tracing: Move trace_flags from global to a trace_array field

In preparation to make trace options per instance, the global trace_flags
needs to be moved from being a global variable to a field within the trace
instance trace_array structure.

There's still more work to do, as there's some functions that use
trace_flags without passing in a way to get to the current_trace array. For
those, the global_trace is used directly (from trace.c). This includes
setting and clearing the trace_flags. This means that when a new instance is
created, it just gets the trace_flags of the global_trace and will not be
able to modify them. Depending on the functions that have access to the
trace_array, the flags of an instance may not affect parts of its trace,
where the global_trace is used. These will be fixed in future changes.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace_events.c

@@ -338,6 +338,7 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
 					 int enable, int soft_disable)
 {
 	struct trace_event_call *call = file->event_call;
+	struct trace_array *tr = file->tr;
 	int ret = 0;
 	int disable;
 
@@ -401,7 +402,7 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
 			if (soft_disable)
 				set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
 
-			if (trace_flags & TRACE_ITER_RECORD_CMD) {
+			if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
 				tracing_start_cmdline_record();
 				set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
 			}