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 <asm/byteorder.h>
  44 #include "usb.h"
  45 #include "hcd.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         lock_kernel();
 269
 270         if (usbfs_mount && usbfs_mount->mnt_sb)
 271                 update_sb(usbfs_mount->mnt_sb);
 272
 273         unlock_kernel();
 274
 275         return 0;
 276 }
 277
 278 static struct inode *usbfs_get_inode (struct super_block *sb, int mode, dev_t dev)
 279 {
 280         struct inode *inode = new_inode(sb);
 281
 282         if (inode) {
 283                 inode->i_mode = mode;
 284                 inode->i_uid = current_fsuid();
 285                 inode->i_gid = current_fsgid();
 286                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 287                 switch (mode & S_IFMT) {
 288                 default:
 289                         init_special_inode(inode, mode, dev);
 290                         break;
 291                 case S_IFREG:
 292                         inode->i_fop = &default_file_operations;
 293                         break;
 294                 case S_IFDIR:
 295                         inode->i_op = &simple_dir_inode_operations;
 296                         inode->i_fop = &simple_dir_operations;
 297
 298                         /* directory inodes start off with i_nlink == 2 (for "." entry) */
 299                         inc_nlink(inode);
 300                         break;
 301                 }
 302         }
 303         return inode;
 304 }
 305
 306 /* SMP-safe */
 307 static int usbfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
 308                         dev_t dev)
 309 {
 310         struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
 311         int error = -EPERM;
 312
 313         if (dentry->d_inode)
 314                 return -EEXIST;
 315
 316         if (inode) {
 317                 d_instantiate(dentry, inode);
 318                 dget(dentry);
 319                 error = 0;
 320         }
 321         return error;
 322 }
 323
 324 static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
 325 {
 326         int res;
 327
 328         mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
 329         res = usbfs_mknod (dir, dentry, mode, 0);
 330         if (!res)
 331                 inc_nlink(dir);
 332         return res;
 333 }
 334
 335 static int usbfs_create (struct inode *dir, struct dentry *dentry, int mode)
 336 {
 337         mode = (mode & S_IALLUGO) | S_IFREG;
 338         return usbfs_mknod (dir, dentry, mode, 0);
 339 }
 340
 341 static inline int usbfs_positive (struct dentry *dentry)
 342 {
 343         return dentry->d_inode && !d_unhashed(dentry);
 344 }
 345
 346 static int usbfs_empty (struct dentry *dentry)
 347 {
 348         struct list_head *list;
 349
 350         spin_lock(&dcache_lock);
 351
 352         list_for_each(list, &dentry->d_subdirs) {
 353                 struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
 354                 if (usbfs_positive(de)) {
 355                         spin_unlock(&dcache_lock);
 356                         return 0;
 357                 }
 358         }
 359
 360         spin_unlock(&dcache_lock);
 361         return 1;
 362 }
 363
 364 static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
 365 {
 366         struct inode *inode = dentry->d_inode;
 367         mutex_lock(&inode->i_mutex);
 368         drop_nlink(dentry->d_inode);
 369         dput(dentry);
 370         mutex_unlock(&inode->i_mutex);
 371         d_delete(dentry);
 372         return 0;
 373 }
 374
 375 static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
 376 {
 377         int error = -ENOTEMPTY;
 378         struct inode * inode = dentry->d_inode;
 379
 380         mutex_lock(&inode->i_mutex);
 381         dentry_unhash(dentry);
 382         if (usbfs_empty(dentry)) {
 383                 dont_mount(dentry);
 384                 drop_nlink(dentry->d_inode);
