Commit | Line | Data |
---|---|---|
c6b4fcba JT |
1 | /* |
2 | * Copyright (C) 2012 Red Hat. All rights reserved. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7 | #include "dm.h" | |
b29d4986 | 8 | #include "dm-bio-prison-v2.h" |
b844fe69 | 9 | #include "dm-bio-record.h" |
c6b4fcba | 10 | #include "dm-cache-metadata.h" |
dc4fa29f | 11 | #include "dm-io-tracker.h" |
c6b4fcba JT |
12 | |
13 | #include <linux/dm-io.h> | |
14 | #include <linux/dm-kcopyd.h> | |
0f30af98 | 15 | #include <linux/jiffies.h> |
c6b4fcba JT |
16 | #include <linux/init.h> |
17 | #include <linux/mempool.h> | |
18 | #include <linux/module.h> | |
b29d4986 | 19 | #include <linux/rwsem.h> |
c6b4fcba JT |
20 | #include <linux/slab.h> |
21 | #include <linux/vmalloc.h> | |
22 | ||
23 | #define DM_MSG_PREFIX "cache" | |
24 | ||
25 | DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(cache_copy_throttle, | |
26 | "A percentage of time allocated for copying to and/or from cache"); | |
27 | ||
28 | /*----------------------------------------------------------------*/ | |
29 | ||
b29d4986 JT |
30 | /* |
31 | * Glossary: | |
32 | * | |
33 | * oblock: index of an origin block | |
34 | * cblock: index of a cache block | |
35 | * promotion: movement of a block from origin to cache | |
36 | * demotion: movement of a block from cache to origin | |
37 | * migration: movement of a block between the origin and cache device, | |
38 | * either direction | |
39 | */ | |
40 | ||
41 | /*----------------------------------------------------------------*/ | |
77289d32 | 42 | |
c6b4fcba | 43 | /* |
b29d4986 JT |
44 | * Represents a chunk of future work. 'input' allows continuations to pass |
45 | * values between themselves, typically error values. | |
c6b4fcba | 46 | */ |
b29d4986 JT |
47 | struct continuation { |
48 | struct work_struct ws; | |
4e4cbee9 | 49 | blk_status_t input; |
b29d4986 JT |
50 | }; |
51 | ||
52 | static inline void init_continuation(struct continuation *k, | |
53 | void (*fn)(struct work_struct *)) | |
54 | { | |
55 | INIT_WORK(&k->ws, fn); | |
56 | k->input = 0; | |
57 | } | |
58 | ||
59 | static inline void queue_continuation(struct workqueue_struct *wq, | |
60 | struct continuation *k) | |
61 | { | |
62 | queue_work(wq, &k->ws); | |
63 | } | |
c6b4fcba JT |
64 | |
65 | /*----------------------------------------------------------------*/ | |
66 | ||
b29d4986 JT |
67 | /* |
68 | * The batcher collects together pieces of work that need a particular | |
69 | * operation to occur before they can proceed (typically a commit). | |
70 | */ | |
71 | struct batcher { | |
72 | /* | |
73 | * The operation that everyone is waiting for. | |
74 | */ | |
4e4cbee9 | 75 | blk_status_t (*commit_op)(void *context); |
b29d4986 JT |
76 | void *commit_context; |
77 | ||
78 | /* | |
79 | * This is how bios should be issued once the commit op is complete | |
80 | * (accounted_request). | |
81 | */ | |
82 | void (*issue_op)(struct bio *bio, void *context); | |
83 | void *issue_context; | |
84 | ||
85 | /* | |
86 | * Queued work gets put on here after commit. | |
87 | */ | |
88 | struct workqueue_struct *wq; | |
89 | ||
90 | spinlock_t lock; | |
91 | struct list_head work_items; | |
92 | struct bio_list bios; | |
93 | struct work_struct commit_work; | |
94 | ||
95 | bool commit_scheduled; | |
96 | }; | |
97 | ||
98 | static void __commit(struct work_struct *_ws) | |
99 | { | |
100 | struct batcher *b = container_of(_ws, struct batcher, commit_work); | |
4e4cbee9 | 101 | blk_status_t r; |
b29d4986 JT |
102 | struct list_head work_items; |
103 | struct work_struct *ws, *tmp; | |
104 | struct continuation *k; | |
105 | struct bio *bio; | |
106 | struct bio_list bios; | |
107 | ||
108 | INIT_LIST_HEAD(&work_items); | |
109 | bio_list_init(&bios); | |
110 | ||
111 | /* | |
112 | * We have to grab these before the commit_op to avoid a race | |
113 | * condition. | |
114 | */ | |
26b924b9 | 115 | spin_lock_irq(&b->lock); |
b29d4986 JT |
116 | list_splice_init(&b->work_items, &work_items); |
117 | bio_list_merge(&bios, &b->bios); | |
118 | bio_list_init(&b->bios); | |
119 | b->commit_scheduled = false; | |
26b924b9 | 120 | spin_unlock_irq(&b->lock); |
b29d4986 JT |
121 | |
122 | r = b->commit_op(b->commit_context); | |
123 | ||
124 | list_for_each_entry_safe(ws, tmp, &work_items, entry) { | |
125 | k = container_of(ws, struct continuation, ws); | |
126 | k->input = r; | |
127 | INIT_LIST_HEAD(&ws->entry); /* to avoid a WARN_ON */ | |
128 | queue_work(b->wq, ws); | |
129 | } | |
130 | ||
131 | while ((bio = bio_list_pop(&bios))) { | |
132 | if (r) { | |
4e4cbee9 | 133 | bio->bi_status = r; |
b29d4986 JT |
134 | bio_endio(bio); |
135 | } else | |
136 | b->issue_op(bio, b->issue_context); | |
137 | } | |
138 | } | |
139 | ||
140 | static void batcher_init(struct batcher *b, | |
4e4cbee9 | 141 | blk_status_t (*commit_op)(void *), |
b29d4986 JT |
142 | void *commit_context, |
143 | void (*issue_op)(struct bio *bio, void *), | |
144 | void *issue_context, | |
145 | struct workqueue_struct *wq) | |
146 | { | |
147 | b->commit_op = commit_op; | |
148 | b->commit_context = commit_context; | |
149 | b->issue_op = issue_op; | |
150 | b->issue_context = issue_context; | |
151 | b->wq = wq; | |
152 | ||
153 | spin_lock_init(&b->lock); | |
154 | INIT_LIST_HEAD(&b->work_items); | |
155 | bio_list_init(&b->bios); | |
156 | INIT_WORK(&b->commit_work, __commit); | |
157 | b->commit_scheduled = false; | |
158 | } | |
159 | ||
160 | static void async_commit(struct batcher *b) | |
161 | { | |
162 | queue_work(b->wq, &b->commit_work); | |
163 | } | |
164 | ||
165 | static void continue_after_commit(struct batcher *b, struct continuation *k) | |
166 | { | |
b29d4986 JT |
167 | bool commit_scheduled; |
168 | ||
26b924b9 | 169 | spin_lock_irq(&b->lock); |
b29d4986 JT |
170 | commit_scheduled = b->commit_scheduled; |
171 | list_add_tail(&k->ws.entry, &b->work_items); | |
26b924b9 | 172 | spin_unlock_irq(&b->lock); |
b29d4986 JT |
173 | |
174 | if (commit_scheduled) | |
175 | async_commit(b); | |
176 | } | |
177 | ||
178 | /* | |
179 | * Bios are errored if commit failed. | |
180 | */ | |
181 | static void issue_after_commit(struct batcher *b, struct bio *bio) | |
182 | { | |
b29d4986 JT |
183 | bool commit_scheduled; |
184 | ||
26b924b9 | 185 | spin_lock_irq(&b->lock); |
b29d4986 JT |
186 | commit_scheduled = b->commit_scheduled; |
187 | bio_list_add(&b->bios, bio); | |
26b924b9 | 188 | spin_unlock_irq(&b->lock); |
b29d4986 JT |
189 | |
190 | if (commit_scheduled) | |
191 | async_commit(b); | |
192 | } | |
193 | ||
194 | /* | |
195 | * Call this if some urgent work is waiting for the commit to complete. | |
196 | */ | |
197 | static void schedule_commit(struct batcher *b) | |
198 | { | |
199 | bool immediate; | |
b29d4986 | 200 | |
26b924b9 | 201 | spin_lock_irq(&b->lock); |
b29d4986 JT |
202 | immediate = !list_empty(&b->work_items) || !bio_list_empty(&b->bios); |
203 | b->commit_scheduled = true; | |
26b924b9 | 204 | spin_unlock_irq(&b->lock); |
b29d4986 JT |
205 | |
206 | if (immediate) | |
207 | async_commit(b); | |
208 | } | |
209 | ||
c9d28d5d JT |
210 | /* |
211 | * There are a couple of places where we let a bio run, but want to do some | |
212 | * work before calling its endio function. We do this by temporarily | |
213 | * changing the endio fn. | |
214 | */ | |
215 | struct dm_hook_info { | |
216 | bio_end_io_t *bi_end_io; | |
c9d28d5d JT |
217 | }; |
218 | ||
219 | static void dm_hook_bio(struct dm_hook_info *h, struct bio *bio, | |
220 | bio_end_io_t *bi_end_io, void *bi_private) | |
221 | { | |
222 | h->bi_end_io = bio->bi_end_io; | |
c9d28d5d JT |
223 | |
224 | bio->bi_end_io = bi_end_io; | |
225 | bio->bi_private = bi_private; | |
226 | } | |
227 | ||
228 | static void dm_unhook_bio(struct dm_hook_info *h, struct bio *bio) | |
229 | { | |
230 | bio->bi_end_io = h->bi_end_io; | |
c9d28d5d JT |
231 | } |
232 | ||
233 | /*----------------------------------------------------------------*/ | |
234 | ||
c6b4fcba JT |
235 | #define MIGRATION_POOL_SIZE 128 |
236 | #define COMMIT_PERIOD HZ | |
237 | #define MIGRATION_COUNT_WINDOW 10 | |
238 | ||
239 | /* | |
05473044 MS |
240 | * The block size of the device holding cache data must be |
241 | * between 32KB and 1GB. | |
c6b4fcba JT |
242 | */ |
243 | #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (32 * 1024 >> SECTOR_SHIFT) | |
05473044 | 244 | #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT) |
c6b4fcba | 245 | |
2ee57d58 | 246 | enum cache_metadata_mode { |
c6b4fcba JT |
247 | CM_WRITE, /* metadata may be changed */ |
248 | CM_READ_ONLY, /* metadata may not be changed */ | |
028ae9f7 | 249 | CM_FAIL |
c6b4fcba JT |
250 | }; |
251 | ||
2ee57d58 JT |
252 | enum cache_io_mode { |
253 | /* | |
254 | * Data is written to cached blocks only. These blocks are marked | |
255 | * dirty. If you lose the cache device you will lose data. | |
256 | * Potential performance increase for both reads and writes. | |
257 | */ | |
258 | CM_IO_WRITEBACK, | |
259 | ||
260 | /* | |
261 | * Data is written to both cache and origin. Blocks are never | |
262 | * dirty. Potential performance benfit for reads only. | |
263 | */ | |
264 | CM_IO_WRITETHROUGH, | |
265 | ||
266 | /* | |
267 | * A degraded mode useful for various cache coherency situations | |
268 | * (eg, rolling back snapshots). Reads and writes always go to the | |
269 | * origin. If a write goes to a cached oblock, then the cache | |
270 | * block is invalidated. | |
271 | */ | |
272 | CM_IO_PASSTHROUGH | |
273 | }; | |
274 | ||
c6b4fcba | 275 | struct cache_features { |
2ee57d58 JT |
276 | enum cache_metadata_mode mode; |
277 | enum cache_io_mode io_mode; | |
629d0a8a | 278 | unsigned metadata_version; |
de7180ff | 279 | bool discard_passdown:1; |
c6b4fcba JT |
280 | }; |
281 | ||
282 | struct cache_stats { | |
283 | atomic_t read_hit; | |
284 | atomic_t read_miss; | |
285 | atomic_t write_hit; | |
286 | atomic_t write_miss; | |
287 | atomic_t demotion; | |
288 | atomic_t promotion; | |
b29d4986 | 289 | atomic_t writeback; |
c6b4fcba JT |
290 | atomic_t copies_avoided; |
291 | atomic_t cache_cell_clash; | |
292 | atomic_t commit_count; | |
293 | atomic_t discard_count; | |
294 | }; | |
295 | ||
296 | struct cache { | |
297 | struct dm_target *ti; | |
72d711c8 MS |
298 | spinlock_t lock; |
299 | ||
300 | /* | |
301 | * Fields for converting from sectors to blocks. | |
302 | */ | |
303 | int sectors_per_block_shift; | |
304 | sector_t sectors_per_block; | |
c6b4fcba | 305 | |
c9ec5d7c MS |
306 | struct dm_cache_metadata *cmd; |
307 | ||
c6b4fcba JT |
308 | /* |
309 | * Metadata is written to this device. | |
310 | */ | |
311 | struct dm_dev *metadata_dev; | |
312 | ||
313 | /* | |
314 | * The slower of the two data devices. Typically a spindle. | |
315 | */ | |
316 | struct dm_dev *origin_dev; | |
317 | ||
318 | /* | |
319 | * The faster of the two data devices. Typically an SSD. | |
320 | */ | |
321 | struct dm_dev *cache_dev; | |
322 | ||
c6b4fcba JT |
323 | /* |
324 | * Size of the origin device in _complete_ blocks and native sectors. | |
325 | */ | |
326 | dm_oblock_t origin_blocks; | |
327 | sector_t origin_sectors; | |
328 | ||
329 | /* | |
330 | * Size of the cache device in blocks. | |
331 | */ | |
332 | dm_cblock_t cache_size; | |
333 | ||
334 | /* | |
72d711c8 | 335 | * Invalidation fields. |
c6b4fcba | 336 | */ |
72d711c8 MS |
337 | spinlock_t invalidation_lock; |
338 | struct list_head invalidation_requests; | |
c6b4fcba | 339 | |
c6b4fcba | 340 | sector_t migration_threshold; |
c6b4fcba | 341 | wait_queue_head_t migration_wait; |
a59db676 JT |
342 | atomic_t nr_allocated_migrations; |
343 | ||
344 | /* | |
345 | * The number of in flight migrations that are performing | |
346 | * background io. eg, promotion, writeback. | |
347 | */ | |
348 | atomic_t nr_io_migrations; | |
c6b4fcba | 349 | |
72d711c8 MS |
350 | struct bio_list deferred_bios; |
351 | ||
b29d4986 | 352 | struct rw_semaphore quiesce_lock; |
66cb1910 | 353 | |
c6b4fcba JT |
354 | /* |
355 | * origin_blocks entries, discarded if set. | |
356 | */ | |
1bad9bc4 | 357 | dm_dblock_t discard_nr_blocks; |
c6b4fcba | 358 | unsigned long *discard_bitset; |
08b18451 | 359 | uint32_t discard_block_size; /* a power of 2 times sectors per block */ |
c9ec5d7c MS |
360 | |
361 | /* | |
362 | * Rather than reconstructing the table line for the status we just | |
363 | * save it and regurgitate. | |
364 | */ | |
365 | unsigned nr_ctr_args; | |
366 | const char **ctr_args; | |
c6b4fcba JT |
367 | |
368 | struct dm_kcopyd_client *copier; | |
b29d4986 | 369 | struct work_struct deferred_bio_worker; |
b29d4986 | 370 | struct work_struct migration_worker; |
72d711c8 | 371 | struct workqueue_struct *wq; |
c6b4fcba | 372 | struct delayed_work waker; |
b29d4986 | 373 | struct dm_bio_prison_v2 *prison; |
c6b4fcba | 374 | |
72d711c8 MS |
375 | /* |
376 | * cache_size entries, dirty if set | |
377 | */ | |
378 | unsigned long *dirty_bitset; | |
379 | atomic_t nr_dirty; | |
c6b4fcba | 380 | |
c6b4fcba | 381 | unsigned policy_nr_args; |
72d711c8 MS |
382 | struct dm_cache_policy *policy; |
383 | ||
384 | /* | |
385 | * Cache features such as write-through. | |
386 | */ | |
387 | struct cache_features features; | |
388 | ||
389 | struct cache_stats stats; | |
c6b4fcba JT |
390 | |
391 | bool need_tick_bio:1; | |
392 | bool sized:1; | |
65790ff9 | 393 | bool invalidate:1; |
c6b4fcba JT |
394 | bool commit_requested:1; |
395 | bool loaded_mappings:1; | |
396 | bool loaded_discards:1; | |
397 | ||
72d711c8 | 398 | struct rw_semaphore background_work_lock; |
65790ff9 | 399 | |
72d711c8 MS |
400 | struct batcher committer; |
401 | struct work_struct commit_ws; | |
066dbaa3 | 402 | |
dc4fa29f | 403 | struct dm_io_tracker tracker; |
b29d4986 | 404 | |
72d711c8 | 405 | mempool_t migration_pool; |
b29d4986 | 406 | |
72d711c8 | 407 | struct bio_set bs; |
c6b4fcba JT |
408 | }; |
409 | ||
410 | struct per_bio_data { | |
411 | bool tick:1; | |
412 | unsigned req_nr:2; | |
b29d4986 | 413 | struct dm_bio_prison_cell_v2 *cell; |
c6eda5e8 | 414 | struct dm_hook_info hook_info; |
066dbaa3 | 415 | sector_t len; |
c6b4fcba JT |
416 | }; |
417 | ||
418 | struct dm_cache_migration { | |
b29d4986 | 419 | struct continuation k; |
c6b4fcba JT |
420 | struct cache *cache; |
421 | ||
b29d4986 JT |
422 | struct policy_work *op; |
423 | struct bio *overwrite_bio; | |
424 | struct dm_bio_prison_cell_v2 *cell; | |
c6b4fcba | 425 | |
b29d4986 JT |
426 | dm_cblock_t invalidate_cblock; |
427 | dm_oblock_t invalidate_oblock; | |
c6b4fcba JT |
428 | }; |
429 | ||
b29d4986 JT |
430 | /*----------------------------------------------------------------*/ |
431 | ||
8e3c3827 | 432 | static bool writethrough_mode(struct cache *cache) |
b29d4986 | 433 | { |
8e3c3827 | 434 | return cache->features.io_mode == CM_IO_WRITETHROUGH; |
b29d4986 JT |
435 | } |
436 | ||
8e3c3827 | 437 | static bool writeback_mode(struct cache *cache) |
b29d4986 | 438 | { |
8e3c3827 | 439 | return cache->features.io_mode == CM_IO_WRITEBACK; |
b29d4986 JT |
440 | } |
441 | ||
8e3c3827 | 442 | static inline bool passthrough_mode(struct cache *cache) |
b29d4986 | 443 | { |
8e3c3827 | 444 | return unlikely(cache->features.io_mode == CM_IO_PASSTHROUGH); |
b29d4986 JT |
445 | } |
446 | ||
447 | /*----------------------------------------------------------------*/ | |
448 | ||
449 | static void wake_deferred_bio_worker(struct cache *cache) | |
450 | { | |
451 | queue_work(cache->wq, &cache->deferred_bio_worker); | |
452 | } | |
c6b4fcba | 453 | |
b29d4986 | 454 | static void wake_migration_worker(struct cache *cache) |
c6b4fcba | 455 | { |
8e3c3827 | 456 | if (passthrough_mode(cache)) |
b29d4986 JT |
457 | return; |
458 | ||
459 | queue_work(cache->wq, &cache->migration_worker); | |
c6b4fcba JT |
460 | } |
461 | ||
462 | /*----------------------------------------------------------------*/ | |
463 | ||
b29d4986 | 464 | static struct dm_bio_prison_cell_v2 *alloc_prison_cell(struct cache *cache) |
