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 <linux/smp_lock.h>
  43 #include <linux/usb/hcd.h>
  44 #include <asm/byteorder.h>
  45 #include "usb.h"
  46
  47 #define USBFS_DEFAULT_DEVMODE (S_IWUSR | S_IRUGO)
  48 #define USBFS_DEFAULT_BUSMODE (S_IXUGO | S_IRUGO)
  49 #define USBFS_DEFAULT_LISTMODE S_IRUGO
  50
  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 const 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                         printk(KERN_ERR "usbfs: unrecognised mount option "
 184                                "\"%s\" 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                                 printk(KERN_WARNING "usbfs: Unknown node %s "
 244                                        "mode %x found on remount!\n",
 245                                        bus->d_name.name, bus->d_inode->i_mode);
 246                                 break;
 247                         }
 248                 }
 249         }
 250
 251         mutex_unlock(&root->d_inode->i_mutex);
 252 }
 253
 254 static int remount(struct super_block *sb, int *flags, char *data)
 255 {
 256         /* If this is not a real mount,
 257          * i.e. it's a simple_pin_fs from create_special_files,
 258          * then ignore it.
 259          */
 260         if (ignore_mount)
 261                 return 0;
 262
 263         if (parse_options(sb, data)) {
 264                 printk(KERN_WARNING "usbfs: mount parameter error.\n");
 265                 return -EINVAL;
 266         }
 267
 268         if (usbfs_mount && usbfs_mount->mnt_sb)
 269                 update_sb(usbfs_mount->mnt_sb);
 270
 271         return 0;
 272 }
 273
 274 static struct inode *usbfs_get_inode (struct super_block *sb, int mode, dev_t dev)
 275 {
 276         struct inode *inode = new_inode(sb);
 277
 278         if (inode) {
 279                 inode->i_ino = get_next_ino();
 280                 inode->i_mode = mode;
 281                 inode->i_uid = current_fsuid();
 282                 inode->i_gid = current_fsgid();
 283                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 284                 switch (mode & S_IFMT) {
 285                 default:
 286                         init_special_inode(inode, mode, dev);
 287                         break;
 288                 case S_IFREG:
 289                         inode->i_fop = &default_file_operations;
 290                         break;
 291                 case S_IFDIR:
 292                         inode->i_op = &simple_dir_inode_operations;
 293                         inode->i_fop = &simple_dir_operations;
 294
 295                         /* directory inodes start off with i_nlink == 2 (for "." entry) */
 296                         inc_nlink(inode);
 297                         break;
 298                 }
 299         }
 300         return inode;
 301 }
 302
 303 /* SMP-safe */
 304 static int usbfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
 305                         dev_t dev)
 306 {
 307         struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
 308         int error = -EPERM;
 309
 310         if (dentry->d_inode)
 311                 return -EEXIST;
 312
 313         if (inode) {
 314                 d_instantiate(dentry, inode);
 315                 dget(dentry);
 316                 error = 0;
 317         }
 318         return error;
 319 }
 320
 321 static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
 322 {
 323         int res;
 324
 325         mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
 326         res = usbfs_mknod (dir, dentry, mode, 0);
 327         if (!res)
 328                 inc_nlink(dir);
 329         return res;
 330 }
 331
 332 static int usbfs_create (struct inode *dir, struct dentry *dentry, int mode)
 333 {
 334         mode = (mode & S_IALLUGO) | S_IFREG;
 335         return usbfs_mknod (dir, dentry, mode, 0);
 336 }
 337
 338 static inline int usbfs_positive (struct dentry *dentry)
 339 {
 340         return dentry->d_inode && !d_unhashed(dentry);
 341 }
 342
 343 static int usbfs_empty (struct dentry *dentry)
 344 {
 345         struct list_head *list;
 346
 347         spin_lock(&dcache_lock);
 348
 349         list_for_each(list, &dentry->d_subdirs) {
 350                 struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
 351                 if (usbfs_positive(de)) {
 352                         spin_unlock(&dcache_lock);
 353                         return 0;
 354                 }
 355         }
 356
 357         spin_unlock(&dcache_lock);
 358         return 1;
 359 }
 360
 361 static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
