tracing: Use trace_create_file() to simplify creation of tracefs entries

Creating tracefs entries with tracefs_create_file() followed by pr_warn()
is tedious and repetitive, we can use trace_create_file() to simplify
this process and make the code more readable.

Link: https://lkml.kernel.org/r/20220114131052.534382-1-ytcoode@gmail.comAcked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/ftrace.c

@@ -952,7 +952,6 @@ static struct tracer_stat function_stats __initdata = {
 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
 {
 	struct ftrace_profile_stat *stat;
-	struct dentry *entry;
 	char *name;
 	int ret;
 	int cpu;
@@ -983,11 +982,9 @@ static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
 		}
 	}
 
-	entry = tracefs_create_file("function_profile_enabled",
-				    TRACE_MODE_WRITE, d_tracer, NULL,
-				    &ftrace_profile_fops);
-	if (!entry)
-		pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
+	trace_create_file("function_profile_enabled",
+			  TRACE_MODE_WRITE, d_tracer, NULL,
+			  &ftrace_profile_fops);
 }
 
 #else /* CONFIG_FUNCTION_PROFILER */

kernel/trace/trace_dynevent.c

@@ -255,19 +255,14 @@ static const struct file_operations dynamic_events_ops = {
 /* Make a tracefs interface for controlling dynamic events */
 static __init int init_dynamic_event(void)
 {
-	struct dentry *entry;
 	int ret;
 
 	ret = tracing_init_dentry();
 	if (ret)
 		return 0;
 
-	entry = tracefs_create_file("dynamic_events", TRACE_MODE_WRITE, NULL,
-				    NULL, &dynamic_events_ops);
-
-	/* Event list interface */
-	if (!entry)
-		pr_warn("Could not create tracefs 'dynamic_events' entry\n");
+	trace_create_file("dynamic_events", TRACE_MODE_WRITE, NULL,
+			  NULL, &dynamic_events_ops);
 
 	return 0;
 }

kernel/trace/trace_events.c

@@ -3546,12 +3546,10 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
 	struct dentry *d_events;
 	struct dentry *entry;
 
-	entry = tracefs_create_file("set_event", TRACE_MODE_WRITE, parent,
-				    tr, &ftrace_set_event_fops);
-	if (!entry) {
-		pr_warn("Could not create tracefs 'set_event' entry\n");
+	entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent,
+				  tr, &ftrace_set_event_fops);
+	if (!entry)
 		return -ENOMEM;
-	}
 
 	d_events = tracefs_create_dir("events", parent);
 	if (!d_events) {
@@ -3566,16 +3564,12 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
 
 	/* There are not as crucial, just warn if they are not created */
 
-	entry = tracefs_create_file("set_event_pid", TRACE_MODE_WRITE, parent,
-				    tr, &ftrace_set_event_pid_fops);
-	if (!entry)
-		pr_warn("Could not create tracefs 'set_event_pid' entry\n");
+	trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent,
+			  tr, &ftrace_set_event_pid_fops);
 
-	entry = tracefs_create_file("set_event_notrace_pid",
-				    TRACE_MODE_WRITE, parent, tr,
-				    &ftrace_set_event_notrace_pid_fops);
-	if (!entry)
-		pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n");
+	trace_create_file("set_event_notrace_pid",
+			  TRACE_MODE_WRITE, parent, tr,
+			  &ftrace_set_event_notrace_pid_fops);
 
 	/* ring buffer internal formats */
 	trace_create_file("header_page", TRACE_MODE_READ, d_events,
@@ -3790,17 +3784,14 @@ static __init int event_trace_init_fields(void)
 __init int event_trace_init(void)
 {
 	struct trace_array *tr;
-	struct dentry *entry;
 	int ret;
 
 	tr = top_trace_array();
 	if (!tr)
 		return -ENODEV;
 
-	entry = tracefs_create_file("available_events", TRACE_MODE_READ,
-				    NULL, tr, &ftrace_avail_fops);
-	if (!entry)
-		pr_warn("Could not create tracefs 'available_events' entry\n");
+	trace_create_file("available_events", TRACE_MODE_READ,
+			  NULL, tr, &ftrace_avail_fops);
 
 	ret = early_event_add_tracer(NULL, tr);
 	if (ret)

kernel/trace/trace_kprobe.c

@@ -1907,25 +1907,18 @@ core_initcall(init_kprobe_trace_early);
 static __init int init_kprobe_trace(void)
 {
 	int ret;
-	struct dentry *entry;
 
 	ret = tracing_init_dentry();
 	if (ret)
 		return 0;
 
-	entry = tracefs_create_file("kprobe_events", TRACE_MODE_WRITE,
-				    NULL, NULL, &kprobe_events_ops);
-
 	/* Event list interface */
-	if (!entry)
-		pr_warn("Could not create tracefs 'kprobe_events' entry\n");
+	trace_create_file("kprobe_events", TRACE_MODE_WRITE,
+			  NULL, NULL, &kprobe_events_ops);
 
 	/* Profile interface */
-	entry = tracefs_create_file("kprobe_profile", TRACE_MODE_READ,
-				    NULL, NULL, &kprobe_profile_ops);
-
-	if (!entry)
-		pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
+	trace_create_file("kprobe_profile", TRACE_MODE_READ,
+			  NULL, NULL, &kprobe_profile_ops);
 
 	setup_boot_kprobe_events();
 

kernel/trace/trace_recursion_record.c

@@ -224,12 +224,9 @@ static const struct file_operations recursed_functions_fops = {
 
 __init static int create_recursed_functions(void)
 {
-	struct dentry *dentry;
 
-	dentry = trace_create_file("recursed_functions", TRACE_MODE_WRITE,
-				   NULL, NULL, &recursed_functions_fops);
-	if (!dentry)
-		pr_warn("WARNING: Failed to create recursed_functions\n");
+	trace_create_file("recursed_functions", TRACE_MODE_WRITE,
+			  NULL, NULL, &recursed_functions_fops);
 	return 0;
 }