From: Evan Hunt <each@isc.org>
Date: Fri, 14 Aug 2026 00:17:44 +0000 (-0700)
Subject: "rndc flushtree ." failed to flush the cache
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=231db283546fa6b4d82f0fcb13e0696988520e64;p=thirdparty%2Fbind9.git

"rndc flushtree ." failed to flush the cache

`rndc flushtree` flushes cache data below a specified name. If the name
specified is the DNS root, that should fully empty the cache, the same
as `rndc flush`.  However, there was a bug causing that command to have
no effect on the cache at all; this has been fixed.
---

diff --git a/bin/named/server.c b/bin/named/server.c
index 89a30b07fd2..e9e018a97ee 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -11476,7 +11476,11 @@ flushnode_cache(dns_view_t *view, const dns_name_t *name, const char *target,
 	 * if some of the views share a single cache.  But since the
 	 * operation is lightweight we prefer simplicity here.
 	 */
-	result = dns_view_flushnode(view, name, tree);
+	if (dns_name_equal(name, dns_rootname)) {
+		result = dns_view_flushcache(view, false);
+	} else {
+		result = dns_view_flushnode(view, name, tree);
+	}
 	if (result != ISC_R_SUCCESS) {
 		isc_log_write(NAMED_LOGCATEGORY_GENERAL, NAMED_LOGMODULE_SERVER,
 			      ISC_LOG_ERROR,
diff --git a/bin/tests/system/cacheclean/tests.sh b/bin/tests/system/cacheclean/tests.sh
index fe71c2f8627..cb0e0e822e3 100755
--- a/bin/tests/system/cacheclean/tests.sh
+++ b/bin/tests/system/cacheclean/tests.sh
@@ -278,5 +278,21 @@ grep EXPIRE: dig.out.expire >/dev/null || ret=1
 if [ $ret != 0 ]; then echo_i "failed"; fi
 status=$((status + ret))
 
+n=$((n + 1))
+echo_i "check 'flushtree .' is equivalent to 'flush' ($n)"
+ret=0
+clear_cache
+dump_cache
+grep -v DATE ns2/named_dump.db.test$n >ns2/named_dump.db.test$n.a
+load_cache
+dump_cache
+grep -v DATE ns2/named_dump.db.test$n >ns2/named_dump.db.test$n.b
+$RNDC $RNDCOPTS flushtree . || ret=1
+dump_cache
+grep -v DATE ns2/named_dump.db.test$n >ns2/named_dump.db.test$n.c
+cmp -s ns2/named_dump.db.test$n.a ns2/named_dump.db.test$n.b && ret=1
+cmp -s ns2/named_dump.db.test$n.a ns2/named_dump.db.test$n.c || ret=1
+status=$((status + ret))
+
 echo_i "exit status: $status"
 [ $status -eq 0 ] || exit 1
diff --git a/lib/dns/cache.c b/lib/dns/cache.c
index f0bc00ab85a..6c070dd9c27 100644
--- a/lib/dns/cache.c
+++ b/lib/dns/cache.c
@@ -418,9 +418,7 @@ dns_cache_flushnode(dns_cache_t *cache, const dns_name_t *name, bool tree) {
 	dns_dbnode_t *node = NULL;
 	dns_db_t *db = NULL;
 
-	if (tree && dns_name_equal(name, dns_rootname)) {
-		return dns_cache_flush(cache);
-	}
+	REQUIRE(!(tree && dns_name_equal(name, dns_rootname)));
 
 	LOCK(&cache->lock);
 	if (cache->db != NULL) {
diff --git a/lib/dns/include/dns/cache.h b/lib/dns/include/dns/cache.h
index 1ac822ad717..9913a5cb6a2 100644
--- a/lib/dns/include/dns/cache.h
+++ b/lib/dns/include/dns/cache.h
@@ -200,12 +200,16 @@ dns_cache_flush(dns_cache_t *cache);
 isc_result_t
 dns_cache_flushnode(dns_cache_t *cache, const dns_name_t *name, bool tree);
 /*
- * Flush a given name from the cache.  If 'tree' is true, then
- * also flush all names under 'name'.
+ * Flush the data for node 'name' from the cache.
+ *
+ * If 'tree' is true, then also flush all nodes under 'name'. (Note that
+ * flushing of a tree only works for names below the root. To flush the
+ * entire tree, use dns_cache_flush().)
  *
  * Requires:
  *\li	'cache' to be valid.
  *\li	'name' to be valid.
+ *\li	if 'tree' is true, then 'name' is not root.
  *
  * Returns:
  *\li	#ISC_R_SUCCESS
diff --git a/lib/dns/include/dns/view.h b/lib/dns/include/dns/view.h
index 453ac9d1b06..5ef6377fd5c 100644
--- a/lib/dns/include/dns/view.h
+++ b/lib/dns/include/dns/view.h
@@ -853,10 +853,9 @@ isc_result_t
 dns_view_flushcache(dns_view_t *view, bool fixuponly);
 /*%<
  * Flush the view's cache (and ADB).  If 'fixuponly' is true, it only updates
- * the internal reference to the cache DB with omitting actual flush operation.
+ * the internal reference to the cache DB, omitting actual flush operation.
  * 'fixuponly' is intended to be used for a view that shares a cache with
- * a different view.  dns_view_flushcache() is a backward compatible version
- * that always sets fixuponly to false.
+ * a different view.
  *
  * Requires:
  * 	'view' is valid.