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/smp_lock.h>
40 #include <linux/parser.h>
41 #include <linux/notifier.h>
42 #include <asm/byteorder.h>
46 static struct super_operations usbfs_ops;
47 static const struct file_operations default_file_operations;
48 static struct vfsmount *usbfs_mount;
49 static int usbfs_mount_count; /* = 0 */
50 static int ignore_mount = 0;
52 static struct dentry *devices_usbfs_dentry;
53 static int num_buses; /* = 0 */
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;
66 Opt_devuid, Opt_devgid, Opt_devmode,
67 Opt_busuid, Opt_busgid, Opt_busmode,
68 Opt_listuid, Opt_listgid, Opt_listmode,
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"},
85 static int parse_options(struct super_block *s, char *data)
90 /* (re)set to defaults. */
97 devmode = S_IWUSR | S_IRUGO;
98 busmode = S_IXUGO | S_IRUGO;
101 while ((p = strsep(&data, ",")) != NULL) {
102 substring_t args[MAX_OPT_ARGS];
107 token = match_token(p, tokens, args);
110 if (match_int(&args[0], &option))
115 if (match_int(&args[0], &option))
120 if (match_octal(&args[0], &option))
122 devmode = option & S_IRWXUGO;
125 if (match_int(&args[0], &option))
130 if (match_int(&args[0], &option))
135 if (match_octal(&args[0], &option))
137 busmode = option & S_IRWXUGO;
140 if (match_int(&args[0], &option))
145 if (match_int(&args[0], &option))
150 if (match_octal(&args[0], &option))
152 listmode = option & S_IRWXUGO;
155 err("usbfs: unrecognised mount option \"%s\" "
156 "or missing value\n", p);
164 static void update_special(struct dentry *special)
166 special->d_inode->i_uid = listuid;
167 special->d_inode->i_gid = listgid;
168 special->d_inode->i_mode = S_IFREG | listmode;
171 static void update_dev(struct dentry *dev)
173 dev->d_inode->i_uid = devuid;
174 dev->d_inode->i_gid = devgid;
175 dev->d_inode->i_mode = S_IFREG | devmode;
178 static void update_bus(struct dentry *bus)
180 struct dentry *dev = NULL;
182 bus->d_inode->i_uid = busuid;
183 bus->d_inode->i_gid = busgid;
184 bus->d_inode->i_mode = S_IFDIR | busmode;
186 mutex_lock(&bus->d_inode->i_mutex);
188 list_for_each_entry(dev, &bus->d_subdirs, d_u.d_child)
192 mutex_unlock(&bus->d_inode->i_mutex);
195 static void update_sb(struct super_block *sb)
197 struct dentry *root = sb->s_root;
198 struct dentry *bus = NULL;
203 mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT);
205 list_for_each_entry(bus, &root->d_subdirs, d_u.d_child) {
207 switch (S_IFMT & bus->d_inode->i_mode) {
215 warn("Unknown node %s mode %x found on remount!\n",bus->d_name.name,bus->d_inode->i_mode);
221 mutex_unlock(&root->d_inode->i_mutex);
224 static int remount(struct super_block *sb, int *flags, char *data)
226 /* If this is not a real mount,
227 * i.e. it's a simple_pin_fs from create_special_files,
233 if (parse_options(sb, data)) {
234 warn("usbfs: mount parameter error:");
238 if (usbfs_mount && usbfs_mount->mnt_sb)
239 update_sb(usbfs_mount->mnt_sb);
244 static struct inode *usbfs_get_inode (struct super_block *sb, int mode, dev_t dev)
246 struct inode *inode = new_inode(sb);
249 inode->i_mode = mode;
250 inode->i_uid = current->fsuid;
251 inode->i_gid = current->fsgid;
253 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
254 switch (mode & S_IFMT) {
256 init_special_inode(inode, mode, dev);
259 inode->i_fop = &default_file_operations;
262 inode->i_op = &simple_dir_inode_operations;
263 inode->i_fop = &simple_dir_operations;
265 /* directory inodes start off with i_nlink == 2 (for "." entry) */
274 static int usbfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
277 struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
284 d_instantiate(dentry, inode);
291 static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
295 mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
296 res = usbfs_mknod (dir, dentry, mode, 0);
302 static int usbfs_create (struct inode *dir, struct dentry *dentry, int mode)
304 mode = (mode & S_IALLUGO) | S_IFREG;
305 return usbfs_mknod (dir, dentry, mode, 0);
308 static inline int usbfs_positive (struct dentry *dentry)
310 return dentry->d_inode && !d_unhashed(dentry);
313 static int usbfs_empty (struct dentry *dentry)
315 struct list_head *list;
317 spin_lock(&dcache_lock);
319 list_for_each(list, &dentry->d_subdirs) {
