Q: Camera roll not seen in album after updating ios8

That is intentional. The Camera Roll album is no longer show as a separate album, also My Photo Stream is no longer a separate album.  This Help document explains, where you will see the photos now.

  Get help finding your Photos in iOS 8http://support.apple.com/kb/HT6464

Have you enabled the "Summarise Photos" option? Then disable it.

By default, Photos displays a representative subset of your photos when you view by year or by collection.

To see all your photos, go to Settings > Photos & Camera, then turn off Summarize Photos.

And did you migrate your photos from iPhoto?  Some photos may still be in the iPhoto Library, that is no longer supported:

See: Migrating from iPhoto for iOS to Photos on iOS 8