Re: [Patch net-next v2] hv_netvsc: Set device flags for properly indicating bonding in Hyper-V
From: Jakub Kicinski
Date: Mon Dec 16 2024 - 21:03:17 EST
On Fri, 13 Dec 2024 12:06:01 -0800 longli@xxxxxxxxxxxxxxxxx wrote:
> Other kernel APIs (e.g those in "include/linux/netdevice.h") check for
> IFF_MASTER, IFF_SLAVE and IFF_BONDING for determing if those are used
> in a master/slave bonded setup. RDMA uses those APIs extensively when
> looking for master/slave devices. Netvsc's bonding setup with its slave
> device falls into this category.
>
> Make hv_netvsc properly indicate bonding with its slave and change the
> API to reflect this bonding setup.
This is severely lacking in terms of safety analysis.
> @@ -2204,6 +2204,10 @@ static int netvsc_vf_join(struct net_device *vf_netdev,
> goto rx_handler_failed;
> }
>
> + vf_netdev->permanent_bond = 1;
> + ndev->permanent_bond = 1;
> + ndev->flags |= IFF_MASTER;
> @@ -2484,7 +2488,15 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev)
>
> reinit_completion(&net_device_ctx->vf_add);
> netdev_rx_handler_unregister(vf_netdev);
> +
> + /* Unlink the slave device and clear flag */
> + vf_netdev->permanent_bond = 0;
> + ndev->permanent_bond = 0;
> + * @permanent_bond: device is permanently bonded to another device
I think we have been taught a definition of the word "permanent"