components/9990-misc-helpers.sh

   1 #!/bin/sh
   2
   3 #set -e
   4
   5 is_live_path()
   6 {
   7         DIRECTORY="${1}/${LIVE_MEDIA_PATH}"
   8         for FILESYSTEM in squashfs ext2 ext3 ext4 xfs dir jffs
   9         do
  10                 if ls "${DIRECTORY}/"*.${FILESYSTEM} > /dev/null 2>&1
  11                 then
  12                         return 0
  13                 fi
  14         done
  15         return 1
  16 }
  17
  18 matches_uuid ()
  19 {
  20         if [ "${IGNORE_UUID}" ] || [ ! -e /conf/uuid.conf ]
  21         then
  22                 return 0
  23         fi
  24
  25         path="${1}"
  26         uuid="$(cat /conf/uuid.conf)"
  27
  28         for try_uuid_file in "${path}/.disk/live-uuid"*
  29         do
  30                 [ -e "${try_uuid_file}" ] || continue
  31
  32                 try_uuid="$(cat "${try_uuid_file}")"
  33
  34                 if [ "${uuid}" = "${try_uuid}" ]
  35                 then
  36                         return 0
  37                 fi
  38         done
  39
  40         return 1
  41 }
  42
  43 get_backing_device ()
  44 {
  45         case "${1}" in
  46                 *.squashfs|*.ext2|*.ext3|*.ext4|*.jffs2)
  47                         echo $(setup_loop "${1}" "loop" "/sys/block/loop*" '0' "${LIVE_MEDIA_ENCRYPTION}" "${2}")
  48                         ;;
  49
  50                 *.dir)
  51                         echo "directory"
  52                         ;;
  53
  54                 *)
  55                         panic "Unrecognized live filesystem: ${1}"
  56                         ;;
  57         esac
  58 }
  59
  60 mount_images_in_directory ()
  61 {
  62         directory="${1}"
  63         rootmnt="${2}"
  64         mac="${3}"
  65
  66         if is_live_path "${directory}"
  67         then
  68                 [ -n "${mac}" ] && adddirectory="${directory}/${LIVE_MEDIA_PATH}/${mac}"
  69                 setup_unionfs "${directory}/${LIVE_MEDIA_PATH}" "${rootmnt}" "${adddirectory}"
  70         else
  71                 panic "No supported filesystem images found at /${LIVE_MEDIA_PATH}."
  72         fi
  73 }
  74
  75 is_nice_device ()
  76 {
  77         sysfs_path="${1#/sys}"
  78
  79         if udevadm test-builtin path_id "${sysfs_path}" | egrep -q "ID_PATH=(usb|pci-[^-]*-(ide|sas|scsi|usb|virtio)|platform-sata_mv|platform-orion-ehci|platform-mmc|platform-mxsdhci)"
  80         then
  81                 return 0
  82         elif echo "${sysfs_path}" | grep -q '^/block/vd[a-z]$'
  83         then
  84                 return 0
  85         elif echo ${sysfs_path} | grep -q "^/block/dm-"
  86         then
  87                 return 0
  88         elif echo ${sysfs_path} | grep -q "^/block/mtdblock"
  89         then
  90                 return 0
  91         fi
  92
  93         return 1
  94 }
  95
  96 check_dev ()
  97 {
  98         sysdev="${1}"
  99         devname="${2}"
 100         skip_uuid_check="${3}"
 101
 102         # support for fromiso=.../isofrom=....
