[PATCH X/Y SRU] net: use net->count to check whether a netns is alive or not

Tim Gardner tim.gardner at canonical.com
Tue Apr 4 07:26:56 UTC 2017

From: Andrey Vagin <avagin at openvz.org>

BugLink: http://bugs.launchpad.net/bugs/1672144

The previous idea was to check whether a net namespace is in
net_exit_list or not. It doesn't work, because net->exit_list is used in
__register_pernet_operations and __unregister_pernet_operations where
all namespaces are added to a temporary list to make cleanup in a error
case, so list_empty(&net->exit_list) always returns false.

Reported-by: Mantas Mikul─Śnas <grawity at gmail.com>
Fixes: 002d8a1a6c11 ("net: skip genenerating uevents for network namespaces that are exiting")
Signed-off-by: Andrei Vagin <avagin at openvz.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
(back ported from commit 91864f5852f9996210fad400cf70fb85af091243)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>


V2 - noted that this is a back ported patch.

 net/core/net-sysfs.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index f88a62a..056b5ca 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -931,6 +931,10 @@ net_rx_queue_update_kobjects(struct net_device *dev, int old_num, int new_num)
 	while (--i >= new_num) {
+		struct kobject *kobj = &dev->_rx[i].kobj;
+		if (!atomic_read(&dev_net(dev)->count))
+			kobj->uevent_suppress = 1;
 		if (dev->sysfs_rx_queue_group)
@@ -1321,6 +1325,8 @@ netdev_queue_update_kobjects(struct net_device *dev, int old_num, int new_num)
 	while (--i >= new_num) {
 		struct netdev_queue *queue = dev->_tx + i;
+		if (!atomic_read(&dev_net(dev)->count))
+			queue->kobj.uevent_suppress = 1;
 #ifdef CONFIG_BQL
 		sysfs_remove_group(&queue->kobj, &dql_group);
@@ -1506,6 +1512,9 @@ void netdev_unregister_kobject(struct net_device *ndev)
 	struct device *dev = &(ndev->dev);
+	if (!atomic_read(&dev_net(ndev)->count))
+		dev_set_uevent_suppress(dev, 1);

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