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