fs/msdos/namei.c

   1 /*
   2  *  linux/fs/msdos/namei.c
   3  *
   4  *  Written 1992,1993 by Werner Almesberger
   5  *  Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
   6  *  Rewritten for constant inumbers 1999 by Al Viro
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/time.h>
  11 #include <linux/buffer_head.h>
  12 #include <linux/msdos_fs.h>
  13 #include <linux/smp_lock.h>
  14
  15 /* MS-DOS "device special files" */
  16 static const unsigned char *reserved_names[] = {
  17         "CON     ", "PRN     ", "NUL     ", "AUX     ",
  18         "LPT1    ", "LPT2    ", "LPT3    ", "LPT4    ",
  19         "COM1    ", "COM2    ", "COM3    ", "COM4    ",
  20         NULL
  21 };
  22
  23 /* Characters that are undesirable in an MS-DOS file name */
  24 static unsigned char bad_chars[] = "*?<>|\"";
  25 static unsigned char bad_if_strict_pc[] = "+=,; ";
  26 /* GEMDOS is less restrictive */
  27 static unsigned char bad_if_strict_atari[] = " ";
  28
  29 #define bad_if_strict(opts) \
  30         ((opts)->atari ? bad_if_strict_atari : bad_if_strict_pc)
  31
  32 /***** Formats an MS-DOS file name. Rejects invalid names. */
  33 static int msdos_format_name(const unsigned char *name, int len,
  34                              unsigned char *res, struct fat_mount_options *opts)
  35         /*
  36          * name is the proposed name, len is its length, res is
  37          * the resulting name, opts->name_check is either (r)elaxed,
  38          * (n)ormal or (s)trict, opts->dotsOK allows dots at the
  39          * beginning of name (for hidden files)
  40          */
  41 {
  42         unsigned char *walk;
  43         const unsigned char **reserved;
  44         unsigned char c;
  45         int space;
  46
  47         if (name[0] == '.') {   /* dotfile because . and .. already done */
  48                 if (opts->dotsOK) {
  49                         /* Get rid of dot - test for it elsewhere */
  50                         name++;
  51                         len--;
  52                 } else if (!opts->atari)
  53                         return -EINVAL;
  54         }
  55         /*
  56          * disallow names that _really_ start with a dot for MS-DOS,
  57          * GEMDOS does not care
  58          */
  59         space = !opts->atari;
  60         c = 0;
  61         for (walk = res; len && walk - res < 8; walk++) {
  62                 c = *name++;
  63                 len--;
  64                 if (opts->name_check != 'r' && strchr(bad_chars, c))
  65                         return -EINVAL;
  66                 if (opts->name_check == 's' && strchr(bad_if_strict(opts), c))
  67                         return -EINVAL;
  68                 if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
  69                         return -EINVAL;
  70                 if (c < ' ' || c == ':' || c == '\\')
  71                         return -EINVAL;
  72         /*
  73          * 0xE5 is legal as a first character, but we must substitute
  74          * 0x05 because 0xE5 marks deleted files.  Yes, DOS really
  75          * does this.
  76          * It seems that Microsoft hacked DOS to support non-US
  77          * characters after the 0xE5 character was already in use to
  78          * mark deleted files.
  79          */
  80                 if ((res == walk) && (c == 0xE5))
  81                         c = 0x05;
  82                 if (c == '.')
  83                         break;
  84                 space = (c == ' ');
  85                 *walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
  86         }
  87         if (space)
  88                 return -EINVAL;
  89         if (opts->name_check == 's' && len && c != '.') {
  90                 c = *name++;
  91                 len--;
  92                 if (c != '.')
