Press Command-J (PC: Control-J) to duplicate the Background layer. Then use the Image>Canvas Size command, or press Command-Option-C (PC: Control-Alt-C), to add 2 inches of canvas (with the Relative checkbox turned on) to both the width and height. Click on the Create a New Layer icon at the bottom of the Layers palette to add a blank layer above the photo layer. As an optional step, make sure the copied photo layer is active, press-and-hold the Command key (PC: Control key), and click on the Create a New Layer icon to add a layer below the copied photo layer that you can fill with whatever color you want to use as the background. Here I pressed D to set the Foreground and Background to the default colors and then pressed Command-Delete (PC: Control-Backspace) to fill the new layer with white.