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=-2.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 50F03C07E9A for ; Wed, 14 Jul 2021 06:05:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28E7561361 for ; Wed, 14 Jul 2021 06:05:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238012AbhGNGIp (ORCPT ); Wed, 14 Jul 2021 02:08:45 -0400 Received: from mout.gmx.net ([212.227.17.21]:39905 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237946AbhGNGIo (ORCPT ); Wed, 14 Jul 2021 02:08:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1626242750; bh=aBUdDV5NQB0B5dnG/dXJ1JRvaW0MDXxWAyCPjnBvkLQ=; h=X-UI-Sender-Class:To:Cc:References:From:Subject:Date:In-Reply-To; b=Ujrkvh+CgC95+EOEZCsh3dTlR0/fwAVmzgjt50OFW0FJ9oObe5O9H1BgwECfJx+um 2iuqc/s3V3C/UyPCOTFI1dQL1WChTe1hAlDFazZo/ZooGVIMSPeulb/vvqNQAauoIc qSavfSVbS3fT7r/4kUacxaqvxdNu6SharWtQ6Gpg= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([45.77.180.217]) by mail.gmx.net (mrgmx104 [212.227.17.174]) with ESMTPSA (Nemesis) id 1MbAci-1lSHKf21N2-00bdfe; Wed, 14 Jul 2021 08:05:50 +0200 To: Chris Murphy Cc: DanglingPointer , Btrfs BTRFS References: <63396688-0dc7-17c5-a830-5893b030a30f@gmail.com> <86f0624a-cba4-58a3-0a80-460d3f12e8b3@gmx.com> From: Qu Wenruo Subject: Re: migrating to space_cache=2 and btrfs userspace commands Message-ID: <889c88ad-f51a-5b1f-3613-0b78af77477c@gmx.com> Date: Wed, 14 Jul 2021 14:05:39 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:Ss2ZPlr6Ww19x6czgx+h5nhCiPfCm62V9/yN7KRO+iSt5KvSXFz ALbV3m0amUHBkRULow0grWYymJLcIymf29HgS/OFudUgfd6+Gr9dvmh+HSExeqNuJvHADde 6RB2MVtbijfgvMrddE3uYgR7VHxw9PieN1sD6MsNFZeyh2Yz4v1bFvVKs/GTTnsIL/FSt1N a04fAiXlgtE9WpJehsmsw== X-UI-Out-Filterresults: notjunk:1;V03:K0:0IdmLlmQbcU=:9kRFRIDusrgEgyfXmOEVND FV+53+jRmtBCiW5w3rgC88ZAq/Vyp4WLv/8yX9w4a8QcwIOe5c8DETNMp2MNLkJmME48WZQKo Yodg3Bqs7wzwEuLTtbVQirZDi72tH6TWNZcsM0tBGUbd6FgcGJVqWt9oVaKVc7jgAlWtkEjzZ to+7Rm5KttSS3+zbparZBDxwJt432reJCt+S9bYOxkYJH+I4SSMBEMlXle8mtDzC/EyYcCKEx Kaiym3ToXHy8HfnEPn1/d7fkfUoZiWmtDRTFPiaGIVC2Ghrq67FucoHx9KRKZgSP2G0AxPERK cQLOaQDKp3B2CzOF3VDfiNh/BP1zaP2rqHbLAkeFmR/74bP8hgSq/A8IpQID/AU/TwHJMrDOL XlzYjs1BGDom29y9YECqEXlpJM9ehpFNr4ndxxMf3pXZexaYbtngRmja1rbkDznuokFRnbDcZ MPfzg0W8EZOq/9vdFZ776UZFvBh/JX6jYxOKIAKusrXgPOL5bLeEXUXeVKl2GHyN8w0Rmdp3L L1rTbeDFkTqmIWNwsJV9+NqOtP6uiszLajAo3EUAxQutmKUEvBsLCy7k62ENiAR/obB5d4MeJ SCwRTJqclA6nty8L/E04AwdnIOvNmQwOURverUwTwuis4WAKZeTJnD5wq6beN9unAu1QG2NQP 7HjdnGT6wnqAIe44wEVJji+bAUz38VoQV0td+s+oMVXtHOTDLr6mtUo0JelorzSnNtQz9myZW Uh7/6jyzSwTl452cq43AEkrwTqGASwbS5JXdOlXB6auQRTHVhfPuX0uwydVqeCcuHPhbkh5Oi /bVTB2NMu11o09hgNA0QEfHDZwl/Gq3iWs6wJyZmN3a3QhEn+ocxCzezcq/Y8tk7mpokXaEIa Vcss5/6TpXWegLuBbZD9DLz3Qij44w5PE+ZLwJ7mLZf9NQbcZmJE1D1lv8W3wD37i3sCrvrYW CVUiR+Ir9s2OxfcisL+kvsSRCuhebrPB+bVY86zUj2ZMZRj0odxb121unhj5sy/YhpMPM/KbR G771i8Dau+Nw4Pi4kaAkMARSFOpyxsSvY4PJzuWj4XSM083Razsz8XwnLPPAwvejy8cpMYssk KBKwkYnvuDZos1XhZcRdroZAUscSPQ5Srx3MDnO9Joh8jc4VjXkxloE4w== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2021/7/14 =E4=B8=8B=E5=8D=881:44, Chris Murphy wrote: > On Tue, Jul 13, 2021 at 10:59 PM Qu Wenruo wrot= e: >> >> >> >> On 2021/7/13 =E4=B8=8B=E5=8D=8811:38, DanglingPointer wrote: > >>> 2. If we use space_cache=3Dv2, is it indeed still the case that the >>> "btrfs" command will NOT work with the filesystem? >> >> Why would you think "btrfs" won't work on a btrfs? >> > > Maybe this? > > man 5 btrfs, space_cache includes: > > The btrfs(8) command currently only has read-only support for v2. A > read-write command may be run on a v2 filesystem by clearing the > cache, running the command, and then remounting with space_cache=3Dv2. > Oh, that's only for offline tools writing into the fs, namingly "btrfs check --repair" and "mkfs.btrfs -R" And I believe that sentence is now out-of-date after btrfs-progs v4.19, which pulls all the support for write time free space tree (v2 space cache= ). I'll soon send out a patch to fix that. Thanks, Qu