FltStartFiltering function (fltkernel.h)

FltStartFiltering starts filtering for a registered minifilter driver.


NTSTATUS FLTAPI FltStartFiltering(
  [in] PFLT_FILTER Filter


[in] Filter

Opaque filter pointer returned by FltRegisterFilter.

Return value

FltStartFiltering returns STATUS_SUCCESS or an appropriate NTSTATUS value such as the following:

Return code Description
Filtering was already started for this minifilter driver. This is an error code.


A minifilter driver typically calls FltStartFiltering from its DriverEntry routine after it has completed its global initialization and called FltRegisterFilter. FltStartFiltering notifies the Filter Manager that the minifilter driver is ready to begin attaching to volumes and filtering I/O requests. After the minifilter driver calls this routine, the Filter Manager treats the minifilter driver as a fully active minifilter driver, presenting it with volumes to attach to, as well as I/O requests. The minifilter driver must be prepared to begin receiving these notifications and I/O requests even before FltStartFiltering returns.


Target Platform Universal
Header fltkernel.h (include Fltkernel.h)
Library FltMgr.lib
DLL Fltmgr.sys

See also