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_dblock_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_dblock(cmd
->discard_nr_blocks
));
333 disk_super
->metadata_block_size
= cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE
);
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 /* Verify the data block size hasn't changed */
429 if (le32_to_cpu(disk_super
->data_block_size
) != cmd
->data_block_size
) {
430 DMERR("changing the data block size (from %u to %llu) is not supported",
431 le32_to_cpu(disk_super
->data_block_size
),
432 (unsigned long long)cmd
->data_block_size
);
437 r
= __check_incompat_features(disk_super
, cmd
);
441 r
= dm_tm_open_with_sm(cmd
->bm
, CACHE_SUPERBLOCK_LOCATION
,
442 disk_super
->metadata_space_map_root
,
443 sizeof(disk_super
->metadata_space_map_root
),
444 &cmd
->tm
, &cmd
->metadata_sm
);
446 DMERR("tm_open_with_sm failed");
450 __setup_mapping_info(cmd
);
451 dm_disk_bitset_init(cmd
->tm
, &cmd
->discard_info
);
452 sb_flags
= le32_to_cpu(disk_super
->flags
);
453 cmd
->clean_when_opened
= test_bit(CLEAN_SHUTDOWN
, &sb_flags
);
454 return dm_bm_unlock(sblock
);
457 dm_bm_unlock(sblock
);
461 static int __open_or_format_metadata(struct dm_cache_metadata
*cmd
,
465 bool unformatted
= false;
467 r
= __superblock_all_zeroes(cmd
->bm
, &unformatted
);
472 return format_device
? __format_metadata(cmd
) : -EPERM
;
474 return __open_metadata(cmd
);
477 static int __create_persistent_data_objects(struct dm_cache_metadata
*cmd
,
478 bool may_format_device
)
481 cmd
->bm
= dm_block_manager_create(cmd
->bdev
, DM_CACHE_METADATA_BLOCK_SIZE
<< SECTOR_SHIFT
,
482 CACHE_METADATA_CACHE_SIZE
,
483 CACHE_MAX_CONCURRENT_LOCKS
);
484 if (IS_ERR(cmd
->bm
)) {
485 DMERR("could not create block manager");
486 return PTR_ERR(cmd
->bm
);
489 r
= __open_or_format_metadata(cmd
, may_format_device
);
491 dm_block_manager_destroy(cmd
->bm
);
496 static void __destroy_persistent_data_objects(struct dm_cache_metadata
*cmd
)
498 dm_sm_destroy(cmd
->metadata_sm
);
499 dm_tm_destroy(cmd
->tm
);
500 dm_block_manager_destroy(cmd
->bm
);
503 typedef unsigned long (*flags_mutator
)(unsigned long);
505 static void update_flags(struct cache_disk_superblock
*disk_super
,
506 flags_mutator mutator
)
508 uint32_t sb_flags
= mutator(le32_to_cpu(disk_super
->flags
));
509 disk_super
->flags
= cpu_to_le32(sb_flags
);
512 static unsigned long set_clean_shutdown(unsigned long flags
)
514 set_bit(CLEAN_SHUTDOWN
, &flags
);
518 static unsigned long clear_clean_shutdown(unsigned long flags
)
520 clear_bit(CLEAN_SHUTDOWN
, &flags
);
524 static void read_superblock_fields(struct dm_cache_metadata
*cmd
,
525 struct cache_disk_superblock
*disk_super
)
527 cmd
->root
= le64_to_cpu(disk_super
->mapping_root
);
528 cmd
->hint_root
= le64_to_cpu(disk_super
->hint_root
);
529 cmd
->discard_root
= le64_to_cpu(disk_super
->discard_root
);
530 cmd
->discard_block_size
= le64_to_cpu(disk_super
->discard_block_size
);
531 cmd
->discard_nr_blocks
= to_dblock(le64_to_cpu(disk_super
->discard_nr_blocks
));
532 cmd
->data_block_size
= le32_to_cpu(disk_super
->data_block_size
);
533 cmd
->cache_blocks
= to_cblock(le32_to_cpu(disk_super
->cache_blocks
));
534 strncpy(cmd
->policy_name
, disk_super
->policy_name
, sizeof(cmd
->policy_name
));
535 cmd
->policy_version
[0] = le32_to_cpu(disk_super
->policy_version
[0]);
536 cmd
->policy_version
[1] = le32_to_cpu(disk_super
->policy_version
[1]);
537 cmd
->policy_version
[2] = le32_to_cpu(disk_super
->policy_version
[2]);
538 cmd
->policy_hint_size
= le32_to_cpu(disk_super
->policy_hint_size
);
540 cmd
->stats
.read_hits
= le32_to_cpu(disk_super
->read_hits
);
541 cmd
->stats
.read_misses
= le32_to_cpu(disk_super
->read_misses
);
542 cmd
->stats
.write_hits
= le32_to_cpu(disk_super
->write_hits
);
543 cmd
->stats
.write_misses
= le32_to_cpu(disk_super
->write_misses
);
545 cmd
->changed
= false;
549 * The mutator updates the superblock flags.
