We, GFS-WG, would like to introduce access control mechanism in hierarchical naming space just like directory-based 
access control in ordinal file system.  The access control can be on a user basis and on a group basis for each file and
 directory.  It is not possible to access even namespace itself if it is under a directory that is not allowed to be 
accessed.  Moreover, the access control list can be modified by the owner, or permitted users.  How can this mechanism 
be introduced in WS-Directory?.