Re: [PATCH 4/4] nvme: wire up async polling for io passthrough commands

[Jens Axboe <axboe@kernel.dk>]

On 8/5/22 9:42 AM, Kanchan Joshi wrote:
> @@ -685,6 +721,29 @@ int nvme_ns_head_chr_uring_cmd(struct io_uring_cmd *ioucmd,
>  	srcu_read_unlock(&head->srcu, srcu_idx);
>  	return ret;
>  }
> +
> +int nvme_ns_head_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd)
> +{
> +	struct cdev *cdev = file_inode(ioucmd->file)->i_cdev;
> +	struct nvme_ns_head *head = container_of(cdev, struct nvme_ns_head, cdev);
> +	int srcu_idx = srcu_read_lock(&head->srcu);
> +	struct nvme_ns *ns = nvme_find_path(head);
> +	struct bio *bio;
> +	int ret = 0;
> +	struct request_queue *q;
> +
> +	if (ns) {
> +		rcu_read_lock();
> +		bio = READ_ONCE(ioucmd->private);
> +		q = ns->queue;
> +		if (test_bit(QUEUE_FLAG_POLL, &q->queue_flags) && bio
> +				&& bio->bi_bdev)
> +			ret = bio_poll(bio, 0, 0);
> +		rcu_read_unlock();
> +	}
> +	srcu_read_unlock(&head->srcu, srcu_idx);
> +	return ret;
> +}
>  #endif /* CONFIG_NVME_MULTIPATH */

Looks like that READ_ONCE() should be:

	bio = READ_ONCE(ioucmd->cookie);

?

-- 
Jens Axboe