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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / md / dm-cache-metadata.c
blob151aa95775be2daee11c7721eb62dde28ec702b1
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 #include <linux/refcount.h>
17
18 /*----------------------------------------------------------------*/
19
20 #define DM_MSG_PREFIX "cache metadata"
21
22 #define CACHE_SUPERBLOCK_MAGIC 06142003
23 #define CACHE_SUPERBLOCK_LOCATION 0
24
25 /*
26 * defines a range of metadata versions that this module can handle.
27 */
28 #define MIN_CACHE_VERSION 1
29 #define MAX_CACHE_VERSION 2
30
31 /*
32 * 3 for btree insert +
33 * 2 for btree lookup used within space map
34 */
35 #define CACHE_MAX_CONCURRENT_LOCKS 5
36 #define SPACE_MAP_ROOT_SIZE 128
37
38 enum superblock_flag_bits {
39 /* for spotting crashes that would invalidate the dirty bitset */
40 CLEAN_SHUTDOWN,
41 /* metadata must be checked using the tools */
42 NEEDS_CHECK,
43 };
44
45 /*
46 * Each mapping from cache block -> origin block carries a set of flags.
47 */
48 enum mapping_bits {
49 /*
50 * A valid mapping. Because we're using an array we clear this
51 * flag for an non existant mapping.
52 */
53 M_VALID = 1,
54
55 /*
56 * The data on the cache is different from that on the origin.
57 * This flag is only used by metadata format 1.
58 */
59 M_DIRTY = 2
60 };
61
62 struct cache_disk_superblock {
63 __le32 csum;
64 __le32 flags;
65 __le64 blocknr;
66
67 __u8 uuid[16];
68 __le64 magic;
69 __le32 version;
70
71 __u8 policy_name[CACHE_POLICY_NAME_SIZE];
72 __le32 policy_hint_size;
73
74 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
75 __le64 mapping_root;
76 __le64 hint_root;
77
78 __le64 discard_root;
79 __le64 discard_block_size;
80 __le64 discard_nr_blocks;
81
82 __le32 data_block_size;
83 __le32 metadata_block_size;
84 __le32 cache_blocks;
85
86 __le32 compat_flags;
87 __le32 compat_ro_flags;
88 __le32 incompat_flags;
89
90 __le32 read_hits;
91 __le32 read_misses;
92 __le32 write_hits;
93 __le32 write_misses;
94
95 __le32 policy_version[CACHE_POLICY_VERSION_SIZE];
96
97 /*
98 * Metadata format 2 fields.
99 */
100 __le64 dirty_root;
101 } __packed;
102
103 struct dm_cache_metadata {
104 refcount_t ref_count;
105 struct list_head list;
106
107 unsigned version;
108 struct block_device *bdev;
109 struct dm_block_manager *bm;
110 struct dm_space_map *metadata_sm;
111 struct dm_transaction_manager *tm;
112
113 struct dm_array_info info;
114 struct dm_array_info hint_info;
115 struct dm_disk_bitset discard_info;
116
117 struct rw_semaphore root_lock;
118 unsigned long flags;
119 dm_block_t root;
120 dm_block_t hint_root;
121 dm_block_t discard_root;
122
123 sector_t discard_block_size;
124 dm_dblock_t discard_nr_blocks;
125
126 sector_t data_block_size;
127 dm_cblock_t cache_blocks;
128 bool changed:1;
129 bool clean_when_opened:1;
130
131 char policy_name[CACHE_POLICY_NAME_SIZE];
132 unsigned policy_version[CACHE_POLICY_VERSION_SIZE];
133 size_t policy_hint_size;
134 struct dm_cache_statistics stats;
135
136 /*
137 * Reading the space map root can fail, so we read it into this
138 * buffer before the superblock is locked and updated.
139 */
140 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
141
142 /*
143 * Set if a transaction has to be aborted but the attempt to roll
144 * back to the previous (good) transaction failed. The only
145 * metadata operation permissible in this state is the closing of
146 * the device.
147 */
148 bool fail_io:1;
149
150 /*
151 * Metadata format 2 fields.
152 */
153 dm_block_t dirty_root;
154 struct dm_disk_bitset dirty_info;
155
156 /*
157 * These structures are used when loading metadata. They're too
158 * big to put on the stack.
159 */
160 struct dm_array_cursor mapping_cursor;
161 struct dm_array_cursor hint_cursor;
162 struct dm_bitset_cursor dirty_cursor;
163 };
164
165 /*-------------------------------------------------------------------
166 * superblock validator
167 *-----------------------------------------------------------------*/
168
169 #define SUPERBLOCK_CSUM_XOR 9031977
170
171 static void sb_prepare_for_write(struct dm_block_validator *v,
172 struct dm_block *b,
173 size_t sb_block_size)
174 {
175 struct cache_disk_superblock *disk_super = dm_block_data(b);
176
177 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
178 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
179 sb_block_size - sizeof(__le32),
180 SUPERBLOCK_CSUM_XOR));
181 }
182
183 static int check_metadata_version(struct cache_disk_superblock *disk_super)
184 {
185 uint32_t metadata_version = le32_to_cpu(disk_super->version);
186
187 if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) {
188 DMERR("Cache metadata version %u found, but only versions between %u and %u supported.",
189 metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION);
190 return -EINVAL;
191 }
192
193 return 0;
194 }
195
196 static int sb_check(struct dm_block_validator *v,
197 struct dm_block *b,
198 size_t sb_block_size)
199 {
200 struct cache_disk_superblock *disk_super = dm_block_data(b);
201 __le32 csum_le;
202
203 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
204 DMERR("sb_check failed: blocknr %llu: wanted %llu",
205 le64_to_cpu(disk_super->blocknr),
206 (unsigned long long)dm_block_location(b));
207 return -ENOTBLK;
208 }
209
210 if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) {
211 DMERR("sb_check failed: magic %llu: wanted %llu",
212 le64_to_cpu(disk_super->magic),
213 (unsigned long long)CACHE_SUPERBLOCK_MAGIC);
214 return -EILSEQ;
215 }
216
217 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
218 sb_block_size - sizeof(__le32),
219 SUPERBLOCK_CSUM_XOR));
220 if (csum_le != disk_super->csum) {
221 DMERR("sb_check failed: csum %u: wanted %u",
222 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
223 return -EILSEQ;
224 }
225
226 return check_metadata_version(disk_super);
227 }
228
229 static struct dm_block_validator sb_validator = {
230 .name = "superblock",
231 .prepare_for_write = sb_prepare_for_write,
232 .check = sb_check
233 };
234
235 /*----------------------------------------------------------------*/
236
237 static int superblock_read_lock(struct dm_cache_metadata *cmd,
238 struct dm_block **sblock)
239 {
240 return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
241 &sb_validator, sblock);
242 }
243
244 static int superblock_lock_zero(struct dm_cache_metadata *cmd,
245 struct dm_block **sblock)
246 {
247 return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
248 &sb_validator, sblock);
249 }
250
251 static int superblock_lock(struct dm_cache_metadata *cmd,
252 struct dm_block **sblock)
253 {
254 return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
255 &sb_validator, sblock);
256 }
257
258 /*----------------------------------------------------------------*/
259
260 static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
261 {
262 int r;
263 unsigned i;
264 struct dm_block *b;
265 __le64 *data_le, zero = cpu_to_le64(0);
266 unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
267
268 /*
269 * We can't use a validator here - it may be all zeroes.
