Commit | Line | Data |
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c6b4fcba JT |
1 | /* |
2 | * Copyright (C) 2012 Red Hat. All rights reserved. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7 | #include "dm.h" | |
8 | #include "dm-bio-prison.h" | |
b844fe69 | 9 | #include "dm-bio-record.h" |
c6b4fcba JT |
10 | #include "dm-cache-metadata.h" |
11 | ||
12 | #include <linux/dm-io.h> | |
13 | #include <linux/dm-kcopyd.h> | |
0f30af98 | 14 | #include <linux/jiffies.h> |
c6b4fcba JT |
15 | #include <linux/init.h> |
16 | #include <linux/mempool.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/vmalloc.h> | |
20 | ||
21 | #define DM_MSG_PREFIX "cache" | |
22 | ||
23 | DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(cache_copy_throttle, | |
24 | "A percentage of time allocated for copying to and/or from cache"); | |
25 | ||
26 | /*----------------------------------------------------------------*/ | |
27 | ||
77289d32 JT |
28 | #define IOT_RESOLUTION 4 |
29 | ||
30 | struct io_tracker { | |
31 | spinlock_t lock; | |
32 | ||
33 | /* | |
34 | * Sectors of in-flight IO. | |
35 | */ | |
36 | sector_t in_flight; | |
37 | ||
38 | /* | |
39 | * The time, in jiffies, when this device became idle (if it is | |
40 | * indeed idle). | |
41 | */ | |
42 | unsigned long idle_time; | |
43 | unsigned long last_update_time; | |
44 | }; | |
45 | ||
46 | static void iot_init(struct io_tracker *iot) | |
47 | { | |
48 | spin_lock_init(&iot->lock); | |
49 | iot->in_flight = 0ul; | |
50 | iot->idle_time = 0ul; | |
51 | iot->last_update_time = jiffies; | |
52 | } | |
53 | ||
54 | static bool __iot_idle_for(struct io_tracker *iot, unsigned long jifs) | |
55 | { | |
56 | if (iot->in_flight) | |
57 | return false; | |
58 | ||
59 | return time_after(jiffies, iot->idle_time + jifs); | |
60 | } | |
61 | ||
62 | static bool iot_idle_for(struct io_tracker *iot, unsigned long jifs) | |
63 | { | |
64 | bool r; | |
65 | unsigned long flags; | |
66 | ||
67 | spin_lock_irqsave(&iot->lock, flags); | |
68 | r = __iot_idle_for(iot, jifs); | |
69 | spin_unlock_irqrestore(&iot->lock, flags); | |
70 | ||
71 | return r; | |
72 | } | |
73 | ||
74 | static void iot_io_begin(struct io_tracker *iot, sector_t len) | |
75 | { | |
76 | unsigned long flags; | |
77 | ||
78 | spin_lock_irqsave(&iot->lock, flags); | |
79 | iot->in_flight += len; | |
80 | spin_unlock_irqrestore(&iot->lock, flags); | |
81 | } | |
82 | ||
83 | static void __iot_io_end(struct io_tracker *iot, sector_t len) | |
84 | { | |
85 | iot->in_flight -= len; | |
86 | if (!iot->in_flight) | |
87 | iot->idle_time = jiffies; | |
88 | } | |
89 | ||
90 | static void iot_io_end(struct io_tracker *iot, sector_t len) | |
91 | { | |
92 | unsigned long flags; | |
93 | ||
94 | spin_lock_irqsave(&iot->lock, flags); | |
95 | __iot_io_end(iot, len); | |
96 | spin_unlock_irqrestore(&iot->lock, flags); | |
97 | } | |
98 | ||
99 | /*----------------------------------------------------------------*/ | |
100 | ||
c6b4fcba JT |
101 | /* |
102 | * Glossary: | |
103 | * | |
104 | * oblock: index of an origin block | |
105 | * cblock: index of a cache block | |
106 | * promotion: movement of a block from origin to cache | |
107 | * demotion: movement of a block from cache to origin | |
108 | * migration: movement of a block between the origin and cache device, | |
109 | * either direction | |
110 | */ | |
111 | ||
112 | /*----------------------------------------------------------------*/ | |
113 | ||
c9d28d5d JT |
114 | /* |
115 | * There are a couple of places where we let a bio run, but want to do some | |
116 | * work before calling its endio function. We do this by temporarily | |
117 | * changing the endio fn. | |
118 | */ | |
119 | struct dm_hook_info { | |
120 | bio_end_io_t *bi_end_io; | |
c9d28d5d JT |
121 | }; |
122 | ||
123 | static void dm_hook_bio(struct dm_hook_info *h, struct bio *bio, | |
124 | bio_end_io_t *bi_end_io, void *bi_private) | |
125 | { | |
126 | h->bi_end_io = bio->bi_end_io; | |
c9d28d5d JT |
127 | |
128 | bio->bi_end_io = bi_end_io; | |
129 | bio->bi_private = bi_private; | |
130 | } | |
131 | ||
132 | static void dm_unhook_bio(struct dm_hook_info *h, struct bio *bio) | |
133 | { | |
134 | bio->bi_end_io = h->bi_end_io; | |
c9d28d5d JT |
135 | } |
136 | ||
137 | /*----------------------------------------------------------------*/ | |
138 | ||
c6b4fcba JT |
139 | #define MIGRATION_POOL_SIZE 128 |
140 | #define COMMIT_PERIOD HZ | |
141 | #define MIGRATION_COUNT_WINDOW 10 | |
142 | ||
143 | /* | |
05473044 MS |
144 | * The block size of the device holding cache data must be |
145 | * between 32KB and 1GB. | |
c6b4fcba JT |
146 | */ |
147 | #define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (32 * 1024 >> SECTOR_SHIFT) | |
05473044 | 148 | #define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT) |
c6b4fcba | 149 | |
2ee57d58 | 150 | enum cache_metadata_mode { |
c6b4fcba JT |
151 | CM_WRITE, /* metadata may be changed */ |
152 | CM_READ_ONLY, /* metadata may not be changed */ | |
028ae9f7 | 153 | CM_FAIL |
c6b4fcba JT |
154 | }; |
155 | ||
2ee57d58 JT |
156 | enum cache_io_mode { |
157 | /* | |
158 | * Data is written to cached blocks only. These blocks are marked | |
159 | * dirty. If you lose the cache device you will lose data. | |
160 | * Potential performance increase for both reads and writes. | |
161 | */ | |
162 | CM_IO_WRITEBACK, | |
163 | ||
164 | /* | |
165 | * Data is written to both cache and origin. Blocks are never | |
166 | * dirty. Potential performance benfit for reads only. | |
167 | */ | |
168 | CM_IO_WRITETHROUGH, | |
169 | ||
170 | /* | |
171 | * A degraded mode useful for various cache coherency situations | |
172 | * (eg, rolling back snapshots). Reads and writes always go to the | |
173 | * origin. If a write goes to a cached oblock, then the cache | |
174 | * block is invalidated. | |
175 | */ | |
176 | CM_IO_PASSTHROUGH | |
177 | }; | |
178 | ||
c6b4fcba | 179 | struct cache_features { |
2ee57d58 JT |
180 | enum cache_metadata_mode mode; |
181 | enum cache_io_mode io_mode; | |
c6b4fcba JT |
182 | }; |
183 | ||
184 | struct cache_stats { | |
185 | atomic_t read_hit; | |
186 | atomic_t read_miss; | |
187 | atomic_t write_hit; | |
188 | atomic_t write_miss; | |
189 | atomic_t demotion; | |
190 | atomic_t promotion; | |
191 | atomic_t copies_avoided; | |
192 | atomic_t cache_cell_clash; | |
193 | atomic_t commit_count; | |
194 | atomic_t discard_count; | |
195 | }; | |
196 | ||
65790ff9 JT |
197 | /* |
198 | * Defines a range of cblocks, begin to (end - 1) are in the range. end is | |
199 | * the one-past-the-end value. | |
200 | */ | |
201 | struct cblock_range { | |
202 | dm_cblock_t begin; | |
203 | dm_cblock_t end; | |
204 | }; | |
205 | ||
206 | struct invalidation_request { | |
207 | struct list_head list; | |
208 | struct cblock_range *cblocks; | |
209 | ||
210 | atomic_t complete; | |
211 | int err; | |
212 | ||
213 | wait_queue_head_t result_wait; | |
214 | }; | |
215 | ||
c6b4fcba JT |
216 | struct cache { |
217 | struct dm_target *ti; | |
218 | struct dm_target_callbacks callbacks; | |
219 | ||
c9ec5d7c MS |
220 | struct dm_cache_metadata *cmd; |
221 | ||
c6b4fcba JT |
222 | /* |
223 | * Metadata is written to this device. | |
224 | */ | |
225 | struct dm_dev *metadata_dev; | |
226 | ||
227 | /* | |
228 | * The slower of the two data devices. Typically a spindle. | |
229 | */ | |
230 | struct dm_dev *origin_dev; | |
231 | ||
232 | /* | |
233 | * The faster of the two data devices. Typically an SSD. | |
234 | */ | |
235 | struct dm_dev *cache_dev; | |
236 | ||
c6b4fcba JT |
237 | /* |
238 | * Size of the origin device in _complete_ blocks and native sectors. | |
239 | */ | |
240 | dm_oblock_t origin_blocks; | |
241 | sector_t origin_sectors; | |
242 | ||
243 | /* | |
244 | * Size of the cache device in blocks. | |
245 | */ | |
246 | dm_cblock_t cache_size; | |
247 | ||
248 | /* | |
249 | * Fields for converting from sectors to blocks. | |
250 | */ | |
251 | uint32_t sectors_per_block; | |
252 | int sectors_per_block_shift; | |
253 | ||
c6b4fcba | 254 | spinlock_t lock; |
651f5fa2 | 255 | struct list_head deferred_cells; |
c6b4fcba JT |
256 | struct bio_list deferred_bios; |
257 | struct bio_list deferred_flush_bios; | |
e2e74d61 | 258 | struct bio_list deferred_writethrough_bios; |
c6b4fcba JT |
259 | struct list_head quiesced_migrations; |
260 | struct list_head completed_migrations; | |
261 | struct list_head need_commit_migrations; | |
262 | sector_t migration_threshold; | |
c6b4fcba | 263 | wait_queue_head_t migration_wait; |
a59db676 JT |
264 | atomic_t nr_allocated_migrations; |
265 | ||
266 | /* | |
267 | * The number of in flight migrations that are performing | |
268 | * background io. eg, promotion, writeback. | |
269 | */ | |
270 | atomic_t nr_io_migrations; | |
c6b4fcba | 271 | |
66cb1910 | 272 | wait_queue_head_t quiescing_wait; |
238f8363 | 273 | atomic_t quiescing; |
66cb1910 JT |
274 | atomic_t quiescing_ack; |
275 | ||
c6b4fcba JT |
276 | /* |
277 | * cache_size entries, dirty if set | |
278 | */ | |
44fa816b | 279 | atomic_t nr_dirty; |
c6b4fcba JT |
280 | unsigned long *dirty_bitset; |
281 | ||
282 | /* | |
283 | * origin_blocks entries, discarded if set. | |
284 | */ | |
1bad9bc4 | 285 | dm_dblock_t discard_nr_blocks; |
c6b4fcba | 286 | unsigned long *discard_bitset; |
08b18451 | 287 | uint32_t discard_block_size; /* a power of 2 times sectors per block */ |
c9ec5d7c MS |
288 | |
289 | /* | |
290 | * Rather than reconstructing the table line for the status we just | |
291 | * save it and regurgitate. | |
292 | */ | |
293 | unsigned nr_ctr_args; | |
294 | const char **ctr_args; | |
c6b4fcba JT |
295 | |
296 | struct dm_kcopyd_client *copier; | |
297 | struct workqueue_struct *wq; | |
298 | struct work_struct worker; | |
299 | ||
300 | struct delayed_work waker; | |
301 | unsigned long last_commit_jiffies; | |
302 | ||
303 | struct dm_bio_prison *prison; | |
304 | struct dm_deferred_set *all_io_ds; | |
305 | ||
306 | mempool_t *migration_pool; | |
c6b4fcba JT |
307 | |
308 | struct dm_cache_policy *policy; | |
309 | unsigned policy_nr_args; | |
310 | ||
311 | bool need_tick_bio:1; | |
312 | bool sized:1; | |
65790ff9 | 313 | bool invalidate:1; |
c6b4fcba JT |
314 | bool commit_requested:1; |
315 | bool loaded_mappings:1; | |
316 | bool loaded_discards:1; | |
317 | ||
c6b4fcba | 318 | /* |
c9ec5d7c | 319 | * Cache features such as write-through. |
c6b4fcba | 320 | */ |
c9ec5d7c MS |
321 | struct cache_features features; |
322 | ||
323 | struct cache_stats stats; | |
65790ff9 JT |
324 | |
325 | /* | |
326 | * Invalidation fields. | |
327 | */ | |
328 | spinlock_t invalidation_lock; | |
329 | struct list_head invalidation_requests; | |
066dbaa3 JT |
330 | |
331 | struct io_tracker origin_tracker; | |
c6b4fcba JT |
332 | }; |
333 | ||
334 | struct per_bio_data { | |
335 | bool tick:1; | |
336 | unsigned req_nr:2; | |
337 | struct dm_deferred_entry *all_io_entry; | |
c6eda5e8 | 338 | struct dm_hook_info hook_info; |
066dbaa3 | 339 | sector_t len; |
e2e74d61 | 340 | |
19b0092e MS |
341 | /* |
342 | * writethrough fields. These MUST remain at the end of this | |
343 | * structure and the 'cache' member must be the first as it | |
aeed1420 | 344 | * is used to determine the offset of the writethrough fields. |
19b0092e | 345 | */ |
e2e74d61 JT |
346 | struct cache *cache; |
347 | dm_cblock_t cblock; | |
b844fe69 | 348 | struct dm_bio_details bio_details; |
c6b4fcba JT |
349 | }; |
350 | ||
351 | struct dm_cache_migration { | |
352 | struct list_head list; | |
353 | struct cache *cache; | |
354 | ||
355 | unsigned long start_jiffies; | |
356 | dm_oblock_t old_oblock; | |
357 | dm_oblock_t new_oblock; | |
358 | dm_cblock_t cblock; | |
359 | ||
360 | bool err:1; | |
7ae34e77 | 361 | bool discard:1; |
c6b4fcba JT |
362 | bool writeback:1; |
363 | bool demote:1; | |
364 | bool promote:1; | |
c9d28d5d | 365 | bool requeue_holder:1; |
65790ff9 | 366 | bool invalidate:1; |
c6b4fcba JT |
367 | |
368 | struct dm_bio_prison_cell *old_ocell; | |
369 | struct dm_bio_prison_cell *new_ocell; | |
370 | }; | |
371 | ||
372 | /* | |
373 | * Processing a bio in the worker thread may require these memory | |
374 | * allocations. We prealloc to avoid deadlocks (the same worker thread | |
375 | * frees them back to the mempool). | |
376 | */ | |
377 | struct prealloc { | |
378 | struct dm_cache_migration *mg; | |
379 | struct dm_bio_prison_cell *cell1; | |
380 | struct dm_bio_prison_cell *cell2; | |
381 | }; | |
382 | ||
028ae9f7 JT |
383 | static enum cache_metadata_mode get_cache_mode(struct cache *cache); |
384 | ||
c6b4fcba JT |
385 | static void wake_worker(struct cache *cache) |
386 | { | |
387 | queue_work(cache->wq, &cache->worker); | |
388 | } | |
389 | ||
390 | /*----------------------------------------------------------------*/ | |
391 | ||
392 | static struct dm_bio_prison_cell *alloc_prison_cell(struct cache *cache) | |
393 | { | |
394 | /* FIXME: change to use a local slab. */ | |
395 | return dm_bio_prison_alloc_cell(cache->prison, GFP_NOWAIT); | |
396 | } | |
397 | ||
398 | static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell *cell) | |
399 | { | |
400 | dm_bio_prison_free_cell(cache->prison, cell); | |
401 | } | |
402 | ||
a59db676 JT |
403 | static struct dm_cache_migration *alloc_migration(struct cache *cache) |
404 | { | |
405 | struct dm_cache_migration *mg; | |
406 | ||
407 | mg = mempool_alloc(cache->migration_pool, GFP_NOWAIT); | |
408 | if (mg) { | |
409 | mg->cache = cache; | |
410 | atomic_inc(&mg->cache->nr_allocated_migrations); | |
411 | } | |
412 | ||
413 | return mg; | |
414 | } | |
415 | ||
416 | static void free_migration(struct dm_cache_migration *mg) | |
417 | { | |
88bf5184 | 418 | struct cache *cache = mg->cache; |
a59db676 | 419 | |
88bf5184 JT |
420 | if (atomic_dec_and_test(&cache->nr_allocated_migrations)) |
421 | wake_up(&cache->migration_wait); | |
422 | ||
423 | mempool_free(mg, cache->migration_pool); | |
a59db676 JT |
424 | } |
425 | ||
c6b4fcba JT |
426 | static int prealloc_data_structs(struct cache *cache, struct prealloc *p) |
427 | { | |
428 | if (!p->mg) { | |
a59db676 | 429 | p->mg = alloc_migration(cache); |
c6b4fcba JT |
430 | if (!p->mg) |
431 | return -ENOMEM; | |
432 | } | |
433 | ||
434 | if (!p->cell1) { | |
435 | p->cell1 = alloc_prison_cell(cache); | |
436 | if (!p->cell1) | |
437 | return -ENOMEM; | |
438 | } | |
439 | ||
440 | if (!p->cell2) { | |
441 | p->cell2 = alloc_prison_cell(cache); | |
442 | if (!p->cell2) | |
443 | return -ENOMEM; | |
444 | } | |
445 | ||
446 | return 0; | |
447 | } | |
448 | ||
449 | static void prealloc_free_structs(struct cache *cache, struct prealloc *p) | |
450 | { | |
451 | if (p->cell2) | |
452 | free_prison_cell(cache, p->cell2); | |
453 | ||
454 | if (p->cell1) | |
455 | free_prison_cell(cache, p->cell1); | |
456 | ||
457 | if (p->mg) | |
a59db676 | 458 | free_migration(p->mg); |
c6b4fcba JT |
459 | } |
460 | ||
461 | static struct dm_cache_migration *prealloc_get_migration(struct prealloc *p) | |
462 | { | |
463 | struct dm_cache_migration *mg = p->mg; | |
464 | ||
465 | BUG_ON(!mg); | |
466 | p->mg = NULL; | |
467 | ||
468 | return mg; | |
469 | } | |
470 | ||
471 | /* | |
472 | * You must have a cell within the prealloc struct to return. If not this | |
473 | * function will BUG() rather than returning NULL. | |
474 | */ | |
475 | static struct dm_bio_prison_cell *prealloc_get_cell(struct prealloc *p) | |
476 | { | |
477 | struct dm_bio_prison_cell *r = NULL; | |
478 | ||
479 | if (p->cell1) { | |
480 | r = p->cell1; | |
481 | p->cell1 = NULL; | |
482 | ||
483 | } else if (p->cell2) { | |
484 | r = p->cell2; | |
485 | p->cell2 = NULL; | |
486 | } else | |
487 | BUG(); | |
488 | ||
489 | return r; | |
490 | } | |
491 | ||
492 | /* | |
493 | * You can't have more than two cells in a prealloc struct. BUG() will be | |
494 | * called if you try and overfill. | |
495 | */ | |
496 | static void prealloc_put_cell(struct prealloc *p, struct dm_bio_prison_cell *cell) | |
497 | { | |
498 | if (!p->cell2) | |
499 | p->cell2 = cell; | |
500 | ||
501 | else if (!p->cell1) | |
502 | p->cell1 = cell; | |
503 | ||
504 | else | |
505 | BUG(); | |
506 | } | |
507 | ||
508 | /*----------------------------------------------------------------*/ | |
509 | ||
7ae34e77 | 510 | static void build_key(dm_oblock_t begin, dm_oblock_t end, struct dm_cell_key *key) |
c6b4fcba JT |
511 | { |
512 | key->virtual = 0; | |
513 | key->dev = 0; | |
7ae34e77 JT |
514 | key->block_begin = from_oblock(begin); |
515 | key->block_end = from_oblock(end); | |
c6b4fcba JT |
516 | } |
517 | ||
518 | /* | |
519 | * The caller hands in a preallocated cell, and a free function for it. | |
520 | * The cell will be freed if there's an error, or if it wasn't used because | |
521 | * a cell with that key already exists. | |
522 | */ | |
523 | typedef void (*cell_free_fn)(void *context, struct dm_bio_prison_cell *cell); | |
524 | ||
7ae34e77 JT |
525 | static int bio_detain_range(struct cache *cache, dm_oblock_t oblock_begin, dm_oblock_t oblock_end, |
526 | struct bio *bio, struct dm_bio_prison_cell *cell_prealloc, | |
527 | cell_free_fn free_fn, void *free_context, | |
528 | struct dm_bio_prison_cell **cell_result) | |
c6b4fcba JT |
529 | { |
530 | int r; | |
531 | struct dm_cell_key key; | |
532 | ||
7ae34e77 | 533 | build_key(oblock_begin, oblock_end, &key); |
c6b4fcba JT |
534 | r = dm_bio_detain(cache->prison, &key, bio, cell_prealloc, cell_result); |
535 | if (r) | |
536 | free_fn(free_context, cell_prealloc); | |
537 | ||
