+out:
+ btrfs_release_path(&path);
+ return ret;
+}
+
+static int change_device_uuid(struct btrfs_fs_info *fs_info, struct extent_buffer *eb,
+ int slot)
+{
+ struct btrfs_dev_item *di;
+ int ret = 0;
+
+ di = btrfs_item_ptr(eb, slot, struct btrfs_dev_item);
+ if (!memcmp_extent_buffer(eb, fs_info->new_fsid,
+ (unsigned long)btrfs_device_fsid(di),
+ BTRFS_FSID_SIZE))
+ return ret;
+
+ write_extent_buffer(eb, fs_info->new_fsid,
+ (unsigned long)btrfs_device_fsid(di),
+ BTRFS_FSID_SIZE);
+ ret = write_tree_block(NULL, fs_info, eb);
+
+ return ret;
+}
+
+static int change_devices_uuid(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *root = fs_info->chunk_root;
+ struct btrfs_path path;
+ struct btrfs_key key = {0, 0, 0};
+ int ret = 0;
+
+ btrfs_init_path(&path);
+ /* No transaction again */
+ ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ while (1) {
+ btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
+ if (key.type != BTRFS_DEV_ITEM_KEY ||
+ key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
+ goto next;
+ ret = change_device_uuid(fs_info, path.nodes[0], path.slots[0]);
+ if (ret < 0)
+ goto out;
+next:
+ ret = btrfs_next_item(root, &path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+ }
+out:
+ btrfs_release_path(&path);
+ return ret;
+}
+
+static int change_fsid_prepare(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *tree_root = fs_info->tree_root;
+ u64 flags = btrfs_super_flags(fs_info->super_copy);
+ int ret = 0;
+
+ flags |= BTRFS_SUPER_FLAG_CHANGING_FSID;
+ btrfs_set_super_flags(fs_info->super_copy, flags);
+
+ memcpy(fs_info->super_copy->fsid, fs_info->new_fsid, BTRFS_FSID_SIZE);
+ ret = write_all_supers(fs_info);
+ if (ret < 0)
+ return ret;
+
+ /* also restore new chunk_tree_id into tree_root for restore */
+ write_extent_buffer(tree_root->node, fs_info->new_chunk_tree_uuid,
+ btrfs_header_chunk_tree_uuid(tree_root->node),
+ BTRFS_UUID_SIZE);
+ return write_tree_block(NULL, fs_info, tree_root->node);
+}
+
+static int change_fsid_done(struct btrfs_fs_info *fs_info)
+{
+ u64 flags = btrfs_super_flags(fs_info->super_copy);
+
+ flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID;
+ btrfs_set_super_flags(fs_info->super_copy, flags);
+
+ return write_all_supers(fs_info);
+}
+
+/*
+ * Return 0 for no unfinished fsid change.
+ * Return >0 for unfinished fsid change, and restore unfinished fsid/
+ * chunk_tree_id into fsid_ret/chunk_id_ret.
+ */
+static int check_unfinished_fsid_change(struct btrfs_fs_info *fs_info,
+ uuid_t fsid_ret, uuid_t chunk_id_ret)
+{
+ struct btrfs_root *tree_root = fs_info->tree_root;
+ u64 flags = btrfs_super_flags(fs_info->super_copy);
+
+ if (flags & BTRFS_SUPER_FLAG_CHANGING_FSID) {
+ memcpy(fsid_ret, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
+ read_extent_buffer(tree_root->node, chunk_id_ret,
+ btrfs_header_chunk_tree_uuid(tree_root->node),
+ BTRFS_UUID_SIZE);
+ return 1;
+ }