/*
 * LTP diotest02.c alt
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <errno.h>

#define	BUFSIZE	4096
#define LEN	30

char filename[LEN];
int bufsize = BUFSIZE;

void fillbuf(char *buf, int count, char value)
{
	while (count > 0) {
		strncpy(buf, &value, 1);
		buf++;
		count = count - 1;
	}
}

/*
 * bufcmp: Compare two buffers
 * vbufcmp: Compare two buffers of two io arrays
*/
int bufcmp(char *b1, char *b2, int bsize)
{
	int i;

	for (i = 0; i < bsize; i++) {
		if (strncmp(&b1[i], &b2[i], 1)) {
			fprintf(stderr,
				"bufcmp: offset %d: Expected: 0x%x, got 0x%x\n",
				i, b1[i], b2[i]);
			return (-1);
		}
	}
	return (0);
}

/*
 * runtest: write the data to the file. Read the data from the file and compare.
*/
int runtest(int fd_r, int fd_w)
{
	char *buf1;
	char *buf2;
	int i = 0, ret;

	/* Allocate for buffers */
	if ((buf1 = valloc(bufsize)) == 0) {
		printf("valloc() buf1 failed: %s\n", strerror(errno));
		return (-1);
	}
	if ((buf2 = valloc(bufsize)) == 0) {
		printf("valloc() buf2 failed: %s\n", strerror(errno));
		return (-1);
	}

	fillbuf(buf1, bufsize, i);
#if 0
	if (lseek(fd_w, i * bufsize, SEEK_SET) < 0) {
		printf("lseek before write failed: %s\n", strerror(errno));
		return (-1);
	}
#endif
	ret = write(fd_w, buf1, bufsize);
	if (ret < bufsize) {
		printf("%d write failed: %s\n", ret, strerror(errno));
		return (-1);
	}
#if 0
	if (lseek(fd_r, i * bufsize, SEEK_SET) < 0) {
		printf("lseek before read failed: %s", strerror(errno));
		return (-1);
	}
#endif
	ret = read(fd_r, buf2, bufsize);
	if (ret < bufsize) {
		printf("i %d ret %d read failed: %s\n", i, ret, strerror(errno));
		return (-1);
	}
	if (bufcmp(buf1, buf2, bufsize) != 0) {
		printf("read/write comparision failed");
		return (-1);
	}
}

int main(int argc, char *argv[])
{
	long offset = 0;	/* Offset. Default 0 */
	int i, fd_r, fd_w;

	/* Options */
	sprintf(filename, "testdata-2.%ld", syscall(__NR_gettid));
#if 0
	/* Testblock-1: Read with Direct IO, Write without */
	if ((fd_w = open(filename, O_WRONLY | O_CREAT, 0666)) < 0)
		printf("open(%s, O_WRONLY..) failed\n", filename);
	if ((fd_r = open(filename, O_DIRECT | O_RDONLY, 0666)) < 0)
		printf("open(%s, O_DIRECT|O_RDONLY..) failed\n", filename);
	if (runtest(fd_r, fd_w) < 0) {
		printf("Read with Direct IO, Write without. FAIL\n");
	} else
		printf("Read with Direct IO, Write without. PASS\n");
	close(fd_w);
	close(fd_r);
	unlink(filename);
#endif
	/* Testblock-2: Write with Direct IO, Read without */
	if ((fd_w = open(filename, O_DIRECT | O_WRONLY | O_CREAT, 0666)) == -1)
		printf(
			 "open(%s, O_DIRECT|O_WRONLY..) failed\n", filename);
	if ((fd_r = open(filename, O_RDONLY | O_CREAT, 0666)) == -1)
		printf(
			 "open(%s, O_RDONLY..) failed\n", filename);
	if (runtest(fd_r, fd_w) < 0) {
		printf("Write with Direct IO, Read without. FAIL\n");
	} else
		printf("Write with Direct IO, Read without. PASS\n");
	close(fd_w);
	close(fd_r);
	unlink(filename);
#if 0
	/* Testblock-3: Read, Write with Direct IO. */
	if ((fd_w = open(filename, O_DIRECT | O_WRONLY | O_CREAT, 0666)) == -1)
		printf(
			 "open(%s, O_DIRECT|O_WRONLY|O_CREAT, ..) failed\n",
			 filename);
	if ((fd_r = open(filename, O_DIRECT | O_RDONLY | O_CREAT, 0666)) == -1)
		printf(
			 "open(%s, O_DIRECT|O_RDONLY|O_CREAT, ..) failed\n",
			 filename);
	if (runtest(fd_r, fd_w) < 0) {
		printf("Read, Write with Direct IO. FAIL\n");
	} else
		printf("Read, Write with Direct IO. PASS\n");
	close(fd_w);
	close(fd_r);
	unlink(filename);
#endif
}