blob: 675ae5274016da37484b2c05bfefccad8e158543 [file] [log] [blame]
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;
Joe Thornbere49e5822012-07-27 15:08:16 +0100189
190 process_bio_fn process_bio;
191 process_bio_fn process_discard;
192
193 process_mapping_fn process_prepared_mapping;
194 process_mapping_fn process_prepared_discard;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000195};
196
Joe Thornbere49e5822012-07-27 15:08:16 +0100197static enum pool_mode get_pool_mode(struct pool *pool);
198static void set_pool_mode(struct pool *pool, enum pool_mode mode);
199
Joe Thornber991d9fa2011-10-31 20:21:18 +0000200/*
201 * Target context for a pool.
202 */
203struct pool_c {
204 struct dm_target *ti;
205 struct pool *pool;
206 struct dm_dev *data_dev;
207 struct dm_dev *metadata_dev;
208 struct dm_target_callbacks callbacks;
209
210 dm_block_t low_water_blocks;
Mike Snitzer0424caa2012-09-26 23:45:47 +0100211 struct pool_features requested_pf; /* Features requested during table load */
212 struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */
Joe Thornber991d9fa2011-10-31 20:21:18 +0000213};
214
215/*
216 * Target context for a thin.
217 */
218struct thin_c {
219 struct dm_dev *pool_dev;
Joe Thornber2dd9c252012-03-28 18:41:28 +0100220 struct dm_dev *origin_dev;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000221 dm_thin_id dev_id;
222
223 struct pool *pool;
224 struct dm_thin_device *td;
225};
226
227/*----------------------------------------------------------------*/
228
229/*
230 * A global list of pools that uses a struct mapped_device as a key.
231 */
232static struct dm_thin_pool_table {
233 struct mutex mutex;
234 struct list_head pools;
235} dm_thin_pool_table;
236
237static void pool_table_init(void)
238{
239 mutex_init(&dm_thin_pool_table.mutex);
240 INIT_LIST_HEAD(&dm_thin_pool_table.pools);
241}
242
243static void __pool_table_insert(struct pool *pool)
244{
245 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
246 list_add(&pool->list, &dm_thin_pool_table.pools);
247}
248
249static void __pool_table_remove(struct pool *pool)
250{
251 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
252 list_del(&pool->list);
253}
254
255static struct pool *__pool_table_lookup(struct mapped_device *md)
256{
257 struct pool *pool = NULL, *tmp;
258
259 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
260
261 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
262 if (tmp->pool_md == md) {
263 pool = tmp;
264 break;
265 }
266 }
267
268 return pool;
269}
270
271static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev)
272{
273 struct pool *pool = NULL, *tmp;
274
275 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
276
277 list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
278 if (tmp->md_dev == md_dev) {
279 pool = tmp;
280 break;
281 }
282 }
283
284 return pool;
285}
286
287/*----------------------------------------------------------------*/
288
Mike Snitzera24c2562012-06-03 00:30:00 +0100289struct dm_thin_endio_hook {
Joe Thornbereb2aa482012-03-28 18:41:28 +0100290 struct thin_c *tc;
Mike Snitzer44feb382012-10-12 21:02:10 +0100291 struct dm_deferred_entry *shared_read_entry;
292 struct dm_deferred_entry *all_io_entry;
Mike Snitzera24c2562012-06-03 00:30:00 +0100293 struct dm_thin_new_mapping *overwrite_mapping;
Joe Thornbereb2aa482012-03-28 18:41:28 +0100294};
295
Joe Thornber991d9fa2011-10-31 20:21:18 +0000296static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master)
297{
298 struct bio *bio;
299 struct bio_list bios;
300
301 bio_list_init(&bios);
302 bio_list_merge(&bios, master);
303 bio_list_init(master);
304
305 while ((bio = bio_list_pop(&bios))) {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000306 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Mike Snitzera24c2562012-06-03 00:30:00 +0100307
Joe Thornbereb2aa482012-03-28 18:41:28 +0100308 if (h->tc == tc)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000309 bio_endio(bio, DM_ENDIO_REQUEUE);
310 else
311 bio_list_add(master, bio);
312 }
313}
314
315static void requeue_io(struct thin_c *tc)
316{
317 struct pool *pool = tc->pool;
318 unsigned long flags;
319
320 spin_lock_irqsave(&pool->lock, flags);
321 __requeue_bio_list(tc, &pool->deferred_bios);
322 __requeue_bio_list(tc, &pool->retry_on_resume_list);
323 spin_unlock_irqrestore(&pool->lock, flags);
324}
325
326/*
327 * This section of code contains the logic for processing a thin device's IO.
328 * Much of the code depends on pool object resources (lists, workqueues, etc)
329 * but most is exclusively called from the thin target rather than the thin-pool
330 * target.
331 */
332
333static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
334{
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100335 sector_t block_nr = bio->bi_sector;
336
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100337 if (tc->pool->sectors_per_block_shift < 0)
338 (void) sector_div(block_nr, tc->pool->sectors_per_block);
339 else
340 block_nr >>= tc->pool->sectors_per_block_shift;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100341
342 return block_nr;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000343}
344
345static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
346{
347 struct pool *pool = tc->pool;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +0100348 sector_t bi_sector = bio->bi_sector;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000349
350 bio->bi_bdev = tc->pool_dev->bdev;
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100351 if (tc->pool->sectors_per_block_shift < 0)
352 bio->bi_sector = (block * pool->sectors_per_block) +
353 sector_div(bi_sector, pool->sectors_per_block);
354 else
355 bio->bi_sector = (block << pool->sectors_per_block_shift) |
356 (bi_sector & (pool->sectors_per_block - 1));
Joe Thornber991d9fa2011-10-31 20:21:18 +0000357}
358
Joe Thornber2dd9c252012-03-28 18:41:28 +0100359static void remap_to_origin(struct thin_c *tc, struct bio *bio)
360{
361 bio->bi_bdev = tc->origin_dev->bdev;
362}
363
Joe Thornber4afdd682012-07-27 15:08:14 +0100364static int bio_triggers_commit(struct thin_c *tc, struct bio *bio)
365{
366 return (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) &&
367 dm_thin_changed_this_transaction(tc->td);
368}
369
Joe Thornbere8088072012-12-21 20:23:31 +0000370static void inc_all_io_entry(struct pool *pool, struct bio *bio)
371{
372 struct dm_thin_endio_hook *h;
373
374 if (bio->bi_rw & REQ_DISCARD)
375 return;
376
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000377 h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbere8088072012-12-21 20:23:31 +0000378 h->all_io_entry = dm_deferred_entry_inc(pool->all_io_ds);
379}
380
Joe Thornber2dd9c252012-03-28 18:41:28 +0100381static void issue(struct thin_c *tc, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000382{
383 struct pool *pool = tc->pool;
384 unsigned long flags;
385
Joe Thornbere49e5822012-07-27 15:08:16 +0100386 if (!bio_triggers_commit(tc, bio)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000387 generic_make_request(bio);
Joe Thornbere49e5822012-07-27 15:08:16 +0100388 return;
389 }
390
391 /*
392 * Complete bio with an error if earlier I/O caused changes to
393 * the metadata that can't be committed e.g, due to I/O errors
394 * on the metadata device.
395 */
396 if (dm_thin_aborted_changes(tc->td)) {
397 bio_io_error(bio);
398 return;
399 }
400
401 /*
402 * Batch together any bios that trigger commits and then issue a
403 * single commit for them in process_deferred_bios().
404 */
405 spin_lock_irqsave(&pool->lock, flags);
406 bio_list_add(&pool->deferred_flush_bios, bio);
407 spin_unlock_irqrestore(&pool->lock, flags);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000408}
409
Joe Thornber2dd9c252012-03-28 18:41:28 +0100410static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio)
411{
412 remap_to_origin(tc, bio);
413 issue(tc, bio);
414}
415
416static void remap_and_issue(struct thin_c *tc, struct bio *bio,
417 dm_block_t block)
418{
419 remap(tc, bio, block);
420 issue(tc, bio);
421}
422
Joe Thornber991d9fa2011-10-31 20:21:18 +0000423/*
424 * wake_worker() is used when new work is queued and when pool_resume is
425 * ready to continue deferred IO processing.
426 */
427static void wake_worker(struct pool *pool)
428{
429 queue_work(pool->wq, &pool->worker);
430}
431
432/*----------------------------------------------------------------*/
433
434/*
435 * Bio endio functions.
436 */
Mike Snitzera24c2562012-06-03 00:30:00 +0100437struct dm_thin_new_mapping {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000438 struct list_head list;
439
Joe Thornbereb2aa482012-03-28 18:41:28 +0100440 unsigned quiesced:1;
441 unsigned prepared:1;
Joe Thornber104655f2012-03-28 18:41:28 +0100442 unsigned pass_discard:1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000443
444 struct thin_c *tc;
445 dm_block_t virt_block;
446 dm_block_t data_block;
Mike Snitzera24c2562012-06-03 00:30:00 +0100447 struct dm_bio_prison_cell *cell, *cell2;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000448 int err;
449
450 /*
451 * If the bio covers the whole area of a block then we can avoid
452 * zeroing or copying. Instead this bio is hooked. The bio will
453 * still be in the cell, so care has to be taken to avoid issuing
454 * the bio twice.
455 */
456 struct bio *bio;
457 bio_end_io_t *saved_bi_end_io;
458};
459
Mike Snitzera24c2562012-06-03 00:30:00 +0100460static void __maybe_add_mapping(struct dm_thin_new_mapping *m)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000461{
462 struct pool *pool = m->tc->pool;
463
Joe Thornbereb2aa482012-03-28 18:41:28 +0100464 if (m->quiesced && m->prepared) {
Joe Thornber991d9fa2011-10-31 20:21:18 +0000465 list_add(&m->list, &pool->prepared_mappings);
466 wake_worker(pool);
467 }
468}
469
470static void copy_complete(int read_err, unsigned long write_err, void *context)
471{
472 unsigned long flags;
Mike Snitzera24c2562012-06-03 00:30:00 +0100473 struct dm_thin_new_mapping *m = context;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000474 struct pool *pool = m->tc->pool;
475
476 m->err = read_err || write_err ? -EIO : 0;
477
478 spin_lock_irqsave(&pool->lock, flags);
479 m->prepared = 1;
480 __maybe_add_mapping(m);
481 spin_unlock_irqrestore(&pool->lock, flags);
482}
483
484static void overwrite_endio(struct bio *bio, int err)
485{
486 unsigned long flags;
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000487 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Mike Snitzera24c2562012-06-03 00:30:00 +0100488 struct dm_thin_new_mapping *m = h->overwrite_mapping;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000489 struct pool *pool = m->tc->pool;
490
491 m->err = err;
492
493 spin_lock_irqsave(&pool->lock, flags);
494 m->prepared = 1;
495 __maybe_add_mapping(m);
496 spin_unlock_irqrestore(&pool->lock, flags);
497}
498
Joe Thornber991d9fa2011-10-31 20:21:18 +0000499/*----------------------------------------------------------------*/
500
501/*
502 * Workqueue.
503 */
504
505/*
506 * Prepared mapping jobs.
507 */
508
509/*
510 * This sends the bios in the cell back to the deferred_bios list.
511 */
Joe Thornber2aab3852012-12-21 20:23:33 +0000512static void cell_defer(struct thin_c *tc, struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000513{
514 struct pool *pool = tc->pool;
515 unsigned long flags;
516
517 spin_lock_irqsave(&pool->lock, flags);
Mike Snitzer44feb382012-10-12 21:02:10 +0100518 dm_cell_release(cell, &pool->deferred_bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000519 spin_unlock_irqrestore(&tc->pool->lock, flags);
520
521 wake_worker(pool);
522}
523
524/*
Joe Thornberb7ca9c92012-12-21 20:23:31 +0000525 * Same as cell_defer except it omits the original holder of the cell.
Joe Thornber991d9fa2011-10-31 20:21:18 +0000526 */
Joe Thornberf286ba02012-12-21 20:23:33 +0000527static void cell_defer_no_holder(struct thin_c *tc, struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000528{
Joe Thornber991d9fa2011-10-31 20:21:18 +0000529 struct pool *pool = tc->pool;
530 unsigned long flags;
531
Joe Thornber991d9fa2011-10-31 20:21:18 +0000532 spin_lock_irqsave(&pool->lock, flags);
Mike Snitzer44feb382012-10-12 21:02:10 +0100533 dm_cell_release_no_holder(cell, &pool->deferred_bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000534 spin_unlock_irqrestore(&pool->lock, flags);
535
536 wake_worker(pool);
537}
538
Joe Thornbere49e5822012-07-27 15:08:16 +0100539static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
540{
541 if (m->bio)
542 m->bio->bi_end_io = m->saved_bi_end_io;
Mike Snitzer44feb382012-10-12 21:02:10 +0100543 dm_cell_error(m->cell);
Joe Thornbere49e5822012-07-27 15:08:16 +0100544 list_del(&m->list);
545 mempool_free(m, m->tc->pool->mapping_pool);
546}
Mike Snitzera24c2562012-06-03 00:30:00 +0100547static void process_prepared_mapping(struct dm_thin_new_mapping *m)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000548{
549 struct thin_c *tc = m->tc;
550 struct bio *bio;
551 int r;
552
553 bio = m->bio;
554 if (bio)
555 bio->bi_end_io = m->saved_bi_end_io;
556
557 if (m->err) {
Mike Snitzer44feb382012-10-12 21:02:10 +0100558 dm_cell_error(m->cell);
Joe Thornber905386f2012-07-27 15:08:05 +0100559 goto out;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000560 }
561
562 /*
563 * Commit the prepared block into the mapping btree.
