Commit fb5d1e9e authored by Jarno Rajahalme's avatar Jarno Rajahalme Committed by Pravin B Shelar

openvswitch: Build flow cmd netlink reply only if needed.

Use netlink_has_listeners() and NLM_F_ECHO flag to determine if a
reply is needed or not for OVS_FLOW_CMD_NEW, OVS_FLOW_CMD_SET, or
OVS_FLOW_CMD_DEL.  Currently, OVS userspace does not request a reply
for OVS_FLOW_CMD_NEW, but usually does for OVS_FLOW_CMD_DEL, as stats
may have changed.
Signed-off-by: default avatarJarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: default avatarPravin B Shelar <pshelar@nicira.com>
parent bb6f9a70
......@@ -62,6 +62,15 @@
int ovs_net_id __read_mostly;
/* Check if need to build a reply message.
* OVS userspace sets the NLM_F_ECHO flag if it needs the reply. */
static bool ovs_must_notify(struct genl_info *info,
const struct genl_multicast_group *grp)
{
return info->nlhdr->nlmsg_flags & NLM_F_ECHO ||
netlink_has_listeners(genl_info_net(info)->genl_sock, 0);
}
static void ovs_notify(struct genl_family *family,
struct sk_buff *skb, struct genl_info *info)
{
......@@ -746,27 +755,36 @@ error:
/* Must be called with ovs_mutex. */
static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow,
struct genl_info *info)
struct genl_info *info,
bool always)
{
struct sk_buff *skb;
size_t len;
if (!always && !ovs_must_notify(info, &ovs_dp_flow_multicast_group))
return NULL;
len = ovs_flow_cmd_msg_size(ovsl_dereference(flow->sf_acts));
return genlmsg_new_unicast(len, info, GFP_KERNEL);
skb = genlmsg_new_unicast(len, info, GFP_KERNEL);
if (!skb)
return ERR_PTR(-ENOMEM);
return skb;
}
/* Must be called with ovs_mutex. */
static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
struct datapath *dp,
struct genl_info *info,
u8 cmd)
u8 cmd, bool always)
{
struct sk_buff *skb;
int retval;
skb = ovs_flow_cmd_alloc_info(flow, info);
if (!skb)
return ERR_PTR(-ENOMEM);
skb = ovs_flow_cmd_alloc_info(flow, info, always);
if (!skb || IS_ERR(skb))
return skb;
retval = ovs_flow_cmd_fill_info(flow, dp, skb, info->snd_portid,
info->snd_seq, 0, cmd);
......@@ -850,7 +868,8 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
goto err_flow_free;
}
reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
reply = ovs_flow_cmd_build_info(flow, dp, info,
OVS_FLOW_CMD_NEW, false);
} else {
/* We found a matching flow. */
/* Bail out if we're not allowed to modify an existing flow.
......@@ -876,7 +895,8 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
rcu_assign_pointer(flow->sf_acts, acts);
ovs_nla_free_flow_actions(old_acts);
}
reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
reply = ovs_flow_cmd_build_info(flow, dp, info,
OVS_FLOW_CMD_NEW, false);
/* Clear stats. */
if (a[OVS_FLOW_ATTR_CLEAR])
......@@ -884,11 +904,14 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
}
ovs_unlock();
if (!IS_ERR(reply))
ovs_notify(&dp_flow_genl_family, reply, info);
else
genl_set_err(&dp_flow_genl_family, sock_net(skb->sk), 0,
0, PTR_ERR(reply));
if (reply) {
if (!IS_ERR(reply))
ovs_notify(&dp_flow_genl_family, reply, info);
else
genl_set_err(&dp_flow_genl_family, sock_net(skb->sk), 0,
0, PTR_ERR(reply));
}
return 0;
err_flow_free:
......@@ -935,7 +958,7 @@ static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
goto unlock;
}
reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW, true);
if (IS_ERR(reply)) {
err = PTR_ERR(reply);
goto unlock;
......@@ -982,22 +1005,25 @@ static int ovs_flow_cmd_del(struct sk_buff *skb, struct genl_info *info)
goto unlock;
}
reply = ovs_flow_cmd_alloc_info(flow, info);
if (!reply) {
err = -ENOMEM;
reply = ovs_flow_cmd_alloc_info(flow, info, false);
if (IS_ERR(reply)) {
err = PTR_ERR(reply);
goto unlock;
}
ovs_flow_tbl_remove(&dp->table, flow);
err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
info->snd_seq, 0, OVS_FLOW_CMD_DEL);
BUG_ON(err < 0);
if (reply) {
err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
info->snd_seq, 0,
OVS_FLOW_CMD_DEL);
BUG_ON(err < 0);
}
ovs_flow_free(flow, true);
ovs_unlock();
ovs_notify(&dp_flow_genl_family, reply, info);
if (reply)
ovs_notify(&dp_flow_genl_family, reply, info);
return 0;
unlock:
ovs_unlock();
......
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