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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; | |
67e2e2b2 JT |
492 | |
493 | struct pool_features { | |
494 | unsigned zero_new_blocks:1; | |
495 | unsigned discard_enabled:1; | |
496 | unsigned discard_passdown:1; | |
497 | }; | |
498 | ||
991d9fa0 JT |
499 | struct pool { |
500 | struct list_head list; | |
501 | struct dm_target *ti; /* Only set if a pool target is bound */ | |
502 | ||
503 | struct mapped_device *pool_md; | |
504 | struct block_device *md_dev; | |
505 | struct dm_pool_metadata *pmd; | |
506 | ||
507 | uint32_t sectors_per_block; | |
508 | unsigned block_shift; | |
509 | dm_block_t offset_mask; | |
510 | dm_block_t low_water_blocks; | |
511 | ||
67e2e2b2 | 512 | struct pool_features pf; |
991d9fa0 JT |
513 | unsigned low_water_triggered:1; /* A dm event has been sent */ |
514 | unsigned no_free_space:1; /* A -ENOSPC warning has been issued */ | |
515 | ||
516 | struct bio_prison *prison; | |
517 | struct dm_kcopyd_client *copier; | |
518 | ||
519 | struct workqueue_struct *wq; | |
520 | struct work_struct worker; | |
905e51b3 | 521 | struct delayed_work waker; |
991d9fa0 JT |
522 | |
523 | unsigned ref_count; | |
905e51b3 | 524 | unsigned long last_commit_jiffies; |
991d9fa0 JT |
525 | |
526 | spinlock_t lock; | |
527 | struct bio_list deferred_bios; | |
528 | struct bio_list deferred_flush_bios; | |
529 | struct list_head prepared_mappings; | |
104655fd | 530 | struct list_head prepared_discards; |
991d9fa0 JT |
531 | |
532 | struct bio_list retry_on_resume_list; | |
533 | ||
eb2aa48d | 534 | struct deferred_set shared_read_ds; |
104655fd | 535 | struct deferred_set all_io_ds; |
991d9fa0 JT |
536 | |
537 | struct new_mapping *next_mapping; | |
538 | mempool_t *mapping_pool; | |
539 | mempool_t *endio_hook_pool; | |
540 | }; | |
541 | ||
542 | /* | |
543 | * Target context for a pool. | |
544 | */ | |
545 | struct pool_c { | |
546 | struct dm_target *ti; | |
547 | struct pool *pool; | |
548 | struct dm_dev *data_dev; | |
549 | struct dm_dev *metadata_dev; | |
550 | struct dm_target_callbacks callbacks; | |
551 | ||
552 | dm_block_t low_water_blocks; | |
67e2e2b2 | 553 | struct pool_features pf; |
991d9fa0 JT |
554 | }; |
555 | ||
556 | /* | |
557 | * Target context for a thin. | |
558 | */ | |
559 | struct thin_c { | |
560 | struct dm_dev *pool_dev; | |
2dd9c257 | 561 | struct dm_dev *origin_dev; |
991d9fa0 JT |
562 | dm_thin_id dev_id; |
563 | ||
564 | struct pool *pool; | |
565 | struct dm_thin_device *td; | |
566 | }; | |
567 | ||
568 | /*----------------------------------------------------------------*/ | |
569 | ||
570 | /* | |
571 | * A global list of pools that uses a struct mapped_device as a key. | |
572 | */ | |
573 | static struct dm_thin_pool_table { | |
574 | struct mutex mutex; | |
575 | struct list_head pools; | |
576 | } dm_thin_pool_table; | |
577 | ||
578 | static void pool_table_init(void) | |
579 | { | |
580 | mutex_init(&dm_thin_pool_table.mutex); | |
581 | INIT_LIST_HEAD(&dm_thin_pool_table.pools); | |
582 | } | |
583 | ||
584 | static void __pool_table_insert(struct pool *pool) | |
585 | { | |
586 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
587 | list_add(&pool->list, &dm_thin_pool_table.pools); | |
588 | } | |
589 | ||
590 | static void __pool_table_remove(struct pool *pool) | |
591 | { | |
592 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
593 | list_del(&pool->list); | |
594 | } | |
595 | ||
596 | static struct pool *__pool_table_lookup(struct mapped_device *md) | |
597 | { | |
598 | struct pool *pool = NULL, *tmp; | |
599 | ||
600 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
601 | ||
602 | list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) { | |
603 | if (tmp->pool_md == md) { | |
604 | pool = tmp; | |
605 | break; | |
606 | } | |
607 | } | |
608 | ||
609 | return pool; | |
610 | } | |
611 | ||
612 | static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev) | |
613 | { | |
614 | struct pool *pool = NULL, *tmp; | |
615 | ||
616 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
617 | ||
618 | list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) { | |
619 | if (tmp->md_dev == md_dev) { | |
620 | pool = tmp; | |
621 | break; | |
622 | } | |
623 | } | |
624 | ||
625 | return pool; | |
626 | } | |
627 | ||
628 | /*----------------------------------------------------------------*/ | |
629 | ||
eb2aa48d JT |
630 | struct endio_hook { |
631 | struct thin_c *tc; | |
632 | struct deferred_entry *shared_read_entry; | |
104655fd | 633 | struct deferred_entry *all_io_entry; |
eb2aa48d JT |
634 | struct new_mapping *overwrite_mapping; |
635 | }; | |
636 | ||
991d9fa0 JT |
637 | static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master) |
638 | { | |
639 | struct bio *bio; | |
640 | struct bio_list bios; | |
641 | ||
642 | bio_list_init(&bios); | |
643 | bio_list_merge(&bios, master); | |
644 | bio_list_init(master); | |
645 | ||
646 | while ((bio = bio_list_pop(&bios))) { | |
eb2aa48d JT |
647 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
648 | if (h->tc == tc) | |
991d9fa0 JT |
649 | bio_endio(bio, DM_ENDIO_REQUEUE); |
650 | else | |
651 | bio_list_add(master, bio); | |
652 | } | |
653 | } | |
654 | ||
655 | static void requeue_io(struct thin_c *tc) | |
656 | { | |
657 | struct pool *pool = tc->pool; | |
658 | unsigned long flags; | |
659 | ||
660 | spin_lock_irqsave(&pool->lock, flags); | |
661 | __requeue_bio_list(tc, &pool->deferred_bios); | |
662 | __requeue_bio_list(tc, &pool->retry_on_resume_list); | |
663 | spin_unlock_irqrestore(&pool->lock, flags); | |
664 | } | |
665 | ||
666 | /* | |
667 | * This section of code contains the logic for processing a thin device's IO. | |
668 | * Much of the code depends on pool object resources (lists, workqueues, etc) | |
669 | * but most is exclusively called from the thin target rather than the thin-pool | |
670 | * target. | |
671 | */ | |
672 | ||
673 | static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio) | |
674 | { | |
675 | return bio->bi_sector >> tc->pool->block_shift; | |
676 | } | |
677 | ||
678 | static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block) | |
679 | { | |
680 | struct pool *pool = tc->pool; | |
681 | ||
682 | bio->bi_bdev = tc->pool_dev->bdev; | |
683 | bio->bi_sector = (block << pool->block_shift) + | |
684 | (bio->bi_sector & pool->offset_mask); | |
685 | } | |
686 | ||
2dd9c257 JT |
687 | static void remap_to_origin(struct thin_c *tc, struct bio *bio) |
688 | { | |
689 | bio->bi_bdev = tc->origin_dev->bdev; | |
690 | } | |
691 | ||
692 | static void issue(struct thin_c *tc, struct bio *bio) | |
991d9fa0 JT |
693 | { |
694 | struct pool *pool = tc->pool; | |
695 | unsigned long flags; | |
696 | ||
991d9fa0 JT |
697 | /* |
698 | * Batch together any FUA/FLUSH bios we find and then issue | |
699 | * a single commit for them in process_deferred_bios(). | |
700 | */ | |
701 | if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) { | |
702 | spin_lock_irqsave(&pool->lock, flags); | |
703 | bio_list_add(&pool->deferred_flush_bios, bio); | |
704 | spin_unlock_irqrestore(&pool->lock, flags); | |
705 | } else | |
706 | generic_make_request(bio); | |
707 | } | |
708 | ||
2dd9c257 JT |
709 | static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio) |
710 | { | |
711 | remap_to_origin(tc, bio); | |
712 | issue(tc, bio); | |
713 | } | |
714 | ||
715 | static void remap_and_issue(struct thin_c *tc, struct bio *bio, | |
716 | dm_block_t block) | |
717 | { | |
718 | remap(tc, bio, block); | |
719 | issue(tc, bio); | |
720 | } | |
721 | ||
991d9fa0 JT |
722 | /* |
723 | * wake_worker() is used when new work is queued and when pool_resume is | |
724 | * ready to continue deferred IO processing. | |
725 | */ | |
726 | static void wake_worker(struct pool *pool) | |
727 | { | |
728 | queue_work(pool->wq, &pool->worker); | |
729 | } | |
730 | ||
731 | /*----------------------------------------------------------------*/ | |
732 | ||
733 | /* | |
734 | * Bio endio functions. | |
735 | */ | |
991d9fa0 JT |
736 | struct new_mapping { |
737 | struct list_head list; | |
738 | ||
eb2aa48d JT |
739 | unsigned quiesced:1; |
740 | unsigned prepared:1; | |
104655fd | 741 | unsigned pass_discard:1; |
991d9fa0 JT |
742 | |
743 | struct thin_c *tc; | |
744 | dm_block_t virt_block; | |
745 | dm_block_t data_block; | |
104655fd | 746 | struct cell *cell, *cell2; |
991d9fa0 JT |
747 | int err; |
748 | ||
749 | /* | |
750 | * If the bio covers the whole area of a block then we can avoid | |
751 | * zeroing or copying. Instead this bio is hooked. The bio will | |
752 | * still be in the cell, so care has to be taken to avoid issuing | |
753 | * the bio twice. | |
754 | */ | |
755 | struct bio *bio; | |
756 | bio_end_io_t *saved_bi_end_io; | |
757 | }; | |
758 | ||
759 | static void __maybe_add_mapping(struct new_mapping *m) | |
760 | { | |
761 | struct pool *pool = m->tc->pool; | |
762 | ||
eb2aa48d | 763 | if (m->quiesced && m->prepared) { |
991d9fa0 JT |
764 | list_add(&m->list, &pool->prepared_mappings); |
765 | wake_worker(pool); | |
766 | } | |
767 | } | |
768 | ||
769 | static void copy_complete(int read_err, unsigned long write_err, void *context) | |
770 | { | |
771 | unsigned long flags; | |
772 | struct new_mapping *m = context; | |
773 | struct pool *pool = m->tc->pool; | |
774 | ||
775 | m->err = read_err || write_err ? -EIO : 0; | |
776 | ||
777 | spin_lock_irqsave(&pool->lock, flags); | |
778 | m->prepared = 1; | |
779 | __maybe_add_mapping(m); | |
780 | spin_unlock_irqrestore(&pool->lock, flags); | |
781 | } | |
782 | ||
