On Wed, 2 Dec 2020 12:30:53 -0500
Jarod Wilson <ja...@redhat.com> wrote:
> Don't try to adjust XFRM support flags if the bond device isn't yet
> registered. Bad things can currently happen when netdev_change_features()
> is called without having wanted_features fully filled in yet. Basically,
> this code was racing against register_netdevice() filling in
> wanted_features, and when it got there first, the empty wanted_features
> led to features also getting emptied out, which was definitely not the
> intended behavior, so prevent that from happening.
>
> Originally, I'd hoped to stop adjusting wanted_features at all in the
> bonding driver, as it's documented as being something only the network
> core should touch, but we actually do need to do this to properly update
> both the features and wanted_features fields when changing the bond type,
> or we get to a situation where ethtool sees:
>
> esp-hw-offload: off [requested on]
>
> I do think we should be using netdev_update_features instead of
> netdev_change_features here though, so we only send notifiers when the
> features actually changed.
>
> v2: rework based on further testing and suggestions from ivecera
>
> Fixes: a3b658cfb664 ("bonding: allow xfrm offload setup post-module-load")
> Reported-by: Ivan Vecera <ivec...@redhat.com>
> Suggested-by: Ivan Vecera <ivec...@redhat.com>
> Cc: Jay Vosburgh <j.vosbu...@gmail.com>
> Cc: Veaceslav Falico <vfal...@gmail.com>
> Cc: Andy Gospodarek <a...@greyhouse.net>
> Cc: "David S. Miller" <da...@davemloft.net>
> Cc: Jakub Kicinski <k...@kernel.org>
> Cc: Thomas Davis <tada...@lbl.gov>
> Cc: netdev@vger.kernel.org
> Signed-off-by: Jarod Wilson <ja...@redhat.com>
> ---
> drivers/net/bonding/bond_main.c | 10 ++++------
> drivers/net/bonding/bond_options.c | 6 +++++-
> 2 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index e0880a3840d7..5fe5232cc3f3 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -4746,15 +4746,13 @@ void bond_setup(struct net_device *bond_dev)
> NETIF_F_HW_VLAN_CTAG_FILTER;
>
> bond_dev->hw_features |= NETIF_F_GSO_ENCAP_ALL;
> -#ifdef CONFIG_XFRM_OFFLOAD
> - bond_dev->hw_features |= BOND_XFRM_FEATURES;
> -#endif /* CONFIG_XFRM_OFFLOAD */
> bond_dev->features |= bond_dev->hw_features;
> bond_dev->features |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
> #ifdef CONFIG_XFRM_OFFLOAD
> - /* Disable XFRM features if this isn't an active-backup config */
> - if (BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP)
> - bond_dev->features &= ~BOND_XFRM_FEATURES;
> + bond_dev->hw_features |= BOND_XFRM_FEATURES;
> + /* Only enable XFRM features if this is an active-backup config */
> + if (BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP)
> + bond_dev->features |= BOND_XFRM_FEATURES;
> #endif /* CONFIG_XFRM_OFFLOAD */
> }
>
> diff --git a/drivers/net/bonding/bond_options.c
> b/drivers/net/bonding/bond_options.c
> index 9abfaae1c6f7..19205cfac751 100644
> --- a/drivers/net/bonding/bond_options.c
> +++ b/drivers/net/bonding/bond_options.c
> @@ -768,11 +768,15 @@ static int bond_option_mode_set(struct bonding *bond,
> bond->params.tlb_dynamic_lb = 1;
>
> #ifdef CONFIG_XFRM_OFFLOAD
> + if (bond->dev->reg_state != NETREG_REGISTERED)
> + goto noreg;
> +
> if (newval->value == BOND_MODE_ACTIVEBACKUP)
> bond->dev->wanted_features |= BOND_XFRM_FEATURES;
> else
> bond->dev->wanted_features &= ~BOND_XFRM_FEATURES;
> - netdev_change_features(bond->dev);
> + netdev_update_features(bond->dev);
> +noreg:
> #endif /* CONFIG_XFRM_OFFLOAD */
>
> /* don't cache arp_validate between modes */
Tested-by: Ivan Vecera <ivec...@redhat.com>
