---

yaml
---
r: 280063
b: refs/heads/master
c: 4af679c
h: refs/heads/master
i:
  280061: fd1bc92
  280059: 83b8dca
  280055: dab8852
  280047: 58f4aba
  280031: 132d023
  279999: fa2f501
  279935: 77ce5c1
  279807: 4dbbc53
  279551: 8a264bc
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 175cad266774d09c57a62c65baa6b4e1edafdf3a
+refs/heads/master: 4af679cd7cbb0a0d8774b5cdb34bffcaa4e86e52

trunk/include/linux/kref.h

@@ -16,15 +16,85 @@
 #define _KREF_H_
 
 #include <linux/types.h>
+#include <linux/slab.h>
 
 struct kref {
 	atomic_t refcount;
 };
 
-void kref_init(struct kref *kref);
-void kref_get(struct kref *kref);
-int kref_put(struct kref *kref, void (*release) (struct kref *kref));
-int kref_sub(struct kref *kref, unsigned int count,
-	     void (*release) (struct kref *kref));
+/**
+ * kref_init - initialize object.
+ * @kref: object in question.
+ */
+static inline void kref_init(struct kref *kref)
+{
+	atomic_set(&kref->refcount, 1);
+	smp_mb();
+}
+
+/**
+ * kref_get - increment refcount for object.
+ * @kref: object.
+ */
+static inline void kref_get(struct kref *kref)
+{
+	WARN_ON(!atomic_read(&kref->refcount));
+	atomic_inc(&kref->refcount);
+	smp_mb__after_atomic_inc();
+}
+
+/**
+ * kref_put - decrement refcount for object.
+ * @kref: object.
+ * @release: pointer to the function that will clean up the object when the
+ *	     last reference to the object is released.
+ *	     This pointer is required, and it is not acceptable to pass kfree
+ *	     in as this function.
+ *
+ * Decrement the refcount, and if 0, call release().
+ * Return 1 if the object was removed, otherwise return 0.  Beware, if this
+ * function returns 0, you still can not count on the kref from remaining in
+ * memory.  Only use the return value if you want to see if the kref is now
+ * gone, not present.
+ */
+static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref))
+{
+	WARN_ON(release == NULL);
+	WARN_ON(release == (void (*)(struct kref *))kfree);
+
+	if (atomic_dec_and_test(&kref->refcount)) {
+		release(kref);
+		return 1;
+	}
+	return 0;
+}
+
+
+/**
+ * kref_sub - subtract a number of refcounts for object.
+ * @kref: object.
+ * @count: Number of recounts to subtract.
+ * @release: pointer to the function that will clean up the object when the
+ *	     last reference to the object is released.
+ *	     This pointer is required, and it is not acceptable to pass kfree
+ *	     in as this function.
+ *
+ * Subtract @count from the refcount, and if 0, call release().
+ * Return 1 if the object was removed, otherwise return 0.  Beware, if this
+ * function returns 0, you still can not count on the kref from remaining in
+ * memory.  Only use the return value if you want to see if the kref is now
+ * gone, not present.
+ */
+static inline int kref_sub(struct kref *kref, unsigned int count,
+	     void (*release)(struct kref *kref))
+{
+	WARN_ON(release == NULL);
+	WARN_ON(release == (void (*)(struct kref *))kfree);
 
+	if (atomic_sub_and_test((int) count, &kref->refcount)) {
+		release(kref);
+		return 1;
+	}
+	return 0;
+}
 #endif /* _KREF_H_ */

trunk/lib/Makefile

@@ -17,7 +17,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
 
-lib-y	+= kobject.o kref.o klist.o
+lib-y	+= kobject.o klist.o
 
 obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
 	 bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \