typedef struct _FS_FILTER_CALLBACKS
{
     ULONG SizeOfFsFilterCallbacks;
     ULONG Reserved;
     LONG * PreAcquireForSectionSynchronization;
     PVOID PostAcquireForSectionSynchronization;
     LONG * PreReleaseForSectionSynchronization;
     PVOID PostReleaseForSectionSynchronization;
     LONG * PreAcquireForCcFlush;
     PVOID PostAcquireForCcFlush;
     LONG * PreReleaseForCcFlush;
     PVOID PostReleaseForCcFlush;
     LONG * PreAcquireForModifiedPageWriter;
     PVOID PostAcquireForModifiedPageWriter;
     LONG * PreReleaseForModifiedPageWriter;
     PVOID PostReleaseForModifiedPageWriter;
} FS_FILTER_CALLBACKS, *PFS_FILTER_CALLBACKS;

Windows Vista Kernel Structures