blob: f6543f3a970f8daf44f3523e0209fd85a3c13f0b [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
Mikulas Patocka4c7da062015-10-22 16:46:59 -0400263 dm_bm_unlock(b);
264
265 return 0;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000266}
267
268static void __setup_mapping_info(struct dm_cache_metadata *cmd)
269{
270 struct dm_btree_value_type vt;
271
272 vt.context = NULL;
273 vt.size = sizeof(__le64);
274 vt.inc = NULL;
275 vt.dec = NULL;
276 vt.equal = NULL;
277 dm_array_info_init(&cmd->info, cmd->tm, &vt);
278
279 if (cmd->policy_hint_size) {
280 vt.size = sizeof(__le32);
281 dm_array_info_init(&cmd->hint_info, cmd->tm, &vt);
282 }
283}
284
Joe Thornber5a320832014-03-27 14:13:23 +0000285static int __save_sm_root(struct dm_cache_metadata *cmd)
286{
287 int r;
288 size_t metadata_len;
289
290 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
291 if (r < 0)
292 return r;
293
294 return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
295 metadata_len);
296}
297
298static void __copy_sm_root(struct dm_cache_metadata *cmd,
299 struct cache_disk_superblock *disk_super)
300{
301 memcpy(&disk_super->metadata_space_map_root,
302 &cmd->metadata_space_map_root,
303 sizeof(cmd->metadata_space_map_root));
304}
305
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000306static int __write_initial_superblock(struct dm_cache_metadata *cmd)
307{
308 int r;
309 struct dm_block *sblock;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000310 struct cache_disk_superblock *disk_super;
311 sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
312
313 /* FIXME: see if we can lose the max sectors limit */
314 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
315 bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
316
Joe Thornber5a320832014-03-27 14:13:23 +0000317 r = dm_tm_pre_commit(cmd->tm);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000318 if (r < 0)
319 return r;
320
Joe Thornber5a320832014-03-27 14:13:23 +0000321 /*
322 * dm_sm_copy_root() can fail. So we need to do it before we start
323 * updating the superblock.
324 */
325 r = __save_sm_root(cmd);
326 if (r)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000327 return r;
328
329 r = superblock_lock_zero(cmd, &sblock);
330 if (r)
331 return r;
332
333 disk_super = dm_block_data(sblock);
334 disk_super->flags = 0;
335 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
336 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
Joe Thornber53d49812013-10-16 10:59:26 +0100337 disk_super->version = cpu_to_le32(MAX_CACHE_VERSION);
Mike Snitzer4e7f5062013-03-20 17:21:27 +0000338 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
339 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000340 disk_super->policy_hint_size = 0;
341
Joe Thornber5a320832014-03-27 14:13:23 +0000342 __copy_sm_root(cmd, disk_super);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000343
344 disk_super->mapping_root = cpu_to_le64(cmd->root);
345 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
346 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
347 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000348 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
Mike Snitzer895b47d2014-07-14 15:37:18 -0400349 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000350 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
351 disk_super->cache_blocks = cpu_to_le32(0);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000352
353 disk_super->read_hits = cpu_to_le32(0);
354 disk_super->read_misses = cpu_to_le32(0);
355 disk_super->write_hits = cpu_to_le32(0);
356 disk_super->write_misses = cpu_to_le32(0);
357
358 return dm_tm_commit(cmd->tm, sblock);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000359}
360
361static int __format_metadata(struct dm_cache_metadata *cmd)
362{
363 int r;
364
365 r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
366 &cmd->tm, &cmd->metadata_sm);
367 if (r < 0) {
368 DMERR("tm_create_with_sm failed");
369 return r;
370 }
371
372 __setup_mapping_info(cmd);
373
374 r = dm_array_empty(&cmd->info, &cmd->root);
375 if (r < 0)
376 goto bad;
377
378 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
379
380 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root);
381 if (r < 0)
382 goto bad;
383
384 cmd->discard_block_size = 0;
385 cmd->discard_nr_blocks = 0;
386
387 r = __write_initial_superblock(cmd);
388 if (r)
389 goto bad;
390
391 cmd->clean_when_opened = true;
392 return 0;
393
394bad:
395 dm_tm_destroy(cmd->tm);
396 dm_sm_destroy(cmd->metadata_sm);
397
398 return r;
399}
400
401static int __check_incompat_features(struct cache_disk_superblock *disk_super,
402 struct dm_cache_metadata *cmd)
403{
404 uint32_t features;
405
406 features = le32_to_cpu(disk_super->incompat_flags) & ~DM_CACHE_FEATURE_INCOMPAT_SUPP;
407 if (features) {
408 DMERR("could not access metadata due to unsupported optional features (%lx).",
409 (unsigned long)features);
410 return -EINVAL;
411 }
412
413 /*
414 * Check for read-only metadata to skip the following RDWR checks.
