Re: Subject: [PATCH] Revert "[RTNETLINK]: Send a single notification on device state changes."

[Rafael J. Wysocki]

On Monday, 18 of February 2008, Jiri Kosina wrote:
> This reverts commit 45b503548210fe6f23e92b856421c2a3f05fd034.
> 
> It contains deadlock, and breaks userspace applications (wpa_supplicant,
> networkmanager). References:
> 
> http://bugzilla.kernel.org/show_bug.cgi?id=10002
> http://bugzilla.kernel.org/show_bug.cgi?id=10002

I think Andrew has already queued this one up.

Thanks,
Rafael


> ---
>  net/core/rtnetlink.c |   36 ++++++++++--------------------------
>  1 files changed, 10 insertions(+), 26 deletions(-)
> 
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index ecb02af..61ac8d0 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -504,7 +504,7 @@ int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
>  
>  EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);
>  
> -static int set_operstate(struct net_device *dev, unsigned char transition, bool send_notification)
> +static void set_operstate(struct net_device *dev, unsigned char transition)
>  {
>  	unsigned char operstate = dev->operstate;
>  
> @@ -527,12 +527,8 @@ static int set_operstate(struct net_device *dev, unsigned char transition, bool
>  		write_lock_bh(&dev_base_lock);
>  		dev->operstate = operstate;
>  		write_unlock_bh(&dev_base_lock);
> -
> -		if (send_notification)
> -			netdev_state_change(dev);
> -		return 1;
> -	} else
> -		return 0;
> +		netdev_state_change(dev);
> +	}
>  }
>  
>  static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
> @@ -826,7 +822,6 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
>  	if (tb[IFLA_BROADCAST]) {
>  		nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
>  		send_addr_notify = 1;
> -		modified = 1;
>  	}
>  
>  	if (ifm->ifi_flags || ifm->ifi_change) {
> @@ -839,23 +834,16 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
>  		dev_change_flags(dev, flags);
>  	}
>  
> -	if (tb[IFLA_TXQLEN]) {
> -		if (dev->tx_queue_len != nla_get_u32(tb[IFLA_TXQLEN])) {
> -			dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
> -			modified = 1;
> -		}
> -	}
> +	if (tb[IFLA_TXQLEN])
> +		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
>  
>  	if (tb[IFLA_OPERSTATE])
> -		modified |= set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]), false);
> +		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
>  
>  	if (tb[IFLA_LINKMODE]) {
> -		if (dev->link_mode != nla_get_u8(tb[IFLA_LINKMODE])) {
> -			write_lock_bh(&dev_base_lock);
> -			dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
> -			write_lock_bh(&dev_base_lock);
> -			modified = 1;
> -		}
> +		write_lock_bh(&dev_base_lock);
> +		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
> +		write_unlock_bh(&dev_base_lock);
>  	}
>  
>  	err = 0;
> @@ -869,10 +857,6 @@ errout:
>  
>  	if (send_addr_notify)
>  		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
> -
> -	if (modified)
> -		netdev_state_change(dev);
> -
>  	return err;
>  }
>  
> @@ -990,7 +974,7 @@ struct net_device *rtnl_create_link(struct net *net, char *ifname,
>  	if (tb[IFLA_TXQLEN])
>  		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
>  	if (tb[IFLA_OPERSTATE])
> -		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]), true);
> +		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
>  	if (tb[IFLA_LINKMODE])
>  		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
>  



-- 
"Premature optimization is the root of all evil." - Donald Knuth
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