Reorganizing components in source tree.
[live-boot-grml.git] / components / 9990-overlay.sh
diff --git a/components/9990-overlay.sh b/components/9990-overlay.sh
new file mode 100755 (executable)
index 0000000..6b62093
--- /dev/null
@@ -0,0 +1,406 @@
+#!/bin/sh
+
+#set -e
+
+setup_unionfs ()
+{
+       image_directory="${1}"
+       rootmnt="${2}"
+       addimage_directory="${3}"
+
+       case ${UNIONTYPE} in
+               aufs|unionfs|overlayfs)
+                       modprobe -q -b ${UNIONTYPE}
+
+                       if ! cut -f2 /proc/filesystems | grep -q "^${UNIONTYPE}\$" && [ -x /bin/unionfs-fuse ]
+                       then
+                               echo "${UNIONTYPE} not available, falling back to unionfs-fuse."
+                               echo "This might be really slow."
+
+                               UNIONTYPE="unionfs-fuse"
+                       fi
+                       ;;
+       esac
+
+       case "${UNIONTYPE}" in
+               unionfs-fuse)
+                       modprobe fuse
+                       ;;
+       esac
+
+       # run-init can't deal with images in a subdir, but we're going to
+       # move all of these away before it runs anyway.  No, we're not,
+       # put them in / since move-mounting them into / breaks mono and
+       # some other apps.
+
+       croot="/"
+
+       # Let's just mount the read-only file systems first
+       rootfslist=""
+
+       if [ -z "${PLAIN_ROOT}" ]
+       then
+               # Read image names from ${MODULE}.module if it exists
+               if [ -e "${image_directory}/filesystem.${MODULE}.module" ]
+               then
+                       for IMAGE in $(cat ${image_directory}/filesystem.${MODULE}.module)
+                       do
+                               image_string="${image_string} ${image_directory}/${IMAGE}"
+                       done
+               elif [ -e "${image_directory}/${MODULE}.module" ]
+               then
+                       for IMAGE in $(cat ${image_directory}/${MODULE}.module)
+                       do
+                               image_string="${image_string} ${image_directory}/${IMAGE}"
+                       done
+               else
+                       # ${MODULE}.module does not exist, create a list of images
+                       for FILESYSTEM in squashfs ext2 ext3 ext4 xfs jffs2 dir
+                       do
+                               for IMAGE in "${image_directory}"/*."${FILESYSTEM}"
+                               do
+                                       if [ -e "${IMAGE}" ]
+                                       then
+                                               image_string="${image_string} ${IMAGE}"
+                                       fi
+                               done
+                       done
+
+                       if [ -n "${addimage_directory}" ] && [ -d "${addimage_directory}" ]
+                       then
+                               for FILESYSTEM in squashfs ext2 ext3 ext4 xfs jffs2 dir
+                               do
+                                       for IMAGE in "${addimage_directory}"/*."${FILESYSTEM}"
+                                       do
+                                               if [ -e "${IMAGE}" ]
+                                               then
+                                                       image_string="${image_string} ${IMAGE}"
+                                               fi
+                                       done
+                               done
+                       fi
+
+                       # Now sort the list
+                       image_string="$(echo ${image_string} | sed -e 's/ /\n/g' | sort )"
+               fi
+
+               [ -n "${MODULETORAMFILE}" ] && image_string="${image_directory}/$(basename ${MODULETORAMFILE})"
+
+               mkdir -p "${croot}"
+
+               for image in ${image_string}
+               do
+                       imagename=$(basename "${image}")
+
+                       export image devname
+                       maybe_break live-realpremount
+                       log_begin_msg "Running /scripts/live-realpremount"
+                       run_scripts /scripts/live-realpremount
+                       log_end_msg
+
+                       if [ -d "${image}" ]
+                       then
+                               # it is a plain directory: do nothing
+                               rootfslist="${image} ${rootfslist}"
+                       elif [ -f "${image}" ]
+                       then
+                               if losetup --help 2>&1 | grep -q -- "-r\b"
+                               then
+                                       backdev=$(get_backing_device "${image}" "-r")
+                               else
+                                       backdev=$(get_backing_device "${image}")
+                               fi
+                               fstype=$(get_fstype "${backdev}")
+
+                               case "${fstype}" in
+                                       unknown)
+                                               panic "Unknown file system type on ${backdev} (${image})"
+                                               ;;
+
+                                       "")
+                                               fstype="${imagename##*.}"
+                                               log_warning_msg "Unknown file system type on ${backdev} (${image}), assuming ${fstype}."
