# live-snapshot - utility to manage Debian Live systems snapshots
#
# This program mounts a device (fallback to /tmpfs under $MOUNTP
-# and saves the /live/cow (or a different dir) filesystem in it for reuse
-# in another live-initramfs session. Look at manpage for more info.
+# and saves the /live/cow (or a different directory) filesystem in it
+# for reuse in another live-initramfs session.
+# Look at the manpage for more informations.
#
# Copyright (C) 2006-2008 Marco Amadori <marco.amadori@gmail.com>
# Copyright (C) 2008 Chris Lamb <chris@chris-lamb.co.uk>
ROOTSNAP=""
HOMESNAP=""
-set -eu
+if [ -n "${LIVE_SNAPSHOT_CHECK_UNBOUND}" ]
+then
+ set -eu
+else
+ set -e
+fi
. /usr/share/initramfs-tools/scripts/live-helpers
# Permits multiple runs
MOUNTP="$(mktemp -d -p ${SAFE_TMPDIR} live-snapshot-mnt.XXXXXX)"
DEST="${MOUNTP}/live-sn.cpio.gz"
+DEF_SNAP_COW="/live/cow"
+TMP_FILELIST="${PROGRAM}.list"
# Command line defaults and declarations
-SNAP_COW="/live/cow"
+SNAP_COW="${DEF_SNAP_COW}"
SNAP_DEV=""
+SNAP_MNT=""
SNAP_OUTPUT=""
SNAP_RESYNC_STRING=""
SNAP_TYPE="cpio"
+SNAP_LIST="/etc/live-snapshot.list"
+EXCLUDE_LIST="/etc/live-snapshot.exclude_list"
Error ()
{
echo " -o, --output: output image file (default: ${DEST})."
echo " -r, --resync-string: internally used to resync previous made snapshots."
echo " -f, --refresh: try to sync a running snapshot."
- echo " -t, --type: snapshot filesystem type. Options: \"squashfs\", \"ext2\", \"ext3\", \"jffs2\" or \"cpio\".gz archive (default: ${SNAP_TYPE})"
+ echo " -t, --type: snapshot filesystem type. Options: \"squashfs\", \"ext2\", \"ext3\", \"ext4\", \"jffs2\" or \"cpio\".gz archive (default: ${SNAP_TYPE})"
echo
echo "Look at live-snapshot(1) man page for more information."
# Parse resync string
if [ -n "${SNAP_RESYNC_STRING}" ]
then
- SNAP_COW=$(echo "${SNAP_RESYNC_STRING}" | cut -f1 -d ':')
+ SNAP_COW=$(echo "${SNAP_RESYNC_STRING/\/root/${DEF_SNAP_COW}}" | cut -f1 -d ':')
SNAP_DEV=$(echo "${SNAP_RESYNC_STRING}" | cut -f2 -d ':')
- DEST="${MOUNTP}/$(echo ${SNAP_RESYNC_STRING} | cut -f3 -d ':')"
+ SNAP_MNT=$(echo "${SNAP_RESYNC_STRING}" | cut -f3 -d ':')
+ DEST="${MOUNTP}/${SNAP_MNT}"
- case "${DEST}" in
+ case "${SNAP_MNT}" in
*.cpio.gz)
SNAP_TYPE="cpio"
;;
SNAP_TYPE="jffs2"
;;
- ""|*.ext2|*.ext3)
+ *.ext2|*.ext3)
SNAP_TYPE="ext2"
;;
+
+ "")
+ SNAP_TYPE="whole_partition"
+ ;;
+
+ *.ext4)
+ SNAP_TYPE="ext4"
+ ;;
+
*)
Error "unrecognized resync string"
;;
ext3)
DEST="${MOUNTP}/live-sn.ext2"
;;
+
+ ext4)
+ DEST="${MOUNTP}/live-sn.ext4"
+ ;;
esac
else
DEST="${SNAP_OUTPUT}"
Validate_input ()
{
case "${SNAP_TYPE}" in
- cpio|squashfs|jffs2|ext2|ext3)
+ cpio|squashfs|jffs2|ext2|ext3|ext4|whole_partition)
;;
*)
esac
}
+Entry_is_modified ()
+{
+ # Returns true if file exists and it is also present in "cow" directory
+ # This means it is modified in respect to read-only media, so it deserve
+ # to be saved
+
+ entry="${1}"
+
+ if [ -e "${entry}" ] || [ -L "${entry}" ]
+ then
+ if [ -e "${SNAP_COW}/${entry}" ] || [ -L "${SNAP_COW}/${entry}" ]
+ then
+ return 0
+ fi
+ fi
+ return 1
+}
+
+Do_filelist ()
+{
+ # BUGS: does not handle deleted files yet
+ TMP_FILELIST=$1
+
+ if [ -f "${SNAP_LIST}" ]
+ then
+ # if SNAP_COW == /live/cow/home, SNAP_RW = /home
+ SNAP_RW="${SNAP_COW/${DEF_SNAP_COW}}"
+ if [ -z "${SNAP_RW}" ]
+ then
+ SNAP_RW="/"
+ fi
+
+ cd "${SNAP_RW}"
+ # Generate include list removing empty and commented lines
+ # and transforming paths to relatives
+ for entry in $(sed -e '/^ *$/d' -e '/^#.*$/d' -e 's#^.*$#./&#' -e 's#/\+#/#g' "${SNAP_LIST}")
