Re: [PATCHv2 1/2] blktests: test direct io offsets

[Chaitanya Kulkarni <chaitanyak@nvidia.com>]

On 11/19/25 11:54, Keith Busch wrote:
> +static void test_invalid_dma_vector_length()
> +{
> +	const int vecs = 4;
> +
> +	bool should_fail = dma_alignment > 1;
> +	struct iovec iov[vecs];
> +	int ret;
> +
> +	iov[0].iov_base = out_buf;
> +	iov[0].iov_len = max_bytes * 2 - max_bytes / 2;
> +
> +	iov[1].iov_base = out_buf + max_bytes * 4;
> +	iov[1].iov_len = logical_block_size * 2 - (dma_alignment + 1);
> +
> +	iov[2].iov_base = out_buf + max_bytes * 8;
> +	iov[2].iov_len = logical_block_size * 2 + (dma_alignment + 1);
> +
> +	iov[3].iov_base = out_buf + max_bytes * 12;
> +	iov[3].iov_len = max_bytes - max_bytes / 2;
> +
> +        ret = pwritev(test_fd, iov, vecs, 0);
> +        if (ret < 0) {
> +		if (should_fail)
> +			return;
> +		err(errno, "%s: failed to write buf", __func__);
> +	}
> +
> +	if (should_fail)
> +		err(ENOTSUP, "%s: write buf unexpectedly succeeded with invalid DMA offset addressret:%d",
> +			__func__, ret);
> +
> +	iov[0].iov_base = in_buf;
> +	iov[0].iov_len = max_bytes * 2 - max_bytes / 2;
> +
> +	iov[1].iov_base = in_buf + max_bytes * 4;
> +	iov[1].iov_len = logical_block_size * 2 - (dma_alignment + 1);
> +
> +	iov[2].iov_base = in_buf + max_bytes * 8;
> +	iov[2].iov_len = logical_block_size * 2 + (dma_alignment + 1);
> +
> +	iov[3].iov_base = in_buf + max_bytes * 12;
> +	iov[3].iov_len = max_bytes - max_bytes / 2;
> +
> +        ret = pwritev(test_fd, iov, vecs, 0);
> +        if (ret < 0)
> +		err(errno, "%s: failed to read buf", __func__);
> +


is pwritev correct above or it should be preadv () ?


> +	compare(out_buf, in_buf, iov[0].iov_len);
> +	compare(out_buf + max_bytes * 4, in_buf + max_bytes * 4, iov[1].iov_len);
> +	compare(out_buf + max_bytes * 8, in_buf + max_bytes * 8, iov[2].iov_len);
> +	compare(out_buf + max_bytes * 12, in_buf + max_bytes * 12, iov[3].iov_len);
> +}
> +


-ck