1 /*****************************************************************************/
4 * inode.c -- Inode/Dentry functions for the USB device file system.
6 * Copyright (C) 2000 Thomas Sailer (sailer@ife.ee.ethz.ch)
7 * Copyright (C) 2001,2002,2004 Greg Kroah-Hartman (greg@kroah.com)
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.
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.
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.
24 * 0.1 04.01.2000 Created
25 * 0.2 10.12.2001 converted to use the vfs layer better
28 /*****************************************************************************/
30 #include <linux/module.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 <asm/byteorder.h>
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
50 static struct super_operations usbfs_ops
;
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;
56 static struct dentry
*devices_usbfs_dentry
;
57 static int num_buses
; /* = 0 */
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
;
69 static int usbfs_show_options(struct seq_file
*seq
, struct vfsmount
*mnt
)
72 seq_printf(seq
, ",devuid=%u", devuid
);
74 seq_printf(seq
, ",devgid=%u", devgid
);
75 if (devmode
!= USBFS_DEFAULT_DEVMODE
)
76 seq_printf(seq
, ",devmode=%o", devmode
);
78 seq_printf(seq
, ",busuid=%u", busuid
);
80 seq_printf(seq
, ",busgid=%u", busgid
);
81 if (busmode
!= USBFS_DEFAULT_BUSMODE
)
82 seq_printf(seq
, ",busmode=%o", busmode
);
84 seq_printf(seq
, ",listuid=%u", listuid
);
86 seq_printf(seq
, ",listgid=%u", listgid
);
87 if (listmode
!= USBFS_DEFAULT_LISTMODE
)
88 seq_printf(seq
, ",listmode=%o", listmode
);
94 Opt_devuid
, Opt_devgid
, Opt_devmode
,
95 Opt_busuid
, Opt_busgid
, Opt_busmode
,
96 Opt_listuid
, Opt_listgid
, Opt_listmode
,
100 static 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"},
113 static int parse_options(struct super_block
*s
, char *data
)
118 /* (re)set to defaults. */
125 devmode
= USBFS_DEFAULT_DEVMODE
;
126 busmode
= USBFS_DEFAULT_BUSMODE
;
127 listmode
= USBFS_DEFAULT_LISTMODE
;
129 while ((p
= strsep(&data
, ",")) != NULL
) {
130 substring_t args
[MAX_OPT_ARGS
];
135 token
= match_token(p
, tokens
, args
);
138 if (match_int(&args
[0], &option
))
143 if (match_int(&args
[0], &option
))
148 if (match_octal(&args
[0], &option
))
150 devmode
= option
& S_IRWXUGO
;
153 if (match_int(&args
[0], &option
))
158 if (match_int(&args
[0], &option
))
163 if (match_octal(&args
[0], &option
))
165 busmode
= option
& S_IRWXUGO
;
168 if (match_int(&args
[0], &option
))
173 if (match_int(&args
[0], &option
))
178 if (match_octal(&args
[0], &option
))
180 listmode
= option
& S_IRWXUGO
;
183 err("usbfs: unrecognised mount option \"%s\" "
184 "or missing value\n", p
);
192 static void update_special(struct dentry
*special
)
194 special
->d_inode
->i_uid
= listuid
;
195 special
->d_inode
->i_gid
= listgid
;
196 special
->d_inode
->i_mode
= S_IFREG
| listmode
;
199 static void update_dev(struct dentry
*dev
)
201 dev
->d_inode
->i_uid
= devuid
;
202 dev
->d_inode
->i_gid
= devgid
;
203 dev
->d_inode
->i_mode
= S_IFREG
| devmode
;
206 static void update_bus(struct dentry
*bus
)
208 struct dentry
*dev
= NULL
;
210 bus
->d_inode
->i_uid
= busuid
;
211 bus
->d_inode
->i_gid
= busgid
;
212 bus
->d_inode
->i_mode
= S_IFDIR
| busmode
;
214 mutex_lock(&bus
->d_inode
->i_mutex
);
216 list_for_each_entry(dev
, &bus
->d_subdirs
, d_u
.d_child
)
220 mutex_unlock(&bus
->d_inode
->i_mutex
);
