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

Christoph Hellwig
2026-01-19T07:26:03Z

On Mon, Jan 19, 2026 at 06:22:42PM +1100, NeilBrown wrote:
> We are calling it for it's only use. If there was ever another use, we
> could change the name if that made sense. It is not a public name, it
> is easy to change.

No, it is not the only use. This flag needs to be propagate to
userspace through statx or the file attrs. As I said before there
is plenty of code in userspace that does rely on the traditional
file handle semantics.

> > Remember nfs also support volatile file handles, and other applications
> > might rely on this (I know of quite a few user space applications that
> > do, but they are kinda hardwired to xfs anyway).
>
> The NFS protocol supports volatile file handles. knfsd does not.
> So maybe
> EXPORT_OP_NOT_NFSD_COMPATIBLE
> might be better. or EXPORT_OP_NOT_LINUX_NFSD_COMPATIBLE.
> (I prefer opt-out rather than opt-in because nfsd export was the
> original purpose of export_operations, but it isn't something
> I would fight for)

Again, stop trying to name things of the initial user. Flag needs to
describe smenatics, not users.