex
));
2928 BUG_ON(!pool
->ref_count
);
2929 if (!--pool
->ref_count
)
2930 __pool_destroy(pool
);
2933 static struct pool
*__pool_find(struct mapped_device
*pool_md
,
2934 struct block_device
*metadata_dev
,
2935 unsigned long block_size
, int read_only
,
2936 char **error
, int *created
)
2938 struct pool
*pool
= __pool_table_lookup_metadata_dev(metadata_dev
);
2941 if (pool
->pool_md
!= pool_md
) {
2942 *error
= "metadata device already in use by a pool";
2943 return ERR_PTR(-EBUSY
);
2948 pool
= __pool_table_lookup(pool_md
);
2950 if (pool
->md_dev
!= metadata_dev
) {
2951 *error
= "different pool cannot replace a pool";
2952 return ERR_PTR(-EINVAL
);
2957 pool
= pool_create(pool_md
, metadata_dev
, block_size
, read_only
, error
);
2965 /*----------------------------------------------------------------
2966 * Pool target methods
2967 *--------------------------------------------------------------*/
2968 static void pool_dtr(struct dm_target
*ti
)
2970 struct pool_c
*pt
= ti
->private;
2972 mutex_lock(&dm_thin_pool_table
.mutex
);
2974 unbind_control_target(pt
->pool
, ti
);
2975 __pool_dec(pt
->pool
);
2976 dm_put_device(ti
, pt
->metadata_dev
);
2977 dm_put_device(ti
, pt
->data_dev
);
2980 mutex_unlock(&dm_thin_pool_table
.mutex
);
2983 static int parse_pool_features(struct dm_arg_set
*as
, struct pool_features
*pf
,
2984 struct dm_target
*ti
)
2988 const char *arg_name
;
2990 static struct dm_arg _args
[] = {
2991 {0, 4, "Invalid number of pool feature arguments"},
2995 * No feature arguments supplied.
3000 r
= dm_read_arg_group(_args
, as
, &argc
, &ti
->error
);
3004 while (argc
&& !r
) {
3005 arg_name
= dm_shift_arg(as
);
3008 if (!strcasecmp(arg_name
, "skip_block_zeroing"))
3009 pf
->zero_new_blocks
= false;
3011 else if (!strcasecmp(arg_name
, "ignore_discard"))
3012 pf
->discard_enabled
= false;
3014 else if (!strcasecmp(arg_name
, "no_discard_passdown"))
3015 pf
->discard_passdown
= false;
3017 else if (!strcasecmp(arg_name
, "read_only"))
3018 pf
->mode
= PM_READ_ONLY
;
3020 else if (!strcasecmp(arg_name
, "error_if_no_space"))
3021 pf
->error_if_no_space
= true;
3024 ti
->error
= "Unrecognised pool feature requested";
3033 static void metadata_low_callback(void *context
)
3035 struct pool
*pool
= context
;
3037 DMWARN("%s: reached low water mark for metadata device: sending event.",
3038 dm_device_name(pool
->pool_md
));
3040 dm_table_event(pool
->ti
->table
);
3043 static sector_t
get_dev_size(struct block_device
*bdev
)
3045 return i_size_read(bdev
->bd_inode
) >> SECTOR_SHIFT
;
3048 static void warn_if_metadata_device_too_big(struct block_device
*bdev
)
3050 sector_t metadata_dev_size
= get_dev_size(bdev
);
3051 char buffer
[BDEVNAME_SIZE
];
3053 if (metadata_dev_size
> THIN_METADATA_MAX_SECTORS_WARNING
)
3054 DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",
3055 bdevname(bdev
, buffer
), THIN_METADATA_MAX_SECTORS
);
3058 static sector_t
get_metadata_dev_size(struct block_device
*bdev
)
3060 sector_t metadata_dev_size
= get_dev_size(bdev
);
3062 if (metadata_dev_size
> THIN_METADATA_MAX_SECTORS
)
3063 metadata_dev_size
= THIN_METADATA_MAX_SECTORS
;
3065 return metadata_dev_size
;
3068 static dm_block_t
get_metadata_dev_size_in_blocks(struct block_device
*bdev
)
3070 sector_t metadata_dev_size
= get_metadata_dev_size(bdev
);
3072 sector_div(metadata_dev_size
, THIN_METADATA_BLOCK_SIZE
);
3074 return metadata_dev_size
;
3078 * When a metadata threshold is crossed a dm event is triggered, and
3079 * userland should respond by growing the metadata device. We could let
3080 * userland set the threshold, like we do with the data threshold, but I'm
3081 * not sure they know enough to do this well.
3083 static dm_block_t
calc_metadata_threshold(struct pool_c
*pt
)
3086 * 4M is ample for all ops with the possible exception of thin
3087 * device deletion which is harmless if it fails (just retry the
3088 * delete after you've grown the device).
3090 dm_block_t quarter
= get_metadata_dev_size_in_blocks(pt
->metadata_dev
->bdev
) / 4;
3091 return min((dm_block_t
)1024ULL /* 4M */, quarter
);
3095 * thin-pool <metadata dev> <data dev>
3096 * <data block size (sectors)>
3097 * <low water mark (blocks)>
3098 * [<#feature args> [<arg>]*]
3100 * Optional feature arguments are:
3101 * skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
3102 * ignore_discard: disable discard
3103 * no_discard_passdown: don't pass discards down to the data device
3104 * read_only: Don't allow any changes to be made to the pool metadata.
