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Merge tag 'v3.3.7' into 3.3/master
[zen-stable.git] / drivers / usb / core / inode.c
blob9e186f3da839c8d577438c447f60629153f89eab
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/usb/hcd.h>
43 #include <asm/byteorder.h>
44 #include "usb.h"
45
46 #define USBFS_DEFAULT_DEVMODE (S_IWUSR | S_IRUGO)
47 #define USBFS_DEFAULT_BUSMODE (S_IXUGO | S_IRUGO)
48 #define USBFS_DEFAULT_LISTMODE S_IRUGO
49
50 static const struct file_operations default_file_operations;
51 static struct vfsmount *usbfs_mount;
52 static int usbfs_mount_count; /* = 0 */
53 static int ignore_mount = 0;
54
55 static struct dentry *devices_usbfs_dentry;
56 static int num_buses; /* = 0 */
57
58 static uid_t devuid; /* = 0 */
59 static uid_t busuid; /* = 0 */
60 static uid_t listuid; /* = 0 */
61 static gid_t devgid; /* = 0 */
62 static gid_t busgid; /* = 0 */
63 static gid_t listgid; /* = 0 */
64 static umode_t devmode = USBFS_DEFAULT_DEVMODE;
65 static umode_t busmode = USBFS_DEFAULT_BUSMODE;
66 static umode_t listmode = USBFS_DEFAULT_LISTMODE;
67
68 static int usbfs_show_options(struct seq_file *seq, struct dentry *root)
69 {
70 if (devuid != 0)
71 seq_printf(seq, ",devuid=%u", devuid);
72 if (devgid != 0)
73 seq_printf(seq, ",devgid=%u", devgid);
74 if (devmode != USBFS_DEFAULT_DEVMODE)
75 seq_printf(seq, ",devmode=%o", devmode);
76 if (busuid != 0)
77 seq_printf(seq, ",busuid=%u", busuid);
78 if (busgid != 0)
79 seq_printf(seq, ",busgid=%u", busgid);
80 if (busmode != USBFS_DEFAULT_BUSMODE)
81 seq_printf(seq, ",busmode=%o", busmode);
82 if (listuid != 0)
83 seq_printf(seq, ",listuid=%u", listuid);
84 if (listgid != 0)
85 seq_printf(seq, ",listgid=%u", listgid);
86 if (listmode != USBFS_DEFAULT_LISTMODE)
87 seq_printf(seq, ",listmode=%o", listmode);
88
89 return 0;
90 }
91
92 enum {
93 Opt_devuid, Opt_devgid, Opt_devmode,
94 Opt_busuid, Opt_busgid, Opt_busmode,
95 Opt_listuid, Opt_listgid, Opt_listmode,
96 Opt_err,
97 };
98
99 static const match_table_t tokens = {
100 {Opt_devuid, "devuid=%u"},
101 {Opt_devgid, "devgid=%u"},
102 {Opt_devmode, "devmode=%o"},
103 {Opt_busuid, "busuid=%u"},
104 {Opt_busgid, "busgid=%u"},
105 {Opt_busmode, "busmode=%o"},
106 {Opt_listuid, "listuid=%u"},
107 {Opt_listgid, "listgid=%u"},
108 {Opt_listmode, "listmode=%o"},
109 {Opt_err, NULL}
110 };
111
112 static int parse_options(struct super_block *s, char *data)
113 {
114 char *p;
115 int option;
116
117 /* (re)set to defaults. */
118 devuid = 0;
119 busuid = 0;
120 listuid = 0;
121 devgid = 0;
122 busgid = 0;
123 listgid = 0;
124 devmode = USBFS_DEFAULT_DEVMODE;
125 busmode = USBFS_DEFAULT_BUSMODE;
126 listmode = USBFS_DEFAULT_LISTMODE;
127
128 while ((p = strsep(&data, ",")) != NULL) {
129 substring_t args[MAX_OPT_ARGS];
130 int token;
131 if (!*p)
132 continue;
133
134 token = match_token(p, tokens, args);
135 switch (token) {
136 case Opt_devuid:
137 if (match_int(&args[0], &option))
138 return -EINVAL;
139 devuid = option;
140 break;
141 case Opt_devgid:
142 if (match_int(&args[0], &option))
143 return -EINVAL;
144 devgid = option;
145 break;
146 case Opt_devmode:
147 if (match_octal(&args[0], &option))
148 return -EINVAL;
149 devmode = option & S_IRWXUGO;
150 break;
151 case Opt_busuid:
152 if (match_int(&args[0], &option))
153 return -EINVAL;
154 busuid = option;
155 break;
156 case Opt_busgid:
157 if (match_int(&args[0], &option))
158 return -EINVAL;
159 busgid = option;
160 break;
161 case Opt_busmode:
162 if (match_octal(&args[0], &option))
163 return -EINVAL;
164 busmode = option & S_IRWXUGO;
165 break;
166 case Opt_listuid:
167 if (match_int(&args[0], &option))
168 return -EINVAL;
169 listuid = option;
170 break;
171 case Opt_listgid:
172 if (match_int(&args[0], &option))
173 return -EINVAL;
174 listgid = option;
