Commit | Line | Data |
---|---|---|
c6b4fcba JT |
1 | /* |
2 | * Copyright (C) 2012 Red Hat. All rights reserved. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7 | #include "dm.h" | |
b29d4986 | 8 | #include "dm-bio-prison-v2.h" |
b844fe69 | 9 | #include "dm-bio-record.h" |
c6b4fcba JT |
10 | #include "dm-cache-metadata.h" |
11 | ||
12 | #include <linux/dm-io.h> | |
13 | #include <linux/dm-kcopyd.h> | |
0f30af98 | 14 | #include <linux/jiffies.h> |
c6b4fcba JT |
15 | #include <linux/init.h> |
16 | #include <linux/mempool.h> | |
17 | #include <linux/module.h> | |
b29d4986 | 18 | #include <linux/rwsem.h> |
c6b4fcba JT |
19 | #include <linux/slab.h> |
20 | #include <linux/vmalloc.h> | |
21 | ||
22 | #define DM_MSG_PREFIX "cache" | |
23 | ||
24 | DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(cache_copy_throttle, | |
25 | "A percentage of time allocated for copying to and/or from cache"); | |
26 | ||
27 | /*----------------------------------------------------------------*/ | |
28 | ||
b29d4986 JT |
29 | /* |
30 | * Glossary: | |
31 | * | |
32 | * oblock: index of an origin block | |
33 | * cblock: index of a cache block | |
34 | * promotion: movement of a block from origin to cache | |
35 | * demotion: movement of a block from cache to origin | |
36 | * migration: movement of a block between the origin and cache device, | |
37 | * either direction | |
38 | */ | |
39 | ||
40 | /*----------------------------------------------------------------*/ | |
77289d32 JT |
41 | |
42 | struct io_tracker { | |
43 | spinlock_t lock; | |
44 | ||
45 | /* | |
46 | * Sectors of in-flight IO. | |
47 | */ | |
48 | sector_t in_flight; | |
49 | ||
50 | /* | |
51 | * The time, in jiffies, when this device became idle (if it is | |
52 | * indeed idle). | |
53 | */ | |
54 | unsigned long idle_time; | |
55 | unsigned long last_update_time; | |
56 | }; | |
57 | ||
58 | static void iot_init(struct io_tracker *iot) | |
59 | { | |
60 | spin_lock_init(&iot->lock); | |
61 | iot->in_flight = 0ul; | |
62 | iot->idle_time = 0ul; | |
63 | iot->last_update_time = jiffies; | |
64 | } | |
65 | ||
66 | static bool __iot_idle_for(struct io_tracker *iot, unsigned long jifs) | |
67 | { | |
68 | if (iot->in_flight) | |
69 | return false; | |
70 | ||
71 | return time_after(jiffies, iot->idle_time + jifs); | |
72 | } | |
73 | ||
74 | static bool iot_idle_for(struct io_tracker *iot, unsigned long jifs) | |
75 | { | |
76 | bool r; | |
77 | unsigned long flags; | |
78 | ||
79 | spin_lock_irqsave(&iot->lock, flags); | |
80 | r = __iot_idle_for(iot, jifs); | |
81 | spin_unlock_irqrestore(&iot->lock, flags); | |
82 | ||
83 | return r; | |
84 | } | |
85 | ||
86 | static void iot_io_begin(struct io_tracker *iot, sector_t len) | |
87 | { | |
88 | unsigned long flags; | |
89 | ||
90 | spin_lock_irqsave(&iot->lock, flags); | |
91 | iot->in_flight += len; | |
92 | spin_unlock_irqrestore(&iot->lock, flags); | |
93 | } | |
94 | ||
95 | static void __iot_io_end(struct io_tracker *iot, sector_t len) | |
96 | { | |
072792dc JT |
97 | if (!len) |
98 | return; | |
99 | ||
77289d32 JT |
100 | iot->in_flight -= len; |
101 | if (!iot->in_flight) | |
102 | iot->idle_time = jiffies; | |
103 | } | |
104 | ||
105 | static void iot_io_end(struct io_tracker *iot, sector_t len) | |
106 | { | |
107 | unsigned long flags; | |
108 | ||
109 | spin_lock_irqsave(&iot->lock, flags); | |
110 | __iot_io_end(iot, len); | |
111 | spin_unlock_irqrestore(&iot->lock, flags); | |
112 | } | |
113 | ||
114 | /*----------------------------------------------------------------*/ | |
115 | ||
c6b4fcba | 116 | /* |
b29d4986 JT |
117 | * Represents a chunk of future work. 'input' allows continuations to pass |
118 | * values between themselves, typically error values. | |
c6b4fcba | 119 | */ |
b29d4986 JT |
120 | struct continuation { |
121 | struct work_struct ws; | |
4e4cbee9 | 122 | blk_status_t input; |
b29d4986 JT |
123 | }; |
124 | ||
125 | static inline void init_continuation(struct continuation *k, | |
126 | void (*fn)(struct work_struct *)) | |
127 | { | |
128 | INIT_WORK(&k->ws, fn); | |
129 | k->input = 0; | |
130 | } | |
131 | ||
132 | static inline void queue_continuation(struct workqueue_struct *wq, | |
133 | struct continuation *k) | |
134 | { | |
135 | queue_work(wq, &k->ws); | |
136 | } | |
c6b4fcba JT |
137 | |
138 | /*----------------------------------------------------------------*/ | |
139 | ||
b29d4986 JT |
140 | /* |
141 | * The batcher collects together pieces of work that need a particular | |
142 | * operation to occur before they can proceed (typically a commit). | |
143 | */ | |
144 | struct batcher { | |
145 | /* | |
146 | * The operation that everyone is waiting for. | |
147 | */ | |
4e4cbee9 | 148 | blk_status_t (*commit_op)(void *context); |
b29d4986 JT |
149 | void *commit_context; |
150 | ||
151 | /* | |
152 | * This is how bios should be issued once the commit op is complete | |
153 | * (accounted_request). | |
154 | */ | |
155 | void (*issue_op)(struct bio *bio, void *context); | |
156 | void *issue_context; | |
157 | ||
158 | /* | |
159 | * Queued work gets put on here after commit. | |
160 | */ | |
161 | struct workqueue_struct *wq; | |
162 | ||
163 | spinlock_t lock; | |
164 | struct list_head work_items; | |
165 | struct bio_list bios; | |
166 | struct work_struct commit_work; | |
167 | ||
168 | bool commit_scheduled; | |
169 | }; | |
170 | ||
171 | static void __commit(struct work_struct *_ws) | |
172 | { | |
173 | struct batcher *b = container_of(_ws, struct batcher, commit_work); | |
4e4cbee9 | 174 | blk_status_t r; |
b29d4986 JT |
175 | unsigned long flags; |
176 | struct list_head work_items; | |
177 | struct work_struct *ws, *tmp; | |
178 | struct continuation *k; | |
179 | struct bio *bio; | |
180 | struct bio_list bios; | |
181 | ||
182 | INIT_LIST_HEAD(&work_items); | |
183 | bio_list_init(&bios); | |
184 | ||
185 | /* | |
186 | * We have to grab these before the commit_op to avoid a race | |
187 | * condition. | |
188 | */ | |
189 | spin_lock_irqsave(&b->lock, flags); | |
190 | list_splice_init(&b->work_items, &work_items); | |
191 | bio_list_merge(&bios, &b->bios); | |
192 | bio_list_init(&b->bios); | |
193 | b->commit_scheduled = false; | |
194 | spin_unlock_irqrestore(&b->lock, flags); | |
195 | ||
196 | r = b->commit_op(b->commit_context); | |
197 | ||
198 | list_for_each_entry_safe(ws, tmp, &work_items, entry) { | |
199 | k = container_of(ws, struct continuation, ws); | |
200 | k->input = r; | |
201 | INIT_LIST_HEAD(&ws->entry); /* to avoid a WARN_ON */ | |
202 | queue_work(b->wq, ws); | |
203 | } | |
204 | ||
205 | while ((bio = bio_list_pop(&bios))) { | |
206 | if (r) { | |
4e4cbee9 | 207 | bio->bi_status = r; |
b29d4986 JT |
208 | bio_endio(bio); |
209 | } else | |
210 | b->issue_op(bio, b->issue_context); | |
211 | } | |
212 | } | |
213 | ||
214 | static void batcher_init(struct batcher *b, | |
4e4cbee9 | 215 | blk_status_t (*commit_op)(void *), |
b29d4986 JT |
216 | void *commit_context, |
217 | void (*issue_op)(struct bio *bio, void *), | |
218 | void *issue_context, | |
219 | struct workqueue_struct *wq) | |
220 | { | |
221 | b->commit_op = commit_op; | |
222 | b->commit_context = commit_context; | |
223 | b->issue_op = issue_op; | |
224 | b->issue_context = issue_context; | |
225 | b->wq = wq; | |
226 | ||
227 | spin_lock_init(&b->lock); | |
228 | INIT_LIST_HEAD(&b->work_items); | |
229 | bio_list_init(&b->bios); | |
230 | INIT_WORK(&b->commit_work, __commit); | |
231 | b->commit_scheduled = false; | |
232 | } | |
233 | ||
234 | static void async_commit(struct batcher *b) | |
235 | { | |
236 | queue_work(b->wq, &b->commit_work); | |
237 | } | |
238 | ||
239 | static void continue_after_commit(struct batcher *b, struct continuation *k) | |
240 | { | |
241 | unsigned long flags; | |
242 | bool commit_scheduled; | |
243 | ||
244 | spin_lock_irqsave(&b->lock, flags); | |
245 | commit_scheduled = b->commit_scheduled; | |
246 | list_add_tail(&k->ws.entry, &b->work_items); | |
247 | spin_unlock_irqrestore(&b->lock, flags); | |
248 | ||
249 | if (commit_scheduled) | |
250 | async_commit(b); | |
251 | } | |
252 | ||
253 | /* | |
254 | * Bios are errored if commit failed. | |
255 | */ | |
256 | static void issue_after_commit(struct batcher *b, struct bio *bio) | |
257 | { | |
258 | unsigned long flags; | |
259 | bool commit_scheduled; | |
260 | ||
261 | spin_lock_irqsave(&b->lock, flags); | |
262 | commit_scheduled = b->commit_scheduled; | |
263 | bio_list_add(&b->bios, bio); | |
264 | spin_unlock_irqrestore(&b->lock, flags); | |
265 | ||
266 | if (commit_scheduled) | |
267 | async_commit(b); | |
268 | } | |
269 | ||
270 | /* | |
271 | * Call this if some urgent work is waiting for the commit to complete. | |
272 | */ | |
273 | static void schedule_commit(struct batcher *b) | |
274 | { | |
275 | bool immediate; | |
276 | unsigned long flags; | |
277 | ||
278 | spin_lock_irqsave(&b->lock, flags); | |
279 | immediate = !list_empty(&b->work_items) || !bio_list_empty(&b->bios); | |
280 | b->commit_scheduled = true; | |
281 | spin_unlock_irqrestore(&b->lock, flags); | |
282 | ||
283 | if (immediate) | |
284 | async_commit(b); | |
285 | } | |
286 | ||
c9d28d5d JT |
287 | /* |
288 | * There are a couple of places where we let a bio run, but want to do some | |
289 | * work before calling its endio function. We do this by temporarily | |
290 | * changing the endio fn. | |
291 | */ | |
292 | struct dm_hook_info { | |
293 | bio_end_io_t *bi_end_io; | |
c9d28d5d JT |
294 | }; |
295 | ||
296 | static void dm_hook_bio(struct dm_hook_info *h, struct bio *bio, | |
297 | bio_end_io_t *bi_end_io, void *bi_private) | |
298 | { | |
299 | h->bi_end_io = bio->bi_end_io; | |
c9d28d5d JT |
300 | |
301 | bio->bi_end_io = bi_end_io; | |
302 | bio->bi_private = bi_private; | |
303 | } | |
304 | ||
305 | static void dm_unhook_bio(struct dm_hook_info *h, struct bio *bio) | |
306 | { | |
307 | bio->bi_end_io = h->bi_end_io; | |
c9d28d5d JT |
308 | } |
309 | ||
310 | /*----------------------------------------------------------------*/ | |
311 | ||
c6b4fcba JT |
312 | #define MIGRATION_POOL_SIZE 128 |
313 | #define COMMIT_PERIOD HZ | |
314 | #define MIGRATION_COUNT_WINDOW 10 | |
315 | ||
316 | /* | |
05473044 MS |
317 | * The block size of the device holding cache data must be |
318 | * between 32KB and 1GB. | |
c6b4fcba JT |
319 | */ |
320 | #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (32 * 1024 >> SECTOR_SHIFT) | |
05473044 | 321 | #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT) |
c6b4fcba | 322 | |
2ee57d58 | 323 | enum cache_metadata_mode { |
c6b4fcba JT |
324 | CM_WRITE, /* metadata may be changed */ |
325 | CM_READ_ONLY, /* metadata may not be changed */ | |
028ae9f7 | 326 | CM_FAIL |
c6b4fcba JT |
327 | }; |
328 | ||
2ee57d58 JT |
329 | enum cache_io_mode { |
330 | /* | |
331 | * Data is written to cached blocks only. These blocks are marked | |
332 | * dirty. If you lose the cache device you will lose data. | |
333 | * Potential performance increase for both reads and writes. | |
334 | */ | |
335 | CM_IO_WRITEBACK, | |
336 | ||
337 | /* | |
338 | * Data is written to both cache and origin. Blocks are never | |
339 | * dirty. Potential performance benfit for reads only. | |
340 | */ | |
341 | CM_IO_WRITETHROUGH, | |
342 | ||
343 | /* | |
344 | * A degraded mode useful for various cache coherency situations | |
345 | * (eg, rolling back snapshots). Reads and writes always go to the | |
346 | * origin. If a write goes to a cached oblock, then the cache | |
347 | * block is invalidated. | |
348 | */ | |
349 | CM_IO_PASSTHROUGH | |
350 | }; | |
351 | ||
c6b4fcba | 352 | struct cache_features { |
2ee57d58 JT |
353 | enum cache_metadata_mode mode; |
354 | enum cache_io_mode io_mode; | |
629d0a8a | 355 | unsigned metadata_version; |
c6b4fcba JT |
356 | }; |
357 | ||
358 | struct cache_stats { | |
359 | atomic_t read_hit; | |
360 | atomic_t read_miss; | |
361 | atomic_t write_hit; | |
362 | atomic_t write_miss; | |
363 | atomic_t demotion; | |
364 | atomic_t promotion; | |
b29d4986 | 365 | atomic_t writeback; |
c6b4fcba JT |
366 | atomic_t copies_avoided; |
367 | atomic_t cache_cell_clash; | |
368 | atomic_t commit_count; | |
369 | atomic_t discard_count; | |
370 | }; | |
371 | ||
372 | struct cache { | |
373 | struct dm_target *ti; | |
374 | struct dm_target_callbacks callbacks; | |
375 | ||
c9ec5d7c MS |
376 | struct dm_cache_metadata *cmd; |
377 | ||
c6b4fcba JT |
378 | /* |
379 | * Metadata is written to this device. | |
380 | */ | |
381 | struct dm_dev *metadata_dev; | |
382 | ||
383 | /* | |
384 | * The slower of the two data devices. Typically a spindle. | |
385 | */ | |
386 | struct dm_dev *origin_dev; | |
387 | ||
388 | /* | |
389 | * The faster of the two data devices. Typically an SSD. | |
390 | */ | |
391 | struct dm_dev *cache_dev; | |
392 | ||
c6b4fcba JT |
393 | /* |
394 | * Size of the origin device in _complete_ blocks and native sectors. | |
395 | */ | |
396 | dm_oblock_t origin_blocks; | |
397 | sector_t origin_sectors; | |
398 | ||
399 | /* | |
400 | * Size of the cache device in blocks. | |
401 | */ | |
402 | dm_cblock_t cache_size; | |
403 | ||
404 | /* | |
405 | * Fields for converting from sectors to blocks. | |
406 | */ | |
ca763d0a | 407 | sector_t sectors_per_block; |
c6b4fcba JT |
408 | int sectors_per_block_shift; |
409 | ||
c6b4fcba | 410 | spinlock_t lock; |
651f5fa2 | 411 | struct list_head deferred_cells; |
c6b4fcba | 412 | struct bio_list deferred_bios; |
e2e74d61 | 413 | struct bio_list deferred_writethrough_bios; |
c6b4fcba | 414 | sector_t migration_threshold; |
c6b4fcba | 415 | wait_queue_head_t migration_wait; |
a59db676 JT |
416 | atomic_t nr_allocated_migrations; |
417 | ||
418 | /* | |
419 | * The number of in flight migrations that are performing | |
420 | * background io. eg, promotion, writeback. | |
421 | */ | |
422 | atomic_t nr_io_migrations; | |
c6b4fcba | 423 | |
b29d4986 | 424 | struct rw_semaphore quiesce_lock; |
66cb1910 | 425 | |
c6b4fcba JT |
426 | /* |
427 | * cache_size entries, dirty if set | |
428 | */ | |
44fa816b | 429 | atomic_t nr_dirty; |
c6b4fcba JT |
430 | unsigned long *dirty_bitset; |
431 | ||
432 | /* | |
433 | * origin_blocks entries, discarded if set. | |
434 | */ | |
1bad9bc4 | 435 | dm_dblock_t discard_nr_blocks; |
c6b4fcba | 436 | unsigned long *discard_bitset; |
08b18451 | 437 | uint32_t discard_block_size; /* a power of 2 times sectors per block */ |
c9ec5d7c MS |
438 | |
439 | /* | |
440 | * Rather than reconstructing the table line for the status we just | |
441 | * save it and regurgitate. | |
442 | */ | |
443 | unsigned nr_ctr_args; | |
444 | const char **ctr_args; | |
c6b4fcba JT |
445 | |
446 | struct dm_kcopyd_client *copier; | |
447 | struct workqueue_struct *wq; | |
b29d4986 JT |
448 | struct work_struct deferred_bio_worker; |
449 | struct work_struct deferred_writethrough_worker; | |
450 | struct work_struct migration_worker; | |
c6b4fcba | 451 | struct delayed_work waker; |
b29d4986 | 452 | struct dm_bio_prison_v2 *prison; |
c6b4fcba JT |
453 | |
454 | mempool_t *migration_pool; | |
c6b4fcba JT |
455 | |
456 | struct dm_cache_policy *policy; | |
457 | unsigned policy_nr_args; | |
458 | ||
459 | bool need_tick_bio:1; | |
460 | bool sized:1; | |
65790ff9 | 461 | bool invalidate:1; |
c6b4fcba JT |
462 | bool commit_requested:1; |
463 | bool loaded_mappings:1; | |
464 | bool loaded_discards:1; | |
465 | ||
c6b4fcba | 466 | /* |
c9ec5d7c | 467 | * Cache features such as write-through. |
c6b4fcba | 468 | */ |
c9ec5d7c MS |
469 | struct cache_features features; |
470 | ||
471 | struct cache_stats stats; | |
65790ff9 JT |
472 | |
473 | /* | |
474 | * Invalidation fields. | |
475 | */ | |
476 | spinlock_t invalidation_lock; | |
477 | struct list_head invalidation_requests; | |
066dbaa3 | 478 | |
701e03e4 | 479 | struct io_tracker tracker; |
b29d4986 JT |
480 | |
481 | struct work_struct commit_ws; | |
482 | struct batcher committer; | |
483 | ||
484 | struct rw_semaphore background_work_lock; | |
c6b4fcba JT |
485 | }; |
486 | ||
487 | struct per_bio_data { | |
488 | bool tick:1; | |
489 | unsigned req_nr:2; | |
b29d4986 | 490 | struct dm_bio_prison_cell_v2 *cell; |
c6eda5e8 | 491 | struct dm_hook_info hook_info; |
066dbaa3 | 492 | sector_t len; |
e2e74d61 | 493 | |
19b0092e MS |
494 | /* |
495 | * writethrough fields. These MUST remain at the end of this | |
496 | * structure and the 'cache' member must be the first as it | |