3105 * error_if_no_space: error IOs, instead of queueing, if no space.
3107 static int pool_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
3109 int r
, pool_created
= 0;
3112 struct pool_features pf
;
3113 struct dm_arg_set as
;
3114 struct dm_dev
*data_dev
;
3115 unsigned long block_size
;
3116 dm_block_t low_water_blocks
;
3117 struct dm_dev
*metadata_dev
;
3118 fmode_t metadata_mode
;
3121 * FIXME Remove validation from scope of lock.
3123 mutex_lock(&dm_thin_pool_table
.mutex
);
3126 ti
->error
= "Invalid argument count";
3135 * Set default pool features.
3137 pool_features_init(&pf
);
3139 dm_consume_args(&as
, 4);
3140 r
= parse_pool_features(&as
, &pf
, ti
);
3144 metadata_mode
= FMODE_READ
| ((pf
.mode
== PM_READ_ONLY
) ? 0 : FMODE_WRITE
);
3145 r
= dm_get_device(ti
, argv
[0], metadata_mode
, &metadata_dev
);
3147 ti
->error
= "Error opening metadata block device";
3150 warn_if_metadata_device_too_big(metadata_dev
->bdev
);
3152 r
= dm_get_device(ti
, argv
[1], FMODE_READ
| FMODE_WRITE
, &data_dev
);
3154 ti
->error
= "Error getting data device";
3158 if (kstrtoul(argv
[2], 10, &block_size
) || !block_size
||
3159 block_size
< DATA_DEV_BLOCK_SIZE_MIN_SECTORS
||
3160 block_size
> DATA_DEV_BLOCK_SIZE_MAX_SECTORS
||
3161 block_size
& (DATA_DEV_BLOCK_SIZE_MIN_SECTORS
- 1)) {
3162 ti
->error
= "Invalid block size";
3167 if (kstrtoull(argv
[3], 10, (unsigned long long *)&low_water_blocks
)) {
3168 ti
->error
= "Invalid low water mark";
3173 pt
= kzalloc(sizeof(*pt
), GFP_KERNEL
);
3179 pool
= __pool_find(dm_table_get_md(ti
->table
), metadata_dev
->bdev
,
3180 block_size
, pf
.mode
== PM_READ_ONLY
, &ti
->error
, &pool_created
);
3187 * 'pool_created' reflects whether this is the first table load.
3188 * Top level discard support is not allowed to be changed after
3189 * initial load. This would require a pool reload to trigger thin
3192 if (!pool_created
&& pf
.discard_enabled
!= pool
->pf
.discard_enabled
) {
3193 ti
->error
= "Discard support cannot be disabled once enabled";
3195 goto out_flags_changed
;
3200 pt
->metadata_dev
= metadata_dev
;
3201 pt
->data_dev
= data_dev
;
3202 pt
->low_water_blocks
= low_water_blocks
;
3203 pt
->adjusted_pf
= pt
->requested_pf
= pf
;
3204 ti
->num_flush_bios
= 1;
3207 * Only need to enable discards if the pool should pass
3208 * them down to the data device. The thin device's discard
3209 * processing will cause mappings to be removed from the btree.
3211 ti
->discard_zeroes_data_unsupported
= true;
3212 if (pf
.discard_enabled
&& pf
.discard_passdown
) {
3213 ti
->num_discard_bios
= 1;
3216 * Setting 'discards_supported' circumvents the normal
3217 * stacking of discard limits (this keeps the pool and
3218 * thin devices' discard limits consistent).
3220 ti
->discards_supported
= true;
3224 r
= dm_pool_register_metadata_threshold(pt
->pool
->pmd
,
3225 calc_metadata_threshold(pt
),
3226 metadata_low_callback
,
3231 pt
->callbacks
.congested_fn
= pool_is_congested
;
3232 dm_table_add_target_callbacks(ti
->table
, &pt
->callbacks
);
3234 mutex_unlock(&dm_thin_pool_table
.mutex
);
3243 dm_put_device(ti
, data_dev
);
3245 dm_put_device(ti
, metadata_dev
);
3247 mutex_unlock(&dm_thin_pool_table
.mutex
);
3252 static int pool_map(struct dm_target
*ti
, struct bio
*bio
)
3255 struct pool_c
*pt
= ti
->private;
3256 struct pool
*pool
= pt
->pool
;
3257 unsigned long flags
;
3260 * As this is a singleton target, ti->begin is always zero.
