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Commit | Line | Data |
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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; | |
77289d32 | 77 | |
26b924b9 | 78 | spin_lock_irq(&iot->lock); |
77289d32 | 79 | r = __iot_idle_for(iot, jifs); |
26b924b9 | 80 | spin_unlock_irq(&iot->lock); |
77289d32 JT |
81 | |
82 | return r; | |
83 | } | |
84 | ||
85 | static void iot_io_begin(struct io_tracker *iot, sector_t len) | |
86 | { | |
26b924b9 | 87 | spin_lock_irq(&iot->lock); |
77289d32 | 88 | iot->in_flight += len; |
26b924b9 | 89 | spin_unlock_irq(&iot->lock); |
77289d32 JT |
90 | } |
91 | ||
92 | static void __iot_io_end(struct io_tracker *iot, sector_t len) | |
93 | { | |
072792dc JT |
94 | if (!len) |
95 | return; | |
96 | ||
77289d32 JT |
97 | iot->in_flight -= len; |
98 | if (!iot->in_flight) | |
99 | iot->idle_time = jiffies; | |
100 | } | |
101 | ||
102 | static void iot_io_end(struct io_tracker *iot, sector_t len) | |
103 | { | |
104 | unsigned long flags; | |
105 | ||
106 | spin_lock_irqsave(&iot->lock, flags); | |
107 | __iot_io_end(iot, len); | |
108 | spin_unlock_irqrestore(&iot->lock, flags); | |
109 | } | |
110 | ||
111 | /*----------------------------------------------------------------*/ | |
112 | ||
c6b4fcba | 113 | /* |
b29d4986 JT |
114 | * Represents a chunk of future work. 'input' allows continuations to pass |
115 | * values between themselves, typically error values. | |
c6b4fcba | 116 | */ |
b29d4986 JT |
117 | struct continuation { |
118 | struct work_struct ws; | |
4e4cbee9 | 119 | blk_status_t input; |
b29d4986 JT |
120 | }; |
121 | ||
122 | static inline void init_continuation(struct continuation *k, | |
123 | void (*fn)(struct work_struct *)) | |
124 | { | |
125 | INIT_WORK(&k->ws, fn); | |
126 | k->input = 0; | |
127 | } | |
128 | ||
129 | static inline void queue_continuation(struct workqueue_struct *wq, | |
130 | struct continuation *k) | |
131 | { | |
132 | queue_work(wq, &k->ws); | |
133 | } | |
c6b4fcba JT |
134 | |
135 | /*----------------------------------------------------------------*/ | |
136 | ||
b29d4986 JT |
137 | /* |
138 | * The batcher collects together pieces of work that need a particular | |
139 | * operation to occur before they can proceed (typically a commit). | |
140 | */ | |
141 | struct batcher { | |
142 | /* | |
143 | * The operation that everyone is waiting for. | |
144 | */ | |
4e4cbee9 | 145 | blk_status_t (*commit_op)(void *context); |
b29d4986 JT |
146 | void *commit_context; |
147 | ||
148 | /* | |
149 | * This is how bios should be issued once the commit op is complete | |
150 | * (accounted_request). | |
151 | */ | |
152 | void (*issue_op)(struct bio *bio, void *context); | |
153 | void *issue_context; | |
154 | ||
155 | /* | |
156 | * Queued work gets put on here after commit. | |
157 | */ | |
158 | struct workqueue_struct *wq; | |
159 | ||
160 | spinlock_t lock; | |
161 | struct list_head work_items; | |
162 | struct bio_list bios; | |
163 | struct work_struct commit_work; | |
164 | ||
165 | bool commit_scheduled; | |
166 | }; | |
167 | ||
168 | static void __commit(struct work_struct *_ws) | |
169 | { | |
170 | struct batcher *b = container_of(_ws, struct batcher, commit_work); | |
4e4cbee9 | 171 | blk_status_t r; |
b29d4986 JT |
172 | struct list_head work_items; |
173 | struct work_struct *ws, *tmp; | |
174 | struct continuation *k; | |
175 | struct bio *bio; | |
176 | struct bio_list bios; | |
177 | ||
178 | INIT_LIST_HEAD(&work_items); | |
179 | bio_list_init(&bios); | |
180 | ||
181 | /* | |
182 | * We have to grab these before the commit_op to avoid a race | |
183 | * condition. | |
184 | */ | |
26b924b9 | 185 | spin_lock_irq(&b->lock); |
b29d4986 JT |
186 | list_splice_init(&b->work_items, &work_items); |
187 | bio_list_merge(&bios, &b->bios); | |
188 | bio_list_init(&b->bios); | |
189 | b->commit_scheduled = false; | |
26b924b9 | 190 | spin_unlock_irq(&b->lock); |
b29d4986 JT |
191 | |
192 | r = b->commit_op(b->commit_context); | |
193 | ||
194 | list_for_each_entry_safe(ws, tmp, &work_items, entry) { | |
195 | k = container_of(ws, struct continuation, ws); | |
196 | k->input = r; | |
197 | INIT_LIST_HEAD(&ws->entry); /* to avoid a WARN_ON */ | |
198 | queue_work(b->wq, ws); | |
199 | } | |
200 | ||
201 | while ((bio = bio_list_pop(&bios))) { | |
202 | if (r) { | |
4e4cbee9 | 203 | bio->bi_status = r; |
b29d4986 JT |
204 | bio_endio(bio); |
205 | } else | |
206 | b->issue_op(bio, b->issue_context); | |
207 | } | |
208 | } | |
209 | ||
210 | static void batcher_init(struct batcher *b, | |
4e4cbee9 | 211 | blk_status_t (*commit_op)(void *), |
b29d4986 JT |
212 | void *commit_context, |
213 | void (*issue_op)(struct bio *bio, void *), | |
214 | void *issue_context, | |
215 | struct workqueue_struct *wq) | |
216 | { | |
217 | b->commit_op = commit_op; | |
218 | b->commit_context = commit_context; | |
219 | b->issue_op = issue_op; | |
220 | b->issue_context = issue_context; | |
221 | b->wq = wq; | |
222 | ||
223 | spin_lock_init(&b->lock); | |
224 | INIT_LIST_HEAD(&b->work_items); | |
225 | bio_list_init(&b->bios); | |
226 | INIT_WORK(&b->commit_work, __commit); | |
227 | b->commit_scheduled = false; | |
228 | } | |
229 | ||
230 | static void async_commit(struct batcher *b) | |
231 | { | |
232 | queue_work(b->wq, &b->commit_work); | |
233 | } | |
234 | ||
235 | static void continue_after_commit(struct batcher *b, struct continuation *k) | |
236 | { | |
b29d4986 JT |
237 | bool commit_scheduled; |
238 | ||
26b924b9 | 239 | spin_lock_irq(&b->lock); |
b29d4986 JT |
240 | commit_scheduled = b->commit_scheduled; |
241 | list_add_tail(&k->ws.entry, &b->work_items); | |
26b924b9 | 242 | spin_unlock_irq(&b->lock); |
b29d4986 JT |
243 | |
244 | if (commit_scheduled) | |
245 | async_commit(b); | |
246 | } | |
247 | ||
248 | /* | |
249 | * Bios are errored if commit failed. | |
250 | */ | |
251 | static void issue_after_commit(struct batcher *b, struct bio *bio) | |
252 | { | |
b29d4986 JT |
253 | bool commit_scheduled; |
254 | ||
26b924b9 | 255 | spin_lock_irq(&b->lock); |
b29d4986 JT |
256 | commit_scheduled = b->commit_scheduled; |
257 | bio_list_add(&b->bios, bio); | |
26b924b9 | 258 | spin_unlock_irq(&b->lock); |
b29d4986 JT |
259 | |
260 | if (commit_scheduled) | |
261 | async_commit(b); | |
262 | } | |
263 | ||
264 | /* | |
265 | * Call this if some urgent work is waiting for the commit to complete. | |
266 | */ | |
267 | static void schedule_commit(struct batcher *b) | |
268 | { | |
269 | bool immediate; | |
b29d4986 | 270 | |
26b924b9 | 271 | spin_lock_irq(&b->lock); |
b29d4986 JT |
272 | immediate = !list_empty(&b->work_items) || !bio_list_empty(&b->bios); |
273 | b->commit_scheduled = true; | |
26b924b9 | 274 | spin_unlock_irq(&b->lock); |
b29d4986 JT |
275 | |
276 | if (immediate) | |
277 | async_commit(b); | |
278 | } | |
279 | ||
c9d28d5d JT |
280 | /* |
281 | * There are a couple of places where we let a bio run, but want to do some | |
282 | * work before calling its endio function. We do this by temporarily | |
283 | * changing the endio fn. | |
284 | */ | |
285 | struct dm_hook_info { | |
286 | bio_end_io_t *bi_end_io; | |
c9d28d5d JT |
287 | }; |
288 | ||
289 | static void dm_hook_bio(struct dm_hook_info *h, struct bio *bio, | |
290 | bio_end_io_t *bi_end_io, void *bi_private) | |
291 | { | |
292 | h->bi_end_io = bio->bi_end_io; | |
c9d28d5d JT |
293 | |
294 | bio->bi_end_io = bi_end_io; | |
295 | bio->bi_private = bi_private; | |
296 | } | |
297 | ||
298 | static void dm_unhook_bio(struct dm_hook_info *h, struct bio *bio) | |
299 | { | |
300 | bio->bi_end_io = h->bi_end_io; | |
c9d28d5d JT |
301 | } |
302 | ||
303 | /*----------------------------------------------------------------*/ | |
304 | ||
c6b4fcba JT |
305 | #define MIGRATION_POOL_SIZE 128 |
306 | #define COMMIT_PERIOD HZ | |
307 | #define MIGRATION_COUNT_WINDOW 10 | |
308 | ||
309 | /* | |
05473044 MS |
310 | * The block size of the device holding cache data must be |
311 | * between 32KB and 1GB. | |
c6b4fcba JT |
312 | */ |
313 | #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (32 * 1024 >> SECTOR_SHIFT) | |
05473044 | 314 | #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT) |
c6b4fcba | 315 | |
2ee57d58 | 316 | enum cache_metadata_mode { |
c6b4fcba JT |
317 | CM_WRITE, /* metadata may be changed */ |
318 | CM_READ_ONLY, /* metadata may not be changed */ | |
028ae9f7 | 319 | CM_FAIL |
c6b4fcba JT |
320 | }; |
321 | ||
2ee57d58 JT |
322 | enum cache_io_mode { |
323 | /* | |
324 | * Data is written to cached blocks only. These blocks are marked | |
325 | * dirty. If you lose the cache device you will lose data. | |
326 | * Potential performance increase for both reads and writes. | |
327 | */ | |
328 | CM_IO_WRITEBACK, | |
329 | ||
330 | /* | |
331 | * Data is written to both cache and origin. Blocks are never | |
332 | * dirty. Potential performance benfit for reads only. | |
333 | */ | |
334 | CM_IO_WRITETHROUGH, | |
335 | ||
336 | /* | |
337 | * A degraded mode useful for various cache coherency situations | |
338 | * (eg, rolling back snapshots). Reads and writes always go to the | |
339 | * origin. If a write goes to a cached oblock, then the cache | |
340 | * block is invalidated. | |
341 | */ | |
342 | CM_IO_PASSTHROUGH | |
343 | }; | |
344 | ||
c6b4fcba | 345 | struct cache_features { |
2ee57d58 JT |
346 | enum cache_metadata_mode mode; |
347 | enum cache_io_mode io_mode; | |
629d0a8a | 348 | unsigned metadata_version; |
de7180ff | 349 | bool discard_passdown:1; |
c6b4fcba JT |
350 | }; |
351 | ||
352 | struct cache_stats { | |
353 | atomic_t read_hit; | |
354 | atomic_t read_miss; | |
355 | atomic_t write_hit; | |
356 | atomic_t write_miss; | |
357 | atomic_t demotion; | |
358 | atomic_t promotion; | |
b29d4986 | 359 | atomic_t writeback; |
c6b4fcba JT |
360 | atomic_t copies_avoided; |
361 | atomic_t cache_cell_clash; | |
362 | atomic_t commit_count; | |
363 | atomic_t discard_count; | |
364 | }; | |
365 | ||
366 | struct cache { | |
367 | struct dm_target *ti; | |
72d711c8 MS |
368 | spinlock_t lock; |
369 | ||
370 | /* | |
371 | * Fields for converting from sectors to blocks. | |
372 | */ | |
373 | int sectors_per_block_shift; | |
374 | sector_t sectors_per_block; | |
c6b4fcba | 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 | /* | |
72d711c8 | 405 | * Invalidation fields. |
c6b4fcba | 406 | */ |
72d711c8 MS |
407 | spinlock_t invalidation_lock; |
408 | struct list_head invalidation_requests; | |
c6b4fcba | 409 | |
c6b4fcba | 410 | sector_t migration_threshold; |
c6b4fcba | 411 | wait_queue_head_t migration_wait; |
a59db676 JT |
412 | atomic_t nr_allocated_migrations; |
413 | ||
414 | /* | |
415 | * The number of in flight migrations that are performing | |
416 | * background io. eg, promotion, writeback. | |
417 | */ | |
418 | atomic_t nr_io_migrations; | |
c6b4fcba | 419 | |
72d711c8 MS |
420 | struct bio_list deferred_bios; |
421 | ||
b29d4986 | 422 | struct rw_semaphore quiesce_lock; |
66cb1910 | 423 | |
72d711c8 | 424 | struct dm_target_callbacks callbacks; |
c6b4fcba JT |
425 | |
426 | /* | |
427 | * origin_blocks entries, discarded if set. | |
428 | */ | |
1bad9bc4 | 429 | dm_dblock_t discard_nr_blocks; |
c6b4fcba | 430 | unsigned long *discard_bitset; |
08b18451 | 431 | uint32_t discard_block_size; /* a power of 2 times sectors per block */ |
c9ec5d7c MS |
432 | |
433 | /* | |
434 | * Rather than reconstructing the table line for the status we just | |
435 | * save it and regurgitate. | |
436 | */ | |
437 | unsigned nr_ctr_args; | |
438 | const char **ctr_args; | |
c6b4fcba JT |
439 | |
440 | struct dm_kcopyd_client *copier; | |
b29d4986 | 441 | struct work_struct deferred_bio_worker; |
b29d4986 | 442 | struct work_struct migration_worker; |
72d711c8 | 443 | struct workqueue_struct *wq; |
c6b4fcba | 444 | struct delayed_work waker; |
b29d4986 | 445 | struct dm_bio_prison_v2 *prison; |
c6b4fcba | 446 | |
72d711c8 MS |
447 | /* |
448 | * cache_size entries, dirty if set | |
449 | */ | |
450 | unsigned long *dirty_bitset; | |
451 | atomic_t nr_dirty; | |
c6b4fcba | 452 | |
c6b4fcba | 453 | unsigned policy_nr_args; |
72d711c8 MS |
454 | struct dm_cache_policy *policy; |
455 | ||
456 | /* | |
457 | * Cache features such as write-through. | |
458 | */ | |
459 | struct cache_features features; | |
460 | ||
461 | struct cache_stats stats; | |
c6b4fcba JT |
462 | |
463 | bool need_tick_bio:1; | |
464 | bool sized:1; | |
65790ff9 | 465 | bool invalidate:1; |
c6b4fcba JT |
466 | bool commit_requested:1; |
467 | bool loaded_mappings:1; | |
468 | bool loaded_discards:1; | |
469 | ||
72d711c8 | 470 | struct rw_semaphore background_work_lock; |
65790ff9 | 471 | |
72d711c8 MS |
472 | struct batcher committer; |
473 | struct work_struct commit_ws; | |
066dbaa3 | 474 | |
701e03e4 | 475 | struct io_tracker tracker; |
b29d4986 | 476 | |
72d711c8 | 477 | mempool_t migration_pool; |
b29d4986 | 478 | |
72d711c8 | 479 | struct bio_set bs; |
c6b4fcba JT |
480 | }; |
481 | ||
482 | struct per_bio_data { | |
483 | bool tick:1; | |
484 | unsigned req_nr:2; | |
b29d4986 | 485 | struct dm_bio_prison_cell_v2 *cell; |
c6eda5e8 | 486 | struct dm_hook_info hook_info; |
066dbaa3 | 487 | sector_t len; |
c6b4fcba JT |
488 | }; |
489 | ||
490 | struct dm_cache_migration { | |
b29d4986 | 491 | struct continuation k; |
c6b4fcba JT |
492 | struct cache *cache; |
493 | ||
b29d4986 JT |
494 | struct policy_work *op; |
495 | struct bio *overwrite_bio; | |
496 | struct dm_bio_prison_cell_v2 *cell; | |
c6b4fcba | 497 | |
b29d4986 JT |
498 | dm_cblock_t invalidate_cblock; |
499 | dm_oblock_t invalidate_oblock; | |
c6b4fcba JT |
500 | }; |
501 | ||
b29d4986 JT |
502 | /*----------------------------------------------------------------*/ |
503 | ||
8e3c3827 | 504 | static bool writethrough_mode(struct cache *cache) |
b29d4986 | 505 | { |
8e3c3827 | 506 | return cache->features.io_mode == CM_IO_WRITETHROUGH; |
b29d4986 JT |
507 | } |
508 | ||
8e3c3827 | 509 | static bool writeback_mode(struct cache *cache) |
b29d4986 | 510 | { |
8e3c3827 | 511 | return cache->features.io_mode == CM_IO_WRITEBACK; |
b29d4986 JT |
512 | } |
513 | ||
8e3c3827 | 514 | static inline bool passthrough_mode(struct cache *cache) |
b29d4986 | 515 | { |
8e3c3827 | 516 | return unlikely(cache->features.io_mode == CM_IO_PASSTHROUGH); |
b29d4986 JT |
517 | } |
518 | ||
519 | /*----------------------------------------------------------------*/ | |
520 | ||
521 | static void wake_deferred_bio_worker(struct cache *cache) | |
522 | { | |
523 | queue_work(cache->wq, &cache->deferred_bio_worker); | |
524 | } | |
c6b4fcba | 525 | |
b29d4986 | 526 | static void wake_migration_worker(struct cache *cache) |
c6b4fcba | 527 | { |
8e3c3827 | 528 | if (passthrough_mode(cache)) |
b29d4986 JT |
529 | return; |
530 | ||
531 | queue_work(cache->wq, &cache->migration_worker); | |
c6b4fcba JT |
532 | } |
533 | ||
534 | /*----------------------------------------------------------------*/ | |
535 | ||
b29d4986 | 536 | static struct dm_bio_prison_cell_v2 *alloc_prison_cell(struct cache *cache) |
c6b4fcba | 537 | { |
13bd677a | 538 | return dm_bio_prison_alloc_cell_v2(cache->prison, GFP_NOIO); |
c6b4fcba JT |
539 | } |
540 | ||
b29d4986 | 541 | static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell_v2 *cell) |
c6b4fcba | 542 | { |
b29d4986 | 543 | dm_bio_prison_free_cell_v2(cache->prison, cell); |
c6b4fcba JT |
544 | } |
545 | ||
a59db676 JT |
546 | static struct dm_cache_migration *alloc_migration(struct cache *cache) |
547 | { | |
548 | struct dm_cache_migration *mg; | |
549 | ||
13bd677a | 550 | mg = mempool_alloc(&cache->migration_pool, GFP_NOIO); |
ef7afb36 MS |
551 | |
552 | memset(mg, 0, sizeof(*mg)); | |
553 | ||
554 | mg->cache = cache; | |
555 | atomic_inc(&cache->nr_allocated_migrations); | |
a59db676 JT |
556 | |
557 | return mg; | |
558 | } | |
559 | ||
