source: MondoRescue/branches/stable/mindi-busybox/util-linux/fdisk.c@ 1770

/* vi: set sw=4 ts=4: */
/* fdisk.c -- Partition table manipulator for Linux.
 *
 * Copyright (C) 1992  A. V. Le Blanc (LeBlanc@mcc.ac.uk)
 * Copyright (C) 2001,2002 Vladimir Oleynik <dzo@simtreas.ru> (initial bb port)
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#ifndef _LARGEFILE64_SOURCE
/* For lseek64 */
#define _LARGEFILE64_SOURCE
#endif
#include <assert.h>             /* assert */
#include "libbb.h"

/* Looks like someone forgot to add this to config system */
#ifndef ENABLE_FEATURE_FDISK_BLKSIZE
# define ENABLE_FEATURE_FDISK_BLKSIZE 0
# define USE_FEATURE_FDISK_BLKSIZE(a)
#endif

#define DEFAULT_SECTOR_SIZE     512
#define MAX_SECTOR_SIZE 2048
#define SECTOR_SIZE     512     /* still used in osf/sgi/sun code */
#define MAXIMUM_PARTS   60

#define ACTIVE_FLAG     0x80

#define EXTENDED        0x05
#define WIN98_EXTENDED  0x0f
#define LINUX_PARTITION 0x81
#define LINUX_SWAP      0x82
#define LINUX_NATIVE    0x83
#define LINUX_EXTENDED  0x85
#define LINUX_LVM       0x8e
#define LINUX_RAID      0xfd

/* Used for sector numbers. Today's disk sizes make it necessary */
typedef unsigned long long ullong;

struct hd_geometry {
    unsigned char heads;
    unsigned char sectors;
    unsigned short cylinders;
    unsigned long start;
};

#define HDIO_GETGEO     0x0301  /* get device geometry */

static const char msg_building_new_label[] ALIGN1 =
"Building a new %s. Changes will remain in memory only,\n"
"until you decide to write them. After that the previous content\n"
"won't be recoverable.\n\n";

static const char msg_part_already_defined[] ALIGN1 =
"Partition %d is already defined, delete it before re-adding\n";


static unsigned sector_size = DEFAULT_SECTOR_SIZE;
static unsigned user_set_sector_size;
static unsigned sector_offset = 1;

#if ENABLE_FEATURE_OSF_LABEL
static int possibly_osf_label;
#endif

static unsigned heads, sectors, cylinders;
static void update_units(void);


struct partition {
    unsigned char boot_ind;         /* 0x80 - active */
    unsigned char head;             /* starting head */
    unsigned char sector;           /* starting sector */
    unsigned char cyl;              /* starting cylinder */
    unsigned char sys_ind;          /* What partition type */
    unsigned char end_head;         /* end head */
    unsigned char end_sector;       /* end sector */
    unsigned char end_cyl;          /* end cylinder */
    unsigned char start4[4];        /* starting sector counting from 0 */
    unsigned char size4[4];         /* nr of sectors in partition */
} ATTRIBUTE_PACKED;

static const char unable_to_open[] ALIGN1 = "cannot open %s";
static const char unable_to_read[] ALIGN1 = "cannot read from %s";
static const char unable_to_seek[] ALIGN1 = "cannot seek on %s";
static const char unable_to_write[] ALIGN1 = "cannot write to %s";
static const char ioctl_error[] ALIGN1 = "BLKGETSIZE ioctl failed on %s";
static void fdisk_fatal(const char *why) ATTRIBUTE_NORETURN;

enum label_type {
    label_dos, label_sun, label_sgi, label_aix, label_osf
};

#define LABEL_IS_DOS    (label_dos == current_label_type)

#if ENABLE_FEATURE_SUN_LABEL
#define LABEL_IS_SUN    (label_sun == current_label_type)
#define STATIC_SUN static
#else
#define LABEL_IS_SUN    0
#define STATIC_SUN extern
#endif

#if ENABLE_FEATURE_SGI_LABEL
#define LABEL_IS_SGI    (label_sgi == current_label_type)
#define STATIC_SGI static
#else
#define LABEL_IS_SGI    0
#define STATIC_SGI extern
#endif

#if ENABLE_FEATURE_AIX_LABEL
#define LABEL_IS_AIX    (label_aix == current_label_type)
#define STATIC_AIX static
#else
#define LABEL_IS_AIX    0
#define STATIC_AIX extern
#endif

#if ENABLE_FEATURE_OSF_LABEL
#define LABEL_IS_OSF    (label_osf == current_label_type)
#define STATIC_OSF static
#else
#define LABEL_IS_OSF    0
#define STATIC_OSF extern
#endif

enum action { fdisk, require, try_only, create_empty_dos, create_empty_sun };

static enum label_type current_label_type;

static const char *disk_device;
static int fd;                  /* the disk */
static int partitions = 4;      /* maximum partition + 1 */
static int display_in_cyl_units = 1;
static unsigned units_per_sector = 1;
#if ENABLE_FEATURE_FDISK_WRITABLE
static void change_units(void);
static void reread_partition_table(int leave);
static void delete_partition(int i);
static int get_partition(int warn, int max);
static void list_types(const char *const *sys);
static unsigned read_int(unsigned low, unsigned dflt, unsigned high, unsigned base, const char *mesg);
#endif
static const char *partition_type(unsigned char type);
static void get_geometry(void);
static int get_boot(enum action what);

#define PLURAL   0
#define SINGULAR 1

static unsigned get_start_sect(const struct partition *p);
static unsigned get_nr_sects(const struct partition *p);

/*
 * per partition table entry data
 *
 * The four primary partitions have the same sectorbuffer (MBRbuffer)
 * and have NULL ext_pointer.
 * Each logical partition table entry has two pointers, one for the
 * partition and one link to the next one.
 */
struct pte {
    struct partition *part_table;   /* points into sectorbuffer */
    struct partition *ext_pointer;  /* points into sectorbuffer */
    ullong offset;          /* disk sector number */
    char *sectorbuffer;     /* disk sector contents */
#if ENABLE_FEATURE_FDISK_WRITABLE
    char changed;           /* boolean */
#endif
};

/* DOS partition types */

static const char *const i386_sys_types[] = {
    "\x00" "Empty",
    "\x01" "FAT12",
    "\x04" "FAT16 <32M",
    "\x05" "Extended",         /* DOS 3.3+ extended partition */
    "\x06" "FAT16",            /* DOS 16-bit >=32M */
    "\x07" "HPFS/NTFS",        /* OS/2 IFS, eg, HPFS or NTFS or QNX */
    "\x0a" "OS/2 Boot Manager",/* OS/2 Boot Manager */
    "\x0b" "Win95 FAT32",
    "\x0c" "Win95 FAT32 (LBA)",/* LBA really is 'Extended Int 13h' */
    "\x0e" "Win95 FAT16 (LBA)",
    "\x0f" "Win95 Ext'd (LBA)",
    "\x11" "Hidden FAT12",
    "\x12" "Compaq diagnostics",
    "\x14" "Hidden FAT16 <32M",
    "\x16" "Hidden FAT16",
    "\x17" "Hidden HPFS/NTFS",
    "\x1b" "Hidden Win95 FAT32",
    "\x1c" "Hidden W95 FAT32 (LBA)",
    "\x1e" "Hidden W95 FAT16 (LBA)",
    "\x3c" "Part.Magic recovery",
    "\x41" "PPC PReP Boot",
    "\x42" "SFS",
    "\x63" "GNU HURD or SysV", /* GNU HURD or Mach or Sys V/386 (such as ISC UNIX) */
    "\x80" "Old Minix",        /* Minix 1.4a and earlier */
    "\x81" "Minix / old Linux",/* Minix 1.4b and later */
    "\x82" "Linux swap",       /* also Solaris */
    "\x83" "Linux",
    "\x84" "OS/2 hidden C: drive",
    "\x85" "Linux extended",
    "\x86" "NTFS volume set",
    "\x87" "NTFS volume set",
    "\x8e" "Linux LVM",
    "\x9f" "BSD/OS",           /* BSDI */
    "\xa0" "Thinkpad hibernation",
    "\xa5" "FreeBSD",          /* various BSD flavours */
    "\xa6" "OpenBSD",
    "\xa8" "Darwin UFS",
    "\xa9" "NetBSD",
    "\xab" "Darwin boot",
    "\xb7" "BSDI fs",
    "\xb8" "BSDI swap",
    "\xbe" "Solaris boot",
    "\xeb" "BeOS fs",
    "\xee" "EFI GPT",                    /* Intel EFI GUID Partition Table */
    "\xef" "EFI (FAT-12/16/32)",         /* Intel EFI System Partition */
    "\xf0" "Linux/PA-RISC boot",         /* Linux/PA-RISC boot loader */
    "\xf2" "DOS secondary",              /* DOS 3.3+ secondary */
    "\xfd" "Linux raid autodetect",      /* New (2.2.x) raid partition with
                        autodetect using persistent
                        superblock */
#if 0 /* ENABLE_WEIRD_PARTITION_TYPES */
    "\x02" "XENIX root",
    "\x03" "XENIX usr",
    "\x08" "AIX",              /* AIX boot (AIX -- PS/2 port) or SplitDrive */
    "\x09" "AIX bootable",     /* AIX data or Coherent */
    "\x10" "OPUS",
    "\x18" "AST SmartSleep",
    "\x24" "NEC DOS",
    "\x39" "Plan 9",
    "\x40" "Venix 80286",
    "\x4d" "QNX4.x",
    "\x4e" "QNX4.x 2nd part",
    "\x4f" "QNX4.x 3rd part",
    "\x50" "OnTrack DM",
    "\x51" "OnTrack DM6 Aux1", /* (or Novell) */
    "\x52" "CP/M",             /* CP/M or Microport SysV/AT */
    "\x53" "OnTrack DM6 Aux3",
    "\x54" "OnTrackDM6",
    "\x55" "EZ-Drive",
    "\x56" "Golden Bow",
    "\x5c" "Priam Edisk",
    "\x61" "SpeedStor",
    "\x64" "Novell Netware 286",
    "\x65" "Novell Netware 386",
    "\x70" "DiskSecure Multi-Boot",
    "\x75" "PC/IX",
    "\x93" "Amoeba",
    "\x94" "Amoeba BBT",       /* (bad block table) */
    "\xa7" "NeXTSTEP",
    "\xbb" "Boot Wizard hidden",
    "\xc1" "DRDOS/sec (FAT-12)",
    "\xc4" "DRDOS/sec (FAT-16 < 32M)",
    "\xc6" "DRDOS/sec (FAT-16)",
    "\xc7" "Syrinx",
    "\xda" "Non-FS data",
    "\xdb" "CP/M / CTOS / ...",/* CP/M or Concurrent CP/M or
                                  Concurrent DOS or CTOS */
    "\xde" "Dell Utility",     /* Dell PowerEdge Server utilities */
    "\xdf" "BootIt",           /* BootIt EMBRM */
    "\xe1" "DOS access",       /* DOS access or SpeedStor 12-bit FAT
                                  extended partition */
    "\xe3" "DOS R/O",          /* DOS R/O or SpeedStor */
    "\xe4" "SpeedStor",        /* SpeedStor 16-bit FAT extended
                                  partition < 1024 cyl. */
    "\xf1" "SpeedStor",
    "\xf4" "SpeedStor",        /* SpeedStor large partition */
    "\xfe" "LANstep",          /* SpeedStor >1024 cyl. or LANstep */
    "\xff" "BBT",              /* Xenix Bad Block Table */
#endif
    NULL
};


