Re: [LSF/MM/BPF TOPIC] Where is fuse going? API cleanup, restructuring and more

[Amir Goldstein <amir73il@gmail.com>]

On Tue, Feb 3, 2026 at 11:15 AM Luis Henriques <luis@igalia.com> wrote:
>
> On Mon, Feb 02 2026, Amir Goldstein wrote:
>
> > [Fixed lsf-pc address typo]
> >
> > On Mon, Feb 2, 2026 at 2:51 PM Miklos Szeredi <miklos@szeredi.hu> wrote:
> >>
> >> I propose a session where various topics of interest could be
> >> discussed including but not limited to the below list
> >>
> >> New features being proposed at various stages of readiness:
> >>
> >>  - fuse4fs: exporting the iomap interface to userspace
> >>
> >>  - famfs: export distributed memory
> >>
> >>  - zero copy for fuse-io-uring
> >>
> >>  - large folios
> >>
> >>  - file handles on the userspace API
> >>
> >>  - compound requests
> >>
> >>  - BPF scripts
> >>
> >> How do these fit into the existing codebase?
> >>
> >> Cleaner separation of layers:
> >>
> >>  - transport layer: /dev/fuse, io-uring, viriofs
> >>
> >>  - filesystem layer: local fs, distributed fs
> >>
> >> Introduce new version of cleaned up API?
> >>
> >>  - remove async INIT
> >>
> >>  - no fixed ROOT_ID
> >>
> >>  - consolidate caching rules
> >>
> >>  - who's responsible for updating which metadata?
> >>
> >>  - remove legacy and problematic flags
> >>
> >>  - get rid of splice on /dev/fuse for new API version?
> >>
> >> Unresolved issues:
> >>
> >>  - locked / writeback folios vs. reclaim / page migration
> >>
> >>  - strictlimiting vs. large folios
> >
> > All important topics which I am sure will be discussed on a FUSE BoF.
>
> I wonder if the topic I proposed separately (on restarting FUSE servers)
> should also be merged into this list.  It's already a very comprehensive
> list, so I'm not sure it's worth having a separate topic if most of it
> will (likely) be touched here already.
>
> What do you think?

We are likely going to do a FUSE BoF, likely Wed afternoon,
so we can have an internal schedule for that.

Restartability and stable FUSE handles is one of the requirements
to replace an existing fs if that fs is NFS exportrable.

Thanks,
Amir.