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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
38enum 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 */
48enum 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
62struct 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
103struct 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
171static 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
183static 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
196static 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
229static 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
237static 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
244static 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
251static 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
260static 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
289static 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
306static 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
319static 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
327static bool separate_dirty_bits(struct dm_cache_metadata *cmd)
328{
329 return cmd->version >= 2;
330}
331
332static 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 = bdev_nr_sectors(cmd->bdev);
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
390static 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
429bad:
430 dm_tm_destroy(cmd->tm);
431 dm_sm_destroy(cmd->metadata_sm);
432
433 return r;
434}
435
436static 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 (bdev_read_only(cmd->bdev))
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
465static 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
511bad:
512 dm_bm_unlock(sblock);
513 return r;
514}
515
516static 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
532static 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 r = PTR_ERR(cmd->bm);
541 cmd->bm = NULL;
542 return r;
543 }
544
545 r = __open_or_format_metadata(cmd, may_format_device);
546 if (r) {
547 dm_block_manager_destroy(cmd->bm);
548 cmd->bm = NULL;
549 }
550
551 return r;
552}
553
554static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd,
555 bool destroy_bm)
556{
557 dm_sm_destroy(cmd->metadata_sm);
558 dm_tm_destroy(cmd->tm);
559 if (destroy_bm)
560 dm_block_manager_destroy(cmd->bm);
561}
562
563typedef unsigned long (*flags_mutator)(unsigned long);
564
565static void update_flags(struct cache_disk_superblock *disk_super,
566 flags_mutator mutator)
567{
568 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
569 disk_super->flags = cpu_to_le32(sb_flags);
570}
571
572static unsigned long set_clean_shutdown(unsigned long flags)
573{
574 set_bit(CLEAN_SHUTDOWN, &flags);
575 return flags;
576}
577
578static unsigned long clear_clean_shutdown(unsigned long flags)
579{
580 clear_bit(CLEAN_SHUTDOWN, &flags);
581 return flags;
582}
583
584static void read_superblock_fields(struct dm_cache_metadata *cmd,
585 struct cache_disk_superblock *disk_super)
586{
587 cmd->version = le32_to_cpu(disk_super->version);
588 cmd->flags = le32_to_cpu(disk_super->flags);
589 cmd->root = le64_to_cpu(disk_super->mapping_root);
590 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
591 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
592 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
593 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
594 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
595 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
596 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
597 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
598 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
599 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
600 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
601
602 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
603 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
604 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
605 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
606
607 if (separate_dirty_bits(cmd))
608 cmd->dirty_root = le64_to_cpu(disk_super->dirty_root);
609
610 cmd->changed = false;
611}
612
613/*
614 * The mutator updates the superblock flags.
615 */
616static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
617 flags_mutator mutator)
618{
619 int r;
620 struct cache_disk_superblock *disk_super;
621 struct dm_block *sblock;
622
623 r = superblock_lock(cmd, &sblock);
624 if (r)
625 return r;
626
627 disk_super = dm_block_data(sblock);
628 update_flags(disk_super, mutator);
629 read_superblock_fields(cmd, disk_super);
630 dm_bm_unlock(sblock);
631
632 return dm_bm_flush(cmd->bm);
633}
634
635static int __begin_transaction(struct dm_cache_metadata *cmd)
636{
637 int r;
638 struct cache_disk_superblock *disk_super;
639 struct dm_block *sblock;
640
641 /*
642 * We re-read the superblock every time. Shouldn't need to do this
643 * really.
644 */
645 r = superblock_read_lock(cmd, &sblock);
646 if (r)
647 return r;
648
649 disk_super = dm_block_data(sblock);
650 read_superblock_fields(cmd, disk_super);
651 dm_bm_unlock(sblock);
652
653 return 0;
654}
655
656static int __commit_transaction(struct dm_cache_metadata *cmd,
657 flags_mutator mutator)
658{
659 int r;
660 struct cache_disk_superblock *disk_super;
661 struct dm_block *sblock;
662
663 /*
664 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
665 */
666 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
667
668 if (separate_dirty_bits(cmd)) {
669 r = dm_bitset_flush(&cmd->dirty_info, cmd->dirty_root,
670 &cmd->dirty_root);
671 if (r)
672 return r;
673 }
674
675 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
676 &cmd->discard_root);
677 if (r)
678 return r;
679
680 r = dm_tm_pre_commit(cmd->tm);
681 if (r < 0)
682 return r;
683
684 r = __save_sm_root(cmd);
685 if (r)
686 return r;
687
688 r = superblock_lock(cmd, &sblock);
689 if (r)
690 return r;
691
692 disk_super = dm_block_data(sblock);
693
694 disk_super->flags = cpu_to_le32(cmd->flags);
695 if (mutator)
696 update_flags(disk_super, mutator);
697
698 disk_super->mapping_root = cpu_to_le64(cmd->root);
699 if (separate_dirty_bits(cmd))
700 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
701 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
702 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
703 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
704 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
705 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
706 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
707 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
708 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
709 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
710 disk_super->policy_hint_size = cpu_to_le32(cmd->policy_hint_size);
711
712 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
713 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
714 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
715 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
716 __copy_sm_root(cmd, disk_super);
717
718 return dm_tm_commit(cmd->tm, sblock);
719}
720
721/*----------------------------------------------------------------*/
722
723/*
724 * The mappings are held in a dm-array that has 64-bit values stored in
725 * little-endian format. The index is the cblock, the high 48bits of the
726 * value are the oblock and the low 16 bit the flags.
727 */
728#define FLAGS_MASK ((1 << 16) - 1)
729
730static __le64 pack_value(dm_oblock_t block, unsigned flags)
731{
732 uint64_t value = from_oblock(block);
733 value <<= 16;
734 value = value | (flags & FLAGS_MASK);
735 return cpu_to_le64(value);
736}
737
738static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
739{
740 uint64_t value = le64_to_cpu(value_le);
741 uint64_t b = value >> 16;
742 *block = to_oblock(b);
743 *flags = value & FLAGS_MASK;
744}
745
746/*----------------------------------------------------------------*/
747
748static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
749 sector_t data_block_size,
750 bool may_format_device,
751 size_t policy_hint_size,
752 unsigned metadata_version)
753{
754 int r;
755 struct dm_cache_metadata *cmd;
756
757 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
758 if (!cmd) {
759 DMERR("could not allocate metadata struct");
760 return ERR_PTR(-ENOMEM);
761 }
762
763 cmd->version = metadata_version;
764 refcount_set(&cmd->ref_count, 1);
765 init_rwsem(&cmd->root_lock);
766 cmd->bdev = bdev;
767 cmd->data_block_size = data_block_size;
768 cmd->cache_blocks = 0;
769 cmd->policy_hint_size = policy_hint_size;
770 cmd->changed = true;
771 cmd->fail_io = false;
772
773 r = __create_persistent_data_objects(cmd, may_format_device);
774 if (r) {
775 kfree(cmd);
776 return ERR_PTR(r);
777 }
778
779 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
780 if (r < 0) {
781 dm_cache_metadata_close(cmd);
782 return ERR_PTR(r);
783 }
784
785 return cmd;
786}
787
788/*
789 * We keep a little list of ref counted metadata objects to prevent two
790 * different target instances creating separate bufio instances. This is
791 * an issue if a table is reloaded before the suspend.
792 */
793static DEFINE_MUTEX(table_lock);
794static LIST_HEAD(table);
795
796static struct dm_cache_metadata *lookup(struct block_device *bdev)
797{
798 struct dm_cache_metadata *cmd;
799
800 list_for_each_entry(cmd, &table, list)
801 if (cmd->bdev == bdev) {
802 refcount_inc(&cmd->ref_count);
803 return cmd;
804 }
805
806 return NULL;
807}
808
809static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev,
810 sector_t data_block_size,
811 bool may_format_device,
812 size_t policy_hint_size,
813 unsigned metadata_version)
814{
815 struct dm_cache_metadata *cmd, *cmd2;
816
817 mutex_lock(&table_lock);
818 cmd = lookup(bdev);
819 mutex_unlock(&table_lock);
820
821 if (cmd)
822 return cmd;
823
824 cmd = metadata_open(bdev, data_block_size, may_format_device,
825 policy_hint_size, metadata_version);
826 if (!IS_ERR(cmd)) {
827 mutex_lock(&table_lock);
828 cmd2 = lookup(bdev);
829 if (cmd2) {
830 mutex_unlock(&table_lock);
831 __destroy_persistent_data_objects(cmd, true);
832 kfree(cmd);
833 return cmd2;
834 }
835 list_add(&cmd->list, &table);
836 mutex_unlock(&table_lock);
837 }
838
839 return cmd;
840}
841
842static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size)
843{
844 if (cmd->data_block_size != data_block_size) {
845 DMERR("data_block_size (%llu) different from that in metadata (%llu)",
846 (unsigned long long) data_block_size,
847 (unsigned long long) cmd->data_block_size);
848 return false;
849 }
850
851 return true;
852}
853
854struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
855 sector_t data_block_size,
856 bool may_format_device,
857 size_t policy_hint_size,
858 unsigned metadata_version)
859{
860 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, may_format_device,
861 policy_hint_size, metadata_version);
862
863 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) {
864 dm_cache_metadata_close(cmd);
865 return ERR_PTR(-EINVAL);
866 }
867
868 return cmd;
869}
870
871void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
872{
873 if (refcount_dec_and_test(&cmd->ref_count)) {
874 mutex_lock(&table_lock);
875 list_del(&cmd->list);
876 mutex_unlock(&table_lock);
877
878 if (!cmd->fail_io)
879 __destroy_persistent_data_objects(cmd, true);
880 kfree(cmd);
881 }
882}
883
884/*
885 * Checks that the given cache block is either unmapped or clean.
886 */
887static int block_clean_combined_dirty(struct dm_cache_metadata *cmd, dm_cblock_t b,
888 bool *result)
889{
890 int r;
891 __le64 value;
892 dm_oblock_t ob;
893 unsigned flags;
894
895 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
896 if (r)
897 return r;
898
899 unpack_value(value, &ob, &flags);
900 *result = !((flags & M_VALID) && (flags & M_DIRTY));
901
902 return 0;
903}
904
905static int blocks_are_clean_combined_dirty(struct dm_cache_metadata *cmd,
906 dm_cblock_t begin, dm_cblock_t end,
907 bool *result)
908{
909 int r;
910 *result = true;
911
912 while (begin != end) {
913 r = block_clean_combined_dirty(cmd, begin, result);
914 if (r) {
915 DMERR("block_clean_combined_dirty failed");
916 return r;
917 }
918
919 if (!*result) {
920 DMERR("cache block %llu is dirty",
921 (unsigned long long) from_cblock(begin));
922 return 0;
923 }
924
925 begin = to_cblock(from_cblock(begin) + 1);
926 }
927
928 return 0;
929}
930
931static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd,
932 dm_cblock_t begin, dm_cblock_t end,
933 bool *result)
934{
935 int r;
936 bool dirty_flag;
937 *result = true;
938
939 if (from_cblock(cmd->cache_blocks) == 0)
940 /* Nothing to do */
941 return 0;
942
943 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
944 from_cblock(cmd->cache_blocks), &cmd->dirty_cursor);
945 if (r) {
946 DMERR("%s: dm_bitset_cursor_begin for dirty failed", __func__);
947 return r;
948 }
949
950 r = dm_bitset_cursor_skip(&cmd->dirty_cursor, from_cblock(begin));
951 if (r) {
952 DMERR("%s: dm_bitset_cursor_skip for dirty failed", __func__);
953 dm_bitset_cursor_end(&cmd->dirty_cursor);
954 return r;
955 }
956
957 while (begin != end) {
958 /*
959 * We assume that unmapped blocks have their dirty bit
960 * cleared.
