source: MondoRescue/branches/3.2/mindi-busybox/util-linux/mkfs_minix.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * mkfs.c - make a linux (minix) file-system.
 *
 * (C) 1991 Linus Torvalds.
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */

/*
 * DD.MM.YY
 *
 * 24.11.91  -  Time began. Used the fsck sources to get started.
 *
 * 25.11.91  -  Corrected some bugs. Added support for ".badblocks"
 *      The algorithm for ".badblocks" is a bit weird, but
 *      it should work. Oh, well.
 *
 * 25.01.92  -  Added the -l option for getting the list of bad blocks
 *      out of a named file. (Dave Rivers, rivers@ponds.uucp)
 *
 * 28.02.92  -  Added %-information when using -c.
 *
 * 28.02.93  -  Added support for other namelengths than the original
 *      14 characters so that I can test the new kernel routines..
 *
 * 09.10.93  -  Make exit status conform to that required by fsutil
 *      (Rik Faith, faith@cs.unc.edu)
 *
 * 31.10.93  -  Added inode request feature, for backup floppies: use
 *      32 inodes, for a news partition use more.
 *      (Scott Heavner, sdh@po.cwru.edu)
 *
 * 03.01.94  -  Added support for file system valid flag.
 *      (Dr. Wettstein, greg%wind.uucp@plains.nodak.edu)
 *
 * 30.10.94  -  added support for v2 filesystem
 *          (Andreas Schwab, schwab@issan.informatik.uni-dortmund.de)
 *
 * 09.11.94  -  Added test to prevent overwrite of mounted fs adapted
 *      from Theodore Ts'o's (tytso@athena.mit.edu) mke2fs
 *      program.  (Daniel Quinlan, quinlan@yggdrasil.com)
 *
 * 03.20.95  -  Clear first 512 bytes of filesystem to make certain that
 *      the filesystem is not misidentified as a MS-DOS FAT filesystem.
 *      (Daniel Quinlan, quinlan@yggdrasil.com)
 *
 * 02.07.96  -  Added small patch from Russell King to make the program a
 *      good deal more portable (janl@math.uio.no)
 *
 * Usage:  mkfs [-c | -l filename ] [-v] [-nXX] [-iXX] device [size-in-blocks]
 *
 *  -c for readability checking (SLOW!)
 *      -l for getting a list of bad blocks from a file.
 *  -n for namelength (currently the kernel only uses 14 or 30)
 *  -i for number of inodes
 *  -v for v2 filesystem
 *
 * The device may be a block device or a image of one, but this isn't
 * enforced (but it's not much fun on a character device :-).
 *
 * Modified for BusyBox by Erik Andersen <andersen@debian.org> --
 *  removed getopt based parser and added a hand rolled one.
 */

//usage:#define mkfs_minix_trivial_usage
//usage:       "[-c | -l FILE] [-nXX] [-iXX] BLOCKDEV [KBYTES]"
//usage:#define mkfs_minix_full_usage "\n\n"
//usage:       "Make a MINIX filesystem\n"
//usage:     "\n    -c      Check device for bad blocks"
//usage:     "\n    -n [14|30]  Maximum length of filenames"
//usage:     "\n    -i INODES   Number of inodes for the filesystem"
//usage:     "\n    -l FILE     Read bad blocks list from FILE"
//usage:     "\n    -v      Make version 2 filesystem"

#include "libbb.h"
#include <mntent.h>

#include "minix.h"

/* Store the very same times/uids/gids for image consistency */
#if 1
# define CUR_TIME 0
# define GETUID 0
# define GETGID 0
#else
/* Was using this. Is it useful? NB: this will break testsuite */
# define CUR_TIME time(NULL)
# define GETUID getuid()
# define GETGID getgid()
#endif

enum {
    MAX_GOOD_BLOCKS         = 512,
    TEST_BUFFER_BLOCKS      = 16,
};