3262 spin_lock_irqsave(&pool
->lock
, flags
);
3263 bio
->bi_bdev
= pt
->data_dev
->bdev
;
3264 r
= DM_MAPIO_REMAPPED
;
3265 spin_unlock_irqrestore(&pool
->lock
, flags
);
3270 static int maybe_resize_data_dev(struct dm_target
*ti
, bool *need_commit
)
3273 struct pool_c
*pt
= ti
->private;
3274 struct pool
*pool
= pt
->pool
;
3275 sector_t data_size
= ti
->len
;
3276 dm_block_t sb_data_size
;
3278 *need_commit
= false;
3280 (void) sector_div(data_size
, pool
->sectors_per_block
);
3282 r
= dm_pool_get_data_dev_size(pool
->pmd
, &sb_data_size
);
3284 DMERR("%s: failed to retrieve data device size",
3285 dm_device_name(pool
->pool_md
));
3289 if (data_size
< sb_data_size
) {
3290 DMERR("%s: pool target (%llu blocks) too small: expected %llu",
3291 dm_device_name(pool
->pool_md
),
3292 (unsigned long long)data_size
, sb_data_size
);
3295 } else if (data_size
> sb_data_size
) {
3296 if (dm_pool_metadata_needs_check(pool
->pmd
)) {
3297 DMERR("%s: unable to grow the data device until repaired.",
3298 dm_device_name(pool
->pool_md
));
3303 DMINFO("%s: growing the data device from %llu to %llu blocks",
3304 dm_device_name(pool
->pool_md
),
3305 sb_data_size
, (unsigned long long)data_size
);
3306 r
= dm_pool_resize_data_dev(pool
->pmd
, data_size
);
3308 metadata_operation_failed(pool
, "dm_pool_resize_data_dev", r
);
3312 *need_commit
= true;
3318 static int maybe_resize_metadata_dev(struct dm_target
*ti
, bool *need_commit
)
3321 struct pool_c
*pt
= ti
->private;
3322 struct pool
*pool
= pt
->pool
;
3323 dm_block_t metadata_dev_size
, sb_metadata_dev_size
;
3325 *need_commit
= false;
3327 metadata_dev_size
= get_metadata_dev_size_in_blocks(pool
->md_dev
);
3329 r
= dm_pool_get_metadata_dev_size(pool
->pmd
, &sb_metadata_dev_size
);
3331 DMERR("%s: failed to retrieve metadata device size",
3332 dm_device_name(pool
->pool_md
));
3336 if (metadata_dev_size
< sb_metadata_dev_size
) {
3337 DMERR("%s: metadata device (%llu blocks) too small: expected %llu",
3338 dm_device_name(pool
->pool_md
),
3339 metadata_dev_size
, sb_metadata_dev_size
);
3342 } else if (metadata_dev_size
> sb_metadata_dev_size
) {
3343 if (dm_pool_metadata_needs_check(pool
->pmd
)) {
3344 DMERR("%s: unable to grow the metadata device until repaired.",
3345 dm_device_name(pool
->pool_md
));
3349 warn_if_metadata_device_too_big(pool
->md_dev
);
3350 DMINFO("%s: growing the metadata device from %llu to %llu blocks",
3351 dm_device_name(pool
->pool_md
),
3352 sb_metadata_dev_size
, metadata_dev_size
);
3353 r
= dm_pool_resize_metadata_dev(pool
->pmd
, metadata_dev_size
);
3355 metadata_operation_failed(pool
, "dm_pool_resize_metadata_dev", r
);
3359 *need_commit
= true;
3366 * Retrieves the number of blocks of the data device from
3367 * the superblock and compares it to the actual device size,
3368 * thus resizing the data device in case it has grown.
3370 * This both copes with opening preallocated data devices in the ctr
3371 * being followed by a resume
3373 * calling the resume method individually after userspace has
3374 * grown the data device in reaction to a table event.
3376 static int pool_preresume(struct dm_target
*ti
)
3379 bool need_commit1
, need_commit2
;
3380 struct pool_c
*pt
= ti
->private;
3381 struct pool
*pool
= pt
->pool
;
3384 * Take control of the pool object.
3386 r
= bind_control_target(pool
, ti
);
3390 r
= maybe_resize_data_dev(ti
, &need_commit1
);
3394 r
= maybe_resize_metadata_dev(ti
, &need_commit2
);
3398 if (need_commit1
|| need_commit2
)
3399 (void) commit(pool
);
3404 static void pool_suspend_active_thins(struct pool
*pool
)
3408 /* Suspend all active thin devices */
3409 tc
= get_first_thin(pool
);
3411 dm_internal_suspend_noflush(tc
->thin_md
);
3412 tc
= get_next_thin(pool
, tc
);
3416 static void pool_resume_active_thins(struct pool
*pool
)
3420 /* Resume all active thin devices */
3421 tc
= get_first_thin(pool
);
3423 dm_internal_resume(tc
->thin_md
);
3424 tc
= get_next_thin(pool
, tc
);
3428 static void pool_resume(struct dm_target
*ti
)
3430 struct pool_c
*pt
= ti
->private;
3431 struct pool
*pool
= pt
->pool
;
3432 unsigned long flags
;
3435 * Must requeue active_thins' bios and then resume
3436 * active_thins _before_ clearing 'suspend' flag.
