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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
29/*
30 * The block size of the device holding pool data must be
31 * between 64KB and 1GB.
32 */
33#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
34#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
35
36/*
Joe Thornber991d9fa2011-10-31 20:21:18 +000037 * Device id is restricted to 24 bits.
38 */
39#define MAX_DEV_ID ((1 << 24) - 1)
40
41/*
42 * How do we handle breaking sharing of data blocks?
43 * =================================================
44 *
45 * We use a standard copy-on-write btree to store the mappings for the
46 * devices (note I'm talking about copy-on-write of the metadata here, not
47 * the data). When you take an internal snapshot you clone the root node
48 * of the origin btree. After this there is no concept of an origin or a
49 * snapshot. They are just two device trees that happen to point to the
50 * same data blocks.
51 *
52 * When we get a write in we decide if it's to a shared data block using
53 * some timestamp magic. If it is, we have to break sharing.
54 *
55 * Let's say we write to a shared block in what was the origin. The
56 * steps are:
57 *
58 * i) plug io further to this physical block. (see bio_prison code).
59 *
60 * ii) quiesce any read io to that shared data block. Obviously
Mike Snitzer44feb382012-10-12 21:02:10 +010061 * including all devices that share this block. (see dm_deferred_set code)
Joe Thornber991d9fa2011-10-31 20:21:18 +000062 *
63 * iii) copy the data block to a newly allocate block. This step can be
64 * missed out if the io covers the block. (schedule_copy).
65 *
66 * iv) insert the new mapping into the origin's btree
Joe Thornberfe878f32012-03-28 18:41:24 +010067 * (process_prepared_mapping). This act of inserting breaks some
Joe Thornber991d9fa2011-10-31 20:21:18 +000068 * sharing of btree nodes between the two devices. Breaking sharing only
69 * effects the btree of that specific device. Btrees for the other
70 * devices that share the block never change. The btree for the origin
71 * device as it was after the last commit is untouched, ie. we're using
72 * persistent data structures in the functional programming sense.
73 *
74 * v) unplug io to this physical block, including the io that triggered
75 * the breaking of sharing.
76 *
77 * Steps (ii) and (iii) occur in parallel.
78 *
79 * The metadata _doesn't_ need to be committed before the io continues. We
80 * get away with this because the io is always written to a _new_ block.
81 * If there's a crash, then:
82 *
83 * - The origin mapping will point to the old origin block (the shared
84 * one). This will contain the data as it was before the io that triggered
85 * the breaking of sharing came in.
86 *
87 * - The snap mapping still points to the old block. As it would after
88 * the commit.
89 *
90 * The downside of this scheme is the timestamp magic isn't perfect, and
91 * will continue to think that data block in the snapshot device is shared
92 * even after the write to the origin has broken sharing. I suspect data
93 * blocks will typically be shared by many different devices, so we're
94 * breaking sharing n + 1 times, rather than n, where n is the number of
95 * devices that reference this data block. At the moment I think the
96 * benefits far, far outweigh the disadvantages.
97 */
98
99/*----------------------------------------------------------------*/
100
101/*
Joe Thornber991d9fa2011-10-31 20:21:18 +0000102 * Key building.
103 */
104static void build_data_key(struct dm_thin_device *td,
Mike Snitzer44feb382012-10-12 21:02:10 +0100105 dm_block_t b, struct dm_cell_key *key)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000106{
107 key->virtual = 0;
108 key->dev = dm_thin_dev_id(td);
109 key->block = b;
110}
111
112static void build_virtual_key(struct dm_thin_device *td, dm_block_t b,
Mike Snitzer44feb382012-10-12 21:02:10 +0100113 struct dm_cell_key *key)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000114{
115 key->virtual = 1;
116 key->dev = dm_thin_dev_id(td);
117 key->block = b;
118}
119
120/*----------------------------------------------------------------*/
121
122/*
123 * A pool device ties together a metadata device and a data device. It
124 * also provides the interface for creating and destroying internal
125 * devices.
126 */
Mike Snitzera24c2562012-06-03 00:30:00 +0100127struct dm_thin_new_mapping;
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100128
Joe Thornbere49e5822012-07-27 15:08:16 +0100129/*
130 * The pool runs in 3 modes. Ordered in degraded order for comparisons.
131 */
132enum pool_mode {
133 PM_WRITE, /* metadata may be changed */
134 PM_READ_ONLY, /* metadata may not be changed */
135 PM_FAIL, /* all I/O fails */
136};
137
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100138struct pool_features {
Joe Thornbere49e5822012-07-27 15:08:16 +0100139 enum pool_mode mode;
140
Mike Snitzer9bc142d2012-09-26 23:45:46 +0100141 bool zero_new_blocks:1;
142 bool discard_enabled:1;
143 bool discard_passdown:1;
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100144};
145
Joe Thornbere49e5822012-07-27 15:08:16 +0100146struct thin_c;
147typedef void (*process_bio_fn)(struct thin_c *tc, struct bio *bio);
148typedef void (*process_mapping_fn)(struct dm_thin_new_mapping *m);
149
Joe Thornber991d9fa2011-10-31 20:21:18 +0000150struct pool {
151 struct list_head list;
152 struct dm_target *ti; /* Only set if a pool target is bound */
153
154 struct mapped_device *pool_md;
155 struct block_device *md_dev;
156 struct dm_pool_metadata *pmd;
157
Joe Thornber991d9fa2011-10-31 20:21:18 +0000158 dm_block_t low_water_blocks;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100159 uint32_t sectors_per_block;
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100160 int sectors_per_block_shift;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000161
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100162 struct pool_features pf;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000163 unsigned low_water_triggered:1; /* A dm event has been sent */
164 unsigned no_free_space:1; /* A -ENOSPC warning has been issued */
165
Mike Snitzer44feb382012-10-12 21:02:10 +0100166 struct dm_bio_prison *prison;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000167 struct dm_kcopyd_client *copier;
168
169 struct workqueue_struct *wq;
170 struct work_struct worker;
Joe Thornber905e51b2012-03-28 18:41:27 +0100171 struct delayed_work waker;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000172
Joe Thornber905e51b2012-03-28 18:41:27 +0100173 unsigned long last_commit_jiffies;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100174 unsigned ref_count;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000175
176 spinlock_t lock;
177 struct bio_list deferred_bios;
178 struct bio_list deferred_flush_bios;
179 struct list_head prepared_mappings;
Joe Thornber104655f2012-03-28 18:41:28 +0100180 struct list_head prepared_discards;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000181
182 struct bio_list retry_on_resume_list;
183
Mike Snitzer44feb382012-10-12 21:02:10 +0100184 struct dm_deferred_set *shared_read_ds;
185 struct dm_deferred_set *all_io_ds;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000186
Mike Snitzera24c2562012-06-03 00:30:00 +0100187 struct dm_thin_new_mapping *next_mapping;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000188 mempool_t *mapping_pool;
189 mempool_t *endio_hook_pool;
Joe Thornbere49e5822012-07-27 15:08:16 +0100190
191 process_bio_fn process_bio;
192 process_bio_fn process_discard;
193
194 process_mapping_fn process_prepared_mapping;
195 process_mapping_fn process_prepared_discard;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000196};
197
Joe Thornbere49e5822012-07-27 15:08:16 +0100198static enum pool_mode get_pool_mode(struct pool *pool);
199static void set_pool_mode(struct pool *pool, enum pool_mode mode);
200
Joe Thornber991d9fa2011-10-31 20:21:18 +0000201/*
202 * Target context for a pool.
203 */
204struct pool_c {
205 struct dm_target *ti;
206 struct pool *pool;
207 struct dm_dev *data_dev;
208 struct dm_dev *metadata_dev;
209 struct dm_target_callbacks callbacks;
210
211 dm_block_t low_water_blocks;
Mike Snitzer0424caa2012-09-26 23:45:47 +0100212 struct pool_features requested_pf; /* Features requested during table load */
213 struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */
Joe Thornber991d9fa2011-10-31 20:21:18 +0000214};
215
216/*
217 * Target context for a thin.
218 */
219struct thin_c {
220 struct dm_dev *pool_dev;
Joe Thornber2dd9c252012-03-28 18:41:28 +0100221 struct dm_dev *origin_dev;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000222 dm_thin_id dev_id;
223
224 struct pool *pool;
225 struct dm_thin_device *td;
226};
227
228/*----------------------------------------------------------------*/
229
230/*
231 * A global list of pools that uses a struct mapped_device as a key.
232 */
233static struct dm_thin_pool_table {
234 struct mutex mutex;
235 struct list_head pools;
236} dm_thin_pool_table;
237
238static void pool_table_init(void)
239{
240 mutex_init(&dm_thin_pool_table.mutex);
241 INIT_LIST_HEAD(&dm_thin_pool_table.pools);
242}
243
244static void __pool_table_insert(struct pool *pool)
245{
246 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
247 list_add(&pool->list, &dm_thin_pool_table.pools);
248}
249
250static void __pool_table_remove(struct pool *pool)
251{
252 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
253 list_del(&pool->list);
254}
255
256static struct pool *__pool_table_lookup(struct mapped_device *md)
257{
258 struct pool *pool = NULL, *tmp;
259
260 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
261
262 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
263 if (tmp->pool_md == md) {
264 pool = tmp;
265 break;
266 }
267 }
268
269 return pool;
270}
271
272static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev)
273{
274 struct pool *pool = NULL, *tmp;
275
276 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
277
278 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
279 if (tmp->md_dev == md_dev) {
280 pool = tmp;
281 break;
282 }
283 }
284
285 return pool;
286}
287
288/*----------------------------------------------------------------*/
289
Mike Snitzera24c2562012-06-03 00:30:00 +0100290struct dm_thin_endio_hook {
Joe Thornbereb2aa482012-03-28 18:41:28 +0100291 struct thin_c *tc;
Mike Snitzer44feb382012-10-12 21:02:10 +0100292 struct dm_deferred_entry *shared_read_entry;
293 struct dm_deferred_entry *all_io_entry;
Mike Snitzera24c2562012-06-03 00:30:00 +0100294 struct dm_thin_new_mapping *overwrite_mapping;
Joe Thornbereb2aa482012-03-28 18:41:28 +0100295};
296
Joe Thornber991d9fa2011-10-31 20:21:18 +0000297static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master)
298{
299 struct bio *bio;
300 struct bio_list bios;
301
302 bio_list_init(&bios);
303 bio_list_merge(&bios, master);
304 bio_list_init(master);
305
306 while ((bio = bio_list_pop(&bios))) {
Mike Snitzera24c2562012-06-03 00:30:00 +0100307 struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;
308
Joe Thornbereb2aa482012-03-28 18:41:28 +0100309 if (h->tc == tc)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000310 bio_endio(bio, DM_ENDIO_REQUEUE);
311 else
312 bio_list_add(master, bio);
313 }
314}
315
316static void requeue_io(struct thin_c *tc)
317{
318 struct pool *pool = tc->pool;
319 unsigned long flags;
320
321 spin_lock_irqsave(&pool->lock, flags);
322 __requeue_bio_list(tc, &pool->deferred_bios);
323 __requeue_bio_list(tc, &pool->retry_on_resume_list);
324 spin_unlock_irqrestore(&pool->lock, flags);
325}
326
327/*
328 * This section of code contains the logic for processing a thin device's IO.
329 * Much of the code depends on pool object resources (lists, workqueues, etc)
330 * but most is exclusively called from the thin target rather than the thin-pool
331 * target.
332 */
333
334static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
335{
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100336 sector_t block_nr = bio->bi_sector;
337
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100338 if (tc->pool->sectors_per_block_shift < 0)
339 (void) sector_div(block_nr, tc->pool->sectors_per_block);
340 else
341 block_nr >>= tc->pool->sectors_per_block_shift;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100342
343 return block_nr;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000344}
345
346static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
347{
348 struct pool *pool = tc->pool;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100349 sector_t bi_sector = bio->bi_sector;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000350
351 bio->bi_bdev = tc->pool_dev->bdev;
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100352 if (tc->pool->sectors_per_block_shift < 0)
353 bio->bi_sector = (block * pool->sectors_per_block) +
354 sector_div(bi_sector, pool->sectors_per_block);
355 else
356 bio->bi_sector = (block << pool->sectors_per_block_shift) |
357 (bi_sector & (pool->sectors_per_block - 1));
Joe Thornber991d9fa2011-10-31 20:21:18 +0000358}
359
Joe Thornber2dd9c252012-03-28 18:41:28 +0100360static void remap_to_origin(struct thin_c *tc, struct bio *bio)
361{
362 bio->bi_bdev = tc->origin_dev->bdev;
363}
364
Joe Thornber4afdd682012-07-27 15:08:14 +0100365static int bio_triggers_commit(struct thin_c *tc, struct bio *bio)
366{
367 return (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) &&
368 dm_thin_changed_this_transaction(tc->td);
369}
370
Joe Thornber2dd9c252012-03-28 18:41:28 +0100371static void issue(struct thin_c *tc, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000372{
373 struct pool *pool = tc->pool;
374 unsigned long flags;
375
Joe Thornbere49e5822012-07-27 15:08:16 +0100376 if (!bio_triggers_commit(tc, bio)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000377 generic_make_request(bio);
Joe Thornbere49e5822012-07-27 15:08:16 +0100378 return;
379 }
380
381 /*
382 * Complete bio with an error if earlier I/O caused changes to
383 * the metadata that can't be committed e.g, due to I/O errors
384 * on the metadata device.
385 */
386 if (dm_thin_aborted_changes(tc->td)) {
387 bio_io_error(bio);
388 return;
389 }
390
391 /*
392 * Batch together any bios that trigger commits and then issue a
393 * single commit for them in process_deferred_bios().
