Answer: A M
On github, I found a similar solution source code, so you can call the following method in Constructor:

private void endlessBackground() {
    // Create the two background sprites which will alternate
    _oddBackground = CCSprite.sprite("blue_background.png");
    _evenBackground = CCSprite.sprite("blue_background.png");
    // One starts dead centre and one starts exactly one screen height above
    oddBackground.setPosition(_winSize.width / 2, _winSize.height / 2);
    evenBackground.setPosition(_winSize.width / 2, _winSize.height
            + (_winSize.height / 2));
    // Schedule the scrolling action
    schedule("scroll");
    // Add sprites to the layer
    addChild(_oddBackground).addChild(_evenBackground);
}

public void scroll(float dt) {
    // move them 100*dt pixels down
    _oddBackground.setPosition(_oddBackground.getPosition().x,
            _oddBackground.getPosition().y - 150 * dt);
    _evenBackground.setPosition(_evenBackground.getPosition().x,
            _evenBackground.getPosition().y - 150 * dt);
    // reset position when they are off from view.
    if (_oddBackground.getPosition().y < -_winSize.height / 2) {
        _oddBackground.setPosition(_winSize.width / 2, _winSize.height / 2);
        _evenBackground.setPosition(_winSize.width / 2, _winSize.height
                + (_winSize.height / 2));
    }
}
}

Answer: M.Tahir Ashraf
You can try the following code:

CCTexture2D *texture = CCTextureCache::sharedTextureCache()->addImage("pic.png");
ccTexParams params = {GL_LINEAR, GL_LINEAR, GL_REPEAT, GL_REPEAT};
texture->setTexParameters(&params);

CCSprite *sprite = CCSprite::spriteWithTexture(texture, CCRectMake(0, 0, 90, 90));

At the same time, be sure to ensure that the height and width of the image are both powers of 2.

Answer: Oleg Vaskevich
It seems that CCRepeatForever action can only run goBack instructions, which means that the operation is irreversible, so you can try the following code:

CCIntervalAction go = CCMoveBy.action(4, CGPoint.ccp(winSize.width, 0));
CCIntervalAction goBack = go.reverse();
CCIntervalAction seq = CCSequence.actions(go, goBack);
CCRepeatForever action = CCRepeatForever.action(seq); // change to seq instead of goBack
parallaxNode.runAction(action);