270 */
271 r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b);
272 if (r)
273 return r;
274
275 data_le = dm_block_data(b);
276 *result = true;
277 for (i = 0; i < sb_block_size; i++) {
278 if (data_le[i] != zero) {
279 *result = false;
280 break;
281 }
282 }
283
284 dm_bm_unlock(b);
285
286 return 0;
287 }
288
289 static void __setup_mapping_info(struct dm_cache_metadata *cmd)
290 {
291 struct dm_btree_value_type vt;
292
293 vt.context = NULL;
294 vt.size = sizeof(__le64);
295 vt.inc = NULL;
296 vt.dec = NULL;
297 vt.equal = NULL;
298 dm_array_info_init(&cmd->info, cmd->tm, &vt);
299
300 if (cmd->policy_hint_size) {
301 vt.size = sizeof(__le32);
302 dm_array_info_init(&cmd->hint_info, cmd->tm, &vt);
303 }
304 }
305
306 static int __save_sm_root(struct dm_cache_metadata *cmd)
307 {
308 int r;
309 size_t metadata_len;
310
311 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
312 if (r < 0)
313 return r;
314
315 return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
316 metadata_len);
317 }
318
319 static void __copy_sm_root(struct dm_cache_metadata *cmd,
320 struct cache_disk_superblock *disk_super)
321 {
322 memcpy(&disk_super->metadata_space_map_root,
323 &cmd->metadata_space_map_root,
324 sizeof(cmd->metadata_space_map_root));
325 }
326
327 static bool separate_dirty_bits(struct dm_cache_metadata *cmd)
328 {
329 return cmd->version >= 2;
330 }
331
332 static int __write_initial_superblock(struct dm_cache_metadata *cmd)
333 {
334 int r;
335 struct dm_block *sblock;
336 struct cache_disk_superblock *disk_super;
337 sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
338
339 /* FIXME: see if we can lose the max sectors limit */
340 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
341 bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
342
343 r = dm_tm_pre_commit(cmd->tm);
344 if (r < 0)
345 return r;
346
347 /*
348 * dm_sm_copy_root() can fail. So we need to do it before we start
349 * updating the superblock.
350 */
351 r = __save_sm_root(cmd);
352 if (r)
353 return r;
354
355 r = superblock_lock_zero(cmd, &sblock);
356 if (r)
357 return r;
358
359 disk_super = dm_block_data(sblock);
360 disk_super->flags = 0;
361 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
362 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
363 disk_super->version = cpu_to_le32(cmd->version);
364 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
365 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
366 disk_super->policy_hint_size = cpu_to_le32(0);
367
368 __copy_sm_root(cmd, disk_super);
369
370 disk_super->mapping_root = cpu_to_le64(cmd->root);
371 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
372 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
373 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
374 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
375 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE);
376 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
377 disk_super->cache_blocks = cpu_to_le32(0);
378
379 disk_super->read_hits = cpu_to_le32(0);
380 disk_super->read_misses = cpu_to_le32(0);
381 disk_super->write_hits = cpu_to_le32(0);
382 disk_super->write_misses = cpu_to_le32(0);
383
384 if (separate_dirty_bits(cmd))
385 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
386
387 return dm_tm_commit(cmd->tm, sblock);
388 }
389
390 static int __format_metadata(struct dm_cache_metadata *cmd)
391 {
392 int r;
393
394 r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
395 &cmd->tm, &cmd->metadata_sm);
396 if (r < 0) {
397 DMERR("tm_create_with_sm failed");
398 return r;
399 }
400
401 __setup_mapping_info(cmd);
402
403 r = dm_array_empty(&cmd->info, &cmd->root);
404 if (r < 0)
405 goto bad;
406
407 if (separate_dirty_bits(cmd)) {
408 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info);
409 r = dm_bitset_empty(&cmd->dirty_info, &cmd->dirty_root);
410 if (r < 0)
411 goto bad;
412 }
413
414 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
415 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root);
416 if (r < 0)
417 goto bad;
418
419 cmd->discard_block_size = 0;
420 cmd->discard_nr_blocks = 0;
421
422 r = __write_initial_superblock(cmd);
423 if (r)
424 goto bad;
425
426 cmd->clean_when_opened = true;
427 return 0;
428
429 bad:
430 dm_tm_destroy(cmd->tm);
431 dm_sm_destroy(cmd->metadata_sm);
432
433 return r;
434 }
435
436 static int __check_incompat_features(struct cache_disk_superblock *disk_super,
437 struct dm_cache_metadata *cmd)
438 {
439 uint32_t incompat_flags, features;
440
441 incompat_flags = le32_to_cpu(disk_super->incompat_flags);
442 features = incompat_flags & ~DM_CACHE_FEATURE_INCOMPAT_SUPP;
443 if (features) {
444 DMERR("could not access metadata due to unsupported optional features (%lx).",
445 (unsigned long)features);
446 return -EINVAL;
447 }
448
449 /*
450 * Check for read-only metadata to skip the following RDWR checks.
