USB: lots of usbfs updates

Now users can't create files within the fs.
Thanks to Pat Mochel <mochel@osdl.org> for the ideas on how to do this.

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index e80a3ed170f88247e9a12ea49495bf981fd29b79..db92cad55508e301785e7f69eaaf439d9b5e4360 100644 (file)
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -491,7 +491,7 @@ static int usbdev_open(struct inode *inode, struct file *file)
         */
        lock_kernel();
        ret = -ENOENT;
-       dev = inode->u.generic_ip;
+       dev = file->f_dentry->d_parent->d_fsdata;
        if (!dev)
                goto out;
        ret = -ENOMEM;

diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c
index ffb7e6e13284d2c3a8e4f22e687ccfef3856d90d..70335bc93a103e256ae082b12c7dc10925425f98 100644 (file)
--- a/drivers/usb/core/inode.c
+++ b/drivers/usb/core/inode.c
@@ -4,7 +4,7 @@
  *     inode.c  --  Inode/Dentry functions for the USB device file system.
  *
  *     Copyright (C) 2000 Thomas Sailer (sailer@ife.ee.ethz.ch)
- *     Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
+ *     Copyright (c) 2001,2002 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
@@ -176,7 +176,10 @@ static int usbfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
                        int dev)
 {
        struct inode *inode = usbfs_get_inode(dir->i_sb, mode, dev);
-       int error = -ENOSPC;
+       int error = -EPERM;
+
+       if (dentry->d_inode)
+               return -EEXIST;
 
        if (inode) {
                d_instantiate(dentry, inode);
@@ -188,12 +191,19 @@ static int usbfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
 
 static int usbfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
 {
-       return usbfs_mknod (dir, dentry, mode | S_IFDIR, 0);
+       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)
 {
-       return usbfs_mknod (dir, dentry, mode | S_IFREG, 0);
+       mode = (mode & S_IALLUGO) | S_IFREG;
+       return usbfs_mknod (dir, dentry, mode, 0);
 }
 
 static inline int usbfs_positive (struct dentry *dentry)
@@ -220,22 +230,54 @@ static int usbfs_empty (struct dentry *dentry)
 }
 
 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 void d_unhash(struct dentry *dentry)
+{
+       dget(dentry);
+       spin_lock(&dcache_lock);
+       switch (atomic_read(&dentry->d_count)) {
+       default:
+               spin_unlock(&dcache_lock);
+               shrink_dcache_parent(dentry);
+               spin_lock(&dcache_lock);
+               if (atomic_read(&dentry->d_count) != 2)
+                       break;
+       case 2:
+               list_del_init(&dentry->d_hash);
+       }
+       spin_unlock(&dcache_lock);
+}
+
+static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
 {
        int error = -ENOTEMPTY;
+       struct inode * inode = dentry->d_inode;
 
+       down(&inode->i_sem);
+       d_unhash(dentry);
        if (usbfs_empty(dentry)) {
-               struct inode *inode = dentry->d_inode;
-
-               lock_kernel();
-               inode->i_nlink--;
-               unlock_kernel();
+               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;
 }
 
-#define usbfs_rmdir usbfs_unlink
 
 /* default file operations */
 static ssize_t default_read_file (struct file *file, char *buf,
@@ -254,7 +296,7 @@ static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
 {
        loff_t retval = -EINVAL;
 
-       lock_kernel();
+       down(&file->f_dentry->d_inode->i_sem);
        switch(orig) {
        case 0:
                if (offset > 0) {
@@ -271,14 +313,18 @@ static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
        default:
                break;
        }
-       unlock_kernel();
+       up(&file->f_dentry->d_inode->i_sem);
        return retval;
 }
 
