From: Ondřej Surý <ondrej@isc.org>
Date: Mon, 30 Mar 2026 09:54:34 +0000 (+0200)
Subject: Remove the dead dns_expire_ttl code path and deletettl stats counter
X-Git-Tag: v9.21.21~3^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9e40f6508cf8c04d62b64441b663dbaf81f2a749;p=thirdparty%2Fbind9.git

Remove the dead dns_expire_ttl code path and deletettl stats counter

Now that TTL-based cleaning has been removed, the dns_expire_ttl enum
value, its switch case in expireheader(), and the deletettl stats counter
(text, XML, JSON) are all dead code.  Remove them so the stats channel
no longer reports a permanently-zero counter.
---

diff --git a/lib/dns/cache.c b/lib/dns/cache.c
index 04e7133f46d..f0bc00ab85a 100644
--- a/lib/dns/cache.c
+++ b/lib/dns/cache.c
@@ -562,9 +562,6 @@ dns_cache_dumpstats(dns_cache_t *cache, FILE *fp) {
 	fprintf(fp, "%20" PRIu64 " %s\n",
 		values[dns_cachestatscounter_deletelru],
 		"cache records deleted due to memory exhaustion");
-	fprintf(fp, "%20" PRIu64 " %s\n",
-		values[dns_cachestatscounter_deletettl],
-		"cache records deleted due to TTL expiration");
 	fprintf(fp, "%20" PRIu64 " %s\n",
 		values[dns_cachestatscounter_coveringnsec],
 		"covering nsec returned");
@@ -617,8 +614,6 @@ dns_cache_renderxml(dns_cache_t *cache, void *writer0) {
 			values[dns_cachestatscounter_querymisses], writer));
 	TRY0(renderstat("DeleteLRU", values[dns_cachestatscounter_deletelru],
 			writer));
-	TRY0(renderstat("DeleteTTL", values[dns_cachestatscounter_deletettl],
-			writer));
 	TRY0(renderstat("CoveringNSEC",
 			values[dns_cachestatscounter_coveringnsec], writer));
 
@@ -672,10 +667,6 @@ dns_cache_renderjson(dns_cache_t *cache, void *cstats0) {
 	CHECKMEM(obj);
 	json_object_object_add(cstats, "DeleteLRU", obj);
 
-	obj = json_object_new_int64(values[dns_cachestatscounter_deletettl]);
-	CHECKMEM(obj);
-	json_object_object_add(cstats, "DeleteTTL", obj);
-
 	obj = json_object_new_int64(values[dns_cachestatscounter_coveringnsec]);
 	CHECKMEM(obj);
 	json_object_object_add(cstats, "CoveringNSEC", obj);
diff --git a/lib/dns/include/dns/stats.h b/lib/dns/include/dns/stats.h
index ed0e9878984..cc4b5532f9f 100644
--- a/lib/dns/include/dns/stats.h
+++ b/lib/dns/include/dns/stats.h
@@ -120,10 +120,9 @@ enum {
 	dns_cachestatscounter_queryhits = 3,
 	dns_cachestatscounter_querymisses = 4,
 	dns_cachestatscounter_deletelru = 5,
-	dns_cachestatscounter_deletettl = 6,
-	dns_cachestatscounter_coveringnsec = 7,
+	dns_cachestatscounter_coveringnsec = 6,
 
-	dns_cachestatscounter_max = 8,
+	dns_cachestatscounter_max = 7,
 
 	/*%
 	 * Query statistics counters (obsolete).
diff --git a/lib/dns/include/dns/types.h b/lib/dns/include/dns/types.h
index ea65a16bf95..18816cc21da 100644
--- a/lib/dns/include/dns/types.h
+++ b/lib/dns/include/dns/types.h
@@ -249,8 +249,7 @@ typedef enum {
 
 typedef enum {
 	dns_expire_lru = 0,
-	dns_expire_ttl = 1,
-	dns_expire_flush = 2,
+	dns_expire_flush = 1,
 } dns_expire_t;
 
 /*
diff --git a/lib/dns/qpcache.c b/lib/dns/qpcache.c
index 7c85dc3f647..690cf753941 100644
--- a/lib/dns/qpcache.c
+++ b/lib/dns/qpcache.c
@@ -920,10 +920,6 @@ expireheader(dns_slabheader_t *header, isc_rwlocktype_t *nlocktypep,
 		}
 
 		switch (reason) {
-		case dns_expire_ttl:
-			isc_stats_increment(qpdb->cachestats,
-					    dns_cachestatscounter_deletettl);
-			break;
 		case dns_expire_lru:
 			isc_stats_increment(qpdb->cachestats,
 					    dns_cachestatscounter_deletelru);