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 /* Verify the data block size hasn't changed */
388 if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) {
389 DMERR("changing the data block size (from %u to %llu) is not supported",
390 le32_to_cpu(disk_super->data_block_size),
391 (unsigned long long)cmd->data_block_size);
396 r = __check_incompat_features(disk_super, cmd);
400 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION,
401 disk_super->metadata_space_map_root,
402 sizeof(disk_super->metadata_space_map_root),
403 &cmd->tm, &cmd->metadata_sm);
405 DMERR("tm_open_with_sm failed");
409 __setup_mapping_info(cmd);
410 dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
411 sb_flags = le32_to_cpu(disk_super->flags);
412 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
413 return dm_bm_unlock(sblock);
416 dm_bm_unlock(sblock);
420 static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
425 r = __superblock_all_zeroes(cmd->bm, &unformatted);
430 return format_device ? __format_metadata(cmd) : -EPERM;
432 return __open_metadata(cmd);
435 static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
436 bool may_format_device)
439 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE,
440 CACHE_METADATA_CACHE_SIZE,
441 CACHE_MAX_CONCURRENT_LOCKS);
442 if (IS_ERR(cmd->bm)) {
443 DMERR("could not create block manager");
444 return PTR_ERR(cmd->bm);
447 r = __open_or_format_metadata(cmd, may_format_device);
449 dm_block_manager_destroy(cmd->bm);
454 static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd)
456 dm_sm_destroy(cmd->metadata_sm);
457 dm_tm_destroy(cmd->tm);
458 dm_block_manager_destroy(cmd->bm);
461 typedef unsigned long (*flags_mutator)(unsigned long);
463 static void update_flags(struct cache_disk_superblock *disk_super,
464 flags_mutator mutator)
466 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags));
467 disk_super->flags = cpu_to_le32(sb_flags);
470 static unsigned long set_clean_shutdown(unsigned long flags)
472 set_bit(CLEAN_SHUTDOWN, &flags);
476 static unsigned long clear_clean_shutdown(unsigned long flags)
478 clear_bit(CLEAN_SHUTDOWN, &flags);
482 static void read_superblock_fields(struct dm_cache_metadata *cmd,
483 struct cache_disk_superblock *disk_super)
485 cmd->root = le64_to_cpu(disk_super->mapping_root);
486 cmd->hint_root = le64_to_cpu(disk_super->hint_root);
487 cmd->discard_root = le64_to_cpu(disk_super->discard_root);
488 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
489 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
490 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
491 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
492 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
493 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]);
494 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]);
495 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]);
496 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size);
498 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits);
499 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses);
500 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits);
501 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses);
503 cmd->changed = false;
507 * The mutator updates the superblock flags.
509 static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
510 flags_mutator mutator)
513 struct cache_disk_superblock *disk_super;
514 struct dm_block *sblock;
516 r = superblock_lock(cmd, &sblock);
520 disk_super = dm_block_data(sblock);
521 update_flags(disk_super, mutator);
522 read_superblock_fields(cmd, disk_super);
523 dm_bm_unlock(sblock);
525 return dm_bm_flush(cmd->bm);
528 static int __begin_transaction(struct dm_cache_metadata *cmd)
531 struct cache_disk_superblock *disk_super;
532 struct dm_block *sblock;
535 * We re-read the superblock every time. Shouldn't need to do this
538 r = superblock_read_lock(cmd, &sblock);
542 disk_super = dm_block_data(sblock);
543 read_superblock_fields(cmd, disk_super);
544 dm_bm_unlock(sblock);
549 static int __commit_transaction(struct dm_cache_metadata *cmd,
550 flags_mutator mutator)
554 struct cache_disk_superblock *disk_super;
555 struct dm_block *sblock;
558 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
560 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512);
562 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root,
567 r = dm_tm_pre_commit(cmd->tm);
571 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
575 r = superblock_lock(cmd, &sblock);
579 disk_super = dm_block_data(sblock);
582 update_flags(disk_super, mutator);
584 disk_super->mapping_root = cpu_to_le64(cmd->root);
585 disk_super->hint_root = cpu_to_le64(cmd->hint_root);
586 disk_super->discard_root = cpu_to_le64(cmd->discard_root);
587 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
588 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
589 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
590 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
591 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
592 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]);
593 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]);
595 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits);
596 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
597 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
598 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
600 r = dm_sm_copy_root(cmd->metadata_sm, &disk_super->metadata_space_map_root,
603 dm_bm_unlock(sblock);
607 return dm_tm_commit(cmd->tm, sblock);
610 /*----------------------------------------------------------------*/
613 * The mappings are held in a dm-array that has 64-bit values stored in
614 * little-endian format. The index is the cblock, the high 48bits of the
615 * value are the oblock and the low 16 bit the flags.