961 */
962 dirty_flag = dm_bitset_cursor_get_value(&cmd->dirty_cursor);
963 if (dirty_flag) {
964 DMERR("%s: cache block %llu is dirty", __func__,
965 (unsigned long long) from_cblock(begin));
966 dm_bitset_cursor_end(&cmd->dirty_cursor);
967 *result = false;
968 return 0;
969 }
970
971 begin = to_cblock(from_cblock(begin) + 1);
972 if (begin == end)
973 break;
974
975 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
976 if (r) {
977 DMERR("%s: dm_bitset_cursor_next for dirty failed", __func__);
978 dm_bitset_cursor_end(&cmd->dirty_cursor);
979 return r;
980 }
981 }
982
983 dm_bitset_cursor_end(&cmd->dirty_cursor);
984
985 return 0;
986}
987
988static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
989 dm_cblock_t begin, dm_cblock_t end,
990 bool *result)
991{
992 if (separate_dirty_bits(cmd))
993 return blocks_are_clean_separate_dirty(cmd, begin, end, result);
994 else
995 return blocks_are_clean_combined_dirty(cmd, begin, end, result);
996}
997
998static bool cmd_write_lock(struct dm_cache_metadata *cmd)
999{
1000 down_write(&cmd->root_lock);
1001 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
1002 up_write(&cmd->root_lock);
1003 return false;
1004 }
1005 return true;
1006}
1007
1008#define WRITE_LOCK(cmd) \
1009 do { \
1010 if (!cmd_write_lock((cmd))) \
1011 return -EINVAL; \
1012 } while(0)
1013
1014#define WRITE_LOCK_VOID(cmd) \
1015 do { \
1016 if (!cmd_write_lock((cmd))) \
1017 return; \
1018 } while(0)
1019
1020#define WRITE_UNLOCK(cmd) \
1021 up_write(&(cmd)->root_lock)
1022
1023static bool cmd_read_lock(struct dm_cache_metadata *cmd)
1024{
1025 down_read(&cmd->root_lock);
1026 if (cmd->fail_io) {
1027 up_read(&cmd->root_lock);
1028 return false;
1029 }
1030 return true;
1031}
1032
1033#define READ_LOCK(cmd) \
1034 do { \
1035 if (!cmd_read_lock((cmd))) \
1036 return -EINVAL; \
1037 } while(0)
1038
1039#define READ_LOCK_VOID(cmd) \
1040 do { \
1041 if (!cmd_read_lock((cmd))) \
1042 return; \
1043 } while(0)
1044
1045#define READ_UNLOCK(cmd) \
1046 up_read(&(cmd)->root_lock)
1047
1048int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
1049{
1050 int r;
1051 bool clean;
1052 __le64 null_mapping = pack_value(0, 0);
1053
1054 WRITE_LOCK(cmd);
1055 __dm_bless_for_disk(&null_mapping);
1056
1057 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
1058 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
1059 if (r) {
1060 __dm_unbless_for_disk(&null_mapping);
1061 goto out;
1062 }
1063
1064 if (!clean) {
1065 DMERR("unable to shrink cache due to dirty blocks");
1066 r = -EINVAL;
1067 __dm_unbless_for_disk(&null_mapping);
1068 goto out;
1069 }
1070 }
1071
1072 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
1073 from_cblock(new_cache_size),
1074 &null_mapping, &cmd->root);
1075 if (r)
1076 goto out;
1077
1078 if (separate_dirty_bits(cmd)) {
1079 r = dm_bitset_resize(&cmd->dirty_info, cmd->dirty_root,
1080 from_cblock(cmd->cache_blocks), from_cblock(new_cache_size),
1081 false, &cmd->dirty_root);
1082 if (r)
1083 goto out;
1084 }
1085
1086 cmd->cache_blocks = new_cache_size;
1087 cmd->changed = true;
1088
1089out:
1090 WRITE_UNLOCK(cmd);
1091
1092 return r;
1093}
1094
1095int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
1096 sector_t discard_block_size,
1097 dm_dblock_t new_nr_entries)
1098{
1099 int r;
1100
1101 WRITE_LOCK(cmd);
1102 r = dm_bitset_resize(&cmd->discard_info,
1103 cmd->discard_root,
1104 from_dblock(cmd->discard_nr_blocks),
1105 from_dblock(new_nr_entries),
1106 false, &cmd->discard_root);
1107 if (!r) {
1108 cmd->discard_block_size = discard_block_size;
1109 cmd->discard_nr_blocks = new_nr_entries;
1110 }
1111
1112 cmd->changed = true;
1113 WRITE_UNLOCK(cmd);
1114
1115 return r;
1116}
1117
1118static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1119{
1120 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
1121 from_dblock(b), &cmd->discard_root);
1122}
1123
1124static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1125{
1126 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
1127 from_dblock(b), &cmd->discard_root);
1128}
1129
1130static int __discard(struct dm_cache_metadata *cmd,
1131 dm_dblock_t dblock, bool discard)
1132{
1133 int r;
1134
1135 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
1136 if (r)
1137 return r;
1138
1139 cmd->changed = true;
1140 return 0;
1141}
1142
1143int dm_cache_set_discard(struct dm_cache_metadata *cmd,
1144 dm_dblock_t dblock, bool discard)
1145{
1146 int r;
1147
1148 WRITE_LOCK(cmd);
1149 r = __discard(cmd, dblock, discard);
1150 WRITE_UNLOCK(cmd);
1151
1152 return r;
1153}
1154
1155static int __load_discards(struct dm_cache_metadata *cmd,
1156 load_discard_fn fn, void *context)
1157{
1158 int r = 0;
1159 uint32_t b;
1160 struct dm_bitset_cursor c;
1161
1162 if (from_dblock(cmd->discard_nr_blocks) == 0)
1163 /* nothing to do */
1164 return 0;
1165
1166 if (cmd->clean_when_opened) {
1167 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, &cmd->discard_root);
1168 if (r)
1169 return r;
1170
1171 r = dm_bitset_cursor_begin(&cmd->discard_info, cmd->discard_root,
1172 from_dblock(cmd->discard_nr_blocks), &c);
1173 if (r)
1174 return r;
1175
1176 for (b = 0; ; b++) {
1177 r = fn(context, cmd->discard_block_size, to_dblock(b),
1178 dm_bitset_cursor_get_value(&c));
1179 if (r)
1180 break;
1181
1182 if (b >= (from_dblock(cmd->discard_nr_blocks) - 1))
1183 break;
1184
1185 r = dm_bitset_cursor_next(&c);
1186 if (r)
1187 break;
1188 }
1189
1190 dm_bitset_cursor_end(&c);
1191
1192 } else {
1193 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
1194 r = fn(context, cmd->discard_block_size, to_dblock(b), false);
1195 if (r)
1196 return r;
1197 }
1198 }
1199
1200 return r;
1201}
1202
1203int dm_cache_load_discards(struct dm_cache_metadata *cmd,
1204 load_discard_fn fn, void *context)
1205{
1206 int r;
1207
1208 READ_LOCK(cmd);
1209 r = __load_discards(cmd, fn, context);
1210 READ_UNLOCK(cmd);
1211
1212 return r;
1213}
1214
1215int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result)
1216{
1217 READ_LOCK(cmd);
1218 *result = cmd->cache_blocks;
1219 READ_UNLOCK(cmd);
1220
1221 return 0;
1222}
1223
1224static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1225{
1226 int r;
1227 __le64 value = pack_value(0, 0);
1228
1229 __dm_bless_for_disk(&value);
1230 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1231 &value, &cmd->root);
1232 if (r)
1233 return r;
1234
1235 cmd->changed = true;
1236 return 0;
1237}
1238
1239int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1240{
1241 int r;
1242
1243 WRITE_LOCK(cmd);
1244 r = __remove(cmd, cblock);
1245 WRITE_UNLOCK(cmd);
1246
1247 return r;
1248}
1249
1250static int __insert(struct dm_cache_metadata *cmd,
1251 dm_cblock_t cblock, dm_oblock_t oblock)
1252{
1253 int r;
1254 __le64 value = pack_value(oblock, M_VALID);
1255 __dm_bless_for_disk(&value);
1256
1257 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1258 &value, &cmd->root);
1259 if (r)
1260 return r;
1261
1262 cmd->changed = true;
1263 return 0;
1264}
1265
1266int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
1267 dm_cblock_t cblock, dm_oblock_t oblock)
1268{
1269 int r;
1270
1271 WRITE_LOCK(cmd);
1272 r = __insert(cmd, cblock, oblock);
1273 WRITE_UNLOCK(cmd);
1274
1275 return r;
1276}
1277
1278struct thunk {
1279 load_mapping_fn fn;
1280 void *context;
1281
1282 struct dm_cache_metadata *cmd;
1283 bool respect_dirty_flags;
1284 bool hints_valid;
1285};
1286
1287static bool policy_unchanged(struct dm_cache_metadata *cmd,
1288 struct dm_cache_policy *policy)
1289{
1290 const char *policy_name = dm_cache_policy_get_name(policy);
1291 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1292 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
1293
1294 /*
1295 * Ensure policy names match.
1296 */
1297 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
1298 return false;
1299
1300 /*
1301 * Ensure policy major versions match.
1302 */
1303 if (cmd->policy_version[0] != policy_version[0])
1304 return false;
1305
1306 /*
1307 * Ensure policy hint sizes match.
