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=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 8B88EC433E2 for ; Thu, 17 Sep 2020 00:29:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 370EB206C9 for ; Thu, 17 Sep 2020 00:29:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="PGVfvuH7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726098AbgIQA3d (ORCPT ); Wed, 16 Sep 2020 20:29:33 -0400 Received: from mout.gmx.net ([212.227.15.19]:54401 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725987AbgIQA3c (ORCPT ); Wed, 16 Sep 2020 20:29:32 -0400 X-Greylist: delayed 304 seconds by postgrey-1.27 at vger.kernel.org; Wed, 16 Sep 2020 20:29:31 EDT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1600302570; bh=mz+7DqUt7EPSV4LH/TXdVCY6AtmOXsmPgRnPaWLcpew=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=PGVfvuH72aoNr2up1L/Q+dmjbgbxsy+iglkKnqVCPRXoHld2PTtqZ4V01XY85X35H GM6dDSVfg4zl+oN37tbnE5S0B/kSzl/pZUyqgCM1HaE389CVPY//Hqg2dLeyiNklVM Ui0EVxGTtZSVxtocqHsTSgqGx3euBH7QB7pjXJp8= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1MYeQr-1jwUA32fzP-00Vcwn; Thu, 17 Sep 2020 02:24:21 +0200 Subject: Re: [PATCH v2 00/19] btrfs: add read-only support for subpage sector size To: Neal Gompa , Qu Wenruo Cc: Btrfs BTRFS , Josef Bacik , Chris Murphy References: <20200915053532.63279-1-wqu@suse.com> <6802c45f-16eb-90a3-4ad5-b3bb92dc4cbd@suse.com> From: Qu Wenruo Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAU4EEwEIADgCGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1oQAKCRDC PZHzoSX+qCY6CACd+mWu3okGwRKXju6bou+7VkqCaHTdyXwWFTsr+/0ly5nUdDtT3yEVggPJ 3VP70wjlrxUjNjFb6iIvGYxiPOrop1NGwGYvQktgRhaIhALG6rPoSSAhGNjwGVRw0km0PlIN D29BTj/lYEk+jVM1YL0QLgAE1AI3krihg/lp/fQT53wLhR8YZIF8ETXbClQG1vJ0cllPuEEv efKxRyiTSjB+PsozSvYWhXsPeJ+KKjFen7ebE5reQTPFzSHctCdPnoR/4jSPlnTlnEvLeqcD ZTuKfQe1gWrPeevQzgCtgBF/WjIOeJs41klnYzC3DymuQlmFubss0jShLOW8eSOOWhLRuQEN BFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcgaCbPEwhLj 1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj/IrRUUka 68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fNGSsRb+pK EKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0q1eW4Jrv 0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEvABEBAAGJ ATwEGAEIACYCGwwWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1rgUJCWpOfwAKCRDCPZHz oSX+qFcEB/95cs8cM1OQdE/GgOfCGxwgckMeWyzOR7bkAWW0lDVp2hpgJuxBW/gyfmtBnUai fnggx3EE3ev8HTysZU9q0h+TJwwJKGv6sUc8qcTGFDtavnnl+r6xDUY7A6GvXEsSoCEEynby 72byGeSovfq/4AWGNPBG1L61Exl+gbqfvbECP3ziXnob009+z9I4qXodHSYINfAkZkA523JG ap12LndJeLk3gfWNZfXEWyGnuciRGbqESkhIRav8ootsCIops/SqXm0/k+Kcl4gGUO/iD/T5 oagaDh0QtOd8RWSMwLxwn8uIhpH84Q4X1LadJ5NCgGa6xPP5qqRuiC+9gZqbq4Nj Message-ID: Date: Thu, 17 Sep 2020 08:24:16 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="t2SPohldi8OmUrFOIuaYXXvEh286ADwGR" X-Provags-ID: V03:K1:cK5VlPrtsb0rwugVyZQwCj8qAsvgG1Xo+yZeMkAh8F5cSiX9d6j Eu1zICDdmZiH5nWQNWBs04RE/OsbiwqWvTo1bfPqSaLtDxEDnOpEdHKzWwt3AbbG7YDXUZ0 