-static int default_open (struct inode *inode, struct file *filp)
+static int default_open (struct inode *inode, struct file *file)
 {
-       if (inode->u.generic_ip)
-               filp->private_data = inode->u.generic_ip;
+       void *data;
+
+       data = file->f_dentry->d_parent->d_fsdata;
+       if (!data)
+               return -EFAULT;
+       file->private_data = data;
 
        return 0;
 }
@@ -291,11 +337,7 @@ static struct file_operations default_file_operations = {
 };
 
 static struct inode_operations usbfs_dir_inode_operations = {
-       .create =       usbfs_create,
        .lookup =       simple_lookup,
-       .unlink =       usbfs_unlink,
-       .mkdir =        usbfs_mkdir,
-       .rmdir =        usbfs_rmdir,
 };
 
 static struct super_operations usbfs_ops = {
@@ -334,26 +376,32 @@ static int usbfs_fill_super(struct super_block *sb, void *data, int silent)
        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
+ * @data:      data to put in this dentry
  *
- * There is a bit of overhead in creating a file - basically, we 
- * have to hash the name of the file, then look it up. This will
- * prevent files of the same name. 
- * We then call the proper vfs_ function to take care of all the 
- * file creation details. 
  * 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)
+                             struct dentry *parent, struct dentry **dentry,
+                             void *data)
 {
-       struct dentry *d = NULL;
-       struct qstr qstr;
-       int error;
+       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 
@@ -372,34 +420,18 @@ static int fs_create_by_name (const char *name, mode_t mode,
        }
 
        *dentry = NULL;
-       qstr.name = name;
-       qstr.len = strlen(name);
-       qstr.hash = full_name_hash(name,qstr.len);
-
-       parent = dget(parent);
-
        down(&parent->d_inode->i_sem);
-
-       d = lookup_hash(&qstr,parent);
-
-       error = PTR_ERR(d);
-       if (!IS_ERR(d)) {
-               switch(mode & S_IFMT) {
-                       case 0: 
-                       case S_IFREG:
-                               error = vfs_create(parent->d_inode,d,mode);
-                               break;
-                       case S_IFDIR:
-                               error = vfs_mkdir(parent->d_inode,d,mode);
-                               break;
-                       default:
-                               err("cannot create special files");
-               }
-               *dentry = d;
-       }
+       *dentry = get_dentry (parent, name);
+       if (!IS_ERR(dentry)) {
+               (*dentry)->d_fsdata = data;
+               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);
 
-       dput(parent);
        return error;
 }
 
@@ -413,13 +445,11 @@ static struct dentry *fs_create_file (const char *name, mode_t mode,
 
        dbg("creating file '%s'",name);
 
-       error = fs_create_by_name(name,mode,parent,&dentry);
+       error = fs_create_by_name (name, mode, parent, &dentry, data);
        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;
@@ -441,12 +471,11 @@ static void fs_remove_file (struct dentry *dentry)
        if (usbfs_positive(dentry)) {
                if (dentry->d_inode) {
                        if (S_ISDIR(dentry->d_inode->i_mode))
-                               vfs_rmdir(parent->d_inode,dentry);
+                               usbfs_rmdir(parent->d_inode, dentry);
                        else
-                               vfs_unlink(parent->d_inode,dentry);
-               }
-
+                               usbfs_unlink(parent->d_inode, dentry);
                dput(dentry);
+               }
        }
        up(&parent->d_inode->i_sem);
 }
@@ -471,14 +500,14 @@ static struct file_system_type usbdevice_fs_type = {
        .owner =        THIS_MODULE,
        .name =         "usbdevfs",
        .get_sb =       usb_get_sb,
-       .kill_sb =      kill_anon_super,
+       .kill_sb =      kill_litter_super,
 };
 
 static struct file_system_type usb_fs_type = {
        .owner =        THIS_MODULE,
        .name =         "usbfs",
        .get_sb =       usb_get_sb,
-       .kill_sb =      kill_anon_super,
+       .kill_sb =      kill_litter_super,
 };
 
 /* --------------------------------------------------------------------- */
@@ -536,7 +565,7 @@ static int create_special_files (void)
 {
        int retval;
 
-       /* create the devices and drivers special files */
+       /* create the devices special file */
        retval = get_mount ();
        if (retval)
                return retval;