int __dax_driver_register()

in bus.c [1418:1457]

• 30 lines of code
• 6 McCabe index (conditional complexity)

int __dax_driver_register(struct dax_device_driver *dax_drv,
		struct module *module, const char *mod_name)
{
	struct device_driver *drv = &dax_drv->drv;
	int rc = 0;

	/*
	 * dax_bus_probe() calls dax_drv->probe() unconditionally.
	 * So better be safe than sorry and ensure it is provided.
	 */
	if (!dax_drv->probe)
		return -EINVAL;

	INIT_LIST_HEAD(&dax_drv->ids);
	drv->owner = module;
	drv->name = mod_name;
	drv->mod_name = mod_name;
	drv->bus = &dax_bus_type;

	/* there can only be one default driver */
	mutex_lock(&dax_bus_lock);
	match_always_count += dax_drv->match_always;
	if (match_always_count > 1) {
		match_always_count--;
		WARN_ON(1);
		rc = -EINVAL;
	}
	mutex_unlock(&dax_bus_lock);
	if (rc)
		return rc;

	rc = driver_register(drv);
	if (rc && dax_drv->match_always) {
		mutex_lock(&dax_bus_lock);
		match_always_count -= dax_drv->match_always;
		mutex_unlock(&dax_bus_lock);
	}

	return rc;
}