> Is there anything ringing a bell to someone here? Yes, but I guess that doesn't help. I experienced something remotely similar after a disc firmware crash followed by a mpt(4) lockup (before I wrote the timeout recovery buhrow@ committed). I would get a "mangled directory" panic on the same directory again and again; fsck repaired it but found nothing else. I was just short of dump/newfs/restore, but then something (I guess removing that directory) helped. That was on a FFSv2, though.
> Any explanation? No. Only that apparently, an FFS can be inconsistent in a way fsck doesn't recognize.