/*****************************************************************************/ /* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include "usb.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 dentry *root) { 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); 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: 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; } if (usbfs_mount) update_sb(usbfs_mount->mnt_sb); return 0; } static struct inode *usbfs_get_inode (struct super_block *sb, umode_t mode, dev_t dev) { struct inode *inode = new_inode(sb); if (inode) { inode->i_ino = get_next_ino(); inode_init_owner(inode, NULL, mode); 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, umode_t 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, umode_t 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, umode_t 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(&dentry->d_lock); list_for_each(list, &dentry->d_subdirs) { struct dentry *de = list_entry(list, struct dentry, d_u.d_child); spin_lock_nested(&de->d_lock, DENTRY_D_LOCK_NESTED); if (usbfs_positive(de)) { spin_unlock(&de->d_lock); spin_unlock(&dentry->d_lock); return 0; } spin_unlock(&de->d_lock); } spin_unlock(&dentry->d_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)) { dont_mount(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); 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); root = d_make_root(inode); if (!root) { dbg("%s: could not get root dentry!",__func__); 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, umode_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) parent = usbfs_mount->mnt_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 (S_ISDIR(mode)) 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, umode_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 struct dentry *usb_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { return mount_single(fs_type, flags, data, usbfs_fill_super); } static struct file_system_type usb_fs_type = { .owner = THIS_MODULE, .name = "usbfs", .mount = usb_mount, .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_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_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, &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); 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); }