blk-cgroup: fix rcu lockdep warning in blkg_lookup()

Browse source

[ Upstream commit 393cd8ffd8 ]

blkg_lookup() is called with either queue_lock or rcu read lock, so
use rcu_dereference_check(lockdep_is_held(&q->queue_lock)) for
retrieving 'blkg', which way models the check exactly for covering
queue lock or rcu read lock.

Fix lockdep warning of "block/blk-cgroup.h:254 suspicious rcu_dereference_check() usage!"
from blkg_lookup().

Tested-by: Changhui Zhong <czhong@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Fixes: 83462a6c97 ("blkcg: Drop unnecessary RCU read [un]locks from blkg_conf_prep/finish()")
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231219012833.2129540-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

Ming Lei 2023-12-19 09:28:33 +08:00 • committed by Greg Kroah-Hartman

parent ad0b398069

commit 77fcddb6be

1 changed files with 2 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

3

block/blk-cgroup.h

View file