Re: [PATCH][ATM] add reference counting to atm_dev

[Greg KH]

On Wed, May 14, 2003 at 04:20:09PM -0400, chas williams wrote:
> this patch adds a reference count to atm_dev, and a lock to
> protect the members of struct atm_dev.  atm_dev_lock is now
> used to protect the atm_dev linked list.  atm_find_dev was
> renamed to atm_dev_lookup.  atm_dev_hold and atm_dev_release
> were added to manipulate atm_dev's reference count.  this
> fixes atm_ioctl()'s troublesome 'global' spinlock.  also,
> got rid of the nodev list of 'unlinked' vccs.
> 
> 
> --- linux-2.5.68/include/linux/atmdev.h.004	Fri May  9 08:30:20 2003
> +++ linux-2.5.68/include/linux/atmdev.h	Wed May 14 12:40:39 2003
> @@ -331,6 +331,8 @@
>  	struct k_atm_dev_stats stats;	/* statistics */
>  	char		signal;		/* signal status (ATM_PHY_SIG_*) */
>  	int		link_rate;	/* link rate (default: OC3) */
> +	atomic_t	refcnt;		/* reference count */

Any reason to not just use a struct device here?  This is a device,
right?  Or at the very least, a kobject would be acceptable.

Please don't roll your own reference counting code, when we've already
gotten a in-kernel version that has been debugged quite well.

Is this going to help us be able to get rid of the MOD_* calls in ATM
drivers soon?

thanks,

greg k-h