ipv6: use RCU to walk list of network devices
No longer need read_lock(&dev_base_lock), use RCU instead.
We also can avoid taking references on inet6_dev structs.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 2f00ca8..f1c74c8 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -431,9 +431,9 @@
struct net *net = seq_file_net(seq);
state->idev = NULL;
- for_each_netdev(net, state->dev) {
+ for_each_netdev_rcu(net, state->dev) {
struct inet6_dev *idev;
- idev = in6_dev_get(state->dev);
+ idev = __in6_dev_get(state->dev);
if (!idev)
continue;
read_lock_bh(&idev->lock);
@@ -443,7 +443,6 @@
break;
}
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
}
return im;
}
@@ -454,16 +453,15 @@
im = im->aca_next;
while (!im) {
- if (likely(state->idev != NULL)) {
+ if (likely(state->idev != NULL))
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
- }
- state->dev = next_net_device(state->dev);
+
+ state->dev = next_net_device_rcu(state->dev);
if (!state->dev) {
state->idev = NULL;
break;
}
- state->idev = in6_dev_get(state->dev);
+ state->idev = __in6_dev_get(state->dev);
if (!state->idev)
continue;
read_lock_bh(&state->idev->lock);
@@ -482,29 +480,30 @@
}
static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(dev_base_lock)
+ __acquires(RCU)
{
- read_lock(&dev_base_lock);
+ rcu_read_lock();
return ac6_get_idx(seq, *pos);
}
static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- struct ifacaddr6 *im;
- im = ac6_get_next(seq, v);
+ struct ifacaddr6 *im = ac6_get_next(seq, v);
+
++*pos;
return im;
}
static void ac6_seq_stop(struct seq_file *seq, void *v)
- __releases(dev_base_lock)
+ __releases(RCU)
{
struct ac6_iter_state *state = ac6_seq_private(seq);
+
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
+ state->idev = NULL;
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
static int ac6_seq_show(struct seq_file *seq, void *v)