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