[PATCH v2 net-next 5/7] ip_tunnel: Unify error paths in ip_tunnel_newlink() and ip_tunnel_changelink().

[Kuniyuki Iwashima <kuniyu@google.com>]

The next patch will introduce per-netns mutex and acquire it
in ip_tunnel_newlink() and ip_tunnel_changelink().

To make the diff cleaner, let's unify the error paths.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 net/ipv4/ip_tunnel.c | 37 ++++++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 5833f93c1964..3ba03c2b3b90 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -1181,21 +1181,23 @@ int ip_tunnel_newlink(struct net *net, struct net_device *dev,
 		      struct nlattr *tb[], struct ip_tunnel_parm_kern *p,
 		      __u32 fwmark)
 {
-	struct ip_tunnel *nt;
 	struct ip_tunnel_net *itn;
+	struct ip_tunnel *nt;
+	int err = 0;
 	int mtu;
-	int err;
 
 	nt = netdev_priv(dev);
 	itn = net_generic(net, nt->ip_tnl_net_id);
 
 	if (nt->collect_md) {
 		if (rtnl_dereference(itn->collect_md_tun))
-			return -EEXIST;
+			err = -EEXIST;
 	} else {
 		if (ip_tunnel_find(itn, p, dev->type))
-			return -EEXIST;
+			err = -EEXIST;
 	}
+	if (err)
+		goto out;
 
 	nt->net = net;
 	nt->parms = *p;
@@ -1222,22 +1224,26 @@ int ip_tunnel_newlink(struct net *net, struct net_device *dev,
 		goto err_dev_set_mtu;
 
 	ip_tunnel_add(itn, nt);
-	return 0;
+out:
+	return err;
 
 err_dev_set_mtu:
 	unregister_netdevice(dev);
 err_register_netdevice:
-	return err;
+	goto out;
 }
 EXPORT_SYMBOL_GPL(ip_tunnel_newlink);
 
 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 			 struct ip_tunnel_parm_kern *p, __u32 fwmark)
 {
-	struct ip_tunnel *t;
 	struct ip_tunnel *tunnel = netdev_priv(dev);
 	struct net *net = tunnel->net;
-	struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id);
+	struct ip_tunnel_net *itn;
+	struct ip_tunnel *t;
+	int err = 0;
+
+	itn = net_generic(net, tunnel->ip_tnl_net_id);
 
 	if (dev == itn->fb_tunnel_dev)
 		return -EINVAL;
@@ -1245,8 +1251,10 @@ int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 	t = ip_tunnel_find(itn, p, dev->type);
 
 	if (t) {
-		if (t->dev != dev)
-			return -EEXIST;
+		if (t->dev != dev) {
+			err = -EEXIST;
+			goto out;
+		}
 	} else {
 		t = tunnel;
 
@@ -1259,13 +1267,16 @@ int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 				nflags = IFF_POINTOPOINT;
 
 			if ((dev->flags ^ nflags) &
-			    (IFF_POINTOPOINT | IFF_BROADCAST))
-				return -EINVAL;
+			    (IFF_POINTOPOINT | IFF_BROADCAST)) {
+				err = -EINVAL;
+				goto out;
+			}
 		}
 	}
 
 	ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU], fwmark);
-	return 0;
+out:
+	return err;
 }
 EXPORT_SYMBOL_GPL(ip_tunnel_changelink);
 
-- 
2.55.0.1003.g10538fe699-goog