Subject: Re: [PATCH next] bonding: pair enable_port with slave_arr_updates

From: Jay Vosburgh <[email-masked]>
Date: Thu, 27 Jan 2022 15:54:29 -0800

Mahesh Bandewar <[email-masked]> wrote:

>When 803.2ad mode enables a participating port, it should update
>the slave-array. I have observed that the member links are participating
>and are part of the active aggregator while the traffic is egressing via
>only one member link (in a case where two links are participating). Via
>krpobes I discovered that that slave-arr has only one link added while
>the other participating link wasn't part of the slave-arr.
>
>I couldn't see what caused that situation but the simple code-walk
>through provided me hints that the enable_port wasn't always associated
>with the slave-array update.
>
>Signed-off-by: Mahesh Bandewar <[email-masked]>
>---
> drivers/net/bonding/bond_3ad.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
>diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
>index 6006c2e8fa2b..f20bbc18a03f 100644
>--- a/drivers/net/bonding/bond_3ad.c
>+++ b/drivers/net/bonding/bond_3ad.c
>@@ -1024,6 +1024,8 @@ static void ad_mux_machine(struct port *port, bool *update_slave_arr)
> 
> 					__enable_port(port);
> 				}
>+				/* Slave array needs update */
>+				*update_slave_arr = true;
> 			}

	Shouldn't this be in the same block as the __enable_port() call?
If I'm reading the code correctly, as written this will trigger an
update of the array on every pass of the state machine (every 100ms) if
any port is in COLLECTING_DISTRIBUTING state, which is the usual case.

> 			break;
> 		default:
>@@ -1779,6 +1781,8 @@ static void ad_agg_selection_logic(struct aggregator *agg,
> 			     port = port->next_port_in_aggregator) {
> 				__enable_port(port);
> 			}
>+			/* Slave array needs update. */
>+			*update_slave_arr = true;
> 		}

	I suspect this change would only affect your issue if the port
in question was failing to partner (i.e., the peer wasn't running LACP
or there was some failure in the LACP negotiation).  If the ports in
your test were in the same aggregator, that shouldn't be the case, as I
believe unpartnered ports are always individual (not in an aggregator).

	Do you have a test?

	-J

> 	}
> 
>-- 
>2.35.0.rc0.227.g00780c9af4-goog
>

---
	-Jay Vosburgh, [email-masked]