bridge: make bridge support netpoll

Based on the previous patch, make bridge support netpoll by:

1) implement the 2 methods to support netpoll for bridge;

2) modify netpoll during forwarding packets via bridge;

3) disable netpoll support of bridge when a netpoll-unabled device
   is added to bridge;

4) enable netpoll support when all underlying devices support netpoll.

Cc: David Miller <davem@davemloft.net>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 1 deletions

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 396f077216a3..92ad9feb199d 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
+#include <linux/netpoll.h>
 #include <linux/skbuff.h>
 #include <linux/if_vlan.h>
 #include <linux/netfilter_bridge.h>
@@ -50,7 +51,13 @@ int br_dev_queue_push_xmit(struct sk_buff *skb)
                 else {
                         skb_push(skb, ETH_HLEN);
 
-                        dev_queue_xmit(skb);
+#ifdef CONFIG_NET_POLL_CONTROLLER
+                        if (unlikely(skb->dev->priv_flags & IFF_IN_NETPOLL)) {
+                                netpoll_send_skb(skb->dev->npinfo->netpoll, skb);
+                                skb->dev->priv_flags &= ~IFF_IN_NETPOLL;
+                        } else
+#endif
+                                dev_queue_xmit(skb);
                 }
         }
 
@@ -66,9 +73,23 @@ int br_forward_finish(struct sk_buff *skb)
 
 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
 {
+#ifdef CONFIG_NET_POLL_CONTROLLER
+        struct net_bridge *br = to->br;
+        if (unlikely(br->dev->priv_flags & IFF_IN_NETPOLL)) {
+                struct netpoll *np;
+                to->dev->npinfo = skb->dev->npinfo;
+                np = skb->dev->npinfo->netpoll;
+                np->real_dev = np->dev = to->dev;
+                to->dev->priv_flags |= IFF_IN_NETPOLL;
+        }
+#endif
         skb->dev = to->dev;
         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
                         br_forward_finish);
+#ifdef CONFIG_NET_POLL_CONTROLLER
+        if (skb->dev->npinfo)
+                skb->dev->npinfo->netpoll->dev = br->dev;
+#endif
 }
 
 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)