c6b4fcba | 465 | { |
13bd677a | 466 | return dm_bio_prison_alloc_cell_v2(cache->prison, GFP_NOIO); |
c6b4fcba JT |
467 | } |
468 | ||
b29d4986 | 469 | static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell_v2 *cell) |
c6b4fcba | 470 | { |
b29d4986 | 471 | dm_bio_prison_free_cell_v2(cache->prison, cell); |
c6b4fcba JT |
472 | } |
473 | ||
a59db676 JT |
474 | static struct dm_cache_migration *alloc_migration(struct cache *cache) |
475 | { | |
476 | struct dm_cache_migration *mg; | |
477 | ||
13bd677a | 478 | mg = mempool_alloc(&cache->migration_pool, GFP_NOIO); |
ef7afb36 MS |
479 | |
480 | memset(mg, 0, sizeof(*mg)); | |
481 | ||
482 | mg->cache = cache; | |
483 | atomic_inc(&cache->nr_allocated_migrations); | |
a59db676 JT |
484 | |
485 | return mg; | |
486 | } | |
487 | ||
488 | static void free_migration(struct dm_cache_migration *mg) | |
489 | { | |
88bf5184 | 490 | struct cache *cache = mg->cache; |
a59db676 | 491 | |
88bf5184 JT |
492 | if (atomic_dec_and_test(&cache->nr_allocated_migrations)) |
493 | wake_up(&cache->migration_wait); | |
494 | ||
6f1c819c | 495 | mempool_free(mg, &cache->migration_pool); |
a59db676 JT |
496 | } |
497 | ||
b29d4986 | 498 | /*----------------------------------------------------------------*/ |
c6b4fcba | 499 | |
b29d4986 | 500 | static inline dm_oblock_t oblock_succ(dm_oblock_t b) |
c6b4fcba | 501 | { |
b29d4986 | 502 | return to_oblock(from_oblock(b) + 1ull); |
c6b4fcba JT |
503 | } |
504 | ||
b29d4986 | 505 | static void build_key(dm_oblock_t begin, dm_oblock_t end, struct dm_cell_key_v2 *key) |
c6b4fcba | 506 | { |
b29d4986 JT |
507 | key->virtual = 0; |
508 | key->dev = 0; | |
509 | key->block_begin = from_oblock(begin); | |
510 | key->block_end = from_oblock(end); | |
c6b4fcba JT |
511 | } |
512 | ||
513 | /* | |
b29d4986 JT |
514 | * We have two lock levels. Level 0, which is used to prevent WRITEs, and |
515 | * level 1 which prevents *both* READs and WRITEs. | |
c6b4fcba | 516 | */ |
b29d4986 JT |
517 | #define WRITE_LOCK_LEVEL 0 |
518 | #define READ_WRITE_LOCK_LEVEL 1 | |
519 | ||
520 | static unsigned lock_level(struct bio *bio) | |
c6b4fcba | 521 | { |
b29d4986 JT |
522 | return bio_data_dir(bio) == WRITE ? |
523 | WRITE_LOCK_LEVEL : | |
524 | READ_WRITE_LOCK_LEVEL; | |
525 | } | |
c6b4fcba | 526 | |
b29d4986 JT |
527 | /*---------------------------------------------------------------- |
528 | * Per bio data | |
529 | *--------------------------------------------------------------*/ | |
c6b4fcba | 530 | |
693b960e | 531 | static struct per_bio_data *get_per_bio_data(struct bio *bio) |
b29d4986 | 532 | { |
693b960e | 533 | struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data)); |
b29d4986 JT |
534 | BUG_ON(!pb); |
535 | return pb; | |
536 | } | |
c6b4fcba | 537 | |
693b960e | 538 | static struct per_bio_data *init_per_bio_data(struct bio *bio) |
b29d4986 | 539 | { |
693b960e | 540 | struct per_bio_data *pb = get_per_bio_data(bio); |
c6b4fcba | 541 | |
b29d4986 JT |
542 | pb->tick = false; |
543 | pb->req_nr = dm_bio_get_target_bio_nr(bio); | |
544 | pb->cell = NULL; | |
545 | pb->len = 0; | |
546 | ||
547 | return pb; | |
c6b4fcba JT |
548 | } |
549 | ||
550 | /*----------------------------------------------------------------*/ | |
551 | ||
b29d4986 | 552 | static void defer_bio(struct cache *cache, struct bio *bio) |
c6b4fcba | 553 | { |
26b924b9 | 554 | spin_lock_irq(&cache->lock); |
b29d4986 | 555 | bio_list_add(&cache->deferred_bios, bio); |
26b924b9 | 556 | spin_unlock_irq(&cache->lock); |
b29d4986 JT |
557 | |
558 | wake_deferred_bio_worker(cache); | |
559 | } | |
c6b4fcba | 560 | |
b29d4986 | 561 | static void defer_bios(struct cache *cache, struct bio_list *bios) |
c6b4fcba | 562 | { |
26b924b9 | 563 | spin_lock_irq(&cache->lock); |
b29d4986 JT |
564 | bio_list_merge(&cache->deferred_bios, bios); |
565 | bio_list_init(bios); | |
26b924b9 | 566 | spin_unlock_irq(&cache->lock); |
c6b4fcba | 567 | |
b29d4986 | 568 | wake_deferred_bio_worker(cache); |
c6b4fcba JT |
569 | } |
570 | ||
b29d4986 JT |
571 | /*----------------------------------------------------------------*/ |
572 | ||
573 | static bool bio_detain_shared(struct cache *cache, dm_oblock_t oblock, struct bio *bio) | |
7ae34e77 | 574 | { |
b29d4986 | 575 | bool r; |
b29d4986 JT |
576 | struct per_bio_data *pb; |
577 | struct dm_cell_key_v2 key; | |
7ae34e77 | 578 | dm_oblock_t end = to_oblock(from_oblock(oblock) + 1ULL); |
b29d4986 | 579 | struct dm_bio_prison_cell_v2 *cell_prealloc, *cell; |
7ae34e77 | 580 | |
b29d4986 | 581 | cell_prealloc = alloc_prison_cell(cache); /* FIXME: allow wait if calling from worker */ |
b29d4986 JT |
582 | |
583 | build_key(oblock, end, &key); | |
584 | r = dm_cell_get_v2(cache->prison, &key, lock_level(bio), bio, cell_prealloc, &cell); | |
585 | if (!r) { | |
586 | /* | |
587 | * Failed to get the lock. | |
588 | */ | |
589 | free_prison_cell(cache, cell_prealloc); | |
590 | return r; | |
591 | } | |
c6b4fcba | 592 | |
b29d4986 JT |
593 | if (cell != cell_prealloc) |
594 | free_prison_cell(cache, cell_prealloc); | |
c6b4fcba | 595 | |
693b960e | 596 | pb = get_per_bio_data(bio); |
b29d4986 | 597 | pb->cell = cell; |
c6b4fcba JT |
598 | |
599 | return r; | |
600 | } | |
601 | ||
aeed1420 | 602 | /*----------------------------------------------------------------*/ |
c6b4fcba JT |
603 | |
604 | static bool is_dirty(struct cache *cache, dm_cblock_t b) | |
605 | { | |
606 | return test_bit(from_cblock(b), cache->dirty_bitset); | |
607 | } | |
608 | ||
b29d4986 | 609 | static void set_dirty(struct cache *cache, dm_cblock_t cblock) |
c6b4fcba JT |
610 | { |
611 | if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
44fa816b | 612 | atomic_inc(&cache->nr_dirty); |
b29d4986 | 613 | policy_set_dirty(cache->policy, cblock); |
c6b4fcba JT |
614 | } |
615 | } | |
616 | ||
b29d4986 JT |
617 | /* |
618 | * These two are called when setting after migrations to force the policy | |
619 | * and dirty bitset to be in sync. | |
620 | */ | |
621 | static void force_set_dirty(struct cache *cache, dm_cblock_t cblock) | |
622 | { | |
623 | if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) | |
624 | atomic_inc(&cache->nr_dirty); | |
625 | policy_set_dirty(cache->policy, cblock); | |
626 | } | |
627 | ||
628 | static void force_clear_dirty(struct cache *cache, dm_cblock_t cblock) | |
c6b4fcba JT |
629 | { |
630 | if (test_and_clear_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
44fa816b | 631 | if (atomic_dec_return(&cache->nr_dirty) == 0) |
c6b4fcba JT |
632 | dm_table_event(cache->ti->table); |
633 | } | |
b29d4986 JT |
634 | |
635 | policy_clear_dirty(cache->policy, cblock); | |
c6b4fcba JT |
636 | } |
637 | ||
638 | /*----------------------------------------------------------------*/ | |
aeed1420 | 639 | |
c6b4fcba JT |
640 | static bool block_size_is_power_of_two(struct cache *cache) |
641 | { | |
642 | return cache->sectors_per_block_shift >= 0; | |
643 | } | |
644 | ||
414dd67d JT |
645 | static dm_block_t block_div(dm_block_t b, uint32_t n) |
646 | { | |
647 | do_div(b, n); | |
648 | ||
649 | return b; | |
650 | } | |
651 | ||
7ae34e77 | 652 | static dm_block_t oblocks_per_dblock(struct cache *cache) |
1bad9bc4 | 653 | { |
7ae34e77 | 654 | dm_block_t oblocks = cache->discard_block_size; |
1bad9bc4 | 655 | |
7ae34e77 JT |
656 | if (block_size_is_power_of_two(cache)) |
657 | oblocks >>= cache->sectors_per_block_shift; | |
1bad9bc4 | 658 | else |
7ae34e77 | 659 | oblocks = block_div(oblocks, cache->sectors_per_block); |
1bad9bc4 | 660 | |
7ae34e77 JT |
661 | return oblocks; |
662 | } | |
663 | ||
664 | static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock) | |
665 | { | |
666 | return to_dblock(block_div(from_oblock(oblock), | |
667 | oblocks_per_dblock(cache))); | |
668 | } | |
1bad9bc4 | 669 | |
1bad9bc4 | 670 | static void set_discard(struct cache *cache, dm_dblock_t b) |
c6b4fcba | 671 | { |
7ae34e77 | 672 | BUG_ON(from_dblock(b) >= from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
673 | atomic_inc(&cache->stats.discard_count); |
674 | ||
26b924b9 | 675 | spin_lock_irq(&cache->lock); |
1bad9bc4 | 676 | set_bit(from_dblock(b), cache->discard_bitset); |
26b924b9 | 677 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
678 | } |
679 | ||
1bad9bc4 | 680 | static void clear_discard(struct cache *cache, dm_dblock_t b) |
c6b4fcba | 681 | { |
26b924b9 | 682 | spin_lock_irq(&cache->lock); |
1bad9bc4 | 683 | clear_bit(from_dblock(b), cache->discard_bitset); |
26b924b9 | 684 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
685 | } |
686 | ||
1bad9bc4 | 687 | static bool is_discarded(struct cache *cache, dm_dblock_t b) |
c6b4fcba JT |
688 | { |
689 | int r; | |
26b924b9 | 690 | spin_lock_irq(&cache->lock); |
1bad9bc4 | 691 | r = test_bit(from_dblock(b), cache->discard_bitset); |
26b924b9 | 692 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
693 | |
694 | return r; | |
695 | } | |
696 | ||
697 | static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b) | |
698 | { | |
699 | int r; | |
26b924b9 | 700 | spin_lock_irq(&cache->lock); |
1bad9bc4 JT |
701 | r = test_bit(from_dblock(oblock_to_dblock(cache, b)), |
702 | cache->discard_bitset); | |
26b924b9 | 703 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
704 | |
705 | return r; | |
706 | } | |
707 | ||
b29d4986 JT |
708 | /*---------------------------------------------------------------- |
709 | * Remapping | |
710 | *--------------------------------------------------------------*/ | |
711 | static void remap_to_origin(struct cache *cache, struct bio *bio) | |
c6b4fcba | 712 | { |
74d46992 | 713 | bio_set_dev(bio, cache->origin_dev->bdev); |
c6b4fcba JT |
714 | } |
715 | ||
716 | static void remap_to_cache(struct cache *cache, struct bio *bio, | |
717 | dm_cblock_t cblock) | |
718 | { | |
4f024f37 | 719 | sector_t bi_sector = bio->bi_iter.bi_sector; |
e0d849fa | 720 | sector_t block = from_cblock(cblock); |
c6b4fcba | 721 | |
74d46992 | 722 | bio_set_dev(bio, cache->cache_dev->bdev); |
c6b4fcba | 723 | if (!block_size_is_power_of_two(cache)) |
4f024f37 | 724 | bio->bi_iter.bi_sector = |
e0d849fa | 725 | (block * cache->sectors_per_block) + |
4f024f37 | 726 | sector_div(bi_sector, cache->sectors_per_block); |
c6b4fcba | 727 | else |
4f024f37 | 728 | bio->bi_iter.bi_sector = |
e0d849fa | 729 | (block << cache->sectors_per_block_shift) | |
4f024f37 | 730 | (bi_sector & (cache->sectors_per_block - 1)); |
c6b4fcba JT |
731 | } |
732 | ||
733 | static void check_if_tick_bio_needed(struct cache *cache, struct bio *bio) | |
734 | { | |
693b960e | 735 | struct per_bio_data *pb; |
c6b4fcba | 736 | |
26b924b9 | 737 | spin_lock_irq(&cache->lock); |
f73f44eb | 738 | if (cache->need_tick_bio && !op_is_flush(bio->bi_opf) && |
e6047149 | 739 | bio_op(bio) != REQ_OP_DISCARD) { |
693b960e | 740 | pb = get_per_bio_data(bio); |
c6b4fcba JT |
741 | pb->tick = true; |
742 | cache->need_tick_bio = false; | |
743 | } | |
26b924b9 | 744 | spin_unlock_irq(&cache->lock); |
c6b4fcba JT |
745 | } |
746 | ||
2df3bae9 MS |
747 | static void remap_to_origin_clear_discard(struct cache *cache, struct bio *bio, |
748 | dm_oblock_t oblock) | |
749 | { | |
750 | // FIXME: check_if_tick_bio_needed() is called way too much through this interface | |
3c4b455e CH |
751 | check_if_tick_bio_needed(cache, bio); |
752 | remap_to_origin(cache, bio); | |
753 | if (bio_data_dir(bio) == WRITE) | |
754 | clear_discard(cache, oblock_to_dblock(cache, oblock)); | |
2df3bae9 MS |
755 | } |
756 | ||
c6b4fcba JT |
757 | static void remap_to_cache_dirty(struct cache *cache, struct bio *bio, |
758 | dm_oblock_t oblock, dm_cblock_t cblock) | |
759 | { | |
f8e5f01a | 760 | check_if_tick_bio_needed(cache, bio); |
c6b4fcba JT |
761 | remap_to_cache(cache, bio, cblock); |
762 | if (bio_data_dir(bio) == WRITE) { | |
b29d4986 | 763 | set_dirty(cache, cblock); |
1bad9bc4 | 764 | clear_discard(cache, oblock_to_dblock(cache, oblock)); |
c6b4fcba JT |
765 | } |
766 | } | |
767 | ||
768 | static dm_oblock_t get_bio_block(struct cache *cache, struct bio *bio) | |
769 | { | |
4f024f37 | 770 | sector_t block_nr = bio->bi_iter.bi_sector; |
c6b4fcba JT |
771 | |
772 | if (!block_size_is_power_of_two(cache)) | |
773 | (void) sector_div(block_nr, cache->sectors_per_block); | |
774 | else | |
775 | block_nr >>= cache->sectors_per_block_shift; | |
776 | ||
777 | return to_oblock(block_nr); | |
778 | } | |
779 | ||
066dbaa3 JT |
780 | static bool accountable_bio(struct cache *cache, struct bio *bio) |
781 | { | |
701e03e4 | 782 | return bio_op(bio) != REQ_OP_DISCARD; |
066dbaa3 JT |
783 | } |
784 | ||
785 | static void accounted_begin(struct cache *cache, struct bio *bio) | |
786 | { | |
693b960e | 787 | struct per_bio_data *pb; |
066dbaa3 JT |
788 | |
789 | if (accountable_bio(cache, bio)) { | |
693b960e | 790 | pb = get_per_bio_data(bio); |
066dbaa3 | 791 | pb->len = bio_sectors(bio); |
dc4fa29f | 792 | dm_iot_io_begin(&cache->tracker, pb->len); |
066dbaa3 JT |
793 | } |
794 | } | |
795 | ||
796 | static void accounted_complete(struct cache *cache, struct bio *bio) | |
797 | { | |
693b960e | 798 | struct per_bio_data *pb = get_per_bio_data(bio); |
066dbaa3 | 799 | |
dc4fa29f | 800 | dm_iot_io_end(&cache->tracker, pb->len); |
066dbaa3 JT |
801 | } |
802 | ||
803 | static void accounted_request(struct cache *cache, struct bio *bio) | |
804 | { | |
805 | accounted_begin(cache, bio); | |
69596f55 | 806 | dm_submit_bio_remap(bio, NULL); |
066dbaa3 JT |
807 | } |
808 | ||
b29d4986 | 809 | static void issue_op(struct bio *bio, void *context) |
8c081b52 | 810 | { |
b29d4986 JT |
811 | struct cache *cache = context; |
812 | accounted_request(cache, bio); | |
8c081b52 JT |
813 | } |
814 | ||
e2e74d61 JT |
815 | /* |
816 | * When running in writethrough mode we need to send writes to clean blocks | |
2df3bae9 | 817 | * to both the cache and origin devices. Clone the bio and send them in parallel. |
e2e74d61 | 818 | */ |
2df3bae9 MS |
819 | static void remap_to_origin_and_cache(struct cache *cache, struct bio *bio, |
820 | dm_oblock_t oblock, dm_cblock_t cblock) | |
e2e74d61 | 821 | { |
abfc426d CH |
822 | struct bio *origin_bio = bio_alloc_clone(cache->origin_dev->bdev, bio, |
823 | GFP_NOIO, &cache->bs); | |
2df3bae9 MS |
824 | |
825 | BUG_ON(!origin_bio); | |
e2e74d61 | 826 | |
2df3bae9 | 827 | bio_chain(origin_bio, bio); |
3c4b455e | 828 | |
3c4b455e CH |
829 | if (bio_data_dir(origin_bio) == WRITE) |
830 | clear_discard(cache, oblock_to_dblock(cache, oblock)); | |
2df3bae9 | 831 | submit_bio(origin_bio); |
e2e74d61 | 832 | |
2df3bae9 | 833 | remap_to_cache(cache, bio, cblock); |
e2e74d61 JT |
834 | } |
835 | ||
028ae9f7 JT |
836 | /*---------------------------------------------------------------- |
837 | * Failure modes | |
838 | *--------------------------------------------------------------*/ | |
839 | static enum cache_metadata_mode get_cache_mode(struct cache *cache) | |
840 | { | |
841 | return cache->features.mode; | |
842 | } | |
843 | ||
b61d9509 MS |
844 | static const char *cache_device_name(struct cache *cache) |
845 | { | |
d4a512ed | 846 | return dm_table_device_name(cache->ti->table); |
b61d9509 MS |
847 | } |
848 | ||
028ae9f7 JT |
849 | static void notify_mode_switch(struct cache *cache, enum cache_metadata_mode mode) |
850 | { | |
851 | const char *descs[] = { | |
852 | "write", | |
853 | "read-only", | |
854 | "fail" | |
855 | }; | |
856 | ||
857 | dm_table_event(cache->ti->table); | |
b61d9509 MS |
858 | DMINFO("%s: switching cache to %s mode", |
859 | cache_device_name(cache), descs[(int)mode]); | |
028ae9f7 JT |
860 | } |
861 | ||
862 | static void set_cache_mode(struct cache *cache, enum cache_metadata_mode new_mode) | |
863 | { | |
d14fcf3d | 864 | bool needs_check; |
028ae9f7 JT |
865 | enum cache_metadata_mode old_mode = get_cache_mode(cache); |
866 | ||
d14fcf3d | 867 | if (dm_cache_metadata_needs_check(cache->cmd, &needs_check)) { |
23cab26d MS |