783 | static void overwrite_endio(struct bio *bio, int err) | |
784 | { | |
785 | unsigned long flags; | |
eb2aa48d JT |
786 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
787 | struct new_mapping *m = h->overwrite_mapping; | |
991d9fa0 JT |
788 | struct pool *pool = m->tc->pool; |
789 | ||
790 | m->err = err; | |
791 | ||
792 | spin_lock_irqsave(&pool->lock, flags); | |
793 | m->prepared = 1; | |
794 | __maybe_add_mapping(m); | |
795 | spin_unlock_irqrestore(&pool->lock, flags); | |
796 | } | |
797 | ||
991d9fa0 JT |
798 | /*----------------------------------------------------------------*/ |
799 | ||
800 | /* | |
801 | * Workqueue. | |
802 | */ | |
803 | ||
804 | /* | |
805 | * Prepared mapping jobs. | |
806 | */ | |
807 | ||
808 | /* | |
809 | * This sends the bios in the cell back to the deferred_bios list. | |
810 | */ | |
811 | static void cell_defer(struct thin_c *tc, struct cell *cell, | |
812 | dm_block_t data_block) | |
813 | { | |
814 | struct pool *pool = tc->pool; | |
815 | unsigned long flags; | |
816 | ||
817 | spin_lock_irqsave(&pool->lock, flags); | |
818 | cell_release(cell, &pool->deferred_bios); | |
819 | spin_unlock_irqrestore(&tc->pool->lock, flags); | |
820 | ||
821 | wake_worker(pool); | |
822 | } | |
823 | ||
824 | /* | |
825 | * Same as cell_defer above, except it omits one particular detainee, | |
826 | * a write bio that covers the block and has already been processed. | |
827 | */ | |
6f94a4c4 | 828 | static void cell_defer_except(struct thin_c *tc, struct cell *cell) |
991d9fa0 JT |
829 | { |
830 | struct bio_list bios; | |
991d9fa0 JT |
831 | struct pool *pool = tc->pool; |
832 | unsigned long flags; | |
833 | ||
834 | bio_list_init(&bios); | |
991d9fa0 JT |
835 | |
836 | spin_lock_irqsave(&pool->lock, flags); | |
6f94a4c4 | 837 | cell_release_no_holder(cell, &pool->deferred_bios); |
991d9fa0 JT |
838 | spin_unlock_irqrestore(&pool->lock, flags); |
839 | ||
840 | wake_worker(pool); | |
841 | } | |
842 | ||
843 | static void process_prepared_mapping(struct new_mapping *m) | |
844 | { | |
845 | struct thin_c *tc = m->tc; | |
846 | struct bio *bio; | |
847 | int r; | |
848 | ||
849 | bio = m->bio; | |
850 | if (bio) | |
851 | bio->bi_end_io = m->saved_bi_end_io; | |
852 | ||
853 | if (m->err) { | |
854 | cell_error(m->cell); | |
855 | return; | |
856 | } | |
857 | ||
858 | /* | |
859 | * Commit the prepared block into the mapping btree. | |
860 | * Any I/O for this block arriving after this point will get | |
861 | * remapped to it directly. | |
862 | */ | |
863 | r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block); | |
864 | if (r) { | |
865 | DMERR("dm_thin_insert_block() failed"); | |
866 | cell_error(m->cell); | |
867 | return; | |
868 | } | |
869 | ||
870 | /* | |
871 | * Release any bios held while the block was being provisioned. | |
872 | * If we are processing a write bio that completely covers the block, | |
873 | * we already processed it so can ignore it now when processing | |
874 | * the bios in the cell. | |
875 | */ | |
876 | if (bio) { | |
6f94a4c4 | 877 | cell_defer_except(tc, m->cell); |
991d9fa0 JT |
878 | bio_endio(bio, 0); |
879 | } else | |
880 | cell_defer(tc, m->cell, m->data_block); | |
881 | ||
882 | list_del(&m->list); | |
883 | mempool_free(m, tc->pool->mapping_pool); | |
884 | } | |
885 | ||
104655fd JT |
886 | static void process_prepared_discard(struct new_mapping *m) |
887 | { | |
888 | int r; | |
889 | struct thin_c *tc = m->tc; | |
890 | ||
891 | r = dm_thin_remove_block(tc->td, m->virt_block); | |
892 | if (r) | |
893 | DMERR("dm_thin_remove_block() failed"); | |
894 | ||
895 | /* | |
896 | * Pass the discard down to the underlying device? | |
897 | */ | |
898 | if (m->pass_discard) | |
899 | remap_and_issue(tc, m->bio, m->data_block); | |
900 | else | |
901 | bio_endio(m->bio, 0); | |
902 | ||
903 | cell_defer_except(tc, m->cell); | |
904 | cell_defer_except(tc, m->cell2); | |
905 | mempool_free(m, tc->pool->mapping_pool); | |
906 | } | |
907 | ||
908 | static void process_prepared(struct pool *pool, struct list_head *head, | |
909 | void (*fn)(struct new_mapping *)) | |
991d9fa0 JT |
910 | { |
911 | unsigned long flags; | |
912 | struct list_head maps; | |
913 | struct new_mapping *m, *tmp; | |
914 | ||
915 | INIT_LIST_HEAD(&maps); | |
916 | spin_lock_irqsave(&pool->lock, flags); | |
104655fd | 917 | list_splice_init(head, &maps); |
991d9fa0 JT |
918 | spin_unlock_irqrestore(&pool->lock, flags); |
919 | ||
920 | list_for_each_entry_safe(m, tmp, &maps, list) | |
104655fd | 921 | fn(m); |
991d9fa0 JT |
922 | } |
923 | ||
924 | /* | |
925 | * Deferred bio jobs. | |
926 | */ | |
104655fd | 927 | static int io_overlaps_block(struct pool *pool, struct bio *bio) |
991d9fa0 | 928 | { |
104655fd | 929 | return !(bio->bi_sector & pool->offset_mask) && |
991d9fa0 | 930 | (bio->bi_size == (pool->sectors_per_block << SECTOR_SHIFT)); |
104655fd JT |
931 | |
932 | } | |
933 | ||
934 | static int io_overwrites_block(struct pool *pool, struct bio *bio) | |
935 | { | |
936 | return (bio_data_dir(bio) == WRITE) && | |
937 | io_overlaps_block(pool, bio); | |
991d9fa0 JT |
938 | } |
939 | ||
940 | static void save_and_set_endio(struct bio *bio, bio_end_io_t **save, | |
941 | bio_end_io_t *fn) | |
942 | { | |
943 | *save = bio->bi_end_io; | |
944 | bio->bi_end_io = fn; | |
945 | } | |
946 | ||
947 | static int ensure_next_mapping(struct pool *pool) | |
948 | { | |
949 | if (pool->next_mapping) | |
950 | return 0; | |
951 | ||
952 | pool->next_mapping = mempool_alloc(pool->mapping_pool, GFP_ATOMIC); | |
953 | ||
954 | return pool->next_mapping ? 0 : -ENOMEM; | |
955 | } | |
956 | ||
957 | static struct new_mapping *get_next_mapping(struct pool *pool) | |
958 | { | |
959 | struct new_mapping *r = pool->next_mapping; | |
960 | ||
961 | BUG_ON(!pool->next_mapping); | |
962 | ||
963 | pool->next_mapping = NULL; | |
964 | ||
965 | return r; | |
966 | } | |
967 | ||
968 | static void schedule_copy(struct thin_c *tc, dm_block_t virt_block, | |
2dd9c257 JT |
969 | struct dm_dev *origin, dm_block_t data_origin, |
970 | dm_block_t data_dest, | |
991d9fa0 JT |
971 | struct cell *cell, struct bio *bio) |
972 | { | |
973 | int r; | |
974 | struct pool *pool = tc->pool; | |
975 | struct new_mapping *m = get_next_mapping(pool); | |
976 | ||
977 | INIT_LIST_HEAD(&m->list); | |
eb2aa48d | 978 | m->quiesced = 0; |
991d9fa0 JT |
979 | m->prepared = 0; |
980 | m->tc = tc; | |
981 | m->virt_block = virt_block; | |
982 | m->data_block = data_dest; | |
983 | m->cell = cell; | |
984 | m->err = 0; | |
985 | m->bio = NULL; | |
986 | ||
eb2aa48d JT |
987 | if (!ds_add_work(&pool->shared_read_ds, &m->list)) |
988 | m->quiesced = 1; | |
991d9fa0 JT |
989 | |
990 | /* | |
991 | * IO to pool_dev remaps to the pool target's data_dev. | |
992 | * | |
993 | * If the whole block of data is being overwritten, we can issue the | |
994 | * bio immediately. Otherwise we use kcopyd to clone the data first. | |
995 | */ | |
996 | if (io_overwrites_block(pool, bio)) { | |
eb2aa48d JT |
997 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
998 | h->overwrite_mapping = m; | |
991d9fa0 JT |
999 | m->bio = bio; |
1000 | save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio); | |
991d9fa0 JT |
1001 | remap_and_issue(tc, bio, data_dest); |
1002 | } else { | |
1003 | struct dm_io_region from, to; | |
1004 | ||
2dd9c257 | 1005 | from.bdev = origin->bdev; |
991d9fa0 JT |
1006 | from.sector = data_origin * pool->sectors_per_block; |
1007 | from.count = pool->sectors_per_block; | |
1008 | ||
1009 | to.bdev = tc->pool_dev->bdev; | |
1010 | to.sector = data_dest * pool->sectors_per_block; | |
1011 | to.count = pool->sectors_per_block; | |
1012 | ||
1013 | r = dm_kcopyd_copy(pool->copier, &from, 1, &to, | |
1014 | 0, copy_complete, m); | |
1015 | if (r < 0) { | |
1016 | mempool_free(m, pool->mapping_pool); | |
1017 | DMERR("dm_kcopyd_copy() failed"); | |
1018 | cell_error(cell); | |
1019 | } | |
1020 | } | |
1021 | } | |
1022 | ||
2dd9c257 JT |
1023 | static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block, |
1024 | dm_block_t data_origin, dm_block_t data_dest, | |
1025 | struct cell *cell, struct bio *bio) | |
1026 | { | |
1027 | schedule_copy(tc, virt_block, tc->pool_dev, | |
1028 | data_origin, data_dest, cell, bio); | |
1029 | } | |
1030 | ||
1031 | static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block, | |
1032 | dm_block_t data_dest, | |
1033 | struct cell *cell, struct bio *bio) | |
1034 | { | |
1035 | schedule_copy(tc, virt_block, tc->origin_dev, | |
1036 | virt_block, data_dest, cell, bio); | |
1037 | } | |
1038 | ||
991d9fa0 JT |
1039 | static void schedule_zero(struct thin_c *tc, dm_block_t virt_block, |
1040 | dm_block_t data_block, struct cell *cell, | |
1041 | struct bio *bio) | |
1042 | { | |
1043 | struct pool *pool = tc->pool; | |
1044 | struct new_mapping *m = get_next_mapping(pool); | |
1045 | ||
1046 | INIT_LIST_HEAD(&m->list); | |
eb2aa48d | 1047 | m->quiesced = 1; |
991d9fa0 JT |
1048 | m->prepared = 0; |
1049 | m->tc = tc; | |
1050 | m->virt_block = virt_block; | |
1051 | m->data_block = data_block; | |
1052 | m->cell = cell; | |
1053 | m->err = 0; | |
1054 | m->bio = NULL; | |
1055 | ||
1056 | /* | |
1057 | * If the whole block of data is being overwritten or we are not | |
1058 | * zeroing pre-existing data, we can issue the bio immediately. | |
1059 | * Otherwise we use kcopyd to zero the data first. | |
1060 | */ | |
67e2e2b2 | 1061 | if (!pool->pf.zero_new_blocks) |
991d9fa0 JT |
1062 | process_prepared_mapping(m); |
1063 | ||
1064 | else if (io_overwrites_block(pool, bio)) { | |
eb2aa48d JT |
1065 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
