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991d9fa0 JT |
1 | /* |
2 | * Copyright (C) 2011 Red Hat UK. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7 | #include "dm-thin-metadata.h" | |
8 | ||
9 | #include <linux/device-mapper.h> | |
10 | #include <linux/dm-io.h> | |
11 | #include <linux/dm-kcopyd.h> | |
12 | #include <linux/list.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/slab.h> | |
16 | ||
17 | #define DM_MSG_PREFIX "thin" | |
18 | ||
19 | /* | |
20 | * Tunable constants | |
21 | */ | |
22 | #define ENDIO_HOOK_POOL_SIZE 10240 | |
23 | #define DEFERRED_SET_SIZE 64 | |
24 | #define MAPPING_POOL_SIZE 1024 | |
25 | #define PRISON_CELLS 1024 | |
905e51b3 | 26 | #define COMMIT_PERIOD HZ |
991d9fa0 JT |
27 | |
28 | /* | |
29 | * The block size of the device holding pool data must be | |
30 | * between 64KB and 1GB. | |
31 | */ | |
32 | #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT) | |
33 | #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT) | |
34 | ||
991d9fa0 JT |
35 | /* |
36 | * Device id is restricted to 24 bits. | |
37 | */ | |
38 | #define MAX_DEV_ID ((1 << 24) - 1) | |
39 | ||
40 | /* | |
41 | * How do we handle breaking sharing of data blocks? | |
42 | * ================================================= | |
43 | * | |
44 | * We use a standard copy-on-write btree to store the mappings for the | |
45 | * devices (note I'm talking about copy-on-write of the metadata here, not | |
46 | * the data). When you take an internal snapshot you clone the root node | |
47 | * of the origin btree. After this there is no concept of an origin or a | |
48 | * snapshot. They are just two device trees that happen to point to the | |
49 | * same data blocks. | |
50 | * | |
51 | * When we get a write in we decide if it's to a shared data block using | |
52 | * some timestamp magic. If it is, we have to break sharing. | |
53 | * | |
54 | * Let's say we write to a shared block in what was the origin. The | |
55 | * steps are: | |
56 | * | |
57 | * i) plug io further to this physical block. (see bio_prison code). | |
58 | * | |
59 | * ii) quiesce any read io to that shared data block. Obviously | |
60 | * including all devices that share this block. (see deferred_set code) | |
61 | * | |
62 | * iii) copy the data block to a newly allocate block. This step can be | |
63 | * missed out if the io covers the block. (schedule_copy). | |
64 | * | |
65 | * iv) insert the new mapping into the origin's btree | |
fe878f34 | 66 | * (process_prepared_mapping). This act of inserting breaks some |
991d9fa0 JT |
67 | * sharing of btree nodes between the two devices. Breaking sharing only |
68 | * effects the btree of that specific device. Btrees for the other | |
69 | * devices that share the block never change. The btree for the origin | |
70 | * device as it was after the last commit is untouched, ie. we're using | |
71 | * persistent data structures in the functional programming sense. | |
72 | * | |
73 | * v) unplug io to this physical block, including the io that triggered | |
74 | * the breaking of sharing. | |
75 | * | |
76 | * Steps (ii) and (iii) occur in parallel. | |
77 | * | |
78 | * The metadata _doesn't_ need to be committed before the io continues. We | |
79 | * get away with this because the io is always written to a _new_ block. | |
80 | * If there's a crash, then: | |
81 | * | |
82 | * - The origin mapping will point to the old origin block (the shared | |
83 | * one). This will contain the data as it was before the io that triggered | |
84 | * the breaking of sharing came in. | |
85 | * | |
86 | * - The snap mapping still points to the old block. As it would after | |
87 | * the commit. | |
88 | * | |
89 | * The downside of this scheme is the timestamp magic isn't perfect, and | |
90 | * will continue to think that data block in the snapshot device is shared | |
91 | * even after the write to the origin has broken sharing. I suspect data | |
92 | * blocks will typically be shared by many different devices, so we're | |
93 | * breaking sharing n + 1 times, rather than n, where n is the number of | |
94 | * devices that reference this data block. At the moment I think the | |
95 | * benefits far, far outweigh the disadvantages. | |
96 | */ | |
97 | ||
98 | /*----------------------------------------------------------------*/ | |
99 | ||
100 | /* | |
101 | * Sometimes we can't deal with a bio straight away. We put them in prison | |
102 | * where they can't cause any mischief. Bios are put in a cell identified | |
103 | * by a key, multiple bios can be in the same cell. When the cell is | |
104 | * subsequently unlocked the bios become available. | |
105 | */ | |
106 | struct bio_prison; | |
107 | ||
108 | struct cell_key { | |
109 | int virtual; | |
110 | dm_thin_id dev; | |
111 | dm_block_t block; | |
112 | }; | |
113 | ||
114 | struct cell { | |
115 | struct hlist_node list; | |
116 | struct bio_prison *prison; | |
117 | struct cell_key key; | |
6f94a4c4 | 118 | struct bio *holder; |
991d9fa0 JT |
119 | struct bio_list bios; |
120 | }; | |
121 | ||
122 | struct bio_prison { | |
123 | spinlock_t lock; | |
124 | mempool_t *cell_pool; | |
125 | ||
126 | unsigned nr_buckets; | |
127 | unsigned hash_mask; | |
128 | struct hlist_head *cells; | |
129 | }; | |
130 | ||
131 | static uint32_t calc_nr_buckets(unsigned nr_cells) | |
132 | { | |
133 | uint32_t n = 128; | |
134 | ||
135 | nr_cells /= 4; | |
136 | nr_cells = min(nr_cells, 8192u); | |
137 | ||
138 | while (n < nr_cells) | |
139 | n <<= 1; | |
140 | ||
141 | return n; | |
142 | } | |
143 | ||
144 | /* | |
145 | * @nr_cells should be the number of cells you want in use _concurrently_. | |
146 | * Don't confuse it with the number of distinct keys. | |
147 | */ | |
148 | static struct bio_prison *prison_create(unsigned nr_cells) | |
149 | { | |
150 | unsigned i; | |
151 | uint32_t nr_buckets = calc_nr_buckets(nr_cells); | |
152 | size_t len = sizeof(struct bio_prison) + | |
153 | (sizeof(struct hlist_head) * nr_buckets); | |
154 | struct bio_prison *prison = kmalloc(len, GFP_KERNEL); | |
155 | ||
156 | if (!prison) | |
157 | return NULL; | |
158 | ||
159 | spin_lock_init(&prison->lock); | |
160 | prison->cell_pool = mempool_create_kmalloc_pool(nr_cells, | |
161 | sizeof(struct cell)); | |
162 | if (!prison->cell_pool) { | |
163 | kfree(prison); | |
164 | return NULL; | |
165 | } | |
166 | ||
167 | prison->nr_buckets = nr_buckets; | |
168 | prison->hash_mask = nr_buckets - 1; | |
169 | prison->cells = (struct hlist_head *) (prison + 1); | |
170 | for (i = 0; i < nr_buckets; i++) | |
171 | INIT_HLIST_HEAD(prison->cells + i); | |
172 | ||
173 | return prison; | |
174 | } | |
175 | ||
176 | static void prison_destroy(struct bio_prison *prison) | |
177 | { | |
178 | mempool_destroy(prison->cell_pool); | |
179 | kfree(prison); | |
180 | } | |
181 | ||
182 | static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key) | |
183 | { | |
184 | const unsigned long BIG_PRIME = 4294967291UL; | |
185 | uint64_t hash = key->block * BIG_PRIME; | |
186 | ||
187 | return (uint32_t) (hash & prison->hash_mask); | |
188 | } | |
189 | ||
190 | static int keys_equal(struct cell_key *lhs, struct cell_key *rhs) | |
191 | { | |
192 | return (lhs->virtual == rhs->virtual) && | |
193 | (lhs->dev == rhs->dev) && | |
194 | (lhs->block == rhs->block); | |
195 | } | |
196 | ||
197 | static struct cell *__search_bucket(struct hlist_head *bucket, | |
198 | struct cell_key *key) | |
199 | { | |
200 | struct cell *cell; | |
201 | struct hlist_node *tmp; | |
202 | ||
203 | hlist_for_each_entry(cell, tmp, bucket, list) | |
204 | if (keys_equal(&cell->key, key)) | |
205 | return cell; | |
206 | ||
207 | return NULL; | |
208 | } | |
209 | ||
210 | /* | |
211 | * This may block if a new cell needs allocating. You must ensure that | |
212 | * cells will be unlocked even if the calling thread is blocked. | |
213 | * | |
6f94a4c4 | 214 | * Returns 1 if the cell was already held, 0 if @inmate is the new holder. |
991d9fa0 JT |
215 | */ |
216 | static int bio_detain(struct bio_prison *prison, struct cell_key *key, | |
217 | struct bio *inmate, struct cell **ref) | |
218 | { | |
6f94a4c4 | 219 | int r = 1; |
991d9fa0 JT |
220 | unsigned long flags; |
221 | uint32_t hash = hash_key(prison, key); | |
6f94a4c4 | 222 | struct cell *cell, *cell2; |
991d9fa0 JT |
223 | |
224 | BUG_ON(hash > prison->nr_buckets); | |
225 | ||
226 | spin_lock_irqsave(&prison->lock, flags); | |
991d9fa0 | 227 | |
6f94a4c4 JT |
228 | cell = __search_bucket(prison->cells + hash, key); |
229 | if (cell) { | |
230 | bio_list_add(&cell->bios, inmate); | |
231 | goto out; | |
991d9fa0 JT |
232 | } |
233 | ||
6f94a4c4 JT |
234 | /* |
235 | * Allocate a new cell | |
236 | */ | |
991d9fa0 | 237 | spin_unlock_irqrestore(&prison->lock, flags); |
6f94a4c4 JT |
238 | cell2 = mempool_alloc(prison->cell_pool, GFP_NOIO); |
239 | spin_lock_irqsave(&prison->lock, flags); | |
991d9fa0 | 240 | |
6f94a4c4 JT |
241 | /* |
242 | * We've been unlocked, so we have to double check that | |
243 | * nobody else has inserted this cell in the meantime. | |
244 | */ | |
245 | cell = __search_bucket(prison->cells + hash, key); | |
246 | if (cell) { | |
991d9fa0 | 247 | mempool_free(cell2, prison->cell_pool); |
6f94a4c4 JT |
248 | bio_list_add(&cell->bios, inmate); |
249 | goto out; | |
250 | } | |
251 | ||
252 | /* | |
253 | * Use new cell. | |
254 | */ | |
255 | cell = cell2; | |
256 | ||
257 | cell->prison = prison; | |
258 | memcpy(&cell->key, key, sizeof(cell->key)); | |
259 | cell->holder = inmate; | |
260 | bio_list_init(&cell->bios); | |
261 | hlist_add_head(&cell->list, prison->cells + hash); | |
262 | ||
263 | r = 0; | |
264 | ||
265 | out: | |
266 | spin_unlock_irqrestore(&prison->lock, flags); | |
991d9fa0 JT |
267 | |
268 | *ref = cell; | |
269 | ||
270 | return r; | |
271 | } | |
272 | ||
273 | /* | |
274 | * @inmates must have been initialised prior to this call | |
275 | */ | |
276 | static void __cell_release(struct cell *cell, struct bio_list *inmates) | |
277 | { | |
278 | struct bio_prison *prison = cell->prison; | |
279 | ||
280 | hlist_del(&cell->list); | |
281 | ||
6f94a4c4 JT |
282 | bio_list_add(inmates, cell->holder); |
283 | bio_list_merge(inmates, &cell->bios); | |
991d9fa0 JT |
284 | |
285 | mempool_free(cell, prison->cell_pool); | |
286 | } | |
287 | ||
288 | static void cell_release(struct cell *cell, struct bio_list *bios) | |
289 | { | |
290 | unsigned long flags; | |
291 | struct bio_prison *prison = cell->prison; | |
292 | ||
293 | spin_lock_irqsave(&prison->lock, flags); | |
294 | __cell_release(cell, bios); | |
295 | spin_unlock_irqrestore(&prison->lock, flags); | |
296 | } | |
297 | ||
298 | /* | |
299 | * There are a couple of places where we put a bio into a cell briefly | |
300 | * before taking it out again. In these situations we know that no other | |
301 | * bio may be in the cell. This function releases the cell, and also does | |
302 | * a sanity check. | |
303 | */ | |
6f94a4c4 JT |
304 | static void __cell_release_singleton(struct cell *cell, struct bio *bio) |
305 | { | |
306 | hlist_del(&cell->list); | |
307 | BUG_ON(cell->holder != bio); | |
308 | BUG_ON(!bio_list_empty(&cell->bios)); | |
309 | } | |
310 | ||
991d9fa0 JT |
311 | static void cell_release_singleton(struct cell *cell, struct bio *bio) |
312 | { | |
