diff --git a/fs/sync.c b/fs/sync.c
index 7cd005ea76390f385dc85af2c11e8121b6b4dd69..228e17b5e9ee911c2c2f58b4090e33b96954ff23 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -64,7 +64,7 @@ int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
 	/* sync the superblock to buffers */
 	sb = inode->i_sb;
 	lock_super(sb);
-	if (sb->s_op->write_super)
+	if (sb->s_dirt && sb->s_op->write_super)
 		sb->s_op->write_super(sb);
 	unlock_super(sb);