Re: [PATCH] tracing: Use trace_create_file() to simplify creation of tracefs entry

From: Steven Rostedt
Date: Thu Jan 13 2022 - 14:23:25 EST


On Fri, 14 Jan 2022 00:25:13 +0800
Yuntao Wang <ytcoode@xxxxxxxxx> wrote:

> 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>
> ---
> kernel/trace/ftrace.c | 17 +++++-------
> kernel/trace/trace.c | 16 ++++++------
> kernel/trace/trace_dynevent.c | 8 ++----
> kernel/trace/trace_events.c | 37 ++++++++++-----------------
> kernel/trace/trace_hwlat.c | 2 +-
> kernel/trace/trace_kprobe.c | 14 +++-------
> kernel/trace/trace_osnoise.c | 2 +-
> kernel/trace/trace_printk.c | 2 +-
> kernel/trace/trace_recursion_record.c | 7 ++---
> kernel/trace/trace_stack.c | 4 +--
> kernel/trace/trace_uprobe.c | 4 +--
> 11 files changed, 44 insertions(+), 69 deletions(-)
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 403e485bf091..3c5e3838772d 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 */
> @@ -6366,11 +6364,10 @@ static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
>
> #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer,
> - NULL,
> - &ftrace_graph_fops);
> + NULL, &ftrace_graph_fops);
> +
> trace_create_file("set_graph_notrace", TRACE_MODE_WRITE, d_tracer,
> - NULL,
> - &ftrace_graph_notrace_fops);
> + NULL, &ftrace_graph_notrace_fops);

What's with all the format change updates?

Could you resend with just the code changes? There's no reason to update
white space where the code isn't being touched.