1308 */
1309 if (cmd->policy_hint_size != policy_hint_size)
1310 return false;
1311
1312 return true;
1313}
1314
1315static bool hints_array_initialized(struct dm_cache_metadata *cmd)
1316{
1317 return cmd->hint_root && cmd->policy_hint_size;
1318}
1319
1320static bool hints_array_available(struct dm_cache_metadata *cmd,
1321 struct dm_cache_policy *policy)
1322{
1323 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
1324 hints_array_initialized(cmd);
1325}
1326
1327static int __load_mapping_v1(struct dm_cache_metadata *cmd,
1328 uint64_t cb, bool hints_valid,
1329 struct dm_array_cursor *mapping_cursor,
1330 struct dm_array_cursor *hint_cursor,
1331 load_mapping_fn fn, void *context)
1332{
1333 int r = 0;
1334
1335 __le64 mapping;
1336 __le32 hint = 0;
1337
1338 __le64 *mapping_value_le;
1339 __le32 *hint_value_le;
1340
1341 dm_oblock_t oblock;
1342 unsigned flags;
1343 bool dirty = true;
1344
1345 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1346 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1347 unpack_value(mapping, &oblock, &flags);
1348
1349 if (flags & M_VALID) {
1350 if (hints_valid) {
1351 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1352 memcpy(&hint, hint_value_le, sizeof(hint));
1353 }
1354 if (cmd->clean_when_opened)
1355 dirty = flags & M_DIRTY;
1356
1357 r = fn(context, oblock, to_cblock(cb), dirty,
1358 le32_to_cpu(hint), hints_valid);
1359 if (r) {
1360 DMERR("policy couldn't load cache block %llu",
1361 (unsigned long long) from_cblock(to_cblock(cb)));
1362 }
1363 }
1364
1365 return r;
1366}
1367
1368static int __load_mapping_v2(struct dm_cache_metadata *cmd,
1369 uint64_t cb, bool hints_valid,
1370 struct dm_array_cursor *mapping_cursor,
1371 struct dm_array_cursor *hint_cursor,
1372 struct dm_bitset_cursor *dirty_cursor,
1373 load_mapping_fn fn, void *context)
1374{
1375 int r = 0;
1376
1377 __le64 mapping;
1378 __le32 hint = 0;
1379
1380 __le64 *mapping_value_le;
1381 __le32 *hint_value_le;
1382
1383 dm_oblock_t oblock;
1384 unsigned flags;
1385 bool dirty = true;
1386
1387 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1388 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1389 unpack_value(mapping, &oblock, &flags);
1390
1391 if (flags & M_VALID) {
1392 if (hints_valid) {
1393 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1394 memcpy(&hint, hint_value_le, sizeof(hint));
1395 }
1396 if (cmd->clean_when_opened)
1397 dirty = dm_bitset_cursor_get_value(dirty_cursor);
1398
1399 r = fn(context, oblock, to_cblock(cb), dirty,
1400 le32_to_cpu(hint), hints_valid);
1401 if (r) {
1402 DMERR("policy couldn't load cache block %llu",
1403 (unsigned long long) from_cblock(to_cblock(cb)));
1404 }
1405 }
1406
1407 return r;
1408}
1409
1410static int __load_mappings(struct dm_cache_metadata *cmd,
1411 struct dm_cache_policy *policy,
1412 load_mapping_fn fn, void *context)
1413{
1414 int r;
1415 uint64_t cb;
1416
1417 bool hints_valid = hints_array_available(cmd, policy);
1418
1419 if (from_cblock(cmd->cache_blocks) == 0)
1420 /* Nothing to do */
1421 return 0;
1422
1423 r = dm_array_cursor_begin(&cmd->info, cmd->root, &cmd->mapping_cursor);
1424 if (r)
1425 return r;
1426
1427 if (hints_valid) {
1428 r = dm_array_cursor_begin(&cmd->hint_info, cmd->hint_root, &cmd->hint_cursor);
1429 if (r) {
1430 dm_array_cursor_end(&cmd->mapping_cursor);
1431 return r;
1432 }
1433 }
1434
1435 if (separate_dirty_bits(cmd)) {
1436 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
1437 from_cblock(cmd->cache_blocks),
1438 &cmd->dirty_cursor);
1439 if (r) {
1440 dm_array_cursor_end(&cmd->hint_cursor);
1441 dm_array_cursor_end(&cmd->mapping_cursor);
1442 return r;
1443 }
1444 }
1445
1446 for (cb = 0; ; cb++) {
1447 if (separate_dirty_bits(cmd))
1448 r = __load_mapping_v2(cmd, cb, hints_valid,
1449 &cmd->mapping_cursor,
1450 &cmd->hint_cursor,
1451 &cmd->dirty_cursor,
1452 fn, context);
1453 else
1454 r = __load_mapping_v1(cmd, cb, hints_valid,
1455 &cmd->mapping_cursor, &cmd->hint_cursor,
1456 fn, context);
1457 if (r)
1458 goto out;
1459
1460 /*
1461 * We need to break out before we move the cursors.
1462 */
1463 if (cb >= (from_cblock(cmd->cache_blocks) - 1))
1464 break;
1465
1466 r = dm_array_cursor_next(&cmd->mapping_cursor);
1467 if (r) {
1468 DMERR("dm_array_cursor_next for mapping failed");
1469 goto out;
1470 }
1471
1472 if (hints_valid) {
1473 r = dm_array_cursor_next(&cmd->hint_cursor);
1474 if (r) {
1475 dm_array_cursor_end(&cmd->hint_cursor);
1476 hints_valid = false;
1477 }
1478 }
1479
1480 if (separate_dirty_bits(cmd)) {
1481 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
1482 if (r) {
1483 DMERR("dm_bitset_cursor_next for dirty failed");
1484 goto out;
1485 }
1486 }
1487 }
1488out:
1489 dm_array_cursor_end(&cmd->mapping_cursor);
1490 if (hints_valid)
1491 dm_array_cursor_end(&cmd->hint_cursor);
1492
1493 if (separate_dirty_bits(cmd))
1494 dm_bitset_cursor_end(&cmd->dirty_cursor);
1495
1496 return r;
1497}
1498
1499int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
1500 struct dm_cache_policy *policy,
1501 load_mapping_fn fn, void *context)
1502{
1503 int r;
1504
1505 READ_LOCK(cmd);
1506 r = __load_mappings(cmd, policy, fn, context);
1507 READ_UNLOCK(cmd);
1508
1509 return r;
1510}
1511
1512static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
1513{
1514 __le64 value;
1515 dm_oblock_t oblock;
1516 unsigned flags;
1517
1518 memcpy(&value, leaf, sizeof(value));
1519 unpack_value(value, &oblock, &flags);
1520
1521 return 0;
1522}
1523
1524static int __dump_mappings(struct dm_cache_metadata *cmd)
1525{
1526 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
1527}
1528
1529void dm_cache_dump(struct dm_cache_metadata *cmd)
1530{
1531 READ_LOCK_VOID(cmd);
1532 __dump_mappings(cmd);
1533 READ_UNLOCK(cmd);
1534}
1535
1536int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1537{
1538 int r;
1539
1540 READ_LOCK(cmd);
1541 r = cmd->changed;
1542 READ_UNLOCK(cmd);
1543
1544 return r;
1545}
1546
1547static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1548{
1549 int r;
1550 unsigned flags;
1551 dm_oblock_t oblock;
1552 __le64 value;
1553
1554 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1555 if (r)
1556 return r;
1557
1558 unpack_value(value, &oblock, &flags);
1559
1560 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1561 /* nothing to be done */
1562 return 0;
1563
1564 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
1565 __dm_bless_for_disk(&value);
1566
1567 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1568 &value, &cmd->root);
1569 if (r)
1570 return r;
1571
1572 cmd->changed = true;
1573 return 0;
1574
1575}
1576
1577static int __set_dirty_bits_v1(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1578{
1579 int r;
1580 unsigned i;
1581 for (i = 0; i < nr_bits; i++) {
1582 r = __dirty(cmd, to_cblock(i), test_bit(i, bits));
1583 if (r)
1584 return r;
1585 }
1586
1587 return 0;
1588}
1589
1590static int is_dirty_callback(uint32_t index, bool *value, void *context)
1591{
1592 unsigned long *bits = context;
1593 *value = test_bit(index, bits);
1594 return 0;
1595}
1596
1597static int __set_dirty_bits_v2(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1598{
1599 int r = 0;
1600
1601 /* nr_bits is really just a sanity check */
1602 if (nr_bits != from_cblock(cmd->cache_blocks)) {
1603 DMERR("dirty bitset is wrong size");
1604 return -EINVAL;
1605 }
1606
1607 r = dm_bitset_del(&cmd->dirty_info, cmd->dirty_root);
1608 if (r)
1609 return r;
1610
1611 cmd->changed = true;
1612 return dm_bitset_new(&cmd->dirty_info, &cmd->dirty_root, nr_bits, is_dirty_callback, bits);
1613}
1614
1615int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd,
1616 unsigned nr_bits,
1617 unsigned long *bits)
1618{
1619 int r;
1620
1621 WRITE_LOCK(cmd);
1622 if (separate_dirty_bits(cmd))
1623 r = __set_dirty_bits_v2(cmd, nr_bits, bits);
1624 else
1625 r = __set_dirty_bits_v1(cmd, nr_bits, bits);
1626 WRITE_UNLOCK(cmd);
1627
1628 return r;
1629}
1630
1631void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1632 struct dm_cache_statistics *stats)
1633{
1634 READ_LOCK_VOID(cmd);
1635 *stats = cmd->stats;
1636 READ_UNLOCK(cmd);
1637}
1638
1639void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1640 struct dm_cache_statistics *stats)
1641{
1642 WRITE_LOCK_VOID(cmd);
1643 cmd->stats = *stats;
1644 WRITE_UNLOCK(cmd);
1645}
1646
1647int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1648{
1649 int r = -EINVAL;
1650 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1651 clear_clean_shutdown);
1652
1653 WRITE_LOCK(cmd);
1654 if (cmd->fail_io)
1655 goto out;
1656
1657 r = __commit_transaction(cmd, mutator);
1658 if (r)
1659 goto out;
1660
1661 r = __begin_transaction(cmd);
1662out:
1663 WRITE_UNLOCK(cmd);
1664 return r;
1665}
1666
1667int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1668 dm_block_t *result)
1669{
1670 int r = -EINVAL;
1671
1672 READ_LOCK(cmd);
1673 if (!cmd->fail_io)
1674 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1675 READ_UNLOCK(cmd);
1676
1677 return r;
1678}
1679
1680int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1681 dm_block_t *result)
1682{
1683 int r = -EINVAL;
1684
1685 READ_LOCK(cmd);
1686 if (!cmd->fail_io)
1687 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1688 READ_UNLOCK(cmd);
1689
1690 return r;
1691}
1692
1693/*----------------------------------------------------------------*/
1694
1695static int get_hint(uint32_t index, void *value_le, void *context)
1696{
1697 uint32_t value;
1698 struct dm_cache_policy *policy = context;
1699
1700 value = policy_get_hint(policy, to_cblock(index));
1701 *((__le32 *) value_le) = cpu_to_le32(value);
1702
1703 return 0;
1704}
1705
1706/*
1707 * It's quicker to always delete the hint array, and recreate with
1708 * dm_array_new().
