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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 2C6F0C3A5A3 for ; Tue, 27 Aug 2019 06:34:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 033B62186A for ; Tue, 27 Aug 2019 06:34:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727815AbfH0Gem (ORCPT ); Tue, 27 Aug 2019 02:34:42 -0400 Received: from relay11.mail.gandi.net ([217.70.178.231]:40641 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726134AbfH0Gel (ORCPT ); Tue, 27 Aug 2019 02:34:41 -0400 Received: from [192.168.1.167] (unknown [88.191.131.7]) (Authenticated sender: swami@petaramesh.org) by relay11.mail.gandi.net (Postfix) with ESMTPSA id E1F3C100004; Tue, 27 Aug 2019 06:34:38 +0000 (UTC) Subject: Re: Massive filesystem corruption since kernel 5.2 (ARCH) To: Qu Wenruo , linux-btrfs@vger.kernel.org Cc: Christoph Anton Mitterer 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> From: =?UTF-8?Q?Sw=c3=a2mi_Petaramesh?= Openpgp: preference=signencrypt Autocrypt: addr=swami@petaramesh.org; prefer-encrypt=mutual; keydata= xsDiBEP8C/QRBADPiYmcQstlx+HdyR2FGH+bDgRZ0ZJBAx6F0OPW+CmIa6tlwdhSFtCTJGcw eqCgSKqzLS+WBd6qknpGP3D2GOmASt+Juqnl+qmX8F/XrkxSNOVGGD0vkKGX4H5uDwufWkuV 7kD/0VFJg2areJXx5tIK4+IR0E0O4Yv6DmBPwPgNUwCg0OdUy9lbCxMmshwJDGUX2Y/hiDsD /3YTjHYH2OMTg/5xXlkQgR4aWn8SaVTG1vJPcm2j2BMq1LUNklgsKw7qJToRjFndHCYjSeqF /Yk2Cbeez9qIk3lX2M59CTwbHPZAk7fCEVg1Wf7RvR2i4zEDBWKd3nChALaXLE3mTWOE1pf8 mUNPLALisxKDUkgyrwM4rZ28kKxyA/960xC5VVMkHWYYiisQQy2OQk+ElxSfPz5AWB5ijdJy SJXOT/xvgswhurPRcJc+l8Ld1GWKyey0o+EBlbkAcaZJ8RCGX77IJGG3NKDBoBN7fGXv3xQZ mFLbDyZWjQHl33wSUcskw2IP0D/vjRk/J7rHajIk+OxgbuTkeXF1qwX2yc0oU3fDom1pIFBl dGFyYW1lc2ggPHN3YW1pQHBldGFyYW1lc2gub3JnPsJ+BBMRAgA+AhsDAh4BAheABQsJCAcC BhUKCQgLAgQWAgMBFiEEzB/joG05+rK5HJguL8JcHZB24y4FAl0Cdr0FCSJsbEkACgkQL8Jc HZB24y7PrwCeIj82AsMnwgOebV274cWEyR/yaDsAn25VN/Hw+yzkeXWAn5uIWJ+ZsoZkzsNN BEP8DFwQEAC77CwwyVuzngvfFTx2UzFwFOZ25osxSYE1Hpw249kbeK09EYbvMYzcWR34vbS0 DhxqwJYH9uSuMZf/Jp4Qa/oYN4x4ZMeOGc5+BdigcetQQnZkIpMaCdFm6HK/A4aqCjqbPpvF 3Mtd4CXcl1v94pIWq/n9JrLNclUA7rWnVKkPDqJ8WaxzDWm2YH9l1H+K+JbU/ow+Rk+y5xqp jL3XpOsVqf34RQhFUyCoysvvxH8RdHAeKfWTf5x6P8jOvxB6XwOnKkX91kC2N7PzoDxY7llY Uvy+ehrVVpaKLJ1a1R2eaVIHTFGO//2ARn6g4vVPMB93FLNR0BOGzEXCnnJKO5suw9Njv/aL bdnVdDPt9nc1yn3o8Bx/nZq1asX3zo/PnMz4Up24l6GrakJFMBZybX/KxA0CXDK6Rq4HSphI y/+v0I27FiQm7oT4ykiKnfFuh16NWM8rPV0UQgBLxSBoz327bUpsRuSrYh/oYBbE6p5KYHlB Acpix7wQ61OdUihBX73/AAx0Gd53fc0d4AYeKy4JXMl2uP2aiIvBeBaOKY5tzIq9gnL5K6rr