[patch net] devlink: change port event netdev notifier from per-net to global

[patch net] devlink: change port event netdev notifier from per-net to global

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Currently only the network namespace of devlink instance is monitored
for port events. If netdev is moved to a different namespace and then
unregistered, NETDEV_PRE_UNINIT is missed which leads to trigger
following WARN_ON in devl_port_unregister().
WARN_ON(devlink_port->type != DEVLINK_PORT_TYPE_NOTSET);

Fix this by changing the netdev notifier from per-net to global so no
event is missed.

Fixes: 02a68a47eade ("net: devlink: track netdev with devlink_port assigned")
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 net/core/devlink.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 032d6d0a5ce6..909a10e4b0dd 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -9979,7 +9979,7 @@ struct devlink *devlink_alloc_ns(const struct devlink_ops *ops,
 		goto err_xa_alloc;
 
 	devlink->netdevice_nb.notifier_call = devlink_netdevice_event;
-	ret = register_netdevice_notifier_net(net, &devlink->netdevice_nb);
+	ret = register_netdevice_notifier(&devlink->netdevice_nb);
 	if (ret)
 		goto err_register_netdevice_notifier;
 
@@ -10171,8 +10171,7 @@ void devlink_free(struct devlink *devlink)
 	xa_destroy(&devlink->snapshot_ids);
 	xa_destroy(&devlink->ports);
 
-	WARN_ON_ONCE(unregister_netdevice_notifier_net(devlink_net(devlink),
-						       &devlink->netdevice_nb));
+	WARN_ON_ONCE(unregister_netdevice_notifier(&devlink->netdevice_nb));
 
 	xa_erase(&devlinks, devlink->index);
 
@@ -10503,6 +10502,8 @@ static int devlink_netdevice_event(struct notifier_block *nb,
 		break;
 	case NETDEV_REGISTER:
 	case NETDEV_CHANGENAME:
+		if (devlink_net(devlink) != dev_net(netdev))
+			return NOTIFY_OK;
 		/* Set the netdev on top of previously set type. Note this
 		 * event happens also during net namespace change so here
 		 * we take into account netdev pointer appearing in this
@@ -10512,6 +10513,8 @@ static int devlink_netdevice_event(struct notifier_block *nb,
 					netdev);
 		break;
 	case NETDEV_UNREGISTER:
+		if (devlink_net(devlink) != dev_net(netdev))
+			return NOTIFY_OK;
 		/* Clear netdev pointer, but not the type. This event happens
 		 * also during net namespace change so we need to clear
 		 * pointer to netdev that is going to another net namespace.
-- 
2.39.0

Re: [patch net] devlink: change port event netdev notifier from per-net to global

[Jacob Keller]

On 2/6/2023 1:41 AM, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@nvidia.com>
> 
> Currently only the network namespace of devlink instance is monitored
> for port events. If netdev is moved to a different namespace and then
> unregistered, NETDEV_PRE_UNINIT is missed which leads to trigger
> following WARN_ON in devl_port_unregister().
> WARN_ON(devlink_port->type != DEVLINK_PORT_TYPE_NOTSET);
> 
> Fix this by changing the netdev notifier from per-net to global so no
> event is missed.
> 
> Fixes: 02a68a47eade ("net: devlink: track netdev with devlink_port assigned")
> Signed-off-by: Jiri Pirko <jiri@nvidia.com>

Seems reasonable.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>

Re: [patch net] devlink: change port event netdev notifier from per-net to global

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Paolo Abeni <pabeni@redhat.com>:

On Mon,  6 Feb 2023 10:41:51 +0100 you wrote:
> From: Jiri Pirko <jiri@nvidia.com>
> 
> Currently only the network namespace of devlink instance is monitored
> for port events. If netdev is moved to a different namespace and then
> unregistered, NETDEV_PRE_UNINIT is missed which leads to trigger
> following WARN_ON in devl_port_unregister().
> WARN_ON(devlink_port->type != DEVLINK_PORT_TYPE_NOTSET);
> 
> [...]

Here is the summary with links:
  - [net] devlink: change port event netdev notifier from per-net to global
    https://git.kernel.org/netdev/net/c/565b4824c39f

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [patch net] devlink: change port event netdev notifier from per-net to global

[Ido Schimmel]