617 #define FLAGS_MASK ((1 << 16) - 1)
619 static __le64 pack_value(dm_oblock_t block, unsigned flags)
621 uint64_t value = from_oblock(block);
623 value = value | (flags & FLAGS_MASK);
624 return cpu_to_le64(value);
627 static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
629 uint64_t value = le64_to_cpu(value_le);
630 uint64_t b = value >> 16;
631 *block = to_oblock(b);
632 *flags = value & FLAGS_MASK;
635 /*----------------------------------------------------------------*/
637 struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
638 sector_t data_block_size,
639 bool may_format_device,
640 size_t policy_hint_size)
643 struct dm_cache_metadata *cmd;
645 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
647 DMERR("could not allocate metadata struct");
651 init_rwsem(&cmd->root_lock);
653 cmd->data_block_size = data_block_size;
654 cmd->cache_blocks = 0;
655 cmd->policy_hint_size = policy_hint_size;
658 r = __create_persistent_data_objects(cmd, may_format_device);
664 r = __begin_transaction_flags(cmd, clear_clean_shutdown);
666 dm_cache_metadata_close(cmd);
673 void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
675 __destroy_persistent_data_objects(cmd);
679 int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
682 __le64 null_mapping = pack_value(0, 0);
684 down_write(&cmd->root_lock);
685 __dm_bless_for_disk(&null_mapping);
686 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
687 from_cblock(new_cache_size),
688 &null_mapping, &cmd->root);
690 cmd->cache_blocks = new_cache_size;
692 up_write(&cmd->root_lock);
697 int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
698 sector_t discard_block_size,
699 dm_dblock_t new_nr_entries)
703 down_write(&cmd->root_lock);
704 r = dm_bitset_resize(&cmd->discard_info,
706 from_dblock(cmd->discard_nr_blocks),
707 from_dblock(new_nr_entries),
708 false, &cmd->discard_root);
710 cmd->discard_block_size = discard_block_size;
711 cmd->discard_nr_blocks = new_nr_entries;
715 up_write(&cmd->root_lock);
720 static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
722 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
723 from_dblock(b), &cmd->discard_root);
726 static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
728 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
729 from_dblock(b), &cmd->discard_root);
732 static int __is_discarded(struct dm_cache_metadata *cmd, dm_dblock_t b,
735 return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root,
736 from_dblock(b), &cmd->discard_root,
740 static int __discard(struct dm_cache_metadata *cmd,
741 dm_dblock_t dblock, bool discard)
745 r = (discard ? __set_discard : __clear_discard)(cmd, dblock);
753 int dm_cache_set_discard(struct dm_cache_metadata *cmd,
754 dm_dblock_t dblock, bool discard)
758 down_write(&cmd->root_lock);
759 r = __discard(cmd, dblock, discard);
760 up_write(&cmd->root_lock);
765 static int __load_discards(struct dm_cache_metadata *cmd,
766 load_discard_fn fn, void *context)
772 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
773 dm_dblock_t dblock = to_dblock(b);
775 if (cmd->clean_when_opened) {
776 r = __is_discarded(cmd, dblock, &discard);
782 r = fn(context, cmd->discard_block_size, dblock, discard);
790 int dm_cache_load_discards(struct dm_cache_metadata *cmd,
791 load_discard_fn fn, void *context)
795 down_read(&cmd->root_lock);
796 r = __load_discards(cmd, fn, context);
797 up_read(&cmd->root_lock);
802 dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd)
806 down_read(&cmd->root_lock);
807 r = cmd->cache_blocks;
808 up_read(&cmd->root_lock);
813 static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
816 __le64 value = pack_value(0, 0);
818 __dm_bless_for_disk(&value);
819 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
828 int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
832 down_write(&cmd->root_lock);
833 r = __remove(cmd, cblock);
834 up_write(&cmd->root_lock);
839 static int __insert(struct dm_cache_metadata *cmd,
840 dm_cblock_t cblock, dm_oblock_t oblock)
843 __le64 value = pack_value(oblock, M_VALID);
844 __dm_bless_for_disk(&value);
846 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
855 int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
856 dm_cblock_t cblock, dm_oblock_t oblock)
860 down_write(&cmd->root_lock);
861 r = __insert(cmd, cblock, oblock);
862 up_write(&cmd->root_lock);
871 struct dm_cache_metadata *cmd;
872 bool respect_dirty_flags;
876 static bool policy_unchanged(struct dm_cache_metadata *cmd,
877 struct dm_cache_policy *policy)
879 const char *policy_name = dm_cache_policy_get_name(policy);
880 const unsigned *policy_version = dm_cache_policy_get_version(policy);
881 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy);
884 * Ensure policy names match.
886 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name)))
890 * Ensure policy major versions match.
892 if (cmd->policy_version[0] != policy_version[0])
896 * Ensure policy hint sizes match.
