Solving the ext3 latency problem

Also, in practice (and as evidenced by my testing), data=guarded will leave you with smaller file sizes (potentially 0-length) when you crash. But that is better than having garbage (potentially other people's data) in those files.

The rename & truncate hacks will help flush some data, but if you, say, untar a kernel tree and crash, those hacks don't come into play.

data=writeback would wind up garbage in the files, data=guarded would wind up with 0-length or shortened files with no garbage, and data=ordered would likely have more files intact due to the journal transaction commits causing more flushing along the way... and no garbage.