Where to read about softupdates journaling?

Question

FreeBSD

From the release notices for Freebsd 9.0:
The FreeBSD Fast File System now supports softupdates journaling. It introduces a intent log into a softupdates-enabled file system which eliminates the need for background fsck(8) even on unclean shutdown. This can be enabled in a per-filesystem basis by using the -j flag of the newfs(8) utility or the -j enable option of the tunefs(8) utility. Note that the 9.0-RELEASE installer automatically enables softupdates journaling for newly-created UFS file systems.[r207141, r218726]

Where can I read about this? I can't find it anywhere.
Well, or respected dons, perhaps they will tell you if there are any side effects with tunefs -j enable for the data file system? And what are the pros/cons/pitfalls? How much does performance drop when softupdates journaling is enabled? How is it better/worse than logging via geom?

Answer 1

I admire people who want to get to the bottom of the issue! Bravo!
man gjournal this, I'm sure you already read it,
then
www.usenix.org/legacy/event/usenix2000/general/full_papers/seltzer/seltzer_html/
forums.freebsd.org/showthread.php?t=39125
www.postgresql.org/message- id/48DA13EF.3060103 @shopzeus.com
www.mckusick.com/softdep/suj.pdf Good
luck!