991d9fa0 | 313 | unsigned long flags; |
6f94a4c4 | 314 | struct bio_prison *prison = cell->prison; |
991d9fa0 JT |
315 | |
316 | spin_lock_irqsave(&prison->lock, flags); | |
6f94a4c4 | 317 | __cell_release_singleton(cell, bio); |
991d9fa0 | 318 | spin_unlock_irqrestore(&prison->lock, flags); |
6f94a4c4 JT |
319 | } |
320 | ||
321 | /* | |
322 | * Sometimes we don't want the holder, just the additional bios. | |
323 | */ | |
324 | static void __cell_release_no_holder(struct cell *cell, struct bio_list *inmates) | |
325 | { | |
326 | struct bio_prison *prison = cell->prison; | |
327 | ||
328 | hlist_del(&cell->list); | |
329 | bio_list_merge(inmates, &cell->bios); | |
330 | ||
331 | mempool_free(cell, prison->cell_pool); | |
332 | } | |
333 | ||
334 | static void cell_release_no_holder(struct cell *cell, struct bio_list *inmates) | |
335 | { | |
336 | unsigned long flags; | |
337 | struct bio_prison *prison = cell->prison; | |
991d9fa0 | 338 | |
6f94a4c4 JT |
339 | spin_lock_irqsave(&prison->lock, flags); |
340 | __cell_release_no_holder(cell, inmates); | |
341 | spin_unlock_irqrestore(&prison->lock, flags); | |
991d9fa0 JT |
342 | } |
343 | ||
344 | static void cell_error(struct cell *cell) | |
345 | { | |
346 | struct bio_prison *prison = cell->prison; | |
347 | struct bio_list bios; | |
348 | struct bio *bio; | |
349 | unsigned long flags; | |
350 | ||
351 | bio_list_init(&bios); | |
352 | ||
353 | spin_lock_irqsave(&prison->lock, flags); | |
354 | __cell_release(cell, &bios); | |
355 | spin_unlock_irqrestore(&prison->lock, flags); | |
356 | ||
357 | while ((bio = bio_list_pop(&bios))) | |
358 | bio_io_error(bio); | |
359 | } | |
360 | ||
361 | /*----------------------------------------------------------------*/ | |
362 | ||
363 | /* | |
364 | * We use the deferred set to keep track of pending reads to shared blocks. | |
365 | * We do this to ensure the new mapping caused by a write isn't performed | |
366 | * until these prior reads have completed. Otherwise the insertion of the | |
367 | * new mapping could free the old block that the read bios are mapped to. | |
368 | */ | |
369 | ||
370 | struct deferred_set; | |
371 | struct deferred_entry { | |
372 | struct deferred_set *ds; | |
373 | unsigned count; | |
374 | struct list_head work_items; | |
375 | }; | |
376 | ||
377 | struct deferred_set { | |
378 | spinlock_t lock; | |
379 | unsigned current_entry; | |
380 | unsigned sweeper; | |
381 | struct deferred_entry entries[DEFERRED_SET_SIZE]; | |
382 | }; | |
383 | ||
384 | static void ds_init(struct deferred_set *ds) | |
385 | { | |
386 | int i; | |
387 | ||
388 | spin_lock_init(&ds->lock); | |
389 | ds->current_entry = 0; | |
390 | ds->sweeper = 0; | |
391 | for (i = 0; i < DEFERRED_SET_SIZE; i++) { | |
392 | ds->entries[i].ds = ds; | |
393 | ds->entries[i].count = 0; | |
394 | INIT_LIST_HEAD(&ds->entries[i].work_items); | |
395 | } | |
396 | } | |
397 | ||
398 | static struct deferred_entry *ds_inc(struct deferred_set *ds) | |
399 | { | |
400 | unsigned long flags; | |
401 | struct deferred_entry *entry; | |
402 | ||
403 | spin_lock_irqsave(&ds->lock, flags); | |
404 | entry = ds->entries + ds->current_entry; | |
405 | entry->count++; | |
406 | spin_unlock_irqrestore(&ds->lock, flags); | |
407 | ||
408 | return entry; | |
409 | } | |
410 | ||
411 | static unsigned ds_next(unsigned index) | |
412 | { | |
413 | return (index + 1) % DEFERRED_SET_SIZE; | |
414 | } | |
415 | ||
416 | static void __sweep(struct deferred_set *ds, struct list_head *head) | |
417 | { | |
418 | while ((ds->sweeper != ds->current_entry) && | |
419 | !ds->entries[ds->sweeper].count) { | |
420 | list_splice_init(&ds->entries[ds->sweeper].work_items, head); | |
421 | ds->sweeper = ds_next(ds->sweeper); | |
422 | } | |
423 | ||
424 | if ((ds->sweeper == ds->current_entry) && !ds->entries[ds->sweeper].count) | |
425 | list_splice_init(&ds->entries[ds->sweeper].work_items, head); | |
426 | } | |
427 | ||
428 | static void ds_dec(struct deferred_entry *entry, struct list_head *head) | |
429 | { | |
430 | unsigned long flags; | |
431 | ||
432 | spin_lock_irqsave(&entry->ds->lock, flags); | |
433 | BUG_ON(!entry->count); | |
434 | --entry->count; | |
435 | __sweep(entry->ds, head); | |
436 | spin_unlock_irqrestore(&entry->ds->lock, flags); | |
437 | } | |
438 | ||
439 | /* | |
440 | * Returns 1 if deferred or 0 if no pending items to delay job. | |
441 | */ | |
442 | static int ds_add_work(struct deferred_set *ds, struct list_head *work) | |
443 | { | |
444 | int r = 1; | |
445 | unsigned long flags; | |
446 | unsigned next_entry; | |
447 | ||
448 | spin_lock_irqsave(&ds->lock, flags); | |
449 | if ((ds->sweeper == ds->current_entry) && | |
450 | !ds->entries[ds->current_entry].count) | |
451 | r = 0; | |
452 | else { | |
453 | list_add(work, &ds->entries[ds->current_entry].work_items); | |
454 | next_entry = ds_next(ds->current_entry); | |
455 | if (!ds->entries[next_entry].count) | |
456 | ds->current_entry = next_entry; | |
457 | } | |
458 | spin_unlock_irqrestore(&ds->lock, flags); | |
459 | ||
460 | return r; | |
461 | } | |
462 | ||
463 | /*----------------------------------------------------------------*/ | |
464 | ||
465 | /* | |
466 | * Key building. | |
467 | */ | |
468 | static void build_data_key(struct dm_thin_device *td, | |
469 | dm_block_t b, struct cell_key *key) | |
470 | { | |
471 | key->virtual = 0; | |
472 | key->dev = dm_thin_dev_id(td); | |
473 | key->block = b; | |
474 | } | |
475 | ||
476 | static void build_virtual_key(struct dm_thin_device *td, dm_block_t b, | |
477 | struct cell_key *key) | |
478 | { | |
479 | key->virtual = 1; | |
480 | key->dev = dm_thin_dev_id(td); | |
481 | key->block = b; | |
482 | } | |
483 | ||
484 | /*----------------------------------------------------------------*/ | |
485 | ||
486 | /* | |
487 | * A pool device ties together a metadata device and a data device. It | |
488 | * also provides the interface for creating and destroying internal | |
489 | * devices. | |
490 | */ | |
491 | struct new_mapping; | |
492 | struct pool { | |
493 | struct list_head list; | |
494 | struct dm_target *ti; /* Only set if a pool target is bound */ | |
495 | ||
496 | struct mapped_device *pool_md; | |
497 | struct block_device *md_dev; | |
498 | struct dm_pool_metadata *pmd; | |
499 | ||
500 | uint32_t sectors_per_block; | |
501 | unsigned block_shift; | |
502 | dm_block_t offset_mask; | |
503 | dm_block_t low_water_blocks; | |
504 | ||
505 | unsigned zero_new_blocks:1; | |
506 | unsigned low_water_triggered:1; /* A dm event has been sent */ | |
507 | unsigned no_free_space:1; /* A -ENOSPC warning has been issued */ | |
508 | ||
509 | struct bio_prison *prison; | |
510 | struct dm_kcopyd_client *copier; | |
511 | ||
512 | struct workqueue_struct *wq; | |
513 | struct work_struct worker; | |
905e51b3 | 514 | struct delayed_work waker; |
991d9fa0 JT |
515 | |
516 | unsigned ref_count; | |
905e51b3 | 517 | unsigned long last_commit_jiffies; |
991d9fa0 JT |
518 | |
519 | spinlock_t lock; | |
520 | struct bio_list deferred_bios; | |
521 | struct bio_list deferred_flush_bios; | |
522 | struct list_head prepared_mappings; | |
104655fd | 523 | struct list_head prepared_discards; |
991d9fa0 JT |
524 | |
525 | struct bio_list retry_on_resume_list; | |
526 | ||
eb2aa48d | 527 | struct deferred_set shared_read_ds; |
104655fd | 528 | struct deferred_set all_io_ds; |
991d9fa0 JT |
529 | |
530 | struct new_mapping *next_mapping; | |
531 | mempool_t *mapping_pool; | |
532 | mempool_t *endio_hook_pool; | |
533 | }; | |
534 | ||
535 | /* | |
536 | * Target context for a pool. | |
537 | */ | |
538 | struct pool_c { | |
539 | struct dm_target *ti; | |
540 | struct pool *pool; | |
541 | struct dm_dev *data_dev; | |
542 | struct dm_dev *metadata_dev; | |
543 | struct dm_target_callbacks callbacks; | |
544 | ||
545 | dm_block_t low_water_blocks; | |
546 | unsigned zero_new_blocks:1; | |
547 | }; | |
548 | ||
549 | /* | |
550 | * Target context for a thin. | |
551 | */ | |
552 | struct thin_c { | |
553 | struct dm_dev *pool_dev; | |
2dd9c257 | 554 | struct dm_dev *origin_dev; |
991d9fa0 JT |
555 | dm_thin_id dev_id; |
556 | ||
557 | struct pool *pool; | |
558 | struct dm_thin_device *td; | |
559 | }; | |
560 | ||
561 | /*----------------------------------------------------------------*/ | |
562 | ||
563 | /* | |
564 | * A global list of pools that uses a struct mapped_device as a key. | |
565 | */ | |
566 | static struct dm_thin_pool_table { | |
567 | struct mutex mutex; | |
568 | struct list_head pools; | |
569 | } dm_thin_pool_table; | |
570 | ||
571 | static void pool_table_init(void) | |
572 | { | |
573 | mutex_init(&dm_thin_pool_table.mutex); | |
574 | INIT_LIST_HEAD(&dm_thin_pool_table.pools); | |
575 | } | |
576 | ||
577 | static void __pool_table_insert(struct pool *pool) | |
578 | { | |
579 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
580 | list_add(&pool->list, &dm_thin_pool_table.pools); | |
581 | } | |
582 | ||
583 | static void __pool_table_remove(struct pool *pool) | |
584 | { | |
585 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
586 | list_del(&pool->list); | |
587 | } | |
588 | ||
589 | static struct pool *__pool_table_lookup(struct mapped_device *md) | |
590 | { | |
591 | struct pool *pool = NULL, *tmp; | |
592 | ||
593 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
594 | ||
595 | list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) { | |
596 | if (tmp->pool_md == md) { | |
597 | pool = tmp; | |
598 | break; | |
599 | } | |
600 | } | |
601 | ||
602 | return pool; | |
603 | } | |
604 | ||
605 | static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev) | |
606 | { | |
607 | struct pool *pool = NULL, *tmp; | |
608 | ||
609 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
610 | ||
611 | list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) { | |
612 | if (tmp->md_dev == md_dev) { | |
613 | pool = tmp; | |
614 | break; | |
615 | } | |
616 | } | |
617 | ||
618 | return pool; | |
619 | } | |
620 | ||
621 | /*----------------------------------------------------------------*/ | |
622 | ||
eb2aa48d JT |
623 | struct endio_hook { |
624 | struct thin_c *tc; | |
625 | struct deferred_entry *shared_read_entry; | |
104655fd | 626 | struct deferred_entry *all_io_entry; |
eb2aa48d JT |
627 | struct new_mapping *overwrite_mapping; |
628 | }; | |
629 | ||
991d9fa0 JT |
630 | static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master) |
631 | { | |
632 | struct bio *bio; | |
633 | struct bio_list bios; | |
634 | ||
635 | bio_list_init(&bios); | |
636 | bio_list_merge(&bios, master); | |
637 | bio_list_init(master); | |
638 | ||
639 | while ((bio = bio_list_pop(&bios))) { | |
eb2aa48d JT |
640 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
641 | if (h->tc == tc) | |
991d9fa0 JT |
642 | bio_endio(bio, DM_ENDIO_REQUEUE); |
643 | else | |
644 | bio_list_add(master, bio); | |
645 | } | |
646 | } | |
647 | ||
648 | static void requeue_io(struct thin_c *tc) | |
649 | { | |
650 | struct pool *pool = tc->pool; | |
651 | unsigned long flags; | |
652 | ||
653 | spin_lock_irqsave(&pool->lock, flags); | |
654 | __requeue_bio_list(tc, &pool->deferred_bios); | |
655 | __requeue_bio_list(tc, &pool->retry_on_resume_list); | |
656 | spin_unlock_irqrestore(&pool->lock, flags); | |
657 | } | |
658 | ||
659 | /* | |
