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 = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
338
339 /* FIXME: see if we can lose the max sectors limit */
340 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
341 bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
342
343 r = dm_tm_pre_commit(cmd->tm);
344 if (r < 0)
345 return r;
346
347 /*
348 * dm_sm_copy_root() can fail. So we need to do it before we start
349 * updating the superblock.
350 */
351 r = __save_sm_root(cmd);
352 if (r)
353 return r;
354
355 r = superblock_lock_zero(cmd, &sblock);
356 if (r)
357 return r;
358
359 disk_super = dm_block_data(sblock);
360 disk_super->flags = 0;
361 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
362 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
363 disk_super->version = cpu_to_le32(cmd->version);
364 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
365 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
366 disk_super->policy_hint_size = cpu_to_le32(0);
367
368 __copy_sm_root(cmd, disk_super);
369
370 disk_super->mapping_root = cpu_to_le64(cmd->root);
371 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
372 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
373 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
374 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
375 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE);
376 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
377 disk_super->cache_blocks = cpu_to_le32(0);
378
379 disk_super->read_hits = cpu_to_le32(0);
380 disk_super->read_misses = cpu_to_le32(0);
381 disk_super->write_hits = cpu_to_le32(0);
382 disk_super->write_misses = cpu_to_le32(0);
383
384 if (separate_dirty_bits(cmd))
385 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
386
387 return dm_tm_commit(cmd->tm, sblock);
388}
389
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 (get_disk_ro(cmd->bdev->bd_disk))
453 return 0;
454
455 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP;
456 if (features) {
457 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
458 (unsigned long)features);
459 return -EINVAL;
460 }
461
462 return 0;
463}
464
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 return PTR_ERR(cmd->bm);
541 }
542
543 r = __open_or_format_metadata(cmd, may_format_device);
544 if (r)
545 dm_block_manager_destroy(cmd->bm);
546
547 return r;
548}
549
550static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd)
551{
552 dm_sm_destroy(cmd->metadata_sm);
553 dm_tm_destroy(cmd->tm);
554 dm_block_manager_destroy(cmd->bm);
555}
556
557typedef unsigned long (*flags_mutator)(unsigned long);
558
559static void update_flags(struct cache_disk_superblock *disk_super,
560 flags_mutator mutator)
561{
562 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
563 disk_super->flags = cpu_to_le32(sb_flags);
564}
565
566static unsigned long set_clean_shutdown(unsigned long flags)
567{
568 set_bit(CLEAN_SHUTDOWN, &flags);
569 return flags;
570}
571
572static unsigned long clear_clean_shutdown(unsigned long flags)
573{
574 clear_bit(CLEAN_SHUTDOWN, &flags);
575 return flags;
576}
577
578static void read_superblock_fields(struct dm_cache_metadata *cmd,
579 struct cache_disk_superblock *disk_super)
580{
581 cmd->version = le32_to_cpu(disk_super->version);
582 cmd->flags = le32_to_cpu(disk_super->flags);
583 cmd->root = le64_to_cpu(disk_super->mapping_root);
584 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
585 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
586 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
587 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
588 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
589 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
590 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
591 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
592 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
593 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
594 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
595
596 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
597 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
598 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
599 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
600
601 if (separate_dirty_bits(cmd))
602 cmd->dirty_root = le64_to_cpu(disk_super->dirty_root);
603
604 cmd->changed = false;
605}
606
607/*
608 * The mutator updates the superblock flags.
609 */
610static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
611 flags_mutator mutator)
612{
613 int r;
614 struct cache_disk_superblock *disk_super;
615 struct dm_block *sblock;
616
617 r = superblock_lock(cmd, &sblock);
618 if (r)
619 return r;
620
621 disk_super = dm_block_data(sblock);
622 update_flags(disk_super, mutator);
623 read_superblock_fields(cmd, disk_super);
624 dm_bm_unlock(sblock);
625
626 return dm_bm_flush(cmd->bm);
627}
628
629static int __begin_transaction(struct dm_cache_metadata *cmd)
630{
631 int r;
632 struct cache_disk_superblock *disk_super;
633 struct dm_block *sblock;
634
635 /*
636 * We re-read the superblock every time. Shouldn't need to do this
637 * really.
