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staging: rtl8188eu: rename HalSetBrateCfg() - style
[linux/fpc-iii.git] / drivers / md / dm-cache-metadata.c
blob69dddeab124c2e1ac075dc24c14ebe725647e3a3
1 /*
2 * Copyright (C) 2012 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7 #include "dm-cache-metadata.h"
8
9 #include "persistent-data/dm-array.h"
10 #include "persistent-data/dm-bitset.h"
11 #include "persistent-data/dm-space-map.h"
12 #include "persistent-data/dm-space-map-disk.h"
13 #include "persistent-data/dm-transaction-manager.h"
14
15 #include <linux/device-mapper.h>
16 #include <linux/refcount.h>
17
18 /*----------------------------------------------------------------*/
19
20 #define DM_MSG_PREFIX "cache metadata"
21
22 #define CACHE_SUPERBLOCK_MAGIC 06142003
23 #define CACHE_SUPERBLOCK_LOCATION 0
24
25 /*
26 * defines a range of metadata versions that this module can handle.
27 */
28 #define MIN_CACHE_VERSION 1
29 #define MAX_CACHE_VERSION 2
30
31 /*
32 * 3 for btree insert +
33 * 2 for btree lookup used within space map
34 */
35 #define CACHE_MAX_CONCURRENT_LOCKS 5
36 #define SPACE_MAP_ROOT_SIZE 128
37
38 enum superblock_flag_bits {
39 /* for spotting crashes that would invalidate the dirty bitset */
40 CLEAN_SHUTDOWN,
41 /* metadata must be checked using the tools */
42 NEEDS_CHECK,
43 };
44
45 /*
46 * Each mapping from cache block -> origin block carries a set of flags.
47 */
48 enum mapping_bits {
49 /*
50 * A valid mapping. Because we're using an array we clear this
51 * flag for an non existant mapping.
52 */
53 M_VALID = 1,
54
55 /*
56 * The data on the cache is different from that on the origin.
57 * This flag is only used by metadata format 1.
58 */
59 M_DIRTY = 2
60 };
61
62 struct cache_disk_superblock {
63 __le32 csum;
64 __le32 flags;
65 __le64 blocknr;
66
67 __u8 uuid[16];
68 __le64 magic;
69 __le32 version;
70
71 __u8 policy_name[CACHE_POLICY_NAME_SIZE];
72 __le32 policy_hint_size;
73
74 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
75 __le64 mapping_root;
76 __le64 hint_root;
77
78 __le64 discard_root;
79 __le64 discard_block_size;
80 __le64 discard_nr_blocks;
81
82 __le32 data_block_size;
83 __le32 metadata_block_size;
84 __le32 cache_blocks;
85
86 __le32 compat_flags;
87 __le32 compat_ro_flags;
88 __le32 incompat_flags;
89
90 __le32 read_hits;
91 __le32 read_misses;
92 __le32 write_hits;
93 __le32 write_misses;
94
95 __le32 policy_version[CACHE_POLICY_VERSION_SIZE];
96
97 /*
98 * Metadata format 2 fields.
99 */
100 __le64 dirty_root;
101 } __packed;
102
103 struct dm_cache_metadata {
104 refcount_t ref_count;
105 struct list_head list;
106
107 unsigned version;
108 struct block_device *bdev;
109 struct dm_block_manager *bm;
110 struct dm_space_map *metadata_sm;
111 struct dm_transaction_manager *tm;
112
113 struct dm_array_info info;
114 struct dm_array_info hint_info;
115 struct dm_disk_bitset discard_info;
116
117 struct rw_semaphore root_lock;
118 unsigned long flags;
119 dm_block_t root;
120 dm_block_t hint_root;
121 dm_block_t discard_root;
122
123 sector_t discard_block_size;
124 dm_dblock_t discard_nr_blocks;
125
126 sector_t data_block_size;
127 dm_cblock_t cache_blocks;
128 bool changed:1;
129 bool clean_when_opened:1;
130
131 char policy_name[CACHE_POLICY_NAME_SIZE];
132 unsigned policy_version[CACHE_POLICY_VERSION_SIZE];
133 size_t policy_hint_size;
134 struct dm_cache_statistics stats;
135
136 /*
137 * Reading the space map root can fail, so we read it into this
138 * buffer before the superblock is locked and updated.
139 */
140 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
141
142 /*
143 * Set if a transaction has to be aborted but the attempt to roll
144 * back to the previous (good) transaction failed. The only
145 * metadata operation permissible in this state is the closing of
146 * the device.
147 */
148 bool fail_io:1;
149
150 /*
151 * Metadata format 2 fields.
152 */
153 dm_block_t dirty_root;
154 struct dm_disk_bitset dirty_info;
155
156 /*
157 * These structures are used when loading metadata. They're too
158 * big to put on the stack.
