Commit | Line | Data |
---|---|---|
991d9fa0 | 1 | /* |
e49e5829 | 2 | * Copyright (C) 2011-2012 Red Hat UK. |
991d9fa0 JT |
3 | * |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7 | #include "dm-thin-metadata.h" | |
1f4e0ff0 | 8 | #include "dm.h" |
991d9fa0 JT |
9 | |
10 | #include <linux/device-mapper.h> | |
11 | #include <linux/dm-io.h> | |
12 | #include <linux/dm-kcopyd.h> | |
13 | #include <linux/list.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/slab.h> | |
17 | ||
18 | #define DM_MSG_PREFIX "thin" | |
19 | ||
20 | /* | |
21 | * Tunable constants | |
22 | */ | |
7768ed33 | 23 | #define ENDIO_HOOK_POOL_SIZE 1024 |
991d9fa0 JT |
24 | #define DEFERRED_SET_SIZE 64 |
25 | #define MAPPING_POOL_SIZE 1024 | |
26 | #define PRISON_CELLS 1024 | |
905e51b3 | 27 | #define COMMIT_PERIOD HZ |
991d9fa0 JT |
28 | |
29 | /* | |
30 | * The block size of the device holding pool data must be | |
31 | * between 64KB and 1GB. | |
32 | */ | |
33 | #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT) | |
34 | #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT) | |
35 | ||
991d9fa0 JT |
36 | /* |
37 | * Device id is restricted to 24 bits. | |
38 | */ | |
39 | #define MAX_DEV_ID ((1 << 24) - 1) | |
40 | ||
41 | /* | |
42 | * How do we handle breaking sharing of data blocks? | |
43 | * ================================================= | |
44 | * | |
45 | * We use a standard copy-on-write btree to store the mappings for the | |
46 | * devices (note I'm talking about copy-on-write of the metadata here, not | |
47 | * the data). When you take an internal snapshot you clone the root node | |
48 | * of the origin btree. After this there is no concept of an origin or a | |
49 | * snapshot. They are just two device trees that happen to point to the | |
50 | * same data blocks. | |
51 | * | |
52 | * When we get a write in we decide if it's to a shared data block using | |
53 | * some timestamp magic. If it is, we have to break sharing. | |
54 | * | |
55 | * Let's say we write to a shared block in what was the origin. The | |
56 | * steps are: | |
57 | * | |
58 | * i) plug io further to this physical block. (see bio_prison code). | |
59 | * | |
60 | * ii) quiesce any read io to that shared data block. Obviously | |
61 | * including all devices that share this block. (see deferred_set code) | |
62 | * | |
63 | * iii) copy the data block to a newly allocate block. This step can be | |
64 | * missed out if the io covers the block. (schedule_copy). | |
65 | * | |
66 | * iv) insert the new mapping into the origin's btree | |
fe878f34 | 67 | * (process_prepared_mapping). This act of inserting breaks some |
991d9fa0 JT |
68 | * sharing of btree nodes between the two devices. Breaking sharing only |
69 | * effects the btree of that specific device. Btrees for the other | |
70 | * devices that share the block never change. The btree for the origin | |
71 | * device as it was after the last commit is untouched, ie. we're using | |
72 | * persistent data structures in the functional programming sense. | |
73 | * | |
74 | * v) unplug io to this physical block, including the io that triggered | |
75 | * the breaking of sharing. | |
76 | * | |
77 | * Steps (ii) and (iii) occur in parallel. | |
78 | * | |
79 | * The metadata _doesn't_ need to be committed before the io continues. We | |
80 | * get away with this because the io is always written to a _new_ block. | |
81 | * If there's a crash, then: | |
82 | * | |
83 | * - The origin mapping will point to the old origin block (the shared | |
84 | * one). This will contain the data as it was before the io that triggered | |
85 | * the breaking of sharing came in. | |
86 | * | |
87 | * - The snap mapping still points to the old block. As it would after | |
88 | * the commit. | |
89 | * | |
90 | * The downside of this scheme is the timestamp magic isn't perfect, and | |
91 | * will continue to think that data block in the snapshot device is shared | |
92 | * even after the write to the origin has broken sharing. I suspect data | |
93 | * blocks will typically be shared by many different devices, so we're | |
94 | * breaking sharing n + 1 times, rather than n, where n is the number of | |
95 | * devices that reference this data block. At the moment I think the | |
96 | * benefits far, far outweigh the disadvantages. | |
97 | */ | |
98 | ||
99 | /*----------------------------------------------------------------*/ | |
100 | ||
101 | /* | |
102 | * Sometimes we can't deal with a bio straight away. We put them in prison | |
103 | * where they can't cause any mischief. Bios are put in a cell identified | |
104 | * by a key, multiple bios can be in the same cell. When the cell is | |
105 | * subsequently unlocked the bios become available. | |
106 | */ | |
107 | struct bio_prison; | |
108 | ||
109 | struct cell_key { | |
110 | int virtual; | |
111 | dm_thin_id dev; | |
112 | dm_block_t block; | |
113 | }; | |
114 | ||
a24c2569 | 115 | struct dm_bio_prison_cell { |
991d9fa0 JT |
116 | struct hlist_node list; |
117 | struct bio_prison *prison; | |
118 | struct cell_key key; | |
6f94a4c4 | 119 | struct bio *holder; |
991d9fa0 JT |
120 | struct bio_list bios; |
121 | }; | |
122 | ||
123 | struct bio_prison { | |
124 | spinlock_t lock; | |
125 | mempool_t *cell_pool; | |
126 | ||
127 | unsigned nr_buckets; | |
128 | unsigned hash_mask; | |
129 | struct hlist_head *cells; | |
130 | }; | |
131 | ||
132 | static uint32_t calc_nr_buckets(unsigned nr_cells) | |
133 | { | |
134 | uint32_t n = 128; | |
135 | ||
136 | nr_cells /= 4; | |
137 | nr_cells = min(nr_cells, 8192u); | |
138 | ||
139 | while (n < nr_cells) | |
140 | n <<= 1; | |
141 | ||
142 | return n; | |
143 | } | |
144 | ||
a24c2569 MS |
145 | static struct kmem_cache *_cell_cache; |
146 | ||
991d9fa0 JT |
147 | /* |
148 | * @nr_cells should be the number of cells you want in use _concurrently_. | |
149 | * Don't confuse it with the number of distinct keys. | |
150 | */ | |
151 | static struct bio_prison *prison_create(unsigned nr_cells) | |
152 | { | |
153 | unsigned i; | |
154 | uint32_t nr_buckets = calc_nr_buckets(nr_cells); | |
155 | size_t len = sizeof(struct bio_prison) + | |
156 | (sizeof(struct hlist_head) * nr_buckets); | |
157 | struct bio_prison *prison = kmalloc(len, GFP_KERNEL); | |
158 | ||
159 | if (!prison) | |
160 | return NULL; | |
161 | ||
162 | spin_lock_init(&prison->lock); | |
a24c2569 | 163 | prison->cell_pool = mempool_create_slab_pool(nr_cells, _cell_cache); |
991d9fa0 JT |
164 | if (!prison->cell_pool) { |
165 | kfree(prison); | |
166 | return NULL; | |
167 | } | |
168 | ||
169 | prison->nr_buckets = nr_buckets; | |
170 | prison->hash_mask = nr_buckets - 1; | |
171 | prison->cells = (struct hlist_head *) (prison + 1); | |
172 | for (i = 0; i < nr_buckets; i++) | |
173 | INIT_HLIST_HEAD(prison->cells + i); | |
174 | ||
175 | return prison; | |
176 | } | |
177 | ||
178 | static void prison_destroy(struct bio_prison *prison) | |
179 | { | |
180 | mempool_destroy(prison->cell_pool); | |
181 | kfree(prison); | |
182 | } | |
183 | ||
184 | static uint32_t hash_key(struct bio_prison *prison, struct cell_key *key) | |
185 | { | |
186 | const unsigned long BIG_PRIME = 4294967291UL; | |
187 | uint64_t hash = key->block * BIG_PRIME; | |
188 | ||
189 | return (uint32_t) (hash & prison->hash_mask); | |
190 | } | |
191 | ||
192 | static int keys_equal(struct cell_key *lhs, struct cell_key *rhs) | |
193 | { | |
194 | return (lhs->virtual == rhs->virtual) && | |
195 | (lhs->dev == rhs->dev) && | |
196 | (lhs->block == rhs->block); | |
197 | } | |
198 | ||
a24c2569 MS |
199 | static struct dm_bio_prison_cell *__search_bucket(struct hlist_head *bucket, |
200 | struct cell_key *key) | |
991d9fa0 | 201 | { |
a24c2569 | 202 | struct dm_bio_prison_cell *cell; |
991d9fa0 JT |
203 | struct hlist_node *tmp; |
204 | ||
205 | hlist_for_each_entry(cell, tmp, bucket, list) | |
206 | if (keys_equal(&cell->key, key)) | |
207 | return cell; | |
208 | ||
209 | return NULL; | |
210 | } | |
211 | ||
212 | /* | |
213 | * This may block if a new cell needs allocating. You must ensure that | |
214 | * cells will be unlocked even if the calling thread is blocked. | |
215 | * | |
6f94a4c4 | 216 | * Returns 1 if the cell was already held, 0 if @inmate is the new holder. |
991d9fa0 JT |
217 | */ |
218 | static int bio_detain(struct bio_prison *prison, struct cell_key *key, | |
a24c2569 | 219 | struct bio *inmate, struct dm_bio_prison_cell **ref) |
991d9fa0 | 220 | { |
6f94a4c4 | 221 | int r = 1; |
991d9fa0 JT |
222 | unsigned long flags; |
223 | uint32_t hash = hash_key(prison, key); | |
a24c2569 | 224 | struct dm_bio_prison_cell *cell, *cell2; |
991d9fa0 JT |
225 | |
226 | BUG_ON(hash > prison->nr_buckets); | |
227 | ||
228 | spin_lock_irqsave(&prison->lock, flags); | |
991d9fa0 | 229 | |
6f94a4c4 JT |
230 | cell = __search_bucket(prison->cells + hash, key); |
231 | if (cell) { | |
232 | bio_list_add(&cell->bios, inmate); | |
233 | goto out; | |
991d9fa0 JT |
234 | } |
235 | ||
6f94a4c4 JT |
236 | /* |
237 | * Allocate a new cell | |
238 | */ | |
991d9fa0 | 239 | spin_unlock_irqrestore(&prison->lock, flags); |
6f94a4c4 JT |
240 | cell2 = mempool_alloc(prison->cell_pool, GFP_NOIO); |
241 | spin_lock_irqsave(&prison->lock, flags); | |
991d9fa0 | 242 | |
6f94a4c4 JT |
243 | /* |
244 | * We've been unlocked, so we have to double check that | |
245 | * nobody else has inserted this cell in the meantime. | |
246 | */ | |
247 | cell = __search_bucket(prison->cells + hash, key); | |
248 | if (cell) { | |
991d9fa0 | 249 | mempool_free(cell2, prison->cell_pool); |
6f94a4c4 JT |
250 | bio_list_add(&cell->bios, inmate); |
251 | goto out; | |
252 | } | |
253 | ||
254 | /* | |
255 | * Use new cell. | |
256 | */ | |
257 | cell = cell2; | |
258 | ||
259 | cell->prison = prison; | |
260 | memcpy(&cell->key, key, sizeof(cell->key)); | |
261 | cell->holder = inmate; | |
262 | bio_list_init(&cell->bios); | |
263 | hlist_add_head(&cell->list, prison->cells + hash); | |
264 | ||
265 | r = 0; | |
266 | ||
267 | out: | |
268 | spin_unlock_irqrestore(&prison->lock, flags); | |
991d9fa0 JT |
269 | |
270 | *ref = cell; | |
271 | ||
272 | return r; | |
273 | } | |
274 | ||
275 | /* | |
276 | * @inmates must have been initialised prior to this call | |
277 | */ | |
a24c2569 | 278 | static void __cell_release(struct dm_bio_prison_cell *cell, struct bio_list *inmates) |
991d9fa0 JT |
279 | { |
280 | struct bio_prison *prison = cell->prison; | |
281 | ||
282 | hlist_del(&cell->list); | |
283 | ||
03aaae7c MS |
284 | if (inmates) { |
285 | bio_list_add(inmates, cell->holder); | |
286 | bio_list_merge(inmates, &cell->bios); | |
287 | } | |
991d9fa0 JT |
288 | |
289 | mempool_free(cell, prison->cell_pool); | |
290 | } | |
291 | ||
a24c2569 | 292 | static void cell_release(struct dm_bio_prison_cell *cell, struct bio_list *bios) |
991d9fa0 JT |
293 | { |
294 | unsigned long flags; | |
295 | struct bio_prison *prison = cell->prison; | |
296 | ||
297 | spin_lock_irqsave(&prison->lock, flags); | |
298 | __cell_release(cell, bios); | |
299 | spin_unlock_irqrestore(&prison->lock, flags); | |
300 | } | |
301 | ||
302 | /* | |
303 | * There are a couple of places where we put a bio into a cell briefly | |
304 | * before taking it out again. In these situations we know that no other | |
305 | * bio may be in the cell. This function releases the cell, and also does | |
306 | * a sanity check. | |
307 | */ | |
a24c2569 | 308 | static void __cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio) |
6f94a4c4 | 309 | { |
6f94a4c4 JT |
310 | BUG_ON(cell->holder != bio); |
311 | BUG_ON(!bio_list_empty(&cell->bios)); | |
03aaae7c MS |
312 | |
313 | __cell_release(cell, NULL); | |
6f94a4c4 JT |
314 | } |
315 | ||
a24c2569 | 316 | static void cell_release_singleton(struct dm_bio_prison_cell *cell, struct bio *bio) |
991d9fa0 | 317 | { |
991d9fa0 | 318 | unsigned long flags; |
6f94a4c4 | 319 | struct bio_prison *prison = cell->prison; |
991d9fa0 JT |
320 | |
321 | spin_lock_irqsave(&prison->lock, flags); | |
6f94a4c4 | 322 | __cell_release_singleton(cell, bio); |
991d9fa0 | 323 | spin_unlock_irqrestore(&prison->lock, flags); |
6f94a4c4 JT |
324 | } |
325 | ||
326 | /* | |
327 | * Sometimes we don't want the holder, just the additional bios. | |
328 | */ | |
a24c2569 MS |
329 | static void __cell_release_no_holder(struct dm_bio_prison_cell *cell, |
330 | struct bio_list *inmates) | |
6f94a4c4 JT |
331 | { |
332 | struct bio_prison *prison = cell->prison; | |
333 | ||
334 | hlist_del(&cell->list); | |
335 | bio_list_merge(inmates, &cell->bios); | |
336 | ||
337 | mempool_free(cell, prison->cell_pool); | |
338 | } | |
339 | ||
a24c2569 MS |
340 | static void cell_release_no_holder(struct dm_bio_prison_cell *cell, |
341 | struct bio_list *inmates) | |
6f94a4c4 JT |
342 | { |
343 | unsigned long flags; | |
344 | struct bio_prison *prison = cell->prison; | |
991d9fa0 | 345 | |
6f94a4c4 JT |
346 | spin_lock_irqsave(&prison->lock, flags); |
347 | __cell_release_no_holder(cell, inmates); | |
348 | spin_unlock_irqrestore(&prison->lock, flags); | |
991d9fa0 JT |
349 | } |
350 | ||
a24c2569 | 351 | static void cell_error(struct dm_bio_prison_cell *cell) |
991d9fa0 JT |
352 | { |
353 | struct bio_prison *prison = cell->prison; | |
354 | struct bio_list bios; | |
355 | struct bio *bio; | |
356 | unsigned long flags; | |
357 | ||
358 | bio_list_init(&bios); | |
359 | ||
360 | spin_lock_irqsave(&prison->lock, flags); | |
361 | __cell_release(cell, &bios); | |
362 | spin_unlock_irqrestore(&prison->lock, flags); | |
363 | ||
364 | while ((bio = bio_list_pop(&bios))) | |
365 | bio_io_error(bio); | |
366 | } | |
367 | ||
368 | /*----------------------------------------------------------------*/ | |
369 | ||
370 | /* | |
371 | * We use the deferred set to keep track of pending reads to shared blocks. | |
372 | * We do this to ensure the new mapping caused by a write isn't performed | |
373 | * until these prior reads have completed. Otherwise the insertion of the | |