638 */
639 r = superblock_read_lock(cmd, &sblock);
640 if (r)
641 return r;
642
643 disk_super = dm_block_data(sblock);
644 read_superblock_fields(cmd, disk_super);
645 dm_bm_unlock(sblock);
646
647 return 0;
648}
649
650static int __commit_transaction(struct dm_cache_metadata *cmd,
651 flags_mutator mutator)
652{
653 int r;
654 struct cache_disk_superblock *disk_super;
655 struct dm_block *sblock;
656
657 /*
658 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
659 */
660 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
661
662 if (separate_dirty_bits(cmd)) {
663 r = dm_bitset_flush(&cmd->dirty_info, cmd->dirty_root,
664 &cmd->dirty_root);
665 if (r)
666 return r;
667 }
668
669 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
670 &cmd->discard_root);
671 if (r)
672 return r;
673
674 r = dm_tm_pre_commit(cmd->tm);
675 if (r < 0)
676 return r;
677
678 r = __save_sm_root(cmd);
679 if (r)
680 return r;
681
682 r = superblock_lock(cmd, &sblock);
683 if (r)
684 return r;
685
686 disk_super = dm_block_data(sblock);
687
688 disk_super->flags = cpu_to_le32(cmd->flags);
689 if (mutator)
690 update_flags(disk_super, mutator);
691
692 disk_super->mapping_root = cpu_to_le64(cmd->root);
693 if (separate_dirty_bits(cmd))
694 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
695 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
696 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
697 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
698 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
699 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
700 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
701 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
702 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
703 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
704 disk_super->policy_hint_size = cpu_to_le32(cmd->policy_hint_size);
705
706 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
707 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
708 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
709 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
710 __copy_sm_root(cmd, disk_super);
711
712 return dm_tm_commit(cmd->tm, sblock);
713}
714
715/*----------------------------------------------------------------*/
716
717/*
718 * The mappings are held in a dm-array that has 64-bit values stored in
719 * little-endian format. The index is the cblock, the high 48bits of the
720 * value are the oblock and the low 16 bit the flags.
721 */
722#define FLAGS_MASK ((1 << 16) - 1)
723
724static __le64 pack_value(dm_oblock_t block, unsigned flags)
725{
726 uint64_t value = from_oblock(block);
727 value <<= 16;
728 value = value | (flags & FLAGS_MASK);
729 return cpu_to_le64(value);
730}
731
732static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
733{
734 uint64_t value = le64_to_cpu(value_le);
735 uint64_t b = value >> 16;
736 *block = to_oblock(b);
737 *flags = value & FLAGS_MASK;
738}
739
740/*----------------------------------------------------------------*/
741
742static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
743 sector_t data_block_size,
744 bool may_format_device,
745 size_t policy_hint_size,
746 unsigned metadata_version)
747{
748 int r;
749 struct dm_cache_metadata *cmd;
750
751 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
752 if (!cmd) {
753 DMERR("could not allocate metadata struct");
754 return ERR_PTR(-ENOMEM);
755 }
756
757 cmd->version = metadata_version;
758 refcount_set(&cmd->ref_count, 1);
759 init_rwsem(&cmd->root_lock);
760 cmd->bdev = bdev;
761 cmd->data_block_size = data_block_size;
762 cmd->cache_blocks = 0;
763 cmd->policy_hint_size = policy_hint_size;
764 cmd->changed = true;
765 cmd->fail_io = false;
766
767 r = __create_persistent_data_objects(cmd, may_format_device);
768 if (r) {
769 kfree(cmd);
770 return ERR_PTR(r);
771 }
772
773 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
774 if (r < 0) {
775 dm_cache_metadata_close(cmd);
776 return ERR_PTR(r);
777 }
778
779 return cmd;
780}
781
782/*
783 * We keep a little list of ref counted metadata objects to prevent two
784 * different target instances creating separate bufio instances. This is
785 * an issue if a table is reloaded before the suspend.
