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: Andy Zhou <azhou@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
This commit is contained in:
Andy Zhou 2014-09-08 13:14:22 -07:00 committed by Pravin B Shelar
parent ca7105f278
commit cc3a5ae6f2

View file

@ -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 *,
const struct dp_upcall_info *);
/* Must be called with rcu_read_lock or ovs_mutex. */
static struct datapath *get_dp(struct net *net, int dp_ifindex)
/* Must be called with rcu_read_lock. */
static struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
{
struct datapath *dp = NULL;
struct net_device *dev;
struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
rcu_read_lock();
dev = dev_get_by_index_rcu(net, dp_ifindex);
if (dev) {
struct vport *vport = ovs_internal_dev_get_vport(dev);
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();
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;
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;
if (!dp)
goto err_unlock;
@ -1227,7 +1238,7 @@ static int ovs_flow_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
struct datapath *dp;
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) {
rcu_read_unlock();
return -ENODEV;
@ -1989,7 +2000,7 @@ static int ovs_vport_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
int i, j = 0;
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) {
rcu_read_unlock();
return -ENODEV;