159 */
160 struct dm_array_cursor mapping_cursor;
161 struct dm_array_cursor hint_cursor;
162 struct dm_bitset_cursor dirty_cursor;
163 };
164
165 /*-------------------------------------------------------------------
166 * superblock validator
167 *-----------------------------------------------------------------*/
168
169 #define SUPERBLOCK_CSUM_XOR 9031977
170
171 static void sb_prepare_for_write(struct dm_block_validator *v,
172 struct dm_block *b,
173 size_t sb_block_size)
174 {
175 struct cache_disk_superblock *disk_super = dm_block_data(b);
176
177 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
178 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
179 sb_block_size - sizeof(__le32),
180 SUPERBLOCK_CSUM_XOR));
181 }
182
183 static int check_metadata_version(struct cache_disk_superblock *disk_super)
184 {
185 uint32_t metadata_version = le32_to_cpu(disk_super->version);
186
187 if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) {
188 DMERR("Cache metadata version %u found, but only versions between %u and %u supported.",
189 metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION);
190 return -EINVAL;
191 }
192
193 return 0;
194 }
195
196 static int sb_check(struct dm_block_validator *v,
197 struct dm_block *b,
198 size_t sb_block_size)
199 {
200 struct cache_disk_superblock *disk_super = dm_block_data(b);
201 __le32 csum_le;
202
203 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
204 DMERR("sb_check failed: blocknr %llu: wanted %llu",
205 le64_to_cpu(disk_super->blocknr),
206 (unsigned long long)dm_block_location(b));
207 return -ENOTBLK;
208 }
209
210 if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) {
211 DMERR("sb_check failed: magic %llu: wanted %llu",
212 le64_to_cpu(disk_super->magic),
213 (unsigned long long)CACHE_SUPERBLOCK_MAGIC);
214 return -EILSEQ;
215 }
216
217 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
218 sb_block_size - sizeof(__le32),
219 SUPERBLOCK_CSUM_XOR));
220 if (csum_le != disk_super->csum) {
221 DMERR("sb_check failed: csum %u: wanted %u",
222 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
223 return -EILSEQ;
224 }
225
226 return check_metadata_version(disk_super);
227 }
228
229 static struct dm_block_validator sb_validator = {
230 .name = "superblock",
231 .prepare_for_write = sb_prepare_for_write,
232 .check = sb_check
233 };
234
235 /*----------------------------------------------------------------*/
236
237 static int superblock_read_lock(struct dm_cache_metadata *cmd,
238 struct dm_block **sblock)
239 {
240 return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
241 &sb_validator, sblock);
242 }
243
244 static int superblock_lock_zero(struct dm_cache_metadata *cmd,
245 struct dm_block **sblock)
246 {
247 return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
248 &sb_validator, sblock);
249 }
250
251 static int superblock_lock(struct dm_cache_metadata *cmd,
252 struct dm_block **sblock)
253 {
254 return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
255 &sb_validator, sblock);
256 }
257
258 /*----------------------------------------------------------------*/
259
260 static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
261 {
262 int r;
263 unsigned i;
264 struct dm_block *b;
265 __le64 *data_le, zero = cpu_to_le64(0);
266 unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
267
268 /*
269 * We can't use a validator here - it may be all zeroes.
270 */
271 r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b);
272 if (r)
273 return r;
274
275 data_le = dm_block_data(b);
276 *result = true;
277 for (i = 0; i < sb_block_size; i++) {
278 if (data_le[i] != zero) {
279 *result = false;
280 break;
281 }
282 }
283
284 dm_bm_unlock(b);
285
286 return 0;
287 }
288
289 static void __setup_mapping_info(struct dm_cache_metadata *cmd)
290 {
291 struct dm_btree_value_type vt;
292
293 vt.context = NULL;
294 vt.size = sizeof(__le64);
295 vt.inc = NULL;
296 vt.dec = NULL;
297 vt.equal = NULL;
298 dm_array_info_init(&cmd->info, cmd->tm, &vt);
299
300 if (cmd->policy_hint_size) {
301 vt.size = sizeof(__le32);
302 dm_array_info_init(&cmd->hint_info, cmd->tm, &vt);
303 }
304 }
305
306 static int __save_sm_root(struct dm_cache_metadata *cmd)
307 {
308 int r;
309 size_t metadata_len;
310
311 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
312 if (r < 0)
313 return r;
314
315 return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
316 metadata_len);
317 }
318
319 static void __copy_sm_root(struct dm_cache_metadata *cmd,
320 struct cache_disk_superblock *disk_super)
321 {
322 memcpy(&disk_super->metadata_space_map_root,
323 &cmd->metadata_space_map_root,
324 sizeof(cmd->metadata_space_map_root));
325 }
326
327 static bool separate_dirty_bits(struct dm_cache_metadata *cmd)
328 {
329 return cmd->version >= 2;
330 }
331
332 static int __write_initial_superblock(struct dm_cache_metadata *cmd)
333 {
334 int r;
335 struct dm_block *sblock;
336 struct cache_disk_superblock *disk_super;
337 sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
338
339 /* FIXME: see if we can lose the max sectors limit */
340 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
341 bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
342
343 r = dm_tm_pre_commit(cmd->tm);
344 if (r < 0)
345 return r;
346
347 /*
348 * dm_sm_copy_root() can fail. So we need to do it before we start
349 * updating the superblock.
350 */
351 r = __save_sm_root(cmd);
352 if (r)
353 return r;
354
355 r = superblock_lock_zero(cmd, &sblock);
356 if (r)
357 return r;
358
359 disk_super = dm_block_data(sblock);
360 disk_super->flags = 0;
361 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
362 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
363 disk_super->version = cpu_to_le32(cmd->version);
364 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
365 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
366 disk_super->policy_hint_size = cpu_to_le32(0);
367
368 __copy_sm_root(cmd, disk_super);
369
370 disk_super->mapping_root = cpu_to_le64(cmd->root);
371 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
372 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
373 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
374 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
375 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE);
376 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
377 disk_super->cache_blocks = cpu_to_le32(0);
378
379 disk_super->read_hits = cpu_to_le32(0);
380 disk_super->read_misses = cpu_to_le32(0);
381 disk_super->write_hits = cpu_to_le32(0);
382 disk_super->write_misses = cpu_to_le32(0);
383
384 if (separate_dirty_bits(cmd))
385 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
386
387 return dm_tm_commit(cmd->tm, sblock);
388 }
389
390 static int __format_metadata(struct dm_cache_metadata *cmd)
391 {
392 int r;
393
394 r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
395 &cmd->tm, &cmd->metadata_sm);
396 if (r < 0) {
397 DMERR("tm_create_with_sm failed");
398 return r;
399 }
400
401 __setup_mapping_info(cmd);
402
403 r = dm_array_empty(&cmd->info, &cmd->root);
404 if (r < 0)
405 goto bad;
406
407 if (separate_dirty_bits(cmd)) {
408 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info);
409 r = dm_bitset_empty(&cmd->dirty_info, &cmd->dirty_root);
410 if (r < 0)
411 goto bad;
412 }
413
414 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
415 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root);
416 if (r < 0)
417 goto bad;
418
419 cmd->discard_block_size = 0;
420 cmd->discard_nr_blocks = 0;
421
422 r = __write_initial_superblock(cmd);
423 if (r)
424 goto bad;
425
426 cmd->clean_when_opened = true;
427 return 0;
428
429 bad:
430 dm_tm_destroy(cmd->tm);
431 dm_sm_destroy(cmd->metadata_sm);
432
433 return r;
434 }
435
436 static int __check_incompat_features(struct cache_disk_superblock *disk_super,
437 struct dm_cache_metadata *cmd)
438 {
439 uint32_t incompat_flags, features;
440
441 incompat_flags = le32_to_cpu(disk_super->incompat_flags);
442 features = incompat_flags & ~DM_CACHE_FEATURE_INCOMPAT_SUPP;
443 if (features) {
444 DMERR("could not access metadata due to unsupported optional features (%lx).",
445 (unsigned long)features);
446 return -EINVAL;
447 }
448
449 /*
450 * Check for read-only metadata to skip the following RDWR checks.