786 */
787static DEFINE_MUTEX(table_lock);
788static LIST_HEAD(table);
789
790static struct dm_cache_metadata *lookup(struct block_device *bdev)
791{
792 struct dm_cache_metadata *cmd;
793
794 list_for_each_entry(cmd, &table, list)
795 if (cmd->bdev == bdev) {
796 refcount_inc(&cmd->ref_count);
797 return cmd;
798 }
799
800 return NULL;
801}
802
803static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev,
804 sector_t data_block_size,
805 bool may_format_device,
806 size_t policy_hint_size,
807 unsigned metadata_version)
808{
809 struct dm_cache_metadata *cmd, *cmd2;
810
811 mutex_lock(&table_lock);
812 cmd = lookup(bdev);
813 mutex_unlock(&table_lock);
814
815 if (cmd)
816 return cmd;
817
818 cmd = metadata_open(bdev, data_block_size, may_format_device,
819 policy_hint_size, metadata_version);
820 if (!IS_ERR(cmd)) {
821 mutex_lock(&table_lock);
822 cmd2 = lookup(bdev);
823 if (cmd2) {
824 mutex_unlock(&table_lock);
825 __destroy_persistent_data_objects(cmd);
826 kfree(cmd);
827 return cmd2;
828 }
829 list_add(&cmd->list, &table);
830 mutex_unlock(&table_lock);
831 }
832
833 return cmd;
834}
835
836static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size)
837{
838 if (cmd->data_block_size != data_block_size) {
839 DMERR("data_block_size (%llu) different from that in metadata (%llu)",
840 (unsigned long long) data_block_size,
841 (unsigned long long) cmd->data_block_size);
842 return false;
843 }
844
845 return true;
846}
847
848struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
849 sector_t data_block_size,
850 bool may_format_device,
851 size_t policy_hint_size,
852 unsigned metadata_version)
853{
854 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, may_format_device,
855 policy_hint_size, metadata_version);
856
857 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) {
858 dm_cache_metadata_close(cmd);
859 return ERR_PTR(-EINVAL);
860 }
861
862 return cmd;
863}
864
865void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
866{
867 if (refcount_dec_and_test(&cmd->ref_count)) {
868 mutex_lock(&table_lock);
869 list_del(&cmd->list);
870 mutex_unlock(&table_lock);
871
872 if (!cmd->fail_io)
873 __destroy_persistent_data_objects(cmd);
874 kfree(cmd);
875 }
876}
877
878/*
879 * Checks that the given cache block is either unmapped or clean.
880 */
881static int block_clean_combined_dirty(struct dm_cache_metadata *cmd, dm_cblock_t b,
882 bool *result)
883{
884 int r;
885 __le64 value;
886 dm_oblock_t ob;
887 unsigned flags;
888
889 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
890 if (r)
891 return r;
892
893 unpack_value(value, &ob, &flags);
894 *result = !((flags & M_VALID) && (flags & M_DIRTY));
895
896 return 0;
897}
898
899static int blocks_are_clean_combined_dirty(struct dm_cache_metadata *cmd,
900 dm_cblock_t begin, dm_cblock_t end,
901 bool *result)
902{
903 int r;
904 *result = true;
905
906 while (begin != end) {
907 r = block_clean_combined_dirty(cmd, begin, result);
908 if (r) {
909 DMERR("block_clean_combined_dirty failed");
910 return r;
911 }
912
913 if (!*result) {
914 DMERR("cache block %llu is dirty",
915 (unsigned long long) from_cblock(begin));
916 return 0;
917 }
918
919 begin = to_cblock(from_cblock(begin) + 1);
920 }
921
922 return 0;
923}
924
925static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd,
926 dm_cblock_t begin, dm_cblock_t end,
927 bool *result)
928{
929 int r;
930 bool dirty_flag;
931 *result = true;
932
933 if (from_cblock(cmd->cache_blocks) == 0)
934 /* Nothing to do */
935 return 0;
936
937 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
938 from_cblock(cmd->cache_blocks), &cmd->dirty_cursor);
939 if (r) {
940 DMERR("%s: dm_bitset_cursor_begin for dirty failed", __func__);
941 return r;
942 }
943
944 r = dm_bitset_cursor_skip(&cmd->dirty_cursor, from_cblock(begin));
945 if (r) {
946 DMERR("%s: dm_bitset_cursor_skip for dirty failed", __func__);
947 dm_bitset_cursor_end(&cmd->dirty_cursor);
948 return r;
949 }
950
951 while (begin != end) {
952 /*
953 * We assume that unmapped blocks have their dirty bit
954 * cleared.
