Driver core: fix class glue dir cleanup logic

We should remove the glue directory between the class and the bus
device _after_ we sent out the 'remove' event for the device, otherwise
the parent relationship is no longer valid, and composing the path
with deleted sysfs entries will not work.

Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 94 insertions, 112 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 22fdf320a2a6..13cae18936c5 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -18,7 +18,7 @@
 #include <linux/string.h>
 #include <linux/kdev_t.h>
 #include <linux/notifier.h>
-
+#include <linux/genhd.h>
 #include <asm/semaphore.h>
 
 #include "base.h"
@@ -538,22 +538,20 @@ void device_initialize(struct device *dev)
 }
 
 #ifdef CONFIG_SYSFS_DEPRECATED
-static struct kobject * get_device_parent(struct device *dev,
-                                          struct device *parent)
+static struct kobject *get_device_parent(struct device *dev,
+                                         struct device *parent)
 {
-        /*
-         * Set the parent to the class, not the parent device
-         * for topmost devices in class hierarchy.
-         * This keeps sysfs from having a symlink to make old
-         * udevs happy
-         */
+        /* class devices without a parent live in /sys/class/<classname>/ */
         if (dev->class && (!parent || parent->class != dev->class))
                 return &dev->class->subsys.kobj;
+        /* all other devices keep their parent */
         else if (parent)
                 return &parent->kobj;
 
         return NULL;
 }
+
+static inline void cleanup_device_parent(struct device *dev) {}
 #else
 static struct kobject *virtual_device_parent(struct device *dev)
 {
@@ -566,8 +564,8 @@ static struct kobject *virtual_device_parent(struct device *dev)
         return virtual_dir;
 }
 
-static struct kobject * get_device_parent(struct device *dev,
-                                          struct device *parent)
+static struct kobject *get_device_parent(struct device *dev,
+                                         struct device *parent)
 {
         int retval;
 
@@ -618,6 +616,34 @@ static struct kobject * get_device_parent(struct device *dev,
                 return &parent->kobj;
         return NULL;
 }
+
+static void cleanup_device_parent(struct device *dev)
+{
+        struct device *d;
+        int other = 0;
+
+        if (!dev->class)
+                return;
+
+        /* see if we live in a parent class directory */
+        if (dev->kobj.parent->kset != &dev->class->class_dirs)
+                return;
+
+        /* if we are the last child of our class, delete the directory */
+        down(&dev->class->sem);
+        list_for_each_entry(d, &dev->class->devices, node) {
+                if (d == dev)
+                        continue;
+                if (d->kobj.parent == dev->kobj.parent) {
+                        other = 1;
+                        break;
+                }
+        }
+        if (!other)
+                kobject_del(dev->kobj.parent);
+        kobject_put(dev->kobj.parent);
+        up(&dev->class->sem);
+}
 #endif
 
 static int setup_parent(struct device *dev, struct device *parent)
@@ -637,65 +663,74 @@ static int device_add_class_symlinks(struct device *dev)
 
         if (!dev->class)
                 return 0;
+
         error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
                                   "subsystem");
         if (error)
                 goto out;
-        /*
-         * If this is not a "fake" compatible device, then create the
-         * symlink from the class to the device.
-         */
+
+#ifdef CONFIG_SYSFS_DEPRECATED
+        /* stacked class devices need a symlink in the class directory */
         if (dev->kobj.parent != &dev->class->subsys.kobj) {
                 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
                                           dev->bus_id);
                 if (error)
                         goto out_subsys;
         }
+
         if (dev->parent) {
-#ifdef CONFIG_SYSFS_DEPRECATED
-                {
-                        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;
+                struct device *parent = dev->parent;
+                char *class_name;
 
-                        class_name = make_class_name(dev->class->name,
-                                                        &dev->kobj);
-                        if (class_name)
-                                error = sysfs_create_link(&dev->parent->kobj,
-                                                        &dev->kobj, class_name);
-                        kfree(class_name);
-                        if (error)
-                                goto out_device;
-                }
-#else
-                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
+                /*
+                 * stacked class devices have the 'device' link
+                 * pointing to the bus device instead of the 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;
-#endif
+
+                class_name = make_class_name(dev->class->name,
+                                                &dev->kobj);
+                if (class_name)
+                        error = sysfs_create_link(&dev->parent->kobj,
+                                                &dev->kobj, class_name);
+                kfree(class_name);
+                if (error)
+                        goto out_device;
         }
         return 0;
 
