From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D88DC2D0BF for ; Tue, 17 Dec 2019 01:01:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFD22206D3 for ; Tue, 17 Dec 2019 01:01:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728280AbfLQBA6 (ORCPT ); Mon, 16 Dec 2019 20:00:58 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34566 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726540AbfLQAvb (ORCPT ); Mon, 16 Dec 2019 19:51:31 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ih15F-0003JP-Ul; Tue, 17 Dec 2019 00:51:30 +0000 Received: from ben by deadeye with local (Exim 4.93-RC7) (envelope-from ) id 1ih15E-0005SS-VE; Tue, 17 Dec 2019 00:51:29 +0000 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, Denis Kirjanov , "Benjamin Block" , "Martin K. Petersen" , "Jens Remus" , "Steffen Maier" Date: Tue, 17 Dec 2019 00:45:49 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 015/136] scsi: zfcp: fix reaction on bit error threshold notification In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.80-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Steffen Maier commit 2190168aaea42c31bff7b9a967e7b045f07df095 upstream. On excessive bit errors for the FCP channel ingress fibre path, the channel notifies us. Previously, we only emitted a kernel message and a trace record. Since performance can become suboptimal with I/O timeouts due to bit errors, we now stop using an FCP device by default on channel notification so multipath on top can timely failover to other paths. A new module parameter zfcp.ber_stop can be used to get zfcp old behavior. User explanation of new kernel message: * Description: * The FCP channel reported that its bit error threshold has been exceeded. * These errors might result from a problem with the physical components * of the local fibre link into the FCP channel. * The problem might be damage or malfunction of the cable or * cable connection between the FCP channel and * the adjacent fabric switch port or the point-to-point peer. * Find details about the errors in the HBA trace for the FCP device. * The zfcp device driver closed down the FCP device * to limit the performance impact from possible I/O command timeouts. * User action: * Check for problems on the local fibre link, ensure that fibre optics are * clean and functional, and all cables are properly plugged. * After the repair action, you can manually recover the FCP device by * writing "0" into its "failed" sysfs attribute. * If recovery through sysfs is not possible, set the CHPID of the device * offline and back online on the service element. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://lore.kernel.org/r/20191001104949.42810-1-maier@linux.ibm.com Reviewed-by: Jens Remus Reviewed-by: Benjamin Block Signed-off-by: Steffen Maier Signed-off-by: Martin K. Petersen [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- drivers/s390/scsi/zfcp_fsf.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) --- a/drivers/s390/scsi/zfcp_fsf.c +++ b/drivers/s390/scsi/zfcp_fsf.c @@ -20,6 +20,11 @@ struct kmem_cache *zfcp_fsf_qtcb_cache; +static bool ber_stop = true; +module_param(ber_stop, bool, 0600); +MODULE_PARM_DESC(ber_stop, + "Shuts down FCP devices for FCP channels that report a bit-error count in excess of its threshold (default on)"); + static void zfcp_fsf_request_timeout_handler(unsigned long data) { struct zfcp_adapter *adapter = (struct zfcp_adapter *) data; @@ -231,10 +236,15 @@ static void zfcp_fsf_status_read_handler case FSF_STATUS_READ_SENSE_DATA_AVAIL: break; case FSF_STATUS_READ_BIT_ERROR_THRESHOLD: - dev_warn(&adapter->ccw_device->dev, - "The error threshold for checksum statistics " - "has been exceeded\n"); zfcp_dbf_hba_bit_err("fssrh_3", req); + if (ber_stop) { + dev_warn(&adapter->ccw_device->dev, + "All paths over this FCP device are disused because of excessive bit errors\n"); + zfcp_erp_adapter_shutdown(adapter, 0, "fssrh_b"); + } else { + dev_warn(&adapter->ccw_device->dev, + "The error threshold for checksum statistics has been exceeded\n"); + } break; case FSF_STATUS_READ_LINK_DOWN: zfcp_fsf_status_read_link_down(req);