Re: [PATCH v5 1/2] blk-mq: add tagset quiesce interface

[Sagi Grimberg <sagi@xxxxxxxxxxx>]

> > +static void blk_mq_quiesce_blocking_queue_async_wait(struct request_queue *q)
> > +{
> > +	struct blk_mq_hw_ctx *hctx;
> > +	unsigned int i;
> > +
> > +	queue_for_each_hw_ctx(q, hctx, i) {
> > +		WARN_ON_ONCE(!(hctx->flags & BLK_MQ_F_BLOCKING));
> > +		if (!hctx->rcu_sync) {
> > +			synchronize_srcu(hctx->srcu);
> > +			continue;
> > +		}
> > +		wait_for_completion(&hctx->rcu_sync->completion);
> > +		destroy_rcu_head(&hctx->rcu_sync->head);
>
> Leaking rcu_sync, and not clearing it across quiesce contexts. Needs:
>
> 		kfree(hctx->rcu_sync);
> 		hctx->rcu_sync = NULL;

Good catch, will wait for some more review and submit a v6.