A Fast File System for Unix (1984)

Full pdf of the paper: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.114.9535&rep=rep1&type=pdf

This was a classic even 10 years ago, when I read it in my operating systems seminar in grad school. This is the paper that taught me how disk-based file systems are organized, and why.