415 */
416 if (get_disk_ro(cmd->bdev->bd_disk))
417 return 0;
418
419 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP;
420 if (features) {
421 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
422 (unsigned long)features);
423 return -EINVAL;
424 }
425
426 return 0;
427}
428
429static int __open_metadata(struct dm_cache_metadata *cmd)
430{
431 int r;
432 struct dm_block *sblock;
433 struct cache_disk_superblock *disk_super;
434 unsigned long sb_flags;
435
436 r = superblock_read_lock(cmd, &sblock);
437 if (r < 0) {
438 DMERR("couldn't read lock superblock");
439 return r;
440 }
441
442 disk_super = dm_block_data(sblock);
443
Mike Snitzer048e5a02014-07-14 16:59:39 -0400444 /* Verify the data block size hasn't changed */
445 if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) {
446 DMERR("changing the data block size (from %u to %llu) is not supported",
447 le32_to_cpu(disk_super->data_block_size),
448 (unsigned long long)cmd->data_block_size);
449 r = -EINVAL;
450 goto bad;
451 }
452
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000453 r = __check_incompat_features(disk_super, cmd);
454 if (r < 0)
455 goto bad;
456
457 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
458 disk_super->metadata_space_map_root,
459 sizeof(disk_super->metadata_space_map_root),
460 &cmd->tm, &cmd->metadata_sm);
461 if (r < 0) {
462 DMERR("tm_open_with_sm failed");
463 goto bad;
464 }
465
466 __setup_mapping_info(cmd);
467 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
468 sb_flags = le32_to_cpu(disk_super->flags);
469 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
Mikulas Patocka4c7da062015-10-22 16:46:59 -0400470 dm_bm_unlock(sblock);
471
472 return 0;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000473
474bad:
475 dm_bm_unlock(sblock);
476 return r;
477}
478
479static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
480 bool format_device)
481{
Joe Thornberdd8b0c22013-10-24 14:10:28 -0400482 int r;
483 bool unformatted = false;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000484
485 r = __superblock_all_zeroes(cmd->bm, &unformatted);
486 if (r)
487 return r;
488
489 if (unformatted)
490 return format_device ? __format_metadata(cmd) : -EPERM;
491
492 return __open_metadata(cmd);
493}
494
495static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
496 bool may_format_device)
497{
498 int r;
Mike Snitzer895b47d2014-07-14 15:37:18 -0400499 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000500 CACHE_METADATA_CACHE_SIZE,
501 CACHE_MAX_CONCURRENT_LOCKS);
502 if (IS_ERR(cmd->bm)) {
503 DMERR("could not create block manager");
504 return PTR_ERR(cmd->bm);
505 }
506
507 r = __open_or_format_metadata(cmd, may_format_device);
508 if (r)
509 dm_block_manager_destroy(cmd->bm);
510
511 return r;
512}
513
514static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd)
515{
516 dm_sm_destroy(cmd->metadata_sm);
517 dm_tm_destroy(cmd->tm);
518 dm_block_manager_destroy(cmd->bm);
519}
520
521typedef unsigned long (*flags_mutator)(unsigned long);
522
523static void update_flags(struct cache_disk_superblock *disk_super,
524 flags_mutator mutator)
525{
526 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
527 disk_super->flags = cpu_to_le32(sb_flags);
528}
529
530static unsigned long set_clean_shutdown(unsigned long flags)
531{
532 set_bit(CLEAN_SHUTDOWN, &flags);
533 return flags;
534}
535
536static unsigned long clear_clean_shutdown(unsigned long flags)
537{
538 clear_bit(CLEAN_SHUTDOWN, &flags);
539 return flags;
540}
541
542static void read_superblock_fields(struct dm_cache_metadata *cmd,
543 struct cache_disk_superblock *disk_super)
544{
Joe Thornber028ae9f2015-04-22 16:42:35 -0400545 cmd->flags = le32_to_cpu(disk_super->flags);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000546 cmd->root = le64_to_cpu(disk_super->mapping_root);
547 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
548 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
549 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000550 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000551 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
552 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
553 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
Mike Snitzer4e7f5062013-03-20 17:21:27 +0000554 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
555 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
556 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000557 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
558
559 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
560 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
561 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
562 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
563
564 cmd->changed = false;
565}
566
567/*
568 * The mutator updates the superblock flags.