560 | static void free_migration(struct dm_cache_migration *mg) | |
561 | { | |
88bf5184 | 562 | struct cache *cache = mg->cache; |
a59db676 | 563 | |
88bf5184 JT |
564 | if (atomic_dec_and_test(&cache->nr_allocated_migrations)) |
565 | wake_up(&cache->migration_wait); | |
566 | ||
6f1c819c | 567 | mempool_free(mg, &cache->migration_pool); |
a59db676 JT |
568 | } |
569 | ||
b29d4986 | 570 | /*----------------------------------------------------------------*/ |
c6b4fcba | 571 | |
b29d4986 | 572 | static inline dm_oblock_t oblock_succ(dm_oblock_t b) |
c6b4fcba | 573 | { |
b29d4986 | 574 | return to_oblock(from_oblock(b) + 1ull); |
c6b4fcba JT |
575 | } |
576 | ||
b29d4986 | 577 | static void build_key(dm_oblock_t begin, dm_oblock_t end, struct dm_cell_key_v2 *key) |
c6b4fcba | 578 | { |
b29d4986 JT |
579 | key->virtual = 0; |
580 | key->dev = 0; | |
581 | key->block_begin = from_oblock(begin); | |
582 | key->block_end = from_oblock(end); | |
c6b4fcba JT |
583 | } |
584 | ||
585 | /* | |
b29d4986 JT |
586 | * We have two lock levels. Level 0, which is used to prevent WRITEs, and |
587 | * level 1 which prevents *both* READs and WRITEs. | |
c6b4fcba | 588 | */ |
b29d4986 JT |
589 | #define WRITE_LOCK_LEVEL 0 |
590 | #define READ_WRITE_LOCK_LEVEL 1 | |
591 | ||
592 | static unsigned lock_level(struct bio *bio) | |
c6b4fcba | 593 | { |
b29d4986 JT |
594 | return bio_data_dir(bio) == WRITE ? |
595 | WRITE_LOCK_LEVEL : | |
596 | READ_WRITE_LOCK_LEVEL; | |
597 | } | |
c6b4fcba | 598 | |
b29d4986 JT |
599 | /*---------------------------------------------------------------- |
600 | * Per bio data | |
601 | *--------------------------------------------------------------*/ | |
c6b4fcba | 602 | |
693b960e | 603 | static struct per_bio_data *get_per_bio_data(struct bio *bio) |
b29d4986 | 604 | { |
693b960e | 605 | struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data)); |
b29d4986 JT |
606 | BUG_ON(!pb); |
607 | return pb; | |
608 | } | |
c6b4fcba | 609 | |
693b960e | 610 | static struct per_bio_data *init_per_bio_data(struct bio *bio) |
b29d4986 | 611 | { |
693b960e | 612 | struct per_bio_data *pb = get_per_bio_data(bio); |
c6b4fcba | 613 | |
b29d4986 JT |
614 | pb->tick = false; |
615 | pb->req_nr = dm_bio_get_target_bio_nr(bio); | |
616 | pb->cell = NULL; | |
617 | pb->len = 0; | |
618 | ||
619 | return pb; | |
c6b4fcba JT |
620 | } |
621 | ||
622 | /*----------------------------------------------------------------*/ | |
623 | ||
b29d4986 | 624 | static void defer_bio(struct cache *cache, struct bio *bio) |
c6b4fcba | 625 | { |
26b924b9 | 626 | spin_lock_irq(&cache->lock); |
b29d4986 | 627 | bio_list_add(&cache->deferred_bios, bio); |
26b924b9 | 628 | spin_unlock_irq(&cache->lock); |
b29d4986 JT |
629 | |
630 | wake_deferred_bio_worker(cache); | |
631 | } | |
c6b4fcba | 632 | |
b29d4986 | 633 | static void defer_bios(struct cache *cache, struct bio_list *bios) |
c6b4fcba | 634 | { |
26b924b9 | 635 | spin_lock_irq(&cache->lock); |
b29d4986 JT |
636 | bio_list_merge(&cache->deferred_bios, bios); |
637 | bio_list_init(bios); | |
26b924b9 | 638 | spin_unlock_irq(&cache->lock); |
c6b4fcba | 639 | |
b29d4986 | 640 | wake_deferred_bio_worker(cache); |
c6b4fcba JT |
641 | } |
642 | ||
b29d4986 JT |
643 | /*----------------------------------------------------------------*/ |
644 | ||
645 | static bool bio_detain_shared(struct cache *cache, dm_oblock_t oblock, struct bio *bio) | |
7ae34e77 | 646 | { |
b29d4986 | 647 | bool r; |
b29d4986 JT |
648 | struct per_bio_data *pb; |
649 | struct dm_cell_key_v2 key; | |
7ae34e77 | 650 | dm_oblock_t end = to_oblock(from_oblock(oblock) + 1ULL); |
b29d4986 | 651 | struct dm_bio_prison_cell_v2 *cell_prealloc, *cell; |
7ae34e77 | 652 | |
b29d4986 | 653 | cell_prealloc = alloc_prison_cell(cache); /* FIXME: allow wait if calling from worker */ |
b29d4986 JT |
654 | |
655 | build_key(oblock, end, &key); | |
656 | r = dm_cell_get_v2(cache->prison, &key, lock_level(bio), bio, cell_prealloc, &cell); | |
657 | if (!r) { | |
658 | /* | |
659 | * Failed to get the lock. | |
660 | */ | |
661 | free_prison_cell(cache, cell_prealloc); | |
662 | return r; | |
663 | } | |
c6b4fcba | 664 | |
b29d4986 JT |
665 | if (cell != cell_prealloc) |
666 | free_prison_cell(cache, cell_prealloc); | |
c6b4fcba | 667 | |
693b960e | 668 | pb = get_per_bio_data(bio); |
b29d4986 | 669 | pb->cell = cell; |
c6b4fcba JT |
670 | |
671 | return r; | |
672 | } | |
673 | ||
aeed1420 | 674 | /*----------------------------------------------------------------*/ |
c6b4fcba JT |
675 | |
676 | static bool is_dirty(struct cache *cache, dm_cblock_t b) | |
677 | { | |
678 | return test_bit(from_cblock(b), cache->dirty_bitset); | |
679 | } | |
680 | ||
b29d4986 | 681 | static void set_dirty(struct cache *cache, dm_cblock_t cblock) |
c6b4fcba JT |
682 | { |
683 | if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
44fa816b | 684 | atomic_inc(&cache->nr_dirty); |
b29d4986 | 685 | policy_set_dirty(cache->policy, cblock); |
c6b4fcba JT |
686 | } |
687 | } | |
688 | ||
b29d4986 JT |
689 | /* |
690 | * These two are called when setting after migrations to force the policy | |
691 | * and dirty bitset to be in sync. | |
692 | */ | |
693 | static void force_set_dirty(struct cache *cache, dm_cblock_t cblock) | |
694 | { | |
695 | if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) | |
696 | atomic_inc(&cache->nr_dirty); | |
697 | policy_set_dirty(cache->policy, cblock); | |
698 | } | |
699 | ||
700 | static void force_clear_dirty(struct cache *cache, dm_cblock_t cblock) | |
c6b4fcba JT |
701 | { |
702 | if (test_and_clear_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
44fa816b | 703 | if (atomic_dec_return(&cache->nr_dirty) == 0) |
c6b4fcba JT |
704 | dm_table_event(cache->ti->table); |
705 | } | |
b29d4986 JT |
706 | |
707 | policy_clear_dirty(cache->policy, cblock); | |
c6b4fcba JT |
708 | } |
709 | ||
710 | /*----------------------------------------------------------------*/ | |
aeed1420 | 711 | |
c6b4fcba JT |
712 | static bool block_size_is_power_of_two(struct cache *cache) |
713 | { | |
714 | return cache->sectors_per_block_shift >= 0; | |
715 | } | |
716 | ||
43aeaa29 MP |
717 | /* gcc on ARM generates spurious references to __udivdi3 and __umoddi3 */ |
718 | #if defined(CONFIG_ARM) && __GNUC__ == 4 && __GNUC_MINOR__ <= 6 | |
719 | __always_inline | |
720 | #endif | |
414dd67d JT |
721 | static dm_block_t block_div(dm_block_t b, uint32_t n) |
722 | { | |
723 | do_div(b, n); | |
724 | ||
725 | return b; | |
726 | } | |
727 | ||
7ae34e77 | 728 | static dm_block_t oblocks_per_dblock(struct cache *cache) |
1bad9bc4 | 729 | { |
7ae34e77 | 730 | dm_block_t oblocks = cache->discard_block_size; |
1bad9bc4 | 731 | |
7ae34e77 JT |
732 | if (block_size_is_power_of_two(cache)) |
733 | oblocks >>= cache->sectors_per_block_shift; | |
1bad9bc4 | 734 | else |
7ae34e77 | 735 | oblocks = block_div(oblocks, cache->sectors_per_block); |
1bad9bc4 | 736 | |
7ae34e77 JT |
737 | return oblocks; |
738 | } | |
739 | ||
740 | static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock) | |
741 | { | |
742 | return to_dblock(block_div(from_oblock(oblock), | |
743 | oblocks_per_dblock(cache))); | |
744 | } | |
1bad9bc4 | 745 | |
1bad9bc4 | 746 | static void set_discard(struct cache *cache, dm_dblock_t b) |
c6b4fcba | 747 | { |
7ae34e77 | 748 | BUG_ON(from_dblock(b) >= from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
749 | atomic_inc(&cache->stats.discard_count); |
750 | ||
26b924b9 | 751 | spin_lock_irq(&cache->lock); |
1bad9bc4 | 752 | set_bit(from_dblock(b), cache->discard_bitset); |
26b924b9 | 753 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
754 | } |
755 | ||
1bad9bc4 | 756 | static void clear_discard(struct cache *cache, dm_dblock_t b) |
c6b4fcba | 757 | { |
26b924b9 | 758 | spin_lock_irq(&cache->lock); |
1bad9bc4 | 759 | clear_bit(from_dblock(b), cache->discard_bitset); |
26b924b9 | 760 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
761 | } |
762 | ||
1bad9bc4 | 763 | static bool is_discarded(struct cache *cache, dm_dblock_t b) |
c6b4fcba JT |
764 | { |
765 | int r; | |
26b924b9 | 766 | spin_lock_irq(&cache->lock); |
1bad9bc4 | 767 | r = test_bit(from_dblock(b), cache->discard_bitset); |
26b924b9 | 768 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
769 | |
770 | return r; | |
771 | } | |
772 | ||
773 | static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b) | |
774 | { | |
775 | int r; | |
26b924b9 | 776 | spin_lock_irq(&cache->lock); |
1bad9bc4 JT |
777 | r = test_bit(from_dblock(oblock_to_dblock(cache, b)), |
778 | cache->discard_bitset); | |
26b924b9 | 779 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
780 | |
781 | return r; | |
782 | } | |
783 | ||
b29d4986 JT |
784 | /*---------------------------------------------------------------- |
785 | * Remapping | |
786 | *--------------------------------------------------------------*/ | |
787 | static void remap_to_origin(struct cache *cache, struct bio *bio) | |
c6b4fcba | 788 | { |
74d46992 | 789 | bio_set_dev(bio, cache->origin_dev->bdev); |
c6b4fcba JT |
790 | } |
791 | ||
792 | static void remap_to_cache(struct cache *cache, struct bio *bio, | |
793 | dm_cblock_t cblock) | |
794 | { | |
4f024f37 | 795 | sector_t bi_sector = bio->bi_iter.bi_sector; |
e0d849fa | 796 | sector_t block = from_cblock(cblock); |
c6b4fcba | 797 | |
74d46992 | 798 | bio_set_dev(bio, cache->cache_dev->bdev); |
c6b4fcba | 799 | if (!block_size_is_power_of_two(cache)) |
4f024f37 | 800 | bio->bi_iter.bi_sector = |
e0d849fa | 801 | (block * cache->sectors_per_block) + |
4f024f37 | 802 | sector_div(bi_sector, cache->sectors_per_block); |
c6b4fcba | 803 | else |
4f024f37 | 804 | bio->bi_iter.bi_sector = |
e0d849fa | 805 | (block << cache->sectors_per_block_shift) | |
4f024f37 | 806 | (bi_sector & (cache->sectors_per_block - 1)); |
c6b4fcba JT |
807 | } |
808 | ||
809 | static void check_if_tick_bio_needed(struct cache *cache, struct bio *bio) | |
810 | { | |
693b960e | 811 | struct per_bio_data *pb; |
c6b4fcba | 812 | |
26b924b9 | 813 | spin_lock_irq(&cache->lock); |
f73f44eb | 814 | if (cache->need_tick_bio && !op_is_flush(bio->bi_opf) && |
e6047149 | 815 | bio_op(bio) != REQ_OP_DISCARD) { |
693b960e | 816 | pb = get_per_bio_data(bio); |
c6b4fcba JT |
817 | pb->tick = true; |
818 | cache->need_tick_bio = false; | |
819 | } | |
26b924b9 | 820 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
821 | } |
822 | ||
2df3bae9 MS |
823 | static void __remap_to_origin_clear_discard(struct cache *cache, struct bio *bio, |
824 | dm_oblock_t oblock, bool bio_has_pbd) | |
c6b4fcba | 825 | { |
2df3bae9 MS |
826 | if (bio_has_pbd) |
827 | check_if_tick_bio_needed(cache, bio); | |
c6b4fcba JT |
828 | remap_to_origin(cache, bio); |
829 | if (bio_data_dir(bio) == WRITE) | |
1bad9bc4 | 830 | clear_discard(cache, oblock_to_dblock(cache, oblock)); |
c6b4fcba JT |
831 | } |
832 | ||
2df3bae9 MS |
833 | static void remap_to_origin_clear_discard(struct cache *cache, struct bio *bio, |
834 | dm_oblock_t oblock) | |
835 | { | |
836 | // FIXME: check_if_tick_bio_needed() is called way too much through this interface | |
837 | __remap_to_origin_clear_discard(cache, bio, oblock, true); | |
838 | } | |
839 | ||
c6b4fcba JT |
840 | static void remap_to_cache_dirty(struct cache *cache, struct bio *bio, |
841 | dm_oblock_t oblock, dm_cblock_t cblock) | |
842 | { | |
f8e5f01a | 843 | check_if_tick_bio_needed(cache, bio); |
c6b4fcba JT |
844 | remap_to_cache(cache, bio, cblock); |
845 | if (bio_data_dir(bio) == WRITE) { | |
b29d4986 | 846 | set_dirty(cache, cblock); |
1bad9bc4 | 847 | clear_discard(cache, oblock_to_dblock(cache, oblock)); |
c6b4fcba JT |
848 | } |
849 | } | |
850 | ||
851 | static dm_oblock_t get_bio_block(struct cache *cache, struct bio *bio) | |
852 | { | |
4f024f37 | 853 | sector_t block_nr = bio->bi_iter.bi_sector; |
c6b4fcba JT |
854 | |
855 | if (!block_size_is_power_of_two(cache)) | |
856 | (void) sector_div(block_nr, cache->sectors_per_block); | |
857 | else | |
858 | block_nr >>= cache->sectors_per_block_shift; | |
859 | ||
860 | return to_oblock(block_nr); | |
861 | } | |
862 | ||
066dbaa3 JT |
863 | static bool accountable_bio(struct cache *cache, struct bio *bio) |
864 | { | |
701e03e4 | 865 | return bio_op(bio) != REQ_OP_DISCARD; |
066dbaa3 JT |
866 | } |
867 | ||
868 | static void accounted_begin(struct cache *cache, struct bio *bio) | |
869 | { | |
693b960e | 870 | struct per_bio_data *pb; |
066dbaa3 JT |
871 | |
872 | if (accountable_bio(cache, bio)) { | |
693b960e | 873 | pb = get_per_bio_data(bio); |
066dbaa3 | 874 | pb->len = bio_sectors(bio); |
701e03e4 | 875 | iot_io_begin(&cache->tracker, pb->len); |
066dbaa3 JT |
876 | } |
877 | } | |
878 | ||
879 | static void accounted_complete(struct cache *cache, struct bio *bio) | |
880 | { | |
693b960e | 881 | struct per_bio_data *pb = get_per_bio_data(bio); |
066dbaa3 | 882 | |
701e03e4 | 883 | iot_io_end(&cache->tracker, pb->len); |
066dbaa3 JT |
884 | } |
885 | ||
886 | static void accounted_request(struct cache *cache, struct bio *bio) | |
887 | { | |
888 | accounted_begin(cache, bio); | |
889 | generic_make_request(bio); | |
890 | } | |
891 | ||
b29d4986 | 892 | static void issue_op(struct bio *bio, void *context) |
8c081b52 | 893 | { |
b29d4986 JT |
894 | struct cache *cache = context; |
895 | accounted_request(cache, bio); | |
8c081b52 JT |
896 | } |
897 | ||
e2e74d61 JT |
898 | /* |
899 | * When running in writethrough mode we need to send writes to clean blocks | |
2df3bae9 | 900 | * to both the cache and origin devices. Clone the bio and send them in parallel. |
e2e74d61 | 901 | */ |
2df3bae9 MS |
902 | static void remap_to_origin_and_cache(struct cache *cache, struct bio *bio, |
903 | dm_oblock_t oblock, dm_cblock_t cblock) | |
e2e74d61 | 904 | { |
6f1c819c | 905 | struct bio *origin_bio = bio_clone_fast(bio, GFP_NOIO, &cache->bs); |
2df3bae9 MS |
906 | |
907 | BUG_ON(!origin_bio); | |
e2e74d61 | 908 | |
2df3bae9 MS |
909 | bio_chain(origin_bio, bio); |
910 | /* | |
911 | * Passing false to __remap_to_origin_clear_discard() skips | |
912 | * all code that might use per_bio_data (since clone doesn't have it) | |
913 | */ | |
914 | __remap_to_origin_clear_discard(cache, origin_bio, oblock, false); | |
915 | submit_bio(origin_bio); | |
e2e74d61 | 916 | |
2df3bae9 | 917 | remap_to_cache(cache, bio, cblock); |
e2e74d61 JT |
918 | } |
919 | ||
028ae9f7 JT |
920 | /*---------------------------------------------------------------- |
921 | * Failure modes | |
922 | *--------------------------------------------------------------*/ | |
923 | static enum cache_metadata_mode get_cache_mode(struct cache *cache) | |
924 | { | |
925 | return cache->features.mode; | |
926 | } | |
927 | ||
b61d9509 MS |
928 | static const char *cache_device_name(struct cache *cache) |
929 | { | |
930 | return dm_device_name(dm_table_get_md(cache->ti->table)); | |
931 | } | |
932 | ||
028ae9f7 JT |
933 | static void notify_mode_switch(struct cache *cache, enum cache_metadata_mode mode) |
934 | { | |
935 | const char *descs[] = { | |
936 | "write", | |
937 | "read-only", | |
938 | "fail" | |
939 | }; | |
940 | ||
941 | dm_table_event(cache->ti->table); | |
b61d9509 MS |
942 | DMINFO("%s: switching cache to %s mode", |
943 | cache_device_name(cache), descs[(int)mode]); | |
028ae9f7 JT |
944 | } |
945 | ||
946 | static void set_cache_mode(struct cache *cache, enum cache_metadata_mode new_mode) | |
947 | { | |
d14fcf3d | 948 | bool needs_check; |
028ae9f7 JT |
949 | enum cache_metadata_mode old_mode = get_cache_mode(cache); |
950 | ||
d14fcf3d | 951 | if (dm_cache_metadata_needs_check(cache->cmd, &needs_check)) { |
23cab26d MS |
952 | DMERR("%s: unable to read needs_check flag, setting failure mode.", |
953 | cache_device_name(cache)); | |
d14fcf3d JT |
954 | new_mode = CM_FAIL; |
955 | } | |
956 | ||
028ae9f7 | 957 | if (new_mode == CM_WRITE && needs_check) { |
