# Copyright 1999-2007 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $

inherit eutils linux-mod

DESCRIPTION="Another Unionfs. The Unionfs is originally developed by Erez Zadok and his team. Once aufs was entirely re-designed and re-implemented Unionfs. Enhancing with many original ideas, it becomes totally different software while keeping the basic features."
HOMEPAGE="http://aufs.sourceforge.net"
SRC_URI="www.fh-kl.de/~torsten.kockler/gentoo/${P}.tar.bz2"
LICENSE="GPL-2"
KEYWORDS="~x86"
IUSE="ksize nfs"
SLOT="0"

kernel_version_info() {
	eerror
	eerror "Aufs is being developed and tested on linux-2.6.16 and later."
	eerror "Make sure you have a proper kernel version!"
	eerror
}

kernel_ksize_patched() {
	if grep -qs "EXPORT_SYMBOL(ksize);" "${KERNEL_DIR}/mm/slab.c"
		then
		einfo "Your kernel has already been patched for ksize"
		return 0
	fi
	return 1
}

ksize_patch() {
	cd ${KV_DIR}
	epatch ${S}/ksize.patch
	ewarn
	ewarn
	ewarn "You have to recompile your kernel to make ksize work"
	ewarn
}

kernel_lhash_patched() {
	if grep -qs "EXPORT_SYMBOL(__lookup_hash);" "${KERNEL_DIR}/fs/namei.c" || grep -qs "struct dentry * __lookup_hash(struct qstr *name, struct dentry * base, struct nameidata *nd);" "${KERNEL_DIR}/fs/namei.h"
		then
		einfo "Your kernel has already been patched for lhash"
		return 0
	fi
	return 1
}

lhash_patch() {
	cd ${KV_DIR}
	epatch ${S}/lhash.patch
	ewarn
	ewarn
	ewarn "You have to recompile your kernel to make the lhash patch for nfs-support work"
	ewarn
}

pkg_setup(){
	# kernel version check
	if ! kernel_is gt 2 6 16
	then
		kernel_version_info
		die
	fi

	linux-mod_pkg_setup


}

src_unpack() {
	unpack ${A}
	cd ${S}
	emake \
	ARCH=i386 \
	KDIR=${ROOT}/lib/modules/${KV_FULL}/build \
	-f local.mk

}

src_install() {
	exeinto /sbin
	exeopts -m0500
	doexe mount.aufs umount.aufs auplink aulchown
	doman aufs.5
	MODULE_NAMES="aufs(addon/fs/${PN}:)"
	BUILD_TARGETS=" "
	linux-mod_src_install
}

pkg_postinst() {

	# ksize Patch
	if use ksize
	then
		kernel_ksize_patched || \
		ksize_patch
	fi

	#lhash Patch
	if use nfs && kernel_is ge 2 6 19
	then	
		kernel_lhash_patched || \
		lhash_patch
	fi

	einfo
	einfo "To be able to use aufs, you have to load the kernel module by typing:"
	einfo "modprobe aufs"
	einfo
	einfo "For further information refer to the aufs manpage"
	einfo
}