if (o->write_iolog_file && o->read_iolog_file) {
log_err("fio: read iolog overrides write_iolog\n");
free(o->write_iolog_file);
if (o->write_iolog_file && o->read_iolog_file) {
log_err("fio: read iolog overrides write_iolog\n");
free(o->write_iolog_file);