564 * Any I/O for this block arriving after this point will get
565 * remapped to it directly.
566 */
567 r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);
568 if (r) {
Mike Snitzerc3977412012-12-21 20:23:34 +0000569 DMERR_LIMIT("dm_thin_insert_block() failed");
Mike Snitzer44feb382012-10-12 21:02:10 +0100570 dm_cell_error(m->cell);
Joe Thornber905386f2012-07-27 15:08:05 +0100571 goto out;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000572 }
573
574 /*
575 * Release any bios held while the block was being provisioned.
576 * If we are processing a write bio that completely covers the block,
577 * we already processed it so can ignore it now when processing
578 * the bios in the cell.
579 */
580 if (bio) {
Joe Thornberf286ba02012-12-21 20:23:33 +0000581 cell_defer_no_holder(tc, m->cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000582 bio_endio(bio, 0);
583 } else
Joe Thornber2aab3852012-12-21 20:23:33 +0000584 cell_defer(tc, m->cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000585
Joe Thornber905386f2012-07-27 15:08:05 +0100586out:
Joe Thornber991d9fa2011-10-31 20:21:18 +0000587 list_del(&m->list);
588 mempool_free(m, tc->pool->mapping_pool);
589}
590
Joe Thornbere49e5822012-07-27 15:08:16 +0100591static void process_prepared_discard_fail(struct dm_thin_new_mapping *m)
Joe Thornber104655f2012-03-28 18:41:28 +0100592{
Joe Thornber104655f2012-03-28 18:41:28 +0100593 struct thin_c *tc = m->tc;
594
Joe Thornbere49e5822012-07-27 15:08:16 +0100595 bio_io_error(m->bio);
Joe Thornberf286ba02012-12-21 20:23:33 +0000596 cell_defer_no_holder(tc, m->cell);
597 cell_defer_no_holder(tc, m->cell2);
Joe Thornbere49e5822012-07-27 15:08:16 +0100598 mempool_free(m, tc->pool->mapping_pool);
599}
Joe Thornber104655f2012-03-28 18:41:28 +0100600
Joe Thornbere49e5822012-07-27 15:08:16 +0100601static void process_prepared_discard_passdown(struct dm_thin_new_mapping *m)
602{
603 struct thin_c *tc = m->tc;
604
Joe Thornbere8088072012-12-21 20:23:31 +0000605 inc_all_io_entry(tc->pool, m->bio);
Joe Thornberf286ba02012-12-21 20:23:33 +0000606 cell_defer_no_holder(tc, m->cell);
607 cell_defer_no_holder(tc, m->cell2);
Joe Thornbere8088072012-12-21 20:23:31 +0000608
Joe Thornber104655f2012-03-28 18:41:28 +0100609 if (m->pass_discard)
610 remap_and_issue(tc, m->bio, m->data_block);
611 else
612 bio_endio(m->bio, 0);
613
Joe Thornber104655f2012-03-28 18:41:28 +0100614 mempool_free(m, tc->pool->mapping_pool);
615}
616
Joe Thornbere49e5822012-07-27 15:08:16 +0100617static void process_prepared_discard(struct dm_thin_new_mapping *m)
618{
619 int r;
620 struct thin_c *tc = m->tc;
621
622 r = dm_thin_remove_block(tc->td, m->virt_block);
623 if (r)
Mike Snitzerc3977412012-12-21 20:23:34 +0000624 DMERR_LIMIT("dm_thin_remove_block() failed");
Joe Thornbere49e5822012-07-27 15:08:16 +0100625
626 process_prepared_discard_passdown(m);
627}
628
Joe Thornber104655f2012-03-28 18:41:28 +0100629static void process_prepared(struct pool *pool, struct list_head *head,
Joe Thornbere49e5822012-07-27 15:08:16 +0100630 process_mapping_fn *fn)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000631{
632 unsigned long flags;
633 struct list_head maps;
Mike Snitzera24c2562012-06-03 00:30:00 +0100634 struct dm_thin_new_mapping *m, *tmp;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000635
636 INIT_LIST_HEAD(&maps);
637 spin_lock_irqsave(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +0100638 list_splice_init(head, &maps);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000639 spin_unlock_irqrestore(&pool->lock, flags);
640
641 list_for_each_entry_safe(m, tmp, &maps, list)
Joe Thornbere49e5822012-07-27 15:08:16 +0100642 (*fn)(m);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000643}
644
645/*
646 * Deferred bio jobs.
647 */
Joe Thornber104655f2012-03-28 18:41:28 +0100648static int io_overlaps_block(struct pool *pool, struct bio *bio)
649{
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +0100650 return bio->bi_size == (pool->sectors_per_block << SECTOR_SHIFT);
Joe Thornber104655f2012-03-28 18:41:28 +0100651}
652
Joe Thornber991d9fa2011-10-31 20:21:18 +0000653static int io_overwrites_block(struct pool *pool, struct bio *bio)
654{
Joe Thornber104655f2012-03-28 18:41:28 +0100655 return (bio_data_dir(bio) == WRITE) &&
656 io_overlaps_block(pool, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000657}
658
659static void save_and_set_endio(struct bio *bio, bio_end_io_t **save,
660 bio_end_io_t *fn)
661{
662 *save = bio->bi_end_io;
663 bio->bi_end_io = fn;
664}
665
666static int ensure_next_mapping(struct pool *pool)
667{
668 if (pool->next_mapping)
669 return 0;
670
671 pool->next_mapping = mempool_alloc(pool->mapping_pool, GFP_ATOMIC);
672
673 return pool->next_mapping ? 0 : -ENOMEM;
674}
675
Mike Snitzera24c2562012-06-03 00:30:00 +0100676static struct dm_thin_new_mapping *get_next_mapping(struct pool *pool)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000677{
Mike Snitzera24c2562012-06-03 00:30:00 +0100678 struct dm_thin_new_mapping *r = pool->next_mapping;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000679
680 BUG_ON(!pool->next_mapping);
681
682 pool->next_mapping = NULL;
683
684 return r;
685}
686
687static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
Joe Thornber2dd9c252012-03-28 18:41:28 +0100688 struct dm_dev *origin, dm_block_t data_origin,
689 dm_block_t data_dest,
Mike Snitzera24c2562012-06-03 00:30:00 +0100690 struct dm_bio_prison_cell *cell, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000691{
692 int r;
693 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +0100694 struct dm_thin_new_mapping *m = get_next_mapping(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000695
696 INIT_LIST_HEAD(&m->list);
Joe Thornbereb2aa482012-03-28 18:41:28 +0100697 m->quiesced = 0;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000698 m->prepared = 0;
699 m->tc = tc;
700 m->virt_block = virt_block;
701 m->data_block = data_dest;
702 m->cell = cell;
703 m->err = 0;
704 m->bio = NULL;
705
Mike Snitzer44feb382012-10-12 21:02:10 +0100706 if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list))
Joe Thornbereb2aa482012-03-28 18:41:28 +0100707 m->quiesced = 1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000708
709 /*
710 * IO to pool_dev remaps to the pool target's data_dev.
711 *
712 * If the whole block of data is being overwritten, we can issue the
713 * bio immediately. Otherwise we use kcopyd to clone the data first.
714 */
715 if (io_overwrites_block(pool, bio)) {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000716 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Mike Snitzera24c2562012-06-03 00:30:00 +0100717
Joe Thornbereb2aa482012-03-28 18:41:28 +0100718 h->overwrite_mapping = m;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000719 m->bio = bio;
720 save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
Joe Thornbere8088072012-12-21 20:23:31 +0000721 inc_all_io_entry(pool, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000722 remap_and_issue(tc, bio, data_dest);
723 } else {
724 struct dm_io_region from, to;
725
Joe Thornber2dd9c252012-03-28 18:41:28 +0100726 from.bdev = origin->bdev;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000727 from.sector = data_origin * pool->sectors_per_block;
728 from.count = pool->sectors_per_block;
729
730 to.bdev = tc->pool_dev->bdev;
731 to.sector = data_dest * pool->sectors_per_block;
732 to.count = pool->sectors_per_block;
733
734 r = dm_kcopyd_copy(pool->copier, &from, 1, &to,
735 0, copy_complete, m);
736 if (r < 0) {
737 mempool_free(m, pool->mapping_pool);
Mike Snitzerc3977412012-12-21 20:23:34 +0000738 DMERR_LIMIT("dm_kcopyd_copy() failed");
Mike Snitzer44feb382012-10-12 21:02:10 +0100739 dm_cell_error(cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000740 }
741 }
742}
743
Joe Thornber2dd9c252012-03-28 18:41:28 +0100744static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block,
745 dm_block_t data_origin, 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->pool_dev,
749 data_origin, data_dest, cell, bio);
750}
751
752static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block,
753 dm_block_t data_dest,
Mike Snitzera24c2562012-06-03 00:30:00 +0100754 struct dm_bio_prison_cell *cell, struct bio *bio)
Joe Thornber2dd9c252012-03-28 18:41:28 +0100755{
756 schedule_copy(tc, virt_block, tc->origin_dev,
757 virt_block, data_dest, cell, bio);
758}
759
Joe Thornber991d9fa2011-10-31 20:21:18 +0000760static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
Mike Snitzera24c2562012-06-03 00:30:00 +0100761 dm_block_t data_block, struct dm_bio_prison_cell *cell,
Joe Thornber991d9fa2011-10-31 20:21:18 +0000762 struct bio *bio)
763{
764 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +0100765 struct dm_thin_new_mapping *m = get_next_mapping(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000766
767 INIT_LIST_HEAD(&m->list);
Joe Thornbereb2aa482012-03-28 18:41:28 +0100768 m->quiesced = 1;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000769 m->prepared = 0;
770 m->tc = tc;
771 m->virt_block = virt_block;
772 m->data_block = data_block;
773 m->cell = cell;
774 m->err = 0;
775 m->bio = NULL;
776
777 /*
778 * If the whole block of data is being overwritten or we are not
779 * zeroing pre-existing data, we can issue the bio immediately.
780 * Otherwise we use kcopyd to zero the data first.
781 */
Joe Thornber67e2e2b2012-03-28 18:41:29 +0100782 if (!pool->pf.zero_new_blocks)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000783 process_prepared_mapping(m);
784
785 else if (io_overwrites_block(pool, bio)) {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000786 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Mike Snitzera24c2562012-06-03 00:30:00 +0100787
Joe Thornbereb2aa482012-03-28 18:41:28 +0100788 h->overwrite_mapping = m;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000789 m->bio = bio;
790 save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
Joe Thornbere8088072012-12-21 20:23:31 +0000791 inc_all_io_entry(pool, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000792 remap_and_issue(tc, bio, data_block);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000793 } else {
794 int r;
795 struct dm_io_region to;
796
797 to.bdev = tc->pool_dev->bdev;
798 to.sector = data_block * pool->sectors_per_block;
799 to.count = pool->sectors_per_block;
800
801 r = dm_kcopyd_zero(pool->copier, 1, &to, 0, copy_complete, m);
802 if (r < 0) {
803 mempool_free(m, pool->mapping_pool);
Mike Snitzerc3977412012-12-21 20:23:34 +0000804 DMERR_LIMIT("dm_kcopyd_zero() failed");
Mike Snitzer44feb382012-10-12 21:02:10 +0100805 dm_cell_error(cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000806 }
807 }
808}
809
Joe Thornbere49e5822012-07-27 15:08:16 +0100810static int commit(struct pool *pool)
811{
812 int r;
813
814 r = dm_pool_commit_metadata(pool->pmd);
815 if (r)
Mike Snitzerc3977412012-12-21 20:23:34 +0000816 DMERR_LIMIT("commit failed: error = %d", r);
Joe Thornbere49e5822012-07-27 15:08:16 +0100817
818 return r;
819}
820
821/*
822 * A non-zero return indicates read_only or fail_io mode.
823 * Many callers don't care about the return value.
824 */
825static int commit_or_fallback(struct pool *pool)
826{
827 int r;
828
829 if (get_pool_mode(pool) != PM_WRITE)
830 return -EINVAL;
831
832 r = commit(pool);
833 if (r)
834 set_pool_mode(pool, PM_READ_ONLY);
835
836 return r;
837}
838
Joe Thornber991d9fa2011-10-31 20:21:18 +0000839static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
840{
841 int r;
842 dm_block_t free_blocks;
843 unsigned long flags;
844 struct pool *pool = tc->pool;
845
846 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
847 if (r)
848 return r;
849
850 if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) {
851 DMWARN("%s: reached low water mark, sending event.",
852 dm_device_name(pool->pool_md));
853 spin_lock_irqsave(&pool->lock, flags);
854 pool->low_water_triggered = 1;
855 spin_unlock_irqrestore(&pool->lock, flags);
856 dm_table_event(pool->ti->table);
857 }
858
859 if (!free_blocks) {
860 if (pool->no_free_space)
861 return -ENOSPC;
862 else {
863 /*
864 * Try to commit to see if that will free up some
865 * more space.
866 */
Joe Thornbere49e5822012-07-27 15:08:16 +0100867 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000868
869 r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
870 if (r)
871 return r;
872
873 /*
874 * If we still have no space we set a flag to avoid
875 * doing all this checking and return -ENOSPC.
