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[2620:137:e000::1:20]) by mx.google.com with ESMTP id g3-20020a056a0023c300b0052e75c5055bsi11294700pfc.192.2022.08.08.07.59.11; Mon, 08 Aug 2022 07:59:31 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=TskIBFaX; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237965AbiHHOu1 (ORCPT + 99 others); Mon, 8 Aug 2022 10:50:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233836AbiHHOuY (ORCPT ); Mon, 8 Aug 2022 10:50:24 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 69CBFF16 for ; Mon, 8 Aug 2022 07:50:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1659970222; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=zA8npM3OywHm42HT0c3n4OurYu0szJDVE3++UGlXPIA=; b=TskIBFaX0UgeU83zovdn5Qb8Z+xOL24FAoYssuI9IxVc6DHIjmqIrjn77OhceMN5mdJuoW nZEgwVVS0kg1RFIPC82IPjjIzeL8SJp62W2HQ0KPaU2m4yfLBRUuWLAa9Lu6IT6Ur28f6P 0B/T1jzWUMXsKO5f/RKiyWxFURZXqOU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-482-htAu44AoOqG8R2UP2bdCDQ-1; Mon, 08 Aug 2022 10:50:19 -0400 X-MC-Unique: htAu44AoOqG8R2UP2bdCDQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E4D78858EED; Mon, 8 Aug 2022 14:50:14 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (file01.intranet.prod.int.rdu2.redhat.com [10.11.5.7]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BAD2E18ECC; Mon, 8 Aug 2022 14:50:13 +0000 (UTC) Received: from file01.intranet.prod.int.rdu2.redhat.com (localhost [127.0.0.1]) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4) with ESMTP id 278EoDG2013274; Mon, 8 Aug 2022 10:50:13 -0400 Received: from localhost (mpatocka@localhost) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4/Submit) with ESMTP id 278EoAkb013269; Mon, 8 Aug 2022 10:50:12 -0400 X-Authentication-Warning: file01.intranet.prod.int.rdu2.redhat.com: mpatocka owned process doing -bs Date: Mon, 8 Aug 2022 10:50:10 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Dan Carpenter , Mike Snitzer , dm-devel@redhat.com cc: kbuild@lists.01.org, lkp@intel.com, kbuild-all@lists.01.org, Mike Snitzer , linux-kernel@vger.kernel.org Subject: [PATCH] dm-writecache: drop the lock on an 'impossible' path In-Reply-To: <202208050301.roHRxc6O-lkp@intel.com> Message-ID: References: <202208050301.roHRxc6O-lkp@intel.com> User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 5 Aug 2022, Dan Carpenter wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > head: b44f2fd87919b5ae6e1756d4c7ba2cbba22238e1 > commit: df699cc16ea5ef93a917676dcdd4376e02860ad5 dm writecache: report invalid return from writecache_map helpers > config: arc-randconfig-m041-20220804 (https://download.01.org/0day-ci/archive/20220805/202208050301.roHRxc6O-lkp@intel.com/config) > compiler: arc-elf-gcc (GCC) 12.1.0 > > If you fix the issue, kindly add following tag where applicable > Reported-by: kernel test robot > Reported-by: Dan Carpenter > > smatch warnings: > drivers/md/dm-writecache.c:1554 writecache_map() warn: inconsistent returns '&wc->lock'. Hi Here I'm sending a patch for this warning. Mikulas From: Mikulas Patocka There's a smatch warning "inconsistent returns '&wc->lock'" in dm-writecache. The reason for the warning is that the function writecache_map doesn't drop the lock on the impossible path. This patch adds wc_unlock after the BUG statement (so that it will be compiled-away anyway) to fix the warning. Signed-off-by: Mikulas Patocka Reported-by: kernel test robot Reported-by: Dan Carpenter Index: linux-2.6/drivers/md/dm-writecache.c =================================================================== --- linux-2.6.orig/drivers/md/dm-writecache.c +++ linux-2.6/drivers/md/dm-writecache.c @@ -1598,7 +1598,8 @@ done: default: BUG(); - return -1; + wc_unlock(wc); + return DM_MAPIO_KILL; } }