I would try removing the attribute
from the /etc/fstab file, in the line used for the problematic Reiser partition
There is no user_xattr in the fstab file. The line reads
/dev/hdd1 /local/disk4 reiserfs defaults 1 1
And defaults is according to the man page
Use default options: rw, suid, dev, exec, auto, nouser, and async.
I also tried -onouser_xattr, which was accepted by mount as a valid option, but it didn't do any difference.
I tried -onoacl,nouser_xattr too... didn't help
Update: I can mount read-only
(forgot the easy solutions....). OK so now the files are safe, but can I easily recover the partition somehow without swapping ~60 GB of data?