2 * Copyright (C) 2012 Red Hat, Inc.
4 * This file is released under the GPL.
7 #include "dm-cache-metadata.h"
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"
15 #include <linux/device-mapper.h>
17 /*----------------------------------------------------------------*/
19 #define DM_MSG_PREFIX "cache metadata"
21 #define CACHE_SUPERBLOCK_MAGIC 06142003
22 #define CACHE_SUPERBLOCK_LOCATION 0
23 #define CACHE_VERSION 1
24 #define CACHE_METADATA_CACHE_SIZE 64
27 * 3 for btree insert +
28 * 2 for btree lookup used within space map
30 #define CACHE_MAX_CONCURRENT_LOCKS 5
31 #define SPACE_MAP_ROOT_SIZE 128
33 enum superblock_flag_bits {
34 /* for spotting crashes that would invalidate the dirty bitset */
39 * Each mapping from cache block -> origin block carries a set of flags.
43 * A valid mapping. Because we're using an array we clear this
44 * flag for an non existant mapping.
49 * The data on the cache is different from that on the origin.
54 struct cache_disk_superblock {
63 __u8 policy_name[CACHE_POLICY_NAME_SIZE];
64 __le32 policy_hint_size;
66 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
71 __le64 discard_block_size;
72 __le64 discard_nr_blocks;
74 __le32 data_block_size;
75 __le32 metadata_block_size;
79 __le32 compat_ro_flags;
80 __le32 incompat_flags;
87 __le32 policy_version[CACHE_POLICY_VERSION_SIZE];
90 struct dm_cache_metadata {
91 struct block_device *bdev;
92 struct dm_block_manager *bm;
93 struct dm_space_map *metadata_sm;
94 struct dm_transaction_manager *tm;
96 struct dm_array_info info;
97 struct dm_array_info hint_info;
98 struct dm_disk_bitset discard_info;
100 struct rw_semaphore root_lock;
102 dm_block_t hint_root;
103 dm_block_t discard_root;
105 sector_t discard_block_size;
106 dm_dblock_t discard_nr_blocks;
108 sector_t data_block_size;
109 dm_cblock_t cache_blocks;
111 bool clean_when_opened:1;
113 char policy_name[CACHE_POLICY_NAME_SIZE];
114 unsigned policy_version[CACHE_POLICY_VERSION_SIZE];
115 size_t policy_hint_size;
116 struct dm_cache_statistics stats;
119 /*-------------------------------------------------------------------
120 * superblock validator
121 *-----------------------------------------------------------------*/
123 #define SUPERBLOCK_CSUM_XOR 9031977
125 static void sb_prepare_for_write(struct dm_block_validator *v,
127 size_t sb_block_size)
129 struct cache_disk_superblock *disk_super = dm_block_data(b);
131 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
132 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
133 sb_block_size - sizeof(__le32),
134 SUPERBLOCK_CSUM_XOR));
137 static int sb_check(struct dm_block_validator *v,
139 size_t sb_block_size)
141 struct cache_disk_superblock *disk_super = dm_block_data(b);
144 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
145 DMERR("sb_check failed: blocknr %llu: wanted %llu",
146 le64_to_cpu(disk_super->blocknr),
147 (unsigned long long)dm_block_location(b));
151 if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) {
152 DMERR("sb_check failed: magic %llu: wanted %llu",
153 le64_to_cpu(disk_super->magic),
154 (unsigned long long)CACHE_SUPERBLOCK_MAGIC);
158 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
159 sb_block_size - sizeof(__le32),
160 SUPERBLOCK_CSUM_XOR));
161 if (csum_le != disk_super->csum) {
162 DMERR("sb_check failed: csum %u: wanted %u",
163 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
170 static struct dm_block_validator sb_validator = {
171 .name = "superblock",
172 .prepare_for_write = sb_prepare_for_write,
176 /*----------------------------------------------------------------*/
178 static int superblock_read_lock(struct dm_cache_metadata *cmd,
179 struct dm_block **sblock)
181 return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
182 &sb_validator, sblock);
185 static int superblock_lock_zero(struct dm_cache_metadata *cmd,
186 struct dm_block **sblock)
188 return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
189 &sb_validator, sblock);
192 static int superblock_lock(struct dm_cache_metadata *cmd,
193 struct dm_block **sblock)
195 return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
196 &sb_validator, sblock);
199 /*----------------------------------------------------------------*/
201 static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
206 __le64 *data_le, zero = cpu_to_le64(0);
207 unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
210 * We can't use a validator here - it may be all zeroes.
