The snippet is from Bach's Tocatta & Fugue, I've also had trouble with some similar parts in other songs.
I wrote in an arrow and the 2,5 1,4 fingering for the top hand, which is what I use to play it (2,5 1,4 2,5 1,4 etc). I'm hoping some of the fine pianists here can shed some light on how I might come about tackling this part. It's 4 runs made up of several 2-note chords, the first run plays smoothly, second one feels slightly tougher, third one I can't tackle at all, and the fourth is also challenging for me. I'm assuming the runs are meant to be played legato. I can play them through slowly with some trouble, I absolutely can't play through all 4 at tempo.