394 */
395 spin_lock_irqsave(&pool->lock, flags);
396 bio_list_add(&pool->deferred_flush_bios, bio);
397 spin_unlock_irqrestore(&pool->lock, flags);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000398}
399
Joe Thornber2dd9c252012-03-28 18:41:28 +0100400static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio)
401{
402 remap_to_origin(tc, bio);
403 issue(tc, bio);
404}
405
406static void remap_and_issue(struct thin_c *tc, struct bio *bio,
407 dm_block_t block)
408{
409 remap(tc, bio, block);
410 issue(tc, bio);
411}
412
Joe Thornber991d9fa2011-10-31 20:21:18 +0000413/*
414 * wake_worker() is used when new work is queued and when pool_resume is
415 * ready to continue deferred IO processing.
416 */
417static void wake_worker(struct pool *pool)
418{
419 queue_work(pool->wq, &pool->worker);
420}
421
422/*----------------------------------------------------------------*/
423
424/*
425 * Bio endio functions.
426 */
Mike Snitzera24c2562012-06-03 00:30:00 +0100427struct dm_thin_new_mapping {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000428 struct list_head list;
429
Joe Thornbereb2aa482012-03-28 18:41:28 +0100430 unsigned quiesced:1;
431 unsigned prepared:1;
Joe Thornber104655f2012-03-28 18:41:28 +0100432 unsigned pass_discard:1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000433
434 struct thin_c *tc;
435 dm_block_t virt_block;
436 dm_block_t data_block;
Mike Snitzera24c2562012-06-03 00:30:00 +0100437 struct dm_bio_prison_cell *cell, *cell2;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000438 int err;
439
440 /*
441 * If the bio covers the whole area of a block then we can avoid
442 * zeroing or copying. Instead this bio is hooked. The bio will
443 * still be in the cell, so care has to be taken to avoid issuing
444 * the bio twice.
445 */
446 struct bio *bio;
447 bio_end_io_t *saved_bi_end_io;
448};
449
Mike Snitzera24c2562012-06-03 00:30:00 +0100450static void __maybe_add_mapping(struct dm_thin_new_mapping *m)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000451{
452 struct pool *pool = m->tc->pool;
453
Joe Thornbereb2aa482012-03-28 18:41:28 +0100454 if (m->quiesced && m->prepared) {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000455 list_add(&m->list, &pool->prepared_mappings);
456 wake_worker(pool);
457 }
458}
459
460static void copy_complete(int read_err, unsigned long write_err, void *context)
461{
462 unsigned long flags;
Mike Snitzera24c2562012-06-03 00:30:00 +0100463 struct dm_thin_new_mapping *m = context;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000464 struct pool *pool = m->tc->pool;
465
466 m->err = read_err || write_err ? -EIO : 0;
467
468 spin_lock_irqsave(&pool->lock, flags);
469 m->prepared = 1;
470 __maybe_add_mapping(m);
471 spin_unlock_irqrestore(&pool->lock, flags);
472}
473
474static void overwrite_endio(struct bio *bio, int err)
475{
476 unsigned long flags;
Mike Snitzera24c2562012-06-03 00:30:00 +0100477 struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;
478 struct dm_thin_new_mapping *m = h->overwrite_mapping;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000479 struct pool *pool = m->tc->pool;
480
481 m->err = err;
482
483 spin_lock_irqsave(&pool->lock, flags);
484 m->prepared = 1;
485 __maybe_add_mapping(m);
486 spin_unlock_irqrestore(&pool->lock, flags);
487}
488
Joe Thornber991d9fa2011-10-31 20:21:18 +0000489/*----------------------------------------------------------------*/
490
491/*
492 * Workqueue.
493 */
494
495/*
496 * Prepared mapping jobs.
497 */
498
499/*
500 * This sends the bios in the cell back to the deferred_bios list.
501 */
Mike Snitzera24c2562012-06-03 00:30:00 +0100502static void cell_defer(struct thin_c *tc, struct dm_bio_prison_cell *cell,
Joe Thornber991d9fa2011-10-31 20:21:18 +0000503 dm_block_t data_block)
504{
505 struct pool *pool = tc->pool;
506 unsigned long flags;
507
508 spin_lock_irqsave(&pool->lock, flags);
Mike Snitzer44feb382012-10-12 21:02:10 +0100509 dm_cell_release(cell, &pool->deferred_bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000510 spin_unlock_irqrestore(&tc->pool->lock, flags);
511
512 wake_worker(pool);
513}
514
515/*
516 * Same as cell_defer above, except it omits one particular detainee,
517 * a write bio that covers the block and has already been processed.
518 */
Mike Snitzera24c2562012-06-03 00:30:00 +0100519static void cell_defer_except(struct thin_c *tc, struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000520{
521 struct bio_list bios;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000522 struct pool *pool = tc->pool;
523 unsigned long flags;
524
525 bio_list_init(&bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000526
527 spin_lock_irqsave(&pool->lock, flags);
Mike Snitzer44feb382012-10-12 21:02:10 +0100528 dm_cell_release_no_holder(cell, &pool->deferred_bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000529 spin_unlock_irqrestore(&pool->lock, flags);
530
531 wake_worker(pool);
532}
533
Joe Thornbere49e5822012-07-27 15:08:16 +0100534static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
535{
536 if (m->bio)
537 m->bio->bi_end_io = m->saved_bi_end_io;
Mike Snitzer44feb382012-10-12 21:02:10 +0100538 dm_cell_error(m->cell);
Joe Thornbere49e5822012-07-27 15:08:16 +0100539 list_del(&m->list);
540 mempool_free(m, m->tc->pool->mapping_pool);
541}
Mike Snitzera24c2562012-06-03 00:30:00 +0100542static void process_prepared_mapping(struct dm_thin_new_mapping *m)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000543{
544 struct thin_c *tc = m->tc;
545 struct bio *bio;
546 int r;
547
548 bio = m->bio;
549 if (bio)
550 bio->bi_end_io = m->saved_bi_end_io;
551
552 if (m->err) {
Mike Snitzer44feb382012-10-12 21:02:10 +0100553 dm_cell_error(m->cell);
Joe Thornber905386f2012-07-27 15:08:05 +0100554 goto out;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000555 }
556
557 /*
558 * Commit the prepared block into the mapping btree.
559 * Any I/O for this block arriving after this point will get
560 * remapped to it directly.
561 */
562 r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);
563 if (r) {
564 DMERR("dm_thin_insert_block() failed");
Mike Snitzer44feb382012-10-12 21:02:10 +0100565 dm_cell_error(m->cell);
Joe Thornber905386f2012-07-27 15:08:05 +0100566 goto out;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000567 }
568
569 /*
570 * Release any bios held while the block was being provisioned.
571 * If we are processing a write bio that completely covers the block,
572 * we already processed it so can ignore it now when processing
573 * the bios in the cell.
574 */
575 if (bio) {
Joe Thornber6f94a4c2012-03-28 18:41:23 +0100576 cell_defer_except(tc, m->cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000577 bio_endio(bio, 0);
578 } else
579 cell_defer(tc, m->cell, m->data_block);
580
Joe Thornber905386f2012-07-27 15:08:05 +0100581out:
Joe Thornber991d9fa2011-10-31 20:21:18 +0000582 list_del(&m->list);
583 mempool_free(m, tc->pool->mapping_pool);
584}
585
Joe Thornbere49e5822012-07-27 15:08:16 +0100586static void process_prepared_discard_fail(struct dm_thin_new_mapping *m)
Joe Thornber104655f2012-03-28 18:41:28 +0100587{
Joe Thornber104655f2012-03-28 18:41:28 +0100588 struct thin_c *tc = m->tc;
589
Joe Thornbere49e5822012-07-27 15:08:16 +0100590 bio_io_error(m->bio);
591 cell_defer_except(tc, m->cell);
592 cell_defer_except(tc, m->cell2);
593 mempool_free(m, tc->pool->mapping_pool);
594}
Joe Thornber104655f2012-03-28 18:41:28 +0100595
Joe Thornbere49e5822012-07-27 15:08:16 +0100596static void process_prepared_discard_passdown(struct dm_thin_new_mapping *m)
597{
598 struct thin_c *tc = m->tc;
599
Joe Thornber104655f2012-03-28 18:41:28 +0100600 if (m->pass_discard)
601 remap_and_issue(tc, m->bio, m->data_block);
602 else
603 bio_endio(m->bio, 0);
604
605 cell_defer_except(tc, m->cell);
606 cell_defer_except(tc, m->cell2);
607 mempool_free(m, tc->pool->mapping_pool);
608}
609
Joe Thornbere49e5822012-07-27 15:08:16 +0100610static void process_prepared_discard(struct dm_thin_new_mapping *m)
611{
612 int r;
613 struct thin_c *tc = m->tc;
614
615 r = dm_thin_remove_block(tc->td, m->virt_block);
616 if (r)
617 DMERR("dm_thin_remove_block() failed");
618
619 process_prepared_discard_passdown(m);
620}
621
Joe Thornber104655f2012-03-28 18:41:28 +0100622static void process_prepared(struct pool *pool, struct list_head *head,
Joe Thornbere49e5822012-07-27 15:08:16 +0100623 process_mapping_fn *fn)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000624{
625 unsigned long flags;
626 struct list_head maps;
Mike Snitzera24c2562012-06-03 00:30:00 +0100627 struct dm_thin_new_mapping *m, *tmp;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000628
629 INIT_LIST_HEAD(&maps);
630 spin_lock_irqsave(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +0100631 list_splice_init(head, &maps);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000632 spin_unlock_irqrestore(&pool->lock, flags);
633
634 list_for_each_entry_safe(m, tmp, &maps, list)
Joe Thornbere49e5822012-07-27 15:08:16 +0100635 (*fn)(m);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000636}
637
638/*
639 * Deferred bio jobs.
640 */
Joe Thornber104655f2012-03-28 18:41:28 +0100641static int io_overlaps_block(struct pool *pool, struct bio *bio)
642{
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100643 return bio->bi_size == (pool->sectors_per_block << SECTOR_SHIFT);
Joe Thornber104655f2012-03-28 18:41:28 +0100644}
645
Joe Thornber991d9fa2011-10-31 20:21:18 +0000646static int io_overwrites_block(struct pool *pool, struct bio *bio)
647{
Joe Thornber104655f2012-03-28 18:41:28 +0100648 return (bio_data_dir(bio) == WRITE) &&
649 io_overlaps_block(pool, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000650}
651
652static void save_and_set_endio(struct bio *bio, bio_end_io_t **save,
653 bio_end_io_t *fn)
654{
655 *save = bio->bi_end_io;
656 bio->bi_end_io = fn;
657}
658
659static int ensure_next_mapping(struct pool *pool)
660{
661 if (pool->next_mapping)
662 return 0;
663
664 pool->next_mapping = mempool_alloc(pool->mapping_pool, GFP_ATOMIC);
665
666 return pool->next_mapping ? 0 : -ENOMEM;
667}
668
Mike Snitzera24c2562012-06-03 00:30:00 +0100669static struct dm_thin_new_mapping *get_next_mapping(struct pool *pool)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000670{
Mike Snitzera24c2562012-06-03 00:30:00 +0100671 struct dm_thin_new_mapping *r = pool->next_mapping;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000672
673 BUG_ON(!pool->next_mapping);
674
675 pool->next_mapping = NULL;
676
677 return r;
678}
679
680static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
Joe Thornber2dd9c252012-03-28 18:41:28 +0100681 struct dm_dev *origin, dm_block_t data_origin,
682 dm_block_t data_dest,
Mike Snitzera24c2562012-06-03 00:30:00 +0100683 struct dm_bio_prison_cell *cell, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000684{
685 int r;
686 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +0100687 struct dm_thin_new_mapping *m = get_next_mapping(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000688
689 INIT_LIST_HEAD(&m->list);
Joe Thornbereb2aa482012-03-28 18:41:28 +0100690 m->quiesced = 0;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000691 m->prepared = 0;
692 m->tc = tc;
693 m->virt_block = virt_block;
694 m->data_block = data_dest;
695 m->cell = cell;
696 m->err = 0;
697 m->bio = NULL;
698
Mike Snitzer44feb382012-10-12 21:02:10 +0100699 if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list))
Joe Thornbereb2aa482012-03-28 18:41:28 +0100700 m->quiesced = 1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000701
702 /*
703 * IO to pool_dev remaps to the pool target's data_dev.
704 *
705 * If the whole block of data is being overwritten, we can issue the
706 * bio immediately. Otherwise we use kcopyd to clone the data first.
