fs/fat/namei_msdos.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 "fat.h"
  13
  14 /* Characters that are undesirable in an MS-DOS file name */
  15 static unsigned char bad_chars[] = "*?<>|\"";
  16 static unsigned char bad_if_strict[] = "+=,; ";
  17
  18 /***** Formats an MS-DOS file name. Rejects invalid names. */
  19 static int msdos_format_name(const unsigned char *name, int len,
  20                              unsigned char *res, struct fat_mount_options *opts)
  21         /*
  22          * name is the proposed name, len is its length, res is
  23          * the resulting name, opts->name_check is either (r)elaxed,
  24          * (n)ormal or (s)trict, opts->dotsOK allows dots at the
  25          * beginning of name (for hidden files)
  26          */
  27 {
  28         unsigned char *walk;
  29         unsigned char c;
  30         int space;
  31
  32         if (name[0] == '.') {   /* dotfile because . and .. already done */
  33                 if (opts->dotsOK) {
  34                         /* Get rid of dot - test for it elsewhere */
  35                         name++;
  36                         len--;
  37                 } else
  38                         return -EINVAL;
  39         }
  40         /*
  41          * disallow names that _really_ start with a dot
  42          */
  43         space = 1;
  44         c = 0;
  45         for (walk = res; len && walk - res < 8; walk++) {
  46                 c = *name++;
  47                 len--;
  48                 if (opts->name_check != 'r' && strchr(bad_chars, c))
  49                         return -EINVAL;
  50                 if (opts->name_check == 's' && strchr(bad_if_strict, c))
  51                         return -EINVAL;
  52                 if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
  53                         return -EINVAL;
  54                 if (c < ' ' || c == ':' || c == '\\')
  55                         return -EINVAL;
  56         /*
  57          * 0xE5 is legal as a first character, but we must substitute
  58          * 0x05 because 0xE5 marks deleted files.  Yes, DOS really
  59          * does this.
  60          * It seems that Microsoft hacked DOS to support non-US
  61          * characters after the 0xE5 character was already in use to
  62          * mark deleted files.
  63          */
  64                 if ((res == walk) && (c == 0xE5))
  65                         c = 0x05;
  66                 if (c == '.')
  67                         break;
  68                 space = (c == ' ');
  69                 *walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
  70         }
  71         if (space)
  72                 return -EINVAL;
  73         if (opts->name_check == 's' && len && c != '.') {
  74                 c = *name++;
  75                 len--;
  76                 if (c != '.')
  77                         return -EINVAL;
  78         }
  79         while (c != '.' && len--)
  80                 c = *name++;
  81         if (c == '.') {
  82                 while (walk - res < 8)
  83                         *walk++ = ' ';
  84                 while (len > 0 && walk - res < MSDOS_NAME) {
  85                         c = *name++;
  86                         len--;
  87                         if (opts->name_check != 'r' && strchr(bad_chars, c))
  88                                 return -EINVAL;
  89                         if (opts->name_check == 's' &&
  90                             strchr(bad_if_strict, c))
  91                                 return -EINVAL;
  92                         if (c < ' ' || c == ':' || c == '\\')
  93                                 return -EINVAL;
  94                         if (c == '.') {
  95                                 if (opts->name_check == 's')
  96                                         return -EINVAL;
  97                                 break;
  98                         }
  99                         if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
 100                                 return -EINVAL;
 101                         space = c == ' ';
 102                         if (!opts->nocase && c >= 'a' && c <= 'z')
 103                                 *walk++ = c - 32;
 104                         else
 105                                 *walk++ = c;
 106                 }
 107                 if (space)
 108                         return -EINVAL;
 109                 if (opts->name_check == 's' && len)
 110                         return -EINVAL;
 111         }
 112         while (walk - res < MSDOS_NAME)
 113                 *walk++ = ' ';
 114
 115         return 0;
 116 }
 117
 118 /***** Locates a directory entry.  Uses unformatted name. */
 119 static int msdos_find(struct inode *dir, const unsigned char *name, int len,
 120                       struct fat_slot_info *sinfo)
 121 {
 122         struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 123         unsigned char msdos_name[MSDOS_NAME];
 124         int err;
 125
 126         err = msdos_format_name(name, len, msdos_name, &sbi->options);
 127         if (err)
 128                 return -ENOENT;
 129
 130         err = fat_scan(dir, msdos_name, sinfo);
 131         if (!err && sbi->options.dotsOK) {
 132                 if (name[0] == '.') {
 133                         if (!(sinfo->de->attr & ATTR_HIDDEN))
 134                                 err = -ENOENT;
 135                 } else {
 136                         if (sinfo->de->attr & ATTR_HIDDEN)
 137                                 err = -ENOENT;
 138                 }
 139                 if (err)
 140                         brelse(sinfo->bh);
 141         }
 142         return err;
 143 }
 144
 145 /*
 146  * Compute the hash for the msdos name corresponding to the dentry.
