fs/fat/dir.c

   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/msdos_fs.h>
  20 #include <linux/smp_lock.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/compat.h>
  23 #include <asm/uaccess.h>
  24
  25 static inline loff_t fat_make_i_pos(struct super_block *sb,
  26                                     struct buffer_head *bh,
  27                                     struct msdos_dir_entry *de)
  28 {
  29         return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
  30                 | (de - (struct msdos_dir_entry *)bh->b_data);
  31 }
  32
  33 static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
  34                                      sector_t phys)
  35 {
  36         struct super_block *sb = dir->i_sb;
  37         struct msdos_sb_info *sbi = MSDOS_SB(sb);
  38         struct buffer_head *bh;
  39         int sec;
  40
  41         /* This is not a first sector of cluster, or sec_per_clus == 1 */
  42         if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
  43                 return;
  44         /* root dir of FAT12/FAT16 */
  45         if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
  46                 return;
  47
  48         bh = sb_find_get_block(sb, phys);
  49         if (bh == NULL || !buffer_uptodate(bh)) {
  50                 for (sec = 0; sec < sbi->sec_per_clus; sec++)
  51                         sb_breadahead(sb, phys + sec);
  52         }
  53         brelse(bh);
  54 }
  55
  56 /* Returns the inode number of the directory entry at offset pos. If bh is
  57    non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
  58    returned in bh.
  59    AV. Most often we do it item-by-item. Makes sense to optimize.
  60    AV. OK, there we go: if both bh and de are non-NULL we assume that we just
  61    AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
  62    AV. It's done in fat_get_entry() (inlined), here the slow case lives.
  63    AV. Additionally, when we return -1 (i.e. reached the end of directory)
  64    AV. we make bh NULL.
  65  */
  66 static int fat__get_entry(struct inode *dir, loff_t *pos,
  67                           struct buffer_head **bh, struct msdos_dir_entry **de)
  68 {
  69         struct super_block *sb = dir->i_sb;
  70         sector_t phys, iblock;
  71         unsigned long mapped_blocks;
  72         int err, offset;
  73
  74 next:
  75         if (*bh)
  76                 brelse(*bh);
  77
  78         *bh = NULL;
  79         iblock = *pos >> sb->s_blocksize_bits;
  80         err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
  81         if (err || !phys)
  82                 return -1;      /* beyond EOF or error */
  83
  84         fat_dir_readahead(dir, iblock, phys);
  85
  86         *bh = sb_bread(sb, phys);
  87         if (*bh == NULL) {
  88                 printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
  89                        (unsigned long long)phys);
  90                 /* skip this block */
  91                 *pos = (iblock + 1) << sb->s_blocksize_bits;
  92                 goto next;
  93         }
  94
  95         offset = *pos & (sb->s_blocksize - 1);
  96         *pos += sizeof(struct msdos_dir_entry);
  97         *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
  98
  99         return 0;
 100 }
 101
 102 static inline int fat_get_entry(struct inode *dir, loff_t *pos,
 103                                 struct buffer_head **bh,
 104                                 struct msdos_dir_entry **de)
 105 {
 106         /* Fast stuff first */
 107         if (*bh && *de &&
 108             (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
 109                 *pos += sizeof(struct msdos_dir_entry);
 110                 (*de)++;
 111                 return 0;
 112         }
 113         return fat__get_entry(dir, pos, bh, de);
 114 }
 115
 116 /*
 117  * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
 118  * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
 119  * colon as an escape character since it is normally invalid on the vfat
 120  * filesystem. The following four characters are the hexadecimal digits
 121  * of Unicode value. This lets us do a full dump and restore of Unicode
 122  * filenames. We could get into some trouble with long Unicode names,
 123  * but ignore that right now.
 124  * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
 125  */
 126 static int uni16_to_x8(unsigned char *ascii, const wchar_t *uni, int len,
 127                        int uni_xlate, struct nls_table *nls)
 128 {
 129         const wchar_t *ip;
 130         wchar_t ec;
 131         unsigned char *op, nc;
 132         int charlen;
 133         int k;
 134
 135         ip = uni;
 136         op = ascii;
 137
 138         while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) {
 139                 ec = *ip++;
 140                 if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
 141                         op += charlen;
 142                         len -= charlen;
 143                 } else {
 144                         if (uni_xlate == 1) {
 145                                 *op = ':';
 146                                 for (k = 4; k > 0; k--) {
 147                                         nc = ec & 0xF;
 148                                         op[k] = nc > 9  ? nc + ('a' - 10)
 149                                                         : nc + '0';
 150                                         ec >>= 4;
 151                                 }
 152                                 op += 5;
 153                                 len -= 5;
 154                         } else {
 155                                 *op++ = '?';
 156                                 len--;
 157                         }
 158                 }
 159         }
 160
 161         if (unlikely(*ip)) {
 162                 printk(KERN_WARNING "FAT: filename was truncated while "
 163                        "converting.");
 164         }
 165
