Halle Berry Fighting Legal Battle ... In a BIKINI

At the same time Halle Berry was frolicking around Spain in a teeny, tiny AWESOME bikini ... she was sending her lawyers into battle back in L.A.; to once again fight her baby daddy Gabriel Aubry.
 

Aubry, who is also in Europe, has been throwing a fit over custody issues involving their daughter Nahla while Halle shoots "Cloud Atlas" in Europe -- and we've learned, Halle's lawyers were in court today to put out the flames.