Initial public busybox upstream commit

[busybox4maemo] / util-linux / fdisk.c

/* 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";


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 void update_units(void);
#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);
#if ENABLE_FEATURE_SUN_LABEL || ENABLE_FEATURE_FDISK_WRITABLE
static int get_boot(enum action what);
#else
static int get_boot(void);
#endif

#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;

        const char *disk_device;
        int fd;                         /* the disk */
        int g_partitions; // = 4;       /* maximum partition + 1 */
        unsigned units_per_sector; // = 1;
        unsigned sector_size; // = DEFAULT_SECTOR_SIZE;
        unsigned user_set_sector_size;
        unsigned sector_offset; // = 1;
        unsigned g_heads, g_sectors, g_cylinders;
        enum label_type current_label_type;
        smallint display_in_cyl_units; // = 1;
#if ENABLE_FEATURE_OSF_LABEL
        smallint possibly_osf_label;
#endif

        jmp_buf listingbuf;
        char line_buffer[80];
        char partname_buffer[80];
        /* 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];
};
#define G (*ptr_to_globals)
#define line_ptr        (G.line_ptr)
#define disk_device          (G.disk_device         )
#define fd                   (G.fd                  )
#define g_partitions         (G.g_partitions        )
#define units_per_sector     (G.units_per_sector    )
#define sector_size          (G.sector_size         )
#define user_set_sector_size (G.user_set_sector_size)
#define sector_offset        (G.sector_offset       )
#define g_heads              (G.g_heads             )
#define g_sectors            (G.g_sectors           )
#define g_cylinders          (G.g_cylinders         )
#define current_label_type   (G.current_label_type  )
#define display_in_cyl_units (G.display_in_cyl_units)
#define possibly_osf_label   (G.possibly_osf_label  )
#define listingbuf      (G.listingbuf)
#define line_buffer     (G.line_buffer)
#define partname_buffer (G.partname_buffer)
#define MBRbuffer       (G.MBRbuffer)
#define ptes            (G.ptes)
#define INIT_G() do { \
        SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
        sector_size = DEFAULT_SECTOR_SIZE; \
        sector_offset = 1; \
        g_partitions = 4; \
        display_in_cyl_units = 1; \
        units_per_sector = 1; \
} while (0)


/* TODO: move to libbb? */
static ullong bb_BLKGETSIZE_sectors(void)
{
        uint64_t v64;
        unsigned long longsectors;

        if (ioctl(fd, BLKGETSIZE64, &v64) == 0) {
                /* got bytes, convert to 512 byte sectors */
                return (v64 >> 9);
        }
        /* Needs temp of type long */
        if (ioctl(fd, BLKGETSIZE, &longsectors))
                longsectors = 0;
        return longsectors;
}


#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 % g_sectors + 1;  \
                sector /= g_sectors;         \
                h = sector % g_heads;        \
                sector /= g_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 smallint listing;                /* no aborts for fdisk -l */
static smallint dos_compatible_flag = 1;
#if ENABLE_FEATURE_FDISK_WRITABLE
//static int dos_changed;
static smallint 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".
 */
#ifdef UNUSED
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);
}
#endif

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]);
        bb_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 / (g_sectors * g_heads) > 1023))
                start = g_heads * g_sectors * 1024 - 1;
        set_hsc(p->head, p->sector, p->cyl, start);
        if (dos_compatible_flag && (stop / (g_sectors * g_heads) > 1023))
                stop = g_heads * g_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 (g_heads && g_sectors && g_cylinders)
                return 0;

        printf("Unknown value(s) for:");
        if (!g_heads)
                printf(" heads");
        if (!g_sectors)
                printf(" sectors");
        if (!g_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 = g_heads * g_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 && g_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",
                        g_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[g_partitions];

                if (g_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[g_partitions - 1];
#if ENABLE_FEATURE_FDISK_WRITABLE
                        printf("Warning: deleting partitions after %d\n",
                                g_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", g_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", g_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;
                g_partitions++;
        }

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

                if (!get_nr_sects(pe->part_table)
                 && (g_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
        g_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;

        get_sectorsize();
        sec_fac = sector_size / 512;
#if ENABLE_FEATURE_SUN_LABEL
        guess_device_type();
#endif
        g_heads = g_cylinders = g_sectors = 0;
        kern_heads = kern_sectors = 0;
        pt_heads = pt_sectors = 0;

        get_kernel_geometry();
        get_partition_table_geometry();

        g_heads = user_heads ? user_heads :
                pt_heads ? pt_heads :
                kern_heads ? kern_heads : 255;
        g_sectors = user_sectors ? user_sectors :
                pt_sectors ? pt_sectors :
                kern_sectors ? kern_sectors : 63;
        total_number_of_sectors = bb_BLKGETSIZE_sectors();

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

        g_cylinders = total_number_of_sectors / (g_heads * g_sectors * sec_fac);
        if (!g_cylinders)
                g_cylinders = user_cylinders;
}

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

        g_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 (g_partitions != 4)
                                printf("Ignoring extra extended "
                                        "partition %d\n", i + 1);
                        else
                                read_extended(i);
                }
        }

        for (i = 3; i < g_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 *= g_heads * g_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 = 1 - dos_compatible_flag;
        if (dos_compatible_flag) {
                sector_offset = g_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) {
                        g_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 */
                --g_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 (g_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 (g_partitions > 5) {
                        g_partitions--;
                        while (i < g_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, g_partitions);
        } else {
                i = get_partition(0, g_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 = g_heads * g_sectors;

