diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index f6c2155e00267724c94513af7972b2322bad9741..1a7c42c64ff47ee7e55c378d0e067892d789e2d7 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -242,6 +242,7 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi,
 /**
  * bdi_start_writeback - start writeback
  * @bdi: the backing device to write from
+ * @sb: write inodes from this super_block
  * @nr_pages: the number of pages to write
  *
  * Description: