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dm cache metadata: check the metadata version when reading the superblock

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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>
This commit is contained in:
Joe Thornber 2013-10-16 10:59:26 +01:00 committed by Mike Snitzer
parent 2ee57d5873
commit 53d498198d
1 changed files with 21 additions and 3 deletions
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24
drivers/md/dm-cache-metadata.c
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@ -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;