[ofw] [PATCH] SRP dreq deadlock

[Gilad Shainer]

Usha,

Can you or Alex send what issues Alex has patches for? It could be that
others are facing the same issues and trying to solve the same problems.

Thanks,
Gilad.


> -----Original Message-----
> From: Usha Srinivasan [mailto:usha.srinivasan at qlogic.com]
> Sent: Thursday, February 14, 2008 5:07 PM
> To: Yossi Leybovich; Leonid Keller; ofw at lists.openfabrics.org
> Subject: RE: [ofw] [PATCH] SRP dreq deadlock
> 
> Hi Yossi,
> Alex Estrin here at QLogic KOP has a couple of SRP patches pending to 
> be merged into Win OF. One patch addresses this deadlock bug along 
> with QP err handling and session recovery. A second patch will add a 
> bit for flow control handling in order to withstand heavy load.
> 
> Alex will be preparing his patch and will submit them to the community

> for review hopefully next week.
> 
> Usha
> 
> -----Original Message-----
> From: ofw-bounces at lists.openfabrics.org 
> [mailto:ofw-bounces at lists.openfabrics.org] On Behalf Of Yossi 
> Leybovich
> Sent: Thursday, February 14, 2008 5:58 AM
> To: Leonid Keller; ofw at lists.openfabrics.org
> Subject: [ofw] [PATCH] SRP dreq deadlock
> 
> Leonid
> 
> While working Windows SRP with Linux SRPT (OFED) I discover that after

> removing the SRPT the windows side stop receiving MADs.
> The problem is that the SRP while handling the dreq callback of the 
> target try to reconnect and wait (in the context of the callback
> thread) to the connect operation to end.
> This is deadlock as the operation will not finish till SRP release the

> callback thread.
> 
> This patch remove the reconnect code from the dreq callback.
> 
> Thanks
> Yossi
> Index: srp_connection.c
> ===================================================================
> --- srp_connection.c	(revision 2166)
> +++ srp_connection.c	(working copy)
> @@ -285,8 +285,8 @@
>  	ib_cm_drep_t    cm_drep;
>  	ib_api_status_t status;
>  	int             i;
> -	int             retry_count = 0;
> 
> +
>  	SRP_ENTER( SRP_DBG_PNP );
> 
>  	SRP_PRINT( TRACE_LEVEL_INFORMATION, SRP_DBG_DEBUG, @@ -334,75
> +334,9 @@
>  	SRP_PRINT( TRACE_LEVEL_VERBOSE, SRP_DBG_DEBUG,
>  		("Session Object ref_cnt = %d\n",
> p_srp_session->obj.ref_cnt) );
>  	cl_obj_destroy( &p_srp_session->obj );
> -
> -	do
> -	{
> -		retry_count++;
> -
> -		SRP_PRINT( TRACE_LEVEL_INFORMATION, SRP_DBG_DEBUG,
> -			("Attempting to reconnect %s. Connection Attempt
> Count = %d.\n",
> -			 p_hba->ioc_info.profile.id_string,
> -			 retry_count) );
> -
> -		SRP_PRINT( TRACE_LEVEL_VERBOSE, SRP_DBG_DEBUG,
> -			("Creating New Session For Service Entry Index
> %d.\n",
> -			p_hba->ioc_info.profile.num_svc_entries));
> -		p_srp_session = srp_new_session(
> -			p_hba, &p_hba->p_svc_entries[i], &status );
> -		if ( p_srp_session == NULL )
> -		{
> -			status = IB_INSUFFICIENT_MEMORY;
> -			break;
> -		}
> -
> -		SRP_PRINT( TRACE_LEVEL_VERBOSE, SRP_DBG_DEBUG,
> -			("New Session For Service Entry Index %d
> Created.\n",
> -			p_hba->ioc_info.profile.num_svc_entries));
> -		SRP_PRINT( TRACE_LEVEL_VERBOSE, SRP_DBG_DEBUG,
> -			("Logging Into Session.\n"));
> -		status = srp_session_login( p_srp_session );
> -		if ( status == IB_SUCCESS )
> -		{
> -			if ( p_hba->max_sg >
> p_srp_session->connection.max_scatter_gather_entries )
> -			{
> -				p_hba->max_sg =
> p_srp_session->connection.max_scatter_gather_entries;
> -			}
> -
> -			if ( p_hba->max_srb_ext_sz >
> p_srp_session->connection.init_to_targ_iu_sz )
> -			{
> -				p_hba->max_srb_ext_sz =
> -					sizeof( srp_send_descriptor_t )
> -
> -					SRP_MAX_IU_SIZE +
> -
> p_srp_session->connection.init_to_targ_iu_sz;
> -			}
> -
> -			cl_obj_lock( &p_hba->obj );
> -			p_hba->session_list[i] = p_srp_session;
> -			cl_obj_unlock( &p_hba->obj );
> -
> -			SRP_PRINT( TRACE_LEVEL_VERBOSE, SRP_DBG_DEBUG,
> -				("Session Login Issued
> Successfully.\n"));
> -		}
> -		else
> -		{
> -			SRP_PRINT( TRACE_LEVEL_ERROR, SRP_DBG_ERROR,
> -				("Session Login Failure Status = %d.\n",
> status));
> -			SRP_PRINT( TRACE_LEVEL_VERBOSE, SRP_DBG_DEBUG,
> -				 ("Session Object ref_cnt = %d\n",
> p_srp_session->obj.ref_cnt) );
> -			cl_obj_destroy( &p_srp_session->obj );
> -		}
> -	} while ( (status != IB_SUCCESS) && (retry_count < 3) );
> -
> -	if ( status == IB_SUCCESS )
> -	{
> -		SRP_PRINT( TRACE_LEVEL_INFORMATION, SRP_DBG_DEBUG,
> -			 ("Resuming Adapter for %s.\n",
> p_hba->ioc_info.profile.id_string) );
> -		p_hba->adapter_paused = FALSE;
> -		StorPortReady( p_hba->p_ext );
> -//		StorPortNotification( BusChangeDetected, p_hba->p_ext, 0
> );
> -	}
> -
> +
>  	SRP_EXIT( SRP_DBG_PNP );
> +	return ;
>  }
> 
>  /* __srp_cm_reply_cb */
> 
>