Special files include paging files, dump files, and hibernation files. If the target device for your driver is a storage device that the system might use for these files, the driver must do the following:
Call WdfDeviceSetSpecialFileSupport to enable or disable support for each type of special file. (Each driver's support for special files is disabled by default.)
Call WdfDeviceAddDependentUsageDeviceObject, if one device is dependent on another device when supporting special files.
If your driver calls WdfDeviceSetSpecialFileSupport for a device, and if a special file is open on the device, the framework does not allow the PnP manager to remove or stop the device.