linux/fs/fat/dir.c
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   1/*
   2 *  linux/fs/fat/dir.c
   3 *
   4 *  directory handling functions for fat-based filesystems
   5 *
   6 *  Written 1992,1993 by Werner Almesberger
   7 *
   8 *  Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
   9 *
  10 *  VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu>
  11 *  Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk>
  12 *  Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
  13 *  Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
  14 */
  15
  16#include <linux/module.h>
  17#include <linux/slab.h>
  18#include <linux/time.h>
  19#include <linux/buffer_head.h>
  20#include <linux/compat.h>
  21#include <asm/uaccess.h>
  22#include <linux/kernel.h>
  23#include "fat.h"
  24
  25/*
  26 * Maximum buffer size of short name.
  27 * [(MSDOS_NAME + '.') * max one char + nul]
  28 * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
  29 */
  30#define FAT_MAX_SHORT_SIZE      ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
  31/*
  32 * Maximum buffer size of unicode chars from slots.
  33 * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
  34 */
  35#define FAT_MAX_UNI_CHARS       ((MSDOS_SLOTS - 1) * 13 + 1)
  36#define FAT_MAX_UNI_SIZE        (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
  37
  38static inline unsigned char fat_tolower(unsigned char c)
  39{
  40        return ((c >= 'A') && (c <= 'Z')) ? c+32 : c;
  41}
  42
  43static inline loff_t fat_make_i_pos(struct super_block *sb,
  44                                    struct buffer_head *bh,
  45                                    struct msdos_dir_entry *de)
  46{
  47        return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
  48                | (de - (struct msdos_dir_entry *)bh->b_data);
  49}
  50
  51static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
  52                                     sector_t phys)
  53{
  54        struct super_block *sb = dir->i_sb;
  55        struct msdos_sb_info *sbi = MSDOS_SB(sb);
  56        struct buffer_head *bh;
  57        int sec;
  58
  59        /* This is not a first sector of cluster, or sec_per_clus == 1 */
  60        if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
  61                return;
  62        /* root dir of FAT12/FAT16 */
  63        if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
  64                return;
  65
  66        bh = sb_find_get_block(sb, phys);
  67        if (bh == NULL || !buffer_uptodate(bh)) {
  68                for (sec = 0; sec < sbi->sec_per_clus; sec++)
  69                        sb_breadahead(sb, phys + sec);
  70        }
  71        brelse(bh);
  72}
  73
  74/* Returns the inode number of the directory entry at offset pos. If bh is
  75   non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
  76   returned in bh.
  77   AV. Most often we do it item-by-item. Makes sense to optimize.
  78   AV. OK, there we go: if both bh and de are non-NULL we assume that we just
  79   AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
  80   AV. It's done in fat_get_entry() (inlined), here the slow case lives.
  81   AV. Additionally, when we return -1 (i.e. reached the end of directory)
  82   AV. we make bh NULL.
  83 */
  84static int fat__get_entry(struct inode *dir, loff_t *pos,
  85                          struct buffer_head **bh, struct msdos_dir_entry **de)
  86{
  87        struct super_block *sb = dir->i_sb;
  88        sector_t phys, iblock;
  89        unsigned long mapped_blocks;
  90        int err, offset;
  91
  92next:
  93        if (*bh)
  94                brelse(*bh);
  95
  96        *bh = NULL;
  97        iblock = *pos >> sb->s_blocksize_bits;
  98        err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0);
  99        if (err || !phys)
 100                return -1;      /* beyond EOF or error */
 101
 102        fat_dir_readahead(dir, iblock, phys);
 103
 104        *bh = sb_bread(sb, phys);
 105        if (*bh == NULL) {
 106                fat_msg_ratelimit(sb, KERN_ERR,
 107                        "Directory bread(block %llu) failed", (llu)phys);
 108                /* skip this block */
 109                *pos = (iblock + 1) << sb->s_blocksize_bits;
 110                goto next;
 111        }
 112
 113        offset = *pos & (sb->s_blocksize - 1);
 114        *pos += sizeof(struct msdos_dir_entry);
 115        *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
 116
 117        return 0;
 118}
 119
 120static inline int fat_get_entry(struct inode *dir, loff_t *pos,
 121                                struct buffer_head **bh,
 122                                struct msdos_dir_entry **de)
 123{
 124        /* Fast stuff first */
 125        if (*bh && *de &&
 126            (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
 127                *pos += sizeof(struct msdos_dir_entry);
 128                (*de)++;
 129                return 0;
 130        }
 131        return fat__get_entry(dir, pos, bh, de);
 132}
 133
 134/*
 135 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
 136 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
 137 * colon as an escape character since it is normally invalid on the vfat
 138 * filesystem. The following four characters are the hexadecimal digits
 139 * of Unicode value. This lets us do a full dump and restore of Unicode
 140 * filenames. We could get into some trouble with long Unicode names,
 141 * but ignore that right now.
