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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham 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 C2BFDC71155 for ; Tue, 1 Dec 2020 21:31:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62B172086A for ; Tue, 1 Dec 2020 21:31:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="pOZbGUaJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388128AbgLAVbD (ORCPT ); Tue, 1 Dec 2020 16:31:03 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:57246 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729335AbgLAVbC (ORCPT ); Tue, 1 Dec 2020 16:31:02 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0B1LSuTP081049; Tue, 1 Dec 2020 21:30:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : in-reply-to : references; s=corp-2020-01-29; bh=fkRovDNiYxLoydWfMZ9RPNbtQ5bCCtqKzQ4tk6IreQM=; b=pOZbGUaJVzWYWZk7mE2nbk4UyJzSJ5HDRpr6mH74dGG0Y6LDwXOGrUwoS4XVJAC3Dxcm JTFFgYbihJSJrgvPfNvvMixTCnlIThu1lYZgEZA+w+D63ku2+v5ayVJR9wGhdbmutBXT Yon4zhx9Vi+0stCGzhZrVoF9sDRUXLrgjOvVbj/lLgzJ5AlPY5x73TD7kafXTyTlqVEO dX9Z4LFA8WeB9b+LU5OXGnou8vwp62rZkzPQ1H48CEHuAqP2p1nkpRPOUVR8rhEL8emy Lcmcu+p567jthBWQEJ+cgUtNYLl/FK1jN7UsyZ2d8zgMmg1RY4dIyZSAA1CtmWFtph4Q iQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 353egkmw5d-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 01 Dec 2020 21:30:13 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0B1LBL7C164011; Tue, 1 Dec 2020 21:30:12 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 3540fxkwpr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 01 Dec 2020 21:30:12 +0000 Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 0B1LU9qU021009; Tue, 1 Dec 2020 21:30:11 GMT Received: from ol2.localdomain (/73.88.28.6) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 01 Dec 2020 13:30:08 -0800 From: Mike Christie To: subbu.seetharaman@broadcom.com, ketan.mukadam@broadcom.com, jitendra.bhivare@broadcom.com, lduncan@suse.com, cleech@redhat.com, njavali@marvell.com, mrangankar@marvell.com, GR-QLogic-Storage-Upstream@marvell.com, varun@chelsio.com, martin.petersen@oracle.com, linux-scsi@vger.kernel.org, james.bottomley@hansenpartnership.com Subject: [PATCH 06/15] libiscsi: drop frwd lock for session state Date: Tue, 1 Dec 2020 15:29:47 -0600 Message-Id: <1606858196-5421-7-git-send-email-michael.christie@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1606858196-5421-1-git-send-email-michael.christie@oracle.com> References: <1606858196-5421-1-git-send-email-michael.christie@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9822 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 suspectscore=0 phishscore=0 mlxlogscore=999 adultscore=0 mlxscore=0 bulkscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012010129 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9822 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 bulkscore=0 suspectscore=0 phishscore=0 mlxlogscore=999 lowpriorityscore=0 malwarescore=0 priorityscore=1501 spamscore=0 impostorscore=0 clxscore=1015 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012010130 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org This drops the frwd lock for the session state checks in queuecommand. Like with the transport class case, we only need it as a hint since when the session is cleaned up we will block the session which flushes the queues, and then we clean up all running IO. So the locking just prevents cleaning up extra cmds. It is still needed: 1. when accessing suspend_tx in queuecomand because drivers that implement ep_disconnect will set that bit from disconnect (called before stop) and expect that no new commands will be queued to it. Note that the comment for this was wrong and that is fixed in this patch. 2. the list addition for the drivers that use the iscsi xmit wq. Signed-off-by: Mike Christie --- drivers/scsi/libiscsi.c | 10 +++++++--- include/scsi/libiscsi.h | 5 +++-- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 1296a10..12bfb5a 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -1704,7 +1704,6 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc) cls_session = starget_to_session(scsi_target(sc->device)); session = cls_session->dd_data; - spin_lock_bh(&session->frwd_lock); reason = iscsi_session_chkready(cls_session); if (reason) { @@ -1761,7 +1760,9 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc) goto fault; } + spin_lock_bh(&session->frwd_lock); if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) { + spin_unlock_bh(&session->frwd_lock); reason = FAILURE_SESSION_IN_RECOVERY; sc->result = DID_REQUEUE << 16; goto fault; @@ -1769,6 +1770,7 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc) task = iscsi_alloc_task(conn, sc); if (!task) { + spin_unlock_bh(&session->frwd_lock); reason = FAILURE_OOM; goto reject; } @@ -1803,21 +1805,23 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc) return 0; prepd_reject: + spin_unlock_bh(&session->frwd_lock); + spin_lock_bh(&session->back_lock); iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ); spin_unlock_bh(&session->back_lock); reject: - spin_unlock_bh(&session->frwd_lock); ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason); return SCSI_MLQUEUE_TARGET_BUSY; prepd_fault: + spin_unlock_bh(&session->frwd_lock); + spin_lock_bh(&session->back_lock); iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ); spin_unlock_bh(&session->back_lock); fault: - spin_unlock_bh(&session->frwd_lock); ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason); scsi_set_resid(sc, scsi_bufflen(sc)); diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h index b649ec5..25dbc5d 100644 --- a/include/scsi/libiscsi.h +++ b/include/scsi/libiscsi.h @@ -326,8 +326,9 @@ struct iscsi_session { * can enclose the mutual exclusion zone protected by the backward lock * but not vice versa. */ - spinlock_t frwd_lock; /* protects session state, * - * cmdsn and session * + spinlock_t frwd_lock; /* protects session state * + * in the eh paths, cmdsn * + * suspend bit and session * * resources: * * - cmdpool kfifo_out , * * - mgmtpool, queues */ -- 1.8.3.1