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>

1 files changed, 11 insertions, 16 deletions

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index bd24f6560a4..6110c6d6e61 100644
--- 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;