175 break;
176 case Opt_listmode:
177 if (match_octal(&args[0], &option))
178 return -EINVAL;
179 listmode = option & S_IRWXUGO;
180 break;
181 default:
182 printk(KERN_ERR "usbfs: unrecognised mount option "
183 "\"%s\" or missing value\n", p);
184 return -EINVAL;
185 }
186 }
187
188 return 0;
189 }
190
191 static void update_special(struct dentry *special)
192 {
193 special->d_inode->i_uid = listuid;
194 special->d_inode->i_gid = listgid;
195 special->d_inode->i_mode = S_IFREG | listmode;
196 }
197
198 static void update_dev(struct dentry *dev)
199 {
200 dev->d_inode->i_uid = devuid;
201 dev->d_inode->i_gid = devgid;
202 dev->d_inode->i_mode = S_IFREG | devmode;
203 }
204
205 static void update_bus(struct dentry *bus)
206 {
207 struct dentry *dev = NULL;
208
209 bus->d_inode->i_uid = busuid;
210 bus->d_inode->i_gid = busgid;
211 bus->d_inode->i_mode = S_IFDIR | busmode;
212
213 mutex_lock(&bus->d_inode->i_mutex);
214
215 list_for_each_entry(dev, &bus->d_subdirs, d_u.d_child)
216 if (dev->d_inode)
217 update_dev(dev);
218
219 mutex_unlock(&bus->d_inode->i_mutex);
220 }
221
222 static void update_sb(struct super_block *sb)
223 {
224 struct dentry *root = sb->s_root;
225 struct dentry *bus = NULL;
226
227 if (!root)
228 return;
229
230 mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT);
231
232 list_for_each_entry(bus, &root->d_subdirs, d_u.d_child) {
233 if (bus->d_inode) {
234 switch (S_IFMT & bus->d_inode->i_mode) {
235 case S_IFDIR:
236 update_bus(bus);
237 break;
238 case S_IFREG:
239 update_special(bus);
240 break;
241 default:
242 printk(KERN_WARNING "usbfs: Unknown node %s "
243 "mode %x found on remount!\n",
244 bus->d_name.name, bus->d_inode->i_mode);
245 break;
246 }
247 }
248 }
249
250 mutex_unlock(&root->d_inode->i_mutex);
251 }
252
253 static int remount(struct super_block *sb, int *flags, char *data)
254 {
255 /* If this is not a real mount,
256 * i.e. it's a simple_pin_fs from create_special_files,
257 * then ignore it.
258 */
259 if (ignore_mount)
260 return 0;
261
262 if (parse_options(sb, data)) {
263 printk(KERN_WARNING "usbfs: mount parameter error.\n");
264 return -EINVAL;
265 }
266
267 if (usbfs_mount)
268 update_sb(usbfs_mount->mnt_sb);
269
270 return 0;
271 }
272
273 static struct inode *usbfs_get_inode (struct super_block *sb, umode_t mode, dev_t dev)
274 {
275 struct inode *inode = new_inode(sb);
276
277 if (inode) {
278 inode->i_ino = get_next_ino();
279 inode_init_owner(inode, NULL, mode);
280 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
281 switch (mode & S_IFMT) {
282 default:
283 init_special_inode(inode, mode, dev);
284 break;
285 case S_IFREG:
286 inode->i_fop = &default_file_operations;
287 break;
288 case S_IFDIR:
289 inode->i_op = &simple_dir_inode_operations;
290 inode->i_fop = &simple_dir_operations;
291
292 /* directory inodes start off with i_nlink == 2 (for "." entry) */
293 inc_nlink(inode);
294 break;
295 }
296 }
297 return inode;
298 }
299
300 /* SMP-safe */
301 static int usbfs_mknod (struct inode *dir, struct dentry *dentry, umode_t mode,
302 dev_t dev)
303 {
304 struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
305 int error = -EPERM;
306
307 if (dentry->d_inode)
308 return -EEXIST;
309
310 if (inode) {
311 d_instantiate(dentry, inode);
312 dget(dentry);
313 error = 0;
314 }
315 return error;
316 }
317
318 static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, umode_t mode)
319 {
320 int res;
321
322 mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
323 res = usbfs_mknod (dir, dentry, mode, 0);
324 if (!res)
325 inc_nlink(dir);
326 return res;
327 }
328
329 static int usbfs_create (struct inode *dir, struct dentry *dentry, umode_t mode)
330 {
331 mode = (mode & S_IALLUGO) | S_IFREG;
332 return usbfs_mknod (dir, dentry, mode, 0);