#if !ENABLE_FEATURE_MINIX2
enum { version2 = 0 };
#endif

enum { dev_fd = 3 };

struct globals {
#if ENABLE_FEATURE_MINIX2
    smallint version2;
#define version2 G.version2
#endif
    char *device_name;
    uint32_t total_blocks;
    int badblocks;
    int namelen;
    int dirsize;
    int magic;
    char *inode_buffer;
    char *inode_map;
    char *zone_map;
    int used_good_blocks;
    unsigned long req_nr_inodes;
    unsigned currently_testing;

    char root_block[BLOCK_SIZE];
    char superblock_buffer[BLOCK_SIZE];
    char boot_block_buffer[512];
    unsigned short good_blocks_table[MAX_GOOD_BLOCKS];
    /* check_blocks(): buffer[] was the biggest static in entire bbox */
    char check_blocks_buffer[BLOCK_SIZE * TEST_BUFFER_BLOCKS];

    unsigned short ind_block1[BLOCK_SIZE >> 1];
    unsigned short dind_block1[BLOCK_SIZE >> 1];
    unsigned long ind_block2[BLOCK_SIZE >> 2];
    unsigned long dind_block2[BLOCK_SIZE >> 2];
};
#define G (*ptr_to_globals)
#define INIT_G() do { \
    SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)

static ALWAYS_INLINE unsigned div_roundup(unsigned size, unsigned n)
{
    return (size + n-1) / n;
}

#define INODE_BUF1              (((struct minix1_inode*)G.inode_buffer) - 1)
#define INODE_BUF2              (((struct minix2_inode*)G.inode_buffer) - 1)

#define SB                      (*(struct minix_superblock*)G.superblock_buffer)

#define SB_INODES               (SB.s_ninodes)
#define SB_IMAPS                (SB.s_imap_blocks)
#define SB_ZMAPS                (SB.s_zmap_blocks)
#define SB_FIRSTZONE            (SB.s_firstdatazone)
#define SB_ZONE_SIZE            (SB.s_log_zone_size)
#define SB_MAXSIZE              (SB.s_max_size)
#define SB_MAGIC                (SB.s_magic)

#if !ENABLE_FEATURE_MINIX2
# define SB_ZONES               (SB.s_nzones)
# define INODE_BLOCKS           div_roundup(SB_INODES, MINIX1_INODES_PER_BLOCK)
#else
# define SB_ZONES               (version2 ? SB.s_zones : SB.s_nzones)
# define INODE_BLOCKS           div_roundup(SB_INODES, \
                                (version2 ? MINIX2_INODES_PER_BLOCK : MINIX1_INODES_PER_BLOCK))
#endif

#define INODE_BUFFER_SIZE       (INODE_BLOCKS * BLOCK_SIZE)
#define NORM_FIRSTZONE          (2 + SB_IMAPS + SB_ZMAPS + INODE_BLOCKS)

/* Before you ask "where they come from?": */
/* setbit/clrbit are supplied by sys/param.h */

static int minix_bit(const char* a, unsigned i)
{
    return a[i >> 3] & (1<<(i & 7));
}

static void minix_setbit(char *a, unsigned i)
{
    setbit(a, i);
}
static void minix_clrbit(char *a, unsigned i)
{
    clrbit(a, i);
}

/* Note: do not assume 0/1, it is 0/nonzero */
#define zone_in_use(x)  minix_bit(G.zone_map,(x)-SB_FIRSTZONE+1)
/*#define inode_in_use(x) minix_bit(G.inode_map,(x))*/

#define mark_inode(x)   minix_setbit(G.inode_map,(x))
#define unmark_inode(x) minix_clrbit(G.inode_map,(x))
#define mark_zone(x)    minix_setbit(G.zone_map,(x)-SB_FIRSTZONE+1)
#define unmark_zone(x)  minix_clrbit(G.zone_map,(x)-SB_FIRSTZONE+1)

#ifndef BLKGETSIZE
# define BLKGETSIZE     _IO(0x12,96)    /* return device size */
#endif


static long valid_offset(int fd, int offset)
{
    char ch;

    if (lseek(fd, offset, SEEK_SET) < 0)
        return 0;
    if (read(fd, &ch, 1) < 1)
        return 0;
    return 1;
}

static int count_blocks(int fd)
{
    int high, low;

    low = 0;
    for (high = 1; valid_offset(fd, high); high *= 2)
        low = high;

    while (low < high - 1) {
        const int mid = (low + high) / 2;

        if (valid_offset(fd, mid))
            low = mid;
        else
            high = mid;
    }
    valid_offset(fd, 0);
    return (low + 1);
}

static int get_size(const char *file)
{
    int fd;
    long size;

    fd = xopen(file, O_RDWR);
    if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
        close(fd);
        return (size * 512);
    }

    size = count_blocks(fd);
    close(fd);
    return size;
}

static void write_tables(void)
{
    /* Mark the superblock valid. */
    SB.s_state |= MINIX_VALID_FS;
    SB.s_state &= ~MINIX_ERROR_FS;

