From:   "Frank Filz" <ffilzlnx@mindspring.com>
To:     "'Bruce Fields'" <bfields@redhat.com>, <trondmy@kernel.org>
Cc:     "'Chuck Lever'" <chuck.lever@oracle.com>,
        "'Linux NFS Mailing List'" <linux-nfs@vger.kernel.org>
Subject: pynfs V3 ideas - WAS: [PATCH 5/9] nfsd: NFSv3 should allow zero length writes
Date:   Mon, 20 Dec 2021 09:42:07 -0800
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> On Fri, Dec 17, 2021 at 5:07 PM <trondmy@kernel.org> wrote:
> >
> > From: Trond Myklebust <trond.myklebust@hammerspace.com>
> >
> > According to RFC1813: "If count is 0, the WRITE will succeed and
> > return a count of 0, barring errors due to permissions checking."
>=20
> Yes, I'm surprised we're not already doing this right.
>=20
> I wonder how far back this bug goes.
>=20
> The svc.c code is from 8154ef2776aa "NFSD: Clean up legacy NFS WRITE
> argument XDR decoders", but the behavior might predate that code.  The
> nfsd_vfs_write() logic, I'm not sure I understand.
>=20
> We have a pynfs test for the v4 case (WRT4), but I guess we must have =
nothing
> testing the v3 case.

Hmm, need to try and remember this... I am slowly working on pnfs V3 =
test cases so I will try and make sure edge cases like this get tested.

Frank