Commit | Line | Data |
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c6b4fcba JT |
1 | /* |
2 | * Copyright (C) 2012 Red Hat, Inc. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7 | #include "dm-cache-metadata.h" | |
8 | ||
9 | #include "persistent-data/dm-array.h" | |
10 | #include "persistent-data/dm-bitset.h" | |
11 | #include "persistent-data/dm-space-map.h" | |
12 | #include "persistent-data/dm-space-map-disk.h" | |
13 | #include "persistent-data/dm-transaction-manager.h" | |
14 | ||
15 | #include <linux/device-mapper.h> | |
16 | ||
17 | /*----------------------------------------------------------------*/ | |
18 | ||
19 | #define DM_MSG_PREFIX "cache metadata" | |
20 | ||
21 | #define CACHE_SUPERBLOCK_MAGIC 06142003 | |
22 | #define CACHE_SUPERBLOCK_LOCATION 0 | |
53d49819 JT |
23 | |
24 | /* | |
25 | * defines a range of metadata versions that this module can handle. | |
26 | */ | |
27 | #define MIN_CACHE_VERSION 1 | |
28 | #define MAX_CACHE_VERSION 1 | |
29 | ||
c6b4fcba JT |
30 | #define CACHE_METADATA_CACHE_SIZE 64 |
31 | ||
32 | /* | |
33 | * 3 for btree insert + | |
34 | * 2 for btree lookup used within space map | |
35 | */ | |
36 | #define CACHE_MAX_CONCURRENT_LOCKS 5 | |
37 | #define SPACE_MAP_ROOT_SIZE 128 | |
38 | ||
39 | enum superblock_flag_bits { | |
40 | /* for spotting crashes that would invalidate the dirty bitset */ | |
41 | CLEAN_SHUTDOWN, | |
42 | }; | |
43 | ||
44 | /* | |
45 | * Each mapping from cache block -> origin block carries a set of flags. | |
46 | */ | |
47 | enum mapping_bits { | |
48 | /* | |
49 | * A valid mapping. Because we're using an array we clear this | |
50 | * flag for an non existant mapping. | |
51 | */ | |
52 | M_VALID = 1, | |
53 | ||
54 | /* | |
55 | * The data on the cache is different from that on the origin. | |
56 | */ | |
57 | M_DIRTY = 2 | |
58 | }; | |
59 | ||
60 | struct cache_disk_superblock { | |
61 | __le32 csum; | |
62 | __le32 flags; | |
63 | __le64 blocknr; | |
64 | ||
65 | __u8 uuid[16]; | |
66 | __le64 magic; | |
67 | __le32 version; | |
68 | ||
69 | __u8 policy_name[CACHE_POLICY_NAME_SIZE]; | |
70 | __le32 policy_hint_size; | |
71 | ||
72 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; | |
73 | __le64 mapping_root; | |
74 | __le64 hint_root; | |
75 | ||
76 | __le64 discard_root; | |
77 | __le64 discard_block_size; | |
78 | __le64 discard_nr_blocks; | |
79 | ||
80 | __le32 data_block_size; | |
81 | __le32 metadata_block_size; | |
82 | __le32 cache_blocks; | |
83 | ||
84 | __le32 compat_flags; | |
85 | __le32 compat_ro_flags; | |
86 | __le32 incompat_flags; | |
87 | ||
88 | __le32 read_hits; | |
89 | __le32 read_misses; | |
90 | __le32 write_hits; | |
91 | __le32 write_misses; | |
4e7f506f MS |
92 | |
93 | __le32 policy_version[CACHE_POLICY_VERSION_SIZE]; | |
c6b4fcba JT |
94 | } __packed; |
95 | ||
96 | struct dm_cache_metadata { | |
9b1cc9f2 JT |
97 | atomic_t ref_count; |
98 | struct list_head list; | |
99 | ||
c6b4fcba JT |
100 | struct block_device *bdev; |
101 | struct dm_block_manager *bm; | |
102 | struct dm_space_map *metadata_sm; | |
103 | struct dm_transaction_manager *tm; | |
104 | ||
105 | struct dm_array_info info; | |
106 | struct dm_array_info hint_info; | |
107 | struct dm_disk_bitset discard_info; | |
108 | ||
109 | struct rw_semaphore root_lock; | |
110 | dm_block_t root; | |
111 | dm_block_t hint_root; | |
112 | dm_block_t discard_root; | |
113 | ||
114 | sector_t discard_block_size; | |
1bad9bc4 | 115 | dm_dblock_t discard_nr_blocks; |
c6b4fcba JT |
116 | |
117 | sector_t data_block_size; | |
118 | dm_cblock_t cache_blocks; | |
119 | bool changed:1; | |
120 | bool clean_when_opened:1; | |
121 | ||
122 | char policy_name[CACHE_POLICY_NAME_SIZE]; | |
4e7f506f | 123 | unsigned policy_version[CACHE_POLICY_VERSION_SIZE]; |
c6b4fcba JT |
124 | size_t policy_hint_size; |
125 | struct dm_cache_statistics stats; | |
5a32083d JT |
126 | |
127 | /* | |
128 | * Reading the space map root can fail, so we read it into this | |
129 | * buffer before the superblock is locked and updated. | |
130 | */ | |
131 | __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; | |
c6b4fcba JT |
132 | }; |
133 | ||
134 | /*------------------------------------------------------------------- | |
135 | * superblock validator | |
136 | *-----------------------------------------------------------------*/ | |
137 | ||
138 | #define SUPERBLOCK_CSUM_XOR 9031977 | |
139 | ||
140 | static void sb_prepare_for_write(struct dm_block_validator *v, | |
141 | struct dm_block *b, | |
142 | size_t sb_block_size) | |
143 | { | |
144 | struct cache_disk_superblock *disk_super = dm_block_data(b); | |
145 | ||
146 | disk_super->blocknr = cpu_to_le64(dm_block_location(b)); | |
147 | disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags, | |
148 | sb_block_size - sizeof(__le32), | |
149 | SUPERBLOCK_CSUM_XOR)); | |
150 | } | |
151 | ||
53d49819 JT |
152 | static int check_metadata_version(struct cache_disk_superblock *disk_super) |
153 | { | |
154 | uint32_t metadata_version = le32_to_cpu(disk_super->version); | |
155 | if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) { | |
156 | DMERR("Cache metadata version %u found, but only versions between %u and %u supported.", | |
157 | metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION); | |
158 | return -EINVAL; | |
159 | } | |
160 | ||
161 | return 0; | |
162 | } | |
163 | ||
c6b4fcba JT |
164 | static int sb_check(struct dm_block_validator *v, |
165 | struct dm_block *b, | |
166 | size_t sb_block_size) | |
167 | { | |
168 | struct cache_disk_superblock *disk_super = dm_block_data(b); | |
169 | __le32 csum_le; | |
170 | ||
171 | if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) { | |
172 | DMERR("sb_check failed: blocknr %llu: wanted %llu", | |
