On Wed, 2 Dec 2020 19:43:57 -0500 Jarod Wilson 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. This code
> runs on post-module-load mode changes, as well as at module init time
> and new bond creation time, and in the latter two scenarios, it is
> running prior to register_netdevice() having been called and
> subsequently filling in wanted_features. 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
> v3: add helper function, remove goto, fix problem description
>
> 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: net...@vger.kernel.org
> Signed-off-by: Jarod Wilson <ja...@redhat.com>
> ---
> drivers/net/bonding/bond_main.c | 10 ++++------
> drivers/net/bonding/bond_options.c | 19 ++++++++++++++-----
> 2 files changed, 18 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 47afc5938c26..7905534a763b 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -4747,15 +4747,13 @@ void bond_setup(struct net_device *bond_dev)
> NETIF_F_HW_VLAN_CTAG_FILTER;
>
> bond_dev->hw_features |= NETIF_F_GSO_ENCAP_ALL | NETIF_F_GSO_UDP_L4;
> -#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..1ae0e5ab8c67 100644
> --- a/drivers/net/bonding/bond_options.c
> +++ b/drivers/net/bonding/bond_options.c
> @@ -745,6 +745,18 @@ const struct bond_option *bond_opt_get(unsigned int
> option)
> return &bond_opts[option];
> }
>
> +#ifdef CONFIG_XFRM_OFFLOAD
> +static void bond_set_xfrm_features(struct net_device *bond_dev, u64 mode)
> +{
> + if (mode == BOND_MODE_ACTIVEBACKUP)
> + bond_dev->wanted_features |= BOND_XFRM_FEATURES;
> + else
> + bond_dev->wanted_features &= ~BOND_XFRM_FEATURES;
> +
> + netdev_update_features(bond_dev);
> +}
> +#endif /* CONFIG_XFRM_OFFLOAD */
> +
> static int bond_option_mode_set(struct bonding *bond,
> const struct bond_opt_value *newval)
> {
> @@ -768,11 +780,8 @@ static int bond_option_mode_set(struct bonding *bond,
> bond->params.tlb_dynamic_lb = 1;
>
> #ifdef CONFIG_XFRM_OFFLOAD
> - 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);
> + if (bond->dev->reg_state == NETREG_REGISTERED)
> + bond_set_xfrm_features(bond->dev, newval->value);
> #endif /* CONFIG_XFRM_OFFLOAD */
nit: let's narrow down the ifdef-enery
no need for the ifdef here, if the helper looks like this:
+static void bond_set_xfrm_features(struct net_device *bond_dev, u64 mode)
+{
+#ifdef CONFIG_XFRM_OFFLOAD
+ if (mode == BOND_MODE_ACTIVEBACKUP)
+ bond_dev->wanted_features |= BOND_XFRM_FEATURES;
+ else
+ bond_dev->wanted_features &= ~BOND_XFRM_FEATURES;
+
+ netdev_update_features(bond_dev);
+#endif /* CONFIG_XFRM_OFFLOAD */
+}
Even better:
+static void bond_set_xfrm_features(struct net_device *bond_dev, u64 mode)
+{
+ if (!IS_ENABLED(CONFIG_XFRM_OFFLOAD))
+ return;
+
+ if (mode == BOND_MODE_ACTIVEBACKUP)
+ bond_dev->wanted_features |= BOND_XFRM_FEATURES;
+ else
+ bond_dev->wanted_features &= ~BOND_XFRM_FEATURES;
+
+ netdev_update_features(bond_dev);
+}
(Assuming BOND_XFRM_FEATURES doesn't itself hide under an ifdef.)
>
> /* don't cache arp_validate between modes */