374 | * new mapping could free the old block that the read bios are mapped to. | |
375 | */ | |
376 | ||
377 | struct deferred_set; | |
378 | struct deferred_entry { | |
379 | struct deferred_set *ds; | |
380 | unsigned count; | |
381 | struct list_head work_items; | |
382 | }; | |
383 | ||
384 | struct deferred_set { | |
385 | spinlock_t lock; | |
386 | unsigned current_entry; | |
387 | unsigned sweeper; | |
388 | struct deferred_entry entries[DEFERRED_SET_SIZE]; | |
389 | }; | |
390 | ||
391 | static void ds_init(struct deferred_set *ds) | |
392 | { | |
393 | int i; | |
394 | ||
395 | spin_lock_init(&ds->lock); | |
396 | ds->current_entry = 0; | |
397 | ds->sweeper = 0; | |
398 | for (i = 0; i < DEFERRED_SET_SIZE; i++) { | |
399 | ds->entries[i].ds = ds; | |
400 | ds->entries[i].count = 0; | |
401 | INIT_LIST_HEAD(&ds->entries[i].work_items); | |
402 | } | |
403 | } | |
404 | ||
405 | static struct deferred_entry *ds_inc(struct deferred_set *ds) | |
406 | { | |
407 | unsigned long flags; | |
408 | struct deferred_entry *entry; | |
409 | ||
410 | spin_lock_irqsave(&ds->lock, flags); | |
411 | entry = ds->entries + ds->current_entry; | |
412 | entry->count++; | |
413 | spin_unlock_irqrestore(&ds->lock, flags); | |
414 | ||
415 | return entry; | |
416 | } | |
417 | ||
418 | static unsigned ds_next(unsigned index) | |
419 | { | |
420 | return (index + 1) % DEFERRED_SET_SIZE; | |
421 | } | |
422 | ||
423 | static void __sweep(struct deferred_set *ds, struct list_head *head) | |
424 | { | |
425 | while ((ds->sweeper != ds->current_entry) && | |
426 | !ds->entries[ds->sweeper].count) { | |
427 | list_splice_init(&ds->entries[ds->sweeper].work_items, head); | |
428 | ds->sweeper = ds_next(ds->sweeper); | |
429 | } | |
430 | ||
431 | if ((ds->sweeper == ds->current_entry) && !ds->entries[ds->sweeper].count) | |
432 | list_splice_init(&ds->entries[ds->sweeper].work_items, head); | |
433 | } | |
434 | ||
435 | static void ds_dec(struct deferred_entry *entry, struct list_head *head) | |
436 | { | |
437 | unsigned long flags; | |
438 | ||
439 | spin_lock_irqsave(&entry->ds->lock, flags); | |
440 | BUG_ON(!entry->count); | |
441 | --entry->count; | |
442 | __sweep(entry->ds, head); | |
443 | spin_unlock_irqrestore(&entry->ds->lock, flags); | |
444 | } | |
445 | ||
446 | /* | |
447 | * Returns 1 if deferred or 0 if no pending items to delay job. | |
448 | */ | |
449 | static int ds_add_work(struct deferred_set *ds, struct list_head *work) | |
450 | { | |
451 | int r = 1; | |
452 | unsigned long flags; | |
453 | unsigned next_entry; | |
454 | ||
455 | spin_lock_irqsave(&ds->lock, flags); | |
456 | if ((ds->sweeper == ds->current_entry) && | |
457 | !ds->entries[ds->current_entry].count) | |
458 | r = 0; | |
459 | else { | |
460 | list_add(work, &ds->entries[ds->current_entry].work_items); | |
461 | next_entry = ds_next(ds->current_entry); | |
462 | if (!ds->entries[next_entry].count) | |
463 | ds->current_entry = next_entry; | |
464 | } | |
465 | spin_unlock_irqrestore(&ds->lock, flags); | |
466 | ||
467 | return r; | |
468 | } | |
469 | ||
470 | /*----------------------------------------------------------------*/ | |
471 | ||
472 | /* | |
473 | * Key building. | |
474 | */ | |
475 | static void build_data_key(struct dm_thin_device *td, | |
476 | dm_block_t b, struct cell_key *key) | |
477 | { | |
478 | key->virtual = 0; | |
479 | key->dev = dm_thin_dev_id(td); | |
480 | key->block = b; | |
481 | } | |
482 | ||
483 | static void build_virtual_key(struct dm_thin_device *td, dm_block_t b, | |
484 | struct cell_key *key) | |
485 | { | |
486 | key->virtual = 1; | |
487 | key->dev = dm_thin_dev_id(td); | |
488 | key->block = b; | |
489 | } | |
490 | ||
491 | /*----------------------------------------------------------------*/ | |
492 | ||
493 | /* | |
494 | * A pool device ties together a metadata device and a data device. It | |
495 | * also provides the interface for creating and destroying internal | |
496 | * devices. | |
497 | */ | |
a24c2569 | 498 | struct dm_thin_new_mapping; |
67e2e2b2 | 499 | |
e49e5829 JT |
500 | /* |
501 | * The pool runs in 3 modes. Ordered in degraded order for comparisons. | |
502 | */ | |
503 | enum pool_mode { | |
504 | PM_WRITE, /* metadata may be changed */ | |
505 | PM_READ_ONLY, /* metadata may not be changed */ | |
506 | PM_FAIL, /* all I/O fails */ | |
507 | }; | |
508 | ||
67e2e2b2 | 509 | struct pool_features { |
e49e5829 JT |
510 | enum pool_mode mode; |
511 | ||
9bc142dd MS |
512 | bool zero_new_blocks:1; |
513 | bool discard_enabled:1; | |
514 | bool discard_passdown:1; | |
67e2e2b2 JT |
515 | }; |
516 | ||
e49e5829 JT |
517 | struct thin_c; |
518 | typedef void (*process_bio_fn)(struct thin_c *tc, struct bio *bio); | |
519 | typedef void (*process_mapping_fn)(struct dm_thin_new_mapping *m); | |
520 | ||
991d9fa0 JT |
521 | struct pool { |
522 | struct list_head list; | |
523 | struct dm_target *ti; /* Only set if a pool target is bound */ | |
524 | ||
525 | struct mapped_device *pool_md; | |
526 | struct block_device *md_dev; | |
527 | struct dm_pool_metadata *pmd; | |
528 | ||
991d9fa0 | 529 | dm_block_t low_water_blocks; |
55f2b8bd | 530 | uint32_t sectors_per_block; |
f9a8e0cd | 531 | int sectors_per_block_shift; |
991d9fa0 | 532 | |
67e2e2b2 | 533 | struct pool_features pf; |
991d9fa0 JT |
534 | unsigned low_water_triggered:1; /* A dm event has been sent */ |
535 | unsigned no_free_space:1; /* A -ENOSPC warning has been issued */ | |
536 | ||
537 | struct bio_prison *prison; | |
538 | struct dm_kcopyd_client *copier; | |
539 | ||
540 | struct workqueue_struct *wq; | |
541 | struct work_struct worker; | |
905e51b3 | 542 | struct delayed_work waker; |
991d9fa0 | 543 | |
905e51b3 | 544 | unsigned long last_commit_jiffies; |
55f2b8bd | 545 | unsigned ref_count; |
991d9fa0 JT |
546 | |
547 | spinlock_t lock; | |
548 | struct bio_list deferred_bios; | |
549 | struct bio_list deferred_flush_bios; | |
550 | struct list_head prepared_mappings; | |
104655fd | 551 | struct list_head prepared_discards; |
991d9fa0 JT |
552 | |
553 | struct bio_list retry_on_resume_list; | |
554 | ||
eb2aa48d | 555 | struct deferred_set shared_read_ds; |
104655fd | 556 | struct deferred_set all_io_ds; |
991d9fa0 | 557 | |
a24c2569 | 558 | struct dm_thin_new_mapping *next_mapping; |
991d9fa0 JT |
559 | mempool_t *mapping_pool; |
560 | mempool_t *endio_hook_pool; | |
e49e5829 JT |
561 | |
562 | process_bio_fn process_bio; | |
563 | process_bio_fn process_discard; | |
564 | ||
565 | process_mapping_fn process_prepared_mapping; | |
566 | process_mapping_fn process_prepared_discard; | |
991d9fa0 JT |
567 | }; |
568 | ||
e49e5829 JT |
569 | static enum pool_mode get_pool_mode(struct pool *pool); |
570 | static void set_pool_mode(struct pool *pool, enum pool_mode mode); | |
571 | ||
991d9fa0 JT |
572 | /* |
573 | * Target context for a pool. | |
574 | */ | |
575 | struct pool_c { | |
576 | struct dm_target *ti; | |
577 | struct pool *pool; | |
578 | struct dm_dev *data_dev; | |
579 | struct dm_dev *metadata_dev; | |
580 | struct dm_target_callbacks callbacks; | |
581 | ||
582 | dm_block_t low_water_blocks; | |
0424caa1 MS |
583 | struct pool_features requested_pf; /* Features requested during table load */ |
584 | struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */ | |
991d9fa0 JT |
585 | }; |
586 | ||
587 | /* | |
588 | * Target context for a thin. | |
589 | */ | |
590 | struct thin_c { | |
591 | struct dm_dev *pool_dev; | |
2dd9c257 | 592 | struct dm_dev *origin_dev; |
991d9fa0 JT |
593 | dm_thin_id dev_id; |
594 | ||
595 | struct pool *pool; | |
596 | struct dm_thin_device *td; | |
597 | }; | |
598 | ||
599 | /*----------------------------------------------------------------*/ | |
600 | ||
601 | /* | |
602 | * A global list of pools that uses a struct mapped_device as a key. | |
603 | */ | |
604 | static struct dm_thin_pool_table { | |
605 | struct mutex mutex; | |
606 | struct list_head pools; | |
607 | } dm_thin_pool_table; | |
608 | ||
609 | static void pool_table_init(void) | |
610 | { | |
611 | mutex_init(&dm_thin_pool_table.mutex); | |
612 | INIT_LIST_HEAD(&dm_thin_pool_table.pools); | |
613 | } | |
614 | ||
615 | static void __pool_table_insert(struct pool *pool) | |
616 | { | |
617 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
618 | list_add(&pool->list, &dm_thin_pool_table.pools); | |
619 | } | |
620 | ||
621 | static void __pool_table_remove(struct pool *pool) | |
622 | { | |
623 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
624 | list_del(&pool->list); | |
625 | } | |
626 | ||
627 | static struct pool *__pool_table_lookup(struct mapped_device *md) | |
628 | { | |
629 | struct pool *pool = NULL, *tmp; | |
630 | ||
631 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
632 | ||
633 | list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) { | |
634 | if (tmp->pool_md == md) { | |
635 | pool = tmp; | |
636 | break; | |
637 | } | |
638 | } | |
639 | ||
640 | return pool; | |
641 | } | |
642 | ||
643 | static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev) | |
644 | { | |
645 | struct pool *pool = NULL, *tmp; | |
646 | ||
647 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
648 | ||
649 | list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) { | |
650 | if (tmp->md_dev == md_dev) { | |
651 | pool = tmp; | |
652 | break; | |
653 | } | |
654 | } | |
655 | ||
656 | return pool; | |
657 | } | |
658 | ||
659 | /*----------------------------------------------------------------*/ | |
660 | ||
a24c2569 | 661 | struct dm_thin_endio_hook { |
eb2aa48d JT |
662 | struct thin_c *tc; |
663 | struct deferred_entry *shared_read_entry; | |
104655fd | 664 | struct deferred_entry *all_io_entry; |
a24c2569 | 665 | struct dm_thin_new_mapping *overwrite_mapping; |
eb2aa48d JT |
666 | }; |
667 | ||
991d9fa0 JT |
668 | static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master) |
669 | { | |
670 | struct bio *bio; | |
671 | struct bio_list bios; | |
672 | ||
673 | bio_list_init(&bios); | |
674 | bio_list_merge(&bios, master); | |
675 | bio_list_init(master); | |
676 | ||
677 | while ((bio = bio_list_pop(&bios))) { | |
a24c2569 MS |
678 | struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr; |
679 | ||
eb2aa48d | 680 | if (h->tc == tc) |
991d9fa0 JT |
681 | bio_endio(bio, DM_ENDIO_REQUEUE); |
682 | else | |
683 | bio_list_add(master, bio); | |
684 | } | |
685 | } | |
686 | ||
687 | static void requeue_io(struct thin_c *tc) | |
688 | { | |
689 | struct pool *pool = tc->pool; | |
690 | unsigned long flags; | |
691 | ||
692 | spin_lock_irqsave(&pool->lock, flags); | |
693 | __requeue_bio_list(tc, &pool->deferred_bios); | |
694 | __requeue_bio_list(tc, &pool->retry_on_resume_list); | |
695 | spin_unlock_irqrestore(&pool->lock, flags); | |
696 | } | |
697 | ||
698 | /* | |
699 | * This section of code contains the logic for processing a thin device's IO. | |
700 | * Much of the code depends on pool object resources (lists, workqueues, etc) | |
701 | * but most is exclusively called from the thin target rather than the thin-pool | |
702 | * target. | |
703 | */ | |
704 | ||
705 | static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio) | |
706 | { | |
55f2b8bd MS |
707 | sector_t block_nr = bio->bi_sector; |
708 | ||
f9a8e0cd MP |
709 | if (tc->pool->sectors_per_block_shift < 0) |
710 | (void) sector_div(block_nr, tc->pool->sectors_per_block); | |
711 | else | |
712 | block_nr >>= tc->pool->sectors_per_block_shift; | |
55f2b8bd MS |
713 | |
714 | return block_nr; | |
991d9fa0 JT |
715 | } |
716 | ||
717 | static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block) | |
718 | { | |
719 | struct pool *pool = tc->pool; | |
55f2b8bd | 720 | sector_t bi_sector = bio->bi_sector; |
991d9fa0 JT |
721 | |
722 | bio->bi_bdev = tc->pool_dev->bdev; | |
f9a8e0cd MP |
723 | if (tc->pool->sectors_per_block_shift < 0) |
724 | bio->bi_sector = (block * pool->sectors_per_block) + | |
725 | sector_div(bi_sector, pool->sectors_per_block); | |
726 | else | |
727 | bio->bi_sector = (block << pool->sectors_per_block_shift) | | |
728 | (bi_sector & (pool->sectors_per_block - 1)); | |
991d9fa0 JT |
729 | } |
730 | ||
2dd9c257 JT |
731 | static void remap_to_origin(struct thin_c *tc, struct bio *bio) |
732 | { | |
733 | bio->bi_bdev = tc->origin_dev->bdev; | |
734 | } | |
735 | ||
4afdd680 JT |
736 | static int bio_triggers_commit(struct thin_c *tc, struct bio *bio) |
737 | { | |
738 | return (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && | |
739 | dm_thin_changed_this_transaction(tc->td); | |
740 | } | |
741 | ||
2dd9c257 | 742 | static void issue(struct thin_c *tc, struct bio *bio) |
991d9fa0 JT |
743 | { |
744 | struct pool *pool = tc->pool; | |
745 | unsigned long flags; | |
746 | ||
e49e5829 JT |
747 | if (!bio_triggers_commit(tc, bio)) { |
748 | generic_make_request(bio); | |
749 | return; | |
750 | } | |
751 | ||
991d9fa0 | 752 | /* |
e49e5829 JT |
753 | * Complete bio with an error if earlier I/O caused changes to |
754 | * the metadata that can't be committed e.g, due to I/O errors | |
755 | * on the metadata device. | |
991d9fa0 | 756 | */ |
e49e5829 JT |
757 | if (dm_thin_aborted_changes(tc->td)) { |
758 | bio_io_error(bio); | |
759 | return; | |
760 | } | |
761 | ||
762 | /* | |
763 | * Batch together any bios that trigger commits and then issue a | |
764 | * single commit for them in process_deferred_bios(). | |
765 | */ | |
766 | spin_lock_irqsave(&pool->lock, flags); | |
767 | bio_list_add(&pool->deferred_flush_bios, bio); | |
768 | spin_unlock_irqrestore(&pool->lock, flags); | |
991d9fa0 JT |
769 | } |
770 | ||
2dd9c257 JT |
771 | static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio) |
772 | { | |
773 | remap_to_origin(tc, bio); | |
774 | issue(tc, bio); | |
775 | } | |
776 | ||
777 | static void remap_and_issue(struct thin_c *tc, struct bio *bio, | |
778 | dm_block_t block) | |
779 | { | |
780 | remap(tc, bio, block); | |
781 | issue(tc, bio); | |
782 | } | |
783 | ||
991d9fa0 JT |
784 | /* |
