Clean up common ifaddr management:

- Unify reference count and lock initialization in a single function,
  ifa_init().
- Move tear-down from a macro (IFAFREE) to a function ifa_free().
- Move reference count bump from a macro (IFAREF) to a function ifa_ref().
- Instead of using a u_int protected by a mutex to refcount(9) for
  reference count management.

The ifa_mtx is now used for exactly one ioctl, and possibly should be
removed.

MFC after:	3 weeks

1 files changed, 6 insertions, 21 deletions

diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index 556aace..cbd274a 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -706,11 +706,14 @@ struct ifaddr {
 /* for compatibility with other BSDs */
 #define	ifa_list	ifa_link
 
-#define	IFA_LOCK_INIT(ifa)	\
-    mtx_init(&(ifa)->ifa_mtx, "ifaddr", NULL, MTX_DEF)
+#ifdef _KERNEL
 #define	IFA_LOCK(ifa)		mtx_lock(&(ifa)->ifa_mtx)
 #define	IFA_UNLOCK(ifa)		mtx_unlock(&(ifa)->ifa_mtx)
-#define	IFA_DESTROY(ifa)	mtx_destroy(&(ifa)->ifa_mtx)
+
+void	ifa_free(struct ifaddr *ifa);
+void	ifa_init(struct ifaddr *ifa);
+void	ifa_ref(struct ifaddr *ifa);
+#endif
 
 /*
  * The prefix structure contains information about one prefix
@@ -741,24 +744,6 @@ struct ifmultiaddr {
 };
 
 #ifdef _KERNEL
-#define	IFAFREE(ifa)					\
-	do {						\
-		IFA_LOCK(ifa);				\
-		KASSERT((ifa)->ifa_refcnt > 0,		\
-		    ("ifa %p !(ifa_refcnt > 0)", ifa));	\
-		if (--(ifa)->ifa_refcnt == 0) {		\
-			IFA_DESTROY(ifa);		\
-			free(ifa, M_IFADDR);		\
-		} else 					\
-			IFA_UNLOCK(ifa);		\
-	} while (0)
-
-#define IFAREF(ifa)					\
-	do {						\
-		IFA_LOCK(ifa);				\
-		++(ifa)->ifa_refcnt;			\
-		IFA_UNLOCK(ifa);			\
-	} while (0)
 
 extern	struct rwlock ifnet_lock;
 #define	IFNET_LOCK_INIT() \