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

[Christoph Hellwig]

On Mon, Dec 09, 2024 at 10:16:36AM +0100, Greg KH wrote:
> > Maybe we were wrong about the assumption that cgroupfs should be treated
> > specially and deny export cgroups over nfs??
> 
> Please don't export any of the "fake" kernel filesystems (configfs,
> cgroups, sysfs, debugfs, proc, etc) over nfs please.  That way lies
> madness and makes no sense.

Umm, yes: it sounds like a pretty useless idea.  But you can do that
today with a userland nfs server, so why explicitly forbid it for
the kernel nfs server.  In either case you absolutely have to want it,
you're not going to accidentally NFS export a file system.

I'm still trying to understand what problem we're trying to solve here.