From: Trond Myklebust <trond.myklebust@fys.uio.no>
Subject: Re: [NFS] Missing handling for NFS4ERR_OLD_STATEID
	in	nfs4_handle_exception?
Date: Thu, 12 Apr 2007 13:31:04 -0400
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To: Jeff Layton <jlayton@poochiereds.net>
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On Thu, 2007-04-12 at 07:59 -0400, Jeff Layton wrote:

> This sounds sort of like addressing the symptom and not the real 
> problem, however. The real question ought to be why you're getting 
> OLD_STATEID errors back from the server here. There can be legit 
> reasons, but these errors ought to be fairly rare. I generally only have 
> seen them when processes are signalled while RPC requests are in flight.

OLD_STATEID usually occurs if an OPEN or an OPEN_DOWNGRADE gets sent
that changes the current stateid while a READ or WRITE to the same file
is in flight.

It is generally a rare event, and so it tends to be much easier to deal
with by simply resending the READ/WRITEs with the updated stateid rather
than adding an expensive locking scheme for excluding READ/WRITE while
the OPEN/OPEN_DOWNGRADE is in progress.

Cheers,
  Trond