551 static int __begin_transaction_flags(struct dm_cache_metadata
*cmd
,
552 flags_mutator mutator
)
555 struct cache_disk_superblock
*disk_super
;
556 struct dm_block
*sblock
;
558 r
= superblock_lock(cmd
, &sblock
);
562 disk_super
= dm_block_data(sblock
);
563 update_flags(disk_super
, mutator
);
564 read_superblock_fields(cmd
, disk_super
);
565 dm_bm_unlock(sblock
);
567 return dm_bm_flush(cmd
->bm
);
570 static int __begin_transaction(struct dm_cache_metadata
*cmd
)
573 struct cache_disk_superblock
*disk_super
;
574 struct dm_block
*sblock
;
577 * We re-read the superblock every time. Shouldn't need to do this
580 r
= superblock_read_lock(cmd
, &sblock
);
584 disk_super
= dm_block_data(sblock
);
585 read_superblock_fields(cmd
, disk_super
);
586 dm_bm_unlock(sblock
);
591 static int __commit_transaction(struct dm_cache_metadata
*cmd
,
592 flags_mutator mutator
)
595 struct cache_disk_superblock
*disk_super
;
596 struct dm_block
*sblock
;
599 * We need to know if the cache_disk_superblock exceeds a 512-byte sector.
601 BUILD_BUG_ON(sizeof(struct cache_disk_superblock
) > 512);
603 r
= dm_bitset_flush(&cmd
->discard_info
, cmd
->discard_root
,
608 r
= dm_tm_pre_commit(cmd
->tm
);
612 r
= __save_sm_root(cmd
);
616 r
= superblock_lock(cmd
, &sblock
);
620 disk_super
= dm_block_data(sblock
);
623 update_flags(disk_super
, mutator
);
625 disk_super
->mapping_root
= cpu_to_le64(cmd
->root
);
626 disk_super
->hint_root
= cpu_to_le64(cmd
->hint_root
);
627 disk_super
->discard_root
= cpu_to_le64(cmd
->discard_root
);
628 disk_super
->discard_block_size
= cpu_to_le64(cmd
->discard_block_size
);
629 disk_super
->discard_nr_blocks
= cpu_to_le64(from_dblock(cmd
->discard_nr_blocks
));
630 disk_super
->cache_blocks
= cpu_to_le32(from_cblock(cmd
->cache_blocks
));
631 strncpy(disk_super
->policy_name
, cmd
->policy_name
, sizeof(disk_super
->policy_name
));
632 disk_super
->policy_version
[0] = cpu_to_le32(cmd
->policy_version
[0]);
633 disk_super
->policy_version
[1] = cpu_to_le32(cmd
->policy_version
[1]);
634 disk_super
->policy_version
[2] = cpu_to_le32(cmd
->policy_version
[2]);
636 disk_super
->read_hits
= cpu_to_le32(cmd
->stats
.read_hits
);
637 disk_super
->read_misses
= cpu_to_le32(cmd
->stats
.read_misses
);
638 disk_super
->write_hits
= cpu_to_le32(cmd
->stats
.write_hits
);
639 disk_super
->write_misses
= cpu_to_le32(cmd
->stats
.write_misses
);
640 __copy_sm_root(cmd
, disk_super
);
642 return dm_tm_commit(cmd
->tm
, sblock
);
645 /*----------------------------------------------------------------*/
648 * The mappings are held in a dm-array that has 64-bit values stored in
649 * little-endian format. The index is the cblock, the high 48bits of the
650 * value are the oblock and the low 16 bit the flags.
