| Message ID | 200811032037.mA3Kbud5019550@imap1.linux-foundation.org |
|---|---|
| State | Accepted, archived |
| Headers | show |
diff -puN fs/ext3/super.c~ext3-wait-on-all-pending-commits-in-ext3_sync_fs fs/ext3/super.c --- a/fs/ext3/super.c~ext3-wait-on-all-pending-commits-in-ext3_sync_fs +++ a/fs/ext3/super.c @@ -2390,13 +2390,12 @@ static void ext3_write_super (struct sup static int ext3_sync_fs(struct super_block *sb, int wait) { - tid_t target; - sb->s_dirt = 0; - if (journal_start_commit(EXT3_SB(sb)->s_journal, &target)) { - if (wait) - log_wait_commit(EXT3_SB(sb)->s_journal, target); - } + if (wait) + ext3_force_commit(sb); + else + journal_start_commit(EXT3_SB(sb)->s_journal, NULL); + return 0; }
The patch titled ext3: wait on all pending commits in ext3_sync_fs has been added to the -mm tree. Its filename is ext3-wait-on-all-pending-commits-in-ext3_sync_fs.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: ext3: wait on all pending commits in ext3_sync_fs From: Arthur Jones <ajones@riverbed.com> In ext3_sync_fs, we only wait for a commit to finish if we started it, but there may be one already in progress which will not be synced. In the case of a data=ordered umount with pending long symlinks which are delayed due to a long list of other I/O on the backing block device, this causes the buffer associated with the long symlinks to not be moved to the inode dirty list in the second phase of fsync_super. Then, before they can be dirtied again, kjournald exits, seeing the UMOUNT flag and the dirty pages are never written to the backing block device, causing long symlink corruption and exposing new or previously freed block data to userspace. This can be reproduced with a script created by Eric Sandeen <sandeen@redhat.com>: #!/bin/bash umount /mnt/test2 mount /dev/sdb4 /mnt/test2 rm -f /mnt/test2/* dd if=/dev/zero of=/mnt/test2/bigfile bs=1M count=512 touch /mnt/test2/thisisveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename ln -s /mnt/test2/thisisveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename /mnt/test2/link umount /mnt/test2 mount /dev/sdb4 /mnt/test2 ls /mnt/test2/ umount /mnt/test2 To ensure all commits are synced, we flush all journal commits now when sync_fs'ing ext3. Signed-off-by: Arthur Jones <ajones@riverbed.com> Eric Sandeen <sandeen@redhat.com> Cc: <linux-ext4@vger.kernel.org> Cc: <stable@kernel.org> [2.6.everything] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- fs/ext3/super.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)