aeed1420 | 497 | * is used to determine the offset of the writethrough fields. |
19b0092e | 498 | */ |
e2e74d61 JT |
499 | struct cache *cache; |
500 | dm_cblock_t cblock; | |
b844fe69 | 501 | struct dm_bio_details bio_details; |
c6b4fcba JT |
502 | }; |
503 | ||
504 | struct dm_cache_migration { | |
b29d4986 | 505 | struct continuation k; |
c6b4fcba JT |
506 | struct cache *cache; |
507 | ||
b29d4986 JT |
508 | struct policy_work *op; |
509 | struct bio *overwrite_bio; | |
510 | struct dm_bio_prison_cell_v2 *cell; | |
c6b4fcba | 511 | |
b29d4986 JT |
512 | dm_cblock_t invalidate_cblock; |
513 | dm_oblock_t invalidate_oblock; | |
c6b4fcba JT |
514 | }; |
515 | ||
b29d4986 JT |
516 | /*----------------------------------------------------------------*/ |
517 | ||
518 | static bool writethrough_mode(struct cache_features *f) | |
519 | { | |
520 | return f->io_mode == CM_IO_WRITETHROUGH; | |
521 | } | |
522 | ||
523 | static bool writeback_mode(struct cache_features *f) | |
524 | { | |
525 | return f->io_mode == CM_IO_WRITEBACK; | |
526 | } | |
527 | ||
528 | static inline bool passthrough_mode(struct cache_features *f) | |
529 | { | |
530 | return unlikely(f->io_mode == CM_IO_PASSTHROUGH); | |
531 | } | |
532 | ||
533 | /*----------------------------------------------------------------*/ | |
534 | ||
535 | static void wake_deferred_bio_worker(struct cache *cache) | |
536 | { | |
537 | queue_work(cache->wq, &cache->deferred_bio_worker); | |
538 | } | |
c6b4fcba | 539 | |
b29d4986 JT |
540 | static void wake_deferred_writethrough_worker(struct cache *cache) |
541 | { | |
542 | queue_work(cache->wq, &cache->deferred_writethrough_worker); | |
543 | } | |
028ae9f7 | 544 | |
b29d4986 | 545 | static void wake_migration_worker(struct cache *cache) |
c6b4fcba | 546 | { |
b29d4986 JT |
547 | if (passthrough_mode(&cache->features)) |
548 | return; | |
549 | ||
550 | queue_work(cache->wq, &cache->migration_worker); | |
c6b4fcba JT |
551 | } |
552 | ||
553 | /*----------------------------------------------------------------*/ | |
554 | ||
b29d4986 | 555 | static struct dm_bio_prison_cell_v2 *alloc_prison_cell(struct cache *cache) |
c6b4fcba | 556 | { |
b29d4986 | 557 | return dm_bio_prison_alloc_cell_v2(cache->prison, GFP_NOWAIT); |
c6b4fcba JT |
558 | } |
559 | ||
b29d4986 | 560 | static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell_v2 *cell) |
c6b4fcba | 561 | { |
b29d4986 | 562 | dm_bio_prison_free_cell_v2(cache->prison, cell); |
c6b4fcba JT |
563 | } |
564 | ||
a59db676 JT |
565 | static struct dm_cache_migration *alloc_migration(struct cache *cache) |
566 | { | |
567 | struct dm_cache_migration *mg; | |
568 | ||
569 | mg = mempool_alloc(cache->migration_pool, GFP_NOWAIT); | |
570 | if (mg) { | |
571 | mg->cache = cache; | |
572 | atomic_inc(&mg->cache->nr_allocated_migrations); | |
573 | } | |
574 | ||
575 | return mg; | |
576 | } | |
577 | ||
578 | static void free_migration(struct dm_cache_migration *mg) | |
579 | { | |
88bf5184 | 580 | struct cache *cache = mg->cache; |
a59db676 | 581 | |
88bf5184 JT |
582 | if (atomic_dec_and_test(&cache->nr_allocated_migrations)) |
583 | wake_up(&cache->migration_wait); | |
584 | ||
585 | mempool_free(mg, cache->migration_pool); | |
a59db676 JT |
586 | } |
587 | ||
b29d4986 | 588 | /*----------------------------------------------------------------*/ |
c6b4fcba | 589 | |
b29d4986 | 590 | static inline dm_oblock_t oblock_succ(dm_oblock_t b) |
c6b4fcba | 591 | { |
b29d4986 | 592 | return to_oblock(from_oblock(b) + 1ull); |
c6b4fcba JT |
593 | } |
594 | ||
b29d4986 | 595 | static void build_key(dm_oblock_t begin, dm_oblock_t end, struct dm_cell_key_v2 *key) |
c6b4fcba | 596 | { |
b29d4986 JT |
597 | key->virtual = 0; |
598 | key->dev = 0; | |
599 | key->block_begin = from_oblock(begin); | |
600 | key->block_end = from_oblock(end); | |
c6b4fcba JT |
601 | } |
602 | ||
603 | /* | |
b29d4986 JT |
604 | * We have two lock levels. Level 0, which is used to prevent WRITEs, and |
605 | * level 1 which prevents *both* READs and WRITEs. | |
c6b4fcba | 606 | */ |
b29d4986 JT |
607 | #define WRITE_LOCK_LEVEL 0 |
608 | #define READ_WRITE_LOCK_LEVEL 1 | |
609 | ||
610 | static unsigned lock_level(struct bio *bio) | |
c6b4fcba | 611 | { |
b29d4986 JT |
612 | return bio_data_dir(bio) == WRITE ? |
613 | WRITE_LOCK_LEVEL : | |
614 | READ_WRITE_LOCK_LEVEL; | |
615 | } | |
c6b4fcba | 616 | |
b29d4986 JT |
617 | /*---------------------------------------------------------------- |
618 | * Per bio data | |
619 | *--------------------------------------------------------------*/ | |
c6b4fcba | 620 | |
b29d4986 JT |
621 | /* |
622 | * If using writeback, leave out struct per_bio_data's writethrough fields. | |
623 | */ | |
624 | #define PB_DATA_SIZE_WB (offsetof(struct per_bio_data, cache)) | |
625 | #define PB_DATA_SIZE_WT (sizeof(struct per_bio_data)) | |
c6b4fcba | 626 | |
b29d4986 JT |
627 | static size_t get_per_bio_data_size(struct cache *cache) |
628 | { | |
629 | return writethrough_mode(&cache->features) ? PB_DATA_SIZE_WT : PB_DATA_SIZE_WB; | |
c6b4fcba JT |
630 | } |
631 | ||
b29d4986 | 632 | static struct per_bio_data *get_per_bio_data(struct bio *bio, size_t data_size) |
c6b4fcba | 633 | { |
b29d4986 JT |
634 | struct per_bio_data *pb = dm_per_bio_data(bio, data_size); |
635 | BUG_ON(!pb); | |
636 | return pb; | |
637 | } | |
c6b4fcba | 638 | |
b29d4986 JT |
639 | static struct per_bio_data *init_per_bio_data(struct bio *bio, size_t data_size) |
640 | { | |
641 | struct per_bio_data *pb = get_per_bio_data(bio, data_size); | |
c6b4fcba | 642 | |
b29d4986 JT |
643 | pb->tick = false; |
644 | pb->req_nr = dm_bio_get_target_bio_nr(bio); | |
645 | pb->cell = NULL; | |
646 | pb->len = 0; | |
647 | ||
648 | return pb; | |
c6b4fcba JT |
649 | } |
650 | ||
651 | /*----------------------------------------------------------------*/ | |
652 | ||
b29d4986 | 653 | static void defer_bio(struct cache *cache, struct bio *bio) |
c6b4fcba | 654 | { |
b29d4986 | 655 | unsigned long flags; |
c6b4fcba | 656 | |
b29d4986 JT |
657 | spin_lock_irqsave(&cache->lock, flags); |
658 | bio_list_add(&cache->deferred_bios, bio); | |
659 | spin_unlock_irqrestore(&cache->lock, flags); | |
660 | ||
661 | wake_deferred_bio_worker(cache); | |
662 | } | |
c6b4fcba | 663 | |
b29d4986 | 664 | static void defer_bios(struct cache *cache, struct bio_list *bios) |
c6b4fcba | 665 | { |
b29d4986 | 666 | unsigned long flags; |
c6b4fcba | 667 | |
b29d4986 JT |
668 | spin_lock_irqsave(&cache->lock, flags); |
669 | bio_list_merge(&cache->deferred_bios, bios); | |
670 | bio_list_init(bios); | |
671 | spin_unlock_irqrestore(&cache->lock, flags); | |
c6b4fcba | 672 | |
b29d4986 | 673 | wake_deferred_bio_worker(cache); |
c6b4fcba JT |
674 | } |
675 | ||
b29d4986 JT |
676 | /*----------------------------------------------------------------*/ |
677 | ||
678 | static bool bio_detain_shared(struct cache *cache, dm_oblock_t oblock, struct bio *bio) | |
7ae34e77 | 679 | { |
b29d4986 JT |
680 | bool r; |
681 | size_t pb_size; | |
682 | struct per_bio_data *pb; | |
683 | struct dm_cell_key_v2 key; | |
7ae34e77 | 684 | dm_oblock_t end = to_oblock(from_oblock(oblock) + 1ULL); |
b29d4986 | 685 | struct dm_bio_prison_cell_v2 *cell_prealloc, *cell; |
7ae34e77 | 686 | |
b29d4986 JT |
687 | cell_prealloc = alloc_prison_cell(cache); /* FIXME: allow wait if calling from worker */ |
688 | if (!cell_prealloc) { | |
689 | defer_bio(cache, bio); | |
690 | return false; | |
691 | } | |
692 | ||
693 | build_key(oblock, end, &key); | |
694 | r = dm_cell_get_v2(cache->prison, &key, lock_level(bio), bio, cell_prealloc, &cell); | |
695 | if (!r) { | |
696 | /* | |
697 | * Failed to get the lock. | |
698 | */ | |
699 | free_prison_cell(cache, cell_prealloc); | |
700 | return r; | |
701 | } | |
c6b4fcba | 702 | |
b29d4986 JT |
703 | if (cell != cell_prealloc) |
704 | free_prison_cell(cache, cell_prealloc); | |
c6b4fcba | 705 | |
b29d4986 JT |
706 | pb_size = get_per_bio_data_size(cache); |
707 | pb = get_per_bio_data(bio, pb_size); | |
708 | pb->cell = cell; | |
c6b4fcba JT |
709 | |
710 | return r; | |
711 | } | |
712 | ||
aeed1420 | 713 | /*----------------------------------------------------------------*/ |
c6b4fcba JT |
714 | |
715 | static bool is_dirty(struct cache *cache, dm_cblock_t b) | |
716 | { | |
717 | return test_bit(from_cblock(b), cache->dirty_bitset); | |
718 | } | |
719 | ||
b29d4986 | 720 | static void set_dirty(struct cache *cache, dm_cblock_t cblock) |
c6b4fcba JT |
721 | { |
722 | if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
44fa816b | 723 | atomic_inc(&cache->nr_dirty); |
b29d4986 | 724 | policy_set_dirty(cache->policy, cblock); |
c6b4fcba JT |
725 | } |
726 | } | |
727 | ||
b29d4986 JT |
728 | /* |
729 | * These two are called when setting after migrations to force the policy | |
730 | * and dirty bitset to be in sync. | |
731 | */ | |
732 | static void force_set_dirty(struct cache *cache, dm_cblock_t cblock) | |
733 | { | |
734 | if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) | |
735 | atomic_inc(&cache->nr_dirty); | |
736 | policy_set_dirty(cache->policy, cblock); | |
737 | } | |
738 | ||
739 | static void force_clear_dirty(struct cache *cache, dm_cblock_t cblock) | |
c6b4fcba JT |
740 | { |
741 | if (test_and_clear_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
44fa816b | 742 | if (atomic_dec_return(&cache->nr_dirty) == 0) |
c6b4fcba JT |
743 | dm_table_event(cache->ti->table); |
744 | } | |
b29d4986 JT |
745 | |
746 | policy_clear_dirty(cache->policy, cblock); | |
c6b4fcba JT |
747 | } |
748 | ||
749 | /*----------------------------------------------------------------*/ | |
aeed1420 | 750 | |
c6b4fcba JT |
751 | static bool block_size_is_power_of_two(struct cache *cache) |
752 | { | |
753 | return cache->sectors_per_block_shift >= 0; | |
754 | } | |
755 | ||
43aeaa29 MP |
756 | /* gcc on ARM generates spurious references to __udivdi3 and __umoddi3 */ |
757 | #if defined(CONFIG_ARM) && __GNUC__ == 4 && __GNUC_MINOR__ <= 6 | |
758 | __always_inline | |
759 | #endif | |
414dd67d JT |
760 | static dm_block_t block_div(dm_block_t b, uint32_t n) |
761 | { | |
762 | do_div(b, n); | |
763 | ||
764 | return b; | |
765 | } | |
766 | ||
7ae34e77 | 767 | static dm_block_t oblocks_per_dblock(struct cache *cache) |
1bad9bc4 | 768 | { |
7ae34e77 | 769 | dm_block_t oblocks = cache->discard_block_size; |
1bad9bc4 | 770 | |
7ae34e77 JT |
771 | if (block_size_is_power_of_two(cache)) |
772 | oblocks >>= cache->sectors_per_block_shift; | |
1bad9bc4 | 773 | else |
7ae34e77 | 774 | oblocks = block_div(oblocks, cache->sectors_per_block); |
1bad9bc4 | 775 | |
7ae34e77 JT |
776 | return oblocks; |
777 | } | |
778 | ||
779 | static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock) | |
780 | { | |
781 | return to_dblock(block_div(from_oblock(oblock), | |
782 | oblocks_per_dblock(cache))); | |
783 | } | |
1bad9bc4 | 784 | |
1bad9bc4 | 785 | static void set_discard(struct cache *cache, dm_dblock_t b) |
c6b4fcba JT |
786 | { |
787 | unsigned long flags; | |
788 | ||
7ae34e77 | 789 | BUG_ON(from_dblock(b) >= from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
790 | atomic_inc(&cache->stats.discard_count); |
791 | ||
792 | spin_lock_irqsave(&cache->lock, flags); | |
1bad9bc4 | 793 | set_bit(from_dblock(b), cache->discard_bitset); |
c6b4fcba JT |
794 | spin_unlock_irqrestore(&cache->lock, flags); |
795 | } | |
796 | ||
1bad9bc4 | 797 | static void clear_discard(struct cache *cache, dm_dblock_t b) |
c6b4fcba JT |
798 | { |
799 | unsigned long flags; | |
800 | ||
801 | spin_lock_irqsave(&cache->lock, flags); | |
1bad9bc4 | 802 | clear_bit(from_dblock(b), cache->discard_bitset); |
c6b4fcba JT |
803 | spin_unlock_irqrestore(&cache->lock, flags); |
804 | } | |
805 | ||
1bad9bc4 | 806 | static bool is_discarded(struct cache *cache, dm_dblock_t b) |
c6b4fcba JT |
807 | { |
808 | int r; | |
809 | unsigned long flags; | |
810 | ||
811 | spin_lock_irqsave(&cache->lock, flags); | |
1bad9bc4 | 812 | r = test_bit(from_dblock(b), cache->discard_bitset); |
c6b4fcba JT |
813 | spin_unlock_irqrestore(&cache->lock, flags); |
814 | ||
815 | return r; | |
816 | } | |
817 | ||
818 | static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b) | |
819 | { | |
820 | int r; | |
821 | unsigned long flags; | |
822 | ||
823 | spin_lock_irqsave(&cache->lock, flags); | |
1bad9bc4 JT |
824 | r = test_bit(from_dblock(oblock_to_dblock(cache, b)), |
825 | cache->discard_bitset); | |
c6b4fcba JT |
826 | spin_unlock_irqrestore(&cache->lock, flags); |
827 | ||
828 | return r; | |
829 | } | |
830 | ||
b29d4986 JT |
831 | /*---------------------------------------------------------------- |
832 | * Remapping | |
833 | *--------------------------------------------------------------*/ | |
834 | static void remap_to_origin(struct cache *cache, struct bio *bio) | |
c6b4fcba | 835 | { |
74d46992 | 836 | bio_set_dev(bio, cache->origin_dev->bdev); |
c6b4fcba JT |
837 | } |
838 | ||
839 | static void remap_to_cache(struct cache *cache, struct bio *bio, | |
840 | dm_cblock_t cblock) | |
841 | { | |
4f024f37 | 842 | sector_t bi_sector = bio->bi_iter.bi_sector; |
e0d849fa | 843 | sector_t block = from_cblock(cblock); |
c6b4fcba | 844 | |
74d46992 | 845 | bio_set_dev(bio, cache->cache_dev->bdev); |
c6b4fcba | 846 | if (!block_size_is_power_of_two(cache)) |
4f024f37 | 847 | bio->bi_iter.bi_sector = |
e0d849fa | 848 | (block * cache->sectors_per_block) + |
4f024f37 | 849 | sector_div(bi_sector, cache->sectors_per_block); |
c6b4fcba | 850 | else |
4f024f37 | 851 | bio->bi_iter.bi_sector = |
e0d849fa | 852 | (block << cache->sectors_per_block_shift) | |
4f024f37 | 853 | (bi_sector & (cache->sectors_per_block - 1)); |
c6b4fcba JT |
854 | } |
855 | ||
856 | static void check_if_tick_bio_needed(struct cache *cache, struct bio *bio) | |
857 | { | |
858 | unsigned long flags; | |
19b0092e MS |
859 | size_t pb_data_size = get_per_bio_data_size(cache); |
860 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
c6b4fcba JT |
861 | |
862 | spin_lock_irqsave(&cache->lock, flags); | |
f73f44eb | 863 | if (cache->need_tick_bio && !op_is_flush(bio->bi_opf) && |
e6047149 | 864 | bio_op(bio) != REQ_OP_DISCARD) { |
c6b4fcba JT |
865 | pb->tick = true; |
866 | cache->need_tick_bio = false; | |
867 | } | |
868 | spin_unlock_irqrestore(&cache->lock, flags); | |
869 | } | |
870 | ||
871 | static void remap_to_origin_clear_discard(struct cache *cache, struct bio *bio, | |
b29d4986 | 872 | dm_oblock_t oblock) |
c6b4fcba | 873 | { |
b29d4986 | 874 | // FIXME: this is called way too much. |
c6b4fcba JT |
875 | check_if_tick_bio_needed(cache, bio); |
876 | remap_to_origin(cache, bio); | |
877 | if (bio_data_dir(bio) == WRITE) | |
1bad9bc4 | 878 | clear_discard(cache, oblock_to_dblock(cache, oblock)); |
c6b4fcba JT |
879 | } |
880 | ||
881 | static void remap_to_cache_dirty(struct cache *cache, struct bio *bio, | |
882 | dm_oblock_t oblock, dm_cblock_t cblock) | |
883 | { | |
f8e5f01a | 884 | check_if_tick_bio_needed(cache, bio); |
c6b4fcba JT |
885 | remap_to_cache(cache, bio, cblock); |
886 | if (bio_data_dir(bio) == WRITE) { | |
b29d4986 | 887 | set_dirty(cache, cblock); |
1bad9bc4 | 888 | clear_discard(cache, oblock_to_dblock(cache, oblock)); |
c6b4fcba JT |
889 | } |
890 | } | |
891 | ||
892 | static dm_oblock_t get_bio_block(struct cache *cache, struct bio *bio) | |
893 | { | |
4f024f37 | 894 | sector_t block_nr = bio->bi_iter.bi_sector; |
c6b4fcba JT |
895 | |
896 | if (!block_size_is_power_of_two(cache)) | |
897 | (void) sector_div(block_nr, cache->sectors_per_block); | |
898 | else | |
899 | block_nr >>= cache->sectors_per_block_shift; | |
900 | ||
901 | return to_oblock(block_nr); | |
902 | } | |
903 | ||
066dbaa3 JT |
904 | static bool accountable_bio(struct cache *cache, struct bio *bio) |
905 | { | |
701e03e4 | 906 | return bio_op(bio) != REQ_OP_DISCARD; |
066dbaa3 JT |
907 | } |
908 | ||
909 | static void accounted_begin(struct cache *cache, struct bio *bio) | |
910 | { | |
911 | size_t pb_data_size = get_per_bio_data_size(cache); | |
912 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
913 | ||
914 | if (accountable_bio(cache, bio)) { | |
915 | pb->len = bio_sectors(bio); | |
701e03e4 | 916 | iot_io_begin(&cache->tracker, pb->len); |
066dbaa3 JT |
917 | } |
918 | } | |
919 | ||
920 | static void accounted_complete(struct cache *cache, struct bio *bio) | |
921 | { | |
922 | size_t pb_data_size = get_per_bio_data_size(cache); | |
923 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
924 | ||