173 | le64_to_cpu(disk_super->blocknr), | |
174 | (unsigned long long)dm_block_location(b)); | |
175 | return -ENOTBLK; | |
176 | } | |
177 | ||
178 | if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) { | |
179 | DMERR("sb_check failed: magic %llu: wanted %llu", | |
180 | le64_to_cpu(disk_super->magic), | |
181 | (unsigned long long)CACHE_SUPERBLOCK_MAGIC); | |
182 | return -EILSEQ; | |
183 | } | |
184 | ||
185 | csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags, | |
186 | sb_block_size - sizeof(__le32), | |
187 | SUPERBLOCK_CSUM_XOR)); | |
188 | if (csum_le != disk_super->csum) { | |
189 | DMERR("sb_check failed: csum %u: wanted %u", | |
190 | le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum)); | |
191 | return -EILSEQ; | |
192 | } | |
193 | ||
53d49819 | 194 | return check_metadata_version(disk_super); |
c6b4fcba JT |
195 | } |
196 | ||
197 | static struct dm_block_validator sb_validator = { | |
198 | .name = "superblock", | |
199 | .prepare_for_write = sb_prepare_for_write, | |
200 | .check = sb_check | |
201 | }; | |
202 | ||
203 | /*----------------------------------------------------------------*/ | |
204 | ||
205 | static int superblock_read_lock(struct dm_cache_metadata *cmd, | |
206 | struct dm_block **sblock) | |
207 | { | |
208 | return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION, | |
209 | &sb_validator, sblock); | |
210 | } | |
211 | ||
212 | static int superblock_lock_zero(struct dm_cache_metadata *cmd, | |
213 | struct dm_block **sblock) | |
214 | { | |
215 | return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION, | |
216 | &sb_validator, sblock); | |
217 | } | |
218 | ||
219 | static int superblock_lock(struct dm_cache_metadata *cmd, | |
220 | struct dm_block **sblock) | |
221 | { | |
222 | return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION, | |
223 | &sb_validator, sblock); | |
224 | } | |
225 | ||
226 | /*----------------------------------------------------------------*/ | |
227 | ||
dd8b0c20 | 228 | static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result) |
c6b4fcba JT |
229 | { |
230 | int r; | |
231 | unsigned i; | |
232 | struct dm_block *b; | |
233 | __le64 *data_le, zero = cpu_to_le64(0); | |
234 | unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64); | |
235 | ||
236 | /* | |
237 | * We can't use a validator here - it may be all zeroes. | |
238 | */ | |
239 | r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b); | |
240 | if (r) | |
241 | return r; | |
242 | ||
243 | data_le = dm_block_data(b); | |
dd8b0c20 | 244 | *result = true; |
c6b4fcba JT |
245 | for (i = 0; i < sb_block_size; i++) { |
246 | if (data_le[i] != zero) { | |
dd8b0c20 | 247 | *result = false; |
c6b4fcba JT |
248 | break; |
249 | } | |
250 | } | |
251 | ||
252 | return dm_bm_unlock(b); | |
253 | } | |
254 | ||
255 | static void __setup_mapping_info(struct dm_cache_metadata *cmd) | |
256 | { | |
257 | struct dm_btree_value_type vt; | |
258 | ||
259 | vt.context = NULL; | |
260 | vt.size = sizeof(__le64); | |
261 | vt.inc = NULL; | |
262 | vt.dec = NULL; | |
263 | vt.equal = NULL; | |
264 | dm_array_info_init(&cmd->info, cmd->tm, &vt); | |
265 | ||
266 | if (cmd->policy_hint_size) { | |
267 | vt.size = sizeof(__le32); | |
268 | dm_array_info_init(&cmd->hint_info, cmd->tm, &vt); | |
269 | } | |
270 | } | |
271 | ||
5a32083d JT |
272 | static int __save_sm_root(struct dm_cache_metadata *cmd) |
273 | { | |
274 | int r; | |
275 | size_t metadata_len; | |
276 | ||
277 | r = dm_sm_root_size(cmd->metadata_sm, &metadata_len); | |
278 | if (r < 0) | |
279 | return r; | |
280 | ||
281 | return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root, | |
282 | metadata_len); | |
283 | } | |
284 | ||
285 | static void __copy_sm_root(struct dm_cache_metadata *cmd, | |
286 | struct cache_disk_superblock *disk_super) | |
287 | { | |
288 | memcpy(&disk_super->metadata_space_map_root, | |
289 | &cmd->metadata_space_map_root, | |
290 | sizeof(cmd->metadata_space_map_root)); | |
291 | } | |
292 | ||
c6b4fcba JT |
293 | static int __write_initial_superblock(struct dm_cache_metadata *cmd) |
294 | { | |
295 | int r; | |
296 | struct dm_block *sblock; | |
c6b4fcba JT |
297 | struct cache_disk_superblock *disk_super; |
298 | sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT; | |
299 | ||
300 | /* FIXME: see if we can lose the max sectors limit */ | |
301 | if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS) | |
302 | bdev_size = DM_CACHE_METADATA_MAX_SECTORS; | |
303 | ||
5a32083d | 304 | r = dm_tm_pre_commit(cmd->tm); |
c6b4fcba JT |
305 | if (r < 0) |
306 | return r; | |
307 | ||
5a32083d JT |
308 | /* |
309 | * dm_sm_copy_root() can fail. So we need to do it before we start | |
310 | * updating the superblock. | |
311 | */ | |
312 | r = __save_sm_root(cmd); | |
313 | if (r) | |
c6b4fcba JT |
314 | return r; |
315 | ||
316 | r = superblock_lock_zero(cmd, &sblock); | |
317 | if (r) | |
318 | return r; | |
319 | ||
320 | disk_super = dm_block_data(sblock); | |
321 | disk_super->flags = 0; | |
322 | memset(disk_super->uuid, 0, sizeof(disk_super->uuid)); | |
323 | disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC); | |
53d49819 | 324 | disk_super->version = cpu_to_le32(MAX_CACHE_VERSION); |
4e7f506f MS |
325 | memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name)); |
326 | memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version)); | |
c6b4fcba JT |
327 | disk_super->policy_hint_size = 0; |
328 | ||
5a32083d | 329 | __copy_sm_root(cmd, disk_super); |
c6b4fcba JT |
330 | |
331 | disk_super->mapping_root = cpu_to_le64(cmd->root); | |
332 | disk_super->hint_root = cpu_to_le64(cmd->hint_root); | |
333 | disk_super->discard_root = cpu_to_le64(cmd->discard_root); | |
334 | disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size); | |