 385                 drop_nlink(dentry->d_inode);
 386                 dput(dentry);
 387                 inode->i_flags |= S_DEAD;
 388                 drop_nlink(dir);
 389                 error = 0;
 390         }
 391         mutex_unlock(&inode->i_mutex);
 392         if (!error)
 393                 d_delete(dentry);
 394         dput(dentry);
 395         return error;
 396 }
 397
 398
 399 /* default file operations */
 400 static ssize_t default_read_file (struct file *file, char __user *buf,
 401                                   size_t count, loff_t *ppos)
 402 {
 403         return 0;
 404 }
 405
 406 static ssize_t default_write_file (struct file *file, const char __user *buf,
 407                                    size_t count, loff_t *ppos)
 408 {
 409         return count;
 410 }
 411
 412 static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
 413 {
 414         loff_t retval = -EINVAL;
 415
 416         mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
 417         switch(orig) {
 418         case 0:
 419                 if (offset > 0) {
 420                         file->f_pos = offset;
 421                         retval = file->f_pos;
 422                 }
 423                 break;
 424         case 1:
 425                 if ((offset + file->f_pos) > 0) {
 426                         file->f_pos += offset;
 427                         retval = file->f_pos;
 428                 }
 429                 break;
 430         default:
 431                 break;
 432         }
 433         mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
 434         return retval;
 435 }
 436
 437 static int default_open (struct inode *inode, struct file *file)
 438 {
 439         if (inode->i_private)
 440                 file->private_data = inode->i_private;
 441
 442         return 0;
 443 }
 444
 445 static const struct file_operations default_file_operations = {
 446         .read =         default_read_file,
 447         .write =        default_write_file,
 448         .open =         default_open,
 449         .llseek =       default_file_lseek,
 450 };
 451
 452 static const struct super_operations usbfs_ops = {
 453         .statfs =       simple_statfs,
 454         .drop_inode =   generic_delete_inode,
 455         .remount_fs =   remount,
 456         .show_options = usbfs_show_options,
 457 };
 458
 459 static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
 460 {
 461         struct inode *inode;
 462         struct dentry *root;
 463
 464         sb->s_blocksize = PAGE_CACHE_SIZE;
 465         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 466         sb->s_magic = USBDEVICE_SUPER_MAGIC;
 467         sb->s_op = &usbfs_ops;
 468         sb->s_time_gran = 1;
 469         inode = usbfs_get_inode(sb, S_IFDIR | 0755, 0);
 470
 471         if (!inode) {
 472                 dbg("%s: could not get inode!",__func__);
 473                 return -ENOMEM;
 474         }
 475
 476         root = d_alloc_root(inode);
 477         if (!root) {
 478                 dbg("%s: could not get root dentry!",__func__);
 479                 iput(inode);
 480                 return -ENOMEM;
 481         }
 482         sb->s_root = root;
 483         return 0;
 484 }
 485
 486 /*
 487  * fs_create_by_name - create a file, given a name
 488  * @name:       name of file
 489  * @mode:       type of file
 490  * @parent:     dentry of directory to create it in
 491  * @dentry:     resulting dentry of file
 492  *
 493  * This function handles both regular files and directories.
 494  */
 495 static int fs_create_by_name (const char *name, mode_t mode,
 496                               struct dentry *parent, struct dentry **dentry)
 497 {
 498         int error = 0;
 499
 500         /* If the parent is not specified, we create it in the root.
 501          * We need the root dentry to do this, which is in the super
 502          * block. A pointer to that is in the struct vfsmount that we
 503          * have around.