701e03e4 | 925 | iot_io_end(&cache->tracker, pb->len); |
066dbaa3 JT |
926 | } |
927 | ||
928 | static void accounted_request(struct cache *cache, struct bio *bio) | |
929 | { | |
930 | accounted_begin(cache, bio); | |
931 | generic_make_request(bio); | |
932 | } | |
933 | ||
b29d4986 | 934 | static void issue_op(struct bio *bio, void *context) |
8c081b52 | 935 | { |
b29d4986 JT |
936 | struct cache *cache = context; |
937 | accounted_request(cache, bio); | |
8c081b52 JT |
938 | } |
939 | ||
e2e74d61 JT |
940 | static void defer_writethrough_bio(struct cache *cache, struct bio *bio) |
941 | { | |
942 | unsigned long flags; | |
943 | ||
944 | spin_lock_irqsave(&cache->lock, flags); | |
945 | bio_list_add(&cache->deferred_writethrough_bios, bio); | |
946 | spin_unlock_irqrestore(&cache->lock, flags); | |
947 | ||
b29d4986 | 948 | wake_deferred_writethrough_worker(cache); |
e2e74d61 JT |
949 | } |
950 | ||
4246a0b6 | 951 | static void writethrough_endio(struct bio *bio) |
e2e74d61 | 952 | { |
19b0092e | 953 | struct per_bio_data *pb = get_per_bio_data(bio, PB_DATA_SIZE_WT); |
c9d28d5d JT |
954 | |
955 | dm_unhook_bio(&pb->hook_info, bio); | |
e2e74d61 | 956 | |
4e4cbee9 | 957 | if (bio->bi_status) { |
4246a0b6 | 958 | bio_endio(bio); |
e2e74d61 JT |
959 | return; |
960 | } | |
961 | ||
b844fe69 | 962 | dm_bio_restore(&pb->bio_details, bio); |
e2e74d61 JT |
963 | remap_to_cache(pb->cache, bio, pb->cblock); |
964 | ||
965 | /* | |
966 | * We can't issue this bio directly, since we're in interrupt | |
aeed1420 | 967 | * context. So it gets put on a bio list for processing by the |
e2e74d61 JT |
968 | * worker thread. |
969 | */ | |
970 | defer_writethrough_bio(pb->cache, bio); | |
971 | } | |
972 | ||
973 | /* | |
b29d4986 | 974 | * FIXME: send in parallel, huge latency as is. |
e2e74d61 JT |
975 | * When running in writethrough mode we need to send writes to clean blocks |
976 | * to both the cache and origin devices. In future we'd like to clone the | |
977 | * bio and send them in parallel, but for now we're doing them in | |
978 | * series as this is easier. | |
979 | */ | |
980 | static void remap_to_origin_then_cache(struct cache *cache, struct bio *bio, | |
981 | dm_oblock_t oblock, dm_cblock_t cblock) | |
982 | { | |
19b0092e | 983 | struct per_bio_data *pb = get_per_bio_data(bio, PB_DATA_SIZE_WT); |
e2e74d61 JT |
984 | |
985 | pb->cache = cache; | |
986 | pb->cblock = cblock; | |
c9d28d5d | 987 | dm_hook_bio(&pb->hook_info, bio, writethrough_endio, NULL); |
b844fe69 | 988 | dm_bio_record(&pb->bio_details, bio); |
e2e74d61 JT |
989 | |
990 | remap_to_origin_clear_discard(pb->cache, bio, oblock); | |
991 | } | |
992 | ||
028ae9f7 JT |
993 | /*---------------------------------------------------------------- |
994 | * Failure modes | |
995 | *--------------------------------------------------------------*/ | |
996 | static enum cache_metadata_mode get_cache_mode(struct cache *cache) | |
997 | { | |
998 | return cache->features.mode; | |
999 | } | |
1000 | ||
b61d9509 MS |
1001 | static const char *cache_device_name(struct cache *cache) |
1002 | { | |
1003 | return dm_device_name(dm_table_get_md(cache->ti->table)); | |
1004 | } | |
1005 | ||
028ae9f7 JT |
1006 | static void notify_mode_switch(struct cache *cache, enum cache_metadata_mode mode) |
1007 | { | |
1008 | const char *descs[] = { | |
1009 | "write", | |
1010 | "read-only", | |
1011 | "fail" | |
1012 | }; | |
1013 | ||
1014 | dm_table_event(cache->ti->table); | |
b61d9509 MS |
1015 | DMINFO("%s: switching cache to %s mode", |
1016 | cache_device_name(cache), descs[(int)mode]); | |
028ae9f7 JT |
1017 | } |
1018 | ||
1019 | static void set_cache_mode(struct cache *cache, enum cache_metadata_mode new_mode) | |
1020 | { | |
d14fcf3d | 1021 | bool needs_check; |
028ae9f7 JT |
1022 | enum cache_metadata_mode old_mode = get_cache_mode(cache); |
1023 | ||
d14fcf3d | 1024 | if (dm_cache_metadata_needs_check(cache->cmd, &needs_check)) { |
23cab26d MS |
1025 | DMERR("%s: unable to read needs_check flag, setting failure mode.", |
1026 | cache_device_name(cache)); | |
d14fcf3d JT |
1027 | new_mode = CM_FAIL; |
1028 | } | |
1029 | ||
028ae9f7 | 1030 | if (new_mode == CM_WRITE && needs_check) { |
b61d9509 MS |
1031 | DMERR("%s: unable to switch cache to write mode until repaired.", |
1032 | cache_device_name(cache)); | |
028ae9f7 JT |
1033 | if (old_mode != new_mode) |
1034 | new_mode = old_mode; | |
1035 | else | |
1036 | new_mode = CM_READ_ONLY; | |
1037 | } | |
1038 | ||
1039 | /* Never move out of fail mode */ | |
1040 | if (old_mode == CM_FAIL) | |
1041 | new_mode = CM_FAIL; | |
1042 | ||
1043 | switch (new_mode) { | |
1044 | case CM_FAIL: | |
1045 | case CM_READ_ONLY: | |
1046 | dm_cache_metadata_set_read_only(cache->cmd); | |
1047 | break; | |
1048 | ||
1049 | case CM_WRITE: | |
1050 | dm_cache_metadata_set_read_write(cache->cmd); | |
1051 | break; | |
1052 | } | |
1053 | ||
1054 | cache->features.mode = new_mode; | |
1055 | ||
1056 | if (new_mode != old_mode) | |
1057 | notify_mode_switch(cache, new_mode); | |
1058 | } | |
1059 | ||
1060 | static void abort_transaction(struct cache *cache) | |
1061 | { | |
b61d9509 MS |
1062 | const char *dev_name = cache_device_name(cache); |
1063 | ||
028ae9f7 JT |
1064 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
1065 | return; | |
1066 | ||
1067 | if (dm_cache_metadata_set_needs_check(cache->cmd)) { | |
b61d9509 | 1068 | DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name); |
028ae9f7 JT |
1069 | set_cache_mode(cache, CM_FAIL); |
1070 | } | |
1071 | ||
b61d9509 | 1072 | DMERR_LIMIT("%s: aborting current metadata transaction", dev_name); |
028ae9f7 | 1073 | if (dm_cache_metadata_abort(cache->cmd)) { |
b61d9509 | 1074 | DMERR("%s: failed to abort metadata transaction", dev_name); |
028ae9f7 JT |
1075 | set_cache_mode(cache, CM_FAIL); |
1076 | } | |
1077 | } | |
1078 | ||
1079 | static void metadata_operation_failed(struct cache *cache, const char *op, int r) | |
1080 | { | |
b61d9509 MS |
1081 | DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d", |
1082 | cache_device_name(cache), op, r); | |
028ae9f7 JT |
1083 | abort_transaction(cache); |
1084 | set_cache_mode(cache, CM_READ_ONLY); | |
1085 | } | |
1086 | ||
b29d4986 JT |
1087 | /*----------------------------------------------------------------*/ |
1088 | ||
1089 | static void load_stats(struct cache *cache) | |
1090 | { | |
1091 | struct dm_cache_statistics stats; | |
1092 | ||
1093 | dm_cache_metadata_get_stats(cache->cmd, &stats); | |
1094 | atomic_set(&cache->stats.read_hit, stats.read_hits); | |
1095 | atomic_set(&cache->stats.read_miss, stats.read_misses); | |
1096 | atomic_set(&cache->stats.write_hit, stats.write_hits); | |
1097 | atomic_set(&cache->stats.write_miss, stats.write_misses); | |
1098 | } | |
1099 | ||
1100 | static void save_stats(struct cache *cache) | |
1101 | { | |
1102 | struct dm_cache_statistics stats; | |
1103 | ||
1104 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
1105 | return; | |
1106 | ||
1107 | stats.read_hits = atomic_read(&cache->stats.read_hit); | |
1108 | stats.read_misses = atomic_read(&cache->stats.read_miss); | |
1109 | stats.write_hits = atomic_read(&cache->stats.write_hit); | |
1110 | stats.write_misses = atomic_read(&cache->stats.write_miss); | |
1111 | ||
1112 | dm_cache_metadata_set_stats(cache->cmd, &stats); | |
1113 | } | |
1114 | ||
1115 | static void update_stats(struct cache_stats *stats, enum policy_operation op) | |
1116 | { | |
1117 | switch (op) { | |
1118 | case POLICY_PROMOTE: | |
1119 | atomic_inc(&stats->promotion); | |
1120 | break; | |
1121 | ||
1122 | case POLICY_DEMOTE: | |
1123 | atomic_inc(&stats->demotion); | |
1124 | break; | |
1125 | ||
1126 | case POLICY_WRITEBACK: | |
1127 | atomic_inc(&stats->writeback); | |
1128 | break; | |
1129 | } | |
1130 | } | |
1131 | ||
c6b4fcba JT |
1132 | /*---------------------------------------------------------------- |
1133 | * Migration processing | |
1134 | * | |
1135 | * Migration covers moving data from the origin device to the cache, or | |
1136 | * vice versa. | |
1137 | *--------------------------------------------------------------*/ | |
b29d4986 | 1138 | |
a59db676 | 1139 | static void inc_io_migrations(struct cache *cache) |
c6b4fcba | 1140 | { |
a59db676 | 1141 | atomic_inc(&cache->nr_io_migrations); |
c6b4fcba JT |
1142 | } |
1143 | ||
a59db676 | 1144 | static void dec_io_migrations(struct cache *cache) |
c6b4fcba | 1145 | { |
a59db676 | 1146 | atomic_dec(&cache->nr_io_migrations); |
c6b4fcba JT |
1147 | } |
1148 | ||
651f5fa2 JT |
1149 | static bool discard_or_flush(struct bio *bio) |
1150 | { | |
f73f44eb | 1151 | return bio_op(bio) == REQ_OP_DISCARD || op_is_flush(bio->bi_opf); |
651f5fa2 JT |
1152 | } |
1153 | ||
b29d4986 JT |
1154 | static void calc_discard_block_range(struct cache *cache, struct bio *bio, |
1155 | dm_dblock_t *b, dm_dblock_t *e) | |
c6b4fcba | 1156 | { |
b29d4986 JT |
1157 | sector_t sb = bio->bi_iter.bi_sector; |
1158 | sector_t se = bio_end_sector(bio); | |
651f5fa2 | 1159 | |
b29d4986 | 1160 | *b = to_dblock(dm_sector_div_up(sb, cache->discard_block_size)); |
c6b4fcba | 1161 | |
b29d4986 JT |
1162 | if (se - sb < cache->discard_block_size) |
1163 | *e = *b; | |
1164 | else | |
1165 | *e = to_dblock(block_div(se, cache->discard_block_size)); | |
c6b4fcba JT |
1166 | } |
1167 | ||
b29d4986 | 1168 | /*----------------------------------------------------------------*/ |
651f5fa2 | 1169 | |
b29d4986 | 1170 | static void prevent_background_work(struct cache *cache) |
651f5fa2 | 1171 | { |
b29d4986 JT |
1172 | lockdep_off(); |
1173 | down_write(&cache->background_work_lock); | |
1174 | lockdep_on(); | |
651f5fa2 JT |
1175 | } |
1176 | ||
b29d4986 | 1177 | static void allow_background_work(struct cache *cache) |
c6b4fcba | 1178 | { |
b29d4986 JT |
1179 | lockdep_off(); |
1180 | up_write(&cache->background_work_lock); | |
1181 | lockdep_on(); | |
c6b4fcba JT |
1182 | } |
1183 | ||
b29d4986 | 1184 | static bool background_work_begin(struct cache *cache) |
c6b4fcba | 1185 | { |
b29d4986 | 1186 | bool r; |
c6b4fcba | 1187 | |
b29d4986 JT |
1188 | lockdep_off(); |
1189 | r = down_read_trylock(&cache->background_work_lock); | |
1190 | lockdep_on(); | |
c6b4fcba | 1191 | |
b29d4986 | 1192 | return r; |
c6b4fcba JT |
1193 | } |
1194 | ||
b29d4986 | 1195 | static void background_work_end(struct cache *cache) |
c6b4fcba | 1196 | { |
b29d4986 JT |
1197 | lockdep_off(); |
1198 | up_read(&cache->background_work_lock); | |
1199 | lockdep_on(); | |
1200 | } | |
c6b4fcba | 1201 | |
b29d4986 | 1202 | /*----------------------------------------------------------------*/ |
c6b4fcba | 1203 | |
ec544ec9 JT |
1204 | static bool bio_writes_complete_block(struct cache *cache, struct bio *bio) |
1205 | { | |
1206 | return (bio_data_dir(bio) == WRITE) && | |
1207 | (bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT)); | |
1208 | } | |
1209 | ||
1210 | static bool optimisable_bio(struct cache *cache, struct bio *bio, dm_oblock_t block) | |
1211 | { | |
1212 | return writeback_mode(&cache->features) && | |
1213 | (is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio)); | |
1214 | } | |
1215 | ||
b29d4986 JT |
1216 | static void quiesce(struct dm_cache_migration *mg, |
1217 | void (*continuation)(struct work_struct *)) | |
1218 | { | |
1219 | init_continuation(&mg->k, continuation); | |
1220 | dm_cell_quiesce_v2(mg->cache->prison, mg->cell, &mg->k.ws); | |
c6b4fcba JT |
1221 | } |
1222 | ||
b29d4986 | 1223 | static struct dm_cache_migration *ws_to_mg(struct work_struct *ws) |
c6b4fcba | 1224 | { |
b29d4986 JT |
1225 | struct continuation *k = container_of(ws, struct continuation, ws); |
1226 | return container_of(k, struct dm_cache_migration, k); | |
c6b4fcba JT |
1227 | } |
1228 | ||
1229 | static void copy_complete(int read_err, unsigned long write_err, void *context) | |
1230 | { | |
b29d4986 | 1231 | struct dm_cache_migration *mg = container_of(context, struct dm_cache_migration, k); |
c6b4fcba JT |
1232 | |
1233 | if (read_err || write_err) | |
4e4cbee9 | 1234 | mg->k.input = BLK_STS_IOERR; |
c6b4fcba | 1235 | |
b29d4986 | 1236 | queue_continuation(mg->cache->wq, &mg->k); |
c6b4fcba JT |
1237 | } |
1238 | ||
b29d4986 | 1239 | static int copy(struct dm_cache_migration *mg, bool promote) |
c6b4fcba JT |
1240 | { |
1241 | int r; | |
1242 | struct dm_io_region o_region, c_region; | |
1243 | struct cache *cache = mg->cache; | |
1244 | ||
1245 | o_region.bdev = cache->origin_dev->bdev; | |
b29d4986 | 1246 | o_region.sector = from_oblock(mg->op->oblock) * cache->sectors_per_block; |
c6b4fcba JT |
1247 | o_region.count = cache->sectors_per_block; |
1248 | ||
1249 | c_region.bdev = cache->cache_dev->bdev; | |
b29d4986 | 1250 | c_region.sector = from_cblock(mg->op->cblock) * cache->sectors_per_block; |
c6b4fcba JT |
1251 | c_region.count = cache->sectors_per_block; |
1252 | ||
b29d4986 JT |
1253 | if (promote) |
1254 | r = dm_kcopyd_copy(cache->copier, &o_region, 1, &c_region, 0, copy_complete, &mg->k); | |
1255 | else | |
1256 | r = dm_kcopyd_copy(cache->copier, &c_region, 1, &o_region, 0, copy_complete, &mg->k); | |
c6b4fcba | 1257 | |
b29d4986 JT |
1258 | return r; |
1259 | } | |
1260 | ||
1261 | static void bio_drop_shared_lock(struct cache *cache, struct bio *bio) | |
1262 | { | |
1263 | size_t pb_data_size = get_per_bio_data_size(cache); | |
1264 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
1265 | ||
1266 | if (pb->cell && dm_cell_put_v2(cache->prison, pb->cell)) | |
1267 | free_prison_cell(cache, pb->cell); | |
1268 | pb->cell = NULL; | |
c6b4fcba JT |
1269 | } |
1270 | ||
4246a0b6 | 1271 | static void overwrite_endio(struct bio *bio) |
c9d28d5d JT |
1272 | { |
1273 | struct dm_cache_migration *mg = bio->bi_private; | |
1274 | struct cache *cache = mg->cache; | |
1275 | size_t pb_data_size = get_per_bio_data_size(cache); | |
1276 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
c9d28d5d | 1277 | |
80ae49aa MS |
1278 | dm_unhook_bio(&pb->hook_info, bio); |
1279 | ||
4e4cbee9 CH |
1280 | if (bio->bi_status) |
1281 | mg->k.input = bio->bi_status; | |
80ae49aa | 1282 | |
b29d4986 | 1283 | queue_continuation(mg->cache->wq, &mg->k); |
c9d28d5d JT |
1284 | } |
1285 | ||
b29d4986 JT |
1286 | static void overwrite(struct dm_cache_migration *mg, |
1287 | void (*continuation)(struct work_struct *)) | |
c9d28d5d | 1288 | { |
b29d4986 | 1289 | struct bio *bio = mg->overwrite_bio; |
c9d28d5d JT |
1290 | size_t pb_data_size = get_per_bio_data_size(mg->cache); |
1291 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
1292 | ||
1293 | dm_hook_bio(&pb->hook_info, bio, overwrite_endio, mg); | |
8c081b52 JT |
1294 | |
1295 | /* | |
b29d4986 JT |
1296 | * The overwrite bio is part of the copy operation, as such it does |
1297 | * not set/clear discard or dirty flags. | |
8c081b52 | 1298 | */ |
b29d4986 JT |
1299 | if (mg->op->op == POLICY_PROMOTE) |
1300 | remap_to_cache(mg->cache, bio, mg->op->cblock); | |
1301 | else | |
1302 | remap_to_origin(mg->cache, bio); | |
1303 | ||
1304 | init_continuation(&mg->k, continuation); | |
066dbaa3 | 1305 | accounted_request(mg->cache, bio); |
c9d28d5d JT |
1306 | } |
1307 | ||
b29d4986 JT |
1308 | /* |
1309 | * Migration steps: | |
1310 | * | |
1311 | * 1) exclusive lock preventing WRITEs | |
1312 | * 2) quiesce | |
1313 | * 3) copy or issue overwrite bio | |
1314 | * 4) upgrade to exclusive lock preventing READs and WRITEs | |
1315 | * 5) quiesce | |
1316 | * 6) update metadata and commit | |
1317 | * 7) unlock | |
1318 | */ | |
1319 | static void mg_complete(struct dm_cache_migration *mg, bool success) | |
c9d28d5d | 1320 | { |
b29d4986 JT |
1321 | struct bio_list bios; |
1322 | struct cache *cache = mg->cache; | |
1323 | struct policy_work *op = mg->op; | |
1324 | dm_cblock_t cblock = op->cblock; | |
1325 | ||
1326 | if (success) | |
1327 | update_stats(&cache->stats, op->op); | |
1328 | ||
1329 | switch (op->op) { | |
1330 | case POLICY_PROMOTE: | |
1331 | clear_discard(cache, oblock_to_dblock(cache, op->oblock)); | |
1332 | policy_complete_background_work(cache->policy, op, success); | |
1333 | ||
1334 | if (mg->overwrite_bio) { | |
1335 | if (success) | |
1336 | force_set_dirty(cache, cblock); | |
4e4cbee9 CH |
1337 | else if (mg->k.input) |
1338 | mg->overwrite_bio->bi_status = mg->k.input; | |
b29d4986 | 1339 | else |
4e4cbee9 | 1340 | mg->overwrite_bio->bi_status = BLK_STS_IOERR; |
b29d4986 JT |
1341 | bio_endio(mg->overwrite_bio); |
1342 | } else { | |
1343 | if (success) | |