451 */
452 if (get_disk_ro(cmd->bdev->bd_disk))
453 return 0;
454
455 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP;
456 if (features) {
457 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
458 (unsigned long)features);
459 return -EINVAL;
460 }
461
462 return 0;
463 }
464
465 static int __open_metadata(struct dm_cache_metadata *cmd)
466 {
467 int r;
468 struct dm_block *sblock;
469 struct cache_disk_superblock *disk_super;
470 unsigned long sb_flags;
471
472 r = superblock_read_lock(cmd, &sblock);
473 if (r < 0) {
474 DMERR("couldn't read lock superblock");
475 return r;
476 }
477
478 disk_super = dm_block_data(sblock);
479
480 /* Verify the data block size hasn't changed */
481 if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) {
482 DMERR("changing the data block size (from %u to %llu) is not supported",
483 le32_to_cpu(disk_super->data_block_size),
484 (unsigned long long)cmd->data_block_size);
485 r = -EINVAL;
486 goto bad;
487 }
488
489 r = __check_incompat_features(disk_super, cmd);
490 if (r < 0)
491 goto bad;
492
493 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
494 disk_super->metadata_space_map_root,
495 sizeof(disk_super->metadata_space_map_root),
496 &cmd->tm, &cmd->metadata_sm);
497 if (r < 0) {
498 DMERR("tm_open_with_sm failed");
499 goto bad;
500 }
501
502 __setup_mapping_info(cmd);
503 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info);
504 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
505 sb_flags = le32_to_cpu(disk_super->flags);
506 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
507 dm_bm_unlock(sblock);
508
509 return 0;
510
511 bad:
512 dm_bm_unlock(sblock);
513 return r;
514 }
515
516 static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
517 bool format_device)
518 {
519 int r;
520 bool unformatted = false;
521
522 r = __superblock_all_zeroes(cmd->bm, &unformatted);
523 if (r)
524 return r;
525
526 if (unformatted)
527 return format_device ? __format_metadata(cmd) : -EPERM;
528
529 return __open_metadata(cmd);
530 }
531
532 static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
533 bool may_format_device)
534 {
535 int r;
536 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
537 CACHE_MAX_CONCURRENT_LOCKS);
538 if (IS_ERR(cmd->bm)) {
539 DMERR("could not create block manager");
540 return PTR_ERR(cmd->bm);
541 }
542
543 r = __open_or_format_metadata(cmd, may_format_device);
544 if (r)
545 dm_block_manager_destroy(cmd->bm);
546
547 return r;
548 }
549
550 static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd)
551 {
552 dm_sm_destroy(cmd->metadata_sm);
553 dm_tm_destroy(cmd->tm);
554 dm_block_manager_destroy(cmd->bm);
555 }
556
557 typedef unsigned long (*flags_mutator)(unsigned long);
558
559 static void update_flags(struct cache_disk_superblock *disk_super,
560 flags_mutator mutator)
561 {
562 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
563 disk_super->flags = cpu_to_le32(sb_flags);
564 }
565
566 static unsigned long set_clean_shutdown(unsigned long flags)
567 {
568 set_bit(CLEAN_SHUTDOWN, &flags);
569 return flags;
570 }
571
572 static unsigned long clear_clean_shutdown(unsigned long flags)
573 {
574 clear_bit(CLEAN_SHUTDOWN, &flags);
575 return flags;
576 }
577
578 static void read_superblock_fields(struct dm_cache_metadata *cmd,
579 struct cache_disk_superblock *disk_super)
580 {
581 cmd->version = le32_to_cpu(disk_super->version);
582 cmd->flags = le32_to_cpu(disk_super->flags);
583 cmd->root = le64_to_cpu(disk_super->mapping_root);
584 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
585 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
586 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
587 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
588 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
589 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
590 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
591 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
592 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
593 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
594 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
595
596 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
597 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
598 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
599 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
600
601 if (separate_dirty_bits(cmd))
602 cmd->dirty_root = le64_to_cpu(disk_super->dirty_root);
603
604 cmd->changed = false;
605 }
606
607 /*
608 * The mutator updates the superblock flags.
609 */
610 static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
611 flags_mutator mutator)
612 {
613 int r;
614 struct cache_disk_superblock *disk_super;
615 struct dm_block *sblock;
616
617 r = superblock_lock(cmd, &sblock);
618 if (r)
619 return r;
620
621 disk_super = dm_block_data(sblock);
622 update_flags(disk_super, mutator);
623 read_superblock_fields(cmd, disk_super);
624 dm_bm_unlock(sblock);
625
626 return dm_bm_flush(cmd->bm);
627 }
628
629 static int __begin_transaction(struct dm_cache_metadata *cmd)
630 {
631 int r;
632 struct cache_disk_superblock *disk_super;
633 struct dm_block *sblock;
634
635 /*
636 * We re-read the superblock every time. Shouldn't need to do this
637 * really.
638 */
639 r = superblock_read_lock(cmd, &sblock);
640 if (r)
641 return r;
642
643 disk_super = dm_block_data(sblock);
644 read_superblock_fields(cmd, disk_super);
645 dm_bm_unlock(sblock);
646
647 return 0;
648 }
649
650 static int __commit_transaction(struct dm_cache_metadata *cmd,
651 flags_mutator mutator)
652 {
653 int r;
654 struct cache_disk_superblock *disk_super;
655 struct dm_block *sblock;
656
657 /*
658 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
659 */
660 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
661
662 if (separate_dirty_bits(cmd)) {
663 r = dm_bitset_flush(&cmd->dirty_info, cmd->dirty_root,
664 &cmd->dirty_root);
665 if (r)
666 return r;
667 }
668
669 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
670 &cmd->discard_root);
671 if (r)
672 return r;
673
674 r = dm_tm_pre_commit(cmd->tm);
675 if (r < 0)
676 return r;
677
678 r = __save_sm_root(cmd);
679 if (r)
680 return r;
681
682 r = superblock_lock(cmd, &sblock);
683 if (r)
684 return r;
685
686 disk_super = dm_block_data(sblock);
687
688 disk_super->flags = cpu_to_le32(cmd->flags);
689 if (mutator)
690 update_flags(disk_super, mutator);
691
692 disk_super->mapping_root = cpu_to_le64(cmd->root);
693 if (separate_dirty_bits(cmd))
694 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
695 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
696 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
697 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
698 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
699 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
700 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
701 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
702 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
703 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
704 disk_super->policy_hint_size = cpu_to_le32(cmd->policy_hint_size);
705
706 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
707 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
708 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
709 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
710 __copy_sm_root(cmd, disk_super);
711
712 return dm_tm_commit(cmd->tm, sblock);
713 }
714
715 /*----------------------------------------------------------------*/
716
717 /*
718 * The mappings are held in a dm-array that has 64-bit values stored in
719 * little-endian format. The index is the cblock, the high 48bits of the
720 * value are the oblock and the low 16 bit the flags.