868 | DMERR("%s: unable to read needs_check flag, setting failure mode.", |
869 | cache_device_name(cache)); | |
d14fcf3d JT |
870 | new_mode = CM_FAIL; |
871 | } | |
872 | ||
028ae9f7 | 873 | if (new_mode == CM_WRITE && needs_check) { |
b61d9509 MS |
874 | DMERR("%s: unable to switch cache to write mode until repaired.", |
875 | cache_device_name(cache)); | |
028ae9f7 JT |
876 | if (old_mode != new_mode) |
877 | new_mode = old_mode; | |
878 | else | |
879 | new_mode = CM_READ_ONLY; | |
880 | } | |
881 | ||
882 | /* Never move out of fail mode */ | |
883 | if (old_mode == CM_FAIL) | |
884 | new_mode = CM_FAIL; | |
885 | ||
886 | switch (new_mode) { | |
887 | case CM_FAIL: | |
888 | case CM_READ_ONLY: | |
889 | dm_cache_metadata_set_read_only(cache->cmd); | |
890 | break; | |
891 | ||
892 | case CM_WRITE: | |
893 | dm_cache_metadata_set_read_write(cache->cmd); | |
894 | break; | |
895 | } | |
896 | ||
897 | cache->features.mode = new_mode; | |
898 | ||
899 | if (new_mode != old_mode) | |
900 | notify_mode_switch(cache, new_mode); | |
901 | } | |
902 | ||
903 | static void abort_transaction(struct cache *cache) | |
904 | { | |
b61d9509 MS |
905 | const char *dev_name = cache_device_name(cache); |
906 | ||
028ae9f7 JT |
907 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
908 | return; | |
909 | ||
910 | if (dm_cache_metadata_set_needs_check(cache->cmd)) { | |
b61d9509 | 911 | DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name); |
028ae9f7 JT |
912 | set_cache_mode(cache, CM_FAIL); |
913 | } | |
914 | ||
b61d9509 | 915 | DMERR_LIMIT("%s: aborting current metadata transaction", dev_name); |
028ae9f7 | 916 | if (dm_cache_metadata_abort(cache->cmd)) { |
b61d9509 | 917 | DMERR("%s: failed to abort metadata transaction", dev_name); |
028ae9f7 JT |
918 | set_cache_mode(cache, CM_FAIL); |
919 | } | |
920 | } | |
921 | ||
922 | static void metadata_operation_failed(struct cache *cache, const char *op, int r) | |
923 | { | |
b61d9509 MS |
924 | DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d", |
925 | cache_device_name(cache), op, r); | |
028ae9f7 JT |
926 | abort_transaction(cache); |
927 | set_cache_mode(cache, CM_READ_ONLY); | |
928 | } | |
929 | ||
b29d4986 JT |
930 | /*----------------------------------------------------------------*/ |
931 | ||
932 | static void load_stats(struct cache *cache) | |
933 | { | |
934 | struct dm_cache_statistics stats; | |
935 | ||
936 | dm_cache_metadata_get_stats(cache->cmd, &stats); | |
937 | atomic_set(&cache->stats.read_hit, stats.read_hits); | |
938 | atomic_set(&cache->stats.read_miss, stats.read_misses); | |
939 | atomic_set(&cache->stats.write_hit, stats.write_hits); | |
940 | atomic_set(&cache->stats.write_miss, stats.write_misses); | |
941 | } | |
942 | ||
943 | static void save_stats(struct cache *cache) | |
944 | { | |
945 | struct dm_cache_statistics stats; | |
946 | ||
947 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
948 | return; | |
949 | ||
950 | stats.read_hits = atomic_read(&cache->stats.read_hit); | |
951 | stats.read_misses = atomic_read(&cache->stats.read_miss); | |
952 | stats.write_hits = atomic_read(&cache->stats.write_hit); | |
953 | stats.write_misses = atomic_read(&cache->stats.write_miss); | |
954 | ||
955 | dm_cache_metadata_set_stats(cache->cmd, &stats); | |
956 | } | |
957 | ||
958 | static void update_stats(struct cache_stats *stats, enum policy_operation op) | |
959 | { | |
960 | switch (op) { | |
961 | case POLICY_PROMOTE: | |
962 | atomic_inc(&stats->promotion); | |
963 | break; | |
964 | ||
965 | case POLICY_DEMOTE: | |
966 | atomic_inc(&stats->demotion); | |
967 | break; | |
968 | ||
969 | case POLICY_WRITEBACK: | |
970 | atomic_inc(&stats->writeback); | |
971 | break; | |
972 | } | |
973 | } | |
974 | ||
c6b4fcba JT |
975 | /*---------------------------------------------------------------- |
976 | * Migration processing | |
977 | * | |
978 | * Migration covers moving data from the origin device to the cache, or | |
979 | * vice versa. | |
980 | *--------------------------------------------------------------*/ | |
b29d4986 | 981 | |
a59db676 | 982 | static void inc_io_migrations(struct cache *cache) |
c6b4fcba | 983 | { |
a59db676 | 984 | atomic_inc(&cache->nr_io_migrations); |
c6b4fcba JT |
985 | } |
986 | ||
a59db676 | 987 | static void dec_io_migrations(struct cache *cache) |
c6b4fcba | 988 | { |
a59db676 | 989 | atomic_dec(&cache->nr_io_migrations); |
c6b4fcba JT |
990 | } |
991 | ||
651f5fa2 JT |
992 | static bool discard_or_flush(struct bio *bio) |
993 | { | |
f73f44eb | 994 | return bio_op(bio) == REQ_OP_DISCARD || op_is_flush(bio->bi_opf); |
651f5fa2 JT |
995 | } |
996 | ||
b29d4986 JT |
997 | static void calc_discard_block_range(struct cache *cache, struct bio *bio, |
998 | dm_dblock_t *b, dm_dblock_t *e) | |
c6b4fcba | 999 | { |
b29d4986 JT |
1000 | sector_t sb = bio->bi_iter.bi_sector; |
1001 | sector_t se = bio_end_sector(bio); | |
651f5fa2 | 1002 | |
b29d4986 | 1003 | *b = to_dblock(dm_sector_div_up(sb, cache->discard_block_size)); |
c6b4fcba | 1004 | |
b29d4986 JT |
1005 | if (se - sb < cache->discard_block_size) |
1006 | *e = *b; | |
1007 | else | |
1008 | *e = to_dblock(block_div(se, cache->discard_block_size)); | |
c6b4fcba JT |
1009 | } |
1010 | ||
b29d4986 | 1011 | /*----------------------------------------------------------------*/ |
651f5fa2 | 1012 | |
b29d4986 | 1013 | static void prevent_background_work(struct cache *cache) |
651f5fa2 | 1014 | { |
b29d4986 JT |
1015 | lockdep_off(); |
1016 | down_write(&cache->background_work_lock); | |
1017 | lockdep_on(); | |
651f5fa2 JT |
1018 | } |
1019 | ||
b29d4986 | 1020 | static void allow_background_work(struct cache *cache) |
c6b4fcba | 1021 | { |
b29d4986 JT |
1022 | lockdep_off(); |
1023 | up_write(&cache->background_work_lock); | |
1024 | lockdep_on(); | |
c6b4fcba JT |
1025 | } |
1026 | ||
b29d4986 | 1027 | static bool background_work_begin(struct cache *cache) |
c6b4fcba | 1028 | { |
b29d4986 | 1029 | bool r; |
c6b4fcba | 1030 | |
b29d4986 JT |
1031 | lockdep_off(); |
1032 | r = down_read_trylock(&cache->background_work_lock); | |
1033 | lockdep_on(); | |
c6b4fcba | 1034 | |
b29d4986 | 1035 | return r; |
c6b4fcba JT |
1036 | } |
1037 | ||
b29d4986 | 1038 | static void background_work_end(struct cache *cache) |
c6b4fcba | 1039 | { |
b29d4986 JT |
1040 | lockdep_off(); |
1041 | up_read(&cache->background_work_lock); | |
1042 | lockdep_on(); | |
1043 | } | |
c6b4fcba | 1044 | |
b29d4986 | 1045 | /*----------------------------------------------------------------*/ |
c6b4fcba | 1046 | |
d1260e2a JT |
1047 | static bool bio_writes_complete_block(struct cache *cache, struct bio *bio) |
1048 | { | |
1049 | return (bio_data_dir(bio) == WRITE) && | |
1050 | (bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT)); | |
1051 | } | |
1052 | ||
1053 | static bool optimisable_bio(struct cache *cache, struct bio *bio, dm_oblock_t block) | |
1054 | { | |
8e3c3827 | 1055 | return writeback_mode(cache) && |
d1260e2a JT |
1056 | (is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio)); |
1057 | } | |
1058 | ||
b29d4986 JT |
1059 | static void quiesce(struct dm_cache_migration *mg, |
1060 | void (*continuation)(struct work_struct *)) | |
1061 | { | |
1062 | init_continuation(&mg->k, continuation); | |
1063 | dm_cell_quiesce_v2(mg->cache->prison, mg->cell, &mg->k.ws); | |
c6b4fcba JT |
1064 | } |
1065 | ||
b29d4986 | 1066 | static struct dm_cache_migration *ws_to_mg(struct work_struct *ws) |
c6b4fcba | 1067 | { |
b29d4986 JT |
1068 | struct continuation *k = container_of(ws, struct continuation, ws); |
1069 | return container_of(k, struct dm_cache_migration, k); | |
c6b4fcba JT |
1070 | } |
1071 | ||
1072 | static void copy_complete(int read_err, unsigned long write_err, void *context) | |
1073 | { | |
b29d4986 | 1074 | struct dm_cache_migration *mg = container_of(context, struct dm_cache_migration, k); |
c6b4fcba JT |
1075 | |
1076 | if (read_err || write_err) | |
4e4cbee9 | 1077 | mg->k.input = BLK_STS_IOERR; |
c6b4fcba | 1078 | |
b29d4986 | 1079 | queue_continuation(mg->cache->wq, &mg->k); |
c6b4fcba JT |
1080 | } |
1081 | ||
7209049d | 1082 | static void copy(struct dm_cache_migration *mg, bool promote) |
c6b4fcba | 1083 | { |
c6b4fcba JT |
1084 | struct dm_io_region o_region, c_region; |
1085 | struct cache *cache = mg->cache; | |
1086 | ||
1087 | o_region.bdev = cache->origin_dev->bdev; | |
b29d4986 | 1088 | o_region.sector = from_oblock(mg->op->oblock) * cache->sectors_per_block; |
c6b4fcba JT |
1089 | o_region.count = cache->sectors_per_block; |
1090 | ||
1091 | c_region.bdev = cache->cache_dev->bdev; | |
b29d4986 | 1092 | c_region.sector = from_cblock(mg->op->cblock) * cache->sectors_per_block; |
c6b4fcba JT |
1093 | c_region.count = cache->sectors_per_block; |
1094 | ||
b29d4986 | 1095 | if (promote) |
7209049d | 1096 | dm_kcopyd_copy(cache->copier, &o_region, 1, &c_region, 0, copy_complete, &mg->k); |
b29d4986 | 1097 | else |
7209049d | 1098 | dm_kcopyd_copy(cache->copier, &c_region, 1, &o_region, 0, copy_complete, &mg->k); |
b29d4986 JT |
1099 | } |
1100 | ||
1101 | static void bio_drop_shared_lock(struct cache *cache, struct bio *bio) | |
1102 | { | |
693b960e | 1103 | struct per_bio_data *pb = get_per_bio_data(bio); |
b29d4986 JT |
1104 | |
1105 | if (pb->cell && dm_cell_put_v2(cache->prison, pb->cell)) | |
1106 | free_prison_cell(cache, pb->cell); | |
1107 | pb->cell = NULL; | |
c6b4fcba JT |
1108 | } |
1109 | ||
4246a0b6 | 1110 | static void overwrite_endio(struct bio *bio) |
c9d28d5d JT |
1111 | { |
1112 | struct dm_cache_migration *mg = bio->bi_private; | |
1113 | struct cache *cache = mg->cache; | |
693b960e | 1114 | struct per_bio_data *pb = get_per_bio_data(bio); |
c9d28d5d | 1115 | |
80ae49aa MS |
1116 | dm_unhook_bio(&pb->hook_info, bio); |
1117 | ||
4e4cbee9 CH |
1118 | if (bio->bi_status) |
1119 | mg->k.input = bio->bi_status; | |
80ae49aa | 1120 | |
693b960e | 1121 | queue_continuation(cache->wq, &mg->k); |
c9d28d5d JT |
1122 | } |
1123 | ||
b29d4986 JT |
1124 | static void overwrite(struct dm_cache_migration *mg, |
1125 | void (*continuation)(struct work_struct *)) | |
c9d28d5d | 1126 | { |
b29d4986 | 1127 | struct bio *bio = mg->overwrite_bio; |
693b960e | 1128 | struct per_bio_data *pb = get_per_bio_data(bio); |
c9d28d5d JT |
1129 | |
1130 | dm_hook_bio(&pb->hook_info, bio, overwrite_endio, mg); | |
8c081b52 JT |
1131 | |
1132 | /* | |
b29d4986 JT |
1133 | * The overwrite bio is part of the copy operation, as such it does |
1134 | * not set/clear discard or dirty flags. | |
8c081b52 | 1135 | */ |
b29d4986 JT |
1136 | if (mg->op->op == POLICY_PROMOTE) |
1137 | remap_to_cache(mg->cache, bio, mg->op->cblock); | |
1138 | else | |
1139 | remap_to_origin(mg->cache, bio); | |
1140 | ||
1141 | init_continuation(&mg->k, continuation); | |
066dbaa3 | 1142 | accounted_request(mg->cache, bio); |
c9d28d5d JT |
1143 | } |
1144 | ||
b29d4986 JT |
1145 | /* |
1146 | * Migration steps: | |
1147 | * | |
1148 | * 1) exclusive lock preventing WRITEs | |
1149 | * 2) quiesce | |
1150 | * 3) copy or issue overwrite bio | |
1151 | * 4) upgrade to exclusive lock preventing READs and WRITEs | |
1152 | * 5) quiesce | |
1153 | * 6) update metadata and commit | |
1154 | * 7) unlock | |
1155 | */ | |
1156 | static void mg_complete(struct dm_cache_migration *mg, bool success) | |
c9d28d5d | 1157 | { |
b29d4986 JT |
1158 | struct bio_list bios; |
1159 | struct cache *cache = mg->cache; | |
1160 | struct policy_work *op = mg->op; | |
1161 | dm_cblock_t cblock = op->cblock; | |
1162 | ||
1163 | if (success) | |
1164 | update_stats(&cache->stats, op->op); | |
1165 | ||
1166 | switch (op->op) { | |
1167 | case POLICY_PROMOTE: | |
1168 | clear_discard(cache, oblock_to_dblock(cache, op->oblock)); | |
1169 | policy_complete_background_work(cache->policy, op, success); | |
1170 | ||
1171 | if (mg->overwrite_bio) { | |
1172 | if (success) | |
1173 | force_set_dirty(cache, cblock); | |
4e4cbee9 CH |
1174 | else if (mg->k.input) |
1175 | mg->overwrite_bio->bi_status = mg->k.input; | |
b29d4986 | 1176 | else |
4e4cbee9 | 1177 | mg->overwrite_bio->bi_status = BLK_STS_IOERR; |
b29d4986 JT |
1178 | bio_endio(mg->overwrite_bio); |
1179 | } else { | |
1180 | if (success) | |
1181 | force_clear_dirty(cache, cblock); | |
1182 | dec_io_migrations(cache); | |
1183 | } | |
1184 | break; | |
1185 | ||
1186 | case POLICY_DEMOTE: | |
1187 | /* | |
1188 | * We clear dirty here to update the nr_dirty counter. | |
1189 | */ | |
1190 | if (success) | |
1191 | force_clear_dirty(cache, cblock); | |
1192 | policy_complete_background_work(cache->policy, op, success); | |
1193 | dec_io_migrations(cache); | |
1194 | break; | |
1195 | ||
1196 | case POLICY_WRITEBACK: | |
1197 | if (success) | |
1198 | force_clear_dirty(cache, cblock); | |
1199 | policy_complete_background_work(cache->policy, op, success); | |
1200 | dec_io_migrations(cache); | |
1201 | break; | |
1202 | } | |
1203 | ||
1204 | bio_list_init(&bios); | |
1205 | if (mg->cell) { | |
1206 | if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios)) | |
1207 | free_prison_cell(cache, mg->cell); | |
1208 | } | |
1209 | ||
1210 | free_migration(mg); | |
1211 | defer_bios(cache, &bios); | |
1212 | wake_migration_worker(cache); | |
1213 | ||
1214 | background_work_end(cache); | |
c9d28d5d JT |
1215 | } |
1216 | ||
b29d4986 | 1217 | static void mg_success(struct work_struct *ws) |
c6b4fcba | 1218 | { |
b29d4986 JT |
1219 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1220 | mg_complete(mg, mg->k.input == 0); | |
c6b4fcba JT |
1221 | } |
1222 | ||
b29d4986 | 1223 | static void mg_update_metadata(struct work_struct *ws) |
7ae34e77 | 1224 | { |
b29d4986 JT |
1225 | int r; |
1226 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
c6b4fcba | 1227 | struct cache *cache = mg->cache; |
b29d4986 | 1228 | struct policy_work *op = mg->op; |
c6b4fcba | 1229 | |
b29d4986 JT |
1230 | switch (op->op) { |
1231 | case POLICY_PROMOTE: | |
1232 | r = dm_cache_insert_mapping(cache->cmd, op->cblock, op->oblock); | |
1233 | if (r) { | |
1234 | DMERR_LIMIT("%s: migration failed; couldn't insert mapping", | |
1235 | cache_device_name(cache)); | |
1236 | metadata_operation_failed(cache, "dm_cache_insert_mapping", r); | |
7ae34e77 | 1237 | |
b29d4986 JT |
1238 | mg_complete(mg, false); |
1239 | return; | |
1240 | } | |
1241 | mg_complete(mg, true); | |
1242 | break; | |
c9d28d5d | 1243 | |
b29d4986 JT |
1244 | case POLICY_DEMOTE: |
1245 | r = dm_cache_remove_mapping(cache->cmd, op->cblock); | |
1246 | if (r) { | |
1247 | DMERR_LIMIT("%s: migration failed; couldn't update on disk metadata", | |
1248 | cache_device_name(cache)); | |
1249 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); | |
c6b4fcba | 1250 | |
b29d4986 | 1251 | mg_complete(mg, false); |
c9d28d5d JT |
1252 | return; |
1253 | } | |
c9d28d5d | 1254 | |
b29d4986 JT |
1255 | /* |
1256 | * It would be nice if we only had to commit when a REQ_FLUSH | |
1257 | * comes through. But there's one scenario that we have to | |
1258 | * look out for: | |
1259 | * | |
1260 | * - vblock x in a cache block | |
1261 | * - domotion occurs | |
1262 | * - cache block gets reallocated and over written | |
1263 | * - crash | |
1264 | * | |
1265 | * When we recover, because there was no commit the cache will | |
1266 | * rollback to having the data for vblock x in the cache block. | |
1267 | * But the cache block has since been overwritten, so it'll end | |
1268 | * up pointing to data that was never in 'x' during the history | |
1269 | * of the device. | |
1270 | * | |
1271 | * To avoid this issue we require a commit as part of the | |
1272 | * demotion operation. | |
1273 | */ | |
1274 | init_continuation(&mg->k, mg_success); | |
1275 | continue_after_commit(&cache->committer, &mg->k); | |
1276 | schedule_commit(&cache->committer); | |
1277 | break; | |
1278 | ||
1279 | case POLICY_WRITEBACK: | |
1280 | mg_complete(mg, true); | |
1281 | break; | |
7ae34e77 | 1282 | } |
c6b4fcba JT |
