release/src-rt-6.x/linux/linux-2.6/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/dirent.h>
  21 #include <linux/smp_lock.h>
  22 #include <linux/buffer_head.h>
  23 #include <linux/compat.h>
  24 #include <asm/uaccess.h>
  25
  26 static inline loff_t fat_make_i_pos(struct super_block *sb,
  27                                     struct buffer_head *bh,
  28                                     struct msdos_dir_entry *de)
  29 {
  30         return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
  31                 | (de - (struct msdos_dir_entry *)bh->b_data);
  32 }
  33
  34 static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
  35                                      sector_t phys)
  36 {
  37         struct super_block *sb = dir->i_sb;
  38         struct msdos_sb_info *sbi = MSDOS_SB(sb);
  39         struct buffer_head *bh;
  40         int sec;
  41
  42         /* This is not a first sector of cluster, or sec_per_clus == 1 */
  43         if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
  44                 return;
  45         /* root dir of FAT12/FAT16 */
  46         if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
  47                 return;
  48
  49         bh = sb_find_get_block(sb, phys);
  50         if (bh == NULL || !buffer_uptodate(bh)) {
  51                 for (sec = 0; sec < sbi->sec_per_clus; sec++)
  52                         sb_breadahead(sb, phys + sec);
  53         }
  54         brelse(bh);
  55 }
  56
  57 /* Returns the inode number of the directory entry at offset pos. If bh is
  58    non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
  59    returned in bh.
  60    AV. Most often we do it item-by-item. Makes sense to optimize.
  61    AV. OK, there we go: if both bh and de are non-NULL we assume that we just
  62    AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
  63    AV. It's done in fat_get_entry() (inlined), here the slow case lives.
  64    AV. Additionally, when we return -1 (i.e. reached the end of directory)
  65    AV. we make bh NULL.
  66  */
  67 static int fat__get_entry(struct inode *dir, loff_t *pos,
  68                           struct buffer_head **bh, struct msdos_dir_entry **de)
  69 {
  70         struct super_block *sb = dir->i_sb;
  71         sector_t phys, iblock;
  72         unsigned long mapped_blocks;
  73         int err, offset;
  74
  75 next:
  76         if (*bh)
  77                 brelse(*bh);
  78
  79         *bh = NULL;
  80         iblock = *pos >> sb->s_blocksize_bits;
  81         err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
  82         if (err || !phys)
  83                 return -1;      /* beyond EOF or error */
  84
  85         fat_dir_readahead(dir, iblock, phys);
  86
  87         *bh = sb_bread(sb, phys);
  88         if (*bh == NULL) {
  89                 printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
  90                        (unsigned long long)phys);
  91                 /* skip this block */
  92                 *pos = (iblock + 1) << sb->s_blocksize_bits;
  93                 goto next;
  94         }
  95
  96         offset = *pos & (sb->s_blocksize - 1);
  97         *pos += sizeof(struct msdos_dir_entry);
  98         *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
  99
 100         return 0;
 101 }
 102
 103 static inline int fat_get_entry(struct inode *dir, loff_t *pos,
 104                                 struct buffer_head **bh,
 105                                 struct msdos_dir_entry **de)
 106 {
 107         /* Fast stuff first */
 108         if (*bh && *de &&
 109             (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
 110                 *pos += sizeof(struct msdos_dir_entry);
 111                 (*de)++;
 112                 return 0;
 113         }
 114         return fat__get_entry(dir, pos, bh, de);
 115 }
 116
 117 /*
 118  * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
 119  * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
 120  * colon as an escape character since it is normally invalid on the vfat
 121  * filesystem. The following four characters are the hexadecimal digits
 122  * of Unicode value. This lets us do a full dump and restore of Unicode
 123  * filenames. We could get into some trouble with long Unicode names,
 124  * but ignore that right now.
 125  * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
 126  */
 127 static int uni16_to_x8(unsigned char *ascii, wchar_t *uni, int len,
 128                        int uni_xlate, struct nls_table *nls)
 129 {
 130         wchar_t *ip, 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
 171 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
 172 {
 173         int charlen;
 174
 175         charlen = t->char2uni(c, clen, uni);
 176         if (charlen < 0) {
 177                 *uni = 0x003f;  /* a question mark */
 178                 charlen = 1;
 179         }
 180         return charlen;
 181 }
 182
 183 static inline int
 184 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
 185 {
 186         int charlen;
 187         wchar_t wc;
 188
 189         charlen = t->char2uni(c, clen, &wc);
 190         if (charlen < 0) {
 191                 *uni = 0x003f;  /* a question mark */
 192                 charlen = 1;
 193         } else if (charlen <= 1) {
 194                 unsigned char nc = t->charset2lower[*c];
 195
 196                 if (!nc)
 197                         nc = *c;
 198
 199                 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
 200                         *uni = 0x003f;  /* a question mark */
 201                         charlen = 1;
 202                 }
 203         } else
 204                 *uni = wc;
 205
 206         return charlen;
 207 }
 208
 209 static inline int
 210 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
 211                   wchar_t *uni_buf, unsigned short opt, int lower)
 212 {
 213         int len = 0;
 214
 215         if (opt & VFAT_SFN_DISPLAY_LOWER)
 216                 len =  fat_short2lower_uni(nls, buf, buf_size, uni_buf);
 217         else if (opt & VFAT_SFN_DISPLAY_WIN95)
 218                 len = fat_short2uni(nls, buf, buf_size, uni_buf);
 219         else if (opt & VFAT_SFN_DISPLAY_WINNT) {
 220                 if (lower)
 221                         len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
 222                 else
 223                         len = fat_short2uni(nls, buf, buf_size, uni_buf);
 224         } else
 225                 len = fat_short2uni(nls, buf, buf_size, uni_buf);
 226
 227         return len;
 228 }
 229
 230 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
 231
 232 /**
 233  * fat_parse_long - Parse extended directory entry.
