RDMA/cma: Remove padding arrays by using struct sockaddr_storage

There are a few places where the RDMA CM code handles IPv6 by doing

	struct sockaddr		addr;
	u8			pad[sizeof(struct sockaddr_in6) -
				    sizeof(struct sockaddr)];

This is fragile and ugly; handle this in a better way with just

	struct sockaddr_storage	addr;

[ Also roll in patch from Aleksey Senin <alekseys@voltaire.com> to
  switch to struct sockaddr_storage and get rid of padding arrays in
  struct rdma_addr. ]

Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index b41dd26..3ddacf3 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -81,9 +81,7 @@
 
 	u64			uid;
 	struct list_head	list;
-	struct sockaddr		addr;
-	u8			pad[sizeof(struct sockaddr_in6) -
-				    sizeof(struct sockaddr)];
+	struct sockaddr_storage	addr;
 };
 
 struct ucma_event {
@@ -603,11 +601,11 @@
 		return PTR_ERR(ctx);
 
 	memset(&resp, 0, sizeof resp);
-	addr = &ctx->cm_id->route.addr.src_addr;
+	addr = (struct sockaddr *) &ctx->cm_id->route.addr.src_addr;
 	memcpy(&resp.src_addr, addr, addr->sa_family == AF_INET ?
 				     sizeof(struct sockaddr_in) :
 				     sizeof(struct sockaddr_in6));
-	addr = &ctx->cm_id->route.addr.dst_addr;
+	addr = (struct sockaddr *) &ctx->cm_id->route.addr.dst_addr;
 	memcpy(&resp.dst_addr, addr, addr->sa_family == AF_INET ?
 				     sizeof(struct sockaddr_in) :
 				     sizeof(struct sockaddr_in6));
@@ -913,7 +911,7 @@
 
 	mc->uid = cmd.uid;
 	memcpy(&mc->addr, &cmd.addr, sizeof cmd.addr);
-	ret = rdma_join_multicast(ctx->cm_id, &mc->addr, mc);
+	ret = rdma_join_multicast(ctx->cm_id, (struct sockaddr *) &mc->addr, mc);
 	if (ret)
 		goto err2;
 
@@ -929,7 +927,7 @@
 	return 0;
 
 err3:
-	rdma_leave_multicast(ctx->cm_id, &mc->addr);
+	rdma_leave_multicast(ctx->cm_id, (struct sockaddr *) &mc->addr);
 	ucma_cleanup_mc_events(mc);
 err2:
 	mutex_lock(&mut);
@@ -975,7 +973,7 @@
 		goto out;
 	}
 
-	rdma_leave_multicast(mc->ctx->cm_id, &mc->addr);
+	rdma_leave_multicast(mc->ctx->cm_id, (struct sockaddr *) &mc->addr);
 	mutex_lock(&mc->ctx->file->mut);
 	ucma_cleanup_mc_events(mc);
 	list_del(&mc->list);