blob: 20cc36b01b77895625adbe82a14923148d688edb [file] [log] [blame]
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001/*
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
17/*----------------------------------------------------------------*/
18
19#define DM_MSG_PREFIX "cache metadata"
20
21#define CACHE_SUPERBLOCK_MAGIC 06142003
22#define CACHE_SUPERBLOCK_LOCATION 0
Joe Thornber53d49812013-10-16 10:59:26 +010023
24/*
25 * defines a range of metadata versions that this module can handle.
26 */
27#define MIN_CACHE_VERSION 1
28#define MAX_CACHE_VERSION 1
29
Joe Thornberc6b4fcb2013-03-01 22:45:51 +000030#define CACHE_METADATA_CACHE_SIZE 64
31
32/*
33 * 3 for btree insert +
34 * 2 for btree lookup used within space map
35 */
36#define CACHE_MAX_CONCURRENT_LOCKS 5
37#define SPACE_MAP_ROOT_SIZE 128
38
39enum superblock_flag_bits {
40 /* for spotting crashes that would invalidate the dirty bitset */
41 CLEAN_SHUTDOWN,
Joe Thornber028ae9f2015-04-22 16:42:35 -040042 /* metadata must be checked using the tools */
43 NEEDS_CHECK,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +000044};
45
46/*
47 * Each mapping from cache block -> origin block carries a set of flags.
48 */
49enum mapping_bits {
50 /*
51 * A valid mapping. Because we're using an array we clear this
52 * flag for an non existant mapping.
53 */
54 M_VALID = 1,
55
56 /*
57 * The data on the cache is different from that on the origin.
58 */
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;
Mike Snitzer4e7f5062013-03-20 17:21:27 +000094
95 __le32 policy_version[CACHE_POLICY_VERSION_SIZE];
Joe Thornberc6b4fcb2013-03-01 22:45:51 +000096} __packed;
97
98struct dm_cache_metadata {
Joe Thornber9b1cc9f2015-01-23 10:00:07 +000099 atomic_t ref_count;
100 struct list_head list;
101
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000102 struct block_device *bdev;
103 struct dm_block_manager *bm;
104 struct dm_space_map *metadata_sm;
105 struct dm_transaction_manager *tm;
106
107 struct dm_array_info info;
108 struct dm_array_info hint_info;
109 struct dm_disk_bitset discard_info;
110
111 struct rw_semaphore root_lock;
Joe Thornber028ae9f2015-04-22 16:42:35 -0400112 unsigned long flags;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000113 dm_block_t root;
114 dm_block_t hint_root;
115 dm_block_t discard_root;
116
117 sector_t discard_block_size;
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000118 dm_dblock_t discard_nr_blocks;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000119
120 sector_t data_block_size;
121 dm_cblock_t cache_blocks;
122 bool changed:1;
123 bool clean_when_opened:1;
124
125 char policy_name[CACHE_POLICY_NAME_SIZE];
Mike Snitzer4e7f5062013-03-20 17:21:27 +0000126 unsigned policy_version[CACHE_POLICY_VERSION_SIZE];
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000127 size_t policy_hint_size;
128 struct dm_cache_statistics stats;
Joe Thornber5a320832014-03-27 14:13:23 +0000129
130 /*
131 * Reading the space map root can fail, so we read it into this
132 * buffer before the superblock is locked and updated.
133 */
134 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
Joe Thornber028ae9f2015-04-22 16:42:35 -0400135
136 /*
137 * Set if a transaction has to be aborted but the attempt to roll
138 * back to the previous (good) transaction failed. The only
139 * metadata operation permissible in this state is the closing of
140 * the device.
141 */
142 bool fail_io:1;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000143};
144
145/*-------------------------------------------------------------------
146 * superblock validator
147 *-----------------------------------------------------------------*/
148
149#define SUPERBLOCK_CSUM_XOR 9031977
150
151static void sb_prepare_for_write(struct dm_block_validator *v,
152 struct dm_block *b,
153 size_t sb_block_size)
154{
155 struct cache_disk_superblock *disk_super = dm_block_data(b);
156
157 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
158 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
159 sb_block_size - sizeof(__le32),
160 SUPERBLOCK_CSUM_XOR));
161}
162
Joe Thornber53d49812013-10-16 10:59:26 +0100163static int check_metadata_version(struct cache_disk_superblock *disk_super)
164{
165 uint32_t metadata_version = le32_to_cpu(disk_super->version);
166 if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) {
167 DMERR("Cache metadata version %u found, but only versions between %u and %u supported.",
168 metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION);
169 return -EINVAL;
170 }
171
172 return 0;
173}
174
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000175static int sb_check(struct dm_block_validator *v,
176 struct dm_block *b,
177 size_t sb_block_size)
178{
179 struct cache_disk_superblock *disk_super = dm_block_data(b);
180 __le32 csum_le;
181
182 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
183 DMERR("sb_check failed: blocknr %llu: wanted %llu",
184 le64_to_cpu(disk_super->blocknr),
185 (unsigned long long)dm_block_location(b));
186 return -ENOTBLK;
187 }
188
189 if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) {
190 DMERR("sb_check failed: magic %llu: wanted %llu",
191 le64_to_cpu(disk_super->magic),
192 (unsigned long long)CACHE_SUPERBLOCK_MAGIC);
193 return -EILSEQ;
194 }
195
196 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
197 sb_block_size - sizeof(__le32),
198 SUPERBLOCK_CSUM_XOR));
199 if (csum_le != disk_super->csum) {
200 DMERR("sb_check failed: csum %u: wanted %u",
201 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
202 return -EILSEQ;
203 }
204
Joe Thornber53d49812013-10-16 10:59:26 +0100205 return check_metadata_version(disk_super);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000206}
207
208static struct dm_block_validator sb_validator = {
209 .name = "superblock",
210 .prepare_for_write = sb_prepare_for_write,
211 .check = sb_check
212};
213
214/*----------------------------------------------------------------*/
215
216static int superblock_read_lock(struct dm_cache_metadata *cmd,
217 struct dm_block **sblock)
218{
219 return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
220 &sb_validator, sblock);
221}
222
223static int superblock_lock_zero(struct dm_cache_metadata *cmd,
224 struct dm_block **sblock)
225{
226 return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
227 &sb_validator, sblock);
228}
229
230static int superblock_lock(struct dm_cache_metadata *cmd,
231 struct dm_block **sblock)
232{
233 return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
234 &sb_validator, sblock);
235}
236
237/*----------------------------------------------------------------*/
238
Joe Thornberdd8b0c22013-10-24 14:10:28 -0400239static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000240{
241 int r;
242 unsigned i;
243 struct dm_block *b;
244 __le64 *data_le, zero = cpu_to_le64(0);
245 unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
246
247 /*
248 * We can't use a validator here - it may be all zeroes.
