From 2e09ee3e58cd15af47149e7c9d86baa9890526b0 Mon Sep 17 00:00:00 2001
From: Michal Suchanek <hramrach@centrum.cz>
Date: Wed, 29 Sep 2010 10:37:15 +0200
Subject: [PATCH] Adding initial support for unionmount.

---
 hooks/live   |  7 +++++++
 scripts/live | 21 ++++++++++++++++++---
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/hooks/live b/hooks/live
index 3174d17..b5d43f2 100755
--- a/hooks/live
+++ b/hooks/live
@@ -251,3 +251,10 @@ then
 	#mkdir -p $DESTDIR/etc
 	#cp -p /etc/nsswitch.conf $DESTDIR/etc
 fi
+
+if [ "${LIVE_UNIONMOUNT}" = "true" ]
+then
+	# UnionMount
+	# only mount from patched util-linux can do this currently
+	copy_exec /bin/mount /bin/mount_full
+fi
diff --git a/scripts/live b/scripts/live
index f257218..4b1b92d 100755
--- a/scripts/live
+++ b/scripts/live
@@ -1206,9 +1206,16 @@ setup_unionfs ()
 					log_warning_msg "Unknown file system type on ${backdev} (${image}), assuming ${fstype}."
 				fi
 
-				mkdir -p "${croot}/${imagename}"
-				log_begin_msg "Mounting \"${image}\" on \"${croot}${imagename}\" via \"${backdev}\""
-				mount -t "${fstype}" -o ro,noatime "${backdev}" "${croot}/${imagename}" || panic "Can not mount ${backdev} (${image}) on ${croot}/${imagename}" && rofsstring="${croot}/${imagename}=${roopt}:${rofsstring}" && rofslist="${croot}/${imagename} ${rofslist}"
+				if [ "${UNIONTYPE}" != "unionmount" ]
+				then
+					mpoint="${croot}/${imagename}"
+					rofsstring="${mpoint}=${roopt}:${rofsstring}" && rofslist="${mpoint} ${rofslist}"
+				else
+					mpoint="${rootmnt}"
+				fi
+				mkdir -p "${mpoint}"
+				log_begin_msg "Mounting \"${image}\" on \"${mpoint}\" via \"${backdev}\""
+				mount -t "${fstype}" -o ro,noatime "${backdev}" "${mpoint}" || panic "Can not mount ${backdev} (${image}) on ${mpoint}"
 				log_end_msg
 			fi
 		done
@@ -1322,6 +1329,9 @@ setup_unionfs ()
 		cow_mountopt="rw,noatime,mode=755"
 	fi
 
+	if [ "${UNIONTYPE}" != "unionmount" ]
+	then
+
 	if [ "${cow_fstype}" = "nfs" ]
 	then
 		log_begin_msg \
@@ -1332,6 +1342,7 @@ setup_unionfs ()
 		mount -t ${cow_fstype} -o ${cow_mountopt} ${cowdevice} /cow || \
 			panic "Can not mount ${cowdevice} (o: ${cow_fstype}) on /cow"
 	fi
+	fi
 
 	rofscount=$(echo ${rofslist} |wc -w)
 
@@ -1376,6 +1387,10 @@ setup_unionfs ()
 				pidof unionfs-fuse >> /dev/.initramfs/varrun/sendsigs.omit || true
 				;;
 
+			unionmount)
+				mount_full -t ${cow_fstype} -o noatime,union,${cow_mountopt} ${cowdevice} "${rootmnt}" || panic "${UNIONTYPE} ${cowdevice} on ${rootmnt} failed with option noatime,union,${cow_mountopt}"
+				;;
+
 			*)
 				mount -t ${UNIONTYPE} -o noatime,${noxino_opt}dirs=/cow=rw:${rofsstring} ${UNIONTYPE} "${rootmnt}" || panic "mount ${UNIONTYPE} on ${rootmnt} failed with option noatime,${noxino_opt}dirs=/cow=rw:${rofsstring}"
 				;;
-- 
2.1.4