sfdisk.c

Util-linux 软件包包含许多工具。其中比较重要的是加载、卸载、格式化、分区和管理硬盘驱动器

	  pp = outer_extended_partition(ep);
    }
    fu = pp ? (pp->start + pp->size) / unit : get_disksize(format);
	
    for(pp = partitions; pp < partitions+pno; pp++)
      if (!is_parent(pp, ep) && pp->size > 0
	  && pp->start / unit >= start && pp->start / unit < fu)
	fu = pp->start / unit;

    return (fu > start) ? fu - start : 0;
}

/* compute starting sector of a partition inside an extended one */
/* return 0 on failure */
/* ep is 0 or points to surrounding extended partition */
static int
compute_start_sect(struct part_desc *p, struct part_desc *ep) {
    unsigned long base;
    int inc = (DOS && B.sectors) ? B.sectors : 1;
    int delta;

    if (ep && p->start + p->size >= ep->start + 1)
      delta = p->start - ep->start - inc;
    else if (p->start == 0 && p->size > 0)
      delta = -inc;
    else
      delta = 0;

    if (delta < 0) {
	p->start -= delta;
	p->size += delta;
	if (is_extended(p->p.sys_type) && boxes == ONESECTOR)
	  p->size = inc;
	else if ((int)(p->size) <= 0) {
	    warn(_("no room for partition descriptor\n"));
	    return 0;
	}
    }
    base = (!ep ? 0
	        : (is_extended(p->p.sys_type) ?
		   outer_extended_partition(ep) : ep)->start);
    p->ep = ep;
    if (p->p.sys_type == EMPTY_PARTITION && p->size == 0) {
        p->p.start_sect = 0;
	p->p.begin_chs = zero_chs;
	p->p.end_chs = zero_chs;
    } else {
        p->p.start_sect = p->start - base;
	p->p.begin_chs = ulong_to_chs(p->start,B);
	p->p.end_chs = ulong_to_chs(p->start + p->size - 1,B);
    }
    p->p.nr_sects = p->size;
    return 1;
}    

/* build the extended partition surrounding a given logical partition */
static int
build_surrounding_extended(struct part_desc *p, struct part_desc *ep,
			   struct disk_desc *z) {
    int inc = (DOS && B.sectors) ? B.sectors : 1;
    int format = F_SECTOR;
    struct part_desc *p0 = &(z->partitions[0]), *eep = ep->ep;

    if (boxes == NESTED) {
	ep->start = first_free(ep-p0, 1, eep, format, p->start, z);
	ep->size = max_length(ep-p0, 1, eep, format, ep->start, z);
	if (ep->start > p->start || ep->start + ep->size < p->start + p->size) {
	    warn(_("cannot build surrounding extended partition\n"));
	    return 0;
	}
    } else {
	ep->start = p->start;
	if (boxes == CHAINED)
	  ep->size = p->size;
	else
	  ep->size = inc;
    }

    ep->p.nr_sects = ep->size;
    ep->p.bootable = 0;
    ep->p.sys_type = EXTENDED_PARTITION;
    if (!compute_start_sect(ep, eep) || !compute_start_sect(p, ep)) {
	ep->p.sys_type = EMPTY_PARTITION;
	ep->size = 0;
	return 0;
    }

    return 1;
}

static int
read_line(int pno, struct part_desc *ep, char *dev, int interactive,
	  struct disk_desc *z) {
    unsigned char line[1000];
    unsigned char *fields[11];
    int fno, pct = pno%4;
    struct part_desc p, *orig;
    unsigned long ff, ff1, ul, ml, ml1, def;
    int format, lpno, is_extd;

    if (eof || eob)
      return -1;

    lpno = index_to_linux(pno, z);

    if (interactive) {
	if (pct == 0 && (show_extended || pno == 0))
	  warn("\n");
	warn("%s:", partname(dev, lpno, 10));
    }

    /* read input line - skip blank lines when reading from a file */
    do {
	fno = read_stdin(fields, line, SIZE(fields), SIZE(line));
    } while(fno == RD_CMD || (fno == 0 && !interactive));
    if (fno == RD_EOF) {
	return -1;
    } else if (fno > 10 && *(fields[10]) != 0) {
	do_warn(_("too many input fields\n"));
	return 0;
    }

    if (fno == 1 && !strcmp(fields[0], ".")) {
	eob = 1;
	return -1;
    }

    /* use specified format, but round to cylinders if F_MEGABYTE specified */
    format = 0;
    if (B.cylindersize && specified_format == F_MEGABYTE)
      format = F_CYLINDER;

    orig = (one_only ? &(oldp.partitions[pno]) : 0);

    p = zero_part_desc;
    p.ep = ep;

