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
;
88 struct dm_cache_metadata
{
89 struct block_device
*bdev
;
90 struct dm_block_manager
*bm
;
91 struct dm_space_map
*metadata_sm
;
92 struct dm_transaction_manager
*tm
;
94 struct dm_array_info info
;
95 struct dm_array_info hint_info
;
96 struct dm_disk_bitset discard_info
;
98 struct rw_semaphore root_lock
;
100 dm_block_t hint_root
;
101 dm_block_t discard_root
;
103 sector_t discard_block_size
;
104 dm_dblock_t discard_nr_blocks
;
106 sector_t data_block_size
;
107 dm_cblock_t cache_blocks
;
109 bool clean_when_opened
:1;
111 char policy_name
[CACHE_POLICY_NAME_SIZE
];
112 size_t policy_hint_size
;
113 struct dm_cache_statistics stats
;
116 /*-------------------------------------------------------------------
117 * superblock validator
118 *-----------------------------------------------------------------*/
120 #define SUPERBLOCK_CSUM_XOR 9031977
122 static void sb_prepare_for_write(struct dm_block_validator
*v
,
124 size_t sb_block_size
)
126 struct cache_disk_superblock
*disk_super
= dm_block_data(b
);
128 disk_super
->blocknr
= cpu_to_le64(dm_block_location(b
));
129 disk_super
->csum
= cpu_to_le32(dm_bm_checksum(&disk_super
->flags
,
130 sb_block_size
- sizeof(__le32
),
131 SUPERBLOCK_CSUM_XOR
));
134 static int sb_check(struct dm_block_validator
*v
,
136 size_t sb_block_size
)
138 struct cache_disk_superblock
*disk_super
= dm_block_data(b
);
141 if (dm_block_location(b
) != le64_to_cpu(disk_super
->blocknr
)) {
142 DMERR("sb_check failed: blocknr %llu: wanted %llu",
143 le64_to_cpu(disk_super
->blocknr
),
144 (unsigned long long)dm_block_location(b
));
148 if (le64_to_cpu(disk_super
->magic
) != CACHE_SUPERBLOCK_MAGIC
) {
149 DMERR("sb_check failed: magic %llu: wanted %llu",
150 le64_to_cpu(disk_super
->magic
),
151 (unsigned long long)CACHE_SUPERBLOCK_MAGIC
);
155 csum_le
= cpu_to_le32(dm_bm_checksum(&disk_super
->flags
,
156 sb_block_size
- sizeof(__le32
),
157 SUPERBLOCK_CSUM_XOR
));
158 if (csum_le
!= disk_super
->csum
) {
159 DMERR("sb_check failed: csum %u: wanted %u",
160 le32_to_cpu(csum_le
), le32_to_cpu(disk_super
->csum
));
167 static struct dm_block_validator sb_validator
= {
168 .name
= "superblock",
169 .prepare_for_write
= sb_prepare_for_write
,
173 /*----------------------------------------------------------------*/
175 static int superblock_read_lock(struct dm_cache_metadata
*cmd
,
176 struct dm_block
**sblock
)
178 return dm_bm_read_lock(cmd
->bm
, CACHE_SUPERBLOCK_LOCATION
,
179 &sb_validator
, sblock
);
182 static int superblock_lock_zero(struct dm_cache_metadata
*cmd
,
183 struct dm_block
**sblock
)
185 return dm_bm_write_lock_zero(cmd
->bm
, CACHE_SUPERBLOCK_LOCATION
,
186 &sb_validator
, sblock
);
189 static int superblock_lock(struct dm_cache_metadata
*cmd
,
190 struct dm_block
**sblock
)
192 return dm_bm_write_lock(cmd
->bm
, CACHE_SUPERBLOCK_LOCATION
,
193 &sb_validator
, sblock
);
196 /*----------------------------------------------------------------*/
198 static int __superblock_all_zeroes(struct dm_block_manager
*bm
, int *result
)
203 __le64
*data_le
, zero
= cpu_to_le64(0);
204 unsigned sb_block_size
= dm_bm_block_size(bm
) / sizeof(__le64
);
207 * We can't use a validator here - it may be all zeroes.
