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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 | |
c6b4fcba JT |
424 | /* |
425 | * origin_blocks entries, discarded if set. | |
426 | */ | |
1bad9bc4 | 427 | dm_dblock_t discard_nr_blocks; |
c6b4fcba | 428 | unsigned long *discard_bitset; |
08b18451 | 429 | uint32_t discard_block_size; /* a power of 2 times sectors per block */ |
c9ec5d7c MS |
430 | |
431 | /* | |
432 | * Rather than reconstructing the table line for the status we just | |
433 | * save it and regurgitate. | |
434 | */ | |
435 | unsigned nr_ctr_args; | |
436 | const char **ctr_args; | |
c6b4fcba JT |
437 | |
438 | struct dm_kcopyd_client *copier; | |
b29d4986 | 439 | struct work_struct deferred_bio_worker; |
b29d4986 | 440 | struct work_struct migration_worker; |
72d711c8 | 441 | struct workqueue_struct *wq; |
c6b4fcba | 442 | struct delayed_work waker; |
b29d4986 | 443 | struct dm_bio_prison_v2 *prison; |
c6b4fcba | 444 | |
72d711c8 MS |
445 | /* |
446 | * cache_size entries, dirty if set | |
447 | */ | |
448 | unsigned long *dirty_bitset; | |
449 | atomic_t nr_dirty; | |
c6b4fcba | 450 | |
c6b4fcba | 451 | unsigned policy_nr_args; |
72d711c8 MS |
452 | struct dm_cache_policy *policy; |
453 | ||
454 | /* | |
455 | * Cache features such as write-through. | |
456 | */ | |
457 | struct cache_features features; | |
458 | ||
459 | struct cache_stats stats; | |
c6b4fcba JT |
460 | |
461 | bool need_tick_bio:1; | |
462 | bool sized:1; | |
65790ff9 | 463 | bool invalidate:1; |
c6b4fcba JT |
464 | bool commit_requested:1; |
465 | bool loaded_mappings:1; | |
466 | bool loaded_discards:1; | |
467 | ||
72d711c8 | 468 | struct rw_semaphore background_work_lock; |
65790ff9 | 469 | |
72d711c8 MS |
470 | struct batcher committer; |
471 | struct work_struct commit_ws; | |
066dbaa3 | 472 | |
701e03e4 | 473 | struct io_tracker tracker; |
b29d4986 | 474 | |
72d711c8 | 475 | mempool_t migration_pool; |
b29d4986 | 476 | |
72d711c8 | 477 | struct bio_set bs; |
c6b4fcba JT |
478 | }; |
479 | ||
480 | struct per_bio_data { | |
481 | bool tick:1; | |
482 | unsigned req_nr:2; | |
b29d4986 | 483 | struct dm_bio_prison_cell_v2 *cell; |
c6eda5e8 | 484 | struct dm_hook_info hook_info; |
066dbaa3 | 485 | sector_t len; |
c6b4fcba JT |
486 | }; |
487 | ||
488 | struct dm_cache_migration { | |
b29d4986 | 489 | struct continuation k; |
c6b4fcba JT |
490 | struct cache *cache; |
491 | ||
b29d4986 JT |
492 | struct policy_work *op; |
493 | struct bio *overwrite_bio; | |
494 | struct dm_bio_prison_cell_v2 *cell; | |
c6b4fcba | 495 | |
b29d4986 JT |
496 | dm_cblock_t invalidate_cblock; |
497 | dm_oblock_t invalidate_oblock; | |
c6b4fcba JT |
498 | }; |
499 | ||
b29d4986 JT |
500 | /*----------------------------------------------------------------*/ |
501 | ||
8e3c3827 | 502 | static bool writethrough_mode(struct cache *cache) |
b29d4986 | 503 | { |
8e3c3827 | 504 | return cache->features.io_mode == CM_IO_WRITETHROUGH; |
b29d4986 JT |
505 | } |
506 | ||
8e3c3827 | 507 | static bool writeback_mode(struct cache *cache) |
b29d4986 | 508 | { |
8e3c3827 | 509 | return cache->features.io_mode == CM_IO_WRITEBACK; |
b29d4986 JT |
510 | } |
511 | ||
8e3c3827 | 512 | static inline bool passthrough_mode(struct cache *cache) |
b29d4986 | 513 | { |
8e3c3827 | 514 | return unlikely(cache->features.io_mode == CM_IO_PASSTHROUGH); |
b29d4986 JT |
515 | } |
516 | ||
517 | /*----------------------------------------------------------------*/ | |
518 | ||
519 | static void wake_deferred_bio_worker(struct cache *cache) | |
520 | { | |
521 | queue_work(cache->wq, &cache->deferred_bio_worker); | |
522 | } | |
c6b4fcba | 523 | |
b29d4986 | 524 | static void wake_migration_worker(struct cache *cache) |
c6b4fcba | 525 | { |
8e3c3827 | 526 | if (passthrough_mode(cache)) |
b29d4986 JT |
527 | return; |
528 | ||
529 | queue_work(cache->wq, &cache->migration_worker); | |
c6b4fcba JT |
530 | } |
531 | ||
532 | /*----------------------------------------------------------------*/ | |
533 | ||
b29d4986 | 534 | static struct dm_bio_prison_cell_v2 *alloc_prison_cell(struct cache *cache) |
c6b4fcba | 535 | { |
13bd677a | 536 | return dm_bio_prison_alloc_cell_v2(cache->prison, GFP_NOIO); |
c6b4fcba JT |
537 | } |
538 | ||
b29d4986 | 539 | static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell_v2 *cell) |
c6b4fcba | 540 | { |
b29d4986 | 541 | dm_bio_prison_free_cell_v2(cache->prison, cell); |
c6b4fcba JT |
542 | } |
543 | ||
a59db676 JT |
544 | static struct dm_cache_migration *alloc_migration(struct cache *cache) |
545 | { | |
546 | struct dm_cache_migration *mg; | |
547 | ||
13bd677a | 548 | mg = mempool_alloc(&cache->migration_pool, GFP_NOIO); |
ef7afb36 MS |
549 | |
550 | memset(mg, 0, sizeof(*mg)); | |
551 | ||
552 | mg->cache = cache; | |
553 | atomic_inc(&cache->nr_allocated_migrations); | |
a59db676 JT |
554 | |
555 | return mg; | |
556 | } | |
557 | ||
558 | static void free_migration(struct dm_cache_migration *mg) | |
559 | { | |
88bf5184 | 560 | struct cache *cache = mg->cache; |
a59db676 | 561 | |
88bf5184 JT |
562 | if (atomic_dec_and_test(&cache->nr_allocated_migrations)) |
563 | wake_up(&cache->migration_wait); | |
564 | ||
6f1c819c | 565 | mempool_free(mg, &cache->migration_pool); |
a59db676 JT |
566 | } |
567 | ||
b29d4986 | 568 | /*----------------------------------------------------------------*/ |
c6b4fcba | 569 | |
b29d4986 | 570 | static inline dm_oblock_t oblock_succ(dm_oblock_t b) |
c6b4fcba | 571 | { |
b29d4986 | 572 | return to_oblock(from_oblock(b) + 1ull); |
c6b4fcba JT |
573 | } |
574 | ||
b29d4986 | 575 | static void build_key(dm_oblock_t begin, dm_oblock_t end, struct dm_cell_key_v2 *key) |
c6b4fcba | 576 | { |
b29d4986 JT |
577 | key->virtual = 0; |
578 | key->dev = 0; | |
579 | key->block_begin = from_oblock(begin); | |
580 | key->block_end = from_oblock(end); | |
c6b4fcba JT |
581 | } |
582 | ||
583 | /* | |
b29d4986 JT |
584 | * We have two lock levels. Level 0, which is used to prevent WRITEs, and |
585 | * level 1 which prevents *both* READs and WRITEs. | |
c6b4fcba | 586 | */ |
b29d4986 JT |
587 | #define WRITE_LOCK_LEVEL 0 |
588 | #define READ_WRITE_LOCK_LEVEL 1 | |
589 | ||
590 | static unsigned lock_level(struct bio *bio) | |
c6b4fcba | 591 | { |
b29d4986 JT |
592 | return bio_data_dir(bio) == WRITE ? |
593 | WRITE_LOCK_LEVEL : | |
594 | READ_WRITE_LOCK_LEVEL; | |
595 | } | |
c6b4fcba | 596 | |
b29d4986 JT |
597 | /*---------------------------------------------------------------- |
598 | * Per bio data | |
599 | *--------------------------------------------------------------*/ | |
c6b4fcba | 600 | |
693b960e | 601 | static struct per_bio_data *get_per_bio_data(struct bio *bio) |
b29d4986 | 602 | { |
693b960e | 603 | struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data)); |
b29d4986 JT |
604 | BUG_ON(!pb); |
605 | return pb; | |
606 | } | |
c6b4fcba | 607 | |
693b960e | 608 | static struct per_bio_data *init_per_bio_data(struct bio *bio) |
b29d4986 | 609 | { |
693b960e | 610 | struct per_bio_data *pb = get_per_bio_data(bio); |
c6b4fcba | 611 | |
b29d4986 JT |
612 | pb->tick = false; |
613 | pb->req_nr = dm_bio_get_target_bio_nr(bio); | |
614 | pb->cell = NULL; | |
615 | pb->len = 0; | |
616 | ||
617 | return pb; | |
c6b4fcba JT |
618 | } |
619 | ||
620 | /*----------------------------------------------------------------*/ | |
621 | ||
b29d4986 | 622 | static void defer_bio(struct cache *cache, struct bio *bio) |
c6b4fcba | 623 | { |
26b924b9 | 624 | spin_lock_irq(&cache->lock); |
b29d4986 | 625 | bio_list_add(&cache->deferred_bios, bio); |
26b924b9 | 626 | spin_unlock_irq(&cache->lock); |
b29d4986 JT |
627 | |
628 | wake_deferred_bio_worker(cache); | |
629 | } | |
c6b4fcba | 630 | |
b29d4986 | 631 | static void defer_bios(struct cache *cache, struct bio_list *bios) |
c6b4fcba | 632 | { |
26b924b9 | 633 | spin_lock_irq(&cache->lock); |
b29d4986 JT |
634 | bio_list_merge(&cache->deferred_bios, bios); |
635 | bio_list_init(bios); | |
26b924b9 | 636 | spin_unlock_irq(&cache->lock); |
c6b4fcba | 637 | |
b29d4986 | 638 | wake_deferred_bio_worker(cache); |
c6b4fcba JT |
639 | } |
640 | ||
b29d4986 JT |
641 | /*----------------------------------------------------------------*/ |
642 | ||
643 | static bool bio_detain_shared(struct cache *cache, dm_oblock_t oblock, struct bio *bio) | |
7ae34e77 | 644 | { |
b29d4986 | 645 | bool r; |
b29d4986 JT |
646 | struct per_bio_data *pb; |
647 | struct dm_cell_key_v2 key; | |
7ae34e77 | 648 | dm_oblock_t end = to_oblock(from_oblock(oblock) + 1ULL); |
b29d4986 | 649 | struct dm_bio_prison_cell_v2 *cell_prealloc, *cell; |
7ae34e77 | 650 | |
b29d4986 | 651 | cell_prealloc = alloc_prison_cell(cache); /* FIXME: allow wait if calling from worker */ |
b29d4986 JT |
652 | |
653 | build_key(oblock, end, &key); | |
654 | r = dm_cell_get_v2(cache->prison, &key, lock_level(bio), bio, cell_prealloc, &cell); | |
655 | if (!r) { | |
656 | /* | |
657 | * Failed to get the lock. | |
658 | */ | |
659 | free_prison_cell(cache, cell_prealloc); | |
660 | return r; | |
661 | } | |
c6b4fcba | 662 | |
b29d4986 JT |
663 | if (cell != cell_prealloc) |
664 | free_prison_cell(cache, cell_prealloc); | |
c6b4fcba | 665 | |
693b960e | 666 | pb = get_per_bio_data(bio); |
b29d4986 | 667 | pb->cell = cell; |
c6b4fcba JT |
668 | |
669 | return r; | |
670 | } | |
671 | ||
aeed1420 | 672 | /*----------------------------------------------------------------*/ |
c6b4fcba JT |
673 | |
674 | static bool is_dirty(struct cache *cache, dm_cblock_t b) | |
675 | { | |
676 | return test_bit(from_cblock(b), cache->dirty_bitset); | |
677 | } | |
678 | ||
b29d4986 | 679 | static void set_dirty(struct cache *cache, dm_cblock_t cblock) |
c6b4fcba JT |
680 | { |
681 | if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
44fa816b | 682 | atomic_inc(&cache->nr_dirty); |
b29d4986 | 683 | policy_set_dirty(cache->policy, cblock); |
c6b4fcba JT |
684 | } |
685 | } | |
686 | ||
b29d4986 JT |
687 | /* |
688 | * These two are called when setting after migrations to force the policy | |
689 | * and dirty bitset to be in sync. | |
690 | */ | |
691 | static void force_set_dirty(struct cache *cache, dm_cblock_t cblock) | |
692 | { | |
693 | if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) | |
694 | atomic_inc(&cache->nr_dirty); | |
695 | policy_set_dirty(cache->policy, cblock); | |
696 | } | |
697 | ||
698 | static void force_clear_dirty(struct cache *cache, dm_cblock_t cblock) | |
c6b4fcba JT |
699 | { |
700 | if (test_and_clear_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
44fa816b | 701 | if (atomic_dec_return(&cache->nr_dirty) == 0) |
c6b4fcba JT |
702 | dm_table_event(cache->ti->table); |
703 | } | |
b29d4986 JT |
704 | |
705 | policy_clear_dirty(cache->policy, cblock); | |
c6b4fcba JT |
706 | } |
707 | ||
708 | /*----------------------------------------------------------------*/ | |
aeed1420 | 709 | |
c6b4fcba JT |
710 | static bool block_size_is_power_of_two(struct cache *cache) |
711 | { | |
712 | return cache->sectors_per_block_shift >= 0; | |
713 | } | |
714 | ||
414dd67d JT |
715 | static dm_block_t block_div(dm_block_t b, uint32_t n) |
716 | { | |
717 | do_div(b, n); | |
718 | ||
719 | return b; | |
720 | } | |
721 | ||
7ae34e77 | 722 | static dm_block_t oblocks_per_dblock(struct cache *cache) |
1bad9bc4 | 723 | { |
7ae34e77 | 724 | dm_block_t oblocks = cache->discard_block_size; |
1bad9bc4 | 725 | |
7ae34e77 JT |
726 | if (block_size_is_power_of_two(cache)) |
727 | oblocks >>= cache->sectors_per_block_shift; | |
1bad9bc4 | 728 | else |
7ae34e77 | 729 | oblocks = block_div(oblocks, cache->sectors_per_block); |
1bad9bc4 | 730 | |
7ae34e77 JT |
731 | return oblocks; |
732 | } | |
733 | ||
734 | static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock) | |
735 | { | |
736 | return to_dblock(block_div(from_oblock(oblock), | |
737 | oblocks_per_dblock(cache))); | |
738 | } | |
1bad9bc4 | 739 | |
1bad9bc4 | 740 | static void set_discard(struct cache *cache, dm_dblock_t b) |
c6b4fcba | 741 | { |
7ae34e77 | 742 | BUG_ON(from_dblock(b) >= from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
743 | atomic_inc(&cache->stats.discard_count); |
744 | ||
26b924b9 | 745 | spin_lock_irq(&cache->lock); |
1bad9bc4 | 746 | set_bit(from_dblock(b), cache->discard_bitset); |
26b924b9 | 747 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
748 | } |
749 | ||
1bad9bc4 | 750 | static void clear_discard(struct cache *cache, dm_dblock_t b) |
c6b4fcba | 751 | { |
26b924b9 | 752 | spin_lock_irq(&cache->lock); |
1bad9bc4 | 753 | clear_bit(from_dblock(b), cache->discard_bitset); |
26b924b9 | 754 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
755 | } |
756 | ||
1bad9bc4 | 757 | static bool is_discarded(struct cache *cache, dm_dblock_t b) |
c6b4fcba JT |
758 | { |
759 | int r; | |
26b924b9 | 760 | spin_lock_irq(&cache->lock); |
1bad9bc4 | 761 | r = test_bit(from_dblock(b), cache->discard_bitset); |
26b924b9 | 762 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
763 | |
764 | return r; | |
765 | } | |
766 | ||
767 | static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b) | |
768 | { | |
769 | int r; | |
26b924b9 | 770 | spin_lock_irq(&cache->lock); |
1bad9bc4 JT |
771 | r = test_bit(from_dblock(oblock_to_dblock(cache, b)), |
772 | cache->discard_bitset); | |
26b924b9 | 773 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
774 | |
775 | return r; | |
776 | } | |
777 | ||
b29d4986 JT |
778 | /*---------------------------------------------------------------- |
779 | * Remapping | |
780 | *--------------------------------------------------------------*/ | |
781 | static void remap_to_origin(struct cache *cache, struct bio *bio) | |
c6b4fcba | 782 | { |
74d46992 | 783 | bio_set_dev(bio, cache->origin_dev->bdev); |
c6b4fcba JT |
784 | } |
785 | ||
786 | static void remap_to_cache(struct cache *cache, struct bio *bio, | |
787 | dm_cblock_t cblock) | |
788 | { | |
4f024f37 | 789 | sector_t bi_sector = bio->bi_iter.bi_sector; |
e0d849fa | 790 | sector_t block = from_cblock(cblock); |
c6b4fcba | 791 | |
74d46992 | 792 | bio_set_dev(bio, cache->cache_dev->bdev); |
c6b4fcba | 793 | if (!block_size_is_power_of_two(cache)) |
4f024f37 | 794 | bio->bi_iter.bi_sector = |
e0d849fa | 795 | (block * cache->sectors_per_block) + |
4f024f37 | 796 | sector_div(bi_sector, cache->sectors_per_block); |
c6b4fcba | 797 | else |
4f024f37 | 798 | bio->bi_iter.bi_sector = |
