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