I have been looking around for documentation on how journalling is implemented in ext3 and couldn't find any good resources. I am familiar with the internals of ext2 and have gone through the implementation of the same in Linux and Minix.
Could you point me towards resources/code snippets which could help me in understanding the implementation of journalling in ext3?
This is not exactly how the journaling in Ext3 works actually, but a preliminary work I find interesting : http://original.jamesthornton.com/hotlist/linux-filesystems/ext3-journal-design.pdf
And this is one of the first presentation about Ext3 done by the author of the aforementioned paper : http://olstrans.sourceforge.net/release/OLS2000-ext3/OLS2000-ext3.html
There's been a lot of improvement over the year, but these two links will give you a good insight of what is at stake when designing an journaled filesystem.