  93                         return -EINVAL;
  94         }
  95         while (c != '.' && len--)
  96                 c = *name++;
  97         if (c == '.') {
  98                 while (walk - res < 8)
  99                         *walk++ = ' ';
 100                 while (len > 0 && walk - res < MSDOS_NAME) {
 101                         c = *name++;
 102                         len--;
 103                         if (opts->name_check != 'r' && strchr(bad_chars, c))
 104                                 return -EINVAL;
 105                         if (opts->name_check == 's' &&
 106                             strchr(bad_if_strict(opts), c))
 107                                 return -EINVAL;
 108                         if (c < ' ' || c == ':' || c == '\\')
 109                                 return -EINVAL;
 110                         if (c == '.') {
 111                                 if (opts->name_check == 's')
 112                                         return -EINVAL;
 113                                 break;
 114                         }
 115                         if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
 116                                 return -EINVAL;
 117                         space = c == ' ';
 118                         if (!opts->nocase && c >= 'a' && c <= 'z')
 119                                 *walk++ = c - 32;
 120                         else
 121                                 *walk++ = c;
 122                 }
 123                 if (space)
 124                         return -EINVAL;
 125                 if (opts->name_check == 's' && len)
 126                         return -EINVAL;
 127         }
 128         while (walk - res < MSDOS_NAME)
 129                 *walk++ = ' ';
 130         if (!opts->atari)
 131                 /* GEMDOS is less stupid and has no reserved names */
 132                 for (reserved = reserved_names; *reserved; reserved++)
 133                         if (!strncmp(res, *reserved, 8))
 134                                 return -EINVAL;
 135         return 0;
 136 }
 137
 138 /***** Locates a directory entry.  Uses unformatted name. */
 139 static int msdos_find(struct inode *dir, const unsigned char *name, int len,
 140                       struct fat_slot_info *sinfo)
 141 {
 142         struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 143         unsigned char msdos_name[MSDOS_NAME];
 144         int err;
 145
 146         err = msdos_format_name(name, len, msdos_name, &sbi->options);
 147         if (err)
 148                 return -ENOENT;
 149
 150         err = fat_scan(dir, msdos_name, sinfo);
 151         if (!err && sbi->options.dotsOK) {
 152                 if (name[0] == '.') {
 153                         if (!(sinfo->de->attr & ATTR_HIDDEN))
 154                                 err = -ENOENT;
 155                 } else {
 156                         if (sinfo->de->attr & ATTR_HIDDEN)
 157                                 err = -ENOENT;
 158                 }
 159                 if (err)
 160                         brelse(sinfo->bh);
 161         }
 162         return err;
 163 }
 164
 165 /*
 166  * Compute the hash for the msdos name corresponding to the dentry.
 167  * Note: if the name is invalid, we leave the hash code unchanged so
 168  * that the existing dentry can be used. The msdos fs routines will
 169  * return ENOENT or EINVAL as appropriate.
 170  */
 171 static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
 172 {
 173         struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
 174         unsigned char msdos_name[MSDOS_NAME];
 175         int error;
 176
 177         error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
 178         if (!error)
 179                 qstr->hash = full_name_hash(msdos_name, MSDOS_NAME);
 180         return 0;
 181 }
 182
 183 /*
 184  * Compare two msdos names. If either of the names are invalid,
 185  * we fall back to doing the standard name comparison.
 186  */
 187 static int msdos_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
 188 {
 189         struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
 190         unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
 191         int error;
 192
 193         error = msdos_format_name(a->name, a->len, a_msdos_name, options);
 194         if (error)
 195                 goto old_compare;
 196         error = msdos_format_name(b->name, b->len, b_msdos_name, options);
 197         if (error)
 198                 goto old_compare;
 199         error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
 200 out:
 201         return error;
 202
 203 old_compare:
 204         error = 1;
 205         if (a->len == b->len)
 206                 error = memcmp(a->name, b->name, a->len);
 207         goto out;
 208 }
 209
 210 static struct dentry_operations msdos_dentry_operations = {
 211         .d_hash         = msdos_hash,
 212         .d_compare      = msdos_cmp,
 213 };
 214
 215 /*
 216  * AV. Wrappers for FAT sb operations. Is it wise?
