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authorAndy Zhou <azhou@nicira.com>2014-09-09 00:14:22 +0400
committerPravin B Shelar <pshelar@nicira.com>2014-11-06 10:52:34 +0300
commitcc3a5ae6f23336ddc1d136a66c0a6a60276e99a3 (patch)
tree6c3af8e0e35ca25c331659a7f6c5c057158ba1d4 /net/openvswitch
parentca7105f278b3f7bd2c6f2b336c928f679054de4d (diff)
downloadlinux-cc3a5ae6f23336ddc1d136a66c0a6a60276e99a3.tar.xz
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>
Diffstat (limited to 'net/openvswitch')
-rw-r--r--net/openvswitch/datapath.c31
1 files changed, 21 insertions, 10 deletions
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index bbb920bf48da..cdbc44c18714 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -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;