How can I patch the ceiling and rehang a shower curtain rod?
Realizing none of this is intended to support a person, or animal, or support anything over a person or animal.

Which answer would you like?

In order of suggested preference, and holding strength


Open up the ceiling enough [24" x 8"] to get a piece of lumber screwed between 2 joists - then patch
Open up the ceiling enough [10" x 6"] to get a piece of lumber laying between 2 joists - then patch
Open up the ceiling enough [8" Circle] to get a fan support bracket between the joists then patch
Open up the ceiling enough [6" x 6"] to get a large piece of drywall on top of ceiling, for 2 layer patch