igmp: Use next_net_device_rcu()

We need to use next_det_device_rcu() in RCU protected section.

We also can avoid in_dev_get()/in_dev_put() overhead (code size mainly)
in rcu_read_lock() sections.

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

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index bd24f6560a492e2ec03e52b525008a18cd63e3d1..6110c6d6e61384491b18bf6734ade5cc381d90d0 100644 (file)
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2313,7 +2313,8 @@ static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
        state->in_dev = NULL;
        for_each_netdev_rcu(net, state->dev) {
                struct in_device *in_dev;
-               in_dev = in_dev_get(state->dev);
+
+               in_dev = __in_dev_get_rcu(state->dev);
                if (!in_dev)
                        continue;
                read_lock(&in_dev->mc_list_lock);
@@ -2323,7 +2324,6 @@ static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
                        break;
                }
                read_unlock(&in_dev->mc_list_lock);
-               in_dev_put(in_dev);
        }
        return im;
 }
@@ -2333,16 +2333,15 @@ static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_li
        struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
        im = im->next;
        while (!im) {
-               if (likely(state->in_dev != NULL)) {
+               if (likely(state->in_dev != NULL))
                        read_unlock(&state->in_dev->mc_list_lock);
-                       in_dev_put(state->in_dev);
-               }
-               state->dev = next_net_device(state->dev);
+
+               state->dev = next_net_device_rcu(state->dev);
                if (!state->dev) {
                        state->in_dev = NULL;
                        break;
                }
-               state->in_dev = in_dev_get(state->dev);
+               state->in_dev = __in_dev_get_rcu(state->dev);
                if (!state->in_dev)
                        continue;
                read_lock(&state->in_dev->mc_list_lock);
@@ -2384,7 +2383,6 @@ static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
        struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
        if (likely(state->in_dev != NULL)) {
                read_unlock(&state->in_dev->mc_list_lock);
-               in_dev_put(state->in_dev);
                state->in_dev = NULL;
        }
        state->dev = NULL;
@@ -2464,7 +2462,7 @@ static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
        state->im = NULL;
        for_each_netdev_rcu(net, state->dev) {
                struct in_device *idev;
-               idev = in_dev_get(state->dev);
+               idev = __in_dev_get_rcu(state->dev);
                if (unlikely(idev == NULL))
                        continue;
                read_lock(&idev->mc_list_lock);
@@ -2480,7 +2478,6 @@ static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
                        spin_unlock_bh(&im->lock);
                }
                read_unlock(&idev->mc_list_lock);
-               in_dev_put(idev);
        }
        return psf;
 }
@@ -2494,16 +2491,15 @@ static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_l
                spin_unlock_bh(&state->im->lock);
                state->im = state->im->next;
                while (!state->im) {
-                       if (likely(state->idev != NULL)) {
+                       if (likely(state->idev != NULL))
                                read_unlock(&state->idev->mc_list_lock);
-                               in_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;
                                goto out;
                        }
-                       state->idev = in_dev_get(state->dev);
+                       state->idev = __in_dev_get_rcu(state->dev);
                        if (!state->idev)
                                continue;
                        read_lock(&state->idev->mc_list_lock);
@@ -2555,7 +2551,6 @@ static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
        }
        if (likely(state->idev != NULL)) {
                read_unlock(&state->idev->mc_list_lock);
-               in_dev_put(state->idev);
                state->idev = NULL;
        }
        state->dev = NULL;