[Ocfs2-devel] [PATCH RESEND] jbd2: fix ocfs2 corrupt when updating journal superblock fails

[Theodore Ts'o]

On Mon, Jun 15, 2015 at 02:27:09PM +0800, Joseph Qi wrote:
> If updating journal superblock fails after journal data has been flushed,
> the error is omitted and this will mislead the caller as a normal case.
> In ocfs2, the checkpoint will be treated successfully and the other node
> can get the lock to update. Since the sb_start is still pointing to the
> old log block, it will rewrite the journal data during journal recovery
> by the other node. Thus the new updates will be overwritten and ocfs2
> corrupts.
> So in above case we have to return the error, and ocfs2_commit_cache will
> take care of the error and prevent the other node to do update first.
> And only after recovering journal it can do the new updates.
> 
> The issue discussion mail can be found at:
> https://oss.oracle.com/pipermail/ocfs2-devel/2015-June/010856.html
> http://comments.gmane.org/gmane.comp.file-systems.ext4/48841
> 
> Reported-by: Yiwen Jiang <jiangyiwen at huawei.com>
> Signed-off-by: Joseph Qi <joseph.qi at huawei.com>
> Tested-by: Yiwen Jiang <jiangyiwen at huawei.com>
> Cc: Junxiao Bi <junxiao.bi at oracle.com>
> Cc: <stable at vger.kernel.org>

Thanks, applied.

					- Ted