The very first words in the smoke/fire/fumes procedure I have to hand (and I think they are all similar in intent) is:
WARNING.
Time is critical during smoke/fire/fumes emergencies.
If that's not enough to get your attention, later on (in the event of the situation being "uncontrolled" i.e. you can't get the fire out by various means)
... the crew should expedite the landing. The crew should also consider an overweight landing, tailwind landing, ditching or a forced off-airport landing
With considerations like that, worrying about dumping fuel, or where you are dumping it, are very much secondary. What I've quoted is pretty much the AFM-speak version of JFP's LAND NOW.