bug in nfs in 2.6.18-rc5?

[Shaya Potter <spotter@cs.columbia.edu>]

so I'm trying to use unionfs, cachefs and nfs, as cachefs is 2.6.18-rc5 
right now, thats what I'm testing, but I hit an oops.

basically unionfs's lookup does a "lookup_one_len()" on the underlying fs.

lookup_one_len() calls __lookup_hash()

__lookup_hash() is called as "__lookup_hash(&this, base, NULL)"

now that NULL is important.  that's the nameidata entry of __lookup_hash()

__lookup_hash() ends up calling the underlying fs's lookup op, i.e. 
nfs_lookup()

nfs_lookup() calls nfs_reval_fsid(nd->mnt, dir, &fhandle, &fattr);

see the bug? :)

This doesn't seem like a unionfs bug, as one should be able to call 
lookup_one_len() on an NFS fs.