check.c

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/* check.c - Check and repair a PC/MS-DOS filesystem

   Copyright (C) 1993 Werner Almesberger <werner.almesberger@lrc.di.epfl.ch>
   Copyright (C) 1998 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
   Copyright (C) 2008-2014 Daniel Baumann <mail@daniel-baumann.ch>
   Copyright (C) 2015 Andreas Bombe <aeb@debian.org>

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program. If not, see <http://www.gnu.org/licenses/>.

   The complete text of the GNU General Public License
   can be found in /usr/share/common-licenses/GPL-3 file.
*/

/* FAT32, VFAT, Atari format support, and various fixes additions May 1998
 * by Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> */

#include "vfatlib.h"

#define NDEBUG
#include <debug.h>


/* the longest path on the filesystem that can be handled by path_name() */
#define PATH_NAME_MAX 1023

static DOS_FILE *root;

/* get start field of a dir entry */
#define FSTART(p,fs) \
  ((uint32_t)le16toh(p->dir_ent.start) | \
   (fs->fat_bits == 32 ? le16toh(p->dir_ent.starthi) << 16 : 0))

#define MODIFY(p,i,v)                   \
  do {                          \
    if (p->offset) {                    \
    p->dir_ent.i = v;               \
    fs_write(p->offset+offsetof(DIR_ENT,i),     \
         sizeof(p->dir_ent.i),&p->dir_ent.i);   \
    }                           \
  } while(0)

#define MODIFY_START(p,v,fs)                        \
  do {                                  \
    uint32_t __v = (v);                         \
    if (!p->offset) {                           \
    /* writing to fake entry for FAT32 root dir */          \
    if (!__v) die("Oops, deleting FAT32 root dir!");        \
    fs->root_cluster = __v;                     \
    p->dir_ent.start = htole16(__v&0xffff);             \
    p->dir_ent.starthi = htole16(__v>>16);              \
    __v = htole32(__v);                     \
    fs_write(offsetof(struct boot_sector,root_cluster),     \
             sizeof(((struct boot_sector *)0)->root_cluster),   \
         &__v);                         \
    }                                   \
    else {                              \
    MODIFY(p,start,htole16((__v)&0xffff));              \
    if (fs->fat_bits == 32)                     \
        MODIFY(p,starthi,htole16((__v)>>16));           \
    }                                   \
  } while(0)

off_t alloc_rootdir_entry(DOS_FS * fs, DIR_ENT * de, const char *pattern, int gen_name)
{
    static int curr_num = 0;
    off_t offset;

    if (fs->root_cluster) {
    DIR_ENT d2;
    int i = 0, got = 0;
    uint32_t clu_num, prev = 0;
    off_t offset2;

    clu_num = fs->root_cluster;
    offset = cluster_start(fs, clu_num);
    while (clu_num > 0 && clu_num != -1) {
        fs_read(offset, sizeof(DIR_ENT), &d2);
        if (IS_FREE(d2.name) && d2.attr != VFAT_LN_ATTR) {
        got = 1;
        break;
        }
        i += sizeof(DIR_ENT);
        offset += sizeof(DIR_ENT);
        if ((i % fs->cluster_size) == 0) {
        prev = clu_num;
        if ((clu_num = next_cluster(fs, clu_num)) == 0 || clu_num == -1)
            break;
        offset = cluster_start(fs, clu_num);
        }
    }
    if (!got) {
        /* no free slot, need to extend root dir: alloc next free cluster
         * after previous one */
        if (!prev)
        die("Root directory has no cluster allocated!");
        for (clu_num = prev + 1; clu_num != prev; clu_num++) {
        FAT_ENTRY entry;

        if (clu_num >= fs->data_clusters + 2)
            clu_num = 2;
        get_fat(&entry, fs->fat, clu_num, fs);
        if (!entry.value)
            break;
        }
        if (clu_num == prev)
        die("Root directory full and no free cluster");
        set_fat(fs, prev, clu_num);
        set_fat(fs, clu_num, -1);
        set_owner(fs, clu_num, get_owner(fs, fs->root_cluster));
        /* clear new cluster */
        memset(&d2, 0, sizeof(d2));
        offset = cluster_start(fs, clu_num);
        for (i = 0; i < fs->cluster_size; i += sizeof(DIR_ENT))
        fs_write(offset + i, sizeof(d2), &d2);
    }
    memset(de, 0, sizeof(DIR_ENT));
    if (gen_name) {
        while (1) {
        char expanded[12];
        sprintf(expanded, pattern, curr_num);
        memcpy(de->name, expanded, MSDOS_NAME);
        clu_num = fs->root_cluster;
        i = 0;
        offset2 = cluster_start(fs, clu_num);
        while (clu_num > 0 && clu_num != -1) {
            fs_read(offset2, sizeof(DIR_ENT), &d2);
            if (offset2 != offset &&
            !strncmp((const char *)d2.name, (const char *)de->name,
                 MSDOS_NAME))
            break;
            i += sizeof(DIR_ENT);
            offset2 += sizeof(DIR_ENT);
            if ((i % fs->cluster_size) == 0) {
            if ((clu_num = next_cluster(fs, clu_num)) == 0 ||
                clu_num == -1)
                break;
            offset2 = cluster_start(fs, clu_num);
            }
        }
        if (clu_num == 0 || clu_num == -1)
            break;
        if (++curr_num >= 10000)
            die("Unable to create unique name");
        }
    } else {
        memcpy(de->name, pattern, MSDOS_NAME);
    }
    } else {
    DIR_ENT *root;
    int next_free = 0, scan;