 103         if [ -n "$FROMISO" ]
 104         then
 105                 ISO_DEVICE=$(dirname $FROMISO)
 106                 if ! [ -b $ISO_DEVICE ]
 107                 then
 108                         # to support unusual device names like /dev/cciss/c0d0p1
 109                         # as well we have to identify the block device name, let's
 110                         # do that for up to 15 levels
 111                         i=15
 112                         while [ -n "$ISO_DEVICE" ] && [ "$i" -gt 0 ]
 113                         do
 114                                 ISO_DEVICE=$(dirname ${ISO_DEVICE})
 115                                 [ -b "$ISO_DEVICE" ] && break
 116                                 i=$(($i -1))
 117                         done
 118                 fi
 119
 120                 if [ "$ISO_DEVICE" = "/" ]
 121                 then
 122                         echo "Warning: device for bootoption fromiso= ($FROMISO) not found.">>/boot.log
 123                 else
 124                         fs_type=$(get_fstype "${ISO_DEVICE}")
 125                         if is_supported_fs ${fs_type}
 126                         then
 127                                 mkdir /live/fromiso
 128                                 mount -t $fs_type "$ISO_DEVICE" /live/fromiso
 129                                 ISO_NAME="$(echo $FROMISO | sed "s|$ISO_DEVICE||")"
 130                                 loopdevname=$(setup_loop "/live/fromiso/${ISO_NAME}" "loop" "/sys/block/loop*" "" '')
 131                                 devname="${loopdevname}"
 132                         else
 133                                 echo "Warning: unable to mount $ISO_DEVICE." >>/boot.log
 134                         fi
 135                 fi
 136         fi
 137
 138         if [ -z "${devname}" ]
 139         then
 140                 devname=$(sys2dev "${sysdev}")
 141         fi
 142
 143         if [ -d "${devname}" ]
 144         then
 145                 mount -o bind "${devname}" $mountpoint || continue
 146
 147                 if is_live_path $mountpoint
 148                 then
 149                         echo $mountpoint
 150                         return 0
 151                 else
 152                         umount $mountpoint
 153                 fi
 154         fi
 155
 156         IFS=","
 157         for device in ${devname}
 158         do
 159                 case "$device" in
 160                         *mapper*)
 161                                 # Adding lvm support
 162                                 if [ -x /scripts/local-top/lvm2 ]
 163                                 then
 164                                         ROOT="$device" resume="" /scripts/local-top/lvm2
 165                                 fi
 166                                 ;;
 167
 168                         /dev/md*)
 169                                 # Adding raid support
 170                                 if [ -x /scripts/local-top/mdadm ]
 171                                 then
 172                                         cp /conf/conf.d/md /conf/conf.d/md.orig
 173                                         echo "MD_DEVS=$device " >> /conf/conf.d/md
 174                                         /scripts/local-top/mdadm
 175                                         mv /conf/conf.d/md.orig /conf/conf.d/md
 176                                 fi
 177                                 ;;
 178                 esac
 179         done
 180         unset IFS
 181
 182         [ -n "$device" ] && devname="$device"
 183
 184         [ -e "$devname" ] || continue
 185
 186         if [ -n "${LIVE_MEDIA_OFFSET}" ]
 187         then
 188                 loopdevname=$(setup_loop "${devname}" "loop" "/sys/block/loop*" "${LIVE_MEDIA_OFFSET}" '')
 189                 devname="${loopdevname}"
 190         fi
 191
 192         fstype=$(get_fstype "${devname}")
 193
 194         if is_supported_fs ${fstype}
 195         then
 196                 devuid=$(blkid -o value -s UUID "$devname")
 197                 [ -n "$devuid" ] && grep -qs "\<$devuid\>" /var/lib/live/boot/devices-already-tried-to-mount && continue
 198                 mount -t ${fstype} -o ro,noatime "${devname}" ${mountpoint} || continue
 199                 [ -n "$devuid" ] && echo "$devuid" >> /var/lib/live/boot/devices-already-tried-to-mount
 200
 201                 if [ -n "${FINDISO}" ]
 202                 then
 203                         if [ -f ${mountpoint}/${FINDISO} ]
 204                         then
 205                                 umount ${mountpoint}
 206                                 mkdir -p /live/findiso
 207                                 mount -t ${fstype} -o ro,noatime "${devname}" /live/findiso
 208                                 loopdevname=$(setup_loop "/live/findiso/${FINDISO}" "loop" "/sys/block/loop*" 0 "")
 209                                 devname="${loopdevname}"
 210                                 mount -t iso9660 -o ro,noatime "${devname}" ${mountpoint}
 211                         else
 212                                 umount ${mountpoint}
 213                         fi
 214                 fi
 215
 216                 if is_live_path ${mountpoint} && \
 217                         ([ "${skip_uuid_check}" ] || matches_uuid ${mountpoint})
 218                 then
 219                         echo ${mountpoint}
 220                         return 0
 221                 else
 222                         umount ${mountpoint} 2>/dev/null
 223                 fi
 224         fi
 225
 226         if [ -n "${LIVE_MEDIA_OFFSET}" ]
 227         then
 228                 losetup -d "${loopdevname}"
 229         fi
 230
 231         return 1
 232 }
 233
 234 find_livefs ()
 235 {
 236         timeout="${1}"
 237
 238         # don't start autodetection before timeout has expired
 239         if [ -n "${LIVE_MEDIA_TIMEOUT}" ]
 240         then
 241                 if [ "${timeout}" -lt "${LIVE_MEDIA_TIMEOUT}" ]