    /* first read the type - we need to know whether it is extended */
    /* stop reading when input blank (defaults) and all is full */
    is_extd = 0;
    if (fno == 0) {		/* empty line */
	if (orig && is_extended(orig->p.sys_type))
	  is_extd = 1;
	ff = first_free(pno, is_extd, ep, format, 0, z);
	ml = max_length(pno, is_extd, ep, format, ff, z);
	if (ml == 0 && is_extd == 0) {
	    is_extd = 1;
	    ff = first_free(pno, is_extd, ep, format, 0, z);
	    ml = max_length(pno, is_extd, ep, format, ff, z);
	}
	if (ml == 0 && pno >= 4) {
	    /* no free blocks left - don't read any further */
	    warn(_("No room for more\n"));
	    return -1;
	}
    }
    if (fno < 3 || !*(fields[2]))
      ul = orig ? orig->p.sys_type :
	   (is_extd || (pno > 3 && pct == 1 && show_extended))
	     ? EXTENDED_PARTITION : LINUX_NATIVE;
    else if (!strcmp(fields[2], "L"))
      ul = LINUX_NATIVE;
    else if (!strcmp(fields[2], "S"))
      ul = LINUX_SWAP;
    else if (!strcmp(fields[2], "E"))
      ul = EXTENDED_PARTITION;
    else if (!strcmp(fields[2], "X"))
      ul = LINUX_EXTENDED;
    else if (get_ul(fields[2], &ul, LINUX_NATIVE, 16))
      return 0;
    if (ul > 255) {
	warn(_("Illegal type\n"));
	return 0;
    }
    p.p.sys_type = ul;
    is_extd = is_extended(ul);

    /* find start */
    ff = first_free(pno, is_extd, ep, format, 0, z);
    ff1 = ff * unitsize(format);
    def = orig ? orig->start : (pno > 4 && pct > 1) ? 0 : ff1;
    if (fno < 1 || !*(fields[0]))
      p.start = def;
    else {
	if (get_ul(fields[0], &ul, def / unitsize(0), 0))
	  return 0;
	p.start = ul * unitsize(0);
	p.start -= (p.start % unitsize(format));
    }

    /* find length */
    ml = max_length(pno, is_extd, ep, format, p.start / unitsize(format), z);
    ml1 = ml * unitsize(format);
    def = orig ? orig->size : (pno > 4 && pct > 1) ? 0 : ml1;
    if (fno < 2 || !*(fields[1]))
      p.size = def;
    else {
	if (get_ul(fields[1], &ul, def / unitsize(0), 0))
	  return 0;
	p.size = ul * unitsize(0) + unitsize(format) - 1;
	p.size -= (p.size % unitsize(format));
    }
    if (p.size > ml1) {
	warn(_("Warning: given size (%lu) exceeds max allowable size (%lu)\n"),
	     (p.size + unitsize(0) - 1) / unitsize(0), ml1 / unitsize(0));
	if (!force)
	  return 0;
    }
    if (p.size == 0 && pno >= 4 && (fno < 2 || !*(fields[1]))) {
	warn(_("Warning: empty partition\n"));
	if (!force)
	  return 0;
    }
    p.p.nr_sects = p.size;

    if (p.size == 0 && !orig) {
	if (fno < 1 || !*(fields[0]))
	  p.start = 0;
	if (fno < 3 || !*(fields[2]))
	  p.p.sys_type = EMPTY_PARTITION;
    }

    if (p.start < ff1 && p.size > 0) {
	warn(_("Warning: bad partition start (earliest %lu)\n"),
	     (ff1 + unitsize(0) - 1) / unitsize(0));
	if (!force)
	  return 0;
    }

    if (fno < 4 || !*(fields[3]))
      ul = (orig ? orig->p.bootable : 0);
    else if (!strcmp(fields[3], "-"))
      ul = 0;
    else if (!strcmp(fields[3], "*") || !strcmp(fields[3], "+"))
      ul = 0x80;
    else {
    	warn(_("unrecognized bootable flag - choose - or *\n"));
    	return 0;
    }
    p.p.bootable = ul;

    if (ep && ep->p.sys_type == EMPTY_PARTITION) {
      if (!build_surrounding_extended(&p, ep, z))
	return 0;
    } else
      if (!compute_start_sect(&p, ep))
	return 0;