660 | * This section of code contains the logic for processing a thin device's IO. | |
661 | * Much of the code depends on pool object resources (lists, workqueues, etc) | |
662 | * but most is exclusively called from the thin target rather than the thin-pool | |
663 | * target. | |
664 | */ | |
665 | ||
666 | static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio) | |
667 | { | |
668 | return bio->bi_sector >> tc->pool->block_shift; | |
669 | } | |
670 | ||
671 | static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block) | |
672 | { | |
673 | struct pool *pool = tc->pool; | |
674 | ||
675 | bio->bi_bdev = tc->pool_dev->bdev; | |
676 | bio->bi_sector = (block << pool->block_shift) + | |
677 | (bio->bi_sector & pool->offset_mask); | |
678 | } | |
679 | ||
2dd9c257 JT |
680 | static void remap_to_origin(struct thin_c *tc, struct bio *bio) |
681 | { | |
682 | bio->bi_bdev = tc->origin_dev->bdev; | |
683 | } | |
684 | ||
685 | static void issue(struct thin_c *tc, struct bio *bio) | |
991d9fa0 JT |
686 | { |
687 | struct pool *pool = tc->pool; | |
688 | unsigned long flags; | |
689 | ||
991d9fa0 JT |
690 | /* |
691 | * Batch together any FUA/FLUSH bios we find and then issue | |
692 | * a single commit for them in process_deferred_bios(). | |
693 | */ | |
694 | if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) { | |
695 | spin_lock_irqsave(&pool->lock, flags); | |
696 | bio_list_add(&pool->deferred_flush_bios, bio); | |
697 | spin_unlock_irqrestore(&pool->lock, flags); | |
698 | } else | |
699 | generic_make_request(bio); | |
700 | } | |
701 | ||
2dd9c257 JT |
702 | static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio) |
703 | { | |
704 | remap_to_origin(tc, bio); | |
705 | issue(tc, bio); | |
706 | } | |
707 | ||
708 | static void remap_and_issue(struct thin_c *tc, struct bio *bio, | |
709 | dm_block_t block) | |
710 | { | |
711 | remap(tc, bio, block); | |
712 | issue(tc, bio); | |
713 | } | |
714 | ||
991d9fa0 JT |
715 | /* |
716 | * wake_worker() is used when new work is queued and when pool_resume is | |
717 | * ready to continue deferred IO processing. | |
718 | */ | |
719 | static void wake_worker(struct pool *pool) | |
720 | { | |
721 | queue_work(pool->wq, &pool->worker); | |
722 | } | |
723 | ||
724 | /*----------------------------------------------------------------*/ | |
725 | ||
726 | /* | |
727 | * Bio endio functions. | |
728 | */ | |
991d9fa0 JT |
729 | struct new_mapping { |
730 | struct list_head list; | |
731 | ||
eb2aa48d JT |
732 | unsigned quiesced:1; |
733 | unsigned prepared:1; | |
104655fd | 734 | unsigned pass_discard:1; |
991d9fa0 JT |
735 | |
736 | struct thin_c *tc; | |
737 | dm_block_t virt_block; | |
738 | dm_block_t data_block; | |
104655fd | 739 | struct cell *cell, *cell2; |
991d9fa0 JT |
740 | int err; |
741 | ||
742 | /* | |
743 | * If the bio covers the whole area of a block then we can avoid | |
744 | * zeroing or copying. Instead this bio is hooked. The bio will | |
745 | * still be in the cell, so care has to be taken to avoid issuing | |
746 | * the bio twice. | |
747 | */ | |
748 | struct bio *bio; | |
749 | bio_end_io_t *saved_bi_end_io; | |
750 | }; | |
751 | ||
752 | static void __maybe_add_mapping(struct new_mapping *m) | |
753 | { | |
754 | struct pool *pool = m->tc->pool; | |
755 | ||
eb2aa48d | 756 | if (m->quiesced && m->prepared) { |
991d9fa0 JT |
757 | list_add(&m->list, &pool->prepared_mappings); |
758 | wake_worker(pool); | |
759 | } | |
760 | } | |
761 | ||
762 | static void copy_complete(int read_err, unsigned long write_err, void *context) | |
763 | { | |
764 | unsigned long flags; | |
765 | struct new_mapping *m = context; | |
766 | struct pool *pool = m->tc->pool; | |
767 | ||
768 | m->err = read_err || write_err ? -EIO : 0; | |
769 | ||
770 | spin_lock_irqsave(&pool->lock, flags); | |
771 | m->prepared = 1; | |
772 | __maybe_add_mapping(m); | |
773 | spin_unlock_irqrestore(&pool->lock, flags); | |
774 | } | |
775 | ||
776 | static void overwrite_endio(struct bio *bio, int err) | |
777 | { | |
778 | unsigned long flags; | |
eb2aa48d JT |
779 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
780 | struct new_mapping *m = h->overwrite_mapping; | |
991d9fa0 JT |
781 | struct pool *pool = m->tc->pool; |
782 | ||
783 | m->err = err; | |
784 | ||
785 | spin_lock_irqsave(&pool->lock, flags); | |
786 | m->prepared = 1; | |
787 | __maybe_add_mapping(m); | |
788 | spin_unlock_irqrestore(&pool->lock, flags); | |
789 | } | |
790 | ||
991d9fa0 JT |
791 | /*----------------------------------------------------------------*/ |
792 | ||
793 | /* | |
794 | * Workqueue. | |
795 | */ | |
796 | ||
797 | /* | |
798 | * Prepared mapping jobs. | |
799 | */ | |
800 | ||
801 | /* | |
802 | * This sends the bios in the cell back to the deferred_bios list. | |
803 | */ | |
804 | static void cell_defer(struct thin_c *tc, struct cell *cell, | |
805 | dm_block_t data_block) | |
806 | { | |
807 | struct pool *pool = tc->pool; | |
808 | unsigned long flags; | |
809 | ||
810 | spin_lock_irqsave(&pool->lock, flags); | |
811 | cell_release(cell, &pool->deferred_bios); | |
812 | spin_unlock_irqrestore(&tc->pool->lock, flags); | |
813 | ||
814 | wake_worker(pool); | |
815 | } | |
816 | ||
817 | /* | |
818 | * Same as cell_defer above, except it omits one particular detainee, | |
819 | * a write bio that covers the block and has already been processed. | |
820 | */ | |
6f94a4c4 | 821 | static void cell_defer_except(struct thin_c *tc, struct cell *cell) |
991d9fa0 JT |
822 | { |
823 | struct bio_list bios; | |
991d9fa0 JT |
824 | struct pool *pool = tc->pool; |
825 | unsigned long flags; | |
826 | ||
827 | bio_list_init(&bios); | |
991d9fa0 JT |
828 | |
829 | spin_lock_irqsave(&pool->lock, flags); | |
6f94a4c4 | 830 | cell_release_no_holder(cell, &pool->deferred_bios); |
991d9fa0 JT |
831 | spin_unlock_irqrestore(&pool->lock, flags); |
832 | ||
833 | wake_worker(pool); | |
834 | } | |
835 | ||
836 | static void process_prepared_mapping(struct new_mapping *m) | |
837 | { | |
838 | struct thin_c *tc = m->tc; | |
839 | struct bio *bio; | |
840 | int r; | |
841 | ||
842 | bio = m->bio; | |
843 | if (bio) | |
844 | bio->bi_end_io = m->saved_bi_end_io; | |
845 | ||
846 | if (m->err) { | |
847 | cell_error(m->cell); | |
848 | return; | |
849 | } | |
850 | ||
851 | /* | |
852 | * Commit the prepared block into the mapping btree. | |
853 | * Any I/O for this block arriving after this point will get | |
854 | * remapped to it directly. | |
855 | */ | |
856 | r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block); | |
857 | if (r) { | |
858 | DMERR("dm_thin_insert_block() failed"); | |
859 | cell_error(m->cell); | |
860 | return; | |
861 | } | |
862 | ||
863 | /* | |
864 | * Release any bios held while the block was being provisioned. | |
865 | * If we are processing a write bio that completely covers the block, | |
866 | * we already processed it so can ignore it now when processing | |
867 | * the bios in the cell. | |
868 | */ | |
869 | if (bio) { | |
6f94a4c4 | 870 | cell_defer_except(tc, m->cell); |
991d9fa0 JT |
871 | bio_endio(bio, 0); |
872 | } else | |
873 | cell_defer(tc, m->cell, m->data_block); | |
874 | ||
875 | list_del(&m->list); | |
876 | mempool_free(m, tc->pool->mapping_pool); | |
877 | } | |
878 | ||
104655fd JT |
879 | static void process_prepared_discard(struct new_mapping *m) |
880 | { | |
881 | int r; | |
882 | struct thin_c *tc = m->tc; | |
883 | ||
884 | r = dm_thin_remove_block(tc->td, m->virt_block); | |
885 | if (r) | |
886 | DMERR("dm_thin_remove_block() failed"); | |
887 | ||
888 | /* | |
889 | * Pass the discard down to the underlying device? | |
890 | */ | |
891 | if (m->pass_discard) | |
892 | remap_and_issue(tc, m->bio, m->data_block); | |
893 | else | |
894 | bio_endio(m->bio, 0); | |
895 | ||
896 | cell_defer_except(tc, m->cell); | |
897 | cell_defer_except(tc, m->cell2); | |
898 | mempool_free(m, tc->pool->mapping_pool); | |
899 | } | |
900 | ||
901 | static void process_prepared(struct pool *pool, struct list_head *head, | |
902 | void (*fn)(struct new_mapping *)) | |
991d9fa0 JT |
903 | { |
904 | unsigned long flags; | |
905 | struct list_head maps; | |
906 | struct new_mapping *m, *tmp; | |
907 | ||
908 | INIT_LIST_HEAD(&maps); | |
909 | spin_lock_irqsave(&pool->lock, flags); | |
104655fd | 910 | list_splice_init(head, &maps); |
991d9fa0 JT |
911 | spin_unlock_irqrestore(&pool->lock, flags); |
912 | ||
913 | list_for_each_entry_safe(m, tmp, &maps, list) | |
104655fd | 914 | fn(m); |
991d9fa0 JT |
915 | } |
916 | ||
917 | /* | |
918 | * Deferred bio jobs. | |
919 | */ | |
104655fd | 920 | static int io_overlaps_block(struct pool *pool, struct bio *bio) |
991d9fa0 | 921 | { |
104655fd | 922 | return !(bio->bi_sector & pool->offset_mask) && |
991d9fa0 | 923 | (bio->bi_size == (pool->sectors_per_block << SECTOR_SHIFT)); |
104655fd JT |
924 | |
925 | } | |
926 | ||
927 | static int io_overwrites_block(struct pool *pool, struct bio *bio) | |
928 | { | |
929 | return (bio_data_dir(bio) == WRITE) && | |
930 | io_overlaps_block(pool, bio); | |
991d9fa0 JT |
931 | } |
932 | ||
933 | static void save_and_set_endio(struct bio *bio, bio_end_io_t **save, | |
934 | bio_end_io_t *fn) | |
935 | { | |
936 | *save = bio->bi_end_io; | |
937 | bio->bi_end_io = fn; | |
938 | } | |
939 | ||
940 | static int ensure_next_mapping(struct pool *pool) | |
941 | { | |
942 | if (pool->next_mapping) | |
943 | return 0; | |
944 | ||
945 | pool->next_mapping = mempool_alloc(pool->mapping_pool, GFP_ATOMIC); | |
946 | ||
947 | return pool->next_mapping ? 0 : -ENOMEM; | |
948 | } | |
949 | ||
950 | static struct new_mapping *get_next_mapping(struct pool *pool) | |
951 | { | |
952 | struct new_mapping *r = pool->next_mapping; | |
953 | ||
954 | BUG_ON(!pool->next_mapping); | |
955 | ||
956 | pool->next_mapping = NULL; | |
957 | ||
958 | return r; | |
959 | } | |
960 | ||
961 | static void schedule_copy(struct thin_c *tc, dm_block_t virt_block, | |
2dd9c257 JT |
962 | struct dm_dev *origin, dm_block_t data_origin, |
963 | dm_block_t data_dest, | |
991d9fa0 JT |
964 | struct cell *cell, struct bio *bio) |
965 | { | |
966 | int r; | |
967 | struct pool *pool = tc->pool; | |
968 | struct new_mapping *m = get_next_mapping(pool); | |
969 | ||
970 | INIT_LIST_HEAD(&m->list); | |
eb2aa48d | 971 | m->quiesced = 0; |
991d9fa0 JT |
972 | m->prepared = 0; |
973 | m->tc = tc; | |
974 | m->virt_block = virt_block; | |
975 | m->data_block = data_dest; | |
976 | m->cell = cell; | |
977 | m->err = 0; | |
978 | m->bio = NULL; | |
979 | ||
eb2aa48d JT |
980 | if (!ds_add_work(&pool->shared_read_ds, &m->list)) |
981 | m->quiesced = 1; | |
991d9fa0 JT |
982 | |
983 | /* | |
984 | * IO to pool_dev remaps to the pool target's data_dev. | |
985 | * | |
986 | * If the whole block of data is being overwritten, we can issue the | |
987 | * bio immediately. Otherwise we use kcopyd to clone the data first. | |
988 | */ | |
989 | if (io_overwrites_block(pool, bio)) { | |
eb2aa48d JT |
990 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
991 | h->overwrite_mapping = m; | |
991d9fa0 JT |
992 | m->bio = bio; |
993 | save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio); | |
991d9fa0 JT |
994 | remap_and_issue(tc, bio, data_dest); |
995 | } else { | |
996 | struct dm_io_region from, to; | |
997 | ||