1283 | } |
1284 | ||
b29d4986 | 1285 | static void mg_update_metadata_after_copy(struct work_struct *ws) |
c6b4fcba | 1286 | { |
b29d4986 JT |
1287 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1288 | ||
1289 | /* | |
1290 | * Did the copy succeed? | |
1291 | */ | |
1292 | if (mg->k.input) | |
1293 | mg_complete(mg, false); | |
c6b4fcba | 1294 | else |
b29d4986 | 1295 | mg_update_metadata(ws); |
c6b4fcba JT |
1296 | } |
1297 | ||
b29d4986 | 1298 | static void mg_upgrade_lock(struct work_struct *ws) |
c6b4fcba | 1299 | { |
b29d4986 JT |
1300 | int r; |
1301 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
c6b4fcba | 1302 | |
b29d4986 JT |
1303 | /* |
1304 | * Did the copy succeed? | |
1305 | */ | |
1306 | if (mg->k.input) | |
1307 | mg_complete(mg, false); | |
c6b4fcba | 1308 | |
c9d28d5d | 1309 | else { |
b29d4986 JT |
1310 | /* |
1311 | * Now we want the lock to prevent both reads and writes. | |
1312 | */ | |
1313 | r = dm_cell_lock_promote_v2(mg->cache->prison, mg->cell, | |
1314 | READ_WRITE_LOCK_LEVEL); | |
1315 | if (r < 0) | |
1316 | mg_complete(mg, false); | |
c6b4fcba | 1317 | |
b29d4986 JT |
1318 | else if (r) |
1319 | quiesce(mg, mg_update_metadata); | |
c6b4fcba | 1320 | |
b29d4986 JT |
1321 | else |
1322 | mg_update_metadata(ws); | |
c9d28d5d | 1323 | } |
c6b4fcba JT |
1324 | } |
1325 | ||
d1260e2a JT |
1326 | static void mg_full_copy(struct work_struct *ws) |
1327 | { | |
1328 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
1329 | struct cache *cache = mg->cache; | |
1330 | struct policy_work *op = mg->op; | |
1331 | bool is_policy_promote = (op->op == POLICY_PROMOTE); | |
1332 | ||
1333 | if ((!is_policy_promote && !is_dirty(cache, op->cblock)) || | |
1334 | is_discarded_oblock(cache, op->oblock)) { | |
1335 | mg_upgrade_lock(ws); | |
1336 | return; | |
1337 | } | |
1338 | ||
1339 | init_continuation(&mg->k, mg_upgrade_lock); | |
7209049d | 1340 | copy(mg, is_policy_promote); |
d1260e2a JT |
1341 | } |
1342 | ||
b29d4986 | 1343 | static void mg_copy(struct work_struct *ws) |
c6b4fcba | 1344 | { |
b29d4986 | 1345 | struct dm_cache_migration *mg = ws_to_mg(ws); |
c6b4fcba | 1346 | |
b29d4986 | 1347 | if (mg->overwrite_bio) { |
d1260e2a JT |
1348 | /* |
1349 | * No exclusive lock was held when we last checked if the bio | |
1350 | * was optimisable. So we have to check again in case things | |
1351 | * have changed (eg, the block may no longer be discarded). | |
1352 | */ | |
1353 | if (!optimisable_bio(mg->cache, mg->overwrite_bio, mg->op->oblock)) { | |
1354 | /* | |
1355 | * Fallback to a real full copy after doing some tidying up. | |
1356 | */ | |
1357 | bool rb = bio_detain_shared(mg->cache, mg->op->oblock, mg->overwrite_bio); | |
1358 | BUG_ON(rb); /* An exclussive lock must _not_ be held for this block */ | |
1359 | mg->overwrite_bio = NULL; | |
1360 | inc_io_migrations(mg->cache); | |
1361 | mg_full_copy(ws); | |
1362 | return; | |
1363 | } | |
1364 | ||
b29d4986 JT |
1365 | /* |
1366 | * It's safe to do this here, even though it's new data | |
1367 | * because all IO has been locked out of the block. | |
1368 | * | |
1369 | * mg_lock_writes() already took READ_WRITE_LOCK_LEVEL | |
1370 | * so _not_ using mg_upgrade_lock() as continutation. | |
1371 | */ | |
1372 | overwrite(mg, mg_update_metadata_after_copy); | |
c6b4fcba | 1373 | |
d1260e2a JT |
1374 | } else |
1375 | mg_full_copy(ws); | |
c6b4fcba JT |
1376 | } |
1377 | ||
b29d4986 | 1378 | static int mg_lock_writes(struct dm_cache_migration *mg) |
c6b4fcba | 1379 | { |
b29d4986 JT |
1380 | int r; |
1381 | struct dm_cell_key_v2 key; | |
c6b4fcba | 1382 | struct cache *cache = mg->cache; |
b29d4986 | 1383 | struct dm_bio_prison_cell_v2 *prealloc; |
c6b4fcba | 1384 | |
b29d4986 | 1385 | prealloc = alloc_prison_cell(cache); |
c6b4fcba | 1386 | |
b29d4986 JT |
1387 | /* |
1388 | * Prevent writes to the block, but allow reads to continue. | |
1389 | * Unless we're using an overwrite bio, in which case we lock | |
1390 | * everything. | |
1391 | */ | |
1392 | build_key(mg->op->oblock, oblock_succ(mg->op->oblock), &key); | |
1393 | r = dm_cell_lock_v2(cache->prison, &key, | |
1394 | mg->overwrite_bio ? READ_WRITE_LOCK_LEVEL : WRITE_LOCK_LEVEL, | |
1395 | prealloc, &mg->cell); | |
1396 | if (r < 0) { | |
1397 | free_prison_cell(cache, prealloc); | |
1398 | mg_complete(mg, false); | |
1399 | return r; | |
1400 | } | |
c6b4fcba | 1401 | |
b29d4986 JT |
1402 | if (mg->cell != prealloc) |
1403 | free_prison_cell(cache, prealloc); | |
c6b4fcba | 1404 | |
b29d4986 JT |
1405 | if (r == 0) |
1406 | mg_copy(&mg->k.ws); | |
1407 | else | |
1408 | quiesce(mg, mg_copy); | |
c6b4fcba | 1409 | |
b29d4986 | 1410 | return 0; |
c6b4fcba JT |
1411 | } |
1412 | ||
b29d4986 | 1413 | static int mg_start(struct cache *cache, struct policy_work *op, struct bio *bio) |
c6b4fcba | 1414 | { |
b29d4986 | 1415 | struct dm_cache_migration *mg; |
c6b4fcba | 1416 | |
b29d4986 JT |
1417 | if (!background_work_begin(cache)) { |
1418 | policy_complete_background_work(cache->policy, op, false); | |
1419 | return -EPERM; | |
1420 | } | |
2ee57d58 | 1421 | |
b29d4986 | 1422 | mg = alloc_migration(cache); |
2ee57d58 | 1423 | |
b29d4986 JT |
1424 | mg->op = op; |
1425 | mg->overwrite_bio = bio; | |
1426 | ||
1427 | if (!bio) | |
1428 | inc_io_migrations(cache); | |
7ae34e77 | 1429 | |
b29d4986 | 1430 | return mg_lock_writes(mg); |
7ae34e77 JT |
1431 | } |
1432 | ||
c6b4fcba | 1433 | /*---------------------------------------------------------------- |
b29d4986 | 1434 | * invalidation processing |
c6b4fcba | 1435 | *--------------------------------------------------------------*/ |
c6b4fcba | 1436 | |
b29d4986 | 1437 | static void invalidate_complete(struct dm_cache_migration *mg, bool success) |
c6b4fcba | 1438 | { |
b29d4986 JT |
1439 | struct bio_list bios; |
1440 | struct cache *cache = mg->cache; | |
c6b4fcba | 1441 | |
b29d4986 JT |
1442 | bio_list_init(&bios); |
1443 | if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios)) | |
1444 | free_prison_cell(cache, mg->cell); | |
c6b4fcba | 1445 | |
b29d4986 JT |
1446 | if (!success && mg->overwrite_bio) |
1447 | bio_io_error(mg->overwrite_bio); | |
c6b4fcba | 1448 | |
b29d4986 JT |
1449 | free_migration(mg); |
1450 | defer_bios(cache, &bios); | |
c6b4fcba | 1451 | |
b29d4986 | 1452 | background_work_end(cache); |
c6b4fcba JT |
1453 | } |
1454 | ||
b29d4986 | 1455 | static void invalidate_completed(struct work_struct *ws) |
c6b4fcba | 1456 | { |
b29d4986 JT |
1457 | struct dm_cache_migration *mg = ws_to_mg(ws); |
1458 | invalidate_complete(mg, !mg->k.input); | |
c6b4fcba JT |
1459 | } |
1460 | ||
b29d4986 | 1461 | static int invalidate_cblock(struct cache *cache, dm_cblock_t cblock) |
651f5fa2 | 1462 | { |
b29d4986 JT |
1463 | int r = policy_invalidate_mapping(cache->policy, cblock); |
1464 | if (!r) { | |
1465 | r = dm_cache_remove_mapping(cache->cmd, cblock); | |
1466 | if (r) { | |
1467 | DMERR_LIMIT("%s: invalidation failed; couldn't update on disk metadata", | |
1468 | cache_device_name(cache)); | |
1469 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); | |
651f5fa2 JT |
1470 | } |
1471 | ||
b29d4986 JT |
1472 | } else if (r == -ENODATA) { |
1473 | /* | |
1474 | * Harmless, already unmapped. | |
1475 | */ | |
1476 | r = 0; | |
651f5fa2 | 1477 | |
b29d4986 JT |
1478 | } else |
1479 | DMERR("%s: policy_invalidate_mapping failed", cache_device_name(cache)); | |
2ee57d58 | 1480 | |
b29d4986 | 1481 | return r; |
651f5fa2 JT |
1482 | } |
1483 | ||
b29d4986 | 1484 | static void invalidate_remove(struct work_struct *ws) |
651f5fa2 | 1485 | { |
b29d4986 JT |
1486 | int r; |
1487 | struct dm_cache_migration *mg = ws_to_mg(ws); | |
1488 | struct cache *cache = mg->cache; | |
651f5fa2 | 1489 | |
b29d4986 JT |
1490 | r = invalidate_cblock(cache, mg->invalidate_cblock); |
1491 | if (r) { | |
1492 | invalidate_complete(mg, false); | |
1493 | return; | |
651f5fa2 | 1494 | } |
9153df74 | 1495 | |
b29d4986 JT |
1496 | init_continuation(&mg->k, invalidate_completed); |
1497 | continue_after_commit(&cache->committer, &mg->k); | |
1498 | remap_to_origin_clear_discard(cache, mg->overwrite_bio, mg->invalidate_oblock); | |
1499 | mg->overwrite_bio = NULL; | |
1500 | schedule_commit(&cache->committer); | |
651f5fa2 JT |
1501 | } |
1502 | ||
b29d4986 | 1503 | static int invalidate_lock(struct dm_cache_migration *mg) |
651f5fa2 | 1504 | { |
b29d4986 JT |
1505 | int r; |
1506 | struct dm_cell_key_v2 key; | |
1507 | struct cache *cache = mg->cache; | |
1508 | struct dm_bio_prison_cell_v2 *prealloc; | |
651f5fa2 | 1509 | |
b29d4986 | 1510 | prealloc = alloc_prison_cell(cache); |
651f5fa2 | 1511 | |
b29d4986 JT |
1512 | build_key(mg->invalidate_oblock, oblock_succ(mg->invalidate_oblock), &key); |
1513 | r = dm_cell_lock_v2(cache->prison, &key, | |
1514 | READ_WRITE_LOCK_LEVEL, prealloc, &mg->cell); | |
1515 | if (r < 0) { | |
1516 | free_prison_cell(cache, prealloc); | |
1517 | invalidate_complete(mg, false); | |
1518 | return r; | |
651f5fa2 | 1519 | } |
9153df74 | 1520 | |
b29d4986 JT |
1521 | if (mg->cell != prealloc) |
1522 | free_prison_cell(cache, prealloc); | |
651f5fa2 | 1523 | |
b29d4986 JT |
1524 | if (r) |
1525 | quiesce(mg, invalidate_remove); | |
651f5fa2 | 1526 | |
b29d4986 JT |
1527 | else { |
1528 | /* | |
1529 | * We can't call invalidate_remove() directly here because we | |
1530 | * might still be in request context. | |
1531 | */ | |
1532 | init_continuation(&mg->k, invalidate_remove); | |
1533 | queue_work(cache->wq, &mg->k.ws); | |
1534 | } | |
fb4100ae | 1535 | |
fb4100ae JT |
1536 | return 0; |
1537 | } | |
1538 | ||
b29d4986 JT |
1539 | static int invalidate_start(struct cache *cache, dm_cblock_t cblock, |
1540 | dm_oblock_t oblock, struct bio *bio) | |
fb4100ae | 1541 | { |
b29d4986 | 1542 | struct dm_cache_migration *mg; |
2ee57d58 | 1543 | |
b29d4986 JT |
1544 | if (!background_work_begin(cache)) |
1545 | return -EPERM; | |
c6b4fcba | 1546 | |
b29d4986 | 1547 | mg = alloc_migration(cache); |
c6b4fcba | 1548 | |
b29d4986 JT |
1549 | mg->overwrite_bio = bio; |
1550 | mg->invalidate_cblock = cblock; | |
1551 | mg->invalidate_oblock = oblock; | |
c6b4fcba | 1552 | |
b29d4986 | 1553 | return invalidate_lock(mg); |
c6b4fcba | 1554 | } |
c6b4fcba | 1555 | |
b29d4986 JT |
1556 | /*---------------------------------------------------------------- |
1557 | * bio processing | |
1558 | *--------------------------------------------------------------*/ | |
c6b4fcba | 1559 | |
b29d4986 JT |
1560 | enum busy { |
1561 | IDLE, | |
b29d4986 JT |
1562 | BUSY |
1563 | }; | |
c6b4fcba | 1564 | |
b29d4986 | 1565 | static enum busy spare_migration_bandwidth(struct cache *cache) |
651f5fa2 | 1566 | { |
dc4fa29f | 1567 | bool idle = dm_iot_idle_for(&cache->tracker, HZ); |
a59db676 | 1568 | sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) * |
c6b4fcba | 1569 | cache->sectors_per_block; |
651f5fa2 | 1570 | |
49b7f768 JT |
1571 | if (idle && current_volume <= cache->migration_threshold) |
1572 | return IDLE; | |
b29d4986 | 1573 | else |
49b7f768 | 1574 | return BUSY; |
651f5fa2 JT |
1575 | } |
1576 | ||
c6b4fcba | 1577 | static void inc_hit_counter(struct cache *cache, struct bio *bio) |
c6b4fcba | 1578 | { |
c6b4fcba JT |
1579 | atomic_inc(bio_data_dir(bio) == READ ? |
1580 | &cache->stats.read_hit : &cache->stats.write_hit); | |
c6b4fcba JT |
1581 | } |
1582 | ||
c6b4fcba | 1583 | static void inc_miss_counter(struct cache *cache, struct bio *bio) |
028ae9f7 | 1584 | { |
c6b4fcba JT |
1585 | atomic_inc(bio_data_dir(bio) == READ ? |
1586 | &cache->stats.read_miss : &cache->stats.write_miss); | |
1587 | } | |
028ae9f7 | 1588 | |
fb4100ae | 1589 | /*----------------------------------------------------------------*/ |
028ae9f7 | 1590 | |
b29d4986 JT |
1591 | static int map_bio(struct cache *cache, struct bio *bio, dm_oblock_t block, |
1592 | bool *commit_needed) | |
c6b4fcba | 1593 | { |
b29d4986 JT |
1594 | int r, data_dir; |
1595 | bool rb, background_queued; | |
1596 | dm_cblock_t cblock; | |
c6b4fcba | 1597 | |
b29d4986 | 1598 | *commit_needed = false; |
c6b4fcba | 1599 | |
b29d4986 JT |
1600 | rb = bio_detain_shared(cache, block, bio); |
1601 | if (!rb) { | |
c6b4fcba | 1602 | /* |
b29d4986 JT |
1603 | * An exclusive lock is held for this block, so we have to |
1604 | * wait. We set the commit_needed flag so the current | |
1605 | * transaction will be committed asap, allowing this lock | |
1606 | * to be dropped. | |
c6b4fcba | 1607 | */ |
b29d4986 JT |
1608 | *commit_needed = true; |
1609 | return DM_MAPIO_SUBMITTED; | |
651f5fa2 | 1610 | } |
9153df74 | 1611 | |
b29d4986 | 1612 | data_dir = bio_data_dir(bio); |
651f5fa2 | 1613 | |
b29d4986 JT |
1614 | if (optimisable_bio(cache, bio, block)) { |
1615 | struct policy_work *op = NULL; | |
fb4100ae | 1616 | |
b29d4986 JT |
1617 | r = policy_lookup_with_work(cache->policy, block, &cblock, data_dir, true, &op); |
1618 | if (unlikely(r && r != -ENOENT)) { | |
1619 | DMERR_LIMIT("%s: policy_lookup_with_work() failed with r = %d", | |
1620 | cache_device_name(cache), r); | |
1621 | bio_io_error(bio); | |
1622 | return DM_MAPIO_SUBMITTED; | |
c6b4fcba JT |
1623 | } |
1624 | ||
b29d4986 JT |
1625 | if (r == -ENOENT && op) { |
1626 | bio_drop_shared_lock(cache, bio); | |
1627 | BUG_ON(op->op != POLICY_PROMOTE); | |
1628 | mg_start(cache, op, bio); | |
1629 | return DM_MAPIO_SUBMITTED; | |
1630 | } | |
1631 | } else { | |
1632 | r = policy_lookup(cache->policy, block, &cblock, data_dir, false, &background_queued); | |
1633 | if (unlikely(r && r != -ENOENT)) { | |
1634 | DMERR_LIMIT("%s: policy_lookup() failed with r = %d", | |
1635 | cache_device_name(cache), r); | |
1636 | bio_io_error(bio); | |
1637 | return DM_MAPIO_SUBMITTED; | |
1638 | } | |
c6b4fcba | 1639 | |
b29d4986 JT |
1640 | if (background_queued) |
1641 | wake_migration_worker(cache); | |
c6b4fcba JT |
1642 | } |
1643 | ||
b29d4986 | 1644 | if (r == -ENOENT) { |
693b960e MS |
1645 | struct per_bio_data *pb = get_per_bio_data(bio); |
1646 | ||
b29d4986 JT |
1647 | /* |
1648 | * Miss. | |
1649 | */ | |
1650 | inc_miss_counter(cache, bio); | |
1651 | if (pb->req_nr == 0) { | |
1652 | accounted_begin(cache, bio); | |
1653 | remap_to_origin_clear_discard(cache, bio, block); | |
b29d4986 | 1654 | } else { |
2ee57d58 | 1655 | /* |
b29d4986 JT |
1656 | * This is a duplicate writethrough io that is no |
1657 | * longer needed because the block has been demoted. | |
2ee57d58 | 1658 | */ |
b29d4986 JT |
1659 | bio_endio(bio); |
1660 | return DM_MAPIO_SUBMITTED; | |
1661 | } | |
1662 | } else { | |
1663 | /* | |
1664 | * Hit. | |
1665 | */ | |
1666 | inc_hit_counter(cache, bio); | |
651f5fa2 | 1667 | |
b29d4986 JT |
1668 | /* |
1669 | * Passthrough always maps to the origin, invalidating any | |
1670 | * cache blocks that are written to. | |
1671 | */ | |
8e3c3827 | 1672 | if (passthrough_mode(cache)) { |
2ee57d58 | 1673 | if (bio_data_dir(bio) == WRITE) { |
b29d4986 | 1674 | bio_drop_shared_lock(cache, bio); |
2ee57d58 | 1675 | atomic_inc(&cache->stats.demotion); |
b29d4986 JT |
1676 | invalidate_start(cache, cblock, block, bio); |
1677 | } else | |
2ee57d58 | 1678 | remap_to_origin_clear_discard(cache, bio, block); |
2ee57d58 | 1679 | } else { |
8e3c3827 | 1680 | if (bio_data_dir(bio) == WRITE && writethrough_mode(cache) && |
b29d4986 | 1681 | !is_dirty(cache, cblock)) { |
2df3bae9 | 1682 | remap_to_origin_and_cache(cache, bio, block, cblock); |
b29d4986 JT |
1683 | accounted_begin(cache, bio); |
1684 | } else | |
1685 | remap_to_cache_dirty(cache, bio, block, cblock); | |
2ee57d58 | 1686 | } |
c6b4fcba | 1687 | } |
651f5fa2 | 1688 | |
651f5fa2 | 1689 | /* |
b29d4986 | 1690 | * dm core turns FUA requests into a separate payload and FLUSH req. |
651f5fa2 | 1691 | */ |
b29d4986 | 1692 | if (bio->bi_opf & REQ_FUA) { |
651f5fa2 | 1693 | /* |
b29d4986 JT |
1694 | * issue_after_commit will call accounted_begin a second time. So |
1695 | * we call accounted_complete() to avoid double accounting. | |