1344 | force_clear_dirty(cache, cblock); | |
1345 | dec_io_migrations(cache); | |
1346 | } | |
1347 | break; | |
1348 | ||
1349 | case POLICY_DEMOTE: | |
1350 | /* | |
1351 | * We clear dirty here to update the nr_dirty counter. | |
1352 | */ | |
1353 | if (success) | |
1354 | force_clear_dirty(cache, cblock); | |
1355 | policy_complete_background_work(cache->policy, op, success); | |
1356 | dec_io_migrations(cache); | |
1357 | break; | |
1358 | ||
1359 | case POLICY_WRITEBACK: | |
1360 | if (success) | |
1361 | force_clear_dirty(cache, cblock); | |
1362 | policy_complete_background_work(cache->policy, op, success); | |
1363 | dec_io_migrations(cache); | |
1364 | break; | |
1365 | } | |
1366 | ||
1367 | bio_list_init(&bios); | |
1368 | if (mg->cell) { | |
1369 | if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios)) | |
1370 | free_prison_cell(cache, mg->cell); | |
1371 | } | |
1372 | ||
1373 | free_migration(mg); | |
1374 | defer_bios(cache, &bios); | |
1375 | wake_migration_worker(cache); | |
1376 | ||
1377 | background_work_end(cache); | |
c9d28d5d JT |
1378 | } |
1379 | ||
b29d4986 | 1380 | static void mg_success(struct work_struct *ws) |
c6b4fcba | 1381 | { |
b29d4986 JT |
1382 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1383 | mg_complete(mg, mg->k.input == 0); | |
c6b4fcba JT |
1384 | } |
1385 | ||
b29d4986 | 1386 | static void mg_update_metadata(struct work_struct *ws) |
7ae34e77 | 1387 | { |
b29d4986 JT |
1388 | int r; |
1389 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
c6b4fcba | 1390 | struct cache *cache = mg->cache; |
b29d4986 | 1391 | struct policy_work *op = mg->op; |
c6b4fcba | 1392 | |
b29d4986 JT |
1393 | switch (op->op) { |
1394 | case POLICY_PROMOTE: | |
1395 | r = dm_cache_insert_mapping(cache->cmd, op->cblock, op->oblock); | |
1396 | if (r) { | |
1397 | DMERR_LIMIT("%s: migration failed; couldn't insert mapping", | |
1398 | cache_device_name(cache)); | |
1399 | metadata_operation_failed(cache, "dm_cache_insert_mapping", r); | |
7ae34e77 | 1400 | |
b29d4986 JT |
1401 | mg_complete(mg, false); |
1402 | return; | |
1403 | } | |
1404 | mg_complete(mg, true); | |
1405 | break; | |
c9d28d5d | 1406 | |
b29d4986 JT |
1407 | case POLICY_DEMOTE: |
1408 | r = dm_cache_remove_mapping(cache->cmd, op->cblock); | |
1409 | if (r) { | |
1410 | DMERR_LIMIT("%s: migration failed; couldn't update on disk metadata", | |
1411 | cache_device_name(cache)); | |
1412 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); | |
c6b4fcba | 1413 | |
b29d4986 | 1414 | mg_complete(mg, false); |
c9d28d5d JT |
1415 | return; |
1416 | } | |
c9d28d5d | 1417 | |
b29d4986 JT |
1418 | /* |
1419 | * It would be nice if we only had to commit when a REQ_FLUSH | |
1420 | * comes through. But there's one scenario that we have to | |
1421 | * look out for: | |
1422 | * | |
1423 | * - vblock x in a cache block | |
1424 | * - domotion occurs | |
1425 | * - cache block gets reallocated and over written | |
1426 | * - crash | |
1427 | * | |
1428 | * When we recover, because there was no commit the cache will | |
1429 | * rollback to having the data for vblock x in the cache block. | |
1430 | * But the cache block has since been overwritten, so it'll end | |
1431 | * up pointing to data that was never in 'x' during the history | |
1432 | * of the device. | |
1433 | * | |
1434 | * To avoid this issue we require a commit as part of the | |
1435 | * demotion operation. | |
1436 | */ | |
1437 | init_continuation(&mg->k, mg_success); | |
1438 | continue_after_commit(&cache->committer, &mg->k); | |
1439 | schedule_commit(&cache->committer); | |
1440 | break; | |
1441 | ||
1442 | case POLICY_WRITEBACK: | |
1443 | mg_complete(mg, true); | |
1444 | break; | |
7ae34e77 | 1445 | } |
c6b4fcba JT |
1446 | } |
1447 | ||
b29d4986 | 1448 | static void mg_update_metadata_after_copy(struct work_struct *ws) |
c6b4fcba | 1449 | { |
b29d4986 JT |
1450 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1451 | ||
1452 | /* | |
1453 | * Did the copy succeed? | |
1454 | */ | |
1455 | if (mg->k.input) | |
1456 | mg_complete(mg, false); | |
c6b4fcba | 1457 | else |
b29d4986 | 1458 | mg_update_metadata(ws); |
c6b4fcba JT |
1459 | } |
1460 | ||
b29d4986 | 1461 | static void mg_upgrade_lock(struct work_struct *ws) |
c6b4fcba | 1462 | { |
b29d4986 JT |
1463 | int r; |
1464 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
c6b4fcba | 1465 | |
b29d4986 JT |
1466 | /* |
1467 | * Did the copy succeed? | |
1468 | */ | |
1469 | if (mg->k.input) | |
1470 | mg_complete(mg, false); | |
c6b4fcba | 1471 | |
c9d28d5d | 1472 | else { |
b29d4986 JT |
1473 | /* |
1474 | * Now we want the lock to prevent both reads and writes. | |
1475 | */ | |
1476 | r = dm_cell_lock_promote_v2(mg->cache->prison, mg->cell, | |
1477 | READ_WRITE_LOCK_LEVEL); | |
1478 | if (r < 0) | |
1479 | mg_complete(mg, false); | |
c6b4fcba | 1480 | |
b29d4986 JT |
1481 | else if (r) |
1482 | quiesce(mg, mg_update_metadata); | |
c6b4fcba | 1483 | |
b29d4986 JT |
1484 | else |
1485 | mg_update_metadata(ws); | |
c9d28d5d | 1486 | } |
c6b4fcba JT |
1487 | } |
1488 | ||
ec544ec9 JT |
1489 | static void mg_full_copy(struct work_struct *ws) |
1490 | { | |
1491 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
1492 | struct cache *cache = mg->cache; | |
1493 | struct policy_work *op = mg->op; | |
1494 | bool is_policy_promote = (op->op == POLICY_PROMOTE); | |
1495 | ||
1496 | if ((!is_policy_promote && !is_dirty(cache, op->cblock)) || | |
1497 | is_discarded_oblock(cache, op->oblock)) { | |
1498 | mg_upgrade_lock(ws); | |
1499 | return; | |
1500 | } | |
1501 | ||
1502 | init_continuation(&mg->k, mg_upgrade_lock); | |
1503 | ||
1504 | if (copy(mg, is_policy_promote)) { | |
1505 | DMERR_LIMIT("%s: migration copy failed", cache_device_name(cache)); | |
1506 | mg->k.input = BLK_STS_IOERR; | |
1507 | mg_complete(mg, false); | |
1508 | } | |
1509 | } | |
1510 | ||
b29d4986 | 1511 | static void mg_copy(struct work_struct *ws) |
c6b4fcba | 1512 | { |
b29d4986 | 1513 | struct dm_cache_migration *mg = ws_to_mg(ws); |
c6b4fcba | 1514 | |
b29d4986 | 1515 | if (mg->overwrite_bio) { |
ec544ec9 JT |
1516 | /* |
1517 | * No exclusive lock was held when we last checked if the bio | |
1518 | * was optimisable. So we have to check again in case things | |
1519 | * have changed (eg, the block may no longer be discarded). | |
1520 | */ | |
1521 | if (!optimisable_bio(mg->cache, mg->overwrite_bio, mg->op->oblock)) { | |
1522 | /* | |
1523 | * Fallback to a real full copy after doing some tidying up. | |
1524 | */ | |
1525 | bool rb = bio_detain_shared(mg->cache, mg->op->oblock, mg->overwrite_bio); | |
1526 | BUG_ON(rb); /* An exclussive lock must _not_ be held for this block */ | |
1527 | mg->overwrite_bio = NULL; | |
1528 | inc_io_migrations(mg->cache); | |
1529 | mg_full_copy(ws); | |
1530 | return; | |
1531 | } | |
1532 | ||
b29d4986 JT |
1533 | /* |
1534 | * It's safe to do this here, even though it's new data | |
1535 | * because all IO has been locked out of the block. | |
1536 | * | |
1537 | * mg_lock_writes() already took READ_WRITE_LOCK_LEVEL | |
1538 | * so _not_ using mg_upgrade_lock() as continutation. | |
1539 | */ | |
1540 | overwrite(mg, mg_update_metadata_after_copy); | |
c6b4fcba | 1541 | |
ec544ec9 JT |
1542 | } else |
1543 | mg_full_copy(ws); | |
c6b4fcba JT |
1544 | } |
1545 | ||
b29d4986 | 1546 | static int mg_lock_writes(struct dm_cache_migration *mg) |
c6b4fcba | 1547 | { |
b29d4986 JT |
1548 | int r; |
1549 | struct dm_cell_key_v2 key; | |
c6b4fcba | 1550 | struct cache *cache = mg->cache; |
b29d4986 | 1551 | struct dm_bio_prison_cell_v2 *prealloc; |
c6b4fcba | 1552 | |
b29d4986 JT |
1553 | prealloc = alloc_prison_cell(cache); |
1554 | if (!prealloc) { | |
1555 | DMERR_LIMIT("%s: alloc_prison_cell failed", cache_device_name(cache)); | |
1556 | mg_complete(mg, false); | |
1557 | return -ENOMEM; | |
1558 | } | |
c6b4fcba | 1559 | |
b29d4986 JT |
1560 | /* |
1561 | * Prevent writes to the block, but allow reads to continue. | |
1562 | * Unless we're using an overwrite bio, in which case we lock | |
1563 | * everything. | |
1564 | */ | |
1565 | build_key(mg->op->oblock, oblock_succ(mg->op->oblock), &key); | |
1566 | r = dm_cell_lock_v2(cache->prison, &key, | |
1567 | mg->overwrite_bio ? READ_WRITE_LOCK_LEVEL : WRITE_LOCK_LEVEL, | |
1568 | prealloc, &mg->cell); | |
1569 | if (r < 0) { | |
1570 | free_prison_cell(cache, prealloc); | |
1571 | mg_complete(mg, false); | |
1572 | return r; | |
1573 | } | |
c6b4fcba | 1574 | |
b29d4986 JT |
1575 | if (mg->cell != prealloc) |
1576 | free_prison_cell(cache, prealloc); | |
c6b4fcba | 1577 | |
b29d4986 JT |
1578 | if (r == 0) |
1579 | mg_copy(&mg->k.ws); | |
1580 | else | |
1581 | quiesce(mg, mg_copy); | |
c6b4fcba | 1582 | |
b29d4986 | 1583 | return 0; |
c6b4fcba JT |
1584 | } |
1585 | ||
b29d4986 | 1586 | static int mg_start(struct cache *cache, struct policy_work *op, struct bio *bio) |
c6b4fcba | 1587 | { |
b29d4986 | 1588 | struct dm_cache_migration *mg; |
c6b4fcba | 1589 | |
b29d4986 JT |
1590 | if (!background_work_begin(cache)) { |
1591 | policy_complete_background_work(cache->policy, op, false); | |
1592 | return -EPERM; | |
1593 | } | |
2ee57d58 | 1594 | |
b29d4986 JT |
1595 | mg = alloc_migration(cache); |
1596 | if (!mg) { | |
1597 | policy_complete_background_work(cache->policy, op, false); | |
1598 | background_work_end(cache); | |
1599 | return -ENOMEM; | |
1600 | } | |
2ee57d58 | 1601 | |
b29d4986 | 1602 | memset(mg, 0, sizeof(*mg)); |
7ae34e77 | 1603 | |
7ae34e77 | 1604 | mg->cache = cache; |
b29d4986 JT |
1605 | mg->op = op; |
1606 | mg->overwrite_bio = bio; | |
1607 | ||
1608 | if (!bio) | |
1609 | inc_io_migrations(cache); | |
7ae34e77 | 1610 | |
b29d4986 | 1611 | return mg_lock_writes(mg); |
7ae34e77 JT |
1612 | } |
1613 | ||
c6b4fcba | 1614 | /*---------------------------------------------------------------- |
b29d4986 | 1615 | * invalidation processing |
c6b4fcba | 1616 | *--------------------------------------------------------------*/ |
c6b4fcba | 1617 | |
b29d4986 | 1618 | static void invalidate_complete(struct dm_cache_migration *mg, bool success) |
c6b4fcba | 1619 | { |
b29d4986 JT |
1620 | struct bio_list bios; |
1621 | struct cache *cache = mg->cache; | |
c6b4fcba | 1622 | |
b29d4986 JT |
1623 | bio_list_init(&bios); |
1624 | if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios)) | |
1625 | free_prison_cell(cache, mg->cell); | |
c6b4fcba | 1626 | |
b29d4986 JT |
1627 | if (!success && mg->overwrite_bio) |
1628 | bio_io_error(mg->overwrite_bio); | |
c6b4fcba | 1629 | |
b29d4986 JT |
1630 | free_migration(mg); |
1631 | defer_bios(cache, &bios); | |
c6b4fcba | 1632 | |
b29d4986 | 1633 | background_work_end(cache); |
c6b4fcba JT |
1634 | } |
1635 | ||
b29d4986 | 1636 | static void invalidate_completed(struct work_struct *ws) |
c6b4fcba | 1637 | { |
b29d4986 JT |
1638 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1639 | invalidate_complete(mg, !mg->k.input); | |
c6b4fcba JT |
1640 | } |
1641 | ||
b29d4986 | 1642 | static int invalidate_cblock(struct cache *cache, dm_cblock_t cblock) |
651f5fa2 | 1643 | { |
b29d4986 JT |
1644 | int r = policy_invalidate_mapping(cache->policy, cblock); |
1645 | if (!r) { | |
1646 | r = dm_cache_remove_mapping(cache->cmd, cblock); | |
1647 | if (r) { | |
1648 | DMERR_LIMIT("%s: invalidation failed; couldn't update on disk metadata", | |
1649 | cache_device_name(cache)); | |
1650 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); | |
651f5fa2 JT |
1651 | } |
1652 | ||
b29d4986 JT |
1653 | } else if (r == -ENODATA) { |
1654 | /* | |
1655 | * Harmless, already unmapped. | |
1656 | */ | |
1657 | r = 0; | |
651f5fa2 | 1658 | |
b29d4986 JT |
1659 | } else |
1660 | DMERR("%s: policy_invalidate_mapping failed", cache_device_name(cache)); | |
2ee57d58 | 1661 | |
b29d4986 | 1662 | return r; |
651f5fa2 JT |
1663 | } |
1664 | ||
b29d4986 | 1665 | static void invalidate_remove(struct work_struct *ws) |
651f5fa2 | 1666 | { |
b29d4986 JT |
1667 | int r; |
1668 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
1669 | struct cache *cache = mg->cache; | |
651f5fa2 | 1670 | |
b29d4986 JT |
1671 | r = invalidate_cblock(cache, mg->invalidate_cblock); |
1672 | if (r) { | |
1673 | invalidate_complete(mg, false); | |
1674 | return; | |
651f5fa2 | 1675 | } |
9153df74 | 1676 | |
b29d4986 JT |
1677 | init_continuation(&mg->k, invalidate_completed); |
1678 | continue_after_commit(&cache->committer, &mg->k); | |
1679 | remap_to_origin_clear_discard(cache, mg->overwrite_bio, mg->invalidate_oblock); | |
1680 | mg->overwrite_bio = NULL; | |
1681 | schedule_commit(&cache->committer); | |
651f5fa2 JT |
1682 | } |
1683 | ||
b29d4986 | 1684 | static int invalidate_lock(struct dm_cache_migration *mg) |
651f5fa2 | 1685 | { |
b29d4986 JT |
1686 | int r; |
1687 | struct dm_cell_key_v2 key; | |
1688 | struct cache *cache = mg->cache; | |
1689 | struct dm_bio_prison_cell_v2 *prealloc; | |
651f5fa2 | 1690 | |
b29d4986 JT |
1691 | prealloc = alloc_prison_cell(cache); |
1692 | if (!prealloc) { | |
1693 | invalidate_complete(mg, false); | |
1694 | return -ENOMEM; | |
651f5fa2 JT |
1695 | } |
1696 | ||
b29d4986 JT |
1697 | build_key(mg->invalidate_oblock, oblock_succ(mg->invalidate_oblock), &key); |
1698 | r = dm_cell_lock_v2(cache->prison, &key, | |
1699 | READ_WRITE_LOCK_LEVEL, prealloc, &mg->cell); | |
1700 | if (r < 0) { | |
1701 | free_prison_cell(cache, prealloc); | |
1702 | invalidate_complete(mg, false); | |
1703 | return r; | |
651f5fa2 | 1704 | } |
9153df74 | 1705 | |
b29d4986 JT |
1706 | if (mg->cell != prealloc) |
1707 | free_prison_cell(cache, prealloc); | |
651f5fa2 | 1708 | |
b29d4986 JT |
1709 | if (r) |
1710 | quiesce(mg, invalidate_remove); | |
651f5fa2 | 1711 | |
b29d4986 JT |
1712 | else { |
1713 | /* | |
1714 | * We can't call invalidate_remove() directly here because we | |
1715 | * might still be in request context. | |
1716 | */ | |
1717 | init_continuation(&mg->k, invalidate_remove); | |
1718 | queue_work(cache->wq, &mg->k.ws); | |
1719 | } | |
fb4100ae | 1720 | |
fb4100ae JT |
1721 | return 0; |
1722 | } | |
1723 | ||
b29d4986 JT |
1724 | static int invalidate_start(struct cache *cache, dm_cblock_t cblock, |
1725 | dm_oblock_t oblock, struct bio *bio) | |
fb4100ae | 1726 | { |
b29d4986 | 1727 | struct dm_cache_migration *mg; |
2ee57d58 | 1728 | |
b29d4986 JT |
1729 | if (!background_work_begin(cache)) |
1730 | return -EPERM; | |
c6b4fcba | 1731 | |
b29d4986 JT |
1732 | mg = alloc_migration(cache); |
1733 | if (!mg) { | |
1734 | background_work_end(cache); | |
1735 | return -ENOMEM; | |
7ae34e77 | 1736 | } |
c6b4fcba | 1737 | |
b29d4986 | 1738 | memset(mg, 0, sizeof(*mg)); |
c6b4fcba | 1739 | |
b29d4986 JT |
1740 | mg->cache = cache; |
1741 | mg->overwrite_bio = bio; | |
1742 | mg->invalidate_cblock = cblock; | |
1743 | mg->invalidate_oblock = oblock; | |
c6b4fcba | 1744 | |
b29d4986 | 1745 | return invalidate_lock(mg); |
c6b4fcba | 1746 | } |
c6b4fcba | 1747 | |
b29d4986 JT |
1748 | /*---------------------------------------------------------------- |
1749 | * bio processing | |
1750 | *--------------------------------------------------------------*/ | |
c6b4fcba | 1751 | |
b29d4986 JT |
1752 | enum busy { |
1753 | IDLE, | |
b29d4986 JT |
1754 | BUSY |
1755 | }; | |
c6b4fcba | 1756 | |
b29d4986 | 1757 | static enum busy spare_migration_bandwidth(struct cache *cache) |
651f5fa2 | 1758 | { |
701e03e4 | 1759 | bool idle = iot_idle_for(&cache->tracker, HZ); |
a59db676 | 1760 | sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) * |
c6b4fcba | 1761 | cache->sectors_per_block; |
651f5fa2 | 1762 | |
49b7f768 JT |
1763 | if (idle && current_volume <= cache->migration_threshold) |
1764 | return IDLE; | |
b29d4986 | 1765 | else |
49b7f768 | 1766 | return BUSY; |
651f5fa2 JT |
1767 | } |
1768 | ||
c6b4fcba | 1769 | static void inc_hit_counter(struct cache *cache, struct bio *bio) |
c6b4fcba | 1770 | { |
c6b4fcba JT |
1771 | atomic_inc(bio_data_dir(bio) == READ ? |
1772 | &cache->stats.read_hit : &cache->stats.write_hit); | |
c6b4fcba JT |
1773 | } |
1774 | ||
c6b4fcba | 1775 | static void inc_miss_counter(struct cache *cache, struct bio *bio) |
028ae9f7 | 1776 | { |
c6b4fcba JT |
1777 | atomic_inc(bio_data_dir(bio) == READ ? |
1778 | &cache->stats.read_miss : &cache->stats.write_miss); | |
1779 | } | |
028ae9f7 | 1780 | |
fb4100ae | 1781 | /*----------------------------------------------------------------*/ |
028ae9f7 | 1782 | |
b29d4986 JT |
1783 | static int map_bio(struct cache *cache, struct bio *bio, dm_oblock_t block, |
