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Joe Thornber991d9fa2011-10-31 20:21:18 +00001/*
Joe Thornbere49e5822012-07-27 15:08:16 +01002 * Copyright (C) 2011-2012 Red Hat UK.
Joe Thornber991d9fa2011-10-31 20:21:18 +00003 *
4 * This file is released under the GPL.
5 */
6
7#include "dm-thin-metadata.h"
Mike Snitzer4f81a412012-10-12 21:02:13 +01008#include "dm-bio-prison.h"
Alasdair G Kergon1f4e0ff2012-07-27 15:08:16 +01009#include "dm.h"
Joe Thornber991d9fa2011-10-31 20:21:18 +000010
11#include <linux/device-mapper.h>
12#include <linux/dm-io.h>
13#include <linux/dm-kcopyd.h>
14#include <linux/list.h>
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18
19#define DM_MSG_PREFIX "thin"
20
21/*
22 * Tunable constants
23 */
Alasdair G Kergon7768ed32012-07-27 15:07:57 +010024#define ENDIO_HOOK_POOL_SIZE 1024
Joe Thornber991d9fa2011-10-31 20:21:18 +000025#define MAPPING_POOL_SIZE 1024
26#define PRISON_CELLS 1024
Joe Thornber905e51b2012-03-28 18:41:27 +010027#define COMMIT_PERIOD HZ
Joe Thornber991d9fa2011-10-31 20:21:18 +000028
Mikulas Patockadf5d2e92013-03-01 22:45:49 +000029DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle,
30 "A percentage of time allocated for copy on write");
31
Joe Thornber991d9fa2011-10-31 20:21:18 +000032/*
33 * The block size of the device holding pool data must be
34 * between 64KB and 1GB.
35 */
36#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
37#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
38
39/*
Joe Thornber991d9fa2011-10-31 20:21:18 +000040 * Device id is restricted to 24 bits.
41 */
42#define MAX_DEV_ID ((1 << 24) - 1)
43
44/*
45 * How do we handle breaking sharing of data blocks?
46 * =================================================
47 *
48 * We use a standard copy-on-write btree to store the mappings for the
49 * devices (note I'm talking about copy-on-write of the metadata here, not
50 * the data). When you take an internal snapshot you clone the root node
51 * of the origin btree. After this there is no concept of an origin or a
52 * snapshot. They are just two device trees that happen to point to the
53 * same data blocks.
54 *
55 * When we get a write in we decide if it's to a shared data block using
56 * some timestamp magic. If it is, we have to break sharing.
57 *
58 * Let's say we write to a shared block in what was the origin. The
59 * steps are:
60 *
61 * i) plug io further to this physical block. (see bio_prison code).
62 *
63 * ii) quiesce any read io to that shared data block. Obviously
Mike Snitzer44feb382012-10-12 21:02:10 +010064 * including all devices that share this block. (see dm_deferred_set code)
Joe Thornber991d9fa2011-10-31 20:21:18 +000065 *
66 * iii) copy the data block to a newly allocate block. This step can be
67 * missed out if the io covers the block. (schedule_copy).
68 *
69 * iv) insert the new mapping into the origin's btree
Joe Thornberfe878f32012-03-28 18:41:24 +010070 * (process_prepared_mapping). This act of inserting breaks some
Joe Thornber991d9fa2011-10-31 20:21:18 +000071 * sharing of btree nodes between the two devices. Breaking sharing only
72 * effects the btree of that specific device. Btrees for the other
73 * devices that share the block never change. The btree for the origin
74 * device as it was after the last commit is untouched, ie. we're using
75 * persistent data structures in the functional programming sense.
76 *
77 * v) unplug io to this physical block, including the io that triggered
78 * the breaking of sharing.
79 *
80 * Steps (ii) and (iii) occur in parallel.
81 *
82 * The metadata _doesn't_ need to be committed before the io continues. We
83 * get away with this because the io is always written to a _new_ block.
84 * If there's a crash, then:
85 *
86 * - The origin mapping will point to the old origin block (the shared
87 * one). This will contain the data as it was before the io that triggered
88 * the breaking of sharing came in.
89 *
90 * - The snap mapping still points to the old block. As it would after
91 * the commit.
92 *
93 * The downside of this scheme is the timestamp magic isn't perfect, and
94 * will continue to think that data block in the snapshot device is shared
95 * even after the write to the origin has broken sharing. I suspect data
96 * blocks will typically be shared by many different devices, so we're
97 * breaking sharing n + 1 times, rather than n, where n is the number of
98 * devices that reference this data block. At the moment I think the
99 * benefits far, far outweigh the disadvantages.
100 */
101
102/*----------------------------------------------------------------*/
103
104/*
Joe Thornber991d9fa2011-10-31 20:21:18 +0000105 * Key building.
106 */
107static void build_data_key(struct dm_thin_device *td,
Mike Snitzer44feb382012-10-12 21:02:10 +0100108 dm_block_t b, struct dm_cell_key *key)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000109{
110 key->virtual = 0;
111 key->dev = dm_thin_dev_id(td);
112 key->block = b;
113}
114
115static void build_virtual_key(struct dm_thin_device *td, dm_block_t b,
Mike Snitzer44feb382012-10-12 21:02:10 +0100116 struct dm_cell_key *key)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000117{
118 key->virtual = 1;
119 key->dev = dm_thin_dev_id(td);
120 key->block = b;
121}
122
123/*----------------------------------------------------------------*/
124
125/*
126 * A pool device ties together a metadata device and a data device. It
127 * also provides the interface for creating and destroying internal
128 * devices.
129 */
Mike Snitzera24c2562012-06-03 00:30:00 +0100130struct dm_thin_new_mapping;
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100131
Joe Thornbere49e5822012-07-27 15:08:16 +0100132/*
133 * The pool runs in 3 modes. Ordered in degraded order for comparisons.
134 */
135enum pool_mode {
136 PM_WRITE, /* metadata may be changed */
137 PM_READ_ONLY, /* metadata may not be changed */
138 PM_FAIL, /* all I/O fails */
139};
140
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100141struct pool_features {
Joe Thornbere49e5822012-07-27 15:08:16 +0100142 enum pool_mode mode;
143
Mike Snitzer9bc142d2012-09-26 23:45:46 +0100144 bool zero_new_blocks:1;
145 bool discard_enabled:1;
146 bool discard_passdown:1;
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100147};
148
Joe Thornbere49e5822012-07-27 15:08:16 +0100149struct thin_c;
150typedef void (*process_bio_fn)(struct thin_c *tc, struct bio *bio);
151typedef void (*process_mapping_fn)(struct dm_thin_new_mapping *m);
152
Joe Thornber991d9fa2011-10-31 20:21:18 +0000153struct pool {
154 struct list_head list;
155 struct dm_target *ti; /* Only set if a pool target is bound */
156
157 struct mapped_device *pool_md;
158 struct block_device *md_dev;
159 struct dm_pool_metadata *pmd;
160
Joe Thornber991d9fa2011-10-31 20:21:18 +0000161 dm_block_t low_water_blocks;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100162 uint32_t sectors_per_block;
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100163 int sectors_per_block_shift;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000164
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100165 struct pool_features pf;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000166 unsigned low_water_triggered:1; /* A dm event has been sent */
167 unsigned no_free_space:1; /* A -ENOSPC warning has been issued */
168
Mike Snitzer44feb382012-10-12 21:02:10 +0100169 struct dm_bio_prison *prison;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000170 struct dm_kcopyd_client *copier;
171
172 struct workqueue_struct *wq;
173 struct work_struct worker;
Joe Thornber905e51b2012-03-28 18:41:27 +0100174 struct delayed_work waker;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000175
Joe Thornber905e51b2012-03-28 18:41:27 +0100176 unsigned long last_commit_jiffies;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100177 unsigned ref_count;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000178
179 spinlock_t lock;
180 struct bio_list deferred_bios;
181 struct bio_list deferred_flush_bios;
182 struct list_head prepared_mappings;
Joe Thornber104655f2012-03-28 18:41:28 +0100183 struct list_head prepared_discards;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000184
185 struct bio_list retry_on_resume_list;
186
Mike Snitzer44feb382012-10-12 21:02:10 +0100187 struct dm_deferred_set *shared_read_ds;
188 struct dm_deferred_set *all_io_ds;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000189
Mike Snitzera24c2562012-06-03 00:30:00 +0100190 struct dm_thin_new_mapping *next_mapping;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000191 mempool_t *mapping_pool;
Joe Thornbere49e5822012-07-27 15:08:16 +0100192
193 process_bio_fn process_bio;
194 process_bio_fn process_discard;
195
196 process_mapping_fn process_prepared_mapping;
197 process_mapping_fn process_prepared_discard;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000198};
199
Joe Thornbere49e5822012-07-27 15:08:16 +0100200static enum pool_mode get_pool_mode(struct pool *pool);
201static void set_pool_mode(struct pool *pool, enum pool_mode mode);
202
Joe Thornber991d9fa2011-10-31 20:21:18 +0000203/*
204 * Target context for a pool.
205 */
206struct pool_c {
207 struct dm_target *ti;
208 struct pool *pool;
209 struct dm_dev *data_dev;
210 struct dm_dev *metadata_dev;
211 struct dm_target_callbacks callbacks;
212
213 dm_block_t low_water_blocks;
Mike Snitzer0424caa2012-09-26 23:45:47 +0100214 struct pool_features requested_pf; /* Features requested during table load */
215 struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */
Joe Thornber991d9fa2011-10-31 20:21:18 +0000216};
217
218/*
219 * Target context for a thin.
220 */
221struct thin_c {
222 struct dm_dev *pool_dev;
Joe Thornber2dd9c252012-03-28 18:41:28 +0100223 struct dm_dev *origin_dev;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000224 dm_thin_id dev_id;
225
226 struct pool *pool;
227 struct dm_thin_device *td;
228};
229
230/*----------------------------------------------------------------*/
231
Joe Thornber025b9682013-03-01 22:45:50 +0000232/*
233 * wake_worker() is used when new work is queued and when pool_resume is
234 * ready to continue deferred IO processing.
235 */
236static void wake_worker(struct pool *pool)
237{
238 queue_work(pool->wq, &pool->worker);
239}
240
241/*----------------------------------------------------------------*/
242
Joe Thornber6beca5e2013-03-01 22:45:50 +0000243static int bio_detain(struct pool *pool, struct dm_cell_key *key, struct bio *bio,
244 struct dm_bio_prison_cell **cell_result)
245{
246 int r;
247 struct dm_bio_prison_cell *cell_prealloc;
248
249 /*
250 * Allocate a cell from the prison's mempool.
251 * This might block but it can't fail.
252 */
253 cell_prealloc = dm_bio_prison_alloc_cell(pool->prison, GFP_NOIO);
254
255 r = dm_bio_detain(pool->prison, key, bio, cell_prealloc, cell_result);
256 if (r)
257 /*
258 * We reused an old cell; we can get rid of
259 * the new one.
260 */
261 dm_bio_prison_free_cell(pool->prison, cell_prealloc);
262
263 return r;
264}
265
266static void cell_release(struct pool *pool,
267 struct dm_bio_prison_cell *cell,
268 struct bio_list *bios)
269{
270 dm_cell_release(pool->prison, cell, bios);
271 dm_bio_prison_free_cell(pool->prison, cell);
272}
273
274static void cell_release_no_holder(struct pool *pool,
275 struct dm_bio_prison_cell *cell,
276 struct bio_list *bios)
277{
278 dm_cell_release_no_holder(pool->prison, cell, bios);
279 dm_bio_prison_free_cell(pool->prison, cell);
280}
281
Joe Thornber025b9682013-03-01 22:45:50 +0000282static void cell_defer_no_holder_no_free(struct thin_c *tc,
283 struct dm_bio_prison_cell *cell)
284{
285 struct pool *pool = tc->pool;
286 unsigned long flags;
287
288 spin_lock_irqsave(&pool->lock, flags);
289 dm_cell_release_no_holder(pool->prison, cell, &pool->deferred_bios);
290 spin_unlock_irqrestore(&pool->lock, flags);
291
292 wake_worker(pool);
293}
294
Joe Thornber6beca5e2013-03-01 22:45:50 +0000295static void cell_error(struct pool *pool,
296 struct dm_bio_prison_cell *cell)
297{
298 dm_cell_error(pool->prison, cell);
299 dm_bio_prison_free_cell(pool->prison, cell);
300}
301
302/*----------------------------------------------------------------*/
303
Joe Thornber991d9fa2011-10-31 20:21:18 +0000304/*
305 * A global list of pools that uses a struct mapped_device as a key.
306 */
307static struct dm_thin_pool_table {
308 struct mutex mutex;
309 struct list_head pools;
310} dm_thin_pool_table;
311
312static void pool_table_init(void)
313{
314 mutex_init(&dm_thin_pool_table.mutex);
315 INIT_LIST_HEAD(&dm_thin_pool_table.pools);
316}
317
318static void __pool_table_insert(struct pool *pool)
319{
320 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
321 list_add(&pool->list, &dm_thin_pool_table.pools);
322}
323
324static void __pool_table_remove(struct pool *pool)
325{
326 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
327 list_del(&pool->list);
328}
329
330static struct pool *__pool_table_lookup(struct mapped_device *md)
331{
332 struct pool *pool = NULL, *tmp;
333
334 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
335
336 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
337 if (tmp->pool_md == md) {
338 pool = tmp;
339 break;
340 }
341 }
342
343 return pool;
344}
345
346static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev)
347{
348 struct pool *pool = NULL, *tmp;
349
350 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
351
352 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
353 if (tmp->md_dev == md_dev) {
354 pool = tmp;
355 break;
356 }
357 }
358
359 return pool;
360}
361
362/*----------------------------------------------------------------*/
363
Mike Snitzera24c2562012-06-03 00:30:00 +0100364struct dm_thin_endio_hook {
Joe Thornbereb2aa482012-03-28 18:41:28 +0100365 struct thin_c *tc;
Mike Snitzer44feb382012-10-12 21:02:10 +0100366 struct dm_deferred_entry *shared_read_entry;
367 struct dm_deferred_entry *all_io_entry;
Mike Snitzera24c2562012-06-03 00:30:00 +0100368 struct dm_thin_new_mapping *overwrite_mapping;
Joe Thornbereb2aa482012-03-28 18:41:28 +0100369};
370
Joe Thornber991d9fa2011-10-31 20:21:18 +0000371static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master)
372{
373 struct bio *bio;
374 struct bio_list bios;
375
376 bio_list_init(&bios);
377 bio_list_merge(&bios, master);
378 bio_list_init(master);
379
380 while ((bio = bio_list_pop(&bios))) {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000381 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Mike Snitzera24c2562012-06-03 00:30:00 +0100382
Joe Thornbereb2aa482012-03-28 18:41:28 +0100383 if (h->tc == tc)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000384 bio_endio(bio, DM_ENDIO_REQUEUE);
385 else
386 bio_list_add(master, bio);
387 }
388}
389
390static void requeue_io(struct thin_c *tc)
391{
392 struct pool *pool = tc->pool;
393 unsigned long flags;
394
395 spin_lock_irqsave(&pool->lock, flags);
396 __requeue_bio_list(tc, &pool->deferred_bios);
397 __requeue_bio_list(tc, &pool->retry_on_resume_list);
398 spin_unlock_irqrestore(&pool->lock, flags);
399}
400
401/*
402 * This section of code contains the logic for processing a thin device's IO.
