Storage Filter Driver's Device-Type-Specific Functionality
Depending on the nature of its device, an storage filter driver (SFD) might be responsible for the following device-type-specific functionality:
Translating data from or into a device-specific format before or after sending a transfer request to lower drivers if the device processes data in a nonstandard format
Setting up IRPs with SRBs for port-driver-supported I/O control requests, for driver-defined I/O control requests, or for pass-through requests, as necessary for its device, and sending those IRPs to the next-lower driver
Modifying class driver-supplied SRBs as necessary for its device
Establishing time-out values for requests
Supplying one or more IoCompletion routines and, like the corresponding storage class driver, handling certain error conditions and retries for device-specific requests that require special handling
In general, an SFD has the same responsibilities as a storage class driver for those requests that require device-specific handling. For a discussion of the functionality required of storage class drivers, see Storage Class Drivers.