707 */
708 if (io_overwrites_block(pool, bio)) {
Mike Snitzera24c2562012-06-03 00:30:00 +0100709 struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;
710
Joe Thornbereb2aa482012-03-28 18:41:28 +0100711 h->overwrite_mapping = m;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000712 m->bio = bio;
713 save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000714 remap_and_issue(tc, bio, data_dest);
715 } else {
716 struct dm_io_region from, to;
717
Joe Thornber2dd9c252012-03-28 18:41:28 +0100718 from.bdev = origin->bdev;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000719 from.sector = data_origin * pool->sectors_per_block;
720 from.count = pool->sectors_per_block;
721
722 to.bdev = tc->pool_dev->bdev;
723 to.sector = data_dest * pool->sectors_per_block;
724 to.count = pool->sectors_per_block;
725
726 r = dm_kcopyd_copy(pool->copier, &from, 1, &to,
727 0, copy_complete, m);
728 if (r < 0) {
729 mempool_free(m, pool->mapping_pool);
730 DMERR("dm_kcopyd_copy() failed");
Mike Snitzer44feb382012-10-12 21:02:10 +0100731 dm_cell_error(cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000732 }
733 }
734}
735
Joe Thornber2dd9c252012-03-28 18:41:28 +0100736static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block,
737 dm_block_t data_origin, dm_block_t data_dest,
Mike Snitzera24c2562012-06-03 00:30:00 +0100738 struct dm_bio_prison_cell *cell, struct bio *bio)
Joe Thornber2dd9c252012-03-28 18:41:28 +0100739{
740 schedule_copy(tc, virt_block, tc->pool_dev,
741 data_origin, data_dest, cell, bio);
742}
743
744static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block,
745 dm_block_t data_dest,
Mike Snitzera24c2562012-06-03 00:30:00 +0100746 struct dm_bio_prison_cell *cell, struct bio *bio)
Joe Thornber2dd9c252012-03-28 18:41:28 +0100747{
748 schedule_copy(tc, virt_block, tc->origin_dev,
749 virt_block, data_dest, cell, bio);
750}
751
Joe Thornber991d9fa2011-10-31 20:21:18 +0000752static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
Mike Snitzera24c2562012-06-03 00:30:00 +0100753 dm_block_t data_block, struct dm_bio_prison_cell *cell,
Joe Thornber991d9fa2011-10-31 20:21:18 +0000754 struct bio *bio)
755{
756 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +0100757 struct dm_thin_new_mapping *m = get_next_mapping(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000758
759 INIT_LIST_HEAD(&m->list);
Joe Thornbereb2aa482012-03-28 18:41:28 +0100760 m->quiesced = 1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000761 m->prepared = 0;
762 m->tc = tc;
763 m->virt_block = virt_block;
764 m->data_block = data_block;
765 m->cell = cell;
766 m->err = 0;
767 m->bio = NULL;
768
769 /*
770 * If the whole block of data is being overwritten or we are not
771 * zeroing pre-existing data, we can issue the bio immediately.
772 * Otherwise we use kcopyd to zero the data first.
773 */
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100774 if (!pool->pf.zero_new_blocks)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000775 process_prepared_mapping(m);
776
777 else if (io_overwrites_block(pool, bio)) {
Mike Snitzera24c2562012-06-03 00:30:00 +0100778 struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;
779
Joe Thornbereb2aa482012-03-28 18:41:28 +0100780 h->overwrite_mapping = m;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000781 m->bio = bio;
782 save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000783 remap_and_issue(tc, bio, data_block);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000784 } else {
785 int r;
786 struct dm_io_region to;
787
788 to.bdev = tc->pool_dev->bdev;
789 to.sector = data_block * pool->sectors_per_block;
790 to.count = pool->sectors_per_block;
791
792 r = dm_kcopyd_zero(pool->copier, 1, &to, 0, copy_complete, m);
793 if (r < 0) {
794 mempool_free(m, pool->mapping_pool);
795 DMERR("dm_kcopyd_zero() failed");
Mike Snitzer44feb382012-10-12 21:02:10 +0100796 dm_cell_error(cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000797 }
798 }
799}
800
Joe Thornbere49e5822012-07-27 15:08:16 +0100801static int commit(struct pool *pool)
802{
803 int r;
804
805 r = dm_pool_commit_metadata(pool->pmd);
806 if (r)
807 DMERR("commit failed, error = %d", r);
808
809 return r;
810}
811
812/*
813 * A non-zero return indicates read_only or fail_io mode.
814 * Many callers don't care about the return value.
815 */
816static int commit_or_fallback(struct pool *pool)
817{
818 int r;
819
820 if (get_pool_mode(pool) != PM_WRITE)
821 return -EINVAL;
822
823 r = commit(pool);
824 if (r)
825 set_pool_mode(pool, PM_READ_ONLY);
826
827 return r;
828}
829
Joe Thornber991d9fa2011-10-31 20:21:18 +0000830static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
831{
832 int r;
833 dm_block_t free_blocks;
834 unsigned long flags;
835 struct pool *pool = tc->pool;
836
837 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
838 if (r)
839 return r;
840
841 if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) {
842 DMWARN("%s: reached low water mark, sending event.",
843 dm_device_name(pool->pool_md));
844 spin_lock_irqsave(&pool->lock, flags);
845 pool->low_water_triggered = 1;
846 spin_unlock_irqrestore(&pool->lock, flags);
847 dm_table_event(pool->ti->table);
848 }
849
850 if (!free_blocks) {
851 if (pool->no_free_space)
852 return -ENOSPC;
853 else {
854 /*
855 * Try to commit to see if that will free up some
856 * more space.
857 */
Joe Thornbere49e5822012-07-27 15:08:16 +0100858 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000859
860 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
861 if (r)
862 return r;
863
864 /*
865 * If we still have no space we set a flag to avoid
866 * doing all this checking and return -ENOSPC.
867 */
868 if (!free_blocks) {
869 DMWARN("%s: no free space available.",
870 dm_device_name(pool->pool_md));
871 spin_lock_irqsave(&pool->lock, flags);
872 pool->no_free_space = 1;
873 spin_unlock_irqrestore(&pool->lock, flags);
874 return -ENOSPC;
875 }
876 }
877 }
878
879 r = dm_pool_alloc_data_block(pool->pmd, result);
880 if (r)
881 return r;
882
883 return 0;
884}
885
886/*
887 * If we have run out of space, queue bios until the device is
888 * resumed, presumably after having been reloaded with more space.
889 */
890static void retry_on_resume(struct bio *bio)
891{
Mike Snitzera24c2562012-06-03 00:30:00 +0100892 struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;
Joe Thornbereb2aa482012-03-28 18:41:28 +0100893 struct thin_c *tc = h->tc;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000894 struct pool *pool = tc->pool;
895 unsigned long flags;
896
897 spin_lock_irqsave(&pool->lock, flags);
898 bio_list_add(&pool->retry_on_resume_list, bio);
899 spin_unlock_irqrestore(&pool->lock, flags);
900}
901
Mike Snitzera24c2562012-06-03 00:30:00 +0100902static void no_space(struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000903{
904 struct bio *bio;
905 struct bio_list bios;
906
907 bio_list_init(&bios);
Mike Snitzer44feb382012-10-12 21:02:10 +0100908 dm_cell_release(cell, &bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000909
910 while ((bio = bio_list_pop(&bios)))
911 retry_on_resume(bio);
912}
913
Joe Thornber104655f2012-03-28 18:41:28 +0100914static void process_discard(struct thin_c *tc, struct bio *bio)
915{
916 int r;
Mike Snitzerc3a0ce22012-05-12 01:43:16 +0100917 unsigned long flags;
Joe Thornber104655f2012-03-28 18:41:28 +0100918 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +0100919 struct dm_bio_prison_cell *cell, *cell2;
Mike Snitzer44feb382012-10-12 21:02:10 +0100920 struct dm_cell_key key, key2;
Joe Thornber104655f2012-03-28 18:41:28 +0100921 dm_block_t block = get_bio_block(tc, bio);
922 struct dm_thin_lookup_result lookup_result;
Mike Snitzera24c2562012-06-03 00:30:00 +0100923 struct dm_thin_new_mapping *m;
Joe Thornber104655f2012-03-28 18:41:28 +0100924
925 build_virtual_key(tc->td, block, &key);
Mike Snitzer44feb382012-10-12 21:02:10 +0100926 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell))
Joe Thornber104655f2012-03-28 18:41:28 +0100927 return;
928
929 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
930 switch (r) {
931 case 0:
932 /*
933 * Check nobody is fiddling with this pool block. This can
934 * happen if someone's in the process of breaking sharing
935 * on this block.
936 */
937 build_data_key(tc->td, lookup_result.block, &key2);
Mike Snitzer44feb382012-10-12 21:02:10 +0100938 if (dm_bio_detain(tc->pool->prison, &key2, bio, &cell2)) {
939 dm_cell_release_singleton(cell, bio);
Joe Thornber104655f2012-03-28 18:41:28 +0100940 break;
941 }
942
943 if (io_overlaps_block(pool, bio)) {
944 /*
945 * IO may still be going to the destination block. We must
946 * quiesce before we can do the removal.
947 */
948 m = get_next_mapping(pool);
949 m->tc = tc;
Mike Snitzer17b7d632012-07-27 15:07:57 +0100950 m->pass_discard = (!lookup_result.shared) && pool->pf.discard_passdown;
Joe Thornber104655f2012-03-28 18:41:28 +0100951 m->virt_block = block;
952 m->data_block = lookup_result.block;
953 m->cell = cell;
954 m->cell2 = cell2;
955 m->err = 0;
956 m->bio = bio;
957
Mike Snitzer44feb382012-10-12 21:02:10 +0100958 if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) {
Mike Snitzerc3a0ce22012-05-12 01:43:16 +0100959 spin_lock_irqsave(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +0100960 list_add(&m->list, &pool->prepared_discards);
Mike Snitzerc3a0ce22012-05-12 01:43:16 +0100961 spin_unlock_irqrestore(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +0100962 wake_worker(pool);
963 }
964 } else {
965 /*
Mikulas Patocka49296302012-07-27 15:08:03 +0100966 * The DM core makes sure that the discard doesn't span
967 * a block boundary. So we submit the discard of a
968 * partial block appropriately.
Joe Thornber104655f2012-03-28 18:41:28 +0100969 */
Mike Snitzer44feb382012-10-12 21:02:10 +0100970 dm_cell_release_singleton(cell, bio);
971 dm_cell_release_singleton(cell2, bio);
Mikulas Patocka650d2a02012-07-20 14:25:05 +0100972 if ((!lookup_result.shared) && pool->pf.discard_passdown)
973 remap_and_issue(tc, bio, lookup_result.block);
974 else
975 bio_endio(bio, 0);
Joe Thornber104655f2012-03-28 18:41:28 +0100976 }
977 break;
978
979 case -ENODATA:
980 /*
981 * It isn't provisioned, just forget it.
982 */
Mike Snitzer44feb382012-10-12 21:02:10 +0100983 dm_cell_release_singleton(cell, bio);
Joe Thornber104655f2012-03-28 18:41:28 +0100984 bio_endio(bio, 0);
985 break;
986
987 default:
988 DMERR("discard: find block unexpectedly returned %d", r);
Mike Snitzer44feb382012-10-12 21:02:10 +0100989 dm_cell_release_singleton(cell, bio);
Joe Thornber104655f2012-03-28 18:41:28 +0100990 bio_io_error(bio);
991 break;
992 }
993}
994
Joe Thornber991d9fa2011-10-31 20:21:18 +0000995static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
Mike Snitzer44feb382012-10-12 21:02:10 +0100996 struct dm_cell_key *key,
Joe Thornber991d9fa2011-10-31 20:21:18 +0000997 struct dm_thin_lookup_result *lookup_result,
Mike Snitzera24c2562012-06-03 00:30:00 +0100998 struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000999{
1000 int r;
1001 dm_block_t data_block;
1002
1003 r = alloc_data_block(tc, &data_block);
1004 switch (r) {
1005 case 0:
Joe Thornber2dd9c252012-03-28 18:41:28 +01001006 schedule_internal_copy(tc, block, lookup_result->block,
1007 data_block, cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001008 break;
1009
1010 case -ENOSPC:
1011 no_space(cell);
1012 break;
1013
1014 default:
1015 DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);
Mike Snitzer44feb382012-10-12 21:02:10 +01001016 dm_cell_error(cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001017 break;
1018 }
1019}
1020
1021static void process_shared_bio(struct thin_c *tc, struct bio *bio,
1022 dm_block_t block,
1023 struct dm_thin_lookup_result *lookup_result)
1024{
Mike Snitzera24c2562012-06-03 00:30:00 +01001025 struct dm_bio_prison_cell *cell;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001026 struct pool *pool = tc->pool;
Mike Snitzer44feb382012-10-12 21:02:10 +01001027 struct dm_cell_key key;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001028
1029 /*
1030 * If cell is already occupied, then sharing is already in the process
1031 * of being broken so we have nothing further to do here.
1032 */
1033 build_data_key(tc->td, lookup_result->block, &key);
Mike Snitzer44feb382012-10-12 21:02:10 +01001034 if (dm_bio_detain(pool->prison, &key, bio, &cell))
Joe Thornber991d9fa2011-10-31 20:21:18 +00001035 return;
1036
Joe Thornber60049702012-07-27 15:08:06 +01001037 if (bio_data_dir(bio) == WRITE && bio->bi_size)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001038 break_sharing(tc, bio, block, &key, lookup_result, cell);
1039 else {
Mike Snitzera24c2562012-06-03 00:30:00 +01001040 struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001041
Mike Snitzer44feb382012-10-12 21:02:10 +01001042 h->shared_read_entry = dm_deferred_entry_inc(pool->shared_read_ds);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001043
Mike Snitzer44feb382012-10-12 21:02:10 +01001044 dm_cell_release_singleton(cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001045 remap_and_issue(tc, bio, lookup_result->block);
1046 }
1047}
1048
1049static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block,
Mike Snitzera24c2562012-06-03 00:30:00 +01001050 struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001051{
1052 int r;
1053 dm_block_t data_block;
1054
1055 /*
1056 * Remap empty bios (flushes) immediately, without provisioning.
1057 */
1058 if (!bio->bi_size) {
Mike Snitzer44feb382012-10-12 21:02:10 +01001059 dm_cell_release_singleton(cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001060 remap_and_issue(tc, bio, 0);
1061 return;
1062 }
1063
1064 /*
1065 * Fill read bios with zeroes and complete them immediately.
