[net-next-2.6.git] / drivers / usb / core / inode.c

/*****************************************************************************/

/*
 *	inode.c  --  Inode/Dentry functions for the USB device file system.
 *
 *	Copyright (C) 2000 Thomas Sailer (sailer@ife.ee.ethz.ch)
 *	Copyright (C) 2001,2002,2004 Greg Kroah-Hartman (greg@kroah.com)
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License
 *	along with this program; if not, write to the Free Software
 *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  History:
 *   0.1  04.01.2000  Created
 *   0.2  10.12.2001  converted to use the vfs layer better
 */

/*****************************************************************************/

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/usb.h>
#include <linux/namei.h>
#include <linux/usbdevice_fs.h>
#include <linux/parser.h>
#include <linux/notifier.h>
#include <asm/byteorder.h>
#include "usb.h"
#include "hcd.h"

static struct super_operations usbfs_ops;
static const struct file_operations default_file_operations;
static struct vfsmount *usbfs_mount;
static int usbfs_mount_count;	/* = 0 */
static int ignore_mount = 0;

static struct dentry *devices_usbfs_dentry;
static int num_buses;	/* = 0 */

static uid_t devuid;	/* = 0 */
static uid_t busuid;	/* = 0 */
static uid_t listuid;	/* = 0 */
static gid_t devgid;	/* = 0 */
static gid_t busgid;	/* = 0 */
static gid_t listgid;	/* = 0 */
static umode_t devmode = S_IWUSR | S_IRUGO;
static umode_t busmode = S_IXUGO | S_IRUGO;
static umode_t listmode = S_IRUGO;

enum {
	Opt_devuid, Opt_devgid, Opt_devmode,
	Opt_busuid, Opt_busgid, Opt_busmode,
	Opt_listuid, Opt_listgid, Opt_listmode,
	Opt_err,
};

static match_table_t tokens = {
	{Opt_devuid, "devuid=%u"},
	{Opt_devgid, "devgid=%u"},
	{Opt_devmode, "devmode=%o"},
	{Opt_busuid, "busuid=%u"},
	{Opt_busgid, "busgid=%u"},
	{Opt_busmode, "busmode=%o"},
	{Opt_listuid, "listuid=%u"},
	{Opt_listgid, "listgid=%u"},
	{Opt_listmode, "listmode=%o"},
	{Opt_err, NULL}
};

static int parse_options(struct super_block *s, char *data)
{
	char *p;
	int option;

	/* (re)set to defaults. */
	devuid = 0;
	busuid = 0;
	listuid = 0;
	devgid = 0;
	busgid = 0;
	listgid = 0;
	devmode = S_IWUSR | S_IRUGO;
	busmode = S_IXUGO | S_IRUGO;
	listmode = S_IRUGO;

	while ((p = strsep(&data, ",")) != NULL) {
		substring_t args[MAX_OPT_ARGS];
		int token;
		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
		case Opt_devuid:
			if (match_int(&args[0], &option))
			       return -EINVAL;
			devuid = option;
			break;
		case Opt_devgid:
			if (match_int(&args[0], &option))
			       return -EINVAL;
			devgid = option;
			break;
		case Opt_devmode:
			if (match_octal(&args[0], &option))
				return -EINVAL;
			devmode = option & S_IRWXUGO;
			break;
		case Opt_busuid:
			if (match_int(&args[0], &option))
			       return -EINVAL;
			busuid = option;
			break;
		case Opt_busgid:
			if (match_int(&args[0], &option))
			       return -EINVAL;
			busgid = option;
			break;
		case Opt_busmode:
			if (match_octal(&args[0], &option))
				return -EINVAL;
			busmode = option & S_IRWXUGO;
			break;
		case Opt_listuid:
			if (match_int(&args[0], &option))
			       return -EINVAL;
			listuid = option;
			break;
		case Opt_listgid:
			if (match_int(&args[0], &option))
			       return -EINVAL;
			listgid = option;
			break;
		case Opt_listmode:
			if (match_octal(&args[0], &option))
				return -EINVAL;
			listmode = option & S_IRWXUGO;
			break;
		default:
			err("usbfs: unrecognised mount option \"%s\" "
			    "or missing value\n", p);
			return -EINVAL;
		}
	}

	return 0;
}

static void update_special(struct dentry *special)
{
	special->d_inode->i_uid = listuid;
	special->d_inode->i_gid = listgid;
	special->d_inode->i_mode = S_IFREG | listmode;
}

static void update_dev(struct dentry *dev)
{
	dev->d_inode->i_uid = devuid;
	dev->d_inode->i_gid = devgid;
	dev->d_inode->i_mode = S_IFREG | devmode;
}

static void update_bus(struct dentry *bus)
{
	struct dentry *dev = NULL;

	bus->d_inode->i_uid = busuid;
	bus->d_inode->i_gid = busgid;
	bus->d_inode->i_mode = S_IFDIR | busmode;

	mutex_lock(&bus->d_inode->i_mutex);

	list_for_each_entry(dev, &bus->d_subdirs, d_u.d_child)
		if (dev->d_inode)
			update_dev(dev);

	mutex_unlock(&bus->d_inode->i_mutex);
}

static void update_sb(struct super_block *sb)
{
	struct dentry *root = sb->s_root;
	struct dentry *bus = NULL;

	if (!root)
		return;

	mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT);

	list_for_each_entry(bus, &root->d_subdirs, d_u.d_child) {
		if (bus->d_inode) {
			switch (S_IFMT & bus->d_inode->i_mode) {
			case S_IFDIR:
				update_bus(bus);
				break;
			case S_IFREG:
				update_special(bus);
				break;
			default:
				warn("Unknown node %s mode %x found on remount!\n",bus->d_name.name,bus->d_inode->i_mode);
				break;
			}
		}
	}

