Set /home/jovyan as read only for jovyan user

Yes, so because the system does not allow saving files under HOME, but allows saving files under HOME/work

So I do not want to have the users create files under HOME, and then they don’t understand why the files are not there the next time they open the notebook

So I want to set in the notebook, that the user will get a popup with an error when they try to save a file under HOME (not only in the host machine)