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Linux-2.6.12-rc2
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / usb / core / inode.c
blobd913407bcdc1e3e453d6811b9a1547234386badb
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/config.h>
31 #include <linux/module.h>
32 #include <linux/fs.h>
33 #include <linux/mount.h>
34 #include <linux/pagemap.h>
35 #include <linux/init.h>
36 #include <linux/proc_fs.h>
37 #include <linux/usb.h>
38 #include <linux/namei.h>
39 #include <linux/usbdevice_fs.h>
40 #include <linux/smp_lock.h>
41 #include <linux/parser.h>
42 #include <asm/byteorder.h>
43 #include "usb.h"
44
45 static struct super_operations usbfs_ops;
46 static struct file_operations default_file_operations;
47 static struct inode_operations usbfs_dir_inode_operations;
48 static struct vfsmount *usbfs_mount;
49 static int usbfs_mount_count; /* = 0 */
50 static int ignore_mount = 0;
51
52 static struct dentry *devices_usbfs_dentry;
53 static int num_buses; /* = 0 */
54
55 static uid_t devuid; /* = 0 */
56 static uid_t busuid; /* = 0 */
57 static uid_t listuid; /* = 0 */
58 static gid_t devgid; /* = 0 */
59 static gid_t busgid; /* = 0 */
60 static gid_t listgid; /* = 0 */
61 static umode_t devmode = S_IWUSR | S_IRUGO;
62 static umode_t busmode = S_IXUGO | S_IRUGO;
63 static umode_t listmode = S_IRUGO;
64
65 enum {
66 Opt_devuid, Opt_devgid, Opt_devmode,
67 Opt_busuid, Opt_busgid, Opt_busmode,
68 Opt_listuid, Opt_listgid, Opt_listmode,
69 Opt_err,
70 };
71
72 static match_table_t tokens = {
73 {Opt_devuid, "devuid=%u"},
74 {Opt_devgid, "devgid=%u"},
75 {Opt_devmode, "devmode=%o"},
76 {Opt_busuid, "busuid=%u"},
77 {Opt_busgid, "busgid=%u"},
78 {Opt_busmode, "busmode=%o"},
79 {Opt_listuid, "listuid=%u"},
80 {Opt_listgid, "listgid=%u"},
81 {Opt_listmode, "listmode=%o"},
82 {Opt_err, NULL}
83 };
84
85 static int parse_options(struct super_block *s, char *data)
86 {
87 char *p;
88 int option;
89
90 /* (re)set to defaults. */
91 devuid = 0;
92 busuid = 0;
93 listuid = 0;
94 devgid = 0;
95 busgid = 0;
96 listgid = 0;
97 devmode = S_IWUSR | S_IRUGO;
98 busmode = S_IXUGO | S_IRUGO;
99 listmode = S_IRUGO;
100
101 while ((p = strsep(&data, ",")) != NULL) {
102 substring_t args[MAX_OPT_ARGS];
103 int token;
104 if (!*p)
105 continue;
106
107 token = match_token(p, tokens, args);
108 switch (token) {
109 case Opt_devuid:
110 if (match_int(&args[0], &option))
111 return -EINVAL;
112 devuid = option;
113 break;
114 case Opt_devgid:
115 if (match_int(&args[0], &option))
116 return -EINVAL;
117 devgid = option;
118 break;
119 case Opt_devmode:
120 if (match_octal(&args[0], &option))
121 return -EINVAL;
122 devmode = option & S_IRWXUGO;
123 break;
124 case Opt_busuid:
125 if (match_int(&args[0], &option))
126 return -EINVAL;
127 busuid = option;
128 break;
129 case Opt_busgid:
130 if (match_int(&args[0], &option))
131 return -EINVAL;
132 busgid = option;
133 break;
134 case Opt_busmode:
135 if (match_octal(&args[0], &option))
136 return -EINVAL;
137 busmode = option & S_IRWXUGO;
138 break;
139 case Opt_listuid:
140 if (match_int(&args[0], &option))
141 return -EINVAL;
142 listuid = option;
143 break;
144 case Opt_listgid:
145 if (match_int(&args[0], &option))
146 return -EINVAL;
147 listgid = option;
148 break;
149 case Opt_listmode:
150 if (match_octal(&args[0], &option))
151 return -EINVAL;
152 listmode = option & S_IRWXUGO;
153 break;
154 default:
155 err("usbfs: unrecognised mount option \"%s\" "
156 "or missing value\n", p);
157 return -EINVAL;
158 }
159 }
160
161 return 0;
162 }
163
164 static void update_special(struct dentry *special)
165 {
