block, bfq: cleanup 'bfqg->online'

After commit dfd6200a0954 ("blk-cgroup: support to track if policy is
online"), there is no need to do this again in bfq.

However, 'pd->online' is not protected by 'bfqd->lock', in order to make
sure bfq won't see that 'pd->online' is still set after bfq_pd_offline(),
clear it before bfq_pd_offline() is called. This is fine because other
polices doesn't use 'pd->online' and bfq_pd_offline() will move active
bfqq to root cgroup anyway.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230202134913.2364549-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index 4fdbbec71647f9b5ee7177abe04ffe5c3de2b897..624530643a05cd877caa5338f43375bb3edb08ba 100644 (file)
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -551,7 +551,6 @@ static void bfq_pd_init(struct blkg_policy_data *pd)
        bfqg->bfqd = bfqd;
        bfqg->active_entities = 0;
        bfqg->num_queues_with_pending_reqs = 0;
-       bfqg->online = true;
        bfqg->rq_pos_tree = RB_ROOT;
 }
 
@@ -614,7 +613,7 @@ struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio)
                        continue;
                }
                bfqg = blkg_to_bfqg(blkg);
-               if (bfqg->online) {
+               if (bfqg->pd.online) {
                        bio_associate_blkg_from_css(bio, &blkg->blkcg->css);
                        return bfqg;
                }
@@ -985,7 +984,6 @@ static void bfq_pd_offline(struct blkg_policy_data *pd)
 
 put_async_queues:
        bfq_put_async_queues(bfqd, bfqg);
-       bfqg->online = false;
 
        spin_unlock_irqrestore(&bfqd->lock, flags);
        /*

diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
index 75cc6a3242679cf3c67edc5fe45fa2f70eca51be..69aaee52285a672a7fa0f71e0fdba0950ccce195 100644 (file)
--- a/block/bfq-iosched.h
+++ b/block/bfq-iosched.h
@@ -1009,8 +1009,6 @@ struct bfq_group {
 
        /* reference counter (see comments in bfq_bic_update_cgroup) */
        refcount_t ref;
-       /* Is bfq_group still online? */
-       bool online;
 
        struct bfq_entity entity;
        struct bfq_sched_data sched_data;

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index c46778d1f3c27de10c4ccc359760ec24b74ff335..d8fe607138b96d0d0cf095fa034a72b59ae0577d 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -479,9 +479,9 @@ static void blkg_destroy(struct blkcg_gq *blkg)
                struct blkcg_policy *pol = blkcg_policy[i];
 
                if (blkg->pd[i] && blkg->pd[i]->online) {
+                       blkg->pd[i]->online = false;
                        if (pol->pd_offline_fn)
                                pol->pd_offline_fn(blkg->pd[i]);
-                       blkg->pd[i]->online = false;
                }
        }