1066 */
1067 if (bio_data_dir(bio) == READ) {
1068 zero_fill_bio(bio);
Mike Snitzer44feb382012-10-12 21:02:10 +01001069 dm_cell_release_singleton(cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001070 bio_endio(bio, 0);
1071 return;
1072 }
1073
1074 r = alloc_data_block(tc, &data_block);
1075 switch (r) {
1076 case 0:
Joe Thornber2dd9c252012-03-28 18:41:28 +01001077 if (tc->origin_dev)
1078 schedule_external_copy(tc, block, data_block, cell, bio);
1079 else
1080 schedule_zero(tc, block, data_block, cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001081 break;
1082
1083 case -ENOSPC:
1084 no_space(cell);
1085 break;
1086
1087 default:
1088 DMERR("%s: alloc_data_block() failed, error = %d", __func__, r);
Joe Thornbere49e5822012-07-27 15:08:16 +01001089 set_pool_mode(tc->pool, PM_READ_ONLY);
Mike Snitzer44feb382012-10-12 21:02:10 +01001090 dm_cell_error(cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001091 break;
1092 }
1093}
1094
1095static void process_bio(struct thin_c *tc, struct bio *bio)
1096{
1097 int r;
1098 dm_block_t block = get_bio_block(tc, bio);
Mike Snitzera24c2562012-06-03 00:30:00 +01001099 struct dm_bio_prison_cell *cell;
Mike Snitzer44feb382012-10-12 21:02:10 +01001100 struct dm_cell_key key;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001101 struct dm_thin_lookup_result lookup_result;
1102
1103 /*
1104 * If cell is already occupied, then the block is already
1105 * being provisioned so we have nothing further to do here.
1106 */
1107 build_virtual_key(tc->td, block, &key);
Mike Snitzer44feb382012-10-12 21:02:10 +01001108 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell))
Joe Thornber991d9fa2011-10-31 20:21:18 +00001109 return;
1110
1111 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1112 switch (r) {
1113 case 0:
1114 /*
1115 * We can release this cell now. This thread is the only
1116 * one that puts bios into a cell, and we know there were
1117 * no preceding bios.
1118 */
1119 /*
1120 * TODO: this will probably have to change when discard goes
1121 * back in.
1122 */
Mike Snitzer44feb382012-10-12 21:02:10 +01001123 dm_cell_release_singleton(cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001124
1125 if (lookup_result.shared)
1126 process_shared_bio(tc, bio, block, &lookup_result);
1127 else
1128 remap_and_issue(tc, bio, lookup_result.block);
1129 break;
1130
1131 case -ENODATA:
Joe Thornber2dd9c252012-03-28 18:41:28 +01001132 if (bio_data_dir(bio) == READ && tc->origin_dev) {
Mike Snitzer44feb382012-10-12 21:02:10 +01001133 dm_cell_release_singleton(cell, bio);
Joe Thornber2dd9c252012-03-28 18:41:28 +01001134 remap_to_origin_and_issue(tc, bio);
1135 } else
1136 provision_block(tc, bio, block, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001137 break;
1138
1139 default:
1140 DMERR("dm_thin_find_block() failed, error = %d", r);
Mike Snitzer44feb382012-10-12 21:02:10 +01001141 dm_cell_release_singleton(cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001142 bio_io_error(bio);
1143 break;
1144 }
1145}
1146
Joe Thornbere49e5822012-07-27 15:08:16 +01001147static void process_bio_read_only(struct thin_c *tc, struct bio *bio)
1148{
1149 int r;
1150 int rw = bio_data_dir(bio);
1151 dm_block_t block = get_bio_block(tc, bio);
1152 struct dm_thin_lookup_result lookup_result;
1153
1154 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1155 switch (r) {
1156 case 0:
1157 if (lookup_result.shared && (rw == WRITE) && bio->bi_size)
1158 bio_io_error(bio);
1159 else
1160 remap_and_issue(tc, bio, lookup_result.block);
1161 break;
1162
1163 case -ENODATA:
1164 if (rw != READ) {
1165 bio_io_error(bio);
1166 break;
1167 }
1168
1169 if (tc->origin_dev) {
1170 remap_to_origin_and_issue(tc, bio);
1171 break;
1172 }
1173
1174 zero_fill_bio(bio);
1175 bio_endio(bio, 0);
1176 break;
1177
1178 default:
1179 DMERR("dm_thin_find_block() failed, error = %d", r);
1180 bio_io_error(bio);
1181 break;
1182 }
1183}
1184
1185static void process_bio_fail(struct thin_c *tc, struct bio *bio)
1186{
1187 bio_io_error(bio);
1188}
1189
Joe Thornber905e51b2012-03-28 18:41:27 +01001190static int need_commit_due_to_time(struct pool *pool)
1191{
1192 return jiffies < pool->last_commit_jiffies ||
1193 jiffies > pool->last_commit_jiffies + COMMIT_PERIOD;
1194}
1195
Joe Thornber991d9fa2011-10-31 20:21:18 +00001196static void process_deferred_bios(struct pool *pool)
1197{
1198 unsigned long flags;
1199 struct bio *bio;
1200 struct bio_list bios;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001201
1202 bio_list_init(&bios);
1203
1204 spin_lock_irqsave(&pool->lock, flags);
1205 bio_list_merge(&bios, &pool->deferred_bios);
1206 bio_list_init(&pool->deferred_bios);
1207 spin_unlock_irqrestore(&pool->lock, flags);
1208
1209 while ((bio = bio_list_pop(&bios))) {
Mike Snitzera24c2562012-06-03 00:30:00 +01001210 struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr;
Joe Thornbereb2aa482012-03-28 18:41:28 +01001211 struct thin_c *tc = h->tc;
1212
Joe Thornber991d9fa2011-10-31 20:21:18 +00001213 /*
1214 * If we've got no free new_mapping structs, and processing
1215 * this bio might require one, we pause until there are some
1216 * prepared mappings to process.
1217 */
1218 if (ensure_next_mapping(pool)) {
1219 spin_lock_irqsave(&pool->lock, flags);
1220 bio_list_merge(&pool->deferred_bios, &bios);
1221 spin_unlock_irqrestore(&pool->lock, flags);
1222
1223 break;
1224 }
Joe Thornber104655f2012-03-28 18:41:28 +01001225
1226 if (bio->bi_rw & REQ_DISCARD)
Joe Thornbere49e5822012-07-27 15:08:16 +01001227 pool->process_discard(tc, bio);
Joe Thornber104655f2012-03-28 18:41:28 +01001228 else
Joe Thornbere49e5822012-07-27 15:08:16 +01001229 pool->process_bio(tc, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001230 }
1231
1232 /*
1233 * If there are any deferred flush bios, we must commit
1234 * the metadata before issuing them.
1235 */
1236 bio_list_init(&bios);
1237 spin_lock_irqsave(&pool->lock, flags);
1238 bio_list_merge(&bios, &pool->deferred_flush_bios);
1239 bio_list_init(&pool->deferred_flush_bios);
1240 spin_unlock_irqrestore(&pool->lock, flags);
1241
Joe Thornber905e51b2012-03-28 18:41:27 +01001242 if (bio_list_empty(&bios) && !need_commit_due_to_time(pool))
Joe Thornber991d9fa2011-10-31 20:21:18 +00001243 return;
1244
Joe Thornbere49e5822012-07-27 15:08:16 +01001245 if (commit_or_fallback(pool)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001246 while ((bio = bio_list_pop(&bios)))
1247 bio_io_error(bio);
1248 return;
1249 }
Joe Thornber905e51b2012-03-28 18:41:27 +01001250 pool->last_commit_jiffies = jiffies;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001251
1252 while ((bio = bio_list_pop(&bios)))
1253 generic_make_request(bio);
1254}
1255
1256static void do_worker(struct work_struct *ws)
1257{
1258 struct pool *pool = container_of(ws, struct pool, worker);
1259
Joe Thornbere49e5822012-07-27 15:08:16 +01001260 process_prepared(pool, &pool->prepared_mappings, &pool->process_prepared_mapping);
1261 process_prepared(pool, &pool->prepared_discards, &pool->process_prepared_discard);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001262 process_deferred_bios(pool);
1263}
1264
Joe Thornber905e51b2012-03-28 18:41:27 +01001265/*
1266 * We want to commit periodically so that not too much
1267 * unwritten data builds up.
1268 */
1269static void do_waker(struct work_struct *ws)
1270{
1271 struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker);
1272 wake_worker(pool);
1273 queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD);
1274}
1275
Joe Thornber991d9fa2011-10-31 20:21:18 +00001276/*----------------------------------------------------------------*/
1277
Joe Thornbere49e5822012-07-27 15:08:16 +01001278static enum pool_mode get_pool_mode(struct pool *pool)
1279{
1280 return pool->pf.mode;
1281}
1282
1283static void set_pool_mode(struct pool *pool, enum pool_mode mode)
1284{
1285 int r;
1286
1287 pool->pf.mode = mode;
1288
1289 switch (mode) {
1290 case PM_FAIL:
1291 DMERR("switching pool to failure mode");
1292 pool->process_bio = process_bio_fail;
1293 pool->process_discard = process_bio_fail;
1294 pool->process_prepared_mapping = process_prepared_mapping_fail;
1295 pool->process_prepared_discard = process_prepared_discard_fail;
1296 break;
1297
1298 case PM_READ_ONLY:
1299 DMERR("switching pool to read-only mode");
1300 r = dm_pool_abort_metadata(pool->pmd);
1301 if (r) {
1302 DMERR("aborting transaction failed");
1303 set_pool_mode(pool, PM_FAIL);
1304 } else {
1305 dm_pool_metadata_read_only(pool->pmd);
1306 pool->process_bio = process_bio_read_only;
1307 pool->process_discard = process_discard;
1308 pool->process_prepared_mapping = process_prepared_mapping_fail;
1309 pool->process_prepared_discard = process_prepared_discard_passdown;
1310 }
1311 break;
1312
1313 case PM_WRITE:
1314 pool->process_bio = process_bio;
1315 pool->process_discard = process_discard;
1316 pool->process_prepared_mapping = process_prepared_mapping;
1317 pool->process_prepared_discard = process_prepared_discard;
1318 break;
1319 }
1320}
1321
1322/*----------------------------------------------------------------*/
1323
Joe Thornber991d9fa2011-10-31 20:21:18 +00001324/*
1325 * Mapping functions.
1326 */
1327
1328/*
1329 * Called only while mapping a thin bio to hand it over to the workqueue.
1330 */
1331static void thin_defer_bio(struct thin_c *tc, struct bio *bio)
1332{
1333 unsigned long flags;
1334 struct pool *pool = tc->pool;
1335
1336 spin_lock_irqsave(&pool->lock, flags);
1337 bio_list_add(&pool->deferred_bios, bio);
1338 spin_unlock_irqrestore(&pool->lock, flags);
1339
1340 wake_worker(pool);
1341}
1342
Mike Snitzera24c2562012-06-03 00:30:00 +01001343static struct dm_thin_endio_hook *thin_hook_bio(struct thin_c *tc, struct bio *bio)
Joe Thornbereb2aa482012-03-28 18:41:28 +01001344{
1345 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +01001346 struct dm_thin_endio_hook *h = mempool_alloc(pool->endio_hook_pool, GFP_NOIO);
Joe Thornbereb2aa482012-03-28 18:41:28 +01001347
1348 h->tc = tc;
1349 h->shared_read_entry = NULL;
Mike Snitzer44feb382012-10-12 21:02:10 +01001350 h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : dm_deferred_entry_inc(pool->all_io_ds);
Joe Thornbereb2aa482012-03-28 18:41:28 +01001351 h->overwrite_mapping = NULL;
1352
1353 return h;
1354}
1355
Joe Thornber991d9fa2011-10-31 20:21:18 +00001356/*
1357 * Non-blocking function called from the thin target's map function.
1358 */
1359static int thin_bio_map(struct dm_target *ti, struct bio *bio,
1360 union map_info *map_context)
1361{
1362 int r;
1363 struct thin_c *tc = ti->private;
1364 dm_block_t block = get_bio_block(tc, bio);
1365 struct dm_thin_device *td = tc->td;
1366 struct dm_thin_lookup_result result;
1367
Joe Thornbereb2aa482012-03-28 18:41:28 +01001368 map_context->ptr = thin_hook_bio(tc, bio);
Joe Thornbere49e5822012-07-27 15:08:16 +01001369
1370 if (get_pool_mode(tc->pool) == PM_FAIL) {
1371 bio_io_error(bio);
1372 return DM_MAPIO_SUBMITTED;
1373 }
1374
Joe Thornber104655f2012-03-28 18:41:28 +01001375 if (bio->bi_rw & (REQ_DISCARD | REQ_FLUSH | REQ_FUA)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001376 thin_defer_bio(tc, bio);
1377 return DM_MAPIO_SUBMITTED;
1378 }
1379
1380 r = dm_thin_find_block(td, block, 0, &result);
1381
1382 /*
1383 * Note that we defer readahead too.
1384 */
1385 switch (r) {
1386 case 0:
1387 if (unlikely(result.shared)) {
1388 /*
1389 * We have a race condition here between the
1390 * result.shared value returned by the lookup and
1391 * snapshot creation, which may cause new
1392 * sharing.
1393 *
1394 * To avoid this always quiesce the origin before
1395 * taking the snap. You want to do this anyway to
1396 * ensure a consistent application view
1397 * (i.e. lockfs).
1398 *
1399 * More distant ancestors are irrelevant. The
1400 * shared flag will be set in their case.
1401 */
1402 thin_defer_bio(tc, bio);
1403 r = DM_MAPIO_SUBMITTED;
1404 } else {
1405 remap(tc, bio, result.block);
1406 r = DM_MAPIO_REMAPPED;
1407 }
1408 break;
1409
1410 case -ENODATA:
Joe Thornbere49e5822012-07-27 15:08:16 +01001411 if (get_pool_mode(tc->pool) == PM_READ_ONLY) {
1412 /*
1413 * This block isn't provisioned, and we have no way
1414 * of doing so. Just error it.
