1
2
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4
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
23
24
25
26
27#define MIN_CACHE_VERSION 1
28#define MAX_CACHE_VERSION 2
29
30
31
32
33
34#define CACHE_MAX_CONCURRENT_LOCKS 5
35#define SPACE_MAP_ROOT_SIZE 128
36
37enum superblock_flag_bits {
38
39 CLEAN_SHUTDOWN,
40
41 NEEDS_CHECK,
42};
43
44
45
46
47enum mapping_bits {
48
49
50
51
52 M_VALID = 1,
53
54
55
56
57
58 M_DIRTY = 2
59};
60
61struct cache_disk_superblock {
62 __le32 csum;
63 __le32 flags;
64 __le64 blocknr;
65
66 __u8 uuid[16];
67 __le64 magic;
68 __le32 version;
69
70 __u8 policy_name[CACHE_POLICY_NAME_SIZE];
71 __le32 policy_hint_size;
72
73 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
74 __le64 mapping_root;
75 __le64 hint_root;
76
77 __le64 discard_root;
78 __le64 discard_block_size;
79 __le64 discard_nr_blocks;
80
81 __le32 data_block_size;
82 __le32 metadata_block_size;
83 __le32 cache_blocks;
84
85 __le32 compat_flags;
86 __le32 compat_ro_flags;
87 __le32 incompat_flags;
88
89 __le32 read_hits;
90 __le32 read_misses;
91 __le32 write_hits;
92 __le32 write_misses;
93
94 __le32 policy_version[CACHE_POLICY_VERSION_SIZE];
95
96
97
98
99 __le64 dirty_root;
100} __packed;
101
102struct dm_cache_metadata {
103 atomic_t ref_count;
104 struct list_head list;
105
106 unsigned version;
107 struct block_device *bdev;
108 struct dm_block_manager *bm;
109 struct dm_space_map *metadata_sm;
110 struct dm_transaction_manager *tm;
111
112 struct dm_array_info info;
113 struct dm_array_info hint_info;
114 struct dm_disk_bitset discard_info;
115
116 struct rw_semaphore root_lock;
117 unsigned long flags;
118 dm_block_t root;
119 dm_block_t hint_root;
120 dm_block_t discard_root;
121
122 sector_t discard_block_size;
123 dm_dblock_t discard_nr_blocks;
124
125 sector_t data_block_size;
126 dm_cblock_t cache_blocks;
127 bool changed:1;
128 bool clean_when_opened:1;
129
130 char policy_name[CACHE_POLICY_NAME_SIZE];
131 unsigned policy_version[CACHE_POLICY_VERSION_SIZE];
132 size_t policy_hint_size;
133 struct dm_cache_statistics stats;
134
135
136
137
138
139 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
140
141
142
143
144
145
146
147 bool fail_io:1;
148
149
150
151
152 dm_block_t dirty_root;
153 struct dm_disk_bitset dirty_info;
154
155
156
157
158
159 struct dm_array_cursor mapping_cursor;
160 struct dm_array_cursor hint_cursor;
161 struct dm_bitset_cursor dirty_cursor;
162};
163
164
165
166
167
168#define SUPERBLOCK_CSUM_XOR 9031977
169
170static void sb_prepare_for_write(struct dm_block_validator *v,
171 struct dm_block *b,
172 size_t sb_block_size)
173{
174 struct cache_disk_superblock *disk_super = dm_block_data(b);
175
176 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
177 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
178 sb_block_size - sizeof(__le32),
179 SUPERBLOCK_CSUM_XOR));
180}
181
182static int check_metadata_version(struct cache_disk_superblock *disk_super)
183{
184 uint32_t metadata_version = le32_to_cpu(disk_super->version);
185
186 if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) {
187 DMERR("Cache metadata version %u found, but only versions between %u and %u supported.",
188 metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION);
189 return -EINVAL;
190 }
191
192 return 0;
193}
194
195static int sb_check(struct dm_block_validator *v,
196 struct dm_block *b,
197 size_t sb_block_size)
198{
199 struct cache_disk_superblock *disk_super = dm_block_data(b);
200 __le32 csum_le;
201
202 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
203 DMERR("sb_check failed: blocknr %llu: wanted %llu",
204 le64_to_cpu(disk_super->blocknr),
205 (unsigned long long)dm_block_location(b));
206 return -ENOTBLK;
207 }
208
209 if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) {
210 DMERR("sb_check failed: magic %llu: wanted %llu",
211 le64_to_cpu(disk_super->magic),
212 (unsigned long long)CACHE_SUPERBLOCK_MAGIC);
213 return -EILSEQ;
214 }
215
216 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
217 sb_block_size - sizeof(__le32),
218 SUPERBLOCK_CSUM_XOR));
219 if (csum_le != disk_super->csum) {
220 DMERR("sb_check failed: csum %u: wanted %u",
221 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
222 return -EILSEQ;
223 }
224
225 return check_metadata_version(disk_super);
226}
227
228static struct dm_block_validator sb_validator = {
229 .name = "superblock",
230 .prepare_for_write = sb_prepare_for_write,
231 .check = sb_check
232};
233
234
235
236static int superblock_read_lock(struct dm_cache_metadata *cmd,
237 struct dm_block **sblock)
238{
239 return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
240 &sb_validator, sblock);
241}
242
243static int superblock_lock_zero(struct dm_cache_metadata *cmd,
244 struct dm_block **sblock)
245{
246 return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
247 &sb_validator, sblock);
248}
249
250static int superblock_lock(struct dm_cache_metadata *cmd,
251 struct dm_block **sblock)
252{
253 return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
254 &sb_validator, sblock);
255}
256
257
258
259static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
260{
261 int r;
262 unsigned i;
263 struct dm_block *b;
264 __le64 *data_le, zero = cpu_to_le64(0);
265 unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
266
267
268
