Re: [patch net-next v2 04/19] net: switchdev: Change notifier chain to be atomic

[Ivan Vecera <ivecera@redhat.com>]

On 8.6.2017 08:44, Jiri Pirko wrote:
> From: Arkadi Sharshevsky <arkadis@mellanox.com>
> 
> In order to use the switchdev notifier chain for FDB sync with the
> device it has to be changed to atomic. The is done because the bridge
> can learn new FDBs in atomic context.
> 
> Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
> Reviewed-by: Ido Schimmel <idosch@mellanox.com>
> Reviewed-by: Ivan Vecera <ivecera@redhat.com>
> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
> ---
>  net/switchdev/switchdev.c | 30 ++++++------------------------
>  1 file changed, 6 insertions(+), 24 deletions(-)
> 
> diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
> index 8d40a7d..25dc67e 100644
> --- a/net/switchdev/switchdev.c
> +++ b/net/switchdev/switchdev.c
> @@ -571,24 +571,17 @@ int switchdev_port_obj_dump(struct net_device *dev, struct switchdev_obj *obj,
>  }
>  EXPORT_SYMBOL_GPL(switchdev_port_obj_dump);
>  
> -static RAW_NOTIFIER_HEAD(switchdev_notif_chain);
> +static ATOMIC_NOTIFIER_HEAD(switchdev_notif_chain);
>  
>  /**
>   *	register_switchdev_notifier - Register notifier
>   *	@nb: notifier_block
>   *
> - *	Register switch device notifier. This should be used by code
> - *	which needs to monitor events happening in particular device.
> - *	Return values are same as for atomic_notifier_chain_register().
> + *	Register switch device notifier.
>   */
>  int register_switchdev_notifier(struct notifier_block *nb)
>  {
> -	int err;
> -
> -	rtnl_lock();
> -	err = raw_notifier_chain_register(&switchdev_notif_chain, nb);
> -	rtnl_unlock();
> -	return err;
> +	return atomic_notifier_chain_register(&switchdev_notif_chain, nb);
>  }
>  EXPORT_SYMBOL_GPL(register_switchdev_notifier);
>  
> @@ -597,16 +590,10 @@ EXPORT_SYMBOL_GPL(register_switchdev_notifier);
>   *	@nb: notifier_block
>   *
>   *	Unregister switch device notifier.
> - *	Return values are same as for atomic_notifier_chain_unregister().
>   */
>  int unregister_switchdev_notifier(struct notifier_block *nb)
>  {
> -	int err;
> -
> -	rtnl_lock();
> -	err = raw_notifier_chain_unregister(&switchdev_notif_chain, nb);
> -	rtnl_unlock();
> -	return err;
> +	return atomic_notifier_chain_unregister(&switchdev_notif_chain, nb);
>  }
>  EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);
>  
> @@ -616,18 +603,13 @@ EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);
>   *	@dev: port device
>   *	@info: notifier information data
>   *
> - *	Call all network notifier blocks. This should be called by driver
> - *	when it needs to propagate hardware event.
> - *	Return values are same as for atomic_notifier_call_chain().
> - *	rtnl_lock must be held.
> + *	Call all network notifier blocks.
>   */
>  int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
>  			     struct switchdev_notifier_info *info)
>  {
> -	ASSERT_RTNL();
> -
>  	info->dev = dev;
> -	return raw_notifier_call_chain(&switchdev_notif_chain, val, info);
> +	return atomic_notifier_call_chain(&switchdev_notif_chain, val, info);
>  }
>  EXPORT_SYMBOL_GPL(call_switchdev_notifiers);
>  
> 

Reviewed-by: Ivan Vecera <ivecera@redhat.com>