 234  *
 235  * This function returns zero on success, negative value on error, or one of
 236  * the following:
 237  *
 238  * %PARSE_INVALID - Directory entry is invalid.
 239  * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
 240  * %PARSE_EOF - Directory has no more entries.
 241  */
 242 static int fat_parse_long(struct inode *dir, loff_t *pos,
 243                           struct buffer_head **bh, struct msdos_dir_entry **de,
 244                           wchar_t **unicode, unsigned char *nr_slots)
 245 {
 246         struct msdos_dir_slot *ds;
 247         unsigned char id, slot, slots, alias_checksum;
 248
 249         if (!*unicode) {
 250                 *unicode = __getname();
 251                 if (!*unicode) {
 252                         brelse(*bh);
 253                         return -ENOMEM;
 254                 }
 255         }
 256 parse_long:
 257         slots = 0;
 258         ds = (struct msdos_dir_slot *)*de;
 259         id = ds->id;
 260         if (!(id & 0x40))
 261                 return PARSE_INVALID;
 262         slots = id & ~0x40;
 263         if (slots > 20 || !slots)       /* ceil(256 * 2 / 26) */
 264                 return PARSE_INVALID;
 265         *nr_slots = slots;
 266         alias_checksum = ds->alias_checksum;
 267
 268         slot = slots;
 269         while (1) {
 270                 int offset;
 271
 272                 slot--;
 273                 offset = slot * 13;
 274                 fat16_towchar(*unicode + offset, ds->name0_4, 5);
 275                 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
 276                 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
 277
 278                 if (ds->id & 0x40)
 279                         (*unicode)[offset + 13] = 0;
 280                 if (fat_get_entry(dir, pos, bh, de) < 0)
 281                         return PARSE_EOF;
 282                 if (slot == 0)
 283                         break;
 284                 ds = (struct msdos_dir_slot *)*de;
 285                 if (ds->attr != ATTR_EXT)
 286                         return PARSE_NOT_LONGNAME;
 287                 if ((ds->id & ~0x40) != slot)
 288                         goto parse_long;
 289                 if (ds->alias_checksum != alias_checksum)
 290                         goto parse_long;
 291         }
 292         if ((*de)->name[0] == DELETED_FLAG)
 293                 return PARSE_INVALID;
 294         if ((*de)->attr == ATTR_EXT)
 295                 goto parse_long;
 296         if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
 297                 return PARSE_INVALID;
 298         if (fat_checksum((*de)->name) != alias_checksum)
 299                 *nr_slots = 0;
 300
 301         return 0;
 302 }
 303
 304 /*
 305  * Return values: negative -> error, 0 -> not found, positive -> found,
 306  * value is the total amount of slots, including the shortname entry.
 307  */
 308 int fat_search_long(struct inode *inode, const unsigned char *name,
 309                     int name_len, struct fat_slot_info *sinfo)
 310 {
 311         struct super_block *sb = inode->i_sb;
 312         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 313         struct buffer_head *bh = NULL;
 314         struct msdos_dir_entry *de;
 315         struct nls_table *nls_io = sbi->nls_io;
 316         struct nls_table *nls_disk = sbi->nls_disk;
 317         wchar_t bufuname[14];
 318         unsigned char nr_slots;
 319         int xlate_len;
 320         wchar_t *unicode = NULL;
 321         unsigned char work[MSDOS_NAME];
 322         unsigned char *bufname = NULL;
 323         int uni_xlate = sbi->options.unicode_xlate;
 324         int utf8 = sbi->options.utf8;
 325         int anycase = (sbi->options.name_check != 's');
 326         unsigned short opt_shortname = sbi->options.shortname;
 327         loff_t cpos = 0;
 328         int chl, i, j, last_u, err;
 329
 330         bufname = __getname();
 331         if (!bufname)
 332                 return -ENOMEM;
 333
 334         err = -ENOENT;
 335         while(1) {
 336                 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
 337                         goto EODir;
 338 parse_record:
 339                 nr_slots = 0;
 340                 if (de->name[0] == DELETED_FLAG)
 341                         continue;
 342                 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
 343                         continue;
 344                 if (de->attr != ATTR_EXT && IS_FREE(de->name))
 345                         continue;
 346                 if (de->attr == ATTR_EXT) {
 347                         int status = fat_parse_long(inode, &cpos, &bh, &de,
 348                                                     &unicode, &nr_slots);
 349                         if (status < 0)
 350                                 return status;
 351                         else if (status == PARSE_INVALID)
 352                                 continue;
 353                         else if (status == PARSE_NOT_LONGNAME)
 354                                 goto parse_record;
 355                         else if (status == PARSE_EOF)
 356                                 goto EODir;
 357                 }
 358
 359                 memcpy(work, de->name, sizeof(de->name));
 360                 /* see namei.c, msdos_format_name */
 361                 if (work[0] == 0x05)
 362                         work[0] = 0xE5;
 363                 for (i = 0, j = 0, last_u = 0; i < 8;) {
 364                         if (!work[i])
 365                                 break;
 366                         chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
 367                                                 &bufuname[j++], opt_shortname,
 368                                                 de->lcase & CASE_LOWER_BASE);
 369                         if (chl <= 1) {
 370                                 if (work[i] != ' ')
 371                                         last_u = j;
 372                         } else {
 373                                 last_u = j;
 374                         }
 375                         i += chl;
 376                 }
 377                 j = last_u;
 378                 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
 379                 for (i = 8; i < MSDOS_NAME;) {
 380                         if (!work[i])
 381                                 break;
 382                         chl = fat_shortname2uni(nls_disk, &work[i],
 383                                                 MSDOS_NAME - i,
 384                                                 &bufuname[j++], opt_shortname,
 385                                                 de->lcase & CASE_LOWER_EXT);
 386                         if (chl <= 1) {