    { longchs aa = chs_to_longchs(p.p.begin_chs), bb;

      if (fno < 5) {
	  bb = aa;
      } else if (fno < 7) {
	  warn(_("partial c,h,s specification?\n"));
	  return 0;
      } else if (get_ul(fields[4], &bb.c, aa.c, 0) ||
		get_ul(fields[5], &bb.h, aa.h, 0) ||
		get_ul(fields[6], &bb.s, aa.s, 0))
	return 0;
      p.p.begin_chs = longchs_to_chs(bb,B);
    }
    { longchs aa = chs_to_longchs(p.p.end_chs), bb;

      if (fno < 8) {
	  bb = aa;
      } else if (fno < 10) {
	  warn(_("partial c,h,s specification?\n"));
	  return 0;
      } else if (get_ul(fields[7], &bb.c, aa.c, 0) ||
		get_ul(fields[8], &bb.h, aa.h, 0) ||
		get_ul(fields[9], &bb.s, aa.s, 0))
	return 0;
      p.p.end_chs = longchs_to_chs(bb, B);
    }

    if (pno > 3 && p.size && show_extended && p.p.sys_type != EMPTY_PARTITION
	        && (is_extended(p.p.sys_type) != (pct == 1))) {
	warn(_("Extended partition not where expected\n"));
	if (!force)
	  return 0;
    }

    z->partitions[pno] = p;
    if (pno >= z->partno)
      z->partno += 4;		/* reqd for out_partition() */

    if (interactive)
      out_partition(dev, 0, &(z->partitions[pno]), z, B);

    return 1;
}

/* ep either points to the extended partition to contain this one,
   or to the empty partition that may become extended or is 0 */
static int
read_partition(char *dev, int interactive, int pno, struct part_desc *ep,
	       struct disk_desc *z) {
    struct part_desc *p = &(z->partitions[pno]);
    int i;

    if (one_only) {
	*p = oldp.partitions[pno];
	if (one_only_pno != pno)
	  goto ret;
    } else if (!show_extended && pno > 4 && pno%4)
	  goto ret;

    while (!(i = read_line(pno, ep, dev, interactive, z)))
      if (!interactive)
	fatal(_("bad input\n"));
    if (i < 0) {
	p->ep = ep;
	return 0;
    }

  ret:
    p->ep = ep;
    if (pno >= z->partno)
      z->partno += 4;
    return 1;
}

static void
read_partition_chain(char *dev, int interactive, struct part_desc *ep,
		     struct disk_desc *z) {
    int i, base;

    eob = 0;
    while (1) {
	base = z->partno;
	if (base+4 > SIZE(z->partitions)) {
	    do_warn(_("too many partitions\n"));
	    break;
	}
	for (i=0; i<4; i++)
	  if (!read_partition(dev, interactive, base+i, ep, z))
	    return;
	for (i=0; i<4; i++) {
	    ep = &(z->partitions[base+i]);
	    if (is_extended(ep->p.sys_type) && ep->size)
	      break;
	}
	if (i == 4) {
	    /* nothing found - maybe an empty partition is going
	       to be extended */
	    if (one_only || show_extended)
	      break;
	    ep = &(z->partitions[base+1]);
	    if (ep->size || ep->p.sys_type != EMPTY_PARTITION)
	      break;
	}
    }
}

static void
read_input(char *dev, int interactive, struct disk_desc *z) {
    int i;
    struct part_desc *partitions = &(z->partitions[0]), *ep;

    for (i=0; i < SIZE(z->partitions); i++)
      partitions[i] = zero_part_desc;
    z->partno = 0;

    if (interactive)
      warn(_("Input in the following format; absent fields get a default value.\n"
             "<start> <size> <type [E,S,L,X,hex]> <bootable [-,*]> <c,h,s> <c,h,s>\n"
             "Usually you only need to specify <start> and <size> (and perhaps <type>).\n"));
    eof = 0;

    for (i=0; i<4; i++)
      read_partition(dev, interactive, i, 0, z);
    for (i=0; i<4; i++) {
	ep = partitions+i;
	if (is_extended(ep->p.sys_type) && ep->size)
	  read_partition_chain(dev, interactive, ep, z);
    }
    add_sector_and_offset(z);
}