e0d849fa | 799 | (block << cache->sectors_per_block_shift) | |
4f024f37 | 800 | (bi_sector & (cache->sectors_per_block - 1)); |
c6b4fcba JT |
801 | } |
802 | ||
803 | static void check_if_tick_bio_needed(struct cache *cache, struct bio *bio) | |
804 | { | |
693b960e | 805 | struct per_bio_data *pb; |
c6b4fcba | 806 | |
26b924b9 | 807 | spin_lock_irq(&cache->lock); |
f73f44eb | 808 | if (cache->need_tick_bio && !op_is_flush(bio->bi_opf) && |
e6047149 | 809 | bio_op(bio) != REQ_OP_DISCARD) { |
693b960e | 810 | pb = get_per_bio_data(bio); |
c6b4fcba JT |
811 | pb->tick = true; |
812 | cache->need_tick_bio = false; | |
813 | } | |
26b924b9 | 814 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
815 | } |
816 | ||
2df3bae9 MS |
817 | static void __remap_to_origin_clear_discard(struct cache *cache, struct bio *bio, |
818 | dm_oblock_t oblock, bool bio_has_pbd) | |
c6b4fcba | 819 | { |
2df3bae9 MS |
820 | if (bio_has_pbd) |
821 | check_if_tick_bio_needed(cache, bio); | |
c6b4fcba JT |
822 | remap_to_origin(cache, bio); |
823 | if (bio_data_dir(bio) == WRITE) | |
1bad9bc4 | 824 | clear_discard(cache, oblock_to_dblock(cache, oblock)); |
c6b4fcba JT |
825 | } |
826 | ||
2df3bae9 MS |
827 | static void remap_to_origin_clear_discard(struct cache *cache, struct bio *bio, |
828 | dm_oblock_t oblock) | |
829 | { | |
830 | // FIXME: check_if_tick_bio_needed() is called way too much through this interface | |
831 | __remap_to_origin_clear_discard(cache, bio, oblock, true); | |
832 | } | |
833 | ||
c6b4fcba JT |
834 | static void remap_to_cache_dirty(struct cache *cache, struct bio *bio, |
835 | dm_oblock_t oblock, dm_cblock_t cblock) | |
836 | { | |
f8e5f01a | 837 | check_if_tick_bio_needed(cache, bio); |
c6b4fcba JT |
838 | remap_to_cache(cache, bio, cblock); |
839 | if (bio_data_dir(bio) == WRITE) { | |
b29d4986 | 840 | set_dirty(cache, cblock); |
1bad9bc4 | 841 | clear_discard(cache, oblock_to_dblock(cache, oblock)); |
c6b4fcba JT |
842 | } |
843 | } | |
844 | ||
845 | static dm_oblock_t get_bio_block(struct cache *cache, struct bio *bio) | |
846 | { | |
4f024f37 | 847 | sector_t block_nr = bio->bi_iter.bi_sector; |
c6b4fcba JT |
848 | |
849 | if (!block_size_is_power_of_two(cache)) | |
850 | (void) sector_div(block_nr, cache->sectors_per_block); | |
851 | else | |
852 | block_nr >>= cache->sectors_per_block_shift; | |
853 | ||
854 | return to_oblock(block_nr); | |
855 | } | |
856 | ||
066dbaa3 JT |
857 | static bool accountable_bio(struct cache *cache, struct bio *bio) |
858 | { | |
701e03e4 | 859 | return bio_op(bio) != REQ_OP_DISCARD; |
066dbaa3 JT |
860 | } |
861 | ||
862 | static void accounted_begin(struct cache *cache, struct bio *bio) | |
863 | { | |
693b960e | 864 | struct per_bio_data *pb; |
066dbaa3 JT |
865 | |
866 | if (accountable_bio(cache, bio)) { | |
693b960e | 867 | pb = get_per_bio_data(bio); |
066dbaa3 | 868 | pb->len = bio_sectors(bio); |
701e03e4 | 869 | iot_io_begin(&cache->tracker, pb->len); |
066dbaa3 JT |
870 | } |
871 | } | |
872 | ||
873 | static void accounted_complete(struct cache *cache, struct bio *bio) | |
874 | { | |
693b960e | 875 | struct per_bio_data *pb = get_per_bio_data(bio); |
066dbaa3 | 876 | |
701e03e4 | 877 | iot_io_end(&cache->tracker, pb->len); |
066dbaa3 JT |
878 | } |
879 | ||
880 | static void accounted_request(struct cache *cache, struct bio *bio) | |
881 | { | |
882 | accounted_begin(cache, bio); | |
ed00aabd | 883 | submit_bio_noacct(bio); |
066dbaa3 JT |
884 | } |
885 | ||
b29d4986 | 886 | static void issue_op(struct bio *bio, void *context) |
8c081b52 | 887 | { |
b29d4986 JT |
888 | struct cache *cache = context; |
889 | accounted_request(cache, bio); | |
8c081b52 JT |
890 | } |
891 | ||
e2e74d61 JT |
892 | /* |
893 | * When running in writethrough mode we need to send writes to clean blocks | |
2df3bae9 | 894 | * to both the cache and origin devices. Clone the bio and send them in parallel. |
e2e74d61 | 895 | */ |
2df3bae9 MS |
896 | static void remap_to_origin_and_cache(struct cache *cache, struct bio *bio, |
897 | dm_oblock_t oblock, dm_cblock_t cblock) | |
e2e74d61 | 898 | { |
6f1c819c | 899 | struct bio *origin_bio = bio_clone_fast(bio, GFP_NOIO, &cache->bs); |
2df3bae9 MS |
900 | |
901 | BUG_ON(!origin_bio); | |
e2e74d61 | 902 | |
2df3bae9 MS |
903 | bio_chain(origin_bio, bio); |
904 | /* | |
905 | * Passing false to __remap_to_origin_clear_discard() skips | |
906 | * all code that might use per_bio_data (since clone doesn't have it) | |
907 | */ | |
908 | __remap_to_origin_clear_discard(cache, origin_bio, oblock, false); | |
909 | submit_bio(origin_bio); | |
e2e74d61 | 910 | |
2df3bae9 | 911 | remap_to_cache(cache, bio, cblock); |
e2e74d61 JT |
912 | } |
913 | ||
028ae9f7 JT |
914 | /*---------------------------------------------------------------- |
915 | * Failure modes | |
916 | *--------------------------------------------------------------*/ | |
917 | static enum cache_metadata_mode get_cache_mode(struct cache *cache) | |
918 | { | |
919 | return cache->features.mode; | |
920 | } | |
921 | ||
b61d9509 MS |
922 | static const char *cache_device_name(struct cache *cache) |
923 | { | |
d4a512ed | 924 | return dm_table_device_name(cache->ti->table); |
b61d9509 MS |
925 | } |
926 | ||
028ae9f7 JT |
927 | static void notify_mode_switch(struct cache *cache, enum cache_metadata_mode mode) |
928 | { | |
929 | const char *descs[] = { | |
930 | "write", | |
931 | "read-only", | |
932 | "fail" | |
933 | }; | |
934 | ||
935 | dm_table_event(cache->ti->table); | |
b61d9509 MS |
936 | DMINFO("%s: switching cache to %s mode", |
937 | cache_device_name(cache), descs[(int)mode]); | |
028ae9f7 JT |
938 | } |
939 | ||
940 | static void set_cache_mode(struct cache *cache, enum cache_metadata_mode new_mode) | |
941 | { | |
d14fcf3d | 942 | bool needs_check; |
028ae9f7 JT |
943 | enum cache_metadata_mode old_mode = get_cache_mode(cache); |
944 | ||
d14fcf3d | 945 | if (dm_cache_metadata_needs_check(cache->cmd, &needs_check)) { |
23cab26d MS |
946 | DMERR("%s: unable to read needs_check flag, setting failure mode.", |
947 | cache_device_name(cache)); | |
d14fcf3d JT |
948 | new_mode = CM_FAIL; |
949 | } | |
950 | ||
028ae9f7 | 951 | if (new_mode == CM_WRITE && needs_check) { |
b61d9509 MS |
952 | DMERR("%s: unable to switch cache to write mode until repaired.", |
953 | cache_device_name(cache)); | |
028ae9f7 JT |
954 | if (old_mode != new_mode) |
955 | new_mode = old_mode; | |
956 | else | |
957 | new_mode = CM_READ_ONLY; | |
958 | } | |
959 | ||
960 | /* Never move out of fail mode */ | |
961 | if (old_mode == CM_FAIL) | |
962 | new_mode = CM_FAIL; | |
963 | ||
964 | switch (new_mode) { | |
965 | case CM_FAIL: | |
966 | case CM_READ_ONLY: | |
967 | dm_cache_metadata_set_read_only(cache->cmd); | |
968 | break; | |
969 | ||
970 | case CM_WRITE: | |
971 | dm_cache_metadata_set_read_write(cache->cmd); | |
972 | break; | |
973 | } | |
974 | ||
975 | cache->features.mode = new_mode; | |
976 | ||
977 | if (new_mode != old_mode) | |
978 | notify_mode_switch(cache, new_mode); | |
979 | } | |
980 | ||
981 | static void abort_transaction(struct cache *cache) | |
982 | { | |
b61d9509 MS |
983 | const char *dev_name = cache_device_name(cache); |
984 | ||
028ae9f7 JT |
985 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
986 | return; | |
987 | ||
988 | if (dm_cache_metadata_set_needs_check(cache->cmd)) { | |
b61d9509 | 989 | DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name); |
028ae9f7 JT |
990 | set_cache_mode(cache, CM_FAIL); |
991 | } | |
992 | ||
b61d9509 | 993 | DMERR_LIMIT("%s: aborting current metadata transaction", dev_name); |
028ae9f7 | 994 | if (dm_cache_metadata_abort(cache->cmd)) { |
b61d9509 | 995 | DMERR("%s: failed to abort metadata transaction", dev_name); |
028ae9f7 JT |
996 | set_cache_mode(cache, CM_FAIL); |
997 | } | |
998 | } | |
999 | ||
1000 | static void metadata_operation_failed(struct cache *cache, const char *op, int r) | |
1001 | { | |
b61d9509 MS |
1002 | DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d", |
1003 | cache_device_name(cache), op, r); | |
028ae9f7 JT |
1004 | abort_transaction(cache); |
1005 | set_cache_mode(cache, CM_READ_ONLY); | |
1006 | } | |
1007 | ||
b29d4986 JT |
1008 | /*----------------------------------------------------------------*/ |
1009 | ||
1010 | static void load_stats(struct cache *cache) | |
1011 | { | |
1012 | struct dm_cache_statistics stats; | |
1013 | ||
1014 | dm_cache_metadata_get_stats(cache->cmd, &stats); | |
1015 | atomic_set(&cache->stats.read_hit, stats.read_hits); | |
1016 | atomic_set(&cache->stats.read_miss, stats.read_misses); | |
1017 | atomic_set(&cache->stats.write_hit, stats.write_hits); | |
1018 | atomic_set(&cache->stats.write_miss, stats.write_misses); | |
1019 | } | |
1020 | ||
1021 | static void save_stats(struct cache *cache) | |
1022 | { | |
1023 | struct dm_cache_statistics stats; | |
1024 | ||
1025 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
1026 | return; | |
1027 | ||
1028 | stats.read_hits = atomic_read(&cache->stats.read_hit); | |
1029 | stats.read_misses = atomic_read(&cache->stats.read_miss); | |
1030 | stats.write_hits = atomic_read(&cache->stats.write_hit); | |
1031 | stats.write_misses = atomic_read(&cache->stats.write_miss); | |
1032 | ||
1033 | dm_cache_metadata_set_stats(cache->cmd, &stats); | |
1034 | } | |
1035 | ||
1036 | static void update_stats(struct cache_stats *stats, enum policy_operation op) | |
1037 | { | |
1038 | switch (op) { | |
1039 | case POLICY_PROMOTE: | |
1040 | atomic_inc(&stats->promotion); | |
1041 | break; | |
1042 | ||
1043 | case POLICY_DEMOTE: | |
1044 | atomic_inc(&stats->demotion); | |
1045 | break; | |
1046 | ||
1047 | case POLICY_WRITEBACK: | |
1048 | atomic_inc(&stats->writeback); | |
1049 | break; | |
1050 | } | |
1051 | } | |
1052 | ||
c6b4fcba JT |
1053 | /*---------------------------------------------------------------- |
1054 | * Migration processing | |
1055 | * | |
1056 | * Migration covers moving data from the origin device to the cache, or | |
1057 | * vice versa. | |
1058 | *--------------------------------------------------------------*/ | |
b29d4986 | 1059 | |
a59db676 | 1060 | static void inc_io_migrations(struct cache *cache) |
c6b4fcba | 1061 | { |
a59db676 | 1062 | atomic_inc(&cache->nr_io_migrations); |
c6b4fcba JT |
1063 | } |
1064 | ||
a59db676 | 1065 | static void dec_io_migrations(struct cache *cache) |
c6b4fcba | 1066 | { |
a59db676 | 1067 | atomic_dec(&cache->nr_io_migrations); |
c6b4fcba JT |
1068 | } |
1069 | ||
651f5fa2 JT |
1070 | static bool discard_or_flush(struct bio *bio) |
1071 | { | |
f73f44eb | 1072 | return bio_op(bio) == REQ_OP_DISCARD || op_is_flush(bio->bi_opf); |
651f5fa2 JT |
1073 | } |
1074 | ||
b29d4986 JT |
1075 | static void calc_discard_block_range(struct cache *cache, struct bio *bio, |
1076 | dm_dblock_t *b, dm_dblock_t *e) | |
c6b4fcba | 1077 | { |
b29d4986 JT |
1078 | sector_t sb = bio->bi_iter.bi_sector; |
1079 | sector_t se = bio_end_sector(bio); | |
651f5fa2 | 1080 | |
b29d4986 | 1081 | *b = to_dblock(dm_sector_div_up(sb, cache->discard_block_size)); |
c6b4fcba | 1082 | |
b29d4986 JT |
1083 | if (se - sb < cache->discard_block_size) |
1084 | *e = *b; | |
1085 | else | |
1086 | *e = to_dblock(block_div(se, cache->discard_block_size)); | |
c6b4fcba JT |
1087 | } |
1088 | ||
b29d4986 | 1089 | /*----------------------------------------------------------------*/ |
651f5fa2 | 1090 | |
b29d4986 | 1091 | static void prevent_background_work(struct cache *cache) |
651f5fa2 | 1092 | { |
b29d4986 JT |
1093 | lockdep_off(); |
1094 | down_write(&cache->background_work_lock); | |
1095 | lockdep_on(); | |
651f5fa2 JT |
1096 | } |
1097 | ||
b29d4986 | 1098 | static void allow_background_work(struct cache *cache) |
c6b4fcba | 1099 | { |
b29d4986 JT |
1100 | lockdep_off(); |
1101 | up_write(&cache->background_work_lock); | |
1102 | lockdep_on(); | |
c6b4fcba JT |
1103 | } |
1104 | ||
b29d4986 | 1105 | static bool background_work_begin(struct cache *cache) |
c6b4fcba | 1106 | { |
b29d4986 | 1107 | bool r; |
c6b4fcba | 1108 | |
b29d4986 JT |
1109 | lockdep_off(); |
1110 | r = down_read_trylock(&cache->background_work_lock); | |
1111 | lockdep_on(); | |
c6b4fcba | 1112 | |
b29d4986 | 1113 | return r; |
c6b4fcba JT |
1114 | } |
1115 | ||
b29d4986 | 1116 | static void background_work_end(struct cache *cache) |
c6b4fcba | 1117 | { |
b29d4986 JT |
1118 | lockdep_off(); |
1119 | up_read(&cache->background_work_lock); | |
1120 | lockdep_on(); | |
1121 | } | |
c6b4fcba | 1122 | |
b29d4986 | 1123 | /*----------------------------------------------------------------*/ |
c6b4fcba | 1124 | |
d1260e2a JT |
1125 | static bool bio_writes_complete_block(struct cache *cache, struct bio *bio) |
1126 | { | |
1127 | return (bio_data_dir(bio) == WRITE) && | |
1128 | (bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT)); | |
1129 | } | |
1130 | ||
1131 | static bool optimisable_bio(struct cache *cache, struct bio *bio, dm_oblock_t block) | |
1132 | { | |
8e3c3827 | 1133 | return writeback_mode(cache) && |
d1260e2a JT |
1134 | (is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio)); |
1135 | } | |
1136 | ||
b29d4986 JT |
1137 | static void quiesce(struct dm_cache_migration *mg, |
1138 | void (*continuation)(struct work_struct *)) | |
1139 | { | |
1140 | init_continuation(&mg->k, continuation); | |
1141 | dm_cell_quiesce_v2(mg->cache->prison, mg->cell, &mg->k.ws); | |
c6b4fcba JT |
1142 | } |
1143 | ||
b29d4986 | 1144 | static struct dm_cache_migration *ws_to_mg(struct work_struct *ws) |
c6b4fcba | 1145 | { |
b29d4986 JT |
1146 | struct continuation *k = container_of(ws, struct continuation, ws); |
1147 | return container_of(k, struct dm_cache_migration, k); | |
c6b4fcba JT |
1148 | } |
1149 | ||
1150 | static void copy_complete(int read_err, unsigned long write_err, void *context) | |
1151 | { | |
b29d4986 | 1152 | struct dm_cache_migration *mg = container_of(context, struct dm_cache_migration, k); |
c6b4fcba JT |
1153 | |
1154 | if (read_err || write_err) | |
4e4cbee9 | 1155 | mg->k.input = BLK_STS_IOERR; |
c6b4fcba | 1156 | |
b29d4986 | 1157 | queue_continuation(mg->cache->wq, &mg->k); |
c6b4fcba JT |
1158 | } |
1159 | ||
7209049d | 1160 | static void copy(struct dm_cache_migration *mg, bool promote) |
c6b4fcba | 1161 | { |
c6b4fcba JT |
1162 | struct dm_io_region o_region, c_region; |
1163 | struct cache *cache = mg->cache; | |
