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authorMing Lei <ming.lei@redhat.com>2023-11-17 10:35:22 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-12-20 15:44:31 +0100
commitdbf0cdacdb4ebd68bf60dcd1a8b0d20dcdab1fbd (patch)
treea9300dc25e737e92411b81c836f5f99d36c505a3 /block
parentd69581c17608d81824dd497d9a54b6a5b6139975 (diff)
blk-throttle: fix lockdep warning of "cgroup_mutex or RCU read lock required!"
[ Upstream commit 27b13e209ddca5979847a1b57890e0372c1edcee ] Inside blkg_for_each_descendant_pre(), both css_for_each_descendant_pre() and blkg_lookup() requires RCU read lock, and either cgroup_assert_mutex_or_rcu_locked() or rcu_read_lock_held() is called. Fix the warning by adding rcu read lock. Reported-by: Changhui Zhong <czhong@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20231117023527.3188627-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'block')
-rw-r--r--block/blk-throttle.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index c526fdd0a7b9..4bf514a7bd82 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1409,6 +1409,7 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
tg_bps_limit(tg, READ), tg_bps_limit(tg, WRITE),
tg_iops_limit(tg, READ), tg_iops_limit(tg, WRITE));
+ rcu_read_lock();
/*
* Update has_rules[] flags for the updated tg's subtree. A tg is
* considered to have rules if either the tg itself or any of its
@@ -1436,6 +1437,7 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
this_tg->latency_target = max(this_tg->latency_target,
parent_tg->latency_target);
}
+ rcu_read_unlock();
/*
* We're already holding queue_lock and know @tg is valid. Let's