On Mon, Feb 06, 2023 at 10:41:51AM +0100, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@nvidia.com>
> 
> Currently only the network namespace of devlink instance is monitored
> for port events. If netdev is moved to a different namespace and then
> unregistered, NETDEV_PRE_UNINIT is missed which leads to trigger
> following WARN_ON in devl_port_unregister().
> WARN_ON(devlink_port->type != DEVLINK_PORT_TYPE_NOTSET);
> 
> Fix this by changing the netdev notifier from per-net to global so no
> event is missed.
> 
> Fixes: 02a68a47eade ("net: devlink: track netdev with devlink_port assigned")
> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
> ---
>  net/core/devlink.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/net/core/devlink.c b/net/core/devlink.c
> index 032d6d0a5ce6..909a10e4b0dd 100644
> --- a/net/core/devlink.c
> +++ b/net/core/devlink.c
> @@ -9979,7 +9979,7 @@ struct devlink *devlink_alloc_ns(const struct devlink_ops *ops,
>  		goto err_xa_alloc;
>  
>  	devlink->netdevice_nb.notifier_call = devlink_netdevice_event;
> -	ret = register_netdevice_notifier_net(net, &devlink->netdevice_nb);
> +	ret = register_netdevice_notifier(&devlink->netdevice_nb);
>  	if (ret)
>  		goto err_register_netdevice_notifier;
>  
> @@ -10171,8 +10171,7 @@ void devlink_free(struct devlink *devlink)
>  	xa_destroy(&devlink->snapshot_ids);
>  	xa_destroy(&devlink->ports);
>  
> -	WARN_ON_ONCE(unregister_netdevice_notifier_net(devlink_net(devlink),
> -						       &devlink->netdevice_nb));
> +	WARN_ON_ONCE(unregister_netdevice_notifier(&devlink->netdevice_nb));
>  
>  	xa_erase(&devlinks, devlink->index);
>  
> @@ -10503,6 +10502,8 @@ static int devlink_netdevice_event(struct notifier_block *nb,
>  		break;
>  	case NETDEV_REGISTER:
>  	case NETDEV_CHANGENAME:
> +		if (devlink_net(devlink) != dev_net(netdev))
> +			return NOTIFY_OK;
>  		/* Set the netdev on top of previously set type. Note this
>  		 * event happens also during net namespace change so here
>  		 * we take into account netdev pointer appearing in this
> @@ -10512,6 +10513,8 @@ static int devlink_netdevice_event(struct notifier_block *nb,
>  					netdev);
>  		break;
>  	case NETDEV_UNREGISTER:
> +		if (devlink_net(devlink) != dev_net(netdev))
> +			return NOTIFY_OK;
>  		/* Clear netdev pointer, but not the type. This event happens
>  		 * also during net namespace change so we need to clear
>  		 * pointer to netdev that is going to another net namespace.

Since the notifier block is no longer registered per-netns it shouldn't
be moved to a different netns on reload. I'm testing the following diff
[1] against net-next (although it should be eventually submitted to
net).

[1]
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d9cdbc047b49..efbee940bb03 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2858,8 +2858,6 @@ int unregister_netdevice_notifier(struct notifier_block *nb);
 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb);
 int unregister_netdevice_notifier_net(struct net *net,
 				      struct notifier_block *nb);
-void move_netdevice_notifier_net(struct net *src_net, struct net *dst_net,
-				 struct notifier_block *nb);
 int register_netdevice_notifier_dev_net(struct net_device *dev,
 					struct notifier_block *nb,
 					struct netdev_net_notifier *nn);
diff --git a/net/core/dev.c b/net/core/dev.c
index 7307a0c15c9f..709b1a02820b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1870,14 +1870,6 @@ static void __move_netdevice_notifier_net(struct net *src_net,
 	__register_netdevice_notifier_net(dst_net, nb, true);
 }
 
-void move_netdevice_notifier_net(struct net *src_net, struct net *dst_net,
-				 struct notifier_block *nb)
-{
-	rtnl_lock();
-	__move_netdevice_notifier_net(src_net, dst_net, nb);
-	rtnl_unlock();
-}
-
 int register_netdevice_notifier_dev_net(struct net_device *dev,
 					struct notifier_block *nb,
 					struct netdev_net_notifier *nn)
diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index ab4e0f3c4e3d..c879c3c78e18 100644
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -343,8 +343,6 @@ static void devlink_reload_netns_change(struct devlink *devlink,
 	 * reload process so the notifications are generated separatelly.
 	 */
 	devlink_notify_unregister(devlink);
-	move_netdevice_notifier_net(curr_net, dest_net,
-				    &devlink->netdevice_nb);
 	write_pnet(&devlink->_net, dest_net);
 	devlink_notify_register(devlink);
 }

Re: [patch net] devlink: change port event netdev notifier from per-net to global

[Jiri Pirko]

