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