__next_free_blkoff
return __next_free_blkoff(sbi, seg->segno, seg->next_blkoff + 1);
return __next_free_blkoff(sbi, segno, 0) < BLKS_PER_SEG(sbi);
curseg->next_blkoff = __next_free_blkoff(sbi, curseg->segno, 0);