1066 | h->overwrite_mapping = m; | |
991d9fa0 JT |
1067 | m->bio = bio; |
1068 | save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio); | |
991d9fa0 JT |
1069 | remap_and_issue(tc, bio, data_block); |
1070 | ||
1071 | } else { | |
1072 | int r; | |
1073 | struct dm_io_region to; | |
1074 | ||
1075 | to.bdev = tc->pool_dev->bdev; | |
1076 | to.sector = data_block * pool->sectors_per_block; | |
1077 | to.count = pool->sectors_per_block; | |
1078 | ||
1079 | r = dm_kcopyd_zero(pool->copier, 1, &to, 0, copy_complete, m); | |
1080 | if (r < 0) { | |
1081 | mempool_free(m, pool->mapping_pool); | |
1082 | DMERR("dm_kcopyd_zero() failed"); | |
1083 | cell_error(cell); | |
1084 | } | |
1085 | } | |
1086 | } | |
1087 | ||
1088 | static int alloc_data_block(struct thin_c *tc, dm_block_t *result) | |
1089 | { | |
1090 | int r; | |
1091 | dm_block_t free_blocks; | |
1092 | unsigned long flags; | |
1093 | struct pool *pool = tc->pool; | |
1094 | ||
1095 | r = dm_pool_get_free_block_count(pool->pmd, &free_blocks); | |
1096 | if (r) | |
1097 | return r; | |
1098 | ||
1099 | if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) { | |
1100 | DMWARN("%s: reached low water mark, sending event.", | |
1101 | dm_device_name(pool->pool_md)); | |
1102 | spin_lock_irqsave(&pool->lock, flags); | |
1103 | pool->low_water_triggered = 1; | |
1104 | spin_unlock_irqrestore(&pool->lock, flags); | |
1105 | dm_table_event(pool->ti->table); | |
1106 | } | |
1107 | ||
1108 | if (!free_blocks) { | |
1109 | if (pool->no_free_space) | |
1110 | return -ENOSPC; | |
1111 | else { | |
1112 | /* | |
1113 | * Try to commit to see if that will free up some | |
1114 | * more space. | |
1115 | */ | |
1116 | r = dm_pool_commit_metadata(pool->pmd); | |
1117 | if (r) { | |
1118 | DMERR("%s: dm_pool_commit_metadata() failed, error = %d", | |
1119 | __func__, r); | |
1120 | return r; | |
1121 | } | |
1122 | ||
1123 | r = dm_pool_get_free_block_count(pool->pmd, &free_blocks); | |
1124 | if (r) | |
1125 | return r; | |
1126 | ||
1127 | /* | |
1128 | * If we still have no space we set a flag to avoid | |
1129 | * doing all this checking and return -ENOSPC. | |
1130 | */ | |
1131 | if (!free_blocks) { | |
1132 | DMWARN("%s: no free space available.", | |
1133 | dm_device_name(pool->pool_md)); | |
1134 | spin_lock_irqsave(&pool->lock, flags); | |
1135 | pool->no_free_space = 1; | |
1136 | spin_unlock_irqrestore(&pool->lock, flags); | |
1137 | return -ENOSPC; | |
1138 | } | |
1139 | } | |
1140 | } | |
1141 | ||
1142 | r = dm_pool_alloc_data_block(pool->pmd, result); | |
1143 | if (r) | |
1144 | return r; | |
1145 | ||
1146 | return 0; | |
1147 | } | |
1148 | ||
1149 | /* | |
1150 | * If we have run out of space, queue bios until the device is | |
1151 | * resumed, presumably after having been reloaded with more space. | |
1152 | */ | |
1153 | static void retry_on_resume(struct bio *bio) | |
1154 | { | |
eb2aa48d JT |
1155 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
1156 | struct thin_c *tc = h->tc; | |
991d9fa0 JT |
1157 | struct pool *pool = tc->pool; |
1158 | unsigned long flags; | |
1159 | ||
1160 | spin_lock_irqsave(&pool->lock, flags); | |
1161 | bio_list_add(&pool->retry_on_resume_list, bio); | |
1162 | spin_unlock_irqrestore(&pool->lock, flags); | |
1163 | } | |
1164 | ||
1165 | static void no_space(struct cell *cell) | |
1166 | { | |
1167 | struct bio *bio; | |
1168 | struct bio_list bios; | |
1169 | ||
1170 | bio_list_init(&bios); | |
1171 | cell_release(cell, &bios); | |
1172 | ||
1173 | while ((bio = bio_list_pop(&bios))) | |
1174 | retry_on_resume(bio); | |
1175 | } | |
1176 | ||
104655fd JT |
1177 | static void process_discard(struct thin_c *tc, struct bio *bio) |
1178 | { | |
1179 | int r; | |
1180 | struct pool *pool = tc->pool; | |
1181 | struct cell *cell, *cell2; | |
1182 | struct cell_key key, key2; | |
1183 | dm_block_t block = get_bio_block(tc, bio); | |
1184 | struct dm_thin_lookup_result lookup_result; | |
1185 | struct new_mapping *m; | |
1186 | ||
1187 | build_virtual_key(tc->td, block, &key); | |
1188 | if (bio_detain(tc->pool->prison, &key, bio, &cell)) | |
1189 | return; | |
1190 | ||
1191 | r = dm_thin_find_block(tc->td, block, 1, &lookup_result); | |
1192 | switch (r) { | |
1193 | case 0: | |
1194 | /* | |
1195 | * Check nobody is fiddling with this pool block. This can | |
1196 | * happen if someone's in the process of breaking sharing | |
1197 | * on this block. | |
1198 | */ | |
1199 | build_data_key(tc->td, lookup_result.block, &key2); | |
1200 | if (bio_detain(tc->pool->prison, &key2, bio, &cell2)) { | |
1201 | cell_release_singleton(cell, bio); | |
1202 | break; | |
1203 | } | |
1204 | ||
1205 | if (io_overlaps_block(pool, bio)) { | |
1206 | /* | |
1207 | * IO may still be going to the destination block. We must | |
1208 | * quiesce before we can do the removal. | |
1209 | */ | |
1210 | m = get_next_mapping(pool); | |
1211 | m->tc = tc; | |
67e2e2b2 | 1212 | m->pass_discard = (!lookup_result.shared) & pool->pf.discard_passdown; |
104655fd JT |
1213 | m->virt_block = block; |
1214 | m->data_block = lookup_result.block; | |
1215 | m->cell = cell; | |
1216 | m->cell2 = cell2; | |
1217 | m->err = 0; | |
1218 | m->bio = bio; | |
1219 | ||
1220 | if (!ds_add_work(&pool->all_io_ds, &m->list)) { | |
1221 | list_add(&m->list, &pool->prepared_discards); | |
1222 | wake_worker(pool); | |
1223 | } | |
1224 | } else { | |
1225 | /* | |
1226 | * This path is hit if people are ignoring | |
1227 | * limits->discard_granularity. It ignores any | |
1228 | * part of the discard that is in a subsequent | |
1229 | * block. | |
1230 | */ | |
1231 | sector_t offset = bio->bi_sector - (block << pool->block_shift); | |
1232 | unsigned remaining = (pool->sectors_per_block - offset) << 9; | |
1233 | bio->bi_size = min(bio->bi_size, remaining); | |
1234 | ||
1235 | cell_release_singleton(cell, bio); | |
1236 | cell_release_singleton(cell2, bio); | |
1237 | remap_and_issue(tc, bio, lookup_result.block); | |
1238 | } | |
1239 | break; | |
1240 | ||
1241 | case -ENODATA: | |
1242 | /* | |
1243 | * It isn't provisioned, just forget it. | |
1244 | */ | |
1245 | cell_release_singleton(cell, bio); | |
1246 | bio_endio(bio, 0); | |
1247 | break; | |
1248 | ||
1249 | default: | |
1250 | DMERR("discard: find block unexpectedly returned %d", r); | |
1251 | cell_release_singleton(cell, bio); | |
1252 | bio_io_error(bio); | |
1253 | break; | |
1254 | } | |
1255 | } | |
1256 | ||
991d9fa0 JT |
1257 | static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block, |
1258 | struct cell_key *key, | |
1259 | struct dm_thin_lookup_result *lookup_result, | |
1260 | struct cell *cell) | |
1261 | { | |
1262 | int r; | |
1263 | dm_block_t data_block; | |
1264 | ||
1265 | r = alloc_data_block(tc, &data_block); | |
1266 | switch (r) { | |
1267 | case 0: | |
2dd9c257 JT |
1268 | schedule_internal_copy(tc, block, lookup_result->block, |
1269 | data_block, cell, bio); | |
991d9fa0 JT |
1270 | break; |
1271 | ||
1272 | case -ENOSPC: | |
1273 | no_space(cell); | |
1274 | break; | |
1275 | ||
1276 | default: | |
1277 | DMERR("%s: alloc_data_block() failed, error = %d", __func__, r); | |
1278 | cell_error(cell); | |
1279 | break; | |
1280 | } | |
1281 | } | |
1282 | ||
1283 | static void process_shared_bio(struct thin_c *tc, struct bio *bio, | |
1284 | dm_block_t block, | |
1285 | struct dm_thin_lookup_result *lookup_result) | |
1286 | { | |
1287 | struct cell *cell; | |
1288 | struct pool *pool = tc->pool; | |
1289 | struct cell_key key; | |
1290 | ||
1291 | /* | |
1292 | * If cell is already occupied, then sharing is already in the process | |
1293 | * of being broken so we have nothing further to do here. | |
1294 | */ | |
1295 | build_data_key(tc->td, lookup_result->block, &key); | |
1296 | if (bio_detain(pool->prison, &key, bio, &cell)) | |
1297 | return; | |
1298 | ||
1299 | if (bio_data_dir(bio) == WRITE) | |
1300 | break_sharing(tc, bio, block, &key, lookup_result, cell); | |
1301 | else { | |
eb2aa48d | 1302 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
991d9fa0 | 1303 | |
eb2aa48d | 1304 | h->shared_read_entry = ds_inc(&pool->shared_read_ds); |
991d9fa0 JT |
1305 | |
1306 | cell_release_singleton(cell, bio); | |
1307 | remap_and_issue(tc, bio, lookup_result->block); | |
1308 | } | |
1309 | } | |
1310 | ||
1311 | static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block, | |
1312 | struct cell *cell) | |
1313 | { | |
1314 | int r; | |
1315 | dm_block_t data_block; | |
1316 | ||
1317 | /* | |
1318 | * Remap empty bios (flushes) immediately, without provisioning. | |
1319 | */ | |
1320 | if (!bio->bi_size) { | |
1321 | cell_release_singleton(cell, bio); | |
1322 | remap_and_issue(tc, bio, 0); | |
1323 | return; | |
1324 | } | |
1325 | ||
1326 | /* | |
1327 | * Fill read bios with zeroes and complete them immediately. | |
1328 | */ | |
1329 | if (bio_data_dir(bio) == READ) { | |
1330 | zero_fill_bio(bio); | |
1331 | cell_release_singleton(cell, bio); | |
1332 | bio_endio(bio, 0); | |
1333 | return; | |
1334 | } | |
1335 | ||
1336 | r = alloc_data_block(tc, &data_block); | |
1337 | switch (r) { | |
1338 | case 0: | |
2dd9c257 JT |
1339 | if (tc->origin_dev) |
1340 | schedule_external_copy(tc, block, data_block, cell, bio); | |
1341 | else | |
1342 | schedule_zero(tc, block, data_block, cell, bio); | |
991d9fa0 JT |
1343 | break; |
1344 | ||
1345 | case -ENOSPC: | |
1346 | no_space(cell); | |
1347 | break; | |
1348 | ||
1349 | default: | |
1350 | DMERR("%s: alloc_data_block() failed, error = %d", __func__, r); | |
1351 | cell_error(cell); | |
1352 | break; | |
1353 | } | |
1354 | } | |
1355 | ||
