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
, bool *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
,
415 bool unformatted
= false;
417 r
= __superblock_all_zeroes(cmd
->bm
, &unformatted
);
422 return format_device
? __format_metadata(cmd
) : -EPERM
;
424 return __open_metadata(cmd
);
427 static int __create_persistent_data_objects(struct dm_cache_metadata
*cmd
,
428 bool may_format_device
)
431 cmd
->bm
= dm_block_manager_create(cmd
->bdev
, DM_CACHE_METADATA_BLOCK_SIZE
,
432 CACHE_METADATA_CACHE_SIZE
,
433 CACHE_MAX_CONCURRENT_LOCKS
);
434 if (IS_ERR(cmd
->bm
)) {
435 DMERR("could not create block manager");
436 return PTR_ERR(cmd
->bm
);
439 r
= __open_or_format_metadata(cmd
, may_format_device
);
441 dm_block_manager_destroy(cmd
->bm
);
446 static void __destroy_persistent_data_objects(struct dm_cache_metadata
*cmd
)
448 dm_sm_destroy(cmd
->metadata_sm
);
449 dm_tm_destroy(cmd
->tm
);
450 dm_block_manager_destroy(cmd
->bm
);
453 typedef unsigned long (*flags_mutator
)(unsigned long);
455 static void update_flags(struct cache_disk_superblock
*disk_super
,
456 flags_mutator mutator
)
458 uint32_t sb_flags
= mutator(le32_to_cpu(disk_super
->flags
));
459 disk_super
->flags
= cpu_to_le32(sb_flags
);
462 static unsigned long set_clean_shutdown(unsigned long flags
)
464 set_bit(CLEAN_SHUTDOWN
, &flags
);
468 static unsigned long clear_clean_shutdown(unsigned long flags
)
470 clear_bit(CLEAN_SHUTDOWN
, &flags
);
474 static void read_superblock_fields(struct dm_cache_metadata
*cmd
,
475 struct cache_disk_superblock
*disk_super
)
477 cmd
->root
= le64_to_cpu(disk_super
->mapping_root
);
478 cmd
->hint_root
= le64_to_cpu(disk_super
->hint_root
);
479 cmd
->discard_root
= le64_to_cpu(disk_super
->discard_root
);
480 cmd
->discard_block_size
= le64_to_cpu(disk_super
->discard_block_size
);
481 cmd
->discard_nr_blocks
= to_dblock(le64_to_cpu(disk_super
->discard_nr_blocks
));
482 cmd
->data_block_size
= le32_to_cpu(disk_super
->data_block_size
);
483 cmd
->cache_blocks
= to_cblock(le32_to_cpu(disk_super
->cache_blocks
));
484 strncpy(cmd
->policy_name
, disk_super
->policy_name
, sizeof(cmd
->policy_name
));
485 cmd
->policy_version
[0] = le32_to_cpu(disk_super
->policy_version
[0]);
486 cmd
->policy_version
[1] = le32_to_cpu(disk_super
->policy_version
[1]);
487 cmd
->policy_version
[2] = le32_to_cpu(disk_super
->policy_version
[2]);
488 cmd
->policy_hint_size
= le32_to_cpu(disk_super
->policy_hint_size
);
490 cmd
->stats
.read_hits
= le32_to_cpu(disk_super
->read_hits
);
491 cmd
->stats
.read_misses
= le32_to_cpu(disk_super
->read_misses
);
492 cmd
->stats
.write_hits
= le32_to_cpu(disk_super
->write_hits
);
493 cmd
->stats
.write_misses
= le32_to_cpu(disk_super
->write_misses
);
495 cmd
->changed
= false;
499 * The mutator updates the superblock flags.
501 static int __begin_transaction_flags(struct dm_cache_metadata
*cmd
,
502 flags_mutator mutator
)
505 struct cache_disk_superblock
*disk_super
;
506 struct dm_block
*sblock
;
508 r
= superblock_lock(cmd
, &sblock
);
512 disk_super
= dm_block_data(sblock
);
513 update_flags(disk_super
, mutator
);
514 read_superblock_fields(cmd
, disk_super
);
516 return dm_bm_flush_and_unlock(cmd
->bm
, sblock
);
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
);
671 * Checks that the given cache block is either unmapped or clean.
