FsRtlRemoveLargeMcbEntry function (ntifs.h)

Article
02/22/2024

The FsRtlRemoveLargeMcbEntry routine removes one or more mappings from a map control block (MCB).

Syntax

void FsRtlRemoveLargeMcbEntry(
  PLARGE_MCB Mcb,
  LONGLONG   Vbn,
  LONGLONG   SectorCount
);

Parameters

Mcb

Pointer to the MCB structure.

Vbn

Starting virtual block number (VBN) of the range for which mappings are to be removed from the MCB.

SectorCount

Number of sectors (VBNs) in the range for which mappings are to be removed.

Return value

None

Remarks

FsRtlRemoveLargeMcbEntry removes all mappings of VBNs to LBNs in the MCB that fall within the range of VBNs that begins with *LargeVbn and ends with (*LargeVbn + LargeSectorCount - 1).

Note The upper 32 bits of the LBN are ignored. Only the lower 32 bits are used.

Holes (gaps) between mappings are ignored.

If the range of VBNs to be removed includes the highest mapped VBN in the MCB, the MCB's PairCount member is adjusted accordingly.

If a pool allocation failure occurs, FsRtlRemoveLargeMcbEntry raises a STATUS_INSUFFICIENT_RESOURCES exception. To gain control if this pool allocation failure occurs, the driver should wrap the call to FsRtlRemoveLargeMcbEntry in a try-except or try-finally statement.

Requirements

Requirement	Value
Target Platform	Universal
Header	ntifs.h (include Ntifs.h)
Library	NtosKrnl.lib
DLL	NtosKrnl.exe
IRQL	<= APC_LEVEL