451 */
452 if (get_disk_ro(cmd->bdev->bd_disk))
453 return 0;
454
455 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP;
456 if (features) {
457 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
458 (unsigned long)features);
459 return -EINVAL;
460 }
461
462 return 0;
463 }
464
465 static int __open_metadata(struct dm_cache_metadata *cmd)
466 {
467 int r;
468 struct dm_block *sblock;
469 struct cache_disk_superblock *disk_super;
470 unsigned long sb_flags;
471
472 r = superblock_read_lock(cmd, &sblock);
473 if (r < 0) {
474 DMERR("couldn't read lock superblock");
475 return r;
476 }
477
478 disk_super = dm_block_data(sblock);
479
480 /* Verify the data block size hasn't changed */
481 if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) {
482 DMERR("changing the data block size (from %u to %llu) is not supported",
483 le32_to_cpu(disk_super->data_block_size),
484 (unsigned long long)cmd->data_block_size);
485 r = -EINVAL;
486 goto bad;
487 }
488
489 r = __check_incompat_features(disk_super, cmd);
490 if (r < 0)
491 goto bad;
492
493 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
494 disk_super->metadata_space_map_root,
495 sizeof(disk_super->metadata_space_map_root),
496 &cmd->tm, &cmd->metadata_sm);
497 if (r < 0) {
498 DMERR("tm_open_with_sm failed");
499 goto bad;
500 }
501
502 __setup_mapping_info(cmd);
503 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info);
504 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
505 sb_flags = le32_to_cpu(disk_super->flags);
506 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
507 dm_bm_unlock(sblock);
508
509 return 0;
510
511 bad:
512 dm_bm_unlock(sblock);
513 return r;
514 }
515
516 static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
517 bool format_device)
518 {
519 int r;
520 bool unformatted = false;
521
522 r = __superblock_all_zeroes(cmd->bm, &unformatted);
523 if (r)
524 return r;
525
526 if (unformatted)
527 return format_device ? __format_metadata(cmd) : -EPERM;
528
529 return __open_metadata(cmd);
530 }
531
532 static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
533 bool may_format_device)
534 {
535 int r;
536 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
537 CACHE_MAX_CONCURRENT_LOCKS);
538 if (IS_ERR(cmd->bm)) {
539 DMERR("could not create block manager");
540 return PTR_ERR(cmd->bm);
541 }
542
543 r = __open_or_format_metadata(cmd, may_format_device);
544 if (r)
545 dm_block_manager_destroy(cmd->bm);
546
547 return r;
548 }
549
550 static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd)
551 {
552 dm_sm_destroy(cmd->metadata_sm);
553 dm_tm_destroy(cmd->tm);
554 dm_block_manager_destroy(cmd->bm);
555 }
556
557 typedef unsigned long (*flags_mutator)(unsigned long);
558
559 static void update_flags(struct cache_disk_superblock *disk_super,
560 flags_mutator mutator)
561 {
562 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
563 disk_super->flags = cpu_to_le32(sb_flags);
564 }
565
566 static unsigned long set_clean_shutdown(unsigned long flags)
567 {
568 set_bit(CLEAN_SHUTDOWN, &flags);
569 return flags;
570 }
571
572 static unsigned long clear_clean_shutdown(unsigned long flags)
573 {
574 clear_bit(CLEAN_SHUTDOWN, &flags);
575 return flags;
576 }
577
578 static void read_superblock_fields(struct dm_cache_metadata *cmd,
579 struct cache_disk_superblock *disk_super)
580 {
581 cmd->version = le32_to_cpu(disk_super->version);
582 cmd->flags = le32_to_cpu(disk_super->flags);
583 cmd->root = le64_to_cpu(disk_super->mapping_root);
584 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
585 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
586 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
587 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
588 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
589 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
590 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
591 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
592 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
593 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
594 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
595
596 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
597 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
598 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
599 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
600
601 if (separate_dirty_bits(cmd))
602 cmd->dirty_root = le64_to_cpu(disk_super->dirty_root);
603
604 cmd->changed = false;
605 }
606
607 /*
608 * The mutator updates the superblock flags.
609 */
610 static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
611 flags_mutator mutator)
612 {
613 int r;
614 struct cache_disk_superblock *disk_super;
615 struct dm_block *sblock;
616
617 r = superblock_lock(cmd, &sblock);
618 if (r)
619 return r;
620
621 disk_super = dm_block_data(sblock);
622 update_flags(disk_super, mutator);
623 read_superblock_fields(cmd, disk_super);
624 dm_bm_unlock(sblock);
625
626 return dm_bm_flush(cmd->bm);
627 }
628
629 static int __begin_transaction(struct dm_cache_metadata *cmd)
630 {
631 int r;
632 struct cache_disk_superblock *disk_super;
633 struct dm_block *sblock;
634
635 /*
636 * We re-read the superblock every time. Shouldn't need to do this
637 * really.
638 */
639 r = superblock_read_lock(cmd, &sblock);
640 if (r)
641 return r;
642
643 disk_super = dm_block_data(sblock);
644 read_superblock_fields(cmd, disk_super);
645 dm_bm_unlock(sblock);
646
647 return 0;
648 }
649
650 static int __commit_transaction(struct dm_cache_metadata *cmd,
651 flags_mutator mutator)
652 {
653 int r;
654 struct cache_disk_superblock *disk_super;
655 struct dm_block *sblock;
656
657 /*
658 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
659 */
660 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
661
662 if (separate_dirty_bits(cmd)) {
663 r = dm_bitset_flush(&cmd->dirty_info, cmd->dirty_root,
664 &cmd->dirty_root);
665 if (r)
666 return r;
667 }
668
669 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
670 &cmd->discard_root);
671 if (r)
672 return r;
673
674 r = dm_tm_pre_commit(cmd->tm);
675 if (r < 0)
676 return r;
677
678 r = __save_sm_root(cmd);
679 if (r)
680 return r;
681
682 r = superblock_lock(cmd, &sblock);
683 if (r)
684 return r;
685
686 disk_super = dm_block_data(sblock);
687
688 disk_super->flags = cpu_to_le32(cmd->flags);
689 if (mutator)
690 update_flags(disk_super, mutator);
691
692 disk_super->mapping_root = cpu_to_le64(cmd->root);
693 if (separate_dirty_bits(cmd))
694 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root);
695 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
696 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
697 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
698 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
699 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
700 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
701 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
702 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
703 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
704 disk_super->policy_hint_size = cpu_to_le32(cmd->policy_hint_size);
705
706 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
707 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
708 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
709 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
710 __copy_sm_root(cmd, disk_super);
711
712 return dm_tm_commit(cmd->tm, sblock);
713 }
714
715 /*----------------------------------------------------------------*/
716
717 /*
718 * The mappings are held in a dm-array that has 64-bit values stored in
719 * little-endian format. The index is the cblock, the high 48bits of the
720 * value are the oblock and the low 16 bit the flags.
