btrfs_tree_mod_log_insert_root
ret = btrfs_tree_mod_log_insert_root(root->node, c, false);
ret = btrfs_tree_mod_log_insert_root(root->node, cow, true);
ret = btrfs_tree_mod_log_insert_root(root->node, child, true);
int btrfs_tree_mod_log_insert_root(struct extent_buffer *old_root,