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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 83914C10F27 for ; Tue, 10 Mar 2020 19:31:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53BCE21D56 for ; Tue, 10 Mar 2020 19:31:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b="Auk/J/am" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727334AbgCJTb6 (ORCPT ); Tue, 10 Mar 2020 15:31:58 -0400 Received: from mail-il1-f193.google.com ([209.85.166.193]:34769 "EHLO mail-il1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726729AbgCJTb5 (ORCPT ); Tue, 10 Mar 2020 15:31:57 -0400 Received: by mail-il1-f193.google.com with SMTP id c8so12733948ilm.1 for ; Tue, 10 Mar 2020 12:31:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=0QsMHMToALTgigyVVitR0QGzkqjZRHN3wRK9R0WkFcg=; b=Auk/J/am7PnSkti7DnDeBTBkoI7EdkOeiXxOafA83iFtNlXEfJCh8HA0llJSykN0lU F3K3PX0+eGlrLpw9xVldfbGWlBeibwiL4+JP4oW3J6fT8IYoEUYX6QU+hSAzqc2x9YAS wcqf5w4LictNkY4z6rP056PjahcGRfLxvhsqs= 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; bh=0QsMHMToALTgigyVVitR0QGzkqjZRHN3wRK9R0WkFcg=; b=b+UuTyaYCulzScydlwnGOZUoJ52sz2YjuUCqKu+692d87w+YwHrppRrcJBqX+W93fU gAgiffcHNnAhWmGPZQPCy1MN3go0ZxEfvr3s1z5/Iwdy2txFFCnwBGULpR6HuBvlhb8m Sw601cIg69ZTDsYIF+0p3uJ9e7eThkgDjwl37wt9Qcew5gPGJNXadONHRC+ZTWDpIK09 xq6QKK8AnXDjoQb6uci+wId37AulfboO096eAFxF7tHohCFmZowYP2Rhda8L/ZA1U/pB yWM9rpy7zu8fBsdiUdHxEFuoUEXwAGgKRG/ILhkVxRszGLz8qmmUZ/cNHcbAKL6759bm 36Gg== X-Gm-Message-State: ANhLgQ2XztQJCEpacQHzFuULjiD8caVsqLS/O+0XUrBfWWKygmhi6kC2 g2V/GsKs0U9iCUDNlCworMn6YMwhqA+nbUD00h1UIg== X-Google-Smtp-Source: ADFU+vsFfd6CjN4MRb2Z8XflZdOXGt54+OVcpgTdjMhSBiJTAUfuWfnL1e0wV+iTRlceDUTwZKIzKC3VAbxB+0sXKGs= X-Received: by 2002:a05:6e02:f43:: with SMTP id y3mr21752506ilj.174.1583868715742; Tue, 10 Mar 2020 12:31:55 -0700 (PDT) MIME-Version: 1.0 References: <20200304165845.3081-1-vgoyal@redhat.com> <20200304165845.3081-12-vgoyal@redhat.com> In-Reply-To: <20200304165845.3081-12-vgoyal@redhat.com> From: Miklos Szeredi Date: Tue, 10 Mar 2020 20:31:44 +0100 Message-ID: Subject: Re: [PATCH 11/20] fuse: implement FUSE_INIT map_alignment field To: Vivek Goyal Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, virtio-fs@redhat.com, Stefan Hajnoczi , "Dr. David Alan Gilbert" , "Michael S. Tsirkin" Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Mar 4, 2020 at 5:59 PM Vivek Goyal wrote: > > The device communicates FUSE_SETUPMAPPING/FUSE_REMOVMAPPING alignment > constraints via the FUST_INIT map_alignment field. Parse this field and > ensure our DAX mappings meet the alignment constraints. > > We don't actually align anything differently since our mappings are > already 2MB aligned. Just check the value when the connection is > established. If it becomes necessary to honor arbitrary alignments in > the future we'll have to adjust how mappings are sized. > > The upshot of this commit is that we can be confident that mappings will > work even when emulating x86 on Power and similar combinations where the > host page sizes are different. > > Signed-off-by: Stefan Hajnoczi > Signed-off-by: Vivek Goyal Reviewed-by: Miklos Szeredi