1164 | ||
1165 | o_region.bdev = cache->origin_dev->bdev; | |
b29d4986 | 1166 | o_region.sector = from_oblock(mg->op->oblock) * cache->sectors_per_block; |
c6b4fcba JT |
1167 | o_region.count = cache->sectors_per_block; |
1168 | ||
1169 | c_region.bdev = cache->cache_dev->bdev; | |
b29d4986 | 1170 | c_region.sector = from_cblock(mg->op->cblock) * cache->sectors_per_block; |
c6b4fcba JT |
1171 | c_region.count = cache->sectors_per_block; |
1172 | ||
b29d4986 | 1173 | if (promote) |
7209049d | 1174 | dm_kcopyd_copy(cache->copier, &o_region, 1, &c_region, 0, copy_complete, &mg->k); |
b29d4986 | 1175 | else |
7209049d | 1176 | dm_kcopyd_copy(cache->copier, &c_region, 1, &o_region, 0, copy_complete, &mg->k); |
b29d4986 JT |
1177 | } |
1178 | ||
1179 | static void bio_drop_shared_lock(struct cache *cache, struct bio *bio) | |
1180 | { | |
693b960e | 1181 | struct per_bio_data *pb = get_per_bio_data(bio); |
b29d4986 JT |
1182 | |
1183 | if (pb->cell && dm_cell_put_v2(cache->prison, pb->cell)) | |
1184 | free_prison_cell(cache, pb->cell); | |
1185 | pb->cell = NULL; | |
c6b4fcba JT |
1186 | } |
1187 | ||
4246a0b6 | 1188 | static void overwrite_endio(struct bio *bio) |
c9d28d5d JT |
1189 | { |
1190 | struct dm_cache_migration *mg = bio->bi_private; | |
1191 | struct cache *cache = mg->cache; | |
693b960e | 1192 | struct per_bio_data *pb = get_per_bio_data(bio); |
c9d28d5d | 1193 | |
80ae49aa MS |
1194 | dm_unhook_bio(&pb->hook_info, bio); |
1195 | ||
4e4cbee9 CH |
1196 | if (bio->bi_status) |
1197 | mg->k.input = bio->bi_status; | |
80ae49aa | 1198 | |
693b960e | 1199 | queue_continuation(cache->wq, &mg->k); |
c9d28d5d JT |
1200 | } |
1201 | ||
b29d4986 JT |
1202 | static void overwrite(struct dm_cache_migration *mg, |
1203 | void (*continuation)(struct work_struct *)) | |
c9d28d5d | 1204 | { |
b29d4986 | 1205 | struct bio *bio = mg->overwrite_bio; |
693b960e | 1206 | struct per_bio_data *pb = get_per_bio_data(bio); |
c9d28d5d JT |
1207 | |
1208 | dm_hook_bio(&pb->hook_info, bio, overwrite_endio, mg); | |
8c081b52 JT |
1209 | |
1210 | /* | |
b29d4986 JT |
1211 | * The overwrite bio is part of the copy operation, as such it does |
1212 | * not set/clear discard or dirty flags. | |
8c081b52 | 1213 | */ |
b29d4986 JT |
1214 | if (mg->op->op == POLICY_PROMOTE) |
1215 | remap_to_cache(mg->cache, bio, mg->op->cblock); | |
1216 | else | |
1217 | remap_to_origin(mg->cache, bio); | |
1218 | ||
1219 | init_continuation(&mg->k, continuation); | |
066dbaa3 | 1220 | accounted_request(mg->cache, bio); |
c9d28d5d JT |
1221 | } |
1222 | ||
b29d4986 JT |
1223 | /* |
1224 | * Migration steps: | |
1225 | * | |
1226 | * 1) exclusive lock preventing WRITEs | |
1227 | * 2) quiesce | |
1228 | * 3) copy or issue overwrite bio | |
1229 | * 4) upgrade to exclusive lock preventing READs and WRITEs | |
1230 | * 5) quiesce | |
1231 | * 6) update metadata and commit | |
1232 | * 7) unlock | |
1233 | */ | |
1234 | static void mg_complete(struct dm_cache_migration *mg, bool success) | |
c9d28d5d | 1235 | { |
b29d4986 JT |
1236 | struct bio_list bios; |
1237 | struct cache *cache = mg->cache; | |
1238 | struct policy_work *op = mg->op; | |
1239 | dm_cblock_t cblock = op->cblock; | |
1240 | ||
1241 | if (success) | |
1242 | update_stats(&cache->stats, op->op); | |
1243 | ||
1244 | switch (op->op) { | |
1245 | case POLICY_PROMOTE: | |
1246 | clear_discard(cache, oblock_to_dblock(cache, op->oblock)); | |
1247 | policy_complete_background_work(cache->policy, op, success); | |
1248 | ||
1249 | if (mg->overwrite_bio) { | |
1250 | if (success) | |
1251 | force_set_dirty(cache, cblock); | |
4e4cbee9 CH |
1252 | else if (mg->k.input) |
1253 | mg->overwrite_bio->bi_status = mg->k.input; | |
b29d4986 | 1254 | else |
4e4cbee9 | 1255 | mg->overwrite_bio->bi_status = BLK_STS_IOERR; |
b29d4986 JT |
1256 | bio_endio(mg->overwrite_bio); |
1257 | } else { | |
1258 | if (success) | |
1259 | force_clear_dirty(cache, cblock); | |
1260 | dec_io_migrations(cache); | |
1261 | } | |
1262 | break; | |
1263 | ||
1264 | case POLICY_DEMOTE: | |
1265 | /* | |
1266 | * We clear dirty here to update the nr_dirty counter. | |
1267 | */ | |
1268 | if (success) | |
1269 | force_clear_dirty(cache, cblock); | |
1270 | policy_complete_background_work(cache->policy, op, success); | |
1271 | dec_io_migrations(cache); | |
1272 | break; | |
1273 | ||
1274 | case POLICY_WRITEBACK: | |
1275 | if (success) | |
1276 | force_clear_dirty(cache, cblock); | |
1277 | policy_complete_background_work(cache->policy, op, success); | |
1278 | dec_io_migrations(cache); | |
1279 | break; | |
1280 | } | |
1281 | ||
1282 | bio_list_init(&bios); | |
1283 | if (mg->cell) { | |
1284 | if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios)) | |
1285 | free_prison_cell(cache, mg->cell); | |
1286 | } | |
1287 | ||
1288 | free_migration(mg); | |
1289 | defer_bios(cache, &bios); | |
1290 | wake_migration_worker(cache); | |
1291 | ||
1292 | background_work_end(cache); | |
c9d28d5d JT |
1293 | } |
1294 | ||
b29d4986 | 1295 | static void mg_success(struct work_struct *ws) |
c6b4fcba | 1296 | { |
b29d4986 JT |
1297 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1298 | mg_complete(mg, mg->k.input == 0); | |
c6b4fcba JT |
1299 | } |
1300 | ||
b29d4986 | 1301 | static void mg_update_metadata(struct work_struct *ws) |
7ae34e77 | 1302 | { |
b29d4986 JT |
1303 | int r; |
1304 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
c6b4fcba | 1305 | struct cache *cache = mg->cache; |
b29d4986 | 1306 | struct policy_work *op = mg->op; |
c6b4fcba | 1307 | |
b29d4986 JT |
1308 | switch (op->op) { |
1309 | case POLICY_PROMOTE: | |
1310 | r = dm_cache_insert_mapping(cache->cmd, op->cblock, op->oblock); | |
1311 | if (r) { | |
1312 | DMERR_LIMIT("%s: migration failed; couldn't insert mapping", | |
1313 | cache_device_name(cache)); | |
1314 | metadata_operation_failed(cache, "dm_cache_insert_mapping", r); | |
7ae34e77 | 1315 | |
b29d4986 JT |
1316 | mg_complete(mg, false); |
1317 | return; | |
1318 | } | |
1319 | mg_complete(mg, true); | |
1320 | break; | |
c9d28d5d | 1321 | |
b29d4986 JT |
1322 | case POLICY_DEMOTE: |
1323 | r = dm_cache_remove_mapping(cache->cmd, op->cblock); | |
1324 | if (r) { | |
1325 | DMERR_LIMIT("%s: migration failed; couldn't update on disk metadata", | |
1326 | cache_device_name(cache)); | |
1327 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); | |
c6b4fcba | 1328 | |
b29d4986 | 1329 | mg_complete(mg, false); |
c9d28d5d JT |
1330 | return; |
1331 | } | |
c9d28d5d | 1332 | |
b29d4986 JT |
1333 | /* |
1334 | * It would be nice if we only had to commit when a REQ_FLUSH | |
1335 | * comes through. But there's one scenario that we have to | |
1336 | * look out for: | |
1337 | * | |
1338 | * - vblock x in a cache block | |
1339 | * - domotion occurs | |
1340 | * - cache block gets reallocated and over written | |
1341 | * - crash | |
1342 | * | |
1343 | * When we recover, because there was no commit the cache will | |
1344 | * rollback to having the data for vblock x in the cache block. | |
1345 | * But the cache block has since been overwritten, so it'll end | |
1346 | * up pointing to data that was never in 'x' during the history | |
1347 | * of the device. | |
1348 | * | |
1349 | * To avoid this issue we require a commit as part of the | |
1350 | * demotion operation. | |
1351 | */ | |
1352 | init_continuation(&mg->k, mg_success); | |
1353 | continue_after_commit(&cache->committer, &mg->k); | |
1354 | schedule_commit(&cache->committer); | |
1355 | break; | |
1356 | ||
1357 | case POLICY_WRITEBACK: | |
1358 | mg_complete(mg, true); | |
1359 | break; | |
7ae34e77 | 1360 | } |
c6b4fcba JT |
1361 | } |
1362 | ||
b29d4986 | 1363 | static void mg_update_metadata_after_copy(struct work_struct *ws) |
c6b4fcba | 1364 | { |
b29d4986 JT |
1365 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1366 | ||
1367 | /* | |
1368 | * Did the copy succeed? | |
1369 | */ | |
1370 | if (mg->k.input) | |
1371 | mg_complete(mg, false); | |
c6b4fcba | 1372 | else |
b29d4986 | 1373 | mg_update_metadata(ws); |
c6b4fcba JT |
1374 | } |
1375 | ||
b29d4986 | 1376 | static void mg_upgrade_lock(struct work_struct *ws) |
c6b4fcba | 1377 | { |
b29d4986 JT |
1378 | int r; |
1379 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
c6b4fcba | 1380 | |
b29d4986 JT |
1381 | /* |
1382 | * Did the copy succeed? | |
1383 | */ | |
1384 | if (mg->k.input) | |
1385 | mg_complete(mg, false); | |
c6b4fcba | 1386 | |
c9d28d5d | 1387 | else { |
b29d4986 JT |
1388 | /* |
1389 | * Now we want the lock to prevent both reads and writes. | |
1390 | */ | |
1391 | r = dm_cell_lock_promote_v2(mg->cache->prison, mg->cell, | |
1392 | READ_WRITE_LOCK_LEVEL); | |
1393 | if (r < 0) | |
1394 | mg_complete(mg, false); | |
c6b4fcba | 1395 | |
b29d4986 JT |
1396 | else if (r) |
1397 | quiesce(mg, mg_update_metadata); | |
c6b4fcba | 1398 | |
b29d4986 JT |
1399 | else |
1400 | mg_update_metadata(ws); | |
c9d28d5d | 1401 | } |
c6b4fcba JT |
1402 | } |
1403 | ||
d1260e2a JT |
1404 | static void mg_full_copy(struct work_struct *ws) |
1405 | { | |
1406 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
1407 | struct cache *cache = mg->cache; | |
1408 | struct policy_work *op = mg->op; | |
1409 | bool is_policy_promote = (op->op == POLICY_PROMOTE); | |
1410 | ||
1411 | if ((!is_policy_promote && !is_dirty(cache, op->cblock)) || | |
1412 | is_discarded_oblock(cache, op->oblock)) { | |
1413 | mg_upgrade_lock(ws); | |
1414 | return; | |
1415 | } | |
1416 | ||
1417 | init_continuation(&mg->k, mg_upgrade_lock); | |
7209049d | 1418 | copy(mg, is_policy_promote); |
d1260e2a JT |
1419 | } |
1420 | ||
b29d4986 | 1421 | static void mg_copy(struct work_struct *ws) |
c6b4fcba | 1422 | { |
b29d4986 | 1423 | struct dm_cache_migration *mg = ws_to_mg(ws); |
c6b4fcba | 1424 | |
b29d4986 | 1425 | if (mg->overwrite_bio) { |
d1260e2a JT |
1426 | /* |
1427 | * No exclusive lock was held when we last checked if the bio | |
1428 | * was optimisable. So we have to check again in case things | |
1429 | * have changed (eg, the block may no longer be discarded). | |
1430 | */ | |
1431 | if (!optimisable_bio(mg->cache, mg->overwrite_bio, mg->op->oblock)) { | |
1432 | /* | |
1433 | * Fallback to a real full copy after doing some tidying up. | |
1434 | */ | |
1435 | bool rb = bio_detain_shared(mg->cache, mg->op->oblock, mg->overwrite_bio); | |
1436 | BUG_ON(rb); /* An exclussive lock must _not_ be held for this block */ | |
1437 | mg->overwrite_bio = NULL; | |
1438 | inc_io_migrations(mg->cache); | |
1439 | mg_full_copy(ws); | |
1440 | return; | |
1441 | } | |
1442 | ||
b29d4986 JT |
1443 | /* |
1444 | * It's safe to do this here, even though it's new data | |
1445 | * because all IO has been locked out of the block. | |
1446 | * | |
1447 | * mg_lock_writes() already took READ_WRITE_LOCK_LEVEL | |
1448 | * so _not_ using mg_upgrade_lock() as continutation. | |
1449 | */ | |
1450 | overwrite(mg, mg_update_metadata_after_copy); | |
c6b4fcba | 1451 | |
d1260e2a JT |
1452 | } else |
1453 | mg_full_copy(ws); | |
c6b4fcba JT |
1454 | } |
1455 | ||
b29d4986 | 1456 | static int mg_lock_writes(struct dm_cache_migration *mg) |
c6b4fcba | 1457 | { |
b29d4986 JT |
1458 | int r; |
1459 | struct dm_cell_key_v2 key; | |
c6b4fcba | 1460 | struct cache *cache = mg->cache; |
b29d4986 | 1461 | struct dm_bio_prison_cell_v2 *prealloc; |
c6b4fcba | 1462 | |
b29d4986 | 1463 | prealloc = alloc_prison_cell(cache); |
c6b4fcba | 1464 | |
b29d4986 JT |
1465 | /* |
1466 | * Prevent writes to the block, but allow reads to continue. | |
1467 | * Unless we're using an overwrite bio, in which case we lock | |
1468 | * everything. | |
1469 | */ | |
1470 | build_key(mg->op->oblock, oblock_succ(mg->op->oblock), &key); | |
1471 | r = dm_cell_lock_v2(cache->prison, &key, | |
1472 | mg->overwrite_bio ? READ_WRITE_LOCK_LEVEL : WRITE_LOCK_LEVEL, | |
1473 | prealloc, &mg->cell); | |
1474 | if (r < 0) { | |
1475 | free_prison_cell(cache, prealloc); | |
1476 | mg_complete(mg, false); | |
1477 | return r; | |
1478 | } | |
c6b4fcba | 1479 | |
b29d4986 JT |
1480 | if (mg->cell != prealloc) |
1481 | free_prison_cell(cache, prealloc); | |
c6b4fcba | 1482 | |
b29d4986 JT |
1483 | if (r == 0) |
1484 | mg_copy(&mg->k.ws); | |
1485 | else | |
1486 | quiesce(mg, mg_copy); | |
c6b4fcba | 1487 | |
b29d4986 | 1488 | return 0; |
c6b4fcba JT |
1489 | } |
1490 | ||
b29d4986 | 1491 | static int mg_start(struct cache *cache, struct policy_work *op, struct bio *bio) |
c6b4fcba | 1492 | { |
b29d4986 | 1493 | struct dm_cache_migration *mg; |
c6b4fcba | 1494 | |
b29d4986 JT |
1495 | if (!background_work_begin(cache)) { |
1496 | policy_complete_background_work(cache->policy, op, false); | |
1497 | return -EPERM; | |
1498 | } | |
2ee57d58 | 1499 | |
b29d4986 | 1500 | mg = alloc_migration(cache); |
2ee57d58 | 1501 | |
b29d4986 JT |
1502 | mg->op = op; |
1503 | mg->overwrite_bio = bio; | |
1504 | ||
1505 | if (!bio) | |
1506 | inc_io_migrations(cache); | |
7ae34e77 | 1507 | |
b29d4986 | 1508 | return mg_lock_writes(mg); |
7ae34e77 JT |
1509 | } |
1510 | ||
c6b4fcba | 1511 | /*---------------------------------------------------------------- |
b29d4986 | 1512 | * invalidation processing |
c6b4fcba | 1513 | *--------------------------------------------------------------*/ |
c6b4fcba | 1514 | |
b29d4986 | 1515 | static void invalidate_complete(struct dm_cache_migration *mg, bool success) |
c6b4fcba | 1516 | { |
b29d4986 JT |
1517 | struct bio_list bios; |
1518 | struct cache *cache = mg->cache; | |
c6b4fcba | 1519 | |
b29d4986 JT |
1520 | bio_list_init(&bios); |
1521 | if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios)) | |
1522 | free_prison_cell(cache, mg->cell); | |
c6b4fcba | 1523 | |
b29d4986 JT |
1524 | if (!success && mg->overwrite_bio) |
1525 | bio_io_error(mg->overwrite_bio); | |
c6b4fcba | 1526 | |
b29d4986 JT |
1527 | free_migration(mg); |
1528 | defer_bios(cache, &bios); | |
c6b4fcba | 1529 | |
b29d4986 | 1530 | background_work_end(cache); |
c6b4fcba JT |
1531 | } |
1532 | ||
b29d4986 | 1533 | static void invalidate_completed(struct work_struct *ws) |
c6b4fcba | 1534 | { |
b29d4986 JT |
1535 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1536 | invalidate_complete(mg, !mg->k.input); | |
c6b4fcba JT |
1537 | } |
1538 | ||
b29d4986 | 1539 | static int invalidate_cblock(struct cache *cache, dm_cblock_t cblock) |
651f5fa2 | 1540 | { |
b29d4986 JT |