269
270 r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b);
271 if (r)
272 return r;
273
274 data_le = dm_block_data(b);
275 *result = true;
276 for (i = 0; i < sb_block_size; i++) {
277 if (data_le[i] != zero) {
278 *result = false;
279 break;
280 }
281 }
282
283 dm_bm_unlock(b);
284
285 return 0;
286}
287
288static void __setup_mapping_info(struct dm_cache_metadata *cmd)
289{
290 struct dm_btree_value_type vt;
291
292 vt.context = NULL;
293 vt.size = sizeof(__le64);
294 vt.inc = NULL;
295 vt.dec = NULL;
296 vt.equal = NULL;
297 dm_array_info_init(&cmd->info, cmd->tm, &vt);
298
299 if (cmd->policy_hint_size) {
300 vt.size = sizeof(__le32);
301 dm_array_info_init(&cmd->hint_info, cmd->tm, &vt);
302 }
303}
304
305static int __save_sm_root(struct dm_cache_metadata *cmd)
306{
307 int r;
308 size_t metadata_len;
309
310 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
311 if (r < 0)
312 return r;
313
314 return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
315 metadata_len);
316}
317
318static void __copy_sm_root(struct dm_cache_metadata *cmd,
319 struct cache_disk_superblock *disk_super)
320{
321 memcpy(&disk_super->metadata_space_map_root,
322 &cmd->metadata_space_map_root,
323 sizeof(cmd->metadata_space_map_root));
324}
325
326static bool separate_dirty_bits(struct dm_cache_metadata *cmd)
327{
328 return cmd->version >= 2;
329}
330
331static int __write_initial_superblock(struct dm_cache_metadata *cmd)
332{
333 int r;
334 struct dm_block *sblock;
335 struct cache_disk_superblock *disk_super;
336 sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
337
338
339 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
340 bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
341
342 r = dm_tm_pre_commit(cmd->tm);
343 if (r < 0)
344 return r;
345
346
347
348
349
350 r = __save_sm_root(cmd);
351 if (r)
352 return r;
353
354 r = superblock_lock_zero(cmd, &sblock);
355 if (r)
356 return r;
357
358 disk_super = dm_block_data(sblock);
359 disk_super->flags = 0;
360 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
361 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
362 disk_super->version = cpu_to_le32(cmd->version);
363 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
364 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
365 disk_super->policy_hint_size = cpu_to_le32(0);
366
367 __copy_sm_root(cmd, disk_super);
368
369 disk_super->mapping_root = cpu_to_le64(cmd->root);
370 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
371 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
372 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
373 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
374 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE);
375 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
376 disk_super->cache_blocks = cpu_to_le32(0);
377
378 disk_super->read_hits = cpu_to_le32(0);
379 disk_super->read_misses = cpu_to_le32(0);
380 disk_super->write_hits = cpu_to_le32(0);
381 disk_super->write_misses = cpu_to_le32(0);
382
383 if (separate_dirty_bits(cmd))
384 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
385
386 return dm_tm_commit(cmd->tm, sblock);
387}
388
389static int __format_metadata(struct dm_cache_metadata *cmd)
390{
391 int r;
392
393 r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
394 &cmd->tm, &cmd->metadata_sm);
395 if (r < 0) {
396 DMERR("tm_create_with_sm failed");
397 return r;
398 }
399
400 __setup_mapping_info(cmd);
401
402 r = dm_array_empty(&cmd->info, &cmd->root);
403 if (r < 0)
404 goto bad;
405
406 if (separate_dirty_bits(cmd)) {
407 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info);
408 r = dm_bitset_empty(&cmd->dirty_info, &cmd->dirty_root);
409 if (r < 0)
410 goto bad;
411 }
412
413 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
414 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root);
415 if (r < 0)
416 goto bad;
417
418 cmd->discard_block_size = 0;
419 cmd->discard_nr_blocks = 0;
420
421 r = __write_initial_superblock(cmd);
422 if (r)
423 goto bad;
424
425 cmd->clean_when_opened = true;
426 return 0;
427
428bad:
429 dm_tm_destroy(cmd->tm);
430 dm_sm_destroy(cmd->metadata_sm);
431
432 return r;
433}
434
435static int __check_incompat_features(struct cache_disk_superblock *disk_super,
436 struct dm_cache_metadata *cmd)
437{
438 uint32_t incompat_flags, features;
439
440 incompat_flags = le32_to_cpu(disk_super->incompat_flags);
441 features = incompat_flags & ~DM_CACHE_FEATURE_INCOMPAT_SUPP;
442 if (features) {
443 DMERR("could not access metadata due to unsupported optional features (%lx).",
444 (unsigned long)features);
445 return -EINVAL;
446 }
447
448
449
450
451 if (get_disk_ro(cmd->bdev->bd_disk))
452 return 0;
453
454 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP;
455 if (features) {
456 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
457 (unsigned long)features);
458 return -EINVAL;
459 }
460
461 return 0;
462}
463
464static int __open_metadata(struct dm_cache_metadata *cmd)
465{
466 int r;
467 struct dm_block *sblock;
468 struct cache_disk_superblock *disk_super;
469 unsigned long sb_flags;
470
471 r = superblock_read_lock(cmd, &sblock);
472 if (r < 0) {
473 DMERR("couldn't read lock superblock");
474 return r;
475 }
476
477 disk_super = dm_block_data(sblock);
478
479
480 if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) {
