Archipelago » qemu

/*

 * create a COW disk image

 * 

 * Copyright (c) 2003 Fabrice Bellard

 * 

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include <stdlib.h>

#include <stdio.h>

#include <stdarg.h>

#include <string.h>

#include <getopt.h>

#include <inttypes.h>

#include <unistd.h>

#include <fcntl.h>

#include <signal.h>

#include <time.h>

#include <sys/time.h>

#include <errno.h>

#include <sys/stat.h>

#include <netinet/in.h>

#include "cow.h"

#include "bswap.h"

int cow_create(int cow_fd, const char *image_filename, 

               int64_t image_sectors)

{

    struct cow_header_v2 cow_header;

    int fd;

    struct stat st;

    memset(&cow_header, 0, sizeof(cow_header));

    cow_header.magic = htonl(COW_MAGIC);

    cow_header.version = htonl(COW_VERSION);

    if (image_filename) {

        fd = open(image_filename, O_RDONLY);

        if (fd < 0) {

            perror(image_filename);

            exit(1);

        }

        image_sectors = lseek64(fd, 0, SEEK_END);

        if (fstat(fd, &st) != 0) {

            close(fd);

            return -1;

        }

        close(fd);

        image_sectors /= 512;

        cow_header.mtime = htonl(st.st_mtime);

        realpath(image_filename, cow_header.backing_file);

    }

    cow_header.sectorsize = htonl(512);

    cow_header.size = image_sectors * 512;

#ifndef WORDS_BIGENDIAN

    cow_header.size = bswap64(cow_header.size);

#endif    

    write(cow_fd, &cow_header, sizeof(cow_header));

    /* resize to include at least all the bitmap */

    ftruncate(cow_fd, sizeof(cow_header) + ((image_sectors + 7) >> 3));

    lseek(cow_fd, 0, SEEK_SET);

    return 0;

}

void help(void)

{

    printf("qemu-mkcow version " QEMU_VERSION ", Copyright (c) 2003 Fabrice Bellard\n"

           "usage: qemu-mkcow [-h] [-f disk_image] cow_image [cow_size]\n"

           "Create a Copy On Write disk image from an optional raw disk image\n"

           "\n"

           "-f disk_image   set the raw disk image name\n"

           "cow_image       the created cow_image\n"

           "cow_size        the create cow_image size in MB if no raw disk image is used\n"

           "\n"

           "Once the cow_image is created from a raw disk image, you must not modify the original raw disk image\n"

           );

    exit(1);

}

int main(int argc, char **argv)

{

    const char *image_filename, *cow_filename;

    int cow_fd, c, nb_args, simple_image;

    int64_t image_size;

    image_filename = NULL;

    image_size = 0;

    simple_image = 0;

    for(;;) {

        c = getopt(argc, argv, "hf:s");

        if (c == -1)

            break;

        switch(c) {

        case 'h':

            help();

            break;

        case 'f':

            image_filename = optarg;

            break;

        case 's':

            simple_image = 1;

            break;

        }

    }

    if (!image_filename)

        nb_args = 2;

    else

        nb_args = 1;

    if (optind + nb_args != argc)

        help();

    cow_filename = argv[optind];

    if (nb_args == 2) {

        image_size = (int64_t)atoi(argv[optind + 1]) * 2 * 1024;

    }

    cow_fd = open(cow_filename, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);

    if (!cow_fd < 0)

        return -1;

    if (simple_image) {

        ftruncate64(cow_fd, image_size * 512);

    } else {

        if (cow_create(cow_fd, image_filename, image_size) < 0) {

            fprintf(stderr, "%s: error while formating\n", cow_filename);

            exit(1);

        }

    }

    close(cow_fd);

    return 0;

}