I did samba re-export of the gluster mount-point. I created a file on gluster mount-point and set the acl permission for others to "---". When I tried to access the file from the windows, I got an error which said "can not open the \\<ip-addr>\testacl\testfile.txt file. make sure a disk is in the drive you specified". When I repeated the above exercise with ext3 backend (no gluster mount point), I got the error as "Access Denied" which is expected.
set the backend permission for others as ---. Open both on backend samba and gluster mount samba failed with Access denied