651f5fa2 | 1696 | */ |
b29d4986 JT |
1697 | accounted_complete(cache, bio); |
1698 | issue_after_commit(&cache->committer, bio); | |
1699 | *commit_needed = true; | |
1700 | return DM_MAPIO_SUBMITTED; | |
651f5fa2 JT |
1701 | } |
1702 | ||
b29d4986 | 1703 | return DM_MAPIO_REMAPPED; |
651f5fa2 JT |
1704 | } |
1705 | ||
b29d4986 | 1706 | static bool process_bio(struct cache *cache, struct bio *bio) |
c6b4fcba | 1707 | { |
b29d4986 | 1708 | bool commit_needed; |
c6b4fcba | 1709 | |
b29d4986 | 1710 | if (map_bio(cache, bio, get_bio_block(cache, bio), &commit_needed) == DM_MAPIO_REMAPPED) |
69596f55 | 1711 | dm_submit_bio_remap(bio, NULL); |
c6b4fcba | 1712 | |
b29d4986 | 1713 | return commit_needed; |
c6b4fcba JT |
1714 | } |
1715 | ||
028ae9f7 JT |
1716 | /* |
1717 | * A non-zero return indicates read_only or fail_io mode. | |
1718 | */ | |
1719 | static int commit(struct cache *cache, bool clean_shutdown) | |
e2e74d61 | 1720 | { |
028ae9f7 | 1721 | int r; |
e2e74d61 | 1722 | |
028ae9f7 JT |
1723 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
1724 | return -EINVAL; | |
e2e74d61 | 1725 | |
028ae9f7 JT |
1726 | atomic_inc(&cache->stats.commit_count); |
1727 | r = dm_cache_commit(cache->cmd, clean_shutdown); | |
1728 | if (r) | |
1729 | metadata_operation_failed(cache, "dm_cache_commit", r); | |
e2e74d61 | 1730 | |
028ae9f7 | 1731 | return r; |
e2e74d61 JT |
1732 | } |
1733 | ||
b29d4986 JT |
1734 | /* |
1735 | * Used by the batcher. | |
1736 | */ | |
4e4cbee9 | 1737 | static blk_status_t commit_op(void *context) |
c6b4fcba | 1738 | { |
b29d4986 | 1739 | struct cache *cache = context; |
c6b4fcba | 1740 | |
b29d4986 | 1741 | if (dm_cache_changed_this_transaction(cache->cmd)) |
4e4cbee9 | 1742 | return errno_to_blk_status(commit(cache, false)); |
c6b4fcba | 1743 | |
b29d4986 | 1744 | return 0; |
c6b4fcba JT |
1745 | } |
1746 | ||
b29d4986 | 1747 | /*----------------------------------------------------------------*/ |
65790ff9 | 1748 | |
b29d4986 | 1749 | static bool process_flush_bio(struct cache *cache, struct bio *bio) |
65790ff9 | 1750 | { |
693b960e | 1751 | struct per_bio_data *pb = get_per_bio_data(bio); |
65790ff9 | 1752 | |
b29d4986 JT |
1753 | if (!pb->req_nr) |
1754 | remap_to_origin(cache, bio); | |
1755 | else | |
1756 | remap_to_cache(cache, bio, 0); | |
65790ff9 | 1757 | |
b29d4986 JT |
1758 | issue_after_commit(&cache->committer, bio); |
1759 | return true; | |
65790ff9 JT |
1760 | } |
1761 | ||
b29d4986 | 1762 | static bool process_discard_bio(struct cache *cache, struct bio *bio) |
65790ff9 | 1763 | { |
b29d4986 | 1764 | dm_dblock_t b, e; |
65790ff9 | 1765 | |
b29d4986 JT |
1766 | // FIXME: do we need to lock the region? Or can we just assume the |
1767 | // user wont be so foolish as to issue discard concurrently with | |
1768 | // other IO? | |
1769 | calc_discard_block_range(cache, bio, &b, &e); | |
1770 | while (b != e) { | |
1771 | set_discard(cache, b); | |
1772 | b = to_dblock(from_dblock(b) + 1); | |
651f5fa2 | 1773 | } |
65790ff9 | 1774 | |
de7180ff MS |
1775 | if (cache->features.discard_passdown) { |
1776 | remap_to_origin(cache, bio); | |
69596f55 | 1777 | dm_submit_bio_remap(bio, NULL); |
de7180ff MS |
1778 | } else |
1779 | bio_endio(bio); | |
65790ff9 | 1780 | |
b29d4986 | 1781 | return false; |
c6b4fcba JT |
1782 | } |
1783 | ||
b29d4986 | 1784 | static void process_deferred_bios(struct work_struct *ws) |
66cb1910 | 1785 | { |
b29d4986 | 1786 | struct cache *cache = container_of(ws, struct cache, deferred_bio_worker); |
66cb1910 | 1787 | |
b29d4986 | 1788 | bool commit_needed = false; |
c6b4fcba JT |
1789 | struct bio_list bios; |
1790 | struct bio *bio; | |
66cb1910 | 1791 | |
c6b4fcba | 1792 | bio_list_init(&bios); |
c6b4fcba | 1793 | |
26b924b9 | 1794 | spin_lock_irq(&cache->lock); |
b29d4986 JT |
1795 | bio_list_merge(&bios, &cache->deferred_bios); |
1796 | bio_list_init(&cache->deferred_bios); | |
26b924b9 | 1797 | spin_unlock_irq(&cache->lock); |
c6b4fcba | 1798 | |
b29d4986 JT |
1799 | while ((bio = bio_list_pop(&bios))) { |
1800 | if (bio->bi_opf & REQ_PREFLUSH) | |
1801 | commit_needed = process_flush_bio(cache, bio) || commit_needed; | |
c6b4fcba | 1802 | |
b29d4986 JT |
1803 | else if (bio_op(bio) == REQ_OP_DISCARD) |
1804 | commit_needed = process_discard_bio(cache, bio) || commit_needed; | |
1805 | ||
1806 | else | |
1807 | commit_needed = process_bio(cache, bio) || commit_needed; | |
1808 | } | |
1809 | ||
1810 | if (commit_needed) | |
1811 | schedule_commit(&cache->committer); | |
c6b4fcba JT |
1812 | } |
1813 | ||
c6b4fcba JT |
1814 | /*---------------------------------------------------------------- |
1815 | * Main worker loop | |
1816 | *--------------------------------------------------------------*/ | |
651f5fa2 JT |
1817 | |
1818 | static void requeue_deferred_bios(struct cache *cache) | |
c6b4fcba JT |
1819 | { |
1820 | struct bio *bio; | |
1821 | struct bio_list bios; | |
1822 | ||
1823 | bio_list_init(&bios); | |
1824 | bio_list_merge(&bios, &cache->deferred_bios); | |
1825 | bio_list_init(&cache->deferred_bios); | |
1826 | ||
4246a0b6 | 1827 | while ((bio = bio_list_pop(&bios))) { |
4e4cbee9 | 1828 | bio->bi_status = BLK_STS_DM_REQUEUE; |
4246a0b6 CH |
1829 | bio_endio(bio); |
1830 | } | |
c6b4fcba JT |
1831 | } |
1832 | ||
c6b4fcba JT |
1833 | /* |
1834 | * We want to commit periodically so that not too much | |
1835 | * unwritten metadata builds up. | |
1836 | */ | |
1837 | static void do_waker(struct work_struct *ws) | |
1838 | { | |
1839 | struct cache *cache = container_of(to_delayed_work(ws), struct cache, waker); | |
b29d4986 | 1840 | |
fba10109 | 1841 | policy_tick(cache->policy, true); |
b29d4986 JT |
1842 | wake_migration_worker(cache); |
1843 | schedule_commit(&cache->committer); | |
c6b4fcba JT |
1844 | queue_delayed_work(cache->wq, &cache->waker, COMMIT_PERIOD); |
1845 | } | |
1846 | ||
b29d4986 | 1847 | static void check_migrations(struct work_struct *ws) |
c6b4fcba | 1848 | { |
b29d4986 JT |
1849 | int r; |
1850 | struct policy_work *op; | |
1851 | struct cache *cache = container_of(ws, struct cache, migration_worker); | |
1852 | enum busy b; | |
c6b4fcba | 1853 | |
b29d4986 JT |
1854 | for (;;) { |
1855 | b = spare_migration_bandwidth(cache); | |
c6b4fcba | 1856 | |
b29d4986 JT |
1857 | r = policy_get_background_work(cache->policy, b == IDLE, &op); |
1858 | if (r == -ENODATA) | |
1859 | break; | |
1860 | ||
1861 | if (r) { | |
1862 | DMERR_LIMIT("%s: policy_background_work failed", | |
1863 | cache_device_name(cache)); | |
1864 | break; | |
1865 | } | |
1866 | ||
1867 | r = mg_start(cache, op, NULL); | |
1868 | if (r) | |
1869 | break; | |
1870 | } | |
c6b4fcba JT |
1871 | } |
1872 | ||
1873 | /*---------------------------------------------------------------- | |
1874 | * Target methods | |
1875 | *--------------------------------------------------------------*/ | |
1876 | ||
1877 | /* | |
1878 | * This function gets called on the error paths of the constructor, so we | |
1879 | * have to cope with a partially initialised struct. | |
1880 | */ | |
1881 | static void destroy(struct cache *cache) | |
1882 | { | |
1883 | unsigned i; | |
1884 | ||
6f1c819c | 1885 | mempool_exit(&cache->migration_pool); |
c6b4fcba | 1886 | |
c6b4fcba | 1887 | if (cache->prison) |
b29d4986 | 1888 | dm_bio_prison_destroy_v2(cache->prison); |
c6b4fcba JT |
1889 | |
1890 | if (cache->wq) | |
1891 | destroy_workqueue(cache->wq); | |
1892 | ||
1893 | if (cache->dirty_bitset) | |
1894 | free_bitset(cache->dirty_bitset); | |
1895 | ||
1896 | if (cache->discard_bitset) | |
1897 | free_bitset(cache->discard_bitset); | |
1898 | ||
1899 | if (cache->copier) | |
1900 | dm_kcopyd_client_destroy(cache->copier); | |
1901 | ||
1902 | if (cache->cmd) | |
1903 | dm_cache_metadata_close(cache->cmd); | |
1904 | ||
1905 | if (cache->metadata_dev) | |
1906 | dm_put_device(cache->ti, cache->metadata_dev); | |
1907 | ||
1908 | if (cache->origin_dev) | |
1909 | dm_put_device(cache->ti, cache->origin_dev); | |
1910 | ||
1911 | if (cache->cache_dev) | |
1912 | dm_put_device(cache->ti, cache->cache_dev); | |
1913 | ||
1914 | if (cache->policy) | |
1915 | dm_cache_policy_destroy(cache->policy); | |
1916 | ||
1917 | for (i = 0; i < cache->nr_ctr_args ; i++) | |
1918 | kfree(cache->ctr_args[i]); | |
1919 | kfree(cache->ctr_args); | |
1920 | ||
6f1c819c | 1921 | bioset_exit(&cache->bs); |
2df3bae9 | 1922 | |
c6b4fcba JT |
1923 | kfree(cache); |
1924 | } | |
1925 | ||
1926 | static void cache_dtr(struct dm_target *ti) | |
1927 | { | |
1928 | struct cache *cache = ti->private; | |
1929 | ||
1930 | destroy(cache); | |
1931 | } | |
1932 | ||
1933 | static sector_t get_dev_size(struct dm_dev *dev) | |
1934 | { | |
6dcbb52c | 1935 | return bdev_nr_sectors(dev->bdev); |
c6b4fcba JT |
1936 | } |
1937 | ||
1938 | /*----------------------------------------------------------------*/ | |
1939 | ||
1940 | /* | |
1941 | * Construct a cache device mapping. | |
1942 | * | |
1943 | * cache <metadata dev> <cache dev> <origin dev> <block size> | |
1944 | * <#feature args> [<feature arg>]* | |
1945 | * <policy> <#policy args> [<policy arg>]* | |
1946 | * | |
1947 | * metadata dev : fast device holding the persistent metadata | |
1948 | * cache dev : fast device holding cached data blocks | |
1949 | * origin dev : slow device holding original data blocks | |
1950 | * block size : cache unit size in sectors | |
1951 | * | |
1952 | * #feature args : number of feature arguments passed | |
1953 | * feature args : writethrough. (The default is writeback.) | |
1954 | * | |
1955 | * policy : the replacement policy to use | |
1956 | * #policy args : an even number of policy arguments corresponding | |
1957 | * to key/value pairs passed to the policy | |
1958 | * policy args : key/value pairs passed to the policy | |
1959 | * E.g. 'sequential_threshold 1024' | |
1960 | * See cache-policies.txt for details. | |
1961 | * | |
1962 | * Optional feature arguments are: | |
1963 | * writethrough : write through caching that prohibits cache block | |
1964 | * content from being different from origin block content. | |
1965 | * Without this argument, the default behaviour is to write | |
1966 | * back cache block contents later for performance reasons, | |
1967 | * so they may differ from the corresponding origin blocks. | |
1968 | */ | |
1969 | struct cache_args { | |
1970 | struct dm_target *ti; | |
1971 | ||
1972 | struct dm_dev *metadata_dev; | |
1973 | ||
1974 | struct dm_dev *cache_dev; | |
1975 | sector_t cache_sectors; | |
1976 | ||
1977 | struct dm_dev *origin_dev; | |
1978 | sector_t origin_sectors; | |
1979 | ||
1980 | uint32_t block_size; | |
1981 | ||
1982 | const char *policy_name; | |
1983 | int policy_argc; | |
1984 | const char **policy_argv; | |
1985 | ||
1986 | struct cache_features features; | |
1987 | }; | |
1988 | ||
1989 | static void destroy_cache_args(struct cache_args *ca) | |
1990 | { | |
1991 | if (ca->metadata_dev) | |
1992 | dm_put_device(ca->ti, ca->metadata_dev); | |
1993 | ||
1994 | if (ca->cache_dev) | |
1995 | dm_put_device(ca->ti, ca->cache_dev); | |
1996 | ||
1997 | if (ca->origin_dev) | |
1998 | dm_put_device(ca->ti, ca->origin_dev); | |
1999 | ||
2000 | kfree(ca); | |
2001 | } | |
2002 | ||
2003 | static bool at_least_one_arg(struct dm_arg_set *as, char **error) | |
2004 | { | |
2005 | if (!as->argc) { | |
2006 | *error = "Insufficient args"; | |
2007 | return false; | |
2008 | } | |
2009 | ||
2010 | return true; | |
2011 | } | |
2012 | ||
2013 | static int parse_metadata_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2014 | char **error) | |
2015 | { | |
2016 | int r; | |
2017 | sector_t metadata_dev_size; | |
c6b4fcba JT |
2018 | |
2019 | if (!at_least_one_arg(as, error)) | |
2020 | return -EINVAL; | |
2021 | ||
2022 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2023 | &ca->metadata_dev); | |
2024 | if (r) { | |
2025 | *error = "Error opening metadata device"; | |
2026 | return r; | |
2027 | } | |
2028 | ||
2029 | metadata_dev_size = get_dev_size(ca->metadata_dev); | |
2030 | if (metadata_dev_size > DM_CACHE_METADATA_MAX_SECTORS_WARNING) | |
385411ff CH |
2031 | DMWARN("Metadata device %pg is larger than %u sectors: excess space will not be used.", |
2032 | ca->metadata_dev->bdev, THIN_METADATA_MAX_SECTORS); | |
c6b4fcba JT |
2033 | |
2034 | return 0; | |
2035 | } | |
2036 | ||
2037 | static int parse_cache_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2038 | char **error) | |
2039 | { | |
2040 | int r; | |
2041 | ||
2042 | if (!at_least_one_arg(as, error)) | |
2043 | return -EINVAL; | |
2044 | ||
2045 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2046 | &ca->cache_dev); | |
2047 | if (r) { | |
2048 | *error = "Error opening cache device"; | |
2049 | return r; | |
2050 | } | |
2051 | ca->cache_sectors = get_dev_size(ca->cache_dev); | |
2052 | ||
2053 | return 0; | |
2054 | } | |
2055 | ||
2056 | static int parse_origin_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2057 | char **error) | |
2058 | { | |
2059 | int r; | |
2060 | ||
2061 | if (!at_least_one_arg(as, error)) | |
2062 | return -EINVAL; | |
2063 | ||
2064 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2065 | &ca->origin_dev); | |
2066 | if (r) { | |
2067 | *error = "Error opening origin device"; | |
2068 | return r; | |
2069 | } | |
2070 | ||
2071 | ca->origin_sectors = get_dev_size(ca->origin_dev); | |
2072 | if (ca->ti->len > ca->origin_sectors) { | |
2073 | *error = "Device size larger than cached device"; | |
2074 | return -EINVAL; | |
2075 | } | |
2076 | ||
2077 | return 0; | |
2078 | } | |
2079 | ||
2080 | static int parse_block_size(struct cache_args *ca, struct dm_arg_set *as, | |
2081 | char **error) | |
2082 | { | |
05473044 | 2083 | unsigned long block_size; |
c6b4fcba JT |
2084 | |
2085 | if (!at_least_one_arg(as, error)) | |
2086 | return -EINVAL; | |
2087 | ||
05473044 MS |
2088 | if (kstrtoul(dm_shift_arg(as), 10, &block_size) || !block_size || |
2089 | block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS || | |
2090 | block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS || | |
2091 | block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) { | |
c6b4fcba JT |
2092 | *error = "Invalid data block size"; |
2093 | return -EINVAL; | |
2094 | } | |
2095 | ||
05473044 | 2096 | if (block_size > ca->cache_sectors) { |
c6b4fcba JT |
2097 | *error = "Data block size is larger than the cache device"; |
2098 | return -EINVAL; | |
2099 | } | |
2100 | ||
05473044 | 2101 | ca->block_size = block_size; |
c6b4fcba JT |
2102 | |
2103 | return 0; | |
2104 | } | |
2105 | ||
2106 | static void init_features(struct cache_features *cf) | |
2107 | { | |
2108 | cf->mode = CM_WRITE; | |
2ee57d58 | 2109 | cf->io_mode = CM_IO_WRITEBACK; |
629d0a8a | 2110 | cf->metadata_version = 1; |
de7180ff | 2111 | cf->discard_passdown = true; |
c6b4fcba JT |
2112 | } |
2113 | ||
2114 | static int parse_features(struct cache_args *ca, struct dm_arg_set *as, | |
2115 | char **error) | |
2116 | { | |
5916a22b | 2117 | static const struct dm_arg _args[] = { |
de7180ff | 2118 | {0, 3, "Invalid number of cache feature arguments"}, |
c6b4fcba JT |
2119 | }; |
2120 | ||
af9313c3 | 2121 | int r, mode_ctr = 0; |
c6b4fcba JT |
2122 | unsigned argc; |
2123 | const char *arg; | |
2124 | struct cache_features *cf = &ca->features; | |
2125 | ||
2126 | init_features(cf); | |
2127 | ||
2128 | r = dm_read_arg_group(_args, as, &argc, error); | |
2129 | if (r) | |
2130 | return -EINVAL; | |
2131 | ||
2132 | while (argc--) { | |
2133 | arg = dm_shift_arg(as); | |
2134 | ||
af9313c3 | 2135 | if (!strcasecmp(arg, "writeback")) { |
2ee57d58 | 2136 | cf->io_mode = CM_IO_WRITEBACK; |
af9313c3 JP |
2137 | mode_ctr++; |
2138 | } | |
c6b4fcba | 2139 | |
af9313c3 | 2140 | else if (!strcasecmp(arg, "writethrough")) { |
2ee57d58 | 2141 | cf->io_mode = CM_IO_WRITETHROUGH; |
af9313c3 JP |
2142 | mode_ctr++; |
2143 | } | |
2ee57d58 | 2144 | |
af9313c3 | 2145 | else if (!strcasecmp(arg, "passthrough")) { |
