I'm not sure how much will that rate on the intuitiveness scale. Some people might not realize right away that it's editable.
I think if you set the field to be non-editable first (so it's greyed out), and make a button beside it that says "Rename", and when the button is pressed make the field editable, would work better.
I agree, this option should be provided: I had to rename an external drive manually once, so the need for the feature is real. But only admins should be allowed to modify the drive label.