876 */
877 if (!free_blocks) {
878 DMWARN("%s: no free space available.",
879 dm_device_name(pool->pool_md));
880 spin_lock_irqsave(&pool->lock, flags);
881 pool->no_free_space = 1;
882 spin_unlock_irqrestore(&pool->lock, flags);
883 return -ENOSPC;
884 }
885 }
886 }
887
888 r = dm_pool_alloc_data_block(pool->pmd, result);
889 if (r)
890 return r;
891
892 return 0;
893}
894
895/*
896 * If we have run out of space, queue bios until the device is
897 * resumed, presumably after having been reloaded with more space.
898 */
899static void retry_on_resume(struct bio *bio)
900{
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +0000901 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbereb2aa482012-03-28 18:41:28 +0100902 struct thin_c *tc = h->tc;
Joe Thornber991d9fa2011-10-31 20:21:18 +0000903 struct pool *pool = tc->pool;
904 unsigned long flags;
905
906 spin_lock_irqsave(&pool->lock, flags);
907 bio_list_add(&pool->retry_on_resume_list, bio);
908 spin_unlock_irqrestore(&pool->lock, flags);
909}
910
Mike Snitzera24c2562012-06-03 00:30:00 +0100911static void no_space(struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +0000912{
913 struct bio *bio;
914 struct bio_list bios;
915
916 bio_list_init(&bios);
Mike Snitzer44feb382012-10-12 21:02:10 +0100917 dm_cell_release(cell, &bios);
Joe Thornber991d9fa2011-10-31 20:21:18 +0000918
919 while ((bio = bio_list_pop(&bios)))
920 retry_on_resume(bio);
921}
922
Joe Thornber104655f2012-03-28 18:41:28 +0100923static void process_discard(struct thin_c *tc, struct bio *bio)
924{
925 int r;
Mike Snitzerc3a0ce22012-05-12 01:43:16 +0100926 unsigned long flags;
Joe Thornber104655f2012-03-28 18:41:28 +0100927 struct pool *pool = tc->pool;
Mike Snitzera24c2562012-06-03 00:30:00 +0100928 struct dm_bio_prison_cell *cell, *cell2;
Mike Snitzer44feb382012-10-12 21:02:10 +0100929 struct dm_cell_key key, key2;
Joe Thornber104655f2012-03-28 18:41:28 +0100930 dm_block_t block = get_bio_block(tc, bio);
931 struct dm_thin_lookup_result lookup_result;
Mike Snitzera24c2562012-06-03 00:30:00 +0100932 struct dm_thin_new_mapping *m;
Joe Thornber104655f2012-03-28 18:41:28 +0100933
934 build_virtual_key(tc->td, block, &key);
Mike Snitzer44feb382012-10-12 21:02:10 +0100935 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell))
Joe Thornber104655f2012-03-28 18:41:28 +0100936 return;
937
938 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
939 switch (r) {
940 case 0:
941 /*
942 * Check nobody is fiddling with this pool block. This can
943 * happen if someone's in the process of breaking sharing
944 * on this block.
945 */
946 build_data_key(tc->td, lookup_result.block, &key2);
Mike Snitzer44feb382012-10-12 21:02:10 +0100947 if (dm_bio_detain(tc->pool->prison, &key2, bio, &cell2)) {
Joe Thornberf286ba02012-12-21 20:23:33 +0000948 cell_defer_no_holder(tc, cell);
Joe Thornber104655f2012-03-28 18:41:28 +0100949 break;
950 }
951
952 if (io_overlaps_block(pool, bio)) {
953 /*
954 * IO may still be going to the destination block. We must
955 * quiesce before we can do the removal.
956 */
957 m = get_next_mapping(pool);
958 m->tc = tc;
Mike Snitzer17b7d632012-07-27 15:07:57 +0100959 m->pass_discard = (!lookup_result.shared) && pool->pf.discard_passdown;
Joe Thornber104655f2012-03-28 18:41:28 +0100960 m->virt_block = block;
961 m->data_block = lookup_result.block;
962 m->cell = cell;
963 m->cell2 = cell2;
964 m->err = 0;
965 m->bio = bio;
966
Mike Snitzer44feb382012-10-12 21:02:10 +0100967 if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) {
Mike Snitzerc3a0ce22012-05-12 01:43:16 +0100968 spin_lock_irqsave(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +0100969 list_add(&m->list, &pool->prepared_discards);
Mike Snitzerc3a0ce22012-05-12 01:43:16 +0100970 spin_unlock_irqrestore(&pool->lock, flags);
Joe Thornber104655f2012-03-28 18:41:28 +0100971 wake_worker(pool);
972 }
973 } else {
Joe Thornbere8088072012-12-21 20:23:31 +0000974 inc_all_io_entry(pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +0000975 cell_defer_no_holder(tc, cell);
976 cell_defer_no_holder(tc, cell2);
Joe Thornbere8088072012-12-21 20:23:31 +0000977
Joe Thornber104655f2012-03-28 18:41:28 +0100978 /*
Mikulas Patocka49296302012-07-27 15:08:03 +0100979 * The DM core makes sure that the discard doesn't span
980 * a block boundary. So we submit the discard of a
981 * partial block appropriately.
Joe Thornber104655f2012-03-28 18:41:28 +0100982 */
Mikulas Patocka650d2a02012-07-20 14:25:05 +0100983 if ((!lookup_result.shared) && pool->pf.discard_passdown)
984 remap_and_issue(tc, bio, lookup_result.block);
985 else
986 bio_endio(bio, 0);
Joe Thornber104655f2012-03-28 18:41:28 +0100987 }
988 break;
989
990 case -ENODATA:
991 /*
992 * It isn't provisioned, just forget it.
993 */
Joe Thornberf286ba02012-12-21 20:23:33 +0000994 cell_defer_no_holder(tc, cell);
Joe Thornber104655f2012-03-28 18:41:28 +0100995 bio_endio(bio, 0);
996 break;
997
998 default:
Mike Snitzerc3977412012-12-21 20:23:34 +0000999 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1000 __func__, r);
Joe Thornberf286ba02012-12-21 20:23:33 +00001001 cell_defer_no_holder(tc, cell);
Joe Thornber104655f2012-03-28 18:41:28 +01001002 bio_io_error(bio);
1003 break;
1004 }
1005}
1006
Joe Thornber991d9fa2011-10-31 20:21:18 +00001007static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
Mike Snitzer44feb382012-10-12 21:02:10 +01001008 struct dm_cell_key *key,
Joe Thornber991d9fa2011-10-31 20:21:18 +00001009 struct dm_thin_lookup_result *lookup_result,
Mike Snitzera24c2562012-06-03 00:30:00 +01001010 struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001011{
1012 int r;
1013 dm_block_t data_block;
1014
1015 r = alloc_data_block(tc, &data_block);
1016 switch (r) {
1017 case 0:
Joe Thornber2dd9c252012-03-28 18:41:28 +01001018 schedule_internal_copy(tc, block, lookup_result->block,
1019 data_block, cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001020 break;
1021
1022 case -ENOSPC:
1023 no_space(cell);
1024 break;
1025
1026 default:
Mike Snitzerc3977412012-12-21 20:23:34 +00001027 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1028 __func__, r);
Mike Snitzer44feb382012-10-12 21:02:10 +01001029 dm_cell_error(cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001030 break;
1031 }
1032}
1033
1034static void process_shared_bio(struct thin_c *tc, struct bio *bio,
1035 dm_block_t block,
1036 struct dm_thin_lookup_result *lookup_result)
1037{
Mike Snitzera24c2562012-06-03 00:30:00 +01001038 struct dm_bio_prison_cell *cell;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001039 struct pool *pool = tc->pool;
Mike Snitzer44feb382012-10-12 21:02:10 +01001040 struct dm_cell_key key;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001041
1042 /*
1043 * If cell is already occupied, then sharing is already in the process
1044 * of being broken so we have nothing further to do here.
1045 */
1046 build_data_key(tc->td, lookup_result->block, &key);
Mike Snitzer44feb382012-10-12 21:02:10 +01001047 if (dm_bio_detain(pool->prison, &key, bio, &cell))
Joe Thornber991d9fa2011-10-31 20:21:18 +00001048 return;
1049
Joe Thornber60049702012-07-27 15:08:06 +01001050 if (bio_data_dir(bio) == WRITE && bio->bi_size)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001051 break_sharing(tc, bio, block, &key, lookup_result, cell);
1052 else {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001053 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornber991d9fa2011-10-31 20:21:18 +00001054
Mike Snitzer44feb382012-10-12 21:02:10 +01001055 h->shared_read_entry = dm_deferred_entry_inc(pool->shared_read_ds);
Joe Thornbere8088072012-12-21 20:23:31 +00001056 inc_all_io_entry(pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001057 cell_defer_no_holder(tc, cell);
Joe Thornbere8088072012-12-21 20:23:31 +00001058
Joe Thornber991d9fa2011-10-31 20:21:18 +00001059 remap_and_issue(tc, bio, lookup_result->block);
1060 }
1061}
1062
1063static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block,
Mike Snitzera24c2562012-06-03 00:30:00 +01001064 struct dm_bio_prison_cell *cell)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001065{
1066 int r;
1067 dm_block_t data_block;
1068
1069 /*
1070 * Remap empty bios (flushes) immediately, without provisioning.
1071 */
1072 if (!bio->bi_size) {
Joe Thornbere8088072012-12-21 20:23:31 +00001073 inc_all_io_entry(tc->pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001074 cell_defer_no_holder(tc, cell);
Joe Thornbere8088072012-12-21 20:23:31 +00001075
Joe Thornber991d9fa2011-10-31 20:21:18 +00001076 remap_and_issue(tc, bio, 0);
1077 return;
1078 }
1079
1080 /*
1081 * Fill read bios with zeroes and complete them immediately.
1082 */
1083 if (bio_data_dir(bio) == READ) {
1084 zero_fill_bio(bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001085 cell_defer_no_holder(tc, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001086 bio_endio(bio, 0);
1087 return;
1088 }
1089
1090 r = alloc_data_block(tc, &data_block);
1091 switch (r) {
1092 case 0:
Joe Thornber2dd9c252012-03-28 18:41:28 +01001093 if (tc->origin_dev)
1094 schedule_external_copy(tc, block, data_block, cell, bio);
1095 else
1096 schedule_zero(tc, block, data_block, cell, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001097 break;
1098
1099 case -ENOSPC:
1100 no_space(cell);
1101 break;
1102
1103 default:
Mike Snitzerc3977412012-12-21 20:23:34 +00001104 DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
1105 __func__, r);
Joe Thornbere49e5822012-07-27 15:08:16 +01001106 set_pool_mode(tc->pool, PM_READ_ONLY);
Mike Snitzer44feb382012-10-12 21:02:10 +01001107 dm_cell_error(cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001108 break;
1109 }
1110}
1111
1112static void process_bio(struct thin_c *tc, struct bio *bio)
1113{
1114 int r;
1115 dm_block_t block = get_bio_block(tc, bio);
Mike Snitzera24c2562012-06-03 00:30:00 +01001116 struct dm_bio_prison_cell *cell;
Mike Snitzer44feb382012-10-12 21:02:10 +01001117 struct dm_cell_key key;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001118 struct dm_thin_lookup_result lookup_result;
1119
1120 /*
1121 * If cell is already occupied, then the block is already
1122 * being provisioned so we have nothing further to do here.
