ext4: record the checksum algorithm in use in the superblock

Record the type of checksum algorithm we're using for metadata in the
superblock, in case we ever want/need to change the algorithm.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Darrick J. Wong 2012-04-29 18:25:10 -04:00 committed by Theodore Ts'o
parent e615391896
commit d25425f8e0

View File

@ -112,6 +112,16 @@ static struct file_system_type ext3_fs_type = {
#define IS_EXT3_SB(sb) (0)
#endif
static int ext4_verify_csum_type(struct super_block *sb,
struct ext4_super_block *es)
{
if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
return 1;
return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
}
void *ext4_kvmalloc(size_t size, gfp_t flags)
{
void *ret;
@ -3025,6 +3035,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
goto cantfind_ext4;
sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
/* Check for a known checksum algorithm */
if (!ext4_verify_csum_type(sb, es)) {
ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
"unknown checksum algorithm.");
silent = 1;
goto cantfind_ext4;
}
/* Set defaults before we parse the mount options */
def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
set_opt(sb, INIT_INODE_TABLE);