166 special->d_inode->i_uid = listuid;
167 special->d_inode->i_gid = listgid;
168 special->d_inode->i_mode = S_IFREG | listmode;
169 }
170
171 static void update_dev(struct dentry *dev)
172 {
173 dev->d_inode->i_uid = devuid;
174 dev->d_inode->i_gid = devgid;
175 dev->d_inode->i_mode = S_IFREG | devmode;
176 }
177
178 static void update_bus(struct dentry *bus)
179 {
180 struct dentry *dev = NULL;
181
182 bus->d_inode->i_uid = busuid;
183 bus->d_inode->i_gid = busgid;
184 bus->d_inode->i_mode = S_IFDIR | busmode;
185
186 down(&bus->d_inode->i_sem);
187
188 list_for_each_entry(dev, &bus->d_subdirs, d_child)
189 if (dev->d_inode)
190 update_dev(dev);
191
192 up(&bus->d_inode->i_sem);
193 }
194
195 static void update_sb(struct super_block *sb)
196 {
197 struct dentry *root = sb->s_root;
198 struct dentry *bus = NULL;
199
200 if (!root)
201 return;
202
203 down(&root->d_inode->i_sem);
204
205 list_for_each_entry(bus, &root->d_subdirs, d_child) {
206 if (bus->d_inode) {
207 switch (S_IFMT & bus->d_inode->i_mode) {
208 case S_IFDIR:
209 update_bus(bus);
210 break;
211 case S_IFREG:
212 update_special(bus);
213 break;
214 default:
215 warn("Unknown node %s mode %x found on remount!\n",bus->d_name.name,bus->d_inode->i_mode);
216 break;
217 }
218 }
219 }
220
221 up(&root->d_inode->i_sem);
222 }
223
224 static int remount(struct super_block *sb, int *flags, char *data)
225 {
226 /* If this is not a real mount,
227 * i.e. it's a simple_pin_fs from create_special_files,
228 * then ignore it.
229 */
230 if (ignore_mount)
231 return 0;
232
233 if (parse_options(sb, data)) {
234 warn("usbfs: mount parameter error:");
235 return -EINVAL;
236 }
237
238 if (usbfs_mount && usbfs_mount->mnt_sb)
239 update_sb(usbfs_mount->mnt_sb);
240
241 return 0;
242 }
243
244 static struct inode *usbfs_get_inode (struct super_block *sb, int mode, dev_t dev)
245 {
246 struct inode *inode = new_inode(sb);
247
248 if (inode) {
249 inode->i_mode = mode;
250 inode->i_uid = current->fsuid;
251 inode->i_gid = current->fsgid;
252 inode->i_blksize = PAGE_CACHE_SIZE;
253 inode->i_blocks = 0;
254 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
255 switch (mode & S_IFMT) {
256 default:
257 init_special_inode(inode, mode, dev);
258 break;
259 case S_IFREG:
260 inode->i_fop = &default_file_operations;
261 break;
262 case S_IFDIR:
263 inode->i_op = &usbfs_dir_inode_operations;
264 inode->i_fop = &simple_dir_operations;
265
266 /* directory inodes start off with i_nlink == 2 (for "." entry) */
267 inode->i_nlink++;
268 break;
269 }
270 }
271 return inode;
272 }
273
274 /* SMP-safe */
275 static int usbfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
276 dev_t dev)
277 {
278 struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
279 int error = -EPERM;
280
281 if (dentry->d_inode)
282 return -EEXIST;
283
284 if (inode) {
285 d_instantiate(dentry, inode);
286 dget(dentry);
287 error = 0;
288 }
289 return error;
290 }
291
292 static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
293 {
294 int res;
295
296 mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
297 res = usbfs_mknod (dir, dentry, mode, 0);
298 if (!res)
299 dir->i_nlink++;
300 return res;
301 }
302
303 static int usbfs_create (struct inode *dir, struct dentry *dentry, int mode)
304 {
305 mode = (mode & S_IALLUGO) | S_IFREG;
306 return usbfs_mknod (dir, dentry, mode, 0);
307 }
308
309 static inline int usbfs_positive (struct dentry *dentry)
310 {
311 return dentry->d_inode && !d_unhashed(dentry);
312 }
313
314 static int usbfs_empty (struct dentry *dentry)
315 {
316 struct list_head *list;
317
318 spin_lock(&dcache_lock);
319
