Add new variants of the IF_ADDR_*LOCK*() macros used for protecting

interface address lists that distinguish read locks from write locks.
To preserve the KPI, the previous operations are mapped to the write
lock macros.  The lock is still kept as a mutex for now.

Reviewed by:	bz
MFC after:	2 weeks

1 files changed, 8 insertions, 2 deletions

diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index ea60944..e78f287 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -249,9 +249,15 @@ typedef void if_init_f_t(void *);
 #define	IF_ADDR_LOCK_INIT(if)	mtx_init(&(if)->if_addr_mtx,		\
 				    "if_addr_mtx", NULL, MTX_DEF)
 #define	IF_ADDR_LOCK_DESTROY(if)	mtx_destroy(&(if)->if_addr_mtx)
-#define	IF_ADDR_LOCK(if)	mtx_lock(&(if)->if_addr_mtx)
-#define	IF_ADDR_UNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)
+#define	IF_ADDR_WLOCK(if)	mtx_lock(&(if)->if_addr_mtx)
+#define	IF_ADDR_WUNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)
+#define	IF_ADDR_RLOCK(if)	mtx_lock(&(if)->if_addr_mtx)
+#define	IF_ADDR_RUNLOCK(if)	mtx_unlock(&(if)->if_addr_mtx)
 #define	IF_ADDR_LOCK_ASSERT(if)	mtx_assert(&(if)->if_addr_mtx, MA_OWNED)
+#define	IF_ADDR_WLOCK_ASSERT(if)	mtx_assert(&(if)->if_addr_mtx, MA_OWNED)
+/* XXX: Compat. */
+#define	IF_ADDR_LOCK(if)	IF_ADDR_WLOCK(if)
+#define	IF_ADDR_UNLOCK(if)	IF_ADDR_WUNLOCK(if)
 
 /*
  * Function variations on locking macros intended to be used by loadable