-#ifdef CONFIG_SYSFS_DEPRECATED
 out_device:
         if (dev->parent)
                 sysfs_remove_link(&dev->kobj, "device");
-#endif
 out_busid:
         if (dev->kobj.parent != &dev->class->subsys.kobj)
                 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+#else
+        /* link in the class directory pointing to the device */
+        error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
+                                  dev->bus_id);
+        if (error)
+                goto out_subsys;
+
+        if (dev->parent) {
+                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
+                                          "device");
+                if (error)
+                        goto out_busid;
+        }
+        return 0;
+
+out_busid:
+        sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+#endif
+
 out_subsys:
         sysfs_remove_link(&dev->kobj, "subsystem");
 out:
@@ -706,8 +741,9 @@ static void device_remove_class_symlinks(struct device *dev)
 {
         if (!dev->class)
                 return;
-        if (dev->parent) {
+
 #ifdef CONFIG_SYSFS_DEPRECATED
+        if (dev->parent) {
                 char *class_name;
 
                 class_name = make_class_name(dev->class->name, &dev->kobj);
@@ -715,11 +751,18 @@ static void device_remove_class_symlinks(struct device *dev)
                         sysfs_remove_link(&dev->parent->kobj, class_name);
                         kfree(class_name);
                 }
-#endif
                 sysfs_remove_link(&dev->kobj, "device");
         }
+
         if (dev->kobj.parent != &dev->class->subsys.kobj)
                 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+#else
+        if (dev->parent)
+                sysfs_remove_link(&dev->kobj, "device");
+
+        sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+#endif
+
         sysfs_remove_link(&dev->kobj, "subsystem");
 }
 
@@ -830,26 +873,6 @@ int device_add(struct device *dev)
  SymlinkError:
         if (MAJOR(dev->devt))
                 device_remove_file(dev, &devt_attr);
-
-        if (dev->class) {
-                sysfs_remove_link(&dev->kobj, "subsystem");
-                /* If this is not a "fake" compatible device, remove the
-                 * symlink from the class to the device. */
-                if (dev->kobj.parent != &dev->class->subsys.kobj)
-                        sysfs_remove_link(&dev->class->subsys.kobj,
-                                          dev->bus_id);
-                if (parent) {
-#ifdef CONFIG_SYSFS_DEPRECATED
-                        char *class_name = make_class_name(dev->class->name,
-                                                           &dev->kobj);
-                        if (class_name)
-                                sysfs_remove_link(&dev->parent->kobj,
-                                                  class_name);
-                        kfree(class_name);
-#endif
-                        sysfs_remove_link(&dev->kobj, "device");
-                }
-        }
  ueventattrError:
         device_remove_file(dev, &uevent_attr);
  attrError:
@@ -932,23 +955,7 @@ void device_del(struct device * dev)
         if (MAJOR(dev->devt))
                 device_remove_file(dev, &devt_attr);
         if (dev->class) {
-                sysfs_remove_link(&dev->kobj, "subsystem");
-                /* If this is not a "fake" compatible device, remove the
-                 * symlink from the class to the device. */
-                if (dev->kobj.parent != &dev->class->subsys.kobj)
-                        sysfs_remove_link(&dev->class->subsys.kobj,
-                                          dev->bus_id);
-                if (parent) {
-#ifdef CONFIG_SYSFS_DEPRECATED
-                        char *class_name = make_class_name(dev->class->name,
-                                                           &dev->kobj);
-                        if (class_name)
-                                sysfs_remove_link(&dev->parent->kobj,
-                                                  class_name);
-                        kfree(class_name);
-#endif
-                        sysfs_remove_link(&dev->kobj, "device");
-                }
+                device_remove_class_symlinks(dev);
 
                 down(&dev->class->sem);
                 /* notify any interfaces that the device is now gone */
@@ -958,31 +965,6 @@ void device_del(struct device * dev)
                 /* remove the device from the class list */
                 list_del_init(&dev->node);
                 up(&dev->class->sem);
-
-                /* If we live in a parent class-directory, unreference it */
-                if (dev->kobj.parent->kset == &dev->class->class_dirs) {
-                        struct device *d;
-                        int other = 0;
-
-                        /*
-                         * if we are the last child of our class, delete
-                         * our class-directory at this parent
-                         */
-                        down(&dev->class->sem);
-                        list_for_each_entry(d, &dev->class->devices, node) {
-                                if (d == dev)
-                                        continue;
-                                if (d->kobj.parent == dev->kobj.parent) {
-                                        other = 1;
-                                        break;
-                                }
-                        }
-                        if (!other)
-                                kobject_del(dev->kobj.parent);
-
-                        kobject_put(dev->kobj.parent);
-                        up(&dev->class->sem);
-                }
         }
         device_remove_file(dev, &uevent_attr);
         device_remove_attrs(dev);
@@ -1004,9 +986,9 @@ void device_del(struct device * dev)
                 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
                                              BUS_NOTIFY_DEL_DEVICE, dev);
         kobject_uevent(&dev->kobj, KOBJ_REMOVE);
+        cleanup_device_parent(dev);
         kobject_del(&dev->kobj);
-        if (parent)
-                put_device(parent);
+        put_device(parent);
 }
 
 /**