From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752717AbdKVCqf (ORCPT ); Tue, 21 Nov 2017 21:46:35 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:57462 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752538AbdKVCkv (ORCPT ); Tue, 21 Nov 2017 21:40:51 -0500 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, "Martin K. Petersen" , "Steffen Maier" , "Benjamin Block" Date: Wed, 22 Nov 2017 01:58:12 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 023/133] scsi: zfcp: fix queuecommand for scsi_eh commands when DIX enabled In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 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 3.16.51-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Steffen Maier commit 71b8e45da51a7b64a23378221c0a5868bd79da4f upstream. Since commit db007fc5e20c ("[SCSI] Command protection operation"), scsi_eh_prep_cmnd() saves scmd->prot_op and temporarily resets it to SCSI_PROT_NORMAL. Other FCP LLDDs such as qla2xxx and lpfc shield their queuecommand() to only access any of scsi_prot_sg...() if (scsi_get_prot_op(cmd) != SCSI_PROT_NORMAL). Do the same thing for zfcp, which introduced DIX support with commit ef3eb71d8ba4 ("[SCSI] zfcp: Introduce experimental support for DIF/DIX"). Otherwise, TUR SCSI commands as part of scsi_eh likely fail in zfcp, because the regular SCSI command with DIX protection data, that scsi_eh re-uses in scsi_send_eh_cmnd(), of course still has (scsi_prot_sg_count() != 0) and so zfcp sends down bogus requests to the FCP channel hardware. This causes scsi_eh_test_devices() to have (finish_cmds == 0) [not SCSI device is online or not scsi_eh_tur() failed] so regular SCSI commands, that caused / were affected by scsi_eh, are moved to work_q and scsi_eh_test_devices() itself returns false. In turn, it unnecessarily escalates in our case in scsi_eh_ready_devs() beyond host reset to finally scsi_eh_offline_sdevs() which sets affected SCSI devices offline with the following kernel message: "kernel: sd H:0:T:L: Device offlined - not ready after error recovery" Signed-off-by: Steffen Maier Fixes: ef3eb71d8ba4 ("[SCSI] zfcp: Introduce experimental support for DIF/DIX") Reviewed-by: Benjamin Block Signed-off-by: Benjamin Block Signed-off-by: Martin K. Petersen Signed-off-by: Ben Hutchings --- drivers/s390/scsi/zfcp_fsf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/s390/scsi/zfcp_fsf.c +++ b/drivers/s390/scsi/zfcp_fsf.c @@ -2259,7 +2259,8 @@ int zfcp_fsf_fcp_cmnd(struct scsi_cmnd * fcp_cmnd = (struct fcp_cmnd *) &req->qtcb->bottom.io.fcp_cmnd; zfcp_fc_scsi_to_fcp(fcp_cmnd, scsi_cmnd, 0); - if (scsi_prot_sg_count(scsi_cmnd)) { + if ((scsi_get_prot_op(scsi_cmnd) != SCSI_PROT_NORMAL) && + scsi_prot_sg_count(scsi_cmnd)) { zfcp_qdio_set_data_div(qdio, &req->qdio_req, scsi_prot_sg_count(scsi_cmnd)); retval = zfcp_qdio_sbals_from_sg(qdio, &req->qdio_req,