1 files changed, 41 insertions, 2 deletions

diff --git a/net/core/dst.c b/net/core/dst.c
index b99c7c7ffce2..91104d35de7d 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -164,7 +164,9 @@ int dst_discard(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(dst_discard);
 
-void *dst_alloc(struct dst_ops *ops)
+const u32 dst_default_metrics[RTAX_MAX];
+
+void *dst_alloc(struct dst_ops *ops, int initial_ref)
 {
         struct dst_entry *dst;
 
@@ -175,11 +177,12 @@ void *dst_alloc(struct dst_ops *ops)
         dst = kmem_cache_zalloc(ops->kmem_cachep, GFP_ATOMIC);
         if (!dst)
                 return NULL;
-        atomic_set(&dst->__refcnt, 0);
+        atomic_set(&dst->__refcnt, initial_ref);
         dst->ops = ops;
         dst->lastuse = jiffies;
         dst->path = dst;
         dst->input = dst->output = dst_discard;
+        dst_init_metrics(dst, dst_default_metrics, true);
 #if RT_CACHE_DEBUG >= 2
         atomic_inc(&dst_total);
 #endif
@@ -282,6 +285,42 @@ void dst_release(struct dst_entry *dst)
 }
 EXPORT_SYMBOL(dst_release);
 
+u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old)
+{
+        u32 *p = kmalloc(sizeof(u32) * RTAX_MAX, GFP_ATOMIC);
+
+        if (p) {
+                u32 *old_p = __DST_METRICS_PTR(old);
+                unsigned long prev, new;
+
+                memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
+
+                new = (unsigned long) p;
+                prev = cmpxchg(&dst->_metrics, old, new);
+
+                if (prev != old) {
+                        kfree(p);
+                        p = __DST_METRICS_PTR(prev);
+                        if (prev & DST_METRICS_READ_ONLY)
+                                p = NULL;
+                }
+        }
+        return p;
+}
+EXPORT_SYMBOL(dst_cow_metrics_generic);
+
+/* Caller asserts that dst_metrics_read_only(dst) is false.  */
+void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old)
+{
+        unsigned long prev, new;
+
+        new = (unsigned long) dst_default_metrics;
+        prev = cmpxchg(&dst->_metrics, old, new);
+        if (prev == old)
+                kfree(__DST_METRICS_PTR(old));
+}
+EXPORT_SYMBOL(__dst_destroy_metrics_generic);
+
 /**
  * skb_dst_set_noref - sets skb dst, without a reference
  * @skb: buffer