1709 */
1710static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1711{
1712 int r;
1713 size_t hint_size;
1714 const char *policy_name = dm_cache_policy_get_name(policy);
1715 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1716
1717 if (!policy_name[0] ||
1718 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1719 return -EINVAL;
1720
1721 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
1722 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
1723
1724 hint_size = dm_cache_policy_get_hint_size(policy);
1725 if (!hint_size)
1726 return 0; /* short-circuit hints initialization */
1727 cmd->policy_hint_size = hint_size;
1728
1729 if (cmd->hint_root) {
1730 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1731 if (r)
1732 return r;
1733 }
1734
1735 return dm_array_new(&cmd->hint_info, &cmd->hint_root,
1736 from_cblock(cmd->cache_blocks),
1737 get_hint, policy);
1738}
1739
1740int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1741{
1742 int r;
1743
1744 WRITE_LOCK(cmd);
1745 r = write_hints(cmd, policy);
1746 WRITE_UNLOCK(cmd);
1747
1748 return r;
1749}
1750
1751int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
1752{
1753 int r;
1754
1755 READ_LOCK(cmd);
1756 r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
1757 READ_UNLOCK(cmd);
1758
1759 return r;
1760}
1761
1762void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
1763{
1764 WRITE_LOCK_VOID(cmd);
1765 dm_bm_set_read_only(cmd->bm);
1766 WRITE_UNLOCK(cmd);
1767}
1768
1769void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
1770{
1771 WRITE_LOCK_VOID(cmd);
1772 dm_bm_set_read_write(cmd->bm);
1773 WRITE_UNLOCK(cmd);
1774}
1775
1776int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
1777{
1778 int r;
1779 struct dm_block *sblock;
1780 struct cache_disk_superblock *disk_super;
1781
1782 WRITE_LOCK(cmd);
1783 set_bit(NEEDS_CHECK, &cmd->flags);
1784
1785 r = superblock_lock(cmd, &sblock);
1786 if (r) {
1787 DMERR("couldn't read superblock");
1788 goto out;
1789 }
1790
1791 disk_super = dm_block_data(sblock);
1792 disk_super->flags = cpu_to_le32(cmd->flags);
1793
1794 dm_bm_unlock(sblock);
1795
1796out:
1797 WRITE_UNLOCK(cmd);
1798 return r;
1799}
1800
1801int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result)
1802{
1803 READ_LOCK(cmd);
1804 *result = !!test_bit(NEEDS_CHECK, &cmd->flags);
1805 READ_UNLOCK(cmd);
1806
1807 return 0;
1808}
1809
1810int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
1811{
1812 int r = -EINVAL;
1813 struct dm_block_manager *old_bm = NULL, *new_bm = NULL;
1814
1815 /* fail_io is double-checked with cmd->root_lock held below */
1816 if (unlikely(cmd->fail_io))
1817 return r;
1818
1819 /*
1820 * Replacement block manager (new_bm) is created and old_bm destroyed outside of
1821 * cmd root_lock to avoid ABBA deadlock that would result (due to life-cycle of
1822 * shrinker associated with the block manager's bufio client vs cmd root_lock).
1823 * - must take shrinker_rwsem without holding cmd->root_lock
1824 */
1825 new_bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
1826 CACHE_MAX_CONCURRENT_LOCKS);
1827
1828 WRITE_LOCK(cmd);
1829 if (cmd->fail_io) {
1830 WRITE_UNLOCK(cmd);
1831 goto out;
1832 }
1833
1834 __destroy_persistent_data_objects(cmd, false);
1835 old_bm = cmd->bm;
1836 if (IS_ERR(new_bm)) {
1837 DMERR("could not create block manager during abort");
1838 cmd->bm = NULL;
1839 r = PTR_ERR(new_bm);
1840 goto out_unlock;
1841 }
1842
1843 cmd->bm = new_bm;
1844 r = __open_or_format_metadata(cmd, false);
1845 if (r) {
1846 cmd->bm = NULL;
1847 goto out_unlock;
1848 }
1849 new_bm = NULL;
1850out_unlock:
1851 if (r)
1852 cmd->fail_io = true;
1853 WRITE_UNLOCK(cmd);
1854 dm_block_manager_destroy(old_bm);
1855out:
1856 if (new_bm && !IS_ERR(new_bm))
1857 dm_block_manager_destroy(new_bm);
1858
1859 return r;
1860}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2012 Red Hat, Inc.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm-cache-metadata.h"
9
10#include "persistent-data/dm-array.h"
11#include "persistent-data/dm-bitset.h"
12#include "persistent-data/dm-space-map.h"
13#include "persistent-data/dm-space-map-disk.h"
14#include "persistent-data/dm-transaction-manager.h"
15
16#include <linux/device-mapper.h>
17#include <linux/refcount.h>
18
19/*----------------------------------------------------------------*/
20
21#define DM_MSG_PREFIX "cache metadata"
22
23#define CACHE_SUPERBLOCK_MAGIC 06142003
24#define CACHE_SUPERBLOCK_LOCATION 0
25
26/*
27 * defines a range of metadata versions that this module can handle.
28 */
29#define MIN_CACHE_VERSION 1
30#define MAX_CACHE_VERSION 2
31
32/*
33 * 3 for btree insert +
34 * 2 for btree lookup used within space map
35 */
36#define CACHE_MAX_CONCURRENT_LOCKS 5
37#define SPACE_MAP_ROOT_SIZE 128
38
39enum superblock_flag_bits {
40 /* for spotting crashes that would invalidate the dirty bitset */
41 CLEAN_SHUTDOWN,
42 /* metadata must be checked using the tools */
43 NEEDS_CHECK,
44};
45
46/*
47 * Each mapping from cache block -> origin block carries a set of flags.
48 */
49enum mapping_bits {
50 /*
51 * A valid mapping. Because we're using an array we clear this
52 * flag for an non existant mapping.
53 */
54 M_VALID = 1,
55
56 /*
57 * The data on the cache is different from that on the origin.
58 * This flag is only used by metadata format 1.
59 */
60 M_DIRTY = 2
61};
62
63struct cache_disk_superblock {
64 __le32 csum;
65 __le32 flags;
66 __le64 blocknr;
67
68 __u8 uuid[16];
69 __le64 magic;
70 __le32 version;
71
72 __u8 policy_name[CACHE_POLICY_NAME_SIZE];
73 __le32 policy_hint_size;
74
75 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
76 __le64 mapping_root;
77 __le64 hint_root;
78
79 __le64 discard_root;
80 __le64 discard_block_size;
81 __le64 discard_nr_blocks;
82
83 __le32 data_block_size;
84 __le32 metadata_block_size;
85 __le32 cache_blocks;
86
87 __le32 compat_flags;
88 __le32 compat_ro_flags;
89 __le32 incompat_flags;
90
91 __le32 read_hits;
92 __le32 read_misses;
93 __le32 write_hits;
94 __le32 write_misses;
95
96 __le32 policy_version[CACHE_POLICY_VERSION_SIZE];
97
98 /*
99 * Metadata format 2 fields.
100 */
101 __le64 dirty_root;
102} __packed;
103
104struct dm_cache_metadata {
105 refcount_t ref_count;
106 struct list_head list;
107
108 unsigned int version;
109 struct block_device *bdev;
110 struct dm_block_manager *bm;
111 struct dm_space_map *metadata_sm;
112 struct dm_transaction_manager *tm;
113
114 struct dm_array_info info;
115 struct dm_array_info hint_info;
116 struct dm_disk_bitset discard_info;
117
118 struct rw_semaphore root_lock;
119 unsigned long flags;
120 dm_block_t root;
121 dm_block_t hint_root;
122 dm_block_t discard_root;
123
124 sector_t discard_block_size;
125 dm_dblock_t discard_nr_blocks;
126
127 sector_t data_block_size;
128 dm_cblock_t cache_blocks;
129 bool changed:1;
130 bool clean_when_opened:1;
131
132 char policy_name[CACHE_POLICY_NAME_SIZE];
133 unsigned int policy_version[CACHE_POLICY_VERSION_SIZE];
134 size_t policy_hint_size;
135 struct dm_cache_statistics stats;
136
137 /*
138 * Reading the space map root can fail, so we read it into this
139 * buffer before the superblock is locked and updated.
140 */
141 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
142
143 /*
144 * Set if a transaction has to be aborted but the attempt to roll
145 * back to the previous (good) transaction failed. The only
146 * metadata operation permissible in this state is the closing of
147 * the device.
148 */
149 bool fail_io:1;
150
151 /*
152 * Metadata format 2 fields.
153 */
154 dm_block_t dirty_root;
155 struct dm_disk_bitset dirty_info;
156
157 /*
158 * These structures are used when loading metadata. They're too
159 * big to put on the stack.
160 */
161 struct dm_array_cursor mapping_cursor;
162 struct dm_array_cursor hint_cursor;
163 struct dm_bitset_cursor dirty_cursor;
164};
165
166/*
167 *-----------------------------------------------------------------
168 * superblock validator
169 *-----------------------------------------------------------------
170 */
171#define SUPERBLOCK_CSUM_XOR 9031977
172
173static void sb_prepare_for_write(const struct dm_block_validator *v,
174 struct dm_block *b,
175 size_t sb_block_size)
176{
177 struct cache_disk_superblock *disk_super = dm_block_data(b);
178
179 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
180 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
181 sb_block_size - sizeof(__le32),
182 SUPERBLOCK_CSUM_XOR));
183}
184
185static int check_metadata_version(struct cache_disk_superblock *disk_super)
186{
187 uint32_t metadata_version = le32_to_cpu(disk_super->version);
188
189 if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) {
190 DMERR("Cache metadata version %u found, but only versions between %u and %u supported.",
191 metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION);
192 return -EINVAL;
193 }
194
195 return 0;
196}
197
198static int sb_check(const struct dm_block_validator *v,
199 struct dm_block *b,
200 size_t sb_block_size)
201{
202 struct cache_disk_superblock *disk_super = dm_block_data(b);
203 __le32 csum_le;
204
205 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
206 DMERR("%s failed: blocknr %llu: wanted %llu",
207 __func__, le64_to_cpu(disk_super->blocknr),
208 (unsigned long long)dm_block_location(b));
209 return -ENOTBLK;
210 }
211
212 if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) {
213 DMERR("%s failed: magic %llu: wanted %llu",
214 __func__, le64_to_cpu(disk_super->magic),
215 (unsigned long long)CACHE_SUPERBLOCK_MAGIC);
216 return -EILSEQ;
217 }
218
219 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
220 sb_block_size - sizeof(__le32),
221 SUPERBLOCK_CSUM_XOR));
222 if (csum_le != disk_super->csum) {
223 DMERR("%s failed: csum %u: wanted %u",
224 __func__, le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
225 return -EILSEQ;
226 }
227
228 return check_metadata_version(disk_super);
229}
230
231static const struct dm_block_validator sb_validator = {
232 .name = "superblock",
233 .prepare_for_write = sb_prepare_for_write,
234 .check = sb_check
235};
236
237/*----------------------------------------------------------------*/
238
239static int superblock_read_lock(struct dm_cache_metadata *cmd,
240 struct dm_block **sblock)
241{
242 return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
243 &sb_validator, sblock);
244}
245
246static int superblock_lock_zero(struct dm_cache_metadata *cmd,
247 struct dm_block **sblock)
248{
249 return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
250 &sb_validator, sblock);
251}
252
253static int superblock_lock(struct dm_cache_metadata *cmd,
254 struct dm_block **sblock)
255{
256 return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
257 &sb_validator, sblock);
258}
259
260/*----------------------------------------------------------------*/
261
262static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
263{
264 int r;
265 unsigned int i;
266 struct dm_block *b;
267 __le64 *data_le, zero = cpu_to_le64(0);
268 unsigned int sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
269
270 /*
271 * We can't use a validator here - it may be all zeroes.