212 r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b);
216 data_le = dm_block_data(b);
218 for (i = 0; i < sb_block_size; i++) {
219 if (data_le[i] != zero) {
225 return dm_bm_unlock(b);
228 static void __setup_mapping_info(struct dm_cache_metadata *cmd)
230 struct dm_btree_value_type vt;
233 vt.size = sizeof(__le64);
237 dm_array_info_init(&cmd->info, cmd->tm, &vt);
239 if (cmd->policy_hint_size) {
240 vt.size = sizeof(__le32);
241 dm_array_info_init(&cmd->hint_info, cmd->tm, &vt);
245 static int __write_initial_superblock(struct dm_cache_metadata *cmd)
248 struct dm_block *sblock;
250 struct cache_disk_superblock *disk_super;
251 sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
253 /* FIXME: see if we can lose the max sectors limit */
254 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
255 bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
257 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
261 r = dm_tm_pre_commit(cmd->tm);
265 r = superblock_lock_zero(cmd, &sblock);
269 disk_super = dm_block_data(sblock);
270 disk_super->flags = 0;
271 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
272 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
273 disk_super->version = cpu_to_le32(CACHE_VERSION);
274 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
275 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
276 disk_super->policy_hint_size = 0;
278 r = dm_sm_copy_root(cmd->metadata_sm, &disk_super->metadata_space_map_root,
283 disk_super->mapping_root = cpu_to_le64(cmd->root);
284 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
285 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
286 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
287 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
288 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
289 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
290 disk_super->cache_blocks = cpu_to_le32(0);
292 disk_super->read_hits = cpu_to_le32(0);
293 disk_super->read_misses = cpu_to_le32(0);
294 disk_super->write_hits = cpu_to_le32(0);
295 disk_super->write_misses = cpu_to_le32(0);
297 return dm_tm_commit(cmd->tm, sblock);
300 dm_bm_unlock(sblock);
304 static int __format_metadata(struct dm_cache_metadata *cmd)
308 r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
309 &cmd->tm, &cmd->metadata_sm);
311 DMERR("tm_create_with_sm failed");
315 __setup_mapping_info(cmd);
317 r = dm_array_empty(&cmd->info, &cmd->root);
321 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
323 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root);
327 cmd->discard_block_size = 0;
328 cmd->discard_nr_blocks = 0;
330 r = __write_initial_superblock(cmd);
334 cmd->clean_when_opened = true;
338 dm_tm_destroy(cmd->tm);
339 dm_sm_destroy(cmd->metadata_sm);
344 static int __check_incompat_features(struct cache_disk_superblock *disk_super,
345 struct dm_cache_metadata *cmd)
349 features = le32_to_cpu(disk_super->incompat_flags) & ~DM_CACHE_FEATURE_INCOMPAT_SUPP;
351 DMERR("could not access metadata due to unsupported optional features (%lx).",
352 (unsigned long)features);
357 * Check for read-only metadata to skip the following RDWR checks.
359 if (get_disk_ro(cmd->bdev->bd_disk))
362 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP;
364 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
365 (unsigned long)features);
372 static int __open_metadata(struct dm_cache_metadata *cmd)
375 struct dm_block *sblock;
376 struct cache_disk_superblock *disk_super;
377 unsigned long sb_flags;
379 r = superblock_read_lock(cmd, &sblock);
381 DMERR("couldn't read lock superblock");
385 disk_super = dm_block_data(sblock);
387 r = __check_incompat_features(disk_super, cmd);
391 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
392 disk_super->metadata_space_map_root,
393 sizeof(disk_super->metadata_space_map_root),
394 &cmd->tm, &cmd->metadata_sm);
396 DMERR("tm_open_with_sm failed");
400 __setup_mapping_info(cmd);
401 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
402 sb_flags = le32_to_cpu(disk_super->flags);
403 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
404 return dm_bm_unlock(sblock);
407 dm_bm_unlock(sblock);
411 static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
416 r = __superblock_all_zeroes(cmd->bm, &unformatted);
421 return format_device ? __format_metadata(cmd) : -EPERM;
423 return __open_metadata(cmd);
426 static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
427 bool may_format_device)
430 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE,