223 static void update_sb(struct super_block
*sb
)
225 struct dentry
*root
= sb
->s_root
;
226 struct dentry
*bus
= NULL
;
231 mutex_lock_nested(&root
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
233 list_for_each_entry(bus
, &root
->d_subdirs
, d_u
.d_child
) {
235 switch (S_IFMT
& bus
->d_inode
->i_mode
) {
243 warn("Unknown node %s mode %x found on remount!\n",bus
->d_name
.name
,bus
->d_inode
->i_mode
);
249 mutex_unlock(&root
->d_inode
->i_mutex
);
252 static int remount(struct super_block
*sb
, int *flags
, char *data
)
254 /* If this is not a real mount,
255 * i.e. it's a simple_pin_fs from create_special_files,
261 if (parse_options(sb
, data
)) {
262 warn("usbfs: mount parameter error:");
266 if (usbfs_mount
&& usbfs_mount
->mnt_sb
)
267 update_sb(usbfs_mount
->mnt_sb
);
272 static struct inode
*usbfs_get_inode (struct super_block
*sb
, int mode
, dev_t dev
)
274 struct inode
*inode
= new_inode(sb
);
277 inode
->i_mode
= mode
;
278 inode
->i_uid
= current
->fsuid
;
279 inode
->i_gid
= current
->fsgid
;
281 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
282 switch (mode
& S_IFMT
) {
284 init_special_inode(inode
, mode
, dev
);
287 inode
->i_fop
= &default_file_operations
;
290 inode
->i_op
= &simple_dir_inode_operations
;
291 inode
->i_fop
= &simple_dir_operations
;
293 /* directory inodes start off with i_nlink == 2 (for "." entry) */
302 static int usbfs_mknod (struct inode
*dir
, struct dentry
*dentry
, int mode
,
305 struct inode
*inode
= usbfs_get_inode(dir
->i_sb
, mode
, dev
);
312 d_instantiate(dentry
, inode
);
319 static int usbfs_mkdir (struct inode
*dir
, struct dentry
*dentry
, int mode
)
323 mode
= (mode
& (S_IRWXUGO
| S_ISVTX
)) | S_IFDIR
;
324 res
= usbfs_mknod (dir
, dentry
, mode
, 0);
330 static int usbfs_create (struct inode
*dir
, struct dentry
*dentry
, int mode
)
332 mode
= (mode
& S_IALLUGO
) | S_IFREG
;
333 return usbfs_mknod (dir
, dentry
, mode
, 0);
336 static inline int usbfs_positive (struct dentry
*dentry
)
338 return dentry
->d_inode
&& !d_unhashed(dentry
);
341 static int usbfs_empty (struct dentry
*dentry
)
343 struct list_head
*list
;
345 spin_lock(&dcache_lock
);
347 list_for_each(list
, &dentry
->d_subdirs
) {
348 struct dentry
*de
= list_entry(list
, struct dentry
, d_u
.d_child
);
349 if (usbfs_positive(de
)) {
350 spin_unlock(&dcache_lock
);
355 spin_unlock(&dcache_lock
);
359 static int usbfs_unlink (struct inode
*dir
, struct dentry
*dentry
)
361 struct inode
*inode
= dentry
->d_inode
;
362 mutex_lock(&inode
->i_mutex
);
363 drop_nlink(dentry
->d_inode
);
365 mutex_unlock(&inode
->i_mutex
);
370 static int usbfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
372 int error
= -ENOTEMPTY
;
373 struct inode
* inode
= dentry
->d_inode
;
375 mutex_lock(&inode
->i_mutex
);
376 dentry_unhash(dentry
);
377 if (usbfs_empty(dentry
)) {
378 drop_nlink(dentry
->d_inode
);
379 drop_nlink(dentry
->d_inode
);
381 inode
->i_flags
|= S_DEAD
;
385 mutex_unlock(&inode
->i_mutex
);
393 /* default file operations */
394 static ssize_t
default_read_file (struct file
*file
, char __user
*buf
,
395 size_t count
, loff_t
*ppos
)
400 static ssize_t
default_write_file (struct file
*file
, const char __user
*buf
,
401 size_t count
, loff_t
*ppos
)
406 static loff_t
default_file_lseek (struct file
*file
, loff_t offset
, int orig
)
408 loff_t retval
= -EINVAL
;
410 mutex_lock(&file
->f_path
.dentry
->d_inode
->i_mutex
);
414 file
->f_pos
= offset
;
415 retval