 166         *op = 0;
 167         return (op - ascii);
 168 }
 169
 170 static inline int fat_uni_to_x8(struct msdos_sb_info *sbi, const wchar_t *uni,
 171                                 unsigned char *buf, int size)
 172 {
 173         if (sbi->options.utf8)
 174                 return utf8_wcstombs(buf, uni, size);
 175         else
 176                 return uni16_to_x8(buf, uni, size, sbi->options.unicode_xlate,
 177                                    sbi->nls_io);
 178 }
 179
 180 static inline int
 181 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
 182 {
 183         int charlen;
 184
 185         charlen = t->char2uni(c, clen, uni);
 186         if (charlen < 0) {
 187                 *uni = 0x003f;  /* a question mark */
 188                 charlen = 1;
 189         }
 190         return charlen;
 191 }
 192
 193 static inline int
 194 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
 195 {
 196         int charlen;
 197         wchar_t wc;
 198
 199         charlen = t->char2uni(c, clen, &wc);
 200         if (charlen < 0) {
 201                 *uni = 0x003f;  /* a question mark */
 202                 charlen = 1;
 203         } else if (charlen <= 1) {
 204                 unsigned char nc = t->charset2lower[*c];
 205
 206                 if (!nc)
 207                         nc = *c;
 208
 209                 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
 210                         *uni = 0x003f;  /* a question mark */
 211                         charlen = 1;
 212                 }
 213         } else
 214                 *uni = wc;
 215
 216         return charlen;
 217 }
 218
 219 static inline int
 220 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
 221                   wchar_t *uni_buf, unsigned short opt, int lower)
 222 {
 223         int len = 0;
 224
 225         if (opt & VFAT_SFN_DISPLAY_LOWER)
 226                 len =  fat_short2lower_uni(nls, buf, buf_size, uni_buf);
 227         else if (opt & VFAT_SFN_DISPLAY_WIN95)
 228                 len = fat_short2uni(nls, buf, buf_size, uni_buf);
 229         else if (opt & VFAT_SFN_DISPLAY_WINNT) {
 230                 if (lower)
 231                         len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
 232                 else
 233                         len = fat_short2uni(nls, buf, buf_size, uni_buf);
 234         } else
 235                 len = fat_short2uni(nls, buf, buf_size, uni_buf);
 236
 237         return len;
 238 }
 239
 240 static inline int fat_name_match(struct msdos_sb_info *sbi,
 241                                  const unsigned char *a, int a_len,
 242                                  const unsigned char *b, int b_len)
 243 {
 244         if (a_len != b_len)
 245                 return 0;
 246
 247         if (sbi->options.name_check != 's')
 248                 return !nls_strnicmp(sbi->nls_io, a, b, a_len);
 249         else
 250                 return !memcmp(a, b, a_len);
 251 }
 252
 253 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
 254
 255 /**
 256  * fat_parse_long - Parse extended directory entry.
 257  *
 258  * This function returns zero on success, negative value on error, or one of
 259  * the following:
 260  *
 261  * %PARSE_INVALID - Directory entry is invalid.
 262  * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
 263  * %PARSE_EOF - Directory has no more entries.
 264  */
 265 static int fat_parse_long(struct inode *dir, loff_t *pos,
 266                           struct buffer_head **bh, struct msdos_dir_entry **de,
 267                           wchar_t **unicode, unsigned char *nr_slots)
 268 {
 269         struct msdos_dir_slot *ds;
 270         unsigned char id, slot, slots, alias_checksum;
 271
 272         if (!*unicode) {
 273                 *unicode = __getname();
 274                 if (!*unicode) {
 275                         brelse(*bh);
 276                         return -ENOMEM;
 277                 }
 278         }
 279 parse_long:
 280         slots = 0;
 281         ds = (struct msdos_dir_slot *)*de;
 282         id = ds->id;
 283         if (!(id & 0x40))
 284                 return PARSE_INVALID;
 285         slots = id & ~0x40;
 286         if (slots > 20 || !slots)       /* ceil(256 * 2 / 26) */
 287                 return PARSE_INVALID;
 288         *nr_slots = slots;
 289         alias_checksum = ds->alias_checksum;
 290
 291         slot = slots;
 292         while (1) {
 293                 int offset;
 294
 295                 slot--;
 296                 offset = slot * 13;
 297                 fat16_towchar(*unicode + offset, ds->name0_4, 5);
 298                 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
 299                 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
 300
 301                 if (ds->id & 0x40)
 302                         (*unicode)[offset + 13] = 0;
 303                 if (fat_get_entry(dir, pos, bh, de) < 0)
 304                         return PARSE_EOF;
 305                 if (slot == 0)
 306                         break;
 307                 ds = (struct msdos_dir_slot *)*de;
 308                 if (ds->attr != ATTR_EXT)
 309                         return PARSE_NOT_LONGNAME;
 310                 if ((ds->id & ~0x40) != slot)
 311                         goto parse_long;
 312                 if (ds->alias_checksum != alias_checksum)
 313                         goto parse_long;
 314         }
 315         if ((*de)->name[0] == DELETED_FLAG)
 316                 return PARSE_INVALID;
 317         if ((*de)->attr == ATTR_EXT)
 318                 goto parse_long;
 319         if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
 320                 return PARSE_INVALID;
 321         if (fat_checksum((*de)->name) != alias_checksum)
 322                 *nr_slots = 0;
 323
 324         return 0;
 325 }
 326
 327 /*
 328  * Return values: negative -> error, 0 -> not found, positive -> found,
 329  * value is the total amount of slots, including the shortname entry.
