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

[Christoph Hellwig]

On Tue, Jan 20, 2026 at 07:50:32AM -0500, Jeff Layton wrote:
> At this point, maybe we should just go with Neil's 
> EXPORT_OP_SUPPORTS_NFS_EXPORT or something. It's much more arbitrary,
> than trying to base this on criteria about filehandle stability, but it
> would give us the effect we want.

We'll still need a stable handles flag, and expose it to userspace
to avoid applications being tricked into using broken non-stable
file handles.  We should have caught that when they were added, but
didn't unfortunately.