Did I mention that all this loop blkcg integration is complete and utter
garbage and should have never been merged?
> struct list_head *cmd_list;
> + struct cgroup_subsys_state *blkcg_css = NULL;
> +#ifdef CONFIG_BLK_CGROUP
> + struct request *rq = blk_mq_rq_from_pdu(cmd);
> +
> + if (rq->bio && rq->bio->bi_blkg)
> + blkcg_css = &bio_blkcg(rq->bio)->css;
> +#endif
This kind of junk has no business in a driver. The blkcg code
need to provide a helper for retreiving the blkcg_css from a request,
including a stub for the the !CONFIG_BLK_CGROUP case.
> cur_worker = container_of(*node, struct loop_worker, rb_node);
> - if (cur_worker->blkcg_css == cmd->blkcg_css) {
> + if (cur_worker->blkcg_css == blkcg_css) {
> worker = cur_worker;
> break;
> - } else if ((long)cur_worker->blkcg_css < (long)cmd->blkcg_css) {
> + } else if ((long)cur_worker->blkcg_css < (long)blkcg_css) {
No need for an else after a break. And more importantly no need to cast
a pointer to compare it to another pointer of the same type.
> + struct mem_cgroup *old_memcg = NULL;
> + struct cgroup_subsys_state *memcg_css = NULL;
> +
> + kthread_associate_blkcg(worker->blkcg_css);
> +#ifdef CONFIG_MEMCG
> + memcg_css = cgroup_get_e_css(worker->blkcg_css->cgroup,
> + &memory_cgrp_subsys);
> +#endif
> + if (memcg_css)
> + old_memcg = set_active_memcg(
> + mem_cgroup_from_css(memcg_css));
> +
This kind of crap also has absolutely no business in a block driver
and the memcg code should provide a proper helper.
