From patchwork Mon Sep 17 07:28:49 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Su Yue X-Patchwork-Id: 10602131 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1C20713AD for ; Mon, 17 Sep 2018 07:22:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0520329605 for ; Mon, 17 Sep 2018 07:22:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EDC8129609; Mon, 17 Sep 2018 07:22:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9CD3A29605 for ; Mon, 17 Sep 2018 07:22:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728232AbeIQMsU (ORCPT ); Mon, 17 Sep 2018 08:48:20 -0400 Received: from mail.cn.fujitsu.com ([183.91.158.132]:63019 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727099AbeIQMsT (ORCPT ); Mon, 17 Sep 2018 08:48:19 -0400 X-IronPort-AV: E=Sophos;i="5.43,368,1503331200"; d="scan'208";a="44983914" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 17 Sep 2018 15:22:06 +0800 Received: from G08CNEXCHPEKD03.g08.fujitsu.local (unknown [10.167.33.85]) by cn.fujitsu.com (Postfix) with ESMTP id 4FA834B6EC90 for ; Mon, 17 Sep 2018 15:22:01 +0800 (CST) Received: from archlinux.g08.fujitsu.local (10.167.226.31) by G08CNEXCHPEKD03.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 17 Sep 2018 15:22:03 +0800 From: Su Yue To: CC: Subject: [PATCH v3 4/7] btrfs-progs: lowmem: search key of root again after check_fs_root() after repair Date: Mon, 17 Sep 2018 15:28:49 +0800 Message-ID: <20180917072852.25831-5-suy.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180917072852.25831-1-suy.fnst@cn.fujitsu.com> References: <20180917072852.25831-1-suy.fnst@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.31] X-yoursite-MailScanner-ID: 4FA834B6EC90.AC767 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: suy.fnst@cn.fujitsu.com Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In check_fs_roots_lowmem(), we do search and follow the resulted path to call check_fs_root(), then call btrfs_next_item() to check next root. However, if repair is enabled, the root tree can be cowed, the existed path can cause strange errors. Solution: If repair, save the key before calling check_fs_root, search the saved key again before checking next root. Signed-off-by: Su Yue --- check/mode-lowmem.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c index 4db12cc7f9fe..db44456fd85b 100644 --- a/check/mode-lowmem.c +++ b/check/mode-lowmem.c @@ -4967,9 +4967,13 @@ int check_fs_roots_lowmem(struct btrfs_fs_info *fs_info) } while (1) { + struct btrfs_key saved_key; + node = path.nodes[0]; slot = path.slots[0]; btrfs_item_key_to_cpu(node, &key, slot); + if (repair) + saved_key = key; if (key.objectid > BTRFS_LAST_FREE_OBJECTID) goto out; if (key.type == BTRFS_ROOT_ITEM_KEY && @@ -5000,6 +5004,24 @@ int check_fs_roots_lowmem(struct btrfs_fs_info *fs_info) err |= ret; } next: + /* + * Since root tree can be cowed during repair, + * here search the saved key again. + */ + if (repair) { + btrfs_release_path(&path); + ret = btrfs_search_slot(NULL, fs_info->tree_root, + &saved_key, &path, 0, 0); + /* Repair never deletes trees, search must succeed. */ + if (ret > 0) + ret = -ENOENT; + if (ret) { + error( + "search root key[%llu %u %llu] failed after repair: %s", + saved_key.objectid, saved_key.type, + saved_key.offset, strerror(-ret)); + } + } ret = btrfs_next_item(tree_root, &path); if (ret > 0) goto out;