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

    }

    return R;
}

static void
get_cylindersize(char *dev, int fd, int silent) {
    struct geometry R;

    R = get_geometry(dev, fd, silent);

    B.heads = (U.heads ? U.heads : R.heads);
    B.sectors = (U.sectors ? U.sectors : R.sectors);
    B.cylinders = (U.cylinders ? U.cylinders : R.cylinders);

    B.cylindersize = B.heads * B.sectors;
    B.total_size = R.total_size;

    if (B.cylinders == 0 && B.cylindersize != 0)
	    B.cylinders = B.total_size / B.cylindersize;

    if (R.start && !force) {
	warn(
	    _("Warning: start=%lu - this looks like a partition rather than\n"
	      "the entire disk. Using fdisk on it is probably meaningless.\n"
	      "[Use the --force option if you really want this]\n"), R.start);
	exit(1);
    }

    if (R.heads && B.heads != R.heads)
	warn(_("Warning: HDIO_GETGEO says that there are %lu heads\n"),
	     R.heads);
    if (R.sectors && B.sectors != R.sectors)
	warn(_("Warning: HDIO_GETGEO says that there are %lu sectors\n"),
	     R.sectors);
    if (R.cylinders && B.cylinders != R.cylinders
	    && B.cylinders < 65536 && R.cylinders < 65536)
	warn(_("Warning: BLKGETSIZE/HDIO_GETGEO says that there are %lu cylinders\n"),
	     R.cylinders);

    if (B.sectors > 63)
      warn(_("Warning: unlikely number of sectors (%lu) - usually at most 63\n"
	   "This will give problems with all software that uses C/H/S addressing.\n"),
	   B.sectors);
    if (!silent)
      printf(_("\nDisk %s: %lu cylinders, %lu heads, %lu sectors/track\n"),
	     dev, B.cylinders, B.heads, B.sectors);
}

typedef struct { unsigned char h,s,c; } PACKED chs; /* has some c bits in s */
chs zero_chs = { 0,0,0 };

typedef struct { unsigned long h,s,c; } longchs;
longchs zero_longchs;

static chs
longchs_to_chs (longchs aa, struct geometry G) {
    chs a;

    if (aa.h < 256 && aa.s < 64 && aa.c < 1024) {
	a.h = aa.h;
	a.s = aa.s | ((aa.c >> 2) & 0xc0);
	a.c = (aa.c & 0xff);
    } else if (G.heads && G.sectors) {
	a.h = G.heads - 1;
	a.s = G.sectors | 0xc0;
	a.c = 0xff;
    } else
        a = zero_chs;
    return a;
}

static longchs
chs_to_longchs (chs a) {
    longchs aa;

    aa.h = a.h;
    aa.s = (a.s & 0x3f);
    aa.c = (a.s & 0xc0);
    aa.c = (aa.c << 2) + a.c;
    return aa;
}

static longchs
ulong_to_longchs (unsigned long sno, struct geometry G) {
    longchs aa;

    if (G.heads && G.sectors && G.cylindersize) {
	aa.s = 1 + sno % G.sectors;
	aa.h = (sno / G.sectors) % G.heads;
	aa.c = sno / G.cylindersize;
	return aa;
    } else {
	return zero_longchs;
    }
}

static chs
ulong_to_chs (unsigned long sno, struct geometry G) {
    return longchs_to_chs(ulong_to_longchs(sno, G), G);
}

#if 0
static unsigned long
longchs_to_ulong (longchs aa, struct geometry G) {
    return (aa.c*G.cylindersize + aa.h*G.sectors + aa.s - 1);
}

static unsigned long
chs_to_ulong (chs a, struct geometry G) {
    return longchs_to_ulong(chs_to_longchs(a), G);
}
#endif

static int
is_equal_chs (chs a, chs b) {
    return (a.h == b.h && a.s == b.s && a.c == b.c);
}

static int
chs_ok (chs a, char *v, char *w) {
    longchs aa = chs_to_longchs(a);
    int ret = 1;

    if (is_equal_chs(a, zero_chs))
      return 1;
    if (B.heads && aa.h >= B.heads) {
	warn(_("%s of partition %s has impossible value for head: "
	     "%lu (should be in 0-%lu)\n"), w, v, aa.h, B.heads-1);
	ret = 0;
    }
    if (B.sectors && (aa.s == 0 || aa.s > B.sectors)) {
	warn(_("%s of partition %s has impossible value for sector: "
	     "%lu (should be in 1-%lu)\n"), w, v, aa.s, B.sectors);
	ret = 0;
    }
    if (B.cylinders && aa.c >= B.cylinders) {
	warn(_("%s of partition %s has impossible value for cylinders: "
	     "%lu (should be in 0-%lu)\n"), w, v, aa.c, B.cylinders-1);
	ret = 0;
    }
    return ret;
}