272 */
273 r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b);
274 if (r)
275 return r;
276
277 data_le = dm_block_data(b);
278 *result = true;
279 for (i = 0; i < sb_block_size; i++) {
280 if (data_le[i] != zero) {
281 *result = false;
282 break;
283 }
284 }
285
286 dm_bm_unlock(b);
287
288 return 0;
289}
290
291static void __setup_mapping_info(struct dm_cache_metadata *cmd)
292{
293 struct dm_btree_value_type vt;
294
295 vt.context = NULL;
296 vt.size = sizeof(__le64);
297 vt.inc = NULL;
298 vt.dec = NULL;
299 vt.equal = NULL;
300 dm_array_info_init(&cmd->info, cmd->tm, &vt);
301
302 if (cmd->policy_hint_size) {
303 vt.size = sizeof(__le32);
304 dm_array_info_init(&cmd->hint_info, cmd->tm, &vt);
305 }
306}
307
308static int __save_sm_root(struct dm_cache_metadata *cmd)
309{
310 int r;
311 size_t metadata_len;
312
313 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
314 if (r < 0)
315 return r;
316
317 return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
318 metadata_len);
319}
320
321static void __copy_sm_root(struct dm_cache_metadata *cmd,
322 struct cache_disk_superblock *disk_super)
323{
324 memcpy(&disk_super->metadata_space_map_root,
325 &cmd->metadata_space_map_root,
326 sizeof(cmd->metadata_space_map_root));
327}
328
329static bool separate_dirty_bits(struct dm_cache_metadata *cmd)
330{
331 return cmd->version >= 2;
332}
333
334static int __write_initial_superblock(struct dm_cache_metadata *cmd)
335{
336 int r;
337 struct dm_block *sblock;
338 struct cache_disk_superblock *disk_super;
339 sector_t bdev_size = bdev_nr_sectors(cmd->bdev);
340
341 /* FIXME: see if we can lose the max sectors limit */
342 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
343 bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
344
345 r = dm_tm_pre_commit(cmd->tm);
346 if (r < 0)
347 return r;
348
349 /*
350 * dm_sm_copy_root() can fail. So we need to do it before we start
351 * updating the superblock.
352 */
353 r = __save_sm_root(cmd);
354 if (r)
355 return r;
356
357 r = superblock_lock_zero(cmd, &sblock);
358 if (r)
359 return r;
360
361 disk_super = dm_block_data(sblock);
362 disk_super->flags = 0;
363 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
364 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
365 disk_super->version = cpu_to_le32(cmd->version);
366 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
367 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
368 disk_super->policy_hint_size = cpu_to_le32(0);
369
370 __copy_sm_root(cmd, disk_super);
371
372 disk_super->mapping_root = cpu_to_le64(cmd->root);
373 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
374 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
375 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
376 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
377 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE);
378 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
379 disk_super->cache_blocks = cpu_to_le32(0);
380
381 disk_super->read_hits = cpu_to_le32(0);
382 disk_super->read_misses = cpu_to_le32(0);
383 disk_super->write_hits = cpu_to_le32(0);
384 disk_super->write_misses = cpu_to_le32(0);
385
386 if (separate_dirty_bits(cmd))
387 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
388
389 return dm_tm_commit(cmd->tm, sblock);
390}
391
392static int __format_metadata(struct dm_cache_metadata *cmd)
393{
394 int r;
395
396 r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
397 &cmd->tm, &cmd->metadata_sm);
398 if (r < 0) {
399 DMERR("tm_create_with_sm failed");
400 return r;
401 }
402
403 __setup_mapping_info(cmd);
404
405 r = dm_array_empty(&cmd->info, &cmd->root);
406 if (r < 0)
407 goto bad;
408
409 if (separate_dirty_bits(cmd)) {
410 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info);
411 r = dm_bitset_empty(&cmd->dirty_info, &cmd->dirty_root);
412 if (r < 0)
413 goto bad;
414 }
415
416 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
417 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root);
418 if (r < 0)
419 goto bad;
420
421 cmd->discard_block_size = 0;
422 cmd->discard_nr_blocks = 0;
423
424 r = __write_initial_superblock(cmd);
425 if (r)
426 goto bad;
427
428 cmd->clean_when_opened = true;
429 return 0;
430
431bad:
432 dm_tm_destroy(cmd->tm);
433 dm_sm_destroy(cmd->metadata_sm);
434
435 return r;
436}
437
438static int __check_incompat_features(struct cache_disk_superblock *disk_super,
439 struct dm_cache_metadata *cmd)
440{
441 uint32_t incompat_flags, features;
442
443 incompat_flags = le32_to_cpu(disk_super->incompat_flags);
444 features = incompat_flags & ~DM_CACHE_FEATURE_INCOMPAT_SUPP;
445 if (features) {
446 DMERR("could not access metadata due to unsupported optional features (%lx).",
447 (unsigned long)features);
448 return -EINVAL;
449 }
450
451 /*
452 * Check for read-only metadata to skip the following RDWR checks.
453 */
454 if (bdev_read_only(cmd->bdev))
455 return 0;
456
457 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP;
458 if (features) {
459 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
460 (unsigned long)features);
461 return -EINVAL;
462 }
463
464 return 0;
465}
466
467static int __open_metadata(struct dm_cache_metadata *cmd)
468{
469 int r;
470 struct dm_block *sblock;
471 struct cache_disk_superblock *disk_super;
472 unsigned long sb_flags;
473
474 r = superblock_read_lock(cmd, &sblock);
475 if (r < 0) {
476 DMERR("couldn't read lock superblock");
477 return r;
478 }
479
480 disk_super = dm_block_data(sblock);
481
482 /* Verify the data block size hasn't changed */
483 if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) {
484 DMERR("changing the data block size (from %u to %llu) is not supported",
485 le32_to_cpu(disk_super->data_block_size),
486 (unsigned long long)cmd->data_block_size);
487 r = -EINVAL;
488 goto bad;
489 }
490
491 r = __check_incompat_features(disk_super, cmd);
492 if (r < 0)
493 goto bad;
494
495 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
496 disk_super->metadata_space_map_root,
497 sizeof(disk_super->metadata_space_map_root),
498 &cmd->tm, &cmd->metadata_sm);
499 if (r < 0) {
500 DMERR("tm_open_with_sm failed");
501 goto bad;
502 }
503
504 __setup_mapping_info(cmd);
505 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info);
506 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
507 sb_flags = le32_to_cpu(disk_super->flags);
508 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
509 dm_bm_unlock(sblock);
510
511 return 0;
512
513bad:
514 dm_bm_unlock(sblock);
515 return r;
516}
517
518static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
519 bool format_device)
520{
521 int r;
522 bool unformatted = false;
523
524 r = __superblock_all_zeroes(cmd->bm, &unformatted);
525 if (r)
526 return r;
527
528 if (unformatted)
529 return format_device ? __format_metadata(cmd) : -EPERM;
530
531 return __open_metadata(cmd);
532}
533
534static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
535 bool may_format_device)
536{
537 int r;
538
539 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
540 CACHE_MAX_CONCURRENT_LOCKS);
541 if (IS_ERR(cmd->bm)) {
542 DMERR("could not create block manager");
543 r = PTR_ERR(cmd->bm);
544 cmd->bm = NULL;
545 return r;
546 }
547
548 r = __open_or_format_metadata(cmd, may_format_device);
549 if (r) {
550 dm_block_manager_destroy(cmd->bm);
551 cmd->bm = NULL;
552 }
553
554 return r;
555}
556
557static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd,
558 bool destroy_bm)
559{
560 dm_sm_destroy(cmd->metadata_sm);
561 dm_tm_destroy(cmd->tm);
562 if (destroy_bm)
563 dm_block_manager_destroy(cmd->bm);
564}
565
566typedef unsigned long (*flags_mutator)(unsigned long);
567
568static void update_flags(struct cache_disk_superblock *disk_super,
569 flags_mutator mutator)
570{
571 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
572
573 disk_super->flags = cpu_to_le32(sb_flags);
574}
575
576static unsigned long set_clean_shutdown(unsigned long flags)
577{
578 set_bit(CLEAN_SHUTDOWN, &flags);
579 return flags;
580}
581
582static unsigned long clear_clean_shutdown(unsigned long flags)
583{
584 clear_bit(CLEAN_SHUTDOWN, &flags);
585 return flags;
586}
587
588static void read_superblock_fields(struct dm_cache_metadata *cmd,
589 struct cache_disk_superblock *disk_super)
590{
591 cmd->version = le32_to_cpu(disk_super->version);
592 cmd->flags = le32_to_cpu(disk_super->flags);
593 cmd->root = le64_to_cpu(disk_super->mapping_root);
594 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
595 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
596 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
597 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
598 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
599 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
600 strscpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
601 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
602 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
603 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
604 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
605
606 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
607 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
608 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
609 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
610
611 if (separate_dirty_bits(cmd))
612 cmd->dirty_root = le64_to_cpu(disk_super->dirty_root);
613
614 cmd->changed = false;
615}
616
617/*
618 * The mutator updates the superblock flags.
619 */
620static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
621 flags_mutator mutator)
622{
623 int r;
624 struct cache_disk_superblock *disk_super;
625 struct dm_block *sblock;
626
627 r = superblock_lock(cmd, &sblock);
628 if (r)
629 return r;
630
631 disk_super = dm_block_data(sblock);
632 update_flags(disk_super, mutator);
633 read_superblock_fields(cmd, disk_super);
634 dm_bm_unlock(sblock);
635
636 return dm_bm_flush(cmd->bm);
637}
638
639static int __begin_transaction(struct dm_cache_metadata *cmd)
640{
641 int r;
642 struct cache_disk_superblock *disk_super;
643 struct dm_block *sblock;
644
645 /*
646 * We re-read the superblock every time. Shouldn't need to do this
647 * really.
