Fix: put ctf trace ht ref. inside stream

Acked-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>

diff --git a/src/bin/lttng-relayd/lttng-relayd.h b/src/bin/lttng-relayd/lttng-relayd.h
index f264c18679d8fec1dbdc97cad9ae879ea8ffa338..6fdcca29189edb7e70583326fcebf43d7f1fa9df 100644 (file)
--- a/src/bin/lttng-relayd/lttng-relayd.h
+++ b/src/bin/lttng-relayd/lttng-relayd.h
@@ -100,7 +100,15 @@ struct relay_stream {
        uint64_t total_index_received;
        struct relay_viewer_stream *viewer_stream;
        uint64_t last_net_seq_num;
+
+       /*
+        * This node is added to the *control* connection hash table and the
+        * pointer is copied in here so we can access it when deleting this object.
+        * When deleting this, the ctf trace ht MUST NOT be destroyed. This happens
+        * at connection deletion.
+        */
        struct lttng_ht_node_str ctf_trace_node;
+       struct lttng_ht *ctf_traces_ht;
 
        /*
         * To protect from concurrent read/update between the

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index 33aad88ee3e5d0d274790dd4edef675ffeeb06db..f943488be5b94309efd332196bd52e876d2eea1a 100644 (file)
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -826,8 +826,7 @@ void deferred_free_session(struct rcu_head *head)
  * RCU read side lock MUST be acquired. If NO close_stream_check() was called
  * BEFORE the stream lock MUST be acquired.
  */
-static void destroy_stream(struct relay_stream *stream,
-               struct lttng_ht *ctf_traces_ht)
+static void destroy_stream(struct relay_stream *stream)
 {
        int delret;
        struct relay_viewer_stream *vstream;
@@ -865,7 +864,7 @@ static void destroy_stream(struct relay_stream *stream,
        delret = lttng_ht_del(relay_streams_ht, &iter);
        assert(!delret);
        iter.iter.node = &stream->ctf_trace_node.node;
-       delret = lttng_ht_del(ctf_traces_ht, &iter);
+       delret = lttng_ht_del(stream->ctf_traces_ht, &iter);
        assert(!delret);
        call_rcu(&stream->rcu_node, deferred_free_stream);
        DBG("Closed tracefile %d from close stream", stream->fd);
@@ -898,7 +897,7 @@ void relay_delete_session(struct relay_command *cmd,
                }
                stream = caa_container_of(node, struct relay_stream, stream_n);
                if (stream->session == cmd->session) {
-                       destroy_stream(stream, cmd->ctf_traces_ht);
+                       destroy_stream(stream);
                }
        }
 
@@ -1086,6 +1085,7 @@ int relay_add_stream(struct lttcomm_relayd_hdr *recv_hdr,
                stream->ctf_trace->metadata_stream = stream;
        }
        ctf_trace_assign(cmd->ctf_traces_ht, stream);
+       stream->ctf_traces_ht = cmd->ctf_traces_ht;
 
        lttng_ht_node_init_ulong(&stream->stream_n,
                        (unsigned long) stream->stream_handle);
@@ -1172,7 +1172,7 @@ int relay_close_stream(struct lttcomm_relayd_hdr *recv_hdr,
        stream->close_flag = 1;
 
        if (close_stream_check(stream)) {
-               destroy_stream(stream, cmd->ctf_traces_ht);
+               destroy_stream(stream);
        }
 
 end_unlock:
@@ -2088,7 +2088,7 @@ int relay_process_data(struct relay_command *cmd)
 
        /* Check if we need to close the FD */
        if (close_stream_check(stream)) {
-               destroy_stream(stream, cmd->ctf_traces_ht);
+               destroy_stream(stream);
        }
 
 end_rcu_unlock:
@@ -2130,9 +2130,17 @@ int relay_add_connection(int fd, struct lttng_poll_event *events,
                goto error_read;
        }
 
-       relay_connection->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
-       if (!relay_connection->ctf_traces_ht) {
-               goto error_read;
+       /*
+        * Only used by the control side and the reference is copied inside each
+        * stream from that connection. Thus a destroy HT must be done after every
+        * stream has been destroyed.
+        */
+       if (relay_connection->type == RELAY_CONTROL) {
+               relay_connection->ctf_traces_ht = lttng_ht_new(0,
+                               LTTNG_HT_TYPE_STRING);
+               if (!relay_connection->ctf_traces_ht) {
+                       goto error_read;
+               }
        }
 
        lttng_ht_node_init_ulong(&relay_connection->sock_n,
@@ -2157,7 +2165,6 @@ void deferred_free_connection(struct rcu_head *head)
        struct relay_command *relay_connection =
                caa_container_of(head, struct relay_command, rcu_node);
 
-       lttng_ht_destroy(relay_connection->ctf_traces_ht);
        lttcomm_destroy_sock(relay_connection->sock);
        free(relay_connection);
 }
@@ -2171,12 +2178,13 @@ void relay_del_connection(struct lttng_ht *relay_connections_ht,
 
        ret = lttng_ht_del(relay_connections_ht, iter);
        assert(!ret);
+
        if (relay_connection->type == RELAY_CONTROL) {
                relay_delete_session(relay_connection, sessions_ht);
+               lttng_ht_destroy(relay_connection->ctf_traces_ht);
        }
 
-       call_rcu(&relay_connection->rcu_node,
-               deferred_free_connection);
+       call_rcu(&relay_connection->rcu_node, deferred_free_connection);
 }
 
 /*