b61d9509 MS |
958 | DMERR("%s: unable to switch cache to write mode until repaired.", |
959 | cache_device_name(cache)); | |
028ae9f7 JT |
960 | if (old_mode != new_mode) |
961 | new_mode = old_mode; | |
962 | else | |
963 | new_mode = CM_READ_ONLY; | |
964 | } | |
965 | ||
966 | /* Never move out of fail mode */ | |
967 | if (old_mode == CM_FAIL) | |
968 | new_mode = CM_FAIL; | |
969 | ||
970 | switch (new_mode) { | |
971 | case CM_FAIL: | |
972 | case CM_READ_ONLY: | |
973 | dm_cache_metadata_set_read_only(cache->cmd); | |
974 | break; | |
975 | ||
976 | case CM_WRITE: | |
977 | dm_cache_metadata_set_read_write(cache->cmd); | |
978 | break; | |
979 | } | |
980 | ||
981 | cache->features.mode = new_mode; | |
982 | ||
983 | if (new_mode != old_mode) | |
984 | notify_mode_switch(cache, new_mode); | |
985 | } | |
986 | ||
987 | static void abort_transaction(struct cache *cache) | |
988 | { | |
b61d9509 MS |
989 | const char *dev_name = cache_device_name(cache); |
990 | ||
028ae9f7 JT |
991 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
992 | return; | |
993 | ||
994 | if (dm_cache_metadata_set_needs_check(cache->cmd)) { | |
b61d9509 | 995 | DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name); |
028ae9f7 JT |
996 | set_cache_mode(cache, CM_FAIL); |
997 | } | |
998 | ||
b61d9509 | 999 | DMERR_LIMIT("%s: aborting current metadata transaction", dev_name); |
028ae9f7 | 1000 | if (dm_cache_metadata_abort(cache->cmd)) { |
b61d9509 | 1001 | DMERR("%s: failed to abort metadata transaction", dev_name); |
028ae9f7 JT |
1002 | set_cache_mode(cache, CM_FAIL); |
1003 | } | |
1004 | } | |
1005 | ||
1006 | static void metadata_operation_failed(struct cache *cache, const char *op, int r) | |
1007 | { | |
b61d9509 MS |
1008 | DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d", |
1009 | cache_device_name(cache), op, r); | |
028ae9f7 JT |
1010 | abort_transaction(cache); |
1011 | set_cache_mode(cache, CM_READ_ONLY); | |
1012 | } | |
1013 | ||
b29d4986 JT |
1014 | /*----------------------------------------------------------------*/ |
1015 | ||
1016 | static void load_stats(struct cache *cache) | |
1017 | { | |
1018 | struct dm_cache_statistics stats; | |
1019 | ||
1020 | dm_cache_metadata_get_stats(cache->cmd, &stats); | |
1021 | atomic_set(&cache->stats.read_hit, stats.read_hits); | |
1022 | atomic_set(&cache->stats.read_miss, stats.read_misses); | |
1023 | atomic_set(&cache->stats.write_hit, stats.write_hits); | |
1024 | atomic_set(&cache->stats.write_miss, stats.write_misses); | |
1025 | } | |
1026 | ||
1027 | static void save_stats(struct cache *cache) | |
1028 | { | |
1029 | struct dm_cache_statistics stats; | |
1030 | ||
1031 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
1032 | return; | |
1033 | ||
1034 | stats.read_hits = atomic_read(&cache->stats.read_hit); | |
1035 | stats.read_misses = atomic_read(&cache->stats.read_miss); | |
1036 | stats.write_hits = atomic_read(&cache->stats.write_hit); | |
1037 | stats.write_misses = atomic_read(&cache->stats.write_miss); | |
1038 | ||
1039 | dm_cache_metadata_set_stats(cache->cmd, &stats); | |
1040 | } | |
1041 | ||
1042 | static void update_stats(struct cache_stats *stats, enum policy_operation op) | |
1043 | { | |
1044 | switch (op) { | |
1045 | case POLICY_PROMOTE: | |
1046 | atomic_inc(&stats->promotion); | |
1047 | break; | |
1048 | ||
1049 | case POLICY_DEMOTE: | |
1050 | atomic_inc(&stats->demotion); | |
1051 | break; | |
1052 | ||
1053 | case POLICY_WRITEBACK: | |
1054 | atomic_inc(&stats->writeback); | |
1055 | break; | |
1056 | } | |
1057 | } | |
1058 | ||
c6b4fcba JT |
1059 | /*---------------------------------------------------------------- |
1060 | * Migration processing | |
1061 | * | |
1062 | * Migration covers moving data from the origin device to the cache, or | |
1063 | * vice versa. | |
1064 | *--------------------------------------------------------------*/ | |
b29d4986 | 1065 | |
a59db676 | 1066 | static void inc_io_migrations(struct cache *cache) |
c6b4fcba | 1067 | { |
a59db676 | 1068 | atomic_inc(&cache->nr_io_migrations); |
c6b4fcba JT |
1069 | } |
1070 | ||
a59db676 | 1071 | static void dec_io_migrations(struct cache *cache) |
c6b4fcba | 1072 | { |
a59db676 | 1073 | atomic_dec(&cache->nr_io_migrations); |
c6b4fcba JT |
1074 | } |
1075 | ||
651f5fa2 JT |
1076 | static bool discard_or_flush(struct bio *bio) |
1077 | { | |
f73f44eb | 1078 | return bio_op(bio) == REQ_OP_DISCARD || op_is_flush(bio->bi_opf); |
651f5fa2 JT |
1079 | } |
1080 | ||
b29d4986 JT |
1081 | static void calc_discard_block_range(struct cache *cache, struct bio *bio, |
1082 | dm_dblock_t *b, dm_dblock_t *e) | |
c6b4fcba | 1083 | { |
b29d4986 JT |
1084 | sector_t sb = bio->bi_iter.bi_sector; |
1085 | sector_t se = bio_end_sector(bio); | |
651f5fa2 | 1086 | |
b29d4986 | 1087 | *b = to_dblock(dm_sector_div_up(sb, cache->discard_block_size)); |
c6b4fcba | 1088 | |
b29d4986 JT |
1089 | if (se - sb < cache->discard_block_size) |
1090 | *e = *b; | |
1091 | else | |
1092 | *e = to_dblock(block_div(se, cache->discard_block_size)); | |
c6b4fcba JT |
1093 | } |
1094 | ||
b29d4986 | 1095 | /*----------------------------------------------------------------*/ |
651f5fa2 | 1096 | |
b29d4986 | 1097 | static void prevent_background_work(struct cache *cache) |
651f5fa2 | 1098 | { |
b29d4986 JT |
1099 | lockdep_off(); |
1100 | down_write(&cache->background_work_lock); | |
1101 | lockdep_on(); | |
651f5fa2 JT |
1102 | } |
1103 | ||
b29d4986 | 1104 | static void allow_background_work(struct cache *cache) |
c6b4fcba | 1105 | { |
b29d4986 JT |
1106 | lockdep_off(); |
1107 | up_write(&cache->background_work_lock); | |
1108 | lockdep_on(); | |
c6b4fcba JT |
1109 | } |
1110 | ||
b29d4986 | 1111 | static bool background_work_begin(struct cache *cache) |
c6b4fcba | 1112 | { |
b29d4986 | 1113 | bool r; |
c6b4fcba | 1114 | |
b29d4986 JT |
1115 | lockdep_off(); |
1116 | r = down_read_trylock(&cache->background_work_lock); | |
1117 | lockdep_on(); | |
c6b4fcba | 1118 | |
b29d4986 | 1119 | return r; |
c6b4fcba JT |
1120 | } |
1121 | ||
b29d4986 | 1122 | static void background_work_end(struct cache *cache) |
c6b4fcba | 1123 | { |
b29d4986 JT |
1124 | lockdep_off(); |
1125 | up_read(&cache->background_work_lock); | |
1126 | lockdep_on(); | |
1127 | } | |
c6b4fcba | 1128 | |
b29d4986 | 1129 | /*----------------------------------------------------------------*/ |
c6b4fcba | 1130 | |
d1260e2a JT |
1131 | static bool bio_writes_complete_block(struct cache *cache, struct bio *bio) |
1132 | { | |
1133 | return (bio_data_dir(bio) == WRITE) && | |
1134 | (bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT)); | |
1135 | } | |
1136 | ||
1137 | static bool optimisable_bio(struct cache *cache, struct bio *bio, dm_oblock_t block) | |
1138 | { | |
8e3c3827 | 1139 | return writeback_mode(cache) && |
d1260e2a JT |
1140 | (is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio)); |
1141 | } | |
1142 | ||
b29d4986 JT |
1143 | static void quiesce(struct dm_cache_migration *mg, |
1144 | void (*continuation)(struct work_struct *)) | |
1145 | { | |
1146 | init_continuation(&mg->k, continuation); | |
1147 | dm_cell_quiesce_v2(mg->cache->prison, mg->cell, &mg->k.ws); | |
c6b4fcba JT |
1148 | } |
1149 | ||
b29d4986 | 1150 | static struct dm_cache_migration *ws_to_mg(struct work_struct *ws) |
c6b4fcba | 1151 | { |
b29d4986 JT |
1152 | struct continuation *k = container_of(ws, struct continuation, ws); |
1153 | return container_of(k, struct dm_cache_migration, k); | |
c6b4fcba JT |
1154 | } |
1155 | ||
1156 | static void copy_complete(int read_err, unsigned long write_err, void *context) | |
1157 | { | |
b29d4986 | 1158 | struct dm_cache_migration *mg = container_of(context, struct dm_cache_migration, k); |
c6b4fcba JT |
1159 | |
1160 | if (read_err || write_err) | |
4e4cbee9 | 1161 | mg->k.input = BLK_STS_IOERR; |
c6b4fcba | 1162 | |
b29d4986 | 1163 | queue_continuation(mg->cache->wq, &mg->k); |
c6b4fcba JT |
1164 | } |
1165 | ||
7209049d | 1166 | static void copy(struct dm_cache_migration *mg, bool promote) |
c6b4fcba | 1167 | { |
c6b4fcba JT |
1168 | struct dm_io_region o_region, c_region; |
1169 | struct cache *cache = mg->cache; | |
1170 | ||
1171 | o_region.bdev = cache->origin_dev->bdev; | |
b29d4986 | 1172 | o_region.sector = from_oblock(mg->op->oblock) * cache->sectors_per_block; |
c6b4fcba JT |
1173 | o_region.count = cache->sectors_per_block; |
1174 | ||
1175 | c_region.bdev = cache->cache_dev->bdev; | |
b29d4986 | 1176 | c_region.sector = from_cblock(mg->op->cblock) * cache->sectors_per_block; |
c6b4fcba JT |
1177 | c_region.count = cache->sectors_per_block; |
1178 | ||
b29d4986 | 1179 | if (promote) |
7209049d | 1180 | dm_kcopyd_copy(cache->copier, &o_region, 1, &c_region, 0, copy_complete, &mg->k); |
b29d4986 | 1181 | else |
7209049d | 1182 | dm_kcopyd_copy(cache->copier, &c_region, 1, &o_region, 0, copy_complete, &mg->k); |
b29d4986 JT |
1183 | } |
1184 | ||
1185 | static void bio_drop_shared_lock(struct cache *cache, struct bio *bio) | |
1186 | { | |
693b960e | 1187 | struct per_bio_data *pb = get_per_bio_data(bio); |
b29d4986 JT |
1188 | |
1189 | if (pb->cell && dm_cell_put_v2(cache->prison, pb->cell)) | |
1190 | free_prison_cell(cache, pb->cell); | |
1191 | pb->cell = NULL; | |
c6b4fcba JT |
1192 | } |
1193 | ||
4246a0b6 | 1194 | static void overwrite_endio(struct bio *bio) |
c9d28d5d JT |
1195 | { |
1196 | struct dm_cache_migration *mg = bio->bi_private; | |
1197 | struct cache *cache = mg->cache; | |
693b960e | 1198 | struct per_bio_data *pb = get_per_bio_data(bio); |
c9d28d5d | 1199 | |
80ae49aa MS |
1200 | dm_unhook_bio(&pb->hook_info, bio); |
1201 | ||
4e4cbee9 CH |
1202 | if (bio->bi_status) |
1203 | mg->k.input = bio->bi_status; | |
80ae49aa | 1204 | |
693b960e | 1205 | queue_continuation(cache->wq, &mg->k); |
c9d28d5d JT |
1206 | } |
1207 | ||
b29d4986 JT |
1208 | static void overwrite(struct dm_cache_migration *mg, |
1209 | void (*continuation)(struct work_struct *)) | |
c9d28d5d | 1210 | { |
b29d4986 | 1211 | struct bio *bio = mg->overwrite_bio; |
693b960e | 1212 | struct per_bio_data *pb = get_per_bio_data(bio); |
c9d28d5d JT |
1213 | |
1214 | dm_hook_bio(&pb->hook_info, bio, overwrite_endio, mg); | |
8c081b52 JT |
1215 | |
1216 | /* | |
b29d4986 JT |
1217 | * The overwrite bio is part of the copy operation, as such it does |
1218 | * not set/clear discard or dirty flags. | |
8c081b52 | 1219 | */ |
b29d4986 JT |
1220 | if (mg->op->op == POLICY_PROMOTE) |
1221 | remap_to_cache(mg->cache, bio, mg->op->cblock); | |
1222 | else | |
1223 | remap_to_origin(mg->cache, bio); | |
1224 | ||
1225 | init_continuation(&mg->k, continuation); | |
066dbaa3 | 1226 | accounted_request(mg->cache, bio); |
c9d28d5d JT |
1227 | } |
1228 | ||
b29d4986 JT |
1229 | /* |
1230 | * Migration steps: | |
1231 | * | |
1232 | * 1) exclusive lock preventing WRITEs | |
1233 | * 2) quiesce | |
1234 | * 3) copy or issue overwrite bio | |
1235 | * 4) upgrade to exclusive lock preventing READs and WRITEs | |
1236 | * 5) quiesce | |
1237 | * 6) update metadata and commit | |
1238 | * 7) unlock | |
1239 | */ | |
1240 | static void mg_complete(struct dm_cache_migration *mg, bool success) | |
c9d28d5d | 1241 | { |
b29d4986 JT |
1242 | struct bio_list bios; |
1243 | struct cache *cache = mg->cache; | |
1244 | struct policy_work *op = mg->op; | |
1245 | dm_cblock_t cblock = op->cblock; | |
1246 | ||
1247 | if (success) | |
1248 | update_stats(&cache->stats, op->op); | |
1249 | ||
1250 | switch (op->op) { | |
1251 | case POLICY_PROMOTE: | |
1252 | clear_discard(cache, oblock_to_dblock(cache, op->oblock)); | |
1253 | policy_complete_background_work(cache->policy, op, success); | |
1254 | ||
1255 | if (mg->overwrite_bio) { | |
1256 | if (success) | |
1257 | force_set_dirty(cache, cblock); | |
4e4cbee9 CH |
1258 | else if (mg->k.input) |
1259 | mg->overwrite_bio->bi_status = mg->k.input; | |
b29d4986 | 1260 | else |
4e4cbee9 | 1261 | mg->overwrite_bio->bi_status = BLK_STS_IOERR; |
b29d4986 JT |
1262 | bio_endio(mg->overwrite_bio); |
1263 | } else { | |
1264 | if (success) | |
1265 | force_clear_dirty(cache, cblock); | |
1266 | dec_io_migrations(cache); | |
1267 | } | |
1268 | break; | |
1269 | ||
1270 | case POLICY_DEMOTE: | |
1271 | /* | |
1272 | * We clear dirty here to update the nr_dirty counter. | |
1273 | */ | |
1274 | if (success) | |
1275 | force_clear_dirty(cache, cblock); | |
1276 | policy_complete_background_work(cache->policy, op, success); | |
1277 | dec_io_migrations(cache); | |
1278 | break; | |
1279 | ||
1280 | case POLICY_WRITEBACK: | |
1281 | if (success) | |
1282 | force_clear_dirty(cache, cblock); | |
1283 | policy_complete_background_work(cache->policy, op, success); | |
1284 | dec_io_migrations(cache); | |
1285 | break; | |
1286 | } | |
1287 | ||
1288 | bio_list_init(&bios); | |
1289 | if (mg->cell) { | |
1290 | if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios)) | |
1291 | free_prison_cell(cache, mg->cell); | |
1292 | } | |
1293 | ||
1294 | free_migration(mg); | |
1295 | defer_bios(cache, &bios); | |
1296 | wake_migration_worker(cache); | |
1297 | ||
1298 | background_work_end(cache); | |
c9d28d5d JT |
1299 | } |
1300 | ||
b29d4986 | 1301 | static void mg_success(struct work_struct *ws) |
c6b4fcba | 1302 | { |
b29d4986 JT |
1303 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1304 | mg_complete(mg, mg->k.input == 0); | |
c6b4fcba JT |
1305 | } |
1306 | ||
b29d4986 | 1307 | static void mg_update_metadata(struct work_struct *ws) |
7ae34e77 | 1308 | { |
b29d4986 JT |
1309 | int r; |
1310 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
c6b4fcba | 1311 | struct cache *cache = mg->cache; |
b29d4986 | 1312 | struct policy_work *op = mg->op; |
c6b4fcba | 1313 | |
b29d4986 JT |
1314 | switch (op->op) { |
1315 | case POLICY_PROMOTE: | |
1316 | r = dm_cache_insert_mapping(cache->cmd, op->cblock, op->oblock); | |
1317 | if (r) { | |
1318 | DMERR_LIMIT("%s: migration failed; couldn't insert mapping", | |
1319 | cache_device_name(cache)); | |
1320 | metadata_operation_failed(cache, "dm_cache_insert_mapping", r); | |
7ae34e77 | 1321 | |
b29d4986 JT |
1322 | mg_complete(mg, false); |
1323 | return; | |
1324 | } | |
1325 | mg_complete(mg, true); | |
1326 | break; | |
c9d28d5d | 1327 | |
b29d4986 JT |
1328 | case POLICY_DEMOTE: |
1329 | r = dm_cache_remove_mapping(cache->cmd, op->cblock); | |
1330 | if (r) { | |
1331 | DMERR_LIMIT("%s: migration failed; couldn't update on disk metadata", | |
1332 | cache_device_name(cache)); | |
1333 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); | |
c6b4fcba | 1334 | |
b29d4986 | 1335 | mg_complete(mg, false); |
c9d28d5d JT |
1336 | return; |
1337 | } | |
c9d28d5d | 1338 | |
b29d4986 JT |
1339 | /* |
1340 | * It would be nice if we only had to commit when a REQ_FLUSH | |
1341 | * comes through. But there's one scenario that we have to | |
1342 | * look out for: | |
1343 | * | |
1344 | * - vblock x in a cache block | |
1345 | * - domotion occurs | |
1346 | * - cache block gets reallocated and over written | |
1347 | * - crash | |
1348 | * | |
1349 | * When we recover, because there was no commit the cache will | |
1350 | * rollback to having the data for vblock x in the cache block. | |
1351 | * But the cache block has since been overwritten, so it'll end | |
1352 | * up pointing to data that was never in 'x' during the history | |
1353 | * of the device. | |
1354 | * | |
1355 | * To avoid this issue we require a commit as part of the | |
1356 | * demotion operation. | |
1357 | */ | |
1358 | init_continuation(&mg->k, mg_success); | |
1359 | continue_after_commit(&cache->committer, &mg->k); | |
1360 | schedule_commit(&cache->committer); | |
1361 | break; | |
1362 | ||
1363 | case POLICY_WRITEBACK: | |
1364 | mg_complete(mg, true); | |
1365 | break; | |
7ae34e77 | 1366 | } |
c6b4fcba JT |
1367 | } |
1368 | ||
b29d4986 | 1369 | static void mg_update_metadata_after_copy(struct work_struct *ws) |