/* Globals */

struct globals {
    char *line_ptr;
    char line_buffer[80];
    char partname_buffer[80];
    jmp_buf listingbuf;
    /* Raw disk label. For DOS-type partition tables the MBR,
     * with descriptions of the primary partitions. */
    char MBRbuffer[MAX_SECTOR_SIZE];
    /* Partition tables */
    struct pte ptes[MAXIMUM_PARTS];
};
/* bb_common_bufsiz1 is too small for this on 64 bit CPUs */
#define G (*ptr_to_globals)

#define line_ptr        (G.line_ptr)
#define listingbuf      (G.listingbuf)
#define line_buffer     (G.line_buffer)
#define partname_buffer (G.partname_buffer)
#define MBRbuffer       (G.MBRbuffer)
#define ptes            (G.ptes)


/* Code */

#define IS_EXTENDED(i) \
    ((i) == EXTENDED || (i) == WIN98_EXTENDED || (i) == LINUX_EXTENDED)

#define cround(n)       (display_in_cyl_units ? ((n)/units_per_sector)+1 : (n))

#define scround(x)      (((x)+units_per_sector-1)/units_per_sector)

#define pt_offset(b, n) \
    ((struct partition *)((b) + 0x1be + (n) * sizeof(struct partition)))

#define sector(s)       ((s) & 0x3f)

#define cylinder(s, c)  ((c) | (((s) & 0xc0) << 2))

#define hsc2sector(h,s,c) \
    (sector(s) - 1 + sectors * ((h) + heads * cylinder(s,c)))

#define set_hsc(h,s,c,sector) \
    do { \
        s = sector % sectors + 1;  \
        sector /= sectors;         \
        h = sector % heads;        \
        sector /= heads;           \
        c = sector & 0xff;         \
        s |= (sector >> 2) & 0xc0; \
    } while (0)

#if ENABLE_FEATURE_FDISK_WRITABLE
/* read line; return 0 or first printable char */
static int
read_line(const char *prompt)
{
    int sz;

    sz = read_line_input(prompt, line_buffer, sizeof(line_buffer), NULL);
    if (sz <= 0)
        exit(0); /* Ctrl-D or Ctrl-C */

    if (line_buffer[sz-1] == '\n')
        line_buffer[--sz] = '\0';

    line_ptr = line_buffer;
    while (*line_ptr && !isgraph(*line_ptr))
        line_ptr++;
    return *line_ptr;
}
#endif

/*
 * return partition name - uses static storage
 */
static const char *
partname(const char *dev, int pno, int lth)
{
    const char *p;
    int w, wp;
    int bufsiz;
    char *bufp;

    bufp = partname_buffer;
    bufsiz = sizeof(partname_buffer);

    w = strlen(dev);
    p = "";

    if (isdigit(dev[w-1]))
        p = "p";

    /* devfs kludge - note: fdisk partition names are not supposed
       to equal kernel names, so there is no reason to do this */
    if (strcmp(dev + w - 4, "disc") == 0) {
        w -= 4;
        p = "part";
    }

    wp = strlen(p);

    if (lth) {
        snprintf(bufp, bufsiz, "%*.*s%s%-2u",
             lth-wp-2, w, dev, p, pno);
    } else {
        snprintf(bufp, bufsiz, "%.*s%s%-2u", w, dev, p, pno);
    }
    return bufp;
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
set_all_unchanged(void)
{
    int i;

    for (i = 0; i < MAXIMUM_PARTS; i++)
        ptes[i].changed = 0;
}

static ALWAYS_INLINE void
set_changed(int i)
{
    ptes[i].changed = 1;
}
#endif /* FEATURE_FDISK_WRITABLE */

static ALWAYS_INLINE struct partition *
get_part_table(int i)
{
    return ptes[i].part_table;
}

static const char *
str_units(int n)
{      /* n==1: use singular */
    if (n == 1)
        return display_in_cyl_units ? "cylinder" : "sector";
    return display_in_cyl_units ? "cylinders" : "sectors";
}

static int
valid_part_table_flag(const char *mbuffer)
{
    return (mbuffer[510] == 0x55 && (uint8_t)mbuffer[511] == 0xaa);
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static ALWAYS_INLINE void
write_part_table_flag(char *b)
{
    b[510] = 0x55;
    b[511] = 0xaa;
}

static char
read_nonempty(const char *mesg)
{
    while (!read_line(mesg)) /* repeat */;
    return *line_ptr;
}

static char
read_maybe_empty(const char *mesg)
{
    if (!read_line(mesg)) {
        line_ptr = line_buffer;
        line_ptr[0] = '\n';
        line_ptr[1] = '\0';
    }
    return line_ptr[0];
}

static int
read_hex(const char *const *sys)
{
    unsigned long v;
    while (1) {
        read_nonempty("Hex code (type L to list codes): ");
        if (*line_ptr == 'l' || *line_ptr == 'L') {
            list_types(sys);
            continue;
        }
        v = bb_strtoul(line_ptr, NULL, 16);
        if (v > 0xff)
            /* Bad input also triggers this */
            continue;
        return v;
    }
}
#endif /* FEATURE_FDISK_WRITABLE */

#include "fdisk_aix.c"

typedef struct {
    unsigned char info[128];   /* Informative text string */
    unsigned char spare0[14];
    struct sun_info {
        unsigned char spare1;
        unsigned char id;
        unsigned char spare2;
        unsigned char flags;
    } infos[8];
    unsigned char spare1[246]; /* Boot information etc. */
    unsigned short rspeed;     /* Disk rotational speed */
    unsigned short pcylcount;  /* Physical cylinder count */
    unsigned short sparecyl;   /* extra sects per cylinder */
    unsigned char spare2[4];   /* More magic... */
    unsigned short ilfact;     /* Interleave factor */
    unsigned short ncyl;       /* Data cylinder count */
    unsigned short nacyl;      /* Alt. cylinder count */
    unsigned short ntrks;      /* Tracks per cylinder */
    unsigned short nsect;      /* Sectors per track */
    unsigned char spare3[4];   /* Even more magic... */
    struct sun_partinfo {
        uint32_t start_cylinder;
        uint32_t num_sectors;
    } partitions[8];
    unsigned short magic;      /* Magic number */
    unsigned short csum;       /* Label xor'd checksum */
} sun_partition;
#define sunlabel ((sun_partition *)MBRbuffer)
STATIC_OSF void bsd_select(void);
STATIC_OSF void xbsd_print_disklabel(int);
#include "fdisk_osf.c"

#if ENABLE_FEATURE_SGI_LABEL || ENABLE_FEATURE_SUN_LABEL
static uint16_t
fdisk_swap16(uint16_t x)
{
    return (x << 8) | (x >> 8);
}

static uint32_t
fdisk_swap32(uint32_t x)
{
    return (x << 24) |
           ((x & 0xFF00) << 8) |
           ((x & 0xFF0000) >> 8) |
           (x >> 24);
}
#endif

STATIC_SGI const char *const sgi_sys_types[];
STATIC_SGI unsigned sgi_get_num_sectors(int i);
STATIC_SGI int sgi_get_sysid(int i);
STATIC_SGI void sgi_delete_partition(int i);
STATIC_SGI void sgi_change_sysid(int i, int sys);
STATIC_SGI void sgi_list_table(int xtra);
#if ENABLE_FEATURE_FDISK_ADVANCED
STATIC_SGI void sgi_set_xcyl(void);
#endif
STATIC_SGI int verify_sgi(int verbose);
STATIC_SGI void sgi_add_partition(int n, int sys);
STATIC_SGI void sgi_set_swappartition(int i);
STATIC_SGI const char *sgi_get_bootfile(void);
STATIC_SGI void sgi_set_bootfile(const char* aFile);
STATIC_SGI void create_sgiinfo(void);
STATIC_SGI void sgi_write_table(void);
STATIC_SGI void sgi_set_bootpartition(int i);
#include "fdisk_sgi.c"

STATIC_SUN const char *const sun_sys_types[];
STATIC_SUN void sun_delete_partition(int i);
STATIC_SUN void sun_change_sysid(int i, int sys);
STATIC_SUN void sun_list_table(int xtra);
STATIC_SUN void add_sun_partition(int n, int sys);
#if ENABLE_FEATURE_FDISK_ADVANCED
STATIC_SUN void sun_set_alt_cyl(void);
STATIC_SUN void sun_set_ncyl(int cyl);
STATIC_SUN void sun_set_xcyl(void);
STATIC_SUN void sun_set_ilfact(void);
STATIC_SUN void sun_set_rspeed(void);
STATIC_SUN void sun_set_pcylcount(void);
#endif
STATIC_SUN void toggle_sunflags(int i, unsigned char mask);
STATIC_SUN void verify_sun(void);
STATIC_SUN void sun_write_table(void);
#include "fdisk_sun.c"

#if ENABLE_FEATURE_FDISK_WRITABLE
/* start_sect and nr_sects are stored little endian on all machines */
/* moreover, they are not aligned correctly */
static void
store4_little_endian(unsigned char *cp, unsigned val)
{
    cp[0] = val;
    cp[1] = val >> 8;
    cp[2] = val >> 16;
    cp[3] = val >> 24;
}
#endif /* FEATURE_FDISK_WRITABLE */

static unsigned
read4_little_endian(const unsigned char *cp)
{
    return cp[0] + (cp[1] << 8) + (cp[2] << 16) + (cp[3] << 24);
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
set_start_sect(struct partition *p, unsigned start_sect)
{
    store4_little_endian(p->start4, start_sect);
}
#endif

static unsigned
get_start_sect(const struct partition *p)
{
    return read4_little_endian(p->start4);
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
set_nr_sects(struct partition *p, unsigned nr_sects)
{
    store4_little_endian(p->size4, nr_sects);
}
#endif

static unsigned
get_nr_sects(const struct partition *p)
{
    return read4_little_endian(p->size4);
}

/* normally O_RDWR, -l option gives O_RDONLY */
static int type_open = O_RDWR;

static int ext_index;               /* the prime extended partition */
static int listing;                 /* no aborts for fdisk -l */
static int dos_compatible_flag = ~0;
#if ENABLE_FEATURE_FDISK_WRITABLE
static int dos_changed;
static int nowarn;            /* no warnings for fdisk -l/-s */
#endif

static unsigned user_cylinders, user_heads, user_sectors;
static unsigned pt_heads, pt_sectors;
static unsigned kern_heads, kern_sectors;

static ullong extended_offset;            /* offset of link pointers */
static ullong total_number_of_sectors;

static void fdisk_fatal(const char *why)
{
    if (listing) {
        close(fd);
        longjmp(listingbuf, 1);
    }
    bb_error_msg_and_die(why, disk_device);
}

static void
seek_sector(ullong secno)
{
    secno *= sector_size;
#if ENABLE_FDISK_SUPPORT_LARGE_DISKS
    if (lseek64(fd, (off64_t)secno, SEEK_SET) == (off64_t) -1)
        fdisk_fatal(unable_to_seek);
#else
    if (secno > MAXINT(off_t)
     || lseek(fd, (off_t)secno, SEEK_SET) == (off_t) -1
    ) {
        fdisk_fatal(unable_to_seek);
    }
#endif
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
write_sector(ullong secno, char *buf)
{
    seek_sector(secno);
    if (write(fd, buf, sector_size) != sector_size)
        fdisk_fatal(unable_to_write);
}
#endif