721 */
722 #define FLAGS_MASK ((1 << 16) - 1)
723
724 static __le64 pack_value(dm_oblock_t block, unsigned flags)
725 {
726 uint64_t value = from_oblock(block);
727 value <<= 16;
728 value = value | (flags & FLAGS_MASK);
729 return cpu_to_le64(value);
730 }
731
732 static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
733 {
734 uint64_t value = le64_to_cpu(value_le);
735 uint64_t b = value >> 16;
736 *block = to_oblock(b);
737 *flags = value & FLAGS_MASK;
738 }
739
740 /*----------------------------------------------------------------*/
741
742 static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
743 sector_t data_block_size,
744 bool may_format_device,
745 size_t policy_hint_size,
746 unsigned metadata_version)
747 {
748 int r;
749 struct dm_cache_metadata *cmd;
750
751 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
752 if (!cmd) {
753 DMERR("could not allocate metadata struct");
754 return ERR_PTR(-ENOMEM);
755 }
756
757 cmd->version = metadata_version;
758 refcount_set(&cmd->ref_count, 1);
759 init_rwsem(&cmd->root_lock);
760 cmd->bdev = bdev;
761 cmd->data_block_size = data_block_size;
762 cmd->cache_blocks = 0;
763 cmd->policy_hint_size = policy_hint_size;
764 cmd->changed = true;
765 cmd->fail_io = false;
766
767 r = __create_persistent_data_objects(cmd, may_format_device);
768 if (r) {
769 kfree(cmd);
770 return ERR_PTR(r);
771 }
772
773 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
774 if (r < 0) {
775 dm_cache_metadata_close(cmd);
776 return ERR_PTR(r);
777 }
778
779 return cmd;
780 }
781
782 /*
783 * We keep a little list of ref counted metadata objects to prevent two
784 * different target instances creating separate bufio instances. This is
785 * an issue if a table is reloaded before the suspend.
786 */
787 static DEFINE_MUTEX(table_lock);
788 static LIST_HEAD(table);
789
790 static struct dm_cache_metadata *lookup(struct block_device *bdev)
791 {
792 struct dm_cache_metadata *cmd;
793
794 list_for_each_entry(cmd, &table, list)
795 if (cmd->bdev == bdev) {
796 refcount_inc(&cmd->ref_count);
797 return cmd;
798 }
799
800 return NULL;
801 }
802
803 static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev,
804 sector_t data_block_size,
805 bool may_format_device,
806 size_t policy_hint_size,
807 unsigned metadata_version)
808 {
809 struct dm_cache_metadata *cmd, *cmd2;
810
811 mutex_lock(&table_lock);
812 cmd = lookup(bdev);
813 mutex_unlock(&table_lock);
814
815 if (cmd)
816 return cmd;
817
818 cmd = metadata_open(bdev, data_block_size, may_format_device,
819 policy_hint_size, metadata_version);
820 if (!IS_ERR(cmd)) {
821 mutex_lock(&table_lock);
822 cmd2 = lookup(bdev);
823 if (cmd2) {
824 mutex_unlock(&table_lock);
825 __destroy_persistent_data_objects(cmd);
826 kfree(cmd);
827 return cmd2;
828 }
829 list_add(&cmd->list, &table);
830 mutex_unlock(&table_lock);
831 }
832
833 return cmd;
834 }
835
836 static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size)
837 {
838 if (cmd->data_block_size != data_block_size) {
839 DMERR("data_block_size (%llu) different from that in metadata (%llu)",
840 (unsigned long long) data_block_size,
841 (unsigned long long) cmd->data_block_size);
842 return false;
843 }
844
845 return true;
846 }
847
848 struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
849 sector_t data_block_size,
850 bool may_format_device,
851 size_t policy_hint_size,
852 unsigned metadata_version)
853 {
854 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, may_format_device,
855 policy_hint_size, metadata_version);
856
857 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) {
858 dm_cache_metadata_close(cmd);
859 return ERR_PTR(-EINVAL);
860 }
861
862 return cmd;
863 }
864
865 void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
866 {
867 if (refcount_dec_and_test(&cmd->ref_count)) {
868 mutex_lock(&table_lock);
869 list_del(&cmd->list);
870 mutex_unlock(&table_lock);
871
872 if (!cmd->fail_io)
873 __destroy_persistent_data_objects(cmd);
874 kfree(cmd);
875 }
876 }
877
878 /*
879 * Checks that the given cache block is either unmapped or clean.
880 */
881 static int block_clean_combined_dirty(struct dm_cache_metadata *cmd, dm_cblock_t b,
882 bool *result)
883 {
884 int r;
885 __le64 value;
886 dm_oblock_t ob;
887 unsigned flags;
888
889 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
890 if (r)
891 return r;
892
893 unpack_value(value, &ob, &flags);
894 *result = !((flags & M_VALID) && (flags & M_DIRTY));
895
896 return 0;
897 }
898
899 static int blocks_are_clean_combined_dirty(struct dm_cache_metadata *cmd,
900 dm_cblock_t begin, dm_cblock_t end,
901 bool *result)
902 {
903 int r;
904 *result = true;
905
906 while (begin != end) {
907 r = block_clean_combined_dirty(cmd, begin, result);
908 if (r) {
909 DMERR("block_clean_combined_dirty failed");
910 return r;
911 }
912
913 if (!*result) {
914 DMERR("cache block %llu is dirty",
915 (unsigned long long) from_cblock(begin));
916 return 0;
917 }
918
919 begin = to_cblock(from_cblock(begin) + 1);
920 }
921
922 return 0;
923 }
924
925 static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd,
926 dm_cblock_t begin, dm_cblock_t end,
927 bool *result)
928 {
929 int r;
930 bool dirty_flag;
931 *result = true;
932
933 if (from_cblock(cmd->cache_blocks) == 0)
934 /* Nothing to do */
935 return 0;
936
937 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
938 from_cblock(cmd->cache_blocks), &cmd->dirty_cursor);
939 if (r) {
940 DMERR("%s: dm_bitset_cursor_begin for dirty failed", __func__);
941 return r;
942 }
943
944 r = dm_bitset_cursor_skip(&cmd->dirty_cursor, from_cblock(begin));
945 if (r) {
946 DMERR("%s: dm_bitset_cursor_skip for dirty failed", __func__);
947 dm_bitset_cursor_end(&cmd->dirty_cursor);
948 return r;
949 }
950
951 while (begin != end) {
952 /*
953 * We assume that unmapped blocks have their dirty bit
954 * cleared.