673 static int block_unmapped_or_clean(struct dm_cache_metadata
*cmd
, dm_cblock_t b
,
681 r
= dm_array_get_value(&cmd
->info
, cmd
->root
, from_cblock(b
), &value
);
683 DMERR("block_unmapped_or_clean failed");
687 unpack_value(value
, &ob
, &flags
);
688 *result
= !((flags
& M_VALID
) && (flags
& M_DIRTY
));
693 static int blocks_are_unmapped_or_clean(struct dm_cache_metadata
*cmd
,
694 dm_cblock_t begin
, dm_cblock_t end
,
700 while (begin
!= end
) {
701 r
= block_unmapped_or_clean(cmd
, begin
, result
);
706 DMERR("cache block %llu is dirty",
707 (unsigned long long) from_cblock(begin
));
711 begin
= to_cblock(from_cblock(begin
) + 1);
717 int dm_cache_resize(struct dm_cache_metadata
*cmd
, dm_cblock_t new_cache_size
)
721 __le64 null_mapping
= pack_value(0, 0);
723 down_write(&cmd
->root_lock
);
724 __dm_bless_for_disk(&null_mapping
);
726 if (from_cblock(new_cache_size
) < from_cblock(cmd
->cache_blocks
)) {
727 r
= blocks_are_unmapped_or_clean(cmd
, new_cache_size
, cmd
->cache_blocks
, &clean
);
729 __dm_unbless_for_disk(&null_mapping
);
734 DMERR("unable to shrink cache due to dirty blocks");
736 __dm_unbless_for_disk(&null_mapping
);
741 r
= dm_array_resize(&cmd
->info
, cmd
->root
, from_cblock(cmd
->cache_blocks
),
742 from_cblock(new_cache_size
),
743 &null_mapping
, &cmd
->root
);
745 cmd
->cache_blocks
= new_cache_size
;
749 up_write(&cmd
->root_lock
);
754 int dm_cache_discard_bitset_resize(struct dm_cache_metadata
*cmd
,
755 sector_t discard_block_size
,
756 dm_dblock_t new_nr_entries
)
760 down_write(&cmd
->root_lock
);
761 r
= dm_bitset_resize(&cmd
->discard_info
,
763 from_dblock(cmd
->discard_nr_blocks
),
764 from_dblock(new_nr_entries
),
765 false, &cmd
->discard_root
);
767 cmd
->discard_block_size
= discard_block_size
;
768 cmd
->discard_nr_blocks
= new_nr_entries
;
772 up_write(&cmd
->root_lock
);
777 static int __set_discard(struct dm_cache_metadata
*cmd
, dm_dblock_t b
)
779 return dm_bitset_set_bit(&cmd
->discard_info
, cmd
->discard_root
,
780 from_dblock(b
), &cmd
->discard_root
);
783 static int __clear_discard(struct dm_cache_metadata
*cmd
, dm_dblock_t b
)
785 return dm_bitset_clear_bit(&cmd
->discard_info
, cmd
->discard_root
,
786 from_dblock(b
), &cmd
->discard_root
);
789 static int __is_discarded(struct dm_cache_metadata
*cmd
, dm_dblock_t b
,
792 return dm_bitset_test_bit(&cmd
->discard_info
, cmd
->discard_root
,
793 from_dblock(b
), &cmd
->discard_root
,
797 static int __discard(struct dm_cache_metadata
*cmd
,
798 dm_dblock_t dblock
, bool discard
)
802 r
= (discard
? __set_discard
: __clear_discard
)(cmd
, dblock
);
810 int dm_cache_set_discard(struct dm_cache_metadata
*cmd
,
811 dm_dblock_t dblock
, bool discard
)
815 down_write(&cmd
->root_lock
);
816 r
= __discard(cmd
, dblock
, discard
);
817 up_write(&cmd
->root_lock
);
822 static int __load_discards(struct dm_cache_metadata
*cmd
,
823 load_discard_fn fn
, void *context
)
829 for (b
= 0; b
< from_dblock(cmd
->discard_nr_blocks
); b
++) {
830 dm_dblock_t dblock
= to_dblock(b
);
832 if (cmd
->clean_when_opened
) {
833 r
= __is_discarded(cmd
, dblock
, &discard
);
839 r
= fn(context
, cmd
->discard_block_size
, dblock
, discard
);
847 int dm_cache_load_discards(struct dm_cache_metadata
*cmd
,
848 load_discard_fn fn
, void *context
)
852 down_read(&cmd
->root_lock
);
853 r
= __load_discards(cmd
, fn
, context
);
854 up_read(&cmd
->root_lock
);
859 dm_cblock_t
dm_cache_size(struct dm_cache_metadata
*cmd
)
863 down_read(&cmd
->root_lock
);
864 r
= cmd
->cache_blocks
;
865 up_read(&cmd
->root_lock
);
870 static int __remove(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
)
873 __le64 value
= pack_value(0, 0);
875 __dm_bless_for_disk(&value
);
876 r
= dm_array_set_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
),
885 int dm_cache_remove_mapping(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
)
889 down_write(&cmd
->root_lock
);
890 r
= __remove(cmd
, cblock
);
891 up_write(&cmd
->root_lock
);
896 static int __insert(struct dm_cache_metadata
*cmd
,
897 dm_cblock_t cblock
, dm_oblock_t oblock
)
900 __le64 value
= pack_value(oblock
, M_VALID
);
901 __dm_bless_for_disk(&value
);
903 r
= dm_array_set_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
),
912 int dm_cache_insert_mapping(struct dm_cache_metadata
*cmd
,
913 dm_cblock_t cblock
, dm_oblock_t oblock
)
917 down_write(&cmd
->root_lock
);
918 r
= __insert(cmd
, cblock
, oblock
);
919 up_write(&cmd
->root_lock
);
928 struct dm_cache_metadata
*cmd
;
929 bool respect_dirty_flags
;
933 static bool policy_unchanged(struct dm_cache_metadata
*cmd
,
934 struct dm_cache_policy
*policy
)
936 const char *policy_name
= dm_cache_policy_get_name(policy
);
937 const unsigned *policy_version
= dm_cache_policy_get_version(policy
);
938 size_t policy_hint_size
= dm_cache_policy_get_hint_size(policy
);
941 * Ensure policy names match.
