drivers/usb/core/inode.c

   1 /*****************************************************************************/
   2
   3 /*
   4  *      inode.c  --  Inode/Dentry functions for the USB device file system.
   5  *
   6  *      Copyright (C) 2000 Thomas Sailer (sailer@ife.ee.ethz.ch)
   7  *      Copyright (C) 2001,2002,2004 Greg Kroah-Hartman (greg@kroah.com)
   8  *
   9  *      This program is free software; you can redistribute it and/or modify
  10  *      it under the terms of the GNU General Public License as published by
  11  *      the Free Software Foundation; either version 2 of the License, or
  12  *      (at your option) any later version.
  13  *
  14  *      This program is distributed in the hope that it will be useful,
  15  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *      GNU General Public License for more details.
  18  *
  19  *      You should have received a copy of the GNU General Public License
  20  *      along with this program; if not, write to the Free Software
  21  *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  *
  23  *  History:
  24  *   0.1  04.01.2000  Created
  25  *   0.2  10.12.2001  converted to use the vfs layer better
  26  */
  27
  28 /*****************************************************************************/
  29
  30 #include <linux/module.h>
  31 #include <linux/fs.h>
  32 #include <linux/mount.h>
  33 #include <linux/pagemap.h>
  34 #include <linux/init.h>
  35 #include <linux/proc_fs.h>
  36 #include <linux/usb.h>
  37 #include <linux/namei.h>
  38 #include <linux/usbdevice_fs.h>
  39 #include <linux/parser.h>
  40 #include <linux/notifier.h>
  41 #include <linux/seq_file.h>
  42 #include <asm/byteorder.h>
  43 #include "usb.h"
  44 #include "hcd.h"
  45
  46 #define USBFS_DEFAULT_DEVMODE (S_IWUSR | S_IRUGO)
  47 #define USBFS_DEFAULT_BUSMODE (S_IXUGO | S_IRUGO)
  48 #define USBFS_DEFAULT_LISTMODE S_IRUGO
  49
  50 static struct super_operations usbfs_ops;
  51 static const struct file_operations default_file_operations;
  52 static struct vfsmount *usbfs_mount;
  53 static int usbfs_mount_count;   /* = 0 */
  54 static int ignore_mount = 0;
  55
  56 static struct dentry *devices_usbfs_dentry;
  57 static int num_buses;   /* = 0 */
  58
  59 static uid_t devuid;    /* = 0 */
  60 static uid_t busuid;    /* = 0 */
  61 static uid_t listuid;   /* = 0 */
  62 static gid_t devgid;    /* = 0 */
  63 static gid_t busgid;    /* = 0 */
  64 static gid_t listgid;   /* = 0 */
  65 static umode_t devmode = USBFS_DEFAULT_DEVMODE;
  66 static umode_t busmode = USBFS_DEFAULT_BUSMODE;
  67 static umode_t listmode = USBFS_DEFAULT_LISTMODE;
  68
  69 static int usbfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
  70 {
  71         if (devuid != 0)
  72                 seq_printf(seq, ",devuid=%u", devuid);
  73         if (devgid != 0)
  74                 seq_printf(seq, ",devgid=%u", devgid);
  75         if (devmode != USBFS_DEFAULT_DEVMODE)
  76                 seq_printf(seq, ",devmode=%o", devmode);
  77         if (busuid != 0)
  78                 seq_printf(seq, ",busuid=%u", busuid);
  79         if (busgid != 0)
  80                 seq_printf(seq, ",busgid=%u", busgid);
  81         if (busmode != USBFS_DEFAULT_BUSMODE)
  82                 seq_printf(seq, ",busmode=%o", busmode);
  83         if (listuid != 0)
  84                 seq_printf(seq, ",listuid=%u", listuid);
  85         if (listgid != 0)
  86                 seq_printf(seq, ",listgid=%u", listgid);
  87         if (listmode != USBFS_DEFAULT_LISTMODE)
  88                 seq_printf(seq, ",listmode=%o", listmode);
  89
  90         return 0;
  91 }
  92
  93 enum {
  94         Opt_devuid, Opt_devgid, Opt_devmode,
  95         Opt_busuid, Opt_busgid, Opt_busmode,
  96         Opt_listuid, Opt_listgid, Opt_listmode,
  97         Opt_err,
  98 };
  99
 100 static match_table_t tokens = {
 101         {Opt_devuid, "devuid=%u"},
 102         {Opt_devgid, "devgid=%u"},
 103         {Opt_devmode, "devmode=%o"},
 104         {Opt_busuid, "busuid=%u"},
 105         {Opt_busgid, "busgid=%u"},
 106         {Opt_busmode, "busmode=%o"},
 107         {Opt_listuid, "listuid=%u"},
 108         {Opt_listgid, "listgid=%u"},
 109         {Opt_listmode, "listmode=%o"},
 110         {Opt_err, NULL}
 111 };
 112
 113 static int parse_options(struct super_block *s, char *data)
 114 {
 115         char *p;
 116         int option;
 117
 118         /* (re)set to defaults. */
 119         devuid = 0;
 120         busuid = 0;
 121         listuid = 0;
 122         devgid = 0;
 123         busgid = 0;
 124         listgid = 0;
 125         devmode = USBFS_DEFAULT_DEVMODE;
 126         busmode = USBFS_DEFAULT_BUSMODE;
 127         listmode = USBFS_DEFAULT_LISTMODE;
 128
 129         while ((p = strsep(&data, ",")) != NULL) {
 130                 substring_t args[MAX_OPT_ARGS];
 131                 int token;
