+ if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
+ vdev->config->get(vdev,
+ offsetof(struct virtio_9p_config, tag_len),
+ &tag_len, sizeof(tag_len));
+ } else {
+ err = -EINVAL;
+ goto out_free_vq;
+ }
+ tag = kmalloc(tag_len, GFP_KERNEL);
+ if (!tag) {
+ err = -ENOMEM;
+ goto out_free_vq;
+ }
+ vdev->config->get(vdev, offsetof(struct virtio_9p_config, tag),
+ tag, tag_len);
+ chan->tag = tag;
+ chan->tag_len = tag_len;
+ err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
+ if (err) {
+ kfree(tag);
+ goto out_free_vq;
+ }
+ mutex_lock(&virtio_9p_lock);
+ list_add_tail(&chan->chan_list, &virtio_chan_list);
+ mutex_unlock(&virtio_9p_lock);