wdm下如何复制文件

已知一文件句柄，需要创建一个新文件，并复制文件内容。
我的做法如下，瞎想的过程，肯定不对：
#include <ntddk.h>

NTSTATUS copyfile(HANDLE hdIn, WCHAR pszFilePathName[PATHNAMEMAX]){
NTSTATUS ntstatus;
UNICODE_STRING filename;
HANDLE hf=0;
IO_STATUS_BLOCK IoOutStatusBlock;
IO_STATUS_BLOCK IoInStatusBlock;
OBJECT_ATTRIBUTES ObjectAttributes;
FILE_POSITION_INFORMATION FileOutInformation;
FILE_POSITION_INFORMATION FileInInformation;
LARGE_INTEGER nOffSet;
FILE_STANDARD_INFORMATION stdinf;
char buffer[READFILELEN];
char pszSize[256];
int i = 0;

RtlInitUnicodeString(
&filename,
pszFilePathName
);
InitializeObjectAttributes(
&ObjectAttributes,
&filename,
OBJ_CASE_INSENSITIVE,
NULL,
NULL
);
ntstatus=ZwCreateFile(
&hf,
GENERIC_WRITE|SYNCHRONIZE|GENERIC_READ,
&ObjectAttributes,
&IoOutStatusBlock,
0,
FILE_ATTRIBUTE_NORMAL,
FILE_SHARE_DELETE,
FILE_OPEN_IF,
FILE_SYNCHRONOUS_IO_NONALERT,
NULL,
0
);
if (!NT_SUCCESS(ntstatus)){
return ntstatus;
}
do {
nOffSet = RtlConvertLongToLargeInteger(READFILELEN * i);

ZwReadFile(
hdIn,
0,
0,
0,
&IoInStatusBlock,
buffer,
READFILELEN,
&nOffSet,
NULL
);

//write from buffer
ZwWriteFile(
hf,
0,
0,
0,
&IoOutStatusBlock,
buffer,
READFILELEN,
NULL,
NULL
);

i++;
}
while (READFILELEN == IoInStatusBlock.Information);
ZwClose(hf);
return IoOutStatusBlock.Status;
}
谁能告诉我正确的做法。刚开始接触这个层次的编程。有源码最好了
谢谢

[编辑 -  6/3/04 by  popwalking]

[编辑 -  6/3/04 by  popwalking]

我也是这么做的,不过我更狠一下子读完,再一下子写,哈哈,不用写循环了.
有没有更好的方法?