Re: [PATCH v2 0/4] nfs/nfsd/sunrpc: enforce NFSv4 transport requirements

[Jeff Layton <jlayton@redhat.com>]

On Mon, 2017-02-27 at 07:08 -0500, Tom Talpey wrote:
> On 2/27/2017 6:59 AM, Jeff Layton wrote:
> > What we'd need to make that happen, I think is a [global] stanza in
> > nfs.conf with a single 'nfsd_v3' boolean that defaults to off. If
> 
> Don't forget v2! And maybe even v4.0 if you're encouraging non-legacy
> operation. RFC3530 was published 14 years ago, btw. RFC1813 in 1995,
> and RFC1094 in 1989.

I think v2 already defaults to off these days? But yeah, I could see us
adding a similar boolean for v2. Maybe we don't need a new switch at
all, and just need to have everything look at the [nfsd] vers2= and
vers3= config file options?

I think wiring nfsd and mountd up properly for this would be fairly easy
here. statd is a little tougher since we don't want to run it or sm-
notify at all if v2/3 are disabled. I wonder if there is any way we can
make systemd look at this config file and decide whether to start statd
based on whether either of those options is set?

I'd have no issue with eventually defaulting with v4.0 disabled as well,
but there are a fair number of clients in the field that don't support
v4.1 (or don't support it well). I think we'd need to wait and see how
much grief we get about disabling v3 by default before we go there. 

-- 
Jeff Layton <jlayton@redhat.com>