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Message-ID: <5518fe8918715b3d1ed4547be66c3694408e9d37.camel@redhat.com>
Subject: Re: [PATCH 0/3] Handling NFSv3 I/O errors in knfsd
From:   Jeff Layton <jlayton@redhat.com>
To:     "J. Bruce Fields" <bfields@redhat.com>
Cc:     Chuck Lever <chuck.lever@oracle.com>,
        Bruce Fields <bfields@fieldses.org>,
        Trond Myklebust <trondmy@hammerspace.com>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Date:   Wed, 28 Aug 2019 11:09:59 -0400
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On Wed, 2019-08-28 at 10:40 -0400, J. Bruce Fields wrote:
> On Wed, Aug 28, 2019 at 10:16:09AM -0400, Jeff Layton wrote:
> > For the most part, these sorts of errors tend to be rare. If it turns
> > out to be a problem we could consider moving the verifier into
> > svc_export or something?
> 
> As Trond says, this isn't really a server implementation issue, it's a
> protocol issue.  If a client detects when to resend writes by storing a
> single verifier per server, then returning different verifiers from
> writes to different exports will have it resending every time it writes
> to one export then another.
> 

Huh. I've always considered the verifier to be a per-inode quantity that
we just happened to fill with a global value, but the spec _is_ a bit
vague in this regard.

I think modern Linux clients track this on a per-inode basis, but I'm
not sure about really old Linux or other clients. It'd be good to know
about BSD and Solaris, in particular.
-- 
Jeff Layton <jlayton@redhat.com>