From: Daniel Wagner dwagner@suse.de
mainline inclusion from mainline-5.9-rc1 commit 08c875cbf481d74db82d6bba2fbcf580087dee24 category: bugfix bugzilla: 39772 CVE: NA
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tag_set_list is only accessed under the tag_set_lock lock. There is no need for using the _rcu list functions.
The _rcu list function were introduced to allow read access to the tag_set_list protected under RCU, see 705cda97ee3a ("blk-mq: Make it safe to use RCU to iterate over blk_mq_tag_set.tag_list") and 05b79413946d ("Revert "blk-mq: don't handle TAG_SHARED in restart""). Those changes got reverted later but the cleanup commit missed a couple of places to undo the changes.
Fixes: 97889f9ac24f ("blk-mq: remove synchronize_rcu() from blk_mq_del_queue_tag_set()" Signed-off-by: Daniel Wagner dwagner@suse.de Reviewed-by: Hannes Reinecke hare@suse.de Cc: Ming Lei ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Yufen Yu yuyufen@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- block/blk-mq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c index b5c2a4f65402..4965023121b5 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2521,7 +2521,7 @@ static void blk_mq_del_queue_tag_set(struct request_queue *q) struct blk_mq_tag_set *set = q->tag_set;
mutex_lock(&set->tag_list_lock); - list_del_rcu(&q->tag_set_list); + list_del(&q->tag_set_list); if (list_is_singular(&set->tag_list)) { /* just transitioned to unshared */ set->flags &= ~BLK_MQ_F_TAG_SHARED; @@ -2550,7 +2550,7 @@ static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, } if (set->flags & BLK_MQ_F_TAG_SHARED) queue_set_hctx_shared(q, true); - list_add_tail_rcu(&q->tag_set_list, &set->tag_list); + list_add_tail(&q->tag_set_list, &set->tag_list);
mutex_unlock(&set->tag_list_lock); }