955 */
956 dirty_flag = dm_bitset_cursor_get_value(&cmd->dirty_cursor);
957 if (dirty_flag) {
958 DMERR("%s: cache block %llu is dirty", __func__,
959 (unsigned long long) from_cblock(begin));
960 dm_bitset_cursor_end(&cmd->dirty_cursor);
961 *result = false;
962 return 0;
963 }
964
965 begin = to_cblock(from_cblock(begin) + 1);
966 if (begin == end)
967 break;
968
969 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
970 if (r) {
971 DMERR("%s: dm_bitset_cursor_next for dirty failed", __func__);
972 dm_bitset_cursor_end(&cmd->dirty_cursor);
973 return r;
974 }
975 }
976
977 dm_bitset_cursor_end(&cmd->dirty_cursor);
978
979 return 0;
980}
981
982static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
983 dm_cblock_t begin, dm_cblock_t end,
984 bool *result)
985{
986 if (separate_dirty_bits(cmd))
987 return blocks_are_clean_separate_dirty(cmd, begin, end, result);
988 else
989 return blocks_are_clean_combined_dirty(cmd, begin, end, result);
990}
991
992static bool cmd_write_lock(struct dm_cache_metadata *cmd)
993{
994 down_write(&cmd->root_lock);
995 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
996 up_write(&cmd->root_lock);
997 return false;
998 }
999 return true;
1000}
1001
1002#define WRITE_LOCK(cmd) \
1003 do { \
1004 if (!cmd_write_lock((cmd))) \
1005 return -EINVAL; \
1006 } while(0)
1007
1008#define WRITE_LOCK_VOID(cmd) \
1009 do { \
1010 if (!cmd_write_lock((cmd))) \
1011 return; \
1012 } while(0)
1013
1014#define WRITE_UNLOCK(cmd) \
1015 up_write(&(cmd)->root_lock)
1016
1017static bool cmd_read_lock(struct dm_cache_metadata *cmd)
1018{
1019 down_read(&cmd->root_lock);
1020 if (cmd->fail_io) {
1021 up_read(&cmd->root_lock);
1022 return false;
1023 }
1024 return true;
1025}
1026
1027#define READ_LOCK(cmd) \
1028 do { \
1029 if (!cmd_read_lock((cmd))) \
1030 return -EINVAL; \
1031 } while(0)
1032
1033#define READ_LOCK_VOID(cmd) \
1034 do { \
1035 if (!cmd_read_lock((cmd))) \
1036 return; \
1037 } while(0)
1038
1039#define READ_UNLOCK(cmd) \
1040 up_read(&(cmd)->root_lock)
1041
1042int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
1043{
1044 int r;
1045 bool clean;
1046 __le64 null_mapping = pack_value(0, 0);
1047
1048 WRITE_LOCK(cmd);
1049 __dm_bless_for_disk(&null_mapping);
1050
1051 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
1052 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
1053 if (r) {
1054 __dm_unbless_for_disk(&null_mapping);
1055 goto out;
1056 }
1057
1058 if (!clean) {
1059 DMERR("unable to shrink cache due to dirty blocks");
1060 r = -EINVAL;
1061 __dm_unbless_for_disk(&null_mapping);
1062 goto out;
1063 }
1064 }
1065
1066 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
1067 from_cblock(new_cache_size),
1068 &null_mapping, &cmd->root);
1069 if (r)
1070 goto out;
1071
1072 if (separate_dirty_bits(cmd)) {
1073 r = dm_bitset_resize(&cmd->dirty_info, cmd->dirty_root,
1074 from_cblock(cmd->cache_blocks), from_cblock(new_cache_size),
1075 false, &cmd->dirty_root);
1076 if (r)
1077 goto out;
1078 }
1079
1080 cmd->cache_blocks = new_cache_size;
1081 cmd->changed = true;
1082
1083out:
1084 WRITE_UNLOCK(cmd);
1085
1086 return r;
1087}
1088
1089int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
1090 sector_t discard_block_size,
1091 dm_dblock_t new_nr_entries)
1092{
1093 int r;
1094
1095 WRITE_LOCK(cmd);
1096 r = dm_bitset_resize(&cmd->discard_info,
1097 cmd->discard_root,
1098 from_dblock(cmd->discard_nr_blocks),
1099 from_dblock(new_nr_entries),
1100 false, &cmd->discard_root);
1101 if (!r) {
1102 cmd->discard_block_size = discard_block_size;
1103 cmd->discard_nr_blocks = new_nr_entries;
1104 }
1105
1106 cmd->changed = true;
1107 WRITE_UNLOCK(cmd);
1108
1109 return r;
1110}
1111
1112static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1113{
1114 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
1115 from_dblock(b), &cmd->discard_root);
1116}
1117
1118static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1119{