1356 | static void process_bio(struct thin_c *tc, struct bio *bio) | |
1357 | { | |
1358 | int r; | |
1359 | dm_block_t block = get_bio_block(tc, bio); | |
1360 | struct cell *cell; | |
1361 | struct cell_key key; | |
1362 | struct dm_thin_lookup_result lookup_result; | |
1363 | ||
1364 | /* | |
1365 | * If cell is already occupied, then the block is already | |
1366 | * being provisioned so we have nothing further to do here. | |
1367 | */ | |
1368 | build_virtual_key(tc->td, block, &key); | |
1369 | if (bio_detain(tc->pool->prison, &key, bio, &cell)) | |
1370 | return; | |
1371 | ||
1372 | r = dm_thin_find_block(tc->td, block, 1, &lookup_result); | |
1373 | switch (r) { | |
1374 | case 0: | |
1375 | /* | |
1376 | * We can release this cell now. This thread is the only | |
1377 | * one that puts bios into a cell, and we know there were | |
1378 | * no preceding bios. | |
1379 | */ | |
1380 | /* | |
1381 | * TODO: this will probably have to change when discard goes | |
1382 | * back in. | |
1383 | */ | |
1384 | cell_release_singleton(cell, bio); | |
1385 | ||
1386 | if (lookup_result.shared) | |
1387 | process_shared_bio(tc, bio, block, &lookup_result); | |
1388 | else | |
1389 | remap_and_issue(tc, bio, lookup_result.block); | |
1390 | break; | |
1391 | ||
1392 | case -ENODATA: | |
2dd9c257 JT |
1393 | if (bio_data_dir(bio) == READ && tc->origin_dev) { |
1394 | cell_release_singleton(cell, bio); | |
1395 | remap_to_origin_and_issue(tc, bio); | |
1396 | } else | |
1397 | provision_block(tc, bio, block, cell); | |
991d9fa0 JT |
1398 | break; |
1399 | ||
1400 | default: | |
1401 | DMERR("dm_thin_find_block() failed, error = %d", r); | |
104655fd | 1402 | cell_release_singleton(cell, bio); |
991d9fa0 JT |
1403 | bio_io_error(bio); |
1404 | break; | |
1405 | } | |
1406 | } | |
1407 | ||
905e51b3 JT |
1408 | static int need_commit_due_to_time(struct pool *pool) |
1409 | { | |
1410 | return jiffies < pool->last_commit_jiffies || | |
1411 | jiffies > pool->last_commit_jiffies + COMMIT_PERIOD; | |
1412 | } | |
1413 | ||
991d9fa0 JT |
1414 | static void process_deferred_bios(struct pool *pool) |
1415 | { | |
1416 | unsigned long flags; | |
1417 | struct bio *bio; | |
1418 | struct bio_list bios; | |
1419 | int r; | |
1420 | ||
1421 | bio_list_init(&bios); | |
1422 | ||
1423 | spin_lock_irqsave(&pool->lock, flags); | |
1424 | bio_list_merge(&bios, &pool->deferred_bios); | |
1425 | bio_list_init(&pool->deferred_bios); | |
1426 | spin_unlock_irqrestore(&pool->lock, flags); | |
1427 | ||
1428 | while ((bio = bio_list_pop(&bios))) { | |
eb2aa48d JT |
1429 | struct endio_hook *h = dm_get_mapinfo(bio)->ptr; |
1430 | struct thin_c *tc = h->tc; | |
1431 | ||
991d9fa0 JT |
1432 | /* |
1433 | * If we've got no free new_mapping structs, and processing | |
1434 | * this bio might require one, we pause until there are some | |
1435 | * prepared mappings to process. | |
1436 | */ | |
1437 | if (ensure_next_mapping(pool)) { | |
1438 | spin_lock_irqsave(&pool->lock, flags); | |
1439 | bio_list_merge(&pool->deferred_bios, &bios); | |
1440 | spin_unlock_irqrestore(&pool->lock, flags); | |
1441 | ||
1442 | break; | |
1443 | } | |
104655fd JT |
1444 | |
1445 | if (bio->bi_rw & REQ_DISCARD) | |
1446 | process_discard(tc, bio); | |
1447 | else | |
1448 | process_bio(tc, bio); | |
991d9fa0 JT |
1449 | } |
1450 | ||
1451 | /* | |
1452 | * If there are any deferred flush bios, we must commit | |
1453 | * the metadata before issuing them. | |
1454 | */ | |
1455 | bio_list_init(&bios); | |
1456 | spin_lock_irqsave(&pool->lock, flags); | |
1457 | bio_list_merge(&bios, &pool->deferred_flush_bios); | |
1458 | bio_list_init(&pool->deferred_flush_bios); | |
1459 | spin_unlock_irqrestore(&pool->lock, flags); | |
1460 | ||
905e51b3 | 1461 | if (bio_list_empty(&bios) && !need_commit_due_to_time(pool)) |
991d9fa0 JT |
1462 | return; |
1463 | ||
1464 | r = dm_pool_commit_metadata(pool->pmd); | |
1465 | if (r) { | |
1466 | DMERR("%s: dm_pool_commit_metadata() failed, error = %d", | |
1467 | __func__, r); | |
1468 | while ((bio = bio_list_pop(&bios))) | |
1469 | bio_io_error(bio); | |
1470 | return; | |
1471 | } | |
905e51b3 | 1472 | pool->last_commit_jiffies = jiffies; |
991d9fa0 JT |
1473 | |
1474 | while ((bio = bio_list_pop(&bios))) | |
1475 | generic_make_request(bio); | |
1476 | } | |
1477 | ||
1478 | static void do_worker(struct work_struct *ws) | |
1479 | { | |
1480 | struct pool *pool = container_of(ws, struct pool, worker); | |
1481 | ||
104655fd JT |
1482 | process_prepared(pool, &pool->prepared_mappings, process_prepared_mapping); |
1483 | process_prepared(pool, &pool->prepared_discards, process_prepared_discard); | |
991d9fa0 JT |
1484 | process_deferred_bios(pool); |
1485 | } | |
1486 | ||
905e51b3 JT |
1487 | /* |
1488 | * We want to commit periodically so that not too much | |
1489 | * unwritten data builds up. | |
1490 | */ | |
1491 | static void do_waker(struct work_struct *ws) | |
1492 | { | |
1493 | struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker); | |
1494 | wake_worker(pool); | |
1495 | queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD); | |
1496 | } | |
1497 | ||
991d9fa0 JT |
1498 | /*----------------------------------------------------------------*/ |
1499 | ||
1500 | /* | |
1501 | * Mapping functions. | |
1502 | */ | |
1503 | ||
1504 | /* | |
1505 | * Called only while mapping a thin bio to hand it over to the workqueue. | |
1506 | */ | |
1507 | static void thin_defer_bio(struct thin_c *tc, struct bio *bio) | |
1508 | { | |
1509 | unsigned long flags; | |
1510 | struct pool *pool = tc->pool; | |
1511 | ||
1512 | spin_lock_irqsave(&pool->lock, flags); | |
1513 | bio_list_add(&pool->deferred_bios, bio); | |
1514 | spin_unlock_irqrestore(&pool->lock, flags); | |
1515 | ||
1516 | wake_worker(pool); | |
1517 | } | |
1518 | ||
eb2aa48d JT |
1519 | static struct endio_hook *thin_hook_bio(struct thin_c *tc, struct bio *bio) |
1520 | { | |
1521 | struct pool *pool = tc->pool; | |
1522 | struct endio_hook *h = mempool_alloc(pool->endio_hook_pool, GFP_NOIO); | |
1523 | ||
1524 | h->tc = tc; | |
1525 | h->shared_read_entry = NULL; | |
104655fd | 1526 | h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : ds_inc(&pool->all_io_ds); |
eb2aa48d JT |
1527 | h->overwrite_mapping = NULL; |
1528 | ||
1529 | return h; | |
1530 | } | |
1531 | ||
991d9fa0 JT |
1532 | /* |
1533 | * Non-blocking function called from the thin target's map function. | |
1534 | */ | |
1535 | static int thin_bio_map(struct dm_target *ti, struct bio *bio, | |
1536 | union map_info *map_context) | |
1537 | { | |
1538 | int r; | |
1539 | struct thin_c *tc = ti->private; | |
1540 | dm_block_t block = get_bio_block(tc, bio); | |
1541 | struct dm_thin_device *td = tc->td; | |
1542 | struct dm_thin_lookup_result result; | |
1543 | ||
eb2aa48d | 1544 | map_context->ptr = thin_hook_bio(tc, bio); |
104655fd | 1545 | if (bio->bi_rw & (REQ_DISCARD | REQ_FLUSH | REQ_FUA)) { |
991d9fa0 JT |
1546 | thin_defer_bio(tc, bio); |
1547 | return DM_MAPIO_SUBMITTED; | |
1548 | } | |
1549 | ||
1550 | r = dm_thin_find_block(td, block, 0, &result); | |
1551 | ||
1552 | /* | |
1553 | * Note that we defer readahead too. | |
1554 | */ | |
1555 | switch (r) { | |
1556 | case 0: | |
1557 | if (unlikely(result.shared)) { | |
1558 | /* | |
1559 | * We have a race condition here between the | |
1560 | * result.shared value returned by the lookup and | |
1561 | * snapshot creation, which may cause new | |
1562 | * sharing. | |
1563 | * | |
1564 | * To avoid this always quiesce the origin before | |
1565 | * taking the snap. You want to do this anyway to | |
1566 | * ensure a consistent application view | |
1567 | * (i.e. lockfs). | |
1568 | * | |
1569 | * More distant ancestors are irrelevant. The | |
1570 | * shared flag will be set in their case. | |
1571 | */ | |
1572 | thin_defer_bio(tc, bio); | |
1573 | r = DM_MAPIO_SUBMITTED; | |
1574 | } else { | |
1575 | remap(tc, bio, result.block); | |
1576 | r = DM_MAPIO_REMAPPED; | |
1577 | } | |
1578 | break; | |
1579 | ||
1580 | case -ENODATA: | |
1581 | /* | |
1582 | * In future, the failed dm_thin_find_block above could | |
1583 | * provide the hint to load the metadata into cache. | |
1584 | */ | |
1585 | case -EWOULDBLOCK: | |
1586 | thin_defer_bio(tc, bio); | |
1587 | r = DM_MAPIO_SUBMITTED; | |
1588 | break; | |
1589 | } | |
1590 | ||
1591 | return r; | |
1592 | } | |
1593 | ||
1594 | static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits) | |
1595 | { | |
1596 | int r; | |
1597 | unsigned long flags; | |
1598 | struct pool_c *pt = container_of(cb, struct pool_c, callbacks); | |
1599 | ||
1600 | spin_lock_irqsave(&pt->pool->lock, flags); | |
1601 | r = !bio_list_empty(&pt->pool->retry_on_resume_list); | |
1602 | spin_unlock_irqrestore(&pt->pool->lock, flags); | |
1603 | ||
1604 | if (!r) { | |
1605 | struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); | |
1606 | r = bdi_congested(&q->backing_dev_info, bdi_bits); | |
1607 | } | |
1608 | ||
1609 | return r; | |
1610 | } | |
1611 | ||
1612 | static void __requeue_bios(struct pool *pool) | |
1613 | { | |
1614 | bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list); | |
1615 | bio_list_init(&pool->retry_on_resume_list); | |
1616 | } | |
1617 | ||
1618 | /*---------------------------------------------------------------- | |
1619 | * Binding of control targets to a pool object | |
1620 | *--------------------------------------------------------------*/ | |
1621 | static int bind_control_target(struct pool *pool, struct dm_target *ti) | |
1622 | { | |
1623 | struct pool_c *pt = ti->private; | |
1624 | ||
1625 | pool->ti = ti; | |
1626 | pool->low_water_blocks = pt->low_water_blocks; | |
