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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_SANE_1 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 DA507C3A59F for ; Thu, 29 Aug 2019 15:58:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7F1C2173E for ; Thu, 29 Aug 2019 15:58:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="A/DtKC7R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726739AbfH2P61 (ORCPT ); Thu, 29 Aug 2019 11:58:27 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:47560 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726283AbfH2P60 (ORCPT ); Thu, 29 Aug 2019 11:58:26 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x7TFv1QD048799; Thu, 29 Aug 2019 15:58:21 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : content-transfer-encoding : in-reply-to; s=corp-2019-08-05; bh=lMW6N2bwmogq9O0bgtjDn1mqGzCNO70KGvYTDD6sG6o=; b=A/DtKC7RuoOUO3Y/WDVC5XPyZiAxXzWYcXBsUJ4sY9vLHthBcq0FxAYeEGVmuXz8VVXt ILhcl50EgveLFLSSFhGPsJ2/cpOs3a2V2a2firZi338NKvw3vTqAP+jZGz4psAhGKEx3 0SKrnCZCViny8HTHxoiga55Npm4NW7Ql9SRGFN2tFNQJccL7+pSFqKthOb5loBDn/BDb iUdmW+jZU90k4lqCZJn5aF99Mx0bWvuoviB8tvxwcefh04x57AXUuQNvM0aBkXCB+gIV fR2pVjtlotNIbYE6obF7k4glZ0wf3+cmnB3MXufGNv6NBJNsMqHlhJyc8ZI/nSNtw5Ld sQ== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 2uphcyg97y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Aug 2019 15:58:21 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x7TFicpw049243; Thu, 29 Aug 2019 15:58:20 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3020.oracle.com with ESMTP id 2untev8ewu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Aug 2019 15:58:20 +0000 Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x7TFwJSt021258; Thu, 29 Aug 2019 15:58:20 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 29 Aug 2019 15:58:19 +0000 Date: Thu, 29 Aug 2019 08:58:18 -0700 From: "Darrick J. Wong" To: Austin Kim Cc: Christoph Hellwig , linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] xfs: Use WARN_ON rather than BUG() for bailout mount-operation Message-ID: <20190829155818.GF5354@magnolia> References: <20190828064749.GA165571@LGEARND20B15> <20190829075655.GD18966@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9364 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908290168 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9364 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908290168 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Thu, Aug 29, 2019 at 09:59:17PM +0900, Austin Kim wrote: > 2019년 8월 29일 (목) 오후 4:56, Christoph Hellwig 님이 작성: > > > > On Wed, Aug 28, 2019 at 03:47:49PM +0900, Austin Kim wrote: > > > If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed. > > > However, the bailout for mount is no longer proceeding. > > > > > > For this reason, using WARN_ON rather than BUG() could prevent this situation. > > > --- > > > fs/xfs/xfs_mount.c | 3 +-- > > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > > > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c > > > index 322da69..10fe000 100644 > > > --- a/fs/xfs/xfs_mount.c > > > +++ b/fs/xfs/xfs_mount.c > > > @@ -213,8 +213,7 @@ xfs_initialize_perag( > > > goto out_hash_destroy; > > > > > > spin_lock(&mp->m_perag_lock); > > > - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) { > > > - BUG(); > > > + if (WARN_ON(radix_tree_insert(&mp->m_perag_tree, index, pag))){ > > > > Please make this a WARN_ON_ONCE so that we don't see a flodding of > > messages in case of this error. > > > Hello, Mr. Christoph > Thanks for good feedback. > If the kernel log is flooded with error message, as you pointed out, > it may cause other side-effect.(e.g: system non-responsive or lockup) > > To. Mr. Darrick J. Wong > If you or other kernel developers do not disagree with the > idea(WARN_ON_ONCE instead of WARN_ON), > do I have to resend the patch with new revision? Yes, and please add your Signed-off-by in the new revision. --D > The title, the commit message and patch might be changed as followings; > ====== > xfs: Use WARN_ON_ONCE rather than BUG() for bailout mount-operation > > If the CONFIG_BUG is enabled, BUG() is executed and then system is crashed. > However, the bailout for mount is no longer proceeding. > > For this reason, using WARN_ON_ONCE rather than BUG() could prevent > this situation. > > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c > index 322da69..d831c13 100644 > --- a/fs/xfs/xfs_mount.c > +++ b/fs/xfs/xfs_mount.c > @@ -213,8 +213,7 @@ xfs_initialize_perag( > goto out_hash_destroy; > > spin_lock(&mp->m_perag_lock); > - if (radix_tree_insert(&mp->m_perag_tree, index, pag)) { > - BUG(); > + if (WARN_ON_ONCE(radix_tree_insert(&mp->m_perag_tree, > index, pag))) { > spin_unlock(&mp->m_perag_lock); > radix_tree_preload_end(); > error = -EEXIST; > ====== > > BR, > Guillermo Austin Kim