538 | return r; | |
539 | } | |
540 | ||
7ae34e77 JT |
541 | static int bio_detain(struct cache *cache, dm_oblock_t oblock, |
542 | struct bio *bio, struct dm_bio_prison_cell *cell_prealloc, | |
543 | cell_free_fn free_fn, void *free_context, | |
544 | struct dm_bio_prison_cell **cell_result) | |
545 | { | |
546 | dm_oblock_t end = to_oblock(from_oblock(oblock) + 1ULL); | |
547 | return bio_detain_range(cache, oblock, end, bio, | |
548 | cell_prealloc, free_fn, free_context, cell_result); | |
549 | } | |
550 | ||
c6b4fcba JT |
551 | static int get_cell(struct cache *cache, |
552 | dm_oblock_t oblock, | |
553 | struct prealloc *structs, | |
554 | struct dm_bio_prison_cell **cell_result) | |
555 | { | |
556 | int r; | |
557 | struct dm_cell_key key; | |
558 | struct dm_bio_prison_cell *cell_prealloc; | |
559 | ||
560 | cell_prealloc = prealloc_get_cell(structs); | |
561 | ||
7ae34e77 | 562 | build_key(oblock, to_oblock(from_oblock(oblock) + 1ULL), &key); |
c6b4fcba JT |
563 | r = dm_get_cell(cache->prison, &key, cell_prealloc, cell_result); |
564 | if (r) | |
565 | prealloc_put_cell(structs, cell_prealloc); | |
566 | ||
567 | return r; | |
568 | } | |
569 | ||
aeed1420 | 570 | /*----------------------------------------------------------------*/ |
c6b4fcba JT |
571 | |
572 | static bool is_dirty(struct cache *cache, dm_cblock_t b) | |
573 | { | |
574 | return test_bit(from_cblock(b), cache->dirty_bitset); | |
575 | } | |
576 | ||
577 | static void set_dirty(struct cache *cache, dm_oblock_t oblock, dm_cblock_t cblock) | |
578 | { | |
579 | if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
44fa816b | 580 | atomic_inc(&cache->nr_dirty); |
c6b4fcba JT |
581 | policy_set_dirty(cache->policy, oblock); |
582 | } | |
583 | } | |
584 | ||
585 | static void clear_dirty(struct cache *cache, dm_oblock_t oblock, dm_cblock_t cblock) | |
586 | { | |
587 | if (test_and_clear_bit(from_cblock(cblock), cache->dirty_bitset)) { | |
588 | policy_clear_dirty(cache->policy, oblock); | |
44fa816b | 589 | if (atomic_dec_return(&cache->nr_dirty) == 0) |
c6b4fcba JT |
590 | dm_table_event(cache->ti->table); |
591 | } | |
592 | } | |
593 | ||
594 | /*----------------------------------------------------------------*/ | |
aeed1420 | 595 | |
c6b4fcba JT |
596 | static bool block_size_is_power_of_two(struct cache *cache) |
597 | { | |
598 | return cache->sectors_per_block_shift >= 0; | |
599 | } | |
600 | ||
43aeaa29 MP |
601 | /* gcc on ARM generates spurious references to __udivdi3 and __umoddi3 */ |
602 | #if defined(CONFIG_ARM) && __GNUC__ == 4 && __GNUC_MINOR__ <= 6 | |
603 | __always_inline | |
604 | #endif | |
414dd67d JT |
605 | static dm_block_t block_div(dm_block_t b, uint32_t n) |
606 | { | |
607 | do_div(b, n); | |
608 | ||
609 | return b; | |
610 | } | |
611 | ||
7ae34e77 | 612 | static dm_block_t oblocks_per_dblock(struct cache *cache) |
1bad9bc4 | 613 | { |
7ae34e77 | 614 | dm_block_t oblocks = cache->discard_block_size; |
1bad9bc4 | 615 | |
7ae34e77 JT |
616 | if (block_size_is_power_of_two(cache)) |
617 | oblocks >>= cache->sectors_per_block_shift; | |
1bad9bc4 | 618 | else |
7ae34e77 | 619 | oblocks = block_div(oblocks, cache->sectors_per_block); |
1bad9bc4 | 620 | |
7ae34e77 JT |
621 | return oblocks; |
622 | } | |
623 | ||
624 | static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock) | |
625 | { | |
626 | return to_dblock(block_div(from_oblock(oblock), | |
627 | oblocks_per_dblock(cache))); | |
628 | } | |
1bad9bc4 | 629 | |
7ae34e77 JT |
630 | static dm_oblock_t dblock_to_oblock(struct cache *cache, dm_dblock_t dblock) |
631 | { | |
632 | return to_oblock(from_dblock(dblock) * oblocks_per_dblock(cache)); | |
1bad9bc4 JT |
633 | } |
634 | ||
635 | static void set_discard(struct cache *cache, dm_dblock_t b) | |
c6b4fcba JT |
636 | { |
637 | unsigned long flags; | |
638 | ||
7ae34e77 | 639 | BUG_ON(from_dblock(b) >= from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
640 | atomic_inc(&cache->stats.discard_count); |
641 | ||
642 | spin_lock_irqsave(&cache->lock, flags); | |
1bad9bc4 | 643 | set_bit(from_dblock(b), cache->discard_bitset); |
c6b4fcba JT |
644 | spin_unlock_irqrestore(&cache->lock, flags); |
645 | } | |
646 | ||
1bad9bc4 | 647 | static void clear_discard(struct cache *cache, dm_dblock_t b) |
c6b4fcba JT |
648 | { |
649 | unsigned long flags; | |
650 | ||
651 | spin_lock_irqsave(&cache->lock, flags); | |
1bad9bc4 | 652 | clear_bit(from_dblock(b), cache->discard_bitset); |
c6b4fcba JT |
653 | spin_unlock_irqrestore(&cache->lock, flags); |
654 | } | |
655 | ||
1bad9bc4 | 656 | static bool is_discarded(struct cache *cache, dm_dblock_t b) |
c6b4fcba JT |
657 | { |
658 | int r; | |
659 | unsigned long flags; | |
660 | ||
661 | spin_lock_irqsave(&cache->lock, flags); | |
1bad9bc4 | 662 | r = test_bit(from_dblock(b), cache->discard_bitset); |
c6b4fcba JT |
663 | spin_unlock_irqrestore(&cache->lock, flags); |
664 | ||
665 | return r; | |
666 | } | |
667 | ||
668 | static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b) | |
669 | { | |
670 | int r; | |
671 | unsigned long flags; | |
672 | ||
673 | spin_lock_irqsave(&cache->lock, flags); | |
1bad9bc4 JT |
674 | r = test_bit(from_dblock(oblock_to_dblock(cache, b)), |
675 | cache->discard_bitset); | |
c6b4fcba JT |
676 | spin_unlock_irqrestore(&cache->lock, flags); |
677 | ||
678 | return r; | |
679 | } | |
680 | ||
681 | /*----------------------------------------------------------------*/ | |
682 | ||
683 | static void load_stats(struct cache *cache) | |
684 | { | |
685 | struct dm_cache_statistics stats; | |
686 | ||
687 | dm_cache_metadata_get_stats(cache->cmd, &stats); | |
688 | atomic_set(&cache->stats.read_hit, stats.read_hits); | |
689 | atomic_set(&cache->stats.read_miss, stats.read_misses); | |
690 | atomic_set(&cache->stats.write_hit, stats.write_hits); | |
691 | atomic_set(&cache->stats.write_miss, stats.write_misses); | |
692 | } | |
693 | ||
694 | static void save_stats(struct cache *cache) | |
695 | { | |
696 | struct dm_cache_statistics stats; | |
697 | ||
028ae9f7 JT |
698 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
699 | return; | |
700 | ||
c6b4fcba JT |
701 | stats.read_hits = atomic_read(&cache->stats.read_hit); |
702 | stats.read_misses = atomic_read(&cache->stats.read_miss); | |
703 | stats.write_hits = atomic_read(&cache->stats.write_hit); | |
704 | stats.write_misses = atomic_read(&cache->stats.write_miss); | |
705 | ||
706 | dm_cache_metadata_set_stats(cache->cmd, &stats); | |
707 | } | |
708 | ||
709 | /*---------------------------------------------------------------- | |
710 | * Per bio data | |
711 | *--------------------------------------------------------------*/ | |
19b0092e MS |
712 | |
713 | /* | |
714 | * If using writeback, leave out struct per_bio_data's writethrough fields. | |
715 | */ | |
716 | #define PB_DATA_SIZE_WB (offsetof(struct per_bio_data, cache)) | |
717 | #define PB_DATA_SIZE_WT (sizeof(struct per_bio_data)) | |
718 | ||
2ee57d58 JT |
719 | static bool writethrough_mode(struct cache_features *f) |
720 | { | |
721 | return f->io_mode == CM_IO_WRITETHROUGH; | |
722 | } | |
723 | ||
724 | static bool writeback_mode(struct cache_features *f) | |
725 | { | |
726 | return f->io_mode == CM_IO_WRITEBACK; | |
727 | } | |
728 | ||
729 | static bool passthrough_mode(struct cache_features *f) | |
730 | { | |
731 | return f->io_mode == CM_IO_PASSTHROUGH; | |
732 | } | |
733 | ||
19b0092e MS |
734 | static size_t get_per_bio_data_size(struct cache *cache) |
735 | { | |
2ee57d58 | 736 | return writethrough_mode(&cache->features) ? PB_DATA_SIZE_WT : PB_DATA_SIZE_WB; |
19b0092e MS |
737 | } |
738 | ||
739 | static struct per_bio_data *get_per_bio_data(struct bio *bio, size_t data_size) | |
c6b4fcba | 740 | { |
19b0092e | 741 | struct per_bio_data *pb = dm_per_bio_data(bio, data_size); |
c6b4fcba JT |
742 | BUG_ON(!pb); |
743 | return pb; | |
744 | } | |
745 | ||
19b0092e | 746 | static struct per_bio_data *init_per_bio_data(struct bio *bio, size_t data_size) |
c6b4fcba | 747 | { |
19b0092e | 748 | struct per_bio_data *pb = get_per_bio_data(bio, data_size); |
c6b4fcba JT |
749 | |
750 | pb->tick = false; | |
751 | pb->req_nr = dm_bio_get_target_bio_nr(bio); | |
752 | pb->all_io_entry = NULL; | |
066dbaa3 | 753 | pb->len = 0; |
c6b4fcba JT |
754 | |
755 | return pb; | |
756 | } | |
757 | ||
758 | /*---------------------------------------------------------------- | |
759 | * Remapping | |
760 | *--------------------------------------------------------------*/ | |
761 | static void remap_to_origin(struct cache *cache, struct bio *bio) | |
762 | { | |
763 | bio->bi_bdev = cache->origin_dev->bdev; | |
764 | } | |
765 | ||
766 | static void remap_to_cache(struct cache *cache, struct bio *bio, | |
767 | dm_cblock_t cblock) | |
768 | { | |
4f024f37 | 769 | sector_t bi_sector = bio->bi_iter.bi_sector; |
e0d849fa | 770 | sector_t block = from_cblock(cblock); |
c6b4fcba JT |
771 | |
772 | bio->bi_bdev = cache->cache_dev->bdev; | |
773 | if (!block_size_is_power_of_two(cache)) | |
4f024f37 | 774 | bio->bi_iter.bi_sector = |
e0d849fa | 775 | (block * cache->sectors_per_block) + |
4f024f37 | 776 | sector_div(bi_sector, cache->sectors_per_block); |
c6b4fcba | 777 | else |
4f024f37 | 778 | bio->bi_iter.bi_sector = |
e0d849fa | 779 | (block << cache->sectors_per_block_shift) | |
4f024f37 | 780 | (bi_sector & (cache->sectors_per_block - 1)); |
c6b4fcba JT |
781 | } |
782 | ||
783 | static void check_if_tick_bio_needed(struct cache *cache, struct bio *bio) | |
784 | { | |
785 | unsigned long flags; | |
19b0092e MS |
786 | size_t pb_data_size = get_per_bio_data_size(cache); |
787 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
c6b4fcba JT |
788 | |
789 | spin_lock_irqsave(&cache->lock, flags); | |
790 | if (cache->need_tick_bio && | |
1eff9d32 | 791 | !(bio->bi_opf & (REQ_FUA | REQ_PREFLUSH)) && |
e6047149 | 792 | bio_op(bio) != REQ_OP_DISCARD) { |
c6b4fcba JT |
793 | pb->tick = true; |
794 | cache->need_tick_bio = false; | |
795 | } | |
796 | spin_unlock_irqrestore(&cache->lock, flags); | |
797 | } | |
798 | ||
799 | static void remap_to_origin_clear_discard(struct cache *cache, struct bio *bio, | |
800 | dm_oblock_t oblock) | |
801 | { | |
802 | check_if_tick_bio_needed(cache, bio); | |
803 | remap_to_origin(cache, bio); | |
804 | if (bio_data_dir(bio) == WRITE) | |
1bad9bc4 | 805 | clear_discard(cache, oblock_to_dblock(cache, oblock)); |
c6b4fcba JT |
806 | } |
807 | ||
808 | static void remap_to_cache_dirty(struct cache *cache, struct bio *bio, | |
809 | dm_oblock_t oblock, dm_cblock_t cblock) | |
810 | { | |
f8e5f01a | 811 | check_if_tick_bio_needed(cache, bio); |
c6b4fcba JT |
812 | remap_to_cache(cache, bio, cblock); |
813 | if (bio_data_dir(bio) == WRITE) { | |
814 | set_dirty(cache, oblock, cblock); | |
1bad9bc4 | 815 | clear_discard(cache, oblock_to_dblock(cache, oblock)); |
c6b4fcba JT |
816 | } |
817 | } | |
818 | ||
819 | static dm_oblock_t get_bio_block(struct cache *cache, struct bio *bio) | |
820 | { | |
4f024f37 | 821 | sector_t block_nr = bio->bi_iter.bi_sector; |
c6b4fcba JT |
822 | |
823 | if (!block_size_is_power_of_two(cache)) | |
824 | (void) sector_div(block_nr, cache->sectors_per_block); | |
825 | else | |
826 | block_nr >>= cache->sectors_per_block_shift; | |
827 | ||
828 | return to_oblock(block_nr); | |
829 | } | |
830 | ||
831 | static int bio_triggers_commit(struct cache *cache, struct bio *bio) | |
832 | { | |
1eff9d32 | 833 | return bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); |
c6b4fcba JT |
834 | } |
835 | ||
8c081b52 JT |
836 | /* |
837 | * You must increment the deferred set whilst the prison cell is held. To | |
838 | * encourage this, we ask for 'cell' to be passed in. | |
839 | */ | |
840 | static void inc_ds(struct cache *cache, struct bio *bio, | |
841 | struct dm_bio_prison_cell *cell) | |
842 | { | |
843 | size_t pb_data_size = get_per_bio_data_size(cache); | |
844 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
845 | ||
846 | BUG_ON(!cell); | |
847 | BUG_ON(pb->all_io_entry); | |
848 | ||
849 | pb->all_io_entry = dm_deferred_entry_inc(cache->all_io_ds); | |
850 | } | |
851 | ||
066dbaa3 JT |
852 | static bool accountable_bio(struct cache *cache, struct bio *bio) |
853 | { | |
854 | return ((bio->bi_bdev == cache->origin_dev->bdev) && | |
e6047149 | 855 | bio_op(bio) != REQ_OP_DISCARD); |
066dbaa3 JT |
856 | } |
857 | ||
858 | static void accounted_begin(struct cache *cache, struct bio *bio) | |
859 | { | |
860 | size_t pb_data_size = get_per_bio_data_size(cache); | |
861 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
862 | ||
863 | if (accountable_bio(cache, bio)) { | |
864 | pb->len = bio_sectors(bio); | |
865 | iot_io_begin(&cache->origin_tracker, pb->len); | |
866 | } | |
867 | } | |
868 | ||
869 | static void accounted_complete(struct cache *cache, struct bio *bio) | |
870 | { | |
871 | size_t pb_data_size = get_per_bio_data_size(cache); | |
872 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
873 | ||
874 | iot_io_end(&cache->origin_tracker, pb->len); | |
875 | } | |
876 | ||
877 | static void accounted_request(struct cache *cache, struct bio *bio) | |
878 | { | |
879 | accounted_begin(cache, bio); | |
880 | generic_make_request(bio); | |
881 | } | |
882 | ||
c6b4fcba JT |
883 | static void issue(struct cache *cache, struct bio *bio) |
884 | { | |
885 | unsigned long flags; | |
886 | ||
887 | if (!bio_triggers_commit(cache, bio)) { | |
066dbaa3 | 888 | accounted_request(cache, bio); |
c6b4fcba JT |
889 | return; |
890 | } | |
891 | ||
892 | /* | |
893 | * Batch together any bios that trigger commits and then issue a | |
894 | * single commit for them in do_worker(). | |
895 | */ | |
896 | spin_lock_irqsave(&cache->lock, flags); | |
897 | cache->commit_requested = true; | |
898 | bio_list_add(&cache->deferred_flush_bios, bio); | |
899 | spin_unlock_irqrestore(&cache->lock, flags); | |
900 | } | |
901 | ||
8c081b52 JT |
902 | static void inc_and_issue(struct cache *cache, struct bio *bio, struct dm_bio_prison_cell *cell) |
903 | { | |
904 | inc_ds(cache, bio, cell); | |
905 | issue(cache, bio); | |
906 | } | |
907 | ||
e2e74d61 JT |
908 | static void defer_writethrough_bio(struct cache *cache, struct bio *bio) |
909 | { | |
910 | unsigned long flags; | |
911 | ||
912 | spin_lock_irqsave(&cache->lock, flags); | |
913 | bio_list_add(&cache->deferred_writethrough_bios, bio); | |
914 | spin_unlock_irqrestore(&cache->lock, flags); | |
915 | ||
916 | wake_worker(cache); | |
917 | } | |
918 | ||
4246a0b6 | 919 | static void writethrough_endio(struct bio *bio) |
e2e74d61 | 920 | { |
19b0092e | 921 | struct per_bio_data *pb = get_per_bio_data(bio, PB_DATA_SIZE_WT); |
c9d28d5d JT |
922 | |
923 | dm_unhook_bio(&pb->hook_info, bio); | |
e2e74d61 | 924 | |
4246a0b6 CH |
925 | if (bio->bi_error) { |
926 | bio_endio(bio); | |
e2e74d61 JT |
927 | return; |
928 | } | |
929 | ||
b844fe69 | 930 | dm_bio_restore(&pb->bio_details, bio); |
e2e74d61 JT |
931 | remap_to_cache(pb->cache, bio, pb->cblock); |
932 | ||
933 | /* | |
934 | * We can't issue this bio directly, since we're in interrupt | |
aeed1420 | 935 | * context. So it gets put on a bio list for processing by the |
e2e74d61 JT |
936 | * worker thread. |
937 | */ | |
938 | defer_writethrough_bio(pb->cache, bio); | |
939 | } | |
940 | ||
941 | /* | |
942 | * When running in writethrough mode we need to send writes to clean blocks | |
943 | * to both the cache and origin devices. In future we'd like to clone the | |
944 | * bio and send them in parallel, but for now we're doing them in | |
945 | * series as this is easier. | |
946 | */ | |
947 | static void remap_to_origin_then_cache(struct cache *cache, struct bio *bio, | |
948 | dm_oblock_t oblock, dm_cblock_t cblock) | |
949 | { | |
19b0092e | 950 | struct per_bio_data *pb = get_per_bio_data(bio, PB_DATA_SIZE_WT); |
e2e74d61 JT |
951 | |
952 | pb->cache = cache; | |
953 | pb->cblock = cblock; | |
c9d28d5d | 954 | dm_hook_bio(&pb->hook_info, bio, writethrough_endio, NULL); |
b844fe69 | 955 | dm_bio_record(&pb->bio_details, bio); |
e2e74d61 JT |
956 | |
957 | remap_to_origin_clear_discard(pb->cache, bio, oblock); | |
958 | } | |
959 | ||
028ae9f7 JT |
960 | /*---------------------------------------------------------------- |
961 | * Failure modes | |
962 | *--------------------------------------------------------------*/ | |
963 | static enum cache_metadata_mode get_cache_mode(struct cache *cache) | |
964 | { | |
965 | return cache->features.mode; | |
966 | } | |
967 | ||
b61d9509 MS |
968 | static const char *cache_device_name(struct cache *cache) |
969 | { | |
970 | return dm_device_name(dm_table_get_md(cache->ti->table)); | |
971 | } | |
972 | ||
028ae9f7 JT |
973 | static void notify_mode_switch(struct cache *cache, enum cache_metadata_mode mode) |
974 | { | |
975 | const char *descs[] = { | |
976 | "write", | |
977 | "read-only", | |
978 | "fail" | |
979 | }; | |
980 | ||
981 | dm_table_event(cache->ti->table); | |
b61d9509 MS |
982 | DMINFO("%s: switching cache to %s mode", |
983 | cache_device_name(cache), descs[(int)mode]); | |
028ae9f7 JT |
984 | } |
985 | ||
986 | static void set_cache_mode(struct cache *cache, enum cache_metadata_mode new_mode) | |
987 | { | |
d14fcf3d | 988 | bool needs_check; |
028ae9f7 JT |
989 | enum cache_metadata_mode old_mode = get_cache_mode(cache); |
990 | ||
d14fcf3d JT |
991 | if (dm_cache_metadata_needs_check(cache->cmd, &needs_check)) { |
992 | DMERR("unable to read needs_check flag, setting failure mode"); | |
993 | new_mode = CM_FAIL; | |
994 | } | |
995 | ||
