[Bridge] [RFC PATCH] net: fold dev_disable_lro() into netdev_fix_features()

Michał Mirosław mirq-linux at rere.qmqm.pl
Sat May 7 04:48:02 PDT 2011


This moves checks that device is forwarding from bridge, IPv4 and IPv6
code into netdev_fix_features(). As a side effect, after device is no longer
forwarding it gets LRO back. This also means that user is not allowed to
enable LRO after device is put to forwarding mode.

This patch depends on removal of discrete offload setting ethtool ops.

Signed-off-by: Michał Mirosław <mirq-linux at rere.qmqm.pl>
---
 include/linux/netdevice.h |    1 -
 net/bridge/br_if.c        |    6 +++---
 net/core/dev.c            |   41 +++++++++++++++++++++--------------------
 net/ipv4/devinet.c        |   20 +++++++++-----------
 net/ipv6/addrconf.c       |    7 +++----
 5 files changed, 36 insertions(+), 39 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 7be3ca2..3a8c21d 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1627,7 +1627,6 @@ extern struct net_device	*__dev_get_by_name(struct net *net, const char *name);
 extern int		dev_alloc_name(struct net_device *dev, const char *name);
 extern int		dev_open(struct net_device *dev);
 extern int		dev_close(struct net_device *dev);
-extern void		dev_disable_lro(struct net_device *dev);
 extern int		dev_queue_xmit(struct sk_buff *skb);
 extern int		register_netdevice(struct net_device *dev);
 extern void		unregister_netdevice_queue(struct net_device *dev,
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 5dbdfdf..62aab1e 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -158,6 +158,8 @@ static void del_nbp(struct net_bridge_port *p)
 	br_netpoll_disable(p);
 
 	call_rcu(&p->rcu, destroy_nbp_rcu);
+
+	netdev_update_features(dev);
 }
 
 /* called with RTNL */
@@ -368,11 +370,9 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
 
 	dev->priv_flags |= IFF_BRIDGE_PORT;
 
-	dev_disable_lro(dev);
-
 	list_add_rcu(&p->list, &br->port_list);
 
-	netdev_update_features(br->dev);
+	netdev_update_features(dev);
 
 	spin_lock_bh(&br->lock);
 	changed_addr = br_stp_recalculate_bridge_id(br);
diff --git a/net/core/dev.c b/net/core/dev.c
index 7193499..3d646c9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -132,6 +132,7 @@
 #include <trace/events/skb.h>
 #include <linux/pci.h>
 #include <linux/inetdevice.h>
+#include <net/addrconf.h>
 #include <linux/cpu_rmap.h>
 
 #include "net-sysfs.h"
@@ -1294,26 +1295,6 @@ int dev_close(struct net_device *dev)
 EXPORT_SYMBOL(dev_close);
 
 
-/**
- *	dev_disable_lro - disable Large Receive Offload on a device
- *	@dev: device
- *
- *	Disable Large Receive Offload (LRO) on a net device.  Must be
- *	called under RTNL.  This is needed if received packets may be
- *	forwarded to another interface.
- */
-void dev_disable_lro(struct net_device *dev)
-{
-	dev->wanted_features &= ~NETIF_F_LRO;
-	netdev_update_features(dev);
-
-	if (unlikely(dev->features & NETIF_F_LRO))
-		netdev_WARN(dev, "failed to disable LRO!\n");
-
-}
-EXPORT_SYMBOL(dev_disable_lro);
-
-
 static int dev_boot_phase = 1;
 
 /**
@@ -5239,6 +5220,26 @@ u32 netdev_fix_features(struct net_device *dev, u32 features)
 		}
 	}
 
