Cloned this bug as It was technically never possible to move bz 1347251 - IO error seen with Rolling or non-disruptive upgrade of an distribute-disperse(EC) volume from 3.1.2 to 3.1.3 to verified, as the fix is available in 3.2 and not on 3.1.3 Hence I will change the title of bz 1347251 accordingly
as the underlying problem of rolling upgrade has been fixed, I will be moving bz 1347251 to verfied THis bug will be moved to as can't fix as it is theoritically not possible to have a rolling upgrade from 3.1.2 to 3.1.3