path_openat
filp = path_openat(&nd, op, flags | LOOKUP_RCU);
filp = path_openat(&nd, op, flags);
filp = path_openat(&nd, op, flags | LOOKUP_REVAL);
file = path_openat(&nd, op, flags | LOOKUP_RCU);
file = path_openat(&nd, op, flags);
file = path_openat(&nd, op, flags | LOOKUP_REVAL);