249 */
250 r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b);
251 if (r)
252 return r;
253
254 data_le = dm_block_data(b);
Joe Thornberdd8b0c22013-10-24 14:10:28 -0400255 *result = true;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000256 for (i = 0; i < sb_block_size; i++) {
257 if (data_le[i] != zero) {
Joe Thornberdd8b0c22013-10-24 14:10:28 -0400258 *result = false;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000259 break;
260 }
261 }
262
263 return dm_bm_unlock(b);
264}
265
266static void __setup_mapping_info(struct dm_cache_metadata *cmd)
267{
268 struct dm_btree_value_type vt;
269
270 vt.context = NULL;
271 vt.size = sizeof(__le64);
272 vt.inc = NULL;
273 vt.dec = NULL;
274 vt.equal = NULL;
275 dm_array_info_init(&cmd->info, cmd->tm, &vt);
276
277 if (cmd->policy_hint_size) {
278 vt.size = sizeof(__le32);
279 dm_array_info_init(&cmd->hint_info, cmd->tm, &vt);
280 }
281}
282
Joe Thornber5a320832014-03-27 14:13:23 +0000283static int __save_sm_root(struct dm_cache_metadata *cmd)
284{
285 int r;
286 size_t metadata_len;
287
288 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
289 if (r < 0)
290 return r;
291
292 return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
293 metadata_len);
294}
295
296static void __copy_sm_root(struct dm_cache_metadata *cmd,
297 struct cache_disk_superblock *disk_super)
298{
299 memcpy(&disk_super->metadata_space_map_root,
300 &cmd->metadata_space_map_root,
301 sizeof(cmd->metadata_space_map_root));
302}
303
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000304static int __write_initial_superblock(struct dm_cache_metadata *cmd)
305{
306 int r;
307 struct dm_block *sblock;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000308 struct cache_disk_superblock *disk_super;
309 sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
310
311 /* FIXME: see if we can lose the max sectors limit */
312 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
313 bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
314
Joe Thornber5a320832014-03-27 14:13:23 +0000315 r = dm_tm_pre_commit(cmd->tm);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000316 if (r < 0)
317 return r;
318
Joe Thornber5a320832014-03-27 14:13:23 +0000319 /*
320 * dm_sm_copy_root() can fail. So we need to do it before we start
321 * updating the superblock.
322 */
323 r = __save_sm_root(cmd);
324 if (r)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000325 return r;
326
327 r = superblock_lock_zero(cmd, &sblock);
328 if (r)
329 return r;
330
331 disk_super = dm_block_data(sblock);
332 disk_super->flags = 0;
333 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
334 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
Joe Thornber53d49812013-10-16 10:59:26 +0100335 disk_super->version = cpu_to_le32(MAX_CACHE_VERSION);
Mike Snitzer4e7f5062013-03-20 17:21:27 +0000336 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
337 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000338 disk_super->policy_hint_size = 0;
339
Joe Thornber5a320832014-03-27 14:13:23 +0000340 __copy_sm_root(cmd, disk_super);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000341
342 disk_super->mapping_root = cpu_to_le64(cmd->root);
343 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
344 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
345 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000346 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
Mike Snitzer895b47d2014-07-14 15:37:18 -0400347 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000348 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
349 disk_super->cache_blocks = cpu_to_le32(0);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000350
351 disk_super->read_hits = cpu_to_le32(0);
352 disk_super->read_misses = cpu_to_le32(0);
353 disk_super->write_hits = cpu_to_le32(0);
354 disk_super->write_misses = cpu_to_le32(0);
355
356 return dm_tm_commit(cmd->tm, sblock);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000357}
358
359static int __format_metadata(struct dm_cache_metadata *cmd)
360{
361 int r;
362
363 r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
364 &cmd->tm, &cmd->metadata_sm);
365 if (r < 0) {
366 DMERR("tm_create_with_sm failed");
367 return r;
368 }
369
370 __setup_mapping_info(cmd);
371
372 r = dm_array_empty(&cmd->info, &cmd->root);
373 if (r < 0)
374 goto bad;
375
376 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
377
378 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root);
379 if (r < 0)
380 goto bad;
381
382 cmd->discard_block_size = 0;
383 cmd->discard_nr_blocks = 0;
384
385 r = __write_initial_superblock(cmd);
386 if (r)
387 goto bad;
388
389 cmd->clean_when_opened = true;
390 return 0;
391
392bad:
393 dm_tm_destroy(cmd->tm);
394 dm_sm_destroy(cmd->metadata_sm);
395
396 return r;
397}
398
399static int __check_incompat_features(struct cache_disk_superblock *disk_super,
400 struct dm_cache_metadata *cmd)
401{
402 uint32_t features;
403
404 features = le32_to_cpu(disk_super->incompat_flags) & ~DM_CACHE_FEATURE_INCOMPAT_SUPP;
405 if (features) {
406 DMERR("could not access metadata due to unsupported optional features (%lx).",
407 (unsigned long)features);
408 return -EINVAL;
409 }
410
411 /*
412 * Check for read-only metadata to skip the following RDWR checks.