 387                                 if (work[i] != ' ')
 388                                         last_u = j;
 389                         } else {
 390                                 last_u = j;
 391                         }
 392                         i += chl;
 393                 }
 394                 if (!last_u)
 395                         continue;
 396
 397                 bufuname[last_u] = 0x0000;
 398                 xlate_len = utf8
 399                         ?utf8_wcstombs(bufname, bufuname, PATH_MAX)
 400                         :uni16_to_x8(bufname, bufuname, PATH_MAX, uni_xlate, nls_io);
 401                 if (xlate_len == name_len)
 402                         if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
 403                             (anycase && !nls_strnicmp(nls_io, name, bufname,
 404                                                                 xlate_len)))
 405                                 goto Found;
 406
 407                 if (nr_slots) {
 408                         xlate_len = utf8
 409                                 ?utf8_wcstombs(bufname, unicode, PATH_MAX)
 410                                 :uni16_to_x8(bufname, unicode, PATH_MAX, uni_xlate, nls_io);
 411                         if (xlate_len != name_len)
 412                                 continue;
 413                         if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
 414                             (anycase && !nls_strnicmp(nls_io, name, bufname,
 415                                                                 xlate_len)))
 416                                 goto Found;
 417                 }
 418         }
 419
 420 Found:
 421         nr_slots++;     /* include the de */
 422         sinfo->slot_off = cpos - nr_slots * sizeof(*de);
 423         sinfo->nr_slots = nr_slots;
 424         sinfo->de = de;
 425         sinfo->bh = bh;
 426         sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
 427         err = 0;
 428 EODir:
 429         if (bufname)
 430                 __putname(bufname);
 431         if (unicode)
 432                 __putname(unicode);
 433
 434         return err;
 435 }
 436
 437 EXPORT_SYMBOL_GPL(fat_search_long);
 438
 439 struct fat_ioctl_filldir_callback {
 440         void __user *dirent;
 441         int result;
 442         /* for dir ioctl */
 443         const char *longname;
 444         int long_len;
 445         const char *shortname;
 446         int short_len;
 447 };
 448
 449 static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
 450                          filldir_t filldir, int short_only, int both)
 451 {
 452         struct super_block *sb = inode->i_sb;
 453         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 454         struct buffer_head *bh;
 455         struct msdos_dir_entry *de;
 456         struct nls_table *nls_io = sbi->nls_io;
 457         struct nls_table *nls_disk = sbi->nls_disk;
 458         unsigned char long_slots;
 459         const char *fill_name;
 460         int fill_len;
 461         wchar_t bufuname[14];
 462         wchar_t *unicode = NULL;
 463         unsigned char c, work[MSDOS_NAME], bufname[56], *ptname = bufname;
 464         unsigned long lpos, dummy, *furrfu = &lpos;
 465         int uni_xlate = sbi->options.unicode_xlate;
 466         int isvfat = sbi->options.isvfat;
 467         int utf8 = sbi->options.utf8;
 468         int nocase = sbi->options.nocase;
 469         unsigned short opt_shortname = sbi->options.shortname;
 470         unsigned long inum;
 471         int chi, chl, i, i2, j, last, last_u, dotoffset = 0;
 472         loff_t cpos;
 473         int ret = 0;
 474
 475         lock_super(sb);
 476
 477         cpos = filp->f_pos;
 478         /* Fake . and .. for the root directory. */
 479         if (inode->i_ino == MSDOS_ROOT_INO) {
 480                 while (cpos < 2) {
 481                         if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
 482                                 goto out;
 483                         cpos++;
 484                         filp->f_pos++;
 485                 }
 486                 if (cpos == 2) {
 487                         dummy = 2;
 488                         furrfu = &dummy;
 489                         cpos = 0;
 490                 }
 491         }
 492         if (cpos & (sizeof(struct msdos_dir_entry)-1)) {
 493                 ret = -ENOENT;
 494                 goto out;
 495         }
 496
 497         bh = NULL;
 498 GetNew:
 499         if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
 500                 goto EODir;
 501 parse_record:
 502         long_slots = 0;
 503         /* Check for long filename entry */
 504         if (isvfat) {
 505                 if (de->name[0] == DELETED_FLAG)
 506                         goto RecEnd;
 507                 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
 508                         goto RecEnd;
 509                 if (de->attr != ATTR_EXT && IS_FREE(de->name))
 510                         goto RecEnd;
 511         } else {
 512                 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
 513                         goto RecEnd;
 514         }
 515
 516         if (isvfat && de->attr == ATTR_EXT) {
 517                 int status = fat_parse_long(inode, &cpos, &bh, &de,
 518                                             &unicode, &long_slots);
 519                 if (status < 0) {
 520                         filp->f_pos = cpos;
 521                         ret = status;
 522                         goto out;
 523                 } else if (status == PARSE_INVALID)
 524                         goto RecEnd;
 525                 else if (status == PARSE_NOT_LONGNAME)
 526                         goto parse_record;
 527                 else if (status == PARSE_EOF)
 528                         goto EODir;
 529         }
 530
 531         if (sbi->options.dotsOK) {
 532                 ptname = bufname;
 533                 dotoffset = 0;
 534                 if (de->attr & ATTR_HIDDEN) {
 535                         *ptname++ = '.';
 536                         dotoffset = 1;
 537                 }
 538         }
 539
 540         memcpy(work, de->name, sizeof(de->name));
 541         /* see namei.c, msdos_format_name */
 542         if (work[0] == 0x05)
 543                 work[0] = 0xE5;
 544         for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
 545                 if (!(c = work[i]))
 546                         break;
 547                 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
 548                                         &bufuname[j++], opt_shortname,
 549                                         de->lcase & CASE_LOWER_BASE);