652 #define FLAGS_MASK ((1 << 16) - 1)
654 static __le64
pack_value(dm_oblock_t block
, unsigned flags
)
656 uint64_t value
= from_oblock(block
);
658 value
= value
| (flags
& FLAGS_MASK
);
659 return cpu_to_le64(value
);
662 static void unpack_value(__le64 value_le
, dm_oblock_t
*block
, unsigned *flags
)
664 uint64_t value
= le64_to_cpu(value_le
);
665 uint64_t b
= value
>> 16;
666 *block
= to_oblock(b
);
667 *flags
= value
& FLAGS_MASK
;
670 /*----------------------------------------------------------------*/
672 struct dm_cache_metadata
*dm_cache_metadata_open(struct block_device
*bdev
,
673 sector_t data_block_size
,
674 bool may_format_device
,
675 size_t policy_hint_size
)
678 struct dm_cache_metadata
*cmd
;
680 cmd
= kzalloc(sizeof(*cmd
), GFP_KERNEL
);
682 DMERR("could not allocate metadata struct");
686 init_rwsem(&cmd
->root_lock
);
688 cmd
->data_block_size
= data_block_size
;
689 cmd
->cache_blocks
= 0;
690 cmd
->policy_hint_size
= policy_hint_size
;
693 r
= __create_persistent_data_objects(cmd
, may_format_device
);
699 r
= __begin_transaction_flags(cmd
, clear_clean_shutdown
);
701 dm_cache_metadata_close(cmd
);
708 void dm_cache_metadata_close(struct dm_cache_metadata
*cmd
)
710 __destroy_persistent_data_objects(cmd
);
715 * Checks that the given cache block is either unmapped or clean.
717 static int block_unmapped_or_clean(struct dm_cache_metadata
*cmd
, dm_cblock_t b
,
725 r
= dm_array_get_value(&cmd
->info
, cmd
->root
, from_cblock(b
), &value
);
727 DMERR("block_unmapped_or_clean failed");
731 unpack_value(value
, &ob
, &flags
);
732 *result
= !((flags
& M_VALID
) && (flags
& M_DIRTY
));
737 static int blocks_are_unmapped_or_clean(struct dm_cache_metadata
*cmd
,
738 dm_cblock_t begin
, dm_cblock_t end
,
744 while (begin
!= end
) {
745 r
= block_unmapped_or_clean(cmd
, begin
, result
);
750 DMERR("cache block %llu is dirty",
751 (unsigned long long) from_cblock(begin
));
755 begin
= to_cblock(from_cblock(begin
) + 1);
761 int dm_cache_resize(struct dm_cache_metadata
*cmd
, dm_cblock_t new_cache_size
)
765 __le64 null_mapping
= pack_value(0, 0);
767 down_write(&cmd
->root_lock
);
768 __dm_bless_for_disk(&null_mapping
);
770 if (from_cblock(new_cache_size
) < from_cblock(cmd
->cache_blocks
)) {
771 r
= blocks_are_unmapped_or_clean(cmd
, new_cache_size
, cmd
->cache_blocks
, &clean
);
773 __dm_unbless_for_disk(&null_mapping
);
778 DMERR("unable to shrink cache due to dirty blocks");
780 __dm_unbless_for_disk(&null_mapping
);
785 r
= dm_array_resize(&cmd
->info
, cmd
->root
, from_cblock(cmd
->cache_blocks
),
786 from_cblock(new_cache_size
),
787 &null_mapping
, &cmd
->root
);
789 cmd
->cache_blocks
= new_cache_size
;
793 up_write(&cmd
->root_lock
);
798 int dm_cache_discard_bitset_resize(struct dm_cache_metadata
*cmd
,
799 sector_t discard_block_size
,
800 dm_dblock_t new_nr_entries
)
804 down_write(&cmd
->root_lock
);
805 r
= dm_bitset_resize(&cmd
->discard_info
,
807 from_dblock(cmd
->discard_nr_blocks
),
808 from_dblock(new_nr_entries
),
809 false, &cmd
->discard_root
);
811 cmd
->discard_block_size
= discard_block_size
;
812 cmd
->discard_nr_blocks
= new_nr_entries
;
816 up_write(&cmd
->root_lock
);
