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| author | Eryu Guan <guaneryu@gmail.com> | 2015-07-04 00:03:44 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-08-03 09:29:53 -0700 |
| commit | b77d9a0f566ebc43ff32d5f2fa1b7923ddf0cbff (patch) | |
| tree | afaee8470ee9141f49c6ff374d3bb739a6bb8f46 /fs | |
| parent | 054f1c39fdd689d01a61148fd5011bf5492cc399 (diff) | |
ext4: correctly migrate a file with a hole at the beginning
commit 8974fec7d72e3e02752fe0f27b4c3719c78d9a15 upstream.
Currently ext4_ind_migrate() doesn't correctly handle a file which
contains a hole at the beginning of the file. This caused the migration
to be done incorrectly, and then if there is a subsequent following
delayed allocation write to the "hole", this would reclaim the same data
blocks again and results in fs corruption.
# assmuing 4k block size ext4, with delalloc enabled
# skip the first block and write to the second block
xfs_io -fc "pwrite 4k 4k" -c "fsync" /mnt/ext4/testfile
# converting to indirect-mapped file, which would move the data blocks
# to the beginning of the file, but extent status cache still marks
# that region as a hole
chattr -e /mnt/ext4/testfile
# delayed allocation writes to the "hole", reclaim the same data block
# again, results in i_blocks corruption
xfs_io -c "pwrite 0 4k" /mnt/ext4/testfile
umount /mnt/ext4
e2fsck -nf /dev/sda6
...
Inode 53, i_blocks is 16, should be 8. Fix? no
...
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/migrate.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c index 05f84144fdd8..be92ed2609bc 100644 --- a/fs/ext4/migrate.c +++ b/fs/ext4/migrate.c @@ -616,7 +616,7 @@ int ext4_ind_migrate(struct inode *inode) struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_extent *ex; unsigned int i, len; - ext4_lblk_t end; + ext4_lblk_t start, end; ext4_fsblk_t blk; handle_t *handle; int ret; @@ -655,11 +655,12 @@ int ext4_ind_migrate(struct inode *inode) goto errout; } if (eh->eh_entries == 0) - blk = len = 0; + blk = len = start = end = 0; else { len = le16_to_cpu(ex->ee_len); blk = ext4_ext_pblock(ex); - end = le32_to_cpu(ex->ee_block) + len - 1; + start = le32_to_cpu(ex->ee_block); + end = start + len - 1; if (end >= EXT4_NDIR_BLOCKS) { ret = -EOPNOTSUPP; goto errout; @@ -668,7 +669,7 @@ int ext4_ind_migrate(struct inode *inode) ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); memset(ei->i_data, 0, sizeof(ei->i_data)); - for (i=0; i < len; i++) + for (i = start; i <= end; i++) ei->i_data[i] = cpu_to_le32(blk++); ext4_mark_inode_dirty(handle, inode); errout: |