class: add lockdep infrastructure

This adds the infrastructure to properly handle lockdep issues when the
internal class semaphore is changed to a mutex.

Matthew wrote the original patch, and Greg fixed it up to work properly
with the class_create() function.


From: Matthew Wilcox <matthew@wil.cx>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/base/class.c b/drivers/base/class.c
index d24d21114ccb..89000566690c 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -134,7 +134,7 @@ static void remove_class_attrs(struct class *cls)
         }
 }
 
-int class_register(struct class *cls)
+int __class_register(struct class *cls, struct lock_class_key *key)
 {
         struct class_private *cp;
         int error;
@@ -178,6 +178,7 @@ int class_register(struct class *cls)
         class_put(cls);
         return error;
 }
+EXPORT_SYMBOL_GPL(__class_register);
 
 void class_unregister(struct class *cls)
 {
@@ -203,7 +204,8 @@ static void class_create_release(struct class *cls)
  * Note, the pointer created here is to be destroyed when finished by
  * making a call to class_destroy().
  */
-struct class *class_create(struct module *owner, const char *name)
+struct class *__class_create(struct module *owner, const char *name,
+                             struct lock_class_key *key)
 {
         struct class *cls;
         int retval;
@@ -218,7 +220,7 @@ struct class *class_create(struct module *owner, const char *name)
         cls->owner = owner;
         cls->class_release = class_create_release;
 
-        retval = class_register(cls);
+        retval = __class_register(cls, key);
         if (retval)
                 goto error;
 
@@ -228,6 +230,7 @@ error:
         kfree(cls);
         return ERR_PTR(retval);
 }
+EXPORT_SYMBOL_GPL(__class_create);
 
 /**
  * class_destroy - destroys a struct class structure
@@ -412,9 +415,7 @@ int __init classes_init(void)
 
 EXPORT_SYMBOL_GPL(class_create_file);
 EXPORT_SYMBOL_GPL(class_remove_file);
-EXPORT_SYMBOL_GPL(class_register);
 EXPORT_SYMBOL_GPL(class_unregister);
-EXPORT_SYMBOL_GPL(class_create);
 EXPORT_SYMBOL_GPL(class_destroy);
 
 EXPORT_SYMBOL_GPL(class_interface_register);