Re: [PATCH 01/12] repair: do not walk the unlinked inode list

Dave Chinner
2011-12-12T22:55:10Z

On Fri, Dec 02, 2011 at 12:46:20PM -0500, Christoph Hellwig wrote:
> Stefan Pfetzing reported a bug where xfs_repair got stuck eating 100% CPU in
> phase3. We track it down to a loop in the unlinked inode list, apparently
> caused by memory corruption on an iSCSI target.
>
> I looked into tracking if we already saw a given unlinked inode, but given
> that we keep walking even for inodes where we can't find an allocation btree
> record that seems infeasible. On the other hand these inodes had their
> final unlink and thus were dead even before the system went down. There
> really is no point in adding them to the uncertain list and looking for
> references to them later.
>
> So the simplest fix seems to be to simply remove the unlinked inode list
> walk and just clear it - when we rebuild the inode allocation btrees these
> will simply be marked free.
>
> Reported-by: Stefan Pfetzing <stefan.pfetzing@1und1.de>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

After further consideration, this is probably fine as all the
unlinked inodes do get picked up elsewhere.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

--
Dave Chinner
david@fromorbit.com