1 files changed, 87 insertions, 55 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 93b0310317be..2a46cbaef92d 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -40,24 +40,10 @@ struct dst_entry {
         struct rcu_head         rcu_head;
         struct dst_entry        *child;
         struct net_device       *dev;
-        short                   error;
-        short                   obsolete;
-        int                     flags;
-#define DST_HOST                0x0001
-#define DST_NOXFRM              0x0002
-#define DST_NOPOLICY            0x0004
-#define DST_NOHASH              0x0008
-#define DST_NOCACHE             0x0010
+        struct  dst_ops         *ops;
+        unsigned long           _metrics;
         unsigned long           expires;
-
-        unsigned short          header_len;     /* more space at head required */
-        unsigned short          trailer_len;    /* space to reserve at tail */
-
-        unsigned int            rate_tokens;
-        unsigned long           rate_last;      /* rate limiting for ICMP */
-
         struct dst_entry        *path;
-
         struct neighbour        *neighbour;
         struct hh_cache         *hh;
 #ifdef CONFIG_XFRM
@@ -68,17 +54,16 @@ struct dst_entry {
         int                     (*input)(struct sk_buff*);
         int                     (*output)(struct sk_buff*);
 
-        struct  dst_ops         *ops;
-
-        u32                     _metrics[RTAX_MAX];
-
-#ifdef CONFIG_NET_CLS_ROUTE
+        short                   error;
+        short                   obsolete;
+        unsigned short          header_len;     /* more space at head required */
+        unsigned short          trailer_len;    /* space to reserve at tail */
+#ifdef CONFIG_IP_ROUTE_CLASSID
         __u32                   tclassid;
 #else
         __u32                   __pad2;
 #endif
 
-
         /*
          * Align __refcnt to a 64 bytes alignment
          * (L1_CACHE_SIZE would be too much)
@@ -93,6 +78,12 @@ struct dst_entry {
         atomic_t                __refcnt;       /* client references    */
         int                     __use;
         unsigned long           lastuse;
+        int                     flags;
+#define DST_HOST                0x0001
+#define DST_NOXFRM              0x0002
+#define DST_NOPOLICY            0x0004
+#define DST_NOHASH              0x0008
+#define DST_NOCACHE             0x0010
         union {
                 struct dst_entry        *next;
                 struct rtable __rcu     *rt_next;
@@ -103,10 +94,70 @@ struct dst_entry {
 
 #ifdef __KERNEL__
 
+extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
+extern const u32 dst_default_metrics[RTAX_MAX];
+
+#define DST_METRICS_READ_ONLY   0x1UL
+#define __DST_METRICS_PTR(Y)    \
+        ((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
+#define DST_METRICS_PTR(X)      __DST_METRICS_PTR((X)->_metrics)
+
+static inline bool dst_metrics_read_only(const struct dst_entry *dst)
+{
+        return dst->_metrics & DST_METRICS_READ_ONLY;
+}
+
+extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
+
+static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
+{
+        unsigned long val = dst->_metrics;
+        if (!(val & DST_METRICS_READ_ONLY))
+                __dst_destroy_metrics_generic(dst, val);
+}
+
+static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
+{
+        unsigned long p = dst->_metrics;
+
+        if (p & DST_METRICS_READ_ONLY)
+                return dst->ops->cow_metrics(dst, p);
+        return __DST_METRICS_PTR(p);
+}
+
+/* This may only be invoked before the entry has reached global
+ * visibility.
+ */
+static inline void dst_init_metrics(struct dst_entry *dst,
+                                    const u32 *src_metrics,
+                                    bool read_only)
+{
+        dst->_metrics = ((unsigned long) src_metrics) |
+                (read_only ? DST_METRICS_READ_ONLY : 0);
+}
+
+static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
+{
+        u32 *dst_metrics = dst_metrics_write_ptr(dest);
+
+        if (dst_metrics) {
+                u32 *src_metrics = DST_METRICS_PTR(src);
+
+                memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
+        }
+}
+
+static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
+{
+        return DST_METRICS_PTR(dst);
+}
+
 static inline u32
 dst_metric_raw(const struct dst_entry *dst, const int metric)
 {
-        return dst->_metrics[metric-1];
+        u32 *p = DST_METRICS_PTR(dst);
+
+        return p[metric-1];
 }
 
 static inline u32
@@ -131,22 +182,10 @@ dst_metric_advmss(const struct dst_entry *dst)
 
 static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
 {
-        dst->_metrics[metric-1] = val;
-}
+        u32 *p = dst_metrics_write_ptr(dst);
 
-static inline void dst_import_metrics(struct dst_entry *dst, const u32 *src_metrics)
-{
-        memcpy(dst->_metrics, src_metrics, RTAX_MAX * sizeof(u32));
-}
-
-static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
-{
-        dst_import_metrics(dest, src->_metrics);
-}
-
-static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
-{
-        return dst->_metrics;
+        if (p)
+                p[metric-1] = val;
 }
 
 static inline u32
@@ -181,8 +220,6 @@ static inline u32
 dst_allfrag(const struct dst_entry *dst)
 {
         int ret = dst_feature(dst,  RTAX_FEATURE_ALLFRAG);
-        /* Yes, _exactly_. This is paranoia. */
-        barrier();
         return ret;
 }
 
@@ -315,7 +352,7 @@ static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
 }
 
 extern int dst_discard(struct sk_buff *skb);
-extern void * dst_alloc(struct dst_ops * ops);
+extern void *dst_alloc(struct dst_ops * ops, int initial_ref);
 extern void __dst_free(struct dst_entry * dst);
 extern struct dst_entry *dst_destroy(struct dst_entry * dst);
 
@@ -384,27 +421,22 @@ extern void		dst_init(void);
 
 /* Flags for xfrm_lookup flags argument. */
 enum {
-        XFRM_LOOKUP_WAIT = 1 << 0,
-        XFRM_LOOKUP_ICMP = 1 << 1,
+        XFRM_LOOKUP_ICMP = 1 << 0,
 };
 
 struct flowi;
 #ifndef CONFIG_XFRM
-static inline int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
-                              struct flowi *fl, struct sock *sk, int flags)
+static inline struct dst_entry *xfrm_lookup(struct net *net,
+                                            struct dst_entry *dst_orig,
+                                            const struct flowi *fl, struct sock *sk,
+                                            int flags)
 {
-        return 0;
+        return dst_orig;
 } 
-static inline int __xfrm_lookup(struct net *net, struct dst_entry **dst_p,
-                                struct flowi *fl, struct sock *sk, int flags)
-{
-        return 0;
-}
 #else
-extern int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
-                       struct flowi *fl, struct sock *sk, int flags);
-extern int __xfrm_lookup(struct net *net, struct dst_entry **dst_p,
-                         struct flowi *fl, struct sock *sk, int flags);
+extern struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
+                                     const struct flowi *fl, struct sock *sk,
+                                     int flags);
 #endif
 #endif