403 * Much of the code depends on pool object resources (lists, workqueues, etc)
404 * but most is exclusively called from the thin target rather than the thin-pool
405 * target.
406 */
407
Mike Snitzer58f77a22013-03-01 22:45:45 +0000408static bool block_size_is_power_of_two(struct pool *pool)
409{
410 return pool->sectors_per_block_shift >= 0;
411}
412
Joe Thornber991d9fa2011-10-31 20:21:18 +0000413static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
414{
Mike Snitzer58f77a22013-03-01 22:45:45 +0000415 struct pool *pool = tc->pool;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100416 sector_t block_nr = bio->bi_sector;
417
Mike Snitzer58f77a22013-03-01 22:45:45 +0000418 if (block_size_is_power_of_two(pool))
419 block_nr >>= pool->sectors_per_block_shift;
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100420 else
Mike Snitzer58f77a22013-03-01 22:45:45 +0000421 (void) sector_div(block_nr, pool->sectors_per_block);
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100422
423 return block_nr;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000424}
425
426static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
427{
428 struct pool *pool = tc->pool;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100429 sector_t bi_sector = bio->bi_sector;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000430
431 bio->bi_bdev = tc->pool_dev->bdev;
Mike Snitzer58f77a22013-03-01 22:45:45 +0000432 if (block_size_is_power_of_two(pool))
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100433 bio->bi_sector = (block << pool->sectors_per_block_shift) |
434 (bi_sector & (pool->sectors_per_block - 1));
Mike Snitzer58f77a22013-03-01 22:45:45 +0000435 else
436 bio->bi_sector = (block * pool->sectors_per_block) +
437 sector_div(bi_sector, pool->sectors_per_block);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000438}
439
Joe Thornber2dd9c252012-03-28 18:41:28 +0100440static void remap_to_origin(struct thin_c *tc, struct bio *bio)
441{
442 bio->bi_bdev = tc->origin_dev->bdev;
443}
444
Joe Thornber4afdd682012-07-27 15:08:14 +0100445static int bio_triggers_commit(struct thin_c *tc, struct bio *bio)
446{
447 return (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) &&
448 dm_thin_changed_this_transaction(tc->td);
449}
450
Joe Thornbere8088072012-12-21 20:23:31 +0000451static void inc_all_io_entry(struct pool *pool, struct bio *bio)
452{
453 struct dm_thin_endio_hook *h;
454
455 if (bio->bi_rw & REQ_DISCARD)
456 return;
457
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000458 h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbere8088072012-12-21 20:23:31 +0000459 h->all_io_entry = dm_deferred_entry_inc(pool->all_io_ds);
460}
461
Joe Thornber2dd9c252012-03-28 18:41:28 +0100462static void issue(struct thin_c *tc, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000463{
464 struct pool *pool = tc->pool;
465 unsigned long flags;
466
Joe Thornbere49e5822012-07-27 15:08:16 +0100467 if (!bio_triggers_commit(tc, bio)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000468 generic_make_request(bio);
Joe Thornbere49e5822012-07-27 15:08:16 +0100469 return;
470 }
471
472 /*
473 * Complete bio with an error if earlier I/O caused changes to
474 * the metadata that can't be committed e.g, due to I/O errors
475 * on the metadata device.
476 */
477 if (dm_thin_aborted_changes(tc->td)) {
478 bio_io_error(bio);
479 return;
480 }
481
482 /*
483 * Batch together any bios that trigger commits and then issue a
484 * single commit for them in process_deferred_bios().
485 */
486 spin_lock_irqsave(&pool->lock, flags);
487 bio_list_add(&pool->deferred_flush_bios, bio);
488 spin_unlock_irqrestore(&pool->lock, flags);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000489}
490
Joe Thornber2dd9c252012-03-28 18:41:28 +0100491static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio)
492{
493 remap_to_origin(tc, bio);
494 issue(tc, bio);
495}
496
497static void remap_and_issue(struct thin_c *tc, struct bio *bio,
498 dm_block_t block)
499{
500 remap(tc, bio, block);
501 issue(tc, bio);
502}
503
Joe Thornber991d9fa2011-10-31 20:21:18 +0000504/*----------------------------------------------------------------*/
505
506/*
507 * Bio endio functions.
508 */
Mike Snitzera24c2562012-06-03 00:30:00 +0100509struct dm_thin_new_mapping {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000510 struct list_head list;
511
Joe Thornbereb2aa482012-03-28 18:41:28 +0100512 unsigned quiesced:1;
513 unsigned prepared:1;
Joe Thornber104655f2012-03-28 18:41:28 +0100514 unsigned pass_discard:1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000515
516 struct thin_c *tc;
517 dm_block_t virt_block;
518 dm_block_t data_block;
Mike Snitzera24c2562012-06-03 00:30:00 +0100519 struct dm_bio_prison_cell *cell, *cell2;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000520 int err;
521
522 /*
523 * If the bio covers the whole area of a block then we can avoid
524 * zeroing or copying. Instead this bio is hooked. The bio will
525 * still be in the cell, so care has to be taken to avoid issuing
526 * the bio twice.
527 */
528 struct bio *bio;
529 bio_end_io_t *saved_bi_end_io;
530};
531
Mike Snitzera24c2562012-06-03 00:30:00 +0100532static void __maybe_add_mapping(struct dm_thin_new_mapping *m)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000533{
534 struct pool *pool = m->tc->pool;
535
Joe Thornbereb2aa482012-03-28 18:41:28 +0100536 if (m->quiesced && m->prepared) {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000537 list_add(&m->list, &pool->prepared_mappings);
538 wake_worker(pool);
539 }
540}
541
542static void copy_complete(int read_err, unsigned long write_err, void *context)
543{
544 unsigned long flags;
Mike Snitzera24c2562012-06-03 00:30:00 +0100545 struct dm_thin_new_mapping *m = context;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000546 struct pool *pool = m->tc->pool;
547
548 m->err = read_err || write_err ? -EIO : 0;
549
550 spin_lock_irqsave(&pool->lock, flags);
551 m->prepared = 1;
552 __maybe_add_mapping(m);
553 spin_unlock_irqrestore(&pool->lock, flags);
554}
555
556static void overwrite_endio(struct bio *bio, int err)
557{
558 unsigned long flags;
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000559 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Mike Snitzera24c2562012-06-03 00:30:00 +0100560 struct dm_thin_new_mapping *m = h->overwrite_mapping;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000561 struct pool *pool = m->tc->pool;
562
563 m->err = err;
564
565 spin_lock_irqsave(&pool->lock, flags);
566 m->prepared = 1;
567 __maybe_add_mapping(m);
568 spin_unlock_irqrestore(&pool->lock, flags);
569}
570
Joe Thornber991d9fa2011-10-31 20:21:18 +0000571/*----------------------------------------------------------------*/
572
573/*
574 * Workqueue.
575 */
576
577/*
578 * Prepared mapping jobs.
579 */
580
581/*
582 * This sends the bios in the cell back to the deferred_bios list.
583 */
Joe Thornber2aab3852012-12-21 20:23:33 +0000584static void cell_defer(struct thin_c *tc, struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000585{
586 struct pool *pool = tc->pool;
587 unsigned long flags;
588
589 spin_lock_irqsave(&pool->lock, flags);
Joe Thornber6beca5e2013-03-01 22:45:50 +0000590 cell_release(pool, cell, &pool->deferred_bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000591 spin_unlock_irqrestore(&tc->pool->lock, flags);
592
593 wake_worker(pool);
594}
595
596/*
Joe Thornber6beca5e2013-03-01 22:45:50 +0000597 * Same as cell_defer above, except it omits the original holder of the cell.
Joe Thornber991d9fa2011-10-31 20:21:18 +0000598 */
Joe Thornberf286ba02012-12-21 20:23:33 +0000599static void cell_defer_no_holder(struct thin_c *tc, struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000600{
Joe Thornber991d9fa2011-10-31 20:21:18 +0000601 struct pool *pool = tc->pool;
602 unsigned long flags;
603
Joe Thornber991d9fa2011-10-31 20:21:18 +0000604 spin_lock_irqsave(&pool->lock, flags);
Joe Thornber6beca5e2013-03-01 22:45:50 +0000605 cell_release_no_holder(pool, cell, &pool->deferred_bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000606 spin_unlock_irqrestore(&pool->lock, flags);
607
608 wake_worker(pool);
609}
610
Joe Thornbere49e5822012-07-27 15:08:16 +0100611static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
612{
613 if (m->bio)
614 m->bio->bi_end_io = m->saved_bi_end_io;
Joe Thornber6beca5e2013-03-01 22:45:50 +0000615 cell_error(m->tc->pool, m->cell);
Joe Thornbere49e5822012-07-27 15:08:16 +0100616 list_del(&m->list);
617 mempool_free(m, m->tc->pool->mapping_pool);
618}
Joe Thornber025b9682013-03-01 22:45:50 +0000619
Mike Snitzera24c2562012-06-03 00:30:00 +0100620static void process_prepared_mapping(struct dm_thin_new_mapping *m)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000621{
622 struct thin_c *tc = m->tc;
Joe Thornber6beca5e2013-03-01 22:45:50 +0000623 struct pool *pool = tc->pool;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000624 struct bio *bio;
625 int r;
626
627 bio = m->bio;
628 if (bio)
629 bio->bi_end_io = m->saved_bi_end_io;
630
631 if (m->err) {
Joe Thornber6beca5e2013-03-01 22:45:50 +0000632 cell_error(pool, m->cell);
Joe Thornber905386f2012-07-27 15:08:05 +0100633 goto out;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000634 }
635
636 /*
637 * Commit the prepared block into the mapping btree.
638 * Any I/O for this block arriving after this point will get
639 * remapped to it directly.
640 */
641 r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);
642 if (r) {
Mike Snitzerc3977412012-12-21 20:23:34 +0000643 DMERR_LIMIT("dm_thin_insert_block() failed");
Joe Thornber6beca5e2013-03-01 22:45:50 +0000644 cell_error(pool, m->cell);
Joe Thornber905386f2012-07-27 15:08:05 +0100645 goto out;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000646 }
647
648 /*
649 * Release any bios held while the block was being provisioned.
650 * If we are processing a write bio that completely covers the block,
651 * we already processed it so can ignore it now when processing
652 * the bios in the cell.
653 */
654 if (bio) {
Joe Thornberf286ba02012-12-21 20:23:33 +0000655 cell_defer_no_holder(tc, m->cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000656 bio_endio(bio, 0);
657 } else
Joe Thornber2aab3852012-12-21 20:23:33 +0000658 cell_defer(tc, m->cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000659
Joe Thornber905386f2012-07-27 15:08:05 +0100660out:
Joe Thornber991d9fa2011-10-31 20:21:18 +0000661 list_del(&m->list);
Joe Thornber6beca5e2013-03-01 22:45:50 +0000662 mempool_free(m, pool->mapping_pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000663}
664
Joe Thornbere49e5822012-07-27 15:08:16 +0100665static void process_prepared_discard_fail(struct dm_thin_new_mapping *m)
Joe Thornber104655f2012-03-28 18:41:28 +0100666{
Joe Thornber104655f2012-03-28 18:41:28 +0100667 struct thin_c *tc = m->tc;
668
Joe Thornbere49e5822012-07-27 15:08:16 +0100669 bio_io_error(m->bio);
Joe Thornberf286ba02012-12-21 20:23:33 +0000670 cell_defer_no_holder(tc, m->cell);
671 cell_defer_no_holder(tc, m->cell2);
Joe Thornbere49e5822012-07-27 15:08:16 +0100672 mempool_free(m, tc->pool->mapping_pool);
673}
Joe Thornber104655f2012-03-28 18:41:28 +0100674
Joe Thornbere49e5822012-07-27 15:08:16 +0100675static void process_prepared_discard_passdown(struct dm_thin_new_mapping *m)
676{
677 struct thin_c *tc = m->tc;
678
Joe Thornbere8088072012-12-21 20:23:31 +0000679 inc_all_io_entry(tc->pool, m->bio);
Joe Thornberf286ba02012-12-21 20:23:33 +0000680 cell_defer_no_holder(tc, m->cell);
681 cell_defer_no_holder(tc, m->cell2);
Joe Thornbere8088072012-12-21 20:23:31 +0000682
Joe Thornber104655f2012-03-28 18:41:28 +0100683 if (m->pass_discard)
684 remap_and_issue(tc, m->bio, m->data_block);
685 else
686 bio_endio(m->bio, 0);
687
Joe Thornber104655f2012-03-28 18:41:28 +0100688 mempool_free(m, tc->pool->mapping_pool);
689}
690
Joe Thornbere49e5822012-07-27 15:08:16 +0100691static void process_prepared_discard(struct dm_thin_new_mapping *m)
692{
693 int r;
694 struct thin_c *tc = m->tc;
695
696 r = dm_thin_remove_block(tc->td, m->virt_block);
697 if (r)
Mike Snitzerc3977412012-12-21 20:23:34 +0000698 DMERR_LIMIT("dm_thin_remove_block() failed");
Joe Thornbere49e5822012-07-27 15:08:16 +0100699
700 process_prepared_discard_passdown(m);
701}
702
Joe Thornber104655f2012-03-28 18:41:28 +0100703static void process_prepared(struct pool *pool, struct list_head *head,
Joe Thornbere49e5822012-07-27 15:08:16 +0100704 process_mapping_fn *fn)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000705{
706 unsigned long flags;
707 struct list_head maps;
Mike Snitzera24c2562012-06-03 00:30:00 +0100708 struct dm_thin_new_mapping *m, *tmp;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000709
710 INIT_LIST_HEAD(&maps);
711 spin_lock_irqsave(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +0100712 list_splice_init(head, &maps);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000713 spin_unlock_irqrestore(&pool->lock, flags);
714
715 list_for_each_entry_safe(m, tmp, &maps, list)
Joe Thornbere49e5822012-07-27 15:08:16 +0100716 (*fn)(m);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000717}
718
719/*
720 * Deferred bio jobs.
721 */
Joe Thornber104655f2012-03-28 18:41:28 +0100722static int io_overlaps_block(struct pool *pool, struct bio *bio)
723{
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100724 return bio->bi_size == (pool->sectors_per_block << SECTOR_SHIFT);
Joe Thornber104655f2012-03-28 18:41:28 +0100725}
726
Joe Thornber991d9fa2011-10-31 20:21:18 +0000727static int io_overwrites_block(struct pool *pool, struct bio *bio)
728{
Joe Thornber104655f2012-03-28 18:41:28 +0100729 return (bio_data_dir(bio) == WRITE) &&
730 io_overlaps_block(pool, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000731}
732
733static void save_and_set_endio(struct bio *bio, bio_end_io_t **save,
734 bio_end_io_t *fn)
735{
736 *save = bio->bi_end_io;
737 bio->bi_end_io = fn;
738}
739
740static int ensure_next_mapping(struct pool *pool)
741{
742 if (pool->next_mapping)
743 return 0;
744
745 pool->next_mapping = mempool_alloc(pool->mapping_pool, GFP_ATOMIC);
746
747 return pool->next_mapping ? 0 : -ENOMEM;
748}
749
Mike Snitzera24c2562012-06-03 00:30:00 +0100750static struct dm_thin_new_mapping *get_next_mapping(struct pool *pool)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000751{
Mike Snitzera24c2562012-06-03 00:30:00 +0100752 struct dm_thin_new_mapping *r = pool->next_mapping;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000753
754 BUG_ON(!pool->next_mapping);
755
756 pool->next_mapping = NULL;
757
758 return r;
759}
760
761static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
Joe Thornber2dd9c252012-03-28 18:41:28 +0100762 struct dm_dev *origin, dm_block_t data_origin,
763 dm_block_t data_dest,
Mike Snitzera24c2562012-06-03 00:30:00 +0100764 struct dm_bio_prison_cell *cell, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000765{
766 int r;
767 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +0100768 struct dm_thin_new_mapping *m = get_next_mapping(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000769
770 INIT_LIST_HEAD(&m->list);
Joe Thornbereb2aa482012-03-28 18:41:28 +0100771 m->quiesced = 0;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000772 m->prepared = 0;
773 m->tc = tc;
774 m->virt_block = virt_block;
775 m->data_block = data_dest;
776 m->cell = cell;
777 m->err = 0;
778 m->bio = NULL;
779
Mike Snitzer44feb382012-10-12 21:02:10 +0100780 if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list))
Joe Thornbereb2aa482012-03-28 18:41:28 +0100781 m->quiesced = 1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000782
783 /*
784 * IO to pool_dev remaps to the pool target's data_dev.