	mutex_unlock(&root->d_inode->i_mutex);
}

static int remount(struct super_block *sb, int *flags, char *data)
{
	/* If this is not a real mount,
	 * i.e. it's a simple_pin_fs from create_special_files,
	 * then ignore it.
	 */
	if (ignore_mount)
		return 0;

	if (parse_options(sb, data)) {
		warn("usbfs: mount parameter error:");
		return -EINVAL;
	}

	if (usbfs_mount && usbfs_mount->mnt_sb)
		update_sb(usbfs_mount->mnt_sb);

	return 0;
}

static struct inode *usbfs_get_inode (struct super_block *sb, int mode, dev_t dev)
{
	struct inode *inode = new_inode(sb);

	if (inode) {
		inode->i_mode = mode;
		inode->i_uid = current->fsuid;
		inode->i_gid = current->fsgid;
		inode->i_blocks = 0;
		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
		switch (mode & S_IFMT) {
		default:
			init_special_inode(inode, mode, dev);
			break;
		case S_IFREG:
			inode->i_fop = &default_file_operations;
			break;
		case S_IFDIR:
			inode->i_op = &simple_dir_inode_operations;
			inode->i_fop = &simple_dir_operations;

			/* directory inodes start off with i_nlink == 2 (for "." entry) */
			inc_nlink(inode);
			break;
		}
	}
	return inode; 
}

/* SMP-safe */
static int usbfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
			dev_t dev)
{
	struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
	int error = -EPERM;

	if (dentry->d_inode)
		return -EEXIST;

	if (inode) {
		d_instantiate(dentry, inode);
		dget(dentry);
		error = 0;
	}
	return error;
}

static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
{
	int res;

	mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
	res = usbfs_mknod (dir, dentry, mode, 0);
	if (!res)
		inc_nlink(dir);
	return res;
}

static int usbfs_create (struct inode *dir, struct dentry *dentry, int mode)
{
	mode = (mode & S_IALLUGO) | S_IFREG;
	return usbfs_mknod (dir, dentry, mode, 0);
}

static inline int usbfs_positive (struct dentry *dentry)
{
	return dentry->d_inode && !d_unhashed(dentry);
}

static int usbfs_empty (struct dentry *dentry)
{
	struct list_head *list;

	spin_lock(&dcache_lock);

	list_for_each(list, &dentry->d_subdirs) {
		struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
		if (usbfs_positive(de)) {
			spin_unlock(&dcache_lock);
			return 0;
		}
	}

	spin_unlock(&dcache_lock);
	return 1;
}

static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	mutex_lock(&inode->i_mutex);
	drop_nlink(dentry->d_inode);
	dput(dentry);
	mutex_unlock(&inode->i_mutex);
	d_delete(dentry);
	return 0;
}

static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	int error = -ENOTEMPTY;
	struct inode * inode = dentry->d_inode;

	mutex_lock(&inode->i_mutex);
	dentry_unhash(dentry);
	if (usbfs_empty(dentry)) {
		drop_nlink(dentry->d_inode);
		drop_nlink(dentry->d_inode);
		dput(dentry);
		inode->i_flags |= S_DEAD;
		drop_nlink(dir);
		error = 0;
	}
	mutex_unlock(&inode->i_mutex);
	if (!error)
		d_delete(dentry);
	dput(dentry);
	return error;
}


/* default file operations */
static ssize_t default_read_file (struct file *file, char __user *buf,
				  size_t count, loff_t *ppos)
{
	return 0;
}

static ssize_t default_write_file (struct file *file, const char __user *buf,
				   size_t count, loff_t *ppos)
{
	return count;
}

static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
{
	loff_t retval = -EINVAL;

	mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
	switch(orig) {
	case 0:
		if (offset > 0) {
			file->f_pos = offset;
			retval = file->f_pos;
		} 
		break;
	case 1:
		if ((offset + file->f_pos) > 0) {
			file->f_pos += offset;
			retval = file->f_pos;
		} 
		break;
	default:
		break;
	}
	mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
	return retval;
}

static int default_open (struct inode *inode, struct file *file)
{
	if (inode->i_private)
		file->private_data = inode->i_private;

	return 0;
}

static const struct file_operations default_file_operations = {
	.read =		default_read_file,
	.write =	default_write_file,
	.open =		default_open,
	.llseek =	default_file_lseek,
};

static struct super_operations usbfs_ops = {
	.statfs =	simple_statfs,
	.drop_inode =	generic_delete_inode,
	.remount_fs =	remount,
};

static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
{
	struct inode *inode;
	struct dentry *root;

	sb->s_blocksize = PAGE_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	sb->s_magic = USBDEVICE_SUPER_MAGIC;
	sb->s_op = &usbfs_ops;
	sb->s_time_gran = 1;
	inode = usbfs_get_inode(sb, S_IFDIR | 0755, 0);

	if (!inode) {
		dbg("%s: could not get inode!",__FUNCTION__);
		return -ENOMEM;
	}

	root = d_alloc_root(inode);
	if (!root) {
		dbg("%s: could not get root dentry!",__FUNCTION__);
		iput(inode);
		return -ENOMEM;
	}
	sb->s_root = root;
	return 0;
}

/*
 * fs_create_by_name - create a file, given a name
 * @name:	name of file
 * @mode:	type of file
 * @parent:	dentry of directory to create it in
 * @dentry:	resulting dentry of file
 *
 * This function handles both regular files and directories.
 */
static int fs_create_by_name (const char *name, mode_t mode,
			      struct dentry *parent, struct dentry **dentry)
{
	int error = 0;

