Again? Maybe the first time I’ve mentioned transactions here. This is a transcript of a nice talk on the implementation of the ext3 file system. Link.
(I did a bunch of work on the Newton’s transactional object store, and this takes me way back. We did a lot of the same tricks. I especially like the compatibility with the ext2 file system, once the ext3 fs has been recovered after a crash, that’s really cute).
There’s a bunch of stuff on the implementation of the BeOS file system in the book Practical File System Design with the Be File System by Dominic Giampaolo. It’s a nice book if you’re into file systems, transactions and meta-data.