431 CACHE_METADATA_CACHE_SIZE,
432 CACHE_MAX_CONCURRENT_LOCKS);
433 if (IS_ERR(cmd->bm)) {
434 DMERR("could not create block manager");
435 return PTR_ERR(cmd->bm);
438 r = __open_or_format_metadata(cmd, may_format_device);
440 dm_block_manager_destroy(cmd->bm);
445 static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd)
447 dm_sm_destroy(cmd->metadata_sm);
448 dm_tm_destroy(cmd->tm);
449 dm_block_manager_destroy(cmd->bm);
452 typedef unsigned long (*flags_mutator)(unsigned long);
454 static void update_flags(struct cache_disk_superblock *disk_super,
455 flags_mutator mutator)
457 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
458 disk_super->flags = cpu_to_le32(sb_flags);
461 static unsigned long set_clean_shutdown(unsigned long flags)
463 set_bit(CLEAN_SHUTDOWN, &flags);
467 static unsigned long clear_clean_shutdown(unsigned long flags)
469 clear_bit(CLEAN_SHUTDOWN, &flags);
473 static void read_superblock_fields(struct dm_cache_metadata *cmd,
474 struct cache_disk_superblock *disk_super)
476 cmd->root = le64_to_cpu(disk_super->mapping_root);
477 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
478 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
479 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
480 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
481 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
482 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
483 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
484 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
485 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
486 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
487 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
489 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
490 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
491 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
492 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
494 cmd->changed = false;
498 * The mutator updates the superblock flags.
500 static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
501 flags_mutator mutator)
504 struct cache_disk_superblock *disk_super;
505 struct dm_block *sblock;
507 r = superblock_lock(cmd, &sblock);
511 disk_super = dm_block_data(sblock);
512 update_flags(disk_super, mutator);
513 read_superblock_fields(cmd, disk_super);
514 dm_bm_unlock(sblock);
516 return dm_bm_flush(cmd->bm);
519 static int __begin_transaction(struct dm_cache_metadata *cmd)
522 struct cache_disk_superblock *disk_super;
523 struct dm_block *sblock;
526 * We re-read the superblock every time. Shouldn't need to do this
529 r = superblock_read_lock(cmd, &sblock);
533 disk_super = dm_block_data(sblock);
534 read_superblock_fields(cmd, disk_super);
535 dm_bm_unlock(sblock);
540 static int __commit_transaction(struct dm_cache_metadata *cmd,
541 flags_mutator mutator)
545 struct cache_disk_superblock *disk_super;
546 struct dm_block *sblock;
549 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
551 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
553 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
558 r = dm_tm_pre_commit(cmd->tm);
562 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
566 r = superblock_lock(cmd, &sblock);
570 disk_super = dm_block_data(sblock);
573 update_flags(disk_super, mutator);
575 disk_super->mapping_root = cpu_to_le64(cmd->root);
576 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
577 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
578 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
579 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
580 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
581 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
582 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
583 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
584 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
586 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
587 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
588 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
589 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
591 r = dm_sm_copy_root(cmd->metadata_sm, &disk_super->metadata_space_map_root,
594 dm_bm_unlock(sblock);
598 return dm_tm_commit(cmd->tm, sblock);
601 /*----------------------------------------------------------------*/
604 * The mappings are held in a dm-array that has 64-bit values stored in
605 * little-endian format. The index is the cblock, the high 48bits of the
606 * value are the oblock and the low 16 bit the flags.
