Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"

This reverts commit d1ba277e79889085a2faec3b68b91ce89c63f888.

Tejun writes:
        I'm sorry but can you please revert the whole series?
        get_active() waiting while a node is deactivated has potential
        to lead to deadlock and that deactivate/reactivate interface is
        something fundamentally flawed and that cgroup will have to work
        with the remove_self() like everybody else.  IOW, I think the
        first posting was correct.

Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 19 insertions, 1 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index fb1ba13f7665..1ff3f1697513 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -566,6 +566,12 @@ extern int __must_check device_create_bin_file(struct device *dev,
 					const struct bin_attribute *attr);
 extern void device_remove_bin_file(struct device *dev,
 				   const struct bin_attribute *attr);
+extern int device_schedule_callback_owner(struct device *dev,
+		void (*func)(struct device *dev), struct module *owner);
+
+/* This is a macro to avoid include problems with THIS_MODULE */
+#define device_schedule_callback(dev, func)			\
+	device_schedule_callback_owner(dev, func, THIS_MODULE)
 
 /* device resource management */
 typedef void (*dr_release_t)(struct device *dev, void *res);
@@ -925,7 +931,10 @@ extern int device_online(struct device *dev);
 extern struct device *__root_device_register(const char *name,
 					     struct module *owner);
 
-/* This is a macro to avoid include problems with THIS_MODULE */
+/*
+ * This is a macro to avoid include problems with THIS_MODULE,
+ * just as per what is done for device_schedule_callback() above.
+ */
 #define root_device_register(name) \
 	__root_device_register(name, THIS_MODULE)
 
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 14df05415af9..bd96c603ab6c 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -178,6 +178,9 @@ struct sysfs_ops {
 
 #ifdef CONFIG_SYSFS
 
+int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
+			    void *data, struct module *owner);
+
 int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
 void sysfs_remove_dir(struct kobject *kobj);
 int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
@@ -246,6 +249,12 @@ int __must_check sysfs_init(void);
 
 #else /* CONFIG_SYSFS */
 
+static inline int sysfs_schedule_callback(struct kobject *kobj,
+		void (*func)(void *), void *data, struct module *owner)
+{
+	return -ENOSYS;
+}
+
 static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
 {
 	return 0;