As I am nowadays using the keyworded gentoo-sources, I am already using the 2.6.29 kernel with promised updated ext4 stuff and some more goodies. However, after doing my normal upgrading routine with make oldconfig and sifting through all the new options, running my 'build kernel and drivers'-script, my system wouldn't boot =|. Unable to remount read-write dmesg said. A wee bit stumped, I went back to 2.6.28 for a few days but now I had a go again and took a look at my fstab. In the mount options, I had put "extents, barriers=0".