I don’t know when this happened. There was a system update a few days ago which went fine. Two days ago I wanted to download something onto one of my HDDs and got an I/O error. After investigating I found out that I no longer am the owner of any of my drives and can’t create/delete any files. Chmod/chown didn’t help. Editing the fstab file didn’t help since it had the exact same contens as when everything worked. Shuffeling exec,rw around has no effect. Mounting/unmounting didn’t do anything. Phisically removing the drives also didn’t work. Adding a completely new drive automatically set it to restricted. How the hell does soemthing like this happen? I don’t want to do a system wipe.
Edit: Windows is to blame
It appears Windows did something to the drives the last time I used it which messed up the partitin tables and prevented Linux from mounting them correctly. After poking around in the journalctl like suggested I found an entry with the error message. Googling brought me to an arch forum post with the same problem. All that had to be done was to go back into Windows and run shutdown /s /f /t 0
in cmd/powershell.
Link to the post: https://bbs.archlinux.org/viewtopic.php?id=231375
Tnx everyone for the assistance!
Fastboot was never enabled to begin with :-/