648 */
649 r = superblock_read_lock(cmd, &sblock);
650 if (r)
651 return r;
652
653 disk_super = dm_block_data(sblock);
654 read_superblock_fields(cmd, disk_super);
655 dm_bm_unlock(sblock);
656
657 return 0;
658}
659
660static int __commit_transaction(struct dm_cache_metadata *cmd,
661 flags_mutator mutator)
662{
663 int r;
664 struct cache_disk_superblock *disk_super;
665 struct dm_block *sblock;
666
667 /*
668 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
669 */
670 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
671
672 if (separate_dirty_bits(cmd)) {
673 r = dm_bitset_flush(&cmd->dirty_info, cmd->dirty_root,
674 &cmd->dirty_root);
675 if (r)
676 return r;
677 }
678
679 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
680 &cmd->discard_root);
681 if (r)
682 return r;
683
684 r = dm_tm_pre_commit(cmd->tm);
685 if (r < 0)
686 return r;
687
688 r = __save_sm_root(cmd);
689 if (r)
690 return r;
691
692 r = superblock_lock(cmd, &sblock);
693 if (r)
694 return r;
695
696 disk_super = dm_block_data(sblock);
697
698 disk_super->flags = cpu_to_le32(cmd->flags);
699 if (mutator)
700 update_flags(disk_super, mutator);
701
702 disk_super->mapping_root = cpu_to_le64(cmd->root);
703 if (separate_dirty_bits(cmd))
704 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
705 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
706 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
707 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
708 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
709 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
710 strscpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
711 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
712 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
713 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
714 disk_super->policy_hint_size = cpu_to_le32(cmd->policy_hint_size);
715
716 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
717 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
718 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
719 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
720 __copy_sm_root(cmd, disk_super);
721
722 return dm_tm_commit(cmd->tm, sblock);
723}
724
725/*----------------------------------------------------------------*/
726
727/*
728 * The mappings are held in a dm-array that has 64-bit values stored in
729 * little-endian format. The index is the cblock, the high 48bits of the
730 * value are the oblock and the low 16 bit the flags.
731 */
732#define FLAGS_MASK ((1 << 16) - 1)
733
734static __le64 pack_value(dm_oblock_t block, unsigned int flags)
735{
736 uint64_t value = from_oblock(block);
737
738 value <<= 16;
739 value = value | (flags & FLAGS_MASK);
740 return cpu_to_le64(value);
741}
742
743static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned int *flags)
744{
745 uint64_t value = le64_to_cpu(value_le);
746 uint64_t b = value >> 16;
747
748 *block = to_oblock(b);
749 *flags = value & FLAGS_MASK;
750}
751
752/*----------------------------------------------------------------*/
753
754static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
755 sector_t data_block_size,
756 bool may_format_device,
757 size_t policy_hint_size,
758 unsigned int metadata_version)
759{
760 int r;
761 struct dm_cache_metadata *cmd;
762
763 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
764 if (!cmd) {
765 DMERR("could not allocate metadata struct");
766 return ERR_PTR(-ENOMEM);
767 }
768
769 cmd->version = metadata_version;
770 refcount_set(&cmd->ref_count, 1);
771 init_rwsem(&cmd->root_lock);
772 cmd->bdev = bdev;
773 cmd->data_block_size = data_block_size;
774 cmd->cache_blocks = 0;
775 cmd->policy_hint_size = policy_hint_size;
776 cmd->changed = true;
777 cmd->fail_io = false;
778
779 r = __create_persistent_data_objects(cmd, may_format_device);
780 if (r) {
781 kfree(cmd);
782 return ERR_PTR(r);
783 }
784
785 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
786 if (r < 0) {
787 dm_cache_metadata_close(cmd);
788 return ERR_PTR(r);
789 }
790
791 return cmd;
792}
793
794/*
795 * We keep a little list of ref counted metadata objects to prevent two
796 * different target instances creating separate bufio instances. This is
797 * an issue if a table is reloaded before the suspend.
798 */
799static DEFINE_MUTEX(table_lock);
800static LIST_HEAD(table);
801
802static struct dm_cache_metadata *lookup(struct block_device *bdev)
803{
804 struct dm_cache_metadata *cmd;
805
806 list_for_each_entry(cmd, &table, list)
807 if (cmd->bdev == bdev) {
808 refcount_inc(&cmd->ref_count);
809 return cmd;
810 }
811
812 return NULL;
813}
814
815static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev,
816 sector_t data_block_size,
817 bool may_format_device,
818 size_t policy_hint_size,
819 unsigned int metadata_version)
820{
821 struct dm_cache_metadata *cmd, *cmd2;
822
823 mutex_lock(&table_lock);
824 cmd = lookup(bdev);
825 mutex_unlock(&table_lock);
826
827 if (cmd)
828 return cmd;
829
830 cmd = metadata_open(bdev, data_block_size, may_format_device,
831 policy_hint_size, metadata_version);
832 if (!IS_ERR(cmd)) {
833 mutex_lock(&table_lock);
834 cmd2 = lookup(bdev);
835 if (cmd2) {
836 mutex_unlock(&table_lock);
837 __destroy_persistent_data_objects(cmd, true);
838 kfree(cmd);
839 return cmd2;
840 }
841 list_add(&cmd->list, &table);
842 mutex_unlock(&table_lock);
843 }
844
845 return cmd;
846}
847
848static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size)
849{
850 if (cmd->data_block_size != data_block_size) {
851 DMERR("data_block_size (%llu) different from that in metadata (%llu)",
852 (unsigned long long) data_block_size,
853 (unsigned long long) cmd->data_block_size);
854 return false;
855 }
856
857 return true;
858}
859
860struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
861 sector_t data_block_size,
862 bool may_format_device,
863 size_t policy_hint_size,
864 unsigned int metadata_version)
865{
866 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, may_format_device,
867 policy_hint_size, metadata_version);
868
869 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) {
870 dm_cache_metadata_close(cmd);
871 return ERR_PTR(-EINVAL);
872 }
873
874 return cmd;
875}
876
877void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
878{
879 if (refcount_dec_and_test(&cmd->ref_count)) {
880 mutex_lock(&table_lock);
881 list_del(&cmd->list);
882 mutex_unlock(&table_lock);
883
884 if (!cmd->fail_io)
885 __destroy_persistent_data_objects(cmd, true);
886 kfree(cmd);
887 }
888}
889
890/*
891 * Checks that the given cache block is either unmapped or clean.
892 */
893static int block_clean_combined_dirty(struct dm_cache_metadata *cmd, dm_cblock_t b,
894 bool *result)
895{
896 int r;
897 __le64 value;
898 dm_oblock_t ob;
899 unsigned int flags;
900
901 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
902 if (r)
903 return r;
904
905 unpack_value(value, &ob, &flags);
906 *result = !((flags & M_VALID) && (flags & M_DIRTY));
907
908 return 0;
909}
910
911static int blocks_are_clean_combined_dirty(struct dm_cache_metadata *cmd,
912 dm_cblock_t begin, dm_cblock_t end,
913 bool *result)
914{
915 int r;
916 *result = true;
917
918 while (begin != end) {
919 r = block_clean_combined_dirty(cmd, begin, result);
920 if (r) {
921 DMERR("block_clean_combined_dirty failed");
922 return r;
923 }
924
925 if (!*result) {
926 DMERR("cache block %llu is dirty",
927 (unsigned long long) from_cblock(begin));
928 return 0;
929 }
930
931 begin = to_cblock(from_cblock(begin) + 1);
932 }
933
934 return 0;
935}
936
937static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd,
938 dm_cblock_t begin, dm_cblock_t end,
939 bool *result)
940{
941 int r;
942 bool dirty_flag;
943 *result = true;
944
945 if (from_cblock(cmd->cache_blocks) == 0)
946 /* Nothing to do */
947 return 0;
948
949 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
950 from_cblock(cmd->cache_blocks), &cmd->dirty_cursor);
951 if (r) {
952 DMERR("%s: dm_bitset_cursor_begin for dirty failed", __func__);
953 return r;
954 }
955
956 r = dm_bitset_cursor_skip(&cmd->dirty_cursor, from_cblock(begin));
957 if (r) {
958 DMERR("%s: dm_bitset_cursor_skip for dirty failed", __func__);
959 dm_bitset_cursor_end(&cmd->dirty_cursor);
960 return r;
961 }
962
963 while (begin != end) {
964 /*
965 * We assume that unmapped blocks have their dirty bit
966 * cleared.
