From: Mahesh Bandewar <mahe...@google.com>
The primary issue is that mii-inspect phase updates link-state and
expects changes to be committed during the mii-commit phase. After
the inspect phase if it fails to acquire rtnl-mutex, the commit
phase (bond_mii_commit) doesn't get to run. This partially updated
state stays and makes the internal-state inconsistent.
e.g. setup bond0 => slaves: eth1, eth2
eth1 goes DOWN -> UP
mii_monitor()
mii-inspect()
bond_set_slave_link_state(eth1, UP, DontNotify)
rtnl_trylock() <- fails!
Next mii-monitor round
eth1: No change
mii_monitor()
mii-inspect()
eth1->link == current-status (ethtool_ops->get_link)
no-change-detected
End result:
eth1:
Link = BOND_LINK_UP
Speed = 0xfffff [SpeedUnknown]
Duplex = 0xff [DuplexUnknown]
This doesn't always happen but for some unlucky machines in a large set
of machines it creates problems.
The fix for this is to avoid making changes during inspect phase and
postpone them until acquiring the rtnl-mutex / invoking commit phase.
Signed-off-by: Mahesh Bandewar <mahe...@google.com>
---
drivers/net/bonding/bond_main.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index ba934020dfaa..85999e479916 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2033,8 +2033,7 @@ static int bond_miimon_inspect(struct bonding *bond)
if (link_state)
continue;
- bond_set_slave_link_state(slave, BOND_LINK_FAIL,
- BOND_SLAVE_NOTIFY_LATER);
+ bond_propose_link_state(slave, BOND_LINK_FAIL);
slave->delay = bond->params.downdelay;
if (slave->delay) {
netdev_info(bond->dev, "link status down for
%sinterface %s, disabling it in %d ms\n",
@@ -2049,8 +2048,7 @@ static int bond_miimon_inspect(struct bonding *bond)
case BOND_LINK_FAIL:
if (link_state) {
/* recovered before downdelay expired */
- bond_set_slave_link_state(slave, BOND_LINK_UP,
-
BOND_SLAVE_NOTIFY_LATER);
+ bond_propose_link_state(slave, BOND_LINK_UP);
slave->last_link_up = jiffies;
netdev_info(bond->dev, "link status up again
after %d ms for interface %s\n",
(bond->params.downdelay -
slave->delay) *
@@ -2072,8 +2070,7 @@ static int bond_miimon_inspect(struct bonding *bond)
if (!link_state)
continue;
- bond_set_slave_link_state(slave, BOND_LINK_BACK,
- BOND_SLAVE_NOTIFY_LATER);
+ bond_propose_link_state(slave, BOND_LINK_BACK);
slave->delay = bond->params.updelay;
if (slave->delay) {
@@ -2086,9 +2083,7 @@ static int bond_miimon_inspect(struct bonding *bond)
/*FALLTHRU*/
case BOND_LINK_BACK:
if (!link_state) {
- bond_set_slave_link_state(slave,
- BOND_LINK_DOWN,
-
BOND_SLAVE_NOTIFY_LATER);
+ bond_propose_link_state(slave, BOND_LINK_DOWN);
netdev_info(bond->dev, "link status down again
after %d ms for interface %s\n",
(bond->params.updelay -
slave->delay) *
bond->params.miimon,
@@ -2225,6 +2220,8 @@ static void bond_mii_monitor(struct work_struct *work)
mii_work.work);
bool should_notify_peers = false;
unsigned long delay;
+ struct slave *slave;
+ struct list_head *iter;
delay = msecs_to_jiffies(bond->params.miimon);
@@ -2245,6 +2242,9 @@ static void bond_mii_monitor(struct work_struct *work)
goto re_arm;
}
+ bond_for_each_slave(bond, slave, iter) {
+ bond_commit_link_state(slave, BOND_SLAVE_NOTIFY_LATER);
+ }
bond_miimon_commit(bond);
rtnl_unlock(); /* might sleep, hold no other locks */
--
2.12.1.578.ge9c3154ca4-goog
