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From: David Ahern <dsahern@gmail•com>
To: netdev@vger•kernel.org
Cc: davem@davemloft•net, idosch@idosch•org,
	roopa@cumulusnetworks•com, eric.dumazet@gmail•com,
	weiwan@google•com, kafai@fb•com, yoshfuji@linux-ipv6•org,
	David Ahern <dsahern@gmail•com>
Subject: [PATCH net-next 3/7] net/ipv6: Move rcu_read_lock to callers of ip6_rt_cache_alloc
Date: Fri, 20 Apr 2018 15:37:59 -0700	[thread overview]
Message-ID: <20180420223803.15743-4-dsahern@gmail.com> (raw)
In-Reply-To: <20180420223803.15743-1-dsahern@gmail.com>

A later patch protects 'from' in rt6_info and this simplifies the
locking needed by it.

With the move, the fib6_info_hold for the uncached_rt is no longer
needed since the rcu_lock is still held.

Signed-off-by: David Ahern <dsahern@gmail•com>
---
 net/ipv6/route.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2d6fcfe11c82..f8b22183b7fd 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1164,10 +1164,8 @@ static struct rt6_info *ip6_rt_cache_alloc(struct fib6_info *ort,
 	 *	Clone the route.
 	 */
 
-	rcu_read_lock();
 	dev = ip6_rt_get_dev_rcu(ort);
 	rt = ip6_dst_alloc(dev_net(dev), dev, 0);
-	rcu_read_unlock();
 	if (!rt)
 		return NULL;
 
@@ -1855,14 +1853,11 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
 		 * the daddr in the skb during the neighbor look-up is different
 		 * from the fl6->daddr used to look-up route here.
 		 */
-
 		struct rt6_info *uncached_rt;
 
-		fib6_info_hold(f6i);
-		rcu_read_unlock();
-
 		uncached_rt = ip6_rt_cache_alloc(f6i, &fl6->daddr, NULL);
-		fib6_info_release(f6i);
+
+		rcu_read_unlock();
 
 		if (uncached_rt) {
 			/* Uncached_rt's refcnt is taken during ip6_rt_cache_alloc()
@@ -2280,7 +2275,9 @@ static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
 	} else if (daddr) {
 		struct rt6_info *nrt6;
 
+		rcu_read_lock();
 		nrt6 = ip6_rt_cache_alloc(rt6->from, daddr, saddr);
+		rcu_read_unlock();
 		if (nrt6) {
 			rt6_do_update_pmtu(nrt6, mtu);
 			if (rt6_insert_exception(nrt6, rt6->from))
@@ -3299,7 +3296,9 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
 				     NEIGH_UPDATE_F_ISROUTER)),
 		     NDISC_REDIRECT, &ndopts);
 
+	rcu_read_lock();
 	nrt = ip6_rt_cache_alloc(rt->from, &msg->dest, NULL);
+	rcu_read_unlock();
 	if (!nrt)
 		goto out;
 
-- 
2.11.0

  parent reply	other threads:[~2018-04-20 22:38 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-20 22:37 [PATCH net-next 0/7] net/ipv6: Another followup to the fib6_info change David Ahern
2018-04-20 22:37 ` [PATCH net-next 1/7] net/ipv6: Clean up rt expires helpers David Ahern
2018-04-20 22:37 ` [PATCH net-next 2/7] net/ipv6: Rename rt6_get_cookie_safe David Ahern
2018-04-20 22:37 ` David Ahern [this message]
2018-04-20 22:38 ` [PATCH net-next 4/7] net/ipv6: Move rcu locking to callers of fib6_get_cookie_safe David Ahern
2018-04-20 22:38 ` [PATCH net-next 5/7] net/ipv6: Move release of fib6_info from pcpu routes to helper David Ahern
2018-04-20 22:38 ` [PATCH net-next 6/7] net/ipv6: Make from in rt6_info rcu protected David Ahern
2018-04-20 22:38 ` [PATCH net-next 7/7] net/ipv6: Remove unncessary check on f6i in fib6_check David Ahern
2018-04-21 20:06 ` [PATCH net-next 0/7] net/ipv6: Another followup to the fib6_info change David Miller

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