/* Allocate a buffer and read a partition table sector */
static void
read_pte(struct pte *pe, ullong offset)
{
    pe->offset = offset;
    pe->sectorbuffer = xmalloc(sector_size);
    seek_sector(offset);
    if (read(fd, pe->sectorbuffer, sector_size) != sector_size)
        fdisk_fatal(unable_to_read);
#if ENABLE_FEATURE_FDISK_WRITABLE
    pe->changed = 0;
#endif
    pe->part_table = pe->ext_pointer = NULL;
}

static unsigned
get_partition_start(const struct pte *pe)
{
    return pe->offset + get_start_sect(pe->part_table);
}

#if ENABLE_FEATURE_FDISK_WRITABLE
/*
 * Avoid warning about DOS partitions when no DOS partition was changed.
 * Here a heuristic "is probably dos partition".
 * We might also do the opposite and warn in all cases except
 * for "is probably nondos partition".
 */
static int
is_dos_partition(int t)
{
    return (t == 1 || t == 4 || t == 6 ||
        t == 0x0b || t == 0x0c || t == 0x0e ||
        t == 0x11 || t == 0x12 || t == 0x14 || t == 0x16 ||
        t == 0x1b || t == 0x1c || t == 0x1e || t == 0x24 ||
        t == 0xc1 || t == 0xc4 || t == 0xc6);
}

static void
menu(void)
{
    puts("Command Action");
    if (LABEL_IS_SUN) {
        puts("a\ttoggle a read only flag");           /* sun */
        puts("b\tedit bsd disklabel");
        puts("c\ttoggle the mountable flag");         /* sun */
        puts("d\tdelete a partition");
        puts("l\tlist known partition types");
        puts("n\tadd a new partition");
        puts("o\tcreate a new empty DOS partition table");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("s\tcreate a new empty Sun disklabel");  /* sun */
        puts("t\tchange a partition's system id");
        puts("u\tchange display/entry units");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
#if ENABLE_FEATURE_FDISK_ADVANCED
        puts("x\textra functionality (experts only)");
#endif
    } else if (LABEL_IS_SGI) {
        puts("a\tselect bootable partition");    /* sgi flavour */
        puts("b\tedit bootfile entry");          /* sgi */
        puts("c\tselect sgi swap partition");    /* sgi flavour */
        puts("d\tdelete a partition");
        puts("l\tlist known partition types");
        puts("n\tadd a new partition");
        puts("o\tcreate a new empty DOS partition table");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("s\tcreate a new empty Sun disklabel");  /* sun */
        puts("t\tchange a partition's system id");
        puts("u\tchange display/entry units");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
    } else if (LABEL_IS_AIX) {
        puts("o\tcreate a new empty DOS partition table");
        puts("q\tquit without saving changes");
        puts("s\tcreate a new empty Sun disklabel");  /* sun */
    } else {
        puts("a\ttoggle a bootable flag");
        puts("b\tedit bsd disklabel");
        puts("c\ttoggle the dos compatibility flag");
        puts("d\tdelete a partition");
        puts("l\tlist known partition types");
        puts("n\tadd a new partition");
        puts("o\tcreate a new empty DOS partition table");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("s\tcreate a new empty Sun disklabel");  /* sun */
        puts("t\tchange a partition's system id");
        puts("u\tchange display/entry units");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
#if ENABLE_FEATURE_FDISK_ADVANCED
        puts("x\textra functionality (experts only)");
#endif
    }
}
#endif /* FEATURE_FDISK_WRITABLE */


#if ENABLE_FEATURE_FDISK_ADVANCED
static void
xmenu(void)
{
    puts("Command Action");
    if (LABEL_IS_SUN) {
        puts("a\tchange number of alternate cylinders");      /*sun*/
        puts("c\tchange number of cylinders");
        puts("d\tprint the raw data in the partition table");
        puts("e\tchange number of extra sectors per cylinder");/*sun*/
        puts("h\tchange number of heads");
        puts("i\tchange interleave factor");                  /*sun*/
        puts("o\tchange rotation speed (rpm)");               /*sun*/
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("r\treturn to main menu");
        puts("s\tchange number of sectors/track");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
        puts("y\tchange number of physical cylinders");       /*sun*/
    } else if (LABEL_IS_SGI) {
        puts("b\tmove beginning of data in a partition"); /* !sun */
        puts("c\tchange number of cylinders");
        puts("d\tprint the raw data in the partition table");
        puts("e\tlist extended partitions");          /* !sun */
        puts("g\tcreate an IRIX (SGI) partition table");/* sgi */
        puts("h\tchange number of heads");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("r\treturn to main menu");
        puts("s\tchange number of sectors/track");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
    } else if (LABEL_IS_AIX) {
        puts("b\tmove beginning of data in a partition"); /* !sun */
        puts("c\tchange number of cylinders");
        puts("d\tprint the raw data in the partition table");
        puts("e\tlist extended partitions");          /* !sun */
        puts("g\tcreate an IRIX (SGI) partition table");/* sgi */
        puts("h\tchange number of heads");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("r\treturn to main menu");
        puts("s\tchange number of sectors/track");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
    } else {
        puts("b\tmove beginning of data in a partition"); /* !sun */
        puts("c\tchange number of cylinders");
        puts("d\tprint the raw data in the partition table");
        puts("e\tlist extended partitions");          /* !sun */
        puts("f\tfix partition order");               /* !sun, !aix, !sgi */
#if ENABLE_FEATURE_SGI_LABEL
        puts("g\tcreate an IRIX (SGI) partition table");/* sgi */
#endif
        puts("h\tchange number of heads");
        puts("p\tprint the partition table");
        puts("q\tquit without saving changes");
        puts("r\treturn to main menu");
        puts("s\tchange number of sectors/track");
        puts("v\tverify the partition table");
        puts("w\twrite table to disk and exit");
    }
}
#endif /* ADVANCED mode */

#if ENABLE_FEATURE_FDISK_WRITABLE
static const char *const *
get_sys_types(void)
{
    return (
        LABEL_IS_SUN ? sun_sys_types :
        LABEL_IS_SGI ? sgi_sys_types :
        i386_sys_types);
}
#else
#define get_sys_types() i386_sys_types
#endif /* FEATURE_FDISK_WRITABLE */

static const char *
partition_type(unsigned char type)
{
    int i;
    const char *const *types = get_sys_types();

    for (i = 0; types[i]; i++)
        if ((unsigned char)types[i][0] == type)
            return types[i] + 1;

    return "Unknown";
}


#if ENABLE_FEATURE_FDISK_WRITABLE
static int
get_sysid(int i)
{
    return LABEL_IS_SUN ? sunlabel->infos[i].id :
            (LABEL_IS_SGI ? sgi_get_sysid(i) :
                ptes[i].part_table->sys_ind);
}

static void
list_types(const char *const *sys)
{
    enum { COLS = 3 };

    unsigned last[COLS];
    unsigned done, next, size;
    int i;

    for (size = 0; sys[size]; size++) /* */;

    done = 0;
    for (i = COLS-1; i >= 0; i--) {
        done += (size + i - done) / (i + 1);
        last[COLS-1 - i] = done;
    }

    i = done = next = 0;
    do {
        printf("%c%2x %-22.22s", i ? ' ' : '\n',
            (unsigned char)sys[next][0],
            sys[next] + 1);
        next = last[i++] + done;
        if (i >= COLS || next >= last[i]) {
            i = 0;
            next = ++done;
        }
    } while (done < last[0]);
    putchar('\n');
}
#endif /* FEATURE_FDISK_WRITABLE */

static int
is_cleared_partition(const struct partition *p)
{
    return !(!p || p->boot_ind || p->head || p->sector || p->cyl ||
         p->sys_ind || p->end_head || p->end_sector || p->end_cyl ||
         get_start_sect(p) || get_nr_sects(p));
}

static void
clear_partition(struct partition *p)
{
    if (!p)
        return;
    memset(p, 0, sizeof(struct partition));
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
set_partition(int i, int doext, ullong start, ullong stop, int sysid)
{
    struct partition *p;
    ullong offset;

    if (doext) {
        p = ptes[i].ext_pointer;
        offset = extended_offset;
    } else {
        p = ptes[i].part_table;
        offset = ptes[i].offset;
    }
    p->boot_ind = 0;
    p->sys_ind = sysid;
    set_start_sect(p, start - offset);
    set_nr_sects(p, stop - start + 1);
    if (dos_compatible_flag && (start/(sectors*heads) > 1023))
        start = heads*sectors*1024 - 1;
    set_hsc(p->head, p->sector, p->cyl, start);
    if (dos_compatible_flag && (stop/(sectors*heads) > 1023))
        stop = heads*sectors*1024 - 1;
    set_hsc(p->end_head, p->end_sector, p->end_cyl, stop);
    ptes[i].changed = 1;
}
#endif

static int
warn_geometry(void)
{
    if (heads && sectors && cylinders)
        return 0;

    printf("Unknown value(s) for:");
    if (!heads)
        printf(" heads");
    if (!sectors)
        printf(" sectors");
    if (!cylinders)
        printf(" cylinders");
    printf(
#if ENABLE_FEATURE_FDISK_WRITABLE
        " (settable in the extra functions menu)"
#endif
        "\n");
    return 1;
}

static void
update_units(void)
{
    int cyl_units = heads * sectors;

    if (display_in_cyl_units && cyl_units)
        units_per_sector = cyl_units;
    else
        units_per_sector = 1;   /* in sectors */
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
warn_cylinders(void)
{
    if (LABEL_IS_DOS && cylinders > 1024 && !nowarn)
        printf("\n"
"The number of cylinders for this disk is set to %d.\n"
"There is nothing wrong with that, but this is larger than 1024,\n"
"and could in certain setups cause problems with:\n"
"1) software that runs at boot time (e.g., old versions of LILO)\n"
"2) booting and partitioning software from other OSs\n"
"   (e.g., DOS FDISK, OS/2 FDISK)\n",
            cylinders);
}
#endif

static void
read_extended(int ext)
{
    int i;
    struct pte *pex;
    struct partition *p, *q;

    ext_index = ext;
    pex = &ptes[ext];
    pex->ext_pointer = pex->part_table;

    p = pex->part_table;
    if (!get_start_sect(p)) {
        printf("Bad offset in primary extended partition\n");
        return;
    }

    while (IS_EXTENDED(p->sys_ind)) {
        struct pte *pe = &ptes[partitions];

        if (partitions >= MAXIMUM_PARTS) {
            /* This is not a Linux restriction, but
               this program uses arrays of size MAXIMUM_PARTS.
               Do not try to 'improve' this test. */
            struct pte *pre = &ptes[partitions-1];
#if ENABLE_FEATURE_FDISK_WRITABLE
            printf("Warning: deleting partitions after %d\n",
                partitions);
            pre->changed = 1;
#endif
            clear_partition(pre->ext_pointer);
            return;
        }

        read_pte(pe, extended_offset + get_start_sect(p));

        if (!extended_offset)
            extended_offset = get_start_sect(p);

        q = p = pt_offset(pe->sectorbuffer, 0);
        for (i = 0; i < 4; i++, p++) if (get_nr_sects(p)) {
            if (IS_EXTENDED(p->sys_ind)) {
                if (pe->ext_pointer)
                    printf("Warning: extra link "
                        "pointer in partition table"
                        " %d\n", partitions + 1);
                else
                    pe->ext_pointer = p;
            } else if (p->sys_ind) {
                if (pe->part_table)
                    printf("Warning: ignoring extra "
                          "data in partition table"
                          " %d\n", partitions + 1);
                else
                    pe->part_table = p;
            }
        }

