Re: [PATCH v4 net-next 1/3] net: dsa: track whetever bridges have foreign interfaces in them

[Vladimir Oltean <olteanv@gmail.com>]

On Mon, Apr 11, 2022 at 02:06:31PM +0200, Mattias Forsblad wrote:
> Track if a bridge stack has any foreign interfaces in them.
> 
> This patch is based on work done by Vlodimir Oltean.

Originally these were 2 patches which were squashed (and they were 2
patches for a reason), they're missing proper authorship (mine, my sign
off, your sign off), and my name is misspelled.

> 
> Signed-off-by: Mattias Forsblad <mattias.forsblad@gmail.com>
> ---
>  include/net/dsa.h  |  1 +
>  net/dsa/dsa_priv.h |  1 +
>  net/dsa/slave.c    | 88 +++++++++++++++++++++++++++++++++++++++++-----
>  3 files changed, 81 insertions(+), 9 deletions(-)
> 
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index 934958fda962..52b6da7d45b3 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -242,6 +242,7 @@ struct dsa_bridge {
>  	unsigned int num;
>  	bool tx_fwd_offload;
>  	refcount_t refcount;
> +	u8 have_foreign:1;
>  };
>  
>  struct dsa_port {
> diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
> index 5d3f4a67dce1..d610776ecd76 100644
> --- a/net/dsa/dsa_priv.h
> +++ b/net/dsa/dsa_priv.h
> @@ -320,6 +320,7 @@ void dsa_slave_setup_tagger(struct net_device *slave);
>  int dsa_slave_change_mtu(struct net_device *dev, int new_mtu);
>  int dsa_slave_manage_vlan_filtering(struct net_device *dev,
>  				    bool vlan_filtering);
> +int dsa_bridge_foreign_dev_update(struct net_device *bridge_dev);
>  
>  static inline struct dsa_port *dsa_slave_to_port(const struct net_device *dev)
>  {
> diff --git a/net/dsa/slave.c b/net/dsa/slave.c
> index 41c69a6e7854..feaf64564c6e 100644
> --- a/net/dsa/slave.c
> +++ b/net/dsa/slave.c
> @@ -2485,6 +2485,9 @@ static int dsa_slave_changeupper(struct net_device *dev,
>  	struct netlink_ext_ack *extack;
>  	int err = NOTIFY_DONE;
>  
> +	if (!dsa_slave_dev_check(dev))
> +		return err;
> +
>  	extack = netdev_notifier_info_to_extack(&info->info);
>  
>  	if (netif_is_bridge_master(info->upper_dev)) {
> @@ -2539,6 +2542,9 @@ static int dsa_slave_prechangeupper(struct net_device *dev,
>  {
>  	struct dsa_port *dp = dsa_slave_to_port(dev);
>  
> +	if (!dsa_slave_dev_check(dev))
> +		return NOTIFY_DONE;
> +
>  	if (netif_is_bridge_master(info->upper_dev) && !info->linking)
>  		dsa_port_pre_bridge_leave(dp, info->upper_dev);
>  	else if (netif_is_lag_master(info->upper_dev) && !info->linking)
> @@ -2559,6 +2565,9 @@ dsa_slave_lag_changeupper(struct net_device *dev,
>  	int err = NOTIFY_DONE;
>  	struct dsa_port *dp;
>  
> +	if (!netif_is_lag_master(dev))
> +		return err;
> +
>  	netdev_for_each_lower_dev(dev, lower, iter) {
>  		if (!dsa_slave_dev_check(lower))
>  			continue;
> @@ -2588,6 +2597,9 @@ dsa_slave_lag_prechangeupper(struct net_device *dev,
>  	int err = NOTIFY_DONE;
>  	struct dsa_port *dp;
>  
> +	if (!netif_is_lag_master(dev))
> +		return err;
> +
>  	netdev_for_each_lower_dev(dev, lower, iter) {
