DBUFS_UNSET
if ((data->objset == DBUFS_UNSET || data->objset == objset) &&
(data->object == DBUFS_UNSET || data->object == db.db_object) &&
(data->level == DBUFS_UNSET || data->level == level) &&
(data->blkid == DBUFS_UNSET || data->blkid == blkid)) {
data.objset = data.object = data.level = data.blkid = DBUFS_UNSET;