898 if (cmd->policy_hint_size != policy_hint_size)
904 static bool hints_array_initialized(struct dm_cache_metadata *cmd)
906 return cmd->hint_root && cmd->policy_hint_size;
909 static bool hints_array_available(struct dm_cache_metadata *cmd,
910 struct dm_cache_policy *policy)
912 return cmd->clean_when_opened && policy_unchanged(cmd, policy) &&
913 hints_array_initialized(cmd);
916 static int __load_mapping(void *context, uint64_t cblock, void *leaf)
921 __le32 hint_value = 0;
924 struct thunk *thunk = context;
925 struct dm_cache_metadata *cmd = thunk->cmd;
927 memcpy(&value, leaf, sizeof(value));
928 unpack_value(value, &oblock, &flags);
930 if (flags & M_VALID) {
931 if (thunk->hints_valid) {
932 r = dm_array_get_value(&cmd->hint_info, cmd->hint_root,
933 cblock, &hint_value);
934 if (r && r != -ENODATA)
938 dirty = thunk->respect_dirty_flags ? (flags & M_DIRTY) : true;
939 r = thunk->fn(thunk->context, oblock, to_cblock(cblock),
940 dirty, le32_to_cpu(hint_value), thunk->hints_valid);
946 static int __load_mappings(struct dm_cache_metadata *cmd,
947 struct dm_cache_policy *policy,
948 load_mapping_fn fn, void *context)
953 thunk.context = context;
956 thunk.respect_dirty_flags = cmd->clean_when_opened;
957 thunk.hints_valid = hints_array_available(cmd, policy);
959 return dm_array_walk(&cmd->info, cmd->root, __load_mapping, &thunk);
962 int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
963 struct dm_cache_policy *policy,
964 load_mapping_fn fn, void *context)
968 down_read(&cmd->root_lock);
969 r = __load_mappings(cmd, policy, fn, context);
970 up_read(&cmd->root_lock);
975 static int __dump_mapping(void *context, uint64_t cblock, void *leaf)
982 memcpy(&value, leaf, sizeof(value));
983 unpack_value(value, &oblock, &flags);
988 static int __dump_mappings(struct dm_cache_metadata *cmd)
990 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL);
993 void dm_cache_dump(struct dm_cache_metadata *cmd)
995 down_read(&cmd->root_lock);
996 __dump_mappings(cmd);
997 up_read(&cmd->root_lock);
1000 int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
1004 down_read(&cmd->root_lock);
1006 up_read(&cmd->root_lock);
1011 static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty)
1018 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value);
1022 unpack_value(value, &oblock, &flags);
1024 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty))
1025 /* nothing to be done */
1028 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0));
1029 __dm_bless_for_disk(&value);
1031 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock),
1032 &value, &cmd->root);
1036 cmd->changed = true;
1041 int dm_cache_set_dirty(struct dm_cache_metadata *cmd,
1042 dm_cblock_t cblock, bool dirty)
1046 down_write(&cmd->root_lock);
1047 r = __dirty(cmd, cblock, dirty);
1048 up_write(&cmd->root_lock);
1053 void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
1054 struct dm_cache_statistics *stats)
1056 down_read(&cmd->root_lock);
1057 *stats = cmd->stats;
1058 up_read(&cmd->root_lock);
1061 void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
1062 struct dm_cache_statistics *stats)
1064 down_write(&cmd->root_lock);
1065 cmd->stats = *stats;
1066 up_write(&cmd->root_lock);
1069 int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
1072 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
1073 clear_clean_shutdown);
1075 down_write(&cmd->root_lock);
1076 r = __commit_transaction(cmd, mutator);
1080 r = __begin_transaction(cmd);
1083 up_write(&cmd->root_lock);
1087 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
1092 down_read(&cmd->root_lock);
1093 r = dm_sm_get_nr_free(cmd->metadata_sm, result);
1094 up_read(&cmd->root_lock);
1099 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
1104 down_read(&cmd->root_lock);
1105 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
1106 up_read(&cmd->root_lock);
1111 /*----------------------------------------------------------------*/
1113 static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1118 const char *policy_name = dm_cache_policy_get_name(policy);
1119 const unsigned *policy_version = dm_cache_policy_get_version(policy);
1121 if (!policy_name[0] ||
1122 (strlen(policy_name) > sizeof(cmd->policy_name) - 1))
1125 if (!policy_unchanged(cmd, policy)) {
1126 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name));
1127 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version));
1129 hint_size = dm_cache_policy_get_hint_size(policy);
1131 return 0; /* short-circuit hints initialization */
1132 cmd->policy_hint_size = hint_size;
1134 if (cmd->hint_root) {
1135 r = dm_array_del(&cmd->hint_info, cmd->hint_root);
1140 r = dm_array_empty(&cmd->hint_info, &cmd->hint_root);
1144 value = cpu_to_le32(0);
1145 __dm_bless_for_disk(&value);
1146 r = dm_array_resize(&cmd->hint_info, cmd->hint_root, 0,
1147 from_cblock(cmd->cache_blocks),
1148 &value, &cmd->hint_root);
1156 int dm_cache_begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
1160 down_write(&cmd->root_lock);
1161 r = begin_hints(cmd, policy);
1162 up_write(&cmd->root_lock);
1167 static int save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
1171 __le32 value = cpu_to_le32(hint);
1172 __dm_bless_for_disk(&value);
1174 r = dm_array_set_value(&cmd->hint_info, cmd->hint_root,
1175 from_cblock(cblock), &value, &cmd->hint_root);
1176 cmd->changed = true;
1181 int dm_cache_save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
1186 if (!hints_array_initialized(cmd))
1189 down_write(&cmd->root_lock);
1190 r = save_hint(cmd, cblock, hint);
1191 up_write(&cmd->root_lock);