    msg_eol = "seek to 0 failed";
    xlseek(dev_fd, 0, SEEK_SET);

    msg_eol = "can't clear boot sector";
    xwrite(dev_fd, G.boot_block_buffer, 512);

    msg_eol = "seek to BLOCK_SIZE failed";
    xlseek(dev_fd, BLOCK_SIZE, SEEK_SET);

    msg_eol = "can't write superblock";
    xwrite(dev_fd, G.superblock_buffer, BLOCK_SIZE);

    msg_eol = "can't write inode map";
    xwrite(dev_fd, G.inode_map, SB_IMAPS * BLOCK_SIZE);

    msg_eol = "can't write zone map";
    xwrite(dev_fd, G.zone_map, SB_ZMAPS * BLOCK_SIZE);

    msg_eol = "can't write inodes";
    xwrite(dev_fd, G.inode_buffer, INODE_BUFFER_SIZE);

    msg_eol = "\n";
}

static void write_block(int blk, char *buffer)
{
    xlseek(dev_fd, blk * BLOCK_SIZE, SEEK_SET);
    xwrite(dev_fd, buffer, BLOCK_SIZE);
}

static int get_free_block(void)
{
    int blk;

    if (G.used_good_blocks + 1 >= MAX_GOOD_BLOCKS)
        bb_error_msg_and_die("too many bad blocks");
    if (G.used_good_blocks)
        blk = G.good_blocks_table[G.used_good_blocks - 1] + 1;
    else
        blk = SB_FIRSTZONE;
    while (blk < SB_ZONES && zone_in_use(blk))
        blk++;
    if (blk >= SB_ZONES)
        bb_error_msg_and_die("not enough good blocks");
    G.good_blocks_table[G.used_good_blocks] = blk;
    G.used_good_blocks++;
    return blk;
}

static void mark_good_blocks(void)
{
    int blk;

    for (blk = 0; blk < G.used_good_blocks; blk++)
        mark_zone(G.good_blocks_table[blk]);
}

static int next(int zone)
{
    if (!zone)
        zone = SB_FIRSTZONE - 1;
    while (++zone < SB_ZONES)
        if (zone_in_use(zone))
            return zone;
    return 0;
}

static void make_bad_inode(void)
{
    struct minix1_inode *inode = &INODE_BUF1[MINIX_BAD_INO];
    int i, j, zone;
    int ind = 0, dind = 0;
    /* moved to globals to reduce stack usage
    unsigned short ind_block[BLOCK_SIZE >> 1];
    unsigned short dind_block[BLOCK_SIZE >> 1];
    */
#define ind_block (G.ind_block1)
#define dind_block (G.dind_block1)

#define NEXT_BAD (zone = next(zone))

    if (!G.badblocks)
        return;
    mark_inode(MINIX_BAD_INO);
    inode->i_nlinks = 1;
    /* BTW, setting this makes all images different */
    /* it's harder to check for bugs then - diff isn't helpful :(... */
    inode->i_time = CUR_TIME;
    inode->i_mode = S_IFREG + 0000;
    inode->i_size = G.badblocks * BLOCK_SIZE;
    zone = next(0);
    for (i = 0; i < 7; i++) {
        inode->i_zone[i] = zone;
        if (!NEXT_BAD)
            goto end_bad;
    }
    inode->i_zone[7] = ind = get_free_block();
    memset(ind_block, 0, BLOCK_SIZE);
    for (i = 0; i < 512; i++) {
        ind_block[i] = zone;
        if (!NEXT_BAD)
            goto end_bad;
    }
    inode->i_zone[8] = dind = get_free_block();
    memset(dind_block, 0, BLOCK_SIZE);
    for (i = 0; i < 512; i++) {
        write_block(ind, (char *) ind_block);
        dind_block[i] = ind = get_free_block();
        memset(ind_block, 0, BLOCK_SIZE);
        for (j = 0; j < 512; j++) {
            ind_block[j] = zone;
            if (!NEXT_BAD)
                goto end_bad;
        }
    }
    bb_error_msg_and_die("too many bad blocks");
 end_bad:
    if (ind)
        write_block(ind, (char *) ind_block);
    if (dind)
        write_block(dind, (char *) dind_block);
#undef ind_block
#undef dind_block
}