821 static int __set_discard(struct dm_cache_metadata
*cmd
, dm_dblock_t b
)
823 return dm_bitset_set_bit(&cmd
->discard_info
, cmd
->discard_root
,
824 from_dblock(b
), &cmd
->discard_root
);
827 static int __clear_discard(struct dm_cache_metadata
*cmd
, dm_dblock_t b
)
829 return dm_bitset_clear_bit(&cmd
->discard_info
, cmd
->discard_root
,
830 from_dblock(b
), &cmd
->discard_root
);
833 static int __is_discarded(struct dm_cache_metadata
*cmd
, dm_dblock_t b
,
836 return dm_bitset_test_bit(&cmd
->discard_info
, cmd
->discard_root
,
837 from_dblock(b
), &cmd
->discard_root
,
841 static int __discard(struct dm_cache_metadata
*cmd
,
842 dm_dblock_t dblock
, bool discard
)
846 r
= (discard
? __set_discard
: __clear_discard
)(cmd
, dblock
);
854 int dm_cache_set_discard(struct dm_cache_metadata
*cmd
,
855 dm_dblock_t dblock
, bool discard
)
859 down_write(&cmd
->root_lock
);
860 r
= __discard(cmd
, dblock
, discard
);
861 up_write(&cmd
->root_lock
);
866 static int __load_discards(struct dm_cache_metadata
*cmd
,
867 load_discard_fn fn
, void *context
)
873 for (b
= 0; b
< from_dblock(cmd
->discard_nr_blocks
); b
++) {
874 dm_dblock_t dblock
= to_dblock(b
);
876 if (cmd
->clean_when_opened
) {
877 r
= __is_discarded(cmd
, dblock
, &discard
);
883 r
= fn(context
, cmd
->discard_block_size
, dblock
, discard
);
891 int dm_cache_load_discards(struct dm_cache_metadata
*cmd
,
892 load_discard_fn fn
, void *context
)
896 down_read(&cmd
->root_lock
);
897 r
= __load_discards(cmd
, fn
, context
);
898 up_read(&cmd
->root_lock
);
903 dm_cblock_t
dm_cache_size(struct dm_cache_metadata
*cmd
)
907 down_read(&cmd
->root_lock
);
908 r
= cmd
->cache_blocks
;
909 up_read(&cmd
->root_lock
);
914 static int __remove(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
)
917 __le64 value
= pack_value(0, 0);
919 __dm_bless_for_disk(&value
);
920 r
= dm_array_set_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
),
929 int dm_cache_remove_mapping(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
)
933 down_write(&cmd
->root_lock
);
934 r
= __remove(cmd
, cblock
);
935 up_write(&cmd
->root_lock
);
940 static int __insert(struct dm_cache_metadata
*cmd
,
941 dm_cblock_t cblock
, dm_oblock_t oblock
)
944 __le64 value
= pack_value(oblock
, M_VALID
);
945 __dm_bless_for_disk(&value
);
947 r
= dm_array_set_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
),
956 int dm_cache_insert_mapping(struct dm_cache_metadata
*cmd
,
957 dm_cblock_t cblock
, dm_oblock_t oblock
)
961 down_write(&cmd
->root_lock
);
962 r
= __insert(cmd
, cblock
, oblock
);
963 up_write(&cmd
->root_lock
);
972 struct dm_cache_metadata
*cmd
;
973 bool respect_dirty_flags
;
977 static bool policy_unchanged(struct dm_cache_metadata
*cmd
,
978 struct dm_cache_policy
*policy
)
980 const char *policy_name
= dm_cache_policy_get_name(policy
);
981 const unsigned *policy_version
= dm_cache_policy_get_version(policy
);
982 size_t policy_hint_size
= dm_cache_policy_get_hint_size(policy
);
985 * Ensure policy names match.
987 if (strncmp(cmd
->policy_name
, policy_name
, sizeof(cmd
->policy_name
)))
991 * Ensure policy major versions match.
993 if (cmd
->policy_version
[0] != policy_version
[0])
997 * Ensure policy hint sizes match.