1784 | bool *commit_needed) | |
c6b4fcba | 1785 | { |
b29d4986 JT |
1786 | int r, data_dir; |
1787 | bool rb, background_queued; | |
1788 | dm_cblock_t cblock; | |
1789 | size_t pb_data_size = get_per_bio_data_size(cache); | |
1790 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
c6b4fcba | 1791 | |
b29d4986 | 1792 | *commit_needed = false; |
c6b4fcba | 1793 | |
b29d4986 JT |
1794 | rb = bio_detain_shared(cache, block, bio); |
1795 | if (!rb) { | |
c6b4fcba | 1796 | /* |
b29d4986 JT |
1797 | * An exclusive lock is held for this block, so we have to |
1798 | * wait. We set the commit_needed flag so the current | |
1799 | * transaction will be committed asap, allowing this lock | |
1800 | * to be dropped. | |
c6b4fcba | 1801 | */ |
b29d4986 JT |
1802 | *commit_needed = true; |
1803 | return DM_MAPIO_SUBMITTED; | |
651f5fa2 | 1804 | } |
9153df74 | 1805 | |
b29d4986 | 1806 | data_dir = bio_data_dir(bio); |
651f5fa2 | 1807 | |
b29d4986 JT |
1808 | if (optimisable_bio(cache, bio, block)) { |
1809 | struct policy_work *op = NULL; | |
fb4100ae | 1810 | |
b29d4986 JT |
1811 | r = policy_lookup_with_work(cache->policy, block, &cblock, data_dir, true, &op); |
1812 | if (unlikely(r && r != -ENOENT)) { | |
1813 | DMERR_LIMIT("%s: policy_lookup_with_work() failed with r = %d", | |
1814 | cache_device_name(cache), r); | |
1815 | bio_io_error(bio); | |
1816 | return DM_MAPIO_SUBMITTED; | |
c6b4fcba JT |
1817 | } |
1818 | ||
b29d4986 JT |
1819 | if (r == -ENOENT && op) { |
1820 | bio_drop_shared_lock(cache, bio); | |
1821 | BUG_ON(op->op != POLICY_PROMOTE); | |
1822 | mg_start(cache, op, bio); | |
1823 | return DM_MAPIO_SUBMITTED; | |
1824 | } | |
1825 | } else { | |
1826 | r = policy_lookup(cache->policy, block, &cblock, data_dir, false, &background_queued); | |
1827 | if (unlikely(r && r != -ENOENT)) { | |
1828 | DMERR_LIMIT("%s: policy_lookup() failed with r = %d", | |
1829 | cache_device_name(cache), r); | |
1830 | bio_io_error(bio); | |
1831 | return DM_MAPIO_SUBMITTED; | |
1832 | } | |
c6b4fcba | 1833 | |
b29d4986 JT |
1834 | if (background_queued) |
1835 | wake_migration_worker(cache); | |
c6b4fcba JT |
1836 | } |
1837 | ||
b29d4986 JT |
1838 | if (r == -ENOENT) { |
1839 | /* | |
1840 | * Miss. | |
1841 | */ | |
1842 | inc_miss_counter(cache, bio); | |
1843 | if (pb->req_nr == 0) { | |
1844 | accounted_begin(cache, bio); | |
1845 | remap_to_origin_clear_discard(cache, bio, block); | |
651f5fa2 | 1846 | |
b29d4986 | 1847 | } else { |
2ee57d58 | 1848 | /* |
b29d4986 JT |
1849 | * This is a duplicate writethrough io that is no |
1850 | * longer needed because the block has been demoted. | |
2ee57d58 | 1851 | */ |
b29d4986 JT |
1852 | bio_endio(bio); |
1853 | return DM_MAPIO_SUBMITTED; | |
1854 | } | |
1855 | } else { | |
1856 | /* | |
1857 | * Hit. | |
1858 | */ | |
1859 | inc_hit_counter(cache, bio); | |
651f5fa2 | 1860 | |
b29d4986 JT |
1861 | /* |
1862 | * Passthrough always maps to the origin, invalidating any | |
1863 | * cache blocks that are written to. | |
1864 | */ | |
1865 | if (passthrough_mode(&cache->features)) { | |
2ee57d58 | 1866 | if (bio_data_dir(bio) == WRITE) { |
b29d4986 | 1867 | bio_drop_shared_lock(cache, bio); |
2ee57d58 | 1868 | atomic_inc(&cache->stats.demotion); |
b29d4986 JT |
1869 | invalidate_start(cache, cblock, block, bio); |
1870 | } else | |
2ee57d58 | 1871 | remap_to_origin_clear_discard(cache, bio, block); |
651f5fa2 | 1872 | |
2ee57d58 | 1873 | } else { |
b29d4986 JT |
1874 | if (bio_data_dir(bio) == WRITE && writethrough_mode(&cache->features) && |
1875 | !is_dirty(cache, cblock)) { | |
1876 | remap_to_origin_then_cache(cache, bio, block, cblock); | |
1877 | accounted_begin(cache, bio); | |
1878 | } else | |
1879 | remap_to_cache_dirty(cache, bio, block, cblock); | |
2ee57d58 | 1880 | } |
c6b4fcba | 1881 | } |
651f5fa2 | 1882 | |
651f5fa2 | 1883 | /* |
b29d4986 | 1884 | * dm core turns FUA requests into a separate payload and FLUSH req. |
651f5fa2 | 1885 | */ |
b29d4986 | 1886 | if (bio->bi_opf & REQ_FUA) { |
651f5fa2 | 1887 | /* |
b29d4986 JT |
1888 | * issue_after_commit will call accounted_begin a second time. So |
1889 | * we call accounted_complete() to avoid double accounting. | |
651f5fa2 | 1890 | */ |
b29d4986 JT |
1891 | accounted_complete(cache, bio); |
1892 | issue_after_commit(&cache->committer, bio); | |
1893 | *commit_needed = true; | |
1894 | return DM_MAPIO_SUBMITTED; | |
651f5fa2 JT |
1895 | } |
1896 | ||
b29d4986 | 1897 | return DM_MAPIO_REMAPPED; |
651f5fa2 JT |
1898 | } |
1899 | ||
b29d4986 | 1900 | static bool process_bio(struct cache *cache, struct bio *bio) |
c6b4fcba | 1901 | { |
b29d4986 | 1902 | bool commit_needed; |
c6b4fcba | 1903 | |
b29d4986 JT |
1904 | if (map_bio(cache, bio, get_bio_block(cache, bio), &commit_needed) == DM_MAPIO_REMAPPED) |
1905 | generic_make_request(bio); | |
c6b4fcba | 1906 | |
b29d4986 | 1907 | return commit_needed; |
c6b4fcba JT |
1908 | } |
1909 | ||
028ae9f7 JT |
1910 | /* |
1911 | * A non-zero return indicates read_only or fail_io mode. | |
1912 | */ | |
1913 | static int commit(struct cache *cache, bool clean_shutdown) | |
e2e74d61 | 1914 | { |
028ae9f7 | 1915 | int r; |
e2e74d61 | 1916 | |
028ae9f7 JT |
1917 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
1918 | return -EINVAL; | |
e2e74d61 | 1919 | |
028ae9f7 JT |
1920 | atomic_inc(&cache->stats.commit_count); |
1921 | r = dm_cache_commit(cache->cmd, clean_shutdown); | |
1922 | if (r) | |
1923 | metadata_operation_failed(cache, "dm_cache_commit", r); | |
e2e74d61 | 1924 | |
028ae9f7 | 1925 | return r; |
e2e74d61 JT |
1926 | } |
1927 | ||
b29d4986 JT |
1928 | /* |
1929 | * Used by the batcher. | |
1930 | */ | |
4e4cbee9 | 1931 | static blk_status_t commit_op(void *context) |
c6b4fcba | 1932 | { |
b29d4986 | 1933 | struct cache *cache = context; |
c6b4fcba | 1934 | |
b29d4986 | 1935 | if (dm_cache_changed_this_transaction(cache->cmd)) |
4e4cbee9 | 1936 | return errno_to_blk_status(commit(cache, false)); |
c6b4fcba | 1937 | |
b29d4986 | 1938 | return 0; |
c6b4fcba JT |
1939 | } |
1940 | ||
b29d4986 | 1941 | /*----------------------------------------------------------------*/ |
65790ff9 | 1942 | |
b29d4986 | 1943 | static bool process_flush_bio(struct cache *cache, struct bio *bio) |
65790ff9 | 1944 | { |
b29d4986 JT |
1945 | size_t pb_data_size = get_per_bio_data_size(cache); |
1946 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
65790ff9 | 1947 | |
b29d4986 JT |
1948 | if (!pb->req_nr) |
1949 | remap_to_origin(cache, bio); | |
1950 | else | |
1951 | remap_to_cache(cache, bio, 0); | |
65790ff9 | 1952 | |
b29d4986 JT |
1953 | issue_after_commit(&cache->committer, bio); |
1954 | return true; | |
65790ff9 JT |
1955 | } |
1956 | ||
b29d4986 | 1957 | static bool process_discard_bio(struct cache *cache, struct bio *bio) |
65790ff9 | 1958 | { |
b29d4986 | 1959 | dm_dblock_t b, e; |
65790ff9 | 1960 | |
b29d4986 JT |
1961 | // FIXME: do we need to lock the region? Or can we just assume the |
1962 | // user wont be so foolish as to issue discard concurrently with | |
1963 | // other IO? | |
1964 | calc_discard_block_range(cache, bio, &b, &e); | |
1965 | while (b != e) { | |
1966 | set_discard(cache, b); | |
1967 | b = to_dblock(from_dblock(b) + 1); | |
651f5fa2 | 1968 | } |
65790ff9 | 1969 | |
b29d4986 | 1970 | bio_endio(bio); |
65790ff9 | 1971 | |
b29d4986 | 1972 | return false; |
c6b4fcba JT |
1973 | } |
1974 | ||
b29d4986 | 1975 | static void process_deferred_bios(struct work_struct *ws) |
66cb1910 | 1976 | { |
b29d4986 | 1977 | struct cache *cache = container_of(ws, struct cache, deferred_bio_worker); |
66cb1910 | 1978 | |
c6b4fcba | 1979 | unsigned long flags; |
b29d4986 | 1980 | bool commit_needed = false; |
c6b4fcba JT |
1981 | struct bio_list bios; |
1982 | struct bio *bio; | |
66cb1910 | 1983 | |
c6b4fcba | 1984 | bio_list_init(&bios); |
c6b4fcba | 1985 | |
c6b4fcba | 1986 | spin_lock_irqsave(&cache->lock, flags); |
b29d4986 JT |
1987 | bio_list_merge(&bios, &cache->deferred_bios); |
1988 | bio_list_init(&cache->deferred_bios); | |
c6b4fcba | 1989 | spin_unlock_irqrestore(&cache->lock, flags); |
c6b4fcba | 1990 | |
b29d4986 JT |
1991 | while ((bio = bio_list_pop(&bios))) { |
1992 | if (bio->bi_opf & REQ_PREFLUSH) | |
1993 | commit_needed = process_flush_bio(cache, bio) || commit_needed; | |
c6b4fcba | 1994 | |
b29d4986 JT |
1995 | else if (bio_op(bio) == REQ_OP_DISCARD) |
1996 | commit_needed = process_discard_bio(cache, bio) || commit_needed; | |
1997 | ||
1998 | else | |
1999 | commit_needed = process_bio(cache, bio) || commit_needed; | |
2000 | } | |
2001 | ||
2002 | if (commit_needed) | |
2003 | schedule_commit(&cache->committer); | |
c6b4fcba JT |
2004 | } |
2005 | ||
b29d4986 | 2006 | static void process_deferred_writethrough_bios(struct work_struct *ws) |
651f5fa2 | 2007 | { |
b29d4986 JT |
2008 | struct cache *cache = container_of(ws, struct cache, deferred_writethrough_worker); |
2009 | ||
651f5fa2 | 2010 | unsigned long flags; |
e2e74d61 JT |
2011 | struct bio_list bios; |
2012 | struct bio *bio; | |
2013 | ||
2014 | bio_list_init(&bios); | |
651f5fa2 | 2015 | |
651f5fa2 | 2016 | spin_lock_irqsave(&cache->lock, flags); |
e2e74d61 JT |
2017 | bio_list_merge(&bios, &cache->deferred_writethrough_bios); |
2018 | bio_list_init(&cache->deferred_writethrough_bios); | |
651f5fa2 JT |
2019 | spin_unlock_irqrestore(&cache->lock, flags); |
2020 | ||
8c081b52 | 2021 | /* |
b29d4986 | 2022 | * These bios have already been through accounted_begin() |
8c081b52 | 2023 | */ |
e2e74d61 | 2024 | while ((bio = bio_list_pop(&bios))) |
b29d4986 | 2025 | generic_make_request(bio); |
651f5fa2 JT |
2026 | } |
2027 | ||
c6b4fcba JT |
2028 | /*---------------------------------------------------------------- |
2029 | * Main worker loop | |
2030 | *--------------------------------------------------------------*/ | |
651f5fa2 JT |
2031 | |
2032 | static void requeue_deferred_bios(struct cache *cache) | |
c6b4fcba JT |
2033 | { |
2034 | struct bio *bio; | |
2035 | struct bio_list bios; | |
2036 | ||
2037 | bio_list_init(&bios); | |
2038 | bio_list_merge(&bios, &cache->deferred_bios); | |
2039 | bio_list_init(&cache->deferred_bios); | |
2040 | ||
4246a0b6 | 2041 | while ((bio = bio_list_pop(&bios))) { |
4e4cbee9 | 2042 | bio->bi_status = BLK_STS_DM_REQUEUE; |
4246a0b6 CH |
2043 | bio_endio(bio); |
2044 | } | |
c6b4fcba JT |
2045 | } |
2046 | ||
c6b4fcba JT |
2047 | /* |
2048 | * We want to commit periodically so that not too much | |
2049 | * unwritten metadata builds up. | |
2050 | */ | |
2051 | static void do_waker(struct work_struct *ws) | |
2052 | { | |
2053 | struct cache *cache = container_of(to_delayed_work(ws), struct cache, waker); | |
b29d4986 | 2054 | |
fba10109 | 2055 | policy_tick(cache->policy, true); |
b29d4986 JT |
2056 | wake_migration_worker(cache); |
2057 | schedule_commit(&cache->committer); | |
c6b4fcba JT |
2058 | queue_delayed_work(cache->wq, &cache->waker, COMMIT_PERIOD); |
2059 | } | |
2060 | ||
b29d4986 | 2061 | static void check_migrations(struct work_struct *ws) |
c6b4fcba | 2062 | { |
b29d4986 JT |
2063 | int r; |
2064 | struct policy_work *op; | |
2065 | struct cache *cache = container_of(ws, struct cache, migration_worker); | |
2066 | enum busy b; | |
c6b4fcba | 2067 | |
b29d4986 JT |
2068 | for (;;) { |
2069 | b = spare_migration_bandwidth(cache); | |
c6b4fcba | 2070 | |
b29d4986 JT |
2071 | r = policy_get_background_work(cache->policy, b == IDLE, &op); |
2072 | if (r == -ENODATA) | |
2073 | break; | |
2074 | ||
2075 | if (r) { | |
2076 | DMERR_LIMIT("%s: policy_background_work failed", | |
2077 | cache_device_name(cache)); | |
2078 | break; | |
2079 | } | |
2080 | ||
2081 | r = mg_start(cache, op, NULL); | |
2082 | if (r) | |
2083 | break; | |
2084 | } | |
c6b4fcba JT |
2085 | } |
2086 | ||
2087 | /*---------------------------------------------------------------- | |
2088 | * Target methods | |
2089 | *--------------------------------------------------------------*/ | |
2090 | ||
2091 | /* | |
2092 | * This function gets called on the error paths of the constructor, so we | |
2093 | * have to cope with a partially initialised struct. | |
2094 | */ | |
2095 | static void destroy(struct cache *cache) | |
2096 | { | |
2097 | unsigned i; | |
2098 | ||
6f65985e | 2099 | mempool_destroy(cache->migration_pool); |
c6b4fcba | 2100 | |
c6b4fcba | 2101 | if (cache->prison) |
b29d4986 | 2102 | dm_bio_prison_destroy_v2(cache->prison); |
c6b4fcba JT |
2103 | |
2104 | if (cache->wq) | |
2105 | destroy_workqueue(cache->wq); | |
2106 | ||
2107 | if (cache->dirty_bitset) | |
2108 | free_bitset(cache->dirty_bitset); | |
2109 | ||
2110 | if (cache->discard_bitset) | |
2111 | free_bitset(cache->discard_bitset); | |
2112 | ||
2113 | if (cache->copier) | |
2114 | dm_kcopyd_client_destroy(cache->copier); | |
2115 | ||
2116 | if (cache->cmd) | |
2117 | dm_cache_metadata_close(cache->cmd); | |
2118 | ||
2119 | if (cache->metadata_dev) | |
2120 | dm_put_device(cache->ti, cache->metadata_dev); | |
2121 | ||
2122 | if (cache->origin_dev) | |
2123 | dm_put_device(cache->ti, cache->origin_dev); | |
2124 | ||
2125 | if (cache->cache_dev) | |
2126 | dm_put_device(cache->ti, cache->cache_dev); | |
2127 | ||
2128 | if (cache->policy) | |
2129 | dm_cache_policy_destroy(cache->policy); | |
2130 | ||
2131 | for (i = 0; i < cache->nr_ctr_args ; i++) | |
2132 | kfree(cache->ctr_args[i]); | |
2133 | kfree(cache->ctr_args); | |
2134 | ||
2135 | kfree(cache); | |
2136 | } | |
2137 | ||
2138 | static void cache_dtr(struct dm_target *ti) | |
2139 | { | |
2140 | struct cache *cache = ti->private; | |
2141 | ||
2142 | destroy(cache); | |
2143 | } | |
2144 | ||
2145 | static sector_t get_dev_size(struct dm_dev *dev) | |
2146 | { | |
2147 | return i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
2148 | } | |
2149 | ||
2150 | /*----------------------------------------------------------------*/ | |
2151 | ||
2152 | /* | |
2153 | * Construct a cache device mapping. | |
2154 | * | |
2155 | * cache <metadata dev> <cache dev> <origin dev> <block size> | |
2156 | * <#feature args> [<feature arg>]* | |
2157 | * <policy> <#policy args> [<policy arg>]* | |
2158 | * | |
2159 | * metadata dev : fast device holding the persistent metadata | |
2160 | * cache dev : fast device holding cached data blocks | |
2161 | * origin dev : slow device holding original data blocks | |
2162 | * block size : cache unit size in sectors | |
2163 | * | |
2164 | * #feature args : number of feature arguments passed | |
2165 | * feature args : writethrough. (The default is writeback.) | |
2166 | * | |
2167 | * policy : the replacement policy to use | |
2168 | * #policy args : an even number of policy arguments corresponding | |
2169 | * to key/value pairs passed to the policy | |
2170 | * policy args : key/value pairs passed to the policy | |
2171 | * E.g. 'sequential_threshold 1024' | |
2172 | * See cache-policies.txt for details. | |
2173 | * | |
2174 | * Optional feature arguments are: | |
2175 | * writethrough : write through caching that prohibits cache block | |
2176 | * content from being different from origin block content. | |
2177 | * Without this argument, the default behaviour is to write | |
2178 | * back cache block contents later for performance reasons, | |
2179 | * so they may differ from the corresponding origin blocks. | |
2180 | */ | |
2181 | struct cache_args { | |
2182 | struct dm_target *ti; | |
2183 | ||
2184 | struct dm_dev *metadata_dev; | |
2185 | ||
2186 | struct dm_dev *cache_dev; | |
2187 | sector_t cache_sectors; | |
2188 | ||
2189 | struct dm_dev *origin_dev; | |
2190 | sector_t origin_sectors; | |
2191 | ||
2192 | uint32_t block_size; | |
2193 | ||
2194 | const char *policy_name; | |
2195 | int policy_argc; | |
2196 | const char **policy_argv; | |
2197 | ||
2198 | struct cache_features features; | |
2199 | }; | |
2200 | ||
2201 | static void destroy_cache_args(struct cache_args *ca) | |
2202 | { | |
2203 | if (ca->metadata_dev) | |
2204 | dm_put_device(ca->ti, ca->metadata_dev); | |
2205 | ||
2206 | if (ca->cache_dev) | |
2207 | dm_put_device(ca->ti, ca->cache_dev); | |
2208 | ||
2209 | if (ca->origin_dev) | |
2210 | dm_put_device(ca->ti, ca->origin_dev); | |
2211 | ||
2212 | kfree(ca); | |
2213 | } | |
2214 | ||
2215 | static bool at_least_one_arg(struct dm_arg_set *as, char **error) | |
2216 | { | |
2217 | if (!as->argc) { | |
2218 | *error = "Insufficient args"; | |
2219 | return false; | |
2220 | } | |
2221 | ||
2222 | return true; | |
2223 | } | |