1bad9bc4 | 335 | disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks)); |
895b47d7 | 336 | disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE); |
c6b4fcba JT |
337 | disk_super->data_block_size = cpu_to_le32(cmd->data_block_size); |
338 | disk_super->cache_blocks = cpu_to_le32(0); | |
c6b4fcba JT |
339 | |
340 | disk_super->read_hits = cpu_to_le32(0); | |
341 | disk_super->read_misses = cpu_to_le32(0); | |
342 | disk_super->write_hits = cpu_to_le32(0); | |
343 | disk_super->write_misses = cpu_to_le32(0); | |
344 | ||
345 | return dm_tm_commit(cmd->tm, sblock); | |
c6b4fcba JT |
346 | } |
347 | ||
348 | static int __format_metadata(struct dm_cache_metadata *cmd) | |
349 | { | |
350 | int r; | |
351 | ||
352 | r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION, | |
353 | &cmd->tm, &cmd->metadata_sm); | |
354 | if (r < 0) { | |
355 | DMERR("tm_create_with_sm failed"); | |
356 | return r; | |
357 | } | |
358 | ||
359 | __setup_mapping_info(cmd); | |
360 | ||
361 | r = dm_array_empty(&cmd->info, &cmd->root); | |
362 | if (r < 0) | |
363 | goto bad; | |
364 | ||
365 | dm_disk_bitset_init(cmd->tm, &cmd->discard_info); | |
366 | ||
367 | r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root); | |
368 | if (r < 0) | |
369 | goto bad; | |
370 | ||
371 | cmd->discard_block_size = 0; | |
372 | cmd->discard_nr_blocks = 0; | |
373 | ||
374 | r = __write_initial_superblock(cmd); | |
375 | if (r) | |
376 | goto bad; | |
377 | ||
378 | cmd->clean_when_opened = true; | |
379 | return 0; | |
380 | ||
381 | bad: | |
382 | dm_tm_destroy(cmd->tm); | |
383 | dm_sm_destroy(cmd->metadata_sm); | |
384 | ||
385 | return r; | |
386 | } | |
387 | ||
388 | static int __check_incompat_features(struct cache_disk_superblock *disk_super, | |
389 | struct dm_cache_metadata *cmd) | |
390 | { | |
391 | uint32_t features; | |
392 | ||
393 | features = le32_to_cpu(disk_super->incompat_flags) & ~DM_CACHE_FEATURE_INCOMPAT_SUPP; | |
394 | if (features) { | |
395 | DMERR("could not access metadata due to unsupported optional features (%lx).", | |
396 | (unsigned long)features); | |
397 | return -EINVAL; | |
398 | } | |
399 | ||
400 | /* | |
401 | * Check for read-only metadata to skip the following RDWR checks. | |
402 | */ | |
403 | if (get_disk_ro(cmd->bdev->bd_disk)) | |
404 | return 0; | |
405 | ||
406 | features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP; | |
407 | if (features) { | |
408 | DMERR("could not access metadata RDWR due to unsupported optional features (%lx).", | |
409 | (unsigned long)features); | |
410 | return -EINVAL; | |
411 | } | |
412 | ||
413 | return 0; | |
414 | } | |
415 | ||
416 | static int __open_metadata(struct dm_cache_metadata *cmd) | |
417 | { | |
418 | int r; | |
419 | struct dm_block *sblock; | |
420 | struct cache_disk_superblock *disk_super; | |
421 | unsigned long sb_flags; | |
422 | ||
423 | r = superblock_read_lock(cmd, &sblock); | |
424 | if (r < 0) { | |
425 | DMERR("couldn't read lock superblock"); | |
426 | return r; | |
427 | } | |
428 | ||
429 | disk_super = dm_block_data(sblock); | |
430 | ||
048e5a07 MS |
431 | /* Verify the data block size hasn't changed */ |
432 | if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) { | |
433 | DMERR("changing the data block size (from %u to %llu) is not supported", | |
434 | le32_to_cpu(disk_super->data_block_size), | |
435 | (unsigned long long)cmd->data_block_size); | |
436 | r = -EINVAL; | |
437 | goto bad; | |
438 | } | |
439 | ||
c6b4fcba JT |
440 | r = __check_incompat_features(disk_super, cmd); |
441 | if (r < 0) | |
442 | goto bad; | |
443 | ||
444 | r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION, | |
445 | disk_super->metadata_space_map_root, | |
446 | sizeof(disk_super->metadata_space_map_root), | |
447 | &cmd->tm, &cmd->metadata_sm); | |
448 | if (r < 0) { | |
449 | DMERR("tm_open_with_sm failed"); | |
450 | goto bad; | |
451 | } | |
452 | ||
453 | __setup_mapping_info(cmd); | |
454 | dm_disk_bitset_init(cmd->tm, &cmd->discard_info); | |
455 | sb_flags = le32_to_cpu(disk_super->flags); | |
456 | cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags); | |
457 | return dm_bm_unlock(sblock); | |
458 | ||
459 | bad: | |
460 | dm_bm_unlock(sblock); | |
461 | return r; | |
462 | } | |
463 | ||
464 | static int __open_or_format_metadata(struct dm_cache_metadata *cmd, | |
465 | bool format_device) | |
466 | { | |
dd8b0c20 JT |
467 | int r; |
468 | bool unformatted = false; | |
c6b4fcba JT |
469 | |
470 | r = __superblock_all_zeroes(cmd->bm, &unformatted); | |
471 | if (r) | |
472 | return r; | |
473 | ||
474 | if (unformatted) | |
475 | return format_device ? __format_metadata(cmd) : -EPERM; | |
476 | ||
477 | return __open_metadata(cmd); | |
478 | } | |
479 | ||
480 | static int __create_persistent_data_objects(struct dm_cache_metadata *cmd, | |
481 | bool may_format_device) | |
482 | { | |
483 | int r; | |
895b47d7 | 484 | cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT, |
c6b4fcba JT |
485 | CACHE_METADATA_CACHE_SIZE, |
486 | CACHE_MAX_CONCURRENT_LOCKS); | |
487 | if (IS_ERR(cmd->bm)) { | |
488 | DMERR("could not create block manager"); | |
489 | return PTR_ERR(cmd->bm); | |
490 | } | |
491 | ||
492 | r = __open_or_format_metadata(cmd, may_format_device); | |
493 | if (r) | |
494 | dm_block_manager_destroy(cmd->bm); | |
495 | ||
496 | return r; | |
497 | } | |
498 | ||
499 | static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd) | |
500 | { | |
501 | dm_sm_destroy(cmd->metadata_sm); | |
502 | dm_tm_destroy(cmd->tm); | |
503 | dm_block_manager_destroy(cmd->bm); | |
504 | } | |
505 | ||
506 | typedef unsigned long (*flags_mutator)(unsigned long); | |
507 | ||
508 | static void update_flags(struct cache_disk_superblock *disk_super, | |
