Mounting a DFS share fails with Error 22 (invalid argument)

Issue

• Unable to mount a DFS share.
• Unable to mount a CIFS DFS share. See a sample:

[root@server01 ~]# mount //dfsserver.example.com/example/share /mnt/example -o username=testuser,workgroup=EXAMPLE,uid=testuser,rw,gid=testuser,dir_mode=0775
mount error(22): Invalid argument
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)