aio

1、一般来说，设备驱动程序不需要实现aio_fsync 。

2、As a general rule, device drivers will not need to implement aio_fsync .

3、The aio_fsync() method serves the same purpose as the fsync() method; its purpose is to ensure that all pending data are written to disk.

4、aio_fsync()的目的与fsync()相同：确保所有未决的数据都写入到磁盘了。