[PATCH] openvswitch: do not ignore netdev errors when creating tunnel vports

[Martynas Pumputis]

The creation of a tunnel vport (geneve, gre, vxlan) brings up a
corresponding netdev, a multi-step operation which can fail.

For example, changing a vxlan vport's netdev state to 'up' binds the
vport's socket to a UDP port - if the binding fails (e.g. due to the
port being in use), the error is currently ignored giving the
appearance that the tunnel vport creation completed successfully.

Signed-off-by: Martynas Pumputis <martynas@weave.works>
---
 net/openvswitch/vport-geneve.c |  9 ++++++++-
 net/openvswitch/vport-gre.c    | 11 +++++++++--
 net/openvswitch/vport-vxlan.c  |  9 ++++++++-
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/net/openvswitch/vport-geneve.c b/net/openvswitch/vport-geneve.c
index 1a1fcec..5aaf3ba 100644
--- a/net/openvswitch/vport-geneve.c
+++ b/net/openvswitch/vport-geneve.c
@@ -93,7 +93,14 @@ static struct vport *geneve_tnl_create(const struct 
vport_parms *parms)
                return ERR_CAST(dev);
        }
 
-       dev_change_flags(dev, dev->flags | IFF_UP);
+       err = dev_change_flags(dev, dev->flags | IFF_UP);
+       if (err < 0) {
+               rtnl_delete_link(dev);
+               rtnl_unlock();
+               ovs_vport_free(vport);
+               goto error;
+       }
+
        rtnl_unlock();
        return vport;
 error:
diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
index 7f8897f..0e72d95 100644
--- a/net/openvswitch/vport-gre.c
+++ b/net/openvswitch/vport-gre.c
@@ -54,6 +54,7 @@ static struct vport *gre_tnl_create(const struct vport_parms 
*parms)
        struct net *net = ovs_dp_get_net(parms->dp);
        struct net_device *dev;
        struct vport *vport;
+       int err;
 
        vport = ovs_vport_alloc(0, &ovs_gre_vport_ops, parms);
        if (IS_ERR(vport))
@@ -67,9 +68,15 @@ static struct vport *gre_tnl_create(const struct vport_parms 
*parms)
                return ERR_CAST(dev);
        }
 
-       dev_change_flags(dev, dev->flags | IFF_UP);
-       rtnl_unlock();
+       err = dev_change_flags(dev, dev->flags | IFF_UP);
+       if (err < 0) {
+               rtnl_delete_link(dev);
+               rtnl_unlock();
+               ovs_vport_free(vport);
+               return ERR_PTR(err);
+       }
 
+       rtnl_unlock();
        return vport;
 }
 
diff --git a/net/openvswitch/vport-vxlan.c b/net/openvswitch/vport-vxlan.c
index 5eb7694..7eb955e 100644
--- a/net/openvswitch/vport-vxlan.c
+++ b/net/openvswitch/vport-vxlan.c
@@ -130,7 +130,14 @@ static struct vport *vxlan_tnl_create(const struct 
vport_parms *parms)
                return ERR_CAST(dev);
        }
 
-       dev_change_flags(dev, dev->flags | IFF_UP);
+       err = dev_change_flags(dev, dev->flags | IFF_UP);
+       if (err < 0) {
+               rtnl_delete_link(dev);
+               rtnl_unlock();
+               ovs_vport_free(vport);
+               goto error;
+       }
+
        rtnl_unlock();
        return vport;
 error:
-- 
2.9.0