curvefs+bs: Fuse appears coredump when you start running Vdbench

[YunhuiChen]

Describe the bug (描述bug) Fuse appears coredump when you start running Vdbench

To Reproduce (复现方法) 1、sudo .curveadm/bin/curveadm mount /curvebs-new7 /home/nbs/failover/curvebs4 -c client-bs4.yaml --fstype volume 2、start vdbench 3、

Expected behavior (期望行为)

Versions (各种版本) OS: Compiler: branch: commit id:

Additional context/screenshots (更多上下文/截图)

[wu-hanqing]

might be introduced by https://github.com/opencurve/curve/pull/1390, and when reloading from a partial usable block group, BitmapAllocator::MarkUsedForBitmap do the wrong thing and causes an assert triggered.