Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753691Ab3GXOWq (ORCPT ); Wed, 24 Jul 2013 10:22:46 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45756 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752153Ab3GXOGn (ORCPT ); Wed, 24 Jul 2013 10:06:43 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Steffen Maier" , "James Bottomley" Date: Wed, 24 Jul 2013 15:02:45 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [05/85] [SCSI] zfcp: status read buffers on first adapter open with link down In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.101 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4929 Lines: 140 3.2.49-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Steffen Maier commit 9edf7d75ee5f21663a0183d21f702682d0ef132f upstream. Commit 64deb6efdc5504ce97b5c1c6f281fffbc150bd93 "[SCSI] zfcp: Use status_read_buf_num provided by FCP channel" started using a value returned by the channel but only evaluated the value if the fabric link is up. Commit 8d88cf3f3b9af4713642caeb221b6d6a42019001 "[SCSI] zfcp: Update status read mempool" introduced mempool resizings based on the above value. On setting an FCP device online for the very first time since boot, a new zeroed adapter object is allocated. If the link is down, the number of status read requests remains zero. Since just the config data exchange is incomplete, we proceed with adapter open recovery. However, we unconditionally call mempool_resize with adapter->stat_read_buf_num == 0 in this case. This causes a kernel message "kernel BUG at mm/mempool.c:131!" in process "zfcperp" with last function mempool_resize in Krnl PSW and zfcp_erp_thread in the Call Trace. Don't evaluate channel values which are invalid on link down. The number of status read requests is always valid, evaluated, and set to a positive minimum greater than zero. The adapter open recovery can proceed and the channel has status read buffers to inform us on a future link up event. While we are not aware of any other code path that could result in mempool resize attempts of size zero, we still also initialize the number of status read buffers to be posted to a static minimum number on adapter object allocation. Signed-off-by: Steffen Maier Signed-off-by: James Bottomley [bwh: Backported to 3.2: - Copyright notice changed slightly - Don't use zfcp_fsf_convert_portspeed()] Signed-off-by: Ben Hutchings --- drivers/s390/scsi/zfcp_aux.c | 5 ++++- drivers/s390/scsi/zfcp_fsf.c | 23 ++++++++++++++++------- 2 files changed, 20 insertions(+), 8 deletions(-) --- a/drivers/s390/scsi/zfcp_aux.c +++ b/drivers/s390/scsi/zfcp_aux.c @@ -3,7 +3,7 @@ * * Module interface and handling of zfcp data structures. * - * Copyright IBM Corporation 2002, 2010 + * Copyright IBM Corp. 2002, 2013 */ /* @@ -23,6 +23,7 @@ * Christof Schmitt * Martin Petermann * Sven Schuetz + * Steffen Maier */ #define KMSG_COMPONENT "zfcp" @@ -415,6 +416,8 @@ struct zfcp_adapter *zfcp_adapter_enqueu adapter->dma_parms.max_segment_size = ZFCP_QDIO_SBALE_LEN; adapter->ccw_device->dev.dma_parms = &adapter->dma_parms; + adapter->stat_read_buf_num = FSF_STATUS_READS_RECOM; + if (!zfcp_scsi_adapter_register(adapter)) return adapter; --- a/drivers/s390/scsi/zfcp_fsf.c +++ b/drivers/s390/scsi/zfcp_fsf.c @@ -3,7 +3,7 @@ * * Implementation of FSF commands. * - * Copyright IBM Corporation 2002, 2010 + * Copyright IBM Corp. 2002, 2013 */ #define KMSG_COMPONENT "zfcp" @@ -455,11 +455,8 @@ static int zfcp_fsf_exchange_config_eval fc_host_port_name(shost) = nsp->fl_wwpn; fc_host_node_name(shost) = nsp->fl_wwnn; - fc_host_port_id(shost) = ntoh24(bottom->s_id); - fc_host_speed(shost) = bottom->fc_link_speed; fc_host_supported_classes(shost) = FC_COS_CLASS2 | FC_COS_CLASS3; - adapter->hydra_version = bottom->adapter_type; adapter->timer_ticks = bottom->timer_interval & ZFCP_FSF_TIMER_INT_MASK; adapter->stat_read_buf_num = max(bottom->status_read_buf_num, (u16)FSF_STATUS_READS_RECOM); @@ -467,6 +464,18 @@ static int zfcp_fsf_exchange_config_eval if (fc_host_permanent_port_name(shost) == -1) fc_host_permanent_port_name(shost) = fc_host_port_name(shost); + zfcp_scsi_set_prot(adapter); + + /* no error return above here, otherwise must fix call chains */ + /* do not evaluate invalid fields */ + if (req->qtcb->header.fsf_status == FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE) + return 0; + + fc_host_port_id(shost) = ntoh24(bottom->s_id); + fc_host_speed(shost) = bottom->fc_link_speed; + + adapter->hydra_version = bottom->adapter_type; + switch (bottom->fc_topology) { case FSF_TOPO_P2P: adapter->peer_d_id = ntoh24(bottom->peer_d_id); @@ -488,8 +497,6 @@ static int zfcp_fsf_exchange_config_eval return -EIO; } - zfcp_scsi_set_prot(adapter); - return 0; } @@ -540,6 +547,8 @@ static void zfcp_fsf_exchange_config_dat &adapter->status); zfcp_fsf_link_down_info_eval(req, &qtcb->header.fsf_status_qual.link_down_info); + if (zfcp_fsf_exchange_config_evaluate(req)) + return; break; default: zfcp_erp_adapter_shutdown(adapter, 0, "fsecdh3"); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/