/*
 *  G. The command line
 */

static void version(void) {
    printf("%s %s %s ([e-mail], %s)\n", PROGNAME, _("version"), VERSION, DATE);
}

static void
usage(void) {
    version();
    printf(_("Usage: %s [options] device ...\n"), PROGNAME);
    puts (_("device: something like /dev/hda or /dev/sda"));
    puts (_("useful options:"));
    puts (_("    -s [or --show-size]: list size of a partition"));
    puts (_("    -c [or --id]:        print or change partition Id"));
    puts (_("    -l [or --list]:      list partitions of each device"));
    puts (_("    -d [or --dump]:      idem, but in a format suitable for later input"));
    puts (_("    -i [or --increment]: number cylinders etc. from 1 instead of from 0"));
    puts (_("    -uS, -uB, -uC, -uM:  accept/report in units of sectors/blocks/cylinders/MB"));
    puts (_("    -T [or --list-types]:list the known partition types"));
    puts (_("    -D [or --DOS]:       for DOS-compatibility: waste a little space"));
    puts (_("    -R [or --re-read]:   make kernel reread partition table"));
    puts (_("    -N# :                change only the partition with number #"));
    puts (_("    -n :                 do not actually write to disk"));
    puts (_("    -O file :            save the sectors that will be overwritten to file"));
    puts (_("    -I file :            restore these sectors again"));
    puts (_("    -v [or --version]:   print version"));
    puts (_("    -? [or --help]:      print this message"));
    puts (_("dangerous options:"));
    puts (_("    -g [or --show-geometry]: print the kernel's idea of the geometry"));
    puts (_("    -x [or --show-extended]: also list extended partitions on output\n"
          "                             or expect descriptors for them on input"));
    puts (_("    -L  [or --Linux]:      do not complain about things irrelevant for Linux"));
    puts (_("    -q  [or --quiet]:      suppress warning messages"));
    puts (_("    You can override the detected geometry using:"));
    puts (_("    -C# [or --cylinders #]:set the number of cylinders to use"));
    puts (_("    -H# [or --heads #]:    set the number of heads to use"));
    puts (_("    -S# [or --sectors #]:  set the number of sectors to use"));
    puts (_("You can disable all consistency checking with:"));
    puts (_("    -f  [or --force]:      do what I say, even if it is stupid"));
    exit(1);
}

static void
activate_usage(char *progn) {
    puts (_("Usage:"));
    printf(_("%s device		 list active partitions on device\n"), progn);
    printf(_("%s device n1 n2 ... activate partitions n1 ..., inactivate the rest\n"), progn);
    printf(_("%s -An device	 activate partition n, inactivate the other ones\n"), PROGNAME);
    exit(1);
}

static void
unhide_usage(char *progn) {
    exit(1);
}

static char short_opts[] = "cdfgilnqsu:vx?1A::C:DH:I:LN:O:RS:TU::V";

#define PRINT_ID 0400
#define CHANGE_ID 01000

static const struct option long_opts[] = {
    { "change-id",	  no_argument, NULL, 'c' + CHANGE_ID },
    { "print-id",	  no_argument, NULL, 'c' + PRINT_ID },
    { "id",		  no_argument, NULL, 'c' },
    { "dump",             no_argument, NULL, 'd' },
    { "force",            no_argument, NULL, 'f' },
    { "show-geometry",	  no_argument, NULL, 'g' },
    { "increment",        no_argument, NULL, 'i' },
    { "list",             no_argument, NULL, 'l' },
    { "quiet",            no_argument, NULL, 'q' },
    { "show-size",        no_argument, NULL, 's' },
    { "unit",       required_argument, NULL, 'u' },
    { "version",          no_argument, NULL, 'v' },
    { "show-extended",    no_argument, NULL, 'x' },
    { "help",	          no_argument, NULL, '?' },
    { "one-only",         no_argument, NULL, '1' },
    { "cylinders",  required_argument, NULL, 'C' },
    { "heads",      required_argument, NULL, 'H' },
    { "sectors",    required_argument, NULL, 'S' },
    { "activate",   optional_argument, NULL, 'A' },
    { "DOS",              no_argument, NULL, 'D' },
    { "DOS-extended",	  no_argument, NULL, 'E' },
    { "Linux",            no_argument, NULL, 'L' },
    { "re-read",          no_argument, NULL, 'R' },
    { "list-types",       no_argument, NULL, 'T' },
    { "unhide",     optional_argument, NULL, 'U' },
    { "no-reread",        no_argument, NULL, 160 },
    { "IBM",              no_argument, NULL, 161 },
    { "leave-last",       no_argument, NULL, 161 },
/* undocumented flags - not all completely implemented */
    { "in-order",         no_argument, NULL, 128 },
    { "not-in-order",     no_argument, NULL, 129 },
    { "inside-outer",     no_argument, NULL, 130 },
    { "not-inside-outer", no_argument, NULL, 131 },
    { "nested",           no_argument, NULL, 132 },
    { "chaine