481 DMERR("changing the data block size (from %u to %llu) is not supported",
482 le32_to_cpu(disk_super->data_block_size),
483 (unsigned long long)cmd->data_block_size);
484 r = -EINVAL;
485 goto bad;
486 }
487
488 r = __check_incompat_features(disk_super, cmd);
489 if (r < 0)
490 goto bad;
491
492 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
493 disk_super->metadata_space_map_root,
494 sizeof(disk_super->metadata_space_map_root),
495 &cmd->tm, &cmd->metadata_sm);
496 if (r < 0) {
497 DMERR("tm_open_with_sm failed");
498 goto bad;
499 }
500
501 __setup_mapping_info(cmd);
502 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info);
503 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
504 sb_flags = le32_to_cpu(disk_super->flags);
505 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
506 dm_bm_unlock(sblock);
507
508 return 0;
509
510bad:
511 dm_bm_unlock(sblock);
512 return r;
513}
514
515static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
516 bool format_device)
517{
518 int r;
519 bool unformatted = false;
520
521 r = __superblock_all_zeroes(cmd->bm, &unformatted);
522 if (r)
523 return r;
524
525 if (unformatted)
526 return format_device ? __format_metadata(cmd) : -EPERM;
527
528 return __open_metadata(cmd);
529}
530
531static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
532 bool may_format_device)
533{
534 int r;
535 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
536 CACHE_MAX_CONCURRENT_LOCKS);
537 if (IS_ERR(cmd->bm)) {
538 DMERR("could not create block manager");
539 return PTR_ERR(cmd->bm);
540 }
541
542 r = __open_or_format_metadata(cmd, may_format_device);
543 if (r)
544 dm_block_manager_destroy(cmd->bm);
545
546 return r;
547}
548
549static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd)
550{
551 dm_sm_destroy(cmd->metadata_sm);
552 dm_tm_destroy(cmd->tm);
553 dm_block_manager_destroy(cmd->bm);
554}
555
556typedef unsigned long (*flags_mutator)(unsigned long);
557
558static void update_flags(struct cache_disk_superblock *disk_super,
559 flags_mutator mutator)
560{
561 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
562 disk_super->flags = cpu_to_le32(sb_flags);
563}
564
565static unsigned long set_clean_shutdown(unsigned long flags)
566{
567 set_bit(CLEAN_SHUTDOWN, &flags);
568 return flags;
569}
570
571static unsigned long clear_clean_shutdown(unsigned long flags)
572{
573 clear_bit(CLEAN_SHUTDOWN, &flags);
574 return flags;
575}
576
577static void read_superblock_fields(struct dm_cache_metadata *cmd,
578 struct cache_disk_superblock *disk_super)
579{
580 cmd->version = le32_to_cpu(disk_super->version);
581 cmd->flags = le32_to_cpu(disk_super->flags);
582 cmd->root = le64_to_cpu(disk_super->mapping_root);
583 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
584 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
585 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
586 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
587 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
588 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
589 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
590 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
591 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
592 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
593 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
594
595 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
596 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
597 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
598 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
599
600 if (separate_dirty_bits(cmd))
601 cmd->dirty_root = le64_to_cpu(disk_super->dirty_root);
602
603 cmd->changed = false;
604}
605
606
607
608
609static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
610 flags_mutator mutator)
611{
612 int r;
613 struct cache_disk_superblock *disk_super;
614 struct dm_block *sblock;
615
616 r = superblock_lock(cmd, &sblock);
617 if (r)
618 return r;
619
620 disk_super = dm_block_data(sblock);
621 update_flags(disk_super, mutator);
622 read_superblock_fields(cmd, disk_super);
623 dm_bm_unlock(sblock);
624
625 return dm_bm_flush(cmd->bm);
626}
627
628static int __begin_transaction(struct dm_cache_metadata *cmd)
629{
630 int r;
631 struct cache_disk_superblock *disk_super;
632 struct dm_block *sblock;
633
634
635
636
637
638 r = superblock_read_lock(cmd, &sblock);
639 if (r)
640 return r;
641
642 disk_super = dm_block_data(sblock);
643 read_superblock_fields(cmd, disk_super);
644 dm_bm_unlock(sblock);
645
646 return 0;
647}
648
649static int __commit_transaction(struct dm_cache_metadata *cmd,
650 flags_mutator mutator)
651{
652 int r;
653 struct cache_disk_superblock *disk_super;
654 struct dm_block *sblock;
655
656
657
658
659 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
660
661 if (separate_dirty_bits(cmd)) {
662 r = dm_bitset_flush(&cmd->dirty_info, cmd->dirty_root,
663 &cmd->dirty_root);
664 if (r)
665 return r;
666 }
667
668 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
669 &cmd->discard_root);
670 if (r)
671 return r;
672
673 r = dm_tm_pre_commit(cmd->tm);
674 if (r < 0)
675 return r;
676
677 r = __save_sm_root(cmd);
678 if (r)
679 return r;
680
681 r = superblock_lock(cmd, &sblock);
682 if (r)
683 return r;
684