#if ENABLE_FEATURE_MINIX2
static void make_bad_inode2(void)
{
    struct minix2_inode *inode = &INODE_BUF2[MINIX_BAD_INO];
    int i, j, zone;
    int ind = 0, dind = 0;
    /* moved to globals to reduce stack usage
    unsigned long ind_block[BLOCK_SIZE >> 2];
    unsigned long dind_block[BLOCK_SIZE >> 2];
    */
#define ind_block (G.ind_block2)
#define dind_block (G.dind_block2)

    if (!G.badblocks)
        return;
    mark_inode(MINIX_BAD_INO);
    inode->i_nlinks = 1;
    inode->i_atime = inode->i_mtime = inode->i_ctime = CUR_TIME;
    inode->i_mode = S_IFREG + 0000;
    inode->i_size = G.badblocks * BLOCK_SIZE;
    zone = next(0);
    for (i = 0; i < 7; i++) {
        inode->i_zone[i] = zone;
        if (!NEXT_BAD)
            goto end_bad;
    }
    inode->i_zone[7] = ind = get_free_block();
    memset(ind_block, 0, BLOCK_SIZE);
    for (i = 0; i < 256; i++) {
        ind_block[i] = zone;
        if (!NEXT_BAD)
            goto end_bad;
    }
    inode->i_zone[8] = dind = get_free_block();
    memset(dind_block, 0, BLOCK_SIZE);
    for (i = 0; i < 256; i++) {
        write_block(ind, (char *) ind_block);
        dind_block[i] = ind = get_free_block();
        memset(ind_block, 0, BLOCK_SIZE);
        for (j = 0; j < 256; j++) {
            ind_block[j] = zone;
            if (!NEXT_BAD)
                goto end_bad;
        }
    }
    /* Could make triple indirect block here */
    bb_error_msg_and_die("too many bad blocks");
 end_bad:
    if (ind)
        write_block(ind, (char *) ind_block);
    if (dind)
        write_block(dind, (char *) dind_block);
#undef ind_block
#undef dind_block
}
#else
void make_bad_inode2(void);
#endif

static void make_root_inode(void)
{
    struct minix1_inode *inode = &INODE_BUF1[MINIX_ROOT_INO];

    mark_inode(MINIX_ROOT_INO);
    inode->i_zone[0] = get_free_block();
    inode->i_nlinks = 2;
    inode->i_time = CUR_TIME;
    if (G.badblocks)
        inode->i_size = 3 * G.dirsize;
    else {
        G.root_block[2 * G.dirsize] = '\0';
        G.root_block[2 * G.dirsize + 1] = '\0';
        inode->i_size = 2 * G.dirsize;
    }
    inode->i_mode = S_IFDIR + 0755;
    inode->i_uid = GETUID;
    if (inode->i_uid)
        inode->i_gid = GETGID;
    write_block(inode->i_zone[0], G.root_block);
}

#if ENABLE_FEATURE_MINIX2
static void make_root_inode2(void)
{
    struct minix2_inode *inode = &INODE_BUF2[MINIX_ROOT_INO];

    mark_inode(MINIX_ROOT_INO);
    inode->i_zone[0] = get_free_block();
    inode->i_nlinks = 2;
    inode->i_atime = inode->i_mtime = inode->i_ctime = CUR_TIME;
    if (G.badblocks)
        inode->i_size = 3 * G.dirsize;
    else {
        G.root_block[2 * G.dirsize] = '\0';
        G.root_block[2 * G.dirsize + 1] = '\0';
        inode->i_size = 2 * G.dirsize;
    }
    inode->i_mode = S_IFDIR + 0755;
    inode->i_uid = GETUID;
    if (inode->i_uid)
        inode->i_gid = GETGID;
    write_block(inode->i_zone[0], G.root_block);
}
#else
void make_root_inode2(void);
#endif

/*
 * Perform a test of a block; return the number of
 * blocks readable.
 */
static size_t do_check(char *buffer, size_t try, unsigned current_block)
{
    ssize_t got;

    /* Seek to the correct loc. */
    msg_eol = "seek failed during testing of blocks";
    xlseek(dev_fd, current_block * BLOCK_SIZE, SEEK_SET);
    msg_eol = "\n";

