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

[Suresh Kumar <suresh2514@gmail.com>]

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@gmail.com>
---
 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