From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 3 Jun 2010 04:13:21 +0000 (+0000)
Subject: ipv4: RCU changes in __mkroute_input()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4736022844fe694c4ee971fa2b6c1cb38dadbc78;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

ipv4: RCU changes in __mkroute_input()

Avoid two atomic ops on output device refcount

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 1cfe0d199e7c..7b8eacd5ac26 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1957,22 +1957,22 @@ static void ip_handle_martian_source(struct net_device *dev,
 #endif
 }
 
+/* called in rcu_read_lock() section */
 static int __mkroute_input(struct sk_buff *skb,
 			   struct fib_result *res,
 			   struct in_device *in_dev,
 			   __be32 daddr, __be32 saddr, u32 tos,
 			   struct rtable **result)
 {
-
 	struct rtable *rth;
 	int err;
 	struct in_device *out_dev;
-	unsigned flags = 0;
+	unsigned int flags = 0;
 	__be32 spec_dst;
 	u32 itag;
 
 	/* get a working reference to the output device */
-	out_dev = in_dev_get(FIB_RES_DEV(*res));
+	out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
 	if (out_dev == NULL) {
 		if (net_ratelimit())
 			printk(KERN_CRIT "Bug in ip_route_input" \
@@ -2053,8 +2053,6 @@ static int __mkroute_input(struct sk_buff *skb,
 	*result = rth;
 	err = 0;
  cleanup:
-	/* release the working reference to the output device */
-	in_dev_put(out_dev);
 	return err;
 }