955 */
956 dirty_flag = dm_bitset_cursor_get_value(&cmd->dirty_cursor);
957 if (dirty_flag) {
958 DMERR("%s: cache block %llu is dirty", __func__,
959 (unsigned long long) from_cblock(begin));
960 dm_bitset_cursor_end(&cmd->dirty_cursor);
961 *result = false;
962 return 0;
963 }
964
965 begin = to_cblock(from_cblock(begin) + 1);
966 if (begin == end)
967 break;
968
969 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
970 if (r) {
971 DMERR("%s: dm_bitset_cursor_next for dirty failed", __func__);
972 dm_bitset_cursor_end(&cmd->dirty_cursor);
973 return r;
974 }
975 }
976
977 dm_bitset_cursor_end(&cmd->dirty_cursor);
978
979 return 0;
980 }
981
982 static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
983 dm_cblock_t begin, dm_cblock_t end,
984 bool *result)
985 {
986 if (separate_dirty_bits(cmd))
987 return blocks_are_clean_separate_dirty(cmd, begin, end, result);
988 else
989 return blocks_are_clean_combined_dirty(cmd, begin, end, result);
990 }
991
992 static bool cmd_write_lock(struct dm_cache_metadata *cmd)
993 {
994 down_write(&cmd->root_lock);
995 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
996 up_write(&cmd->root_lock);
997 return false;
998 }
999 return true;
1000 }
1001
1002 #define WRITE_LOCK(cmd) \
1003 do { \
1004 if (!cmd_write_lock((cmd))) \
1005 return -EINVAL; \
1006 } while(0)
1007
1008 #define WRITE_LOCK_VOID(cmd) \
1009 do { \
1010 if (!cmd_write_lock((cmd))) \
1011 return; \
1012 } while(0)
1013
1014 #define WRITE_UNLOCK(cmd) \
1015 up_write(&(cmd)->root_lock)
1016
1017 static bool cmd_read_lock(struct dm_cache_metadata *cmd)
1018 {
1019 down_read(&cmd->root_lock);
1020 if (cmd->fail_io) {
1021 up_read(&cmd->root_lock);
1022 return false;
1023 }
1024 return true;
1025 }
1026
1027 #define READ_LOCK(cmd) \
1028 do { \
1029 if (!cmd_read_lock((cmd))) \
1030 return -EINVAL; \
1031 } while(0)
1032
1033 #define READ_LOCK_VOID(cmd) \
1034 do { \
1035 if (!cmd_read_lock((cmd))) \
1036 return; \
1037 } while(0)
1038
1039 #define READ_UNLOCK(cmd) \
1040 up_read(&(cmd)->root_lock)
1041
1042 int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
1043 {
1044 int r;
1045 bool clean;
1046 __le64 null_mapping = pack_value(0, 0);
1047
1048 WRITE_LOCK(cmd);
1049 __dm_bless_for_disk(&null_mapping);
1050
1051 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
1052 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
1053 if (r) {
1054 __dm_unbless_for_disk(&null_mapping);
1055 goto out;
1056 }
1057
1058 if (!clean) {
1059 DMERR("unable to shrink cache due to dirty blocks");
1060 r = -EINVAL;
1061 __dm_unbless_for_disk(&null_mapping);
1062 goto out;
1063 }
1064 }
1065
1066 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
1067 from_cblock(new_cache_size),
1068 &null_mapping, &cmd->root);
1069 if (r)
1070 goto out;
1071
1072 if (separate_dirty_bits(cmd)) {
1073 r = dm_bitset_resize(&cmd->dirty_info, cmd->dirty_root,
1074 from_cblock(cmd->cache_blocks), from_cblock(new_cache_size),
1075 false, &cmd->dirty_root);
1076 if (r)
1077 goto out;
1078 }
1079
1080 cmd->cache_blocks = new_cache_size;
1081 cmd->changed = true;
1082
1083 out:
1084 WRITE_UNLOCK(cmd);
1085
1086 return r;
1087 }
1088
1089 int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
1090 sector_t discard_block_size,
1091 dm_dblock_t new_nr_entries)
1092 {
1093 int r;
1094
1095 WRITE_LOCK(cmd);
1096 r = dm_bitset_resize(&cmd->discard_info,
1097 cmd->discard_root,
1098 from_dblock(cmd->discard_nr_blocks),
1099 from_dblock(new_nr_entries),
1100 false, &cmd->discard_root);
1101 if (!r) {
1102 cmd->discard_block_size = discard_block_size;
1103 cmd->discard_nr_blocks = new_nr_entries;
1104 }
1105
1106 cmd->changed = true;
1107 WRITE_UNLOCK(cmd);
1108
1109 return r;
1110 }
1111
1112 static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1113 {
1114 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
1115 from_dblock(b), &cmd->discard_root);
1116 }
1117
1118 static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1119 {
1120 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
1121 from_dblock(b), &cmd->discard_root);
1122 }
1123
1124 static int __discard(struct dm_cache_metadata *cmd,
1125 dm_dblock_t dblock, bool discard)
1126 {
1127 int r;
1128
1129 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
1130 if (r)
1131 return r;
1132
1133 cmd->changed = true;
1134 return 0;
1135 }
1136
1137 int dm_cache_set_discard(struct dm_cache_metadata *cmd,
1138 dm_dblock_t dblock, bool discard)
1139 {
1140 int r;
1141
1142 WRITE_LOCK(cmd);
1143 r = __discard(cmd, dblock, discard);
1144 WRITE_UNLOCK(cmd);
1145
1146 return r;
1147 }
1148
1149 static int __load_discards(struct dm_cache_metadata *cmd,
1150 load_discard_fn fn, void *context)
1151 {
1152 int r = 0;
1153 uint32_t b;
1154 struct dm_bitset_cursor c;
1155
1156 if (from_dblock(cmd->discard_nr_blocks) == 0)
1157 /* nothing to do */
1158 return 0;
1159
1160 if (cmd->clean_when_opened) {
1161 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, &cmd->discard_root);
1162 if (r)
1163 return r;
1164
1165 r = dm_bitset_cursor_begin(&cmd->discard_info, cmd->discard_root,
1166 from_dblock(cmd->discard_nr_blocks), &c);
1167 if (r)
1168 return r;