413 */
414 if (get_disk_ro(cmd->bdev->bd_disk))
415 return 0;
416
417 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP;
418 if (features) {
419 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
420 (unsigned long)features);
421 return -EINVAL;
422 }
423
424 return 0;
425}
426
427static int __open_metadata(struct dm_cache_metadata *cmd)
428{
429 int r;
430 struct dm_block *sblock;
431 struct cache_disk_superblock *disk_super;
432 unsigned long sb_flags;
433
434 r = superblock_read_lock(cmd, &sblock);
435 if (r < 0) {
436 DMERR("couldn't read lock superblock");
437 return r;
438 }
439
440 disk_super = dm_block_data(sblock);
441
Mike Snitzer048e5a02014-07-14 16:59:39 -0400442 /* Verify the data block size hasn't changed */
443 if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) {
444 DMERR("changing the data block size (from %u to %llu) is not supported",
445 le32_to_cpu(disk_super->data_block_size),
446 (unsigned long long)cmd->data_block_size);
447 r = -EINVAL;
448 goto bad;
449 }
450
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000451 r = __check_incompat_features(disk_super, cmd);
452 if (r < 0)
453 goto bad;
454
455 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
456 disk_super->metadata_space_map_root,
457 sizeof(disk_super->metadata_space_map_root),
458 &cmd->tm, &cmd->metadata_sm);
459 if (r < 0) {
460 DMERR("tm_open_with_sm failed");
461 goto bad;
462 }
463
464 __setup_mapping_info(cmd);
465 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
466 sb_flags = le32_to_cpu(disk_super->flags);
467 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
468 return dm_bm_unlock(sblock);
469
470bad:
471 dm_bm_unlock(sblock);
472 return r;
473}
474
475static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
476 bool format_device)
477{
Joe Thornberdd8b0c22013-10-24 14:10:28 -0400478 int r;
479 bool unformatted = false;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000480
481 r = __superblock_all_zeroes(cmd->bm, &unformatted);
482 if (r)
483 return r;
484
485 if (unformatted)
486 return format_device ? __format_metadata(cmd) : -EPERM;
487
488 return __open_metadata(cmd);
489}
490
491static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
492 bool may_format_device)
493{
494 int r;
Mike Snitzer895b47d2014-07-14 15:37:18 -0400495 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000496 CACHE_METADATA_CACHE_SIZE,
497 CACHE_MAX_CONCURRENT_LOCKS);
498 if (IS_ERR(cmd->bm)) {
499 DMERR("could not create block manager");
500 return PTR_ERR(cmd->bm);
501 }
502
503 r = __open_or_format_metadata(cmd, may_format_device);
504 if (r)
505 dm_block_manager_destroy(cmd->bm);
506
507 return r;
508}
509
510static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd)
511{
512 dm_sm_destroy(cmd->metadata_sm);
513 dm_tm_destroy(cmd->tm);
514 dm_block_manager_destroy(cmd->bm);
515}
516
517typedef unsigned long (*flags_mutator)(unsigned long);
518
519static void update_flags(struct cache_disk_superblock *disk_super,
520 flags_mutator mutator)
521{
522 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
523 disk_super->flags = cpu_to_le32(sb_flags);
524}
525
526static unsigned long set_clean_shutdown(unsigned long flags)
527{
528 set_bit(CLEAN_SHUTDOWN, &flags);
529 return flags;
530}
531
532static unsigned long clear_clean_shutdown(unsigned long flags)
533{
534 clear_bit(CLEAN_SHUTDOWN, &flags);
535 return flags;
536}
537
538static void read_superblock_fields(struct dm_cache_metadata *cmd,
539 struct cache_disk_superblock *disk_super)
540{
Joe Thornber028ae9f2015-04-22 16:42:35 -0400541 cmd->flags = le32_to_cpu(disk_super->flags);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000542 cmd->root = le64_to_cpu(disk_super->mapping_root);
543 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
544 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
545 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000546 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000547 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
548 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
549 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
Mike Snitzer4e7f5062013-03-20 17:21:27 +0000550 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
551 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
552 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000553 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
554
555 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
556 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
557 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
558 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
559
560 cmd->changed = false;
561}
562
563/*
564 * The mutator updates the superblock flags.