569 */
570static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
571 flags_mutator mutator)
572{
573 int r;
574 struct cache_disk_superblock *disk_super;
575 struct dm_block *sblock;
576
577 r = superblock_lock(cmd, &sblock);
578 if (r)
579 return r;
580
581 disk_super = dm_block_data(sblock);
582 update_flags(disk_super, mutator);
583 read_superblock_fields(cmd, disk_super);
Joe Thornbera9d45392014-03-27 14:13:20 +0000584 dm_bm_unlock(sblock);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000585
Joe Thornbera9d45392014-03-27 14:13:20 +0000586 return dm_bm_flush(cmd->bm);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000587}
588
589static int __begin_transaction(struct dm_cache_metadata *cmd)
590{
591 int r;
592 struct cache_disk_superblock *disk_super;
593 struct dm_block *sblock;
594
595 /*
596 * We re-read the superblock every time. Shouldn't need to do this
597 * really.
598 */
599 r = superblock_read_lock(cmd, &sblock);
600 if (r)
601 return r;
602
603 disk_super = dm_block_data(sblock);
604 read_superblock_fields(cmd, disk_super);
605 dm_bm_unlock(sblock);
606
607 return 0;
608}
609
610static int __commit_transaction(struct dm_cache_metadata *cmd,
611 flags_mutator mutator)
612{
613 int r;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000614 struct cache_disk_superblock *disk_super;
615 struct dm_block *sblock;
616
617 /*
618 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
619 */
620 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
621
622 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
623 &cmd->discard_root);
624 if (r)
625 return r;
626
627 r = dm_tm_pre_commit(cmd->tm);
628 if (r < 0)
629 return r;
630
Joe Thornber5a320832014-03-27 14:13:23 +0000631 r = __save_sm_root(cmd);
632 if (r)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000633 return r;
634
635 r = superblock_lock(cmd, &sblock);
636 if (r)
637 return r;
638
639 disk_super = dm_block_data(sblock);
640
Joe Thornber3201ac42015-10-22 18:10:55 +0100641 disk_super->flags = cpu_to_le32(cmd->flags);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000642 if (mutator)
643 update_flags(disk_super, mutator);
644
645 disk_super->mapping_root = cpu_to_le64(cmd->root);
646 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
647 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
648 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000649 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000650 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
651 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
Mike Snitzer4e7f5062013-03-20 17:21:27 +0000652 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
653 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
654 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000655
656 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
657 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
658 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
659 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
Joe Thornber5a320832014-03-27 14:13:23 +0000660 __copy_sm_root(cmd, disk_super);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000661
662 return dm_tm_commit(cmd->tm, sblock);
663}
664
665/*----------------------------------------------------------------*/
666
667/*
668 * The mappings are held in a dm-array that has 64-bit values stored in
669 * little-endian format. The index is the cblock, the high 48bits of the
670 * value are the oblock and the low 16 bit the flags.
671 */
672#define FLAGS_MASK ((1 << 16) - 1)
673
674static __le64 pack_value(dm_oblock_t block, unsigned flags)
675{
676 uint64_t value = from_oblock(block);
677 value <<= 16;
678 value = value | (flags & FLAGS_MASK);
679 return cpu_to_le64(value);
680}
681
682static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
683{
684 uint64_t value = le64_to_cpu(value_le);
685 uint64_t b = value >> 16;
686 *block = to_oblock(b);
687 *flags = value & FLAGS_MASK;
688}
689
690/*----------------------------------------------------------------*/
691
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000692static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
693 sector_t data_block_size,
694 bool may_format_device,
695 size_t policy_hint_size)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000696{
697 int r;
698 struct dm_cache_metadata *cmd;
699
700 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
701 if (!cmd) {
702 DMERR("could not allocate metadata struct");
Joe Thornber766a7882015-01-28 12:07:46 +0000703 return ERR_PTR(-ENOMEM);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000704 }
705
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000706 atomic_set(&cmd->ref_count, 1);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000707 init_rwsem(&cmd->root_lock);
708 cmd->bdev = bdev;
709 cmd->data_block_size = data_block_size;
710 cmd->cache_blocks = 0;
711 cmd->policy_hint_size = policy_hint_size;
712 cmd->changed = true;
Joe Thornber028ae9f2015-04-22 16:42:35 -0400713 cmd->fail_io = false;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000714
715 r = __create_persistent_data_objects(cmd, may_format_device);
716 if (r) {
717 kfree(cmd);
718 return ERR_PTR(r);
719 }
720
721 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
722 if (r < 0) {
723 dm_cache_metadata_close(cmd);
724 return ERR_PTR(r);
725 }
726
727 return cmd;
728}
729
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000730/*
731 * We keep a little list of ref counted metadata objects to prevent two
732 * different target instances creating separate bufio instances. This is
733 * an issue if a table is reloaded before the suspend.