	/* If the parent is not specified, we create it in the root.
	 * We need the root dentry to do this, which is in the super 
	 * block. A pointer to that is in the struct vfsmount that we
	 * have around.
	 */
	if (!parent ) {
		if (usbfs_mount && usbfs_mount->mnt_sb) {
			parent = usbfs_mount->mnt_sb->s_root;
		}
	}

	if (!parent) {
		dbg("Ah! can not find a parent!");
		return -EFAULT;
	}

	*dentry = NULL;
	mutex_lock(&parent->d_inode->i_mutex);
	*dentry = lookup_one_len(name, parent, strlen(name));
	if (!IS_ERR(dentry)) {
		if ((mode & S_IFMT) == S_IFDIR)
			error = usbfs_mkdir (parent->d_inode, *dentry, mode);
		else 
			error = usbfs_create (parent->d_inode, *dentry, mode);
	} else
		error = PTR_ERR(dentry);
	mutex_unlock(&parent->d_inode->i_mutex);

	return error;
}

static struct dentry *fs_create_file (const char *name, mode_t mode,
				      struct dentry *parent, void *data,
				      const struct file_operations *fops,
				      uid_t uid, gid_t gid)
{
	struct dentry *dentry;
	int error;

	dbg("creating file '%s'",name);

	error = fs_create_by_name (name, mode, parent, &dentry);
	if (error) {
		dentry = NULL;
	} else {
		if (dentry->d_inode) {
			if (data)
				dentry->d_inode->i_private = data;
			if (fops)
				dentry->d_inode->i_fop = fops;
			dentry->d_inode->i_uid = uid;
			dentry->d_inode->i_gid = gid;
		}
	}

	return dentry;
}

static void fs_remove_file (struct dentry *dentry)
{
	struct dentry *parent = dentry->d_parent;
	
	if (!parent || !parent->d_inode)
		return;

	mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_PARENT);
	if (usbfs_positive(dentry)) {
		if (dentry->d_inode) {
			if (S_ISDIR(dentry->d_inode->i_mode))
				usbfs_rmdir(parent->d_inode, dentry);
			else
				usbfs_unlink(parent->d_inode, dentry);
		dput(dentry);
		}
	}
	mutex_unlock(&parent->d_inode->i_mutex);
}

/* --------------------------------------------------------------------- */

static int usb_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_single(fs_type, flags, data, usbfs_fill_super, mnt);
}

static struct file_system_type usb_fs_type = {
	.owner =	THIS_MODULE,
	.name =		"usbfs",
	.get_sb =	usb_get_sb,
	.kill_sb =	kill_litter_super,
};

/* --------------------------------------------------------------------- */

static int create_special_files (void)
{
	struct dentry *parent;
	int retval;

	/* the simple_pin_fs calls will call remount with no options
	 * without this flag that would overwrite the real mount options (if any)
	 */
	ignore_mount = 1;

	/* create the devices special file */
	retval = simple_pin_fs(&usb_fs_type, &usbfs_mount, &usbfs_mount_count);
	if (retval) {
		err ("Unable to get usbfs mount");
		goto exit;
	}

	ignore_mount = 0;

	parent = usbfs_mount->mnt_sb->s_root;
	devices_usbfs_dentry = fs_create_file ("devices",
					       listmode | S_IFREG, parent,
					       NULL, &usbfs_devices_fops,
					       listuid, listgid);
	if (devices_usbfs_dentry == NULL) {
		err ("Unable to create devices usbfs file");
		retval = -ENODEV;
		goto error_clean_mounts;
	}

	goto exit;
	
error_clean_mounts:
	simple_release_fs(&usbfs_mount, &usbfs_mount_count);
exit:
	return retval;
}

static void remove_special_files (void)
{
	if (devices_usbfs_dentry)
		fs_remove_file (devices_usbfs_dentry);
	devices_usbfs_dentry = NULL;
	simple_release_fs(&usbfs_mount, &usbfs_mount_count);
}

void usbfs_update_special (void)
{
	struct inode *inode;

	if (devices_usbfs_dentry) {
		inode = devices_usbfs_dentry->d_inode;
		if (inode)
			inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	}
}

static void usbfs_add_bus(struct usb_bus *bus)
{
	struct dentry *parent;
	char name[8];
	int retval;

	/* create the special files if this is the first bus added */
	if (num_buses == 0) {
		retval = create_special_files();
		if (retval)
			return;
	}
	++num_buses;

	sprintf (name, "%03d", bus->busnum);

	parent = usbfs_mount->mnt_sb->s_root;
	bus->usbfs_dentry = fs_create_file (name, busmode | S_IFDIR, parent,
					    bus, NULL, busuid, busgid);
	if (bus->usbfs_dentry == NULL) {
		err ("error creating usbfs bus entry");
		return;
	}
}

static void usbfs_remove_bus(struct usb_bus *bus)
{
	if (bus->usbfs_dentry) {
		fs_remove_file (bus->usbfs_dentry);
		bus->usbfs_dentry = NULL;
	}

	--num_buses;
	if (num_buses <= 0) {
		remove_special_files();
		num_buses = 0;
	}
}

static void usbfs_add_device(struct usb_device *dev)
{
	char name[8];
	int i;
	int i_size;

	sprintf (name, "%03d", dev->devnum);
	dev->usbfs_dentry = fs_create_file (name, devmode | S_IFREG,
					    dev->bus->usbfs_dentry, dev,
					    &usbdev_file_operations,
					    devuid, devgid);
	if (dev->usbfs_dentry == NULL) {
		err ("error creating usbfs device entry");
		return;
	}