028ae9f7 | 996 | if (new_mode == CM_WRITE && needs_check) { |
b61d9509 MS |
997 | DMERR("%s: unable to switch cache to write mode until repaired.", |
998 | cache_device_name(cache)); | |
028ae9f7 JT |
999 | if (old_mode != new_mode) |
1000 | new_mode = old_mode; | |
1001 | else | |
1002 | new_mode = CM_READ_ONLY; | |
1003 | } | |
1004 | ||
1005 | /* Never move out of fail mode */ | |
1006 | if (old_mode == CM_FAIL) | |
1007 | new_mode = CM_FAIL; | |
1008 | ||
1009 | switch (new_mode) { | |
1010 | case CM_FAIL: | |
1011 | case CM_READ_ONLY: | |
1012 | dm_cache_metadata_set_read_only(cache->cmd); | |
1013 | break; | |
1014 | ||
1015 | case CM_WRITE: | |
1016 | dm_cache_metadata_set_read_write(cache->cmd); | |
1017 | break; | |
1018 | } | |
1019 | ||
1020 | cache->features.mode = new_mode; | |
1021 | ||
1022 | if (new_mode != old_mode) | |
1023 | notify_mode_switch(cache, new_mode); | |
1024 | } | |
1025 | ||
1026 | static void abort_transaction(struct cache *cache) | |
1027 | { | |
b61d9509 MS |
1028 | const char *dev_name = cache_device_name(cache); |
1029 | ||
028ae9f7 JT |
1030 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
1031 | return; | |
1032 | ||
1033 | if (dm_cache_metadata_set_needs_check(cache->cmd)) { | |
b61d9509 | 1034 | DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name); |
028ae9f7 JT |
1035 | set_cache_mode(cache, CM_FAIL); |
1036 | } | |
1037 | ||
b61d9509 | 1038 | DMERR_LIMIT("%s: aborting current metadata transaction", dev_name); |
028ae9f7 | 1039 | if (dm_cache_metadata_abort(cache->cmd)) { |
b61d9509 | 1040 | DMERR("%s: failed to abort metadata transaction", dev_name); |
028ae9f7 JT |
1041 | set_cache_mode(cache, CM_FAIL); |
1042 | } | |
1043 | } | |
1044 | ||
1045 | static void metadata_operation_failed(struct cache *cache, const char *op, int r) | |
1046 | { | |
b61d9509 MS |
1047 | DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d", |
1048 | cache_device_name(cache), op, r); | |
028ae9f7 JT |
1049 | abort_transaction(cache); |
1050 | set_cache_mode(cache, CM_READ_ONLY); | |
1051 | } | |
1052 | ||
c6b4fcba JT |
1053 | /*---------------------------------------------------------------- |
1054 | * Migration processing | |
1055 | * | |
1056 | * Migration covers moving data from the origin device to the cache, or | |
1057 | * vice versa. | |
1058 | *--------------------------------------------------------------*/ | |
a59db676 | 1059 | static void inc_io_migrations(struct cache *cache) |
c6b4fcba | 1060 | { |
a59db676 | 1061 | atomic_inc(&cache->nr_io_migrations); |
c6b4fcba JT |
1062 | } |
1063 | ||
a59db676 | 1064 | static void dec_io_migrations(struct cache *cache) |
c6b4fcba | 1065 | { |
a59db676 | 1066 | atomic_dec(&cache->nr_io_migrations); |
c6b4fcba JT |
1067 | } |
1068 | ||
651f5fa2 JT |
1069 | static bool discard_or_flush(struct bio *bio) |
1070 | { | |
e6047149 | 1071 | return bio_op(bio) == REQ_OP_DISCARD || |
1eff9d32 | 1072 | bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); |
651f5fa2 JT |
1073 | } |
1074 | ||
1075 | static void __cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell) | |
1076 | { | |
dc9cee5d | 1077 | if (discard_or_flush(cell->holder)) { |
651f5fa2 | 1078 | /* |
dc9cee5d | 1079 | * We have to handle these bios individually. |
651f5fa2 | 1080 | */ |
dc9cee5d MS |
1081 | dm_cell_release(cache->prison, cell, &cache->deferred_bios); |
1082 | free_prison_cell(cache, cell); | |
1083 | } else | |
651f5fa2 JT |
1084 | list_add_tail(&cell->user_list, &cache->deferred_cells); |
1085 | } | |
1086 | ||
1087 | static void cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell, bool holder) | |
c6b4fcba JT |
1088 | { |
1089 | unsigned long flags; | |
1090 | ||
651f5fa2 JT |
1091 | if (!holder && dm_cell_promote_or_release(cache->prison, cell)) { |
1092 | /* | |
1093 | * There was no prisoner to promote to holder, the | |
1094 | * cell has been released. | |
1095 | */ | |
1096 | free_prison_cell(cache, cell); | |
1097 | return; | |
1098 | } | |
1099 | ||
c6b4fcba | 1100 | spin_lock_irqsave(&cache->lock, flags); |
651f5fa2 | 1101 | __cell_defer(cache, cell); |
c6b4fcba JT |
1102 | spin_unlock_irqrestore(&cache->lock, flags); |
1103 | ||
1104 | wake_worker(cache); | |
1105 | } | |
1106 | ||
651f5fa2 JT |
1107 | static void cell_error_with_code(struct cache *cache, struct dm_bio_prison_cell *cell, int err) |
1108 | { | |
1109 | dm_cell_error(cache->prison, cell, err); | |
dc9cee5d | 1110 | free_prison_cell(cache, cell); |
651f5fa2 JT |
1111 | } |
1112 | ||
1113 | static void cell_requeue(struct cache *cache, struct dm_bio_prison_cell *cell) | |
1114 | { | |
1115 | cell_error_with_code(cache, cell, DM_ENDIO_REQUEUE); | |
1116 | } | |
1117 | ||
a59db676 | 1118 | static void free_io_migration(struct dm_cache_migration *mg) |
c6b4fcba | 1119 | { |
cc7da0ba JT |
1120 | struct cache *cache = mg->cache; |
1121 | ||
1122 | dec_io_migrations(cache); | |
c6b4fcba | 1123 | free_migration(mg); |
cc7da0ba | 1124 | wake_worker(cache); |
c6b4fcba JT |
1125 | } |
1126 | ||
1127 | static void migration_failure(struct dm_cache_migration *mg) | |
1128 | { | |
1129 | struct cache *cache = mg->cache; | |
b61d9509 | 1130 | const char *dev_name = cache_device_name(cache); |
c6b4fcba JT |
1131 | |
1132 | if (mg->writeback) { | |
b61d9509 | 1133 | DMERR_LIMIT("%s: writeback failed; couldn't copy block", dev_name); |
c6b4fcba JT |
1134 | set_dirty(cache, mg->old_oblock, mg->cblock); |
1135 | cell_defer(cache, mg->old_ocell, false); | |
1136 | ||
1137 | } else if (mg->demote) { | |
b61d9509 | 1138 | DMERR_LIMIT("%s: demotion failed; couldn't copy block", dev_name); |
c6b4fcba JT |
1139 | policy_force_mapping(cache->policy, mg->new_oblock, mg->old_oblock); |
1140 | ||
80f659f3 | 1141 | cell_defer(cache, mg->old_ocell, mg->promote ? false : true); |
c6b4fcba | 1142 | if (mg->promote) |
80f659f3 | 1143 | cell_defer(cache, mg->new_ocell, true); |
c6b4fcba | 1144 | } else { |
b61d9509 | 1145 | DMERR_LIMIT("%s: promotion failed; couldn't copy block", dev_name); |
c6b4fcba | 1146 | policy_remove_mapping(cache->policy, mg->new_oblock); |
80f659f3 | 1147 | cell_defer(cache, mg->new_ocell, true); |
c6b4fcba JT |
1148 | } |
1149 | ||
a59db676 | 1150 | free_io_migration(mg); |
c6b4fcba JT |
1151 | } |
1152 | ||
1153 | static void migration_success_pre_commit(struct dm_cache_migration *mg) | |
1154 | { | |
028ae9f7 | 1155 | int r; |
c6b4fcba JT |
1156 | unsigned long flags; |
1157 | struct cache *cache = mg->cache; | |
1158 | ||
1159 | if (mg->writeback) { | |
c6b4fcba | 1160 | clear_dirty(cache, mg->old_oblock, mg->cblock); |
40aa978e | 1161 | cell_defer(cache, mg->old_ocell, false); |
a59db676 | 1162 | free_io_migration(mg); |
c6b4fcba JT |
1163 | return; |
1164 | ||
1165 | } else if (mg->demote) { | |
028ae9f7 JT |
1166 | r = dm_cache_remove_mapping(cache->cmd, mg->cblock); |
1167 | if (r) { | |
b61d9509 MS |
1168 | DMERR_LIMIT("%s: demotion failed; couldn't update on disk metadata", |
1169 | cache_device_name(cache)); | |
028ae9f7 | 1170 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); |
c6b4fcba JT |
1171 | policy_force_mapping(cache->policy, mg->new_oblock, |
1172 | mg->old_oblock); | |
1173 | if (mg->promote) | |
1174 | cell_defer(cache, mg->new_ocell, true); | |
a59db676 | 1175 | free_io_migration(mg); |
c6b4fcba JT |
1176 | return; |
1177 | } | |
1178 | } else { | |
028ae9f7 JT |
1179 | r = dm_cache_insert_mapping(cache->cmd, mg->cblock, mg->new_oblock); |
1180 | if (r) { | |
b61d9509 MS |
1181 | DMERR_LIMIT("%s: promotion failed; couldn't update on disk metadata", |
1182 | cache_device_name(cache)); | |
028ae9f7 | 1183 | metadata_operation_failed(cache, "dm_cache_insert_mapping", r); |
c6b4fcba | 1184 | policy_remove_mapping(cache->policy, mg->new_oblock); |
a59db676 | 1185 | free_io_migration(mg); |
c6b4fcba JT |
1186 | return; |
1187 | } | |
1188 | } | |
1189 | ||
1190 | spin_lock_irqsave(&cache->lock, flags); | |
1191 | list_add_tail(&mg->list, &cache->need_commit_migrations); | |
1192 | cache->commit_requested = true; | |
1193 | spin_unlock_irqrestore(&cache->lock, flags); | |
1194 | } | |
1195 | ||
1196 | static void migration_success_post_commit(struct dm_cache_migration *mg) | |
1197 | { | |
1198 | unsigned long flags; | |
1199 | struct cache *cache = mg->cache; | |
1200 | ||
1201 | if (mg->writeback) { | |
b61d9509 MS |
1202 | DMWARN_LIMIT("%s: writeback unexpectedly triggered commit", |
1203 | cache_device_name(cache)); | |
c6b4fcba JT |
1204 | return; |
1205 | ||
1206 | } else if (mg->demote) { | |
80f659f3 | 1207 | cell_defer(cache, mg->old_ocell, mg->promote ? false : true); |
c6b4fcba JT |
1208 | |
1209 | if (mg->promote) { | |
1210 | mg->demote = false; | |
1211 | ||
1212 | spin_lock_irqsave(&cache->lock, flags); | |
1213 | list_add_tail(&mg->list, &cache->quiesced_migrations); | |
1214 | spin_unlock_irqrestore(&cache->lock, flags); | |
1215 | ||
65790ff9 JT |
1216 | } else { |
1217 | if (mg->invalidate) | |
1218 | policy_remove_mapping(cache->policy, mg->old_oblock); | |
a59db676 | 1219 | free_io_migration(mg); |
65790ff9 | 1220 | } |
c6b4fcba JT |
1221 | |
1222 | } else { | |
1e32134a JT |
1223 | if (mg->requeue_holder) { |
1224 | clear_dirty(cache, mg->new_oblock, mg->cblock); | |
c9d28d5d | 1225 | cell_defer(cache, mg->new_ocell, true); |
1e32134a JT |
1226 | } else { |
1227 | /* | |
1228 | * The block was promoted via an overwrite, so it's dirty. | |
1229 | */ | |
1230 | set_dirty(cache, mg->new_oblock, mg->cblock); | |
4246a0b6 | 1231 | bio_endio(mg->new_ocell->holder); |
c9d28d5d JT |
1232 | cell_defer(cache, mg->new_ocell, false); |
1233 | } | |
a59db676 | 1234 | free_io_migration(mg); |
c6b4fcba JT |
1235 | } |
1236 | } | |
1237 | ||
1238 | static void copy_complete(int read_err, unsigned long write_err, void *context) | |
1239 | { | |
1240 | unsigned long flags; | |
1241 | struct dm_cache_migration *mg = (struct dm_cache_migration *) context; | |
1242 | struct cache *cache = mg->cache; | |
1243 | ||
1244 | if (read_err || write_err) | |
1245 | mg->err = true; | |
1246 | ||
1247 | spin_lock_irqsave(&cache->lock, flags); | |
1248 | list_add_tail(&mg->list, &cache->completed_migrations); | |
1249 | spin_unlock_irqrestore(&cache->lock, flags); | |
1250 | ||
1251 | wake_worker(cache); | |
1252 | } | |
1253 | ||
7ae34e77 | 1254 | static void issue_copy(struct dm_cache_migration *mg) |
c6b4fcba JT |
1255 | { |
1256 | int r; | |
1257 | struct dm_io_region o_region, c_region; | |
1258 | struct cache *cache = mg->cache; | |
8b9d9666 | 1259 | sector_t cblock = from_cblock(mg->cblock); |
c6b4fcba JT |
1260 | |
1261 | o_region.bdev = cache->origin_dev->bdev; | |
1262 | o_region.count = cache->sectors_per_block; | |
1263 | ||
1264 | c_region.bdev = cache->cache_dev->bdev; | |
8b9d9666 | 1265 | c_region.sector = cblock * cache->sectors_per_block; |
c6b4fcba JT |
1266 | c_region.count = cache->sectors_per_block; |
1267 | ||
1268 | if (mg->writeback || mg->demote) { | |
1269 | /* demote */ | |
1270 | o_region.sector = from_oblock(mg->old_oblock) * cache->sectors_per_block; | |
1271 | r = dm_kcopyd_copy(cache->copier, &c_region, 1, &o_region, 0, copy_complete, mg); | |
1272 | } else { | |
1273 | /* promote */ | |
1274 | o_region.sector = from_oblock(mg->new_oblock) * cache->sectors_per_block; | |
1275 | r = dm_kcopyd_copy(cache->copier, &o_region, 1, &c_region, 0, copy_complete, mg); | |
1276 | } | |
1277 | ||
2c2263c9 | 1278 | if (r < 0) { |
b61d9509 | 1279 | DMERR_LIMIT("%s: issuing migration failed", cache_device_name(cache)); |
c6b4fcba | 1280 | migration_failure(mg); |
2c2263c9 | 1281 | } |
c6b4fcba JT |
1282 | } |
1283 | ||
4246a0b6 | 1284 | static void overwrite_endio(struct bio *bio) |
c9d28d5d JT |
1285 | { |
1286 | struct dm_cache_migration *mg = bio->bi_private; | |
1287 | struct cache *cache = mg->cache; | |
1288 | size_t pb_data_size = get_per_bio_data_size(cache); | |
1289 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
1290 | unsigned long flags; | |
1291 | ||
80ae49aa MS |
1292 | dm_unhook_bio(&pb->hook_info, bio); |
1293 | ||
4246a0b6 | 1294 | if (bio->bi_error) |
c9d28d5d JT |
1295 | mg->err = true; |
1296 | ||
80ae49aa MS |
1297 | mg->requeue_holder = false; |
1298 | ||
c9d28d5d JT |
1299 | spin_lock_irqsave(&cache->lock, flags); |
1300 | list_add_tail(&mg->list, &cache->completed_migrations); | |
c9d28d5d JT |
1301 | spin_unlock_irqrestore(&cache->lock, flags); |
1302 | ||
1303 | wake_worker(cache); | |
1304 | } | |
1305 | ||
1306 | static void issue_overwrite(struct dm_cache_migration *mg, struct bio *bio) | |
1307 | { | |
1308 | size_t pb_data_size = get_per_bio_data_size(mg->cache); | |
1309 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
1310 | ||
1311 | dm_hook_bio(&pb->hook_info, bio, overwrite_endio, mg); | |
1312 | remap_to_cache_dirty(mg->cache, bio, mg->new_oblock, mg->cblock); | |
8c081b52 JT |
1313 | |
1314 | /* | |
1315 | * No need to inc_ds() here, since the cell will be held for the | |
1316 | * duration of the io. | |
1317 | */ | |
066dbaa3 | 1318 | accounted_request(mg->cache, bio); |
c9d28d5d JT |
1319 | } |
1320 | ||
1321 | static bool bio_writes_complete_block(struct cache *cache, struct bio *bio) | |
1322 | { | |
1323 | return (bio_data_dir(bio) == WRITE) && | |
4f024f37 | 1324 | (bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT)); |
c9d28d5d JT |
1325 | } |
1326 | ||
c6b4fcba JT |
1327 | static void avoid_copy(struct dm_cache_migration *mg) |
1328 | { | |
1329 | atomic_inc(&mg->cache->stats.copies_avoided); | |
1330 | migration_success_pre_commit(mg); | |
1331 | } | |
1332 | ||
7ae34e77 JT |
1333 | static void calc_discard_block_range(struct cache *cache, struct bio *bio, |
1334 | dm_dblock_t *b, dm_dblock_t *e) | |
1335 | { | |
1336 | sector_t sb = bio->bi_iter.bi_sector; | |
1337 | sector_t se = bio_end_sector(bio); | |
1338 | ||
1339 | *b = to_dblock(dm_sector_div_up(sb, cache->discard_block_size)); | |
1340 | ||
1341 | if (se - sb < cache->discard_block_size) | |
1342 | *e = *b; | |
1343 | else | |
1344 | *e = to_dblock(block_div(se, cache->discard_block_size)); | |
1345 | } | |
1346 | ||
1347 | static void issue_discard(struct dm_cache_migration *mg) | |
1348 | { | |
1349 | dm_dblock_t b, e; | |
1350 | struct bio *bio = mg->new_ocell->holder; | |
cc7da0ba | 1351 | struct cache *cache = mg->cache; |
7ae34e77 | 1352 | |
cc7da0ba | 1353 | calc_discard_block_range(cache, bio, &b, &e); |
7ae34e77 | 1354 | while (b != e) { |
cc7da0ba | 1355 | set_discard(cache, b); |
7ae34e77 JT |
1356 | b = to_dblock(from_dblock(b) + 1); |
1357 | } | |
1358 | ||
4246a0b6 | 1359 | bio_endio(bio); |
cc7da0ba | 1360 | cell_defer(cache, mg->new_ocell, false); |
7ae34e77 | 1361 | free_migration(mg); |
cc7da0ba | 1362 | wake_worker(cache); |
7ae34e77 JT |
1363 | } |
1364 | ||
1365 | static void issue_copy_or_discard(struct dm_cache_migration *mg) | |
c6b4fcba JT |
1366 | { |
1367 | bool avoid; | |
1368 | struct cache *cache = mg->cache; | |
1369 | ||
7ae34e77 JT |
1370 | if (mg->discard) { |
1371 | issue_discard(mg); | |
1372 | return; | |
1373 | } | |
1374 | ||
c6b4fcba JT |
1375 | if (mg->writeback || mg->demote) |
1376 | avoid = !is_dirty(cache, mg->cblock) || | |
1377 | is_discarded_oblock(cache, mg->old_oblock); | |
c9d28d5d JT |
1378 | else { |
1379 | struct bio *bio = mg->new_ocell->holder; | |
1380 | ||
c6b4fcba JT |
1381 | avoid = is_discarded_oblock(cache, mg->new_oblock); |
1382 | ||
f29a3147 JT |
1383 | if (writeback_mode(&cache->features) && |
1384 | !avoid && bio_writes_complete_block(cache, bio)) { | |
c9d28d5d JT |
1385 | issue_overwrite(mg, bio); |
1386 | return; | |
1387 | } | |
1388 | } | |
1389 | ||
7ae34e77 | 1390 | avoid ? avoid_copy(mg) : issue_copy(mg); |
c6b4fcba JT |
1391 | } |
1392 | ||
1393 | static void complete_migration(struct dm_cache_migration *mg) | |
1394 | { | |
1395 | if (mg->err) | |
1396 | migration_failure(mg); | |
1397 | else | |
1398 | migration_success_pre_commit(mg); | |
1399 | } | |
1400 | ||
1401 | static void process_migrations(struct cache *cache, struct list_head *head, | |
1402 | void (*fn)(struct dm_cache_migration *)) | |
1403 | { | |
1404 | unsigned long flags; | |
1405 | struct list_head list; | |
1406 | struct dm_cache_migration *mg, *tmp; | |
1407 | ||
1408 | INIT_LIST_HEAD(&list); | |
1409 | spin_lock_irqsave(&cache->lock, flags); | |
1410 | list_splice_init(head, &list); | |
1411 | spin_unlock_irqrestore(&cache->lock, flags); | |
1412 | ||
1413 | list_for_each_entry_safe(mg, tmp, &list, list) | |
1414 | fn(mg); | |
1415 | } | |
1416 | ||
1417 | static void __queue_quiesced_migration(struct dm_cache_migration *mg) | |
1418 | { | |
1419 | list_add_tail(&mg->list, &mg->cache->quiesced_migrations); | |
1420 | } | |
1421 | ||
1422 | static void queue_quiesced_migration(struct dm_cache_migration *mg) | |
1423 | { | |
1424 | unsigned long flags; | |
1425 | struct cache *cache = mg->cache; | |
1426 | ||
1427 | spin_lock_irqsave(&cache->lock, flags); | |
1428 | __queue_quiesced_migration(mg); | |
1429 | spin_unlock_irqrestore(&cache->lock, flags); | |
1430 | ||
1431 | wake_worker(cache); | |
1432 | } | |
1433 | ||
1434 | static void queue_quiesced_migrations(struct cache *cache, struct list_head *work) | |
1435 | { | |
1436 | unsigned long flags; | |
1437 | struct dm_cache_migration *mg, *tmp; | |
1438 | ||
1439 | spin_lock_irqsave(&cache->lock, flags); | |
1440 | list_for_each_entry_safe(mg, tmp, work, list) | |
1441 | __queue_quiesced_migration(mg); | |
1442 | spin_unlock_irqrestore(&cache->lock, flags); | |
1443 | ||
1444 | wake_worker(cache); | |
1445 | } | |
1446 | ||
1447 | static void check_for_quiesced_migrations(struct cache *cache, | |
