If you’re stuck in the frozen state, you can Ctrl+alt+delete 7+ times quickly to tell systemd to try to restart the system.
Less destructive way would be to try to open a terminal session with ctr+alt+f3 (or any f key) If it's only the gui that's frozen. Makes it also possible to troubleshoot things from there. I had this issue recently. AMD core boost caused random freezes to kwin.
Double yikes. That almost by definition means cloud and data storage in god knows where. Somebody really wants that sweet sweet profitable metadata.