#include <stdio.h>
#include <stdlib.h>
#define __USE_GNU
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>

#define ALIGN(buf)	(char *) (((unsigned long) (buf) + 4095) & ~(4095))

int main(int argc, char *argv[])
{
	char *p;
	int fd, i;
	int BS, BLOCKS;

	if (argc < 4) {
		printf("%s: <dev> bs cnt\n", argv[0]);
		return 1;
	}

	BS = atoi(argv[2]);
	BLOCKS = atoi(argv[3]);
	fd = open(argv[1], O_RDONLY | O_DIRECT);
	if (fd == -1) {
		perror("open");
		return 1;
	}

	p = ALIGN(malloc(BS + 4095));
	for (i = 0; i < BLOCKS; i++) {
		int r = read(fd, p, BS);

		if (r == BS)
			continue;
		else {
			if (r == -1)
				perror("read");

			break;
		}
	}

	return 0;
}