 142 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
 143 */
 144static int uni16_to_x8(struct super_block *sb, unsigned char *ascii,
 145                       const wchar_t *uni, int len, struct nls_table *nls)
 146{
 147        int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate;
 148        const wchar_t *ip;
 149        wchar_t ec;
 150        unsigned char *op;
 151        int charlen;
 152
 153        ip = uni;
 154        op = ascii;
 155
 156        while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) {
 157                ec = *ip++;
 158                if ((charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
 159                        op += charlen;
 160                        len -= charlen;
 161                } else {
 162                        if (uni_xlate == 1) {
 163                                *op++ = ':';
 164                                op = hex_byte_pack(op, ec >> 8);
 165                                op = hex_byte_pack(op, ec);
 166                                len -= 5;
 167                        } else {
 168                                *op++ = '?';
 169                                len--;
 170                        }
 171                }
 172        }
 173
 174        if (unlikely(*ip)) {
 175                fat_msg(sb, KERN_WARNING, "filename was truncated while "
 176                        "converting.");
 177        }
 178
 179        *op = 0;
 180        return (op - ascii);
 181}
 182
 183static inline int fat_uni_to_x8(struct super_block *sb, const wchar_t *uni,
 184                                unsigned char *buf, int size)
 185{
 186        struct msdos_sb_info *sbi = MSDOS_SB(sb);
 187        if (sbi->options.utf8)
 188                return utf16s_to_utf8s(uni, FAT_MAX_UNI_CHARS,
 189                                UTF16_HOST_ENDIAN, buf, size);
 190        else
 191                return uni16_to_x8(sb, buf, uni, size, sbi->nls_io);
 192}
 193
 194static inline int
 195fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
 196{
 197        int charlen;
 198
 199        charlen = t->char2uni(c, clen, uni);
 200        if (charlen < 0) {
 201                *uni = 0x003f;  /* a question mark */
 202                charlen = 1;
 203        }
 204        return charlen;
 205}
 206
 207static inline int
 208fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
 209{
 210        int charlen;
 211        wchar_t wc;
 212
 213        charlen = t->char2uni(c, clen, &wc);
 214        if (charlen < 0) {
 215                *uni = 0x003f;  /* a question mark */
 216                charlen = 1;
 217        } else if (charlen <= 1) {
 218                unsigned char nc = t->charset2lower[*c];
 219
 220                if (!nc)
 221                        nc = *c;
 222
 223                if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
 224                        *uni = 0x003f;  /* a question mark */
 225                        charlen = 1;
 226                }
 227        } else
 228                *uni = wc;
 229
 230        return charlen;
 231}
 232
 233static inline int
 234fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
 235                  wchar_t *uni_buf, unsigned short opt, int lower)
 236{
 237        int len = 0;
 238
 239        if (opt & VFAT_SFN_DISPLAY_LOWER)
 240                len =  fat_short2lower_uni(nls, buf, buf_size, uni_buf);
 241        else if (opt & VFAT_SFN_DISPLAY_WIN95)
 242                len = fat_short2uni(nls, buf, buf_size, uni_buf);
 243        else if (opt & VFAT_SFN_DISPLAY_WINNT) {
 244                if (lower)
 245                        len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
 246                else
 247                        len = fat_short2uni(nls, buf, buf_size, uni_buf);
 248        } else
 249                len = fat_short2uni(nls, buf, buf_size, uni_buf);
 250
 251        return len;
 252}
 253
 254static inline int fat_name_match(struct msdos_sb_info *sbi,
 255                                 const unsigned char *a, int a_len,
 256                                 const unsigned char *b, int b_len)
 257{
 258        if (a_len != b_len)
 259                return 0;
 260
 261        if (sbi->options.name_check != 's')
 262                return !nls_strnicmp(sbi->nls_io, a, b, a_len);
 263        else
 264                return !memcmp(a, b, a_len);
 265}
 266
 267enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
 268
 269/**
 270 * fat_parse_long - Parse extended directory entry.
 271 *
 272 * This function returns zero on success, negative value on error, or one of
 273 * the following:
 274 *
 275 * %PARSE_INVALID - Directory entry is invalid.
 276 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
 277 * %PARSE_EOF - Directory has no more entries.
 278 */
 279static int fat_parse_long(struct inode *dir, loff_t *pos,
 280                          struct buffer_head **bh, struct msdos_dir_entry **de,
 281                          wchar_t **unicode, unsigned char *nr_slots)
 282{
 283        struct msdos_dir_slot *ds;
 284        unsigned char id, slot, slots, alias_checksum;
 285
 286        if (!*unicode) {
 287                *unicode = __getname();
 288                if (!*unicode) {
 289                        brelse(*bh);
 290                        return -ENOMEM;
 291                }
 292        }
 293parse_long:
 294        slots = 0;
 295        ds = (struct msdos_dir_slot *)*de;
 296        id = ds->id;
 297        if (!(id & 0x40))
 298                return PARSE_INVALID;
 299        slots = id & ~0x40;
 300        if (slots > 20 || !slots)       /* ceil(256 * 2 / 26) */
 301                return PARSE_INVALID;
 302        *nr_slots = slots;
 303        alias_checksum = ds->alias_checksum;
 304
 305        slot = slots;
 306        while (1) {
 307                int offset;
 308
 309                slot--;
 310                offset = slot * 13;
 311                fat16_towchar(*unicode + offset, ds->name0_4, 5);
 312                fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
 313                fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
 314
 315                if (ds->id & 0x40)
 316                        (*unicode)[offset + 13] = 0;
 317                if (fat_get_entry(dir, pos, bh, de) < 0)
 318                        return PARSE_EOF;
 319                if (slot == 0)
 320                        break;
 321                ds = (struct msdos_dir_slot *)*de;
 322                if (ds->attr != ATTR_EXT)
 323                        return PARSE_NOT_LONGNAME;
 324                if ((ds->id & ~0x40) != slot)
 325                        goto parse_long;
 326                if (ds->alias_checksum != alias_checksum)
 327                        goto parse_long;
 328        }
 329        if ((*de)->name[0] == DELETED_FLAG)
 330                return PARSE_INVALID;
 331        if ((*de)->attr == ATTR_EXT)
 332                goto parse_long;
 333        if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
 334                return PARSE_INVALID;
 335        if (fat_checksum((*de)->name) != alias_checksum)
 336                *nr_slots = 0;
 337
 338        return 0;
 339}
 340
 341/**
 342 * fat_parse_short - Parse MS-DOS (short) directory entry.
