diff options
Diffstat (limited to 'drivers/md/dm-cache-metadata.c')
| -rw-r--r-- | drivers/md/dm-cache-metadata.c | 104 |
1 files changed, 97 insertions, 7 deletions
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index 1af7255..9ef0752 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -20,7 +20,13 @@ #define CACHE_SUPERBLOCK_MAGIC 06142003 #define CACHE_SUPERBLOCK_LOCATION 0 -#define CACHE_VERSION 1 + +/* + * defines a range of metadata versions that this module can handle. + */ +#define MIN_CACHE_VERSION 1 +#define MAX_CACHE_VERSION 1 + #define CACHE_METADATA_CACHE_SIZE 64 /* @@ -134,6 +140,18 @@ static void sb_prepare_for_write(struct dm_block_validator *v, SUPERBLOCK_CSUM_XOR)); } +static int check_metadata_version(struct cache_disk_superblock *disk_super) +{ + uint32_t metadata_version = le32_to_cpu(disk_super->version); + if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) { + DMERR("Cache metadata version %u found, but only versions between %u and %u supported.", + metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION); + return -EINVAL; + } + + return 0; +} + static int sb_check(struct dm_block_validator *v, struct dm_block *b, size_t sb_block_size) @@ -164,7 +182,7 @@ static int sb_check(struct dm_block_validator *v, return -EILSEQ; } - return 0; + return check_metadata_version(disk_super); } static struct dm_block_validator sb_validator = { @@ -198,7 +216,7 @@ static int superblock_lock(struct dm_cache_metadata *cmd, /*----------------------------------------------------------------*/ -static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result) +static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result) { int r; unsigned i; @@ -214,10 +232,10 @@ static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result) return r; data_le = dm_block_data(b); - *result = 1; + *result = true; for (i = 0; i < sb_block_size; i++) { if (data_le[i] != zero) { - *result = 0; + *result = false; break; } } @@ -270,7 +288,7 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd) disk_super->flags = 0; memset(disk_super->uuid, 0, sizeof(disk_super->uuid)); disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC); - disk_super->version = cpu_to_le32(CACHE_VERSION); + disk_super->version = cpu_to_le32(MAX_CACHE_VERSION); memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name)); memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version)); disk_super->policy_hint_size = 0; @@ -411,7 +429,8 @@ bad: static int __open_or_format_metadata(struct dm_cache_metadata *cmd, bool format_device) { - int r, unformatted; + int r; + bool unformatted = false; r = __superblock_all_zeroes(cmd->bm, &unformatted); if (r) @@ -666,19 +685,85 @@ void dm_cache_metadata_close(struct dm_cache_metadata *cmd) kfree(cmd); } +/* + * Checks that the given cache block is either unmapped or clean. + */ +static int block_unmapped_or_clean(struct dm_cache_metadata *cmd, dm_cblock_t b, + bool *result) +{ + int r; + __le64 value; + dm_oblock_t ob; + unsigned flags; + + r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value); + if (r) { + DMERR("block_unmapped_or_clean failed"); + return r; + } + + unpack_value(value, &ob, &flags); + *result = !((flags & M_VALID) && (flags & M_DIRTY)); + + return 0; +} + +static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd, + dm_cblock_t begin, dm_cblock_t end, + bool *result) +{ + int r; + *result = true; + + while (begin != end) { + r = block_unmapped_or_clean(cmd, begin, result); + if (r) + return r; + + if (!*result) { + DMERR("cache block %llu is dirty", + (unsigned long long) from_cblock(begin)); + return 0; + } + + begin = to_cblock(from_cblock(begin) + 1); + } + + return 0; +} + int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size) { int r; + bool clean; __le64 null_mapping = pack_value(0, 0); down_write(&cmd->root_lock); __dm_bless_for_disk(&null_mapping); + + if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) { + r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean); + if (r) { + __dm_unbless_for_disk(&null_mapping); + goto out; + } + + if (!clean) { + DMERR("unable to shrink cache due to dirty blocks"); + r = -EINVAL; + __dm_unbless_for_disk(&null_mapping); + goto out; + } + } + r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks), from_cblock(new_cache_size), &null_mapping, &cmd->root); if (!r) cmd->cache_blocks = new_cache_size; cmd->changed = true; + +out: up_write(&cmd->root_lock); return r; @@ -1182,3 +1267,8 @@ int dm_cache_save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock, return r; } + +int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result) +{ + return blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result); +} |