509 | flags_mutator mutator) | |
510 | { | |
511 | uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags)); | |
512 | disk_super->flags = cpu_to_le32(sb_flags); | |
513 | } | |
514 | ||
515 | static unsigned long set_clean_shutdown(unsigned long flags) | |
516 | { | |
517 | set_bit(CLEAN_SHUTDOWN, &flags); | |
518 | return flags; | |
519 | } | |
520 | ||
521 | static unsigned long clear_clean_shutdown(unsigned long flags) | |
522 | { | |
523 | clear_bit(CLEAN_SHUTDOWN, &flags); | |
524 | return flags; | |
525 | } | |
526 | ||
527 | static void read_superblock_fields(struct dm_cache_metadata *cmd, | |
528 | struct cache_disk_superblock *disk_super) | |
529 | { | |
530 | cmd->root = le64_to_cpu(disk_super->mapping_root); | |
531 | cmd->hint_root = le64_to_cpu(disk_super->hint_root); | |
532 | cmd->discard_root = le64_to_cpu(disk_super->discard_root); | |
533 | cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size); | |
1bad9bc4 | 534 | cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks)); |
c6b4fcba JT |
535 | cmd->data_block_size = le32_to_cpu(disk_super->data_block_size); |
536 | cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks)); | |
537 | strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name)); | |
4e7f506f MS |
538 | cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]); |
539 | cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]); | |
540 | cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]); | |
c6b4fcba JT |
541 | cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size); |
542 | ||
543 | cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits); | |
544 | cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses); | |
545 | cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits); | |
546 | cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses); | |
547 | ||
548 | cmd->changed = false; | |
549 | } | |
550 | ||
551 | /* | |
552 | * The mutator updates the superblock flags. | |
553 | */ | |
554 | static int __begin_transaction_flags(struct dm_cache_metadata *cmd, | |
555 | flags_mutator mutator) | |
556 | { | |
557 | int r; | |
558 | struct cache_disk_superblock *disk_super; | |
559 | struct dm_block *sblock; | |
560 | ||
561 | r = superblock_lock(cmd, &sblock); | |
562 | if (r) | |
563 | return r; | |
564 | ||
565 | disk_super = dm_block_data(sblock); | |
566 | update_flags(disk_super, mutator); | |
567 | read_superblock_fields(cmd, disk_super); | |
a9d45396 | 568 | dm_bm_unlock(sblock); |
c6b4fcba | 569 | |
a9d45396 | 570 | return dm_bm_flush(cmd->bm); |
c6b4fcba JT |
571 | } |
572 | ||
573 | static int __begin_transaction(struct dm_cache_metadata *cmd) | |
574 | { | |
575 | int r; | |
576 | struct cache_disk_superblock *disk_super; | |
577 | struct dm_block *sblock; | |
578 | ||
579 | /* | |
580 | * We re-read the superblock every time. Shouldn't need to do this | |
581 | * really. | |
582 | */ | |
583 | r = superblock_read_lock(cmd, &sblock); | |
584 | if (r) | |
585 | return r; | |
586 | ||
587 | disk_super = dm_block_data(sblock); | |
588 | read_superblock_fields(cmd, disk_super); | |
589 | dm_bm_unlock(sblock); | |
590 | ||
591 | return 0; | |
592 | } | |
593 | ||
594 | static int __commit_transaction(struct dm_cache_metadata *cmd, | |
595 | flags_mutator mutator) | |
596 | { | |
597 | int r; | |
c6b4fcba JT |
598 | struct cache_disk_superblock *disk_super; |
599 | struct dm_block *sblock; | |
600 | ||
601 | /* | |
602 | * We need to know if the cache_disk_superblock exceeds a 512-byte sector. | |
603 | */ | |
604 | BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512); | |
605 | ||
606 | r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, | |
607 | &cmd->discard_root); | |
608 | if (r) | |
609 | return r; | |
610 | ||
611 | r = dm_tm_pre_commit(cmd->tm); | |
612 | if (r < 0) | |
613 | return r; | |
614 | ||
5a32083d JT |
615 | r = __save_sm_root(cmd); |
616 | if (r) | |
c6b4fcba JT |
617 | return r; |
618 | ||
619 | r = superblock_lock(cmd, &sblock); | |
620 | if (r) | |
621 | return r; | |
622 | ||
623 | disk_super = dm_block_data(sblock); | |
624 | ||
625 | if (mutator) | |
626 | update_flags(disk_super, mutator); | |
627 | ||
628 | disk_super->mapping_root = cpu_to_le64(cmd->root); | |
629 | disk_super->hint_root = cpu_to_le64(cmd->hint_root); | |
630 | disk_super->discard_root = cpu_to_le64(cmd->discard_root); | |
631 | disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size); | |
1bad9bc4 | 632 | disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks)); |
c6b4fcba JT |
633 | disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks)); |
634 | strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name)); | |
4e7f506f MS |
635 | disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]); |
636 | disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]); | |
637 | disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]); | |
c6b4fcba JT |
638 | |
639 | disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits); | |
640 | disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses); | |
641 | disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits); | |
642 | disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses); | |
5a32083d | 643 | __copy_sm_root(cmd, disk_super); |
c6b4fcba JT |
644 | |
645 | return dm_tm_commit(cmd->tm, sblock); | |
646 | } | |
647 | ||
648 | /*----------------------------------------------------------------*/ | |
649 | ||
650 | /* | |
651 | * The mappings are held in a dm-array that has 64-bit values stored in | |
652 | * little-endian format. The index is the cblock, the high 48bits of the | |
653 | * value are the oblock and the low 16 bit the flags. | |
654 | */ | |
655 | #define FLAGS_MASK ((1 << 16) - 1) | |
656 | ||
