FsRtlTruncateLargeMcb function (ntifs.h)

Article
02/22/2024

The FsRtlTruncateLargeMcb routine truncates a large map control block (MCB).

Syntax

void FsRtlTruncateLargeMcb(
  PLARGE_MCB Mcb,
  LONGLONG   Vbn
);

Parameters

Mcb

Pointer to the MCB structure.

Vbn

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

Return value

None

Remarks

FsRtlTruncateLargeMcb truncates an MCB structure by removing all mappings for VBNs in the range starting with *LargeVbn and ending with the highest mapped VBN. If the starting VBN belongs to a hole (a range of unmapped VBNs that form a gap between two mappings), the hole is also removed. The MCB's PairCount member is adjusted accordingly.

If the starting VBN is zero, all mappings are removed from the MCB.

Requirements

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