From mboxrd@z Thu Jan  1 00:00:00 1970
From: Benjamin Poirier <benjamin.poirier@gmail.com>
Subject: Re: [patch net-next-2.6] net: introduce ethernet teaming device
Date: Wed, 19 Oct 2011 13:26:24 -0400
Message-ID: <20111019172624.GB21324@synalogic.ca>
References: <1317737703-19457-1-git-send-email-jpirko@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: netdev@vger.kernel.org, davem@davemloft.net,
	eric.dumazet@gmail.com, bhutchings@solarflare.com,
	shemminger@vyatta.com, fubar@us.ibm.com, andy@greyhouse.net,
	tgraf@infradead.org, ebiederm@xmission.com, mirqus@gmail.com,
	kaber@trash.net, greearb@candelatech.com, jesse@nicira.com
To: Jiri Pirko <jpirko@redhat.com>
Return-path: <netdev-owner@vger.kernel.org>
Received: from mail-vx0-f174.google.com ([209.85.220.174]:51690 "EHLO
	mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1755355Ab1JSR0b (ORCPT
	<rfc822;netdev@vger.kernel.org>); Wed, 19 Oct 2011 13:26:31 -0400
Received: by vcge1 with SMTP id e1so1719562vcg.19
        for <netdev@vger.kernel.org>; Wed, 19 Oct 2011 10:26:31 -0700 (PDT)
Content-Disposition: inline
In-Reply-To: <1317737703-19457-1-git-send-email-jpirko@redhat.com>
Sender: netdev-owner@vger.kernel.org
List-ID: <netdev.vger.kernel.org>

Hi Jiri, just a few late comments:

On 11/10/04 16:15, Jiri Pirko wrote:
> This patch introduces new network device called team. It supposes to be
> very fast, simple, userspace-driven alternative to existing bonding
> driver.
> 
> Userspace library called libteam with couple of demo apps is available
> here:
> https://github.com/jpirko/libteam
> Note it's still in its dipers atm.
> 
> team<->libteam use generic netlink for communication. That and rtnl
> suppose to be the only way to configure team device, no sysfs etc.
> 
> In near future python binding for libteam will be introduced. Also
> daemon providing arpmon/miimon active-backup functionality will
> be introduced. All what's necessary is already implemented in kernel team
> driver.
> 
> Signed-off-by: Jiri Pirko <jpirko@redhat.com>

[...]

> +/******************************
> + * Round-robin mode definition
> + ******************************/
> +
> +static struct team_port *__get_first_port_up(struct team *team,
> +					     struct team_port *port)

This is more like __get_"next"_port_up() no?

> +{
> +	struct team_port *cur;
> +
> +	if (port->linkup)
> +		return port;
> +	cur = port;
> +	list_for_each_entry_continue_rcu(cur, &team->port_list, list)
> +		if (cur->linkup)
> +			return cur;
> +	list_for_each_entry_rcu(cur, &team->port_list, list) {
> +		if (cur == port)
> +			break;
> +		if (cur->linkup)
> +			return cur;
> +	}
> +	return NULL;
> +}
> +

[...]

> +
> +
> +/****************
> + * Mode handling
> + ****************/
> +
> +static const struct team_mode *team_modes[] = {
> +	&rr_mode,
> +	&ab_mode,
> +};
> +
> +static const int team_mode_count = ARRAY_SIZE(team_modes);
> +
> +static int team_find_mode(const char *kind)
> +{
> +	int i;
> +
> +	for (i = 0; i < team_mode_count; i++) {
> +		const struct team_mode *mode = team_modes[i];
> +
> +		if (strcmp(mode->kind, kind) == 0)
> +			return i;
> +	}
> +	return -ENOENT;
> +}
> +
> +/*
> + * We can benefit from the fact that it's ensured no port is present
> + * at the time of mode change.
> + */
> +static void __team_change_mode(struct team *team, const int mode_index)
> +{
> +	const struct team_mode *mode = team_modes[mode_index];

team_uninit() calls __team_change_mode(team, -1) which will therefore
dereference team_modes[-1]. Is this always safe?

-Ben