1448 | struct per_bio_data *pb) | |
1449 | { | |
1450 | struct list_head work; | |
1451 | ||
1452 | if (!pb->all_io_entry) | |
1453 | return; | |
1454 | ||
1455 | INIT_LIST_HEAD(&work); | |
8c081b52 | 1456 | dm_deferred_entry_dec(pb->all_io_entry, &work); |
c6b4fcba JT |
1457 | |
1458 | if (!list_empty(&work)) | |
1459 | queue_quiesced_migrations(cache, &work); | |
1460 | } | |
1461 | ||
1462 | static void quiesce_migration(struct dm_cache_migration *mg) | |
1463 | { | |
1464 | if (!dm_deferred_set_add_work(mg->cache->all_io_ds, &mg->list)) | |
1465 | queue_quiesced_migration(mg); | |
1466 | } | |
1467 | ||
1468 | static void promote(struct cache *cache, struct prealloc *structs, | |
1469 | dm_oblock_t oblock, dm_cblock_t cblock, | |
1470 | struct dm_bio_prison_cell *cell) | |
1471 | { | |
1472 | struct dm_cache_migration *mg = prealloc_get_migration(structs); | |
1473 | ||
1474 | mg->err = false; | |
7ae34e77 | 1475 | mg->discard = false; |
c6b4fcba JT |
1476 | mg->writeback = false; |
1477 | mg->demote = false; | |
1478 | mg->promote = true; | |
c9d28d5d | 1479 | mg->requeue_holder = true; |
65790ff9 | 1480 | mg->invalidate = false; |
c6b4fcba JT |
1481 | mg->cache = cache; |
1482 | mg->new_oblock = oblock; | |
1483 | mg->cblock = cblock; | |
1484 | mg->old_ocell = NULL; | |
1485 | mg->new_ocell = cell; | |
1486 | mg->start_jiffies = jiffies; | |
1487 | ||
a59db676 | 1488 | inc_io_migrations(cache); |
c6b4fcba JT |
1489 | quiesce_migration(mg); |
1490 | } | |
1491 | ||
1492 | static void writeback(struct cache *cache, struct prealloc *structs, | |
1493 | dm_oblock_t oblock, dm_cblock_t cblock, | |
1494 | struct dm_bio_prison_cell *cell) | |
1495 | { | |
1496 | struct dm_cache_migration *mg = prealloc_get_migration(structs); | |
1497 | ||
1498 | mg->err = false; | |
7ae34e77 | 1499 | mg->discard = false; |
c6b4fcba JT |
1500 | mg->writeback = true; |
1501 | mg->demote = false; | |
1502 | mg->promote = false; | |
c9d28d5d | 1503 | mg->requeue_holder = true; |
65790ff9 | 1504 | mg->invalidate = false; |
c6b4fcba JT |
1505 | mg->cache = cache; |
1506 | mg->old_oblock = oblock; | |
1507 | mg->cblock = cblock; | |
1508 | mg->old_ocell = cell; | |
1509 | mg->new_ocell = NULL; | |
1510 | mg->start_jiffies = jiffies; | |
1511 | ||
a59db676 | 1512 | inc_io_migrations(cache); |
c6b4fcba JT |
1513 | quiesce_migration(mg); |
1514 | } | |
1515 | ||
1516 | static void demote_then_promote(struct cache *cache, struct prealloc *structs, | |
1517 | dm_oblock_t old_oblock, dm_oblock_t new_oblock, | |
1518 | dm_cblock_t cblock, | |
1519 | struct dm_bio_prison_cell *old_ocell, | |
1520 | struct dm_bio_prison_cell *new_ocell) | |
1521 | { | |
1522 | struct dm_cache_migration *mg = prealloc_get_migration(structs); | |
1523 | ||
1524 | mg->err = false; | |
7ae34e77 | 1525 | mg->discard = false; |
c6b4fcba JT |
1526 | mg->writeback = false; |
1527 | mg->demote = true; | |
1528 | mg->promote = true; | |
c9d28d5d | 1529 | mg->requeue_holder = true; |
65790ff9 | 1530 | mg->invalidate = false; |
c6b4fcba JT |
1531 | mg->cache = cache; |
1532 | mg->old_oblock = old_oblock; | |
1533 | mg->new_oblock = new_oblock; | |
1534 | mg->cblock = cblock; | |
1535 | mg->old_ocell = old_ocell; | |
1536 | mg->new_ocell = new_ocell; | |
1537 | mg->start_jiffies = jiffies; | |
1538 | ||
a59db676 | 1539 | inc_io_migrations(cache); |
c6b4fcba JT |
1540 | quiesce_migration(mg); |
1541 | } | |
1542 | ||
2ee57d58 JT |
1543 | /* |
1544 | * Invalidate a cache entry. No writeback occurs; any changes in the cache | |
1545 | * block are thrown away. | |
1546 | */ | |
1547 | static void invalidate(struct cache *cache, struct prealloc *structs, | |
1548 | dm_oblock_t oblock, dm_cblock_t cblock, | |
1549 | struct dm_bio_prison_cell *cell) | |
1550 | { | |
1551 | struct dm_cache_migration *mg = prealloc_get_migration(structs); | |
1552 | ||
1553 | mg->err = false; | |
7ae34e77 | 1554 | mg->discard = false; |
2ee57d58 JT |
1555 | mg->writeback = false; |
1556 | mg->demote = true; | |
1557 | mg->promote = false; | |
1558 | mg->requeue_holder = true; | |
65790ff9 | 1559 | mg->invalidate = true; |
2ee57d58 JT |
1560 | mg->cache = cache; |
1561 | mg->old_oblock = oblock; | |
1562 | mg->cblock = cblock; | |
1563 | mg->old_ocell = cell; | |
1564 | mg->new_ocell = NULL; | |
1565 | mg->start_jiffies = jiffies; | |
1566 | ||
a59db676 | 1567 | inc_io_migrations(cache); |
2ee57d58 JT |
1568 | quiesce_migration(mg); |
1569 | } | |
1570 | ||
7ae34e77 JT |
1571 | static void discard(struct cache *cache, struct prealloc *structs, |
1572 | struct dm_bio_prison_cell *cell) | |
1573 | { | |
1574 | struct dm_cache_migration *mg = prealloc_get_migration(structs); | |
1575 | ||
1576 | mg->err = false; | |
1577 | mg->discard = true; | |
1578 | mg->writeback = false; | |
1579 | mg->demote = false; | |
1580 | mg->promote = false; | |
1581 | mg->requeue_holder = false; | |
1582 | mg->invalidate = false; | |
1583 | mg->cache = cache; | |
1584 | mg->old_ocell = NULL; | |
1585 | mg->new_ocell = cell; | |
1586 | mg->start_jiffies = jiffies; | |
1587 | ||
1588 | quiesce_migration(mg); | |
1589 | } | |
1590 | ||
c6b4fcba JT |
1591 | /*---------------------------------------------------------------- |
1592 | * bio processing | |
1593 | *--------------------------------------------------------------*/ | |
1594 | static void defer_bio(struct cache *cache, struct bio *bio) | |
1595 | { | |
1596 | unsigned long flags; | |
1597 | ||
1598 | spin_lock_irqsave(&cache->lock, flags); | |
1599 | bio_list_add(&cache->deferred_bios, bio); | |
1600 | spin_unlock_irqrestore(&cache->lock, flags); | |
1601 | ||
1602 | wake_worker(cache); | |
1603 | } | |
1604 | ||
1605 | static void process_flush_bio(struct cache *cache, struct bio *bio) | |
1606 | { | |
19b0092e MS |
1607 | size_t pb_data_size = get_per_bio_data_size(cache); |
1608 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
c6b4fcba | 1609 | |
4f024f37 | 1610 | BUG_ON(bio->bi_iter.bi_size); |
c6b4fcba JT |
1611 | if (!pb->req_nr) |
1612 | remap_to_origin(cache, bio); | |
1613 | else | |
1614 | remap_to_cache(cache, bio, 0); | |
1615 | ||
8c081b52 | 1616 | /* |
28a8f0d3 MC |
1617 | * REQ_PREFLUSH is not directed at any particular block so we don't |
1618 | * need to inc_ds(). REQ_FUA's are split into a write + REQ_PREFLUSH | |
8c081b52 JT |
1619 | * by dm-core. |
1620 | */ | |
c6b4fcba JT |
1621 | issue(cache, bio); |
1622 | } | |
1623 | ||
7ae34e77 JT |
1624 | static void process_discard_bio(struct cache *cache, struct prealloc *structs, |
1625 | struct bio *bio) | |
c6b4fcba | 1626 | { |
7ae34e77 JT |
1627 | int r; |
1628 | dm_dblock_t b, e; | |
1629 | struct dm_bio_prison_cell *cell_prealloc, *new_ocell; | |
c6b4fcba | 1630 | |
7ae34e77 JT |
1631 | calc_discard_block_range(cache, bio, &b, &e); |
1632 | if (b == e) { | |
4246a0b6 | 1633 | bio_endio(bio); |
7ae34e77 JT |
1634 | return; |
1635 | } | |
c6b4fcba | 1636 | |
7ae34e77 JT |
1637 | cell_prealloc = prealloc_get_cell(structs); |
1638 | r = bio_detain_range(cache, dblock_to_oblock(cache, b), dblock_to_oblock(cache, e), bio, cell_prealloc, | |
1639 | (cell_free_fn) prealloc_put_cell, | |
1640 | structs, &new_ocell); | |
1641 | if (r > 0) | |
1642 | return; | |
c6b4fcba | 1643 | |
7ae34e77 | 1644 | discard(cache, structs, new_ocell); |
c6b4fcba JT |
1645 | } |
1646 | ||
1647 | static bool spare_migration_bandwidth(struct cache *cache) | |
1648 | { | |
a59db676 | 1649 | sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) * |
c6b4fcba JT |
1650 | cache->sectors_per_block; |
1651 | return current_volume < cache->migration_threshold; | |
1652 | } | |
1653 | ||
c6b4fcba JT |
1654 | static void inc_hit_counter(struct cache *cache, struct bio *bio) |
1655 | { | |
1656 | atomic_inc(bio_data_dir(bio) == READ ? | |
1657 | &cache->stats.read_hit : &cache->stats.write_hit); | |
1658 | } | |
1659 | ||
1660 | static void inc_miss_counter(struct cache *cache, struct bio *bio) | |
1661 | { | |
1662 | atomic_inc(bio_data_dir(bio) == READ ? | |
1663 | &cache->stats.read_miss : &cache->stats.write_miss); | |
1664 | } | |
1665 | ||
fb4100ae JT |
1666 | /*----------------------------------------------------------------*/ |
1667 | ||
651f5fa2 JT |
1668 | struct inc_detail { |
1669 | struct cache *cache; | |
1670 | struct bio_list bios_for_issue; | |
1671 | struct bio_list unhandled_bios; | |
1672 | bool any_writes; | |
1673 | }; | |
1674 | ||
1675 | static void inc_fn(void *context, struct dm_bio_prison_cell *cell) | |
1676 | { | |
1677 | struct bio *bio; | |
1678 | struct inc_detail *detail = context; | |
1679 | struct cache *cache = detail->cache; | |
1680 | ||
1681 | inc_ds(cache, cell->holder, cell); | |
1682 | if (bio_data_dir(cell->holder) == WRITE) | |
1683 | detail->any_writes = true; | |
1684 | ||
1685 | while ((bio = bio_list_pop(&cell->bios))) { | |
1686 | if (discard_or_flush(bio)) { | |
1687 | bio_list_add(&detail->unhandled_bios, bio); | |
1688 | continue; | |
1689 | } | |
1690 | ||
1691 | if (bio_data_dir(bio) == WRITE) | |
1692 | detail->any_writes = true; | |
1693 | ||
1694 | bio_list_add(&detail->bios_for_issue, bio); | |
1695 | inc_ds(cache, bio, cell); | |
1696 | } | |
1697 | } | |
1698 | ||
1699 | // FIXME: refactor these two | |
1700 | static void remap_cell_to_origin_clear_discard(struct cache *cache, | |
1701 | struct dm_bio_prison_cell *cell, | |
1702 | dm_oblock_t oblock, bool issue_holder) | |
1703 | { | |
1704 | struct bio *bio; | |
1705 | unsigned long flags; | |
1706 | struct inc_detail detail; | |
1707 | ||
1708 | detail.cache = cache; | |
1709 | bio_list_init(&detail.bios_for_issue); | |
1710 | bio_list_init(&detail.unhandled_bios); | |
1711 | detail.any_writes = false; | |
1712 | ||
1713 | spin_lock_irqsave(&cache->lock, flags); | |
1714 | dm_cell_visit_release(cache->prison, inc_fn, &detail, cell); | |
1715 | bio_list_merge(&cache->deferred_bios, &detail.unhandled_bios); | |
1716 | spin_unlock_irqrestore(&cache->lock, flags); | |
1717 | ||
1718 | remap_to_origin(cache, cell->holder); | |
1719 | if (issue_holder) | |
1720 | issue(cache, cell->holder); | |
1721 | else | |
1722 | accounted_begin(cache, cell->holder); | |
1723 | ||
1724 | if (detail.any_writes) | |
1725 | clear_discard(cache, oblock_to_dblock(cache, oblock)); | |
1726 | ||
1727 | while ((bio = bio_list_pop(&detail.bios_for_issue))) { | |
1728 | remap_to_origin(cache, bio); | |
1729 | issue(cache, bio); | |
1730 | } | |
9153df74 JT |
1731 | |
1732 | free_prison_cell(cache, cell); | |
651f5fa2 JT |
1733 | } |
1734 | ||
1735 | static void remap_cell_to_cache_dirty(struct cache *cache, struct dm_bio_prison_cell *cell, | |
1736 | dm_oblock_t oblock, dm_cblock_t cblock, bool issue_holder) | |
1737 | { | |
1738 | struct bio *bio; | |
1739 | unsigned long flags; | |
1740 | struct inc_detail detail; | |
1741 | ||
1742 | detail.cache = cache; | |
1743 | bio_list_init(&detail.bios_for_issue); | |
1744 | bio_list_init(&detail.unhandled_bios); | |
1745 | detail.any_writes = false; | |
1746 | ||
1747 | spin_lock_irqsave(&cache->lock, flags); | |
1748 | dm_cell_visit_release(cache->prison, inc_fn, &detail, cell); | |
1749 | bio_list_merge(&cache->deferred_bios, &detail.unhandled_bios); | |
1750 | spin_unlock_irqrestore(&cache->lock, flags); | |
1751 | ||
1752 | remap_to_cache(cache, cell->holder, cblock); | |
1753 | if (issue_holder) | |
1754 | issue(cache, cell->holder); | |
1755 | else | |
1756 | accounted_begin(cache, cell->holder); | |
1757 | ||
1758 | if (detail.any_writes) { | |
1759 | set_dirty(cache, oblock, cblock); | |
1760 | clear_discard(cache, oblock_to_dblock(cache, oblock)); | |
1761 | } | |
1762 | ||
1763 | while ((bio = bio_list_pop(&detail.bios_for_issue))) { | |
1764 | remap_to_cache(cache, bio, cblock); | |
1765 | issue(cache, bio); | |
1766 | } | |
9153df74 JT |
1767 | |
1768 | free_prison_cell(cache, cell); | |
651f5fa2 JT |
1769 | } |
1770 | ||
1771 | /*----------------------------------------------------------------*/ | |
1772 | ||
fb4100ae JT |
1773 | struct old_oblock_lock { |
1774 | struct policy_locker locker; | |
1775 | struct cache *cache; | |
1776 | struct prealloc *structs; | |
1777 | struct dm_bio_prison_cell *cell; | |
1778 | }; | |
1779 | ||
1780 | static int null_locker(struct policy_locker *locker, dm_oblock_t b) | |
1781 | { | |
1782 | /* This should never be called */ | |
1783 | BUG(); | |
1784 | return 0; | |
1785 | } | |
1786 | ||
1787 | static int cell_locker(struct policy_locker *locker, dm_oblock_t b) | |
1788 | { | |
1789 | struct old_oblock_lock *l = container_of(locker, struct old_oblock_lock, locker); | |
1790 | struct dm_bio_prison_cell *cell_prealloc = prealloc_get_cell(l->structs); | |
1791 | ||
1792 | return bio_detain(l->cache, b, NULL, cell_prealloc, | |
1793 | (cell_free_fn) prealloc_put_cell, | |
1794 | l->structs, &l->cell); | |
1795 | } | |
1796 | ||
651f5fa2 JT |
1797 | static void process_cell(struct cache *cache, struct prealloc *structs, |
1798 | struct dm_bio_prison_cell *new_ocell) | |
c6b4fcba JT |
1799 | { |
1800 | int r; | |
1801 | bool release_cell = true; | |
651f5fa2 | 1802 | struct bio *bio = new_ocell->holder; |
c6b4fcba | 1803 | dm_oblock_t block = get_bio_block(cache, bio); |
c6b4fcba | 1804 | struct policy_result lookup_result; |
2ee57d58 | 1805 | bool passthrough = passthrough_mode(&cache->features); |
40775257 | 1806 | bool fast_promotion, can_migrate; |
fb4100ae | 1807 | struct old_oblock_lock ool; |
c6b4fcba | 1808 | |
40775257 JT |
1809 | fast_promotion = is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio); |
1810 | can_migrate = !passthrough && (fast_promotion || spare_migration_bandwidth(cache)); | |
43c32bf2 | 1811 | |
fb4100ae JT |
1812 | ool.locker.fn = cell_locker; |
1813 | ool.cache = cache; | |
1814 | ool.structs = structs; | |
1815 | ool.cell = NULL; | |
40775257 | 1816 | r = policy_map(cache->policy, block, true, can_migrate, fast_promotion, |
fb4100ae | 1817 | bio, &ool.locker, &lookup_result); |
c6b4fcba JT |
1818 | |
1819 | if (r == -EWOULDBLOCK) | |
1820 | /* migration has been denied */ | |
1821 | lookup_result.op = POLICY_MISS; | |
1822 | ||
1823 | switch (lookup_result.op) { | |
1824 | case POLICY_HIT: | |
2ee57d58 JT |
1825 | if (passthrough) { |
1826 | inc_miss_counter(cache, bio); | |
c6b4fcba | 1827 | |
2ee57d58 JT |
1828 | /* |
1829 | * Passthrough always maps to the origin, | |
1830 | * invalidating any cache blocks that are written | |
1831 | * to. | |
1832 | */ | |
1833 | ||
1834 | if (bio_data_dir(bio) == WRITE) { | |
1835 | atomic_inc(&cache->stats.demotion); | |
1836 | invalidate(cache, structs, block, lookup_result.cblock, new_ocell); | |
1837 | release_cell = false; | |
1838 | ||
1839 | } else { | |
1840 | /* FIXME: factor out issue_origin() */ | |
2ee57d58 | 1841 | remap_to_origin_clear_discard(cache, bio, block); |
8c081b52 | 1842 | inc_and_issue(cache, bio, new_ocell); |
2ee57d58 JT |
1843 | } |
1844 | } else { | |
1845 | inc_hit_counter(cache, bio); | |
1846 | ||
1847 | if (bio_data_dir(bio) == WRITE && | |
1848 | writethrough_mode(&cache->features) && | |
1849 | !is_dirty(cache, lookup_result.cblock)) { | |
2ee57d58 | 1850 | remap_to_origin_then_cache(cache, bio, block, lookup_result.cblock); |
8c081b52 JT |
1851 | inc_and_issue(cache, bio, new_ocell); |
1852 | ||
651f5fa2 JT |
1853 | } else { |
1854 | remap_cell_to_cache_dirty(cache, new_ocell, block, lookup_result.cblock, true); | |
1855 | release_cell = false; | |
8c081b52 | 1856 | } |
2ee57d58 | 1857 | } |
c6b4fcba | 1858 | |
c6b4fcba JT |
1859 | break; |
1860 | ||
1861 | case POLICY_MISS: | |
1862 | inc_miss_counter(cache, bio); | |
651f5fa2 JT |
1863 | remap_cell_to_origin_clear_discard(cache, new_ocell, block, true); |
1864 | release_cell = false; | |
c6b4fcba JT |
1865 | break; |
1866 | ||
1867 | case POLICY_NEW: | |
1868 | atomic_inc(&cache->stats.promotion); | |
1869 | promote(cache, structs, block, lookup_result.cblock, new_ocell); | |
1870 | release_cell = false; | |
1871 | break; | |
1872 | ||
1873 | case POLICY_REPLACE: | |
c6b4fcba JT |
1874 | atomic_inc(&cache->stats.demotion); |
1875 | atomic_inc(&cache->stats.promotion); | |
c6b4fcba JT |
1876 | demote_then_promote(cache, structs, lookup_result.old_oblock, |
1877 | block, lookup_result.cblock, | |
fb4100ae | 1878 | ool.cell, new_ocell); |
c6b4fcba JT |
1879 | release_cell = false; |
1880 | break; | |
1881 | ||
1882 | default: | |
b61d9509 MS |
1883 | DMERR_LIMIT("%s: %s: erroring bio, unknown policy op: %u", |
1884 | cache_device_name(cache), __func__, | |
c6b4fcba JT |
1885 | (unsigned) lookup_result.op); |
1886 | bio_io_error(bio); | |
1887 | } | |
1888 | ||
1889 | if (release_cell) | |
1890 | cell_defer(cache, new_ocell, false); | |
1891 | } | |
1892 | ||
651f5fa2 JT |
1893 | static void process_bio(struct cache *cache, struct prealloc *structs, |
1894 | struct bio *bio) | |
1895 | { | |
1896 | int r; | |
1897 | dm_oblock_t block = get_bio_block(cache, bio); | |
1898 | struct dm_bio_prison_cell *cell_prealloc, *new_ocell; | |
1899 | ||
1900 | /* | |
1901 | * Check to see if that block is currently migrating. | |
1902 | */ | |
1903 | cell_prealloc = prealloc_get_cell(structs); | |
1904 | r = bio_detain(cache, block, bio, cell_prealloc, | |
1905 | (cell_free_fn) prealloc_put_cell, | |
1906 | structs, &new_ocell); | |
1907 | if (r > 0) | |
1908 | return; | |
1909 | ||
1910 | process_cell(cache, structs, new_ocell); | |
1911 | } | |
1912 | ||
c6b4fcba JT |
1913 | static int need_commit_due_to_time(struct cache *cache) |
1914 | { | |
651f5fa2 JT |
1915 | return jiffies < cache->last_commit_jiffies || |
1916 | jiffies > cache->last_commit_jiffies + COMMIT_PERIOD; | |