2dd9c257 | 998 | from.bdev = origin->bdev; |
991d9fa0 JT |
999 | from.sector = data_origin * pool->sectors_per_block; |
1000 | from.count = pool->sectors_per_block; | |
1001 | ||
1002 | to.bdev = tc->pool_dev->bdev; | |
1003 | to.sector = data_dest * pool->sectors_per_block; | |
1004 | to.count = pool->sectors_per_block; | |
1005 | ||
1006 | r = dm_kcopyd_copy(pool->copier, &from, 1, &to, | |
1007 | 0, copy_complete, m); | |
1008 | if (r < 0) { | |
1009 | mempool_free(m, pool->mapping_pool); | |
1010 | DMERR("dm_kcopyd_copy() failed"); | |
1011 | cell_error(cell); | |
1012 | } | |
1013 | } | |
1014 | } | |
1015 | ||
2dd9c257 JT |
1016 | static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block, |
1017 | dm_block_t data_origin, dm_block_t data_dest, | |
1018 | struct cell *cell, struct bio *bio) | |
1019 | { | |
1020 | schedule_copy(tc, virt_block, tc->pool_dev, | |
1021 | data_origin, data_dest, cell, bio); | |
1022 | } | |
1023 | ||
1024 | static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block, | |
1025 | dm_block_t data_dest, | |
1026 | struct cell *cell, struct bio *bio) | |
1027 | { | |
1028 | schedule_copy(tc, virt_block, tc->origin_dev, | |
1029 | virt_block, data_dest, cell, bio); | |
1030 | } | |
1031 | ||
991d9fa0 JT |
1032 | static void schedule_zero(struct thin_c *tc, dm_block_t virt_block, |
1033 | dm_block_t data_block, struct cell *cell, | |
1034 | struct bio *bio) | |
1035 | { | |
1036 | struct pool *pool = tc->pool; | |
1037 | struct new_mapping *m = get_next_mapping(pool); | |
1038 | ||
1039 | INIT_LIST_HEAD(&m->list); | |
eb2aa48d | 1040 | m->quiesced = 1; |
991d9fa0 JT |
1041 | m->prepared = 0; |
1042 | m->tc = tc; | |
1043 | m->virt_block = virt_block; | |
1044 | m->data_block = data_block; | |
1045 | m->cell = cell; | |
1046 | m->err = 0; | |
1047 | m->bio = NULL; | |
1048 | ||
1049 | /* | |
1050 | * If the whole block of data is being overwritten or we are not | |
1051 | * zeroing pre-existing data, we can issue the bio immediately. | |
1052 | * Otherwise we use kcopyd to zero the data first. | |
1053 | */ | |
1054 | if (!pool->zero_new_blocks) | |
1055 | process_prepared_mapping(m); | |
1056 | ||
1057 | else if (io_overwrites_block(pool, bio)) { | |
eb2aa48d JT |
1058 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
1059 | h->overwrite_mapping = m; | |
991d9fa0 JT |
1060 | m->bio = bio; |
1061 | save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio); | |
991d9fa0 JT |
1062 | remap_and_issue(tc, bio, data_block); |
1063 | ||
1064 | } else { | |
1065 | int r; | |
1066 | struct dm_io_region to; | |
1067 | ||
1068 | to.bdev = tc->pool_dev->bdev; | |
1069 | to.sector = data_block * pool->sectors_per_block; | |
1070 | to.count = pool->sectors_per_block; | |
1071 | ||
1072 | r = dm_kcopyd_zero(pool->copier, 1, &to, 0, copy_complete, m); | |
1073 | if (r < 0) { | |
1074 | mempool_free(m, pool->mapping_pool); | |
1075 | DMERR("dm_kcopyd_zero() failed"); | |
1076 | cell_error(cell); | |
1077 | } | |
1078 | } | |
1079 | } | |
1080 | ||
1081 | static int alloc_data_block(struct thin_c *tc, dm_block_t *result) | |
1082 | { | |
1083 | int r; | |
1084 | dm_block_t free_blocks; | |
1085 | unsigned long flags; | |
1086 | struct pool *pool = tc->pool; | |
1087 | ||
1088 | r = dm_pool_get_free_block_count(pool->pmd, &free_blocks); | |
1089 | if (r) | |
1090 | return r; | |
1091 | ||
1092 | if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) { | |
1093 | DMWARN("%s: reached low water mark, sending event.", | |
1094 | dm_device_name(pool->pool_md)); | |
1095 | spin_lock_irqsave(&pool->lock, flags); | |
1096 | pool->low_water_triggered = 1; | |
1097 | spin_unlock_irqrestore(&pool->lock, flags); | |
1098 | dm_table_event(pool->ti->table); | |
1099 | } | |
1100 | ||
1101 | if (!free_blocks) { | |
1102 | if (pool->no_free_space) | |
1103 | return -ENOSPC; | |
1104 | else { | |
1105 | /* | |
1106 | * Try to commit to see if that will free up some | |
1107 | * more space. | |
1108 | */ | |
1109 | r = dm_pool_commit_metadata(pool->pmd); | |
1110 | if (r) { | |
1111 | DMERR("%s: dm_pool_commit_metadata() failed, error = %d", | |
1112 | __func__, r); | |
1113 | return r; | |
1114 | } | |
1115 | ||
1116 | r = dm_pool_get_free_block_count(pool->pmd, &free_blocks); | |
1117 | if (r) | |
1118 | return r; | |
1119 | ||
1120 | /* | |
1121 | * If we still have no space we set a flag to avoid | |
1122 | * doing all this checking and return -ENOSPC. | |
1123 | */ | |
1124 | if (!free_blocks) { | |
1125 | DMWARN("%s: no free space available.", | |
1126 | dm_device_name(pool->pool_md)); | |
1127 | spin_lock_irqsave(&pool->lock, flags); | |
1128 | pool->no_free_space = 1; | |
1129 | spin_unlock_irqrestore(&pool->lock, flags); | |
1130 | return -ENOSPC; | |
1131 | } | |
1132 | } | |
1133 | } | |
1134 | ||
1135 | r = dm_pool_alloc_data_block(pool->pmd, result); | |
1136 | if (r) | |
1137 | return r; | |
1138 | ||
1139 | return 0; | |
1140 | } | |
1141 | ||
1142 | /* | |
1143 | * If we have run out of space, queue bios until the device is | |
1144 | * resumed, presumably after having been reloaded with more space. | |
1145 | */ | |
1146 | static void retry_on_resume(struct bio *bio) | |
1147 | { | |
eb2aa48d JT |
1148 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
1149 | struct thin_c *tc = h->tc; | |
991d9fa0 JT |
1150 | struct pool *pool = tc->pool; |
1151 | unsigned long flags; | |
1152 | ||
1153 | spin_lock_irqsave(&pool->lock, flags); | |
1154 | bio_list_add(&pool->retry_on_resume_list, bio); | |
1155 | spin_unlock_irqrestore(&pool->lock, flags); | |
1156 | } | |
1157 | ||
1158 | static void no_space(struct cell *cell) | |
1159 | { | |
1160 | struct bio *bio; | |
1161 | struct bio_list bios; | |
1162 | ||
1163 | bio_list_init(&bios); | |
1164 | cell_release(cell, &bios); | |
1165 | ||
1166 | while ((bio = bio_list_pop(&bios))) | |
1167 | retry_on_resume(bio); | |
1168 | } | |
1169 | ||
104655fd JT |
1170 | static void process_discard(struct thin_c *tc, struct bio *bio) |
1171 | { | |
1172 | int r; | |
1173 | struct pool *pool = tc->pool; | |
1174 | struct cell *cell, *cell2; | |
1175 | struct cell_key key, key2; | |
1176 | dm_block_t block = get_bio_block(tc, bio); | |
1177 | struct dm_thin_lookup_result lookup_result; | |
1178 | struct new_mapping *m; | |
1179 | ||
1180 | build_virtual_key(tc->td, block, &key); | |
1181 | if (bio_detain(tc->pool->prison, &key, bio, &cell)) | |
1182 | return; | |
1183 | ||
1184 | r = dm_thin_find_block(tc->td, block, 1, &lookup_result); | |
1185 | switch (r) { | |
1186 | case 0: | |
1187 | /* | |
1188 | * Check nobody is fiddling with this pool block. This can | |
1189 | * happen if someone's in the process of breaking sharing | |
1190 | * on this block. | |
1191 | */ | |
1192 | build_data_key(tc->td, lookup_result.block, &key2); | |
1193 | if (bio_detain(tc->pool->prison, &key2, bio, &cell2)) { | |
1194 | cell_release_singleton(cell, bio); | |
1195 | break; | |
1196 | } | |
1197 | ||
1198 | if (io_overlaps_block(pool, bio)) { | |
1199 | /* | |
1200 | * IO may still be going to the destination block. We must | |
1201 | * quiesce before we can do the removal. | |
1202 | */ | |
1203 | m = get_next_mapping(pool); | |
1204 | m->tc = tc; | |
1205 | m->pass_discard = !lookup_result.shared; | |
1206 | m->virt_block = block; | |
1207 | m->data_block = lookup_result.block; | |
1208 | m->cell = cell; | |
1209 | m->cell2 = cell2; | |
1210 | m->err = 0; | |
1211 | m->bio = bio; | |
1212 | ||
1213 | if (!ds_add_work(&pool->all_io_ds, &m->list)) { | |
1214 | list_add(&m->list, &pool->prepared_discards); | |
1215 | wake_worker(pool); | |
1216 | } | |
1217 | } else { | |
1218 | /* | |
1219 | * This path is hit if people are ignoring | |
1220 | * limits->discard_granularity. It ignores any | |
1221 | * part of the discard that is in a subsequent | |
1222 | * block. | |
1223 | */ | |
1224 | sector_t offset = bio->bi_sector - (block << pool->block_shift); | |
1225 | unsigned remaining = (pool->sectors_per_block - offset) << 9; | |
1226 | bio->bi_size = min(bio->bi_size, remaining); | |
1227 | ||
1228 | cell_release_singleton(cell, bio); | |
1229 | cell_release_singleton(cell2, bio); | |
1230 | remap_and_issue(tc, bio, lookup_result.block); | |
1231 | } | |
1232 | break; | |
1233 | ||
1234 | case -ENODATA: | |
1235 | /* | |
1236 | * It isn't provisioned, just forget it. | |
1237 | */ | |
1238 | cell_release_singleton(cell, bio); | |
1239 | bio_endio(bio, 0); | |
1240 | break; | |
1241 | ||
1242 | default: | |
1243 | DMERR("discard: find block unexpectedly returned %d", r); | |
1244 | cell_release_singleton(cell, bio); | |
1245 | bio_io_error(bio); | |
1246 | break; | |
1247 | } | |
1248 | } | |
1249 | ||
991d9fa0 JT |
1250 | static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block, |
1251 | struct cell_key *key, | |
1252 | struct dm_thin_lookup_result *lookup_result, | |
1253 | struct cell *cell) | |
1254 | { | |
1255 | int r; | |
1256 | dm_block_t data_block; | |
1257 | ||
1258 | r = alloc_data_block(tc, &data_block); | |
1259 | switch (r) { | |
1260 | case 0: | |
2dd9c257 JT |
1261 | schedule_internal_copy(tc, block, lookup_result->block, |
1262 | data_block, cell, bio); | |
991d9fa0 JT |
1263 | break; |
1264 | ||
1265 | case -ENOSPC: | |
1266 | no_space(cell); | |
1267 | break; | |
1268 | ||
1269 | default: | |
1270 | DMERR("%s: alloc_data_block() failed, error = %d", __func__, r); | |
1271 | cell_error(cell); | |
1272 | break; | |
1273 | } | |
1274 | } | |
1275 | ||
1276 | static void process_shared_bio(struct thin_c *tc, struct bio *bio, | |
1277 | dm_block_t block, | |
1278 | struct dm_thin_lookup_result *lookup_result) | |
1279 | { | |
1280 | struct cell *cell; | |
1281 | struct pool *pool = tc->pool; | |
1282 | struct cell_key key; | |
1283 | ||
1284 | /* | |
1285 | * If cell is already occupied, then sharing is already in the process | |
1286 | * of being broken so we have nothing further to do here. | |
1287 | */ | |
1288 | build_data_key(tc->td, lookup_result->block, &key); | |
1289 | if (bio_detain(pool->prison, &key, bio, &cell)) | |
1290 | return; | |
1291 | ||
1292 | if (bio_data_dir(bio) == WRITE) | |
1293 | break_sharing(tc, bio, block, &key, lookup_result, cell); | |
1294 | else { | |
eb2aa48d | 1295 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
991d9fa0 | 1296 | |
eb2aa48d | 1297 | h->shared_read_entry = ds_inc(&pool->shared_read_ds); |
991d9fa0 JT |
1298 | |
1299 | cell_release_singleton(cell, bio); | |
1300 | remap_and_issue(tc, bio, lookup_result->block); | |
1301 | } | |
1302 | } | |
1303 | ||
1304 | static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block, | |
1305 | struct cell *cell) | |
1306 | { | |
1307 | int r; | |
1308 | dm_block_t data_block; | |
1309 | ||
1310 | /* | |
1311 | * Remap empty bios (flushes) immediately, without provisioning. | |
1312 | */ | |
1313 | if (!bio->bi_size) { | |
1314 | cell_release_singleton(cell, bio); | |
1315 | remap_and_issue(tc, bio, 0); | |
1316 | return; | |
1317 | } | |
1318 | ||
1319 | /* | |
1320 | * Fill read bios with zeroes and complete them immediately. | |
1321 | */ | |
1322 | if (bio_data_dir(bio) == READ) { | |
1323 | zero_fill_bio(bio); | |
1324 | cell_release_singleton(cell, bio); | |
1325 | bio_endio(bio, 0); | |
1326 | return; | |
1327 | } | |
1328 | ||
1329 | r = alloc_data_block(tc, &data_block); | |
