4 files changed, 22 insertions, 25 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index cef46207408c..13c839d8235a 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -39,7 +39,6 @@ struct dst_entry {
         unsigned long           _metrics;
         unsigned long           expires;
         struct dst_entry        *path;
-        struct dst_entry        *from;
 #ifdef CONFIG_XFRM
         struct xfrm_state       *xfrm;
 #else
@@ -88,7 +87,7 @@ struct dst_entry {
          * Align __refcnt to a 64 bytes alignment
          * (L1_CACHE_SIZE would be too much)
          */
-        long                    __pad_to_align_refcnt[3];
+        long                    __pad_to_align_refcnt[4];
 #endif
         /*
          * __refcnt wants to be on a different cache line from
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 281a922f0c62..44d96a91e745 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -130,6 +130,7 @@ struct rt6_exception {
 struct rt6_info {
         struct dst_entry                dst;
         struct rt6_info __rcu           *rt6_next;
+        struct rt6_info                 *from;
 
         /*
          * Tail elements of dst_entry (__refcnt etc.)
@@ -204,11 +205,9 @@ static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
 {
         struct rt6_info *rt;
 
-        for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES);
-             rt = (struct rt6_info *)rt->dst.from);
+        for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES); rt = rt->from);
         if (rt && rt != rt0)
                 rt0->dst.expires = rt->dst.expires;
-
         dst_set_expires(&rt0->dst, timeout);
         rt0->rt6i_flags |= RTF_EXPIRES;
 }
@@ -243,8 +242,8 @@ static inline u32 rt6_get_cookie(const struct rt6_info *rt)
         u32 cookie = 0;
 
         if (rt->rt6i_flags & RTF_PCPU ||
-            (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->dst.from))
-                rt = (struct rt6_info *)(rt->dst.from);
+            (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->from))
+                rt = rt->from;
 
         rt6_get_cookie_safe(rt, &cookie);
 
diff --git a/net/core/dst.c b/net/core/dst.c
index 5cf96179e8e0..cf2076c0eb22 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -70,7 +70,6 @@ void dst_init(struct dst_entry *dst, struct dst_ops *ops,
         dst_init_metrics(dst, dst_default_metrics.metrics, true);
         dst->expires = 0UL;
         dst->path = dst;
-        dst->from = NULL;
 #ifdef CONFIG_XFRM
         dst->xfrm = NULL;
 #endif
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 22c5e70361d6..1f1ef1e071c2 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -186,7 +186,7 @@ static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)
 
 static u32 *rt6_pcpu_cow_metrics(struct rt6_info *rt)
 {
-        return dst_metrics_write_ptr(rt->dst.from);
+        return dst_metrics_write_ptr(&rt->from->dst);
 }
 
 static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)
@@ -391,7 +391,7 @@ static void ip6_dst_destroy(struct dst_entry *dst)
 {
         struct rt6_info *rt = (struct rt6_info *)dst;
         struct rt6_exception_bucket *bucket;
-        struct dst_entry *from = dst->from;
+        struct rt6_info *from = rt->from;
         struct inet6_dev *idev;
 
         dst_destroy_metrics_generic(dst);
@@ -409,8 +409,8 @@ static void ip6_dst_destroy(struct dst_entry *dst)
                 kfree(bucket);
         }
 
-        dst->from = NULL;
-        dst_release(from);
+        rt->from = NULL;
+        dst_release(&from->dst);
 }
 
 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
@@ -443,9 +443,9 @@ static bool rt6_check_expired(const struct rt6_info *rt)
         if (rt->rt6i_flags & RTF_EXPIRES) {
                 if (time_after(jiffies, rt->dst.expires))
                         return true;
-        } else if (rt->dst.from) {
+        } else if (rt->from) {
                 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
-                       rt6_check_expired((struct rt6_info *)rt->dst.from);
+                        rt6_check_expired(rt->from);
         }
         return false;
 }
@@ -1054,7 +1054,7 @@ static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort,
          */
 
         if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU))
-                ort = (struct rt6_info *)ort->dst.from;
+                ort = ort->from;
 
         rcu_read_lock();
         dev = ip6_rt_get_dev_rcu(ort);
@@ -1274,7 +1274,7 @@ static int rt6_insert_exception(struct rt6_info *nrt,
 
         /* ort can't be a cache or pcpu route */
         if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU))
-                ort = (struct rt6_info *)ort->dst.from;
+                ort = ort->from;
         WARN_ON_ONCE(ort->rt6i_flags & (RTF_CACHE | RTF_PCPU));
 
         spin_lock_bh(&rt6_exception_lock);
@@ -1415,8 +1415,8 @@ static struct rt6_info *rt6_find_cached_rt(struct rt6_info *rt,
 /* Remove the passed in cached rt from the hash table that contains it */
 int rt6_remove_exception_rt(struct rt6_info *rt)
 {
-        struct rt6_info *from = (struct rt6_info *)rt->dst.from;
         struct rt6_exception_bucket *bucket;
+        struct rt6_info *from = rt->from;
         struct in6_addr *src_key = NULL;
         struct rt6_exception *rt6_ex;
         int err;
@@ -1460,8 +1460,8 @@ int rt6_remove_exception_rt(struct rt6_info *rt)
  */
 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
 {
-        struct rt6_info *from = (struct rt6_info *)rt->dst.from;
         struct rt6_exception_bucket *bucket;
+        struct rt6_info *from = rt->from;
         struct in6_addr *src_key = NULL;
         struct rt6_exception *rt6_ex;
 
@@ -1929,9 +1929,9 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
 
 static void rt6_dst_from_metrics_check(struct rt6_info *rt)
 {
-        if (rt->dst.from &&
-            dst_metrics_ptr(&rt->dst) != dst_metrics_ptr(rt->dst.from))
-                dst_init_metrics(&rt->dst, dst_metrics_ptr(rt->dst.from), true);
+        if (rt->from &&
+            dst_metrics_ptr(&rt->dst) != dst_metrics_ptr(&rt->from->dst))
+                dst_init_metrics(&rt->dst, dst_metrics_ptr(&rt->from->dst), true);
 }
 
 static struct dst_entry *rt6_check(struct rt6_info *rt, u32 cookie)
@@ -1951,7 +1951,7 @@ static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, u32 cookie)
 {
         if (!__rt6_check_expired(rt) &&
             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
-            rt6_check((struct rt6_info *)(rt->dst.from), cookie))
+            rt6_check(rt->from, cookie))
                 return &rt->dst;
         else
                 return NULL;
@@ -1971,7 +1971,7 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
         rt6_dst_from_metrics_check(rt);
 
         if (rt->rt6i_flags & RTF_PCPU ||
-            (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->dst.from))
+            (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->from))
                 return rt6_dst_from_check(rt, cookie);
         else
                 return rt6_check(rt, cookie);
@@ -3055,11 +3055,11 @@ out:
 
 static void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)
 {
-        BUG_ON(from->dst.from);
+        BUG_ON(from->from);
 
         rt->rt6i_flags &= ~RTF_EXPIRES;
         dst_hold(&from->dst);
-        rt->dst.from = &from->dst;
+        rt->from = from;
         dst_init_metrics(&rt->dst, dst_metrics_ptr(&from->dst), true);
 }