	/* Set the size of the device's file to be
	 * equal to the size of the device descriptors. */
	i_size = sizeof (struct usb_device_descriptor);
	for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
		struct usb_config_descriptor *config =
			(struct usb_config_descriptor *)dev->rawdescriptors[i];
		i_size += le16_to_cpu(config->wTotalLength);
	}
	if (dev->usbfs_dentry->d_inode)
		dev->usbfs_dentry->d_inode->i_size = i_size;
}

static void usbfs_remove_device(struct usb_device *dev)
{
	struct dev_state *ds;
	struct siginfo sinfo;

	if (dev->usbfs_dentry) {
		fs_remove_file (dev->usbfs_dentry);
		dev->usbfs_dentry = NULL;
	}
	while (!list_empty(&dev->filelist)) {
		ds = list_entry(dev->filelist.next, struct dev_state, list);
		wake_up_all(&ds->wait);
		list_del_init(&ds->list);
		if (ds->discsignr) {
			sinfo.si_signo = ds->discsignr;
			sinfo.si_errno = EPIPE;
			sinfo.si_code = SI_ASYNCIO;
			sinfo.si_addr = ds->disccontext;
			kill_pid_info_as_uid(ds->discsignr, &sinfo, ds->disc_pid, ds->disc_uid, ds->disc_euid, ds->secid);
		}
	}
}

static int usbfs_notify(struct notifier_block *self, unsigned long action, void *dev)
{
	switch (action) {
	case USB_DEVICE_ADD:
		usbfs_add_device(dev);
		break;
	case USB_DEVICE_REMOVE:
		usbfs_remove_device(dev);
		break;
	case USB_BUS_ADD:
		usbfs_add_bus(dev);
		break;
	case USB_BUS_REMOVE:
		usbfs_remove_bus(dev);
	}

	usbfs_update_special();
	usbfs_conn_disc_event();
	return NOTIFY_OK;
}

static struct notifier_block usbfs_nb = {
	.notifier_call = 	usbfs_notify,
};

/* --------------------------------------------------------------------- */

static struct proc_dir_entry *usbdir = NULL;

int __init usbfs_init(void)
{
	int retval;

	retval = register_filesystem(&usb_fs_type);
	if (retval)
		return retval;

	usb_register_notify(&usbfs_nb);

	/* create mount point for usbfs */
	usbdir = proc_mkdir("usb", proc_bus);