785 | * wake_worker() is used when new work is queued and when pool_resume is | |
786 | * ready to continue deferred IO processing. | |
787 | */ | |
788 | static void wake_worker(struct pool *pool) | |
789 | { | |
790 | queue_work(pool->wq, &pool->worker); | |
791 | } | |
792 | ||
793 | /*----------------------------------------------------------------*/ | |
794 | ||
795 | /* | |
796 | * Bio endio functions. | |
797 | */ | |
a24c2569 | 798 | struct dm_thin_new_mapping { |
991d9fa0 JT |
799 | struct list_head list; |
800 | ||
eb2aa48d JT |
801 | unsigned quiesced:1; |
802 | unsigned prepared:1; | |
104655fd | 803 | unsigned pass_discard:1; |
991d9fa0 JT |
804 | |
805 | struct thin_c *tc; | |
806 | dm_block_t virt_block; | |
807 | dm_block_t data_block; | |
a24c2569 | 808 | struct dm_bio_prison_cell *cell, *cell2; |
991d9fa0 JT |
809 | int err; |
810 | ||
811 | /* | |
812 | * If the bio covers the whole area of a block then we can avoid | |
813 | * zeroing or copying. Instead this bio is hooked. The bio will | |
814 | * still be in the cell, so care has to be taken to avoid issuing | |
815 | * the bio twice. | |
816 | */ | |
817 | struct bio *bio; | |
818 | bio_end_io_t *saved_bi_end_io; | |
819 | }; | |
820 | ||
a24c2569 | 821 | static void __maybe_add_mapping(struct dm_thin_new_mapping *m) |
991d9fa0 JT |
822 | { |
823 | struct pool *pool = m->tc->pool; | |
824 | ||
eb2aa48d | 825 | if (m->quiesced && m->prepared) { |
991d9fa0 JT |
826 | list_add(&m->list, &pool->prepared_mappings); |
827 | wake_worker(pool); | |
828 | } | |
829 | } | |
830 | ||
831 | static void copy_complete(int read_err, unsigned long write_err, void *context) | |
832 | { | |
833 | unsigned long flags; | |
a24c2569 | 834 | struct dm_thin_new_mapping *m = context; |
991d9fa0 JT |
835 | struct pool *pool = m->tc->pool; |
836 | ||
837 | m->err = read_err || write_err ? -EIO : 0; | |
838 | ||
839 | spin_lock_irqsave(&pool->lock, flags); | |
840 | m->prepared = 1; | |
841 | __maybe_add_mapping(m); | |
842 | spin_unlock_irqrestore(&pool->lock, flags); | |
843 | } | |
844 | ||
845 | static void overwrite_endio(struct bio *bio, int err) | |
846 | { | |
847 | unsigned long flags; | |
a24c2569 MS |
848 | struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr; |
849 | struct dm_thin_new_mapping *m = h->overwrite_mapping; | |
991d9fa0 JT |
850 | struct pool *pool = m->tc->pool; |
851 | ||
852 | m->err = err; | |
853 | ||
854 | spin_lock_irqsave(&pool->lock, flags); | |
855 | m->prepared = 1; | |
856 | __maybe_add_mapping(m); | |
857 | spin_unlock_irqrestore(&pool->lock, flags); | |
858 | } | |
859 | ||
991d9fa0 JT |
860 | /*----------------------------------------------------------------*/ |
861 | ||
862 | /* | |
863 | * Workqueue. | |
864 | */ | |
865 | ||
866 | /* | |
867 | * Prepared mapping jobs. | |
868 | */ | |
869 | ||
870 | /* | |
871 | * This sends the bios in the cell back to the deferred_bios list. | |
872 | */ | |
a24c2569 | 873 | static void cell_defer(struct thin_c *tc, struct dm_bio_prison_cell *cell, |
991d9fa0 JT |
874 | dm_block_t data_block) |
875 | { | |
876 | struct pool *pool = tc->pool; | |
877 | unsigned long flags; | |
878 | ||
879 | spin_lock_irqsave(&pool->lock, flags); | |
880 | cell_release(cell, &pool->deferred_bios); | |
881 | spin_unlock_irqrestore(&tc->pool->lock, flags); | |
882 | ||
883 | wake_worker(pool); | |
884 | } | |
885 | ||
886 | /* | |
887 | * Same as cell_defer above, except it omits one particular detainee, | |
888 | * a write bio that covers the block and has already been processed. | |
889 | */ | |
a24c2569 | 890 | static void cell_defer_except(struct thin_c *tc, struct dm_bio_prison_cell *cell) |
991d9fa0 JT |
891 | { |
892 | struct bio_list bios; | |
991d9fa0 JT |
893 | struct pool *pool = tc->pool; |
894 | unsigned long flags; | |
895 | ||
896 | bio_list_init(&bios); | |
991d9fa0 JT |
897 | |
898 | spin_lock_irqsave(&pool->lock, flags); | |
6f94a4c4 | 899 | cell_release_no_holder(cell, &pool->deferred_bios); |
991d9fa0 JT |
900 | spin_unlock_irqrestore(&pool->lock, flags); |
901 | ||
902 | wake_worker(pool); | |
903 | } | |
904 | ||
e49e5829 JT |
905 | static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m) |
906 | { | |
907 | if (m->bio) | |
908 | m->bio->bi_end_io = m->saved_bi_end_io; | |
909 | cell_error(m->cell); | |
910 | list_del(&m->list); | |
911 | mempool_free(m, m->tc->pool->mapping_pool); | |
912 | } | |
a24c2569 | 913 | static void process_prepared_mapping(struct dm_thin_new_mapping *m) |
991d9fa0 JT |
914 | { |
915 | struct thin_c *tc = m->tc; | |
916 | struct bio *bio; | |
917 | int r; | |
918 | ||
919 | bio = m->bio; | |
920 | if (bio) | |
921 | bio->bi_end_io = m->saved_bi_end_io; | |
922 | ||
923 | if (m->err) { | |
924 | cell_error(m->cell); | |
905386f8 | 925 | goto out; |
991d9fa0 JT |
926 | } |
927 | ||
928 | /* | |
929 | * Commit the prepared block into the mapping btree. | |
930 | * Any I/O for this block arriving after this point will get | |
931 | * remapped to it directly. | |
932 | */ | |
933 | r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block); | |
934 | if (r) { | |
935 | DMERR("dm_thin_insert_block() failed"); | |
936 | cell_error(m->cell); | |
905386f8 | 937 | goto out; |
991d9fa0 JT |
938 | } |
939 | ||
940 | /* | |
941 | * Release any bios held while the block was being provisioned. | |
942 | * If we are processing a write bio that completely covers the block, | |
943 | * we already processed it so can ignore it now when processing | |
944 | * the bios in the cell. | |
945 | */ | |
946 | if (bio) { | |
6f94a4c4 | 947 | cell_defer_except(tc, m->cell); |
991d9fa0 JT |
948 | bio_endio(bio, 0); |
949 | } else | |
950 | cell_defer(tc, m->cell, m->data_block); | |
951 | ||
905386f8 | 952 | out: |
991d9fa0 JT |
953 | list_del(&m->list); |
954 | mempool_free(m, tc->pool->mapping_pool); | |
955 | } | |
956 | ||
e49e5829 | 957 | static void process_prepared_discard_fail(struct dm_thin_new_mapping *m) |
104655fd | 958 | { |
104655fd JT |
959 | struct thin_c *tc = m->tc; |
960 | ||
e49e5829 JT |
961 | bio_io_error(m->bio); |
962 | cell_defer_except(tc, m->cell); | |
963 | cell_defer_except(tc, m->cell2); | |
964 | mempool_free(m, tc->pool->mapping_pool); | |
965 | } | |
966 | ||
967 | static void process_prepared_discard_passdown(struct dm_thin_new_mapping *m) | |
968 | { | |
969 | struct thin_c *tc = m->tc; | |
104655fd | 970 | |
104655fd JT |
971 | if (m->pass_discard) |
972 | remap_and_issue(tc, m->bio, m->data_block); | |
973 | else | |
974 | bio_endio(m->bio, 0); | |
975 | ||
976 | cell_defer_except(tc, m->cell); | |
977 | cell_defer_except(tc, m->cell2); | |
978 | mempool_free(m, tc->pool->mapping_pool); | |
979 | } | |
980 | ||
e49e5829 JT |
981 | static void process_prepared_discard(struct dm_thin_new_mapping *m) |
982 | { | |
983 | int r; | |
984 | struct thin_c *tc = m->tc; | |
985 | ||
986 | r = dm_thin_remove_block(tc->td, m->virt_block); | |
987 | if (r) | |
988 | DMERR("dm_thin_remove_block() failed"); | |
989 | ||
990 | process_prepared_discard_passdown(m); | |
991 | } | |
992 | ||
104655fd | 993 | static void process_prepared(struct pool *pool, struct list_head *head, |
e49e5829 | 994 | process_mapping_fn *fn) |
991d9fa0 JT |
995 | { |
996 | unsigned long flags; | |
997 | struct list_head maps; | |
a24c2569 | 998 | struct dm_thin_new_mapping *m, *tmp; |
991d9fa0 JT |
999 | |
1000 | INIT_LIST_HEAD(&maps); | |
1001 | spin_lock_irqsave(&pool->lock, flags); | |
104655fd | 1002 | list_splice_init(head, &maps); |
991d9fa0 JT |
1003 | spin_unlock_irqrestore(&pool->lock, flags); |
1004 | ||
1005 | list_for_each_entry_safe(m, tmp, &maps, list) | |
e49e5829 | 1006 | (*fn)(m); |
991d9fa0 JT |
1007 | } |
1008 | ||
1009 | /* | |
1010 | * Deferred bio jobs. | |
1011 | */ | |
104655fd | 1012 | static int io_overlaps_block(struct pool *pool, struct bio *bio) |
991d9fa0 | 1013 | { |
f9a8e0cd | 1014 | return bio->bi_size == (pool->sectors_per_block << SECTOR_SHIFT); |
104655fd JT |
1015 | } |
1016 | ||
1017 | static int io_overwrites_block(struct pool *pool, struct bio *bio) | |
1018 | { | |
1019 | return (bio_data_dir(bio) == WRITE) && | |
1020 | io_overlaps_block(pool, bio); | |
991d9fa0 JT |
1021 | } |
1022 | ||
1023 | static void save_and_set_endio(struct bio *bio, bio_end_io_t **save, | |
1024 | bio_end_io_t *fn) | |
1025 | { | |
1026 | *save = bio->bi_end_io; | |
1027 | bio->bi_end_io = fn; | |
1028 | } | |
1029 | ||
1030 | static int ensure_next_mapping(struct pool *pool) | |
1031 | { | |
1032 | if (pool->next_mapping) | |
1033 | return 0; | |
1034 | ||
1035 | pool->next_mapping = mempool_alloc(pool->mapping_pool, GFP_ATOMIC); | |
1036 | ||
1037 | return pool->next_mapping ? 0 : -ENOMEM; | |
1038 | } | |
1039 | ||
a24c2569 | 1040 | static struct dm_thin_new_mapping *get_next_mapping(struct pool *pool) |
991d9fa0 | 1041 | { |
a24c2569 | 1042 | struct dm_thin_new_mapping *r = pool->next_mapping; |
991d9fa0 JT |
1043 | |
1044 | BUG_ON(!pool->next_mapping); | |
1045 | ||
1046 | pool->next_mapping = NULL; | |
1047 | ||
1048 | return r; | |
1049 | } | |
1050 | ||
1051 | static void schedule_copy(struct thin_c *tc, dm_block_t virt_block, | |
2dd9c257 JT |
1052 | struct dm_dev *origin, dm_block_t data_origin, |
1053 | dm_block_t data_dest, | |
a24c2569 | 1054 | struct dm_bio_prison_cell *cell, struct bio *bio) |
991d9fa0 JT |
1055 | { |
1056 | int r; | |
1057 | struct pool *pool = tc->pool; | |
a24c2569 | 1058 | struct dm_thin_new_mapping *m = get_next_mapping(pool); |
991d9fa0 JT |
1059 | |
1060 | INIT_LIST_HEAD(&m->list); | |
eb2aa48d | 1061 | m->quiesced = 0; |
991d9fa0 JT |
1062 | m->prepared = 0; |
1063 | m->tc = tc; | |
1064 | m->virt_block = virt_block; | |
1065 | m->data_block = data_dest; | |
1066 | m->cell = cell; | |
1067 | m->err = 0; | |
1068 | m->bio = NULL; | |
1069 | ||
eb2aa48d JT |
1070 | if (!ds_add_work(&pool->shared_read_ds, &m->list)) |
1071 | m->quiesced = 1; | |
991d9fa0 JT |
1072 | |
1073 | /* | |
1074 | * IO to pool_dev remaps to the pool target's data_dev. | |
1075 | * | |
1076 | * If the whole block of data is being overwritten, we can issue the | |
1077 | * bio immediately. Otherwise we use kcopyd to clone the data first. | |
1078 | */ | |
1079 | if (io_overwrites_block(pool, bio)) { | |
a24c2569 MS |
1080 | struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr; |
1081 | ||
eb2aa48d | 1082 | h->overwrite_mapping = m; |
991d9fa0 JT |
1083 | m->bio = bio; |
1084 | save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio); | |
991d9fa0 JT |
1085 | remap_and_issue(tc, bio, data_dest); |
1086 | } else { | |
1087 | struct dm_io_region from, to; | |
1088 | ||
2dd9c257 | 1089 | from.bdev = origin->bdev; |
991d9fa0 JT |
1090 | from.sector = data_origin * pool->sectors_per_block; |
1091 | from.count = pool->sectors_per_block; | |
1092 | ||
1093 | to.bdev = tc->pool_dev->bdev; | |
1094 | to.sector = data_dest * pool->sectors_per_block; | |
1095 | to.count = pool->sectors_per_block; | |
1096 | ||
1097 | r = dm_kcopyd_copy(pool->copier, &from, 1, &to, | |
1098 | 0, copy_complete, m); | |
1099 | if (r < 0) { | |
1100 | mempool_free(m, pool->mapping_pool); | |
1101 | DMERR("dm_kcopyd_copy() failed"); | |
1102 | cell_error(cell); | |
1103 | } | |
1104 | } | |
1105 | } | |
1106 | ||
2dd9c257 JT |
1107 | static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block, |
1108 | dm_block_t data_origin, dm_block_t data_dest, | |
a24c2569 | 1109 | struct dm_bio_prison_cell *cell, struct bio *bio) |
2dd9c257 JT |
1110 | { |
1111 | schedule_copy(tc, virt_block, tc->pool_dev, | |
1112 | data_origin, data_dest, cell, bio); | |
1113 | } | |
1114 | ||
1115 | static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block, | |
1116 | dm_block_t data_dest, | |
a24c2569 | 1117 | struct dm_bio_prison_cell *cell, struct bio *bio) |
2dd9c257 JT |
1118 | { |
1119 | schedule_copy(tc, virt_block, tc->origin_dev, | |
1120 | virt_block, data_dest, cell, bio); | |
1121 | } | |
1122 | ||
991d9fa0 | 1123 | static void schedule_zero(struct thin_c *tc, dm_block_t virt_block, |
a24c2569 | 1124 | dm_block_t data_block, struct dm_bio_prison_cell *cell, |
991d9fa0 JT |
1125 | struct bio *bio) |
1126 | { | |
1127 | struct pool *pool = tc->pool; | |
a24c2569 | 1128 | struct dm_thin_new_mapping *m = get_next_mapping(pool); |
991d9fa0 JT |
1129 | |
1130 | INIT_LIST_HEAD(&m->list); | |
eb2aa48d | 1131 | m->quiesced = 1; |
991d9fa0 JT |
1132 | m->prepared = 0; |
1133 | m->tc = tc; | |
1134 | m->virt_block = virt_block; | |
1135 | m->data_block = data_block; | |
1136 | m->cell = cell; | |
1137 | m->err = 0; | |
1138 | m->bio = NULL; | |
1139 | ||
1140 | /* | |
1141 | * If the whole block of data is being overwritten or we are not | |
1142 | * zeroing pre-existing data, we can issue the bio immediately. | |
1143 | * Otherwise we use kcopyd to zero the data first. | |
1144 | */ | |
67e2e2b2 | 1145 | if (!pool->pf.zero_new_blocks) |
991d9fa0 JT |
1146 | process_prepared_mapping(m); |
1147 | ||
1148 | else if (io_overwrites_block(pool, bio)) { | |
a24c2569 MS |
1149 | struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr; |
1150 | ||
eb2aa48d | 1151 | h->overwrite_mapping = m; |
991d9fa0 JT |
1152 | m->bio = bio; |
1153 | save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio); | |
991d9fa0 | 1154 | remap_and_issue(tc, bio, data_block); |
991d9fa0 JT |
1155 | } else { |
1156 | int r; | |
1157 | struct dm_io_region to; | |
1158 | ||
1159 | to.bdev = tc->pool_dev->bdev; | |
1160 | to.sector = data_block * pool->sectors_per_block; | |
1161 | to.count = pool->sectors_per_block; | |
1162 | ||
1163 | r = dm_kcopyd_zero(pool->copier, 1, &to, 0, copy_complete, m); | |
1164 | if (r < 0) { | |
1165 | mempool_free(m, pool->mapping_pool); | |
1166 | DMERR("dm_kcopyd_zero() failed"); | |
1167 | cell_error(cell); | |
1168 | } | |
1169 | } | |
1170 | } | |
1171 | ||
e49e5829 JT |
1172 | static int commit(struct pool *pool) |
1173 | { | |
1174 | int r; | |
1175 | ||
1176 | r = dm_pool_commit_metadata(pool->pmd); | |
1177 | if (r) | |
1178 | DMERR("commit failed, error = %d", r); | |