1415 */
1416 bio_io_error(bio);
1417 r = DM_MAPIO_SUBMITTED;
1418 break;
1419 }
1420 /* fall through */
1421
1422 case -EWOULDBLOCK:
Joe Thornber991d9fa2011-10-31 20:21:18 +00001423 /*
1424 * In future, the failed dm_thin_find_block above could
1425 * provide the hint to load the metadata into cache.
1426 */
Joe Thornber991d9fa2011-10-31 20:21:18 +00001427 thin_defer_bio(tc, bio);
1428 r = DM_MAPIO_SUBMITTED;
1429 break;
Joe Thornbere49e5822012-07-27 15:08:16 +01001430
1431 default:
1432 /*
1433 * Must always call bio_io_error on failure.
1434 * dm_thin_find_block can fail with -EINVAL if the
1435 * pool is switched to fail-io mode.
1436 */
1437 bio_io_error(bio);
1438 r = DM_MAPIO_SUBMITTED;
1439 break;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001440 }
1441
1442 return r;
1443}
1444
1445static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
1446{
1447 int r;
1448 unsigned long flags;
1449 struct pool_c *pt = container_of(cb, struct pool_c, callbacks);
1450
1451 spin_lock_irqsave(&pt->pool->lock, flags);
1452 r = !bio_list_empty(&pt->pool->retry_on_resume_list);
1453 spin_unlock_irqrestore(&pt->pool->lock, flags);
1454
1455 if (!r) {
1456 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
1457 r = bdi_congested(&q->backing_dev_info, bdi_bits);
1458 }
1459
1460 return r;
1461}
1462
1463static void __requeue_bios(struct pool *pool)
1464{
1465 bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list);
1466 bio_list_init(&pool->retry_on_resume_list);
1467}
1468
1469/*----------------------------------------------------------------
1470 * Binding of control targets to a pool object
1471 *--------------------------------------------------------------*/
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001472static bool data_dev_supports_discard(struct pool_c *pt)
1473{
1474 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
1475
1476 return q && blk_queue_discard(q);
1477}
1478
1479/*
1480 * If discard_passdown was enabled verify that the data device
Mike Snitzer0424caa2012-09-26 23:45:47 +01001481 * supports discards. Disable discard_passdown if not.
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001482 */
Mike Snitzer0424caa2012-09-26 23:45:47 +01001483static void disable_passdown_if_not_supported(struct pool_c *pt)
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001484{
Mike Snitzer0424caa2012-09-26 23:45:47 +01001485 struct pool *pool = pt->pool;
1486 struct block_device *data_bdev = pt->data_dev->bdev;
1487 struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits;
1488 sector_t block_size = pool->sectors_per_block << SECTOR_SHIFT;
1489 const char *reason = NULL;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001490 char buf[BDEVNAME_SIZE];
1491
Mike Snitzer0424caa2012-09-26 23:45:47 +01001492 if (!pt->adjusted_pf.discard_passdown)
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001493 return;
1494
Mike Snitzer0424caa2012-09-26 23:45:47 +01001495 if (!data_dev_supports_discard(pt))
1496 reason = "discard unsupported";
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001497
Mike Snitzer0424caa2012-09-26 23:45:47 +01001498 else if (data_limits->max_discard_sectors < pool->sectors_per_block)
1499 reason = "max discard sectors smaller than a block";
1500
1501 else if (data_limits->discard_granularity > block_size)
1502 reason = "discard granularity larger than a block";
1503
1504 else if (block_size & (data_limits->discard_granularity - 1))
1505 reason = "discard granularity not a factor of block size";
1506
1507 if (reason) {
1508 DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev, buf), reason);
1509 pt->adjusted_pf.discard_passdown = false;
1510 }
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001511}
1512
Joe Thornber991d9fa2011-10-31 20:21:18 +00001513static int bind_control_target(struct pool *pool, struct dm_target *ti)
1514{
1515 struct pool_c *pt = ti->private;
1516
Joe Thornbere49e5822012-07-27 15:08:16 +01001517 /*
1518 * We want to make sure that degraded pools are never upgraded.
1519 */
1520 enum pool_mode old_mode = pool->pf.mode;
Mike Snitzer0424caa2012-09-26 23:45:47 +01001521 enum pool_mode new_mode = pt->adjusted_pf.mode;
Joe Thornbere49e5822012-07-27 15:08:16 +01001522
1523 if (old_mode > new_mode)
1524 new_mode = old_mode;
1525
Joe Thornber991d9fa2011-10-31 20:21:18 +00001526 pool->ti = ti;
1527 pool->low_water_blocks = pt->low_water_blocks;
Mike Snitzer0424caa2012-09-26 23:45:47 +01001528 pool->pf = pt->adjusted_pf;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001529
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001530 set_pool_mode(pool, new_mode);
Mike Snitzerf4026932012-05-19 01:01:01 +01001531
Joe Thornber991d9fa2011-10-31 20:21:18 +00001532 return 0;
1533}
1534
1535static void unbind_control_target(struct pool *pool, struct dm_target *ti)
1536{
1537 if (pool->ti == ti)
1538 pool->ti = NULL;
1539}
1540
1541/*----------------------------------------------------------------
1542 * Pool creation
1543 *--------------------------------------------------------------*/
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001544/* Initialize pool features. */
1545static void pool_features_init(struct pool_features *pf)
1546{
Joe Thornbere49e5822012-07-27 15:08:16 +01001547 pf->mode = PM_WRITE;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001548 pf->zero_new_blocks = true;
1549 pf->discard_enabled = true;
1550 pf->discard_passdown = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001551}
1552
Joe Thornber991d9fa2011-10-31 20:21:18 +00001553static void __pool_destroy(struct pool *pool)
1554{
1555 __pool_table_remove(pool);
1556
1557 if (dm_pool_metadata_close(pool->pmd) < 0)
1558 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
1559
Mike Snitzer44feb382012-10-12 21:02:10 +01001560 dm_bio_prison_destroy(pool->prison);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001561 dm_kcopyd_client_destroy(pool->copier);
1562
1563 if (pool->wq)
1564 destroy_workqueue(pool->wq);
1565
1566 if (pool->next_mapping)
1567 mempool_free(pool->next_mapping, pool->mapping_pool);
1568 mempool_destroy(pool->mapping_pool);
1569 mempool_destroy(pool->endio_hook_pool);
Mike Snitzer44feb382012-10-12 21:02:10 +01001570 dm_deferred_set_destroy(pool->shared_read_ds);
1571 dm_deferred_set_destroy(pool->all_io_ds);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001572 kfree(pool);
1573}
1574
Mike Snitzera24c2562012-06-03 00:30:00 +01001575static struct kmem_cache *_new_mapping_cache;
1576static struct kmem_cache *_endio_hook_cache;
1577
Joe Thornber991d9fa2011-10-31 20:21:18 +00001578static struct pool *pool_create(struct mapped_device *pool_md,
1579 struct block_device *metadata_dev,
Joe Thornbere49e5822012-07-27 15:08:16 +01001580 unsigned long block_size,
1581 int read_only, char **error)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001582{
1583 int r;
1584 void *err_p;
1585 struct pool *pool;
1586 struct dm_pool_metadata *pmd;
Joe Thornbere49e5822012-07-27 15:08:16 +01001587 bool format_device = read_only ? false : true;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001588
Joe Thornbere49e5822012-07-27 15:08:16 +01001589 pmd = dm_pool_metadata_open(metadata_dev, block_size, format_device);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001590 if (IS_ERR(pmd)) {
1591 *error = "Error creating metadata object";
1592 return (struct pool *)pmd;
1593 }
1594
1595 pool = kmalloc(sizeof(*pool), GFP_KERNEL);
1596 if (!pool) {
1597 *error = "Error allocating memory for pool";
1598 err_p = ERR_PTR(-ENOMEM);
1599 goto bad_pool;
1600 }
1601
1602 pool->pmd = pmd;
1603 pool->sectors_per_block = block_size;
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +01001604 if (block_size & (block_size - 1))
1605 pool->sectors_per_block_shift = -1;
1606 else
1607 pool->sectors_per_block_shift = __ffs(block_size);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001608 pool->low_water_blocks = 0;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001609 pool_features_init(&pool->pf);
Mike Snitzer44feb382012-10-12 21:02:10 +01001610 pool->prison = dm_bio_prison_create(PRISON_CELLS);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001611 if (!pool->prison) {
1612 *error = "Error creating pool's bio prison";
1613 err_p = ERR_PTR(-ENOMEM);
1614 goto bad_prison;
1615 }
1616
1617 pool->copier = dm_kcopyd_client_create();
1618 if (IS_ERR(pool->copier)) {
1619 r = PTR_ERR(pool->copier);
1620 *error = "Error creating pool's kcopyd client";
1621 err_p = ERR_PTR(r);
1622 goto bad_kcopyd_client;
1623 }
1624
1625 /*
1626 * Create singlethreaded workqueue that will service all devices
1627 * that use this metadata.
1628 */
1629 pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
1630 if (!pool->wq) {
1631 *error = "Error creating pool's workqueue";
1632 err_p = ERR_PTR(-ENOMEM);
1633 goto bad_wq;
1634 }
1635
1636 INIT_WORK(&pool->worker, do_worker);
Joe Thornber905e51b2012-03-28 18:41:27 +01001637 INIT_DELAYED_WORK(&pool->waker, do_waker);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001638 spin_lock_init(&pool->lock);
1639 bio_list_init(&pool->deferred_bios);
1640 bio_list_init(&pool->deferred_flush_bios);
1641 INIT_LIST_HEAD(&pool->prepared_mappings);
Joe Thornber104655f2012-03-28 18:41:28 +01001642 INIT_LIST_HEAD(&pool->prepared_discards);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001643 pool->low_water_triggered = 0;
1644 pool->no_free_space = 0;
1645 bio_list_init(&pool->retry_on_resume_list);
Mike Snitzer44feb382012-10-12 21:02:10 +01001646
1647 pool->shared_read_ds = dm_deferred_set_create();
1648 if (!pool->shared_read_ds) {
1649 *error = "Error creating pool's shared read deferred set";
1650 err_p = ERR_PTR(-ENOMEM);
1651 goto bad_shared_read_ds;
1652 }
1653
1654 pool->all_io_ds = dm_deferred_set_create();
1655 if (!pool->all_io_ds) {
1656 *error = "Error creating pool's all io deferred set";
1657 err_p = ERR_PTR(-ENOMEM);
1658 goto bad_all_io_ds;
1659 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001660
1661 pool->next_mapping = NULL;
Mike Snitzera24c2562012-06-03 00:30:00 +01001662 pool->mapping_pool = mempool_create_slab_pool(MAPPING_POOL_SIZE,
1663 _new_mapping_cache);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001664 if (!pool->mapping_pool) {
1665 *error = "Error creating pool's mapping mempool";
1666 err_p = ERR_PTR(-ENOMEM);
1667 goto bad_mapping_pool;
1668 }
1669
Mike Snitzera24c2562012-06-03 00:30:00 +01001670 pool->endio_hook_pool = mempool_create_slab_pool(ENDIO_HOOK_POOL_SIZE,
1671 _endio_hook_cache);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001672 if (!pool->endio_hook_pool) {
1673 *error = "Error creating pool's endio_hook mempool";
1674 err_p = ERR_PTR(-ENOMEM);
1675 goto bad_endio_hook_pool;
1676 }
1677 pool->ref_count = 1;
Joe Thornber905e51b2012-03-28 18:41:27 +01001678 pool->last_commit_jiffies = jiffies;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001679 pool->pool_md = pool_md;
1680 pool->md_dev = metadata_dev;
1681 __pool_table_insert(pool);
1682
1683 return pool;
1684
1685bad_endio_hook_pool:
1686 mempool_destroy(pool->mapping_pool);
1687bad_mapping_pool:
Mike Snitzer44feb382012-10-12 21:02:10 +01001688 dm_deferred_set_destroy(pool->all_io_ds);
1689bad_all_io_ds:
1690 dm_deferred_set_destroy(pool->shared_read_ds);
1691bad_shared_read_ds:
Joe Thornber991d9fa2011-10-31 20:21:18 +00001692 destroy_workqueue(pool->wq);
1693bad_wq:
1694 dm_kcopyd_client_destroy(pool->copier);
1695bad_kcopyd_client:
Mike Snitzer44feb382012-10-12 21:02:10 +01001696 dm_bio_prison_destroy(pool->prison);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001697bad_prison:
1698 kfree(pool);
1699bad_pool:
1700 if (dm_pool_metadata_close(pmd))
1701 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
1702
1703 return err_p;
1704}
1705
1706static void __pool_inc(struct pool *pool)
1707{
1708 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
1709 pool->ref_count++;
1710}
1711
1712static void __pool_dec(struct pool *pool)
1713{
1714 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
1715 BUG_ON(!pool->ref_count);
1716 if (!--pool->ref_count)
1717 __pool_destroy(pool);
1718}
1719
1720static struct pool *__pool_find(struct mapped_device *pool_md,
1721 struct block_device *metadata_dev,
Joe Thornbere49e5822012-07-27 15:08:16 +01001722 unsigned long block_size, int read_only,
1723 char **error, int *created)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001724{
1725 struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev);
1726
1727 if (pool) {
Mike Snitzerf09996c2012-07-27 15:07:59 +01001728 if (pool->pool_md != pool_md) {
1729 *error = "metadata device already in use by a pool";
Joe Thornber991d9fa2011-10-31 20:21:18 +00001730 return ERR_PTR(-EBUSY);
Mike Snitzerf09996c2012-07-27 15:07:59 +01001731 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001732 __pool_inc(pool);
1733
1734 } else {
1735 pool = __pool_table_lookup(pool_md);
1736 if (pool) {
Mike Snitzerf09996c2012-07-27 15:07:59 +01001737 if (pool->md_dev != metadata_dev) {
1738 *error = "different pool cannot replace a pool";
Joe Thornber991d9fa2011-10-31 20:21:18 +00001739 return ERR_PTR(-EINVAL);
Mike Snitzerf09996c2012-07-27 15:07:59 +01001740 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001741 __pool_inc(pool);
1742
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001743 } else {
Joe Thornbere49e5822012-07-27 15:08:16 +01001744 pool = pool_create(pool_md, metadata_dev, block_size, read_only, error);
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001745 *created = 1;
1746 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001747 }
1748
1749 return pool;
1750}
1751
1752/*----------------------------------------------------------------
1753 * Pool target methods
1754 *--------------------------------------------------------------*/
1755static void pool_dtr(struct dm_target *ti)
1756{
1757 struct pool_c *pt = ti->private;
1758
1759 mutex_lock(&dm_thin_pool_table.mutex);
1760
1761 unbind_control_target(pt->pool, ti);
1762 __pool_dec(pt->pool);
1763 dm_put_device(ti, pt->metadata_dev);
1764 dm_put_device(ti, pt->data_dev);
1765 kfree(pt);
1766
1767 mutex_unlock(&dm_thin_pool_table.mutex);
1768}
1769
Joe Thornber991d9fa2011-10-31 20:21:18 +00001770static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf,
1771 struct dm_target *ti)
1772{
1773 int r;
1774 unsigned argc;
1775 const char *arg_name;
1776
1777 static struct dm_arg _args[] = {
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001778 {0, 3, "Invalid number of pool feature arguments"},
Joe Thornber991d9fa2011-10-31 20:21:18 +00001779 };
1780
1781 /*
1782 * No feature arguments supplied.