657 | static __le64 pack_value(dm_oblock_t block, unsigned flags) | |
658 | { | |
659 | uint64_t value = from_oblock(block); | |
660 | value <<= 16; | |
661 | value = value | (flags & FLAGS_MASK); | |
662 | return cpu_to_le64(value); | |
663 | } | |
664 | ||
665 | static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags) | |
666 | { | |
667 | uint64_t value = le64_to_cpu(value_le); | |
668 | uint64_t b = value >> 16; | |
669 | *block = to_oblock(b); | |
670 | *flags = value & FLAGS_MASK; | |
671 | } | |
672 | ||
673 | /*----------------------------------------------------------------*/ | |
674 | ||
9b1cc9f2 JT |
675 | static struct dm_cache_metadata *metadata_open(struct block_device *bdev, |
676 | sector_t data_block_size, | |
677 | bool may_format_device, | |
678 | size_t policy_hint_size) | |
c6b4fcba JT |
679 | { |
680 | int r; | |
681 | struct dm_cache_metadata *cmd; | |
682 | ||
683 | cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); | |
684 | if (!cmd) { | |
685 | DMERR("could not allocate metadata struct"); | |
766a7888 | 686 | return ERR_PTR(-ENOMEM); |
c6b4fcba JT |
687 | } |
688 | ||
9b1cc9f2 | 689 | atomic_set(&cmd->ref_count, 1); |
c6b4fcba JT |
690 | init_rwsem(&cmd->root_lock); |
691 | cmd->bdev = bdev; | |
692 | cmd->data_block_size = data_block_size; | |
693 | cmd->cache_blocks = 0; | |
694 | cmd->policy_hint_size = policy_hint_size; | |
695 | cmd->changed = true; | |
696 | ||
697 | r = __create_persistent_data_objects(cmd, may_format_device); | |
698 | if (r) { | |
699 | kfree(cmd); | |
700 | return ERR_PTR(r); | |
701 | } | |
702 | ||
703 | r = __begin_transaction_flags(cmd, clear_clean_shutdown); | |
704 | if (r < 0) { | |
705 | dm_cache_metadata_close(cmd); | |
706 | return ERR_PTR(r); | |
707 | } | |
708 | ||
709 | return cmd; | |
710 | } | |
711 | ||
9b1cc9f2 JT |
712 | /* |
713 | * We keep a little list of ref counted metadata objects to prevent two | |
714 | * different target instances creating separate bufio instances. This is | |
715 | * an issue if a table is reloaded before the suspend. | |
716 | */ | |
717 | static DEFINE_MUTEX(table_lock); | |
718 | static LIST_HEAD(table); | |
719 | ||
720 | static struct dm_cache_metadata *lookup(struct block_device *bdev) | |
721 | { | |
722 | struct dm_cache_metadata *cmd; | |
723 | ||
724 | list_for_each_entry(cmd, &table, list) | |
725 | if (cmd->bdev == bdev) { | |
726 | atomic_inc(&cmd->ref_count); | |
727 | return cmd; | |
728 | } | |
729 | ||
730 | return NULL; | |
731 | } | |
732 | ||
733 | static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev, | |
734 | sector_t data_block_size, | |
735 | bool may_format_device, | |
736 | size_t policy_hint_size) | |
737 | { | |
738 | struct dm_cache_metadata *cmd, *cmd2; | |
739 | ||
740 | mutex_lock(&table_lock); | |
741 | cmd = lookup(bdev); | |
742 | mutex_unlock(&table_lock); | |
743 | ||
744 | if (cmd) | |
745 | return cmd; | |
746 | ||
747 | cmd = metadata_open(bdev, data_block_size, may_format_device, policy_hint_size); | |
766a7888 | 748 | if (!IS_ERR(cmd)) { |
9b1cc9f2 JT |
749 | mutex_lock(&table_lock); |
750 | cmd2 = lookup(bdev); | |
751 | if (cmd2) { | |
752 | mutex_unlock(&table_lock); | |
753 | __destroy_persistent_data_objects(cmd); | |
754 | kfree(cmd); | |
755 | return cmd2; | |
756 | } | |
757 | list_add(&cmd->list, &table); | |
758 | mutex_unlock(&table_lock); | |
759 | } | |
760 | ||
761 | return cmd; | |
762 | } | |
763 | ||
764 | static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size) | |
765 | { | |
766 | if (cmd->data_block_size != data_block_size) { | |
767 | DMERR("data_block_size (%llu) different from that in metadata (%llu)\n", | |
768 | (unsigned long long) data_block_size, | |
769 | (unsigned long long) cmd->data_block_size); | |
770 | return false; | |
771 | } | |
772 | ||
773 | return true; | |
774 | } | |
775 | ||
776 | struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev, | |
777 | sector_t data_block_size, | |
778 | bool may_format_device, | |
779 | size_t policy_hint_size) | |
780 | { | |
781 | struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, | |
782 | may_format_device, policy_hint_size); | |
766a7888 JT |
783 | |
784 | if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) { | |
9b1cc9f2 | 785 | dm_cache_metadata_close(cmd); |
766a7888 | 786 | return ERR_PTR(-EINVAL); |
9b1cc9f2 JT |
787 | } |
788 | ||
789 | return cmd; | |
790 | } | |
791 | ||
c6b4fcba JT |
792 | void dm_cache_metadata_close(struct dm_cache_metadata *cmd) |
793 | { | |
9b1cc9f2 JT |
794 | if (atomic_dec_and_test(&cmd->ref_count)) { |
795 | mutex_lock(&table_lock); | |
796 | list_del(&cmd->list); | |
797 | mutex_unlock(&table_lock); | |
798 | ||
799 | __destroy_persistent_data_objects(cmd); | |
800 | kfree(cmd); | |
801 | } | |
c6b4fcba JT |
802 | } |
803 | ||
f494a9c6 JT |
804 | /* |
805 | * Checks that the given cache block is either unmapped or clean. | |
806 | */ | |
807 | static int block_unmapped_or_clean(struct dm_cache_metadata *cmd, dm_cblock_t b, | |
808 | bool *result) | |
809 | { | |
810 | int r; | |
811 | __le64 value; | |
812 | dm_oblock_t ob; | |
813 | unsigned flags; | |
814 | ||
815 | r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value); | |
816 | if (r) { | |
817 | DMERR("block_unmapped_or_clean failed"); | |
818 | return r; | |
819 | } | |
820 | ||
821 | unpack_value(value, &ob, &flags); | |
822 | *result = !((flags & M_VALID) && (flags & M_DIRTY)); | |
823 | ||
824 | return 0; | |
825 | } | |
826 | ||
827 | static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd, | |
828 | dm_cblock_t begin, dm_cblock_t end, | |
829 | bool *result) | |
830 | { | |
831 | int r; | |
832 | *result = true; | |
833 | ||
834 | while (begin != end) { | |
835 | r = block_unmapped_or_clean(cmd, begin, result); | |
836 | if (r) | |