209 r
= dm_bm_read_lock(bm
, CACHE_SUPERBLOCK_LOCATION
, NULL
, &b
);
213 data_le
= dm_block_data(b
);
215 for (i
= 0; i
< sb_block_size
; i
++) {
216 if (data_le
[i
] != zero
) {
222 return dm_bm_unlock(b
);
225 static void __setup_mapping_info(struct dm_cache_metadata
*cmd
)
227 struct dm_btree_value_type vt
;
230 vt
.size
= sizeof(__le64
);
234 dm_array_info_init(&cmd
->info
, cmd
->tm
, &vt
);
236 if (cmd
->policy_hint_size
) {
237 vt
.size
= sizeof(__le32
);
238 dm_array_info_init(&cmd
->hint_info
, cmd
->tm
, &vt
);
242 static int __write_initial_superblock(struct dm_cache_metadata
*cmd
)
245 struct dm_block
*sblock
;
247 struct cache_disk_superblock
*disk_super
;
248 sector_t bdev_size
= i_size_read(cmd
->bdev
->bd_inode
) >> SECTOR_SHIFT
;
250 /* FIXME: see if we can lose the max sectors limit */
251 if (bdev_size
> DM_CACHE_METADATA_MAX_SECTORS
)
252 bdev_size
= DM_CACHE_METADATA_MAX_SECTORS
;
254 r
= dm_sm_root_size(cmd
->metadata_sm
, &metadata_len
);
258 r
= dm_tm_pre_commit(cmd
->tm
);
262 r
= superblock_lock_zero(cmd
, &sblock
);
266 disk_super
= dm_block_data(sblock
);
267 disk_super
->flags
= 0;
268 memset(disk_super
->uuid
, 0, sizeof(disk_super
->uuid
));
269 disk_super
->magic
= cpu_to_le64(CACHE_SUPERBLOCK_MAGIC
);
270 disk_super
->version
= cpu_to_le32(CACHE_VERSION
);
271 memset(disk_super
->policy_name
, 0, CACHE_POLICY_NAME_SIZE
);
272 disk_super
->policy_hint_size
= 0;
274 r
= dm_sm_copy_root(cmd
->metadata_sm
, &disk_super
->metadata_space_map_root
,
279 disk_super
->mapping_root
= cpu_to_le64(cmd
->root
);
280 disk_super
->hint_root
= cpu_to_le64(cmd
->hint_root
);
281 disk_super
->discard_root
= cpu_to_le64(cmd
->discard_root
);
282 disk_super
->discard_block_size
= cpu_to_le64(cmd
->discard_block_size
);
283 disk_super
->discard_nr_blocks
= cpu_to_le64(from_dblock(cmd
->discard_nr_blocks
));
284 disk_super
->metadata_block_size
= cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE
>> SECTOR_SHIFT
);
285 disk_super
->data_block_size
= cpu_to_le32(cmd
->data_block_size
);
286 disk_super
->cache_blocks
= cpu_to_le32(0);
287 memset(disk_super
->policy_name
, 0, sizeof(disk_super
->policy_name
));
289 disk_super
->read_hits
= cpu_to_le32(0);
290 disk_super
->read_misses
= cpu_to_le32(0);
291 disk_super
->write_hits
= cpu_to_le32(0);
292 disk_super
->write_misses
= cpu_to_le32(0);
294 return dm_tm_commit(cmd
->tm
, sblock
);
297 dm_bm_unlock(sblock
);
301 static int __format_metadata(struct dm_cache_metadata
*cmd
)
305 r
= dm_tm_create_with_sm(cmd
->bm
, CACHE_SUPERBLOCK_LOCATION
,
306 &cmd
->tm
, &cmd
->metadata_sm
);
308 DMERR("tm_create_with_sm failed");
312 __setup_mapping_info(cmd
);
314 r
= dm_array_empty(&cmd
->info
, &cmd
->root
);
318 dm_disk_bitset_init(cmd
->tm
, &cmd
->discard_info
);
320 r
= dm_bitset_empty(&cmd
->discard_info
, &cmd
->discard_root
);
324 cmd
->discard_block_size
= 0;
325 cmd
->discard_nr_blocks
= 0;
327 r