1179 | ||
1180 | return r; | |
1181 | } | |
1182 | ||
1183 | /* | |
1184 | * A non-zero return indicates read_only or fail_io mode. | |
1185 | * Many callers don't care about the return value. | |
1186 | */ | |
1187 | static int commit_or_fallback(struct pool *pool) | |
1188 | { | |
1189 | int r; | |
1190 | ||
1191 | if (get_pool_mode(pool) != PM_WRITE) | |
1192 | return -EINVAL; | |
1193 | ||
1194 | r = commit(pool); | |
1195 | if (r) | |
1196 | set_pool_mode(pool, PM_READ_ONLY); | |
1197 | ||
1198 | return r; | |
1199 | } | |
1200 | ||
991d9fa0 JT |
1201 | static int alloc_data_block(struct thin_c *tc, dm_block_t *result) |
1202 | { | |
1203 | int r; | |
1204 | dm_block_t free_blocks; | |
1205 | unsigned long flags; | |
1206 | struct pool *pool = tc->pool; | |
1207 | ||
1208 | r = dm_pool_get_free_block_count(pool->pmd, &free_blocks); | |
1209 | if (r) | |
1210 | return r; | |
1211 | ||
1212 | if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) { | |
1213 | DMWARN("%s: reached low water mark, sending event.", | |
1214 | dm_device_name(pool->pool_md)); | |
1215 | spin_lock_irqsave(&pool->lock, flags); | |
1216 | pool->low_water_triggered = 1; | |
1217 | spin_unlock_irqrestore(&pool->lock, flags); | |
1218 | dm_table_event(pool->ti->table); | |
1219 | } | |
1220 | ||
1221 | if (!free_blocks) { | |
1222 | if (pool->no_free_space) | |
1223 | return -ENOSPC; | |
1224 | else { | |
1225 | /* | |
1226 | * Try to commit to see if that will free up some | |
1227 | * more space. | |
1228 | */ | |
e49e5829 | 1229 | (void) commit_or_fallback(pool); |
991d9fa0 JT |
1230 | |
1231 | r = dm_pool_get_free_block_count(pool->pmd, &free_blocks); | |
1232 | if (r) | |
1233 | return r; | |
1234 | ||
1235 | /* | |
1236 | * If we still have no space we set a flag to avoid | |
1237 | * doing all this checking and return -ENOSPC. | |
1238 | */ | |
1239 | if (!free_blocks) { | |
1240 | DMWARN("%s: no free space available.", | |
1241 | dm_device_name(pool->pool_md)); | |
1242 | spin_lock_irqsave(&pool->lock, flags); | |
1243 | pool->no_free_space = 1; | |
1244 | spin_unlock_irqrestore(&pool->lock, flags); | |
1245 | return -ENOSPC; | |
1246 | } | |
1247 | } | |
1248 | } | |
1249 | ||
1250 | r = dm_pool_alloc_data_block(pool->pmd, result); | |
1251 | if (r) | |
1252 | return r; | |
1253 | ||
1254 | return 0; | |
1255 | } | |
1256 | ||
1257 | /* | |
1258 | * If we have run out of space, queue bios until the device is | |
1259 | * resumed, presumably after having been reloaded with more space. | |
1260 | */ | |
1261 | static void retry_on_resume(struct bio *bio) | |
1262 | { | |
a24c2569 | 1263 | struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr; |
eb2aa48d | 1264 | struct thin_c *tc = h->tc; |
991d9fa0 JT |
1265 | struct pool *pool = tc->pool; |
1266 | unsigned long flags; | |
1267 | ||
1268 | spin_lock_irqsave(&pool->lock, flags); | |
1269 | bio_list_add(&pool->retry_on_resume_list, bio); | |
1270 | spin_unlock_irqrestore(&pool->lock, flags); | |
1271 | } | |
1272 | ||
a24c2569 | 1273 | static void no_space(struct dm_bio_prison_cell *cell) |
991d9fa0 JT |
1274 | { |
1275 | struct bio *bio; | |
1276 | struct bio_list bios; | |
1277 | ||
1278 | bio_list_init(&bios); | |
1279 | cell_release(cell, &bios); | |
1280 | ||
1281 | while ((bio = bio_list_pop(&bios))) | |
1282 | retry_on_resume(bio); | |
1283 | } | |
1284 | ||
104655fd JT |
1285 | static void process_discard(struct thin_c *tc, struct bio *bio) |
1286 | { | |
1287 | int r; | |
c3a0ce2e | 1288 | unsigned long flags; |
104655fd | 1289 | struct pool *pool = tc->pool; |
a24c2569 | 1290 | struct dm_bio_prison_cell *cell, *cell2; |
104655fd JT |
1291 | struct cell_key key, key2; |
1292 | dm_block_t block = get_bio_block(tc, bio); | |
1293 | struct dm_thin_lookup_result lookup_result; | |
a24c2569 | 1294 | struct dm_thin_new_mapping *m; |
104655fd JT |
1295 | |
1296 | build_virtual_key(tc->td, block, &key); | |
1297 | if (bio_detain(tc->pool->prison, &key, bio, &cell)) | |
1298 | return; | |
1299 | ||
1300 | r = dm_thin_find_block(tc->td, block, 1, &lookup_result); | |
1301 | switch (r) { | |
1302 | case 0: | |
1303 | /* | |
1304 | * Check nobody is fiddling with this pool block. This can | |
1305 | * happen if someone's in the process of breaking sharing | |
1306 | * on this block. | |
1307 | */ | |
1308 | build_data_key(tc->td, lookup_result.block, &key2); | |
1309 | if (bio_detain(tc->pool->prison, &key2, bio, &cell2)) { | |
1310 | cell_release_singleton(cell, bio); | |
1311 | break; | |
1312 | } | |
1313 | ||
1314 | if (io_overlaps_block(pool, bio)) { | |
1315 | /* | |
1316 | * IO may still be going to the destination block. We must | |
1317 | * quiesce before we can do the removal. | |
1318 | */ | |
1319 | m = get_next_mapping(pool); | |
1320 | m->tc = tc; | |
17b7d63f | 1321 | m->pass_discard = (!lookup_result.shared) && pool->pf.discard_passdown; |
104655fd JT |
1322 | m->virt_block = block; |
1323 | m->data_block = lookup_result.block; | |
1324 | m->cell = cell; | |
1325 | m->cell2 = cell2; | |
1326 | m->err = 0; | |
1327 | m->bio = bio; | |
1328 | ||
1329 | if (!ds_add_work(&pool->all_io_ds, &m->list)) { | |
c3a0ce2e | 1330 | spin_lock_irqsave(&pool->lock, flags); |
104655fd | 1331 | list_add(&m->list, &pool->prepared_discards); |
c3a0ce2e | 1332 | spin_unlock_irqrestore(&pool->lock, flags); |
104655fd JT |
1333 | wake_worker(pool); |
1334 | } | |
1335 | } else { | |
1336 | /* | |
49296309 MP |
1337 | * The DM core makes sure that the discard doesn't span |
1338 | * a block boundary. So we submit the discard of a | |
1339 | * partial block appropriately. | |
104655fd | 1340 | */ |
104655fd JT |
1341 | cell_release_singleton(cell, bio); |
1342 | cell_release_singleton(cell2, bio); | |
650d2a06 MP |
1343 | if ((!lookup_result.shared) && pool->pf.discard_passdown) |
1344 | remap_and_issue(tc, bio, lookup_result.block); | |
1345 | else | |
1346 | bio_endio(bio, 0); | |
104655fd JT |
1347 | } |
1348 | break; | |
1349 | ||
1350 | case -ENODATA: | |
1351 | /* | |
1352 | * It isn't provisioned, just forget it. | |
1353 | */ | |
1354 | cell_release_singleton(cell, bio); | |
1355 | bio_endio(bio, 0); | |
1356 | break; | |
1357 | ||
1358 | default: | |
1359 | DMERR("discard: find block unexpectedly returned %d", r); | |
1360 | cell_release_singleton(cell, bio); | |
1361 | bio_io_error(bio); | |
1362 | break; | |
1363 | } | |
1364 | } | |
1365 | ||
991d9fa0 JT |
1366 | static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block, |
1367 | struct cell_key *key, | |
1368 | struct dm_thin_lookup_result *lookup_result, | |
a24c2569 | 1369 | struct dm_bio_prison_cell *cell) |
991d9fa0 JT |
1370 | { |
1371 | int r; | |
1372 | dm_block_t data_block; | |
1373 | ||
1374 | r = alloc_data_block(tc, &data_block); | |
1375 | switch (r) { | |
1376 | case 0: | |
2dd9c257 JT |
1377 | schedule_internal_copy(tc, block, lookup_result->block, |
1378 | data_block, cell, bio); | |
991d9fa0 JT |
1379 | break; |
1380 | ||
1381 | case -ENOSPC: | |
1382 | no_space(cell); | |
1383 | break; | |
1384 | ||
1385 | default: | |
1386 | DMERR("%s: alloc_data_block() failed, error = %d", __func__, r); | |
1387 | cell_error(cell); | |
1388 | break; | |
1389 | } | |
1390 | } | |
1391 | ||
1392 | static void process_shared_bio(struct thin_c *tc, struct bio *bio, | |
1393 | dm_block_t block, | |
1394 | struct dm_thin_lookup_result *lookup_result) | |
1395 | { | |
a24c2569 | 1396 | struct dm_bio_prison_cell *cell; |
991d9fa0 JT |
1397 | struct pool *pool = tc->pool; |
1398 | struct cell_key key; | |
1399 | ||
1400 | /* | |
1401 | * If cell is already occupied, then sharing is already in the process | |
1402 | * of being broken so we have nothing further to do here. | |
1403 | */ | |
1404 | build_data_key(tc->td, lookup_result->block, &key); | |
1405 | if (bio_detain(pool->prison, &key, bio, &cell)) | |
1406 | return; | |
1407 | ||
60049701 | 1408 | if (bio_data_dir(bio) == WRITE && bio->bi_size) |
991d9fa0 JT |
1409 | break_sharing(tc, bio, block, &key, lookup_result, cell); |
1410 | else { | |
a24c2569 | 1411 | struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr; |
991d9fa0 | 1412 | |
eb2aa48d | 1413 | h->shared_read_entry = ds_inc(&pool->shared_read_ds); |
991d9fa0 JT |
1414 | |
1415 | cell_release_singleton(cell, bio); | |
1416 | remap_and_issue(tc, bio, lookup_result->block); | |
1417 | } | |
1418 | } | |
1419 | ||
1420 | static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block, | |
a24c2569 | 1421 | struct dm_bio_prison_cell *cell) |
991d9fa0 JT |
1422 | { |
1423 | int r; | |
1424 | dm_block_t data_block; | |
1425 | ||
1426 | /* | |
1427 | * Remap empty bios (flushes) immediately, without provisioning. | |
1428 | */ | |
1429 | if (!bio->bi_size) { | |
1430 | cell_release_singleton(cell, bio); | |
1431 | remap_and_issue(tc, bio, 0); | |
1432 | return; | |
1433 | } | |
1434 | ||
1435 | /* | |
1436 | * Fill read bios with zeroes and complete them immediately. | |
1437 | */ | |
1438 | if (bio_data_dir(bio) == READ) { | |
1439 | zero_fill_bio(bio); | |
1440 | cell_release_singleton(cell, bio); | |
1441 | bio_endio(bio, 0); | |
1442 | return; | |
1443 | } | |
1444 | ||
1445 | r = alloc_data_block(tc, &data_block); | |
1446 | switch (r) { | |
1447 | case 0: | |
2dd9c257 JT |
1448 | if (tc->origin_dev) |
1449 | schedule_external_copy(tc, block, data_block, cell, bio); | |
1450 | else | |
1451 | schedule_zero(tc, block, data_block, cell, bio); | |
991d9fa0 JT |
1452 | break; |
1453 | ||
1454 | case -ENOSPC: | |
1455 | no_space(cell); | |
1456 | break; | |
1457 | ||
1458 | default: | |
1459 | DMERR("%s: alloc_data_block() failed, error = %d", __func__, r); | |
e49e5829 | 1460 | set_pool_mode(tc->pool, PM_READ_ONLY); |
991d9fa0 JT |
1461 | cell_error(cell); |
1462 | break; | |
1463 | } | |
1464 | } | |
1465 | ||
1466 | static void process_bio(struct thin_c *tc, struct bio *bio) | |
1467 | { | |
1468 | int r; | |
1469 | dm_block_t block = get_bio_block(tc, bio); | |
a24c2569 | 1470 | struct dm_bio_prison_cell *cell; |
991d9fa0 JT |
1471 | struct cell_key key; |
1472 | struct dm_thin_lookup_result lookup_result; | |
1473 | ||
1474 | /* | |
1475 | * If cell is already occupied, then the block is already | |
1476 | * being provisioned so we have nothing further to do here. | |
1477 | */ | |
1478 | build_virtual_key(tc->td, block, &key); | |
1479 | if (bio_detain(tc->pool->prison, &key, bio, &cell)) | |
1480 | return; | |
1481 | ||
1482 | r = dm_thin_find_block(tc->td, block, 1, &lookup_result); | |
1483 | switch (r) { | |
1484 | case 0: | |
1485 | /* | |
1486 | * We can release this cell now. This thread is the only | |
1487 | * one that puts bios into a cell, and we know there were | |
1488 | * no preceding bios. | |
1489 | */ | |
1490 | /* | |
1491 | * TODO: this will probably have to change when discard goes | |
1492 | * back in. | |
1493 | */ | |
1494 | cell_release_singleton(cell, bio); | |
1495 | ||
1496 | if (lookup_result.shared) | |
1497 | process_shared_bio(tc, bio, block, &lookup_result); | |
1498 | else | |
1499 | remap_and_issue(tc, bio, lookup_result.block); | |
1500 | break; | |
1501 | ||
1502 | case -ENODATA: | |
2dd9c257 JT |
1503 | if (bio_data_dir(bio) == READ && tc->origin_dev) { |
1504 | cell_release_singleton(cell, bio); | |
1505 | remap_to_origin_and_issue(tc, bio); | |
1506 | } else | |
1507 | provision_block(tc, bio, block, cell); | |
991d9fa0 JT |
1508 | break; |
1509 | ||
1510 | default: | |
1511 | DMERR("dm_thin_find_block() failed, error = %d", r); | |
104655fd | 1512 | cell_release_singleton(cell, bio); |
991d9fa0 JT |
1513 | bio_io_error(bio); |
1514 | break; | |
1515 | } | |
1516 | } | |
1517 | ||
e49e5829 JT |
1518 | static void process_bio_read_only(struct thin_c *tc, struct bio *bio) |
1519 | { | |
1520 | int r; | |
1521 | int rw = bio_data_dir(bio); | |
1522 | dm_block_t block = get_bio_block(tc, bio); | |
1523 | struct dm_thin_lookup_result lookup_result; | |
1524 | ||
1525 | r = dm_thin_find_block(tc->td, block, 1, &lookup_result); | |
1526 | switch (r) { | |
1527 | case 0: | |
1528 | if (lookup_result.shared && (rw == WRITE) && bio->bi_size) | |
1529 | bio_io_error(bio); | |
1530 | else | |
1531 | remap_and_issue(tc, bio, lookup_result.block); | |
1532 | break; | |
1533 | ||
1534 | case -ENODATA: | |
1535 | if (rw != READ) { | |
1536 | bio_io_error(bio); | |
1537 | break; | |
1538 | } | |
1539 | ||
1540 | if (tc->origin_dev) { | |
1541 | remap_to_origin_and_issue(tc, bio); | |
1542 | break; | |
1543 | } | |
1544 | ||
1545 | zero_fill_bio(bio); | |
1546 | bio_endio(bio, 0); | |
1547 | break; | |
1548 | ||
1549 | default: | |
1550 | DMERR("dm_thin_find_block() failed, error = %d", r); | |
1551 | bio_io_error(bio); | |
1552 | break; | |
1553 | } | |
1554 | } | |
1555 | ||
1556 | static void process_bio_fail(struct thin_c *tc, struct bio *bio) | |
1557 | { | |
1558 | bio_io_error(bio); | |
1559 | } | |
1560 | ||
905e51b3 JT |
1561 | static int need_commit_due_to_time(struct pool *pool) |
1562 | { | |
1563 | return jiffies < pool->last_commit_jiffies || | |
1564 | jiffies > pool->last_commit_jiffies + COMMIT_PERIOD; | |
1565 | } | |
1566 | ||
991d9fa0 JT |
1567 | static void process_deferred_bios(struct pool *pool) |
1568 | { | |
1569 | unsigned long flags; | |
1570 | struct bio *bio; | |
1571 | struct bio_list bios; | |
991d9fa0 JT |
1572 | |
1573 | bio_list_init(&bios); | |
1574 | ||
1575 | spin_lock_irqsave(&pool->lock, flags); | |
1576 | bio_list_merge(&bios, &pool->deferred_bios); | |
1577 | bio_list_init(&pool->deferred_bios); | |
1578 | spin_unlock_irqrestore(&pool->lock, flags); | |
1579 | ||
1580 | while ((bio = bio_list_pop(&bios))) { | |
a24c2569 | 1581 | struct dm_thin_endio_hook *h = dm_get_mapinfo(bio)->ptr; |
eb2aa48d JT |
1582 | struct thin_c *tc = h->tc; |
1583 | ||
991d9fa0 JT |
1584 | /* |
1585 | * If we've got no free new_mapping structs, and processing | |
1586 | * this bio might require one, we pause until there are some | |
1587 | * prepared mappings to process. | |
1588 | */ | |
