[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/config.h>
#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/smp_lock.h>
#include <linux/parser.h>
#include <asm/byteorder.h>
#include "usb.h"
#include "hcd.h"

static struct super_operations usbfs_ops;
static struct file_operations default_file_operations;
static struct inode_operations usbfs_dir_inode_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;

	down(&bus->d_inode->i_sem);

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

	up(&bus->d_inode->i_sem);
}

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

	if (!root)
		return;

	down(&root->d_inode->i_sem);

	list_for_each_entry(bus, &root->d_subdirs, 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;
			}
		}
	}

	up(&root->d_inode->i_sem);
}

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_blksize = PAGE_CACHE_SIZE;
		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 = &usbfs_dir_inode_operations;
			inode->i_fop = &simple_dir_operations;

			/* directory inodes start off with i_nlink == 2 (for "." entry) */
			inode->i_nlink++;
			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)
		dir->i_nlink++;
	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_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;
	down(&inode->i_sem);
	dentry->d_inode->i_nlink--;
	dput(dentry);
	up(&inode->i_sem);
	d_delete(dentry);
	return 0;
}

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

	down(&inode->i_sem);
	dentry_unhash(dentry);
	if (usbfs_empty(dentry)) {
		dentry->d_inode->i_nlink -= 2;
		dput(dentry);
		inode->i_flags |= S_DEAD;
		dir->i_nlink--;
		error = 0;
	}
	up(&inode->i_sem);
	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;

	down(&file->f_dentry->d_inode->i_sem);
	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;
	}
	up(&file->f_dentry->d_inode->i_sem);
	return retval;
}

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

	return 0;
}

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

static struct inode_operations usbfs_dir_inode_operations = {
	.lookup =	simple_lookup,
};

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;
}

static struct dentry * get_dentry(struct dentry *parent, const char *name)
{               
	struct qstr qstr;

	qstr.name = name;
	qstr.len = strlen(name);
	qstr.hash = full_name_hash(name,qstr.len);
	return lookup_hash(&qstr,parent);
}               


/*
 * 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;
	down(&parent->d_inode->i_sem);
	*dentry = get_dentry (parent, 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);
	up(&parent->d_inode->i_sem);

	return error;
}

static struct dentry *fs_create_file (const char *name, mode_t mode,
				      struct dentry *parent, void *data,
				      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->u.generic_ip = 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;

	down(&parent->d_inode->i_sem);
	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);
		}
	}
	up(&parent->d_inode->i_sem);
}

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

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

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("usbfs", &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;
	}
}

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;
	}

	usbfs_update_special();
	usbfs_conn_disc_event();
}

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;
	}

	usbfs_update_special();
	usbfs_conn_disc_event();
}

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,
					    &usbfs_device_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;

	usbfs_update_special();
	usbfs_conn_disc_event();
}

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 = SIGPIPE;
			sinfo.si_errno = EPIPE;
			sinfo.si_code = SI_ASYNCIO;
			sinfo.si_addr = ds->disccontext;
			send_sig_info(ds->discsignr, &sinfo, ds->disctask);
		}
	}
	usbfs_update_special();
	usbfs_conn_disc_event();
}

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

static struct proc_dir_entry *usbdir = NULL;

int __init usbfs_init(void)
{
	int retval;

	retval = usb_register(&usbfs_driver);
	if (retval)
		return retval;

	retval = register_filesystem(&usb_fs_type);
	if (retval) {
		usb_deregister(&usbfs_driver);
		return retval;
	}