xt4PSeONoLdVo8m8OyYeao1zvpgeNZ6FJ+VCYGBtsZEYIi80Ez5V0PpgAh7kSY1xbimDqKQx A/Jq2Q7sXBCdUeHN5cDgOZLKoJRvat/rhNaCSgUNfhUc2wADBRAAskb9Eolxs20NCfs424b3 /NRI7SVn9W2hXvI61UYfs19lfScnn9YfmiN7IdB2cLCE6OiAbSsK3Aw8HDnEc0AdylVNOiIK su7C4+CW6HKMyIUm1q2qv8RwW3K8eE8+S4+4/5k+38T39BlC3HcLSxS9vfgqmF6mF6VeD5Mn DDbrm7G06UFm1Eh5PKFSzYKZ4i9rD9R4ivDCxRBT9Cibw36iigdp14z87/Qq/NoFe8j9zrbs 3/3XZ22NxS0G8aNi0ejgDeYVRUUudBXK7zjV/pJDS4luB9iOiblysJmdKI3EegHlAcapTASn qsJ42O/Uv9jdSPPruZrMbeRKILqOl/YtI0orHGW/UzMYf/vbYWZ82azkPQqKDZF3Tb3h6ZHt csifD/J9IN7xh71aPf8ayIAus1AtPFtPUTjIJXqXIvAlNcDpaEpxn8xxcbVdcRBU/odASwsX IPdz8/HV5esod/QhR6/16kkKyOJNF5M/qC3PLur8Zu4iRu8EPiPr6vTAjhLrfXbQycuVc4CV c+hGlyYSW0xFaT+XF/4d+KZirsu07P5w/OCu+oRhH4StCOz58KrtuaX1dK5nLk6XkM4nKZhC 7kmpnPqS6BkdJngkozuKQZMJahIvFglag90xgLrOl5MtO55yr/0j4S4a8GxTkVs70GttcMKN TYaSBqmVw+0A3ILCZgQYEQIAJgIbDBYhBMwf46BtOfqyuRyYLi/CXB2QduMuBQJdAnbyBQki bGwWAAoJEC/CXB2QduMur1wAn1X3FcsmMdhMfiYwXw7LVw4FAIeWAJ9kLGer22WFWR2z2iU7 BtUAN08OPA== Message-ID: <209fcd36-6748-99c5-7b6d-319571bdd11f@petaramesh.org> Date: Tue, 27 Aug 2019 08:34:38 +0200 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: <370697f1-24c9-c8bd-01a7-c2885a7ece05@gmx.com> Content-Type: text/plain; charset=utf-8 Content-Language: fr-FR Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hi Qu, Le 27/08/2019 à 08:21, Qu Wenruo a écrit : > If free space cache is invalid but passes its csum check, it's > completely *possible* to break metadata CoW, thus leads to transid mismatch. > > You can go v2 space cache which uses metadata CoW to protect its space > cache, thus in theory it should be a little safer than V1 space cache. > > Or you can just disable space cache using nospace_cache mount option, as > it's just an optimization. It's also recommended to clean existing cache > by using "btrfs check --clear-space-cache v1". > > I'd prefer to do a "btrfs check --readonly" anyway (which also checks > free space cache), then go nospace_cache if you're concerned. I will leave for travel shortly, so I will be unable to perform further tests on this machine for a week, but I'll do when I'm back. Should I understand your statement as an advice to clear the space cache even though the kernel said it has rebuilt it, or to use the V2 space cache generally speaking, on any machine that I use (I had understood it was useful only on multi-TB filesystems...) Thanks. ॐ -- Swâmi Petaramesh PGP 9076E32E