/* user context: submit dag for execution, return non-zero if we have * to wait for completion. if and only if we return non-zero, we'll * cause cbFunc to get invoked with cbArg when the DAG has completed. * * for now we always return 1. If the DAG does not cause any I/O, * then the callback may get invoked before DispatchDAG returns. * There's code in state 5 of ContinueRaidAccess to handle this. * * All we do here is fire the direct successors of the header node. * The DAG execution thread does the rest of the dag processing. */