967 */
968 dirty_flag = dm_bitset_cursor_get_value(&cmd->dirty_cursor);
969 if (dirty_flag) {
970 DMERR("%s: cache block %llu is dirty", __func__,
971 (unsigned long long) from_cblock(begin));
972 dm_bitset_cursor_end(&cmd->dirty_cursor);
973 *result = false;
974 return 0;
975 }
976
977 begin = to_cblock(from_cblock(begin) + 1);
978 if (begin == end)
979 break;
980
981 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
982 if (r) {
983 DMERR("%s: dm_bitset_cursor_next for dirty failed", __func__);
984 dm_bitset_cursor_end(&cmd->dirty_cursor);
985 return r;
986 }
987 }
988
989 dm_bitset_cursor_end(&cmd->dirty_cursor);
990
991 return 0;
992}
993
994static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
995 dm_cblock_t begin, dm_cblock_t end,
996 bool *result)
997{
998 if (separate_dirty_bits(cmd))
999 return blocks_are_clean_separate_dirty(cmd, begin, end, result);
1000 else
1001 return blocks_are_clean_combined_dirty(cmd, begin, end, result);
1002}
1003
1004static bool cmd_write_lock(struct dm_cache_metadata *cmd)
1005{
1006 down_write(&cmd->root_lock);
1007 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
1008 up_write(&cmd->root_lock);
1009 return false;
1010 }
1011 return true;
1012}
1013
1014#define WRITE_LOCK(cmd) \
1015 do { \
1016 if (!cmd_write_lock((cmd))) \
1017 return -EINVAL; \
1018 } while (0)
1019
1020#define WRITE_LOCK_VOID(cmd) \
1021 do { \
1022 if (!cmd_write_lock((cmd))) \
1023 return; \
1024 } while (0)
1025
1026#define WRITE_UNLOCK(cmd) \
1027 up_write(&(cmd)->root_lock)
1028
1029static bool cmd_read_lock(struct dm_cache_metadata *cmd)
1030{
1031 down_read(&cmd->root_lock);
1032 if (cmd->fail_io) {
1033 up_read(&cmd->root_lock);
1034 return false;
1035 }
1036 return true;
1037}
1038
1039#define READ_LOCK(cmd) \
1040 do { \
1041 if (!cmd_read_lock((cmd))) \
1042 return -EINVAL; \
1043 } while (0)
1044
1045#define READ_LOCK_VOID(cmd) \
1046 do { \
1047 if (!cmd_read_lock((cmd))) \
1048 return; \
1049 } while (0)
1050
1051#define READ_UNLOCK(cmd) \
1052 up_read(&(cmd)->root_lock)
1053
1054int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
1055{
1056 int r;
1057 bool clean;
1058 __le64 null_mapping = pack_value(0, 0);
1059
1060 WRITE_LOCK(cmd);
1061 __dm_bless_for_disk(&null_mapping);
1062
1063 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
1064 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
1065 if (r) {
1066 __dm_unbless_for_disk(&null_mapping);
1067 goto out;
1068 }
1069
1070 if (!clean) {
1071 DMERR("unable to shrink cache due to dirty blocks");
1072 r = -EINVAL;
1073 __dm_unbless_for_disk(&null_mapping);
1074 goto out;
1075 }
1076 }
1077
1078 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
1079 from_cblock(new_cache_size),
1080 &null_mapping, &cmd->root);
1081 if (r)
1082 goto out;
1083
1084 if (separate_dirty_bits(cmd)) {
1085 r = dm_bitset_resize(&cmd->dirty_info, cmd->dirty_root,
1086 from_cblock(cmd->cache_blocks), from_cblock(new_cache_size),
1087 false, &cmd->dirty_root);
1088 if (r)
1089 goto out;
1090 }
1091
1092 cmd->cache_blocks = new_cache_size;
1093 cmd->changed = true;
1094
1095out:
1096 WRITE_UNLOCK(cmd);
1097
1098 return r;
1099}
1100
1101int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
1102 sector_t discard_block_size,
1103 dm_dblock_t new_nr_entries)
1104{
1105 int r;
1106
1107 WRITE_LOCK(cmd);
1108 r = dm_bitset_resize(&cmd->discard_info,
1109 cmd->discard_root,
1110 from_dblock(cmd->discard_nr_blocks),
1111 from_dblock(new_nr_entries),
1112 false, &cmd->discard_root);
1113 if (!r) {
1114 cmd->discard_block_size = discard_block_size;
1115 cmd->discard_nr_blocks = new_nr_entries;
1116 }
1117
1118 cmd->changed = true;
1119 WRITE_UNLOCK(cmd);
1120
1121 return r;
1122}
1123
1124static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1125{
1126 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
1127 from_dblock(b), &cmd->discard_root);
1128}
1129
1130static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1131{
1132 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
1133 from_dblock(b), &cmd->discard_root);
1134}
1135
1136static int __discard(struct dm_cache_metadata *cmd,
1137 dm_dblock_t dblock, bool discard)
1138{
1139 int r;
1140
1141 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
1142 if (r)
1143 return r;
1144
1145 cmd->changed = true;
1146 return 0;
1147}
1148
1149int dm_cache_set_discard(struct dm_cache_metadata *cmd,
1150 dm_dblock_t dblock, bool discard)
1151{
1152 int r;
1153
1154 WRITE_LOCK(cmd);
1155 r = __discard(cmd, dblock, discard);
1156 WRITE_UNLOCK(cmd);
1157
1158 return r;
1159}
1160
1161static int __load_discards(struct dm_cache_metadata *cmd,
1162 load_discard_fn fn, void *context)
1163{
1164 int r = 0;
1165 uint32_t b;
1166 struct dm_bitset_cursor c;
1167
1168 if (from_dblock(cmd->discard_nr_blocks) == 0)
1169 /* nothing to do */
1170 return 0;
1171
1172 if (cmd->clean_when_opened) {
1173 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, &cmd->discard_root);
1174 if (r)
1175 return r;
1176
1177 r = dm_bitset_cursor_begin(&cmd->discard_info, cmd->discard_root,
1178 from_dblock(cmd->discard_nr_blocks), &c);
1179 if (r)
1180 return r;
1181
1182 for (b = 0; ; b++) {
1183 r = fn(context, cmd->discard_block_size, to_dblock(b),
1184 dm_bitset_cursor_get_value(&c));
1185 if (r)
1186 break;
1187
1188 if (b >= (from_dblock(cmd->discard_nr_blocks) - 1))
1189 break;
1190
1191 r = dm_bitset_cursor_next(&c);
1192 if (r)
1193 break;
1194 }
1195
1196 dm_bitset_cursor_end(&c);
1197
1198 } else {
1199 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
1200 r = fn(context, cmd->discard_block_size, to_dblock(b), false);
1201 if (r)
1202 return r;
1203 }
1204 }
1205
1206 return r;
1207}
1208
1209int dm_cache_load_discards(struct dm_cache_metadata *cmd,
1210 load_discard_fn fn, void *context)
1211{
1212 int r;
1213
1214 READ_LOCK(cmd);
1215 r = __load_discards(cmd, fn, context);
1216 READ_UNLOCK(cmd);
1217
1218 return r;
1219}
1220
1221static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1222{
1223 int r;
1224 __le64 value = pack_value(0, 0);
1225
1226 __dm_bless_for_disk(&value);
1227 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1228 &value, &cmd->root);
1229 if (r)
1230 return r;
1231
1232 cmd->changed = true;
1233 return 0;
1234}
1235
1236int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1237{
1238 int r;
1239
1240 WRITE_LOCK(cmd);
1241 r = __remove(cmd, cblock);
1242 WRITE_UNLOCK(cmd);
1243
1244 return r;
1245}
1246
1247static int __insert(struct dm_cache_metadata *cmd,
1248 dm_cblock_t cblock, dm_oblock_t oblock)
1249{
1250 int r;
1251 __le64 value = pack_value(oblock, M_VALID);
1252
1253 __dm_bless_for_disk(&value);
1254
1255 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1256 &value, &cmd->root);
1257 if (r)
1258 return r;
1259
1260 cmd->changed = true;
1261 return 0;
1262}
1263
1264int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
1265 dm_cblock_t cblock, dm_oblock_t oblock)
1266{
1267 int r;
1268
1269 WRITE_LOCK(cmd);
1270 r = __insert(cmd, cblock, oblock);
1271 WRITE_UNLOCK(cmd);
1272
1273 return r;
1274}
1275
1276static bool policy_unchanged(struct dm_cache_metadata *cmd,
1277 struct dm_cache_policy *policy)
1278{
1279 const char *policy_name = dm_cache_policy_get_name(policy);
1280 const unsigned int *policy_version = dm_cache_policy_get_version(policy);
1281 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
1282
1283 /*
1284 * Ensure policy names match.
1285 */
1286 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
1287 return false;
1288
1289 /*
1290 * Ensure policy major versions match.
1291 */
1292 if (cmd->policy_version[0] != policy_version[0])
1293 return false;
1294
1295 /*
1296 * Ensure policy hint sizes match.
1297 */
1298 if (cmd->policy_hint_size != policy_hint_size)
1299 return false;
1300
1301 return true;
1302}
1303
1304static bool hints_array_initialized(struct dm_cache_metadata *cmd)
1305{
1306 return cmd->hint_root && cmd->policy_hint_size;
1307}
1308
1309static bool hints_array_available(struct dm_cache_metadata *cmd,
1310 struct dm_cache_policy *policy)
1311{
1312 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
1313 hints_array_initialized(cmd);
1314}
1315
1316static int __load_mapping_v1(struct dm_cache_metadata *cmd,
1317 uint64_t cb, bool hints_valid,
1318 struct dm_array_cursor *mapping_cursor,
1319 struct dm_array_cursor *hint_cursor,
1320 load_mapping_fn fn, void *context)
1321{
1322 int r = 0;
1323
1324 __le64 mapping;
1325 __le32 hint = 0;
1326
1327 __le64 *mapping_value_le;
1328 __le32 *hint_value_le;
1329
1330 dm_oblock_t oblock;
1331 unsigned int flags;
1332 bool dirty = true;
1333
1334 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1335 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1336 unpack_value(mapping, &oblock, &flags);
1337
1338 if (flags & M_VALID) {
1339 if (hints_valid) {
1340 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1341 memcpy(&hint, hint_value_le, sizeof(hint));
1342 }
1343 if (cmd->clean_when_opened)
1344 dirty = flags & M_DIRTY;
1345
1346 r = fn(context, oblock, to_cblock(cb), dirty,
1347 le32_to_cpu(hint), hints_valid);
1348 if (r) {
1349 DMERR("policy couldn't load cache block %llu",
1350 (unsigned long long) from_cblock(to_cblock(cb)));
1351 }
1352 }
1353
1354 return r;
1355}
1356
1357static int __load_mapping_v2(struct dm_cache_metadata *cmd,
1358 uint64_t cb, bool hints_valid,
1359 struct dm_array_cursor *mapping_cursor,
1360 struct dm_array_cursor *hint_cursor,
1361 struct dm_bitset_cursor *dirty_cursor,
1362 load_mapping_fn fn, void *context)
1363{
1364 int r = 0;
1365
1366 __le64 mapping;
1367 __le32 hint = 0;
1368
1369 __le64 *mapping_value_le;
1370 __le32 *hint_value_le;
1371
1372 dm_oblock_t oblock;
1373 unsigned int flags;
1374 bool dirty = true;
1375
1376 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1377 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1378 unpack_value(mapping, &oblock, &flags);
1379
1380 if (flags & M_VALID) {
1381 if (hints_valid) {
1382 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1383 memcpy(&hint, hint_value_le, sizeof(hint));
1384 }
1385 if (cmd->clean_when_opened)
1386 dirty = dm_bitset_cursor_get_value(dirty_cursor);
1387
1388 r = fn(context, oblock, to_cblock(cb), dirty,
1389 le32_to_cpu(hint), hints_valid);
1390 if (r) {
1391 DMERR("policy couldn't load cache block %llu",
1392 (unsigned long long) from_cblock(to_cblock(cb)));
1393 }
1394 }
1395
1396 return r;
1397}
1398
1399static int __load_mappings(struct dm_cache_metadata *cmd,
1400 struct dm_cache_policy *policy,
1401 load_mapping_fn fn, void *context)
1402{
1403 int r;
1404 uint64_t cb;
1405
1406 bool hints_valid = hints_array_available(cmd, policy);
1407
1408 if (from_cblock(cmd->cache_blocks) == 0)
1409 /* Nothing to do */
1410 return 0;
1411
1412 r = dm_array_cursor_begin(&cmd->info, cmd->root, &cmd->mapping_cursor);
1413 if (r)
1414 return r;
1415
1416 if (hints_valid) {
1417 r = dm_array_cursor_begin(&cmd->hint_info, cmd->hint_root, &cmd->hint_cursor);
1418 if (r) {
1419 dm_array_cursor_end(&cmd->mapping_cursor);
1420 return r;
1421 }
1422 }
1423
1424 if (separate_dirty_bits(cmd)) {
1425 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
1426 from_cblock(cmd->cache_blocks),
1427 &cmd->dirty_cursor);
1428 if (r) {
1429 dm_array_cursor_end(&cmd->hint_cursor);
1430 dm_array_cursor_end(&cmd->mapping_cursor);
1431 return r;
1432 }
1433 }
1434
1435 for (cb = 0; ; cb++) {
1436 if (separate_dirty_bits(cmd))
1437 r = __load_mapping_v2(cmd, cb, hints_valid,
1438 &cmd->mapping_cursor,
1439 &cmd->hint_cursor,
1440 &cmd->dirty_cursor,
1441 fn, context);
1442 else
1443 r = __load_mapping_v1(cmd, cb, hints_valid,
1444 &cmd->mapping_cursor, &cmd->hint_cursor,
1445 fn, context);
1446 if (r)
1447 goto out;
1448
1449 /*
1450 * We need to break out before we move the cursors.
