Re: [Patch net-next v4] netpoll: fix some sparse warnings in various places

[Jiri Pirko <jiri@resnulli.us>]

Sat, Feb 16, 2013 at 09:37:53AM CET, amwang@redhat.com wrote:
>From: Cong Wang <amwang@redhat.com>
>
>This fixes sparse warnings like the one below:
>
>drivers/net/team/team.c:953:25: warning: incorrect type in return expression (different address spaces)
>drivers/net/team/team.c:953:25:    expected struct netpoll_info *
>drivers/net/team/team.c:953:25:    got struct netpoll_info [noderef] <asn:4>*npinfo
>
>Cc: Eric Dumazet <eric.dumazet@gmail.com>
>Cc: Jiri Pirko <jiri@resnulli.us>
>Cc: Vlad Yasevich <vyasevic@redhat.com>
>Cc: Stephen Hemminger <stephen@networkplumber.org>
>Cc: David S. Miller <davem@davemloft.net>
>Signed-off-by: Cong Wang <amwang@redhat.com>
>
>---
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 94c1534..71ad0f2 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -1302,7 +1302,7 @@ static int bond_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, g
> 
> static struct netpoll_info *bond_netpoll_info(struct bonding *bond)
> {
>-	return bond->dev->npinfo;
>+	return rcu_access_pointer(bond->dev->npinfo);
> }
> 
> #else
>diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
>index 05c5efe..03e5949 100644
>--- a/drivers/net/team/team.c
>+++ b/drivers/net/team/team.c
>@@ -950,7 +950,7 @@ static void team_port_disable_netpoll(struct team_port *port)
> 
> static struct netpoll_info *team_netpoll_info(struct team *team)
> {
>-	return team->dev->npinfo;
>+	return rcu_access_pointer(team->dev->npinfo);
> }
> 
> #else
>diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
>index 6d314c4..699d5c4 100644
>--- a/net/bridge/br_private.h
>+++ b/net/bridge/br_private.h
>@@ -330,7 +330,7 @@ extern netdev_tx_t br_dev_xmit(struct sk_buff *skb,
> #ifdef CONFIG_NET_POLL_CONTROLLER
> static inline struct netpoll_info *br_netpoll_info(struct net_bridge *br)
> {
>-	return br->dev->npinfo;
>+	return rcu_access_pointer(br->dev->npinfo);
> }
> 
> static inline void br_netpoll_send_skb(const struct net_bridge_port *p,


Hmm. I'm just wondering if there wouldn't be nicer for these functions to
return bool if you just want to know if npinfo is null or not. This
notation seems a bit confusing to me.