1123 */
1124 build_virtual_key(tc->td, block, &key);
Mike Snitzer44feb382012-10-12 21:02:10 +01001125 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell))
Joe Thornber991d9fa2011-10-31 20:21:18 +00001126 return;
1127
1128 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1129 switch (r) {
1130 case 0:
Joe Thornbere8088072012-12-21 20:23:31 +00001131 if (lookup_result.shared) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001132 process_shared_bio(tc, bio, block, &lookup_result);
Joe Thornberf286ba02012-12-21 20:23:33 +00001133 cell_defer_no_holder(tc, cell);
Joe Thornbere8088072012-12-21 20:23:31 +00001134 } else {
1135 inc_all_io_entry(tc->pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001136 cell_defer_no_holder(tc, cell);
Joe Thornbere8088072012-12-21 20:23:31 +00001137
Joe Thornber991d9fa2011-10-31 20:21:18 +00001138 remap_and_issue(tc, bio, lookup_result.block);
Joe Thornbere8088072012-12-21 20:23:31 +00001139 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001140 break;
1141
1142 case -ENODATA:
Joe Thornber2dd9c252012-03-28 18:41:28 +01001143 if (bio_data_dir(bio) == READ && tc->origin_dev) {
Joe Thornbere8088072012-12-21 20:23:31 +00001144 inc_all_io_entry(tc->pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001145 cell_defer_no_holder(tc, cell);
Joe Thornbere8088072012-12-21 20:23:31 +00001146
Joe Thornber2dd9c252012-03-28 18:41:28 +01001147 remap_to_origin_and_issue(tc, bio);
1148 } else
1149 provision_block(tc, bio, block, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001150 break;
1151
1152 default:
Mike Snitzerc3977412012-12-21 20:23:34 +00001153 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1154 __func__, r);
Joe Thornberf286ba02012-12-21 20:23:33 +00001155 cell_defer_no_holder(tc, cell);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001156 bio_io_error(bio);
1157 break;
1158 }
1159}
1160
Joe Thornbere49e5822012-07-27 15:08:16 +01001161static void process_bio_read_only(struct thin_c *tc, struct bio *bio)
1162{
1163 int r;
1164 int rw = bio_data_dir(bio);
1165 dm_block_t block = get_bio_block(tc, bio);
1166 struct dm_thin_lookup_result lookup_result;
1167
1168 r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
1169 switch (r) {
1170 case 0:
1171 if (lookup_result.shared && (rw == WRITE) && bio->bi_size)
1172 bio_io_error(bio);
Joe Thornbere8088072012-12-21 20:23:31 +00001173 else {
1174 inc_all_io_entry(tc->pool, bio);
Joe Thornbere49e5822012-07-27 15:08:16 +01001175 remap_and_issue(tc, bio, lookup_result.block);
Joe Thornbere8088072012-12-21 20:23:31 +00001176 }
Joe Thornbere49e5822012-07-27 15:08:16 +01001177 break;
1178
1179 case -ENODATA:
1180 if (rw != READ) {
1181 bio_io_error(bio);
1182 break;
1183 }
1184
1185 if (tc->origin_dev) {
Joe Thornbere8088072012-12-21 20:23:31 +00001186 inc_all_io_entry(tc->pool, bio);
Joe Thornbere49e5822012-07-27 15:08:16 +01001187 remap_to_origin_and_issue(tc, bio);
1188 break;
1189 }
1190
1191 zero_fill_bio(bio);
1192 bio_endio(bio, 0);
1193 break;
1194
1195 default:
Mike Snitzerc3977412012-12-21 20:23:34 +00001196 DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
1197 __func__, r);
Joe Thornbere49e5822012-07-27 15:08:16 +01001198 bio_io_error(bio);
1199 break;
1200 }
1201}
1202
1203static void process_bio_fail(struct thin_c *tc, struct bio *bio)
1204{
1205 bio_io_error(bio);
1206}
1207
Joe Thornber905e51b2012-03-28 18:41:27 +01001208static int need_commit_due_to_time(struct pool *pool)
1209{
1210 return jiffies < pool->last_commit_jiffies ||
1211 jiffies > pool->last_commit_jiffies + COMMIT_PERIOD;
1212}
1213
Joe Thornber991d9fa2011-10-31 20:21:18 +00001214static void process_deferred_bios(struct pool *pool)
1215{
1216 unsigned long flags;
1217 struct bio *bio;
1218 struct bio_list bios;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001219
1220 bio_list_init(&bios);
1221
1222 spin_lock_irqsave(&pool->lock, flags);
1223 bio_list_merge(&bios, &pool->deferred_bios);
1224 bio_list_init(&pool->deferred_bios);
1225 spin_unlock_irqrestore(&pool->lock, flags);
1226
1227 while ((bio = bio_list_pop(&bios))) {
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001228 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbereb2aa482012-03-28 18:41:28 +01001229 struct thin_c *tc = h->tc;
1230
Joe Thornber991d9fa2011-10-31 20:21:18 +00001231 /*
1232 * If we've got no free new_mapping structs, and processing
1233 * this bio might require one, we pause until there are some
1234 * prepared mappings to process.
1235 */
1236 if (ensure_next_mapping(pool)) {
1237 spin_lock_irqsave(&pool->lock, flags);
1238 bio_list_merge(&pool->deferred_bios, &bios);
1239 spin_unlock_irqrestore(&pool->lock, flags);
1240
1241 break;
1242 }
Joe Thornber104655f2012-03-28 18:41:28 +01001243
1244 if (bio->bi_rw & REQ_DISCARD)
Joe Thornbere49e5822012-07-27 15:08:16 +01001245 pool->process_discard(tc, bio);
Joe Thornber104655f2012-03-28 18:41:28 +01001246 else
Joe Thornbere49e5822012-07-27 15:08:16 +01001247 pool->process_bio(tc, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001248 }
1249
1250 /*
1251 * If there are any deferred flush bios, we must commit
1252 * the metadata before issuing them.
1253 */
1254 bio_list_init(&bios);
1255 spin_lock_irqsave(&pool->lock, flags);
1256 bio_list_merge(&bios, &pool->deferred_flush_bios);
1257 bio_list_init(&pool->deferred_flush_bios);
1258 spin_unlock_irqrestore(&pool->lock, flags);
1259
Joe Thornber905e51b2012-03-28 18:41:27 +01001260 if (bio_list_empty(&bios) && !need_commit_due_to_time(pool))
Joe Thornber991d9fa2011-10-31 20:21:18 +00001261 return;
1262
Joe Thornbere49e5822012-07-27 15:08:16 +01001263 if (commit_or_fallback(pool)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001264 while ((bio = bio_list_pop(&bios)))
1265 bio_io_error(bio);
1266 return;
1267 }
Joe Thornber905e51b2012-03-28 18:41:27 +01001268 pool->last_commit_jiffies = jiffies;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001269
1270 while ((bio = bio_list_pop(&bios)))
1271 generic_make_request(bio);
1272}
1273
1274static void do_worker(struct work_struct *ws)
1275{
1276 struct pool *pool = container_of(ws, struct pool, worker);
1277
Joe Thornbere49e5822012-07-27 15:08:16 +01001278 process_prepared(pool, &pool->prepared_mappings, &pool->process_prepared_mapping);
1279 process_prepared(pool, &pool->prepared_discards, &pool->process_prepared_discard);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001280 process_deferred_bios(pool);
1281}
1282
Joe Thornber905e51b2012-03-28 18:41:27 +01001283/*
1284 * We want to commit periodically so that not too much
1285 * unwritten data builds up.
1286 */
1287static void do_waker(struct work_struct *ws)
1288{
1289 struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker);
1290 wake_worker(pool);
1291 queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD);
1292}
1293
Joe Thornber991d9fa2011-10-31 20:21:18 +00001294/*----------------------------------------------------------------*/
1295
Joe Thornbere49e5822012-07-27 15:08:16 +01001296static enum pool_mode get_pool_mode(struct pool *pool)
1297{
1298 return pool->pf.mode;
1299}
1300
1301static void set_pool_mode(struct pool *pool, enum pool_mode mode)
1302{
1303 int r;
1304
1305 pool->pf.mode = mode;
1306
1307 switch (mode) {
1308 case PM_FAIL:
1309 DMERR("switching pool to failure mode");
1310 pool->process_bio = process_bio_fail;
1311 pool->process_discard = process_bio_fail;
1312 pool->process_prepared_mapping = process_prepared_mapping_fail;
1313 pool->process_prepared_discard = process_prepared_discard_fail;
1314 break;
1315
1316 case PM_READ_ONLY:
1317 DMERR("switching pool to read-only mode");
1318 r = dm_pool_abort_metadata(pool->pmd);
1319 if (r) {
1320 DMERR("aborting transaction failed");
1321 set_pool_mode(pool, PM_FAIL);
1322 } else {
1323 dm_pool_metadata_read_only(pool->pmd);
1324 pool->process_bio = process_bio_read_only;
1325 pool->process_discard = process_discard;
1326 pool->process_prepared_mapping = process_prepared_mapping_fail;
1327 pool->process_prepared_discard = process_prepared_discard_passdown;
1328 }
1329 break;
1330
1331 case PM_WRITE:
1332 pool->process_bio = process_bio;
1333 pool->process_discard = process_discard;
1334 pool->process_prepared_mapping = process_prepared_mapping;
1335 pool->process_prepared_discard = process_prepared_discard;
1336 break;
1337 }
1338}
1339
1340/*----------------------------------------------------------------*/
1341
Joe Thornber991d9fa2011-10-31 20:21:18 +00001342/*
1343 * Mapping functions.
1344 */
1345
1346/*
1347 * Called only while mapping a thin bio to hand it over to the workqueue.
1348 */
1349static void thin_defer_bio(struct thin_c *tc, struct bio *bio)
1350{
1351 unsigned long flags;
1352 struct pool *pool = tc->pool;
1353
1354 spin_lock_irqsave(&pool->lock, flags);
1355 bio_list_add(&pool->deferred_bios, bio);
1356 spin_unlock_irqrestore(&pool->lock, flags);
1357
1358 wake_worker(pool);
1359}
1360
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001361static void thin_hook_bio(struct thin_c *tc, struct bio *bio)
Joe Thornbereb2aa482012-03-28 18:41:28 +01001362{
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001363 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbereb2aa482012-03-28 18:41:28 +01001364
1365 h->tc = tc;
1366 h->shared_read_entry = NULL;
Joe Thornbere8088072012-12-21 20:23:31 +00001367 h->all_io_entry = NULL;
Joe Thornbereb2aa482012-03-28 18:41:28 +01001368 h->overwrite_mapping = NULL;
Joe Thornbereb2aa482012-03-28 18:41:28 +01001369}
1370
Joe Thornber991d9fa2011-10-31 20:21:18 +00001371/*
1372 * Non-blocking function called from the thin target's map function.
1373 */
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00001374static int thin_bio_map(struct dm_target *ti, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001375{
1376 int r;
1377 struct thin_c *tc = ti->private;
1378 dm_block_t block = get_bio_block(tc, bio);
1379 struct dm_thin_device *td = tc->td;
1380 struct dm_thin_lookup_result result;
Joe Thornbere8088072012-12-21 20:23:31 +00001381 struct dm_bio_prison_cell *cell1, *cell2;
1382 struct dm_cell_key key;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001383
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00001384 thin_hook_bio(tc, bio);
Joe Thornbere49e5822012-07-27 15:08:16 +01001385
1386 if (get_pool_mode(tc->pool) == PM_FAIL) {
1387 bio_io_error(bio);
1388 return DM_MAPIO_SUBMITTED;
1389 }
1390
Joe Thornber104655f2012-03-28 18:41:28 +01001391 if (bio->bi_rw & (REQ_DISCARD | REQ_FLUSH | REQ_FUA)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001392 thin_defer_bio(tc, bio);
1393 return DM_MAPIO_SUBMITTED;
1394 }
1395
1396 r = dm_thin_find_block(td, block, 0, &result);
1397
1398 /*
1399 * Note that we defer readahead too.
1400 */
1401 switch (r) {
1402 case 0:
1403 if (unlikely(result.shared)) {
1404 /*
1405 * We have a race condition here between the
1406 * result.shared value returned by the lookup and
1407 * snapshot creation, which may cause new
1408 * sharing.
1409 *
1410 * To avoid this always quiesce the origin before
1411 * taking the snap. You want to do this anyway to
1412 * ensure a consistent application view
1413 * (i.e. lockfs).
1414 *
1415 * More distant ancestors are irrelevant. The
1416 * shared flag will be set in their case.
1417 */
1418 thin_defer_bio(tc, bio);
Joe Thornbere8088072012-12-21 20:23:31 +00001419 return DM_MAPIO_SUBMITTED;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001420 }
Joe Thornbere8088072012-12-21 20:23:31 +00001421
1422 build_virtual_key(tc->td, block, &key);
1423 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell1))
1424 return DM_MAPIO_SUBMITTED;
1425
1426 build_data_key(tc->td, result.block, &key);
1427 if (dm_bio_detain(tc->pool->prison, &key, bio, &cell2)) {
Joe Thornberf286ba02012-12-21 20:23:33 +00001428 cell_defer_no_holder(tc, cell1);
Joe Thornbere8088072012-12-21 20:23:31 +00001429 return DM_MAPIO_SUBMITTED;
1430 }
1431
1432 inc_all_io_entry(tc->pool, bio);
Joe Thornberf286ba02012-12-21 20:23:33 +00001433 cell_defer_no_holder(tc, cell2);
1434 cell_defer_no_holder(tc, cell1);
Joe Thornbere8088072012-12-21 20:23:31 +00001435
1436 remap(tc, bio, result.block);
1437 return DM_MAPIO_REMAPPED;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001438
1439 case -ENODATA:
Joe Thornbere49e5822012-07-27 15:08:16 +01001440 if (get_pool_mode(tc->pool) == PM_READ_ONLY) {
1441 /*
1442 * This block isn't provisioned, and we have no way
1443 * of doing so. Just error it.
1444 */
1445 bio_io_error(bio);
Joe Thornber2aab3852012-12-21 20:23:33 +00001446 return DM_MAPIO_SUBMITTED;
Joe Thornbere49e5822012-07-27 15:08:16 +01001447 }
1448 /* fall through */
1449
1450 case -EWOULDBLOCK:
Joe Thornber991d9fa2011-10-31 20:21:18 +00001451 /*
1452 * In future, the failed dm_thin_find_block above could
1453 * provide the hint to load the metadata into cache.
1454 */
Joe Thornber991d9fa2011-10-31 20:21:18 +00001455 thin_defer_bio(tc, bio);
Joe Thornber2aab3852012-12-21 20:23:33 +00001456 return DM_MAPIO_SUBMITTED;
Joe Thornbere49e5822012-07-27 15:08:16 +01001457
1458 default:
1459 /*
1460 * Must always call bio_io_error on failure.
1461 * dm_thin_find_block can fail with -EINVAL if the
1462 * pool is switched to fail-io mode.
