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
25 * defines a range of metadata versions that this module can handle.
27 #define MIN_CACHE_VERSION 1
28 #define MAX_CACHE_VERSION 1
30 #define CACHE_METADATA_CACHE_SIZE 64
33 * 3 for btree insert +
34 * 2 for btree lookup used within space map
36 #define CACHE_MAX_CONCURRENT_LOCKS 5
37 #define SPACE_MAP_ROOT_SIZE 128
39 enum superblock_flag_bits {
40 /* for spotting crashes that would invalidate the dirty bitset */
45 * Each mapping from cache block -> origin block carries a set of flags.
49 * A valid mapping. Because we're using an array we clear this
50 * flag for an non existant mapping.
55 * The data on the cache is different from that on the origin.
60 struct cache_disk_superblock {
69 __u8 policy_name[CACHE_POLICY_NAME_SIZE];
70 __le32 policy_hint_size;
72 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
77 __le64 discard_block_size;
78 __le64 discard_nr_blocks;
80 __le32 data_block_size;
81 __le32 metadata_block_size;
85 __le32 compat_ro_flags;
86 __le32 incompat_flags;
93 __le32 policy_version[CACHE_POLICY_VERSION_SIZE];
96 struct dm_cache_metadata {
97 struct block_device *bdev;
98 struct dm_block_manager *bm;
99 struct dm_space_map *metadata_sm;
100 struct dm_transaction_manager *tm;
102 struct dm_array_info info;
103 struct dm_array_info hint_info;
104 struct dm_disk_bitset discard_info;
106 struct rw_semaphore root_lock;
108 dm_block_t hint_root;
109 dm_block_t discard_root;
111 sector_t discard_block_size;
112 dm_oblock_t discard_nr_blocks;
114 sector_t data_block_size;
115 dm_cblock_t cache_blocks;
117 bool clean_when_opened:1;
119 char policy_name[CACHE_POLICY_NAME_SIZE];
120 unsigned policy_version[CACHE_POLICY_VERSION_SIZE];
121 size_t policy_hint_size;
122 struct dm_cache_statistics stats;
125 * Reading the space map root can fail, so we read it into this
126 * buffer before the superblock is locked and updated.
128 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
131 /*-------------------------------------------------------------------
132 * superblock validator
133 *-----------------------------------------------------------------*/
135 #define SUPERBLOCK_CSUM_XOR 9031977
137 static void sb_prepare_for_write(struct dm_block_validator *v,
139 size_t sb_block_size)
141 struct cache_disk_superblock *disk_super = dm_block_data(b);
143 disk_super->blocknr = cpu_to_le64(dm_block_location(b));
144 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
145 sb_block_size - sizeof(__le32),
146 SUPERBLOCK_CSUM_XOR));
149 static int check_metadata_version(struct cache_disk_superblock *disk_super)
151 uint32_t metadata_version = le32_to_cpu(disk_super->version);
152 if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) {
153 DMERR("Cache metadata version %u found, but only versions between %u and %u supported.",
154 metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION);
161 static int sb_check(struct dm_block_validator *v,
163 size_t sb_block_size)
165 struct cache_disk_superblock *disk_super = dm_block_data(b);
168 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
169 DMERR("sb_check failed: blocknr %llu: wanted %llu",
170 le64_to_cpu(disk_super->blocknr),
171 (unsigned long long)dm_block_location(b));
175 if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) {
176 DMERR("sb_check failed: magic %llu: wanted %llu",
177 le64_to_cpu(disk_super->magic),
178 (unsigned long long)CACHE_SUPERBLOCK_MAGIC);
182 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
183 sb_block_size - sizeof(__le32),
184 SUPERBLOCK_CSUM_XOR));
185 if (csum_le != disk_super->csum) {
186 DMERR("sb_check failed: csum %u: wanted %u",
187 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
191 return check_metadata_version(disk_super);
194 static struct dm_block_validator sb_validator = {
195 .name = "superblock",
196 .prepare_for_write = sb_prepare_for_write,
200 /*----------------------------------------------------------------*/
202 static int superblock_read_lock(struct dm_cache_metadata *cmd,
203 struct dm_block **sblock)
205 return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
206 &sb_validator, sblock);
209 static int superblock_lock_zero(struct dm_cache_metadata *cmd,
210 struct dm_block **sblock)
212 return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
213 &sb_validator, sblock);
216 static int superblock_lock(struct dm_cache_metadata *cmd,
217 struct dm_block **sblock)
219 return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
220 &sb_validator, sblock);
223 /*----------------------------------------------------------------*/
225 static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
230 __le64 *data_le, zero = cpu_to_le64(0);
231 unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
234 * We can't use a validator here - it may be all zeroes.
