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Commit cc3a5ae6 authored by Andy Zhou's avatar Andy Zhou Committed by Pravin B Shelar
Browse files

openvswitch: Refactor get_dp() function into multiple access APIs. 



Avoid recursive read_rcu_lock() by using the lighter weight
get_dp_rcu() API. Add proper locking assertions to get_dp().

Signed-off-by: default avatarAndy Zhou <azhou@nicira.com>
Signed-off-by: default avatarPravin B Shelar <pshelar@nicira.com>
parent ca7105f2

net/openvswitch/datapath.c

+21 −10
Original line number Original line Diff line number Diff line
@@ -140,19 +140,30 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *, 
static int queue_userspace_packet(struct datapath *dp, struct sk_buff *,

static int queue_userspace_packet(struct datapath *dp, struct sk_buff *,

				  const struct dp_upcall_info *);

				  const struct dp_upcall_info *);





/* Must be called with rcu_read_lock or ovs_mutex. */

/* Must be called with rcu_read_lock. */

static struct datapath *get_dp(struct net *net, int dp_ifindex)

static struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)

{

{

	struct datapath *dp = NULL;

	struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);

	struct net_device *dev;





	rcu_read_lock();

	dev = dev_get_by_index_rcu(net, dp_ifindex);

	if (dev) {

	if (dev) {

		struct vport *vport = ovs_internal_dev_get_vport(dev);

		struct vport *vport = ovs_internal_dev_get_vport(dev);

		if (vport)

		if (vport)

			dp = vport->dp;

			return vport->dp;

	}



	return NULL;

}

}



/* The caller must hold either ovs_mutex or rcu_read_lock to keep the

 * returned dp pointer valid.

 */

static inline struct datapath *get_dp(struct net *net, int dp_ifindex)

{

	struct datapath *dp;



	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());

	rcu_read_lock();

	dp = get_dp_rcu(net, dp_ifindex);

	rcu_read_unlock();

	rcu_read_unlock();





	return dp;

	return dp;
@@ -573,7 +584,7 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info) 
	packet->mark = flow->key.phy.skb_mark;

	packet->mark = flow->key.phy.skb_mark;





	rcu_read_lock();

	rcu_read_lock();

	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);

	dp = get_dp_rcu(sock_net(skb->sk), ovs_header->dp_ifindex);

	err = -ENODEV;

	err = -ENODEV;

	if (!dp)

	if (!dp)

		goto err_unlock;

		goto err_unlock;
@@ -1227,7 +1238,7 @@ static int ovs_flow_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb) 
	struct datapath *dp;

	struct datapath *dp;





	rcu_read_lock();

	rcu_read_lock();

	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);

	dp = get_dp_rcu(sock_net(skb->sk), ovs_header->dp_ifindex);

	if (!dp) {

	if (!dp) {

		rcu_read_unlock();

		rcu_read_unlock();

		return -ENODEV;

		return -ENODEV;
@@ -1989,7 +2000,7 @@ static int ovs_vport_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb) 
	int i, j = 0;

	int i, j = 0;





	rcu_read_lock();

	rcu_read_lock();

	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);

	dp = get_dp_rcu(sock_net(skb->sk), ovs_header->dp_ifindex);

	if (!dp) {

	if (!dp) {

		rcu_read_unlock();

		rcu_read_unlock();

		return -ENODEV;

		return -ENODEV;