= __write_initial_superblock(cmd
);
331 cmd
->clean_when_opened
= true;
335 dm_tm_destroy(cmd
->tm
);
336 dm_sm_destroy(cmd
->metadata_sm
);
341 static int __check_incompat_features(struct cache_disk_superblock
*disk_super
,
342 struct dm_cache_metadata
*cmd
)
346 features
= le32_to_cpu(disk_super
->incompat_flags
) & ~DM_CACHE_FEATURE_INCOMPAT_SUPP
;
348 DMERR("could not access metadata due to unsupported optional features (%lx).",
349 (unsigned long)features
);
354 * Check for read-only metadata to skip the following RDWR checks.
356 if (get_disk_ro(cmd
->bdev
->bd_disk
))
359 features
= le32_to_cpu(disk_super
->compat_ro_flags
) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP
;
361 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
362 (unsigned long)features
);
369 static int __open_metadata(struct dm_cache_metadata
*cmd
)
372 struct dm_block
*sblock
;
373 struct cache_disk_superblock
*disk_super
;
374 unsigned long sb_flags
;
376 r
= superblock_read_lock(cmd
, &sblock
);
378 DMERR("couldn't read lock superblock");
382 disk_super
= dm_block_data(sblock
);
384 r
= __check_incompat_features(disk_super
, cmd
);
388 r
= dm_tm_open_with_sm(cmd
->bm
, CACHE_SUPERBLOCK_LOCATION
,
389 disk_super
->metadata_space_map_root
,
390 sizeof(disk_super
->metadata_space_map_root
),
391 &cmd
->tm
, &cmd
->metadata_sm
);
393 DMERR("tm_open_with_sm failed");
397 __setup_mapping_info(cmd
);
398 dm_disk_bitset_init(cmd
->tm
, &cmd
->discard_info
);
399 sb_flags
= le32_to_cpu(disk_super
->flags
);
400 cmd
->clean_when_opened
= test_bit(CLEAN_SHUTDOWN
, &sb_flags
);
401 return dm_bm_unlock(sblock
);
404 dm_bm_unlock(sblock
);
408 static int __open_or_format_metadata(struct dm_cache_metadata
*cmd
,
413 r
= __superblock_all_zeroes(cmd
->bm
, &unformatted
);
418 return format_device
? __format_metadata(cmd
) : -EPERM
;
420 return __open_metadata(cmd
);
423 static int __create_persistent_data_objects(struct dm_cache_metadata
*cmd
,
424 bool may_format_device
)
427 cmd
->bm
= dm_block_manager_create(cmd
->bdev
, DM_CACHE_METADATA_BLOCK_SIZE
,
428 CACHE_METADATA_CACHE_SIZE
,
429 CACHE_MAX_CONCURRENT_LOCKS
);
430 if (IS_ERR(cmd
->bm
)) {
431 DMERR("could not create block manager");
432 return PTR_ERR(cmd
->bm
);
435 r
= __open_or_format_metadata(cmd
, may_format_device
);
437 dm_block_manager_destroy(cmd
->bm
);
442 static void __destroy_persistent_data_objects(struct dm_cache_metadata
*cmd
)
444 dm_sm_destroy(cmd
->metadata_sm
);
445 dm_tm_destroy(cmd
->tm
);
446 dm_block_manager_destroy(cmd
->bm
);
449 typedef unsigned long (*flags_mutator
)(unsigned long);
451 static void update_flags(struct cache_disk_superblock
*disk_super
,
452 flags_mutator mutator
)
454 uint32_t sb_flags
= mutator(le32_to_cpu(disk_super
->flags
));
455 disk_super
->flags
= cpu_to_le32(sb_flags
);
458 static unsigned long set_clean_shutdown(unsigned long flags
)
460 set_bit(CLEAN_SHUTDOWN
, &flags
);
