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-rw-r--r--vlmkcow.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/vlmkcow.c b/vlmkcow.c
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+++ b/vlmkcow.c
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+/*
+ * 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 <netinet/in.h>
+
+#include "vl.h"
+
+#define NO_THUNK_TYPE_SIZE
+#include "thunk.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("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;
+}