 504          */
 505         if (!parent ) {
 506                 if (usbfs_mount && usbfs_mount->mnt_sb) {
 507                         parent = usbfs_mount->mnt_sb->s_root;
 508                 }
 509         }
 510
 511         if (!parent) {
 512                 dbg("Ah! can not find a parent!");
 513                 return -EFAULT;
 514         }
 515
 516         *dentry = NULL;
 517         mutex_lock(&parent->d_inode->i_mutex);
 518         *dentry = lookup_one_len(name, parent, strlen(name));
 519         if (!IS_ERR(*dentry)) {
 520                 if ((mode & S_IFMT) == S_IFDIR)
 521                         error = usbfs_mkdir (parent->d_inode, *dentry, mode);
 522                 else
 523                         error = usbfs_create (parent->d_inode, *dentry, mode);
 524         } else
 525                 error = PTR_ERR(*dentry);
 526         mutex_unlock(&parent->d_inode->i_mutex);
 527
 528         return error;
 529 }
 530
 531 static struct dentry *fs_create_file (const char *name, mode_t mode,
 532                                       struct dentry *parent, void *data,
 533                                       const struct file_operations *fops,
 534                                       uid_t uid, gid_t gid)
 535 {
 536         struct dentry *dentry;
 537         int error;
 538
 539         dbg("creating file '%s'",name);
 540
 541         error = fs_create_by_name (name, mode, parent, &dentry);
 542         if (error) {
 543                 dentry = NULL;
 544         } else {
 545                 if (dentry->d_inode) {
 546                         if (data)
 547                                 dentry->d_inode->i_private = data;
 548                         if (fops)
 549                                 dentry->d_inode->i_fop = fops;
 550                         dentry->d_inode->i_uid = uid;
 551                         dentry->d_inode->i_gid = gid;
 552                 }
 553         }
 554
 555         return dentry;
 556 }
 557
 558 static void fs_remove_file (struct dentry *dentry)
 559 {
 560         struct dentry *parent = dentry->d_parent;
 561
 562         if (!parent || !parent->d_inode)
 563                 return;
 564
 565         mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_PARENT);
 566         if (usbfs_positive(dentry)) {
 567                 if (dentry->d_inode) {
 568                         if (S_ISDIR(dentry->d_inode->i_mode))
 569                                 usbfs_rmdir(parent->d_inode, dentry);
 570                         else
 571                                 usbfs_unlink(parent->d_inode, dentry);
 572                 dput(dentry);
 573                 }
 574         }
 575         mutex_unlock(&parent->d_inode->i_mutex);
 576 }
 577
 578 /* --------------------------------------------------------------------- */
 579
 580 static int usb_get_sb(struct file_system_type *fs_type,
 581         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 582 {
 583         return get_sb_single(fs_type, flags, data, usbfs_fill_super, mnt);
 584 }
 585
 586 static struct file_system_type usb_fs_type = {
 587         .owner =        THIS_MODULE,
 588         .name =         "usbfs",
 589         .get_sb =       usb_get_sb,
 590         .kill_sb =      kill_litter_super,
 591 };
 592
 593 /* --------------------------------------------------------------------- */
 594
 595 static int create_special_files (void)
 596 {
 597         struct dentry *parent;
 598         int retval;
 599
 600         /* the simple_pin_fs calls will call remount with no options
 601          * without this flag that would overwrite the real mount options (if any)
 602          */
 603         ignore_mount = 1;
 604
 605         /* create the devices special file */
 606         retval = simple_pin_fs(&usb_fs_type, &usbfs_mount, &usbfs_mount_count);
 607         if (retval) {
 608                 printk(KERN_ERR "Unable to get usbfs mount\n");
 609                 goto exit;
 610         }
 611
 612         ignore_mount = 0;
 613
 614         parent = usbfs_mount->mnt_sb->s_root;
 615         devices_usbfs_dentry = fs_create_file ("devices",
 616                                                listmode | S_IFREG, parent,
 617                                                NULL, &usbfs_devices_fops,
 618                                                listuid, listgid);
 619         if (devices_usbfs_dentry == NULL) {
 620                 printk(KERN_ERR "Unable to create devices usbfs file\n");
 621                 retval = -ENODEV;
 622                 goto error_clean_mounts;
 623         }
 624
 625         goto exit;
 626
 627 error_clean_mounts:
 628         simple_release_fs(&usbfs_mount, &usbfs_mount_count);
 629 exit:
 630         return retval;
 631 }
 632
 633 static void remove_special_files (void)
 634 {