Tue, Feb 14, 2023 at 09:41:36AM CET, idosch@idosch.org wrote:
>On Mon, Feb 06, 2023 at 10:41:51AM +0100, Jiri Pirko wrote:
>> From: Jiri Pirko <jiri@nvidia.com>
>> 
>> Currently only the network namespace of devlink instance is monitored
>> for port events. If netdev is moved to a different namespace and then
>> unregistered, NETDEV_PRE_UNINIT is missed which leads to trigger
>> following WARN_ON in devl_port_unregister().
>> WARN_ON(devlink_port->type != DEVLINK_PORT_TYPE_NOTSET);
>> 
>> Fix this by changing the netdev notifier from per-net to global so no
>> event is missed.
>> 
>> Fixes: 02a68a47eade ("net: devlink: track netdev with devlink_port assigned")
>> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
>> ---
>>  net/core/devlink.c | 9 ++++++---
>>  1 file changed, 6 insertions(+), 3 deletions(-)
>> 
>> diff --git a/net/core/devlink.c b/net/core/devlink.c
>> index 032d6d0a5ce6..909a10e4b0dd 100644
>> --- a/net/core/devlink.c
>> +++ b/net/core/devlink.c
>> @@ -9979,7 +9979,7 @@ struct devlink *devlink_alloc_ns(const struct devlink_ops *ops,
>>  		goto err_xa_alloc;
>>  
>>  	devlink->netdevice_nb.notifier_call = devlink_netdevice_event;
>> -	ret = register_netdevice_notifier_net(net, &devlink->netdevice_nb);
>> +	ret = register_netdevice_notifier(&devlink->netdevice_nb);
>>  	if (ret)
>>  		goto err_register_netdevice_notifier;
>>  
>> @@ -10171,8 +10171,7 @@ void devlink_free(struct devlink *devlink)
>>  	xa_destroy(&devlink->snapshot_ids);
>>  	xa_destroy(&devlink->ports);
>>  
>> -	WARN_ON_ONCE(unregister_netdevice_notifier_net(devlink_net(devlink),
>> -						       &devlink->netdevice_nb));
>> +	WARN_ON_ONCE(unregister_netdevice_notifier(&devlink->netdevice_nb));
>>  
>>  	xa_erase(&devlinks, devlink->index);
>>  
>> @@ -10503,6 +10502,8 @@ static int devlink_netdevice_event(struct notifier_block *nb,
>>  		break;
>>  	case NETDEV_REGISTER:
>>  	case NETDEV_CHANGENAME:
>> +		if (devlink_net(devlink) != dev_net(netdev))
>> +			return NOTIFY_OK;
>>  		/* Set the netdev on top of previously set type. Note this
>>  		 * event happens also during net namespace change so here
>>  		 * we take into account netdev pointer appearing in this
>> @@ -10512,6 +10513,8 @@ static int devlink_netdevice_event(struct notifier_block *nb,
>>  					netdev);
>>  		break;
>>  	case NETDEV_UNREGISTER:
>> +		if (devlink_net(devlink) != dev_net(netdev))
>> +			return NOTIFY_OK;
>>  		/* Clear netdev pointer, but not the type. This event happens
>>  		 * also during net namespace change so we need to clear
>>  		 * pointer to netdev that is going to another net namespace.
>
>Since the notifier block is no longer registered per-netns it shouldn't
>be moved to a different netns on reload. I'm testing the following diff
>[1] against net-next (although it should be eventually submitted to
>net).

Oh yeah. That is needed. Thanks!

>
>[1]
>diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>index d9cdbc047b49..efbee940bb03 100644
>--- a/include/linux/netdevice.h
>+++ b/include/linux/netdevice.h
>@@ -2858,8 +2858,6 @@ int unregister_netdevice_notifier(struct notifier_block *nb);
> int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb);
> int unregister_netdevice_notifier_net(struct net *net,
> 				      struct notifier_block *nb);
>-void move_netdevice_notifier_net(struct net *src_net, struct net *dst_net,
>-				 struct notifier_block *nb);
> int register_netdevice_notifier_dev_net(struct net_device *dev,
> 					struct notifier_block *nb,
> 					struct netdev_net_notifier *nn);
>diff --git a/net/core/dev.c b/net/core/dev.c
>index 7307a0c15c9f..709b1a02820b 100644
>--- a/net/core/dev.c
>+++ b/net/core/dev.c
>@@ -1870,14 +1870,6 @@ static void __move_netdevice_notifier_net(struct net *src_net,
> 	__register_netdevice_notifier_net(dst_net, nb, true);
> }
> 
>-void move_netdevice_notifier_net(struct net *src_net, struct net *dst_net,
>-				 struct notifier_block *nb)
>-{
>-	rtnl_lock();
>-	__move_netdevice_notifier_net(src_net, dst_net, nb);
>-	rtnl_unlock();
>-}
>-
> int register_netdevice_notifier_dev_net(struct net_device *dev,
> 					struct notifier_block *nb,
> 					struct netdev_net_notifier *nn)
>diff --git a/net/devlink/dev.c b/net/devlink/dev.c
>index ab4e0f3c4e3d..c879c3c78e18 100644
>--- a/net/devlink/dev.c
>+++ b/net/devlink/dev.c
>@@ -343,8 +343,6 @@ static void devlink_reload_netns_change(struct devlink *devlink,
> 	 * reload process so the notifications are generated separatelly.
> 	 */
> 	devlink_notify_unregister(devlink);
>-	move_netdevice_notifier_net(curr_net, dest_net,
>-				    &devlink->netdevice_nb);
> 	write_pnet(&devlink->_net, dest_net);
> 	devlink_notify_register(devlink);
> }