3439 pool_resume_active_thins(pool
);
3441 spin_lock_irqsave(&pool
->lock
, flags
);
3442 pool
->low_water_triggered
= false;
3443 pool
->suspended
= false;
3444 spin_unlock_irqrestore(&pool
->lock
, flags
);
3446 do_waker(&pool
->waker
.work
);
3449 static void pool_presuspend(struct dm_target
*ti
)
3451 struct pool_c
*pt
= ti
->private;
3452 struct pool
*pool
= pt
->pool
;
3453 unsigned long flags
;
3455 spin_lock_irqsave(&pool
->lock
, flags
);
3456 pool
->suspended
= true;
3457 spin_unlock_irqrestore(&pool
->lock
, flags
);
3459 pool_suspend_active_thins(pool
);
3462 static void pool_presuspend_undo(struct dm_target
*ti
)
3464 struct pool_c
*pt
= ti
->private;
3465 struct pool
*pool
= pt
->pool
;
3466 unsigned long flags
;
3468 pool_resume_active_thins(pool
);
3470 spin_lock_irqsave(&pool
->lock
, flags
);
3471 pool
->suspended
= false;
3472 spin_unlock_irqrestore(&pool
->lock
, flags
);
3475 static void pool_postsuspend(struct dm_target
*ti
)
3477 struct pool_c
*pt
= ti
->private;
3478 struct pool
*pool
= pt
->pool
;
3480 cancel_delayed_work(&pool
->waker
);
3481 cancel_delayed_work(&pool
->no_space_timeout
);
3482 flush_workqueue(pool
->wq
);
3483 (void) commit(pool
);
3486 static int check_arg_count(unsigned argc
, unsigned args_required
)
3488 if (argc
!= args_required
) {
3489 DMWARN("Message received with %u arguments instead of %u.",
3490 argc
, args_required
);
3497 static int read_dev_id(char *arg
, dm_thin_id
*dev_id
, int warning
)
3499 if (!kstrtoull(arg
, 10, (unsigned long long *)dev_id
) &&
3500 *dev_id
<= MAX_DEV_ID
)
3504 DMWARN("Message received with invalid device id: %s", arg
);
3509 static int process_create_thin_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3514 r
= check_arg_count(argc
, 2);
3518 r
= read_dev_id(argv
[1], &dev_id
, 1);
3522 r
= dm_pool_create_thin(pool
->pmd
, dev_id
);
3524 DMWARN("Creation of new thinly-provisioned device with id %s failed.",
3532 static int process_create_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3535 dm_thin_id origin_dev_id
;
3538 r
= check_arg_count(argc
, 3);
3542 r
= read_dev_id(argv
[1], &dev_id
, 1);
3546 r
= read_dev_id(argv
[2], &origin_dev_id
, 1);
3550 r
= dm_pool_create_snap(pool
->pmd
, dev_id
, origin_dev_id
);
3552 DMWARN("Creation of new snapshot %s of device %s failed.",
3560 static int process_delete_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3565 r
= check_arg_count(argc
, 2);
3569 r
= read_dev_id(argv
[1], &dev_id
, 1);
3573 r
= dm_pool_delete_thin_device(pool
->pmd
, dev_id
);
3575 DMWARN("Deletion of thin device %s failed.", argv
[1]);
3580 static int process_set_transaction_id_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3582 dm_thin_id old_id
, new_id
;
3585 r
= check_arg_count(argc
, 3);
3589 if (kstrtoull(argv
[1], 10, (unsigned long long *)&old_id
)) {
3590 DMWARN("set_transaction_id message: Unrecognised id %s.", argv
[1]);
3594 if (kstrtoull(argv
[2], 10, (unsigned long long *)&new_id
)) {
3595 DMWARN("set_transaction_id message: Unrecognised new id %s.", argv
[2]);
3599 r
= dm_pool_set_metadata_transaction_id(pool
->pmd
, old_id
, new_id
);
3601 DMWARN("Failed to change transaction id from %s to %s.",
3609 static int process_reserve_metadata_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3613 r
= check_arg_count(argc
, 1);
3617 (void) commit(pool
);
3619 r
= dm_pool_reserve_metadata_snap(pool
->pmd
);
3621 DMWARN("reserve_metadata_snap message failed.");
3626 static int process_release_metadata_snap_mesg(unsigned argc
, char **argv
, struct pool
*pool
)
3630 r
= check_arg_count(argc
, 1);
3634 r
= dm_pool_release_metadata_snap(pool
->pmd
);
3636 DMWARN("release_metadata_snap message failed.");
3642 * Messages supported:
3643 * create_thin <dev_id>
3644 * create_snap <dev_id> <origin_id>
3646 * set_transaction_id <current_trans_id> <new_trans_id>
3647 * reserve_metadata_snap
3648 * release_metadata_snap
3650 static int pool_message(struct dm_target
*ti
, unsigned argc
, char **argv
)
3653 struct pool_c
*pt
= ti
->private;
3654 struct pool
*pool
= pt
->pool
;
3656 if (get_pool_mode(pool
) >= PM_READ_ONLY
) {
3657 DMERR("%s: unable to service pool target messages in READ_ONLY or FAIL mode",
3658 dm_device_name(pool
->pool_md
));
3662 if (!strcasecmp(argv
[0], "create_thin"))
3663 r
= process_create_thin_mesg(argc
, argv
, pool
);
3665 else if (!strcasecmp(argv
[0], "create_snap"))
3666 r
= process_create_snap_mesg(argc
, argv
, pool
);
3668 else if (!strcasecmp(argv
[0], "delete"))
3669 r
= process_delete_mesg(argc
, argv
, pool
);
3671 else if (!strcasecmp(argv
[0], "set_transaction_id"))
3672 r
= process_set_transaction_id_mesg(argc
, argv
, pool
);
3674 else if (!strcasecmp(argv
[0], "reserve_metadata_snap"))
3675 r
= process_reserve_metadata_snap_mesg(argc
, argv
, pool
);
3677 else if (!strcasecmp(argv
