idr_replace
old = idr_replace(&fpriv->bo_list_handles, list, handle);
idr_replace(&file_priv->master->magic_map, NULL, auth->magic);
if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
idr_replace(&drm_minors_idr, minor, minor->index);
idr_replace(&drm_minors_idr, NULL, minor->index);
obj = idr_replace(&filp->object_idr, NULL, handle);
idr_replace(&dev->mode_config.crtc_idr, obj, obj->id);
void *idr_replace(struct idr *idp, void *ptr, int id);