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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 EE168C04AA7 for ; Mon, 13 May 2019 17:32:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CCFE62084A for ; Mon, 13 May 2019 17:32:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730262AbfEMRcl (ORCPT ); Mon, 13 May 2019 13:32:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42674 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728708AbfEMRck (ORCPT ); Mon, 13 May 2019 13:32:40 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8EF1530832E3; Mon, 13 May 2019 17:32:35 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 36EDE9CC8; Mon, 13 May 2019 17:32:33 +0000 (UTC) Received: from zmail21.collab.prod.int.phx2.redhat.com (zmail21.collab.prod.int.phx2.redhat.com [10.5.83.24]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 7495018089CA; Mon, 13 May 2019 17:32:28 +0000 (UTC) Date: Mon, 13 May 2019 13:32:28 -0400 (EDT) From: Pankaj Gupta To: Dan Williams Cc: cohuck@redhat.com, Jan Kara , KVM list , "Michael S. Tsirkin" , Jason Wang , david , Qemu Developers , virtualization@lists.linux-foundation.org, Andreas Dilger , Ross Zwisler , Andrea Arcangeli , Dave Jiang , jstaron@google.com, linux-nvdimm , Vishal L Verma , David Hildenbrand , Matthew Wilcox , Christoph Hellwig , Linux ACPI , jmoyer , linux-ext4 , Len Brown , Adam Borowski , Rik van Riel , yuval shaia , Stefan Hajnoczi , Paolo Bonzini , lcapitulino@redhat.com, Kevin Wolf , Nitesh Narayan Lal , Theodore Ts'o , Xiao Guangrong , "Darrick J. Wong" , "Rafael J. Wysocki" , Linux Kernel Mailing List , linux-xfs , linux-fsdevel , Igor Mammedov Message-ID: <116369545.28425569.1557768748009.JavaMail.zimbra@redhat.com> In-Reply-To: <2003480558.28042237.1557537797923.JavaMail.zimbra@redhat.com> References: <20190510155202.14737-1-pagupta@redhat.com> <20190510155202.14737-4-pagupta@redhat.com> <864186878.28040999.1557535549792.JavaMail.zimbra@redhat.com> <2003480558.28042237.1557537797923.JavaMail.zimbra@redhat.com> Subject: Re: [Qemu-devel] [PATCH v8 3/6] libnvdimm: add dax_dev sync flag MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.65.16.148, 10.4.196.23, 10.5.101.130, 10.4.195.13] Thread-Topic: libnvdimm: add dax_dev sync flag Thread-Index: ptJfczfofLn7Sapjrtn0VT/vVA1TgWbBtP+u X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Mon, 13 May 2019 17:32:40 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi Dan, While testing device mapper with DAX, I faced a bug with the commit: commit ad428cdb525a97d15c0349fdc80f3d58befb50df Author: Dan Williams Date: Wed Feb 20 21:12:50 2019 -0800 When I reverted the condition to old code[1] it worked for me. I am thinking when we map two different devices (e.g with device mapper), will start & end pfn still point to same pgmap? Or there is something else which I am missing here. Note: I tested only EXT4. [1] - if (pgmap && pgmap->type == MEMORY_DEVICE_FS_DAX) + end_pgmap = get_dev_pagemap(pfn_t_to_pfn(end_pfn), NULL); + if (pgmap && pgmap == end_pgmap && pgmap->type == MEMORY_DEVICE_FS_DAX + && pfn_t_to_page(pfn)->pgmap == pgmap + && pfn_t_to_page(end_pfn)->pgmap == pgmap + && pfn_t_to_pfn(pfn) == PHYS_PFN(__pa(kaddr)) + && pfn_t_to_pfn(end_pfn) == PHYS_PFN(__pa(end_kaddr))) dax_enabled = true; put_dev_pagemap(pgmap); Thanks, Pankaj