1120 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
1121 from_dblock(b), &cmd->discard_root);
1122}
1123
1124static int __discard(struct dm_cache_metadata *cmd,
1125 dm_dblock_t dblock, bool discard)
1126{
1127 int r;
1128
1129 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
1130 if (r)
1131 return r;
1132
1133 cmd->changed = true;
1134 return 0;
1135}
1136
1137int dm_cache_set_discard(struct dm_cache_metadata *cmd,
1138 dm_dblock_t dblock, bool discard)
1139{
1140 int r;
1141
1142 WRITE_LOCK(cmd);
1143 r = __discard(cmd, dblock, discard);
1144 WRITE_UNLOCK(cmd);
1145
1146 return r;
1147}
1148
1149static int __load_discards(struct dm_cache_metadata *cmd,
1150 load_discard_fn fn, void *context)
1151{
1152 int r = 0;
1153 uint32_t b;
1154 struct dm_bitset_cursor c;
1155
1156 if (from_dblock(cmd->discard_nr_blocks) == 0)
1157 /* nothing to do */
1158 return 0;
1159
1160 if (cmd->clean_when_opened) {
1161 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, &cmd->discard_root);
1162 if (r)
1163 return r;
1164
1165 r = dm_bitset_cursor_begin(&cmd->discard_info, cmd->discard_root,
1166 from_dblock(cmd->discard_nr_blocks), &c);
1167 if (r)
1168 return r;
1169
1170 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
1171 r = fn(context, cmd->discard_block_size, to_dblock(b),
1172 dm_bitset_cursor_get_value(&c));
1173 if (r)
1174 break;
1175 }
1176
1177 dm_bitset_cursor_end(&c);
1178
1179 } else {
1180 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
1181 r = fn(context, cmd->discard_block_size, to_dblock(b), false);
1182 if (r)
1183 return r;
1184 }
1185 }
1186
1187 return r;
1188}
1189
1190int dm_cache_load_discards(struct dm_cache_metadata *cmd,
1191 load_discard_fn fn, void *context)
1192{
1193 int r;
1194
1195 READ_LOCK(cmd);
1196 r = __load_discards(cmd, fn, context);
1197 READ_UNLOCK(cmd);
1198
1199 return r;
1200}
1201
1202int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result)
1203{
1204 READ_LOCK(cmd);
1205 *result = cmd->cache_blocks;
1206 READ_UNLOCK(cmd);
1207
1208 return 0;
1209}
1210
1211static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1212{
1213 int r;
1214 __le64 value = pack_value(0, 0);
1215
1216 __dm_bless_for_disk(&value);
1217 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1218 &value, &cmd->root);
1219 if (r)
1220 return r;
1221
1222 cmd->changed = true;
1223 return 0;
1224}
1225
1226int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1227{
1228 int r;
1229
1230 WRITE_LOCK(cmd);
1231 r = __remove(cmd, cblock);
1232 WRITE_UNLOCK(cmd);
1233
1234 return r;
1235}
1236
1237static int __insert(struct dm_cache_metadata *cmd,
1238 dm_cblock_t cblock, dm_oblock_t oblock)
1239{
1240 int r;
1241 __le64 value = pack_value(oblock, M_VALID);
1242 __dm_bless_for_disk(&value);
1243
1244 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1245 &value, &cmd->root);
1246 if (r)
1247 return r;
1248
1249 cmd->changed = true;
1250 return 0;
1251}
1252
1253int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
1254 dm_cblock_t cblock, dm_oblock_t oblock)
1255{
1256 int r;
1257
1258 WRITE_LOCK(cmd);
1259 r = __insert(cmd, cblock, oblock);
1260 WRITE_UNLOCK(cmd);
1261
1262 return r;
1263}
1264
1265struct thunk {
1266 load_mapping_fn fn;
1267 void *context;
1268
1269 struct dm_cache_metadata *cmd;
1270 bool respect_dirty_flags;
1271 bool hints_valid;
1272};
1273
1274static bool policy_unchanged(struct dm_cache_metadata *cmd,
1275 struct dm_cache_policy *policy)
1276{
1277 const char *policy_name = dm_cache_policy_get_name(policy);
1278 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1279 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
1280
1281 /*
1282 * Ensure policy names match.
1283 */
1284 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
1285 return false;
1286
1287 /*
1288 * Ensure policy major versions match.
1289 */
1290 if (cmd->policy_version[0] != policy_version[0])
1291 return false;
1292
1293 /*
1294 * Ensure policy hint sizes match.