[0], "release_metadata_snap"))
3678 r
= process_release_metadata_snap_mesg(argc
, argv
, pool
);
3681 DMWARN("Unrecognised thin pool target message received: %s", argv
[0]);
3684 (void) commit(pool
);
3689 static void emit_flags(struct pool_features
*pf
, char *result
,
3690 unsigned sz
, unsigned maxlen
)
3692 unsigned count
= !pf
->zero_new_blocks
+ !pf
->discard_enabled
+
3693 !pf
->discard_passdown
+ (pf
->mode
== PM_READ_ONLY
) +
3694 pf
->error_if_no_space
;
3695 DMEMIT("%u ", count
);
3697 if (!pf
->zero_new_blocks
)
3698 DMEMIT("skip_block_zeroing ");
3700 if (!pf
->discard_enabled
)
3701 DMEMIT("ignore_discard ");
3703 if (!pf
->discard_passdown
)
3704 DMEMIT("no_discard_passdown ");
3706 if (pf
->mode
== PM_READ_ONLY
)
3707 DMEMIT("read_only ");
3709 if (pf
->error_if_no_space
)
3710 DMEMIT("error_if_no_space ");
3715 * <transaction id> <used metadata sectors>/<total metadata sectors>
3716 * <used data sectors>/<total data sectors> <held metadata root>
3718 static void pool_status(struct dm_target
*ti
, status_type_t type
,
3719 unsigned status_flags
, char *result
, unsigned maxlen
)
3723 uint64_t transaction_id
;
3724 dm_block_t nr_free_blocks_data
;
3725 dm_block_t nr_free_blocks_metadata
;
3726 dm_block_t nr_blocks_data
;
3727 dm_block_t nr_blocks_metadata
;
3728 dm_block_t held_root
;
3729 char buf
[BDEVNAME_SIZE
];
3730 char buf2
[BDEVNAME_SIZE
];
3731 struct pool_c
*pt
= ti
->private;
3732 struct pool
*pool
= pt
->pool
;
3735 case STATUSTYPE_INFO
:
3736 if (get_pool_mode(pool
) == PM_FAIL
) {
3741 /* Commit to ensure statistics aren't out-of-date */
3742 if (!(status_flags
& DM_STATUS_NOFLUSH_FLAG
) && !dm_suspended(ti
))
3743 (void) commit(pool
);
3745 r
= dm_pool_get_metadata_transaction_id(pool
->pmd
, &transaction_id
);
3747 DMERR("%s: dm_pool_get_metadata_transaction_id returned %d",
3748 dm_device_name(pool
->pool_md
), r
);
3752 r
= dm_pool_get_free_metadata_block_count(pool
->pmd
, &nr_free_blocks_metadata
);
3754 DMERR("%s: dm_pool_get_free_metadata_block_count returned %d",
3755 dm_device_name(pool
->pool_md
), r
);
3759 r
= dm_pool_get_metadata_dev_size(pool
->pmd
, &nr_blocks_metadata
);
3761 DMERR("%s: dm_pool_get_metadata_dev_size returned %d",
3762 dm_device_name(pool
->pool_md
), r
);
3766 r
= dm_pool_get_free_block_count(pool
->pmd
, &nr_free_blocks_data
);
3768 DMERR("%s: dm_pool_get_free_block_count returned %d",
3769 dm_device_name(pool
->pool_md
), r
);
3773 r
= dm_pool_get_data_dev_size(pool
->pmd
, &nr_blocks_data
);
3775 DMERR("%s: dm_pool_get_data_dev_size returned %d",
3776 dm_device_name(pool
->pool_md
), r
);
3780 r
= dm_pool_get_metadata_snap(pool
->pmd
, &held_root
);
3782 DMERR("%s: dm_pool_get_metadata_snap returned %d",
3783 dm_device_name(pool
->pool_md
), r
);
3787 DMEMIT("%llu %llu/%llu %llu/%llu ",
3788 (unsigned long long)transaction_id
,
3789 (unsigned long long)(nr_blocks_metadata
- nr_free_blocks_metadata
),
3790 (unsigned long long)nr_blocks_metadata
,
3791 (unsigned long long)(nr_blocks_data
- nr_free_blocks_data
),
3792 (unsigned long long)nr_blocks_data
);
3795 DMEMIT("%llu ", held_root
);
3799 if (pool
->pf
.mode
== PM_OUT_OF_DATA_SPACE
)
3800 DMEMIT("out_of_data_space ");
3801 else if (pool
->pf
.mode
== PM_READ_ONLY
)
3806 if (!pool
->pf
.discard_enabled
)
3807 DMEMIT("ignore_discard ");
3808 else if (pool
->pf
.discard_passdown
)
3809 DMEMIT("discard_passdown ");
3811 DMEMIT("no_discard_passdown ");
3813 if (pool
->pf
.error_if_no_space
)
3814 DMEMIT("error_if_no_space ");
3816 DMEMIT("queue_if_no_space ");
3820 case STATUSTYPE_TABLE
:
3821 DMEMIT("%s %s %lu %llu ",
3822 format_dev_t(buf
, pt
->metadata_dev
->bdev
->bd_dev
),
3823 format_dev_t(buf2
, pt
->data_dev
->bdev
->bd_dev
),
3824 (unsigned long)pool
->sectors_per_block
,
3825 (unsigned long long)pt
->low_water_blocks
);
3826 emit_flags(&pt
->requested_pf
, result
, sz
, maxlen
);
3835 static int pool_iterate_devices(struct dm_target
*ti
,
3836 iterate_devices_callout_fn fn
, void *data
)
3838 struct pool_c
*pt
= ti
->private;
3840 return fn(ti
, pt
->data_dev
, 0, ti
->len
, data
);
3843 static int pool_merge(struct dm_target
*ti
, struct bvec_merge_data
*bvm
,
3844 struct bio_vec
*biovec
, int max_size
)
3846 struct pool_c
*pt
= ti
->private;
3847 struct request_queue
*q
= bdev_get_queue(pt
->data_dev
->bdev
);
3849 if (!q
->merge_bvec_fn
)
3852 bvm
->bi_bdev
= pt
->data_dev
->bdev
;
3854 return min(max_size
, q
->merge_bvec_fn(q
, bvm
, biovec
));
3857 static void pool_io_hints(struct dm_target
*ti
, struct queue_limits
*limits
)
3859 struct pool_c
*pt
= ti
->private;
3860 struct pool
*pool
= pt
->pool
;
3861 sector_t io_opt_sectors
= limits
->io_opt
>> SECTOR_SHIFT
;
3864 * If max_sectors is smaller than pool->sectors_per_block adjust it
3865 * to the highest possible power-of-2 factor of pool->sectors_per_block.
