Moderate localized water damage that's hard to inspect from above
I don’t see ANY discoloration (black stains, etc.) on the studs or roof joists. Therefore, it’s minor and hasn’t damaged the wood structurally or caused mold. 

The damage is what I’d classify as insignificant. It’s not worth tearing up your attic to see the damage from “above”. 

If you’re not sure you’ve stopped the leak, you could take an ink pen (a pencil won’t work) and draw an outline around the perimeter of the leak/stain. Keep an eye on it for one rainy season, then fix the ceiling. If it leaks again, keep a journal and make note if it leaks during heavy rain, strong winds, rain coming from the west, etc. It’ll help you find the “real” leak later.