I'm having the problem described here. But in my case the drive in question is already mounted, yet the link to something on that drive is broken. I never mounted the drive manually, yet it's mounted. It's not in /etc/fstab either, so I guess it was maybe mounted by udisks. If I follow the advice in this answer to the above question, I'm afraid that both /etc/fstab and udisks will try to mount to the same place, resulting in problems.
Also, since the drive in question is present in /etc/mtab, I'm tempted to simply copy its line into /etc/fstab instead of trying to construct the correct line myself.
Is it safe to simply copy that line from /etc/mtab into /etc/fstab and not worry about other services like udisks attempting to mount into the same dir?