608 #define FLAGS_MASK ((1 << 16) - 1)
610 static __le64 pack_value(dm_oblock_t block, unsigned flags)
612 uint64_t value = from_oblock(block);
614 value = value | (flags & FLAGS_MASK);
615 return cpu_to_le64(value);
618 static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
620 uint64_t value = le64_to_cpu(value_le);
621 uint64_t b = value >> 16;
622 *block = to_oblock(b);
623 *flags = value & FLAGS_MASK;
626 /*----------------------------------------------------------------*/
628 struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
629 sector_t data_block_size,
630 bool may_format_device,
631 size_t policy_hint_size)
634 struct dm_cache_metadata *cmd;
636 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
638 DMERR("could not allocate metadata struct");
642 init_rwsem(&cmd->root_lock);
644 cmd->data_block_size = data_block_size;
645 cmd->cache_blocks = 0;
646 cmd->policy_hint_size = policy_hint_size;
649 r = __create_persistent_data_objects(cmd, may_format_device);
655 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
657 dm_cache_metadata_close(cmd);
664 void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
666 __destroy_persistent_data_objects(cmd);
670 int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
673 __le64 null_mapping = pack_value(0, 0);
675 down_write(&cmd->root_lock);
676 __dm_bless_for_disk(&null_mapping);
677 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
678 from_cblock(new_cache_size),
679 &null_mapping, &cmd->root);
681 cmd->cache_blocks = new_cache_size;
683 up_write(&cmd->root_lock);
688 int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
689 sector_t discard_block_size,
690 dm_dblock_t new_nr_entries)
694 down_write(&cmd->root_lock);
695 r = dm_bitset_resize(&cmd->discard_info,
697 from_dblock(cmd->discard_nr_blocks),
698 from_dblock(new_nr_entries),
699 false, &cmd->discard_root);
701 cmd->discard_block_size = discard_block_size;
702 cmd->discard_nr_blocks = new_nr_entries;
706 up_write(&cmd->root_lock);
711 static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
713 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
714 from_dblock(b), &cmd->discard_root);
717 static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
719 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
720 from_dblock(b), &cmd->discard_root);
723 static int __is_discarded(struct dm_cache_metadata *cmd, dm_dblock_t b,
726 return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root,
727 from_dblock(b), &cmd->discard_root,
731 static int __discard(struct dm_cache_metadata *cmd,
732 dm_dblock_t dblock, bool discard)
736 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
744 int dm_cache_set_discard(struct dm_cache_metadata *cmd,
745 dm_dblock_t dblock, bool discard)
749 down_write(&cmd->root_lock);
750 r = __discard(cmd, dblock, discard);
751 up_write(&cmd->root_lock);
756 static int __load_discards(struct dm_cache_metadata *cmd,
757 load_discard_fn fn, void *context)
763 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
764 dm_dblock_t dblock = to_dblock(b);
766 if (cmd->clean_when_opened) {
767 r = __is_discarded(cmd, dblock, &discard);
773 r = fn(context, cmd->discard_block_size, dblock, discard);
781 int dm_cache_load_discards(struct dm_cache_metadata *cmd,
782 load_discard_fn fn, void *context)
786 down_read(&cmd->root_lock);
787 r = __load_discards(cmd, fn, context);
788 up_read(&cmd->root_lock);
793 dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd)
797 down_read(&cmd->root_lock);
798 r = cmd->cache_blocks;
799 up_read(&cmd->root_lock);
804 static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
807 __le64 value = pack_value(0, 0);
809 __dm_bless_for_disk(&value);
810 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
819 int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
823 down_write(&cmd->root_lock);
824 r = __remove(cmd, cblock);
825 up_write(&cmd->root_lock);
830 static int __insert(struct dm_cache_metadata *cmd,
831 dm_cblock_t cblock, dm_oblock_t oblock)
834 __le64 value = pack_value(oblock, M_VALID);
835 __dm_bless_for_disk(&value);
837 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
846 int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
847 dm_cblock_t cblock, dm_oblock_t oblock)
851 down_write(&cmd->root_lock);
852 r = __insert(cmd, cblock, oblock);
853 up_write(&cmd->root_lock);
862 struct dm_cache_metadata *cmd;
863 bool respect_dirty_flags;
867 static bool policy_unchanged(struct dm_cache_metadata *cmd,
868 struct dm_cache_policy *policy)
870 const char *policy_name = dm_cache_policy_get_name(policy);
871 const unsigned *policy_version = dm_cache_policy_get_version(policy);
872 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
875 * Ensure policy names match.
877 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
881 * Ensure policy major versions match.
883 if (cmd->policy_version[0] != policy_version[0])
887 * Ensure policy hint sizes match.