2ee57d58 | 2146 | cf->io_mode = CM_IO_PASSTHROUGH; |
af9313c3 JP |
2147 | mode_ctr++; |
2148 | } | |
c6b4fcba | 2149 | |
629d0a8a JT |
2150 | else if (!strcasecmp(arg, "metadata2")) |
2151 | cf->metadata_version = 2; | |
2152 | ||
de7180ff MS |
2153 | else if (!strcasecmp(arg, "no_discard_passdown")) |
2154 | cf->discard_passdown = false; | |
2155 | ||
c6b4fcba JT |
2156 | else { |
2157 | *error = "Unrecognised cache feature requested"; | |
2158 | return -EINVAL; | |
2159 | } | |
2160 | } | |
2161 | ||
af9313c3 JP |
2162 | if (mode_ctr > 1) { |
2163 | *error = "Duplicate cache io_mode features requested"; | |
2164 | return -EINVAL; | |
2165 | } | |
2166 | ||
c6b4fcba JT |
2167 | return 0; |
2168 | } | |
2169 | ||
2170 | static int parse_policy(struct cache_args *ca, struct dm_arg_set *as, | |
2171 | char **error) | |
2172 | { | |
5916a22b | 2173 | static const struct dm_arg _args[] = { |
c6b4fcba JT |
2174 | {0, 1024, "Invalid number of policy arguments"}, |
2175 | }; | |
2176 | ||
2177 | int r; | |
2178 | ||
2179 | if (!at_least_one_arg(as, error)) | |
2180 | return -EINVAL; | |
2181 | ||
2182 | ca->policy_name = dm_shift_arg(as); | |
2183 | ||
2184 | r = dm_read_arg_group(_args, as, &ca->policy_argc, error); | |
2185 | if (r) | |
2186 | return -EINVAL; | |
2187 | ||
2188 | ca->policy_argv = (const char **)as->argv; | |
2189 | dm_consume_args(as, ca->policy_argc); | |
2190 | ||
2191 | return 0; | |
2192 | } | |
2193 | ||
2194 | static int parse_cache_args(struct cache_args *ca, int argc, char **argv, | |
2195 | char **error) | |
2196 | { | |
2197 | int r; | |
2198 | struct dm_arg_set as; | |
2199 | ||
2200 | as.argc = argc; | |
2201 | as.argv = argv; | |
2202 | ||
2203 | r = parse_metadata_dev(ca, &as, error); | |
2204 | if (r) | |
2205 | return r; | |
2206 | ||
2207 | r = parse_cache_dev(ca, &as, error); | |
2208 | if (r) | |
2209 | return r; | |
2210 | ||
2211 | r = parse_origin_dev(ca, &as, error); | |
2212 | if (r) | |
2213 | return r; | |
2214 | ||
2215 | r = parse_block_size(ca, &as, error); | |
2216 | if (r) | |
2217 | return r; | |
2218 | ||
2219 | r = parse_features(ca, &as, error); | |
2220 | if (r) | |
2221 | return r; | |
2222 | ||
2223 | r = parse_policy(ca, &as, error); | |
2224 | if (r) | |
2225 | return r; | |
2226 | ||
2227 | return 0; | |
2228 | } | |
2229 | ||
2230 | /*----------------------------------------------------------------*/ | |
2231 | ||
2232 | static struct kmem_cache *migration_cache; | |
2233 | ||
2c73c471 AK |
2234 | #define NOT_CORE_OPTION 1 |
2235 | ||
2f14f4b5 | 2236 | static int process_config_option(struct cache *cache, const char *key, const char *value) |
2c73c471 AK |
2237 | { |
2238 | unsigned long tmp; | |
2239 | ||
2f14f4b5 JT |
2240 | if (!strcasecmp(key, "migration_threshold")) { |
2241 | if (kstrtoul(value, 10, &tmp)) | |
2c73c471 AK |
2242 | return -EINVAL; |
2243 | ||
2244 | cache->migration_threshold = tmp; | |
2245 | return 0; | |
2246 | } | |
2247 | ||
2248 | return NOT_CORE_OPTION; | |
2249 | } | |
2250 | ||
2f14f4b5 JT |
2251 | static int set_config_value(struct cache *cache, const char *key, const char *value) |
2252 | { | |
2253 | int r = process_config_option(cache, key, value); | |
2254 | ||
2255 | if (r == NOT_CORE_OPTION) | |
2256 | r = policy_set_config_value(cache->policy, key, value); | |
2257 | ||
2258 | if (r) | |
2259 | DMWARN("bad config value for %s: %s", key, value); | |
2260 | ||
2261 | return r; | |
2262 | } | |
2263 | ||
2264 | static int set_config_values(struct cache *cache, int argc, const char **argv) | |
c6b4fcba JT |
2265 | { |
2266 | int r = 0; | |
2267 | ||
2268 | if (argc & 1) { | |
2269 | DMWARN("Odd number of policy arguments given but they should be <key> <value> pairs."); | |
2270 | return -EINVAL; | |
2271 | } | |
2272 | ||
2273 | while (argc) { | |
2f14f4b5 JT |
2274 | r = set_config_value(cache, argv[0], argv[1]); |
2275 | if (r) | |
2276 | break; | |
c6b4fcba JT |
2277 | |
2278 | argc -= 2; | |
2279 | argv += 2; | |
2280 | } | |
2281 | ||
2282 | return r; | |
2283 | } | |
2284 | ||
2285 | static int create_cache_policy(struct cache *cache, struct cache_args *ca, | |
2286 | char **error) | |
2287 | { | |
4cb3e1db MP |
2288 | struct dm_cache_policy *p = dm_cache_policy_create(ca->policy_name, |
2289 | cache->cache_size, | |
2290 | cache->origin_sectors, | |
2291 | cache->sectors_per_block); | |
2292 | if (IS_ERR(p)) { | |
c6b4fcba | 2293 | *error = "Error creating cache's policy"; |
4cb3e1db | 2294 | return PTR_ERR(p); |
c6b4fcba | 2295 | } |
4cb3e1db | 2296 | cache->policy = p; |
b29d4986 | 2297 | BUG_ON(!cache->policy); |
c6b4fcba | 2298 | |
2f14f4b5 | 2299 | return 0; |
c6b4fcba JT |
2300 | } |
2301 | ||
08b18451 | 2302 | /* |
2bb812df JT |
2303 | * We want the discard block size to be at least the size of the cache |
2304 | * block size and have no more than 2^14 discard blocks across the origin. | |
08b18451 JT |
2305 | */ |
2306 | #define MAX_DISCARD_BLOCKS (1 << 14) | |
2307 | ||
2308 | static bool too_many_discard_blocks(sector_t discard_block_size, | |
2309 | sector_t origin_size) | |
2310 | { | |
2311 | (void) sector_div(origin_size, discard_block_size); | |
2312 | ||
2313 | return origin_size > MAX_DISCARD_BLOCKS; | |
2314 | } | |
2315 | ||
2316 | static sector_t calculate_discard_block_size(sector_t cache_block_size, | |
2317 | sector_t origin_size) | |
2318 | { | |
2bb812df | 2319 | sector_t discard_block_size = cache_block_size; |
08b18451 JT |
2320 | |
2321 | if (origin_size) | |
2322 | while (too_many_discard_blocks(discard_block_size, origin_size)) | |
2323 | discard_block_size *= 2; | |
2324 | ||
2325 | return discard_block_size; | |
2326 | } | |
2327 | ||
d1d9220c JT |
2328 | static void set_cache_size(struct cache *cache, dm_cblock_t size) |
2329 | { | |
2330 | dm_block_t nr_blocks = from_cblock(size); | |
2331 | ||
2332 | if (nr_blocks > (1 << 20) && cache->cache_size != size) | |
2333 | DMWARN_LIMIT("You have created a cache device with a lot of individual cache blocks (%llu)\n" | |
2334 | "All these mappings can consume a lot of kernel memory, and take some time to read/write.\n" | |
2335 | "Please consider increasing the cache block size to reduce the overall cache block count.", | |
2336 | (unsigned long long) nr_blocks); | |
2337 | ||
2338 | cache->cache_size = size; | |
2339 | } | |
2340 | ||
f8350daf | 2341 | #define DEFAULT_MIGRATION_THRESHOLD 2048 |
c6b4fcba | 2342 | |
c6b4fcba JT |
2343 | static int cache_create(struct cache_args *ca, struct cache **result) |
2344 | { | |
2345 | int r = 0; | |
2346 | char **error = &ca->ti->error; | |
2347 | struct cache *cache; | |
2348 | struct dm_target *ti = ca->ti; | |
2349 | dm_block_t origin_blocks; | |
2350 | struct dm_cache_metadata *cmd; | |
2351 | bool may_format = ca->features.mode == CM_WRITE; | |
2352 | ||
2353 | cache = kzalloc(sizeof(*cache), GFP_KERNEL); | |
2354 | if (!cache) | |
2355 | return -ENOMEM; | |
2356 | ||
2357 | cache->ti = ca->ti; | |
2358 | ti->private = cache; | |
69596f55 | 2359 | ti->accounts_remapped_io = true; |
c6b4fcba JT |
2360 | ti->num_flush_bios = 2; |
2361 | ti->flush_supported = true; | |
2362 | ||
2363 | ti->num_discard_bios = 1; | |
2364 | ti->discards_supported = true; | |
c6b4fcba | 2365 | |
693b960e | 2366 | ti->per_io_data_size = sizeof(struct per_bio_data); |
c6b4fcba | 2367 | |
693b960e | 2368 | cache->features = ca->features; |
2df3bae9 MS |
2369 | if (writethrough_mode(cache)) { |
2370 | /* Create bioset for writethrough bios issued to origin */ | |
6f1c819c KO |
2371 | r = bioset_init(&cache->bs, BIO_POOL_SIZE, 0, 0); |
2372 | if (r) | |
2df3bae9 MS |
2373 | goto bad; |
2374 | } | |
2375 | ||
c6b4fcba JT |
2376 | cache->metadata_dev = ca->metadata_dev; |
2377 | cache->origin_dev = ca->origin_dev; | |
2378 | cache->cache_dev = ca->cache_dev; | |
2379 | ||
2380 | ca->metadata_dev = ca->origin_dev = ca->cache_dev = NULL; | |
2381 | ||
c6b4fcba | 2382 | origin_blocks = cache->origin_sectors = ca->origin_sectors; |
414dd67d | 2383 | origin_blocks = block_div(origin_blocks, ca->block_size); |
c6b4fcba JT |
2384 | cache->origin_blocks = to_oblock(origin_blocks); |
2385 | ||
2386 | cache->sectors_per_block = ca->block_size; | |
2387 | if (dm_set_target_max_io_len(ti, cache->sectors_per_block)) { | |
2388 | r = -EINVAL; | |
2389 | goto bad; | |
2390 | } | |
2391 | ||
2392 | if (ca->block_size & (ca->block_size - 1)) { | |
2393 | dm_block_t cache_size = ca->cache_sectors; | |
2394 | ||
2395 | cache->sectors_per_block_shift = -1; | |
414dd67d | 2396 | cache_size = block_div(cache_size, ca->block_size); |
d1d9220c | 2397 | set_cache_size(cache, to_cblock(cache_size)); |
c6b4fcba JT |
2398 | } else { |
2399 | cache->sectors_per_block_shift = __ffs(ca->block_size); | |
d1d9220c | 2400 | set_cache_size(cache, to_cblock(ca->cache_sectors >> cache->sectors_per_block_shift)); |
c6b4fcba JT |
2401 | } |
2402 | ||
2403 | r = create_cache_policy(cache, ca, error); | |
2404 | if (r) | |
2405 | goto bad; | |
2f14f4b5 | 2406 | |
c6b4fcba | 2407 | cache->policy_nr_args = ca->policy_argc; |
2f14f4b5 JT |
2408 | cache->migration_threshold = DEFAULT_MIGRATION_THRESHOLD; |
2409 | ||
2410 | r = set_config_values(cache, ca->policy_argc, ca->policy_argv); | |
2411 | if (r) { | |
2412 | *error = "Error setting cache policy's config values"; | |
2413 | goto bad; | |
2414 | } | |
c6b4fcba JT |
2415 | |
2416 | cmd = dm_cache_metadata_open(cache->metadata_dev->bdev, | |
2417 | ca->block_size, may_format, | |
629d0a8a JT |
2418 | dm_cache_policy_get_hint_size(cache->policy), |
2419 | ca->features.metadata_version); | |
c6b4fcba JT |
2420 | if (IS_ERR(cmd)) { |
2421 | *error = "Error creating metadata object"; | |
2422 | r = PTR_ERR(cmd); | |
2423 | goto bad; | |
2424 | } | |
2425 | cache->cmd = cmd; | |
028ae9f7 JT |
2426 | set_cache_mode(cache, CM_WRITE); |
2427 | if (get_cache_mode(cache) != CM_WRITE) { | |
2428 | *error = "Unable to get write access to metadata, please check/repair metadata."; | |
2429 | r = -EINVAL; | |
2430 | goto bad; | |
2431 | } | |
c6b4fcba | 2432 | |
8e3c3827 | 2433 | if (passthrough_mode(cache)) { |
2ee57d58 JT |
2434 | bool all_clean; |
2435 | ||
2436 | r = dm_cache_metadata_all_clean(cache->cmd, &all_clean); | |
2437 | if (r) { | |
2438 | *error = "dm_cache_metadata_all_clean() failed"; | |
2439 | goto bad; | |
2440 | } | |
2441 | ||
2442 | if (!all_clean) { | |
2443 | *error = "Cannot enter passthrough mode unless all blocks are clean"; | |
2444 | r = -EINVAL; | |
2445 | goto bad; | |
2446 | } | |
b29d4986 JT |
2447 | |
2448 | policy_allow_migrations(cache->policy, false); | |
2ee57d58 JT |
2449 | } |
2450 | ||
c6b4fcba JT |
2451 | spin_lock_init(&cache->lock); |
2452 | bio_list_init(&cache->deferred_bios); | |
a59db676 JT |
2453 | atomic_set(&cache->nr_allocated_migrations, 0); |
2454 | atomic_set(&cache->nr_io_migrations, 0); | |
c6b4fcba JT |
2455 | init_waitqueue_head(&cache->migration_wait); |
2456 | ||
fa4d683a | 2457 | r = -ENOMEM; |
44fa816b | 2458 | atomic_set(&cache->nr_dirty, 0); |
c6b4fcba JT |
2459 | cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size)); |
2460 | if (!cache->dirty_bitset) { | |
2461 | *error = "could not allocate dirty bitset"; | |
2462 | goto bad; | |
2463 | } | |
2464 | clear_bitset(cache->dirty_bitset, from_cblock(cache->cache_size)); | |
2465 | ||
08b18451 JT |
2466 | cache->discard_block_size = |
2467 | calculate_discard_block_size(cache->sectors_per_block, | |
2468 | cache->origin_sectors); | |
2572629a JT |
2469 | cache->discard_nr_blocks = to_dblock(dm_sector_div_up(cache->origin_sectors, |
2470 | cache->discard_block_size)); | |
1bad9bc4 | 2471 | cache->discard_bitset = alloc_bitset(from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2472 | if (!cache->discard_bitset) { |
2473 | *error = "could not allocate discard bitset"; | |
2474 | goto bad; | |
2475 | } | |
1bad9bc4 | 2476 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2477 | |
2478 | cache->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle); | |
2479 | if (IS_ERR(cache->copier)) { | |
2480 | *error = "could not create kcopyd client"; | |
2481 | r = PTR_ERR(cache->copier); | |
2482 | goto bad; | |
2483 | } | |
2484 | ||
b29d4986 | 2485 | cache->wq = alloc_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM, 0); |
c6b4fcba JT |
2486 | if (!cache->wq) { |
2487 | *error = "could not create workqueue for metadata object"; | |
2488 | goto bad; | |
2489 | } | |
b29d4986 | 2490 | INIT_WORK(&cache->deferred_bio_worker, process_deferred_bios); |
b29d4986 | 2491 | INIT_WORK(&cache->migration_worker, check_migrations); |
c6b4fcba | 2492 | INIT_DELAYED_WORK(&cache->waker, do_waker); |
c6b4fcba | 2493 | |
b29d4986 | 2494 | cache->prison = dm_bio_prison_create_v2(cache->wq); |
c6b4fcba JT |
2495 | if (!cache->prison) { |
2496 | *error = "could not create bio prison"; | |
2497 | goto bad; | |
2498 | } | |
2499 | ||
6f1c819c KO |
2500 | r = mempool_init_slab_pool(&cache->migration_pool, MIGRATION_POOL_SIZE, |
2501 | migration_cache); | |
2502 | if (r) { | |
c6b4fcba JT |
2503 | *error = "Error creating cache's migration mempool"; |
2504 | goto bad; | |
2505 | } | |
2506 | ||
c6b4fcba JT |
2507 | cache->need_tick_bio = true; |
2508 | cache->sized = false; | |
65790ff9 | 2509 | cache->invalidate = false; |
c6b4fcba JT |
2510 | cache->commit_requested = false; |
2511 | cache->loaded_mappings = false; | |
2512 | cache->loaded_discards = false; | |
2513 | ||
2514 | load_stats(cache); | |
2515 | ||
2516 | atomic_set(&cache->stats.demotion, 0); | |
2517 | atomic_set(&cache->stats.promotion, 0); | |
2518 | atomic_set(&cache->stats.copies_avoided, 0); | |
2519 | atomic_set(&cache->stats.cache_cell_clash, 0); | |
2520 | atomic_set(&cache->stats.commit_count, 0); | |
2521 | atomic_set(&cache->stats.discard_count, 0); | |
2522 | ||
65790ff9 JT |
2523 | spin_lock_init(&cache->invalidation_lock); |
2524 | INIT_LIST_HEAD(&cache->invalidation_requests); | |
2525 | ||
b29d4986 JT |
2526 | batcher_init(&cache->committer, commit_op, cache, |
2527 | issue_op, cache, cache->wq); | |
dc4fa29f | 2528 | dm_iot_init(&cache->tracker); |
066dbaa3 | 2529 | |
b29d4986 JT |
2530 | init_rwsem(&cache->background_work_lock); |
2531 | prevent_background_work(cache); | |
2532 | ||
c6b4fcba JT |
2533 | *result = cache; |
2534 | return 0; | |
c6b4fcba JT |
2535 | bad: |
2536 | destroy(cache); | |
2537 | return r; | |
2538 | } | |
2539 | ||
2540 | static int copy_ctr_args(struct cache *cache, int argc, const char **argv) | |
2541 | { | |
2542 | unsigned i; | |
2543 | const char **copy; | |
2544 | ||
2545 | copy = kcalloc(argc, sizeof(*copy), GFP_KERNEL); | |
2546 | if (!copy) | |
2547 | return -ENOMEM; | |
2548 | for (i = 0; i < argc; i++) { | |
2549 | copy[i] = kstrdup(argv[i], GFP_KERNEL); | |
2550 | if (!copy[i]) { | |
2551 | while (i--) | |
2552 | kfree(copy[i]); | |
2553 | kfree(copy); | |
2554 | return -ENOMEM; | |
2555 | } | |
2556 | } | |
2557 | ||
2558 | cache->nr_ctr_args = argc; | |
2559 | cache->ctr_args = copy; | |
2560 | ||
2561 | return 0; | |
2562 | } | |
2563 | ||
2564 | static int cache_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
2565 | { | |
2566 | int r = -EINVAL; | |
2567 | struct cache_args *ca; | |
2568 | struct cache *cache = NULL; | |
2569 | ||
2570 | ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
2571 | if (!ca) { | |
2572 | ti->error = "Error allocating memory for cache"; | |
2573 | return -ENOMEM; | |
2574 | } | |
2575 | ca->ti = ti; | |
2576 | ||
2577 | r = parse_cache_args(ca, argc, argv, &ti->error); | |
2578 | if (r) | |
2579 | goto out; | |
2580 | ||
2581 | r = cache_create(ca, &cache); | |
617a0b89 HM |
2582 | if (r) |
2583 | goto out; | |
c6b4fcba JT |
2584 | |
2585 | r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3); | |
2586 | if (r) { | |
2587 | destroy(cache); | |
2588 | goto out; | |
2589 | } | |
2590 | ||
2591 | ti->private = cache; | |
c6b4fcba JT |
2592 | out: |
2593 | destroy_cache_args(ca); | |
2594 | return r; | |