 147  * Note: if the name is invalid, we leave the hash code unchanged so
 148  * that the existing dentry can be used. The msdos fs routines will
 149  * return ENOENT or EINVAL as appropriate.
 150  */
 151 static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
 152 {
 153         struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
 154         unsigned char msdos_name[MSDOS_NAME];
 155         int error;
 156
 157         error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
 158         if (!error)
 159                 qstr->hash = full_name_hash(msdos_name, MSDOS_NAME);
 160         return 0;
 161 }
 162
 163 /*
 164  * Compare two msdos names. If either of the names are invalid,
 165  * we fall back to doing the standard name comparison.
 166  */
 167 static int msdos_cmp(const struct dentry *parent, const struct inode *pinode,
 168                 const struct dentry *dentry, const struct inode *inode,
 169                 unsigned int len, const char *str, const struct qstr *name)
 170 {
 171         struct fat_mount_options *options = &MSDOS_SB(parent->d_sb)->options;
 172         unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
 173         int error;
 174
 175         error = msdos_format_name(name->name, name->len, a_msdos_name, options);
 176         if (error)
 177                 goto old_compare;
 178         error = msdos_format_name(str, len, b_msdos_name, options);
 179         if (error)
 180                 goto old_compare;
 181         error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
 182 out:
 183         return error;
 184
 185 old_compare:
 186         error = 1;
 187         if (name->len == len)
 188                 error = memcmp(name->name, str, len);
 189         goto out;
 190 }
 191
 192 static const struct dentry_operations msdos_dentry_operations = {
 193         .d_hash         = msdos_hash,
 194         .d_compare      = msdos_cmp,
 195 };
 196
 197 /*
 198  * AV. Wrappers for FAT sb operations. Is it wise?
