Mount NFSv4.2 filesystem in barebox?

[Martin Wege]

On Mon, Mar 3, 2025 at 9:40 AM Ahmad Fatoum <a.fatoum at pengutronix.de> wrote:
>
> Hi,
>
> On 28.02.25 11:57, Sascha Hauer wrote:
> > On Fri, Feb 21, 2025 at 12:54:00PM +0100, Martin Wege wrote:
> >> On Wed, Feb 12, 2025 at 3:33 PM Sascha Hauer <s.hauer at pengutronix.de> wrote:
> >>>
> >>> Hi Martin,
> >>>
> >>> On Tue, Feb 11, 2025 at 01:56:58PM +0100, Martin Wege wrote:
> >>>> Hello!
> >>>>
> >>>> Does barebox have support to mount a NFSv.2 filesystem?
> >>>
> >>> No, not yet. For NFSv4 we would first need TCP support. While we started
> >>> to integrate a TCP stack we are not there yet unfortunately.
> >>
> >> How long is this going to take?
> >
> > I don't think this will happen anytime soon. It's quite some work and
> > our bandwidth for adding such a feature without (paying) customer
> > demand is limited.
> >
> > That said, the lack of NFSv4 support is nagging me personally as well.
>
> We had a discussion about this last year, but it didn't result in any
> upstream code yet:
> https://lore.barebox.org/barebox/CAAvCNcCZhS8mkvdgcJ2L-eiur+OxgWEXRLnadO_HFyHfSi7WFA@mail.gmail.com/
>
> One question that I still have, is what do you use NFSv4 for?
> Is it just for development and your IT is disabling NFSv3?

No, NFSv4.1 (NFSv4.0 is obsolete due to bugs) offers better
performance, more flexibility, smaller footprint, better caching
(delegations), ACLs, SELinux support, and can be tunneled through
firewalls because it only uses TCP port 2049 and nothing else.

>
> Do you use it in the field?

Yes, we do

>
> Knowing about the use case helps with prioritizing future work.
> As it stands, NFS is mostly understood as development feature and
> it's expected so far that interested users will be able to provide
> a NFSv3 UDP server in their development network.

No, NFS is not only a development feature. For example CERN uses NFS
boot (with patched NFSv4.1 stack) in radiation environments - that
saves a SSD per embedded machine, which is typically one of the most
affected pieces from radiation. AIRBUS also uses nfsboot in their
equipment and flight deck systems.

So yes, you would have customers for NFSv4.1 support in barebox.

Thanks,
Martin