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Date: Mon, 13 Mar 2017 12:06:32 -0400
From: "J. Bruce Fields" <bfields@redhat.com>
To: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeff Layton <jlayton@redhat.com>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: nfsd: delegation conflicts between NFSv3 and NFSv4 accessors
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On Mon, Mar 13, 2017 at 12:01:45PM -0400, J. Bruce Fields wrote:
> That wait doesn't sound bad at all.
> 
> The server could track round trip times to the clients holding
> delegations and use that to estimate the right wait time, but hopefully
> that's overkill.
> 
> I think the occasional retransmitted truncate probably isn't a big deal.
> Seems like the kind of thing the reply cache would handle well.

I haven't thought about what it'd take to implement.  Just for testing
purposes, maybe stick a 50ms wait and a retry in the JUKEBOX case in
anything under fs/nfsd/nfs3proc.c that looks like it could break a
delegation.

Jeff's proposal should also be pretty easy to prototype.

--b.