1783 */
1784 if (!as->argc)
1785 return 0;
1786
1787 r = dm_read_arg_group(_args, as, &argc, &ti->error);
1788 if (r)
1789 return -EINVAL;
1790
1791 while (argc && !r) {
1792 arg_name = dm_shift_arg(as);
1793 argc--;
1794
Joe Thornbere49e5822012-07-27 15:08:16 +01001795 if (!strcasecmp(arg_name, "skip_block_zeroing"))
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001796 pf->zero_new_blocks = false;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001797
Joe Thornbere49e5822012-07-27 15:08:16 +01001798 else if (!strcasecmp(arg_name, "ignore_discard"))
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001799 pf->discard_enabled = false;
Joe Thornbere49e5822012-07-27 15:08:16 +01001800
1801 else if (!strcasecmp(arg_name, "no_discard_passdown"))
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001802 pf->discard_passdown = false;
Joe Thornbere49e5822012-07-27 15:08:16 +01001803
1804 else if (!strcasecmp(arg_name, "read_only"))
1805 pf->mode = PM_READ_ONLY;
1806
1807 else {
1808 ti->error = "Unrecognised pool feature requested";
1809 r = -EINVAL;
1810 break;
1811 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001812 }
1813
1814 return r;
1815}
1816
1817/*
1818 * thin-pool <metadata dev> <data dev>
1819 * <data block size (sectors)>
1820 * <low water mark (blocks)>
1821 * [<#feature args> [<arg>]*]
1822 *
1823 * Optional feature arguments are:
1824 * skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001825 * ignore_discard: disable discard
1826 * no_discard_passdown: don't pass discards down to the data device
Joe Thornber991d9fa2011-10-31 20:21:18 +00001827 */
1828static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv)
1829{
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001830 int r, pool_created = 0;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001831 struct pool_c *pt;
1832 struct pool *pool;
1833 struct pool_features pf;
1834 struct dm_arg_set as;
1835 struct dm_dev *data_dev;
1836 unsigned long block_size;
1837 dm_block_t low_water_blocks;
1838 struct dm_dev *metadata_dev;
1839 sector_t metadata_dev_size;
Mike Snitzerc4a69ec2012-03-28 18:41:28 +01001840 char b[BDEVNAME_SIZE];
Joe Thornber991d9fa2011-10-31 20:21:18 +00001841
1842 /*
1843 * FIXME Remove validation from scope of lock.
1844 */
1845 mutex_lock(&dm_thin_pool_table.mutex);
1846
1847 if (argc < 4) {
1848 ti->error = "Invalid argument count";
1849 r = -EINVAL;
1850 goto out_unlock;
1851 }
1852 as.argc = argc;
1853 as.argv = argv;
1854
1855 r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &metadata_dev);
1856 if (r) {
1857 ti->error = "Error opening metadata block device";
1858 goto out_unlock;
1859 }
1860
1861 metadata_dev_size = i_size_read(metadata_dev->bdev->bd_inode) >> SECTOR_SHIFT;
Mike Snitzerc4a69ec2012-03-28 18:41:28 +01001862 if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING)
1863 DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",
1864 bdevname(metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001865
1866 r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev);
1867 if (r) {
1868 ti->error = "Error getting data device";
1869 goto out_metadata;
1870 }
1871
1872 if (kstrtoul(argv[2], 10, &block_size) || !block_size ||
1873 block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
1874 block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01001875 block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001876 ti->error = "Invalid block size";
1877 r = -EINVAL;
1878 goto out;
1879 }
1880
1881 if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) {
1882 ti->error = "Invalid low water mark";
1883 r = -EINVAL;
1884 goto out;
1885 }
1886
1887 /*
1888 * Set default pool features.
1889 */
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001890 pool_features_init(&pf);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001891
1892 dm_consume_args(&as, 4);
1893 r = parse_pool_features(&as, &pf, ti);
1894 if (r)
1895 goto out;
1896
1897 pt = kzalloc(sizeof(*pt), GFP_KERNEL);
1898 if (!pt) {
1899 r = -ENOMEM;
1900 goto out;
1901 }
1902
1903 pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev,
Joe Thornbere49e5822012-07-27 15:08:16 +01001904 block_size, pf.mode == PM_READ_ONLY, &ti->error, &pool_created);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001905 if (IS_ERR(pool)) {
1906 r = PTR_ERR(pool);
1907 goto out_free_pt;
1908 }
1909
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001910 /*
1911 * 'pool_created' reflects whether this is the first table load.
1912 * Top level discard support is not allowed to be changed after
1913 * initial load. This would require a pool reload to trigger thin
1914 * device changes.
1915 */
1916 if (!pool_created && pf.discard_enabled != pool->pf.discard_enabled) {
1917 ti->error = "Discard support cannot be disabled once enabled";
1918 r = -EINVAL;
1919 goto out_flags_changed;
1920 }
1921
Joe Thornber991d9fa2011-10-31 20:21:18 +00001922 pt->pool = pool;
1923 pt->ti = ti;
1924 pt->metadata_dev = metadata_dev;
1925 pt->data_dev = data_dev;
1926 pt->low_water_blocks = low_water_blocks;
Mike Snitzer0424caa2012-09-26 23:45:47 +01001927 pt->adjusted_pf = pt->requested_pf = pf;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001928 ti->num_flush_requests = 1;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001929
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001930 /*
1931 * Only need to enable discards if the pool should pass
1932 * them down to the data device. The thin device's discard
1933 * processing will cause mappings to be removed from the btree.
1934 */
1935 if (pf.discard_enabled && pf.discard_passdown) {
1936 ti->num_discard_requests = 1;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001937
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001938 /*
1939 * Setting 'discards_supported' circumvents the normal
1940 * stacking of discard limits (this keeps the pool and
1941 * thin devices' discard limits consistent).
1942 */
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01001943 ti->discards_supported = true;
Mike Snitzer307615a2012-09-26 23:45:39 +01001944 ti->discard_zeroes_data_unsupported = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001945 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001946 ti->private = pt;
1947
1948 pt->callbacks.congested_fn = pool_is_congested;
1949 dm_table_add_target_callbacks(ti->table, &pt->callbacks);
1950
1951 mutex_unlock(&dm_thin_pool_table.mutex);
1952
1953 return 0;
1954
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001955out_flags_changed:
1956 __pool_dec(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001957out_free_pt:
1958 kfree(pt);
1959out:
1960 dm_put_device(ti, data_dev);
1961out_metadata:
1962 dm_put_device(ti, metadata_dev);
1963out_unlock:
1964 mutex_unlock(&dm_thin_pool_table.mutex);
1965
1966 return r;
1967}
1968
1969static int pool_map(struct dm_target *ti, struct bio *bio,
1970 union map_info *map_context)
1971{
1972 int r;
1973 struct pool_c *pt = ti->private;
1974 struct pool *pool = pt->pool;
1975 unsigned long flags;
1976
1977 /*
1978 * As this is a singleton target, ti->begin is always zero.
1979 */
1980 spin_lock_irqsave(&pool->lock, flags);
1981 bio->bi_bdev = pt->data_dev->bdev;
1982 r = DM_MAPIO_REMAPPED;
1983 spin_unlock_irqrestore(&pool->lock, flags);
1984
1985 return r;
1986}
1987
1988/*
1989 * Retrieves the number of blocks of the data device from
1990 * the superblock and compares it to the actual device size,
1991 * thus resizing the data device in case it has grown.
1992 *
1993 * This both copes with opening preallocated data devices in the ctr
1994 * being followed by a resume
1995 * -and-
1996 * calling the resume method individually after userspace has
1997 * grown the data device in reaction to a table event.
1998 */
1999static int pool_preresume(struct dm_target *ti)
2000{
2001 int r;
2002 struct pool_c *pt = ti->private;
2003 struct pool *pool = pt->pool;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002004 sector_t data_size = ti->len;
2005 dm_block_t sb_data_size;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002006
2007 /*
2008 * Take control of the pool object.
