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

[Sagi Grimberg]

>> +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.