943 if (strncmp(cmd
->policy_name
, policy_name
, sizeof(cmd
->policy_name
)))
947 * Ensure policy major versions match.
949 if (cmd
->policy_version
[0] != policy_version
[0])
953 * Ensure policy hint sizes match.
955 if (cmd
->policy_hint_size
!= policy_hint_size
)
961 static bool hints_array_initialized(struct dm_cache_metadata
*cmd
)
963 return cmd
->hint_root
&& cmd
->policy_hint_size
;
966 static bool hints_array_available(struct dm_cache_metadata
*cmd
,
967 struct dm_cache_policy
*policy
)
969 return cmd
->clean_when_opened
&& policy_unchanged(cmd
, policy
) &&
970 hints_array_initialized(cmd
);
973 static int __load_mapping(void *context
, uint64_t cblock
, void *leaf
)
978 __le32 hint_value
= 0;
981 struct thunk
*thunk
= context
;
982 struct dm_cache_metadata
*cmd
= thunk
->cmd
;
984 memcpy(&value
, leaf
, sizeof(value
));
985 unpack_value(value
, &oblock
, &flags
);
987 if (flags
& M_VALID
) {
988 if (thunk
->hints_valid
) {
989 r
= dm_array_get_value(&cmd
->hint_info
, cmd
->hint_root
,
990 cblock
, &hint_value
);
991 if (r
&& r
!= -ENODATA
)
995 dirty
= thunk
->respect_dirty_flags
? (flags
& M_DIRTY
) : true;
996 r
= thunk
->fn(thunk
->context
, oblock
, to_cblock(cblock
),
997 dirty
, le32_to_cpu(hint_value
), thunk
->hints_valid
);
1003 static int __load_mappings(struct dm_cache_metadata
*cmd
,
1004 struct dm_cache_policy
*policy
,
1005 load_mapping_fn fn
, void *context
)
1010 thunk
.context
= context
;
1013 thunk
.respect_dirty_flags
= cmd
->clean_when_opened
;
1014 thunk
.hints_valid
= hints_array_available(cmd
, policy
);
1016 return dm_array_walk(&cmd
->info
, cmd
->root
, __load_mapping
, &thunk
);
1019 int dm_cache_load_mappings(struct dm_cache_metadata
*cmd
,
1020 struct dm_cache_policy
*policy
,
1021 load_mapping_fn fn
, void *context
)
1025 down_read(&cmd
->root_lock
);
1026 r
= __load_mappings(cmd
, policy
, fn
, context
);
1027 up_read(&cmd
->root_lock
);
1032 static int __dump_mapping(void *context
, uint64_t cblock
, void *leaf
)
1039 memcpy(&value
, leaf
, sizeof(value
));
1040 unpack_value(value
, &oblock
, &flags
);
1045 static int __dump_mappings(struct dm_cache_metadata
*cmd
)
1047 return dm_array_walk(&cmd
->info
, cmd
->root
, __dump_mapping
, NULL
);
1050 void dm_cache_dump(struct dm_cache_metadata
*cmd
)
1052 down_read(&cmd
->root_lock
);
1053 __dump_mappings(cmd
);
1054 up_read(&cmd
->root_lock
);
1057 int dm_cache_changed_this_transaction(struct dm_cache_metadata
*cmd
)
1061 down_read(&cmd
->root_lock
);
1063 up_read(&cmd
->root_lock
);
1068 static int __dirty(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
, bool dirty
)
1075 r
= dm_array_get_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
), &value
);
1079 unpack_value(value
, &oblock
, &flags
);
1081 if (((flags
& M_DIRTY
) && dirty
) || (!(flags
& M_DIRTY
) && !dirty
))
1082 /* nothing to be done */
1085 value
= pack_value(oblock
, (flags
& ~M_DIRTY
) | (dirty
? M_DIRTY
: 0));
1086 __dm_bless_for_disk(&value
);
1088 r
= dm_array_set_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
),
1089 &value
, &cmd
->root
);
1093 cmd
->changed
= true;
1098 int dm_cache_set_dirty(struct dm_cache_metadata
*cmd
,
1099 dm_cblock_t cblock
, bool dirty
)
1103 down_write(&cmd
->root_lock
