MiniFilter中如何取得IoCallDriver()状态，并继续处理?

在MiniFilter开发中，常会根据IoCallDriver的返回状态确定是否进行下一步处理.

那个状态如何获呢?

 

FltRequestOperationStatusCallback()

这个函数可以解决我们的问题.

它只能在PreOperation中调用，设置一个回调函数,

当IoCallDriver调用完成后会调用它所设置的回调函数.

 

1. Properly synchronized with unload

2.Handles operation being completed by a

  lower minifilter/Legacy filter

3.As in the legacy mode, may be called after the

operation has completed.

 

完成

  KEVENT Event;
  NTSTATUS Status;

  KeInitializeEvent(&Event, NotificationEvent, FALSE);
  IoCopyCurrentIrpStackLocationToNext(Irp);
  IoSetCompletionRoutine(Irp, SfForwardIrpSyncronouslyCompletion, &Event, TRUE, TRUE, TRUE);
  Status = IoCallDriver(DeviceObject, Irp);
  if (STATUS_PENDING == Status)
  {
    KeWaitForSingleObject(&Event, Executive, KernelMode, FALSE, NULL);

  }

 

NTSTATUS
SfForwardIrpSyncronouslyCompletion (
  IN PDEVICE_OBJECT DeviceObject,
  IN PIRP Irp,
  IN PVOID Context
  )
{
  PKEVENT Event = Context;

  UNREFERENCED_PARAMETER(DeviceObject);

  ASSERT(IS_MY_DEVICE_OBJECT(DeviceObject));

  if (Irp->PendingReturned)
  {
    KeSetEvent(Event, IO_NO_INCREMENT, FALSE);
  }

  return STATUS_MORE_PROCESSING_REQUIRED;
}

 

差不多的功能,等待下层驱动完成之后，根据返回状态进行下一步处理.