Linda Lovelace claimed she was forced to play the lead in this movie. An obvious lie to anyone who saw the movie as no one could be forced to do what she did without having practiced it for a long while. Lovelace made a lot of claims and tried to clean up her reputation as she grew older. I suupose that is normal as a lot of mistakes are made when we are young we all wish we could deny or correct,unfortunately hers are on film.
http://www.rotten.com/library/bio/entertainers/actors/linda-lovelace/
Linda Lovelace claimed that her then husband kept her drugged and while she did those things in the movie voluntarily she was, nonetheless, drugged throughout that period of her life, if you want to believe her.
She also said that while it was voluntary, she didn't remember an awful lot of it. I do know that she did divorce him shortly after the movie became famous.
She also claimed that she had no remembrance whatsoever of the Playboy photographer taking her pics for the centerfold thing.
I gave to her the benefit of the doubt.