    root = alloc(fs->root_entries * sizeof(DIR_ENT));
    fs_read(fs->root_start, fs->root_entries * sizeof(DIR_ENT), root);

    while (next_free < fs->root_entries)
        if (IS_FREE(root[next_free].name) &&
        root[next_free].attr != VFAT_LN_ATTR)
        break;
        else
        next_free++;
    if (next_free == fs->root_entries)
        die("Root directory is full.");
    offset = fs->root_start + next_free * sizeof(DIR_ENT);
    memset(de, 0, sizeof(DIR_ENT));
    if (gen_name) {
        while (1) {
        char expanded[12];
        sprintf(expanded, pattern, curr_num);
        memcpy(de->name, expanded, MSDOS_NAME);
        for (scan = 0; scan < fs->root_entries; scan++)
            if (scan != next_free &&
            !strncmp((const char *)root[scan].name,
                 (const char *)de->name, MSDOS_NAME))
            break;
        if (scan == fs->root_entries)
            break;
        if (++curr_num >= 10000)
            die("Unable to create unique name");
        }
    } else {
        memcpy(de->name, pattern, MSDOS_NAME);
    }
    free(root);
    }
    ++n_files;
    return offset;
}

static char *path_name(DOS_FILE * file)
{
    static char path[PATH_NAME_MAX * 2];

    if (!file)
    *path = 0;      /* Reached the root directory */
    else {
    if (strlen(path_name(file->parent)) > PATH_NAME_MAX)
        die("Path name too long.");
    if (strcmp(path, "/") != 0)
        strcat(path, "/");

    /* Append the long name to the path,
     * or the short name if there isn't a long one
     */
    strcpy(strrchr(path, 0),
           file->lfn ? file->lfn : file_name(file->dir_ent.name));
    }
    return path;
}

static const int day_n[] =
    {   0,  31,  59,  90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, 0 };
/*    Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec              */

/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */

static time_t date_dos2unix(unsigned short time, unsigned short date)
{
    int month, year;
    time_t secs;

    month = ((date >> 5) & 15) - 1;
    if (month < 0) {
    /* make sure that nothing bad happens if the month bits were zero */
    month = 0;
    }
    year = date >> 9;
    secs =
    (time & 31) * 2 + 60 * ((time >> 5) & 63) + (time >> 11) * 3600 +
    86400 * ((date & 31) - 1 + day_n[month] + (year / 4) + year * 365 -
         ((year & 3) == 0 && month < 2 ? 1 : 0) + 3653);
    /* days since 1.1.70 plus 80's leap day */
    return secs;
}

#ifdef __REACTOS__ // Old version!

static char *file_stat(DOS_FILE * file)
{
    static char temp[100];
    char tmp[100];
    time_t date;
    LARGE_INTEGER time;
    TIME_FIELDS time_fields;

    date = date_dos2unix(le16toh(file->dir_ent.time), le16toh(file->dir_ent.date));

    RtlSecondsSince1970ToTime(date, &time);
    RtlTimeToTimeFields(&time, &time_fields);

    _snprintf(tmp, sizeof(tmp), "%d:%d:%d %d.%d.%d",
        time_fields.Hour, time_fields.Minute, time_fields.Second,
        time_fields.Day, time_fields.Month, time_fields.Year);

    _snprintf(temp, sizeof(temp), "  Size %u bytes, date %s", le32toh(file->dir_ent.size), tmp);
    return temp;
}

#else

static char *file_stat(DOS_FILE * file)
{
    static char temp[100];
    struct tm *tm;
    char tmp[100];
    time_t date;

    date =
    date_dos2unix(le16toh(file->dir_ent.time), le16toh(file->dir_ent.date));
    tm = localtime(&date);
    strftime(tmp, 99, "%H:%M:%S %b %d %Y", tm);
    sprintf(temp, "  Size %u bytes, date %s", le32toh(file->dir_ent.size), tmp);
    return temp;
}

#endif

static int bad_name(DOS_FILE * file)
{
    int i, spc, suspicious = 0;
    const char *bad_chars = atari_format ? "*?\\/:" : "*?<>|\"\\/:";
    const unsigned char *name = file->dir_ent.name;
    const unsigned char *ext = name + 8;

    /* Do not complain about (and auto-correct) the extended attribute files
     * of OS/2. */
    if (strncmp((const char *)name, "EA DATA  SF", 11) == 0 ||
    strncmp((const char *)name, "WP ROOT  SF", 11) == 0)
    return 0;

