ext4 and data loss

I think ext4's tradeoff is a very sane one. I don't expect my machine to
crash all the time (in fact I can't remember when it last did, must have
been in something like 2005). If it gives a speedup measured in tens of
percents, it's the only sane thing to do.

And for the case when it's not sane, there's f(data)sync().