721 */
722 #define FLAGS_MASK ((1 << 16) - 1)
723
724 static __le64 pack_value(dm_oblock_t block, unsigned flags)
725 {
726 uint64_t value = from_oblock(block);
727 value <<= 16;
728 value = value | (flags & FLAGS_MASK);
729 return cpu_to_le64(value);
730 }
731
732 static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
733 {
734 uint64_t value = le64_to_cpu(value_le);
735 uint64_t b = value >> 16;
736 *block = to_oblock(b);
737 *flags = value & FLAGS_MASK;
738 }
739
740 /*----------------------------------------------------------------*/
741
742 static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
743 sector_t data_block_size,
744 bool may_format_device,
745 size_t policy_hint_size,
746 unsigned metadata_version)
747 {
748 int r;
749 struct dm_cache_metadata *cmd;
750
751 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
752 if (!cmd) {
753 DMERR("could not allocate metadata struct");
754 return ERR_PTR(-ENOMEM);
755 }
756
757 cmd->version = metadata_version;
758 refcount_set(&cmd->ref_count, 1);
759 init_rwsem(&cmd->root_lock);
760 cmd->bdev = bdev;
761 cmd->data_block_size = data_block_size;
762 cmd->cache_blocks = 0;
763 cmd->policy_hint_size = policy_hint_size;
764 cmd->changed = true;
765 cmd->fail_io = false;
766
767 r = __create_persistent_data_objects(cmd, may_format_device);
768 if (r) {
769 kfree(cmd);
770 return ERR_PTR(r);
771 }
772
773 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
774 if (r < 0) {
775 dm_cache_metadata_close(cmd);
776 return ERR_PTR(r);
777 }
778
779 return cmd;
780 }
781
782 /*
783 * We keep a little list of ref counted metadata objects to prevent two
784 * different target instances creating separate bufio instances. This is
785 * an issue if a table is reloaded before the suspend.
786 */
787 static DEFINE_MUTEX(table_lock);
788 static LIST_HEAD(table);
789
790 static struct dm_cache_metadata *lookup(struct block_device *bdev)
791 {
792 struct dm_cache_metadata *cmd;
793
794 list_for_each_entry(cmd, &table, list)
795 if (cmd->bdev == bdev) {
796 refcount_inc(&cmd->ref_count);
797 return cmd;
798 }
799
800 return NULL;
801 }
802
803 static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev,
804 sector_t data_block_size,
805 bool may_format_device,
806 size_t policy_hint_size,
807 unsigned metadata_version)
808 {
809 struct dm_cache_metadata *cmd, *cmd2;
810
811 mutex_lock(&table_lock);
812 cmd = lookup(bdev);
813 mutex_unlock(&table_lock);
814
815 if (cmd)
816 return cmd;
817
818 cmd = metadata_open(bdev, data_block_size, may_format_device,
819 policy_hint_size, metadata_version);
820 if (!IS_ERR(cmd)) {
821 mutex_lock(&table_lock);
822 cmd2 = lookup(bdev);
823 if (cmd2) {
824 mutex_unlock(&table_lock);
825 __destroy_persistent_data_objects(cmd);
826 kfree(cmd);
827 return cmd2;
828 }
829 list_add(&cmd->list, &table);
830 mutex_unlock(&table_lock);
831 }
832
833 return cmd;
834 }
835
836 static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size)
837 {
838 if (cmd->data_block_size != data_block_size) {
839 DMERR("data_block_size (%llu) different from that in metadata (%llu)",
840 (unsigned long long) data_block_size,
841 (unsigned long long) cmd->data_block_size);
842 return false;
843 }
844
845 return true;
846 }
847
848 struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
849 sector_t data_block_size,
850 bool may_format_device,
851 size_t policy_hint_size,
852 unsigned metadata_version)
853 {
854 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, may_format_device,
855 policy_hint_size, metadata_version);
856
857 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) {
858 dm_cache_metadata_close(cmd);
859 return ERR_PTR(-EINVAL);
860 }
861
862 return cmd;
863 }
864
865 void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
866 {
867 if (refcount_dec_and_test(&cmd->ref_count)) {
868 mutex_lock(&table_lock);
869 list_del(&cmd->list);
870 mutex_unlock(&table_lock);
871
872 if (!cmd->fail_io)
873 __destroy_persistent_data_objects(cmd);
874 kfree(cmd);
875 }
876 }
877
878 /*
879 * Checks that the given cache block is either unmapped or clean.