1169
1170 for (b = 0; ; b++) {
1171 r = fn(context, cmd->discard_block_size, to_dblock(b),
1172 dm_bitset_cursor_get_value(&c));
1173 if (r)
1174 break;
1175
1176 if (b >= (from_dblock(cmd->discard_nr_blocks) - 1))
1177 break;
1178
1179 r = dm_bitset_cursor_next(&c);
1180 if (r)
1181 break;
1182 }
1183
1184 dm_bitset_cursor_end(&c);
1185
1186 } else {
1187 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
1188 r = fn(context, cmd->discard_block_size, to_dblock(b), false);
1189 if (r)
1190 return r;
1191 }
1192 }
1193
1194 return r;
1195 }
1196
1197 int dm_cache_load_discards(struct dm_cache_metadata *cmd,
1198 load_discard_fn fn, void *context)
1199 {
1200 int r;
1201
1202 READ_LOCK(cmd);
1203 r = __load_discards(cmd, fn, context);
1204 READ_UNLOCK(cmd);
1205
1206 return r;
1207 }
1208
1209 int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result)
1210 {
1211 READ_LOCK(cmd);
1212 *result = cmd->cache_blocks;
1213 READ_UNLOCK(cmd);
1214
1215 return 0;
1216 }
1217
1218 static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1219 {
1220 int r;
1221 __le64 value = pack_value(0, 0);
1222
1223 __dm_bless_for_disk(&value);
1224 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1225 &value, &cmd->root);
1226 if (r)
1227 return r;
1228
1229 cmd->changed = true;
1230 return 0;
1231 }
1232
1233 int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1234 {
1235 int r;
1236
1237 WRITE_LOCK(cmd);
1238 r = __remove(cmd, cblock);
1239 WRITE_UNLOCK(cmd);
1240
1241 return r;
1242 }
1243
1244 static int __insert(struct dm_cache_metadata *cmd,
1245 dm_cblock_t cblock, dm_oblock_t oblock)
1246 {
1247 int r;
1248 __le64 value = pack_value(oblock, M_VALID);
1249 __dm_bless_for_disk(&value);
1250
1251 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1252 &value, &cmd->root);
1253 if (r)
1254 return r;
1255
1256 cmd->changed = true;
1257 return 0;
1258 }
1259
1260 int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
1261 dm_cblock_t cblock, dm_oblock_t oblock)
1262 {
1263 int r;
1264
1265 WRITE_LOCK(cmd);
1266 r = __insert(cmd, cblock, oblock);
1267 WRITE_UNLOCK(cmd);
1268
1269 return r;
1270 }
1271
1272 struct thunk {
1273 load_mapping_fn fn;
1274 void *context;
1275
1276 struct dm_cache_metadata *cmd;
1277 bool respect_dirty_flags;
1278 bool hints_valid;
1279 };
1280
1281 static bool policy_unchanged(struct dm_cache_metadata *cmd,
1282 struct dm_cache_policy *policy)
1283 {
1284 const char *policy_name = dm_cache_policy_get_name(policy);
1285 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1286 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
1287
1288 /*
1289 * Ensure policy names match.
1290 */
1291 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
1292 return false;
1293
1294 /*
1295 * Ensure policy major versions match.
1296 */
1297 if (cmd->policy_version[0] != policy_version[0])
1298 return false;
1299
1300 /*
1301 * Ensure policy hint sizes match.
1302 */
1303 if (cmd->policy_hint_size != policy_hint_size)
1304 return false;
1305
1306 return true;
1307 }
1308
1309 static bool hints_array_initialized(struct dm_cache_metadata *cmd)
1310 {
1311 return cmd->hint_root && cmd->policy_hint_size;
1312 }
1313
1314 static bool hints_array_available(struct dm_cache_metadata *cmd,
1315 struct dm_cache_policy *policy)
1316 {
1317 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
1318 hints_array_initialized(cmd);
1319 }
1320
1321 static int __load_mapping_v1(struct dm_cache_metadata *cmd,
1322 uint64_t cb, bool hints_valid,
1323 struct dm_array_cursor *mapping_cursor,
1324 struct dm_array_cursor *hint_cursor,
1325 load_mapping_fn fn, void *context)
1326 {
1327 int r = 0;
1328
1329 __le64 mapping;
1330 __le32 hint = 0;
1331
1332 __le64 *mapping_value_le;
1333 __le32 *hint_value_le;
1334
1335 dm_oblock_t oblock;
1336 unsigned flags;
1337 bool dirty = true;
1338
1339 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1340 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1341 unpack_value(mapping, &oblock, &flags);
1342
1343 if (flags & M_VALID) {
1344 if (hints_valid) {
1345 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1346 memcpy(&hint, hint_value_le, sizeof(hint));
1347 }
1348 if (cmd->clean_when_opened)
1349 dirty = flags & M_DIRTY;
1350
1351 r = fn(context, oblock, to_cblock(cb), dirty,
1352 le32_to_cpu(hint), hints_valid);
1353 if (r) {
1354 DMERR("policy couldn't load cache block %llu",
1355 (unsigned long long) from_cblock(to_cblock(cb)));
1356 }
1357 }
1358
1359 return r;
1360 }
1361
1362 static int __load_mapping_v2(struct dm_cache_metadata *cmd,
1363 uint64_t cb, bool hints_valid,
1364 struct dm_array_cursor *mapping_cursor,
1365 struct dm_array_cursor *hint_cursor,
1366 struct dm_bitset_cursor *dirty_cursor,
1367 load_mapping_fn fn, void *context)
1368 {
1369 int r = 0;
1370
1371 __le64 mapping;
1372 __le32 hint = 0;
1373
1374 __le64 *mapping_value_le;
1375 __le32 *hint_value_le;
1376
1377 dm_oblock_t oblock;
1378 unsigned flags;
1379 bool dirty = true;
1380
1381 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1382 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1383 unpack_value(mapping, &oblock, &flags);
1384
1385 if (flags & M_VALID) {