685 disk_super = dm_block_data(sblock);
686
687 disk_super->flags = cpu_to_le32(cmd->flags);
688 if (mutator)
689 update_flags(disk_super, mutator);
690
691 disk_super->mapping_root = cpu_to_le64(cmd->root);
692 if (separate_dirty_bits(cmd))
693 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
694 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
695 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
696 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
697 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
698 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
699 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
700 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
701 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
702 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
703 disk_super->policy_hint_size = cpu_to_le32(cmd->policy_hint_size);
704
705 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
706 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
707 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
708 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
709 __copy_sm_root(cmd, disk_super);
710
711 return dm_tm_commit(cmd->tm, sblock);
712}
713
714
715
716
717
718
719
720
721#define FLAGS_MASK ((1 << 16) - 1)
722
723static __le64 pack_value(dm_oblock_t block, unsigned flags)
724{
725 uint64_t value = from_oblock(block);
726 value <<= 16;
727 value = value | (flags & FLAGS_MASK);
728 return cpu_to_le64(value);
729}
730
731static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
732{
733 uint64_t value = le64_to_cpu(value_le);
734 uint64_t b = value >> 16;
735 *block = to_oblock(b);
736 *flags = value & FLAGS_MASK;
737}
738
739
740
741static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
742 sector_t data_block_size,
743 bool may_format_device,
744 size_t policy_hint_size,
745 unsigned metadata_version)
746{
747 int r;
748 struct dm_cache_metadata *cmd;
749
750 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
751 if (!cmd) {
752 DMERR("could not allocate metadata struct");
753 return ERR_PTR(-ENOMEM);
754 }
755
756 cmd->version = metadata_version;
757 atomic_set(&cmd->ref_count, 1);
758 init_rwsem(&cmd->root_lock);
759 cmd->bdev = bdev;
760 cmd->data_block_size = data_block_size;
761 cmd->cache_blocks = 0;
762 cmd->policy_hint_size = policy_hint_size;
763 cmd->changed = true;
764 cmd->fail_io = false;
765
766 r = __create_persistent_data_objects(cmd, may_format_device);
767 if (r) {
768 kfree(cmd);
769 return ERR_PTR(r);
770 }
771
772 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
773 if (r < 0) {
774 dm_cache_metadata_close(cmd);
775 return ERR_PTR(r);
776 }
777
778 return cmd;
779}
780
781
782
783
784
785
786static DEFINE_MUTEX(table_lock);
787static LIST_HEAD(table);
788
789static struct dm_cache_metadata *lookup(struct block_device *bdev)
790{
791 struct dm_cache_metadata *cmd;
792
793 list_for_each_entry(cmd, &table, list)
794 if (cmd->bdev == bdev) {
795 atomic_inc(&cmd->ref_count);
796 return cmd;
797 }
798
799 return NULL;
800}
801
802static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev,
803 sector_t data_block_size,
804 bool may_format_device,
805 size_t policy_hint_size,
806 unsigned metadata_version)
807{
808 struct dm_cache_metadata *cmd, *cmd2;
809
810 mutex_lock(&table_lock);
811 cmd = lookup(bdev);
812 mutex_unlock(&table_lock);
813
814 if (cmd)
815 return cmd;
816
817 cmd = metadata_open(bdev, data_block_size, may_format_device,
818 policy_hint_size, metadata_version);
819 if (!IS_ERR(cmd)) {
820 mutex_lock(&table_lock);
821 cmd2 = lookup(bdev);
822 if (cmd2) {
823 mutex_unlock(&table_lock);
824 __destroy_persistent_data_objects(cmd);
825 kfree(cmd);
826 return cmd2;
827 }
828 list_add(&cmd->list, &table);
829 mutex_unlock(&table_lock);
830 }
831
832 return cmd;
833}
834
835static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size)
836{
837 if (cmd->data_block_size != data_block_size) {
838 DMERR("data_block_size (%llu) different from that in metadata (%llu)",
839 (unsigned long long) data_block_size,
840 (unsigned long long) cmd->data_block_size);
841 return false;
842 }
843
844 return true;
845}
846
847struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
848 sector_t data_block_size,
849 bool may_format_device,
850 size_t policy_hint_size,
851 unsigned metadata_version)
852{
853 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, may_format_device,
854 policy_hint_size, metadata_version);
855
856 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) {
857 dm_cache_metadata_close(cmd);
858 return ERR_PTR(-EINVAL);
859 }
860
861 return cmd;
862}
863
864void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
865{
866 if (atomic_dec_and_test(&cmd->ref_count)) {
867 mutex_lock(&table_lock);
868 list_del(&cmd->list);
869 mutex_unlock(&table_lock);
870
871 if (!cmd->fail_io)
872 __destroy_persistent_data_objects(cmd);
873 kfree(cmd);
874 }
875}
876
877
878
879
880static int block_clean_combined_dirty(struct dm_cache_metadata *cmd, dm_cblock_t b,
881 bool *result)
882{
883 int r;
884 __le64 value;
885 dm_oblock_t ob;
886 unsigned flags;
887
888 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
889 if (r)
890 return r;
891
892 unpack_value(value, &ob, &flags);
893 *result = !((flags & M_VALID) && (flags & M_DIRTY));
894
895 return 0;
