NFSv4 client crash in Knoppix 7.0.4 (and work-araound)

[renderer]

Hi guys!

I just downloaded Knoppix 7.0.4 DVD, and find that mounting NFS filing systems fails with a kernel bug.

Running a simple "mount" command for NFS results in:

[ 4722.137838] NFS: Registering the id_resolver key type
[ 4722.137929] FS-Cache: Netfs 'nfs' registered for caching
[ 4722.143743] ------------[ cut here ]------------
[ 4722.146992] Kernel BUG at f943a8df [verbose debug info unavailable]
[ 4722.146992] invalid opcode: 0000 [#1] PREEMPT SMP
[ 4722.146992] Modules linked in: nfs i8k parport_pc ppdev lp parport ipv6 dell_wmi sparse_keymap 8250_pnp dell_laptop 8250 serial_core coretemp wmi dcdbas battery ac snd_hda_codec_idt pcmcia arc4 iwl3945 iwlegacy mac80211 cfg80211 yenta_socket tg3 i2c_i801 snd_hda_intel joydev snd_hda_codec i915 drm_kms_helper
[ 4722.146992]
[ 4722.146992] Pid: 4441, comm: mount.nfs Tainted: G W 3.4.9 #34 Dell Inc. Latitude D830 /0HN341
...
This appears to be a bug in the kernel triggered when trying to use NFS version 4, as discussed here:
https://bugzilla.redhat.com/show_bug.cgi?id=838730

The work-around is to specify NFS version 3 in the mount command (or fstab), as described here:
http://us.generation-nt.com/answer/disabling-nfsv4-debian-squeeze-help-205488241.html

for example:
# mount -o nfsvers=3 server:/data /data

I hope this helps somebody. It gave me a few hours of frustration.
--
renderer