[PATCH v2] tracing: Use trace_create_file() to simplify creation of tracefs entries

From: Yuntao Wang
Date: Thu Jan 13 2022 - 20:11:42 EST


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.

Signed-off-by: Yuntao Wang <ytcoode@xxxxxxxxx>
---
Changes since v1:
- Remove format change updates

kernel/trace/ftrace.c | 8 +++-----
kernel/trace/trace_dynevent.c | 8 ++------
kernel/trace/trace_events.c | 29 +++++++++------------------
kernel/trace/trace_kprobe.c | 14 ++++---------
kernel/trace/trace_recursion_record.c | 7 ++-----
5 files changed, 21 insertions(+), 45 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 403e485bf091..83072cd9bdca 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -983,11 +983,9 @@ 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 */
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index e34e8182ee4b..6f6ee1d9e247 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -262,12 +262,8 @@ static __init int init_dynamic_event(void)
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;
}
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 3147614c1812..718518b3c491 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -3446,12 +3446,10 @@ 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) {
@@ -3466,16 +3464,12 @@ 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,
@@ -3690,17 +3684,14 @@ 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)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 3d85323278ed..d13826ea490b 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1912,19 +1912,13 @@ static __init int init_kprobe_trace(void)
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();

diff --git a/kernel/trace/trace_recursion_record.c b/kernel/trace/trace_recursion_record.c
index 4d4b78c8ca25..a520b11afb0d 100644
--- a/kernel/trace/trace_recursion_record.c
+++ b/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;
}

--
2.34.1