 132                 if (!*p)
 133                         continue;
 134
 135                 token = match_token(p, tokens, args);
 136                 switch (token) {
 137                 case Opt_devuid:
 138                         if (match_int(&args[0], &option))
 139                                return -EINVAL;
 140                         devuid = option;
 141                         break;
 142                 case Opt_devgid:
 143                         if (match_int(&args[0], &option))
 144                                return -EINVAL;
 145                         devgid = option;
 146                         break;
 147                 case Opt_devmode:
 148                         if (match_octal(&args[0], &option))
 149                                 return -EINVAL;
 150                         devmode = option & S_IRWXUGO;
 151                         break;
 152                 case Opt_busuid:
 153                         if (match_int(&args[0], &option))
 154                                return -EINVAL;
 155                         busuid = option;
 156                         break;
 157                 case Opt_busgid:
 158                         if (match_int(&args[0], &option))
 159                                return -EINVAL;
 160                         busgid = option;
 161                         break;
 162                 case Opt_busmode:
 163                         if (match_octal(&args[0], &option))
 164                                 return -EINVAL;
 165                         busmode = option & S_IRWXUGO;
 166                         break;
 167                 case Opt_listuid:
 168                         if (match_int(&args[0], &option))
 169                                return -EINVAL;
 170                         listuid = option;
 171                         break;
 172                 case Opt_listgid:
 173                         if (match_int(&args[0], &option))
 174                                return -EINVAL;
 175                         listgid = option;
 176                         break;
 177                 case Opt_listmode:
 178                         if (match_octal(&args[0], &option))
 179                                 return -EINVAL;
 180                         listmode = option & S_IRWXUGO;
 181                         break;
 182                 default:
 183                         err("usbfs: unrecognised mount option \"%s\" "
 184                             "or missing value\n", p);
 185                         return -EINVAL;
 186                 }
 187         }
 188
 189         return 0;
 190 }
 191
 192 static void update_special(struct dentry *special)
 193 {
 194         special->d_inode->i_uid = listuid;
 195         special->d_inode->i_gid = listgid;
 196         special->d_inode->i_mode = S_IFREG | listmode;
 197 }
 198
 199 static void update_dev(struct dentry *dev)
 200 {
 201         dev->d_inode->i_uid = devuid;
 202         dev->d_inode->i_gid = devgid;
 203         dev->d_inode->i_mode = S_IFREG | devmode;
 204 }
 205
 206 static void update_bus(struct dentry *bus)
 207 {
 208         struct dentry *dev = NULL;
 209
 210         bus->d_inode->i_uid = busuid;
 211         bus->d_inode->i_gid = busgid;
 212         bus->d_inode->i_mode = S_IFDIR | busmode;
 213
 214         mutex_lock(&bus->d_inode->i_mutex);
 215
 216         list_for_each_entry(dev, &bus->d_subdirs, d_u.d_child)
 217                 if (dev->d_inode)
 218                         update_dev(dev);
 219
 220         mutex_unlock(&bus->d_inode->i_mutex);
 221 }
 222
 223 static void update_sb(struct super_block *sb)
 224 {
 225         struct dentry *root = sb->s_root;
 226         struct dentry *bus = NULL;
 227
 228         if (!root)
 229                 return;
 230
 231         mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT);
 232
 233         list_for_each_entry(bus, &root->d_subdirs, d_u.d_child) {
 234                 if (bus->d_inode) {
 235                         switch (S_IFMT & bus->d_inode->i_mode) {
 236                         case S_IFDIR:
 237                                 update_bus(bus);
 238                                 break;
 239                         case S_IFREG:
 240                                 update_special(bus);
 241                                 break;
 242                         default:
 243                                 warn("Unknown node %s mode %x found on remount!\n",bus->d_name.name,bus->d_inode->i_mode);
 244                                 break;
 245                         }
 246                 }
 247         }
 248
 249         mutex_unlock(&root->d_inode->i_mutex);
 250 }
 251
 252 static int remount(struct super_block *sb, int *flags, char *data)
 253 {
 254         /* If this is not a real mount,
 255          * i.e. it's a simple_pin_fs from create_special_files,
 256          * then ignore it.
