MRxExtendForNonCache routine

Article
03/14/2023

The MRxExtendForNonCache routine is called by RDBSS to request that a network mini-redirector extend a file when the file is not being cached by the cache manager.

Syntax

PMRX_EXTENDFILE_CALLDOWN MRxExtendForNonCache;

ULONG MRxExtendForNonCache(
  _Inout_ PRX_CONTEXT    RxContext,
  _Inout_ PLARGE_INTEGER pNewFileSize,
  _Out_   PLARGE_INTEGER pNewAllocationSize
)
{ ... }

Parameters

RxContext [in, out]
A pointer to the RX_CONTEXT structure. This parameter contains the IRP that is requesting the operation.

pNewFileSize [in, out]
A pointer to the LARGE_INTEGER value indicating the byte count of the new file size.

pNewAllocationSize [out]
A pointer to the LARGE_INTEGER for storing the new allocation size when MRxExtendForCache returns.

Return value

MRxExtendForNonCache returns STATUS_SUCCESS on success or an error code on failure.

Remarks

MRxExtendForNonCache handles network requests to extend the file for non-cached I/O.

Before calling MRxExtendForNonCache, RDBSS modifies the following members in the RX_CONTEXT structure pointed to by the RxContext parameter:

LowIoContext.Operation is set to LOWIO_OP_WRITE

LowIoContext.ParamsFor.ReadWrite.Flags has the LOWIO_READWRITEFLAG_EXTENDING_FILESIZE bit set

A network mini-redirector that caches file or directory information may need to invalidate its cache information when the file is extended.

Requirements

Target platform	Desktop
Header	Mrx.h (include Mrx.h)