 343 * @sb:         superblock
 344 * @de:         directory entry to parse
 345 * @name:       FAT_MAX_SHORT_SIZE array in which to place extracted name
 346 * @dot_hidden: Nonzero == prepend '.' to names with ATTR_HIDDEN
 347 *
 348 * Returns the number of characters extracted into 'name'.
 349 */
 350static int fat_parse_short(struct super_block *sb,
 351                           const struct msdos_dir_entry *de,
 352                           unsigned char *name, int dot_hidden)
 353{
 354        const struct msdos_sb_info *sbi = MSDOS_SB(sb);
 355        int isvfat = sbi->options.isvfat;
 356        int nocase = sbi->options.nocase;
 357        unsigned short opt_shortname = sbi->options.shortname;
 358        struct nls_table *nls_disk = sbi->nls_disk;
 359        wchar_t uni_name[14];
 360        unsigned char c, work[MSDOS_NAME];
 361        unsigned char *ptname = name;
 362        int chi, chl, i, j, k;
 363        int dotoffset = 0;
 364        int name_len = 0, uni_len = 0;
 365
 366        if (!isvfat && dot_hidden && (de->attr & ATTR_HIDDEN)) {
 367                *ptname++ = '.';
 368                dotoffset = 1;
 369        }
 370
 371        memcpy(work, de->name, sizeof(work));
 372        /* see namei.c, msdos_format_name */
 373        if (work[0] == 0x05)
 374                work[0] = 0xE5;
 375
 376        /* Filename */
 377        for (i = 0, j = 0; i < 8;) {
 378                c = work[i];
 379                if (!c)
 380                        break;
 381                chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
 382                                        &uni_name[j++], opt_shortname,
 383                                        de->lcase & CASE_LOWER_BASE);
 384                if (chl <= 1) {
 385                        if (!isvfat)
 386                                ptname[i] = nocase ? c : fat_tolower(c);
 387                        i++;
 388                        if (c != ' ') {
 389                                name_len = i;
 390                                uni_len  = j;
 391                        }
 392                } else {
 393                        uni_len = j;
 394                        if (isvfat)
 395                                i += min(chl, 8-i);
 396                        else {
 397                                for (chi = 0; chi < chl && i < 8; chi++, i++)
 398                                        ptname[i] = work[i];
 399                        }
 400                        if (chl)
 401                                name_len = i;
 402                }
 403        }
 404
 405        i = name_len;
 406        j = uni_len;
 407        fat_short2uni(nls_disk, ".", 1, &uni_name[j++]);
 408        if (!isvfat)
 409                ptname[i] = '.';
 410        i++;
 411
 412        /* Extension */
 413        for (k = 8; k < MSDOS_NAME;) {
 414                c = work[k];
 415                if (!c)
 416                        break;
 417                chl = fat_shortname2uni(nls_disk, &work[k], MSDOS_NAME - k,
 418                                        &uni_name[j++], opt_shortname,
 419                                        de->lcase & CASE_LOWER_EXT);
 420                if (chl <= 1) {
 421                        k++;
 422                        if (!isvfat)
 423                                ptname[i] = nocase ? c : fat_tolower(c);
 424                        i++;
 425                        if (c != ' ') {
 426                                name_len = i;
 427                                uni_len  = j;
 428                        }
 429                } else {
 430                        uni_len = j;
 431                        if (isvfat) {
 432                                int offset = min(chl, MSDOS_NAME-k);
 433                                k += offset;
 434                                i += offset;
 435                        } else {
 436                                for (chi = 0; chi < chl && k < MSDOS_NAME;
 437                                     chi++, i++, k++) {
 438                                                ptname[i] = work[k];
 439                                }
 440                        }
 441                        if (chl)
 442                                name_len = i;
 443                }
 444        }
 445
 446        if (name_len > 0) {
 447                name_len += dotoffset;
 448
 449                if (sbi->options.isvfat) {
 450                        uni_name[uni_len] = 0x0000;
 451                        name_len = fat_uni_to_x8(sb, uni_name, name,
 452                                                 FAT_MAX_SHORT_SIZE);
 453                }
 454        }
 455
 456        return name_len;
 457}
 458
 459/*
 460 * Return values: negative -> error, 0 -> not found, positive -> found,
 461 * value is the total amount of slots, including the shortname entry.
 462 */
 463int fat_search_long(struct inode *inode, const unsigned char *name,
 464                    int name_len, struct fat_slot_info *sinfo)
 465{
 466        struct super_block *sb = inode->i_sb;
 467        struct msdos_sb_info *sbi = MSDOS_SB(sb);
 468        struct buffer_head *bh = NULL;
 469        struct msdos_dir_entry *de;
 470        unsigned char nr_slots;
 471        wchar_t *unicode = NULL;
 472        unsigned char bufname[FAT_MAX_SHORT_SIZE];
 473        loff_t cpos = 0;
 474        int err, len;
 475
 476        err = -ENOENT;
 477        while (1) {
 478                if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
 479                        goto end_of_dir;
 480parse_record:
 481                nr_slots = 0;
 482                if (de->name[0] == DELETED_FLAG)
 483                        continue;
 484                if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
 485                        continue;
 486                if (de->attr != ATTR_EXT && IS_FREE(de->name))
 487                        continue;
 488                if (de->attr == ATTR_EXT) {
 489                        int status = fat_parse_long(inode, &cpos, &bh, &de,
 490                                                    &unicode, &nr_slots);
 491                        if (status < 0) {
 492                                err = status;
 493                                goto end_of_dir;
 494                        } else if (status == PARSE_INVALID)
 495                                continue;
 496                        else if (status == PARSE_NOT_LONGNAME)
 497                                goto parse_record;
 498                        else if (status == PARSE_EOF)
 499                                goto end_of_dir;
 500                }
 501
 502                /* Never prepend '.' to hidden files here.
 503                 * That is done only for msdos mounts (and only when
 504                 * 'dotsOK=yes'); if we are executing here, it is in the
 505                 * context of a vfat mount.