 635         if (devices_usbfs_dentry)
 636                 fs_remove_file (devices_usbfs_dentry);
 637         devices_usbfs_dentry = NULL;
 638         simple_release_fs(&usbfs_mount, &usbfs_mount_count);
 639 }
 640
 641 void usbfs_update_special (void)
 642 {
 643         struct inode *inode;
 644
 645         if (devices_usbfs_dentry) {
 646                 inode = devices_usbfs_dentry->d_inode;
 647                 if (inode)
 648                         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 649         }
 650 }
 651
 652 static void usbfs_add_bus(struct usb_bus *bus)
 653 {
 654         struct dentry *parent;
 655         char name[8];
 656         int retval;
 657
 658         /* create the special files if this is the first bus added */
 659         if (num_buses == 0) {
 660                 retval = create_special_files();
 661                 if (retval)
 662                         return;
 663         }
 664         ++num_buses;
 665
 666         sprintf (name, "%03d", bus->busnum);
 667
 668         parent = usbfs_mount->mnt_sb->s_root;
 669         bus->usbfs_dentry = fs_create_file (name, busmode | S_IFDIR, parent,
 670                                             bus, NULL, busuid, busgid);
 671         if (bus->usbfs_dentry == NULL) {
 672                 printk(KERN_ERR "Error creating usbfs bus entry\n");
 673                 return;
 674         }
 675 }
 676
 677 static void usbfs_remove_bus(struct usb_bus *bus)
 678 {
 679         if (bus->usbfs_dentry) {
 680                 fs_remove_file (bus->usbfs_dentry);
 681                 bus->usbfs_dentry = NULL;
 682         }
 683
 684         --num_buses;
 685         if (num_buses <= 0) {
 686                 remove_special_files();
 687                 num_buses = 0;
 688         }
 689 }
 690
 691 static void usbfs_add_device(struct usb_device *dev)
 692 {
 693         char name[8];
 694         int i;
 695         int i_size;
 696
 697         sprintf (name, "%03d", dev->devnum);
 698         dev->usbfs_dentry = fs_create_file (name, devmode | S_IFREG,
 699                                             dev->bus->usbfs_dentry, dev,
 700                                             &usbdev_file_operations,
 701                                             devuid, devgid);
 702         if (dev->usbfs_dentry == NULL) {
 703                 printk(KERN_ERR "Error creating usbfs device entry\n");
 704                 return;
 705         }
 706
 707         /* Set the size of the device's file to be
 708          * equal to the size of the device descriptors. */
 709         i_size = sizeof (struct usb_device_descriptor);
 710         for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
 711                 struct usb_config_descriptor *config =
 712                         (struct usb_config_descriptor *)dev->rawdescriptors[i];
 713                 i_size += le16_to_cpu(config->wTotalLength);
 714         }
 715         if (dev->usbfs_dentry->d_inode)
 716                 dev->usbfs_dentry->d_inode->i_size = i_size;
 717 }
 718
 719 static void usbfs_remove_device(struct usb_device *dev)
 720 {
 721         if (dev->usbfs_dentry) {
 722                 fs_remove_file (dev->usbfs_dentry);
 723                 dev->usbfs_dentry = NULL;
 724         }
 725 }
 726
 727 static int usbfs_notify(struct notifier_block *self, unsigned long action, void *dev)
 728 {
 729         switch (action) {
 730         case USB_DEVICE_ADD:
 731                 usbfs_add_device(dev);
 732                 break;
 733         case USB_DEVICE_REMOVE:
 734                 usbfs_remove_device(dev);
 735                 break;
 736         case USB_BUS_ADD:
 737                 usbfs_add_bus(dev);
 738                 break;
 739         case USB_BUS_REMOVE:
 740                 usbfs_remove_bus(dev);
 741         }
 742
 743         usbfs_update_special();
 744         usbfs_conn_disc_event();
 745         return NOTIFY_OK;
 746 }
 747
 748 static struct notifier_block usbfs_nb = {
 749         .notifier_call =        usbfs_notify,
 750 };
 751
 752 /* --------------------------------------------------------------------- */
 753
 754 static struct proc_dir_entry *usbdir = NULL;
 755
 756 int __init usbfs_init(void)
 757 {
 758         int retval;
 759
 760         retval = register_filesystem(&usb_fs_type);
 761         if (retval)
 762                 return retval;
 763
 764         usb_register_notify(&usbfs_nb);
 765
 766         /* create mount point for usbfs */
 767         usbdir = proc_mkdir("bus/usb", NULL);
 768
 769         return 0;
 770 }
 771
 772 void usbfs_cleanup(void)
 773 {
 774         usb_unregister_notify(&usbfs_nb);
 775         unregister_filesystem(&usb_fs_type);
 776         if (usbdir)
 777                 remove_proc_entry("bus/usb", NULL);
 778 }
 779