4mIAPbu9Sa2Mr4K+sjoyYnYFRG+NQlhOVEjotabYOxLqVq4wxLxIsHLYLthowKo1GDsRsE1 Qk/RLNOvrPBJdIK0AzCxQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:z7l6FwzHhGo=:FGP56ndPjJgp5w3dlgZ30K 3iCud7xpgLtyN7kREGgVxvMqEgQjtyBYwHQhBvzi3qW9KmuuZCDvHw43R/ZDn/4e57BJA4PNB O9rqdFXl2mJZI/FuFPj+QzbImUBrTj22b3q5oQ4Pup5YW84FH+9QHTUX89odcsx0P14mOi8VC wg70EcTPmmG9CtoZKsOsX2vj2QyeC2TcA17luMVCG4f1NfwfOd4GgK9d6fDaXc896IhWTXBKb SEdlL6skXiy0lRcYC54GAhKmlnZk53YXnqWgMkgQ4FGefJxgqTjyvSp+WCJ3oPDbRCJ3GggHU oQIO/CpFkTU6CrL59C7/c2JT9cfCFERCdWRzzf9TOqqu8psaCJ0GJwknHJ61C+esz5f3NiDAG aiydXMe9TX9Em5rfE1mnVNkallSZWxfor9cgDsj+mqAbeSjjlerJzm1lehxr82v8109a8If0s 7iuqPR5ULm5K4QaeHUeCd2yHpHZRw6gcR3DR3HS07w36XsTE/ecF6pJZrEezAH9Y3GSkw7DIJ J6tsZChXJGa4dp+dfHYdpG/6PeLQelUFhylzQJid1Tdd5gsg9m++D5u3LUA5vDTW0vcvH2b1Z mtjjpMucEpMR1vkfPGKL7T/pp3Pn7bHHOz5xWJwZMwNk48VrfbLleaTW9/El/CqtExzhdsgi+ Z/e0Efi7gWIx+/RXcdEhLSwkBhw7qsgUcZ24MYOhAdW1RX9597il5KvzptG+l8sWSGz7JRpIk 2O8vUHTsjjnBWSoSxaYFc/LbC+Ggzc+psaDdqkF+5/hA1M++oe+s74XJqAmZDFBK/ju5B8qbA DMkDMP0bLjpo0/xN8b86nDBTwY8JQ2iNoCg5G88r8yJz2Mji9Wgj2MqyEvyhG/+D++5ht3uPF 13bgjvs/XNc8sr8PvCLtFO+bXe8NcqcivWK0I93VXicxH1azbAxdlQJm2ahWRNMm4KvM9OCWH Omrz7pfXMS8rfGsxBzWs3UmKsHm9DyOI/7iHb/rJ/iJzZvIrbsV8z2dPkVZycvuwbdDuuzHZv k8R9whyS5PDtaYNmm89E3Bbx9ykFMN7Y0E1xodB4I93QHhXzttqSxwCSI9giwAEY7ELX9yrhc pIDEQnrfLlawk0obOKsAJ9tWSzFvDPVFFbZ0fQd7u9tsLNcATQxTo/4Cfv2+S1JGF8d+8UZCz LO9JhucmX3TMOJryRrC67twiYQYobbF7EMVypAYzHZHpnZn/ISLBht2LSfy75v3lPQbjuDnLn YwxU6zyQq8xAZZEbddnWaQ38b7QA6v9V6oJ1Qmg== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --t2SPohldi8OmUrFOIuaYXXvEh286ADwGR Content-Type: multipart/mixed; boundary="rxJGM1gxsCcgGm9eDgrKMAIdcMRKJuovB" --rxJGM1gxsCcgGm9eDgrKMAIdcMRKJuovB Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2020/9/17 =E4=B8=8A=E5=8D=888:13, Neal Gompa wrote: > 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_= SIZE. >>>> >>>> That means, for 64K page size system, they can only use 64K sector s= ize >>>> 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,= and >>>> 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.= >> >=20 > 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. That's the plan. But not for now, since currently the subpage support is only read-only. >=20 > I guess that would be an incompat flag, no? No need for incompat flag. For older kernel they just can't mount subpage fs. Thanks, Qu >=20 >=20 >=20 > -- > =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! >=20 --rxJGM1gxsCcgGm9eDgrKMAIdcMRKJuovB-- --t2SPohldi8OmUrFOIuaYXXvEh286ADwGR Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl9irLAACgkQwj2R86El /qgwQAf+N973Mb/9jztN0qrQBpJ1IaPtoN44tP2Ym65EV0VM566uXfgO/wXtZSXV kodQRvVHgo6YzfvREgbrWWshRdNEgY1fkzYqrWFJvG2k9SHOODwQA68IUY7+knfM X78ofJc45qVya4HGNLt3kX2WLQhPzxcXrQ6lXzJLf8mijFTpz3pXDddo8l5lPWq7 HQVPDGtaz+OOacHmZITtiVkzaLqYH3XXaQh+ZMCx4FHnHKzJzUF7EQW+LJdFRuwu PQQx/qF2OQSdvZl0NVxVwxuM2/4KBhZkh+cpNiB5gK5OsnpsPXsggMXUhZyaw0CL D5qz6vFuMOt3EQ2QPFw0XykYoCgD2w== =zpp7 -----END PGP SIGNATURE----- --t2SPohldi8OmUrFOIuaYXXvEh286ADwGR--