        /* very strange code here... */
        if (!pe->part_table) {
            if (q != pe->ext_pointer)
                pe->part_table = q;
            else
                pe->part_table = q + 1;
        }
        if (!pe->ext_pointer) {
            if (q != pe->part_table)
                pe->ext_pointer = q;
            else
                pe->ext_pointer = q + 1;
        }

        p = pe->ext_pointer;
        partitions++;
    }

#if ENABLE_FEATURE_FDISK_WRITABLE
    /* remove empty links */
 remove:
    for (i = 4; i < partitions; i++) {
        struct pte *pe = &ptes[i];

        if (!get_nr_sects(pe->part_table)
         && (partitions > 5 || ptes[4].part_table->sys_ind)
        ) {
            printf("Omitting empty partition (%d)\n", i+1);
            delete_partition(i);
            goto remove;    /* numbering changed */
        }
    }
#endif
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
create_doslabel(void)
{
    int i;

    printf(msg_building_new_label, "DOS disklabel");

    current_label_type = label_dos;

#if ENABLE_FEATURE_OSF_LABEL
    possibly_osf_label = 0;
#endif
    partitions = 4;

    for (i = 510-64; i < 510; i++)
        MBRbuffer[i] = 0;
    write_part_table_flag(MBRbuffer);
    extended_offset = 0;
    set_all_unchanged();
    set_changed(0);
    get_boot(create_empty_dos);
}
#endif /* FEATURE_FDISK_WRITABLE */

static void
get_sectorsize(void)
{
    if (!user_set_sector_size) {
        int arg;
        if (ioctl(fd, BLKSSZGET, &arg) == 0)
            sector_size = arg;
        if (sector_size != DEFAULT_SECTOR_SIZE)
            printf("Note: sector size is %d (not %d)\n",
                   sector_size, DEFAULT_SECTOR_SIZE);
    }
}

static void
get_kernel_geometry(void)
{
    struct hd_geometry geometry;

    if (!ioctl(fd, HDIO_GETGEO, &geometry)) {
        kern_heads = geometry.heads;
        kern_sectors = geometry.sectors;
        /* never use geometry.cylinders - it is truncated */
    }
}

static void
get_partition_table_geometry(void)
{
    const unsigned char *bufp = (const unsigned char *)MBRbuffer;
    struct partition *p;
    int i, h, s, hh, ss;
    int first = 1;
    int bad = 0;

    if (!(valid_part_table_flag((char*)bufp)))
        return;

    hh = ss = 0;
    for (i = 0; i < 4; i++) {
        p = pt_offset(bufp, i);
        if (p->sys_ind != 0) {
            h = p->end_head + 1;
            s = (p->end_sector & 077);
            if (first) {
                hh = h;
                ss = s;
                first = 0;
            } else if (hh != h || ss != s)
                bad = 1;
        }
    }

    if (!first && !bad) {
        pt_heads = hh;
        pt_sectors = ss;
    }
}

static void
get_geometry(void)
{
    int sec_fac;
    uint64_t v64;

    get_sectorsize();
    sec_fac = sector_size / 512;
#if ENABLE_FEATURE_SUN_LABEL
    guess_device_type();
#endif
    heads = cylinders = sectors = 0;
    kern_heads = kern_sectors = 0;
    pt_heads = pt_sectors = 0;

    get_kernel_geometry();
    get_partition_table_geometry();

    heads = user_heads ? user_heads :
        pt_heads ? pt_heads :
        kern_heads ? kern_heads : 255;
    sectors = user_sectors ? user_sectors :
        pt_sectors ? pt_sectors :
        kern_sectors ? kern_sectors : 63;
    if (ioctl(fd, BLKGETSIZE64, &v64) == 0) {
        /* got bytes, convert to 512 byte sectors */
        total_number_of_sectors = (v64 >> 9);
    } else {
        unsigned long longsectors; /* need temp of type long */
        if (ioctl(fd, BLKGETSIZE, &longsectors))
            longsectors = 0;
        total_number_of_sectors = longsectors;
    }

    sector_offset = 1;
    if (dos_compatible_flag)
        sector_offset = sectors;

    cylinders = total_number_of_sectors / (heads * sectors * sec_fac);
    if (!cylinders)
        cylinders = user_cylinders;
}

/*
 * Read MBR.  Returns:
 *   -1: no 0xaa55 flag present (possibly entire disk BSD)
 *    0: found or created label
 *    1: I/O error
 */
static int
get_boot(enum action what)
{
    int i;

    partitions = 4;

    for (i = 0; i < 4; i++) {
        struct pte *pe = &ptes[i];

        pe->part_table = pt_offset(MBRbuffer, i);
        pe->ext_pointer = NULL;
        pe->offset = 0;
        pe->sectorbuffer = MBRbuffer;
#if ENABLE_FEATURE_FDISK_WRITABLE
        pe->changed = (what == create_empty_dos);
#endif
    }

#if ENABLE_FEATURE_SUN_LABEL
    if (what == create_empty_sun && check_sun_label())
        return 0;
#endif

    memset(MBRbuffer, 0, 512);

#if ENABLE_FEATURE_FDISK_WRITABLE
    if (what == create_empty_dos)
        goto got_dos_table;             /* skip reading disk */

    fd = open(disk_device, type_open);
    if (fd < 0) {
        fd = open(disk_device, O_RDONLY);
        if (fd < 0) {
            if (what == try_only)
                return 1;
            fdisk_fatal(unable_to_open);
        } else
            printf("You will not be able to write "
                "the partition table\n");
    }

    if (512 != read(fd, MBRbuffer, 512)) {
        if (what == try_only)
            return 1;
        fdisk_fatal(unable_to_read);
    }
#else
    fd = open(disk_device, O_RDONLY);
    if (fd < 0)
        return 1;
    if (512 != read(fd, MBRbuffer, 512))
        return 1;
#endif

    get_geometry();

    update_units();

#if ENABLE_FEATURE_SUN_LABEL
    if (check_sun_label())
        return 0;
#endif

#if ENABLE_FEATURE_SGI_LABEL
    if (check_sgi_label())
        return 0;
#endif

#if ENABLE_FEATURE_AIX_LABEL
    if (check_aix_label())
        return 0;
#endif

#if ENABLE_FEATURE_OSF_LABEL
    if (check_osf_label()) {
        possibly_osf_label = 1;
        if (!valid_part_table_flag(MBRbuffer)) {
            current_label_type = label_osf;
            return 0;
        }
        printf("This disk has both DOS and BSD magic.\n"
             "Give the 'b' command to go to BSD mode.\n");
    }
#endif

#if ENABLE_FEATURE_FDISK_WRITABLE
 got_dos_table:
#endif

    if (!valid_part_table_flag(MBRbuffer)) {
#if !ENABLE_FEATURE_FDISK_WRITABLE
        return -1;
#else
        switch (what) {
        case fdisk:
            printf("Device contains neither a valid DOS "
                  "partition table, nor Sun, SGI or OSF "
                  "disklabel\n");
#ifdef __sparc__
#if ENABLE_FEATURE_SUN_LABEL
            create_sunlabel();
#endif
#else
            create_doslabel();
#endif
            return 0;
        case try_only:
            return -1;
        case create_empty_dos:
#if ENABLE_FEATURE_SUN_LABEL
        case create_empty_sun:
#endif
            break;
        default:
            bb_error_msg_and_die("internal error");
        }
#endif /* FEATURE_FDISK_WRITABLE */
    }

#if ENABLE_FEATURE_FDISK_WRITABLE
    warn_cylinders();
#endif
    warn_geometry();

    for (i = 0; i < 4; i++) {
        struct pte *pe = &ptes[i];

        if (IS_EXTENDED(pe->part_table->sys_ind)) {
            if (partitions != 4)
                printf("Ignoring extra extended "
                    "partition %d\n", i + 1);
            else
                read_extended(i);
        }
    }

    for (i = 3; i < partitions; i++) {
        struct pte *pe = &ptes[i];

        if (!valid_part_table_flag(pe->sectorbuffer)) {
            printf("Warning: invalid flag 0x%02x,0x%02x of partition "
                "table %d will be corrected by w(rite)\n",
                pe->sectorbuffer[510],
                pe->sectorbuffer[511],
                i + 1);
#if ENABLE_FEATURE_FDISK_WRITABLE
            pe->changed = 1;
#endif
        }
    }

    return 0;
}

#if ENABLE_FEATURE_FDISK_WRITABLE
/*
 * Print the message MESG, then read an integer between LOW and HIGH (inclusive).
 * If the user hits Enter, DFLT is returned.
 * Answers like +10 are interpreted as offsets from BASE.
 *
 * There is no default if DFLT is not between LOW and HIGH.
 */
static unsigned
read_int(unsigned low, unsigned dflt, unsigned high, unsigned base, const char *mesg)
{
    unsigned i;
    int default_ok = 1;
    const char *fmt = "%s (%u-%u, default %u): ";

    if (dflt < low || dflt > high) {
        fmt = "%s (%u-%u): ";
        default_ok = 0;
    }

    while (1) {
        int use_default = default_ok;