999 if (cmd
->policy_hint_size
!= policy_hint_size
)
1005 static bool hints_array_initialized(struct dm_cache_metadata
*cmd
)
1007 return cmd
->hint_root
&& cmd
->policy_hint_size
;
1010 static bool hints_array_available(struct dm_cache_metadata
*cmd
,
1011 struct dm_cache_policy
*policy
)
1013 return cmd
->clean_when_opened
&& policy_unchanged(cmd
, policy
) &&
1014 hints_array_initialized(cmd
);
1017 static int __load_mapping(void *context
, uint64_t cblock
, void *leaf
)
1022 __le32 hint_value
= 0;
1025 struct thunk
*thunk
= context
;
1026 struct dm_cache_metadata
*cmd
= thunk
->cmd
;
1028 memcpy(&value
, leaf
, sizeof(value
));
1029 unpack_value(value
, &oblock
, &flags
);
1031 if (flags
& M_VALID
) {
1032 if (thunk
->hints_valid
) {
1033 r
= dm_array_get_value(&cmd
->hint_info
, cmd
->hint_root
,
1034 cblock
, &hint_value
);
1035 if (r
&& r
!= -ENODATA
)
1039 dirty
= thunk
->respect_dirty_flags
? (flags
& M_DIRTY
) : true;
1040 r
= thunk
->fn(thunk
->context
, oblock
, to_cblock(cblock
),
1041 dirty
, le32_to_cpu(hint_value
), thunk
->hints_valid
);
1047 static int __load_mappings(struct dm_cache_metadata
*cmd
,
1048 struct dm_cache_policy
*policy
,
1049 load_mapping_fn fn
, void *context
)
1054 thunk
.context
= context
;
1057 thunk
.respect_dirty_flags
= cmd
->clean_when_opened
;
1058 thunk
.hints_valid
= hints_array_available(cmd
, policy
);
1060 return dm_array_walk(&cmd
->info
, cmd
->root
, __load_mapping
, &thunk
);
1063 int dm_cache_load_mappings(struct dm_cache_metadata
*cmd
,
1064 struct dm_cache_policy
*policy
,
1065 load_mapping_fn fn
, void *context
)
1069 down_read(&cmd
->root_lock
);
1070 r
= __load_mappings(cmd
, policy
, fn
, context
);
1071 up_read(&cmd
->root_lock
);
1076 static int __dump_mapping(void *context
, uint64_t cblock
, void *leaf
)
1083 memcpy(&value
, leaf
, sizeof(value
));
1084 unpack_value(value
, &oblock
, &flags
);
1089 static int __dump_mappings(struct dm_cache_metadata
*cmd
)
1091 return dm_array_walk(&cmd
->info
, cmd
->root
, __dump_mapping
, NULL
);
1094 void dm_cache_dump(struct dm_cache_metadata
*cmd
)
1096 down_read(&cmd
->root_lock
);
1097 __dump_mappings(cmd
);
1098 up_read(&cmd
->root_lock
);
1101 int dm_cache_changed_this_transaction(struct dm_cache_metadata
*cmd
)
1105 down_read(&cmd
->root_lock
);
1107 up_read(&cmd
->root_lock
);
1112 static int __dirty(struct dm_cache_metadata
*cmd
, dm_cblock_t cblock
, bool dirty
)
1119 r
= dm_array_get_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
), &value
);
1123 unpack_value(value
, &oblock
, &flags
);
1125 if (((flags
& M_DIRTY
) && dirty
) || (!(flags
& M_DIRTY
) && !dirty
))
1126 /* nothing to be done */
1129 value
= pack_value(oblock
, (flags
& ~M_DIRTY
) | (dirty
? M_DIRTY
: 0));
1130 __dm_bless_for_disk(&value
);
1132 r
= dm_array_set_value(&cmd
->info
, cmd
->root
, from_cblock(cblock
),
1133 &value
, &cmd
->root
);
1137 cmd
->changed
= true;
1142 int dm_cache_set_dirty(struct dm_cache_metadata
*cmd
,
1143 dm_cblock_t cblock
, bool dirty
)
1147 down_write(&cmd
->root_lock
);
1148 r
= __dirty(cmd
, cblock
, dirty
);
1149 up_write(&cmd
->root_lock
);
1154 void dm_cache_metadata_get_stats(struct dm_cache_metadata
