f2fs_test_and_set_bit
!f2fs_test_and_set_bit(offset, se->discard_map))
exist = f2fs_test_and_set_bit(offset, se->cur_valid_map);
mir_exist = f2fs_test_and_set_bit(offset,
!f2fs_test_and_set_bit(offset, se->discard_map))
if (!f2fs_test_and_set_bit(offset, se->ckpt_valid_map)) {