netns: keep vlan slaves on master netns move

previously, if a vlan master device was moved from one network namespace
to another, all 802.1q and macvlan slaves were deleted.

we can use dev->reg_state to figure out whether dev_change_net_namespace
is happening, since that won't set dev->reg_state NETREG_UNREGISTERING.
so, this changes 8021q and macvlan to ignore NETDEV_UNREGISTER when
reg_state is not NETREG_UNREGISTERING.

Signed-off-by: David Lamparter <equinox@diac24.net>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 0ef0eb0..0fc9dc7 100644 (file)
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -788,6 +788,10 @@ static int macvlan_device_event(struct notifier_block *unused,
                }
                break;
        case NETDEV_UNREGISTER:
+               /* twiddle thumbs on netns device moves */
+               if (dev->reg_state != NETREG_UNREGISTERING)
+                       break;
+
                list_for_each_entry_safe(vlan, next, &port->vlans, list)
                        vlan->dev->rtnl_link_ops->dellink(vlan->dev, NULL);
                break;

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index a2ad152..2c6c2bd 100644 (file)
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -525,6 +525,10 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
                break;
 
        case NETDEV_UNREGISTER:
+               /* twiddle thumbs on netns device moves */
+               if (dev->reg_state != NETREG_UNREGISTERING)
+                       break;
+
                /* Delete all VLANs for this dev. */
                grp->killall = 1;
 

diff --git a/net/core/dev.c b/net/core/dev.c
index c09ff09..2c7934f 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5686,6 +5686,10 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 
        /* Notify protocols, that we are about to destroy
           this device. They should clean all the things.
+
+          Note that dev->reg_state stays at NETREG_REGISTERED.
+          This is wanted because this way 8021q and macvlan know
+          the device is just moving and can keep their slaves up.
        */
        call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
        call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);