 199  */
 200
 201 /***** Get inode using directory and name */
 202 static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry,
 203                                    struct nameidata *nd)
 204 {
 205         struct super_block *sb = dir->i_sb;
 206         struct fat_slot_info sinfo;
 207         struct inode *inode;
 208         int err;
 209
 210         lock_super(sb);
 211
 212         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 213         if (err) {
 214                 if (err == -ENOENT) {
 215                         inode = NULL;
 216                         goto out;
 217                 }
 218                 goto error;
 219         }
 220
 221         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 222         brelse(sinfo.bh);
 223         if (IS_ERR(inode)) {
 224                 err = PTR_ERR(inode);
 225                 goto error;
 226         }
 227 out:
 228         unlock_super(sb);
 229         dentry->d_op = &msdos_dentry_operations;
 230         dentry = d_splice_alias(inode, dentry);
 231         if (dentry)
 232                 dentry->d_op = &msdos_dentry_operations;
 233         return dentry;
 234
 235 error:
 236         unlock_super(sb);
 237         return ERR_PTR(err);
 238 }
 239
 240 /***** Creates a directory entry (name is already formatted). */
 241 static int msdos_add_entry(struct inode *dir, const unsigned char *name,
 242                            int is_dir, int is_hid, int cluster,
 243                            struct timespec *ts, struct fat_slot_info *sinfo)
 244 {
 245         struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 246         struct msdos_dir_entry de;
 247         __le16 time, date;
 248         int err;
 249
 250         memcpy(de.name, name, MSDOS_NAME);
 251         de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
 252         if (is_hid)
 253                 de.attr |= ATTR_HIDDEN;
 254         de.lcase = 0;
 255         fat_time_unix2fat(sbi, ts, &time, &date, NULL);
 256         de.cdate = de.adate = 0;
 257         de.ctime = 0;
 258         de.ctime_cs = 0;
 259         de.time = time;
 260         de.date = date;
 261         de.start = cpu_to_le16(cluster);
 262         de.starthi = cpu_to_le16(cluster >> 16);
 263         de.size = 0;
 264
 265         err = fat_add_entries(dir, &de, 1, sinfo);
 266         if (err)
 267                 return err;
 268
 269         dir->i_ctime = dir->i_mtime = *ts;
 270         if (IS_DIRSYNC(dir))
 271                 (void)fat_sync_inode(dir);
 272         else
 273                 mark_inode_dirty(dir);
 274
 275         return 0;
 276 }
 277
 278 /***** Create a file */
 279 static int msdos_create(struct inode *dir, struct dentry *dentry, int mode,
 280                         struct nameidata *nd)
 281 {
 282         struct super_block *sb = dir->i_sb;
 283         struct inode *inode = NULL;
 284         struct fat_slot_info sinfo;
 285         struct timespec ts;
 286         unsigned char msdos_name[MSDOS_NAME];
 287         int err, is_hid;
 288
 289         lock_super(sb);
 290
 291         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 292                                 msdos_name, &MSDOS_SB(sb)->options);
 293         if (err)
 294                 goto out;
 295         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 296         /* Have to do it due to foo vs. .foo conflicts */
 297         if (!fat_scan(dir, msdos_name, &sinfo)) {
 298                 brelse(sinfo.bh);
 299                 err = -EINVAL;
 300                 goto out;
 301         }
 302
 303         ts = CURRENT_TIME_SEC;
 304         err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
 305         if (err)
 306                 goto out;
 307         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 308         brelse(sinfo.bh);
 309         if (IS_ERR(inode)) {
 310                 err = PTR_ERR(inode);
 311                 goto out;
 312         }
 313         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 314         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 315
 316         d_instantiate(dentry, inode);
 317 out:
 318         unlock_super(sb);
 319         if (!err)
 320                 err = fat_flush_inodes(sb, dir, inode);
 321         return err;
 322 }
 323
 324 /***** Remove a directory */
 325 static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 326 {
 327         struct super_block *sb = dir->i_sb;
 328         struct inode *inode = dentry->d_inode;
 329         struct fat_slot_info sinfo;
 330         int err;
 331
 332         lock_super(sb);
 333         /*
 334          * Check whether the directory is not in use, then check
 335          * whether it is empty.