565 */
566static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
567 flags_mutator mutator)
568{
569 int r;
570 struct cache_disk_superblock *disk_super;
571 struct dm_block *sblock;
572
573 r = superblock_lock(cmd, &sblock);
574 if (r)
575 return r;
576
577 disk_super = dm_block_data(sblock);
578 update_flags(disk_super, mutator);
579 read_superblock_fields(cmd, disk_super);
Joe Thornbera9d45392014-03-27 14:13:20 +0000580 dm_bm_unlock(sblock);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000581
Joe Thornbera9d45392014-03-27 14:13:20 +0000582 return dm_bm_flush(cmd->bm);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000583}
584
585static int __begin_transaction(struct dm_cache_metadata *cmd)
586{
587 int r;
588 struct cache_disk_superblock *disk_super;
589 struct dm_block *sblock;
590
591 /*
592 * We re-read the superblock every time. Shouldn't need to do this
593 * really.
594 */
595 r = superblock_read_lock(cmd, &sblock);
596 if (r)
597 return r;
598
599 disk_super = dm_block_data(sblock);
600 read_superblock_fields(cmd, disk_super);
601 dm_bm_unlock(sblock);
602
603 return 0;
604}
605
606static int __commit_transaction(struct dm_cache_metadata *cmd,
607 flags_mutator mutator)
608{
609 int r;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000610 struct cache_disk_superblock *disk_super;
611 struct dm_block *sblock;
612
613 /*
614 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
615 */
616 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
617
618 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
619 &cmd->discard_root);
620 if (r)
621 return r;
622
623 r = dm_tm_pre_commit(cmd->tm);
624 if (r < 0)
625 return r;
626
Joe Thornber5a320832014-03-27 14:13:23 +0000627 r = __save_sm_root(cmd);
628 if (r)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000629 return r;
630
631 r = superblock_lock(cmd, &sblock);
632 if (r)
633 return r;
634
635 disk_super = dm_block_data(sblock);
636
637 if (mutator)
638 update_flags(disk_super, mutator);
639
Joe Thornber028ae9f2015-04-22 16:42:35 -0400640 disk_super->flags = cpu_to_le32(cmd->flags);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000641 disk_super->mapping_root = cpu_to_le64(cmd->root);
642 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
643 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
644 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000645 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000646 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
647 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
Mike Snitzer4e7f5062013-03-20 17:21:27 +0000648 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
649 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
650 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000651
652 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
653 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
654 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
655 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
Joe Thornber5a320832014-03-27 14:13:23 +0000656 __copy_sm_root(cmd, disk_super);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000657
658 return dm_tm_commit(cmd->tm, sblock);
659}
660
661/*----------------------------------------------------------------*/
662
663/*
664 * The mappings are held in a dm-array that has 64-bit values stored in
665 * little-endian format. The index is the cblock, the high 48bits of the
666 * value are the oblock and the low 16 bit the flags.
667 */
668#define FLAGS_MASK ((1 << 16) - 1)
669
670static __le64 pack_value(dm_oblock_t block, unsigned flags)
671{
672 uint64_t value = from_oblock(block);
673 value <<= 16;
674 value = value | (flags & FLAGS_MASK);
675 return cpu_to_le64(value);
676}
677
678static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
679{
680 uint64_t value = le64_to_cpu(value_le);
681 uint64_t b = value >> 16;
682 *block = to_oblock(b);
683 *flags = value & FLAGS_MASK;
684}
685
686/*----------------------------------------------------------------*/
687
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000688static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
689 sector_t data_block_size,
690 bool may_format_device,
691 size_t policy_hint_size)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000692{
693 int r;
694 struct dm_cache_metadata *cmd;
695
696 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
697 if (!cmd) {
698 DMERR("could not allocate metadata struct");
Joe Thornber766a7882015-01-28 12:07:46 +0000699 return ERR_PTR(-ENOMEM);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000700 }
701
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000702 atomic_set(&cmd->ref_count, 1);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000703 init_rwsem(&cmd->root_lock);
704 cmd->bdev = bdev;
705 cmd->data_block_size = data_block_size;
706 cmd->cache_blocks = 0;
707 cmd->policy_hint_size = policy_hint_size;
708 cmd->changed = true;
Joe Thornber028ae9f2015-04-22 16:42:35 -0400709 cmd->fail_io = false;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000710
711 r = __create_persistent_data_objects(cmd, may_format_device);
712 if (r) {
713 kfree(cmd);
714 return ERR_PTR(r);
715 }
716
717 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
718 if (r < 0) {
719 dm_cache_metadata_close(cmd);
720 return ERR_PTR(r);
721 }
722
723 return cmd;
724}
725
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000726/*
727 * We keep a little list of ref counted metadata objects to prevent two
728 * different target instances creating separate bufio instances. This is
729 * an issue if a table is reloaded before the suspend.
