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Commit ce81b76a authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

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: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bee7ca9e

include/linux/netdevice.h

+10 −0
Original line number Diff line number Diff line
@@ -1114,6 +1114,16 @@ static inline struct net_device *next_net_device(struct net_device *dev) 
	return lh == &net->dev_base_head ? NULL : net_device_entry(lh);

}



static inline struct net_device *next_net_device_rcu(struct net_device *dev)

{

	struct list_head *lh;

	struct net *net;



	net = dev_net(dev);

	lh = rcu_dereference(dev->dev_list.next);

	return lh == &net->dev_base_head ? NULL : net_device_entry(lh);

}



static inline struct net_device *first_net_device(struct net *net)

{

	return list_empty(&net->dev_base_head) ? NULL :

net/ipv6/anycast.c

+14 −15
Original line number Diff line number Diff line
@@ -431,9 +431,9 @@ static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq) 
	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 @@ static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq) 
			break;

		}

		read_unlock_bh(&idev->lock);

		in6_dev_put(idev);

	}

	return im;

}
@@ -454,16 +453,15 @@ static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im 


	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 struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos) 
}



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)

net/ipv6/mcast.c

+23 −28
Original line number Diff line number Diff line
@@ -2375,9 +2375,9 @@ static inline struct ifmcaddr6 *igmp6_mc_get_first(struct seq_file *seq) 
	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 @@ static inline struct ifmcaddr6 *igmp6_mc_get_first(struct seq_file *seq) 
			break;

		}

		read_unlock_bh(&idev->lock);

		in6_dev_put(idev);

	}

	return im;

}
@@ -2398,16 +2397,15 @@ static struct ifmcaddr6 *igmp6_mc_get_next(struct seq_file *seq, struct ifmcaddr 


	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 struct ifmcaddr6 *igmp6_mc_get_idx(struct seq_file *seq, loff_t pos) 
}



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 @@ static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq) 


	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 @@ static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq) 
			spin_unlock_bh(&im->mca_lock);

		}

		read_unlock_bh(&idev->lock);

		in6_dev_put(idev);

	}

	return psf;

}
@@ -2539,16 +2536,15 @@ static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_s 
		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 struct ip6_sf_list *igmp6_mcf_get_idx(struct seq_file *seq, loff_t pos) 
}



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_next(struct seq_file *seq, void *v, loff_t *pos) 
}



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 @@ static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v) 
	}

	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)