Re: [PATCH v21 26/30] splice: Convert trace/seq to use copy_splice_read()

[Steven Rostedt <rostedt@goodmis.org>]

On Sat, 20 May 2023 01:00:45 +0100
David Howells <dhowells@redhat.com> wrote:

> For the splice from the trace seq buffer, just use copy_splice_read().
> 
> In the future, something better can probably be done by gifting pages from
> seq->buf into the pipe, but that would require changing seq->buf into a
> vmap over an array of pages.
> 
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Christoph Hellwig <hch@lst.de>
> cc: Al Viro <viro@zeniv.linux.org.uk>
> cc: Jens Axboe <axboe@kernel.dk>
> cc: Steven Rostedt <rostedt@goodmis.org>
> cc: Masami Hiramatsu <mhiramat@kernel.org>
> cc: linux-kernel@vger.kernel.org
> cc: linux-trace-kernel@vger.kernel.org
> cc: linux-fsdevel@vger.kernel.org
> cc: linux-block@vger.kernel.org
> cc: linux-mm@kvack.org
> ---
>  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 ebc59781456a..c210d02fac97 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5171,7 +5171,7 @@ static const struct file_operations tracing_fops = {
>  	.open		= tracing_open,
>  	.read		= seq_read,
>  	.read_iter	= seq_read_iter,
> -	.splice_read	= generic_file_splice_read,
> +	.splice_read	= copy_splice_read,

Anyway, for this change:

Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>

-- Steve

>  	.write		= tracing_write_stub,
>  	.llseek		= tracing_lseek,
>  	.release	= tracing_release,