236 r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b);
240 data_le = dm_block_data(b);
242 for (i = 0; i < sb_block_size; i++) {
243 if (data_le[i] != zero) {
249 return dm_bm_unlock(b);
252 static void __setup_mapping_info(struct dm_cache_metadata *cmd)
254 struct dm_btree_value_type vt;
257 vt.size = sizeof(__le64);
261 dm_array_info_init(&cmd->info, cmd->tm, &vt);
263 if (cmd->policy_hint_size) {
264 vt.size = sizeof(__le32);
265 dm_array_info_init(&cmd->hint_info, cmd->tm, &vt);
269 static int __save_sm_root(struct dm_cache_metadata *cmd)
274 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
278 return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
282 static void __copy_sm_root(struct dm_cache_metadata *cmd,
283 struct cache_disk_superblock *disk_super)
285 memcpy(&disk_super->metadata_space_map_root,
286 &cmd->metadata_space_map_root,
287 sizeof(cmd->metadata_space_map_root));
290 static int __write_initial_superblock(struct dm_cache_metadata *cmd)
293 struct dm_block *sblock;
294 struct cache_disk_superblock *disk_super;
295 sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
297 /* FIXME: see if we can lose the max sectors limit */
298 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
299 bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
301 r = dm_tm_pre_commit(cmd->tm);
306 * dm_sm_copy_root() can fail. So we need to do it before we start
307 * updating the superblock.
309 r = __save_sm_root(cmd);
313 r = superblock_lock_zero(cmd, &sblock);
317 disk_super = dm_block_data(sblock);
318 disk_super->flags = 0;
319 memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
320 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
321 disk_super->version = cpu_to_le32(MAX_CACHE_VERSION);
322 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
323 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
324 disk_super->policy_hint_size = 0;
326 __copy_sm_root(cmd, disk_super);
328 disk_super->mapping_root = cpu_to_le64(cmd->root);
329 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
330 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
331 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
332 disk_super->discard_nr_blocks = cpu_to_le64(from_oblock(cmd->discard_nr_blocks));
333 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
334 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
335 disk_super->cache_blocks = cpu_to_le32(0);
337 disk_super->read_hits = cpu_to_le32(0);
338 disk_super->read_misses = cpu_to_le32(0);
339 disk_super->write_hits = cpu_to_le32(0);
340 disk_super->write_misses = cpu_to_le32(0);
342 return dm_tm_commit(cmd->tm, sblock);
345 static int __format_metadata(struct dm_cache_metadata *cmd)
349 r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
350 &cmd->tm, &cmd->metadata_sm);
352 DMERR("tm_create_with_sm failed");
356 __setup_mapping_info(cmd);
358 r = dm_array_empty(&cmd->info, &cmd->root);
362 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
364 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root);
368 cmd->discard_block_size = 0;
369 cmd->discard_nr_blocks = 0;
371 r = __write_initial_superblock(cmd);
375 cmd->clean_when_opened = true;
379 dm_tm_destroy(cmd->tm);
380 dm_sm_destroy(cmd->metadata_sm);
385 static int __check_incompat_features(struct cache_disk_superblock *disk_super,
386 struct dm_cache_metadata *cmd)
390 features = le32_to_cpu(disk_super->incompat_flags) & ~DM_CACHE_FEATURE_INCOMPAT_SUPP;
392 DMERR("could not access metadata due to unsupported optional features (%lx).",
393 (unsigned long)features);
398 * Check for read-only metadata to skip the following RDWR checks.