        /* ask question and read answer */
        do {
            printf(fmt, mesg, low, high, dflt);
            read_maybe_empty("");
        } while (*line_ptr != '\n' && !isdigit(*line_ptr)
         && *line_ptr != '-' && *line_ptr != '+');

        if (*line_ptr == '+' || *line_ptr == '-') {
            int minus = (*line_ptr == '-');
            int absolute = 0;

            i = atoi(line_ptr + 1);

            while (isdigit(*++line_ptr))
                use_default = 0;

            switch (*line_ptr) {
            case 'c':
            case 'C':
                if (!display_in_cyl_units)
                    i *= heads * sectors;
                break;
            case 'K':
                absolute = 1024;
                break;
            case 'k':
                absolute = 1000;
                break;
            case 'm':
            case 'M':
                absolute = 1000000;
                break;
            case 'g':
            case 'G':
                absolute = 1000000000;
                break;
            default:
                break;
            }
            if (absolute) {
                ullong bytes;
                unsigned long unit;

                bytes = (ullong) i * absolute;
                unit = sector_size * units_per_sector;
                bytes += unit/2; /* round */
                bytes /= unit;
                i = bytes;
            }
            if (minus)
                i = -i;
            i += base;
        } else {
            i = atoi(line_ptr);
            while (isdigit(*line_ptr)) {
                line_ptr++;
                use_default = 0;
            }
        }
        if (use_default) {
            i = dflt;
            printf("Using default value %u\n", i);
        }
        if (i >= low && i <= high)
            break;
        printf("Value is out of range\n");
    }
    return i;
}

static int
get_partition(int warn, int max)
{
    struct pte *pe;
    int i;

    i = read_int(1, 0, max, 0, "Partition number") - 1;
    pe = &ptes[i];

    if (warn) {
        if ((!LABEL_IS_SUN && !LABEL_IS_SGI && !pe->part_table->sys_ind)
         || (LABEL_IS_SUN && (!sunlabel->partitions[i].num_sectors || !sunlabel->infos[i].id))
         || (LABEL_IS_SGI && !sgi_get_num_sectors(i))
        ) {
            printf("Warning: partition %d has empty type\n", i+1);
        }
    }
    return i;
}

static int
get_existing_partition(int warn, int max)
{
    int pno = -1;
    int i;

    for (i = 0; i < max; i++) {
        struct pte *pe = &ptes[i];
        struct partition *p = pe->part_table;

        if (p && !is_cleared_partition(p)) {
            if (pno >= 0)
                goto not_unique;
            pno = i;
        }
    }
    if (pno >= 0) {
        printf("Selected partition %d\n", pno+1);
        return pno;
    }
    printf("No partition is defined yet!\n");
    return -1;

 not_unique:
    return get_partition(warn, max);
}

static int
get_nonexisting_partition(int warn, int max)
{
    int pno = -1;
    int i;

    for (i = 0; i < max; i++) {
        struct pte *pe = &ptes[i];
        struct partition *p = pe->part_table;

        if (p && is_cleared_partition(p)) {
            if (pno >= 0)
                goto not_unique;
            pno = i;
        }
    }
    if (pno >= 0) {
        printf("Selected partition %d\n", pno+1);
        return pno;
    }
    printf("All primary partitions have been defined already!\n");
    return -1;

 not_unique:
    return get_partition(warn, max);
}


static void
change_units(void)
{
    display_in_cyl_units = !display_in_cyl_units;
    update_units();
    printf("Changing display/entry units to %s\n",
        str_units(PLURAL));
}

static void
toggle_active(int i)
{
    struct pte *pe = &ptes[i];
    struct partition *p = pe->part_table;

    if (IS_EXTENDED(p->sys_ind) && !p->boot_ind)
        printf("WARNING: Partition %d is an extended partition\n", i + 1);
    p->boot_ind = (p->boot_ind ? 0 : ACTIVE_FLAG);
    pe->changed = 1;
}

static void
toggle_dos_compatibility_flag(void)
{
    dos_compatible_flag = ~dos_compatible_flag;
    if (dos_compatible_flag) {
        sector_offset = sectors;
        printf("DOS Compatibility flag is set\n");
    } else {
        sector_offset = 1;
        printf("DOS Compatibility flag is not set\n");
    }
}

static void
delete_partition(int i)
{
    struct pte *pe = &ptes[i];
    struct partition *p = pe->part_table;
    struct partition *q = pe->ext_pointer;

/* Note that for the fifth partition (i == 4) we don't actually
 * decrement partitions.
 */

    if (warn_geometry())
        return;         /* C/H/S not set */
    pe->changed = 1;

    if (LABEL_IS_SUN) {
        sun_delete_partition(i);
        return;
    }
    if (LABEL_IS_SGI) {
        sgi_delete_partition(i);
        return;
    }

    if (i < 4) {
        if (IS_EXTENDED(p->sys_ind) && i == ext_index) {
            partitions = 4;
            ptes[ext_index].ext_pointer = NULL;
            extended_offset = 0;
        }
        clear_partition(p);
        return;
    }

    if (!q->sys_ind && i > 4) {
        /* the last one in the chain - just delete */
        --partitions;
        --i;
        clear_partition(ptes[i].ext_pointer);
        ptes[i].changed = 1;
    } else {
        /* not the last one - further ones will be moved down */
        if (i > 4) {
            /* delete this link in the chain */
            p = ptes[i-1].ext_pointer;
            *p = *q;
            set_start_sect(p, get_start_sect(q));
            set_nr_sects(p, get_nr_sects(q));
            ptes[i-1].changed = 1;
        } else if (partitions > 5) {    /* 5 will be moved to 4 */
            /* the first logical in a longer chain */
            pe = &ptes[5];

            if (pe->part_table) /* prevent SEGFAULT */
                set_start_sect(pe->part_table,
                           get_partition_start(pe) -
                           extended_offset);
            pe->offset = extended_offset;
            pe->changed = 1;
        }

        if (partitions > 5) {
            partitions--;
            while (i < partitions) {
                ptes[i] = ptes[i+1];
                i++;
            }
        } else
            /* the only logical: clear only */
            clear_partition(ptes[i].part_table);
    }
}

static void
change_sysid(void)
{
    int i, sys, origsys;
    struct partition *p;

    /* If sgi_label then don't use get_existing_partition,
       let the user select a partition, since get_existing_partition()
       only works for Linux like partition tables. */
    if (!LABEL_IS_SGI) {
        i = get_existing_partition(0, partitions);
    } else {
        i = get_partition(0, partitions);
    }
    if (i == -1)
        return;
    p = ptes[i].part_table;
    origsys = sys = get_sysid(i);

    /* if changing types T to 0 is allowed, then
       the reverse change must be allowed, too */
    if (!sys && !LABEL_IS_SGI && !LABEL_IS_SUN && !get_nr_sects(p)) {
        printf("Partition %d does not exist yet!\n", i + 1);
        return;
    }
    while (1) {
        sys = read_hex(get_sys_types());

        if (!sys && !LABEL_IS_SGI && !LABEL_IS_SUN) {
            printf("Type 0 means free space to many systems\n"
                   "(but not to Linux). Having partitions of\n"
                   "type 0 is probably unwise.\n");
            /* break; */
        }

        if (!LABEL_IS_SUN && !LABEL_IS_SGI) {
            if (IS_EXTENDED(sys) != IS_EXTENDED(p->sys_ind)) {
                printf("You cannot change a partition into"
                       " an extended one or vice versa\n");
                break;
            }
        }

        if (sys < 256) {
#if ENABLE_FEATURE_SUN_LABEL
            if (LABEL_IS_SUN && i == 2 && sys != SUN_WHOLE_DISK)
                printf("Consider leaving partition 3 "
                       "as Whole disk (5),\n"
                       "as SunOS/Solaris expects it and "
                       "even Linux likes it\n\n");
#endif
#if ENABLE_FEATURE_SGI_LABEL
            if (LABEL_IS_SGI &&
                (
                    (i == 10 && sys != SGI_ENTIRE_DISK) ||
                    (i == 8 && sys != 0)
                )
            ) {
                printf("Consider leaving partition 9 "
                       "as volume header (0),\nand "
                       "partition 11 as entire volume (6)"
                       "as IRIX expects it\n\n");
            }
#endif
            if (sys == origsys)
                break;
            if (LABEL_IS_SUN) {
                sun_change_sysid(i, sys);
            } else if (LABEL_IS_SGI) {
                sgi_change_sysid(i, sys);
            } else
                p->sys_ind = sys;

            printf("Changed system type of partition %d "
                "to %x (%s)\n", i + 1, sys,
                partition_type(sys));
            ptes[i].changed = 1;
            if (is_dos_partition(origsys) ||
                is_dos_partition(sys))
                dos_changed = 1;
            break;
        }
    }
}
#endif /* FEATURE_FDISK_WRITABLE */


/* check_consistency() and linear2chs() added Sat Mar 6 12:28:16 1993,
 * faith@cs.unc.edu, based on code fragments from pfdisk by Gordon W. Ross,
 * Jan.  1990 (version 1.2.1 by Gordon W. Ross Aug. 1990; Modified by S.
 * Lubkin Oct.  1991). */

static void
linear2chs(unsigned ls, unsigned *c, unsigned *h, unsigned *s)
{
    int spc = heads * sectors;

    *c = ls / spc;
    ls = ls % spc;
    *h = ls / sectors;
    *s = ls % sectors + 1;  /* sectors count from 1 */
}

static void
check_consistency(const struct partition *p, int partition)
{
    unsigned pbc, pbh, pbs;          /* physical beginning c, h, s */
    unsigned pec, peh, pes;          /* physical ending c, h, s */
    unsigned lbc, lbh, lbs;          /* logical beginning c, h, s */
    unsigned lec, leh, les;          /* logical ending c, h, s */

    if (!heads || !sectors || (partition >= 4))
        return;         /* do not check extended partitions */

/* physical beginning c, h, s */
    pbc = (p->cyl & 0xff) | ((p->sector << 2) & 0x300);
    pbh = p->head;
    pbs = p->sector & 0x3f;

/* physical ending c, h, s */
    pec = (p->end_cyl & 0xff) | ((p->end_sector << 2) & 0x300);
    peh = p->end_head;
    pes = p->end_sector & 0x3f;

/* compute logical beginning (c, h, s) */
    linear2chs(get_start_sect(p), &lbc, &lbh, &lbs);

/* compute logical ending (c, h, s) */
    linear2chs(get_start_sect(p) + get_nr_sects(p) - 1, &lec, &leh, &les);

/* Same physical / logical beginning? */
    if (cylinders <= 1024 && (pbc != lbc || pbh != lbh || pbs != lbs)) {
        printf("Partition %d has different physical/logical "
            "beginnings (non-Linux?):\n", partition + 1);
        printf("     phys=(%d, %d, %d) ", pbc, pbh, pbs);
        printf("logical=(%d, %d, %d)\n",lbc, lbh, lbs);
    }

/* Same physical / logical ending? */
    if (cylinders <= 1024 && (pec != lec || peh != leh || pes != les)) {
        printf("Partition %d has different physical/logical "
            "endings:\n", partition + 1);
        printf("     phys=(%d, %d, %d) ", pec, peh, pes);
        printf("logical=(%d, %d, %d)\n", lec, leh, les);
    }

/* Ending on cylinder boundary? */
    if (peh != (heads - 1) || pes != sectors) {
        printf("Partition %i does not end on cylinder boundary\n",
            partition + 1);
    }
}

static void
list_disk_geometry(void)
{
    long long bytes = (total_number_of_sectors << 9);
    long megabytes = bytes/1000000;

    if (megabytes < 10000)
        printf("\nDisk %s: %ld MB, %lld bytes\n",
               disk_device, megabytes, bytes);
    else
        printf("\nDisk %s: %ld.%ld GB, %lld bytes\n",
               disk_device, megabytes/1000, (megabytes/100)%10, bytes);
    printf("%d heads, %d sectors/track, %d cylinders",
           heads, sectors, cylinders);
    if (units_per_sector == 1)
        printf(", total %llu sectors",
               total_number_of_sectors / (sector_size/512));
    printf("\nUnits = %s of %d * %d = %d bytes\n\n",
           str_units(PLURAL),
           units_per_sector, sector_size, units_per_sector * sector_size);
}