c6b4fcba | 1370 | { |
b29d4986 JT |
1371 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1372 | ||
1373 | /* | |
1374 | * Did the copy succeed? | |
1375 | */ | |
1376 | if (mg->k.input) | |
1377 | mg_complete(mg, false); | |
c6b4fcba | 1378 | else |
b29d4986 | 1379 | mg_update_metadata(ws); |
c6b4fcba JT |
1380 | } |
1381 | ||
b29d4986 | 1382 | static void mg_upgrade_lock(struct work_struct *ws) |
c6b4fcba | 1383 | { |
b29d4986 JT |
1384 | int r; |
1385 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
c6b4fcba | 1386 | |
b29d4986 JT |
1387 | /* |
1388 | * Did the copy succeed? | |
1389 | */ | |
1390 | if (mg->k.input) | |
1391 | mg_complete(mg, false); | |
c6b4fcba | 1392 | |
c9d28d5d | 1393 | else { |
b29d4986 JT |
1394 | /* |
1395 | * Now we want the lock to prevent both reads and writes. | |
1396 | */ | |
1397 | r = dm_cell_lock_promote_v2(mg->cache->prison, mg->cell, | |
1398 | READ_WRITE_LOCK_LEVEL); | |
1399 | if (r < 0) | |
1400 | mg_complete(mg, false); | |
c6b4fcba | 1401 | |
b29d4986 JT |
1402 | else if (r) |
1403 | quiesce(mg, mg_update_metadata); | |
c6b4fcba | 1404 | |
b29d4986 JT |
1405 | else |
1406 | mg_update_metadata(ws); | |
c9d28d5d | 1407 | } |
c6b4fcba JT |
1408 | } |
1409 | ||
d1260e2a JT |
1410 | static void mg_full_copy(struct work_struct *ws) |
1411 | { | |
1412 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
1413 | struct cache *cache = mg->cache; | |
1414 | struct policy_work *op = mg->op; | |
1415 | bool is_policy_promote = (op->op == POLICY_PROMOTE); | |
1416 | ||
1417 | if ((!is_policy_promote && !is_dirty(cache, op->cblock)) || | |
1418 | is_discarded_oblock(cache, op->oblock)) { | |
1419 | mg_upgrade_lock(ws); | |
1420 | return; | |
1421 | } | |
1422 | ||
1423 | init_continuation(&mg->k, mg_upgrade_lock); | |
7209049d | 1424 | copy(mg, is_policy_promote); |
d1260e2a JT |
1425 | } |
1426 | ||
b29d4986 | 1427 | static void mg_copy(struct work_struct *ws) |
c6b4fcba | 1428 | { |
b29d4986 | 1429 | struct dm_cache_migration *mg = ws_to_mg(ws); |
c6b4fcba | 1430 | |
b29d4986 | 1431 | if (mg->overwrite_bio) { |
d1260e2a JT |
1432 | /* |
1433 | * No exclusive lock was held when we last checked if the bio | |
1434 | * was optimisable. So we have to check again in case things | |
1435 | * have changed (eg, the block may no longer be discarded). | |
1436 | */ | |
1437 | if (!optimisable_bio(mg->cache, mg->overwrite_bio, mg->op->oblock)) { | |
1438 | /* | |
1439 | * Fallback to a real full copy after doing some tidying up. | |
1440 | */ | |
1441 | bool rb = bio_detain_shared(mg->cache, mg->op->oblock, mg->overwrite_bio); | |
1442 | BUG_ON(rb); /* An exclussive lock must _not_ be held for this block */ | |
1443 | mg->overwrite_bio = NULL; | |
1444 | inc_io_migrations(mg->cache); | |
1445 | mg_full_copy(ws); | |
1446 | return; | |
1447 | } | |
1448 | ||
b29d4986 JT |
1449 | /* |
1450 | * It's safe to do this here, even though it's new data | |
1451 | * because all IO has been locked out of the block. | |
1452 | * | |
1453 | * mg_lock_writes() already took READ_WRITE_LOCK_LEVEL | |
1454 | * so _not_ using mg_upgrade_lock() as continutation. | |
1455 | */ | |
1456 | overwrite(mg, mg_update_metadata_after_copy); | |
c6b4fcba | 1457 | |
d1260e2a JT |
1458 | } else |
1459 | mg_full_copy(ws); | |
c6b4fcba JT |
1460 | } |
1461 | ||
b29d4986 | 1462 | static int mg_lock_writes(struct dm_cache_migration *mg) |
c6b4fcba | 1463 | { |
b29d4986 JT |
1464 | int r; |
1465 | struct dm_cell_key_v2 key; | |
c6b4fcba | 1466 | struct cache *cache = mg->cache; |
b29d4986 | 1467 | struct dm_bio_prison_cell_v2 *prealloc; |
c6b4fcba | 1468 | |
b29d4986 | 1469 | prealloc = alloc_prison_cell(cache); |
c6b4fcba | 1470 | |
b29d4986 JT |
1471 | /* |
1472 | * Prevent writes to the block, but allow reads to continue. | |
1473 | * Unless we're using an overwrite bio, in which case we lock | |
1474 | * everything. | |
1475 | */ | |
1476 | build_key(mg->op->oblock, oblock_succ(mg->op->oblock), &key); | |
1477 | r = dm_cell_lock_v2(cache->prison, &key, | |
1478 | mg->overwrite_bio ? READ_WRITE_LOCK_LEVEL : WRITE_LOCK_LEVEL, | |
1479 | prealloc, &mg->cell); | |
1480 | if (r < 0) { | |
1481 | free_prison_cell(cache, prealloc); | |
1482 | mg_complete(mg, false); | |
1483 | return r; | |
1484 | } | |
c6b4fcba | 1485 | |
b29d4986 JT |
1486 | if (mg->cell != prealloc) |
1487 | free_prison_cell(cache, prealloc); | |
c6b4fcba | 1488 | |
b29d4986 JT |
1489 | if (r == 0) |
1490 | mg_copy(&mg->k.ws); | |
1491 | else | |
1492 | quiesce(mg, mg_copy); | |
c6b4fcba | 1493 | |
b29d4986 | 1494 | return 0; |
c6b4fcba JT |
1495 | } |
1496 | ||
b29d4986 | 1497 | static int mg_start(struct cache *cache, struct policy_work *op, struct bio *bio) |
c6b4fcba | 1498 | { |
b29d4986 | 1499 | struct dm_cache_migration *mg; |
c6b4fcba | 1500 | |
b29d4986 JT |
1501 | if (!background_work_begin(cache)) { |
1502 | policy_complete_background_work(cache->policy, op, false); | |
1503 | return -EPERM; | |
1504 | } | |
2ee57d58 | 1505 | |
b29d4986 | 1506 | mg = alloc_migration(cache); |
2ee57d58 | 1507 | |
b29d4986 JT |
1508 | mg->op = op; |
1509 | mg->overwrite_bio = bio; | |
1510 | ||
1511 | if (!bio) | |
1512 | inc_io_migrations(cache); | |
7ae34e77 | 1513 | |
b29d4986 | 1514 | return mg_lock_writes(mg); |
7ae34e77 JT |
1515 | } |
1516 | ||
c6b4fcba | 1517 | /*---------------------------------------------------------------- |
b29d4986 | 1518 | * invalidation processing |
c6b4fcba | 1519 | *--------------------------------------------------------------*/ |
c6b4fcba | 1520 | |
b29d4986 | 1521 | static void invalidate_complete(struct dm_cache_migration *mg, bool success) |
c6b4fcba | 1522 | { |
b29d4986 JT |
1523 | struct bio_list bios; |
1524 | struct cache *cache = mg->cache; | |
c6b4fcba | 1525 | |
b29d4986 JT |
1526 | bio_list_init(&bios); |
1527 | if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios)) | |
1528 | free_prison_cell(cache, mg->cell); | |
c6b4fcba | 1529 | |
b29d4986 JT |
1530 | if (!success && mg->overwrite_bio) |
1531 | bio_io_error(mg->overwrite_bio); | |
c6b4fcba | 1532 | |
b29d4986 JT |
1533 | free_migration(mg); |
1534 | defer_bios(cache, &bios); | |
c6b4fcba | 1535 | |
b29d4986 | 1536 | background_work_end(cache); |
c6b4fcba JT |
1537 | } |
1538 | ||
b29d4986 | 1539 | static void invalidate_completed(struct work_struct *ws) |
c6b4fcba | 1540 | { |
b29d4986 JT |
1541 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1542 | invalidate_complete(mg, !mg->k.input); | |
c6b4fcba JT |
1543 | } |
1544 | ||
b29d4986 | 1545 | static int invalidate_cblock(struct cache *cache, dm_cblock_t cblock) |
651f5fa2 | 1546 | { |
b29d4986 JT |
1547 | int r = policy_invalidate_mapping(cache->policy, cblock); |
1548 | if (!r) { | |
1549 | r = dm_cache_remove_mapping(cache->cmd, cblock); | |
1550 | if (r) { | |
1551 | DMERR_LIMIT("%s: invalidation failed; couldn't update on disk metadata", | |
1552 | cache_device_name(cache)); | |
1553 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); | |
651f5fa2 JT |
1554 | } |
1555 | ||
b29d4986 JT |
1556 | } else if (r == -ENODATA) { |
1557 | /* | |
1558 | * Harmless, already unmapped. | |
1559 | */ | |
1560 | r = 0; | |
651f5fa2 | 1561 | |
b29d4986 JT |
1562 | } else |
1563 | DMERR("%s: policy_invalidate_mapping failed", cache_device_name(cache)); | |
2ee57d58 | 1564 | |
b29d4986 | 1565 | return r; |
651f5fa2 JT |
1566 | } |
1567 | ||
b29d4986 | 1568 | static void invalidate_remove(struct work_struct *ws) |
651f5fa2 | 1569 | { |
b29d4986 JT |
1570 | int r; |
1571 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
1572 | struct cache *cache = mg->cache; | |
651f5fa2 | 1573 | |
b29d4986 JT |
1574 | r = invalidate_cblock(cache, mg->invalidate_cblock); |
1575 | if (r) { | |
1576 | invalidate_complete(mg, false); | |
1577 | return; | |
651f5fa2 | 1578 | } |
9153df74 | 1579 | |
b29d4986 JT |
1580 | init_continuation(&mg->k, invalidate_completed); |
1581 | continue_after_commit(&cache->committer, &mg->k); | |
1582 | remap_to_origin_clear_discard(cache, mg->overwrite_bio, mg->invalidate_oblock); | |
1583 | mg->overwrite_bio = NULL; | |
1584 | schedule_commit(&cache->committer); | |
651f5fa2 JT |
1585 | } |
1586 | ||
b29d4986 | 1587 | static int invalidate_lock(struct dm_cache_migration *mg) |
651f5fa2 | 1588 | { |
b29d4986 JT |
1589 | int r; |
1590 | struct dm_cell_key_v2 key; | |
1591 | struct cache *cache = mg->cache; | |
1592 | struct dm_bio_prison_cell_v2 *prealloc; | |
651f5fa2 | 1593 | |
b29d4986 | 1594 | prealloc = alloc_prison_cell(cache); |
651f5fa2 | 1595 | |
b29d4986 JT |
1596 | build_key(mg->invalidate_oblock, oblock_succ(mg->invalidate_oblock), &key); |
1597 | r = dm_cell_lock_v2(cache->prison, &key, | |
1598 | READ_WRITE_LOCK_LEVEL, prealloc, &mg->cell); | |
1599 | if (r < 0) { | |
1600 | free_prison_cell(cache, prealloc); | |
1601 | invalidate_complete(mg, false); | |
1602 | return r; | |
651f5fa2 | 1603 | } |
9153df74 | 1604 | |
b29d4986 JT |
1605 | if (mg->cell != prealloc) |
1606 | free_prison_cell(cache, prealloc); | |
651f5fa2 | 1607 | |
b29d4986 JT |
1608 | if (r) |
1609 | quiesce(mg, invalidate_remove); | |
651f5fa2 | 1610 | |
b29d4986 JT |
1611 | else { |
1612 | /* | |
1613 | * We can't call invalidate_remove() directly here because we | |
1614 | * might still be in request context. | |
1615 | */ | |
1616 | init_continuation(&mg->k, invalidate_remove); | |
1617 | queue_work(cache->wq, &mg->k.ws); | |
1618 | } | |
fb4100ae | 1619 | |
fb4100ae JT |
1620 | return 0; |
1621 | } | |
1622 | ||
b29d4986 JT |
1623 | static int invalidate_start(struct cache *cache, dm_cblock_t cblock, |
1624 | dm_oblock_t oblock, struct bio *bio) | |
fb4100ae | 1625 | { |
b29d4986 | 1626 | struct dm_cache_migration *mg; |
2ee57d58 | 1627 | |
b29d4986 JT |
1628 | if (!background_work_begin(cache)) |
1629 | return -EPERM; | |
c6b4fcba | 1630 | |
b29d4986 | 1631 | mg = alloc_migration(cache); |
c6b4fcba | 1632 | |
b29d4986 JT |
1633 | mg->overwrite_bio = bio; |
1634 | mg->invalidate_cblock = cblock; | |
1635 | mg->invalidate_oblock = oblock; | |
c6b4fcba | 1636 | |
b29d4986 | 1637 | return invalidate_lock(mg); |
c6b4fcba | 1638 | } |
c6b4fcba | 1639 | |
b29d4986 JT |
1640 | /*---------------------------------------------------------------- |
1641 | * bio processing | |
1642 | *--------------------------------------------------------------*/ | |
c6b4fcba | 1643 | |
b29d4986 JT |
1644 | enum busy { |
1645 | IDLE, | |
b29d4986 JT |
1646 | BUSY |
1647 | }; | |
c6b4fcba | 1648 | |
b29d4986 | 1649 | static enum busy spare_migration_bandwidth(struct cache *cache) |
651f5fa2 | 1650 | { |
701e03e4 | 1651 | bool idle = iot_idle_for(&cache->tracker, HZ); |
a59db676 | 1652 | sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) * |
c6b4fcba | 1653 | cache->sectors_per_block; |
651f5fa2 | 1654 | |
49b7f768 JT |
1655 | if (idle && current_volume <= cache->migration_threshold) |
1656 | return IDLE; | |
b29d4986 | 1657 | else |
49b7f768 | 1658 | return BUSY; |
651f5fa2 JT |
1659 | } |
1660 | ||
c6b4fcba | 1661 | static void inc_hit_counter(struct cache *cache, struct bio *bio) |
c6b4fcba | 1662 | { |
c6b4fcba JT |
1663 | atomic_inc(bio_data_dir(bio) == READ ? |
1664 | &cache->stats.read_hit : &cache->stats.write_hit); | |
c6b4fcba JT |
1665 | } |
1666 | ||
c6b4fcba | 1667 | static void inc_miss_counter(struct cache *cache, struct bio *bio) |
028ae9f7 | 1668 | { |
c6b4fcba JT |
1669 | atomic_inc(bio_data_dir(bio) == READ ? |
1670 | &cache->stats.read_miss : &cache->stats.write_miss); | |
1671 | } | |
028ae9f7 | 1672 | |
fb4100ae | 1673 | /*----------------------------------------------------------------*/ |
028ae9f7 | 1674 | |
b29d4986 JT |
1675 | static int map_bio(struct cache *cache, struct bio *bio, dm_oblock_t block, |
1676 | bool *commit_needed) | |
c6b4fcba | 1677 | { |
b29d4986 JT |
1678 | int r, data_dir; |
1679 | bool rb, background_queued; | |
1680 | dm_cblock_t cblock; | |
c6b4fcba | 1681 | |
b29d4986 | 1682 | *commit_needed = false; |
c6b4fcba | 1683 | |
b29d4986 JT |
1684 | rb = bio_detain_shared(cache, block, bio); |
1685 | if (!rb) { | |
c6b4fcba | 1686 | /* |
b29d4986 JT |
1687 | * An exclusive lock is held for this block, so we have to |
1688 | * wait. We set the commit_needed flag so the current | |
1689 | * transaction will be committed asap, allowing this lock | |
1690 | * to be dropped. | |
c6b4fcba | 1691 | */ |
b29d4986 JT |
1692 | *commit_needed = true; |
1693 | return DM_MAPIO_SUBMITTED; | |
651f5fa2 | 1694 | } |
9153df74 | 1695 | |
b29d4986 | 1696 | data_dir = bio_data_dir(bio); |
651f5fa2 | 1697 | |
b29d4986 JT |
1698 | if (optimisable_bio(cache, bio, block)) { |
1699 | struct policy_work *op = NULL; | |
fb4100ae | 1700 | |
b29d4986 JT |
1701 | r = policy_lookup_with_work(cache->policy, block, &cblock, data_dir, true, &op); |
1702 | if (unlikely(r && r != -ENOENT)) { | |
1703 | DMERR_LIMIT("%s: policy_lookup_with_work() failed with r = %d", | |
1704 | cache_device_name(cache), r); | |
1705 | bio_io_error(bio); | |
1706 | return DM_MAPIO_SUBMITTED; | |
c6b4fcba JT |
1707 | } |
1708 | ||
b29d4986 JT |
1709 | if (r == -ENOENT && op) { |
1710 | bio_drop_shared_lock(cache, bio); | |
1711 | BUG_ON(op->op != POLICY_PROMOTE); | |
1712 | mg_start(cache, op, bio); | |
1713 | return DM_MAPIO_SUBMITTED; | |
1714 | } | |
1715 | } else { | |
1716 | r = policy_lookup(cache->policy, block, &cblock, data_dir, false, &background_queued); | |
1717 | if (unlikely(r && r != -ENOENT)) { | |
1718 | DMERR_LIMIT("%s: policy_lookup() failed with r = %d", | |
1719 | cache_device_name(cache), r); | |
1720 | bio_io_error(bio); | |
1721 | return DM_MAPIO_SUBMITTED; | |
1722 | } | |
c6b4fcba | 1723 | |
b29d4986 JT |
1724 | if (background_queued) |
1725 | wake_migration_worker(cache); | |
c6b4fcba JT |
1726 | } |
1727 | ||
b29d4986 | 1728 | if (r == -ENOENT) { |
693b960e MS |
1729 | struct per_bio_data *pb = get_per_bio_data(bio); |
1730 | ||
b29d4986 JT |
1731 | /* |
1732 | * Miss. | |
1733 | */ | |
1734 | inc_miss_counter(cache, bio); | |
1735 | if (pb->req_nr == 0) { | |
1736 | accounted_begin(cache, bio); | |
1737 | remap_to_origin_clear_discard(cache, bio, block); | |
b29d4986 | 1738 | } else { |
2ee57d58 | 1739 | /* |
b29d4986 JT |
1740 | * This is a duplicate writethrough io that is no |
1741 | * longer needed because the block has been demoted. | |
2ee57d58 | 1742 | */ |
b29d4986 JT |
1743 | bio_endio(bio); |
1744 | return DM_MAPIO_SUBMITTED; | |
1745 | } | |
1746 | } else { | |
1747 | /* | |
1748 | * Hit. | |
1749 | */ | |
1750 | inc_hit_counter(cache, bio); | |
651f5fa2 | 1751 | |
b29d4986 JT |
1752 | /* |
1753 | * Passthrough always maps to the origin, invalidating any | |
1754 | * cache blocks that are written to. | |
1755 | */ | |
8e3c3827 | 1756 | if (passthrough_mode(cache)) { |
2ee57d58 | 1757 | if (bio_data_dir(bio) == WRITE) { |
b29d4986 | 1758 | bio_drop_shared_lock(cache, bio); |
2ee57d58 | 1759 | atomic_inc(&cache->stats.demotion); |
b29d4986 JT |
1760 | invalidate_start(cache, cblock, block, bio); |
1761 | } else | |
2ee57d58 | 1762 | remap_to_origin_clear_discard(cache, bio, block); |
2ee57d58 | 1763 | } else { |
8e3c3827 | 1764 | if (bio_data_dir(bio) == WRITE && writethrough_mode(cache) && |
b29d4986 | 1765 | !is_dirty(cache, cblock)) { |
2df3bae9 | 1766 | remap_to_origin_and_cache(cache, bio, block, cblock); |
b29d4986 JT |
1767 | accounted_begin(cache, bio); |
1768 | } else | |
1769 | remap_to_cache_dirty(cache, bio, block, cblock); | |
2ee57d58 | 1770 | } |
c6b4fcba | 1771 | } |
651f5fa2 | 1772 | |
651f5fa2 | 1773 | /* |
b29d4986 | 1774 | * dm core turns FUA requests into a separate payload and FLUSH req. |
651f5fa2 | 1775 | */ |
b29d4986 | 1776 | if (bio->bi_opf & REQ_FUA) { |
651f5fa2 | 1777 | /* |
b29d4986 JT |
1778 | * issue_after_commit will call accounted_begin a second time. So |
1779 | * we call accounted_complete() to avoid double accounting. | |