 506                 */
 507                len = fat_parse_short(sb, de, bufname, 0);
 508                if (len == 0)
 509                        continue;
 510
 511                /* Compare shortname */
 512                if (fat_name_match(sbi, name, name_len, bufname, len))
 513                        goto found;
 514
 515                if (nr_slots) {
 516                        void *longname = unicode + FAT_MAX_UNI_CHARS;
 517                        int size = PATH_MAX - FAT_MAX_UNI_SIZE;
 518
 519                        /* Compare longname */
 520                        len = fat_uni_to_x8(sb, unicode, longname, size);
 521                        if (fat_name_match(sbi, name, name_len, longname, len))
 522                                goto found;
 523                }
 524        }
 525
 526found:
 527        nr_slots++;     /* include the de */
 528        sinfo->slot_off = cpos - nr_slots * sizeof(*de);
 529        sinfo->nr_slots = nr_slots;
 530        sinfo->de = de;
 531        sinfo->bh = bh;
 532        sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
 533        err = 0;
 534end_of_dir:
 535        if (unicode)
 536                __putname(unicode);
 537
 538        return err;
 539}
 540
 541EXPORT_SYMBOL_GPL(fat_search_long);
 542
 543struct fat_ioctl_filldir_callback {
 544        void __user *dirent;
 545        int result;
 546        /* for dir ioctl */
 547        const char *longname;
 548        int long_len;
 549        const char *shortname;
 550        int short_len;
 551};
 552
 553static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
 554                         filldir_t filldir, int short_only, int both)
 555{
 556        struct super_block *sb = inode->i_sb;
 557        struct msdos_sb_info *sbi = MSDOS_SB(sb);
 558        struct buffer_head *bh;
 559        struct msdos_dir_entry *de;
 560        unsigned char nr_slots;
 561        wchar_t *unicode = NULL;
 562        unsigned char bufname[FAT_MAX_SHORT_SIZE];
 563        int isvfat = sbi->options.isvfat;
 564        const char *fill_name = NULL;
 565        unsigned long inum;
 566        unsigned long lpos, dummy, *furrfu = &lpos;
 567        loff_t cpos;
 568        int short_len = 0, fill_len = 0;
 569        int ret = 0;
 570
 571        lock_super(sb);
 572
 573        cpos = filp->f_pos;
 574        /* Fake . and .. for the root directory. */
 575        if (inode->i_ino == MSDOS_ROOT_INO) {
 576                while (cpos < 2) {
 577                        if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
 578                                goto out;
 579                        cpos++;
 580                        filp->f_pos++;
 581                }
 582                if (cpos == 2) {
 583                        dummy = 2;
 584                        furrfu = &dummy;
 585                        cpos = 0;
 586                }
 587        }
 588        if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
 589                ret = -ENOENT;
 590                goto out;
 591        }
 592
 593        bh = NULL;
 594get_new:
 595        if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
 596                goto end_of_dir;
 597parse_record:
 598        nr_slots = 0;
 599        /*
 600         * Check for long filename entry, but if short_only, we don't
 601         * need to parse long filename.
 602         */
 603        if (isvfat && !short_only) {
 604                if (de->name[0] == DELETED_FLAG)
 605                        goto record_end;
 606                if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
 607                        goto record_end;
 608                if (de->attr != ATTR_EXT && IS_FREE(de->name))
 609                        goto record_end;
 610        } else {
 611                if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
 612                        goto record_end;
 613        }
 614
 615        if (isvfat && de->attr == ATTR_EXT) {
 616                int status = fat_parse_long(inode, &cpos, &bh, &de,
 617                                            &unicode, &nr_slots);
 618                if (status < 0) {
 619                        filp->f_pos = cpos;
 620                        ret = status;
 621                        goto out;
 622                } else if (status == PARSE_INVALID)
 623                        goto record_end;
 624                else if (status == PARSE_NOT_LONGNAME)
 625                        goto parse_record;
 626                else if (status == PARSE_EOF)
 627                        goto end_of_dir;
 628
 629                if (nr_slots) {
 630                        void *longname = unicode + FAT_MAX_UNI_CHARS;
 631                        int size = PATH_MAX - FAT_MAX_UNI_SIZE;
 632                        int len = fat_uni_to_x8(sb, unicode, longname, size);
 633
 634                        fill_name = longname;
 635                        fill_len = len;
 636                        /* !both && !short_only, so we don't need shortname. */
 637                        if (!both)
 638                                goto start_filldir;
 639                }
 640        }
 641
 642        short_len = fat_parse_short(sb, de, bufname, sbi->options.dotsOK);
 643        if (short_len == 0)
 644                goto record_end;
 645
 646        if (nr_slots) {
 647                /* hack for fat_ioctl_filldir() */
 648                struct fat_ioctl_filldir_callback *p = dirent;
 649
 650                p->longname = fill_name;
 651                p->long_len = fill_len;
 652                p->shortname = bufname;
 653                p->short_len = short_len;
 654                fill_name = NULL;
 655                fill_len = 0;
 656        } else {
 657                fill_name = bufname;
 658                fill_len = short_len;
 659        }
 660
 661start_filldir:
 662        lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
 663        if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
 664                inum = inode->i_ino;
 665        else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 666                inum = parent_ino(filp->f_path.dentry);
 667        } else {
 668                loff_t i_pos = fat_make_i_pos(sb, bh, de);
 669                struct inode *tmp = fat_iget(sb, i_pos);
 670                if (tmp) {
 671                        inum = tmp->i_ino;
 672                        iput(tmp);
 673                } else
 674                        inum = iunique(sb, MSDOS_ROOT_INO);
 675        }
 676
 677        if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
 678                    (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
 679                goto fill_failed;
 680
 681record_end:
 682        furrfu = &lpos;
 683        filp->f_pos = cpos;
 684        goto get_new;
 685end_of_dir:
 686        filp->f_pos = cpos;
 687fill_failed:
 688        brelse(bh);
 689        if (unicode)
 690                __putname(unicode);
 691out:
 692        unlock_super(sb);
 693        return ret;
 694}
 695
 696static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
 697{
 698        struct inode *inode = filp->f_path.dentry->d_inode;
 699        return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
 700}
 701