785 *
786 * If the whole block of data is being overwritten, we can issue the
787 * bio immediately. Otherwise we use kcopyd to clone the data first.
788 */
789 if (io_overwrites_block(pool, bio)) {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000790 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Mike Snitzera24c2562012-06-03 00:30:00 +0100791
Joe Thornbereb2aa482012-03-28 18:41:28 +0100792 h->overwrite_mapping = m;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000793 m->bio = bio;
794 save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
Joe Thornbere8088072012-12-21 20:23:31 +0000795 inc_all_io_entry(pool, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000796 remap_and_issue(tc, bio, data_dest);
797 } else {
798 struct dm_io_region from, to;
799
Joe Thornber2dd9c252012-03-28 18:41:28 +0100800 from.bdev = origin->bdev;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000801 from.sector = data_origin * pool->sectors_per_block;
802 from.count = pool->sectors_per_block;
803
804 to.bdev = tc->pool_dev->bdev;
805 to.sector = data_dest * pool->sectors_per_block;
806 to.count = pool->sectors_per_block;
807
808 r = dm_kcopyd_copy(pool->copier, &from, 1, &to,
809 0, copy_complete, m);
810 if (r < 0) {
811 mempool_free(m, pool->mapping_pool);
Mike Snitzerc3977412012-12-21 20:23:34 +0000812 DMERR_LIMIT("dm_kcopyd_copy() failed");
Joe Thornber6beca5e2013-03-01 22:45:50 +0000813 cell_error(pool, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000814 }
815 }
816}
817
Joe Thornber2dd9c252012-03-28 18:41:28 +0100818static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block,
819 dm_block_t data_origin, dm_block_t data_dest,
Mike Snitzera24c2562012-06-03 00:30:00 +0100820 struct dm_bio_prison_cell *cell, struct bio *bio)
Joe Thornber2dd9c252012-03-28 18:41:28 +0100821{
822 schedule_copy(tc, virt_block, tc->pool_dev,
823 data_origin, data_dest, cell, bio);
824}
825
826static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block,
827 dm_block_t data_dest,
Mike Snitzera24c2562012-06-03 00:30:00 +0100828 struct dm_bio_prison_cell *cell, struct bio *bio)
Joe Thornber2dd9c252012-03-28 18:41:28 +0100829{
830 schedule_copy(tc, virt_block, tc->origin_dev,
831 virt_block, data_dest, cell, bio);
832}
833
Joe Thornber991d9fa2011-10-31 20:21:18 +0000834static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
Mike Snitzera24c2562012-06-03 00:30:00 +0100835 dm_block_t data_block, struct dm_bio_prison_cell *cell,
Joe Thornber991d9fa2011-10-31 20:21:18 +0000836 struct bio *bio)
837{
838 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +0100839 struct dm_thin_new_mapping *m = get_next_mapping(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000840
841 INIT_LIST_HEAD(&m->list);
Joe Thornbereb2aa482012-03-28 18:41:28 +0100842 m->quiesced = 1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000843 m->prepared = 0;
844 m->tc = tc;
845 m->virt_block = virt_block;
846 m->data_block = data_block;
847 m->cell = cell;
848 m->err = 0;
849 m->bio = NULL;
850
851 /*
852 * If the whole block of data is being overwritten or we are not
853 * zeroing pre-existing data, we can issue the bio immediately.
854 * Otherwise we use kcopyd to zero the data first.
855 */
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100856 if (!pool->pf.zero_new_blocks)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000857 process_prepared_mapping(m);
858
859 else if (io_overwrites_block(pool, bio)) {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000860 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Mike Snitzera24c2562012-06-03 00:30:00 +0100861
Joe Thornbereb2aa482012-03-28 18:41:28 +0100862 h->overwrite_mapping = m;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000863 m->bio = bio;
864 save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
Joe Thornbere8088072012-12-21 20:23:31 +0000865 inc_all_io_entry(pool, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000866 remap_and_issue(tc, bio, data_block);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000867 } else {
868 int r;
869 struct dm_io_region to;
870
871 to.bdev = tc->pool_dev->bdev;
872 to.sector = data_block * pool->sectors_per_block;
873 to.count = pool->sectors_per_block;
874
875 r = dm_kcopyd_zero(pool->copier, 1, &to, 0, copy_complete, m);
876 if (r < 0) {
877 mempool_free(m, pool->mapping_pool);
Mike Snitzerc3977412012-12-21 20:23:34 +0000878 DMERR_LIMIT("dm_kcopyd_zero() failed");
Joe Thornber6beca5e2013-03-01 22:45:50 +0000879 cell_error(pool, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000880 }
881 }
882}
883
Joe Thornbere49e5822012-07-27 15:08:16 +0100884static int commit(struct pool *pool)
885{
886 int r;
887
888 r = dm_pool_commit_metadata(pool->pmd);
889 if (r)
Mike Snitzerc3977412012-12-21 20:23:34 +0000890 DMERR_LIMIT("commit failed: error = %d", r);
Joe Thornbere49e5822012-07-27 15:08:16 +0100891
892 return r;
893}
894
895/*
896 * A non-zero return indicates read_only or fail_io mode.
897 * Many callers don't care about the return value.
898 */
899static int commit_or_fallback(struct pool *pool)
900{
901 int r;
902
903 if (get_pool_mode(pool) != PM_WRITE)
904 return -EINVAL;
905
906 r = commit(pool);
907 if (r)
908 set_pool_mode(pool, PM_READ_ONLY);
909
910 return r;
911}
912
Joe Thornber991d9fa2011-10-31 20:21:18 +0000913static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
914{
915 int r;
916 dm_block_t free_blocks;
917 unsigned long flags;
918 struct pool *pool = tc->pool;
919
920 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
921 if (r)
922 return r;
923
924 if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) {
Joe Thornberb17446d2013-05-10 14:37:18 +0100925 DMWARN("%s: reached low water mark for data device: sending event.",
Joe Thornber991d9fa2011-10-31 20:21:18 +0000926 dm_device_name(pool->pool_md));
927 spin_lock_irqsave(&pool->lock, flags);
928 pool->low_water_triggered = 1;
929 spin_unlock_irqrestore(&pool->lock, flags);
930 dm_table_event(pool->ti->table);
931 }
932
933 if (!free_blocks) {
934 if (pool->no_free_space)
935 return -ENOSPC;
936 else {
937 /*
938 * Try to commit to see if that will free up some
939 * more space.
940 */
Joe Thornbere49e5822012-07-27 15:08:16 +0100941 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000942
943 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
944 if (r)
945 return r;
946
947 /*
948 * If we still have no space we set a flag to avoid
949 * doing all this checking and return -ENOSPC.
950 */
951 if (!free_blocks) {
952 DMWARN("%s: no free space available.",
953 dm_device_name(pool->pool_md));
954 spin_lock_irqsave(&pool->lock, flags);
955 pool->no_free_space = 1;
956 spin_unlock_irqrestore(&pool->lock, flags);
957 return -ENOSPC;
958 }
959 }
960 }
961
962 r = dm_pool_alloc_data_block(pool->pmd, result);
963 if (r)
964 return r;
965
966 return 0;
967}
968
969/*
970 * If we have run out of space, queue bios until the device is
971 * resumed, presumably after having been reloaded with more space.
972 */
973static void retry_on_resume(struct bio *bio)
974{
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000975 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbereb2aa482012-03-28 18:41:28 +0100976 struct thin_c *tc = h->tc;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000977 struct pool *pool = tc->pool;
978 unsigned long flags;
979
980 spin_lock_irqsave(&pool->lock, flags);
981 bio_list_add(&pool->retry_on_resume_list, bio);
982 spin_unlock_irqrestore(&pool->lock, flags);
983}
984
Joe Thornber6beca5e2013-03-01 22:45:50 +0000985static void no_space(struct pool *pool, struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000986{
987 struct bio *bio;
988 struct bio_list bios;
989
990 bio_list_init(&bios);
Joe Thornber6beca5e2013-03-01 22:45:50 +0000991 cell_release(pool, cell, &bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000992
993 while ((bio = bio_list_pop(&bios)))
994 retry_on_resume(bio);
995}
996
Joe Thornber104655f2012-03-28 18:41:28 +0100997static void process_discard(struct thin_c *tc, struct bio *bio)
998{
999 int r;
Mike Snitzerc3a0ce22012-05-12 01:43:16 +01001000 unsigned long flags;
Joe Thornber104655f2012-03-28 18:41:28 +01001001 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +01001002 struct dm_bio_prison_cell *cell, *cell2;
Mike Snitzer44feb382012-10-12 21:02:10 +01001003 struct dm_cell_key key, key2;
Joe Thornber104655f2012-03-28 18:41:28 +01001004 dm_block_t block = get_bio_block(tc, bio);
1005 struct dm_thin_lookup_result lookup_result;
Mike Snitzera24c2562012-06-03 00:30:00 +01001006 struct dm_thin_new_mapping *m;
Joe Thornber104655f2012-03-28 18:41:28 +01001007
1008 build_virtual_key(tc->td, block, &key);
Joe Thornber6beca5e2013-03-01 22:45:50 +00001009 if (bio_detain(tc->pool, &key, bio, &cell))
Joe Thornber104655f2012-03-28 18:41:28 +01001010 return;
1011
1012 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1013 switch (r) {
1014 case 0:
1015 /*
1016 * Check nobody is fiddling with this pool block. This can
1017 * happen if someone's in the process of breaking sharing
1018 * on this block.
1019 */
1020 build_data_key(tc->td, lookup_result.block, &key2);
Joe Thornber6beca5e2013-03-01 22:45:50 +00001021 if (bio_detain(tc->pool, &key2, bio, &cell2)) {
Joe Thornberf286ba02012-12-21 20:23:33 +00001022 cell_defer_no_holder(tc, cell);
Joe Thornber104655f2012-03-28 18:41:28 +01001023 break;
1024 }
1025
1026 if (io_overlaps_block(pool, bio)) {
1027 /*
1028 * IO may still be going to the destination block. We must
1029 * quiesce before we can do the removal.
1030 */
1031 m = get_next_mapping(pool);
1032 m->tc = tc;
Mike Snitzer17b7d632012-07-27 15:07:57 +01001033 m->pass_discard = (!lookup_result.shared) && pool->pf.discard_passdown;
Joe Thornber104655f2012-03-28 18:41:28 +01001034 m->virt_block = block;
1035 m->data_block = lookup_result.block;
1036 m->cell = cell;
1037 m->cell2 = cell2;
1038 m->err = 0;
1039 m->bio = bio;
1040
Mike Snitzer44feb382012-10-12 21:02:10 +01001041 if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) {
Mike Snitzerc3a0ce22012-05-12 01:43:16 +01001042 spin_lock_irqsave(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +01001043 list_add(&m->list, &pool->prepared_discards);
Mike Snitzerc3a0ce22012-05-12 01:43:16 +01001044 spin_unlock_irqrestore(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +01001045 wake_worker(pool);
1046 }
1047 } else {
Joe Thornbere8088072012-12-21 20:23:31 +00001048 inc_all_io_entry(pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001049 cell_defer_no_holder(tc, cell);
1050 cell_defer_no_holder(tc, cell2);
Joe Thornbere8088072012-12-21 20:23:31 +00001051
Joe Thornber104655f2012-03-28 18:41:28 +01001052 /*
Mikulas Patocka49296302012-07-27 15:08:03 +01001053 * The DM core makes sure that the discard doesn't span
1054 * a block boundary. So we submit the discard of a
1055 * partial block appropriately.
Joe Thornber104655f2012-03-28 18:41:28 +01001056 */
Mikulas Patocka650d2a02012-07-20 14:25:05 +01001057 if ((!lookup_result.shared) && pool->pf.discard_passdown)
1058 remap_and_issue(tc, bio, lookup_result.block);
1059 else
1060 bio_endio(bio, 0);
Joe Thornber104655f2012-03-28 18:41:28 +01001061 }
1062 break;
1063
1064 case -ENODATA:
1065 /*
1066 * It isn't provisioned, just forget it.
1067 */
Joe Thornberf286ba02012-12-21 20:23:33 +00001068 cell_defer_no_holder(tc, cell);
Joe Thornber104655f2012-03-28 18:41:28 +01001069 bio_endio(bio, 0);
1070 break;
1071
1072 default:
Mike Snitzerc3977412012-12-21 20:23:34 +00001073 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1074 __func__, r);
Joe Thornberf286ba02012-12-21 20:23:33 +00001075 cell_defer_no_holder(tc, cell);
Joe Thornber104655f2012-03-28 18:41:28 +01001076 bio_io_error(bio);
1077 break;
1078 }
1079}
1080
Joe Thornber991d9fa2011-10-31 20:21:18 +00001081static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
Mike Snitzer44feb382012-10-12 21:02:10 +01001082 struct dm_cell_key *key,
Joe Thornber991d9fa2011-10-31 20:21:18 +00001083 struct dm_thin_lookup_result *lookup_result,
Mike Snitzera24c2562012-06-03 00:30:00 +01001084 struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001085{
1086 int r;
1087 dm_block_t data_block;
1088
1089 r = alloc_data_block(tc, &data_block);
1090 switch (r) {
1091 case 0:
Joe Thornber2dd9c252012-03-28 18:41:28 +01001092 schedule_internal_copy(tc, block, lookup_result->block,
1093 data_block, cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001094 break;
1095
1096 case -ENOSPC:
Joe Thornber6beca5e2013-03-01 22:45:50 +00001097 no_space(tc->pool, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001098 break;
1099
1100 default:
Mike Snitzerc3977412012-12-21 20:23:34 +00001101 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1102 __func__, r);
Joe Thornber6beca5e2013-03-01 22:45:50 +00001103 cell_error(tc->pool, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001104 break;
1105 }
1106}
1107
1108static void process_shared_bio(struct thin_c *tc, struct bio *bio,
1109 dm_block_t block,
1110 struct dm_thin_lookup_result *lookup_result)
1111{
Mike Snitzera24c2562012-06-03 00:30:00 +01001112 struct dm_bio_prison_cell *cell;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001113 struct pool *pool = tc->pool;
Mike Snitzer44feb382012-10-12 21:02:10 +01001114 struct dm_cell_key key;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001115
1116 /*
1117 * If cell is already occupied, then sharing is already in the process
1118 * of being broken so we have nothing further to do here.
