Re: [PATCH 0/4] exportfs: add flag to allow marking export operations as only supporting file handles

[Christian Brauner]

On Wed, Dec 04, 2024 at 04:38:28PM -0800, Christoph Hellwig wrote:
> On Sun, Dec 01, 2024 at 02:12:24PM +0100, Christian Brauner wrote:
> > Hey,
> > 
> > Some filesystems like kernfs and pidfs support file handles as a
> > convenience to enable the use of name_to_handle_at(2) and
> > open_by_handle_at(2) but don't want to and cannot be reliably exported.
> > Add a flag that allows them to mark their export operations accordingly
> > and make NFS check for its presence.
> > 
> > @Amir, I'll reorder the patches such that this series comes prior to the
> > pidfs file handle series. Doing it that way will mean that there's never
> > a state where pidfs supports file handles while also being exportable.
> > It's probably not a big deal but it's definitely cleaner. It also means
> > the last patch in this series to mark pidfs as non-exportable can be
> > dropped. Instead pidfs export operations will be marked as
> > non-exportable in the patch that they are added in.
> 
> Can you please invert the polarity?  Marking something as not supporting
> is always awkward.  Clearly marking it as supporting something (and
> writing down in detail what is required for that) is much better, even
> it might cause a little more churn initially.

Fine by me but let's do that as a cleanup on top, please. Especially
because we need to backport this to stable.