    /* check if we have neither a long filename nor a short name */
    if ((file->lfn == NULL) && (file->dir_ent.lcase & FAT_NO_83NAME)) {
    return 1;
    }

    /* don't complain about the dummy 11 bytes used by patched Linux
       kernels */
    if (file->dir_ent.lcase & FAT_NO_83NAME)
    return 0;

    for (i = 0; i < MSDOS_NAME; i++) {
    if (name[i] < ' ' || name[i] == 0x7f)
        return 1;
    if (name[i] > 0x7f)
        ++suspicious;
    if (strchr(bad_chars, name[i]))
        return 1;
    }

    spc = 0;
    for (i = 0; i < 8; i++) {
    if (name[i] == ' ')
        spc = 1;
    else if (spc)
        /* non-space after a space not allowed, space terminates the name
         * part */
        return 1;
    }

    spc = 0;
    for (i = 0; i < 3; i++) {
    if (ext[i] == ' ')
        spc = 1;
    else if (spc)
        /* non-space after a space not allowed, space terminates the ext
         * part */
        return 1;
    }

    /* Under GEMDOS, chars >= 128 are never allowed. */
    if (atari_format && suspicious)
    return 1;

#ifdef __REACTOS__ // Old !!!!!!!!!!!!!!!

    /* Only complain about too much suspicious chars in interactive mode,
     * never correct them automatically. The chars are all basically ok, so we
     * shouldn't auto-correct such names. */
    if (interactive && suspicious > 6)
    return 1;
    return 0;

#else

    /* Under MS-DOS and Windows, chars >= 128 in short names are valid
     * (but these characters can be visualised differently depending on
     * local codepage: CP437, CP866, etc). The chars are all basically ok,
     * so we shouldn't auto-correct such names. */
    return 0;

#endif
}

static void lfn_remove(off_t from, off_t to)
{
    DIR_ENT empty;

    /* New dir entry is zeroed except first byte, which is set to 0xe5.
     * This is to avoid that some FAT-reading OSes (not Linux! ;) stop reading
     * a directory at the first zero entry...
     */
    memset(&empty, 0, sizeof(empty));
    empty.name[0] = DELETED_FLAG;

    for (; from < to; from += sizeof(empty)) {
    fs_write(from, sizeof(DIR_ENT), &empty);
    }
}

static void drop_file(DOS_FS * fs, DOS_FILE * file)
{
    uint32_t cluster;

    MODIFY(file, name[0], DELETED_FLAG);
    if (file->lfn)
    lfn_remove(file->lfn_offset, file->offset);
    for (cluster = FSTART(file, fs); cluster > 0 && cluster <
     fs->data_clusters + 2; cluster = next_cluster(fs, cluster))
    set_owner(fs, cluster, NULL);
    --n_files;
}

static void truncate_file(DOS_FS * fs, DOS_FILE * file, uint32_t clusters)
{
    int deleting;
    uint32_t walk, next;

    walk = FSTART(file, fs);
    if ((deleting = !clusters))
    MODIFY_START(file, 0, fs);
    while (walk > 0 && walk != -1) {
    next = next_cluster(fs, walk);
    if (deleting)
        set_fat(fs, walk, 0);
    else if ((deleting = !--clusters))
        set_fat(fs, walk, -1);
    walk = next;
    }
}

static void auto_rename(DOS_FILE * file)
{
    DOS_FILE *first, *walk;
    uint32_t number;

    if (!file->offset)
    return;         /* cannot rename FAT32 root dir */
    first = file->parent ? file->parent->first : root;
    number = 0;
    while (1) {
    char num[8];
    sprintf(num, "%07lu", (unsigned long)number);
    memcpy(file->dir_ent.name, "FSCK", 4);
    memcpy(file->dir_ent.name + 4, num, 7);
    for (walk = first; walk; walk = walk->next)
        if (walk != file
        && !strncmp((const char *)walk->dir_ent.name,
                (const char *)file->dir_ent.name, MSDOS_NAME))
        break;
    if (!walk) {
        if (file->dir_ent.lcase & FAT_NO_83NAME) {
        /* as we only assign a new 8.3 filename, reset flag that 8.3 name is not
           present */
        file->dir_ent.lcase &= ~FAT_NO_83NAME;
        /* reset the attributes, only keep DIR and VOLUME */
        file->dir_ent.attr &= ~(ATTR_DIR | ATTR_VOLUME);
        fs_write(file->offset, MSDOS_NAME + 2, &file->dir_ent);
        } else {
        fs_write(file->offset, MSDOS_NAME, file->dir_ent.name);
        }
        if (file->lfn)
        lfn_fix_checksum(file->lfn_offset, file->offset,
                 (const char *)file->dir_ent.name);
        return;
    }
    number++;
    if (number > 9999999) {
        die("Too many files need repair.");
    }
    }
    die("Can't generate a unique name.");
}

static void rename_file(DOS_FILE * file)
{
#ifndef __REACTOS__
    unsigned char name[46];
    unsigned char *walk, *here;
#endif