 362 {
 363         struct inode *inode = dentry->d_inode;
 364         mutex_lock(&inode->i_mutex);
 365         drop_nlink(dentry->d_inode);
 366         dput(dentry);
 367         mutex_unlock(&inode->i_mutex);
 368         d_delete(dentry);
 369         return 0;
 370 }
 371
 372 static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
 373 {
 374         int error = -ENOTEMPTY;
 375         struct inode * inode = dentry->d_inode;
 376
 377         mutex_lock(&inode->i_mutex);
 378         dentry_unhash(dentry);
 379         if (usbfs_empty(dentry)) {
 380                 dont_mount(dentry);
 381                 drop_nlink(dentry->d_inode);
 382                 drop_nlink(dentry->d_inode);
 383                 dput(dentry);
 384                 inode->i_flags |= S_DEAD;
 385                 drop_nlink(dir);
 386                 error = 0;
 387         }
 388         mutex_unlock(&inode->i_mutex);
 389         if (!error)
 390                 d_delete(dentry);
 391         dput(dentry);
 392         return error;
 393 }
 394
 395
 396 /* default file operations */
 397 static ssize_t default_read_file (struct file *file, char __user *buf,
 398                                   size_t count, loff_t *ppos)
 399 {
 400         return 0;
 401 }
 402
 403 static ssize_t default_write_file (struct file *file, const char __user *buf,
 404                                    size_t count, loff_t *ppos)
 405 {
 406         return count;
 407 }
 408
 409 static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
 410 {
 411         loff_t retval = -EINVAL;
 412
 413         mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
 414         switch(orig) {
 415         case 0:
 416                 if (offset > 0) {
 417                         file->f_pos = offset;
 418                         retval = file->f_pos;
 419                 }
 420                 break;
 421         case 1:
 422                 if ((offset + file->f_pos) > 0) {
 423                         file->f_pos += offset;
 424                         retval = file->f_pos;
 425                 }
 426                 break;
 427         default:
 428                 break;
 429         }
 430         mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
 431         return retval;
 432 }
 433
 434 static int default_open (struct inode *inode, struct file *file)
 435 {
 436         if (inode->i_private)
 437                 file->private_data = inode->i_private;
 438
 439         return 0;
 440 }
 441
 442 static const struct file_operations default_file_operations = {
 443         .read =         default_read_file,
 444         .write =        default_write_file,
 445         .open =         default_open,
 446         .llseek =       default_file_lseek,
 447 };
 448
 449 static const struct super_operations usbfs_ops = {
 450         .statfs =       simple_statfs,
 451         .drop_inode =   generic_delete_inode,
 452         .remount_fs =   remount,
 453         .show_options = usbfs_show_options,
 454 };
 455
 456 static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
 457 {
 458         struct inode *inode;
 459         struct dentry *root;
 460
 461         sb->s_blocksize = PAGE_CACHE_SIZE;
 462         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 463         sb->s_magic = USBDEVICE_SUPER_MAGIC;
 464         sb->s_op = &usbfs_ops;
 465         sb->s_time_gran = 1;
 466         inode = usbfs_get_inode(sb, S_IFDIR | 0755, 0);
 467
 468         if (!inode) {
 469                 dbg("%s: could not get inode!",__func__);
 470                 return -ENOMEM;
 471         }
 472
 473         root = d_alloc_root(inode);
 474         if (!root) {
 475                 dbg("%s: could not get root dentry!",__func__);
 476                 iput(inode);
 477                 return -ENOMEM;
 478         }
 479         sb->s_root = root;
 480         return 0;
 481 }
 482
 483 /*
 484  * fs_create_by_name - create a file, given a name
 485  * @name:       name of file
 486  * @mode:       type of file
 487  * @parent:     dentry of directory to create it in
 488  * @dentry:     resulting dentry of file
 489  *
 490  * This function handles both regular files and directories.
 491  */
 492 static int fs_create_by_name (const char *name, mode_t mode,
 493                               struct dentry *parent, struct dentry **dentry)
 494 {
 495         int error = 0;
 496
 497         /* If the parent is not specified, we create it in the root.
 498          * We need the root dentry to do this, which is in the super
 499          * block. A pointer to that is in the struct vfsmount that we
 500          * have around.
