keep rpzs around until everything referencing it has gone

lib/dns/include/dns/rpz.h

@@ -247,6 +247,7 @@ struct dns_rpz_zones {
 	isc_timermgr_t		*timermgr;
 	isc_task_t		*updater;
 	isc_refcount_t		refs;
+	isc_refcount_t		irefs;
 	/*
 	 * One lock for short term read-only search that guarantees the
 	 * consistency of the pointers.

lib/dns/rpz.c

@@ -170,7 +170,10 @@ struct dns_rpz_nm_data {
 };
 
 static void
-rpz_detach(dns_rpz_zone_t **rpzp, dns_rpz_zones_t *rpzs);
+rpz_detach(dns_rpz_zone_t **rpzp);
+
+static void
+rpz_detach_rpzs(dns_rpz_zones_t **rpzsp);
 
 #if 0
 /*
@@ -1447,6 +1450,7 @@ dns_rpz_new_zones(dns_rpz_zones_t **rpzsp, char *rps_cstr,
 
 	isc_mutex_init(&zones->maint_lock);
 	isc_refcount_init(&zones->refs, 1);
+	isc_refcount_init(&zones->irefs, 1);
 
 	zones->rps_cstr = rps_cstr;
 	zones->rps_cstr_size = rps_cstr_size;
@@ -1480,7 +1484,9 @@ cleanup_task:
 	dns_rbt_destroy(&zones->rbt);
 
 cleanup_rbt:
-	INSIST(isc_refcount_decrement(&zones->refs) > 0);
+	INSIST(isc_refcount_decrement(&zones->irefs) == 1);
+	isc_refcount_destroy(&zones->irefs);
+	INSIST(isc_refcount_decrement(&zones->refs) == 1);
 	isc_refcount_destroy(&zones->refs);
 
 	isc_mutex_destroy(&zones->maint_lock);
@@ -1543,6 +1549,7 @@ dns_rpz_new_zone(dns_rpz_zones_t *rpzs, dns_rpz_zone_t **rpzp) {
 	zone->updb = NULL;
 	zone->updbversion = NULL;
 	zone->updbit = NULL;
+	isc_refcount_increment(&rpzs->irefs);
 	zone->rpzs = rpzs;
 	zone->db_registered = false;
 	zone->addsoa = true;
@@ -1563,7 +1570,7 @@ cleanup_timer:
 	INSIST(isc_refcount_decrement(&zone->refs) > 0);
 	isc_refcount_destroy(&zone->refs);
 
-	isc_mem_put(zone->rpzs->mctx, zone, sizeof(*zone));
+	isc_mem_put(rpzs->mctx, zone, sizeof(*zone));
 
 	return (result);
 }
@@ -1983,7 +1990,7 @@ update_quantum(isc_task_t *task, isc_event_t *event) {
 		isc_ht_destroy(&rpz->newnodes);
 	dns_db_closeversion(rpz->updb, &rpz->updbversion, false);
 	dns_db_detach(&rpz->updb);
-	rpz_detach(&rpz, rpz->rpzs);
+	rpz_detach(&rpz);
 }
 
 static void
@@ -2023,7 +2030,7 @@ dns_rpz_update_from_db(dns_rpz_zone_t *rpz) {
 		isc_ht_destroy(&rpz->newnodes);
 	dns_db_closeversion(rpz->updb, &rpz->updbversion, false);
 	dns_db_detach(&rpz->updb);
-	rpz_detach(&rpz, rpz->rpzs);
+	rpz_detach(&rpz);
 }
 
 /*
@@ -2063,8 +2070,9 @@ cidr_free(dns_rpz_zones_t *rpzs) {
  * before discarding the overall rpz structure.
  */
 static void
-rpz_detach(dns_rpz_zone_t **rpzp, dns_rpz_zones_t *rpzs) {
+rpz_detach(dns_rpz_zone_t **rpzp) {
 	dns_rpz_zone_t *rpz;
+	dns_rpz_zones_t *rpzs;
 
 	REQUIRE(rpzp != NULL && *rpzp != NULL);
 
@@ -2077,6 +2085,9 @@ rpz_detach(dns_rpz_zone_t **rpzp, dns_rpz_zones_t *rpzs) {
 
 	isc_refcount_destroy(&rpz->refs);
 
+	rpzs = rpz->rpzs;
+	rpz->rpzs = NULL;
+
 	if (dns_name_dynamic(&rpz->origin)) {
 		dns_name_free(&rpz->origin, rpzs->mctx);
 	}
@@ -2129,7 +2140,9 @@ rpz_detach(dns_rpz_zone_t **rpzp, dns_rpz_zones_t *rpzs) {
 	isc_timer_detach(&rpz->updatetimer);
 
 	isc_ht_destroy(&rpz->nodes);
+
 	isc_mem_put(rpzs->mctx, rpz, sizeof(*rpz));
+	rpz_detach_rpzs(&rpzs);
 }
 
 void
@@ -2166,10 +2179,20 @@ dns_rpz_detach_rpzs(dns_rpz_zones_t **rpzsp) {
 			dns_rpz_zone_t *rpz = rpzs->zones[rpz_num];
 			rpzs->zones[rpz_num] = NULL;
 			if (rpz != NULL) {
-				rpz_detach(&rpz, rpzs);
+				rpz_detach(&rpz);
 			}
 		}
+		rpz_detach_rpzs(&rpzs);
+	}
+}
+
+static void
+rpz_detach_rpzs(dns_rpz_zones_t **rpzsp) {
+	REQUIRE(rpzsp != NULL && *rpzsp != NULL);
+	dns_rpz_zones_t *rpzs = *rpzsp;
+	*rpzsp = NULL;
 
+	if (isc_refcount_decrement(&rpzs->irefs) == 1) {
 		if (rpzs->rps_cstr_size != 0) {
 #ifdef USE_DNSRPS
 			librpz->client_detach(&rpzs->rps_client);