From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934108AbcECP7k (ORCPT ); Tue, 3 May 2016 11:59:40 -0400 Received: from mail-bn1on0144.outbound.protection.outlook.com ([157.56.110.144]:40576 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933748AbcECP7D (ORCPT ); Tue, 3 May 2016 11:59:03 -0400 Authentication-Results: infradead.org; dkim=none (message not signed) header.d=none;infradead.org; dmarc=none action=none header.from=hpe.com; Message-ID: <5728CAB6.4050101@hpe.com> Date: Tue, 3 May 2016 11:58:46 -0400 From: Waiman Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.12) Gecko/20130109 Thunderbird/10.0.12 MIME-Version: 1.0 To: Christoph Hellwig CC: "Theodore Ts'o" , Andreas Dilger , , , Scott J Norton , Douglas Hatch Subject: Re: [RFC PATCH] ext4: Don't release mutex for DAX write References: <1462219138-44089-1-git-send-email-Waiman.Long@hpe.com> <20160503084343.GA31363@infradead.org> In-Reply-To: <20160503084343.GA31363@infradead.org> Content-Type: text/plain; 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The same issue also exists for ext2 and XFS so it > needs to be solved at a higher level. I think the DAX code was in the DIO path because it didn't want to use buffer cache at all. Taking DAX out from DIO will mean having a third mode of doing I/O which is similar to DIO in certain ways, but not exactly the same. There will be a certain amount of code duplication in this case. Do we really want to do that? As for the locking problem, xfs doesn't seem to have issue as it uses a rwsem in the xfs inode for synchronization. I haven't looked into the ext2 code to see if there is any issue there. Cheers, Longman