    /* Try the read */
    got = read(dev_fd, buffer, try * BLOCK_SIZE);
    if (got < 0)
        got = 0;
    try = ((size_t)got) / BLOCK_SIZE;

    if (got & (BLOCK_SIZE - 1))
        fprintf(stderr, "Short read at block %u\n", (unsigned)(current_block + try));
    return try;
}

static void alarm_intr(int alnum UNUSED_PARAM)
{
    if (G.currently_testing >= SB_ZONES)
        return;
    signal(SIGALRM, alarm_intr);
    alarm(5);
    if (!G.currently_testing)
        return;
    printf("%d ...", G.currently_testing);
    fflush_all();
}

static void check_blocks(void)
{
    size_t try, got;

    G.currently_testing = 0;
    signal(SIGALRM, alarm_intr);
    alarm(5);
    while (G.currently_testing < SB_ZONES) {
        msg_eol = "seek failed in check_blocks";
        xlseek(dev_fd, G.currently_testing * BLOCK_SIZE, SEEK_SET);
        msg_eol = "\n";
        try = TEST_BUFFER_BLOCKS;
        if (G.currently_testing + try > SB_ZONES)
            try = SB_ZONES - G.currently_testing;
        got = do_check(G.check_blocks_buffer, try, G.currently_testing);
        G.currently_testing += got;
        if (got == try)
            continue;
        if (G.currently_testing < SB_FIRSTZONE)
            bb_error_msg_and_die("bad blocks before data-area: cannot make fs");
        mark_zone(G.currently_testing);
        G.badblocks++;
        G.currently_testing++;
    }
    alarm(0);
    printf("%d bad block(s)\n", G.badblocks);
}

static void get_list_blocks(char *filename)
{
    FILE *listfile;
    unsigned long blockno;

    listfile = xfopen_for_read(filename);
    while (!feof(listfile)) {
        fscanf(listfile, "%ld\n", &blockno);
        mark_zone(blockno);
        G.badblocks++;
    }
    printf("%d bad block(s)\n", G.badblocks);
}

static void setup_tables(void)
{
    unsigned long inodes;
    unsigned norm_firstzone;
    unsigned sb_zmaps;
    unsigned i;

    /* memset(G.superblock_buffer, 0, BLOCK_SIZE); */
    /* memset(G.boot_block_buffer, 0, 512); */
    SB_MAGIC = G.magic;
    SB_ZONE_SIZE = 0;
    SB_MAXSIZE = version2 ? 0x7fffffff : (7 + 512 + 512 * 512) * 1024;
    if (version2)
        SB.s_zones = G.total_blocks;
    else
        SB.s_nzones = G.total_blocks;

    /* some magic nrs: 1 inode / 3 blocks */
    if (G.req_nr_inodes == 0)
        inodes = G.total_blocks / 3;
    else
        inodes = G.req_nr_inodes;
    /* Round up inode count to fill block size */
    if (version2)
        inodes = (inodes + MINIX2_INODES_PER_BLOCK - 1) &
                         ~(MINIX2_INODES_PER_BLOCK - 1);
    else
        inodes = (inodes + MINIX1_INODES_PER_BLOCK - 1) &
                         ~(MINIX1_INODES_PER_BLOCK - 1);
    if (inodes > 65535)
        inodes = 65535;
    SB_INODES = inodes;
    SB_IMAPS = div_roundup(SB_INODES + 1, BITS_PER_BLOCK);

    /* Real bad hack but overwise mkfs.minix can be thrown
     * in infinite loop...
     * try:
     * dd if=/dev/zero of=test.fs count=10 bs=1024
     * mkfs.minix -i 200 test.fs
     */
    /* This code is not insane: NORM_FIRSTZONE is not a constant,
     * it is calculated from SB_INODES, SB_IMAPS and SB_ZMAPS */
    i = 999;
    SB_ZMAPS = 0;
    do {
        norm_firstzone = NORM_FIRSTZONE;
        sb_zmaps = div_roundup(G.total_blocks - norm_firstzone + 1, BITS_PER_BLOCK);
        if (SB_ZMAPS == sb_zmaps) goto got_it;
        SB_ZMAPS = sb_zmaps;
        /* new SB_ZMAPS, need to recalc NORM_FIRSTZONE */
    } while (--i);
    bb_error_msg_and_die("incompatible size/inode count, try different -i N");
 got_it:

    SB_FIRSTZONE = norm_firstzone;
    G.inode_map = xmalloc(SB_IMAPS * BLOCK_SIZE);
    G.zone_map = xmalloc(SB_ZMAPS * BLOCK_SIZE);
    memset(G.inode_map, 0xff, SB_IMAPS * BLOCK_SIZE);
    memset(G.zone_map, 0xff, SB_ZMAPS * BLOCK_SIZE);
    for (i = SB_FIRSTZONE; i < SB_ZONES; i++)
        unmark_zone(i);
    for (i = MINIX_ROOT_INO; i <= SB_INODES; i++)
        unmark_inode(i);
    G.inode_buffer = xzalloc(INODE_BUFFER_SIZE);
    printf("%ld inodes\n", (long)SB_INODES);
    printf("%ld blocks\n", (long)SB_ZONES);
    printf("Firstdatazone=%ld (%ld)\n", (long)SB_FIRSTZONE, (long)norm_firstzone);
    printf("Zonesize=%d\n", BLOCK_SIZE << SB_ZONE_SIZE);
    printf("Maxsize=%ld\n", (long)SB_MAXSIZE);
}

int mkfs_minix_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int mkfs_minix_main(int argc UNUSED_PARAM, char **argv)
{
    unsigned opt;
    char *tmp;
    struct stat statbuf;
    char *str_i;
    char *listfile = NULL;

    INIT_G();
/* default (changed to 30, per Linus's suggestion, Sun Nov 21 08:05:07 1993) */
    G.namelen = 30;
    G.dirsize = 32;
    G.magic = MINIX1_SUPER_MAGIC2;

    if (INODE_SIZE1 * MINIX1_INODES_PER_BLOCK != BLOCK_SIZE)
        bb_error_msg_and_die("bad inode size");
#if ENABLE_FEATURE_MINIX2
    if (INODE_SIZE2 * MINIX2_INODES_PER_BLOCK != BLOCK_SIZE)
        bb_error_msg_and_die("bad inode size");
#endif

    opt_complementary = "n+"; /* -n N */
    opt = getopt32(argv, "ci:l:n:v", &str_i, &listfile, &G.namelen);
    argv += optind;
    //if (opt & 1) -c
    if (opt & 2) G.req_nr_inodes = xatoul(str_i); // -i
    //if (opt & 4) -l
    if (opt & 8) { // -n
        if (G.namelen == 14) G.magic = MINIX1_SUPER_MAGIC;
        else if (G.namelen == 30) G.magic = MINIX1_SUPER_MAGIC2;
        else bb_show_usage();
        G.dirsize = G.namelen + 2;
    }
    if (opt & 0x10) { // -v
#if ENABLE_FEATURE_MINIX2
        version2 = 1;
#else
        bb_error_msg_and_die("not compiled with minix v2 support");
#endif
    }

    G.device_name = *argv++;
    if (!G.device_name)
        bb_show_usage();
    if (*argv)
        G.total_blocks = xatou32(*argv);
    else
        G.total_blocks = get_size(G.device_name) / 1024;

    if (G.total_blocks < 10)
        bb_error_msg_and_die("must have at least 10 blocks");

    if (version2) {
        G.magic = MINIX2_SUPER_MAGIC2;
        if (G.namelen == 14)
            G.magic = MINIX2_SUPER_MAGIC;
    } else if (G.total_blocks > 65535)
        G.total_blocks = 65535;

    /* Check if it is mounted */
    if (find_mount_point(G.device_name, 0))
        bb_error_msg_and_die("can't format mounted filesystem");

    xmove_fd(xopen(G.device_name, O_RDWR), dev_fd);
    xfstat(dev_fd, &statbuf, G.device_name);
    if (!S_ISBLK(statbuf.st_mode))
        opt &= ~1; // clear -c (check)

/* I don't know why someone has special code to prevent mkfs.minix
 * on IDE devices. Why IDE but not SCSI, etc?... */
#if 0
    else if (statbuf.st_rdev == 0x0300 || statbuf.st_rdev == 0x0340)
        /* what is this? */
        bb_error_msg_and_die("will not try "
            "to make filesystem on '%s'", G.device_name);
#endif

    tmp = G.root_block;
    *(short *) tmp = 1;
    strcpy(tmp + 2, ".");
    tmp += G.dirsize;
    *(short *) tmp = 1;
    strcpy(tmp + 2, "..");
    tmp += G.dirsize;
    *(short *) tmp = 2;
    strcpy(tmp + 2, ".badblocks");

    setup_tables();

    if (opt & 1) // -c ?
        check_blocks();
    else if (listfile)
        get_list_blocks(listfile);

    if (version2) {
        make_root_inode2();
        make_bad_inode2();
    } else {
        make_root_inode();
        make_bad_inode();
    }

    mark_good_blocks();
    write_tables();
    return 0;
}