734 */
735static DEFINE_MUTEX(table_lock);
736static LIST_HEAD(table);
737
738static struct dm_cache_metadata *lookup(struct block_device *bdev)
739{
740 struct dm_cache_metadata *cmd;
741
742 list_for_each_entry(cmd, &table, list)
743 if (cmd->bdev == bdev) {
744 atomic_inc(&cmd->ref_count);
745 return cmd;
746 }
747
748 return NULL;
749}
750
751static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev,
752 sector_t data_block_size,
753 bool may_format_device,
754 size_t policy_hint_size)
755{
756 struct dm_cache_metadata *cmd, *cmd2;
757
758 mutex_lock(&table_lock);
759 cmd = lookup(bdev);
760 mutex_unlock(&table_lock);
761
762 if (cmd)
763 return cmd;
764
765 cmd = metadata_open(bdev, data_block_size, may_format_device, policy_hint_size);
Joe Thornber766a7882015-01-28 12:07:46 +0000766 if (!IS_ERR(cmd)) {
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000767 mutex_lock(&table_lock);
768 cmd2 = lookup(bdev);
769 if (cmd2) {
770 mutex_unlock(&table_lock);
771 __destroy_persistent_data_objects(cmd);
772 kfree(cmd);
773 return cmd2;
774 }
775 list_add(&cmd->list, &table);
776 mutex_unlock(&table_lock);
777 }
778
779 return cmd;
780}
781
782static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size)
783{
784 if (cmd->data_block_size != data_block_size) {
785 DMERR("data_block_size (%llu) different from that in metadata (%llu)\n",
786 (unsigned long long) data_block_size,
787 (unsigned long long) cmd->data_block_size);
788 return false;
789 }
790
791 return true;
792}
793
794struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
795 sector_t data_block_size,
796 bool may_format_device,
797 size_t policy_hint_size)
798{
799 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size,
800 may_format_device, policy_hint_size);
Joe Thornber766a7882015-01-28 12:07:46 +0000801
802 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) {
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000803 dm_cache_metadata_close(cmd);
Joe Thornber766a7882015-01-28 12:07:46 +0000804 return ERR_PTR(-EINVAL);
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000805 }
806
807 return cmd;
808}
809
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000810void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
811{
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000812 if (atomic_dec_and_test(&cmd->ref_count)) {
813 mutex_lock(&table_lock);
814 list_del(&cmd->list);
815 mutex_unlock(&table_lock);
816
Joe Thornber028ae9f2015-04-22 16:42:35 -0400817 if (!cmd->fail_io)
818 __destroy_persistent_data_objects(cmd);
Joe Thornber9b1cc9f2015-01-23 10:00:07 +0000819 kfree(cmd);
820 }
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000821}
822
Joe Thornberf494a9c2013-10-31 13:55:49 -0400823/*
824 * Checks that the given cache block is either unmapped or clean.