1463 */
1464 bio_io_error(bio);
Joe Thornber2aab3852012-12-21 20:23:33 +00001465 return DM_MAPIO_SUBMITTED;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001466 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001467}
1468
1469static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
1470{
1471 int r;
1472 unsigned long flags;
1473 struct pool_c *pt = container_of(cb, struct pool_c, callbacks);
1474
1475 spin_lock_irqsave(&pt->pool->lock, flags);
1476 r = !bio_list_empty(&pt->pool->retry_on_resume_list);
1477 spin_unlock_irqrestore(&pt->pool->lock, flags);
1478
1479 if (!r) {
1480 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
1481 r = bdi_congested(&q->backing_dev_info, bdi_bits);
1482 }
1483
1484 return r;
1485}
1486
1487static void __requeue_bios(struct pool *pool)
1488{
1489 bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list);
1490 bio_list_init(&pool->retry_on_resume_list);
1491}
1492
1493/*----------------------------------------------------------------
1494 * Binding of control targets to a pool object
1495 *--------------------------------------------------------------*/
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001496static bool data_dev_supports_discard(struct pool_c *pt)
1497{
1498 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
1499
1500 return q && blk_queue_discard(q);
1501}
1502
1503/*
1504 * If discard_passdown was enabled verify that the data device
Mike Snitzer0424caa2012-09-26 23:45:47 +01001505 * supports discards. Disable discard_passdown if not.
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001506 */
Mike Snitzer0424caa2012-09-26 23:45:47 +01001507static void disable_passdown_if_not_supported(struct pool_c *pt)
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001508{
Mike Snitzer0424caa2012-09-26 23:45:47 +01001509 struct pool *pool = pt->pool;
1510 struct block_device *data_bdev = pt->data_dev->bdev;
1511 struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits;
1512 sector_t block_size = pool->sectors_per_block << SECTOR_SHIFT;
1513 const char *reason = NULL;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001514 char buf[BDEVNAME_SIZE];
1515
Mike Snitzer0424caa2012-09-26 23:45:47 +01001516 if (!pt->adjusted_pf.discard_passdown)
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001517 return;
1518
Mike Snitzer0424caa2012-09-26 23:45:47 +01001519 if (!data_dev_supports_discard(pt))
1520 reason = "discard unsupported";
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001521
Mike Snitzer0424caa2012-09-26 23:45:47 +01001522 else if (data_limits->max_discard_sectors < pool->sectors_per_block)
1523 reason = "max discard sectors smaller than a block";
1524
1525 else if (data_limits->discard_granularity > block_size)
1526 reason = "discard granularity larger than a block";
1527
1528 else if (block_size & (data_limits->discard_granularity - 1))
1529 reason = "discard granularity not a factor of block size";
1530
1531 if (reason) {
1532 DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev, buf), reason);
1533 pt->adjusted_pf.discard_passdown = false;
1534 }
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001535}
1536
Joe Thornber991d9fa2011-10-31 20:21:18 +00001537static int bind_control_target(struct pool *pool, struct dm_target *ti)
1538{
1539 struct pool_c *pt = ti->private;
1540
Joe Thornbere49e5822012-07-27 15:08:16 +01001541 /*
1542 * We want to make sure that degraded pools are never upgraded.
1543 */
1544 enum pool_mode old_mode = pool->pf.mode;
Mike Snitzer0424caa2012-09-26 23:45:47 +01001545 enum pool_mode new_mode = pt->adjusted_pf.mode;
Joe Thornbere49e5822012-07-27 15:08:16 +01001546
1547 if (old_mode > new_mode)
1548 new_mode = old_mode;
1549
Joe Thornber991d9fa2011-10-31 20:21:18 +00001550 pool->ti = ti;
1551 pool->low_water_blocks = pt->low_water_blocks;
Mike Snitzer0424caa2012-09-26 23:45:47 +01001552 pool->pf = pt->adjusted_pf;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001553
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001554 set_pool_mode(pool, new_mode);
Mike Snitzerf4026932012-05-19 01:01:01 +01001555
Joe Thornber991d9fa2011-10-31 20:21:18 +00001556 return 0;
1557}
1558
1559static void unbind_control_target(struct pool *pool, struct dm_target *ti)
1560{
1561 if (pool->ti == ti)
1562 pool->ti = NULL;
1563}
1564
1565/*----------------------------------------------------------------
1566 * Pool creation
1567 *--------------------------------------------------------------*/
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001568/* Initialize pool features. */
1569static void pool_features_init(struct pool_features *pf)
1570{
Joe Thornbere49e5822012-07-27 15:08:16 +01001571 pf->mode = PM_WRITE;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001572 pf->zero_new_blocks = true;
1573 pf->discard_enabled = true;
1574 pf->discard_passdown = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001575}
1576
Joe Thornber991d9fa2011-10-31 20:21:18 +00001577static void __pool_destroy(struct pool *pool)
1578{
1579 __pool_table_remove(pool);
1580
1581 if (dm_pool_metadata_close(pool->pmd) < 0)
1582 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
1583
Mike Snitzer44feb382012-10-12 21:02:10 +01001584 dm_bio_prison_destroy(pool->prison);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001585 dm_kcopyd_client_destroy(pool->copier);
1586
1587 if (pool->wq)
1588 destroy_workqueue(pool->wq);
1589
1590 if (pool->next_mapping)
1591 mempool_free(pool->next_mapping, pool->mapping_pool);
1592 mempool_destroy(pool->mapping_pool);
Mike Snitzer44feb382012-10-12 21:02:10 +01001593 dm_deferred_set_destroy(pool->shared_read_ds);
1594 dm_deferred_set_destroy(pool->all_io_ds);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001595 kfree(pool);
1596}
1597
Mike Snitzera24c2562012-06-03 00:30:00 +01001598static struct kmem_cache *_new_mapping_cache;
Mike Snitzera24c2562012-06-03 00:30:00 +01001599
Joe Thornber991d9fa2011-10-31 20:21:18 +00001600static struct pool *pool_create(struct mapped_device *pool_md,
1601 struct block_device *metadata_dev,
Joe Thornbere49e5822012-07-27 15:08:16 +01001602 unsigned long block_size,
1603 int read_only, char **error)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001604{
1605 int r;
1606 void *err_p;
1607 struct pool *pool;
1608 struct dm_pool_metadata *pmd;
Joe Thornbere49e5822012-07-27 15:08:16 +01001609 bool format_device = read_only ? false : true;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001610
Joe Thornbere49e5822012-07-27 15:08:16 +01001611 pmd = dm_pool_metadata_open(metadata_dev, block_size, format_device);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001612 if (IS_ERR(pmd)) {
1613 *error = "Error creating metadata object";
1614 return (struct pool *)pmd;
1615 }
1616
1617 pool = kmalloc(sizeof(*pool), GFP_KERNEL);
1618 if (!pool) {
1619 *error = "Error allocating memory for pool";
1620 err_p = ERR_PTR(-ENOMEM);
1621 goto bad_pool;
1622 }
1623
1624 pool->pmd = pmd;
1625 pool->sectors_per_block = block_size;
Mikulas Patockaf9a8e0c2012-07-27 15:08:03 +01001626 if (block_size & (block_size - 1))
1627 pool->sectors_per_block_shift = -1;
1628 else
1629 pool->sectors_per_block_shift = __ffs(block_size);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001630 pool->low_water_blocks = 0;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001631 pool_features_init(&pool->pf);
Mike Snitzer44feb382012-10-12 21:02:10 +01001632 pool->prison = dm_bio_prison_create(PRISON_CELLS);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001633 if (!pool->prison) {
1634 *error = "Error creating pool's bio prison";
1635 err_p = ERR_PTR(-ENOMEM);
1636 goto bad_prison;
1637 }
1638
1639 pool->copier = dm_kcopyd_client_create();
1640 if (IS_ERR(pool->copier)) {
1641 r = PTR_ERR(pool->copier);
1642 *error = "Error creating pool's kcopyd client";
1643 err_p = ERR_PTR(r);
1644 goto bad_kcopyd_client;
1645 }
1646
1647 /*
1648 * Create singlethreaded workqueue that will service all devices
1649 * that use this metadata.
1650 */
1651 pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
1652 if (!pool->wq) {
1653 *error = "Error creating pool's workqueue";
1654 err_p = ERR_PTR(-ENOMEM);
1655 goto bad_wq;
1656 }
1657
1658 INIT_WORK(&pool->worker, do_worker);
Joe Thornber905e51b2012-03-28 18:41:27 +01001659 INIT_DELAYED_WORK(&pool->waker, do_waker);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001660 spin_lock_init(&pool->lock);
1661 bio_list_init(&pool->deferred_bios);
1662 bio_list_init(&pool->deferred_flush_bios);
1663 INIT_LIST_HEAD(&pool->prepared_mappings);
Joe Thornber104655f2012-03-28 18:41:28 +01001664 INIT_LIST_HEAD(&pool->prepared_discards);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001665 pool->low_water_triggered = 0;
1666 pool->no_free_space = 0;
1667 bio_list_init(&pool->retry_on_resume_list);
Mike Snitzer44feb382012-10-12 21:02:10 +01001668
1669 pool->shared_read_ds = dm_deferred_set_create();
1670 if (!pool->shared_read_ds) {
1671 *error = "Error creating pool's shared read deferred set";
1672 err_p = ERR_PTR(-ENOMEM);
1673 goto bad_shared_read_ds;
1674 }
1675
1676 pool->all_io_ds = dm_deferred_set_create();
1677 if (!pool->all_io_ds) {
1678 *error = "Error creating pool's all io deferred set";
1679 err_p = ERR_PTR(-ENOMEM);
1680 goto bad_all_io_ds;
1681 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001682
1683 pool->next_mapping = NULL;
Mike Snitzera24c2562012-06-03 00:30:00 +01001684 pool->mapping_pool = mempool_create_slab_pool(MAPPING_POOL_SIZE,
1685 _new_mapping_cache);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001686 if (!pool->mapping_pool) {
1687 *error = "Error creating pool's mapping mempool";
1688 err_p = ERR_PTR(-ENOMEM);
1689 goto bad_mapping_pool;
1690 }
1691
Joe Thornber991d9fa2011-10-31 20:21:18 +00001692 pool->ref_count = 1;
Joe Thornber905e51b2012-03-28 18:41:27 +01001693 pool->last_commit_jiffies = jiffies;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001694 pool->pool_md = pool_md;
1695 pool->md_dev = metadata_dev;
1696 __pool_table_insert(pool);
1697
1698 return pool;
1699
Joe Thornber991d9fa2011-10-31 20:21:18 +00001700bad_mapping_pool:
Mike Snitzer44feb382012-10-12 21:02:10 +01001701 dm_deferred_set_destroy(pool->all_io_ds);
1702bad_all_io_ds:
1703 dm_deferred_set_destroy(pool->shared_read_ds);
1704bad_shared_read_ds:
Joe Thornber991d9fa2011-10-31 20:21:18 +00001705 destroy_workqueue(pool->wq);
1706bad_wq:
1707 dm_kcopyd_client_destroy(pool->copier);
1708bad_kcopyd_client:
Mike Snitzer44feb382012-10-12 21:02:10 +01001709 dm_bio_prison_destroy(pool->prison);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001710bad_prison:
1711 kfree(pool);
1712bad_pool:
1713 if (dm_pool_metadata_close(pmd))
1714 DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
1715
1716 return err_p;
1717}
1718
1719static void __pool_inc(struct pool *pool)
1720{
1721 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
1722 pool->ref_count++;
1723}
1724
1725static void __pool_dec(struct pool *pool)
1726{
1727 BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
1728 BUG_ON(!pool->ref_count);
1729 if (!--pool->ref_count)
1730 __pool_destroy(pool);
1731}
1732
1733static struct pool *__pool_find(struct mapped_device *pool_md,
1734 struct block_device *metadata_dev,
Joe Thornbere49e5822012-07-27 15:08:16 +01001735 unsigned long block_size, int read_only,
1736 char **error, int *created)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001737{
1738 struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev);
1739
1740 if (pool) {
Mike Snitzerf09996c2012-07-27 15:07:59 +01001741 if (pool->pool_md != pool_md) {
1742 *error = "metadata device already in use by a pool";
Joe Thornber991d9fa2011-10-31 20:21:18 +00001743 return ERR_PTR(-EBUSY);
Mike Snitzerf09996c2012-07-27 15:07:59 +01001744 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001745 __pool_inc(pool);
1746
1747 } else {
1748 pool = __pool_table_lookup(pool_md);
1749 if (pool) {
Mike Snitzerf09996c2012-07-27 15:07:59 +01001750 if (pool->md_dev != metadata_dev) {
1751 *error = "different pool cannot replace a pool";
Joe Thornber991d9fa2011-10-31 20:21:18 +00001752 return ERR_PTR(-EINVAL);
Mike Snitzerf09996c2012-07-27 15:07:59 +01001753 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001754 __pool_inc(pool);
1755
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001756 } else {
Joe Thornbere49e5822012-07-27 15:08:16 +01001757 pool = pool_create(pool_md, metadata_dev, block_size, read_only, error);
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001758 *created = 1;
1759 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001760 }
1761
1762 return pool;
1763}
1764
1765/*----------------------------------------------------------------
1766 * Pool target methods
1767 *--------------------------------------------------------------*/
1768static void pool_dtr(struct dm_target *ti)
1769{
1770 struct pool_c *pt = ti->private;
1771
1772 mutex_lock(&dm_thin_pool_table.mutex);
1773
1774 unbind_control_target(pt->pool, ti);
1775 __pool_dec(pt->pool);
1776 dm_put_device(ti, pt->metadata_dev);
1777 dm_put_device(ti, pt->data_dev);
1778 kfree(pt);
1779
1780 mutex_unlock(&dm_thin_pool_table.mutex);
1781}
1782
Joe Thornber991d9fa2011-10-31 20:21:18 +00001783static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf,
1784 struct dm_target *ti)
1785{
1786 int r;
1787 unsigned argc;
1788 const char *arg_name;
1789
1790 static struct dm_arg _args[] = {
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001791 {0, 3, "Invalid number of pool feature arguments"},
Joe Thornber991d9fa2011-10-31 20:21:18 +00001792 };
1793
1794 /*
1795 * No feature arguments supplied.