/*
 * Check whether partition entries are ordered by their starting positions.
 * Return 0 if OK. Return i if partition i should have been earlier.
 * Two separate checks: primary and logical partitions.
 */
static int
wrong_p_order(int *prev)
{
    const struct pte *pe;
    const struct partition *p;
    ullong last_p_start_pos = 0, p_start_pos;
    int i, last_i = 0;

    for (i = 0; i < partitions; i++) {
        if (i == 4) {
            last_i = 4;
            last_p_start_pos = 0;
        }
        pe = &ptes[i];
        if ((p = pe->part_table)->sys_ind) {
            p_start_pos = get_partition_start(pe);

            if (last_p_start_pos > p_start_pos) {
                if (prev)
                    *prev = last_i;
                return i;
            }

            last_p_start_pos = p_start_pos;
            last_i = i;
        }
    }
    return 0;
}

#if ENABLE_FEATURE_FDISK_ADVANCED
/*
 * Fix the chain of logicals.
 * extended_offset is unchanged, the set of sectors used is unchanged
 * The chain is sorted so that sectors increase, and so that
 * starting sectors increase.
 *
 * After this it may still be that cfdisk doesnt like the table.
 * (This is because cfdisk considers expanded parts, from link to
 * end of partition, and these may still overlap.)
 * Now
 *   sfdisk /dev/hda > ohda; sfdisk /dev/hda < ohda
 * may help.
 */
static void
fix_chain_of_logicals(void)
{
    int j, oj, ojj, sj, sjj;
    struct partition *pj,*pjj,tmp;

    /* Stage 1: sort sectors but leave sector of part 4 */
    /* (Its sector is the global extended_offset.) */
 stage1:
    for (j = 5; j < partitions-1; j++) {
        oj = ptes[j].offset;
        ojj = ptes[j+1].offset;
        if (oj > ojj) {
            ptes[j].offset = ojj;
            ptes[j+1].offset = oj;
            pj = ptes[j].part_table;
            set_start_sect(pj, get_start_sect(pj)+oj-ojj);
            pjj = ptes[j+1].part_table;
            set_start_sect(pjj, get_start_sect(pjj)+ojj-oj);
            set_start_sect(ptes[j-1].ext_pointer,
                       ojj-extended_offset);
            set_start_sect(ptes[j].ext_pointer,
                       oj-extended_offset);
            goto stage1;
        }
    }

    /* Stage 2: sort starting sectors */
 stage2:
    for (j = 4; j < partitions-1; j++) {
        pj = ptes[j].part_table;
        pjj = ptes[j+1].part_table;
        sj = get_start_sect(pj);
        sjj = get_start_sect(pjj);
        oj = ptes[j].offset;
        ojj = ptes[j+1].offset;
        if (oj+sj > ojj+sjj) {
            tmp = *pj;
            *pj = *pjj;
            *pjj = tmp;
            set_start_sect(pj, ojj+sjj-oj);
            set_start_sect(pjj, oj+sj-ojj);
            goto stage2;
        }
    }

    /* Probably something was changed */
    for (j = 4; j < partitions; j++)
        ptes[j].changed = 1;
}


static void
fix_partition_table_order(void)
{
    struct pte *pei, *pek;
    int i,k;

    if (!wrong_p_order(NULL)) {
        printf("Ordering is already correct\n\n");
        return;
    }

    while ((i = wrong_p_order(&k)) != 0 && i < 4) {
        /* partition i should have come earlier, move it */
        /* We have to move data in the MBR */
        struct partition *pi, *pk, *pe, pbuf;
        pei = &ptes[i];
        pek = &ptes[k];

        pe = pei->ext_pointer;
        pei->ext_pointer = pek->ext_pointer;
        pek->ext_pointer = pe;

        pi = pei->part_table;
        pk = pek->part_table;

        memmove(&pbuf, pi, sizeof(struct partition));
        memmove(pi, pk, sizeof(struct partition));
        memmove(pk, &pbuf, sizeof(struct partition));

        pei->changed = pek->changed = 1;
    }

    if (i)
        fix_chain_of_logicals();

    printf("Done.\n");

}
#endif

static void
list_table(int xtra)
{
    const struct partition *p;
    int i, w;

    if (LABEL_IS_SUN) {
        sun_list_table(xtra);
        return;
    }
    if (LABEL_IS_SUN) {
        sgi_list_table(xtra);
        return;
    }

    list_disk_geometry();

    if (LABEL_IS_OSF) {
        xbsd_print_disklabel(xtra);
        return;
    }

    /* Heuristic: we list partition 3 of /dev/foo as /dev/foo3,
       but if the device name ends in a digit, say /dev/foo1,
       then the partition is called /dev/foo1p3. */
    w = strlen(disk_device);
    if (w && isdigit(disk_device[w-1]))
        w++;
    if (w < 5)
        w = 5;

    //            1 12345678901 12345678901 12345678901  12
    printf("%*s Boot      Start         End      Blocks  Id System\n",
           w+1, "Device");

    for (i = 0; i < partitions; i++) {
        const struct pte *pe = &ptes[i];
        ullong psects;
        ullong pblocks;
        unsigned podd;

        p = pe->part_table;
        if (!p || is_cleared_partition(p))
            continue;

        psects = get_nr_sects(p);
        pblocks = psects;
        podd = 0;

        if (sector_size < 1024) {
            pblocks /= (1024 / sector_size);
            podd = psects % (1024 / sector_size);
        }
        if (sector_size > 1024)
            pblocks *= (sector_size / 1024);

        printf("%s  %c %11llu %11llu %11llu%c %2x %s\n",
            partname(disk_device, i+1, w+2),
            !p->boot_ind ? ' ' : p->boot_ind == ACTIVE_FLAG /* boot flag */
                ? '*' : '?',
            (ullong) cround(get_partition_start(pe)),           /* start */
            (ullong) cround(get_partition_start(pe) + psects    /* end */
                - (psects ? 1 : 0)),
            (ullong) pblocks, podd ? '+' : ' ', /* odd flag on end */
            p->sys_ind,                                     /* type id */
            partition_type(p->sys_ind));                    /* type name */

        check_consistency(p, i);
    }

    /* Is partition table in disk order? It need not be, but... */
    /* partition table entries are not checked for correct order if this
       is a sgi, sun or aix labeled disk... */
    if (LABEL_IS_DOS && wrong_p_order(NULL)) {
        /* FIXME */
        printf("\nPartition table entries are not in disk order\n");
    }
}

#if ENABLE_FEATURE_FDISK_ADVANCED
static void
x_list_table(int extend)
{
    const struct pte *pe;
    const struct partition *p;
    int i;

    printf("\nDisk %s: %d heads, %d sectors, %d cylinders\n\n",
        disk_device, heads, sectors, cylinders);
    printf("Nr AF  Hd Sec  Cyl  Hd Sec  Cyl      Start       Size ID\n");
    for (i = 0; i < partitions; i++) {
        pe = &ptes[i];
        p = (extend ? pe->ext_pointer : pe->part_table);
        if (p != NULL) {
            printf("%2d %02x%4d%4d%5d%4d%4d%5d%11u%11u %02x\n",
                i + 1, p->boot_ind, p->head,
                sector(p->sector),
                cylinder(p->sector, p->cyl), p->end_head,
                sector(p->end_sector),
                cylinder(p->end_sector, p->end_cyl),
                get_start_sect(p), get_nr_sects(p), p->sys_ind);
            if (p->sys_ind)
                check_consistency(p, i);
        }
    }
}
#endif

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
fill_bounds(ullong *first, ullong *last)
{
    int i;
    const struct pte *pe = &ptes[0];
    const struct partition *p;

    for (i = 0; i < partitions; pe++,i++) {
        p = pe->part_table;
        if (!p->sys_ind || IS_EXTENDED(p->sys_ind)) {
            first[i] = 0xffffffff;
            last[i] = 0;
        } else {
            first[i] = get_partition_start(pe);
            last[i] = first[i] + get_nr_sects(p) - 1;
        }
    }
}

static void
check(int n, unsigned h, unsigned s, unsigned c, ullong start)
{
    ullong total, real_s, real_c;

    real_s = sector(s) - 1;
    real_c = cylinder(s, c);
    total = (real_c * sectors + real_s) * heads + h;
    if (!total)
        printf("Partition %d contains sector 0\n", n);
    if (h >= heads)
        printf("Partition %d: head %d greater than maximum %d\n",
            n, h + 1, heads);
    if (real_s >= sectors)
        printf("Partition %d: sector %d greater than "
            "maximum %d\n", n, s, sectors);
    if (real_c >= cylinders)
        printf("Partition %d: cylinder %llu greater than "
            "maximum %d\n", n, real_c + 1, cylinders);
    if (cylinders <= 1024 && start != total)
        printf("Partition %d: previous sectors %llu disagrees with "
            "total %llu\n", n, start, total);
}

static void
verify(void)
{
    int i, j;
    unsigned total = 1;
    ullong first[partitions], last[partitions];
    struct partition *p;

    if (warn_geometry())
        return;

    if (LABEL_IS_SUN) {
        verify_sun();
        return;
    }
    if (LABEL_IS_SGI) {
        verify_sgi(1);
        return;
    }

    fill_bounds(first, last);
    for (i = 0; i < partitions; i++) {
        struct pte *pe = &ptes[i];

        p = pe->part_table;
        if (p->sys_ind && !IS_EXTENDED(p->sys_ind)) {
            check_consistency(p, i);
            if (get_partition_start(pe) < first[i])
                printf("Warning: bad start-of-data in "
                    "partition %d\n", i + 1);
            check(i + 1, p->end_head, p->end_sector, p->end_cyl,
                last[i]);
            total += last[i] + 1 - first[i];
            for (j = 0; j < i; j++) {
                if ((first[i] >= first[j] && first[i] <= last[j])
                 || ((last[i] <= last[j] && last[i] >= first[j]))) {
                    printf("Warning: partition %d overlaps "
                        "partition %d\n", j + 1, i + 1);
                    total += first[i] >= first[j] ?
                        first[i] : first[j];
                    total -= last[i] <= last[j] ?
                        last[i] : last[j];
                }
            }
        }
    }

    if (extended_offset) {
        struct pte *pex = &ptes[ext_index];
        ullong e_last = get_start_sect(pex->part_table) +
            get_nr_sects(pex->part_table) - 1;

        for (i = 4; i < partitions; i++) {
            total++;
            p = ptes[i].part_table;
            if (!p->sys_ind) {
                if (i != 4 || i + 1 < partitions)
                    printf("Warning: partition %d "
                        "is empty\n", i + 1);
            } else if (first[i] < extended_offset || last[i] > e_last) {
                printf("Logical partition %d not entirely in "
                    "partition %d\n", i + 1, ext_index + 1);
            }
        }
    }