896}
897
898static int blocks_are_clean_combined_dirty(struct dm_cache_metadata *cmd,
899 dm_cblock_t begin, dm_cblock_t end,
900 bool *result)
901{
902 int r;
903 *result = true;
904
905 while (begin != end) {
906 r = block_clean_combined_dirty(cmd, begin, result);
907 if (r) {
908 DMERR("block_clean_combined_dirty failed");
909 return r;
910 }
911
912 if (!*result) {
913 DMERR("cache block %llu is dirty",
914 (unsigned long long) from_cblock(begin));
915 return 0;
916 }
917
918 begin = to_cblock(from_cblock(begin) + 1);
919 }
920
921 return 0;
922}
923
924static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd,
925 dm_cblock_t begin, dm_cblock_t end,
926 bool *result)
927{
928 int r;
929 bool dirty_flag;
930 *result = true;
931
932 if (from_cblock(cmd->cache_blocks) == 0)
933
934 return 0;
935
936 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
937 from_cblock(cmd->cache_blocks), &cmd->dirty_cursor);
938 if (r) {
939 DMERR("%s: dm_bitset_cursor_begin for dirty failed", __func__);
940 return r;
941 }
942
943 r = dm_bitset_cursor_skip(&cmd->dirty_cursor, from_cblock(begin));
944 if (r) {
945 DMERR("%s: dm_bitset_cursor_skip for dirty failed", __func__);
946 dm_bitset_cursor_end(&cmd->dirty_cursor);
947 return r;
948 }
949
950 while (begin != end) {
951
952
953
954
955 dirty_flag = dm_bitset_cursor_get_value(&cmd->dirty_cursor);
956 if (dirty_flag) {
957 DMERR("%s: cache block %llu is dirty", __func__,
958 (unsigned long long) from_cblock(begin));
959 dm_bitset_cursor_end(&cmd->dirty_cursor);
960 *result = false;
961 return 0;
962 }
963
964 begin = to_cblock(from_cblock(begin) + 1);
965 if (begin == end)
966 break;
967
968 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
969 if (r) {
970 DMERR("%s: dm_bitset_cursor_next for dirty failed", __func__);
971 dm_bitset_cursor_end(&cmd->dirty_cursor);
972 return r;
973 }
974 }
975
976 dm_bitset_cursor_end(&cmd->dirty_cursor);
977
978 return 0;
979}
980
981static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
982 dm_cblock_t begin, dm_cblock_t end,
983 bool *result)
984{
985 if (separate_dirty_bits(cmd))
986 return blocks_are_clean_separate_dirty(cmd, begin, end, result);
987 else
988 return blocks_are_clean_combined_dirty(cmd, begin, end, result);
989}
990
991static bool cmd_write_lock(struct dm_cache_metadata *cmd)
992{
993 down_write(&cmd->root_lock);
994 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
995 up_write(&cmd->root_lock);
996 return false;
997 }
998 return true;
999}
1000
1001#define WRITE_LOCK(cmd) \
1002 do { \
1003 if (!cmd_write_lock((cmd))) \
1004 return -EINVAL; \
1005 } while(0)
1006
1007#define WRITE_LOCK_VOID(cmd) \
1008 do { \
1009 if (!cmd_write_lock((cmd))) \
1010 return; \
1011 } while(0)
1012
1013#define WRITE_UNLOCK(cmd) \
1014 up_write(&(cmd)->root_lock)
1015
1016static bool cmd_read_lock(struct dm_cache_metadata *cmd)
1017{
1018 down_read(&cmd->root_lock);
1019 if (cmd->fail_io) {
1020 up_read(&cmd->root_lock);
1021 return false;
1022 }
1023 return true;
1024}
1025
1026#define READ_LOCK(cmd) \
1027 do { \
1028 if (!cmd_read_lock((cmd))) \
1029 return -EINVAL; \
1030 } while(0)
1031
1032#define READ_LOCK_VOID(cmd) \
1033 do { \
1034 if (!cmd_read_lock((cmd))) \
1035 return; \
1036 } while(0)
1037
1038#define READ_UNLOCK(cmd) \
1039 up_read(&(cmd)->root_lock)
1040
1041int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
1042{
1043 int r;
1044 bool clean;
1045 __le64 null_mapping = pack_value(0, 0);
1046
1047 WRITE_LOCK(cmd);
1048 __dm_bless_for_disk(&null_mapping);
1049
1050 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
1051 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
1052 if (r) {
1053 __dm_unbless_for_disk(&null_mapping);
1054 goto out;
1055 }
1056
1057 if (!clean) {
1058 DMERR("unable to shrink cache due to dirty blocks");
1059 r = -EINVAL;
1060 __dm_unbless_for_disk(&null_mapping);
1061 goto out;
1062 }
1063 }
1064
1065 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
1066 from_cblock(new_cache_size),
1067 &null_mapping, &cmd->root);
1068 if (r)
1069 goto out;
1070
1071 if (separate_dirty_bits(cmd)) {
1072 r = dm_bitset_resize(&cmd->dirty_info, cmd->dirty_root,
1073 from_cblock(cmd->cache_blocks), from_cblock(new_cache_size),
1074 false, &cmd->dirty_root);
1075 if (r)
1076 goto out;
1077 }
1078
1079 cmd->cache_blocks = new_cache_size;
1080 cmd->changed = true;
1081
1082out:
1083 WRITE_UNLOCK(cmd);
1084
1085 return r;
1086}
1087
1088int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
1089 sector_t discard_block_size,
1090 dm_dblock_t new_nr_entries)
1091{
1092 int r;
1093
1094 WRITE_LOCK(cmd);
1095 r = dm_bitset_resize(&cmd->discard_info,
1096 cmd->discard_root,
1097 from_dblock(cmd->discard_nr_blocks),
1098 from_dblock(new_nr_entries),
1099 false, &cmd->discard_root);
1100 if (!r) {
1101 cmd->discard_block_size = discard_block_size;
1102 cmd->discard_nr_blocks = new_nr_entries;
1103 }
1104
1105 cmd->changed = true;
1106 WRITE_UNLOCK(cmd);
1107
1108 return r;
1109}
1110
1111static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1112{
1113 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
1114 from_dblock(b), &cmd->discard_root);
1115}
1116
1117static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1118{
1119 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
1120 from_dblock(b), &cmd->discard_root);
