3.16.74-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Jarod Wilson <ja...@redhat.com>
commit a9b8a2b39ce65df45687cf9ef648885c2a99fe75 upstream.
There's currently a problem with toggling arp_validate on and off with an
active-backup bond. At the moment, you can start up a bond, like so:
modprobe bonding mode=1 arp_interval=100 arp_validate=0
arp_ip_targets=192.168.1.1
ip link set bond0 down
echo "ens4f0" > /sys/class/net/bond0/bonding/slaves
echo "ens4f1" > /sys/class/net/bond0/bonding/slaves
ip link set bond0 up
ip addr add 192.168.1.2/24 dev bond0
Pings to 192.168.1.1 work just fine. Now turn on arp_validate:
echo 1 > /sys/class/net/bond0/bonding/arp_validate
Pings to 192.168.1.1 continue to work just fine. Now when you go to turn
arp_validate off again, the link falls flat on it's face:
echo 0 > /sys/class/net/bond0/bonding/arp_validate
dmesg
...
[133191.911987] bond0: Setting arp_validate to none (0)
[133194.257793] bond0: bond_should_notify_peers: slave ens4f0
[133194.258031] bond0: link status definitely down for interface ens4f0,
disabling it
[133194.259000] bond0: making interface ens4f1 the new active one
[133197.330130] bond0: link status definitely down for interface ens4f1,
disabling it
[133197.331191] bond0: now running without any active interface!
The problem lies in bond_options.c, where passing in arp_validate=0
results in bond->recv_probe getting set to NULL. This flies directly in
the face of commit 3fe68df97c7f, which says we need to set recv_probe =
bond_arp_recv, even if we're not using arp_validate. Said commit fixed
this in bond_option_arp_interval_set, but missed that we can get to that
same state in bond_option_arp_validate_set as well.
One solution would be to universally set recv_probe = bond_arp_recv here
as well, but I don't think bond_option_arp_validate_set has any business
touching recv_probe at all, and that should be left to the arp_interval
code, so we can just make things much tidier here.
Fixes: 3fe68df97c7f ("bonding: always set recv_probe to bond_arp_rcv in arp
monitor")
CC: Jay Vosburgh <j.vosbu...@gmail.com>
CC: Veaceslav Falico <vfal...@gmail.com>
CC: Andy Gospodarek <a...@greyhouse.net>
CC: "David S. Miller" <da...@davemloft.net>
CC: net...@vger.kernel.org
Signed-off-by: Jarod Wilson <ja...@redhat.com>
Signed-off-by: Jay Vosburgh <jay.vosbu...@canonical.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
drivers/net/bonding/bond_options.c | 7 -------
1 file changed, 7 deletions(-)
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -1068,13 +1068,6 @@ static int bond_option_arp_validate_set(
{
pr_info("%s: Setting arp_validate to %s (%llu)\n",
bond->dev->name, newval->string, newval->value);
-
- if (bond->dev->flags & IFF_UP) {
- if (!newval->value)
- bond->recv_probe = NULL;
- else if (bond->params.arp_interval)
- bond->recv_probe = bond_arp_rcv;
- }
bond->params.arp_validate = newval->value;
return 0;
