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| author | Daeho Jeong <daeho.jeong@samsung.com> | 2016-07-04 00:51:39 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2016-07-04 00:51:39 +0300 |
| commit | b47820edd1634dc1208f9212b7ecfb4230610a23 (patch) | |
| tree | 7d02e4756db46ae94ec43fdcd1adfd38156e34a5 /fs/ext4/inode.c | |
| parent | f70749ca42943faa4d4dcce46dfdcaadb1d0c4b6 (diff) | |
| download | linux-b47820edd1634dc1208f9212b7ecfb4230610a23.tar.xz | |
ext4: avoid modifying checksum fields directly during checksum verification
We temporally change checksum fields in buffers of some types of
metadata into '0' for verifying the checksum values. By doing this
without locking the buffer, some metadata's checksums, which are
being committed or written back to the storage, could be damaged.
In our test, several metadata blocks were found with damaged metadata
checksum value during recovery process. When we only verify the
checksum value, we have to avoid modifying checksum fields directly.
Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/ext4/inode.c')
| -rw-r--r-- | fs/ext4/inode.c | 38 |
1 files changed, 22 insertions, 16 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index f7140ca66e3b..44ee5d933b36 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -51,25 +51,31 @@ static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw, struct ext4_inode_info *ei) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); - __u16 csum_lo; - __u16 csum_hi = 0; __u32 csum; + __u16 dummy_csum = 0; + int offset = offsetof(struct ext4_inode, i_checksum_lo); + unsigned int csum_size = sizeof(dummy_csum); - csum_lo = le16_to_cpu(raw->i_checksum_lo); - raw->i_checksum_lo = 0; - if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && - EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) { - csum_hi = le16_to_cpu(raw->i_checksum_hi); - raw->i_checksum_hi = 0; - } + csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw, offset); + csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, csum_size); + offset += csum_size; + csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset, + EXT4_GOOD_OLD_INODE_SIZE - offset); - csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw, - EXT4_INODE_SIZE(inode->i_sb)); - - raw->i_checksum_lo = cpu_to_le16(csum_lo); - if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && - EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) - raw->i_checksum_hi = cpu_to_le16(csum_hi); + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { + offset = offsetof(struct ext4_inode, i_checksum_hi); + csum = ext4_chksum(sbi, csum, (__u8 *)raw + + EXT4_GOOD_OLD_INODE_SIZE, + offset - EXT4_GOOD_OLD_INODE_SIZE); + if (EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) { + csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, + csum_size); + offset += csum_size; + csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset, + EXT4_INODE_SIZE(inode->i_sb) - + offset); + } + } return csum; } |