net/ipv6: Remove rt6i_prefsrc

After the conversion to fib6_info, rt6i_prefsrc has a single user that
reads the value and otherwise it is only set. The one reader can be
converted to use rt->from so rt6i_prefsrc can be removed, reducing
rt6_info by another 20 bytes.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/scsi/cxgbi/libcxgbi.c

@@ -784,7 +784,7 @@ cxgbi_check_route6(struct sockaddr *dst_addr, int ifindex)
 	csk->mtu = mtu;
 	csk->dst = dst;
 
-	if (ipv6_addr_any(&rt->rt6i_prefsrc.addr)) {
+	if (!rt->from || ipv6_addr_any(&rt->from->fib6_prefsrc.addr)) {
 		struct inet6_dev *idev = ip6_dst_idev((struct dst_entry *)rt);
 
 		err = ipv6_dev_get_saddr(&init_net, idev ? idev->dev : NULL,
@@ -795,7 +795,7 @@ cxgbi_check_route6(struct sockaddr *dst_addr, int ifindex)
 			goto rel_rt;
 		}
 	} else {
-		pref_saddr = rt->rt6i_prefsrc.addr;
+		pref_saddr = rt->from->fib6_prefsrc.addr;
 	}
 
 	csk->csk_family = AF_INET6;

include/net/ip6_fib.h

@@ -182,7 +182,6 @@ struct rt6_info {
 	struct in6_addr			rt6i_gateway;
 	struct inet6_dev		*rt6i_idev;
 	u32				rt6i_flags;
-	struct rt6key			rt6i_prefsrc;
 
 	struct list_head		rt6i_uncached;
 	struct uncached_list		*rt6i_uncached_list;

net/ipv6/route.c

@@ -995,7 +995,6 @@ static void ip6_rt_copy_init(struct rt6_info *rt, struct fib6_info *ort)
 #ifdef CONFIG_IPV6_SUBTREES
 	rt->rt6i_src = ort->fib6_src;
 #endif
-	rt->rt6i_prefsrc = ort->fib6_prefsrc;
 }
 
 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
@@ -1449,11 +1448,6 @@ static int rt6_insert_exception(struct rt6_info *nrt,
 	if (ort->fib6_src.plen)
 		src_key = &nrt->rt6i_src.addr;
 #endif
-
-	/* Update rt6i_prefsrc as it could be changed
-	 * in rt6_remove_prefsrc()
-	 */
-	nrt->rt6i_prefsrc = ort->fib6_prefsrc;
 	/* rt6_mtu_change() might lower mtu on ort.
 	 * Only insert this exception route if its mtu
 	 * is less than ort's mtu value.
@@ -1635,25 +1629,6 @@ static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
 	rcu_read_unlock();
 }
 
-static void rt6_exceptions_remove_prefsrc(struct fib6_info *rt)
-{
-	struct rt6_exception_bucket *bucket;
-	struct rt6_exception *rt6_ex;
-	int i;
-
-	bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
-					lockdep_is_held(&rt6_exception_lock));
-
-	if (bucket) {
-		for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
-			hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
-				rt6_ex->rt6i->rt6i_prefsrc.plen = 0;
-			}
-			bucket++;
-		}
-	}
-}
-
 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
 					 struct rt6_info *rt, int mtu)
 {
@@ -3793,8 +3768,6 @@ static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
 		spin_lock_bh(&rt6_exception_lock);
 		/* remove prefsrc entry */
 		rt->fib6_prefsrc.plen = 0;
-		/* need to update cache as well */
-		rt6_exceptions_remove_prefsrc(rt);
 		spin_unlock_bh(&rt6_exception_lock);
 	}
 	return 0;