Commit c7625a55 authored Apr 02, 2009 by Lai Jiangshan Committed by Ingo Molnar Apr 10, 2009

tracing: update file->f_pos when splice(2) it



Impact: Cleanup

These two lines:

	if (unlikely(*ppos))
		return -ESPIPE;

in tracing_buffers_splice_read() are not needed, VFS layer
has disabled seek(2).

We remove these two lines, and then we can update file->f_pos.

And tracing_buffers_read() updates file->f_pos, this fix
make tracing_buffers_splice_read() updates file->f_pos too.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <49D46670.4010503@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent ddd538f3

kernel/trace/trace.c

+1 −7

Original line number	Diff line number	Diff line
		@@ -3428,13 +3428,6 @@ tracing_buffers_splice_read(struct file file, loff_t ppos,
		int size, i;
		size_t ret;

		/*
		* We can't seek on a buffer input
		*/
		if (unlikely(*ppos))
		return -ESPIPE;


		for (i = 0; i < PIPE_BUFFERS && len; i++, len -= size) {
		struct page *page;
		int r;
		@@ -3474,6 +3467,7 @@ tracing_buffers_splice_read(struct file file, loff_t ppos,
		spd.partial[i].offset = 0;
		spd.partial[i].private = (unsigned long)ref;
		spd.nr_pages++;
		*ppos += size;
		}

		spd.nr_pages = i;