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

	return 0;
}

void usbfs_cleanup(void)
{
	usb_deregister(&usbfs_driver);
	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
	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"
6d5e8254	44	#include "hcd.h"
1da177e4 LT	45
	46	static struct super_operations usbfs_ops;
	47	static struct file_operations default_file_operations;
	48	static struct inode_operations usbfs_dir_inode_operations;
	49	static struct vfsmount *usbfs_mount;
	50	static int usbfs_mount_count; /* = 0 */
	51	static int ignore_mount = 0;
	52
	53	static struct dentry *devices_usbfs_dentry;
	54	static int num_buses; /* = 0 */
	55
	56	static uid_t devuid; /* = 0 */
	57	static uid_t busuid; /* = 0 */
	58	static uid_t listuid; /* = 0 */
	59	static gid_t devgid; /* = 0 */
	60	static gid_t busgid; /* = 0 */
	61	static gid_t listgid; /* = 0 */
	62	static umode_t devmode = S_IWUSR \| S_IRUGO;
	63	static umode_t busmode = S_IXUGO \| S_IRUGO;
	64	static umode_t listmode = S_IRUGO;
	65
	66	enum {
	67	Opt_devuid, Opt_devgid, Opt_devmode,
	68	Opt_busuid, Opt_busgid, Opt_busmode,
	69	Opt_listuid, Opt_listgid, Opt_listmode,
	70	Opt_err,
	71	};
	72
	73	static match_table_t tokens = {
	74	{Opt_devuid, "devuid=%u"},
	75	{Opt_devgid, "devgid=%u"},
	76	{Opt_devmode, "devmode=%o"},
	77	{Opt_busuid, "busuid=%u"},
	78	{Opt_busgid, "busgid=%u"},
	79	{Opt_busmode, "busmode=%o"},
	80	{Opt_listuid, "listuid=%u"},
	81	{Opt_listgid, "listgid=%u"},
	82	{Opt_listmode, "listmode=%o"},
	83	{Opt_err, NULL}
	84	};
	85
	86	static int parse_options(struct super_block s, char data)
	87	{
	88	char *p;
	89	int option;
	90
	91	/* (re)set to defaults. */
	92	devuid = 0;
	93	busuid = 0;
	94	listuid = 0;
	95	devgid = 0;
	96	busgid = 0;
	97	listgid = 0;
	98	devmode = S_IWUSR \| S_IRUGO;
	99	busmode = S_IXUGO \| S_IRUGO;
	100	listmode = S_IRUGO;
	101
	102	while ((p = strsep(&data, ",")) != NULL) {
	103	substring_t args[MAX_OPT_ARGS];
	104	int token;
	105	if (!*p)
	106	continue;
	107
	108	token = match_token(p, tokens, args);
109	switch (token) {
110	case Opt_devuid:
111	if (match_int(&args[0], &option))
112	return -EINVAL;
113	devuid = option;
114	break;
115	case Opt_devgid:
116	if (match_int(&args[0], &option))
117	return -EINVAL;
118	devgid = option;
119	break;
120	case Opt_devmode:
121	if (match_octal(&args[0], &option))
122	return -EINVAL;
123	devmode = option & S_IRWXUGO;
124	break;
125	case Opt_busuid:
126	if (match_int(&args[0], &option))
127	return -EINVAL;
128	busuid = option;
129	break;
130	case Opt_busgid:
131	if (match_int(&args[0], &option))
132	return -EINVAL;
133	busgid = option;
134	break;
135	case Opt_busmode:
136	if (match_octal(&args[0], &option))
137	return -EINVAL;
138	busmode = option & S_IRWXUGO;
139	break;
140	case Opt_listuid:
141	if (match_int(&args[0], &option))
142	return -EINVAL;
143	listuid = option;
144	break;
145	case Opt_listgid:
146	if (match_int(&args[0], &option))
147	return -EINVAL;
148	listgid = option;
149	break;
150	case Opt_listmode:
151	if (match_octal(&args[0], &option))
152	return -EINVAL;
153	listmode = option & S_IRWXUGO;
154	break;
155	default:
156	err("usbfs: unrecognised mount option \"%s\" "
157	"or missing value\n", p);
158	return -EINVAL;
159	}
160	}
161
162	return 0;
163	}
164
165	static void update_special(struct dentry *special)
166	{
167	special->d_inode->i_uid = listuid;
168	special->d_inode->i_gid = listgid;
169	special->d_inode->i_mode = S_IFREG \| listmode;
170	}
171
172	static void update_dev(struct dentry *dev)
173	{
174	dev->d_inode->i_uid = devuid;
175	dev->d_inode->i_gid = devgid;
