Is it permissible to fast six days of Shawwal for someone who has to make up for missed fasts from Ramadan?

Scholars have differed regarding the permissibility of voluntary fasting before making up for missed Ramadan fasts. Many have held it permissible without dislike (makrooh), while the Malikis and Shafi'is deemed it permissible with dislike. The Hanbalis, however, considered it forbidden and the voluntary fast invalid, citing a weak hadith. The preponderant view is that it is permissible, based on the Almighty's saying: "And whoever is ill or on a journey, then [he must fast] an equal number of other days," and based on the action of Aisha (may Allah be pleased with her), who used to make up her Ramadan fasts in Sha'ban. However, fasting the six days of Shawwal is different; whoever desires its reward must first make up for Ramadan, so that he may have completed the fasting of Ramadan.