4.17-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jarod Wilson jarod@redhat.com
[ Upstream commit c1f897ce186a529a494441642125479d38727a3d ]
For some time now, if you load the bonding driver and configure bond parameters via sysfs using minimal config options, such as specifying nothing but the mode, relying on defaults for everything else, modes that cannot use arp monitoring (802.3ad, balance-tlb, balance-alb) all wind up with both arp_interval=0 (as it should be) and miimon=0, which means the miimon monitor thread never actually runs. This is particularly problematic for 802.3ad.
For example, from an LNST recipe I've set up:
$ modprobe bonding max_bonds=0" $ echo "+t_bond0" > /sys/class/net/bonding_masters" $ ip link set t_bond0 down" $ echo "802.3ad" > /sys/class/net/t_bond0/bonding/mode" $ ip link set ens1f1 down" $ echo "+ens1f1" > /sys/class/net/t_bond0/bonding/slaves" $ ip link set ens1f0 down" $ echo "+ens1f0" > /sys/class/net/t_bond0/bonding/slaves" $ ethtool -i t_bond0" $ ip link set ens1f1 up" $ ip link set ens1f0 up" $ ip link set t_bond0 up" $ ip addr add 192.168.9.1/24 dev t_bond0" $ ip addr add 2002::1/64 dev t_bond0"
This bond comes up okay, but things look slightly suspect in /proc/net/bonding/t_bond0 output:
$ grep -i mii /proc/net/bonding/t_bond0 MII Status: up MII Polling Interval (ms): 0 MII Status: up MII Status: up
Now, pull a cable on one of the ports in the bond, then reconnect it, and you'll see:
Slave Interface: ens1f0 MII Status: down Speed: 1000 Mbps Duplex: full
I believe this became a major issue as of commit 4d2c0cda0744, which for 802.3ad bonds, sets slave->link = BOND_LINK_DOWN, with a comment about relying on link monitoring via miimon to set it correctly, but since the miimon work queue never runs, the link just stays marked down.
If we simply tweak bond_option_mode_set() slightly, we can check for the non-arp modes having no miimon value set, and insert BOND_DEFAULT_MIIMON, which gets things back in full working order. This problem exists as far back as 4.14, and might be worth fixing in all stable trees since, though the work-around is to simply specify an miimon value yourself.
Reported-by: Bob Ball ball@umich.edu Signed-off-by: Jarod Wilson jarod@redhat.com Acked-by: Mahesh Bandewar maheshb@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/bonding/bond_options.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-)
--- a/drivers/net/bonding/bond_options.c +++ b/drivers/net/bonding/bond_options.c @@ -743,15 +743,20 @@ const struct bond_option *bond_opt_get(u static int bond_option_mode_set(struct bonding *bond, const struct bond_opt_value *newval) { - if (!bond_mode_uses_arp(newval->value) && bond->params.arp_interval) { - netdev_dbg(bond->dev, "%s mode is incompatible with arp monitoring, start mii monitoring\n", - newval->string); - /* disable arp monitoring */ - bond->params.arp_interval = 0; - /* set miimon to default value */ - bond->params.miimon = BOND_DEFAULT_MIIMON; - netdev_dbg(bond->dev, "Setting MII monitoring interval to %d\n", - bond->params.miimon); + if (!bond_mode_uses_arp(newval->value)) { + if (bond->params.arp_interval) { + netdev_dbg(bond->dev, "%s mode is incompatible with arp monitoring, start mii monitoring\n", + newval->string); + /* disable arp monitoring */ + bond->params.arp_interval = 0; + } + + if (!bond->params.miimon) { + /* set miimon to default value */ + bond->params.miimon = BOND_DEFAULT_MIIMON; + netdev_dbg(bond->dev, "Setting MII monitoring interval to %d\n", + bond->params.miimon); + } }
if (newval->value == BOND_MODE_ALB)