Re: [PATCH V10 00/10] famfs: port into fuse

Gregory Price
2026-04-15T13:35:01Z

On Wed, Apr 15, 2026 at 10:16:38AM +0200, David Hildenbrand (Arm) wrote:
> On 4/15/26 00:20, Gregory Price wrote:
> > On Tue, Apr 14, 2026 at 11:57:40AM -0700, Darrick J. Wong wrote:
> >>>
> >>> I very strongly object to making this a prerequisite to merging. This
> >>> is an untested idea that will certainly delay us by at least a couple
> >>> of merge windows when products are shipping now, and the existing approach
> >>> has been in circulation for a long time. It is TOO LATE!!!!!!
> >>
> > ...
> >>
> >> That said, you're clearly pissed at the goalposts changing yet again,
> >> and that's really not fair that we collectively keep moving them.
> >>
> >
> > This seems a bit more than moving a goalpost.
> >
> > We're now gating working software, for real working hardware, on a novel,
> > unproven BPF ops structure that controls page table mappings on page table
> > faults which would be used by exactly 1 user : FAMFS.
>
> Are MM people on board with even letting BPF do that? Honest question,
> if someone has a pointer to how that should work, that would be appreciated.
>

This was my first reaction when I realized the BPF program would be
controlling iomap return value in the fault path. Big ol' (!) popped
up over my head.

~Gregory