1589 | if (ensure_next_mapping(pool)) { | |
1590 | spin_lock_irqsave(&pool->lock, flags); | |
1591 | bio_list_merge(&pool->deferred_bios, &bios); | |
1592 | spin_unlock_irqrestore(&pool->lock, flags); | |
1593 | ||
1594 | break; | |
1595 | } | |
104655fd JT |
1596 | |
1597 | if (bio->bi_rw & REQ_DISCARD) | |
e49e5829 | 1598 | pool->process_discard(tc, bio); |
104655fd | 1599 | else |
e49e5829 | 1600 | pool->process_bio(tc, bio); |
991d9fa0 JT |
1601 | } |
1602 | ||
1603 | /* | |
1604 | * If there are any deferred flush bios, we must commit | |
1605 | * the metadata before issuing them. | |
1606 | */ | |
1607 | bio_list_init(&bios); | |
1608 | spin_lock_irqsave(&pool->lock, flags); | |
1609 | bio_list_merge(&bios, &pool->deferred_flush_bios); | |
1610 | bio_list_init(&pool->deferred_flush_bios); | |
1611 | spin_unlock_irqrestore(&pool->lock, flags); | |
1612 | ||
905e51b3 | 1613 | if (bio_list_empty(&bios) && !need_commit_due_to_time(pool)) |
991d9fa0 JT |
1614 | return; |
1615 | ||
e49e5829 | 1616 | if (commit_or_fallback(pool)) { |
991d9fa0 JT |
1617 | while ((bio = bio_list_pop(&bios))) |
1618 | bio_io_error(bio); | |
1619 | return; | |
1620 | } | |
905e51b3 | 1621 | pool->last_commit_jiffies = jiffies; |
991d9fa0 JT |
1622 | |
1623 | while ((bio = bio_list_pop(&bios))) | |
1624 | generic_make_request(bio); | |
1625 | } | |
1626 | ||
1627 | static void do_worker(struct work_struct *ws) | |
1628 | { | |
1629 | struct pool *pool = container_of(ws, struct pool, worker); | |
1630 | ||
e49e5829 JT |
1631 | process_prepared(pool, &pool->prepared_mappings, &pool->process_prepared_mapping); |
1632 | process_prepared(pool, &pool->prepared_discards, &pool->process_prepared_discard); | |
991d9fa0 JT |
1633 | process_deferred_bios(pool); |
1634 | } | |
1635 | ||
905e51b3 JT |
1636 | /* |
1637 | * We want to commit periodically so that not too much | |
1638 | * unwritten data builds up. | |
1639 | */ | |
1640 | static void do_waker(struct work_struct *ws) | |
1641 | { | |
1642 | struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker); | |
1643 | wake_worker(pool); | |
1644 | queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD); | |
1645 | } | |
1646 | ||
991d9fa0 JT |
1647 | /*----------------------------------------------------------------*/ |
1648 | ||
e49e5829 JT |
1649 | static enum pool_mode get_pool_mode(struct pool *pool) |
1650 | { | |
1651 | return pool->pf.mode; | |
1652 | } | |
1653 | ||
1654 | static void set_pool_mode(struct pool *pool, enum pool_mode mode) | |
1655 | { | |
1656 | int r; | |
1657 | ||
1658 | pool->pf.mode = mode; | |
1659 | ||
1660 | switch (mode) { | |
1661 | case PM_FAIL: | |
1662 | DMERR("switching pool to failure mode"); | |
1663 | pool->process_bio = process_bio_fail; | |
1664 | pool->process_discard = process_bio_fail; | |
1665 | pool->process_prepared_mapping = process_prepared_mapping_fail; | |
1666 | pool->process_prepared_discard = process_prepared_discard_fail; | |
1667 | break; | |
1668 | ||
1669 | case PM_READ_ONLY: | |
1670 | DMERR("switching pool to read-only mode"); | |
1671 | r = dm_pool_abort_metadata(pool->pmd); | |
1672 | if (r) { | |
1673 | DMERR("aborting transaction failed"); | |
1674 | set_pool_mode(pool, PM_FAIL); | |
1675 | } else { | |
1676 | dm_pool_metadata_read_only(pool->pmd); | |
1677 | pool->process_bio = process_bio_read_only; | |
1678 | pool->process_discard = process_discard; | |
1679 | pool->process_prepared_mapping = process_prepared_mapping_fail; | |
1680 | pool->process_prepared_discard = process_prepared_discard_passdown; | |
1681 | } | |
1682 | break; | |
1683 | ||
1684 | case PM_WRITE: | |
1685 | pool->process_bio = process_bio; | |
1686 | pool->process_discard = process_discard; | |
1687 | pool->process_prepared_mapping = process_prepared_mapping; | |
1688 | pool->process_prepared_discard = process_prepared_discard; | |
1689 | break; | |
1690 | } | |
1691 | } | |
1692 | ||
1693 | /*----------------------------------------------------------------*/ | |
1694 | ||
991d9fa0 JT |
1695 | /* |
1696 | * Mapping functions. | |
1697 | */ | |
1698 | ||
1699 | /* | |
1700 | * Called only while mapping a thin bio to hand it over to the workqueue. | |
1701 | */ | |
1702 | static void thin_defer_bio(struct thin_c *tc, struct bio *bio) | |
1703 | { | |
1704 | unsigned long flags; | |
1705 | struct pool *pool = tc->pool; | |
1706 | ||
1707 | spin_lock_irqsave(&pool->lock, flags); | |
1708 | bio_list_add(&pool->deferred_bios, bio); | |
1709 | spin_unlock_irqrestore(&pool->lock, flags); | |
1710 | ||
1711 | wake_worker(pool); | |
1712 | } | |
1713 | ||
a24c2569 | 1714 | static struct dm_thin_endio_hook *thin_hook_bio(struct thin_c *tc, struct bio *bio) |
eb2aa48d JT |
1715 | { |
1716 | struct pool *pool = tc->pool; | |
a24c2569 | 1717 | struct dm_thin_endio_hook *h = mempool_alloc(pool->endio_hook_pool, GFP_NOIO); |
eb2aa48d JT |
1718 | |
1719 | h->tc = tc; | |
1720 | h->shared_read_entry = NULL; | |
104655fd | 1721 | h->all_io_entry = bio->bi_rw & REQ_DISCARD ? NULL : ds_inc(&pool->all_io_ds); |
eb2aa48d JT |
1722 | h->overwrite_mapping = NULL; |
1723 | ||
1724 | return h; | |
1725 | } | |
1726 | ||
991d9fa0 JT |
1727 | /* |
1728 | * Non-blocking function called from the thin target's map function. | |
1729 | */ | |
1730 | static int thin_bio_map(struct dm_target *ti, struct bio *bio, | |
1731 | union map_info *map_context) | |
1732 | { | |
1733 | int r; | |
1734 | struct thin_c *tc = ti->private; | |
1735 | dm_block_t block = get_bio_block(tc, bio); | |
1736 | struct dm_thin_device *td = tc->td; | |
1737 | struct dm_thin_lookup_result result; | |
1738 | ||
eb2aa48d | 1739 | map_context->ptr = thin_hook_bio(tc, bio); |
e49e5829 JT |
1740 | |
1741 | if (get_pool_mode(tc->pool) == PM_FAIL) { | |
1742 | bio_io_error(bio); | |
1743 | return DM_MAPIO_SUBMITTED; | |
1744 | } | |
1745 | ||
104655fd | 1746 | if (bio->bi_rw & (REQ_DISCARD | REQ_FLUSH | REQ_FUA)) { |
991d9fa0 JT |
1747 | thin_defer_bio(tc, bio); |
1748 | return DM_MAPIO_SUBMITTED; | |
1749 | } | |
1750 | ||
1751 | r = dm_thin_find_block(td, block, 0, &result); | |
1752 | ||
1753 | /* | |
1754 | * Note that we defer readahead too. | |
1755 | */ | |
1756 | switch (r) { | |
1757 | case 0: | |
1758 | if (unlikely(result.shared)) { | |
1759 | /* | |
1760 | * We have a race condition here between the | |
1761 | * result.shared value returned by the lookup and | |
1762 | * snapshot creation, which may cause new | |
1763 | * sharing. | |
1764 | * | |
1765 | * To avoid this always quiesce the origin before | |
1766 | * taking the snap. You want to do this anyway to | |
1767 | * ensure a consistent application view | |
1768 | * (i.e. lockfs). | |
1769 | * | |
1770 | * More distant ancestors are irrelevant. The | |
1771 | * shared flag will be set in their case. | |
1772 | */ | |
1773 | thin_defer_bio(tc, bio); | |
1774 | r = DM_MAPIO_SUBMITTED; | |
1775 | } else { | |
1776 | remap(tc, bio, result.block); | |
1777 | r = DM_MAPIO_REMAPPED; | |
1778 | } | |
1779 | break; | |
1780 | ||
1781 | case -ENODATA: | |
e49e5829 JT |
1782 | if (get_pool_mode(tc->pool) == PM_READ_ONLY) { |
1783 | /* | |
1784 | * This block isn't provisioned, and we have no way | |
1785 | * of doing so. Just error it. | |
1786 | */ | |
1787 | bio_io_error(bio); | |
1788 | r = DM_MAPIO_SUBMITTED; | |
1789 | break; | |
1790 | } | |
1791 | /* fall through */ | |
1792 | ||
1793 | case -EWOULDBLOCK: | |
991d9fa0 JT |
1794 | /* |
1795 | * In future, the failed dm_thin_find_block above could | |
1796 | * provide the hint to load the metadata into cache. | |
1797 | */ | |
991d9fa0 JT |
1798 | thin_defer_bio(tc, bio); |
1799 | r = DM_MAPIO_SUBMITTED; | |
1800 | break; | |
e49e5829 JT |
1801 | |
1802 | default: | |
1803 | /* | |
1804 | * Must always call bio_io_error on failure. | |
1805 | * dm_thin_find_block can fail with -EINVAL if the | |
1806 | * pool is switched to fail-io mode. | |
1807 | */ | |
1808 | bio_io_error(bio); | |
1809 | r = DM_MAPIO_SUBMITTED; | |
1810 | break; | |
991d9fa0 JT |
1811 | } |
1812 | ||
1813 | return r; | |
1814 | } | |
1815 | ||
1816 | static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits) | |
1817 | { | |
1818 | int r; | |
1819 | unsigned long flags; | |
1820 | struct pool_c *pt = container_of(cb, struct pool_c, callbacks); | |
1821 | ||
1822 | spin_lock_irqsave(&pt->pool->lock, flags); | |
1823 | r = !bio_list_empty(&pt->pool->retry_on_resume_list); | |
1824 | spin_unlock_irqrestore(&pt->pool->lock, flags); | |
1825 | ||
1826 | if (!r) { | |
1827 | struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); | |
1828 | r = bdi_congested(&q->backing_dev_info, bdi_bits); | |
1829 | } | |
1830 | ||
1831 | return r; | |
1832 | } | |
1833 | ||
1834 | static void __requeue_bios(struct pool *pool) | |
1835 | { | |
1836 | bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list); | |
1837 | bio_list_init(&pool->retry_on_resume_list); | |
1838 | } | |
1839 | ||
1840 | /*---------------------------------------------------------------- | |
1841 | * Binding of control targets to a pool object | |
1842 | *--------------------------------------------------------------*/ | |
9bc142dd MS |
1843 | static bool data_dev_supports_discard(struct pool_c *pt) |
1844 | { | |
1845 | struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); | |
1846 | ||
1847 | return q && blk_queue_discard(q); | |
1848 | } | |
1849 | ||
1850 | /* | |
1851 | * If discard_passdown was enabled verify that the data device | |
0424caa1 | 1852 | * supports discards. Disable discard_passdown if not. |
9bc142dd | 1853 | */ |
0424caa1 | 1854 | static void disable_passdown_if_not_supported(struct pool_c *pt) |
9bc142dd | 1855 | { |
0424caa1 MS |
1856 | struct pool *pool = pt->pool; |
1857 | struct block_device *data_bdev = pt->data_dev->bdev; | |
1858 | struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits; | |
1859 | sector_t block_size = pool->sectors_per_block << SECTOR_SHIFT; | |
1860 | const char *reason = NULL; | |
9bc142dd MS |
1861 | char buf[BDEVNAME_SIZE]; |
1862 | ||
0424caa1 | 1863 | if (!pt->adjusted_pf.discard_passdown) |
9bc142dd MS |
1864 | return; |
1865 | ||
0424caa1 MS |
1866 | if (!data_dev_supports_discard(pt)) |
1867 | reason = "discard unsupported"; | |
1868 | ||
1869 | else if (data_limits->max_discard_sectors < pool->sectors_per_block) | |
1870 | reason = "max discard sectors smaller than a block"; | |
9bc142dd | 1871 | |
0424caa1 MS |
1872 | else if (data_limits->discard_granularity > block_size) |
1873 | reason = "discard granularity larger than a block"; | |
1874 | ||
1875 | else if (block_size & (data_limits->discard_granularity - 1)) | |
1876 | reason = "discard granularity not a factor of block size"; | |
1877 | ||
1878 | if (reason) { | |
1879 | DMWARN("Data device (%s) %s: Disabling discard passdown.", bdevname(data_bdev, buf), reason); | |
1880 | pt->adjusted_pf.discard_passdown = false; | |
1881 | } | |
9bc142dd MS |
1882 | } |
1883 | ||
991d9fa0 JT |
1884 | static int bind_control_target(struct pool *pool, struct dm_target *ti) |
1885 | { | |
1886 | struct pool_c *pt = ti->private; | |
1887 | ||
e49e5829 JT |
1888 | /* |
1889 | * We want to make sure that degraded pools are never upgraded. | |
1890 | */ | |
1891 | enum pool_mode old_mode = pool->pf.mode; | |
0424caa1 | 1892 | enum pool_mode new_mode = pt->adjusted_pf.mode; |
e49e5829 JT |
1893 | |
1894 | if (old_mode > new_mode) | |
1895 | new_mode = old_mode; | |
1896 | ||
991d9fa0 JT |
1897 | pool->ti = ti; |
1898 | pool->low_water_blocks = pt->low_water_blocks; | |
0424caa1 | 1899 | pool->pf = pt->adjusted_pf; |
991d9fa0 | 1900 | |
9bc142dd | 1901 | set_pool_mode(pool, new_mode); |
f402693d | 1902 | |
991d9fa0 JT |
1903 | return 0; |
1904 | } | |
1905 | ||
1906 | static void unbind_control_target(struct pool *pool, struct dm_target *ti) | |
1907 | { | |
1908 | if (pool->ti == ti) | |
1909 | pool->ti = NULL; | |
1910 | } | |
1911 | ||
1912 | /*---------------------------------------------------------------- | |
1913 | * Pool creation | |
1914 | *--------------------------------------------------------------*/ | |
67e2e2b2 JT |
1915 | /* Initialize pool features. */ |
1916 | static void pool_features_init(struct pool_features *pf) | |
1917 | { | |
e49e5829 | 1918 | pf->mode = PM_WRITE; |
9bc142dd MS |
1919 | pf->zero_new_blocks = true; |
1920 | pf->discard_enabled = true; | |
1921 | pf->discard_passdown = true; | |
67e2e2b2 JT |
1922 | } |
1923 | ||
991d9fa0 JT |
1924 | static void __pool_destroy(struct pool *pool) |
1925 | { | |
1926 | __pool_table_remove(pool); | |
1927 | ||
1928 | if (dm_pool_metadata_close(pool->pmd) < 0) | |
1929 | DMWARN("%s: dm_pool_metadata_close() failed.", __func__); | |
1930 | ||
1931 | prison_destroy(pool->prison); | |
1932 | dm_kcopyd_client_destroy(pool->copier); | |
1933 | ||
1934 | if (pool->wq) | |
1935 | destroy_workqueue(pool->wq); | |
1936 | ||
1937 | if (pool->next_mapping) | |
1938 | mempool_free(pool->next_mapping, pool->mapping_pool); | |
1939 | mempool_destroy(pool->mapping_pool); | |
1940 | mempool_destroy(pool->endio_hook_pool); | |
1941 | kfree(pool); | |
1942 | } | |
1943 | ||
a24c2569 MS |
1944 | static struct kmem_cache *_new_mapping_cache; |
1945 | static struct kmem_cache *_endio_hook_cache; | |
1946 | ||
991d9fa0 JT |
1947 | static struct pool *pool_create(struct mapped_device *pool_md, |
1948 | struct block_device *metadata_dev, | |
e49e5829 JT |
1949 | unsigned long block_size, |
1950 | int read_only, char **error) | |
991d9fa0 JT |
1951 | { |
1952 | int r; | |
1953 | void *err_p; | |
1954 | struct pool *pool; | |
1955 | struct dm_pool_metadata *pmd; | |
e49e5829 | 1956 | bool format_device = read_only ? false : true; |
991d9fa0 | 1957 | |
e49e5829 | 1958 | pmd = dm_pool_metadata_open(metadata_dev, block_size, format_device); |
991d9fa0 JT |
1959 | if (IS_ERR(pmd)) { |
1960 | *error = "Error creating metadata object"; | |
1961 | return (struct pool *)pmd; | |
1962 | } | |
1963 | ||
1964 | pool = kmalloc(sizeof(*pool), GFP_KERNEL); | |
1965 | if (!pool) { | |
