f2fs: add a tracepoint for f2fs_write_{meta,node,data}_page

This patch adds a tracepoint for f2fs_write_{meta,node,data}_page to trace when
page is writting out.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/checkpoint.c

@@ -157,6 +157,8 @@ static int f2fs_write_meta_page(struct page *page,
 	struct inode *inode = page->mapping->host;
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 
+	trace_f2fs_writepage(page, META);
+
 	if (unlikely(sbi->por_doing))
 		goto redirty_out;
 	if (wbc->for_reclaim)

fs/f2fs/data.c

@@ -788,6 +788,8 @@ static int f2fs_write_data_page(struct page *page,
 		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
 	};
 
+	trace_f2fs_writepage(page, DATA);
+
 	if (page->index < end_index)
 		goto write;
 

fs/f2fs/node.c

@@ -1199,6 +1199,8 @@ static int f2fs_write_node_page(struct page *page,
 		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
 	};
 
+	trace_f2fs_writepage(page, NODE);
+
 	if (unlikely(sbi->por_doing))
 		goto redirty_out;
 

include/trace/events/f2fs.h

@@ -751,6 +751,13 @@ DECLARE_EVENT_CLASS(f2fs__page,
 		__entry->dirty)
 );
 
+DEFINE_EVENT(f2fs__page, f2fs_writepage,
+
+	TP_PROTO(struct page *page, int type),
+
+	TP_ARGS(page, type)
+);
+
 DEFINE_EVENT(f2fs__page, f2fs_set_page_dirty,
 
 	TP_PROTO(struct page *page, int type),