Re: [LTP] [PATCH v2 2/3] io_uring: Test READV and WRITEV operations

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> +#include "io_uring_common.h"
> +
> +#define TEST_FILE "io_uring_test_file"
> +#define QUEUE_DEPTH 2
> +#define NUM_VECS 4
> +#define VEC_SIZE 1024
> +#define VAR_BUF1_SIZE 512
> +#define VAR_BUF2_SIZE 1024
> +#define VAR_BUF3_SIZE 256
> +
> +static struct iovec *write_iovs, *read_iovs;
> +static struct iovec *var_write_iovs, *var_read_iovs;
> +static struct io_uring_submit s;
> +static sigset_t sig;
> +
> +static void prepare_write_buffers(void)
> +{
> +	size_t i, j;
> +	char *buf;
> +
> +	for (i = 0; i < NUM_VECS; i++) {
> +		buf = (char *)write_iovs[i].iov_base;
> +		for (j = 0; j < write_iovs[i].iov_len; j++) {
> +			/* Each vector has a different pattern */
> +			buf[j] = 'A' + i + (j % 26);
> +		}
> +	}
> +}
> +
> +static void prepare_read_buffers(void)
> +{
> +	size_t i;
> +
> +	for (i = 0; i < NUM_VECS; i++)
> +		memset(read_iovs[i].iov_base, 0, read_iovs[i].iov_len);
> +}
> +
> +static void clear_iovec_buffers(struct iovec *iovs, int nvecs)
> +{
> +	int i;
> +
> +	for (i = 0; i < nvecs; i++)
> +		memset(iovs[i].iov_base, 0, iovs[i].iov_len);
> +}

These two functions are nearly identical, we really need only one
function to clear the buffers.

> +static void verify_iovec_data(struct iovec *write_iovs, struct iovec *read_iovs,
> +			      int nvecs, const char *test_name)
> +{
> +	int i;
> +	size_t j;
> +
> +	for (i = 0; i < nvecs; i++) {
> +		if (write_iovs[i].iov_len != read_iovs[i].iov_len) {
> +			tst_res(TFAIL, "%s: iovec %d length mismatch: write=%zu read=%zu",
> +				test_name, i, write_iovs[i].iov_len, read_iovs[i].iov_len);
> +			return;
> +		}
> +
> +		if (memcmp(write_iovs[i].iov_base, read_iovs[i].iov_base,
> +			   write_iovs[i].iov_len) != 0) {
> +			tst_res(TFAIL, "%s: data mismatch in vector %d", test_name, i);
> +			for (j = 0; j < write_iovs[i].iov_len && j < 64; j++) {
> +				char *wbuf = (char *)write_iovs[i].iov_base;
> +				char *rbuf = (char *)read_iovs[i].iov_base;
> +				if (wbuf[j] != rbuf[j]) {
> +					tst_res(TINFO, "Vector %d: first mismatch at "
> +						"offset %zu: wrote 0x%02x, read 0x%02x",
> +						i, j, wbuf[j], rbuf[j]);
> +					break;
> +				}
> +			}
> +			return;
> +		}
> +	}
> +
> +	tst_res(TPASS, "%s: data integrity verified across %d vectors",
> +		test_name, nvecs);
> +}
> +
> +
> +static void test_writev_readv(void)
> +{
> +	int fd;
> +	int total_size = NUM_VECS * VEC_SIZE;
> +
> +	tst_res(TINFO, "Testing IORING_OP_WRITEV and IORING_OP_READV");
> +
> +	fd = SAFE_OPEN(TEST_FILE, O_RDWR | O_CREAT | O_TRUNC, 0644);
> +
> +	tst_res(TINFO, "Writing %d bytes using %d vectors", total_size, NUM_VECS);
> +	io_uring_do_vec_io_op(&s, fd, IORING_OP_WRITEV, write_iovs, NUM_VECS,
> +			      0, total_size, &sig);
> +
> +	SAFE_FSYNC(fd);
> +
> +	tst_res(TINFO, "Reading %d bytes using %d vectors", total_size, NUM_VECS);
> +	io_uring_do_vec_io_op(&s, fd, IORING_OP_READV, read_iovs, NUM_VECS,
> +			      0, total_size, &sig);
> +
> +	verify_iovec_data(write_iovs, read_iovs, NUM_VECS, "Basic vectored I/O");
> +
> +	SAFE_CLOSE(fd);
> +}
> +
> +static void test_partial_vectors(void)
> +{
> +	int fd;
> +	int half_size = 2 * VEC_SIZE;
> +
> +	tst_res(TINFO, "Testing partial vector operations");
> +
> +	fd = SAFE_OPEN(TEST_FILE, O_RDWR | O_CREAT | O_TRUNC, 0644);
> +
> +	/* Write first half using first 2 vectors at offset 0 */
> +	io_uring_do_vec_io_op(&s, fd, IORING_OP_WRITEV, write_iovs, 2, 0,
> +			      half_size, &sig);
> +
> +	/* Write second half using next 2 vectors at offset half_size */
> +	io_uring_do_vec_io_op(&s, fd, IORING_OP_WRITEV, &write_iovs[2], 2,
> +			      half_size, half_size, &sig);
> +
> +	SAFE_FSYNC(fd);
> +
> +	/* Read back entire file using all 4 vectors */
> +	io_uring_do_vec_io_op(&s, fd, IORING_OP_READV, read_iovs, NUM_VECS, 0,
> +			      NUM_VECS * VEC_SIZE, &sig);
> +
> +	verify_iovec_data(write_iovs, read_iovs, NUM_VECS, "Partial vector I/O");
> +
> +	SAFE_CLOSE(fd);
> +}
> +
> +static void test_varying_sizes(void)
> +{
> +	int fd;
> +	int expected_size = VAR_BUF1_SIZE + VAR_BUF2_SIZE + VAR_BUF3_SIZE;
> +
> +	tst_res(TINFO, "Testing vectors with varying sizes including zero-length buffer");
> +
> +	io_uring_init_buffer_pattern(var_write_iovs[0].iov_base, VAR_BUF1_SIZE, 'X');
> +	io_uring_init_buffer_pattern(var_write_iovs[2].iov_base, VAR_BUF2_SIZE, 'Y');
> +	io_uring_init_buffer_pattern(var_write_iovs[3].iov_base, VAR_BUF3_SIZE, 'Z');