    if (!file->offset) {
#ifndef __REACTOS__
    printf("Cannot rename FAT32 root dir\n");
#else
    VfatPrint( "Cannot rename FAT32 root dir\n" );
#endif
    return;         /* cannot rename FAT32 root dir */
    }
    while (1) {
#ifndef __REACTOS__
    printf("New name: ");
    fflush(stdout);
    if (fgets((char *)name, 45, stdin)) {
        if ((here = (unsigned char *)strchr((const char *)name, '\n')))
        *here = 0;
        for (walk = (unsigned char *)strrchr((const char *)name, 0);
         walk >= name && (*walk == ' ' || *walk == '\t'); walk--) ;
        walk[1] = 0;
        for (walk = name; *walk == ' ' || *walk == '\t'; walk++) ;
        if (file_cvt(walk, file->dir_ent.name)) {
        if (file->dir_ent.lcase & FAT_NO_83NAME) {
            /* as we only assign a new 8.3 filename, reset flag that 8.3 name is not
               present */
            file->dir_ent.lcase &= ~FAT_NO_83NAME;
            /* reset the attributes, only keep DIR and VOLUME */
            file->dir_ent.attr &= ~(ATTR_DIR | ATTR_VOLUME);
            fs_write(file->offset, MSDOS_NAME + 2, &file->dir_ent);
        } else {
            fs_write(file->offset, MSDOS_NAME, file->dir_ent.name);
        }
        if (file->lfn)
            lfn_fix_checksum(file->lfn_offset, file->offset,
                     (const char *)file->dir_ent.name);
        return;
        }
    }
#else
    return;
#endif
    }
}

static int handle_dot(DOS_FS * fs, DOS_FILE * file, int dots)
{
    const char *name;

    name =
    strncmp((const char *)file->dir_ent.name, MSDOS_DOT,
        MSDOS_NAME) ? ".." : ".";
    if (!(file->dir_ent.attr & ATTR_DIR)) {
    printf("%s\n  Is a non-directory.\n", path_name(file));
    if (interactive)
        printf("1) Drop it\n2) Auto-rename\n3) Rename\n"
           "4) Convert to directory\n");
#ifndef __REACTOS__
    else
#else
    else if (rw)
#endif
        printf("  Auto-renaming it.\n");
#ifdef __REACTOS__
    if (rw || interactive) {
#endif
    switch (interactive ? get_key("1234", "?") : '2') {
    case '1':
        drop_file(fs, file);
        return 1;
    case '2':
        auto_rename(file);
        printf("  Renamed to %s\n", file_name(file->dir_ent.name));
        return 0;
    case '3':
        rename_file(file);
        return 0;
    case '4':
        MODIFY(file, size, htole32(0));
        MODIFY(file, attr, file->dir_ent.attr | ATTR_DIR);
        break;
#ifdef __REACTOS__
        }
#endif
    }
    }
    if (!dots) {
    printf("Root contains directory \"%s\". Dropping it.\n", name);
    drop_file(fs, file);
    return 1;
    }
    return 0;
}

static int check_file(DOS_FS * fs, DOS_FILE * file)
{
    DOS_FILE *owner;
    int restart;
    uint32_t expect, curr, this, clusters, prev, walk, clusters2;

