+static void nbd_handle_req(struct nbd_device *lo, struct request *req)
+{
+ if (!blk_fs_request(req))
+ goto error_out;
+
+ nbd_cmd(req) = NBD_CMD_READ;
+ if (rq_data_dir(req) == WRITE) {
+ nbd_cmd(req) = NBD_CMD_WRITE;
+ if (lo->flags & NBD_READ_ONLY) {
+ printk(KERN_ERR "%s: Write on read-only\n",
+ lo->disk->disk_name);
+ goto error_out;
+ }
+ }
+
+ req->errors = 0;
+
+ mutex_lock(&lo->tx_lock);
+ if (unlikely(!lo->sock)) {
+ mutex_unlock(&lo->tx_lock);
+ printk(KERN_ERR "%s: Attempted send on closed socket\n",
+ lo->disk->disk_name);
+ req->errors++;
+ nbd_end_request(req);
+ return;
+ }
+
+ lo->active_req = req;
+
+ if (nbd_send_req(lo, req) != 0) {
+ printk(KERN_ERR "%s: Request send failed\n",
+ lo->disk->disk_name);
+ req->errors++;
+ nbd_end_request(req);
+ } else {
+ spin_lock(&lo->queue_lock);
+ list_add(&req->queuelist, &lo->queue_head);
+ spin_unlock(&lo->queue_lock);
+ }
+
+ lo->active_req = NULL;
+ mutex_unlock(&lo->tx_lock);
+ wake_up_all(&lo->active_wq);
+
+ return;
+
+error_out:
+ req->errors++;
+ nbd_end_request(req);
+}
+
+static int nbd_thread(void *data)
+{
+ struct nbd_device *lo = data;
+ struct request *req;
+
+ set_user_nice(current, -20);
+ while (!kthread_should_stop() || !list_empty(&lo->waiting_queue)) {
+ /* wait for something to do */
+ wait_event_interruptible(lo->waiting_wq,
+ kthread_should_stop() ||
+ !list_empty(&lo->waiting_queue));
+
+ /* extract request */
+ if (list_empty(&lo->waiting_queue))
+ continue;
+
+ spin_lock_irq(&lo->queue_lock);
+ req = list_entry(lo->waiting_queue.next, struct request,
+ queuelist);
+ list_del_init(&req->queuelist);
+ spin_unlock_irq(&lo->queue_lock);
+
+ /* handle request */
+ nbd_handle_req(lo, req);
+ }
+ return 0;
+}
+