From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:57443 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1756057AbbEEGSx (ORCPT ); Tue, 5 May 2015 02:18:53 -0400 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t456HYAD008353 for ; Tue, 5 May 2015 14:17:34 +0800 From: Qu Wenruo To: Subject: [PATCH 4/8] btrfs-progs: Introduce change_extents_uuid() function. Date: Tue, 5 May 2015 14:16:42 +0800 Message-ID: <1430806606-3226-5-git-send-email-quwenruo@cn.fujitsu.com> In-Reply-To: <1430806606-3226-1-git-send-email-quwenruo@cn.fujitsu.com> References: <1430806606-3226-1-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is the function which iterates all metadata extent and change their fsid. This function also does it without transaction. Signed-off-by: Qu Wenruo --- btrfstune.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/btrfstune.c b/btrfstune.c index f039d84..9c1b7aa 100644 --- a/btrfstune.c +++ b/btrfstune.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -129,6 +130,74 @@ static int change_header_uuid(struct btrfs_root *root, struct extent_buffer *eb) return ret; } +static int change_extents_uuid(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root = fs_info->extent_root; + struct btrfs_path *path; + struct btrfs_key key = {0, 0, 0}; + int ret = 0; + + if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid) + return 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* + * Here we don't use transaction as it will takes a lot of reserve + * space, and that will make a near-full btrfs unable to change uuid + */ + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + while (1) { + struct btrfs_extent_item *ei; + struct extent_buffer *eb; + u64 flags; + u64 bytenr; + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (key.type != BTRFS_EXTENT_ITEM_KEY && + key.type != BTRFS_METADATA_ITEM_KEY) + goto next; + ei = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_extent_item); + flags = btrfs_extent_flags(path->nodes[0], ei); + if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) + goto next; + + bytenr = key.objectid; + eb = read_tree_block(root, bytenr, root->nodesize, 0); + if (IS_ERR(eb)) { + fprintf(stderr, "Failed to read tree block: %llu\n", + bytenr); + ret = PTR_ERR(eb); + goto out; + } + ret = change_header_uuid(root, eb); + free_extent_buffer(eb); + if (ret < 0) { + fprintf(stderr, "Failed to change uuid of tree block: %llu\n", + bytenr); + goto out; + } +next: + ret = btrfs_next_item(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + goto out; + } + } + +out: + btrfs_free_path(path); + return ret; +} + static void print_usage(void) { fprintf(stderr, "usage: btrfstune [options] device\n"); -- 2.3.7