1541 | int r = policy_invalidate_mapping(cache->policy, cblock); |
1542 | if (!r) { | |
1543 | r = dm_cache_remove_mapping(cache->cmd, cblock); | |
1544 | if (r) { | |
1545 | DMERR_LIMIT("%s: invalidation failed; couldn't update on disk metadata", | |
1546 | cache_device_name(cache)); | |
1547 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); | |
651f5fa2 JT |
1548 | } |
1549 | ||
b29d4986 JT |
1550 | } else if (r == -ENODATA) { |
1551 | /* | |
1552 | * Harmless, already unmapped. | |
1553 | */ | |
1554 | r = 0; | |
651f5fa2 | 1555 | |
b29d4986 JT |
1556 | } else |
1557 | DMERR("%s: policy_invalidate_mapping failed", cache_device_name(cache)); | |
2ee57d58 | 1558 | |
b29d4986 | 1559 | return r; |
651f5fa2 JT |
1560 | } |
1561 | ||
b29d4986 | 1562 | static void invalidate_remove(struct work_struct *ws) |
651f5fa2 | 1563 | { |
b29d4986 JT |
1564 | int r; |
1565 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
1566 | struct cache *cache = mg->cache; | |
651f5fa2 | 1567 | |
b29d4986 JT |
1568 | r = invalidate_cblock(cache, mg->invalidate_cblock); |
1569 | if (r) { | |
1570 | invalidate_complete(mg, false); | |
1571 | return; | |
651f5fa2 | 1572 | } |
9153df74 | 1573 | |
b29d4986 JT |
1574 | init_continuation(&mg->k, invalidate_completed); |
1575 | continue_after_commit(&cache->committer, &mg->k); | |
1576 | remap_to_origin_clear_discard(cache, mg->overwrite_bio, mg->invalidate_oblock); | |
1577 | mg->overwrite_bio = NULL; | |
1578 | schedule_commit(&cache->committer); | |
651f5fa2 JT |
1579 | } |
1580 | ||
b29d4986 | 1581 | static int invalidate_lock(struct dm_cache_migration *mg) |
651f5fa2 | 1582 | { |
b29d4986 JT |
1583 | int r; |
1584 | struct dm_cell_key_v2 key; | |
1585 | struct cache *cache = mg->cache; | |
1586 | struct dm_bio_prison_cell_v2 *prealloc; | |
651f5fa2 | 1587 | |
b29d4986 | 1588 | prealloc = alloc_prison_cell(cache); |
651f5fa2 | 1589 | |
b29d4986 JT |
1590 | build_key(mg->invalidate_oblock, oblock_succ(mg->invalidate_oblock), &key); |
1591 | r = dm_cell_lock_v2(cache->prison, &key, | |
1592 | READ_WRITE_LOCK_LEVEL, prealloc, &mg->cell); | |
1593 | if (r < 0) { | |
1594 | free_prison_cell(cache, prealloc); | |
1595 | invalidate_complete(mg, false); | |
1596 | return r; | |
651f5fa2 | 1597 | } |
9153df74 | 1598 | |
b29d4986 JT |
1599 | if (mg->cell != prealloc) |
1600 | free_prison_cell(cache, prealloc); | |
651f5fa2 | 1601 | |
b29d4986 JT |
1602 | if (r) |
1603 | quiesce(mg, invalidate_remove); | |
651f5fa2 | 1604 | |
b29d4986 JT |
1605 | else { |
1606 | /* | |
1607 | * We can't call invalidate_remove() directly here because we | |
1608 | * might still be in request context. | |
1609 | */ | |
1610 | init_continuation(&mg->k, invalidate_remove); | |
1611 | queue_work(cache->wq, &mg->k.ws); | |
1612 | } | |
fb4100ae | 1613 | |
fb4100ae JT |
1614 | return 0; |
1615 | } | |
1616 | ||
b29d4986 JT |
1617 | static int invalidate_start(struct cache *cache, dm_cblock_t cblock, |
1618 | dm_oblock_t oblock, struct bio *bio) | |
fb4100ae | 1619 | { |
b29d4986 | 1620 | struct dm_cache_migration *mg; |
2ee57d58 | 1621 | |
b29d4986 JT |
1622 | if (!background_work_begin(cache)) |
1623 | return -EPERM; | |
c6b4fcba | 1624 | |
b29d4986 | 1625 | mg = alloc_migration(cache); |
c6b4fcba | 1626 | |
b29d4986 JT |
1627 | mg->overwrite_bio = bio; |
1628 | mg->invalidate_cblock = cblock; | |
1629 | mg->invalidate_oblock = oblock; | |
c6b4fcba | 1630 | |
b29d4986 | 1631 | return invalidate_lock(mg); |
c6b4fcba | 1632 | } |
c6b4fcba | 1633 | |
b29d4986 JT |
1634 | /*---------------------------------------------------------------- |
1635 | * bio processing | |
1636 | *--------------------------------------------------------------*/ | |
c6b4fcba | 1637 | |
b29d4986 JT |
1638 | enum busy { |
1639 | IDLE, | |
b29d4986 JT |
1640 | BUSY |
1641 | }; | |
c6b4fcba | 1642 | |
b29d4986 | 1643 | static enum busy spare_migration_bandwidth(struct cache *cache) |
651f5fa2 | 1644 | { |
701e03e4 | 1645 | bool idle = iot_idle_for(&cache->tracker, HZ); |
a59db676 | 1646 | sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) * |
c6b4fcba | 1647 | cache->sectors_per_block; |
651f5fa2 | 1648 | |
49b7f768 JT |
1649 | if (idle && current_volume <= cache->migration_threshold) |
1650 | return IDLE; | |
b29d4986 | 1651 | else |
49b7f768 | 1652 | return BUSY; |
651f5fa2 JT |
1653 | } |
1654 | ||
c6b4fcba | 1655 | static void inc_hit_counter(struct cache *cache, struct bio *bio) |
c6b4fcba | 1656 | { |
c6b4fcba JT |
1657 | atomic_inc(bio_data_dir(bio) == READ ? |
1658 | &cache->stats.read_hit : &cache->stats.write_hit); | |
c6b4fcba JT |
1659 | } |
1660 | ||
c6b4fcba | 1661 | static void inc_miss_counter(struct cache *cache, struct bio *bio) |
028ae9f7 | 1662 | { |
c6b4fcba JT |
1663 | atomic_inc(bio_data_dir(bio) == READ ? |
1664 | &cache->stats.read_miss : &cache->stats.write_miss); | |
1665 | } | |
028ae9f7 | 1666 | |
fb4100ae | 1667 | /*----------------------------------------------------------------*/ |
028ae9f7 | 1668 | |
b29d4986 JT |
1669 | static int map_bio(struct cache *cache, struct bio *bio, dm_oblock_t block, |
1670 | bool *commit_needed) | |
c6b4fcba | 1671 | { |
b29d4986 JT |
1672 | int r, data_dir; |
1673 | bool rb, background_queued; | |
1674 | dm_cblock_t cblock; | |
c6b4fcba | 1675 | |
b29d4986 | 1676 | *commit_needed = false; |
c6b4fcba | 1677 | |
b29d4986 JT |
1678 | rb = bio_detain_shared(cache, block, bio); |
1679 | if (!rb) { | |
c6b4fcba | 1680 | /* |
b29d4986 JT |
1681 | * An exclusive lock is held for this block, so we have to |
1682 | * wait. We set the commit_needed flag so the current | |
1683 | * transaction will be committed asap, allowing this lock | |
1684 | * to be dropped. | |
c6b4fcba | 1685 | */ |
b29d4986 JT |
1686 | *commit_needed = true; |
1687 | return DM_MAPIO_SUBMITTED; | |
651f5fa2 | 1688 | } |
9153df74 | 1689 | |
b29d4986 | 1690 | data_dir = bio_data_dir(bio); |
651f5fa2 | 1691 | |
b29d4986 JT |
1692 | if (optimisable_bio(cache, bio, block)) { |
1693 | struct policy_work *op = NULL; | |
fb4100ae | 1694 | |
b29d4986 JT |
1695 | r = policy_lookup_with_work(cache->policy, block, &cblock, data_dir, true, &op); |
1696 | if (unlikely(r && r != -ENOENT)) { | |
1697 | DMERR_LIMIT("%s: policy_lookup_with_work() failed with r = %d", | |
1698 | cache_device_name(cache), r); | |
1699 | bio_io_error(bio); | |
1700 | return DM_MAPIO_SUBMITTED; | |
c6b4fcba JT |
1701 | } |
1702 | ||
b29d4986 JT |
1703 | if (r == -ENOENT && op) { |
1704 | bio_drop_shared_lock(cache, bio); | |
1705 | BUG_ON(op->op != POLICY_PROMOTE); | |
1706 | mg_start(cache, op, bio); | |
1707 | return DM_MAPIO_SUBMITTED; | |
1708 | } | |
1709 | } else { | |
1710 | r = policy_lookup(cache->policy, block, &cblock, data_dir, false, &background_queued); | |
1711 | if (unlikely(r && r != -ENOENT)) { | |
1712 | DMERR_LIMIT("%s: policy_lookup() failed with r = %d", | |
1713 | cache_device_name(cache), r); | |
1714 | bio_io_error(bio); | |
1715 | return DM_MAPIO_SUBMITTED; | |
1716 | } | |
c6b4fcba | 1717 | |
b29d4986 JT |
1718 | if (background_queued) |
1719 | wake_migration_worker(cache); | |
c6b4fcba JT |
1720 | } |
1721 | ||
b29d4986 | 1722 | if (r == -ENOENT) { |
693b960e MS |
1723 | struct per_bio_data *pb = get_per_bio_data(bio); |
1724 | ||
b29d4986 JT |
1725 | /* |
1726 | * Miss. | |
1727 | */ | |
1728 | inc_miss_counter(cache, bio); | |
1729 | if (pb->req_nr == 0) { | |
1730 | accounted_begin(cache, bio); | |
1731 | remap_to_origin_clear_discard(cache, bio, block); | |
b29d4986 | 1732 | } else { |
2ee57d58 | 1733 | /* |
b29d4986 JT |
1734 | * This is a duplicate writethrough io that is no |
1735 | * longer needed because the block has been demoted. | |
2ee57d58 | 1736 | */ |
b29d4986 JT |
1737 | bio_endio(bio); |
1738 | return DM_MAPIO_SUBMITTED; | |
1739 | } | |
1740 | } else { | |
1741 | /* | |
1742 | * Hit. | |
1743 | */ | |
1744 | inc_hit_counter(cache, bio); | |
651f5fa2 | 1745 | |
b29d4986 JT |
1746 | /* |
1747 | * Passthrough always maps to the origin, invalidating any | |
1748 | * cache blocks that are written to. | |
1749 | */ | |
8e3c3827 | 1750 | if (passthrough_mode(cache)) { |
2ee57d58 | 1751 | if (bio_data_dir(bio) == WRITE) { |
b29d4986 | 1752 | bio_drop_shared_lock(cache, bio); |
2ee57d58 | 1753 | atomic_inc(&cache->stats.demotion); |
b29d4986 JT |
1754 | invalidate_start(cache, cblock, block, bio); |
1755 | } else | |
2ee57d58 | 1756 | remap_to_origin_clear_discard(cache, bio, block); |
2ee57d58 | 1757 | } else { |
8e3c3827 | 1758 | if (bio_data_dir(bio) == WRITE && writethrough_mode(cache) && |
b29d4986 | 1759 | !is_dirty(cache, cblock)) { |
2df3bae9 | 1760 | remap_to_origin_and_cache(cache, bio, block, cblock); |
b29d4986 JT |
1761 | accounted_begin(cache, bio); |
1762 | } else | |
1763 | remap_to_cache_dirty(cache, bio, block, cblock); | |
2ee57d58 | 1764 | } |
c6b4fcba | 1765 | } |
651f5fa2 | 1766 | |
651f5fa2 | 1767 | /* |
b29d4986 | 1768 | * dm core turns FUA requests into a separate payload and FLUSH req. |
651f5fa2 | 1769 | */ |
b29d4986 | 1770 | if (bio->bi_opf & REQ_FUA) { |
651f5fa2 | 1771 | /* |
b29d4986 JT |
1772 | * issue_after_commit will call accounted_begin a second time. So |
1773 | * we call accounted_complete() to avoid double accounting. | |
651f5fa2 | 1774 | */ |
b29d4986 JT |
1775 | accounted_complete(cache, bio); |
1776 | issue_after_commit(&cache->committer, bio); | |
1777 | *commit_needed = true; | |
1778 | return DM_MAPIO_SUBMITTED; | |
651f5fa2 JT |
1779 | } |
1780 | ||
b29d4986 | 1781 | return DM_MAPIO_REMAPPED; |
651f5fa2 JT |
1782 | } |
1783 | ||
b29d4986 | 1784 | static bool process_bio(struct cache *cache, struct bio *bio) |
c6b4fcba | 1785 | { |
b29d4986 | 1786 | bool commit_needed; |
c6b4fcba | 1787 | |
b29d4986 | 1788 | if (map_bio(cache, bio, get_bio_block(cache, bio), &commit_needed) == DM_MAPIO_REMAPPED) |
ed00aabd | 1789 | submit_bio_noacct(bio); |
c6b4fcba | 1790 | |
b29d4986 | 1791 | return commit_needed; |
c6b4fcba JT |
1792 | } |
1793 | ||
028ae9f7 JT |
1794 | /* |
1795 | * A non-zero return indicates read_only or fail_io mode. | |
1796 | */ | |
1797 | static int commit(struct cache *cache, bool clean_shutdown) | |
e2e74d61 | 1798 | { |
028ae9f7 | 1799 | int r; |
e2e74d61 | 1800 | |
028ae9f7 JT |
1801 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
1802 | return -EINVAL; | |
e2e74d61 | 1803 | |
028ae9f7 JT |
1804 | atomic_inc(&cache->stats.commit_count); |
1805 | r = dm_cache_commit(cache->cmd, clean_shutdown); | |
1806 | if (r) | |
1807 | metadata_operation_failed(cache, "dm_cache_commit", r); | |
e2e74d61 | 1808 | |
028ae9f7 | 1809 | return r; |
e2e74d61 JT |
1810 | } |
1811 | ||
b29d4986 JT |
1812 | /* |
1813 | * Used by the batcher. | |
1814 | */ | |
4e4cbee9 | 1815 | static blk_status_t commit_op(void *context) |
c6b4fcba | 1816 | { |
b29d4986 | 1817 | struct cache *cache = context; |
c6b4fcba | 1818 | |
b29d4986 | 1819 | if (dm_cache_changed_this_transaction(cache->cmd)) |
4e4cbee9 | 1820 | return errno_to_blk_status(commit(cache, false)); |
c6b4fcba | 1821 | |
b29d4986 | 1822 | return 0; |
c6b4fcba JT |
1823 | } |
1824 | ||
b29d4986 | 1825 | /*----------------------------------------------------------------*/ |
65790ff9 | 1826 | |
b29d4986 | 1827 | static bool process_flush_bio(struct cache *cache, struct bio *bio) |
65790ff9 | 1828 | { |
693b960e | 1829 | struct per_bio_data *pb = get_per_bio_data(bio); |
65790ff9 | 1830 | |
b29d4986 JT |
1831 | if (!pb->req_nr) |
1832 | remap_to_origin(cache, bio); | |
1833 | else | |
1834 | remap_to_cache(cache, bio, 0); | |
65790ff9 | 1835 | |
b29d4986 JT |
1836 | issue_after_commit(&cache->committer, bio); |
1837 | return true; | |
65790ff9 JT |
1838 | } |
1839 | ||
b29d4986 | 1840 | static bool process_discard_bio(struct cache *cache, struct bio *bio) |
65790ff9 | 1841 | { |
b29d4986 | 1842 | dm_dblock_t b, e; |
65790ff9 | 1843 | |
b29d4986 JT |
1844 | // FIXME: do we need to lock the region? Or can we just assume the |
1845 | // user wont be so foolish as to issue discard concurrently with | |
1846 | // other IO? | |
1847 | calc_discard_block_range(cache, bio, &b, &e); | |
1848 | while (b != e) { | |
1849 | set_discard(cache, b); | |
1850 | b = to_dblock(from_dblock(b) + 1); | |
651f5fa2 | 1851 | } |
65790ff9 | 1852 | |
de7180ff MS |
1853 | if (cache->features.discard_passdown) { |
1854 | remap_to_origin(cache, bio); | |
ed00aabd | 1855 | submit_bio_noacct(bio); |
de7180ff MS |
1856 | } else |
1857 | bio_endio(bio); | |
65790ff9 | 1858 | |
b29d4986 | 1859 | return false; |
c6b4fcba JT |
1860 | } |
1861 | ||
b29d4986 | 1862 | static void process_deferred_bios(struct work_struct *ws) |
66cb1910 | 1863 | { |
b29d4986 | 1864 | struct cache *cache = container_of(ws, struct cache, deferred_bio_worker); |
66cb1910 | 1865 | |
b29d4986 | 1866 | bool commit_needed = false; |
c6b4fcba JT |
1867 | struct bio_list bios; |
1868 | struct bio *bio; | |
66cb1910 | 1869 | |
c6b4fcba | 1870 | bio_list_init(&bios); |
c6b4fcba | 1871 | |
26b924b9 | 1872 | spin_lock_irq(&cache->lock); |
b29d4986 JT |
1873 | bio_list_merge(&bios, &cache->deferred_bios); |
1874 | bio_list_init(&cache->deferred_bios); | |
26b924b9 | 1875 | spin_unlock_irq(&cache->lock); |
c6b4fcba | 1876 | |
b29d4986 JT |
1877 | while ((bio = bio_list_pop(&bios))) { |
1878 | if (bio->bi_opf & REQ_PREFLUSH) | |
1879 | commit_needed = process_flush_bio(cache, bio) || commit_needed; | |
c6b4fcba | 1880 | |
b29d4986 JT |
1881 | else if (bio_op(bio) == REQ_OP_DISCARD) |
1882 | commit_needed = process_discard_bio(cache, bio) || commit_needed; | |
1883 | ||
1884 | else | |
1885 | commit_needed = process_bio(cache, bio) || commit_needed; | |
1886 | } | |
1887 | ||
1888 | if (commit_needed) | |
1889 | schedule_commit(&cache->committer); | |
c6b4fcba JT |
1890 | } |
1891 | ||
c6b4fcba JT |
1892 | /*---------------------------------------------------------------- |
1893 | * Main worker loop | |
1894 | *--------------------------------------------------------------*/ | |
651f5fa2 JT |
1895 | |
1896 | static void requeue_deferred_bios(struct cache *cache) | |
c6b4fcba JT |
1897 | { |
1898 | struct bio *bio; | |
1899 | struct bio_list bios; | |
1900 | ||
1901 | bio_list_init(&bios); | |
1902 | bio_list_merge(&bios, &cache->deferred_bios); | |
1903 | bio_list_init(&cache->deferred_bios); | |
1904 | ||
4246a0b6 | 1905 | while ((bio = bio_list_pop(&bios))) { |
4e4cbee9 | 1906 | bio->bi_status = BLK_STS_DM_REQUEUE; |
4246a0b6 CH |