 550                 if (chl <= 1) {
 551                         ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
 552                         if (c != ' ') {
 553                                 last = i;
 554                                 last_u = j;
 555                         }
 556                 } else {
 557                         last_u = j;
 558                         for (chi = 0; chi < chl && i < 8; chi++) {
 559                                 ptname[i] = work[i];
 560                                 i++; last = i;
 561                         }
 562                 }
 563         }
 564         i = last;
 565         j = last_u;
 566         fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
 567         ptname[i++] = '.';
 568         for (i2 = 8; i2 < MSDOS_NAME;) {
 569                 if (!(c = work[i2]))
 570                         break;
 571                 chl = fat_shortname2uni(nls_disk, &work[i2], MSDOS_NAME - i2,
 572                                         &bufuname[j++], opt_shortname,
 573                                         de->lcase & CASE_LOWER_EXT);
 574                 if (chl <= 1) {
 575                         i2++;
 576                         ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
 577                         if (c != ' ') {
 578                                 last = i;
 579                                 last_u = j;
 580                         }
 581                 } else {
 582                         last_u = j;
 583                         for (chi = 0; chi < chl && i2 < MSDOS_NAME; chi++) {
 584                                 ptname[i++] = work[i2++];
 585                                 last = i;
 586                         }
 587                 }
 588         }
 589         if (!last)
 590                 goto RecEnd;
 591
 592         i = last + dotoffset;
 593         j = last_u;
 594
 595         lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry);
 596         if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
 597                 inum = inode->i_ino;
 598         else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 599                 inum = parent_ino(filp->f_path.dentry);
 600         } else {
 601                 loff_t i_pos = fat_make_i_pos(sb, bh, de);
 602                 struct inode *tmp = fat_iget(sb, i_pos);
 603                 if (tmp) {
 604                         inum = tmp->i_ino;
 605                         iput(tmp);
 606                 } else
 607                         inum = iunique(sb, MSDOS_ROOT_INO);
 608         }
 609
 610         if (isvfat) {
 611                 bufuname[j] = 0x0000;
 612                 i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname))
 613                          : uni16_to_x8(bufname, bufuname, sizeof(bufname), uni_xlate, nls_io);
 614         }
 615
 616         fill_name = bufname;
 617         fill_len = i;
 618         if (!short_only && long_slots) {
 619                 /* convert the unicode long name. 261 is maximum size
 620                  * of unicode buffer. (13 * slots + nul) */
 621                 void *longname = unicode + 261;
 622                 int buf_size = PATH_MAX - (261 * sizeof(unicode[0]));
 623                 int long_len = utf8
 624                         ? utf8_wcstombs(longname, unicode, buf_size)
 625                         : uni16_to_x8(longname, unicode, buf_size, uni_xlate, nls_io);
 626
 627                 if (!both) {
 628                         fill_name = longname;
 629                         fill_len = long_len;
 630                 } else {
 631                         /* hack for fat_ioctl_filldir() */
 632                         struct fat_ioctl_filldir_callback *p = dirent;
 633
 634                         p->longname = longname;
 635                         p->long_len = long_len;
 636                         p->shortname = bufname;
 637                         p->short_len = i;
 638                         fill_name = NULL;
 639                         fill_len = 0;
 640                 }
 641         }
 642         if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
 643                     (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
 644                 goto FillFailed;
 645
 646 RecEnd:
 647         furrfu = &lpos;
 648         filp->f_pos = cpos;
 649         goto GetNew;
 650 EODir:
 651         filp->f_pos = cpos;
 652 FillFailed:
 653         brelse(bh);
 654         if (unicode)
 655                 __putname(unicode);
 656 out:
 657         unlock_super(sb);
 658         return ret;
 659 }
 660
 661 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
 662 {
 663         struct inode *inode = filp->f_path.dentry->d_inode;
 664         return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
 665 }
 666
 667 #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type)                          \
 668 static int func(void *__buf, const char *name, int name_len,               \
 669                              loff_t offset, u64 ino, unsigned int d_type)  \
 670 {                                                                          \
 671         struct fat_ioctl_filldir_callback *buf = __buf;                    \
 672         struct dirent_type __user *d1 = buf->dirent;                       \
 673         struct dirent_type __user *d2 = d1 + 1;                            \
 674                                                                            \
 675         if (buf->result)                                                   \
 676                 return -EINVAL;                                            \
 677         buf->result++;                                                     \
 678                                                                            \
 679         if (name != NULL) {                                                \
 680                 /* dirent has only short name */                           \
 681                 if (name_len >= sizeof(d1->d_name))                        \
 682                         name_len = sizeof(d1->d_name) - 1;                 \
 683                                                                            \
 684                 if (put_user(0, d2->d_name)                     ||         \
 685                     put_user(0, &d2->d_reclen)                  ||         \
 686                     copy_to_user(d1->d_name, name, name_len)    ||         \
 687                     put_user(0, d1->d_name + name_len)          ||         \
 688                     put_user(name_len, &d1->d_reclen))                     \
 689                         goto efault;                                       \
