kobject: Export kobject_get_unless_zero()

commit c70c176ff8c3ff0ac6ef9a831cd591ea9a66bd1a upstream.

Make the function available for outside use and fortify it against NULL
kobject.

CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index 5957c6a..d9d4485 100644 (file)
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -108,6 +108,8 @@ extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 extern int __must_check kobject_move(struct kobject *, struct kobject *);
 
 extern struct kobject *kobject_get(struct kobject *kobj);
+extern struct kobject * __must_check kobject_get_unless_zero(
+                                               struct kobject *kobj);
 extern void kobject_put(struct kobject *kobj);
 
 extern const void *kobject_namespace(struct kobject *kobj);

diff --git a/lib/kobject.c b/lib/kobject.c
index 35d490b..cebbe79 100644 (file)
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -599,12 +599,15 @@ struct kobject *kobject_get(struct kobject *kobj)
 }
 EXPORT_SYMBOL(kobject_get);
 
-static struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
+struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
 {
+       if (!kobj)
+               return NULL;
        if (!kref_get_unless_zero(&kobj->kref))
                kobj = NULL;
        return kobj;
 }
+EXPORT_SYMBOL(kobject_get_unless_zero);
 
 /*
  * kobject_cleanup - free kobject resources.