linux 弹出光驱失败

[root@NB media]# eject #弹出光驱的命令
umount: /media/____: device is busy.
        (In some cases useful info about processes that use
         the device is found by lsof(8) or fuser(1))
eject: unmount of `/media/____‘ failed
[root@NB media]# fuser -m -v /media/____/
Cannot stat file /proc/20516/fd/5: No such file or directory
                     USER        PID ACCESS COMMAND
/media/____/:        root      20502 ..c.. su
                     root      20505 ..c.. bash
                     root      20516 ..c.. iotop
[root@NB media]# fuser -m -k /media/____/
Cannot stat file /proc/20516/fd/5: No such file or directory
/media/____/:        20502c 20505c 20516c
[root@NB media]# eject #弹出成功