[PATCH v2 net-next 8/8] vxlan: no longer rely on RTNL in vxlan_fill_info()

[Eric Dumazet <edumazet@google.com>]

Now that vxlan->cfg is RCU-protected, we can update vxlan_fill_info()
to run under RCU read lock instead of relying on RTNL.

This completes the transition to RTNL-less link info dumping for VXLAN.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 drivers/net/vxlan/vxlan_core.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 2b7da90ae2da3d0d8cc305d24d071cbc74ec2e6e..fd993a95501b02cc7891b434b258420de1ba4c21 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -4712,8 +4712,14 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	const struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct ifla_vxlan_port_range ports;
 	const struct vxlan_config *cfg;
+	int err = 0;
 
-	cfg = rtnl_dereference(vxlan->cfg);
+	rcu_read_lock();
+	cfg = rcu_dereference(vxlan->cfg);
+	if (!cfg) {
+		err = -ENODEV;
+		goto out;
+	}
 
 	if (nla_put_u32(skb, IFLA_VXLAN_ID, be32_to_cpu(cfg->vni)))
 		goto nla_put_failure;
@@ -4812,9 +4818,12 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 		    &cfg->reserved_bits))
 		goto nla_put_failure;
 
-	return 0;
+out:
+	rcu_read_unlock();
+	return err;
 
 nla_put_failure:
+	rcu_read_unlock();
 	return -EMSGSIZE;
 }
 
-- 
2.55.0.979.g7e5102b832-goog