2224 | ||
2225 | static int parse_metadata_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2226 | char **error) | |
2227 | { | |
2228 | int r; | |
2229 | sector_t metadata_dev_size; | |
2230 | char b[BDEVNAME_SIZE]; | |
2231 | ||
2232 | if (!at_least_one_arg(as, error)) | |
2233 | return -EINVAL; | |
2234 | ||
2235 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2236 | &ca->metadata_dev); | |
2237 | if (r) { | |
2238 | *error = "Error opening metadata device"; | |
2239 | return r; | |
2240 | } | |
2241 | ||
2242 | metadata_dev_size = get_dev_size(ca->metadata_dev); | |
2243 | if (metadata_dev_size > DM_CACHE_METADATA_MAX_SECTORS_WARNING) | |
2244 | DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.", | |
2245 | bdevname(ca->metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS); | |
2246 | ||
2247 | return 0; | |
2248 | } | |
2249 | ||
2250 | static int parse_cache_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2251 | char **error) | |
2252 | { | |
2253 | int r; | |
2254 | ||
2255 | if (!at_least_one_arg(as, error)) | |
2256 | return -EINVAL; | |
2257 | ||
2258 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2259 | &ca->cache_dev); | |
2260 | if (r) { | |
2261 | *error = "Error opening cache device"; | |
2262 | return r; | |
2263 | } | |
2264 | ca->cache_sectors = get_dev_size(ca->cache_dev); | |
2265 | ||
2266 | return 0; | |
2267 | } | |
2268 | ||
2269 | static int parse_origin_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2270 | char **error) | |
2271 | { | |
2272 | int r; | |
2273 | ||
2274 | if (!at_least_one_arg(as, error)) | |
2275 | return -EINVAL; | |
2276 | ||
2277 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2278 | &ca->origin_dev); | |
2279 | if (r) { | |
2280 | *error = "Error opening origin device"; | |
2281 | return r; | |
2282 | } | |
2283 | ||
2284 | ca->origin_sectors = get_dev_size(ca->origin_dev); | |
2285 | if (ca->ti->len > ca->origin_sectors) { | |
2286 | *error = "Device size larger than cached device"; | |
2287 | return -EINVAL; | |
2288 | } | |
2289 | ||
2290 | return 0; | |
2291 | } | |
2292 | ||
2293 | static int parse_block_size(struct cache_args *ca, struct dm_arg_set *as, | |
2294 | char **error) | |
2295 | { | |
05473044 | 2296 | unsigned long block_size; |
c6b4fcba JT |
2297 | |
2298 | if (!at_least_one_arg(as, error)) | |
2299 | return -EINVAL; | |
2300 | ||
05473044 MS |
2301 | if (kstrtoul(dm_shift_arg(as), 10, &block_size) || !block_size || |
2302 | block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS || | |
2303 | block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS || | |
2304 | block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) { | |
c6b4fcba JT |
2305 | *error = "Invalid data block size"; |
2306 | return -EINVAL; | |
2307 | } | |
2308 | ||
05473044 | 2309 | if (block_size > ca->cache_sectors) { |
c6b4fcba JT |
2310 | *error = "Data block size is larger than the cache device"; |
2311 | return -EINVAL; | |
2312 | } | |
2313 | ||
05473044 | 2314 | ca->block_size = block_size; |
c6b4fcba JT |
2315 | |
2316 | return 0; | |
2317 | } | |
2318 | ||
2319 | static void init_features(struct cache_features *cf) | |
2320 | { | |
2321 | cf->mode = CM_WRITE; | |
2ee57d58 | 2322 | cf->io_mode = CM_IO_WRITEBACK; |
629d0a8a | 2323 | cf->metadata_version = 1; |
c6b4fcba JT |
2324 | } |
2325 | ||
2326 | static int parse_features(struct cache_args *ca, struct dm_arg_set *as, | |
2327 | char **error) | |
2328 | { | |
5916a22b | 2329 | static const struct dm_arg _args[] = { |
629d0a8a | 2330 | {0, 2, "Invalid number of cache feature arguments"}, |
c6b4fcba JT |
2331 | }; |
2332 | ||
e85940a5 | 2333 | int r, mode_ctr = 0; |
c6b4fcba JT |
2334 | unsigned argc; |
2335 | const char *arg; | |
2336 | struct cache_features *cf = &ca->features; | |
2337 | ||
2338 | init_features(cf); | |
2339 | ||
2340 | r = dm_read_arg_group(_args, as, &argc, error); | |
2341 | if (r) | |
2342 | return -EINVAL; | |
2343 | ||
2344 | while (argc--) { | |
2345 | arg = dm_shift_arg(as); | |
2346 | ||
e85940a5 | 2347 | if (!strcasecmp(arg, "writeback")) { |
2ee57d58 | 2348 | cf->io_mode = CM_IO_WRITEBACK; |
e85940a5 JP |
2349 | mode_ctr++; |
2350 | } | |
c6b4fcba | 2351 | |
e85940a5 | 2352 | else if (!strcasecmp(arg, "writethrough")) { |
2ee57d58 | 2353 | cf->io_mode = CM_IO_WRITETHROUGH; |
e85940a5 JP |
2354 | mode_ctr++; |
2355 | } | |
2ee57d58 | 2356 | |
e85940a5 | 2357 | else if (!strcasecmp(arg, "passthrough")) { |
2ee57d58 | 2358 | cf->io_mode = CM_IO_PASSTHROUGH; |
e85940a5 JP |
2359 | mode_ctr++; |
2360 | } | |
c6b4fcba | 2361 | |
629d0a8a JT |
2362 | else if (!strcasecmp(arg, "metadata2")) |
2363 | cf->metadata_version = 2; | |
2364 | ||
c6b4fcba JT |
2365 | else { |
2366 | *error = "Unrecognised cache feature requested"; | |
2367 | return -EINVAL; | |
2368 | } | |
2369 | } | |
2370 | ||
e85940a5 JP |
2371 | if (mode_ctr > 1) { |
2372 | *error = "Duplicate cache io_mode features requested"; | |
2373 | return -EINVAL; | |
2374 | } | |
2375 | ||
c6b4fcba JT |
2376 | return 0; |
2377 | } | |
2378 | ||
2379 | static int parse_policy(struct cache_args *ca, struct dm_arg_set *as, | |
2380 | char **error) | |
2381 | { | |
5916a22b | 2382 | static const struct dm_arg _args[] = { |
c6b4fcba JT |
2383 | {0, 1024, "Invalid number of policy arguments"}, |
2384 | }; | |
2385 | ||
2386 | int r; | |
2387 | ||
2388 | if (!at_least_one_arg(as, error)) | |
2389 | return -EINVAL; | |
2390 | ||
2391 | ca->policy_name = dm_shift_arg(as); | |
2392 | ||
2393 | r = dm_read_arg_group(_args, as, &ca->policy_argc, error); | |
2394 | if (r) | |
2395 | return -EINVAL; | |
2396 | ||
2397 | ca->policy_argv = (const char **)as->argv; | |
2398 | dm_consume_args(as, ca->policy_argc); | |
2399 | ||
2400 | return 0; | |
2401 | } | |
2402 | ||
2403 | static int parse_cache_args(struct cache_args *ca, int argc, char **argv, | |
2404 | char **error) | |
2405 | { | |
2406 | int r; | |
2407 | struct dm_arg_set as; | |
2408 | ||
2409 | as.argc = argc; | |
2410 | as.argv = argv; | |
2411 | ||
2412 | r = parse_metadata_dev(ca, &as, error); | |
2413 | if (r) | |
2414 | return r; | |
2415 | ||
2416 | r = parse_cache_dev(ca, &as, error); | |
2417 | if (r) | |
2418 | return r; | |
2419 | ||
2420 | r = parse_origin_dev(ca, &as, error); | |
2421 | if (r) | |
2422 | return r; | |
2423 | ||
2424 | r = parse_block_size(ca, &as, error); | |
2425 | if (r) | |
2426 | return r; | |
2427 | ||
2428 | r = parse_features(ca, &as, error); | |
2429 | if (r) | |
2430 | return r; | |
2431 | ||
2432 | r = parse_policy(ca, &as, error); | |
2433 | if (r) | |
2434 | return r; | |
2435 | ||
2436 | return 0; | |
2437 | } | |
2438 | ||
2439 | /*----------------------------------------------------------------*/ | |
2440 | ||
2441 | static struct kmem_cache *migration_cache; | |
2442 | ||
2c73c471 AK |
2443 | #define NOT_CORE_OPTION 1 |
2444 | ||
2f14f4b5 | 2445 | static int process_config_option(struct cache *cache, const char *key, const char *value) |
2c73c471 AK |
2446 | { |
2447 | unsigned long tmp; | |
2448 | ||
2f14f4b5 JT |
2449 | if (!strcasecmp(key, "migration_threshold")) { |
2450 | if (kstrtoul(value, 10, &tmp)) | |
2c73c471 AK |
2451 | return -EINVAL; |
2452 | ||
2453 | cache->migration_threshold = tmp; | |
2454 | return 0; | |
2455 | } | |
2456 | ||
2457 | return NOT_CORE_OPTION; | |
2458 | } | |
2459 | ||
2f14f4b5 JT |
2460 | static int set_config_value(struct cache *cache, const char *key, const char *value) |
2461 | { | |
2462 | int r = process_config_option(cache, key, value); | |
2463 | ||
2464 | if (r == NOT_CORE_OPTION) | |
2465 | r = policy_set_config_value(cache->policy, key, value); | |
2466 | ||
2467 | if (r) | |
2468 | DMWARN("bad config value for %s: %s", key, value); | |
2469 | ||
2470 | return r; | |
2471 | } | |
2472 | ||
2473 | static int set_config_values(struct cache *cache, int argc, const char **argv) | |
c6b4fcba JT |
2474 | { |
2475 | int r = 0; | |
2476 | ||
2477 | if (argc & 1) { | |
2478 | DMWARN("Odd number of policy arguments given but they should be <key> <value> pairs."); | |
2479 | return -EINVAL; | |
2480 | } | |
2481 | ||
2482 | while (argc) { | |
2f14f4b5 JT |
2483 | r = set_config_value(cache, argv[0], argv[1]); |
2484 | if (r) | |
2485 | break; | |
c6b4fcba JT |
2486 | |
2487 | argc -= 2; | |
2488 | argv += 2; | |
2489 | } | |
2490 | ||
2491 | return r; | |
2492 | } | |
2493 | ||
2494 | static int create_cache_policy(struct cache *cache, struct cache_args *ca, | |
2495 | char **error) | |
2496 | { | |
4cb3e1db MP |
2497 | struct dm_cache_policy *p = dm_cache_policy_create(ca->policy_name, |
2498 | cache->cache_size, | |
2499 | cache->origin_sectors, | |
2500 | cache->sectors_per_block); | |
2501 | if (IS_ERR(p)) { | |
c6b4fcba | 2502 | *error = "Error creating cache's policy"; |
4cb3e1db | 2503 | return PTR_ERR(p); |
c6b4fcba | 2504 | } |
4cb3e1db | 2505 | cache->policy = p; |
b29d4986 | 2506 | BUG_ON(!cache->policy); |
c6b4fcba | 2507 | |
2f14f4b5 | 2508 | return 0; |
c6b4fcba JT |
2509 | } |
2510 | ||
08b18451 | 2511 | /* |
2bb812df JT |
2512 | * We want the discard block size to be at least the size of the cache |
2513 | * block size and have no more than 2^14 discard blocks across the origin. | |
08b18451 JT |
2514 | */ |
2515 | #define MAX_DISCARD_BLOCKS (1 << 14) | |
2516 | ||
2517 | static bool too_many_discard_blocks(sector_t discard_block_size, | |
2518 | sector_t origin_size) | |
2519 | { | |
2520 | (void) sector_div(origin_size, discard_block_size); | |
2521 | ||
2522 | return origin_size > MAX_DISCARD_BLOCKS; | |
2523 | } | |
2524 | ||
2525 | static sector_t calculate_discard_block_size(sector_t cache_block_size, | |
2526 | sector_t origin_size) | |
2527 | { | |
2bb812df | 2528 | sector_t discard_block_size = cache_block_size; |
08b18451 JT |
2529 | |
2530 | if (origin_size) | |
2531 | while (too_many_discard_blocks(discard_block_size, origin_size)) | |
2532 | discard_block_size *= 2; | |
2533 | ||
2534 | return discard_block_size; | |
2535 | } | |
2536 | ||
d1d9220c JT |
2537 | static void set_cache_size(struct cache *cache, dm_cblock_t size) |
2538 | { | |
2539 | dm_block_t nr_blocks = from_cblock(size); | |
2540 | ||
2541 | if (nr_blocks > (1 << 20) && cache->cache_size != size) | |
2542 | DMWARN_LIMIT("You have created a cache device with a lot of individual cache blocks (%llu)\n" | |
2543 | "All these mappings can consume a lot of kernel memory, and take some time to read/write.\n" | |
2544 | "Please consider increasing the cache block size to reduce the overall cache block count.", | |
2545 | (unsigned long long) nr_blocks); | |
2546 | ||
2547 | cache->cache_size = size; | |
2548 | } | |
2549 | ||
b29d4986 JT |
2550 | static int is_congested(struct dm_dev *dev, int bdi_bits) |
2551 | { | |
2552 | struct request_queue *q = bdev_get_queue(dev->bdev); | |
2553 | return bdi_congested(q->backing_dev_info, bdi_bits); | |
2554 | } | |
2555 | ||
2556 | static int cache_is_congested(struct dm_target_callbacks *cb, int bdi_bits) | |
2557 | { | |
2558 | struct cache *cache = container_of(cb, struct cache, callbacks); | |
2559 | ||
2560 | return is_congested(cache->origin_dev, bdi_bits) || | |
2561 | is_congested(cache->cache_dev, bdi_bits); | |
2562 | } | |
2563 | ||
f8350daf | 2564 | #define DEFAULT_MIGRATION_THRESHOLD 2048 |
c6b4fcba | 2565 | |
c6b4fcba JT |
2566 | static int cache_create(struct cache_args *ca, struct cache **result) |
2567 | { | |
2568 | int r = 0; | |
2569 | char **error = &ca->ti->error; | |
2570 | struct cache *cache; | |
2571 | struct dm_target *ti = ca->ti; | |
2572 | dm_block_t origin_blocks; | |
2573 | struct dm_cache_metadata *cmd; | |
2574 | bool may_format = ca->features.mode == CM_WRITE; | |
2575 | ||
2576 | cache = kzalloc(sizeof(*cache), GFP_KERNEL); | |
2577 | if (!cache) | |
2578 | return -ENOMEM; | |
2579 | ||
2580 | cache->ti = ca->ti; | |
2581 | ti->private = cache; | |
c6b4fcba JT |
2582 | ti->num_flush_bios = 2; |
2583 | ti->flush_supported = true; | |
2584 | ||
2585 | ti->num_discard_bios = 1; | |
2586 | ti->discards_supported = true; | |
2572629a | 2587 | ti->split_discard_bios = false; |
c6b4fcba | 2588 | |
8c5008fa | 2589 | cache->features = ca->features; |
30187e1d | 2590 | ti->per_io_data_size = get_per_bio_data_size(cache); |
c6b4fcba | 2591 | |
c6b4fcba JT |
2592 | cache->callbacks.congested_fn = cache_is_congested; |
2593 | dm_table_add_target_callbacks(ti->table, &cache->callbacks); | |
2594 | ||
2595 | cache->metadata_dev = ca->metadata_dev; | |
2596 | cache->origin_dev = ca->origin_dev; | |
2597 | cache->cache_dev = ca->cache_dev; | |
2598 | ||
2599 | ca->metadata_dev = ca->origin_dev = ca->cache_dev = NULL; | |
2600 | ||
c6b4fcba | 2601 | origin_blocks = cache->origin_sectors = ca->origin_sectors; |
414dd67d | 2602 | origin_blocks = block_div(origin_blocks, ca->block_size); |
c6b4fcba JT |
2603 | cache->origin_blocks = to_oblock(origin_blocks); |
2604 | ||
2605 | cache->sectors_per_block = ca->block_size; | |
2606 | if (dm_set_target_max_io_len(ti, cache->sectors_per_block)) { | |
2607 | r = -EINVAL; | |
2608 | goto bad; | |
2609 | } | |
2610 | ||
2611 | if (ca->block_size & (ca->block_size - 1)) { | |
2612 | dm_block_t cache_size = ca->cache_sectors; | |
2613 | ||
2614 | cache->sectors_per_block_shift = -1; | |
414dd67d | 2615 | cache_size = block_div(cache_size, ca->block_size); |
d1d9220c | 2616 | set_cache_size(cache, to_cblock(cache_size)); |
c6b4fcba JT |
2617 | } else { |
2618 | cache->sectors_per_block_shift = __ffs(ca->block_size); | |
d1d9220c | 2619 | set_cache_size(cache, to_cblock(ca->cache_sectors >> cache->sectors_per_block_shift)); |
c6b4fcba JT |
2620 | } |
2621 | ||
2622 | r = create_cache_policy(cache, ca, error); | |
2623 | if (r) | |
2624 | goto bad; | |
2f14f4b5 | 2625 | |
c6b4fcba | 2626 | cache->policy_nr_args = ca->policy_argc; |
2f14f4b5 JT |
2627 | cache->migration_threshold = DEFAULT_MIGRATION_THRESHOLD; |
2628 | ||
2629 | r = set_config_values(cache, ca->policy_argc, ca->policy_argv); | |
2630 | if (r) { | |
2631 | *error = "Error setting cache policy's config values"; | |
2632 | goto bad; | |
2633 | } | |
c6b4fcba JT |
2634 | |
2635 | cmd = dm_cache_metadata_open(cache->metadata_dev->bdev, | |
2636 | ca->block_size, may_format, | |
629d0a8a JT |
2637 | dm_cache_policy_get_hint_size(cache->policy), |
2638 | ca->features.metadata_version); | |
c6b4fcba JT |
2639 | if (IS_ERR(cmd)) { |
2640 | *error = "Error creating metadata object"; | |
2641 | r = PTR_ERR(cmd); | |
2642 | goto bad; | |
2643 | } | |
2644 | cache->cmd = cmd; | |
028ae9f7 JT |
2645 | set_cache_mode(cache, CM_WRITE); |
2646 | if (get_cache_mode(cache) != CM_WRITE) { | |
2647 | *error = "Unable to get write access to metadata, please check/repair metadata."; | |
2648 | r = -EINVAL; | |
2649 | goto bad; | |
2650 | } | |
c6b4fcba | 2651 | |
2ee57d58 JT |
2652 | if (passthrough_mode(&cache->features)) { |
2653 | bool all_clean; | |
2654 | ||
2655 | r = dm_cache_metadata_all_clean(cache->cmd, &all_clean); | |
2656 | if (r) { | |
2657 | *error = "dm_cache_metadata_all_clean() failed"; | |
2658 | goto bad; | |
2659 | } | |
2660 | ||
2661 | if (!all_clean) { | |
2662 | *error = "Cannot enter passthrough mode unless all blocks are clean"; | |
2663 | r = -EINVAL; | |
2664 | goto bad; | |
2665 | } | |
b29d4986 JT |
2666 | |
2667 | policy_allow_migrations(cache->policy, false); | |
2ee57d58 JT |
2668 | } |
2669 | ||
c6b4fcba | 2670 | spin_lock_init(&cache->lock); |
651f5fa2 | 2671 | INIT_LIST_HEAD(&cache->deferred_cells); |
c6b4fcba | 2672 | bio_list_init(&cache->deferred_bios); |
e2e74d61 | 2673 | bio_list_init(&cache->deferred_writethrough_bios); |
a59db676 JT |
2674 | atomic_set(&cache->nr_allocated_migrations, 0); |
2675 | atomic_set(&cache->nr_io_migrations, 0); | |
c6b4fcba JT |
2676 | init_waitqueue_head(&cache->migration_wait); |
2677 | ||
fa4d683a | 2678 | r = -ENOMEM; |
44fa816b | 2679 | atomic_set(&cache->nr_dirty, 0); |
c6b4fcba JT |
2680 | cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size)); |
2681 | if (!cache->dirty_bitset) { | |
2682 | *error = "could not allocate dirty bitset"; | |
2683 | goto bad; | |
2684 | } | |
2685 | clear_bitset(cache->dirty_bitset, from_cblock(cache->cache_size)); | |
2686 | ||
08b18451 JT |
2687 | cache->discard_block_size = |
2688 | calculate_discard_block_size(cache->sectors_per_block, | |
2689 | cache->origin_sectors); | |
2572629a JT |
2690 | cache->discard_nr_blocks = to_dblock(dm_sector_div_up(cache->origin_sectors, |
2691 | cache->discard_block_size)); | |
1bad9bc4 | 2692 | cache->discard_bitset = alloc_bitset(from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2693 | if (!cache->discard_bitset) { |
2694 | *error = "could not allocate discard bitset"; | |
2695 | goto bad; | |
2696 | } | |
1bad9bc4 | 2697 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2698 | |
2699 | cache->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle); | |
2700 | if (IS_ERR(cache->copier)) { | |
2701 | *error = "could not create kcopyd client"; | |
2702 | r = PTR_ERR(cache->copier); | |
2703 | goto bad; | |
2704 | } | |
2705 | ||
b29d4986 | 2706 | cache->wq = alloc_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM, 0); |
c6b4fcba JT |
2707 | if (!cache->wq) { |
2708 | *error = "could not create workqueue for metadata object"; | |
2709 | goto bad; | |
2710 | } | |
b29d4986 JT |
2711 | INIT_WORK(&cache->deferred_bio_worker, process_deferred_bios); |
2712 | INIT_WORK(&cache->deferred_writethrough_worker, | |
2713 | process_deferred_writethrough_bios); | |
2714 | INIT_WORK(&cache->migration_worker, check_migrations); | |
c6b4fcba | 2715 | INIT_DELAYED_WORK(&cache->waker, do_waker); |
c6b4fcba | 2716 | |
b29d4986 | 2717 | cache->prison = dm_bio_prison_create_v2(cache->wq); |
c6b4fcba JT |
2718 | if (!cache->prison) { |
2719 | *error = "could not create bio prison"; | |
2720 | goto bad; | |
2721 | } | |
2722 | ||
c6b4fcba JT |
2723 | cache->migration_pool = mempool_create_slab_pool(MIGRATION_POOL_SIZE, |
2724 | migration_cache); | |
2725 | if (!cache->migration_pool) { | |
2726 | *error = "Error creating cache's migration mempool"; | |
2727 | goto bad; | |
2728 | } | |
2729 | ||
c6b4fcba JT |
2730 | cache->need_tick_bio = true; |
2731 | cache->sized = false; | |
65790ff9 | 2732 | cache->invalidate = false; |
c6b4fcba JT |
2733 | cache->commit_requested = false; |
2734 | cache->loaded_mappings = false; | |
2735 | cache->loaded_discards = false; | |
2736 | ||
2737 | load_stats(cache); | |
2738 | ||
2739 | atomic_set(&cache->stats.demotion, 0); | |
2740 | atomic_set(&cache->stats.promotion, 0); | |
2741 | atomic_set(&cache->stats.copies_avoided, 0); | |
2742 | atomic_set(&cache->stats.cache_cell_clash, 0); | |
2743 | atomic_set(&cache->stats.commit_count, 0); | |
2744 | atomic_set(&cache->stats.discard_count, 0); | |
2745 | ||
65790ff9 JT |
2746 | spin_lock_init(&cache->invalidation_lock); |
2747 | INIT_LIST_HEAD(&cache->invalidation_requests); | |
2748 | ||
b29d4986 JT |
2749 | batcher_init(&cache->committer, commit_op, cache, |
2750 | issue_op, cache, cache->wq); | |
701e03e4 | 2751 | iot_init(&cache->tracker); |
066dbaa3 | 2752 | |
b29d4986 JT |
2753 | init_rwsem(&cache->background_work_lock); |
2754 | prevent_background_work(cache); | |
2755 | ||
c6b4fcba JT |
2756 | *result = cache; |
2757 | return 0; | |
c6b4fcba JT |
2758 | bad: |
2759 | destroy(cache); | |
2760 | return r; | |
2761 | } | |
2762 | ||
2763 | static int copy_ctr_args(struct cache *cache, int argc, const char **argv) | |
2764 | { | |
2765 | unsigned i; | |
2766 | const char **copy; | |
2767 | ||
2768 | copy = kcalloc(argc, sizeof(*copy), GFP_KERNEL); | |
2769 | if (!copy) | |
2770 | return -ENOMEM; | |
2771 | for (i = 0; i < argc; i++) { | |
2772 | copy[i] = kstrdup(argv[i], GFP_KERNEL); | |
2773 | if (!copy[i]) { | |
2774 | while (i--) | |
2775 | kfree(copy[i]); | |
2776 | kfree(copy); | |
2777 | return -ENOMEM; | |
2778 | } | |
2779 | } | |
2780 | ||
2781 | cache->nr_ctr_args = argc; | |
2782 | cache->ctr_args = copy; | |
2783 | ||
2784 | return 0; | |
2785 | } | |
2786 | ||
2787 | static int cache_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
2788 | { | |
2789 | int r = -EINVAL; | |
2790 | struct cache_args *ca; | |
2791 | struct cache *cache = NULL; | |
2792 | ||
2793 | ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
2794 | if (!ca) { | |
2795 | ti->error = "Error allocating memory for cache"; | |
2796 | return -ENOMEM; | |
2797 | } | |
2798 | ca->ti = ti; | |
2799 | ||
2800 | r = parse_cache_args(ca, argc, argv, &ti->error); | |
2801 | if (r) | |
2802 | goto out; | |
2803 | ||
2804 | r = cache_create(ca, &cache); | |
617a0b89 HM |
2805 | if (r) |
2806 | goto out; | |
c6b4fcba JT |
2807 | |
2808 | r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3); | |
2809 | if (r) { | |
2810 | destroy(cache); | |
2811 | goto out; | |
2812 | } | |
2813 | ||
2814 | ti->private = cache; | |
c6b4fcba JT |
2815 | out: |
2816 | destroy_cache_args(ca); | |
2817 | return r; | |
2818 | } | |
2819 | ||
651f5fa2 JT |
2820 | /*----------------------------------------------------------------*/ |
2821 | ||
2822 | static int cache_map(struct dm_target *ti, struct bio *bio) | |
c6b4fcba | 2823 | { |
651f5fa2 JT |
2824 | struct cache *cache = ti->private; |
2825 | ||
c6b4fcba | 2826 | int r; |
b29d4986 | 2827 | bool commit_needed; |
c6b4fcba | 2828 | dm_oblock_t block = get_bio_block(cache, bio); |
19b0092e | 2829 | size_t pb_data_size = get_per_bio_data_size(cache); |
c6b4fcba | 2830 | |
b29d4986 | 2831 | init_per_bio_data(bio, pb_data_size); |
e893fba9 | 2832 | if (unlikely(from_oblock(block) >= from_oblock(cache->origin_blocks))) { |
c6b4fcba JT |
2833 | /* |
2834 | * This can only occur if the io goes to a partial block at | |
2835 | * the end of the origin device. We don't cache these. | |
2836 | * Just remap to the origin and carry on. | |
2837 | */ | |
e893fba9 | 2838 | remap_to_origin(cache, bio); |
651f5fa2 | 2839 | accounted_begin(cache, bio); |
c6b4fcba JT |
2840 | return DM_MAPIO_REMAPPED; |
2841 | } | |
2842 | ||
651f5fa2 | 2843 | if (discard_or_flush(bio)) { |
c6b4fcba JT |
2844 | defer_bio(cache, bio); |
2845 | return DM_MAPIO_SUBMITTED; | |
2846 | } | |
2847 | ||
b29d4986 JT |
2848 | r = map_bio(cache, bio, block, &commit_needed); |
2849 | if (commit_needed) | |
2850 | schedule_commit(&cache->committer); | |
c6b4fcba | 2851 | |
2ee57d58 | 2852 | return r; |
c6b4fcba JT |
2853 | } |
2854 | ||
4e4cbee9 CH |
2855 | static int cache_end_io(struct dm_target *ti, struct bio *bio, |
2856 | blk_status_t *error) | |
c6b4fcba JT |
2857 | { |
2858 | struct cache *cache = ti->private; | |
2859 | unsigned long flags; | |
19b0092e MS |
2860 | size_t pb_data_size = get_per_bio_data_size(cache); |
2861 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
c6b4fcba JT |
2862 | |
2863 | if (pb->tick) { | |
fba10109 | 2864 | policy_tick(cache->policy, false); |
c6b4fcba JT |
2865 | |
2866 | spin_lock_irqsave(&cache->lock, flags); | |
2867 | cache->need_tick_bio = true; | |
2868 | spin_unlock_irqrestore(&cache->lock, flags); | |
2869 | } | |
2870 | ||
b29d4986 | 2871 | bio_drop_shared_lock(cache, bio); |
066dbaa3 | 2872 | accounted_complete(cache, bio); |
c6b4fcba | 2873 | |
1be56909 | 2874 | return DM_ENDIO_DONE; |
c6b4fcba JT |
2875 | } |
2876 | ||
2877 | static int write_dirty_bitset(struct cache *cache) | |
2878 | { | |
629d0a8a | 2879 | int r; |
c6b4fcba | 2880 | |
028ae9f7 JT |
2881 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
2882 | return -EINVAL; | |
2883 | ||
629d0a8a JT |
2884 | r = dm_cache_set_dirty_bits(cache->cmd, from_cblock(cache->cache_size), cache->dirty_bitset); |
2885 | if (r) | |
2886 | metadata_operation_failed(cache, "dm_cache_set_dirty_bits", r); | |
c6b4fcba | 2887 | |
629d0a8a | 2888 | return r; |
c6b4fcba JT |
2889 | } |
2890 | ||
2891 | static int write_discard_bitset(struct cache *cache) | |
2892 | { | |
2893 | unsigned i, r; | |
2894 | ||
028ae9f7 JT |
2895 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
2896 | return -EINVAL; | |
2897 | ||
1bad9bc4 JT |
2898 | r = dm_cache_discard_bitset_resize(cache->cmd, cache->discard_block_size, |
2899 | cache->discard_nr_blocks); | |
c6b4fcba | 2900 | if (r) { |
b61d9509 | 2901 | DMERR("%s: could not resize on-disk discard bitset", cache_device_name(cache)); |
028ae9f7 | 2902 | metadata_operation_failed(cache, "dm_cache_discard_bitset_resize", r); |
c6b4fcba JT |
2903 | return r; |
2904 | } | |
2905 | ||
1bad9bc4 JT |
2906 | for (i = 0; i < from_dblock(cache->discard_nr_blocks); i++) { |
2907 | r = dm_cache_set_discard(cache->cmd, to_dblock(i), | |
2908 | is_discarded(cache, to_dblock(i))); | |
028ae9f7 JT |
2909 | if (r) { |
2910 | metadata_operation_failed(cache, "dm_cache_set_discard", r); | |
c6b4fcba | 2911 | return r; |
028ae9f7 JT |
2912 | } |
2913 | } | |
2914 | ||
2915 | return 0; | |
2916 | } | |
2917 | ||
2918 | static int write_hints(struct cache *cache) | |
2919 | { | |
2920 | int r; | |
2921 | ||
2922 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
2923 | return -EINVAL; | |
2924 | ||
2925 | r = dm_cache_write_hints(cache->cmd, cache->policy); | |
2926 | if (r) { | |
2927 | metadata_operation_failed(cache, "dm_cache_write_hints", r); | |
2928 | return r; | |
c6b4fcba JT |
2929 | } |
2930 | ||
2931 | return 0; | |
2932 | } | |
2933 | ||
c6b4fcba JT |
2934 | /* |
2935 | * returns true on success | |
2936 | */ | |
2937 | static bool sync_metadata(struct cache *cache) | |
2938 | { | |
2939 | int r1, r2, r3, r4; | |
2940 | ||
2941 | r1 = write_dirty_bitset(cache); | |
2942 | if (r1) | |
b61d9509 | 2943 | DMERR("%s: could not write dirty bitset", cache_device_name(cache)); |
c6b4fcba JT |
2944 | |
2945 | r2 = write_discard_bitset(cache); | |
2946 | if (r2) | |
b61d9509 | 2947 | DMERR("%s: could not write discard bitset", cache_device_name(cache)); |
c6b4fcba JT |
2948 | |
2949 | save_stats(cache); | |
2950 | ||
028ae9f7 | 2951 | r3 = write_hints(cache); |
c6b4fcba | 2952 | if (r3) |
b61d9509 | 2953 | DMERR("%s: could not write hints", cache_device_name(cache)); |
c6b4fcba JT |
2954 | |
2955 | /* | |
2956 | * If writing the above metadata failed, we still commit, but don't | |
2957 | * set the clean shutdown flag. This will effectively force every | |
2958 | * dirty bit to be set on reload. | |
2959 | */ | |
028ae9f7 | 2960 | r4 = commit(cache, !r1 && !r2 && !r3); |
c6b4fcba | 2961 | if (r4) |
b61d9509 | 2962 | DMERR("%s: could not write cache metadata", cache_device_name(cache)); |
c6b4fcba JT |
2963 | |
2964 | return !r1 && !r2 && !r3 && !r4; | |
2965 | } | |
2966 | ||
2967 | static void cache_postsuspend(struct dm_target *ti) | |
2968 | { | |
2969 | struct cache *cache = ti->private; | |
2970 | ||
b29d4986 JT |
2971 | prevent_background_work(cache); |
2972 | BUG_ON(atomic_read(&cache->nr_io_migrations)); | |
2973 | ||
2974 | cancel_delayed_work(&cache->waker); | |
2975 | flush_workqueue(cache->wq); | |
701e03e4 | 2976 | WARN_ON(cache->tracker.in_flight); |
b29d4986 JT |
2977 | |
2978 | /* | |
2979 | * If it's a flush suspend there won't be any deferred bios, so this | |
2980 | * call is harmless. | |
2981 | */ | |
651f5fa2 | 2982 | requeue_deferred_bios(cache); |
c6b4fcba | 2983 | |
028ae9f7 JT |
2984 | if (get_cache_mode(cache) == CM_WRITE) |
2985 | (void) sync_metadata(cache); | |
c6b4fcba JT |
2986 | } |
2987 | ||
2988 | static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock, | |
2989 | bool dirty, uint32_t hint, bool hint_valid) | |
2990 | { | |
2991 | int r; | |
2992 | struct cache *cache = context; | |
2993 | ||
449b668c JT |
2994 | if (dirty) { |
2995 | set_bit(from_cblock(cblock), cache->dirty_bitset); | |
2996 | atomic_inc(&cache->nr_dirty); | |
2997 | } else | |
2998 | clear_bit(from_cblock(cblock), cache->dirty_bitset); | |
2999 | ||
b29d4986 | 3000 | r = policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid); |
c6b4fcba JT |
3001 | if (r) |
3002 | return r; | |
3003 | ||
c6b4fcba JT |
3004 | return 0; |
3005 | } | |
3006 | ||
3e2e1c30 JT |
3007 | /* |
3008 | * The discard block size in the on disk metadata is not | |
3009 | * neccessarily the same as we're currently using. So we have to | |
3010 | * be careful to only set the discarded attribute if we know it | |
3011 | * covers a complete block of the new size. | |
3012 | */ | |
3013 | struct discard_load_info { | |
3014 | struct cache *cache; | |
3015 | ||
3016 | /* | |
3017 | * These blocks are sized using the on disk dblock size, rather | |
3018 | * than the current one. | |
3019 | */ | |
3020 | dm_block_t block_size; | |
3021 | dm_block_t discard_begin, discard_end; | |
3022 | }; | |
3023 | ||
3024 | static void discard_load_info_init(struct cache *cache, | |
3025 | struct discard_load_info *li) | |
3026 | { | |
3027 | li->cache = cache; | |
3028 | li->discard_begin = li->discard_end = 0; | |
3029 | } | |
3030 | ||
3031 | static void set_discard_range(struct discard_load_info *li) | |
3032 | { | |
3033 | sector_t b, e; | |
3034 | ||
3035 | if (li->discard_begin == li->discard_end) | |
3036 | return; | |
3037 | ||
3038 | /* | |
3039 | * Convert to sectors. | |
3040 | */ | |
3041 | b = li->discard_begin * li->block_size; | |
3042 | e = li->discard_end * li->block_size; | |
3043 | ||
3044 | /* | |
3045 | * Then convert back to the current dblock size. | |
3046 | */ | |
3047 | b = dm_sector_div_up(b, li->cache->discard_block_size); | |
3048 | sector_div(e, li->cache->discard_block_size); | |
3049 | ||
3050 | /* | |
3051 | * The origin may have shrunk, so we need to check we're still in | |
3052 | * bounds. | |
3053 | */ | |
3054 | if (e > from_dblock(li->cache->discard_nr_blocks)) | |
3055 | e = from_dblock(li->cache->discard_nr_blocks); | |
3056 | ||
3057 | for (; b < e; b++) | |
3058 | set_discard(li->cache, to_dblock(b)); | |
3059 | } | |
3060 | ||
c6b4fcba | 3061 | static int load_discard(void *context, sector_t discard_block_size, |
1bad9bc4 | 3062 | dm_dblock_t dblock, bool discard) |
c6b4fcba | 3063 | { |
3e2e1c30 | 3064 | struct discard_load_info *li = context; |
c6b4fcba | 3065 | |
3e2e1c30 | 3066 | li->block_size = discard_block_size; |
1bad9bc4 | 3067 | |
3e2e1c30 JT |
3068 | if (discard) { |
3069 | if (from_dblock(dblock) == li->discard_end) | |
3070 | /* | |
3071 | * We're already in a discard range, just extend it. | |
3072 | */ | |
3073 | li->discard_end = li->discard_end + 1ULL; | |
3074 | ||
3075 | else { | |
3076 | /* | |
3077 | * Emit the old range and start a new one. | |
3078 | */ | |
3079 | set_discard_range(li); | |
3080 | li->discard_begin = from_dblock(dblock); | |
3081 | li->discard_end = li->discard_begin + 1ULL; | |
3082 | } | |
3083 | } else { | |
3084 | set_discard_range(li); | |
3085 | li->discard_begin = li->discard_end = 0; | |
3086 | } | |
c6b4fcba JT |
3087 | |
3088 | return 0; | |
3089 | } | |
3090 | ||
f494a9c6 JT |
3091 | static dm_cblock_t get_cache_dev_size(struct cache *cache) |
3092 | { | |
3093 | sector_t size = get_dev_size(cache->cache_dev); | |
3094 | (void) sector_div(size, cache->sectors_per_block); | |
3095 | return to_cblock(size); | |
3096 | } | |
3097 | ||
3098 | static bool can_resize(struct cache *cache, dm_cblock_t new_size) | |
3099 | { | |
ec6ae632 MS |
3100 | if (from_cblock(new_size) > from_cblock(cache->cache_size)) { |
3101 | if (cache->sized) { | |
3102 | DMERR("%s: unable to extend cache due to missing cache table reload", | |
3103 | cache_device_name(cache)); | |
3104 | return false; | |
3105 | } | |
3106 | } | |
f494a9c6 JT |
3107 | |
3108 | /* | |
3109 | * We can't drop a dirty block when shrinking the cache. | |
3110 | */ | |
3111 | while (from_cblock(new_size) < from_cblock(cache->cache_size)) { | |
3112 | new_size = to_cblock(from_cblock(new_size) + 1); | |
3113 | if (is_dirty(cache, new_size)) { | |
b61d9509 MS |
3114 | DMERR("%s: unable to shrink cache; cache block %llu is dirty", |
3115 | cache_device_name(cache), | |
f494a9c6 JT |
3116 | (unsigned long long) from_cblock(new_size)); |
3117 | return false; | |
3118 | } | |
3119 | } | |
3120 | ||
3121 | return true; | |
3122 | } | |
3123 | ||
3124 | static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size) | |
3125 | { | |
3126 | int r; | |
3127 | ||
08844800 | 3128 | r = dm_cache_resize(cache->cmd, new_size); |
f494a9c6 | 3129 | if (r) { |
b61d9509 | 3130 | DMERR("%s: could not resize cache metadata", cache_device_name(cache)); |
028ae9f7 | 3131 | metadata_operation_failed(cache, "dm_cache_resize", r); |
f494a9c6 JT |
3132 | return r; |
3133 | } | |
3134 | ||
d1d9220c | 3135 | set_cache_size(cache, new_size); |
f494a9c6 JT |
3136 | |
3137 | return 0; | |
3138 | } | |
3139 | ||
c6b4fcba JT |
3140 | static int cache_preresume(struct dm_target *ti) |
3141 | { | |
3142 | int r = 0; | |
3143 | struct cache *cache = ti->private; | |
f494a9c6 | 3144 | dm_cblock_t csize = get_cache_dev_size(cache); |
c6b4fcba JT |
3145 | |
3146 | /* | |
3147 | * Check to see if the cache has resized. | |
3148 | */ | |
f494a9c6 JT |
3149 | if (!cache->sized) { |
3150 | r = resize_cache_dev(cache, csize); | |
3151 | if (r) | |
