NT FileSystem

1.This interface should clearly document the various interactions between the components
involved in satisfying a user request to access file data; the description must also
provide for suitable abstractions so that the many varied types of file systems can
be successfully integrated into the rest of the operating system
译：用户访问文件数据的时候，文件系统的接口必须清晰的记录了各种相关组件的关联。接口的描述必须包括文件系统中各种类型，这样可以使文件系统成功的集成到其它操作系统中去。
2.However, the file system, in turn, depends upon the Virtual Memory Manager for allocation of memory required to process file system requests.
译：然而，当向文件系统请求访问时，文件系统的运行需要依靠上层的虚拟内存管理器去分配内存。
3.The filter driver can instead focus on providing whatever
specialized functionality it needs to implement, while still
allowing the existing code to perform what it does best, provide the
original functionality.
译：在需要执行文件过滤驱动程序的时候，它反而因该集中提供诸如此类的功能，当在执行存在的代码时候，因该更好，以及提供一些原始的功能操作。
4.So if you insert your filter driver so that it intercepts I/O requests dispatched to a
file system driver, you can encrypt the data before it is passed into the file system
for transfer to secondary storage, and you can decrypt it after the file system has
retrieved the encrypted data from secondary storage, before it sends the data back
to the user.
译：因此如果你插入文件过滤驱动，截取文件系统驱动I/O请求的调度，你可以在把从二级存储器里传入到文件系统的数据进行加密，还可以把文件系统返回给二级存储器的数据解密，在发送给用户之前可以对数据进行备份。
5.If, however, you decide to intercept requests below the file system, then you
would follow the same methodology, except that now you would get a chance to
modify the buffer only after it had passed through the file system and either
before it is written out to disk (or across the network), or immediately after it has
been retrieved from disk (or from across the network), but before it is returned to
the file system.
译：如果你决定在文件系统之前截取访问，你将用到同样的方法，除了你现在要修改Buffer,修改Buffer必须要Buffer以及传输过了文件系统以及在写入磁盘之前(或访问网络)或者在磁盘返回(来自网络的访问)Buffer，但返回的Buffer是传给文件系统。