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| author | Joe Thornber <ejt@redhat.com> | 2013-10-16 11:59:26 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2013-11-11 17:37:49 +0100 |
| commit | 53d498198d3e8bce4287112beafc30befcba98cc (patch) | |
| tree | a12f0184d3a5505eca616e32c9b27be551f90070 /drivers/md | |
| parent | dm cache: add passthrough mode (diff) | |
| download | linux-53d498198d3e8bce4287112beafc30befcba98cc.tar.xz linux-53d498198d3e8bce4287112beafc30befcba98cc.zip | |
dm cache metadata: check the metadata version when reading the superblock
Need to check the version to verify on-disk metadata is supported.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-cache-metadata.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index 8601425436cd..9ef0752e8a08 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 = { @@ -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; |