FSDMGR_CachedWrite (Compact 2013)

3/26/2014

For a write-through cache, this function writes data to disk and to the cache.

For a write-back cache, this function writes data only to the cache and allows the lazy-writer thread to commit the data to the disk.

It is called by File System Disk Manager (FSDMGR) for disk cache.

Syntax

DWORD  FSDMGR_CachedWrite(
  DWORD dwCacheId,
  DWORD dwBlockNum,
  DWORD dwNumBlocks,
  PVOID pBuffer,
  DWORD dwWriteFlags
);

Parameters

• dwCacheId
  [in] Cache ID value returned by the FSDMGR_CreateCache function.

• dwBlockNum
  [in] Starting block to which to write.

• dwNumBlocks
  [in] Number of blocks to write.

• pBuffer
  [in] Pointer to the buffer containing data to write.

• dwWriteFlags
  [in] This value can be set to CACHE_FORCE_WRITETHROUGH to force the written blocks to be committed to the disk.

  This applies only to a write-back cache.

Return Value

ERROR_SUCCESS indicates success. A Microsoft Win32 error code indicates failure.

Remarks

If the cache location to which the data is to be written overwrites a dirty block that is different from the block to be written, that dirty block is committed to the disk.

Requirements

See Also

Reference

FSDMGR Functions
FSD Functions