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=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 EC31CC04A6B for ; Sat, 11 May 2019 01:24:13 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C19382184C for ; Sat, 11 May 2019 01:24:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C19382184C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:52321 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hPGkH-0002kV-3h for qemu-devel@archiver.kernel.org; Fri, 10 May 2019 21:24:13 -0400 Received: from eggs.gnu.org ([209.51.188.92]:50657) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hPGjS-0002RY-DT for qemu-devel@nongnu.org; Fri, 10 May 2019 21:23:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hPGjR-0006gB-D4 for qemu-devel@nongnu.org; Fri, 10 May 2019 21:23:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40818) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hPGjR-0006fa-5N for qemu-devel@nongnu.org; Fri, 10 May 2019 21:23:21 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 217C2308FC4E; Sat, 11 May 2019 01:23:19 +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 E0D66100E9FF; Sat, 11 May 2019 01:23:18 +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 676DA18089CA; Sat, 11 May 2019 01:23:18 +0000 (UTC) Date: Fri, 10 May 2019 21:23:17 -0400 (EDT) From: Pankaj Gupta To: Dan Williams Message-ID: <2003480558.28042237.1557537797923.JavaMail.zimbra@redhat.com> In-Reply-To: References: <20190510155202.14737-1-pagupta@redhat.com> <20190510155202.14737-4-pagupta@redhat.com> <864186878.28040999.1557535549792.JavaMail.zimbra@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.116.28, 10.4.195.22] Thread-Topic: libnvdimm: add dax_dev sync flag Thread-Index: ptJfczfofLn7Sapjrtn0VT/vVA1TgQ== X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.43]); Sat, 11 May 2019 01:23:19 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v8 3/6] libnvdimm: add dax_dev sync flag X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: 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 , Igor Mammedov , lcapitulino@redhat.com, Kevin Wolf , Nitesh Narayan Lal , Theodore Ts'o , Xiao Guangrong , cohuck@redhat.com, "Rafael J. Wysocki" , Linux Kernel Mailing List , linux-xfs , linux-fsdevel , Paolo Bonzini , "Darrick J. Wong" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" > > > > > > > > This patch adds 'DAXDEV_SYNC' flag which is set > > > > for nd_region doing synchronous flush. This later > > > > is used to disable MAP_SYNC functionality for > > > > ext4 & xfs filesystem for devices don't support > > > > synchronous flush. > > > > > > > > Signed-off-by: Pankaj Gupta > > > > --- > > > > drivers/dax/bus.c | 2 +- > > > > drivers/dax/super.c | 13 ++++++++++++- > > > > drivers/md/dm.c | 3 ++- > > > > drivers/nvdimm/pmem.c | 5 ++++- > > > > drivers/nvdimm/region_devs.c | 7 +++++++ > > > > include/linux/dax.h | 8 ++++++-- > > > > include/linux/libnvdimm.h | 1 + > > > > 7 files changed, 33 insertions(+), 6 deletions(-) > > > [..] > > > > diff --git a/drivers/md/dm.c b/drivers/md/dm.c > > > > index 043f0761e4a0..ee007b75d9fd 100644 > > > > --- a/drivers/md/dm.c > > > > +++ b/drivers/md/dm.c > > > > @@ -1969,7 +1969,8 @@ static struct mapped_device *alloc_dev(int minor) > > > > sprintf(md->disk->disk_name, "dm-%d", minor); > > > > > > > > if (IS_ENABLED(CONFIG_DAX_DRIVER)) { > > > > - dax_dev = alloc_dax(md, md->disk->disk_name, > > > > &dm_dax_ops); > > > > + dax_dev = alloc_dax(md, md->disk->disk_name, > > > > &dm_dax_ops, > > > > + > > > > DAXDEV_F_SYNC); > > > > > > Apologies for not realizing this until now, but this is broken. > > > Imaging a device-mapper configuration composed of both 'async' > > > virtio-pmem and 'sync' pmem. The 'sync' flag needs to be unified > > > across all members. I would change this argument to '0' and then > > > arrange for it to be set at dm_table_supports_dax() time after > > > validating that all components support synchronous dax. > > > > o.k. Need to set 'DAXDEV_F_SYNC' flag after verifying all the target > > components support synchronous DAX. > > > > Just a question, If device mapper configuration have composed of both > > virtio-pmem or pmem devices, we want to configure device mapper for async > > flush? > > If it's composed of both then, yes, it needs to be async flush at the > device-mapper level. Otherwise MAP_SYNC will succeed and fail to > trigger fsync on the host file when necessary for the virtio-pmem > backed portion of the device-mapper device. o.k. Agree. Thanks you, Pankaj > >