Re: [PATCH net v4 2/2] net/mlx5: Bridge, don't fail unlink of untracked/unsupported peer ports

[Mark Bloch <mbloch@nvidia.com>]

On 18/09/2026 12:59, Bernardo Soares wrote:
> mlx5_esw_bridge_vport_unlink() returns -EINVAL when the port isn't
> tracked by this instance's br_offloads. This is reachable on a sibling
> instance that registered its notifier after the port was already
> enslaved: it never saw the NETDEV_CHANGEUPPER link event, so
> peer_link() never created a peer port for it, but it does see the
> later unlink event and fails. Return 0 instead, and give
> mlx5_esw_bridge_vport_peer_unlink() the same merged_eswitch capability
> guard peer_link() already has, since without it peer_link() likewise
> never creates a port to unlink.
> 
> This also matters beyond the -EINVAL itself:
> mlx5_esw_bridge_switchdev_port_event() runs on the per-netns
> netdev_chain, and notifier_from_errno(-EINVAL) sets NOTIFY_STOP_MASK,
> which call_netdevice_notifiers_info() checks to stop calling further
> listeners on that chain - so the old -EINVAL silently dropped the
> event for any listener registered later on the same chain, even
> though none of it was visible to user space since
> __netdev_upper_dev_unlink() discards the return value.
> 
> Fixes: c358ea1741bc ("net/mlx5: Bridge, allow merged eswitch connectivity")
> Signed-off-by: Bernardo Soares <bsoares.it@gmail.com>

Thanks,

Reviewed-by: Mark Bloch <mbloch@nvidia.com>

Mark

> ---
>  drivers/net/ethernet/mellanox/mlx5/core/esw/bridge.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/bridge.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/bridge.c
> index ac90ccda1272..b4cf3c5ac0dd 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/esw/bridge.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/bridge.c
> @@ -1649,10 +1649,8 @@ int mlx5_esw_bridge_vport_unlink(struct net_device *br_netdev, u16 vport_num,
>  	int err;
>  
>  	port = mlx5_esw_bridge_port_lookup(vport_num, esw_owner_vhca_id, br_offloads);
> -	if (!port) {
> -		NL_SET_ERR_MSG_MOD(extack, "Port is not attached to any bridge");
> -		return -EINVAL;
> -	}
> +	if (!port)
> +		return 0;
>  	if (port->bridge->ifindex != br_netdev->ifindex) {
>  		NL_SET_ERR_MSG_MOD(extack, "Port is attached to another bridge");
>  		return -EINVAL;
> @@ -1682,6 +1680,9 @@ int mlx5_esw_bridge_vport_peer_unlink(struct net_device *br_netdev, u16 vport_nu
>  				      struct mlx5_esw_bridge_offloads *br_offloads,
>  				      struct netlink_ext_ack *extack)
>  {
> +	if (!MLX5_CAP_ESW(br_offloads->esw->dev, merged_eswitch))
> +		return 0;
> +
>  	return mlx5_esw_bridge_vport_unlink(br_netdev, vport_num, esw_owner_vhca_id, br_offloads,
>  					    extack);
>  }