1907 | bio_endio(bio); |
1908 | } | |
c6b4fcba JT |
1909 | } |
1910 | ||
c6b4fcba JT |
1911 | /* |
1912 | * We want to commit periodically so that not too much | |
1913 | * unwritten metadata builds up. | |
1914 | */ | |
1915 | static void do_waker(struct work_struct *ws) | |
1916 | { | |
1917 | struct cache *cache = container_of(to_delayed_work(ws), struct cache, waker); | |
b29d4986 | 1918 | |
fba10109 | 1919 | policy_tick(cache->policy, true); |
b29d4986 JT |
1920 | wake_migration_worker(cache); |
1921 | schedule_commit(&cache->committer); | |
c6b4fcba JT |
1922 | queue_delayed_work(cache->wq, &cache->waker, COMMIT_PERIOD); |
1923 | } | |
1924 | ||
b29d4986 | 1925 | static void check_migrations(struct work_struct *ws) |
c6b4fcba | 1926 | { |
b29d4986 JT |
1927 | int r; |
1928 | struct policy_work *op; | |
1929 | struct cache *cache = container_of(ws, struct cache, migration_worker); | |
1930 | enum busy b; | |
c6b4fcba | 1931 | |
b29d4986 JT |
1932 | for (;;) { |
1933 | b = spare_migration_bandwidth(cache); | |
c6b4fcba | 1934 | |
b29d4986 JT |
1935 | r = policy_get_background_work(cache->policy, b == IDLE, &op); |
1936 | if (r == -ENODATA) | |
1937 | break; | |
1938 | ||
1939 | if (r) { | |
1940 | DMERR_LIMIT("%s: policy_background_work failed", | |
1941 | cache_device_name(cache)); | |
1942 | break; | |
1943 | } | |
1944 | ||
1945 | r = mg_start(cache, op, NULL); | |
1946 | if (r) | |
1947 | break; | |
1948 | } | |
c6b4fcba JT |
1949 | } |
1950 | ||
1951 | /*---------------------------------------------------------------- | |
1952 | * Target methods | |
1953 | *--------------------------------------------------------------*/ | |
1954 | ||
1955 | /* | |
1956 | * This function gets called on the error paths of the constructor, so we | |
1957 | * have to cope with a partially initialised struct. | |
1958 | */ | |
1959 | static void destroy(struct cache *cache) | |
1960 | { | |
1961 | unsigned i; | |
1962 | ||
6f1c819c | 1963 | mempool_exit(&cache->migration_pool); |
c6b4fcba | 1964 | |
c6b4fcba | 1965 | if (cache->prison) |
b29d4986 | 1966 | dm_bio_prison_destroy_v2(cache->prison); |
c6b4fcba JT |
1967 | |
1968 | if (cache->wq) | |
1969 | destroy_workqueue(cache->wq); | |
1970 | ||
1971 | if (cache->dirty_bitset) | |
1972 | free_bitset(cache->dirty_bitset); | |
1973 | ||
1974 | if (cache->discard_bitset) | |
1975 | free_bitset(cache->discard_bitset); | |
1976 | ||
1977 | if (cache->copier) | |
1978 | dm_kcopyd_client_destroy(cache->copier); | |
1979 | ||
1980 | if (cache->cmd) | |
1981 | dm_cache_metadata_close(cache->cmd); | |
1982 | ||
1983 | if (cache->metadata_dev) | |
1984 | dm_put_device(cache->ti, cache->metadata_dev); | |
1985 | ||
1986 | if (cache->origin_dev) | |
1987 | dm_put_device(cache->ti, cache->origin_dev); | |
1988 | ||
1989 | if (cache->cache_dev) | |
1990 | dm_put_device(cache->ti, cache->cache_dev); | |
1991 | ||
1992 | if (cache->policy) | |
1993 | dm_cache_policy_destroy(cache->policy); | |
1994 | ||
1995 | for (i = 0; i < cache->nr_ctr_args ; i++) | |
1996 | kfree(cache->ctr_args[i]); | |
1997 | kfree(cache->ctr_args); | |
1998 | ||
6f1c819c | 1999 | bioset_exit(&cache->bs); |
2df3bae9 | 2000 | |
c6b4fcba JT |
2001 | kfree(cache); |
2002 | } | |
2003 | ||
2004 | static void cache_dtr(struct dm_target *ti) | |
2005 | { | |
2006 | struct cache *cache = ti->private; | |
2007 | ||
2008 | destroy(cache); | |
2009 | } | |
2010 | ||
2011 | static sector_t get_dev_size(struct dm_dev *dev) | |
2012 | { | |
2013 | return i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
2014 | } | |
2015 | ||
2016 | /*----------------------------------------------------------------*/ | |
2017 | ||
2018 | /* | |
2019 | * Construct a cache device mapping. | |
2020 | * | |
2021 | * cache <metadata dev> <cache dev> <origin dev> <block size> | |
2022 | * <#feature args> [<feature arg>]* | |
2023 | * <policy> <#policy args> [<policy arg>]* | |
2024 | * | |
2025 | * metadata dev : fast device holding the persistent metadata | |
2026 | * cache dev : fast device holding cached data blocks | |
2027 | * origin dev : slow device holding original data blocks | |
2028 | * block size : cache unit size in sectors | |
2029 | * | |
2030 | * #feature args : number of feature arguments passed | |
2031 | * feature args : writethrough. (The default is writeback.) | |
2032 | * | |
2033 | * policy : the replacement policy to use | |
2034 | * #policy args : an even number of policy arguments corresponding | |
2035 | * to key/value pairs passed to the policy | |
2036 | * policy args : key/value pairs passed to the policy | |
2037 | * E.g. 'sequential_threshold 1024' | |
2038 | * See cache-policies.txt for details. | |
2039 | * | |
2040 | * Optional feature arguments are: | |
2041 | * writethrough : write through caching that prohibits cache block | |
2042 | * content from being different from origin block content. | |
2043 | * Without this argument, the default behaviour is to write | |
2044 | * back cache block contents later for performance reasons, | |
2045 | * so they may differ from the corresponding origin blocks. | |
2046 | */ | |
2047 | struct cache_args { | |
2048 | struct dm_target *ti; | |
2049 | ||
2050 | struct dm_dev *metadata_dev; | |
2051 | ||
2052 | struct dm_dev *cache_dev; | |
2053 | sector_t cache_sectors; | |
2054 | ||
2055 | struct dm_dev *origin_dev; | |
2056 | sector_t origin_sectors; | |
2057 | ||
2058 | uint32_t block_size; | |
2059 | ||
2060 | const char *policy_name; | |
2061 | int policy_argc; | |
2062 | const char **policy_argv; | |
2063 | ||
2064 | struct cache_features features; | |
2065 | }; | |
2066 | ||
2067 | static void destroy_cache_args(struct cache_args *ca) | |
2068 | { | |
2069 | if (ca->metadata_dev) | |
2070 | dm_put_device(ca->ti, ca->metadata_dev); | |
2071 | ||
2072 | if (ca->cache_dev) | |
2073 | dm_put_device(ca->ti, ca->cache_dev); | |
2074 | ||
2075 | if (ca->origin_dev) | |
2076 | dm_put_device(ca->ti, ca->origin_dev); | |
2077 | ||
2078 | kfree(ca); | |
2079 | } | |
2080 | ||
2081 | static bool at_least_one_arg(struct dm_arg_set *as, char **error) | |
2082 | { | |
2083 | if (!as->argc) { | |
2084 | *error = "Insufficient args"; | |
2085 | return false; | |
2086 | } | |
2087 | ||
2088 | return true; | |
2089 | } | |
2090 | ||
2091 | static int parse_metadata_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2092 | char **error) | |
2093 | { | |
2094 | int r; | |
2095 | sector_t metadata_dev_size; | |
2096 | char b[BDEVNAME_SIZE]; | |
2097 | ||
2098 | if (!at_least_one_arg(as, error)) | |
2099 | return -EINVAL; | |
2100 | ||
2101 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2102 | &ca->metadata_dev); | |
2103 | if (r) { | |
2104 | *error = "Error opening metadata device"; | |
2105 | return r; | |
2106 | } | |
2107 | ||
2108 | metadata_dev_size = get_dev_size(ca->metadata_dev); | |
2109 | if (metadata_dev_size > DM_CACHE_METADATA_MAX_SECTORS_WARNING) | |
2110 | DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.", | |
2111 | bdevname(ca->metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS); | |
2112 | ||
2113 | return 0; | |
2114 | } | |
2115 | ||
2116 | static int parse_cache_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2117 | char **error) | |
2118 | { | |
2119 | int r; | |
2120 | ||
2121 | if (!at_least_one_arg(as, error)) | |
2122 | return -EINVAL; | |
2123 | ||
2124 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2125 | &ca->cache_dev); | |
2126 | if (r) { | |
2127 | *error = "Error opening cache device"; | |
2128 | return r; | |
2129 | } | |
2130 | ca->cache_sectors = get_dev_size(ca->cache_dev); | |
2131 | ||
2132 | return 0; | |
2133 | } | |
2134 | ||
2135 | static int parse_origin_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2136 | char **error) | |
2137 | { | |
2138 | int r; | |
2139 | ||
2140 | if (!at_least_one_arg(as, error)) | |
2141 | return -EINVAL; | |
2142 | ||
2143 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2144 | &ca->origin_dev); | |
2145 | if (r) { | |
2146 | *error = "Error opening origin device"; | |
2147 | return r; | |
2148 | } | |
2149 | ||
2150 | ca->origin_sectors = get_dev_size(ca->origin_dev); | |
2151 | if (ca->ti->len > ca->origin_sectors) { | |
2152 | *error = "Device size larger than cached device"; | |
2153 | return -EINVAL; | |
2154 | } | |
2155 | ||
2156 | return 0; | |
2157 | } | |
2158 | ||
2159 | static int parse_block_size(struct cache_args *ca, struct dm_arg_set *as, | |
2160 | char **error) | |
2161 | { | |
05473044 | 2162 | unsigned long block_size; |
c6b4fcba JT |
2163 | |
2164 | if (!at_least_one_arg(as, error)) | |
2165 | return -EINVAL; | |
2166 | ||
05473044 MS |
2167 | if (kstrtoul(dm_shift_arg(as), 10, &block_size) || !block_size || |
2168 | block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS || | |
2169 | block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS || | |
2170 | block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) { | |
c6b4fcba JT |
2171 | *error = "Invalid data block size"; |
2172 | return -EINVAL; | |
2173 | } | |
2174 | ||
05473044 | 2175 | if (block_size > ca->cache_sectors) { |
c6b4fcba JT |
2176 | *error = "Data block size is larger than the cache device"; |
2177 | return -EINVAL; | |
2178 | } | |
2179 | ||
05473044 | 2180 | ca->block_size = block_size; |
c6b4fcba JT |
2181 | |
2182 | return 0; | |
2183 | } | |
2184 | ||
2185 | static void init_features(struct cache_features *cf) | |
2186 | { | |
2187 | cf->mode = CM_WRITE; | |
2ee57d58 | 2188 | cf->io_mode = CM_IO_WRITEBACK; |
629d0a8a | 2189 | cf->metadata_version = 1; |
de7180ff | 2190 | cf->discard_passdown = true; |
c6b4fcba JT |
2191 | } |
2192 | ||
2193 | static int parse_features(struct cache_args *ca, struct dm_arg_set *as, | |
2194 | char **error) | |
2195 | { | |
5916a22b | 2196 | static const struct dm_arg _args[] = { |
de7180ff | 2197 | {0, 3, "Invalid number of cache feature arguments"}, |
c6b4fcba JT |
2198 | }; |
2199 | ||
af9313c3 | 2200 | int r, mode_ctr = 0; |
c6b4fcba JT |
2201 | unsigned argc; |
2202 | const char *arg; | |
2203 | struct cache_features *cf = &ca->features; | |
2204 | ||
2205 | init_features(cf); | |
2206 | ||
2207 | r = dm_read_arg_group(_args, as, &argc, error); | |
2208 | if (r) | |
2209 | return -EINVAL; | |
2210 | ||
2211 | while (argc--) { | |
2212 | arg = dm_shift_arg(as); | |
2213 | ||
af9313c3 | 2214 | if (!strcasecmp(arg, "writeback")) { |
2ee57d58 | 2215 | cf->io_mode = CM_IO_WRITEBACK; |
af9313c3 JP |
2216 | mode_ctr++; |
2217 | } | |
c6b4fcba | 2218 | |
af9313c3 | 2219 | else if (!strcasecmp(arg, "writethrough")) { |
2ee57d58 | 2220 | cf->io_mode = CM_IO_WRITETHROUGH; |
af9313c3 JP |
2221 | mode_ctr++; |
2222 | } | |
2ee57d58 | 2223 | |
af9313c3 | 2224 | else if (!strcasecmp(arg, "passthrough")) { |
2ee57d58 | 2225 | cf->io_mode = CM_IO_PASSTHROUGH; |
af9313c3 JP |
2226 | mode_ctr++; |
2227 | } | |
c6b4fcba | 2228 | |
629d0a8a JT |
2229 | else if (!strcasecmp(arg, "metadata2")) |
2230 | cf->metadata_version = 2; | |
2231 | ||
de7180ff MS |
2232 | else if (!strcasecmp(arg, "no_discard_passdown")) |
2233 | cf->discard_passdown = false; | |
2234 | ||
c6b4fcba JT |
2235 | else { |
2236 | *error = "Unrecognised cache feature requested"; | |
2237 | return -EINVAL; | |
2238 | } | |
2239 | } | |
2240 | ||
af9313c3 JP |
2241 | if (mode_ctr > 1) { |
2242 | *error = "Duplicate cache io_mode features requested"; | |
2243 | return -EINVAL; | |
2244 | } | |
2245 | ||
c6b4fcba JT |
2246 | return 0; |
2247 | } | |
2248 | ||
2249 | static int parse_policy(struct cache_args *ca, struct dm_arg_set *as, | |
2250 | char **error) | |
2251 | { | |
5916a22b | 2252 | static const struct dm_arg _args[] = { |
c6b4fcba JT |
2253 | {0, 1024, "Invalid number of policy arguments"}, |
2254 | }; | |
2255 | ||
2256 | int r; | |
2257 | ||
2258 | if (!at_least_one_arg(as, error)) | |
2259 | return -EINVAL; | |
2260 | ||
2261 | ca->policy_name = dm_shift_arg(as); | |
2262 | ||
2263 | r = dm_read_arg_group(_args, as, &ca->policy_argc, error); | |
2264 | if (r) | |
2265 | return -EINVAL; | |
2266 | ||
2267 | ca->policy_argv = (const char **)as->argv; | |
2268 | dm_consume_args(as, ca->policy_argc); | |
2269 | ||
2270 | return 0; | |
2271 | } | |
2272 | ||
2273 | static int parse_cache_args(struct cache_args *ca, int argc, char **argv, | |
2274 | char **error) | |
2275 | { | |
2276 | int r; | |
2277 | struct dm_arg_set as; | |
2278 | ||
2279 | as.argc = argc; | |
2280 | as.argv = argv; | |
2281 | ||
2282 | r = parse_metadata_dev(ca, &as, error); | |
2283 | if (r) | |
2284 | return r; | |
2285 | ||
2286 | r = parse_cache_dev(ca, &as, error); | |
2287 | if (r) | |
2288 | return r; | |
2289 | ||
2290 | r = parse_origin_dev(ca, &as, error); | |
2291 | if (r) | |
2292 | return r; | |
2293 | ||
2294 | r = parse_block_size(ca, &as, error); | |
2295 | if (r) | |
2296 | return r; | |
2297 | ||
2298 | r = parse_features(ca, &as, error); | |
2299 | if (r) | |
2300 | return r; | |
2301 | ||
2302 | r = parse_policy(ca, &as, error); | |
2303 | if (r) | |
2304 | return r; | |
2305 | ||
2306 | return 0; | |
2307 | } | |
2308 | ||
2309 | /*----------------------------------------------------------------*/ | |
2310 | ||
2311 | static struct kmem_cache *migration_cache; | |
2312 | ||
2c73c471 AK |
2313 | #define NOT_CORE_OPTION 1 |
2314 | ||
2f14f4b5 | 2315 | static int process_config_option(struct cache *cache, const char *key, const char *value) |
2c73c471 AK |
2316 | { |
2317 | unsigned long tmp; | |
2318 | ||
2f14f4b5 JT |
2319 | if (!strcasecmp(key, "migration_threshold")) { |
2320 | if (kstrtoul(value, 10, &tmp)) | |
2c73c471 AK |
2321 | return -EINVAL; |
2322 | ||
2323 | cache->migration_threshold = tmp; | |
2324 | return 0; | |
2325 | } | |
2326 | ||
2327 | return NOT_CORE_OPTION; | |
2328 | } | |
2329 | ||
2f14f4b5 JT |
2330 | static int set_config_value(struct cache *cache, const char *key, const char *value) |
2331 | { | |
2332 | int r = process_config_option(cache, key, value); | |
2333 | ||
2334 | if (r == NOT_CORE_OPTION) | |
2335 | r = policy_set_config_value(cache->policy, key, value); | |
2336 | ||
2337 | if (r) | |
2338 | DMWARN("bad config value for %s: %s", key, value); | |
2339 | ||
2340 | return r; | |
2341 | } | |
2342 | ||
2343 | static int set_config_values(struct cache *cache, int argc, const char **argv) | |
c6b4fcba JT |
2344 | { |
2345 | int r = 0; | |
2346 | ||
2347 | if (argc & 1) { | |
