f2fs: add to account meta IO

This patch supports to account meta IO, it enables to show write IO
from f2fs more comprehensively via 'status' debugfs entry.

Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index d33e9d0..3fa8870 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3018,6 +3018,7 @@ void f2fs_do_write_meta_page(struct f2fs_sb_info *sbi, struct page *page,
 	ClearPageError(page);
 	f2fs_submit_page_write(&fio);
 
+	stat_inc_meta_count(sbi, page->index);
 	f2fs_update_iostat(sbi, io_type, F2FS_BLKSIZE);
 }