 330  */
 331 int fat_search_long(struct inode *inode, const unsigned char *name,
 332                     int name_len, struct fat_slot_info *sinfo)
 333 {
 334         struct super_block *sb = inode->i_sb;
 335         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 336         struct buffer_head *bh = NULL;
 337         struct msdos_dir_entry *de;
 338         struct nls_table *nls_disk = sbi->nls_disk;
 339         unsigned char nr_slots;
 340         wchar_t bufuname[14];
 341         wchar_t *unicode = NULL;
 342         unsigned char work[MSDOS_NAME];
 343         unsigned char *bufname = NULL;
 344         unsigned short opt_shortname = sbi->options.shortname;
 345         loff_t cpos = 0;
 346         int chl, i, j, last_u, err, len;
 347
 348         bufname = __getname();
 349         if (!bufname)
 350                 return -ENOMEM;
 351
 352         err = -ENOENT;
 353         while (1) {
 354                 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
 355                         goto end_of_dir;
 356 parse_record:
 357                 nr_slots = 0;
 358                 if (de->name[0] == DELETED_FLAG)
 359                         continue;
 360                 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
 361                         continue;
 362                 if (de->attr != ATTR_EXT && IS_FREE(de->name))
 363                         continue;
 364                 if (de->attr == ATTR_EXT) {
 365                         int status = fat_parse_long(inode, &cpos, &bh, &de,
 366                                                     &unicode, &nr_slots);
 367                         if (status < 0)
 368                                 return status;
 369                         else if (status == PARSE_INVALID)
 370                                 continue;
 371                         else if (status == PARSE_NOT_LONGNAME)
 372                                 goto parse_record;
 373                         else if (status == PARSE_EOF)
 374                                 goto end_of_dir;
 375                 }
 376
 377                 memcpy(work, de->name, sizeof(de->name));
 378                 /* see namei.c, msdos_format_name */
 379                 if (work[0] == 0x05)
 380                         work[0] = 0xE5;
 381                 for (i = 0, j = 0, last_u = 0; i < 8;) {
 382                         if (!work[i])
 383                                 break;
 384                         chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
 385                                                 &bufuname[j++], opt_shortname,
 386                                                 de->lcase & CASE_LOWER_BASE);
 387                         if (chl <= 1) {
 388                                 if (work[i] != ' ')
 389                                         last_u = j;
 390                         } else {
 391                                 last_u = j;
 392                         }
 393                         i += chl;
 394                 }
 395                 j = last_u;
 396                 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
 397                 for (i = 8; i < MSDOS_NAME;) {
 398                         if (!work[i])
 399                                 break;
 400                         chl = fat_shortname2uni(nls_disk, &work[i],
 401                                                 MSDOS_NAME - i,
 402                                                 &bufuname[j++], opt_shortname,
 403                                                 de->lcase & CASE_LOWER_EXT);
 404                         if (chl <= 1) {
 405                                 if (work[i] != ' ')
 406                                         last_u = j;
 407                         } else {
 408                                 last_u = j;
 409                         }
 410                         i += chl;
 411                 }
 412                 if (!last_u)
 413                         continue;
 414
 415                 /* Compare shortname */
 416                 bufuname[last_u] = 0x0000;
 417                 len = fat_uni_to_x8(sbi, bufuname, bufname, PATH_MAX);
 418                 if (fat_name_match(sbi, name, name_len, bufname, len))
 419                         goto found;
 420
 421                 if (nr_slots) {
 422                         /* Compare longname */
 423                         len = fat_uni_to_x8(sbi, unicode, bufname, PATH_MAX);
 424                         if (fat_name_match(sbi, name, name_len, bufname, len))
 425                                 goto found;
 426                 }
 427         }
 428
 429 found:
 430         nr_slots++;     /* include the de */
 431         sinfo->slot_off = cpos - nr_slots * sizeof(*de);
 432         sinfo->nr_slots = nr_slots;
 433         sinfo->de = de;
 434         sinfo->bh = bh;
 435         sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
 436         err = 0;
 437 end_of_dir:
 438         if (bufname)
 439                 __putname(bufname);
 440         if (unicode)
 441                 __putname(unicode);
 442
 443         return err;
 444 }
 445
 446 EXPORT_SYMBOL_GPL(fat_search_long);
 447
 448 struct fat_ioctl_filldir_callback {
 449         void __user *dirent;
 450         int result;
 451         /* for dir ioctl */
 452         const char *longname;
 453         int long_len;
 454         const char *shortname;
 455         int short_len;
 456 };
 457
 458 static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
 459                          filldir_t filldir, int short_only, int both)
 460 {
 461         struct super_block *sb = inode->i_sb;
 462         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 463         struct buffer_head *bh;
 464         struct msdos_dir_entry *de;
 465         struct nls_table *nls_disk = sbi->nls_disk;
 466         unsigned char nr_slots;
 467         wchar_t bufuname[14];
 468         wchar_t *unicode = NULL;
 469         unsigned char c, work[MSDOS_NAME], bufname[56], *ptname = bufname;
 470         unsigned short opt_shortname = sbi->options.shortname;
 471         int isvfat = sbi->options.isvfat;
 472         int nocase = sbi->options.nocase;
 473         const char *fill_name;
 474         unsigned long inum;
 475         unsigned long lpos, dummy, *furrfu = &lpos;
 476         loff_t cpos;
 477         int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len;
 478         int ret = 0;
 479
 480         lock_super(sb);
 481
 482         cpos = filp->f_pos;
 483         /* Fake . and .. for the root directory. */
 484         if (inode->i_ino == MSDOS_ROOT_INO) {
 485                 while (cpos < 2) {
 486                         if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
 487                                 goto out;
 488                         cpos++;
 489                         filp->f_pos++;
 490                 }
 491                 if (cpos == 2) {
 492                         dummy = 2;
 493                         furrfu = &dummy;
 494                         cpos = 0;
 495                 }
 496         }
 497         if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