+                                               ;;
+                               esac
+
+                               case "${UNIONTYPE}" in
+                                       unionmount)
+                                               mpoint="${rootmnt}"
+                                               rootfslist="${rootmnt} ${rootfslist}"
+                                               ;;
+
+                                       *)
+                                               mpoint="${croot}/${imagename}"
+                                               rootfslist="${mpoint} ${rootfslist}"
+                                               ;;
+                               esac
+
+                               mkdir -p "${mpoint}"
+                               log_begin_msg "Mounting \"${image}\" on \"${mpoint}\" via \"${backdev}\""
+                               mount -t "${fstype}" -o ro,noatime "${backdev}" "${mpoint}" || panic "Can not mount ${backdev} (${image}) on ${mpoint}"
+                               log_end_msg
+                       fi
+               done
+       else
+               # we have a plain root system
+               mkdir -p "${croot}/filesystem"
+               log_begin_msg "Mounting \"${image_directory}\" on \"${croot}/filesystem\""
+               mount -t $(get_fstype "${image_directory}") -o ro,noatime "${image_directory}" "${croot}/filesystem" || \
+                       panic "Can not mount ${image_directory} on ${croot}/filesystem" && \
+                       rootfslist="${croot}/filesystem ${rootfslist}"
+               # probably broken:
+               mount -o bind ${croot}/filesystem $mountpoint
+               log_end_msg
+       fi
+
+       # tmpfs file systems
+       touch /etc/fstab
+       mkdir -p /live/overlay
+       mount -t tmpfs tmpfs /live/overlay
+
+       # Looking for persistence devices or files
+       if [ -n "${PERSISTENCE}" ] && [ -z "${NOPERSISTENCE}" ]
+       then
+
+               if [ -z "${QUICKUSBMODULES}" ]
+               then
+                       # Load USB modules
+                       num_block=$(ls -l /sys/block | wc -l)
+                       for module in sd_mod uhci-hcd ehci-hcd ohci-hcd usb-storage
+                       do
+                               modprobe -q -b ${module}
+                       done
+
+                       udevadm trigger
+                       udevadm settle
+
+                       # For some reason, udevsettle does not block in this scenario,
+                       # so we sleep for a little while.
+                       #
+                       # See https://bugs.launchpad.net/ubuntu/+source/casper/+bug/84591
+                       for timeout in 5 4 3 2 1
+                       do
+                               sleep 1
+
+                               if [ $(ls -l /sys/block | wc -l) -gt ${num_block} ]
+                               then
+                                       break
+                               fi
+                       done
+               fi
+
+               local whitelistdev
+               whitelistdev=""
+               if [ -n "${PERSISTENCE_MEDIA}" ]
+               then
+                       case "${PERSISTENCE_MEDIA}" in
+                               removable)
+                                       whitelistdev="$(removable_dev)"
+                                       ;;
+
+                               removable-usb)
+                                       whitelistdev="$(removable_usb_dev)"
+                                       ;;
+                       esac
+                       if [ -z "${whitelistdev}" ]
+                       then
+                               whitelistdev="ignore_all_devices"
+                       fi
+               fi
+
+               if is_in_comma_sep_list overlay ${PERSISTENCE_METHOD}
+               then
+                       overlays="${custom_overlay_label}"
+               fi
+
+               local overlay_devices
+               overlay_devices=""
+               if [ "${whitelistdev}" != "ignore_all_devices" ]
+               then
+                       for media in $(find_persistence_media "${overlays}" "${whitelistdev}")
+                       do
+                               media="$(echo ${media} | tr ":" " ")"
+
+                               case ${media} in
+                                       ${custom_overlay_label}=*)
+                                               device="${media#*=}"
+                                               overlay_devices="${overlay_devices} ${device}"
+                                               ;;
+                                esac
+                       done
+               fi
+       elif [ -n "${NFS_COW}" ] && [ -z "${NOPERSISTENCE}" ]
+       then
+               # check if there are any nfs options
+               if echo ${NFS_COW} | grep -q ','
+               then
+                       nfs_cow_opts="-o nolock,$(echo ${NFS_COW}|cut -d, -f2-)"
+                       nfs_cow=$(echo ${NFS_COW}|cut -d, -f1)
+               else
+                       nfs_cow_opts="-o nolock"
+                       nfs_cow=${NFS_COW}
+               fi
+
+               if [ -n "${PERSISTENCE_READONLY}" ]
+               then
+                       nfs_cow_opts="${nfs_cow_opts},nocto,ro"
+               fi
+
+               mac="$(get_mac)"
+               if [ -n "${mac}" ]
+               then
+                       cowdevice=$(echo ${nfs_cow} | sed "s/client_mac_address/${mac}/")
+                       cow_fstype="nfs"
+               else
+                       panic "unable to determine mac address"
+               fi
+       fi
+
+       if [ -z "${cowdevice}" ]
+       then
+               cowdevice="tmpfs"
+               cow_fstype="tmpfs"
+               cow_mountopt="rw,noatime,mode=755"
+       fi
+
+       if [ "${UNIONTYPE}" != "unionmount" ]
+       then
+               if [ -n "${PERSISTENCE_READONLY}" ] && [ "${cowdevice}" != "tmpfs" ]
+               then
+                       mount -t tmpfs -o rw,noatime,mode=755 tmpfs "/live/overlay"
+                       root_backing="/live/persistence/$(basename ${cowdevice})-root"
+                       mkdir -p ${root_backing}
+               else
+                       root_backing="/live/overlay"
+               fi
+
+               if [ "${cow_fstype}" = "nfs" ]
+               then
+                       log_begin_msg \
+                               "Trying nfsmount ${nfs_cow_opts} ${cowdevice} ${root_backing}"
+                       nfsmount ${nfs_cow_opts} ${cowdevice} ${root_backing} || \
+                               panic "Can not mount ${cowdevice} (n: ${cow_fstype}) on ${root_backing}"
+               else
+                       mount -t ${cow_fstype} -o ${cow_mountopt} ${cowdevice} ${root_backing} || \
+                               panic "Can not mount ${cowdevice} (o: ${cow_fstype}) on ${root_backing}"
+               fi
+       fi
+
+       rootfscount=$(echo ${rootfslist} |wc -w)
+
+       rootfs=${rootfslist%% }
+
+       if [ -n "${EXPOSED_ROOT}" ]
+       then
+               if [ ${rootfscount} -ne 1 ]
+               then
+                       panic "only one RO file system supported with exposedroot: ${rootfslist}"
+               fi
+
+               mount --bind ${rootfs} ${rootmnt} || \
+                       panic "bind mount of ${rootfs} failed"
+
+               if [ -z "${SKIP_UNION_MOUNTS}" ]
+               then
+                       cow_dirs='/var/tmp /var/lock /var/run /var/log /var/spool /home /var/lib/live'
+               else
+                       cow_dirs=''
+               fi
+       else
+               cow_dirs="/"
+       fi
+
+       if [ "${cow_fstype}" != "tmpfs" ] && [ "${cow_dirs}" != "/" ] && [ "${UNIONTYPE}" = "unionmount" ]
+       then
+               true # FIXME: Maybe it does, I don't really know.