/*
 *  D. About system Ids
 */

#define EMPTY_PARTITION		0
#define EXTENDED_PARTITION	5
#define WIN98_EXTENDED		0x0f
#define DM6_AUX1PARTITION	0x51
#define DM6_AUX3PARTITION	0x53
#define DM6_PARTITION		0x54
#define EZD_PARTITION		0x55
#define LINUX_SWAP              0x82
#define LINUX_NATIVE	        0x83
#define LINUX_EXTENDED		0x85
#define BSD_PARTITION		0xa5
#define NETBSD_PARTITION	0xa9

/* List of partition types now in i386_sys_types.c */

static const char *
sysname(unsigned char type) {
    struct systypes *s;

    for (s = i386_sys_types; s->name; s++)
      if (s->type == type)
	return _(s->name);
    return _("Unknown");
}

static void
list_types(void) {
    struct systypes *s;

    printf(_("Id  Name\n\n"));
    for (s = i386_sys_types; s->name; s++)
      printf("%2x  %s\n", s->type, _(s->name));
}

static int
is_extended(unsigned char type) {
	return (type == EXTENDED_PARTITION
		|| type == LINUX_EXTENDED
		|| type == WIN98_EXTENDED);
}

static int
is_bsd(unsigned char type) {
	return (type == BSD_PARTITION || type == NETBSD_PARTITION);
}

/*
 *  E. About partitions
 */

/* MS/DOS partition */

struct partition {
    unsigned char bootable;		/* 0 or 0x80 */
    chs begin_chs;
    unsigned char sys_type;
    chs end_chs;
    unsigned int start_sect;	/* starting sector counting from 0 */
    unsigned int nr_sects;	/* nr of sectors in partition */
} PACKED;

/* Unfortunately, partitions are not aligned, and non-Intel machines
   are unhappy with non-aligned integers. So, we need a copy by hand. */
static int
copy_to_int(unsigned char *cp) {
    unsigned int m;

    m = *cp++;
    m += (*cp++ << 8);
    m += (*cp++ << 16);
    m += (*cp++ << 24);
    return m;
}

static void
copy_from_int(int m, char *cp) {
    *cp++ = (m & 0xff); m >>= 8;
    *cp++ = (m & 0xff); m >>= 8;
    *cp++ = (m & 0xff); m >>= 8;
    *cp++ = (m & 0xff);
}

static void
copy_to_part(char *cp, struct partition *p) {
    p->bootable = *cp++;
    p->begin_chs.h = *cp++;
    p->begin_chs.s = *cp++;
    p->begin_chs.c = *cp++;
    p->sys_type = *cp++;
    p->end_chs.h = *cp++;
    p->end_chs.s = *cp++;
    p->end_chs.c = *cp++;
    p->start_sect = copy_to_int(cp);
    p->nr_sects = copy_to_int(cp+4);
}

static void
copy_from_part(struct partition *p, char *cp) {
    *cp++ = p->bootable;
    *cp++ = p->begin_chs.h;
    *cp++ = p->begin_chs.s;
    *cp++ = p->begin_chs.c;
    *cp++ = p->sys_type;
    *cp++ = p->end_chs.h;
    *cp++ = p->end_chs.s;
    *cp++ = p->end_chs.c;
    copy_from_int(p->start_sect, cp);
    copy_from_int(p->nr_sects, cp+4);
}

/* Roughly speaking, Linux doesn't use any of the above fields except
   for partition type, start sector and number of sectors. (However,
   see also linux/drivers/scsi/fdomain.c.)
   The only way partition type is used (in the kernel) is the comparison
   for equality with EXTENDED_PARTITION (and these Disk Manager types). */

struct part_desc {
    unsigned long start;
    unsigned long size;
    unsigned long sector, offset; /* disk location of this info */
    struct partition p;
    struct part_desc *ep;	  /* extended partition containing this one */
    int ptype;
#define DOS_TYPE	0
#define BSD_TYPE	1
} zero_part_desc;

static struct part_desc *
outer_extended_partition(struct part_desc *p) {
    while (p->ep)
      p = p->ep;
    return p;
}

static int
is_parent(struct part_desc *pp, struct part_desc *p) {
    while (p) {
	if (pp == p)
	  return 1;
	p = p->ep;
    }
    return 0;
}

struct disk_desc {
    struct part_desc partitions[512];
    int partno;
} oldp, newp;

/* determine where on the disk this information goes */
static void
add_sector_and_offset(struct disk_desc *z) {
    int pno;
    struct part_desc *p;

    for (pno = 0; pno < z->partno; pno++) {
	p = &(z->partitions[pno]);
	p->offset = 0x1be + (pno%4)*sizeof(struct partition);
	p->sector = (p->ep ? p->ep->start : 0);
    }
}

/* tell the kernel to reread the partition tables */
static int
reread_ioctl(int fd) {
    if (ioctl(fd, BLKRRPART)) {
	perror("BLKRRPART");