1796 */
1797 if (!as->argc)
1798 return 0;
1799
1800 r = dm_read_arg_group(_args, as, &argc, &ti->error);
1801 if (r)
1802 return -EINVAL;
1803
1804 while (argc && !r) {
1805 arg_name = dm_shift_arg(as);
1806 argc--;
1807
Joe Thornbere49e5822012-07-27 15:08:16 +01001808 if (!strcasecmp(arg_name, "skip_block_zeroing"))
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001809 pf->zero_new_blocks = false;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001810
Joe Thornbere49e5822012-07-27 15:08:16 +01001811 else if (!strcasecmp(arg_name, "ignore_discard"))
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001812 pf->discard_enabled = false;
Joe Thornbere49e5822012-07-27 15:08:16 +01001813
1814 else if (!strcasecmp(arg_name, "no_discard_passdown"))
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001815 pf->discard_passdown = false;
Joe Thornbere49e5822012-07-27 15:08:16 +01001816
1817 else if (!strcasecmp(arg_name, "read_only"))
1818 pf->mode = PM_READ_ONLY;
1819
1820 else {
1821 ti->error = "Unrecognised pool feature requested";
1822 r = -EINVAL;
1823 break;
1824 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001825 }
1826
1827 return r;
1828}
1829
1830/*
1831 * thin-pool <metadata dev> <data dev>
1832 * <data block size (sectors)>
1833 * <low water mark (blocks)>
1834 * [<#feature args> [<arg>]*]
1835 *
1836 * Optional feature arguments are:
1837 * skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001838 * ignore_discard: disable discard
1839 * no_discard_passdown: don't pass discards down to the data device
Joe Thornber991d9fa2011-10-31 20:21:18 +00001840 */
1841static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv)
1842{
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001843 int r, pool_created = 0;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001844 struct pool_c *pt;
1845 struct pool *pool;
1846 struct pool_features pf;
1847 struct dm_arg_set as;
1848 struct dm_dev *data_dev;
1849 unsigned long block_size;
1850 dm_block_t low_water_blocks;
1851 struct dm_dev *metadata_dev;
1852 sector_t metadata_dev_size;
Mike Snitzerc4a69ec2012-03-28 18:41:28 +01001853 char b[BDEVNAME_SIZE];
Joe Thornber991d9fa2011-10-31 20:21:18 +00001854
1855 /*
1856 * FIXME Remove validation from scope of lock.
1857 */
1858 mutex_lock(&dm_thin_pool_table.mutex);
1859
1860 if (argc < 4) {
1861 ti->error = "Invalid argument count";
1862 r = -EINVAL;
1863 goto out_unlock;
1864 }
1865 as.argc = argc;
1866 as.argv = argv;
1867
1868 r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &metadata_dev);
1869 if (r) {
1870 ti->error = "Error opening metadata block device";
1871 goto out_unlock;
1872 }
1873
1874 metadata_dev_size = i_size_read(metadata_dev->bdev->bd_inode) >> SECTOR_SHIFT;
Mike Snitzerc4a69ec2012-03-28 18:41:28 +01001875 if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING)
1876 DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.",
1877 bdevname(metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001878
1879 r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev);
1880 if (r) {
1881 ti->error = "Error getting data device";
1882 goto out_metadata;
1883 }
1884
1885 if (kstrtoul(argv[2], 10, &block_size) || !block_size ||
1886 block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
1887 block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01001888 block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00001889 ti->error = "Invalid block size";
1890 r = -EINVAL;
1891 goto out;
1892 }
1893
1894 if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) {
1895 ti->error = "Invalid low water mark";
1896 r = -EINVAL;
1897 goto out;
1898 }
1899
1900 /*
1901 * Set default pool features.
1902 */
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001903 pool_features_init(&pf);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001904
1905 dm_consume_args(&as, 4);
1906 r = parse_pool_features(&as, &pf, ti);
1907 if (r)
1908 goto out;
1909
1910 pt = kzalloc(sizeof(*pt), GFP_KERNEL);
1911 if (!pt) {
1912 r = -ENOMEM;
1913 goto out;
1914 }
1915
1916 pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev,
Joe Thornbere49e5822012-07-27 15:08:16 +01001917 block_size, pf.mode == PM_READ_ONLY, &ti->error, &pool_created);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001918 if (IS_ERR(pool)) {
1919 r = PTR_ERR(pool);
1920 goto out_free_pt;
1921 }
1922
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001923 /*
1924 * 'pool_created' reflects whether this is the first table load.
1925 * Top level discard support is not allowed to be changed after
1926 * initial load. This would require a pool reload to trigger thin
1927 * device changes.
1928 */
1929 if (!pool_created && pf.discard_enabled != pool->pf.discard_enabled) {
1930 ti->error = "Discard support cannot be disabled once enabled";
1931 r = -EINVAL;
1932 goto out_flags_changed;
1933 }
1934
Joe Thornber991d9fa2011-10-31 20:21:18 +00001935 pt->pool = pool;
1936 pt->ti = ti;
1937 pt->metadata_dev = metadata_dev;
1938 pt->data_dev = data_dev;
1939 pt->low_water_blocks = low_water_blocks;
Mike Snitzer0424caa2012-09-26 23:45:47 +01001940 pt->adjusted_pf = pt->requested_pf = pf;
Joe Thornber991d9fa2011-10-31 20:21:18 +00001941 ti->num_flush_requests = 1;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001942
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001943 /*
1944 * Only need to enable discards if the pool should pass
1945 * them down to the data device. The thin device's discard
1946 * processing will cause mappings to be removed from the btree.
1947 */
1948 if (pf.discard_enabled && pf.discard_passdown) {
1949 ti->num_discard_requests = 1;
Mike Snitzer9bc142d2012-09-26 23:45:46 +01001950
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001951 /*
1952 * Setting 'discards_supported' circumvents the normal
1953 * stacking of discard limits (this keeps the pool and
1954 * thin devices' discard limits consistent).
1955 */
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01001956 ti->discards_supported = true;
Mike Snitzer307615a2012-09-26 23:45:39 +01001957 ti->discard_zeroes_data_unsupported = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001958 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00001959 ti->private = pt;
1960
1961 pt->callbacks.congested_fn = pool_is_congested;
1962 dm_table_add_target_callbacks(ti->table, &pt->callbacks);
1963
1964 mutex_unlock(&dm_thin_pool_table.mutex);
1965
1966 return 0;
1967
Joe Thornber67e2e2b2012-03-28 18:41:29 +01001968out_flags_changed:
1969 __pool_dec(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00001970out_free_pt:
1971 kfree(pt);
1972out:
1973 dm_put_device(ti, data_dev);
1974out_metadata:
1975 dm_put_device(ti, metadata_dev);
1976out_unlock:
1977 mutex_unlock(&dm_thin_pool_table.mutex);
1978
1979 return r;
1980}
1981
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00001982static int pool_map(struct dm_target *ti, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +00001983{
1984 int r;
1985 struct pool_c *pt = ti->private;
1986 struct pool *pool = pt->pool;
1987 unsigned long flags;
1988
1989 /*
1990 * As this is a singleton target, ti->begin is always zero.
1991 */
1992 spin_lock_irqsave(&pool->lock, flags);
1993 bio->bi_bdev = pt->data_dev->bdev;
1994 r = DM_MAPIO_REMAPPED;
1995 spin_unlock_irqrestore(&pool->lock, flags);
1996
1997 return r;
1998}
1999
2000/*
2001 * Retrieves the number of blocks of the data device from
2002 * the superblock and compares it to the actual device size,
2003 * thus resizing the data device in case it has grown.
2004 *
2005 * This both copes with opening preallocated data devices in the ctr
2006 * being followed by a resume
2007 * -and-
2008 * calling the resume method individually after userspace has
2009 * grown the data device in reaction to a table event.
2010 */
2011static int pool_preresume(struct dm_target *ti)
2012{
2013 int r;
2014 struct pool_c *pt = ti->private;
2015 struct pool *pool = pt->pool;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002016 sector_t data_size = ti->len;
2017 dm_block_t sb_data_size;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002018
2019 /*
2020 * Take control of the pool object.
2021 */
2022 r = bind_control_target(pool, ti);
2023 if (r)
2024 return r;
2025
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002026 (void) sector_div(data_size, pool->sectors_per_block);
2027
Joe Thornber991d9fa2011-10-31 20:21:18 +00002028 r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
2029 if (r) {
2030 DMERR("failed to retrieve data device size");
2031 return r;
2032 }
2033
2034 if (data_size < sb_data_size) {
2035 DMERR("pool target too small, is %llu blocks (expected %llu)",
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002036 (unsigned long long)data_size, sb_data_size);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002037 return -EINVAL;
2038
2039 } else if (data_size > sb_data_size) {
2040 r = dm_pool_resize_data_dev(pool->pmd, data_size);
2041 if (r) {
2042 DMERR("failed to resize data device");
Joe Thornbere49e5822012-07-27 15:08:16 +01002043 /* FIXME Stricter than necessary: Rollback transaction instead here */
2044 set_pool_mode(pool, PM_READ_ONLY);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002045 return r;
2046 }
2047
Joe Thornbere49e5822012-07-27 15:08:16 +01002048 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002049 }
2050
2051 return 0;
2052}
2053
2054static void pool_resume(struct dm_target *ti)
2055{
2056 struct pool_c *pt = ti->private;
2057 struct pool *pool = pt->pool;
2058 unsigned long flags;
2059
2060 spin_lock_irqsave(&pool->lock, flags);
2061 pool->low_water_triggered = 0;
2062 pool->no_free_space = 0;
2063 __requeue_bios(pool);
2064 spin_unlock_irqrestore(&pool->lock, flags);
2065
Joe Thornber905e51b2012-03-28 18:41:27 +01002066 do_waker(&pool->waker.work);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002067}
2068
2069static void pool_postsuspend(struct dm_target *ti)
2070{
Joe Thornber991d9fa2011-10-31 20:21:18 +00002071 struct pool_c *pt = ti->private;
2072 struct pool *pool = pt->pool;
2073
Joe Thornber905e51b2012-03-28 18:41:27 +01002074 cancel_delayed_work(&pool->waker);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002075 flush_workqueue(pool->wq);
Joe Thornbere49e5822012-07-27 15:08:16 +01002076 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002077}
2078
2079static int check_arg_count(unsigned argc, unsigned args_required)
2080{
2081 if (argc != args_required) {
2082 DMWARN("Message received with %u arguments instead of %u.",
2083 argc, args_required);
2084 return -EINVAL;
2085 }
2086
2087 return 0;
2088}
2089
2090static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning)
2091{
2092 if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) &&
2093 *dev_id <= MAX_DEV_ID)
2094 return 0;
2095
2096 if (warning)
2097 DMWARN("Message received with invalid device id: %s", arg);
2098
2099 return -EINVAL;
2100}
2101
2102static int process_create_thin_mesg(unsigned argc, char **argv, struct pool *pool)
2103{
2104 dm_thin_id dev_id;
2105 int r;
2106
2107 r = check_arg_count(argc, 2);
2108 if (r)
2109 return r;
2110
2111 r = read_dev_id(argv[1], &dev_id, 1);
2112 if (r)
2113 return r;
2114
2115 r = dm_pool_create_thin(pool->pmd, dev_id);
2116 if (r) {
2117 DMWARN("Creation of new thinly-provisioned device with id %s failed.",
2118 argv[1]);
2119 return r;
2120 }
2121
2122 return 0;
2123}
2124
2125static int process_create_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2126{
2127 dm_thin_id dev_id;
2128 dm_thin_id origin_dev_id;
2129 int r;
2130
2131 r = check_arg_count(argc, 3);
2132 if (r)
2133 return r;
2134
2135 r = read_dev_id(argv[1], &dev_id, 1);
2136 if (r)
2137 return r;
2138
2139 r = read_dev_id(argv[2], &origin_dev_id, 1);
2140 if (r)
2141 return r;
2142
2143 r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id);
2144 if (r) {
2145 DMWARN("Creation of new snapshot %s of device %s failed.",
2146 argv[1], argv[2]);
2147 return r;
2148 }
2149
2150 return 0;
2151}
2152
2153static int process_delete_mesg(unsigned argc, char **argv, struct pool *pool)
2154{
2155 dm_thin_id dev_id;
2156 int r;
2157
2158 r = check_arg_count(argc, 2);
2159 if (r)
2160 return r;
2161
2162 r = read_dev_id(argv[1], &dev_id, 1);
2163 if (r)
2164 return r;
2165
