abc@endless:~$ sudo mount /dev/sda3 /mnt
mount: /dev/sda3 is already mounted or /mnt busy
       /dev/sda3 is already mounted on /run/media/abc/ostree
       /dev/sda3 is already mounted on /mnt
abc@endless:~$ ls /mnt
boot  dev  flatpak  home  lost+found  ostree  proc  root  run  sys  tmp
abc@endless:~$ ^C
abc@endless:~$