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.
Is this an actual race? Reading Ivan's prior message, it sounds
like it's an ordering problem (in that bond_newlink calls
register_netdevice after bond_changelink).
The change to bond_option_mode_set tests against reg_state, so
presumably it wants to skip the first(?) time through, before the
register_netdevice call; is that right?
-J
>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: 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 | 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 */
>--
>2.28.0
>
---
-Jay Vosburgh, jay.vosbu...@canonical.com
