/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


/*
 * --------------------------------------------------------------------
 * The purpose of this test is to see if the bug reported (#4723351) for
 * UFS exists when using a ZFS file system.
 * --------------------------------------------------------------------
 *
 */
#define _REENTRANT 1
#include <stdio.h>
#include <fcntl.h>
#include <pthread.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <unistd.h>

static const int TRUE = 1;
static char *filebase;

static int
pickidx()
{
        return (random() % 1000);
}

/* ARGSUSED */
static void *
mover(void *a)
{
        char buf[256];
        int idx, ret;

        while (TRUE) {
                idx = pickidx();
                (void) sprintf(buf, "%s.%03d", filebase, idx);
                ret = rename(filebase, buf);
                if (ret < 0 && errno != ENOENT)
                        (void) perror("renaming file");
        }

        return (NULL);
}

/* ARGSUSED */
static void *
cleaner(void *a)
{
        char buf[256];
        int idx, ret;

        while (TRUE) {
                idx = pickidx();
                (void) sprintf(buf, "%s.%03d", filebase, idx);
                ret = remove(buf);
                if (ret < 0 && errno != ENOENT)
                        (void) perror("removing file");
        }

        return (NULL);
}

static void *
writer(void *a)
{
        int *fd = (int *)a;

        while (TRUE) {
                (void) close (*fd);
                *fd = open(filebase, O_APPEND | O_RDWR | O_CREAT, 0644);
                if (*fd < 0)
                        perror("refreshing file");
                (void) write(*fd, "test\n", 5);
        }

        return (NULL);
}

int
main(int argc, char **argv)
{
        int fd;
        pthread_t tid;

        if (argc == 1) {
                (void) printf("Usage: %s <filebase>\n", argv[0]);
                exit(-1);
        }

        filebase = argv[1];
        fd = open(filebase, O_APPEND | O_RDWR | O_CREAT, 0644);
        if (fd < 0) {
                perror("creating test file");
                exit(-1);
        }

        if (pthread_setconcurrency(4)) {        /* 3 threads + main */
                fprintf(stderr, "failed to set concurrency\n");
                exit(-1);
        }
        (void) pthread_create(&tid, NULL, mover, NULL);
        (void) pthread_create(&tid, NULL, cleaner, NULL);
        (void) pthread_create(&tid, NULL, writer, (void *) &fd);

        while (TRUE) {
                int ret;
                struct stat st;

                ret = stat(filebase, &st);
                if (ret == 0 && (st.st_nlink > 2 || st.st_nlink < 1)) {
                        (void) printf("st.st_nlink = %d, exiting\n", \
                            (int)st.st_nlink);
                        exit(0);
                }
                (void) sleep(1);
        }

        return (0);
}