730 */
731static DEFINE_MUTEX(table_lock);
732static LIST_HEAD(table);
733
734static struct dm_cache_metadata *lookup(struct block_device *bdev)
735{
736 struct dm_cache_metadata *cmd;
737
738 list_for_each_entry(cmd, &table, list)
739 if (cmd->bdev == bdev) {
740 atomic_inc(&cmd->ref_count);
741 return cmd;
742 }
743
744 return NULL;
745}
746
747static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev,
748 sector_t data_block_size,
749 bool may_format_device,
750 size_t policy_hint_size)
751{
752 struct dm_cache_metadata *cmd, *cmd2;
753
754 mutex_lock(&table_lock);
755 cmd = lookup(bdev);
756 mutex_unlock(&table_lock);
757
758 if (cmd)
759 return cmd;
760
761 cmd = metadata_open(bdev, data_block_size, may_format_device, policy_hint_size);
Joe Thornber766a7882015-01-28 12:07:46 +0000762 if (!IS_ERR(cmd)) {
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000763 mutex_lock(&table_lock);
764 cmd2 = lookup(bdev);
765 if (cmd2) {
766 mutex_unlock(&table_lock);
767 __destroy_persistent_data_objects(cmd);
768 kfree(cmd);
769 return cmd2;
770 }
771 list_add(&cmd->list, &table);
772 mutex_unlock(&table_lock);
773 }
774
775 return cmd;
776}
777
778static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size)
779{
780 if (cmd->data_block_size != data_block_size) {
781 DMERR("data_block_size (%llu) different from that in metadata (%llu)\n",
782 (unsigned long long) data_block_size,
783 (unsigned long long) cmd->data_block_size);
784 return false;
785 }
786
787 return true;
788}
789
790struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
791 sector_t data_block_size,
792 bool may_format_device,
793 size_t policy_hint_size)
794{
795 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size,
796 may_format_device, policy_hint_size);
Joe Thornber766a7882015-01-28 12:07:46 +0000797
798 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) {
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000799 dm_cache_metadata_close(cmd);
Joe Thornber766a7882015-01-28 12:07:46 +0000800 return ERR_PTR(-EINVAL);
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000801 }
802
803 return cmd;
804}
805
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000806void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
807{
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000808 if (atomic_dec_and_test(&cmd->ref_count)) {
809 mutex_lock(&table_lock);
810 list_del(&cmd->list);
811 mutex_unlock(&table_lock);
812
Joe Thornber028ae9f2015-04-22 16:42:35 -0400813 if (!cmd->fail_io)
814 __destroy_persistent_data_objects(cmd);
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000815 kfree(cmd);
816 }
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000817}
818
Joe Thornberf494a9c2013-10-31 13:55:49 -0400819/*
820 * Checks that the given cache block is either unmapped or clean.
821 */
822static int block_unmapped_or_clean(struct dm_cache_metadata *cmd, dm_cblock_t b,
823 bool *result)
824{
825 int r;
826 __le64 value;
827 dm_oblock_t ob;
828 unsigned flags;
829
830 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
831 if (r) {
832 DMERR("block_unmapped_or_clean failed");
833 return r;
834 }
835
836 unpack_value(value, &ob, &flags);
837 *result = !((flags & M_VALID) && (flags & M_DIRTY));
838
839 return 0;
840}
841
842static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
843 dm_cblock_t begin, dm_cblock_t end,
844 bool *result)
845{
846 int r;
847 *result = true;
848
849 while (begin != end) {
850 r = block_unmapped_or_clean(cmd, begin, result);
851 if (r)
852 return r;
853
854 if (!*result) {
855 DMERR("cache block %llu is dirty",
856 (unsigned long long) from_cblock(begin));
857 return 0;
858 }
859
860 begin = to_cblock(from_cblock(begin) + 1);
861 }
862
863 return 0;
864}
865
Joe Thornber028ae9f2015-04-22 16:42:35 -0400866#define WRITE_LOCK(cmd) \
867 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \
868 return -EINVAL; \
869 down_write(&cmd->root_lock)
870
871#define WRITE_LOCK_VOID(cmd) \
872 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \
873 return; \
874 down_write(&cmd->root_lock)
875
876#define WRITE_UNLOCK(cmd) \
877 up_write(&cmd->root_lock)
878
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000879int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
880{
881 int r;
Joe Thornberf494a9c2013-10-31 13:55:49 -0400882 bool clean;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000883 __le64 null_mapping = pack_value(0, 0);
884
Joe Thornber028ae9f2015-04-22 16:42:35 -0400885 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000886 __dm_bless_for_disk(&null_mapping);
Joe Thornberf494a9c2013-10-31 13:55:49 -0400887
888 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
889 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
890 if (r) {
891 __dm_unbless_for_disk(&null_mapping);
892 goto out;
893 }
894
895 if (!clean) {
896 DMERR("unable to shrink cache due to dirty blocks");
897 r = -EINVAL;
898 __dm_unbless_for_disk(&null_mapping);
899 goto out;
900 }
901 }
902
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000903 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
904 from_cblock(new_cache_size),
905 &null_mapping, &cmd->root);
906 if (!r)
907 cmd->cache_blocks = new_cache_size;
908 cmd->changed = true;
Joe Thornberf494a9c2013-10-31 13:55:49 -0400909
910out:
Joe Thornber028ae9f2015-04-22 16:42:35 -0400911 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000912
913 return r;
914}
915
916int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
917 sector_t discard_block_size,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000918 dm_dblock_t new_nr_entries)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000919{
920 int r;
921
Joe Thornber028ae9f2015-04-22 16:42:35 -0400922 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000923 r = dm_bitset_resize(&cmd->discard_info,