Can we handle this with the prepare_write_buffers() as well?

> +	clear_iovec_buffers(var_read_iovs, 4);
> +
> +	fd = SAFE_OPEN(TEST_FILE, O_RDWR | O_CREAT | O_TRUNC, 0644);
> +
> +	io_uring_do_vec_io_op(&s, fd, IORING_OP_WRITEV, var_write_iovs, 4, 0,
> +			      expected_size, &sig);
> +
> +	SAFE_FSYNC(fd);
> +
> +	io_uring_do_vec_io_op(&s, fd, IORING_OP_READV, var_read_iovs, 4, 0,
> +			      expected_size, &sig);
> +
> +	verify_iovec_data(var_write_iovs, var_read_iovs, 4, "Varying size vector I/O with zero-length buffer");
> +
> +	SAFE_CLOSE(fd);
> +}
> +
> +static void run(void)
> +{
> +	test_writev_readv();
> +	test_partial_vectors();
> +	test_varying_sizes();
> +}
> +
> +static void setup(void)
> +{
> +	io_uring_setup_supported_by_kernel();
> +	sigemptyset(&sig);
> +	memset(&s, 0, sizeof(s));
> +	io_uring_setup_queue(&s, QUEUE_DEPTH, 0);
> +	prepare_write_buffers();
> +	prepare_read_buffers();
> +}
> +
> +static void cleanup(void)
> +{
> +	io_uring_cleanup_queue(&s, QUEUE_DEPTH);
> +}
> +
> +static struct tst_test test = {
> +	.test_all = run,
> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.needs_tmpdir = 1,
> +	.bufs = (struct tst_buffers []) {
> +		{&write_iovs, .iov_sizes = (int[]){VEC_SIZE, VEC_SIZE, VEC_SIZE, VEC_SIZE, -1}},
> +		{&read_iovs, .iov_sizes = (int[]){VEC_SIZE, VEC_SIZE, VEC_SIZE, VEC_SIZE, -1}},
> +		{&var_write_iovs, .iov_sizes = (int[]){VAR_BUF1_SIZE, 0, VAR_BUF2_SIZE, VAR_BUF3_SIZE, -1}},
> +		{&var_read_iovs, .iov_sizes = (int[]){VAR_BUF1_SIZE, 0, VAR_BUF2_SIZE, VAR_BUF3_SIZE, -1}},
> +		{}
> +	},
> +	.save_restore = (const struct tst_path_val[]) {
> +		{"/proc/sys/kernel/io_uring_disabled", "0",
> +			TST_SR_SKIP_MISSING | TST_SR_TCONF_RO},
> +		{}
> +	}
> +};
> -- 
> 2.39.1
> 

-- 
Cyril Hrubis
chrubis@suse.cz

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