Regarding spare sectors, managed by drive electronics, and not by you or the OS, see
http://en.wikipedia.org/wiki/Bad_sector.
You can force mount the partition while in this state, and
attempt to copy off everything you want saved, to another drive. If you mount it "dirty", you should do so read-only. Please see the mount(8) manual for details.
If it were my drive, I would take the drive out of service, and write to, then read, every sector on the harddrive, to ensure that spare sectors have successfully replaced all the bad sectors, before restoring data and returning it to service. Of course, I have backups of all my drives. You should, too. But you know that....now.
(The "badblocks" program is included in the efs2progs package, which I prefer, or, you could use dd(1) with /dev/rwd1c.)