d8f6601502
produced in the list ten years has some variant of internal error correction (disks, cdrom, flash), so if it has user-visible bad blocks on it the hardware has exhausted its remapping reserve and is dying, and you need to get your data off pronto. (The one exception I can think of is floppies, and I don't care.)
This is a pretty straight rip from the e2fsprogs pkg. See README's in subdirs for specific info.