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-rw-r--r--include/net/dst.h114
1 files changed, 77 insertions, 37 deletions
diff --git a/include/net/dst.h b/include/net/dst.h
index be5a0d4c491d..94a8c234ea2a 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];
-
+ 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 +78,14 @@ struct dst_entry {
atomic_t __refcnt; /* client references */
int __use;
unsigned long lastuse;
+ unsigned long rate_last; /* rate limiting for ICMP */
+ unsigned int rate_tokens;
+ 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 +96,69 @@ struct dst_entry {
#ifdef __KERNEL__
+extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
+
+#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 +183,10 @@ 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;
-}
-
-static inline void dst_import_metrics(struct dst_entry *dst, const u32 *src_metrics)
-{
- memcpy(dst->_metrics, src_metrics, RTAX_MAX * sizeof(u32));
-}
+ u32 *p = dst_metrics_write_ptr(dst);
-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