From patchwork Wed May 10 19:35:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Bryant G. Ly" X-Patchwork-Id: 9720607 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CE84C60236 for ; Wed, 10 May 2017 19:35:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E16C328639 for ; Wed, 10 May 2017 19:35:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D61862863C; Wed, 10 May 2017 19:35:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8BE2F28639 for ; Wed, 10 May 2017 19:35:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754350AbdEJTfz (ORCPT ); Wed, 10 May 2017 15:35:55 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:33335 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753583AbdEJTfy (ORCPT ); Wed, 10 May 2017 15:35:54 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v4AJTFaV067808 for ; Wed, 10 May 2017 15:35:53 -0400 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ac5r71v01-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 10 May 2017 15:35:53 -0400 Received: from localhost by e11.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 10 May 2017 15:35:52 -0400 Received: from b01cxnp23032.gho.pok.ibm.com (9.57.198.27) by e11.ny.us.ibm.com (146.89.104.198) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 10 May 2017 15:35:50 -0400 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v4AJZoPs43384910; Wed, 10 May 2017 19:35:50 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 788B0AC041; Wed, 10 May 2017 15:35:39 -0400 (EDT) Received: from bryants-mbp-3.rchland.ibm.com (unknown [9.10.80.59]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP id 01E3BAC03A; Wed, 10 May 2017 15:35:38 -0400 (EDT) From: "Bryant G. Ly" To: nab@linux-iscsi.org Cc: mikecyr@linux.vnet.ibm.com, mikecyr@us.ibm.com, seroyer@linux.vnet.ibm.com, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, "Bryant G. Ly" , Subject: [PATCH v2] ibmvscsis: Fix the incorrect req_lim_delta Date: Wed, 10 May 2017 14:35:47 -0500 X-Mailer: git-send-email 2.5.4 (Apple Git-61) X-TM-AS-GCONF: 00 x-cbid: 17051019-2213-0000-0000-000001B402FA X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007044; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000210; SDB=6.00858795; UDB=6.00425564; IPR=6.00638269; BA=6.00005342; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015400; XFM=3.00000015; UTC=2017-05-10 19:35:51 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17051019-2214-0000-0000-00005610CA71 Message-Id: <1494444947-77322-1-git-send-email-bryantly@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-05-10_15:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=3 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1705100133 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The current code is not correctly calculating the req_lim_delta. We want to make sure vscsi->credit is always incremented when we do not send a response for the scsi op. Thus for the case where there is a successfully aborted task we need to make sure the vscsi->credit is incremented. v2 - Moves the original location of the vscsi->credit increment to a better spot. Since if we increment credit, the next command we send back will have increased req_lim_delta. But we probably shouldn't be doing that until the aborted cmd is actually released. Otherwise the client will think that it can send a new command, and we could find ourselves short of command elements. Not likely, but could happen. This patch depends on both: commit 25e78531268e ("ibmvscsis: Do not send aborted task response") commit 38b2788edbd6 ("ibmvscsis: Clear left-over abort_cmd pointers") Signed-off-by: Bryant G. Ly Reviewed-by: Michael Cyr Cc: # v4.8+ --- drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c index ee64241..abf6026 100644 --- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c +++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c @@ -1791,6 +1791,25 @@ static void ibmvscsis_send_messages(struct scsi_info *vscsi) list_del(&cmd->list); ibmvscsis_free_cmd_resources(vscsi, cmd); + /* + * With a successfully aborted op + * through LIO we want to increment the + * the vscsi credit so that when we dont + * send a rsp to the original scsi abort + * op (h_send_crq), but the tm rsp to + * the abort is sent, the credit is + * correctly sent with the abort tm rsp. + * We would need 1 for the abort tm rsp + * and 1 credit for the aborted scsi op. + * Thus we need to increment here. + * Also we want to increment the credit + * here because we want to make sure + * cmd is actually released first + * otherwise the client will think it + * it can send a new cmd, and we could + * find ourselves short of cmd elements. + */ + vscsi->credit += 1; } else { iue = cmd->iue; @@ -2965,10 +2984,7 @@ static long srp_build_response(struct scsi_info *vscsi, rsp->opcode = SRP_RSP; - if (vscsi->credit > 0 && vscsi->state == SRP_PROCESSING) - rsp->req_lim_delta = cpu_to_be32(vscsi->credit); - else - rsp->req_lim_delta = cpu_to_be32(1 + vscsi->credit); + rsp->req_lim_delta = cpu_to_be32(1 + vscsi->credit); rsp->tag = cmd->rsp.tag; rsp->flags = 0;