67e2e2b2 | 1627 | pool->pf = pt->pf; |
991d9fa0 JT |
1628 | |
1629 | return 0; | |
1630 | } | |
1631 | ||
1632 | static void unbind_control_target(struct pool *pool, struct dm_target *ti) | |
1633 | { | |
1634 | if (pool->ti == ti) | |
1635 | pool->ti = NULL; | |
1636 | } | |
1637 | ||
1638 | /*---------------------------------------------------------------- | |
1639 | * Pool creation | |
1640 | *--------------------------------------------------------------*/ | |
67e2e2b2 JT |
1641 | /* Initialize pool features. */ |
1642 | static void pool_features_init(struct pool_features *pf) | |
1643 | { | |
1644 | pf->zero_new_blocks = 1; | |
1645 | pf->discard_enabled = 1; | |
1646 | pf->discard_passdown = 1; | |
1647 | } | |
1648 | ||
991d9fa0 JT |
1649 | static void __pool_destroy(struct pool *pool) |
1650 | { | |
1651 | __pool_table_remove(pool); | |
1652 | ||
1653 | if (dm_pool_metadata_close(pool->pmd) < 0) | |
1654 | DMWARN("%s: dm_pool_metadata_close() failed.", __func__); | |
1655 | ||
1656 | prison_destroy(pool->prison); | |
1657 | dm_kcopyd_client_destroy(pool->copier); | |
1658 | ||
1659 | if (pool->wq) | |
1660 | destroy_workqueue(pool->wq); | |
1661 | ||
1662 | if (pool->next_mapping) | |
1663 | mempool_free(pool->next_mapping, pool->mapping_pool); | |
1664 | mempool_destroy(pool->mapping_pool); | |
1665 | mempool_destroy(pool->endio_hook_pool); | |
1666 | kfree(pool); | |
1667 | } | |
1668 | ||
1669 | static struct pool *pool_create(struct mapped_device *pool_md, | |
1670 | struct block_device *metadata_dev, | |
1671 | unsigned long block_size, char **error) | |
1672 | { | |
1673 | int r; | |
1674 | void *err_p; | |
1675 | struct pool *pool; | |
1676 | struct dm_pool_metadata *pmd; | |
1677 | ||
1678 | pmd = dm_pool_metadata_open(metadata_dev, block_size); | |
1679 | if (IS_ERR(pmd)) { | |
1680 | *error = "Error creating metadata object"; | |
1681 | return (struct pool *)pmd; | |
1682 | } | |
1683 | ||
1684 | pool = kmalloc(sizeof(*pool), GFP_KERNEL); | |
1685 | if (!pool) { | |
1686 | *error = "Error allocating memory for pool"; | |
1687 | err_p = ERR_PTR(-ENOMEM); | |
1688 | goto bad_pool; | |
1689 | } | |
1690 | ||
1691 | pool->pmd = pmd; | |
1692 | pool->sectors_per_block = block_size; | |
1693 | pool->block_shift = ffs(block_size) - 1; | |
1694 | pool->offset_mask = block_size - 1; | |
1695 | pool->low_water_blocks = 0; | |
67e2e2b2 | 1696 | pool_features_init(&pool->pf); |
991d9fa0 JT |
1697 | pool->prison = prison_create(PRISON_CELLS); |
1698 | if (!pool->prison) { | |
1699 | *error = "Error creating pool's bio prison"; | |
1700 | err_p = ERR_PTR(-ENOMEM); | |
1701 | goto bad_prison; | |
1702 | } | |
1703 | ||
1704 | pool->copier = dm_kcopyd_client_create(); | |
1705 | if (IS_ERR(pool->copier)) { | |
1706 | r = PTR_ERR(pool->copier); | |
1707 | *error = "Error creating pool's kcopyd client"; | |
1708 | err_p = ERR_PTR(r); | |
1709 | goto bad_kcopyd_client; | |
1710 | } | |
1711 | ||
1712 | /* | |
1713 | * Create singlethreaded workqueue that will service all devices | |
1714 | * that use this metadata. | |
1715 | */ | |
1716 | pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); | |
1717 | if (!pool->wq) { | |
1718 | *error = "Error creating pool's workqueue"; | |
1719 | err_p = ERR_PTR(-ENOMEM); | |
1720 | goto bad_wq; | |
1721 | } | |
1722 | ||
1723 | INIT_WORK(&pool->worker, do_worker); | |
905e51b3 | 1724 | INIT_DELAYED_WORK(&pool->waker, do_waker); |
991d9fa0 JT |
1725 | spin_lock_init(&pool->lock); |
1726 | bio_list_init(&pool->deferred_bios); | |
1727 | bio_list_init(&pool->deferred_flush_bios); | |
1728 | INIT_LIST_HEAD(&pool->prepared_mappings); | |
104655fd | 1729 | INIT_LIST_HEAD(&pool->prepared_discards); |
991d9fa0 JT |
1730 | pool->low_water_triggered = 0; |
1731 | pool->no_free_space = 0; | |
1732 | bio_list_init(&pool->retry_on_resume_list); | |
eb2aa48d | 1733 | ds_init(&pool->shared_read_ds); |
104655fd | 1734 | ds_init(&pool->all_io_ds); |
991d9fa0 JT |
1735 | |
1736 | pool->next_mapping = NULL; | |
1737 | pool->mapping_pool = | |
1738 | mempool_create_kmalloc_pool(MAPPING_POOL_SIZE, sizeof(struct new_mapping)); | |
1739 | if (!pool->mapping_pool) { | |
1740 | *error = "Error creating pool's mapping mempool"; | |
1741 | err_p = ERR_PTR(-ENOMEM); | |
1742 | goto bad_mapping_pool; | |
1743 | } | |
1744 | ||
1745 | pool->endio_hook_pool = | |
1746 | mempool_create_kmalloc_pool(ENDIO_HOOK_POOL_SIZE, sizeof(struct endio_hook)); | |
1747 | if (!pool->endio_hook_pool) { | |
1748 | *error = "Error creating pool's endio_hook mempool"; | |
1749 | err_p = ERR_PTR(-ENOMEM); | |
1750 | goto bad_endio_hook_pool; | |
1751 | } | |
1752 | pool->ref_count = 1; | |
905e51b3 | 1753 | pool->last_commit_jiffies = jiffies; |
991d9fa0 JT |
1754 | pool->pool_md = pool_md; |
1755 | pool->md_dev = metadata_dev; | |
1756 | __pool_table_insert(pool); | |
1757 | ||
1758 | return pool; | |
1759 | ||
1760 | bad_endio_hook_pool: | |
1761 | mempool_destroy(pool->mapping_pool); | |
1762 | bad_mapping_pool: | |
1763 | destroy_workqueue(pool->wq); | |
1764 | bad_wq: | |
1765 | dm_kcopyd_client_destroy(pool->copier); | |
1766 | bad_kcopyd_client: | |
1767 | prison_destroy(pool->prison); | |
1768 | bad_prison: | |
1769 | kfree(pool); | |
1770 | bad_pool: | |
1771 | if (dm_pool_metadata_close(pmd)) | |
1772 | DMWARN("%s: dm_pool_metadata_close() failed.", __func__); | |
1773 | ||
1774 | return err_p; | |
1775 | } | |
1776 | ||
1777 | static void __pool_inc(struct pool *pool) | |
1778 | { | |
1779 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
1780 | pool->ref_count++; | |
1781 | } | |
1782 | ||
1783 | static void __pool_dec(struct pool *pool) | |
1784 | { | |
1785 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
1786 | BUG_ON(!pool->ref_count); | |
1787 | if (!--pool->ref_count) | |
1788 | __pool_destroy(pool); | |
1789 | } | |
1790 | ||
1791 | static struct pool *__pool_find(struct mapped_device *pool_md, | |
1792 | struct block_device *metadata_dev, | |
67e2e2b2 JT |
1793 | unsigned long block_size, char **error, |
1794 | int *created) | |
991d9fa0 JT |
1795 | { |
1796 | struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev); | |
1797 | ||
1798 | if (pool) { | |
1799 | if (pool->pool_md != pool_md) | |
1800 | return ERR_PTR(-EBUSY); | |
1801 | __pool_inc(pool); | |
1802 | ||
1803 | } else { | |
1804 | pool = __pool_table_lookup(pool_md); | |
1805 | if (pool) { | |
1806 | if (pool->md_dev != metadata_dev) | |
1807 | return ERR_PTR(-EINVAL); | |
1808 | __pool_inc(pool); | |
1809 | ||
67e2e2b2 | 1810 | } else { |
991d9fa0 | 1811 | pool = pool_create(pool_md, metadata_dev, block_size, error); |
67e2e2b2 JT |
1812 | *created = 1; |
1813 | } | |
991d9fa0 JT |
1814 | } |
1815 | ||
1816 | return pool; | |
1817 | } | |
1818 | ||
1819 | /*---------------------------------------------------------------- | |
1820 | * Pool target methods | |
1821 | *--------------------------------------------------------------*/ | |
1822 | static void pool_dtr(struct dm_target *ti) | |
1823 | { | |
1824 | struct pool_c *pt = ti->private; | |
1825 | ||
1826 | mutex_lock(&dm_thin_pool_table.mutex); | |
1827 | ||
1828 | unbind_control_target(pt->pool, ti); | |
1829 | __pool_dec(pt->pool); | |
1830 | dm_put_device(ti, pt->metadata_dev); | |
1831 | dm_put_device(ti, pt->data_dev); | |
1832 | kfree(pt); | |
1833 | ||
1834 | mutex_unlock(&dm_thin_pool_table.mutex); | |
1835 | } | |
1836 | ||
991d9fa0 JT |
1837 | static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf, |
1838 | struct dm_target *ti) | |
1839 | { | |
1840 | int r; | |
1841 | unsigned argc; | |
1842 | const char *arg_name; | |
1843 | ||
1844 | static struct dm_arg _args[] = { | |
67e2e2b2 | 1845 | {0, 3, "Invalid number of pool feature arguments"}, |
991d9fa0 JT |
1846 | }; |
1847 | ||
1848 | /* | |
1849 | * No feature arguments supplied. | |
1850 | */ | |
1851 | if (!as->argc) | |
1852 | return 0; | |
1853 | ||
1854 | r = dm_read_arg_group(_args, as, &argc, &ti->error); | |
1855 | if (r) | |
1856 | return -EINVAL; | |
1857 | ||
1858 | while (argc && !r) { | |
1859 | arg_name = dm_shift_arg(as); | |
1860 | argc--; | |
1861 | ||
1862 | if (!strcasecmp(arg_name, "skip_block_zeroing")) { | |
1863 | pf->zero_new_blocks = 0; | |
1864 | continue; | |
67e2e2b2 JT |
1865 | } else if (!strcasecmp(arg_name, "ignore_discard")) { |
1866 | pf->discard_enabled = 0; | |
1867 | continue; | |
1868 | } else if (!strcasecmp(arg_name, "no_discard_passdown")) { | |
1869 | pf->discard_passdown = 0; | |
1870 | continue; | |
991d9fa0 JT |
1871 | } |
1872 | ||
1873 | ti->error = "Unrecognised pool feature requested"; | |
1874 | r = -EINVAL; | |
1875 | } | |
1876 | ||
1877 | return r; | |
1878 | } | |
1879 | ||
1880 | /* | |
1881 | * thin-pool <metadata dev> <data dev> | |
1882 | * <data block size (sectors)> | |
1883 | * <low water mark (blocks)> | |
1884 | * [<#feature args> [<arg>]*] | |
1885 | * | |
1886 | * Optional feature arguments are: | |
1887 | * skip_block_zeroing: skips the zeroing of newly-provisioned blocks. | |
67e2e2b2 JT |
1888 | * ignore_discard: disable discard |
1889 | * no_discard_passdown: don't pass discards down to the data device | |
991d9fa0 JT |
1890 | */ |
1891 | static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
1892 | { | |
67e2e2b2 | 1893 | int r, pool_created = 0; |
991d9fa0 JT |
1894 | struct pool_c *pt; |
1895 | struct pool *pool; | |
1896 | struct pool_features pf; | |
1897 | struct dm_arg_set as; | |
1898 | struct dm_dev *data_dev; | |
1899 | unsigned long block_size; | |
1900 | dm_block_t low_water_blocks; | |
1901 | struct dm_dev *metadata_dev; | |
1902 | sector_t metadata_dev_size; | |
