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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 1587DC43219 for ; Wed, 1 May 2019 15:36:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D989D208C3 for ; Wed, 1 May 2019 15:36:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LP9NRNoA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726586AbfEAPgJ (ORCPT ); Wed, 1 May 2019 11:36:09 -0400 Received: from mail-pl1-f181.google.com ([209.85.214.181]:32981 "EHLO mail-pl1-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726579AbfEAPgJ (ORCPT ); Wed, 1 May 2019 11:36:09 -0400 Received: by mail-pl1-f181.google.com with SMTP id y3so7499621plp.0 for ; Wed, 01 May 2019 08:36:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=swugMe8TeMhTfpmnJWAJYHeG1IlveAd0mG2zpm5gwAc=; b=LP9NRNoAwV9o/wOGUluwaFXEkB9k0nhVwJlOQfDw2m+V6AstxJdMn0sDE2RsMm7tis MyIs9TtE4REHRLp/qNkIKu6NEBlJzVoGDk0TX1B8T4NxiK6E5//kC8KlfGJFHHg0kXjz u9Iggoy0wijsLP5ByI9Yyl/C0y07QBfCwu5S/GNrdWeifqb+sRv90khV1d5Ni9lFEjXL ZUsnsyCKVOtJCyY6tw+DS92ySmBQihO79QL/HyKrixqzH+54ZixZonjuz/lMYBfiRvcz Yfvnic5XfJIiQj7Ge3DQzsRRO+GrybBiMZkGMFgqYycF/bvn925A9y7v6T7HUdlDtsw4 0xlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=swugMe8TeMhTfpmnJWAJYHeG1IlveAd0mG2zpm5gwAc=; b=c0WcCOveAmHThhAT9FWShSCMth6CNEGHnskTD6FZzz+vKVqtoy1cAHc7KjkRQZgO0e s8y423a5Flth3JjwNyGgz29XpZoKRxJoR9XM/52AK/GREcuwBrgtfvEjQQlS0na3MDbG q6ZpK436LQ5Kb5cfz9vbN0JaY0R0fVJzZpuXEHFeKf+L7VD8wArmTZABZgrZk2uvY6+E UGZOAhGYbh4D3CCQAFC9T5EmGDywMgcwLg2JcDnbe8x02lvngej9FTsuB4GeDIV+KiDn MfCMkbL7m5tU1NKSL6Kqk1up7f+ibWmjMfDFYyau8MdW6ZCpCNtU8uBQCsCF3557vvGx BYVw== X-Gm-Message-State: APjAAAWjWCBXj02zEWg5qL40Fcf0WHevuJj8Ff05idbC5NbZsIeWBq95 SMrXMBPpOQ93VKeU1MjDFuRIE3UUK/arhP8cg8QYHfAh X-Google-Smtp-Source: APXvYqyO6IHkXo9FJCnvezNoBeS4P6MmQOQ9leW9aiNzauHyBHZ6ZYca7+NRguMP5qq6DaNsVEhLbTighGs1QHy8HWQ= X-Received: by 2002:a17:902:8609:: with SMTP id f9mr10715537plo.32.1556724968277; Wed, 01 May 2019 08:36:08 -0700 (PDT) MIME-Version: 1.0 References: <1666985748.6396792.1556614132673.JavaMail.zimbra@redhat.com> <151404631.6398428.1556614866154.JavaMail.zimbra@redhat.com> In-Reply-To: <151404631.6398428.1556614866154.JavaMail.zimbra@redhat.com> From: Steve French Date: Wed, 1 May 2019 10:35:54 -0500 Message-ID: Subject: Re: Memory alignment requirement for Direct/IO To: Xiaoli Feng Cc: CIFS Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org I would expect direct i/o to work with unaligned reads over SMB3 mounts. Let me know if you see different behavior to any servers. On Tue, Apr 30, 2019 at 4:01 AM Xiaoli Feng wrote: > > Hello, > > I setup samba server in upstream and mount it in local with cache=3Dnone= ,vers=3D3.11. Then test > the Direct/IO function like this: > > fd=3Dopen(fname, O_DIRECT | O_RDWR | O_CREAT, 0666)) > lseek(fd, 0, SEEK_SET); > read(fd, buf, 1); > > For local filesystem such as XFS, "read" will be failed because XFS has 5= 12Byte memory aligment > for Direct/IO. But it's success for cifs. I don't know if it's expected. = Could anybody tell me > more about Direct/IO for cifs? > > Thanks. > > -- > Best regards! > XiaoLi Feng =E5=86=AF=E5=B0=8F=E4=B8=BD > > Red Hat Software (Beijing) Co.,Ltd > filesystem-qe Team > IRC:xifeng=EF=BC=8C#channel: fs-qe > Tel:+86-10-8388112 > 9/F, Raycom --=20 Thanks, Steve