Kai Krakow [off-list ref] schrieb:

Interestingly, the filesystem was not unmountable - system hung. After
reisub and checking again with "btrfs scrub" no errors where reported and
it just rsync'ed fine this time. This does not make sense to me.

btrfsck still shows a lot of errors, while scrubbing says everything is 
okay... *sigh

Now, how should one fix it if there is still no repair utility? I'm pretty 
sure sooner or later I will run into a BUG_ON again...

Thanks,
Kai