set io stack location

NTFSD
1

Hi,
In the IRP_MAJOR_READ dispatch routine, I did something like this at first:

NTSTATUS status = STATUS_SUCCESS;
PIO_STACK_LOCATION IrpStack = IoGetCurrentIrpStackLocation(Irp);
//do something using IrpStack

but, I want to call the next driver now, How should I set the IO stack location?

and, how should I use the function DbgPrint?