• S
    net: dev_change_net_namespace: send a KOBJ_REMOVED/KOBJ_ADD · 4e66ae2e
    Serge Hallyn 提交于
    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: NSerge Hallyn <serge.hallyn@canonical.com>
    Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
    Acked-by: NDaniel Lezcano <daniel.lezcano@free.fr>
    Signed-off-by: NDavid S. Miller <davem@davemloft.net>
    4e66ae2e
dev.c 166.3 KB