880 */
881 static int block_clean_combined_dirty(struct dm_cache_metadata *cmd, dm_cblock_t b,
882 bool *result)
883 {
884 int r;
885 __le64 value;
886 dm_oblock_t ob;
887 unsigned flags;
888
889 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
890 if (r)
891 return r;
892
893 unpack_value(value, &ob, &flags);
894 *result = !((flags & M_VALID) && (flags & M_DIRTY));
895
896 return 0;
897 }
898
899 static int blocks_are_clean_combined_dirty(struct dm_cache_metadata *cmd,
900 dm_cblock_t begin, dm_cblock_t end,
901 bool *result)
902 {
903 int r;
904 *result = true;
905
906 while (begin != end) {
907 r = block_clean_combined_dirty(cmd, begin, result);
908 if (r) {
909 DMERR("block_clean_combined_dirty failed");
910 return r;
911 }
912
913 if (!*result) {
914 DMERR("cache block %llu is dirty",
915 (unsigned long long) from_cblock(begin));
916 return 0;
917 }
918
919 begin = to_cblock(from_cblock(begin) + 1);
920 }
921
922 return 0;
923 }
924
925 static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd,
926 dm_cblock_t begin, dm_cblock_t end,
927 bool *result)
928 {
929 int r;
930 bool dirty_flag;
931 *result = true;
932
933 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
934 from_cblock(cmd->cache_blocks), &cmd->dirty_cursor);
935 if (r) {
936 DMERR("%s: dm_bitset_cursor_begin for dirty failed", __func__);
937 return r;
938 }
939
940 r = dm_bitset_cursor_skip(&cmd->dirty_cursor, from_cblock(begin));
941 if (r) {
942 DMERR("%s: dm_bitset_cursor_skip for dirty failed", __func__);
943 dm_bitset_cursor_end(&cmd->dirty_cursor);
944 return r;
945 }
946
947 while (begin != end) {
948 /*
949 * We assume that unmapped blocks have their dirty bit
950 * cleared.
951 */
952 dirty_flag = dm_bitset_cursor_get_value(&cmd->dirty_cursor);
953 if (dirty_flag) {
954 DMERR("%s: cache block %llu is dirty", __func__,
955 (unsigned long long) from_cblock(begin));
956 dm_bitset_cursor_end(&cmd->dirty_cursor);
957 *result = false;
958 return 0;
959 }
960
961 begin = to_cblock(from_cblock(begin) + 1);
962 if (begin == end)
963 break;
964
965 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
966 if (r) {
967 DMERR("%s: dm_bitset_cursor_next for dirty failed", __func__);
968 dm_bitset_cursor_end(&cmd->dirty_cursor);
969 return r;
970 }
971 }
972
973 dm_bitset_cursor_end(&cmd->dirty_cursor);
974
975 return 0;
976 }
977
978 static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
979 dm_cblock_t begin, dm_cblock_t end,
980 bool *result)
981 {
982 if (separate_dirty_bits(cmd))
983 return blocks_are_clean_separate_dirty(cmd, begin, end, result);
984 else
985 return blocks_are_clean_combined_dirty(cmd, begin, end, result);
986 }
987
988 static bool cmd_write_lock(struct dm_cache_metadata *cmd)
989 {
990 down_write(&cmd->root_lock);
991 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
992 up_write(&cmd->root_lock);
993 return false;
994 }
995 return true;
996 }
997
998 #define WRITE_LOCK(cmd) \
999 do { \
1000 if (!cmd_write_lock((cmd))) \
1001 return -EINVAL; \
1002 } while(0)
1003
1004 #define WRITE_LOCK_VOID(cmd) \
1005 do { \
1006 if (!cmd_write_lock((cmd))) \
1007 return; \
1008 } while(0)
1009
1010 #define WRITE_UNLOCK(cmd) \
1011 up_write(&(cmd)->root_lock)
1012
1013 static bool cmd_read_lock(struct dm_cache_metadata *cmd)
1014 {
1015 down_read(&cmd->root_lock);
1016 if (cmd->fail_io) {
1017 up_read(&cmd->root_lock);
1018 return false;
1019 }
1020 return true;
1021 }
1022
1023 #define READ_LOCK(cmd) \
1024 do { \
1025 if (!cmd_read_lock((cmd))) \
1026 return -EINVAL; \
1027 } while(0)
1028
1029 #define READ_LOCK_VOID(cmd) \
1030 do { \
1031 if (!cmd_read_lock((cmd))) \
1032 return; \
1033 } while(0)
1034
1035 #define READ_UNLOCK(cmd) \
1036 up_read(&(cmd)->root_lock)
1037
1038 int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
1039 {
1040 int r;
1041 bool clean;
1042 __le64 null_mapping = pack_value(0, 0);
1043
1044 WRITE_LOCK(cmd);
1045 __dm_bless_for_disk(&null_mapping);
1046
1047 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
1048 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
1049 if (r) {
1050 __dm_unbless_for_disk(&null_mapping);
1051 goto out;
1052 }
1053
1054 if (!clean) {
1055 DMERR("unable to shrink cache due to dirty blocks");
1056 r = -EINVAL;
1057 __dm_unbless_for_disk(&null_mapping);
1058 goto out;
1059 }
1060 }
1061
1062 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
1063 from_cblock(new_cache_size),
1064 &null_mapping, &cmd->root);
1065 if (r)
1066 goto out;
1067
1068 if (separate_dirty_bits(cmd)) {
1069 r = dm_bitset_resize(&cmd->dirty_info, cmd->dirty_root,
1070 from_cblock(cmd->cache_blocks), from_cblock(new_cache_size),
1071 false, &cmd->dirty_root);
1072 if (r)
1073 goto out;
1074 }
1075
1076 cmd->cache_blocks = new_cache_size;
1077 cmd->changed = true;
1078
1079 out:
1080 WRITE_UNLOCK(cmd);
1081
1082 return r;
1083 }
1084
1085 int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
1086 sector_t discard_block_size,
1087 dm_dblock_t new_nr_entries)
1088 {
1089 int r;
1090
1091 WRITE_LOCK(cmd);
1092 r = dm_bitset_resize(&cmd->discard_info,
1093 cmd->discard_root,
1094 from_dblock(cmd->discard_nr_blocks),
1095 from_dblock(new_nr_entries),
1096 false, &cmd->discard_root);
1097 if (!r) {
1098 cmd->discard_block_size = discard_block_size;
1099 cmd->discard_nr_blocks = new_nr_entries;
1100 }
1101
1102 cmd->changed = true;
1103 WRITE_UNLOCK(cmd);
1104
1105 return r;
1106 }
1107
1108 static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1109 {
1110 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
1111 from_dblock(b), &cmd->discard_root);
