[rds-devel] [net-next, v1, 7/7] net/rds: Trigger rds_send_ping() more than once

[Simon Horman]

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net/rds: Trigger rds_send_ping() more than once

This commit ensures that rds_send_ping() is triggered after reconnect
to properly communicate path capabilities, especially after an RDS
module reload. It also validates source port modulo during fan-out.

> diff --git a/net/rds/send.c b/net/rds/send.c
> index ea3b57e9191b..8e7ece085ff1 100644
> --- a/net/rds/send.c
> +++ b/net/rds/send.c
> @@ -1328,6 +1328,23 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
>  		cpath = &conn->c_path[0];
>  	}
>
> +	/* c_npaths == 0 if we have not talked to this peer
> +	 * before.  Initiate a connection request to the
> +	 * peer right away.
> +	 */
> +	if (conn->c_trans->t_mp_capable &&
> +	    !rds_conn_path_up(&conn->c_path[0])) {

This isn't a bug, but the comment says "c_npaths == 0" while the code
checks "!rds_conn_path_up()". These conditions are different:
c_npaths == 0 means no paths negotiated yet, while !rds_conn_path_up()
is true for any state other than RDS_CONN_UP (DOWN, CONNECTING,
DISCONNECTING, ERROR, RESETTING).

The commit message mentions "after a re-connect to any peer" which
aligns with the code, but the comment specifically mentions c_npaths
which isn't checked. Should the comment be updated to reflect the
actual logic?

> +		/* Ensures that only one request is queued.  And
> +		 * rds_send_ping() ensures that only one ping is
> +		 * outstanding.
> +		 */

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