Re: [PATCH] bonding: force enable lacp port after link state recovery for 802.3ad

From: Jay Vosburgh
Date: Tue Aug 20 2019 - 19:14:44 EST


<zhangsha.zhang@xxxxxxxxxx> wrote:

>From: Sha Zhang <zhangsha.zhang@xxxxxxxxxx>
>
>After the commit 334031219a84 ("bonding/802.3ad: fix slave link
>initialization transition states") merged,
>the slave's link status will be changed to BOND_LINK_FAIL
>from BOND_LINK_DOWN in the following scenario:
>- Driver reports loss of carrier and
> bonding driver receives NETDEV_CHANGE notifier
>- slave's duplex and speed is zerod and
> its port->is_enabled is cleard to 'false';
>- Driver reports link recovery and
> bonding driver receives NETDEV_UP notifier;
>- If speed/duplex getting failed here, the link status
> will be changed to BOND_LINK_FAIL;
>- The MII monotor later recover the slave's speed/duplex
> and set link status to BOND_LINK_UP, but remains
> the 'port->is_enabled' to 'false'.
>
>In this scenario, the lacp port will not be enabled even its speed
>and duplex are valid. The bond will not send LACPDU's, and its
>state is 'AD_STATE_DEFAULTED' forever. The simplest fix I think
>is to force enable lacp after port slave speed check in
>bond_miimon_commit. As enabled, the lacp port can run its state machine
>normally after link recovery.
>
>Signed-off-by: Sha Zhang <zhangsha.zhang@xxxxxxxxxx>
>---
> drivers/net/bonding/bond_main.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 931d9d9..379253a 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -2194,6 +2194,7 @@ static void bond_miimon_commit(struct bonding *bond)
> {
> struct list_head *iter;
> struct slave *slave, *primary;
>+ struct port *port;
>
> bond_for_each_slave(bond, slave, iter) {
> switch (slave->new_link) {
>@@ -2205,8 +2206,13 @@ static void bond_miimon_commit(struct bonding *bond)
> * link status
> */
> if (BOND_MODE(bond) == BOND_MODE_8023AD &&
>- slave->link == BOND_LINK_UP)
>+ slave->link == BOND_LINK_UP) {
> bond_3ad_adapter_speed_duplex_changed(slave);
>+ if (slave->duplex == DUPLEX_FULL) {
>+ port = &(SLAVE_AD_INFO(slave)->port);
>+ port->is_enabled = true;
>+ }
>+ }

I don't believe that testing duplex here is correct; is_enabled
is not controlled by duplex, but by carrier state. Duplex does affect
whether or not a port is permitted to aggregate, but that's entirely
separate logic (the AD_PORT_LACP_ENABLED flag).

Would it be better to call bond_3ad_handle_link_change() here,
instead of manually testing duplex and setting is_enabled?

-J

> continue;
>
> case BOND_LINK_UP:
>--
>1.8.3.1
>

---
-Jay Vosburgh, jay.vosburgh@xxxxxxxxxxxxx