f2fs: submit bio for node blocks in the reclaim path

If a node page is request to be written during the reclaiming path, we should
submit the bio to avoid pending to recliam it.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 478ce1e..dbf49cc 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1326,6 +1326,10 @@
 	dec_page_count(sbi, F2FS_DIRTY_NODES);
 	up_read(&sbi->node_write);
 	unlock_page(page);
+
+	if (wbc->for_reclaim)
+		f2fs_submit_merged_bio(sbi, NODE, WRITE);
+
 	return 0;
 
 redirty_out: