nfs-kernel-server mountd check only checks for nfsv3 via UDP, not TCP

See also https://bugs.launchpad.net/ubuntu/+source/nfs-utils/+bug/897644

Actually, I am thinking that the right fix is to remove the check and the "--no-nfs-version 3" item completely, because:

  - There is no similar check for nfs versions 2 or 4, so it's weirdly inconsistent
  - As bug 897644 shows, it won't be possible to fix it completely anyway
  - We don't know why we need to pass that option to rpc.mountd in the first place!

If this was to prevent a crasher caused by a client bug, I don't believe a modern linux client will crash if it attempts to mount an nfsv3 mount if rpc.nfsd isn't serving version 3.

And if the user wants to disable a specific version, he's more likely to think he should do all that configuration in /etc/default/nfs-kernel-version anyway.

One gotcha in that file is that multiple options need to be quoted; maybe a nice fix would be to quote the defaults in there, i.e.

     RPCMOUNTDOPTS="--manage-gids"
     RPCSVCGSSDOPTS=""
     RPCNFSDOPTS=""

So it's easier to tack something on. Other default files seem to do that.

This bug was fixed in the package nfs-utils - 1:1.2.8-6ubuntu1

---------------
nfs-utils (1:1.2.8-6ubuntu1) trusty; urgency=medium

  * Merge from Debian unstable, remaining changes:
    - debian/nfs-common.{statd,statd-mounting,gssd,idmapd}.upstart,
      debian/control, debian/nfs-common.{preinst,postinst,prerm,postrm},
      debian/rules: drop nfs-common init script in favor of upstart jobs.
    - Depend on rpcbind (>= 0.2.0-6ubuntu1) for upstart support.
    - Depend on mountall (>= 2.41) to avoid deadlocks on boot.
    - debian/nfs-common.default: always start idmapd automatically; drop
      the configuration option.
    - nfs-kernel-server.init: Unmount nfsd fs when init script stops
    - Allow issuing options to rpc.nfsd
    - Add "-e" (ticket expiry is error) option to rpc.gssd to prevent hangs
      due to EKEYEXPIRED error from kernel on ticket expiry.

nfs-utils (1:1.2.8-6) unstable; urgency=medium

  * Fix the sec=krb5* handling in debian/nfs-common.init to properly match
    all cases. Closes: #715478.
  * Move the rpc.svcgssd(8) symlink to nfs-common along with the rest of it,
    and add the Replaces: on old versions of nfs-kernel-server to support
    upgrades properly. Closes: #731479.
  * Only start nfs-common in runlevel S; it doesn't need to be started
    more than once (and startpar won't actually run it more than once,
    anyway). Closes: #510528.
  * Fix obsolete invocations of update-rc.d by switching nfs-common to use
    dh_installinit. Closes: #736059.
  * Tweak nfs-common preinst to not remove nfs state files except on package
    removal (i.e., these should not be removed when the package is
    deconfigured temporarily).
  * debian/nfs-kernel-server.init: don't try to check for nfsv3 configuration
    in nfsd and pass --no-nfs-version 3 to mountd if absent; the check is
    buggy and impossible to make reliable, and there's no reason to single
    out NFSv3 here (and the original rationale for this behavior is lost).
    Closes LP: #897644, LP: #1284210.
  * Provide quoted entries by default in debian/nfs-kernel-server.default,
    consistent with other default files, so that users who edit the file to
    add multiple options don't accidentally cause shell syntax bugs.
 -- Steve Langasek <email address hidden> Tue, 25 Feb 2014 09:18:47 -0800