4010. [cleanup] Clear the prefetchable state when initiating a prefetch.

[RT #37399]

CHANGES

@@ -1,3 +1,6 @@
+4010.	[cleanup]	Clear the prefetchable state when initiating a prefetch.
+			[RT #37399]
+
 4009.	[func]		delv: added a +tcp option. [RT #37855]
 
 4008.	[contrib]	Updated zkt to latest version (1.1.3). [RT #37886]

bin/named/query.c

@@ -3880,7 +3880,8 @@ query_prefetch(ns_client_t *client, dns_name_t *qname,
 	ns_client_t *dummy = NULL;
 	unsigned int options;
 
-	if (client->view->prefetch_trigger == 0U ||
+	if (client->query.prefetch != NULL ||
+	    client->view->prefetch_trigger == 0U ||
 	    rdataset->ttl > client->view->prefetch_trigger ||
 	    (rdataset->attributes & DNS_RDATASETATTR_PREFETCH) == 0)
 		return;
@@ -3893,8 +3894,6 @@ query_prefetch(ns_client_t *client, dns_name_t *qname,
 		isc_stats_increment(ns_g_server->nsstats,
 				    dns_nsstatscounter_recursclients);
 	}
-	if (client->query.prefetch != NULL)
-		return;
 
 	tmprdataset = query_newrdataset(client);
 	if (tmprdataset == NULL)
@@ -3916,6 +3915,7 @@ query_prefetch(ns_client_t *client, dns_name_t *qname,
 		query_putrdataset(client, &tmprdataset);
 		ns_client_detach(&dummy);
 	}
+	dns_rdataset_clearprefetch(rdataset);
 }
 
 static isc_result_t

lib/dns/ecdb.c

@@ -113,7 +113,8 @@ static dns_rdatasetmethods_t rdataset_methods = {
 	NULL,			/* setadditional */
 	NULL,			/* putadditional */
 	rdataset_settrust,	/* settrust */
-	NULL			/* expire */
+	NULL,			/* expire */
+	NULL			/* clearprefetch */
 };
 
 typedef struct ecdb_rdatasetiter {

lib/dns/include/dns/rdataset.h

@@ -114,6 +114,7 @@ typedef struct dns_rdatasetmethods {
 	void			(*settrust)(dns_rdataset_t *rdataset,
 					    dns_trust_t trust);
 	void			(*expire)(dns_rdataset_t *rdataset);
+	void			(*clearprefetch)(dns_rdataset_t *rdataset);
 } dns_rdatasetmethods_t;
 
 #define DNS_RDATASET_MAGIC	       ISC_MAGIC('D','N','S','R')
@@ -654,6 +655,17 @@ dns_rdataset_expire(dns_rdataset_t *rdataset);
  * Mark the rdataset to be expired in the backing database.
  */
 
+void
+dns_rdataset_clearprefetch(dns_rdataset_t *rdataset);
+/*%<
+ * Clear the PREFETCH attribute for the given rdataset in the
+ * underlying database.
+ *
+ * In the cache database, this signals that the rdataset is not
+ * eligible to be prefetched when the TTL is close to expiring.
+ * It has no function in other databases.
+ */
+
 void
 dns_rdataset_trimttl(dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
 		     dns_rdata_rrsig_t *rrsig, isc_stdtime_t now,

lib/dns/ncache.c

@@ -503,6 +503,7 @@ static dns_rdatasetmethods_t rdataset_methods = {
 	NULL,
 	NULL,
 	rdataset_settrust,
+	NULL,
 	NULL
 };
 

lib/dns/rbtdb.c

@@ -744,6 +744,7 @@ static void resign_delete(dns_rbtdb_t *rbtdb, rbtdb_version_t *version,
 static void prune_tree(isc_task_t *task, isc_event_t *event);
 static void rdataset_settrust(dns_rdataset_t *rdataset, dns_trust_t trust);
 static void rdataset_expire(dns_rdataset_t *rdataset);
+static void rdataset_clearprefetch(dns_rdataset_t *rdataset);
 
 static dns_rdatasetmethods_t rdataset_methods = {
 	rdataset_disassociate,
@@ -760,7 +761,8 @@ static dns_rdatasetmethods_t rdataset_methods = {
 	rdataset_setadditional,
 	rdataset_putadditional,
 	rdataset_settrust,
-	rdataset_expire
+	rdataset_expire,
+	rdataset_clearprefetch
 };
 
 static void rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp);
@@ -8721,6 +8723,19 @@ rdataset_expire(dns_rdataset_t *rdataset) {
 		  isc_rwlocktype_write);
 }
 
+static void
+rdataset_clearprefetch(dns_rdataset_t *rdataset) {
+	dns_rbtdb_t *rbtdb = rdataset->private1;
+	dns_rbtnode_t *rbtnode = rdataset->private2;
+	rdatasetheader_t *header = rdataset->private3;
+
+	NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
+		  isc_rwlocktype_write);
+	header->attributes &= ~RDATASET_ATTR_PREFETCH;
+	NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
+		  isc_rwlocktype_write);
+}
+
 /*
  * Rdataset Iterator Methods
  */

lib/dns/rdatalist.c

@@ -48,6 +48,7 @@ static dns_rdatasetmethods_t methods = {
 	NULL,
 	NULL,
 	NULL,
+	NULL,
 	NULL
 };
 

lib/dns/rdataset.c

@@ -206,6 +206,7 @@ static dns_rdatasetmethods_t question_methods = {
 	NULL,
 	NULL,
 	NULL,
+	NULL,
 	NULL
 };
 
@@ -775,6 +776,15 @@ dns_rdataset_expire(dns_rdataset_t *rdataset) {
 		(rdataset->methods->expire)(rdataset);
 }
 
+void
+dns_rdataset_clearprefetch(dns_rdataset_t *rdataset) {
+	REQUIRE(DNS_RDATASET_VALID(rdataset));
+	REQUIRE(rdataset->methods != NULL);
+
+	if (rdataset->methods->clearprefetch != NULL)
+		(rdataset->methods->clearprefetch)(rdataset);
+}
+
 void
 dns_rdataset_trimttl(dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
 		     dns_rdata_rrsig_t *rrsig, isc_stdtime_t now,

lib/dns/rdataslab.c

@@ -466,6 +466,7 @@ static dns_rdatasetmethods_t rdataset_methods = {
 	NULL,
 	NULL,
 	NULL,
+	NULL,
 	NULL
 };
 

lib/dns/sdb.c

@@ -1429,6 +1429,7 @@ static dns_rdatasetmethods_t methods = {
 	NULL,
 	NULL,
 	NULL,
+	NULL,
 	NULL
 };
 

lib/dns/sdlz.c

@@ -1481,6 +1481,7 @@ static dns_rdatasetmethods_t rdataset_methods = {
 	NULL,
 	NULL,
 	NULL,
+	NULL,
 	NULL
 };
 

lib/dns/win32/libdns.def.in

@@ -608,6 +608,7 @@ dns_rdataclass_totext
 dns_rdatalist_init
 dns_rdatalist_tordataset
 dns_rdataset_additionaldata
+dns_rdataset_clearprefetch
 dns_rdataset_clone
 dns_rdataset_count
 dns_rdataset_current