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blk-cgroup: Remove unnecessary rcu_read_lock/unlock()

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spin_lock_irq/spin_unlock_irq contains preempt_disable/enable().
Which can serve as RCU read-side critical region, so remove
rcu_read_lock/unlock().

Signed-off-by: Fanjun Kong <bh1scw@gmail.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220516173930.159535-1-bh1scw@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Fanjun Kong 2022-05-17 01:39:30 +08:00 committed by Jens Axboe
parent 3607849df4
commit 77c570a1ea
1 changed files with 1 additions and 3 deletions
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4
block/blk-cgroup.c
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@ -1278,14 +1278,13 @@ int blkcg_init_queue(struct request_queue *q)
preloaded = !radix_tree_preload(GFP_KERNEL); preloaded = !radix_tree_preload(GFP_KERNEL);
/* Make sure the root blkg exists. */ /* Make sure the root blkg exists. */
rcu_read_lock(); /* spin_lock_irq can serve as RCU read-side critical section. */
spin_lock_irq(&q->queue_lock); spin_lock_irq(&q->queue_lock);
blkg = blkg_create(&blkcg_root, q, new_blkg); blkg = blkg_create(&blkcg_root, q, new_blkg);
if (IS_ERR(blkg)) if (IS_ERR(blkg))
goto err_unlock; goto err_unlock;
q->root_blkg = blkg; q->root_blkg = blkg;
spin_unlock_irq(&q->queue_lock); spin_unlock_irq(&q->queue_lock);
rcu_read_unlock();
if (preloaded) if (preloaded)
radix_tree_preload_end(); radix_tree_preload_end();
@ -1311,7 +1310,6 @@ int blkcg_init_queue(struct request_queue *q)
return ret; return ret;
err_unlock: err_unlock:
spin_unlock_irq(&q->queue_lock); spin_unlock_irq(&q->queue_lock);
rcu_read_unlock();
if (preloaded) if (preloaded)
radix_tree_preload_end(); radix_tree_preload_end();
return PTR_ERR(blkg); return PTR_ERR(blkg);