Don't count failed additions into the cache

Previously, when the new header was NOT added into the cache, we would
increment and then decrement stat counters immediately.

Delay incrementing the stat counters until after the newheader has
been actually added into the database.

A little cleanup to accomodate the fact that qpdb->rrsetstats is always
available was also done here.

diff --git a/lib/dns/qpcache.c b/lib/dns/qpcache.c
index c61b57a50aff74bf00d6f495cf486c379c993e79..8a2cd0387949efc20a4b16ab8a37094aca84e69f 100644 (file)
--- a/lib/dns/qpcache.c
+++ b/lib/dns/qpcache.c
@@ -843,7 +843,6 @@ mark(dns_slabheader_t *header, uint_least16_t flag) {
        uint_least16_t attributes = atomic_load_acquire(&header->attributes);
        uint_least16_t newattributes = 0;
        qpcache_t *qpdb = HEADERNODE(header)->qpdb;
-       dns_stats_t *stats = NULL;
 
        /*
         * If we are already ancient there is nothing to do.
@@ -860,9 +859,10 @@ mark(dns_slabheader_t *header, uint_least16_t flag) {
         * Decrement and increment the stats counter for the appropriate
         * RRtype.
         */
-       stats = dns_db_getrrsetstats(&qpdb->common);
-       update_rrsetstats(stats, header->typepair, attributes, false);
-       update_rrsetstats(stats, header->typepair, newattributes, true);
+       update_rrsetstats(qpdb->rrsetstats, header->typepair, attributes,
+                         false);
+       update_rrsetstats(qpdb->rrsetstats, header->typepair, newattributes,
+                         true);
 }
 
 static void
@@ -2279,9 +2279,8 @@ qpcache__destroy(qpcache_t *qpdb) {
                isc_heap_destroy(&qpdb->buckets[i].heap);
        }
 
-       if (qpdb->rrsetstats != NULL) {
-               dns_stats_detach(&qpdb->rrsetstats);
-       }
+       dns_stats_detach(&qpdb->rrsetstats);
+
        if (qpdb->cachestats != NULL) {
                isc_stats_detach(&qpdb->cachestats);
        }
@@ -3087,13 +3086,6 @@ qpcache_addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
 
        NODE_WRLOCK(nlock, &nlocktype);
 
-       if (qpdb->rrsetstats != NULL) {
-               DNS_SLABHEADER_SETATTR(newheader, DNS_SLABHEADERATTR_STATCOUNT);
-               update_rrsetstats(qpdb->rrsetstats, newheader->typepair,
-                                 atomic_load_acquire(&newheader->attributes),
-                                 true);
-       }
-
        expire_ttl_headers(qpdb, qpnode->locknum, &nlocktype, &tlocktype,
                           now DNS__DB_FLARG_PASS);
 
@@ -3117,6 +3109,10 @@ qpcache_addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
                     nlocktype, tlocktype DNS__DB_FLARG_PASS);
 
        if (result == ISC_R_SUCCESS) {
+               DNS_SLABHEADER_SETATTR(newheader, DNS_SLABHEADERATTR_STATCOUNT);
+               update_rrsetstats(qpdb->rrsetstats, newheader->typepair,
+                                 newheader->attributes, true);
+
                if (delegating) {
                        qpnode->delegating = 1;
                }