837 | return r; | |
838 | ||
839 | if (!*result) { | |
840 | DMERR("cache block %llu is dirty", | |
841 | (unsigned long long) from_cblock(begin)); | |
842 | return 0; | |
843 | } | |
844 | ||
845 | begin = to_cblock(from_cblock(begin) + 1); | |
846 | } | |
847 | ||
848 | return 0; | |
849 | } | |
850 | ||
c6b4fcba JT |
851 | int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size) |
852 | { | |
853 | int r; | |
f494a9c6 | 854 | bool clean; |
c6b4fcba JT |
855 | __le64 null_mapping = pack_value(0, 0); |
856 | ||
857 | down_write(&cmd->root_lock); | |
858 | __dm_bless_for_disk(&null_mapping); | |
f494a9c6 JT |
859 | |
860 | if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) { | |
861 | r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean); | |
862 | if (r) { | |
863 | __dm_unbless_for_disk(&null_mapping); | |
864 | goto out; | |
865 | } | |
866 | ||
867 | if (!clean) { | |
868 | DMERR("unable to shrink cache due to dirty blocks"); | |
869 | r = -EINVAL; | |
870 | __dm_unbless_for_disk(&null_mapping); | |
871 | goto out; | |
872 | } | |
873 | } | |
874 | ||
c6b4fcba JT |
875 | r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks), |
876 | from_cblock(new_cache_size), | |
877 | &null_mapping, &cmd->root); | |
878 | if (!r) | |
879 | cmd->cache_blocks = new_cache_size; | |
880 | cmd->changed = true; | |
f494a9c6 JT |
881 | |
882 | out: | |
c6b4fcba JT |
883 | up_write(&cmd->root_lock); |
884 | ||
885 | return r; | |
886 | } | |
887 | ||
888 | int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd, | |
889 | sector_t discard_block_size, | |
1bad9bc4 | 890 | dm_dblock_t new_nr_entries) |
c6b4fcba JT |
891 | { |
892 | int r; | |
893 | ||
894 | down_write(&cmd->root_lock); | |
895 | r = dm_bitset_resize(&cmd->discard_info, | |
896 | cmd->discard_root, | |
1bad9bc4 JT |
897 | from_dblock(cmd->discard_nr_blocks), |
898 | from_dblock(new_nr_entries), | |
c6b4fcba JT |
899 | false, &cmd->discard_root); |
900 | if (!r) { | |
901 | cmd->discard_block_size = discard_block_size; | |
902 | cmd->discard_nr_blocks = new_nr_entries; | |
903 | } | |
904 | ||
905 | cmd->changed = true; | |
906 | up_write(&cmd->root_lock); | |
907 | ||
908 | return r; | |
909 | } | |
910 | ||
1bad9bc4 | 911 | static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b) |
c6b4fcba JT |
912 | { |
913 | return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root, | |
1bad9bc4 | 914 | from_dblock(b), &cmd->discard_root); |
c6b4fcba JT |
915 | } |
916 | ||
1bad9bc4 | 917 | static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b) |
c6b4fcba JT |
918 | { |
919 | return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root, | |
1bad9bc4 | 920 | from_dblock(b), &cmd->discard_root); |
c6b4fcba JT |
921 | } |
922 | ||
1bad9bc4 | 923 | static int __is_discarded(struct dm_cache_metadata *cmd, dm_dblock_t b, |
c6b4fcba JT |
924 | bool *is_discarded) |
925 | { | |
926 | return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root, | |
1bad9bc4 | 927 | from_dblock(b), &cmd->discard_root, |
c6b4fcba JT |
928 | is_discarded); |
929 | } | |
930 | ||
931 | static int __discard(struct dm_cache_metadata *cmd, | |
1bad9bc4 | 932 | dm_dblock_t dblock, bool discard) |
c6b4fcba JT |
933 | { |
934 | int r; | |
935 | ||
936 | r = (discard ? __set_discard : __clear_discard)(cmd, dblock); | |
937 | if (r) | |
938 | return r; | |
939 | ||
940 | cmd->changed = true; | |
941 | return 0; | |
942 | } | |
943 | ||
944 | int dm_cache_set_discard(struct dm_cache_metadata *cmd, | |
1bad9bc4 | 945 | dm_dblock_t dblock, bool discard) |
c6b4fcba JT |
946 | { |
947 | int r; | |
948 | ||
949 | down_write(&cmd->root_lock); | |
950 | r = __discard(cmd, dblock, discard); | |
951 | up_write(&cmd->root_lock); | |
952 | ||
953 | return r; | |
954 | } | |
955 | ||
956 | static int __load_discards(struct dm_cache_metadata *cmd, | |
957 | load_discard_fn fn, void *context) | |
958 | { | |
959 | int r = 0; | |
960 | dm_block_t b; | |
961 | bool discard; | |
962 | ||
1bad9bc4 JT |
963 | for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) { |
964 | dm_dblock_t dblock = to_dblock(b); | |
c6b4fcba JT |
965 | |
966 | if (cmd->clean_when_opened) { | |
967 | r = __is_discarded(cmd, dblock, &discard); | |
968 | if (r) | |
969 | return r; | |
970 | } else | |
971 | discard = false; | |
972 | ||
973 | r = fn(context, cmd->discard_block_size, dblock, discard); | |
974 | if (r) | |
975 | break; | |
976 | } | |
977 | ||
978 | return r; | |
979 | } | |
980 | ||
981 | int dm_cache_load_discards(struct dm_cache_metadata *cmd, | |
982 | load_discard_fn fn, void *context) | |
983 | { | |
984 | int r; | |
985 | ||
986 | down_read(&cmd->root_lock); | |
987 | r = __load_discards(cmd, fn, context); | |
988 | up_read(&cmd->root_lock); | |
989 | ||
990 | return r; | |
991 | } | |
992 | ||
993 | dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd) | |
994 | { | |
995 | dm_cblock_t r; | |
996 | ||
997 | down_read(&cmd->root_lock); | |
998 | r = cmd->cache_blocks; | |
999 | up_read(&cmd->root_lock); | |
1000 | ||
1001 | return r; | |
1002 | } | |
1003 | ||
1004 | static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock) | |
1005 | { | |
1006 | int r; | |
1007 | __le64 value = pack_value(0, 0); | |
1008 | ||
1009 | __dm_bless_for_disk(&value); | |
1010 | r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), | |
1011 | &value, &cmd->root); | |
1012 | if (r) | |
1013 | return r; | |
1014 | ||
1015 | cmd->changed = true; | |
1016 | return 0; | |
1017 | } | |
1018 | ||
1019 | int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock) | |
1020 | { | |
1021 | int r; | |
1022 | ||
1023 | down_write(&cmd->root_lock); | |
1024 | r = __remove(cmd, cblock); | |
1025 | up_write(&cmd->root_lock); | |
1026 | ||
1027 | return r; | |
1028 | } | |
1029 | ||
1030 | static int __insert(struct dm_cache_metadata *cmd, | |
1031 | dm_cblock_t cblock, dm_oblock_t oblock) | |
1032 | { | |
1033 | int r; | |
1034 | __le64 value = pack_value(oblock, M_VALID); | |
1035 | __dm_bless_for_disk(&value); | |
1036 | ||
1037 | r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), | |
1038 | &value, &cmd->root); | |
1039 | if (r) | |
1040 | return r; | |
1041 | ||
1042 | cmd->changed = true; | |
1043 | return 0; | |
1044 | } | |
1045 | ||
1046 | int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, | |
1047 | dm_cblock_t cblock, dm_oblock_t oblock) | |
1048 | { | |
1049 | int r; | |
1050 | ||
1051 | down_write(&cmd->root_lock); | |
1052 | r = __insert(cmd, cblock, oblock); | |
1053 | up_write(&cmd->root_lock); | |
1054 | ||
1055 | return r; | |
1056 | } | |
1057 | ||
1058 | struct thunk { | |
1059 | load_mapping_fn fn; | |
1060 | void *context; | |
1061 | ||
1062 | struct dm_cache_metadata *cmd; | |
1063 | bool respect_dirty_flags; | |
1064 | bool hints_valid; | |
1065 | }; | |
1066 | ||
ea2dd8c1 MS |
1067 | static bool policy_unchanged(struct dm_cache_metadata *cmd, |
1068 | struct dm_cache_policy *policy) | |
1069 | { | |
1070 | const char *policy_name = dm_cache_policy_get_name(policy); | |
1071 | const unsigned *policy_version = dm_cache_policy_get_version(policy); | |
1072 | size_t policy_hint_size = dm_cache_policy_get_hint_size(policy); | |
1073 | ||
1074 | /* | |
1075 | * Ensure policy names match. | |
1076 | */ | |
1077 | if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name))) | |
1078 | return false; | |
1079 | ||
1080 | /* | |
1081 | * Ensure policy major versions match. | |
1082 | */ | |
1083 | if (cmd->policy_version[0] != policy_version[0]) | |
1084 | return false; | |
1085 | ||
1086 | /* | |
1087 | * Ensure policy hint sizes match. | |
1088 | */ | |
1089 | if (cmd->policy_hint_size != policy_hint_size) | |
1090 | return false; | |
1091 | ||
1092 | return true; | |
1093 | } | |
1094 | ||
c6b4fcba JT |
1095 | static bool hints_array_initialized(struct dm_cache_metadata *cmd) |
1096 | { | |
1097 | return cmd->hint_root && cmd->policy_hint_size; | |
1098 | } | |
1099 | ||
1100 | static bool hints_array_available(struct dm_cache_metadata *cmd, | |
ea2dd8c1 | 1101 | struct dm_cache_policy *policy) |
c6b4fcba | 1102 | { |
ea2dd8c1 | 1103 | return cmd->clean_when_opened && policy_unchanged(cmd, policy) && |
c6b4fcba JT |
1104 | hints_array_initialized(cmd); |
1105 | } | |
1106 | ||
1107 | static int __load_mapping(void *context, uint64_t cblock, void *leaf) | |
1108 | { | |
1109 | int r = 0; | |
1110 | bool dirty; | |
1111 | __le64 value; | |
1112 | __le32 hint_value = 0; | |
1113 | dm_oblock_t oblock; | |
1114 | unsigned flags; | |
1115 | struct thunk *thunk = context; | |
1116 | struct dm_cache_metadata *cmd = thunk->cmd; | |
1117 | ||
1118 | memcpy(&value, leaf, sizeof(value)); | |
1119 | unpack_value(value, &oblock, &flags); | |
1120 | ||
1121 | if (flags & M_VALID) { | |
1122 | if (thunk->hints_valid) { | |
1123 | r = dm_array_get_value(&cmd->hint_info, cmd->hint_root, | |
1124 | cblock, &hint_value); | |
1125 | if (r && r != -ENODATA) | |
1126 | return r; | |
1127 | } | |
1128 | ||
1129 | dirty = thunk->respect_dirty_flags ? (flags & M_DIRTY) : true; | |
1130 | r = thunk->fn(thunk->context, oblock, to_cblock(cblock), | |
1131 | dirty, le32_to_cpu(hint_value), thunk->hints_valid); | |
1132 | } | |
1133 | ||
1134 | return r; | |
1135 | } | |
1136 | ||
ea2dd8c1 MS |
1137 | static int __load_mappings(struct dm_cache_metadata *cmd, |
1138 | struct dm_cache_policy *policy, | |
c6b4fcba JT |
1139 | load_mapping_fn fn, void *context) |
1140 | { | |
1141 | struct thunk thunk; | |
1142 | ||
1143 | thunk.fn = fn; | |
1144 | thunk.context = context; | |
1145 | ||
1146 | thunk.cmd = cmd; | |
1147 | thunk.respect_dirty_flags = cmd->clean_when_opened; | |
ea2dd8c1 | 1148 | thunk.hints_valid = hints_array_available(cmd, policy); |
c6b4fcba JT |
1149 | |
1150 | return dm_array_walk(&cmd->info, cmd->root, __load_mapping, &thunk); | |
1151 | } | |
1152 | ||
ea2dd8c1 MS |
1153 | int dm_cache_load_mappings(struct dm_cache_metadata *cmd, |
1154 | struct dm_cache_policy *policy, | |
c6b4fcba JT |
1155 | load_mapping_fn fn, void *context) |
1156 | { | |
1157 | int r; | |
1158 | ||
1159 | down_read(&cmd->root_lock); | |
ea2dd8c1 | 1160 | r = __load_mappings(cmd, policy, fn, context); |
c6b4fcba JT |
1161 | up_read(&cmd->root_lock); |
1162 | ||
1163 | return r; | |
1164 | } | |
1165 | ||
1166 | static int __dump_mapping(void *context, uint64_t cblock, void *leaf) | |
1167 | { | |
1168 | int r = 0; | |
1169 | __le64 value; | |
1170 | dm_oblock_t oblock; | |
1171 | unsigned flags; | |
1172 | ||
1173 | memcpy(&value, leaf, sizeof(value)); | |
1174 | unpack_value(value, &oblock, &flags); | |
1175 | ||
1176 | return r; | |
1177 | } | |
1178 | ||
1179 | static int __dump_mappings(struct dm_cache_metadata *cmd) | |
1180 | { | |
1181 | return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL); | |
1182 | } | |
1183 | ||
1184 | void dm_cache_dump(struct dm_cache_metadata *cmd) | |
1185 | { | |
1186 | down_read(&cmd->root_lock); | |
1187 | __dump_mappings(cmd); | |
1188 | up_read(&cmd->root_lock); | |
1189 | } | |
1190 | ||
1191 | int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd) | |
1192 | { | |
1193 | int r; | |
1194 | ||
1195 | down_read(&cmd->root_lock); | |
1196 | r = cmd->changed; | |
1197 | up_read(&cmd->root_lock); | |
1198 | ||
1199 | return r; | |
1200 | } | |
1201 | ||
1202 | static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty) | |
1203 | { | |
1204 | int r; | |
1205 | unsigned flags; | |
1206 | dm_oblock_t oblock; | |
1207 | __le64 value; | |
1208 | ||
1209 | r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value); | |
