Re: [GIT PULL] NFSD changes for v6.18

Linus Torvalds
2025-10-06T21:54:56Z

On Mon, 6 Oct 2025 at 14:20, Johannes Berg <johannes@sipsolutions.net> wrote:
>
> That doesn't mean it's between the host and guest kernels, it's just
> between code built for "userspace" and code built for "kernel", both of
> which go into the UML linux "guest" binary. IOW, it's just for
> communication between hostfs_kern.c and hostfs_user.c, which nobody else
> needs to care about.

I was worried about people having version mismatches between those two parts.

But if that can't happen then that certainly simplifies things.

> However ... it looks like hostfs_kern.c is using ATTR_* in some places,
> and hostfs_user.c is using HOSTFS_ATTR_*, so it looks like right now
> these *do* need to match. Given that, we should just generate them via
> asm-offsets.h, like we do for other constants with the property of being
> needed on both sides but defined in places that cannot be included into
> user-side code, like this:

Sounds good.

> (that passes my usual tests, if you want you can apply it as is, or I
> can resend it as a real patch, or I can also put it into uml-next for
> later...)

None of this is the least critical - the bits I actually reacted to
aren't even used by hostfs so we also don't need to synchronize these
(potential) updates with each other.

So it does look like a good idea to remove the hardcoded "these bits
must match" thing, but clearly this hasn't been causing huge problems
in the many years they've been that way.

IOW - I'll wait for a later pull request from you.

Linus