[PATCH v4 5/5] trace-cmd: Fix broken listener and add error checks

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

The trace-cmd listener was broken by recent changes in writing saved
command lines in the trace file. There was no error checking in that
flow, so the trace-cmd listener indicates successful trace session,
even though the output trace file was broken.
Fixed the listener logic and added more error checks.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 tracecmd/trace-listen.c | 30 ++++++++++++++++++++----------
 tracecmd/trace-record.c | 31 ++++++++++++++++++++++++++-----
 2 files changed, 46 insertions(+), 15 deletions(-)

diff --git a/tracecmd/trace-listen.c b/tracecmd/trace-listen.c
index 7798fe4f..0ae1c948 100644
--- a/tracecmd/trace-listen.c
+++ b/tracecmd/trace-listen.c
@@ -531,20 +531,22 @@ static int *create_all_readers(const char *node, const char *port,
 	return NULL;
 }
 
-static void
+static int
 collect_metadata_from_client(struct tracecmd_msg_handle *msg_handle,
 			     int ofd)
 {
 	char buf[BUFSIZ];
 	int n, s, t;
 	int ifd = msg_handle->fd;
+	int ret = 0;
 
 	do {
 		n = read(ifd, buf, BUFSIZ);
 		if (n < 0) {
 			if (errno == EINTR)
 				continue;
-			pdie("reading client");
+			ret = -errno;
+			break;
 		}
 		t = n;
 		s = 0;
@@ -553,12 +555,16 @@ collect_metadata_from_client(struct tracecmd_msg_handle *msg_handle,
 			if (s < 0) {
 				if (errno == EINTR)
 					break;
-				pdie("writing to file");
+				ret = -errno;
+				goto out;
 			}
 			t -= s;
 			s = n - t;
 		} while (t);
 	} while (n > 0 && !tracecmd_msg_done(msg_handle));
+
+out:
+	return ret;
 }
 
 static void stop_all_readers(int cpus, int *pid_array)
@@ -597,8 +603,12 @@ static int put_together_file(int cpus, int ofd, const char *node,
 	}
 
 	if (write_options) {
-		tracecmd_write_cpus(handle, cpus);
-		tracecmd_write_options(handle);
+		ret = tracecmd_write_cpus(handle, cpus);
+		if (ret)
+			goto out;
+		ret = tracecmd_write_options(handle);
+		if (ret)
+			goto out;
 	}
 	ret = tracecmd_write_cpu_data(handle, cpus, temp_files);
 
@@ -635,10 +645,9 @@ static int process_client(struct tracecmd_msg_handle *msg_handle,
 
 	/* Now we are ready to start reading data from the client */
 	if (msg_handle->version == V3_PROTOCOL)
-		tracecmd_msg_collect_data(msg_handle, ofd);
+		ret = tracecmd_msg_collect_data(msg_handle, ofd);
 	else
-		collect_metadata_from_client(msg_handle, ofd);
-
+		ret = collect_metadata_from_client(msg_handle, ofd);
 	stop_msg_handle = NULL;
 
 	/* wait a little to let our readers finish reading */
@@ -652,8 +661,9 @@ static int process_client(struct tracecmd_msg_handle *msg_handle,
 	/* wait a little to have the readers clean up */
 	sleep(1);
 
-	ret = put_together_file(cpus, ofd, node, port,
-				msg_handle->version < V3_PROTOCOL);
+	if (!ret)
+		ret = put_together_file(cpus, ofd, node, port,
+					msg_handle->version < V3_PROTOCOL);
 
 	destroy_all_readers(cpus, pid_array, node, port);
 
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 9396042d..f6131692 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -3590,22 +3590,36 @@ static void add_options(struct tracecmd_output *handle, struct common_record_con
 static struct tracecmd_msg_handle *
 setup_connection(struct buffer_instance *instance, struct common_record_context *ctx)
 {
-	struct tracecmd_msg_handle *msg_handle;
-	struct tracecmd_output *network_handle;
+	struct tracecmd_msg_handle *msg_handle = NULL;
+	struct tracecmd_output *network_handle = NULL;
+	int ret;
 
 	msg_handle = setup_network(instance);
 
 	/* Now create the handle through this socket */
 	if (msg_handle->version == V3_PROTOCOL) {
 		network_handle = tracecmd_create_init_fd_msg(msg_handle, listed_events);
+		if (!network_handle)
+			goto error;
 		tracecmd_set_quiet(network_handle, quiet);
 		add_options(network_handle, ctx);
-		tracecmd_write_cpus(network_handle, instance->cpu_count);
-		tracecmd_write_options(network_handle);
-		tracecmd_msg_finish_sending_data(msg_handle);
+		ret = tracecmd_write_cmdlines(network_handle);
+		if (ret)
+			goto error;
+		ret = tracecmd_write_cpus(network_handle, instance->cpu_count);
+		if (ret)
+			goto error;
+		ret = tracecmd_write_options(network_handle);
+		if (ret)
+			goto error;
+		ret = tracecmd_msg_finish_sending_data(msg_handle);
+		if (ret)
+			goto error;
 	} else {
 		network_handle = tracecmd_create_init_fd_glob(msg_handle->fd,
 							      listed_events);
+		if (!network_handle)
+			goto error;
 		tracecmd_set_quiet(network_handle, quiet);
 	}
 
@@ -3613,6 +3627,13 @@ setup_connection(struct buffer_instance *instance, struct common_record_context
 
 	/* OK, we are all set, let'r rip! */
 	return msg_handle;
+
+error:
+	if (msg_handle)
+		tracecmd_msg_handle_close(msg_handle);
+	if (network_handle)
+		tracecmd_output_close(network_handle);
+	return NULL;
 }
 
 static void finish_network(struct tracecmd_msg_handle *msg_handle)
-- 
2.29.2