c4a69ecd | 1903 | char b[BDEVNAME_SIZE]; |
991d9fa0 JT |
1904 | |
1905 | /* | |
1906 | * FIXME Remove validation from scope of lock. | |
1907 | */ | |
1908 | mutex_lock(&dm_thin_pool_table.mutex); | |
1909 | ||
1910 | if (argc < 4) { | |
1911 | ti->error = "Invalid argument count"; | |
1912 | r = -EINVAL; | |
1913 | goto out_unlock; | |
1914 | } | |
1915 | as.argc = argc; | |
1916 | as.argv = argv; | |
1917 | ||
1918 | r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &metadata_dev); | |
1919 | if (r) { | |
1920 | ti->error = "Error opening metadata block device"; | |
1921 | goto out_unlock; | |
1922 | } | |
1923 | ||
1924 | metadata_dev_size = i_size_read(metadata_dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
c4a69ecd MS |
1925 | if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING) |
1926 | DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.", | |
1927 | bdevname(metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS); | |
991d9fa0 JT |
1928 | |
1929 | r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev); | |
1930 | if (r) { | |
1931 | ti->error = "Error getting data device"; | |
1932 | goto out_metadata; | |
1933 | } | |
1934 | ||
1935 | if (kstrtoul(argv[2], 10, &block_size) || !block_size || | |
1936 | block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS || | |
1937 | block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS || | |
1938 | !is_power_of_2(block_size)) { | |
1939 | ti->error = "Invalid block size"; | |
1940 | r = -EINVAL; | |
1941 | goto out; | |
1942 | } | |
1943 | ||
1944 | if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) { | |
1945 | ti->error = "Invalid low water mark"; | |
1946 | r = -EINVAL; | |
1947 | goto out; | |
1948 | } | |
1949 | ||
1950 | /* | |
1951 | * Set default pool features. | |
1952 | */ | |
67e2e2b2 | 1953 | pool_features_init(&pf); |
991d9fa0 JT |
1954 | |
1955 | dm_consume_args(&as, 4); | |
1956 | r = parse_pool_features(&as, &pf, ti); | |
1957 | if (r) | |
1958 | goto out; | |
1959 | ||
1960 | pt = kzalloc(sizeof(*pt), GFP_KERNEL); | |
1961 | if (!pt) { | |
1962 | r = -ENOMEM; | |
1963 | goto out; | |
1964 | } | |
1965 | ||
1966 | pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev, | |
67e2e2b2 | 1967 | block_size, &ti->error, &pool_created); |
991d9fa0 JT |
1968 | if (IS_ERR(pool)) { |
1969 | r = PTR_ERR(pool); | |
1970 | goto out_free_pt; | |
1971 | } | |
1972 | ||
67e2e2b2 JT |
1973 | /* |
1974 | * 'pool_created' reflects whether this is the first table load. | |
1975 | * Top level discard support is not allowed to be changed after | |
1976 | * initial load. This would require a pool reload to trigger thin | |
1977 | * device changes. | |
1978 | */ | |
1979 | if (!pool_created && pf.discard_enabled != pool->pf.discard_enabled) { | |
1980 | ti->error = "Discard support cannot be disabled once enabled"; | |
1981 | r = -EINVAL; | |
1982 | goto out_flags_changed; | |
1983 | } | |
1984 | ||
1985 | /* | |
1986 | * If discard_passdown was enabled verify that the data device | |
1987 | * supports discards. Disable discard_passdown if not; otherwise | |
1988 | * -EOPNOTSUPP will be returned. | |
1989 | */ | |
1990 | if (pf.discard_passdown) { | |
1991 | struct request_queue *q = bdev_get_queue(data_dev->bdev); | |
1992 | if (!q || !blk_queue_discard(q)) { | |
1993 | DMWARN("Discard unsupported by data device: Disabling discard passdown."); | |
1994 | pf.discard_passdown = 0; | |
1995 | } | |
1996 | } | |
1997 | ||
991d9fa0 JT |
1998 | pt->pool = pool; |
1999 | pt->ti = ti; | |
2000 | pt->metadata_dev = metadata_dev; | |
2001 | pt->data_dev = data_dev; | |
2002 | pt->low_water_blocks = low_water_blocks; | |
67e2e2b2 | 2003 | pt->pf = pf; |
991d9fa0 | 2004 | ti->num_flush_requests = 1; |
67e2e2b2 JT |
2005 | /* |
2006 | * Only need to enable discards if the pool should pass | |
2007 | * them down to the data device. The thin device's discard | |
2008 | * processing will cause mappings to be removed from the btree. | |
2009 | */ | |
2010 | if (pf.discard_enabled && pf.discard_passdown) { | |
2011 | ti->num_discard_requests = 1; | |
2012 | /* | |
2013 | * Setting 'discards_supported' circumvents the normal | |
2014 | * stacking of discard limits (this keeps the pool and | |
2015 | * thin devices' discard limits consistent). | |
2016 | */ | |
2017 | ti->discards_supported = 1; | |
2018 | } | |
991d9fa0 JT |
2019 | ti->private = pt; |
2020 | ||
2021 | pt->callbacks.congested_fn = pool_is_congested; | |
2022 | dm_table_add_target_callbacks(ti->table, &pt->callbacks); | |
2023 | ||
2024 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2025 | ||
2026 | return 0; | |
2027 | ||
67e2e2b2 JT |
2028 | out_flags_changed: |
2029 | __pool_dec(pool); | |
991d9fa0 JT |
2030 | out_free_pt: |
2031 | kfree(pt); | |
2032 | out: | |
2033 | dm_put_device(ti, data_dev); | |
2034 | out_metadata: | |
2035 | dm_put_device(ti, metadata_dev); | |
2036 | out_unlock: | |
2037 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2038 | ||
2039 | return r; | |
2040 | } | |
2041 | ||
2042 | static int pool_map(struct dm_target *ti, struct bio *bio, | |
2043 | union map_info *map_context) | |
2044 | { | |
2045 | int r; | |
2046 | struct pool_c *pt = ti->private; | |
2047 | struct pool *pool = pt->pool; | |
2048 | unsigned long flags; | |
2049 | ||
2050 | /* | |
2051 | * As this is a singleton target, ti->begin is always zero. | |
2052 | */ | |
2053 | spin_lock_irqsave(&pool->lock, flags); | |
2054 | bio->bi_bdev = pt->data_dev->bdev; | |
2055 | r = DM_MAPIO_REMAPPED; | |
2056 | spin_unlock_irqrestore(&pool->lock, flags); | |
2057 | ||
2058 | return r; | |
2059 | } | |
2060 | ||
2061 | /* | |
2062 | * Retrieves the number of blocks of the data device from | |
2063 | * the superblock and compares it to the actual device size, | |
2064 | * thus resizing the data device in case it has grown. | |
2065 | * | |
2066 | * This both copes with opening preallocated data devices in the ctr | |
2067 | * being followed by a resume | |
2068 | * -and- | |
2069 | * calling the resume method individually after userspace has | |
2070 | * grown the data device in reaction to a table event. | |
2071 | */ | |
2072 | static int pool_preresume(struct dm_target *ti) | |
2073 | { | |
2074 | int r; | |
2075 | struct pool_c *pt = ti->private; | |
2076 | struct pool *pool = pt->pool; | |
2077 | dm_block_t data_size, sb_data_size; | |
2078 | ||
2079 | /* | |
2080 | * Take control of the pool object. | |
2081 | */ | |
2082 | r = bind_control_target(pool, ti); | |
2083 | if (r) | |
2084 | return r; | |
2085 | ||
2086 | data_size = ti->len >> pool->block_shift; | |
2087 | r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size); | |
2088 | if (r) { | |
2089 | DMERR("failed to retrieve data device size"); | |
2090 | return r; | |
2091 | } | |
2092 | ||
2093 | if (data_size < sb_data_size) { | |
2094 | DMERR("pool target too small, is %llu blocks (expected %llu)", | |
2095 | data_size, sb_data_size); | |
2096 | return -EINVAL; | |
2097 | ||
2098 | } else if (data_size > sb_data_size) { | |
2099 | r = dm_pool_resize_data_dev(pool->pmd, data_size); | |
2100 | if (r) { | |
2101 | DMERR("failed to resize data device"); | |
2102 | return r; | |
2103 | } | |
2104 | ||
2105 | r = dm_pool_commit_metadata(pool->pmd); | |
2106 | if (r) { | |
2107 | DMERR("%s: dm_pool_commit_metadata() failed, error = %d", | |
2108 | __func__, r); | |
2109 | return r; | |
2110 | } | |
2111 | } | |
2112 | ||
2113 | return 0; | |
2114 | } | |
2115 | ||
2116 | static void pool_resume(struct dm_target *ti) | |
2117 | { | |
2118 | struct pool_c *pt = ti->private; | |
2119 | struct pool *pool = pt->pool; | |
2120 | unsigned long flags; | |
2121 | ||
2122 | spin_lock_irqsave(&pool->lock, flags); | |
2123 | pool->low_water_triggered = 0; | |
2124 | pool->no_free_space = 0; | |
2125 | __requeue_bios(pool); | |
2126 | spin_unlock_irqrestore(&pool->lock, flags); | |
2127 | ||
905e51b3 | 2128 | do_waker(&pool->waker.work); |
991d9fa0 JT |
2129 | } |
2130 | ||
2131 | static void pool_postsuspend(struct dm_target *ti) | |
2132 | { | |
2133 | int r; | |
2134 | struct pool_c *pt = ti->private; | |
2135 | struct pool *pool = pt->pool; | |
2136 | ||
905e51b3 | 2137 | cancel_delayed_work(&pool->waker); |
991d9fa0 JT |
2138 | flush_workqueue(pool->wq); |
2139 | ||
2140 | r = dm_pool_commit_metadata(pool->pmd); | |
2141 | if (r < 0) { | |
2142 | DMERR("%s: dm_pool_commit_metadata() failed, error = %d", | |
2143 | __func__, r); | |
2144 | /* FIXME: invalidate device? error the next FUA or FLUSH bio ?*/ | |
2145 | } | |
2146 | } | |
2147 | ||
2148 | static int check_arg_count(unsigned argc, unsigned args_required) | |
2149 | { | |
2150 | if (argc != args_required) { | |
2151 | DMWARN("Message received with %u arguments instead of %u.", | |
2152 | argc, args_required); | |
2153 | return -EINVAL; | |
2154 | } | |
2155 | ||
2156 | return 0; | |
2157 | } | |
2158 | ||
2159 | static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning) | |
2160 | { | |
2161 | if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) && | |
2162 | *dev_id <= MAX_DEV_ID) | |
2163 | return 0; | |
2164 | ||
2165 | if (warning) | |
2166 | DMWARN("Message received with invalid device id: %s", arg); | |
2167 | ||
2168 | return -EINVAL; | |
2169 | } | |
2170 | ||
2171 | static int process_create_thin_mesg(unsigned argc, char **argv, struct pool *pool) | |
2172 | { | |
2173 | dm_thin_id dev_id; | |
2174 | int r; | |
2175 | ||
2176 | r = check_arg_count(argc, 2); | |
2177 | if (r) | |
2178 | return r; | |
2179 | ||
2180 | r = read_dev_id(argv[1], &dev_id, 1); | |
2181 | if (r) | |
2182 | return r; | |
2183 | ||
