How to hang a chair from the ceiling joists (with attic access)
Don't use an eye bolt! Anyone who swings in the chair, especially in a circular motion, will take the bolt right out of the nut, through the joist, and into the floor. How do I know? Because both of my kids managed to do this with two different hanging chairs.
There is a part which can be described as such:

A steel plate that attaches to the joist through drywall with four bolts. In the center of the plate is a swivel hook, to which you attach a latch.

The swivel part ensures that the swinging motion is localized and doesn't move an eye bolt, allowing it to unscrew itself.