/* SPDX-License-Identifier: MIT */

/*

 * Description: basic read/write tests with polled IO

 */

#include <errno.h>

#include <stdio.h>

#include <unistd.h>

#include <stdlib.h>

#include <string.h>

#include <fcntl.h>

#include <sys/types.h>

#include <sys/poll.h>

#include <sys/eventfd.h>

#include <sys/resource.h>

#include "liburing.h"

#define FILE_SIZE	(128 * 1024)

#define BS		4096

#define BUFFERS		(FILE_SIZE / BS)

static struct iovec *vecs;

static int no_buf_select;

static int no_iopoll;

static int create_buffers(void)

{

	int i;

	vecs = malloc(BUFFERS * sizeof(struct iovec));

	for (i = 0; i < BUFFERS; i++) {

		if (posix_memalign(&vecs[i].iov_base, BS, BS))

			return 1;

		vecs[i].iov_len = BS;

	}

	return 0;

}

static int create_file(const char *file)

{

	ssize_t ret;

	char *buf;

	int fd;

	buf = malloc(FILE_SIZE);

	memset(buf, 0xaa, FILE_SIZE);

	fd = open(file, O_WRONLY | O_CREAT, 0644);

	if (fd < 0) {

		perror("open file");

		return 1;

	}

	ret = write(fd, buf, FILE_SIZE);

	close(fd);

	return ret != FILE_SIZE;

}

static int provide_buffers(struct io_uring *ring)

{

	struct io_uring_sqe *sqe;

	struct io_uring_cqe *cqe;

	int ret, i;

	for (i = 0; i < BUFFERS; i++) {

		sqe = io_uring_get_sqe(ring);

		io_uring_prep_provide_buffers(sqe, vecs[i].iov_base,

						vecs[i].iov_len, 1, 1, i);

	}

	ret = io_uring_submit(ring);

	if (ret != BUFFERS) {

		fprintf(stderr, "submit: %d\n", ret);

		return 1;

	}

	for (i = 0; i < BUFFERS; i++) {

		ret = io_uring_wait_cqe(ring, &cqe);

		if (cqe->res < 0) {

			fprintf(stderr, "cqe->res=%d\n", cqe->res);

			return 1;

		}

		io_uring_cqe_seen(ring, cqe);

	}

	return 0;

}

static int __test_io(const char *file, struct io_uring *ring, int write, int sqthread,

		     int fixed, int buf_select)

{

	struct io_uring_sqe *sqe;

	struct io_uring_cqe *cqe;

	int open_flags;

	int i, fd, ret;

	off_t offset;

	if (buf_select && write)

		write = 0;

	if (buf_select && fixed)

		fixed = 0;

	if (buf_select && provide_buffers(ring))

		return 1;

	if (write)

		open_flags = O_WRONLY;

	else

		open_flags = O_RDONLY;

	open_flags |= O_DIRECT;

	fd = open(file, open_flags);

	if (fd < 0) {

		perror("file open");

		goto err;

	}

	if (fixed) {

		ret = io_uring_register_buffers(ring, vecs, BUFFERS);

		if (ret) {

			fprintf(stderr, "buffer reg failed: %d\n", ret);

			goto err;

		}

	}

	if (sqthread) {

		ret = io_uring_register_files(ring, &fd, 1);

		if (ret) {

			fprintf(stderr, "file reg failed: %d\n", ret);

			goto err;

		}

	}

	offset = 0;

	for (i = 0; i < BUFFERS; i++) {

		sqe = io_uring_get_sqe(ring);

		if (!sqe) {

			fprintf(stderr, "sqe get failed\n");

			goto err;

		}

		offset = BS * (rand() % BUFFERS);

		if (write) {

			int do_fixed = fixed;

			int use_fd = fd;

			if (sqthread)

				use_fd = 0;

			if (fixed && (i & 1))

				do_fixed = 0;

			if (do_fixed) {

				io_uring_prep_write_fixed(sqe, use_fd, vecs[i].iov_base,

								vecs[i].iov_len,

								offset, i);

			} else {

				io_uring_prep_writev(sqe, use_fd, &vecs[i], 1,

								offset);

			}

		} else {

			int do_fixed = fixed;

			int use_fd = fd;

			if (sqthread)

				use_fd = 0;

			if (fixed && (i & 1))

				do_fixed = 0;

			if (do_fixed) {

				io_uring_prep_read_fixed(sqe, use_fd, vecs[i].iov_base,

								vecs[i].iov_len,

								offset, i);

