Re: [PATCH V12 02/12] famfs: Module operations, fs_context, and mount

[Christian Brauner]

On Fri, Aug 28, 2026 at 12:39:56PM -0500, John Groves wrote:
> On 26/08/24 09:41AM, Miklos Szeredi wrote:
> > On Sat, 22 Aug 2026 at 23:55, John Groves <john@xxxxxxxxxx> wrote:
> > 
> > > Famfs does work in fuse, but some of the asks are things that I don't see
> > > how I can agree to. I think Miklos and I should discuss those 1:1, to figure
> > > out if there is a way forward.
> > >
> > > I think the virtual backing-dev thing is a non-starter,
> > 
> > The virtual backing-dev is an abstraction.
> > 
> > Is it sufficient for you if I promise that this is going to do the
> > same thing as the standalone famfs at the same performance level?
> > 
> > >  and I think that the famfs
> > > portion of the fuse ABI basically can't live without extents that are
> > > (daxdev, offset, length).
> > 
> > Sigh.  My proposal was (backing-id, offset, length).  Again this is an
> > abstraction.  A backing ID can be a daxdev, a striped logical device
> > or it can be a block dev or even a plain file.
> > 
> > > Also, I'm curious: if you don't know of a use case for the striping code outside
> > > of famfs, why ask famfs to completely rewrite that?  (and I agree, other
> > > than the eventual remote possibility of competing 'famfs-ng' fuse servers,
> > > I don't see much likelihood that this piece will be shared.)
> > 
> > Because the striping feature fits much better into a virtual device
> > API than the extent mapping API.  This is how striping has worked in
> > linux for the last 30 years.
> > 
> > > Miklos, I trust that you are a good faith actor, although you seem to be
> > > spread pretty thin. Can you commit to a series of 1:1 conversations with
> > > me to try to work through the disconnects?
> > 
> > Fine, let's find a time.
> > 
> > Thanks,
> > Miklos
> 
> Miklos and I met yesterday and I think we found workable path forward.
> We will be collaborating on some changes to the famfs metadata transport,
> likely mostly via me trying to make it easy for Miklos to bring up a
> famfs testbed VM, and Miklos doing some re-work on famfs to make it
> more consonant with fuse (fuse-onic? ;).

Excellent news and thanks for your patience and working with Miklos on
this.