A later patch will call blk_freeze_queue_start() followed by blk_mq_unfreeze_queue() without waiting for q_usage_counter to drop to zero. Make sure that this doesn't cause a kernel warning to appear by switching from percpu_ref_reinit() to percpu_ref_resurrect(). The former namely requires that the refcount it operates on is zero.
Signed-off-by: Bart Van Assche <bvanass...@acm.org> Cc: Christoph Hellwig <h...@lst.de> Cc: Ming Lei <ming....@redhat.com> Cc: Jianchao Wang <jianchao.w.w...@oracle.com> Cc: Hannes Reinecke <h...@suse.com> Cc: Johannes Thumshirn <jthumsh...@suse.de> --- block/blk-mq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 85a1c1a59c72..96d501e8663c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -198,7 +198,7 @@ void blk_mq_unfreeze_queue(struct request_queue *q) freeze_depth = atomic_dec_return(&q->mq_freeze_depth); WARN_ON_ONCE(freeze_depth < 0); if (!freeze_depth) { - percpu_ref_reinit(&q->q_usage_counter); + percpu_ref_resurrect(&q->q_usage_counter); wake_up_all(&q->mq_freeze_wq); } } -- 2.19.0.444.g18242da7ef-goog