linux/drivers/usb/core/inode.c

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/*****************************************************************************/
/*
* 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 <linux/seq_file.h>
#include <linux/smp_lock.h>
#include <asm/byteorder.h>
#include "usb.h"
#include "hcd.h"
#define USBFS_DEFAULT_DEVMODE (S_IWUSR | S_IRUGO)
#define USBFS_DEFAULT_BUSMODE (S_IXUGO | S_IRUGO)
#define USBFS_DEFAULT_LISTMODE S_IRUGO
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 = USBFS_DEFAULT_DEVMODE;
static umode_t busmode = USBFS_DEFAULT_BUSMODE;
static umode_t listmode = USBFS_DEFAULT_LISTMODE;
static int usbfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
{
if (devuid != 0)
seq_printf(seq, ",devuid=%u", devuid);
if (devgid != 0)
seq_printf(seq, ",devgid=%u", devgid);
if (devmode != USBFS_DEFAULT_DEVMODE)
seq_printf(seq, ",devmode=%o", devmode);
if (busuid != 0)
seq_printf(seq, ",busuid=%u", busuid);
if (busgid != 0)
seq_printf(seq, ",busgid=%u", busgid);
if (busmode != USBFS_DEFAULT_BUSMODE)
seq_printf(seq, ",busmode=%o", busmode);
if (listuid != 0)
seq_printf(seq, ",listuid=%u", listuid);
if (listgid != 0)
seq_printf(seq, ",listgid=%u", listgid);
if (listmode != USBFS_DEFAULT_LISTMODE)
seq_printf(seq, ",listmode=%o", listmode);
return 0;
}
enum {
Opt_devuid, Opt_devgid, Opt_devmode,
Opt_busuid, Opt_busgid, Opt_busmode,
Opt_listuid, Opt_listgid, Opt_listmode,
Opt_err,
};
static const 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 = USBFS_DEFAULT_DEVMODE;
busmode = USBFS_DEFAULT_BUSMODE;
listmode = USBFS_DEFAULT_LISTMODE;
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:
printk(KERN_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);
[PATCH] shrink dentry struct Some long time ago, dentry struct was carefully tuned so that on 32 bits UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple of memory cache lines. Then RCU was added and dentry struct enlarged by two pointers, with nice results for SMP, but not so good on UP, because breaking the above tuning (128 + 8 = 136 bytes) This patch reverts this unwanted side effect, by using an union (d_u), where d_rcu and d_child are placed so that these two fields can share their memory needs. At the time d_free() is called (and d_rcu is really used), d_child is known to be empty and not touched by the dentry freeing. Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so the previous content of d_child is not needed if said dentry was unhashed but still accessed by a CPU because of RCU constraints) As dentry cache easily contains millions of entries, a size reduction is worth the extra complexity of the ugly C union. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Maneesh Soni <maneesh@in.ibm.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Ian Kent <raven@themaw.net> Cc: Paul Jackson <pj@sgi.com> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Neil Brown <neilb@cse.unsw.edu.au> Cc: James Morris <jmorris@namei.org> Cc: Stephen Smalley <sds@epoch.ncsc.mil> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 09:03:32 +00:00
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);
[PATCH] shrink dentry struct Some long time ago, dentry struct was carefully tuned so that on 32 bits UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple of memory cache lines. Then RCU was added and dentry struct enlarged by two pointers, with nice results for SMP, but not so good on UP, because breaking the above tuning (128 + 8 = 136 bytes) This patch reverts this unwanted side effect, by using an union (d_u), where d_rcu and d_child are placed so that these two fields can share their memory needs. At the time d_free() is called (and d_rcu is really used), d_child is known to be empty and not touched by the dentry freeing. Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so the previous content of d_child is not needed if said dentry was unhashed but still accessed by a CPU because of RCU constraints) As dentry cache easily contains millions of entries, a size reduction is worth the extra complexity of the ugly C union. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Maneesh Soni <maneesh@in.ibm.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Ian Kent <raven@themaw.net> Cc: Paul Jackson <pj@sgi.com> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Neil Brown <neilb@cse.unsw.edu.au> Cc: James Morris <jmorris@namei.org> Cc: Stephen Smalley <sds@epoch.ncsc.mil> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 09:03:32 +00:00
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:
printk(KERN_WARNING "usbfs: 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)) {
printk(KERN_WARNING "usbfs: mount parameter error.\n");
return -EINVAL;
}
lock_kernel();
if (usbfs_mount && usbfs_mount->mnt_sb)
update_sb(usbfs_mount->mnt_sb);
unlock_kernel();
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_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) {