2166 r = dm_pool_delete_thin_device(pool->pmd, dev_id);
2167 if (r)
2168 DMWARN("Deletion of thin device %s failed.", argv[1]);
2169
2170 return r;
2171}
2172
2173static int process_set_transaction_id_mesg(unsigned argc, char **argv, struct pool *pool)
2174{
2175 dm_thin_id old_id, new_id;
2176 int r;
2177
2178 r = check_arg_count(argc, 3);
2179 if (r)
2180 return r;
2181
2182 if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) {
2183 DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]);
2184 return -EINVAL;
2185 }
2186
2187 if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) {
2188 DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]);
2189 return -EINVAL;
2190 }
2191
2192 r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id);
2193 if (r) {
2194 DMWARN("Failed to change transaction id from %s to %s.",
2195 argv[1], argv[2]);
2196 return r;
2197 }
2198
2199 return 0;
2200}
2201
Joe Thornbercc8394d2012-06-03 00:30:01 +01002202static int process_reserve_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2203{
2204 int r;
2205
2206 r = check_arg_count(argc, 1);
2207 if (r)
2208 return r;
2209
Joe Thornbere49e5822012-07-27 15:08:16 +01002210 (void) commit_or_fallback(pool);
Joe Thornber0d200ae2012-07-03 12:55:31 +01002211
Joe Thornbercc8394d2012-06-03 00:30:01 +01002212 r = dm_pool_reserve_metadata_snap(pool->pmd);
2213 if (r)
2214 DMWARN("reserve_metadata_snap message failed.");
2215
2216 return r;
2217}
2218
2219static int process_release_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool)
2220{
2221 int r;
2222
2223 r = check_arg_count(argc, 1);
2224 if (r)
2225 return r;
2226
2227 r = dm_pool_release_metadata_snap(pool->pmd);
2228 if (r)
2229 DMWARN("release_metadata_snap message failed.");
2230
2231 return r;
2232}
2233
Joe Thornber991d9fa2011-10-31 20:21:18 +00002234/*
2235 * Messages supported:
2236 * create_thin <dev_id>
2237 * create_snap <dev_id> <origin_id>
2238 * delete <dev_id>
2239 * trim <dev_id> <new_size_in_sectors>
2240 * set_transaction_id <current_trans_id> <new_trans_id>
Joe Thornbercc8394d2012-06-03 00:30:01 +01002241 * reserve_metadata_snap
2242 * release_metadata_snap
Joe Thornber991d9fa2011-10-31 20:21:18 +00002243 */
2244static int pool_message(struct dm_target *ti, unsigned argc, char **argv)
2245{
2246 int r = -EINVAL;
2247 struct pool_c *pt = ti->private;
2248 struct pool *pool = pt->pool;
2249
2250 if (!strcasecmp(argv[0], "create_thin"))
2251 r = process_create_thin_mesg(argc, argv, pool);
2252
2253 else if (!strcasecmp(argv[0], "create_snap"))
2254 r = process_create_snap_mesg(argc, argv, pool);
2255
2256 else if (!strcasecmp(argv[0], "delete"))
2257 r = process_delete_mesg(argc, argv, pool);
2258
2259 else if (!strcasecmp(argv[0], "set_transaction_id"))
2260 r = process_set_transaction_id_mesg(argc, argv, pool);
2261
Joe Thornbercc8394d2012-06-03 00:30:01 +01002262 else if (!strcasecmp(argv[0], "reserve_metadata_snap"))
2263 r = process_reserve_metadata_snap_mesg(argc, argv, pool);
2264
2265 else if (!strcasecmp(argv[0], "release_metadata_snap"))
2266 r = process_release_metadata_snap_mesg(argc, argv, pool);
2267
Joe Thornber991d9fa2011-10-31 20:21:18 +00002268 else
2269 DMWARN("Unrecognised thin pool target message received: %s", argv[0]);
2270
Joe Thornbere49e5822012-07-27 15:08:16 +01002271 if (!r)
2272 (void) commit_or_fallback(pool);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002273
2274 return r;
2275}
2276
Joe Thornbere49e5822012-07-27 15:08:16 +01002277static void emit_flags(struct pool_features *pf, char *result,
2278 unsigned sz, unsigned maxlen)
2279{
2280 unsigned count = !pf->zero_new_blocks + !pf->discard_enabled +
2281 !pf->discard_passdown + (pf->mode == PM_READ_ONLY);
2282 DMEMIT("%u ", count);
2283
2284 if (!pf->zero_new_blocks)
2285 DMEMIT("skip_block_zeroing ");
2286
2287 if (!pf->discard_enabled)
2288 DMEMIT("ignore_discard ");
2289
2290 if (!pf->discard_passdown)
2291 DMEMIT("no_discard_passdown ");
2292
2293 if (pf->mode == PM_READ_ONLY)
2294 DMEMIT("read_only ");
2295}
2296
Joe Thornber991d9fa2011-10-31 20:21:18 +00002297/*
2298 * Status line is:
2299 * <transaction id> <used metadata sectors>/<total metadata sectors>
2300 * <used data sectors>/<total data sectors> <held metadata root>
2301 */
2302static int pool_status(struct dm_target *ti, status_type_t type,
Alasdair G Kergon1f4e0ff2012-07-27 15:08:16 +01002303 unsigned status_flags, char *result, unsigned maxlen)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002304{
Joe Thornbere49e5822012-07-27 15:08:16 +01002305 int r;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002306 unsigned sz = 0;
2307 uint64_t transaction_id;
2308 dm_block_t nr_free_blocks_data;
2309 dm_block_t nr_free_blocks_metadata;
2310 dm_block_t nr_blocks_data;
2311 dm_block_t nr_blocks_metadata;
2312 dm_block_t held_root;
2313 char buf[BDEVNAME_SIZE];
2314 char buf2[BDEVNAME_SIZE];
2315 struct pool_c *pt = ti->private;
2316 struct pool *pool = pt->pool;
2317
2318 switch (type) {
2319 case STATUSTYPE_INFO:
Joe Thornbere49e5822012-07-27 15:08:16 +01002320 if (get_pool_mode(pool) == PM_FAIL) {
2321 DMEMIT("Fail");
2322 break;
2323 }
2324
Alasdair G Kergon1f4e0ff2012-07-27 15:08:16 +01002325 /* Commit to ensure statistics aren't out-of-date */
2326 if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
2327 (void) commit_or_fallback(pool);
2328
Joe Thornber991d9fa2011-10-31 20:21:18 +00002329 r = dm_pool_get_metadata_transaction_id(pool->pmd,
2330 &transaction_id);
2331 if (r)
2332 return r;
2333
2334 r = dm_pool_get_free_metadata_block_count(pool->pmd,
2335 &nr_free_blocks_metadata);
2336 if (r)
2337 return r;
2338
2339 r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
2340 if (r)
2341 return r;
2342
2343 r = dm_pool_get_free_block_count(pool->pmd,
2344 &nr_free_blocks_data);
2345 if (r)
2346 return r;
2347
2348 r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
2349 if (r)
2350 return r;
2351
Joe Thornbercc8394d2012-06-03 00:30:01 +01002352 r = dm_pool_get_metadata_snap(pool->pmd, &held_root);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002353 if (r)
2354 return r;
2355
2356 DMEMIT("%llu %llu/%llu %llu/%llu ",
2357 (unsigned long long)transaction_id,
2358 (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata),
2359 (unsigned long long)nr_blocks_metadata,
2360 (unsigned long long)(nr_blocks_data - nr_free_blocks_data),
2361 (unsigned long long)nr_blocks_data);
2362
2363 if (held_root)
Joe Thornbere49e5822012-07-27 15:08:16 +01002364 DMEMIT("%llu ", held_root);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002365 else
Joe Thornbere49e5822012-07-27 15:08:16 +01002366 DMEMIT("- ");
2367
2368 if (pool->pf.mode == PM_READ_ONLY)
2369 DMEMIT("ro ");
2370 else
2371 DMEMIT("rw ");
2372
Mike Snitzer018debe2012-12-21 20:23:32 +00002373 if (!pool->pf.discard_enabled)
2374 DMEMIT("ignore_discard");
2375 else if (pool->pf.discard_passdown)
Joe Thornbere49e5822012-07-27 15:08:16 +01002376 DMEMIT("discard_passdown");
2377 else
2378 DMEMIT("no_discard_passdown");
Joe Thornber991d9fa2011-10-31 20:21:18 +00002379
2380 break;
2381
2382 case STATUSTYPE_TABLE:
2383 DMEMIT("%s %s %lu %llu ",
2384 format_dev_t(buf, pt->metadata_dev->bdev->bd_dev),
2385 format_dev_t(buf2, pt->data_dev->bdev->bd_dev),
2386 (unsigned long)pool->sectors_per_block,
2387 (unsigned long long)pt->low_water_blocks);
Mike Snitzer0424caa2012-09-26 23:45:47 +01002388 emit_flags(&pt->requested_pf, result, sz, maxlen);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002389 break;
2390 }
2391
2392 return 0;
2393}
2394
2395static int pool_iterate_devices(struct dm_target *ti,
2396 iterate_devices_callout_fn fn, void *data)
2397{
2398 struct pool_c *pt = ti->private;
2399
2400 return fn(ti, pt->data_dev, 0, ti->len, data);
2401}
2402
2403static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
2404 struct bio_vec *biovec, int max_size)
2405{
2406 struct pool_c *pt = ti->private;
2407 struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
2408
2409 if (!q->merge_bvec_fn)
2410 return max_size;
2411
2412 bvm->bi_bdev = pt->data_dev->bdev;
2413
2414 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
2415}
2416
Mike Snitzer28eed342012-10-12 21:02:07 +01002417static bool block_size_is_power_of_two(struct pool *pool)
2418{
2419 return pool->sectors_per_block_shift >= 0;
2420}
2421
Mike Snitzer0424caa2012-09-26 23:45:47 +01002422static void set_discard_limits(struct pool_c *pt, struct queue_limits *limits)
Joe Thornber104655f2012-03-28 18:41:28 +01002423{
Mike Snitzer0424caa2012-09-26 23:45:47 +01002424 struct pool *pool = pt->pool;
2425 struct queue_limits *data_limits;
2426
Joe Thornber104655f2012-03-28 18:41:28 +01002427 limits->max_discard_sectors = pool->sectors_per_block;
2428
2429 /*
Mike Snitzer0424caa2012-09-26 23:45:47 +01002430 * discard_granularity is just a hint, and not enforced.
Joe Thornber104655f2012-03-28 18:41:28 +01002431 */
Mike Snitzer0424caa2012-09-26 23:45:47 +01002432 if (pt->adjusted_pf.discard_passdown) {
2433 data_limits = &bdev_get_queue(pt->data_dev->bdev)->limits;
2434 limits->discard_granularity = data_limits->discard_granularity;
Mike Snitzer28eed342012-10-12 21:02:07 +01002435 } else if (block_size_is_power_of_two(pool))
Mike Snitzer0424caa2012-09-26 23:45:47 +01002436 limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
Mike Snitzer28eed342012-10-12 21:02:07 +01002437 else
2438 /*
2439 * Use largest power of 2 that is a factor of sectors_per_block
2440 * but at least DATA_DEV_BLOCK_SIZE_MIN_SECTORS.
2441 */
2442 limits->discard_granularity = max(1 << (ffs(pool->sectors_per_block) - 1),
2443 DATA_DEV_BLOCK_SIZE_MIN_SECTORS) << SECTOR_SHIFT;
Joe Thornber104655f2012-03-28 18:41:28 +01002444}
2445
Joe Thornber991d9fa2011-10-31 20:21:18 +00002446static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
2447{
2448 struct pool_c *pt = ti->private;
2449 struct pool *pool = pt->pool;
2450
2451 blk_limits_io_min(limits, 0);
2452 blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
Mike Snitzer0424caa2012-09-26 23:45:47 +01002453
2454 /*
2455 * pt->adjusted_pf is a staging area for the actual features to use.
2456 * They get transferred to the live pool in bind_control_target()
2457 * called from pool_preresume().
2458 */
2459 if (!pt->adjusted_pf.discard_enabled)
2460 return;
2461
2462 disable_passdown_if_not_supported(pt);
2463
2464 set_discard_limits(pt, limits);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002465}
2466
2467static struct target_type pool_target = {
2468 .name = "thin-pool",
2469 .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
2470 DM_TARGET_IMMUTABLE,
Mike Snitzer018debe2012-12-21 20:23:32 +00002471 .version = {1, 6, 0},
Joe Thornber991d9fa2011-10-31 20:21:18 +00002472 .module = THIS_MODULE,
2473 .ctr = pool_ctr,
2474 .dtr = pool_dtr,
2475 .map = pool_map,
2476 .postsuspend = pool_postsuspend,
2477 .preresume = pool_preresume,
2478 .resume = pool_resume,
2479 .message = pool_message,
2480 .status = pool_status,
2481 .merge = pool_merge,
2482 .iterate_devices = pool_iterate_devices,
2483 .io_hints = pool_io_hints,
2484};
2485
2486/*----------------------------------------------------------------
2487 * Thin target methods
2488 *--------------------------------------------------------------*/
2489static void thin_dtr(struct dm_target *ti)
2490{
2491 struct thin_c *tc = ti->private;
2492
2493 mutex_lock(&dm_thin_pool_table.mutex);
2494
2495 __pool_dec(tc->pool);
2496 dm_pool_close_thin_device(tc->td);
2497 dm_put_device(ti, tc->pool_dev);
Joe Thornber2dd9c252012-03-28 18:41:28 +01002498 if (tc->origin_dev)
2499 dm_put_device(ti, tc->origin_dev);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002500 kfree(tc);
2501
2502 mutex_unlock(&dm_thin_pool_table.mutex);
2503}
2504
2505/*
2506 * Thin target parameters:
2507 *
Joe Thornber2dd9c252012-03-28 18:41:28 +01002508 * <pool_dev> <dev_id> [origin_dev]
Joe Thornber991d9fa2011-10-31 20:21:18 +00002509 *
2510 * pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
2511 * dev_id: the internal device identifier
Joe Thornber2dd9c252012-03-28 18:41:28 +01002512 * origin_dev: a device external to the pool that should act as the origin
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002513 *
2514 * If the pool device has discards disabled, they get disabled for the thin
2515 * device as well.