+ do
+ if [ -d "${entry}" ]
+ then
+ find "${entry}" | while read line
+ do
+ if Entry_is_modified "${line}"
+ then
+ printf "%s\000" "${line}" >> "${TMP_FILELIST}"
+ fi
+ done
+ elif Entry_is_modified "${entry}"
+ then
+ # if file exists and it is modified
+ printf "%s\000" "${entry}" >> "${TMP_FILELIST}"
+ fi
+ done
+ cd "${OLDPWD}"
+
+ # echo Working dir
+ echo "${SNAP_RW}"
+ else
+ cd "${SNAP_COW}"
+ # removing whiteouts from list
+ find . -path '*.wh.*' -prune -o -print0 >> "${TMP_FILELIST}"
+ cd "${OLDPWD}"
+ # echo Working dir
+ echo "${SNAP_COW}"
+ fi
+}
+
Do_snapshot ()
{
+ TMP_FILELIST=$(mktemp -p "${SAFE_TMPDIR}" "${TMP_FILELIST}.XXXXXX")
+
case "${SNAP_TYPE}" in
squashfs)
- EXCLUDE_LIST="$(mktemp -p ${SAFE_TMPDIR} live-snapshot-exclude-list.XXXXXX)"
- echo "./${EXCLUDE_LIST}" > "${EXCLUDE_LIST}"
+ echo ".${TMP_FILELIST}" > "${TMP_FILELIST}"
+ # Removing whiteheads of unionfs
cd "${SNAP_COW}"
- find . -name '*.wh.*' >> "${EXCLUDE_LIST}"
+ find . -name '*.wh.*' >> "${TMP_FILELIST}"
+
+ if [ -e "${EXCLUDE_LIST}" ]
+ then
+ # Add explicitly excluded files
+ grep -v '^#.*$' "${EXCLUDE_LIST}" | grep -v '^ *$' >> "${TMP_FILELIST}"
+ fi
+
cd "${OLDPWD}"
- mksquashfs "${SNAP_COW}" "${DEST}" -ef "${EXCLUDE_LIST}"
- rm -f "${EXCLUDE_LIST}"
+ mksquashfs "${SNAP_COW}" "${DEST}" -ef "${TMP_FILELIST}"
;;
- cpio)
- ( cd "${SNAP_COW}" && find . -path '*.wh.*' -prune -o -print0 | cpio --quiet -o0 -H newc | gzip -9c > "${DEST}" ) || exit 1
+ cpio|whole_partition)
+ if [ "${SNAP_TYPE}" = "cpio" ]
+ then
+ COPY_CMD="cpio --quiet -o0 -H newc | gzip -9c > ${DEST}"
+ else
+ COPY_CMD="cpio --quiet -pumd0 ${DEST}/"
+ fi
+
+ WORKING_DIR=$(Do_filelist "${TMP_FILELIST}")
+ cd "${WORKING_DIR}"
+ if [ -e "${EXCLUDE_LIST}" ]
+ then
+ # Convert \0 to \n and tag existing (rare but possible) \n in filenames,
+ # this to let grep -F -v do a proper work in filtering out
+ cat "${TMP_FILELIST}" | \
+ tr '\n' '\1' | \
+ tr '\0' '\n' | \
+ grep -F -v -f "${EXCLUDE_LIST}" | \
+ tr '\n' '\0' | \
+ tr '\1' '\n' | \
+ $COPY_CMD || exit 1
+ else
+ cat "${TMP_FILELIST}" | \
+ $COPY_CMD || exit 1
+ fi
+ cd "${OLDPWD}"
;;
- ext2|ext3)
+ # ext2|ext3|ext4 and jffs2 does not easily support an exclude list; files
+ # should be copied to another directory in order to filter content
+ ext2|ext3|ext4)
DU_DIM="$(du -ks ${SNAP_COW} | cut -f1)"
REAL_DIM="$(expr ${DU_DIM} + ${DU_DIM} / 20)" # Just 5% more to be sure, need something more sophistcated here...
genext2fs --size-in-blocks=${REAL_DIM} --reserved-percentage=0 --root="${SNAP_COW}" "${DEST}"
mkfs.jffs2 --root="${SNAP_COW}" --output="${DEST}"
;;
esac
+
+ if [ -f "${TMP_FILELIST}" ]
+ then
+ rm -f "${TMP_FILELIST}"
+ fi
}
Clean ()
fi
}
+Warn_user ()
+{
+ if [ -z "${SNAP_RESYNC_STRING}" ]
+ then
+ case ${SNAP_TYPE} in
+ cpio|ext2|ext3|ext4)
+ echo "Please move ${DEST} (if is not already in it)" > /dev/null 1>&2
+ echo "in a supported writable partition (e.g ext3, vfat)." > /dev/null 1>&2
+ ;;
+
+ squashfs)
+ echo "To use ${DEST} you need to rebuild your media or add it" > /dev/null 1>&2
+ echo "to your multisession disc under the \"/live\" directory." > /dev/null 1>&2
+ ;;
+
+ jffs2)
+ echo "Please cat or flashcp ${DEST} to your partition in order to start using it." > /dev/null 1>&2
+ ;;
+ esac
+
+ if grep -qv persistent /proc/cmdline
+ then
+ echo "Remember to boot this live system with \"persistent\" specified at boot prompt." > /dev/null 1>&2
+ fi
+ fi
+}
+
Main ()
{
Parse_args "${@}"
trap 'Clean' EXIT
Mount_device
Do_snapshot
+ Warn_user
}
Main "${@:-}"