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/mcast.c b/net/ipv6/mcast.c
index f9fcf69..1f9c444 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -2375,9 +2375,9 @@
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);
@@ -2387,7 +2387,6 @@
break;
}
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
}
return im;
}
@@ -2398,16 +2397,15 @@
im = im->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);
@@ -2426,31 +2424,31 @@
}
static void *igmp6_mc_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(dev_base_lock)
+ __acquires(RCU)
{
- read_lock(&dev_base_lock);
+ rcu_read_lock();
return igmp6_mc_get_idx(seq, *pos);
}
static void *igmp6_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- struct ifmcaddr6 *im;
- im = igmp6_mc_get_next(seq, v);
+ struct ifmcaddr6 *im = igmp6_mc_get_next(seq, v);
+
++*pos;
return im;
}
static void igmp6_mc_seq_stop(struct seq_file *seq, void *v)
- __releases(dev_base_lock)
+ __releases(RCU)
{
struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
+
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
state->idev = NULL;
}
state->dev = NULL;
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
static int igmp6_mc_seq_show(struct seq_file *seq, void *v)
@@ -2507,9 +2505,9 @@
state->idev = NULL;
state->im = 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 (unlikely(idev == NULL))
continue;
read_lock_bh(&idev->lock);
@@ -2525,7 +2523,6 @@
spin_unlock_bh(&im->mca_lock);
}
read_unlock_bh(&idev->lock);
- in6_dev_put(idev);
}
return psf;
}
@@ -2539,16 +2536,15 @@
spin_unlock_bh(&state->im->mca_lock);
state->im = state->im->next;
while (!state->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;
goto out;
}
- state->idev = in6_dev_get(state->dev);
+ state->idev = __in6_dev_get(state->dev);
if (!state->idev)
continue;
read_lock_bh(&state->idev->lock);
@@ -2573,9 +2569,9 @@
}
static void *igmp6_mcf_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(dev_base_lock)
+ __acquires(RCU)
{
- read_lock(&dev_base_lock);
+ rcu_read_lock();
return *pos ? igmp6_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
@@ -2591,7 +2587,7 @@
}
static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v)
- __releases(dev_base_lock)
+ __releases(RCU)
{
struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
if (likely(state->im != NULL)) {
@@ -2600,11 +2596,10 @@
}
if (likely(state->idev != NULL)) {
read_unlock_bh(&state->idev->lock);
- in6_dev_put(state->idev);
state->idev = NULL;
}
state->dev = NULL;
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
}
static int igmp6_mcf_seq_show(struct seq_file *seq, void *v)