3866 * This is especially beneficial when the pool's data device is a RAID
3867 * device that has a full stripe width that matches pool->sectors_per_block
3868 * -- because even though partial RAID stripe-sized IOs will be issued to a
3869 * single RAID stripe; when aggregated they will end on a full RAID stripe
3870 * boundary.. which avoids additional partial RAID stripe writes cascading
3872 if (limits
->max_sectors
< pool
->sectors_per_block
) {
3873 while (!is_factor(pool
->sectors_per_block
, limits
->max_sectors
)) {
3874 if ((limits
->max_sectors
& (limits
->max_sectors
- 1)) == 0)
3875 limits
->max_sectors
--;
3876 limits
->max_sectors
= rounddown_pow_of_two(limits
->max_sectors
);
3881 * If the system-determined stacked limits are compatible with the
3882 * pool's blocksize (io_opt is a factor) do not override them.
3884 if (io_opt_sectors
< pool
->sectors_per_block
||
3885 !is_factor(io_opt_sectors
, pool
->sectors_per_block
)) {
3886 if (is_factor(pool
->sectors_per_block
, limits
->max_sectors
))
3887 blk_limits_io_min(limits
, limits
->max_sectors
<< SECTOR_SHIFT
);
3889 blk_limits_io_min(limits
, pool
->sectors_per_block
<< SECTOR_SHIFT
);
3890 blk_limits_io_opt(limits
, pool
->sectors_per_block
<< SECTOR_SHIFT
);
3894 * pt->adjusted_pf is a staging area for the actual features to use.
3895 * They get transferred to the live pool in bind_control_target()
3896 * called from pool_preresume().
3898 if (!pt
->adjusted_pf
.discard_enabled
) {
3900 * Must explicitly disallow stacking discard limits otherwise the
3901 * block layer will stack them if pool's data device has support.
3902 * QUEUE_FLAG_DISCARD wouldn't be set but there is no way for the
3903 * user to see that, so make sure to set all discard limits to 0.
3905 limits
->discard_granularity
= 0;
3909 disable_passdown_if_not_supported(pt
);
3912 * The pool uses the same discard limits as the underlying data
3913 * device. DM core has already set this up.
3917 static struct target_type pool_target
= {
3918 .name
= "thin-pool",
3919 .features
= DM_TARGET_SINGLETON
| DM_TARGET_ALWAYS_WRITEABLE
|
3920 DM_TARGET_IMMUTABLE
,
3921 .version
= {1, 15, 0},
3922 .module
= THIS_MODULE
,
3926 .presuspend
= pool_presuspend
,
3927 .presuspend_undo
= pool_presuspend_undo
,
3928 .postsuspend
= pool_postsuspend
,
3929 .preresume
= pool_preresume
,
3930 .resume
= pool_resume
,
3931 .message
= pool_message
,
3932 .status
= pool_status
,
3933 .merge
= pool_merge
,
3934 .iterate_devices
= pool_iterate_devices
,
3935 .io_hints
= pool_io_hints
,
3938 /*----------------------------------------------------------------
3939 * Thin target methods
3940 *--------------------------------------------------------------*/
3941 static void thin_get(struct thin_c
*tc
)
3943 atomic_inc(&tc
->refcount
);
3946 static void thin_put(struct thin_c
*tc
)
3948 if (atomic_dec_and_test(&tc
->refcount
))
3949 complete(&tc
->can_destroy
);
3952 static void thin_dtr(struct dm_target
*ti
)
3954 struct thin_c
*tc
= ti
->private;
3955 unsigned long flags
;
3957 spin_lock_irqsave(&tc
->pool
->lock
, flags
);
3958 list_del_rcu(&tc
->list
);
3959 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
3963 wait_for_completion(&tc
->can_destroy
);
3965 mutex_lock(&dm_thin_pool_table
.mutex
);
3967 __pool_dec(tc
->pool
);
3968 dm_pool_close_thin_device(tc
->td
);
3969 dm_put_device(ti
, tc
->pool_dev
);
3971 dm_put_device(ti
, tc
->origin_dev
);
3974 mutex_unlock(&dm_thin_pool_table
.mutex
);
3978 * Thin target parameters:
3980 * <pool_dev> <dev_id> [origin_dev]
3982 * pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
3983 * dev_id: the internal device identifier
3984 * origin_dev: a device external to the pool that should act as the origin
3986 * If the pool device has discards disabled, they get disabled for the thin
3989 static int thin_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
3993 struct dm_dev
*pool_dev
, *origin_dev
;
3994 struct mapped_device
*pool_md
;
3995 unsigned long flags
;
3997 mutex_lock(&dm_thin_pool_table
.mutex
);
3999 if (argc
!= 2 && argc
!= 3) {
4000 ti
->error
= "Invalid argument count";
4005 tc
= ti
->private = kzalloc(sizeof(*tc
), GFP_KERNEL
);
4007 ti
->error
= "Out of memory";
4011 tc
->thin_md
= dm_table_get_md(ti
->table
);
4012 spin_lock_init(&tc