 501          */
 502         if (!parent ) {
 503                 if (usbfs_mount && usbfs_mount->mnt_sb) {
 504                         parent = usbfs_mount->mnt_sb->s_root;
 505                 }
 506         }
 507
 508         if (!parent) {
 509                 dbg("Ah! can not find a parent!");
 510                 return -EFAULT;
 511         }
 512
 513         *dentry = NULL;
 514         mutex_lock(&parent->d_inode->i_mutex);
 515         *dentry = lookup_one_len(name, parent, strlen(name));
 516         if (!IS_ERR(*dentry)) {
 517                 if ((mode & S_IFMT) == S_IFDIR)
 518                         error = usbfs_mkdir (parent->d_inode, *dentry, mode);
 519                 else
 520                         error = usbfs_create (parent->d_inode, *dentry, mode);
 521         } else
 522                 error = PTR_ERR(*dentry);
 523         mutex_unlock(&parent->d_inode->i_mutex);
 524
 525         return error;
 526 }
 527
 528 static struct dentry *fs_create_file (const char *name, mode_t mode,
 529                                       struct dentry *parent, void *data,
 530                                       const struct file_operations *fops,
 531                                       uid_t uid, gid_t gid)
 532 {
 533         struct dentry *dentry;
 534         int error;
 535
 536         dbg("creating file '%s'",name);
 537
 538         error = fs_create_by_name (name, mode, parent, &dentry);
 539         if (error) {
 540                 dentry = NULL;
 541         } else {
 542                 if (dentry->d_inode) {
 543                         if (data)
 544                                 dentry->d_inode->i_private = data;
 545                         if (fops)
 546                                 dentry->d_inode->i_fop = fops;
 547                         dentry->d_inode->i_uid = uid;
 548                         dentry->d_inode->i_gid = gid;
 549                 }
 550         }
 551
 552         return dentry;
 553 }
 554
 555 static void fs_remove_file (struct dentry *dentry)
 556 {
 557         struct dentry *parent = dentry->d_parent;
 558
 559         if (!parent || !parent->d_inode)
 560                 return;
 561
 562         mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_PARENT);
 563         if (usbfs_positive(dentry)) {
 564                 if (dentry->d_inode) {
 565                         if (S_ISDIR(dentry->d_inode->i_mode))
 566                                 usbfs_rmdir(parent->d_inode, dentry);
 567                         else
 568                                 usbfs_unlink(parent->d_inode, dentry);
 569                 dput(dentry);
 570                 }
 571         }
 572         mutex_unlock(&parent->d_inode->i_mutex);
 573 }
 574
 575 /* --------------------------------------------------------------------- */
 576
 577 static struct dentry *usb_mount(struct file_system_type *fs_type,
 578         int flags, const char *dev_name, void *data)
 579 {
 580         return mount_single(fs_type, flags, data, usbfs_fill_super);
 581 }
 582
 583 static struct file_system_type usb_fs_type = {
 584         .owner =        THIS_MODULE,
 585         .name =         "usbfs",
 586         .mount =        usb_mount,
 587         .kill_sb =      kill_litter_super,
 588 };
 589
 590 /* --------------------------------------------------------------------- */
 591
 592 static int create_special_files (void)
 593 {
 594         struct dentry *parent;
 595         int retval;
 596
 597         /* the simple_pin_fs calls will call remount with no options
 598          * without this flag that would overwrite the real mount options (if any)
 599          */
 600         ignore_mount = 1;
 601
 602         /* create the devices special file */
 603         retval = simple_pin_fs(&usb_fs_type, &usbfs_mount, &usbfs_mount_count);
 604         if (retval) {
 605                 printk(KERN_ERR "Unable to get usbfs mount\n");
 606                 goto exit;
 607         }
 608
 609         ignore_mount = 0;
 610
 611         parent = usbfs_mount->mnt_sb->s_root;
 612         devices_usbfs_dentry = fs_create_file ("devices",
 613                                                listmode | S_IFREG, parent,
 614                                                NULL, &usbfs_devices_fops,
 615                                                listuid, listgid);
 616         if (devices_usbfs_dentry == NULL) {
 617                 printk(KERN_ERR "Unable to create devices usbfs file\n");
 618                 retval = -ENODEV;
 619                 goto error_clean_mounts;
 620         }
 621
 622         goto exit;
 623
 624 error_clean_mounts:
 625         simple_release_fs(&usbfs_mount, &usbfs_mount_count);
 626 exit:
 627         return retval;
 628 }
 629
 630 static void remove_special_files (void)
 631 {
