When a new nic is created in namespace ns1, the kernel sends a KOBJ_ADD uevent to ns1. When the nic is moved to ns2, we only send a KOBJ_MOVE to ns2, and nothing to ns1.
This patch changes that behavior so that when moving a nic from ns1 to ns2, we send a KOBJ_REMOVED to ns1 and KOBJ_ADD to ns2. (The KOBJ_MOVE is still sent to ns2). The effects of this can be seen when starting and stopping containers in an upstart based host. Lxc will create a pair of veth nics, the kernel sends KOBJ_ADD, and upstart starts network-instance jobs for each. When one nic is moved to the container, because no KOBJ_REMOVED event is received, the network-instance job for that veth never goes away. This was reported at https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1065589 With this patch the networ-instance jobs properly go away. The other oddness solved here is that if a nic is passed into a running upstart-based container, without this patch no network-instance job is started in the container. But when the container creates a new nic itself (ip link add new type veth) then network-interface jobs are created. With this patch, behavior comes in line with a regular host. v2: also send KOBJ_ADD to new netns. There will then be a _MOVE event from the device_rename() call, but that should be innocuous. Signed-off-by: Serge Hallyn <serge.hal...@canonical.com> Acked-by: "Eric W. Biederman" <ebied...@xmission.com> Acked-by: Daniel Lezcano <daniel.lezc...@free.fr> --- net/core/dev.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index e2215ee..2c43aaf 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6172,6 +6172,9 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char dev_uc_flush(dev); dev_mc_flush(dev); + /* Send a netdev-removed uevent to the old namespace */ + kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE); + /* Actually switch the network namespace */ dev_net_set(dev, net); @@ -6183,6 +6186,9 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char dev->iflink = dev->ifindex; } + /* Send a netdev-add uevent to the new namespace */ + kobject_uevent(&dev->dev.kobj, KOBJ_ADD); + /* Fixup kobjects */ err = device_rename(&dev->dev, dev->name); WARN_ON(err); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
