Driver core: fix deprectated sysfs structure for nested class devices

Nested class devices used to have 'device' symlink point to a real
(physical) device instead of a parent class device.  When converting
subsystems to struct device we need to keep doing what class devices did if
CONFIG_SYSFS_DEPRECATED is Y, otherwise parts of udev break.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Greg KH <greg@kroah.com>
Tested-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 6 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index e6738bcbe5a9..6de33d7a29ba 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -679,14 +679,26 @@ static int device_add_class_symlinks(struct device *dev)
                         goto out_subsys;
         }
         if (dev->parent) {
-                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
-                                          "device");
-                if (error)
-                        goto out_busid;
 #ifdef CONFIG_SYSFS_DEPRECATED
                 {
-                        char * class_name = make_class_name(dev->class->name,
-                                                                &dev->kobj);
+                        struct device *parent = dev->parent;
+                        char *class_name;
+
+                        /*
+                         * In old sysfs stacked class devices had 'device'
+                         * link pointing to real device instead of parent
+                         */
+                        while (parent->class && !parent->bus && parent->parent)
+                                parent = parent->parent;
+
+                        error = sysfs_create_link(&dev->kobj,
+                                                  &parent->kobj,
+                                                  "device");
+                        if (error)
+                                goto out_busid;
+
+                        class_name = make_class_name(dev->class->name,
+                                                        &dev->kobj);
                         if (class_name)
                                 error = sysfs_create_link(&dev->parent->kobj,
                                                         &dev->kobj, class_name);
@@ -694,6 +706,11 @@ static int device_add_class_symlinks(struct device *dev)
                         if (error)
                                 goto out_device;
                 }
+#else
+                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
+                                          "device");
+                if (error)
+                        goto out_busid;
 #endif
         }
         return 0;