 217  */
 218
 219 /***** Get inode using directory and name */
 220 static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry,
 221                                    struct nameidata *nd)
 222 {
 223         struct super_block *sb = dir->i_sb;
 224         struct fat_slot_info sinfo;
 225         struct inode *inode = NULL;
 226         int res;
 227
 228         dentry->d_op = &msdos_dentry_operations;
 229
 230         lock_kernel();
 231         res = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 232         if (res == -ENOENT)
 233                 goto add;
 234         if (res < 0)
 235                 goto out;
 236         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 237         brelse(sinfo.bh);
 238         if (IS_ERR(inode)) {
 239                 res = PTR_ERR(inode);
 240                 goto out;
 241         }
 242 add:
 243         res = 0;
 244         dentry = d_splice_alias(inode, dentry);
 245         if (dentry)
 246                 dentry->d_op = &msdos_dentry_operations;
 247 out:
 248         unlock_kernel();
 249         if (!res)
 250                 return dentry;
 251         return ERR_PTR(res);
 252 }
 253
 254 /***** Creates a directory entry (name is already formatted). */
 255 static int msdos_add_entry(struct inode *dir, const unsigned char *name,
 256                            int is_dir, int is_hid, int cluster,
 257                            struct timespec *ts, struct fat_slot_info *sinfo)
 258 {
 259         struct msdos_dir_entry de;
 260         __le16 time, date;
 261         int err;
 262
 263         memcpy(de.name, name, MSDOS_NAME);
 264         de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
 265         if (is_hid)
 266                 de.attr |= ATTR_HIDDEN;
 267         de.lcase = 0;
 268         fat_date_unix2dos(ts->tv_sec, &time, &date);
 269         de.cdate = de.adate = 0;
 270         de.ctime = 0;
 271         de.ctime_cs = 0;
 272         de.time = time;
 273         de.date = date;
 274         de.start = cpu_to_le16(cluster);
 275         de.starthi = cpu_to_le16(cluster >> 16);
 276         de.size = 0;
 277
 278         err = fat_add_entries(dir, &de, 1, sinfo);
 279         if (err)
 280                 return err;
 281
 282         dir->i_ctime = dir->i_mtime = *ts;
 283         if (IS_DIRSYNC(dir))
 284                 (void)fat_sync_inode(dir);
 285         else
 286                 mark_inode_dirty(dir);
 287
 288         return 0;
 289 }
 290
 291 /***** Create a file */
 292 static int msdos_create(struct inode *dir, struct dentry *dentry, int mode,
 293                         struct nameidata *nd)
 294 {
 295         struct super_block *sb = dir->i_sb;
 296         struct inode *inode;
 297         struct fat_slot_info sinfo;
 298         struct timespec ts;
 299         unsigned char msdos_name[MSDOS_NAME];
 300         int err, is_hid;
 301
 302         lock_kernel();
 303
 304         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 305                                 msdos_name, &MSDOS_SB(sb)->options);
 306         if (err)
 307                 goto out;
 308         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 309         /* Have to do it due to foo vs. .foo conflicts */
 310         if (!fat_scan(dir, msdos_name, &sinfo)) {
 311                 brelse(sinfo.bh);
 312                 err = -EINVAL;
 313                 goto out;
 314         }
 315
 316         ts = CURRENT_TIME_SEC;
 317         err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
 318         if (err)
 319                 goto out;
 320         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 321         brelse(sinfo.bh);
 322         if (IS_ERR(inode)) {
 323                 err = PTR_ERR(inode);
 324                 goto out;
 325         }
 326         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 327         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 328
 329         d_instantiate(dentry, inode);
 330 out:
 331         unlock_kernel();
 332         return err;
 333 }
 334
 335 /***** Remove a directory */
 336 static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 337 {
 338         struct inode *inode = dentry->d_inode;
 339         struct fat_slot_info sinfo;
 340         int err;
 341
 342         lock_kernel();
 343         /*
 344          * Check whether the directory is not in use, then check
 345          * whether it is empty.
