过滤MountPointManager操作问题

为了拦截修改卷字符（Volume letter）的操作（计算机管理-磁盘管理-修改驱动器号）。我写了个驱动，挂在"\\DosDevices\\MountPointManager"上。
获取了所有IRP_MJ_DEVICE_CONTROL后看出来修改卷符号的操作是这样一个流程：
IOCTL_MOUNTMGR_DELETE_POINTS
IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATHS
...
IOCTL_MOUNTMGR_CREATE_POINT
...

但当我修改代码阻止DELETE_POINT和CREATE_POINT 操作之后，每次修改盘符的时候就出现下面这种现象：
1.被修改的盘的盘符没了，也就无法通过explorer或者cmd访问了。
2.修改的时候出现的事件如下：
IOCTL_MOUNTMGR_DELETE_POINTS!
We should ban this operation!!（这是我完成IRP操作的时候显示的）
IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATHS!
IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATHS!
IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATHS!
IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATHS!
IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATHS!
IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATHS!
IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATHS!
IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATHS!
IOCTL_MOUNTMGR_CREATE_POINT!
We should ban this operation!!
IOCTL_MOUNTMGR_QUERY_POINTS!
IOCTL_MOUNTMGR_DELETE_POINTS!
We should ban this operation!!
IOCTL_MOUNTMGR_CREATE_POINT!
We should ban this operation!!
IOCTL_MOUNTMGR_QUERY_POINTS!
IOCTL_MOUNTMGR_DELETE_POINTS!
We should ban this operation!!
IOCTL_MOUNTMGR_CREATE_POINT!
We should ban this operation!!
IOCTL_MOUNTMGR_QUERY_POINTS!
IOCTL_MOUNTMGR_DELETE_POINTS!
We should ban this operation!!
IOCTL_MOUNTMGR_CREATE_POINT!
We should ban this operation!!
IOCTL_MOUNTMGR_QUERY_POINTS!
IOCTL_MOUNTMGR_DELETE_POINTS!
We should ban this operation!!
IOCTL_MOUNTMGR_CREATE_POINT!
We should ban this operation!!
IOCTL_MOUNTMGR_QUERY_POINTS!
IOCTL_MOUNTMGR_DELETE_POINTS!
We should ban this operation!!
IOCTL_MOUNTMGR_QUERY_POINTS!
...（一堆IOCTL_MOUNTMGR_QUERY_POINTS）

用于返回IRP的代码：
KdPrint(("We should ban this operation!!\n"));
Irp->IoStatus.Status=STATUS_INVALID_PARAMETER;
Irp->IoStatus.Information=0;
IoCompleteRequest(Irp,IO_NO_INCREMENT);
return STATUS_UNSUCCESSFUL;

请问为何会出现这种情况？多谢！

没人看么？顶下顶下！