 690         } else {                                                           \
 691                 /* dirent has short and long name */                       \
 692                 const char *longname = buf->longname;                      \
 693                 int long_len = buf->long_len;                              \
 694                 const char *shortname = buf->shortname;                    \
 695                 int short_len = buf->short_len;                            \
 696                                                                            \
 697                 if (long_len >= sizeof(d1->d_name))                        \
 698                         long_len = sizeof(d1->d_name) - 1;                 \
 699                 if (short_len >= sizeof(d1->d_name))                       \
 700                         short_len = sizeof(d1->d_name) - 1;                \
 701                                                                            \
 702                 if (copy_to_user(d2->d_name, longname, long_len)        || \
 703                     put_user(0, d2->d_name + long_len)                  || \
 704                     put_user(long_len, &d2->d_reclen)                   || \
 705                     put_user(ino, &d2->d_ino)                           || \
 706                     put_user(offset, &d2->d_off)                        || \
 707                     copy_to_user(d1->d_name, shortname, short_len)      || \
 708                     put_user(0, d1->d_name + short_len)                 || \
 709                     put_user(short_len, &d1->d_reclen))                    \
 710                         goto efault;                                       \
 711         }                                                                  \
 712         return 0;                                                          \
 713 efault:                                                                    \
 714         buf->result = -EFAULT;                                             \
 715         return -EFAULT;                                                    \
 716 }
 717
 718 FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, dirent)
 719
 720 static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
 721                              void __user *dirent, filldir_t filldir,
 722                              int short_only, int both)
 723 {
 724         struct fat_ioctl_filldir_callback buf;
 725         int ret;
 726
 727         buf.dirent = dirent;
 728         buf.result = 0;
 729         mutex_lock(&inode->i_mutex);
 730         ret = -ENOENT;
 731         if (!IS_DEADDIR(inode)) {
 732                 ret = __fat_readdir(inode, filp, &buf, filldir,
 733                                     short_only, both);
 734         }
 735         mutex_unlock(&inode->i_mutex);
 736         if (ret >= 0)
 737                 ret = buf.result;
 738         return ret;
 739 }
 740
 741 static int fat_dir_ioctl(struct inode *inode, struct file *filp,
 742                          unsigned int cmd, unsigned long arg)
 743 {
 744         struct dirent __user *d1 = (struct dirent __user *)arg;
 745         int short_only, both;
 746
 747         switch (cmd) {
 748         case VFAT_IOCTL_READDIR_SHORT:
 749                 short_only = 1;
 750                 both = 0;
 751                 break;
 752         case VFAT_IOCTL_READDIR_BOTH:
 753                 short_only = 0;
 754                 both = 1;
 755                 break;
 756         default:
 757                 return fat_generic_ioctl(inode, filp, cmd, arg);
 758         }
 759
 760         if (!access_ok(VERIFY_WRITE, d1, sizeof(struct dirent[2])))
 761                 return -EFAULT;
 762         /*
 763          * Yes, we don't need this put_user() absolutely. However old
 764          * code didn't return the right value. So, app use this value,
 765          * in order to check whether it is EOF.
 766          */
 767         if (put_user(0, &d1->d_reclen))
 768                 return -EFAULT;
 769
 770         return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
 771                                  short_only, both);
 772 }
 773
 774 #ifdef CONFIG_COMPAT
 775 #define VFAT_IOCTL_READDIR_BOTH32       _IOR('r', 1, struct compat_dirent[2])
 776 #define VFAT_IOCTL_READDIR_SHORT32      _IOR('r', 2, struct compat_dirent[2])
 777
 778 FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
 779
 780 static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
 781                                  unsigned long arg)
 782 {
 783         struct inode *inode = filp->f_path.dentry->d_inode;
 784         struct compat_dirent __user *d1 = compat_ptr(arg);
 785         int short_only, both;
 786
 787         switch (cmd) {
 788         case VFAT_IOCTL_READDIR_SHORT32:
 789                 short_only = 1;
 790                 both = 0;
 791                 break;
 792         case VFAT_IOCTL_READDIR_BOTH32:
 793                 short_only = 0;
 794                 both = 1;
 795                 break;
 796         default:
 797                 return -ENOIOCTLCMD;
 798         }
 799
 800         if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
 801                 return -EFAULT;
 802         /*
 803          * Yes, we don't need this put_user() absolutely. However old
 804          * code didn't return the right value. So, app use this value,
 805          * in order to check whether it is EOF.
 806          */
 807         if (put_user(0, &d1->d_reclen))
 808                 return -EFAULT;
 809
 810         return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
 811                                  short_only, both);
 812 }
 813 #endif /* CONFIG_COMPAT */
 814
 815 const struct file_operations fat_dir_operations = {
 816         .read           = generic_read_dir,
 817         .readdir        = fat_readdir,
 818         .ioctl          = fat_dir_ioctl,
 819 #ifdef CONFIG_COMPAT
 820         .compat_ioctl   = fat_compat_dir_ioctl,
 821 #endif
 822         .fsync          = file_fsync,
 823 };
 824
 825 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
 826                                struct buffer_head **bh,
 827                                struct msdos_dir_entry **de)
 828 {
 829         while (fat_get_entry(dir, pos, bh, de) >= 0) {
 830                 /* free entry or long name entry or volume label */
 831                 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
 832                         return 0;
 833         }
 834         return -ENOENT;
 835 }
 836
 837 /*
 838  * The ".." entry can not provide the "struct fat_slot_info" informations
 839  * for inode. So, this function provide the some informations only.