1451 */
1452 if (cb >= (from_cblock(cmd->cache_blocks) - 1))
1453 break;
1454
1455 r = dm_array_cursor_next(&cmd->mapping_cursor);
1456 if (r) {
1457 DMERR("dm_array_cursor_next for mapping failed");
1458 goto out;
1459 }
1460
1461 if (hints_valid) {
1462 r = dm_array_cursor_next(&cmd->hint_cursor);
1463 if (r) {
1464 dm_array_cursor_end(&cmd->hint_cursor);
1465 hints_valid = false;
1466 }
1467 }
1468
1469 if (separate_dirty_bits(cmd)) {
1470 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
1471 if (r) {
1472 DMERR("dm_bitset_cursor_next for dirty failed");
1473 goto out;
1474 }
1475 }
1476 }
1477out:
1478 dm_array_cursor_end(&cmd->mapping_cursor);
1479 if (hints_valid)
1480 dm_array_cursor_end(&cmd->hint_cursor);
1481
1482 if (separate_dirty_bits(cmd))
1483 dm_bitset_cursor_end(&cmd->dirty_cursor);
1484
1485 return r;
1486}
1487
1488int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
1489 struct dm_cache_policy *policy,
1490 load_mapping_fn fn, void *context)
1491{
1492 int r;
1493
1494 READ_LOCK(cmd);
1495 r = __load_mappings(cmd, policy, fn, context);
1496 READ_UNLOCK(cmd);
1497
1498 return r;
1499}
1500
1501int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1502{
1503 int r;
1504
1505 READ_LOCK(cmd);
1506 r = cmd->changed;
1507 READ_UNLOCK(cmd);
1508
1509 return r;
1510}
1511
1512static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1513{
1514 int r;
1515 unsigned int flags;
1516 dm_oblock_t oblock;
1517 __le64 value;
1518
1519 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1520 if (r)
1521 return r;
1522
1523 unpack_value(value, &oblock, &flags);
1524
1525 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1526 /* nothing to be done */
1527 return 0;
1528
1529 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
1530 __dm_bless_for_disk(&value);
1531
1532 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1533 &value, &cmd->root);
1534 if (r)
1535 return r;
1536
1537 cmd->changed = true;
1538 return 0;
1539
1540}
1541
1542static int __set_dirty_bits_v1(struct dm_cache_metadata *cmd, unsigned int nr_bits, unsigned long *bits)
1543{
1544 int r;
1545 unsigned int i;
1546
1547 for (i = 0; i < nr_bits; i++) {
1548 r = __dirty(cmd, to_cblock(i), test_bit(i, bits));
1549 if (r)
1550 return r;
1551 }
1552
1553 return 0;
1554}
1555
1556static int is_dirty_callback(uint32_t index, bool *value, void *context)
1557{
1558 unsigned long *bits = context;
1559 *value = test_bit(index, bits);
1560 return 0;
1561}
1562
1563static int __set_dirty_bits_v2(struct dm_cache_metadata *cmd, unsigned int nr_bits, unsigned long *bits)
1564{
1565 int r = 0;
1566
1567 /* nr_bits is really just a sanity check */
1568 if (nr_bits != from_cblock(cmd->cache_blocks)) {
1569 DMERR("dirty bitset is wrong size");
1570 return -EINVAL;
1571 }
1572
1573 r = dm_bitset_del(&cmd->dirty_info, cmd->dirty_root);
1574 if (r)
1575 return r;
1576
1577 cmd->changed = true;
1578 return dm_bitset_new(&cmd->dirty_info, &cmd->dirty_root, nr_bits, is_dirty_callback, bits);
1579}
1580
1581int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd,
1582 unsigned int nr_bits,
1583 unsigned long *bits)
1584{
1585 int r;
1586
1587 WRITE_LOCK(cmd);
1588 if (separate_dirty_bits(cmd))
1589 r = __set_dirty_bits_v2(cmd, nr_bits, bits);
1590 else
1591 r = __set_dirty_bits_v1(cmd, nr_bits, bits);
1592 WRITE_UNLOCK(cmd);
1593
1594 return r;
1595}
1596
1597void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1598 struct dm_cache_statistics *stats)
1599{
1600 READ_LOCK_VOID(cmd);
1601 *stats = cmd->stats;
1602 READ_UNLOCK(cmd);
1603}
1604
1605void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1606 struct dm_cache_statistics *stats)
1607{
1608 WRITE_LOCK_VOID(cmd);
1609 cmd->stats = *stats;
1610 WRITE_UNLOCK(cmd);
1611}
1612
1613int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1614{
1615 int r = -EINVAL;
1616 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1617 clear_clean_shutdown);
1618
1619 WRITE_LOCK(cmd);
1620 if (cmd->fail_io)
1621 goto out;
1622
1623 r = __commit_transaction(cmd, mutator);
1624 if (r)
1625 goto out;
1626
1627 r = __begin_transaction(cmd);
1628out:
1629 WRITE_UNLOCK(cmd);
1630 return r;
1631}
1632
1633int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1634 dm_block_t *result)
1635{
1636 int r = -EINVAL;
1637
1638 READ_LOCK(cmd);
1639 if (!cmd->fail_io)
1640 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1641 READ_UNLOCK(cmd);
1642
1643 return r;
1644}
1645
1646int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1647 dm_block_t *result)
1648{
1649 int r = -EINVAL;
1650
1651 READ_LOCK(cmd);
1652 if (!cmd->fail_io)
1653 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1654 READ_UNLOCK(cmd);
1655
1656 return r;
1657}
1658
1659/*----------------------------------------------------------------*/
1660
1661static int get_hint(uint32_t index, void *value_le, void *context)
1662{
1663 uint32_t value;
1664 struct dm_cache_policy *policy = context;
1665
1666 value = policy_get_hint(policy, to_cblock(index));
1667 *((__le32 *) value_le) = cpu_to_le32(value);
1668
1669 return 0;
1670}
1671
1672/*
1673 * It's quicker to always delete the hint array, and recreate with
1674 * dm_array_new().
1675 */
1676static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1677{
1678 int r;
1679 size_t hint_size;
1680 const char *policy_name = dm_cache_policy_get_name(policy);
1681 const unsigned int *policy_version = dm_cache_policy_get_version(policy);
1682
1683 if (!policy_name[0] ||
1684 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1685 return -EINVAL;
1686
1687 strscpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
1688 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
1689
1690 hint_size = dm_cache_policy_get_hint_size(policy);
1691 if (!hint_size)
1692 return 0; /* short-circuit hints initialization */
1693 cmd->policy_hint_size = hint_size;
1694
1695 if (cmd->hint_root) {
1696 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1697 if (r)
1698 return r;
1699 }
1700
1701 return dm_array_new(&cmd->hint_info, &cmd->hint_root,
1702 from_cblock(cmd->cache_blocks),
1703 get_hint, policy);
1704}
1705
1706int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1707{
1708 int r;
1709
1710 WRITE_LOCK(cmd);
1711 r = write_hints(cmd, policy);
1712 WRITE_UNLOCK(cmd);
1713
1714 return r;
1715}
1716
1717int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
1718{
1719 int r;
1720
1721 READ_LOCK(cmd);
1722 r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
1723 READ_UNLOCK(cmd);
1724
1725 return r;
1726}
1727
1728void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
1729{
1730 WRITE_LOCK_VOID(cmd);
1731 dm_bm_set_read_only(cmd->bm);
1732 WRITE_UNLOCK(cmd);
1733}
1734
1735void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
1736{
1737 WRITE_LOCK_VOID(cmd);
1738 dm_bm_set_read_write(cmd->bm);
1739 WRITE_UNLOCK(cmd);
1740}
1741
1742int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
1743{
1744 int r;
1745 struct dm_block *sblock;
1746 struct cache_disk_superblock *disk_super;
1747
1748 WRITE_LOCK(cmd);
1749 set_bit(NEEDS_CHECK, &cmd->flags);
1750
1751 r = superblock_lock(cmd, &sblock);
1752 if (r) {
1753 DMERR("couldn't read superblock");
1754 goto out;
1755 }
1756
1757 disk_super = dm_block_data(sblock);
1758 disk_super->flags = cpu_to_le32(cmd->flags);
1759
1760 dm_bm_unlock(sblock);
1761
1762out:
1763 WRITE_UNLOCK(cmd);
1764 return r;
1765}
1766
1767int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result)
1768{
1769 READ_LOCK(cmd);
1770 *result = !!test_bit(NEEDS_CHECK, &cmd->flags);
1771 READ_UNLOCK(cmd);
1772
1773 return 0;
1774}
1775
1776int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
1777{
1778 int r = -EINVAL;
1779 struct dm_block_manager *old_bm = NULL, *new_bm = NULL;
1780
1781 /* fail_io is double-checked with cmd->root_lock held below */
1782 if (unlikely(cmd->fail_io))
1783 return r;
1784
1785 /*
1786 * Replacement block manager (new_bm) is created and old_bm destroyed outside of
1787 * cmd root_lock to avoid ABBA deadlock that would result (due to life-cycle of
1788 * shrinker associated with the block manager's bufio client vs cmd root_lock).
1789 * - must take shrinker_mutex without holding cmd->root_lock
1790 */
1791 new_bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
1792 CACHE_MAX_CONCURRENT_LOCKS);
1793
1794 WRITE_LOCK(cmd);
1795 if (cmd->fail_io) {
1796 WRITE_UNLOCK(cmd);
1797 goto out;
1798 }
1799
1800 __destroy_persistent_data_objects(cmd, false);
1801 old_bm = cmd->bm;
1802 if (IS_ERR(new_bm)) {
1803 DMERR("could not create block manager during abort");
1804 cmd->bm = NULL;
1805 r = PTR_ERR(new_bm);
1806 goto out_unlock;
1807 }
1808
1809 cmd->bm = new_bm;
1810 r = __open_or_format_metadata(cmd, false);
1811 if (r) {
1812 cmd->bm = NULL;
1813 goto out_unlock;
1814 }
1815 new_bm = NULL;
1816out_unlock:
1817 if (r)
1818 cmd->fail_io = true;
1819 WRITE_UNLOCK(cmd);
1820 dm_block_manager_destroy(old_bm);
1821out:
1822 if (new_bm && !IS_ERR(new_bm))
1823 dm_block_manager_destroy(new_bm);
1824
1825 return r;
1826}