static ssize_t create_store()

in bus.c [330:378]

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

static ssize_t create_store(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t len)
{
	struct dax_region *dax_region = dev_get_drvdata(dev);
	unsigned long long avail;
	ssize_t rc;
	int val;

	if (is_static(dax_region))
		return -EINVAL;

	rc = kstrtoint(buf, 0, &val);
	if (rc)
		return rc;
	if (val != 1)
		return -EINVAL;

	device_lock(dev);
	avail = dax_region_avail_size(dax_region);
	if (avail == 0)
		rc = -ENOSPC;
	else {
		struct dev_dax_data data = {
			.dax_region = dax_region,
			.size = 0,
			.id = -1,
		};
		struct dev_dax *dev_dax = devm_create_dev_dax(&data);

		if (IS_ERR(dev_dax))
			rc = PTR_ERR(dev_dax);
		else {
			/*
			 * In support of crafting multiple new devices
			 * simultaneously multiple seeds can be created,
			 * but only the first one that has not been
			 * successfully bound is tracked as the region
			 * seed.
			 */
			if (!dax_region->seed)
				dax_region->seed = &dev_dax->dev;
			dax_region->youngest = &dev_dax->dev;
			rc = len;
		}
	}
	device_unlock(dev);

	return rc;
}