+               #panic "unionmount does not support subunions (${cow_dirs})."
+       fi
+
+       for dir in ${cow_dirs}; do
+               unionmountpoint="${rootmnt}${dir}"
+               mkdir -p ${unionmountpoint}
+               if [ "${UNIONTYPE}" = "unionmount" ]
+               then
+                       # FIXME: handle PERSISTENCE_READONLY
+                       unionmountopts="-t ${cow_fstype} -o noatime,union,${cow_mountopt} ${cowdevice}"
+                       # unionmount only works with util-linux mount
+                       mount.util-linux $unionmountopts "${unionmountpoint}"
+               else
+                       cow_dir="/live/overlay${dir}"
+                       rootfs_dir="${rootfs}${dir}"
+                       mkdir -p ${cow_dir}
+                       if [ -n "${PERSISTENCE_READONLY}" ] && [ "${cowdevice}" != "tmpfs" ]
+                       then
+                               do_union ${unionmountpoint} ${cow_dir} ${root_backing} ${rootfs_dir}
+                       else
+                               do_union ${unionmountpoint} ${cow_dir} ${rootfs_dir}
+                       fi
+               fi || panic "mount ${UNIONTYPE} on ${unionmountpoint} failed with option ${unionmountopts}"
+       done
+
+       # Correct the permissions of /:
+       chmod 0755 "${rootmnt}"
+
+       # Correct the permission of /tmp:
+       if [ -d "${rootmnt}/tmp" ]
+       then
+               chmod 1777 "${rootmnt}"/tmp
+       fi
+
+       live_rootfs_list=""
+       for d in ${rootfslist}
+       do
+               live_rootfs="/live/rootfs/${d##*/}"
+               live_rootfs_list="${live_rootfs_list} ${live_rootfs}"
+               mkdir -p "${live_rootfs}"
+               case d in
+                       *.dir)
+                               # do nothing # mount -o bind "${d}" "${live_rootfs}"
+                               ;;
+                       *)
+                               case "${UNIONTYPE}" in
+                                       unionfs-fuse)
+                                               mount -o bind "${d}" "${live_rootfs}"
+                                               ;;
+
+                                       *)
+                                               mount -o move "${d}" "${live_rootfs}"
+                                               ;;
+                               esac
+                               ;;
+               esac
+       done
+
+       # Adding custom persistence
+       if [ -n "${PERSISTENCE}" ] && [ -z "${NOPERSISTENCE}" ]
+       then
+               local custom_mounts
+               custom_mounts="/tmp/custom_mounts.list"
+               rm -rf ${custom_mounts} 2> /dev/null
+
+               # Gather information about custom mounts from devies detected as overlays
+               get_custom_mounts ${custom_mounts} ${overlay_devices}
+
+               [ -n "${LIVE_BOOT_DEBUG}" ] && cp ${custom_mounts} "/lib/live/mount/persistence"
+
+               # Now we do the actual mounting (and symlinking)
+               local used_overlays
+               used_overlays=""
+               used_overlays=$(activate_custom_mounts ${custom_mounts})
+               rm ${custom_mounts}
+
+               # Close unused overlays (e.g. due to missing $persistence_list)
+               for overlay in ${overlay_devices}
+               do
+                       if echo ${used_overlays} | grep -qve "^\(.* \)\?${overlay}\( .*\)\?$"
+                       then
+                               close_persistence_media ${overlay}
+                       fi
+               done
+       fi
+
+        # ensure that a potentially stray tmpfs gets removed
+        # otherways, initramfs-tools is unable to remove /live
+        # and fails to boot
+        umount /live/overlay > /dev/null 2>&1 || true
+}