Fix: don't steal key when adding a metadata stream

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

diff --git a/src/common/consumer.c b/src/common/consumer.c
index dbec177b7328468b278d0205598e04c574609b53..260779ae6d1ace6d9a186c40c2202a654c85dbea 100644 (file)
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -554,6 +554,7 @@ static int consumer_add_stream(struct lttng_consumer_stream *stream,
        DBG3("Adding consumer stream %d", stream->key);
 
        pthread_mutex_lock(&consumer_data.lock);
+       pthread_mutex_lock(&stream->lock);
        rcu_read_lock();
 
        /* Steal stream identifier to avoid having streams with the same key */
@@ -593,6 +594,7 @@ static int consumer_add_stream(struct lttng_consumer_stream *stream,
        consumer_data.need_update = 1;
 
        rcu_read_unlock();
+       pthread_mutex_unlock(&stream->lock);
        pthread_mutex_unlock(&consumer_data.lock);
 
        return ret;
@@ -1872,6 +1874,8 @@ static int consumer_add_metadata_stream(struct lttng_consumer_stream *stream,
 {
        int ret = 0;
        struct consumer_relayd_sock_pair *relayd;
+       struct lttng_ht_iter iter;
+       struct lttng_ht_node_ulong *node;
 
        assert(stream);
        assert(ht);
@@ -1879,6 +1883,7 @@ static int consumer_add_metadata_stream(struct lttng_consumer_stream *stream,
        DBG3("Adding metadata stream %d to hash table", stream->wait_fd);
 
        pthread_mutex_lock(&consumer_data.lock);
+       pthread_mutex_lock(&stream->lock);
 
        /*
         * From here, refcounts are updated so be _careful_ when returning an error
@@ -1886,6 +1891,15 @@ static int consumer_add_metadata_stream(struct lttng_consumer_stream *stream,
         */
 
        rcu_read_lock();
+
+       /*
+        * Lookup the stream just to make sure it does not exist in our internal
+        * state. This should NEVER happen.
+        */
+       lttng_ht_lookup(ht, (void *)((unsigned long) stream->wait_fd), &iter);
+       node = lttng_ht_iter_get_node_ulong(&iter);
+       assert(!node);
+
        /* Find relayd and, if one is found, increment refcount. */
        relayd = consumer_find_relayd(stream->net_seq_idx);
        if (relayd != NULL) {
@@ -1906,9 +1920,6 @@ static int consumer_add_metadata_stream(struct lttng_consumer_stream *stream,
                uatomic_dec(&stream->chan->nb_init_streams);
        }
 
-       /* Steal stream identifier to avoid having streams with the same key */
-       consumer_steal_stream_key(stream->key, ht);
-
        lttng_ht_add_unique_ulong(ht, &stream->node);
 
        /*
@@ -1920,6 +1931,7 @@ static int consumer_add_metadata_stream(struct lttng_consumer_stream *stream,
 
        rcu_read_unlock();
 
+       pthread_mutex_unlock(&stream->lock);
        pthread_mutex_unlock(&consumer_data.lock);
        return ret;
 }