The FsRtlLookupLastLargeMcbEntry routine retrieves the last mapping entry stored in the map control block (MCB).
BOOLEAN FsRtlLookupLastLargeMcbEntry( _In_ PLARGE_MCB OpaqueMcb, _Out_ PLONGLONG LargeVbn, _Out_ PLONGLONG LargeLbn );
- OpaqueMcb [in]
Pointer to an initialized MCB structure to be searched.
- LargeVbn [out]
Pointer to a variable that receives the last virtual block number (VBN) that was mapped.
- LargeLbn [out]
Pointer to a variable that receives the logical block number (LBN) that is mapped to the VBN pointed to by LargeVbn, or -1 if no such LBN exists.
FsRtlLookupLastLargeMcbEntry returns FALSE if the MCB contains no mapping entries, TRUE otherwise.
FsRtlLookupLastLargeMcbEntry searches for the last mapping of the last run in the MCB:
If the MCB contains no mappings, FsRtlLookupLastLargeMcbEntry returns FALSE.
If the last mapping is a hole, FsRtlLookupLastLargeMcbEntry returns TRUE, but the lookup operation yields a value of -1 for the LBN.
If the last mapping is not a hole, the lookup operation yields a positive value for the LBN, and FsRtlLookupLastLargeMcbEntry returns TRUE.
Note The upper 32 bits of the LBN are ignored. Only the lower 32 bits are used.