linux文件过滤驱动程序，实现文件透明加解密-linux file system filter driver, to achieve transparent encryption file

linux下文件过滤驱动程序，可以实现在linux内核态下加解密的速度比应用层翻一倍。-the file filter driver linux, linux kernel can be achieved in the state than the speed of encryption and decryption application layer double.