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