c6b4fcba JT |
1917 | } |
1918 | ||
028ae9f7 JT |
1919 | /* |
1920 | * A non-zero return indicates read_only or fail_io mode. | |
1921 | */ | |
1922 | static int commit(struct cache *cache, bool clean_shutdown) | |
1923 | { | |
1924 | int r; | |
1925 | ||
1926 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
1927 | return -EINVAL; | |
1928 | ||
1929 | atomic_inc(&cache->stats.commit_count); | |
1930 | r = dm_cache_commit(cache->cmd, clean_shutdown); | |
1931 | if (r) | |
1932 | metadata_operation_failed(cache, "dm_cache_commit", r); | |
1933 | ||
1934 | return r; | |
1935 | } | |
1936 | ||
c6b4fcba JT |
1937 | static int commit_if_needed(struct cache *cache) |
1938 | { | |
ffcbcb67 HM |
1939 | int r = 0; |
1940 | ||
1941 | if ((cache->commit_requested || need_commit_due_to_time(cache)) && | |
1942 | dm_cache_changed_this_transaction(cache->cmd)) { | |
028ae9f7 | 1943 | r = commit(cache, false); |
c6b4fcba | 1944 | cache->commit_requested = false; |
ffcbcb67 | 1945 | cache->last_commit_jiffies = jiffies; |
c6b4fcba JT |
1946 | } |
1947 | ||
ffcbcb67 | 1948 | return r; |
c6b4fcba JT |
1949 | } |
1950 | ||
1951 | static void process_deferred_bios(struct cache *cache) | |
1952 | { | |
665022d7 | 1953 | bool prealloc_used = false; |
c6b4fcba JT |
1954 | unsigned long flags; |
1955 | struct bio_list bios; | |
1956 | struct bio *bio; | |
1957 | struct prealloc structs; | |
1958 | ||
1959 | memset(&structs, 0, sizeof(structs)); | |
1960 | bio_list_init(&bios); | |
1961 | ||
1962 | spin_lock_irqsave(&cache->lock, flags); | |
1963 | bio_list_merge(&bios, &cache->deferred_bios); | |
1964 | bio_list_init(&cache->deferred_bios); | |
1965 | spin_unlock_irqrestore(&cache->lock, flags); | |
1966 | ||
1967 | while (!bio_list_empty(&bios)) { | |
1968 | /* | |
1969 | * If we've got no free migration structs, and processing | |
1970 | * this bio might require one, we pause until there are some | |
1971 | * prepared mappings to process. | |
1972 | */ | |
795e633a | 1973 | prealloc_used = true; |
c6b4fcba JT |
1974 | if (prealloc_data_structs(cache, &structs)) { |
1975 | spin_lock_irqsave(&cache->lock, flags); | |
1976 | bio_list_merge(&cache->deferred_bios, &bios); | |
1977 | spin_unlock_irqrestore(&cache->lock, flags); | |
1978 | break; | |
1979 | } | |
1980 | ||
1981 | bio = bio_list_pop(&bios); | |
1982 | ||
1eff9d32 | 1983 | if (bio->bi_opf & REQ_PREFLUSH) |
c6b4fcba | 1984 | process_flush_bio(cache, bio); |
e6047149 | 1985 | else if (bio_op(bio) == REQ_OP_DISCARD) |
7ae34e77 | 1986 | process_discard_bio(cache, &structs, bio); |
c6b4fcba JT |
1987 | else |
1988 | process_bio(cache, &structs, bio); | |
1989 | } | |
1990 | ||
665022d7 MS |
1991 | if (prealloc_used) |
1992 | prealloc_free_structs(cache, &structs); | |
c6b4fcba JT |
1993 | } |
1994 | ||
651f5fa2 JT |
1995 | static void process_deferred_cells(struct cache *cache) |
1996 | { | |
665022d7 | 1997 | bool prealloc_used = false; |
651f5fa2 JT |
1998 | unsigned long flags; |
1999 | struct dm_bio_prison_cell *cell, *tmp; | |
2000 | struct list_head cells; | |
2001 | struct prealloc structs; | |
2002 | ||
2003 | memset(&structs, 0, sizeof(structs)); | |
2004 | ||
2005 | INIT_LIST_HEAD(&cells); | |
2006 | ||
2007 | spin_lock_irqsave(&cache->lock, flags); | |
2008 | list_splice_init(&cache->deferred_cells, &cells); | |
2009 | spin_unlock_irqrestore(&cache->lock, flags); | |
2010 | ||
2011 | list_for_each_entry_safe(cell, tmp, &cells, user_list) { | |
2012 | /* | |
2013 | * If we've got no free migration structs, and processing | |
2014 | * this bio might require one, we pause until there are some | |
2015 | * prepared mappings to process. | |
2016 | */ | |
795e633a | 2017 | prealloc_used = true; |
651f5fa2 JT |
2018 | if (prealloc_data_structs(cache, &structs)) { |
2019 | spin_lock_irqsave(&cache->lock, flags); | |
2020 | list_splice(&cells, &cache->deferred_cells); | |
2021 | spin_unlock_irqrestore(&cache->lock, flags); | |
2022 | break; | |
2023 | } | |
2024 | ||
2025 | process_cell(cache, &structs, cell); | |
2026 | } | |
2027 | ||
665022d7 MS |
2028 | if (prealloc_used) |
2029 | prealloc_free_structs(cache, &structs); | |
651f5fa2 JT |
2030 | } |
2031 | ||
c6b4fcba JT |
2032 | static void process_deferred_flush_bios(struct cache *cache, bool submit_bios) |
2033 | { | |
2034 | unsigned long flags; | |
2035 | struct bio_list bios; | |
2036 | struct bio *bio; | |
2037 | ||
2038 | bio_list_init(&bios); | |
2039 | ||
2040 | spin_lock_irqsave(&cache->lock, flags); | |
2041 | bio_list_merge(&bios, &cache->deferred_flush_bios); | |
2042 | bio_list_init(&cache->deferred_flush_bios); | |
2043 | spin_unlock_irqrestore(&cache->lock, flags); | |
2044 | ||
8c081b52 JT |
2045 | /* |
2046 | * These bios have already been through inc_ds() | |
2047 | */ | |
c6b4fcba | 2048 | while ((bio = bio_list_pop(&bios))) |
066dbaa3 | 2049 | submit_bios ? accounted_request(cache, bio) : bio_io_error(bio); |
c6b4fcba JT |
2050 | } |
2051 | ||
e2e74d61 JT |
2052 | static void process_deferred_writethrough_bios(struct cache *cache) |
2053 | { | |
2054 | unsigned long flags; | |
2055 | struct bio_list bios; | |
2056 | struct bio *bio; | |
2057 | ||
2058 | bio_list_init(&bios); | |
2059 | ||
2060 | spin_lock_irqsave(&cache->lock, flags); | |
2061 | bio_list_merge(&bios, &cache->deferred_writethrough_bios); | |
2062 | bio_list_init(&cache->deferred_writethrough_bios); | |
2063 | spin_unlock_irqrestore(&cache->lock, flags); | |
2064 | ||
8c081b52 JT |
2065 | /* |
2066 | * These bios have already been through inc_ds() | |
2067 | */ | |
e2e74d61 | 2068 | while ((bio = bio_list_pop(&bios))) |
066dbaa3 | 2069 | accounted_request(cache, bio); |
e2e74d61 JT |
2070 | } |
2071 | ||
c6b4fcba JT |
2072 | static void writeback_some_dirty_blocks(struct cache *cache) |
2073 | { | |
665022d7 | 2074 | bool prealloc_used = false; |
c6b4fcba JT |
2075 | dm_oblock_t oblock; |
2076 | dm_cblock_t cblock; | |
2077 | struct prealloc structs; | |
2078 | struct dm_bio_prison_cell *old_ocell; | |
20f6814b | 2079 | bool busy = !iot_idle_for(&cache->origin_tracker, HZ); |
c6b4fcba JT |
2080 | |
2081 | memset(&structs, 0, sizeof(structs)); | |
2082 | ||
2083 | while (spare_migration_bandwidth(cache)) { | |
e782eff5 MS |
2084 | if (policy_writeback_work(cache->policy, &oblock, &cblock, busy)) |
2085 | break; /* no work to do */ | |
c6b4fcba | 2086 | |
795e633a | 2087 | prealloc_used = true; |
e782eff5 MS |
2088 | if (prealloc_data_structs(cache, &structs) || |
2089 | get_cell(cache, oblock, &structs, &old_ocell)) { | |
c6b4fcba JT |
2090 | policy_set_dirty(cache->policy, oblock); |
2091 | break; | |
2092 | } | |
2093 | ||
2094 | writeback(cache, &structs, oblock, cblock, old_ocell); | |
2095 | } | |
2096 | ||
665022d7 MS |
2097 | if (prealloc_used) |
2098 | prealloc_free_structs(cache, &structs); | |
c6b4fcba JT |
2099 | } |
2100 | ||
65790ff9 JT |
2101 | /*---------------------------------------------------------------- |
2102 | * Invalidations. | |
2103 | * Dropping something from the cache *without* writing back. | |
2104 | *--------------------------------------------------------------*/ | |
2105 | ||
2106 | static void process_invalidation_request(struct cache *cache, struct invalidation_request *req) | |
2107 | { | |
2108 | int r = 0; | |
2109 | uint64_t begin = from_cblock(req->cblocks->begin); | |
2110 | uint64_t end = from_cblock(req->cblocks->end); | |
2111 | ||
2112 | while (begin != end) { | |
2113 | r = policy_remove_cblock(cache->policy, to_cblock(begin)); | |
2114 | if (!r) { | |
2115 | r = dm_cache_remove_mapping(cache->cmd, to_cblock(begin)); | |
028ae9f7 JT |
2116 | if (r) { |
2117 | metadata_operation_failed(cache, "dm_cache_remove_mapping", r); | |
65790ff9 | 2118 | break; |
028ae9f7 | 2119 | } |
65790ff9 JT |
2120 | |
2121 | } else if (r == -ENODATA) { | |
2122 | /* harmless, already unmapped */ | |
2123 | r = 0; | |
2124 | ||
2125 | } else { | |
b61d9509 | 2126 | DMERR("%s: policy_remove_cblock failed", cache_device_name(cache)); |
65790ff9 JT |
2127 | break; |
2128 | } | |
2129 | ||
2130 | begin++; | |
2131 | } | |
2132 | ||
2133 | cache->commit_requested = true; | |
2134 | ||
2135 | req->err = r; | |
2136 | atomic_set(&req->complete, 1); | |
2137 | ||
2138 | wake_up(&req->result_wait); | |
2139 | } | |
2140 | ||
2141 | static void process_invalidation_requests(struct cache *cache) | |
2142 | { | |
2143 | struct list_head list; | |
2144 | struct invalidation_request *req, *tmp; | |
2145 | ||
2146 | INIT_LIST_HEAD(&list); | |
2147 | spin_lock(&cache->invalidation_lock); | |
2148 | list_splice_init(&cache->invalidation_requests, &list); | |
2149 | spin_unlock(&cache->invalidation_lock); | |
2150 | ||
2151 | list_for_each_entry_safe (req, tmp, &list, list) | |
2152 | process_invalidation_request(cache, req); | |
2153 | } | |
2154 | ||
c6b4fcba JT |
2155 | /*---------------------------------------------------------------- |
2156 | * Main worker loop | |
2157 | *--------------------------------------------------------------*/ | |
66cb1910 | 2158 | static bool is_quiescing(struct cache *cache) |
c6b4fcba | 2159 | { |
238f8363 | 2160 | return atomic_read(&cache->quiescing); |
c6b4fcba JT |
2161 | } |
2162 | ||
66cb1910 JT |
2163 | static void ack_quiescing(struct cache *cache) |
2164 | { | |
2165 | if (is_quiescing(cache)) { | |
2166 | atomic_inc(&cache->quiescing_ack); | |
2167 | wake_up(&cache->quiescing_wait); | |
2168 | } | |
2169 | } | |
2170 | ||
2171 | static void wait_for_quiescing_ack(struct cache *cache) | |
2172 | { | |
2173 | wait_event(cache->quiescing_wait, atomic_read(&cache->quiescing_ack)); | |
2174 | } | |
2175 | ||
2176 | static void start_quiescing(struct cache *cache) | |
c6b4fcba | 2177 | { |
238f8363 | 2178 | atomic_inc(&cache->quiescing); |
66cb1910 | 2179 | wait_for_quiescing_ack(cache); |
c6b4fcba JT |
2180 | } |
2181 | ||
66cb1910 | 2182 | static void stop_quiescing(struct cache *cache) |
c6b4fcba | 2183 | { |
238f8363 | 2184 | atomic_set(&cache->quiescing, 0); |
66cb1910 | 2185 | atomic_set(&cache->quiescing_ack, 0); |
c6b4fcba JT |
2186 | } |
2187 | ||
2188 | static void wait_for_migrations(struct cache *cache) | |
2189 | { | |
a59db676 | 2190 | wait_event(cache->migration_wait, !atomic_read(&cache->nr_allocated_migrations)); |
c6b4fcba JT |
2191 | } |
2192 | ||
2193 | static void stop_worker(struct cache *cache) | |
2194 | { | |
2195 | cancel_delayed_work(&cache->waker); | |
2196 | flush_workqueue(cache->wq); | |
2197 | } | |
2198 | ||
651f5fa2 JT |
2199 | static void requeue_deferred_cells(struct cache *cache) |
2200 | { | |
2201 | unsigned long flags; | |
2202 | struct list_head cells; | |
2203 | struct dm_bio_prison_cell *cell, *tmp; | |
2204 | ||
2205 | INIT_LIST_HEAD(&cells); | |
2206 | spin_lock_irqsave(&cache->lock, flags); | |
2207 | list_splice_init(&cache->deferred_cells, &cells); | |
2208 | spin_unlock_irqrestore(&cache->lock, flags); | |
2209 | ||
2210 | list_for_each_entry_safe(cell, tmp, &cells, user_list) | |
2211 | cell_requeue(cache, cell); | |
2212 | } | |
2213 | ||
2214 | static void requeue_deferred_bios(struct cache *cache) | |
c6b4fcba JT |
2215 | { |
2216 | struct bio *bio; | |
2217 | struct bio_list bios; | |
2218 | ||
2219 | bio_list_init(&bios); | |
2220 | bio_list_merge(&bios, &cache->deferred_bios); | |
2221 | bio_list_init(&cache->deferred_bios); | |
2222 | ||
4246a0b6 CH |
2223 | while ((bio = bio_list_pop(&bios))) { |
2224 | bio->bi_error = DM_ENDIO_REQUEUE; | |
2225 | bio_endio(bio); | |
2226 | } | |
c6b4fcba JT |
2227 | } |
2228 | ||
2229 | static int more_work(struct cache *cache) | |
2230 | { | |
2231 | if (is_quiescing(cache)) | |
2232 | return !list_empty(&cache->quiesced_migrations) || | |
2233 | !list_empty(&cache->completed_migrations) || | |
2234 | !list_empty(&cache->need_commit_migrations); | |
2235 | else | |
2236 | return !bio_list_empty(&cache->deferred_bios) || | |
651f5fa2 | 2237 | !list_empty(&cache->deferred_cells) || |
c6b4fcba | 2238 | !bio_list_empty(&cache->deferred_flush_bios) || |
e2e74d61 | 2239 | !bio_list_empty(&cache->deferred_writethrough_bios) || |
c6b4fcba JT |
2240 | !list_empty(&cache->quiesced_migrations) || |
2241 | !list_empty(&cache->completed_migrations) || | |
65790ff9 JT |
2242 | !list_empty(&cache->need_commit_migrations) || |
2243 | cache->invalidate; | |
c6b4fcba JT |
2244 | } |
2245 | ||
2246 | static void do_worker(struct work_struct *ws) | |
2247 | { | |
2248 | struct cache *cache = container_of(ws, struct cache, worker); | |
2249 | ||
2250 | do { | |
66cb1910 JT |
2251 | if (!is_quiescing(cache)) { |
2252 | writeback_some_dirty_blocks(cache); | |
2253 | process_deferred_writethrough_bios(cache); | |
c6b4fcba | 2254 | process_deferred_bios(cache); |
651f5fa2 | 2255 | process_deferred_cells(cache); |
65790ff9 | 2256 | process_invalidation_requests(cache); |
66cb1910 | 2257 | } |
c6b4fcba | 2258 | |
7ae34e77 | 2259 | process_migrations(cache, &cache->quiesced_migrations, issue_copy_or_discard); |
c6b4fcba JT |
2260 | process_migrations(cache, &cache->completed_migrations, complete_migration); |
2261 | ||
c6b4fcba JT |
2262 | if (commit_if_needed(cache)) { |
2263 | process_deferred_flush_bios(cache, false); | |
304affaa | 2264 | process_migrations(cache, &cache->need_commit_migrations, migration_failure); |
c6b4fcba JT |
2265 | } else { |
2266 | process_deferred_flush_bios(cache, true); | |
2267 | process_migrations(cache, &cache->need_commit_migrations, | |
2268 | migration_success_post_commit); | |
2269 | } | |
66cb1910 JT |
2270 | |
2271 | ack_quiescing(cache); | |
2272 | ||
c6b4fcba JT |
2273 | } while (more_work(cache)); |
2274 | } | |
2275 | ||
2276 | /* | |
2277 | * We want to commit periodically so that not too much | |
2278 | * unwritten metadata builds up. | |
2279 | */ | |
2280 | static void do_waker(struct work_struct *ws) | |
2281 | { | |
2282 | struct cache *cache = container_of(to_delayed_work(ws), struct cache, waker); | |
fba10109 | 2283 | policy_tick(cache->policy, true); |
c6b4fcba JT |
2284 | wake_worker(cache); |
2285 | queue_delayed_work(cache->wq, &cache->waker, COMMIT_PERIOD); | |
2286 | } | |
2287 | ||
2288 | /*----------------------------------------------------------------*/ | |
2289 | ||
2290 | static int is_congested(struct dm_dev *dev, int bdi_bits) | |
2291 | { | |
2292 | struct request_queue *q = bdev_get_queue(dev->bdev); | |
2293 | return bdi_congested(&q->backing_dev_info, bdi_bits); | |
2294 | } | |
2295 | ||
2296 | static int cache_is_congested(struct dm_target_callbacks *cb, int bdi_bits) | |
2297 | { | |
2298 | struct cache *cache = container_of(cb, struct cache, callbacks); | |
2299 | ||
2300 | return is_congested(cache->origin_dev, bdi_bits) || | |
2301 | is_congested(cache->cache_dev, bdi_bits); | |
2302 | } | |
2303 | ||
2304 | /*---------------------------------------------------------------- | |
2305 | * Target methods | |
2306 | *--------------------------------------------------------------*/ | |
2307 | ||
2308 | /* | |
2309 | * This function gets called on the error paths of the constructor, so we | |
2310 | * have to cope with a partially initialised struct. | |
2311 | */ | |
2312 | static void destroy(struct cache *cache) | |
2313 | { | |
2314 | unsigned i; | |
2315 | ||
6f65985e | 2316 | mempool_destroy(cache->migration_pool); |
c6b4fcba JT |
2317 | |
2318 | if (cache->all_io_ds) | |
2319 | dm_deferred_set_destroy(cache->all_io_ds); | |
2320 | ||
2321 | if (cache->prison) | |
2322 | dm_bio_prison_destroy(cache->prison); | |
2323 | ||
2324 | if (cache->wq) | |
2325 | destroy_workqueue(cache->wq); | |
2326 | ||
2327 | if (cache->dirty_bitset) | |
2328 | free_bitset(cache->dirty_bitset); | |
2329 | ||
2330 | if (cache->discard_bitset) | |
2331 | free_bitset(cache->discard_bitset); | |
2332 | ||
2333 | if (cache->copier) | |
2334 | dm_kcopyd_client_destroy(cache->copier); | |
2335 | ||
2336 | if (cache->cmd) | |
2337 | dm_cache_metadata_close(cache->cmd); | |
2338 | ||
2339 | if (cache->metadata_dev) | |
2340 | dm_put_device(cache->ti, cache->metadata_dev); | |
2341 | ||
2342 | if (cache->origin_dev) | |
2343 | dm_put_device(cache->ti, cache->origin_dev); | |
2344 | ||
2345 | if (cache->cache_dev) | |
2346 | dm_put_device(cache->ti, cache->cache_dev); | |
2347 | ||
2348 | if (cache->policy) | |
2349 | dm_cache_policy_destroy(cache->policy); | |
2350 | ||
2351 | for (i = 0; i < cache->nr_ctr_args ; i++) | |
2352 | kfree(cache->ctr_args[i]); | |
2353 | kfree(cache->ctr_args); | |
2354 | ||
2355 | kfree(cache); | |
2356 | } | |
2357 | ||
2358 | static void cache_dtr(struct dm_target *ti) | |
2359 | { | |
2360 | struct cache *cache = ti->private; | |
2361 | ||
2362 | destroy(cache); | |
2363 | } | |
2364 | ||
2365 | static sector_t get_dev_size(struct dm_dev *dev) | |
2366 | { | |
2367 | return i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; | |
2368 | } | |
2369 | ||
2370 | /*----------------------------------------------------------------*/ | |
2371 | ||
2372 | /* | |
2373 | * Construct a cache device mapping. | |
2374 | * | |
2375 | * cache <metadata dev> <cache dev> <origin dev> <block size> | |
2376 | * <#feature args> [<feature arg>]* | |
2377 | * <policy> <#policy args> [<policy arg>]* | |
2378 | * | |
2379 | * metadata dev : fast device holding the persistent metadata | |
2380 | * cache dev : fast device holding cached data blocks | |
2381 | * origin dev : slow device holding original data blocks | |
2382 | * block size : cache unit size in sectors | |
2383 | * | |
2384 | * #feature args : number of feature arguments passed | |
2385 | * feature args : writethrough. (The default is writeback.) | |
