Dropping snapshot functionality, superseeded by awesome custom mount persistence.

See the following threads for more information:

  * http://lists.debian.org/debian-live/2012/04/msg00110.html
  * http://lists.debian.org/debian-live/2012/06/msg00039.html

6 files changed, 15 insertions, 312 deletions

diff --git a/scripts/boot/cmdline.sh b/scripts/boot/cmdline.sh
index 296d1f7..669f5bc 100755
--- a/scripts/boot/cmdline.sh
+++ b/scripts/boot/cmdline.sh
@@ -210,9 +210,6 @@ Cmdline ()
 				old_root_overlay_label="${old_root_overlay_label}-${_PARAMETER#persistence-subtext=}"
 				old_home_overlay_label="${old_home_overlay_label}-${_PARAMETER#persistence-subtext=}"
 				custom_overlay_label="${custom_overlay_label}-${_PARAMETER#persistence-subtext=}"
-				root_snapshot_label="${root_snapshot_label}-${_PARAMETER#persistence-subtext=}"
-				old_root_snapshot_label="${root_snapshot_label}-${_PARAMETER#persistence-subtext=}"
-				home_snapshot_label="${home_snapshot_label}-${_PARAMETER#persistence-subtext=}"
 				;;
 
 			nopersistence)
@@ -337,7 +334,7 @@ Cmdline ()
 
 	if [ -z "${PERSISTENCE_METHOD}" ]
 	then
-		PERSISTENCE_METHOD="snapshot,overlay"
+		PERSISTENCE_METHOD="overlay"
 		export PERSISTENCE_METHOD
 	fi
 
diff --git a/scripts/boot/misc-helpers.sh b/scripts/boot/misc-helpers.sh
index 8970327..241bba1 100755
--- a/scripts/boot/misc-helpers.sh
+++ b/scripts/boot/misc-helpers.sh
@@ -842,8 +842,7 @@ is_gpt_device ()
 probe_for_gpt_name ()
 {
 	local overlays="${1}"
-	local snapshots="${2}"
-	local dev="${3}"
+	local dev="${2}"
 
 	local gpt_dev="${dev}"
 	if is_active_luks_mapping ${dev}
@@ -859,7 +858,7 @@ probe_for_gpt_name ()
 	fi
 
 	local gpt_name=$(get_gpt_name ${gpt_dev})
-	for label in ${overlays} ${snapshots}
+	for label in ${overlays}
 	do
 		if [ "${gpt_name}" = "${label}" ]
 		then
@@ -871,10 +870,9 @@ probe_for_gpt_name ()
 probe_for_fs_label ()
 {
 	local overlays="${1}"
-	local snapshots="${2}"
-	local dev="${3}"
+	local dev="${2}"
 
-	for label in ${overlays} ${snapshots}
+	for label in ${overlays}
 	do
 		if [ "$(/sbin/blkid -s LABEL -o value $dev 2>/dev/null)" = "${label}" ]
 		then
@@ -886,8 +884,7 @@ probe_for_fs_label ()
 probe_for_file_name ()
 {
 	local overlays="${1}"
-	local snapshots="${2}"
-	local dev="${3}"
+	local dev="${2}"
 
 	local ret=""
 	local backing="$(mount_persistence_media ${dev} probe)"
@@ -905,17 +902,6 @@ probe_for_file_name ()
 			ret="${ret} ${label}=${loopdev}"
 		fi
 	done
-	for label in ${snapshots}
-	do
-		for ext in squashfs cpio.gz ext2 ext3 ext4 jffs2
-		do
-			path="${PERSISTENCE_PATH}${label}.${ext}"
-			if [ -f "${backing}/${path}" ]
-			then
-				ret="${ret} ${label}=${dev}:${backing}:${path}"
-			fi
-		done
-	done
 
 	if [ -n "${ret}" ]
 	then
@@ -927,19 +913,15 @@ probe_for_file_name ()
 
 find_persistence_media ()
 {
-	# Scans devices for overlays and snapshots, and returns a whitespace
+	# Scans devices for overlays, and returns a whitespace
 	# separated list of how to use them. Only overlays with a partition
-	# label or file name in ${overlays} are returned, and ditto for
-	# snapshots with labels in ${snapshots}.
+	# label or file name in ${overlays} are returned.
 	#
 	# When scanning a LUKS device, the user will be asked to enter the
 	# passphrase; on failure to enter it, or if no persistence partitions
 	# or files were found, the LUKS device is closed.
 	#
-	# For a snapshot file the return value is ${label}=${snapdata}", where
-	# ${snapdata} is the parameter used for try_snap().
-	#
-	# For all other cases (overlay/snapshot partition and overlay file) the
+	# For all other cases (overlay partition and overlay file) the
 	# return value is "${label}=${device}", where ${device} a device that
 	# can mount the content. In the case of an overlay file, the device
 	# containing the file will remain mounted as a side-effect.
@@ -949,8 +931,7 @@ find_persistence_media ()
 	# scanned.
 
