第二个参数,看仔细
Instance
An opaque instance pointer for the minifilter driver instance that the create request is to be sent to. The instance must be attached to the volume where the file or directory resides. This parameter is optional and can be NULL. If this parameter is NULL, the request is sent to the device object at the top of the file system driver stack for the volume. If it is non-NULL, the request is sent only to minifilter driver instances that are attached below the specified instance.