From 0c8b978881f8f5d2b15b7bf2ec5621500ec3858a Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 11 May 2015 16:08:47 +0800 Subject: [PATCH] btrfs-progs: Introduce change_header_uuid function This function is used to change fsid and chunk_tree_uuid of a node/leaf. The function does it without transaction protection. This is the basis of offline uuid change. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- btrfstune.c | 32 ++++++++++++++++++++++++++++++++ ctree.h | 2 ++ props.c | 1 - 3 files changed, 34 insertions(+), 1 deletion(-) diff --git a/btrfstune.c b/btrfstune.c index 808466f..92837e6 100644 --- a/btrfstune.c +++ b/btrfstune.c @@ -98,6 +98,38 @@ static int enable_skinny_metadata(struct btrfs_root *root) return 0; } +static int change_header_uuid(struct btrfs_root *root, struct extent_buffer *eb) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + int same_fsid = 1; + int same_chunk_tree_uuid = 1; + int ret; + + /* Check for whether we need to change fs/chunk id */ + if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid) + return 0; + if (fs_info->new_fsid) + same_fsid = !memcmp_extent_buffer(eb, fs_info->new_fsid, + btrfs_header_fsid(), BTRFS_FSID_SIZE); + if (fs_info->new_chunk_tree_uuid) + same_chunk_tree_uuid = + !memcmp_extent_buffer(eb, fs_info->new_chunk_tree_uuid, + btrfs_header_chunk_tree_uuid(eb), + BTRFS_UUID_SIZE); + if (same_fsid && same_chunk_tree_uuid) + return 0; + if (!same_fsid) + write_extent_buffer(eb, fs_info->new_fsid, btrfs_header_fsid(), + BTRFS_FSID_SIZE); + if (!same_chunk_tree_uuid) + write_extent_buffer(eb, fs_info->new_chunk_tree_uuid, + btrfs_header_chunk_tree_uuid(eb), + BTRFS_UUID_SIZE); + ret = write_tree_block(NULL, root, eb); + + return ret; +} + static void print_usage(void) { fprintf(stderr, "usage: btrfstune [options] device\n"); diff --git a/ctree.h b/ctree.h index 98cb1fb..79a3310 100644 --- a/ctree.h +++ b/ctree.h @@ -955,7 +955,9 @@ struct btrfs_device; struct btrfs_fs_devices; struct btrfs_fs_info { u8 fsid[BTRFS_FSID_SIZE]; + u8 *new_fsid; u8 chunk_tree_uuid[BTRFS_UUID_SIZE]; + u8 *new_chunk_tree_uuid; struct btrfs_root *fs_root; struct btrfs_root *extent_root; struct btrfs_root *tree_root; diff --git a/props.c b/props.c index c7c6752..c9e2bd4 100644 --- a/props.c +++ b/props.c @@ -187,7 +187,6 @@ out: return ret; } - const struct prop_handler prop_handlers[] = { {"ro", "Set/get read-only flag of subvolume.", 0, prop_object_subvol, prop_read_only}, -- 2.7.4