CcDeferWrite function (ntifs.h)
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.
Syntax
void CcDeferWrite(
[in] PFILE_OBJECT FileObject,
[in] PCC_POST_DEFERRED_WRITE PostRoutine,
[in] PVOID Context1,
[in] PVOID Context2,
[in] ULONG BytesToWrite,
[in] BOOLEAN Retrying
);
Parameters
[in] FileObject
Pointer to a file object for the cached file to which the data is to be written.
[in] PostRoutine
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.
[in] Context1
First parameter for the post routine at PostRoutine.
[in] Context2
Second parameter for the post routine at PostRoutine.
[in] BytesToWrite
Number of bytes of data to be written.
[in] Retrying
Set to FALSE if the request is being posted for the first time, TRUE otherwise.
Return value
None
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.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Universal |
| Header | ntifs.h (include Ntifs.h) |
| Library | NtosKrnl.lib |
| DLL | NtosKrnl.exe |