 346          */
 347         err = fat_dir_empty(inode);
 348         if (err)
 349                 goto out;
 350         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 351         if (err)
 352                 goto out;
 353
 354         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 355         if (err)
 356                 goto out;
 357         dir->i_nlink--;
 358
 359         inode->i_nlink = 0;
 360         inode->i_ctime = CURRENT_TIME_SEC;
 361         fat_detach(inode);
 362 out:
 363         unlock_kernel();
 364
 365         return err;
 366 }
 367
 368 /***** Make a directory */
 369 static int msdos_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 370 {
 371         struct super_block *sb = dir->i_sb;
 372         struct fat_slot_info sinfo;
 373         struct inode *inode;
 374         unsigned char msdos_name[MSDOS_NAME];
 375         struct timespec ts;
 376         int err, is_hid, cluster;
 377
 378         lock_kernel();
 379
 380         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 381                                 msdos_name, &MSDOS_SB(sb)->options);
 382         if (err)
 383                 goto out;
 384         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 385         /* foo vs .foo situation */
 386         if (!fat_scan(dir, msdos_name, &sinfo)) {
 387                 brelse(sinfo.bh);
 388                 err = -EINVAL;
 389                 goto out;
 390         }
 391
 392         ts = CURRENT_TIME_SEC;
 393         cluster = fat_alloc_new_dir(dir, &ts);
 394         if (cluster < 0) {
 395                 err = cluster;
 396                 goto out;
 397         }
 398         err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
 399         if (err)
 400                 goto out_free;
 401         dir->i_nlink++;
 402
 403         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 404         brelse(sinfo.bh);
 405         if (IS_ERR(inode)) {
 406                 err = PTR_ERR(inode);
 407                 /* the directory was completed, just return a error */
 408                 goto out;
 409         }
 410         inode->i_nlink = 2;
 411         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 412         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 413
 414         d_instantiate(dentry, inode);
 415
 416         unlock_kernel();
 417         return 0;
 418
 419 out_free:
 420         fat_free_clusters(dir, cluster);
 421 out:
 422         unlock_kernel();
 423         return err;
 424 }
 425
 426 /***** Unlink a file */
 427 static int msdos_unlink(struct inode *dir, struct dentry *dentry)
 428 {
 429         struct inode *inode = dentry->d_inode;
 430         struct fat_slot_info sinfo;
 431         int err;
 432
 433         lock_kernel();
 434         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 435         if (err)
 436                 goto out;
 437
 438         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 439         if (err)
 440                 goto out;
 441         inode->i_nlink = 0;
 442         inode->i_ctime = CURRENT_TIME_SEC;
 443         fat_detach(inode);
 444 out:
 445         unlock_kernel();
 446
 447         return err;
 448 }
 449
 450 static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 451                            struct dentry *old_dentry,
 452                            struct inode *new_dir, unsigned char *new_name,
 453                            struct dentry *new_dentry, int is_hid)
 454 {
 455         struct buffer_head *dotdot_bh;
 456         struct msdos_dir_entry *dotdot_de;
 457         loff_t dotdot_i_pos;
 458         struct inode *old_inode, *new_inode;
 459         struct fat_slot_info old_sinfo, sinfo;
 460         struct timespec ts;
 461         int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
 462
 463         old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
 464         old_inode = old_dentry->d_inode;
 465         new_inode = new_dentry->d_inode;
 466
 467         err = fat_scan(old_dir, old_name, &old_sinfo);
 468         if (err) {
 469                 err = -EIO;
 470                 goto out;
 471         }
 472
 473         is_dir = S_ISDIR(old_inode->i_mode);
 474         update_dotdot = (is_dir && old_dir != new_dir);
 475         if (update_dotdot) {
 476                 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
 477                                          &dotdot_i_pos) < 0) {
 478                         err = -EIO;
 479                         goto out;
 480                 }
 481         }
 482
 483         old_attrs = MSDOS_I(old_inode)->i_attrs;
 484         err = fat_scan(new_dir, new_name, &sinfo);
 485         if (!err) {
 486                 if (!new_inode) {
 487                         /* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
 488                         if (sinfo.de != old_sinfo.de) {
 489                                 err = -EINVAL;
 490                                 goto out;
 491                         }
 492                         if (is_hid)
