Re: NFSv4 referrals broken when not enabling junction support

[Salvatore Bonaccorso <carnil@debian.org>]

Hi Steve,

On Sat, Oct 26, 2024 at 09:04:01AM -0400, Steve Dickson wrote:
> 
> 
> On 10/25/24 4:14 PM, Salvatore Bonaccorso wrote:
> > Hi Steve,
> > 
> > On Sun, Oct 20, 2024 at 04:37:10PM +0200, Salvatore Bonaccorso wrote:
> > > Hi Steve,
> > > 
> > > On Tue, Oct 08, 2024 at 06:12:58AM -0400, Steve Dickson wrote:
> > > > 
> > > > 
> > > > On 10/3/24 12:58 PM, Salvatore Bonaccorso wrote:
> > > > > Hi Steve, hi linux-nfs people,
> > > > > 
> > > > > it got reported twice in Debian that  NFSv4 referrals are broken when
> > > > > junction support is disabled. The two reports are at:
> > > > > 
> > > > > https://bugs.debian.org/1035908
> > > > > https://bugs.debian.org/1083098
> > > > > 
> > > > > While arguably having junction support seems to be the preferred
> > > > > option, the bug (or maybe unintended behaviour) arises when junction
> > > > > support is not enabled (this for instance is the case in the Debian
> > > > > stable/bookworm version, as we cannot simply do such changes in a
> > > > > stable release; note later relases will have it enabled).
> > > > > 
> > > > > The "breakage" seems to be introduced with 15dc0bead10d ("exportd:
> > > > > Moved cache upcalls routines  into libexport.a"), so
> > > > > nfs-utils-2-5-3-rc6 as this will mask behind the #ifdef
> > > > > HAVE_JUNCTION_SUPPORT's code which seems needed to support the refer=
> > > > > in /etc/exports.
> > > > > 
> > > > > I had a quick conversation with Cuck offliste about this, and I can
> > > > > hopefully state with his word, that yes, while nfsref is the direction
> > > > > we want to go, we do not want to actually disable refer= in
> > > > > /etc/exports.
> > > > +1
> > > > 
> > > > > 
> > > > > Steve, what do you think? I'm not sure on the best patch for this,
> > > > > maybe reverting the parts masking behind #ifdef HAVE_JUNCTION_SUPPORT
> > > > > which are touched in 15dc0bead10d would be enough?
> > > > Yeah there is a lot of change with 15dc0bead10d
> > > > 
> > > > Let me look into this... At the up coming Bake-a-ton [1]
> > > 
> > > Thanks a lot for that, looking forward then to a fix which we might
> > > backport in Debian to the older version as well.
> > 
> > Hope the Bake-a-ton was productive :)
> > 
> > Did you had a chance to look at this issue beeing there?
> Yes I did... and we did talk about the problem.... still looking into it.

Many thanks for the update!

Regards,
Salvatore