Adding debian version 2.0~a1-1.
[live-boot-grml.git] / bin / live-snapshot
index 67e853a..1e080c3 100755 (executable)
@@ -3,15 +3,16 @@
 # 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-boot 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>
 #
-# This program is free software; you can redistribute it and/or modify
+# This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or
+# the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
 #
 # On Debian systems, the complete text of the GNU General Public License
-# can be found in /usr/share/common-licenses/GPL-2 file.
+# can be found in /usr/share/common-licenses/GPL-3 file.
 
 # declare here two vars from /etc/live.conf because of "set -u"
 ROOTSNAP=""
 HOMESNAP=""
 
-set -eu
+if [ -n "${LIVE_SNAPSHOT_CHECK_UNBOUND}" ]
+then
+       set -eu
+else
+       set -e
+fi
 
 . /usr/share/initramfs-tools/scripts/live-helpers
 
@@ -48,13 +53,18 @@ SAFE_TMPDIR="/live"
 # 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 ()
 {
@@ -90,7 +100,7 @@ Help ()
        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."
 
@@ -228,11 +238,12 @@ Defaults ()
        # Parse resync string
        if [ -n "${SNAP_RESYNC_STRING}" ]
        then
-               SNAP_COW=$(echo "${SNAP_RESYNC_STRING}" | cut -f1 -d ':')
+               SNAP_COW=$(echo "${SNAP_RESYNC_STRING}" | sed -e 's|^/root\([^:.]*\).*$|'"${DEF_SNAP_COW}"'\1|')
                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"
                                ;;
@@ -245,9 +256,18 @@ Defaults ()
                                SNAP_TYPE="jffs2"
                                ;;
 
-                       ""|*.ext2|*.ext3)
+                       *.ext2|*.ext3)
                                SNAP_TYPE="ext2"
                                ;;
+
+                       "")
+                               SNAP_TYPE="whole_partition"
+                               ;;
+
+                       *.ext4)
+                               SNAP_TYPE="ext4"
+                               ;;
+
                        *)
                                Error "unrecognized resync string"
                                ;;
@@ -267,6 +287,10 @@ Defaults ()
                        ext3)
                                DEST="${MOUNTP}/live-sn.ext2"
                                ;;
+
+                       ext4)
+                               DEST="${MOUNTP}/live-sn.ext4"
+                               ;;
                esac
        else
                DEST="${SNAP_OUTPUT}"
@@ -276,7 +300,7 @@ Defaults ()
 Validate_input ()
 {
        case "${SNAP_TYPE}" in
-               cpio|squashfs|jffs2|ext2|ext3)
+               cpio|squashfs|jffs2|ext2|ext3|ext4|whole_partition)
                        ;;
 
                *)
@@ -312,24 +336,124 @@ Mount_device ()
        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=$(echo "${SNAP_COW}" | sed -e "s|${DEF_SNAP_COW}||g")
+               if [ -z "${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' | \
+                                       eval $COPY_CMD || exit 1
+                       else
+                               cat "${TMP_FILELIST}" | \
+                                       eval $COPY_CMD || exit 1
+                       fi
+                       cd "${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}"
@@ -339,6 +463,11 @@ Do_snapshot ()
                        mkfs.jffs2 --root="${SNAP_COW}" --output="${DEST}"
                        ;;
        esac
+
+       if [ -f "${TMP_FILELIST}" ]
+       then
+               rm -f "${TMP_FILELIST}"
+       fi
 }
 
 Clean ()
@@ -352,6 +481,33 @@ 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 ${DEST} to your partition in order to start using it." > /dev/null 1>&2
+                               ;;
+               esac
+
+               if grep -qv persistent /proc/cmdline
+               then
+                       echo "Remember to boot this live system with \"persistent\" specified at boot prompt." > /dev/null 1>&2
+               fi
+       fi
+}
+
 Main ()
 {
        Parse_args "${@}"
@@ -360,6 +516,7 @@ Main ()
        trap 'Clean' EXIT
        Mount_device
        Do_snapshot
+       Warn_user
 }
 
 Main "${@:-}"