924 cmd->discard_root,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000925 from_dblock(cmd->discard_nr_blocks),
926 from_dblock(new_nr_entries),
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000927 false, &cmd->discard_root);
928 if (!r) {
929 cmd->discard_block_size = discard_block_size;
930 cmd->discard_nr_blocks = new_nr_entries;
931 }
932
933 cmd->changed = true;
Joe Thornber028ae9f2015-04-22 16:42:35 -0400934 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000935
936 return r;
937}
938
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000939static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000940{
941 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000942 from_dblock(b), &cmd->discard_root);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000943}
944
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000945static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000946{
947 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000948 from_dblock(b), &cmd->discard_root);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000949}
950
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000951static int __is_discarded(struct dm_cache_metadata *cmd, dm_dblock_t b,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000952 bool *is_discarded)
953{
954 return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000955 from_dblock(b), &cmd->discard_root,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000956 is_discarded);
957}
958
959static int __discard(struct dm_cache_metadata *cmd,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000960 dm_dblock_t dblock, bool discard)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000961{
962 int r;
963
964 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
965 if (r)
966 return r;
967
968 cmd->changed = true;
969 return 0;
970}
971
972int dm_cache_set_discard(struct dm_cache_metadata *cmd,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000973 dm_dblock_t dblock, bool discard)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000974{
975 int r;
976
Joe Thornber028ae9f2015-04-22 16:42:35 -0400977 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000978 r = __discard(cmd, dblock, discard);
Joe Thornber028ae9f2015-04-22 16:42:35 -0400979 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000980
981 return r;
982}
983
984static int __load_discards(struct dm_cache_metadata *cmd,
985 load_discard_fn fn, void *context)
986{
987 int r = 0;
988 dm_block_t b;
989 bool discard;
990
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000991 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
992 dm_dblock_t dblock = to_dblock(b);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000993
994 if (cmd->clean_when_opened) {
995 r = __is_discarded(cmd, dblock, &discard);
996 if (r)
997 return r;
998 } else
999 discard = false;
1000
1001 r = fn(context, cmd->discard_block_size, dblock, discard);
1002 if (r)
1003 break;
1004 }
1005
1006 return r;
1007}
1008
1009int dm_cache_load_discards(struct dm_cache_metadata *cmd,
1010 load_discard_fn fn, void *context)
1011{
1012 int r;
1013
1014 down_read(&cmd->root_lock);
1015 r = __load_discards(cmd, fn, context);
1016 up_read(&cmd->root_lock);
1017
1018 return r;
1019}
1020
1021dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd)
1022{
1023 dm_cblock_t r;
1024
1025 down_read(&cmd->root_lock);
1026 r = cmd->cache_blocks;
1027 up_read(&cmd->root_lock);
1028
1029 return r;
1030}
1031
1032static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1033{
1034 int r;
1035 __le64 value = pack_value(0, 0);
1036
1037 __dm_bless_for_disk(&value);
1038 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1039 &value, &cmd->root);
1040 if (r)
1041 return r;
1042
1043 cmd->changed = true;
1044 return 0;
1045}
1046
1047int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1048{
1049 int r;
1050
Joe Thornber028ae9f2015-04-22 16:42:35 -04001051 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001052 r = __remove(cmd, cblock);
Joe Thornber028ae9f2015-04-22 16:42:35 -04001053 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001054
1055 return r;
1056}
1057
1058static int __insert(struct dm_cache_metadata *cmd,
1059 dm_cblock_t cblock, dm_oblock_t oblock)
1060{
1061 int r;
1062 __le64 value = pack_value(oblock, M_VALID);
1063 __dm_bless_for_disk(&value);
1064
1065 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1066 &value, &cmd->root);
1067 if (r)
1068 return r;
1069
1070 cmd->changed = true;
1071 return 0;
1072}
1073
1074int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
1075 dm_cblock_t cblock, dm_oblock_t oblock)
1076{
1077 int r;
1078
Joe Thornber028ae9f2015-04-22 16:42:35 -04001079 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001080 r = __insert(cmd, cblock, oblock);
Joe Thornber028ae9f2015-04-22 16:42:35 -04001081 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001082
1083 return r;
1084}
1085
1086struct thunk {
1087 load_mapping_fn fn;
1088 void *context;
1089
1090 struct dm_cache_metadata *cmd;
1091 bool respect_dirty_flags;
1092 bool hints_valid;
1093};
1094
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001095static bool policy_unchanged(struct dm_cache_metadata *cmd,
1096 struct dm_cache_policy *policy)
1097{
1098 const char *policy_name = dm_cache_policy_get_name(policy);
1099 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1100 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
1101
1102 /*
1103 * Ensure policy names match.
1104 */
1105 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
1106 return false;
1107
1108 /*
1109 * Ensure policy major versions match.
1110 */
1111 if (cmd->policy_version[0] != policy_version[0])
1112 return false;
1113
1114 /*
1115 * Ensure policy hint sizes match.
