CcDeferWrite function

Description

The CcDeferWrite routine defers writing to a cached file. The post routine that is supplied, is called by the cache manager when it can accommodate the write operation.

Parameters

FileObject [in]

Pointer to a file object for the cached file to which the data is to be written.

PostRoutine [in]

Address of a routine for the cache manager to call to write to the cached file. Note that it is possible that this routine will be called immediately, even if CcCanIWrite has just returned FALSE .

The post routine is defined in ntifs.h as:

typedef
VOID (*PCC_POST_DEFERRED_WRITE) (
    _In_ PVOID Context1,
    _In_ PVOID Context2
    );

This function can be called with the TopLevelIrp field in the current IRP set to FSRTL_MOD_WRITE_TOP_LEVEL_IRP.

Context1 [in]

First parameter for the post routine at PostRoutine.

Context2 [in]

Second parameter for the post routine at PostRoutine.

BytesToWrite [in]

Number of bytes of data to be written.

Retrying [in]

Set to FALSE if the request is being posted for the first time, TRUE otherwise.

Remarks

A file system would normally call CcDeferWrite after receiving a return value of FALSE from CcCanIWrite.

To cache a file, use CcInitializeCacheMap.

The context parameters passed to PostRoutine are typically the I/O request and related context data.

See also

CcCanIWrite

CcInitializeCacheMap

CcSetDirtyPageThreshold