 498                 ret = -ENOENT;
 499                 goto out;
 500         }
 501
 502         bh = NULL;
 503 get_new:
 504         if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
 505                 goto end_of_dir;
 506 parse_record:
 507         nr_slots = 0;
 508         /* Check for long filename entry */
 509         if (isvfat) {
 510                 if (de->name[0] == DELETED_FLAG)
 511                         goto record_end;
 512                 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
 513                         goto record_end;
 514                 if (de->attr != ATTR_EXT && IS_FREE(de->name))
 515                         goto record_end;
 516         } else {
 517                 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
 518                         goto record_end;
 519         }
 520
 521         if (isvfat && de->attr == ATTR_EXT) {
 522                 int status = fat_parse_long(inode, &cpos, &bh, &de,
 523                                             &unicode, &nr_slots);
 524                 if (status < 0) {
 525                         filp->f_pos = cpos;
 526                         ret = status;
 527                         goto out;
 528                 } else if (status == PARSE_INVALID)
 529                         goto record_end;
 530                 else if (status == PARSE_NOT_LONGNAME)
 531                         goto parse_record;
 532                 else if (status == PARSE_EOF)
 533                         goto end_of_dir;
 534         }
 535
 536         if (sbi->options.dotsOK) {
 537                 ptname = bufname;
 538                 dotoffset = 0;
 539                 if (de->attr & ATTR_HIDDEN) {
 540                         *ptname++ = '.';
 541                         dotoffset = 1;
 542                 }
 543         }
 544
 545         memcpy(work, de->name, sizeof(de->name));
 546         /* see namei.c, msdos_format_name */
 547         if (work[0] == 0x05)
 548                 work[0] = 0xE5;
 549         for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
 550                 if (!(c = work[i]))
 551                         break;
 552                 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
 553                                         &bufuname[j++], opt_shortname,
 554                                         de->lcase & CASE_LOWER_BASE);
 555                 if (chl <= 1) {
 556                         ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
 557                         if (c != ' ') {
 558                                 last = i;
 559                                 last_u = j;
 560                         }
 561                 } else {
 562                         last_u = j;
 563                         for (chi = 0; chi < chl && i < 8; chi++) {
 564                                 ptname[i] = work[i];
 565                                 i++; last = i;
 566                         }
 567                 }
 568         }
 569         i = last;
 570         j = last_u;
 571         fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
 572         ptname[i++] = '.';
 573         for (i2 = 8; i2 < MSDOS_NAME;) {
 574                 if (!(c = work[i2]))
 575                         break;
 576                 chl = fat_shortname2uni(nls_disk, &work[i2], MSDOS_NAME - i2,
 577                                         &bufuname[j++], opt_shortname,
 578                                         de->lcase & CASE_LOWER_EXT);
 579                 if (chl <= 1) {
 580                         i2++;
 581                         ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
 582                         if (c != ' ') {
 583                                 last = i;
 584                                 last_u = j;
 585                         }
 586                 } else {
 587                         last_u = j;
 588                         for (chi = 0; chi < chl && i2 < MSDOS_NAME; chi++) {
 589                                 ptname[i++] = work[i2++];
 590                                 last = i;
 591                         }
 592                 }
 593         }
 594         if (!last)
 595                 goto record_end;
 596
 597         i = last + dotoffset;
 598         j = last_u;
 599
 600         lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
 601         if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
 602                 inum = inode->i_ino;
 603         else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 604                 inum = parent_ino(filp->f_path.dentry);
 605         } else {
 606                 loff_t i_pos = fat_make_i_pos(sb, bh, de);
 607                 struct inode *tmp = fat_iget(sb, i_pos);
 608                 if (tmp) {
 609                         inum = tmp->i_ino;
 610                         iput(tmp);
 611                 } else
 612                         inum = iunique(sb, MSDOS_ROOT_INO);
 613         }
 614
 615         if (isvfat) {
 616                 bufuname[j] = 0x0000;
 617                 i = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));
 618         }
 619
 620         fill_name = bufname;
 621         fill_len = i;
 622         if (!short_only && nr_slots) {
 623                 /* convert the unicode long name. 261 is maximum size
 624                  * of unicode buffer. (13 * slots + nul) */
 625                 void *longname = unicode + 261;
 626                 int buf_size = PATH_MAX - (261 * sizeof(unicode[0]));
 627                 int long_len = fat_uni_to_x8(sbi, unicode, longname, buf_size);
 628
 629                 if (!both) {
 630                         fill_name = longname;
 631                         fill_len = long_len;
 632                 } else {
 633                         /* hack for fat_ioctl_filldir() */
 634                         struct fat_ioctl_filldir_callback *p = dirent;
 635
 636                         p->longname = longname;
 637                         p->long_len = long_len;
 638                         p->shortname = bufname;
 639                         p->short_len = i;
 640                         fill_name = NULL;
 641                         fill_len = 0;
 642                 }
 643         }
 644         if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
 645                     (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
 646                 goto fill_failed;
 647
 648 record_end:
 649         furrfu = &lpos;
 650         filp->f_pos = cpos;
 651         goto get_new;
 652 end_of_dir:
 653         filp->f_pos = cpos;
 654 fill_failed:
 655         brelse(bh);
 656         if (unicode)
 657                 __putname(unicode);
 658 out:
 659         unlock_super(sb);
 660         return ret;
 661 }
 662
 663 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
 664 {
 665         struct inode *inode = filp->f_path.dentry->d_inode;
 666         return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
 667 }
 668
 669 #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type)                          \
 670 static int func(void *__buf, const char *name, int name_len,               \
