Re: [PATCH linux-2.6.18-xen] blktap: make max # of tap devices a module parameter

[Daniel Stodden <daniel.stodden@citrix.com>]

On Thu, 2011-02-24 at 11:40 -0500, Jan Beulich wrote:

>   /* 
>    * BLKTAP - immediately before the mmap area,
> @@ -511,26 +510,16 @@ blktap_ring_debug(struct blktap *tap, ch
>  int __init
>  blktap_ring_init(void)
>  {
> -	dev_t dev = 0;
>  	int err;
>  
> -	cdev_init(&blktap_ring_cdev, &blktap_ring_file_operations);
> -	blktap_ring_cdev.owner = THIS_MODULE;
> -
> -	err = alloc_chrdev_region(&dev, 0, MAX_BLKTAP_DEVICE, "blktap2");
> +	err = __register_chrdev(0, 0, MAX_BLKTAP_DEVICE, "blktap2",
> +				&blktap_ring_file_operations);
>  	if (err < 0) {
>  		BTERR("error registering ring devices: %d\n", err);
>  		return err;
>  	}
>  
> -	err = cdev_add(&blktap_ring_cdev, dev, MAX_BLKTAP_DEVICE);
> -	if (err) {
> -		BTERR("error adding ring device: %d\n", err);
> -		unregister_chrdev_region(dev, MAX_BLKTAP_DEVICE);
> -		return err;
> -	}
> -
> -	blktap_ring_major = MAJOR(dev);
> +	blktap_ring_major = err;
>  	BTINFO("blktap ring major: %d\n", blktap_ring_major);

While you are at it: Feel free to drop init message(s?), too. Blktap is
not boot critical, and there are plenty alternative places to check
presence.

Cheers,
Daniel