 493                                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 494                         else
 495                                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 496                         if (IS_DIRSYNC(old_dir)) {
 497                                 err = fat_sync_inode(old_inode);
 498                                 if (err) {
 499                                         MSDOS_I(old_inode)->i_attrs = old_attrs;
 500                                         goto out;
 501                                 }
 502                         } else
 503                                 mark_inode_dirty(old_inode);
 504
 505                         old_dir->i_version++;
 506                         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
 507                         if (IS_DIRSYNC(old_dir))
 508                                 (void)fat_sync_inode(old_dir);
 509                         else
 510                                 mark_inode_dirty(old_dir);
 511                         goto out;
 512                 }
 513         }
 514
 515         ts = CURRENT_TIME_SEC;
 516         if (new_inode) {
 517                 if (err)
 518                         goto out;
 519                 if (MSDOS_I(new_inode)->i_pos != sinfo.i_pos) {
 520                         /* WTF??? Cry and fail. */
 521                         printk(KERN_WARNING "msdos_rename: fs corrupted\n");
 522                         goto out;
 523                 }
 524
 525                 if (is_dir) {
 526                         err = fat_dir_empty(new_inode);
 527                         if (err)
 528                                 goto out;
 529                 }
 530                 fat_detach(new_inode);
 531         } else {
 532                 err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
 533                                       &ts, &sinfo);
 534                 if (err)
 535                         goto out;
 536         }
 537         new_dir->i_version++;
 538
 539         fat_detach(old_inode);
 540         fat_attach(old_inode, sinfo.i_pos);
 541         if (is_hid)
 542                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 543         else
 544                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 545         if (IS_DIRSYNC(new_dir)) {
 546                 err = fat_sync_inode(old_inode);
 547                 if (err)
 548                         goto error_inode;
 549         } else
 550                 mark_inode_dirty(old_inode);
 551
 552         if (update_dotdot) {
 553                 int start = MSDOS_I(new_dir)->i_logstart;
 554                 dotdot_de->start = cpu_to_le16(start);
 555                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 556                 mark_buffer_dirty(dotdot_bh);
 557                 if (IS_DIRSYNC(new_dir)) {
 558                         err = sync_dirty_buffer(dotdot_bh);
 559                         if (err)
 560                                 goto error_dotdot;
 561                 }
 562                 old_dir->i_nlink--;
 563                 if (!new_inode)
 564                         new_dir->i_nlink++;
 565         }
 566
 567         err = fat_remove_entries(old_dir, &old_sinfo);  /* and releases bh */
 568         old_sinfo.bh = NULL;
 569         if (err)
 570                 goto error_dotdot;
 571         old_dir->i_version++;
 572         old_dir->i_ctime = old_dir->i_mtime = ts;
 573         if (IS_DIRSYNC(old_dir))
 574                 (void)fat_sync_inode(old_dir);
 575         else
 576                 mark_inode_dirty(old_dir);
 577
 578         if (new_inode) {
 579                 if (is_dir)
 580                         new_inode->i_nlink -= 2;
 581                 else
 582                         new_inode->i_nlink--;
 583                 new_inode->i_ctime = ts;
 584         }
 585 out:
 586         brelse(sinfo.bh);
 587         brelse(dotdot_bh);
 588         brelse(old_sinfo.bh);
 589         return err;
 590
 591 error_dotdot:
 592         /* data cluster is shared, serious corruption */
 593         corrupt = 1;
 594
 595         if (update_dotdot) {
 596                 int start = MSDOS_I(old_dir)->i_logstart;
 597                 dotdot_de->start = cpu_to_le16(start);
 598                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 599                 mark_buffer_dirty(dotdot_bh);
 600                 corrupt |= sync_dirty_buffer(dotdot_bh);
 601         }
 602 error_inode:
 603         fat_detach(old_inode);
 604         fat_attach(old_inode, old_sinfo.i_pos);
 605         MSDOS_I(old_inode)->i_attrs = old_attrs;
 606         if (new_inode) {
 607                 fat_attach(new_inode, sinfo.i_pos);
 608                 if (corrupt)
 609                         corrupt |= fat_sync_inode(new_inode);
 610         } else {
 611                 /*
 612                  * If new entry was not sharing the data cluster, it
 613                  * shouldn't be serious corruption.