 671                              loff_t offset, u64 ino, unsigned int d_type)  \
 672 {                                                                          \
 673         struct fat_ioctl_filldir_callback *buf = __buf;                    \
 674         struct dirent_type __user *d1 = buf->dirent;                       \
 675         struct dirent_type __user *d2 = d1 + 1;                            \
 676                                                                            \
 677         if (buf->result)                                                   \
 678                 return -EINVAL;                                            \
 679         buf->result++;                                                     \
 680                                                                            \
 681         if (name != NULL) {                                                \
 682                 /* dirent has only short name */                           \
 683                 if (name_len >= sizeof(d1->d_name))                        \
 684                         name_len = sizeof(d1->d_name) - 1;                 \
 685                                                                            \
 686                 if (put_user(0, d2->d_name)                     ||         \
 687                     put_user(0, &d2->d_reclen)                  ||         \
 688                     copy_to_user(d1->d_name, name, name_len)    ||         \
 689                     put_user(0, d1->d_name + name_len)          ||         \
 690                     put_user(name_len, &d1->d_reclen))                     \
 691                         goto efault;                                       \
 692         } else {                                                           \
 693                 /* dirent has short and long name */                       \
 694                 const char *longname = buf->longname;                      \
 695                 int long_len = buf->long_len;                              \
 696                 const char *shortname = buf->shortname;                    \
 697                 int short_len = buf->short_len;                            \
 698                                                                            \
 699                 if (long_len >= sizeof(d1->d_name))                        \
 700                         long_len = sizeof(d1->d_name) - 1;                 \
 701                 if (short_len >= sizeof(d1->d_name))                       \
 702                         short_len = sizeof(d1->d_name) - 1;                \
 703                                                                            \
 704                 if (copy_to_user(d2->d_name, longname, long_len)        || \
 705                     put_user(0, d2->d_name + long_len)                  || \
 706                     put_user(long_len, &d2->d_reclen)                   || \
 707                     put_user(ino, &d2->d_ino)                           || \
 708                     put_user(offset, &d2->d_off)                        || \
 709                     copy_to_user(d1->d_name, shortname, short_len)      || \
 710                     put_user(0, d1->d_name + short_len)                 || \
 711                     put_user(short_len, &d1->d_reclen))                    \
 712                         goto efault;                                       \
 713         }                                                                  \
 714         return 0;                                                          \
 715 efault:                                                                    \
 716         buf->result = -EFAULT;                                             \
 717         return -EFAULT;                                                    \
 718 }
 719
 720 FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
 721
 722 static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
 723                              void __user *dirent, filldir_t filldir,
 724                              int short_only, int both)
 725 {
 726         struct fat_ioctl_filldir_callback buf;
 727         int ret;
 728
 729         buf.dirent = dirent;
 730         buf.result = 0;
 731         mutex_lock(&inode->i_mutex);
 732         ret = -ENOENT;
 733         if (!IS_DEADDIR(inode)) {
 734                 ret = __fat_readdir(inode, filp, &buf, filldir,
 735                                     short_only, both);
 736         }
 737         mutex_unlock(&inode->i_mutex);
 738         if (ret >= 0)
 739                 ret = buf.result;
 740         return ret;
 741 }
 742
 743 static int fat_dir_ioctl(struct inode *inode, struct file *filp,
 744                          unsigned int cmd, unsigned long arg)
 745 {
 746         struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
 747         int short_only, both;
 748
 749         switch (cmd) {
 750         case VFAT_IOCTL_READDIR_SHORT:
 751                 short_only = 1;
 752                 both = 0;
 753                 break;
 754         case VFAT_IOCTL_READDIR_BOTH:
 755                 short_only = 0;
 756                 both = 1;
 757                 break;
 758         default:
 759                 return fat_generic_ioctl(inode, filp, cmd, arg);
 760         }
 761
 762         if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2])))
 763                 return -EFAULT;
 764         /*
 765          * Yes, we don't need this put_user() absolutely. However old
 766          * code didn't return the right value. So, app use this value,
 767          * in order to check whether it is EOF.
 768          */
 769         if (put_user(0, &d1->d_reclen))
 770                 return -EFAULT;
 771
 772         return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
 773                                  short_only, both);
 774 }
 775
 776 #ifdef CONFIG_COMPAT
 777 #define VFAT_IOCTL_READDIR_BOTH32       _IOR('r', 1, struct compat_dirent[2])
 778 #define VFAT_IOCTL_READDIR_SHORT32      _IOR('r', 2, struct compat_dirent[2])
 779
 780 FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
 781
 782 static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
 783                                  unsigned long arg)
 784 {
 785         struct inode *inode = filp->f_path.dentry->d_inode;
 786         struct compat_dirent __user *d1 = compat_ptr(arg);
 787         int short_only, both;
 788
 789         switch (cmd) {
 790         case VFAT_IOCTL_READDIR_SHORT32:
 791                 short_only = 1;
 792                 both = 0;
 793                 break;
 794         case VFAT_IOCTL_READDIR_BOTH32:
 795                 short_only = 0;
 796                 both = 1;
 797                 break;
 798         default:
 799                 return -ENOIOCTLCMD;
 800         }
 801
 802         if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
 803                 return -EFAULT;
 804         /*
 805          * Yes, we don't need this put_user() absolutely. However old
 806          * code didn't return the right value. So, app use this value,
 807          * in order to check whether it is EOF.
