Refactoring overlay and snapshot scanning code.

Both overlays and snapshots are now scanned at the same time, and each
device is only mounted once. Passphrases for LUKS volumes are only
asked for once, and unused ones are closed. Also, snapshot files on
encrypted partitions are now supported.

1 files changed, 33 insertions, 45 deletions

diff --git a/scripts/live b/scripts/live
index c3732fe..e0663b6 100755
--- a/scripts/live
+++ b/scripts/live
@@ -1059,26 +1059,6 @@ do_snap_copy ()
 	fi
 }
 
-find_snap ()
-{
-	# Look for ${snap_label}.* in block devices
-	snap_label="${1}"
-	black_listed_devices="${2}"
-	white_listed_devices="${3}"
-
-	if echo ${PERSISTENT_STORAGE} | grep -qw file
-	then
-		# search for image files
-		snapdata=$(find_files "${PERSISTENT_PATH}${snap_label}.squashfs ${PERSISTENT_PATH}${snap_label}.cpio.gz ${PERSISTENT_PATH}${snap_label}.ext2 ${PERSISTENT_PATH}${snap_label}.ext3 ${PERSISTENT_PATH}${snap_label}.ext4 ${PERSISTENT_PATH}${snap_label}.jffs2" "${black_listed_devices}" "${white_listed_devices}")
-	fi
-
-	if echo ${PERSISTENT_STORAGE} | grep -qw filesystem && [ -z "${snapdata}" ]
-	then
-		snapdata=$(find_cow_device "${snap_label}" "${black_listed_devices}" "${white_listed_devices}")
-	fi
-	echo "${snapdata}"
-}
-
 try_snap ()
 {
 	# copy the contents of previously found snapshot to ${snap_mount}
@@ -1397,34 +1377,43 @@ setup_unionfs ()
 
 		if echo ${PERSISTENT_METHOD} | grep -qw overlay
 		then
-			# search for label and files (this could be hugely optimized)
-			cowprobe=$(find_cow_device "${root_persistence}" "${blacklistdev}" "${whitelistdev}")
-			if [ -b "${cowprobe}" ]
-			then
-				# Blacklist /cow device, to avoid inconsistent setups for overlapping snapshots
-				# makes sense to have both persistence for /cow and /home mounted, maybe also with
-				# snapshots to be sure to really store some e.g key config files,
-				# but not on the same media
-				blacklistdev="${cowprobe}"
-				PERSISTENCE_IS_ON="1"
-				export PERSISTENCE_IS_ON
-			fi
-			# homecow just mount something on /home, this should be generalized some way
-			homecow=$(find_cow_device "${home_persistence}" "${blacklistdev}" "${whitelistdev}")
-			if [ -b "${homecow}" ]
-			then
-				PERSISTENCE_IS_ON="1"
-				export PERSISTENCE_IS_ON
-			fi
+			overlays="${root_persistence} ${home_persistence}"
 		fi
 
 		if echo ${PERSISTENT_METHOD} | grep -qw snapshot
 		then
-			root_snapdata=$(find_snap "${root_snapshot_label}" "${blacklistdev}" "${whitelistdev}")
-			# This second type should be removed when snapshot will get smarter,
-			# hence when "/etc/live-snapshot*list" will be supported also by
-			# ext2|ext3|ext4|jffs2 snapshot types.
-			home_snapdata=$(find_snap "${home_snapshot_label}" "${blacklistdev}" "${whitelistdev}")
+			snapshots="${root_snapshot_label} ${home_snapshot_label}"
+		fi
+
+
+		for media in $(find_persistent_media "${overlays}" "${snapshots}" "${blacklistdev}" "${whitelistdev}")
+		do
+			media="$(echo ${media} | tr ":" " ")"
+			case ${media} in
+				${root_persistence}=*)
+					cowprobe="${media#*=}"
+					;;
+				${home_persistence}=*)
+					homecow="${media#*=}"
+					;;
+				${root_snapshot_label}=*)
+					root_snapdata="${media#*=}"
+					;;
+				${home_snapshot_label}=*)
+					# This second type should be removed when snapshot will get smarter,
+					# hence when "/etc/live-snapshot*list" will be supported also by
+					# ext2|ext3|ext4|jffs2 snapshot types.
+					home_snapdata="${media#*=}"
+					;;
+				*)
+					;;
+			 esac
+		done
+
+		if [ -b "${cowprobe}" ] || [ -b "${homecow}" ]
+		then
+			PERSISTENCE_IS_ON="1"
+			export PERSISTENCE_IS_ON
 		fi
 
 		if [ -b "${cowprobe}" ]
@@ -1438,7 +1427,6 @@ setup_unionfs ()
 				fsck -y ${cowdevice}
 			fi
 		else
-			log_warning_msg "Unable to find the persistent medium"
 			cowdevice="tmpfs"
 			cow_fstype="tmpfs"
 			cow_mountopt="rw,noatime,mode=755"