        *c = ls / spc;
        ls = ls % spc;
        *h = ls / g_sectors;
        *s = ls % g_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 (!g_heads || !g_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 (g_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 (g_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 != (g_heads - 1) || pes != g_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",
                   g_heads, g_sectors, g_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 < g_partitions; i++) {
                if (i == 4) {
                        last_i = 4;
                        last_p_start_pos = 0;
                }
                pe = &ptes[i];
                p = pe->part_table;
                if (p->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 < g_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 < g_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 < g_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 < g_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, g_heads, g_sectors, g_cylinders);
        printf("Nr AF  Hd Sec  Cyl  Hd Sec  Cyl      Start       Size ID\n");
        for (i = 0; i < g_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 < g_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 * g_sectors + real_s) * g_heads + h;
        if (!total)
                printf("Partition %d contains sector 0\n", n);
        if (h >= g_heads)
                printf("Partition %d: head %d greater than maximum %d\n",
                        n, h + 1, g_heads);
        if (real_s >= g_sectors)
                printf("Partition %d: sector %d greater than "
                        "maximum %d\n", n, s, g_sectors);
        if (real_c >= g_cylinders)
                printf("Partition %d: cylinder %llu greater than "
                        "maximum %d\n", n, real_c + 1, g_cylinders);
        if (g_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[g_partitions], last[g_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 < g_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 < g_partitions; i++) {
                        total++;
                        p = ptes[i].part_table;
                        if (!p->sys_ind) {
                                if (i != 4 || i + 1 < g_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 > g_heads * g_sectors * g_cylinders)
                printf("Total allocated sectors %d greater than the maximum "
                        "%d\n", total, g_heads * g_sectors * g_cylinders);
        else {
                total = g_heads * g_sectors * g_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[g_partitions], last[g_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) g_heads * g_sectors * g_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 < g_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 < g_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 < g_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)
                        g_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;
                g_partitions = 5;
        }
}

static void
add_logical(void)
{
        if (g_partitions > 5 || ptes[4].part_table->sys_ind) {
                struct pte *pe = &ptes[g_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;
                g_partitions++;
        }
        add_partition(g_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, g_partitions), LINUX_NATIVE);
                return;
        }
        if (LABEL_IS_SGI) {
                sgi_add_partition(get_partition(0, g_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 && g_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 < g_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) {
                        bb_putchar('\n');
                        l = -1;
                }
        }
        if (l > 0)
                bb_putchar('\n');
        bb_putchar('\n');
}

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 < g_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) {
                bb_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, g_partitions));
                        break;
                case 'c':
                        user_cylinders = g_cylinders =
                                read_int(1, g_cylinders, 1048576, 0,
                                        "Number of cylinders");
                        if (LABEL_IS_SUN)
                                sun_set_ncyl(g_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 = g_heads = read_int(1, g_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);
                        bb_putchar('\n');
                        exit(0);
                case 'r':
                        return;
                case 's':
                        user_sectors = g_sectors = read_int(1, g_sectors, 63, 0,
                                           "Number of sectors");
                        if (dos_compatible_flag) {
                                sector_offset = g_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 && g_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++)
                        continue;
                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) MAIN_EXTERNALLY_VISIBLE;
int fdisk_main(int argc, char **argv)
{
        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,
        };

        INIT_G();

        opt_complementary = "b+:C+:H+:S+"; /* numeric params */
        opt = getopt32(argv, "b:C:H:lS:u" USE_FEATURE_FDISK_BLKSIZE("s"),
                                &sector_size, &user_cylinders, &user_heads, &user_sectors);
        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.
                */
                if (sector_size != 512 && sector_size != 1024
                 && sector_size != 2048)
                        bb_show_usage();
                sector_offset = 2;
                user_set_sector_size = 1;
        }
        if (user_heads <= 0 || user_heads >= 256)
                user_heads = 0;
        if (user_sectors <= 0 || user_sectors >= 64)
                user_sectors = 0;
        if (opt & OPT_u)
                display_in_cyl_units = 0; // -u

#if ENABLE_FEATURE_FDISK_WRITABLE
        if (opt & OPT_l) {
                nowarn = 1;
#endif
                type_open = O_RDONLY;
                if (*argv) {
                        listing = 1;
                        do {
                                trydev(*argv, 1);
                        } while (*++argv);
                } else {
                        /* we don't have device names, */
                        /* use /proc/partitions instead */
                        tryprocpt();
                }
                return 0;
#if ENABLE_FEATURE_FDISK_WRITABLE
        }
#endif

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

                nowarn = 1;
                if (argc <= 0)
                        bb_show_usage();
                for (j = 0; j < argc; j++) {
                        unsigned long long size;
                        fd = xopen(argv[j], O_RDONLY);
                        size = bb_BLKGETSIZE_sectors() / 2;
                        close(fd);
                        if (argc == 1)
                                printf("%lld\n", size);
                        else
                                printf("%s: %lld\n", argv[j], size);
                }
                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;
                bb_putchar('\n');
                c = tolower(read_nonempty("Command (m for help): "));
                switch (c) {
                case 'a':
                        if (LABEL_IS_DOS)
                                toggle_active(get_partition(1, g_partitions));
                        else if (LABEL_IS_SUN)
                                toggle_sunflags(get_partition(1, g_partitions),
                                                0x01);
                        else if (LABEL_IS_SGI)
                                sgi_set_bootpartition(
                                        get_partition(1, g_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, g_partitions),
                                                0x10);
                        else if (LABEL_IS_SGI)
                                sgi_set_swappartition(
                                                get_partition(1, g_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, g_partitions);
                                } else {
                                        j = get_partition(1, g_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);
                        bb_putchar('\n');
                        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 */
}