= file
->f_pos
;
419 if ((offset
+ file
->f_pos
) > 0) {
420 file
->f_pos
+= offset
;
421 retval
= file
->f_pos
;
427 mutex_unlock(&file
->f_path
.dentry
->d_inode
->i_mutex
);
431 static int default_open (struct inode
*inode
, struct file
*file
)
433 if (inode
->i_private
)
434 file
->private_data
= inode
->i_private
;
439 static const struct file_operations default_file_operations
= {
440 .read
= default_read_file
,
441 .write
= default_write_file
,
442 .open
= default_open
,
443 .llseek
= default_file_lseek
,
446 static struct super_operations usbfs_ops
= {
447 .statfs
= simple_statfs
,
448 .drop_inode
= generic_delete_inode
,
449 .remount_fs
= remount
,
450 .show_options
= usbfs_show_options
,
453 static int usbfs_fill_super(struct super_block
*sb
, void *data
, int silent
)
458 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
459 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
460 sb
->s_magic
= USBDEVICE_SUPER_MAGIC
;
461 sb
->s_op
= &usbfs_ops
;
463 inode
= usbfs_get_inode(sb
, S_IFDIR
| 0755, 0);
466 dbg("%s: could not get inode!",__FUNCTION__
);
470 root
= d_alloc_root(inode
);
472 dbg("%s: could not get root dentry!",__FUNCTION__
);
481 * fs_create_by_name - create a file, given a name
482 * @name: name of file
483 * @mode: type of file
484 * @parent: dentry of directory to create it in
485 * @dentry: resulting dentry of file
487 * This function handles both regular files and directories.
489 static int fs_create_by_name (const char *name
, mode_t mode
,
490 struct dentry
*parent
, struct dentry
**dentry
)
494 /* If the parent is not specified, we create it in the root.
495 * We need the root dentry to do this, which is in the super
496 * block. A pointer to that is in the struct vfsmount that we
500 if (usbfs_mount
&& usbfs_mount
->mnt_sb
) {
501 parent
= usbfs_mount
->mnt_sb
->s_root
;
506 dbg("Ah! can not find a parent!");
511 mutex_lock(&parent
->d_inode
->i_mutex
);
512 *dentry
= lookup_one_len(name
, parent
, strlen(name
));
513 if (!IS_ERR(dentry
)) {
514 if ((mode
& S_IFMT
) == S_IFDIR
)
515 error
= usbfs_mkdir (parent
->d_inode
, *dentry
, mode
);
517 error
= usbfs_create (parent
->d_inode
, *dentry
, mode
);
519 error
= PTR_ERR(dentry
);
520 mutex_unlock(&parent
->d_inode
->i_mutex
);
525 static struct dentry
*fs_create_file (const char *name
, mode_t mode
,
526 struct dentry
*parent
, void *data
,
527 const struct file_operations
*fops
,
528 uid_t uid
, gid_t gid
)
530 struct dentry
*dentry
;
533 dbg("creating file '%s'",name
);
535 error
= fs_create_by_name (name
, mode
, parent
, &dentry
);
539 if (dentry
->d_inode
) {
541 dentry
->d_inode
->i_private
= data
;
543 dentry
->d_inode
->i_fop
= fops
;
544 dentry
->d_inode
->i_uid
= uid
;
545 dentry
->d_inode
->i_gid
= gid
;
552 static void fs_remove_file (struct dentry
*dentry
)
554 struct dentry
*parent
= dentry
->d_parent
;
556 if (!parent
|| !parent
->d_inode
)
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
);
565 usbfs_unlink(parent
->d_inode
, dentry
);
569 mutex_unlock(&parent
->d_inode
->i_mutex
);
572 /* --------------------------------------------------------------------- */
574 static int usb_get_sb(struct file_system_type
*fs_type
,
575 int flags
, const char *dev_name
, void *data
, struct vfsmount
*mnt
)
577 return get_sb_single(fs_type
, flags
, data
, usbfs_fill_super
, mnt
);
580 static struct file_system_type usb_fs_type
= {
581 .owner
= THIS_MODULE
,
583 .get_sb
= usb_get_sb
,
584 .kill_sb