320 list_for_each(list, &dentry->d_subdirs) {
321 struct dentry *de = list_entry(list, struct dentry, d_child);
322 if (usbfs_positive(de)) {
323 spin_unlock(&dcache_lock);
324 return 0;
325 }
326 }
327
328 spin_unlock(&dcache_lock);
329 return 1;
330 }
331
332 static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
333 {
334 struct inode *inode = dentry->d_inode;
335 down(&inode->i_sem);
336 dentry->d_inode->i_nlink--;
337 dput(dentry);
338 up(&inode->i_sem);
339 d_delete(dentry);
340 return 0;
341 }
342
343 static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
344 {
345 int error = -ENOTEMPTY;
346 struct inode * inode = dentry->d_inode;
347
348 down(&inode->i_sem);
349 dentry_unhash(dentry);
350 if (usbfs_empty(dentry)) {
351 dentry->d_inode->i_nlink -= 2;
352 dput(dentry);
353 inode->i_flags |= S_DEAD;
354 dir->i_nlink--;
355 error = 0;
356 }
357 up(&inode->i_sem);
358 if (!error)
359 d_delete(dentry);
360 dput(dentry);
361 return error;
362 }
363
364
365 /* default file operations */
366 static ssize_t default_read_file (struct file *file, char __user *buf,
367 size_t count, loff_t *ppos)
368 {
369 return 0;
370 }
371
372 static ssize_t default_write_file (struct file *file, const char __user *buf,
373 size_t count, loff_t *ppos)
374 {
375 return count;
376 }
377
378 static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
379 {
380 loff_t retval = -EINVAL;
381
382 down(&file->f_dentry->d_inode->i_sem);
383 switch(orig) {
384 case 0:
385 if (offset > 0) {
386 file->f_pos = offset;
387 retval = file->f_pos;
388 }
389 break;
390 case 1:
391 if ((offset + file->f_pos) > 0) {
392 file->f_pos += offset;
393 retval = file->f_pos;
394 }
395 break;
396 default:
397 break;
398 }
399 up(&file->f_dentry->d_inode->i_sem);
400 return retval;
401 }
402
403 static int default_open (struct inode *inode, struct file *file)
404 {
405 if (inode->u.generic_ip)
406 file->private_data = inode->u.generic_ip;
407
408 return 0;
409 }
410
411 static struct file_operations default_file_operations = {
412 .read = default_read_file,
413 .write = default_write_file,
414 .open = default_open,
415 .llseek = default_file_lseek,
416 };
417
418 static struct inode_operations usbfs_dir_inode_operations = {
419 .lookup = simple_lookup,
420 };
421
422 static struct super_operations usbfs_ops = {
423 .statfs = simple_statfs,
424 .drop_inode = generic_delete_inode,
425 .remount_fs = remount,
426 };
427
428 static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
429 {
430 struct inode *inode;
431 struct dentry *root;
432
433 sb->s_blocksize = PAGE_CACHE_SIZE;
434 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
435 sb->s_magic = USBDEVICE_SUPER_MAGIC;
436 sb->s_op = &usbfs_ops;
437 sb->s_time_gran = 1;
438 inode = usbfs_get_inode(sb, S_IFDIR | 0755, 0);
439
440 if (!inode) {
441 dbg("%s: could not get inode!",__FUNCTION__);
442 return -ENOMEM;
443 }
444
445 root = d_alloc_root(inode);
446 if (!root) {
447 dbg("%s: could not get root dentry!",__FUNCTION__);
448 iput(inode);
449 return -ENOMEM;
450 }
451 sb->s_root = root;
452 return 0;
453 }
454
455 static struct dentry * get_dentry(struct dentry *parent, const char *name)
456 {
457 struct qstr qstr;
458
459 qstr.name = name;
460 qstr.len = strlen(name);
461 qstr.hash = full_name_hash(name,qstr.len);
462 return lookup_hash(&qstr,parent);
463 }
464
465
466 /*
467 * fs_create_by_name - create a file, given a name
468 * @name: name of file
469 * @mode: type of file
470 * @parent: dentry of directory to create it in
471 * @dentry: resulting dentry of file
472 *
473 * This function handles both regular files and directories.
