resync_info_update
ret = resync_info_update(mddev, 0, 0);
.resync_info_update = resync_info_update,
int (*resync_info_update)(struct mddev *mddev, sector_t lo, sector_t hi);
mddev->cluster_ops->resync_info_update(mddev,
mddev->cluster_ops->resync_info_update(mddev,
mddev->cluster_ops->resync_info_update(mddev,
mddev->cluster_ops->resync_info_update(mddev, conf->cluster_sync_low,