X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-registry.c;h=7250dd12d751b0edcce93ffd4b886f8bdd7c7395;hp=19cff09fcd9d26aedb4a79194d10f7875e5fc810;hb=36b588eddce05ef840bd247f6a58316925b9a0a2;hpb=7972aab22f74b18faa168c0482216a3dd711a075

diff --git a/src/bin/lttng-sessiond/ust-registry.c b/src/bin/lttng-sessiond/ust-registry.c
index 19cff09fc..7250dd12d 100644
--- a/src/bin/lttng-sessiond/ust-registry.c
+++ b/src/bin/lttng-sessiond/ust-registry.c
@@ -308,12 +308,26 @@ void ust_registry_destroy_event(struct ust_registry_channel *chan,
 	return;
 }
 
+/*
+ * We need to execute ht_destroy outside of RCU read-side critical
+ * section, so we postpone its execution using call_rcu. It is simpler
+ * than to change the semantic of the many callers of
+ * destroy_channel().
+ */
+static
+void destroy_channel_rcu(struct rcu_head *head)
+{
+	struct ust_registry_channel *chan =
+		caa_container_of(head, struct ust_registry_channel, rcu_head);
+
+	lttng_ht_destroy(chan->ht);
+	free(chan);
+}
+
 /*
  * Destroy every element of the registry and free the memory. This does NOT
  * free the registry pointer since it might not have been allocated before so
  * it's the caller responsability.
- *
- * This MUST be called within a RCU read side lock section.
  */
 static void destroy_channel(struct ust_registry_channel *chan)
 {
@@ -322,14 +336,14 @@ static void destroy_channel(struct ust_registry_channel *chan)
 
 	assert(chan);
 
+	rcu_read_lock();
 	/* Destroy all event associated with this registry. */
 	cds_lfht_for_each_entry(chan->ht->ht, &iter.iter, event, node.node) {
 		/* Delete the node from the ht and free it. */
 		ust_registry_destroy_event(chan, event);
 	}
-	lttng_ht_destroy(chan->ht);
-
-	free(chan);
+	rcu_read_unlock();
+	call_rcu(&chan->rcu_head, destroy_channel_rcu);
 }
 
 /*
@@ -418,22 +432,24 @@ void ust_registry_channel_del_free(struct ust_registry_session *session,
 {
 	struct lttng_ht_iter iter;
 	struct ust_registry_channel *chan;
+	int ret;
 
 	assert(session);
 
 	rcu_read_lock();
 	chan = ust_registry_channel_find(session, key);
 	if (!chan) {
+		rcu_read_unlock();
 		goto end;
 	}
 
 	iter.iter.node = &chan->node.node;
-	lttng_ht_del(session->channels, &iter);
-
+	ret = lttng_ht_del(session->channels, &iter);
+	assert(!ret);
+	rcu_read_unlock();
 	destroy_channel(chan);
 
 end:
-	rcu_read_unlock();
 	return;
 }
 
@@ -452,13 +468,14 @@ int ust_registry_session_init(struct ust_registry_session **sessionp,
 		uint32_t uint32_t_alignment,
 		uint32_t uint64_t_alignment,
 		uint32_t long_alignment,
-		int byte_order)
+		int byte_order,
+		uint32_t major,
+		uint32_t minor)
 {
 	int ret;
 	struct ust_registry_session *session;
 
 	assert(sessionp);
-	assert(app);
 
 	session = zmalloc(sizeof(*session));
 	if (!session) {
@@ -487,7 +504,7 @@ int ust_registry_session_init(struct ust_registry_session **sessionp,
 	}
 
 	pthread_mutex_lock(&session->lock);
-	ret = ust_metadata_session_statedump(session, app);
+	ret = ust_metadata_session_statedump(session, app, major, minor);
 	pthread_mutex_unlock(&session->lock);
 	if (ret) {
 		ERR("Failed to generate session metadata (errno = %d)", ret);
@@ -524,8 +541,8 @@ void ust_registry_session_destroy(struct ust_registry_session *reg)
 		assert(!ret);
 		destroy_channel(chan);
 	}
-	lttng_ht_destroy(reg->channels);
 	rcu_read_unlock();
 
+	lttng_ht_destroy(reg->channels);
 	free(reg->metadata);
 }