464 static unsigned long clear_clean_shutdown(unsigned long flags
)
466 clear_bit(CLEAN_SHUTDOWN
, &flags
);
470 static void read_superblock_fields(struct dm_cache_metadata
*cmd
,
471 struct cache_disk_superblock
*disk_super
)
473 cmd
->root
= le64_to_cpu(disk_super
->mapping_root
);
474 cmd
->hint_root
= le64_to_cpu(disk_super
->hint_root
);
475 cmd
->discard_root
= le64_to_cpu(disk_super
->discard_root
);
476 cmd
->discard_block_size
= le64_to_cpu(disk_super
->discard_block_size
);
477 cmd
->discard_nr_blocks
= to_dblock(le64_to_cpu(disk_super
->discard_nr_blocks
));
478 cmd
->data_block_size
= le32_to_cpu(disk_super
->data_block_size
);
479 cmd
->cache_blocks
= to_cblock(le32_to_cpu(disk_super
->cache_blocks
));
480 strncpy(cmd
->policy_name
, disk_super
->policy_name
, sizeof(cmd
->policy_name
));
481 cmd
->policy_hint_size
= le32_to_cpu(disk_super
->policy_hint_size
);
483 cmd
->stats
.read_hits
= le32_to_cpu(disk_super
->read_hits
);
484 cmd
->stats
.read_misses
= le32_to_cpu(disk_super
->read_misses
);
485 cmd
->stats
.write_hits
= le32_to_cpu(disk_super
->write_hits
);
486 cmd
->stats
.write_misses
= le32_to_cpu(disk_super
->write_misses
);
488 cmd
->changed
= false;
492 * The mutator updates the superblock flags.
494 static int __begin_transaction_flags(struct dm_cache_metadata
*cmd
,
495 flags_mutator mutator
)
498 struct cache_disk_superblock
*disk_super
;
499 struct dm_block
*sblock
;
501 r
= superblock_lock(cmd
, &sblock
);
505 disk_super
= dm_block_data(sblock
);
506 update_flags(disk_super
, mutator
);
507 read_superblock_fields(cmd
, disk_super
);
509 return dm_bm_flush_and_unlock(cmd
->bm
, sblock
);
512 static int __begin_transaction(struct dm_cache_metadata
*cmd
)
515 struct cache_disk_superblock
*disk_super
;
516 struct dm_block
*sblock
;
519 * We re-read the superblock every time. Shouldn't need to do this
522 r
= superblock_read_lock(cmd
, &sblock
);
526 disk_super
= dm_block_data(sblock
);
527 read_superblock_fields(cmd
, disk_super
);
528 dm_bm_unlock(sblock
);
533 static int __commit_transaction(struct dm_cache_metadata
*cmd
,
534 flags_mutator mutator
)
538 struct cache_disk_superblock
*disk_super
;
539 struct dm_block
*sblock
;
542 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
544 BUILD_BUG_ON(sizeof(struct cache_disk_superblock
) > 512);
546 r
= dm_bitset_flush(&cmd
->discard_info
, cmd
->discard_root
,
551 r
= dm_tm_pre_commit(cmd
->tm
);
555 r
= dm_sm_root_size(cmd
->metadata_sm
, &metadata_len
);
559 r
= superblock_lock(cmd
, &sblock
);
563 disk_super
= dm_block_data(sblock
);
566 update_flags(disk_super
, mutator
);
568 disk_super
->mapping_root
= cpu_to_le64(cmd
->root
);
569 disk_super
->hint_root
= cpu_to_le64(cmd
->hint_root
);
570 disk_super
->discard_root
= cpu_to_le64(cmd
->discard_root
);
571 disk_super
->discard_block_size
= cpu_to_le64(cmd
->discard_block_size
);
572 disk_super
->discard_nr_blocks
= cpu_to_le64(from_dblock(cmd
