Re: [PATCH net v2 3/3] net/mlx5: Bridge, don't fail unlink of untracked/unsupported peer ports

[Mark Bloch <mbloch@nvidia.com>]

On 14/09/2026 11:54, Bernardo Soares wrote:
> mlx5_esw_bridge_vport_unlink() returns -EINVAL when the port isn't
> tracked by this instance's br_offloads, which is reachable in two
> legitimate cases: a replayed/duplicate NETDEV_CHANGEUPPER unlink for a
> port already cleaned up, or a peer-port unlink for a vport whose link
> was never created because peer_link() skipped it. Return 0 instead in
> both cases, and give mlx5_esw_bridge_vport_peer_unlink() the same
> merged_eswitch capability guard peer_link() already has.
> 
> 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 skip the global chain
> entirely - so the old -EINVAL silently dropped the event for every
> other listener on the system, including a sibling PF's own
> bridge-offload instance, 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 <bersoare@isovalent.com>

Commit message nit: NETDEV_CHANGEUPPER is not replayed, and
only listeners later in the chain are skipped. The code looks
good.

checkpatch warns the From address is gmail while the signed-off-by
uses the Isovalent address. Please make them match.
v2 was sent as a reply to v1. Please send v3 as a new thread.


Mark

> ---
> v2: new patch, addresses review comment on v1 asking whether the peer
>     unlink path also needed changes. mlx5_esw_bridge_vport_peer_unlink()
>     now mirrors mlx5_esw_bridge_vport_peer_link()'s merged_eswitch
>     capability guard, and mlx5_esw_bridge_vport_unlink() treats an
>     already-absent/untracked port as a no-op (return 0) instead of
>     -EINVAL, which is reachable on a replayed or duplicate
>     NETDEV_CHANGEUPPER unlink and was found while auditing the same
>     code for the ownership-check gap raised on v1.
> ---
> 
>  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);
>  }