333 }
334
335 static inline int usbfs_positive (struct dentry *dentry)
336 {
337 return dentry->d_inode && !d_unhashed(dentry);
338 }
339
340 static int usbfs_empty (struct dentry *dentry)
341 {
342 struct list_head *list;
343
344 spin_lock(&dentry->d_lock);
345 list_for_each(list, &dentry->d_subdirs) {
346 struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
347
348 spin_lock_nested(&de->d_lock, DENTRY_D_LOCK_NESTED);
349 if (usbfs_positive(de)) {
350 spin_unlock(&de->d_lock);
351 spin_unlock(&dentry->d_lock);
352 return 0;
353 }
354 spin_unlock(&de->d_lock);
355 }
356 spin_unlock(&dentry->d_lock);
357 return 1;
358 }
359
360 static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
361 {
362 struct inode *inode = dentry->d_inode;
363 mutex_lock(&inode->i_mutex);
364 drop_nlink(dentry->d_inode);
365 dput(dentry);
366 mutex_unlock(&inode->i_mutex);
367 d_delete(dentry);
368 return 0;
369 }
370
371 static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
372 {
373 int error = -ENOTEMPTY;
374 struct inode * inode = dentry->d_inode;
375
376 mutex_lock(&inode->i_mutex);
377 dentry_unhash(dentry);
378 if (usbfs_empty(dentry)) {
379 dont_mount(dentry);
380 drop_nlink(dentry->d_inode);
381 drop_nlink(dentry->d_inode);
382 dput(dentry);
383 inode->i_flags |= S_DEAD;
384 drop_nlink(dir);
385 error = 0;
386 }
387 mutex_unlock(&inode->i_mutex);
388 if (!error)
389 d_delete(dentry);
390 return error;
391 }
392
393
394 /* default file operations */
395 static ssize_t default_read_file (struct file *file, char __user *buf,
396 size_t count, loff_t *ppos)
397 {
398 return 0;
399 }
400
401 static ssize_t default_write_file (struct file *file, const char __user *buf,
402 size_t count, loff_t *ppos)
403 {
404 return count;
405 }
406
407 static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
408 {
409 loff_t retval = -EINVAL;
410
411 mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
412 switch(orig) {
413 case 0:
414 if (offset > 0) {
415 file->f_pos = offset;
416 retval = file->f_pos;
417 }
418 break;
419 case 1:
420 if ((offset + file->f_pos) > 0) {
421 file->f_pos += offset;
422 retval = file->f_pos;
423 }
424 break;
425 default:
426 break;
427 }
428 mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
429 return retval;
430 }
431
432 static int default_open (struct inode *inode, struct file *file)
433 {
434 if (inode->i_private)
435 file->private_data = inode->i_private;
436
437 return 0;
438 }
439
440 static const struct file_operations default_file_operations = {
441 .read = default_read_file,
442 .write = default_write_file,
443 .open = default_open,
444 .llseek = default_file_lseek,
445 };
446
447 static const struct super_operations usbfs_ops = {
448 .statfs = simple_statfs,
449 .drop_inode = generic_delete_inode,
450 .remount_fs = remount,
451 .show_options = usbfs_show_options,
452 };
453
454 static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
455 {
456 struct inode *inode;
457 struct dentry *root;
458
459 sb->s_blocksize = PAGE_CACHE_SIZE;
460 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
461 sb->s_magic = USBDEVICE_SUPER_MAGIC;
462 sb->s_op = &usbfs_ops;
463 sb->s_time_gran = 1;
464 inode = usbfs_get_inode(sb, S_IFDIR | 0755, 0);
465
466 if (!inode) {
467 dbg("%s: could not get inode!",__func__);
468 return -ENOMEM;
469 }
470
471 root = d_alloc_root(inode);
472 if (!root) {
473 dbg("%s: could not get root dentry!",__func__);
474 iput(inode);
475 return -ENOMEM;
476 }
477 sb->s_root = root;
478 return 0;
479 }
480
481 /*
482 * fs_create_by_name - create a file, given a name
483 * @name: name of file
484 * @mode: type of file
485 * @parent: dentry of directory to create it in
486 * @dentry: resulting dentry of file
487 *
488 * This function handles both regular files and directories.