 	local overlays="${1}"
-	local snapshots="${2}"
-	local white_listed_devices="${3}"
+	local white_listed_devices="${2}"
 	local ret=""
 
 	local black_listed_devices="$(what_is_mounted_on /live/image)"
@@ -983,14 +964,14 @@ find_persistence_media ()
 		# Probe for matching GPT partition names or filesystem labels
 		if is_in_comma_sep_list filesystem ${PERSISTENCE_STORAGE}
 		then
-			result=$(probe_for_gpt_name "${overlays}" "${snapshots}" ${dev})
+			result=$(probe_for_gpt_name "${overlays}" ${dev})
 			if [ -n "${result}" ]
 			then
 				ret="${ret} ${result}"
 				continue
 			fi
 
-			result=$(probe_for_fs_label "${overlays}" "${snapshots}" ${dev})
+			result=$(probe_for_fs_label "${overlays}" ${dev})
 			if [ -n "${result}" ]
 			then
 				ret="${ret} ${result}"
@@ -1001,7 +982,7 @@ find_persistence_media ()
 		# Probe for files with matching name on mounted partition
 		if is_in_comma_sep_list file ${PERSISTENCE_STORAGE}
 		then
-			result=$(probe_for_file_name "${overlays}" "${snapshots}" ${dev})
+			result=$(probe_for_file_name "${overlays}" ${dev})
 			if [ -n "${result}" ]
 			then
 				ret="${ret} ${result}"
diff --git a/scripts/boot/mountroot.sh b/scripts/boot/mountroot.sh
index bad0a78..dbc66d4 100755
--- a/scripts/boot/mountroot.sh
+++ b/scripts/boot/mountroot.sh
@@ -184,18 +184,6 @@ mountroot ()
 		fi
 	fi
 
-	# copy snapshot configuration if exists
-	if [ -f snapshot.conf ]
-	then
-		log_begin_msg "Copying snapshot.conf to ${rootmnt}/etc/live/boot.d"
-		if [ ! -d "${rootmnt}/etc/live/boot.d" ]
-		then
-			mkdir -p "${rootmnt}/etc/live/boot.d"
-		fi
-		cp snapshot.conf "${rootmnt}/etc/live/boot.d/"
-		log_end_msg
-	fi
-
 	if [ -f /etc/resolv.conf ] && [ ! -s ${rootmnt}/etc/resolv.conf ]
 	then
 		log_begin_msg "Copying /etc/resolv.conf to ${rootmnt}/etc/resolv.conf"
@@ -208,7 +196,6 @@ mountroot ()
 		panic "A wrong rootfs was mounted."
 	fi
 
-	persistence_exclude
 	fstab
 	Netbase
 
diff --git a/scripts/boot/overlay.sh b/scripts/boot/overlay.sh
index 17a47e1..7b79df6 100755
--- a/scripts/boot/overlay.sh
+++ b/scripts/boot/overlay.sh
@@ -202,33 +202,11 @@ setup_unionfs ()
 			overlays="${old_root_overlay_label} ${old_home_overlay_label} ${custom_overlay_label}"
 		fi
 
