diff options
authordingtianhong <dingtianhong@huawei.com>2015-07-16 16:30:02 +0800
committerBen Hutchings <ben@decadent.org.uk>2015-10-13 03:46:12 +0100
commitd2e030979b01b6f5e9785199cc982efad980e122 (patch)
parentc1a7dedbcb0b60ecbcda0d2398ad5d2b078c9f47 (diff)
bonding: correct the MAC address for "follow" fail_over_mac policy
[ Upstream commit a951bc1e6ba58f11df5ed5ddc41311e10f5fd20b ] The "follow" fail_over_mac policy is useful for multiport devices that either become confused or incur a performance penalty when multiple ports are programmed with the same MAC address, but the same MAC address still may happened by this steps for this policy: 1) echo +eth0 > /sys/class/net/bond0/bonding/slaves bond0 has the same mac address with eth0, it is MAC1. 2) echo +eth1 > /sys/class/net/bond0/bonding/slaves eth1 is backup, eth1 has MAC2. 3) ifconfig eth0 down eth1 became active slave, bond will swap MAC for eth0 and eth1, so eth1 has MAC1, and eth0 has MAC2. 4) ifconfig eth1 down there is no active slave, and eth1 still has MAC1, eth2 has MAC2. 5) ifconfig eth0 up the eth0 became active slave again, the bond set eth0 to MAC1. Something wrong here, then if you set eth1 up, the eth0 and eth1 will have the same MAC address, it will break this policy for ACTIVE_BACKUP mode. This patch will fix this problem by finding the old active slave and swap them MAC address before change active slave. Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> Tested-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - bond_for_each_slave() takes an extra int paramter - Use compare_ether_addr() instead of ether_addr_equal()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 5af2a8f..9145834c 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -861,6 +861,23 @@ static void bond_mc_swap(struct bonding *bond, struct slave *new_active,
+static struct slave *bond_get_old_active(struct bonding *bond,
+ struct slave *new_active)
+ struct slave *slave;
+ int i;
+ bond_for_each_slave(bond, slave, i) {
+ if (slave == new_active)
+ continue;
+ if (!compare_ether_addr(bond->dev->dev_addr, slave->dev->dev_addr))
+ return slave;
+ }
+ return NULL;
* bond_do_fail_over_mac
@@ -898,6 +915,9 @@ static void bond_do_fail_over_mac(struct bonding *bond,
+ if (!old_active)
+ old_active = bond_get_old_active(bond, new_active);
if (old_active) {
memcpy(tmp_mac, new_active->dev->dev_addr, ETH_ALEN);
memcpy(saddr.sa_data, old_active->dev->dev_addr,