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V4L/DVB (6715): ivtv: Remove unnecessary register update
[linux-2.6/verdex.git] / drivers / usb / core / inode.c
blobcd4f11157280de78cd5e73e82f043bde7d247182
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
45 static struct super_operations usbfs_ops;
46 static const struct file_operations default_file_operations;
47 static struct vfsmount *usbfs_mount;
48 static int usbfs_mount_count; /* = 0 */
49 static int ignore_mount = 0;
50
51 static struct dentry *devices_usbfs_dentry;
52 static int num_buses; /* = 0 */
53
54 static uid_t devuid; /* = 0 */
55 static uid_t busuid; /* = 0 */
56 static uid_t listuid; /* = 0 */
57 static gid_t devgid; /* = 0 */
58 static gid_t busgid; /* = 0 */
59 static gid_t listgid; /* = 0 */
60 static umode_t devmode = S_IWUSR | S_IRUGO;
61 static umode_t busmode = S_IXUGO | S_IRUGO;
62 static umode_t listmode = S_IRUGO;
63
64 enum {
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
71 static 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
84 static 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
163 static 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
170 static 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
177 static 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
194 static 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
223 static 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
243 static 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 */
273 static 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
290 static 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
301 static 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
307 static inline int usbfs_positive (struct dentry *dentry)
308 {
309 return dentry->d_inode && !d_unhashed(dentry);
310 }
311
312 static 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
330 static 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
341 static 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 */
365 static ssize_t default_read_file (struct file *file, char __user *buf,
366 size_t count, loff_t *ppos)
367 {
368 return 0;
369 }
370
371 static 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
377 static 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
402 static 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
410 static 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
417 static struct super_operations usbfs_ops = {
418 .statfs = simple_statfs,
419 .drop_inode = generic_delete_inode,
420 .remount_fs = remount,
421 };
422
423 static 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 */
459 static 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
495 static 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
522 static 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
544 static 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
550 static 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
559 static 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
591 error_clean_mounts:
592 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
593 exit:
594 return retval;
595 }
596
597 static 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
605 void 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
616 static 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
641 static 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
655 static 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
683 static 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
706 static 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
727 static struct notifier_block usbfs_nb = {
728 .notifier_call = usbfs_notify,
729 };
730
731 /* --------------------------------------------------------------------- */
732
733 static struct proc_dir_entry *usbdir = NULL;
734
735 int __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
751 void 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
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