e2fsck slows boot

@mschnell there is no guarantee that the last written sector before the power loss will actually be written, there is just a guarantee that the table is still recoverable in a stable state when the power is restored, either the state before the last write or the one after that. There are several ways of doing this, one that comes to mind is two keep two copies of the table in different pages and have a way to detect which one is valid at boot up.

@jpe1313 a journal recovery can cause a lot of read/write accesses, so using a faster mode would definitely make the mount time faster. We use the Evatronix Compact Flash controller which works well in all PIO and DMA modes. It's not free and I don't know if they have drivers for Linux, though. I don't think it's a cood idea to try to write on the filesystem before it is fully checked, you could overwrite important data and could make it unrecoverable. Did you have a look at other filesystems? Logfs seems to have fast mount times, but I don't know how easy it is to compile a kernel with it.