From patchwork Fri Apr 29 07:18:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 8977891 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 668B0BF29F for ; Fri, 29 Apr 2016 07:20:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6BB0720220 for ; Fri, 29 Apr 2016 07:20:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 67F7E20259 for ; Fri, 29 Apr 2016 07:20:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752378AbcD2HUo (ORCPT ); Fri, 29 Apr 2016 03:20:44 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:24705 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752358AbcD2HUJ (ORCPT ); Fri, 29 Apr 2016 03:20:09 -0400 X-IronPort-AV: E=Sophos;i="5.20,367,1444665600"; d="scan'208";a="462505" Received: from unknown (HELO cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 29 Apr 2016 15:19:19 +0800 Received: from adam-work.localdomain (unknown [10.167.226.34]) by cn.fujitsu.com (Postfix) with ESMTP id D700A4043CEE; Fri, 29 Apr 2016 15:19:14 +0800 (CST) From: Qu Wenruo To: jbacik@fb.com, linux-btrfs@vger.kernel.org Cc: Lu Fengqi Subject: [PATCH RFC v2 04/16] btrfs-progs: fsck: Introduce function to check referencer of a backref Date: Fri, 29 Apr 2016 15:18:58 +0800 Message-Id: <1461914350-19875-5-git-send-email-quwenruo@cn.fujitsu.com> X-Mailer: git-send-email 2.8.0 In-Reply-To: <1461914350-19875-1-git-send-email-quwenruo@cn.fujitsu.com> References: <1461914350-19875-1-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: D700A4043CEE.AE4AF X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: quwenruo@cn.fujitsu.com X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Lu Fengqi Introduce a new function check_tree_block_backref() to check if a backref points to correct referencer. Signed-off-by: Lu Fengqi Signed-off-by: Qu Wenruo --- cmds-check.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) diff --git a/cmds-check.c b/cmds-check.c index 699e927..fae4c26 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -322,6 +322,8 @@ struct root_item_info { #define BACKREF_MISSING (1 << 0) /* Backref missing in extent tree */ #define BACKREF_MISMATCH (1 << 1) /* Backref exists but mismatch */ #define BYTES_UNALIGNED (1 << 2) /* Some bytes are not aligned */ +#define REFERENCER_MISSING (1 << 3) /* Referencer not found */ +#define REFERENCER_MISMATCH (1 << 4) /* Referenceer found but mismatch */ static void *print_status_check(void *p) { @@ -8794,6 +8796,99 @@ release_out: return ret; } +/* + * Check if a tree block backref is valid (points to valid tree block) + * if level == -1, level will be resolved + * Return >0 for any error found and output error message + */ +static int check_tree_block_backref(struct btrfs_fs_info *fs_info, u64 root_id, + u64 bytenr, int level) +{ + struct btrfs_root *root; + struct btrfs_key key; + struct btrfs_path path; + struct extent_buffer *eb; + struct extent_buffer *node; + u32 nodesize = btrfs_super_nodesize(fs_info->super_copy); + int err = 0; + int ret; + + /* Query level for level == -1 special case */ + if (level == -1) + level = query_tree_block_level(fs_info, bytenr); + if (level < 0) { + err |= REFERENCER_MISSING; + goto out; + } + + key.objectid = root_id; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + + root = btrfs_read_fs_root(fs_info, &key); + if (IS_ERR(root)) { + err |= REFERENCER_MISSING; + goto out; + } + + /* Read out the tree block to get item/node key */ + eb = read_tree_block(root, bytenr, root->nodesize, 0); + if (!extent_buffer_uptodate(eb)) { + err |= REFERENCER_MISSING; + free_extent_buffer(eb); + goto out; + } + + /* Empty tree, no need to check key */ + if (!btrfs_header_nritems(eb) && !level) { + free_extent_buffer(eb); + goto out; + } + + if (level) + btrfs_node_key_to_cpu(eb, &key, 0); + else + btrfs_item_key_to_cpu(eb, &key, 0); + + free_extent_buffer(eb); + + btrfs_init_path(&path); + /* Search with the first key, to ensure we can reach it */ + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); + if (ret) { + err |= REFERENCER_MISSING; + goto release_out; + } + + node = path.nodes[level]; + if (btrfs_header_bytenr(node) != bytenr) { + error("Extent [%llu %d] referencer bytenr mismatch, wanted: %llu, have: %llu", + bytenr, nodesize, bytenr, + btrfs_header_bytenr(node)); + err |= REFERENCER_MISMATCH; + } + if (btrfs_header_level(node) != level) { + error("Extent [%llu %d] referencer level mismatch, wanted: %d, have: %d", + bytenr, nodesize, level, + btrfs_header_level(node)); + err |= REFERENCER_MISMATCH; + } + +release_out: + btrfs_release_path(&path); +out: + if (err & REFERENCER_MISSING) { + if (level < 0) + error("Extent [%llu %d] lost referencer(owner: %llu)", + bytenr, nodesize, root_id); + else + error("Extent [%llu %d] lost referencer(owner: %llu, level: %u)", + bytenr, nodesize, root_id, level); + } + + return err; +} + static int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, int overwrite) {