Laura Dern -– I've Had It, Ben Harper Divorce Back On

Laura Dern has thrown in the towel in her marriage to Ben Harper – she has filed legal papers reactivating the dormant divorce ... TMZ has learned.

Dern filed her formal legal response to Harper’s divorce petition Friday in LA County Superior Court. In the docs, filed by Disso Queen Laura Wasser, Dern is asking for primary physical custody of the couple’s two kids and joint legal custody. She is also seeking spousal support, child support, and attorneys fees.

As TMZ first reported, Harper blindsided Dern with divorce papers back in 2010 after 5 years of marriage and two children. But the divorce was never finalized and earlier this year they tried reconciling.

Sources tell us that the reconciliation was “very rocky” and Dern now wants out.

FYI – Dern is already the primary caregiver for the couple’s two kids. But we're told she also plays a significant role in raising Harper's two other children from a prior marriage.