Commit 70d2db7b authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'rt6_probe_write_lock' 



Martin KaFai Lau says:

====================
ipv6: Avoid rt6_probe() taking writer lock in the fast path

v1 -> v2:
1. Separate the code re-arrangement into another patch
2. Fix style
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 205845a3 8d6c31bf

net/ipv6/route.c

+21 −21
Original line number Diff line number Diff line
@@ -545,6 +545,7 @@ static void rt6_probe_deferred(struct work_struct *w) 


static void rt6_probe(struct rt6_info *rt)

{

	struct __rt6_probe_work *work;

	struct neighbour *neigh;

	/*

	 * Okay, this does not seem to be appropriate
@@ -559,22 +560,23 @@ static void rt6_probe(struct rt6_info *rt) 
	rcu_read_lock_bh();

	neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);

	if (neigh) {

		write_lock(&neigh->lock);

		if (neigh->nud_state & NUD_VALID)

			goto out;

	}



	if (!neigh ||

	    time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {

		struct __rt6_probe_work *work;



		work = NULL;

		write_lock(&neigh->lock);

		if (!(neigh->nud_state & NUD_VALID) &&

		    time_after(jiffies,

			       neigh->updated +

			       rt->rt6i_idev->cnf.rtr_probe_interval)) {

			work = kmalloc(sizeof(*work), GFP_ATOMIC);



		if (neigh && work)

			if (work)

				__neigh_set_probe_once(neigh);



		if (neigh)

		}

		write_unlock(&neigh->lock);

	} else {

		work = kmalloc(sizeof(*work), GFP_ATOMIC);

	}



	if (work) {

		INIT_WORK(&work->work, rt6_probe_deferred);
@@ -583,10 +585,8 @@ static void rt6_probe(struct rt6_info *rt) 
		work->dev = rt->dst.dev;

		schedule_work(&work->work);

	}

	} else {



out:

		write_unlock(&neigh->lock);

	}

	rcu_read_unlock_bh();

}

#else