PMRX_EXTENDFILE_CALLDOWN callback function (mrx.h)
The MRxExtendForCache routine is called by RDBSS to request that a network mini-redirector extend a file when the file is being cached by the cache manager.
Syntax
PMRX_EXTENDFILE_CALLDOWN PmrxExtendfileCalldown;
ULONG PmrxExtendfileCalldown(
IN OUT PRX_CONTEXT RxContext,
IN OUT PLARGE_INTEGER NewFileSize,
OUT PLARGE_INTEGER NewAllocationSize
)
{...}
Parameters
RxContext
[in, out] A pointer to the RX_CONTEXT structure. This parameter contains the IRP that is requesting the operation.
NewFileSize
[in, out] A pointer to the LARGE_INTEGER structure indicating the byte count of the new file size.
NewAllocationSize
[out] A pointer to the LARGE_INTEGER structure for storing the new allocation size when MRxExtendForCache returns.
Return value
MRxExtendForCache returns STATUS_SUCCESS on success or an error code on failure.
Remarks
MRxExtendForCache handles network requests to extend the file for cached I/O.
Before calling MRxExtendForCache, 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
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | mrx.h (include Mrx.h) |