DeviceIoControl的奇怪问题

  我写了个filter,在filter里自建了一个METHOD_BUFFERED ioctl code,然后在程序中用DeviceIoControl读取数据,结果却读不到数据,但返回值是正确的.代码大致是这样的:

DeviceIoControl(h, IOCTL_CODE, inputbuffer, inputbuffersize, 0, 0, &byteOutput, NULL);


驱动里是这样的:

PMYSTRUCT pvii;
pvii = (PMYSTRUCT)Irp->AssociatedIrp.SystemBuffer;
RtlCopyMemory(pvii, src, sizeof(MYSTRUCT));

Irp->IoStatus.Status = STATUS_SUCCESS;
Irp->IoStatus.Information = sizeof(MYSTRUCT);
IoCompleteRequest(Irp, IO_NO_INCREMENT);
return STATUS_SUCCESS;

已解决.

我的输入缓冲和输出缓冲都是pvii;但调用DeviceIoControl时未指定输出缓冲为pvii.