diff options
author | Ming Lei <ming.lei@redhat.com> | 2023-11-17 05:35:22 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-12-20 17:38:02 +0300 |
commit | 6c97b28b013b533305848954e3e9c797217d60fe (patch) | |
tree | fdeb6753fb87c0b9c492a91c7d74daeb8fc65ce1 | |
parent | 123e44b9a49a42ff5313ec65256f1540d7c52fa0 (diff) | |
download | linux-6c97b28b013b533305848954e3e9c797217d60fe.tar.xz |
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>
-rw-r--r-- | block/blk-throttle.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 853b1770df36..e58c03c504c1 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1383,6 +1383,7 @@ 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 @@ -1410,6 +1411,7 @@ 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 |