1295 */
1296 if (cmd->policy_hint_size != policy_hint_size)
1297 return false;
1298
1299 return true;
1300}
1301
1302static bool hints_array_initialized(struct dm_cache_metadata *cmd)
1303{
1304 return cmd->hint_root && cmd->policy_hint_size;
1305}
1306
1307static bool hints_array_available(struct dm_cache_metadata *cmd,
1308 struct dm_cache_policy *policy)
1309{
1310 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
1311 hints_array_initialized(cmd);
1312}
1313
1314static int __load_mapping_v1(struct dm_cache_metadata *cmd,
1315 uint64_t cb, bool hints_valid,
1316 struct dm_array_cursor *mapping_cursor,
1317 struct dm_array_cursor *hint_cursor,
1318 load_mapping_fn fn, void *context)
1319{
1320 int r = 0;
1321
1322 __le64 mapping;
1323 __le32 hint = 0;
1324
1325 __le64 *mapping_value_le;
1326 __le32 *hint_value_le;
1327
1328 dm_oblock_t oblock;
1329 unsigned flags;
1330 bool dirty = true;
1331
1332 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1333 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1334 unpack_value(mapping, &oblock, &flags);
1335
1336 if (flags & M_VALID) {
1337 if (hints_valid) {
1338 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1339 memcpy(&hint, hint_value_le, sizeof(hint));
1340 }
1341 if (cmd->clean_when_opened)
1342 dirty = flags & M_DIRTY;
1343
1344 r = fn(context, oblock, to_cblock(cb), dirty,
1345 le32_to_cpu(hint), hints_valid);
1346 if (r) {
1347 DMERR("policy couldn't load cache block %llu",
1348 (unsigned long long) from_cblock(to_cblock(cb)));
1349 }
1350 }
1351
1352 return r;
1353}
1354
1355static int __load_mapping_v2(struct dm_cache_metadata *cmd,
1356 uint64_t cb, bool hints_valid,
1357 struct dm_array_cursor *mapping_cursor,
1358 struct dm_array_cursor *hint_cursor,
1359 struct dm_bitset_cursor *dirty_cursor,
1360 load_mapping_fn fn, void *context)
1361{
1362 int r = 0;
1363
1364 __le64 mapping;
1365 __le32 hint = 0;
1366
1367 __le64 *mapping_value_le;
1368 __le32 *hint_value_le;
1369
1370 dm_oblock_t oblock;
1371 unsigned flags;
1372 bool dirty = true;
1373
1374 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1375 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1376 unpack_value(mapping, &oblock, &flags);
1377
1378 if (flags & M_VALID) {
1379 if (hints_valid) {
1380 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1381 memcpy(&hint, hint_value_le, sizeof(hint));
1382 }
1383 if (cmd->clean_when_opened)
1384 dirty = dm_bitset_cursor_get_value(dirty_cursor);
1385
1386 r = fn(context, oblock, to_cblock(cb), dirty,
1387 le32_to_cpu(hint), hints_valid);
1388 if (r) {
1389 DMERR("policy couldn't load cache block %llu",
1390 (unsigned long long) from_cblock(to_cblock(cb)));
1391 }
1392 }
1393
1394 return r;
1395}
1396
1397static int __load_mappings(struct dm_cache_metadata *cmd,
1398 struct dm_cache_policy *policy,
1399 load_mapping_fn fn, void *context)
1400{
1401 int r;
1402 uint64_t cb;
1403
1404 bool hints_valid = hints_array_available(cmd, policy);
1405
1406 if (from_cblock(cmd->cache_blocks) == 0)
1407 /* Nothing to do */
1408 return 0;
1409
1410 r = dm_array_cursor_begin(&cmd->info, cmd->root, &cmd->mapping_cursor);
1411 if (r)
1412 return r;
1413
1414 if (hints_valid) {
1415 r = dm_array_cursor_begin(&cmd->hint_info, cmd->hint_root, &cmd->hint_cursor);
1416 if (r) {
1417 dm_array_cursor_end(&cmd->mapping_cursor);
1418 return r;
1419 }
1420 }
1421
1422 if (separate_dirty_bits(cmd)) {
1423 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
1424 from_cblock(cmd->cache_blocks),
1425 &cmd->dirty_cursor);
1426 if (r) {
1427 dm_array_cursor_end(&cmd->hint_cursor);
1428 dm_array_cursor_end(&cmd->mapping_cursor);
1429 return r;
1430 }
1431 }
1432
1433 for (cb = 0; ; cb++) {
1434 if (separate_dirty_bits(cmd))
1435 r = __load_mapping_v2(cmd, cb, hints_valid,
1436 &cmd->mapping_cursor,
1437 &cmd->hint_cursor,
1438 &cmd->dirty_cursor,
1439 fn, context);
1440 else
1441 r = __load_mapping_v1(cmd, cb, hints_valid,
1442 &cmd->mapping_cursor, &cmd->hint_cursor,
1443 fn, context);
1444 if (r)
1445 goto out;
1446
1447 /*
1448 * We need to break out before we move the cursors.
