blocks_freed = free_blocks(dn, bp, end-start+1, tx);
arc_buf_freeze(db->db_buf);
ASSERT(all || blocks_freed == 0 || db->db_last_dirty);
blocks_freed = free_blocks(dn, bp, end-start+1, tx);
arc_buf_freeze(db->db_buf);
ASSERT(all || blocks_freed == 0 || db->db_last_dirty);