	return 0;
}

void usbfs_cleanup(void)
{
	usb_unregister_notify(&usbfs_nb);
	unregister_filesystem(&usb_fs_type);
	if (usbdir)
		remove_proc_entry("usb", proc_bus);
}
Commit	Line	Data
1da177e4 LT	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
1da177e4 LT	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>
1da177e4	39	#include <linux/parser.h>
54a5c4cd	40	#include <linux/notifier.h>
1da177e4 LT	41	#include <asm/byteorder.h>
1da177e4 LT	42	#include "usb.h"
6d5e8254	43	#include "hcd.h"
1da177e4 LT	44
1da177e4 LT	45	static struct super_operations usbfs_ops;
066202dd	46	static const struct file_operations default_file_operations;
1da177e4 LT	47	static struct vfsmount *usbfs_mount;
	48	static int usbfs_mount_count; /* = 0 */
	49	static int ignore_mount = 0;
	50
	51	static struct dentry *devices_usbfs_dentry;
	52	static int num_buses; /* = 0 */
	53
	54	static uid_t devuid; /* = 0 */
	55	static uid_t busuid; /* = 0 */
	56	static uid_t listuid; /* = 0 */
	57	static gid_t devgid; /* = 0 */
	58	static gid_t busgid; /* = 0 */
	59	static gid_t listgid; /* = 0 */
	60	static umode_t devmode = S_IWUSR \| S_IRUGO;
	61	static umode_t busmode = S_IXUGO \| S_IRUGO;
	62	static umode_t listmode = S_IRUGO;
	63
	64	enum {
	65	Opt_devuid, Opt_devgid, Opt_devmode,
	66	Opt_busuid, Opt_busgid, Opt_busmode,
	67	Opt_listuid, Opt_listgid, Opt_listmode,
	68	Opt_err,
	69	};
	70
	71	static match_table_t tokens = {
	72	{Opt_devuid, "devuid=%u"},
	73	{Opt_devgid, "devgid=%u"},
	74	{Opt_devmode, "devmode=%o"},
	75	{Opt_busuid, "busuid=%u"},
	76	{Opt_busgid, "busgid=%u"},
	77	{Opt_busmode, "busmode=%o"},
	78	{Opt_listuid, "listuid=%u"},
	79	{Opt_listgid, "listgid=%u"},
	80	{Opt_listmode, "listmode=%o"},
	81	{Opt_err, NULL}
	82	};
	83
	84	static int parse_options(struct super_block s, char data)
	85	{
	86	char *p;
	87	int option;
	88
	89	/* (re)set to defaults. */
	90	devuid = 0;
	91	busuid = 0;
	92	listuid = 0;
	93	devgid = 0;
	94	busgid = 0;
	95	listgid = 0;
	96	devmode = S_IWUSR \| S_IRUGO;
	97	busmode = S_IXUGO \| S_IRUGO;
	98	listmode = S_IRUGO;
	99
	100	while ((p = strsep(&data, ",")) != NULL) {
	101	substring_t args[MAX_OPT_ARGS];
	102	int token;
	103	if (!*p)
	104	continue;
	105
	106	token = match_token(p, tokens, args);
	107	switch (token) {
	108	case Opt_devuid:
	109	if (match_int(&args[0], &option))
	110	return -EINVAL;
111	devuid = option;
112	break;
113	case Opt_devgid:
114	if (match_int(&args[0], &option))
115	return -EINVAL;
116	devgid = option;
117	break;
118	case Opt_devmode:
119	if (match_octal(&args[0], &option))
120	return -EINVAL;
121	devmode = option & S_IRWXUGO;
122	break;
123	case Opt_busuid:
124	if (match_int(&args[0], &option))
125	return -EINVAL;
126	busuid = option;
127	break;
128	case Opt_busgid:
129	if (match_int(&args[0], &option))
130	return -EINVAL;
131	busgid = option;
132	break;
133	case Opt_busmode:
134	if (match_octal(&args[0], &option))
135	return -EINVAL;
136	busmode = option & S_IRWXUGO;
137	break;
138	case Opt_listuid:
139	if (match_int(&args[0], &option))
140	return -EINVAL;
141	listuid = option;
142	break;
143	case Opt_listgid:
144	if (match_int(&args[0], &option))
145	return -EINVAL;
146	listgid = option;
147	break;
148	case Opt_listmode:
149	if (match_octal(&args[0], &option))
150	return -EINVAL;
151	listmode = option & S_IRWXUGO;
152	break;
153	default:
154	err("usbfs: unrecognised mount option \"%s\" "
155	"or missing value\n", p);
156	return -EINVAL;
157	}
158	}
159
160	return 0;
161	}
162
163	static void update_special(struct dentry *special)
164	{
165	special->d_inode->i_uid = listuid;
166	special->d_inode->i_gid = listgid;
167	special->d_inode->i_mode = S_IFREG \| listmode;
168	}
169
170	static void update_dev(struct dentry *dev)
171	{
172	dev->d_inode->i_uid = devuid;
173	dev->d_inode->i_gid = devgid;
174	dev->d_inode->i_mode = S_IFREG \| devmode;
175	}
176
177	static void update_bus(struct dentry *bus)
178	{
179	struct dentry *dev = NULL;
180
181	bus->d_inode->i_uid = busuid;
182	bus->d_inode->i_gid = busgid;
183	bus->d_inode->i_mode = S_IFDIR \| busmode;
184
1b1dcc1b	185	mutex_lock(&bus->d_inode->i_mutex);
1da177e4	186
5160ee6f	187	list_for_each_entry(dev, &bus->d_subdirs, d_u.d_child)
1da177e4 LT	188	if (dev->d_inode)
	189	update_dev(dev);
	190
1b1dcc1b	191	mutex_unlock(&bus->d_inode->i_mutex);
1da177e4 LT	192	}
	193
	194	static void update_sb(struct super_block *sb)
	195	{
	196	struct dentry *root = sb->s_root;
	197	struct dentry *bus = NULL;
	198
	199	if (!root)
	200	return;
	201
f2eace23	202	mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT);
1da177e4	203
5160ee6f	204	list_for_each_entry(bus, &root->d_subdirs, d_u.d_child) {
1da177e4 LT	205	if (bus->d_inode) {
	206	switch (S_IFMT & bus->d_inode->i_mode) {
	207	case S_IFDIR:
	208	update_bus(bus);
	209	break;
	210	case S_IFREG:
	211	update_special(bus);
	212	break;
	213	default:
	214	warn("Unknown node %s mode %x found on remount!\n",bus->d_name.name,bus->d_inode->i_mode);
	215	break;
	216	}
	217	}