825 */
826static int block_unmapped_or_clean(struct dm_cache_metadata *cmd, dm_cblock_t b,
827 bool *result)
828{
829 int r;
830 __le64 value;
831 dm_oblock_t ob;
832 unsigned flags;
833
834 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
835 if (r) {
836 DMERR("block_unmapped_or_clean failed");
837 return r;
838 }
839
840 unpack_value(value, &ob, &flags);
841 *result = !((flags & M_VALID) && (flags & M_DIRTY));
842
843 return 0;
844}
845
846static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
847 dm_cblock_t begin, dm_cblock_t end,
848 bool *result)
849{
850 int r;
851 *result = true;
852
853 while (begin != end) {
854 r = block_unmapped_or_clean(cmd, begin, result);
855 if (r)
856 return r;
857
858 if (!*result) {
859 DMERR("cache block %llu is dirty",
860 (unsigned long long) from_cblock(begin));
861 return 0;
862 }
863
864 begin = to_cblock(from_cblock(begin) + 1);
865 }
866
867 return 0;
868}
869
Joe Thornber028ae9f2015-04-22 16:42:35 -0400870#define WRITE_LOCK(cmd) \
871 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \
872 return -EINVAL; \
873 down_write(&cmd->root_lock)
874
875#define WRITE_LOCK_VOID(cmd) \
876 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \
877 return; \
878 down_write(&cmd->root_lock)
879
880#define WRITE_UNLOCK(cmd) \
881 up_write(&cmd->root_lock)
882
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000883int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
884{
885 int r;
Joe Thornberf494a9c2013-10-31 13:55:49 -0400886 bool clean;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000887 __le64 null_mapping = pack_value(0, 0);
888
Joe Thornber028ae9f2015-04-22 16:42:35 -0400889 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000890 __dm_bless_for_disk(&null_mapping);
Joe Thornberf494a9c2013-10-31 13:55:49 -0400891
892 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
893 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
894 if (r) {
895 __dm_unbless_for_disk(&null_mapping);
896 goto out;
897 }
898
899 if (!clean) {
900 DMERR("unable to shrink cache due to dirty blocks");
901 r = -EINVAL;
902 __dm_unbless_for_disk(&null_mapping);
903 goto out;
904 }
905 }
906
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000907 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
908 from_cblock(new_cache_size),
909 &null_mapping, &cmd->root);
910 if (!r)
911 cmd->cache_blocks = new_cache_size;
912 cmd->changed = true;
Joe Thornberf494a9c2013-10-31 13:55:49 -0400913
914out:
Joe Thornber028ae9f2015-04-22 16:42:35 -0400915 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000916
917 return r;
918}
919
920int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
921 sector_t discard_block_size,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000922 dm_dblock_t new_nr_entries)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000923{
924 int r;
925
Joe Thornber028ae9f2015-04-22 16:42:35 -0400926 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000927 r = dm_bitset_resize(&cmd->discard_info,
928 cmd->discard_root,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000929 from_dblock(cmd->discard_nr_blocks),
930 from_dblock(new_nr_entries),
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000931 false, &cmd->discard_root);
932 if (!r) {
933 cmd->discard_block_size = discard_block_size;
934 cmd->discard_nr_blocks = new_nr_entries;
935 }
936
937 cmd->changed = true;
Joe Thornber028ae9f2015-04-22 16:42:35 -0400938 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000939
940 return r;
941}
942
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000943static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000944{
945 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000946 from_dblock(b), &cmd->discard_root);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000947}
948
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000949static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000950{
951 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000952 from_dblock(b), &cmd->discard_root);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000953}
954
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000955static int __is_discarded(struct dm_cache_metadata *cmd, dm_dblock_t b,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000956 bool *is_discarded)
957{
958 return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000959 from_dblock(b), &cmd->discard_root,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000960 is_discarded);
961}
962
963static int __discard(struct dm_cache_metadata *cmd,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000964 dm_dblock_t dblock, bool discard)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000965{
966 int r;
967
968 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
969 if (r)
970 return r;
971
972 cmd->changed = true;
973 return 0;
974}
975
976int dm_cache_set_discard(struct dm_cache_metadata *cmd,
