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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 6B31DC43603 for ; Thu, 12 Dec 2019 13:34:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F172214AF for ; Thu, 12 Dec 2019 13:34:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729428AbfLLNe5 (ORCPT ); Thu, 12 Dec 2019 08:34:57 -0500 Received: from mx2.suse.de ([195.135.220.15]:56546 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729392AbfLLNe5 (ORCPT ); Thu, 12 Dec 2019 08:34:57 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 4BF3FABF6; Thu, 12 Dec 2019 13:34:54 +0000 (UTC) Subject: Re: [PATCH 3/6] btrfs: split-brain case for scanned changing device with INCOMPAT_METADATA_UUID To: damenly.su@gmail.com, linux-btrfs@vger.kernel.org Cc: Su Yue References: <20191212110132.11063-1-Damenly_Su@gmx.com> <20191212110132.11063-4-Damenly_Su@gmx.com> From: Nikolay Borisov Autocrypt: addr=nborisov@suse.com; prefer-encrypt=mutual; keydata= xsFNBFiKBz4BEADNHZmqwhuN6EAzXj9SpPpH/nSSP8YgfwoOqwrP+JR4pIqRK0AWWeWCSwmZ T7g+RbfPFlmQp+EwFWOtABXlKC54zgSf+uulGwx5JAUFVUIRBmnHOYi/lUiE0yhpnb1KCA7f u/W+DkwGerXqhhe9TvQoGwgCKNfzFPZoM+gZrm+kWv03QLUCr210n4cwaCPJ0Nr9Z3c582xc bCUVbsjt7BN0CFa2BByulrx5xD9sDAYIqfLCcZetAqsTRGxM7LD0kh5WlKzOeAXj5r8DOrU2 GdZS33uKZI/kZJZVytSmZpswDsKhnGzRN1BANGP8sC+WD4eRXajOmNh2HL4P+meO1TlM3GLl EQd2shHFY0qjEo7wxKZI1RyZZ5AgJnSmehrPCyuIyVY210CbMaIKHUIsTqRgY5GaNME24w7h TyyVCy2qAM8fLJ4Vw5bycM/u5xfWm7gyTb9V1TkZ3o1MTrEsrcqFiRrBY94Rs0oQkZvunqia c+NprYSaOG1Cta14o94eMH271Kka/reEwSZkC7T+o9hZ4zi2CcLcY0DXj0qdId7vUKSJjEep c++s8ncFekh1MPhkOgNj8pk17OAESanmDwksmzh1j12lgA5lTFPrJeRNu6/isC2zyZhTwMWs k3LkcTa8ZXxh0RfWAqgx/ogKPk4ZxOXQEZetkEyTFghbRH2BIwARAQABzSJOaWtvbGF5IEJv cmlzb3YgPG5ib3Jpc292QHN1c2UuZGU+wsF4BBMBAgAiBQJYijkSAhsDBgsJCAcDAgYVCAIJ CgsEFgIDAQIeAQIXgAAKCRBxvoJG5T8oV/B6D/9a8EcRPdHg8uLEPywuJR8URwXzkofT5bZE IfGF0Z+Lt2ADe+nLOXrwKsamhweUFAvwEUxxnndovRLPOpWerTOAl47lxad08080jXnGfYFS Dc+ew7C3SFI4tFFHln8Y22Q9075saZ2yQS1ywJy+TFPADIprAZXnPbbbNbGtJLoq0LTiESnD w/SUC6sfikYwGRS94Dc9qO4nWyEvBK3Ql8NkoY0Sjky3B0vL572Gq0ytILDDGYuZVo4alUs8 LeXS5ukoZIw1QYXVstDJQnYjFxYgoQ5uGVi4t7FsFM/6ykYDzbIPNOx49Rbh9W4uKsLVhTzG BDTzdvX4ARl9La2kCQIjjWRg+XGuBM5rxT/NaTS78PXjhqWNYlGc5OhO0l8e5DIS2tXwYMDY LuHYNkkpMFksBslldvNttSNei7xr5VwjVqW4vASk2Aak5AleXZS+xIq2FADPS/XSgIaepyTV tkfnyreep1pk09cjfXY4A7qpEFwazCRZg9LLvYVc2M2eFQHDMtXsH59nOMstXx2OtNMcx5p8 0a5FHXE/HoXz3p9bD0uIUq6p04VYOHsMasHqHPbsMAq9V2OCytJQPWwe46bBjYZCOwG0+x58 fBFreP/NiJNeTQPOa6FoxLOLXMuVtpbcXIqKQDoEte9aMpoj9L24f60G4q+pL/54ql2VRscK d87BTQRYigc+ARAAyJSq9EFk28++SLfg791xOh28tLI6Yr8wwEOvM3wKeTfTZd+caVb9gBBy wxYhIopKlK1zq2YP7ZjTP1aPJGoWvcQZ8fVFdK/1nW+Z8/NTjaOx1mfrrtTGtFxVBdSCgqBB jHTnlDYV1R5plJqK+ggEP1a0mr/rpQ9dFGvgf/5jkVpRnH6BY0aYFPprRL8ZCcdv2DeeicOO YMobD5g7g/poQzHLLeT0+y1qiLIFefNABLN06Lf0GBZC5l8hCM3Rpb4ObyQ4B9PmL/KTn2FV Xq/c0scGMdXD2QeWLePC+yLMhf1fZby1vVJ59pXGq+o7XXfYA7xX0JsTUNxVPx/MgK8aLjYW hX+TRA4bCr4uYt/S3ThDRywSX6Hr1lyp4FJBwgyb8iv42it8KvoeOsHqVbuCIGRCXqGGiaeX Wa0M/oxN1vJjMSIEVzBAPi16tztL/wQtFHJtZAdCnuzFAz8ue6GzvsyBj97pzkBVacwp3/Mw qbiu7sDz7yB0d7J2tFBJYNpVt/Lce6nQhrvon0VqiWeMHxgtQ4k92Eja9u80JDaKnHDdjdwq FUikZirB28UiLPQV6PvCckgIiukmz/5ctAfKpyYRGfez+JbAGl6iCvHYt/wAZ7Oqe/3Cirs5 KhaXBcMmJR1qo8QH8eYZ+qhFE3bSPH446+5oEw8A9v5oonKV7zMAEQEAAcLBXwQYAQIACQUC WIoHPgIbDAAKCRBxvoJG5T8oV1pyD/4zdXdOL0lhkSIjJWGqz7Idvo0wjVHSSQCbOwZDWNTN JBTP0BUxHpPu/Z8gRNNP9/k6i63T4eL1xjy4umTwJaej1X15H8Hsh+zakADyWHadbjcUXCkg OJK4NsfqhMuaIYIHbToi9K5pAKnV953xTrK6oYVyd/Rmkmb+wgsbYQJ0Ur1Ficwhp6qU1CaJ mJwFjaWaVgUERoxcejL4ruds66LM9Z1Qqgoer62ZneID6ovmzpCWbi2sfbz98+kW46aA/w8r 7sulgs1KXWhBSv5aWqKU8C4twKjlV2XsztUUsyrjHFj91j31pnHRklBgXHTD/pSRsN0UvM26 lPs0g3ryVlG5wiZ9+JbI3sKMfbdfdOeLxtL25ujs443rw1s/PVghphoeadVAKMPINeRCgoJH zZV/2Z/myWPRWWl/79amy/9MfxffZqO9rfugRBORY0ywPHLDdo9Kmzoxoxp9w3uTrTLZaT9M KIuxEcV8wcVjr+Wr9zRl06waOCkgrQbTPp631hToxo+4rA1jiQF2M80HAet65ytBVR2pFGZF zGYYLqiG+mpUZ+FPjxk9kpkRYz61mTLSY7tuFljExfJWMGfgSg1OxfLV631jV1TcdUnx+h3l Sqs2vMhAVt14zT8mpIuu2VNxcontxgVr1kzYA/tQg32fVRbGr449j1gw57BV9i0vww== Message-ID: Date: Thu, 12 Dec 2019 15:34:52 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <20191212110132.11063-4-Damenly_Su@gmx.