->discard_nr_blocks
));
573 disk_super
->cache_blocks
= cpu_to_le32(from_cblock(cmd
->cache_blocks
));
574 strncpy(disk_super
->policy_name
, cmd
->policy_name
, sizeof(disk_super
->policy_name
));
576 disk_super
->read_hits
= cpu_to_le32(cmd
->stats
.read_hits
);
577 disk_super
->read_misses
= cpu_to_le32(cmd
->stats
.read_misses
);
578 disk_super
->write_hits
= cpu_to_le32(cmd
->stats
.write_hits
);
579 disk_super
->write_misses
= cpu_to_le32(cmd
->stats
.write_misses
);
581 r
= dm_sm_copy_root(cmd
->metadata_sm
, &disk_super
->metadata_space_map_root
,
584 dm_bm_unlock(sblock
);
588 return dm_tm_commit(cmd
->tm
, sblock
);
591 /*----------------------------------------------------------------*/
594 * The mappings are held in a dm-array that has 64-bit values stored in
595 * little-endian format. The index is the cblock, the high 48bits of the
596 * value are the oblock and the low 16 bit the flags.
598 #define FLAGS_MASK ((1 << 16) - 1)
600 static __le64
pack_value(dm_oblock_t block
, unsigned flags
)
602 uint64_t value
= from_oblock(block
);
604 value
= value
| (flags
& FLAGS_MASK
);
605 return cpu_to_le64(value
);
608 static void unpack_value(__le64 value_le
, dm_oblock_t
*block
, unsigned *flags
)
610 uint64_t value
= le64_to_cpu(value_le
);
611 uint64_t b
= value
>> 16;
612 *block
= to_oblock(b
);
613 *flags
= value
& FLAGS_MASK
;
616 /*----------------------------------------------------------------*/
618 struct dm_cache_metadata
*dm_cache_metadata_open(struct block_device
*bdev
,
619 sector_t data_block_size
,
620 bool may_format_device
,
621 size_t policy_hint_size
)
624 struct dm_cache_metadata
*cmd
;
626 cmd
= kzalloc(sizeof(*cmd
), GFP_KERNEL
);
628 DMERR("could not allocate metadata struct");
632 init_rwsem(&cmd
->root_lock
);
634 cmd
->data_block_size
= data_block_size
;
635 cmd
->cache_blocks
= 0;
636 cmd
->policy_hint_size
= policy_hint_size
;
639 r
= __create_persistent_data_objects(cmd
, may_format_device
);
645 r
= __begin_transaction_flags(cmd
, clear_clean_shutdown
);
647 dm_cache_metadata_close(cmd
);
654 void dm_cache_metadata_close(struct dm_cache_metadata
*cmd
)
656 __destroy_persistent_data_objects(cmd
);
660 int dm_cache_resize(struct dm_cache_metadata
*cmd
, dm_cblock_t new_cache_size
)
663 __le64 null_mapping
= pack_value(0, 0);
665 down_write(&cmd
->root_lock
);
666 __dm_bless_for_disk(&null_mapping
);
667 r
= dm_array_resize(&cmd
->info
, cmd
->root
, from_cblock(cmd
->cache_blocks
),
668 from_cblock(new_cache_size
),
669 &null_mapping
, &cmd
->root
);
671 cmd
->cache_blocks
= new_cache_size
;
673 up_write(&cmd
->root_lock
);
678 int dm_cache_discard_bitset_resize(struct dm_cache_metadata
*cmd
,
679 sector_t discard_block_size
,
680 dm_dblock_t new_nr_entries
)
684 down_write(&cmd
->root_lock
);
685 r
= dm_bitset_resize(&cmd
->discard_info
,
687 from_dblock(cmd
->discard_nr_blocks
),
688 from_dblock(new_nr_entries
),
