Re: [PATCH 00/29] fs: require filesystems to explicitly opt-in to nfsd export support

Jeff Layton
2026-01-15T18:29:48Z

On Thu, 2026-01-15 at 19:17 +0100, Amir Goldstein wrote:
> On Thu, Jan 15, 2026 at 6:48 PM Jeff Layton <jlayton@kernel.org> wrote:
> >
> > In recent years, a number of filesystems that can't present stable
> > filehandles have grown struct export_operations. They've mostly done
> > this for local use-cases (enabling open_by_handle_at() and the like).
> > Unfortunately, having export_operations is generally sufficient to make
> > a filesystem be considered exportable via nfsd, but that requires that
> > the server present stable filehandles.
>
> Where does the term "stable file handles" come from? and what does it mean?
> Why not "persistent handles", which is described in NFS and SMB specs?
>
> Not to mention that EXPORT_OP_PERSISTENT_HANDLES was Acked
> by both Christoph and Christian:
>
> https://lore.kernel.org/linux-fsdevel/20260115-rundgang-leihgabe-12018e93c00c@brauner/
>
> Am I missing anything?
>

This was Chuck's suggested name. His point was that STABLE means that
the FH's don't change during the lifetime of the file.

I don't much care about the flag name, so if everyone likes PERSISTENT
better I'll roll with that.

Also, on the ovl patch: will fix...

Thanks for the review!
--
Jeff Layton <jlayton@kernel.org>