651f5fa2 | 1780 | */ |
b29d4986 JT |
1781 | accounted_complete(cache, bio); |
1782 | issue_after_commit(&cache->committer, bio); | |
1783 | *commit_needed = true; | |
1784 | return DM_MAPIO_SUBMITTED; | |
651f5fa2 JT |
1785 | } |
1786 | ||
b29d4986 | 1787 | return DM_MAPIO_REMAPPED; |
651f5fa2 JT |
1788 | } |
1789 | ||
b29d4986 | 1790 | static bool process_bio(struct cache *cache, struct bio *bio) |
c6b4fcba | 1791 | { |
b29d4986 | 1792 | bool commit_needed; |
c6b4fcba | 1793 | |
b29d4986 JT |
1794 | if (map_bio(cache, bio, get_bio_block(cache, bio), &commit_needed) == DM_MAPIO_REMAPPED) |
1795 | generic_make_request(bio); | |
c6b4fcba | 1796 | |
b29d4986 | 1797 | return commit_needed; |
c6b4fcba JT |
1798 | } |
1799 | ||
028ae9f7 JT |
1800 | /* |
1801 | * A non-zero return indicates read_only or fail_io mode. | |
1802 | */ | |
1803 | static int commit(struct cache *cache, bool clean_shutdown) | |
e2e74d61 | 1804 | { |
028ae9f7 | 1805 | int r; |
e2e74d61 | 1806 | |
028ae9f7 JT |
1807 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
1808 | return -EINVAL; | |
e2e74d61 | 1809 | |
028ae9f7 JT |
1810 | atomic_inc(&cache->stats.commit_count); |
1811 | r = dm_cache_commit(cache->cmd, clean_shutdown); | |
1812 | if (r) | |
1813 | metadata_operation_failed(cache, "dm_cache_commit", r); | |
e2e74d61 | 1814 | |
028ae9f7 | 1815 | return r; |
e2e74d61 JT |
1816 | } |
1817 | ||
b29d4986 JT |
1818 | /* |
1819 | * Used by the batcher. | |
1820 | */ | |
4e4cbee9 | 1821 | static blk_status_t commit_op(void *context) |
c6b4fcba | 1822 | { |
b29d4986 | 1823 | struct cache *cache = context; |
c6b4fcba | 1824 | |
b29d4986 | 1825 | if (dm_cache_changed_this_transaction(cache->cmd)) |
4e4cbee9 | 1826 | return errno_to_blk_status(commit(cache, false)); |
c6b4fcba | 1827 | |
b29d4986 | 1828 | return 0; |
c6b4fcba JT |
1829 | } |
1830 | ||
b29d4986 | 1831 | /*----------------------------------------------------------------*/ |
65790ff9 | 1832 | |
b29d4986 | 1833 | static bool process_flush_bio(struct cache *cache, struct bio *bio) |
65790ff9 | 1834 | { |
693b960e | 1835 | struct per_bio_data *pb = get_per_bio_data(bio); |
65790ff9 | 1836 | |
b29d4986 JT |
1837 | if (!pb->req_nr) |
1838 | remap_to_origin(cache, bio); | |
1839 | else | |
1840 | remap_to_cache(cache, bio, 0); | |
65790ff9 | 1841 | |
b29d4986 JT |
1842 | issue_after_commit(&cache->committer, bio); |
1843 | return true; | |
65790ff9 JT |
1844 | } |
1845 | ||
b29d4986 | 1846 | static bool process_discard_bio(struct cache *cache, struct bio *bio) |
65790ff9 | 1847 | { |
b29d4986 | 1848 | dm_dblock_t b, e; |
65790ff9 | 1849 | |
b29d4986 JT |
1850 | // FIXME: do we need to lock the region? Or can we just assume the |
1851 | // user wont be so foolish as to issue discard concurrently with | |
1852 | // other IO? | |
1853 | calc_discard_block_range(cache, bio, &b, &e); | |
1854 | while (b != e) { | |
1855 | set_discard(cache, b); | |
1856 | b = to_dblock(from_dblock(b) + 1); | |
651f5fa2 | 1857 | } |
65790ff9 | 1858 | |
de7180ff MS |
1859 | if (cache->features.discard_passdown) { |
1860 | remap_to_origin(cache, bio); | |
1861 | generic_make_request(bio); | |
1862 | } else | |
1863 | bio_endio(bio); | |
65790ff9 | 1864 | |
b29d4986 | 1865 | return false; |
c6b4fcba JT |
1866 | } |
1867 | ||
b29d4986 | 1868 | static void process_deferred_bios(struct work_struct *ws) |
66cb1910 | 1869 | { |
b29d4986 | 1870 | struct cache *cache = container_of(ws, struct cache, deferred_bio_worker); |
66cb1910 | 1871 | |
b29d4986 | 1872 | bool commit_needed = false; |
c6b4fcba JT |
1873 | struct bio_list bios; |
1874 | struct bio *bio; | |
66cb1910 | 1875 | |
c6b4fcba | 1876 | bio_list_init(&bios); |
c6b4fcba | 1877 | |
26b924b9 | 1878 | spin_lock_irq(&cache->lock); |
b29d4986 JT |
1879 | bio_list_merge(&bios, &cache->deferred_bios); |
1880 | bio_list_init(&cache->deferred_bios); | |
26b924b9 | 1881 | spin_unlock_irq(&cache->lock); |
c6b4fcba | 1882 | |
b29d4986 JT |
1883 | while ((bio = bio_list_pop(&bios))) { |
1884 | if (bio->bi_opf & REQ_PREFLUSH) | |
1885 | commit_needed = process_flush_bio(cache, bio) || commit_needed; | |
c6b4fcba | 1886 | |
b29d4986 JT |
1887 | else if (bio_op(bio) == REQ_OP_DISCARD) |
1888 | commit_needed = process_discard_bio(cache, bio) || commit_needed; | |
1889 | ||
1890 | else | |
1891 | commit_needed = process_bio(cache, bio) || commit_needed; | |
1892 | } | |
1893 | ||
1894 | if (commit_needed) | |
1895 | schedule_commit(&cache->committer); | |
c6b4fcba JT |
1896 | } |
1897 | ||
c6b4fcba JT |
1898 | /*---------------------------------------------------------------- |
1899 | * Main worker loop | |
1900 | *--------------------------------------------------------------*/ | |
651f5fa2 JT |
1901 | |
1902 | static void requeue_deferred_bios(struct cache *cache) | |
c6b4fcba JT |
1903 | { |
1904 | struct bio *bio; | |
1905 | struct bio_list bios; | |
1906 | ||
1907 | bio_list_init(&bios); | |
1908 | bio_list_merge(&bios, &cache->deferred_bios); | |
1909 | bio_list_init(&cache->deferred_bios); | |
1910 | ||
4246a0b6 | 1911 | while ((bio = bio_list_pop(&bios))) { |
4e4cbee9 | 1912 | bio->bi_status = BLK_STS_DM_REQUEUE; |
4246a0b6 CH |
1913 | bio_endio(bio); |
1914 | } | |
c6b4fcba JT |
1915 | } |
1916 | ||
c6b4fcba JT |
1917 | /* |
1918 | * We want to commit periodically so that not too much | |
1919 | * unwritten metadata builds up. | |
1920 | */ | |
1921 | static void do_waker(struct work_struct *ws) | |
1922 | { | |
1923 | struct cache *cache = container_of(to_delayed_work(ws), struct cache, waker); | |
b29d4986 | 1924 | |
fba10109 | 1925 | policy_tick(cache->policy, true); |
b29d4986 JT |
1926 | wake_migration_worker(cache); |
1927 | schedule_commit(&cache->committer); | |
c6b4fcba JT |
1928 | queue_delayed_work(cache->wq, &cache->waker, COMMIT_PERIOD); |
1929 | } | |
1930 | ||
b29d4986 | 1931 | static void check_migrations(struct work_struct *ws) |
c6b4fcba | 1932 | { |
b29d4986 JT |
1933 | int r; |
1934 | struct policy_work *op; | |
1935 | struct cache *cache = container_of(ws, struct cache, migration_worker); | |
1936 | enum busy b; | |
c6b4fcba | 1937 | |
b29d4986 JT |
1938 | for (;;) { |
1939 | b = spare_migration_bandwidth(cache); | |
c6b4fcba | 1940 | |
b29d4986 JT |
1941 | r = policy_get_background_work(cache->policy, b == IDLE, &op); |
1942 | if (r == -ENODATA) | |
1943 | break; | |
1944 | ||
1945 | if (r) { | |
1946 | DMERR_LIMIT("%s: policy_background_work failed", | |
1947 | cache_device_name(cache)); | |
1948 | break; | |
1949 | } | |
1950 | ||
1951 | r = mg_start(cache, op, NULL); | |
1952 | if (r) | |
1953 | break; | |
1954 | } | |
c6b4fcba JT |
1955 | } |
1956 | ||
1957 | /*---------------------------------------------------------------- | |
1958 | * Target methods | |
1959 | *--------------------------------------------------------------*/ | |
1960 | ||
1961 | /* | |
1962 | * This function gets called on the error paths of the constructor, so we | |
1963 | * have to cope with a partially initialised struct. | |
1964 | */ | |
1965 | static void destroy(struct cache *cache) | |
1966 | { | |
1967 | unsigned i; | |
1968 | ||
6f1c819c | 1969 | mempool_exit(&cache->migration_pool); |
c6b4fcba | 1970 | |
c6b4fcba | 1971 | if (cache->prison) |
b29d4986 | 1972 | dm_bio_prison_destroy_v2(cache->prison); |
c6b4fcba JT |
1973 | |
1974 | if (cache->wq) | |
1975 | destroy_workqueue(cache->wq); | |
1976 | ||
1977 | if (cache->dirty_bitset) | |
1978 | free_bitset(cache->dirty_bitset); | |
1979 | ||
1980 | if (cache->discard_bitset) | |
1981 | free_bitset(cache->discard_bitset); | |
1982 | ||
1983 | if (cache->copier) | |
1984 | dm_kcopyd_client_destroy(cache->copier); | |
1985 | ||
1986 | if (cache->cmd) | |
1987 | dm_cache_metadata_close(cache->cmd); | |
1988 | ||
1989 | if (cache->metadata_dev) | |
1990 | dm_put_device(cache->ti, cache->metadata_dev); | |
1991 | ||
1992 | if (cache->origin_dev) | |
1993 | dm_put_device(cache->ti, cache->origin_dev); | |
1994 | ||
1995 | if (cache->cache_dev) | |
1996 | dm_put_device(cache->ti, cache->cache_dev); | |
1997 | ||
1998 | if (cache->policy) | |
1999 | dm_cache_policy_destroy(cache->policy); | |
2000 | ||
2001 | for (i = 0; i < cache->nr_ctr_args ; i++) | |
2002 | kfree(cache->ctr_args[i]); | |
2003 | kfree(cache->ctr_args); | |
2004 | ||
6f1c819c | 2005 | bioset_exit(&cache->bs); |
2df3bae9 | 2006 | |
c6b4fcba JT |
2007 | kfree(cache); |
2008 | } | |
2009 | ||
2010 | static void cache_dtr(struct dm_target *ti) | |
2011 | { | |
2012 | struct cache *cache = ti->private; | |
2013 | ||
2014 | destroy(cache); | |
2015 | } | |
2016 | ||
2017 | static sector_t get_dev_size(struct dm_dev *dev) | |
2018 | { | |
2019 | return i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
2020 | } | |
2021 | ||
2022 | /*----------------------------------------------------------------*/ | |
2023 | ||
2024 | /* | |
2025 | * Construct a cache device mapping. | |
2026 | * | |
2027 | * cache <metadata dev> <cache dev> <origin dev> <block size> | |
2028 | * <#feature args> [<feature arg>]* | |
2029 | * <policy> <#policy args> [<policy arg>]* | |
2030 | * | |
2031 | * metadata dev : fast device holding the persistent metadata | |
2032 | * cache dev : fast device holding cached data blocks | |
2033 | * origin dev : slow device holding original data blocks | |
2034 | * block size : cache unit size in sectors | |
2035 | * | |
2036 | * #feature args : number of feature arguments passed | |
2037 | * feature args : writethrough. (The default is writeback.) | |
2038 | * | |
2039 | * policy : the replacement policy to use | |
2040 | * #policy args : an even number of policy arguments corresponding | |
2041 | * to key/value pairs passed to the policy | |
2042 | * policy args : key/value pairs passed to the policy | |
2043 | * E.g. 'sequential_threshold 1024' | |
2044 | * See cache-policies.txt for details. | |
2045 | * | |
2046 | * Optional feature arguments are: | |
2047 | * writethrough : write through caching that prohibits cache block | |
2048 | * content from being different from origin block content. | |
2049 | * Without this argument, the default behaviour is to write | |
2050 | * back cache block contents later for performance reasons, | |
2051 | * so they may differ from the corresponding origin blocks. | |
2052 | */ | |
2053 | struct cache_args { | |
2054 | struct dm_target *ti; | |
2055 | ||
2056 | struct dm_dev *metadata_dev; | |
2057 | ||
2058 | struct dm_dev *cache_dev; | |
2059 | sector_t cache_sectors; | |
2060 | ||
2061 | struct dm_dev *origin_dev; | |
2062 | sector_t origin_sectors; | |
2063 | ||
2064 | uint32_t block_size; | |
2065 | ||
2066 | const char *policy_name; | |
2067 | int policy_argc; | |
2068 | const char **policy_argv; | |
2069 | ||
2070 | struct cache_features features; | |
2071 | }; | |
2072 | ||
2073 | static void destroy_cache_args(struct cache_args *ca) | |
2074 | { | |
2075 | if (ca->metadata_dev) | |
2076 | dm_put_device(ca->ti, ca->metadata_dev); | |
2077 | ||
2078 | if (ca->cache_dev) | |
2079 | dm_put_device(ca->ti, ca->cache_dev); | |
2080 | ||
2081 | if (ca->origin_dev) | |
2082 | dm_put_device(ca->ti, ca->origin_dev); | |
2083 | ||
2084 | kfree(ca); | |
2085 | } | |
2086 | ||
2087 | static bool at_least_one_arg(struct dm_arg_set *as, char **error) | |
2088 | { | |
2089 | if (!as->argc) { | |
2090 | *error = "Insufficient args"; | |
2091 | return false; | |
2092 | } | |
2093 | ||
2094 | return true; | |
2095 | } | |
2096 | ||
2097 | static int parse_metadata_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2098 | char **error) | |
2099 | { | |
2100 | int r; | |
2101 | sector_t metadata_dev_size; | |
2102 | char b[BDEVNAME_SIZE]; | |
2103 | ||
2104 | if (!at_least_one_arg(as, error)) | |
2105 | return -EINVAL; | |
2106 | ||
2107 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2108 | &ca->metadata_dev); | |
2109 | if (r) { | |
2110 | *error = "Error opening metadata device"; | |
2111 | return r; | |
2112 | } | |
2113 | ||
2114 | metadata_dev_size = get_dev_size(ca->metadata_dev); | |
2115 | if (metadata_dev_size > DM_CACHE_METADATA_MAX_SECTORS_WARNING) | |
2116 | DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.", | |
2117 | bdevname(ca->metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS); | |
2118 | ||
2119 | return 0; | |
2120 | } | |
2121 | ||
2122 | static int parse_cache_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2123 | char **error) | |
2124 | { | |
2125 | int r; | |
2126 | ||
2127 | if (!at_least_one_arg(as, error)) | |
2128 | return -EINVAL; | |
2129 | ||
2130 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2131 | &ca->cache_dev); | |
2132 | if (r) { | |
2133 | *error = "Error opening cache device"; | |
2134 | return r; | |
2135 | } | |
2136 | ca->cache_sectors = get_dev_size(ca->cache_dev); | |
2137 | ||
2138 | return 0; | |
2139 | } | |
2140 | ||
2141 | static int parse_origin_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2142 | char **error) | |
2143 | { | |
2144 | int r; | |
2145 | ||
2146 | if (!at_least_one_arg(as, error)) | |
2147 | return -EINVAL; | |
2148 | ||
2149 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2150 | &ca->origin_dev); | |
2151 | if (r) { | |
2152 | *error = "Error opening origin device"; | |
2153 | return r; | |
2154 | } | |
2155 | ||
2156 | ca->origin_sectors = get_dev_size(ca->origin_dev); | |
2157 | if (ca->ti->len > ca->origin_sectors) { | |
2158 | *error = "Device size larger than cached device"; | |
2159 | return -EINVAL; | |
2160 | } | |
2161 | ||
2162 | return 0; | |
2163 | } | |
2164 | ||
2165 | static int parse_block_size(struct cache_args *ca, struct dm_arg_set *as, | |
2166 | char **error) | |
2167 | { | |
05473044 | 2168 | unsigned long block_size; |
c6b4fcba JT |
2169 | |
2170 | if (!at_least_one_arg(as, error)) | |
2171 | return -EINVAL; | |
2172 | ||
05473044 MS |
2173 | if (kstrtoul(dm_shift_arg(as), 10, &block_size) || !block_size || |
2174 | block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS || | |
2175 | block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS || | |
2176 | block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) { | |
c6b4fcba JT |
2177 | *error = "Invalid data block size"; |
2178 | return -EINVAL; | |
2179 | } | |
2180 | ||
05473044 | 2181 | if (block_size > ca->cache_sectors) { |
c6b4fcba JT |
2182 | *error = "Data block size is larger than the cache device"; |
2183 | return -EINVAL; | |
2184 | } | |
2185 | ||
05473044 | 2186 | ca->block_size = block_size; |
c6b4fcba JT |
2187 | |
2188 | return 0; | |
2189 | } | |
2190 | ||
2191 | static void init_features(struct cache_features *cf) | |
2192 | { | |
2193 | cf->mode = CM_WRITE; | |
2ee57d58 | 2194 | cf->io_mode = CM_IO_WRITEBACK; |
629d0a8a | 2195 | cf->metadata_version = 1; |
de7180ff | 2196 | cf->discard_passdown = true; |
c6b4fcba JT |
2197 | } |
2198 | ||
2199 | static int parse_features(struct cache_args *ca, struct dm_arg_set *as, | |
2200 | char **error) | |
2201 | { | |
5916a22b | 2202 | static const struct dm_arg _args[] = { |
de7180ff | 2203 | {0, 3, "Invalid number of cache feature arguments"}, |
c6b4fcba JT |
2204 | }; |
2205 | ||
af9313c3 | 2206 | int r, mode_ctr = 0; |
c6b4fcba JT |
2207 | unsigned argc; |
2208 | const char *arg; | |
2209 | struct cache_features *cf = &ca->features; | |
2210 | ||
2211 | init_features(cf); | |
2212 | ||
2213 | r = dm_read_arg_group(_args, as, &argc, error); | |
2214 | if (r) | |
2215 | return -EINVAL; | |
2216 | ||
2217 | while (argc--) { | |
2218 | arg = dm_shift_arg(as); | |
2219 | ||
af9313c3 | 2220 | if (!strcasecmp(arg, "writeback")) { |
2ee57d58 | 2221 | cf->io_mode = CM_IO_WRITEBACK; |
af9313c3 JP |
2222 | mode_ctr++; |
2223 | } | |
c6b4fcba | 2224 | |
af9313c3 | 2225 | else if (!strcasecmp(arg, "writethrough")) { |
2ee57d58 | 2226 | cf->io_mode = CM_IO_WRITETHROUGH; |
af9313c3 JP |
2227 | mode_ctr++; |
2228 | } | |
2ee57d58 | 2229 | |
