Splitting out a first bunch of functions out to /live/live/boot/.

1 files changed, 171 insertions, 0 deletions

diff --git a/scripts/boot/snapshot.sh b/scripts/boot/snapshot.sh
new file mode 100755
index 0000000..3c9ebcd
--- /dev/null
+++ b/scripts/boot/snapshot.sh
@@ -0,0 +1,171 @@
+#!/bin/sh
+
+do_snap_copy ()
+{
+	fromdev="${1}"
+	todir="${2}"
+	snap_type="${3}"
+	size=$(fs_size "${fromdev}" "" "used")
+
+	if [ -b "${fromdev}" ]
+	then
+		log_success_msg "Copying snapshot ${fromdev} to ${todir}..."
+
+		# look for free mem
+		if [ -n "${HOMEMOUNTED}" -a "${snap_type}" = "HOME" ]
+		then
+			todev=$(awk -v pat="$(base_path ${todir})" '$2 == pat { print $1 }' /proc/mounts)
+			freespace=$(df -k | awk '/'${todev}'/{print $4}')
+		else
+			freespace=$(awk '/^MemFree:/{f=$2} /^Cached:/{c=$2} END{print f+c}' /proc/meminfo)
+		fi
+
+		tomount="/mnt/tmpsnap"
+
+		if [ ! -d "${tomount}" ]
+		then
+			mkdir -p "${tomount}"
+		fi
+
+		fstype=$(get_fstype "${fromdev}")
+
+		if [ -n "${fstype}" ]
+		then
+			# Copying stuff...
+			mount -o ro -t "${fstype}" "${fromdev}" "${tomount}" || log_warning_msg "Error in mount -t ${fstype} -o ro ${fromdev} ${tomount}"
+			cp -a "${tomount}"/* ${todir}
+			umount "${tomount}"
+		else
+			log_warning_msg "Unrecognized fstype: ${fstype} on ${fromdev}:${snap_type}"
+		fi
+
+		rmdir "${tomount}"
+
+		if echo ${fromdev} | grep -qs loop
+		then
+			losetup -d "${fromdev}"
+		fi
+
+		return 0
+	else
+		log_warning_msg "Unable to find the snapshot ${snap_type} medium"
+		return 1
+	fi
+}
+
+try_snap ()
+{
+	# copy the contents of previously found snapshot to ${snap_mount}
+	# and remember the device and filename for resync on exit in live-boot.init
+
+	snapdata="${1}"
+	snap_mount="${2}"
+	snap_type="${3}"
+	snap_relpath="${4}"
+
+	if [ -z "${snap_relpath}" ]
+	then
+		# root snapshot, default usage
+		snap_relpath="/"
+	else
+		# relative snapshot (actually used just for "/home" snapshots)
+		snap_mount="${2}${snap_relpath}"
+	fi
+
+	if [ -n "${snapdata}" ] && [ ! -b "${snapdata}" ]
+	then
+		log_success_msg "found snapshot: ${snapdata}"
+		snapdev="$(echo ${snapdata} | cut -f1 -d ' ')"
+		snapback="$(echo ${snapdata} | cut -f2 -d ' ')"
+		snapfile="$(echo ${snapdata} | cut -f3 -d ' ')"
+
+		if ! try_mount "${snapdev}" "${snapback}" "ro"
+		then
+			break
+		fi
+
+		RES="0"
+
+		if echo "${snapfile}" | grep -qs '\(squashfs\|ext2\|ext3\|ext4\|jffs2\)'
+		then
+			# squashfs, jffs2 or ext2/ext3/ext4 snapshot
+			dev=$(get_backing_device "${snapback}/${snapfile}")
+
+			do_snap_copy "${dev}" "${snap_mount}" "${snap_type}"
+			RES="$?"
+		else
+			# cpio.gz snapshot
+
+			# Unfortunately klibc's cpio is incompatible with the
+			# rest of the world; everything else requires -u -d,
+			# while klibc doesn't implement them. Try to detect
+			# whether it's in use.
+			cpiopath="$(which cpio)" || true
+			if [ "$cpiopath" ] && grep -aq /lib/klibc "$cpiopath"
+			then
+				cpioargs=
+			else
+				cpioargs='--unconditional --make-directories'
+			fi
+
+			if [ -s "${snapback}/${snapfile}" ]
+			then
+				BEFOREDIR="$(pwd)"
+				cd "${snap_mount}" && zcat "${snapback}/${snapfile}" | $cpiopath $cpioargs --extract --preserve-modification-time --no-absolute-filenames --sparse 2>/dev/null
+				RES="$?"
+				cd "${BEFOREDIR}"
+			else
+				log_warning_msg "${snapback}/${snapfile} is empty, adding it for sync on reboot."
+				RES="0"
+			fi
+
+			if [ "${RES}" != "0" ]
+			then
+				log_warning_msg "failure to \"zcat ${snapback}/${snapfile} | $cpiopath $cpioargs --extract --preserve-modification-time --no-absolute-filenames --sparse\""
+			fi
+		fi
+
+		umount "${snapback}" ||  log_warning_msg "failure to \"umount ${snapback}\""
+
+		if [ "${RES}" != "0" ]
+		then
+			log_warning_msg "Impossible to include the ${snapfile} Snapshot file"
+		fi
+
+	elif [ -b "${snapdata}" ]
+	then
+		# Try to find if it could be a snapshot partition
+		dev="${snapdata}"
+		log_success_msg "found snapshot ${snap_type} device on ${dev}"
+		if echo "${dev}" | grep -qs loop
+		then
+			# strange things happens, user confused?
+			snaploop=$( losetup ${dev} | awk '{print $3}' | tr -d '()' )
+			snapfile=$(basename ${snaploop})
+			snapdev=$(awk -v pat="$( dirname ${snaploop})" '$2 == pat { print $1 }' /proc/mounts)
+		else
+			snapdev="${dev}"
+		fi
+
+		if ! do_snap_copy "${dev}" "${snap_mount}" "${snap_type}"
+		then
+			log_warning_msg "Impossible to include the ${snap_type} Snapshot (i)"
+			return 1
+		else
+			if [ -n "${snapfile}" ]
+			then
+				# it was a loop device, user confused
+				umount ${snapdev}
+			fi
+		fi
+	else
+		log_warning_msg "Impossible to include the ${snap_type} Snapshot (o)"
+		return 1
+	fi
+
+	if [ -z ${PERSISTENCE_READONLY} ]
+	then
+		echo "export ${snap_type}SNAP=${snap_relpath}:${snapdev}:${snapfile}" >> snapshot.conf # for resync on reboot/halt
+	fi
+	return 0
+}