diff options
| author | Darrick J. Wong <darrick.wong@oracle.com> | 2014-10-14 02:35:49 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-14 08:47:57 -0800 |
| commit | 209f5484ef126134f2d2f322246b0e4faf3c1fbd (patch) | |
| tree | 1e786d6c9de35fadb1f92db11097d624f989341f /fs/ext4 | |
| parent | 1f1ccdde66ed867e2a71297bdb6cf1b7c6a32351 (diff) | |
| download | linux-3.10-209f5484ef126134f2d2f322246b0e4faf3c1fbd.tar.gz linux-3.10-209f5484ef126134f2d2f322246b0e4faf3c1fbd.tar.bz2 linux-3.10-209f5484ef126134f2d2f322246b0e4faf3c1fbd.zip | |
ext4: check s_chksum_driver when looking for bg csum presence
commit 813d32f91333e4c33d5a19b67167c4bae42dae75 upstream.
Convert the ext4_has_group_desc_csum predicate to look for a checksum
driver instead of the metadata_csum flag and change the bg checksum
calculation function to look for GDT_CSUM before taking the crc16
path.
Without this patch, if we mount with ^uninit_bg,^metadata_csum and
later metadata_csum gets turned on by accident, the block group
checksum functions will incorrectly assume that checksumming is
enabled (metadata_csum) but that crc16 should be used
(!s_chksum_driver). This is totally wrong, so fix the predicate
and the checksum formula selection.
(Granted, if the metadata_csum feature bit gets enabled on a live FS
then something underhanded is going on, but we could at least avoid
writing garbage into the on-disk fields.)
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/ext4.h | 4 | ||||
| -rw-r--r-- | fs/ext4/super.c | 4 |
2 files changed, 6 insertions, 2 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 3891475e22f..e4c4ac07cc3 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2261,8 +2261,8 @@ extern int ext4_register_li_request(struct super_block *sb, static inline int ext4_has_group_desc_csum(struct super_block *sb) { return EXT4_HAS_RO_COMPAT_FEATURE(sb, - EXT4_FEATURE_RO_COMPAT_GDT_CSUM | - EXT4_FEATURE_RO_COMPAT_METADATA_CSUM); + EXT4_FEATURE_RO_COMPAT_GDT_CSUM) || + (EXT4_SB(sb)->s_chksum_driver != NULL); } static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index a1b780abdf1..21a0b43a7d3 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1950,6 +1950,10 @@ static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group, } /* old crc16 code */ + if (!(sbi->s_es->s_feature_ro_compat & + cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM))) + return 0; + offset = offsetof(struct ext4_group_desc, bg_checksum); crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid)); |