# Copyright 1999-2009 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $

inherit eutils linux-mod

DESCRIPTION="An entirely re-designed and re-implemented Unionfs."
HOMEPAGE="http://aufs.sourceforge.net/"
SRC_URI="http://dev.gentooexperimental.org/~tommy/distfiles/${P}.tar.bz2"

LICENSE="GPL-2"
SLOT="0"
KEYWORDS="~amd64 ~x86"
IUSE="debug fuse hinotify nfs nfsexport robr sec_perm"

S="${WORKDIR}"/aufs

MODULE_NAMES="aufs(misc:${S})"

pkg_setup() {
	# kernel version check
	if kernel_is lt 2 6 16 ; then
		eerror "${PN} is being developed and tested on linux-2.6.16 and later."
		eerror "Make sure you have a proper kernel version!"
		die "Wrong kernel version"
	fi

	get_version

	# assume no kernel patches will be applied today
	APPLY_KERNEL_PATCH="n"

	# Check if sec_perm patch needs to be applied
	if kernel_is ge 2 6 24 && linux_chkconfig_present "SECURITY" ; then
		APPLY_SEC_PERM_PATCH="n"
		if ! grep -qs "EXPORT_SYMBOL(security_inode_permission);" "${KV_DIR}/security/security.c" ; then
			APPLY_SEC_PERM_PATCH="y"
			APPLY_KERNEL_PATCH="y"
		fi

		# make sure the user is allowing this to happen
		if [[ APPLY_SEC_PERM_PATCH = "y" ]] && ! use sec_perm; then
			eerror "${PN} requires that all kernels with CONFIG_SECURITY enabled >= 2.6.24"
			eerror "be patched.  Please enable USE=\"sec_perm\" to allow this patch to be"
			eerror "applied."
			die "Invalid configuration"
		fi
	# Also check to make sure they aren't enabling it when they don't need to
	else
		if use sec_perm ; then
			eerror "${PN} does not require the sec_perm patch to be applied to your kernel."
			eerror "Please disabe the sec_perm USE flag: USE=\"-sec_perm\"."
			die "Invalid configuration"
		fi
	fi

	# Check for applicability of lhash patch for NFS branch support
	if use nfs && kernel_is ge 2 6 19 ; then
		APPLY_LHASH_PATCH="n"
		# If lhash patch is not applied
		if ! grep -qs "EXPORT_SYMBOL(__lookup_hash);" "${KV_DIR}/fs/namei.c" \
		&& ! grep -qs "struct dentry * __lookup_hash(struct qstr *name, struct dentry * base, struct nameidata *nd);" "${KV_DIR}/fs/namei.h" ; then
			APPLY_LHASH_PATCH="y"
			APPLY_KERNEL_PATCH="y"
		fi
	fi

	# If a patch has to be applied
	if [[ ${APPLY_KERNEL_PATCH} == "y" ]] ; then
		ewarn "Patching your kernel..."
		cd ${KV_DIR}

		# If the sec_perm patch has to be applied
		if [[ ${APPLY_SEC_PERM_PATCH} == "y" ]] ; then
			epatch "${FILESDIR}"/${P}-sec_perm-2.6.24.patch
		fi

		# if the lhash patch has to be applied
		if [[ ${APPLY_LHASH_PATCH} == "y" ]] ; then
			if kernel_is ge 2 6 24 ; then
				epatch "${FILESDIR}"/${PN}-lhash-2.6.24.patch
			else
				if kernel_is ge 2 6 22 ; then
					epatch "${FILESDIR}"/${PN}-lhash-2.6.22.patch
				else
					epatch "${FILESDIR}"/${PN}-lhash-2.6.19.patch
				fi
			fi
		fi
	fi

	linux-mod_pkg_setup
}

src_unpack(){
	unpack ${A}
	cd "${S}"

	# Enable hinotify in priv_def.mk
	if use hinotify && kernel_is ge 2 6 18 ; then
		echo "CONFIG_AUFS_HINOTIFY = y" >> priv_def.mk || die "setting hinotify in priv_def.mk failed!"
	fi

	# Disable SYSAUFS for kernel less than 2.6.18
	if kernel_is lt 2 6 18 ; then
		echo "CONFIG_AUFS_SYSAUFS = " >> priv_def.mk || die "unsetting sysaufs in priv_def.mk failed!"
	fi

	# Enable lhash in priv_def.mk
	if use nfs && kernel_is ge 2 6 19 ; then
		echo "CONFIG_AUFS_LHASH_PATCH = y" >> priv_def.mk || die "setting lhash in priv_def.mk failed!"
	fi

	# Enable nfsexport in priv_def.mk
	if use nfsexport && kernel_is ge 2 6 18 ; then
		echo "CONFIG_AUFS_EXPORT = y" >> priv_def.mk || die "setting export in priv_def.mk failed!"
	fi

	# Enable aufs readonly-branch in priv_def.mk
	if use robr ; then
		echo "CONFIG_AUFS_ROBR = y" >> priv_def.mk || die "setting robr in priv_def.mk failed!"
	fi

	# Enable FUSE workaround for AUFS
	if use fuse ; then
		echo "CONFIG_AUFS_WORKAROUND_FUSE = y" >> priv_def.mk || die "setting workaround_fuse in priv_def.mk failed!"
	fi

	# Enable / Disable debugging
	if use debug ; then
		echo "CONFIG_AUFS_DEBUG = y" >> priv_def.mk || die "setting debug in priv_dev.mk failed!"
	else
		echo "CONFIG_AUFS_DEBUG = " >> priv_def.mk || die "setting debug in priv_dev.mk failed!"
	fi

	# Check if a vserver-kernel is installed
	if [[ -e ${KV_DIR}/include/linux/vserver ]] ; then
		einfo "vserver kernel seems to be installed"
		einfo "using vserver patch"
		echo "AUFS_DEF_CONFIG = -DVSERVER" >> priv_def.mk || die "setting vserver in priv_def.mk failed!"
	fi
}

src_compile() {
	use x86 && ARCH=i386
	use amd64 && ARCH=x86_64
	emake KDIR=${KV_DIR} SUBLEVEL=${KV_PATCH} -f local.mk || die "emake failed"
}

src_install() {
	cd util
	exeinto /sbin
	exeopts -m0500
	doexe mount.aufs umount.aufs auplink aulchown || die
	doman aufs.5 || die
	insinto /etc/default
	newins etc_default_aufs aufs || die
	linux-mod_src_install
}

pkg_postinst() {
	elog "To be able to use aufs, you have to load the kernel module by typing:"
	elog "modprobe aufs"
	elog "For further information refer to the aufs man page"

	if use sec_perm || use nfs; then
		ewarn "Your kernel has been patched in order to export security"
		ewarn "permissions.  You will need to recompile your kernel with"
		ewarn "this new patch in order for ${PN} to function."
	fi

	linux-mod_pkg_postinst
}