 632         if (devices_usbfs_dentry)
 633                 fs_remove_file (devices_usbfs_dentry);
 634         devices_usbfs_dentry = NULL;
 635         simple_release_fs(&usbfs_mount, &usbfs_mount_count);
 636 }
 637
 638 void usbfs_update_special (void)
 639 {
 640         struct inode *inode;
 641
 642         if (devices_usbfs_dentry) {
 643                 inode = devices_usbfs_dentry->d_inode;
 644                 if (inode)
 645                         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 646         }
 647 }
 648
 649 static void usbfs_add_bus(struct usb_bus *bus)
 650 {
 651         struct dentry *parent;
 652         char name[8];
 653         int retval;
 654
 655         /* create the special files if this is the first bus added */
 656         if (num_buses == 0) {
 657                 retval = create_special_files();
 658                 if (retval)
 659                         return;
 660         }
 661         ++num_buses;
 662
 663         sprintf (name, "%03d", bus->busnum);
 664
 665         parent = usbfs_mount->mnt_sb->s_root;
 666         bus->usbfs_dentry = fs_create_file (name, busmode | S_IFDIR, parent,
 667                                             bus, NULL, busuid, busgid);
 668         if (bus->usbfs_dentry == NULL) {
 669                 printk(KERN_ERR "Error creating usbfs bus entry\n");
 670                 return;
 671         }
 672 }
 673
 674 static void usbfs_remove_bus(struct usb_bus *bus)
 675 {
 676         if (bus->usbfs_dentry) {
 677                 fs_remove_file (bus->usbfs_dentry);
 678                 bus->usbfs_dentry = NULL;
 679         }
 680
 681         --num_buses;
 682         if (num_buses <= 0) {
 683                 remove_special_files();
 684                 num_buses = 0;
 685         }
 686 }
 687
 688 static void usbfs_add_device(struct usb_device *dev)
 689 {
 690         char name[8];
 691         int i;
 692         int i_size;
 693
 694         sprintf (name, "%03d", dev->devnum);
 695         dev->usbfs_dentry = fs_create_file (name, devmode | S_IFREG,
 696                                             dev->bus->usbfs_dentry, dev,
 697                                             &usbdev_file_operations,
 698                                             devuid, devgid);
 699         if (dev->usbfs_dentry == NULL) {
 700                 printk(KERN_ERR "Error creating usbfs device entry\n");
 701                 return;
 702         }
 703
 704         /* Set the size of the device's file to be
 705          * equal to the size of the device descriptors. */
 706         i_size = sizeof (struct usb_device_descriptor);
 707         for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
 708                 struct usb_config_descriptor *config =
 709                         (struct usb_config_descriptor *)dev->rawdescriptors[i];
 710                 i_size += le16_to_cpu(config->wTotalLength);
 711         }
 712         if (dev->usbfs_dentry->d_inode)
 713                 dev->usbfs_dentry->d_inode->i_size = i_size;
 714 }
 715
 716 static void usbfs_remove_device(struct usb_device *dev)
 717 {
 718         if (dev->usbfs_dentry) {
 719                 fs_remove_file (dev->usbfs_dentry);
 720                 dev->usbfs_dentry = NULL;
 721         }
 722 }
 723
 724 static int usbfs_notify(struct notifier_block *self, unsigned long action, void *dev)
 725 {
 726         switch (action) {
 727         case USB_DEVICE_ADD:
 728                 usbfs_add_device(dev);
 729                 break;
 730         case USB_DEVICE_REMOVE:
 731                 usbfs_remove_device(dev);
 732                 break;
 733         case USB_BUS_ADD:
 734                 usbfs_add_bus(dev);
 735                 break;
 736         case USB_BUS_REMOVE:
 737                 usbfs_remove_bus(dev);
 738         }
 739
 740         usbfs_update_special();
 741         usbfs_conn_disc_event();
 742         return NOTIFY_OK;
 743 }
 744
 745 static struct notifier_block usbfs_nb = {
 746         .notifier_call =        usbfs_notify,
 747 };
 748
 749 /* --------------------------------------------------------------------- */
 750
 751 static struct proc_dir_entry *usbdir = NULL;
 752
 753 int __init usbfs_init(void)
 754 {
 755         int retval;
 756
 757         retval = register_filesystem(&usb_fs_type);
 758         if (retval)
 759                 return retval;
 760
 761         usb_register_notify(&usbfs_nb);
 762
 763         /* create mount point for usbfs */
 764         usbdir = proc_mkdir("bus/usb", NULL);
 765
 766         return 0;
 767 }
 768
 769 void usbfs_cleanup(void)
 770 {
 771         usb_unregister_notify(&usbfs_nb);
 772         unregister_filesystem(&usb_fs_type);
 773         if (usbdir)
 774                 remove_proc_entry("bus/usb", NULL);
 775 }
 776