drivers/net: remove some rcu sparse warnings

Add missing __rcu annotations and helpers.
minor : Fix some rcu_dereference() calls in macvtap

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 5933621..2300e45 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -39,7 +39,7 @@
 	struct socket sock;
 	struct socket_wq wq;
 	int vnet_hdr_sz;
-	struct macvlan_dev *vlan;
+	struct macvlan_dev __rcu *vlan;
 	struct file *file;
 	unsigned int flags;
 };
@@ -141,7 +141,8 @@
 	struct macvlan_dev *vlan;
 
 	spin_lock(&macvtap_lock);
-	vlan = rcu_dereference(q->vlan);
+	vlan = rcu_dereference_protected(q->vlan,
+					 lockdep_is_held(&macvtap_lock));
 	if (vlan) {
 		int index = get_slot(vlan, q);
 
@@ -219,7 +220,8 @@
 	/* macvtap_put_queue can free some slots, so go through all slots */
 	spin_lock(&macvtap_lock);
 	for (i = 0; i < MAX_MACVTAP_QUEUES && vlan->numvtaps; i++) {
-		q = rcu_dereference(vlan->taps[i]);
+		q = rcu_dereference_protected(vlan->taps[i],
+					      lockdep_is_held(&macvtap_lock));
 		if (q) {
 			qlist[j++] = q;
 			rcu_assign_pointer(vlan->taps[i], NULL);
@@ -569,7 +571,7 @@
 	}
 
 	rcu_read_lock_bh();
-	vlan = rcu_dereference(q->vlan);
+	vlan = rcu_dereference_bh(q->vlan);
 	if (vlan)
 		macvlan_start_xmit(skb, vlan->dev);
 	else
@@ -583,7 +585,7 @@
 
 err:
 	rcu_read_lock_bh();
-	vlan = rcu_dereference(q->vlan);
+	vlan = rcu_dereference_bh(q->vlan);
 	if (vlan)
 		vlan->dev->stats.tx_dropped++;
 	rcu_read_unlock_bh();
@@ -631,7 +633,7 @@
 	ret = skb_copy_datagram_const_iovec(skb, 0, iv, vnet_hdr_len, len);
 
 	rcu_read_lock_bh();
-	vlan = rcu_dereference(q->vlan);
+	vlan = rcu_dereference_bh(q->vlan);
 	if (vlan)
 		macvlan_count_rx(vlan, len, ret == 0, 0);
 	rcu_read_unlock_bh();
@@ -727,7 +729,7 @@
 
 	case TUNGETIFF:
 		rcu_read_lock_bh();
-		vlan = rcu_dereference(q->vlan);
+		vlan = rcu_dereference_bh(q->vlan);
 		if (vlan)
 			dev_hold(vlan->dev);
 		rcu_read_unlock_bh();
@@ -736,7 +738,7 @@
 			return -ENOLINK;
 
 		ret = 0;
-		if (copy_to_user(&ifr->ifr_name, q->vlan->dev->name, IFNAMSIZ) ||
+		if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
 		    put_user(q->flags, &ifr->ifr_flags))
 			ret = -EFAULT;
 		dev_put(vlan->dev);