1330 | switch (r) { | |
1331 | case 0: | |
2dd9c257 JT |
1332 | if (tc->origin_dev) |
1333 | schedule_external_copy(tc, block, data_block, cell, bio); | |
1334 | else | |
1335 | schedule_zero(tc, block, data_block, cell, bio); | |
991d9fa0 JT |
1336 | break; |
1337 | ||
1338 | case -ENOSPC: | |
1339 | no_space(cell); | |
1340 | break; | |
1341 | ||
1342 | default: | |
1343 | DMERR("%s: alloc_data_block() failed, error = %d", __func__, r); | |
1344 | cell_error(cell); | |
1345 | break; | |
1346 | } | |
1347 | } | |
1348 | ||
1349 | static void process_bio(struct thin_c *tc, struct bio *bio) | |
1350 | { | |
1351 | int r; | |
1352 | dm_block_t block = get_bio_block(tc, bio); | |
1353 | struct cell *cell; | |
1354 | struct cell_key key; | |
1355 | struct dm_thin_lookup_result lookup_result; | |
1356 | ||
1357 | /* | |
1358 | * If cell is already occupied, then the block is already | |
1359 | * being provisioned so we have nothing further to do here. | |
1360 | */ | |
1361 | build_virtual_key(tc->td, block, &key); | |
1362 | if (bio_detain(tc->pool->prison, &key, bio, &cell)) | |
1363 | return; | |
1364 | ||
1365 | r = dm_thin_find_block(tc->td, block, 1, &lookup_result); | |
1366 | switch (r) { | |
1367 | case 0: | |
1368 | /* | |
1369 | * We can release this cell now. This thread is the only | |
1370 | * one that puts bios into a cell, and we know there were | |
1371 | * no preceding bios. | |
1372 | */ | |
1373 | /* | |
1374 | * TODO: this will probably have to change when discard goes | |
1375 | * back in. | |
1376 | */ | |
1377 | cell_release_singleton(cell, bio); | |
1378 | ||
1379 | if (lookup_result.shared) | |
1380 | process_shared_bio(tc, bio, block, &lookup_result); | |
1381 | else | |
1382 | remap_and_issue(tc, bio, lookup_result.block); | |
1383 | break; | |
1384 | ||
1385 | case -ENODATA: | |
2dd9c257 JT |
1386 | if (bio_data_dir(bio) == READ && tc->origin_dev) { |
1387 | cell_release_singleton(cell, bio); | |
1388 | remap_to_origin_and_issue(tc, bio); | |
1389 | } else | |
1390 | provision_block(tc, bio, block, cell); | |
991d9fa0 JT |
1391 | break; |
1392 | ||
1393 | default: | |
1394 | DMERR("dm_thin_find_block() failed, error = %d", r); | |
104655fd | 1395 | cell_release_singleton(cell, bio); |
991d9fa0 JT |
1396 | bio_io_error(bio); |
1397 | break; | |
1398 | } | |
1399 | } | |
1400 | ||
905e51b3 JT |
1401 | static int need_commit_due_to_time(struct pool *pool) |
1402 | { | |
1403 | return jiffies < pool->last_commit_jiffies || | |
1404 | jiffies > pool->last_commit_jiffies + COMMIT_PERIOD; | |
1405 | } | |
1406 | ||
991d9fa0 JT |
1407 | static void process_deferred_bios(struct pool *pool) |
1408 | { | |
1409 | unsigned long flags; | |
1410 | struct bio *bio; | |
1411 | struct bio_list bios; | |
1412 | int r; | |
1413 | ||
1414 | bio_list_init(&bios); | |
1415 | ||
1416 | spin_lock_irqsave(&pool->lock, flags); | |
1417 | bio_list_merge(&bios, &pool->deferred_bios); | |
1418 | bio_list_init(&pool->deferred_bios); | |
1419 | spin_unlock_irqrestore(&pool->lock, flags); | |
1420 | ||
1421 | while ((bio = bio_list_pop(&bios))) { | |
eb2aa48d JT |
1422 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
1423 | struct thin_c *tc = h->tc; | |
1424 | ||
991d9fa0 JT |
1425 | /* |
1426 | * If we've got no free new_mapping structs, and processing | |
1427 | * this bio might require one, we pause until there are some | |
1428 | * prepared mappings to process. | |
1429 | */ | |
1430 | if (ensure_next_mapping(pool)) { | |
1431 | spin_lock_irqsave(&pool->lock, flags); | |
1432 | bio_list_merge(&pool->deferred_bios, &bios); | |
1433 | spin_unlock_irqrestore(&pool->lock, flags); | |
1434 | ||
1435 | break; | |
1436 | } | |
104655fd JT |
1437 | |
1438 | if (bio->bi_rw & REQ_DISCARD) | |
1439 | process_discard(tc, bio); | |
1440 | else | |
1441 | process_bio(tc, bio); | |
991d9fa0 JT |
1442 | } |
1443 | ||
1444 | /* | |
1445 | * If there are any deferred flush bios, we must commit | |
1446 | * the metadata before issuing them. | |
1447 | */ | |
1448 | bio_list_init(&bios); | |
1449 | spin_lock_irqsave(&pool->lock, flags); | |
1450 | bio_list_merge(&bios, &pool->deferred_flush_bios); | |
1451 | bio_list_init(&pool->deferred_flush_bios); | |
1452 | spin_unlock_irqrestore(&pool->lock, flags); | |
1453 | ||
905e51b3 | 1454 | if (bio_list_empty(&bios) && !need_commit_due_to_time(pool)) |
991d9fa0 JT |
1455 | return; |
1456 | ||
1457 | r = dm_pool_commit_metadata(pool->pmd); | |
1458 | if (r) { | |
1459 | DMERR("%s: dm_pool_commit_metadata() failed, error = %d", | |
1460 | __func__, r); | |
1461 | while ((bio = bio_list_pop(&bios))) | |
1462 | bio_io_error(bio); | |
1463 | return; | |
1464 | } | |
905e51b3 | 1465 | pool->last_commit_jiffies = jiffies; |
991d9fa0 JT |
1466 | |
1467 | while ((bio = bio_list_pop(&bios))) | |
1468 | generic_make_request(bio); | |
1469 | } | |
1470 | ||
1471 | static void do_worker(struct work_struct *ws) | |
1472 | { | |
1473 | struct pool *pool = container_of(ws, struct pool, worker); | |
1474 | ||
104655fd JT |
1475 | process_prepared(pool, &pool->prepared_mappings, process_prepared_mapping); |
1476 | process_prepared(pool, &pool->prepared_discards, process_prepared_discard); | |
991d9fa0 JT |
1477 | process_deferred_bios(pool); |
1478 | } | |
1479 | ||
905e51b3 JT |
1480 | /* |
1481 | * We want to commit periodically so that not too much | |
1482 | * unwritten data builds up. | |
1483 | */ | |
1484 | static void do_waker(struct work_struct *ws) | |
1485 | { | |
1486 | struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker); | |
1487 | wake_worker(pool); | |
1488 | queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD); | |
1489 | } | |
1490 | ||
991d9fa0 JT |
1491 | /*----------------------------------------------------------------*/ |
1492 | ||
1493 | /* | |
1494 | * Mapping functions. | |
1495 | */ | |
1496 | ||
1497 | /* | |
1498 | * Called only while mapping a thin bio to hand it over to the workqueue. | |
1499 | */ | |
1500 | static void thin_defer_bio(struct thin_c *tc, struct bio *bio) | |
1501 | { | |
1502 | unsigned long flags; | |
1503 | struct pool *pool = tc->pool; | |
1504 | ||
1505 | spin_lock_irqsave(&pool->lock, flags); | |
1506 | bio_list_add(&pool->deferred_bios, bio); | |
1507 | spin_unlock_irqrestore(&pool->lock, flags); | |
1508 | ||
1509 | wake_worker(pool); | |
1510 | } | |
1511 | ||
eb2aa48d JT |
1512 | static struct endio_hook *thin_hook_bio(struct thin_c *tc, struct bio *bio) |
1513 | { | |
1514 | struct pool *pool = tc->pool; | |
1515 | struct endio_hook *h = mempool_alloc(pool->endio_hook_pool, GFP_NOIO); | |
1516 | ||
1517 | h->tc = tc; | |
1518 | h->shared_read_entry = NULL; | |
104655fd | 1519 | h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : ds_inc(&pool->all_io_ds); |
eb2aa48d JT |
1520 | h->overwrite_mapping = NULL; |
1521 | ||
1522 | return h; | |
1523 | } | |
1524 | ||
991d9fa0 JT |
1525 | /* |
1526 | * Non-blocking function called from the thin target's map function. | |
1527 | */ | |
1528 | static int thin_bio_map(struct dm_target *ti, struct bio *bio, | |
1529 | union map_info *map_context) | |
1530 | { | |
1531 | int r; | |
1532 | struct thin_c *tc = ti->private; | |
1533 | dm_block_t block = get_bio_block(tc, bio); | |
1534 | struct dm_thin_device *td = tc->td; | |
1535 | struct dm_thin_lookup_result result; | |
1536 | ||
eb2aa48d | 1537 | map_context->ptr = thin_hook_bio(tc, bio); |
104655fd | 1538 | if (bio->bi_rw & (REQ_DISCARD | REQ_FLUSH | REQ_FUA)) { |
991d9fa0 JT |
1539 | thin_defer_bio(tc, bio); |
1540 | return DM_MAPIO_SUBMITTED; | |
1541 | } | |
1542 | ||
1543 | r = dm_thin_find_block(td, block, 0, &result); | |
1544 | ||
1545 | /* | |
1546 | * Note that we defer readahead too. | |
1547 | */ | |
1548 | switch (r) { | |
1549 | case 0: | |
1550 | if (unlikely(result.shared)) { | |
1551 | /* | |
1552 | * We have a race condition here between the | |
1553 | * result.shared value returned by the lookup and | |
1554 | * snapshot creation, which may cause new | |
1555 | * sharing. | |
1556 | * | |
1557 | * To avoid this always quiesce the origin before | |
1558 | * taking the snap. You want to do this anyway to | |
1559 | * ensure a consistent application view | |
1560 | * (i.e. lockfs). | |
1561 | * | |
1562 | * More distant ancestors are irrelevant. The | |
1563 | * shared flag will be set in their case. | |
1564 | */ | |
1565 | thin_defer_bio(tc, bio); | |
1566 | r = DM_MAPIO_SUBMITTED; | |
1567 | } else { | |
1568 | remap(tc, bio, result.block); | |
1569 | r = DM_MAPIO_REMAPPED; | |
1570 | } | |
1571 | break; | |
1572 | ||
1573 | case -ENODATA: | |
1574 | /* | |
1575 | * In future, the failed dm_thin_find_block above could | |
1576 | * provide the hint to load the metadata into cache. | |
1577 | */ | |
1578 | case -EWOULDBLOCK: | |
1579 | thin_defer_bio(tc, bio); | |
1580 | r = DM_MAPIO_SUBMITTED; | |
1581 | break; | |
1582 | } | |
1583 | ||
1584 | return r; | |
1585 | } | |
1586 | ||
1587 | static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits) | |
1588 | { | |
1589 | int r; | |
1590 | unsigned long flags; | |
1591 | struct pool_c *pt = container_of(cb, struct pool_c, callbacks); | |
1592 | ||
1593 | spin_lock_irqsave(&pt->pool->lock, flags); | |
1594 | r = !bio_list_empty(&pt->pool->retry_on_resume_list); | |
1595 | spin_unlock_irqrestore(&pt->pool->lock, flags); | |
1596 | ||
1597 | if (!r) { | |
1598 | struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); | |
1599 | r = bdi_congested(&q->backing_dev_info, bdi_bits); | |
1600 | } | |
1601 | ||
1602 | return r; | |
1603 | } | |
1604 | ||
1605 | static void __requeue_bios(struct pool *pool) | |
1606 | { | |
1607 | bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list); | |
1608 | bio_list_init(&pool->retry_on_resume_list); | |
1609 | } | |
1610 | ||
1611 | /*---------------------------------------------------------------- | |
1612 | * Binding of control targets to a pool object | |
1613 | *--------------------------------------------------------------*/ | |
1614 | static int bind_control_target(struct pool *pool, struct dm_target *ti) | |
1615 | { | |
1616 | struct pool_c *pt = ti->private; | |
1617 | ||
1618 | pool->ti = ti; | |
1619 | pool->low_water_blocks = pt->low_water_blocks; | |
1620 | pool->zero_new_blocks = pt->zero_new_blocks; | |
1621 | ||
1622 | return 0; | |
1623 | } | |
1624 | ||
1625 | static void unbind_control_target(struct pool *pool, struct dm_target *ti) | |
1626 | { | |
1627 | if (pool->ti == ti) | |
1628 | pool->ti = NULL; | |
1629 | } | |
1630 | ||
1631 | /*---------------------------------------------------------------- | |
1632 | * Pool creation | |
1633 | *--------------------------------------------------------------*/ | |
1634 | static void __pool_destroy(struct pool *pool) | |
1635 | { | |
1636 | __pool_table_remove(pool); | |
1637 | ||
1638 | if (dm_pool_metadata_close(pool->pmd) < 0) | |
1639 | DMWARN("%s: dm_pool_metadata_close() failed.", __func__); | |
1640 | ||
1641 | prison_destroy(pool->prison); | |
1642 | dm_kcopyd_client_destroy(pool->copier); | |
1643 | ||
1644 | if (pool->wq) | |
1645 | destroy_workqueue(pool->wq); | |
1646 | ||
1647 | if (pool->next_mapping) | |
1648 | mempool_free(pool->next_mapping, pool->mapping_pool); | |
1649 | mempool_destroy(pool->mapping_pool); | |
1650 | mempool_destroy(pool->endio_hook_pool); | |