 808          */
 809         if (put_user(0, &d1->d_reclen))
 810                 return -EFAULT;
 811
 812         return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
 813                                  short_only, both);
 814 }
 815 #endif /* CONFIG_COMPAT */
 816
 817 const struct file_operations fat_dir_operations = {
 818         .read           = generic_read_dir,
 819         .readdir        = fat_readdir,
 820         .ioctl          = fat_dir_ioctl,
 821 #ifdef CONFIG_COMPAT
 822         .compat_ioctl   = fat_compat_dir_ioctl,
 823 #endif
 824         .fsync          = file_fsync,
 825 };
 826
 827 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
 828                                struct buffer_head **bh,
 829                                struct msdos_dir_entry **de)
 830 {
 831         while (fat_get_entry(dir, pos, bh, de) >= 0) {
 832                 /* free entry or long name entry or volume label */
 833                 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
 834                         return 0;
 835         }
 836         return -ENOENT;
 837 }
 838
 839 /*
 840  * The ".." entry can not provide the "struct fat_slot_info" informations
 841  * for inode. So, this function provide the some informations only.
 842  */
 843 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
 844                          struct msdos_dir_entry **de, loff_t *i_pos)
 845 {
 846         loff_t offset;
 847
 848         offset = 0;
 849         *bh = NULL;
 850         while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
 851                 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 852                         *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
 853                         return 0;
 854                 }
 855         }
 856         return -ENOENT;
 857 }
 858
 859 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
 860
 861 /* See if directory is empty */
 862 int fat_dir_empty(struct inode *dir)
 863 {
 864         struct buffer_head *bh;
 865         struct msdos_dir_entry *de;
 866         loff_t cpos;
 867         int result = 0;
 868
 869         bh = NULL;
 870         cpos = 0;
 871         while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
 872                 if (strncmp(de->name, MSDOS_DOT   , MSDOS_NAME) &&
 873                     strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 874                         result = -ENOTEMPTY;
 875                         break;
 876                 }
 877         }
 878         brelse(bh);
 879         return result;
 880 }
 881
 882 EXPORT_SYMBOL_GPL(fat_dir_empty);
 883
 884 /*
 885  * fat_subdirs counts the number of sub-directories of dir. It can be run
 886  * on directories being created.
 887  */
 888 int fat_subdirs(struct inode *dir)
 889 {
 890         struct buffer_head *bh;
 891         struct msdos_dir_entry *de;
 892         loff_t cpos;
 893         int count = 0;
 894
 895         bh = NULL;
 896         cpos = 0;
 897         while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
 898                 if (de->attr & ATTR_DIR)
 899                         count++;
 900         }
 901         brelse(bh);
 902         return count;
 903 }
 904
 905 /*
 906  * Scans a directory for a given file (name points to its formatted name).
 907  * Returns an error code or zero.
 908  */
 909 int fat_scan(struct inode *dir, const unsigned char *name,
 910              struct fat_slot_info *sinfo)
 911 {
 912         struct super_block *sb = dir->i_sb;
 913
 914         sinfo->slot_off = 0;
 915         sinfo->bh = NULL;
 916         while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
 917                                    &sinfo->de) >= 0) {
 918                 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
 919                         sinfo->slot_off -= sizeof(*sinfo->de);
 920                         sinfo->nr_slots = 1;
 921                         sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
 922                         return 0;
 923                 }
 924         }
 925         return -ENOENT;
 926 }
 927
 928 EXPORT_SYMBOL_GPL(fat_scan);
 929
 930 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
 931 {
 932         struct super_block *sb = dir->i_sb;
 933         struct buffer_head *bh;
 934         struct msdos_dir_entry *de, *endp;
 935         int err = 0, orig_slots;
 936
 937         while (nr_slots) {
 938                 bh = NULL;
 939                 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
 940                         err = -EIO;
 941                         break;
 942                 }
 943
 944                 orig_slots = nr_slots;
 945                 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
 946                 while (nr_slots && de < endp) {
 947                         de->name[0] = DELETED_FLAG;
 948                         de++;
 949                         nr_slots--;
 950                 }
 951                 mark_buffer_dirty(bh);
 952                 if (IS_DIRSYNC(dir))
 953                         err = sync_dirty_buffer(bh);
 954                 brelse(bh);
 955                 if (err)
 956                         break;
 957
 958                 /* pos is *next* de's position, so this does `- sizeof(de)' */
 959                 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
 960         }
 961
 962         return err;
 963 }
 964
 965 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
 966 {
 967         struct msdos_dir_entry *de;
 968         struct buffer_head *bh;
 969         int err = 0, nr_slots;
 970
 971         /*
 972          * First stage: Remove the shortname. By this, the directory
 973          * entry is removed.
 974          */
 975         nr_slots = sinfo->nr_slots;
 976         de = sinfo->de;
 977         sinfo->de = NULL;
 978         bh = sinfo->bh;
 979         sinfo->bh = NULL;
 980         while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
 981                 de->name[0] = DELETED_FLAG;
 982                 de--;
 983                 nr_slots--;
 984         }
 985         mark_buffer_dirty(bh);
 986         if (IS_DIRSYNC(dir))
 987                 err = sync_dirty_buffer(bh);
 988         brelse(bh);
 989         if (err)
 990                 return err;
 991         dir->i_version++;
 992
 993         if (nr_slots) {
 994                 /*
 995                  * Second stage: remove the remaining longname slots.
