driver core: Implement tagged directory support for device classes.

This patch enables tagging on every class directory if struct class
has tag_ops.

In addition device_del and device_rename were modified to use
sysfs_delete_link and sysfs_rename_link respectively to ensure
when these operations happen on devices whose classes have
tag_ops that they work properly.

Signed-off-by: Eric W. Biederman <[EMAIL PROTECTED]>
Signed-off-by: Benjamin Thery <[EMAIL PROTECTED]>
---
 drivers/base/class.c   |   30 ++++++++++++++++++++++++++----
 drivers/base/core.c    |   41 ++++++++++++++++++++++-------------------
 include/linux/device.h |    2 ++
 3 files changed, 50 insertions(+), 23 deletions(-)

Index: linux-mm/drivers/base/class.c
===================================================================
--- linux-mm.orig/drivers/base/class.c
+++ linux-mm/drivers/base/class.c
@@ -134,6 +134,17 @@ static void remove_class_attrs(struct cl
        }
 }
 
+static int class_setup_tagging(struct class *cls)
+{
+       const struct sysfs_tagged_dir_operations *tag_ops;
+
+       tag_ops = cls->tag_ops;
+       if (!tag_ops)
+               return 0;
+
+       return sysfs_enable_tagging(&cls->subsys.kobj, tag_ops);
+}
+
 int class_register(struct class *cls)
 {
        int error;
@@ -162,11 +173,22 @@ int class_register(struct class *cls)
        cls->subsys.kobj.ktype = &class_ktype;
 
        error = kset_register(&cls->subsys);
-       if (!error) {
-               error = add_class_attrs(class_get(cls));
-               class_put(cls);
-       }
+       if (error)
+               goto out;
+
+       error = class_setup_tagging(cls);
+       if (error)
+               goto out_unregister;
+
+       error = add_class_attrs(cls);
+       if (error)
+               goto out_unregister;
+
+out:
        return error;
+out_unregister:
+       kset_unregister(&cls->subsys);
+       goto out;
 }
 
 void class_unregister(struct class *cls)
Index: linux-mm/drivers/base/core.c
===================================================================
--- linux-mm.orig/drivers/base/core.c
+++ linux-mm/drivers/base/core.c
@@ -617,6 +617,10 @@ static struct kobject *get_device_parent
                        kobject_put(k);
                        return NULL;
                }
+               /* If we created a new class-directory setup tagging */
+               if (dev->class->tag_ops)
+                       sysfs_enable_tagging(k, dev->class->tag_ops);
+
                /* do not emit an uevent for this simple "glue" directory */
                return k;
        }
@@ -751,12 +755,13 @@ static void device_remove_class_symlinks
 
        if (dev->kobj.parent != &dev->class->subsys.kobj &&
            device_is_not_partition(dev))
-               sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+               sysfs_delete_link(&dev->class->subsys.kobj, &dev->kobj,
+                                 dev->bus_id);
 #else
        if (dev->parent && device_is_not_partition(dev))
                sysfs_remove_link(&dev->kobj, "device");
 
-       sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+       sysfs_delete_link(&dev->class->subsys.kobj, &dev->kobj, dev->bus_id);
 #endif
 
        sysfs_remove_link(&dev->kobj, "subsystem");
@@ -1282,6 +1287,15 @@ int device_rename(struct device *dev, ch
        strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
        strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
 
+#ifndef CONFIG_SYSFS_DEPRECATED
+       if (dev->class && (dev->kobj.parent != &dev->class->subsys.kobj)) {
+               error = sysfs_rename_link(&dev->class->subsys.kobj,
+                       &dev->kobj, old_device_name, new_name);
+               if (error)
+                       goto out;
+       }
+#endif
+
        error = kobject_rename(&dev->kobj, new_name);
        if (error) {
                strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
@@ -1290,24 +1304,13 @@ int device_rename(struct device *dev, ch
 
 #ifdef CONFIG_SYSFS_DEPRECATED
        if (old_class_name) {
+               error = -ENOMEM;
                new_class_name = make_class_name(dev->class->name, &dev->kobj);
-               if (new_class_name) {
-                       error = sysfs_create_link(&dev->parent->kobj,
-                                                 &dev->kobj, new_class_name);
-                       if (error)
-                               goto out;
-                       sysfs_remove_link(&dev->parent->kobj, old_class_name);
-               }
-       }
-#else
-       if (dev->class) {
-               sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
-               error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
-                                         dev->bus_id);
-               if (error) {
-                       dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
-                               __func__, error);
-               }
+               if (new_class_name)
+                       error = sysfs_rename_link(&dev->parent->kobj,
+                                                 &dev->kobj,
+                                                 old_class_name,
+                                                 new_class_name);
        }
 #endif
 
Index: linux-mm/include/linux/device.h
===================================================================
--- linux-mm.orig/include/linux/device.h
+++ linux-mm/include/linux/device.h
@@ -199,6 +199,8 @@ struct class {
        int (*suspend)(struct device *dev, pm_message_t state);
        int (*resume)(struct device *dev);
 
+       const struct sysfs_tagged_dir_operations *tag_ops;
+
        struct pm_ops *pm;
 };
 

-- 
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