1116 */
1117 if (cmd->policy_hint_size != policy_hint_size)
1118 return false;
1119
1120 return true;
1121}
1122
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001123static bool hints_array_initialized(struct dm_cache_metadata *cmd)
1124{
1125 return cmd->hint_root && cmd->policy_hint_size;
1126}
1127
1128static bool hints_array_available(struct dm_cache_metadata *cmd,
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001129 struct dm_cache_policy *policy)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001130{
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001131 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001132 hints_array_initialized(cmd);
1133}
1134
1135static int __load_mapping(void *context, uint64_t cblock, void *leaf)
1136{
1137 int r = 0;
1138 bool dirty;
1139 __le64 value;
1140 __le32 hint_value = 0;
1141 dm_oblock_t oblock;
1142 unsigned flags;
1143 struct thunk *thunk = context;
1144 struct dm_cache_metadata *cmd = thunk->cmd;
1145
1146 memcpy(&value, leaf, sizeof(value));
1147 unpack_value(value, &oblock, &flags);
1148
1149 if (flags & M_VALID) {
1150 if (thunk->hints_valid) {
1151 r = dm_array_get_value(&cmd->hint_info, cmd->hint_root,
1152 cblock, &hint_value);
1153 if (r && r != -ENODATA)
1154 return r;
1155 }
1156
1157 dirty = thunk->respect_dirty_flags ? (flags & M_DIRTY) : true;
1158 r = thunk->fn(thunk->context, oblock, to_cblock(cblock),
1159 dirty, le32_to_cpu(hint_value), thunk->hints_valid);
1160 }
1161
1162 return r;
1163}
1164
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001165static int __load_mappings(struct dm_cache_metadata *cmd,
1166 struct dm_cache_policy *policy,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001167 load_mapping_fn fn, void *context)
1168{
1169 struct thunk thunk;
1170
1171 thunk.fn = fn;
1172 thunk.context = context;
1173
1174 thunk.cmd = cmd;
1175 thunk.respect_dirty_flags = cmd->clean_when_opened;
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001176 thunk.hints_valid = hints_array_available(cmd, policy);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001177
1178 return dm_array_walk(&cmd->info, cmd->root, __load_mapping, &thunk);
1179}
1180
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001181int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
1182 struct dm_cache_policy *policy,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001183 load_mapping_fn fn, void *context)
1184{
1185 int r;
1186
1187 down_read(&cmd->root_lock);
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001188 r = __load_mappings(cmd, policy, fn, context);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001189 up_read(&cmd->root_lock);
1190
1191 return r;
1192}
1193
1194static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
1195{
1196 int r = 0;
1197 __le64 value;
1198 dm_oblock_t oblock;
1199 unsigned flags;
1200
1201 memcpy(&value, leaf, sizeof(value));
1202 unpack_value(value, &oblock, &flags);
1203
1204 return r;
1205}
1206
1207static int __dump_mappings(struct dm_cache_metadata *cmd)
1208{
1209 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
1210}
1211
1212void dm_cache_dump(struct dm_cache_metadata *cmd)
1213{
1214 down_read(&cmd->root_lock);
1215 __dump_mappings(cmd);
1216 up_read(&cmd->root_lock);
1217}
1218
1219int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1220{
1221 int r;
1222
1223 down_read(&cmd->root_lock);
1224 r = cmd->changed;
1225 up_read(&cmd->root_lock);
1226
1227 return r;
1228}
1229
1230static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1231{
1232 int r;
1233 unsigned flags;
1234 dm_oblock_t oblock;
1235 __le64 value;
1236
1237 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1238 if (r)
1239 return r;
1240
1241 unpack_value(value, &oblock, &flags);
1242
1243 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1244 /* nothing to be done */
1245 return 0;
1246
Joe Thornber79ed9ca2013-03-20 17:21:27 +00001247 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001248 __dm_bless_for_disk(&value);
1249
1250 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1251 &value, &cmd->root);
1252 if (r)
1253 return r;
1254
1255 cmd->changed = true;
1256 return 0;
1257
1258}
1259
1260int dm_cache_set_dirty(struct dm_cache_metadata *cmd,
1261 dm_cblock_t cblock, bool dirty)
1262{
1263 int r;
1264
Joe Thornber028ae9f2015-04-22 16:42:35 -04001265 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001266 r = __dirty(cmd, cblock, dirty);
Joe Thornber028ae9f2015-04-22 16:42:35 -04001267 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001268
1269 return r;
1270}
1271
1272void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1273 struct dm_cache_statistics *stats)
1274{
1275 down_read(&cmd->root_lock);
Joe Thornber8c5008f2013-05-10 14:37:18 +01001276 *stats = cmd->stats;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001277 up_read(&cmd->root_lock);
1278}
1279
1280void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1281 struct dm_cache_statistics *stats)
1282{
Joe Thornber028ae9f2015-04-22 16:42:35 -04001283 WRITE_LOCK_VOID(cmd);
Joe Thornber8c5008f2013-05-10 14:37:18 +01001284 cmd->stats = *stats;
Joe Thornber028ae9f2015-04-22 16:42:35 -04001285 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001286}
1287
1288int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1289{
1290 int r;
1291 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1292 clear_clean_shutdown);
1293
Joe Thornber028ae9f2015-04-22 16:42:35 -04001294 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001295 r = __commit_transaction(cmd, mutator);
