lookupdotdot failing again

[A Dog]

Just an FYI update - This issue kept recurring until I did an emergency 
downgrade to 5.8 (from 6.0).  This was about two months ago at the end 
of July.  Since the downgrade I've had no lookupdotdot failure messages 
on the file server, and given the previous pattern I believe it would 
have shown up numerous times by now if the problem was present in 5.8.

Unfortunately I'm not enough of a kernel / file system hacker to start 
bisecting this, and I'm not even sure how to go about replicating it 
outside of production...  But it does seem to be related to something 
that was introduced between 5.8 and 6.0.

-- 
A Dog