Description:
I was about to report this already when this change was still in [linux]'s trunk but whatever.

This commit introduced with [linux] has rendered (g)parted unusable: http://projects.archlinux.org/svntogit/packages.git/commit/linux/trunk?id=fe6ea2ce1a67a3e4dc749d580939fd805b839921

Since gparted wants to get the kernel version as a 3-part scheme (as in 2.6.x times) linux 3.0's 2-part one requires patching:
gpartedbin: arch/linux.c:2834: linux_disk_commit: Assertion `_have_blkpg ()' failed.

So just apply this to [parted] and then rebuild [gparted] (I verified with the AUR package 'parted-git' that this is the one they use in Git): http://thread.gmane.org/gmane.comp.gnu.parted.devel/3529/focus=3539

Additional info:
* package version(s): linux 3.0-2, parted 3.0-2, gparted 0.9.0-2

Steps to reproduce:
1) Install [linux]
2) Install [gparted]
3) Boot (to the new kernel)
4) Try to open gparted

ps. I can't attach the patch because no matter in what form did I try to the apply it it just wouldn't work. I had to do it manually :p.