kref: remove kref_set

Of the three uses of kref_set in the kernel:

 One really should be kref_put as the code is letting go of a
    reference,
 Two really should be kref_init because the kref is being
    initialised.

This suggests that making kref_set available encourages bad code.
So fix the three uses and remove kref_set completely.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 6 insertions, 18 deletions

diff --git a/include/linux/kref.h b/include/linux/kref.h
index baf4b9e4b194..6cc38fc07ab7 100644
--- a/include/linux/kref.h
+++ b/include/linux/kref.h
@@ -21,7 +21,6 @@ struct kref {
         atomic_t refcount;
 };
 
-void kref_set(struct kref *kref, int num);
 void kref_init(struct kref *kref);
 void kref_get(struct kref *kref);
 int kref_put(struct kref *kref, void (*release) (struct kref *kref));
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 076c7c8215b0..b2d70d38dff4 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -54,8 +54,8 @@ int create_user_ns(struct cred *new)
 #endif
         /* tgcred will be cleared in our caller bc CLONE_THREAD won't be set */
 
-        /* alloc_uid() incremented the userns refcount.  Just set it to 1 */
-        kref_set(&ns->kref, 1);
+        /* root_user holds a reference to ns, our reference can be dropped */
+        put_user_ns(ns);
 
         return 0;
 }
diff --git a/lib/kref.c b/lib/kref.c
index 6d19f690380b..d3d227a08a4b 100644
--- a/lib/kref.c
+++ b/lib/kref.c
@@ -16,23 +16,13 @@
 #include <linux/slab.h>
 
 /**
- * kref_set - initialize object and set refcount to requested number.
- * @kref: object in question.
- * @num: initial reference counter
- */
-void kref_set(struct kref *kref, int num)
-{
-        atomic_set(&kref->refcount, num);
-        smp_mb();
-}
-
-/**
  * kref_init - initialize object.
  * @kref: object in question.
  */
 void kref_init(struct kref *kref)
 {
-        kref_set(kref, 1);
+        atomic_set(&kref->refcount, 1);
+        smp_mb();
 }
 
 /**
@@ -72,7 +62,6 @@ int kref_put(struct kref *kref, void (*release)(struct kref *kref))
         return 0;
 }
 
-EXPORT_SYMBOL(kref_set);
 EXPORT_SYMBOL(kref_init);
 EXPORT_SYMBOL(kref_get);
 EXPORT_SYMBOL(kref_put);
diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
index 2dc2d6594145..7625b85c2274 100644
--- a/security/integrity/ima/ima_iint.c
+++ b/security/integrity/ima/ima_iint.c
@@ -94,7 +94,7 @@ void iint_free(struct kref *kref)
                        iint->opencount);
                 iint->opencount = 0;
         }
-        kref_set(&iint->refcount, 1);
+        kref_init(&iint->refcount);
         kmem_cache_free(iint_cache, iint);
 }
 
@@ -133,7 +133,7 @@ static void init_once(void *foo)
         iint->readcount = 0;
         iint->writecount = 0;
         iint->opencount = 0;
-        kref_set(&iint->refcount, 1);
+        kref_init(&iint->refcount);
 }
 
 static int __init ima_iintcache_init(void)