nfsd: Add macro NFS_ACL_MASK for ACL

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/include/uapi/linux/nfsacl.h b/include/uapi/linux/nfsacl.h
index 9bb9771..5527266 100644
--- a/include/uapi/linux/nfsacl.h
+++ b/include/uapi/linux/nfsacl.h
@@ -22,6 +22,7 @@
 #define NFS_ACLCNT		0x0002
 #define NFS_DFACL		0x0004
 #define NFS_DFACLCNT		0x0008
+#define NFS_ACL_MASK		0x000f
 
 /* Flag for Default ACL entries */
 #define NFS_ACL_DEFAULT		0x1000