[Yakkety,SRU] net: use net->count to check whether a netns is alive or not

Message ID 1490898484-30787-1-git-send-email-tim.gardner@canonical.com
State New
Headers show

Commit Message

Tim Gardner March 30, 2017, 6:28 p.m.
From: Andrey Vagin <avagin@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@gmail.com>
Fixes: 002d8a1a6c11 ("net: skip genenerating uevents for network namespaces that are exiting")
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 91864f5852f9996210fad400cf70fb85af091243)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

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

Comments

Tim Gardner March 30, 2017, 6:30 p.m. | #1
Also for Xenial
Joseph Salisbury April 3, 2017, 4:09 p.m. | #2
Was this a backport versus a cherry-pick?

On 03/30/2017 07:28 PM, Tim Gardner wrote:
> From: Andrey Vagin <avagin@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@gmail.com>
> Fixes: 002d8a1a6c11 ("net: skip genenerating uevents for network namespaces that are exiting")
> Signed-off-by: Andrei Vagin <avagin@openvz.org>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> (cherry picked from commit 91864f5852f9996210fad400cf70fb85af091243)
> Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
>
> Conflicts:
> 	net/core/net-sysfs.c
> ---
>  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 6e4f347..dabd94c 100644
> --- a/net/core/net-sysfs.c
> +++ b/net/core/net-sysfs.c
> @@ -950,6 +950,10 @@ 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)
>  			sysfs_remove_group(&dev->_rx[i].kobj,
>  					   dev->sysfs_rx_queue_group);
> @@ -1340,6 +1344,8 @@ 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);
>  #endif
> @@ -1525,6 +1531,9 @@ 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);
> +
>  	kobject_get(&dev->kobj);
>  
>  	remove_queue_kobjects(ndev);
Tim Gardner April 3, 2017, 4:38 p.m. | #3
On 04/03/2017 05:09 PM, Joseph Salisbury wrote:
> Was this a backport versus a cherry-pick?
> 

Indeed it was a backport.

rtg

Patch

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 6e4f347..dabd94c 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -950,6 +950,10 @@  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)
 			sysfs_remove_group(&dev->_rx[i].kobj,
 					   dev->sysfs_rx_queue_group);
@@ -1340,6 +1344,8 @@  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);
 #endif
@@ -1525,6 +1531,9 @@  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);
+
 	kobject_get(&dev->kobj);
 
 	remove_queue_kobjects(ndev);