689 false, &cmd
->discard_root
);
691 cmd
->discard_block_size
= discard_block_size
;
692 cmd
->discard_nr_blocks
= new_nr_entries
;
696 up_write(&cmd
->root_lock
);
701 static int __set_discard(struct dm_cache_metadata
*cmd
, dm_dblock_t b
)
703 return dm_bitset_set_bit(&cmd
->discard_info
, cmd
->discard_root
,
704 from_dblock(b
), &cmd
->discard_root
);
707 static int __clear_discard(struct dm_cache_metadata
*cmd
, dm_dblock_t b
)
709 return dm_bitset_clear_bit(&cmd
->discard_info
, cmd
->discard_root
,
710 from_dblock(b
), &cmd
->discard_root
);
713 static int __is_discarded(struct dm_cache_metadata
*cmd
, dm_dblock_t b
,
716 return dm_bitset_test_bit(&cmd
->discard_info
, cmd
->discard_root
,
717 from_dblock(b
), &cmd
->discard_root
,
721 static int __discard(struct dm_cache_metadata
*cmd
,
722 dm_dblock_t dblock
, bool discard
)
726 r
= (discard
? __set_discard
: __clear_discard
)(cmd
, dblock
);
734 int dm_cache_set_discard(struct dm_cache_metadata
*cmd
,
735 dm_dblock_t dblock
, bool discard
)
739 down_write(&cmd
->root_lock
);
740 r
= __discard(cmd
, dblock
, discard
);
741 up_write(&cmd
->root_lock
);
746 static int __load_discards(struct dm_cache_metadata
*cmd
,
747 load_discard_fn fn
, void *context
)
753 for (b
= 0; b
< from_dblock(cmd
->discard_nr_blocks
); b
++) {
754 dm_dblock_t dblock
= to_dblock(b
);
756 if (cmd
->clean_when_opened
) {
757 r
= __is_discarded(cmd
, dblock
, &discard
);
763 r
= fn(context
, cmd
->discard_block_size
, dblock
, discard
);
771 int dm_cache_load_discards(struct dm_cache_metadata
*cmd
,
772 load_discard_fn fn
, void *context
)
776 down_read(&cmd
->root_lock
);
777 r
= __load_discards(cmd
, fn
, context
);
778 up_read(&cmd
->root_lock
);
783 dm_cblock_t
dm_cache_size(struct dm_cache_metadata
*cmd
)
787 down_read(&cmd
->root_lock
);
788 r
= cmd
->cache_blocks
;
789 up_read(&cmd
->root_lock
);
794 static int __remove(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
)
797 __le64 value
= pack_value(0, 0);
799 __dm_bless_for_disk(&value
);
800 r
= dm_array_set_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
),
809 int dm_cache_remove_mapping(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
)
813 down_write(&cmd
->root_lock
);
814 r
= __remove(cmd
, cblock
);
815 up_write(&cmd
->root_lock
);
820 static int __insert(struct dm_cache_metadata
*cmd
,
821 dm_cblock_t cblock
, dm_oblock_t oblock
)
824 __le64 value
= pack_value(oblock
, M_VALID
);
825 __dm_bless_for_disk(&value
);
827 r
= dm_array_set_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
),
836 int dm_cache_insert_mapping(struct dm_cache_metadata
*cmd
,
837 dm_cblock_t cblock
, dm_oblock_t oblock
)
841 down_write(&cmd
->root_lock
);
842 r
= __insert(cmd
, cblock
, oblock
);
843 up_write(&cmd
->root_lock
);
852 struct dm_cache_metadata
*cmd
;
853 bool respect_dirty_flags
;
857 static bool hints_array_initialized(struct dm_cache_metadata
*cmd
)
