[openib-general] [PATCH 3/4] IB CM: register and handle COMM_EST events on a QP

[Or Gerlitz]

Sean Hefty wrote:
> Register the IB CM to receive and process communication established
> events on a QP.  This requires tracking connections using local QPNs
> as part of timewait handling.
> 
> Signed-off-by: Sean Hefty <sean.hefty at intel.com>
> ---
> Index: core/cm.c
> ===================================================================
> --- core/cm.c	(revision 8629)
> +++ core/cm.c	(working copy)
> @@ -1015,20 +1089,33 @@ int ib_send_cm_req(struct ib_cm_id *cm_i
>  	cm_id_priv->local_ack_timeout =
>  				cm_req_get_primary_local_ack_timeout(req_msg);
>  
> +	cm_id_priv->timewait_info->local_ca_guid = req_msg->local_ca_guid;
> +	cm_id_priv->timewait_info->local_qpn = cm_id_priv->local_qpn;
> +	spin_lock_irqsave(&cm.lock, flags);
> +	if (cm_insert_local_qpn(cm_id_priv->timewait_info))
> +		ret = -EADDRINUSE;
> +	spin_unlock_irqrestore(&cm.lock, flags);

why bother doing it here? can't the race happen only on the passive side 
of the connection?

Just to make sure, following reading the code/patch i understand the 
case where the RTU does appear following the event is handled, what 
would happen in this case is that an EINVAL status would be returned by 
cm_rtu_handler to cm_work_handler and that's all.

Or.