Received-SPF: pass (google.com: domain of linux-nfs+bounces-1308-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Precedence: bulk
MIME-Version: 1.0
References: <CALXu0UeGr80OzF7abqxwR5KFJFhpCuomy2_tdFESAKSiW70jfA@mail.gmail.com>
 <CALXu0UcT4gG8xEVOvK1mshMDa_hKYu7rJK2biq8==ySOXdA3+w@mail.gmail.com>
 <4F5C3573-2962-4072-ACB1-1CB8236866D5@oracle.com> <CALXu0Uf2z3um+kh=tgnqskr-ZdY2gU=185K3Amr=F_GJpb2_UQ@mail.gmail.com>
 <FD981B2C-5C24-4349-A279-C70F640C0A01@oracle.com> <CANH4o6O=ihW7ENc-BTBXR4d4JL0QJjZa5YdYaKAdoHdq9vwGcA@mail.gmail.com>
 <5DA015E1-50C6-4F56-B4E7-62A4BE90DBA4@oracle.com> <CALXu0UcLV-KZ4GNY8UgWCwiUOO_HsH=KLWOKuWJ2uEDP+a9sqw@mail.gmail.com>
In-Reply-To: <CALXu0UcLV-KZ4GNY8UgWCwiUOO_HsH=KLWOKuWJ2uEDP+a9sqw@mail.gmail.com>
From: Cedric Blancher <cedric.blancher@gmail.com>
Date: Wed, 24 Jan 2024 15:05:26 +0100
Message-ID: <CALXu0UcoxTNM7DnevRmPR7iKynp9RCLQvoe4uS=NVkpRiHAUTQ@mail.gmail.com>
Subject: Re: Change "hostname" to "hostport" in text-based mountd downcall Re:
 BUG in exports(5), no example for refer= Re: Examples for refer= in /etc/exports?
To: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Cc: Martin Wege <martin.l.wege@gmail.com>, Chuck Lever III <chuck.lever@oracle.com>, 
	Roland Mainz <roland.mainz@nrubsig.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Mon, 13 Nov 2023 at 02:01, Cedric Blancher <cedric.blancher@gmail.com> w=
rote:
>
> On Fri, 10 Nov 2023 at 20:17, Chuck Lever III <chuck.lever@oracle.com> wr=
ote:
> >
> >
> >
> > > On Nov 10, 2023, at 3:30 AM, Martin Wege <martin.l.wege@gmail.com> wr=
ote:
> > >
> > > On Fri, Nov 10, 2023 at 3:20=E2=80=AFAM Chuck Lever III <chuck.lever@=
oracle.com> wrote:
> > >>
> > >>> On Nov 9, 2023, at 7:47 PM, Cedric Blancher <cedric.blancher@gmail.=
com> wrote:
> > >>>
> > >>> On Fri, 10 Nov 2023 at 01:37, Chuck Lever III <chuck.lever@oracle.c=
om> wrote:
> > >>>>
> > >>>>> On Nov 9, 2023, at 7:05 PM, Cedric Blancher <cedric.blancher@gmai=
l.com> wrote:
> > >>>>>
> > >>>>> On Thu, 2 Nov 2023 at 10:51, Cedric Blancher <cedric.blancher@gma=
il.com> wrote:
> > >>>>>>
> > >>>>>> Good morning!
> > >>>>>>
> > >>>>>> Does anyone have examples of how to use the refer=3D option in /=
etc/exports?
> > >>>>>
> > >>>>> Short answer:
> > >>>>> To redirect an NFS mount from local machine /ref/baguette to
> > >>>>> /export/home/baguette on host 134.49.22.111 add this to Linux
> > >>>>> /etc/exports:
> > >>>>>
> > >>>>> /ref *(no_root_squash,refer=3D/export/home@134.49.22.111)
> > >>>>>
> > >>>>> This is basically an exports(5) manpage bug, which does not provi=
de
> > >>>>> ANY examples.
> > >>>>
> > >>>> That's because setting up a referral this way is deprecated.
> > >>>
> > >>> Why did you do that?
> > >>
> > >> The nfsref command on Linux matches the same command on Solaris.
> > >>
> > >> nfsref was added years ago to manage junctions, as part of FedFS.
> > >> The "refer=3D" export option can't do that...
> > >
> > > Where in the kernel is the code for the refer=3D option? I'd like to =
get
> > > some of my students to contribute support for custom NFS ports.
> >
> > IIRC supporting ports is one thing we can't do right now because
> > the mountd downcall interface is text-based, and its parser can
> > barely handle "refer=3D", let alone specifying a port.
>
> I had a chat this weekend with Roland Mainz (who works on the NFSv4
> driver for Windows these days):
> ...
> That is the old mistake to think that "hostname" and "port" are
> separate entities. We had this kind of debate at SUN/MPK17 several
> times. Host and TCP port are the "location of the server", and they
> are inseparable.
> ...
> The RFCs even help out with that one, for example RFC1738 (URL RFC)
> defines a "hostport" in Page 18.
> And that's what I actually did for ms-nfs41-client: NIH&Institute
> Pasteur needed custom TCP server ports, and I implemented this by
> changing the communication of nfs41_driver.sys (kernel) to userland
> NFSv4 client daemon (nfsd_debug.exe) from "hostname" to "hostport",
> and added the port number in the UNC, so Windows always uses (and
> remembers!) the port number together with the hostname.
> Or easier: I changed "hostname" to "hostport" to embed the port number
> in the up-/downcalls for mount requests - and that is what the Linux
> people can use too.
> ...
>
> > Our plan is to replace the mountd downcall with a netlink protocol
> > that Lorenzo is working on, and then it would be very straightforward
> > to add a port to each target location. But getting to a mature
> > netlink implementation will take a while.
>
> Yeah, instead of waiting for NetLink you could implement Roland's
> suggestion, and change "hostname" to "hostport" in your test-based
> mount protocol, and technically everywhere else, like /proc/mounts and
> the /sbin/mount output.
> So instead of:
> mount -t nfs -o port=3D4444 10.10.0.10:/backups /var/backups
> you could use
> mount -t nfs 10.10.0.10@4444:/backups /var/backups
>
> The same applies to refer=3D - just change from "hostname" to
> "hostport", and the text-based mountd downcall can stay the same (e.g.
> so "foobarhost" changes to "foobarhost@444" in the mountd download.)

This issue is still open, and BURNING!

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