1112 }
1113
1114 static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
1115 {
1116 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
1117 from_dblock(b), &cmd->discard_root);
1118 }
1119
1120 static int __discard(struct dm_cache_metadata *cmd,
1121 dm_dblock_t dblock, bool discard)
1122 {
1123 int r;
1124
1125 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
1126 if (r)
1127 return r;
1128
1129 cmd->changed = true;
1130 return 0;
1131 }
1132
1133 int dm_cache_set_discard(struct dm_cache_metadata *cmd,
1134 dm_dblock_t dblock, bool discard)
1135 {
1136 int r;
1137
1138 WRITE_LOCK(cmd);
1139 r = __discard(cmd, dblock, discard);
1140 WRITE_UNLOCK(cmd);
1141
1142 return r;
1143 }
1144
1145 static int __load_discards(struct dm_cache_metadata *cmd,
1146 load_discard_fn fn, void *context)
1147 {
1148 int r = 0;
1149 uint32_t b;
1150 struct dm_bitset_cursor c;
1151
1152 if (from_dblock(cmd->discard_nr_blocks) == 0)
1153 /* nothing to do */
1154 return 0;
1155
1156 if (cmd->clean_when_opened) {
1157 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, &cmd->discard_root);
1158 if (r)
1159 return r;
1160
1161 r = dm_bitset_cursor_begin(&cmd->discard_info, cmd->discard_root,
1162 from_dblock(cmd->discard_nr_blocks), &c);
1163 if (r)
1164 return r;
1165
1166 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
1167 r = fn(context, cmd->discard_block_size, to_dblock(b),
1168 dm_bitset_cursor_get_value(&c));
1169 if (r)
1170 break;
1171 }
1172
1173 dm_bitset_cursor_end(&c);
1174
1175 } else {
1176 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
1177 r = fn(context, cmd->discard_block_size, to_dblock(b), false);
1178 if (r)
1179 return r;
1180 }
1181 }
1182
1183 return r;
1184 }
1185
1186 int dm_cache_load_discards(struct dm_cache_metadata *cmd,
1187 load_discard_fn fn, void *context)
1188 {
1189 int r;
1190
1191 READ_LOCK(cmd);
1192 r = __load_discards(cmd, fn, context);
1193 READ_UNLOCK(cmd);
1194
1195 return r;
1196 }
1197
1198 int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result)
1199 {
1200 READ_LOCK(cmd);
1201 *result = cmd->cache_blocks;
1202 READ_UNLOCK(cmd);
1203
1204 return 0;
1205 }
1206
1207 static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1208 {
1209 int r;
1210 __le64 value = pack_value(0, 0);
1211
1212 __dm_bless_for_disk(&value);
1213 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1214 &value, &cmd->root);
1215 if (r)
1216 return r;
1217
1218 cmd->changed = true;
1219 return 0;
1220 }
1221
1222 int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1223 {
1224 int r;
1225
1226 WRITE_LOCK(cmd);
1227 r = __remove(cmd, cblock);
1228 WRITE_UNLOCK(cmd);
1229
1230 return r;
1231 }
1232
1233 static int __insert(struct dm_cache_metadata *cmd,
1234 dm_cblock_t cblock, dm_oblock_t oblock)
1235 {
1236 int r;
1237 __le64 value = pack_value(oblock, M_VALID);
1238 __dm_bless_for_disk(&value);
1239
1240 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1241 &value, &cmd->root);
1242 if (r)
1243 return r;
1244
1245 cmd->changed = true;
1246 return 0;
1247 }
1248
1249 int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
1250 dm_cblock_t cblock, dm_oblock_t oblock)
1251 {
1252 int r;
1253
1254 WRITE_LOCK(cmd);
1255 r = __insert(cmd, cblock, oblock);
1256 WRITE_UNLOCK(cmd);
1257
1258 return r;
1259 }
1260
1261 struct thunk {
1262 load_mapping_fn fn;
1263 void *context;
1264
1265 struct dm_cache_metadata *cmd;
1266 bool respect_dirty_flags;
1267 bool hints_valid;
1268 };
1269
1270 static bool policy_unchanged(struct dm_cache_metadata *cmd,
1271 struct dm_cache_policy *policy)
1272 {
1273 const char *policy_name = dm_cache_policy_get_name(policy);
1274 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1275 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
1276
1277 /*
1278 * Ensure policy names match.
1279 */
1280 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
1281 return false;
1282
1283 /*
1284 * Ensure policy major versions match.
1285 */
1286 if (cmd->policy_version[0] != policy_version[0])
1287 return false;
1288
1289 /*
1290 * Ensure policy hint sizes match.
1291 */
1292 if (cmd->policy_hint_size != policy_hint_size)
1293 return false;
1294
1295 return true;
1296 }
1297
1298 static bool hints_array_initialized(struct dm_cache_metadata *cmd)
1299 {
1300 return cmd->hint_root && cmd->policy_hint_size;
1301 }
1302
1303 static bool hints_array_available(struct dm_cache_metadata *cmd,
1304 struct dm_cache_policy *policy)
1305 {
1306 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
1307 hints_array_initialized(cmd);
1308 }
1309
1310 static int __load_mapping_v1(struct dm_cache_metadata *cmd,
1311 uint64_t cb, bool hints_valid,
1312 struct dm_array_cursor *mapping_cursor,
1313 struct dm_array_cursor *hint_cursor,
1314 load_mapping_fn fn, void *context)
1315 {
1316 int r = 0;
1317
1318 __le64 mapping;
1319 __le32 hint = 0;
1320
1321 __le64 *mapping_value_le;
1322 __le32 *hint_value_le;
1323
1324 dm_oblock_t oblock;
1325 unsigned flags;
1326 bool dirty = true;
1327
1328 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1329 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1330 unpack_value(mapping, &oblock, &flags);
1331
1332 if (flags & M_VALID) {
1333 if (hints_valid) {
1334 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1335 memcpy(&hint, hint_value_le, sizeof(hint));
1336 }
1337 if (cmd->clean_when_opened)
1338 dirty = flags & M_DIRTY;
1339
1340 r = fn(context, oblock, to_cblock(cb), dirty,
1341 le32_to_cpu(hint), hints_valid);
1342 if (r) {
1343 DMERR("policy couldn't load cache block %llu",
