Among the unfortunate people, you are the lucky one-you had a harmonious relationship with your father before his death and were mentally healthy enough to accept the reality.
Father's smile may have many meanings, at least it is a blessing to you. This reflects that you have a good relationship with your father.
Black face may be related to the cause of death. But it also means that you know in your dream that he has passed away, which means that you have accepted the fact that he has passed away-a smile may be your father's affirmation of your strength.
bless