	218	}
	219
1b1dcc1b	220	mutex_unlock(&root->d_inode->i_mutex);
1da177e4 LT	221	}
	222
	223	static int remount(struct super_block sb, int flags, char *data)
	224	{
	225	/* If this is not a real mount,
	226	* i.e. it's a simple_pin_fs from create_special_files,
	227	* then ignore it.
	228	*/
	229	if (ignore_mount)
	230	return 0;
	231
	232	if (parse_options(sb, data)) {
	233	warn("usbfs: mount parameter error:");
	234	return -EINVAL;
	235	}
	236
	237	if (usbfs_mount && usbfs_mount->mnt_sb)
	238	update_sb(usbfs_mount->mnt_sb);
	239
	240	return 0;
	241	}
	242
	243	static struct inode usbfs_get_inode (struct super_block sb, int mode, dev_t dev)
	244	{
	245	struct inode *inode = new_inode(sb);
	246
	247	if (inode) {
	248	inode->i_mode = mode;
	249	inode->i_uid = current->fsuid;
	250	inode->i_gid = current->fsgid;
1da177e4 LT	251	inode->i_blocks = 0;
	252	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	253	switch (mode & S_IFMT) {
	254	default:
	255	init_special_inode(inode, mode, dev);
	256	break;
	257	case S_IFREG:
	258	inode->i_fop = &default_file_operations;
	259	break;
	260	case S_IFDIR:
bc7cb323	261	inode->i_op = &simple_dir_inode_operations;
1da177e4 LT	262	inode->i_fop = &simple_dir_operations;
	263
	264	/* directory inodes start off with i_nlink == 2 (for "." entry) */
d8c76e6f	265	inc_nlink(inode);
1da177e4 LT	266	break;
	267	}
	268	}
	269	return inode;
	270	}
	271
	272	/* SMP-safe */
	273	static int usbfs_mknod (struct inode dir, struct dentry dentry, int mode,
	274	dev_t dev)
	275	{
	276	struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
	277	int error = -EPERM;
	278
	279	if (dentry->d_inode)
	280	return -EEXIST;
	281
	282	if (inode) {
	283	d_instantiate(dentry, inode);
	284	dget(dentry);
	285	error = 0;
	286	}
	287	return error;
	288	}
	289
	290	static int usbfs_mkdir (struct inode dir, struct dentry dentry, int mode)
	291	{
	292	int res;
	293
	294	mode = (mode & (S_IRWXUGO \| S_ISVTX)) \| S_IFDIR;
	295	res = usbfs_mknod (dir, dentry, mode, 0);
	296	if (!res)
d8c76e6f	297	inc_nlink(dir);
1da177e4 LT	298	return res;
	299	}
	300
	301	static int usbfs_create (struct inode dir, struct dentry dentry, int mode)
	302	{
	303	mode = (mode & S_IALLUGO) \| S_IFREG;
	304	return usbfs_mknod (dir, dentry, mode, 0);
	305	}
	306
	307	static inline int usbfs_positive (struct dentry *dentry)
	308	{
	309	return dentry->d_inode && !d_unhashed(dentry);
	310	}
	311
	312	static int usbfs_empty (struct dentry *dentry)
	313	{
	314	struct list_head *list;
	315
	316	spin_lock(&dcache_lock);
	317
	318	list_for_each(list, &dentry->d_subdirs) {
5160ee6f	319	struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
1da177e4 LT	320	if (usbfs_positive(de)) {
	321	spin_unlock(&dcache_lock);
	322	return 0;
	323	}
	324	}
	325
	326	spin_unlock(&dcache_lock);
	327	return 1;
	328	}
	329
	330	static int usbfs_unlink (struct inode dir, struct dentry dentry)
	331	{
	332	struct inode *inode = dentry->d_inode;
1b1dcc1b	333	mutex_lock(&inode->i_mutex);
9a53c3a7	334	drop_nlink(dentry->d_inode);
1da177e4	335	dput(dentry);
1b1dcc1b	336	mutex_unlock(&inode->i_mutex);
1da177e4 LT	337	d_delete(dentry);
	338	return 0;
	339	}
	340
	341	static int usbfs_rmdir(struct inode dir, struct dentry dentry)
	342	{
	343	int error = -ENOTEMPTY;
	344	struct inode * inode = dentry->d_inode;
	345
1b1dcc1b	346	mutex_lock(&inode->i_mutex);
1da177e4 LT	347	dentry_unhash(dentry);
1da177e4 LT	348	if (usbfs_empty(dentry)) {
9a53c3a7 DH	349	drop_nlink(dentry->d_inode);
9a53c3a7 DH	350	drop_nlink(dentry->d_inode);
1da177e4 LT	351	dput(dentry);
1da177e4 LT	352	inode->i_flags \|= S_DEAD;
9a53c3a7	353	drop_nlink(dir);
1da177e4 LT	354	error = 0;
1da177e4 LT	355	}
1b1dcc1b	356	mutex_unlock(&inode->i_mutex);
1da177e4 LT	357	if (!error)
	358	d_delete(dentry);
	359	dput(dentry);
	360	return error;
	361	}
	362
	363
	364	/* default file operations */
	365	static ssize_t default_read_file (struct file file, char __user buf,
	366	size_t count, loff_t *ppos)
	367	{
	368	return 0;
	369	}
	370
	371	static ssize_t default_write_file (struct file file, const char __user buf,
	372	size_t count, loff_t *ppos)
	373	{
	374	return count;
	375	}
	376
	377	static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
	378	{
	379	loff_t retval = -EINVAL;
	380
33cb8994	381	mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
1da177e4 LT	382	switch(orig) {
	383	case 0:
	384	if (offset > 0) {
	385	file->f_pos = offset;
	386	retval = file->f_pos;
	387	}
	388	break;
	389	case 1:
	390	if ((offset + file->f_pos) > 0) {
	391	file->f_pos += offset;
	392	retval = file->f_pos;
	393	}
	394	break;
	395	default:
	396	break;
	397	}
33cb8994	398	mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
1da177e4 LT	399	return retval;
	400	}
	401
	402	static int default_open (struct inode inode, struct file file)
	403	{
8e18e294 TT	404	if (inode->i_private)
8e18e294 TT	405	file->private_data = inode->i_private;
1da177e4 LT	406
	407	return 0;
	408	}
	409
