Date:   Tue, 2 Apr 2019 12:11:16 -0400
To:     "Bradley C. Kuszmaul" <bradley.kuszmaul@oracle.com>
Cc:     linux-nfs@vger.kernel.org
Subject: Re: directory delegations
Message-ID: <20190402161116.GA2828@fieldses.org>
References: <2065755c-f888-9c62-f6e5-f143d42c51ee@oracle.com>
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From:   bfields@fieldses.org (J. Bruce Fields)
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On Mon, Apr 01, 2019 at 12:21:49PM -0400, Bradley C. Kuszmaul wrote:
> Hi, I'm the architect for Oracle's File Storage Service.   FSS is
> basically a big scalable NFS server that runs in Oracle's cloud.
> 
> Our metadata operations have higher latency than a vanilla NFS
> server (e.g., a Linux NFS server serving a XFS stored on a block
> device), and we suspect that directory delegations would make a big
> performance improvement.
> 
> I understand, however, that essentially no one implements directory
> delegations.
> 
> Can anyone fill me in on the current thinking of the future of
> support for directory delegations in the Linux NFS client?

Maybe somebody else will speak up, but I don't know of any effort to
implement directory delegations.

What metadata operations specifically are you worried about?  The
directory delegations that are specified in RFC 5661 are read-only.
Which might explain some of the lack of interest.

But there may be other steps that we could take to improve matters.

--b.