From: Libor Peltan <libor.peltan@nic.cz>
Date: Fri, 1 Mar 2019 12:09:32 +0000 (+0100)
Subject: Revert "reverted implementation of zone-update RCU callbacks"
X-Git-Tag: v2.9.0~286^2~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=00fa2fddd32eb6333c3699bea9f6f41ce6062993;p=thirdparty%2Fknot-dns.git

Revert "reverted implementation of zone-update RCU callbacks"

This reverts commit dbe6243d6372b4d388cda9246446d83ac4557480.
This also revers the "check unified" mechanizm which basicly was just an
assert.
---

diff --git a/src/knot/updates/zone-update.c b/src/knot/updates/zone-update.c
index 0aea0797e7..374c5d9bc9 100644
--- a/src/knot/updates/zone-update.c
+++ b/src/knot/updates/zone-update.c
@@ -680,14 +680,40 @@ static int commit_full(conf_t *conf, zone_update_t *update)
 	return ret;
 }
 
-static int check_unified(zone_node_t *node, void *data)
+/*! \brief Routine for calling call_rcu() easier way.
+ *
+ * Consider moving elsewhere, as it has no direct relation to zone-update.
+ */
+typedef struct {
+	struct rcu_head rcuhead;
+	void (*callback)(void *);
+	void *ctx;
+	bool free_ctx;
+} callrcu_wrapper_t;
+
+static void callrcu_wrapper_cb(struct rcu_head *param)
 {
-	(void)data;
-	zone_node_t *counter = binode_counterpart(node);
-	assert((node->flags ^ counter->flags) == NODE_FLAGS_SECOND);
-	assert(node->rrset_count == counter->rrset_count);
-	assert(node->rrs == counter->rrs);
-	return KNOT_EOK;
+	callrcu_wrapper_t *wrap = (callrcu_wrapper_t *)param;
+	wrap->callback(wrap->ctx);
+	if (wrap->free_ctx) {
+		free(wrap->ctx);
+	}
+	free(wrap);
+
+	// Trim extra heap.
+	mem_trim();
+}
+
+/* NOTE: Does nothing if not enough memory. */
+static void callrcu_wrapper(void *ctx, void *callback, bool free_ctx)
+{
+	callrcu_wrapper_t *wrap = calloc(1, sizeof(callrcu_wrapper_t));
+	if (wrap != NULL) {
+		wrap->callback = callback;
+		wrap->ctx = ctx;
+		wrap->free_ctx = free_ctx;
+		call_rcu((struct rcu_head *)wrap, callrcu_wrapper_cb);
+	}
 }
 
 int zone_update_commit(conf_t *conf, zone_update_t *update)
@@ -740,26 +766,21 @@ int zone_update_commit(conf_t *conf, zone_update_t *update)
 	old_contents = zone_switch_contents(update->zone, update->new_cont);
 
 	/* Sync RCU. */
-	synchronize_rcu();
 	if (update->flags & UPDATE_FULL) {
 		assert(update->new_cont_deep_copy);
-		zone_contents_deep_free(old_contents);
+		callrcu_wrapper(old_contents, zone_contents_deep_free, false);
 	} else if (update->flags & UPDATE_INCREMENTAL) {
 		if (update->new_cont_deep_copy) {
-			zone_contents_deep_free(old_contents);
+			callrcu_wrapper(old_contents, zone_contents_deep_free, false);
 		} else {
-			update_free_zone(old_contents);
+			callrcu_wrapper(old_contents, update_free_zone, false);
 		}
 		changeset_clear(&update->change);
 	}
-	update_cleanup(update->a_ctx);
-	free(update->a_ctx);
+	callrcu_wrapper(update->a_ctx, update_cleanup, true);
 	update->a_ctx = NULL;
 	update->new_cont = NULL;
 
-	zone_contents_apply(update->zone->contents, check_unified, NULL);
-	zone_contents_nsec3_apply(update->zone->contents, check_unified, NULL);
-
 	/* Sync zonefile immediately if configured. */
 	val = conf_zone_get(conf, C_ZONEFILE_SYNC, update->zone->name);
 	if (conf_int(&val) == 0) {