	/* 2.6.8 returns EIO for a zero table */
	if (errno == EBUSY)
		return -1;
    }
    return 0;
}

static int
is_blockdev(int fd) {
    struct stat statbuf;

    return(fstat(fd, &statbuf) == 0 && S_ISBLK(statbuf.st_mode));
}

/* reread after writing */
static void
reread_disk_partition(char *dev, int fd) {
    printf(_("Re-reading the partition table ...\n"));
    fflush(stdout);
    sync();
    sleep(3);			/* superfluous since 1.3.20 */

    if (reread_ioctl(fd) && is_blockdev(fd))
      do_warn(_("The command to re-read the partition table failed\n"
	     "Reboot your system now, before using mkfs\n"));

    if (close(fd)) {
	perror(dev);
	do_warn(_("Error closing %s\n"), dev);
    }
    printf("\n");
}

/* find Linux name of this partition, assuming that it will have a name */
static int
index_to_linux(int pno, struct disk_desc *z) {
    int i, ct = 1;
    struct part_desc *p = &(z->partitions[0]);
    for (i=0; i<pno; i++,p++)
	if (i < 4 || (p->size > 0 && !is_extended(p->p.sys_type)))
	  ct++;
    return ct;
}

static int
linux_to_index(int lpno, struct disk_desc *z) {
    int i, ct = 0;
    struct part_desc *p = &(z->partitions[0]);
    for (i=0; i<z->partno && ct < lpno; i++,p++)
      if ((i < 4 || (p->size > 0 && !is_extended(p->p.sys_type)))
	 && ++ct == lpno)
	return i;
    return -1;
}

static int
asc_to_index(char *pnam, struct disk_desc *z) {
    int pnum, pno;

    if (*pnam == '#') {
	pno = atoi(pnam+1);
    } else {
	pnum = atoi(pnam);
	pno = linux_to_index(pnum, z);
    }
    if (!(pno >= 0 && pno < z->partno))
      fatal(_("%s: no such partition\n"), pnam);
    return pno;
}

/*
 * List partitions - in terms of sectors, blocks or cylinders
 */
#define F_SECTOR   1
#define F_BLOCK    2
#define F_CYLINDER 3
#define F_MEGABYTE 4

int default_format = F_MEGABYTE;
int specified_format = 0;
int show_extended = 0;
int one_only = 0;
int one_only_pno;
int increment = 0;

static void
set_format(char c) {
    switch(c) {
      default:
	do_warn(_("unrecognized format - using sectors\n"));
      case 'S': specified_format = F_SECTOR; break;
      case 'B': specified_format = F_BLOCK; break;
      case 'C': specified_format = F_CYLINDER; break;
      case 'M': specified_format = F_MEGABYTE; break;
    }
}

static unsigned long
unitsize(int format) {
    default_format = (B.cylindersize ? F_CYLINDER : F_MEGABYTE);
    if (!format && !(format = specified_format))
      format = default_format;

    switch(format) {
      default:
      case F_CYLINDER:
	if (B.cylindersize)
	  return B.cylindersize;
      case F_SECTOR:
	return 1;
      case F_BLOCK:
	return 2;
      case F_MEGABYTE:
	return 2048;
    }
}

static unsigned long
get_disksize(int format) {
    unsigned long cs = B.cylinders;
    if (cs && leave_last)
      cs--;
    return (cs * B.cylindersize) / unitsize(format);
}

static void
out_partition_header(char *dev, int format, struct geometry G) {
    if (dump) {
	printf(_("# partition table of %s\n"), dev);
	printf("unit: sectors\n\n");
	return;
    }

    default_format = (G.cylindersize ? F_CYLINDER : F_MEGABYTE);
    if (!format && !(format = specified_format))
      format = default_format;

    switch(format) {
      default:
	do_warn(_("unimplemented format - using %s\n"),
	       G.cylindersize ? _("cylinders") : _("sectors"));
      case F_CYLINDER:
	if (G.cylindersize) {
	  printf(_("Units = cylinders of %lu bytes, blocks of 1024 bytes"
		 ", counting from %d\n\n"),
		 G.cylindersize<<9, increment);
	    printf(_("   Device Boot Start     End   #cyls    #blocks   Id  System\n"));
	    break;
	}
	/* fall through */
      case F_SECTOR:
	printf(_("Units = sectors of 512 bytes, counting from %d\n\n"),
	       increment);
	printf(_("   Device Boot    Start       End   #sectors  Id  System\n"));
	break;
      case F_BLOCK:
	printf(_("Units = blocks of 1024 bytes, counting from %d\n\n"),
	       increment);
	printf(_("   Device Boot   Start       End    #blocks   Id  System\n"));
	break;
      case F_MEGABYTE:
	printf(_("Units = mebibytes of 1048576 bytes, blocks of 1024 bytes"
	       ", counting from %d\n\n"), increment);