diff options
Diffstat (limited to 'qemu-mkcow.c')
-rw-r--r-- | qemu-mkcow.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/qemu-mkcow.c b/qemu-mkcow.c new file mode 100644 index 0000000000..2cc6332e7f --- /dev/null +++ b/qemu-mkcow.c @@ -0,0 +1,143 @@ +/* + * 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 <sys/mman.h> +#include <fcntl.h> +#include <signal.h> +#include <time.h> +#include <sys/time.h> +#include <malloc.h> +#include <termios.h> +#include <sys/poll.h> +#include <errno.h> +#include <sys/wait.h> +#include <sys/stat.h> +#include <netinet/in.h> + +#include "vl.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("vlmkcow version " QEMU_VERSION ", Copyright (c) 2003 Fabrice Bellard\n" + "usage: vlmkcow [-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; + int64_t image_size; + + image_filename = NULL; + image_size = 0; + for(;;) { + c = getopt(argc, argv, "hf:"); + if (c == -1) + break; + switch(c) { + case 'h': + help(); + break; + case 'f': + image_filename = optarg; + 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, 0644); + if (!cow_fd < 0) + return -1; + 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; +} |