解决 umount ：target is busy 挂载盘卸载不掉的问题

[root@openGauss ~]#  dd if=/dev/zero of=mo.img bs=5120k count=1 
[root@openGauss ~]#  ls -lh mo.img 
-rw-r--r-- 1 root root 5.0M Dec 28 22:37 mo.img
[root@openGauss ~]#  mkfs -t ext4  -F ./mo.img 
... 
OS type: Linux 
Block size=1024 (log=0) 
Fragment size=1024 (log=0) 
Stride=0 blocks, Stripe width=0 blocks 
1280 inodes, 5120 blocks 
256 blocks (5.00%) reserved for the super user 
... 
... 
Writing superblocks and filesystem accounting information: done 
[root@openGauss ~]#  mount -o loop ./mo.img /mnt 

[root@openGauss ~]#  umount /mnt
umount: /mnt: target is busy.
        (In some cases useful info about processes that use
         the device is found by lsof(8) or fuser(1))
[root@openGauss ~]# 
[root@openGauss ~]# fuser -mv /mnt/
                     USER        PID ACCESS COMMAND
/mnt:                root     kernel mount /mnt
                     root        518 ..c.. bash
[root@openGauss ~]# 
[root@openGauss ~]#  lsof /mnt/
COMMAND PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
bash    518 root  cwd    DIR    7,0    30720    2 /mnt
[root@openGauss ~]# 
[root@openGauss ~]# fuser -kv /mnt/
                     USER        PID ACCESS COMMAND
/mnt:                root     kernel mount /mnt
                     root        518 ..c.. bash
[root@openGauss ~]#  fuser -mv /mnt/
                     USER        PID ACCESS COMMAND
/mnt:                root     kernel mount /mnt
[root@openGauss ~]# lsof /mnt/

————————————————————————————
公众号：JiekeXu之路
墨天轮：https://www.modb.pro/u/4347
CSDN ：https://blog.csdn.net/JiekeXu
腾讯云：https://cloud.tencent.com/developer/user/5645107
————————————————————————————