From 56bfa7ee7c8892f1aa61797e4b8fec84b31d29b3 Mon Sep 17 00:00:00 2001 From: Roopa Prabhu Date: Thu, 1 May 2014 11:40:30 -0700 Subject: [PATCH] unregister_netdevice : move RTM_DELLINK to until after ndo_uninit This patch fixes ordering of rtnl notifications during unregister_netdevice by moving RTM_DELLINK notification to until after ndo_uninit. The problem was seen with unregistering bond netdevices. bond ndo_uninit callback generates a few RTM_NEWLINK notifications for NETDEV_CHANGEADDR and NETDEV_FEAT_CHANGE. This is seen mostly when the bond is deleted with slaves still enslaved to the bond. During unregister netdevice (rollback_registered_many to be specific) bond ndo_uninit is called after RTM_DELLINK notification goes out. This results in userspace seeing RTM_DELLINK followed by a couple of RTM_NEWLINK's. In userspace problem was seen with libnl. libnl cache deletes the bond when it sees RTM_DELLINK and re-adds the bond with the following RTM_NEWLINK. Resulting in a stale bond entry in libnl cache when the kernel has already deleted the bond. This patch has been tested for bond, bridges and vlan devices. Signed-off-by: Roopa Prabhu Signed-off-by: David S. Miller --- net/core/dev.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 11d70e3afefa..fe0b9cd69cb6 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5606,10 +5606,6 @@ static void rollback_registered_many(struct list_head *head) */ call_netdevice_notifiers(NETDEV_UNREGISTER, dev); - if (!dev->rtnl_link_ops || - dev->rtnl_link_state == RTNL_LINK_INITIALIZED) - rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL); - /* * Flush the unicast and multicast chains */ @@ -5619,6 +5615,10 @@ static void rollback_registered_many(struct list_head *head) if (dev->netdev_ops->ndo_uninit) dev->netdev_ops->ndo_uninit(dev); + if (!dev->rtnl_link_ops || + dev->rtnl_link_state == RTNL_LINK_INITIALIZED) + rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL); + /* Notifier chain MUST detach us all upper devices. */ WARN_ON(netdev_has_any_upper_dev(dev)); -- 2.20.1