 702#define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type)                          \
 703static int func(void *__buf, const char *name, int name_len,               \
 704                             loff_t offset, u64 ino, unsigned int d_type)  \
 705{                                                                          \
 706        struct fat_ioctl_filldir_callback *buf = __buf;                    \
 707        struct dirent_type __user *d1 = buf->dirent;                       \
 708        struct dirent_type __user *d2 = d1 + 1;                            \
 709                                                                           \
 710        if (buf->result)                                                   \
 711                return -EINVAL;                                            \
 712        buf->result++;                                                     \
 713                                                                           \
 714        if (name != NULL) {                                                \
 715                /* dirent has only short name */                           \
 716                if (name_len >= sizeof(d1->d_name))                        \
 717                        name_len = sizeof(d1->d_name) - 1;                 \
 718                                                                           \
 719                if (put_user(0, d2->d_name)                     ||         \
 720                    put_user(0, &d2->d_reclen)                  ||         \
 721                    copy_to_user(d1->d_name, name, name_len)    ||         \
 722                    put_user(0, d1->d_name + name_len)          ||         \
 723                    put_user(name_len, &d1->d_reclen))                     \
 724                        goto efault;                                       \
 725        } else {                                                           \
 726                /* dirent has short and long name */                       \
 727                const char *longname = buf->longname;                      \
 728                int long_len = buf->long_len;                              \
 729                const char *shortname = buf->shortname;                    \
 730                int short_len = buf->short_len;                            \
 731                                                                           \
 732                if (long_len >= sizeof(d1->d_name))                        \
 733                        long_len = sizeof(d1->d_name) - 1;                 \
 734                if (short_len >= sizeof(d1->d_name))                       \
 735                        short_len = sizeof(d1->d_name) - 1;                \
 736                                                                           \
 737                if (copy_to_user(d2->d_name, longname, long_len)        || \
 738                    put_user(0, d2->d_name + long_len)                  || \
 739                    put_user(long_len, &d2->d_reclen)                   || \
 740                    put_user(ino, &d2->d_ino)                           || \
 741                    put_user(offset, &d2->d_off)                        || \
 742                    copy_to_user(d1->d_name, shortname, short_len)      || \
 743                    put_user(0, d1->d_name + short_len)                 || \
 744                    put_user(short_len, &d1->d_reclen))                    \
 745                        goto efault;                                       \
 746        }                                                                  \
 747        return 0;                                                          \
 748efault:                                                                    \
 749        buf->result = -EFAULT;                                             \
 750        return -EFAULT;                                                    \
 751}
 752
 753FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
 754
 755static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
 756                             void __user *dirent, filldir_t filldir,
 757                             int short_only, int both)
 758{
 759        struct fat_ioctl_filldir_callback buf;
 760        int ret;
 761
 762        buf.dirent = dirent;
 763        buf.result = 0;
 764        mutex_lock(&inode->i_mutex);
 765        ret = -ENOENT;
 766        if (!IS_DEADDIR(inode)) {
 767                ret = __fat_readdir(inode, filp, &buf, filldir,
 768                                    short_only, both);
 769        }
 770        mutex_unlock(&inode->i_mutex);
 771        if (ret >= 0)
 772                ret = buf.result;
 773        return ret;
 774}
 775
 776static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
 777                          unsigned long arg)
 778{
 779        struct inode *inode = filp->f_path.dentry->d_inode;
 780        struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
 781        int short_only, both;
 782
 783        switch (cmd) {
 784        case VFAT_IOCTL_READDIR_SHORT:
 785                short_only = 1;
 786                both = 0;
 787                break;
 788        case VFAT_IOCTL_READDIR_BOTH:
 789                short_only = 0;
 790                both = 1;
 791                break;
 792        default:
 793                return fat_generic_ioctl(filp, cmd, arg);
 794        }
 795
 796        if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2])))
 797                return -EFAULT;
 798        /*
 799         * Yes, we don't need this put_user() absolutely. However old
 800         * code didn't return the right value. So, app use this value,
 801         * in order to check whether it is EOF.
 802         */
 803        if (put_user(0, &d1->d_reclen))
 804                return -EFAULT;
 805
 806        return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
 807                                 short_only, both);
 808}
 809
 810#ifdef CONFIG_COMPAT
 811#define VFAT_IOCTL_READDIR_BOTH32       _IOR('r', 1, struct compat_dirent[2])
 812#define VFAT_IOCTL_READDIR_SHORT32      _IOR('r', 2, struct compat_dirent[2])
 813
 814FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
 815
 816static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
 817                                 unsigned long arg)
 818{
 819        struct inode *inode = filp->f_path.dentry->d_inode;
 820        struct compat_dirent __user *d1 = compat_ptr(arg);
 821        int short_only, both;
 822
 823        switch (cmd) {
 824        case VFAT_IOCTL_READDIR_SHORT32:
 825                short_only = 1;
 826                both = 0;
 827                break;
 828        case VFAT_IOCTL_READDIR_BOTH32:
 829                short_only = 0;
 830                both = 1;
 831                break;
 832        default:
 833                return fat_generic_ioctl(filp, cmd, (unsigned long)arg);
 834        }
 835
 836        if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
 837                return -EFAULT;
 838        /*
 839         * Yes, we don't need this put_user() absolutely. However old
 840         * code didn't return the right value. So, app use this value,
 841         * in order to check whether it is EOF.
