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
);