-		if is_in_comma_sep_list snapshot ${PERSISTENCE_METHOD}
-		then
-			snapshots="${root_snapshot_label} ${home_snapshot_label}"
-		fi
-
-		local root_snapdata=""
-		local home_snapdata=""
 		local overlay_devices=""
-		for media in $(find_persistence_media "${overlays}" "${snapshots}" "${whitelistdev}")
+		for media in $(find_persistence_media "${overlays}" "${whitelistdev}")
 		do
 			media="$(echo ${media} | tr ":" " ")"
 			case ${media} in
-				${root_snapshot_label}=*|${old_root_snapshot_label}=*)
-					if [ -z "${root_snapdata}" ]
-					then
-						root_snapdata="${media#*=}"
-					fi
-					;;
-				${home_snapshot_label}=*)
-					# This second type should be removed when snapshot will get smarter,
-					# hence when "/etc/live-snapshot*list" will be supported also by
-					# ext2|ext3|ext4|jffs2 snapshot types.
-					if [ -z "${home_snapdata}" ]
-					then
-						home_snapdata="${media#*=}"
-					fi
-					;;
 				${old_root_overlay_label}=*)
 					device="${media#*=}"
 					fix_backwards_compatibility ${device} / union
@@ -409,17 +387,12 @@ setup_unionfs ()
 				close_persistence_media ${overlay}
 			fi
 		done
-
-		# Look for other snapshots to copy in
-		[ -n "${root_snapdata}" ] && try_snap "${root_snapdata}" "${rootmnt}" "ROOT"
-		# This second type should be removed when snapshot grow smarter
-		[ -n "${home_snapdata}" ] && try_snap "${home_snapdata}" "${rootmnt}" "HOME" "/home"
 	fi
 
 	mkdir -p "${rootmnt}/live"
 	mount -o move /live "${rootmnt}/live" >/dev/null 2>&1 || mount -o bind /live "${rootmnt}/live" || log_warning_msg "Unable to move or bind /live to ${rootmnt}/live"
 
-	# shows cow fs on /overlay for use by live-snapshot
+	# shows cow fs on /overlay (FIXME: do we still need/want this? probably yes)
 	mkdir -p "${rootmnt}/live/overlay"
 	mount -o move /live/overlay "${rootmnt}/live/overlay" >/dev/null 2>&1 || mount -o bind /overlay "${rootmnt}/live/overlay" || log_warning_msg "Unable to move or bind /overlay to ${rootmnt}/live/overlay"
 
diff --git a/scripts/boot/persistence-excludes.sh b/scripts/boot/persistence-excludes.sh
deleted file mode 100755
index ee9521e..0000000
--- a/scripts/boot/persistence-excludes.sh
+++ /dev/null
@@ -1,62 +0,0 @@
-#!/bin/sh
-
-#set -e
-
-persistence_exclude ()
-{
-	# Persistence enhancer script
-	# This script saves precious time on slow persistence devices/image files
-	# and writes on flash based device.
-	# a tmpfs on $PERSTMP is mounted and directories listed in
-	# /etc/live-persistence.binds will be copied there and then bind mounted back.
-
-	if [ -z "${PERSISTENCE}" ] || [ -n "${NOPERSISTENCE}" ] || [ -z "${PERSISTENCE_IS_ON}" ] || [ ! -f /root/etc/live-persistence.binds ]
-	then
-		return
-	fi
-
-	# FIXME: stop hardcoding overloading of initramfs-tools functions
-	. /scripts/functions
-	. /lib/live/boot/initramfs-tools.sh
-
-	dirs="$(sed -e '/^ *$/d' -e '/^#.*$/d' /root/etc/live-persistence.binds | tr '\n' '\0')"
-	if [ -z "${dirs}" ]
-	then
-		return
-	fi
-
-	log_begin_msg "Moving persistence bind mounts"
-
-	PERSTMP="/root/live/persistence-binds"
-	CPIO="/bin/cpio"
-
-	if [ ! -d "${PERSTMP}" ]
-	then
-		mkdir -p "${PERSTMP}"
-	fi
-
-	mount -t tmpfs tmpfs "${PERSTMP}"
-
-	for dir in $(echo "${dirs}" | tr '\0' '\n')
-	do
-		if [ ! -e "/root/${dir}" ] && [ ! -L "/root/${dir}" ]
-		then
-			# directory do not exists, create it
-			mkdir -p "/root/${dir}"
-		elif [ ! -d "/root/${dir}" ]
-		then
-			# it is not a directory, skip it
-			break
-		fi
-
-		# Copy previous content if any
-		cd "/root/${dir}"
-		find . -print0 | ${CPIO} -pumd0 "${PERSTMP}/${dir}"
-		cd "${OLDPWD}"
-
-		# Bind mount it to origin
-		mount -o bind "${PERSTMP}/${dir}" "/root/${dir}"
-	done
-
-	log_end_msg
-}
diff --git a/scripts/boot/snapshot.sh b/scripts/boot/snapshot.sh
deleted file mode 100755
index 568fda7..0000000
--- a/scripts/boot/snapshot.sh
+++ /dev/null
@@ -1,173 +0,0 @@
-#!/bin/sh
-
-#set -e
-
-do_snap_copy ()
-{
-	fromdev="${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
-}