2009 */
2010 r = bind_control_target(pool, ti);
2011 if (r)
2012 return r;
2013
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002014 (void) sector_div(data_size, pool->sectors_per_block);
2015
Joe Thornber991d9fa2011-10-31 20:21:18 +00002016 r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
2017 if (r) {
2018 DMERR("failed to retrieve data device size");
2019 return r;
2020 }
2021
2022 if (data_size < sb_data_size) {
2023 DMERR("pool target too small, is %llu blocks (expected %llu)",
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002024 (unsigned long long)data_size, sb_data_size);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002025 return -EINVAL;
2026
2027 } else if (data_size > sb_data_size) {
2028 r = dm_pool_resize_data_dev(pool->pmd, data_size);
2029 if (r) {
2030 DMERR("failed to resize data device");
Joe Thornbere49e5822012-07-27 15:08:16 +01002031 /* FIXME Stricter than necessary: Rollback transaction instead here */
2032 set_pool_mode(pool, PM_READ_ONLY);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002033 return r;
2034 }
2035
Joe Thornbere49e5822012-07-27 15:08:16 +01002036 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002037 }
2038
2039 return 0;
2040}
2041
2042static void pool_resume(struct dm_target *ti)
2043{
2044 struct pool_c *pt = ti->private;
2045 struct pool *pool = pt->pool;
2046 unsigned long flags;
2047
2048 spin_lock_irqsave(&pool->lock, flags);
2049 pool->low_water_triggered = 0;
2050 pool->no_free_space = 0;
2051 __requeue_bios(pool);
2052 spin_unlock_irqrestore(&pool->lock, flags);
2053
Joe Thornber905e51b2012-03-28 18:41:27 +01002054 do_waker(&pool->waker.work);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002055}
2056
2057static void pool_postsuspend(struct dm_target *ti)
2058{
Joe Thornber991d9fa2011-10-31 20:21:18 +00002059 struct pool_c *pt = ti->private;
2060 struct pool *pool = pt->pool;
2061
Joe Thornber905e51b2012-03-28 18:41:27 +01002062 cancel_delayed_work(&pool->waker);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002063 flush_workqueue(pool->wq);
Joe Thornbere49e5822012-07-27 15:08:16 +01002064 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002065}
2066
2067static int check_arg_count(unsigned argc, unsigned args_required)
2068{
2069 if (argc != args_required) {
2070 DMWARN("Message received with %u arguments instead of %u.",
2071 argc, args_required);
2072 return -EINVAL;
2073 }
2074
2075 return 0;
2076}
2077
2078static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning)
2079{
2080 if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) &&
2081 *dev_id <= MAX_DEV_ID)
2082 return 0;
2083
2084 if (warning)
2085 DMWARN("Message received with invalid device id: %s", arg);
2086
2087 return -EINVAL;
2088}
2089
2090static int process_create_thin_mesg(unsigned argc, char **argv, struct pool *pool)
2091{
2092 dm_thin_id dev_id;
2093 int r;
2094
2095 r = check_arg_count(argc, 2);
2096 if (r)
2097 return r;
2098
2099 r = read_dev_id(argv[1], &dev_id, 1);
2100 if (r)
2101 return r;
2102
2103 r = dm_pool_create_thin(pool->pmd, dev_id);
2104 if (r) {
2105 DMWARN("Creation of new thinly-provisioned device with id %s failed.",
2106 argv[1]);
2107 return r;
2108 }
2109
2110 return 0;
2111}
2112
2113static int process_create_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2114{
2115 dm_thin_id dev_id;
2116 dm_thin_id origin_dev_id;
2117 int r;
2118
2119 r = check_arg_count(argc, 3);
2120 if (r)
2121 return r;
2122
2123 r = read_dev_id(argv[1], &dev_id, 1);
2124 if (r)
2125 return r;
2126
2127 r = read_dev_id(argv[2], &origin_dev_id, 1);
2128 if (r)
2129 return r;
2130
2131 r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id);
2132 if (r) {
2133 DMWARN("Creation of new snapshot %s of device %s failed.",
2134 argv[1], argv[2]);
2135 return r;
2136 }
2137
2138 return 0;
2139}
2140
2141static int process_delete_mesg(unsigned argc, char **argv, struct pool *pool)
2142{
2143 dm_thin_id dev_id;
2144 int r;
2145
2146 r = check_arg_count(argc, 2);
2147 if (r)
2148 return r;
2149
2150 r = read_dev_id(argv[1], &dev_id, 1);
2151 if (r)
2152 return r;
2153
2154 r = dm_pool_delete_thin_device(pool->pmd, dev_id);
2155 if (r)
2156 DMWARN("Deletion of thin device %s failed.", argv[1]);
2157
2158 return r;
2159}
2160
2161static int process_set_transaction_id_mesg(unsigned argc, char **argv, struct pool *pool)
2162{
2163 dm_thin_id old_id, new_id;
2164 int r;
2165
2166 r = check_arg_count(argc, 3);
2167 if (r)
2168 return r;
2169
2170 if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) {
2171 DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]);
2172 return -EINVAL;
2173 }
2174
2175 if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) {
2176 DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]);
2177 return -EINVAL;
2178 }
2179
2180 r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id);
2181 if (r) {
2182 DMWARN("Failed to change transaction id from %s to %s.",
2183 argv[1], argv[2]);
2184 return r;
2185 }
2186
2187 return 0;
2188}
2189
Joe Thornbercc8394d2012-06-03 00:30:01 +01002190static int process_reserve_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2191{
2192 int r;
2193
2194 r = check_arg_count(argc, 1);
2195 if (r)
2196 return r;
2197
Joe Thornbere49e5822012-07-27 15:08:16 +01002198 (void) commit_or_fallback(pool);
Joe Thornber0d200ae2012-07-03 12:55:31 +01002199
Joe Thornbercc8394d2012-06-03 00:30:01 +01002200 r = dm_pool_reserve_metadata_snap(pool->pmd);
2201 if (r)
2202 DMWARN("reserve_metadata_snap message failed.");
2203
2204 return r;
2205}
2206
2207static int process_release_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2208{
2209 int r;
2210
2211 r = check_arg_count(argc, 1);
2212 if (r)
2213 return r;
2214
2215 r = dm_pool_release_metadata_snap(pool->pmd);
2216 if (r)
2217 DMWARN("release_metadata_snap message failed.");
2218
2219 return r;
2220}
2221
Joe Thornber991d9fa2011-10-31 20:21:18 +00002222/*
2223 * Messages supported:
2224 * create_thin <dev_id>
2225 * create_snap <dev_id> <origin_id>
2226 * delete <dev_id>
2227 * trim <dev_id> <new_size_in_sectors>
2228 * set_transaction_id <current_trans_id> <new_trans_id>
Joe Thornbercc8394d2012-06-03 00:30:01 +01002229 * reserve_metadata_snap
2230 * release_metadata_snap
Joe Thornber991d9fa2011-10-31 20:21:18 +00002231 */
2232static int pool_message(struct dm_target *ti, unsigned argc, char **argv)
2233{
2234 int r = -EINVAL;
2235 struct pool_c *pt = ti->private;
2236 struct pool *pool = pt->pool;
2237
2238 if (!strcasecmp(argv[0], "create_thin"))
2239 r = process_create_thin_mesg(argc, argv, pool);
2240
2241 else if (!strcasecmp(argv[0], "create_snap"))
2242 r = process_create_snap_mesg(argc, argv, pool);
2243
2244 else if (!strcasecmp(argv[0], "delete"))
2245 r = process_delete_mesg(argc, argv, pool);
2246
2247 else if (!strcasecmp(argv[0], "set_transaction_id"))
2248 r = process_set_transaction_id_mesg(argc, argv, pool);
2249
Joe Thornbercc8394d2012-06-03 00:30:01 +01002250 else if (!strcasecmp(argv[0], "reserve_metadata_snap"))
2251 r = process_reserve_metadata_snap_mesg(argc, argv, pool);
2252
2253 else if (!strcasecmp(argv[0], "release_metadata_snap"))
2254 r = process_release_metadata_snap_mesg(argc, argv, pool);
2255
Joe Thornber991d9fa2011-10-31 20:21:18 +00002256 else
2257 DMWARN("Unrecognised thin pool target message received: %s", argv[0]);
2258
Joe Thornbere49e5822012-07-27 15:08:16 +01002259 if (!r)
2260 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002261
2262 return r;
2263}
2264
Joe Thornbere49e5822012-07-27 15:08:16 +01002265static void emit_flags(struct pool_features *pf, char *result,
2266 unsigned sz, unsigned maxlen)
2267{
2268 unsigned count = !pf->zero_new_blocks + !pf->discard_enabled +
2269 !pf->discard_passdown + (pf->mode == PM_READ_ONLY);
2270 DMEMIT("%u ", count);
2271
2272 if (!pf->zero_new_blocks)
2273 DMEMIT("skip_block_zeroing ");
2274
2275 if (!pf->discard_enabled)
2276 DMEMIT("ignore_discard ");
2277
2278 if (!pf->discard_passdown)
2279 DMEMIT("no_discard_passdown ");
2280
2281 if (pf->mode == PM_READ_ONLY)
2282 DMEMIT("read_only ");
2283}
2284
Joe Thornber991d9fa2011-10-31 20:21:18 +00002285/*
2286 * Status line is:
2287 * <transaction id> <used metadata sectors>/<total metadata sectors>
2288 * <used data sectors>/<total data sectors> <held metadata root>
2289 */
2290static int pool_status(struct dm_target *ti, status_type_t type,
Alasdair G Kergon1f4e0ff2012-07-27 15:08:16 +01002291 unsigned status_flags, char *result, unsigned maxlen)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002292{
Joe Thornbere49e5822012-07-27 15:08:16 +01002293 int r;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002294 unsigned sz = 0;
2295 uint64_t transaction_id;
2296 dm_block_t nr_free_blocks_data;
2297 dm_block_t nr_free_blocks_metadata;
2298 dm_block_t nr_blocks_data;
2299 dm_block_t nr_blocks_metadata;
2300 dm_block_t held_root;
2301 char buf[BDEVNAME_SIZE];
2302 char buf2[BDEVNAME_SIZE];
2303 struct pool_c *pt = ti->private;
2304 struct pool *pool = pt->pool;
2305
2306 switch (type) {
2307 case STATUSTYPE_INFO:
Joe Thornbere49e5822012-07-27 15:08:16 +01002308 if (get_pool_mode(pool) == PM_FAIL) {
2309 DMEMIT("Fail");
2310 break;
2311 }
2312
Alasdair G Kergon1f4e0ff2012-07-27 15:08:16 +01002313 /* Commit to ensure statistics aren't out-of-date */
2314 if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
2315 (void) commit_or_fallback(pool);
2316
Joe Thornber991d9fa2011-10-31 20:21:18 +00002317 r = dm_pool_get_metadata_transaction_id(pool->pmd,
2318 &transaction_id);
2319 if (r)
2320 return r;
2321
2322 r = dm_pool_get_free_metadata_block_count(pool->pmd,
2323 &nr_free_blocks_metadata);
2324 if (r)
2325 return r;
2326
2327 r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
2328 if (r)
2329 return r;
2330
2331 r = dm_pool_get_free_block_count(pool->pmd,
2332 &nr_free_blocks_data);
2333 if (r)
2334 return r;
2335
2336 r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
2337 if (r)
2338 return r;
2339
Joe Thornbercc8394d2012-06-03 00:30:01 +01002340 r = dm_pool_get_metadata_snap(pool->pmd, &held_root);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002341 if (r)
2342 return r;
2343
2344 DMEMIT("%llu %llu/%llu %llu/%llu ",
2345 (unsigned long long)transaction_id,
2346 (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata),
2347 (unsigned long long)nr_blocks_metadata,
2348 (unsigned long long)(nr_blocks_data - nr_free_blocks_data),
2349 (unsigned long long)nr_blocks_data);
2350
2351 if (held_root)
Joe Thornbere49e5822012-07-27 15:08:16 +01002352 DMEMIT("%llu ", held_root);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002353 else
Joe Thornbere49e5822012-07-27 15:08:16 +01002354 DMEMIT("- ");
2355
2356 if (pool->pf.mode == PM_READ_ONLY)
2357 DMEMIT("ro ");
2358 else
2359 DMEMIT("rw ");
2360
2361 if (pool->pf.discard_enabled && pool->pf.discard_passdown)
2362 DMEMIT("discard_passdown");
2363 else
2364 DMEMIT("no_discard_passdown");
Joe Thornber991d9fa2011-10-31 20:21:18 +00002365
2366 break;
2367
2368 case STATUSTYPE_TABLE:
2369 DMEMIT("%s %s %lu %llu ",
2370 format_dev_t(buf, pt->metadata_dev->bdev->bd_dev),
2371 format_dev_t(buf2, pt->data_dev->bdev->bd_dev),
2372 (unsigned long)pool->sectors_per_block,
2373 (unsigned long long)pt->low_water_blocks);
Mike Snitzer0424caa2012-09-26 23:45:47 +01002374 emit_flags(&pt->requested_pf, result, sz, maxlen);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002375 break;
2376 }
2377
2378 return 0;
2379}
2380
2381static int pool_iterate_devices(struct dm_target *ti,
2382 iterate_devices_callout_fn fn, void *data)
2383{
2384 struct pool_c *pt = ti->private;
2385
2386 return fn(ti, pt->data_dev, 0, ti->len, data);
2387}
2388
2389static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
2390 struct bio_vec *biovec, int max_size)
2391{
2392 struct pool_c *pt = ti->private;
2393 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
2394
2395 if (!q->merge_bvec_fn)
2396 return max_size;
2397
2398 bvm->bi_bdev = pt->data_dev->bdev;
2399
2400 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
2401}
2402
Mike Snitzer28eed342012-10-12 21:02:07 +01002403static bool block_size_is_power_of_two(struct pool *pool)
2404{
2405 return pool->sectors_per_block_shift >= 0;
2406}
2407
Mike Snitzer0424caa2012-09-26 23:45:47 +01002408static void set_discard_limits(struct pool_c *pt, struct queue_limits *limits)
Joe Thornber104655f2012-03-28 18:41:28 +01002409{
Mike Snitzer0424caa2012-09-26 23:45:47 +01002410 struct pool *pool = pt->pool;
2411 struct queue_limits *data_limits;
2412
Joe Thornber104655f2012-03-28 18:41:28 +01002413 limits->max_discard_sectors = pool->sectors_per_block;
2414
2415 /*
Mike Snitzer0424caa2012-09-26 23:45:47 +01002416 * discard_granularity is just a hint, and not enforced.
Joe Thornber104655f2012-03-28 18:41:28 +01002417 */
Mike Snitzer0424caa2012-09-26 23:45:47 +01002418 if (pt->adjusted_pf.discard_passdown) {
2419 data_limits = &bdev_get_queue(pt->data_dev->bdev)->limits;
2420 limits->discard_granularity = data_limits->discard_granularity;
Mike Snitzer28eed342012-10-12 21:02:07 +01002421 } else if (block_size_is_power_of_two(pool))
Mike Snitzer0424caa2012-09-26 23:45:47 +01002422 limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
Mike Snitzer28eed342012-10-12 21:02:07 +01002423 else
2424 /*
2425 * Use largest power of 2 that is a factor of sectors_per_block
2426 * but at least DATA_DEV_BLOCK_SIZE_MIN_SECTORS.
2427 */
2428 limits->discard_granularity = max(1 << (ffs(pool->sectors_per_block) - 1),
2429 DATA_DEV_BLOCK_SIZE_MIN_SECTORS) << SECTOR_SHIFT;
Joe Thornber104655f2012-03-28 18:41:28 +01002430}
2431
Joe Thornber991d9fa2011-10-31 20:21:18 +00002432static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
2433{
2434 struct pool_c *pt = ti->private;
2435 struct pool *pool = pt->pool;
2436
2437 blk_limits_io_min(limits, 0);
2438 blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
Mike Snitzer0424caa2012-09-26 23:45:47 +01002439
2440 /*
2441 * pt->adjusted_pf is a staging area for the actual features to use.
2442 * They get transferred to the live pool in bind_control_target()
2443 * called from pool_preresume().
2444 */
2445 if (!pt->adjusted_pf.discard_enabled)
2446 return;
2447
2448 disable_passdown_if_not_supported(pt);
2449
2450 set_discard_limits(pt, limits);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002451}
2452
2453static struct target_type pool_target = {
2454 .name = "thin-pool",
2455 .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
2456 DM_TARGET_IMMUTABLE,
Mike Snitzer4f81a412012-10-12 21:02:13 +01002457 .version = {1, 5, 0},
Joe Thornber991d9fa2011-10-31 20:21:18 +00002458 .module = THIS_MODULE,
2459 .ctr = pool_ctr,
2460 .dtr = pool_dtr,
2461 .map = pool_map,
2462 .postsuspend = pool_postsuspend,
2463 .preresume = pool_preresume,
2464 .resume = pool_resume,
2465 .message = pool_message,
2466 .status = pool_status,
2467 .merge = pool_merge,
2468 .iterate_devices = pool_iterate_devices,
2469 .io_hints = pool_io_hints,
2470};
2471
2472/*----------------------------------------------------------------
2473 * Thin target methods
2474 *--------------------------------------------------------------*/
2475static void thin_dtr(struct dm_target *ti)
2476{
2477 struct thin_c *tc = ti->private;
2478
2479 mutex_lock(&dm_thin_pool_table.mutex);
2480
2481 __pool_dec(tc->pool);
2482 dm_pool_close_thin_device(tc->td);
2483 dm_put_device(ti, tc->pool_dev);
Joe Thornber2dd9c252012-03-28 18:41:28 +01002484 if (tc->origin_dev)
2485 dm_put_device(ti, tc->origin_dev);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002486 kfree(tc);
2487
2488 mutex_unlock(&dm_thin_pool_table.mutex);
2489}
2490
2491/*
2492 * Thin target parameters:
2493 *
Joe Thornber2dd9c252012-03-28 18:41:28 +01002494 * <pool_dev> <dev_id> [origin_dev]
Joe Thornber991d9fa2011-10-31 20:21:18 +00002495 *
2496 * pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
2497 * dev_id: the internal device identifier
Joe Thornber2dd9c252012-03-28 18:41:28 +01002498 * origin_dev: a device external to the pool that should act as the origin
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002499 *
2500 * If the pool device has discards disabled, they get disabled for the thin
2501 * device as well.