->lock
);
4013 INIT_LIST_HEAD(&tc
->deferred_cells
);
4014 bio_list_init(&tc
->deferred_bio_list
);
4015 bio_list_init(&tc
->retry_on_resume_list
);
4016 tc
->sort_bio_list
= RB_ROOT
;
4019 r
= dm_get_device(ti
, argv
[2], FMODE_READ
, &origin_dev
);
4021 ti
->error
= "Error opening origin device";
4022 goto bad_origin_dev
;
4024 tc
->origin_dev
= origin_dev
;
4027 r
= dm_get_device(ti
, argv
[0], dm_table_get_mode(ti
->table
), &pool_dev
);
4029 ti
->error
= "Error opening pool device";
4032 tc
->pool_dev
= pool_dev
;
4034 if (read_dev_id(argv
[1], (unsigned long long *)&tc
->dev_id
, 0)) {
4035 ti
->error
= "Invalid device id";
4040 pool_md
= dm_get_md(tc
->pool_dev
->bdev
->bd_dev
);
4042 ti
->error
= "Couldn't get pool mapped device";
4047 tc
->pool
= __pool_table_lookup(pool_md
);
4049 ti
->error
= "Couldn't find pool object";
4051 goto bad_pool_lookup
;
4053 __pool_inc(tc
->pool
);
4055 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
4056 ti
->error
= "Couldn't open thin device, Pool is in fail mode";
4061 r
= dm_pool_open_thin_device(tc
->pool
->pmd
, tc
->dev_id
, &tc
->td
);
4063 ti
->error
= "Couldn't open thin internal device";
4067 r
= dm_set_target_max_io_len(ti
, tc
->pool
->sectors_per_block
);
4071 ti
->num_flush_bios
= 1;
4072 ti
->flush_supported
= true;
4073 ti
->per_bio_data_size
= sizeof(struct dm_thin_endio_hook
);
4075 /* In case the pool supports discards, pass them on. */
4076 ti
->discard_zeroes_data_unsupported
= true;
4077 if (tc
->pool
->pf
.discard_enabled
) {
4078 ti
->discards_supported
= true;
4079 ti
->num_discard_bios
= 1;
4080 ti
->split_discard_bios
= false;
4083 mutex_unlock(&dm_thin_pool_table
.mutex
);
4085 spin_lock_irqsave(&tc
->pool
->lock
, flags
);
4086 if (tc
->pool
->suspended
) {
4087 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
4088 mutex_lock(&dm_thin_pool_table
.mutex
); /* reacquire for __pool_dec */
4089 ti
->error
= "Unable to activate thin device while pool is suspended";
4093 atomic_set(&tc
->refcount
, 1);
4094 init_completion(&tc
->can_destroy
);
4095 list_add_tail_rcu(&tc
->list
, &tc
->pool
->active_thins
);
4096 spin_unlock_irqrestore(&tc
->pool
->lock
, flags
);
4098 * This synchronize_rcu() call is needed here otherwise we risk a
4099 * wake_worker() call finding no bios to process (because the newly
4100 * added tc isn't yet visible). So this reduces latency since we
4101 * aren't then dependent on the periodic commit to wake_worker().
4110 dm_pool_close_thin_device(tc
->td
);
4112 __pool_dec(tc
->pool
);
4116 dm_put_device(ti
, tc
->pool_dev
);
4119 dm_put_device(ti
, tc
->origin_dev
);
4123 mutex_unlock(&dm_thin_pool_table
.mutex
);
4128 static int thin_map(struct dm_target
*ti
, struct bio
*bio
)
4130 bio
->bi_iter
.bi_sector
= dm_target_offset(ti
, bio
->bi_iter
.bi_sector
);
4132 return thin_bio_map(ti
, bio
);
4135 static int thin_endio(struct dm_target
*ti
, struct bio
*bio
, int err
)
4137 unsigned long flags
;
4138 struct dm_thin_endio_hook
*h
= dm_per_bio_data(bio
, sizeof(struct dm_thin_endio_hook
));
4139 struct list_head work
;
4140 struct dm_thin_new_mapping
*m
, *tmp
;
4141 struct pool
*pool
= h
->tc
->pool
;
4143 if (h
->shared_read_entry
) {
4144 INIT_LIST_HEAD(&work
);
4145 dm_deferred_entry_dec(h
->shared_read_entry
, &work
);
4147 spin_lock_irqsave(&pool
->lock
, flags
);
4148 list_for_each_entry_safe(m
, tmp
, &work
, list
) {
4150 __complete_mapping_preparation(m
);
4152 spin_unlock_irqrestore(&pool
->lock
, flags
);
4155 if (h
->all_io_entry
) {
4156 INIT_LIST_HEAD(&work
);
4157 dm_deferred_entry_dec(h
->all_io_entry
, &work
);
4158 if (!list_empty(&work
)) {
4159 spin_lock_irqsave(&pool
->lock
, flags
);
4160 list_for_each_entry_safe(m
, tmp
, &work
, list
)
4161 list_add_tail(&m
->list
, &pool
->prepared_discards
);
4162 spin_unlock_irqrestore(&pool
->lock
, flags
);
4168 cell_defer_no_holder(h
->tc
, h
->cell
);
4173 static void thin_presuspend(struct dm_target
*ti
)
4175 struct thin_c
*tc
= ti
->private;
4177 if (dm_noflush_suspending(ti
))
4178 noflush_work(tc
, do_noflush_start
);
4181 static void thin_postsuspend(struct dm_target
*ti
)
4183 struct thin_c
*tc
= ti
->private;
4186 * The dm_noflush_suspending flag has been cleared by now, so
4187 * unfortunately we must always run this.