1296 if (r)
1297 goto out;
1298
1299 r = __begin_transaction(cmd);
1300
1301out:
Joe Thornber028ae9f2015-04-22 16:42:35 -04001302 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001303 return r;
1304}
1305
1306int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1307 dm_block_t *result)
1308{
1309 int r = -EINVAL;
1310
1311 down_read(&cmd->root_lock);
1312 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1313 up_read(&cmd->root_lock);
1314
1315 return r;
1316}
1317
1318int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1319 dm_block_t *result)
1320{
1321 int r = -EINVAL;
1322
1323 down_read(&cmd->root_lock);
1324 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1325 up_read(&cmd->root_lock);
1326
1327 return r;
1328}
1329
1330/*----------------------------------------------------------------*/
1331
1332static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1333{
1334 int r;
1335 __le32 value;
1336 size_t hint_size;
1337 const char *policy_name = dm_cache_policy_get_name(policy);
Mike Snitzer4e7f5062013-03-20 17:21:27 +00001338 const unsigned *policy_version = dm_cache_policy_get_version(policy);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001339
1340 if (!policy_name[0] ||
1341 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1342 return -EINVAL;
1343
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001344 if (!policy_unchanged(cmd, policy)) {
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001345 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
Mike Snitzer4e7f5062013-03-20 17:21:27 +00001346 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001347
1348 hint_size = dm_cache_policy_get_hint_size(policy);
1349 if (!hint_size)
1350 return 0; /* short-circuit hints initialization */
1351 cmd->policy_hint_size = hint_size;
1352
1353 if (cmd->hint_root) {
1354 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1355 if (r)
1356 return r;
1357 }
1358
1359 r = dm_array_empty(&cmd->hint_info, &cmd->hint_root);
1360 if (r)
1361 return r;
1362
1363 value = cpu_to_le32(0);
1364 __dm_bless_for_disk(&value);
1365 r = dm_array_resize(&cmd->hint_info, cmd->hint_root, 0,
1366 from_cblock(cmd->cache_blocks),
1367 &value, &cmd->hint_root);
1368 if (r)
1369 return r;
1370 }
1371
1372 return 0;
1373}
1374
Joe Thornber05966612014-04-03 16:16:44 +01001375static int save_hint(void *context, dm_cblock_t cblock, dm_oblock_t oblock, uint32_t hint)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001376{
Joe Thornber05966612014-04-03 16:16:44 +01001377 struct dm_cache_metadata *cmd = context;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001378 __le32 value = cpu_to_le32(hint);
Joe Thornber05966612014-04-03 16:16:44 +01001379 int r;
1380
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001381 __dm_bless_for_disk(&value);
1382
1383 r = dm_array_set_value(&cmd->hint_info, cmd->hint_root,
1384 from_cblock(cblock), &value, &cmd->hint_root);
1385 cmd->changed = true;
1386
1387 return r;
1388}
1389
Joe Thornber05966612014-04-03 16:16:44 +01001390static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001391{
1392 int r;
1393
Joe Thornber05966612014-04-03 16:16:44 +01001394 r = begin_hints(cmd, policy);
1395 if (r) {
1396 DMERR("begin_hints failed");
1397 return r;
1398 }
1399
1400 return policy_walk_mappings(policy, save_hint, cmd);
1401}
1402
1403int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1404{
1405 int r;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001406
Joe Thornber028ae9f2015-04-22 16:42:35 -04001407 WRITE_LOCK(cmd);
Joe Thornber05966612014-04-03 16:16:44 +01001408 r = write_hints(cmd, policy);
Joe Thornber028ae9f2015-04-22 16:42:35 -04001409 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001410
1411 return r;
1412}
Joe Thornber2ee57d52013-10-24 14:10:29 -04001413
1414int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
1415{
1416 return blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
1417}
Joe Thornber028ae9f2015-04-22 16:42:35 -04001418
1419void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
1420{
1421 WRITE_LOCK_VOID(cmd);
1422 dm_bm_set_read_only(cmd->bm);
1423 WRITE_UNLOCK(cmd);
1424}
1425
1426void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
1427{
1428 WRITE_LOCK_VOID(cmd);
1429 dm_bm_set_read_write(cmd->bm);
1430 WRITE_UNLOCK(cmd);
1431}
1432
1433int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
1434{
1435 int r;
1436 struct dm_block *sblock;
1437 struct cache_disk_superblock *disk_super;
1438
1439 /*
1440 * We ignore fail_io for this function.
1441 */
1442 down_write(&cmd->root_lock);
1443 set_bit(NEEDS_CHECK, &cmd->flags);
1444
1445 r = superblock_lock(cmd, &sblock);
1446 if (r) {
1447 DMERR("couldn't read superblock");
1448 goto out;
1449 }
1450
1451 disk_super = dm_block_data(sblock);
1452 disk_super->flags = cpu_to_le32(cmd->flags);
1453
1454 dm_bm_unlock(sblock);
1455
1456out:
1457 up_write(&cmd->root_lock);
1458 return r;
1459}
1460
1461bool dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd)
1462{
1463 bool needs_check;
1464
1465 down_read(&cmd->root_lock);
1466 needs_check = !!test_bit(NEEDS_CHECK, &cmd->flags);
1467 up_read(&cmd->root_lock);
1468
1469 return needs_check;
1470}
1471
1472int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
1473{
1474 int r;
1475
1476 WRITE_LOCK(cmd);
1477 __destroy_persistent_data_objects(cmd);
1478 r = __create_persistent_data_objects(cmd, false);
1479 if (r)
1480 cmd->fail_io = true;
1481 WRITE_UNLOCK(cmd);
1482
1483 return r;
1484}