This fixes the 4.14 backport commit 574eb136ec7f315c3ef2ca68fa9b3e16c56baa24 which was upstream commit f5bbbbe4d63577026f908a809f22f5fd5a90ea1f.
The upstream commit added a call to synchronize_rcu to _blk_mq_update_nr_hw_queues, just after freezing queues.
In the backport this landed just after unfreezeing queues.
This commit moves the call to its intended place.
Fixes: 574eb136ec7f ("blk-mq: sync the update nr_hw_queues with blk_mq_queue_tag_busy_iter") Signed-off-by: Giuliano Procida gprocida@google.com --- block/blk-mq.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c index 9d53f476c517..cf56bdad2e06 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2738,6 +2738,10 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
list_for_each_entry(q, &set->tag_list, tag_set_list) blk_mq_freeze_queue(q); + /* + * Sync with blk_mq_queue_tag_busy_iter. + */ + synchronize_rcu();
set->nr_hw_queues = nr_hw_queues; blk_mq_update_queue_map(set); @@ -2748,10 +2752,6 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
list_for_each_entry(q, &set->tag_list, tag_set_list) blk_mq_unfreeze_queue(q); - /* - * Sync with blk_mq_queue_tag_busy_iter. - */ - synchronize_rcu(); }
void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)