1449 */
1450 if (cb >= (from_cblock(cmd->cache_blocks) - 1))
1451 break;
1452
1453 r = dm_array_cursor_next(&cmd->mapping_cursor);
1454 if (r) {
1455 DMERR("dm_array_cursor_next for mapping failed");
1456 goto out;
1457 }
1458
1459 if (hints_valid) {
1460 r = dm_array_cursor_next(&cmd->hint_cursor);
1461 if (r) {
1462 dm_array_cursor_end(&cmd->hint_cursor);
1463 hints_valid = false;
1464 }
1465 }
1466
1467 if (separate_dirty_bits(cmd)) {
1468 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
1469 if (r) {
1470 DMERR("dm_bitset_cursor_next for dirty failed");
1471 goto out;
1472 }
1473 }
1474 }
1475out:
1476 dm_array_cursor_end(&cmd->mapping_cursor);
1477 if (hints_valid)
1478 dm_array_cursor_end(&cmd->hint_cursor);
1479
1480 if (separate_dirty_bits(cmd))
1481 dm_bitset_cursor_end(&cmd->dirty_cursor);
1482
1483 return r;
1484}
1485
1486int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
1487 struct dm_cache_policy *policy,
1488 load_mapping_fn fn, void *context)
1489{
1490 int r;
1491
1492 READ_LOCK(cmd);
1493 r = __load_mappings(cmd, policy, fn, context);
1494 READ_UNLOCK(cmd);
1495
1496 return r;
1497}
1498
1499static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
1500{
1501 int r = 0;
1502 __le64 value;
1503 dm_oblock_t oblock;
1504 unsigned flags;
1505
1506 memcpy(&value, leaf, sizeof(value));
1507 unpack_value(value, &oblock, &flags);
1508
1509 return r;
1510}
1511
1512static int __dump_mappings(struct dm_cache_metadata *cmd)
1513{
1514 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
1515}
1516
1517void dm_cache_dump(struct dm_cache_metadata *cmd)
1518{
1519 READ_LOCK_VOID(cmd);
1520 __dump_mappings(cmd);
1521 READ_UNLOCK(cmd);
1522}
1523
1524int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1525{
1526 int r;
1527
1528 READ_LOCK(cmd);
1529 r = cmd->changed;
1530 READ_UNLOCK(cmd);
1531
1532 return r;
1533}
1534
1535static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1536{
1537 int r;
1538 unsigned flags;
1539 dm_oblock_t oblock;
1540 __le64 value;
1541
1542 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1543 if (r)
1544 return r;
1545
1546 unpack_value(value, &oblock, &flags);
1547
1548 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1549 /* nothing to be done */
1550 return 0;
1551
1552 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
1553 __dm_bless_for_disk(&value);
1554
1555 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1556 &value, &cmd->root);
1557 if (r)
1558 return r;
1559
1560 cmd->changed = true;
1561 return 0;
1562
1563}
1564
1565static int __set_dirty_bits_v1(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1566{
1567 int r;
1568 unsigned i;
1569 for (i = 0; i < nr_bits; i++) {
1570 r = __dirty(cmd, to_cblock(i), test_bit(i, bits));
1571 if (r)
1572 return r;
1573 }
1574
1575 return 0;
1576}
1577
1578static int is_dirty_callback(uint32_t index, bool *value, void *context)
1579{
1580 unsigned long *bits = context;
1581 *value = test_bit(index, bits);
1582 return 0;
1583}
1584
1585static int __set_dirty_bits_v2(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1586{
1587 int r = 0;
1588
1589 /* nr_bits is really just a sanity check */
1590 if (nr_bits != from_cblock(cmd->cache_blocks)) {
1591 DMERR("dirty bitset is wrong size");
1592 return -EINVAL;
1593 }
1594
1595 r = dm_bitset_del(&cmd->dirty_info, cmd->dirty_root);
1596 if (r)
1597 return r;
1598
1599 cmd->changed = true;
1600 return dm_bitset_new(&cmd->dirty_info, &cmd->dirty_root, nr_bits, is_dirty_callback, bits);
1601}
1602
1603int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd,
1604 unsigned nr_bits,
1605 unsigned long *bits)
1606{
1607 int r;
1608
1609 WRITE_LOCK(cmd);
1610 if (separate_dirty_bits(cmd))
1611 r = __set_dirty_bits_v2(cmd, nr_bits, bits);
1612 else
1613 r = __set_dirty_bits_v1(cmd, nr_bits, bits);
1614 WRITE_UNLOCK(cmd);
1615
1616 return r;
1617}
1618
1619void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1620 struct dm_cache_statistics *stats)
1621{
1622 READ_LOCK_VOID(cmd);
1623 *stats = cmd->stats;
1624 READ_UNLOCK(cmd);
1625}
1626
1627void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1628 struct dm_cache_statistics *stats)
1629{
1630 WRITE_LOCK_VOID(cmd);