176	dev->d_inode->i_mode = S_IFREG \| devmode;
177	}
178
179	static void update_bus(struct dentry *bus)
180	{
181	struct dentry *dev = NULL;
182
183	bus->d_inode->i_uid = busuid;
184	bus->d_inode->i_gid = busgid;
185	bus->d_inode->i_mode = S_IFDIR \| busmode;
186
187	down(&bus->d_inode->i_sem);
188
189	list_for_each_entry(dev, &bus->d_subdirs, d_child)
190	if (dev->d_inode)
191	update_dev(dev);
192
193	up(&bus->d_inode->i_sem);
194	}
195
196	static void update_sb(struct super_block *sb)
197	{
198	struct dentry *root = sb->s_root;
199	struct dentry *bus = NULL;
200
201	if (!root)
202	return;
203
204	down(&root->d_inode->i_sem);
205
206	list_for_each_entry(bus, &root->d_subdirs, d_child) {
207	if (bus->d_inode) {
208	switch (S_IFMT & bus->d_inode->i_mode) {
209	case S_IFDIR:
210	update_bus(bus);
211	break;
212	case S_IFREG:
213	update_special(bus);
214	break;
215	default:
216	warn("Unknown node %s mode %x found on remount!\n",bus->d_name.name,bus->d_inode->i_mode);
217	break;
218	}
219	}
220	}
221
222	up(&root->d_inode->i_sem);
223	}
224
225	static int remount(struct super_block sb, int flags, char *data)
226	{
227	/* If this is not a real mount,
228	* i.e. it's a simple_pin_fs from create_special_files,
229	* then ignore it.
230	*/
231	if (ignore_mount)
232	return 0;
233
234	if (parse_options(sb, data)) {
235	warn("usbfs: mount parameter error:");
236	return -EINVAL;
237	}
238
239	if (usbfs_mount && usbfs_mount->mnt_sb)
240	update_sb(usbfs_mount->mnt_sb);
241
242	return 0;
243	}
244
245	static struct inode usbfs_get_inode (struct super_block sb, int mode, dev_t dev)
246	{
247	struct inode *inode = new_inode(sb);
248
249	if (inode) {
250	inode->i_mode = mode;
251	inode->i_uid = current->fsuid;
252	inode->i_gid = current->fsgid;
253	inode->i_blksize = PAGE_CACHE_SIZE;
254	inode->i_blocks = 0;
255	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
256	switch (mode & S_IFMT) {
257	default:
258	init_special_inode(inode, mode, dev);
259	break;
260	case S_IFREG:
261	inode->i_fop = &default_file_operations;
262	break;
263	case S_IFDIR:
264	inode->i_op = &usbfs_dir_inode_operations;
265	inode->i_fop = &simple_dir_operations;
266
267	/* directory inodes start off with i_nlink == 2 (for "." entry) */
268	inode->i_nlink++;
269	break;
270	}
271	}
272	return inode;
273	}
274
275	/* SMP-safe */
276	static int usbfs_mknod (struct inode dir, struct dentry dentry, int mode,
277	dev_t dev)
278	{
279	struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
280	int error = -EPERM;
281
282	if (dentry->d_inode)
283	return -EEXIST;
284
285	if (inode) {
286	d_instantiate(dentry, inode);
287	dget(dentry);
288	error = 0;
289	}
290	return error;
291	}
292
293	static int usbfs_mkdir (struct inode dir, struct dentry dentry, int mode)
294	{
295	int res;
296
297	mode = (mode & (S_IRWXUGO \| S_ISVTX)) \| S_IFDIR;
298	res = usbfs_mknod (dir, dentry, mode, 0);
299	if (!res)
300	dir->i_nlink++;
301	return res;
302	}
303
304	static int usbfs_create (struct inode dir, struct dentry dentry, int mode)
305	{
306	mode = (mode & S_IALLUGO) \| S_IFREG;
307	return usbfs_mknod (dir, dentry, mode, 0);
308	}
309
310	static inline int usbfs_positive (struct dentry *dentry)
311	{
312	return dentry->d_inode && !d_unhashed(dentry);
313	}
314
315	static int usbfs_empty (struct dentry *dentry)
316	{
317	struct list_head *list;
318
319	spin_lock(&dcache_lock);
320
321	list_for_each(list, &dentry->d_subdirs) {
322	struct dentry *de = list_entry(list, struct dentry, d_child);
323	if (usbfs_positive(de)) {
324	spin_unlock(&dcache_lock);
325	return 0;
326	}
327	}
328
