Subject: Re: [PATCH net-next v2 2/2] bonding: fix link recovery in mode 2 when updelay is nonzero

From: Jay Vosburgh <[email-masked]>
Date: Tue, 22 Nov 2022 22:25:20 -0800

Jonathan Toppins <[email-masked]> wrote:

>Before this change when a bond in mode 2 lost link, all of its slaves
>lost link, the bonding device would never recover even after the
>expiration of updelay. This change removes the updelay when the bond
>currently has no usable links. Conforming to bonding.txt section 13.1
>paragraph 4.
>
>Fixes: 41f891004063 ("bonding: ignore updelay param when there is no active slave")
>Signed-off-by: Jonathan Toppins <[email-masked]>

	This looks correct, although I suspect it would affect more than
just balance-xor ("mode 2"); if memory serves, balance-rr mode operates
similarly.

Acked-by: Jay Vosburgh <[email-masked]>

	-J

>---
>
>Notes:
>    v2:
>     * added fixes tag and reposted to net tree
>
> drivers/net/bonding/bond_main.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index f298b9b3eb77..f747bd60d399 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -2536,7 +2536,16 @@ static int bond_miimon_inspect(struct bonding *bond)
> 	struct slave *slave;
> 	bool ignore_updelay;
> 
>-	ignore_updelay = !rcu_dereference(bond->curr_active_slave);
>+	if (BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP) {
>+		ignore_updelay = !rcu_dereference(bond->curr_active_slave);
>+	} else {
>+		struct bond_up_slave *usable_slaves;
>+
>+		usable_slaves = rcu_dereference(bond->usable_slaves);
>+
>+		if (usable_slaves && usable_slaves->count == 0)
>+			ignore_updelay = true;
>+	}
> 
> 	bond_for_each_slave_rcu(bond, slave, iter) {
> 		bond_propose_link_state(slave, BOND_LINK_NOCHANGE);
>-- 
>2.31.1
>