2184 | r = dm_pool_create_thin(pool->pmd, dev_id); | |
2185 | if (r) { | |
2186 | DMWARN("Creation of new thinly-provisioned device with id %s failed.", | |
2187 | argv[1]); | |
2188 | return r; | |
2189 | } | |
2190 | ||
2191 | return 0; | |
2192 | } | |
2193 | ||
2194 | static int process_create_snap_mesg(unsigned argc, char **argv, struct pool *pool) | |
2195 | { | |
2196 | dm_thin_id dev_id; | |
2197 | dm_thin_id origin_dev_id; | |
2198 | int r; | |
2199 | ||
2200 | r = check_arg_count(argc, 3); | |
2201 | if (r) | |
2202 | return r; | |
2203 | ||
2204 | r = read_dev_id(argv[1], &dev_id, 1); | |
2205 | if (r) | |
2206 | return r; | |
2207 | ||
2208 | r = read_dev_id(argv[2], &origin_dev_id, 1); | |
2209 | if (r) | |
2210 | return r; | |
2211 | ||
2212 | r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id); | |
2213 | if (r) { | |
2214 | DMWARN("Creation of new snapshot %s of device %s failed.", | |
2215 | argv[1], argv[2]); | |
2216 | return r; | |
2217 | } | |
2218 | ||
2219 | return 0; | |
2220 | } | |
2221 | ||
2222 | static int process_delete_mesg(unsigned argc, char **argv, struct pool *pool) | |
2223 | { | |
2224 | dm_thin_id dev_id; | |
2225 | int r; | |
2226 | ||
2227 | r = check_arg_count(argc, 2); | |
2228 | if (r) | |
2229 | return r; | |
2230 | ||
2231 | r = read_dev_id(argv[1], &dev_id, 1); | |
2232 | if (r) | |
2233 | return r; | |
2234 | ||
2235 | r = dm_pool_delete_thin_device(pool->pmd, dev_id); | |
2236 | if (r) | |
2237 | DMWARN("Deletion of thin device %s failed.", argv[1]); | |
2238 | ||
2239 | return r; | |
2240 | } | |
2241 | ||
2242 | static int process_set_transaction_id_mesg(unsigned argc, char **argv, struct pool *pool) | |
2243 | { | |
2244 | dm_thin_id old_id, new_id; | |
2245 | int r; | |
2246 | ||
2247 | r = check_arg_count(argc, 3); | |
2248 | if (r) | |
2249 | return r; | |
2250 | ||
2251 | if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) { | |
2252 | DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]); | |
2253 | return -EINVAL; | |
2254 | } | |
2255 | ||
2256 | if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) { | |
2257 | DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]); | |
2258 | return -EINVAL; | |
2259 | } | |
2260 | ||
2261 | r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id); | |
2262 | if (r) { | |
2263 | DMWARN("Failed to change transaction id from %s to %s.", | |
2264 | argv[1], argv[2]); | |
2265 | return r; | |
2266 | } | |
2267 | ||
2268 | return 0; | |
2269 | } | |
2270 | ||
2271 | /* | |
2272 | * Messages supported: | |
2273 | * create_thin <dev_id> | |
2274 | * create_snap <dev_id> <origin_id> | |
2275 | * delete <dev_id> | |
2276 | * trim <dev_id> <new_size_in_sectors> | |
2277 | * set_transaction_id <current_trans_id> <new_trans_id> | |
2278 | */ | |
2279 | static int pool_message(struct dm_target *ti, unsigned argc, char **argv) | |
2280 | { | |
2281 | int r = -EINVAL; | |
2282 | struct pool_c *pt = ti->private; | |
2283 | struct pool *pool = pt->pool; | |
2284 | ||
2285 | if (!strcasecmp(argv[0], "create_thin")) | |
2286 | r = process_create_thin_mesg(argc, argv, pool); | |
2287 | ||
2288 | else if (!strcasecmp(argv[0], "create_snap")) | |
2289 | r = process_create_snap_mesg(argc, argv, pool); | |
2290 | ||
2291 | else if (!strcasecmp(argv[0], "delete")) | |
2292 | r = process_delete_mesg(argc, argv, pool); | |
2293 | ||
2294 | else if (!strcasecmp(argv[0], "set_transaction_id")) | |
2295 | r = process_set_transaction_id_mesg(argc, argv, pool); | |
2296 | ||
2297 | else | |
2298 | DMWARN("Unrecognised thin pool target message received: %s", argv[0]); | |
2299 | ||
2300 | if (!r) { | |
2301 | r = dm_pool_commit_metadata(pool->pmd); | |
2302 | if (r) | |
2303 | DMERR("%s message: dm_pool_commit_metadata() failed, error = %d", | |
2304 | argv[0], r); | |
2305 | } | |
2306 | ||
2307 | return r; | |
2308 | } | |
2309 | ||
2310 | /* | |
2311 | * Status line is: | |
2312 | * <transaction id> <used metadata sectors>/<total metadata sectors> | |
2313 | * <used data sectors>/<total data sectors> <held metadata root> | |
2314 | */ | |
2315 | static int pool_status(struct dm_target *ti, status_type_t type, | |
2316 | char *result, unsigned maxlen) | |
2317 | { | |
67e2e2b2 | 2318 | int r, count; |
991d9fa0 JT |
2319 | unsigned sz = 0; |
2320 | uint64_t transaction_id; | |
2321 | dm_block_t nr_free_blocks_data; | |
2322 | dm_block_t nr_free_blocks_metadata; | |
2323 | dm_block_t nr_blocks_data; | |
2324 | dm_block_t nr_blocks_metadata; | |
2325 | dm_block_t held_root; | |
2326 | char buf[BDEVNAME_SIZE]; | |
2327 | char buf2[BDEVNAME_SIZE]; | |
2328 | struct pool_c *pt = ti->private; | |
2329 | struct pool *pool = pt->pool; | |
2330 | ||
2331 | switch (type) { | |
2332 | case STATUSTYPE_INFO: | |
2333 | r = dm_pool_get_metadata_transaction_id(pool->pmd, | |
2334 | &transaction_id); | |
2335 | if (r) | |
2336 | return r; | |
2337 | ||
2338 | r = dm_pool_get_free_metadata_block_count(pool->pmd, | |
2339 | &nr_free_blocks_metadata); | |
2340 | if (r) | |
2341 | return r; | |
2342 | ||
2343 | r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata); | |
2344 | if (r) | |
2345 | return r; | |
2346 | ||
2347 | r = dm_pool_get_free_block_count(pool->pmd, | |
2348 | &nr_free_blocks_data); | |
2349 | if (r) | |
2350 | return r; | |
2351 | ||
2352 | r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data); | |
2353 | if (r) | |
2354 | return r; | |
2355 | ||
2356 | r = dm_pool_get_held_metadata_root(pool->pmd, &held_root); | |
2357 | if (r) | |
2358 | return r; | |
2359 | ||
2360 | DMEMIT("%llu %llu/%llu %llu/%llu ", | |
2361 | (unsigned long long)transaction_id, | |
2362 | (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), | |
2363 | (unsigned long long)nr_blocks_metadata, | |
2364 | (unsigned long long)(nr_blocks_data - nr_free_blocks_data), | |
2365 | (unsigned long long)nr_blocks_data); | |
2366 | ||
2367 | if (held_root) | |
2368 | DMEMIT("%llu", held_root); | |
2369 | else | |
2370 | DMEMIT("-"); | |
2371 | ||
2372 | break; | |
2373 | ||
2374 | case STATUSTYPE_TABLE: | |
2375 | DMEMIT("%s %s %lu %llu ", | |
2376 | format_dev_t(buf, pt->metadata_dev->bdev->bd_dev), | |
2377 | format_dev_t(buf2, pt->data_dev->bdev->bd_dev), | |
2378 | (unsigned long)pool->sectors_per_block, | |
2379 | (unsigned long long)pt->low_water_blocks); | |
2380 | ||
67e2e2b2 JT |
2381 | count = !pool->pf.zero_new_blocks + !pool->pf.discard_enabled + |
2382 | !pool->pf.discard_passdown; | |
2383 | DMEMIT("%u ", count); | |
991d9fa0 | 2384 | |
67e2e2b2 | 2385 | if (!pool->pf.zero_new_blocks) |
991d9fa0 | 2386 | DMEMIT("skip_block_zeroing "); |
67e2e2b2 JT |
2387 | |
2388 | if (!pool->pf.discard_enabled) | |
2389 | DMEMIT("ignore_discard "); | |
2390 | ||
2391 | if (!pool->pf.discard_passdown) | |
2392 | DMEMIT("no_discard_passdown "); | |
2393 | ||
991d9fa0 JT |
2394 | break; |
2395 | } | |
2396 | ||
2397 | return 0; | |
2398 | } | |
2399 | ||
2400 | static int pool_iterate_devices(struct dm_target *ti, | |
2401 | iterate_devices_callout_fn fn, void *data) | |
2402 | { | |
2403 | struct pool_c *pt = ti->private; | |
2404 | ||
2405 | return fn(ti, pt->data_dev, 0, ti->len, data); | |
2406 | } | |
2407 | ||
2408 | static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm, | |
2409 | struct bio_vec *biovec, int max_size) | |
2410 | { | |
2411 | struct pool_c *pt = ti->private; | |
2412 | struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); | |
2413 | ||
2414 | if (!q->merge_bvec_fn) | |
2415 | return max_size; | |
2416 | ||
2417 | bvm->bi_bdev = pt->data_dev->bdev; | |
2418 | ||
2419 | return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); | |
2420 | } | |
2421 | ||
104655fd JT |
2422 | static void set_discard_limits(struct pool *pool, struct queue_limits *limits) |
2423 | { | |
67e2e2b2 JT |
2424 | /* |
2425 | * FIXME: these limits may be incompatible with the pool's data device | |
2426 | */ | |
104655fd JT |
2427 | limits->max_discard_sectors = pool->sectors_per_block; |
2428 | ||
2429 | /* | |
2430 | * This is just a hint, and not enforced. We have to cope with | |
2431 | * bios that overlap 2 blocks. | |
2432 | */ | |
2433 | limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT; | |
67e2e2b2 | 2434 | limits->discard_zeroes_data = pool->pf.zero_new_blocks; |
104655fd JT |
2435 | } |
2436 | ||
991d9fa0 JT |
2437 | static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits) |
2438 | { | |
2439 | struct pool_c *pt = ti->private; | |
2440 | struct pool *pool = pt->pool; | |
2441 | ||
2442 | blk_limits_io_min(limits, 0); | |
2443 | blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT); | |
67e2e2b2 JT |
2444 | if (pool->pf.discard_enabled) |
2445 | set_discard_limits(pool, limits); | |
991d9fa0 JT |
2446 | } |
2447 | ||
2448 | static struct target_type pool_target = { | |
2449 | .name = "thin-pool", | |
2450 | .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE | | |
2451 | DM_TARGET_IMMUTABLE, | |
67e2e2b2 | 2452 | .version = {1, 1, 0}, |
991d9fa0 JT |
2453 | .module = THIS_MODULE, |
2454 | .ctr = pool_ctr, | |
2455 | .dtr = pool_dtr, | |
2456 | .map = pool_map, | |
2457 | .postsuspend = pool_postsuspend, | |
2458 | .preresume = pool_preresume, | |
2459 | .resume = pool_resume, | |
2460 | .message = pool_message, | |
2461 | .status = pool_status, | |
2462 | .merge = pool_merge, | |
2463 | .iterate_devices = pool_iterate_devices, | |
2464 | .io_hints = pool_io_hints, | |
2465 | }; | |
2466 | ||
2467 | /*---------------------------------------------------------------- | |
2468 | * Thin target methods | |
2469 | *--------------------------------------------------------------*/ | |
2470 | static void thin_dtr(struct dm_target *ti) | |