320 struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
321 if (usbfs_positive(de)) {
322 spin_unlock(&dcache_lock);
327 spin_unlock(&dcache_lock);
331 static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
333 struct inode *inode = dentry->d_inode;
334 mutex_lock(&inode->i_mutex);
335 drop_nlink(dentry->d_inode);
337 mutex_unlock(&inode->i_mutex);
342 static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
344 int error = -ENOTEMPTY;
345 struct inode * inode = dentry->d_inode;
347 mutex_lock(&inode->i_mutex);
348 dentry_unhash(dentry);
349 if (usbfs_empty(dentry)) {
350 drop_nlink(dentry->d_inode);
351 drop_nlink(dentry->d_inode);
353 inode->i_flags |= S_DEAD;
357 mutex_unlock(&inode->i_mutex);
365 /* default file operations */
366 static ssize_t default_read_file (struct file *file, char __user *buf,
367 size_t count, loff_t *ppos)
372 static ssize_t default_write_file (struct file *file, const char __user *buf,
373 size_t count, loff_t *ppos)
378 static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
380 loff_t retval = -EINVAL;
382 mutex_lock(&file->f_dentry->d_inode->i_mutex);
386 file->f_pos = offset;
387 retval = file->f_pos;
391 if ((offset + file->f_pos) > 0) {
392 file->f_pos += offset;
393 retval = file->f_pos;
399 mutex_unlock(&file->f_dentry->d_inode->i_mutex);
403 static int default_open (struct inode *inode, struct file *file)
405 if (inode->i_private)
406 file->private_data = inode->i_private;
411 static const 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,
418 static struct super_operations usbfs_ops = {
419 .statfs = simple_statfs,
420 .drop_inode = generic_delete_inode,
421 .remount_fs = remount,
424 static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
429 sb->s_blocksize = PAGE_CACHE_SIZE;
430 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
431 sb->s_magic = USBDEVICE_SUPER_MAGIC;
432 sb->s_op = &usbfs_ops;
434 inode = usbfs_get_inode(sb, S_IFDIR | 0755, 0);
437 dbg("%s: could not get inode!",__FUNCTION__);
441 root = d_alloc_root(inode);
443 dbg("%s: could not get root dentry!",__FUNCTION__);
452 * fs_create_by_name - create a file, given a name
453 * @name: name of file
454 * @mode: type of file
455 * @parent: dentry of directory to create it in
456 * @dentry: resulting dentry of file
458 * This function handles both regular files and directories.
460 static int fs_create_by_name (const char *name, mode_t mode,
461 struct dentry *parent, struct dentry **dentry)
465 /* If the parent is not specified, we create it in the root.
466 * We need the root dentry to do this, which is in the super
467 * block. A pointer to that is in the struct vfsmount that we
471 if (usbfs_mount && usbfs_mount->mnt_sb) {
472 parent = usbfs_mount->mnt_sb->s_root;
477 dbg("Ah! can not find a parent!");
482 mutex_lock(&parent->d_inode->i_mutex);
483 *dentry = lookup_one_len(name, parent, strlen(name));
484 if (!IS_ERR(dentry)) {
485 if ((mode & S_IFMT) == S_IFDIR)
486 error = usbfs_mkdir (parent->d_inode, *dentry, mode);
488 error = usbfs_create (parent->d_inode, *dentry, mode);
490 error = PTR_ERR(dentry);
491 mutex_unlock(&parent->d_inode->i_mutex);
496 static struct dentry *fs_create_file (const char *name, mode_t mode,
497 struct dentry *parent, void *data,
498 const struct file_operations *fops,
499 uid_t uid, gid_t gid)
501 struct dentry *dentry;
504 dbg("creating file '%s'",name);
506 error = fs_create_by_name (name, mode, parent, &dentry);
510 if (dentry->d_inode) {
512 dentry->d_inode->i_private = data;
514 dentry->d_inode->i_fop = fops;
515 dentry->d_inode->i_uid = uid;
516 dentry->d_inode->i_gid = gid;
523 static void fs_remove_file (struct dentry *dentry)
525 struct dentry *parent = dentry->d_parent;
527 if (!parent || !parent->d_inode)
530 mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_PARENT);
531 if (usbfs_positive(dentry)) {
532 if (dentry->d_inode) {
533 if (S_ISDIR(dentry->d_inode->i_mode))
534 usbfs_rmdir(parent->d_inode, dentry);
536 usbfs_unlink(parent->d_inode, dentry);
540 mutex_unlock(&parent->d_inode->i_mutex);
543 /* --------------------------------------------------------------------- */
545 static int usb_get_sb(struct file_system_type *fs_type,
546 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
