Split BAN_RefBan into BAN_FindBan and BAN_RefBan

BAN_FindBan looks up a ban based on a ban timestamp and returns a
pointer to the ban. Returns NULL if no ban with that timestamp is
present.

BAN_RefBan takes an objcore and a ban. It grabs a reference to the ban
and associates the objcore with that ban.

bin/varnishd/cache/cache.h

@@ -672,7 +672,8 @@ void BAN_Abandon(struct ban_proto *b);
 void BAN_Hold(void);
 void BAN_Release(void);
 void BAN_Reload(const uint8_t *ban, unsigned len);
-struct ban *BAN_RefBan(struct objcore *oc, double t0);
+struct ban *BAN_FindBan(double t0);
+void BAN_RefBan(struct objcore *oc, struct ban *);
 double BAN_Time(const struct ban *ban);
 
 /* cache_busyobj.c */

bin/varnishd/cache/cache_ban.c

@@ -249,29 +249,45 @@ BAN_DestroyObj(struct objcore *oc)
 }
 
 /*--------------------------------------------------------------------
- * Find and/or Grab a reference to an objects ban based on timestamp
+ * Find a ban based on timestamp a ban timestamp.
  * Assume we have a BAN_Hold, so list traversal is safe.
  */
 
 struct ban *
-BAN_RefBan(struct objcore *oc, double t0)
+BAN_FindBan(double t0)
 {
 	struct ban *b;
-	double t1 = 0;
+	double t1;
 
+	assert(ban_holds > 0);
 	VTAILQ_FOREACH(b, &ban_head, list) {
 		t1 = ban_time(b->spec);
+		if (t1 == t0)
+			return (b);
 		if (t1 <= t0)
 			break;
 	}
-	AN(b);
-	assert(t1 == t0);
+	return (NULL);
+}
+
+/*--------------------------------------------------------------------
+ * Grab a reference to a ban and associate the objcore with that ban.
+ * Assume we have a BAN_Hold, so list traversal is safe.
+ */
+
+void
+BAN_RefBan(struct objcore *oc, struct ban *b)
+{
+
 	Lck_Lock(&ban_mtx);
+	CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
+	AZ(oc->ban);
+	CHECK_OBJ_NOTNULL(b, BAN_MAGIC);
 	assert(ban_holds > 0);
 	b->refcount++;
 	VTAILQ_INSERT_TAIL(&b->objcore, oc, ban_list);
+	oc->ban = b;
 	Lck_Unlock(&ban_mtx);
-	return (b);
 }
 
 /*--------------------------------------------------------------------

bin/varnishd/storage/storage_persistent_silo.c

@@ -133,6 +133,7 @@ smp_load_seg(struct worker *wrk, const struct smp_sc *sc,
 {
 	struct smp_object *so;
 	struct objcore *oc;
+	struct ban *ban;
 	uint32_t no;
 	double t_now = VTIM_real();
 	struct smp_signctx ctx[1];
@@ -159,13 +160,16 @@ smp_load_seg(struct worker *wrk, const struct smp_sc *sc,
 	for (;no > 0; so++,no--) {
 		if (EXP_WHEN(so) < t_now)
 			continue;
+		ban = BAN_FindBan(so->ban);
+		AN(ban);
 		oc = ObjNew(wrk);
 		oc->flags &= ~OC_F_BUSY;
 		oc->stobj->stevedore = sc->parent;
 		smp_init_oc(oc, sg, no);
 		VTAILQ_INSERT_TAIL(&sg->objcores, oc, lru_list);
 		oc->stobj->priv2 |= NEED_FIXUP;
-		oc->ban = BAN_RefBan(oc, so->ban);
+		BAN_RefBan(oc, ban);
+		AN(oc->ban);
 		EXP_COPY(oc, so);
 		sg->nobj++;
 		oc->refcnt++;