329	spin_unlock(&dcache_lock);
330	return 1;
331	}
332
333	static int usbfs_unlink (struct inode dir, struct dentry dentry)
334	{
335	struct inode *inode = dentry->d_inode;
336	down(&inode->i_sem);
337	dentry->d_inode->i_nlink--;
338	dput(dentry);
339	up(&inode->i_sem);
340	d_delete(dentry);
341	return 0;
342	}
343
344	static int usbfs_rmdir(struct inode dir, struct dentry dentry)
345	{
346	int error = -ENOTEMPTY;
347	struct inode * inode = dentry->d_inode;
348
349	down(&inode->i_sem);
350	dentry_unhash(dentry);
351	if (usbfs_empty(dentry)) {
352	dentry->d_inode->i_nlink -= 2;
353	dput(dentry);
354	inode->i_flags \|= S_DEAD;
355	dir->i_nlink--;
356	error = 0;
357	}
358	up(&inode->i_sem);
359	if (!error)
360	d_delete(dentry);
361	dput(dentry);
362	return error;
363	}
364
365
366	/* default file operations */
367	static ssize_t default_read_file (struct file file, char __user buf,
368	size_t count, loff_t *ppos)
369	{
370	return 0;
371	}
372
373	static ssize_t default_write_file (struct file file, const char __user buf,
374	size_t count, loff_t *ppos)
375	{
376	return count;
377	}
378
379	static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
380	{
381	loff_t retval = -EINVAL;
382
383	down(&file->f_dentry->d_inode->i_sem);
384	switch(orig) {
385	case 0:
386	if (offset > 0) {
387	file->f_pos = offset;
388	retval = file->f_pos;
389	}
390	break;
391	case 1:
392	if ((offset + file->f_pos) > 0) {
393	file->f_pos += offset;
394	retval = file->f_pos;
395	}
396	break;
397	default:
398	break;
399	}
400	up(&file->f_dentry->d_inode->i_sem);
401	return retval;
402	}
403
404	static int default_open (struct inode inode, struct file file)
405	{
406	if (inode->u.generic_ip)
407	file->private_data = inode->u.generic_ip;
408
409	return 0;
410	}
411
412	static struct file_operations default_file_operations = {
413	.read = default_read_file,
414	.write = default_write_file,
415	.open = default_open,
416	.llseek = default_file_lseek,
417	};
418
419	static struct inode_operations usbfs_dir_inode_operations = {
420	.lookup = simple_lookup,
421	};
422
423	static struct super_operations usbfs_ops = {
424	.statfs = simple_statfs,
425	.drop_inode = generic_delete_inode,
426	.remount_fs = remount,
427	};
428
429	static int usbfs_fill_super(struct super_block sb, void data, int silent)
430	{
431	struct inode *inode;
432	struct dentry *root;
433
434	sb->s_blocksize = PAGE_CACHE_SIZE;
435	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
436	sb->s_magic = USBDEVICE_SUPER_MAGIC;
437	sb->s_op = &usbfs_ops;
438	sb->s_time_gran = 1;
439	inode = usbfs_get_inode(sb, S_IFDIR \| 0755, 0);
440
441	if (!inode) {
442	dbg("%s: could not get inode!",__FUNCTION__);
443	return -ENOMEM;
444	}
445
446	root = d_alloc_root(inode);
447	if (!root) {
448	dbg("%s: could not get root dentry!",__FUNCTION__);
449	iput(inode);
450	return -ENOMEM;
451	}
452	sb->s_root = root;
453	return 0;
454	}
455
456	static struct dentry * get_dentry(struct dentry parent, const char name)
457	{
458	struct qstr qstr;
459
460	qstr.name = name;
461	qstr.len = strlen(name);
462	qstr.hash = full_name_hash(name,qstr.len);
463	return lookup_hash(&qstr,parent);
464	}
465
466
467	/*
468	* fs_create_by_name - create a file, given a name
469	* @name: name of file
470	* @mode: type of file
471	* @parent: dentry of directory to create it in
472	* @dentry: resulting dentry of file
473	*
474	* This function handles both regular files and directories.
475	*/
476	static int fs_create_by_name (const char *name, mode_t mode,
477	struct dentry parent, struct dentry *dentry)
478	{
479	int error = 0;
