Re: [PATCH V12 00/12] famfs: the Fabric-Attached Memory File System (standalone)

[Darrick J. Wong]

On Thu, Aug 06, 2026 at 06:19:49AM +0100, Matthew Wilcox wrote:
> On Mon, Aug 03, 2026 at 10:52:19AM +0200, Amir Goldstein wrote:
> > > The most important thing to know about famfs is that it CANNOT be used as a
> > > general purpose file system. It is for enabling file-based byte-level access
> > > (including direct mmap) to very large (e.g. 100TB) shared/disaggregated
> > > memory appliances - which have become available during this long process,
> > > and which are in need of Linux support.
> > >
> > > So famfs cannot be used by anybody who doesn't know why they need it; Making
> > > famfs standalone means it can't affect users who don't use it. And my super-
> > > mega-corp employer (Micron), as well as other memory companies, need it.
> > > We do not intend to abandon it, but imagine if we did: fs/famfs/ should be
> > > removed if the memory companies can't be bothered to maintain it.
> > 
> > It does not work this way.
> > When vfs maintainers accept standalone famfs they accept the burden of
> > maintaining it whenever vfs internal APIs change even if the filesystem was
> > abandoned by the mega-corps.
> > That is the code of the push back for adding new filesystems.
> > Removing the fs and breaking deployed systems is not an option for the vfs
> > maintainers.
> 
> Sure it is.  We removed EFS just last month, because we decided that it
> wasn't worth keeping any more.  Just like we removed Itanium architecture
> support (and a number of other architectures before that).  We've removed
> other filesystems in the past (xiafs, ext, surely a few others).

and freevxfs just this week because the one user/complainer said hch
could let it die.

--D

> Yes, there are burdens on others by accepting this filesystem -- but if
> it's a standalone VFS filesystem, those are felt by those who work on
> the VFS.  If it's part of FUSE, then it's felt by those who work on FUSE.
> And we've already determined that those who work on FUSE are even more
> overburdened than those who work on the VFS.
> 
> famfs does not seem to be a natural fit for FUSE.  It has needs unlike any
> other Linux filesystem, and quite possibly unlike any other filesystem
> that is to come.  Rearchitecting FUSE to make famfs fit seems like a
> very dodgy proposition to me.
> 
>