/*
 *  Write-truncate-chown testcase
 */
#include <sys/types.h>
#include <limits.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include "time.h"

long long time_diff(struct timeval *tv1, struct timeval *tv2)
{
	long long diff = 0;
	long long sec = 0;
	diff = tv2->tv_usec - tv1->tv_usec;
	sec += (tv2->tv_sec - tv1->tv_sec);
	sec *= 1000000;
	diff += sec;
	return diff;
}

int main(int argc, char **argv)

{
	int num, i;
	int ret = 0;
	int fd;
	char name[] = "test-write-truncate-chown";
	uid_t uid, gid;
	char buf[1024*1024];
	struct timeval tv[2];
	if (argc  <  2) {
		printf("usage %s <path> <num_iter>\n", argv[0]);
		return 1;
	}
	chdir(argv[1]);

	if (argc == 2)
		num = INT_MAX;
	else
		num = atoi(argv[2]);
	fd = open(name, O_CREAT|O_RDWR, 0777);
	uid = geteuid();
	uid = getegid();
	if (fd < 0)
		goto out;

	gettimeofday(tv, NULL);
	for (i = 0; i < num; i+= 2) {
		// Trigger quota transfer
		ret |= fchown(fd, i % 65538, i % 65538);
		// Trigger pages invalidate
		ftruncate(fd, 0);
		// Trigger quota transfer
		ret |= fchown(fd, (i + 1) % 65538, (i+1) % 65538);
		// Trigger allocation + space reservation
		pwrite(fd, buf, sizeof(buf));
	}
	gettimeofday(tv+1, NULL);
	ret |= unlink (name);
	printf("%lld\n", time_diff(tv, tv+1));
	if (ret) {
out:
		printf("WARN error happend during test\n");
	}
	return ret;
}