2348 | DMWARN("Odd number of policy arguments given but they should be <key> <value> pairs."); | |
2349 | return -EINVAL; | |
2350 | } | |
2351 | ||
2352 | while (argc) { | |
2f14f4b5 JT |
2353 | r = set_config_value(cache, argv[0], argv[1]); |
2354 | if (r) | |
2355 | break; | |
c6b4fcba JT |
2356 | |
2357 | argc -= 2; | |
2358 | argv += 2; | |
2359 | } | |
2360 | ||
2361 | return r; | |
2362 | } | |
2363 | ||
2364 | static int create_cache_policy(struct cache *cache, struct cache_args *ca, | |
2365 | char **error) | |
2366 | { | |
4cb3e1db MP |
2367 | struct dm_cache_policy *p = dm_cache_policy_create(ca->policy_name, |
2368 | cache->cache_size, | |
2369 | cache->origin_sectors, | |
2370 | cache->sectors_per_block); | |
2371 | if (IS_ERR(p)) { | |
c6b4fcba | 2372 | *error = "Error creating cache's policy"; |
4cb3e1db | 2373 | return PTR_ERR(p); |
c6b4fcba | 2374 | } |
4cb3e1db | 2375 | cache->policy = p; |
b29d4986 | 2376 | BUG_ON(!cache->policy); |
c6b4fcba | 2377 | |
2f14f4b5 | 2378 | return 0; |
c6b4fcba JT |
2379 | } |
2380 | ||
08b18451 | 2381 | /* |
2bb812df JT |
2382 | * We want the discard block size to be at least the size of the cache |
2383 | * block size and have no more than 2^14 discard blocks across the origin. | |
08b18451 JT |
2384 | */ |
2385 | #define MAX_DISCARD_BLOCKS (1 << 14) | |
2386 | ||
2387 | static bool too_many_discard_blocks(sector_t discard_block_size, | |
2388 | sector_t origin_size) | |
2389 | { | |
2390 | (void) sector_div(origin_size, discard_block_size); | |
2391 | ||
2392 | return origin_size > MAX_DISCARD_BLOCKS; | |
2393 | } | |
2394 | ||
2395 | static sector_t calculate_discard_block_size(sector_t cache_block_size, | |
2396 | sector_t origin_size) | |
2397 | { | |
2bb812df | 2398 | sector_t discard_block_size = cache_block_size; |
08b18451 JT |
2399 | |
2400 | if (origin_size) | |
2401 | while (too_many_discard_blocks(discard_block_size, origin_size)) | |
2402 | discard_block_size *= 2; | |
2403 | ||
2404 | return discard_block_size; | |
2405 | } | |
2406 | ||
d1d9220c JT |
2407 | static void set_cache_size(struct cache *cache, dm_cblock_t size) |
2408 | { | |
2409 | dm_block_t nr_blocks = from_cblock(size); | |
2410 | ||
2411 | if (nr_blocks > (1 << 20) && cache->cache_size != size) | |
2412 | DMWARN_LIMIT("You have created a cache device with a lot of individual cache blocks (%llu)\n" | |
2413 | "All these mappings can consume a lot of kernel memory, and take some time to read/write.\n" | |
2414 | "Please consider increasing the cache block size to reduce the overall cache block count.", | |
2415 | (unsigned long long) nr_blocks); | |
2416 | ||
2417 | cache->cache_size = size; | |
2418 | } | |
2419 | ||
f8350daf | 2420 | #define DEFAULT_MIGRATION_THRESHOLD 2048 |
c6b4fcba | 2421 | |
c6b4fcba JT |
2422 | static int cache_create(struct cache_args *ca, struct cache **result) |
2423 | { | |
2424 | int r = 0; | |
2425 | char **error = &ca->ti->error; | |
2426 | struct cache *cache; | |
2427 | struct dm_target *ti = ca->ti; | |
2428 | dm_block_t origin_blocks; | |
2429 | struct dm_cache_metadata *cmd; | |
2430 | bool may_format = ca->features.mode == CM_WRITE; | |
2431 | ||
2432 | cache = kzalloc(sizeof(*cache), GFP_KERNEL); | |
2433 | if (!cache) | |
2434 | return -ENOMEM; | |
2435 | ||
2436 | cache->ti = ca->ti; | |
2437 | ti->private = cache; | |
c6b4fcba JT |
2438 | ti->num_flush_bios = 2; |
2439 | ti->flush_supported = true; | |
2440 | ||
2441 | ti->num_discard_bios = 1; | |
2442 | ti->discards_supported = true; | |
c6b4fcba | 2443 | |
693b960e | 2444 | ti->per_io_data_size = sizeof(struct per_bio_data); |
c6b4fcba | 2445 | |
693b960e | 2446 | cache->features = ca->features; |
2df3bae9 MS |
2447 | if (writethrough_mode(cache)) { |
2448 | /* Create bioset for writethrough bios issued to origin */ | |
6f1c819c KO |
2449 | r = bioset_init(&cache->bs, BIO_POOL_SIZE, 0, 0); |
2450 | if (r) | |
2df3bae9 MS |
2451 | goto bad; |
2452 | } | |
2453 | ||
c6b4fcba JT |
2454 | cache->metadata_dev = ca->metadata_dev; |
2455 | cache->origin_dev = ca->origin_dev; | |
2456 | cache->cache_dev = ca->cache_dev; | |
2457 | ||
2458 | ca->metadata_dev = ca->origin_dev = ca->cache_dev = NULL; | |
2459 | ||
c6b4fcba | 2460 | origin_blocks = cache->origin_sectors = ca->origin_sectors; |
414dd67d | 2461 | origin_blocks = block_div(origin_blocks, ca->block_size); |
c6b4fcba JT |
2462 | cache->origin_blocks = to_oblock(origin_blocks); |
2463 | ||
2464 | cache->sectors_per_block = ca->block_size; | |
2465 | if (dm_set_target_max_io_len(ti, cache->sectors_per_block)) { | |
2466 | r = -EINVAL; | |
2467 | goto bad; | |
2468 | } | |
2469 | ||
2470 | if (ca->block_size & (ca->block_size - 1)) { | |
2471 | dm_block_t cache_size = ca->cache_sectors; | |
2472 | ||
2473 | cache->sectors_per_block_shift = -1; | |
414dd67d | 2474 | cache_size = block_div(cache_size, ca->block_size); |
d1d9220c | 2475 | set_cache_size(cache, to_cblock(cache_size)); |
c6b4fcba JT |
2476 | } else { |
2477 | cache->sectors_per_block_shift = __ffs(ca->block_size); | |
d1d9220c | 2478 | set_cache_size(cache, to_cblock(ca->cache_sectors >> cache->sectors_per_block_shift)); |
c6b4fcba JT |
2479 | } |
2480 | ||
2481 | r = create_cache_policy(cache, ca, error); | |
2482 | if (r) | |
2483 | goto bad; | |
2f14f4b5 | 2484 | |
c6b4fcba | 2485 | cache->policy_nr_args = ca->policy_argc; |
2f14f4b5 JT |
2486 | cache->migration_threshold = DEFAULT_MIGRATION_THRESHOLD; |
2487 | ||
2488 | r = set_config_values(cache, ca->policy_argc, ca->policy_argv); | |
2489 | if (r) { | |
2490 | *error = "Error setting cache policy's config values"; | |
2491 | goto bad; | |
2492 | } | |
c6b4fcba JT |
2493 | |
2494 | cmd = dm_cache_metadata_open(cache->metadata_dev->bdev, | |
2495 | ca->block_size, may_format, | |
629d0a8a JT |
2496 | dm_cache_policy_get_hint_size(cache->policy), |
2497 | ca->features.metadata_version); | |
c6b4fcba JT |
2498 | if (IS_ERR(cmd)) { |
2499 | *error = "Error creating metadata object"; | |
2500 | r = PTR_ERR(cmd); | |
2501 | goto bad; | |
2502 | } | |
2503 | cache->cmd = cmd; | |
028ae9f7 JT |
2504 | set_cache_mode(cache, CM_WRITE); |
2505 | if (get_cache_mode(cache) != CM_WRITE) { | |
2506 | *error = "Unable to get write access to metadata, please check/repair metadata."; | |
2507 | r = -EINVAL; | |
2508 | goto bad; | |
2509 | } | |
c6b4fcba | 2510 | |
8e3c3827 | 2511 | if (passthrough_mode(cache)) { |
2ee57d58 JT |
2512 | bool all_clean; |
2513 | ||
2514 | r = dm_cache_metadata_all_clean(cache->cmd, &all_clean); | |
2515 | if (r) { | |
2516 | *error = "dm_cache_metadata_all_clean() failed"; | |
2517 | goto bad; | |
2518 | } | |
2519 | ||
2520 | if (!all_clean) { | |
2521 | *error = "Cannot enter passthrough mode unless all blocks are clean"; | |
2522 | r = -EINVAL; | |
2523 | goto bad; | |
2524 | } | |
b29d4986 JT |
2525 | |
2526 | policy_allow_migrations(cache->policy, false); | |
2ee57d58 JT |
2527 | } |
2528 | ||
c6b4fcba JT |
2529 | spin_lock_init(&cache->lock); |
2530 | bio_list_init(&cache->deferred_bios); | |
a59db676 JT |
2531 | atomic_set(&cache->nr_allocated_migrations, 0); |
2532 | atomic_set(&cache->nr_io_migrations, 0); | |
c6b4fcba JT |
2533 | init_waitqueue_head(&cache->migration_wait); |
2534 | ||
fa4d683a | 2535 | r = -ENOMEM; |
44fa816b | 2536 | atomic_set(&cache->nr_dirty, 0); |
c6b4fcba JT |
2537 | cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size)); |
2538 | if (!cache->dirty_bitset) { | |
2539 | *error = "could not allocate dirty bitset"; | |
2540 | goto bad; | |
2541 | } | |
2542 | clear_bitset(cache->dirty_bitset, from_cblock(cache->cache_size)); | |
2543 | ||
08b18451 JT |
2544 | cache->discard_block_size = |
2545 | calculate_discard_block_size(cache->sectors_per_block, | |
2546 | cache->origin_sectors); | |
2572629a JT |
2547 | cache->discard_nr_blocks = to_dblock(dm_sector_div_up(cache->origin_sectors, |
2548 | cache->discard_block_size)); | |
1bad9bc4 | 2549 | cache->discard_bitset = alloc_bitset(from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2550 | if (!cache->discard_bitset) { |
2551 | *error = "could not allocate discard bitset"; | |
2552 | goto bad; | |
2553 | } | |
1bad9bc4 | 2554 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2555 | |
2556 | cache->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle); | |
2557 | if (IS_ERR(cache->copier)) { | |
2558 | *error = "could not create kcopyd client"; | |
2559 | r = PTR_ERR(cache->copier); | |
2560 | goto bad; | |
2561 | } | |
2562 | ||
b29d4986 | 2563 | cache->wq = alloc_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM, 0); |
c6b4fcba JT |
2564 | if (!cache->wq) { |
2565 | *error = "could not create workqueue for metadata object"; | |
2566 | goto bad; | |
2567 | } | |
b29d4986 | 2568 | INIT_WORK(&cache->deferred_bio_worker, process_deferred_bios); |
b29d4986 | 2569 | INIT_WORK(&cache->migration_worker, check_migrations); |
c6b4fcba | 2570 | INIT_DELAYED_WORK(&cache->waker, do_waker); |
c6b4fcba | 2571 | |
b29d4986 | 2572 | cache->prison = dm_bio_prison_create_v2(cache->wq); |
c6b4fcba JT |
2573 | if (!cache->prison) { |
2574 | *error = "could not create bio prison"; | |
2575 | goto bad; | |
2576 | } | |
2577 | ||
6f1c819c KO |
2578 | r = mempool_init_slab_pool(&cache->migration_pool, MIGRATION_POOL_SIZE, |
2579 | migration_cache); | |
2580 | if (r) { | |
c6b4fcba JT |
2581 | *error = "Error creating cache's migration mempool"; |
2582 | goto bad; | |
2583 | } | |
2584 | ||
c6b4fcba JT |
2585 | cache->need_tick_bio = true; |
2586 | cache->sized = false; | |
65790ff9 | 2587 | cache->invalidate = false; |
c6b4fcba JT |
2588 | cache->commit_requested = false; |
2589 | cache->loaded_mappings = false; | |
2590 | cache->loaded_discards = false; | |
2591 | ||
2592 | load_stats(cache); | |
2593 | ||
2594 | atomic_set(&cache->stats.demotion, 0); | |
2595 | atomic_set(&cache->stats.promotion, 0); | |
2596 | atomic_set(&cache->stats.copies_avoided, 0); | |
2597 | atomic_set(&cache->stats.cache_cell_clash, 0); | |
2598 | atomic_set(&cache->stats.commit_count, 0); | |
2599 | atomic_set(&cache->stats.discard_count, 0); | |
2600 | ||
65790ff9 JT |
2601 | spin_lock_init(&cache->invalidation_lock); |
2602 | INIT_LIST_HEAD(&cache->invalidation_requests); | |
2603 | ||
b29d4986 JT |
2604 | batcher_init(&cache->committer, commit_op, cache, |
2605 | issue_op, cache, cache->wq); | |
701e03e4 | 2606 | iot_init(&cache->tracker); |
066dbaa3 | 2607 | |
b29d4986 JT |
2608 | init_rwsem(&cache->background_work_lock); |
2609 | prevent_background_work(cache); | |
2610 | ||
c6b4fcba JT |
2611 | *result = cache; |
2612 | return 0; | |
c6b4fcba JT |
2613 | bad: |
2614 | destroy(cache); | |
2615 | return r; | |
2616 | } | |
2617 | ||
2618 | static int copy_ctr_args(struct cache *cache, int argc, const char **argv) | |
2619 | { | |
2620 | unsigned i; | |
2621 | const char **copy; | |
2622 | ||
2623 | copy = kcalloc(argc, sizeof(*copy), GFP_KERNEL); | |
2624 | if (!copy) | |
2625 | return -ENOMEM; | |
2626 | for (i = 0; i < argc; i++) { | |
2627 | copy[i] = kstrdup(argv[i], GFP_KERNEL); | |
2628 | if (!copy[i]) { | |
2629 | while (i--) | |
2630 | kfree(copy[i]); | |
2631 | kfree(copy); | |
2632 | return -ENOMEM; | |
2633 | } | |
2634 | } | |
2635 | ||
2636 | cache->nr_ctr_args = argc; | |
2637 | cache->ctr_args = copy; | |
2638 | ||
2639 | return 0; | |
2640 | } | |
2641 | ||
2642 | static int cache_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
2643 | { | |
2644 | int r = -EINVAL; | |
2645 | struct cache_args *ca; | |
2646 | struct cache *cache = NULL; | |
2647 | ||
2648 | ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
2649 | if (!ca) { | |
2650 | ti->error = "Error allocating memory for cache"; | |
2651 | return -ENOMEM; | |
2652 | } | |
2653 | ca->ti = ti; | |
2654 | ||
2655 | r = parse_cache_args(ca, argc, argv, &ti->error); | |
2656 | if (r) | |
2657 | goto out; | |
2658 | ||
2659 | r = cache_create(ca, &cache); | |
617a0b89 HM |
2660 | if (r) |
2661 | goto out; | |
c6b4fcba JT |
2662 | |
2663 | r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3); | |
2664 | if (r) { | |
2665 | destroy(cache); | |
2666 | goto out; | |
2667 | } | |
2668 | ||
2669 | ti->private = cache; | |
c6b4fcba JT |
2670 | out: |
2671 | destroy_cache_args(ca); | |
2672 | return r; | |
2673 | } | |
2674 | ||
651f5fa2 JT |
2675 | /*----------------------------------------------------------------*/ |
2676 | ||
2677 | static int cache_map(struct dm_target *ti, struct bio *bio) | |
c6b4fcba | 2678 | { |
651f5fa2 JT |
2679 | struct cache *cache = ti->private; |
2680 | ||
c6b4fcba | 2681 | int r; |
b29d4986 | 2682 | bool commit_needed; |
c6b4fcba | 2683 | dm_oblock_t block = get_bio_block(cache, bio); |
c6b4fcba | 2684 | |
693b960e | 2685 | init_per_bio_data(bio); |
e893fba9 | 2686 | if (unlikely(from_oblock(block) >= from_oblock(cache->origin_blocks))) { |
c6b4fcba JT |
2687 | /* |
2688 | * This can only occur if the io goes to a partial block at | |
2689 | * the end of the origin device. We don't cache these. | |
2690 | * Just remap to the origin and carry on. | |
2691 | */ | |
e893fba9 | 2692 | remap_to_origin(cache, bio); |
651f5fa2 | 2693 | accounted_begin(cache, bio); |
c6b4fcba JT |
2694 | return DM_MAPIO_REMAPPED; |
2695 | } | |
2696 | ||
651f5fa2 | 2697 | if (discard_or_flush(bio)) { |
c6b4fcba JT |
2698 | defer_bio(cache, bio); |
2699 | return DM_MAPIO_SUBMITTED; | |
2700 | } | |
2701 | ||
b29d4986 JT |
2702 | r = map_bio(cache, bio, block, &commit_needed); |
2703 | if (commit_needed) | |
2704 | schedule_commit(&cache->committer); | |
c6b4fcba | 2705 | |
2ee57d58 | 2706 | return r; |
c6b4fcba JT |
2707 | } |
2708 | ||
693b960e | 2709 | static int cache_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *error) |
c6b4fcba JT |
2710 | { |
2711 | struct cache *cache = ti->private; | |
2712 | unsigned long flags; | |
693b960e | 2713 | struct per_bio_data *pb = get_per_bio_data(bio); |
c6b4fcba JT |
2714 | |
2715 | if (pb->tick) { | |
fba10109 | 2716 | policy_tick(cache->policy, false); |
c6b4fcba JT |
2717 | |
2718 | spin_lock_irqsave(&cache->lock, flags); | |
2719 | cache->need_tick_bio = true; | |
2720 | spin_unlock_irqrestore(&cache->lock, flags); | |
2721 | } | |
2722 | ||
b29d4986 | 2723 | bio_drop_shared_lock(cache, bio); |
066dbaa3 | 2724 | accounted_complete(cache, bio); |
c6b4fcba | 2725 | |
1be56909 | 2726 | return DM_ENDIO_DONE; |
c6b4fcba JT |
2727 | } |
2728 | ||
