nvme-tcp: have queue prod/cons send list become a llist

	u32			pdu_sent;

	u16			ttag;

	struct list_head	entry;

	struct llist_node	lentry;

	__le32			ddgst;

	struct bio		*curr_bio;

	struct work_struct	io_work;

	int			io_cpu;

	spinlock_t		lock;

	struct mutex		send_mutex;

	struct llist_head	req_list;

	struct list_head	send_list;

	/* recv state */

	struct nvme_tcp_queue *queue = req->queue;

	bool empty;

	spin_lock(&queue->lock);

	empty = list_empty(&queue->send_list) && !queue->request;

	list_add_tail(&req->entry, &queue->send_list);

	spin_unlock(&queue->lock);

	empty = llist_add(&req->lentry, &queue->req_list) &&

		list_empty(&queue->send_list) && !queue->request;

	/*

	 * if we're the first on the send_list and we can try to send

	}

}

static void nvme_tcp_process_req_list(struct nvme_tcp_queue *queue)

{

	struct nvme_tcp_request *req;

	struct llist_node *node;

	for (node = llist_del_all(&queue->req_list); node; node = node->next) {

		req = llist_entry(node, struct nvme_tcp_request, lentry);

		list_add(&req->entry, &queue->send_list);

	}

}

static inline struct nvme_tcp_request *

nvme_tcp_fetch_request(struct nvme_tcp_queue *queue)

{

	struct nvme_tcp_request *req;

	spin_lock(&queue->lock);

	req = list_first_entry_or_null(&queue->send_list,

			struct nvme_tcp_request, entry);

	if (req)

		list_del(&req->entry);

	spin_unlock(&queue->lock);

	if (!req) {

		nvme_tcp_process_req_list(queue);

		req = list_first_entry_or_null(&queue->send_list,

				struct nvme_tcp_request, entry);

		if (unlikely(!req))

			return NULL;

	}

	list_del(&req->entry);

	return req;

}

	int ret, rcv_pdu_size;

	queue->ctrl = ctrl;

	init_llist_head(&queue->req_list);

	INIT_LIST_HEAD(&queue->send_list);

	spin_lock_init(&queue->lock);

	mutex_init(&queue->send_mutex);

	INIT_WORK(&queue->io_work, nvme_tcp_io_work);

	queue->queue_size = queue_size;