| Message ID | m1y6y04t50.fsf@frodo.ebiederm.org |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: ebiederm@xmission.com (Eric W. Biederman) Date: Sun, 28 Dec 2008 00:10:35 -0800 > During network namespace teardown we either move or delete > all of the network devices associated with a network namespace. > In the case of veth devices deleting one will also delete it's > pair device. If both devices are in the same network namespace > then for_each_netdev_safe is insufficient as next may point > to the second veth device we have deleted. > > To avoid problems I do what we do in __rtnl_kill_links and > restart the scan of the device list, after we have deleted > a device. > > Currently dev_change_netnamespace does not appear to suffer from > this problem, but wireless devices are also paired and likely > should be moved between network namespaces together. So I have > errored on the side of caution and restart the scan of the network > devices in that case as well. > > Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Looks good, applied. Thanks Eric. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/core/dev.c b/net/core/dev.c index daca72e..1f154d2 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5059,13 +5059,14 @@ static struct pernet_operations __net_initdata netdev_net_ops = { static void __net_exit default_device_exit(struct net *net) { - struct net_device *dev, *next; + struct net_device *dev; /* * Push all migratable of the network devices back to the * initial network namespace */ rtnl_lock(); - for_each_netdev_safe(net, dev, next) { +restart: + for_each_netdev(net, dev) { int err; char fb_name[IFNAMSIZ]; @@ -5076,7 +5077,7 @@ static void __net_exit default_device_exit(struct net *net) /* Delete virtual devices */ if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink) { dev->rtnl_link_ops->dellink(dev); - continue; + goto restart; } /* Push remaing network devices to init_net */ @@ -5087,6 +5088,7 @@ static void __net_exit default_device_exit(struct net *net) __func__, dev->name, err); BUG(); } + goto restart; } rtnl_unlock(); }
During network namespace teardown we either move or delete all of the network devices associated with a network namespace. In the case of veth devices deleting one will also delete it's pair device. If both devices are in the same network namespace then for_each_netdev_safe is insufficient as next may point to the second veth device we have deleted. To avoid problems I do what we do in __rtnl_kill_links and restart the scan of the device list, after we have deleted a device. Currently dev_change_netnamespace does not appear to suffer from this problem, but wireless devices are also paired and likely should be moved between network namespaces together. So I have errored on the side of caution and restart the scan of the network devices in that case as well. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> --- net/core/dev.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-)