    if (file->dir_ent.attr & ATTR_DIR) {
    if (le32toh(file->dir_ent.size)) {
#ifndef __REACTOS__
        printf("%s\n  Directory has non-zero size. Fixing it.\n",
           path_name(file));
#else
        printf("%s\n  Directory has non-zero size.%s\n",
           path_name(file), (rw) ? " Fixing it." : "");
        if (rw)
#endif
        MODIFY(file, size, htole32(0));
    }
    if (file->parent
        && !strncmp((const char *)file->dir_ent.name, MSDOS_DOT,
            MSDOS_NAME)) {
        expect = FSTART(file->parent, fs);
        if (FSTART(file, fs) != expect) {
        printf("%s\n  Start (%lu) does not point to parent (%lu)\n",
               path_name(file), (unsigned long)FSTART(file, fs), (long)expect);
#ifdef __REACTOS__
        if (rw)
#endif
        MODIFY_START(file, expect, fs);
        }
        return 0;
    }
    if (file->parent
        && !strncmp((const char *)file->dir_ent.name, MSDOS_DOTDOT,
            MSDOS_NAME)) {
        expect =
        file->parent->parent ? FSTART(file->parent->parent, fs) : 0;
        if (fs->root_cluster && expect == fs->root_cluster)
        expect = 0;
        if (FSTART(file, fs) != expect) {
        printf("%s\n  Start (%lu) does not point to .. (%lu)\n",
               path_name(file), (unsigned long)FSTART(file, fs), (unsigned long)expect);
#ifdef __REACTOS__
        if (rw)
#endif
        MODIFY_START(file, expect, fs);
        }
        return 0;
    }
    if (FSTART(file, fs) == 0) {
#ifndef __REACTOS__
        printf("%s\n Start does point to root directory. Deleting dir. \n",
           path_name(file));
#else
        printf("%s\n Start does point to root directory.%s\n",
           path_name(file), (rw) ? " Deleting dir. " : "");
        if (rw)
#endif
        MODIFY(file, name[0], DELETED_FLAG);
        return 0;
    }
    }
    if (FSTART(file, fs) == 1) {
    printf("%s\n  Bad start cluster 1. Truncating file.\n",
           path_name(file));
    if (!file->offset)
        die("Bad FAT32 root directory! (bad start cluster 1)\n");
#ifdef __REACTOS__
    if (rw)
#endif
    MODIFY_START(file, 0, fs);
    }
    if (FSTART(file, fs) >= fs->data_clusters + 2) {
    printf
#ifndef __REACTOS__
        ("%s\n  Start cluster beyond limit (%lu > %lu). Truncating file.\n",
         path_name(file), (unsigned long)FSTART(file, fs),
         (unsigned long)(fs->data_clusters + 1));
#else
        ("%s\n  Start cluster beyond limit (%lu > %lu).%s\n",
         path_name(file), (unsigned long)FSTART(file, fs),
         (unsigned long)(fs->data_clusters + 1),
         (rw) ? " Truncating file." : "");
#endif
    if (!file->offset)
        die("Bad FAT32 root directory! (start cluster beyond limit: %lu > %lu)\n",
        (unsigned long)FSTART(file, fs),
        (unsigned long)(fs->data_clusters + 1));
#ifdef __REACTOS__
    if (rw)
#endif
    MODIFY_START(file, 0, fs);
    }
    clusters = prev = 0;
    for (curr = FSTART(file, fs) ? FSTART(file, fs) :
     -1; curr != -1; curr = next_cluster(fs, curr)) {
    FAT_ENTRY curEntry;
    get_fat(&curEntry, fs->fat, curr, fs);

    if (!curEntry.value || bad_cluster(fs, curr)) {
#ifndef __REACTOS__
        printf("%s\n  Contains a %s cluster (%lu). Assuming EOF.\n",
           path_name(file), curEntry.value ? "bad" : "free", (unsigned long)curr);
#else
        printf("%s\n  Contains a %s cluster (%lu).%s\n",
           path_name(file), curEntry.value ? "bad" : "free", (unsigned long)curr,
           (rw) ? " Assuming EOF." : "");
#endif
        if (prev)
#ifdef __REACTOS__
        {
        if (rw)
#endif
        set_fat(fs, prev, -1);
#ifdef __REACTOS__
        }
#endif
        else if (!file->offset)
        die("FAT32 root dir starts with a bad cluster!");
        else
#ifdef __REACTOS__
        if (rw)
#endif
        MODIFY_START(file, 0, fs);
        break;
    }
    if (!(file->dir_ent.attr & ATTR_DIR) && le32toh(file->dir_ent.size) <=
        (uint64_t)clusters * fs->cluster_size) {
#ifdef __REACTOS__
        if (rw) {
#endif
        printf