*cmd
,
1155 struct dm_cache_statistics
*stats
)
1157 down_read(&cmd
->root_lock
);
1158 *stats
= cmd
->stats
;
1159 up_read(&cmd
->root_lock
);
1162 void dm_cache_metadata_set_stats(struct dm_cache_metadata
*cmd
,
1163 struct dm_cache_statistics
*stats
)
1165 down_write(&cmd
->root_lock
);
1166 cmd
->stats
= *stats
;
1167 up_write(&cmd
->root_lock
);
1170 int dm_cache_commit(struct dm_cache_metadata
*cmd
, bool clean_shutdown
)
1173 flags_mutator mutator
= (clean_shutdown
? set_clean_shutdown
:
1174 clear_clean_shutdown
);
1176 down_write(&cmd
->root_lock
);
1177 r
= __commit_transaction(cmd
, mutator
);
1181 r
= __begin_transaction(cmd
);
1184 up_write(&cmd
->root_lock
);
1188 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata
*cmd
,
1193 down_read(&cmd
->root_lock
);
1194 r
= dm_sm_get_nr_free(cmd
->metadata_sm
, result
);
1195 up_read(&cmd
->root_lock
);
1200 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata
*cmd
,
1205 down_read(&cmd
->root_lock
);
1206 r
= dm_sm_get_nr_blocks(cmd
->metadata_sm
, result
);
1207 up_read(&cmd
->root_lock
);
1212 /*----------------------------------------------------------------*/
1214 static int begin_hints(struct dm_cache_metadata
*cmd
, struct dm_cache_policy
*policy
)
1219 const char *policy_name
= dm_cache_policy_get_name(policy
);
1220 const unsigned *policy_version
= dm_cache_policy_get_version(policy
);
1222 if (!policy_name
[0] ||
1223 (strlen(policy_name
) > sizeof(cmd
->policy_name
) - 1))
1226 if (!policy_unchanged(cmd
, policy
)) {
1227 strncpy(cmd
->policy_name
, policy_name
, sizeof(cmd
->policy_name
));
1228 memcpy(cmd
->policy_version
, policy_version
, sizeof(cmd
->policy_version
));
1230 hint_size
= dm_cache_policy_get_hint_size(policy
);
1232 return 0; /* short-circuit hints initialization */
1233 cmd
->policy_hint_size
= hint_size
;
1235 if (cmd
->hint_root
) {
1236 r
= dm_array_del(&cmd
->hint_info
, cmd
->hint_root
);
1241 r
= dm_array_empty(&cmd
->hint_info
, &cmd
->hint_root
);
1245 value
= cpu_to_le32(0);
1246 __dm_bless_for_disk(&value
);
1247 r
= dm_array_resize(&cmd
->hint_info
, cmd
->hint_root
, 0,
1248 from_cblock(cmd
->cache_blocks
),
1249 &value
, &cmd
->hint_root
);
1257 static int save_hint(void *context
, dm_cblock_t cblock
, dm_oblock_t oblock
, uint32_t hint
)
1259 struct dm_cache_metadata
*cmd
= context
;
1260 __le32 value
= cpu_to_le32(hint
);
1263 __dm_bless_for_disk(&value
);
1265 r
= dm_array_set_value(&cmd
->hint_info
, cmd
->hint_root
,
1266 from_cblock(cblock
), &value
, &cmd
->hint_root
);
1267 cmd
->changed
= true;
1272 static int write_hints(struct dm_cache_metadata
*cmd
, struct dm_cache_policy
*policy
)
1276 r
= begin_hints(cmd
, policy
);
1278 DMERR("begin_hints failed");
1282 return policy_walk_mappings(policy
, save_hint
, cmd
);
1285 int dm_cache_write_hints(struct dm_cache_metadata
*cmd
, struct dm_cache_policy
*policy
)
1289 down_write(&cmd
->root_lock
);
1290 r
= write_hints(cmd
, policy
);
1291 up_write(&cmd
->root_lock
);
1296 int dm_cache_metadata_all_clean(struct dm_cache_metadata
*cmd
, bool *result
)
1298 return blocks_are_unmapped_or_clean(cmd
, 0, cmd
->cache_blocks
, result
);