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/config.h>
31 #include <linux/module.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>
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;
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 down(&bus->d_inode->i_sem);
188 list_for_each_entry(dev, &bus->d_subdirs, d_child)
192 up(&bus->d_inode->i_sem);
195 static void update_sb(struct super_block *sb)
197 struct dentry *root = sb->s_root;
198 struct dentry *bus = NULL;
203 down(&root->d_inode->i_sem);
205 list_for_each_entry(bus, &root->d_subdirs, 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 up(&root->d_inode->i_sem);
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;
252 inode->i_blksize = PAGE_CACHE_SIZE;
254 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
255 switch (mode & S_IFMT) {
257 init_special_inode(inode, mode, dev);
260 inode->i_fop = &default_file_operations;
263 inode->i_op = &usbfs_dir_inode_operations;
264 inode->i_fop = &simple_dir_operations;
266 /* directory inodes start off with i_nlink == 2 (for "." entry) */
275 static int usbfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
278 struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
285 d_instantiate(dentry, inode);
292 static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
296 mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
297 res = usbfs_mknod (dir, dentry, mode, 0);
303 static int usbfs_create (struct inode *dir, struct dentry *dentry, int mode)
305 mode = (mode & S_IALLUGO) | S_IFREG;
306 return usbfs_mknod (dir, dentry, mode, 0);
309 static inline int usbfs_positive (struct dentry *dentry)
311 return dentry->d_inode && !d_unhashed(dentry);
314 static int usbfs_empty (struct dentry *dentry)
316 struct list_head *list;
318 spin_lock(&dcache_lock);
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);
328 spin_unlock(&dcache_lock);
332 static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
334 struct inode *inode = dentry->d_inode;
336 dentry->d_inode->i_nlink--;
343 static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
345 int error = -ENOTEMPTY;
346 struct inode * inode = dentry->d_inode;
349 dentry_unhash(dentry);
350 if (usbfs_empty(dentry)) {
351 dentry->d_inode->i_nlink -= 2;
353 inode->i_flags |= S_DEAD;
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 down(&file->f_dentry->d_inode->i_sem);
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 up(&file->f_dentry->d_inode->i_sem);
403 static int default_open (struct inode *inode, struct file *file)
405 if (inode->u.generic_ip)
406 file->private_data = inode->u.generic_ip;
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,
418 static struct inode_operations usbfs_dir_inode_operations = {
419 .lookup = simple_lookup,
422 static struct super_operations usbfs_ops = {
423 .statfs = simple_statfs,
424 .drop_inode = generic_delete_inode,
425 .remount_fs = remount,
428 static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
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;
438 inode = usbfs_get_inode(sb, S_IFDIR | 0755, 0);
441 dbg("%s: could not get inode!",__FUNCTION__);
445 root = d_alloc_root(inode);
447 dbg("%s: could not get root dentry!",__FUNCTION__);
455 static struct dentry * get_dentry(struct dentry *parent, const char *name)
460 qstr.len = strlen(name);
461 qstr.hash = full_name_hash(name,qstr.len);
462 return lookup_hash(&qstr,parent);
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
473 * This function handles both regular files and directories.
475 static int fs_create_by_name (const char *name, mode_t mode,
476 struct dentry *parent, struct dentry **dentry)
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
486 if (usbfs_mount && usbfs_mount->mnt_sb) {
487 parent = usbfs_mount->mnt_sb->s_root;
492 dbg("Ah! can not find a parent!");
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);
503 error = usbfs_create (parent->d_inode, *dentry, mode);
505 error = PTR_ERR(dentry);
506 up(&parent->d_inode->i_sem);
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)
516 struct dentry *dentry;
519 dbg("creating file '%s'",name);
521 error = fs_create_by_name (name, mode, parent, &dentry);
525 if (dentry->d_inode) {
527 dentry->d_inode->u.generic_ip = data;
529 dentry->d_inode->i_fop = fops;
530 dentry->d_inode->i_uid = uid;
531 dentry->d_inode->i_gid = gid;
538 static void fs_remove_file (struct dentry *dentry)
540 struct dentry *parent = dentry->d_parent;
542 if (!parent || !parent->d_inode)
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);
551 usbfs_unlink(parent->d_inode, dentry);
555 up(&parent->d_inode->i_sem);
558 /* --------------------------------------------------------------------- */
560 static struct super_block *usb_get_sb(struct file_system_type *fs_type,
561 int flags, const char *dev_name, void *data)
563 return get_sb_single(fs_type, flags, data, usbfs_fill_super);
566 static struct file_system_type usb_fs_type = {
567 .owner = THIS_MODULE,
569 .get_sb = usb_get_sb,
570 .kill_sb = kill_litter_super,
573 /* --------------------------------------------------------------------- */
575 static int create_special_files (void)
577 struct dentry *parent;
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)
585 /* create the devices special file */
586 retval = simple_pin_fs("usbfs", &usbfs_mount, &usbfs_mount_count);
588 err ("Unable to get usbfs mount");
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,
599 if (devices_usbfs_dentry == NULL) {
600 err ("Unable to create devices usbfs file");
602 goto error_clean_mounts;
608 simple_release_fs(&usbfs_mount, &usbfs_mount_count);
613 static void remove_special_files (void)
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);
621 void usbfs_update_special (void)
625 if (devices_usbfs_dentry) {
626 inode = devices_usbfs_dentry->d_inode;
628 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
632 void usbfs_add_bus(struct usb_bus *bus)
634 struct dentry *parent;
638 /* create the special files if this is the first bus added */
639 if (num_buses == 0) {
640 retval = create_special_files();
646 sprintf (name, "%03d", bus->busnum);
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");
656 usbfs_update_special();
657 usbfs_conn_disc_event();
660 void usbfs_remove_bus(struct usb_bus *bus)
662 if (bus->usbfs_dentry) {
663 fs_remove_file (bus->usbfs_dentry);
664 bus->usbfs_dentry = NULL;
668 if (num_buses <= 0) {
669 remove_special_files();
673 usbfs_update_special();
674 usbfs_conn_disc_event();
677 void usbfs_add_device(struct usb_device *dev)
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,
688 if (dev->usbfs_dentry == NULL) {
689 err ("error creating usbfs device entry");
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);
701 if (dev->usbfs_dentry->d_inode)
702 dev->usbfs_dentry->d_inode->i_size = i_size;
704 usbfs_update_special();
705 usbfs_conn_disc_event();
708 void usbfs_remove_device(struct usb_device *dev)
710 struct dev_state *ds;
711 struct siginfo sinfo;
713 if (dev->usbfs_dentry) {
714 fs_remove_file (dev->usbfs_dentry);
715 dev->usbfs_dentry = NULL;
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);
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);
729 usbfs_update_special();
730 usbfs_conn_disc_event();
733 /* --------------------------------------------------------------------- */
735 static struct proc_dir_entry *usbdir = NULL;
737 int __init usbfs_init(void)
741 retval = usb_register(&usbfs_driver);
745 retval = register_filesystem(&usb_fs_type);
747 usb_deregister(&usbfs_driver);
751 /* create mount point for usbfs */
752 usbdir = proc_mkdir("usb", proc_bus);
757 void usbfs_cleanup(void)
759 usb_deregister(&usbfs_driver);
760 unregister_filesystem(&usb_fs_type);
762 remove_proc_entry("usb", proc_bus);