474 */
475 static int fs_create_by_name (const char *name, mode_t mode,
476 struct dentry *parent, struct dentry **dentry)
477 {
478 int error = 0;
479
480 /* If the parent is not specified, we create it in the root.
481 * We need the root dentry to do this, which is in the super
482 * block. A pointer to that is in the struct vfsmount that we
483 * have around.
484 */
485 if (!parent ) {
486 if (usbfs_mount && usbfs_mount->mnt_sb) {
487 parent = usbfs_mount->mnt_sb->s_root;
488 }
489 }
490
491 if (!parent) {
492 dbg("Ah! can not find a parent!");
493 return -EFAULT;
494 }
495
496 *dentry = NULL;
497 down(&parent->d_inode->i_sem);
498 *dentry = get_dentry (parent, name);
499 if (!IS_ERR(dentry)) {
500 if ((mode & S_IFMT) == S_IFDIR)
501 error = usbfs_mkdir (parent->d_inode, *dentry, mode);
502 else
503 error = usbfs_create (parent->d_inode, *dentry, mode);
504 } else
505 error = PTR_ERR(dentry);
506 up(&parent->d_inode->i_sem);
507
508 return error;
509 }
510
511 static struct dentry *fs_create_file (const char *name, mode_t mode,
512 struct dentry *parent, void *data,
513 struct file_operations *fops,
514 uid_t uid, gid_t gid)
515 {
516 struct dentry *dentry;
517 int error;
518
519 dbg("creating file '%s'",name);
520
521 error = fs_create_by_name (name, mode, parent, &dentry);
522 if (error) {
523 dentry = NULL;
524 } else {
525 if (dentry->d_inode) {
526 if (data)
527 dentry->d_inode->u.generic_ip = data;
528 if (fops)
529 dentry->d_inode->i_fop = fops;
530 dentry->d_inode->i_uid = uid;
531 dentry->d_inode->i_gid = gid;
532 }
533 }
534
535 return dentry;
536 }
537
538 static void fs_remove_file (struct dentry *dentry)
539 {
540 struct dentry *parent = dentry->d_parent;
541
542 if (!parent || !parent->d_inode)
543 return;
544
545 down(&parent->d_inode->i_sem);
546 if (usbfs_positive(dentry)) {
547 if (dentry->d_inode) {
548 if (S_ISDIR(dentry->d_inode->i_mode))
549 usbfs_rmdir(parent->d_inode, dentry);
550 else
551 usbfs_unlink(parent->d_inode, dentry);
552 dput(dentry);
553 }
554 }
555 up(&parent->d_inode->i_sem);
556 }
557
558 /* --------------------------------------------------------------------- */
559
560 static struct super_block *usb_get_sb(struct file_system_type *fs_type,
561 int flags, const char *dev_name, void *data)
562 {
563 return get_sb_single(fs_type, flags, data, usbfs_fill_super);
564 }
565
566 static struct file_system_type usb_fs_type = {
567 .owner = THIS_MODULE,
568 .name = "usbfs",
569 .get_sb = usb_get_sb,
570 .kill_sb = kill_litter_super,
571 };
572
573 /* --------------------------------------------------------------------- */
574
575 static int create_special_files (void)
576 {
577 struct dentry *parent;
578 int retval;
579
580 /* the simple_pin_fs calls will call remount with no options
581 * without this flag that would overwrite the real mount options (if any)
582 */
583 ignore_mount = 1;
584
585 /* create the devices special file */
586 retval = simple_pin_fs("usbfs", &usbfs_mount, &usbfs_mount_count);
587 if (retval) {
588 err ("Unable to get usbfs mount");
589 goto exit;
590 }
591
592 ignore_mount = 0;
593
594 parent = usbfs_mount->mnt_sb->s_root;
595 devices_usbfs_dentry = fs_create_file ("devices",
596 listmode | S_IFREG, parent,
597 NULL, &usbfs_devices_fops,
598 listuid, listgid);
599 if (devices_usbfs_dentry == NULL) {
600 err ("Unable to create devices usbfs file");
601 retval = -ENODEV;
602 goto error_clean_mounts;
603 }
604
605 goto exit;
606
607 error_clean_mounts:
608 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
609 exit:
610 return retval;
611 }
612
613 static void remove_special_files (void)
614 {
615 if (devices_usbfs_dentry)
616 fs_remove_file (devices_usbfs_dentry);