1121}
1122
1123static int __discard(struct dm_cache_metadata *cmd,
1124 dm_dblock_t dblock, bool discard)
1125{
1126 int r;
1127
1128 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
1129 if (r)
1130 return r;
1131
1132 cmd->changed = true;
1133 return 0;
1134}
1135
1136int dm_cache_set_discard(struct dm_cache_metadata *cmd,
1137 dm_dblock_t dblock, bool discard)
1138{
1139 int r;
1140
1141 WRITE_LOCK(cmd);
1142 r = __discard(cmd, dblock, discard);
1143 WRITE_UNLOCK(cmd);
1144
1145 return r;
1146}
1147
1148static int __load_discards(struct dm_cache_metadata *cmd,
1149 load_discard_fn fn, void *context)
1150{
1151 int r = 0;
1152 uint32_t b;
1153 struct dm_bitset_cursor c;
1154
1155 if (from_dblock(cmd->discard_nr_blocks) == 0)
1156
1157 return 0;
1158
1159 if (cmd->clean_when_opened) {
1160 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, &cmd->discard_root);
1161 if (r)
1162 return r;
1163
1164 r = dm_bitset_cursor_begin(&cmd->discard_info, cmd->discard_root,
1165 from_dblock(cmd->discard_nr_blocks), &c);
1166 if (r)
1167 return r;
1168
1169 for (b = 0; ; b++) {
1170 r = fn(context, cmd->discard_block_size, to_dblock(b),
1171 dm_bitset_cursor_get_value(&c));
1172 if (r)
1173 break;
1174
1175 if (b >= (from_dblock(cmd->discard_nr_blocks) - 1))
1176 break;
1177
1178 r = dm_bitset_cursor_next(&c);
1179 if (r)
1180 break;
1181 }
1182
1183 dm_bitset_cursor_end(&c);
1184
1185 } else {
1186 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
1187 r = fn(context, cmd->discard_block_size, to_dblock(b), false);
1188 if (r)
1189 return r;
1190 }
1191 }
1192
1193 return r;
1194}
1195
1196int dm_cache_load_discards(struct dm_cache_metadata *cmd,
1197 load_discard_fn fn, void *context)
1198{
1199 int r;
1200
1201 READ_LOCK(cmd);
1202 r = __load_discards(cmd, fn, context);
1203 READ_UNLOCK(cmd);
1204
1205 return r;
1206}
1207
1208int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result)
1209{
1210 READ_LOCK(cmd);
1211 *result = cmd->cache_blocks;
1212 READ_UNLOCK(cmd);
1213
1214 return 0;
1215}
1216
1217static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1218{
1219 int r;
1220 __le64 value = pack_value(0, 0);
1221
1222 __dm_bless_for_disk(&value);
1223 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1224 &value, &cmd->root);
1225 if (r)
1226 return r;
1227
1228 cmd->changed = true;
1229 return 0;
1230}
1231
1232int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1233{
1234 int r;
1235
1236 WRITE_LOCK(cmd);
1237 r = __remove(cmd, cblock);
1238 WRITE_UNLOCK(cmd);
1239
1240 return r;
1241}
1242
1243static int __insert(struct dm_cache_metadata *cmd,
1244 dm_cblock_t cblock, dm_oblock_t oblock)
1245{
1246 int r;
1247 __le64 value = pack_value(oblock, M_VALID);
1248 __dm_bless_for_disk(&value);
1249
1250 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1251 &value, &cmd->root);
1252 if (r)
1253 return r;
1254
1255 cmd->changed = true;
1256 return 0;
1257}
1258
1259int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
1260 dm_cblock_t cblock, dm_oblock_t oblock)
1261{
1262 int r;
1263
1264 WRITE_LOCK(cmd);
1265 r = __insert(cmd, cblock, oblock);
1266 WRITE_UNLOCK(cmd);
1267
1268 return r;
1269}
1270
1271struct thunk {
1272 load_mapping_fn fn;
1273 void *context;
1274
1275 struct dm_cache_metadata *cmd;
1276 bool respect_dirty_flags;
1277 bool hints_valid;
1278};
1279
1280static bool policy_unchanged(struct dm_cache_metadata *cmd,
1281 struct dm_cache_policy *policy)
1282{
1283 const char *policy_name = dm_cache_policy_get_name(policy);
1284 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1285 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
1286
1287
1288
1289
1290 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
1291 return false;
1292
1293
1294
1295
1296 if (cmd->policy_version[0] != policy_version[0])
1297 return false;
1298
1299
1300
1301
1302 if (cmd->policy_hint_size != policy_hint_size)
1303 return false;
1304
1305 return true;
1306}
1307
1308static bool hints_array_initialized(struct dm_cache_metadata *cmd)
1309{
1310 return cmd->hint_root && cmd->policy_hint_size;
1311}
1312
1313static bool hints_array_available(struct dm_cache_metadata *cmd,
1314 struct dm_cache_policy *policy)
1315{
1316 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
1317 hints_array_initialized(cmd);
1318}
1319
1320static int __load_mapping_v1(struct dm_cache_metadata *cmd,
1321 uint64_t cb, bool hints_valid,
1322 struct dm_array_cursor *mapping_cursor,
1323 struct dm_array_cursor *hint_cursor,
1324 load_mapping_fn fn, void *context)
1325{
1326 int r = 0;
1327
1328 __le64 mapping;
1329 __le32 hint = 0;
1330
1331 __le64 *mapping_value_le;
1332 __le32 *hint_value_le;
1333
1334 dm_oblock_t oblock;
1335 unsigned flags;
1336 bool dirty = true;
1337
1338 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1339 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1340 unpack_value(mapping, &oblock, &flags);
1341
1342 if (flags & M_VALID) {
1343 if (hints_valid) {
1344 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1345 memcpy(&hint, hint_value_le, sizeof(hint));
1346 }
1347 if (cmd->clean_when_opened)
1348 dirty = flags & M_DIRTY;
1349
1350 r = fn(context, oblock, to_cblock(cb), dirty,
1351 le32_to_cpu(hint), hints_valid);
1352 if (r) {
1353 DMERR("policy couldn't load cache block %llu",
