ext4: fix same-dir rename when inline data directory overflows
commit d80d448c upstream. When performing a same-directory rename, it's possible that adding or setting the new directory entry will cause the directory to overflow the inline data area, which causes the directory to be converted to an extent-based directory. Under this circumstance it is necessary to re-read the directory when deleting the old dirent because the "old directory" context still points to i_block in the inode table, which is now an extent tree root! The delete fails with an FS error, and the subsequent fsck complains about incorrect link counts and hardlinked directories. Test case (originally found with flat_dir_test in the metadata_csum test program): # mkfs.ext4 -O inline_data /dev/sda # mount /dev/sda /mnt # mkdir /mnt/x # touch /mnt/x/changelog.gz /mnt/x/copyright /mnt/x/README.Debian # sync # for i in /mnt/x/*; do mv $i $i.longer; done # ls -la /mnt/x/ total 0 -rw-r--r-- 1 root root 0 Aug 25 12:03 changelog.gz.longer -rw-r--r-- 1 root root 0 Aug 25 12:03 copyright -rw-r--r-- 1 root root 0 Aug 25 12:03 copyright.longer -rw-r--r-- 1 root root 0 Aug 25 12:03 README.Debian.longer (Hey! Why are there four files now??) Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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