O uso de -Rd
só faz sentido ao lidar com diretórios. Para modificar as ACLs de um determinado arquivo e adicionar outro usuário, basta fazer isso:
$ sudo setfacl -m u:user1:rwx somefile
$ getfacl somefile
# file: somefile
# owner: root
# group: root
user::rw-
user:user1:rwx
group::r--
mask::rwx
other::r--
Por man setfacl
page :
-R, --recursive
Apply operations to all files and directories recursively. This
option cannot be mixed with '--restore'.
-d, --default
All operations apply to the Default ACL. Regular ACL entries in the
input set are promoted to Default ACL entries. Default ACL entries in
the input set are discarded. (A warning is issued if that
happens).