 840  */
 841 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
 842                          struct msdos_dir_entry **de, loff_t *i_pos)
 843 {
 844         loff_t offset;
 845
 846         offset = 0;
 847         *bh = NULL;
 848         while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
 849                 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 850                         *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
 851                         return 0;
 852                 }
 853         }
 854         return -ENOENT;
 855 }
 856
 857 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
 858
 859 /* See if directory is empty */
 860 int fat_dir_empty(struct inode *dir)
 861 {
 862         struct buffer_head *bh;
 863         struct msdos_dir_entry *de;
 864         loff_t cpos;
 865         int result = 0;
 866
 867         bh = NULL;
 868         cpos = 0;
 869         while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
 870                 if (strncmp(de->name, MSDOS_DOT   , MSDOS_NAME) &&
 871                     strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 872                         result = -ENOTEMPTY;
 873                         break;
 874                 }
 875         }
 876         brelse(bh);
 877         return result;
 878 }
 879
 880 EXPORT_SYMBOL_GPL(fat_dir_empty);
 881
 882 /*
 883  * fat_subdirs counts the number of sub-directories of dir. It can be run
 884  * on directories being created.
 885  */
 886 int fat_subdirs(struct inode *dir)
 887 {
 888         struct buffer_head *bh;
 889         struct msdos_dir_entry *de;
 890         loff_t cpos;
 891         int count = 0;
 892
 893         bh = NULL;
 894         cpos = 0;
 895         while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
 896                 if (de->attr & ATTR_DIR)
 897                         count++;
 898         }
 899         brelse(bh);
 900         return count;
 901 }
 902
 903 /*
 904  * Scans a directory for a given file (name points to its formatted name).
 905  * Returns an error code or zero.
 906  */
 907 int fat_scan(struct inode *dir, const unsigned char *name,
 908              struct fat_slot_info *sinfo)
 909 {
 910         struct super_block *sb = dir->i_sb;
 911
 912         sinfo->slot_off = 0;
 913         sinfo->bh = NULL;
 914         while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
 915                                    &sinfo->de) >= 0) {
 916                 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
 917                         sinfo->slot_off -= sizeof(*sinfo->de);
 918                         sinfo->nr_slots = 1;
 919                         sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
 920                         return 0;
 921                 }
 922         }
 923         return -ENOENT;
 924 }
 925
 926 EXPORT_SYMBOL_GPL(fat_scan);
 927
 928 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
 929 {
 930         struct super_block *sb = dir->i_sb;
 931         struct buffer_head *bh;
 932         struct msdos_dir_entry *de, *endp;
 933         int err = 0, orig_slots;
 934
 935         while (nr_slots) {
 936                 bh = NULL;
 937                 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
 938                         err = -EIO;
 939                         break;
 940                 }
 941
 942                 orig_slots = nr_slots;
 943                 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
 944                 while (nr_slots && de < endp) {
 945                         de->name[0] = DELETED_FLAG;
 946                         de++;
 947                         nr_slots--;
 948                 }
 949                 mark_buffer_dirty(bh);
 950                 if (IS_DIRSYNC(dir))
 951                         err = sync_dirty_buffer(bh);
 952                 brelse(bh);
 953                 if (err)
 954                         break;
 955
 956                 /* pos is *next* de's position, so this does `- sizeof(de)' */
 957                 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
 958         }
 959
 960         return err;
 961 }
 962
 963 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
 964 {
 965         struct msdos_dir_entry *de;
 966         struct buffer_head *bh;
 967         int err = 0, nr_slots;
 968
 969         /*
 970          * First stage: Remove the shortname. By this, the directory
 971          * entry is removed.
 972          */
 973         nr_slots = sinfo->nr_slots;
 974         de = sinfo->de;
 975         sinfo->de = NULL;
 976         bh = sinfo->bh;
 977         sinfo->bh = NULL;
 978         while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
 979                 de->name[0] = DELETED_FLAG;
 980                 de--;
 981                 nr_slots--;
 982         }
 983         mark_buffer_dirty(bh);
 984         if (IS_DIRSYNC(dir))
 985                 err = sync_dirty_buffer(bh);
 986         brelse(bh);
 987         if (err)
 988                 return err;
 989         dir->i_version++;
 990
 991         if (nr_slots) {
 992                 /*
 993                  * Second stage: remove the remaining longname slots.
