Comment 12 for bug 251923

NFS4?? Writing stuff like ...

/smb *(rw,async,no_root_squash,no_subtree_check)

... into your /etc/exports _CLEARLY_ is NFSv2/NFSv3 syntax and _NOT_ NFSv4 syntax. And I already wrote where this bug comes from:

nfs-common
nfs-kernel-server

The "mount.nfs" binaries in those packages simply don't understand the mount options anymore that I need for "Sun Secure Global Desktop" and its "Client Drive Mapping" mechanism to function on Ubuntu

Did you even try what I wrote in my first posting over one year ago? Put this line into your /etc/exports:
/smb *(rw,async,no_root_squash,no_subtree_check)

And then try and mount it with this command:
sudo mount -t nfs -o rw,udp,mountvers=2,port=4242 localhost:/smb /smb

With Ubuntu 7.10 and earlier ==> Above command WORKS.
With Ubuntu 8.04 and later ==> Above command DOES NOT WORK.

Unless you tried the same options (rw,udp,mountvers=2,port=4242) then I'd say your problem has nothing to do with this bug or NFS4. Sorry to say so.

Results with Ubuntu 7.10:
sudo mount -t nfs -o rw,udp,mountvers=2,port=4242 localhost:/smb /smb

=> WORKS!

Results with Ubuntu 9.10:

sudo mount -t nfs -o rw,udp,mountvers=2,port=4242 localhost:/smb /smb
mount.nfs: an incorrect mount option was specified

Variations, leaving parts of the parameters away:

sudo mount -t nfs -o rw,udp,port=4242 localhost:/smb /smb
mount.nfs: mount system call failed

sudo mount -t nfs -o rw,port=4242 localhost:/smb /smb
mount.nfs: mount system call failed

This stuff WORKED in Ubuntu 7.10