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| author | Theodore Ts'o <tytso@mit.edu> | 2008-07-26 20:34:21 +0200 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2008-07-26 20:34:21 +0200 |
| commit | 8a266467b8c4841ca994d0fe59f39e584650e3df (patch) | |
| tree | b9cde0d9ddf3d5eea87f609267b930e08024a9f1 /fs/ext4/super.c | |
| parent | ext4: Fix data corruption when writing to prealloc area (diff) | |
| download | linux-8a266467b8c4841ca994d0fe59f39e584650e3df.tar.xz linux-8a266467b8c4841ca994d0fe59f39e584650e3df.zip | |
ext4: Allow read/only mounts with corrupted block group checksums
If the block group checksums are corrupted, still allow the mount to
succeed, so e2fsck can have a chance to try to fix things up. Add
code in the remount r/w path to make sure the block group checksums
are valid before allowing the filesystem to be remounted read/write.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to '')
| -rw-r--r-- | fs/ext4/super.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index b5479b1dff14..876e1c620365 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1626,7 +1626,8 @@ static int ext4_check_descriptors(struct super_block *sb) "Checksum for group %lu failed (%u!=%u)\n", i, le16_to_cpu(ext4_group_desc_csum(sbi, i, gdp)), le16_to_cpu(gdp->bg_checksum)); - return 0; + if (!(sb->s_flags & MS_RDONLY)) + return 0; } if (!flexbg_flag) first_block += EXT4_BLOCKS_PER_GROUP(sb); @@ -2961,6 +2962,7 @@ static int ext4_remount (struct super_block * sb, int * flags, char * data) ext4_fsblk_t n_blocks_count = 0; unsigned long old_sb_flags; struct ext4_mount_options old_opts; + ext4_group_t g; int err; #ifdef CONFIG_QUOTA int i; @@ -3039,6 +3041,26 @@ static int ext4_remount (struct super_block * sb, int * flags, char * data) } /* + * Make sure the group descriptor checksums + * are sane. If they aren't, refuse to + * remount r/w. + */ + for (g = 0; g < sbi->s_groups_count; g++) { + struct ext4_group_desc *gdp = + ext4_get_group_desc(sb, g, NULL); + + if (!ext4_group_desc_csum_verify(sbi, g, gdp)) { + printk(KERN_ERR + "EXT4-fs: ext4_remount: " + "Checksum for group %lu failed (%u!=%u)\n", + g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)), + le16_to_cpu(gdp->bg_checksum)); + err = -EINVAL; + goto restore_opts; + } + } + + /* * If we have an unprocessed orphan list hanging * around from a previously readonly bdev mount, * require a full umount/remount for now. |