1210 | if (r) | |
1211 | return r; | |
1212 | ||
1213 | unpack_value(value, &oblock, &flags); | |
1214 | ||
1215 | if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty)) | |
1216 | /* nothing to be done */ | |
1217 | return 0; | |
1218 | ||
79ed9caf | 1219 | value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0)); |
c6b4fcba JT |
1220 | __dm_bless_for_disk(&value); |
1221 | ||
1222 | r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), | |
1223 | &value, &cmd->root); | |
1224 | if (r) | |
1225 | return r; | |
1226 | ||
1227 | cmd->changed = true; | |
1228 | return 0; | |
1229 | ||
1230 | } | |
1231 | ||
1232 | int dm_cache_set_dirty(struct dm_cache_metadata *cmd, | |
1233 | dm_cblock_t cblock, bool dirty) | |
1234 | { | |
1235 | int r; | |
1236 | ||
1237 | down_write(&cmd->root_lock); | |
1238 | r = __dirty(cmd, cblock, dirty); | |
1239 | up_write(&cmd->root_lock); | |
1240 | ||
1241 | return r; | |
1242 | } | |
1243 | ||
1244 | void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd, | |
1245 | struct dm_cache_statistics *stats) | |
1246 | { | |
1247 | down_read(&cmd->root_lock); | |
8c5008fa | 1248 | *stats = cmd->stats; |
c6b4fcba JT |
1249 | up_read(&cmd->root_lock); |
1250 | } | |
1251 | ||
1252 | void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd, | |
1253 | struct dm_cache_statistics *stats) | |
1254 | { | |
1255 | down_write(&cmd->root_lock); | |
8c5008fa | 1256 | cmd->stats = *stats; |
c6b4fcba JT |
1257 | up_write(&cmd->root_lock); |
1258 | } | |
1259 | ||
1260 | int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown) | |
1261 | { | |
1262 | int r; | |
1263 | flags_mutator mutator = (clean_shutdown ? set_clean_shutdown : | |
1264 | clear_clean_shutdown); | |
1265 | ||
1266 | down_write(&cmd->root_lock); | |
1267 | r = __commit_transaction(cmd, mutator); | |
1268 | if (r) | |
1269 | goto out; | |
1270 | ||
1271 | r = __begin_transaction(cmd); | |
1272 | ||
1273 | out: | |
1274 | up_write(&cmd->root_lock); | |
1275 | return r; | |
1276 | } | |
1277 | ||
1278 | int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, | |
1279 | dm_block_t *result) | |
1280 | { | |
1281 | int r = -EINVAL; | |
1282 | ||
1283 | down_read(&cmd->root_lock); | |
1284 | r = dm_sm_get_nr_free(cmd->metadata_sm, result); | |
1285 | up_read(&cmd->root_lock); | |
1286 | ||
1287 | return r; | |
1288 | } | |
1289 | ||
1290 | int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, | |
1291 | dm_block_t *result) | |
1292 | { | |
1293 | int r = -EINVAL; | |
1294 | ||
1295 | down_read(&cmd->root_lock); | |
1296 | r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); | |
1297 | up_read(&cmd->root_lock); | |
1298 | ||
1299 | return r; | |
1300 | } | |
1301 | ||
1302 | /*----------------------------------------------------------------*/ | |
1303 | ||
1304 | static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) | |
1305 | { | |
1306 | int r; | |
1307 | __le32 value; | |
1308 | size_t hint_size; | |
1309 | const char *policy_name = dm_cache_policy_get_name(policy); | |
4e7f506f | 1310 | const unsigned *policy_version = dm_cache_policy_get_version(policy); |
c6b4fcba JT |
1311 | |
1312 | if (!policy_name[0] || | |
1313 | (strlen(policy_name) > sizeof(cmd->policy_name) - 1)) | |
1314 | return -EINVAL; | |
1315 | ||
ea2dd8c1 | 1316 | if (!policy_unchanged(cmd, policy)) { |
c6b4fcba | 1317 | strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name)); |
4e7f506f | 1318 | memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version)); |
c6b4fcba JT |
1319 | |
1320 | hint_size = dm_cache_policy_get_hint_size(policy); | |
1321 | if (!hint_size) | |
1322 | return 0; /* short-circuit hints initialization */ | |
1323 | cmd->policy_hint_size = hint_size; | |
1324 | ||
1325 | if (cmd->hint_root) { | |
1326 | r = dm_array_del(&cmd->hint_info, cmd->hint_root); | |
1327 | if (r) | |
1328 | return r; | |
1329 | } | |
1330 | ||
1331 | r = dm_array_empty(&cmd->hint_info, &cmd->hint_root); | |
1332 | if (r) | |
1333 | return r; | |
1334 | ||
1335 | value = cpu_to_le32(0); | |
1336 | __dm_bless_for_disk(&value); | |
1337 | r = dm_array_resize(&cmd->hint_info, cmd->hint_root, 0, | |
1338 | from_cblock(cmd->cache_blocks), | |
1339 | &value, &cmd->hint_root); | |
1340 | if (r) | |
1341 | return r; | |
1342 | } | |
1343 | ||
1344 | return 0; | |
1345 | } | |
1346 | ||
0596661f | 1347 | static int save_hint(void *context, dm_cblock_t cblock, dm_oblock_t oblock, uint32_t hint) |
c6b4fcba | 1348 | { |
0596661f JT |
1349 | struct dm_cache_metadata *cmd = context; |
1350 | __le32 value = cpu_to_le32(hint); | |
c6b4fcba JT |
1351 | int r; |
1352 | ||
c6b4fcba JT |
1353 | __dm_bless_for_disk(&value); |
1354 | ||
1355 | r = dm_array_set_value(&cmd->hint_info, cmd->hint_root, | |
1356 | from_cblock(cblock), &value, &cmd->hint_root); | |
1357 | cmd->changed = true; | |
1358 | ||
1359 | return r; | |
1360 | } | |
1361 | ||
0596661f | 1362 | static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) |
c6b4fcba JT |
1363 | { |
1364 | int r; | |
1365 | ||
0596661f JT |
1366 | r = begin_hints(cmd, policy); |
1367 | if (r) { | |
1368 | DMERR("begin_hints failed"); | |
1369 | return r; | |
1370 | } | |
1371 | ||
1372 | return policy_walk_mappings(policy, save_hint, cmd); | |
1373 | } | |
1374 | ||
1375 | int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) | |
1376 | { | |
1377 | int r; | |
c6b4fcba JT |
1378 | |
1379 | down_write(&cmd->root_lock); | |
0596661f | 1380 | r = write_hints(cmd, policy); |
c6b4fcba JT |
1381 | up_write(&cmd->root_lock); |
1382 | ||
1383 | return r; | |
1384 | } | |
2ee57d58 JT |
1385 | |
1386 | int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result) | |
1387 | { | |
1388 | return blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result); | |
1389 | } |