BOOLEAN
NpFastWrite(
  IN  PFILE_OBJECT FileObject,
  IN  PLARGE_INTEGER FileOffset,
  IN  ULONG Length,
  IN  BOOLEAN Wait,
  IN  ULONG LockKey,
  IN  PVOID Buffer,
  OUT PIO_STATUS_BLOCK IoStatus,
  IN  PDEVICE_OBJECT DeviceObject
  );

Routine Description:

    This routine does a fast write bypassing the usual file system
    entry routine (i.e., without the Irp).

Arguments:

    FileObject - Pointer to the file object being read.

    FileOffset - Byte offset in file for desired data.

    Length - Length of desired data in bytes.

    Wait - FALSE if caller may not block, TRUE otherwise

    LockKey - Supplies the Key used to use if the byte range being read is locked.

    Buffer - Pointer to output buffer to which data should be copied.

    IoStatus - Pointer to standard I/O status block to receive the status
               for the transfer.

Return Value:

    BOOLEAN - TRUE if the operation completed successfully and FALSE if the
        caller needs to take the long IRP based route.