400 if (get_disk_ro(cmd->bdev->bd_disk))
403 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP;
405 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
406 (unsigned long)features);
413 static int __open_metadata(struct dm_cache_metadata *cmd)
416 struct dm_block *sblock;
417 struct cache_disk_superblock *disk_super;
418 unsigned long sb_flags;
420 r = superblock_read_lock(cmd, &sblock);
422 DMERR("couldn't read lock superblock");
426 disk_super = dm_block_data(sblock);
428 r = __check_incompat_features(disk_super, cmd);
432 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
433 disk_super->metadata_space_map_root,
434 sizeof(disk_super->metadata_space_map_root),
435 &cmd->tm, &cmd->metadata_sm);
437 DMERR("tm_open_with_sm failed");
441 __setup_mapping_info(cmd);
442 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
443 sb_flags = le32_to_cpu(disk_super->flags);
444 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
445 return dm_bm_unlock(sblock);
448 dm_bm_unlock(sblock);
452 static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
456 bool unformatted = false;
458 r = __superblock_all_zeroes(cmd->bm, &unformatted);
463 return format_device ? __format_metadata(cmd) : -EPERM;
465 return __open_metadata(cmd);
468 static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
469 bool may_format_device)
472 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE,
473 CACHE_METADATA_CACHE_SIZE,
474 CACHE_MAX_CONCURRENT_LOCKS);
475 if (IS_ERR(cmd->bm)) {
476 DMERR("could not create block manager");
477 return PTR_ERR(cmd->bm);
480 r = __open_or_format_metadata(cmd, may_format_device);
482 dm_block_manager_destroy(cmd->bm);
487 static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd)
489 dm_sm_destroy(cmd->metadata_sm);
490 dm_tm_destroy(cmd->tm);
491 dm_block_manager_destroy(cmd->bm);
494 typedef unsigned long (*flags_mutator)(unsigned long);
496 static void update_flags(struct cache_disk_superblock *disk_super,
497 flags_mutator mutator)
499 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
500 disk_super->flags = cpu_to_le32(sb_flags);
503 static unsigned long set_clean_shutdown(unsigned long flags)
505 set_bit(CLEAN_SHUTDOWN, &flags);
509 static unsigned long clear_clean_shutdown(unsigned long flags)
511 clear_bit(CLEAN_SHUTDOWN, &flags);
515 static void read_superblock_fields(struct dm_cache_metadata *cmd,
516 struct cache_disk_superblock *disk_super)
518 cmd->root = le64_to_cpu(disk_super->mapping_root);
519 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
520 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
521 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
522 cmd->discard_nr_blocks = to_oblock(le64_to_cpu(disk_super->discard_nr_blocks));
523 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
524 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
525 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
526 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
527 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
528 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
529 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
531 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
532 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
533 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
534 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
536 cmd->changed = false;
540 * The mutator updates the superblock flags.
542 static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
543 flags_mutator mutator)
546 struct cache_disk_superblock *disk_super;
547 struct dm_block *sblock;
549 r = superblock_lock(cmd, &sblock);
553 disk_super = dm_block_data(sblock);
554 update_flags(disk_super, mutator);
555 read_superblock_fields(cmd, disk_super);
556 dm_bm_unlock(sblock);
558 return dm_bm_flush(cmd->bm);
561 static int __begin_transaction(struct dm_cache_metadata *cmd)
564 struct cache_disk_superblock *disk_super;
565 struct dm_block *sblock;
568 * We re-read the superblock every time. Shouldn't need to do this
571 r = superblock_read_lock(cmd, &sblock);
575 disk_super = dm_block_data(sblock);
576 read_superblock_fields(cmd, disk_super);
577 dm_bm_unlock(sblock);
582 static int __commit_transaction(struct dm_cache_metadata *cmd,
583 flags_mutator mutator)
586 struct cache_disk_superblock *disk_super;
587 struct dm_block *sblock;
590 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
592 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
594 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
599 r = dm_tm_pre_commit(cmd->tm);
603 r = __save_sm_root(cmd);
607 r = superblock_lock(cmd, &sblock);
611 disk_super = dm_block_data(sblock);
614 update_flags(disk_super, mutator);
616 disk_super->mapping_root = cpu_to_le64(cmd->root);
617 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
618 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
619 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
620 disk_super->discard_nr_blocks = cpu_to_le64(from_oblock(cmd->discard_nr_blocks));
621 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
622 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
623 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
624 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
625 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
627 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
628 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
629 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
630 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
631 __copy_sm_root(cmd, disk_super);
633 return dm_tm_commit(cmd->tm, sblock);
636 /*----------------------------------------------------------------*/
639 * The mappings are held in a dm-array that has 64-bit values stored in
640 * little-endian format. The index is the cblock, the high 48bits of the
641 * value are the oblock and the low 16 bit the flags.