480
481	/* If the parent is not specified, we create it in the root.
482	* We need the root dentry to do this, which is in the super
483	* block. A pointer to that is in the struct vfsmount that we
484	* have around.
485	*/
486	if (!parent ) {
487	if (usbfs_mount && usbfs_mount->mnt_sb) {
488	parent = usbfs_mount->mnt_sb->s_root;
489	}
490	}
491
492	if (!parent) {
493	dbg("Ah! can not find a parent!");
494	return -EFAULT;
495	}
496
497	*dentry = NULL;
498	down(&parent->d_inode->i_sem);
499	*dentry = get_dentry (parent, name);
500	if (!IS_ERR(dentry)) {
501	if ((mode & S_IFMT) == S_IFDIR)
502	error = usbfs_mkdir (parent->d_inode, *dentry, mode);
503	else
504	error = usbfs_create (parent->d_inode, *dentry, mode);
505	} else
506	error = PTR_ERR(dentry);
507	up(&parent->d_inode->i_sem);
508
509	return error;
510	}
511
512	static struct dentry fs_create_file (const char name, mode_t mode,
513	struct dentry parent, void data,
514	struct file_operations *fops,
515	uid_t uid, gid_t gid)
516	{
517	struct dentry *dentry;
518	int error;
519
520	dbg("creating file '%s'",name);
521
522	error = fs_create_by_name (name, mode, parent, &dentry);
523	if (error) {
524	dentry = NULL;
525	} else {
526	if (dentry->d_inode) {
527	if (data)
528	dentry->d_inode->u.generic_ip = data;
529	if (fops)
530	dentry->d_inode->i_fop = fops;
531	dentry->d_inode->i_uid = uid;
532	dentry->d_inode->i_gid = gid;
533	}
534	}
535
536	return dentry;
537	}
538
539	static void fs_remove_file (struct dentry *dentry)
540	{
541	struct dentry *parent = dentry->d_parent;
542
543	if (!parent \|\| !parent->d_inode)
544	return;
545
546	down(&parent->d_inode->i_sem);
547	if (usbfs_positive(dentry)) {
548	if (dentry->d_inode) {
549	if (S_ISDIR(dentry->d_inode->i_mode))
550	usbfs_rmdir(parent->d_inode, dentry);
551	else
552	usbfs_unlink(parent->d_inode, dentry);
553	dput(dentry);
554	}
555	}
556	up(&parent->d_inode->i_sem);
557	}
558
559	/* --------------------------------------------------------------------- */
560
561	static struct super_block usb_get_sb(struct file_system_type fs_type,
562	int flags, const char dev_name, void data)
563	{
564	return get_sb_single(fs_type, flags, data, usbfs_fill_super);
565	}
566
567	static struct file_system_type usb_fs_type = {
568	.owner = THIS_MODULE,
569	.name = "usbfs",
570	.get_sb = usb_get_sb,
571	.kill_sb = kill_litter_super,
572	};
573
574	/* --------------------------------------------------------------------- */
575
576	static int create_special_files (void)
577	{
578	struct dentry *parent;
579	int retval;
580
581	/* the simple_pin_fs calls will call remount with no options
582	* without this flag that would overwrite the real mount options (if any)
583	*/
584	ignore_mount = 1;
585
586	/* create the devices special file */
587	retval = simple_pin_fs("usbfs", &usbfs_mount, &usbfs_mount_count);
588	if (retval) {
589	err ("Unable to get usbfs mount");
590	goto exit;
591	}
592
593	ignore_mount = 0;
594
595	parent = usbfs_mount->mnt_sb->s_root;
596	devices_usbfs_dentry = fs_create_file ("devices",
597	listmode \| S_IFREG, parent,
598	NULL, &usbfs_devices_fops,
599	listuid, listgid);
600	if (devices_usbfs_dentry == NULL) {
601	err ("Unable to create devices usbfs file");
602	retval = -ENODEV;
603	goto error_clean_mounts;
604	}
605
606	goto exit;
607
608	error_clean_mounts:
609	simple_release_fs(&usbfs_mount, &usbfs_mount_count);
610	exit:
611	return retval;
612	}
613
614	static void remove_special_files (void)
615	{
616	if (devices_usbfs_dentry)
617	fs_remove_file (devices_usbfs_dentry);
618	devices_usbfs_dentry = NULL;