 996                  * (This directory entry is already removed, and so return
 997                  * the success)
 998                  */
 999                 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
1000                 if (err) {
1001                         printk(KERN_WARNING
1002                                "FAT: Couldn't remove the long name slots\n");
1003                 }
1004         }
1005
1006         dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
1007         if (IS_DIRSYNC(dir))
1008                 (void)fat_sync_inode(dir);
1009         else
1010                 mark_inode_dirty(dir);
1011
1012         return 0;
1013 }
1014
1015 EXPORT_SYMBOL_GPL(fat_remove_entries);
1016
1017 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1018                               struct buffer_head **bhs, int nr_bhs)
1019 {
1020         struct super_block *sb = dir->i_sb;
1021         sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1022         int err, i, n;
1023
1024         /* Zeroing the unused blocks on this cluster */
1025         blknr += nr_used;
1026         n = nr_used;
1027         while (blknr < last_blknr) {
1028                 bhs[n] = sb_getblk(sb, blknr);
1029                 if (!bhs[n]) {
1030                         err = -ENOMEM;
1031                         goto error;
1032                 }
1033                 memset(bhs[n]->b_data, 0, sb->s_blocksize);
1034                 set_buffer_uptodate(bhs[n]);
1035                 mark_buffer_dirty(bhs[n]);
1036
1037                 n++;
1038                 blknr++;
1039                 if (n == nr_bhs) {
1040                         if (IS_DIRSYNC(dir)) {
1041                                 err = fat_sync_bhs(bhs, n);
1042                                 if (err)
1043                                         goto error;
1044                         }
1045                         for (i = 0; i < n; i++)
1046                                 brelse(bhs[i]);
1047                         n = 0;
1048                 }
1049         }
1050         if (IS_DIRSYNC(dir)) {
1051                 err = fat_sync_bhs(bhs, n);
1052                 if (err)
1053                         goto error;
1054         }
1055         for (i = 0; i < n; i++)
1056                 brelse(bhs[i]);
1057
1058         return 0;
1059
1060 error:
1061         for (i = 0; i < n; i++)
1062                 bforget(bhs[i]);
1063         return err;
1064 }
1065
1066 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1067 {
1068         struct super_block *sb = dir->i_sb;
1069         struct msdos_sb_info *sbi = MSDOS_SB(sb);
1070         struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1071         struct msdos_dir_entry *de;
1072         sector_t blknr;
1073         __le16 date, time;
1074         int err, cluster;
1075
1076         err = fat_alloc_clusters(dir, &cluster, 1);
1077         if (err)
1078                 goto error;
1079
1080         blknr = fat_clus_to_blknr(sbi, cluster);
1081         bhs[0] = sb_getblk(sb, blknr);
1082         if (!bhs[0]) {
1083                 err = -ENOMEM;
1084                 goto error_free;
1085         }
1086
1087         fat_date_unix2dos(ts->tv_sec, &time, &date);
1088
1089         de = (struct msdos_dir_entry *)bhs[0]->b_data;
1090         /* filling the new directory slots ("." and ".." entries) */
1091         memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1092         memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1093         de->attr = de[1].attr = ATTR_DIR;
1094         de[0].lcase = de[1].lcase = 0;
1095         de[0].time = de[1].time = time;
1096         de[0].date = de[1].date = date;
1097         de[0].ctime_cs = de[1].ctime_cs = 0;
1098         if (sbi->options.isvfat) {
1099                 /* extra timestamps */
1100                 de[0].ctime = de[1].ctime = time;
1101                 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1102         } else {
1103                 de[0].ctime = de[1].ctime = 0;
1104                 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1105         }
1106         de[0].start = cpu_to_le16(cluster);
1107         de[0].starthi = cpu_to_le16(cluster >> 16);
1108         de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
1109         de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
1110         de[0].size = de[1].size = 0;
1111         memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1112         set_buffer_uptodate(bhs[0]);
1113         mark_buffer_dirty(bhs[0]);
1114
1115         err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1116         if (err)
1117                 goto error_free;
1118
1119         return cluster;
1120
1121 error_free:
1122         fat_free_clusters(dir, cluster);
1123 error:
1124         return err;
1125 }
1126
1127 EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1128
1129 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1130                                int *nr_cluster, struct msdos_dir_entry **de,
1131                                struct buffer_head **bh, loff_t *i_pos)
1132 {
1133         struct super_block *sb = dir->i_sb;
1134         struct msdos_sb_info *sbi = MSDOS_SB(sb);
1135         struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1136         sector_t blknr, start_blknr, last_blknr;
1137         unsigned long size, copy;
1138         int err, i, n, offset, cluster[2];
1139
1140         /*
1141          * The minimum cluster size is 512bytes, and maximum entry
1142          * size is 32*slots (672bytes).  So, iff the cluster size is
1143          * 512bytes, we may need two clusters.
1144          */
1145         size = nr_slots * sizeof(struct msdos_dir_entry);
1146         *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1147         BUG_ON(*nr_cluster > 2);
1148
1149         err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1150         if (err)
1151                 goto error;
1152
1153         /*
1154          * First stage: Fill the directory entry.  NOTE: This cluster
1155          * is not referenced from any inode yet, so updates order is
1156          * not important.
