Add back (modified) unionfs code in linuxrc

ChangeLog

@@ -2,6 +2,10 @@
 # Copyright 1999-2008 Gentoo Foundation; 2008 Chris Gianelloni, Andrew Gaffney
 # Distributed under the GPL v2
 
+  12 Nov 2008; Andrew Gaffney <agaffney@gentoo.org> defaults/initrd.scripts,
+  defaults/linuxrc:
+  Add back (modified) unionfs code in linuxrc
+
   12 Nov 2008; Andrew Gaffney <agaffney@gentoo.org> gen_initramfs.sh:
   Add append_fuse() and append_unionfs_fuse() functions
 

defaults/initrd.scripts

@@ -961,3 +961,62 @@ find_looptype() {
 getdvhoff() {
 	echo $(( $(hexdump -n 4 -s $((316 + 12 * $2)) -e '"%i"' $1) * 512))
 }
+
+setup_unionfs() {
+	local rw_dir=$1
+	local ro_dir=$2
+	if [ "${USE_UNIONFS_NORMAL}" = '1' ]
+	then
+		# Directory used for rw changes in union mount filesystem
+		UNION=/union
+		MEMORY=/memory
+		if [ -z "$UID" ]
+		then
+			CHANGES=$MEMORY/unionfs_changes/default
+		else
+			CHANGES=$MEMORY/unionfs_changes/$UID
+		fi
+
+		mkdir -p ${MEMORY}
+		mkdir -p ${UNION}
+		good_msg "Loading fuse module"
+		modprobe fuse > /dev/null 2>&1
+#                 if [ -n "${UNIONFS}" ] 	 
+#                 then 	 
+#                         CHANGESDEV=${UNIONFS} 	 
+#                         good_msg "mounting $CHANGESDEV to $MEMORY for unionfs support" 	 
+#                         mount -t auto $CHANGESDEV $MEMORY 	 
+#                         # mount tmpfs only in the case when changes= boot parameter was 	 
+#                         # empty or we were not able to mount the storage device 	 
+#                         ret=$? 	 
+#                         if [ "${ret}" -ne 0 ] 	 
+#                         then 	 
+#                                 bad_msg "mount of $CHANGESDEV failed falling back to ramdisk based unionfs" 	 
+#                                 mount -t tmpfs tmpfs $MEMORY 	 
+#                         fi 	 
+#                         if [ "${CDROOT}" -eq '1' -a ! -f ${MEMORY}/livecd.unionfs  ] 	 
+#                         then 	 
+#                                 umount $MEMORY 	 
+#                                 bad_msg "failed to find livecd.unionfs file on $CHANGESDEV" 	 
+#                                 bad_msg "create a livecd.unionfs file on this device if you wish to use it for unionfs" 	 
+#                                 bad_msg "falling back to ramdisk based unionfs for safety" 	 
+#                                 mount -t tmpfs tmpfs $MEMORY 	 
+#                         fi 	 
+#                 else 	 
+                         good_msg "Mounting ramdisk to $MEMORY for unionfs support..." 	 
+                         mount -t tmpfs tmpfs $MEMORY 	 
+#                 fi 	 
+  	 
+		mkdir -p $CHANGES
+#		mount -t unionfs -o dirs=$CHANGES=rw unionfs ${UNION}
+		unionfs -o allow_others,allow_root,cow,noinitgroups ${rw_dir}=RW:${ro_dir} ${UNION}
+		ret=$?
+		if [ "${ret}" -ne 0 ]
+		then
+			bad_msg "Can't setup union ${UNION} in directory!"
+			USE_UNIONFS_NORMAL=0
+		fi
+	else
+		USE_UNIONFS_NORMAL=0
+	fi
+}

defaults/linuxrc

@@ -183,6 +183,33 @@ do
 		keymap\=*)
 			keymap=`parse_opt "${x}"`
 		;;
+		unionfs)
+			if [ ! -x /sbin/unionfs ]
+			then
+				USE_UNIONFS_NORMAL=0
+				bad_msg 'Unionctl not found: aborting use of unionfs!'
+			else
+				USE_UNIONFS_NORMAL=1
+			fi
+			;;
+#                 unionfs\=*) 	 
+#                         if [ ! -x /sbin/unionctl ] 	 
+#                         then 	 
+#                                 USE_UNIONFS_NORMAL=0 	 
+#                                 bad_msg 'Unionctl not found: aborting use of unionfs!' 	 
+#                         else 	 
+#                                 USE_UNIONFS_NORMAL=1 	 
+#                                 CMD_UNIONFS=`parse_opt "${x}"` 	 
+#                                 echo ${CMD_UNIONFS}|grep , >/dev/null 2>&1 	 
+#                                 if [ "$?" -eq '0' ] 	 
+#                                 then 	 
+#                                         UID=`echo ${CMD_UNIONFS#*,}` 	 
+#                                         UNIONFS=`echo ${CMD_UNIONFS%,*}` 	 
+#                                 else 	 
+#                                         UNIONFS=${CMD_UNIONFS} 	 
+#                                 fi 	 
+#                         fi 	 
+#                 ;;
 	esac
 done
 
@@ -512,23 +539,31 @@ then
 		fi
 	fi
 
+
+
 	# Unpacking additional packages from NFS mount
 	# This is useful for adding kernel modules to /lib
 	# We do this now, so that additional packages can add whereever they want.
 	if [ "${REAL_ROOT}" = '/dev/nfs' ]
 	then
-		if [ -e "${CHROOT}/mnt/cdrom/add" ]
+		if [ -e "${NEW_ROOT}/mnt/cdrom/add" ]
 		then
-				for targz in `ls ${CHROOT}/mnt/cdrom/add/*.tar.gz`
+				for targz in `ls ${NEW_ROOT}/mnt/cdrom/add/*.tar.gz`
 				do	
 					tarname=`basename ${targz}`
 					good_msg "Adding additional package ${tarname}"
-					(cd ${CHROOT} ; /bin/tar -xzf ${targz})
+					(cd ${NEW_ROOT} ; /bin/tar -xzf ${targz})
 				done
 		fi
 	fi
 
 
+	if [ "${USE_UNIONFS_NORMAL}" = '1' ]
+	then
+		setup_unionfs ${NEW_ROOT} ${NEW_ROOT}/${FS_LOCATION}
+		CHROOT=/union
+	else
+	
 	good_msg "Copying read-write image contents to tmpfs"
 	# Copy over stuff that should be writable
 	(cd "${NEW_ROOT}/${FS_LOCATION}"; cp -a ${ROOT_TREES} "${NEW_ROOT}")
@@ -579,6 +614,8 @@ then
 	mkdir initramfs proc tmp sys 2>/dev/null
 	chmod 1777 tmp
 
+	fi
+
 	#UML=`cat /proc/cpuinfo|grep UML|sed -e 's|model name.*: ||'`
 	#if [ "${UML}" = 'UML' ]
 	#then
@@ -594,6 +631,14 @@ then
 	then
 		sleep 10
 	fi
+else
+	if [ "${USE_UNIONFS_NORMAL}" = '1' ]
+	then
+		mkdir /union_changes
+		mount -t tmpfs tmpfs /union_changes
+		setup_unionfs /union_changes ${NEW_ROOT}
+		mkdir -p ${UNION}/tmp/.initrd
+	fi
 fi
 
 # Execute script on the cdrom just before boot to update things if necessary