[IPV4]: Replace __in_dev_get with __in_dev_get_rcu/rtnl

The following patch renames __in_dev_get() to __in_dev_get_rtnl() and
introduces __in_dev_get_rcu() to cover the second case.

1) RCU with refcnt should use in_dev_get().
2) RCU without refcnt should use __in_dev_get_rcu().
3) All others must hold RTNL and use __in_dev_get_rtnl().

There is one exception in net/ipv4/route.c which is in fact a pre-existing
race condition.  I've marked it as such so that we remember to fix it.

This patch is based on suggestions and prior work by Suzanne Wood and
Paul McKenney.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 11 deletions

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index ba2895a..74f2207 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -351,7 +351,7 @@ static int inet_insert_ifa(struct in_ifaddr *ifa)
 
 static int inet_set_ifa(struct net_device *dev, struct in_ifaddr *ifa)
 {
-	struct in_device *in_dev = __in_dev_get(dev);
+	struct in_device *in_dev = __in_dev_get_rtnl(dev);
 
 	ASSERT_RTNL();
 
@@ -449,7 +449,7 @@ static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg
 		goto out;
 
 	rc = -ENOBUFS;
-	if ((in_dev = __in_dev_get(dev)) == NULL) {
+	if ((in_dev = __in_dev_get_rtnl(dev)) == NULL) {
 		in_dev = inetdev_init(dev);
 		if (!in_dev)
 			goto out;
@@ -584,7 +584,7 @@ int devinet_ioctl(unsigned int cmd, void __user *arg)
 	if (colon)
 		*colon = ':';
 
-	if ((in_dev = __in_dev_get(dev)) != NULL) {
+	if ((in_dev = __in_dev_get_rtnl(dev)) != NULL) {
 		if (tryaddrmatch) {
 			/* Matthias Andree */
 			/* compare label and address (4.4BSD style) */
@@ -748,7 +748,7 @@ rarok:
 
 static int inet_gifconf(struct net_device *dev, char __user *buf, int len)
 {
-	struct in_device *in_dev = __in_dev_get(dev);
+	struct in_device *in_dev = __in_dev_get_rtnl(dev);
 	struct in_ifaddr *ifa;
 	struct ifreq ifr;
 	int done = 0;
@@ -791,7 +791,7 @@ u32 inet_select_addr(const struct net_device *dev, u32 dst, int scope)
 	struct in_device *in_dev;
 
 	rcu_read_lock();
-	in_dev = __in_dev_get(dev);
+	in_dev = __in_dev_get_rcu(dev);
 	if (!in_dev)
 		goto no_in_dev;
 
@@ -818,7 +818,7 @@ no_in_dev:
 	read_lock(&dev_base_lock);
 	rcu_read_lock();
 	for (dev = dev_base; dev; dev = dev->next) {
-		if ((in_dev = __in_dev_get(dev)) == NULL)
+		if ((in_dev = __in_dev_get_rcu(dev)) == NULL)
 			continue;
 
 		for_primary_ifa(in_dev) {
@@ -887,7 +887,7 @@ u32 inet_confirm_addr(const struct net_device *dev, u32 dst, u32 local, int scop
 
 	if (dev) {
 		rcu_read_lock();
-		if ((in_dev = __in_dev_get(dev)))
+		if ((in_dev = __in_dev_get_rcu(dev)))
 			addr = confirm_addr_indev(in_dev, dst, local, scope);
 		rcu_read_unlock();
 
@@ -897,7 +897,7 @@ u32 inet_confirm_addr(const struct net_device *dev, u32 dst, u32 local, int scop
 	read_lock(&dev_base_lock);
 	rcu_read_lock();
 	for (dev = dev_base; dev; dev = dev->next) {
-		if ((in_dev = __in_dev_get(dev))) {
+		if ((in_dev = __in_dev_get_rcu(dev))) {
 			addr = confirm_addr_indev(in_dev, dst, local, scope);
 			if (addr)
 				break;
@@ -957,7 +957,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
 			 void *ptr)
 {
 	struct net_device *dev = ptr;
-	struct in_device *in_dev = __in_dev_get(dev);
+	struct in_device *in_dev = __in_dev_get_rtnl(dev);
 
 	ASSERT_RTNL();
 
@@ -1078,7 +1078,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 		if (idx > s_idx)
 			s_ip_idx = 0;
 		rcu_read_lock();
-		if ((in_dev = __in_dev_get(dev)) == NULL) {
+		if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
 			rcu_read_unlock();
 			continue;
 		}
@@ -1149,7 +1149,7 @@ void inet_forward_change(void)
 	for (dev = dev_base; dev; dev = dev->next) {
 		struct in_device *in_dev;
 		rcu_read_lock();
-		in_dev = __in_dev_get(dev);
+		in_dev = __in_dev_get_rcu(dev);
 		if (in_dev)
 			in_dev->cnf.forwarding = on;
 		rcu_read_unlock();