1966 | *error = "Error allocating memory for pool"; | |
1967 | err_p = ERR_PTR(-ENOMEM); | |
1968 | goto bad_pool; | |
1969 | } | |
1970 | ||
1971 | pool->pmd = pmd; | |
1972 | pool->sectors_per_block = block_size; | |
f9a8e0cd MP |
1973 | if (block_size & (block_size - 1)) |
1974 | pool->sectors_per_block_shift = -1; | |
1975 | else | |
1976 | pool->sectors_per_block_shift = __ffs(block_size); | |
991d9fa0 | 1977 | pool->low_water_blocks = 0; |
67e2e2b2 | 1978 | pool_features_init(&pool->pf); |
991d9fa0 JT |
1979 | pool->prison = prison_create(PRISON_CELLS); |
1980 | if (!pool->prison) { | |
1981 | *error = "Error creating pool's bio prison"; | |
1982 | err_p = ERR_PTR(-ENOMEM); | |
1983 | goto bad_prison; | |
1984 | } | |
1985 | ||
1986 | pool->copier = dm_kcopyd_client_create(); | |
1987 | if (IS_ERR(pool->copier)) { | |
1988 | r = PTR_ERR(pool->copier); | |
1989 | *error = "Error creating pool's kcopyd client"; | |
1990 | err_p = ERR_PTR(r); | |
1991 | goto bad_kcopyd_client; | |
1992 | } | |
1993 | ||
1994 | /* | |
1995 | * Create singlethreaded workqueue that will service all devices | |
1996 | * that use this metadata. | |
1997 | */ | |
1998 | pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); | |
1999 | if (!pool->wq) { | |
2000 | *error = "Error creating pool's workqueue"; | |
2001 | err_p = ERR_PTR(-ENOMEM); | |
2002 | goto bad_wq; | |
2003 | } | |
2004 | ||
2005 | INIT_WORK(&pool->worker, do_worker); | |
905e51b3 | 2006 | INIT_DELAYED_WORK(&pool->waker, do_waker); |
991d9fa0 JT |
2007 | spin_lock_init(&pool->lock); |
2008 | bio_list_init(&pool->deferred_bios); | |
2009 | bio_list_init(&pool->deferred_flush_bios); | |
2010 | INIT_LIST_HEAD(&pool->prepared_mappings); | |
104655fd | 2011 | INIT_LIST_HEAD(&pool->prepared_discards); |
991d9fa0 JT |
2012 | pool->low_water_triggered = 0; |
2013 | pool->no_free_space = 0; | |
2014 | bio_list_init(&pool->retry_on_resume_list); | |
eb2aa48d | 2015 | ds_init(&pool->shared_read_ds); |
104655fd | 2016 | ds_init(&pool->all_io_ds); |
991d9fa0 JT |
2017 | |
2018 | pool->next_mapping = NULL; | |
a24c2569 MS |
2019 | pool->mapping_pool = mempool_create_slab_pool(MAPPING_POOL_SIZE, |
2020 | _new_mapping_cache); | |
991d9fa0 JT |
2021 | if (!pool->mapping_pool) { |
2022 | *error = "Error creating pool's mapping mempool"; | |
2023 | err_p = ERR_PTR(-ENOMEM); | |
2024 | goto bad_mapping_pool; | |
2025 | } | |
2026 | ||
a24c2569 MS |
2027 | pool->endio_hook_pool = mempool_create_slab_pool(ENDIO_HOOK_POOL_SIZE, |
2028 | _endio_hook_cache); | |
991d9fa0 JT |
2029 | if (!pool->endio_hook_pool) { |
2030 | *error = "Error creating pool's endio_hook mempool"; | |
2031 | err_p = ERR_PTR(-ENOMEM); | |
2032 | goto bad_endio_hook_pool; | |
2033 | } | |
2034 | pool->ref_count = 1; | |
905e51b3 | 2035 | pool->last_commit_jiffies = jiffies; |
991d9fa0 JT |
2036 | pool->pool_md = pool_md; |
2037 | pool->md_dev = metadata_dev; | |
2038 | __pool_table_insert(pool); | |
2039 | ||
2040 | return pool; | |
2041 | ||
2042 | bad_endio_hook_pool: | |
2043 | mempool_destroy(pool->mapping_pool); | |
2044 | bad_mapping_pool: | |
2045 | destroy_workqueue(pool->wq); | |
2046 | bad_wq: | |
2047 | dm_kcopyd_client_destroy(pool->copier); | |
2048 | bad_kcopyd_client: | |
2049 | prison_destroy(pool->prison); | |
2050 | bad_prison: | |
2051 | kfree(pool); | |
2052 | bad_pool: | |
2053 | if (dm_pool_metadata_close(pmd)) | |
2054 | DMWARN("%s: dm_pool_metadata_close() failed.", __func__); | |
2055 | ||
2056 | return err_p; | |
2057 | } | |
2058 | ||
2059 | static void __pool_inc(struct pool *pool) | |
2060 | { | |
2061 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
2062 | pool->ref_count++; | |
2063 | } | |
2064 | ||
2065 | static void __pool_dec(struct pool *pool) | |
2066 | { | |
2067 | BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex)); | |
2068 | BUG_ON(!pool->ref_count); | |
2069 | if (!--pool->ref_count) | |
2070 | __pool_destroy(pool); | |
2071 | } | |
2072 | ||
2073 | static struct pool *__pool_find(struct mapped_device *pool_md, | |
2074 | struct block_device *metadata_dev, | |
e49e5829 JT |
2075 | unsigned long block_size, int read_only, |
2076 | char **error, int *created) | |
991d9fa0 JT |
2077 | { |
2078 | struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev); | |
2079 | ||
2080 | if (pool) { | |
f09996c9 MS |
2081 | if (pool->pool_md != pool_md) { |
2082 | *error = "metadata device already in use by a pool"; | |
991d9fa0 | 2083 | return ERR_PTR(-EBUSY); |
f09996c9 | 2084 | } |
991d9fa0 JT |
2085 | __pool_inc(pool); |
2086 | ||
2087 | } else { | |
2088 | pool = __pool_table_lookup(pool_md); | |
2089 | if (pool) { | |
f09996c9 MS |
2090 | if (pool->md_dev != metadata_dev) { |
2091 | *error = "different pool cannot replace a pool"; | |
991d9fa0 | 2092 | return ERR_PTR(-EINVAL); |
f09996c9 | 2093 | } |
991d9fa0 JT |
2094 | __pool_inc(pool); |
2095 | ||
67e2e2b2 | 2096 | } else { |
e49e5829 | 2097 | pool = pool_create(pool_md, metadata_dev, block_size, read_only, error); |
67e2e2b2 JT |
2098 | *created = 1; |
2099 | } | |
991d9fa0 JT |
2100 | } |
2101 | ||
2102 | return pool; | |
2103 | } | |
2104 | ||
2105 | /*---------------------------------------------------------------- | |
2106 | * Pool target methods | |
2107 | *--------------------------------------------------------------*/ | |
2108 | static void pool_dtr(struct dm_target *ti) | |
2109 | { | |
2110 | struct pool_c *pt = ti->private; | |
2111 | ||
2112 | mutex_lock(&dm_thin_pool_table.mutex); | |
2113 | ||
2114 | unbind_control_target(pt->pool, ti); | |
2115 | __pool_dec(pt->pool); | |
2116 | dm_put_device(ti, pt->metadata_dev); | |
2117 | dm_put_device(ti, pt->data_dev); | |
2118 | kfree(pt); | |
2119 | ||
2120 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2121 | } | |
2122 | ||
991d9fa0 JT |
2123 | static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf, |
2124 | struct dm_target *ti) | |
2125 | { | |
2126 | int r; | |
2127 | unsigned argc; | |
2128 | const char *arg_name; | |
2129 | ||
2130 | static struct dm_arg _args[] = { | |
67e2e2b2 | 2131 | {0, 3, "Invalid number of pool feature arguments"}, |
991d9fa0 JT |
2132 | }; |
2133 | ||
2134 | /* | |
2135 | * No feature arguments supplied. | |
2136 | */ | |
2137 | if (!as->argc) | |
2138 | return 0; | |
2139 | ||
2140 | r = dm_read_arg_group(_args, as, &argc, &ti->error); | |
2141 | if (r) | |
2142 | return -EINVAL; | |
2143 | ||
2144 | while (argc && !r) { | |
2145 | arg_name = dm_shift_arg(as); | |
2146 | argc--; | |
2147 | ||
e49e5829 | 2148 | if (!strcasecmp(arg_name, "skip_block_zeroing")) |
9bc142dd | 2149 | pf->zero_new_blocks = false; |
e49e5829 JT |
2150 | |
2151 | else if (!strcasecmp(arg_name, "ignore_discard")) | |
9bc142dd | 2152 | pf->discard_enabled = false; |
e49e5829 JT |
2153 | |
2154 | else if (!strcasecmp(arg_name, "no_discard_passdown")) | |
9bc142dd | 2155 | pf->discard_passdown = false; |
991d9fa0 | 2156 | |
e49e5829 JT |
2157 | else if (!strcasecmp(arg_name, "read_only")) |
2158 | pf->mode = PM_READ_ONLY; | |
2159 | ||
2160 | else { | |
2161 | ti->error = "Unrecognised pool feature requested"; | |
2162 | r = -EINVAL; | |
2163 | break; | |
2164 | } | |
991d9fa0 JT |
2165 | } |
2166 | ||
2167 | return r; | |
2168 | } | |
2169 | ||
2170 | /* | |
2171 | * thin-pool <metadata dev> <data dev> | |
2172 | * <data block size (sectors)> | |
2173 | * <low water mark (blocks)> | |
2174 | * [<#feature args> [<arg>]*] | |
2175 | * | |
2176 | * Optional feature arguments are: | |
2177 | * skip_block_zeroing: skips the zeroing of newly-provisioned blocks. | |
67e2e2b2 JT |
2178 | * ignore_discard: disable discard |
2179 | * no_discard_passdown: don't pass discards down to the data device | |
991d9fa0 JT |
2180 | */ |
2181 | static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
2182 | { | |
67e2e2b2 | 2183 | int r, pool_created = 0; |
991d9fa0 JT |
2184 | struct pool_c *pt; |
2185 | struct pool *pool; | |
2186 | struct pool_features pf; | |
2187 | struct dm_arg_set as; | |
2188 | struct dm_dev *data_dev; | |
2189 | unsigned long block_size; | |
2190 | dm_block_t low_water_blocks; | |
2191 | struct dm_dev *metadata_dev; | |
2192 | sector_t metadata_dev_size; | |
c4a69ecd | 2193 | char b[BDEVNAME_SIZE]; |
991d9fa0 JT |
2194 | |
2195 | /* | |
2196 | * FIXME Remove validation from scope of lock. | |
2197 | */ | |
2198 | mutex_lock(&dm_thin_pool_table.mutex); | |
2199 | ||
2200 | if (argc < 4) { | |
2201 | ti->error = "Invalid argument count"; | |
2202 | r = -EINVAL; | |
2203 | goto out_unlock; | |
2204 | } | |
2205 | as.argc = argc; | |
2206 | as.argv = argv; | |
2207 | ||
2208 | r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &metadata_dev); | |
2209 | if (r) { | |
2210 | ti->error = "Error opening metadata block device"; | |
2211 | goto out_unlock; | |
2212 | } | |
2213 | ||
2214 | metadata_dev_size = i_size_read(metadata_dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
c4a69ecd MS |
2215 | if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING) |
2216 | DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.", | |
2217 | bdevname(metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS); | |
991d9fa0 JT |
2218 | |
2219 | r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &data_dev); | |
2220 | if (r) { | |
2221 | ti->error = "Error getting data device"; | |
2222 | goto out_metadata; | |
2223 | } | |
2224 | ||
2225 | if (kstrtoul(argv[2], 10, &block_size) || !block_size || | |
2226 | block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS || | |
2227 | block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS || | |
55f2b8bd | 2228 | block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) { |
991d9fa0 JT |
2229 | ti->error = "Invalid block size"; |
2230 | r = -EINVAL; | |
2231 | goto out; | |
2232 | } | |
2233 | ||
2234 | if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) { | |
2235 | ti->error = "Invalid low water mark"; | |
2236 | r = -EINVAL; | |
2237 | goto out; | |
2238 | } | |
2239 | ||
2240 | /* | |
2241 | * Set default pool features. | |
2242 | */ | |
67e2e2b2 | 2243 | pool_features_init(&pf); |
991d9fa0 JT |
2244 | |
2245 | dm_consume_args(&as, 4); | |
2246 | r = parse_pool_features(&as, &pf, ti); | |
2247 | if (r) | |
2248 | goto out; | |
2249 | ||
2250 | pt = kzalloc(sizeof(*pt), GFP_KERNEL); | |
2251 | if (!pt) { | |
2252 | r = -ENOMEM; | |
2253 | goto out; | |
2254 | } | |
2255 | ||
2256 | pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev, | |
e49e5829 | 2257 | block_size, pf.mode == PM_READ_ONLY, &ti->error, &pool_created); |
991d9fa0 JT |
2258 | if (IS_ERR(pool)) { |
2259 | r = PTR_ERR(pool); | |
2260 | goto out_free_pt; | |
2261 | } | |
2262 | ||
67e2e2b2 JT |
2263 | /* |
2264 | * 'pool_created' reflects whether this is the first table load. | |
2265 | * Top level discard support is not allowed to be changed after | |
2266 | * initial load. This would require a pool reload to trigger thin | |
2267 | * device changes. | |
2268 | */ | |
2269 | if (!pool_created && pf.discard_enabled != pool->pf.discard_enabled) { | |
2270 | ti->error = "Discard support cannot be disabled once enabled"; | |
2271 | r = -EINVAL; | |
2272 | goto out_flags_changed; | |
2273 | } | |
2274 | ||
55f2b8bd MS |
2275 | /* |
2276 | * The block layer requires discard_granularity to be a power of 2. | |
2277 | */ | |
2278 | if (pf.discard_enabled && !is_power_of_2(block_size)) { | |
2279 | ti->error = "Discard support must be disabled when the block size is not a power of 2"; | |
2280 | r = -EINVAL; | |
2281 | goto out_flags_changed; | |
2282 | } | |
2283 | ||
991d9fa0 JT |
2284 | pt->pool = pool; |
2285 | pt->ti = ti; | |
2286 | pt->metadata_dev = metadata_dev; | |
2287 | pt->data_dev = data_dev; | |
2288 | pt->low_water_blocks = low_water_blocks; | |
0424caa1 | 2289 | pt->adjusted_pf = pt->requested_pf = pf; |
991d9fa0 | 2290 | ti->num_flush_requests = 1; |
9bc142dd | 2291 | |
67e2e2b2 JT |
2292 | /* |
2293 | * Only need to enable discards if the pool should pass | |
2294 | * them down to the data device. The thin device's discard | |
2295 | * processing will cause mappings to be removed from the btree. | |
2296 | */ | |
2297 | if (pf.discard_enabled && pf.discard_passdown) { | |
2298 | ti->num_discard_requests = 1; | |
9bc142dd | 2299 | |
67e2e2b2 JT |
2300 | /* |
2301 | * Setting 'discards_supported' circumvents the normal | |
2302 | * stacking of discard limits (this keeps the pool and | |
2303 | * thin devices' discard limits consistent). | |
2304 | */ | |
0ac55489 | 2305 | ti->discards_supported = true; |
307615a2 | 2306 | ti->discard_zeroes_data_unsupported = true; |
67e2e2b2 | 2307 | } |
991d9fa0 JT |
2308 | ti->private = pt; |
2309 | ||
2310 | pt->callbacks.congested_fn = pool_is_congested; | |
2311 | dm_table_add_target_callbacks(ti->table, &pt->callbacks); | |
2312 | ||
2313 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2314 | ||
2315 | return 0; | |
2316 | ||
67e2e2b2 JT |
2317 | out_flags_changed: |
2318 | __pool_dec(pool); | |
991d9fa0 JT |
2319 | out_free_pt: |
2320 | kfree(pt); | |
2321 | out: | |
2322 | dm_put_device(ti, data_dev); | |
2323 | out_metadata: | |
2324 | dm_put_device(ti, metadata_dev); | |
2325 | out_unlock: | |
2326 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2327 | ||
2328 | return r; | |
2329 | } | |
2330 | ||
2331 | static int pool_map(struct dm_target *ti, struct bio *bio, | |
2332 | union map_info *map_context) | |
2333 | { | |
2334 | int r; | |
2335 | struct pool_c *pt = ti->private; | |
2336 | struct pool *pool = pt->pool; | |
2337 | unsigned long flags; | |
2338 | ||
2339 | /* | |
2340 | * As this is a singleton target, ti->begin is always zero. | |
2341 | */ | |
2342 | spin_lock_irqsave(&pool->lock, flags); | |
2343 | bio->bi_bdev = pt->data_dev->bdev; | |
2344 | r = DM_MAPIO_REMAPPED; | |
2345 | spin_unlock_irqrestore(&pool->lock, flags); | |
2346 | ||
2347 | return r; | |
2348 | } | |
2349 | ||
2350 | /* | |
2351 | * Retrieves the number of blocks of the data device from | |