643 #define FLAGS_MASK ((1 << 16) - 1)
645 static __le64 pack_value(dm_oblock_t block, unsigned flags)
647 uint64_t value = from_oblock(block);
649 value = value | (flags & FLAGS_MASK);
650 return cpu_to_le64(value);
653 static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
655 uint64_t value = le64_to_cpu(value_le);
656 uint64_t b = value >> 16;
657 *block = to_oblock(b);
658 *flags = value & FLAGS_MASK;
661 /*----------------------------------------------------------------*/
663 struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
664 sector_t data_block_size,
665 bool may_format_device,
666 size_t policy_hint_size)
669 struct dm_cache_metadata *cmd;
671 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
673 DMERR("could not allocate metadata struct");
677 init_rwsem(&cmd->root_lock);
679 cmd->data_block_size = data_block_size;
680 cmd->cache_blocks = 0;
681 cmd->policy_hint_size = policy_hint_size;
684 r = __create_persistent_data_objects(cmd, may_format_device);
690 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
692 dm_cache_metadata_close(cmd);
699 void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
701 __destroy_persistent_data_objects(cmd);
706 * Checks that the given cache block is either unmapped or clean.
708 static int block_unmapped_or_clean(struct dm_cache_metadata *cmd, dm_cblock_t b,
716 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
718 DMERR("block_unmapped_or_clean failed");
722 unpack_value(value, &ob, &flags);
723 *result = !((flags & M_VALID) && (flags & M_DIRTY));
728 static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
729 dm_cblock_t begin, dm_cblock_t end,
735 while (begin != end) {
736 r = block_unmapped_or_clean(cmd, begin, result);
741 DMERR("cache block %llu is dirty",
742 (unsigned long long) from_cblock(begin));
746 begin = to_cblock(from_cblock(begin) + 1);
752 int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
756 __le64 null_mapping = pack_value(0, 0);
758 down_write(&cmd->root_lock);
759 __dm_bless_for_disk(&null_mapping);
761 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
762 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
764 __dm_unbless_for_disk(&null_mapping);
769 DMERR("unable to shrink cache due to dirty blocks");
771 __dm_unbless_for_disk(&null_mapping);
776 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
777 from_cblock(new_cache_size),
778 &null_mapping, &cmd->root);
780 cmd->cache_blocks = new_cache_size;
784 up_write(&cmd->root_lock);
789 int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
790 sector_t discard_block_size,
791 dm_oblock_t new_nr_entries)
795 down_write(&cmd->root_lock);
796 r = dm_bitset_resize(&cmd->discard_info,
798 from_oblock(cmd->discard_nr_blocks),
799 from_oblock(new_nr_entries),
800 false, &cmd->discard_root);
802 cmd->discard_block_size = discard_block_size;
803 cmd->discard_nr_blocks = new_nr_entries;
807 up_write(&cmd->root_lock);
812 static int __set_discard(struct dm_cache_metadata *cmd, dm_oblock_t b)
814 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
815 from_oblock(b), &cmd->discard_root);
818 static int __clear_discard(struct dm_cache_metadata *cmd, dm_oblock_t b)
820 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
821 from_oblock(b), &cmd->discard_root);
824 static int __is_discarded(struct dm_cache_metadata *cmd, dm_oblock_t b,
827 return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root,
828 from_oblock(b), &cmd->discard_root,
832 static int __discard(struct dm_cache_metadata *cmd,
833 dm_oblock_t dblock, bool discard)
837 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
845 int dm_cache_set_discard(struct dm_cache_metadata *cmd,
846 dm_oblock_t dblock, bool discard)
850 down_write(&cmd->root_lock);
851 r = __discard(cmd, dblock, discard);
852 up_write(&cmd->root_lock);
857 static int __load_discards(struct dm_cache_metadata *cmd,