489 */
490 static int fs_create_by_name (const char *name, umode_t mode,
491 struct dentry *parent, struct dentry **dentry)
492 {
493 int error = 0;
494
495 /* If the parent is not specified, we create it in the root.
496 * We need the root dentry to do this, which is in the super
497 * block. A pointer to that is in the struct vfsmount that we
498 * have around.
499 */
500 if (!parent ) {
501 if (usbfs_mount)
502 parent = usbfs_mount->mnt_root;
503 }
504
505 if (!parent) {
506 dbg("Ah! can not find a parent!");
507 return -EFAULT;
508 }
509
510 *dentry = NULL;
511 mutex_lock(&parent->d_inode->i_mutex);
512 *dentry = lookup_one_len(name, parent, strlen(name));
513 if (!IS_ERR(*dentry)) {
514 if (S_ISDIR(mode))
515 error = usbfs_mkdir (parent->d_inode, *dentry, mode);
516 else
517 error = usbfs_create (parent->d_inode, *dentry, mode);
518 } else
519 error = PTR_ERR(*dentry);
520 mutex_unlock(&parent->d_inode->i_mutex);
521
522 return error;
523 }
524
525 static struct dentry *fs_create_file (const char *name, umode_t mode,
526 struct dentry *parent, void *data,
527 const struct file_operations *fops,
528 uid_t uid, gid_t gid)
529 {
530 struct dentry *dentry;
531 int error;
532
533 dbg("creating file '%s'",name);
534
535 error = fs_create_by_name (name, mode, parent, &dentry);
536 if (error) {
537 dentry = NULL;
538 } else {
539 if (dentry->d_inode) {
540 if (data)
541 dentry->d_inode->i_private = data;
542 if (fops)
543 dentry->d_inode->i_fop = fops;
544 dentry->d_inode->i_uid = uid;
545 dentry->d_inode->i_gid = gid;
546 }
547 }
548
549 return dentry;
550 }
551
552 static void fs_remove_file (struct dentry *dentry)
553 {
554 struct dentry *parent = dentry->d_parent;
555
556 if (!parent || !parent->d_inode)
557 return;
558
559 mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_PARENT);
560 if (usbfs_positive(dentry)) {
561 if (dentry->d_inode) {
562 if (S_ISDIR(dentry->d_inode->i_mode))
563 usbfs_rmdir(parent->d_inode, dentry);
564 else
565 usbfs_unlink(parent->d_inode, dentry);
566 dput(dentry);
567 }
568 }
569 mutex_unlock(&parent->d_inode->i_mutex);
570 }
571
572 /* --------------------------------------------------------------------- */
573
574 static struct dentry *usb_mount(struct file_system_type *fs_type,
575 int flags, const char *dev_name, void *data)
576 {
577 return mount_single(fs_type, flags, data, usbfs_fill_super);
578 }
579
580 static struct file_system_type usb_fs_type = {
581 .owner = THIS_MODULE,
582 .name = "usbfs",
583 .mount = usb_mount,
584 .kill_sb = kill_litter_super,
585 };
586
587 /* --------------------------------------------------------------------- */
588
589 static int create_special_files (void)
590 {
591 struct dentry *parent;
592 int retval;
593
594 /* the simple_pin_fs calls will call remount with no options
595 * without this flag that would overwrite the real mount options (if any)
596 */
597 ignore_mount = 1;
598
599 /* create the devices special file */
600 retval = simple_pin_fs(&usb_fs_type, &usbfs_mount, &usbfs_mount_count);
601 if (retval) {
602 printk(KERN_ERR "Unable to get usbfs mount\n");
603 goto exit;
604 }
605
606 ignore_mount = 0;
607
608 parent = usbfs_mount->mnt_root;
609 devices_usbfs_dentry = fs_create_file ("devices",
610 listmode | S_IFREG, parent,
611 NULL, &usbfs_devices_fops,
612 listuid, listgid);
613 if (devices_usbfs_dentry == NULL) {
614 printk(KERN_ERR "Unable to create devices usbfs file\n");
615 retval = -ENODEV;
616 goto error_clean_mounts;
617 }
618
619 goto exit;
620
621 error_clean_mounts:
622 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
623 exit:
