libata-acpi: improve dock event handling

[sfrench/cifs-2.6.git] / lib / kref.c

diff --git a/lib/kref.c b/lib/kref.c
index 4a467faf1367bb031d49eb136ac16de0551a1629..9ecd6e86561034f2a097bcc027765704e124f7df 100644 (file)
--- a/lib/kref.c
+++ b/lib/kref.c
@@ -14,13 +14,24 @@
 #include <linux/kref.h>
 #include <linux/module.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)
 {
-       atomic_set(&kref->refcount,1);
+       kref_set(kref, 1);
 }
 
 /**
@@ -31,6 +42,7 @@ void kref_get(struct kref *kref)
 {
        WARN_ON(!atomic_read(&kref->refcount));
        atomic_inc(&kref->refcount);
+       smp_mb__after_atomic_inc();
 }
 
 /**
@@ -52,18 +64,14 @@ int kref_put(struct kref *kref, void (*release)(struct kref *kref))
        WARN_ON(release == NULL);
        WARN_ON(release == (void (*)(struct kref *))kfree);
 
-       /*
-        * if current count is one, we are the last user and can release object
-        * right now, avoiding an atomic operation on 'refcount'
-        */
-       if ((atomic_read(&kref->refcount) == 1) ||
-           (atomic_dec_and_test(&kref->refcount))) {
+       if (atomic_dec_and_test(&kref->refcount)) {
                release(kref);
                return 1;
        }
        return 0;
 }
 
+EXPORT_SYMBOL(kref_set);
 EXPORT_SYMBOL(kref_init);
 EXPORT_SYMBOL(kref_get);
 EXPORT_SYMBOL(kref_put);