What is the size in pixels of the finished image you are refering to?
What is the size of the Gallery Wrap you want created?
As Digital Dog has pointed out, the import factor here is pixels, not DPI. However, you can use the desired DPI for the finished print as for calculating how many pixels you will need. If you will be printing 24 inches on the long side, at 300 DPI, your image should be at least 7,200 pixels in the long side. If your original does not meet that pixel requirement, you can use the Enhance -> Super Resolution feature to double the linear dimensions of the image in pixels.
One other factor is that canvas wrap prints, since they are on rough surface materials, do not really need 300 ppi/dpi. 200 dpi may actually be adequate.