[PATCH net 4/4] bonding: fix xfrm state handling when clearing active slave

[Nikolay Aleksandrov <razor@blackwall.org>]

If the active slave is cleared manually the xfrm state is not flushed.
This leads to xfrm add/del imbalance and adding the same state multiple
times. For example when the device cannot handle anymore states we get:
 [ 1169.884811] bond0: (slave eni0np1): bond_ipsec_add_sa_all: failed to add SA
because it's filled with the same state after multiple active slave
clearings. This change also has a few nice side effects: user-space
gets a notification for the change, the old device gets its mac address
and promisc/mcast adjusted properly.

Fixes: 18cb261afd7b ("bonding: support hardware encryption offload to slaves")
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
Please review this one more carefully. I plan to add a selftest with
netdevsim for this as well.

 drivers/net/bonding/bond_options.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index bc80fb6397dc..95d59a18c022 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -936,7 +936,7 @@ static int bond_option_active_slave_set(struct bonding *bond,
 	/* check to see if we are clearing active */
 	if (!slave_dev) {
 		netdev_dbg(bond->dev, "Clearing current active slave\n");
-		RCU_INIT_POINTER(bond->curr_active_slave, NULL);
+		bond_change_active_slave(bond, NULL);
 		bond_select_active_slave(bond);
 	} else {
 		struct slave *old_active = rtnl_dereference(bond->curr_active_slave);
-- 
2.44.0