1354 (unsigned long long) from_cblock(to_cblock(cb)));
1355 }
1356 }
1357
1358 return r;
1359}
1360
1361static int __load_mapping_v2(struct dm_cache_metadata *cmd,
1362 uint64_t cb, bool hints_valid,
1363 struct dm_array_cursor *mapping_cursor,
1364 struct dm_array_cursor *hint_cursor,
1365 struct dm_bitset_cursor *dirty_cursor,
1366 load_mapping_fn fn, void *context)
1367{
1368 int r = 0;
1369
1370 __le64 mapping;
1371 __le32 hint = 0;
1372
1373 __le64 *mapping_value_le;
1374 __le32 *hint_value_le;
1375
1376 dm_oblock_t oblock;
1377 unsigned flags;
1378 bool dirty = true;
1379
1380 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1381 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1382 unpack_value(mapping, &oblock, &flags);
1383
1384 if (flags & M_VALID) {
1385 if (hints_valid) {
1386 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1387 memcpy(&hint, hint_value_le, sizeof(hint));
1388 }
1389 if (cmd->clean_when_opened)
1390 dirty = dm_bitset_cursor_get_value(dirty_cursor);
1391
1392 r = fn(context, oblock, to_cblock(cb), dirty,
1393 le32_to_cpu(hint), hints_valid);
1394 if (r) {
1395 DMERR("policy couldn't load cache block %llu",
1396 (unsigned long long) from_cblock(to_cblock(cb)));
1397 }
1398 }
1399
1400 return r;
1401}
1402
1403static int __load_mappings(struct dm_cache_metadata *cmd,
1404 struct dm_cache_policy *policy,
1405 load_mapping_fn fn, void *context)
1406{
1407 int r;
1408 uint64_t cb;
1409
1410 bool hints_valid = hints_array_available(cmd, policy);
1411
1412 if (from_cblock(cmd->cache_blocks) == 0)
1413
1414 return 0;
1415
1416 r = dm_array_cursor_begin(&cmd->info, cmd->root, &cmd->mapping_cursor);
1417 if (r)
1418 return r;
1419
1420 if (hints_valid) {
1421 r = dm_array_cursor_begin(&cmd->hint_info, cmd->hint_root, &cmd->hint_cursor);
1422 if (r) {
1423 dm_array_cursor_end(&cmd->mapping_cursor);
1424 return r;
1425 }
1426 }
1427
1428 if (separate_dirty_bits(cmd)) {
1429 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
1430 from_cblock(cmd->cache_blocks),
1431 &cmd->dirty_cursor);
1432 if (r) {
1433 dm_array_cursor_end(&cmd->hint_cursor);
1434 dm_array_cursor_end(&cmd->mapping_cursor);
1435 return r;
1436 }
1437 }
1438
1439 for (cb = 0; ; cb++) {
1440 if (separate_dirty_bits(cmd))
1441 r = __load_mapping_v2(cmd, cb, hints_valid,
1442 &cmd->mapping_cursor,
1443 &cmd->hint_cursor,
1444 &cmd->dirty_cursor,
1445 fn, context);
1446 else
1447 r = __load_mapping_v1(cmd, cb, hints_valid,
1448 &cmd->mapping_cursor, &cmd->hint_cursor,
1449 fn, context);
1450 if (r)
1451 goto out;
1452
1453
1454
1455
1456 if (cb >= (from_cblock(cmd->cache_blocks) - 1))
1457 break;
1458
1459 r = dm_array_cursor_next(&cmd->mapping_cursor);
1460 if (r) {
1461 DMERR("dm_array_cursor_next for mapping failed");
1462 goto out;
1463 }
1464
1465 if (hints_valid) {
1466 r = dm_array_cursor_next(&cmd->hint_cursor);
1467 if (r) {
1468 dm_array_cursor_end(&cmd->hint_cursor);
1469 hints_valid = false;
1470 }
1471 }
1472
1473 if (separate_dirty_bits(cmd)) {
1474 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
1475 if (r) {
1476 DMERR("dm_bitset_cursor_next for dirty failed");
1477 goto out;
1478 }
1479 }
1480 }
1481out:
1482 dm_array_cursor_end(&cmd->mapping_cursor);
1483 if (hints_valid)
1484 dm_array_cursor_end(&cmd->hint_cursor);
1485
1486 if (separate_dirty_bits(cmd))
1487 dm_bitset_cursor_end(&cmd->dirty_cursor);
1488
1489 return r;
1490}
1491
1492int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
1493 struct dm_cache_policy *policy,
1494 load_mapping_fn fn, void *context)
1495{
1496 int r;
1497
1498 READ_LOCK(cmd);
1499 r = __load_mappings(cmd, policy, fn, context);
1500 READ_UNLOCK(cmd);
1501
1502 return r;
1503}
1504
1505static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
1506{
1507 int r = 0;
1508 __le64 value;
1509 dm_oblock_t oblock;
1510 unsigned flags;
1511
1512 memcpy(&value, leaf, sizeof(value));
1513 unpack_value(value, &oblock, &flags);
1514
1515 return r;
1516}
1517
1518static int __dump_mappings(struct dm_cache_metadata *cmd)
1519{
1520 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
1521}
1522
1523void dm_cache_dump(struct dm_cache_metadata *cmd)
1524{
1525 READ_LOCK_VOID(cmd);
1526 __dump_mappings(cmd);
1527 READ_UNLOCK(cmd);
1528}
1529
1530int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1531{
1532 int r;
1533
1534 READ_LOCK(cmd);
1535 r = cmd->changed;
1536 READ_UNLOCK(cmd);
1537
1538 return r;
1539}
1540
1541static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1542{
1543 int r;
1544 unsigned flags;
1545 dm_oblock_t oblock;
1546 __le64 value;
1547
1548 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1549 if (r)
1550 return r;
1551
1552 unpack_value(value, &oblock, &flags);
1553
1554 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1555
1556 return 0;
1557
1558 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
1559 __dm_bless_for_disk(&value);
1560
1561 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1562 &value, &cmd->root);
1563 if (r)
1564 return r;
1565
1566 cmd->changed = true;
1567 return 0;
1568
1569}
1570
1571static int __set_dirty_bits_v1(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1572{
1573 int r;
1574 unsigned i;
1575 for (i = 0; i < nr_bits; i++) {
1576 r = __dirty(cmd, to_cblock(i), test_bit(i, bits));
1577 if (r)
1578 return r;
1579 }
1580
1581 return 0;
