CTLBLK_HALF_SEGS
&beio->sg_segs[i + CTLBLK_HALF_SEGS],
ctl_set_kern_data_ptr(io, &beio->sg_segs[CTLBLK_HALF_SEGS]);
&beio->sg_segs[i + CTLBLK_HALF_SEGS]);
beio->sg_segs[i + CTLBLK_HALF_SEGS].addr,