On Wed, Jun 12, 2013 at 08:04:41PM -0500, Ben Myers wrote: > Hey Dave, > > On Wed, Jun 12, 2013 at 12:19:06PM +1000, Dave Chinner wrote: > > From: Dave Chinner <dchinner@xxxxxxxxxx> > > > > Unfortunately, we cannot guarantee that items logged multiple times > > and replayed by log recovery do not take objects back in time. When > > theya re taken back in time, the go into an intermediate state which > > is corrupt, and hence verification that occurs on this intermediate > > state causes log recovery to abort with a corruption shutdown. > > > > Instead of causing a shutdown and unmountable filesystem, don't > > verify post-recovery items before they are written to disk. This is > > less than optimal, but there is no way to detect this issue for > > non-CRC filesystems If log recovery successfully completes, this > > will be undone and the object will be consistent by subsequent > > transactions that are replayed, so in most cases we don't need to > > take drastic action. > > > > For CRC enabled filesystems, leave the verifiers in place - we need > > to call them to recalculate the CRCs on the objects anyway. This > > recovery problem canbe solved for such filesystems - we have a LSN > > stamped in all metadata at writeback time that we can to determine > > whether the item should be replayed or not. This is a separate piece > > of work, so is not addressed by this patch. > > Is there a test case for this one? How are you reproducing this? The test case was Dave Jones running sysrq-b on a hung test machine. The machine would occasionally end up with a corrupt home directory. http://oss.sgi.com/pipermail/xfs/2013-May/026759.html Analysis from a metdadump provided by Dave: http://oss.sgi.com/pipermail/xfs/2013-June/026965.html And Cai also appeared to be hitting this after a crash on 3.10-rc4, as it's giving exactly the same "verifier failed during log recovery" stack trace: http://oss.sgi.com/pipermail/xfs/2013-June/026889.html Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