889 if (cmd->policy_hint_size != policy_hint_size)
895 static bool hints_array_initialized(struct dm_cache_metadata *cmd)
897 return cmd->hint_root && cmd->policy_hint_size;
900 static bool hints_array_available(struct dm_cache_metadata *cmd,
901 struct dm_cache_policy *policy)
903 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
904 hints_array_initialized(cmd);
907 static int __load_mapping(void *context, uint64_t cblock, void *leaf)
912 __le32 hint_value = 0;
915 struct thunk *thunk = context;
916 struct dm_cache_metadata *cmd = thunk->cmd;
918 memcpy(&value, leaf, sizeof(value));
919 unpack_value(value, &oblock, &flags);
921 if (flags & M_VALID) {
922 if (thunk->hints_valid) {
923 r = dm_array_get_value(&cmd->hint_info, cmd->hint_root,
924 cblock, &hint_value);
925 if (r && r != -ENODATA)
929 dirty = thunk->respect_dirty_flags ? (flags & M_DIRTY) : true;
930 r = thunk->fn(thunk->context, oblock, to_cblock(cblock),
931 dirty, le32_to_cpu(hint_value), thunk->hints_valid);
937 static int __load_mappings(struct dm_cache_metadata *cmd,
938 struct dm_cache_policy *policy,
939 load_mapping_fn fn, void *context)
944 thunk.context = context;
947 thunk.respect_dirty_flags = cmd->clean_when_opened;
948 thunk.hints_valid = hints_array_available(cmd, policy);
950 return dm_array_walk(&cmd->info, cmd->root, __load_mapping, &thunk);
953 int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
954 struct dm_cache_policy *policy,
955 load_mapping_fn fn, void *context)
959 down_read(&cmd->root_lock);
960 r = __load_mappings(cmd, policy, fn, context);
961 up_read(&cmd->root_lock);
966 static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
973 memcpy(&value, leaf, sizeof(value));
974 unpack_value(value, &oblock, &flags);
979 static int __dump_mappings(struct dm_cache_metadata *cmd)
981 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
984 void dm_cache_dump(struct dm_cache_metadata *cmd)
986 down_read(&cmd->root_lock);
987 __dump_mappings(cmd);
988 up_read(&cmd->root_lock);
991 int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
995 down_read(&cmd->root_lock);
997 up_read(&cmd->root_lock);
1002 static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1009 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1013 unpack_value(value, &oblock, &flags);
1015 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1016 /* nothing to be done */
1019 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
1020 __dm_bless_for_disk(&value);
1022 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1023 &value, &cmd->root);
1027 cmd->changed = true;
1032 int dm_cache_set_dirty(struct dm_cache_metadata *cmd,
1033 dm_cblock_t cblock, bool dirty)
1037 down_write(&cmd->root_lock);
1038 r = __dirty(cmd, cblock, dirty);
1039 up_write(&cmd->root_lock);
1044 void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1045 struct dm_cache_statistics *stats)
1047 down_read(&cmd->root_lock);
1048 *stats = cmd->stats;
1049 up_read(&cmd->root_lock);
1052 void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1053 struct dm_cache_statistics *stats)
1055 down_write(&cmd->root_lock);
1056 cmd->stats = *stats;
1057 up_write(&cmd->root_lock);
1060 int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1063 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1064 clear_clean_shutdown);
1066 down_write(&cmd->root_lock);
1067 r = __commit_transaction(cmd, mutator);
1071 r = __begin_transaction(cmd);
1074 up_write(&cmd->root_lock);
1078 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1083 down_read(&cmd->root_lock);
1084 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1085 up_read(&cmd->root_lock);
1090 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1095 down_read(&cmd->root_lock);
1096 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1097 up_read(&cmd->root_lock);
1102 /*----------------------------------------------------------------*/
1104 static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1109 const char *policy_name = dm_cache_policy_get_name(policy);
1110 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1112 if (!policy_name[0] ||
1113 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1116 if (!policy_unchanged(cmd, policy)) {
1117 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
1118 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
1120 hint_size = dm_cache_policy_get_hint_size(policy);
1122 return 0; /* short-circuit hints initialization */
1123 cmd->policy_hint_size = hint_size;
1125 if (cmd->hint_root) {
1126 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1131 r = dm_array_empty(&cmd->hint_info, &cmd->hint_root);
1135 value = cpu_to_le32(0);
1136 __dm_bless_for_disk(&value);
1137 r = dm_array_resize(&cmd->hint_info, cmd->hint_root, 0,
1138 from_cblock(cmd->cache_blocks),
1139 &value, &cmd->hint_root);
1147 int dm_cache_begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1151 down_write(&cmd->root_lock);
1152 r = begin_hints(cmd, policy);
1153 up_write(&cmd->root_lock);
1158 static int save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
1162 __le32 value = cpu_to_le32(hint);
1163 __dm_bless_for_disk(&value);
1165 r = dm_array_set_value(&cmd->hint_info, cmd->hint_root,
1166 from_cblock(cblock), &value, &cmd->hint_root);
1167 cmd->changed = true;
1172 int dm_cache_save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
1177 if (!hints_array_initialized(cmd))
1180 down_write(&cmd->root_lock);
1181 r = save_hint(cmd, cblock, hint);
1182 up_write(&cmd->root_lock);