Re: [PATCH] Adding the nfs4_use_min_auth module parameter

["J. Bruce Fields" <bfields@fieldses.org>]

On Fri, Nov 08, 2013 at 11:19:45AM -0500, Steve Dickson wrote:
> 
> 
> On 08/11/13 11:17, J. Bruce Fields wrote:
> > On Fri, Nov 08, 2013 at 11:10:14AM -0500, Steve Dickson wrote:
> >>
> >>
> >> On 08/11/13 10:12, Jeff Layton wrote:
> >>> On Fri, 08 Nov 2013 10:00:02 -0500
> >>> Steve Dickson <SteveD@redhat.com> wrote:
> >>>
> >>>>
> >>>>
> >>>> On 08/11/13 08:22, Jeff Layton wrote:
> >>>>> On Fri, 08 Nov 2013 07:41:32 -0500
> >>>>> Steve Dickson <SteveD@redhat.com> wrote:
> >>>>>
> >>>>>>
> >>>>>>
> >>>>>> On 07/11/13 18:05, Chuck Lever wrote:
> >>>>>>>
> >>>>>>> On Nov 7, 2013, at 1:35 PM, Steve Dickson <SteveD@redhat.com> wrote:
> >>>>>>>
> >>>>>>>> Hey mrchuck... 
> >>>>>>>>
> >>>>>>>> On 07/11/13 14:25, Chuck Lever wrote:
> >>>>>>>>> Hi Steve-
> >>>>>>>>>
> >>>>>>>>> On Nov 7, 2013, at 11:09 AM, Steve Dickson <steved@redhat.com> wrote:
> >>>>>>>>>
> >>>>>>>>>> This new module parameter makes the v4 client
> >>>>>>>>>> use the minimal authentication flavor (AUTH_UNIX)
> >>>>>>>>>> when establishing NFSV4 state and doing the
> >>>>>>>>>> pseudoroot lookup
> >>>>>>>>>
> >>>>>>>>> The patch description doesn't say, but is this change to work 
> >>>>>>>>> around the 15 second GSSD upcall timeout? 
> >>>>>>>> Yes. A 15 second delay on every mount due to security that
> >>>>>>>> nobody is requesting is just not good.. IMHO..
> >>>>>>>
> >>>>>>> One thing we haven't discussed is reducing the upcall timeout to 5 seconds or less, 
> >>>>>>> as a form of immediate relief.  15 seconds is arbitrary, and is onerous even when 
> >>>>>>> you expect the mount to work (ie why would it be good for any properly configured 
> >>>>>>> environment to take 15 seconds to establish a GSS context?).
> >>>>>>>
> >>>>>>> In other words, there are still cases where users wait 15 seconds unnecessarily, 
> >>>>>>> and not because of the use of krb5i for lease management.  Aren't those of concern?
> >>>>>> No. I think the concern here, at least my concern, is the lack of management.
> >>>>>> We are forcing admins to use krb5i in lease management when its not necessary
> >>>>>> and there is no way to turn it off.
> >>>>>>   
> >>>>>
> >>>>> I don't think that's really the case. The idea was to have the client
> >>>>> attempt to use krb5i if it's available, and then to fall back to
> >>>>> AUTH_SYS if it isn't. This would be *absolutely* no big deal if the
> >>>>> GSSAPI upcall succeeded or failed immediately instead of requiring this
> >>>>> timeout when the daemon isn't running.
> >>>> What server makes krb5i available today in state setup and pseudoroot lookups?
> >>>>
> >>>
> >>> That I don't know...sorry...
> >> Then what is the justification to take all these extra steps
> >> there they going to fail %100 of the time??
> > 
> > Any server can support krb5 for state setup and pseudoroot operations if
> > it's configured.  This isn't a problem.
> Would is this done on a Linux server? Is there a wiki?

It's allowed by default, there should be nothing to configure beyond the
usual krb5 setup.

--b.