[PATCH 4.19 078/114] bonding: fix active-backup transition after link failure

From: Greg Kroah-Hartman
Date: Thu Jan 02 2020 - 17:52:41 EST

From: Mahesh Bandewar <maheshb@xxxxxxxxxx>

[ Upstream commit 5d485ed88d48f8101a2067348e267c0aaf4ed486 ]

After the recent fix in commit 1899bb325149 ("bonding: fix state
transition issue in link monitoring"), the active-backup mode with
miimon initially come-up fine but after a link-failure, both members
transition into backup state.

Following steps to reproduce the scenario (eth1 and eth2 are the
slaves of the bond):

ip link set eth1 up
ip link set eth2 down
sleep 1
ip link set eth2 up
ip link set eth1 down
cat /sys/class/net/eth1/bonding_slave/state
cat /sys/class/net/eth2/bonding_slave/state

Fixes: 1899bb325149 ("bonding: fix state transition issue in link monitoring")
CC: Jay Vosburgh <jay.vosburgh@xxxxxxxxxxxxx>
Signed-off-by: Mahesh Bandewar <maheshb@xxxxxxxxxx>
Acked-by: Jay Vosburgh <jay.vosburgh@xxxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/net/bonding/bond_main.c | 3 ---
1 file changed, 3 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 9b8143dca512..f57b86f1373d 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2223,9 +2223,6 @@ static void bond_miimon_commit(struct bonding *bond)
/* make it immediately active */
- } else if (slave != primary) {
- /* prevent it from being the active one */
- bond_set_backup_slave(slave);

netdev_info(bond->dev, "link status definitely up for interface %s, %u Mbps %s duplex\n",