[PATCH] shrink dentry struct Some long time ago, dentry struct was carefully tuned so that on 32 bits UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple of memory cache lines. Then RCU was added and dentry struct enlarged by two pointers, with nice results for SMP, but not so good on UP, because breaking the above tuning (128 + 8 = 136 bytes) This patch reverts this unwanted side effect, by using an union (d_u), where d_rcu and d_child are placed so that these two fields can share their memory needs. At the time d_free() is called (and d_rcu is really used), d_child is known to be empty and not touched by the dentry freeing. Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so the previous content of d_child is not needed if said dentry was unhashed but still accessed by a CPU because of RCU constraints) As dentry cache easily contains millions of entries, a size reduction is worth the extra complexity of the ugly C union. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Maneesh Soni <maneesh@in.ibm.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Ian Kent <raven@themaw.net> Cc: Paul Jackson <pj@sgi.com> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Neil Brown <neilb@cse.unsw.edu.au> Cc: James Morris <jmorris@namei.org> Cc: Stephen Smalley <sds@epoch.ncsc.mil> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 09:03:32 +00:00
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 const struct super_operations usbfs_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
.remount_fs = remount,
.show_options = usbfs_show_options,
};
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!",__func__);
return -ENOMEM;
}
root = d_alloc_root(inode);
if (!root) {
dbg("%s: could not get root dentry!",__func__);
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);
}
/* --------------------------------------------------------------------- */
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:57 +00:00
static int usb_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:57 +00:00
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) {
printk(KERN_ERR "Unable to get usbfs mount\n");
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) {
printk(KERN_ERR "Unable to create devices usbfs file\n");
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) {
printk(KERN_ERR "Error creating usbfs bus entry\n");
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,
USB: make usbdevices export their device nodes instead of using a separate class o The "real" usb-devices export now a device node which can populate /dev/bus/usb. o The usb_device class is optional now and can be disabled in the kernel config. Major/minor of the "real" devices and class devices are the same. o The environment of the usb-device event contains DEVNUM and BUSNUM to help udev and get rid of the ugly udev rule we need for the class devices. o The usb-devices and usb-interfaces share the same bus, so I used the new "struct device_type" to let these devices identify themselves. This also removes the current logic of using a magic platform-pointer. The name of the device_type is also added to the environment which makes it easier to distinguish the different kinds of devices on the same subsystem. It looks like this: add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1 ACTION=add DEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2-1 SUBSYSTEM=usb SEQNUM=1533 MAJOR=189 MINOR=131 DEVTYPE=usb_device PRODUCT=46d/c03e/2000 TYPE=0/0/0 BUSNUM=002 DEVNUM=004 This udev rule works as a replacement for usb_device class devices: SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \ NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644" Updated patch, which needs the device_type patches in Greg's tree. I also got a bugzilla assigned for this. :) https://bugzilla.novell.com/show_bug.cgi?id=250659 Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-03-13 14:59:31 +00:00
&usbdev_file_operations,
devuid, devgid);
if (dev->usbfs_dentry == NULL) {
printk(KERN_ERR "Error creating usbfs device entry\n");
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)
{
if (dev->usbfs_dentry) {
fs_remove_file (dev->usbfs_dentry);
dev->usbfs_dentry = NULL;
}
}
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);
[PATCH] USB: real nodes instead of usbfs This patch introduces a /sys/class/usb_device/ class where every connected usb-device will show up: tree /sys/class/usb_device/ /sys/class/usb_device/ |-- usb1.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.0/usb1 |-- usb2.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.1/usb2 ... The presence of the "dev" file lets udev create real device nodes. kay@pim:~/src/linux-2.6> tree /dev/bus/usb/ /dev/bus/usb/ |-- 1 | `-- 1 |-- 2 | `-- 1 ... udev rule: SUBSYSTEM="usb_device", PROGRAM="/sbin/usb_device %k", NAME="%c" (echo $1 | /bin/sed 's/usb\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/') This makes libusb pick up the real nodes instead of the mounted usbfs: export USB_DEVFS_PATH=/dev/bus/usb Background: All this makes it possible to manage usb devices with udev instead of the devfs solution. We are currently working on a pam_console/resmgr replacement driven by udev and a pam-helper. It applies ACL's to device nodes, which is required for modern desktop functionalty like "Fast User Switching" or multiple local login support. New patch with its own major. I've succesfully disabled usbfs and use real nodes only on my box. With: "export USB_DEVFS_PATH=/dev/bus/usb" libusb picks up the udev managed nodes instead of reading usbfs files. This makes udev to provide symlinks for libusb to pick up: SUBSYSTEM="usb_device", PROGRAM="/sbin/usbdevice %k", SYMLINK="%c" /sbin/usbdevice: #!/bin/sh echo $1 | /bin/sed 's/usbdev\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/' Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-07-30 23:05:53 +00:00
if (retval)
return retval;
usb_register_notify(&usbfs_nb);
/* create mount point for usbfs */
usbdir = proc_mkdir("bus/usb", NULL);
return 0;
}
void usbfs_cleanup(void)
{
usb_unregister_notify(&usbfs_nb);
unregister_filesystem(&usb_fs_type);
if (usbdir)
remove_proc_entry("bus/usb", NULL);
}