Exemplo n.º 1
0
int main(int argc, char** argv) {
    int fd;
    if(argc != 2) usage();
    if ((fd  = open(argv[1], O_RDWR)) == -1) die("open");

    size_t pagesize = sysconf(_SC_PAGE_SIZE);
    off_t len = fdlength(fd);
    if (len < pagesize)
        die("file to small");

    size_t pages = (len/pagesize)-1;
    unsigned int swap[129] = {0};

    // Write header.  Note that older kernel versions checked signature
    // on disk (not in cache) during swapon, so sync after writing.

    swap[0] = 1;
    swap[1] = pages;
    lseek(fd, 1024, SEEK_SET);
    write(fd, swap, 129*sizeof(unsigned int));
    lseek(fd, pagesize-10, SEEK_SET);
    write(fd, "SWAPSPACE2", 10);
    fsync(fd);

    close(fd);

    printf("Swapspace size: %luk\n", pages*(unsigned long)(pagesize/1024));
    return 0;
}
int readahead_main(int argc, char **argv)
{
	int retval = EXIT_SUCCESS;

	if (argc == 1) bb_show_usage();

	while (*++argv) {
		int fd = open_or_warn(*argv, O_RDONLY);
		if (fd >= 0) {
			int r = readahead(fd, 0, fdlength(fd));
			close(fd);
			if (r >= 0) continue;
		}
		retval = EXIT_FAILURE;
	}

	return retval;
}
Exemplo n.º 3
0
int readahead_main(int argc, char **argv)
{
	FILE *f;
	int retval = EXIT_SUCCESS;

	if (argc == 1) bb_show_usage();

	while (*++argv) {
		if ((f = fopen_or_warn(*argv, "r")) != NULL) {
			int r, fd=fileno(f);

			r = readahead(fd, 0, fdlength(fd));
			fclose(f);
			if (r >= 0) continue;
		}
		retval = EXIT_FAILURE;
	}

	return retval;
}
Exemplo n.º 4
0
// mknod in /dev based on a path like "/sys/block/hda/hda1"
static void make_device(char *path)
{
  char *device_name = NULL, *s, *temp;
  int major, minor, type, len, fd;
  int mode = 0660;
  uid_t uid = 0;
  gid_t gid = 0;

  if (path) {
    // Try to read major/minor string

    temp = strrchr(path, '/');
    fd = open(path, O_RDONLY);
    *temp=0;
    temp = toybuf;
    len = read(fd, temp, 64);
    close(fd);
    if (len<1) return;
    temp[len] = 0;

    // Determine device type, major and minor

    type = path[5]=='c' ? S_IFCHR : S_IFBLK;
    major = minor = 0;
    sscanf(temp, "%u:%u", &major, &minor);
  } else {
    // if (!path), do hotplug

    if (!(temp = getenv("SUBSYSTEM")))
      return;
    type = strcmp(temp, "block") ? S_IFCHR : S_IFBLK;
    major = minor = 0;
    if (!(temp = getenv("MAJOR")))
      return;
    sscanf(temp, "%u", &major);
    if (!(temp = getenv("MINOR")))
      return;
    sscanf(temp, "%u", &minor);
    path = getenv("DEVPATH");
    device_name = getenv("DEVNAME");
    if (!path)
      return;
    temp = toybuf;
  }
  if (!device_name)
    device_name = strrchr(path, '/') + 1;

  // If we have a config file, look up permissions for this device

  if (CFG_MDEV_CONF) {
    char *conf, *pos, *end;

    // mmap the config file
    if (-1!=(fd = open("/etc/mdev.conf", O_RDONLY))) {
      len = fdlength(fd);
      conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
      if (conf) {
        int line = 0;

        // Loop through lines in mmaped file
        for (pos = conf; pos-conf<len;) {
          int field;
          char *end2;

          line++;
          // find end of this line
          for(end = pos; end-conf<len && *end!='\n'; end++);

          // Three fields: regex, uid:gid, mode
          for (field = 3; field; field--) {
            // Skip whitespace
            while (pos<end && isspace(*pos)) pos++;
            if (pos==end || *pos=='#') break;
            for (end2 = pos;
              end2<end && !isspace(*end2) && *end2!='#'; end2++);
            switch(field) {
              // Regex to match this device
              case 3:
              {
                char *regex = strndup(pos, end2-pos);
                regex_t match;
                regmatch_t off;
                int result;

                // Is this it?
                xregcomp(&match, regex, REG_EXTENDED);
                result=regexec(&match, device_name, 1, &off, 0);
                regfree(&match);
                free(regex);

                // If not this device, skip rest of line
                if (result || off.rm_so
                  || off.rm_eo!=strlen(device_name))
                    goto end_line;

                break;
              }
              // uid:gid
              case 2:
              {
                char *s2;

                // Find :
                for(s = pos; s<end2 && *s!=':'; s++);
                if (s==end2) goto end_line;

                // Parse UID
                uid = strtoul(pos,&s2,10);
                if (s!=s2) {
                  struct passwd *pass;
                  char *str = strndup(pos, s-pos);
                  pass = getpwnam(str);
                  free(str);
                  if (!pass) goto end_line;
                  uid = pass->pw_uid;
                }
                s++;
                // parse GID
                gid = strtoul(s,&s2,10);
                if (end2!=s2) {
                  struct group *grp;
                  char *str = strndup(s, end2-s);
                  grp = getgrnam(str);
                  free(str);
                  if (!grp) goto end_line;
                  gid = grp->gr_gid;
                }
                break;
              }
              // mode
              case 1:
              {
                mode = strtoul(pos, &pos, 8);
                if (pos!=end2) goto end_line;
                goto found_device;
              }
            }
            pos=end2;
          }
end_line:
          // Did everything parse happily?
          if (field && field!=3) error_exit("Bad line %d", line);

          // Next line
          pos = ++end;
        }
found_device:
        munmap(conf, len);
      }
      close(fd);
    }
  }

  sprintf(temp, "/dev/%s", device_name);

  if (getenv("ACTION") && !strcmp(getenv("ACTION"), "remove")) {
    unlink(temp);
    return;
  }

  if (strchr(device_name, '/'))
    mkpathat(AT_FDCWD, temp, 0, 2);
  if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST)
    perror_exit("mknod %s failed", temp);

 
  if (type == S_IFBLK) close(open(temp, O_RDONLY)); // scan for partitions

  if (CFG_MDEV_CONF) mode=chown(temp, uid, gid);
}