 257          */
 258         if (ignore_mount)
 259                 return 0;
 260
 261         if (parse_options(sb, data)) {
 262                 warn("usbfs: mount parameter error:");
 263                 return -EINVAL;
 264         }
 265
 266         if (usbfs_mount && usbfs_mount->mnt_sb)
 267                 update_sb(usbfs_mount->mnt_sb);
 268
 269         return 0;
 270 }
 271
 272 static struct inode *usbfs_get_inode (struct super_block *sb, int mode, dev_t dev)
 273 {
 274         struct inode *inode = new_inode(sb);
 275
 276         if (inode) {
 277                 inode->i_mode = mode;
 278                 inode->i_uid = current->fsuid;
 279                 inode->i_gid = current->fsgid;
 280                 inode->i_blocks = 0;
 281                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 282                 switch (mode & S_IFMT) {
 283                 default:
 284                         init_special_inode(inode, mode, dev);
 285                         break;
 286                 case S_IFREG:
 287                         inode->i_fop = &default_file_operations;
 288                         break;
 289                 case S_IFDIR:
 290                         inode->i_op = &simple_dir_inode_operations;
 291                         inode->i_fop = &simple_dir_operations;
 292
 293                         /* directory inodes start off with i_nlink == 2 (for "." entry) */
 294                         inc_nlink(inode);
 295                         break;
 296                 }
 297         }
 298         return inode;
 299 }
 300
 301 /* SMP-safe */
 302 static int usbfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
 303                         dev_t dev)
 304 {
 305         struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
 306         int error = -EPERM;
 307
 308         if (dentry->d_inode)
 309                 return -EEXIST;
 310
 311         if (inode) {
 312                 d_instantiate(dentry, inode);
 313                 dget(dentry);
 314                 error = 0;
 315         }
 316         return error;
 317 }
 318
 319 static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
 320 {
 321         int res;
 322
 323         mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
 324         res = usbfs_mknod (dir, dentry, mode, 0);
 325         if (!res)
 326                 inc_nlink(dir);
 327         return res;
 328 }
 329
 330 static int usbfs_create (struct inode *dir, struct dentry *dentry, int mode)
 331 {
 332         mode = (mode & S_IALLUGO) | S_IFREG;
 333         return usbfs_mknod (dir, dentry, mode, 0);
 334 }
 335
 336 static inline int usbfs_positive (struct dentry *dentry)
 337 {
 338         return dentry->d_inode && !d_unhashed(dentry);
 339 }
 340
 341 static int usbfs_empty (struct dentry *dentry)
 342 {
 343         struct list_head *list;
 344
 345         spin_lock(&dcache_lock);
 346
 347         list_for_each(list, &dentry->d_subdirs) {
 348                 struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
 349                 if (usbfs_positive(de)) {
 350                         spin_unlock(&dcache_lock);
 351                         return 0;
 352                 }
 353         }
 354
 355         spin_unlock(&dcache_lock);
 356         return 1;
 357 }
 358
 359 static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
 360 {
 361         struct inode *inode = dentry->d_inode;
 362         mutex_lock(&inode->i_mutex);
 363         drop_nlink(dentry->d_inode);
 364         dput(dentry);
 365         mutex_unlock(&inode->i_mutex);
 366         d_delete(dentry);
 367         return 0;
 368 }
 369
 370 static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
 371 {
 372         int error = -ENOTEMPTY;
 373         struct inode * inode = dentry->d_inode;
 374
 375         mutex_lock(&inode->i_mutex);
 376         dentry_unhash(dentry);
 377         if (usbfs_empty(dentry)) {
 378                 drop_nlink(dentry->d_inode);