859 return cmd
->hint_root
&& cmd
->policy_hint_size
;
862 static bool hints_array_available(struct dm_cache_metadata
*cmd
,
863 const char *policy_name
)
865 bool policy_names_match
= !strncmp(cmd
->policy_name
, policy_name
,
866 sizeof(cmd
->policy_name
));
868 return cmd
->clean_when_opened
&& policy_names_match
&&
869 hints_array_initialized(cmd
);
872 static int __load_mapping(void *context
, uint64_t cblock
, void *leaf
)
877 __le32 hint_value
= 0;
880 struct thunk
*thunk
= context
;
881 struct dm_cache_metadata
*cmd
= thunk
->cmd
;
883 memcpy(&value
, leaf
, sizeof(value
));
884 unpack_value(value
, &oblock
, &flags
);
886 if (flags
& M_VALID
) {
887 if (thunk
->hints_valid
) {
888 r
= dm_array_get_value(&cmd
->hint_info
, cmd
->hint_root
,
889 cblock
, &hint_value
);
890 if (r
&& r
!= -ENODATA
)
894 dirty
= thunk
->respect_dirty_flags
? (flags
& M_DIRTY
) : true;
895 r
= thunk
->fn(thunk
->context
, oblock
, to_cblock(cblock
),
896 dirty
, le32_to_cpu(hint_value
), thunk
->hints_valid
);
902 static int __load_mappings(struct dm_cache_metadata
*cmd
, const char *policy_name
,
903 load_mapping_fn fn
, void *context
)
908 thunk
.context
= context
;
911 thunk
.respect_dirty_flags
= cmd
->clean_when_opened
;
912 thunk
.hints_valid
= hints_array_available(cmd
, policy_name
);
914 return dm_array_walk(&cmd
->info
, cmd
->root
, __load_mapping
, &thunk
);
917 int dm_cache_load_mappings(struct dm_cache_metadata
*cmd
, const char *policy_name
,
918 load_mapping_fn fn
, void *context
)
922 down_read(&cmd
->root_lock
);
923 r
= __load_mappings(cmd
, policy_name
, fn
, context
);
924 up_read(&cmd
->root_lock
);
929 static int __dump_mapping(void *context
, uint64_t cblock
, void *leaf
)
936 memcpy(&value
, leaf
, sizeof(value
));
937 unpack_value(value
, &oblock
, &flags
);
942 static int __dump_mappings(struct dm_cache_metadata
*cmd
)
944 return dm_array_walk(&cmd
->info
, cmd
->root
, __dump_mapping
, NULL
);
947 void dm_cache_dump(struct dm_cache_metadata
*cmd
)
949 down_read(&cmd
->root_lock
);
950 __dump_mappings(cmd
);
951 up_read(&cmd
->root_lock
);
954 int dm_cache_changed_this_transaction(struct dm_cache_metadata
*cmd
)
958 down_read(&cmd
->root_lock
);
960 up_read(&cmd
->root_lock
);
965 static int __dirty(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
, bool dirty
)
972 r
= dm_array_get_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
), &value
);
976 unpack_value(value
, &oblock
, &flags
);
978 if (((flags
& M_DIRTY
) && dirty
) || (!(flags
& M_DIRTY
) && !dirty
))
979 /* nothing to be done */
982 value
= pack_value(oblock
, flags
| (dirty
? M_DIRTY
: 0));
983 __dm_bless_for_disk(&value
);
985 r
= dm_array_set_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
),
995 int dm_cache_set_dirty(struct dm_cache_metadata
*cmd
,
996 dm_cblock_t cblock
, bool dirty
)
1000 down_write(&cmd
->root_lock
);
1001 r
= __dirty(cmd
, cblock
, dirty
);
1002 up_write(&cmd