624 return retval;
625 }
626
627 static void remove_special_files (void)
628 {
629 if (devices_usbfs_dentry)
630 fs_remove_file (devices_usbfs_dentry);
631 devices_usbfs_dentry = NULL;
632 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
633 }
634
635 void usbfs_update_special (void)
636 {
637 struct inode *inode;
638
639 if (devices_usbfs_dentry) {
640 inode = devices_usbfs_dentry->d_inode;
641 if (inode)
642 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
643 }
644 }
645
646 static void usbfs_add_bus(struct usb_bus *bus)
647 {
648 struct dentry *parent;
649 char name[8];
650 int retval;
651
652 /* create the special files if this is the first bus added */
653 if (num_buses == 0) {
654 retval = create_special_files();
655 if (retval)
656 return;
657 }
658 ++num_buses;
659
660 sprintf (name, "%03d", bus->busnum);
661
662 parent = usbfs_mount->mnt_root;
663 bus->usbfs_dentry = fs_create_file (name, busmode | S_IFDIR, parent,
664 bus, NULL, busuid, busgid);
665 if (bus->usbfs_dentry == NULL) {
666 printk(KERN_ERR "Error creating usbfs bus entry\n");
667 return;
668 }
669 }
670
671 static void usbfs_remove_bus(struct usb_bus *bus)
672 {
673 if (bus->usbfs_dentry) {
674 fs_remove_file (bus->usbfs_dentry);
675 bus->usbfs_dentry = NULL;
676 }
677
678 --num_buses;
679 if (num_buses <= 0) {
680 remove_special_files();
681 num_buses = 0;
682 }
683 }
684
685 static void usbfs_add_device(struct usb_device *dev)
686 {
687 char name[8];
688 int i;
689 int i_size;
690
691 sprintf (name, "%03d", dev->devnum);
692 dev->usbfs_dentry = fs_create_file (name, devmode | S_IFREG,
693 dev->bus->usbfs_dentry, dev,
694 &usbdev_file_operations,
695 devuid, devgid);
696 if (dev->usbfs_dentry == NULL) {
697 printk(KERN_ERR "Error creating usbfs device entry\n");
698 return;
699 }
700
701 /* Set the size of the device's file to be
702 * equal to the size of the device descriptors. */
703 i_size = sizeof (struct usb_device_descriptor);
704 for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
705 struct usb_config_descriptor *config =
706 (struct usb_config_descriptor *)dev->rawdescriptors[i];
707 i_size += le16_to_cpu(config->wTotalLength);
708 }
709 if (dev->usbfs_dentry->d_inode)
710 dev->usbfs_dentry->d_inode->i_size = i_size;
711 }
712
713 static void usbfs_remove_device(struct usb_device *dev)
714 {
715 if (dev->usbfs_dentry) {
716 fs_remove_file (dev->usbfs_dentry);
717 dev->usbfs_dentry = NULL;
718 }
719 }
720
721 static int usbfs_notify(struct notifier_block *self, unsigned long action, void *dev)
722 {
723 switch (action) {
724 case USB_DEVICE_ADD:
725 usbfs_add_device(dev);
726 break;
727 case USB_DEVICE_REMOVE:
728 usbfs_remove_device(dev);
729 break;
730 case USB_BUS_ADD:
731 usbfs_add_bus(dev);
732 break;
733 case USB_BUS_REMOVE:
734 usbfs_remove_bus(dev);
735 }
736
737 usbfs_update_special();
738 usbfs_conn_disc_event();
739 return NOTIFY_OK;
740 }
741
742 static struct notifier_block usbfs_nb = {
743 .notifier_call = usbfs_notify,
744 };
745
746 /* --------------------------------------------------------------------- */
747
748 static struct proc_dir_entry *usbdir = NULL;
749
750 int __init usbfs_init(void)
751 {
752 int retval;
753
754 retval = register_filesystem(&usb_fs_type);
755 if (retval)
756 return retval;
757
758 usb_register_notify(&usbfs_nb);
759
760 /* create mount point for usbfs */
761 usbdir = proc_mkdir("bus/usb", NULL);
762
763 return 0;
764 }
765
766 void usbfs_cleanup(void)
767 {
768 usb_unregister_notify(&usbfs_nb);
769 unregister_filesystem(&usb_fs_type);
770 if (usbdir)
771 remove_proc_entry("bus/usb", NULL);
772 }
773