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

[Dave Chinner]

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 at 1und1.de>
> Signed-off-by: Christoph Hellwig <hch at lst.de>

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

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

-- 
Dave Chinner
david at fromorbit.com