[PATCH AUTOSEL 5.4 4/6] blk-cgroup: fix missing pd_online_fn() while activating policy

[Sasha Levin]

From: Yu Kuai <yukuai3@xxxxxxxxxx>

[ Upstream commit e3ff8887e7db757360f97634e0d6f4b8e27a8c46 ]

If the policy defines pd_online_fn(), it should be called after
pd_init_fn(), like blkg_create().

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230103112833.2013432-1-yukuai1@xxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 block/blk-cgroup.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index dde8d0acfb34..cd085a0e5e4a 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1445,6 +1445,10 @@ int blkcg_activate_policy(struct request_queue *q,
 		list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
 			pol->pd_init_fn(blkg->pd[pol->plid]);
 
+	if (pol->pd_online_fn)
+		list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
+			pol->pd_online_fn(blkg->pd[pol->plid]);
+
 	__set_bit(pol->plid, q->blkcg_pols);
 	ret = 0;
 
-- 
2.39.0