[PATCH net-next 01/11] openvswitch: Use RCU lock for flow dump operation.
From: Jesse Gross <hidden>
Date: 2013-08-27 20:20:38
Subsystem:
networking [general], openvswitch, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Aaron Conole, Eelco Chaudron, Ilya Maximets, Linus Torvalds
From: Pravin B Shelar <redacted> Flow dump operation is read-only operation. There is no need to take ovs-lock. Following patch use rcu-lock for dumping flows. Signed-off-by: Pravin B Shelar <redacted> Signed-off-by: Jesse Gross <redacted> --- net/openvswitch/datapath.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index f2ed760..e6fb866 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c@@ -1104,7 +1104,6 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp, u32 seq, u32 flags, u8 cmd) { const int skb_orig_len = skb->len; - const struct sw_flow_actions *sf_acts; struct nlattr *start; struct ovs_flow_stats stats; struct ovs_header *ovs_header;
@@ -1113,8 +1112,6 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp, u8 tcp_flags; int err; - sf_acts = ovsl_dereference(flow->sf_acts); - ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family, flags, cmd); if (!ovs_header) return -EMSGSIZE;
@@ -1161,6 +1158,11 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp, */ start = nla_nest_start(skb, OVS_FLOW_ATTR_ACTIONS); if (start) { + const struct sw_flow_actions *sf_acts; + + sf_acts = rcu_dereference_check(flow->sf_acts, + lockdep_ovsl_is_held()); + err = actions_to_attr(sf_acts->actions, sf_acts->actions_len, skb); if (!err) nla_nest_end(skb, start);
@@ -1440,15 +1442,14 @@ static int ovs_flow_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb) struct datapath *dp; struct flow_table *table; - ovs_lock(); + rcu_read_lock(); dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex); if (!dp) { - ovs_unlock(); + rcu_read_unlock(); return -ENODEV; } - table = ovsl_dereference(dp->table); - + table = rcu_dereference(dp->table); for (;;) { struct sw_flow *flow; u32 bucket, obj;
@@ -1468,7 +1469,7 @@ static int ovs_flow_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb) cb->args[0] = bucket; cb->args[1] = obj; } - ovs_unlock(); + rcu_read_unlock(); return skb->len; }
--
1.8.1.2