2729 | static int write_dirty_bitset(struct cache *cache) | |
2730 | { | |
629d0a8a | 2731 | int r; |
c6b4fcba | 2732 | |
028ae9f7 JT |
2733 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
2734 | return -EINVAL; | |
2735 | ||
629d0a8a JT |
2736 | r = dm_cache_set_dirty_bits(cache->cmd, from_cblock(cache->cache_size), cache->dirty_bitset); |
2737 | if (r) | |
2738 | metadata_operation_failed(cache, "dm_cache_set_dirty_bits", r); | |
c6b4fcba | 2739 | |
629d0a8a | 2740 | return r; |
c6b4fcba JT |
2741 | } |
2742 | ||
2743 | static int write_discard_bitset(struct cache *cache) | |
2744 | { | |
2745 | unsigned i, r; | |
2746 | ||
028ae9f7 JT |
2747 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
2748 | return -EINVAL; | |
2749 | ||
1bad9bc4 JT |
2750 | r = dm_cache_discard_bitset_resize(cache->cmd, cache->discard_block_size, |
2751 | cache->discard_nr_blocks); | |
c6b4fcba | 2752 | if (r) { |
b61d9509 | 2753 | DMERR("%s: could not resize on-disk discard bitset", cache_device_name(cache)); |
028ae9f7 | 2754 | metadata_operation_failed(cache, "dm_cache_discard_bitset_resize", r); |
c6b4fcba JT |
2755 | return r; |
2756 | } | |
2757 | ||
1bad9bc4 JT |
2758 | for (i = 0; i < from_dblock(cache->discard_nr_blocks); i++) { |
2759 | r = dm_cache_set_discard(cache->cmd, to_dblock(i), | |
2760 | is_discarded(cache, to_dblock(i))); | |
028ae9f7 JT |
2761 | if (r) { |
2762 | metadata_operation_failed(cache, "dm_cache_set_discard", r); | |
c6b4fcba | 2763 | return r; |
028ae9f7 JT |
2764 | } |
2765 | } | |
2766 | ||
2767 | return 0; | |
2768 | } | |
2769 | ||
2770 | static int write_hints(struct cache *cache) | |
2771 | { | |
2772 | int r; | |
2773 | ||
2774 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
2775 | return -EINVAL; | |
2776 | ||
2777 | r = dm_cache_write_hints(cache->cmd, cache->policy); | |
2778 | if (r) { | |
2779 | metadata_operation_failed(cache, "dm_cache_write_hints", r); | |
2780 | return r; | |
c6b4fcba JT |
2781 | } |
2782 | ||
2783 | return 0; | |
2784 | } | |
2785 | ||
c6b4fcba JT |
2786 | /* |
2787 | * returns true on success | |
2788 | */ | |
2789 | static bool sync_metadata(struct cache *cache) | |
2790 | { | |
2791 | int r1, r2, r3, r4; | |
2792 | ||
2793 | r1 = write_dirty_bitset(cache); | |
2794 | if (r1) | |
b61d9509 | 2795 | DMERR("%s: could not write dirty bitset", cache_device_name(cache)); |
c6b4fcba JT |
2796 | |
2797 | r2 = write_discard_bitset(cache); | |
2798 | if (r2) | |
b61d9509 | 2799 | DMERR("%s: could not write discard bitset", cache_device_name(cache)); |
c6b4fcba JT |
2800 | |
2801 | save_stats(cache); | |
2802 | ||
028ae9f7 | 2803 | r3 = write_hints(cache); |
c6b4fcba | 2804 | if (r3) |
b61d9509 | 2805 | DMERR("%s: could not write hints", cache_device_name(cache)); |
c6b4fcba JT |
2806 | |
2807 | /* | |
2808 | * If writing the above metadata failed, we still commit, but don't | |
2809 | * set the clean shutdown flag. This will effectively force every | |
2810 | * dirty bit to be set on reload. | |
2811 | */ | |
028ae9f7 | 2812 | r4 = commit(cache, !r1 && !r2 && !r3); |
c6b4fcba | 2813 | if (r4) |
b61d9509 | 2814 | DMERR("%s: could not write cache metadata", cache_device_name(cache)); |
c6b4fcba JT |
2815 | |
2816 | return !r1 && !r2 && !r3 && !r4; | |
2817 | } | |
2818 | ||
2819 | static void cache_postsuspend(struct dm_target *ti) | |
2820 | { | |
2821 | struct cache *cache = ti->private; | |
2822 | ||
b29d4986 JT |
2823 | prevent_background_work(cache); |
2824 | BUG_ON(atomic_read(&cache->nr_io_migrations)); | |
2825 | ||
7cdf6a0a MP |
2826 | cancel_delayed_work_sync(&cache->waker); |
2827 | drain_workqueue(cache->wq); | |
701e03e4 | 2828 | WARN_ON(cache->tracker.in_flight); |
b29d4986 JT |
2829 | |
2830 | /* | |
2831 | * If it's a flush suspend there won't be any deferred bios, so this | |
2832 | * call is harmless. | |
2833 | */ | |
651f5fa2 | 2834 | requeue_deferred_bios(cache); |
c6b4fcba | 2835 | |
028ae9f7 JT |
2836 | if (get_cache_mode(cache) == CM_WRITE) |
2837 | (void) sync_metadata(cache); | |
c6b4fcba JT |
2838 | } |
2839 | ||
2840 | static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock, | |
2841 | bool dirty, uint32_t hint, bool hint_valid) | |
2842 | { | |
c6b4fcba JT |
2843 | struct cache *cache = context; |
2844 | ||
449b668c JT |
2845 | if (dirty) { |
2846 | set_bit(from_cblock(cblock), cache->dirty_bitset); | |
2847 | atomic_inc(&cache->nr_dirty); | |
2848 | } else | |
2849 | clear_bit(from_cblock(cblock), cache->dirty_bitset); | |
2850 | ||
b7770923 | 2851 | return policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid); |
c6b4fcba JT |
2852 | } |
2853 | ||
3e2e1c30 JT |
2854 | /* |
2855 | * The discard block size in the on disk metadata is not | |
2856 | * neccessarily the same as we're currently using. So we have to | |
2857 | * be careful to only set the discarded attribute if we know it | |
2858 | * covers a complete block of the new size. | |
2859 | */ | |
2860 | struct discard_load_info { | |
2861 | struct cache *cache; | |
2862 | ||
2863 | /* | |
2864 | * These blocks are sized using the on disk dblock size, rather | |
2865 | * than the current one. | |
2866 | */ | |
2867 | dm_block_t block_size; | |
2868 | dm_block_t discard_begin, discard_end; | |
2869 | }; | |
2870 | ||
2871 | static void discard_load_info_init(struct cache *cache, | |
2872 | struct discard_load_info *li) | |
2873 | { | |
2874 | li->cache = cache; | |
2875 | li->discard_begin = li->discard_end = 0; | |
2876 | } | |
2877 | ||
2878 | static void set_discard_range(struct discard_load_info *li) | |
2879 | { | |
2880 | sector_t b, e; | |
2881 | ||
2882 | if (li->discard_begin == li->discard_end) | |
2883 | return; | |
2884 | ||
2885 | /* | |
2886 | * Convert to sectors. | |
2887 | */ | |
2888 | b = li->discard_begin * li->block_size; | |
2889 | e = li->discard_end * li->block_size; | |
2890 | ||
2891 | /* | |
2892 | * Then convert back to the current dblock size. | |
2893 | */ | |
2894 | b = dm_sector_div_up(b, li->cache->discard_block_size); | |
2895 | sector_div(e, li->cache->discard_block_size); | |
2896 | ||
2897 | /* | |
2898 | * The origin may have shrunk, so we need to check we're still in | |
2899 | * bounds. | |
2900 | */ | |
2901 | if (e > from_dblock(li->cache->discard_nr_blocks)) | |
2902 | e = from_dblock(li->cache->discard_nr_blocks); | |
2903 | ||
2904 | for (; b < e; b++) | |
2905 | set_discard(li->cache, to_dblock(b)); | |
2906 | } | |
2907 | ||
c6b4fcba | 2908 | static int load_discard(void *context, sector_t discard_block_size, |
1bad9bc4 | 2909 | dm_dblock_t dblock, bool discard) |
c6b4fcba | 2910 | { |
3e2e1c30 | 2911 | struct discard_load_info *li = context; |
c6b4fcba | 2912 | |
3e2e1c30 | 2913 | li->block_size = discard_block_size; |
1bad9bc4 | 2914 | |
3e2e1c30 JT |
2915 | if (discard) { |
2916 | if (from_dblock(dblock) == li->discard_end) | |
2917 | /* | |
2918 | * We're already in a discard range, just extend it. | |
2919 | */ | |
2920 | li->discard_end = li->discard_end + 1ULL; | |
2921 | ||
2922 | else { | |
2923 | /* | |
2924 | * Emit the old range and start a new one. | |
2925 | */ | |
2926 | set_discard_range(li); | |
2927 | li->discard_begin = from_dblock(dblock); | |
2928 | li->discard_end = li->discard_begin + 1ULL; | |
2929 | } | |
2930 | } else { | |
2931 | set_discard_range(li); | |
2932 | li->discard_begin = li->discard_end = 0; | |
2933 | } | |
c6b4fcba JT |
2934 | |
2935 | return 0; | |
2936 | } | |
2937 | ||
f494a9c6 JT |
2938 | static dm_cblock_t get_cache_dev_size(struct cache *cache) |
2939 | { | |
2940 | sector_t size = get_dev_size(cache->cache_dev); | |
2941 | (void) sector_div(size, cache->sectors_per_block); | |
2942 | return to_cblock(size); | |
2943 | } | |
2944 | ||
2945 | static bool can_resize(struct cache *cache, dm_cblock_t new_size) | |
2946 | { | |
5d07384a MS |
2947 | if (from_cblock(new_size) > from_cblock(cache->cache_size)) { |
2948 | if (cache->sized) { | |
2949 | DMERR("%s: unable to extend cache due to missing cache table reload", | |
2950 | cache_device_name(cache)); | |
2951 | return false; | |
2952 | } | |
2953 | } | |
f494a9c6 JT |
2954 | |
2955 | /* | |
2956 | * We can't drop a dirty block when shrinking the cache. | |
2957 | */ | |
2958 | while (from_cblock(new_size) < from_cblock(cache->cache_size)) { | |
2959 | new_size = to_cblock(from_cblock(new_size) + 1); | |
2960 | if (is_dirty(cache, new_size)) { | |
b61d9509 MS |
2961 | DMERR("%s: unable to shrink cache; cache block %llu is dirty", |
2962 | cache_device_name(cache), | |
f494a9c6 JT |
2963 | (unsigned long long) from_cblock(new_size)); |
2964 | return false; | |
2965 | } | |
2966 | } | |
2967 | ||
2968 | return true; | |
2969 | } | |
2970 | ||
2971 | static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size) | |
2972 | { | |
2973 | int r; | |
2974 | ||
08844800 | 2975 | r = dm_cache_resize(cache->cmd, new_size); |
f494a9c6 | 2976 | if (r) { |
b61d9509 | 2977 | DMERR("%s: could not resize cache metadata", cache_device_name(cache)); |
028ae9f7 | 2978 | metadata_operation_failed(cache, "dm_cache_resize", r); |
f494a9c6 JT |
2979 | return r; |
2980 | } | |
2981 | ||
d1d9220c | 2982 | set_cache_size(cache, new_size); |
f494a9c6 JT |
2983 | |
2984 | return 0; | |
2985 | } | |
2986 | ||
c6b4fcba JT |
2987 | static int cache_preresume(struct dm_target *ti) |
2988 | { | |
2989 | int r = 0; | |
2990 | struct cache *cache = ti->private; | |
f494a9c6 | 2991 | dm_cblock_t csize = get_cache_dev_size(cache); |
c6b4fcba JT |
2992 | |
2993 | /* | |
2994 | * Check to see if the cache has resized. | |
2995 | */ | |
f494a9c6 JT |
2996 | if (!cache->sized) { |
2997 | r = resize_cache_dev(cache, csize); | |
2998 | if (r) | |
c6b4fcba | 2999 | return r; |
c6b4fcba JT |
3000 | |
3001 | cache->sized = true; | |
f494a9c6 JT |
3002 | |
3003 | } else if (csize != cache->cache_size) { | |
3004 | if (!can_resize(cache, csize)) | |
3005 | return -EINVAL; | |
3006 | ||
3007 | r = resize_cache_dev(cache, csize); | |
3008 | if (r) | |
3009 | return r; | |
c6b4fcba JT |
3010 | } |
3011 | ||
3012 | if (!cache->loaded_mappings) { | |
ea2dd8c1 | 3013 | r = dm_cache_load_mappings(cache->cmd, cache->policy, |
c6b4fcba JT |
3014 | load_mapping, cache); |
3015 | if (r) { | |
b61d9509 | 3016 | DMERR("%s: could not load cache mappings", cache_device_name(cache)); |
028ae9f7 | 3017 | metadata_operation_failed(cache, "dm_cache_load_mappings", r); |
c6b4fcba JT |
3018 | return r; |
3019 | } | |
3020 | ||
3021 | cache->loaded_mappings = true; | |
3022 | } | |
3023 | ||
3024 | if (!cache->loaded_discards) { | |
3e2e1c30 JT |
3025 | struct discard_load_info li; |
3026 | ||
3027 | /* | |
3028 | * The discard bitset could have been resized, or the | |
3029 | * discard block size changed. To be safe we start by | |
3030 | * setting every dblock to not discarded. | |
3031 | */ | |
3032 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); | |
3033 | ||
3034 | discard_load_info_init(cache, &li); | |
3035 | r = dm_cache_load_discards(cache->cmd, load_discard, &li); | |
c6b4fcba | 3036 | if (r) { |
b61d9509 | 3037 | DMERR("%s: could not load origin discards", cache_device_name(cache)); |
028ae9f7 | 3038 | metadata_operation_failed(cache, "dm_cache_load_discards", r); |
c6b4fcba JT |
3039 | return r; |
3040 | } | |
3e2e1c30 | 3041 | set_discard_range(&li); |
c6b4fcba JT |
3042 | |
3043 | cache->loaded_discards = true; | |
3044 | } | |
3045 | ||
3046 | return r; | |
3047 | } | |
3048 | ||
3049 | static void cache_resume(struct dm_target *ti) | |
3050 | { | |
3051 | struct cache *cache = ti->private; | |
3052 | ||
3053 | cache->need_tick_bio = true; | |
b29d4986 | 3054 | allow_background_work(cache); |
c6b4fcba JT |
3055 | do_waker(&cache->waker.work); |
3056 | } | |
3057 | ||
de7180ff MS |
3058 | static void emit_flags(struct cache *cache, char *result, |
3059 | unsigned maxlen, ssize_t *sz_ptr) | |
3060 | { | |
3061 | ssize_t sz = *sz_ptr; | |
3062 | struct cache_features *cf = &cache->features; | |
3063 | unsigned count = (cf->metadata_version == 2) + !cf->discard_passdown + 1; | |
3064 | ||
3065 | DMEMIT("%u ", count); | |
3066 | ||
3067 | if (cf->metadata_version == 2) | |
3068 | DMEMIT("metadata2 "); | |
3069 | ||
3070 | if (writethrough_mode(cache)) | |
3071 | DMEMIT("writethrough "); | |
3072 | ||
3073 | else if (passthrough_mode(cache)) | |
3074 | DMEMIT("passthrough "); | |
3075 | ||
3076 | else if (writeback_mode(cache)) | |
3077 | DMEMIT("writeback "); | |
3078 | ||
3079 | else { | |
3080 | DMEMIT("unknown "); | |
3081 | DMERR("%s: internal error: unknown io mode: %d", | |
3082 | cache_device_name(cache), (int) cf->io_mode); | |
3083 | } | |
3084 | ||
3085 | if (!cf->discard_passdown) | |
3086 | DMEMIT("no_discard_passdown "); | |
3087 | ||
3088 | *sz_ptr = sz; | |
3089 | } | |
3090 | ||
c6b4fcba JT |
3091 | /* |
3092 | * Status format: | |
3093 | * | |
6a388618 MS |
3094 | * <metadata block size> <#used metadata blocks>/<#total metadata blocks> |
3095 | * <cache block size> <#used cache blocks>/<#total cache blocks> | |
c6b4fcba | 3096 | * <#read hits> <#read misses> <#write hits> <#write misses> |
6a388618 | 3097 | * <#demotions> <#promotions> <#dirty> |
c6b4fcba JT |
3098 | * <#features> <features>* |
3099 | * <#core args> <core args> | |
255eac20 | 3100 | * <policy name> <#policy args> <policy args>* <cache metadata mode> <needs_check> |
c6b4fcba JT |
3101 | */ |
3102 | static void cache_status(struct dm_target *ti, status_type_t type, | |
3103 | unsigned status_flags, char *result, unsigned maxlen) | |
3104 | { | |
3105 | int r = 0; | |
3106 | unsigned i; | |
3107 | ssize_t sz = 0; | |
3108 | dm_block_t nr_free_blocks_metadata = 0; | |
3109 | dm_block_t nr_blocks_metadata = 0; | |
3110 | char buf[BDEVNAME_SIZE]; | |
3111 | struct cache *cache = ti->private; | |
3112 | dm_cblock_t residency; | |
d14fcf3d | 3113 | bool needs_check; |
c6b4fcba JT |
3114 | |
3115 | switch (type) { | |
3116 | case STATUSTYPE_INFO: | |
028ae9f7 JT |
3117 | if (get_cache_mode(cache) == CM_FAIL) { |
3118 | DMEMIT("Fail"); | |
3119 | break; | |
c6b4fcba JT |
3120 | } |
3121 | ||
028ae9f7 JT |
3122 | /* Commit to ensure statistics aren't out-of-date */ |
3123 | if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) | |
3124 | (void) commit(cache, false); | |
3125 | ||
b61d9509 | 3126 | r = dm_cache_get_free_metadata_block_count(cache->cmd, &nr_free_blocks_metadata); |
c6b4fcba | 3127 | if (r) { |
b61d9509 MS |
