From patchwork Tue Dec 31 07:12:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 11313791 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 17CE5138C for ; Tue, 31 Dec 2019 07:16:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8DBF206EE for ; Tue, 31 Dec 2019 07:16:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725906AbfLaHM2 (ORCPT ); Tue, 31 Dec 2019 02:12:28 -0500 Received: from mx2.suse.de ([195.135.220.15]:46452 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725536AbfLaHM2 (ORCPT ); Tue, 31 Dec 2019 02:12:28 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 8F0DEB168 for ; Tue, 31 Dec 2019 07:12:26 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH 1/5] btrfs-progs: check: Initialize extent_record::generation member Date: Tue, 31 Dec 2019 15:12:16 +0800 Message-Id: <20191231071220.32935-2-wqu@suse.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191231071220.32935-1-wqu@suse.com> References: <20191231071220.32935-1-wqu@suse.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org [BUG] When using `btrfs check --init-extent-tree`, there is a pretty high chance that the result fs can't pass tree-checker: BTRFS critical (device dm-3): corrupt leaf: block=5390336 slot=149 extent bytenr=20115456 len=4096 invalid generation, have 16384 expect (0, 360] BTRFS error (device dm-3): block=5390336 read time tree block corruption detected BTRFS error (device dm-3): failed to read block groups: -5 BTRFS error (device dm-3): open_ctree failed [CAUSE] The result fs has a pretty screwed up EXTENT_ITEMs for data extents: item 148 key (20111360 EXTENT_ITEM 4096) itemoff 8777 itemsize 53 refs 1 gen 0 flags DATA extent data backref root FS_TREE objectid 841 offset 0 count 1 item 149 key (20115456 EXTENT_ITEM 4096) itemoff 8724 itemsize 53 refs 1 gen 16384 flags DATA extent data backref root FS_TREE objectid 906 offset 0 count 1 Kernel tree-checker will accept 0 generation, but that 16384 generation is definitely going to trigger the alarm. Looking into the code, it's add_extent_rec_nolookup() allocating a new extent_rec, but not copying all members from parameter @tmpl, resulting generation not properly initialized. [FIX] Just copy tmpl->generation in add_extent_rec_nolookup(). And since all call sites have set all members of @tmpl to 0 before add_extent_rec_nolookup(), we shouldn't get garbage values. For the 0 generation problem, it will be solved in another patch. Issue: 225 (Not the initial report, but extent tree rebuild result) Signed-off-by: Qu Wenruo --- check/main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/check/main.c b/check/main.c index 08dc9e66..2dbed091 100644 --- a/check/main.c +++ b/check/main.c @@ -4605,6 +4605,7 @@ static int add_extent_rec_nolookup(struct cache_tree *extent_cache, rec->refs = tmpl->refs; rec->extent_item_refs = tmpl->extent_item_refs; rec->parent_generation = tmpl->parent_generation; + rec->generation = tmpl->generation; INIT_LIST_HEAD(&rec->backrefs); INIT_LIST_HEAD(&rec->dups); INIT_LIST_HEAD(&rec->list);