trace: split trace_init_file out of trace_init_backends

This is cleaner, and improves error reporting with -daemonize.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-4-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 12 insertions, 5 deletions

diff --git a/trace/control.c b/trace/control.c
index 931d64c0c8..f5a497a391 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -145,17 +145,24 @@ void trace_init_events(const char *fname)
     loc_pop(&loc);
 }
 
-bool trace_init_backends(const char *file)
+void trace_init_file(const char *file)
 {
 #ifdef CONFIG_TRACE_SIMPLE
-    if (!st_init(file)) {
-        fprintf(stderr, "failed to initialize simple tracing backend.\n");
-        return false;
-    }
+    st_set_trace_file(file);
 #else
     if (file) {
         fprintf(stderr, "error: -trace file=...: "
                 "option not supported by the selected tracing backends\n");
+        exit(1);
+    }
+#endif
+}
+
+bool trace_init_backends(void)
+{
+#ifdef CONFIG_TRACE_SIMPLE
+    if (!st_init()) {
+        fprintf(stderr, "failed to initialize simple tracing backend.\n");
         return false;
     }
 #endif