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=-8.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 C0FD3C43461 for ; Thu, 17 Sep 2020 00:23:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 797DB221EF for ; Thu, 17 Sep 2020 00:23:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="KGmJvdIo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726004AbgIQAXA (ORCPT ); Wed, 16 Sep 2020 20:23:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725987AbgIQAW6 (ORCPT ); Wed, 16 Sep 2020 20:22:58 -0400 X-Greylist: delayed 506 seconds by postgrey-1.27 at vger.kernel.org; Wed, 16 Sep 2020 20:22:58 EDT Received: from mail-io1-xd42.google.com (mail-io1-xd42.google.com [IPv6:2607:f8b0:4864:20::d42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E73FDC06178C for ; Wed, 16 Sep 2020 17:14:31 -0700 (PDT) Received: by mail-io1-xd42.google.com with SMTP id u6so183223iow.9 for ; Wed, 16 Sep 2020 17:14:31 -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=/50w6DgCOJ3/5EqKFCUb8mTb9eEt6Fp3Z4L748cy2R4=; b=KGmJvdIo2lphpn4mbomHqK432FUkkXyF+IRnfl7mtP+WVGwZb1+oSObdqXwCfowV57 cUStlU+u6dTpqvBRBzd8d7W9a9Z3dniTFOH5r7HEXEgCoaclYZu+BQV3mvsK+rbTlYFl c36zxNG2ejeT+AyyF3aj80+dbJrL+OKGTlEy6jTqfuSwjtcfnrePyeXAgGfhRjEQKjGA 1yT7c8Q8UhIE3x37z58HIKh2ZLtyNL4f6UA9A6fxfAT+7jxVEP2pk7cz8HpuchfavEYu oYVE8b4oek0umga/gz1XcAM8p6of+pe5HusIeGRwpnadAbJXTuFwhT9qVBxdywCsZyBj xA9A== 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=/50w6DgCOJ3/5EqKFCUb8mTb9eEt6Fp3Z4L748cy2R4=; b=CKueAHKE9HjImnWYdRZ5taJaA6pWxVpDsHQKru64z38Tehfy5SMd8L6PSU1pjTGEYi JTx35eh5YQ03ofJHzetb2WDyNENnwCm/PSMT3uno7l3+WdIn8INyyCYCj6bUELdz9WT6 eW6+cIf+26Y2mJUtBGXDdZ7yirojfGEphrLDV91zaV5jW3XlVooAQDTo3uIvg9/VEV67 akKEgX+4APTtx8YB1m35MV6VUpRi2pfAAj+TfFutm7PgEzkFsQxMEKSaOJGrmDMD6W3I ye4h0INEfFxCTvPYZTY6OUDn9s7fxiz0X3eZP+TMZING7wo5MmpG8Iye1NxL5DN9AC1s CBGQ== X-Gm-Message-State: AOAM533XQzAr4BvhYH3jXsoiJ3RfXiXcSZIkDamiCEQeuMMWWXbKIQmz 0OFyJ7igFs45efOmeNV4Tz1pofj4MOJw2FMxyDLcZy3sYiwuSA== X-Google-Smtp-Source: ABdhPJzJkrP36AETv7qYyKr06ky8rlPNG30t9tkgFzv0tsR7W4zl8C8zUs7VAv7XFKIjtWXN/MytIU9VORac0SZN7L0= X-Received: by 2002:a6b:610d:: with SMTP id v13mr21150310iob.189.1600301670997; Wed, 16 Sep 2020 17:14:30 -0700 (PDT) MIME-Version: 1.0 References: <20200915053532.63279-1-wqu@suse.com> <6802c45f-16eb-90a3-4ad5-b3bb92dc4cbd@suse.com> In-Reply-To: <6802c45f-16eb-90a3-4ad5-b3bb92dc4cbd@suse.com> From: Neal Gompa Date: Wed, 16 Sep 2020 20:13:55 -0400 Message-ID: Subject: Re: [PATCH v2 00/19] btrfs: add read-only support for subpage sector size To: Qu Wenruo Cc: Btrfs BTRFS , Josef Bacik , Chris Murphy Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Wed, Sep 16, 2020 at 8:03 PM Qu Wenruo wrote: > > > > On 2020/9/17 =E4=B8=8A=E5=8D=8812:18, Neal Gompa wrote: > > On Tue, Sep 15, 2020 at 1:36 AM Qu Wenruo wrote: > >> > >> Patches can be fetched from github: > >> https://github.com/adam900710/linux/tree/subpage > >> > >> Currently btrfs only allows to mount fs with sectorsize =3D=3D PAGE_SI= ZE. > >> > >> That means, for 64K page size system, they can only use 64K sector siz= e > >> fs. > >> This brings a big compatible problem for btrfs. > >> > >> This patch is going to slightly solve the problem by, allowing 64K > >> system to mount 4K sectorsize fs in read-only mode. > >> > >> The main objective here, is to remove the blockage in the code base, a= nd > >> pave the road to full RW mount support. > >> > > > > Is there a reason we don't include a patch in here to just hardwire > > the block size to 4K going forward? > > > > Did you mean to make 4K sector size the hard requirement? > > That would make existing 64K sector size fs unable to be mounted then. > I mean, make the 64K variant a legacy one and force 4K for all new filesystems. That then simplifies this work to making it mountable and usable as a legacy filesystem format. I guess that would be an incompat flag, no? -- =E7=9C=9F=E5=AE=9F=E3=81=AF=E3=81=84=E3=81=A4=E3=82=82=E4=B8=80=E3=81=A4=EF= =BC=81/ Always, there's only one truth!