1386 if (hints_valid) {
1387 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1388 memcpy(&hint, hint_value_le, sizeof(hint));
1389 }
1390 if (cmd->clean_when_opened)
1391 dirty = dm_bitset_cursor_get_value(dirty_cursor);
1392
1393 r = fn(context, oblock, to_cblock(cb), dirty,
1394 le32_to_cpu(hint), hints_valid);
1395 if (r) {
1396 DMERR("policy couldn't load cache block %llu",
1397 (unsigned long long) from_cblock(to_cblock(cb)));
1398 }
1399 }
1400
1401 return r;
1402 }
1403
1404 static int __load_mappings(struct dm_cache_metadata *cmd,
1405 struct dm_cache_policy *policy,
1406 load_mapping_fn fn, void *context)
1407 {
1408 int r;
1409 uint64_t cb;
1410
1411 bool hints_valid = hints_array_available(cmd, policy);
1412
1413 if (from_cblock(cmd->cache_blocks) == 0)
1414 /* Nothing to do */
1415 return 0;
1416
1417 r = dm_array_cursor_begin(&cmd->info, cmd->root, &cmd->mapping_cursor);
1418 if (r)
1419 return r;
1420
1421 if (hints_valid) {
1422 r = dm_array_cursor_begin(&cmd->hint_info, cmd->hint_root, &cmd->hint_cursor);
1423 if (r) {
1424 dm_array_cursor_end(&cmd->mapping_cursor);
1425 return r;
1426 }
1427 }
1428
1429 if (separate_dirty_bits(cmd)) {
1430 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
1431 from_cblock(cmd->cache_blocks),
1432 &cmd->dirty_cursor);
1433 if (r) {
1434 dm_array_cursor_end(&cmd->hint_cursor);
1435 dm_array_cursor_end(&cmd->mapping_cursor);
1436 return r;
1437 }
1438 }
1439
1440 for (cb = 0; ; cb++) {
1441 if (separate_dirty_bits(cmd))
1442 r = __load_mapping_v2(cmd, cb, hints_valid,
1443 &cmd->mapping_cursor,
1444 &cmd->hint_cursor,
1445 &cmd->dirty_cursor,
1446 fn, context);
1447 else
1448 r = __load_mapping_v1(cmd, cb, hints_valid,
1449 &cmd->mapping_cursor, &cmd->hint_cursor,
1450 fn, context);
1451 if (r)
1452 goto out;
1453
1454 /*
1455 * We need to break out before we move the cursors.
1456 */
1457 if (cb >= (from_cblock(cmd->cache_blocks) - 1))
1458 break;
1459
1460 r = dm_array_cursor_next(&cmd->mapping_cursor);
1461 if (r) {
1462 DMERR("dm_array_cursor_next for mapping failed");
1463 goto out;
1464 }
1465
1466 if (hints_valid) {
1467 r = dm_array_cursor_next(&cmd->hint_cursor);
1468 if (r) {
1469 dm_array_cursor_end(&cmd->hint_cursor);
1470 hints_valid = false;
1471 }
1472 }
1473
1474 if (separate_dirty_bits(cmd)) {
1475 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
1476 if (r) {
1477 DMERR("dm_bitset_cursor_next for dirty failed");
1478 goto out;
1479 }
1480 }
1481 }
1482 out:
1483 dm_array_cursor_end(&cmd->mapping_cursor);
1484 if (hints_valid)
1485 dm_array_cursor_end(&cmd->hint_cursor);
1486
1487 if (separate_dirty_bits(cmd))
1488 dm_bitset_cursor_end(&cmd->dirty_cursor);
1489
1490 return r;
1491 }
1492
1493 int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
1494 struct dm_cache_policy *policy,
1495 load_mapping_fn fn, void *context)
1496 {
1497 int r;
1498
1499 READ_LOCK(cmd);
1500 r = __load_mappings(cmd, policy, fn, context);
1501 READ_UNLOCK(cmd);
1502
1503 return r;
1504 }
1505
1506 static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
1507 {
1508 int r = 0;
1509 __le64 value;
1510 dm_oblock_t oblock;
1511 unsigned flags;
1512
1513 memcpy(&value, leaf, sizeof(value));
1514 unpack_value(value, &oblock, &flags);
1515
1516 return r;
1517 }
1518
1519 static int __dump_mappings(struct dm_cache_metadata *cmd)
1520 {
1521 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
1522 }
1523
1524 void dm_cache_dump(struct dm_cache_metadata *cmd)
1525 {
1526 READ_LOCK_VOID(cmd);
1527 __dump_mappings(cmd);
1528 READ_UNLOCK(cmd);
1529 }
1530
1531 int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1532 {
1533 int r;
1534
1535 READ_LOCK(cmd);
1536 r = cmd->changed;
1537 READ_UNLOCK(cmd);
1538
1539 return r;
1540 }
1541
1542 static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1543 {
1544 int r;
1545 unsigned flags;
1546 dm_oblock_t oblock;
1547 __le64 value;
1548
1549 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1550 if (r)
1551 return r;
1552
1553 unpack_value(value, &oblock, &flags);
1554
1555 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1556 /* nothing to be done */
1557 return 0;
1558
1559 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
1560 __dm_bless_for_disk(&value);
1561
1562 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1563 &value, &cmd->root);
1564 if (r)
1565 return r;
1566
1567 cmd->changed = true;
1568 return 0;
1569
1570 }
1571
1572 static int __set_dirty_bits_v1(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1573 {
1574 int r;
1575 unsigned i;
1576 for (i = 0; i < nr_bits; i++) {
1577 r = __dirty(cmd, to_cblock(i), test_bit(i, bits));
1578 if (r)
1579 return r;
1580 }
1581
1582 return 0;
1583 }
1584
1585 static int is_dirty_callback(uint32_t index, bool *value, void *context)
1586 {
1587 unsigned long *bits = context;
1588 *value = test_bit(index, bits);
1589 return 0;
1590 }
1591
1592 static int __set_dirty_bits_v2(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1593 {
1594 int r = 0;
1595
1596 /* nr_bits is really just a sanity check */
1597 if (nr_bits != from_cblock(cmd->cache_blocks)) {
1598 DMERR("dirty bitset is wrong size");
1599 return -EINVAL;