1119 */
1120 build_data_key(tc->td, lookup_result->block, &key);
Joe Thornber6beca5e2013-03-01 22:45:50 +00001121 if (bio_detain(pool, &key, bio, &cell))
Joe Thornber991d9fa2011-10-31 20:21:18 +00001122 return;
1123
Joe Thornber60049702012-07-27 15:08:06 +01001124 if (bio_data_dir(bio) == WRITE && bio->bi_size)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001125 break_sharing(tc, bio, block, &key, lookup_result, cell);
1126 else {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001127 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornber991d9fa2011-10-31 20:21:18 +00001128
Mike Snitzer44feb382012-10-12 21:02:10 +01001129 h->shared_read_entry = dm_deferred_entry_inc(pool->shared_read_ds);
Joe Thornbere8088072012-12-21 20:23:31 +00001130 inc_all_io_entry(pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001131 cell_defer_no_holder(tc, cell);
Joe Thornbere8088072012-12-21 20:23:31 +00001132
Joe Thornber991d9fa2011-10-31 20:21:18 +00001133 remap_and_issue(tc, bio, lookup_result->block);
1134 }
1135}
1136
1137static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block,
Mike Snitzera24c2562012-06-03 00:30:00 +01001138 struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001139{
1140 int r;
1141 dm_block_t data_block;
Joe Thornber6beca5e2013-03-01 22:45:50 +00001142 struct pool *pool = tc->pool;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001143
1144 /*
1145 * Remap empty bios (flushes) immediately, without provisioning.
1146 */
1147 if (!bio->bi_size) {
Joe Thornber6beca5e2013-03-01 22:45:50 +00001148 inc_all_io_entry(pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001149 cell_defer_no_holder(tc, cell);
Joe Thornbere8088072012-12-21 20:23:31 +00001150
Joe Thornber991d9fa2011-10-31 20:21:18 +00001151 remap_and_issue(tc, bio, 0);
1152 return;
1153 }
1154
1155 /*
1156 * Fill read bios with zeroes and complete them immediately.
1157 */
1158 if (bio_data_dir(bio) == READ) {
1159 zero_fill_bio(bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001160 cell_defer_no_holder(tc, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001161 bio_endio(bio, 0);
1162 return;
1163 }
1164
1165 r = alloc_data_block(tc, &data_block);
1166 switch (r) {
1167 case 0:
Joe Thornber2dd9c252012-03-28 18:41:28 +01001168 if (tc->origin_dev)
1169 schedule_external_copy(tc, block, data_block, cell, bio);
1170 else
1171 schedule_zero(tc, block, data_block, cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001172 break;
1173
1174 case -ENOSPC:
Joe Thornber6beca5e2013-03-01 22:45:50 +00001175 no_space(pool, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001176 break;
1177
1178 default:
Mike Snitzerc3977412012-12-21 20:23:34 +00001179 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1180 __func__, r);
Joe Thornber6beca5e2013-03-01 22:45:50 +00001181 set_pool_mode(pool, PM_READ_ONLY);
1182 cell_error(pool, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001183 break;
1184 }
1185}
1186
1187static void process_bio(struct thin_c *tc, struct bio *bio)
1188{
1189 int r;
Joe Thornber6beca5e2013-03-01 22:45:50 +00001190 struct pool *pool = tc->pool;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001191 dm_block_t block = get_bio_block(tc, bio);
Mike Snitzera24c2562012-06-03 00:30:00 +01001192 struct dm_bio_prison_cell *cell;
Mike Snitzer44feb382012-10-12 21:02:10 +01001193 struct dm_cell_key key;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001194 struct dm_thin_lookup_result lookup_result;
1195
1196 /*
1197 * If cell is already occupied, then the block is already
1198 * being provisioned so we have nothing further to do here.
1199 */
1200 build_virtual_key(tc->td, block, &key);
Joe Thornber6beca5e2013-03-01 22:45:50 +00001201 if (bio_detain(pool, &key, bio, &cell))
Joe Thornber991d9fa2011-10-31 20:21:18 +00001202 return;
1203
1204 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1205 switch (r) {
1206 case 0:
Joe Thornbere8088072012-12-21 20:23:31 +00001207 if (lookup_result.shared) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001208 process_shared_bio(tc, bio, block, &lookup_result);
Joe Thornber6beca5e2013-03-01 22:45:50 +00001209 cell_defer_no_holder(tc, cell); /* FIXME: pass this cell into process_shared? */
Joe Thornbere8088072012-12-21 20:23:31 +00001210 } else {
Joe Thornber6beca5e2013-03-01 22:45:50 +00001211 inc_all_io_entry(pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001212 cell_defer_no_holder(tc, cell);
Joe Thornbere8088072012-12-21 20:23:31 +00001213
Joe Thornber991d9fa2011-10-31 20:21:18 +00001214 remap_and_issue(tc, bio, lookup_result.block);
Joe Thornbere8088072012-12-21 20:23:31 +00001215 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001216 break;
1217
1218 case -ENODATA:
Joe Thornber2dd9c252012-03-28 18:41:28 +01001219 if (bio_data_dir(bio) == READ && tc->origin_dev) {
Joe Thornber6beca5e2013-03-01 22:45:50 +00001220 inc_all_io_entry(pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001221 cell_defer_no_holder(tc, cell);
Joe Thornbere8088072012-12-21 20:23:31 +00001222
Joe Thornber2dd9c252012-03-28 18:41:28 +01001223 remap_to_origin_and_issue(tc, bio);
1224 } else
1225 provision_block(tc, bio, block, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001226 break;
1227
1228 default:
Mike Snitzerc3977412012-12-21 20:23:34 +00001229 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1230 __func__, r);
Joe Thornberf286ba02012-12-21 20:23:33 +00001231 cell_defer_no_holder(tc, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001232 bio_io_error(bio);
1233 break;
1234 }
1235}
1236
Joe Thornbere49e5822012-07-27 15:08:16 +01001237static void process_bio_read_only(struct thin_c *tc, struct bio *bio)
1238{
1239 int r;
1240 int rw = bio_data_dir(bio);
1241 dm_block_t block = get_bio_block(tc, bio);
1242 struct dm_thin_lookup_result lookup_result;
1243
1244 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1245 switch (r) {
1246 case 0:
1247 if (lookup_result.shared && (rw == WRITE) && bio->bi_size)
1248 bio_io_error(bio);
Joe Thornbere8088072012-12-21 20:23:31 +00001249 else {
1250 inc_all_io_entry(tc->pool, bio);
Joe Thornbere49e5822012-07-27 15:08:16 +01001251 remap_and_issue(tc, bio, lookup_result.block);
Joe Thornbere8088072012-12-21 20:23:31 +00001252 }
Joe Thornbere49e5822012-07-27 15:08:16 +01001253 break;
1254
1255 case -ENODATA:
1256 if (rw != READ) {
1257 bio_io_error(bio);
1258 break;
1259 }
1260
1261 if (tc->origin_dev) {
Joe Thornbere8088072012-12-21 20:23:31 +00001262 inc_all_io_entry(tc->pool, bio);
Joe Thornbere49e5822012-07-27 15:08:16 +01001263 remap_to_origin_and_issue(tc, bio);
1264 break;
1265 }
1266
1267 zero_fill_bio(bio);
1268 bio_endio(bio, 0);
1269 break;
1270
1271 default:
Mike Snitzerc3977412012-12-21 20:23:34 +00001272 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1273 __func__, r);
Joe Thornbere49e5822012-07-27 15:08:16 +01001274 bio_io_error(bio);
1275 break;
1276 }
1277}
1278
1279static void process_bio_fail(struct thin_c *tc, struct bio *bio)
1280{
1281 bio_io_error(bio);
1282}
1283
Joe Thornberac8c3f32013-05-10 14:37:21 +01001284/*
1285 * FIXME: should we also commit due to size of transaction, measured in
1286 * metadata blocks?
1287 */
Joe Thornber905e51b2012-03-28 18:41:27 +01001288static int need_commit_due_to_time(struct pool *pool)
1289{
1290 return jiffies < pool->last_commit_jiffies ||
1291 jiffies > pool->last_commit_jiffies + COMMIT_PERIOD;
1292}
1293
Joe Thornber991d9fa2011-10-31 20:21:18 +00001294static void process_deferred_bios(struct pool *pool)
1295{
1296 unsigned long flags;
1297 struct bio *bio;
1298 struct bio_list bios;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001299
1300 bio_list_init(&bios);
1301
1302 spin_lock_irqsave(&pool->lock, flags);
1303 bio_list_merge(&bios, &pool->deferred_bios);
1304 bio_list_init(&pool->deferred_bios);
1305 spin_unlock_irqrestore(&pool->lock, flags);
1306
1307 while ((bio = bio_list_pop(&bios))) {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001308 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbereb2aa482012-03-28 18:41:28 +01001309 struct thin_c *tc = h->tc;
1310
Joe Thornber991d9fa2011-10-31 20:21:18 +00001311 /*
1312 * If we've got no free new_mapping structs, and processing
1313 * this bio might require one, we pause until there are some
1314 * prepared mappings to process.
1315 */
1316 if (ensure_next_mapping(pool)) {
1317 spin_lock_irqsave(&pool->lock, flags);
1318 bio_list_merge(&pool->deferred_bios, &bios);
1319 spin_unlock_irqrestore(&pool->lock, flags);
1320
1321 break;
1322 }
Joe Thornber104655f2012-03-28 18:41:28 +01001323
1324 if (bio->bi_rw & REQ_DISCARD)
Joe Thornbere49e5822012-07-27 15:08:16 +01001325 pool->process_discard(tc, bio);
Joe Thornber104655f2012-03-28 18:41:28 +01001326 else
Joe Thornbere49e5822012-07-27 15:08:16 +01001327 pool->process_bio(tc, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001328 }
1329
1330 /*
1331 * If there are any deferred flush bios, we must commit
1332 * the metadata before issuing them.
1333 */
1334 bio_list_init(&bios);
1335 spin_lock_irqsave(&pool->lock, flags);
1336 bio_list_merge(&bios, &pool->deferred_flush_bios);
1337 bio_list_init(&pool->deferred_flush_bios);
1338 spin_unlock_irqrestore(&pool->lock, flags);
1339
Joe Thornber905e51b2012-03-28 18:41:27 +01001340 if (bio_list_empty(&bios) && !need_commit_due_to_time(pool))
Joe Thornber991d9fa2011-10-31 20:21:18 +00001341 return;
1342
Joe Thornbere49e5822012-07-27 15:08:16 +01001343 if (commit_or_fallback(pool)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001344 while ((bio = bio_list_pop(&bios)))
1345 bio_io_error(bio);
1346 return;
1347 }
Joe Thornber905e51b2012-03-28 18:41:27 +01001348 pool->last_commit_jiffies = jiffies;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001349
1350 while ((bio = bio_list_pop(&bios)))
1351 generic_make_request(bio);
1352}
1353
1354static void do_worker(struct work_struct *ws)
1355{
1356 struct pool *pool = container_of(ws, struct pool, worker);
1357
Joe Thornbere49e5822012-07-27 15:08:16 +01001358 process_prepared(pool, &pool->prepared_mappings, &pool->process_prepared_mapping);
1359 process_prepared(pool, &pool->prepared_discards, &pool->process_prepared_discard);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001360 process_deferred_bios(pool);
1361}
1362
Joe Thornber905e51b2012-03-28 18:41:27 +01001363/*
1364 * We want to commit periodically so that not too much
1365 * unwritten data builds up.
1366 */
1367static void do_waker(struct work_struct *ws)
1368{
1369 struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker);
1370 wake_worker(pool);
1371 queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD);
1372}
1373
Joe Thornber991d9fa2011-10-31 20:21:18 +00001374/*----------------------------------------------------------------*/
1375
Joe Thornbere49e5822012-07-27 15:08:16 +01001376static enum pool_mode get_pool_mode(struct pool *pool)
1377{
1378 return pool->pf.mode;
1379}
1380
1381static void set_pool_mode(struct pool *pool, enum pool_mode mode)
1382{
1383 int r;
1384
1385 pool->pf.mode = mode;
1386
1387 switch (mode) {
1388 case PM_FAIL:
1389 DMERR("switching pool to failure mode");
1390 pool->process_bio = process_bio_fail;
1391 pool->process_discard = process_bio_fail;
1392 pool->process_prepared_mapping = process_prepared_mapping_fail;
1393 pool->process_prepared_discard = process_prepared_discard_fail;
1394 break;
1395
1396 case PM_READ_ONLY:
1397 DMERR("switching pool to read-only mode");
1398 r = dm_pool_abort_metadata(pool->pmd);
1399 if (r) {
1400 DMERR("aborting transaction failed");
1401 set_pool_mode(pool, PM_FAIL);
1402 } else {
1403 dm_pool_metadata_read_only(pool->pmd);
1404 pool->process_bio = process_bio_read_only;
1405 pool->process_discard = process_discard;
1406 pool->process_prepared_mapping = process_prepared_mapping_fail;
1407 pool->process_prepared_discard = process_prepared_discard_passdown;
1408 }
1409 break;
1410
1411 case PM_WRITE:
1412 pool->process_bio = process_bio;
1413 pool->process_discard = process_discard;
1414 pool->process_prepared_mapping = process_prepared_mapping;
1415 pool->process_prepared_discard = process_prepared_discard;
1416 break;
1417 }
1418}
1419
1420/*----------------------------------------------------------------*/
1421
Joe Thornber991d9fa2011-10-31 20:21:18 +00001422/*
1423 * Mapping functions.
1424 */
1425
1426/*
1427 * Called only while mapping a thin bio to hand it over to the workqueue.
1428 */
1429static void thin_defer_bio(struct thin_c *tc, struct bio *bio)
1430{
1431 unsigned long flags;
1432 struct pool *pool = tc->pool;
1433
1434 spin_lock_irqsave(&pool->lock, flags);
1435 bio_list_add(&pool->deferred_bios, bio);
1436 spin_unlock_irqrestore(&pool->lock, flags);
1437
1438 wake_worker(pool);
1439}
1440
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001441static void thin_hook_bio(struct thin_c *tc, struct bio *bio)
Joe Thornbereb2aa482012-03-28 18:41:28 +01001442{
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001443 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbereb2aa482012-03-28 18:41:28 +01001444
1445 h->tc = tc;
1446 h->shared_read_entry = NULL;
Joe Thornbere8088072012-12-21 20:23:31 +00001447 h->all_io_entry = NULL;
Joe Thornbereb2aa482012-03-28 18:41:28 +01001448 h->overwrite_mapping = NULL;
Joe Thornbereb2aa482012-03-28 18:41:28 +01001449}
1450
Joe Thornber991d9fa2011-10-31 20:21:18 +00001451/*
1452 * Non-blocking function called from the thin target's map function.
