ring-buffer: reset write field for ring_buffer_read_page

Impact: fix ring_buffer_read_page

After a page is swapped into the ring buffer, the write field must
also be reset.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index a8c275c01e83c7514b0c890248e1f80f8436570a..9baad7ee4b367b74f08d1b0ac61720ca646c5ffc 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2492,6 +2492,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
                rb_init_page(bpage);
                bpage = cpu_buffer->reader_page->page;
                cpu_buffer->reader_page->page = *data_page;
+               local_set(&cpu_buffer->reader_page->write, 0);
                cpu_buffer->reader_page->read = 0;
                *data_page = bpage;
        }