[ofa-general] Re: [PATCH] ib cm conn sent destroy

[Steve Wise]

Pete Wyckoff wrote:
> Admittedly, I'm in this situation due to working on broken device
> code, but I think the patch below addresses a valid problem.
> Against 2.6.26-rc8.
>
> Consider a very slow link and an impatient client.  It does
> rdma_connect(), then times out at the application layer while the
> IW_CM_STATE is still CONN_SENT.  It calls rdma_reject() and finally
> rdma_destroy_id().  That leads to the BUG() in destroy_cm_id().
>
> Note the call to rdma_reject() is necessary to avoid hanging at the
> top of destroy_cm_id(), waiting for the IWCM_F_CONNECT_WAIT bit to
> be cleared.
>
>   
This isn't the intended usage model.  rdma_accept() and rdma_reject() 
are only valid on connect request cm_ids passed up in the 
CONNECT_REQUEST event on the server side...

(I'm not saying something isn't broken however :)


> 		-- Pete
>
> ----------------------------------------------------------------
>
> An application may call rdma_destroy_id() when in the CONN_SENT
> state.  This should also send a reject to the provider, just like
> for the CONN_RECV case.  It currently BUG()s without this patch.
>
> Signed-off-by: Pete Wyckoff <pw at osc.edu>
> ---
>  drivers/infiniband/core/iwcm.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c
> index 81c9195..acffdea 100644
> --- a/drivers/infiniband/core/iwcm.c
> +++ b/drivers/infiniband/core/iwcm.c
> @@ -354,6 +354,7 @@ static void destroy_cm_id(struct iw_cm_id *cm_id)
>  	case IW_CM_STATE_CLOSING:
>  		cm_id_priv->state = IW_CM_STATE_DESTROYING;
>  		break;
> +	case IW_CM_STATE_CONN_SENT:
>  	case IW_CM_STATE_CONN_RECV:
>  		/*
>  		 * App called destroy before/without calling accept after
> @@ -363,7 +364,6 @@ static void destroy_cm_id(struct iw_cm_id *cm_id)
>  		 */
>  		cm_id_priv->state = IW_CM_STATE_DESTROYING;
>  		break;
> -	case IW_CM_STATE_CONN_SENT:
>  	case IW_CM_STATE_DESTROYING:
>  	default:
>  		BUG();
>