mounted_lock
error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
error = mounted_lock(sdp, DLM_LOCK_NL, 0);
error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);