1651 | kfree(pool); | |
1652 | } | |
1653 | ||
1654 | static struct pool *pool_create(struct mapped_device *pool_md, | |
1655 | struct block_device *metadata_dev, | |
1656 | unsigned long block_size, char **error) | |
1657 | { | |
1658 | int r; | |
1659 | void *err_p; | |
1660 | struct pool *pool; | |
1661 | struct dm_pool_metadata *pmd; | |
1662 | ||
1663 | pmd = dm_pool_metadata_open(metadata_dev, block_size); | |
1664 | if (IS_ERR(pmd)) { | |
1665 | *error = "Error creating metadata object"; | |
1666 | return (struct pool *)pmd; | |
1667 | } | |
1668 | ||
1669 | pool = kmalloc(sizeof(*pool), GFP_KERNEL); | |
1670 | if (!pool) { | |
1671 | *error = "Error allocating memory for pool"; | |
1672 | err_p = ERR_PTR(-ENOMEM); | |
1673 | goto bad_pool; | |
1674 | } | |
1675 | ||
1676 | pool->pmd = pmd; | |
1677 | pool->sectors_per_block = block_size; | |
1678 | pool->block_shift = ffs(block_size) - 1; | |
1679 | pool->offset_mask = block_size - 1; | |
1680 | pool->low_water_blocks = 0; | |
1681 | pool->zero_new_blocks = 1; | |
1682 | pool->prison = prison_create(PRISON_CELLS); | |
1683 | if (!pool->prison) { | |
1684 | *error = "Error creating pool's bio prison"; | |
1685 | err_p = ERR_PTR(-ENOMEM); | |
1686 | goto bad_prison; | |
1687 | } | |
1688 | ||
1689 | pool->copier = dm_kcopyd_client_create(); | |
1690 | if (IS_ERR(pool->copier)) { | |
1691 | r = PTR_ERR(pool->copier); | |
1692 | *error = "Error creating pool's kcopyd client"; | |
1693 | err_p = ERR_PTR(r); | |
1694 | goto bad_kcopyd_client; | |
1695 | } | |
1696 | ||
1697 | /* | |
1698 | * Create singlethreaded workqueue that will service all devices | |
1699 | * that use this metadata. | |
1700 | */ | |
1701 | pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); | |
1702 | if (!pool->wq) { | |
1703 | *error = "Error creating pool's workqueue"; | |
1704 | err_p = ERR_PTR(-ENOMEM); | |
1705 | goto bad_wq; | |
1706 | } | |
1707 | ||
1708 | INIT_WORK(&pool->worker, do_worker); | |
905e51b3 | 1709 | INIT_DELAYED_WORK(&pool->waker, do_waker); |
991d9fa0 JT |
1710 | spin_lock_init(&pool->lock); |
1711 | bio_list_init(&pool->deferred_bios); | |
1712 | bio_list_init(&pool->deferred_flush_bios); | |
1713 | INIT_LIST_HEAD(&pool->prepared_mappings); | |
104655fd | 1714 | INIT_LIST_HEAD(&pool->prepared_discards); |
991d9fa0 JT |
1715 | pool->low_water_triggered = 0; |
1716 | pool->no_free_space = 0; | |
1717 | bio_list_init(&pool->retry_on_resume_list); | |
eb2aa48d | 1718 | ds_init(&pool->shared_read_ds); |
104655fd | 1719 | ds_init(&pool->all_io_ds); |
991d9fa0 JT |
1720 | |
1721 | pool->next_mapping = NULL; | |
1722 | pool->mapping_pool = | |
1723 | mempool_create_kmalloc_pool(MAPPING_POOL_SIZE, sizeof(struct new_mapping)); | |
1724 | if (!pool->mapping_pool) { | |
1725 | *error = "Error creating pool's mapping mempool"; | |
1726 | err_p = ERR_PTR(-ENOMEM); | |
1727 | goto bad_mapping_pool; | |
1728 | } | |
1729 | ||
1730 | pool->endio_hook_pool = | |
1731 | mempool_create_kmalloc_pool(ENDIO_HOOK_POOL_SIZE, sizeof(struct endio_hook)); | |
1732 | if (!pool->endio_hook_pool) { | |
1733 | *error = "Error creating pool's endio_hook mempool"; | |
1734 | err_p = ERR_PTR(-ENOMEM); | |
1735 | goto bad_endio_hook_pool; | |
1736 | } | |
1737 | pool->ref_count = 1; | |
905e51b3 | 1738 | pool->last_commit_jiffies = jiffies; |
991d9fa0 JT |
1739 | pool->pool_md = pool_md; |
1740 | pool->md_dev = metadata_dev; | |
1741 | __pool_table_insert(pool); | |
1742 | ||
1743 | return pool; | |
1744 | ||
1745 | bad_endio_hook_pool: | |
1746 | mempool_destroy(pool->mapping_pool); | |
1747 | bad_mapping_pool: | |
1748 | destroy_workqueue(pool->wq); | |
1749 | bad_wq: | |
1750 | dm_kcopyd_client_destroy(pool->copier); | |
1751 | bad_kcopyd_client: | |
1752 | prison_destroy(pool->prison); | |
1753 | bad_prison: | |
1754 | kfree(pool); | |
1755 | bad_pool: | |
1756 | if (dm_pool_metadata_close(pmd)) | |
1757 | DMWARN("%s: dm_pool_metadata_close() failed.", __func__); | |
1758 | ||
1759 | return err_p; | |
1760 | } | |
1761 | ||
1762 | static void __pool_inc(struct pool *pool) | |
1763 | { | |
1764 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
1765 | pool->ref_count++; | |
1766 | } | |
1767 | ||
1768 | static void __pool_dec(struct pool *pool) | |
1769 | { | |
1770 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
1771 | BUG_ON(!pool->ref_count); | |
1772 | if (!--pool->ref_count) | |
1773 | __pool_destroy(pool); | |
1774 | } | |
1775 | ||
1776 | static struct pool *__pool_find(struct mapped_device *pool_md, | |
1777 | struct block_device *metadata_dev, | |
1778 | unsigned long block_size, char **error) | |
1779 | { | |
1780 | struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev); | |
1781 | ||
1782 | if (pool) { | |
1783 | if (pool->pool_md != pool_md) | |
1784 | return ERR_PTR(-EBUSY); | |
1785 | __pool_inc(pool); | |
1786 | ||
1787 | } else { | |
1788 | pool = __pool_table_lookup(pool_md); | |
1789 | if (pool) { | |
1790 | if (pool->md_dev != metadata_dev) | |
1791 | return ERR_PTR(-EINVAL); | |
1792 | __pool_inc(pool); | |
1793 | ||
1794 | } else | |
1795 | pool = pool_create(pool_md, metadata_dev, block_size, error); | |
1796 | } | |
1797 | ||
1798 | return pool; | |
1799 | } | |
1800 | ||
1801 | /*---------------------------------------------------------------- | |
1802 | * Pool target methods | |
1803 | *--------------------------------------------------------------*/ | |
1804 | static void pool_dtr(struct dm_target *ti) | |
1805 | { | |
1806 | struct pool_c *pt = ti->private; | |
1807 | ||
1808 | mutex_lock(&dm_thin_pool_table.mutex); | |
1809 | ||
1810 | unbind_control_target(pt->pool, ti); | |
1811 | __pool_dec(pt->pool); | |
1812 | dm_put_device(ti, pt->metadata_dev); | |
1813 | dm_put_device(ti, pt->data_dev); | |
1814 | kfree(pt); | |
1815 | ||
1816 | mutex_unlock(&dm_thin_pool_table.mutex); | |
1817 | } | |
1818 | ||
1819 | struct pool_features { | |
1820 | unsigned zero_new_blocks:1; | |
1821 | }; | |
1822 | ||
1823 | static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf, | |
1824 | struct dm_target *ti) | |
1825 | { | |
1826 | int r; | |
1827 | unsigned argc; | |
1828 | const char *arg_name; | |
1829 | ||
1830 | static struct dm_arg _args[] = { | |
1831 | {0, 1, "Invalid number of pool feature arguments"}, | |
1832 | }; | |
1833 | ||
1834 | /* | |
1835 | * No feature arguments supplied. | |
1836 | */ | |
1837 | if (!as->argc) | |
1838 | return 0; | |
1839 | ||
1840 | r = dm_read_arg_group(_args, as, &argc, &ti->error); | |
1841 | if (r) | |
1842 | return -EINVAL; | |
1843 | ||
1844 | while (argc && !r) { | |
1845 | arg_name = dm_shift_arg(as); | |
1846 | argc--; | |
1847 | ||
1848 | if (!strcasecmp(arg_name, "skip_block_zeroing")) { | |
1849 | pf->zero_new_blocks = 0; | |
1850 | continue; | |
1851 | } | |
1852 | ||
1853 | ti->error = "Unrecognised pool feature requested"; | |
1854 | r = -EINVAL; | |
1855 | } | |
1856 | ||
1857 | return r; | |
1858 | } | |
1859 | ||
1860 | /* | |
1861 | * thin-pool <metadata dev> <data dev> | |
1862 | * <data block size (sectors)> | |
1863 | * <low water mark (blocks)> | |
1864 | * [<#feature args> [<arg>]*] | |
1865 | * | |
1866 | * Optional feature arguments are: | |
1867 | * skip_block_zeroing: skips the zeroing of newly-provisioned blocks. | |
1868 | */ | |
1869 | static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
1870 | { | |
1871 | int r; | |
1872 | struct pool_c *pt; | |
1873 | struct pool *pool; | |
1874 | struct pool_features pf; | |
1875 | struct dm_arg_set as; | |
1876 | struct dm_dev *data_dev; | |
1877 | unsigned long block_size; | |
1878 | dm_block_t low_water_blocks; | |
1879 | struct dm_dev *metadata_dev; | |
1880 | sector_t metadata_dev_size; | |
c4a69ecd | 1881 | char b[BDEVNAME_SIZE]; |
991d9fa0 JT |
1882 | |
1883 | /* | |
1884 | * FIXME Remove validation from scope of lock. | |
1885 | */ | |
1886 | mutex_lock(&dm_thin_pool_table.mutex); | |
1887 | ||
1888 | if (argc < 4) { | |
1889 | ti->error = "Invalid argument count"; | |
1890 | r = -EINVAL; | |
1891 | goto out_unlock; | |
1892 | } | |
1893 | as.argc = argc; | |
1894 | as.argv = argv; | |
1895 | ||
1896 | r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &metadata_dev); | |
1897 | if (r) { | |
1898 | ti->error = "Error opening metadata block device"; | |
1899 | goto out_unlock; | |
1900 | } | |
1901 | ||
1902 | metadata_dev_size = i_size_read(metadata_dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
c4a69ecd MS |
1903 | if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING) |
1904 | DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.", | |
1905 | bdevname(metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS); | |
991d9fa0 JT |
1906 | |
1907 | r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev); | |
1908 | if (r) { | |
1909 | ti->error = "Error getting data device"; | |
1910 | goto out_metadata; | |
1911 | } | |
1912 | ||
1913 | if (kstrtoul(argv[2], 10, &block_size) || !block_size || | |
1914 | block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS || | |
1915 | block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS || | |
1916 | !is_power_of_2(block_size)) { | |
1917 | ti->error = "Invalid block size"; | |
1918 | r = -EINVAL; | |
1919 | goto out; | |
1920 | } | |
1921 | ||
1922 | if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) { | |
1923 | ti->error = "Invalid low water mark"; | |
1924 | r = -EINVAL; | |
1925 | goto out; | |
1926 | } | |
1927 | ||
1928 | /* | |
1929 | * Set default pool features. | |
1930 | */ | |
1931 | memset(&pf, 0, sizeof(pf)); | |
1932 | pf.zero_new_blocks = 1; | |
1933 | ||
1934 | dm_consume_args(&as, 4); | |
1935 | r = parse_pool_features(&as, &pf, ti); | |
1936 | if (r) | |
1937 | goto out; | |
1938 | ||
1939 | pt = kzalloc(sizeof(*pt), GFP_KERNEL); | |
1940 | if (!pt) { | |
1941 | r = -ENOMEM; | |
1942 | goto out; | |
1943 | } | |
1944 | ||
1945 | pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev, | |
1946 | block_size, &ti->error); | |
1947 | if (IS_ERR(pool)) { | |
1948 | r = PTR_ERR(pool); | |
1949 | goto out_free_pt; | |
1950 | } | |
1951 | ||
1952 | pt->pool = pool; | |
1953 | pt->ti = ti; | |
1954 | pt->metadata_dev = metadata_dev; | |
1955 | pt->data_dev = data_dev; | |
1956 | pt->low_water_blocks = low_water_blocks; | |
1957 | pt->zero_new_blocks = pf.zero_new_blocks; | |
1958 | ti->num_flush_requests = 1; | |
104655fd JT |
1959 | ti->num_discard_requests = 1; |
1960 | ti->discards_supported = 1; | |
991d9fa0 JT |
1961 | ti->private = pt; |
1962 | ||
1963 | pt->callbacks.congested_fn = pool_is_congested; | |
1964 | dm_table_add_target_callbacks(ti->table, &pt->callbacks); | |
1965 | ||
1966 | mutex_unlock(&dm_thin_pool_table.mutex); | |
1967 | ||
1968 | return 0; | |
1969 | ||
1970 | out_free_pt: | |
1971 | kfree(pt); | |
1972 | out: | |
1973 | dm_put_device(ti, data_dev); | |
1974 | out_metadata: | |
1975 | dm_put_device(ti, metadata_dev); | |
1976 | out_unlock: | |
1977 | mutex_unlock(&dm_thin_pool_table.mutex); | |
1978 | ||
1979 | return r; | |
1980 | } | |
1981 | ||
1982 | static int pool_map(struct dm_target *ti, struct bio *bio, | |
1983 | union map_info *map_context) | |
1984 | { | |
1985 | int r; | |
1986 | struct pool_c *pt = ti->private; | |
1987 | struct pool *pool = pt->pool; | |
1988 | unsigned long flags; | |
1989 | ||
1990 | /* | |