 379                 drop_nlink(dentry->d_inode);
 380                 dput(dentry);
 381                 inode->i_flags |= S_DEAD;
 382                 drop_nlink(dir);
 383                 error = 0;
 384         }
 385         mutex_unlock(&inode->i_mutex);
 386         if (!error)
 387                 d_delete(dentry);
 388         dput(dentry);
 389         return error;
 390 }
 391
 392
 393 /* default file operations */
 394 static ssize_t default_read_file (struct file *file, char __user *buf,
 395                                   size_t count, loff_t *ppos)
 396 {
 397         return 0;
 398 }
 399
 400 static ssize_t default_write_file (struct file *file, const char __user *buf,
 401                                    size_t count, loff_t *ppos)
 402 {
 403         return count;
 404 }
 405
 406 static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
 407 {
 408         loff_t retval = -EINVAL;
 409
 410         mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
 411         switch(orig) {
 412         case 0:
 413                 if (offset > 0) {
 414                         file->f_pos = offset;
 415                         retval = file->f_pos;
 416                 }
 417                 break;
 418         case 1:
 419                 if ((offset + file->f_pos) > 0) {
 420                         file->f_pos += offset;
 421                         retval = file->f_pos;
 422                 }
 423                 break;
 424         default:
 425                 break;
 426         }
 427         mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
 428         return retval;
 429 }
 430
 431 static int default_open (struct inode *inode, struct file *file)
 432 {
 433         if (inode->i_private)
 434                 file->private_data = inode->i_private;
 435
 436         return 0;
 437 }
 438
 439 static const struct file_operations default_file_operations = {
 440         .read =         default_read_file,
 441         .write =        default_write_file,
 442         .open =         default_open,
 443         .llseek =       default_file_lseek,
 444 };
 445
 446 static struct super_operations usbfs_ops = {
 447         .statfs =       simple_statfs,
 448         .drop_inode =   generic_delete_inode,
 449         .remount_fs =   remount,
 450         .show_options = usbfs_show_options,
 451 };
 452
 453 static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
 454 {
 455         struct inode *inode;
 456         struct dentry *root;
 457
 458         sb->s_blocksize = PAGE_CACHE_SIZE;
 459         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 460         sb->s_magic = USBDEVICE_SUPER_MAGIC;
 461         sb->s_op = &usbfs_ops;
 462         sb->s_time_gran = 1;
 463         inode = usbfs_get_inode(sb, S_IFDIR | 0755, 0);
 464
 465         if (!inode) {
 466                 dbg("%s: could not get inode!",__func__);
 467                 return -ENOMEM;
 468         }
 469
 470         root = d_alloc_root(inode);
 471         if (!root) {
 472                 dbg("%s: could not get root dentry!",__func__);
 473                 iput(inode);
 474                 return -ENOMEM;
 475         }
 476         sb->s_root = root;
 477         return 0;
 478 }
 479
 480 /*
 481  * fs_create_by_name - create a file, given a name
 482  * @name:       name of file
 483  * @mode:       type of file
 484  * @parent:     dentry of directory to create it in
 485  * @dentry:     resulting dentry of file
 486  *
 487  * This function handles both regular files and directories.
 488  */
 489 static int fs_create_by_name (const char *name, mode_t mode,
 490                               struct dentry *parent, struct dentry **dentry)
 491 {
 492         int error = 0;
 493
 494         /* If the parent is not specified, we create it in the root.
 495          * We need the root dentry to do this, which is in the super
 496          * block. A pointer to that is in the struct vfsmount that we
 497          * have around.