->root_lock
);
1007 void dm_cache_metadata_get_stats(struct dm_cache_metadata
*cmd
,
1008 struct dm_cache_statistics
*stats
)
1010 down_read(&cmd
->root_lock
);
1011 memcpy(stats
, &cmd
->stats
, sizeof(*stats
));
1012 up_read(&cmd
->root_lock
);
1015 void dm_cache_metadata_set_stats(struct dm_cache_metadata
*cmd
,
1016 struct dm_cache_statistics
*stats
)
1018 down_write(&cmd
->root_lock
);
1019 memcpy(&cmd
->stats
, stats
, sizeof(*stats
));
1020 up_write(&cmd
->root_lock
);
1023 int dm_cache_commit(struct dm_cache_metadata
*cmd
, bool clean_shutdown
)
1026 flags_mutator mutator
= (clean_shutdown
? set_clean_shutdown
:
1027 clear_clean_shutdown
);
1029 down_write(&cmd
->root_lock
);
1030 r
= __commit_transaction(cmd
, mutator
);
1034 r
= __begin_transaction(cmd
);
1037 up_write(&cmd
->root_lock
);
1041 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata
*cmd
,
1046 down_read(&cmd
->root_lock
);
1047 r
= dm_sm_get_nr_free(cmd
->metadata_sm
, result
);
1048 up_read(&cmd
->root_lock
);
1053 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata
*cmd
,
1058 down_read(&cmd
->root_lock
);
1059 r
= dm_sm_get_nr_blocks(cmd
->metadata_sm
, result
);
1060 up_read(&cmd
->root_lock
);
1065 /*----------------------------------------------------------------*/
1067 static int begin_hints(struct dm_cache_metadata
*cmd
, struct dm_cache_policy
*policy
)
1072 const char *policy_name
= dm_cache_policy_get_name(policy
);
1074 if (!policy_name
[0] ||
1075 (strlen(policy_name
) > sizeof(cmd
->policy_name
) - 1))
1078 if (strcmp(cmd
->policy_name
, policy_name
)) {
1079 strncpy(cmd
->policy_name
, policy_name
, sizeof(cmd
->policy_name
));
1081 hint_size
= dm_cache_policy_get_hint_size(policy
);
1083 return 0; /* short-circuit hints initialization */
1084 cmd
->policy_hint_size
= hint_size
;
1086 if (cmd
->hint_root
) {
1087 r
= dm_array_del(&cmd
->hint_info
, cmd
->hint_root
);
1092 r
= dm_array_empty(&cmd
->hint_info
, &cmd
->hint_root
);
1096 value
= cpu_to_le32(0);
1097 __dm_bless_for_disk(&value
);
1098 r
= dm_array_resize(&cmd
->hint_info
, cmd
->hint_root
, 0,
1099 from_cblock(cmd
->cache_blocks
),
1100 &value
, &cmd
->hint_root
);
1108 int dm_cache_begin_hints(struct dm_cache_metadata
*cmd
, struct dm_cache_policy
*policy
)
1112 down_write(&cmd
->root_lock
);
1113 r
= begin_hints(cmd
, policy
);
1114 up_write(&cmd
->root_lock
);
1119 static int save_hint(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
,
1123 __le32 value
= cpu_to_le32(hint
);
1124 __dm_bless_for_disk(&value
);
1126 r
= dm_array_set_value(&cmd
->hint_info
, cmd
->hint_root
,
1127 from_cblock(cblock
), &value
, &cmd
->hint_root
);
1128 cmd
->changed
= true;
1133 int dm_cache_save_hint(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
,
1138 if (!hints_array_initialized(cmd
))
1141 down_write(&cmd
->root_lock
);
1142 r
= save_hint(cmd
, cblock
, hint
);
1143 up_write(&cmd
->root_lock
);