1582}
1583
1584static int is_dirty_callback(uint32_t index, bool *value, void *context)
1585{
1586 unsigned long *bits = context;
1587 *value = test_bit(index, bits);
1588 return 0;
1589}
1590
1591static int __set_dirty_bits_v2(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1592{
1593 int r = 0;
1594
1595
1596 if (nr_bits != from_cblock(cmd->cache_blocks)) {
1597 DMERR("dirty bitset is wrong size");
1598 return -EINVAL;
1599 }
1600
1601 r = dm_bitset_del(&cmd->dirty_info, cmd->dirty_root);
1602 if (r)
1603 return r;
1604
1605 cmd->changed = true;
1606 return dm_bitset_new(&cmd->dirty_info, &cmd->dirty_root, nr_bits, is_dirty_callback, bits);
1607}
1608
1609int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd,
1610 unsigned nr_bits,
1611 unsigned long *bits)
1612{
1613 int r;
1614
1615 WRITE_LOCK(cmd);
1616 if (separate_dirty_bits(cmd))
1617 r = __set_dirty_bits_v2(cmd, nr_bits, bits);
1618 else
1619 r = __set_dirty_bits_v1(cmd, nr_bits, bits);
1620 WRITE_UNLOCK(cmd);
1621
1622 return r;
1623}
1624
1625void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1626 struct dm_cache_statistics *stats)
1627{
1628 READ_LOCK_VOID(cmd);
1629 *stats = cmd->stats;
1630 READ_UNLOCK(cmd);
1631}
1632
1633void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1634 struct dm_cache_statistics *stats)
1635{
1636 WRITE_LOCK_VOID(cmd);
1637 cmd->stats = *stats;
1638 WRITE_UNLOCK(cmd);
1639}
1640
1641int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1642{
1643 int r = -EINVAL;
1644 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1645 clear_clean_shutdown);
1646
1647 WRITE_LOCK(cmd);
1648 if (cmd->fail_io)
1649 goto out;
1650
1651 r = __commit_transaction(cmd, mutator);
1652 if (r)
1653 goto out;
1654
1655 r = __begin_transaction(cmd);
1656out:
1657 WRITE_UNLOCK(cmd);
1658 return r;
1659}
1660
1661int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1662 dm_block_t *result)
1663{
1664 int r = -EINVAL;
1665
1666 READ_LOCK(cmd);
1667 if (!cmd->fail_io)
1668 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1669 READ_UNLOCK(cmd);
1670
1671 return r;
1672}
1673
1674int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1675 dm_block_t *result)
1676{
1677 int r = -EINVAL;
1678
1679 READ_LOCK(cmd);
1680 if (!cmd->fail_io)
1681 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1682 READ_UNLOCK(cmd);
1683
1684 return r;
1685}
1686
1687
1688
1689static int get_hint(uint32_t index, void *value_le, void *context)
1690{
1691 uint32_t value;
1692 struct dm_cache_policy *policy = context;
1693
1694 value = policy_get_hint(policy, to_cblock(index));
1695 *((__le32 *) value_le) = cpu_to_le32(value);
1696
1697 return 0;
1698}
1699
1700
1701
1702
1703
1704static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1705{
1706 int r;
1707 size_t hint_size;
1708 const char *policy_name = dm_cache_policy_get_name(policy);
1709 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1710
1711 if (!policy_name[0] ||
1712 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1713 return -EINVAL;
1714
1715 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
1716 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
1717
1718 hint_size = dm_cache_policy_get_hint_size(policy);
1719 if (!hint_size)
1720 return 0;
1721 cmd->policy_hint_size = hint_size;
1722
1723 if (cmd->hint_root) {
1724 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1725 if (r)
1726 return r;
1727 }
1728
1729 return dm_array_new(&cmd->hint_info, &cmd->hint_root,
1730 from_cblock(cmd->cache_blocks),
1731 get_hint, policy);
1732}
1733
1734int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1735{
1736 int r;
1737
1738 WRITE_LOCK(cmd);
1739 r = write_hints(cmd, policy);
1740 WRITE_UNLOCK(cmd);
1741
1742 return r;
1743}
1744
1745int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
1746{
1747 int r;
1748
1749 READ_LOCK(cmd);
1750 r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
1751 READ_UNLOCK(cmd);
1752
1753 return r;
1754}
1755
1756void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
1757{
1758 WRITE_LOCK_VOID(cmd);
1759 dm_bm_set_read_only(cmd->bm);
1760 WRITE_UNLOCK(cmd);
1761}
1762
1763void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
1764{
1765 WRITE_LOCK_VOID(cmd);
1766 dm_bm_set_read_write(cmd->bm);
1767 WRITE_UNLOCK(cmd);
1768}
1769
1770int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
1771{
1772 int r;
1773 struct dm_block *sblock;
1774 struct cache_disk_superblock *disk_super;
1775
1776 WRITE_LOCK(cmd);
1777 set_bit(NEEDS_CHECK, &cmd->flags);
1778
1779 r = superblock_lock(cmd, &sblock);
1780 if (r) {
1781 DMERR("couldn't read superblock");
1782 goto out;
1783 }
1784
1785 disk_super = dm_block_data(sblock);
1786 disk_super->flags = cpu_to_le32(cmd->flags);
1787
1788 dm_bm_unlock(sblock);
1789
1790out:
1791 WRITE_UNLOCK(cmd);
1792 return r;
1793}
1794
1795int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result)
1796{
1797 READ_LOCK(cmd);
1798 *result = !!test_bit(NEEDS_CHECK, &cmd->flags);
1799 READ_UNLOCK(cmd);
1800
1801 return 0;
1802}
1803
1804int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
1805{
1806 int r;
1807
1808 WRITE_LOCK(cmd);
1809 __destroy_persistent_data_objects(cmd);
1810 r = __create_persistent_data_objects(cmd, false);
1811 if (r)
1812 cmd->fail_io = true;
1813 WRITE_UNLOCK(cmd);
1814
1815 return r;
1816}
1817