 336          */
 337         err = fat_dir_empty(inode);
 338         if (err)
 339                 goto out;
 340         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 341         if (err)
 342                 goto out;
 343
 344         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 345         if (err)
 346                 goto out;
 347         drop_nlink(dir);
 348
 349         clear_nlink(inode);
 350         inode->i_ctime = CURRENT_TIME_SEC;
 351         fat_detach(inode);
 352 out:
 353         unlock_super(sb);
 354         if (!err)
 355                 err = fat_flush_inodes(sb, dir, inode);
 356
 357         return err;
 358 }
 359
 360 /***** Make a directory */
 361 static int msdos_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 362 {
 363         struct super_block *sb = dir->i_sb;
 364         struct fat_slot_info sinfo;
 365         struct inode *inode;
 366         unsigned char msdos_name[MSDOS_NAME];
 367         struct timespec ts;
 368         int err, is_hid, cluster;
 369
 370         lock_super(sb);
 371
 372         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 373                                 msdos_name, &MSDOS_SB(sb)->options);
 374         if (err)
 375                 goto out;
 376         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 377         /* foo vs .foo situation */
 378         if (!fat_scan(dir, msdos_name, &sinfo)) {
 379                 brelse(sinfo.bh);
 380                 err = -EINVAL;
 381                 goto out;
 382         }
 383
 384         ts = CURRENT_TIME_SEC;
 385         cluster = fat_alloc_new_dir(dir, &ts);
 386         if (cluster < 0) {
 387                 err = cluster;
 388                 goto out;
 389         }
 390         err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
 391         if (err)
 392                 goto out_free;
 393         inc_nlink(dir);
 394
 395         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 396         brelse(sinfo.bh);
 397         if (IS_ERR(inode)) {
 398                 err = PTR_ERR(inode);
 399                 /* the directory was completed, just return a error */
 400                 goto out;
 401         }
 402         inode->i_nlink = 2;
 403         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 404         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 405
 406         d_instantiate(dentry, inode);
 407
 408         unlock_super(sb);
 409         fat_flush_inodes(sb, dir, inode);
 410         return 0;
 411
 412 out_free:
 413         fat_free_clusters(dir, cluster);
 414 out:
 415         unlock_super(sb);
 416         return err;
 417 }
 418
 419 /***** Unlink a file */
 420 static int msdos_unlink(struct inode *dir, struct dentry *dentry)
 421 {
 422         struct inode *inode = dentry->d_inode;
 423         struct super_block *sb= inode->i_sb;
 424         struct fat_slot_info sinfo;
 425         int err;
 426
 427         lock_super(sb);
 428         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 429         if (err)
 430                 goto out;
 431
 432         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 433         if (err)
 434                 goto out;
 435         clear_nlink(inode);
 436         inode->i_ctime = CURRENT_TIME_SEC;
 437         fat_detach(inode);
 438 out:
 439         unlock_super(sb);
 440         if (!err)
 441                 err = fat_flush_inodes(sb, dir, inode);
 442
 443         return err;
 444 }
 445
 446 static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 447                            struct dentry *old_dentry,
 448                            struct inode *new_dir, unsigned char *new_name,
 449                            struct dentry *new_dentry, int is_hid)
 450 {
 451         struct buffer_head *dotdot_bh;
 452         struct msdos_dir_entry *dotdot_de;
 453         struct inode *old_inode, *new_inode;
 454         struct fat_slot_info old_sinfo, sinfo;
 455         struct timespec ts;
 456         loff_t dotdot_i_pos, new_i_pos;
 457         int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
 458
 459         old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
 460         old_inode = old_dentry->d_inode;
 461         new_inode = new_dentry->d_inode;
 462
 463         err = fat_scan(old_dir, old_name, &old_sinfo);
 464         if (err) {
 465                 err = -EIO;
 466                 goto out;
 467         }
 468
 469         is_dir = S_ISDIR(old_inode->i_mode);
 470         update_dotdot = (is_dir && old_dir != new_dir);
 471         if (update_dotdot) {
 472                 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
 473                                          &dotdot_i_pos) < 0) {
 474                         err = -EIO;
 475                         goto out;
 476                 }
 477         }
 478
 479         old_attrs = MSDOS_I(old_inode)->i_attrs;
 480         err = fat_scan(new_dir, new_name, &sinfo);
 481         if (!err) {
 482                 if (!new_inode) {
 483                         /* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