2352 | * the superblock and compares it to the actual device size, | |
2353 | * thus resizing the data device in case it has grown. | |
2354 | * | |
2355 | * This both copes with opening preallocated data devices in the ctr | |
2356 | * being followed by a resume | |
2357 | * -and- | |
2358 | * calling the resume method individually after userspace has | |
2359 | * grown the data device in reaction to a table event. | |
2360 | */ | |
2361 | static int pool_preresume(struct dm_target *ti) | |
2362 | { | |
2363 | int r; | |
2364 | struct pool_c *pt = ti->private; | |
2365 | struct pool *pool = pt->pool; | |
55f2b8bd MS |
2366 | sector_t data_size = ti->len; |
2367 | dm_block_t sb_data_size; | |
991d9fa0 JT |
2368 | |
2369 | /* | |
2370 | * Take control of the pool object. | |
2371 | */ | |
2372 | r = bind_control_target(pool, ti); | |
2373 | if (r) | |
2374 | return r; | |
2375 | ||
55f2b8bd MS |
2376 | (void) sector_div(data_size, pool->sectors_per_block); |
2377 | ||
991d9fa0 JT |
2378 | r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size); |
2379 | if (r) { | |
2380 | DMERR("failed to retrieve data device size"); | |
2381 | return r; | |
2382 | } | |
2383 | ||
2384 | if (data_size < sb_data_size) { | |
2385 | DMERR("pool target too small, is %llu blocks (expected %llu)", | |
55f2b8bd | 2386 | (unsigned long long)data_size, sb_data_size); |
991d9fa0 JT |
2387 | return -EINVAL; |
2388 | ||
2389 | } else if (data_size > sb_data_size) { | |
2390 | r = dm_pool_resize_data_dev(pool->pmd, data_size); | |
2391 | if (r) { | |
2392 | DMERR("failed to resize data device"); | |
e49e5829 JT |
2393 | /* FIXME Stricter than necessary: Rollback transaction instead here */ |
2394 | set_pool_mode(pool, PM_READ_ONLY); | |
991d9fa0 JT |
2395 | return r; |
2396 | } | |
2397 | ||
e49e5829 | 2398 | (void) commit_or_fallback(pool); |
991d9fa0 JT |
2399 | } |
2400 | ||
2401 | return 0; | |
2402 | } | |
2403 | ||
2404 | static void pool_resume(struct dm_target *ti) | |
2405 | { | |
2406 | struct pool_c *pt = ti->private; | |
2407 | struct pool *pool = pt->pool; | |
2408 | unsigned long flags; | |
2409 | ||
2410 | spin_lock_irqsave(&pool->lock, flags); | |
2411 | pool->low_water_triggered = 0; | |
2412 | pool->no_free_space = 0; | |
2413 | __requeue_bios(pool); | |
2414 | spin_unlock_irqrestore(&pool->lock, flags); | |
2415 | ||
905e51b3 | 2416 | do_waker(&pool->waker.work); |
991d9fa0 JT |
2417 | } |
2418 | ||
2419 | static void pool_postsuspend(struct dm_target *ti) | |
2420 | { | |
991d9fa0 JT |
2421 | struct pool_c *pt = ti->private; |
2422 | struct pool *pool = pt->pool; | |
2423 | ||
905e51b3 | 2424 | cancel_delayed_work(&pool->waker); |
991d9fa0 | 2425 | flush_workqueue(pool->wq); |
e49e5829 | 2426 | (void) commit_or_fallback(pool); |
991d9fa0 JT |
2427 | } |
2428 | ||
2429 | static int check_arg_count(unsigned argc, unsigned args_required) | |
2430 | { | |
2431 | if (argc != args_required) { | |
2432 | DMWARN("Message received with %u arguments instead of %u.", | |
2433 | argc, args_required); | |
2434 | return -EINVAL; | |
2435 | } | |
2436 | ||
2437 | return 0; | |
2438 | } | |
2439 | ||
2440 | static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning) | |
2441 | { | |
2442 | if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) && | |
2443 | *dev_id <= MAX_DEV_ID) | |
2444 | return 0; | |
2445 | ||
2446 | if (warning) | |
2447 | DMWARN("Message received with invalid device id: %s", arg); | |
2448 | ||
2449 | return -EINVAL; | |
2450 | } | |
2451 | ||
2452 | static int process_create_thin_mesg(unsigned argc, char **argv, struct pool *pool) | |
2453 | { | |
2454 | dm_thin_id dev_id; | |
2455 | int r; | |
2456 | ||
2457 | r = check_arg_count(argc, 2); | |
2458 | if (r) | |
2459 | return r; | |
2460 | ||
2461 | r = read_dev_id(argv[1], &dev_id, 1); | |
2462 | if (r) | |
2463 | return r; | |
2464 | ||
2465 | r = dm_pool_create_thin(pool->pmd, dev_id); | |
2466 | if (r) { | |
2467 | DMWARN("Creation of new thinly-provisioned device with id %s failed.", | |
2468 | argv[1]); | |
2469 | return r; | |
2470 | } | |
2471 | ||
2472 | return 0; | |
2473 | } | |
2474 | ||
2475 | static int process_create_snap_mesg(unsigned argc, char **argv, struct pool *pool) | |
2476 | { | |
2477 | dm_thin_id dev_id; | |
2478 | dm_thin_id origin_dev_id; | |
2479 | int r; | |
2480 | ||
2481 | r = check_arg_count(argc, 3); | |
2482 | if (r) | |
2483 | return r; | |
2484 | ||
2485 | r = read_dev_id(argv[1], &dev_id, 1); | |
2486 | if (r) | |
2487 | return r; | |
2488 | ||
2489 | r = read_dev_id(argv[2], &origin_dev_id, 1); | |
2490 | if (r) | |
2491 | return r; | |
2492 | ||
2493 | r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id); | |
2494 | if (r) { | |
2495 | DMWARN("Creation of new snapshot %s of device %s failed.", | |
2496 | argv[1], argv[2]); | |
2497 | return r; | |
2498 | } | |
2499 | ||
2500 | return 0; | |
2501 | } | |
2502 | ||
2503 | static int process_delete_mesg(unsigned argc, char **argv, struct pool *pool) | |
2504 | { | |
2505 | dm_thin_id dev_id; | |
2506 | int r; | |
2507 | ||
2508 | r = check_arg_count(argc, 2); | |
2509 | if (r) | |
2510 | return r; | |
2511 | ||
2512 | r = read_dev_id(argv[1], &dev_id, 1); | |
2513 | if (r) | |
2514 | return r; | |
2515 | ||
2516 | r = dm_pool_delete_thin_device(pool->pmd, dev_id); | |
2517 | if (r) | |
2518 | DMWARN("Deletion of thin device %s failed.", argv[1]); | |
2519 | ||
2520 | return r; | |
2521 | } | |
2522 | ||
2523 | static int process_set_transaction_id_mesg(unsigned argc, char **argv, struct pool *pool) | |
2524 | { | |
2525 | dm_thin_id old_id, new_id; | |
2526 | int r; | |
2527 | ||
2528 | r = check_arg_count(argc, 3); | |
2529 | if (r) | |
2530 | return r; | |
2531 | ||
2532 | if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) { | |
2533 | DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]); | |
2534 | return -EINVAL; | |
2535 | } | |
2536 | ||
2537 | if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) { | |
2538 | DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]); | |
2539 | return -EINVAL; | |
2540 | } | |
2541 | ||
2542 | r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id); | |
2543 | if (r) { | |
2544 | DMWARN("Failed to change transaction id from %s to %s.", | |
2545 | argv[1], argv[2]); | |
2546 | return r; | |
2547 | } | |
2548 | ||
2549 | return 0; | |
2550 | } | |
2551 | ||
cc8394d8 JT |
2552 | static int process_reserve_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool) |
2553 | { | |
2554 | int r; | |
2555 | ||
2556 | r = check_arg_count(argc, 1); | |
2557 | if (r) | |
2558 | return r; | |
2559 | ||
e49e5829 | 2560 | (void) commit_or_fallback(pool); |
0d200aef | 2561 | |
cc8394d8 JT |
2562 | r = dm_pool_reserve_metadata_snap(pool->pmd); |
2563 | if (r) | |
2564 | DMWARN("reserve_metadata_snap message failed."); | |
2565 | ||
2566 | return r; | |
2567 | } | |
2568 | ||
2569 | static int process_release_metadata_snap_mesg(unsigned argc, char **argv, struct pool *pool) | |
2570 | { | |
2571 | int r; | |
2572 | ||
2573 | r = check_arg_count(argc, 1); | |
2574 | if (r) | |
2575 | return r; | |
2576 | ||
2577 | r = dm_pool_release_metadata_snap(pool->pmd); | |
2578 | if (r) | |
2579 | DMWARN("release_metadata_snap message failed."); | |
2580 | ||
2581 | return r; | |
2582 | } | |
2583 | ||
991d9fa0 JT |
2584 | /* |
2585 | * Messages supported: | |
2586 | * create_thin <dev_id> | |
2587 | * create_snap <dev_id> <origin_id> | |
2588 | * delete <dev_id> | |
2589 | * trim <dev_id> <new_size_in_sectors> | |
2590 | * set_transaction_id <current_trans_id> <new_trans_id> | |
cc8394d8 JT |
2591 | * reserve_metadata_snap |
2592 | * release_metadata_snap | |
991d9fa0 JT |
2593 | */ |
2594 | static int pool_message(struct dm_target *ti, unsigned argc, char **argv) | |
2595 | { | |
2596 | int r = -EINVAL; | |
2597 | struct pool_c *pt = ti->private; | |
2598 | struct pool *pool = pt->pool; | |
2599 | ||
2600 | if (!strcasecmp(argv[0], "create_thin")) | |
2601 | r = process_create_thin_mesg(argc, argv, pool); | |
2602 | ||
2603 | else if (!strcasecmp(argv[0], "create_snap")) | |
2604 | r = process_create_snap_mesg(argc, argv, pool); | |
2605 | ||
2606 | else if (!strcasecmp(argv[0], "delete")) | |
2607 | r = process_delete_mesg(argc, argv, pool); | |
2608 | ||
2609 | else if (!strcasecmp(argv[0], "set_transaction_id")) | |
2610 | r = process_set_transaction_id_mesg(argc, argv, pool); | |
2611 | ||
cc8394d8 JT |
2612 | else if (!strcasecmp(argv[0], "reserve_metadata_snap")) |
2613 | r = process_reserve_metadata_snap_mesg(argc, argv, pool); | |
2614 | ||
2615 | else if (!strcasecmp(argv[0], "release_metadata_snap")) | |
2616 | r = process_release_metadata_snap_mesg(argc, argv, pool); | |
2617 | ||
991d9fa0 JT |
2618 | else |
2619 | DMWARN("Unrecognised thin pool target message received: %s", argv[0]); | |
2620 | ||
e49e5829 JT |
2621 | if (!r) |
2622 | (void) commit_or_fallback(pool); | |
991d9fa0 JT |
2623 | |
2624 | return r; | |
2625 | } | |
2626 | ||
e49e5829 JT |
2627 | static void emit_flags(struct pool_features *pf, char *result, |
2628 | unsigned sz, unsigned maxlen) | |
2629 | { | |
2630 | unsigned count = !pf->zero_new_blocks + !pf->discard_enabled + | |
2631 | !pf->discard_passdown + (pf->mode == PM_READ_ONLY); | |
2632 | DMEMIT("%u ", count); | |
2633 | ||
2634 | if (!pf->zero_new_blocks) | |
2635 | DMEMIT("skip_block_zeroing "); | |
2636 | ||
2637 | if (!pf->discard_enabled) | |
2638 | DMEMIT("ignore_discard "); | |
2639 | ||
2640 | if (!pf->discard_passdown) | |
2641 | DMEMIT("no_discard_passdown "); | |
2642 | ||
2643 | if (pf->mode == PM_READ_ONLY) | |
2644 | DMEMIT("read_only "); | |
2645 | } | |
2646 | ||
991d9fa0 JT |
2647 | /* |
2648 | * Status line is: | |
2649 | * <transaction id> <used metadata sectors>/<total metadata sectors> | |
2650 | * <used data sectors>/<total data sectors> <held metadata root> | |
2651 | */ | |
2652 | static int pool_status(struct dm_target *ti, status_type_t type, | |
1f4e0ff0 | 2653 | unsigned status_flags, char *result, unsigned maxlen) |
991d9fa0 | 2654 | { |
e49e5829 | 2655 | int r; |
991d9fa0 JT |
2656 | unsigned sz = 0; |
2657 | uint64_t transaction_id; | |
2658 | dm_block_t nr_free_blocks_data; | |
2659 | dm_block_t nr_free_blocks_metadata; | |
2660 | dm_block_t nr_blocks_data; | |
2661 | dm_block_t nr_blocks_metadata; | |
2662 | dm_block_t held_root; | |
2663 | char buf[BDEVNAME_SIZE]; | |
2664 | char buf2[BDEVNAME_SIZE]; | |
2665 | struct pool_c *pt = ti->private; | |
2666 | struct pool *pool = pt->pool; | |
2667 | ||
2668 | switch (type) { | |
2669 | case STATUSTYPE_INFO: | |
e49e5829 JT |
2670 | if (get_pool_mode(pool) == PM_FAIL) { |
2671 | DMEMIT("Fail"); | |
2672 | break; | |
2673 | } | |
2674 | ||
1f4e0ff0 AK |
2675 | /* Commit to ensure statistics aren't out-of-date */ |
2676 | if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) | |
2677 | (void) commit_or_fallback(pool); | |
2678 | ||
991d9fa0 JT |
2679 | r = dm_pool_get_metadata_transaction_id(pool->pmd, |
2680 | &transaction_id); | |
2681 | if (r) | |
2682 | return r; | |
2683 | ||
2684 | r = dm_pool_get_free_metadata_block_count(pool->pmd, | |
2685 | &nr_free_blocks_metadata); | |
2686 | if (r) | |
2687 | return r; | |
2688 | ||
2689 | r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata); | |
2690 | if (r) | |
2691 | return r; | |
2692 | ||
2693 | r = dm_pool_get_free_block_count(pool->pmd, | |
2694 | &nr_free_blocks_data); | |
2695 | if (r) | |
2696 | return r; | |
2697 | ||
2698 | r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data); | |
2699 | if (r) | |
2700 | return r; | |
2701 | ||
cc8394d8 | 2702 | r = dm_pool_get_metadata_snap(pool->pmd, &held_root); |
991d9fa0 JT |
2703 | if (r) |
2704 | return r; | |
2705 | ||
2706 | DMEMIT("%llu %llu/%llu %llu/%llu ", | |
2707 | (unsigned long long)transaction_id, | |
2708 | (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), | |
2709 | (unsigned long long)nr_blocks_metadata, | |
2710 | (unsigned long long)(nr_blocks_data - nr_free_blocks_data), | |
2711 | (unsigned long long)nr_blocks_data); | |
2712 | ||
2713 | if (held_root) | |
e49e5829 JT |
2714 | DMEMIT("%llu ", held_root); |
2715 | else | |
2716 | DMEMIT("- "); | |
2717 | ||
2718 | if (pool->pf.mode == PM_READ_ONLY) | |
2719 | DMEMIT("ro "); | |
991d9fa0 | 2720 | else |
e49e5829 JT |
2721 | DMEMIT("rw "); |
2722 | ||
2723 | if (pool->pf.discard_enabled && pool->pf.discard_passdown) | |
2724 | DMEMIT("discard_passdown"); | |
2725 | else | |
2726 | DMEMIT("no_discard_passdown"); | |
991d9fa0 JT |
2727 | |
2728 | break; | |
2729 | ||
2730 | case STATUSTYPE_TABLE: | |
2731 | DMEMIT("%s %s %lu %llu ", | |
2732 | format_dev_t(buf, pt->metadata_dev->bdev->bd_dev), | |
2733 | format_dev_t(buf2, pt->data_dev->bdev->bd_dev), | |
2734 | (unsigned long)pool->sectors_per_block, | |
2735 | (unsigned long long)pt->low_water_blocks); | |
0424caa1 | 2736 | emit_flags(&pt->requested_pf, result, sz, maxlen); |
991d9fa0 JT |
2737 | break; |
2738 | } | |
2739 | ||
2740 | return 0; | |
2741 | } | |
2742 | ||
2743 | static int pool_iterate_devices(struct dm_target *ti, | |
2744 | iterate_devices_callout_fn fn, void *data) | |
2745 | { | |
2746 | struct pool_c *pt = ti->private; | |
2747 | ||
2748 | return fn(ti, pt->data_dev, 0, ti->len, data); | |
2749 | } | |
2750 | ||
2751 | static int pool_merge(struct dm_target *ti, struct bvec_merge_data *bvm, | |
2752 | struct bio_vec *biovec, int max_size) | |
2753 | { | |
2754 | struct pool_c *pt = ti->private; | |
2755 | struct request_queue *q = bdev_get_queue(pt->data_dev->bdev); | |
2756 | ||
2757 | if (!q->merge_bvec_fn) | |
2758 | return max_size; | |
2759 | ||
2760 | bvm->bi_bdev = pt->data_dev->bdev; | |
2761 | ||
2762 | return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); | |
2763 | } | |
2764 | ||
0424caa1 | 2765 | static void set_discard_limits(struct pool_c *pt, struct queue_limits *limits) |
104655fd | 2766 | { |
0424caa1 MS |
2767 | struct pool *pool = pt->pool; |
2768 | struct queue_limits *data_limits; | |
2769 | ||
