自己分配的irp失败后应该在cancel例程中释放吗还是该立即释放??

PIRP irp = IoBuildDeviceIoControlRequest( //0X1B0048
        0x1B0040, m_TargetDevice, &lEvent, sizeof(ULONG),
        &lEvent, sizeof(ULONG), false, m_Event, &IoStatus);
IoSetCanelRoute(CancelRoute) ;   ////-----!!!!!这里
status = IoCallDriver(m_TargetDevice->DeviceObject(),irp);
if (status==STATUS_PENDING){
     status = KeWaitForSingleObject(m_Event,Executive ,  KernelMode ,   false , &timeout);
   if (status==STATUS_TIMEOUT){
IoCancelIrp(irp);  
           IoFreeIrp(irp); //////?????是该这里释放Irp  
                         //////还是应该在CancelRoute释放Irp
   }
}
///////////

PIRP irp = IoBuildDeviceIoControlRequest( //0X1B0048
        0x1B0040, m_TargetDevice, &lEvent, sizeof(ULONG),
        &lEvent, sizeof(ULONG), false, m_Event, &IoStatus);
IoSetCanelRoute(CancelRoute) ;   ////-----!!!!!这里
status = IoCallDriver(m_TargetDevice->DeviceObject(),irp);
if (status==STATUS_PENDING){
     status = KeWaitForSingleObject(m_Event,Executive ,  KernelMode ,   false , &timeout);
   if (status==STATUS_TIMEOUT){
IoCancelIrp(irp);  
           IoFreeIrp(irp); //////?????是该这里释放Irp  
                         //////还是应该在CancelRoute释放Irp
   }
}
///////////  

应该设置完成例程，在完成例程里释放，并且返回STATUS_MORE_PROCESSING_REQUIRED 以避免io管理器处理

谢谢楼上哈，我也刚看懂为什么IoCanelIrp中也要IoCompletele ..

为何要返回STATUS_MORE_PROCESSING_REQUIRED？