new

innobase_start_or_create_for_mysql
    fsp_header_init
        btr_create
            call:fseg_create(space, 0, PAGE_HEADER + PAGE_BTR_SEG_TOP, mtr);
                params:
                    ulint    space
                    ulint    page
                    ulint    byte_offset
                    mtr_t*    mtr
                call:
                    fseg_create_general(space, page, byte_offset, FALSE, mtr)
                        A) space_header = fsp_get_space_header(space, zip_size, mtr);
                            A1) block = buf_page_get(id, zip_size, 0, RW_X_LATCH, mtr);
                                  //在free_list或者unzip lru或者lru中找一个空闲块
                        B) inode = fsp_alloc_seg_inode(space_header, mtr);