[Bridge] [PATCH] 2.4.27-rc4 bridge fix

[Bridge] [PATCH] 2.4.27-rc4 bridge fix

[Stephen Hemminger]

The problem was that the br_add_bridge ended up calling register_netdev
that did a rtnl_lock.  This fixes that, and gets rid of the bridge_list,
there is no need to keep a separate device list of just bridges.  By not
having multiple lists, races are avoided. 

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>


diff -urNp -X dontdiff linux-2.4/net/bridge/br_if.c bridge-2.4/net/bridge/br_if.c
--- linux-2.4/net/bridge/br_if.c	2004-08-02 10:22:45.331010728 -0700
+++ bridge-2.4/net/bridge/br_if.c	2004-08-02 12:57:58.405208248 -0700
@@ -23,8 +23,6 @@
 #include <asm/uaccess.h>
 #include "br_private.h"
 
-static struct net_bridge *bridge_list;
-
 static int br_initial_port_cost(struct net_device *dev)
 {
 	if (!strncmp(dev->name, "lec", 3))
@@ -70,22 +68,6 @@ static int __br_del_if(struct net_bridge
 	return 0;
 }
 
-static struct net_bridge **__find_br(char *name)
-{
-	struct net_bridge **b;
-	struct net_bridge *br;
-
-	b = &bridge_list;
-	while ((br = *b) != NULL) {
-		if (!strncmp(br->dev.name, name, IFNAMSIZ))
-			return b;
-
-		b = &(br->next);
-	}
-
-	return NULL;
-}
-
 static void del_ifs(struct net_bridge *br)
 {
 	br_write_lock_bh(BR_NETPROTO_LOCK);
@@ -178,42 +160,48 @@ static struct net_bridge_port *new_nbp(s
 int br_add_bridge(char *name)
 {
 	struct net_bridge *br;
+	struct net_device *dev;
+	int err;
 
 	if ((br = new_nb(name)) == NULL)
 		return -ENOMEM;
 
-	if (__dev_get_by_name(name) != NULL) {
-		kfree(br);
-		return -EEXIST;
+	dev = &br->dev;
+	if (strchr(dev->name, '%')) {
+		err = dev_alloc_name(dev, dev->name);
+		if (err < 0)
+			goto  out;
 	}
 
-	br->next = bridge_list;
-	bridge_list = br;
+	err = register_netdevice(dev);
+	if (err == 0)
+		br_inc_use_count();
 
-	br_inc_use_count();
-	register_netdev(&br->dev);
-
-	return 0;
+ out:
+	return err;
 }
 
 int br_del_bridge(char *name)
 {
-	struct net_bridge **b;
+	struct net_device *dev;
 	struct net_bridge *br;
 
-	if ((b = __find_br(name)) == NULL)
+	dev = __dev_get_by_name(name);
+	if (!dev)
 		return -ENXIO;
 
-	br = *b;
+	if (dev->hard_start_xmit != br_dev_xmit)
+		return -EPERM;
 
-	if (br->dev.flags & IFF_UP)
+	if (dev->flags & IFF_UP)
 		return -EBUSY;
 
-	del_ifs(br);
+	br = dev->priv;
+	BUG_ON(&br->dev != dev);
 
-	*b = br->next;
+	del_ifs(br);
 
-	unregister_netdev(&br->dev);
+	unregister_netdevice(dev);
 	kfree(br);
 	br_dec_use_count();
 
@@ -271,16 +259,12 @@ int br_del_if(struct net_bridge *br, str
 
 int br_get_bridge_ifindices(int *indices, int num)
 {
-	struct net_bridge *br;
-	int i;
-
-	br = bridge_list;
-	for (i=0;i<num;i++) {
-		if (br == NULL)
-			break;
+	struct net_device *dev;
+	int i = 0;
 
-		indices[i] = br->dev.ifindex;
-		br = br->next;
+	for (dev = dev_base; i < num && dev != NULL; dev = dev->next) {
+		if (dev->hard_start_xmit == br_dev_xmit)
+			indices[i++] = dev->ifindex;
 	}
 
 	return i;
diff -urNp -X dontdiff linux-2.4/net/bridge/br_ioctl.c bridge-2.4/net/bridge/br_ioctl.c
--- linux-2.4/net/bridge/br_ioctl.c	2004-08-02 10:22:45.332010576 -0700
+++ bridge-2.4/net/bridge/br_ioctl.c	2004-08-02 12:57:58.407207944 -0700
@@ -250,14 +250,9 @@ int br_ioctl_deviceless_stub(unsigned lo
 
 int br_ioctl(struct net_bridge *br, unsigned int cmd, unsigned long arg0, unsigned long arg1, unsigned long arg2)
 {
-	int err;
-
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 
 	ASSERT_RTNL();
-	err = br_ioctl_deviceless(cmd, arg0, arg1);
-	if (err == -EOPNOTSUPP)
-		err = br_ioctl_device(br, cmd, arg0, arg1, arg2);
-	return err;
+	return br_ioctl_device(br, cmd, arg0, arg1, arg2);
 }
diff -urNp -X dontdiff linux-2.4/net/bridge/br_private.h bridge-2.4/net/bridge/br_private.h
--- linux-2.4/net/bridge/br_private.h	2004-08-02 10:22:45.333010424 -0700
+++ bridge-2.4/net/bridge/br_private.h	2004-08-02 10:39:09.582381776 -0700
@@ -79,7 +79,6 @@ struct net_bridge_port
 
 struct net_bridge
 {
-	struct net_bridge		*next;
 	rwlock_t			lock;
 	struct net_bridge_port		*port_list;
 	struct net_device		dev;

[Bridge] Re: [PATCH] 2.4.27-rc4 bridge fix

[David S. Miller]

On Mon, 2 Aug 2004 13:08:40 -0700
Stephen Hemminger <shemminger@osdl.org> wrote:

> The problem was that the br_add_bridge ended up calling register_netdev
> that did a rtnl_lock.  This fixes that, and gets rid of the bridge_list,
> there is no need to keep a separate device list of just bridges.  By not
> having multiple lists, races are avoided. 

Marcelo, please apply this.

Thanks.

[Bridge] Re: [PATCH] 2.4.27-rc4 bridge fix

[Santiago Garcia Mantinan]

> The problem was that the br_add_bridge ended up calling register_netdev
> that did a rtnl_lock.  This fixes that, and gets rid of the bridge_list,
> there is no need to keep a separate device list of just bridges.  By not
> having multiple lists, races are avoided. 

Ok, this time it looks ok, it seems to fix the problem I had reported for
rc3 and also the one itroduced by the patch that was applied on rc4 to fix
it, so far everything seems to work ok now.

Thanks for fixing this.

Regards...
-- 
Manty/BestiaTester -> http://manty.net