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| author | Darrick J. Wong <djwong@us.ibm.com> | 2012-04-30 00:25:10 +0200 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-04-30 00:25:10 +0200 |
| commit | d25425f8e0ed01fc0167c043aee7e619fc3f6ab2 (patch) | |
| tree | 1c88b9de530a45bc79bf96d7acd045114cab480e | |
| parent | ext4: change on-disk layout to support extended metadata checksumming (diff) | |
| download | linux-d25425f8e0ed01fc0167c043aee7e619fc3f6ab2.tar.xz linux-d25425f8e0ed01fc0167c043aee7e619fc3f6ab2.zip | |
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>
| -rw-r--r-- | fs/ext4/super.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index e1fb1d5de58e..f489ffb3605d 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -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); |