);
1104 r
= __dirty(cmd
, cblock
, dirty
);
1105 up_write(&cmd
->root_lock
);
1110 void dm_cache_metadata_get_stats(struct dm_cache_metadata
*cmd
,
1111 struct dm_cache_statistics
*stats
)
1113 down_read(&cmd
->root_lock
);
1114 *stats
= cmd
->stats
;
1115 up_read(&cmd
->root_lock
);
1118 void dm_cache_metadata_set_stats(struct dm_cache_metadata
*cmd
,
1119 struct dm_cache_statistics
*stats
)
1121 down_write(&cmd
->root_lock
);
1122 cmd
->stats
= *stats
;
1123 up_write(&cmd
->root_lock
);
1126 int dm_cache_commit(struct dm_cache_metadata
*cmd
, bool clean_shutdown
)
1129 flags_mutator mutator
= (clean_shutdown
? set_clean_shutdown
:
1130 clear_clean_shutdown
);
1132 down_write(&cmd
->root_lock
);
1133 r
= __commit_transaction(cmd
, mutator
);
1137 r
= __begin_transaction(cmd
);
1140 up_write(&cmd
->root_lock
);
1144 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata
*cmd
,
1149 down_read(&cmd
->root_lock
);
1150 r
= dm_sm_get_nr_free(cmd
->metadata_sm
, result
);
1151 up_read(&cmd
->root_lock
);
1156 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata
*cmd
,
1161 down_read(&cmd
->root_lock
);
1162 r
= dm_sm_get_nr_blocks(cmd
->metadata_sm
, result
);
1163 up_read(&cmd
->root_lock
);
1168 /*----------------------------------------------------------------*/
1170 static int begin_hints(struct dm_cache_metadata
*cmd
, struct dm_cache_policy
*policy
)
1175 const char *policy_name
= dm_cache_policy_get_name(policy
);
1176 const unsigned *policy_version
= dm_cache_policy_get_version(policy
);
1178 if (!policy_name
[0] ||
1179 (strlen(policy_name
) > sizeof(cmd
->policy_name
) - 1))
1182 if (!policy_unchanged(cmd
, policy
)) {
1183 strncpy(cmd
->policy_name
, policy_name
, sizeof(cmd
->policy_name
));
1184 memcpy(cmd
->policy_version
, policy_version
, sizeof(cmd
->policy_version
));
1186 hint_size
= dm_cache_policy_get_hint_size(policy
);
1188 return 0; /* short-circuit hints initialization */
1189 cmd
->policy_hint_size
= hint_size
;
1191 if (cmd
->hint_root
) {
1192 r
= dm_array_del(&cmd
->hint_info
, cmd
->hint_root
);
1197 r
= dm_array_empty(&cmd
->hint_info
, &cmd
->hint_root
);
1201 value
= cpu_to_le32(0);
1202 __dm_bless_for_disk(&value
);
1203 r
= dm_array_resize(&cmd
->hint_info
, cmd
->hint_root
, 0,
1204 from_cblock(cmd
->cache_blocks
),
1205 &value
, &cmd
->hint_root
);
1213 int dm_cache_begin_hints(struct dm_cache_metadata
*cmd
, struct dm_cache_policy
*policy
)
1217 down_write(&cmd
->root_lock
);
1218 r
= begin_hints(cmd
, policy
);
1219 up_write(&cmd
->root_lock
);
1224 static int save_hint(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
,
1228 __le32 value
= cpu_to_le32(hint
);
1229 __dm_bless_for_disk(&value
);
1231 r
= dm_array_set_value(&cmd
->hint_info
, cmd
->hint_root
,
1232 from_cblock(cblock
), &value
, &cmd
->hint_root
);
1233 cmd
->changed
= true;
1238 int dm_cache_save_hint(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
,
1243 if (!hints_array_initialized(cmd
))
1246 down_write(&cmd
->root_lock
);
1247 r
= save_hint(cmd
, cblock
, hint
);
1248 up_write(&cmd
->root_lock
);
1253 int dm_cache_metadata_all_clean(struct dm_cache_metadata
*cmd
, bool *result
)
1255 return blocks_are_unmapped_or_clean(cmd
, 0, cmd
->cache_blocks
, result
);