        ("%s\n  File size is %u bytes, cluster chain length is > %llu "
         "bytes.\n  Truncating file to %u bytes.\n", path_name(file),
         le32toh(file->dir_ent.size),
         (unsigned long long)clusters * fs->cluster_size,
         le32toh(file->dir_ent.size));
        truncate_file(fs, file, clusters);
#ifdef __REACTOS__
        } else {
        printf
        ("%s\n  File size is %u bytes, cluster chain length is > %llu "
         "bytes.\n", path_name(file),
         le32toh(file->dir_ent.size),
         (unsigned long long)clusters * fs->cluster_size);
        }
#endif
        break;
    }
    if ((owner = get_owner(fs, curr))) {
        int do_trunc = 0;
        printf("%s  and\n", path_name(owner));
        printf("%s\n  share clusters.\n", path_name(file));
        clusters2 = 0;
        for (walk = FSTART(owner, fs); walk > 0 && walk != -1; walk =
         next_cluster(fs, walk))
        if (walk == curr)
            break;
        else
            clusters2++;
        restart = file->dir_ent.attr & ATTR_DIR;
#ifndef __REACTOS__
        if (!owner->offset) {
#else
        if (!owner->offset && rw) {
#endif
        printf("  Truncating second to %llu bytes because first "
               "is FAT32 root dir.\n",
               (unsigned long long)clusters * fs->cluster_size);
        do_trunc = 2;
#ifndef __REACTOS__
        } else if (!file->offset) {
#else
        } else if (!file->offset && rw) {
#endif
        printf("  Truncating first to %llu bytes because second "
               "is FAT32 root dir.\n",
               (unsigned long long)clusters2 * fs->cluster_size);
        do_trunc = 1;
        } else if (interactive)
        printf("1) Truncate first to %llu bytes%s\n"
               "2) Truncate second to %llu bytes\n",
               (unsigned long long)clusters2 * fs->cluster_size,
               restart ? " and restart" : "",
               (unsigned long long)clusters * fs->cluster_size);
        else
#ifdef __REACTOS__
        if (rw)
#endif
        printf("  Truncating second to %llu bytes.\n",
               (unsigned long long)clusters * fs->cluster_size);
#ifndef __REACTOS__
        if (do_trunc != 2
        && (do_trunc == 1
#else
        if ((do_trunc != 2 && rw)
        && ((do_trunc == 1 && rw)
#endif
            || (interactive && get_key("12", "?") == '1'))) {
        prev = 0;
        clusters = 0;
        for (this = FSTART(owner, fs); this > 0 && this != -1; this =
             next_cluster(fs, this)) {
            if (this == curr) {
            if (prev)
                set_fat(fs, prev, -1);
            else
                MODIFY_START(owner, 0, fs);
            MODIFY(owner, size,
                   htole32((uint64_t)clusters *
                       fs->cluster_size));
            if (restart)
                return 1;
            while (this > 0 && this != -1) {
                set_owner(fs, this, NULL);
                this = next_cluster(fs, this);
            }
            this = curr;
            break;
            }
            clusters++;
            prev = this;
        }
        if (this != curr)
            die("Internal error: didn't find cluster %d in chain"
            " starting at %d", curr, FSTART(owner, fs));
        } else {
        if (prev)
            set_fat(fs, prev, -1);
        else
            MODIFY_START(file, 0, fs);
        break;
        }
    }
    set_owner(fs, curr, file);
    clusters++;
    prev = curr;
    }
    if (!(file->dir_ent.attr & ATTR_DIR) && le32toh(file->dir_ent.size) >
#ifndef __REACTOS__
    (uint64_t)clusters * fs->cluster_size) {
#else
    (uint64_t)clusters * fs->cluster_size && rw) {
#endif
    printf
        ("%s\n  File size is %u bytes, cluster chain length is %llu bytes."
         "\n  Truncating file to %llu bytes.\n", path_name(file),
         le32toh(file->dir_ent.size),
         (unsigned long long)clusters * fs->cluster_size,
         (unsigned long long)clusters * fs->cluster_size);
    MODIFY(file, size,
           htole32((uint64_t)clusters * fs->cluster_size));
    }
    return 0;
}