619	simple_release_fs(&usbfs_mount, &usbfs_mount_count);
620	}
621
622	void usbfs_update_special (void)
623	{
624	struct inode *inode;
625
626	if (devices_usbfs_dentry) {
627	inode = devices_usbfs_dentry->d_inode;
628	if (inode)
629	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
630	}
631	}
632
633	void usbfs_add_bus(struct usb_bus *bus)
634	{
635	struct dentry *parent;
636	char name[8];
637	int retval;
638
639	/* create the special files if this is the first bus added */
640	if (num_buses == 0) {
641	retval = create_special_files();
642	if (retval)
643	return;
644	}
645	++num_buses;
646
647	sprintf (name, "%03d", bus->busnum);
648
649	parent = usbfs_mount->mnt_sb->s_root;
650	bus->usbfs_dentry = fs_create_file (name, busmode \| S_IFDIR, parent,
651	bus, NULL, busuid, busgid);
652	if (bus->usbfs_dentry == NULL) {
653	err ("error creating usbfs bus entry");
654	return;
655	}
656
657	usbfs_update_special();
658	usbfs_conn_disc_event();
659	}
660
661	void usbfs_remove_bus(struct usb_bus *bus)
662	{
663	if (bus->usbfs_dentry) {
664	fs_remove_file (bus->usbfs_dentry);
665	bus->usbfs_dentry = NULL;
666	}
667
668	--num_buses;
669	if (num_buses <= 0) {
670	remove_special_files();
671	num_buses = 0;
672	}
673
674	usbfs_update_special();
675	usbfs_conn_disc_event();
676	}
677
678	void usbfs_add_device(struct usb_device *dev)
679	{
680	char name[8];
681	int i;
682	int i_size;
683
684	sprintf (name, "%03d", dev->devnum);
685	dev->usbfs_dentry = fs_create_file (name, devmode \| S_IFREG,
686	dev->bus->usbfs_dentry, dev,
687	&usbfs_device_file_operations,
688	devuid, devgid);
689	if (dev->usbfs_dentry == NULL) {
690	err ("error creating usbfs device entry");
691	return;
692	}
693
694	/* Set the size of the device's file to be
695	* equal to the size of the device descriptors. */
696	i_size = sizeof (struct usb_device_descriptor);
697	for (i = 0; i < dev->descriptor.bNumConfigurations; ++i) {
698	struct usb_config_descriptor *config =
699	(struct usb_config_descriptor *)dev->rawdescriptors[i];
700	i_size += le16_to_cpu(config->wTotalLength);
701	}
702	if (dev->usbfs_dentry->d_inode)
703	dev->usbfs_dentry->d_inode->i_size = i_size;
704
705	usbfs_update_special();
706	usbfs_conn_disc_event();
707	}
708
709	void usbfs_remove_device(struct usb_device *dev)
710	{
711	struct dev_state *ds;
712	struct siginfo sinfo;
713
714	if (dev->usbfs_dentry) {
715	fs_remove_file (dev->usbfs_dentry);
716	dev->usbfs_dentry = NULL;
717	}
718	while (!list_empty(&dev->filelist)) {
719	ds = list_entry(dev->filelist.next, struct dev_state, list);
720	wake_up_all(&ds->wait);
721	list_del_init(&ds->list);
722	if (ds->discsignr) {
723	sinfo.si_signo = SIGPIPE;
724	sinfo.si_errno = EPIPE;
725	sinfo.si_code = SI_ASYNCIO;
726	sinfo.si_addr = ds->disccontext;
727	send_sig_info(ds->discsignr, &sinfo, ds->disctask);
728	}
729	}
730	usbfs_update_special();
731	usbfs_conn_disc_event();
732	}
733
734	/* --------------------------------------------------------------------- */
735
736	static struct proc_dir_entry *usbdir = NULL;
737
738	int __init usbfs_init(void)
739	{
740	int retval;
741
742	retval = usb_register(&usbfs_driver);
743	if (retval)
744	return retval;
745
746	retval = register_filesystem(&usb_fs_type);
747	if (retval) {
748	usb_deregister(&usbfs_driver);
749	return retval;
750	}
751
752	/* create mount point for usbfs */
753	usbdir = proc_mkdir("usb", proc_bus);
754
755	return 0;
756	}
757
758	void usbfs_cleanup(void)
759	{
760	usb_deregister(&usbfs_driver);
761	unregister_filesystem(&usb_fs_type);
762	if (usbdir)
763	remove_proc_entry("usb", proc_bus);
764	}
765