			} else {

				io_uring_prep_readv(sqe, use_fd, &vecs[i], 1,

								offset);

			}

		}

		if (sqthread)

			sqe->flags |= IOSQE_FIXED_FILE;

		if (buf_select) {

			sqe->flags |= IOSQE_BUFFER_SELECT;

			sqe->buf_group = buf_select;

			sqe->user_data = i;

		}

	}

	ret = io_uring_submit(ring);

	if (ret != BUFFERS) {

		fprintf(stderr, "submit got %d, wanted %d\n", ret, BUFFERS);

		goto err;

	}

	for (i = 0; i < BUFFERS; i++) {

		ret = io_uring_wait_cqe(ring, &cqe);

		if (ret) {

			fprintf(stderr, "wait_cqe=%d\n", ret);

			goto err;

		} else if (cqe->res == -EOPNOTSUPP) {

			fprintf(stdout, "File/device/fs doesn't support polled IO\n");

			no_iopoll = 1;

			break;

		} else if (cqe->res != BS) {

			fprintf(stderr, "cqe res %d, wanted %d\n", cqe->res, BS);

			goto err;

		}

		io_uring_cqe_seen(ring, cqe);

	}

	if (fixed) {

		ret = io_uring_unregister_buffers(ring);

		if (ret) {

			fprintf(stderr, "buffer unreg failed: %d\n", ret);

			goto err;

		}

	}

	if (sqthread) {

		ret = io_uring_unregister_files(ring);

		if (ret) {

			fprintf(stderr, "file unreg failed: %d\n", ret);

			goto err;

		}

	}

	close(fd);

#ifdef VERBOSE

	fprintf(stdout, "PASS\n");

#endif

	return 0;

err:

#ifdef VERBOSE

	fprintf(stderr, "FAILED\n");

#endif

	if (fd != -1)

		close(fd);

	return 1;

}

static int test_io(const char *file, int write, int sqthread, int fixed,

		   int buf_select)

{

	struct io_uring ring;

	int ret, ring_flags;

	ring_flags = IORING_SETUP_IOPOLL;

	if (sqthread)

		ring_flags |= IORING_SETUP_SQPOLL;

	ret = io_uring_queue_init(64, &ring, ring_flags);

	if (ret) {

		fprintf(stderr, "ring create failed: %d\n", ret);

		return 1;

	}

	ret = __test_io(file, &ring, write, sqthread, fixed, buf_select);

	io_uring_queue_exit(&ring);

	return ret;

}

static int probe_buf_select(void)

{

	struct io_uring_probe *p;

	struct io_uring ring;

	int ret;

	ret = io_uring_queue_init(1, &ring, 0);

	if (ret) {

		fprintf(stderr, "ring create failed: %d\n", ret);

		return 1;

	}

	p = io_uring_get_probe_ring(&ring);

	if (!p || !io_uring_opcode_supported(p, IORING_OP_PROVIDE_BUFFERS)) {

		no_buf_select = 1;

		fprintf(stdout, "Buffer select not supported, skipping\n");

		return 0;

	}

	free(p);

	return 0;

}

int main(int argc, char *argv[])

{

	int i, ret, nr;

	char *fname;

	if (geteuid()) {

		fprintf(stdout, "iopoll requires root, skipping\n");

		return 0;

	}

	if (probe_buf_select())

		return 1;

	if (argc > 1) {

		fname = argv[1];

	} else {

		fname = ".iopoll-rw";

		if (create_file(".iopoll-rw")) {

			fprintf(stderr, "file creation failed\n");

			goto err;

		}

	}

	if (create_buffers()) {

		fprintf(stderr, "file creation failed\n");

		goto err;

	}

	nr = 16;

	if (no_buf_select)

		nr = 8;

	for (i = 0; i < nr; i++) {

		int v1, v2, v3, v4;

		v1 = (i & 1) != 0;

		v2 = (i & 2) != 0;

		v3 = (i & 4) != 0;

		v4 = (i & 8) != 0;

		ret = test_io(fname, v1, v2, v3, v4);

		if (ret) {

			fprintf(stderr, "test_io failed %d/%d/%d/%d\n", v1, v2, v3, v4);

			goto err;

		}

		if (no_iopoll)

			break;

	}

	if (fname != argv[1])

		unlink(fname);

	return 0;

err:

	if (fname != argv[1])

		unlink(fname);

	return 1;

}