diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index f068270..92579cc 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -298,7 +298,7 @@
 		memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
 		nilfs->ns_sbwtime[1] = t;
 	}
-	sbi->s_super->s_dirt = 0;
+	clear_nilfs_sb_dirty(nilfs);
 	return nilfs_sync_super(sbi, dupsb);
 }
 
@@ -342,7 +342,7 @@
 		err = nilfs_construct_segment(sb);
 
 	down_write(&nilfs->ns_sem);
-	if (sb->s_dirt)
+	if (nilfs_sb_dirty(nilfs))
 		nilfs_commit_super(sbi, 1);
 	up_write(&nilfs->ns_sem);