Re: [PATCH 2/2] nfsd: Change the default to enable all minor versions unless told otherwise

["bfields@fieldses.org" <bfields@fieldses.org>]

On Fri, Feb 24, 2017 at 01:27:57PM +1100, NeilBrown wrote:
> On Fri, Feb 24 2017, Trond Myklebust wrote:
> 
> > Hi Neil,
> >
> > On Fri, 2017-02-24 at 12:17 +1100, NeilBrown wrote:
> >> On Thu, Feb 23 2017, Trond Myklebust wrote:
> >> 
> >> > Instead of letting the kernel decide, default to enabling all
> >> > versions,
> >> > and let the user be more specifc in /etc/nfs.conf or on the command
> >> > line.
> >> 
> >> What is your rationale for this?
> >> I think there is value in allowing the kernel to support a version
> >> while
> >> disabling it by default.  This allows it to be used for
> >> experimentation,
> >> without much risk of it being used in production until it is deemed
> >> to
> >> be really ready.
> >
> > I think we can still do that by having the kernel simply not report
> > that version. You'll note that -V4.x and -N4.x are allowed whether or
> > not the kernel is reporting a version 'x' in /proc/fs/nfsd/versions.
> >
> > IOW: if you want to make the version not appear by default because it
> > is unstable, then you probably don't want it to appear when the user
> > does '+V4' either so you might as well hide it in
> > /proc/fs/nfsd/versions too.
> 
> That seems reasonable - possibly even better than the current approach,
> though it is hard to be sure without actually trying it out for a while.
> I haven't poured over the patches enough for a reviewed-by, but
>   Acked-by: NeilBrown <neilb@suse.com>

It's too late to tell old kernels to hide experimental versions, though.
And it's 4.1's experimental stage that's most likely to be a
problem--though maybe that's getting long enough go that not too many
people are bisecting back to that era of kernel.

I dunno, I'm inclined to drop as long as this part isn't necessary to
solve Trond's immediate problem.

--b.