f2fs: add tracepoint for vm_page_mkwrite

This patch adds a tracepoint for f2fs_vm_page_mkwrite.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index c80faa2..2d4190a 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -88,6 +88,7 @@
 	set_page_dirty(page);
 	SetPageUptodate(page);
 
+	trace_f2fs_vm_page_mkwrite(page, DATA);
 mapped:
 	/* fill the page */
 	wait_on_page_writeback(page);
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index ebde3af..e0dc355 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -667,6 +667,13 @@
 	TP_ARGS(page, type)
 );
 
+DEFINE_EVENT(f2fs__page, f2fs_vm_page_mkwrite,
+
+	TP_PROTO(struct page *page, int type),
+
+	TP_ARGS(page, type)
+);
+
 TRACE_EVENT(f2fs_submit_write_page,
 
 	TP_PROTO(struct page *page, block_t blk_addr, int type),