2386 | * | |
2387 | * policy : the replacement policy to use | |
2388 | * #policy args : an even number of policy arguments corresponding | |
2389 | * to key/value pairs passed to the policy | |
2390 | * policy args : key/value pairs passed to the policy | |
2391 | * E.g. 'sequential_threshold 1024' | |
2392 | * See cache-policies.txt for details. | |
2393 | * | |
2394 | * Optional feature arguments are: | |
2395 | * writethrough : write through caching that prohibits cache block | |
2396 | * content from being different from origin block content. | |
2397 | * Without this argument, the default behaviour is to write | |
2398 | * back cache block contents later for performance reasons, | |
2399 | * so they may differ from the corresponding origin blocks. | |
2400 | */ | |
2401 | struct cache_args { | |
2402 | struct dm_target *ti; | |
2403 | ||
2404 | struct dm_dev *metadata_dev; | |
2405 | ||
2406 | struct dm_dev *cache_dev; | |
2407 | sector_t cache_sectors; | |
2408 | ||
2409 | struct dm_dev *origin_dev; | |
2410 | sector_t origin_sectors; | |
2411 | ||
2412 | uint32_t block_size; | |
2413 | ||
2414 | const char *policy_name; | |
2415 | int policy_argc; | |
2416 | const char **policy_argv; | |
2417 | ||
2418 | struct cache_features features; | |
2419 | }; | |
2420 | ||
2421 | static void destroy_cache_args(struct cache_args *ca) | |
2422 | { | |
2423 | if (ca->metadata_dev) | |
2424 | dm_put_device(ca->ti, ca->metadata_dev); | |
2425 | ||
2426 | if (ca->cache_dev) | |
2427 | dm_put_device(ca->ti, ca->cache_dev); | |
2428 | ||
2429 | if (ca->origin_dev) | |
2430 | dm_put_device(ca->ti, ca->origin_dev); | |
2431 | ||
2432 | kfree(ca); | |
2433 | } | |
2434 | ||
2435 | static bool at_least_one_arg(struct dm_arg_set *as, char **error) | |
2436 | { | |
2437 | if (!as->argc) { | |
2438 | *error = "Insufficient args"; | |
2439 | return false; | |
2440 | } | |
2441 | ||
2442 | return true; | |
2443 | } | |
2444 | ||
2445 | static int parse_metadata_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2446 | char **error) | |
2447 | { | |
2448 | int r; | |
2449 | sector_t metadata_dev_size; | |
2450 | char b[BDEVNAME_SIZE]; | |
2451 | ||
2452 | if (!at_least_one_arg(as, error)) | |
2453 | return -EINVAL; | |
2454 | ||
2455 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2456 | &ca->metadata_dev); | |
2457 | if (r) { | |
2458 | *error = "Error opening metadata device"; | |
2459 | return r; | |
2460 | } | |
2461 | ||
2462 | metadata_dev_size = get_dev_size(ca->metadata_dev); | |
2463 | if (metadata_dev_size > DM_CACHE_METADATA_MAX_SECTORS_WARNING) | |
2464 | DMWARN("Metadata device %s is larger than %u sectors: excess space will not be used.", | |
2465 | bdevname(ca->metadata_dev->bdev, b), THIN_METADATA_MAX_SECTORS); | |
2466 | ||
2467 | return 0; | |
2468 | } | |
2469 | ||
2470 | static int parse_cache_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2471 | char **error) | |
2472 | { | |
2473 | int r; | |
2474 | ||
2475 | if (!at_least_one_arg(as, error)) | |
2476 | return -EINVAL; | |
2477 | ||
2478 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2479 | &ca->cache_dev); | |
2480 | if (r) { | |
2481 | *error = "Error opening cache device"; | |
2482 | return r; | |
2483 | } | |
2484 | ca->cache_sectors = get_dev_size(ca->cache_dev); | |
2485 | ||
2486 | return 0; | |
2487 | } | |
2488 | ||
2489 | static int parse_origin_dev(struct cache_args *ca, struct dm_arg_set *as, | |
2490 | char **error) | |
2491 | { | |
2492 | int r; | |
2493 | ||
2494 | if (!at_least_one_arg(as, error)) | |
2495 | return -EINVAL; | |
2496 | ||
2497 | r = dm_get_device(ca->ti, dm_shift_arg(as), FMODE_READ | FMODE_WRITE, | |
2498 | &ca->origin_dev); | |
2499 | if (r) { | |
2500 | *error = "Error opening origin device"; | |
2501 | return r; | |
2502 | } | |
2503 | ||
2504 | ca->origin_sectors = get_dev_size(ca->origin_dev); | |
2505 | if (ca->ti->len > ca->origin_sectors) { | |
2506 | *error = "Device size larger than cached device"; | |
2507 | return -EINVAL; | |
2508 | } | |
2509 | ||
2510 | return 0; | |
2511 | } | |
2512 | ||
2513 | static int parse_block_size(struct cache_args *ca, struct dm_arg_set *as, | |
2514 | char **error) | |
2515 | { | |
05473044 | 2516 | unsigned long block_size; |
c6b4fcba JT |
2517 | |
2518 | if (!at_least_one_arg(as, error)) | |
2519 | return -EINVAL; | |
2520 | ||
05473044 MS |
2521 | if (kstrtoul(dm_shift_arg(as), 10, &block_size) || !block_size || |
2522 | block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS || | |
2523 | block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS || | |
2524 | block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) { | |
c6b4fcba JT |
2525 | *error = "Invalid data block size"; |
2526 | return -EINVAL; | |
2527 | } | |
2528 | ||
05473044 | 2529 | if (block_size > ca->cache_sectors) { |
c6b4fcba JT |
2530 | *error = "Data block size is larger than the cache device"; |
2531 | return -EINVAL; | |
2532 | } | |
2533 | ||
05473044 | 2534 | ca->block_size = block_size; |
c6b4fcba JT |
2535 | |
2536 | return 0; | |
2537 | } | |
2538 | ||
2539 | static void init_features(struct cache_features *cf) | |
2540 | { | |
2541 | cf->mode = CM_WRITE; | |
2ee57d58 | 2542 | cf->io_mode = CM_IO_WRITEBACK; |
c6b4fcba JT |
2543 | } |
2544 | ||
2545 | static int parse_features(struct cache_args *ca, struct dm_arg_set *as, | |
2546 | char **error) | |
2547 | { | |
2548 | static struct dm_arg _args[] = { | |
2549 | {0, 1, "Invalid number of cache feature arguments"}, | |
2550 | }; | |
2551 | ||
2552 | int r; | |
2553 | unsigned argc; | |
2554 | const char *arg; | |
2555 | struct cache_features *cf = &ca->features; | |
2556 | ||
2557 | init_features(cf); | |
2558 | ||
2559 | r = dm_read_arg_group(_args, as, &argc, error); | |
2560 | if (r) | |
2561 | return -EINVAL; | |
2562 | ||
2563 | while (argc--) { | |
2564 | arg = dm_shift_arg(as); | |
2565 | ||
2566 | if (!strcasecmp(arg, "writeback")) | |
2ee57d58 | 2567 | cf->io_mode = CM_IO_WRITEBACK; |
c6b4fcba JT |
2568 | |
2569 | else if (!strcasecmp(arg, "writethrough")) | |
2ee57d58 JT |
2570 | cf->io_mode = CM_IO_WRITETHROUGH; |
2571 | ||
2572 | else if (!strcasecmp(arg, "passthrough")) | |
2573 | cf->io_mode = CM_IO_PASSTHROUGH; | |
c6b4fcba JT |
2574 | |
2575 | else { | |
2576 | *error = "Unrecognised cache feature requested"; | |
2577 | return -EINVAL; | |
2578 | } | |
2579 | } | |
2580 | ||
2581 | return 0; | |
2582 | } | |
2583 | ||
2584 | static int parse_policy(struct cache_args *ca, struct dm_arg_set *as, | |
2585 | char **error) | |
2586 | { | |
2587 | static struct dm_arg _args[] = { | |
2588 | {0, 1024, "Invalid number of policy arguments"}, | |
2589 | }; | |
2590 | ||
2591 | int r; | |
2592 | ||
2593 | if (!at_least_one_arg(as, error)) | |
2594 | return -EINVAL; | |
2595 | ||
2596 | ca->policy_name = dm_shift_arg(as); | |
2597 | ||
2598 | r = dm_read_arg_group(_args, as, &ca->policy_argc, error); | |
2599 | if (r) | |
2600 | return -EINVAL; | |
2601 | ||
2602 | ca->policy_argv = (const char **)as->argv; | |
2603 | dm_consume_args(as, ca->policy_argc); | |
2604 | ||
2605 | return 0; | |
2606 | } | |
2607 | ||
2608 | static int parse_cache_args(struct cache_args *ca, int argc, char **argv, | |
2609 | char **error) | |
2610 | { | |
2611 | int r; | |
2612 | struct dm_arg_set as; | |
2613 | ||
2614 | as.argc = argc; | |
2615 | as.argv = argv; | |
2616 | ||
2617 | r = parse_metadata_dev(ca, &as, error); | |
2618 | if (r) | |
2619 | return r; | |
2620 | ||
2621 | r = parse_cache_dev(ca, &as, error); | |
2622 | if (r) | |
2623 | return r; | |
2624 | ||
2625 | r = parse_origin_dev(ca, &as, error); | |
2626 | if (r) | |
2627 | return r; | |
2628 | ||
2629 | r = parse_block_size(ca, &as, error); | |
2630 | if (r) | |
2631 | return r; | |
2632 | ||
2633 | r = parse_features(ca, &as, error); | |
2634 | if (r) | |
2635 | return r; | |
2636 | ||
2637 | r = parse_policy(ca, &as, error); | |
2638 | if (r) | |
2639 | return r; | |
2640 | ||
2641 | return 0; | |
2642 | } | |
2643 | ||
2644 | /*----------------------------------------------------------------*/ | |
2645 | ||
2646 | static struct kmem_cache *migration_cache; | |
2647 | ||
2c73c471 AK |
2648 | #define NOT_CORE_OPTION 1 |
2649 | ||
2f14f4b5 | 2650 | static int process_config_option(struct cache *cache, const char *key, const char *value) |
2c73c471 AK |
2651 | { |
2652 | unsigned long tmp; | |
2653 | ||
2f14f4b5 JT |
2654 | if (!strcasecmp(key, "migration_threshold")) { |
2655 | if (kstrtoul(value, 10, &tmp)) | |
2c73c471 AK |
2656 | return -EINVAL; |
2657 | ||
2658 | cache->migration_threshold = tmp; | |
2659 | return 0; | |
2660 | } | |
2661 | ||
2662 | return NOT_CORE_OPTION; | |
2663 | } | |
2664 | ||
2f14f4b5 JT |
2665 | static int set_config_value(struct cache *cache, const char *key, const char *value) |
2666 | { | |
2667 | int r = process_config_option(cache, key, value); | |
2668 | ||
2669 | if (r == NOT_CORE_OPTION) | |
2670 | r = policy_set_config_value(cache->policy, key, value); | |
2671 | ||
2672 | if (r) | |
2673 | DMWARN("bad config value for %s: %s", key, value); | |
2674 | ||
2675 | return r; | |
2676 | } | |
2677 | ||
2678 | static int set_config_values(struct cache *cache, int argc, const char **argv) | |
c6b4fcba JT |
2679 | { |
2680 | int r = 0; | |
2681 | ||
2682 | if (argc & 1) { | |
2683 | DMWARN("Odd number of policy arguments given but they should be <key> <value> pairs."); | |
2684 | return -EINVAL; | |
2685 | } | |
2686 | ||
2687 | while (argc) { | |
2f14f4b5 JT |
2688 | r = set_config_value(cache, argv[0], argv[1]); |
2689 | if (r) | |
2690 | break; | |
c6b4fcba JT |
2691 | |
2692 | argc -= 2; | |
2693 | argv += 2; | |
2694 | } | |
2695 | ||
2696 | return r; | |
2697 | } | |
2698 | ||
2699 | static int create_cache_policy(struct cache *cache, struct cache_args *ca, | |
2700 | char **error) | |
2701 | { | |
4cb3e1db MP |
2702 | struct dm_cache_policy *p = dm_cache_policy_create(ca->policy_name, |
2703 | cache->cache_size, | |
2704 | cache->origin_sectors, | |
2705 | cache->sectors_per_block); | |
2706 | if (IS_ERR(p)) { | |
c6b4fcba | 2707 | *error = "Error creating cache's policy"; |
4cb3e1db | 2708 | return PTR_ERR(p); |
c6b4fcba | 2709 | } |
4cb3e1db | 2710 | cache->policy = p; |
c6b4fcba | 2711 | |
2f14f4b5 | 2712 | return 0; |
c6b4fcba JT |
2713 | } |
2714 | ||
08b18451 | 2715 | /* |
2bb812df JT |
2716 | * We want the discard block size to be at least the size of the cache |
2717 | * block size and have no more than 2^14 discard blocks across the origin. | |
08b18451 JT |
2718 | */ |
2719 | #define MAX_DISCARD_BLOCKS (1 << 14) | |
2720 | ||
2721 | static bool too_many_discard_blocks(sector_t discard_block_size, | |
2722 | sector_t origin_size) | |
2723 | { | |
2724 | (void) sector_div(origin_size, discard_block_size); | |
2725 | ||
2726 | return origin_size > MAX_DISCARD_BLOCKS; | |
2727 | } | |
2728 | ||
2729 | static sector_t calculate_discard_block_size(sector_t cache_block_size, | |
2730 | sector_t origin_size) | |
2731 | { | |
2bb812df | 2732 | sector_t discard_block_size = cache_block_size; |
08b18451 JT |
2733 | |
2734 | if (origin_size) | |
2735 | while (too_many_discard_blocks(discard_block_size, origin_size)) | |
2736 | discard_block_size *= 2; | |
2737 | ||
2738 | return discard_block_size; | |
2739 | } | |
2740 | ||
d1d9220c JT |
2741 | static void set_cache_size(struct cache *cache, dm_cblock_t size) |
2742 | { | |
2743 | dm_block_t nr_blocks = from_cblock(size); | |
2744 | ||
2745 | if (nr_blocks > (1 << 20) && cache->cache_size != size) | |
2746 | DMWARN_LIMIT("You have created a cache device with a lot of individual cache blocks (%llu)\n" | |
2747 | "All these mappings can consume a lot of kernel memory, and take some time to read/write.\n" | |
2748 | "Please consider increasing the cache block size to reduce the overall cache block count.", | |
2749 | (unsigned long long) nr_blocks); | |
2750 | ||
2751 | cache->cache_size = size; | |
2752 | } | |
2753 | ||
f8350daf | 2754 | #define DEFAULT_MIGRATION_THRESHOLD 2048 |
c6b4fcba | 2755 | |
c6b4fcba JT |
2756 | static int cache_create(struct cache_args *ca, struct cache **result) |
2757 | { | |
2758 | int r = 0; | |
2759 | char **error = &ca->ti->error; | |
2760 | struct cache *cache; | |
2761 | struct dm_target *ti = ca->ti; | |
2762 | dm_block_t origin_blocks; | |
2763 | struct dm_cache_metadata *cmd; | |
2764 | bool may_format = ca->features.mode == CM_WRITE; | |
2765 | ||
2766 | cache = kzalloc(sizeof(*cache), GFP_KERNEL); | |
2767 | if (!cache) | |
2768 | return -ENOMEM; | |
2769 | ||
2770 | cache->ti = ca->ti; | |
2771 | ti->private = cache; | |
c6b4fcba JT |
2772 | ti->num_flush_bios = 2; |
2773 | ti->flush_supported = true; | |
2774 | ||
2775 | ti->num_discard_bios = 1; | |
2776 | ti->discards_supported = true; | |
2777 | ti->discard_zeroes_data_unsupported = true; | |
2572629a | 2778 | ti->split_discard_bios = false; |
c6b4fcba | 2779 | |
8c5008fa | 2780 | cache->features = ca->features; |
30187e1d | 2781 | ti->per_io_data_size = get_per_bio_data_size(cache); |
c6b4fcba | 2782 | |
c6b4fcba JT |
2783 | cache->callbacks.congested_fn = cache_is_congested; |
2784 | dm_table_add_target_callbacks(ti->table, &cache->callbacks); | |
2785 | ||
2786 | cache->metadata_dev = ca->metadata_dev; | |
2787 | cache->origin_dev = ca->origin_dev; | |
2788 | cache->cache_dev = ca->cache_dev; | |
2789 | ||
2790 | ca->metadata_dev = ca->origin_dev = ca->cache_dev = NULL; | |
2791 | ||
2792 | /* FIXME: factor out this whole section */ | |
2793 | origin_blocks = cache->origin_sectors = ca->origin_sectors; | |
414dd67d | 2794 | origin_blocks = block_div(origin_blocks, ca->block_size); |
c6b4fcba JT |
2795 | cache->origin_blocks = to_oblock(origin_blocks); |
2796 | ||
2797 | cache->sectors_per_block = ca->block_size; | |
2798 | if (dm_set_target_max_io_len(ti, cache->sectors_per_block)) { | |
2799 | r = -EINVAL; | |
2800 | goto bad; | |
2801 | } | |
2802 | ||
2803 | if (ca->block_size & (ca->block_size - 1)) { | |
2804 | dm_block_t cache_size = ca->cache_sectors; | |
2805 | ||
2806 | cache->sectors_per_block_shift = -1; | |
414dd67d | 2807 | cache_size = block_div(cache_size, ca->block_size); |
d1d9220c | 2808 | set_cache_size(cache, to_cblock(cache_size)); |
c6b4fcba JT |
2809 | } else { |
2810 | cache->sectors_per_block_shift = __ffs(ca->block_size); | |
d1d9220c | 2811 | set_cache_size(cache, to_cblock(ca->cache_sectors >> cache->sectors_per_block_shift)); |
c6b4fcba JT |
2812 | } |
2813 | ||
2814 | r = create_cache_policy(cache, ca, error); | |
2815 | if (r) | |
2816 | goto bad; | |
2f14f4b5 | 2817 | |
c6b4fcba | 2818 | cache->policy_nr_args = ca->policy_argc; |
2f14f4b5 JT |
2819 | cache->migration_threshold = DEFAULT_MIGRATION_THRESHOLD; |
2820 | ||
2821 | r = set_config_values(cache, ca->policy_argc, ca->policy_argv); | |
2822 | if (r) { | |
2823 | *error = "Error setting cache policy's config values"; | |
2824 | goto bad; | |
2825 | } | |
c6b4fcba JT |
2826 | |
2827 | cmd = dm_cache_metadata_open(cache->metadata_dev->bdev, | |
2828 | ca->block_size, may_format, | |
2829 | dm_cache_policy_get_hint_size(cache->policy)); | |
2830 | if (IS_ERR(cmd)) { | |
2831 | *error = "Error creating metadata object"; | |
2832 | r = PTR_ERR(cmd); | |
2833 | goto bad; | |
2834 | } | |
2835 | cache->cmd = cmd; | |
028ae9f7 JT |
2836 | set_cache_mode(cache, CM_WRITE); |
2837 | if (get_cache_mode(cache) != CM_WRITE) { | |
2838 | *error = "Unable to get write access to metadata, please check/repair metadata."; | |
2839 | r = -EINVAL; | |
2840 | goto bad; | |
2841 | } | |
c6b4fcba | 2842 | |
2ee57d58 JT |
2843 | if (passthrough_mode(&cache->features)) { |
2844 | bool all_clean; | |
2845 | ||
2846 | r = dm_cache_metadata_all_clean(cache->cmd, &all_clean); | |
2847 | if (r) { | |
2848 | *error = "dm_cache_metadata_all_clean() failed"; | |
2849 | goto bad; | |
2850 | } | |
2851 | ||
2852 | if (!all_clean) { | |
2853 | *error = "Cannot enter passthrough mode unless all blocks are clean"; | |
2854 | r = -EINVAL; | |
2855 | goto bad; | |
2856 | } | |
2857 | } | |
2858 | ||
c6b4fcba | 2859 | spin_lock_init(&cache->lock); |
651f5fa2 | 2860 | INIT_LIST_HEAD(&cache->deferred_cells); |
c6b4fcba JT |
2861 | bio_list_init(&cache->deferred_bios); |
2862 | bio_list_init(&cache->deferred_flush_bios); | |
e2e74d61 | 2863 | bio_list_init(&cache->deferred_writethrough_bios); |
c6b4fcba JT |
2864 | INIT_LIST_HEAD(&cache->quiesced_migrations); |
2865 | INIT_LIST_HEAD(&cache->completed_migrations); | |
2866 | INIT_LIST_HEAD(&cache->need_commit_migrations); | |
a59db676 JT |
2867 | atomic_set(&cache->nr_allocated_migrations, 0); |
2868 | atomic_set(&cache->nr_io_migrations, 0); | |
c6b4fcba JT |
2869 | init_waitqueue_head(&cache->migration_wait); |
2870 | ||
66cb1910 | 2871 | init_waitqueue_head(&cache->quiescing_wait); |
238f8363 | 2872 | atomic_set(&cache->quiescing, 0); |
66cb1910 JT |
2873 | atomic_set(&cache->quiescing_ack, 0); |
2874 | ||
fa4d683a | 2875 | r = -ENOMEM; |
44fa816b | 2876 | atomic_set(&cache->nr_dirty, 0); |
c6b4fcba JT |
2877 | cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size)); |
2878 | if (!cache->dirty_bitset) { | |
2879 | *error = "could not allocate dirty bitset"; | |
2880 | goto bad; | |
2881 | } | |
2882 | clear_bitset(cache->dirty_bitset, from_cblock(cache->cache_size)); | |
2883 | ||
08b18451 JT |
2884 | cache->discard_block_size = |
2885 | calculate_discard_block_size(cache->sectors_per_block, | |
2886 | cache->origin_sectors); | |
2572629a JT |
2887 | cache->discard_nr_blocks = to_dblock(dm_sector_div_up(cache->origin_sectors, |