1453 */
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00001454static int thin_bio_map(struct dm_target *ti, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001455{
1456 int r;
1457 struct thin_c *tc = ti->private;
1458 dm_block_t block = get_bio_block(tc, bio);
1459 struct dm_thin_device *td = tc->td;
1460 struct dm_thin_lookup_result result;
Joe Thornber025b9682013-03-01 22:45:50 +00001461 struct dm_bio_prison_cell cell1, cell2;
1462 struct dm_bio_prison_cell *cell_result;
Joe Thornbere8088072012-12-21 20:23:31 +00001463 struct dm_cell_key key;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001464
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001465 thin_hook_bio(tc, bio);
Joe Thornbere49e5822012-07-27 15:08:16 +01001466
1467 if (get_pool_mode(tc->pool) == PM_FAIL) {
1468 bio_io_error(bio);
1469 return DM_MAPIO_SUBMITTED;
1470 }
1471
Joe Thornber104655f2012-03-28 18:41:28 +01001472 if (bio->bi_rw & (REQ_DISCARD | REQ_FLUSH | REQ_FUA)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001473 thin_defer_bio(tc, bio);
1474 return DM_MAPIO_SUBMITTED;
1475 }
1476
1477 r = dm_thin_find_block(td, block, 0, &result);
1478
1479 /*
1480 * Note that we defer readahead too.
1481 */
1482 switch (r) {
1483 case 0:
1484 if (unlikely(result.shared)) {
1485 /*
1486 * We have a race condition here between the
1487 * result.shared value returned by the lookup and
1488 * snapshot creation, which may cause new
1489 * sharing.
1490 *
1491 * To avoid this always quiesce the origin before
1492 * taking the snap. You want to do this anyway to
1493 * ensure a consistent application view
1494 * (i.e. lockfs).
1495 *
1496 * More distant ancestors are irrelevant. The
1497 * shared flag will be set in their case.
1498 */
1499 thin_defer_bio(tc, bio);
Joe Thornbere8088072012-12-21 20:23:31 +00001500 return DM_MAPIO_SUBMITTED;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001501 }
Joe Thornbere8088072012-12-21 20:23:31 +00001502
1503 build_virtual_key(tc->td, block, &key);
Joe Thornber025b9682013-03-01 22:45:50 +00001504 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell1, &cell_result))
Joe Thornbere8088072012-12-21 20:23:31 +00001505 return DM_MAPIO_SUBMITTED;
1506
1507 build_data_key(tc->td, result.block, &key);
Joe Thornber025b9682013-03-01 22:45:50 +00001508 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell2, &cell_result)) {
1509 cell_defer_no_holder_no_free(tc, &cell1);
Joe Thornbere8088072012-12-21 20:23:31 +00001510 return DM_MAPIO_SUBMITTED;
1511 }
1512
1513 inc_all_io_entry(tc->pool, bio);
Joe Thornber025b9682013-03-01 22:45:50 +00001514 cell_defer_no_holder_no_free(tc, &cell2);
1515 cell_defer_no_holder_no_free(tc, &cell1);
Joe Thornbere8088072012-12-21 20:23:31 +00001516
1517 remap(tc, bio, result.block);
1518 return DM_MAPIO_REMAPPED;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001519
1520 case -ENODATA:
Joe Thornbere49e5822012-07-27 15:08:16 +01001521 if (get_pool_mode(tc->pool) == PM_READ_ONLY) {
1522 /*
1523 * This block isn't provisioned, and we have no way
1524 * of doing so. Just error it.
1525 */
1526 bio_io_error(bio);
Joe Thornber2aab3852012-12-21 20:23:33 +00001527 return DM_MAPIO_SUBMITTED;
Joe Thornbere49e5822012-07-27 15:08:16 +01001528 }
1529 /* fall through */
1530
1531 case -EWOULDBLOCK:
Joe Thornber991d9fa2011-10-31 20:21:18 +00001532 /*
1533 * In future, the failed dm_thin_find_block above could
1534 * provide the hint to load the metadata into cache.
1535 */
Joe Thornber991d9fa2011-10-31 20:21:18 +00001536 thin_defer_bio(tc, bio);
Joe Thornber2aab3852012-12-21 20:23:33 +00001537 return DM_MAPIO_SUBMITTED;
Joe Thornbere49e5822012-07-27 15:08:16 +01001538
1539 default:
1540 /*
1541 * Must always call bio_io_error on failure.
1542 * dm_thin_find_block can fail with -EINVAL if the
1543 * pool is switched to fail-io mode.
1544 */
1545 bio_io_error(bio);
Joe Thornber2aab3852012-12-21 20:23:33 +00001546 return DM_MAPIO_SUBMITTED;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001547 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001548}
1549
1550static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
1551{
1552 int r;
1553 unsigned long flags;
1554 struct pool_c *pt = container_of(cb, struct pool_c, callbacks);
1555
1556 spin_lock_irqsave(&pt->pool->lock, flags);
1557 r = !bio_list_empty(&pt->pool->retry_on_resume_list);
1558 spin_unlock_irqrestore(&pt->pool->lock, flags);
1559
1560 if (!r) {
1561 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
1562 r = bdi_congested(&q->backing_dev_info, bdi_bits);
1563 }
1564
1565 return r;
1566}
1567
1568static void __requeue_bios(struct pool *pool)
1569{
1570 bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list);
1571 bio_list_init(&pool->retry_on_resume_list);
1572}
1573
1574/*----------------------------------------------------------------
1575 * Binding of control targets to a pool object
1576 *--------------------------------------------------------------*/
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001577static bool data_dev_supports_discard(struct pool_c *pt)
1578{
1579 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
1580
1581 return q && blk_queue_discard(q);
1582}
1583
Joe Thornber58051b92013-03-20 17:21:25 +00001584static bool is_factor(sector_t block_size, uint32_t n)
1585{
1586 return !sector_div(block_size, n);
1587}
1588
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001589/*
1590 * If discard_passdown was enabled verify that the data device
Mike Snitzer0424caa2012-09-26 23:45:47 +01001591 * supports discards. Disable discard_passdown if not.
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001592 */
Mike Snitzer0424caa2012-09-26 23:45:47 +01001593static void disable_passdown_if_not_supported(struct pool_c *pt)
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001594{
Mike Snitzer0424caa2012-09-26 23:45:47 +01001595 struct pool *pool = pt->pool;
1596 struct block_device *data_bdev = pt->data_dev->bdev;
1597 struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits;
1598 sector_t block_size = pool->sectors_per_block << SECTOR_SHIFT;
1599 const char *reason = NULL;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001600 char buf[BDEVNAME_SIZE];
1601
Mike Snitzer0424caa2012-09-26 23:45:47 +01001602 if (!pt->adjusted_pf.discard_passdown)
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001603 return;
1604
Mike Snitzer0424caa2012-09-26 23:45:47 +01001605 if (!data_dev_supports_discard(pt))
1606 reason = "discard unsupported";
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001607
Mike Snitzer0424caa2012-09-26 23:45:47 +01001608 else if (data_limits->max_discard_sectors < pool->sectors_per_block)
1609 reason = "max discard sectors smaller than a block";
1610
1611 else if (data_limits->discard_granularity > block_size)
1612 reason = "discard granularity larger than a block";
1613
Joe Thornber58051b92013-03-20 17:21:25 +00001614 else if (!is_factor(block_size, data_limits->discard_granularity))
Mike Snitzer0424caa2012-09-26 23:45:47 +01001615 reason = "discard granularity not a factor of block size";
1616
1617 if (reason) {
1618 DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev, buf), reason);
1619 pt->adjusted_pf.discard_passdown = false;
1620 }
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001621}
1622
Joe Thornber991d9fa2011-10-31 20:21:18 +00001623static int bind_control_target(struct pool *pool, struct dm_target *ti)
1624{
1625 struct pool_c *pt = ti->private;
1626
Joe Thornbere49e5822012-07-27 15:08:16 +01001627 /*
1628 * We want to make sure that degraded pools are never upgraded.
1629 */
1630 enum pool_mode old_mode = pool->pf.mode;
Mike Snitzer0424caa2012-09-26 23:45:47 +01001631 enum pool_mode new_mode = pt->adjusted_pf.mode;
Joe Thornbere49e5822012-07-27 15:08:16 +01001632
1633 if (old_mode > new_mode)
1634 new_mode = old_mode;
1635
Joe Thornber991d9fa2011-10-31 20:21:18 +00001636 pool->ti = ti;
1637 pool->low_water_blocks = pt->low_water_blocks;
Mike Snitzer0424caa2012-09-26 23:45:47 +01001638 pool->pf = pt->adjusted_pf;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001639
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001640 set_pool_mode(pool, new_mode);
Mike Snitzerf4026932012-05-19 01:01:01 +01001641
Joe Thornber991d9fa2011-10-31 20:21:18 +00001642 return 0;
1643}
1644
1645static void unbind_control_target(struct pool *pool, struct dm_target *ti)
1646{
1647 if (pool->ti == ti)
1648 pool->ti = NULL;
1649}
1650
1651/*----------------------------------------------------------------
1652 * Pool creation
1653 *--------------------------------------------------------------*/
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001654/* Initialize pool features. */
1655static void pool_features_init(struct pool_features *pf)
1656{
Joe Thornbere49e5822012-07-27 15:08:16 +01001657 pf->mode = PM_WRITE;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001658 pf->zero_new_blocks = true;
1659 pf->discard_enabled = true;
1660 pf->discard_passdown = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001661}
1662
Joe Thornber991d9fa2011-10-31 20:21:18 +00001663static void __pool_destroy(struct pool *pool)
1664{
1665 __pool_table_remove(pool);
1666
1667 if (dm_pool_metadata_close(pool->pmd) < 0)
1668 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
1669
Mike Snitzer44feb382012-10-12 21:02:10 +01001670 dm_bio_prison_destroy(pool->prison);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001671 dm_kcopyd_client_destroy(pool->copier);
1672
1673 if (pool->wq)
1674 destroy_workqueue(pool->wq);
1675
1676 if (pool->next_mapping)
1677 mempool_free(pool->next_mapping, pool->mapping_pool);
1678 mempool_destroy(pool->mapping_pool);
Mike Snitzer44feb382012-10-12 21:02:10 +01001679 dm_deferred_set_destroy(pool->shared_read_ds);
1680 dm_deferred_set_destroy(pool->all_io_ds);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001681 kfree(pool);
1682}
1683
Mike Snitzera24c2562012-06-03 00:30:00 +01001684static struct kmem_cache *_new_mapping_cache;
Mike Snitzera24c2562012-06-03 00:30:00 +01001685
Joe Thornber991d9fa2011-10-31 20:21:18 +00001686static struct pool *pool_create(struct mapped_device *pool_md,
1687 struct block_device *metadata_dev,
Joe Thornbere49e5822012-07-27 15:08:16 +01001688 unsigned long block_size,
1689 int read_only, char **error)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001690{
1691 int r;
1692 void *err_p;
1693 struct pool *pool;
1694 struct dm_pool_metadata *pmd;
Joe Thornbere49e5822012-07-27 15:08:16 +01001695 bool format_device = read_only ? false : true;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001696
Joe Thornbere49e5822012-07-27 15:08:16 +01001697 pmd = dm_pool_metadata_open(metadata_dev, block_size, format_device);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001698 if (IS_ERR(pmd)) {
1699 *error = "Error creating metadata object";
1700 return (struct pool *)pmd;
1701 }
1702
1703 pool = kmalloc(sizeof(*pool), GFP_KERNEL);
1704 if (!pool) {
1705 *error = "Error allocating memory for pool";
1706 err_p = ERR_PTR(-ENOMEM);
1707 goto bad_pool;
1708 }
1709
1710 pool->pmd = pmd;
1711 pool->sectors_per_block = block_size;
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +01001712 if (block_size & (block_size - 1))
1713 pool->sectors_per_block_shift = -1;
1714 else
1715 pool->sectors_per_block_shift = __ffs(block_size);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001716 pool->low_water_blocks = 0;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001717 pool_features_init(&pool->pf);
Mike Snitzer44feb382012-10-12 21:02:10 +01001718 pool->prison = dm_bio_prison_create(PRISON_CELLS);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001719 if (!pool->prison) {
1720 *error = "Error creating pool's bio prison";
1721 err_p = ERR_PTR(-ENOMEM);
1722 goto bad_prison;
1723 }
1724
Mikulas Patockadf5d2e92013-03-01 22:45:49 +00001725 pool->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001726 if (IS_ERR(pool->copier)) {
1727 r = PTR_ERR(pool->copier);
1728 *error = "Error creating pool's kcopyd client";
1729 err_p = ERR_PTR(r);
1730 goto bad_kcopyd_client;
1731 }
1732
1733 /*
1734 * Create singlethreaded workqueue that will service all devices
1735 * that use this metadata.
1736 */
1737 pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
1738 if (!pool->wq) {
1739 *error = "Error creating pool's workqueue";
1740 err_p = ERR_PTR(-ENOMEM);
1741 goto bad_wq;
1742 }
1743
1744 INIT_WORK(&pool->worker, do_worker);
Joe Thornber905e51b2012-03-28 18:41:27 +01001745 INIT_DELAYED_WORK(&pool->waker, do_waker);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001746 spin_lock_init(&pool->lock);
1747 bio_list_init(&pool->deferred_bios);
1748 bio_list_init(&pool->deferred_flush_bios);
1749 INIT_LIST_HEAD(&pool->prepared_mappings);
Joe Thornber104655f2012-03-28 18:41:28 +01001750 INIT_LIST_HEAD(&pool->prepared_discards);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001751 pool->low_water_triggered = 0;
1752 pool->no_free_space = 0;
1753 bio_list_init(&pool->retry_on_resume_list);
Mike Snitzer44feb382012-10-12 21:02:10 +01001754
1755 pool->shared_read_ds = dm_deferred_set_create();
1756 if (!pool->shared_read_ds) {
1757 *error = "Error creating pool's shared read deferred set";
1758 err_p = ERR_PTR(-ENOMEM);
1759 goto bad_shared_read_ds;
1760 }
1761
1762 pool->all_io_ds = dm_deferred_set_create();
1763 if (!pool->all_io_ds) {
1764 *error = "Error creating pool's all io deferred set";
1765 err_p = ERR_PTR(-ENOMEM);
1766 goto bad_all_io_ds;
1767 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001768
1769 pool->next_mapping = NULL;
Mike Snitzera24c2562012-06-03 00:30:00 +01001770 pool->mapping_pool = mempool_create_slab_pool(MAPPING_POOL_SIZE,
1771 _new_mapping_cache);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001772 if (!pool->mapping_pool) {
1773 *error = "Error creating pool's mapping mempool";
1774 err_p = ERR_PTR(-ENOMEM);
1775 goto bad_mapping_pool;
1776 }
1777
Joe Thornber991d9fa2011-10-31 20:21:18 +00001778 pool->ref_count = 1;
Joe Thornber905e51b2012-03-28 18:41:27 +01001779 pool->last_commit_jiffies = jiffies;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001780 pool->pool_md = pool_md;
1781 pool->md_dev = metadata_dev;
1782 __pool_table_insert(pool);
1783
1784 return pool;
1785
Joe Thornber991d9fa2011-10-31 20:21:18 +00001786bad_mapping_pool:
Mike Snitzer44feb382012-10-12 21:02:10 +01001787 dm_deferred_set_destroy(pool->all_io_ds);
1788bad_all_io_ds:
1789 dm_deferred_set_destroy(pool->shared_read_ds);
1790bad_shared_read_ds:
Joe Thornber991d9fa2011-10-31 20:21:18 +00001791 destroy_workqueue(pool->wq);
1792bad_wq:
1793 dm_kcopyd_client_destroy(pool->copier);
1794bad_kcopyd_client:
Mike Snitzer44feb382012-10-12 21:02:10 +01001795 dm_bio_prison_destroy(pool->prison);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001796bad_prison:
1797 kfree(pool);
1798bad_pool:
1799 if (dm_pool_metadata_close(pmd))
1800 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
1801
1802 return err_p;
1803}
1804
1805static void __pool_inc(struct pool *pool)
1806{
1807 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
1808 pool->ref_count++;
1809}
1810
1811static void __pool_dec(struct pool *pool)
1812{
1813 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
1814 BUG_ON(!pool->ref_count);
1815 if (!--pool->ref_count)
1816 __pool_destroy(pool);
1817}
1818
1819static struct pool *__pool_find(struct mapped_device *pool_md,
1820 struct block_device *metadata_dev,
Joe Thornbere49e5822012-07-27 15:08:16 +01001821 unsigned long block_size, int read_only,
1822 char **error, int *created)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001823{
1824 struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev);
1825
1826 if (pool) {
Mike Snitzerf09996c2012-07-27 15:07:59 +01001827 if (pool->pool_md != pool_md) {
1828 *error = "metadata device already in use by a pool";
Joe Thornber991d9fa2011-10-31 20:21:18 +00001829 return ERR_PTR(-EBUSY);
Mike Snitzerf09996c2012-07-27 15:07:59 +01001830 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001831 __pool_inc(pool);
1832
1833 } else {
1834 pool = __pool_table_lookup(pool_md);
1835 if (pool) {
Mike Snitzerf09996c2012-07-27 15:07:59 +01001836 if (pool->md_dev != metadata_dev) {
1837 *error = "different pool cannot replace a pool";
Joe Thornber991d9fa2011-10-31 20:21:18 +00001838 return ERR_PTR(-EINVAL);
Mike Snitzerf09996c2012-07-27 15:07:59 +01001839 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001840 __pool_inc(pool);
1841
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001842 } else {
Joe Thornbere49e5822012-07-27 15:08:16 +01001843 pool = pool_create(pool_md, metadata_dev, block_size, read_only, error);
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001844 *created = 1;
1845 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001846 }
1847
1848 return pool;
1849}
1850
1851/*----------------------------------------------------------------
1852 * Pool target methods
1853 *--------------------------------------------------------------*/
1854static void pool_dtr(struct dm_target *ti)
1855{
1856 struct pool_c *pt = ti->private;
1857
1858 mutex_lock(&dm_thin_pool_table.mutex);
1859
1860 unbind_control_target(pt->pool, ti);
1861 __pool_dec(pt->pool);
1862 dm_put_device(ti, pt->metadata_dev);
1863 dm_put_device(ti, pt->data_dev);
1864 kfree(pt);
1865
1866 mutex_unlock(&dm_thin_pool_table.mutex);
1867}
1868
Joe Thornber991d9fa2011-10-31 20:21:18 +00001869static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf,
1870 struct dm_target *ti)
1871{
1872 int r;
1873 unsigned argc;
1874 const char *arg_name;
1875
1876 static struct dm_arg _args[] = {
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001877 {0, 3, "Invalid number of pool feature arguments"},
Joe Thornber991d9fa2011-10-31 20:21:18 +00001878 };
1879
1880 /*
1881 * No feature arguments supplied.