Thanks,

-- Steve


> #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
>
> return 0;
> @@ -7744,7 +7741,7 @@ static const struct file_operations ftrace_no_pid_fops = {
> void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
> {
> trace_create_file("set_ftrace_pid", TRACE_MODE_WRITE, d_tracer,
> - tr, &ftrace_pid_fops);
> + tr, &ftrace_pid_fops);
> trace_create_file("set_ftrace_notrace_pid", TRACE_MODE_WRITE,
> d_tracer, tr, &ftrace_no_pid_fops);
> }
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index a73d78dcda2c..5d66e79f43e7 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -9422,10 +9422,10 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
> int cpu;
>
> trace_create_file("available_tracers", TRACE_MODE_READ, d_tracer,
> - tr, &show_traces_fops);
> + tr, &show_traces_fops);
>
> trace_create_file("current_tracer", TRACE_MODE_WRITE, d_tracer,
> - tr, &set_tracer_fops);
> + tr, &set_tracer_fops);
>
> trace_create_file("tracing_cpumask", TRACE_MODE_WRITE, d_tracer,
> tr, &tracing_cpumask_fops);
> @@ -9472,7 +9472,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
> tr->buffer_percent = 50;
>
> trace_create_file("buffer_percent", TRACE_MODE_READ, d_tracer,
> - tr, &buffer_percent_fops);
> + tr, &buffer_percent_fops);
>
> create_trace_options_dir(tr);
>
> @@ -9680,19 +9680,19 @@ static __init int tracer_init_tracefs(void)
> ftrace_init_tracefs_toplevel(&global_trace, NULL);
>
> trace_create_file("tracing_thresh", TRACE_MODE_WRITE, NULL,
> - &global_trace, &tracing_thresh_fops);
> + &global_trace, &tracing_thresh_fops);
>
> trace_create_file("README", TRACE_MODE_READ, NULL,
> - NULL, &tracing_readme_fops);
> + NULL, &tracing_readme_fops);
>
> trace_create_file("saved_cmdlines", TRACE_MODE_READ, NULL,
> - NULL, &tracing_saved_cmdlines_fops);
> + NULL, &tracing_saved_cmdlines_fops);
>
> trace_create_file("saved_cmdlines_size", TRACE_MODE_WRITE, NULL,
> NULL, &tracing_saved_cmdlines_size_fops);
>
> trace_create_file("saved_tgids", TRACE_MODE_READ, NULL,
> - NULL, &tracing_saved_tgids_fops);
> + NULL, &tracing_saved_tgids_fops);
>
> trace_eval_init();
>
> @@ -9704,7 +9704,7 @@ static __init int tracer_init_tracefs(void)
>
> #ifdef CONFIG_DYNAMIC_FTRACE
> trace_create_file("dyn_ftrace_total_info", TRACE_MODE_READ, NULL,
> - NULL, &tracing_dyn_info_fops);
> + NULL, &tracing_dyn_info_fops);
> #endif
>
> create_trace_instances(NULL);
> 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..408f8a8a7723 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) {
> @@ -3466,25 +3464,21 @@ 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,
> - ring_buffer_print_page_header,
> - &ftrace_show_header_fops);
> + ring_buffer_print_page_header,
> + &ftrace_show_header_fops);
>
> trace_create_file("header_event", TRACE_MODE_READ, d_events,
> - ring_buffer_print_entry_header,
> - &ftrace_show_header_fops);
> + ring_buffer_print_entry_header,
> + &ftrace_show_header_fops);
>
> tr->event_dir = 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_hwlat.c b/kernel/trace/trace_hwlat.c
> index 56bb7b890578..7bab09a6bd0a 100644
> --- a/kernel/trace/trace_hwlat.c
> +++ b/kernel/trace/trace_hwlat.c
> @@ -796,7 +796,7 @@ static int init_tracefs(void)
> if (!hwlat_sample_width)
> goto err;
>
> - hwlat_thread_mode = trace_create_file("mode", TRACE_MODE_WRITE,
> + hwlat_thread_mode = tracefs_create_file("mode", TRACE_MODE_WRITE,
> top_dir,
> NULL,
> &thread_mode_fops);
> 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_osnoise.c b/kernel/trace/trace_osnoise.c
> index 36d9d5be08b4..d0aa23bcbf85 100644
> --- a/kernel/trace/trace_osnoise.c
> +++ b/kernel/trace/trace_osnoise.c
> @@ -2075,7 +2075,7 @@ static int init_tracefs(void)
> if (!tmp)
> goto err;
>
> - tmp = trace_create_file("cpus", TRACE_MODE_WRITE, top_dir, NULL, &cpus_fops);
> + tmp = tracefs_create_file("cpus", TRACE_MODE_WRITE, top_dir, NULL, &cpus_fops);
> if (!tmp)
> goto err;
>
> diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
> index 29f6e95439b6..5422ac74537a 100644
> --- a/kernel/trace/trace_printk.c
> +++ b/kernel/trace/trace_printk.c
> @@ -385,7 +385,7 @@ static __init int init_trace_printk_function_export(void)
> return 0;
>
> trace_create_file("printk_formats", TRACE_MODE_READ, NULL,
> - NULL, &ftrace_formats_fops);
> + NULL, &ftrace_formats_fops);
>
> return 0;
> }
> 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;
> }
>
> diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
> index 5a48dba912ea..2337470e9ae0 100644
> --- a/kernel/trace/trace_stack.c
> +++ b/kernel/trace/trace_stack.c
> @@ -560,10 +560,10 @@ static __init int stack_trace_init(void)
> return 0;
>
> trace_create_file("stack_max_size", TRACE_MODE_WRITE, NULL,
> - &stack_trace_max_size, &stack_max_size_fops);
> + &stack_trace_max_size, &stack_max_size_fops);
>
> trace_create_file("stack_trace", TRACE_MODE_READ, NULL,
> - NULL, &stack_trace_fops);
> + NULL, &stack_trace_fops);
>
> #ifdef CONFIG_DYNAMIC_FTRACE
> trace_create_file("stack_trace_filter", TRACE_MODE_WRITE, NULL,
> diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
> index 08b0e8417302..58feb4ab34d1 100644
> --- a/kernel/trace/trace_uprobe.c
> +++ b/kernel/trace/trace_uprobe.c
> @@ -1652,10 +1652,10 @@ static __init int init_uprobe_trace(void)
> return 0;
>
> trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
> - NULL, &uprobe_events_ops);
> + NULL, &uprobe_events_ops);
> /* Profile interface */
> trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
> - NULL, &uprobe_profile_ops);
> + NULL, &uprobe_profile_ops);
> return 0;
> }
>