= kill_litter_super
,
587 /* --------------------------------------------------------------------- */
589 static int create_special_files (void)
591 struct dentry
*parent
;
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)
599 /* create the devices special file */
600 retval
= simple_pin_fs(&usb_fs_type
, &usbfs_mount
, &usbfs_mount_count
);
602 err ("Unable to get usbfs mount");
608 parent
= usbfs_mount
->mnt_sb
->s_root
;
609 devices_usbfs_dentry
= fs_create_file ("devices",
610 listmode
| S_IFREG
, parent
,
611 NULL
, &usbfs_devices_fops
,
613 if (devices_usbfs_dentry
== NULL
) {
614 err ("Unable to create devices usbfs file");
616 goto error_clean_mounts
;
622 simple_release_fs(&usbfs_mount
, &usbfs_mount_count
);
627 static void remove_special_files (void)
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
);
635 void usbfs_update_special (void)
639 if (devices_usbfs_dentry
) {
640 inode
= devices_usbfs_dentry
->d_inode
;
642 inode
->i_atime
= inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
646 static void usbfs_add_bus(struct usb_bus
*bus
)
648 struct dentry
*parent
;
652 /* create the special files if this is the first bus added */
653 if (num_buses
== 0) {
654 retval
= create_special_files();
660 sprintf (name
, "%03d", bus
->busnum
);
662 parent
= usbfs_mount
->mnt_sb
->s_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 err ("error creating usbfs bus entry");
671 static void usbfs_remove_bus(struct usb_bus
*bus
)
673 if (bus
->usbfs_dentry
) {
674 fs_remove_file (bus
->usbfs_dentry
);
675 bus
->usbfs_dentry
= NULL
;
679 if (num_buses
<= 0) {
680 remove_special_files();
685 static void usbfs_add_device(struct usb_device
*dev
)
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
,
696 if (dev
->usbfs_dentry
== NULL
) {
697 err ("error creating usbfs device entry");
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
);
709 if (dev
->usbfs_dentry
->d_inode
)
710 dev
->usbfs_dentry
->d_inode
->i_size
= i_size
;
713 static void usbfs_remove_device(struct usb_device
*dev
)
715 struct dev_state
*ds
;
716 struct siginfo sinfo
;
718 if (dev
->usbfs_dentry
) {
719 fs_remove_file (dev
->usbfs_dentry
);
720 dev
->usbfs_dentry
= NULL
;
722 while (!list_empty(&dev
->filelist
)) {
723 ds
= list_entry(dev
->filelist
.next
, struct dev_state
, list
);
724 wake_up_all(&ds
->wait
);
725 list_del_init(&ds
->list
);
727 sinfo
.si_signo
= ds
->discsignr
;
728 sinfo
.si_errno
= EPIPE
;
729 sinfo
.si_code
= SI_ASYNCIO
;
730 sinfo
.si_addr
= ds
->disccontext
;
731 kill_pid_info_as_uid(ds
->discsignr
, &sinfo
, ds
->disc_pid
, ds
->disc_uid
, ds
->disc_euid
, ds
->secid
);
736 static int usbfs_notify(struct notifier_block
*self
, unsigned long action
, void *dev
)
740 usbfs_add_device(dev
);
742 case USB_DEVICE_REMOVE
:
743 usbfs_remove_device(dev
);
749 usbfs_remove_bus(dev
);
752 usbfs_update_special();
753 usbfs_conn_disc_event();
757 static struct notifier_block usbfs_nb
= {
758 .notifier_call
= usbfs_notify
,
761 /* --------------------------------------------------------------------- */
763 static struct proc_dir_entry
*usbdir
= NULL
;
765 int __init
usbfs_init(void)
769 retval
= register_filesystem(&usb_fs_type
);
773 usb_register_notify(&usbfs_nb
);
775 /* create mount point for usbfs */
776 usbdir
= proc_mkdir("usb", proc_bus
);
781 void usbfs_cleanup(void)
783 usb_unregister_notify(&usbfs_nb
);
784 unregister_filesystem(&usb_fs_type
);
786 remove_proc_entry("usb", proc_bus
);