c6b4fcba | 3152 | return r; |
c6b4fcba JT |
3153 | |
3154 | cache->sized = true; | |
f494a9c6 JT |
3155 | |
3156 | } else if (csize != cache->cache_size) { | |
3157 | if (!can_resize(cache, csize)) | |
3158 | return -EINVAL; | |
3159 | ||
3160 | r = resize_cache_dev(cache, csize); | |
3161 | if (r) | |
3162 | return r; | |
c6b4fcba JT |
3163 | } |
3164 | ||
3165 | if (!cache->loaded_mappings) { | |
ea2dd8c1 | 3166 | r = dm_cache_load_mappings(cache->cmd, cache->policy, |
c6b4fcba JT |
3167 | load_mapping, cache); |
3168 | if (r) { | |
b61d9509 | 3169 | DMERR("%s: could not load cache mappings", cache_device_name(cache)); |
028ae9f7 | 3170 | metadata_operation_failed(cache, "dm_cache_load_mappings", r); |
c6b4fcba JT |
3171 | return r; |
3172 | } | |
3173 | ||
3174 | cache->loaded_mappings = true; | |
3175 | } | |
3176 | ||
3177 | if (!cache->loaded_discards) { | |
3e2e1c30 JT |
3178 | struct discard_load_info li; |
3179 | ||
3180 | /* | |
3181 | * The discard bitset could have been resized, or the | |
3182 | * discard block size changed. To be safe we start by | |
3183 | * setting every dblock to not discarded. | |
3184 | */ | |
3185 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); | |
3186 | ||
3187 | discard_load_info_init(cache, &li); | |
3188 | r = dm_cache_load_discards(cache->cmd, load_discard, &li); | |
c6b4fcba | 3189 | if (r) { |
b61d9509 | 3190 | DMERR("%s: could not load origin discards", cache_device_name(cache)); |
028ae9f7 | 3191 | metadata_operation_failed(cache, "dm_cache_load_discards", r); |
c6b4fcba JT |
3192 | return r; |
3193 | } | |
3e2e1c30 | 3194 | set_discard_range(&li); |
c6b4fcba JT |
3195 | |
3196 | cache->loaded_discards = true; | |
3197 | } | |
3198 | ||
3199 | return r; | |
3200 | } | |
3201 | ||
3202 | static void cache_resume(struct dm_target *ti) | |
3203 | { | |
3204 | struct cache *cache = ti->private; | |
3205 | ||
3206 | cache->need_tick_bio = true; | |
b29d4986 | 3207 | allow_background_work(cache); |
c6b4fcba JT |
3208 | do_waker(&cache->waker.work); |
3209 | } | |
3210 | ||
3211 | /* | |
3212 | * Status format: | |
3213 | * | |
6a388618 MS |
3214 | * <metadata block size> <#used metadata blocks>/<#total metadata blocks> |
3215 | * <cache block size> <#used cache blocks>/<#total cache blocks> | |
c6b4fcba | 3216 | * <#read hits> <#read misses> <#write hits> <#write misses> |
6a388618 | 3217 | * <#demotions> <#promotions> <#dirty> |
c6b4fcba JT |
3218 | * <#features> <features>* |
3219 | * <#core args> <core args> | |
255eac20 | 3220 | * <policy name> <#policy args> <policy args>* <cache metadata mode> <needs_check> |
c6b4fcba JT |
3221 | */ |
3222 | static void cache_status(struct dm_target *ti, status_type_t type, | |
3223 | unsigned status_flags, char *result, unsigned maxlen) | |
3224 | { | |
3225 | int r = 0; | |
3226 | unsigned i; | |
3227 | ssize_t sz = 0; | |
3228 | dm_block_t nr_free_blocks_metadata = 0; | |
3229 | dm_block_t nr_blocks_metadata = 0; | |
3230 | char buf[BDEVNAME_SIZE]; | |
3231 | struct cache *cache = ti->private; | |
3232 | dm_cblock_t residency; | |
d14fcf3d | 3233 | bool needs_check; |
c6b4fcba JT |
3234 | |
3235 | switch (type) { | |
3236 | case STATUSTYPE_INFO: | |
028ae9f7 JT |
3237 | if (get_cache_mode(cache) == CM_FAIL) { |
3238 | DMEMIT("Fail"); | |
3239 | break; | |
c6b4fcba JT |
3240 | } |
3241 | ||
028ae9f7 JT |
3242 | /* Commit to ensure statistics aren't out-of-date */ |
3243 | if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) | |
3244 | (void) commit(cache, false); | |
3245 | ||
b61d9509 | 3246 | r = dm_cache_get_free_metadata_block_count(cache->cmd, &nr_free_blocks_metadata); |
c6b4fcba | 3247 | if (r) { |
b61d9509 MS |
3248 | DMERR("%s: dm_cache_get_free_metadata_block_count returned %d", |
3249 | cache_device_name(cache), r); | |
c6b4fcba JT |
3250 | goto err; |
3251 | } | |
3252 | ||
3253 | r = dm_cache_get_metadata_dev_size(cache->cmd, &nr_blocks_metadata); | |
3254 | if (r) { | |
b61d9509 MS |
3255 | DMERR("%s: dm_cache_get_metadata_dev_size returned %d", |
3256 | cache_device_name(cache), r); | |
c6b4fcba JT |
3257 | goto err; |
3258 | } | |
3259 | ||
3260 | residency = policy_residency(cache->policy); | |
3261 | ||
ca763d0a | 3262 | DMEMIT("%u %llu/%llu %llu %llu/%llu %u %u %u %u %u %u %lu ", |
895b47d7 | 3263 | (unsigned)DM_CACHE_METADATA_BLOCK_SIZE, |
c6b4fcba JT |
3264 | (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), |
3265 | (unsigned long long)nr_blocks_metadata, | |
ca763d0a | 3266 | (unsigned long long)cache->sectors_per_block, |
6a388618 MS |
3267 | (unsigned long long) from_cblock(residency), |
3268 | (unsigned long long) from_cblock(cache->cache_size), | |
c6b4fcba JT |
3269 | (unsigned) atomic_read(&cache->stats.read_hit), |
3270 | (unsigned) atomic_read(&cache->stats.read_miss), | |
3271 | (unsigned) atomic_read(&cache->stats.write_hit), | |
3272 | (unsigned) atomic_read(&cache->stats.write_miss), | |
3273 | (unsigned) atomic_read(&cache->stats.demotion), | |
3274 | (unsigned) atomic_read(&cache->stats.promotion), | |
44fa816b | 3275 | (unsigned long) atomic_read(&cache->nr_dirty)); |
c6b4fcba | 3276 | |
629d0a8a JT |
3277 | if (cache->features.metadata_version == 2) |
3278 | DMEMIT("2 metadata2 "); | |
3279 | else | |
3280 | DMEMIT("1 "); | |
3281 | ||
2ee57d58 | 3282 | if (writethrough_mode(&cache->features)) |
629d0a8a | 3283 | DMEMIT("writethrough "); |
2ee57d58 JT |
3284 | |
3285 | else if (passthrough_mode(&cache->features)) | |
629d0a8a | 3286 | DMEMIT("passthrough "); |
2ee57d58 JT |
3287 | |
3288 | else if (writeback_mode(&cache->features)) | |
629d0a8a | 3289 | DMEMIT("writeback "); |
2ee57d58 JT |
3290 | |
3291 | else { | |
b61d9509 MS |
3292 | DMERR("%s: internal error: unknown io mode: %d", |
3293 | cache_device_name(cache), (int) cache->features.io_mode); | |
2ee57d58 JT |
3294 | goto err; |
3295 | } | |
c6b4fcba JT |
3296 | |
3297 | DMEMIT("2 migration_threshold %llu ", (unsigned long long) cache->migration_threshold); | |
2e68c4e6 MS |
3298 | |
3299 | DMEMIT("%s ", dm_cache_policy_get_name(cache->policy)); | |
c6b4fcba | 3300 | if (sz < maxlen) { |
028ae9f7 | 3301 | r = policy_emit_config_values(cache->policy, result, maxlen, &sz); |
c6b4fcba | 3302 | if (r) |
b61d9509 MS |
3303 | DMERR("%s: policy_emit_config_values returned %d", |
3304 | cache_device_name(cache), r); | |
c6b4fcba JT |
3305 | } |
3306 | ||
028ae9f7 JT |
3307 | if (get_cache_mode(cache) == CM_READ_ONLY) |
3308 | DMEMIT("ro "); | |
3309 | else | |
3310 | DMEMIT("rw "); | |
3311 | ||
d14fcf3d JT |
3312 | r = dm_cache_metadata_needs_check(cache->cmd, &needs_check); |
3313 | ||
3314 | if (r || needs_check) | |
255eac20 MS |
3315 | DMEMIT("needs_check "); |
3316 | else | |
3317 | DMEMIT("- "); | |
3318 | ||
c6b4fcba JT |
3319 | break; |
3320 | ||
3321 | case STATUSTYPE_TABLE: | |
3322 | format_dev_t(buf, cache->metadata_dev->bdev->bd_dev); | |
3323 | DMEMIT("%s ", buf); | |
3324 | format_dev_t(buf, cache->cache_dev->bdev->bd_dev); | |
3325 | DMEMIT("%s ", buf); | |
3326 | format_dev_t(buf, cache->origin_dev->bdev->bd_dev); | |
3327 | DMEMIT("%s", buf); | |
3328 | ||
3329 | for (i = 0; i < cache->nr_ctr_args - 1; i++) | |
3330 | DMEMIT(" %s", cache->ctr_args[i]); | |
3331 | if (cache->nr_ctr_args) | |
3332 | DMEMIT(" %s", cache->ctr_args[cache->nr_ctr_args - 1]); | |
3333 | } | |
3334 | ||
3335 | return; | |
3336 | ||
3337 | err: | |
3338 | DMEMIT("Error"); | |
3339 | } | |
3340 | ||
b29d4986 JT |
3341 | /* |
3342 | * Defines a range of cblocks, begin to (end - 1) are in the range. end is | |
3343 | * the one-past-the-end value. | |
3344 | */ | |
3345 | struct cblock_range { | |
3346 | dm_cblock_t begin; | |
3347 | dm_cblock_t end; | |
3348 | }; | |
3349 | ||
c6b4fcba | 3350 | /* |
65790ff9 JT |
3351 | * A cache block range can take two forms: |
3352 | * | |
3353 | * i) A single cblock, eg. '3456' | |
b29d4986 | 3354 | * ii) A begin and end cblock with a dash between, eg. 123-234 |
65790ff9 JT |
3355 | */ |
3356 | static int parse_cblock_range(struct cache *cache, const char *str, | |
3357 | struct cblock_range *result) | |
3358 | { | |
3359 | char dummy; | |
3360 | uint64_t b, e; | |
3361 | int r; | |
3362 | ||
3363 | /* | |
3364 | * Try and parse form (ii) first. | |
3365 | */ | |
3366 | r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy); | |
3367 | if (r < 0) | |
3368 | return r; | |
3369 | ||
3370 | if (r == 2) { | |
3371 | result->begin = to_cblock(b); | |
3372 | result->end = to_cblock(e); | |
3373 | return 0; | |
3374 | } | |
3375 | ||
3376 | /* | |
3377 | * That didn't work, try form (i). | |
3378 | */ | |
3379 | r = sscanf(str, "%llu%c", &b, &dummy); | |
3380 | if (r < 0) | |
3381 | return r; | |
3382 | ||
3383 | if (r == 1) { | |
3384 | result->begin = to_cblock(b); | |
3385 | result->end = to_cblock(from_cblock(result->begin) + 1u); | |
3386 | return 0; | |
3387 | } | |
3388 | ||
b61d9509 | 3389 | DMERR("%s: invalid cblock range '%s'", cache_device_name(cache), str); |
65790ff9 JT |
3390 | return -EINVAL; |
3391 | } | |
3392 | ||
3393 | static int validate_cblock_range(struct cache *cache, struct cblock_range *range) | |
3394 | { | |
3395 | uint64_t b = from_cblock(range->begin); | |
3396 | uint64_t e = from_cblock(range->end); | |
3397 | uint64_t n = from_cblock(cache->cache_size); | |
3398 | ||
3399 | if (b >= n) { | |
b61d9509 MS |
3400 | DMERR("%s: begin cblock out of range: %llu >= %llu", |
3401 | cache_device_name(cache), b, n); | |
65790ff9 JT |
3402 | return -EINVAL; |
3403 | } | |
3404 | ||
3405 | if (e > n) { | |
b61d9509 MS |
3406 | DMERR("%s: end cblock out of range: %llu > %llu", |
3407 | cache_device_name(cache), e, n); | |
65790ff9 JT |
3408 | return -EINVAL; |
3409 | } | |
3410 | ||
3411 | if (b >= e) { | |
b61d9509 MS |
3412 | DMERR("%s: invalid cblock range: %llu >= %llu", |
3413 | cache_device_name(cache), b, e); | |
65790ff9 JT |
3414 | return -EINVAL; |
3415 | } | |
3416 | ||
3417 | return 0; | |
3418 | } | |
3419 | ||
b29d4986 JT |
3420 | static inline dm_cblock_t cblock_succ(dm_cblock_t b) |
3421 | { | |
3422 | return to_cblock(from_cblock(b) + 1); | |
3423 | } | |
3424 | ||
65790ff9 JT |
3425 | static int request_invalidation(struct cache *cache, struct cblock_range *range) |
3426 | { | |
b29d4986 | 3427 | int r = 0; |
65790ff9 | 3428 | |
b29d4986 JT |
3429 | /* |
3430 | * We don't need to do any locking here because we know we're in | |
3431 | * passthrough mode. There's is potential for a race between an | |
3432 | * invalidation triggered by an io and an invalidation message. This | |
3433 | * is harmless, we must not worry if the policy call fails. | |
3434 | */ | |
3435 | while (range->begin != range->end) { | |
3436 | r = invalidate_cblock(cache, range->begin); | |
3437 | if (r) | |
3438 | return r; | |
65790ff9 | 3439 | |
b29d4986 JT |
3440 | range->begin = cblock_succ(range->begin); |
3441 | } | |
65790ff9 | 3442 | |
b29d4986 JT |
3443 | cache->commit_requested = true; |
3444 | return r; | |
65790ff9 JT |
3445 | } |
3446 | ||
3447 | static int process_invalidate_cblocks_message(struct cache *cache, unsigned count, | |
3448 | const char **cblock_ranges) | |
3449 | { | |
3450 | int r = 0; | |
3451 | unsigned i; | |
3452 | struct cblock_range range; | |
3453 | ||
3454 | if (!passthrough_mode(&cache->features)) { | |
b61d9509 MS |
3455 | DMERR("%s: cache has to be in passthrough mode for invalidation", |
3456 | cache_device_name(cache)); | |
65790ff9 JT |
3457 | return -EPERM; |
3458 | } | |
3459 | ||
3460 | for (i = 0; i < count; i++) { | |
3461 | r = parse_cblock_range(cache, cblock_ranges[i], &range); | |
3462 | if (r) | |
3463 | break; | |
3464 | ||
3465 | r = validate_cblock_range(cache, &range); | |
3466 | if (r) | |
3467 | break; | |
3468 | ||
3469 | /* | |
3470 | * Pass begin and end origin blocks to the worker and wake it. | |
3471 | */ | |
3472 | r = request_invalidation(cache, &range); | |
3473 | if (r) | |
3474 | break; | |
3475 | } | |
3476 | ||
3477 | return r; | |
3478 | } | |
3479 | ||
3480 | /* | |
3481 | * Supports | |
3482 | * "<key> <value>" | |
3483 | * and | |
3484 | * "invalidate_cblocks [(<begin>)|(<begin>-<end>)]* | |
c6b4fcba JT |
3485 | * |
3486 | * The key migration_threshold is supported by the cache target core. | |
3487 | */ | |
3488 | static int cache_message(struct dm_target *ti, unsigned argc, char **argv) | |
3489 | { | |
c6b4fcba JT |
3490 | struct cache *cache = ti->private; |
3491 | ||
65790ff9 JT |
3492 | if (!argc) |
3493 | return -EINVAL; | |
3494 | ||
028ae9f7 | 3495 | if (get_cache_mode(cache) >= CM_READ_ONLY) { |
b61d9509 MS |
3496 | DMERR("%s: unable to service cache target messages in READ_ONLY or FAIL mode", |
3497 | cache_device_name(cache)); | |
028ae9f7 JT |
3498 | return -EOPNOTSUPP; |
3499 | } | |
3500 | ||
7b6b2bc9 | 3501 | if (!strcasecmp(argv[0], "invalidate_cblocks")) |
65790ff9 JT |
3502 | return process_invalidate_cblocks_message(cache, argc - 1, (const char **) argv + 1); |
3503 | ||
c6b4fcba JT |
3504 | if (argc != 2) |
3505 | return -EINVAL; | |
3506 | ||
2f14f4b5 | 3507 | return set_config_value(cache, argv[0], argv[1]); |
c6b4fcba JT |
3508 | } |
3509 | ||
3510 | static int cache_iterate_devices(struct dm_target *ti, | |
3511 | iterate_devices_callout_fn fn, void *data) | |
3512 | { | |
3513 | int r = 0; | |
3514 | struct cache *cache = ti->private; | |
3515 | ||
3516 | r = fn(ti, cache->cache_dev, 0, get_dev_size(cache->cache_dev), data); | |
3517 | if (!r) | |
3518 | r = fn(ti, cache->origin_dev, 0, ti->len, data); | |
3519 | ||
3520 | return r; | |
3521 | } | |
3522 | ||
c6b4fcba JT |
3523 | static void set_discard_limits(struct cache *cache, struct queue_limits *limits) |
3524 | { | |
3525 | /* | |
3526 | * FIXME: these limits may be incompatible with the cache device | |
3527 | */ | |
7ae34e77 JT |
3528 | limits->max_discard_sectors = min_t(sector_t, cache->discard_block_size * 1024, |
3529 | cache->origin_sectors); | |
1bad9bc4 | 3530 | limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT; |
c6b4fcba JT |
3531 | } |
3532 | ||
3533 | static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
3534 | { | |
3535 | struct cache *cache = ti->private; | |
f6109372 | 3536 | uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; |
c6b4fcba | 3537 | |
f6109372 MS |
3538 | /* |
3539 | * If the system-determined stacked limits are compatible with the | |
3540 | * cache's blocksize (io_opt is a factor) do not override them. | |
3541 | */ | |
3542 | if (io_opt_sectors < cache->sectors_per_block || | |
3543 | do_div(io_opt_sectors, cache->sectors_per_block)) { | |
b0246530 | 3544 | blk_limits_io_min(limits, cache->sectors_per_block << SECTOR_SHIFT); |
f6109372 MS |
3545 | blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT); |
3546 | } | |
c6b4fcba JT |
3547 | set_discard_limits(cache, limits); |
3548 | } | |
3549 | ||
3550 | /*----------------------------------------------------------------*/ | |
3551 | ||
3552 | static struct target_type cache_target = { | |
3553 | .name = "cache", | |
b29d4986 | 3554 | .version = {2, 0, 0}, |
c6b4fcba JT |
3555 | .module = THIS_MODULE, |
3556 | .ctr = cache_ctr, | |
3557 | .dtr = cache_dtr, | |
3558 | .map = cache_map, | |
3559 | .end_io = cache_end_io, | |
3560 | .postsuspend = cache_postsuspend, | |
3561 | .preresume = cache_preresume, | |
3562 | .resume = cache_resume, | |
3563 | .status = cache_status, | |
3564 | .message = cache_message, | |
3565 | .iterate_devices = cache_iterate_devices, | |
c6b4fcba JT |
3566 | .io_hints = cache_io_hints, |
3567 | }; | |
3568 | ||
3569 | static int __init dm_cache_init(void) | |
3570 | { | |
3571 | int r; | |
3572 | ||
c6b4fcba | 3573 | migration_cache = KMEM_CACHE(dm_cache_migration, 0); |
6c8faa19 | 3574 | if (!migration_cache) |
c6b4fcba | 3575 | return -ENOMEM; |
c6b4fcba | 3576 | |
fbce429b | 3577 | r = dm_register_target(&cache_target); |
3578 | if (r) { | |
3579 | DMERR("cache target registration failed: %d", r); | |
6c8faa19 | 3580 | kmem_cache_destroy(migration_cache); |
fbce429b | 3581 | return r; |
3582 | } | |
3583 | ||
c6b4fcba JT |
3584 | return 0; |
3585 | } | |
3586 | ||
3587 | static void __exit dm_cache_exit(void) | |
3588 | { | |
3589 | dm_unregister_target(&cache_target); | |
3590 | kmem_cache_destroy(migration_cache); | |
3591 | } | |
3592 | ||
3593 | module_init(dm_cache_init); | |
3594 | module_exit(dm_cache_exit); | |
3595 | ||
3596 | MODULE_DESCRIPTION(DM_NAME " cache target"); | |
3597 | MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); | |
3598 | MODULE_LICENSE("GPL"); |