 498          */
 499         if (!parent ) {
 500                 if (usbfs_mount && usbfs_mount->mnt_sb) {
 501                         parent = usbfs_mount->mnt_sb->s_root;
 502                 }
 503         }
 504
 505         if (!parent) {
 506                 dbg("Ah! can not find a parent!");
 507                 return -EFAULT;
 508         }
 509
 510         *dentry = NULL;
 511         mutex_lock(&parent->d_inode->i_mutex);
 512         *dentry = lookup_one_len(name, parent, strlen(name));
 513         if (!IS_ERR(dentry)) {
 514                 if ((mode & S_IFMT) == S_IFDIR)
 515                         error = usbfs_mkdir (parent->d_inode, *dentry, mode);
 516                 else
 517                         error = usbfs_create (parent->d_inode, *dentry, mode);
 518         } else
 519                 error = PTR_ERR(dentry);
 520         mutex_unlock(&parent->d_inode->i_mutex);
 521
 522         return error;
 523 }
 524
 525 static struct dentry *fs_create_file (const char *name, mode_t mode,
 526                                       struct dentry *parent, void *data,
 527                                       const struct file_operations *fops,
 528                                       uid_t uid, gid_t gid)
 529 {
 530         struct dentry *dentry;
 531         int error;
 532
 533         dbg("creating file '%s'",name);
 534
 535         error = fs_create_by_name (name, mode, parent, &dentry);
 536         if (error) {
 537                 dentry = NULL;
 538         } else {
 539                 if (dentry->d_inode) {
 540                         if (data)
 541                                 dentry->d_inode->i_private = data;
 542                         if (fops)
 543                                 dentry->d_inode->i_fop = fops;
 544                         dentry->d_inode->i_uid = uid;
 545                         dentry->d_inode->i_gid = gid;
 546                 }
 547         }
 548
 549         return dentry;
 550 }
 551
 552 static void fs_remove_file (struct dentry *dentry)
 553 {
 554         struct dentry *parent = dentry->d_parent;
 555
 556         if (!parent || !parent->d_inode)
 557                 return;
 558
 559         mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_PARENT);
 560         if (usbfs_positive(dentry)) {
 561                 if (dentry->d_inode) {
 562                         if (S_ISDIR(dentry->d_inode->i_mode))
 563                                 usbfs_rmdir(parent->d_inode, dentry);
 564                         else
 565                                 usbfs_unlink(parent->d_inode, dentry);
 566                 dput(dentry);
 567                 }
 568         }
 569         mutex_unlock(&parent->d_inode->i_mutex);
 570 }
 571
 572 /* --------------------------------------------------------------------- */
 573
 574 static int usb_get_sb(struct file_system_type *fs_type,
 575         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 576 {
 577         return get_sb_single(fs_type, flags, data, usbfs_fill_super, mnt);
 578 }
 579
 580 static struct file_system_type usb_fs_type = {
 581         .owner =        THIS_MODULE,
 582         .name =         "usbfs",
 583         .get_sb =       usb_get_sb,
 584         .kill_sb =      kill_litter_super,
 585 };
 586
 587 /* --------------------------------------------------------------------- */
 588
 589 static int create_special_files (void)
 590 {
 591         struct dentry *parent;
 592         int retval;
 593
 594         /* the simple_pin_fs calls will call remount with no options
 595          * without this flag that would overwrite the real mount options (if any)
 596          */
 597         ignore_mount = 1;
 598
 599         /* create the devices special file */
 600         retval = simple_pin_fs(&usb_fs_type, &usbfs_mount, &usbfs_mount_count);
 601         if (retval) {
 602                 err ("Unable to get usbfs mount");
 603                 goto exit;
 604         }
 605
 606         ignore_mount = 0;
 607
 608         parent = usbfs_mount->mnt_sb->s_root;
 609         devices_usbfs_dentry = fs_create_file ("devices",
 610                                                listmode | S_IFREG, parent,
 611                                                NULL, &usbfs_devices_fops,
 612                                                listuid, listgid);
 613         if (devices_usbfs_dentry == NULL) {
 614                 err ("Unable to create devices usbfs file");
 615                 retval = -ENODEV;
 616                 goto error_clean_mounts;
 617         }
 618
 619         goto exit;
 620
 621 error_clean_mounts:
 622         simple_release_fs(&usbfs_mount, &usbfs_mount_count);
 623 exit:
 624         return retval;
 625 }
 626
 627 static void remove_special_files (void)
 628 {
 629         if (devices_usbfs_dentry)
