上下滑動的swiper，第二個slider高度大於屏幕，如何讓它出現滾動條，像單頁面那樣滑動？？

https://segmentfault.com/q/1010000005605451/a-1020000009012368/revision

HTML：
<div class="swiper-container swiper-container-v">
    <div class="swiper-wrapper">
        <div class="swiper-slide">Vertical Slide 1</div>
        <div class="swiper-slide">
            <div class="swiper-container swiper-container-scrollbar">
                <div class="swiper-wrapper">
                    <div class="swiper-slide">
                        <h3>title</h3>
                        <p>this is a p tag</p>
                        .....
                        .....
                        .....
                    </div>
                </div>
                <div class="swiper-scrollbar"></div>
            </div>
        </div>
        <div class="swiper-slide">Vertical Slide 3</div>
        <div class="swiper-slide">Vertical Slide 4</div>
    </div>
</div>



CSS：
html, body{
    height: 100%;
}
.swiper-container{
    width: 100%;
    height: 100%;
}
.swiper-container-scrollbar .swiper-slide{
    height: auto;
}



JavaScript:
var swiperV = new Swiper('.swiper-container-v', {
    direction: 'vertical'
});

var swiperScrollbar = new Swiper('.swiper-container-scrollbar', {
    scrollbar: '.swiper-container-scrollbar .swiper-scrollbar',
    direction: 'vertical',
    slidesPerView: 'auto',
    mousewheelControl: true,
    freeMode: true,
    nested: true
});