IoCreateFileEx and FltCreateFileEx similarities

Mauro_Leggieri

Hi, calling FltCreateFileEx with a given FLT_INSTANCE is the same than using FltGetVolumeFromInstance then FltGetDeviceObject and using that DEVICE_OBJECT in a call to IoCreateFileEx or IoCreateFileSpecifyDeviceObjectHint?

I want to merge/refactor some common code and was asking myself if the above applies.

Thanks,
Mauro.

rod_widdowson

The filter manager routines respect the filter manager hierarchy, the io ones only respect the device object hierarchy (a super set), so by not calling filter manger you will risk skipping a mini filter.

Mauro_Leggieri

Excellent.

Thanks @rod_widdowson for pointing it out. Now I remember filter manager groups some filters.

Kind regards.