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000977 dm_dblock_t dblock, bool discard)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000978{
979 int r;
980
Joe Thornber028ae9f2015-04-22 16:42:35 -0400981 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000982 r = __discard(cmd, dblock, discard);
Joe Thornber028ae9f2015-04-22 16:42:35 -0400983 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000984
985 return r;
986}
987
988static int __load_discards(struct dm_cache_metadata *cmd,
989 load_discard_fn fn, void *context)
990{
991 int r = 0;
992 dm_block_t b;
993 bool discard;
994
Joe Thornber1bad9bc2014-11-07 14:47:07 +0000995 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
996 dm_dblock_t dblock = to_dblock(b);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +0000997
998 if (cmd->clean_when_opened) {
999 r = __is_discarded(cmd, dblock, &discard);
1000 if (r)
1001 return r;
1002 } else
1003 discard = false;
1004
1005 r = fn(context, cmd->discard_block_size, dblock, discard);
1006 if (r)
1007 break;
1008 }
1009
1010 return r;
1011}
1012
1013int dm_cache_load_discards(struct dm_cache_metadata *cmd,
1014 load_discard_fn fn, void *context)
1015{
1016 int r;
1017
1018 down_read(&cmd->root_lock);
1019 r = __load_discards(cmd, fn, context);
1020 up_read(&cmd->root_lock);
1021
1022 return r;
1023}
1024
1025dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd)
1026{
1027 dm_cblock_t r;
1028
1029 down_read(&cmd->root_lock);
1030 r = cmd->cache_blocks;
1031 up_read(&cmd->root_lock);
1032
1033 return r;
1034}
1035
1036static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1037{
1038 int r;
1039 __le64 value = pack_value(0, 0);
1040
1041 __dm_bless_for_disk(&value);
1042 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1043 &value, &cmd->root);
1044 if (r)
1045 return r;
1046
1047 cmd->changed = true;
1048 return 0;
1049}
1050
1051int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
1052{
1053 int r;
1054
Joe Thornber028ae9f2015-04-22 16:42:35 -04001055 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001056 r = __remove(cmd, cblock);
Joe Thornber028ae9f2015-04-22 16:42:35 -04001057 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001058
1059 return r;
1060}
1061
1062static int __insert(struct dm_cache_metadata *cmd,
1063 dm_cblock_t cblock, dm_oblock_t oblock)
1064{
1065 int r;
1066 __le64 value = pack_value(oblock, M_VALID);
1067 __dm_bless_for_disk(&value);
1068
1069 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1070 &value, &cmd->root);
1071 if (r)
1072 return r;
1073
1074 cmd->changed = true;
1075 return 0;
1076}
1077
1078int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
1079 dm_cblock_t cblock, dm_oblock_t oblock)
1080{
1081 int r;
1082
Joe Thornber028ae9f2015-04-22 16:42:35 -04001083 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001084 r = __insert(cmd, cblock, oblock);
Joe Thornber028ae9f2015-04-22 16:42:35 -04001085 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001086
1087 return r;
1088}
1089
1090struct thunk {
1091 load_mapping_fn fn;
1092 void *context;
1093
1094 struct dm_cache_metadata *cmd;
1095 bool respect_dirty_flags;
1096 bool hints_valid;
1097};
1098
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001099static bool policy_unchanged(struct dm_cache_metadata *cmd,
1100 struct dm_cache_policy *policy)
1101{
1102 const char *policy_name = dm_cache_policy_get_name(policy);
1103 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1104 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
1105
1106 /*
1107 * Ensure policy names match.
1108 */
1109 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
1110 return false;
1111
1112 /*
1113 * Ensure policy major versions match.
1114 */
1115 if (cmd->policy_version[0] != policy_version[0])
1116 return false;
1117
1118 /*
1119 * Ensure policy hint sizes match.
1120 */
1121 if (cmd->policy_hint_size != policy_hint_size)
1122 return false;
1123
1124 return true;
1125}
1126
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001127static bool hints_array_initialized(struct dm_cache_metadata *cmd)
1128{
1129 return cmd->hint_root && cmd->policy_hint_size;
1130}
1131
1132static bool hints_array_available(struct dm_cache_metadata *cmd,
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001133 struct dm_cache_policy *policy)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001134{
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001135 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001136 hints_array_initialized(cmd);
1137}
1138
1139static int __load_mapping(void *context, uint64_t cblock, void *leaf)
1140{
1141 int r = 0;
1142 bool dirty;
1143 __le64 value;
1144 __le32 hint_value = 0;
1145 dm_oblock_t oblock;
1146 unsigned flags;
1147 struct thunk *thunk = context;
1148 struct dm_cache_metadata *cmd = thunk->cmd;
1149
1150 memcpy(&value, leaf, sizeof(value));
1151 unpack_value(value, &oblock, &flags);
1152
1153 if (flags & M_VALID) {
1154 if (thunk->hints_valid) {