2888 | cache->discard_block_size)); | |
1bad9bc4 | 2889 | cache->discard_bitset = alloc_bitset(from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2890 | if (!cache->discard_bitset) { |
2891 | *error = "could not allocate discard bitset"; | |
2892 | goto bad; | |
2893 | } | |
1bad9bc4 | 2894 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); |
c6b4fcba JT |
2895 | |
2896 | cache->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle); | |
2897 | if (IS_ERR(cache->copier)) { | |
2898 | *error = "could not create kcopyd client"; | |
2899 | r = PTR_ERR(cache->copier); | |
2900 | goto bad; | |
2901 | } | |
2902 | ||
2903 | cache->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); | |
2904 | if (!cache->wq) { | |
2905 | *error = "could not create workqueue for metadata object"; | |
2906 | goto bad; | |
2907 | } | |
2908 | INIT_WORK(&cache->worker, do_worker); | |
2909 | INIT_DELAYED_WORK(&cache->waker, do_waker); | |
2910 | cache->last_commit_jiffies = jiffies; | |
2911 | ||
a195db2d | 2912 | cache->prison = dm_bio_prison_create(); |
c6b4fcba JT |
2913 | if (!cache->prison) { |
2914 | *error = "could not create bio prison"; | |
2915 | goto bad; | |
2916 | } | |
2917 | ||
2918 | cache->all_io_ds = dm_deferred_set_create(); | |
2919 | if (!cache->all_io_ds) { | |
2920 | *error = "could not create all_io deferred set"; | |
2921 | goto bad; | |
2922 | } | |
2923 | ||
2924 | cache->migration_pool = mempool_create_slab_pool(MIGRATION_POOL_SIZE, | |
2925 | migration_cache); | |
2926 | if (!cache->migration_pool) { | |
2927 | *error = "Error creating cache's migration mempool"; | |
2928 | goto bad; | |
2929 | } | |
2930 | ||
c6b4fcba JT |
2931 | cache->need_tick_bio = true; |
2932 | cache->sized = false; | |
65790ff9 | 2933 | cache->invalidate = false; |
c6b4fcba JT |
2934 | cache->commit_requested = false; |
2935 | cache->loaded_mappings = false; | |
2936 | cache->loaded_discards = false; | |
2937 | ||
2938 | load_stats(cache); | |
2939 | ||
2940 | atomic_set(&cache->stats.demotion, 0); | |
2941 | atomic_set(&cache->stats.promotion, 0); | |
2942 | atomic_set(&cache->stats.copies_avoided, 0); | |
2943 | atomic_set(&cache->stats.cache_cell_clash, 0); | |
2944 | atomic_set(&cache->stats.commit_count, 0); | |
2945 | atomic_set(&cache->stats.discard_count, 0); | |
2946 | ||
65790ff9 JT |
2947 | spin_lock_init(&cache->invalidation_lock); |
2948 | INIT_LIST_HEAD(&cache->invalidation_requests); | |
2949 | ||
066dbaa3 JT |
2950 | iot_init(&cache->origin_tracker); |
2951 | ||
c6b4fcba JT |
2952 | *result = cache; |
2953 | return 0; | |
2954 | ||
2955 | bad: | |
2956 | destroy(cache); | |
2957 | return r; | |
2958 | } | |
2959 | ||
2960 | static int copy_ctr_args(struct cache *cache, int argc, const char **argv) | |
2961 | { | |
2962 | unsigned i; | |
2963 | const char **copy; | |
2964 | ||
2965 | copy = kcalloc(argc, sizeof(*copy), GFP_KERNEL); | |
2966 | if (!copy) | |
2967 | return -ENOMEM; | |
2968 | for (i = 0; i < argc; i++) { | |
2969 | copy[i] = kstrdup(argv[i], GFP_KERNEL); | |
2970 | if (!copy[i]) { | |
2971 | while (i--) | |
2972 | kfree(copy[i]); | |
2973 | kfree(copy); | |
2974 | return -ENOMEM; | |
2975 | } | |
2976 | } | |
2977 | ||
2978 | cache->nr_ctr_args = argc; | |
2979 | cache->ctr_args = copy; | |
2980 | ||
2981 | return 0; | |
2982 | } | |
2983 | ||
2984 | static int cache_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
2985 | { | |
2986 | int r = -EINVAL; | |
2987 | struct cache_args *ca; | |
2988 | struct cache *cache = NULL; | |
2989 | ||
2990 | ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
2991 | if (!ca) { | |
2992 | ti->error = "Error allocating memory for cache"; | |
2993 | return -ENOMEM; | |
2994 | } | |
2995 | ca->ti = ti; | |
2996 | ||
2997 | r = parse_cache_args(ca, argc, argv, &ti->error); | |
2998 | if (r) | |
2999 | goto out; | |
3000 | ||
3001 | r = cache_create(ca, &cache); | |
617a0b89 HM |
3002 | if (r) |
3003 | goto out; | |
c6b4fcba JT |
3004 | |
3005 | r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3); | |
3006 | if (r) { | |
3007 | destroy(cache); | |
3008 | goto out; | |
3009 | } | |
3010 | ||
3011 | ti->private = cache; | |
3012 | ||
3013 | out: | |
3014 | destroy_cache_args(ca); | |
3015 | return r; | |
3016 | } | |
3017 | ||
651f5fa2 JT |
3018 | /*----------------------------------------------------------------*/ |
3019 | ||
3020 | static int cache_map(struct dm_target *ti, struct bio *bio) | |
c6b4fcba | 3021 | { |
651f5fa2 JT |
3022 | struct cache *cache = ti->private; |
3023 | ||
c6b4fcba | 3024 | int r; |
651f5fa2 | 3025 | struct dm_bio_prison_cell *cell = NULL; |
c6b4fcba | 3026 | dm_oblock_t block = get_bio_block(cache, bio); |
19b0092e | 3027 | size_t pb_data_size = get_per_bio_data_size(cache); |
c6b4fcba | 3028 | bool can_migrate = false; |
40775257 | 3029 | bool fast_promotion; |
c6b4fcba | 3030 | struct policy_result lookup_result; |
e893fba9 | 3031 | struct per_bio_data *pb = init_per_bio_data(bio, pb_data_size); |
fb4100ae JT |
3032 | struct old_oblock_lock ool; |
3033 | ||
3034 | ool.locker.fn = null_locker; | |
c6b4fcba | 3035 | |
e893fba9 | 3036 | if (unlikely(from_oblock(block) >= from_oblock(cache->origin_blocks))) { |
c6b4fcba JT |
3037 | /* |
3038 | * This can only occur if the io goes to a partial block at | |
3039 | * the end of the origin device. We don't cache these. | |
3040 | * Just remap to the origin and carry on. | |
3041 | */ | |
e893fba9 | 3042 | remap_to_origin(cache, bio); |
651f5fa2 | 3043 | accounted_begin(cache, bio); |
c6b4fcba JT |
3044 | return DM_MAPIO_REMAPPED; |
3045 | } | |
3046 | ||
651f5fa2 | 3047 | if (discard_or_flush(bio)) { |
c6b4fcba JT |
3048 | defer_bio(cache, bio); |
3049 | return DM_MAPIO_SUBMITTED; | |
3050 | } | |
3051 | ||
3052 | /* | |
3053 | * Check to see if that block is currently migrating. | |
3054 | */ | |
651f5fa2 JT |
3055 | cell = alloc_prison_cell(cache); |
3056 | if (!cell) { | |
c6b4fcba JT |
3057 | defer_bio(cache, bio); |
3058 | return DM_MAPIO_SUBMITTED; | |
3059 | } | |
3060 | ||
651f5fa2 | 3061 | r = bio_detain(cache, block, bio, cell, |
c6b4fcba | 3062 | (cell_free_fn) free_prison_cell, |
651f5fa2 | 3063 | cache, &cell); |
c6b4fcba JT |
3064 | if (r) { |
3065 | if (r < 0) | |
3066 | defer_bio(cache, bio); | |
3067 | ||
3068 | return DM_MAPIO_SUBMITTED; | |
3069 | } | |
3070 | ||
40775257 | 3071 | fast_promotion = is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio); |
c6b4fcba | 3072 | |
40775257 | 3073 | r = policy_map(cache->policy, block, false, can_migrate, fast_promotion, |
fb4100ae | 3074 | bio, &ool.locker, &lookup_result); |
c6b4fcba | 3075 | if (r == -EWOULDBLOCK) { |
651f5fa2 | 3076 | cell_defer(cache, cell, true); |
c6b4fcba JT |
3077 | return DM_MAPIO_SUBMITTED; |
3078 | ||
3079 | } else if (r) { | |
b61d9509 MS |
3080 | DMERR_LIMIT("%s: Unexpected return from cache replacement policy: %d", |
3081 | cache_device_name(cache), r); | |
651f5fa2 | 3082 | cell_defer(cache, cell, false); |
c6b4fcba JT |
3083 | bio_io_error(bio); |
3084 | return DM_MAPIO_SUBMITTED; | |
3085 | } | |
3086 | ||
2ee57d58 | 3087 | r = DM_MAPIO_REMAPPED; |
c6b4fcba JT |
3088 | switch (lookup_result.op) { |
3089 | case POLICY_HIT: | |
2ee57d58 JT |
3090 | if (passthrough_mode(&cache->features)) { |
3091 | if (bio_data_dir(bio) == WRITE) { | |
3092 | /* | |
3093 | * We need to invalidate this block, so | |
3094 | * defer for the worker thread. | |
3095 | */ | |
651f5fa2 | 3096 | cell_defer(cache, cell, true); |
2ee57d58 JT |
3097 | r = DM_MAPIO_SUBMITTED; |
3098 | ||
3099 | } else { | |
2ee57d58 JT |
3100 | inc_miss_counter(cache, bio); |
3101 | remap_to_origin_clear_discard(cache, bio, block); | |
651f5fa2 JT |
3102 | accounted_begin(cache, bio); |
3103 | inc_ds(cache, bio, cell); | |
3104 | // FIXME: we want to remap hits or misses straight | |
3105 | // away rather than passing over to the worker. | |
3106 | cell_defer(cache, cell, false); | |
2ee57d58 | 3107 | } |
c6b4fcba | 3108 | |
2ee57d58 JT |
3109 | } else { |
3110 | inc_hit_counter(cache, bio); | |
2ee57d58 | 3111 | if (bio_data_dir(bio) == WRITE && writethrough_mode(&cache->features) && |
651f5fa2 | 3112 | !is_dirty(cache, lookup_result.cblock)) { |
2ee57d58 | 3113 | remap_to_origin_then_cache(cache, bio, block, lookup_result.cblock); |
651f5fa2 JT |
3114 | accounted_begin(cache, bio); |
3115 | inc_ds(cache, bio, cell); | |
3116 | cell_defer(cache, cell, false); | |
3117 | ||
3118 | } else | |
3119 | remap_cell_to_cache_dirty(cache, cell, block, lookup_result.cblock, false); | |
2ee57d58 | 3120 | } |
c6b4fcba JT |
3121 | break; |
3122 | ||
3123 | case POLICY_MISS: | |
3124 | inc_miss_counter(cache, bio); | |
c6b4fcba JT |
3125 | if (pb->req_nr != 0) { |
3126 | /* | |
3127 | * This is a duplicate writethrough io that is no | |
3128 | * longer needed because the block has been demoted. | |
3129 | */ | |
4246a0b6 | 3130 | bio_endio(bio); |
651f5fa2 JT |
3131 | // FIXME: remap everything as a miss |
3132 | cell_defer(cache, cell, false); | |
8c081b52 JT |
3133 | r = DM_MAPIO_SUBMITTED; |
3134 | ||
3135 | } else | |
651f5fa2 | 3136 | remap_cell_to_origin_clear_discard(cache, cell, block, false); |
c6b4fcba JT |
3137 | break; |
3138 | ||
3139 | default: | |
b61d9509 MS |
3140 | DMERR_LIMIT("%s: %s: erroring bio: unknown policy op: %u", |
3141 | cache_device_name(cache), __func__, | |
c6b4fcba | 3142 | (unsigned) lookup_result.op); |
651f5fa2 | 3143 | cell_defer(cache, cell, false); |
c6b4fcba | 3144 | bio_io_error(bio); |
2ee57d58 | 3145 | r = DM_MAPIO_SUBMITTED; |
c6b4fcba JT |
3146 | } |
3147 | ||
2ee57d58 | 3148 | return r; |
c6b4fcba JT |
3149 | } |
3150 | ||
3151 | static int cache_end_io(struct dm_target *ti, struct bio *bio, int error) | |
3152 | { | |
3153 | struct cache *cache = ti->private; | |
3154 | unsigned long flags; | |
19b0092e MS |
3155 | size_t pb_data_size = get_per_bio_data_size(cache); |
3156 | struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); | |
c6b4fcba JT |
3157 | |
3158 | if (pb->tick) { | |
fba10109 | 3159 | policy_tick(cache->policy, false); |
c6b4fcba JT |
3160 | |
3161 | spin_lock_irqsave(&cache->lock, flags); | |
3162 | cache->need_tick_bio = true; | |
3163 | spin_unlock_irqrestore(&cache->lock, flags); | |
3164 | } | |
3165 | ||
3166 | check_for_quiesced_migrations(cache, pb); | |
066dbaa3 | 3167 | accounted_complete(cache, bio); |
c6b4fcba JT |
3168 | |
3169 | return 0; | |
3170 | } | |
3171 | ||
3172 | static int write_dirty_bitset(struct cache *cache) | |
3173 | { | |
3174 | unsigned i, r; | |
3175 | ||
028ae9f7 JT |
3176 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
3177 | return -EINVAL; | |
3178 | ||
c6b4fcba JT |
3179 | for (i = 0; i < from_cblock(cache->cache_size); i++) { |
3180 | r = dm_cache_set_dirty(cache->cmd, to_cblock(i), | |
3181 | is_dirty(cache, to_cblock(i))); | |
028ae9f7 JT |
3182 | if (r) { |
3183 | metadata_operation_failed(cache, "dm_cache_set_dirty", r); | |
c6b4fcba | 3184 | return r; |
028ae9f7 | 3185 | } |
c6b4fcba JT |
3186 | } |
3187 | ||
3188 | return 0; | |
3189 | } | |
3190 | ||
3191 | static int write_discard_bitset(struct cache *cache) | |
3192 | { | |
3193 | unsigned i, r; | |
3194 | ||
028ae9f7 JT |
3195 | if (get_cache_mode(cache) >= CM_READ_ONLY) |
3196 | return -EINVAL; | |
3197 | ||
1bad9bc4 JT |
3198 | r = dm_cache_discard_bitset_resize(cache->cmd, cache->discard_block_size, |
3199 | cache->discard_nr_blocks); | |
c6b4fcba | 3200 | if (r) { |
b61d9509 | 3201 | DMERR("%s: could not resize on-disk discard bitset", cache_device_name(cache)); |
028ae9f7 | 3202 | metadata_operation_failed(cache, "dm_cache_discard_bitset_resize", r); |
c6b4fcba JT |
3203 | return r; |
3204 | } | |
3205 | ||
1bad9bc4 JT |
3206 | for (i = 0; i < from_dblock(cache->discard_nr_blocks); i++) { |
3207 | r = dm_cache_set_discard(cache->cmd, to_dblock(i), | |
3208 | is_discarded(cache, to_dblock(i))); | |
028ae9f7 JT |
3209 | if (r) { |
3210 | metadata_operation_failed(cache, "dm_cache_set_discard", r); | |
c6b4fcba | 3211 | return r; |
028ae9f7 JT |
3212 | } |
3213 | } | |
3214 | ||
3215 | return 0; | |
3216 | } | |
3217 | ||
3218 | static int write_hints(struct cache *cache) | |
3219 | { | |
3220 | int r; | |
3221 | ||
3222 | if (get_cache_mode(cache) >= CM_READ_ONLY) | |
3223 | return -EINVAL; | |
3224 | ||
3225 | r = dm_cache_write_hints(cache->cmd, cache->policy); | |
3226 | if (r) { | |
3227 | metadata_operation_failed(cache, "dm_cache_write_hints", r); | |
3228 | return r; | |
c6b4fcba JT |
3229 | } |
3230 | ||
3231 | return 0; | |
3232 | } | |
3233 | ||
c6b4fcba JT |
3234 | /* |
3235 | * returns true on success | |
3236 | */ | |
3237 | static bool sync_metadata(struct cache *cache) | |
3238 | { | |
3239 | int r1, r2, r3, r4; | |
3240 | ||
3241 | r1 = write_dirty_bitset(cache); | |
3242 | if (r1) | |
b61d9509 | 3243 | DMERR("%s: could not write dirty bitset", cache_device_name(cache)); |
c6b4fcba JT |
3244 | |
3245 | r2 = write_discard_bitset(cache); | |
3246 | if (r2) | |
b61d9509 | 3247 | DMERR("%s: could not write discard bitset", cache_device_name(cache)); |
c6b4fcba JT |
3248 | |
3249 | save_stats(cache); | |
3250 | ||
028ae9f7 | 3251 | r3 = write_hints(cache); |
c6b4fcba | 3252 | if (r3) |
b61d9509 | 3253 | DMERR("%s: could not write hints", cache_device_name(cache)); |
c6b4fcba JT |
3254 | |
3255 | /* | |
3256 | * If writing the above metadata failed, we still commit, but don't | |
3257 | * set the clean shutdown flag. This will effectively force every | |
3258 | * dirty bit to be set on reload. | |
3259 | */ | |
028ae9f7 | 3260 | r4 = commit(cache, !r1 && !r2 && !r3); |
c6b4fcba | 3261 | if (r4) |
b61d9509 | 3262 | DMERR("%s: could not write cache metadata", cache_device_name(cache)); |
c6b4fcba JT |
3263 | |
3264 | return !r1 && !r2 && !r3 && !r4; | |
3265 | } | |
3266 | ||
3267 | static void cache_postsuspend(struct dm_target *ti) | |
3268 | { | |
3269 | struct cache *cache = ti->private; | |
3270 | ||
3271 | start_quiescing(cache); | |
3272 | wait_for_migrations(cache); | |
3273 | stop_worker(cache); | |
651f5fa2 JT |
3274 | requeue_deferred_bios(cache); |
3275 | requeue_deferred_cells(cache); | |
c6b4fcba JT |
3276 | stop_quiescing(cache); |
3277 | ||
028ae9f7 JT |
3278 | if (get_cache_mode(cache) == CM_WRITE) |
3279 | (void) sync_metadata(cache); | |
c6b4fcba JT |
3280 | } |
3281 | ||
3282 | static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock, | |
3283 | bool dirty, uint32_t hint, bool hint_valid) | |
3284 | { | |
3285 | int r; | |
3286 | struct cache *cache = context; | |
3287 | ||
3288 | r = policy_load_mapping(cache->policy, oblock, cblock, hint, hint_valid); | |
3289 | if (r) | |
3290 | return r; | |
3291 | ||
3292 | if (dirty) | |
3293 | set_dirty(cache, oblock, cblock); | |
3294 | else | |
3295 | clear_dirty(cache, oblock, cblock); | |
3296 | ||
3297 | return 0; | |
3298 | } | |
3299 | ||
3e2e1c30 JT |
3300 | /* |
3301 | * The discard block size in the on disk metadata is not | |
3302 | * neccessarily the same as we're currently using. So we have to | |
3303 | * be careful to only set the discarded attribute if we know it | |
3304 | * covers a complete block of the new size. | |
3305 | */ | |
3306 | struct discard_load_info { | |
3307 | struct cache *cache; | |
3308 | ||
3309 | /* | |
3310 | * These blocks are sized using the on disk dblock size, rather | |
3311 | * than the current one. | |
3312 | */ | |
3313 | dm_block_t block_size; | |
3314 | dm_block_t discard_begin, discard_end; | |
3315 | }; | |
3316 | ||
3317 | static void discard_load_info_init(struct cache *cache, | |
3318 | struct discard_load_info *li) | |
3319 | { | |
3320 | li->cache = cache; | |
3321 | li->discard_begin = li->discard_end = 0; | |
3322 | } | |
3323 | ||
3324 | static void set_discard_range(struct discard_load_info *li) | |
3325 | { | |
3326 | sector_t b, e; | |
3327 | ||
3328 | if (li->discard_begin == li->discard_end) | |
3329 | return; | |
3330 | ||
3331 | /* | |
3332 | * Convert to sectors. | |
3333 | */ | |
3334 | b = li->discard_begin * li->block_size; | |
3335 | e = li->discard_end * li->block_size; | |
3336 | ||
3337 | /* | |
3338 | * Then convert back to the current dblock size. | |
3339 | */ | |
3340 | b = dm_sector_div_up(b, li->cache->discard_block_size); | |
3341 | sector_div(e, li->cache->discard_block_size); | |
3342 | ||
3343 | /* | |
3344 | * The origin may have shrunk, so we need to check we're still in | |
3345 | * bounds. | |
3346 | */ | |
3347 | if (e > from_dblock(li->cache->discard_nr_blocks)) | |
3348 | e = from_dblock(li->cache->discard_nr_blocks); | |
3349 | ||
3350 | for (; b < e; b++) | |
3351 | set_discard(li->cache, to_dblock(b)); | |
3352 | } | |
3353 | ||
c6b4fcba | 3354 | static int load_discard(void *context, sector_t discard_block_size, |
1bad9bc4 | 3355 | dm_dblock_t dblock, bool discard) |
c6b4fcba | 3356 | { |
3e2e1c30 | 3357 | struct discard_load_info *li = context; |
c6b4fcba | 3358 | |
3e2e1c30 | 3359 | li->block_size = discard_block_size; |
1bad9bc4 | 3360 | |
3e2e1c30 JT |
3361 | if (discard) { |
3362 | if (from_dblock(dblock) == li->discard_end) | |
3363 | /* | |
3364 | * We're already in a discard range, just extend it. | |
3365 | */ | |
3366 | li->discard_end = li->discard_end + 1ULL; | |
3367 | ||
3368 | else { | |
3369 | /* | |
3370 | * Emit the old range and start a new one. | |
3371 | */ | |
3372 | set_discard_range(li); | |
3373 | li->discard_begin = from_dblock(dblock); | |
3374 | li->discard_end = li->discard_begin + 1ULL; | |
3375 | } | |
3376 | } else { | |
3377 | set_discard_range(li); | |
3378 | li->discard_begin = li->discard_end = 0; | |
3379 | } | |
