setup_fs.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include <sys/reboot.h>
   6 #include <sys/wait.h>
   7 #include <cutils/android_reboot.h>
   8 #include <cutils/partition_utils.h>
   9
  10 const char *mkfs = "/system/bin/make_ext4fs";
  11
  12 int setup_fs(const char *blockdev)
  13 {
  14     char buf[256], path[128];
  15     pid_t child;
  16     int status, n;
  17     pid_t pid;
  18
  19         /* we might be looking at an indirect reference */
  20     n = readlink(blockdev, path, sizeof(path) - 1);
  21     if (n > 0) {
  22         path[n] = 0;
  23         if (!memcmp(path, "/dev/block/", 11))
  24             blockdev = path + 11;
  25     }
  26
  27     if (strchr(blockdev,'/')) {
  28         fprintf(stderr,"not a block device name: %s\n", blockdev);
  29         return 0;
  30     }
  31
  32     snprintf(buf, sizeof(buf), "/sys/fs/ext4/%s", blockdev);
  33     if (access(buf, F_OK) == 0) {
  34         fprintf(stderr,"device %s already has a filesystem\n", blockdev);
  35         return 0;
  36     }
  37     snprintf(buf, sizeof(buf), "/dev/block/%s", blockdev);
  38
  39     if (!partition_wiped(buf)) {
  40         fprintf(stderr,"device %s not wiped, probably encrypted, not wiping\n", blockdev);
  41         return 0;
  42     }
  43
  44     fprintf(stderr,"+++\n");
  45
  46     child = fork();
  47     if (child < 0) {
  48         fprintf(stderr,"error: setup_fs: fork failed\n");
  49         return 0;
  50     }
  51     if (child == 0) {
  52         execl(mkfs, mkfs, buf, NULL);
  53         exit(-1);
  54     }
  55
  56     while ((pid=waitpid(-1, &status, 0)) != child) {
  57         if (pid == -1) {
  58             fprintf(stderr, "error: setup_fs: waitpid failed!\n");
  59             return 1;
  60         }
  61     }
  62
  63     fprintf(stderr,"---\n");
  64     return 1;
  65 }
  66
  67
  68 int main(int argc, char **argv)
  69 {
  70     int need_reboot = 0;
  71
  72     while (argc > 1) {
  73         if (strlen(argv[1]) < 128)
  74             need_reboot |= setup_fs(argv[1]);
  75         argv++;
  76         argc--;
  77     }
  78
  79     if (need_reboot) {
  80         fprintf(stderr,"REBOOT!\n");
  81         android_reboot(ANDROID_RB_RESTART, 0, 0);
  82         exit(-1);
  83     }
  84     return 0;
  85 }