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=-2.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_MUTT 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 6DE6DC43219 for ; Tue, 30 Apr 2019 15:47:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CC0C20652 for ; Tue, 30 Apr 2019 15:47:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="tvEDCQT1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725976AbfD3Prq (ORCPT ); Tue, 30 Apr 2019 11:47:46 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:58612 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725906AbfD3Prq (ORCPT ); Tue, 30 Apr 2019 11:47:46 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3UFiMc8138912; Tue, 30 Apr 2019 15:47:11 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 : in-reply-to; s=corp-2018-07-02; bh=ORetv7bkfUVIk8T/lSppKI2JhxisrSy4qmjBLBLnjjU=; b=tvEDCQT1n9op9yMFG/x01to6k569aBRL49XaMOFPdv8GtdoR9uOUn0CPzDt97v32z2wp pUmhkFrsj/WbnsZMwWThi4kf2fNpqiEHCIlQUBcDuqXv+gN9TYHs4AAJz5M70TPdrnOQ B+tCGls+HJ6lQN7+eNEcI4lVtu3U22tYIvzfy0BX0MzFiQsEP9LI6eCzqH7XLzjc4z/a 6heTrXV4DQhnSzlFy0u/bSzYweSqFFZ4q6gX5qOOi6t2HzDjj1PwrwEWzKoQ5xv2T8Gh shuAgbuZBKc6KnctZOUgKwfdD8vAG3P3XdeEMXpWkqaim5VZO3EsQI7W2fUnW0aNQk1U EQ== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2130.oracle.com with ESMTP id 2s4ckddnpe-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Apr 2019 15:47:11 +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 x3UFl1sv104991; Tue, 30 Apr 2019 15:47:10 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3020.oracle.com with ESMTP id 2s5u512dx3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Apr 2019 15:47:10 +0000 Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x3UFl8PZ025334; Tue, 30 Apr 2019 15:47:09 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 30 Apr 2019 08:47:08 -0700 Date: Tue, 30 Apr 2019 08:47:07 -0700 From: "Darrick J. Wong" To: Andreas Gruenbacher Cc: cluster-devel , Christoph Hellwig , Bob Peterson , Jan Kara , Dave Chinner , Ross Lagerwall , Mark Syms , Edwin =?iso-8859-1?B?VPZy9ms=?= , linux-fsdevel , linux-mm@kvack.org Subject: Re: [PATCH v7 5/5] gfs2: Fix iomap write page reclaim deadlock Message-ID: <20190430154707.GG5200@magnolia> References: <20190429220934.10415-1-agruenba@redhat.com> <20190429220934.10415-6-agruenba@redhat.com> <20190430153256.GF5200@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9243 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=8.0.1-1810050000 definitions=main-1904300096 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9243 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=8.0.1-1810050000 definitions=main-1904300097 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Apr 30, 2019 at 05:39:28PM +0200, Andreas Gruenbacher wrote: > On Tue, 30 Apr 2019 at 17:33, Darrick J. Wong wrote: > > On Tue, Apr 30, 2019 at 12:09:34AM +0200, Andreas Gruenbacher wrote: > > > Since commit 64bc06bb32ee ("gfs2: iomap buffered write support"), gfs2 is doing > > > buffered writes by starting a transaction in iomap_begin, writing a range of > > > pages, and ending that transaction in iomap_end. This approach suffers from > > > two problems: > > > > > > (1) Any allocations necessary for the write are done in iomap_begin, so when > > > the data aren't journaled, there is no need for keeping the transaction open > > > until iomap_end. > > > > > > (2) Transactions keep the gfs2 log flush lock held. When > > > iomap_file_buffered_write calls balance_dirty_pages, this can end up calling > > > gfs2_write_inode, which will try to flush the log. This requires taking the > > > log flush lock which is already held, resulting in a deadlock. > > > > /me wonders how holding the log flush lock doesn't seriously limit > > performance, but gfs2 isn't my fight so I'll set that aside and assume > > that a patch S-o-B'd by both maintainers is ok. :) > > This only affects inline and journaled data, not standard writes, so > it's not quite as bad as it looks. Ah, ok. > > How should we merge this patch #5? It doesn't touch fs/iomap.c itself, > > so do you want me to pull it into the iomap branch along with the > > previous four patches? That would be fine with me (and easier than a > > multi-tree merge mess)... > > I'd prefer to get this merged via the gfs2 tree once the iomap fixes > have been pulled. Ok, I'll take the first four patches through the iomap branch and cc you on the pull request. --D > > Thanks, > Andreas