 994                  * (This directory entry is already removed, and so return
 995                  * the success)
 996                  */
 997                 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
 998                 if (err) {
 999                         printk(KERN_WARNING
1000                                "FAT: Couldn't remove the long name slots\n");
1001                 }
1002         }
1003
1004         dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
1005         if (IS_DIRSYNC(dir))
1006                 (void)fat_sync_inode(dir);
1007         else
1008                 mark_inode_dirty(dir);
1009
1010         return 0;
1011 }
1012
1013 EXPORT_SYMBOL_GPL(fat_remove_entries);
1014
1015 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1016                               struct buffer_head **bhs, int nr_bhs)
1017 {
1018         struct super_block *sb = dir->i_sb;
1019         sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1020         int err, i, n;
1021
1022         /* Zeroing the unused blocks on this cluster */
1023         blknr += nr_used;
1024         n = nr_used;
1025         while (blknr < last_blknr) {
1026                 bhs[n] = sb_getblk(sb, blknr);
1027                 if (!bhs[n]) {
1028                         err = -ENOMEM;
1029                         goto error;
1030                 }
1031                 memset(bhs[n]->b_data, 0, sb->s_blocksize);
1032                 set_buffer_uptodate(bhs[n]);
1033                 mark_buffer_dirty(bhs[n]);
1034
1035                 n++;
1036                 blknr++;
1037                 if (n == nr_bhs) {
1038                         if (IS_DIRSYNC(dir)) {
1039                                 err = fat_sync_bhs(bhs, n);
1040                                 if (err)
1041                                         goto error;
1042                         }
1043                         for (i = 0; i < n; i++)
1044                                 brelse(bhs[i]);
1045                         n = 0;
1046                 }
1047         }
1048         if (IS_DIRSYNC(dir)) {
1049                 err = fat_sync_bhs(bhs, n);
1050                 if (err)
1051                         goto error;
1052         }
1053         for (i = 0; i < n; i++)
1054                 brelse(bhs[i]);
1055
1056         return 0;
1057
1058 error:
1059         for (i = 0; i < n; i++)
1060                 bforget(bhs[i]);
1061         return err;
1062 }
1063
1064 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1065 {
1066         struct super_block *sb = dir->i_sb;
1067         struct msdos_sb_info *sbi = MSDOS_SB(sb);
1068         struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1069         struct msdos_dir_entry *de;
1070         sector_t blknr;
1071         __le16 date, time;
1072         int err, cluster;
1073
1074         err = fat_alloc_clusters(dir, &cluster, 1);
1075         if (err)
1076                 goto error;
1077
1078         blknr = fat_clus_to_blknr(sbi, cluster);
1079         bhs[0] = sb_getblk(sb, blknr);
1080         if (!bhs[0]) {
1081                 err = -ENOMEM;
1082                 goto error_free;
1083         }
1084
1085         fat_date_unix2dos(ts->tv_sec, &time, &date);
1086
1087         de = (struct msdos_dir_entry *)bhs[0]->b_data;
1088         /* filling the new directory slots ("." and ".." entries) */
1089         memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1090         memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1091         de->attr = de[1].attr = ATTR_DIR;
1092         de[0].lcase = de[1].lcase = 0;
1093         de[0].time = de[1].time = time;
1094         de[0].date = de[1].date = date;
1095         de[0].ctime_cs = de[1].ctime_cs = 0;
1096         if (sbi->options.isvfat) {
1097                 /* extra timestamps */
1098                 de[0].ctime = de[1].ctime = time;
1099                 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1100         } else {
1101                 de[0].ctime = de[1].ctime = 0;
1102                 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1103         }
1104         de[0].start = cpu_to_le16(cluster);
1105         de[0].starthi = cpu_to_le16(cluster >> 16);
1106         de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
1107         de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
1108         de[0].size = de[1].size = 0;
1109         memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1110         set_buffer_uptodate(bhs[0]);
1111         mark_buffer_dirty(bhs[0]);
1112
1113         err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1114         if (err)
1115                 goto error_free;
1116
1117         return cluster;
1118
1119 error_free:
1120         fat_free_clusters(dir, cluster);
1121 error:
1122         return err;
1123 }
1124
1125 EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1126
1127 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1128                                int *nr_cluster, struct msdos_dir_entry **de,
1129                                struct buffer_head **bh, loff_t *i_pos)
1130 {
1131         struct super_block *sb = dir->i_sb;
1132         struct msdos_sb_info *sbi = MSDOS_SB(sb);
1133         struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1134         sector_t blknr, start_blknr, last_blknr;
1135         unsigned long size, copy;
1136         int err, i, n, offset, cluster[2];
1137
1138         /*
1139          * The minimum cluster size is 512bytes, and maximum entry
1140          * size is 32*slots (672bytes).  So, iff the cluster size is
1141          * 512bytes, we may need two clusters.
1142          */
1143         size = nr_slots * sizeof(struct msdos_dir_entry);
1144         *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1145         BUG_ON(*nr_cluster > 2);
1146
1147         err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1148         if (err)
1149                 goto error;
1150
1151         /*
1152          * First stage: Fill the directory entry.  NOTE: This cluster
1153          * is not referenced from any inode yet, so updates order is
1154          * not important.
