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

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
...@@ -545,6 +545,7 @@ static void rt6_probe_deferred(struct work_struct *w) ...@@ -545,6 +545,7 @@ static void rt6_probe_deferred(struct work_struct *w)
static void rt6_probe(struct rt6_info *rt) static void rt6_probe(struct rt6_info *rt)
{ {
struct __rt6_probe_work *work;
struct neighbour *neigh; struct neighbour *neigh;
/* /*
* Okay, this does not seem to be appropriate * Okay, this does not seem to be appropriate
...@@ -559,22 +560,23 @@ static void rt6_probe(struct rt6_info *rt) ...@@ -559,22 +560,23 @@ static void rt6_probe(struct rt6_info *rt)
rcu_read_lock_bh(); rcu_read_lock_bh();
neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway); neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
if (neigh) { if (neigh) {
write_lock(&neigh->lock);
if (neigh->nud_state & NUD_VALID) if (neigh->nud_state & NUD_VALID)
goto out; 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); work = kmalloc(sizeof(*work), GFP_ATOMIC);
if (work)
if (neigh && work)
__neigh_set_probe_once(neigh); __neigh_set_probe_once(neigh);
}
if (neigh)
write_unlock(&neigh->lock); write_unlock(&neigh->lock);
} else {
work = kmalloc(sizeof(*work), GFP_ATOMIC);
}
if (work) { if (work) {
INIT_WORK(&work->work, rt6_probe_deferred); INIT_WORK(&work->work, rt6_probe_deferred);
...@@ -583,10 +585,8 @@ static void rt6_probe(struct rt6_info *rt) ...@@ -583,10 +585,8 @@ static void rt6_probe(struct rt6_info *rt)
work->dev = rt->dst.dev; work->dev = rt->dst.dev;
schedule_work(&work->work); schedule_work(&work->work);
} }
} else {
out: out:
write_unlock(&neigh->lock);
}
rcu_read_unlock_bh(); rcu_read_unlock_bh();
} }
#else #else
......
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