1882 */
1883 if (!as->argc)
1884 return 0;
1885
1886 r = dm_read_arg_group(_args, as, &argc, &ti->error);
1887 if (r)
1888 return -EINVAL;
1889
1890 while (argc && !r) {
1891 arg_name = dm_shift_arg(as);
1892 argc--;
1893
Joe Thornbere49e5822012-07-27 15:08:16 +01001894 if (!strcasecmp(arg_name, "skip_block_zeroing"))
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001895 pf->zero_new_blocks = false;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001896
Joe Thornbere49e5822012-07-27 15:08:16 +01001897 else if (!strcasecmp(arg_name, "ignore_discard"))
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001898 pf->discard_enabled = false;
Joe Thornbere49e5822012-07-27 15:08:16 +01001899
1900 else if (!strcasecmp(arg_name, "no_discard_passdown"))
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001901 pf->discard_passdown = false;
Joe Thornbere49e5822012-07-27 15:08:16 +01001902
1903 else if (!strcasecmp(arg_name, "read_only"))
1904 pf->mode = PM_READ_ONLY;
1905
1906 else {
1907 ti->error = "Unrecognised pool feature requested";
1908 r = -EINVAL;
1909 break;
1910 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001911 }
1912
1913 return r;
1914}
1915
Joe Thornberac8c3f32013-05-10 14:37:21 +01001916static void metadata_low_callback(void *context)
1917{
1918 struct pool *pool = context;
1919
1920 DMWARN("%s: reached low water mark for metadata device: sending event.",
1921 dm_device_name(pool->pool_md));
1922
1923 dm_table_event(pool->ti->table);
1924}
1925
Joe Thornberb17446d2013-05-10 14:37:18 +01001926static sector_t get_metadata_dev_size(struct block_device *bdev)
1927{
1928 sector_t metadata_dev_size = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
1929 char buffer[BDEVNAME_SIZE];
1930
1931 if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING) {
1932 DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",
1933 bdevname(bdev, buffer), THIN_METADATA_MAX_SECTORS);
1934 metadata_dev_size = THIN_METADATA_MAX_SECTORS_WARNING;
1935 }
1936
1937 return metadata_dev_size;
1938}
1939
Joe Thornber24347e92013-05-10 14:37:19 +01001940static dm_block_t get_metadata_dev_size_in_blocks(struct block_device *bdev)
1941{
1942 sector_t metadata_dev_size = get_metadata_dev_size(bdev);
1943
1944 sector_div(metadata_dev_size, THIN_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
1945
1946 return metadata_dev_size;
1947}
1948
Joe Thornber991d9fa2011-10-31 20:21:18 +00001949/*
Joe Thornberac8c3f32013-05-10 14:37:21 +01001950 * When a metadata threshold is crossed a dm event is triggered, and
1951 * userland should respond by growing the metadata device. We could let
1952 * userland set the threshold, like we do with the data threshold, but I'm
1953 * not sure they know enough to do this well.
1954 */
1955static dm_block_t calc_metadata_threshold(struct pool_c *pt)
1956{
1957 /*
1958 * 4M is ample for all ops with the possible exception of thin
1959 * device deletion which is harmless if it fails (just retry the
1960 * delete after you've grown the device).
1961 */
1962 dm_block_t quarter = get_metadata_dev_size_in_blocks(pt->metadata_dev->bdev) / 4;
1963 return min((dm_block_t)1024ULL /* 4M */, quarter);
1964}
1965
1966/*
Joe Thornber991d9fa2011-10-31 20:21:18 +00001967 * thin-pool <metadata dev> <data dev>
1968 * <data block size (sectors)>
1969 * <low water mark (blocks)>
1970 * [<#feature args> [<arg>]*]
1971 *
1972 * Optional feature arguments are:
1973 * skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001974 * ignore_discard: disable discard
1975 * no_discard_passdown: don't pass discards down to the data device
Joe Thornber991d9fa2011-10-31 20:21:18 +00001976 */
1977static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv)
1978{
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001979 int r, pool_created = 0;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001980 struct pool_c *pt;
1981 struct pool *pool;
1982 struct pool_features pf;
1983 struct dm_arg_set as;
1984 struct dm_dev *data_dev;
1985 unsigned long block_size;
1986 dm_block_t low_water_blocks;
1987 struct dm_dev *metadata_dev;
Joe Thornber5d0db962013-05-10 14:37:19 +01001988 fmode_t metadata_mode;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001989
1990 /*
1991 * FIXME Remove validation from scope of lock.
1992 */
1993 mutex_lock(&dm_thin_pool_table.mutex);
1994
1995 if (argc < 4) {
1996 ti->error = "Invalid argument count";
1997 r = -EINVAL;
1998 goto out_unlock;
1999 }
Joe Thornber5d0db962013-05-10 14:37:19 +01002000
Joe Thornber991d9fa2011-10-31 20:21:18 +00002001 as.argc = argc;
2002 as.argv = argv;
2003
Joe Thornber5d0db962013-05-10 14:37:19 +01002004 /*
2005 * Set default pool features.
2006 */
2007 pool_features_init(&pf);
2008
2009 dm_consume_args(&as, 4);
2010 r = parse_pool_features(&as, &pf, ti);
2011 if (r)
2012 goto out_unlock;
2013
2014 metadata_mode = FMODE_READ | ((pf.mode == PM_READ_ONLY) ? 0 : FMODE_WRITE);
2015 r = dm_get_device(ti, argv[0], metadata_mode, &metadata_dev);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002016 if (r) {
2017 ti->error = "Error opening metadata block device";
2018 goto out_unlock;
2019 }
2020
Joe Thornberb17446d2013-05-10 14:37:18 +01002021 /*
2022 * Run for the side-effect of possibly issuing a warning if the
2023 * device is too big.
2024 */
2025 (void) get_metadata_dev_size(metadata_dev->bdev);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002026
2027 r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev);
2028 if (r) {
2029 ti->error = "Error getting data device";
2030 goto out_metadata;
2031 }
2032
2033 if (kstrtoul(argv[2], 10, &block_size) || !block_size ||
2034 block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
2035 block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002036 block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00002037 ti->error = "Invalid block size";
2038 r = -EINVAL;
2039 goto out;
2040 }
2041
2042 if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) {
2043 ti->error = "Invalid low water mark";
2044 r = -EINVAL;
2045 goto out;
2046 }
2047
Joe Thornber991d9fa2011-10-31 20:21:18 +00002048 pt = kzalloc(sizeof(*pt), GFP_KERNEL);
2049 if (!pt) {
2050 r = -ENOMEM;
2051 goto out;
2052 }
2053
2054 pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev,
Joe Thornbere49e5822012-07-27 15:08:16 +01002055 block_size, pf.mode == PM_READ_ONLY, &ti->error, &pool_created);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002056 if (IS_ERR(pool)) {
2057 r = PTR_ERR(pool);
2058 goto out_free_pt;
2059 }
2060
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002061 /*
2062 * 'pool_created' reflects whether this is the first table load.
2063 * Top level discard support is not allowed to be changed after
2064 * initial load. This would require a pool reload to trigger thin
2065 * device changes.
2066 */
2067 if (!pool_created && pf.discard_enabled != pool->pf.discard_enabled) {
2068 ti->error = "Discard support cannot be disabled once enabled";
2069 r = -EINVAL;
2070 goto out_flags_changed;
2071 }
2072
Joe Thornber991d9fa2011-10-31 20:21:18 +00002073 pt->pool = pool;
2074 pt->ti = ti;
2075 pt->metadata_dev = metadata_dev;
2076 pt->data_dev = data_dev;
2077 pt->low_water_blocks = low_water_blocks;
Mike Snitzer0424caa2012-09-26 23:45:47 +01002078 pt->adjusted_pf = pt->requested_pf = pf;
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00002079 ti->num_flush_bios = 1;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01002080
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002081 /*
2082 * Only need to enable discards if the pool should pass
2083 * them down to the data device. The thin device's discard
2084 * processing will cause mappings to be removed from the btree.
2085 */
2086 if (pf.discard_enabled && pf.discard_passdown) {
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00002087 ti->num_discard_bios = 1;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01002088
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002089 /*
2090 * Setting 'discards_supported' circumvents the normal
2091 * stacking of discard limits (this keeps the pool and
2092 * thin devices' discard limits consistent).
2093 */
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01002094 ti->discards_supported = true;
Mike Snitzer307615a2012-09-26 23:45:39 +01002095 ti->discard_zeroes_data_unsupported = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002096 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002097 ti->private = pt;
2098
Joe Thornberac8c3f32013-05-10 14:37:21 +01002099 r = dm_pool_register_metadata_threshold(pt->pool->pmd,
2100 calc_metadata_threshold(pt),
2101 metadata_low_callback,
2102 pool);
2103 if (r)
2104 goto out_free_pt;
2105
Joe Thornber991d9fa2011-10-31 20:21:18 +00002106 pt->callbacks.congested_fn = pool_is_congested;
2107 dm_table_add_target_callbacks(ti->table, &pt->callbacks);
2108
2109 mutex_unlock(&dm_thin_pool_table.mutex);
2110
2111 return 0;
2112
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002113out_flags_changed:
2114 __pool_dec(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002115out_free_pt:
2116 kfree(pt);
2117out:
2118 dm_put_device(ti, data_dev);
2119out_metadata:
2120 dm_put_device(ti, metadata_dev);
2121out_unlock:
2122 mutex_unlock(&dm_thin_pool_table.mutex);
2123
2124 return r;
2125}
2126
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00002127static int pool_map(struct dm_target *ti, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002128{
2129 int r;
2130 struct pool_c *pt = ti->private;
2131 struct pool *pool = pt->pool;
2132 unsigned long flags;
2133
2134 /*
2135 * As this is a singleton target, ti->begin is always zero.
2136 */
2137 spin_lock_irqsave(&pool->lock, flags);
2138 bio->bi_bdev = pt->data_dev->bdev;
2139 r = DM_MAPIO_REMAPPED;
2140 spin_unlock_irqrestore(&pool->lock, flags);
2141
2142 return r;
2143}
2144
Joe Thornberb17446d2013-05-10 14:37:18 +01002145static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit)
2146{
2147 int r;
2148 struct pool_c *pt = ti->private;
2149 struct pool *pool = pt->pool;
2150 sector_t data_size = ti->len;
2151 dm_block_t sb_data_size;
2152
2153 *need_commit = false;
2154
2155 (void) sector_div(data_size, pool->sectors_per_block);
2156
2157 r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
2158 if (r) {
2159 DMERR("failed to retrieve data device size");
2160 return r;
2161 }
2162
2163 if (data_size < sb_data_size) {
2164 DMERR("pool target (%llu blocks) too small: expected %llu",
2165 (unsigned long long)data_size, sb_data_size);
2166 return -EINVAL;
2167
2168 } else if (data_size > sb_data_size) {
2169 r = dm_pool_resize_data_dev(pool->pmd, data_size);
2170 if (r) {
2171 DMERR("failed to resize data device");
2172 set_pool_mode(pool, PM_READ_ONLY);
2173 return r;
2174 }
2175
2176 *need_commit = true;
2177 }
2178
2179 return 0;
2180}
2181
Joe Thornber24347e92013-05-10 14:37:19 +01002182static int maybe_resize_metadata_dev(struct dm_target *ti, bool *need_commit)
2183{
2184 int r;
2185 struct pool_c *pt = ti->private;
2186 struct pool *pool = pt->pool;
2187 dm_block_t metadata_dev_size, sb_metadata_dev_size;
2188
2189 *need_commit = false;
2190
2191 metadata_dev_size = get_metadata_dev_size(pool->md_dev);
2192
2193 r = dm_pool_get_metadata_dev_size(pool->pmd, &sb_metadata_dev_size);
2194 if (r) {
2195 DMERR("failed to retrieve data device size");
2196 return r;
2197 }
2198
2199 if (metadata_dev_size < sb_metadata_dev_size) {
2200 DMERR("metadata device (%llu sectors) too small: expected %llu",
2201 metadata_dev_size, sb_metadata_dev_size);
2202 return -EINVAL;
2203
2204 } else if (metadata_dev_size > sb_metadata_dev_size) {
2205 r = dm_pool_resize_metadata_dev(pool->pmd, metadata_dev_size);
2206 if (r) {
2207 DMERR("failed to resize metadata device");
2208 return r;
2209 }
2210
2211 *need_commit = true;
2212 }
2213
2214 return 0;
2215}
2216
Joe Thornber991d9fa2011-10-31 20:21:18 +00002217/*
2218 * Retrieves the number of blocks of the data device from
2219 * the superblock and compares it to the actual device size,
2220 * thus resizing the data device in case it has grown.