 842         */
 843        if (put_user(0, &d1->d_reclen))
 844                return -EFAULT;
 845
 846        return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
 847                                 short_only, both);
 848}
 849#endif /* CONFIG_COMPAT */
 850
 851const struct file_operations fat_dir_operations = {
 852        .llseek         = generic_file_llseek,
 853        .read           = generic_read_dir,
 854        .readdir        = fat_readdir,
 855        .unlocked_ioctl = fat_dir_ioctl,
 856#ifdef CONFIG_COMPAT
 857        .compat_ioctl   = fat_compat_dir_ioctl,
 858#endif
 859        .fsync          = fat_file_fsync,
 860};
 861
 862static int fat_get_short_entry(struct inode *dir, loff_t *pos,
 863                               struct buffer_head **bh,
 864                               struct msdos_dir_entry **de)
 865{
 866        while (fat_get_entry(dir, pos, bh, de) >= 0) {
 867                /* free entry or long name entry or volume label */
 868                if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
 869                        return 0;
 870        }
 871        return -ENOENT;
 872}
 873
 874/*
 875 * The ".." entry can not provide the "struct fat_slot_info" informations
 876 * for inode. So, this function provide the some informations only.
 877 */
 878int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
 879                         struct msdos_dir_entry **de, loff_t *i_pos)
 880{
 881        loff_t offset;
 882
 883        offset = 0;
 884        *bh = NULL;
 885        while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
 886                if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 887                        *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
 888                        return 0;
 889                }
 890        }
 891        return -ENOENT;
 892}
 893
 894EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
 895
 896/* See if directory is empty */
 897int fat_dir_empty(struct inode *dir)
 898{
 899        struct buffer_head *bh;
 900        struct msdos_dir_entry *de;
 901        loff_t cpos;
 902        int result = 0;
 903
 904        bh = NULL;
 905        cpos = 0;
 906        while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
 907                if (strncmp(de->name, MSDOS_DOT   , MSDOS_NAME) &&
 908                    strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 909                        result = -ENOTEMPTY;
 910                        break;
 911                }
 912        }
 913        brelse(bh);
 914        return result;
 915}
 916
 917EXPORT_SYMBOL_GPL(fat_dir_empty);
 918
 919/*
 920 * fat_subdirs counts the number of sub-directories of dir. It can be run
 921 * on directories being created.
 922 */
 923int fat_subdirs(struct inode *dir)
 924{
 925        struct buffer_head *bh;
 926        struct msdos_dir_entry *de;
 927        loff_t cpos;
 928        int count = 0;
 929
 930        bh = NULL;
 931        cpos = 0;
 932        while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
 933                if (de->attr & ATTR_DIR)
 934                        count++;
 935        }
 936        brelse(bh);
 937        return count;
 938}
 939
 940/*
 941 * Scans a directory for a given file (name points to its formatted name).
 942 * Returns an error code or zero.
 943 */
 944int fat_scan(struct inode *dir, const unsigned char *name,
 945             struct fat_slot_info *sinfo)
 946{
 947        struct super_block *sb = dir->i_sb;
 948
 949        sinfo->slot_off = 0;
 950        sinfo->bh = NULL;
 951        while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
 952                                   &sinfo->de) >= 0) {
 953                if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
 954                        sinfo->slot_off -= sizeof(*sinfo->de);
 955                        sinfo->nr_slots = 1;
 956                        sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
 957                        return 0;
 958                }
 959        }
 960        return -ENOENT;
 961}
 962
 963EXPORT_SYMBOL_GPL(fat_scan);
 964
 965static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
 966{
 967        struct super_block *sb = dir->i_sb;
 968        struct buffer_head *bh;
 969        struct msdos_dir_entry *de, *endp;
 970        int err = 0, orig_slots;
 971
 972        while (nr_slots) {
 973                bh = NULL;
 974                if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
 975                        err = -EIO;
 976                        break;
 977                }
 978
 979                orig_slots = nr_slots;
 980                endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
 981                while (nr_slots && de < endp) {
 982                        de->name[0] = DELETED_FLAG;
 983                        de++;
 984                        nr_slots--;
 985                }
 986                mark_buffer_dirty_inode(bh, dir);
 987                if (IS_DIRSYNC(dir))
 988                        err = sync_dirty_buffer(bh);
 989                brelse(bh);
 990                if (err)
 991                        break;
 992
 993                /* pos is *next* de's position, so this does `- sizeof(de)' */
 994                pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
 995        }
 996
 997        return err;
 998}
 999
1000int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
1001{
1002        struct super_block *sb = dir->i_sb;
1003        struct msdos_dir_entry *de;
1004        struct buffer_head *bh;
1005        int err = 0, nr_slots;
1006
1007        /*
1008         * First stage: Remove the shortname. By this, the directory
1009         * entry is removed.
1010         */
1011        nr_slots = sinfo->nr_slots;
1012        de = sinfo->de;
1013        sinfo->de = NULL;
1014        bh = sinfo->bh;
1015        sinfo->bh = NULL;
1016        while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
1017                de->name[0] = DELETED_FLAG;
1018                de--;
1019                nr_slots--;
1020        }
1021        mark_buffer_dirty_inode(bh, dir);
1022        if (IS_DIRSYNC(dir))
1023                err = sync_dirty_buffer(bh);
1024        brelse(bh);
1025        if (err)
1026                return err;
1027        dir->i_version++;
1028
1029        if (nr_slots) {
1030                /*
1031                 * Second stage: remove the remaining longname slots.