af9313c3 | 2230 | else if (!strcasecmp(arg, "passthrough")) { |
2ee57d58 | 2231 | cf->io_mode = CM_IO_PASSTHROUGH; |
af9313c3 JP |
2232 | mode_ctr++; |
2233 | } | |
c6b4fcba | 2234 | |
629d0a8a JT |
2235 | else if (!strcasecmp(arg, "metadata2")) |
2236 | cf->metadata_version = 2; | |
2237 | ||
de7180ff MS |
2238 | else if (!strcasecmp(arg, "no_discard_passdown")) |
2239 | cf->discard_passdown = false; | |
2240 | ||
c6b4fcba JT |
2241 | else { |
2242 | *error = "Unrecognised cache feature requested"; | |
2243 | return -EINVAL; | |
2244 | } | |
2245 | } | |
2246 | ||
af9313c3 JP |
2247 | if (mode_ctr > 1) { |
2248 | *error = "Duplicate cache io_mode features requested"; | |
2249 | return -EINVAL; | |
2250 | } | |
2251 | ||
c6b4fcba JT |
2252 | return 0; |
2253 | } | |
2254 | ||
2255 | static int parse_policy(struct cache_args *ca, struct dm_arg_set *as, | |
2256 | char **error) | |
2257 | { | |
5916a22b | 2258 | static const struct dm_arg _args[] = { |
c6b4fcba JT |
2259 | {0, 1024, "Invalid number of policy arguments"}, |
2260 | }; | |
2261 | ||
2262 | int r; | |
2263 | ||
2264 | if (!at_least_one_arg(as, error)) | |
2265 | return -EINVAL; | |
2266 | ||
2267 | ca->policy_name = dm_shift_arg(as); | |
2268 | ||
2269 | r = dm_read_arg_group(_args, as, &ca->policy_argc, error); | |
2270 | if (r) | |
2271 | return -EINVAL; | |
2272 | ||
2273 | ca->policy_argv = (const char **)as->argv; | |
2274 | dm_consume_args(as, ca->policy_argc); | |
2275 | ||
2276 | return 0; | |
2277 | } | |
2278 | ||
2279 | static int parse_cache_args(struct cache_args *ca, int argc, char **argv, | |
2280 | char **error) | |
2281 | { | |
2282 | int r; | |
2283 | struct dm_arg_set as; | |
2284 | ||
2285 | as.argc = argc; | |
2286 | as.argv = argv; | |
2287 | ||
2288 | r = parse_metadata_dev(ca, &as, error); | |
2289 | if (r) | |
2290 | return r; | |
2291 | ||
2292 | r = parse_cache_dev(ca, &as, error); | |
2293 | if (r) | |
2294 | return r; | |
2295 | ||
2296 | r = parse_origin_dev(ca, &as, error); | |
2297 | if (r) | |
2298 | return r; | |
2299 | ||
2300 | r = parse_block_size(ca, &as, error); | |
2301 | if (r) | |
2302 | return r; | |
2303 | ||
2304 | r = parse_features(ca, &as, error); | |
2305 | if (r) | |
2306 | return r; | |
2307 | ||
2308 | r = parse_policy(ca, &as, error); | |
2309 | if (r) | |
2310 | return r; | |
2311 | ||
2312 | return 0; | |
2313 | } | |
2314 | ||
2315 | /*----------------------------------------------------------------*/ | |
2316 | ||
2317 | static struct kmem_cache *migration_cache; | |
2318 | ||
2c73c471 AK |
2319 | #define NOT_CORE_OPTION 1 |
2320 | ||
2f14f4b5 | 2321 | static int process_config_option(struct cache *cache, const char *key, const char *value) |
2c73c471 AK |
2322 | { |
2323 | unsigned long tmp; | |
2324 | ||
2f14f4b5 JT |
2325 | if (!strcasecmp(key, "migration_threshold")) { |
2326 | if (kstrtoul(value, 10, &tmp)) | |
2c73c471 AK |
2327 | return -EINVAL; |
2328 | ||
2329 | cache->migration_threshold = tmp; | |
2330 | return 0; | |
2331 | } | |
2332 | ||
2333 | return NOT_CORE_OPTION; | |
2334 | } | |
2335 | ||
2f14f4b5 JT |
2336 | static int set_config_value(struct cache *cache, const char *key, const char *value) |
2337 | { | |
2338 | int r = process_config_option(cache, key, value); | |
2339 | ||
2340 | if (r == NOT_CORE_OPTION) | |
2341 | r = policy_set_config_value(cache->policy, key, value); | |
2342 | ||
2343 | if (r) | |
2344 | DMWARN("bad config value for %s: %s", key, value); | |
2345 | ||
2346 | return r; | |
2347 | } | |
2348 | ||
2349 | static int set_config_values(struct cache *cache, int argc, const char **argv) | |
c6b4fcba JT |
2350 | { |
2351 | int r = 0; | |
2352 | ||
2353 | if (argc & 1) { | |
2354 | DMWARN("Odd number of policy arguments given but they should be <key> <value> pairs."); | |
2355 | return -EINVAL; | |
2356 | } | |
2357 | ||
2358 | while (argc) { | |
2f14f4b5 JT |
2359 | r = set_config_value(cache, argv[0], argv[1]); |
2360 | if (r) | |
2361 | break; | |
c6b4fcba JT |
2362 | |
2363 | argc -= 2; | |
2364 | argv += 2; | |
2365 | } | |
2366 | ||
2367 | return r; | |
2368 | } | |
2369 | ||
2370 | static int create_cache_policy(struct cache *cache, struct cache_args *ca, | |
2371 | char **error) | |
2372 | { | |
4cb3e1db MP |
2373 | struct dm_cache_policy *p = dm_cache_policy_create(ca->policy_name, |
2374 | cache->cache_size, | |
2375 | cache->origin_sectors, | |
2376 | cache->sectors_per_block); | |
2377 | if (IS_ERR(p)) { | |
c6b4fcba | 2378 | *error = "Error creating cache's policy"; |
4cb3e1db | 2379 | return PTR_ERR(p); |
c6b4fcba | 2380 | } |
4cb3e1db | 2381 | cache->policy = p; |
b29d4986 | 2382 | BUG_ON(!cache->policy); |
c6b4fcba | 2383 | |
2f14f4b5 | 2384 | return 0; |
c6b4fcba JT |
2385 | } |
2386 | ||
08b18451 | 2387 | /* |
2bb812df JT |
2388 | * We want the discard block size to be at least the size of the cache |
2389 | * block size and have no more than 2^14 discard blocks across the origin. | |
08b18451 JT |
2390 | */ |
2391 | #define MAX_DISCARD_BLOCKS (1 << 14) | |
2392 | ||
2393 | static bool too_many_discard_blocks(sector_t discard_block_size, | |
2394 | sector_t origin_size) | |
2395 | { | |
2396 | (void) sector_div(origin_size, discard_block_size); | |
2397 | ||
2398 | return origin_size > MAX_DISCARD_BLOCKS; | |
2399 | } | |
2400 | ||
2401 | static sector_t calculate_discard_block_size(sector_t cache_block_size, | |
2402 | sector_t origin_size) | |
2403 | { | |
2bb812df | 2404 | sector_t discard_block_size = cache_block_size; |
08b18451 JT |
2405 | |
2406 | if (origin_size) | |
2407 | while (too_many_discard_blocks(discard_block_size, origin_size)) | |
2408 | discard_block_size *= 2; | |
2409 | ||
2410 | return discard_block_size; | |
2411 | } | |
2412 | ||
d1d9220c JT |
2413 | static void set_cache_size(struct cache *cache, dm_cblock_t size) |
2414 | { | |
2415 | dm_block_t nr_blocks = from_cblock(size); | |
2416 | ||
2417 | if (nr_blocks > (1 << 20) && cache->cache_size != size) | |
2418 | DMWARN_LIMIT("You have created a cache device with a lot of individual cache blocks (%llu)\n" | |
2419 | "All these mappings can consume a lot of kernel memory, and take some time to read/write.\n" | |
2420 | "Please consider increasing the cache block size to reduce the overall cache block count.", | |
2421 | (unsigned long long) nr_blocks); | |
2422 | ||
2423 | cache->cache_size = size; | |
2424 | } | |
2425 | ||
b29d4986 JT |
2426 | static int is_congested(struct dm_dev *dev, int bdi_bits) |
2427 | { | |
2428 | struct request_queue *q = bdev_get_queue(dev->bdev); | |
2429 | return bdi_congested(q->backing_dev_info, bdi_bits); | |
2430 | } | |
2431 | ||
2432 | static int cache_is_congested(struct dm_target_callbacks *cb, int bdi_bits) | |
2433 | { | |
2434 | struct cache *cache = container_of(cb, struct cache, callbacks); | |
2435 | ||
2436 | return is_congested(cache->origin_dev, bdi_bits) || | |
2437 | is_congested(cache->cache_dev, bdi_bits); | |
2438 | } | |
2439 | ||
f8350daf | 2440 | #define DEFAULT_MIGRATION_THRESHOLD 2048 |
c6b4fcba | 2441 | |
c6b4fcba JT |
2442 | static int cache_create(struct cache_args *ca, struct cache **result) |
2443 | { | |
2444 | int r = 0; | |
2445 | char **error = &ca->ti->error; | |
2446 | struct cache *cache; | |
2447 | struct dm_target *ti = ca->ti; | |
2448 | dm_block_t origin_blocks; | |
2449 | struct dm_cache_metadata *cmd; | |
2450 | bool may_format = ca->features.mode == CM_WRITE; | |
2451 | ||
2452 | cache = kzalloc(sizeof(*cache), GFP_KERNEL); | |
2453 | if (!cache) | |
2454 | return -ENOMEM; | |
2455 | ||
2456 | cache->ti = ca->ti; | |
2457 | ti->private = cache; | |
c6b4fcba JT |
2458 | ti->num_flush_bios = 2; |
2459 | ti->flush_supported = true; | |
2460 | ||
2461 | ti->num_discard_bios = 1; | |
2462 | ti->discards_supported = true; | |
c6b4fcba | 2463 | |
693b960e | 2464 | ti->per_io_data_size = sizeof(struct per_bio_data); |
c6b4fcba | 2465 | |
693b960e | 2466 | cache->features = ca->features; |
2df3bae9 MS |
2467 | if (writethrough_mode(cache)) { |
2468 | /* Create bioset for writethrough bios issued to origin */ | |
6f1c819c KO |
2469 | r = bioset_init(&cache->bs, BIO_POOL_SIZE, 0, 0); |
2470 | if (r) | |
2df3bae9 MS |
2471 | goto bad; |
2472 | } | |
2473 | ||
c6b4fcba JT |
2474 | cache->callbacks.congested_fn = cache_is_congested; |
2475 | dm_table_add_target_callbacks(ti->table, &cache->callbacks); | |
2476 | ||
2477 | cache->metadata_dev = ca->metadata_dev; | |
2478 | cache->origin_dev = ca->origin_dev; | |
2479 | cache->cache_dev = ca->cache_dev; | |
2480 | ||
2481 | ca->metadata_dev = ca->origin_dev = ca->cache_dev = NULL; | |
2482 | ||
c6b4fcba | 2483 | origin_blocks = cache->origin_sectors = ca->origin_sectors; |
414dd67d | 2484 | origin_blocks = block_div(origin_blocks, ca->block_size); |
c6b4fcba JT |
2485 | cache->origin_blocks = to_oblock(origin_blocks); |
2486 | ||
2487 | cache->sectors_per_block = ca->block_size; | |
2488 | if (dm_set_target_max_io_len(ti, cache->sectors_per_block)) { | |
2489 | r = -EINVAL; | |
2490 | goto bad; | |
2491 | } | |
2492 | ||
2493 | if (ca->block_size & (ca->block_size - 1)) { | |
2494 | dm_block_t cache_size = ca->cache_sectors; | |
2495 | ||
2496 | cache->sectors_per_block_shift = -1; | |
414dd67d | 2497 | cache_size = block_div(cache_size, ca->block_size); |
d1d9220c | 2498 | set_cache_size(cache, to_cblock(cache_size)); |
c6b4fcba JT |
2499 | } else { |
2500 | cache->sectors_per_block_shift = __ffs(ca->block_size); | |
d1d9220c | 2501 | set_cache_size(cache, to_cblock(ca->cache_sectors >> cache->sectors_per_block_shift)); |
c6b4fcba JT |
2502 | } |
2503 | ||
2504 | r = create_cache_policy(cache, ca, error); | |
2505 | if (r) | |
2506 | goto bad; | |
2f14f4b5 | 2507 | |
c6b4fcba | 2508 | cache->policy_nr_args = ca->policy_argc; |
2f14f4b5 JT |
2509 | cache->migration_threshold = DEFAULT_MIGRATION_THRESHOLD; |
2510 | ||
2511 | r = set_config_values(cache, ca->policy_argc, ca->policy_argv); | |
2512 | if (r) { | |
2513 | *error = "Error setting cache policy's config values"; | |
2514 | goto bad; | |
2515 | } | |
c6b4fcba JT |
2516 | |
2517 | cmd = dm_cache_metadata_open(cache->metadata_dev->bdev, | |
2518 | ca->block_size, may_format, | |
629d0a8a JT |
2519 | dm_cache_policy_get_hint_size(cache->policy), |
2520 | ca->features.metadata_version); | |
c6b4fcba JT |
2521 | if (IS_ERR(cmd)) { |
2522 | *error = "Error creating metadata object"; | |
2523 | r = PTR_ERR(cmd); | |
2524 | goto bad; | |
2525 | } | |
2526 | cache->cmd = cmd; | |
028ae9f7 JT |
2527 | set_cache_mode(cache, CM_WRITE); |
2528 | if (get_cache_mode(cache) != CM_WRITE) { | |
2529 | *error = "Unable to get write access to metadata, please check/repair metadata."; | |
2530 | r = -EINVAL; | |
2531 | goto bad; | |
2532 | } | |
c6b4fcba | 2533 | |
8e3c3827 | 2534 | if (passthrough_mode(cache)) { |
2ee57d58 JT |
2535 | bool all_clean; |
2536 | ||
2537 | r = dm_cache_metadata_all_clean(cache->cmd, &all_clean); | |
2538 | if (r) { | |
2539 | *error = "dm_cache_metadata_all_clean() failed"; | |
2540 | goto bad; | |
2541 | } | |
2542 | ||
2543 | if (!all_clean) { | |
2544 | *error = "Cannot enter passthrough mode unless all blocks are clean"; | |
2545 | r = -EINVAL; | |
2546 | goto bad; | |
2547 | } | |
b29d4986 JT |
2548 | |
2549 | policy_allow_migrations(cache->policy, false); | |
2ee57d58 JT |
2550 | } |
2551 | ||
c6b4fcba JT |
2552 | spin_lock_init(&cache->lock); |
2553 | bio_list_init(&cache->deferred_bios); | |
a59db676 JT |
2554 | atomic_set(&cache->nr_allocated_migrations, 0); |
2555 | atomic_set(&cache->nr_io_migrations, 0); | |
c6b4fcba JT |
2556 | init_waitqueue_head(&cache->migration_wait); |
2557 | ||
fa4d683a | 2558 | r = -ENOMEM; |
44fa816b | 2559 | atomic_set(&cache->nr_dirty, 0); |
c6b4fcba JT |
2560 | cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size)); |
2561 | if (!cache->dirty_bitset) { | |
2562 | *error = "could not allocate dirty bitset"; | |
2563 | goto bad; | |
2564 | } | |
2565 | clear_bitset(cache->dirty_bitset, from_cblock(cache->cache_size)); | |
2566 | ||
08b18451 JT |
2567 | cache->discard_block_size = |
2568 | calculate_discard_block_size(cache->sectors_per_block, | |
2569 | cache->origin_sectors); | |
2572629a JT |
2570 | cache->discard_nr_blocks = to_dblock(dm_sector_div_up(cache->origin_sectors, |
2571 | cache->discard_block_size)); | |
1bad9bc4 | 2572 | cache->discard_bitset = alloc_bitset(from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2573 | if (!cache->discard_bitset) { |
2574 | *error = "could not allocate discard bitset"; | |
2575 | goto bad; | |
2576 | } | |
1bad9bc4 | 2577 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2578 | |
2579 | cache->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle); | |
2580 | if (IS_ERR(cache->copier)) { | |
2581 | *error = "could not create kcopyd client"; | |
2582 | r = PTR_ERR(cache->copier); | |
2583 | goto bad; | |
2584 | } | |
2585 | ||
b29d4986 | 2586 | cache->wq = alloc_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM, 0); |
c6b4fcba JT |
2587 | if (!cache->wq) { |
2588 | *error = "could not create workqueue for metadata object"; | |
2589 | goto bad; | |
2590 | } | |
b29d4986 | 2591 | INIT_WORK(&cache->deferred_bio_worker, process_deferred_bios); |
b29d4986 | 2592 | INIT_WORK(&cache->migration_worker, check_migrations); |
c6b4fcba | 2593 | INIT_DELAYED_WORK(&cache->waker, do_waker); |
c6b4fcba | 2594 | |
b29d4986 | 2595 | cache->prison = dm_bio_prison_create_v2(cache->wq); |
c6b4fcba JT |
2596 | if (!cache->prison) { |
2597 | *error = "could not create bio prison"; | |
2598 | goto bad; | |
2599 | } | |
2600 | ||
6f1c819c KO |
2601 | r = mempool_init_slab_pool(&cache->migration_pool, MIGRATION_POOL_SIZE, |
2602 | migration_cache); | |
2603 | if (r) { | |
c6b4fcba JT |
2604 | *error = "Error creating cache's migration mempool"; |
2605 | goto bad; | |
2606 | } | |
2607 | ||
c6b4fcba JT |
2608 | cache->need_tick_bio = true; |
2609 | cache->sized = false; | |
65790ff9 | 2610 | cache->invalidate = false; |
c6b4fcba JT |
2611 | cache->commit_requested = false; |
2612 | cache->loaded_mappings = false; | |
2613 | cache->loaded_discards = false; | |
2614 | ||
2615 | load_stats(cache); | |
2616 | ||
2617 | atomic_set(&cache->stats.demotion, 0); | |
2618 | atomic_set(&cache->stats.promotion, 0); | |
2619 | atomic_set(&cache->stats.copies_avoided, 0); | |
2620 | atomic_set(&cache->stats.cache_cell_clash, 0); | |
2621 | atomic_set(&cache->stats.commit_count, 0); | |
2622 | atomic_set(&cache->stats.discard_count, 0); | |
2623 | ||
65790ff9 JT |
2624 | spin_lock_init(&cache->invalidation_lock); |
2625 | INIT_LIST_HEAD(&cache->invalidation_requests); | |
2626 | ||
b29d4986 JT |
2627 | batcher_init(&cache->committer, commit_op, cache, |
2628 | issue_op, cache, cache->wq); | |
701e03e4 | 2629 | iot_init(&cache->tracker); |
066dbaa3 | 2630 | |
b29d4986 JT |
2631 | init_rwsem(&cache->background_work_lock); |
2632 | prevent_background_work(cache); | |
2633 | ||
c6b4fcba JT |
2634 | *result = cache; |
2635 | return 0; | |
c6b4fcba JT |
2636 | bad: |
2637 | destroy(cache); | |
2638 | return r; | |
2639 | } | |
2640 | ||
2641 | static int copy_ctr_args(struct cache *cache, int argc, const char **argv) | |
2642 | { | |
2643 | unsigned i; | |
2644 | const char **copy; | |
2645 | ||
2646 | copy = kcalloc(argc, sizeof(*copy), GFP_KERNEL); | |
2647 | if (!copy) | |
2648 | return -ENOMEM; | |
2649 | for (i = 0; i < argc; i++) { | |
2650 | copy[i] = kstrdup(argv[i], GFP_KERNEL); | |
2651 | if (!copy[i]) { | |
2652 | while (i--) | |
2653 | kfree(copy[i]); | |
2654 | kfree(copy); | |
2655 | return -ENOMEM; | |
2656 | } | |
2657 | } | |
2658 | ||
2659 | cache->nr_ctr_args = argc; | |
2660 | cache->ctr_args = copy; | |
2661 | ||
2662 | return 0; | |
2663 | } | |
2664 | ||
2665 | static int cache_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
2666 | { | |
2667 | int r = -EINVAL; | |
2668 | struct cache_args *ca; | |
2669 | struct cache *cache = NULL; | |