Joe Thornber991d9fa2011-10-31 20:21:18 +00002516 */
2517static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
2518{
2519 int r;
2520 struct thin_c *tc;
Joe Thornber2dd9c252012-03-28 18:41:28 +01002521 struct dm_dev *pool_dev, *origin_dev;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002522 struct mapped_device *pool_md;
2523
2524 mutex_lock(&dm_thin_pool_table.mutex);
2525
Joe Thornber2dd9c252012-03-28 18:41:28 +01002526 if (argc != 2 && argc != 3) {
Joe Thornber991d9fa2011-10-31 20:21:18 +00002527 ti->error = "Invalid argument count";
2528 r = -EINVAL;
2529 goto out_unlock;
2530 }
2531
2532 tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL);
2533 if (!tc) {
2534 ti->error = "Out of memory";
2535 r = -ENOMEM;
2536 goto out_unlock;
2537 }
2538
Joe Thornber2dd9c252012-03-28 18:41:28 +01002539 if (argc == 3) {
2540 r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev);
2541 if (r) {
2542 ti->error = "Error opening origin device";
2543 goto bad_origin_dev;
2544 }
2545 tc->origin_dev = origin_dev;
2546 }
2547
Joe Thornber991d9fa2011-10-31 20:21:18 +00002548 r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev);
2549 if (r) {
2550 ti->error = "Error opening pool device";
2551 goto bad_pool_dev;
2552 }
2553 tc->pool_dev = pool_dev;
2554
2555 if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) {
2556 ti->error = "Invalid device id";
2557 r = -EINVAL;
2558 goto bad_common;
2559 }
2560
2561 pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev);
2562 if (!pool_md) {
2563 ti->error = "Couldn't get pool mapped device";
2564 r = -EINVAL;
2565 goto bad_common;
2566 }
2567
2568 tc->pool = __pool_table_lookup(pool_md);
2569 if (!tc->pool) {
2570 ti->error = "Couldn't find pool object";
2571 r = -EINVAL;
2572 goto bad_pool_lookup;
2573 }
2574 __pool_inc(tc->pool);
2575
Joe Thornbere49e5822012-07-27 15:08:16 +01002576 if (get_pool_mode(tc->pool) == PM_FAIL) {
2577 ti->error = "Couldn't open thin device, Pool is in fail mode";
2578 goto bad_thin_open;
2579 }
2580
Joe Thornber991d9fa2011-10-31 20:21:18 +00002581 r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td);
2582 if (r) {
2583 ti->error = "Couldn't open thin internal device";
2584 goto bad_thin_open;
2585 }
2586
Mike Snitzer542f9032012-07-27 15:08:00 +01002587 r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
2588 if (r)
2589 goto bad_thin_open;
2590
Joe Thornber991d9fa2011-10-31 20:21:18 +00002591 ti->num_flush_requests = 1;
Joe Thornber16ad3d12012-07-27 15:08:07 +01002592 ti->flush_supported = true;
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00002593 ti->per_bio_data_size = sizeof(struct dm_thin_endio_hook);
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002594
2595 /* In case the pool supports discards, pass them on. */
2596 if (tc->pool->pf.discard_enabled) {
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01002597 ti->discards_supported = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002598 ti->num_discard_requests = 1;
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01002599 ti->discard_zeroes_data_unsupported = true;
Mikulas Patocka49296302012-07-27 15:08:03 +01002600 /* Discard requests must be split on a block boundary */
Alasdair G Kergon0ac55482012-07-27 15:08:08 +01002601 ti->split_discard_requests = true;
Joe Thornber67e2e2b2012-03-28 18:41:29 +01002602 }
Joe Thornber991d9fa2011-10-31 20:21:18 +00002603
2604 dm_put(pool_md);
2605
2606 mutex_unlock(&dm_thin_pool_table.mutex);
2607
2608 return 0;
2609
2610bad_thin_open:
2611 __pool_dec(tc->pool);
2612bad_pool_lookup:
2613 dm_put(pool_md);
2614bad_common:
2615 dm_put_device(ti, tc->pool_dev);
2616bad_pool_dev:
Joe Thornber2dd9c252012-03-28 18:41:28 +01002617 if (tc->origin_dev)
2618 dm_put_device(ti, tc->origin_dev);
2619bad_origin_dev:
Joe Thornber991d9fa2011-10-31 20:21:18 +00002620 kfree(tc);
2621out_unlock:
2622 mutex_unlock(&dm_thin_pool_table.mutex);
2623
2624 return r;
2625}
2626
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00002627static int thin_map(struct dm_target *ti, struct bio *bio)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002628{
Alasdair G Kergon6efd6e82012-03-28 18:41:28 +01002629 bio->bi_sector = dm_target_offset(ti, bio->bi_sector);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002630
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00002631 return thin_bio_map(ti, bio);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002632}
2633
Mikulas Patocka7de3ee52012-12-21 20:23:41 +00002634static int thin_endio(struct dm_target *ti, struct bio *bio, int err)
Joe Thornbereb2aa482012-03-28 18:41:28 +01002635{
2636 unsigned long flags;
Mikulas Patocka59c3d2c2012-12-21 20:23:40 +00002637 struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
Joe Thornbereb2aa482012-03-28 18:41:28 +01002638 struct list_head work;
Mike Snitzera24c2562012-06-03 00:30:00 +01002639 struct dm_thin_new_mapping *m, *tmp;
Joe Thornbereb2aa482012-03-28 18:41:28 +01002640 struct pool *pool = h->tc->pool;
2641
2642 if (h->shared_read_entry) {
2643 INIT_LIST_HEAD(&work);
Mike Snitzer44feb382012-10-12 21:02:10 +01002644 dm_deferred_entry_dec(h->shared_read_entry, &work);
Joe Thornbereb2aa482012-03-28 18:41:28 +01002645
2646 spin_lock_irqsave(&pool->lock, flags);
2647 list_for_each_entry_safe(m, tmp, &work, list) {
2648 list_del(&m->list);
2649 m->quiesced = 1;
2650 __maybe_add_mapping(m);
2651 }
2652 spin_unlock_irqrestore(&pool->lock, flags);
2653 }
2654
Joe Thornber104655f2012-03-28 18:41:28 +01002655 if (h->all_io_entry) {
2656 INIT_LIST_HEAD(&work);
Mike Snitzer44feb382012-10-12 21:02:10 +01002657 dm_deferred_entry_dec(h->all_io_entry, &work);
Joe Thornber563af182012-12-21 20:23:31 +00002658 if (!list_empty(&work)) {
2659 spin_lock_irqsave(&pool->lock, flags);
2660 list_for_each_entry_safe(m, tmp, &work, list)
2661 list_add(&m->list, &pool->prepared_discards);
2662 spin_unlock_irqrestore(&pool->lock, flags);
2663 wake_worker(pool);
2664 }
Joe Thornber104655f2012-03-28 18:41:28 +01002665 }
2666
Joe Thornbereb2aa482012-03-28 18:41:28 +01002667 return 0;
2668}
2669
Joe Thornber991d9fa2011-10-31 20:21:18 +00002670static void thin_postsuspend(struct dm_target *ti)
2671{
2672 if (dm_noflush_suspending(ti))
2673 requeue_io((struct thin_c *)ti->private);
2674}
2675
2676/*
2677 * <nr mapped sectors> <highest mapped sector>
2678 */
2679static int thin_status(struct dm_target *ti, status_type_t type,
Alasdair G Kergon1f4e0ff2012-07-27 15:08:16 +01002680 unsigned status_flags, char *result, unsigned maxlen)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002681{
2682 int r;
2683 ssize_t sz = 0;
2684 dm_block_t mapped, highest;
2685 char buf[BDEVNAME_SIZE];
2686 struct thin_c *tc = ti->private;
2687
Joe Thornbere49e5822012-07-27 15:08:16 +01002688 if (get_pool_mode(tc->pool) == PM_FAIL) {
2689 DMEMIT("Fail");
2690 return 0;
2691 }
2692
Joe Thornber991d9fa2011-10-31 20:21:18 +00002693 if (!tc->td)
2694 DMEMIT("-");
2695 else {
2696 switch (type) {
2697 case STATUSTYPE_INFO:
2698 r = dm_thin_get_mapped_count(tc->td, &mapped);
2699 if (r)
2700 return r;
2701
2702 r = dm_thin_get_highest_mapped_block(tc->td, &highest);
2703 if (r < 0)
2704 return r;
2705
2706 DMEMIT("%llu ", mapped * tc->pool->sectors_per_block);
2707 if (r)
2708 DMEMIT("%llu", ((highest + 1) *
2709 tc->pool->sectors_per_block) - 1);
2710 else
2711 DMEMIT("-");
2712 break;
2713
2714 case STATUSTYPE_TABLE:
2715 DMEMIT("%s %lu",
2716 format_dev_t(buf, tc->pool_dev->bdev->bd_dev),
2717 (unsigned long) tc->dev_id);
Joe Thornber2dd9c252012-03-28 18:41:28 +01002718 if (tc->origin_dev)
2719 DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev));
Joe Thornber991d9fa2011-10-31 20:21:18 +00002720 break;
2721 }
2722 }
2723
2724 return 0;
2725}
2726
2727static int thin_iterate_devices(struct dm_target *ti,
2728 iterate_devices_callout_fn fn, void *data)
2729{
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002730 sector_t blocks;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002731 struct thin_c *tc = ti->private;
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002732 struct pool *pool = tc->pool;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002733
2734 /*
2735 * We can't call dm_pool_get_data_dev_size() since that blocks. So
2736 * we follow a more convoluted path through to the pool's target.
2737 */
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002738 if (!pool->ti)
Joe Thornber991d9fa2011-10-31 20:21:18 +00002739 return 0; /* nothing is bound */
2740
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002741 blocks = pool->ti->len;
2742 (void) sector_div(blocks, pool->sectors_per_block);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002743 if (blocks)
Mike Snitzer55f2b8b2012-07-27 15:08:02 +01002744 return fn(ti, tc->pool_dev, 0, pool->sectors_per_block * blocks, data);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002745
2746 return 0;
2747}
2748
Mike Snitzer0424caa2012-09-26 23:45:47 +01002749/*
2750 * A thin device always inherits its queue limits from its pool.
2751 */
Joe Thornber991d9fa2011-10-31 20:21:18 +00002752static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
2753{
2754 struct thin_c *tc = ti->private;
2755
Mike Snitzer0424caa2012-09-26 23:45:47 +01002756 *limits = bdev_get_queue(tc->pool_dev->bdev)->limits;
Joe Thornber991d9fa2011-10-31 20:21:18 +00002757}
2758
2759static struct target_type thin_target = {
2760 .name = "thin",
Mike Snitzer70d6c402012-12-21 20:23:37 +00002761 .version = {1, 6, 0},
Joe Thornber991d9fa2011-10-31 20:21:18 +00002762 .module = THIS_MODULE,
2763 .ctr = thin_ctr,
2764 .dtr = thin_dtr,
2765 .map = thin_map,
Joe Thornbereb2aa482012-03-28 18:41:28 +01002766 .end_io = thin_endio,
Joe Thornber991d9fa2011-10-31 20:21:18 +00002767 .postsuspend = thin_postsuspend,
2768 .status = thin_status,
2769 .iterate_devices = thin_iterate_devices,
2770 .io_hints = thin_io_hints,
2771};
2772
2773/*----------------------------------------------------------------*/
2774
2775static int __init dm_thin_init(void)
2776{
2777 int r;
2778
2779 pool_table_init();
2780
2781 r = dm_register_target(&thin_target);
2782 if (r)
2783 return r;
2784
2785 r = dm_register_target(&pool_target);
2786 if (r)
Mike Snitzera24c2562012-06-03 00:30:00 +01002787 goto bad_pool_target;
2788
2789 r = -ENOMEM;
2790
Mike Snitzera24c2562012-06-03 00:30:00 +01002791 _new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
2792 if (!_new_mapping_cache)
2793 goto bad_new_mapping_cache;
2794
Mike Snitzera24c2562012-06-03 00:30:00 +01002795 return 0;
2796
Mike Snitzera24c2562012-06-03 00:30:00 +01002797bad_new_mapping_cache:
Mike Snitzera24c2562012-06-03 00:30:00 +01002798 dm_unregister_target(&pool_target);
2799bad_pool_target:
2800 dm_unregister_target(&thin_target);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002801
2802 return r;
2803}
2804
2805static void dm_thin_exit(void)
2806{
2807 dm_unregister_target(&thin_target);
2808 dm_unregister_target(&pool_target);
Mike Snitzera24c2562012-06-03 00:30:00 +01002809
Mike Snitzera24c2562012-06-03 00:30:00 +01002810 kmem_cache_destroy(_new_mapping_cache);
Joe Thornber991d9fa2011-10-31 20:21:18 +00002811}
2812
2813module_init(dm_thin_init);
2814module_exit(dm_thin_exit);
2815
Alasdair G Kergon7cab8bf2012-05-12 01:43:19 +01002816MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
Joe Thornber991d9fa2011-10-31 20:21:18 +00002817MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
2818MODULE_LICENSE("GPL");