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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 6B308C3A59F for ; Thu, 29 Aug 2019 13:12:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2AA32208C2 for ; Thu, 29 Aug 2019 13:12:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="ZF4BEjrp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727234AbfH2NMC (ORCPT ); Thu, 29 Aug 2019 09:12:02 -0400 Received: from mout.gmx.net ([212.227.15.18]:55455 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726985AbfH2NMC (ORCPT ); Thu, 29 Aug 2019 09:12:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1567084318; bh=3nmBVGm4s2QI0mjqma6HFnT6N6Aor5vEmNmKAE9OlJI=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=ZF4BEjrpVfaonPW0KNroCZjFMX9wINKhJT6d+NkaTX63CQMdG1C0SoQISCMjWWj+V gURH1jHapUNULk55unf6Ng4eYC+ZyItLWlm2VkwX+vvOOYwLWocv7pu500mzpra4hE rMp9nmsH/nfQPJp1KrUKxoZ6/0WptIxZ54EyeMnc= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([13.231.109.76]) by mail.gmx.com (mrgmx003 [212.227.17.184]) with ESMTPSA (Nemesis) id 0MIuSH-1i5ExR3SNV-002Urm; Thu, 29 Aug 2019 15:11:58 +0200 Subject: Re: Massive filesystem corruption since kernel 5.2 (ARCH) To: Oliver Freyermuth , Hans van Kranenburg , =?UTF-8?Q?Sw=c3=a2mi_Petaramesh?= , linux-btrfs@vger.kernel.org References: <11e4e889f903ddad682297c4420faeb0245414cf.camel@scientia.net> <18d24f2f-4d33-10aa-5052-c358d4f7c328@petaramesh.org> <5aefca34-224a-0a81-c930-4ccfcd144aef@petaramesh.org> <4bd70aa2-7ad0-d5c6-bc1f-22340afaac60@petaramesh.org> <370697f1-24c9-c8bd-01a7-c2885a7ece05@gmx.com> <209fcd36-6748-99c5-7b6d-319571bdd11f@petaramesh.org> <6525d5cf-9203-0332-cad5-2abc5d3e541c@gmx.com> <317a6f8f-3810-4a6c-ba64-3825317de1e7@petaramesh.org> <3fe4a6dd-942b-56b6-c5ca-fed5e801dc0e@googlemail.com> From: Qu Wenruo Openpgp: preference=signencrypt Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAVQEEwEIAD4CGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWCnQUJCWYC bgAKCRDCPZHzoSX+qAR8B/94VAsSNygx1C6dhb1u1Wp1Jr/lfO7QIOK/nf1PF0VpYjTQ2au8 ihf/RApTna31sVjBx3jzlmpy+lDoPdXwbI3Czx1PwDbdhAAjdRbvBmwM6cUWyqD+zjVm4RTG rFTPi3E7828YJ71Vpda2qghOYdnC45xCcjmHh8FwReLzsV2A6FtXsvd87bq6Iw2axOHVUax2 FGSbardMsHrya1dC2jF2R6n0uxaIc1bWGweYsq0LXvLcvjWH+zDgzYCUB0cfb+6Ib/ipSCYp 3i8BevMsTs62MOBmKz7til6Zdz0kkqDdSNOq8LgWGLOwUTqBh71+lqN2XBpTDu1eLZaNbxSI ilaVuQENBFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcga CbPEwhLj1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj /IrRUUka68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fN GSsRb+pKEKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0 q1eW4Jrv0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEv ABEBAAGJATwEGAEIACYWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWBrwIbDAUJA8JnAAAK CRDCPZHzoSX+qA3xB/4zS8zYh3Cbm3FllKz7+RKBw/ETBibFSKedQkbJzRlZhBc+XRwF61mi f0SXSdqKMbM1a98fEg8H5kV6GTo62BzvynVrf/FyT+zWbIVEuuZttMk2gWLIvbmWNyrQnzPl mnjK4AEvZGIt1pk+3+N/CMEfAZH5Aqnp0PaoytRZ/1vtMXNgMxlfNnb96giC3KMR6U0E+siA 4V7biIoyNoaN33t8m5FwEwd2FQDG9dAXWhG13zcm9gnk63BN3wyCQR+X5+jsfBaS4dvNzvQv h8Uq/YGjCoV1ofKYh3WKMY8avjq25nlrhzD/Nto9jHp8niwr21K//pXVA81R2qaXqGbql+zo Message-ID: Date: Thu, 29 Aug 2019 21:11:51 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <3fe4a6dd-942b-56b6-c5ca-fed5e801dc0e@googlemail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:PfAN9mftHseOEE4XFUEwNHz0wYE+D9YsdstEgRfUHBHe32uCmHA glJJ91RrBeD37HYmRFD+IVzjEYhmO7BNEntZSn//88BHKkVyEtvvfKkEbmZCD2x22yt/cle