858 load_discard_fn fn, void *context)
864 for (b = 0; b < from_oblock(cmd->discard_nr_blocks); b++) {
865 dm_oblock_t dblock = to_oblock(b);
867 if (cmd->clean_when_opened) {
868 r = __is_discarded(cmd, dblock, &discard);
874 r = fn(context, cmd->discard_block_size, dblock, discard);
882 int dm_cache_load_discards(struct dm_cache_metadata *cmd,
883 load_discard_fn fn, void *context)
887 down_read(&cmd->root_lock);
888 r = __load_discards(cmd, fn, context);
889 up_read(&cmd->root_lock);
894 dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd)
898 down_read(&cmd->root_lock);
899 r = cmd->cache_blocks;
900 up_read(&cmd->root_lock);
905 static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
908 __le64 value = pack_value(0, 0);
910 __dm_bless_for_disk(&value);
911 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
920 int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
924 down_write(&cmd->root_lock);
925 r = __remove(cmd, cblock);
926 up_write(&cmd->root_lock);
931 static int __insert(struct dm_cache_metadata *cmd,
932 dm_cblock_t cblock, dm_oblock_t oblock)
935 __le64 value = pack_value(oblock, M_VALID);
936 __dm_bless_for_disk(&value);
938 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
947 int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
948 dm_cblock_t cblock, dm_oblock_t oblock)
952 down_write(&cmd->root_lock);
953 r = __insert(cmd, cblock, oblock);
954 up_write(&cmd->root_lock);
963 struct dm_cache_metadata *cmd;
964 bool respect_dirty_flags;
968 static bool policy_unchanged(struct dm_cache_metadata *cmd,
969 struct dm_cache_policy *policy)
971 const char *policy_name = dm_cache_policy_get_name(policy);
972 const unsigned *policy_version = dm_cache_policy_get_version(policy);
973 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
976 * Ensure policy names match.
978 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
982 * Ensure policy major versions match.
984 if (cmd->policy_version[0] != policy_version[0])
988 * Ensure policy hint sizes match.
990 if (cmd->policy_hint_size != policy_hint_size)
996 static bool hints_array_initialized(struct dm_cache_metadata *cmd)
998 return cmd->hint_root && cmd->policy_hint_size;
1001 static bool hints_array_available(struct dm_cache_metadata *cmd,
1002 struct dm_cache_policy *policy)
1004 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
1005 hints_array_initialized(cmd);
1008 static int __load_mapping(void *context, uint64_t cblock, void *leaf)
1013 __le32 hint_value = 0;
1016 struct thunk *thunk = context;
1017 struct dm_cache_metadata *cmd = thunk->cmd;
1019 memcpy(&value, leaf, sizeof(value));
1020 unpack_value(value, &oblock, &flags);
1022 if (flags & M_VALID) {
1023 if (thunk->hints_valid) {
1024 r = dm_array_get_value(&cmd->hint_info, cmd->hint_root,
1025 cblock, &hint_value);
1026 if (r && r != -ENODATA)
1030 dirty = thunk->respect_dirty_flags ? (flags & M_DIRTY) : true;
1031 r = thunk->fn(thunk->context, oblock, to_cblock(cblock),
1032 dirty, le32_to_cpu(hint_value), thunk->hints_valid);
1038 static int __load_mappings(struct dm_cache_metadata *cmd,
1039 struct dm_cache_policy *policy,
1040 load_mapping_fn fn, void *context)
1045 thunk.context = context;
1048 thunk.respect_dirty_flags = cmd->clean_when_opened;
1049 thunk.hints_valid = hints_array_available(cmd, policy);
1051 return dm_array_walk(&cmd->info, cmd->root, __load_mapping, &thunk);
1054 int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
1055 struct dm_cache_policy *policy,
1056 load_mapping_fn fn, void *context)
1060 down_read(&cmd->root_lock);
1061 r = __load_mappings(cmd, policy, fn, context);
1062 up_read(&cmd->root_lock);
1067 static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
1074 memcpy(&value, leaf, sizeof(value));
1075 unpack_value(value, &oblock, &flags);
1080 static int __dump_mappings(struct dm_cache_metadata *cmd)