104655fd JT |
2770 | limits->max_discard_sectors = pool->sectors_per_block; |
2771 | ||
2772 | /* | |
0424caa1 | 2773 | * discard_granularity is just a hint, and not enforced. |
104655fd | 2774 | */ |
0424caa1 MS |
2775 | if (pt->adjusted_pf.discard_passdown) { |
2776 | data_limits = &bdev_get_queue(pt->data_dev->bdev)->limits; | |
2777 | limits->discard_granularity = data_limits->discard_granularity; | |
2778 | } else | |
2779 | limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT; | |
104655fd JT |
2780 | } |
2781 | ||
991d9fa0 JT |
2782 | static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits) |
2783 | { | |
2784 | struct pool_c *pt = ti->private; | |
2785 | struct pool *pool = pt->pool; | |
2786 | ||
2787 | blk_limits_io_min(limits, 0); | |
2788 | blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT); | |
0424caa1 MS |
2789 | |
2790 | /* | |
2791 | * pt->adjusted_pf is a staging area for the actual features to use. | |
2792 | * They get transferred to the live pool in bind_control_target() | |
2793 | * called from pool_preresume(). | |
2794 | */ | |
2795 | if (!pt->adjusted_pf.discard_enabled) | |
2796 | return; | |
2797 | ||
2798 | disable_passdown_if_not_supported(pt); | |
2799 | ||
2800 | set_discard_limits(pt, limits); | |
991d9fa0 JT |
2801 | } |
2802 | ||
2803 | static struct target_type pool_target = { | |
2804 | .name = "thin-pool", | |
2805 | .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE | | |
2806 | DM_TARGET_IMMUTABLE, | |
0424caa1 | 2807 | .version = {1, 4, 0}, |
991d9fa0 JT |
2808 | .module = THIS_MODULE, |
2809 | .ctr = pool_ctr, | |
2810 | .dtr = pool_dtr, | |
2811 | .map = pool_map, | |
2812 | .postsuspend = pool_postsuspend, | |
2813 | .preresume = pool_preresume, | |
2814 | .resume = pool_resume, | |
2815 | .message = pool_message, | |
2816 | .status = pool_status, | |
2817 | .merge = pool_merge, | |
2818 | .iterate_devices = pool_iterate_devices, | |
2819 | .io_hints = pool_io_hints, | |
2820 | }; | |
2821 | ||
2822 | /*---------------------------------------------------------------- | |
2823 | * Thin target methods | |
2824 | *--------------------------------------------------------------*/ | |
2825 | static void thin_dtr(struct dm_target *ti) | |
2826 | { | |
2827 | struct thin_c *tc = ti->private; | |
2828 | ||
2829 | mutex_lock(&dm_thin_pool_table.mutex); | |
2830 | ||
2831 | __pool_dec(tc->pool); | |
2832 | dm_pool_close_thin_device(tc->td); | |
2833 | dm_put_device(ti, tc->pool_dev); | |
2dd9c257 JT |
2834 | if (tc->origin_dev) |
2835 | dm_put_device(ti, tc->origin_dev); | |
991d9fa0 JT |
2836 | kfree(tc); |
2837 | ||
2838 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2839 | } | |
2840 | ||
2841 | /* | |
2842 | * Thin target parameters: | |
2843 | * | |
2dd9c257 | 2844 | * <pool_dev> <dev_id> [origin_dev] |
991d9fa0 JT |
2845 | * |
2846 | * pool_dev: the path to the pool (eg, /dev/mapper/my_pool) | |
2847 | * dev_id: the internal device identifier | |
2dd9c257 | 2848 | * origin_dev: a device external to the pool that should act as the origin |
67e2e2b2 JT |
2849 | * |
2850 | * If the pool device has discards disabled, they get disabled for the thin | |
2851 | * device as well. | |
991d9fa0 JT |
2852 | */ |
2853 | static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
2854 | { | |
2855 | int r; | |
2856 | struct thin_c *tc; | |
2dd9c257 | 2857 | struct dm_dev *pool_dev, *origin_dev; |
991d9fa0 JT |
2858 | struct mapped_device *pool_md; |
2859 | ||
2860 | mutex_lock(&dm_thin_pool_table.mutex); | |
2861 | ||
2dd9c257 | 2862 | if (argc != 2 && argc != 3) { |
991d9fa0 JT |
2863 | ti->error = "Invalid argument count"; |
2864 | r = -EINVAL; | |
2865 | goto out_unlock; | |
2866 | } | |
2867 | ||
2868 | tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL); | |
2869 | if (!tc) { | |
2870 | ti->error = "Out of memory"; | |
2871 | r = -ENOMEM; | |
2872 | goto out_unlock; | |
2873 | } | |
2874 | ||
2dd9c257 JT |
2875 | if (argc == 3) { |
2876 | r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev); | |
2877 | if (r) { | |
2878 | ti->error = "Error opening origin device"; | |
2879 | goto bad_origin_dev; | |
2880 | } | |
2881 | tc->origin_dev = origin_dev; | |
2882 | } | |
2883 | ||
991d9fa0 JT |
2884 | r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev); |
2885 | if (r) { | |
2886 | ti->error = "Error opening pool device"; | |
2887 | goto bad_pool_dev; | |
2888 | } | |
2889 | tc->pool_dev = pool_dev; | |
2890 | ||
2891 | if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) { | |
2892 | ti->error = "Invalid device id"; | |
2893 | r = -EINVAL; | |
2894 | goto bad_common; | |
2895 | } | |
2896 | ||
2897 | pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev); | |
2898 | if (!pool_md) { | |
2899 | ti->error = "Couldn't get pool mapped device"; | |
2900 | r = -EINVAL; | |
2901 | goto bad_common; | |
2902 | } | |
2903 | ||
2904 | tc->pool = __pool_table_lookup(pool_md); | |
2905 | if (!tc->pool) { | |
2906 | ti->error = "Couldn't find pool object"; | |
2907 | r = -EINVAL; | |
2908 | goto bad_pool_lookup; | |
2909 | } | |
2910 | __pool_inc(tc->pool); | |
2911 | ||
e49e5829 JT |
2912 | if (get_pool_mode(tc->pool) == PM_FAIL) { |
2913 | ti->error = "Couldn't open thin device, Pool is in fail mode"; | |
2914 | goto bad_thin_open; | |
2915 | } | |
2916 | ||
991d9fa0 JT |
2917 | r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td); |
2918 | if (r) { | |
2919 | ti->error = "Couldn't open thin internal device"; | |
2920 | goto bad_thin_open; | |
2921 | } | |
2922 | ||
542f9038 MS |
2923 | r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block); |
2924 | if (r) | |
2925 | goto bad_thin_open; | |
2926 | ||
991d9fa0 | 2927 | ti->num_flush_requests = 1; |
16ad3d10 | 2928 | ti->flush_supported = true; |
67e2e2b2 JT |
2929 | |
2930 | /* In case the pool supports discards, pass them on. */ | |
2931 | if (tc->pool->pf.discard_enabled) { | |
0ac55489 | 2932 | ti->discards_supported = true; |
67e2e2b2 | 2933 | ti->num_discard_requests = 1; |
0ac55489 | 2934 | ti->discard_zeroes_data_unsupported = true; |
49296309 | 2935 | /* Discard requests must be split on a block boundary */ |
0ac55489 | 2936 | ti->split_discard_requests = true; |
67e2e2b2 | 2937 | } |
991d9fa0 JT |
2938 | |
2939 | dm_put(pool_md); | |
2940 | ||
2941 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2942 | ||
2943 | return 0; | |
2944 | ||
2945 | bad_thin_open: | |
2946 | __pool_dec(tc->pool); | |
2947 | bad_pool_lookup: | |
2948 | dm_put(pool_md); | |
2949 | bad_common: | |
2950 | dm_put_device(ti, tc->pool_dev); | |
2951 | bad_pool_dev: | |
2dd9c257 JT |
2952 | if (tc->origin_dev) |
2953 | dm_put_device(ti, tc->origin_dev); | |
2954 | bad_origin_dev: | |
991d9fa0 JT |
2955 | kfree(tc); |
2956 | out_unlock: | |
2957 | mutex_unlock(&dm_thin_pool_table.mutex); | |
2958 | ||
2959 | return r; | |
2960 | } | |
2961 | ||
2962 | static int thin_map(struct dm_target *ti, struct bio *bio, | |
2963 | union map_info *map_context) | |
2964 | { | |
6efd6e83 | 2965 | bio->bi_sector = dm_target_offset(ti, bio->bi_sector); |
991d9fa0 JT |
2966 | |
2967 | return thin_bio_map(ti, bio, map_context); | |
2968 | } | |
2969 | ||
eb2aa48d JT |
2970 | static int thin_endio(struct dm_target *ti, |
2971 | struct bio *bio, int err, | |
2972 | union map_info *map_context) | |
2973 | { | |
2974 | unsigned long flags; | |
a24c2569 | 2975 | struct dm_thin_endio_hook *h = map_context->ptr; |
eb2aa48d | 2976 | struct list_head work; |
a24c2569 | 2977 | struct dm_thin_new_mapping *m, *tmp; |
eb2aa48d JT |
2978 | struct pool *pool = h->tc->pool; |
2979 | ||
2980 | if (h->shared_read_entry) { | |
2981 | INIT_LIST_HEAD(&work); | |
2982 | ds_dec(h->shared_read_entry, &work); | |
2983 | ||
2984 | spin_lock_irqsave(&pool->lock, flags); | |
2985 | list_for_each_entry_safe(m, tmp, &work, list) { | |
2986 | list_del(&m->list); | |
2987 | m->quiesced = 1; | |
2988 | __maybe_add_mapping(m); | |
2989 | } | |
2990 | spin_unlock_irqrestore(&pool->lock, flags); | |
2991 | } | |
2992 | ||
104655fd JT |
2993 | if (h->all_io_entry) { |
2994 | INIT_LIST_HEAD(&work); | |
2995 | ds_dec(h->all_io_entry, &work); | |
c3a0ce2e | 2996 | spin_lock_irqsave(&pool->lock, flags); |
104655fd JT |
2997 | list_for_each_entry_safe(m, tmp, &work, list) |
2998 | list_add(&m->list, &pool->prepared_discards); | |
c3a0ce2e | 2999 | spin_unlock_irqrestore(&pool->lock, flags); |
104655fd JT |
3000 | } |
3001 | ||
eb2aa48d JT |
3002 | mempool_free(h, pool->endio_hook_pool); |
3003 | ||
3004 | return 0; | |
3005 | } | |
3006 | ||
991d9fa0 JT |
3007 | static void thin_postsuspend(struct dm_target *ti) |
3008 | { | |
3009 | if (dm_noflush_suspending(ti)) | |
3010 | requeue_io((struct thin_c *)ti->private); | |
3011 | } | |
3012 | ||
3013 | /* | |
3014 | * <nr mapped sectors> <highest mapped sector> | |
3015 | */ | |
3016 | static int thin_status(struct dm_target *ti, status_type_t type, | |
1f4e0ff0 | 3017 | unsigned status_flags, char *result, unsigned maxlen) |
991d9fa0 JT |
3018 | { |
3019 | int r; | |
3020 | ssize_t sz = 0; | |
3021 | dm_block_t mapped, highest; | |
3022 | char buf[BDEVNAME_SIZE]; | |
3023 | struct thin_c *tc = ti->private; | |
3024 | ||
e49e5829 JT |
3025 | if (get_pool_mode(tc->pool) == PM_FAIL) { |
3026 | DMEMIT("Fail"); | |
3027 | return 0; | |
3028 | } | |
3029 | ||
991d9fa0 JT |
3030 | if (!tc->td) |
3031 | DMEMIT("-"); | |
3032 | else { | |
3033 | switch (type) { | |
3034 | case STATUSTYPE_INFO: | |
3035 | r = dm_thin_get_mapped_count(tc->td, &mapped); | |
3036 | if (r) | |
3037 | return r; | |
3038 | ||
3039 | r = dm_thin_get_highest_mapped_block(tc->td, &highest); | |
3040 | if (r < 0) | |
3041 | return r; | |
3042 | ||
3043 | DMEMIT("%llu ", mapped * tc->pool->sectors_per_block); | |
3044 | if (r) | |
3045 | DMEMIT("%llu", ((highest + 1) * | |
3046 | tc->pool->sectors_per_block) - 1); | |
3047 | else | |
3048 | DMEMIT("-"); | |
3049 | break; | |
3050 | ||
3051 | case STATUSTYPE_TABLE: | |
3052 | DMEMIT("%s %lu", | |
3053 | format_dev_t(buf, tc->pool_dev->bdev->bd_dev), | |
3054 | (unsigned long) tc->dev_id); | |
2dd9c257 JT |
3055 | if (tc->origin_dev) |
3056 | DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev)); | |
991d9fa0 JT |
3057 | break; |
3058 | } | |
3059 | } | |
3060 | ||
3061 | return 0; | |
3062 | } | |
3063 | ||
3064 | static int thin_iterate_devices(struct dm_target *ti, | |
3065 | iterate_devices_callout_fn fn, void *data) | |
3066 | { | |
55f2b8bd | 3067 | sector_t blocks; |
991d9fa0 | 3068 | struct thin_c *tc = ti->private; |
55f2b8bd | 3069 | struct pool *pool = tc->pool; |
991d9fa0 JT |
3070 | |
3071 | /* | |
3072 | * We can't call dm_pool_get_data_dev_size() since that blocks. So | |
3073 | * we follow a more convoluted path through to the pool's target. | |
3074 | */ | |
55f2b8bd | 3075 | if (!pool->ti) |
991d9fa0 JT |
3076 | return 0; /* nothing is bound */ |
3077 | ||
55f2b8bd MS |
3078 | blocks = pool->ti->len; |
3079 | (void) sector_div(blocks, pool->sectors_per_block); | |
991d9fa0 | 3080 | if (blocks) |
55f2b8bd | 3081 | return fn(ti, tc->pool_dev, 0, pool->sectors_per_block * blocks, data); |
991d9fa0 JT |
3082 | |
3083 | return 0; | |
3084 | } | |
3085 | ||
0424caa1 MS |
3086 | /* |
3087 | * A thin device always inherits its queue limits from its pool. | |
3088 | */ | |
991d9fa0 JT |
3089 | static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits) |
3090 | { | |
3091 | struct thin_c *tc = ti->private; | |
3092 | ||
0424caa1 | 3093 | *limits = bdev_get_queue(tc->pool_dev->bdev)->limits; |
991d9fa0 JT |
3094 | } |
3095 | ||
3096 | static struct target_type thin_target = { | |
3097 | .name = "thin", | |
0424caa1 | 3098 | .version = {1, 4, 0}, |
991d9fa0 JT |
3099 | .module = THIS_MODULE, |
3100 | .ctr = thin_ctr, | |
3101 | .dtr = thin_dtr, | |
3102 | .map = thin_map, | |
eb2aa48d | 3103 | .end_io = thin_endio, |
991d9fa0 JT |
3104 | .postsuspend = thin_postsuspend, |
3105 | .status = thin_status, | |
3106 | .iterate_devices = thin_iterate_devices, | |
3107 | .io_hints = thin_io_hints, | |
3108 | }; | |
3109 | ||
3110 | /*----------------------------------------------------------------*/ | |
3111 | ||
3112 | static int __init dm_thin_init(void) | |
3113 | { | |
3114 | int r; | |
3115 | ||
3116 | pool_table_init(); | |
3117 | ||
3118 | r = dm_register_target(&thin_target); | |
3119 | if (r) | |
3120 | return r; | |
3121 | ||
3122 | r = dm_register_target(&pool_target); | |
3123 | if (r) | |
a24c2569 MS |
3124 | goto bad_pool_target; |
3125 | ||
3126 | r = -ENOMEM; | |
3127 | ||
3128 | _cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0); | |
3129 | if (!_cell_cache) | |
3130 | goto bad_cell_cache; | |
3131 | ||
3132 | _new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0); | |
3133 | if (!_new_mapping_cache) | |
3134 | goto bad_new_mapping_cache; | |
3135 | ||
3136 | _endio_hook_cache = KMEM_CACHE(dm_thin_endio_hook, 0); | |
3137 | if (!_endio_hook_cache) | |
3138 | goto bad_endio_hook_cache; | |
3139 | ||
3140 | return 0; | |
3141 | ||
3142 | bad_endio_hook_cache: | |
3143 | kmem_cache_destroy(_new_mapping_cache); | |
3144 | bad_new_mapping_cache: | |
3145 | kmem_cache_destroy(_cell_cache); | |
3146 | bad_cell_cache: | |
3147 | dm_unregister_target(&pool_target); | |
3148 | bad_pool_target: | |
3149 | dm_unregister_target(&thin_target); | |
991d9fa0 JT |
3150 | |
3151 | return r; | |
3152 | } | |
3153 | ||
3154 | static void dm_thin_exit(void) | |
3155 | { | |
3156 | dm_unregister_target(&thin_target); | |
3157 | dm_unregister_target(&pool_target); | |
a24c2569 MS |
3158 | |
3159 | kmem_cache_destroy(_cell_cache); | |
3160 | kmem_cache_destroy(_new_mapping_cache); | |
3161 | kmem_cache_destroy(_endio_hook_cache); | |
991d9fa0 JT |
3162 | } |
3163 | ||
3164 | module_init(dm_thin_init); | |
3165 | module_exit(dm_thin_exit); | |
3166 | ||
7cab8bf1 | 3167 | MODULE_DESCRIPTION(DM_NAME " thin provisioning target"); |
991d9fa0 JT |
3168 | MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>"); |
3169 | MODULE_LICENSE("GPL"); |