 484                         if (sinfo.de != old_sinfo.de) {
 485                                 err = -EINVAL;
 486                                 goto out;
 487                         }
 488                         if (is_hid)
 489                                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 490                         else
 491                                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 492                         if (IS_DIRSYNC(old_dir)) {
 493                                 err = fat_sync_inode(old_inode);
 494                                 if (err) {
 495                                         MSDOS_I(old_inode)->i_attrs = old_attrs;
 496                                         goto out;
 497                                 }
 498                         } else
 499                                 mark_inode_dirty(old_inode);
 500
 501                         old_dir->i_version++;
 502                         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
 503                         if (IS_DIRSYNC(old_dir))
 504                                 (void)fat_sync_inode(old_dir);
 505                         else
 506                                 mark_inode_dirty(old_dir);
 507                         goto out;
 508                 }
 509         }
 510
 511         ts = CURRENT_TIME_SEC;
 512         if (new_inode) {
 513                 if (err)
 514                         goto out;
 515                 if (is_dir) {
 516                         err = fat_dir_empty(new_inode);
 517                         if (err)
 518                                 goto out;
 519                 }
 520                 new_i_pos = MSDOS_I(new_inode)->i_pos;
 521                 fat_detach(new_inode);
 522         } else {
 523                 err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
 524                                       &ts, &sinfo);
 525                 if (err)
 526                         goto out;
 527                 new_i_pos = sinfo.i_pos;
 528         }
 529         new_dir->i_version++;
 530
 531         fat_detach(old_inode);
 532         fat_attach(old_inode, new_i_pos);
 533         if (is_hid)
 534                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 535         else
 536                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 537         if (IS_DIRSYNC(new_dir)) {
 538                 err = fat_sync_inode(old_inode);
 539                 if (err)
 540                         goto error_inode;
 541         } else
 542                 mark_inode_dirty(old_inode);
 543
 544         if (update_dotdot) {
 545                 int start = MSDOS_I(new_dir)->i_logstart;
 546                 dotdot_de->start = cpu_to_le16(start);
 547                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 548                 mark_buffer_dirty_inode(dotdot_bh, old_inode);
 549                 if (IS_DIRSYNC(new_dir)) {
 550                         err = sync_dirty_buffer(dotdot_bh);
 551                         if (err)
 552                                 goto error_dotdot;
 553                 }
 554                 drop_nlink(old_dir);
 555                 if (!new_inode)
 556                         inc_nlink(new_dir);
 557         }
 558
 559         err = fat_remove_entries(old_dir, &old_sinfo);  /* and releases bh */
 560         old_sinfo.bh = NULL;
 561         if (err)
 562                 goto error_dotdot;
 563         old_dir->i_version++;
 564         old_dir->i_ctime = old_dir->i_mtime = ts;
 565         if (IS_DIRSYNC(old_dir))
 566                 (void)fat_sync_inode(old_dir);
 567         else
 568                 mark_inode_dirty(old_dir);
 569
 570         if (new_inode) {
 571                 drop_nlink(new_inode);
 572                 if (is_dir)
 573                         drop_nlink(new_inode);
 574                 new_inode->i_ctime = ts;
 575         }
 576 out:
 577         brelse(sinfo.bh);
 578         brelse(dotdot_bh);
 579         brelse(old_sinfo.bh);
 580         return err;
 581
 582 error_dotdot:
 583         /* data cluster is shared, serious corruption */
 584         corrupt = 1;
 585
 586         if (update_dotdot) {
 587                 int start = MSDOS_I(old_dir)->i_logstart;
 588                 dotdot_de->start = cpu_to_le16(start);
 589                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 590                 mark_buffer_dirty_inode(dotdot_bh, old_inode);
 591                 corrupt |= sync_dirty_buffer(dotdot_bh);
 592         }
 593 error_inode:
 594         fat_detach(old_inode);
 595         fat_attach(old_inode, old_sinfo.i_pos);
 596         MSDOS_I(old_inode)->i_attrs = old_attrs;
 597         if (new_inode) {
 598                 fat_attach(new_inode, new_i_pos);
 599                 if (corrupt)
 600                         corrupt |= fat_sync_inode(new_inode);
 601         } else {
 602                 /*
 603                  * If new entry was not sharing the data cluster, it
 604                  * shouldn't be serious corruption.