1157          */
1158         i = n = copy = 0;
1159         do {
1160                 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1161                 last_blknr = start_blknr + sbi->sec_per_clus;
1162                 while (blknr < last_blknr) {
1163                         bhs[n] = sb_getblk(sb, blknr);
1164                         if (!bhs[n]) {
1165                                 err = -ENOMEM;
1166                                 goto error_nomem;
1167                         }
1168
1169                         /* fill the directory entry */
1170                         copy = min(size, sb->s_blocksize);
1171                         memcpy(bhs[n]->b_data, slots, copy);
1172                         slots += copy;
1173                         size -= copy;
1174                         set_buffer_uptodate(bhs[n]);
1175                         mark_buffer_dirty(bhs[n]);
1176                         if (!size)
1177                                 break;
1178                         n++;
1179                         blknr++;
1180                 }
1181         } while (++i < *nr_cluster);
1182
1183         memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1184         offset = copy - sizeof(struct msdos_dir_entry);
1185         get_bh(bhs[n]);
1186         *bh = bhs[n];
1187         *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1188         *i_pos = fat_make_i_pos(sb, *bh, *de);
1189
1190         /* Second stage: clear the rest of cluster, and write outs */
1191         err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1192         if (err)
1193                 goto error_free;
1194
1195         return cluster[0];
1196
1197 error_free:
1198         brelse(*bh);
1199         *bh = NULL;
1200         n = 0;
1201 error_nomem:
1202         for (i = 0; i < n; i++)
1203                 bforget(bhs[i]);
1204         fat_free_clusters(dir, cluster[0]);
1205 error:
1206         return err;
1207 }
1208
1209 int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1210                     struct fat_slot_info *sinfo)
1211 {
1212         struct super_block *sb = dir->i_sb;
1213         struct msdos_sb_info *sbi = MSDOS_SB(sb);
1214         struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1215         struct msdos_dir_entry *de;
1216         int err, free_slots, i, nr_bhs;
1217         loff_t pos, i_pos;
1218
1219         sinfo->nr_slots = nr_slots;
1220
1221         /* First stage: search free direcotry entries */
1222         free_slots = nr_bhs = 0;
1223         bh = prev = NULL;
1224         pos = 0;
1225         err = -ENOSPC;
1226         while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1227                 /* check the maximum size of directory */
1228                 if (pos >= FAT_MAX_DIR_SIZE)
1229                         goto error;
1230
1231                 if (IS_FREE(de->name)) {
1232                         if (prev != bh) {
1233                                 get_bh(bh);
1234                                 bhs[nr_bhs] = prev = bh;
1235                                 nr_bhs++;
1236                         }
1237                         free_slots++;
1238                         if (free_slots == nr_slots)
1239                                 goto found;
1240                 } else {
1241                         for (i = 0; i < nr_bhs; i++)
1242                                 brelse(bhs[i]);
1243                         prev = NULL;
1244                         free_slots = nr_bhs = 0;
1245                 }
1246         }
1247         if (dir->i_ino == MSDOS_ROOT_INO) {
1248                 if (sbi->fat_bits != 32)
1249                         goto error;
1250         } else if (MSDOS_I(dir)->i_start == 0) {
1251                 printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
1252                        MSDOS_I(dir)->i_pos);
1253                 err = -EIO;
1254                 goto error;
1255         }
1256
1257 found:
1258         err = 0;
1259         pos -= free_slots * sizeof(*de);
1260         nr_slots -= free_slots;
1261         if (free_slots) {
1262                 /*
1263                  * Second stage: filling the free entries with new entries.
1264                  * NOTE: If this slots has shortname, first, we write
1265                  * the long name slots, then write the short name.
1266                  */
1267                 int size = free_slots * sizeof(*de);
1268                 int offset = pos & (sb->s_blocksize - 1);
1269                 int long_bhs = nr_bhs - (nr_slots == 0);
1270
1271                 /* Fill the long name slots. */
1272                 for (i = 0; i < long_bhs; i++) {
1273                         int copy = min_t(int, sb->s_blocksize - offset, size);
1274                         memcpy(bhs[i]->b_data + offset, slots, copy);
1275                         mark_buffer_dirty(bhs[i]);
1276                         offset = 0;
1277                         slots += copy;
1278                         size -= copy;
1279                 }
1280                 if (long_bhs && IS_DIRSYNC(dir))
1281                         err = fat_sync_bhs(bhs, long_bhs);
1282                 if (!err && i < nr_bhs) {
1283                         /* Fill the short name slot. */
1284                         int copy = min_t(int, sb->s_blocksize - offset, size);
1285                         memcpy(bhs[i]->b_data + offset, slots, copy);
1286                         mark_buffer_dirty(bhs[i]);
1287                         if (IS_DIRSYNC(dir))
1288                                 err = sync_dirty_buffer(bhs[i]);
1289                 }
1290                 for (i = 0; i < nr_bhs; i++)
1291                         brelse(bhs[i]);
1292                 if (err)
1293                         goto error_remove;
1294         }
1295
1296         if (nr_slots) {
1297                 int cluster, nr_cluster;
1298
1299                 /*
1300                  * Third stage: allocate the cluster for new entries.
1301                  * And initialize the cluster with new entries, then
1302                  * add the cluster to dir.
1303                  */
1304                 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1305                                               &de, &bh, &i_pos);
1306                 if (cluster < 0) {
1307                         err = cluster;
1308                         goto error_remove;
1309                 }
1310                 err = fat_chain_add(dir, cluster, nr_cluster);
1311                 if (err) {
1312                         fat_free_clusters(dir, cluster);
1313                         goto error_remove;
1314                 }
1315                 if (dir->i_size & (sbi->cluster_size - 1)) {
1316                         fat_fs_panic(sb, "Odd directory size");
1317                         dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1318                                 & ~((loff_t)sbi->cluster_size - 1);
1319                 }
1320                 dir->i_size += nr_cluster << sbi->cluster_bits;
1321                 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1322         }
1323         sinfo->slot_off = pos;
1324         sinfo->de = de;
1325         sinfo->bh = bh;
1326         sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1327
1328         return 0;
1329
1330 error:
1331         brelse(bh);
1332         for (i = 0; i < nr_bhs; i++)
1333                 brelse(bhs[i]);
1334         return err;
1335
1336 error_remove:
1337         brelse(bh);
1338         if (free_slots)
1339                 __fat_remove_entries(dir, pos, free_slots);
1340         return err;
1341 }
1342
1343 EXPORT_SYMBOL_GPL(fat_add_entries);