1991 | * As this is a singleton target, ti->begin is always zero. | |
1992 | */ | |
1993 | spin_lock_irqsave(&pool->lock, flags); | |
1994 | bio->bi_bdev = pt->data_dev->bdev; | |
1995 | r = DM_MAPIO_REMAPPED; | |
1996 | spin_unlock_irqrestore(&pool->lock, flags); | |
1997 | ||
1998 | return r; | |
1999 | } | |
2000 | ||
2001 | /* | |
2002 | * Retrieves the number of blocks of the data device from | |
2003 | * the superblock and compares it to the actual device size, | |
2004 | * thus resizing the data device in case it has grown. | |
2005 | * | |
2006 | * This both copes with opening preallocated data devices in the ctr | |
2007 | * being followed by a resume | |
2008 | * -and- | |
2009 | * calling the resume method individually after userspace has | |
2010 | * grown the data device in reaction to a table event. | |
2011 | */ | |
2012 | static int pool_preresume(struct dm_target *ti) | |
2013 | { | |
2014 | int r; | |
2015 | struct pool_c *pt = ti->private; | |
2016 | struct pool *pool = pt->pool; | |
2017 | dm_block_t data_size, sb_data_size; | |
2018 | ||
2019 | /* | |
2020 | * Take control of the pool object. | |
2021 | */ | |
2022 | r = bind_control_target(pool, ti); | |
2023 | if (r) | |
2024 | return r; | |
2025 | ||
2026 | data_size = ti->len >> pool->block_shift; | |
2027 | r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size); | |
2028 | if (r) { | |
2029 | DMERR("failed to retrieve data device size"); | |
2030 | return r; | |
2031 | } | |
2032 | ||
2033 | if (data_size < sb_data_size) { | |
2034 | DMERR("pool target too small, is %llu blocks (expected %llu)", | |
2035 | data_size, sb_data_size); | |
2036 | return -EINVAL; | |
2037 | ||
2038 | } else if (data_size > sb_data_size) { | |
2039 | r = dm_pool_resize_data_dev(pool->pmd, data_size); | |
2040 | if (r) { | |
2041 | DMERR("failed to resize data device"); | |
2042 | return r; | |
2043 | } | |
2044 | ||
2045 | r = dm_pool_commit_metadata(pool->pmd); | |
2046 | if (r) { | |
2047 | DMERR("%s: dm_pool_commit_metadata() failed, error = %d", | |
2048 | __func__, r); | |
2049 | return r; | |
2050 | } | |
2051 | } | |
2052 | ||
2053 | return 0; | |
2054 | } | |
2055 | ||
2056 | static void pool_resume(struct dm_target *ti) | |
2057 | { | |
2058 | struct pool_c *pt = ti->private; | |
2059 | struct pool *pool = pt->pool; | |
2060 | unsigned long flags; | |
2061 | ||
2062 | spin_lock_irqsave(&pool->lock, flags); | |
2063 | pool->low_water_triggered = 0; | |
2064 | pool->no_free_space = 0; | |
2065 | __requeue_bios(pool); | |
2066 | spin_unlock_irqrestore(&pool->lock, flags); | |
2067 | ||
905e51b3 | 2068 | do_waker(&pool->waker.work); |
991d9fa0 JT |
2069 | } |
2070 | ||
2071 | static void pool_postsuspend(struct dm_target *ti) | |
2072 | { | |
2073 | int r; | |
2074 | struct pool_c *pt = ti->private; | |
2075 | struct pool *pool = pt->pool; | |
2076 | ||
905e51b3 | 2077 | cancel_delayed_work(&pool->waker); |
991d9fa0 JT |
2078 | flush_workqueue(pool->wq); |
2079 | ||
2080 | r = dm_pool_commit_metadata(pool->pmd); | |
2081 | if (r < 0) { | |
2082 | DMERR("%s: dm_pool_commit_metadata() failed, error = %d", | |
2083 | __func__, r); | |
2084 | /* FIXME: invalidate device? error the next FUA or FLUSH bio ?*/ | |
2085 | } | |
2086 | } | |
2087 | ||
2088 | static int check_arg_count(unsigned argc, unsigned args_required) | |
2089 | { | |
2090 | if (argc != args_required) { | |
2091 | DMWARN("Message received with %u arguments instead of %u.", | |
2092 | argc, args_required); | |
2093 | return -EINVAL; | |
2094 | } | |
2095 | ||
2096 | return 0; | |
2097 | } | |
2098 | ||
2099 | static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning) | |
2100 | { | |
2101 | if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) && | |
2102 | *dev_id <= MAX_DEV_ID) | |
2103 | return 0; | |
2104 | ||
2105 | if (warning) | |
2106 | DMWARN("Message received with invalid device id: %s", arg); | |
2107 | ||
2108 | return -EINVAL; | |
2109 | } | |
2110 | ||
2111 | static int process_create_thin_mesg(unsigned argc, char **argv, struct pool *pool) | |
2112 | { | |
2113 | dm_thin_id dev_id; | |
2114 | int r; | |
2115 | ||
2116 | r = check_arg_count(argc, 2); | |
2117 | if (r) | |
2118 | return r; | |
2119 | ||
2120 | r = read_dev_id(argv[1], &dev_id, 1); | |
2121 | if (r) | |
2122 | return r; | |
2123 | ||
2124 | r = dm_pool_create_thin(pool->pmd, dev_id); | |
2125 | if (r) { | |
2126 | DMWARN("Creation of new thinly-provisioned device with id %s failed.", | |
2127 | argv[1]); | |
2128 | return r; | |
2129 | } | |
2130 | ||
2131 | return 0; | |
2132 | } | |
2133 | ||
2134 | static int process_create_snap_mesg(unsigned argc, char **argv, struct pool *pool) | |
2135 | { | |
2136 | dm_thin_id dev_id; | |
2137 | dm_thin_id origin_dev_id; | |
2138 | int r; | |
2139 | ||
2140 | r = check_arg_count(argc, 3); | |
2141 | if (r) | |
2142 | return r; | |
2143 | ||
2144 | r = read_dev_id(argv[1], &dev_id, 1); | |
2145 | if (r) | |
2146 | return r; | |
2147 | ||
2148 | r = read_dev_id(argv[2], &origin_dev_id, 1); | |
2149 | if (r) | |
2150 | return r; | |
2151 | ||
2152 | r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id); | |
2153 | if (r) { | |
2154 | DMWARN("Creation of new snapshot %s of device %s failed.", | |
2155 | argv[1], argv[2]); | |
2156 | return r; | |
2157 | } | |
2158 | ||
2159 | return 0; | |
2160 | } | |
2161 | ||
2162 | static int process_delete_mesg(unsigned argc, char **argv, struct pool *pool) | |
2163 | { | |
2164 | dm_thin_id dev_id; | |
2165 | int r; | |
2166 | ||
2167 | r = check_arg_count(argc, 2); | |
2168 | if (r) | |
2169 | return r; | |
2170 | ||
2171 | r = read_dev_id(argv[1], &dev_id, 1); | |
2172 | if (r) | |
2173 | return r; | |
2174 | ||
2175 | r = dm_pool_delete_thin_device(pool->pmd, dev_id); | |
2176 | if (r) | |
2177 | DMWARN("Deletion of thin device %s failed.", argv[1]); | |
2178 | ||
2179 | return r; | |
2180 | } | |
2181 | ||
2182 | static int process_set_transaction_id_mesg(unsigned argc, char **argv, struct pool *pool) | |
2183 | { | |
2184 | dm_thin_id old_id, new_id; | |
2185 | int r; | |
2186 | ||
2187 | r = check_arg_count(argc, 3); | |
2188 | if (r) | |
2189 | return r; | |
2190 | ||
2191 | if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) { | |
2192 | DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]); | |
2193 | return -EINVAL; | |
2194 | } | |
2195 | ||
2196 | if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) { | |
2197 | DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]); | |
2198 | return -EINVAL; | |
2199 | } | |
2200 | ||
2201 | r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id); | |
2202 | if (r) { | |
2203 | DMWARN("Failed to change transaction id from %s to %s.", | |
2204 | argv[1], argv[2]); | |
2205 | return r; | |
2206 | } | |
2207 | ||
2208 | return 0; | |
2209 | } | |
2210 | ||
2211 | /* | |
2212 | * Messages supported: | |
2213 | * create_thin <dev_id> | |
2214 | * create_snap <dev_id> <origin_id> | |
2215 | * delete <dev_id> | |
2216 | * trim <dev_id> <new_size_in_sectors> | |
2217 | * set_transaction_id <current_trans_id> <new_trans_id> | |
2218 | */ | |
2219 | static int pool_message(struct dm_target *ti, unsigned argc, char **argv) | |
2220 | { | |
2221 | int r = -EINVAL; | |
2222 | struct pool_c *pt = ti->private; | |
2223 | struct pool *pool = pt->pool; | |
2224 | ||
2225 | if (!strcasecmp(argv[0], "create_thin")) | |
2226 | r = process_create_thin_mesg(argc, argv, pool); | |
2227 | ||
2228 | else if (!strcasecmp(argv[0], "create_snap")) | |
2229 | r = process_create_snap_mesg(argc, argv, pool); | |
2230 | ||
2231 | else if (!strcasecmp(argv[0], "delete")) | |
2232 | r = process_delete_mesg(argc, argv, pool); | |
2233 | ||
2234 | else if (!strcasecmp(argv[0], "set_transaction_id")) | |
2235 | r = process_set_transaction_id_mesg(argc, argv, pool); | |
2236 | ||
2237 | else | |
2238 | DMWARN("Unrecognised thin pool target message received: %s", argv[0]); | |
2239 | ||
2240 | if (!r) { | |
2241 | r = dm_pool_commit_metadata(pool->pmd); | |
2242 | if (r) | |
2243 | DMERR("%s message: dm_pool_commit_metadata() failed, error = %d", | |
2244 | argv[0], r); | |
2245 | } | |
2246 | ||
2247 | return r; | |
2248 | } | |
2249 | ||
2250 | /* | |
2251 | * Status line is: | |
2252 | * <transaction id> <used metadata sectors>/<total metadata sectors> | |
2253 | * <used data sectors>/<total data sectors> <held metadata root> | |
2254 | */ | |
2255 | static int pool_status(struct dm_target *ti, status_type_t type, | |
2256 | char *result, unsigned maxlen) | |
2257 | { | |
2258 | int r; | |
2259 | unsigned sz = 0; | |
2260 | uint64_t transaction_id; | |
2261 | dm_block_t nr_free_blocks_data; | |
2262 | dm_block_t nr_free_blocks_metadata; | |
2263 | dm_block_t nr_blocks_data; | |
2264 | dm_block_t nr_blocks_metadata; | |
2265 | dm_block_t held_root; | |
2266 | char buf[BDEVNAME_SIZE]; | |
2267 | char buf2[BDEVNAME_SIZE]; | |
2268 | struct pool_c *pt = ti->private; | |
2269 | struct pool *pool = pt->pool; | |
2270 | ||
2271 | switch (type) { | |
2272 | case STATUSTYPE_INFO: | |
2273 | r = dm_pool_get_metadata_transaction_id(pool->pmd, | |
2274 | &transaction_id); | |
2275 | if (r) | |
2276 | return r; | |
2277 | ||
2278 | r = dm_pool_get_free_metadata_block_count(pool->pmd, | |
2279 | &nr_free_blocks_metadata); | |
2280 | if (r) | |
2281 | return r; | |
2282 | ||
2283 | r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata); | |
2284 | if (r) | |
2285 | return r; | |
2286 | ||
2287 | r = dm_pool_get_free_block_count(pool->pmd, | |
2288 | &nr_free_blocks_data); | |
2289 | if (r) | |
2290 | return r; | |
2291 | ||
2292 | r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data); | |
2293 | if (r) | |
2294 | return r; | |
2295 | ||
2296 | r = dm_pool_get_held_metadata_root(pool->pmd, &held_root); | |
2297 | if (r) | |
2298 | return r; | |
2299 | ||
2300 | DMEMIT("%llu %llu/%llu %llu/%llu ", | |
2301 | (unsigned long long)transaction_id, | |
2302 | (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), | |
2303 | (unsigned long long)nr_blocks_metadata, | |
2304 | (unsigned long long)(nr_blocks_data - nr_free_blocks_data), | |
2305 | (unsigned long long)nr_blocks_data); | |
2306 | ||
2307 | if (held_root) | |
2308 | DMEMIT("%llu", held_root); | |
2309 | else | |
2310 | DMEMIT("-"); | |
2311 | ||
2312 | break; | |
2313 | ||
2314 | case STATUSTYPE_TABLE: | |
2315 | DMEMIT("%s %s %lu %llu ", | |
2316 | format_dev_t(buf, pt->metadata_dev->bdev->bd_dev), | |
2317 | format_dev_t(buf2, pt->data_dev->bdev->bd_dev), | |
2318 | (unsigned long)pool->sectors_per_block, | |
2319 | (unsigned long long)pt->low_water_blocks); | |
2320 | ||
2321 | DMEMIT("%u ", !pool->zero_new_blocks); | |
2322 | ||
2323 | if (!pool->zero_new_blocks) | |
2324 | DMEMIT("skip_block_zeroing "); | |
2325 | break; | |
2326 | } | |
2327 | ||
2328 | return 0; | |
2329 | } | |
2330 | ||
2331 | static int pool_iterate_devices(struct dm_target *ti, | |
2332 | iterate_devices_callout_fn fn, void *data) | |
2333 | { | |
2334 | struct pool_c *pt = ti->private; | |
2335 | ||
2336 | return fn(ti, pt->data_dev, 0, ti->len, data); | |
2337 | } | |
2338 | ||
2339 | static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm, | |
2340 | struct bio_vec *biovec, int max_size) | |
2341 | { | |
2342 | struct pool_c *pt = ti->private; | |
2343 | struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); | |
