/*
 * 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.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/param.h>
#include <string.h>

#define FSIZE   256*1024*1024
#define BSIZE   512

/* Initialize Globals */
static long     fsize = FSIZE;
static size_t   bsize = BSIZE;
static int      count = 0;
static int      rflag = 0;
static int      seed = 0;
static int      vflag = 0;
static int      errflag = 0;
static off_t    offset = 0;
static char     *filename = NULL;

static void usage(char *execname);
static void parse_options(int argc, char *argv[]);
static void do_write(int fd);
static void do_trunc(int fd);

static void
usage(char *execname)
{
        (void) fprintf(stderr,
            "usage: %s [-b blocksize] [-c count] [-f filesize]"
            " [-o offset] [-s seed] [-r] [-v] filename\n", execname);
        (void) exit(1);
}

int
main(int argc, char *argv[])
{
        int i = 0;
        int fd = -1;

        parse_options(argc, argv);

        fd = open(filename, O_RDWR|O_CREAT|O_TRUNC, 0666);
        if (fd < 0) {
                perror("open");
                exit(3);
        }

        while (i < count) {
                (void) do_write(fd);
                (void) do_trunc(fd);

                i++;
        }

        (void) close(fd);
        return (0);
}

static void
parse_options(int argc, char *argv[])
{
        int c;

        extern char *optarg;
        extern int optind, optopt;

        count = fsize / bsize;
        seed = time(NULL);
        while ((c = getopt(argc, argv, "b:c:f:o:rs:v")) != -1) {
                switch (c) {
                        case 'b':
                                bsize = atoi(optarg);
                                break;

                        case 'c':
                                count = atoi(optarg);
                                break;

                        case 'f':
                                fsize = atoi(optarg);
                                break;

                        case 'o':
                                offset = atoi(optarg);
                                break;

                        case 'r':
                                rflag++;
                                break;

                        case 's':
                                seed = atoi(optarg);
                                break;

                        case 'v':
                                vflag++;
                                break;

                        case ':':
                                (void) fprintf(stderr,
                                    "Option -%c requires an operand\n", optopt);
                                errflag++;
                                break;

                        case '?':
                                (void) fprintf(stderr,
                                    "Unrecognized option: -%c\n", optopt);
                                errflag++;
                                break;
                }

                if (errflag) {
                        (void) usage(argv[0]);
                }
        }
        if (argc <= optind) {
                (void) fprintf(stderr,
                    "No filename specified\n");
                usage(argv[0]);
        }
        filename = argv[optind];

        if (vflag) {
                (void) fprintf(stderr, "Seed = %d\n", seed);
        }
        srandom(seed);
}

static void
do_write(int fd)
{
        off_t   roffset = 0;
        char    *buf = NULL;
        char    *rbuf = NULL;

        buf = (char *)calloc(1, bsize);
        rbuf = (char *)calloc(1, bsize);
        if (buf == NULL || rbuf == NULL) {
                perror("malloc");
                exit(4);
        }

        roffset = random() % fsize;
        if (lseek(fd, (offset + roffset), SEEK_SET) < 0) {
                perror("lseek");
                exit(5);
        }

        strcpy(buf, "ZFS Test Suite Truncation Test");
        if (write(fd, buf, bsize) < bsize) {
                perror("write");
                exit(6);
        }

        if (rflag) {
                if (lseek(fd, (offset + roffset), SEEK_SET) < 0) {
                        perror("lseek");
                        exit(7);
                }

                if (read(fd, rbuf, bsize) < bsize) {
                        perror("read");
                        exit(8);
                }

                if (memcmp(buf, rbuf, bsize) != 0) {
                        perror("memcmp");
                        exit(9);
                }
        }
        if (vflag) {
                (void) fprintf(stderr,
                    "Wrote to offset %ld\n", (offset + roffset));
                if (rflag) {
                        (void) fprintf(stderr,
                            "Read back from offset %ld\n", (offset + roffset));
                }
        }

        (void) free(buf);
        (void) free(rbuf);
}

static void
do_trunc(int fd)
{
        off_t   roffset = 0;

        roffset = random() % fsize;
        if (ftruncate(fd, (offset + roffset))  < 0) {
                perror("truncate");
                exit(7);
        }

        if (vflag) {
                (void) fprintf(stderr,
                    "Truncated at offset %ld\n",
                    (offset + roffset));
        }
}