From patchwork Thu Aug 17 18:21:46 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Karan Tilak Kumar (kartilak)" X-Patchwork-Id: 13356872 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB676C2FC0F for ; Thu, 17 Aug 2023 18:24:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354342AbjHQSYI (ORCPT ); Thu, 17 Aug 2023 14:24:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354480AbjHQSX6 (ORCPT ); Thu, 17 Aug 2023 14:23:58 -0400 Received: from rcdn-iport-4.cisco.com (rcdn-iport-4.cisco.com [173.37.86.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3DA23C06; Thu, 17 Aug 2023 11:23:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=3332; q=dns/txt; s=iport; t=1692296613; x=1693506213; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=EAFmCMjCURKVOVoD03Cmoz021Qx7FN68afEqBii0SgA=; b=Jc7fp++knzYmrMr7VNa+2ZT3tCvzh0QK14up38tkmI0RdSrgUkomDsy3 Q9OW4GJ2jCtkI1eKC/oMzZj1+WILZR2qDJZOzcbR+rnfdKNp+dhQv2Xwa 5bt/GYE+NgyDt5Ah8siC/l09+M1JGprNgqpQAGlRuBD6dqB2/rVjMmlHF s=; X-IronPort-AV: E=Sophos;i="6.01,180,1684800000"; d="scan'208";a="102870598" Received: from rcdn-core-7.cisco.com ([173.37.93.143]) by rcdn-iport-4.cisco.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Aug 2023 18:22:21 +0000 Received: from localhost.cisco.com ([10.193.101.253]) (authenticated bits=0) by rcdn-core-7.cisco.com (8.15.2/8.15.2) with ESMTPSA id 37HIMCar015707 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 17 Aug 2023 18:22:20 GMT From: Karan Tilak Kumar To: sebaddel@cisco.com Cc: arulponn@cisco.com, djhawar@cisco.com, gcboffa@cisco.com, mkai2@cisco.com, satishkh@cisco.com, jejb@linux.ibm.com, martin.petersen@oracle.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Karan Tilak Kumar Subject: [PATCH] scsi: fnic: Replace sgreset tag with max_tag_id Date: Thu, 17 Aug 2023 11:21:46 -0700 Message-Id: <20230817182146.229059-1-kartilak@cisco.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Authenticated-User: kartilak@cisco.com X-Outbound-SMTP-Client: 10.193.101.253, [10.193.101.253] X-Outbound-Node: rcdn-core-7.cisco.com Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org sgreset is issued with a scsi command pointer. The device reset code assumes that it was issued on a hardware queue, and calls block multiqueue layer. However, the assumption is broken, and there is no hardware queue associated with the sgreset, and this leads to a crash due to a null pointer exception. Fix the code to use the max_tag_id as a tag which does not overlap with the other tags issued by mid layer. Tested by running FC traffic for a few minutes, and by issuing sgreset on the device in parallel. Without the fix, the crash is observed right away. With this fix, no crash is observed. Reviewed-by: Sesidhar Baddela Tested-by: Karan Tilak Kumar Signed-off-by: Karan Tilak Kumar --- drivers/scsi/fnic/fnic.h | 3 ++- drivers/scsi/fnic/fnic_scsi.c | 20 +++++++++----------- 2 files changed, 11 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/fnic/fnic.h b/drivers/scsi/fnic/fnic.h index e51e92f932fa..93c68931a593 100644 --- a/drivers/scsi/fnic/fnic.h +++ b/drivers/scsi/fnic/fnic.h @@ -27,7 +27,7 @@ #define DRV_NAME "fnic" #define DRV_DESCRIPTION "Cisco FCoE HBA Driver" -#define DRV_VERSION "1.6.0.55" +#define DRV_VERSION "1.6.0.56" #define PFX DRV_NAME ": " #define DFX DRV_NAME "%d: " @@ -236,6 +236,7 @@ struct fnic { unsigned int wq_count; unsigned int cq_count; + struct mutex sgreset_mutex; struct dentry *fnic_stats_debugfs_host; struct dentry *fnic_stats_debugfs_file; struct dentry *fnic_reset_debugfs_file; diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c index be89ce96df46..185142efee3d 100644 --- a/drivers/scsi/fnic/fnic_scsi.c +++ b/drivers/scsi/fnic/fnic_scsi.c @@ -2222,7 +2222,6 @@ int fnic_device_reset(struct scsi_cmnd *sc) struct reset_stats *reset_stats; int tag = rq->tag; DECLARE_COMPLETION_ONSTACK(tm_done); - int tag_gen_flag = 0; /*to track tags allocated by fnic driver*/ bool new_sc = 0; /* Wait for rport to unblock */ @@ -2252,17 +2251,17 @@ int fnic_device_reset(struct scsi_cmnd *sc) } fnic_priv(sc)->flags = FNIC_DEVICE_RESET; - /* Allocate tag if not present */ if (unlikely(tag < 0)) { /* - * Really should fix the midlayer to pass in a proper - * request for ioctls... + * For device reset issued through sg3utils, we let + * only one LUN_RESET to go through and use a special + * tag equal to max_tag_id so that we don't have to allocate + * or free it. It won't interact with tags + * allocated by mid layer. */ - tag = fnic_scsi_host_start_tag(fnic, sc); - if (unlikely(tag == SCSI_NO_TAG)) - goto fnic_device_reset_end; - tag_gen_flag = 1; + mutex_lock(&fnic->sgreset_mutex); + tag = fnic->fnic_max_tag_id; new_sc = 1; } io_lock = fnic_io_lock_hash(fnic, sc); @@ -2434,9 +2433,8 @@ int fnic_device_reset(struct scsi_cmnd *sc) (u64)sc->cmnd[4] << 8 | sc->cmnd[5]), fnic_flags_and_state(sc)); - /* free tag if it is allocated */ - if (unlikely(tag_gen_flag)) - fnic_scsi_host_end_tag(fnic, sc); + if (new_sc) + mutex_unlock(&fnic->sgreset_mutex); FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host, "Returning from device reset %s\n",