 614                  */
 615                 int err2 = fat_remove_entries(new_dir, &sinfo);
 616                 if (corrupt)
 617                         corrupt |= err2;
 618                 sinfo.bh = NULL;
 619         }
 620         if (corrupt < 0) {
 621                 fat_fs_panic(new_dir->i_sb,
 622                              "%s: Filesystem corrupted (i_pos %lld)",
 623                              __FUNCTION__, sinfo.i_pos);
 624         }
 625         goto out;
 626 }
 627
 628 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
 629 static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
 630                         struct inode *new_dir, struct dentry *new_dentry)
 631 {
 632         unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
 633         int err, is_hid;
 634
 635         lock_kernel();
 636
 637         err = msdos_format_name(old_dentry->d_name.name,
 638                                 old_dentry->d_name.len, old_msdos_name,
 639                                 &MSDOS_SB(old_dir->i_sb)->options);
 640         if (err)
 641                 goto out;
 642         err = msdos_format_name(new_dentry->d_name.name,
 643                                 new_dentry->d_name.len, new_msdos_name,
 644                                 &MSDOS_SB(new_dir->i_sb)->options);
 645         if (err)
 646                 goto out;
 647
 648         is_hid =
 649              (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
 650
 651         err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
 652                               new_dir, new_msdos_name, new_dentry, is_hid);
 653 out:
 654         unlock_kernel();
 655         return err;
 656 }
 657
 658 static struct inode_operations msdos_dir_inode_operations = {
 659         .create         = msdos_create,
 660         .lookup         = msdos_lookup,
 661         .unlink         = msdos_unlink,
 662         .mkdir          = msdos_mkdir,
 663         .rmdir          = msdos_rmdir,
 664         .rename         = msdos_rename,
 665         .setattr        = fat_notify_change,
 666 };
 667
 668 static int msdos_fill_super(struct super_block *sb, void *data, int silent)
 669 {
 670         int res;
 671
 672         res = fat_fill_super(sb, data, silent, &msdos_dir_inode_operations, 0);
 673         if (res)
 674                 return res;
 675
 676         sb->s_flags |= MS_NOATIME;
 677         sb->s_root->d_op = &msdos_dentry_operations;
 678         return 0;
 679 }
 680
 681 static struct super_block *msdos_get_sb(struct file_system_type *fs_type,
 682                                         int flags, const char *dev_name,
 683                                         void *data)
 684 {
 685         return get_sb_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
 686 }
 687
 688 static struct file_system_type msdos_fs_type = {
 689         .owner          = THIS_MODULE,
 690         .name           = "msdos",
 691         .get_sb         = msdos_get_sb,
 692         .kill_sb        = kill_block_super,
 693         .fs_flags       = FS_REQUIRES_DEV,
 694 };
 695
 696 static int __init init_msdos_fs(void)
 697 {
 698         return register_filesystem(&msdos_fs_type);
 699 }
 700
 701 static void __exit exit_msdos_fs(void)
 702 {
 703         unregister_filesystem(&msdos_fs_type);
 704 }
 705
 706 MODULE_LICENSE("GPL");
 707 MODULE_AUTHOR("Werner Almesberger");
 708 MODULE_DESCRIPTION("MS-DOS filesystem support");
 709
 710 module_init(init_msdos_fs)
 711 module_exit(exit_msdos_fs)