c6b4fcba JT |
3380 | |
3381 | return 0; | |
3382 | } | |
3383 | ||
f494a9c6 JT |
3384 | static dm_cblock_t get_cache_dev_size(struct cache *cache) |
3385 | { | |
3386 | sector_t size = get_dev_size(cache->cache_dev); | |
3387 | (void) sector_div(size, cache->sectors_per_block); | |
3388 | return to_cblock(size); | |
3389 | } | |
3390 | ||
3391 | static bool can_resize(struct cache *cache, dm_cblock_t new_size) | |
3392 | { | |
3393 | if (from_cblock(new_size) > from_cblock(cache->cache_size)) | |
3394 | return true; | |
3395 | ||
3396 | /* | |
3397 | * We can't drop a dirty block when shrinking the cache. | |
3398 | */ | |
3399 | while (from_cblock(new_size) < from_cblock(cache->cache_size)) { | |
3400 | new_size = to_cblock(from_cblock(new_size) + 1); | |
3401 | if (is_dirty(cache, new_size)) { | |
b61d9509 MS |
3402 | DMERR("%s: unable to shrink cache; cache block %llu is dirty", |
3403 | cache_device_name(cache), | |
f494a9c6 JT |
3404 | (unsigned long long) from_cblock(new_size)); |
3405 | return false; | |
3406 | } | |
3407 | } | |
3408 | ||
3409 | return true; | |
3410 | } | |
3411 | ||
3412 | static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size) | |
3413 | { | |
3414 | int r; | |
3415 | ||
08844800 | 3416 | r = dm_cache_resize(cache->cmd, new_size); |
f494a9c6 | 3417 | if (r) { |
b61d9509 | 3418 | DMERR("%s: could not resize cache metadata", cache_device_name(cache)); |
028ae9f7 | 3419 | metadata_operation_failed(cache, "dm_cache_resize", r); |
f494a9c6 JT |
3420 | return r; |
3421 | } | |
3422 | ||
d1d9220c | 3423 | set_cache_size(cache, new_size); |
f494a9c6 JT |
3424 | |
3425 | return 0; | |
3426 | } | |
3427 | ||
c6b4fcba JT |
3428 | static int cache_preresume(struct dm_target *ti) |
3429 | { | |
3430 | int r = 0; | |
3431 | struct cache *cache = ti->private; | |
f494a9c6 | 3432 | dm_cblock_t csize = get_cache_dev_size(cache); |
c6b4fcba JT |
3433 | |
3434 | /* | |
3435 | * Check to see if the cache has resized. | |
3436 | */ | |
f494a9c6 JT |
3437 | if (!cache->sized) { |
3438 | r = resize_cache_dev(cache, csize); | |
3439 | if (r) | |
c6b4fcba | 3440 | return r; |
c6b4fcba JT |
3441 | |
3442 | cache->sized = true; | |
f494a9c6 JT |
3443 | |
3444 | } else if (csize != cache->cache_size) { | |
3445 | if (!can_resize(cache, csize)) | |
3446 | return -EINVAL; | |
3447 | ||
3448 | r = resize_cache_dev(cache, csize); | |
3449 | if (r) | |
3450 | return r; | |
c6b4fcba JT |
3451 | } |
3452 | ||
3453 | if (!cache->loaded_mappings) { | |
ea2dd8c1 | 3454 | r = dm_cache_load_mappings(cache->cmd, cache->policy, |
c6b4fcba JT |
3455 | load_mapping, cache); |
3456 | if (r) { | |
b61d9509 | 3457 | DMERR("%s: could not load cache mappings", cache_device_name(cache)); |
028ae9f7 | 3458 | metadata_operation_failed(cache, "dm_cache_load_mappings", r); |
c6b4fcba JT |
3459 | return r; |
3460 | } | |
3461 | ||
3462 | cache->loaded_mappings = true; | |
3463 | } | |
3464 | ||
3465 | if (!cache->loaded_discards) { | |
3e2e1c30 JT |
3466 | struct discard_load_info li; |
3467 | ||
3468 | /* | |
3469 | * The discard bitset could have been resized, or the | |
3470 | * discard block size changed. To be safe we start by | |
3471 | * setting every dblock to not discarded. | |
3472 | */ | |
3473 | clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); | |
3474 | ||
3475 | discard_load_info_init(cache, &li); | |
3476 | r = dm_cache_load_discards(cache->cmd, load_discard, &li); | |
c6b4fcba | 3477 | if (r) { |
b61d9509 | 3478 | DMERR("%s: could not load origin discards", cache_device_name(cache)); |
028ae9f7 | 3479 | metadata_operation_failed(cache, "dm_cache_load_discards", r); |
c6b4fcba JT |
3480 | return r; |
3481 | } | |
3e2e1c30 | 3482 | set_discard_range(&li); |
c6b4fcba JT |
3483 | |
3484 | cache->loaded_discards = true; | |
3485 | } | |
3486 | ||
3487 | return r; | |
3488 | } | |
3489 | ||
3490 | static void cache_resume(struct dm_target *ti) | |
3491 | { | |
3492 | struct cache *cache = ti->private; | |
3493 | ||
3494 | cache->need_tick_bio = true; | |
3495 | do_waker(&cache->waker.work); | |
3496 | } | |
3497 | ||
3498 | /* | |
3499 | * Status format: | |
3500 | * | |
6a388618 MS |
3501 | * <metadata block size> <#used metadata blocks>/<#total metadata blocks> |
3502 | * <cache block size> <#used cache blocks>/<#total cache blocks> | |
c6b4fcba | 3503 | * <#read hits> <#read misses> <#write hits> <#write misses> |
6a388618 | 3504 | * <#demotions> <#promotions> <#dirty> |
c6b4fcba JT |
3505 | * <#features> <features>* |
3506 | * <#core args> <core args> | |
255eac20 | 3507 | * <policy name> <#policy args> <policy args>* <cache metadata mode> <needs_check> |
c6b4fcba JT |
3508 | */ |
3509 | static void cache_status(struct dm_target *ti, status_type_t type, | |
3510 | unsigned status_flags, char *result, unsigned maxlen) | |
3511 | { | |
3512 | int r = 0; | |
3513 | unsigned i; | |
3514 | ssize_t sz = 0; | |
3515 | dm_block_t nr_free_blocks_metadata = 0; | |
3516 | dm_block_t nr_blocks_metadata = 0; | |
3517 | char buf[BDEVNAME_SIZE]; | |
3518 | struct cache *cache = ti->private; | |
3519 | dm_cblock_t residency; | |
d14fcf3d | 3520 | bool needs_check; |
c6b4fcba JT |
3521 | |
3522 | switch (type) { | |
3523 | case STATUSTYPE_INFO: | |
028ae9f7 JT |
3524 | if (get_cache_mode(cache) == CM_FAIL) { |
3525 | DMEMIT("Fail"); | |
3526 | break; | |
c6b4fcba JT |
3527 | } |
3528 | ||
028ae9f7 JT |
3529 | /* Commit to ensure statistics aren't out-of-date */ |
3530 | if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) | |
3531 | (void) commit(cache, false); | |
3532 | ||
b61d9509 | 3533 | r = dm_cache_get_free_metadata_block_count(cache->cmd, &nr_free_blocks_metadata); |
c6b4fcba | 3534 | if (r) { |
b61d9509 MS |
3535 | DMERR("%s: dm_cache_get_free_metadata_block_count returned %d", |
3536 | cache_device_name(cache), r); | |
c6b4fcba JT |
3537 | goto err; |
3538 | } | |
3539 | ||
3540 | r = dm_cache_get_metadata_dev_size(cache->cmd, &nr_blocks_metadata); | |
3541 | if (r) { | |
b61d9509 MS |
3542 | DMERR("%s: dm_cache_get_metadata_dev_size returned %d", |
3543 | cache_device_name(cache), r); | |
c6b4fcba JT |
3544 | goto err; |
3545 | } | |
3546 | ||
3547 | residency = policy_residency(cache->policy); | |
3548 | ||
44fa816b | 3549 | DMEMIT("%u %llu/%llu %u %llu/%llu %u %u %u %u %u %u %lu ", |
895b47d7 | 3550 | (unsigned)DM_CACHE_METADATA_BLOCK_SIZE, |
c6b4fcba JT |
3551 | (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), |
3552 | (unsigned long long)nr_blocks_metadata, | |
6a388618 MS |
3553 | cache->sectors_per_block, |
3554 | (unsigned long long) from_cblock(residency), | |
3555 | (unsigned long long) from_cblock(cache->cache_size), | |
c6b4fcba JT |
3556 | (unsigned) atomic_read(&cache->stats.read_hit), |
3557 | (unsigned) atomic_read(&cache->stats.read_miss), | |
3558 | (unsigned) atomic_read(&cache->stats.write_hit), | |
3559 | (unsigned) atomic_read(&cache->stats.write_miss), | |
3560 | (unsigned) atomic_read(&cache->stats.demotion), | |
3561 | (unsigned) atomic_read(&cache->stats.promotion), | |
44fa816b | 3562 | (unsigned long) atomic_read(&cache->nr_dirty)); |
c6b4fcba | 3563 | |
2ee57d58 | 3564 | if (writethrough_mode(&cache->features)) |
c6b4fcba | 3565 | DMEMIT("1 writethrough "); |
2ee57d58 JT |
3566 | |
3567 | else if (passthrough_mode(&cache->features)) | |
3568 | DMEMIT("1 passthrough "); | |
3569 | ||
3570 | else if (writeback_mode(&cache->features)) | |
3571 | DMEMIT("1 writeback "); | |
3572 | ||
3573 | else { | |
b61d9509 MS |
3574 | DMERR("%s: internal error: unknown io mode: %d", |
3575 | cache_device_name(cache), (int) cache->features.io_mode); | |
2ee57d58 JT |
3576 | goto err; |
3577 | } | |
c6b4fcba JT |
3578 | |
3579 | DMEMIT("2 migration_threshold %llu ", (unsigned long long) cache->migration_threshold); | |
2e68c4e6 MS |
3580 | |
3581 | DMEMIT("%s ", dm_cache_policy_get_name(cache->policy)); | |
c6b4fcba | 3582 | if (sz < maxlen) { |
028ae9f7 | 3583 | r = policy_emit_config_values(cache->policy, result, maxlen, &sz); |
c6b4fcba | 3584 | if (r) |
b61d9509 MS |
3585 | DMERR("%s: policy_emit_config_values returned %d", |
3586 | cache_device_name(cache), r); | |
c6b4fcba JT |
3587 | } |
3588 | ||
028ae9f7 JT |
3589 | if (get_cache_mode(cache) == CM_READ_ONLY) |
3590 | DMEMIT("ro "); | |
3591 | else | |
3592 | DMEMIT("rw "); | |
3593 | ||
d14fcf3d JT |
3594 | r = dm_cache_metadata_needs_check(cache->cmd, &needs_check); |
3595 | ||
3596 | if (r || needs_check) | |
255eac20 MS |
3597 | DMEMIT("needs_check "); |
3598 | else | |
3599 | DMEMIT("- "); | |
3600 | ||
c6b4fcba JT |
3601 | break; |
3602 | ||
3603 | case STATUSTYPE_TABLE: | |
3604 | format_dev_t(buf, cache->metadata_dev->bdev->bd_dev); | |
3605 | DMEMIT("%s ", buf); | |
3606 | format_dev_t(buf, cache->cache_dev->bdev->bd_dev); | |
3607 | DMEMIT("%s ", buf); | |
3608 | format_dev_t(buf, cache->origin_dev->bdev->bd_dev); | |
3609 | DMEMIT("%s", buf); | |
3610 | ||
3611 | for (i = 0; i < cache->nr_ctr_args - 1; i++) | |
3612 | DMEMIT(" %s", cache->ctr_args[i]); | |
3613 | if (cache->nr_ctr_args) | |
3614 | DMEMIT(" %s", cache->ctr_args[cache->nr_ctr_args - 1]); | |
3615 | } | |
3616 | ||
3617 | return; | |
3618 | ||
3619 | err: | |
3620 | DMEMIT("Error"); | |
3621 | } | |
3622 | ||
c6b4fcba | 3623 | /* |
65790ff9 JT |
3624 | * A cache block range can take two forms: |
3625 | * | |
3626 | * i) A single cblock, eg. '3456' | |
3627 | * ii) A begin and end cblock with dots between, eg. 123-234 | |
3628 | */ | |
3629 | static int parse_cblock_range(struct cache *cache, const char *str, | |
3630 | struct cblock_range *result) | |
3631 | { | |
3632 | char dummy; | |
3633 | uint64_t b, e; | |
3634 | int r; | |
3635 | ||
3636 | /* | |
3637 | * Try and parse form (ii) first. | |
3638 | */ | |
3639 | r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy); | |
3640 | if (r < 0) | |
3641 | return r; | |
3642 | ||
3643 | if (r == 2) { | |
3644 | result->begin = to_cblock(b); | |
3645 | result->end = to_cblock(e); | |
3646 | return 0; | |
3647 | } | |
3648 | ||
3649 | /* | |
3650 | * That didn't work, try form (i). | |
3651 | */ | |
3652 | r = sscanf(str, "%llu%c", &b, &dummy); | |
3653 | if (r < 0) | |
3654 | return r; | |
3655 | ||
3656 | if (r == 1) { | |
3657 | result->begin = to_cblock(b); | |
3658 | result->end = to_cblock(from_cblock(result->begin) + 1u); | |
3659 | return 0; | |
3660 | } | |
3661 | ||
b61d9509 | 3662 | DMERR("%s: invalid cblock range '%s'", cache_device_name(cache), str); |
65790ff9 JT |
3663 | return -EINVAL; |
3664 | } | |
3665 | ||
3666 | static int validate_cblock_range(struct cache *cache, struct cblock_range *range) | |
3667 | { | |
3668 | uint64_t b = from_cblock(range->begin); | |
3669 | uint64_t e = from_cblock(range->end); | |
3670 | uint64_t n = from_cblock(cache->cache_size); | |
3671 | ||
3672 | if (b >= n) { | |
b61d9509 MS |
3673 | DMERR("%s: begin cblock out of range: %llu >= %llu", |
3674 | cache_device_name(cache), b, n); | |
65790ff9 JT |
3675 | return -EINVAL; |
3676 | } | |
3677 | ||
3678 | if (e > n) { | |
b61d9509 MS |
3679 | DMERR("%s: end cblock out of range: %llu > %llu", |
3680 | cache_device_name(cache), e, n); | |
65790ff9 JT |
3681 | return -EINVAL; |
3682 | } | |
3683 | ||
3684 | if (b >= e) { | |
b61d9509 MS |
3685 | DMERR("%s: invalid cblock range: %llu >= %llu", |
3686 | cache_device_name(cache), b, e); | |
65790ff9 JT |
3687 | return -EINVAL; |
3688 | } | |
3689 | ||
3690 | return 0; | |
3691 | } | |
3692 | ||
3693 | static int request_invalidation(struct cache *cache, struct cblock_range *range) | |
3694 | { | |
3695 | struct invalidation_request req; | |
3696 | ||
3697 | INIT_LIST_HEAD(&req.list); | |
3698 | req.cblocks = range; | |
3699 | atomic_set(&req.complete, 0); | |
3700 | req.err = 0; | |
3701 | init_waitqueue_head(&req.result_wait); | |
3702 | ||
3703 | spin_lock(&cache->invalidation_lock); | |
3704 | list_add(&req.list, &cache->invalidation_requests); | |
3705 | spin_unlock(&cache->invalidation_lock); | |
3706 | wake_worker(cache); | |
3707 | ||
3708 | wait_event(req.result_wait, atomic_read(&req.complete)); | |
3709 | return req.err; | |
3710 | } | |
3711 | ||
3712 | static int process_invalidate_cblocks_message(struct cache *cache, unsigned count, | |
3713 | const char **cblock_ranges) | |
3714 | { | |
3715 | int r = 0; | |
3716 | unsigned i; | |
3717 | struct cblock_range range; | |
3718 | ||
3719 | if (!passthrough_mode(&cache->features)) { | |
b61d9509 MS |
3720 | DMERR("%s: cache has to be in passthrough mode for invalidation", |
3721 | cache_device_name(cache)); | |
65790ff9 JT |
3722 | return -EPERM; |
3723 | } | |
3724 | ||
3725 | for (i = 0; i < count; i++) { | |
3726 | r = parse_cblock_range(cache, cblock_ranges[i], &range); | |
3727 | if (r) | |
3728 | break; | |
3729 | ||
3730 | r = validate_cblock_range(cache, &range); | |
3731 | if (r) | |
3732 | break; | |
3733 | ||
3734 | /* | |
3735 | * Pass begin and end origin blocks to the worker and wake it. | |
3736 | */ | |
3737 | r = request_invalidation(cache, &range); | |
3738 | if (r) | |
3739 | break; | |
3740 | } | |
3741 | ||
3742 | return r; | |
3743 | } | |
3744 | ||
3745 | /* | |
3746 | * Supports | |
3747 | * "<key> <value>" | |
3748 | * and | |
3749 | * "invalidate_cblocks [(<begin>)|(<begin>-<end>)]* | |
c6b4fcba JT |
3750 | * |
3751 | * The key migration_threshold is supported by the cache target core. | |
3752 | */ | |
3753 | static int cache_message(struct dm_target *ti, unsigned argc, char **argv) | |
3754 | { | |
c6b4fcba JT |
3755 | struct cache *cache = ti->private; |
3756 | ||
65790ff9 JT |
3757 | if (!argc) |
3758 | return -EINVAL; | |
3759 | ||
028ae9f7 | 3760 | if (get_cache_mode(cache) >= CM_READ_ONLY) { |
b61d9509 MS |
3761 | DMERR("%s: unable to service cache target messages in READ_ONLY or FAIL mode", |
3762 | cache_device_name(cache)); | |
028ae9f7 JT |
3763 | return -EOPNOTSUPP; |
3764 | } | |
3765 | ||
7b6b2bc9 | 3766 | if (!strcasecmp(argv[0], "invalidate_cblocks")) |
65790ff9 JT |
3767 | return process_invalidate_cblocks_message(cache, argc - 1, (const char **) argv + 1); |
3768 | ||
c6b4fcba JT |
3769 | if (argc != 2) |
3770 | return -EINVAL; | |
3771 | ||
2f14f4b5 | 3772 | return set_config_value(cache, argv[0], argv[1]); |
c6b4fcba JT |
3773 | } |
3774 | ||
3775 | static int cache_iterate_devices(struct dm_target *ti, | |
3776 | iterate_devices_callout_fn fn, void *data) | |
3777 | { | |
3778 | int r = 0; | |
3779 | struct cache *cache = ti->private; | |
3780 | ||
3781 | r = fn(ti, cache->cache_dev, 0, get_dev_size(cache->cache_dev), data); | |
3782 | if (!r) | |
3783 | r = fn(ti, cache->origin_dev, 0, ti->len, data); | |
3784 | ||
3785 | return r; | |
3786 | } | |
3787 | ||
c6b4fcba JT |
3788 | static void set_discard_limits(struct cache *cache, struct queue_limits *limits) |
3789 | { | |
3790 | /* | |
3791 | * FIXME: these limits may be incompatible with the cache device | |
3792 | */ | |
7ae34e77 JT |
3793 | limits->max_discard_sectors = min_t(sector_t, cache->discard_block_size * 1024, |
3794 | cache->origin_sectors); | |
1bad9bc4 | 3795 | limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT; |
c6b4fcba JT |
3796 | } |
3797 | ||
3798 | static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
3799 | { | |
3800 | struct cache *cache = ti->private; | |
f6109372 | 3801 | uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; |
c6b4fcba | 3802 | |
f6109372 MS |
3803 | /* |
3804 | * If the system-determined stacked limits are compatible with the | |
3805 | * cache's blocksize (io_opt is a factor) do not override them. | |
3806 | */ | |
3807 | if (io_opt_sectors < cache->sectors_per_block || | |
3808 | do_div(io_opt_sectors, cache->sectors_per_block)) { | |
b0246530 | 3809 | blk_limits_io_min(limits, cache->sectors_per_block << SECTOR_SHIFT); |
f6109372 MS |
3810 | blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT); |
3811 | } | |
c6b4fcba JT |
3812 | set_discard_limits(cache, limits); |
3813 | } | |
3814 | ||
3815 | /*----------------------------------------------------------------*/ | |
3816 | ||
3817 | static struct target_type cache_target = { | |
3818 | .name = "cache", | |
843f0f2e | 3819 | .version = {1, 9, 0}, |
c6b4fcba JT |
3820 | .module = THIS_MODULE, |
3821 | .ctr = cache_ctr, | |
3822 | .dtr = cache_dtr, | |
3823 | .map = cache_map, | |
3824 | .end_io = cache_end_io, | |
3825 | .postsuspend = cache_postsuspend, | |
3826 | .preresume = cache_preresume, | |
3827 | .resume = cache_resume, | |
3828 | .status = cache_status, | |
3829 | .message = cache_message, | |
3830 | .iterate_devices = cache_iterate_devices, | |
c6b4fcba JT |
3831 | .io_hints = cache_io_hints, |
3832 | }; | |
3833 | ||
3834 | static int __init dm_cache_init(void) | |
3835 | { | |
3836 | int r; | |
3837 | ||
3838 | r = dm_register_target(&cache_target); | |
3839 | if (r) { | |
3840 | DMERR("cache target registration failed: %d", r); | |
3841 | return r; | |
3842 | } | |
3843 | ||
3844 | migration_cache = KMEM_CACHE(dm_cache_migration, 0); | |
3845 | if (!migration_cache) { | |
3846 | dm_unregister_target(&cache_target); | |
3847 | return -ENOMEM; | |
3848 | } | |
3849 | ||
3850 | return 0; | |
3851 | } | |
3852 | ||
3853 | static void __exit dm_cache_exit(void) | |
3854 | { | |
3855 | dm_unregister_target(&cache_target); | |
3856 | kmem_cache_destroy(migration_cache); | |
3857 | } | |
3858 | ||
3859 | module_init(dm_cache_init); | |
3860 | module_exit(dm_cache_exit); | |
3861 | ||
3862 | MODULE_DESCRIPTION(DM_NAME " cache target"); | |
3863 | MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); | |
3864 | MODULE_LICENSE("GPL"); |