static int check_files(DOS_FS * fs, DOS_FILE * start)
{
    while (start) {
    if (check_file(fs, start))
        return 1;
    start = start->next;
    }
    return 0;
}

static int check_dir(DOS_FS * fs, DOS_FILE ** root, int dots)
{
    DOS_FILE *parent, **walk, **scan;
    int dot, dotdot, skip, redo;
    int good, bad;

    if (!*root)
    return 0;
    parent = (*root)->parent;
    good = bad = 0;
    for (walk = root; *walk; walk = &(*walk)->next)
    if (bad_name(*walk))
        bad++;
    else
        good++;
    if (*root && parent && good + bad > 4 && bad > good / 2) {
    printf("%s\n  Has a large number of bad entries. (%d/%d)\n",
           path_name(parent), bad, good + bad);
    if (!dots)
        printf("  Not dropping root directory.\n");
#ifndef __REACTOS__
    else if (!interactive)
#else
    else if (!interactive || !rw)
#endif
        printf("  Not dropping it in auto-mode.\n");
    else if (get_key("yn", "Drop directory ? (y/n)") == 'y') {
        truncate_file(fs, parent, 0);
        MODIFY(parent, name[0], DELETED_FLAG);
        /* buglet: deleted directory stays in the list. */
        return 1;
    }
    }
    dot = dotdot = redo = 0;
    walk = root;
    while (*walk) {
    if (!strncmp
        ((const char *)((*walk)->dir_ent.name), MSDOS_DOT, MSDOS_NAME)
        || !strncmp((const char *)((*walk)->dir_ent.name), MSDOS_DOTDOT,
            MSDOS_NAME)) {
        if (handle_dot(fs, *walk, dots)) {
        *walk = (*walk)->next;
        continue;
        }
        if (!strncmp
        ((const char *)((*walk)->dir_ent.name), MSDOS_DOT, MSDOS_NAME))
        dot++;
        else
        dotdot++;
    }
    if (!((*walk)->dir_ent.attr & ATTR_VOLUME) && bad_name(*walk)) {
#ifndef __REACTOS__
        puts(path_name(*walk));
        printf("  Bad short file name (%s).\n",
           file_name((*walk)->dir_ent.name));
#else
        printf("%s\n  Bad short file name (%s).\n",
           path_name(*walk), file_name((*walk)->dir_ent.name));
#endif
        if (interactive)
        printf("1) Drop file\n2) Rename file\n3) Auto-rename\n"
               "4) Keep it\n");
        else
#ifdef __REACTOS__
        if (rw)
#endif
        printf("  Auto-renaming it.\n");
#ifdef __REACTOS__
        if (rw || interactive) {
#endif
        switch (interactive ? get_key("1234", "?") : '3') {
        case '1':
        drop_file(fs, *walk);
        walk = &(*walk)->next;
        continue;
        case '2':
        rename_file(*walk);
        redo = 1;
        break;
        case '3':
        auto_rename(*walk);
        printf("  Renamed to %s\n", file_name((*walk)->dir_ent.name));
        break;
        case '4':
        break;
#ifdef __REACTOS__
            }
#endif
        }
    }
    /* don't check for duplicates of the volume label */
    if (!((*walk)->dir_ent.attr & ATTR_VOLUME)) {
        scan = &(*walk)->next;
        skip = 0;
        while (*scan && !skip) {
        if (!((*scan)->dir_ent.attr & ATTR_VOLUME) &&
            !memcmp((*walk)->dir_ent.name, (*scan)->dir_ent.name,
                MSDOS_NAME)) {
            printf("%s\n  Duplicate directory entry.\n  First  %s\n",
               path_name(*walk), file_stat(*walk));
            printf("  Second %s\n", file_stat(*scan));
            if (interactive)
            printf
                ("1) Drop first\n2) Drop second\n3) Rename first\n"
                 "4) Rename second\n5) Auto-rename first\n"
                 "6) Auto-rename second\n");
            else
#ifdef __REACTOS__
            if (rw)
#endif
            printf("  Auto-renaming second.\n");
#ifdef __REACTOS__
            if (rw || interactive) {
#endif
            switch (interactive ? get_key("123456", "?") : '6') {
            case '1':
            drop_file(fs, *walk);
            *walk = (*walk)->next;
            skip = 1;
            break;
            case '2':
            drop_file(fs, *scan);
            *scan = (*scan)->next;
            continue;
            case '3':
            rename_file(*walk);
            printf("  Renamed to %s\n", path_name(*walk));
            redo = 1;
            break;
            case '4':
            rename_file(*scan);
            printf("  Renamed to %s\n", path_name(*walk));
            redo = 1;
            break;
            case '5':
            auto_rename(*walk);
            printf("  Renamed to %s\n",
                   file_name((*walk)->dir_ent.name));
            break;
            case '6':
            auto_rename(*scan);
            printf("  Renamed to %s\n",
                   file_name((*scan)->dir_ent.name));
            break;
#ifdef __REACTOS__
                }
#endif
            }
        }
        scan = &(*scan)->next;
        }
        if (skip)
        continue;
    }
    if (!redo)
        walk = &(*walk)->next;
    else {
        walk = root;
        dot = dotdot = redo = 0;
    }
    }
    if (dots && !dot)
    printf("%s\n  \".\" is missing. Can't fix this yet.\n",
           path_name(parent));
    if (dots && !dotdot)
    printf("%s\n  \"..\" is missing. Can't fix this yet.\n",
           path_name(parent));
    return 0;
}

static void test_file(DOS_FS * fs, DOS_FILE * file, int read_test)
{
    DOS_FILE *owner;
    uint32_t walk, prev, clusters, next_clu;

    prev = clusters = 0;
    for (walk = FSTART(file, fs); walk > 1 && walk < fs->data_clusters + 2;
     walk = next_clu) {
    next_clu = next_cluster(fs, walk);

    /* In this stage we are checking only for a loop within our own
     * cluster chain.
     * Cross-linking of clusters is handled in check_file()
     */
    if ((owner = get_owner(fs, walk))) {
        if (owner == file) {
        printf("%s\n  Circular cluster chain. Truncating to %lu "
               "cluster%s.\n", path_name(file), (unsigned long)clusters,
               clusters == 1 ? "" : "s");
        if (prev)
            set_fat(fs, prev, -1);
        else if (!file->offset)
            die("Bad FAT32 root directory! (bad start cluster)\n");
        else
            MODIFY_START(file, 0, fs);
        }
        break;
    }
    if (bad_cluster(fs, walk))
        break;
    if (read_test) {
        if (fs_test(cluster_start(fs, walk), fs->cluster_size)) {
        prev = walk;
        clusters++;
        } else {
        printf("%s\n  Cluster %lu (%lu) is unreadable. Skipping it.\n",
               path_name(file), (unsigned long)clusters, (unsigned long)walk);
        if (prev)
            set_fat(fs, prev, next_cluster(fs, walk));
        else
            MODIFY_START(file, next_cluster(fs, walk), fs);
        set_fat(fs, walk, -2);
        }
    } else {
        prev = walk;
        clusters++;
    }
    set_owner(fs, walk, file);
    }
    /* Revert ownership (for now) */
    for (walk = FSTART(file, fs); walk > 1 && walk < fs->data_clusters + 2;
     walk = next_cluster(fs, walk))
    if (bad_cluster(fs, walk))
        break;
    else if (get_owner(fs, walk) == file)
        set_owner(fs, walk, NULL);
    else
        break;
}

static void undelete(DOS_FS * fs, DOS_FILE * file)
{
    uint32_t clusters, left, prev, walk;

    clusters = left = (le32toh(file->dir_ent.size) + fs->cluster_size - 1) /
    fs->cluster_size;
    prev = 0;

    walk = FSTART(file, fs);

    while (left && (walk >= 2) && (walk < fs->data_clusters + 2)) {

    FAT_ENTRY curEntry;
    get_fat(&curEntry, fs->fat, walk, fs);

    if (!curEntry.value)
        break;

    left--;
    if (prev)
        set_fat(fs, prev, walk);
    prev = walk;
    walk++;
    }
    if (prev)
    set_fat(fs, prev, -1);
    else
    MODIFY_START(file, 0, fs);
    if (left)
    printf("Warning: Did only undelete %lu of %lu cluster%s.\n",
           (unsigned long)clusters - left, (unsigned long)clusters, clusters == 1 ? "" : "s");

