[PATCH 16/17] nvme: implement multipath access to nvme subsystems

[Guan Junxiong]

On 2017/10/23 22:51, Christoph Hellwig wrote:
> @@ -2427,20 +2681,46 @@ static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
>  	if (ret) {
>  		dev_err(ctrl->device,
>  			"duplicate IDs for nsid %d\n", nsid);
> -		goto out_free_head;
> +		goto out_release_instance;
>  	}
>  
> +	ret = -ENOMEM;
> +	q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE);
> +	if (!q)
> +		goto out_free_head;
> +	q->queuedata = head;
> +	blk_queue_make_request(q, nvme_ns_head_make_request);
> +	q->poll_fn = nvme_ns_head_poll;
> +	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
> +	/* set to a default value for 512 until disk is validated */
> +	blk_queue_logical_block_size(q, 512);
> +	nvme_set_queue_limits(ctrl, q);
> +
> +	head->disk = alloc_disk(0);
> +	if (!head->disk)
> +		goto out_cleanup_queue;
> +	head->disk->fops = &nvme_ns_head_ops;
> +	head->disk->private_data = head;
> +	head->disk->queue = q;
> +	head->disk->flags = GENHD_FL_EXT_DEVT;
> +	sprintf(head->disk->disk_name, "nvme%dn%d",
> +			ctrl->subsys->instance, nsid);

Is it okay to use head->instance instead of nsid for disk name nvme#n# ?
Becuase _nsid_ sets are not continuous sometimes, so disk name is ugly in that case.