Joe Thornber991d9fa2011-10-31 20:21:18 +00002502 */
2503static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
2504{
2505 int r;
2506 struct thin_c *tc;
Joe Thornber2dd9c252012-03-28 18:41:28 +01002507 struct dm_dev *pool_dev, *origin_dev;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002508 struct mapped_device *pool_md;
2509
2510 mutex_lock(&dm_thin_pool_table.mutex);
2511
Joe Thornber2dd9c252012-03-28 18:41:28 +01002512 if (argc != 2 && argc != 3) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00002513 ti->error = "Invalid argument count";
2514 r = -EINVAL;
2515 goto out_unlock;
2516 }
2517
2518 tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL);
2519 if (!tc) {
2520 ti->error = "Out of memory";
2521 r = -ENOMEM;
2522 goto out_unlock;
2523 }
2524
Joe Thornber2dd9c252012-03-28 18:41:28 +01002525 if (argc == 3) {
2526 r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev);
2527 if (r) {
2528 ti->error = "Error opening origin device";
2529 goto bad_origin_dev;
2530 }
2531 tc->origin_dev = origin_dev;
2532 }
2533
Joe Thornber991d9fa2011-10-31 20:21:18 +00002534 r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev);
2535 if (r) {
2536 ti->error = "Error opening pool device";
2537 goto bad_pool_dev;
2538 }
2539 tc->pool_dev = pool_dev;
2540
2541 if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) {
2542 ti->error = "Invalid device id";
2543 r = -EINVAL;
2544 goto bad_common;
2545 }
2546
2547 pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev);
2548 if (!pool_md) {
2549 ti->error = "Couldn't get pool mapped device";
2550 r = -EINVAL;
2551 goto bad_common;
2552 }
2553
2554 tc->pool = __pool_table_lookup(pool_md);
2555 if (!tc->pool) {
2556 ti->error = "Couldn't find pool object";
2557 r = -EINVAL;
2558 goto bad_pool_lookup;
2559 }
2560 __pool_inc(tc->pool);
2561
Joe Thornbere49e5822012-07-27 15:08:16 +01002562 if (get_pool_mode(tc->pool) == PM_FAIL) {
2563 ti->error = "Couldn't open thin device, Pool is in fail mode";
2564 goto bad_thin_open;
2565 }
2566
Joe Thornber991d9fa2011-10-31 20:21:18 +00002567 r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td);
2568 if (r) {
2569 ti->error = "Couldn't open thin internal device";
2570 goto bad_thin_open;
2571 }
2572
Mike Snitzer542f9032012-07-27 15:08:00 +01002573 r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
2574 if (r)
2575 goto bad_thin_open;
2576
Joe Thornber991d9fa2011-10-31 20:21:18 +00002577 ti->num_flush_requests = 1;
Joe Thornber16ad3d12012-07-27 15:08:07 +01002578 ti->flush_supported = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002579
2580 /* In case the pool supports discards, pass them on. */
2581 if (tc->pool->pf.discard_enabled) {
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01002582 ti->discards_supported = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002583 ti->num_discard_requests = 1;
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01002584 ti->discard_zeroes_data_unsupported = true;
Mikulas Patocka49296302012-07-27 15:08:03 +01002585 /* Discard requests must be split on a block boundary */
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01002586 ti->split_discard_requests = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002587 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002588
2589 dm_put(pool_md);
2590
2591 mutex_unlock(&dm_thin_pool_table.mutex);
2592
2593 return 0;
2594
2595bad_thin_open:
2596 __pool_dec(tc->pool);
2597bad_pool_lookup:
2598 dm_put(pool_md);
2599bad_common:
2600 dm_put_device(ti, tc->pool_dev);
2601bad_pool_dev:
Joe Thornber2dd9c252012-03-28 18:41:28 +01002602 if (tc->origin_dev)
2603 dm_put_device(ti, tc->origin_dev);
2604bad_origin_dev:
Joe Thornber991d9fa2011-10-31 20:21:18 +00002605 kfree(tc);
2606out_unlock:
2607 mutex_unlock(&dm_thin_pool_table.mutex);
2608
2609 return r;
2610}
2611
2612static int thin_map(struct dm_target *ti, struct bio *bio,
2613 union map_info *map_context)
2614{
Alasdair G Kergon6efd6e82012-03-28 18:41:28 +01002615 bio->bi_sector = dm_target_offset(ti, bio->bi_sector);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002616
2617 return thin_bio_map(ti, bio, map_context);
2618}
2619
Joe Thornbereb2aa482012-03-28 18:41:28 +01002620static int thin_endio(struct dm_target *ti,
2621 struct bio *bio, int err,
2622 union map_info *map_context)
2623{
2624 unsigned long flags;
Mike Snitzera24c2562012-06-03 00:30:00 +01002625 struct dm_thin_endio_hook *h = map_context->ptr;
Joe Thornbereb2aa482012-03-28 18:41:28 +01002626 struct list_head work;
Mike Snitzera24c2562012-06-03 00:30:00 +01002627 struct dm_thin_new_mapping *m, *tmp;
Joe Thornbereb2aa482012-03-28 18:41:28 +01002628 struct pool *pool = h->tc->pool;
2629
2630 if (h->shared_read_entry) {
2631 INIT_LIST_HEAD(&work);
Mike Snitzer44feb382012-10-12 21:02:10 +01002632 dm_deferred_entry_dec(h->shared_read_entry, &work);
Joe Thornbereb2aa482012-03-28 18:41:28 +01002633
2634 spin_lock_irqsave(&pool->lock, flags);
2635 list_for_each_entry_safe(m, tmp, &work, list) {
2636 list_del(&m->list);
2637 m->quiesced = 1;
2638 __maybe_add_mapping(m);
2639 }
2640 spin_unlock_irqrestore(&pool->lock, flags);
2641 }
2642
Joe Thornber104655f2012-03-28 18:41:28 +01002643 if (h->all_io_entry) {
2644 INIT_LIST_HEAD(&work);
Mike Snitzer44feb382012-10-12 21:02:10 +01002645 dm_deferred_entry_dec(h->all_io_entry, &work);
Mike Snitzerc3a0ce22012-05-12 01:43:16 +01002646 spin_lock_irqsave(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +01002647 list_for_each_entry_safe(m, tmp, &work, list)
2648 list_add(&m->list, &pool->prepared_discards);
Mike Snitzerc3a0ce22012-05-12 01:43:16 +01002649 spin_unlock_irqrestore(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +01002650 }
2651
Joe Thornbereb2aa482012-03-28 18:41:28 +01002652 mempool_free(h, pool->endio_hook_pool);
2653
2654 return 0;
2655}
2656
Joe Thornber991d9fa2011-10-31 20:21:18 +00002657static void thin_postsuspend(struct dm_target *ti)
2658{
2659 if (dm_noflush_suspending(ti))
2660 requeue_io((struct thin_c *)ti->private);
2661}
2662
2663/*
2664 * <nr mapped sectors> <highest mapped sector>
2665 */
2666static int thin_status(struct dm_target *ti, status_type_t type,
Alasdair G Kergon1f4e0ff2012-07-27 15:08:16 +01002667 unsigned status_flags, char *result, unsigned maxlen)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002668{
2669 int r;
2670 ssize_t sz = 0;
2671 dm_block_t mapped, highest;
2672 char buf[BDEVNAME_SIZE];
2673 struct thin_c *tc = ti->private;
2674
Joe Thornbere49e5822012-07-27 15:08:16 +01002675 if (get_pool_mode(tc->pool) == PM_FAIL) {
2676 DMEMIT("Fail");
2677 return 0;
2678 }
2679
Joe Thornber991d9fa2011-10-31 20:21:18 +00002680 if (!tc->td)
2681 DMEMIT("-");
2682 else {
2683 switch (type) {
2684 case STATUSTYPE_INFO:
2685 r = dm_thin_get_mapped_count(tc->td, &mapped);
2686 if (r)
2687 return r;
2688
2689 r = dm_thin_get_highest_mapped_block(tc->td, &highest);
2690 if (r < 0)
2691 return r;
2692
2693 DMEMIT("%llu ", mapped * tc->pool->sectors_per_block);
2694 if (r)
2695 DMEMIT("%llu", ((highest + 1) *
2696 tc->pool->sectors_per_block) - 1);
2697 else
2698 DMEMIT("-");
2699 break;
2700
2701 case STATUSTYPE_TABLE:
2702 DMEMIT("%s %lu",
2703 format_dev_t(buf, tc->pool_dev->bdev->bd_dev),
2704 (unsigned long) tc->dev_id);
Joe Thornber2dd9c252012-03-28 18:41:28 +01002705 if (tc->origin_dev)
2706 DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev));
Joe Thornber991d9fa2011-10-31 20:21:18 +00002707 break;
2708 }
2709 }
2710
2711 return 0;
2712}
2713
2714static int thin_iterate_devices(struct dm_target *ti,
2715 iterate_devices_callout_fn fn, void *data)
2716{
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002717 sector_t blocks;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002718 struct thin_c *tc = ti->private;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002719 struct pool *pool = tc->pool;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002720
2721 /*
2722 * We can't call dm_pool_get_data_dev_size() since that blocks. So
2723 * we follow a more convoluted path through to the pool's target.
2724 */
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002725 if (!pool->ti)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002726 return 0; /* nothing is bound */
2727
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002728 blocks = pool->ti->len;
2729 (void) sector_div(blocks, pool->sectors_per_block);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002730 if (blocks)
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002731 return fn(ti, tc->pool_dev, 0, pool->sectors_per_block * blocks, data);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002732
2733 return 0;
2734}
2735
Mike Snitzer0424caa2012-09-26 23:45:47 +01002736/*
2737 * A thin device always inherits its queue limits from its pool.
2738 */
Joe Thornber991d9fa2011-10-31 20:21:18 +00002739static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
2740{
2741 struct thin_c *tc = ti->private;
2742
Mike Snitzer0424caa2012-09-26 23:45:47 +01002743 *limits = bdev_get_queue(tc->pool_dev->bdev)->limits;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002744}
2745
2746static struct target_type thin_target = {
2747 .name = "thin",
Mike Snitzer4f81a412012-10-12 21:02:13 +01002748 .version = {1, 5, 0},
Joe Thornber991d9fa2011-10-31 20:21:18 +00002749 .module = THIS_MODULE,
2750 .ctr = thin_ctr,
2751 .dtr = thin_dtr,
2752 .map = thin_map,
Joe Thornbereb2aa482012-03-28 18:41:28 +01002753 .end_io = thin_endio,
Joe Thornber991d9fa2011-10-31 20:21:18 +00002754 .postsuspend = thin_postsuspend,
2755 .status = thin_status,
2756 .iterate_devices = thin_iterate_devices,
2757 .io_hints = thin_io_hints,
2758};
2759
2760/*----------------------------------------------------------------*/
2761
2762static int __init dm_thin_init(void)
2763{
2764 int r;
2765
2766 pool_table_init();
2767
2768 r = dm_register_target(&thin_target);
2769 if (r)
2770 return r;
2771
2772 r = dm_register_target(&pool_target);
2773 if (r)
Mike Snitzera24c2562012-06-03 00:30:00 +01002774 goto bad_pool_target;
2775
2776 r = -ENOMEM;
2777
Mike Snitzera24c2562012-06-03 00:30:00 +01002778 _new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
2779 if (!_new_mapping_cache)
2780 goto bad_new_mapping_cache;
2781
2782 _endio_hook_cache = KMEM_CACHE(dm_thin_endio_hook, 0);
2783 if (!_endio_hook_cache)
2784 goto bad_endio_hook_cache;
2785
2786 return 0;
2787
2788bad_endio_hook_cache:
2789 kmem_cache_destroy(_new_mapping_cache);
2790bad_new_mapping_cache:
Mike Snitzera24c2562012-06-03 00:30:00 +01002791 dm_unregister_target(&pool_target);
2792bad_pool_target:
2793 dm_unregister_target(&thin_target);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002794
2795 return r;
2796}
2797
2798static void dm_thin_exit(void)
2799{
2800 dm_unregister_target(&thin_target);
2801 dm_unregister_target(&pool_target);
Mike Snitzera24c2562012-06-03 00:30:00 +01002802
Mike Snitzera24c2562012-06-03 00:30:00 +01002803 kmem_cache_destroy(_new_mapping_cache);
2804 kmem_cache_destroy(_endio_hook_cache);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002805}
2806
2807module_init(dm_thin_init);
2808module_exit(dm_thin_exit);
2809
Alasdair G Kergon7cab8bf2012-05-12 01:43:19 +01002810MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
Joe Thornber991d9fa2011-10-31 20:21:18 +00002811MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
2812MODULE_LICENSE("GPL");