066202dd	410	static const struct file_operations default_file_operations = {
1da177e4 LT	411	.read = default_read_file,
	412	.write = default_write_file,
	413	.open = default_open,
	414	.llseek = default_file_lseek,
	415	};
	416
1da177e4 LT	417	static struct super_operations usbfs_ops = {
	418	.statfs = simple_statfs,
	419	.drop_inode = generic_delete_inode,
	420	.remount_fs = remount,
	421	};
	422
	423	static int usbfs_fill_super(struct super_block sb, void data, int silent)
	424	{
	425	struct inode *inode;
	426	struct dentry *root;
	427
	428	sb->s_blocksize = PAGE_CACHE_SIZE;
	429	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	430	sb->s_magic = USBDEVICE_SUPER_MAGIC;
	431	sb->s_op = &usbfs_ops;
	432	sb->s_time_gran = 1;
	433	inode = usbfs_get_inode(sb, S_IFDIR \| 0755, 0);
	434
	435	if (!inode) {
	436	dbg("%s: could not get inode!",__FUNCTION__);
	437	return -ENOMEM;
	438	}
	439
	440	root = d_alloc_root(inode);
	441	if (!root) {
	442	dbg("%s: could not get root dentry!",__FUNCTION__);
	443	iput(inode);
	444	return -ENOMEM;
	445	}
	446	sb->s_root = root;
	447	return 0;
	448	}
	449
1da177e4 LT	450	/*
	451	* fs_create_by_name - create a file, given a name
	452	* @name: name of file
	453	* @mode: type of file
	454	* @parent: dentry of directory to create it in
	455	* @dentry: resulting dentry of file
	456	*
	457	* This function handles both regular files and directories.
	458	*/
	459	static int fs_create_by_name (const char *name, mode_t mode,
	460	struct dentry parent, struct dentry *dentry)
	461	{
	462	int error = 0;
	463
	464	/* If the parent is not specified, we create it in the root.
	465	* We need the root dentry to do this, which is in the super
	466	* block. A pointer to that is in the struct vfsmount that we
	467	* have around.
	468	*/
	469	if (!parent ) {
	470	if (usbfs_mount && usbfs_mount->mnt_sb) {
	471	parent = usbfs_mount->mnt_sb->s_root;
	472	}
	473	}
	474
	475	if (!parent) {
	476	dbg("Ah! can not find a parent!");
	477	return -EFAULT;
	478	}
	479
	480	*dentry = NULL;
1b1dcc1b	481	mutex_lock(&parent->d_inode->i_mutex);
5f45f1a7	482	*dentry = lookup_one_len(name, parent, strlen(name));
1da177e4 LT	483	if (!IS_ERR(dentry)) {
	484	if ((mode & S_IFMT) == S_IFDIR)
	485	error = usbfs_mkdir (parent->d_inode, *dentry, mode);
	486	else
	487	error = usbfs_create (parent->d_inode, *dentry, mode);
	488	} else
	489	error = PTR_ERR(dentry);
1b1dcc1b	490	mutex_unlock(&parent->d_inode->i_mutex);
1da177e4 LT	491
	492	return error;
	493	}
	494
	495	static struct dentry fs_create_file (const char name, mode_t mode,
	496	struct dentry parent, void data,
066202dd	497	const struct file_operations *fops,
1da177e4 LT	498	uid_t uid, gid_t gid)
	499	{
	500	struct dentry *dentry;
	501	int error;
	502
	503	dbg("creating file '%s'",name);
	504
	505	error = fs_create_by_name (name, mode, parent, &dentry);
	506	if (error) {
	507	dentry = NULL;
	508	} else {
	509	if (dentry->d_inode) {
	510	if (data)
8e18e294	511	dentry->d_inode->i_private = data;
1da177e4 LT	512	if (fops)
	513	dentry->d_inode->i_fop = fops;
	514	dentry->d_inode->i_uid = uid;
	515	dentry->d_inode->i_gid = gid;
	516	}
	517	}
	518
	519	return dentry;
	520	}
	521
	522	static void fs_remove_file (struct dentry *dentry)
	523	{
	524	struct dentry *parent = dentry->d_parent;
	525
	526	if (!parent \|\| !parent->d_inode)
	527	return;
	528
8e7795ef	529	mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_PARENT);
1da177e4 LT	530	if (usbfs_positive(dentry)) {
	531	if (dentry->d_inode) {
	532	if (S_ISDIR(dentry->d_inode->i_mode))
	533	usbfs_rmdir(parent->d_inode, dentry);
	534	else
	535	usbfs_unlink(parent->d_inode, dentry);
	536	dput(dentry);
	537	}
	538	}
1b1dcc1b	539	mutex_unlock(&parent->d_inode->i_mutex);
1da177e4 LT	540	}
	541
	542	/* --------------------------------------------------------------------- */
	543
454e2398 DH	544	static int usb_get_sb(struct file_system_type *fs_type,
454e2398 DH	545	int flags, const char dev_name, void data, struct vfsmount *mnt)
1da177e4	546	{
454e2398	547	return get_sb_single(fs_type, flags, data, usbfs_fill_super, mnt);
1da177e4 LT	548	}
	549
	550	static struct file_system_type usb_fs_type = {
	551	.owner = THIS_MODULE,
	552	.name = "usbfs",
	553	.get_sb = usb_get_sb,
	554	.kill_sb = kill_litter_super,
	555	};
	556
	557	/* --------------------------------------------------------------------- */
	558
	559	static int create_special_files (void)
	560	{
	561	struct dentry *parent;
	562	int retval;
	563
	564	/* the simple_pin_fs calls will call remount with no options
	565	* without this flag that would overwrite the real mount options (if any)
	566	*/
	567	ignore_mount = 1;
	568
	569	/* create the devices special file */
1f5ce9e9	570	retval = simple_pin_fs(&usb_fs_type, &usbfs_mount, &usbfs_mount_count);
1da177e4 LT	571	if (retval) {
	572	err ("Unable to get usbfs mount");
	573	goto exit;
	574	}
	575
	576	ignore_mount = 0;
	577
	578	parent = usbfs_mount->mnt_sb->s_root;
	579	devices_usbfs_dentry = fs_create_file ("devices",
