Use all the pieces set up so far to implement referral support, allowing
return of NFS4ERR_MOVED and fs_locations attribute.

Signed-off-by: Manoj Naik <manoj@almaden.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>