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From: Cedric Blancher <cedric.blancher@gmail.com>
Date: Fri, 12 Jan 2024 06:52:00 +0100
Message-ID: <CALXu0UeCARBNQU6gVaW60J=WwdeZrQow1rPwu6jDovSBEkBh4g@mail.gmail.com>
Subject: RIP NFSv4 interoperability?! Re: NFSv4.1 mandatory locks working in
 Linux nfsd ?
To: Roland Mainz <roland.mainz@nrubsig.org>
Cc: Linux NFS Mailing List <linux-nfs@vger.kernel.org>, Jeff Layton <jlayton@kernel.org>
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On Thu, 11 Jan 2024 at 22:28, Roland Mainz <roland.mainz@nrubsig.org> wrote=
:
>
> On Thu, Jan 11, 2024 at 4:55=E2=80=AFPM Jeff Layton <jlayton@kernel.org> =
wrote:
> > On Thu, 2024-01-11 at 10:54 -0500, Jeff Layton wrote:
> > > On Sun, 2023-12-24 at 18:29 +0100, Roland Mainz wrote:
> > > > Are there any known issues with NFSv4.1 mandatory locking nfsd code=
 in
> > > > the Linux 5.10.0-22-rt-amd64 kernel (technically the Debian Bullsey=
e
> > > > RT kernel) ? Is there any kernel or NFS test suite module which cov=
ers
> > > > NFSv4.1 client mandatory locking ?
> > >
> > > Linux doesn't support mandatory locking at all since 2021 [1]. The Li=
nux
> > > NFS client and server therefore do not support v4.1 mandatory locking=
.
> >
> > Forgot the footnote!
> >
> > [1]: https://patchwork.kernel.org/project/linux-fsdevel/patch/202108201=
14046.69282-1-jlayton@kernel.org/
>
> OK, this is pretty bad in terms of interoperability.... ;-(
>
> What should a Windows NFSv4 client (Hummingbird, OpenText, Exceed,
> ms-nfs41-client, ...) do in this case ?
> It basically means that locking for these clients will fail if the
> server does not support it... ;-(

The NFSv4 server has to provide an emulation, as mandatory locking is
part of the NFSv4 protocol [1].

Although I am more, and more, and even more horrified that the once
beautiful NFSv4 design goal of a protocol for all platforms, as in
Windows, Unix, Linux, RTOS, ..., is rapidly degrading into a devolved
Linux-centric network fs, something 9p already covers, while
SMBFS/CIFS have completely taken over the market for cross-platform
network filesystems.

RIP NFSv4 ?!

[1]: <sarcasm>Of course the next NFS RFC will declare NFSv4 mandatory
locking as "obsolete", as interoperability is already covered by
SMB/CIFS and 9p</sarcasm>

Ced
--=20
Cedric Blancher <cedric.blancher@gmail.com>
[https://plus.google.com/u/0/+CedricBlancher/]
Institute Pasteur