Fix: relayd: fully initialize viewer stream before publishing it

[lttng-tools.git] / src / bin / lttng-relayd / viewer-stream.c

diff --git a/src/bin/lttng-relayd/viewer-stream.c b/src/bin/lttng-relayd/viewer-stream.c
index 8a3b09a92060ef25e9f9f8f50b2d36d15c2de159..acd488b61846202813e8a7efe07898c1f67cfef7 100644 (file)
--- a/src/bin/lttng-relayd/viewer-stream.c
+++ b/src/bin/lttng-relayd/viewer-stream.c
@@ -41,9 +41,16 @@ static void viewer_stream_destroy_rcu(struct rcu_head *head)
 }
 
 struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
+               struct lttng_trace_chunk *viewer_trace_chunk,
                enum lttng_viewer_seek seek_t)
 {
-       struct relay_viewer_stream *vstream;
+       struct relay_viewer_stream *vstream = NULL;
+       const bool acquired_reference = lttng_trace_chunk_get(
+                       viewer_trace_chunk);
+
+       if (!acquired_reference) {
+               goto error;
+       }
 
        vstream = zmalloc(sizeof(*vstream));
        if (!vstream) {
@@ -51,6 +58,8 @@ struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
                goto error;
        }
 
+       vstream->stream_file.trace_chunk = viewer_trace_chunk;
+       viewer_trace_chunk = NULL;
        vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
        if (vstream->path_name == NULL) {
                PERROR("relay viewer path_name alloc");
@@ -96,7 +105,7 @@ struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
        }
        case LTTNG_VIEWER_SEEK_LAST:
                vstream->current_tracefile_id =
-                       tracefile_array_get_file_index_head(stream->tfa);
+                       tracefile_array_get_read_file_index_head(stream->tfa);
                /*
                 * We seek at the very end of each stream, awaiting for
                 * a future packet to eventually come in.
@@ -118,10 +127,18 @@ struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
        if (stream->index_received_seqcount == 0) {
                vstream->index_file = NULL;
        } else {
-               vstream->index_file = lttng_index_file_open(vstream->path_name,
-                               vstream->channel_name,
-                               stream->tracefile_count,
-                               vstream->current_tracefile_id);
+               const uint32_t connection_major = stream->trace->session->major;
+               const uint32_t connection_minor = stream->trace->session->minor;
+
+               vstream->index_file = lttng_index_file_create_from_trace_chunk_read_only(
+                               vstream->stream_file.trace_chunk,
+                               stream->path_name,
+                               stream->channel_name, stream->tracefile_size,
+                               vstream->current_tracefile_id,
+                               lttng_to_index_major(connection_major,
+                                               connection_minor),
+                               lttng_to_index_minor(connection_major,
+                                               connection_minor));
                if (!vstream->index_file) {
                        goto error_unlock;
                }
@@ -143,10 +160,8 @@ struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
 
        /* Globally visible after the add unique. */
        lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
-       lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
-
-       pthread_mutex_init(&vstream->reflock, NULL);
        urcu_ref_init(&vstream->ref);
+       lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
 
        return vstream;
 
@@ -156,6 +171,9 @@ error:
        if (vstream) {
                viewer_stream_destroy(vstream);
        }
+       if (viewer_trace_chunk && acquired_reference) {
+               lttng_trace_chunk_put(viewer_trace_chunk);
+       }
        return NULL;
 }
 
@@ -180,9 +198,9 @@ static void viewer_stream_release(struct urcu_ref *ref)
 
        viewer_stream_unpublish(vstream);
 
-       if (vstream->stream_fd) {
-               stream_fd_put(vstream->stream_fd);
-               vstream->stream_fd = NULL;
+       if (vstream->stream_file.fd) {
+               stream_fd_put(vstream->stream_file.fd);
+               vstream->stream_file.fd = NULL;
        }
        if (vstream->index_file) {
                lttng_index_file_put(vstream->index_file);
@@ -192,22 +210,15 @@ static void viewer_stream_release(struct urcu_ref *ref)
                stream_put(vstream->stream);
                vstream->stream = NULL;
        }
+       lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
+       vstream->stream_file.trace_chunk = NULL;
        call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
 }
 
 /* Must be called with RCU read-side lock held. */
 bool viewer_stream_get(struct relay_viewer_stream *vstream)
 {
-       bool has_ref = false;
-
-       pthread_mutex_lock(&vstream->reflock);
-       if (vstream->ref.refcount != 0) {
-               has_ref = true;
-               urcu_ref_get(&vstream->ref);
-       }
-       pthread_mutex_unlock(&vstream->reflock);
-
-       return has_ref;
+       return urcu_ref_get_unless_zero(&vstream->ref);
 }
 
 /*
@@ -240,9 +251,7 @@ end:
 void viewer_stream_put(struct relay_viewer_stream *vstream)
 {
        rcu_read_lock();
-       pthread_mutex_lock(&vstream->reflock);
        urcu_ref_put(&vstream->ref, viewer_stream_release);
-       pthread_mutex_unlock(&vstream->reflock);
        rcu_read_unlock();
 }
 
@@ -255,8 +264,10 @@ void viewer_stream_put(struct relay_viewer_stream *vstream)
 int viewer_stream_rotate(struct relay_viewer_stream *vstream)
 {
        int ret;
-       struct relay_stream *stream = vstream->stream;
        uint64_t new_id;
+       const struct relay_stream *stream = vstream->stream;
+       const uint32_t connection_major = stream->trace->session->major;
+       const uint32_t connection_minor = stream->trace->session->minor;
 
        /* Detect the last tracefile to open. */
        if (stream->index_received_seqcount
@@ -301,15 +312,21 @@ int viewer_stream_rotate(struct relay_viewer_stream *vstream)
                lttng_index_file_put(vstream->index_file);
                vstream->index_file = NULL;
        }
-       if (vstream->stream_fd) {
-               stream_fd_put(vstream->stream_fd);
-               vstream->stream_fd = NULL;
+       if (vstream->stream_file.fd) {
+               stream_fd_put(vstream->stream_file.fd);
+               vstream->stream_file.fd = NULL;
        }
-
-       vstream->index_file = lttng_index_file_open(vstream->path_name,
-                       vstream->channel_name,
-                       stream->tracefile_count,
-                       vstream->current_tracefile_id);
+       vstream->index_file =
+                       lttng_index_file_create_from_trace_chunk_read_only(
+                                       vstream->stream_file.trace_chunk,
+                                       stream->path_name,
+                                       stream->channel_name,
+                                       stream->tracefile_size,
+                                       vstream->current_tracefile_id,
+                                       lttng_to_index_major(connection_major,
+                                                       connection_minor),
+                                       lttng_to_index_minor(connection_major,
+                                                       connection_minor));
        if (!vstream->index_file) {
                ret = -1;
                goto end;