2221 *
2222 * This both copes with opening preallocated data devices in the ctr
2223 * being followed by a resume
2224 * -and-
2225 * calling the resume method individually after userspace has
2226 * grown the data device in reaction to a table event.
2227 */
2228static int pool_preresume(struct dm_target *ti)
2229{
2230 int r;
Joe Thornber24347e92013-05-10 14:37:19 +01002231 bool need_commit1, need_commit2;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002232 struct pool_c *pt = ti->private;
2233 struct pool *pool = pt->pool;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002234
2235 /*
2236 * Take control of the pool object.
2237 */
2238 r = bind_control_target(pool, ti);
2239 if (r)
2240 return r;
2241
Joe Thornberb17446d2013-05-10 14:37:18 +01002242 r = maybe_resize_data_dev(ti, &need_commit1);
2243 if (r)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002244 return r;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002245
Joe Thornber24347e92013-05-10 14:37:19 +01002246 r = maybe_resize_metadata_dev(ti, &need_commit2);
2247 if (r)
2248 return r;
2249
2250 if (need_commit1 || need_commit2)
Joe Thornbere49e5822012-07-27 15:08:16 +01002251 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002252
2253 return 0;
2254}
2255
2256static void pool_resume(struct dm_target *ti)
2257{
2258 struct pool_c *pt = ti->private;
2259 struct pool *pool = pt->pool;
2260 unsigned long flags;
2261
2262 spin_lock_irqsave(&pool->lock, flags);
2263 pool->low_water_triggered = 0;
2264 pool->no_free_space = 0;
2265 __requeue_bios(pool);
2266 spin_unlock_irqrestore(&pool->lock, flags);
2267
Joe Thornber905e51b2012-03-28 18:41:27 +01002268 do_waker(&pool->waker.work);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002269}
2270
2271static void pool_postsuspend(struct dm_target *ti)
2272{
Joe Thornber991d9fa2011-10-31 20:21:18 +00002273 struct pool_c *pt = ti->private;
2274 struct pool *pool = pt->pool;
2275
Joe Thornber905e51b2012-03-28 18:41:27 +01002276 cancel_delayed_work(&pool->waker);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002277 flush_workqueue(pool->wq);
Joe Thornbere49e5822012-07-27 15:08:16 +01002278 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002279}
2280
2281static int check_arg_count(unsigned argc, unsigned args_required)
2282{
2283 if (argc != args_required) {
2284 DMWARN("Message received with %u arguments instead of %u.",
2285 argc, args_required);
2286 return -EINVAL;
2287 }
2288
2289 return 0;
2290}
2291
2292static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning)
2293{
2294 if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) &&
2295 *dev_id <= MAX_DEV_ID)
2296 return 0;
2297
2298 if (warning)
2299 DMWARN("Message received with invalid device id: %s", arg);
2300
2301 return -EINVAL;
2302}
2303
2304static int process_create_thin_mesg(unsigned argc, char **argv, struct pool *pool)
2305{
2306 dm_thin_id dev_id;
2307 int r;
2308
2309 r = check_arg_count(argc, 2);
2310 if (r)
2311 return r;
2312
2313 r = read_dev_id(argv[1], &dev_id, 1);
2314 if (r)
2315 return r;
2316
2317 r = dm_pool_create_thin(pool->pmd, dev_id);
2318 if (r) {
2319 DMWARN("Creation of new thinly-provisioned device with id %s failed.",
2320 argv[1]);
2321 return r;
2322 }
2323
2324 return 0;
2325}
2326
2327static int process_create_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2328{
2329 dm_thin_id dev_id;
2330 dm_thin_id origin_dev_id;
2331 int r;
2332
2333 r = check_arg_count(argc, 3);
2334 if (r)
2335 return r;
2336
2337 r = read_dev_id(argv[1], &dev_id, 1);
2338 if (r)
2339 return r;
2340
2341 r = read_dev_id(argv[2], &origin_dev_id, 1);
2342 if (r)
2343 return r;
2344
2345 r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id);
2346 if (r) {
2347 DMWARN("Creation of new snapshot %s of device %s failed.",
2348 argv[1], argv[2]);
2349 return r;
2350 }
2351
2352 return 0;
2353}
2354
2355static int process_delete_mesg(unsigned argc, char **argv, struct pool *pool)
2356{
2357 dm_thin_id dev_id;
2358 int r;
2359
2360 r = check_arg_count(argc, 2);
2361 if (r)
2362 return r;
2363
2364 r = read_dev_id(argv[1], &dev_id, 1);
2365 if (r)
2366 return r;
2367
2368 r = dm_pool_delete_thin_device(pool->pmd, dev_id);
2369 if (r)
2370 DMWARN("Deletion of thin device %s failed.", argv[1]);
2371
2372 return r;
2373}
2374
2375static int process_set_transaction_id_mesg(unsigned argc, char **argv, struct pool *pool)
2376{
2377 dm_thin_id old_id, new_id;
2378 int r;
2379
2380 r = check_arg_count(argc, 3);
2381 if (r)
2382 return r;
2383
2384 if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) {
2385 DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]);
2386 return -EINVAL;
2387 }
2388
2389 if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) {
2390 DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]);
2391 return -EINVAL;
2392 }
2393
2394 r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id);
2395 if (r) {
2396 DMWARN("Failed to change transaction id from %s to %s.",
2397 argv[1], argv[2]);
2398 return r;
2399 }
2400
2401 return 0;
2402}
2403
Joe Thornbercc8394d2012-06-03 00:30:01 +01002404static int process_reserve_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2405{
2406 int r;
2407
2408 r = check_arg_count(argc, 1);
2409 if (r)
2410 return r;
2411
Joe Thornbere49e5822012-07-27 15:08:16 +01002412 (void) commit_or_fallback(pool);
Joe Thornber0d200ae2012-07-03 12:55:31 +01002413
Joe Thornbercc8394d2012-06-03 00:30:01 +01002414 r = dm_pool_reserve_metadata_snap(pool->pmd);
2415 if (r)
2416 DMWARN("reserve_metadata_snap message failed.");
2417
2418 return r;
2419}
2420
2421static int process_release_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2422{
2423 int r;
2424
2425 r = check_arg_count(argc, 1);
2426 if (r)
2427 return r;
2428
2429 r = dm_pool_release_metadata_snap(pool->pmd);
2430 if (r)
2431 DMWARN("release_metadata_snap message failed.");
2432
2433 return r;
2434}
2435
Joe Thornber991d9fa2011-10-31 20:21:18 +00002436/*
2437 * Messages supported:
2438 * create_thin <dev_id>
2439 * create_snap <dev_id> <origin_id>
2440 * delete <dev_id>
2441 * trim <dev_id> <new_size_in_sectors>
2442 * set_transaction_id <current_trans_id> <new_trans_id>
Joe Thornbercc8394d2012-06-03 00:30:01 +01002443 * reserve_metadata_snap
2444 * release_metadata_snap
Joe Thornber991d9fa2011-10-31 20:21:18 +00002445 */
2446static int pool_message(struct dm_target *ti, unsigned argc, char **argv)
2447{
2448 int r = -EINVAL;
2449 struct pool_c *pt = ti->private;
2450 struct pool *pool = pt->pool;
2451
2452 if (!strcasecmp(argv[0], "create_thin"))
2453 r = process_create_thin_mesg(argc, argv, pool);
2454
2455 else if (!strcasecmp(argv[0], "create_snap"))
2456 r = process_create_snap_mesg(argc, argv, pool);
2457
2458 else if (!strcasecmp(argv[0], "delete"))
2459 r = process_delete_mesg(argc, argv, pool);
2460
2461 else if (!strcasecmp(argv[0], "set_transaction_id"))
2462 r = process_set_transaction_id_mesg(argc, argv, pool);
2463
Joe Thornbercc8394d2012-06-03 00:30:01 +01002464 else if (!strcasecmp(argv[0], "reserve_metadata_snap"))
2465 r = process_reserve_metadata_snap_mesg(argc, argv, pool);
2466
2467 else if (!strcasecmp(argv[0], "release_metadata_snap"))
2468 r = process_release_metadata_snap_mesg(argc, argv, pool);
2469
Joe Thornber991d9fa2011-10-31 20:21:18 +00002470 else
2471 DMWARN("Unrecognised thin pool target message received: %s", argv[0]);
2472
Joe Thornbere49e5822012-07-27 15:08:16 +01002473 if (!r)
2474 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002475
2476 return r;
2477}
2478
Joe Thornbere49e5822012-07-27 15:08:16 +01002479static void emit_flags(struct pool_features *pf, char *result,
2480 unsigned sz, unsigned maxlen)
2481{
2482 unsigned count = !pf->zero_new_blocks + !pf->discard_enabled +
2483 !pf->discard_passdown + (pf->mode == PM_READ_ONLY);
2484 DMEMIT("%u ", count);
2485
2486 if (!pf->zero_new_blocks)
2487 DMEMIT("skip_block_zeroing ");
2488
2489 if (!pf->discard_enabled)
2490 DMEMIT("ignore_discard ");
2491
2492 if (!pf->discard_passdown)
2493 DMEMIT("no_discard_passdown ");
2494
2495 if (pf->mode == PM_READ_ONLY)
2496 DMEMIT("read_only ");
2497}
2498
Joe Thornber991d9fa2011-10-31 20:21:18 +00002499/*
2500 * Status line is:
2501 * <transaction id> <used metadata sectors>/<total metadata sectors>
2502 * <used data sectors>/<total data sectors> <held metadata root>
2503 */
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002504static void pool_status(struct dm_target *ti, status_type_t type,
2505 unsigned status_flags, char *result, unsigned maxlen)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002506{
Joe Thornbere49e5822012-07-27 15:08:16 +01002507 int r;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002508 unsigned sz = 0;
2509 uint64_t transaction_id;
2510 dm_block_t nr_free_blocks_data;
2511 dm_block_t nr_free_blocks_metadata;
2512 dm_block_t nr_blocks_data;
2513 dm_block_t nr_blocks_metadata;
2514 dm_block_t held_root;
2515 char buf[BDEVNAME_SIZE];
2516 char buf2[BDEVNAME_SIZE];
2517 struct pool_c *pt = ti->private;
2518 struct pool *pool = pt->pool;
2519
2520 switch (type) {
2521 case STATUSTYPE_INFO:
Joe Thornbere49e5822012-07-27 15:08:16 +01002522 if (get_pool_mode(pool) == PM_FAIL) {
2523 DMEMIT("Fail");
2524 break;
2525 }
2526
Alasdair G Kergon1f4e0ff2012-07-27 15:08:16 +01002527 /* Commit to ensure statistics aren't out-of-date */
2528 if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
2529 (void) commit_or_fallback(pool);
2530
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002531 r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id);
2532 if (r) {
2533 DMERR("dm_pool_get_metadata_transaction_id returned %d", r);
2534 goto err;
2535 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002536
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002537 r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free_blocks_metadata);
2538 if (r) {
2539 DMERR("dm_pool_get_free_metadata_block_count returned %d", r);
2540 goto err;
2541 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002542
2543 r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002544 if (r) {
2545 DMERR("dm_pool_get_metadata_dev_size returned %d", r);
2546 goto err;
2547 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002548
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002549 r = dm_pool_get_free_block_count(pool->pmd, &nr_free_blocks_data);
2550 if (r) {
2551 DMERR("dm_pool_get_free_block_count returned %d", r);
2552 goto err;
2553 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002554
2555 r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002556 if (r) {
2557 DMERR("dm_pool_get_data_dev_size returned %d", r);
2558 goto err;
2559 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002560
Joe Thornbercc8394d2012-06-03 00:30:01 +01002561 r = dm_pool_get_metadata_snap(pool->pmd, &held_root);
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002562 if (r) {
2563 DMERR("dm_pool_get_metadata_snap returned %d", r);
2564 goto err;
2565 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002566
2567 DMEMIT("%llu %llu/%llu %llu/%llu ",
2568 (unsigned long long)transaction_id,
2569 (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata),
2570 (unsigned long long)nr_blocks_metadata,
2571 (unsigned long long)(nr_blocks_data - nr_free_blocks_data),
2572 (unsigned long long)nr_blocks_data);
2573
2574 if (held_root)
Joe Thornbere49e5822012-07-27 15:08:16 +01002575 DMEMIT("%llu ", held_root);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002576 else
Joe Thornbere49e5822012-07-27 15:08:16 +01002577 DMEMIT("- ");
2578
2579 if (pool->pf.mode == PM_READ_ONLY)
2580 DMEMIT("ro ");
2581 else
2582 DMEMIT("rw ");
2583
Mike Snitzer018debe2012-12-21 20:23:32 +00002584 if (!pool->pf.discard_enabled)
2585 DMEMIT("ignore_discard");
2586 else if (pool->pf.discard_passdown)
Joe Thornbere49e5822012-07-27 15:08:16 +01002587 DMEMIT("discard_passdown");
2588 else
2589 DMEMIT("no_discard_passdown");
Joe Thornber991d9fa2011-10-31 20:21:18 +00002590
2591 break;
2592
2593 case STATUSTYPE_TABLE:
2594 DMEMIT("%s %s %lu %llu ",
2595 format_dev_t(buf, pt->metadata_dev->bdev->bd_dev),
2596 format_dev_t(buf2, pt->data_dev->bdev->bd_dev),
2597 (unsigned long)pool->sectors_per_block,
2598 (unsigned long long)pt->low_water_blocks);
Mike Snitzer0424caa2012-09-26 23:45:47 +01002599 emit_flags(&pt->requested_pf, result, sz, maxlen);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002600 break;
2601 }
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002602 return;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002603
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002604err:
2605 DMEMIT("Error");
Joe Thornber991d9fa2011-10-31 20:21:18 +00002606}
2607
2608static int pool_iterate_devices(struct dm_target *ti,
2609 iterate_devices_callout_fn fn, void *data)
2610{
2611 struct pool_c *pt = ti->private;
2612
2613 return fn(ti, pt->data_dev, 0, ti->len, data);
2614}
2615
2616static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
2617 struct bio_vec *biovec, int max_size)
2618{
2619 struct pool_c *pt = ti->private;
2620 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
2621
2622 if (!q->merge_bvec_fn)
2623 return max_size;
2624
2625 bvm->bi_bdev = pt->data_dev->bdev;
2626
2627 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
2628}
2629
Mike Snitzer0424caa2012-09-26 23:45:47 +01002630static void set_discard_limits(struct pool_c *pt, struct queue_limits *limits)
Joe Thornber104655f2012-03-28 18:41:28 +01002631{
Mike Snitzer0424caa2012-09-26 23:45:47 +01002632 struct pool *pool = pt->pool;
2633 struct queue_limits *data_limits;
2634
Joe Thornber104655f2012-03-28 18:41:28 +01002635 limits->max_discard_sectors = pool->sectors_per_block;
2636
2637 /*
Mike Snitzer0424caa2012-09-26 23:45:47 +01002638 * discard_granularity is just a hint, and not enforced.