1600 }
1601
1602 r = dm_bitset_del(&cmd->dirty_info, cmd->dirty_root);
1603 if (r)
1604 return r;
1605
1606 cmd->changed = true;
1607 return dm_bitset_new(&cmd->dirty_info, &cmd->dirty_root, nr_bits, is_dirty_callback, bits);
1608 }
1609
1610 int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd,
1611 unsigned nr_bits,
1612 unsigned long *bits)
1613 {
1614 int r;
1615
1616 WRITE_LOCK(cmd);
1617 if (separate_dirty_bits(cmd))
1618 r = __set_dirty_bits_v2(cmd, nr_bits, bits);
1619 else
1620 r = __set_dirty_bits_v1(cmd, nr_bits, bits);
1621 WRITE_UNLOCK(cmd);
1622
1623 return r;
1624 }
1625
1626 void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1627 struct dm_cache_statistics *stats)
1628 {
1629 READ_LOCK_VOID(cmd);
1630 *stats = cmd->stats;
1631 READ_UNLOCK(cmd);
1632 }
1633
1634 void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1635 struct dm_cache_statistics *stats)
1636 {
1637 WRITE_LOCK_VOID(cmd);
1638 cmd->stats = *stats;
1639 WRITE_UNLOCK(cmd);
1640 }
1641
1642 int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1643 {
1644 int r = -EINVAL;
1645 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1646 clear_clean_shutdown);
1647
1648 WRITE_LOCK(cmd);
1649 if (cmd->fail_io)
1650 goto out;
1651
1652 r = __commit_transaction(cmd, mutator);
1653 if (r)
1654 goto out;
1655
1656 r = __begin_transaction(cmd);
1657 out:
1658 WRITE_UNLOCK(cmd);
1659 return r;
1660 }
1661
1662 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1663 dm_block_t *result)
1664 {
1665 int r = -EINVAL;
1666
1667 READ_LOCK(cmd);
1668 if (!cmd->fail_io)
1669 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1670 READ_UNLOCK(cmd);
1671
1672 return r;
1673 }
1674
1675 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1676 dm_block_t *result)
1677 {
1678 int r = -EINVAL;
1679
1680 READ_LOCK(cmd);
1681 if (!cmd->fail_io)
1682 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1683 READ_UNLOCK(cmd);
1684
1685 return r;
1686 }
1687
1688 /*----------------------------------------------------------------*/
1689
1690 static int get_hint(uint32_t index, void *value_le, void *context)
1691 {
1692 uint32_t value;
1693 struct dm_cache_policy *policy = context;
1694
1695 value = policy_get_hint(policy, to_cblock(index));
1696 *((__le32 *) value_le) = cpu_to_le32(value);
1697
1698 return 0;
1699 }
1700
1701 /*
1702 * It's quicker to always delete the hint array, and recreate with
1703 * dm_array_new().
1704 */
1705 static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1706 {
1707 int r;
1708 size_t hint_size;
1709 const char *policy_name = dm_cache_policy_get_name(policy);
1710 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1711
1712 if (!policy_name[0] ||
1713 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1714 return -EINVAL;
1715
1716 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
1717 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
1718
1719 hint_size = dm_cache_policy_get_hint_size(policy);
1720 if (!hint_size)
1721 return 0; /* short-circuit hints initialization */
1722 cmd->policy_hint_size = hint_size;
1723
1724 if (cmd->hint_root) {
1725 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1726 if (r)
1727 return r;
1728 }
1729
1730 return dm_array_new(&cmd->hint_info, &cmd->hint_root,
1731 from_cblock(cmd->cache_blocks),
1732 get_hint, policy);
1733 }
1734
1735 int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1736 {
1737 int r;
1738
1739 WRITE_LOCK(cmd);
1740 r = write_hints(cmd, policy);
1741 WRITE_UNLOCK(cmd);
1742
1743 return r;
1744 }
1745
1746 int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
1747 {
1748 int r;
1749
1750 READ_LOCK(cmd);
1751 r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
1752 READ_UNLOCK(cmd);
1753
1754 return r;
1755 }
1756
1757 void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
1758 {
1759 WRITE_LOCK_VOID(cmd);
1760 dm_bm_set_read_only(cmd->bm);
1761 WRITE_UNLOCK(cmd);
1762 }
1763
1764 void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
1765 {
1766 WRITE_LOCK_VOID(cmd);
1767 dm_bm_set_read_write(cmd->bm);
1768 WRITE_UNLOCK(cmd);
1769 }
1770
1771 int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
1772 {
1773 int r;
1774 struct dm_block *sblock;
1775 struct cache_disk_superblock *disk_super;
1776
1777 WRITE_LOCK(cmd);
1778 set_bit(NEEDS_CHECK, &cmd->flags);
1779
1780 r = superblock_lock(cmd, &sblock);
1781 if (r) {
1782 DMERR("couldn't read superblock");
1783 goto out;
1784 }
1785
1786 disk_super = dm_block_data(sblock);
1787 disk_super->flags = cpu_to_le32(cmd->flags);
1788
1789 dm_bm_unlock(sblock);
1790
1791 out:
1792 WRITE_UNLOCK(cmd);
1793 return r;
1794 }
1795
1796 int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result)
1797 {
1798 READ_LOCK(cmd);
1799 *result = !!test_bit(NEEDS_CHECK, &cmd->flags);
1800 READ_UNLOCK(cmd);
1801
1802 return 0;
1803 }
1804
1805 int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
1806 {
1807 int r;
1808
1809 WRITE_LOCK(cmd);
1810 __destroy_persistent_data_objects(cmd);
1811 r = __create_persistent_data_objects(cmd, false);
1812 if (r)
1813 cmd->fail_io = true;
1814 WRITE_UNLOCK(cmd);
1815
1816 return r;
1817 }
Linux with added FPC-III support