+static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
+ char *path)
+{
+ char * s;
+ int depth, size;
+
+ depth = object_depth(kobj);
+ size = object_path_length(target) + depth * 3 - 1;
+ if (size > PATH_MAX)
+ return -ENAMETOOLONG;
+
+ pr_debug("%s: depth = %d, size = %d\n", __FUNCTION__, depth, size);
+
+ for (s = path; depth--; s += 3)
+ strcpy(s,"../");
+
+ fill_object_path(target, path, size);
+ pr_debug("%s: path = '%s'\n", __FUNCTION__, path);
+
+ return 0;
+}
+
+static int sysfs_getlink(struct dentry *dentry, char * path)
+{
+ struct kobject *kobj, *target_kobj;
+ int error = 0;
+
+ kobj = sysfs_get_kobject(dentry->d_parent);
+ if (!kobj)
+ return -EINVAL;
+
+ target_kobj = sysfs_get_kobject(dentry);
+ if (!target_kobj) {
+ kobject_put(kobj);
+ return -EINVAL;
+ }
+
+ down_read(&sysfs_rename_sem);
+ error = sysfs_get_target_path(kobj, target_kobj, path);
+ up_read(&sysfs_rename_sem);
+
+ kobject_put(kobj);
+ kobject_put(target_kobj);
+ return error;
+
+}
+
+int sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ int error = -ENOMEM;
+ unsigned long page = get_zeroed_page(GFP_KERNEL);
+ if (page)
+ error = sysfs_getlink(dentry, (char *) page);
+ nd_set_link(nd, error ? ERR_PTR(error) : (char *)page);
+ return 0;
+}
+
+void sysfs_put_link(struct dentry *dentry, struct nameidata *nd)
+{
+ char *page = nd_get_link(nd);
+ if (!IS_ERR(page))
+ free_page((unsigned long)page);
+}