Still see no issues with your 2nd use case.
root@flo-laptop:~# umount /dev/sda6 root@flo-laptop:~# mount -o ro /dev/sda6 /mnt/test/ root@flo-laptop:~# touch /mnt/test/test touch: cannot touch `/mnt/test/test': Read-only file system root@flo-laptop:~# mount -o remount,rw /dev/sda6 /mnt/test/ root@flo-laptop:~# touch /mnt/test/test root@flo-laptop:~#
Still see no issues with your 2nd use case.
root@flo-laptop:~# umount /dev/sda6
root@flo-laptop:~# mount -o ro /dev/sda6 /mnt/test/
root@flo-laptop:~# touch /mnt/test/test
touch: cannot touch `/mnt/test/test': Read-only file system
root@flo-laptop:~# mount -o remount,rw /dev/sda6 /mnt/test/
root@flo-laptop:~# touch /mnt/test/test
root@flo-laptop:~#