[PATCH] net: bonding: do not set force_primary if reselect is set to failure

From: Suresh Kumar
Date: Thu Sep 12 2024 - 02:44:16 EST


when bond_enslave() is called, it sets bond->force_primary to true
without checking if primary_reselect is set to 'failure' or 'better'.
This can result in primary becoming active again when link is back which
is not what we want when primary_reselect is set to 'failure'

Test
====
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: enp1s0 (primary_reselect failure)
Currently Active Slave: enp1s0
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0
Peer Notification Delay (ms): 0

Slave Interface: enp1s0
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 52:54:00:d7:a7:2a
Slave queue ID: 0

Slave Interface: enp9s0
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 52:54:00:da:9a:f9
Slave queue ID: 0


After primary link failure:

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: None
Currently Active Slave: enp9s0 <---- secondary is active now
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0
Peer Notification Delay (ms): 0

Slave Interface: enp9s0
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 52:54:00:da:9a:f9
Slave queue ID: 0


Now add primary link back and check bond status:

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: enp1s0 (primary_reselect failure)
Currently Active Slave: enp1s0 <------------- primary is active again
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0
Peer Notification Delay (ms): 0

Slave Interface: enp9s0
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 52:54:00:da:9a:f9
Slave queue ID: 0

Slave Interface: enp1s0
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 52:54:00:d7:a7:2a
Slave queue ID: 0

Signed-off-by: Suresh Kumar <suresh2514@xxxxxxxxx>
---
drivers/net/bonding/bond_main.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index bb9c3d6ef435..731256fbb996 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2146,7 +2146,9 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
/* if there is a primary slave, remember it */
if (strcmp(bond->params.primary, new_slave->dev->name) == 0) {
rcu_assign_pointer(bond->primary_slave, new_slave);
- bond->force_primary = true;
+ if (bond->params.primary_reselect != BOND_PRI_RESELECT_FAILURE &&
+ bond->params.primary_reselect != BOND_PRI_RESELECT_BETTER)
+ bond->force_primary = true;
}
}

--
2.43.0