2670 | ||
2671 | ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
2672 | if (!ca) { | |
2673 | ti->error = "Error allocating memory for cache"; | |
2674 | return -ENOMEM; | |
2675 | } | |
2676 | ca->ti = ti; | |
2677 | ||
2678 | r = parse_cache_args(ca, argc, argv, &ti->error); | |
2679 | if (r) | |
2680 | goto out; | |
2681 | ||
2682 | r = cache_create(ca, &cache); | |
617a0b89 HM |
2683 | if (r) |
2684 | goto out; | |
c6b4fcba JT |
2685 | |
2686 | r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3); | |
2687 | if (r) { | |
2688 | destroy(cache); | |
2689 | goto out; | |
2690 | } | |
2691 | ||
2692 | ti->private = cache; | |
c6b4fcba JT |
2693 | out: |
2694 | destroy_cache_args(ca); | |
2695 | return r; | |
2696 | } | |
2697 | ||
651f5fa2 JT |
2698 | /*----------------------------------------------------------------*/ |
2699 | ||
2700 | static int cache_map(struct dm_target *ti, struct bio *bio) | |
c6b4fcba | 2701 | { |
651f5fa2 JT |
2702 | struct cache *cache = ti->private; |
2703 | ||
c6b4fcba | 2704 | int r; |
b29d4986 | 2705 | bool commit_needed; |
c6b4fcba | 2706 | dm_oblock_t block = get_bio_block(cache, bio); |
c6b4fcba | 2707 | |
693b960e | 2708 | init_per_bio_data(bio); |
e893fba9 | 2709 | if (unlikely(from_oblock(block) >= from_oblock(cache->origin_blocks))) { |
c6b4fcba JT |
2710 | /* |
2711 | * This can only occur if the io goes to a partial block at | |
2712 | * the end of the origin device. We don't cache these. | |
2713 | * Just remap to the origin and carry on. | |
2714 | */ | |
e893fba9 | 2715 | remap_to_origin(cache, bio); |
651f5fa2 | 2716 | accounted_begin(cache, bio); |
c6b4fcba JT |
2717 | return DM_MAPIO_REMAPPED; |
2718 | } | |
2719 | ||
651f5fa2 | 2720 | if (discard_or_flush(bio)) { |
c6b4fcba JT |
2721 | defer_bio(cache, bio); |
2722 | return DM_MAPIO_SUBMITTED; | |
2723 | } | |
2724 | ||
b29d4986 JT |
2725 | r = map_bio(cache, bio, block, &commit_needed); |
2726 | if (commit_needed) | |
2727 | schedule_commit(&cache->committer); | |
c6b4fcba | 2728 | |
2ee57d58 | 2729 | return r; |
c6b4fcba JT |
2730 | } |
2731 | ||
693b960e | 2732 | static int cache_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *error) |
c6b4fcba JT |
2733 | { |
2734 | struct cache *cache = ti->private; | |
2735 | unsigned long flags; | |
693b960e | 2736 | struct per_bio_data *pb = get_per_bio_data(bio); |
c6b4fcba JT |
2737 | |
2738 | if (pb->tick) { | |
fba10109 | 2739 | policy_tick(cache->policy, false); |
c6b4fcba JT |
2740 | |
2741 | spin_lock_irqsave(&cache->lock, flags); | |
2742 | cache->need_tick_bio = true; | |
2743 | spin_unlock_irqrestore(&cache->lock, flags); | |
2744 | } | |
2745 | ||
b29d4986 | 2746 | bio_drop_shared_lock(cache, bio); |
066dbaa3 | 2747 | accounted_complete(cache, bio); |
c6b4fcba | 2748 | |
1be56909 | 2749 | return DM_ENDIO_DONE; |
c6b4fcba JT |
2750 | } |
2751 | ||
2752 | static int write_dirty_bitset(struct cache *cache) | |
2753 | { | |
629d0a8a | 2754 | int r; |
c6b4fcba | 2755 | |
028ae9f7 JT |
2756 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
2757 | return -EINVAL; | |
2758 | ||
629d0a8a JT |
2759 | r = dm_cache_set_dirty_bits(cache->cmd, from_cblock(cache->cache_size), cache->dirty_bitset); |
2760 | if (r) | |
2761 | metadata_operation_failed(cache, "dm_cache_set_dirty_bits", r); | |
c6b4fcba | 2762 | |
629d0a8a | 2763 | return r; |
c6b4fcba JT |
2764 | } |
2765 | ||
2766 | static int write_discard_bitset(struct cache *cache) | |
2767 | { | |
2768 | unsigned i, r; | |
2769 | ||
028ae9f7 JT |
2770 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
2771 | return -EINVAL; | |
2772 | ||
1bad9bc4 JT |
2773 | r = dm_cache_discard_bitset_resize(cache->cmd, cache->discard_block_size, |
2774 | cache->discard_nr_blocks); | |
c6b4fcba | 2775 | if (r) { |
b61d9509 | 2776 | DMERR("%s: could not resize on-disk discard bitset", cache_device_name(cache)); |
028ae9f7 | 2777 | metadata_operation_failed(cache, "dm_cache_discard_bitset_resize", r); |
c6b4fcba JT |
2778 | return r; |
2779 | } | |
2780 | ||
1bad9bc4 JT |
2781 | for (i = 0; i < from_dblock(cache->discard_nr_blocks); i++) { |
2782 | r = dm_cache_set_discard(cache->cmd, to_dblock(i), | |
2783 | is_discarded(cache, to_dblock(i))); | |
028ae9f7 JT |
2784 | if (r) { |
2785 | metadata_operation_failed(cache, "dm_cache_set_discard", r); | |
c6b4fcba | 2786 | return r; |
028ae9f7 JT |
2787 | } |
2788 | } | |
2789 | ||
2790 | return 0; | |
2791 | } | |
2792 | ||
2793 | static int write_hints(struct cache *cache) | |
2794 | { | |
2795 | int r; | |
2796 | ||
2797 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
2798 | return -EINVAL; | |
2799 | ||
2800 | r = dm_cache_write_hints(cache->cmd, cache->policy); | |
2801 | if (r) { | |
2802 | metadata_operation_failed(cache, "dm_cache_write_hints", r); | |
2803 | return r; | |
c6b4fcba JT |
2804 | } |
2805 | ||
2806 | return 0; | |
2807 | } | |
2808 | ||
c6b4fcba JT |
2809 | /* |
2810 | * returns true on success | |
2811 | */ | |
2812 | static bool sync_metadata(struct cache *cache) | |
2813 | { | |
2814 | int r1, r2, r3, r4; | |
2815 | ||
2816 | r1 = write_dirty_bitset(cache); | |
2817 | if (r1) | |
b61d9509 | 2818 | DMERR("%s: could not write dirty bitset", cache_device_name(cache)); |
c6b4fcba JT |
2819 | |
2820 | r2 = write_discard_bitset(cache); | |
2821 | if (r2) | |
b61d9509 | 2822 | DMERR("%s: could not write discard bitset", cache_device_name(cache)); |
c6b4fcba JT |
2823 | |
2824 | save_stats(cache); | |
2825 | ||
028ae9f7 | 2826 | r3 = write_hints(cache); |
c6b4fcba | 2827 | if (r3) |
b61d9509 | 2828 | DMERR("%s: could not write hints", cache_device_name(cache)); |
c6b4fcba JT |
2829 | |
2830 | /* | |
2831 | * If writing the above metadata failed, we still commit, but don't | |
2832 | * set the clean shutdown flag. This will effectively force every | |
2833 | * dirty bit to be set on reload. | |
2834 | */ | |
028ae9f7 | 2835 | r4 = commit(cache, !r1 && !r2 && !r3); |
c6b4fcba | 2836 | if (r4) |
b61d9509 | 2837 | DMERR("%s: could not write cache metadata", cache_device_name(cache)); |
c6b4fcba JT |
2838 | |
2839 | return !r1 && !r2 && !r3 && !r4; | |
2840 | } | |
2841 | ||
2842 | static void cache_postsuspend(struct dm_target *ti) | |
2843 | { | |
2844 | struct cache *cache = ti->private; | |
2845 | ||
b29d4986 JT |
2846 | prevent_background_work(cache); |
2847 | BUG_ON(atomic_read(&cache->nr_io_migrations)); | |
2848 | ||
7cdf6a0a MP |
2849 | cancel_delayed_work_sync(&cache->waker); |
2850 | drain_workqueue(cache->wq); | |
701e03e4 | 2851 | WARN_ON(cache->tracker.in_flight); |
b29d4986 JT |
2852 | |
2853 | /* | |
2854 | * If it's a flush suspend there won't be any deferred bios, so this | |
2855 | * call is harmless. | |
2856 | */ | |
651f5fa2 | 2857 | requeue_deferred_bios(cache); |
c6b4fcba | 2858 | |
028ae9f7 JT |
2859 | if (get_cache_mode(cache) == CM_WRITE) |
2860 | (void) sync_metadata(cache); | |
c6b4fcba JT |
2861 | } |
2862 | ||
2863 | static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock, | |
2864 | bool dirty, uint32_t hint, bool hint_valid) | |
2865 | { | |
2866 | int r; | |
2867 | struct cache *cache = context; | |
2868 | ||
449b668c JT |
2869 | if (dirty) { |
2870 | set_bit(from_cblock(cblock), cache->dirty_bitset); | |
2871 | atomic_inc(&cache->nr_dirty); | |
2872 | } else | |
2873 | clear_bit(from_cblock(cblock), cache->dirty_bitset); | |
2874 | ||
b29d4986 | 2875 | r = policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid); |
c6b4fcba JT |
2876 | if (r) |
2877 | return r; | |
2878 | ||
c6b4fcba JT |
2879 | return 0; |
2880 | } | |
2881 | ||
3e2e1c30 JT |
2882 | /* |
2883 | * The discard block size in the on disk metadata is not | |
2884 | * neccessarily the same as we're currently using. So we have to | |
2885 | * be careful to only set the discarded attribute if we know it | |
2886 | * covers a complete block of the new size. | |
2887 | */ | |
2888 | struct discard_load_info { | |
2889 | struct cache *cache; | |
2890 | ||
2891 | /* | |
2892 | * These blocks are sized using the on disk dblock size, rather | |
2893 | * than the current one. | |
2894 | */ | |
2895 | dm_block_t block_size; | |
2896 | dm_block_t discard_begin, discard_end; | |
2897 | }; | |
2898 | ||
2899 | static void discard_load_info_init(struct cache *cache, | |
2900 | struct discard_load_info *li) | |
2901 | { | |
2902 | li->cache = cache; | |
2903 | li->discard_begin = li->discard_end = 0; | |
2904 | } | |
2905 | ||
2906 | static void set_discard_range(struct discard_load_info *li) | |
2907 | { | |
2908 | sector_t b, e; | |
2909 | ||
2910 | if (li->discard_begin == li->discard_end) | |
2911 | return; | |
2912 | ||
2913 | /* | |
2914 | * Convert to sectors. | |
2915 | */ | |
2916 | b = li->discard_begin * li->block_size; | |
2917 | e = li->discard_end * li->block_size; | |
2918 | ||
2919 | /* | |
2920 | * Then convert back to the current dblock size. | |
2921 | */ | |
2922 | b = dm_sector_div_up(b, li->cache->discard_block_size); | |
2923 | sector_div(e, li->cache->discard_block_size); | |
2924 | ||
2925 | /* | |
2926 | * The origin may have shrunk, so we need to check we're still in | |
2927 | * bounds. | |
2928 | */ | |
2929 | if (e > from_dblock(li->cache->discard_nr_blocks)) | |
2930 | e = from_dblock(li->cache->discard_nr_blocks); | |
2931 | ||
2932 | for (; b < e; b++) | |
2933 | set_discard(li->cache, to_dblock(b)); | |
2934 | } | |
2935 | ||
c6b4fcba | 2936 | static int load_discard(void *context, sector_t discard_block_size, |
1bad9bc4 | 2937 | dm_dblock_t dblock, bool discard) |
c6b4fcba | 2938 | { |
3e2e1c30 | 2939 | struct discard_load_info *li = context; |
c6b4fcba | 2940 | |
3e2e1c30 | 2941 | li->block_size = discard_block_size; |
1bad9bc4 | 2942 | |
3e2e1c30 JT |
2943 | if (discard) { |
2944 | if (from_dblock(dblock) == li->discard_end) | |
2945 | /* | |
2946 | * We're already in a discard range, just extend it. | |
2947 | */ | |
2948 | li->discard_end = li->discard_end + 1ULL; | |
2949 | ||
2950 | else { | |
2951 | /* | |
2952 | * Emit the old range and start a new one. | |
2953 | */ | |
2954 | set_discard_range(li); | |
2955 | li->discard_begin = from_dblock(dblock); | |
2956 | li->discard_end = li->discard_begin + 1ULL; | |
2957 | } | |
2958 | } else { | |
2959 | set_discard_range(li); | |
2960 | li->discard_begin = li->discard_end = 0; | |
2961 | } | |
c6b4fcba JT |
2962 | |
2963 | return 0; | |
2964 | } | |
2965 | ||
f494a9c6 JT |
2966 | static dm_cblock_t get_cache_dev_size(struct cache *cache) |
2967 | { | |
2968 | sector_t size = get_dev_size(cache->cache_dev); | |
2969 | (void) sector_div(size, cache->sectors_per_block); | |
2970 | return to_cblock(size); | |
2971 | } | |
2972 | ||
2973 | static bool can_resize(struct cache *cache, dm_cblock_t new_size) | |
2974 | { | |
5d07384a MS |
2975 | if (from_cblock(new_size) > from_cblock(cache->cache_size)) { |
2976 | if (cache->sized) { | |
2977 | DMERR("%s: unable to extend cache due to missing cache table reload", | |
2978 | cache_device_name(cache)); | |
2979 | return false; | |
2980 | } | |
2981 | } | |
f494a9c6 JT |
2982 | |
2983 | /* | |
2984 | * We can't drop a dirty block when shrinking the cache. | |
2985 | */ | |
2986 | while (from_cblock(new_size) < from_cblock(cache->cache_size)) { | |
2987 | new_size = to_cblock(from_cblock(new_size) + 1); | |
2988 | if (is_dirty(cache, new_size)) { | |
b61d9509 MS |
2989 | DMERR("%s: unable to shrink cache; cache block %llu is dirty", |
2990 | cache_device_name(cache), | |
f494a9c6 JT |
2991 | (unsigned long long) from_cblock(new_size)); |
2992 | return false; | |
2993 | } | |
2994 | } | |
2995 | ||
2996 | return true; | |
2997 | } | |
2998 | ||
2999 | static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size) | |
3000 | { | |
3001 | int r; | |
3002 | ||
08844800 | 3003 | r = dm_cache_resize(cache->cmd, new_size); |
f494a9c6 | 3004 | if (r) { |
b61d9509 | 3005 | DMERR("%s: could not resize cache metadata", cache_device_name(cache)); |
028ae9f7 | 3006 | metadata_operation_failed(cache, "dm_cache_resize", r); |
f494a9c6 JT |
3007 | return r; |
3008 | } | |
3009 | ||
d1d9220c | 3010 | set_cache_size(cache, new_size); |
f494a9c6 JT |
3011 | |
3012 | return 0; | |
3013 | } | |
3014 | ||
c6b4fcba JT |
3015 | static int cache_preresume(struct dm_target *ti) |
3016 | { | |
3017 | int r = 0; | |
3018 | struct cache *cache = ti->private; | |
f494a9c6 | 3019 | dm_cblock_t csize = get_cache_dev_size(cache); |
c6b4fcba JT |
3020 | |
3021 | /* | |
3022 | * Check to see if the cache has resized. | |
3023 | */ | |
f494a9c6 JT |
3024 | if (!cache->sized) { |
3025 | r = resize_cache_dev(cache, csize); | |
3026 | if (r) | |
c6b4fcba | 3027 | return r; |
c6b4fcba JT |
3028 | |
3029 | cache->sized = true; | |
f494a9c6 JT |
3030 | |
3031 | } else if (csize != cache->cache_size) { | |
3032 | if (!can_resize(cache, csize)) | |
3033 | return -EINVAL; | |
3034 | ||
3035 | r = resize_cache_dev(cache, csize); | |
3036 | if (r) | |
3037 | return r; | |
c6b4fcba JT |
3038 | } |
3039 | ||
3040 | if (!cache->loaded_mappings) { | |
ea2dd8c1 | 3041 | r = dm_cache_load_mappings(cache->cmd, cache->policy, |
c6b4fcba JT |
3042 | load_mapping, cache); |
3043 | if (r) { | |
b61d9509 | 3044 | DMERR("%s: could not load cache mappings", cache_device_name(cache)); |
028ae9f7 | 3045 | metadata_operation_failed(cache, "dm_cache_load_mappings", r); |
c6b4fcba JT |
3046 | return r; |
3047 | } | |
3048 | ||
3049 | cache->loaded_mappings = true; | |
3050 | } | |
3051 | ||
3052 | if (!cache->loaded_discards) { | |
3e2e1c30 JT |
3053 | struct discard_load_info li; |
3054 | ||
3055 | /* | |
3056 | * The discard bitset could have been resized, or the | |
3057 | * discard block size changed. To be safe we start by | |
3058 | * setting every dblock to not discarded. | |
3059 | */ | |
3060 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); | |
3061 | ||
3062 | discard_load_info_init(cache, &li); | |
3063 | r = dm_cache_load_discards(cache->cmd, load_discard, &li); | |
c6b4fcba | 3064 | if (r) { |
b61d9509 | 3065 | DMERR("%s: could not load origin discards", cache_device_name(cache)); |
028ae9f7 | 3066 | metadata_operation_failed(cache, "dm_cache_load_discards", r); |
c6b4fcba JT |
3067 | return r; |
3068 | } | |
3e2e1c30 | 3069 | set_discard_range(&li); |
c6b4fcba JT |
3070 | |
3071 | cache->loaded_discards = true; | |
3072 | } | |
3073 | ||
3074 | return r; | |
3075 | } | |
3076 | ||
3077 | static void cache_resume(struct dm_target *ti) | |
3078 | { | |
3079 | struct cache *cache = ti->private; | |
3080 | ||
3081 | cache->need_tick_bio = true; | |
b29d4986 | 3082 | allow_background_work(cache); |
c6b4fcba JT |
3083 | do_waker(&cache->waker.work); |
3084 | } | |
3085 | ||
de7180ff MS |
3086 | static void emit_flags(struct cache *cache, char *result, |
3087 | unsigned maxlen, ssize_t *sz_ptr) | |
3088 | { | |
3089 | ssize_t sz = *sz_ptr; | |
3090 | struct cache_features *cf = &cache->features; | |
3091 | unsigned count = (cf->metadata_version == 2) + !cf->discard_passdown + 1; | |
3092 | ||
3093 | DMEMIT("%u ", count); | |
3094 | ||
3095 | if (cf->metadata_version == 2) | |
3096 | DMEMIT("metadata2 "); | |
3097 | ||
3098 | if (writethrough_mode(cache)) | |
3099 | DMEMIT("writethrough "); | |
3100 | ||
3101 | else if (passthrough_mode(cache)) | |
3102 | DMEMIT("passthrough "); | |
3103 | ||
3104 | else if (writeback_mode(cache)) | |
3105 | DMEMIT("writeback "); | |
3106 | ||
3107 | else { | |
3108 | DMEMIT("unknown "); | |
3109 | DMERR("%s: internal error: unknown io mode: %d", | |
3110 | cache_device_name(cache), (int) cf->io_mode); | |
3111 | } | |
3112 | ||
3113 | if (!cf->discard_passdown) | |
3114 | DMEMIT("no_discard_passdown "); | |
3115 | ||
3116 | *sz_ptr = sz; | |
3117 | } | |
3118 | ||
c6b4fcba JT |
3119 | /* |
3120 | * Status format: | |
3121 | * | |
6a388618 MS |
3122 | * <metadata block size> <#used metadata blocks>/<#total metadata blocks> |
