[PATCH] tracing: Fix file mode of free_buffer

[PATCH] tracing: Fix file mode of free_buffer

[Wang YanQing]

Commit 4f271a2a60c748599b30bb4dafff30d770439b96
(tracing: Add a proc file to stop tracing and free buffer)
implement a method to free up ring buffer in kernel memory
in the release code path of free_buffer's fd.

Then we don't need read/write support for free_buffer,
indeed we just have a dummy write fop, and don't implement read fop.

So the 0200 is more reasonable file mode for free_buffer than
the current file mode 0644.

Signed-off-by: Wang YanQing <udknight@gmail.com>
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ae6fa2d..02d9875 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
 	trace_create_file("buffer_total_size_kb", 0444, d_tracer,
 			  tr, &tracing_total_entries_fops);
 
-	trace_create_file("free_buffer", 0644, d_tracer,
+	trace_create_file("free_buffer", 0200, d_tracer,
 			  tr, &tracing_free_buffer_fops);
 
 	trace_create_file("trace_marker", 0220, d_tracer,
-- 
1.7.12.4.dirty

Re: [PATCH] tracing: Fix file mode of free_buffer

[Steven Rostedt]

David, Vaibhav,

Any comments on this patch?

-- Steve


On Sun, 2013-05-26 at 16:52 +0800, Wang YanQing wrote:
> Commit 4f271a2a60c748599b30bb4dafff30d770439b96
> (tracing: Add a proc file to stop tracing and free buffer)
> implement a method to free up ring buffer in kernel memory
> in the release code path of free_buffer's fd.
> 
> Then we don't need read/write support for free_buffer,
> indeed we just have a dummy write fop, and don't implement read fop.
> 
> So the 0200 is more reasonable file mode for free_buffer than
> the current file mode 0644.
> 
> Signed-off-by: Wang YanQing <udknight@gmail.com>
> ---
>  kernel/trace/trace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index ae6fa2d..02d9875 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
>  	trace_create_file("buffer_total_size_kb", 0444, d_tracer,
>  			  tr, &tracing_total_entries_fops);
>  
> -	trace_create_file("free_buffer", 0644, d_tracer,
> +	trace_create_file("free_buffer", 0200, d_tracer,
>  			  tr, &tracing_free_buffer_fops);
>  
>  	trace_create_file("trace_marker", 0220, d_tracer,

Re: [PATCH] tracing: Fix file mode of free_buffer

[Vaibhav Nagarnaik]

On Sun, May 26, 2013 at 1:52 AM, Wang YanQing <udknight@gmail.com> wrote:
> Commit 4f271a2a60c748599b30bb4dafff30d770439b96
> (tracing: Add a proc file to stop tracing and free buffer)
> implement a method to free up ring buffer in kernel memory
> in the release code path of free_buffer's fd.
>
> Then we don't need read/write support for free_buffer,
> indeed we just have a dummy write fop, and don't implement read fop.
>
> So the 0200 is more reasonable file mode for free_buffer than
> the current file mode 0644.
>
> Signed-off-by: Wang YanQing <udknight@gmail.com>

Acked-by: Vaibhav Nagarnaik <vnagarnaik@google.com>

Vaibhav Nagarnaik


> ---
>  kernel/trace/trace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index ae6fa2d..02d9875 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
>         trace_create_file("buffer_total_size_kb", 0444, d_tracer,
>                           tr, &tracing_total_entries_fops);
>
> -       trace_create_file("free_buffer", 0644, d_tracer,
> +       trace_create_file("free_buffer", 0200, d_tracer,
>                           tr, &tracing_free_buffer_fops);
>
>         trace_create_file("trace_marker", 0220, d_tracer,
> --
> 1.7.12.4.dirty

Re: [PATCH] tracing: Fix file mode of free_buffer

[David Sharp]

On Tue, May 28, 2013 at 12:34 PM, Vaibhav Nagarnaik
<vnagarnaik@google.com> wrote:
> On Sun, May 26, 2013 at 1:52 AM, Wang YanQing <udknight@gmail.com> wrote:
>> Commit 4f271a2a60c748599b30bb4dafff30d770439b96
>> (tracing: Add a proc file to stop tracing and free buffer)
>> implement a method to free up ring buffer in kernel memory
>> in the release code path of free_buffer's fd.
>>
>> Then we don't need read/write support for free_buffer,
>> indeed we just have a dummy write fop, and don't implement read fop.
>>
>> So the 0200 is more reasonable file mode for free_buffer than
>> the current file mode 0644.
>>
>> Signed-off-by: Wang YanQing <udknight@gmail.com>
>
> Acked-by: Vaibhav Nagarnaik <vnagarnaik@google.com>

Acked-by: David Sharp <dhsharp@google.com>

>
> Vaibhav Nagarnaik
>
>
>> ---
>>  kernel/trace/trace.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
>> index ae6fa2d..02d9875 100644
>> --- a/kernel/trace/trace.c
>> +++ b/kernel/trace/trace.c
>> @@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
>>         trace_create_file("buffer_total_size_kb", 0444, d_tracer,
>>                           tr, &tracing_total_entries_fops);
>>
>> -       trace_create_file("free_buffer", 0644, d_tracer,
>> +       trace_create_file("free_buffer", 0200, d_tracer,
>>                           tr, &tracing_free_buffer_fops);
>>
>>         trace_create_file("trace_marker", 0220, d_tracer,
>> --
>> 1.7.12.4.dirty
> --
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Re: [PATCH] tracing: Fix file mode of free_buffer

[Steven Rostedt]

On Tue, 2013-05-28 at 13:14 -0700, David Sharp wrote:
> On Tue, May 28, 2013 at 12:34 PM, Vaibhav Nagarnaik
> <vnagarnaik@google.com> wrote:
> > On Sun, May 26, 2013 at 1:52 AM, Wang YanQing <udknight@gmail.com> wrote:
> >> Commit 4f271a2a60c748599b30bb4dafff30d770439b96
> >> (tracing: Add a proc file to stop tracing and free buffer)
> >> implement a method to free up ring buffer in kernel memory
> >> in the release code path of free_buffer's fd.
> >>
> >> Then we don't need read/write support for free_buffer,
> >> indeed we just have a dummy write fop, and don't implement read fop.
> >>
> >> So the 0200 is more reasonable file mode for free_buffer than
> >> the current file mode 0644.
> >>
> >> Signed-off-by: Wang YanQing <udknight@gmail.com>
> >
> > Acked-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
> 
> Acked-by: David Sharp <dhsharp@google.com>
> 
> >

Thanks guys,

As this isn't that big of a deal, I'm going to just queue this for 3.11.

-- Steve