1344 (unsigned long long) from_cblock(to_cblock(cb)));
1345 }
1346 }
1347
1348 return r;
1349 }
1350
1351 static int __load_mapping_v2(struct dm_cache_metadata *cmd,
1352 uint64_t cb, bool hints_valid,
1353 struct dm_array_cursor *mapping_cursor,
1354 struct dm_array_cursor *hint_cursor,
1355 struct dm_bitset_cursor *dirty_cursor,
1356 load_mapping_fn fn, void *context)
1357 {
1358 int r = 0;
1359
1360 __le64 mapping;
1361 __le32 hint = 0;
1362
1363 __le64 *mapping_value_le;
1364 __le32 *hint_value_le;
1365
1366 dm_oblock_t oblock;
1367 unsigned flags;
1368 bool dirty = true;
1369
1370 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le);
1371 memcpy(&mapping, mapping_value_le, sizeof(mapping));
1372 unpack_value(mapping, &oblock, &flags);
1373
1374 if (flags & M_VALID) {
1375 if (hints_valid) {
1376 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le);
1377 memcpy(&hint, hint_value_le, sizeof(hint));
1378 }
1379 if (cmd->clean_when_opened)
1380 dirty = dm_bitset_cursor_get_value(dirty_cursor);
1381
1382 r = fn(context, oblock, to_cblock(cb), dirty,
1383 le32_to_cpu(hint), hints_valid);
1384 if (r) {
1385 DMERR("policy couldn't load cache block %llu",
1386 (unsigned long long) from_cblock(to_cblock(cb)));
1387 }
1388 }
1389
1390 return r;
1391 }
1392
1393 static int __load_mappings(struct dm_cache_metadata *cmd,
1394 struct dm_cache_policy *policy,
1395 load_mapping_fn fn, void *context)
1396 {
1397 int r;
1398 uint64_t cb;
1399
1400 bool hints_valid = hints_array_available(cmd, policy);
1401
1402 if (from_cblock(cmd->cache_blocks) == 0)
1403 /* Nothing to do */
1404 return 0;
1405
1406 r = dm_array_cursor_begin(&cmd->info, cmd->root, &cmd->mapping_cursor);
1407 if (r)
1408 return r;
1409
1410 if (hints_valid) {
1411 r = dm_array_cursor_begin(&cmd->hint_info, cmd->hint_root, &cmd->hint_cursor);
1412 if (r) {
1413 dm_array_cursor_end(&cmd->mapping_cursor);
1414 return r;
1415 }
1416 }
1417
1418 if (separate_dirty_bits(cmd)) {
1419 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
1420 from_cblock(cmd->cache_blocks),
1421 &cmd->dirty_cursor);
1422 if (r) {
1423 dm_array_cursor_end(&cmd->hint_cursor);
1424 dm_array_cursor_end(&cmd->mapping_cursor);
1425 return r;
1426 }
1427 }
1428
1429 for (cb = 0; ; cb++) {
1430 if (separate_dirty_bits(cmd))
1431 r = __load_mapping_v2(cmd, cb, hints_valid,
1432 &cmd->mapping_cursor,
1433 &cmd->hint_cursor,
1434 &cmd->dirty_cursor,
1435 fn, context);
1436 else
1437 r = __load_mapping_v1(cmd, cb, hints_valid,
1438 &cmd->mapping_cursor, &cmd->hint_cursor,
1439 fn, context);
1440 if (r)
1441 goto out;
1442
1443 /*
1444 * We need to break out before we move the cursors.
1445 */
1446 if (cb >= (from_cblock(cmd->cache_blocks) - 1))
1447 break;
1448
1449 r = dm_array_cursor_next(&cmd->mapping_cursor);
1450 if (r) {
1451 DMERR("dm_array_cursor_next for mapping failed");
1452 goto out;
1453 }
1454
1455 if (hints_valid) {
1456 r = dm_array_cursor_next(&cmd->hint_cursor);
1457 if (r) {
1458 DMERR("dm_array_cursor_next for hint failed");
1459 goto out;
1460 }
1461 }
1462
1463 if (separate_dirty_bits(cmd)) {
1464 r = dm_bitset_cursor_next(&cmd->dirty_cursor);
1465 if (r) {
1466 DMERR("dm_bitset_cursor_next for dirty failed");
1467 goto out;
1468 }
1469 }
1470 }
1471 out:
1472 dm_array_cursor_end(&cmd->mapping_cursor);
1473 if (hints_valid)
1474 dm_array_cursor_end(&cmd->hint_cursor);
1475
1476 if (separate_dirty_bits(cmd))
1477 dm_bitset_cursor_end(&cmd->dirty_cursor);
1478
1479 return r;
1480 }
1481
1482 int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
1483 struct dm_cache_policy *policy,
1484 load_mapping_fn fn, void *context)
1485 {
1486 int r;
1487
1488 READ_LOCK(cmd);
1489 r = __load_mappings(cmd, policy, fn, context);
1490 READ_UNLOCK(cmd);
1491
1492 return r;
1493 }
1494
1495 static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
1496 {
1497 int r = 0;
1498 __le64 value;
1499 dm_oblock_t oblock;
1500 unsigned flags;
1501
1502 memcpy(&value, leaf, sizeof(value));
1503 unpack_value(value, &oblock, &flags);
1504
1505 return r;
1506 }
1507
1508 static int __dump_mappings(struct dm_cache_metadata *cmd)
1509 {
1510 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
1511 }
1512
1513 void dm_cache_dump(struct dm_cache_metadata *cmd)
1514 {
1515 READ_LOCK_VOID(cmd);
1516 __dump_mappings(cmd);
1517 READ_UNLOCK(cmd);
1518 }
1519
1520 int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1521 {
1522 int r;
1523
1524 READ_LOCK(cmd);
1525 r = cmd->changed;
1526 READ_UNLOCK(cmd);
1527
1528 return r;
1529 }
1530
1531 static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1532 {
1533 int r;
1534 unsigned flags;
1535 dm_oblock_t oblock;
1536 __le64 value;
1537
1538 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1539 if (r)
1540 return r;
1541
1542 unpack_value(value, &oblock, &flags);
1543
1544 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1545 /* nothing to be done */
1546 return 0;
1547
1548 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
1549 __dm_bless_for_disk(&value);
1550
1551 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1552 &value, &cmd->root);
1553 if (r)
1554 return r;
1555
1556 cmd->changed = true;
1557 return 0;
1558
1559 }
1560
1561 static int __set_dirty_bits_v1(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1562 {
1563 int r;
1564 unsigned i;
1565 for (i = 0; i < nr_bits; i++) {
1566 r = __dirty(cmd, to_cblock(i), test_bit(i, bits));
1567 if (r)
1568 return r;
1569 }
1570
1571 return 0;
1572 }
1573
1574 static int is_dirty_callback(uint32_t index, bool *value, void *context)
