Merge commit '038fcf1c' into thread-next

It was necessary to update the code to match removal of rta, as well as
existence of cached nested attribute lists.

2 files changed, 43 insertions, 7 deletions

diff --git a/lib/route.h b/lib/route.h
index 97e2e053..f5456396 100644
--- a/lib/route.h
+++ b/lib/route.h
@@ -257,7 +257,7 @@ typedef struct ea_list {
 struct ea_storage {
   struct ea_storage *next_hash;		/* Next in hash chain */
   struct ea_storage **pprev_hash;	/* Previous in hash chain */
-  u32 uc;				/* Use count */
+  _Atomic u32 uc;			/* Use count */
   u32 hash_key;				/* List hash */
   ea_list l[0];				/* The list itself */
 };
@@ -526,12 +526,15 @@ static inline struct ea_storage *ea_get_storage(ea_list *r)
   return SKIP_BACK(struct ea_storage, l[0], r);
 }
 
-static inline ea_list *ea_clone(ea_list *r) { ea_get_storage(r)->uc++; return r; }
+static inline ea_list *ea_clone(ea_list *r) {
+  ASSERT_DIE(0 < atomic_fetch_add_explicit(&ea_get_storage(r)->uc, 1, memory_order_acq_rel));
+  return r;
+}
 void ea__free(struct ea_storage *r);
 static inline void ea_free(ea_list *l) {
   if (!l) return;
   struct ea_storage *r = ea_get_storage(l);
-  if (!--r->uc) ea__free(r);
+  if (1 == atomic_fetch_sub_explicit(&r->uc, 1, memory_order_acq_rel)) ea__free(r);
 }
 
 void ea_dump(ea_list *);
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index b3a4c7a1..471209ee 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -1043,6 +1043,8 @@ ea_list_ref(ea_list *l)
   }
 }
 
+static void ea_free_nested(ea_list *l);
+
 static void
 ea_list_unref(ea_list *l)
 {
@@ -1063,7 +1065,7 @@ ea_list_unref(ea_list *l)
     }
 
   if (l->next)
-    ea_free(l->next);
+    ea_free_nested(l->next);
 }
 
 void
@@ -1472,9 +1474,15 @@ ea_lookup(ea_list *o, int overlay)
   o = ea_normalize(o, overlay);
   h = ea_hash(o);
 
+  RTA_LOCK;
+
   for(r=rta_hash_table[h & rta_cache_mask]; r; r=r->next_hash)
     if (r->hash_key == h && ea_same(r->l, o))
-      return ea_clone(r->l);
+    {
+      atomic_fetch_add_explicit(&r->uc, 1, memory_order_acq_rel);
+      RTA_UNLOCK;
+      return r->l;
+    }
 
   uint elen = ea_list_size(o);
   r = mb_alloc(rta_pool, elen + sizeof(struct ea_storage));
@@ -1490,12 +1498,17 @@ ea_lookup(ea_list *o, int overlay)
   if (++rta_cache_count > rta_cache_limit)
     rta_rehash();
 
+  RTA_UNLOCK;
   return r->l;
 }
 
-void
-ea__free(struct ea_storage *a)
+static void
+ea_free_locked(struct ea_storage *a)
 {
+  /* Somebody has cloned this rta inbetween. This sometimes happens. */
+  if (atomic_load_explicit(&a->uc, memory_order_acquire))
+    return;
+
   ASSERT(rta_cache_count);
   rta_cache_count--;
   *a->pprev_hash = a->next_hash;
@@ -1506,6 +1519,22 @@ ea__free(struct ea_storage *a)
   mb_free(a);
 }
 
+static void
+ea_free_nested(struct ea_list *l)
+{
+  struct ea_storage *r = ea_get_storage(l);
+  if (1 == atomic_fetch_sub_explicit(&r->uc, 1, memory_order_acq_rel))
+    ea_free_locked(r);
+}
+
+void
+ea__free(struct ea_storage *a)
+{
+  RTA_LOCK;
+  ea_free_locked(a);
+  RTA_UNLOCK;
+}
+
 /**
  * rta_dump_all - dump attribute cache
  *
@@ -1515,6 +1544,8 @@ ea__free(struct ea_storage *a)
 void
 ea_dump_all(void)
 {
+  RTA_LOCK;
+
   debug("Route attribute cache (%d entries, rehash at %d):\n", rta_cache_count, rta_cache_limit);
   for (uint h=0; h < rta_cache_size; h++)
     for (struct ea_storage *a = rta_hash_table[h]; a; a = a->next_hash)
@@ -1524,6 +1555,8 @@ ea_dump_all(void)
 	debug("\n");
       }
   debug("\n");
+
+  RTA_UNLOCK;
 }
 
 void