548 return get_sb_single(fs_type, flags, data, usbfs_fill_super, mnt);
551 static struct file_system_type usb_fs_type = {
552 .owner = THIS_MODULE,
554 .get_sb = usb_get_sb,
555 .kill_sb = kill_litter_super,
558 /* --------------------------------------------------------------------- */
560 static int create_special_files (void)
562 struct dentry *parent;
565 /* the simple_pin_fs calls will call remount with no options
566 * without this flag that would overwrite the real mount options (if any)
570 /* create the devices special file */
571 retval = simple_pin_fs(&usb_fs_type, &usbfs_mount, &usbfs_mount_count);
573 err ("Unable to get usbfs mount");
579 parent = usbfs_mount->mnt_sb->s_root;
580 devices_usbfs_dentry = fs_create_file ("devices",
581 listmode | S_IFREG, parent,
582 NULL, &usbfs_devices_fops,
584 if (devices_usbfs_dentry == NULL) {
585 err ("Unable to create devices usbfs file");
587 goto error_clean_mounts;
593 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
598 static void remove_special_files (void)
600 if (devices_usbfs_dentry)
601 fs_remove_file (devices_usbfs_dentry);
602 devices_usbfs_dentry = NULL;
603 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
606 void usbfs_update_special (void)
610 if (devices_usbfs_dentry) {
611 inode = devices_usbfs_dentry->d_inode;
613 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
617 static void usbfs_add_bus(struct usb_bus *bus)
619 struct dentry *parent;
623 /* create the special files if this is the first bus added */
624 if (num_buses == 0) {
625 retval = create_special_files();
631 sprintf (name, "%03d", bus->busnum);
633 parent = usbfs_mount->mnt_sb->s_root;
634 bus->usbfs_dentry = fs_create_file (name, busmode | S_IFDIR, parent,
635 bus, NULL, busuid, busgid);
636 if (bus->usbfs_dentry == NULL) {
637 err ("error creating usbfs bus entry");
642 static void usbfs_remove_bus(struct usb_bus *bus)
644 if (bus->usbfs_dentry) {
645 fs_remove_file (bus->usbfs_dentry);
646 bus->usbfs_dentry = NULL;
650 if (num_buses <= 0) {
651 remove_special_files();
656 static void usbfs_add_device(struct usb_device *dev)
662 sprintf (name, "%03d", dev->devnum);
663 dev->usbfs_dentry = fs_create_file (name, devmode | S_IFREG,
664 dev->bus->usbfs_dentry, dev,
665 &usbfs_device_file_operations,
667 if (dev->usbfs_dentry == NULL) {
668 err ("error creating usbfs device entry");
672 /* Set the size of the device's file to be
673 * equal to the size of the device descriptors. */
674 i_size = sizeof (struct usb_device_descriptor);
675 for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
676 struct usb_config_descriptor *config =
677 (struct usb_config_descriptor *)dev->rawdescriptors[i];
678 i_size += le16_to_cpu(config->wTotalLength);
680 if (dev->usbfs_dentry->d_inode)
681 dev->usbfs_dentry->d_inode->i_size = i_size;
684 static void usbfs_remove_device(struct usb_device *dev)
686 struct dev_state *ds;
687 struct siginfo sinfo;
689 if (dev->usbfs_dentry) {
690 fs_remove_file (dev->usbfs_dentry);
691 dev->usbfs_dentry = NULL;
693 while (!list_empty(&dev->filelist)) {
694 ds = list_entry(dev->filelist.next, struct dev_state, list);
695 wake_up_all(&ds->wait);
696 list_del_init(&ds->list);
698 sinfo.si_signo = ds->discsignr;
699 sinfo.si_errno = EPIPE;
700 sinfo.si_code = SI_ASYNCIO;
701 sinfo.si_addr = ds->disccontext;
702 kill_pid_info_as_uid(ds->discsignr, &sinfo, ds->disc_pid, ds->disc_uid, ds->disc_euid, ds->secid);
707 static int usbfs_notify(struct notifier_block *self, unsigned long action, void *dev)
711 usbfs_add_device(dev);
713 case USB_DEVICE_REMOVE:
714 usbfs_remove_device(dev);
720 usbfs_remove_bus(dev);
723 usbfs_update_special();
724 usbfs_conn_disc_event();
728 static struct notifier_block usbfs_nb = {
729 .notifier_call = usbfs_notify,
732 /* --------------------------------------------------------------------- */
734 static struct proc_dir_entry *usbdir = NULL;
736 int __init usbfs_init(void)
740 retval = register_filesystem(&usb_fs_type);
744 usb_register_notify(&usbfs_nb);
746 /* create mount point for usbfs */
747 usbdir = proc_mkdir("usb", proc_bus);
752 void usbfs_cleanup(void)
754 usb_unregister_notify(&usbfs_nb);
755 unregister_filesystem(&usb_fs_type);
757 remove_proc_entry("usb", proc_bus);