RE: [PATCH v2 05/13] IB/cm: Share listening CM IDs

Hefty, Sean
2015-07-27T19:04:30Z

> +/**
> + * Create a new listening ib_cm_id and listen on the given service ID.
> + *
> + * If there's an existing ID listening on that same device and service
> ID,
> + * return it.
> + *
> + * @device: Device associated with the cm_id. All related communication
> will
> + * be associated with the specified device.
> + * @cm_handler: Callback invoked to notify the user of CM events.
> + * @service_id: Service identifier matched against incoming connection
> + * and service ID resolution requests. The service ID should be
> specified
> + * network-byte order. If set to IB_CM_ASSIGN_SERVICE_ID, the CM will
> + * assign a service ID to the caller.
> + * @service_mask: Mask applied to service ID used to listen across a
> + * range of service IDs. If set to 0, the service ID is matched
> + * exactly. This parameter is ignored if %service_id is set to
> + * IB_CM_ASSIGN_SERVICE_ID.
> + *
> + * Callers should call ib_destroy_cm_id when done with the listener ID.
> + */
> +struct ib_cm_id *ib_cm_insert_listen(struct ib_device *device,
> + ib_cm_handler cm_handler,
> + __be64 service_id, __be64 service_mask)
> +{
> + struct cm_id_private *cm_id_priv;
> + struct ib_cm_id *cm_id;
> + unsigned long flags;
> + int err = 0;
> +
> + /* Create an ID in advance, since the creation may sleep */
> + cm_id = ib_create_cm_id(device, cm_handler, NULL);
> + if (IS_ERR(cm_id))
> + return cm_id;
> +
> + spin_lock_irqsave(&cm.lock, flags);
> +
> + if (service_id == IB_CM_ASSIGN_SERVICE_ID)
> + goto new_id;
> +
> + /* Find an existing ID */
> + cm_id_priv = cm_find_listen(device, service_id, NULL);
> + if (cm_id_priv) {

The service_mask is being ignored through this code path.

> + if (cm_id->cm_handler != cm_handler || cm_id->context) {
> + /* Sharing an ib_cm_id with different handlers is not
> + * supported */
> + spin_unlock_irqrestore(&cm.lock, flags);
> + return ERR_PTR(-EINVAL);
> + }
> + atomic_inc(&cm_id_priv->refcount);
> + ++cm_id_priv->listen_sharecount;
> + spin_unlock_irqrestore(&cm.lock, flags);
> +
> + ib_destroy_cm_id(cm_id);
> + cm_id = &cm_id_priv->id;
> + return cm_id;
> + }
> +
> +new_id:
> + /* Use newly created ID */
> + err = __ib_cm_listen(cm_id, service_id, service_mask, NULL, false);
> +
> + spin_unlock_irqrestore(&cm.lock, flags);
> +
> + if (err) {
> + ib_destroy_cm_id(cm_id);
> + return ERR_PTR(err);
> + }
> + return cm_id;
> +}
> +EXPORT_SYMBOL(ib_cm_insert_listen);
> +
> static __be64 cm_form_tid(struct cm_id_private *cm_id_priv,
> enum cm_msg_sequence msg_seq)
> {