1155 r = dm_array_get_value(&cmd->hint_info, cmd->hint_root,
1156 cblock, &hint_value);
1157 if (r && r != -ENODATA)
1158 return r;
1159 }
1160
1161 dirty = thunk->respect_dirty_flags ? (flags & M_DIRTY) : true;
1162 r = thunk->fn(thunk->context, oblock, to_cblock(cblock),
1163 dirty, le32_to_cpu(hint_value), thunk->hints_valid);
1164 }
1165
1166 return r;
1167}
1168
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001169static int __load_mappings(struct dm_cache_metadata *cmd,
1170 struct dm_cache_policy *policy,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001171 load_mapping_fn fn, void *context)
1172{
1173 struct thunk thunk;
1174
1175 thunk.fn = fn;
1176 thunk.context = context;
1177
1178 thunk.cmd = cmd;
1179 thunk.respect_dirty_flags = cmd->clean_when_opened;
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001180 thunk.hints_valid = hints_array_available(cmd, policy);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001181
1182 return dm_array_walk(&cmd->info, cmd->root, __load_mapping, &thunk);
1183}
1184
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001185int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
1186 struct dm_cache_policy *policy,
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001187 load_mapping_fn fn, void *context)
1188{
1189 int r;
1190
1191 down_read(&cmd->root_lock);
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001192 r = __load_mappings(cmd, policy, fn, context);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001193 up_read(&cmd->root_lock);
1194
1195 return r;
1196}
1197
1198static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
1199{
1200 int r = 0;
1201 __le64 value;
1202 dm_oblock_t oblock;
1203 unsigned flags;
1204
1205 memcpy(&value, leaf, sizeof(value));
1206 unpack_value(value, &oblock, &flags);
1207
1208 return r;
1209}
1210
1211static int __dump_mappings(struct dm_cache_metadata *cmd)
1212{
1213 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
1214}
1215
1216void dm_cache_dump(struct dm_cache_metadata *cmd)
1217{
1218 down_read(&cmd->root_lock);
1219 __dump_mappings(cmd);
1220 up_read(&cmd->root_lock);
1221}
1222
1223int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1224{
1225 int r;
1226
1227 down_read(&cmd->root_lock);
1228 r = cmd->changed;
1229 up_read(&cmd->root_lock);
1230
1231 return r;
1232}
1233
1234static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1235{
1236 int r;
1237 unsigned flags;
1238 dm_oblock_t oblock;
1239 __le64 value;
1240
1241 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1242 if (r)
1243 return r;
1244
1245 unpack_value(value, &oblock, &flags);
1246
1247 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1248 /* nothing to be done */
1249 return 0;
1250
Joe Thornber79ed9ca2013-03-20 17:21:27 +00001251 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001252 __dm_bless_for_disk(&value);
1253
1254 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1255 &value, &cmd->root);
1256 if (r)
1257 return r;
1258
1259 cmd->changed = true;
1260 return 0;
1261
1262}
1263
1264int dm_cache_set_dirty(struct dm_cache_metadata *cmd,
1265 dm_cblock_t cblock, bool dirty)
1266{
1267 int r;
1268
Joe Thornber028ae9f2015-04-22 16:42:35 -04001269 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001270 r = __dirty(cmd, cblock, dirty);
Joe Thornber028ae9f2015-04-22 16:42:35 -04001271 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001272
1273 return r;
1274}
1275
1276void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1277 struct dm_cache_statistics *stats)
1278{
1279 down_read(&cmd->root_lock);
Joe Thornber8c5008f2013-05-10 14:37:18 +01001280 *stats = cmd->stats;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001281 up_read(&cmd->root_lock);
1282}
1283
1284void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1285 struct dm_cache_statistics *stats)
1286{
Joe Thornber028ae9f2015-04-22 16:42:35 -04001287 WRITE_LOCK_VOID(cmd);
Joe Thornber8c5008f2013-05-10 14:37:18 +01001288 cmd->stats = *stats;
Joe Thornber028ae9f2015-04-22 16:42:35 -04001289 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001290}
1291
1292int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1293{
1294 int r;
1295 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1296 clear_clean_shutdown);
1297
Joe Thornber028ae9f2015-04-22 16:42:35 -04001298 WRITE_LOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001299 r = __commit_transaction(cmd, mutator);
1300 if (r)
1301 goto out;
1302
1303 r = __begin_transaction(cmd);
1304
1305out:
Joe Thornber028ae9f2015-04-22 16:42:35 -04001306 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001307 return r;
1308}
1309
1310int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1311 dm_block_t *result)
1312{
1313 int r = -EINVAL;
1314
1315 down_read(&cmd->root_lock);
1316 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1317 up_read(&cmd->root_lock);
1318
1319 return r;
1320}
1321