	580	listmode \| S_IFREG, parent,
	581	NULL, &usbfs_devices_fops,
	582	listuid, listgid);
	583	if (devices_usbfs_dentry == NULL) {
	584	err ("Unable to create devices usbfs file");
	585	retval = -ENODEV;
	586	goto error_clean_mounts;
	587	}
	588
	589	goto exit;
	590
	591	error_clean_mounts:
	592	simple_release_fs(&usbfs_mount, &usbfs_mount_count);
	593	exit:
	594	return retval;
	595	}
	596
	597	static void remove_special_files (void)
	598	{
	599	if (devices_usbfs_dentry)
	600	fs_remove_file (devices_usbfs_dentry);
	601	devices_usbfs_dentry = NULL;
	602	simple_release_fs(&usbfs_mount, &usbfs_mount_count);
	603	}
	604
	605	void usbfs_update_special (void)
	606	{
	607	struct inode *inode;
	608
	609	if (devices_usbfs_dentry) {
	610	inode = devices_usbfs_dentry->d_inode;
	611	if (inode)
	612	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	613	}
	614	}
	615
54a5c4cd	616	static void usbfs_add_bus(struct usb_bus *bus)
1da177e4 LT	617	{
	618	struct dentry *parent;
	619	char name[8];
	620	int retval;
	621
	622	/* create the special files if this is the first bus added */
	623	if (num_buses == 0) {
	624	retval = create_special_files();
	625	if (retval)
	626	return;
	627	}
	628	++num_buses;
	629
	630	sprintf (name, "%03d", bus->busnum);
	631
	632	parent = usbfs_mount->mnt_sb->s_root;
	633	bus->usbfs_dentry = fs_create_file (name, busmode \| S_IFDIR, parent,
	634	bus, NULL, busuid, busgid);
	635	if (bus->usbfs_dentry == NULL) {
	636	err ("error creating usbfs bus entry");
	637	return;
	638	}
1da177e4 LT	639	}
1da177e4 LT	640
54a5c4cd	641	static void usbfs_remove_bus(struct usb_bus *bus)
1da177e4 LT	642	{
	643	if (bus->usbfs_dentry) {
	644	fs_remove_file (bus->usbfs_dentry);
	645	bus->usbfs_dentry = NULL;
	646	}
	647
	648	--num_buses;
	649	if (num_buses <= 0) {
	650	remove_special_files();
	651	num_buses = 0;
	652	}
1da177e4 LT	653	}
1da177e4 LT	654
54a5c4cd	655	static void usbfs_add_device(struct usb_device *dev)
1da177e4 LT	656	{
	657	char name[8];
	658	int i;
	659	int i_size;
	660
	661	sprintf (name, "%03d", dev->devnum);
	662	dev->usbfs_dentry = fs_create_file (name, devmode \| S_IFREG,
	663	dev->bus->usbfs_dentry, dev,
9f8b17e6	664	&usbdev_file_operations,
1da177e4 LT	665	devuid, devgid);
	666	if (dev->usbfs_dentry == NULL) {
	667	err ("error creating usbfs device entry");
	668	return;
	669	}
	670
	671	/* Set the size of the device's file to be
	672	* equal to the size of the device descriptors. */
	673	i_size = sizeof (struct usb_device_descriptor);
	674	for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
	675	struct usb_config_descriptor *config =
	676	(struct usb_config_descriptor *)dev->rawdescriptors[i];
	677	i_size += le16_to_cpu(config->wTotalLength);
	678	}
	679	if (dev->usbfs_dentry->d_inode)
	680	dev->usbfs_dentry->d_inode->i_size = i_size;
1da177e4 LT	681	}
1da177e4 LT	682
54a5c4cd	683	static void usbfs_remove_device(struct usb_device *dev)
1da177e4 LT	684	{
	685	struct dev_state *ds;
	686	struct siginfo sinfo;
	687
	688	if (dev->usbfs_dentry) {
	689	fs_remove_file (dev->usbfs_dentry);
	690	dev->usbfs_dentry = NULL;
	691	}
	692	while (!list_empty(&dev->filelist)) {
	693	ds = list_entry(dev->filelist.next, struct dev_state, list);
	694	wake_up_all(&ds->wait);
	695	list_del_init(&ds->list);
	696	if (ds->discsignr) {
58a5b0a6	697	sinfo.si_signo = ds->discsignr;
1da177e4 LT	698	sinfo.si_errno = EPIPE;
	699	sinfo.si_code = SI_ASYNCIO;
	700	sinfo.si_addr = ds->disccontext;
2425c08b	701	kill_pid_info_as_uid(ds->discsignr, &sinfo, ds->disc_pid, ds->disc_uid, ds->disc_euid, ds->secid);
1da177e4 LT	702	}
1da177e4 LT	703	}
54a5c4cd GKH	704	}
	705
	706	static int usbfs_notify(struct notifier_block self, unsigned long action, void dev)
	707	{
	708	switch (action) {
	709	case USB_DEVICE_ADD:
	710	usbfs_add_device(dev);
	711	break;
	712	case USB_DEVICE_REMOVE:
	713	usbfs_remove_device(dev);
	714	break;
	715	case USB_BUS_ADD:
	716	usbfs_add_bus(dev);
	717	break;
	718	case USB_BUS_REMOVE:
	719	usbfs_remove_bus(dev);
	720	}
	721
1da177e4 LT	722	usbfs_update_special();
1da177e4 LT	723	usbfs_conn_disc_event();
54a5c4cd	724	return NOTIFY_OK;
1da177e4 LT	725	}
1da177e4 LT	726
54a5c4cd GKH	727	static struct notifier_block usbfs_nb = {
	728	.notifier_call = usbfs_notify,
	729	};
	730
1da177e4 LT	731	/* --------------------------------------------------------------------- */
	732
	733	static struct proc_dir_entry *usbdir = NULL;
	734
	735	int __init usbfs_init(void)
	736	{
	737	int retval;
	738
1da177e4	739	retval = register_filesystem(&usb_fs_type);
fbf82fd2	740	if (retval)
1da177e4	741	return retval;
1da177e4	742
54a5c4cd GKH	743	usb_register_notify(&usbfs_nb);
54a5c4cd GKH	744
1da177e4 LT	745	/* create mount point for usbfs */
	746	usbdir = proc_mkdir("usb", proc_bus);
	747
	748	return 0;
	749	}
	750
	751	void usbfs_cleanup(void)
	752	{
54a5c4cd	753	usb_unregister_notify(&usbfs_nb);
1da177e4 LT	754	unregister_filesystem(&usb_fs_type);
	755	if (usbdir)
	756	remove_proc_entry("usb", proc_bus);
	757	}
	758