 630                 fs_remove_file (devices_usbfs_dentry);
 631         devices_usbfs_dentry = NULL;
 632         simple_release_fs(&usbfs_mount, &usbfs_mount_count);
 633 }
 634
 635 void usbfs_update_special (void)
 636 {
 637         struct inode *inode;
 638
 639         if (devices_usbfs_dentry) {
 640                 inode = devices_usbfs_dentry->d_inode;
 641                 if (inode)
 642                         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 643         }
 644 }
 645
 646 static void usbfs_add_bus(struct usb_bus *bus)
 647 {
 648         struct dentry *parent;
 649         char name[8];
 650         int retval;
 651
 652         /* create the special files if this is the first bus added */
 653         if (num_buses == 0) {
 654                 retval = create_special_files();
 655                 if (retval)
 656                         return;
 657         }
 658         ++num_buses;
 659
 660         sprintf (name, "%03d", bus->busnum);
 661
 662         parent = usbfs_mount->mnt_sb->s_root;
 663         bus->usbfs_dentry = fs_create_file (name, busmode | S_IFDIR, parent,
 664                                             bus, NULL, busuid, busgid);
 665         if (bus->usbfs_dentry == NULL) {
 666                 err ("error creating usbfs bus entry");
 667                 return;
 668         }
 669 }
 670
 671 static void usbfs_remove_bus(struct usb_bus *bus)
 672 {
 673         if (bus->usbfs_dentry) {
 674                 fs_remove_file (bus->usbfs_dentry);
 675                 bus->usbfs_dentry = NULL;
 676         }
 677
 678         --num_buses;
 679         if (num_buses <= 0) {
 680                 remove_special_files();
 681                 num_buses = 0;
 682         }
 683 }
 684
 685 static void usbfs_add_device(struct usb_device *dev)
 686 {
 687         char name[8];
 688         int i;
 689         int i_size;
 690
 691         sprintf (name, "%03d", dev->devnum);
 692         dev->usbfs_dentry = fs_create_file (name, devmode | S_IFREG,
 693                                             dev->bus->usbfs_dentry, dev,
 694                                             &usbdev_file_operations,
 695                                             devuid, devgid);
 696         if (dev->usbfs_dentry == NULL) {
 697                 err ("error creating usbfs device entry");
 698                 return;
 699         }
 700
 701         /* Set the size of the device's file to be
 702          * equal to the size of the device descriptors. */
 703         i_size = sizeof (struct usb_device_descriptor);
 704         for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
 705                 struct usb_config_descriptor *config =
 706                         (struct usb_config_descriptor *)dev->rawdescriptors[i];
 707                 i_size += le16_to_cpu(config->wTotalLength);
 708         }
 709         if (dev->usbfs_dentry->d_inode)
 710                 dev->usbfs_dentry->d_inode->i_size = i_size;
 711 }
 712
 713 static void usbfs_remove_device(struct usb_device *dev)
 714 {
 715         if (dev->usbfs_dentry) {
 716                 fs_remove_file (dev->usbfs_dentry);
 717                 dev->usbfs_dentry = NULL;
 718         }
 719         usb_fs_classdev_common_remove(dev);
 720 }
 721
 722 static int usbfs_notify(struct notifier_block *self, unsigned long action, void *dev)
 723 {
 724         switch (action) {
 725         case USB_DEVICE_ADD:
 726                 usbfs_add_device(dev);
 727                 break;
 728         case USB_DEVICE_REMOVE:
 729                 usbfs_remove_device(dev);
 730                 break;
 731         case USB_BUS_ADD:
 732                 usbfs_add_bus(dev);
 733                 break;
 734         case USB_BUS_REMOVE:
 735                 usbfs_remove_bus(dev);
 736         }
 737
 738         usbfs_update_special();
 739         usbfs_conn_disc_event();
 740         return NOTIFY_OK;
 741 }
 742
 743 static struct notifier_block usbfs_nb = {
 744         .notifier_call =        usbfs_notify,
 745 };
 746
 747 /* --------------------------------------------------------------------- */
 748
 749 static struct proc_dir_entry *usbdir = NULL;
 750
 751 int __init usbfs_init(void)
 752 {
 753         int retval;
 754
 755         retval = register_filesystem(&usb_fs_type);
 756         if (retval)
 757                 return retval;
 758
 759         usb_register_notify(&usbfs_nb);
 760
 761         /* create mount point for usbfs */
 762         usbdir = proc_mkdir("bus/usb", NULL);
 763
 764         return 0;
 765 }
 766
 767 void usbfs_cleanup(void)
 768 {
 769         usb_unregister_notify(&usbfs_nb);
 770         unregister_filesystem(&usb_fs_type);
 771         if (usbdir)
 772                 remove_proc_entry("bus/usb", NULL);
 773 }
 774