ohAzqeflZN15eZc/ty8qUOGkYxH/y9gQJi1rPEYoeibUw47TfLvGuSqRwGZVlbaaXnIBZMG Kr2rIr4jyRJ7RM8gn0gBg== X-UI-Out-Filterresults: notjunk:1;V03:K0:NAKbRHL0KxE=:XsOHFYcIk3Zrl/IRDDfXv3 E9zwAeo9vwfzC3hPf4h4dXOJyYospg/CIcS+l01L4i3gPYkCD4swbi7Z8AccToM72YJYt2hmw WOwXjivCTVkR6cuytmnNt6IDr9a+zOLz7FQCqfSayF9ifkcif0XGRhjqPUlkn5vJCsZOBQgF5 UIqCUCgbXUVNZV2HKGduju+5sNboV9JutqQunl54swunvCuSAiCGmk9VBGPEyZ81X0zfy30ko jCQFuJWwNeaq0ChfaZSaMoRNt48ertWn85JcJTORSocMJfngRV4NeoDydn9H6mx51Vt7EfrHO J0NAaftrPkUTrlQncVUgDerv7DJZy0JAynV0wmeFSGQBoWXp3KQE8CeFnwNg0vmhyGadcImxV +vjibS7Euln4qvUC8O+OZO7WeyjvMlFwBD6YDqa3yy56VO9v1TAO60Dv7BQDoYzHH8O8uEqm5 hT2Ub5i0CkRDnbp8/hSyMtsk4ZwwHiG4d22CgiHJPTbFvudnJB6jWat91x4GYxmq6lKq/2akI PEDlrFuyu5Eglr2JQaqtS3HnQgb8XRStViBOTa035WYxiVtz1bIL94vA5QPO7Wk3re6SbRMvS 5u4Jq22opVaaRVGBnHsN9ZePb5xlBLkk+nB+dk9W30FEKO1w5WpGyqYJOY1Gx+x1MmMNY1HAv TaQx8dhgLbaEB0V6UUG5ui0mgL9PsnLY0yMn66yXphATbu9pM0Z8fOFLbK0jWGFry4qE8GgCd ZBqLSSk1IiuoRPsC3kf8J5ciWeYlKUp9CB1H6OzCU3/8edTK6eRTajFEUd3PcbFCLrFizu36x tHAiZNCoE9AaqXr7c5uw+n8WdeWnJybxSYYT7c/3E7i+xV6Xdwqh+zLL6Vt1XbkPHJ4wbEcSH shQvSn6oTjGYr3pjCalWTbWTmbGsQtUEkvuafOFTqQxRDT5ZBSuTL1N0BIAOMay/weO9RmlJh dMJ4w2BDT80c56wsrxDxY5azXZFWCMfDhtRY6h0n/qYcGK4bU5pipzv8u3+jSj63xD5yWtaFn B17FYt/m/UJsMwD2JPuYbZK8BRa9iY18Ff9ens4veijwasKB3QVwjpMzV3tvr20Re9YTMBV1N BJVos0mdtObR1oksrdDtXVGNHtRUxABErBXiRPAMdrKxfrbhFKTVGJ52tmWV7e1iJG9kD79PC IEJpC3YDX9p8OCnykD6MXrr5Sv0al39aCCaZ8YlluvgBoweg== Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2019/8/29 =E4=B8=8B=E5=8D=888:46, Oliver Freyermuth wrote: > Am 27.08.19 um 14:40 schrieb Hans van Kranenburg: >> On 8/27/19 11:14 AM, Sw=C3=A2mi Petaramesh wrote: >>> On 8/27/19 8:52 AM, Qu Wenruo wrote: >>>>> or to use the V2 space >>>>> cache generally speaking, on any machine that I use (I had understoo= d it >>>>> was useful only on multi-TB filesystems...) >>>> 10GiB is enough to create large enough block groups to utilize free >>>> space cache. >>>> So you can't really escape from free space cache. >>> >>> I meant that I had understood that the V2 space cache was preferable t= o >>> V1 only for multi-TB filesystems. >>> >>> So would you advise to use V2 space cache also for filesystems < 1 TB = ? >> >> Yes. >> > > This makes me wonder if it should be the default? It will be. Just a spoiler, I believe features like no-holes and v2 space cache will be default in not so far future. > > This thread made me check on my various BTRFS volumes and for almost all= of them (in different machines), I find cases of > failed to load free space cache for block group XXXX, rebuilding it now > at several points during the last months in my syslogs - and that's for = machines without broken memory, for disks for which FUA should be working = fine, > without any unsafe shutdowns over their lifetime, and with histories as = short as only having seen 5.x kernels. That's interesting. In theory that shouldn't happen, especially without unsafe shutdown. But please also be aware that, there is no concrete proof that corrupted v1 space cache is causing all the problems. What I said is just, corrupted v1 space cache may cause problem, I need to at least craft an image to proof my assumption. > > So if this may cause harmful side effects, happens without clear origin,= and v2 is safer due to being CoW, > I guess I should switch all my nodes to v2 (or this should become the de= fault in a future kernel?). At least, your experience would definitely help the btrfs community. Thanks, Qu > > Cheers, > Oliver >