Fix: multiple consumer locking problems

[lttng-tools.git] / src / common / consumer.c

diff --git a/src/common/consumer.c b/src/common/consumer.c
index deebd2e2b353cd1cc4365f5ede45e78203e9653e..c1dadddb3dd08854bffd8eef8cca3e9a76e82bed 100644 (file)
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -274,9 +274,12 @@ void consumer_del_stream(struct lttng_consumer_stream *stream)
                uatomic_dec(&relayd->refcount);
                assert(uatomic_read(&relayd->refcount) >= 0);
 
+               /* Closing streams requires to lock the control socket. */
+               pthread_mutex_lock(&relayd->ctrl_sock_mutex);
                ret = relayd_send_close_stream(&relayd->control_sock,
                                stream->relayd_stream_id,
                                stream->next_net_seq_num - 1);
+               pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
                if (ret < 0) {
                        DBG("Unable to close stream on the relayd. Continuing");
                        /*
@@ -438,8 +441,10 @@ end:
 }
 
 /*
- * Add relayd socket to global consumer data hashtable.
+ * Add relayd socket to global consumer data hashtable. RCU read side lock MUST
+ * be acquired before calling this.
  */
+
 int consumer_add_relayd(struct consumer_relayd_sock_pair *relayd)
 {
        int ret = 0;
@@ -451,20 +456,15 @@ int consumer_add_relayd(struct consumer_relayd_sock_pair *relayd)
                goto end;
        }
 
-       rcu_read_lock();
-
        lttng_ht_lookup(consumer_data.relayd_ht,
                        (void *)((unsigned long) relayd->net_seq_idx), &iter);
        node = lttng_ht_iter_get_node_ulong(&iter);
        if (node != NULL) {
-               rcu_read_unlock();
                /* Relayd already exist. Ignore the insertion */
                goto end;
        }
        lttng_ht_add_unique_ulong(consumer_data.relayd_ht, &relayd->node);
 
-       rcu_read_unlock();
-
 end:
        return ret;
 }