Subject: Re: [PATCH net 2/3] bonding: do failover when high prio link up

From: Saeed Mahameed <[email-masked]>
Date: Fri, 9 Dec 2022 16:03:35 -0800

On 09 Dec 18:13, Hangbin Liu wrote:
>Currently, when a high prio link enslaved, or when current link down,
>the high prio port could be selected. But when high prio link up, the
>new active slave reselection is not triggered. Fix it by checking link's
>prio when getting up.
>
>Reported-by: Liang Li <[email-masked]>
>Fixes: 0a2ff7cc8ad4 ("Bonding: add per-port priority for failover re-selection")
>Signed-off-by: Hangbin Liu <[email-masked]>
>---
> drivers/net/bonding/bond_main.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 2b6cc4dbb70e..dc6af790ff1e 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -2689,7 +2689,8 @@ static void bond_miimon_commit(struct bonding *bond)
>
> 			bond_miimon_link_change(bond, slave, BOND_LINK_UP);
>
>-			if (!rtnl_dereference(bond->curr_active_slave) || slave == primary)
>+			if (!rtnl_dereference(bond->curr_active_slave) || slave == primary ||
>+			    slave->prio > rtnl_dereference(bond->curr_active_slave)->prio)
> 				goto do_failover;

I am not really familiar with this prio logic, seems to be new. 
Anyway, what if one of the next slaves has higher prio than this slave and the
current active ? 
I see that the loop over all the slaves continues even after the failover,
but why would you do all these failovers until you settle on the highest
prio one ? 

shouldn't you do something similar to bond_choose_primary_or_current()
outside the loop, once you've updated all the slaves link states 

Please let me know if I am wandering in the wrong directions
Anyway, LGTM:

Reviewed-by: Saeed Mahameed <[email-masked]>