2471 | { | |
2472 | struct thin_c *tc = ti->private; | |
2473 | ||
2474 | mutex_lock(&dm_thin_pool_table.mutex); | |
2475 | ||
2476 | __pool_dec(tc->pool); | |
2477 | dm_pool_close_thin_device(tc->td); | |
2478 | dm_put_device(ti, tc->pool_dev); | |
2dd9c257 JT |
2479 | if (tc->origin_dev) |
2480 | dm_put_device(ti, tc->origin_dev); | |
991d9fa0 JT |
2481 | kfree(tc); |
2482 | ||
2483 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2484 | } | |
2485 | ||
2486 | /* | |
2487 | * Thin target parameters: | |
2488 | * | |
2dd9c257 | 2489 | * <pool_dev> <dev_id> [origin_dev] |
991d9fa0 JT |
2490 | * |
2491 | * pool_dev: the path to the pool (eg, /dev/mapper/my_pool) | |
2492 | * dev_id: the internal device identifier | |
2dd9c257 | 2493 | * origin_dev: a device external to the pool that should act as the origin |
67e2e2b2 JT |
2494 | * |
2495 | * If the pool device has discards disabled, they get disabled for the thin | |
2496 | * device as well. | |
991d9fa0 JT |
2497 | */ |
2498 | static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
2499 | { | |
2500 | int r; | |
2501 | struct thin_c *tc; | |
2dd9c257 | 2502 | struct dm_dev *pool_dev, *origin_dev; |
991d9fa0 JT |
2503 | struct mapped_device *pool_md; |
2504 | ||
2505 | mutex_lock(&dm_thin_pool_table.mutex); | |
2506 | ||
2dd9c257 | 2507 | if (argc != 2 && argc != 3) { |
991d9fa0 JT |
2508 | ti->error = "Invalid argument count"; |
2509 | r = -EINVAL; | |
2510 | goto out_unlock; | |
2511 | } | |
2512 | ||
2513 | tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL); | |
2514 | if (!tc) { | |
2515 | ti->error = "Out of memory"; | |
2516 | r = -ENOMEM; | |
2517 | goto out_unlock; | |
2518 | } | |
2519 | ||
2dd9c257 JT |
2520 | if (argc == 3) { |
2521 | r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev); | |
2522 | if (r) { | |
2523 | ti->error = "Error opening origin device"; | |
2524 | goto bad_origin_dev; | |
2525 | } | |
2526 | tc->origin_dev = origin_dev; | |
2527 | } | |
2528 | ||
991d9fa0 JT |
2529 | r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev); |
2530 | if (r) { | |
2531 | ti->error = "Error opening pool device"; | |
2532 | goto bad_pool_dev; | |
2533 | } | |
2534 | tc->pool_dev = pool_dev; | |
2535 | ||
2536 | if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) { | |
2537 | ti->error = "Invalid device id"; | |
2538 | r = -EINVAL; | |
2539 | goto bad_common; | |
2540 | } | |
2541 | ||
2542 | pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev); | |
2543 | if (!pool_md) { | |
2544 | ti->error = "Couldn't get pool mapped device"; | |
2545 | r = -EINVAL; | |
2546 | goto bad_common; | |
2547 | } | |
2548 | ||
2549 | tc->pool = __pool_table_lookup(pool_md); | |
2550 | if (!tc->pool) { | |
2551 | ti->error = "Couldn't find pool object"; | |
2552 | r = -EINVAL; | |
2553 | goto bad_pool_lookup; | |
2554 | } | |
2555 | __pool_inc(tc->pool); | |
2556 | ||
2557 | r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td); | |
2558 | if (r) { | |
2559 | ti->error = "Couldn't open thin internal device"; | |
2560 | goto bad_thin_open; | |
2561 | } | |
2562 | ||
2563 | ti->split_io = tc->pool->sectors_per_block; | |
2564 | ti->num_flush_requests = 1; | |
67e2e2b2 JT |
2565 | |
2566 | /* In case the pool supports discards, pass them on. */ | |
2567 | if (tc->pool->pf.discard_enabled) { | |
2568 | ti->discards_supported = 1; | |
2569 | ti->num_discard_requests = 1; | |
2570 | } | |
991d9fa0 JT |
2571 | |
2572 | dm_put(pool_md); | |
2573 | ||
2574 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2575 | ||
2576 | return 0; | |
2577 | ||
2578 | bad_thin_open: | |
2579 | __pool_dec(tc->pool); | |
2580 | bad_pool_lookup: | |
2581 | dm_put(pool_md); | |
2582 | bad_common: | |
2583 | dm_put_device(ti, tc->pool_dev); | |
2584 | bad_pool_dev: | |
2dd9c257 JT |
2585 | if (tc->origin_dev) |
2586 | dm_put_device(ti, tc->origin_dev); | |
2587 | bad_origin_dev: | |
991d9fa0 JT |
2588 | kfree(tc); |
2589 | out_unlock: | |
2590 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2591 | ||
2592 | return r; | |
2593 | } | |
2594 | ||
2595 | static int thin_map(struct dm_target *ti, struct bio *bio, | |
2596 | union map_info *map_context) | |
2597 | { | |
6efd6e83 | 2598 | bio->bi_sector = dm_target_offset(ti, bio->bi_sector); |
991d9fa0 JT |
2599 | |
2600 | return thin_bio_map(ti, bio, map_context); | |
2601 | } | |
2602 | ||
eb2aa48d JT |
2603 | static int thin_endio(struct dm_target *ti, |
2604 | struct bio *bio, int err, | |
2605 | union map_info *map_context) | |
2606 | { | |
2607 | unsigned long flags; | |
2608 | struct endio_hook *h = map_context->ptr; | |
2609 | struct list_head work; | |
2610 | struct new_mapping *m, *tmp; | |
2611 | struct pool *pool = h->tc->pool; | |
2612 | ||
2613 | if (h->shared_read_entry) { | |
2614 | INIT_LIST_HEAD(&work); | |
2615 | ds_dec(h->shared_read_entry, &work); | |
2616 | ||
2617 | spin_lock_irqsave(&pool->lock, flags); | |
2618 | list_for_each_entry_safe(m, tmp, &work, list) { | |
2619 | list_del(&m->list); | |
2620 | m->quiesced = 1; | |
2621 | __maybe_add_mapping(m); | |
2622 | } | |
2623 | spin_unlock_irqrestore(&pool->lock, flags); | |
2624 | } | |
2625 | ||
104655fd JT |
2626 | if (h->all_io_entry) { |
2627 | INIT_LIST_HEAD(&work); | |
2628 | ds_dec(h->all_io_entry, &work); | |
2629 | list_for_each_entry_safe(m, tmp, &work, list) | |
2630 | list_add(&m->list, &pool->prepared_discards); | |
2631 | } | |
2632 | ||
eb2aa48d JT |
2633 | mempool_free(h, pool->endio_hook_pool); |
2634 | ||
2635 | return 0; | |
2636 | } | |
2637 | ||
991d9fa0 JT |
2638 | static void thin_postsuspend(struct dm_target *ti) |
2639 | { | |
2640 | if (dm_noflush_suspending(ti)) | |
2641 | requeue_io((struct thin_c *)ti->private); | |
2642 | } | |
2643 | ||
2644 | /* | |
2645 | * <nr mapped sectors> <highest mapped sector> | |
2646 | */ | |
2647 | static int thin_status(struct dm_target *ti, status_type_t type, | |
2648 | char *result, unsigned maxlen) | |
2649 | { | |
2650 | int r; | |
2651 | ssize_t sz = 0; | |
2652 | dm_block_t mapped, highest; | |
2653 | char buf[BDEVNAME_SIZE]; | |
2654 | struct thin_c *tc = ti->private; | |
2655 | ||
2656 | if (!tc->td) | |
2657 | DMEMIT("-"); | |
2658 | else { | |
2659 | switch (type) { | |
2660 | case STATUSTYPE_INFO: | |
2661 | r = dm_thin_get_mapped_count(tc->td, &mapped); | |
2662 | if (r) | |
2663 | return r; | |
2664 | ||
2665 | r = dm_thin_get_highest_mapped_block(tc->td, &highest); | |
2666 | if (r < 0) | |
2667 | return r; | |
2668 | ||
2669 | DMEMIT("%llu ", mapped * tc->pool->sectors_per_block); | |
2670 | if (r) | |
2671 | DMEMIT("%llu", ((highest + 1) * | |
2672 | tc->pool->sectors_per_block) - 1); | |
2673 | else | |
2674 | DMEMIT("-"); | |
2675 | break; | |
2676 | ||
2677 | case STATUSTYPE_TABLE: | |
2678 | DMEMIT("%s %lu", | |
2679 | format_dev_t(buf, tc->pool_dev->bdev->bd_dev), | |
2680 | (unsigned long) tc->dev_id); | |
2dd9c257 JT |
2681 | if (tc->origin_dev) |
2682 | DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev)); | |
991d9fa0 JT |
2683 | break; |
2684 | } | |
2685 | } | |
2686 | ||
2687 | return 0; | |
2688 | } | |
2689 | ||
2690 | static int thin_iterate_devices(struct dm_target *ti, | |
2691 | iterate_devices_callout_fn fn, void *data) | |
2692 | { | |
2693 | dm_block_t blocks; | |
2694 | struct thin_c *tc = ti->private; | |
2695 | ||
2696 | /* | |
2697 | * We can't call dm_pool_get_data_dev_size() since that blocks. So | |
2698 | * we follow a more convoluted path through to the pool's target. | |
2699 | */ | |
2700 | if (!tc->pool->ti) | |
2701 | return 0; /* nothing is bound */ | |
2702 | ||
2703 | blocks = tc->pool->ti->len >> tc->pool->block_shift; | |
2704 | if (blocks) | |
2705 | return fn(ti, tc->pool_dev, 0, tc->pool->sectors_per_block * blocks, data); | |
2706 | ||
2707 | return 0; | |
2708 | } | |
2709 | ||
2710 | static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
2711 | { | |
2712 | struct thin_c *tc = ti->private; | |
104655fd | 2713 | struct pool *pool = tc->pool; |
991d9fa0 JT |
2714 | |
2715 | blk_limits_io_min(limits, 0); | |
104655fd JT |
2716 | blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT); |
2717 | set_discard_limits(pool, limits); | |
991d9fa0 JT |
2718 | } |
2719 | ||
2720 | static struct target_type thin_target = { | |
2721 | .name = "thin", | |
2dd9c257 | 2722 | .version = {1, 1, 0}, |
991d9fa0 JT |
2723 | .module = THIS_MODULE, |
2724 | .ctr = thin_ctr, | |
2725 | .dtr = thin_dtr, | |
2726 | .map = thin_map, | |
eb2aa48d | 2727 | .end_io = thin_endio, |
991d9fa0 JT |
2728 | .postsuspend = thin_postsuspend, |
2729 | .status = thin_status, | |
2730 | .iterate_devices = thin_iterate_devices, | |
2731 | .io_hints = thin_io_hints, | |
2732 | }; | |
2733 | ||
2734 | /*----------------------------------------------------------------*/ | |
2735 | ||
2736 | static int __init dm_thin_init(void) | |
2737 | { | |
2738 | int r; | |
2739 | ||
2740 | pool_table_init(); | |
2741 | ||
2742 | r = dm_register_target(&thin_target); | |
2743 | if (r) | |
2744 | return r; | |
2745 | ||
2746 | r = dm_register_target(&pool_target); | |
2747 | if (r) | |
2748 | dm_unregister_target(&thin_target); | |
2749 | ||
2750 | return r; | |
2751 | } | |
2752 | ||
2753 | static void dm_thin_exit(void) | |
2754 | { | |
2755 | dm_unregister_target(&thin_target); | |
2756 | dm_unregister_target(&pool_target); | |
2757 | } | |
2758 | ||
2759 | module_init(dm_thin_init); | |
2760 | module_exit(dm_thin_exit); | |
2761 | ||
2762 | MODULE_DESCRIPTION(DM_NAME "device-mapper thin provisioning target"); | |
2763 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); | |
2764 | MODULE_LICENSE("GPL"); |