3.16.74-rc1 review patch. If anyone has any objections, please let me know.
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From: Jarod Wilson jarod@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.vosburgh@gmail.com CC: Veaceslav Falico vfalico@gmail.com CC: Andy Gospodarek andy@greyhouse.net CC: "David S. Miller" davem@davemloft.net CC: netdev@vger.kernel.org Signed-off-by: Jarod Wilson jarod@redhat.com Signed-off-by: Jay Vosburgh jay.vosburgh@canonical.com Signed-off-by: David S. Miller davem@davemloft.net [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@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;