>  		if (!dsa_slave_dev_check(lower))
>  			continue;
> @@ -2605,6 +2617,18 @@ dsa_slave_lag_prechangeupper(struct net_device *dev,
>  	return err;
>  }
>  
> +static int dsa_bridge_changelower(struct net_device *dev,
> +				  struct netdev_notifier_changeupper_info *info)
> +{
> +	int err;
> +
> +	if (!netif_is_bridge_master(info->upper_dev))
> +		return NOTIFY_DONE;
> +
> +	err = dsa_bridge_foreign_dev_update(info->upper_dev);
> +	return notifier_from_errno(err);
> +}
> +
>  static int
>  dsa_prevent_bridging_8021q_upper(struct net_device *dev,
>  				 struct netdev_notifier_changeupper_info *info)
> @@ -2709,22 +2733,33 @@ static int dsa_slave_netdevice_event(struct notifier_block *nb,
>  		if (err != NOTIFY_DONE)
>  			return err;
>  
> -		if (dsa_slave_dev_check(dev))
> -			return dsa_slave_prechangeupper(dev, ptr);
> +		err = dsa_slave_prechangeupper(dev, ptr);
> +		if (notifier_to_errno(err))
> +			return err;
>  
> -		if (netif_is_lag_master(dev))
> -			return dsa_slave_lag_prechangeupper(dev, ptr);
> +		err = dsa_slave_lag_prechangeupper(dev, ptr);
> +		if (notifier_to_errno(err))
> +			return err;
>  
>  		break;
>  	}
> -	case NETDEV_CHANGEUPPER:
> -		if (dsa_slave_dev_check(dev))
> -			return dsa_slave_changeupper(dev, ptr);
> +	case NETDEV_CHANGEUPPER: {
> +		int err;
>  
> -		if (netif_is_lag_master(dev))
> -			return dsa_slave_lag_changeupper(dev, ptr);
> +		err = dsa_slave_changeupper(dev, ptr);
> +		if (notifier_to_errno(err))
> +			return err;
> +
> +		err = dsa_slave_lag_changeupper(dev, ptr);
> +		if (notifier_to_errno(err))
> +			return err;
> +
> +		err = dsa_bridge_changelower(dev, ptr);
> +		if (notifier_to_errno(err))
> +			return err;
>  
>  		break;
> +	}
>  	case NETDEV_CHANGELOWERSTATE: {
>  		struct netdev_notifier_changelowerstate_info *info = ptr;
>  		struct dsa_port *dp;
> @@ -2877,6 +2912,41 @@ static bool dsa_foreign_dev_check(const struct net_device *dev,
>  	return true;
>  }
>  
> +int dsa_bridge_foreign_dev_update(struct net_device *bridge_dev)
> +{
> +	struct net_device *first_slave, *lower;
> +	struct dsa_bridge *bridge = NULL;
> +	struct dsa_switch_tree *dst;
> +	bool have_foreign = false;
> +	struct list_head *iter;
> +	struct dsa_port *dp;
> +
> +	list_for_each_entry(dst, &dsa_tree_list, list) {
> +		dsa_tree_for_each_user_port(dp, dst) {
> +			if (dsa_port_offloads_bridge_dev(dp, bridge_dev)) {
> +				bridge = dp->bridge;
> +				first_slave = dp->slave;
> +				break;
> +			}
> +		}
> +	}
> +
> +	/* Bridge with no DSA interface in it */
> +	if (!bridge)
> +		return 0;
> +
> +	netdev_for_each_lower_dev(bridge_dev, lower, iter) {
> +		if (dsa_foreign_dev_check(first_slave, lower)) {
> +			have_foreign = true;
> +			break;
> +		}
> +	}
> +
> +	bridge->have_foreign = have_foreign;
> +
> +	return 0;
> +}
> +
>  static int dsa_slave_fdb_event(struct net_device *dev,
>  			       struct net_device *orig_dev,
>  			       unsigned long event, const void *ctx,
> -- 
> 2.25.1
>