partially fix up the lookup_one_noperm mess

Index: linux-2.6/fs/namei.c
===================================================================
@@ -1273,7 +1273,8 @@ int __user_path_lookup_open(const char _
 	return err;
 }
 
-static inline struct dentry *__lookup_hash_kern(struct qstr *name, struct dentry *base, struct nameidata *nd)
+static struct dentry *__lookup_hash(struct qstr *name,
+		struct dentry *base, struct nameidata *nd)
 {
 	struct dentry *dentry;
 	struct inode *inode;

@@ -1313,31 +1314,18 @@ out:
  * needs parent already locked. Doesn't follow mounts.
  * SMP-safe.
  */
-static inline struct dentry * __lookup_hash(struct qstr *name, struct dentry *base, struct nameidata *nd)
+static struct dentry *lookup_hash(struct nameidata *nd)
 {
-	struct dentry *dentry;
-	struct inode *inode;
 	int err;
 
-	inode = base->d_inode;
-
-	err = permission(inode, MAY_EXEC, nd);
-	dentry = ERR_PTR(err);
+	err = permission(nd->dentry->d_inode, MAY_EXEC, nd);
 	if (err)
-		goto out;
-
-	dentry = __lookup_hash_kern(name, base, nd);
-out:
-	return dentry;
-}
-
-static struct dentry *lookup_hash(struct nameidata *nd)
-{
+		return ERR_PTR(err);
 	return __lookup_hash(&nd->last, nd->dentry, nd);
 }
 
-/* SMP-safe */
-static inline int __lookup_one_len(const char *name, struct qstr *this, struct dentry *base, int len)
+static int __lookup_one_len(const char *name, struct qstr *this,
+		struct dentry *base, int len)
 {
 	unsigned long hash;
 	unsigned int c;

@@ -1358,6 +1346,17 @@ static inline int __lookup_one_len(const
 	return 0;
 }
 
+/**
+ * lookup_one_len:  filesystem helper to lookup single pathname component
+ * @name:	pathname component to lookup
+ * @base:	base directory to lookup from
+ * @len:	maximum length @len should be interpreted to
+ *
+ * Note that this routine is purely a helper for filesystem useage and should
+ * not be called by generic code.  Also note that by using this function to
+ * nameidata argument is passed to the filesystem methods and a filesystem
+ * using this helper needs to be prepared for that.
+ */
 struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
 {
 	int err;

@@ -1366,18 +1365,33 @@ struct dentry *lookup_one_len(const char
 	err = __lookup_one_len(name, &this, base, len);
 	if (err)
 		return ERR_PTR(err);
+
+	err = permission(base->d_inode, MAY_EXEC, NULL);
+	if (err)
+		return ERR_PTR(err);
 	return __lookup_hash(&this, base, NULL);
 }
 
-struct dentry *lookup_one_len_kern(const char *name, struct dentry *base, int len)
+/**
+ * lookup_one_noperm - bad hack for sysfs
+ * @name:	pathname component to lookup
+ * @base:	base directory to lookup from
+ *
+ * This is a variant of lookup_one_len that doesn't perform any permission
+ * checks.   It's a horrible hack to work around the braindead sysfs
+ * architecture and should not be used anywhere else.
+ *
+ * DON'T USE THIS FUNCTION EVER, thanks.
+ */
+struct dentry *lookup_one_noperm(const char *name, struct dentry *base)
 {
 	int err;
 	struct qstr this;
 
-	err = __lookup_one_len(name, &this, base, len);
+	err = __lookup_one_len(name, &this, base, strlen(name));
 	if (err)
 		return ERR_PTR(err);
-	return __lookup_hash_kern(&this, base, NULL);
+	return __lookup_hash(&this, base, NULL);
 }
 
 int fastcall __user_walk_fd(int dfd, const char __user *name, unsigned flags,

Index: linux-2.6/fs/sysfs/dir.c
===================================================================
@@ -130,8 +130,7 @@ struct dentry *sysfs_get_dentry(struct s
 
 		/* look it up */
 		parent_dentry = dentry;
-		dentry = lookup_one_len_kern(cur->s_name, parent_dentry,
-					     strlen(cur->s_name));
+		dentry = lookup_one_noperm(cur->s_name, parent_dentry);
 		dput(parent_dentry);
 
 		if (IS_ERR(dentry)) {

Index: linux-2.6/include/linux/namei.h
===================================================================
@@ -81,8 +81,8 @@ extern struct file *lookup_instantiate_f
 extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
 extern void release_open_intent(struct nameidata *);
 
-extern struct dentry * lookup_one_len(const char *, struct dentry *, int);
-extern struct dentry *lookup_one_len_kern(const char *, struct dentry *, int);
+extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
+extern struct dentry *lookup_one_noperm(const char *, struct dentry *);
 
 extern int follow_down(struct vfsmount **, struct dentry **);
 extern int follow_up(struct vfsmount **, struct dentry **);