@firstname.lastname@example.org Yeah, it seems like that should never happen under any circumstances but that’s the best explanation I can come up with for what happened and once I fixed the space issue the other problems went away. That particular filesystem is on a LUKS device on a disk image served with NBD. The machine in question and the NBD server are both on Arch Linux so it has potentially unstable versions of all the software involved.
It’s a real house of cards and I’m not surprised something like this happened. I’m keeping lots of backups. My setup is pretty unique but I stand by my original post. Running out of space on Btrfs isn’t fun, even when it’s functioning properly.