1032                 * (This directory entry is already removed, and so return
1033                 * the success)
1034                 */
1035                err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
1036                if (err) {
1037                        fat_msg(sb, KERN_WARNING,
1038                               "Couldn't remove the long name slots");
1039                }
1040        }
1041
1042        dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
1043        if (IS_DIRSYNC(dir))
1044                (void)fat_sync_inode(dir);
1045        else
1046                mark_inode_dirty(dir);
1047
1048        return 0;
1049}
1050
1051EXPORT_SYMBOL_GPL(fat_remove_entries);
1052
1053static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1054                              struct buffer_head **bhs, int nr_bhs)
1055{
1056        struct super_block *sb = dir->i_sb;
1057        sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1058        int err, i, n;
1059
1060        /* Zeroing the unused blocks on this cluster */
1061        blknr += nr_used;
1062        n = nr_used;
1063        while (blknr < last_blknr) {
1064                bhs[n] = sb_getblk(sb, blknr);
1065                if (!bhs[n]) {
1066                        err = -ENOMEM;
1067                        goto error;
1068                }
1069                memset(bhs[n]->b_data, 0, sb->s_blocksize);
1070                set_buffer_uptodate(bhs[n]);
1071                mark_buffer_dirty_inode(bhs[n], dir);
1072
1073                n++;
1074                blknr++;
1075                if (n == nr_bhs) {
1076                        if (IS_DIRSYNC(dir)) {
1077                                err = fat_sync_bhs(bhs, n);
1078                                if (err)
1079                                        goto error;
1080                        }
1081                        for (i = 0; i < n; i++)
1082                                brelse(bhs[i]);
1083                        n = 0;
1084                }
1085        }
1086        if (IS_DIRSYNC(dir)) {
1087                err = fat_sync_bhs(bhs, n);
1088                if (err)
1089                        goto error;
1090        }
1091        for (i = 0; i < n; i++)
1092                brelse(bhs[i]);
1093
1094        return 0;
1095
1096error:
1097        for (i = 0; i < n; i++)
1098                bforget(bhs[i]);
1099        return err;
1100}
1101
1102int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1103{
1104        struct super_block *sb = dir->i_sb;
1105        struct msdos_sb_info *sbi = MSDOS_SB(sb);
1106        struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1107        struct msdos_dir_entry *de;
1108        sector_t blknr;
1109        __le16 date, time;
1110        u8 time_cs;
1111        int err, cluster;
1112
1113        err = fat_alloc_clusters(dir, &cluster, 1);
1114        if (err)
1115                goto error;
1116
1117        blknr = fat_clus_to_blknr(sbi, cluster);
1118        bhs[0] = sb_getblk(sb, blknr);
1119        if (!bhs[0]) {
1120                err = -ENOMEM;
1121                goto error_free;
1122        }
1123
1124        fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
1125
1126        de = (struct msdos_dir_entry *)bhs[0]->b_data;
1127        /* filling the new directory slots ("." and ".." entries) */
1128        memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1129        memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1130        de->attr = de[1].attr = ATTR_DIR;
1131        de[0].lcase = de[1].lcase = 0;
1132        de[0].time = de[1].time = time;
1133        de[0].date = de[1].date = date;
1134        if (sbi->options.isvfat) {
1135                /* extra timestamps */
1136                de[0].ctime = de[1].ctime = time;
1137                de[0].ctime_cs = de[1].ctime_cs = time_cs;
1138                de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1139        } else {
1140                de[0].ctime = de[1].ctime = 0;
1141                de[0].ctime_cs = de[1].ctime_cs = 0;
1142                de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1143        }
1144        de[0].start = cpu_to_le16(cluster);
1145        de[0].starthi = cpu_to_le16(cluster >> 16);
1146        de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
1147        de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
1148        de[0].size = de[1].size = 0;
1149        memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1150        set_buffer_uptodate(bhs[0]);
1151        mark_buffer_dirty_inode(bhs[0], dir);
1152
1153        err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1154        if (err)
1155                goto error_free;
1156
1157        return cluster;
1158
1159error_free:
1160        fat_free_clusters(dir, cluster);
1161error:
1162        return err;
1163}
1164
1165EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1166
1167static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1168                               int *nr_cluster, struct msdos_dir_entry **de,
1169                               struct buffer_head **bh, loff_t *i_pos)
1170{
1171        struct super_block *sb = dir->i_sb;
1172        struct msdos_sb_info *sbi = MSDOS_SB(sb);
1173        struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1174        sector_t blknr, start_blknr, last_blknr;
1175        unsigned long size, copy;
1176        int err, i, n, offset, cluster[2];
1177
1178        /*
1179         * The minimum cluster size is 512bytes, and maximum entry
1180         * size is 32*slots (672bytes).  So, iff the cluster size is
1181         * 512bytes, we may need two clusters.
1182         */
1183        size = nr_slots * sizeof(struct msdos_dir_entry);
1184        *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1185        BUG_ON(*nr_cluster > 2);
1186
1187        err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1188        if (err)
1189                goto error;
1190
1191        /*
1192         * First stage: Fill the directory entry.  NOTE: This cluster
1193         * is not referenced from any inode yet, so updates order is
1194         * not important.
