*/
bfqg->bfqd = bfqd;
bfqg->active_entities = 0;
+ bfqg->online = true;
bfqg->rq_pos_tree = RB_ROOT;
}
entity->sched_data = &parent->sched_data;
}
-static struct bfq_group *bfq_lookup_bfqg(struct bfq_data *bfqd,
- struct blkcg *blkcg)
+static void bfq_link_bfqg(struct bfq_data *bfqd, struct bfq_group *bfqg)
{
- struct blkcg_gq *blkg;
-
- blkg = blkg_lookup(blkcg, bfqd->queue);
- if (likely(blkg))
- return blkg_to_bfqg(blkg);
- return NULL;
-}
-
-struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd,
- struct blkcg *blkcg)
-{
- struct bfq_group *bfqg, *parent;
+ struct bfq_group *parent;
struct bfq_entity *entity;
- bfqg = bfq_lookup_bfqg(bfqd, blkcg);
-
- if (unlikely(!bfqg))
- return NULL;
-
/*
* Update chain of bfq_groups as we might be handling a leaf group
* which, along with some of its relatives, has not been hooked yet
bfq_group_set_parent(curr_bfqg, parent);
}
}
+}
- return bfqg;
+struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio)
+{
+ struct blkcg_gq *blkg = bio->bi_blkg;
+ struct bfq_group *bfqg;
+
+ while (blkg) {
+ bfqg = blkg_to_bfqg(blkg);
+ if (bfqg->online) {
+ bio_associate_blkg_from_css(bio, &blkg->blkcg->css);
+ return bfqg;
+ }
+ blkg = blkg->parent;
+ }
+ bio_associate_blkg_from_css(bio,
+ &bfqg_to_blkg(bfqd->root_group)->blkcg->css);
+ return bfqd->root_group;
}
/**
{
struct bfq_entity *entity = &bfqq->entity;
+ /*
+ * oom_bfqq is not allowed to move, oom_bfqq will hold ref to root_group
+ * until elevator exit.
+ */
+ if (bfqq == &bfqd->oom_bfqq)
+ return;
/*
* Get extra reference to prevent bfqq from being freed in
* next possible expire or deactivate.
* Move bic to blkcg, assuming that bfqd->lock is held; which makes
* sure that the reference to cgroup is valid across the call (see
* comments in bfq_bic_update_cgroup on this issue)
- *
- * NOTE: an alternative approach might have been to store the current
- * cgroup in bfqq and getting a reference to it, reducing the lookup
- * time here, at the price of slightly more complex code.
*/
-static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd,
- struct bfq_io_cq *bic,
- struct blkcg *blkcg)
+static void *__bfq_bic_change_cgroup(struct bfq_data *bfqd,
+ struct bfq_io_cq *bic,
+ struct bfq_group *bfqg)
{
struct bfq_queue *async_bfqq = bic_to_bfqq(bic, 0);
struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, 1);
- struct bfq_group *bfqg;
struct bfq_entity *entity;
- bfqg = bfq_find_set_group(bfqd, blkcg);
-
- if (unlikely(!bfqg))
- bfqg = bfqd->root_group;
-
if (async_bfqq) {
entity = &async_bfqq->entity;
}
if (sync_bfqq) {
- entity = &sync_bfqq->entity;
- if (entity->sched_data != &bfqg->sched_data)
- bfq_bfqq_move(bfqd, sync_bfqq, bfqg);
+ if (!sync_bfqq->new_bfqq && !bfq_bfqq_coop(sync_bfqq)) {
+ /* We are the only user of this bfqq, just move it */
+ if (sync_bfqq->entity.sched_data != &bfqg->sched_data)
+ bfq_bfqq_move(bfqd, sync_bfqq, bfqg);
+ } else {
+ struct bfq_queue *bfqq;
+
+ /*
+ * The queue was merged to a different queue. Check
+ * that the merge chain still belongs to the same
+ * cgroup.
+ */
+ for (bfqq = sync_bfqq; bfqq; bfqq = bfqq->new_bfqq)
+ if (bfqq->entity.sched_data !=
+ &bfqg->sched_data)
+ break;
+ if (bfqq) {
+ /*
+ * Some queue changed cgroup so the merge is
+ * not valid anymore. We cannot easily just
+ * cancel the merge (by clearing new_bfqq) as
+ * there may be other processes using this
+ * queue and holding refs to all queues below
+ * sync_bfqq->new_bfqq. Similarly if the merge
+ * already happened, we need to detach from
+ * bfqq now so that we cannot merge bio to a
+ * request from the old cgroup.
+ */
+ bfq_put_cooperator(sync_bfqq);
+ bfq_release_process_ref(bfqd, sync_bfqq);
+ bic_set_bfqq(bic, NULL, 1);
+ }
+ }
}
return bfqg;
void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio)
{
struct bfq_data *bfqd = bic_to_bfqd(bic);
- struct bfq_group *bfqg = NULL;
+ struct bfq_group *bfqg = bfq_bio_bfqg(bfqd, bio);
uint64_t serial_nr;
- rcu_read_lock();
- serial_nr = __bio_blkcg(bio)->css.serial_nr;
+ serial_nr = bfqg_to_blkg(bfqg)->blkcg->css.serial_nr;
/*
* Check whether blkcg has changed. The condition may trigger
* spuriously on a newly created cic but there's no harm.
*/
if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr))
- goto out;
+ return;
- bfqg = __bfq_bic_change_cgroup(bfqd, bic, __bio_blkcg(bio));
+ /*
+ * New cgroup for this process. Make sure it is linked to bfq internal
+ * cgroup hierarchy.
+ */
+ bfq_link_bfqg(bfqd, bfqg);
+ __bfq_bic_change_cgroup(bfqd, bic, bfqg);
/*
* Update blkg_path for bfq_log_* functions. We cache this
* path, and update it here, for the following
*/
blkg_path(bfqg_to_blkg(bfqg), bfqg->blkg_path, sizeof(bfqg->blkg_path));
bic->blkcg_serial_nr = serial_nr;
-out:
- rcu_read_unlock();
}
/**
put_async_queues:
bfq_put_async_queues(bfqd, bfqg);
+ bfqg->online = false;
spin_unlock_irqrestore(&bfqd->lock, flags);
/*
bfq_end_wr_async_queues(bfqd, bfqd->root_group);
}
-struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, struct blkcg *blkcg)
+struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio)
{
return bfqd->root_group;
}
projects / mirror_ubuntu-jammy-kernel.git / blobdiff