2344 | ||
2345 | if (!q->merge_bvec_fn) | |
2346 | return max_size; | |
2347 | ||
2348 | bvm->bi_bdev = pt->data_dev->bdev; | |
2349 | ||
2350 | return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); | |
2351 | } | |
2352 | ||
104655fd JT |
2353 | static void set_discard_limits(struct pool *pool, struct queue_limits *limits) |
2354 | { | |
2355 | limits->max_discard_sectors = pool->sectors_per_block; | |
2356 | ||
2357 | /* | |
2358 | * This is just a hint, and not enforced. We have to cope with | |
2359 | * bios that overlap 2 blocks. | |
2360 | */ | |
2361 | limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT; | |
2362 | } | |
2363 | ||
991d9fa0 JT |
2364 | static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits) |
2365 | { | |
2366 | struct pool_c *pt = ti->private; | |
2367 | struct pool *pool = pt->pool; | |
2368 | ||
2369 | blk_limits_io_min(limits, 0); | |
2370 | blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT); | |
104655fd | 2371 | set_discard_limits(pool, limits); |
991d9fa0 JT |
2372 | } |
2373 | ||
2374 | static struct target_type pool_target = { | |
2375 | .name = "thin-pool", | |
2376 | .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE | | |
2377 | DM_TARGET_IMMUTABLE, | |
2378 | .version = {1, 0, 0}, | |
2379 | .module = THIS_MODULE, | |
2380 | .ctr = pool_ctr, | |
2381 | .dtr = pool_dtr, | |
2382 | .map = pool_map, | |
2383 | .postsuspend = pool_postsuspend, | |
2384 | .preresume = pool_preresume, | |
2385 | .resume = pool_resume, | |
2386 | .message = pool_message, | |
2387 | .status = pool_status, | |
2388 | .merge = pool_merge, | |
2389 | .iterate_devices = pool_iterate_devices, | |
2390 | .io_hints = pool_io_hints, | |
2391 | }; | |
2392 | ||
2393 | /*---------------------------------------------------------------- | |
2394 | * Thin target methods | |
2395 | *--------------------------------------------------------------*/ | |
2396 | static void thin_dtr(struct dm_target *ti) | |
2397 | { | |
2398 | struct thin_c *tc = ti->private; | |
2399 | ||
2400 | mutex_lock(&dm_thin_pool_table.mutex); | |
2401 | ||
2402 | __pool_dec(tc->pool); | |
2403 | dm_pool_close_thin_device(tc->td); | |
2404 | dm_put_device(ti, tc->pool_dev); | |
2dd9c257 JT |
2405 | if (tc->origin_dev) |
2406 | dm_put_device(ti, tc->origin_dev); | |
991d9fa0 JT |
2407 | kfree(tc); |
2408 | ||
2409 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2410 | } | |
2411 | ||
2412 | /* | |
2413 | * Thin target parameters: | |
2414 | * | |
2dd9c257 | 2415 | * <pool_dev> <dev_id> [origin_dev] |
991d9fa0 JT |
2416 | * |
2417 | * pool_dev: the path to the pool (eg, /dev/mapper/my_pool) | |
2418 | * dev_id: the internal device identifier | |
2dd9c257 | 2419 | * origin_dev: a device external to the pool that should act as the origin |
991d9fa0 JT |
2420 | */ |
2421 | static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
2422 | { | |
2423 | int r; | |
2424 | struct thin_c *tc; | |
2dd9c257 | 2425 | struct dm_dev *pool_dev, *origin_dev; |
991d9fa0 JT |
2426 | struct mapped_device *pool_md; |
2427 | ||
2428 | mutex_lock(&dm_thin_pool_table.mutex); | |
2429 | ||
2dd9c257 | 2430 | if (argc != 2 && argc != 3) { |
991d9fa0 JT |
2431 | ti->error = "Invalid argument count"; |
2432 | r = -EINVAL; | |
2433 | goto out_unlock; | |
2434 | } | |
2435 | ||
2436 | tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL); | |
2437 | if (!tc) { | |
2438 | ti->error = "Out of memory"; | |
2439 | r = -ENOMEM; | |
2440 | goto out_unlock; | |
2441 | } | |
2442 | ||
2dd9c257 JT |
2443 | if (argc == 3) { |
2444 | r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev); | |
2445 | if (r) { | |
2446 | ti->error = "Error opening origin device"; | |
2447 | goto bad_origin_dev; | |
2448 | } | |
2449 | tc->origin_dev = origin_dev; | |
2450 | } | |
2451 | ||
991d9fa0 JT |
2452 | r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev); |
2453 | if (r) { | |
2454 | ti->error = "Error opening pool device"; | |
2455 | goto bad_pool_dev; | |
2456 | } | |
2457 | tc->pool_dev = pool_dev; | |
2458 | ||
2459 | if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) { | |
2460 | ti->error = "Invalid device id"; | |
2461 | r = -EINVAL; | |
2462 | goto bad_common; | |
2463 | } | |
2464 | ||
2465 | pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev); | |
2466 | if (!pool_md) { | |
2467 | ti->error = "Couldn't get pool mapped device"; | |
2468 | r = -EINVAL; | |
2469 | goto bad_common; | |
2470 | } | |
2471 | ||
2472 | tc->pool = __pool_table_lookup(pool_md); | |
2473 | if (!tc->pool) { | |
2474 | ti->error = "Couldn't find pool object"; | |
2475 | r = -EINVAL; | |
2476 | goto bad_pool_lookup; | |
2477 | } | |
2478 | __pool_inc(tc->pool); | |
2479 | ||
2480 | r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td); | |
2481 | if (r) { | |
2482 | ti->error = "Couldn't open thin internal device"; | |
2483 | goto bad_thin_open; | |
2484 | } | |
2485 | ||
2486 | ti->split_io = tc->pool->sectors_per_block; | |
2487 | ti->num_flush_requests = 1; | |
104655fd JT |
2488 | ti->num_discard_requests = 1; |
2489 | ti->discards_supported = 1; | |
991d9fa0 JT |
2490 | |
2491 | dm_put(pool_md); | |
2492 | ||
2493 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2494 | ||
2495 | return 0; | |
2496 | ||
2497 | bad_thin_open: | |
2498 | __pool_dec(tc->pool); | |
2499 | bad_pool_lookup: | |
2500 | dm_put(pool_md); | |
2501 | bad_common: | |
2502 | dm_put_device(ti, tc->pool_dev); | |
2503 | bad_pool_dev: | |
2dd9c257 JT |
2504 | if (tc->origin_dev) |
2505 | dm_put_device(ti, tc->origin_dev); | |
2506 | bad_origin_dev: | |
991d9fa0 JT |
2507 | kfree(tc); |
2508 | out_unlock: | |
2509 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2510 | ||
2511 | return r; | |
2512 | } | |
2513 | ||
2514 | static int thin_map(struct dm_target *ti, struct bio *bio, | |
2515 | union map_info *map_context) | |
2516 | { | |
6efd6e83 | 2517 | bio->bi_sector = dm_target_offset(ti, bio->bi_sector); |
991d9fa0 JT |
2518 | |
2519 | return thin_bio_map(ti, bio, map_context); | |
2520 | } | |
2521 | ||
eb2aa48d JT |
2522 | static int thin_endio(struct dm_target *ti, |
2523 | struct bio *bio, int err, | |
2524 | union map_info *map_context) | |
2525 | { | |
2526 | unsigned long flags; | |
2527 | struct endio_hook *h = map_context->ptr; | |
2528 | struct list_head work; | |
2529 | struct new_mapping *m, *tmp; | |
2530 | struct pool *pool = h->tc->pool; | |
2531 | ||
2532 | if (h->shared_read_entry) { | |
2533 | INIT_LIST_HEAD(&work); | |
2534 | ds_dec(h->shared_read_entry, &work); | |
2535 | ||
2536 | spin_lock_irqsave(&pool->lock, flags); | |
2537 | list_for_each_entry_safe(m, tmp, &work, list) { | |
2538 | list_del(&m->list); | |
2539 | m->quiesced = 1; | |
2540 | __maybe_add_mapping(m); | |
2541 | } | |
2542 | spin_unlock_irqrestore(&pool->lock, flags); | |
2543 | } | |
2544 | ||
104655fd JT |
2545 | if (h->all_io_entry) { |
2546 | INIT_LIST_HEAD(&work); | |
2547 | ds_dec(h->all_io_entry, &work); | |
2548 | list_for_each_entry_safe(m, tmp, &work, list) | |
2549 | list_add(&m->list, &pool->prepared_discards); | |
2550 | } | |
2551 | ||
eb2aa48d JT |
2552 | mempool_free(h, pool->endio_hook_pool); |
2553 | ||
2554 | return 0; | |
2555 | } | |
2556 | ||
991d9fa0 JT |
2557 | static void thin_postsuspend(struct dm_target *ti) |
2558 | { | |
2559 | if (dm_noflush_suspending(ti)) | |
2560 | requeue_io((struct thin_c *)ti->private); | |
2561 | } | |
2562 | ||
2563 | /* | |
2564 | * <nr mapped sectors> <highest mapped sector> | |
2565 | */ | |
2566 | static int thin_status(struct dm_target *ti, status_type_t type, | |
2567 | char *result, unsigned maxlen) | |
2568 | { | |
2569 | int r; | |
2570 | ssize_t sz = 0; | |
2571 | dm_block_t mapped, highest; | |
2572 | char buf[BDEVNAME_SIZE]; | |
2573 | struct thin_c *tc = ti->private; | |
2574 | ||
2575 | if (!tc->td) | |
2576 | DMEMIT("-"); | |
2577 | else { | |
2578 | switch (type) { | |
2579 | case STATUSTYPE_INFO: | |
2580 | r = dm_thin_get_mapped_count(tc->td, &mapped); | |
2581 | if (r) | |
2582 | return r; | |
2583 | ||
2584 | r = dm_thin_get_highest_mapped_block(tc->td, &highest); | |
2585 | if (r < 0) | |
2586 | return r; | |
2587 | ||
2588 | DMEMIT("%llu ", mapped * tc->pool->sectors_per_block); | |
2589 | if (r) | |
2590 | DMEMIT("%llu", ((highest + 1) * | |
2591 | tc->pool->sectors_per_block) - 1); | |
2592 | else | |
2593 | DMEMIT("-"); | |
2594 | break; | |
2595 | ||
2596 | case STATUSTYPE_TABLE: | |
2597 | DMEMIT("%s %lu", | |
2598 | format_dev_t(buf, tc->pool_dev->bdev->bd_dev), | |
2599 | (unsigned long) tc->dev_id); | |
2dd9c257 JT |
2600 | if (tc->origin_dev) |
2601 | DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev)); | |
991d9fa0 JT |
2602 | break; |
2603 | } | |
2604 | } | |
2605 | ||
2606 | return 0; | |
2607 | } | |
2608 | ||
2609 | static int thin_iterate_devices(struct dm_target *ti, | |
2610 | iterate_devices_callout_fn fn, void *data) | |
2611 | { | |
2612 | dm_block_t blocks; | |
2613 | struct thin_c *tc = ti->private; | |
2614 | ||
2615 | /* | |
2616 | * We can't call dm_pool_get_data_dev_size() since that blocks. So | |
2617 | * we follow a more convoluted path through to the pool's target. | |
2618 | */ | |
2619 | if (!tc->pool->ti) | |
2620 | return 0; /* nothing is bound */ | |
2621 | ||
2622 | blocks = tc->pool->ti->len >> tc->pool->block_shift; | |
2623 | if (blocks) | |
2624 | return fn(ti, tc->pool_dev, 0, tc->pool->sectors_per_block * blocks, data); | |
2625 | ||
2626 | return 0; | |
2627 | } | |
2628 | ||
2629 | static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
2630 | { | |
2631 | struct thin_c *tc = ti->private; | |
104655fd | 2632 | struct pool *pool = tc->pool; |
991d9fa0 JT |
2633 | |
2634 | blk_limits_io_min(limits, 0); | |
104655fd JT |
2635 | blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT); |
2636 | set_discard_limits(pool, limits); | |
991d9fa0 JT |
2637 | } |
2638 | ||
2639 | static struct target_type thin_target = { | |
2640 | .name = "thin", | |
2dd9c257 | 2641 | .version = {1, 1, 0}, |
991d9fa0 JT |
2642 | .module = THIS_MODULE, |
2643 | .ctr = thin_ctr, | |
2644 | .dtr = thin_dtr, | |
2645 | .map = thin_map, | |
eb2aa48d | 2646 | .end_io = thin_endio, |
991d9fa0 JT |
2647 | .postsuspend = thin_postsuspend, |
2648 | .status = thin_status, | |
2649 | .iterate_devices = thin_iterate_devices, | |
2650 | .io_hints = thin_io_hints, | |
2651 | }; | |
2652 | ||
2653 | /*----------------------------------------------------------------*/ | |
2654 | ||
2655 | static int __init dm_thin_init(void) | |
2656 | { | |
2657 | int r; | |
2658 | ||
2659 | pool_table_init(); | |
2660 | ||
2661 | r = dm_register_target(&thin_target); | |
2662 | if (r) | |
2663 | return r; | |
2664 | ||
2665 | r = dm_register_target(&pool_target); | |
2666 | if (r) | |
2667 | dm_unregister_target(&thin_target); | |
2668 | ||
2669 | return r; | |
2670 | } | |
2671 | ||
2672 | static void dm_thin_exit(void) | |
2673 | { | |
2674 | dm_unregister_target(&thin_target); | |
2675 | dm_unregister_target(&pool_target); | |
2676 | } | |
2677 | ||
2678 | module_init(dm_thin_init); | |
2679 | module_exit(dm_thin_exit); | |
2680 | ||
2681 | MODULE_DESCRIPTION(DM_NAME "device-mapper thin provisioning target"); | |
2682 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
2683 | MODULE_LICENSE("GPL"); |