static void virtio_mem_deinit_hotplug()

in virtio_mem.c [2809:2872]

• 37 lines of code
• 4 McCabe index (conditional complexity)

static void virtio_mem_deinit_hotplug(struct virtio_mem *vm)
{
	unsigned long mb_id;
	int rc;

	/*
	 * Make sure the workqueue won't be triggered anymore and no memory
	 * blocks can be onlined/offlined until we're finished here.
	 */
	mutex_lock(&vm->hotplug_mutex);
	spin_lock_irq(&vm->removal_lock);
	vm->removing = true;
	spin_unlock_irq(&vm->removal_lock);
	mutex_unlock(&vm->hotplug_mutex);

	/* wait until the workqueue stopped */
	cancel_work_sync(&vm->wq);
	hrtimer_cancel(&vm->retry_timer);

	if (vm->in_sbm) {
		/*
		 * After we unregistered our callbacks, user space can online
		 * partially plugged offline blocks. Make sure to remove them.
		 */
		virtio_mem_sbm_for_each_mb(vm, mb_id,
					   VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL) {
			rc = virtio_mem_sbm_remove_mb(vm, mb_id);
			BUG_ON(rc);
			virtio_mem_sbm_set_mb_state(vm, mb_id,
						    VIRTIO_MEM_SBM_MB_UNUSED);
		}
		/*
		 * After we unregistered our callbacks, user space can no longer
		 * offline partially plugged online memory blocks. No need to
		 * worry about them.
		 */
	}

	/* unregister callbacks */
	unregister_virtio_mem_device(vm);
	unregister_memory_notifier(&vm->memory_notifier);

	/*
	 * There is no way we could reliably remove all memory we have added to
	 * the system. And there is no way to stop the driver/device from going
	 * away. Warn at least.
	 */
	if (virtio_mem_has_memory_added(vm)) {
		dev_warn(&vm->vdev->dev,
			 "device still has system memory added\n");
	} else {
		virtio_mem_delete_resource(vm);
		kfree_const(vm->resource_name);
		memory_group_unregister(vm->mgid);
	}

	/* remove all tracking data - no locking needed */
	if (vm->in_sbm) {
		vfree(vm->sbm.mb_states);
		vfree(vm->sbm.sb_states);
	} else {
		vfree(vm->bbm.bb_states);
	}
}