int xenbus_dev_probe()

in xenbus/xenbus_probe.c [267:325]

• 50 lines of code
• 8 McCabe index (conditional complexity)

int xenbus_dev_probe(struct device *_dev)
{
	struct xenbus_device *dev = to_xenbus_device(_dev);
	struct xenbus_driver *drv = to_xenbus_driver(_dev->driver);
	const struct xenbus_device_id *id;
	int err;

	DPRINTK("%s", dev->nodename);

	if (!drv->probe) {
		err = -ENODEV;
		goto fail;
	}

	id = match_device(drv->ids, dev);
	if (!id) {
		err = -ENODEV;
		goto fail;
	}

	err = talk_to_otherend(dev);
	if (err) {
		dev_warn(&dev->dev, "talk_to_otherend on %s failed.\n",
			 dev->nodename);
		return err;
	}

	if (!try_module_get(drv->driver.owner)) {
		dev_warn(&dev->dev, "failed to acquire module reference on '%s'\n",
			 drv->driver.name);
		err = -ESRCH;
		goto fail;
	}

	down(&dev->reclaim_sem);
	err = drv->probe(dev, id);
	up(&dev->reclaim_sem);
	if (err)
		goto fail_put;

	err = watch_otherend(dev);
	if (err) {
		dev_warn(&dev->dev, "watch_otherend on %s failed.\n",
		       dev->nodename);
		return err;
	}

	dev->spurious_threshold = 1;
	if (sysfs_create_group(&dev->dev.kobj, &xenbus_group))
		dev_warn(&dev->dev, "sysfs_create_group on %s failed.\n",
			 dev->nodename);

	return 0;
fail_put:
	module_put(drv->driver.owner);
fail:
	xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename);
	return err;
}