up_write(&device->group->group_rwsem);
 }
 
+static void vfio_device_container_register(struct vfio_device *device)
+{
+       struct vfio_iommu_driver *iommu_driver =
+               device->group->container->iommu_driver;
+
+       if (iommu_driver && iommu_driver->ops->register_device)
+               iommu_driver->ops->register_device(
+                       device->group->container->iommu_data, device);
+}
+
+static void vfio_device_container_unregister(struct vfio_device *device)
+{
+       struct vfio_iommu_driver *iommu_driver =
+               device->group->container->iommu_driver;
+
+       if (iommu_driver && iommu_driver->ops->unregister_device)
+               iommu_driver->ops->unregister_device(
+                       device->group->container->iommu_data, device);
+}
+
 static struct file *vfio_device_open(struct vfio_device *device)
 {
-       struct vfio_iommu_driver *iommu_driver;
        struct file *filep;
        int ret;
 
                        if (ret)
                                goto err_undo_count;
                }
-
-               iommu_driver = device->group->container->iommu_driver;
-               if (iommu_driver && iommu_driver->ops->register_device)
-                       iommu_driver->ops->register_device(
-                               device->group->container->iommu_data, device);
-
+               vfio_device_container_register(device);
                up_read(&device->group->group_rwsem);
        }
        mutex_unlock(&device->dev_set->lock);
        if (device->open_count == 1 && device->ops->close_device) {
                device->ops->close_device(device);
 
-               iommu_driver = device->group->container->iommu_driver;
-               if (iommu_driver && iommu_driver->ops->unregister_device)
-                       iommu_driver->ops->unregister_device(
-                               device->group->container->iommu_data, device);
+               vfio_device_container_unregister(device);
        }
 err_undo_count:
        up_read(&device->group->group_rwsem);
 static int vfio_device_fops_release(struct inode *inode, struct file *filep)
 {
        struct vfio_device *device = filep->private_data;
-       struct vfio_iommu_driver *iommu_driver;
 
        mutex_lock(&device->dev_set->lock);
        vfio_assert_device_open(device);
        if (device->open_count == 1 && device->ops->close_device)
                device->ops->close_device(device);
 
-       iommu_driver = device->group->container->iommu_driver;
-       if (iommu_driver && iommu_driver->ops->unregister_device)
-               iommu_driver->ops->unregister_device(
-                       device->group->container->iommu_data, device);
+       vfio_device_container_unregister(device);
        up_read(&device->group->group_rwsem);
        device->open_count--;
        if (device->open_count == 0)