+	if (features & NETIF_F_LRO) {
+		struct in_device *in4_dev;
+		struct inet6_dev *in6_dev;
+
+		/* disable LRO for bridge ports */
+		if (dev->priv_flags & IFF_BRIDGE_PORT) {
+			netdev_info(dev, "Disabling LRO for bridge port.\n");
+			features &= NETIF_F_LRO;
+		} else /* ... or when forwarding IPv4 */
+		if (((in4_dev = __in_dev_get_rtnl(dev))) &&
+		    IN_DEV_CONF_GET(in4_dev, FORWARDING)) {
+			netdev_info(dev, "Disabling LRO for IPv4 router port.\n");
+			features &= NETIF_F_LRO;
+		} else /* ... or when forwarding IPv6 */
+		if (((in6_dev = __in6_dev_get(dev))) && in6_dev->cnf.forwarding) {
+			netdev_info(dev, "Disabling LRO for IPv6 router port.\n");
+			features &= NETIF_F_LRO;
+		}
+	}
+
 	return features;
 }
 EXPORT_SYMBOL(netdev_fix_features);
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index cd9ca08..e9c0557 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -245,8 +245,6 @@ static struct in_device *inetdev_init(struct net_device *dev)
 	in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl);
 	if (!in_dev->arp_parms)
 		goto out_kfree;
-	if (IPV4_DEVCONF(in_dev->cnf, FORWARDING))
-		dev_disable_lro(dev);
 	/* Reference in_dev->dev */
 	dev_hold(dev);
 	/* Account for reference dev->ip_ptr (below) */
@@ -259,6 +257,8 @@ static struct in_device *inetdev_init(struct net_device *dev)
 
 	/* we can receive as soon as ip_ptr is set -- do this last */
 	rcu_assign_pointer(dev->ip_ptr, in_dev);
+
+	netdev_update_features(dev);
 out:
 	return in_dev;
 out_kfree:
@@ -1475,14 +1475,12 @@ static void inet_forward_change(struct net *net)
 	IPV4_DEVCONF_DFLT(net, FORWARDING) = on;
 
 	for_each_netdev(net, dev) {
-		struct in_device *in_dev;
-		if (on)
-			dev_disable_lro(dev);
-		rcu_read_lock();
-		in_dev = __in_dev_get_rcu(dev);
-		if (in_dev)
+		struct in_device *in_dev = __in_dev_get_rtnl(dev);
+
+		if (in_dev) {
 			IN_DEV_CONF_SET(in_dev, FORWARDING, on);
-		rcu_read_unlock();
+			netdev_update_features(in_dev->dev);
+		}
 	}
 }
 
@@ -1527,11 +1525,11 @@ static int devinet_sysctl_forward(ctl_table *ctl, int write,
 			}
 			if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
 				inet_forward_change(net);
-			} else if (*valp) {
+			} else {
 				struct ipv4_devconf *cnf = ctl->extra1;
 				struct in_device *idev =
 					container_of(cnf, struct in_device, cnf);
-				dev_disable_lro(idev->dev);
+				netdev_update_features(idev->dev);
 			}
 			rtnl_unlock();
 			rt_cache_flush(net, 0);
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f2f9b2e..d1344ac 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -370,8 +370,6 @@ static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
 		kfree(ndev);
 		return NULL;
 	}
-	if (ndev->cnf.forwarding)
-		dev_disable_lro(dev);
 	/* We refer to the device */
 	dev_hold(dev);
 
@@ -435,6 +433,7 @@ static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
 	addrconf_sysctl_register(ndev);
 	/* protected by rtnl_lock */
 	rcu_assign_pointer(dev->ip6_ptr, ndev);
+	netdev_update_features(dev);
 
 	/* Join all-node multicast group */
 	ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
@@ -469,8 +468,6 @@ static void dev_forward_change(struct inet6_dev *idev)
 	if (!idev)
 		return;
 	dev = idev->dev;
-	if (idev->cnf.forwarding)
-		dev_disable_lro(dev);
 	if (dev && (dev->flags & IFF_MULTICAST)) {
 		if (idev->cnf.forwarding)
 			ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
@@ -486,6 +483,8 @@ static void dev_forward_change(struct inet6_dev *idev)
 		else
 			addrconf_leave_anycast(ifa);
 	}
+
+	netdev_update_features(dev);
 }
 
 
-- 
1.7.2.5



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