    if (total > heads * sectors * cylinders)
        printf("Total allocated sectors %d greater than the maximum "
            "%d\n", total, heads * sectors * cylinders);
    else {
        total = heads * sectors * cylinders - total;
        if (total != 0)
            printf("%d unallocated sectors\n", total);
    }
}

static void
add_partition(int n, int sys)
{
    char mesg[256];         /* 48 does not suffice in Japanese */
    int i, num_read = 0;
    struct partition *p = ptes[n].part_table;
    struct partition *q = ptes[ext_index].part_table;
    ullong limit, temp;
    ullong start, stop = 0;
    ullong first[partitions], last[partitions];

    if (p && p->sys_ind) {
        printf(msg_part_already_defined, n + 1);
        return;
    }
    fill_bounds(first, last);
    if (n < 4) {
        start = sector_offset;
        if (display_in_cyl_units || !total_number_of_sectors)
            limit = (ullong) heads * sectors * cylinders - 1;
        else
            limit = total_number_of_sectors - 1;
        if (extended_offset) {
            first[ext_index] = extended_offset;
            last[ext_index] = get_start_sect(q) +
                get_nr_sects(q) - 1;
        }
    } else {
        start = extended_offset + sector_offset;
        limit = get_start_sect(q) + get_nr_sects(q) - 1;
    }
    if (display_in_cyl_units)
        for (i = 0; i < partitions; i++)
            first[i] = (cround(first[i]) - 1) * units_per_sector;

    snprintf(mesg, sizeof(mesg), "First %s", str_units(SINGULAR));
    do {
        temp = start;
        for (i = 0; i < partitions; i++) {
            int lastplusoff;

            if (start == ptes[i].offset)
                start += sector_offset;
            lastplusoff = last[i] + ((n < 4) ? 0 : sector_offset);
            if (start >= first[i] && start <= lastplusoff)
                start = lastplusoff + 1;
        }
        if (start > limit)
            break;
        if (start >= temp+units_per_sector && num_read) {
            printf("Sector %lld is already allocated\n", temp);
            temp = start;
            num_read = 0;
        }
        if (!num_read && start == temp) {
            ullong saved_start;

            saved_start = start;
            start = read_int(cround(saved_start), cround(saved_start), cround(limit),
                     0, mesg);
            if (display_in_cyl_units) {
                start = (start - 1) * units_per_sector;
                if (start < saved_start) start = saved_start;
            }
            num_read = 1;
        }
    } while (start != temp || !num_read);
    if (n > 4) {                    /* NOT for fifth partition */
        struct pte *pe = &ptes[n];

        pe->offset = start - sector_offset;
        if (pe->offset == extended_offset) { /* must be corrected */
            pe->offset++;
            if (sector_offset == 1)
                start++;
        }
    }

    for (i = 0; i < partitions; i++) {
        struct pte *pe = &ptes[i];

        if (start < pe->offset && limit >= pe->offset)
            limit = pe->offset - 1;
        if (start < first[i] && limit >= first[i])
            limit = first[i] - 1;
    }
    if (start > limit) {
        printf("No free sectors available\n");
        if (n > 4)
            partitions--;
        return;
    }
    if (cround(start) == cround(limit)) {
        stop = limit;
    } else {
        snprintf(mesg, sizeof(mesg),
             "Last %s or +size or +sizeM or +sizeK",
             str_units(SINGULAR));
        stop = read_int(cround(start), cround(limit), cround(limit),
                cround(start), mesg);
        if (display_in_cyl_units) {
            stop = stop * units_per_sector - 1;
            if (stop >limit)
                stop = limit;
        }
    }

    set_partition(n, 0, start, stop, sys);
    if (n > 4)
        set_partition(n - 1, 1, ptes[n].offset, stop, EXTENDED);

    if (IS_EXTENDED(sys)) {
        struct pte *pe4 = &ptes[4];
        struct pte *pen = &ptes[n];

        ext_index = n;
        pen->ext_pointer = p;
        pe4->offset = extended_offset = start;
        pe4->sectorbuffer = xzalloc(sector_size);
        pe4->part_table = pt_offset(pe4->sectorbuffer, 0);
        pe4->ext_pointer = pe4->part_table + 1;
        pe4->changed = 1;
        partitions = 5;
    }
}

static void
add_logical(void)
{
    if (partitions > 5 || ptes[4].part_table->sys_ind) {
        struct pte *pe = &ptes[partitions];

        pe->sectorbuffer = xzalloc(sector_size);
        pe->part_table = pt_offset(pe->sectorbuffer, 0);
        pe->ext_pointer = pe->part_table + 1;
        pe->offset = 0;
        pe->changed = 1;
        partitions++;
    }
    add_partition(partitions - 1, LINUX_NATIVE);
}

static void
new_partition(void)
{
    int i, free_primary = 0;

    if (warn_geometry())
        return;

    if (LABEL_IS_SUN) {
        add_sun_partition(get_partition(0, partitions), LINUX_NATIVE);
        return;
    }
    if (LABEL_IS_SGI) {
        sgi_add_partition(get_partition(0, partitions), LINUX_NATIVE);
        return;
    }
    if (LABEL_IS_AIX) {
        printf("Sorry - this fdisk cannot handle AIX disk labels.\n"
"If you want to add DOS-type partitions, create a new empty DOS partition\n"
"table first (use 'o'). This will destroy the present disk contents.\n");
        return;
    }

    for (i = 0; i < 4; i++)
        free_primary += !ptes[i].part_table->sys_ind;

    if (!free_primary && partitions >= MAXIMUM_PARTS) {
        printf("The maximum number of partitions has been created\n");
        return;
    }

    if (!free_primary) {
        if (extended_offset)
            add_logical();
        else
            printf("You must delete some partition and add "
                 "an extended partition first\n");
    } else {
        char c, line[80];
        snprintf(line, sizeof(line),
            "Command action\n"
            "   %s\n"
            "   p   primary partition (1-4)\n",
            (extended_offset ?
            "l   logical (5 or over)" : "e   extended"));
        while (1) {
            c = read_nonempty(line);
            if (c == 'p' || c == 'P') {
                i = get_nonexisting_partition(0, 4);
                if (i >= 0)
                    add_partition(i, LINUX_NATIVE);
                return;
            }
            if (c == 'l' && extended_offset) {
                add_logical();
                return;
            }
            if (c == 'e' && !extended_offset) {
                i = get_nonexisting_partition(0, 4);
                if (i >= 0)
                    add_partition(i, EXTENDED);
                return;
            }
            printf("Invalid partition number "
                     "for type '%c'\n", c);
        }
    }
}

static void
write_table(void)
{
    int i;

    if (LABEL_IS_DOS) {
        for (i = 0; i < 3; i++)
            if (ptes[i].changed)
                ptes[3].changed = 1;
        for (i = 3; i < partitions; i++) {
            struct pte *pe = &ptes[i];

            if (pe->changed) {
                write_part_table_flag(pe->sectorbuffer);
                write_sector(pe->offset, pe->sectorbuffer);
            }
        }
    }
    else if (LABEL_IS_SGI) {
        /* no test on change? the printf below might be mistaken */
        sgi_write_table();
    }
    else if (LABEL_IS_SUN) {
        int needw = 0;

        for (i = 0; i < 8; i++)
            if (ptes[i].changed)
                needw = 1;
        if (needw)
            sun_write_table();
    }

    printf("The partition table has been altered!\n\n");
    reread_partition_table(1);
}

static void
reread_partition_table(int leave)
{
    int i;

    printf("Calling ioctl() to re-read partition table\n");
    sync();
    /* sleep(2); Huh? */
    i = ioctl_or_perror(fd, BLKRRPART, NULL,
            "WARNING: rereading partition table "
            "failed, kernel still uses old table");
#if 0
    if (dos_changed)
        printf(
        "\nWARNING: If you have created or modified any DOS 6.x\n"
        "partitions, please see the fdisk manual page for additional\n"
        "information\n");
#endif

    if (leave) {
        if (ENABLE_FEATURE_CLEAN_UP)
            close(fd);
        exit(i != 0);
    }
}
#endif /* FEATURE_FDISK_WRITABLE */

#if ENABLE_FEATURE_FDISK_ADVANCED
#define MAX_PER_LINE    16
static void
print_buffer(char *pbuffer)
{
    int i,l;

    for (i = 0, l = 0; i < sector_size; i++, l++) {
        if (l == 0)
            printf("0x%03X:", i);
        printf(" %02X", (unsigned char) pbuffer[i]);
        if (l == MAX_PER_LINE - 1) {
            puts("");
            l = -1;
        }
    }
    if (l > 0)
        puts("");
    puts("");
}

static void
print_raw(void)
{
    int i;

    printf("Device: %s\n", disk_device);
    if (LABEL_IS_SGI || LABEL_IS_SUN)
        print_buffer(MBRbuffer);
    else {
        for (i = 3; i < partitions; i++)
            print_buffer(ptes[i].sectorbuffer);
    }
}

static void
move_begin(int i)
{
    struct pte *pe = &ptes[i];
    struct partition *p = pe->part_table;
    ullong new, first;

    if (warn_geometry())
        return;
    if (!p->sys_ind || !get_nr_sects(p) || IS_EXTENDED(p->sys_ind)) {
        printf("Partition %d has no data area\n", i + 1);
        return;
    }
    first = get_partition_start(pe);
    new = read_int(first, first, first + get_nr_sects(p) - 1, first,
               "New beginning of data") - pe->offset;

    if (new != get_nr_sects(p)) {
        first = get_nr_sects(p) + get_start_sect(p) - new;
        set_nr_sects(p, first);
        set_start_sect(p, new);
        pe->changed = 1;
    }
}

static void
xselect(void)
{
    char c;

    while (1) {
        putchar('\n');
        c = tolower(read_nonempty("Expert command (m for help): "));
        switch (c) {
        case 'a':
            if (LABEL_IS_SUN)
                sun_set_alt_cyl();
            break;
        case 'b':
            if (LABEL_IS_DOS)
                move_begin(get_partition(0, partitions));
            break;
        case 'c':
            user_cylinders = cylinders =
                read_int(1, cylinders, 1048576, 0,
                    "Number of cylinders");
            if (LABEL_IS_SUN)
                sun_set_ncyl(cylinders);
            if (LABEL_IS_DOS)
                warn_cylinders();
            break;
        case 'd':
            print_raw();
            break;
        case 'e':
            if (LABEL_IS_SGI)
                sgi_set_xcyl();
            else if (LABEL_IS_SUN)
                sun_set_xcyl();
            else if (LABEL_IS_DOS)
                x_list_table(1);
            break;
        case 'f':
            if (LABEL_IS_DOS)
                fix_partition_table_order();
            break;
        case 'g':
#if ENABLE_FEATURE_SGI_LABEL
            create_sgilabel();
#endif
            break;
        case 'h':
            user_heads = heads = read_int(1, heads, 256, 0,
                    "Number of heads");
            update_units();
            break;
        case 'i':
            if (LABEL_IS_SUN)
                sun_set_ilfact();
            break;
        case 'o':
            if (LABEL_IS_SUN)
                sun_set_rspeed();
            break;
        case 'p':
            if (LABEL_IS_SUN)
                list_table(1);
            else
                x_list_table(0);
            break;
        case 'q':
            close(fd);
            puts("");
            exit(0);
        case 'r':
            return;
        case 's':
            user_sectors = sectors = read_int(1, sectors, 63, 0,
                       "Number of sectors");
            if (dos_compatible_flag) {
                sector_offset = sectors;
                printf("Warning: setting sector offset for DOS "
                    "compatiblity\n");
            }
            update_units();
            break;
        case 'v':
            verify();
            break;
        case 'w':
            write_table();  /* does not return */
            break;
        case 'y':
            if (LABEL_IS_SUN)
                sun_set_pcylcount();
            break;
        default:
            xmenu();
        }
    }
}
#endif /* ADVANCED mode */

static int
is_ide_cdrom_or_tape(const char *device)
{
    FILE *procf;
    char buf[100];
    struct stat statbuf;
    int is_ide = 0;