1155          */
1156         i = n = copy = 0;
1157         do {
1158                 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1159                 last_blknr = start_blknr + sbi->sec_per_clus;
1160                 while (blknr < last_blknr) {
1161                         bhs[n] = sb_getblk(sb, blknr);
1162                         if (!bhs[n]) {
1163                                 err = -ENOMEM;
1164                                 goto error_nomem;
1165                         }
1166
1167                         /* fill the directory entry */
1168                         copy = min(size, sb->s_blocksize);
1169                         memcpy(bhs[n]->b_data, slots, copy);
1170                         slots += copy;
1171                         size -= copy;
1172                         set_buffer_uptodate(bhs[n]);
1173                         mark_buffer_dirty(bhs[n]);
1174                         if (!size)
1175                                 break;
1176                         n++;
1177                         blknr++;
1178                 }
1179         } while (++i < *nr_cluster);
1180
1181         memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1182         offset = copy - sizeof(struct msdos_dir_entry);
1183         get_bh(bhs[n]);
1184         *bh = bhs[n];
1185         *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1186         *i_pos = fat_make_i_pos(sb, *bh, *de);
1187
1188         /* Second stage: clear the rest of cluster, and write outs */
1189         err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1190         if (err)
1191                 goto error_free;
1192
1193         return cluster[0];
1194
1195 error_free:
1196         brelse(*bh);
1197         *bh = NULL;
1198         n = 0;
1199 error_nomem:
1200         for (i = 0; i < n; i++)
1201                 bforget(bhs[i]);
1202         fat_free_clusters(dir, cluster[0]);
1203 error:
1204         return err;
1205 }
1206
1207 int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1208                     struct fat_slot_info *sinfo)
1209 {
1210         struct super_block *sb = dir->i_sb;
1211         struct msdos_sb_info *sbi = MSDOS_SB(sb);
1212         struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1213         struct msdos_dir_entry *de;
1214         int err, free_slots, i, nr_bhs;
1215         loff_t pos, i_pos;
1216
1217         sinfo->nr_slots = nr_slots;
1218
1219         /* First stage: search free direcotry entries */
1220         free_slots = nr_bhs = 0;
1221         bh = prev = NULL;
1222         pos = 0;
1223         err = -ENOSPC;
1224         while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1225                 /* check the maximum size of directory */
1226                 if (pos >= FAT_MAX_DIR_SIZE)
1227                         goto error;
1228
1229                 if (IS_FREE(de->name)) {
1230                         if (prev != bh) {
1231                                 get_bh(bh);
1232                                 bhs[nr_bhs] = prev = bh;
1233                                 nr_bhs++;
1234                         }
1235                         free_slots++;
1236                         if (free_slots == nr_slots)
1237                                 goto found;
1238                 } else {
1239                         for (i = 0; i < nr_bhs; i++)
1240                                 brelse(bhs[i]);
1241                         prev = NULL;
1242                         free_slots = nr_bhs = 0;
1243                 }
1244         }
1245         if (dir->i_ino == MSDOS_ROOT_INO) {
1246                 if (sbi->fat_bits != 32)
1247                         goto error;
1248         } else if (MSDOS_I(dir)->i_start == 0) {
1249                 printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
1250                        MSDOS_I(dir)->i_pos);
1251                 err = -EIO;
1252                 goto error;
1253         }
1254
1255 found:
1256         err = 0;
1257         pos -= free_slots * sizeof(*de);
1258         nr_slots -= free_slots;
1259         if (free_slots) {
1260                 /*
1261                  * Second stage: filling the free entries with new entries.
1262                  * NOTE: If this slots has shortname, first, we write
1263                  * the long name slots, then write the short name.
1264                  */
1265                 int size = free_slots * sizeof(*de);
1266                 int offset = pos & (sb->s_blocksize - 1);
1267                 int long_bhs = nr_bhs - (nr_slots == 0);
1268
1269                 /* Fill the long name slots. */
1270                 for (i = 0; i < long_bhs; i++) {
1271                         int copy = min_t(int, sb->s_blocksize - offset, size);
1272                         memcpy(bhs[i]->b_data + offset, slots, copy);
1273                         mark_buffer_dirty(bhs[i]);
1274                         offset = 0;
1275                         slots += copy;
1276                         size -= copy;
1277                 }
1278                 if (long_bhs && IS_DIRSYNC(dir))
1279                         err = fat_sync_bhs(bhs, long_bhs);
1280                 if (!err && i < nr_bhs) {
1281                         /* Fill the short name slot. */
1282                         int copy = min_t(int, sb->s_blocksize - offset, size);
1283                         memcpy(bhs[i]->b_data + offset, slots, copy);
1284                         mark_buffer_dirty(bhs[i]);
1285                         if (IS_DIRSYNC(dir))
1286                                 err = sync_dirty_buffer(bhs[i]);
1287                 }
1288                 for (i = 0; i < nr_bhs; i++)
1289                         brelse(bhs[i]);
1290                 if (err)
1291                         goto error_remove;
1292         }
1293
1294         if (nr_slots) {
1295                 int cluster, nr_cluster;
1296
1297                 /*
1298                  * Third stage: allocate the cluster for new entries.
1299                  * And initialize the cluster with new entries, then
1300                  * add the cluster to dir.
1301                  */
1302                 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1303                                               &de, &bh, &i_pos);
1304                 if (cluster < 0) {
1305                         err = cluster;
1306                         goto error_remove;
1307                 }
1308                 err = fat_chain_add(dir, cluster, nr_cluster);
1309                 if (err) {
1310                         fat_free_clusters(dir, cluster);
1311                         goto error_remove;
1312                 }
1313                 if (dir->i_size & (sbi->cluster_size - 1)) {
1314                         fat_fs_panic(sb, "Odd directory size");
1315                         dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1316                                 & ~((loff_t)sbi->cluster_size - 1);
1317                 }
1318                 dir->i_size += nr_cluster << sbi->cluster_bits;
1319                 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1320         }
1321         sinfo->slot_off = pos;
1322         sinfo->de = de;
1323         sinfo->bh = bh;
1324         sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1325
1326         return 0;
1327
1328 error:
1329         brelse(bh);
1330         for (i = 0; i < nr_bhs; i++)
1331                 brelse(bhs[i]);
1332         return err;
1333
1334 error_remove:
1335         brelse(bh);
1336         if (free_slots)
1337                 __fat_remove_entries(dir, pos, free_slots);
1338         return err;
1339 }
1340
1341 EXPORT_SYMBOL_GPL(fat_add_entries);