1575 {
1576 unsigned long *bits = context;
1577 *value = test_bit(index, bits);
1578 return 0;
1579 }
1580
1581 static int __set_dirty_bits_v2(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits)
1582 {
1583 int r = 0;
1584
1585 /* nr_bits is really just a sanity check */
1586 if (nr_bits != from_cblock(cmd->cache_blocks)) {
1587 DMERR("dirty bitset is wrong size");
1588 return -EINVAL;
1589 }
1590
1591 r = dm_bitset_del(&cmd->dirty_info, cmd->dirty_root);
1592 if (r)
1593 return r;
1594
1595 cmd->changed = true;
1596 return dm_bitset_new(&cmd->dirty_info, &cmd->dirty_root, nr_bits, is_dirty_callback, bits);
1597 }
1598
1599 int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd,
1600 unsigned nr_bits,
1601 unsigned long *bits)
1602 {
1603 int r;
1604
1605 WRITE_LOCK(cmd);
1606 if (separate_dirty_bits(cmd))
1607 r = __set_dirty_bits_v2(cmd, nr_bits, bits);
1608 else
1609 r = __set_dirty_bits_v1(cmd, nr_bits, bits);
1610 WRITE_UNLOCK(cmd);
1611
1612 return r;
1613 }
1614
1615 void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1616 struct dm_cache_statistics *stats)
1617 {
1618 READ_LOCK_VOID(cmd);
1619 *stats = cmd->stats;
1620 READ_UNLOCK(cmd);
1621 }
1622
1623 void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1624 struct dm_cache_statistics *stats)
1625 {
1626 WRITE_LOCK_VOID(cmd);
1627 cmd->stats = *stats;
1628 WRITE_UNLOCK(cmd);
1629 }
1630
1631 int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1632 {
1633 int r = -EINVAL;
1634 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1635 clear_clean_shutdown);
1636
1637 WRITE_LOCK(cmd);
1638 if (cmd->fail_io)
1639 goto out;
1640
1641 r = __commit_transaction(cmd, mutator);
1642 if (r)
1643 goto out;
1644
1645 r = __begin_transaction(cmd);
1646 out:
1647 WRITE_UNLOCK(cmd);
1648 return r;
1649 }
1650
1651 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1652 dm_block_t *result)
1653 {
1654 int r = -EINVAL;
1655
1656 READ_LOCK(cmd);
1657 if (!cmd->fail_io)
1658 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1659 READ_UNLOCK(cmd);
1660
1661 return r;
1662 }
1663
1664 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1665 dm_block_t *result)
1666 {
1667 int r = -EINVAL;
1668
1669 READ_LOCK(cmd);
1670 if (!cmd->fail_io)
1671 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1672 READ_UNLOCK(cmd);
1673
1674 return r;
1675 }
1676
1677 /*----------------------------------------------------------------*/
1678
1679 static int get_hint(uint32_t index, void *value_le, void *context)
1680 {
1681 uint32_t value;
1682 struct dm_cache_policy *policy = context;
1683
1684 value = policy_get_hint(policy, to_cblock(index));
1685 *((__le32 *) value_le) = cpu_to_le32(value);
1686
1687 return 0;
1688 }
1689
1690 /*
1691 * It's quicker to always delete the hint array, and recreate with
1692 * dm_array_new().
1693 */
1694 static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1695 {
1696 int r;
1697 size_t hint_size;
1698 const char *policy_name = dm_cache_policy_get_name(policy);
1699 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1700
1701 if (!policy_name[0] ||
1702 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1703 return -EINVAL;
1704
1705 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
1706 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
1707
1708 hint_size = dm_cache_policy_get_hint_size(policy);
1709 if (!hint_size)
1710 return 0; /* short-circuit hints initialization */
1711 cmd->policy_hint_size = hint_size;
1712
1713 if (cmd->hint_root) {
1714 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1715 if (r)
1716 return r;
1717 }
1718
1719 return dm_array_new(&cmd->hint_info, &cmd->hint_root,
1720 from_cblock(cmd->cache_blocks),
1721 get_hint, policy);
1722 }
1723
1724 int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1725 {
1726 int r;
1727
1728 WRITE_LOCK(cmd);
1729 r = write_hints(cmd, policy);
1730 WRITE_UNLOCK(cmd);
1731
1732 return r;
1733 }
1734
1735 int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
1736 {
1737 int r;
1738
1739 READ_LOCK(cmd);
1740 r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
1741 READ_UNLOCK(cmd);
1742
1743 return r;
1744 }
1745
1746 void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
1747 {
1748 WRITE_LOCK_VOID(cmd);
1749 dm_bm_set_read_only(cmd->bm);
1750 WRITE_UNLOCK(cmd);
1751 }
1752
1753 void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
1754 {
1755 WRITE_LOCK_VOID(cmd);
1756 dm_bm_set_read_write(cmd->bm);
1757 WRITE_UNLOCK(cmd);
1758 }
1759
1760 int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
1761 {
1762 int r;
1763 struct dm_block *sblock;
1764 struct cache_disk_superblock *disk_super;
1765
1766 WRITE_LOCK(cmd);
1767 set_bit(NEEDS_CHECK, &cmd->flags);
1768
1769 r = superblock_lock(cmd, &sblock);
1770 if (r) {
1771 DMERR("couldn't read superblock");
1772 goto out;
1773 }
1774
1775 disk_super = dm_block_data(sblock);
1776 disk_super->flags = cpu_to_le32(cmd->flags);
1777
1778 dm_bm_unlock(sblock);
1779
1780 out:
1781 WRITE_UNLOCK(cmd);
1782 return r;
1783 }
1784
1785 int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result)
1786 {
1787 READ_LOCK(cmd);
1788 *result = !!test_bit(NEEDS_CHECK, &cmd->flags);
1789 READ_UNLOCK(cmd);
1790
1791 return 0;
1792 }
1793
1794 int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
1795 {
1796 int r;
1797
1798 WRITE_LOCK(cmd);
1799 __destroy_persistent_data_objects(cmd);
1800 r = __create_persistent_data_objects(cmd, false);
1801 if (r)
1802 cmd->fail_io = true;
1803 WRITE_UNLOCK(cmd);
1804
1805 return r;
1806 }
Linux with added FPC-III support