+ struct sembuf sops[4];
+
+ DSS_DEBUG_LOG(("locking\n"));
+
+ sops[0].sem_num = 0;
+ sops[0].sem_op = 0;
+ sops[0].sem_flg = SEM_UNDO | IPC_NOWAIT;
+
+ sops[1].sem_num = 0;
+ sops[1].sem_op = 1;
+ sops[1].sem_flg = SEM_UNDO | IPC_NOWAIT;
+
+ sops[2].sem_num = 1;
+ sops[2].sem_op = 0;
+ sops[2].sem_flg = SEM_UNDO | IPC_NOWAIT;
+
+ sops[3].sem_num = 1;
+ sops[3].sem_op = 1;
+ sops[3].sem_flg = SEM_UNDO | IPC_NOWAIT;
+
+ return do_semop(id, sops, 4);
+}
+
+static bool mutex_is_locked(int id)
+{
+ struct sembuf sops;