}

static void new_dir(void)
{
    lfn_reset();
}

static void add_file(DOS_FS * fs, DOS_FILE *** chain, DOS_FILE * parent,
             off_t offset, FDSC ** cp)
{
    DOS_FILE *new;
    DIR_ENT de;
    FD_TYPE type;

    if (offset)
    fs_read(offset, sizeof(DIR_ENT), &de);
    else {
    /* Construct a DIR_ENT for the root directory */
    memset(&de, 0, sizeof de);
    memcpy(de.name, "           ", MSDOS_NAME);
    de.attr = ATTR_DIR;
    de.start = htole16(fs->root_cluster & 0xffff);
    de.starthi = htole16((fs->root_cluster >> 16) & 0xffff);
    }
    if ((type = file_type(cp, (char *)de.name)) != fdt_none) {
    if (type == fdt_undelete && (de.attr & ATTR_DIR))
        die("Can't undelete directories.");
    file_modify(cp, (char *)de.name);
    fs_write(offset, 1, &de);
    }
    if (IS_FREE(de.name)) {
    lfn_check_orphaned();
    return;
    }
    if (de.attr == VFAT_LN_ATTR) {
    lfn_add_slot(&de, offset);
    return;
    }
    new = qalloc(&mem_queue, sizeof(DOS_FILE));
    new->lfn = lfn_get(&de, &new->lfn_offset);
    new->offset = offset;
    memcpy(&new->dir_ent, &de, sizeof(de));
    new->next = new->first = NULL;
    new->parent = parent;
    if (type == fdt_undelete)
    undelete(fs, new);
    **chain = new;
    *chain = &new->next;
    if (list) {
    printf("Checking file %s", path_name(new));
    if (new->lfn)
        printf(" (%s)", file_name(new->dir_ent.name));  /* (8.3) */
    printf("\n");
    }
    /* Don't include root directory, '.', or '..' in the total file count */
    if (offset &&
    strncmp((const char *)de.name, MSDOS_DOT, MSDOS_NAME) != 0 &&
    strncmp((const char *)de.name, MSDOS_DOTDOT, MSDOS_NAME) != 0)
    ++n_files;
    test_file(fs, new, test);   /* Bad cluster check */
}

static int subdirs(DOS_FS * fs, DOS_FILE * parent, FDSC ** cp);

static int scan_dir(DOS_FS * fs, DOS_FILE * this, FDSC ** cp)
{
    DOS_FILE **chain;
    int i;
    uint32_t clu_num;

    chain = &this->first;
    i = 0;
    clu_num = FSTART(this, fs);
    new_dir();
    while (clu_num > 0 && clu_num != -1) {
    add_file(fs, &chain, this,
         cluster_start(fs, clu_num) + (i % fs->cluster_size), cp);
    i += sizeof(DIR_ENT);
    if (!(i % fs->cluster_size))
        if ((clu_num = next_cluster(fs, clu_num)) == 0 || clu_num == -1)
        break;
    }
    lfn_check_orphaned();
    if (check_dir(fs, &this->first, this->offset))
    return 0;
    if (check_files(fs, this->first))
    return 1;
    return subdirs(fs, this, cp);
}

static int subdirs(DOS_FS * fs, DOS_FILE * parent, FDSC ** cp)
{
    DOS_FILE *walk;

    for (walk = parent ? parent->first : root; walk; walk = walk->next)
    if (walk->dir_ent.attr & ATTR_DIR)
        if (strncmp((const char *)walk->dir_ent.name, MSDOS_DOT, MSDOS_NAME)
        && strncmp((const char *)walk->dir_ent.name, MSDOS_DOTDOT,
               MSDOS_NAME))
        if (scan_dir(fs, walk, file_cd(cp, (char *)walk->dir_ent.name)))
            return 1;
    return 0;
}

int scan_root(DOS_FS * fs)
{
    DOS_FILE **chain;
    int i;

    root = NULL;
    chain = &root;
    new_dir();
    if (fs->root_cluster) {
    add_file(fs, &chain, NULL, 0, &fp_root);
    } else {
    for (i = 0; i < fs->root_entries; i++)
        add_file(fs, &chain, NULL, fs->root_start + i * sizeof(DIR_ENT),
             &fp_root);
    }
    lfn_check_orphaned();
    (void)check_dir(fs, &root, 0);
    if (check_files(fs, root))
    return 1;
    return subdirs(fs, NULL, &fp_root);
}