1195         */
1196        i = n = copy = 0;
1197        do {
1198                start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1199                last_blknr = start_blknr + sbi->sec_per_clus;
1200                while (blknr < last_blknr) {
1201                        bhs[n] = sb_getblk(sb, blknr);
1202                        if (!bhs[n]) {
1203                                err = -ENOMEM;
1204                                goto error_nomem;
1205                        }
1206
1207                        /* fill the directory entry */
1208                        copy = min(size, sb->s_blocksize);
1209                        memcpy(bhs[n]->b_data, slots, copy);
1210                        slots += copy;
1211                        size -= copy;
1212                        set_buffer_uptodate(bhs[n]);
1213                        mark_buffer_dirty_inode(bhs[n], dir);
1214                        if (!size)
1215                                break;
1216                        n++;
1217                        blknr++;
1218                }
1219        } while (++i < *nr_cluster);
1220
1221        memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1222        offset = copy - sizeof(struct msdos_dir_entry);
1223        get_bh(bhs[n]);
1224        *bh = bhs[n];
1225        *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1226        *i_pos = fat_make_i_pos(sb, *bh, *de);
1227
1228        /* Second stage: clear the rest of cluster, and write outs */
1229        err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1230        if (err)
1231                goto error_free;
1232
1233        return cluster[0];
1234
1235error_free:
1236        brelse(*bh);
1237        *bh = NULL;
1238        n = 0;
1239error_nomem:
1240        for (i = 0; i < n; i++)
1241                bforget(bhs[i]);
1242        fat_free_clusters(dir, cluster[0]);
1243error:
1244        return err;
1245}
1246
1247int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1248                    struct fat_slot_info *sinfo)
1249{
1250        struct super_block *sb = dir->i_sb;
1251        struct msdos_sb_info *sbi = MSDOS_SB(sb);
1252        struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1253        struct msdos_dir_entry *uninitialized_var(de);
1254        int err, free_slots, i, nr_bhs;
1255        loff_t pos, i_pos;
1256
1257        sinfo->nr_slots = nr_slots;
1258
1259        /* First stage: search free direcotry entries */
1260        free_slots = nr_bhs = 0;
1261        bh = prev = NULL;
1262        pos = 0;
1263        err = -ENOSPC;
1264        while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1265                /* check the maximum size of directory */
1266                if (pos >= FAT_MAX_DIR_SIZE)
1267                        goto error;
1268
1269                if (IS_FREE(de->name)) {
1270                        if (prev != bh) {
1271                                get_bh(bh);
1272                                bhs[nr_bhs] = prev = bh;
1273                                nr_bhs++;
1274                        }
1275                        free_slots++;
1276                        if (free_slots == nr_slots)
1277                                goto found;
1278                } else {
1279                        for (i = 0; i < nr_bhs; i++)
1280                                brelse(bhs[i]);
1281                        prev = NULL;
1282                        free_slots = nr_bhs = 0;
1283                }
1284        }
1285        if (dir->i_ino == MSDOS_ROOT_INO) {
1286                if (sbi->fat_bits != 32)
1287                        goto error;
1288        } else if (MSDOS_I(dir)->i_start == 0) {
1289                fat_msg(sb, KERN_ERR, "Corrupted directory (i_pos %lld)",
1290                       MSDOS_I(dir)->i_pos);
1291                err = -EIO;
1292                goto error;
1293        }
1294
1295found:
1296        err = 0;
1297        pos -= free_slots * sizeof(*de);
1298        nr_slots -= free_slots;
1299        if (free_slots) {
1300                /*
1301                 * Second stage: filling the free entries with new entries.
1302                 * NOTE: If this slots has shortname, first, we write
1303                 * the long name slots, then write the short name.
1304                 */
1305                int size = free_slots * sizeof(*de);
1306                int offset = pos & (sb->s_blocksize - 1);
1307                int long_bhs = nr_bhs - (nr_slots == 0);
1308
1309                /* Fill the long name slots. */
1310                for (i = 0; i < long_bhs; i++) {
1311                        int copy = min_t(int, sb->s_blocksize - offset, size);
1312                        memcpy(bhs[i]->b_data + offset, slots, copy);
1313                        mark_buffer_dirty_inode(bhs[i], dir);
1314                        offset = 0;
1315                        slots += copy;
1316                        size -= copy;
1317                }
1318                if (long_bhs && IS_DIRSYNC(dir))
1319                        err = fat_sync_bhs(bhs, long_bhs);
1320                if (!err && i < nr_bhs) {
1321                        /* Fill the short name slot. */
1322                        int copy = min_t(int, sb->s_blocksize - offset, size);
1323                        memcpy(bhs[i]->b_data + offset, slots, copy);
1324                        mark_buffer_dirty_inode(bhs[i], dir);
1325                        if (IS_DIRSYNC(dir))
1326                                err = sync_dirty_buffer(bhs[i]);
1327                }
1328                for (i = 0; i < nr_bhs; i++)
1329                        brelse(bhs[i]);
1330                if (err)
1331                        goto error_remove;
1332        }
1333
1334        if (nr_slots) {
1335                int cluster, nr_cluster;
1336
1337                /*
1338                 * Third stage: allocate the cluster for new entries.
1339                 * And initialize the cluster with new entries, then
1340                 * add the cluster to dir.
1341                 */
1342                cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1343                                              &de, &bh, &i_pos);
1344                if (cluster < 0) {
1345                        err = cluster;
1346                        goto error_remove;
1347                }
1348                err = fat_chain_add(dir, cluster, nr_cluster);
1349                if (err) {
1350                        fat_free_clusters(dir, cluster);
1351                        goto error_remove;
1352                }
1353                if (dir->i_size & (sbi->cluster_size - 1)) {
1354                        fat_fs_error(sb, "Odd directory size");
1355                        dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1356                                & ~((loff_t)sbi->cluster_size - 1);
1357                }
1358                dir->i_size += nr_cluster << sbi->cluster_bits;
1359                MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1360        }
1361        sinfo->slot_off = pos;
1362        sinfo->de = de;
1363        sinfo->bh = bh;
1364        sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1365
1366        return 0;
1367
1368error:
1369        brelse(bh);
1370        for (i = 0; i < nr_bhs; i++)
1371                brelse(bhs[i]);
1372        return err;
1373
1374error_remove:
1375        brelse(bh);
1376        if (free_slots)
1377                __fat_remove_entries(dir, pos, free_slots);
1378        return err;
1379}
1380
1381EXPORT_SYMBOL_GPL(fat_add_entries);
1382
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