buildContainerRootfs don't call bindMountContainerRootfs if container's rootfs use devicemapper device in https://github.com/kata-containers/runtime/blob/master/virtcontainers/kata_agent.go#L1300, so bindUnmountContainerRootfs should not be called if container's rootfs use devicemapper device in https://github.com/kata-containers/runtime/blob/master/virtcontainers/container.go#L1123