 605                  */
 606                 int err2 = fat_remove_entries(new_dir, &sinfo);
 607                 if (corrupt)
 608                         corrupt |= err2;
 609                 sinfo.bh = NULL;
 610         }
 611         if (corrupt < 0) {
 612                 fat_fs_error(new_dir->i_sb,
 613                              "%s: Filesystem corrupted (i_pos %lld)",
 614                              __func__, sinfo.i_pos);
 615         }
 616         goto out;
 617 }
 618
 619 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
 620 static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
 621                         struct inode *new_dir, struct dentry *new_dentry)
 622 {
 623         struct super_block *sb = old_dir->i_sb;
 624         unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
 625         int err, is_hid;
 626
 627         lock_super(sb);
 628
 629         err = msdos_format_name(old_dentry->d_name.name,
 630                                 old_dentry->d_name.len, old_msdos_name,
 631                                 &MSDOS_SB(old_dir->i_sb)->options);
 632         if (err)
 633                 goto out;
 634         err = msdos_format_name(new_dentry->d_name.name,
 635                                 new_dentry->d_name.len, new_msdos_name,
 636                                 &MSDOS_SB(new_dir->i_sb)->options);
 637         if (err)
 638                 goto out;
 639
 640         is_hid =
 641              (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
 642
 643         err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
 644                               new_dir, new_msdos_name, new_dentry, is_hid);
 645 out:
 646         unlock_super(sb);
 647         if (!err)
 648                 err = fat_flush_inodes(sb, old_dir, new_dir);
 649         return err;
 650 }
 651
 652 static const struct inode_operations msdos_dir_inode_operations = {
 653         .create         = msdos_create,
 654         .lookup         = msdos_lookup,
 655         .unlink         = msdos_unlink,
 656         .mkdir          = msdos_mkdir,
 657         .rmdir          = msdos_rmdir,
 658         .rename         = msdos_rename,
 659         .setattr        = fat_setattr,
 660         .getattr        = fat_getattr,
 661 };
 662
 663 static int msdos_fill_super(struct super_block *sb, void *data, int silent)
 664 {
 665         int res;
 666
 667         lock_super(sb);
 668         res = fat_fill_super(sb, data, silent, &msdos_dir_inode_operations, 0);
 669         if (res) {
 670                 unlock_super(sb);
 671                 return res;
 672         }
 673
 674         sb->s_flags |= MS_NOATIME;
 675         sb->s_root->d_op = &msdos_dentry_operations;
 676         unlock_super(sb);
 677         return 0;
 678 }
 679
 680 static struct dentry *msdos_mount(struct file_system_type *fs_type,
 681                         int flags, const char *dev_name,
 682                         void *data)
 683 {
 684         return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
 685 }
 686
 687 static struct file_system_type msdos_fs_type = {
 688         .owner          = THIS_MODULE,
 689         .name           = "msdos",
 690         .mount          = msdos_mount,
 691         .kill_sb        = kill_block_super,
 692         .fs_flags       = FS_REQUIRES_DEV,
 693 };
 694
 695 static int __init init_msdos_fs(void)
 696 {
 697         return register_filesystem(&msdos_fs_type);
 698 }
 699
 700 static void __exit exit_msdos_fs(void)
 701 {
 702         unregister_filesystem(&msdos_fs_type);
 703 }
 704
 705 MODULE_LICENSE("GPL");
 706 MODULE_AUTHOR("Werner Almesberger");
 707 MODULE_DESCRIPTION("MS-DOS filesystem support");
 708
 709 module_init(init_msdos_fs)
 710 module_exit(exit_msdos_fs)