1322int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1323 dm_block_t *result)
1324{
1325 int r = -EINVAL;
1326
1327 down_read(&cmd->root_lock);
1328 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1329 up_read(&cmd->root_lock);
1330
1331 return r;
1332}
1333
1334/*----------------------------------------------------------------*/
1335
1336static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1337{
1338 int r;
1339 __le32 value;
1340 size_t hint_size;
1341 const char *policy_name = dm_cache_policy_get_name(policy);
Mike Snitzer4e7f5062013-03-20 17:21:27 +00001342 const unsigned *policy_version = dm_cache_policy_get_version(policy);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001343
1344 if (!policy_name[0] ||
1345 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1346 return -EINVAL;
1347
Mike Snitzerea2dd8c2013-03-20 17:21:28 +00001348 if (!policy_unchanged(cmd, policy)) {
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001349 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
Mike Snitzer4e7f5062013-03-20 17:21:27 +00001350 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001351
1352 hint_size = dm_cache_policy_get_hint_size(policy);
1353 if (!hint_size)
1354 return 0; /* short-circuit hints initialization */
1355 cmd->policy_hint_size = hint_size;
1356
1357 if (cmd->hint_root) {
1358 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1359 if (r)
1360 return r;
1361 }
1362
1363 r = dm_array_empty(&cmd->hint_info, &cmd->hint_root);
1364 if (r)
1365 return r;
1366
1367 value = cpu_to_le32(0);
1368 __dm_bless_for_disk(&value);
1369 r = dm_array_resize(&cmd->hint_info, cmd->hint_root, 0,
1370 from_cblock(cmd->cache_blocks),
1371 &value, &cmd->hint_root);
1372 if (r)
1373 return r;
1374 }
1375
1376 return 0;
1377}
1378
Joe Thornber05966612014-04-03 16:16:44 +01001379static int save_hint(void *context, dm_cblock_t cblock, dm_oblock_t oblock, uint32_t hint)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001380{
Joe Thornber05966612014-04-03 16:16:44 +01001381 struct dm_cache_metadata *cmd = context;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001382 __le32 value = cpu_to_le32(hint);
Joe Thornber05966612014-04-03 16:16:44 +01001383 int r;
1384
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001385 __dm_bless_for_disk(&value);
1386
1387 r = dm_array_set_value(&cmd->hint_info, cmd->hint_root,
1388 from_cblock(cblock), &value, &cmd->hint_root);
1389 cmd->changed = true;
1390
1391 return r;
1392}
1393
Joe Thornber05966612014-04-03 16:16:44 +01001394static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001395{
1396 int r;
1397
Joe Thornber05966612014-04-03 16:16:44 +01001398 r = begin_hints(cmd, policy);
1399 if (r) {
1400 DMERR("begin_hints failed");
1401 return r;
1402 }
1403
1404 return policy_walk_mappings(policy, save_hint, cmd);
1405}
1406
1407int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1408{
1409 int r;
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001410
Joe Thornber028ae9f2015-04-22 16:42:35 -04001411 WRITE_LOCK(cmd);
Joe Thornber05966612014-04-03 16:16:44 +01001412 r = write_hints(cmd, policy);
Joe Thornber028ae9f2015-04-22 16:42:35 -04001413 WRITE_UNLOCK(cmd);
Joe Thornberc6b4fcb2013-03-01 22:45:51 +00001414
1415 return r;
1416}
Joe Thornber2ee57d52013-10-24 14:10:29 -04001417
1418int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
1419{
1420 return blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
1421}
Joe Thornber028ae9f2015-04-22 16:42:35 -04001422
1423void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
1424{
1425 WRITE_LOCK_VOID(cmd);
1426 dm_bm_set_read_only(cmd->bm);
1427 WRITE_UNLOCK(cmd);
1428}
1429
1430void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
1431{
1432 WRITE_LOCK_VOID(cmd);
1433 dm_bm_set_read_write(cmd->bm);
1434 WRITE_UNLOCK(cmd);
1435}
1436
1437int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
1438{
1439 int r;
1440 struct dm_block *sblock;
1441 struct cache_disk_superblock *disk_super;
1442
1443 /*
1444 * We ignore fail_io for this function.
1445 */
1446 down_write(&cmd->root_lock);
1447 set_bit(NEEDS_CHECK, &cmd->flags);
1448
1449 r = superblock_lock(cmd, &sblock);
1450 if (r) {
1451 DMERR("couldn't read superblock");
1452 goto out;
1453 }
1454
1455 disk_super = dm_block_data(sblock);
1456 disk_super->flags = cpu_to_le32(cmd->flags);
1457
1458 dm_bm_unlock(sblock);
1459
1460out:
1461 up_write(&cmd->root_lock);
1462 return r;
1463}
1464
1465bool dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd)
1466{
1467 bool needs_check;
1468
1469 down_read(&cmd->root_lock);
1470 needs_check = !!test_bit(NEEDS_CHECK, &cmd->flags);
1471 up_read(&cmd->root_lock);
1472
1473 return needs_check;
1474}
1475
1476int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
1477{
1478 int r;
1479
1480 WRITE_LOCK(cmd);
1481 __destroy_persistent_data_objects(cmd);
1482 r = __create_persistent_data_objects(cmd, false);
1483 if (r)
1484 cmd->fail_io = true;
1485 WRITE_UNLOCK(cmd);
1486
1487 return r;
1488}