It is currently impossible to apply an ACL to existing files that matches the result of new files created in a directory with a default ACL.

For example, the closest I can get is:

    $ umask 0000
    $ mkdir /tmp/test
    $ touch /tmp/test/a
    $ setfacl -R -d -m u:nobody:rwx /tmp/test
    $ setfacl -R -m u:nobody:rwX /tmp/test
    $ touch /tmp/test/b
    $ getfacl /tmp/test/{.,*}
    getfacl: Removing leading '/' from absolute path names
    # file: tmp/test/.
    # owner: phemmer
    # group: adm
    user::rwx
    user:nobody:rwx
    group::rwx
    mask::rwx
    other::rwx
    default:user::rwx
    default:user:nobody:rwx
    default:group::rwx
    default:mask::rwx
    default:other::rwx
   
    # file: tmp/test/a
    # owner: phemmer
    # group: adm
    user::rw-
    user:nobody:rw-
    group::rw-
    mask::rw-
    other::rw-
   
    # file: tmp/test/b
    # owner: phemmer
    # group: adm
    user::rw-
    user:nobody:rwx #effective:rw-
    group::rwx #effective:rw-
    mask::rw-
    other::rw-

While the effective permissions are the same, the actual permissions are not. The only reliable way I can think of to apply the default ACL to existing files would be to create a file in each directory, and use the resulting ACL from that file to apply on the existing files.

This behavior is observed with setfacl-2.2.51 & kernel-3.13.6