3.16.7-ckt3 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Nikolay Aleksandrov <[email protected]> commit b8e4500f42fe4464a33a887579147050bed8fcef upstream. Since commit 6fde8f037e60 ("bonding: fix locking in bond_loadbalance_arp_mon()") we can have a stale bond carrier state and stale curr_active_slave when using arp monitoring in loadbalance modes. The reason is that in bond_loadbalance_arp_mon() we can't have do_failover == true but slave_state_changed == false, whenever do_failover is true then slave_state_changed is also true. Then the following piece from bond_loadbalance_arp_mon(): if (slave_state_changed) { bond_slave_state_change(bond); if (BOND_MODE(bond) == BOND_MODE_XOR) bond_update_slave_arr(bond, NULL); } else if (do_failover) { block_netpoll_tx(); bond_select_active_slave(bond); unblock_netpoll_tx(); } will execute only the first branch, always and regardless of do_failover. Since these two events aren't related in such way, we need to decouple and consider them separately. For example this issue could lead to the following result: Bonding Mode: load balancing (round-robin) *MII Status: down* MII Polling Interval (ms): 0 Up Delay (ms): 0 Down Delay (ms): 0 ARP Polling Interval (ms): 100 ARP IP target/s (n.n.n.n form): 192.168.9.2 Slave Interface: ens12 *MII Status: up* Speed: 10000 Mbps Duplex: full Link Failure Count: 2 Permanent HW addr: 00:0f:53:01:42:2c Slave queue ID: 0 Slave Interface: eth1 *MII Status: up* Speed: Unknown Duplex: Unknown Link Failure Count: 70 Permanent HW addr: 52:54:00:2f:0f:8e Slave queue ID: 0 Since some interfaces are up, then the status of the bond should also be up, but it will never change unless something invokes bond_set_carrier() (i.e. enslave, bond_select_active_slave etc). Now, if I force the calling of bond_select_active_slave via for example changing primary_reselect (it can change in any mode), then the MII status goes to "up" because it calls bond_select_active_slave() which should've been done from bond_loadbalance_arp_mon() itself. CC: Veaceslav Falico <[email protected]> CC: Jay Vosburgh <[email protected]> CC: Andy Gospodarek <[email protected]> CC: Ding Tianhong <[email protected]> Fixes: 6fde8f037e60 ("bonding: fix locking in bond_loadbalance_arp_mon()") Signed-off-by: Nikolay Aleksandrov <[email protected]> Acked-by: Veaceslav Falico <[email protected]> Acked-by: Andy Gospodarek <[email protected]> Acked-by: Ding Tianhong <[email protected]> Signed-off-by: David S. Miller <[email protected]> [ luis: backported to 3.16: used davem's backport to 3.17 ] Signed-off-by: Luis Henriques <[email protected]> --- drivers/net/bonding/bond_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 5f29c9a9a316..6c795cfd6bbc 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2505,9 +2505,9 @@ static void bond_loadbalance_arp_mon(struct work_struct *work) if (!rtnl_trylock()) goto re_arm; - if (slave_state_changed) { + if (slave_state_changed) bond_slave_state_change(bond); - } else if (do_failover) { + if (do_failover) { /* the bond_select_active_slave must hold RTNL * and curr_slave_lock for write. */ -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
