umount 报错umount: /new_room: target is busy. (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1))

挂载逻辑卷后，尝试更新逻辑卷的文件系统

[root@server lost+found]# umount /new_room/
umount: /new_room: target is busy.
        (In some cases useful info about processes that use
         the device is found by lsof(8) or fuser(1))

报错说繁忙
上网查 发现我进入了挂载目录

[root@server lost+found]# cd 
[root@server ~]# umount /new_room/

完成卸载