2595 | } | |
2596 | ||
651f5fa2 JT |
2597 | /*----------------------------------------------------------------*/ |
2598 | ||
2599 | static int cache_map(struct dm_target *ti, struct bio *bio) | |
c6b4fcba | 2600 | { |
651f5fa2 JT |
2601 | struct cache *cache = ti->private; |
2602 | ||
c6b4fcba | 2603 | int r; |
b29d4986 | 2604 | bool commit_needed; |
c6b4fcba | 2605 | dm_oblock_t block = get_bio_block(cache, bio); |
c6b4fcba | 2606 | |
693b960e | 2607 | init_per_bio_data(bio); |
e893fba9 | 2608 | if (unlikely(from_oblock(block) >= from_oblock(cache->origin_blocks))) { |
c6b4fcba JT |
2609 | /* |
2610 | * This can only occur if the io goes to a partial block at | |
2611 | * the end of the origin device. We don't cache these. | |
2612 | * Just remap to the origin and carry on. | |
2613 | */ | |
e893fba9 | 2614 | remap_to_origin(cache, bio); |
651f5fa2 | 2615 | accounted_begin(cache, bio); |
c6b4fcba JT |
2616 | return DM_MAPIO_REMAPPED; |
2617 | } | |
2618 | ||
651f5fa2 | 2619 | if (discard_or_flush(bio)) { |
c6b4fcba JT |
2620 | defer_bio(cache, bio); |
2621 | return DM_MAPIO_SUBMITTED; | |
2622 | } | |
2623 | ||
b29d4986 JT |
2624 | r = map_bio(cache, bio, block, &commit_needed); |
2625 | if (commit_needed) | |
2626 | schedule_commit(&cache->committer); | |
c6b4fcba | 2627 | |
2ee57d58 | 2628 | return r; |
c6b4fcba JT |
2629 | } |
2630 | ||
693b960e | 2631 | static int cache_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *error) |
c6b4fcba JT |
2632 | { |
2633 | struct cache *cache = ti->private; | |
2634 | unsigned long flags; | |
693b960e | 2635 | struct per_bio_data *pb = get_per_bio_data(bio); |
c6b4fcba JT |
2636 | |
2637 | if (pb->tick) { | |
fba10109 | 2638 | policy_tick(cache->policy, false); |
c6b4fcba JT |
2639 | |
2640 | spin_lock_irqsave(&cache->lock, flags); | |
2641 | cache->need_tick_bio = true; | |
2642 | spin_unlock_irqrestore(&cache->lock, flags); | |
2643 | } | |
2644 | ||
b29d4986 | 2645 | bio_drop_shared_lock(cache, bio); |
066dbaa3 | 2646 | accounted_complete(cache, bio); |
c6b4fcba | 2647 | |
1be56909 | 2648 | return DM_ENDIO_DONE; |
c6b4fcba JT |
2649 | } |
2650 | ||
2651 | static int write_dirty_bitset(struct cache *cache) | |
2652 | { | |
629d0a8a | 2653 | int r; |
c6b4fcba | 2654 | |
028ae9f7 JT |
2655 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
2656 | return -EINVAL; | |
2657 | ||
629d0a8a JT |
2658 | r = dm_cache_set_dirty_bits(cache->cmd, from_cblock(cache->cache_size), cache->dirty_bitset); |
2659 | if (r) | |
2660 | metadata_operation_failed(cache, "dm_cache_set_dirty_bits", r); | |
c6b4fcba | 2661 | |
629d0a8a | 2662 | return r; |
c6b4fcba JT |
2663 | } |
2664 | ||
2665 | static int write_discard_bitset(struct cache *cache) | |
2666 | { | |
2667 | unsigned i, r; | |
2668 | ||
028ae9f7 JT |
2669 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
2670 | return -EINVAL; | |
2671 | ||
1bad9bc4 JT |
2672 | r = dm_cache_discard_bitset_resize(cache->cmd, cache->discard_block_size, |
2673 | cache->discard_nr_blocks); | |
c6b4fcba | 2674 | if (r) { |
b61d9509 | 2675 | DMERR("%s: could not resize on-disk discard bitset", cache_device_name(cache)); |
028ae9f7 | 2676 | metadata_operation_failed(cache, "dm_cache_discard_bitset_resize", r); |
c6b4fcba JT |
2677 | return r; |
2678 | } | |
2679 | ||
1bad9bc4 JT |
2680 | for (i = 0; i < from_dblock(cache->discard_nr_blocks); i++) { |
2681 | r = dm_cache_set_discard(cache->cmd, to_dblock(i), | |
2682 | is_discarded(cache, to_dblock(i))); | |
028ae9f7 JT |
2683 | if (r) { |
2684 | metadata_operation_failed(cache, "dm_cache_set_discard", r); | |
c6b4fcba | 2685 | return r; |
028ae9f7 JT |
2686 | } |
2687 | } | |
2688 | ||
2689 | return 0; | |
2690 | } | |
2691 | ||
2692 | static int write_hints(struct cache *cache) | |
2693 | { | |
2694 | int r; | |
2695 | ||
2696 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
2697 | return -EINVAL; | |
2698 | ||
2699 | r = dm_cache_write_hints(cache->cmd, cache->policy); | |
2700 | if (r) { | |
2701 | metadata_operation_failed(cache, "dm_cache_write_hints", r); | |
2702 | return r; | |
c6b4fcba JT |
2703 | } |
2704 | ||
2705 | return 0; | |
2706 | } | |
2707 | ||
c6b4fcba JT |
2708 | /* |
2709 | * returns true on success | |
2710 | */ | |
2711 | static bool sync_metadata(struct cache *cache) | |
2712 | { | |
2713 | int r1, r2, r3, r4; | |
2714 | ||
2715 | r1 = write_dirty_bitset(cache); | |
2716 | if (r1) | |
b61d9509 | 2717 | DMERR("%s: could not write dirty bitset", cache_device_name(cache)); |
c6b4fcba JT |
2718 | |
2719 | r2 = write_discard_bitset(cache); | |
2720 | if (r2) | |
b61d9509 | 2721 | DMERR("%s: could not write discard bitset", cache_device_name(cache)); |
c6b4fcba JT |
2722 | |
2723 | save_stats(cache); | |
2724 | ||
028ae9f7 | 2725 | r3 = write_hints(cache); |
c6b4fcba | 2726 | if (r3) |
b61d9509 | 2727 | DMERR("%s: could not write hints", cache_device_name(cache)); |
c6b4fcba JT |
2728 | |
2729 | /* | |
2730 | * If writing the above metadata failed, we still commit, but don't | |
2731 | * set the clean shutdown flag. This will effectively force every | |
2732 | * dirty bit to be set on reload. | |
2733 | */ | |
028ae9f7 | 2734 | r4 = commit(cache, !r1 && !r2 && !r3); |
c6b4fcba | 2735 | if (r4) |
b61d9509 | 2736 | DMERR("%s: could not write cache metadata", cache_device_name(cache)); |
c6b4fcba JT |
2737 | |
2738 | return !r1 && !r2 && !r3 && !r4; | |
2739 | } | |
2740 | ||
2741 | static void cache_postsuspend(struct dm_target *ti) | |
2742 | { | |
2743 | struct cache *cache = ti->private; | |
2744 | ||
b29d4986 JT |
2745 | prevent_background_work(cache); |
2746 | BUG_ON(atomic_read(&cache->nr_io_migrations)); | |
2747 | ||
7cdf6a0a MP |
2748 | cancel_delayed_work_sync(&cache->waker); |
2749 | drain_workqueue(cache->wq); | |
701e03e4 | 2750 | WARN_ON(cache->tracker.in_flight); |
b29d4986 JT |
2751 | |
2752 | /* | |
2753 | * If it's a flush suspend there won't be any deferred bios, so this | |
2754 | * call is harmless. | |
2755 | */ | |
651f5fa2 | 2756 | requeue_deferred_bios(cache); |
c6b4fcba | 2757 | |
028ae9f7 JT |
2758 | if (get_cache_mode(cache) == CM_WRITE) |
2759 | (void) sync_metadata(cache); | |
c6b4fcba JT |
2760 | } |
2761 | ||
2762 | static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock, | |
2763 | bool dirty, uint32_t hint, bool hint_valid) | |
2764 | { | |
c6b4fcba JT |
2765 | struct cache *cache = context; |
2766 | ||
449b668c JT |
2767 | if (dirty) { |
2768 | set_bit(from_cblock(cblock), cache->dirty_bitset); | |
2769 | atomic_inc(&cache->nr_dirty); | |
2770 | } else | |
2771 | clear_bit(from_cblock(cblock), cache->dirty_bitset); | |
2772 | ||
b7770923 | 2773 | return policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid); |
c6b4fcba JT |
2774 | } |
2775 | ||
3e2e1c30 JT |
2776 | /* |
2777 | * The discard block size in the on disk metadata is not | |
5c29e784 | 2778 | * necessarily the same as we're currently using. So we have to |
3e2e1c30 JT |
2779 | * be careful to only set the discarded attribute if we know it |
2780 | * covers a complete block of the new size. | |
2781 | */ | |
2782 | struct discard_load_info { | |
2783 | struct cache *cache; | |
2784 | ||
2785 | /* | |
2786 | * These blocks are sized using the on disk dblock size, rather | |
2787 | * than the current one. | |
2788 | */ | |
2789 | dm_block_t block_size; | |
2790 | dm_block_t discard_begin, discard_end; | |
2791 | }; | |
2792 | ||
2793 | static void discard_load_info_init(struct cache *cache, | |
2794 | struct discard_load_info *li) | |
2795 | { | |
2796 | li->cache = cache; | |
2797 | li->discard_begin = li->discard_end = 0; | |
2798 | } | |
2799 | ||
2800 | static void set_discard_range(struct discard_load_info *li) | |
2801 | { | |
2802 | sector_t b, e; | |
2803 | ||
2804 | if (li->discard_begin == li->discard_end) | |
2805 | return; | |
2806 | ||
2807 | /* | |
2808 | * Convert to sectors. | |
2809 | */ | |
2810 | b = li->discard_begin * li->block_size; | |
2811 | e = li->discard_end * li->block_size; | |
2812 | ||
2813 | /* | |
2814 | * Then convert back to the current dblock size. | |
2815 | */ | |
2816 | b = dm_sector_div_up(b, li->cache->discard_block_size); | |
2817 | sector_div(e, li->cache->discard_block_size); | |
2818 | ||
2819 | /* | |
2820 | * The origin may have shrunk, so we need to check we're still in | |
2821 | * bounds. | |
2822 | */ | |
2823 | if (e > from_dblock(li->cache->discard_nr_blocks)) | |
2824 | e = from_dblock(li->cache->discard_nr_blocks); | |
2825 | ||
2826 | for (; b < e; b++) | |
2827 | set_discard(li->cache, to_dblock(b)); | |
2828 | } | |
2829 | ||
c6b4fcba | 2830 | static int load_discard(void *context, sector_t discard_block_size, |
1bad9bc4 | 2831 | dm_dblock_t dblock, bool discard) |
c6b4fcba | 2832 | { |
3e2e1c30 | 2833 | struct discard_load_info *li = context; |
c6b4fcba | 2834 | |
3e2e1c30 | 2835 | li->block_size = discard_block_size; |
1bad9bc4 | 2836 | |
3e2e1c30 JT |
2837 | if (discard) { |
2838 | if (from_dblock(dblock) == li->discard_end) | |
2839 | /* | |
2840 | * We're already in a discard range, just extend it. | |
2841 | */ | |
2842 | li->discard_end = li->discard_end + 1ULL; | |
2843 | ||
2844 | else { | |
2845 | /* | |
2846 | * Emit the old range and start a new one. | |
2847 | */ | |
2848 | set_discard_range(li); | |
2849 | li->discard_begin = from_dblock(dblock); | |
2850 | li->discard_end = li->discard_begin + 1ULL; | |
2851 | } | |
2852 | } else { | |
2853 | set_discard_range(li); | |
2854 | li->discard_begin = li->discard_end = 0; | |
2855 | } | |
c6b4fcba JT |
2856 | |
2857 | return 0; | |
2858 | } | |
2859 | ||
f494a9c6 JT |
2860 | static dm_cblock_t get_cache_dev_size(struct cache *cache) |
2861 | { | |
2862 | sector_t size = get_dev_size(cache->cache_dev); | |
2863 | (void) sector_div(size, cache->sectors_per_block); | |
2864 | return to_cblock(size); | |
2865 | } | |
2866 | ||
2867 | static bool can_resize(struct cache *cache, dm_cblock_t new_size) | |
2868 | { | |
5d07384a MS |
2869 | if (from_cblock(new_size) > from_cblock(cache->cache_size)) { |
2870 | if (cache->sized) { | |
2871 | DMERR("%s: unable to extend cache due to missing cache table reload", | |
2872 | cache_device_name(cache)); | |
2873 | return false; | |
2874 | } | |
2875 | } | |
f494a9c6 JT |
2876 | |
2877 | /* | |
2878 | * We can't drop a dirty block when shrinking the cache. | |
2879 | */ | |
2880 | while (from_cblock(new_size) < from_cblock(cache->cache_size)) { | |
2881 | new_size = to_cblock(from_cblock(new_size) + 1); | |
2882 | if (is_dirty(cache, new_size)) { | |
b61d9509 MS |
2883 | DMERR("%s: unable to shrink cache; cache block %llu is dirty", |
2884 | cache_device_name(cache), | |
f494a9c6 JT |
2885 | (unsigned long long) from_cblock(new_size)); |
2886 | return false; | |
2887 | } | |
2888 | } | |
2889 | ||
2890 | return true; | |
2891 | } | |
2892 | ||
2893 | static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size) | |
2894 | { | |
2895 | int r; | |
2896 | ||
08844800 | 2897 | r = dm_cache_resize(cache->cmd, new_size); |
f494a9c6 | 2898 | if (r) { |
b61d9509 | 2899 | DMERR("%s: could not resize cache metadata", cache_device_name(cache)); |
028ae9f7 | 2900 | metadata_operation_failed(cache, "dm_cache_resize", r); |
f494a9c6 JT |
2901 | return r; |
2902 | } | |
2903 | ||
d1d9220c | 2904 | set_cache_size(cache, new_size); |
f494a9c6 JT |
2905 | |
2906 | return 0; | |
2907 | } | |
2908 | ||
c6b4fcba JT |
2909 | static int cache_preresume(struct dm_target *ti) |
2910 | { | |
2911 | int r = 0; | |
2912 | struct cache *cache = ti->private; | |
f494a9c6 | 2913 | dm_cblock_t csize = get_cache_dev_size(cache); |
c6b4fcba JT |
2914 | |
2915 | /* | |
2916 | * Check to see if the cache has resized. | |
2917 | */ | |
f494a9c6 JT |
2918 | if (!cache->sized) { |
2919 | r = resize_cache_dev(cache, csize); | |
2920 | if (r) | |
c6b4fcba | 2921 | return r; |
c6b4fcba JT |
2922 | |
2923 | cache->sized = true; | |
f494a9c6 JT |
2924 | |
2925 | } else if (csize != cache->cache_size) { | |
2926 | if (!can_resize(cache, csize)) | |
2927 | return -EINVAL; | |
2928 | ||
2929 | r = resize_cache_dev(cache, csize); | |
2930 | if (r) | |
2931 | return r; | |
c6b4fcba JT |
2932 | } |
2933 | ||
2934 | if (!cache->loaded_mappings) { | |
ea2dd8c1 | 2935 | r = dm_cache_load_mappings(cache->cmd, cache->policy, |
c6b4fcba JT |
2936 | load_mapping, cache); |
2937 | if (r) { | |
b61d9509 | 2938 | DMERR("%s: could not load cache mappings", cache_device_name(cache)); |
028ae9f7 | 2939 | metadata_operation_failed(cache, "dm_cache_load_mappings", r); |
c6b4fcba JT |
2940 | return r; |
2941 | } | |
2942 | ||
2943 | cache->loaded_mappings = true; | |
2944 | } | |
2945 | ||
2946 | if (!cache->loaded_discards) { | |
3e2e1c30 JT |
2947 | struct discard_load_info li; |
2948 | ||
2949 | /* | |
2950 | * The discard bitset could have been resized, or the | |
2951 | * discard block size changed. To be safe we start by | |
2952 | * setting every dblock to not discarded. | |
2953 | */ | |
2954 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); | |
2955 | ||
2956 | discard_load_info_init(cache, &li); | |
2957 | r = dm_cache_load_discards(cache->cmd, load_discard, &li); | |
c6b4fcba | 2958 | if (r) { |
b61d9509 | 2959 | DMERR("%s: could not load origin discards", cache_device_name(cache)); |
028ae9f7 | 2960 | metadata_operation_failed(cache, "dm_cache_load_discards", r); |
c6b4fcba JT |
2961 | return r; |
2962 | } | |
3e2e1c30 | 2963 | set_discard_range(&li); |
c6b4fcba JT |
2964 | |
2965 | cache->loaded_discards = true; | |
2966 | } | |
2967 | ||
2968 | return r; | |
2969 | } | |
2970 | ||
2971 | static void cache_resume(struct dm_target *ti) | |
2972 | { | |
2973 | struct cache *cache = ti->private; | |
2974 | ||
2975 | cache->need_tick_bio = true; | |
b29d4986 | 2976 | allow_background_work(cache); |
c6b4fcba JT |
2977 | do_waker(&cache->waker.work); |
2978 | } | |
2979 | ||
de7180ff MS |
2980 | static void emit_flags(struct cache *cache, char *result, |
2981 | unsigned maxlen, ssize_t *sz_ptr) | |
2982 | { | |
2983 | ssize_t sz = *sz_ptr; | |
2984 | struct cache_features *cf = &cache->features; | |
2985 | unsigned count = (cf->metadata_version == 2) + !cf->discard_passdown + 1; | |
2986 | ||
2987 | DMEMIT("%u ", count); | |
2988 | ||
2989 | if (cf->metadata_version == 2) | |
2990 | DMEMIT("metadata2 "); | |
2991 | ||
2992 | if (writethrough_mode(cache)) | |
2993 | DMEMIT("writethrough "); | |
2994 | ||
2995 | else if (passthrough_mode(cache)) | |
2996 | DMEMIT("passthrough "); | |
2997 | ||
2998 | else if (writeback_mode(cache)) | |
2999 | DMEMIT("writeback "); | |
3000 | ||
3001 | else { | |
3002 | DMEMIT("unknown "); | |
3003 | DMERR("%s: internal error: unknown io mode: %d", | |
3004 | cache_device_name(cache), (int) cf->io_mode); | |
3005 | } | |
3006 | ||
3007 | if (!cf->discard_passdown) | |
3008 | DMEMIT("no_discard_passdown "); | |
3009 | ||
3010 | *sz_ptr = sz; | |
3011 | } | |
3012 | ||
c6b4fcba JT |
3013 | /* |
3014 | * Status format: | |
3015 | * | |
6a388618 MS |
3016 | * <metadata block size> <#used metadata blocks>/<#total metadata blocks> |
3017 | * <cache block size> <#used cache blocks>/<#total cache blocks> | |
c6b4fcba | 3018 | * <#read hits> <#read misses> <#write hits> <#write misses> |
6a388618 | 3019 | * <#demotions> <#promotions> <#dirty> |
c6b4fcba JT |
3020 | * <#features> <features>* |
3021 | * <#core args> <core args> | |
255eac20 | 3022 | * <policy name> <#policy args> <policy args>* <cache metadata mode> <needs_check> |
c6b4fcba JT |
3023 | */ |
3024 | static void cache_status(struct dm_target *ti, status_type_t type, | |
3025 | unsigned status_flags, char *result, unsigned maxlen) | |
3026 | { | |
3027 | int r = 0; | |
3028 | unsigned i; | |
3029 | ssize_t sz = 0; | |
3030 | dm_block_t nr_free_blocks_metadata = 0; | |
3031 | dm_block_t nr_blocks_metadata = 0; | |
3032 | char buf[BDEVNAME_SIZE]; | |
3033 | struct cache *cache = ti->private; | |
3034 | dm_cblock_t residency; | |