4189 noflush_work(tc
, do_noflush_stop
);
4192 static int thin_preresume(struct dm_target
*ti
)
4194 struct thin_c
*tc
= ti
->private;
4197 tc
->origin_size
= get_dev_size(tc
->origin_dev
->bdev
);
4203 * <nr mapped sectors> <highest mapped sector>
4205 static void thin_status(struct dm_target
*ti
, status_type_t type
,
4206 unsigned status_flags
, char *result
, unsigned maxlen
)
4210 dm_block_t mapped
, highest
;
4211 char buf
[BDEVNAME_SIZE
];
4212 struct thin_c
*tc
= ti
->private;
4214 if (get_pool_mode(tc
->pool
) == PM_FAIL
) {
4223 case STATUSTYPE_INFO
:
4224 r
= dm_thin_get_mapped_count(tc
->td
, &mapped
);
4226 DMERR("dm_thin_get_mapped_count returned %d", r
);
4230 r
= dm_thin_get_highest_mapped_block(tc
->td
, &highest
);
4232 DMERR("dm_thin_get_highest_mapped_block returned %d", r
);
4236 DMEMIT("%llu ", mapped
* tc
->pool
->sectors_per_block
);
4238 DMEMIT("%llu", ((highest
+ 1) *
4239 tc
->pool
->sectors_per_block
) - 1);
4244 case STATUSTYPE_TABLE
:
4246 format_dev_t(buf
, tc
->pool_dev
->bdev
->bd_dev
),
4247 (unsigned long) tc
->dev_id
);
4249 DMEMIT(" %s", format_dev_t(buf
, tc
->origin_dev
->bdev
->bd_dev
));
4260 static int thin_merge(struct dm_target
*ti
, struct bvec_merge_data
*bvm
,
4261 struct bio_vec
*biovec
, int max_size
)
4263 struct thin_c
*tc
= ti
->private;
4264 struct request_queue
*q
= bdev_get_queue(tc
->pool_dev
->bdev
);
4266 if (!q
->merge_bvec_fn
)
4269 bvm
->bi_bdev
= tc
->pool_dev
->bdev
;
4270 bvm
->bi_sector
= dm_target_offset(ti
, bvm
->bi_sector
);
4272 return min(max_size
, q
->merge_bvec_fn(q
, bvm
, biovec
));
4275 static int thin_iterate_devices(struct dm_target
*ti
,
4276 iterate_devices_callout_fn fn
, void *data
)
4279 struct thin_c
*tc
= ti
->private;
4280 struct pool
*pool
= tc
->pool
;
4283 * We can't call dm_pool_get_data_dev_size() since that blocks. So
4284 * we follow a more convoluted path through to the pool's target.
4287 return 0; /* nothing is bound */
4289 blocks
= pool
->ti
->len
;
4290 (void) sector_div(blocks
, pool
->sectors_per_block
);
4292 return fn(ti
, tc
->pool_dev
, 0, pool
->sectors_per_block
* blocks
, data
);
4297 static void thin_io_hints(struct dm_target
*ti
, struct queue_limits
*limits
)
4299 struct thin_c
*tc
= ti
->private;
4300 struct pool
*pool
= tc
->pool
;
4302 limits
->discard_granularity
= pool
->sectors_per_block
<< SECTOR_SHIFT
;
4303 limits
->max_discard_sectors
= 2048 * 1024 * 16; /* 16G */
4306 static struct target_type thin_target
= {
4308 .version
= {1, 15, 0},
4309 .module
= THIS_MODULE
,
4313 .end_io
= thin_endio
,
4314 .preresume
= thin_preresume
,
4315 .presuspend
= thin_presuspend
,
4316 .postsuspend
= thin_postsuspend
,
4317 .status
= thin_status
,
4318 .merge
= thin_merge
,
4319 .iterate_devices
= thin_iterate_devices
,
4320 .io_hints
= thin_io_hints
,
4323 /*----------------------------------------------------------------*/
4325 static int __init
dm_thin_init(void)
4331 r
= dm_register_target(&thin_target
);
4335 r
= dm_register_target(&pool_target
);
4337 goto bad_pool_target
;
4341 _new_mapping_cache
= KMEM_CACHE(dm_thin_new_mapping
, 0);
4342 if (!_new_mapping_cache
)
4343 goto bad_new_mapping_cache
;
4347 bad_new_mapping_cache
:
4348 dm_unregister_target(&pool_target
);
4350 dm_unregister_target(&thin_target
);
4355 static void dm_thin_exit(void)
4357 dm_unregister_target(&thin_target
);
4358 dm_unregister_target(&pool_target
);
4360 kmem_cache_destroy(_new_mapping_cache
);
4363 module_init(dm_thin_init
);
4364 module_exit(dm_thin_exit
);
4366 module_param_named(no_space_timeout
, no_space_timeout_secs
, uint
, S_IRUGO
| S_IWUSR
);
4367 MODULE_PARM_DESC(no_space_timeout
, "Out of data space queue IO timeout in seconds");
4369 MODULE_DESCRIPTION(DM_NAME
" thin provisioning target");
4370 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
4371 MODULE_LICENSE("GPL");