617 devices_usbfs_dentry = NULL;
618 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
619 }
620
621 void usbfs_update_special (void)
622 {
623 struct inode *inode;
624
625 if (devices_usbfs_dentry) {
626 inode = devices_usbfs_dentry->d_inode;
627 if (inode)
628 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
629 }
630 }
631
632 void usbfs_add_bus(struct usb_bus *bus)
633 {
634 struct dentry *parent;
635 char name[8];
636 int retval;
637
638 /* create the special files if this is the first bus added */
639 if (num_buses == 0) {
640 retval = create_special_files();
641 if (retval)
642 return;
643 }
644 ++num_buses;
645
646 sprintf (name, "%03d", bus->busnum);
647
648 parent = usbfs_mount->mnt_sb->s_root;
649 bus->usbfs_dentry = fs_create_file (name, busmode | S_IFDIR, parent,
650 bus, NULL, busuid, busgid);
651 if (bus->usbfs_dentry == NULL) {
652 err ("error creating usbfs bus entry");
653 return;
654 }
655
656 usbfs_update_special();
657 usbfs_conn_disc_event();
658 }
659
660 void usbfs_remove_bus(struct usb_bus *bus)
661 {
662 if (bus->usbfs_dentry) {
663 fs_remove_file (bus->usbfs_dentry);
664 bus->usbfs_dentry = NULL;
665 }
666
667 --num_buses;
668 if (num_buses <= 0) {
669 remove_special_files();
670 num_buses = 0;
671 }
672
673 usbfs_update_special();
674 usbfs_conn_disc_event();
675 }
676
677 void usbfs_add_device(struct usb_device *dev)
678 {
679 char name[8];
680 int i;
681 int i_size;
682
683 sprintf (name, "%03d", dev->devnum);
684 dev->usbfs_dentry = fs_create_file (name, devmode | S_IFREG,
685 dev->bus->usbfs_dentry, dev,
686 &usbfs_device_file_operations,
687 devuid, devgid);
688 if (dev->usbfs_dentry == NULL) {
689 err ("error creating usbfs device entry");
690 return;
691 }
692
693 /* Set the size of the device's file to be
694 * equal to the size of the device descriptors. */
695 i_size = sizeof (struct usb_device_descriptor);
696 for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
697 struct usb_config_descriptor *config =
698 (struct usb_config_descriptor *)dev->rawdescriptors[i];
699 i_size += le16_to_cpu(config->wTotalLength);
700 }
701 if (dev->usbfs_dentry->d_inode)
702 dev->usbfs_dentry->d_inode->i_size = i_size;
703
704 usbfs_update_special();
705 usbfs_conn_disc_event();
706 }
707
708 void usbfs_remove_device(struct usb_device *dev)
709 {
710 struct dev_state *ds;
711 struct siginfo sinfo;
712
713 if (dev->usbfs_dentry) {
714 fs_remove_file (dev->usbfs_dentry);
715 dev->usbfs_dentry = NULL;
716 }
717 while (!list_empty(&dev->filelist)) {
718 ds = list_entry(dev->filelist.next, struct dev_state, list);
719 wake_up_all(&ds->wait);
720 list_del_init(&ds->list);
721 if (ds->discsignr) {
722 sinfo.si_signo = SIGPIPE;
723 sinfo.si_errno = EPIPE;
724 sinfo.si_code = SI_ASYNCIO;
725 sinfo.si_addr = ds->disccontext;
726 send_sig_info(ds->discsignr, &sinfo, ds->disctask);
727 }
728 }
729 usbfs_update_special();
730 usbfs_conn_disc_event();
731 }
732
733 /* --------------------------------------------------------------------- */
734
735 static struct proc_dir_entry *usbdir = NULL;
736
737 int __init usbfs_init(void)
738 {
739 int retval;
740
741 retval = usb_register(&usbfs_driver);
742 if (retval)
743 return retval;
744
745 retval = register_filesystem(&usb_fs_type);
746 if (retval) {
747 usb_deregister(&usbfs_driver);
748 return retval;
749 }
750
751 /* create mount point for usbfs */
752 usbdir = proc_mkdir("usb", proc_bus);
753
754 return 0;
755 }
756
757 void usbfs_cleanup(void)
758 {
759 usb_deregister(&usbfs_driver);
760 unregister_filesystem(&usb_fs_type);
761 if (usbdir)
762 remove_proc_entry("usb", proc_bus);
763 }
764
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