    /* No device was given explicitly, and we are trying some
       likely things.  But opening /dev/hdc may produce errors like
       "hdc: tray open or drive not ready"
       if it happens to be a CD-ROM drive. It even happens that
       the process hangs on the attempt to read a music CD.
       So try to be careful. This only works since 2.1.73. */

    if (strncmp("/dev/hd", device, 7))
        return 0;

    snprintf(buf, sizeof(buf), "/proc/ide/%s/media", device+5);
    procf = fopen(buf, "r");
    if (procf != NULL && fgets(buf, sizeof(buf), procf))
        is_ide = (!strncmp(buf, "cdrom", 5) ||
              !strncmp(buf, "tape", 4));
    else
        /* Now when this proc file does not exist, skip the
           device when it is read-only. */
        if (stat(device, &statbuf) == 0)
            is_ide = ((statbuf.st_mode & 0222) == 0);

    if (procf)
        fclose(procf);
    return is_ide;
}


static void
trydev(const char *device, int user_specified)
{
    int gb;

    disk_device = device;
    if (setjmp(listingbuf))
        return;
    if (!user_specified)
        if (is_ide_cdrom_or_tape(device))
            return;
    fd = open(disk_device, type_open);
    if (fd >= 0) {
        gb = get_boot(try_only);
        if (gb > 0) {   /* I/O error */
            close(fd);
        } else if (gb < 0) { /* no DOS signature */
            list_disk_geometry();
            if (LABEL_IS_AIX) {
                return;
            }
#if ENABLE_FEATURE_OSF_LABEL
            if (bsd_trydev(device) < 0)
#endif
                printf("Disk %s doesn't contain a valid "
                    "partition table\n", device);
            close(fd);
        } else {
            close(fd);
            list_table(0);
#if ENABLE_FEATURE_FDISK_WRITABLE
            if (!LABEL_IS_SUN && partitions > 4){
                delete_partition(ext_index);
            }
#endif
        }
    } else {
        /* Ignore other errors, since we try IDE
           and SCSI hard disks which may not be
           installed on the system. */
        if (errno == EACCES) {
            printf("Cannot open %s\n", device);
            return;
        }
    }
}

/* for fdisk -l: try all things in /proc/partitions
   that look like a partition name (do not end in a digit) */
static void
tryprocpt(void)
{
    FILE *procpt;
    char line[100], ptname[100], devname[120], *s;
    int ma, mi, sz;

    procpt = fopen_or_warn("/proc/partitions", "r");

    while (fgets(line, sizeof(line), procpt)) {
        if (sscanf(line, " %d %d %d %[^\n ]",
                &ma, &mi, &sz, ptname) != 4)
            continue;
        for (s = ptname; *s; s++);
        if (isdigit(s[-1]))
            continue;
        sprintf(devname, "/dev/%s", ptname);
        trydev(devname, 0);
    }
#if ENABLE_FEATURE_CLEAN_UP
    fclose(procpt);
#endif
}

#if ENABLE_FEATURE_FDISK_WRITABLE
static void
unknown_command(int c)
{
    printf("%c: unknown command\n", c);
}
#endif

int fdisk_main(int argc, char **argv);
int fdisk_main(int argc, char **argv)
{
    char *str_b, *str_C, *str_H, *str_S;
    unsigned opt;
    /*
     *  fdisk -v
     *  fdisk -l [-b sectorsize] [-u] device ...
     *  fdisk -s [partition] ...
     *  fdisk [-b sectorsize] [-u] device
     *
     * Options -C, -H, -S set the geometry.
     */
    enum {
        OPT_b = 1 << 0,
        OPT_C = 1 << 1,
        OPT_H = 1 << 2,
        OPT_l = 1 << 3,
        OPT_S = 1 << 4,
        OPT_u = 1 << 5,
        OPT_s = (1 << 6) * ENABLE_FEATURE_FDISK_BLKSIZE,
    };

    PTR_TO_GLOBALS = xzalloc(sizeof(G));

    opt = getopt32(argv, "b:C:H:lS:u" USE_FEATURE_FDISK_BLKSIZE("s"),
                &str_b, &str_C, &str_H, &str_S);
    argc -= optind;
    argv += optind;
    if (opt & OPT_b) { // -b
        /* Ugly: this sector size is really per device,
           so cannot be combined with multiple disks,
           and the same goes for the C/H/S options.
        */
        sector_size = xatoi_u(str_b);
        if (sector_size != 512 && sector_size != 1024 &&
            sector_size != 2048)
            bb_show_usage();
        sector_offset = 2;
        user_set_sector_size = 1;
    }
    if (opt & OPT_C) user_cylinders = xatoi_u(str_C); // -C
    if (opt & OPT_H) { // -H
        user_heads = xatoi_u(str_H);
        if (user_heads <= 0 || user_heads >= 256)
            user_heads = 0;
    }
    //if (opt & OPT_l) // -l
    if (opt & OPT_S) { // -S
        user_sectors = xatoi_u(str_S);
        if (user_sectors <= 0 || user_sectors >= 64)
            user_sectors = 0;
    }
    if (opt & OPT_u) display_in_cyl_units = 0; // -u
    //if (opt & OPT_s) // -s

    if (user_set_sector_size && argc != 1)
        printf("Warning: the -b (set sector size) option should"
             " be used with one specified device\n");

#if ENABLE_FEATURE_FDISK_WRITABLE
    if (opt & OPT_l) {
        nowarn = 1;
#endif
        type_open = O_RDONLY;
        if (argc > 0) {
            int k;
#if defined(__GNUC__)
            /* avoid gcc warning:
               variable `k' might be clobbered by `longjmp' */
            (void)&k;
#endif
            listing = 1;
            for (k = 0; k < argc; k++)
                trydev(argv[k], 1);
        } else {
            /* we no longer have default device names */
            /* but, we can use /proc/partitions instead */
            tryprocpt();
        }
        return 0;
#if ENABLE_FEATURE_FDISK_WRITABLE
    }
#endif

#if ENABLE_FEATURE_FDISK_BLKSIZE
    if (opt & OPT_s) {
        long size;
        int j;

        nowarn = 1;
        type_open = O_RDONLY;

        if (argc <= 0)
            bb_show_usage();

        for (j = 0; j < argc; j++) {
            disk_device = argv[j];
            fd = open(disk_device, type_open);
            if (fd < 0)
                fdisk_fatal(unable_to_open);
            if (ioctl(fd, BLKGETSIZE, &size))
                fdisk_fatal(ioctl_error);
            close(fd);
            if (argc == 1)
                printf("%ld\n", size/2);
            else
                printf("%s: %ld\n", argv[j], size/2);
        }
        return 0;
    }
#endif

#if ENABLE_FEATURE_FDISK_WRITABLE
    if (argc != 1)
        bb_show_usage();

    disk_device = argv[0];
    get_boot(fdisk);

    if (LABEL_IS_OSF) {
        /* OSF label, and no DOS label */
        printf("Detected an OSF/1 disklabel on %s, entering "
            "disklabel mode\n", disk_device);
        bsd_select();
        /*Why do we do this?  It seems to be counter-intuitive*/
        current_label_type = label_dos;
        /* If we return we may want to make an empty DOS label? */
    }

    while (1) {
        int c;
        putchar('\n');
        c = tolower(read_nonempty("Command (m for help): "));
        switch (c) {
        case 'a':
            if (LABEL_IS_DOS)
                toggle_active(get_partition(1, partitions));
            else if (LABEL_IS_SUN)
                toggle_sunflags(get_partition(1, partitions),
                        0x01);
            else if (LABEL_IS_SGI)
                sgi_set_bootpartition(
                    get_partition(1, partitions));
            else
                unknown_command(c);
            break;
        case 'b':
            if (LABEL_IS_SGI) {
                printf("\nThe current boot file is: %s\n",
                    sgi_get_bootfile());
                if (read_maybe_empty("Please enter the name of the "
                           "new boot file: ") == '\n')
                    printf("Boot file unchanged\n");
                else
                    sgi_set_bootfile(line_ptr);
            }
#if ENABLE_FEATURE_OSF_LABEL
            else
                bsd_select();
#endif
            break;
        case 'c':
            if (LABEL_IS_DOS)
                toggle_dos_compatibility_flag();
            else if (LABEL_IS_SUN)
                toggle_sunflags(get_partition(1, partitions),
                        0x10);
            else if (LABEL_IS_SGI)
                sgi_set_swappartition(
                        get_partition(1, partitions));
            else
                unknown_command(c);
            break;
        case 'd':
            {
                int j;
            /* If sgi_label then don't use get_existing_partition,
               let the user select a partition, since
               get_existing_partition() only works for Linux-like
               partition tables */
                if (!LABEL_IS_SGI) {
                    j = get_existing_partition(1, partitions);
                } else {
                    j = get_partition(1, partitions);
                }
                if (j >= 0)
                    delete_partition(j);
            }
            break;
        case 'i':
            if (LABEL_IS_SGI)
                create_sgiinfo();
            else
                unknown_command(c);
        case 'l':
            list_types(get_sys_types());
            break;
        case 'm':
            menu();
            break;
        case 'n':
            new_partition();
            break;
        case 'o':
            create_doslabel();
            break;
        case 'p':
            list_table(0);
            break;
        case 'q':
            close(fd);
            puts("");
            return 0;
        case 's':
#if ENABLE_FEATURE_SUN_LABEL
            create_sunlabel();
#endif
            break;
        case 't':
            change_sysid();
            break;
        case 'u':
            change_units();
            break;
        case 'v':
            verify();
            break;
        case 'w':
            write_table();          /* does not return */
            break;
#if ENABLE_FEATURE_FDISK_ADVANCED
        case 'x':
            if (LABEL_IS_SGI) {
                printf("\n\tSorry, no experts menu for SGI "
                    "partition tables available\n\n");
            } else
                xselect();
            break;
#endif
        default:
            unknown_command(c);
            menu();
        }
    }
    return 0;
#endif /* FEATURE_FDISK_WRITABLE */
}