[ridiculous_fish]

A very accessible (though dated) intro to filesystems is Practical File System Design, by Dominic Giampaolo.

PDF link: http://www.nobius.org/practical-file-system-design.pdf

[Q6T46nT668w6i3m]

Frankly, not too much has changed since Giampaolo. In fact, it is still standard reading in many graduate seminars on the subject!

[vondur]

Is he the guy who did the BeOS filesystem?

[peterkelly]

Yes. Later went to Apple and did Spotlight.

https://en.wikipedia.org/wiki/Dominic_Giampaolo

[saagarjha]

And APFS: https://developer.apple.com/videos/play/wwdc2016/701/