3123 | * <cache block size> <#used cache blocks>/<#total cache blocks> | |
c6b4fcba | 3124 | * <#read hits> <#read misses> <#write hits> <#write misses> |
6a388618 | 3125 | * <#demotions> <#promotions> <#dirty> |
c6b4fcba JT |
3126 | * <#features> <features>* |
3127 | * <#core args> <core args> | |
255eac20 | 3128 | * <policy name> <#policy args> <policy args>* <cache metadata mode> <needs_check> |
c6b4fcba JT |
3129 | */ |
3130 | static void cache_status(struct dm_target *ti, status_type_t type, | |
3131 | unsigned status_flags, char *result, unsigned maxlen) | |
3132 | { | |
3133 | int r = 0; | |
3134 | unsigned i; | |
3135 | ssize_t sz = 0; | |
3136 | dm_block_t nr_free_blocks_metadata = 0; | |
3137 | dm_block_t nr_blocks_metadata = 0; | |
3138 | char buf[BDEVNAME_SIZE]; | |
3139 | struct cache *cache = ti->private; | |
3140 | dm_cblock_t residency; | |
d14fcf3d | 3141 | bool needs_check; |
c6b4fcba JT |
3142 | |
3143 | switch (type) { | |
3144 | case STATUSTYPE_INFO: | |
028ae9f7 JT |
3145 | if (get_cache_mode(cache) == CM_FAIL) { |
3146 | DMEMIT("Fail"); | |
3147 | break; | |
c6b4fcba JT |
3148 | } |
3149 | ||
028ae9f7 JT |
3150 | /* Commit to ensure statistics aren't out-of-date */ |
3151 | if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) | |
3152 | (void) commit(cache, false); | |
3153 | ||
b61d9509 | 3154 | r = dm_cache_get_free_metadata_block_count(cache->cmd, &nr_free_blocks_metadata); |
c6b4fcba | 3155 | if (r) { |
b61d9509 MS |
3156 | DMERR("%s: dm_cache_get_free_metadata_block_count returned %d", |
3157 | cache_device_name(cache), r); | |
c6b4fcba JT |
3158 | goto err; |
3159 | } | |
3160 | ||
3161 | r = dm_cache_get_metadata_dev_size(cache->cmd, &nr_blocks_metadata); | |
3162 | if (r) { | |
b61d9509 MS |
3163 | DMERR("%s: dm_cache_get_metadata_dev_size returned %d", |
3164 | cache_device_name(cache), r); | |
c6b4fcba JT |
3165 | goto err; |
3166 | } | |
3167 | ||
3168 | residency = policy_residency(cache->policy); | |
3169 | ||
ca763d0a | 3170 | DMEMIT("%u %llu/%llu %llu %llu/%llu %u %u %u %u %u %u %lu ", |
895b47d7 | 3171 | (unsigned)DM_CACHE_METADATA_BLOCK_SIZE, |
c6b4fcba JT |
3172 | (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), |
3173 | (unsigned long long)nr_blocks_metadata, | |
ca763d0a | 3174 | (unsigned long long)cache->sectors_per_block, |
6a388618 MS |
3175 | (unsigned long long) from_cblock(residency), |
3176 | (unsigned long long) from_cblock(cache->cache_size), | |
c6b4fcba JT |
3177 | (unsigned) atomic_read(&cache->stats.read_hit), |
3178 | (unsigned) atomic_read(&cache->stats.read_miss), | |
3179 | (unsigned) atomic_read(&cache->stats.write_hit), | |
3180 | (unsigned) atomic_read(&cache->stats.write_miss), | |
3181 | (unsigned) atomic_read(&cache->stats.demotion), | |
3182 | (unsigned) atomic_read(&cache->stats.promotion), | |
44fa816b | 3183 | (unsigned long) atomic_read(&cache->nr_dirty)); |
c6b4fcba | 3184 | |
de7180ff | 3185 | emit_flags(cache, result, maxlen, &sz); |
c6b4fcba JT |
3186 | |
3187 | DMEMIT("2 migration_threshold %llu ", (unsigned long long) cache->migration_threshold); | |
2e68c4e6 MS |
3188 | |
3189 | DMEMIT("%s ", dm_cache_policy_get_name(cache->policy)); | |
c6b4fcba | 3190 | if (sz < maxlen) { |
028ae9f7 | 3191 | r = policy_emit_config_values(cache->policy, result, maxlen, &sz); |
c6b4fcba | 3192 | if (r) |
b61d9509 MS |
3193 | DMERR("%s: policy_emit_config_values returned %d", |
3194 | cache_device_name(cache), r); | |
c6b4fcba JT |
3195 | } |
3196 | ||
028ae9f7 JT |
3197 | if (get_cache_mode(cache) == CM_READ_ONLY) |
3198 | DMEMIT("ro "); | |
3199 | else | |
3200 | DMEMIT("rw "); | |
3201 | ||
d14fcf3d JT |
3202 | r = dm_cache_metadata_needs_check(cache->cmd, &needs_check); |
3203 | ||
3204 | if (r || needs_check) | |
255eac20 MS |
3205 | DMEMIT("needs_check "); |
3206 | else | |
3207 | DMEMIT("- "); | |
3208 | ||
c6b4fcba JT |
3209 | break; |
3210 | ||
3211 | case STATUSTYPE_TABLE: | |
3212 | format_dev_t(buf, cache->metadata_dev->bdev->bd_dev); | |
3213 | DMEMIT("%s ", buf); | |
3214 | format_dev_t(buf, cache->cache_dev->bdev->bd_dev); | |
3215 | DMEMIT("%s ", buf); | |
3216 | format_dev_t(buf, cache->origin_dev->bdev->bd_dev); | |
3217 | DMEMIT("%s", buf); | |
3218 | ||
3219 | for (i = 0; i < cache->nr_ctr_args - 1; i++) | |
3220 | DMEMIT(" %s", cache->ctr_args[i]); | |
3221 | if (cache->nr_ctr_args) | |
3222 | DMEMIT(" %s", cache->ctr_args[cache->nr_ctr_args - 1]); | |
3223 | } | |
3224 | ||
3225 | return; | |
3226 | ||
3227 | err: | |
3228 | DMEMIT("Error"); | |
3229 | } | |
3230 | ||
b29d4986 JT |
3231 | /* |
3232 | * Defines a range of cblocks, begin to (end - 1) are in the range. end is | |
3233 | * the one-past-the-end value. | |
3234 | */ | |
3235 | struct cblock_range { | |
3236 | dm_cblock_t begin; | |
3237 | dm_cblock_t end; | |
3238 | }; | |
3239 | ||
c6b4fcba | 3240 | /* |
65790ff9 JT |
3241 | * A cache block range can take two forms: |
3242 | * | |
3243 | * i) A single cblock, eg. '3456' | |
b29d4986 | 3244 | * ii) A begin and end cblock with a dash between, eg. 123-234 |
65790ff9 JT |
3245 | */ |
3246 | static int parse_cblock_range(struct cache *cache, const char *str, | |
3247 | struct cblock_range *result) | |
3248 | { | |
3249 | char dummy; | |
3250 | uint64_t b, e; | |
3251 | int r; | |
3252 | ||
3253 | /* | |
3254 | * Try and parse form (ii) first. | |
3255 | */ | |
3256 | r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy); | |
3257 | if (r < 0) | |
3258 | return r; | |
3259 | ||
3260 | if (r == 2) { | |
3261 | result->begin = to_cblock(b); | |
3262 | result->end = to_cblock(e); | |
3263 | return 0; | |
3264 | } | |
3265 | ||
3266 | /* | |
3267 | * That didn't work, try form (i). | |
3268 | */ | |
3269 | r = sscanf(str, "%llu%c", &b, &dummy); | |
3270 | if (r < 0) | |
3271 | return r; | |
3272 | ||
3273 | if (r == 1) { | |
3274 | result->begin = to_cblock(b); | |
3275 | result->end = to_cblock(from_cblock(result->begin) + 1u); | |
3276 | return 0; | |
3277 | } | |
3278 | ||
b61d9509 | 3279 | DMERR("%s: invalid cblock range '%s'", cache_device_name(cache), str); |
65790ff9 JT |
3280 | return -EINVAL; |
3281 | } | |
3282 | ||
3283 | static int validate_cblock_range(struct cache *cache, struct cblock_range *range) | |
3284 | { | |
3285 | uint64_t b = from_cblock(range->begin); | |
3286 | uint64_t e = from_cblock(range->end); | |
3287 | uint64_t n = from_cblock(cache->cache_size); | |
3288 | ||
3289 | if (b >= n) { | |
b61d9509 MS |
3290 | DMERR("%s: begin cblock out of range: %llu >= %llu", |
3291 | cache_device_name(cache), b, n); | |
65790ff9 JT |
3292 | return -EINVAL; |
3293 | } | |
3294 | ||
3295 | if (e > n) { | |
b61d9509 MS |
3296 | DMERR("%s: end cblock out of range: %llu > %llu", |
3297 | cache_device_name(cache), e, n); | |
65790ff9 JT |
3298 | return -EINVAL; |
3299 | } | |
3300 | ||
3301 | if (b >= e) { | |
b61d9509 MS |
3302 | DMERR("%s: invalid cblock range: %llu >= %llu", |
3303 | cache_device_name(cache), b, e); | |
65790ff9 JT |
3304 | return -EINVAL; |
3305 | } | |
3306 | ||
3307 | return 0; | |
3308 | } | |
3309 | ||
b29d4986 JT |
3310 | static inline dm_cblock_t cblock_succ(dm_cblock_t b) |
3311 | { | |
3312 | return to_cblock(from_cblock(b) + 1); | |
3313 | } | |
3314 | ||
65790ff9 JT |
3315 | static int request_invalidation(struct cache *cache, struct cblock_range *range) |
3316 | { | |
b29d4986 | 3317 | int r = 0; |
65790ff9 | 3318 | |
b29d4986 JT |
3319 | /* |
3320 | * We don't need to do any locking here because we know we're in | |
3321 | * passthrough mode. There's is potential for a race between an | |
3322 | * invalidation triggered by an io and an invalidation message. This | |
3323 | * is harmless, we must not worry if the policy call fails. | |
3324 | */ | |
3325 | while (range->begin != range->end) { | |
3326 | r = invalidate_cblock(cache, range->begin); | |
3327 | if (r) | |
3328 | return r; | |
65790ff9 | 3329 | |
b29d4986 JT |
3330 | range->begin = cblock_succ(range->begin); |
3331 | } | |
65790ff9 | 3332 | |
b29d4986 JT |
3333 | cache->commit_requested = true; |
3334 | return r; | |
65790ff9 JT |
3335 | } |
3336 | ||
3337 | static int process_invalidate_cblocks_message(struct cache *cache, unsigned count, | |
3338 | const char **cblock_ranges) | |
3339 | { | |
3340 | int r = 0; | |
3341 | unsigned i; | |
3342 | struct cblock_range range; | |
3343 | ||
8e3c3827 | 3344 | if (!passthrough_mode(cache)) { |
b61d9509 MS |
3345 | DMERR("%s: cache has to be in passthrough mode for invalidation", |
3346 | cache_device_name(cache)); | |
65790ff9 JT |
3347 | return -EPERM; |
3348 | } | |
3349 | ||
3350 | for (i = 0; i < count; i++) { | |
3351 | r = parse_cblock_range(cache, cblock_ranges[i], &range); | |
3352 | if (r) | |
3353 | break; | |
3354 | ||
3355 | r = validate_cblock_range(cache, &range); | |
3356 | if (r) | |
3357 | break; | |
3358 | ||
3359 | /* | |
3360 | * Pass begin and end origin blocks to the worker and wake it. | |
3361 | */ | |
3362 | r = request_invalidation(cache, &range); | |
3363 | if (r) | |
3364 | break; | |
3365 | } | |
3366 | ||
3367 | return r; | |
3368 | } | |
3369 | ||
3370 | /* | |
3371 | * Supports | |
3372 | * "<key> <value>" | |
3373 | * and | |
3374 | * "invalidate_cblocks [(<begin>)|(<begin>-<end>)]* | |
c6b4fcba JT |
3375 | * |
3376 | * The key migration_threshold is supported by the cache target core. | |
3377 | */ | |
1eb5fa84 MS |
3378 | static int cache_message(struct dm_target *ti, unsigned argc, char **argv, |
3379 | char *result, unsigned maxlen) | |
c6b4fcba | 3380 | { |
c6b4fcba JT |
3381 | struct cache *cache = ti->private; |
3382 | ||
65790ff9 JT |
3383 | if (!argc) |
3384 | return -EINVAL; | |
3385 | ||
028ae9f7 | 3386 | if (get_cache_mode(cache) >= CM_READ_ONLY) { |
b61d9509 MS |
3387 | DMERR("%s: unable to service cache target messages in READ_ONLY or FAIL mode", |
3388 | cache_device_name(cache)); | |
028ae9f7 JT |
3389 | return -EOPNOTSUPP; |
3390 | } | |
3391 | ||
7b6b2bc9 | 3392 | if (!strcasecmp(argv[0], "invalidate_cblocks")) |
65790ff9 JT |
3393 | return process_invalidate_cblocks_message(cache, argc - 1, (const char **) argv + 1); |
3394 | ||
c6b4fcba JT |
3395 | if (argc != 2) |
3396 | return -EINVAL; | |
3397 | ||
2f14f4b5 | 3398 | return set_config_value(cache, argv[0], argv[1]); |
c6b4fcba JT |
3399 | } |
3400 | ||
3401 | static int cache_iterate_devices(struct dm_target *ti, | |
3402 | iterate_devices_callout_fn fn, void *data) | |
3403 | { | |
3404 | int r = 0; | |
3405 | struct cache *cache = ti->private; | |
3406 | ||
3407 | r = fn(ti, cache->cache_dev, 0, get_dev_size(cache->cache_dev), data); | |
3408 | if (!r) | |
3409 | r = fn(ti, cache->origin_dev, 0, ti->len, data); | |
3410 | ||
3411 | return r; | |
3412 | } | |
3413 | ||
de7180ff MS |
3414 | static bool origin_dev_supports_discard(struct block_device *origin_bdev) |
3415 | { | |
3416 | struct request_queue *q = bdev_get_queue(origin_bdev); | |
3417 | ||
3418 | return q && blk_queue_discard(q); | |
3419 | } | |
3420 | ||
3421 | /* | |
3422 | * If discard_passdown was enabled verify that the origin device | |
3423 | * supports discards. Disable discard_passdown if not. | |
3424 | */ | |
3425 | static void disable_passdown_if_not_supported(struct cache *cache) | |
3426 | { | |
3427 | struct block_device *origin_bdev = cache->origin_dev->bdev; | |
3428 | struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits; | |
3429 | const char *reason = NULL; | |
3430 | char buf[BDEVNAME_SIZE]; | |
3431 | ||
3432 | if (!cache->features.discard_passdown) | |
3433 | return; | |
3434 | ||
3435 | if (!origin_dev_supports_discard(origin_bdev)) | |
3436 | reason = "discard unsupported"; | |
3437 | ||
3438 | else if (origin_limits->max_discard_sectors < cache->sectors_per_block) | |
3439 | reason = "max discard sectors smaller than a block"; | |
3440 | ||
3441 | if (reason) { | |
3442 | DMWARN("Origin device (%s) %s: Disabling discard passdown.", | |
3443 | bdevname(origin_bdev, buf), reason); | |
3444 | cache->features.discard_passdown = false; | |
3445 | } | |
3446 | } | |
3447 | ||
c6b4fcba JT |
3448 | static void set_discard_limits(struct cache *cache, struct queue_limits *limits) |
3449 | { | |
de7180ff MS |
3450 | struct block_device *origin_bdev = cache->origin_dev->bdev; |
3451 | struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits; | |
3452 | ||
3453 | if (!cache->features.discard_passdown) { | |
3454 | /* No passdown is done so setting own virtual limits */ | |
3455 | limits->max_discard_sectors = min_t(sector_t, cache->discard_block_size * 1024, | |
3456 | cache->origin_sectors); | |
3457 | limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT; | |
3458 | return; | |
3459 | } | |
3460 | ||
c6b4fcba | 3461 | /* |
de7180ff MS |
3462 | * cache_iterate_devices() is stacking both origin and fast device limits |
3463 | * but discards aren't passed to fast device, so inherit origin's limits. | |
c6b4fcba | 3464 | */ |
de7180ff MS |
3465 | limits->max_discard_sectors = origin_limits->max_discard_sectors; |
3466 | limits->max_hw_discard_sectors = origin_limits->max_hw_discard_sectors; | |
3467 | limits->discard_granularity = origin_limits->discard_granularity; | |
3468 | limits->discard_alignment = origin_limits->discard_alignment; | |
3469 | limits->discard_misaligned = origin_limits->discard_misaligned; | |
c6b4fcba JT |
3470 | } |
3471 | ||
3472 | static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
3473 | { | |
3474 | struct cache *cache = ti->private; | |
f6109372 | 3475 | uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; |
c6b4fcba | 3476 | |
f6109372 MS |
3477 | /* |
3478 | * If the system-determined stacked limits are compatible with the | |
3479 | * cache's blocksize (io_opt is a factor) do not override them. | |
3480 | */ | |
3481 | if (io_opt_sectors < cache->sectors_per_block || | |
3482 | do_div(io_opt_sectors, cache->sectors_per_block)) { | |
b0246530 | 3483 | blk_limits_io_min(limits, cache->sectors_per_block << SECTOR_SHIFT); |
f6109372 MS |
3484 | blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT); |
3485 | } | |
de7180ff MS |
3486 | |
3487 | disable_passdown_if_not_supported(cache); | |
c6b4fcba JT |
3488 | set_discard_limits(cache, limits); |
3489 | } | |
3490 | ||
3491 | /*----------------------------------------------------------------*/ | |
3492 | ||
3493 | static struct target_type cache_target = { | |
3494 | .name = "cache", | |
636be424 | 3495 | .version = {2, 2, 0}, |
c6b4fcba JT |
3496 | .module = THIS_MODULE, |
3497 | .ctr = cache_ctr, | |
3498 | .dtr = cache_dtr, | |
3499 | .map = cache_map, | |
3500 | .end_io = cache_end_io, | |
3501 | .postsuspend = cache_postsuspend, | |
3502 | .preresume = cache_preresume, | |
3503 | .resume = cache_resume, | |
3504 | .status = cache_status, | |
3505 | .message = cache_message, | |
3506 | .iterate_devices = cache_iterate_devices, | |
c6b4fcba JT |
3507 | .io_hints = cache_io_hints, |
3508 | }; | |
3509 | ||
3510 | static int __init dm_cache_init(void) | |
3511 | { | |
3512 | int r; | |
3513 | ||
c6b4fcba | 3514 | migration_cache = KMEM_CACHE(dm_cache_migration, 0); |
c7cd5550 | 3515 | if (!migration_cache) |
c6b4fcba | 3516 | return -ENOMEM; |
c6b4fcba | 3517 | |
7e6358d2 | 3518 | r = dm_register_target(&cache_target); |
3519 | if (r) { | |
3520 | DMERR("cache target registration failed: %d", r); | |
c7cd5550 | 3521 | kmem_cache_destroy(migration_cache); |
7e6358d2 | 3522 | return r; |
3523 | } | |
3524 | ||
c6b4fcba JT |
3525 | return 0; |
3526 | } | |
3527 | ||
3528 | static void __exit dm_cache_exit(void) | |
3529 | { | |
3530 | dm_unregister_target(&cache_target); | |
3531 | kmem_cache_destroy(migration_cache); | |
3532 | } | |
3533 | ||
3534 | module_init(dm_cache_init); | |
3535 | module_exit(dm_cache_exit); | |
3536 | ||
3537 | MODULE_DESCRIPTION(DM_NAME " cache target"); | |
3538 | MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); | |
3539 | MODULE_LICENSE("GPL"); |