Joe Thornber104655f2012-03-28 18:41:28 +01002639 */
Mike Snitzer0424caa2012-09-26 23:45:47 +01002640 if (pt->adjusted_pf.discard_passdown) {
2641 data_limits = &bdev_get_queue(pt->data_dev->bdev)->limits;
2642 limits->discard_granularity = data_limits->discard_granularity;
Mike Snitzerf13945d2013-03-01 22:45:44 +00002643 } else
Mike Snitzer0424caa2012-09-26 23:45:47 +01002644 limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
Joe Thornber104655f2012-03-28 18:41:28 +01002645}
2646
Joe Thornber991d9fa2011-10-31 20:21:18 +00002647static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
2648{
2649 struct pool_c *pt = ti->private;
2650 struct pool *pool = pt->pool;
2651
2652 blk_limits_io_min(limits, 0);
2653 blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
Mike Snitzer0424caa2012-09-26 23:45:47 +01002654
2655 /*
2656 * pt->adjusted_pf is a staging area for the actual features to use.
2657 * They get transferred to the live pool in bind_control_target()
2658 * called from pool_preresume().
2659 */
2660 if (!pt->adjusted_pf.discard_enabled)
2661 return;
2662
2663 disable_passdown_if_not_supported(pt);
2664
2665 set_discard_limits(pt, limits);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002666}
2667
2668static struct target_type pool_target = {
2669 .name = "thin-pool",
2670 .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
2671 DM_TARGET_IMMUTABLE,
Joe Thornber24347e92013-05-10 14:37:19 +01002672 .version = {1, 8, 0},
Joe Thornber991d9fa2011-10-31 20:21:18 +00002673 .module = THIS_MODULE,
2674 .ctr = pool_ctr,
2675 .dtr = pool_dtr,
2676 .map = pool_map,
2677 .postsuspend = pool_postsuspend,
2678 .preresume = pool_preresume,
2679 .resume = pool_resume,
2680 .message = pool_message,
2681 .status = pool_status,
2682 .merge = pool_merge,
2683 .iterate_devices = pool_iterate_devices,
2684 .io_hints = pool_io_hints,
2685};
2686
2687/*----------------------------------------------------------------
2688 * Thin target methods
2689 *--------------------------------------------------------------*/
2690static void thin_dtr(struct dm_target *ti)
2691{
2692 struct thin_c *tc = ti->private;
2693
2694 mutex_lock(&dm_thin_pool_table.mutex);
2695
2696 __pool_dec(tc->pool);
2697 dm_pool_close_thin_device(tc->td);
2698 dm_put_device(ti, tc->pool_dev);
Joe Thornber2dd9c252012-03-28 18:41:28 +01002699 if (tc->origin_dev)
2700 dm_put_device(ti, tc->origin_dev);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002701 kfree(tc);
2702
2703 mutex_unlock(&dm_thin_pool_table.mutex);
2704}
2705
2706/*
2707 * Thin target parameters:
2708 *
Joe Thornber2dd9c252012-03-28 18:41:28 +01002709 * <pool_dev> <dev_id> [origin_dev]
Joe Thornber991d9fa2011-10-31 20:21:18 +00002710 *
2711 * pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
2712 * dev_id: the internal device identifier
Joe Thornber2dd9c252012-03-28 18:41:28 +01002713 * origin_dev: a device external to the pool that should act as the origin
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002714 *
2715 * If the pool device has discards disabled, they get disabled for the thin
2716 * device as well.
Joe Thornber991d9fa2011-10-31 20:21:18 +00002717 */
2718static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
2719{
2720 int r;
2721 struct thin_c *tc;
Joe Thornber2dd9c252012-03-28 18:41:28 +01002722 struct dm_dev *pool_dev, *origin_dev;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002723 struct mapped_device *pool_md;
2724
2725 mutex_lock(&dm_thin_pool_table.mutex);
2726
Joe Thornber2dd9c252012-03-28 18:41:28 +01002727 if (argc != 2 && argc != 3) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00002728 ti->error = "Invalid argument count";
2729 r = -EINVAL;
2730 goto out_unlock;
2731 }
2732
2733 tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL);
2734 if (!tc) {
2735 ti->error = "Out of memory";
2736 r = -ENOMEM;
2737 goto out_unlock;
2738 }
2739
Joe Thornber2dd9c252012-03-28 18:41:28 +01002740 if (argc == 3) {
2741 r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev);
2742 if (r) {
2743 ti->error = "Error opening origin device";
2744 goto bad_origin_dev;
2745 }
2746 tc->origin_dev = origin_dev;
2747 }
2748
Joe Thornber991d9fa2011-10-31 20:21:18 +00002749 r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev);
2750 if (r) {
2751 ti->error = "Error opening pool device";
2752 goto bad_pool_dev;
2753 }
2754 tc->pool_dev = pool_dev;
2755
2756 if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) {
2757 ti->error = "Invalid device id";
2758 r = -EINVAL;
2759 goto bad_common;
2760 }
2761
2762 pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev);
2763 if (!pool_md) {
2764 ti->error = "Couldn't get pool mapped device";
2765 r = -EINVAL;
2766 goto bad_common;
2767 }
2768
2769 tc->pool = __pool_table_lookup(pool_md);
2770 if (!tc->pool) {
2771 ti->error = "Couldn't find pool object";
2772 r = -EINVAL;
2773 goto bad_pool_lookup;
2774 }
2775 __pool_inc(tc->pool);
2776
Joe Thornbere49e5822012-07-27 15:08:16 +01002777 if (get_pool_mode(tc->pool) == PM_FAIL) {
2778 ti->error = "Couldn't open thin device, Pool is in fail mode";
2779 goto bad_thin_open;
2780 }
2781
Joe Thornber991d9fa2011-10-31 20:21:18 +00002782 r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td);
2783 if (r) {
2784 ti->error = "Couldn't open thin internal device";
2785 goto bad_thin_open;
2786 }
2787
Mike Snitzer542f9032012-07-27 15:08:00 +01002788 r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
2789 if (r)
2790 goto bad_thin_open;
2791
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00002792 ti->num_flush_bios = 1;
Joe Thornber16ad3d12012-07-27 15:08:07 +01002793 ti->flush_supported = true;
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00002794 ti->per_bio_data_size = sizeof(struct dm_thin_endio_hook);
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002795
2796 /* In case the pool supports discards, pass them on. */
2797 if (tc->pool->pf.discard_enabled) {
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01002798 ti->discards_supported = true;
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00002799 ti->num_discard_bios = 1;
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01002800 ti->discard_zeroes_data_unsupported = true;
Alasdair G Kergon55a62ee2013-03-01 22:45:47 +00002801 /* Discard bios must be split on a block boundary */
2802 ti->split_discard_bios = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002803 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002804
2805 dm_put(pool_md);
2806
2807 mutex_unlock(&dm_thin_pool_table.mutex);
2808
2809 return 0;
2810
2811bad_thin_open:
2812 __pool_dec(tc->pool);
2813bad_pool_lookup:
2814 dm_put(pool_md);
2815bad_common:
2816 dm_put_device(ti, tc->pool_dev);
2817bad_pool_dev:
Joe Thornber2dd9c252012-03-28 18:41:28 +01002818 if (tc->origin_dev)
2819 dm_put_device(ti, tc->origin_dev);
2820bad_origin_dev:
Joe Thornber991d9fa2011-10-31 20:21:18 +00002821 kfree(tc);
2822out_unlock:
2823 mutex_unlock(&dm_thin_pool_table.mutex);
2824
2825 return r;
2826}
2827
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00002828static int thin_map(struct dm_target *ti, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002829{
Alasdair G Kergon6efd6e82012-03-28 18:41:28 +01002830 bio->bi_sector = dm_target_offset(ti, bio->bi_sector);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002831
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00002832 return thin_bio_map(ti, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002833}
2834
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00002835static int thin_endio(struct dm_target *ti, struct bio *bio, int err)
Joe Thornbereb2aa482012-03-28 18:41:28 +01002836{
2837 unsigned long flags;
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00002838 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbereb2aa482012-03-28 18:41:28 +01002839 struct list_head work;
Mike Snitzera24c2562012-06-03 00:30:00 +01002840 struct dm_thin_new_mapping *m, *tmp;
Joe Thornbereb2aa482012-03-28 18:41:28 +01002841 struct pool *pool = h->tc->pool;
2842
2843 if (h->shared_read_entry) {
2844 INIT_LIST_HEAD(&work);
Mike Snitzer44feb382012-10-12 21:02:10 +01002845 dm_deferred_entry_dec(h->shared_read_entry, &work);
Joe Thornbereb2aa482012-03-28 18:41:28 +01002846
2847 spin_lock_irqsave(&pool->lock, flags);
2848 list_for_each_entry_safe(m, tmp, &work, list) {
2849 list_del(&m->list);
2850 m->quiesced = 1;
2851 __maybe_add_mapping(m);
2852 }
2853 spin_unlock_irqrestore(&pool->lock, flags);
2854 }
2855
Joe Thornber104655f2012-03-28 18:41:28 +01002856 if (h->all_io_entry) {
2857 INIT_LIST_HEAD(&work);
Mike Snitzer44feb382012-10-12 21:02:10 +01002858 dm_deferred_entry_dec(h->all_io_entry, &work);
Joe Thornber563af182012-12-21 20:23:31 +00002859 if (!list_empty(&work)) {
2860 spin_lock_irqsave(&pool->lock, flags);
2861 list_for_each_entry_safe(m, tmp, &work, list)
2862 list_add(&m->list, &pool->prepared_discards);
2863 spin_unlock_irqrestore(&pool->lock, flags);
2864 wake_worker(pool);
2865 }
Joe Thornber104655f2012-03-28 18:41:28 +01002866 }
2867
Joe Thornbereb2aa482012-03-28 18:41:28 +01002868 return 0;
2869}
2870
Joe Thornber991d9fa2011-10-31 20:21:18 +00002871static void thin_postsuspend(struct dm_target *ti)
2872{
2873 if (dm_noflush_suspending(ti))
2874 requeue_io((struct thin_c *)ti->private);
2875}
2876
2877/*
2878 * <nr mapped sectors> <highest mapped sector>
2879 */
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002880static void thin_status(struct dm_target *ti, status_type_t type,
2881 unsigned status_flags, char *result, unsigned maxlen)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002882{
2883 int r;
2884 ssize_t sz = 0;
2885 dm_block_t mapped, highest;
2886 char buf[BDEVNAME_SIZE];
2887 struct thin_c *tc = ti->private;
2888
Joe Thornbere49e5822012-07-27 15:08:16 +01002889 if (get_pool_mode(tc->pool) == PM_FAIL) {
2890 DMEMIT("Fail");
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002891 return;
Joe Thornbere49e5822012-07-27 15:08:16 +01002892 }
2893
Joe Thornber991d9fa2011-10-31 20:21:18 +00002894 if (!tc->td)
2895 DMEMIT("-");
2896 else {
2897 switch (type) {
2898 case STATUSTYPE_INFO:
2899 r = dm_thin_get_mapped_count(tc->td, &mapped);
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002900 if (r) {
2901 DMERR("dm_thin_get_mapped_count returned %d", r);
2902 goto err;
2903 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002904
2905 r = dm_thin_get_highest_mapped_block(tc->td, &highest);
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002906 if (r < 0) {
2907 DMERR("dm_thin_get_highest_mapped_block returned %d", r);
2908 goto err;
2909 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002910
2911 DMEMIT("%llu ", mapped * tc->pool->sectors_per_block);
2912 if (r)
2913 DMEMIT("%llu", ((highest + 1) *
2914 tc->pool->sectors_per_block) - 1);
2915 else
2916 DMEMIT("-");
2917 break;
2918
2919 case STATUSTYPE_TABLE:
2920 DMEMIT("%s %lu",
2921 format_dev_t(buf, tc->pool_dev->bdev->bd_dev),
2922 (unsigned long) tc->dev_id);
Joe Thornber2dd9c252012-03-28 18:41:28 +01002923 if (tc->origin_dev)
2924 DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev));
Joe Thornber991d9fa2011-10-31 20:21:18 +00002925 break;
2926 }
2927 }
2928
Mikulas Patockafd7c0922013-03-01 22:45:44 +00002929 return;
2930
2931err:
2932 DMEMIT("Error");
Joe Thornber991d9fa2011-10-31 20:21:18 +00002933}
2934
2935static int thin_iterate_devices(struct dm_target *ti,
2936 iterate_devices_callout_fn fn, void *data)
2937{
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002938 sector_t blocks;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002939 struct thin_c *tc = ti->private;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002940 struct pool *pool = tc->pool;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002941
2942 /*
2943 * We can't call dm_pool_get_data_dev_size() since that blocks. So
2944 * we follow a more convoluted path through to the pool's target.
2945 */
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002946 if (!pool->ti)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002947 return 0; /* nothing is bound */
2948
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002949 blocks = pool->ti->len;
2950 (void) sector_div(blocks, pool->sectors_per_block);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002951 if (blocks)
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002952 return fn(ti, tc->pool_dev, 0, pool->sectors_per_block * blocks, data);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002953
2954 return 0;
2955}
2956
Joe Thornber991d9fa2011-10-31 20:21:18 +00002957static struct target_type thin_target = {
2958 .name = "thin",
Joe Thornberf046f892013-03-20 17:21:24 +00002959 .version = {1, 8, 0},
Joe Thornber991d9fa2011-10-31 20:21:18 +00002960 .module = THIS_MODULE,
2961 .ctr = thin_ctr,
2962 .dtr = thin_dtr,
2963 .map = thin_map,
Joe Thornbereb2aa482012-03-28 18:41:28 +01002964 .end_io = thin_endio,
Joe Thornber991d9fa2011-10-31 20:21:18 +00002965 .postsuspend = thin_postsuspend,
2966 .status = thin_status,
2967 .iterate_devices = thin_iterate_devices,
Joe Thornber991d9fa2011-10-31 20:21:18 +00002968};
2969
2970/*----------------------------------------------------------------*/
2971
2972static int __init dm_thin_init(void)
2973{
2974 int r;
2975
2976 pool_table_init();
2977
2978 r = dm_register_target(&thin_target);
2979 if (r)
2980 return r;
2981
2982 r = dm_register_target(&pool_target);
2983 if (r)
Mike Snitzera24c2562012-06-03 00:30:00 +01002984 goto bad_pool_target;
2985
2986 r = -ENOMEM;
2987
Mike Snitzera24c2562012-06-03 00:30:00 +01002988 _new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
2989 if (!_new_mapping_cache)
2990 goto bad_new_mapping_cache;
2991
Mike Snitzera24c2562012-06-03 00:30:00 +01002992 return 0;
2993
Mike Snitzera24c2562012-06-03 00:30:00 +01002994bad_new_mapping_cache:
Mike Snitzera24c2562012-06-03 00:30:00 +01002995 dm_unregister_target(&pool_target);
2996bad_pool_target:
2997 dm_unregister_target(&thin_target);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002998
2999 return r;
3000}
3001
3002static void dm_thin_exit(void)
3003{
3004 dm_unregister_target(&thin_target);
3005 dm_unregister_target(&pool_target);
Mike Snitzera24c2562012-06-03 00:30:00 +01003006
Mike Snitzera24c2562012-06-03 00:30:00 +01003007 kmem_cache_destroy(_new_mapping_cache);
Joe Thornber991d9fa2011-10-31 20:21:18 +00003008}
3009
3010module_init(dm_thin_init);
3011module_exit(dm_thin_exit);
3012
Alasdair G Kergon7cab8bf2012-05-12 01:43:19 +01003013MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
Joe Thornber991d9fa2011-10-31 20:21:18 +00003014MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
3015MODULE_LICENSE("GPL");