d14fcf3d | 3035 | bool needs_check; |
c6b4fcba JT |
3036 | |
3037 | switch (type) { | |
3038 | case STATUSTYPE_INFO: | |
028ae9f7 JT |
3039 | if (get_cache_mode(cache) == CM_FAIL) { |
3040 | DMEMIT("Fail"); | |
3041 | break; | |
c6b4fcba JT |
3042 | } |
3043 | ||
028ae9f7 JT |
3044 | /* Commit to ensure statistics aren't out-of-date */ |
3045 | if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) | |
3046 | (void) commit(cache, false); | |
3047 | ||
b61d9509 | 3048 | r = dm_cache_get_free_metadata_block_count(cache->cmd, &nr_free_blocks_metadata); |
c6b4fcba | 3049 | if (r) { |
b61d9509 MS |
3050 | DMERR("%s: dm_cache_get_free_metadata_block_count returned %d", |
3051 | cache_device_name(cache), r); | |
c6b4fcba JT |
3052 | goto err; |
3053 | } | |
3054 | ||
3055 | r = dm_cache_get_metadata_dev_size(cache->cmd, &nr_blocks_metadata); | |
3056 | if (r) { | |
b61d9509 MS |
3057 | DMERR("%s: dm_cache_get_metadata_dev_size returned %d", |
3058 | cache_device_name(cache), r); | |
c6b4fcba JT |
3059 | goto err; |
3060 | } | |
3061 | ||
3062 | residency = policy_residency(cache->policy); | |
3063 | ||
ca763d0a | 3064 | DMEMIT("%u %llu/%llu %llu %llu/%llu %u %u %u %u %u %u %lu ", |
895b47d7 | 3065 | (unsigned)DM_CACHE_METADATA_BLOCK_SIZE, |
c6b4fcba JT |
3066 | (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), |
3067 | (unsigned long long)nr_blocks_metadata, | |
ca763d0a | 3068 | (unsigned long long)cache->sectors_per_block, |
6a388618 MS |
3069 | (unsigned long long) from_cblock(residency), |
3070 | (unsigned long long) from_cblock(cache->cache_size), | |
c6b4fcba JT |
3071 | (unsigned) atomic_read(&cache->stats.read_hit), |
3072 | (unsigned) atomic_read(&cache->stats.read_miss), | |
3073 | (unsigned) atomic_read(&cache->stats.write_hit), | |
3074 | (unsigned) atomic_read(&cache->stats.write_miss), | |
3075 | (unsigned) atomic_read(&cache->stats.demotion), | |
3076 | (unsigned) atomic_read(&cache->stats.promotion), | |
44fa816b | 3077 | (unsigned long) atomic_read(&cache->nr_dirty)); |
c6b4fcba | 3078 | |
de7180ff | 3079 | emit_flags(cache, result, maxlen, &sz); |
c6b4fcba JT |
3080 | |
3081 | DMEMIT("2 migration_threshold %llu ", (unsigned long long) cache->migration_threshold); | |
2e68c4e6 MS |
3082 | |
3083 | DMEMIT("%s ", dm_cache_policy_get_name(cache->policy)); | |
c6b4fcba | 3084 | if (sz < maxlen) { |
028ae9f7 | 3085 | r = policy_emit_config_values(cache->policy, result, maxlen, &sz); |
c6b4fcba | 3086 | if (r) |
b61d9509 MS |
3087 | DMERR("%s: policy_emit_config_values returned %d", |
3088 | cache_device_name(cache), r); | |
c6b4fcba JT |
3089 | } |
3090 | ||
028ae9f7 JT |
3091 | if (get_cache_mode(cache) == CM_READ_ONLY) |
3092 | DMEMIT("ro "); | |
3093 | else | |
3094 | DMEMIT("rw "); | |
3095 | ||
d14fcf3d JT |
3096 | r = dm_cache_metadata_needs_check(cache->cmd, &needs_check); |
3097 | ||
3098 | if (r || needs_check) | |
255eac20 MS |
3099 | DMEMIT("needs_check "); |
3100 | else | |
3101 | DMEMIT("- "); | |
3102 | ||
c6b4fcba JT |
3103 | break; |
3104 | ||
3105 | case STATUSTYPE_TABLE: | |
3106 | format_dev_t(buf, cache->metadata_dev->bdev->bd_dev); | |
3107 | DMEMIT("%s ", buf); | |
3108 | format_dev_t(buf, cache->cache_dev->bdev->bd_dev); | |
3109 | DMEMIT("%s ", buf); | |
3110 | format_dev_t(buf, cache->origin_dev->bdev->bd_dev); | |
3111 | DMEMIT("%s", buf); | |
3112 | ||
3113 | for (i = 0; i < cache->nr_ctr_args - 1; i++) | |
3114 | DMEMIT(" %s", cache->ctr_args[i]); | |
3115 | if (cache->nr_ctr_args) | |
3116 | DMEMIT(" %s", cache->ctr_args[cache->nr_ctr_args - 1]); | |
8ec45662 TS |
3117 | break; |
3118 | ||
3119 | case STATUSTYPE_IMA: | |
3120 | DMEMIT_TARGET_NAME_VERSION(ti->type); | |
3121 | if (get_cache_mode(cache) == CM_FAIL) | |
3122 | DMEMIT(",metadata_mode=fail"); | |
3123 | else if (get_cache_mode(cache) == CM_READ_ONLY) | |
3124 | DMEMIT(",metadata_mode=ro"); | |
3125 | else | |
3126 | DMEMIT(",metadata_mode=rw"); | |
3127 | ||
3128 | format_dev_t(buf, cache->metadata_dev->bdev->bd_dev); | |
3129 | DMEMIT(",cache_metadata_device=%s", buf); | |
3130 | format_dev_t(buf, cache->cache_dev->bdev->bd_dev); | |
3131 | DMEMIT(",cache_device=%s", buf); | |
3132 | format_dev_t(buf, cache->origin_dev->bdev->bd_dev); | |
3133 | DMEMIT(",cache_origin_device=%s", buf); | |
3134 | DMEMIT(",writethrough=%c", writethrough_mode(cache) ? 'y' : 'n'); | |
3135 | DMEMIT(",writeback=%c", writeback_mode(cache) ? 'y' : 'n'); | |
3136 | DMEMIT(",passthrough=%c", passthrough_mode(cache) ? 'y' : 'n'); | |
3137 | DMEMIT(",metadata2=%c", cache->features.metadata_version == 2 ? 'y' : 'n'); | |
3138 | DMEMIT(",no_discard_passdown=%c", cache->features.discard_passdown ? 'n' : 'y'); | |
3139 | DMEMIT(";"); | |
3140 | break; | |
c6b4fcba JT |
3141 | } |
3142 | ||
3143 | return; | |
3144 | ||
3145 | err: | |
3146 | DMEMIT("Error"); | |
3147 | } | |
3148 | ||
b29d4986 JT |
3149 | /* |
3150 | * Defines a range of cblocks, begin to (end - 1) are in the range. end is | |
3151 | * the one-past-the-end value. | |
3152 | */ | |
3153 | struct cblock_range { | |
3154 | dm_cblock_t begin; | |
3155 | dm_cblock_t end; | |
3156 | }; | |
3157 | ||
c6b4fcba | 3158 | /* |
65790ff9 JT |
3159 | * A cache block range can take two forms: |
3160 | * | |
3161 | * i) A single cblock, eg. '3456' | |
b29d4986 | 3162 | * ii) A begin and end cblock with a dash between, eg. 123-234 |
65790ff9 JT |
3163 | */ |
3164 | static int parse_cblock_range(struct cache *cache, const char *str, | |
3165 | struct cblock_range *result) | |
3166 | { | |
3167 | char dummy; | |
3168 | uint64_t b, e; | |
3169 | int r; | |
3170 | ||
3171 | /* | |
3172 | * Try and parse form (ii) first. | |
3173 | */ | |
3174 | r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy); | |
3175 | if (r < 0) | |
3176 | return r; | |
3177 | ||
3178 | if (r == 2) { | |
3179 | result->begin = to_cblock(b); | |
3180 | result->end = to_cblock(e); | |
3181 | return 0; | |
3182 | } | |
3183 | ||
3184 | /* | |
3185 | * That didn't work, try form (i). | |
3186 | */ | |
3187 | r = sscanf(str, "%llu%c", &b, &dummy); | |
3188 | if (r < 0) | |
3189 | return r; | |
3190 | ||
3191 | if (r == 1) { | |
3192 | result->begin = to_cblock(b); | |
3193 | result->end = to_cblock(from_cblock(result->begin) + 1u); | |
3194 | return 0; | |
3195 | } | |
3196 | ||
b61d9509 | 3197 | DMERR("%s: invalid cblock range '%s'", cache_device_name(cache), str); |
65790ff9 JT |
3198 | return -EINVAL; |
3199 | } | |
3200 | ||
3201 | static int validate_cblock_range(struct cache *cache, struct cblock_range *range) | |
3202 | { | |
3203 | uint64_t b = from_cblock(range->begin); | |
3204 | uint64_t e = from_cblock(range->end); | |
3205 | uint64_t n = from_cblock(cache->cache_size); | |
3206 | ||
3207 | if (b >= n) { | |
b61d9509 MS |
3208 | DMERR("%s: begin cblock out of range: %llu >= %llu", |
3209 | cache_device_name(cache), b, n); | |
65790ff9 JT |
3210 | return -EINVAL; |
3211 | } | |
3212 | ||
3213 | if (e > n) { | |
b61d9509 MS |
3214 | DMERR("%s: end cblock out of range: %llu > %llu", |
3215 | cache_device_name(cache), e, n); | |
65790ff9 JT |
3216 | return -EINVAL; |
3217 | } | |
3218 | ||
3219 | if (b >= e) { | |
b61d9509 MS |
3220 | DMERR("%s: invalid cblock range: %llu >= %llu", |
3221 | cache_device_name(cache), b, e); | |
65790ff9 JT |
3222 | return -EINVAL; |
3223 | } | |
3224 | ||
3225 | return 0; | |
3226 | } | |
3227 | ||
b29d4986 JT |
3228 | static inline dm_cblock_t cblock_succ(dm_cblock_t b) |
3229 | { | |
3230 | return to_cblock(from_cblock(b) + 1); | |
3231 | } | |
3232 | ||
65790ff9 JT |
3233 | static int request_invalidation(struct cache *cache, struct cblock_range *range) |
3234 | { | |
b29d4986 | 3235 | int r = 0; |
65790ff9 | 3236 | |
b29d4986 JT |
3237 | /* |
3238 | * We don't need to do any locking here because we know we're in | |
3239 | * passthrough mode. There's is potential for a race between an | |
3240 | * invalidation triggered by an io and an invalidation message. This | |
3241 | * is harmless, we must not worry if the policy call fails. | |
3242 | */ | |
3243 | while (range->begin != range->end) { | |
3244 | r = invalidate_cblock(cache, range->begin); | |
3245 | if (r) | |
3246 | return r; | |
65790ff9 | 3247 | |
b29d4986 JT |
3248 | range->begin = cblock_succ(range->begin); |
3249 | } | |
65790ff9 | 3250 | |
b29d4986 JT |
3251 | cache->commit_requested = true; |
3252 | return r; | |
65790ff9 JT |
3253 | } |
3254 | ||
3255 | static int process_invalidate_cblocks_message(struct cache *cache, unsigned count, | |
3256 | const char **cblock_ranges) | |
3257 | { | |
3258 | int r = 0; | |
3259 | unsigned i; | |
3260 | struct cblock_range range; | |
3261 | ||
8e3c3827 | 3262 | if (!passthrough_mode(cache)) { |
b61d9509 MS |
3263 | DMERR("%s: cache has to be in passthrough mode for invalidation", |
3264 | cache_device_name(cache)); | |
65790ff9 JT |
3265 | return -EPERM; |
3266 | } | |
3267 | ||
3268 | for (i = 0; i < count; i++) { | |
3269 | r = parse_cblock_range(cache, cblock_ranges[i], &range); | |
3270 | if (r) | |
3271 | break; | |
3272 | ||
3273 | r = validate_cblock_range(cache, &range); | |
3274 | if (r) | |
3275 | break; | |
3276 | ||
3277 | /* | |
3278 | * Pass begin and end origin blocks to the worker and wake it. | |
3279 | */ | |
3280 | r = request_invalidation(cache, &range); | |
3281 | if (r) | |
3282 | break; | |
3283 | } | |
3284 | ||
3285 | return r; | |
3286 | } | |
3287 | ||
3288 | /* | |
3289 | * Supports | |
3290 | * "<key> <value>" | |
3291 | * and | |
3292 | * "invalidate_cblocks [(<begin>)|(<begin>-<end>)]* | |
c6b4fcba JT |
3293 | * |
3294 | * The key migration_threshold is supported by the cache target core. | |
3295 | */ | |
1eb5fa84 MS |
3296 | static int cache_message(struct dm_target *ti, unsigned argc, char **argv, |
3297 | char *result, unsigned maxlen) | |
c6b4fcba | 3298 | { |
c6b4fcba JT |
3299 | struct cache *cache = ti->private; |
3300 | ||
65790ff9 JT |
3301 | if (!argc) |
3302 | return -EINVAL; | |
3303 | ||
028ae9f7 | 3304 | if (get_cache_mode(cache) >= CM_READ_ONLY) { |
b61d9509 MS |
3305 | DMERR("%s: unable to service cache target messages in READ_ONLY or FAIL mode", |
3306 | cache_device_name(cache)); | |
028ae9f7 JT |
3307 | return -EOPNOTSUPP; |
3308 | } | |
3309 | ||
7b6b2bc9 | 3310 | if (!strcasecmp(argv[0], "invalidate_cblocks")) |
65790ff9 JT |
3311 | return process_invalidate_cblocks_message(cache, argc - 1, (const char **) argv + 1); |
3312 | ||
c6b4fcba JT |
3313 | if (argc != 2) |
3314 | return -EINVAL; | |
3315 | ||
2f14f4b5 | 3316 | return set_config_value(cache, argv[0], argv[1]); |
c6b4fcba JT |
3317 | } |
3318 | ||
3319 | static int cache_iterate_devices(struct dm_target *ti, | |
3320 | iterate_devices_callout_fn fn, void *data) | |
3321 | { | |
3322 | int r = 0; | |
3323 | struct cache *cache = ti->private; | |
3324 | ||
3325 | r = fn(ti, cache->cache_dev, 0, get_dev_size(cache->cache_dev), data); | |
3326 | if (!r) | |
3327 | r = fn(ti, cache->origin_dev, 0, ti->len, data); | |
3328 | ||
3329 | return r; | |
3330 | } | |
3331 | ||
de7180ff MS |
3332 | /* |
3333 | * If discard_passdown was enabled verify that the origin device | |
3334 | * supports discards. Disable discard_passdown if not. | |
3335 | */ | |
3336 | static void disable_passdown_if_not_supported(struct cache *cache) | |
3337 | { | |
3338 | struct block_device *origin_bdev = cache->origin_dev->bdev; | |
3339 | struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits; | |
3340 | const char *reason = NULL; | |
de7180ff MS |
3341 | |
3342 | if (!cache->features.discard_passdown) | |
3343 | return; | |
3344 | ||
70200574 | 3345 | if (!bdev_max_discard_sectors(origin_bdev)) |
de7180ff MS |
3346 | reason = "discard unsupported"; |
3347 | ||
3348 | else if (origin_limits->max_discard_sectors < cache->sectors_per_block) | |
3349 | reason = "max discard sectors smaller than a block"; | |
3350 | ||
3351 | if (reason) { | |
385411ff CH |
3352 | DMWARN("Origin device (%pg) %s: Disabling discard passdown.", |
3353 | origin_bdev, reason); | |
de7180ff MS |
3354 | cache->features.discard_passdown = false; |
3355 | } | |
3356 | } | |
3357 | ||
c6b4fcba JT |
3358 | static void set_discard_limits(struct cache *cache, struct queue_limits *limits) |
3359 | { | |
de7180ff MS |
3360 | struct block_device *origin_bdev = cache->origin_dev->bdev; |
3361 | struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits; | |
3362 | ||
3363 | if (!cache->features.discard_passdown) { | |
3364 | /* No passdown is done so setting own virtual limits */ | |
3365 | limits->max_discard_sectors = min_t(sector_t, cache->discard_block_size * 1024, | |
3366 | cache->origin_sectors); | |
3367 | limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT; | |
3368 | return; | |
3369 | } | |
3370 | ||
c6b4fcba | 3371 | /* |
de7180ff MS |
3372 | * cache_iterate_devices() is stacking both origin and fast device limits |
3373 | * but discards aren't passed to fast device, so inherit origin's limits. | |
c6b4fcba | 3374 | */ |
de7180ff MS |
3375 | limits->max_discard_sectors = origin_limits->max_discard_sectors; |
3376 | limits->max_hw_discard_sectors = origin_limits->max_hw_discard_sectors; | |
3377 | limits->discard_granularity = origin_limits->discard_granularity; | |
3378 | limits->discard_alignment = origin_limits->discard_alignment; | |
3379 | limits->discard_misaligned = origin_limits->discard_misaligned; | |
c6b4fcba JT |
3380 | } |
3381 | ||
3382 | static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
3383 | { | |
3384 | struct cache *cache = ti->private; | |
f6109372 | 3385 | uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; |
c6b4fcba | 3386 | |
f6109372 MS |
3387 | /* |
3388 | * If the system-determined stacked limits are compatible with the | |
3389 | * cache's blocksize (io_opt is a factor) do not override them. | |
3390 | */ | |
3391 | if (io_opt_sectors < cache->sectors_per_block || | |
3392 | do_div(io_opt_sectors, cache->sectors_per_block)) { | |
b0246530 | 3393 | blk_limits_io_min(limits, cache->sectors_per_block << SECTOR_SHIFT); |
f6109372 MS |
3394 | blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT); |
3395 | } | |
de7180ff MS |
3396 | |
3397 | disable_passdown_if_not_supported(cache); | |
c6b4fcba JT |
3398 | set_discard_limits(cache, limits); |
3399 | } | |
3400 | ||
3401 | /*----------------------------------------------------------------*/ | |
3402 | ||
3403 | static struct target_type cache_target = { | |
3404 | .name = "cache", | |
636be424 | 3405 | .version = {2, 2, 0}, |
c6b4fcba JT |
3406 | .module = THIS_MODULE, |
3407 | .ctr = cache_ctr, | |
3408 | .dtr = cache_dtr, | |
3409 | .map = cache_map, | |
3410 | .end_io = cache_end_io, | |
3411 | .postsuspend = cache_postsuspend, | |
3412 | .preresume = cache_preresume, | |
3413 | .resume = cache_resume, | |
3414 | .status = cache_status, | |
3415 | .message = cache_message, | |
3416 | .iterate_devices = cache_iterate_devices, | |
c6b4fcba JT |
3417 | .io_hints = cache_io_hints, |
3418 | }; | |
3419 | ||
3420 | static int __init dm_cache_init(void) | |
3421 | { | |
3422 | int r; | |
3423 | ||
c6b4fcba | 3424 | migration_cache = KMEM_CACHE(dm_cache_migration, 0); |
c7cd5550 | 3425 | if (!migration_cache) |
c6b4fcba | 3426 | return -ENOMEM; |
c6b4fcba | 3427 | |
7e6358d2 | 3428 | r = dm_register_target(&cache_target); |
3429 | if (r) { | |
3430 | DMERR("cache target registration failed: %d", r); | |
c7cd5550 | 3431 | kmem_cache_destroy(migration_cache); |
7e6358d2 | 3432 | return r; |
3433 | } | |
3434 | ||
c6b4fcba JT |
3435 | return 0; |
3436 | } | |
3437 | ||
3438 | static void __exit dm_cache_exit(void) | |
3439 | { | |
3440 | dm_unregister_target(&cache_target); | |
3441 | kmem_cache_destroy(migration_cache); | |
3442 | } | |
3443 | ||
3444 | module_init(dm_cache_init); | |
3445 | module_exit(dm_cache_exit); | |
3446 | ||
3447 | MODULE_DESCRIPTION(DM_NAME " cache target"); | |
3448 | MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); | |
3449 | MODULE_LICENSE("GPL"); |