1631 cmd->stats = *stats;
1632 WRITE_UNLOCK(cmd);
1633}
1634
1635int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1636{
1637 int r = -EINVAL;
1638 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1639 clear_clean_shutdown);
1640
1641 WRITE_LOCK(cmd);
1642 if (cmd->fail_io)
1643 goto out;
1644
1645 r = __commit_transaction(cmd, mutator);
1646 if (r)
1647 goto out;
1648
1649 r = __begin_transaction(cmd);
1650out:
1651 WRITE_UNLOCK(cmd);
1652 return r;
1653}
1654
1655int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1656 dm_block_t *result)
1657{
1658 int r = -EINVAL;
1659
1660 READ_LOCK(cmd);
1661 if (!cmd->fail_io)
1662 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1663 READ_UNLOCK(cmd);
1664
1665 return r;
1666}
1667
1668int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1669 dm_block_t *result)
1670{
1671 int r = -EINVAL;
1672
1673 READ_LOCK(cmd);
1674 if (!cmd->fail_io)
1675 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1676 READ_UNLOCK(cmd);
1677
1678 return r;
1679}
1680
1681/*----------------------------------------------------------------*/
1682
1683static int get_hint(uint32_t index, void *value_le, void *context)
1684{
1685 uint32_t value;
1686 struct dm_cache_policy *policy = context;
1687
1688 value = policy_get_hint(policy, to_cblock(index));
1689 *((__le32 *) value_le) = cpu_to_le32(value);
1690
1691 return 0;
1692}
1693
1694/*
1695 * It's quicker to always delete the hint array, and recreate with
1696 * dm_array_new().
1697 */
1698static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1699{
1700 int r;
1701 size_t hint_size;
1702 const char *policy_name = dm_cache_policy_get_name(policy);
1703 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1704
1705 if (!policy_name[0] ||
1706 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1707 return -EINVAL;
1708
1709 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
1710 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
1711
1712 hint_size = dm_cache_policy_get_hint_size(policy);
1713 if (!hint_size)
1714 return 0; /* short-circuit hints initialization */
1715 cmd->policy_hint_size = hint_size;
1716
1717 if (cmd->hint_root) {
1718 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1719 if (r)
1720 return r;
1721 }
1722
1723 return dm_array_new(&cmd->hint_info, &cmd->hint_root,
1724 from_cblock(cmd->cache_blocks),
1725 get_hint, policy);
1726}
1727
1728int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1729{
1730 int r;
1731
1732 WRITE_LOCK(cmd);
1733 r = write_hints(cmd, policy);
1734 WRITE_UNLOCK(cmd);
1735
1736 return r;
1737}
1738
1739int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
1740{
1741 int r;
1742
1743 READ_LOCK(cmd);
1744 r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
1745 READ_UNLOCK(cmd);
1746
1747 return r;
1748}
1749
1750void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
1751{
1752 WRITE_LOCK_VOID(cmd);
1753 dm_bm_set_read_only(cmd->bm);
1754 WRITE_UNLOCK(cmd);
1755}
1756
1757void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
1758{
1759 WRITE_LOCK_VOID(cmd);
1760 dm_bm_set_read_write(cmd->bm);
1761 WRITE_UNLOCK(cmd);
1762}
1763
1764int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
1765{
1766 int r;
1767 struct dm_block *sblock;
1768 struct cache_disk_superblock *disk_super;
1769
1770 WRITE_LOCK(cmd);
1771 set_bit(NEEDS_CHECK, &cmd->flags);
1772
1773 r = superblock_lock(cmd, &sblock);
1774 if (r) {
1775 DMERR("couldn't read superblock");
1776 goto out;
1777 }
1778
1779 disk_super = dm_block_data(sblock);
1780 disk_super->flags = cpu_to_le32(cmd->flags);
1781
1782 dm_bm_unlock(sblock);
1783
1784out:
1785 WRITE_UNLOCK(cmd);
1786 return r;
1787}
1788
1789int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result)
1790{
1791 READ_LOCK(cmd);
1792 *result = !!test_bit(NEEDS_CHECK, &cmd->flags);
1793 READ_UNLOCK(cmd);
1794
1795 return 0;
1796}
1797
1798int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
1799{
1800 int r;
1801
1802 WRITE_LOCK(cmd);
1803 __destroy_persistent_data_objects(cmd);
1804 r = __create_persistent_data_objects(cmd, false);
1805 if (r)
1806 cmd->fail_io = true;
1807 WRITE_UNLOCK(cmd);
1808
1809 return r;
1810}
1811