1082 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
1085 void dm_cache_dump(struct dm_cache_metadata *cmd)
1087 down_read(&cmd->root_lock);
1088 __dump_mappings(cmd);
1089 up_read(&cmd->root_lock);
1092 int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1096 down_read(&cmd->root_lock);
1098 up_read(&cmd->root_lock);
1103 static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1110 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1114 unpack_value(value, &oblock, &flags);
1116 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1117 /* nothing to be done */
1120 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
1121 __dm_bless_for_disk(&value);
1123 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1124 &value, &cmd->root);
1128 cmd->changed = true;
1133 int dm_cache_set_dirty(struct dm_cache_metadata *cmd,
1134 dm_cblock_t cblock, bool dirty)
1138 down_write(&cmd->root_lock);
1139 r = __dirty(cmd, cblock, dirty);
1140 up_write(&cmd->root_lock);
1145 void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1146 struct dm_cache_statistics *stats)
1148 down_read(&cmd->root_lock);
1149 *stats = cmd->stats;
1150 up_read(&cmd->root_lock);
1153 void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1154 struct dm_cache_statistics *stats)
1156 down_write(&cmd->root_lock);
1157 cmd->stats = *stats;
1158 up_write(&cmd->root_lock);
1161 int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1164 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1165 clear_clean_shutdown);
1167 down_write(&cmd->root_lock);
1168 r = __commit_transaction(cmd, mutator);
1172 r = __begin_transaction(cmd);
1175 up_write(&cmd->root_lock);
1179 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1184 down_read(&cmd->root_lock);
1185 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1186 up_read(&cmd->root_lock);
1191 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1196 down_read(&cmd->root_lock);
1197 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1198 up_read(&cmd->root_lock);
1203 /*----------------------------------------------------------------*/
1205 static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1210 const char *policy_name = dm_cache_policy_get_name(policy);
1211 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1213 if (!policy_name[0] ||
1214 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1217 if (!policy_unchanged(cmd, policy)) {
1218 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
1219 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
1221 hint_size = dm_cache_policy_get_hint_size(policy);
1223 return 0; /* short-circuit hints initialization */
1224 cmd->policy_hint_size = hint_size;
1226 if (cmd->hint_root) {
1227 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1232 r = dm_array_empty(&cmd->hint_info, &cmd->hint_root);
1236 value = cpu_to_le32(0);
1237 __dm_bless_for_disk(&value);
1238 r = dm_array_resize(&cmd->hint_info, cmd->hint_root, 0,
1239 from_cblock(cmd->cache_blocks),
1240 &value, &cmd->hint_root);
1248 static int save_hint(void *context, dm_cblock_t cblock, dm_oblock_t oblock, uint32_t hint)
1250 struct dm_cache_metadata *cmd = context;
1251 __le32 value = cpu_to_le32(hint);
1254 __dm_bless_for_disk(&value);
1256 r = dm_array_set_value(&cmd->hint_info, cmd->hint_root,
1257 from_cblock(cblock), &value, &cmd->hint_root);
1258 cmd->changed = true;
1263 static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1267 r = begin_hints(cmd, policy);
1269 DMERR("begin_hints failed");
1273 return policy_walk_mappings(policy, save_hint, cmd);
1276 int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1280 down_write(&cmd->root_lock);
1281 r = write_hints(cmd, policy);
1282 up_write(&cmd->root_lock);
1287 int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
1289 return blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);