3128 | DMERR("%s: dm_cache_get_free_metadata_block_count returned %d", |
3129 | cache_device_name(cache), r); | |
c6b4fcba JT |
3130 | goto err; |
3131 | } | |
3132 | ||
3133 | r = dm_cache_get_metadata_dev_size(cache->cmd, &nr_blocks_metadata); | |
3134 | if (r) { | |
b61d9509 MS |
3135 | DMERR("%s: dm_cache_get_metadata_dev_size returned %d", |
3136 | cache_device_name(cache), r); | |
c6b4fcba JT |
3137 | goto err; |
3138 | } | |
3139 | ||
3140 | residency = policy_residency(cache->policy); | |
3141 | ||
ca763d0a | 3142 | DMEMIT("%u %llu/%llu %llu %llu/%llu %u %u %u %u %u %u %lu ", |
895b47d7 | 3143 | (unsigned)DM_CACHE_METADATA_BLOCK_SIZE, |
c6b4fcba JT |
3144 | (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), |
3145 | (unsigned long long)nr_blocks_metadata, | |
ca763d0a | 3146 | (unsigned long long)cache->sectors_per_block, |
6a388618 MS |
3147 | (unsigned long long) from_cblock(residency), |
3148 | (unsigned long long) from_cblock(cache->cache_size), | |
c6b4fcba JT |
3149 | (unsigned) atomic_read(&cache->stats.read_hit), |
3150 | (unsigned) atomic_read(&cache->stats.read_miss), | |
3151 | (unsigned) atomic_read(&cache->stats.write_hit), | |
3152 | (unsigned) atomic_read(&cache->stats.write_miss), | |
3153 | (unsigned) atomic_read(&cache->stats.demotion), | |
3154 | (unsigned) atomic_read(&cache->stats.promotion), | |
44fa816b | 3155 | (unsigned long) atomic_read(&cache->nr_dirty)); |
c6b4fcba | 3156 | |
de7180ff | 3157 | emit_flags(cache, result, maxlen, &sz); |
c6b4fcba JT |
3158 | |
3159 | DMEMIT("2 migration_threshold %llu ", (unsigned long long) cache->migration_threshold); | |
2e68c4e6 MS |
3160 | |
3161 | DMEMIT("%s ", dm_cache_policy_get_name(cache->policy)); | |
c6b4fcba | 3162 | if (sz < maxlen) { |
028ae9f7 | 3163 | r = policy_emit_config_values(cache->policy, result, maxlen, &sz); |
c6b4fcba | 3164 | if (r) |
b61d9509 MS |
3165 | DMERR("%s: policy_emit_config_values returned %d", |
3166 | cache_device_name(cache), r); | |
c6b4fcba JT |
3167 | } |
3168 | ||
028ae9f7 JT |
3169 | if (get_cache_mode(cache) == CM_READ_ONLY) |
3170 | DMEMIT("ro "); | |
3171 | else | |
3172 | DMEMIT("rw "); | |
3173 | ||
d14fcf3d JT |
3174 | r = dm_cache_metadata_needs_check(cache->cmd, &needs_check); |
3175 | ||
3176 | if (r || needs_check) | |
255eac20 MS |
3177 | DMEMIT("needs_check "); |
3178 | else | |
3179 | DMEMIT("- "); | |
3180 | ||
c6b4fcba JT |
3181 | break; |
3182 | ||
3183 | case STATUSTYPE_TABLE: | |
3184 | format_dev_t(buf, cache->metadata_dev->bdev->bd_dev); | |
3185 | DMEMIT("%s ", buf); | |
3186 | format_dev_t(buf, cache->cache_dev->bdev->bd_dev); | |
3187 | DMEMIT("%s ", buf); | |
3188 | format_dev_t(buf, cache->origin_dev->bdev->bd_dev); | |
3189 | DMEMIT("%s", buf); | |
3190 | ||
3191 | for (i = 0; i < cache->nr_ctr_args - 1; i++) | |
3192 | DMEMIT(" %s", cache->ctr_args[i]); | |
3193 | if (cache->nr_ctr_args) | |
3194 | DMEMIT(" %s", cache->ctr_args[cache->nr_ctr_args - 1]); | |
3195 | } | |
3196 | ||
3197 | return; | |
3198 | ||
3199 | err: | |
3200 | DMEMIT("Error"); | |
3201 | } | |
3202 | ||
b29d4986 JT |
3203 | /* |
3204 | * Defines a range of cblocks, begin to (end - 1) are in the range. end is | |
3205 | * the one-past-the-end value. | |
3206 | */ | |
3207 | struct cblock_range { | |
3208 | dm_cblock_t begin; | |
3209 | dm_cblock_t end; | |
3210 | }; | |
3211 | ||
c6b4fcba | 3212 | /* |
65790ff9 JT |
3213 | * A cache block range can take two forms: |
3214 | * | |
3215 | * i) A single cblock, eg. '3456' | |
b29d4986 | 3216 | * ii) A begin and end cblock with a dash between, eg. 123-234 |
65790ff9 JT |
3217 | */ |
3218 | static int parse_cblock_range(struct cache *cache, const char *str, | |
3219 | struct cblock_range *result) | |
3220 | { | |
3221 | char dummy; | |
3222 | uint64_t b, e; | |
3223 | int r; | |
3224 | ||
3225 | /* | |
3226 | * Try and parse form (ii) first. | |
3227 | */ | |
3228 | r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy); | |
3229 | if (r < 0) | |
3230 | return r; | |
3231 | ||
3232 | if (r == 2) { | |
3233 | result->begin = to_cblock(b); | |
3234 | result->end = to_cblock(e); | |
3235 | return 0; | |
3236 | } | |
3237 | ||
3238 | /* | |
3239 | * That didn't work, try form (i). | |
3240 | */ | |
3241 | r = sscanf(str, "%llu%c", &b, &dummy); | |
3242 | if (r < 0) | |
3243 | return r; | |
3244 | ||
3245 | if (r == 1) { | |
3246 | result->begin = to_cblock(b); | |
3247 | result->end = to_cblock(from_cblock(result->begin) + 1u); | |
3248 | return 0; | |
3249 | } | |
3250 | ||
b61d9509 | 3251 | DMERR("%s: invalid cblock range '%s'", cache_device_name(cache), str); |
65790ff9 JT |
3252 | return -EINVAL; |
3253 | } | |
3254 | ||
3255 | static int validate_cblock_range(struct cache *cache, struct cblock_range *range) | |
3256 | { | |
3257 | uint64_t b = from_cblock(range->begin); | |
3258 | uint64_t e = from_cblock(range->end); | |
3259 | uint64_t n = from_cblock(cache->cache_size); | |
3260 | ||
3261 | if (b >= n) { | |
b61d9509 MS |
3262 | DMERR("%s: begin cblock out of range: %llu >= %llu", |
3263 | cache_device_name(cache), b, n); | |
65790ff9 JT |
3264 | return -EINVAL; |
3265 | } | |
3266 | ||
3267 | if (e > n) { | |
b61d9509 MS |
3268 | DMERR("%s: end cblock out of range: %llu > %llu", |
3269 | cache_device_name(cache), e, n); | |
65790ff9 JT |
3270 | return -EINVAL; |
3271 | } | |
3272 | ||
3273 | if (b >= e) { | |
b61d9509 MS |
3274 | DMERR("%s: invalid cblock range: %llu >= %llu", |
3275 | cache_device_name(cache), b, e); | |
65790ff9 JT |
3276 | return -EINVAL; |
3277 | } | |
3278 | ||
3279 | return 0; | |
3280 | } | |
3281 | ||
b29d4986 JT |
3282 | static inline dm_cblock_t cblock_succ(dm_cblock_t b) |
3283 | { | |
3284 | return to_cblock(from_cblock(b) + 1); | |
3285 | } | |
3286 | ||
65790ff9 JT |
3287 | static int request_invalidation(struct cache *cache, struct cblock_range *range) |
3288 | { | |
b29d4986 | 3289 | int r = 0; |
65790ff9 | 3290 | |
b29d4986 JT |
3291 | /* |
3292 | * We don't need to do any locking here because we know we're in | |
3293 | * passthrough mode. There's is potential for a race between an | |
3294 | * invalidation triggered by an io and an invalidation message. This | |
3295 | * is harmless, we must not worry if the policy call fails. | |
3296 | */ | |
3297 | while (range->begin != range->end) { | |
3298 | r = invalidate_cblock(cache, range->begin); | |
3299 | if (r) | |
3300 | return r; | |
65790ff9 | 3301 | |
b29d4986 JT |
3302 | range->begin = cblock_succ(range->begin); |
3303 | } | |
65790ff9 | 3304 | |
b29d4986 JT |
3305 | cache->commit_requested = true; |
3306 | return r; | |
65790ff9 JT |
3307 | } |
3308 | ||
3309 | static int process_invalidate_cblocks_message(struct cache *cache, unsigned count, | |
3310 | const char **cblock_ranges) | |
3311 | { | |
3312 | int r = 0; | |
3313 | unsigned i; | |
3314 | struct cblock_range range; | |
3315 | ||
8e3c3827 | 3316 | if (!passthrough_mode(cache)) { |
b61d9509 MS |
3317 | DMERR("%s: cache has to be in passthrough mode for invalidation", |
3318 | cache_device_name(cache)); | |
65790ff9 JT |
3319 | return -EPERM; |
3320 | } | |
3321 | ||
3322 | for (i = 0; i < count; i++) { | |
3323 | r = parse_cblock_range(cache, cblock_ranges[i], &range); | |
3324 | if (r) | |
3325 | break; | |
3326 | ||
3327 | r = validate_cblock_range(cache, &range); | |
3328 | if (r) | |
3329 | break; | |
3330 | ||
3331 | /* | |
3332 | * Pass begin and end origin blocks to the worker and wake it. | |
3333 | */ | |
3334 | r = request_invalidation(cache, &range); | |
3335 | if (r) | |
3336 | break; | |
3337 | } | |
3338 | ||
3339 | return r; | |
3340 | } | |
3341 | ||
3342 | /* | |
3343 | * Supports | |
3344 | * "<key> <value>" | |
3345 | * and | |
3346 | * "invalidate_cblocks [(<begin>)|(<begin>-<end>)]* | |
c6b4fcba JT |
3347 | * |
3348 | * The key migration_threshold is supported by the cache target core. | |
3349 | */ | |
1eb5fa84 MS |
3350 | static int cache_message(struct dm_target *ti, unsigned argc, char **argv, |
3351 | char *result, unsigned maxlen) | |
c6b4fcba | 3352 | { |
c6b4fcba JT |
3353 | struct cache *cache = ti->private; |
3354 | ||
65790ff9 JT |
3355 | if (!argc) |
3356 | return -EINVAL; | |
3357 | ||
028ae9f7 | 3358 | if (get_cache_mode(cache) >= CM_READ_ONLY) { |
b61d9509 MS |
3359 | DMERR("%s: unable to service cache target messages in READ_ONLY or FAIL mode", |
3360 | cache_device_name(cache)); | |
028ae9f7 JT |
3361 | return -EOPNOTSUPP; |
3362 | } | |
3363 | ||
7b6b2bc9 | 3364 | if (!strcasecmp(argv[0], "invalidate_cblocks")) |
65790ff9 JT |
3365 | return process_invalidate_cblocks_message(cache, argc - 1, (const char **) argv + 1); |
3366 | ||
c6b4fcba JT |
3367 | if (argc != 2) |
3368 | return -EINVAL; | |
3369 | ||
2f14f4b5 | 3370 | return set_config_value(cache, argv[0], argv[1]); |
c6b4fcba JT |
3371 | } |
3372 | ||
3373 | static int cache_iterate_devices(struct dm_target *ti, | |
3374 | iterate_devices_callout_fn fn, void *data) | |
3375 | { | |
3376 | int r = 0; | |
3377 | struct cache *cache = ti->private; | |
3378 | ||
3379 | r = fn(ti, cache->cache_dev, 0, get_dev_size(cache->cache_dev), data); | |
3380 | if (!r) | |
3381 | r = fn(ti, cache->origin_dev, 0, ti->len, data); | |
3382 | ||
3383 | return r; | |
3384 | } | |
3385 | ||
de7180ff MS |
3386 | static bool origin_dev_supports_discard(struct block_device *origin_bdev) |
3387 | { | |
3388 | struct request_queue *q = bdev_get_queue(origin_bdev); | |
3389 | ||
3390 | return q && blk_queue_discard(q); | |
3391 | } | |
3392 | ||
3393 | /* | |
3394 | * If discard_passdown was enabled verify that the origin device | |
3395 | * supports discards. Disable discard_passdown if not. | |
3396 | */ | |
3397 | static void disable_passdown_if_not_supported(struct cache *cache) | |
3398 | { | |
3399 | struct block_device *origin_bdev = cache->origin_dev->bdev; | |
3400 | struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits; | |
3401 | const char *reason = NULL; | |
3402 | char buf[BDEVNAME_SIZE]; | |
3403 | ||
3404 | if (!cache->features.discard_passdown) | |
3405 | return; | |
3406 | ||
3407 | if (!origin_dev_supports_discard(origin_bdev)) | |
3408 | reason = "discard unsupported"; | |
3409 | ||
3410 | else if (origin_limits->max_discard_sectors < cache->sectors_per_block) | |
3411 | reason = "max discard sectors smaller than a block"; | |
3412 | ||
3413 | if (reason) { | |
3414 | DMWARN("Origin device (%s) %s: Disabling discard passdown.", | |
3415 | bdevname(origin_bdev, buf), reason); | |
3416 | cache->features.discard_passdown = false; | |
3417 | } | |
3418 | } | |
3419 | ||
c6b4fcba JT |
3420 | static void set_discard_limits(struct cache *cache, struct queue_limits *limits) |
3421 | { | |
de7180ff MS |
3422 | struct block_device *origin_bdev = cache->origin_dev->bdev; |
3423 | struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits; | |
3424 | ||
3425 | if (!cache->features.discard_passdown) { | |
3426 | /* No passdown is done so setting own virtual limits */ | |
3427 | limits->max_discard_sectors = min_t(sector_t, cache->discard_block_size * 1024, | |
3428 | cache->origin_sectors); | |
3429 | limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT; | |
3430 | return; | |
3431 | } | |
3432 | ||
c6b4fcba | 3433 | /* |
de7180ff MS |
3434 | * cache_iterate_devices() is stacking both origin and fast device limits |
3435 | * but discards aren't passed to fast device, so inherit origin's limits. | |
c6b4fcba | 3436 | */ |
de7180ff MS |
3437 | limits->max_discard_sectors = origin_limits->max_discard_sectors; |
3438 | limits->max_hw_discard_sectors = origin_limits->max_hw_discard_sectors; | |
3439 | limits->discard_granularity = origin_limits->discard_granularity; | |
3440 | limits->discard_alignment = origin_limits->discard_alignment; | |
3441 | limits->discard_misaligned = origin_limits->discard_misaligned; | |
c6b4fcba JT |
3442 | } |
3443 | ||
3444 | static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
3445 | { | |
3446 | struct cache *cache = ti->private; | |
f6109372 | 3447 | uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; |
c6b4fcba | 3448 | |
f6109372 MS |
3449 | /* |
3450 | * If the system-determined stacked limits are compatible with the | |
3451 | * cache's blocksize (io_opt is a factor) do not override them. | |
3452 | */ | |
3453 | if (io_opt_sectors < cache->sectors_per_block || | |
3454 | do_div(io_opt_sectors, cache->sectors_per_block)) { | |
b0246530 | 3455 | blk_limits_io_min(limits, cache->sectors_per_block << SECTOR_SHIFT); |
f6109372 MS |
3456 | blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT); |
3457 | } | |
de7180ff MS |
3458 | |
3459 | disable_passdown_if_not_supported(cache); | |
c6b4fcba JT |
3460 | set_discard_limits(cache, limits); |
3461 | } | |
3462 | ||
3463 | /*----------------------------------------------------------------*/ | |
3464 | ||
3465 | static struct target_type cache_target = { | |
3466 | .name = "cache", | |
636be424 | 3467 | .version = {2, 2, 0}, |
c6b4fcba JT |
3468 | .module = THIS_MODULE, |
3469 | .ctr = cache_ctr, | |
3470 | .dtr = cache_dtr, | |
3471 | .map = cache_map, | |
3472 | .end_io = cache_end_io, | |
3473 | .postsuspend = cache_postsuspend, | |
3474 | .preresume = cache_preresume, | |
3475 | .resume = cache_resume, | |
3476 | .status = cache_status, | |
3477 | .message = cache_message, | |
3478 | .iterate_devices = cache_iterate_devices, | |
c6b4fcba JT |
3479 | .io_hints = cache_io_hints, |
3480 | }; | |
3481 | ||
3482 | static int __init dm_cache_init(void) | |
3483 | { | |
3484 | int r; | |
3485 | ||
c6b4fcba | 3486 | migration_cache = KMEM_CACHE(dm_cache_migration, 0); |
c7cd5550 | 3487 | if (!migration_cache) |
c6b4fcba | 3488 | return -ENOMEM; |
c6b4fcba | 3489 | |
7e6358d2 | 3490 | r = dm_register_target(&cache_target); |
3491 | if (r) { | |
3492 | DMERR("cache target registration failed: %d", r); | |
c7cd5550 | 3493 | kmem_cache_destroy(migration_cache); |
7e6358d2 | 3494 | return r; |
3495 | } | |
3496 | ||
c6b4fcba JT |
3497 | return 0; |
3498 | } | |
3499 | ||
3500 | static void __exit dm_cache_exit(void) | |
3501 | { | |
3502 | dm_unregister_target(&cache_target); | |
3503 | kmem_cache_destroy(migration_cache); | |
3504 | } | |
3505 | ||
3506 | module_init(dm_cache_init); | |
3507 | module_exit(dm_cache_exit); | |
3508 | ||
3509 | MODULE_DESCRIPTION(DM_NAME " cache target"); | |
3510 | MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); | |
3511 | MODULE_LICENSE("GPL"); |