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 12.12.19 г. 13:01 ч., damenly.su@gmail.com wrote: > From: Su Yue > > This patch adds the case for scanned changing device with > INCOMPAT_METADATA_UUID. > For this situation, the origin code only handles the case > the devices already pulled into disk with INCOMPAT_METADATA_UUID set. > There is an another case that the successful changed devices synced > without INCOMPAT_METADATA_UUID. > So add the check of Heather fsid of scanned device equals > metadata_uuid of fs_devices which is with INCOMPAT_METADATA_UUID > feature. > This is hard for me to parse and correctly understand what you mean. > Signed-off-by: Su Yue > --- > fs/btrfs/volumes.c | 29 ++++++++++++++++++++++++++--- > 1 file changed, 26 insertions(+), 3 deletions(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index b08b06a89a77..61b4a107bb58 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -654,7 +654,6 @@ static struct btrfs_fs_devices *find_fsid_inprogress( > return NULL; > } > > - > static struct btrfs_fs_devices *find_fsid_changed( > struct btrfs_super_block *disk_super) find_fsid_changed handles the case where a device belongs to a filesystem which had multiple successful fsid changed but it failed on the last one. > { > @@ -663,9 +662,14 @@ static struct btrfs_fs_devices *find_fsid_changed( > /* > * Handles the case where scanned device is part of an fs that had > * multiple successful changes of FSID but curently device didn't > - * observe it. Meaning our fsid will be different than theirs. > + * observe it. > + * > + * Case 1: the devices already changed still owns the feature, their > + * fsid must differ from the disk_super->fsid. What do you mean by device to still owns the feature? Has the bit set or something else? > */ > list_for_each_entry(fs_devices, &fs_uuids, fs_list) { > + if (fs_devices->fsid_change) > + continue; Why do you do this? > if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid, > BTRFS_FSID_SIZE) != 0 && > memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid, > @@ -676,7 +680,26 @@ static struct btrfs_fs_devices *find_fsid_changed( > } > } > > - return NULL; > + /* > + * Case 2: the synced devices doesn't have the metadata_uuid feature. > + * NOTE: the fs_devices has same metadata_uuid and fsid in memory, but > + * they differs in disk, because fs_id is copied to > + * fs_devices->metadata_id while alloc_fs_devices if no metadata It's not possible for the device to have metadata_uuid feature because this function is called from device_list_add iff the device has METADATA_UUID flag: if (fsid_change_in_progress) { if (!has_metadata_uuid) { } else { find_fsid_changed <-- here we are sure our device has METADATA_UUID set. } } > + * feature. > + */ > + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { > + if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid, > + BTRFS_FSID_SIZE) == 0 && > + memcmp(fs_devices->fsid, disk_super->metadata_uuid, > + BTRFS_FSID_SIZE) == 0 && !fs_devices->fsid_change) > + return fs_devices; > + } > + > + /* > + * Okay, can't found any fs_devices already synced, back to > + * search devices unchanged or changing like the device. > + */ > + return find_fsid(disk_super->fsid, disk_super->metadata_uuid); > } > > static struct btrfs_fs_devices *find_fsid_changing_metada_uuid( >