 242                 then
 243                         return 1
 244                 fi
 245         fi
 246
 247         # first look at the one specified in the command line
 248         case "${LIVE_MEDIA}" in
 249                 removable-usb)
 250                         for sysblock in $(removable_usb_dev "sys")
 251                         do
 252                                 for dev in $(subdevices "${sysblock}")
 253                                 do
 254                                         if check_dev "${dev}"
 255                                         then
 256                                                 return 0
 257                                         fi
 258                                 done
 259                         done
 260                         return 1
 261                         ;;
 262
 263                 removable)
 264                         for sysblock in $(removable_dev "sys")
 265                         do
 266                                 for dev in $(subdevices "${sysblock}")
 267                                 do
 268                                         if check_dev "${dev}"
 269                                         then
 270                                                 return 0
 271                                         fi
 272                                 done
 273                         done
 274                         return 1
 275                         ;;
 276
 277                 *)
 278                         if [ ! -z "${LIVE_MEDIA}" ]
 279                         then
 280                                 if check_dev "null" "${LIVE_MEDIA}" "skip_uuid_check"
 281                                 then
 282                                         return 0
 283                                 fi
 284                         fi
 285                         ;;
 286         esac
 287
 288         # or do the scan of block devices
 289         # prefer removable devices over non-removable devices, so scan them first
 290         devices_to_scan="$(removable_dev 'sys') $(non_removable_dev 'sys')"
 291
 292         for sysblock in $devices_to_scan
 293         do
 294                 devname=$(sys2dev "${sysblock}")
 295                 [ -e "$devname" ] || continue
 296                 fstype=$(get_fstype "${devname}")
 297
 298                 if /lib/udev/cdrom_id ${devname} > /dev/null
 299                 then
 300                         if check_dev "null" "${devname}"
 301                         then
 302                                 return 0
 303                         fi
 304                 elif is_nice_device "${sysblock}"
 305                 then
 306                         for dev in $(subdevices "${sysblock}")
 307                         do
 308                                 if check_dev "${dev}"
 309                                 then
 310                                         return 0
 311                                 fi
 312                         done
 313                 elif [ "${fstype}" = "squashfs" -o \
 314                         "${fstype}" = "btrfs" -o \
 315                         "${fstype}" = "ext2" -o \
 316                         "${fstype}" = "ext3" -o \
 317                         "${fstype}" = "ext4" -o \
 318                         "${fstype}" = "jffs2" ]
 319                 then
 320                         # This is an ugly hack situation, the block device has
 321                         # an image directly on it.  It's hopefully
 322                         # live-boot, so take it and run with it.
 323                         ln -s "${devname}" "${devname}.${fstype}"
 324                         echo "${devname}.${fstype}"
 325                         return 0
 326                 fi
 327         done
 328
 329         return 1
 330 }
 331
 332 really_export ()
 333 {
 334         STRING="${1}"
 335         VALUE="$(eval echo -n \${$STRING})"
 336
 337         if [ -f /live.vars ] && grep -sq "export ${STRING}" /live.vars
 338         then
 339                 sed -i -e 's/\('${STRING}'=\).*$/\1'${VALUE}'/' /live.vars
 340         else
 341                 echo "export ${STRING}=\"${VALUE}\"" >> /live.vars
 342         fi
 343
 344         eval export "${STRING}"="${VALUE}"
 345 }
 346
 347 is_in_list_separator_helper ()
 348 {
 349         local sep element list
 350         sep=${1}
 351         shift
 352         element=${1}
 353         shift
 354         list=${*}
 355         echo ${list} | grep -qe "^\(.*${sep}\)\?${element}\(${sep}.*\)\?$"
 356 }
 357
 358 is_in_space_sep_list ()
 359 {
 360         local element
 361         element=${1}
 362         shift
 363         is_in_list_separator_helper "[[:space:]]" "${element}" "${*}"
 364 }
 365
 366 is_in_comma_sep_list ()
 367 {
 368         local element
 369         element=${1}
 370         shift
 371         is_in_list_separator_helper "," "${element}" "${*}"
 372 }
 373
 374 sys2dev ()
 375 {
 376         sysdev=${1#/sys}
 377         echo "/dev/$(udevadm info -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})"
 378 }
 379
 380 subdevices ()
 381 {
 382         sysblock=${1}
 383         r=""
 384
 385         for dev in "${sysblock}"/* "${sysblock}"
 386         do
 387                 if [ -e "${dev}/dev" ]
 388                 then
 389                         r="${r} ${dev}"
 390                 fi
 391         done
 392
 393         echo ${r}
 394 }
 395
 396 storage_devices()
 397 {
 398         black_listed_devices="${1}"
 399         white_listed_devices="${2}"
 400
 401         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "loop|ram|fd")
 402         do
 403                 fulldevname=$(sys2dev "${sysblock}")
 404
 405                 if is_in_space_sep_list ${fulldevname} ${black_listed_devices} || \
 406                         [ -n "${white_listed_devices}" ] && \
 407                         ! is_in_space_sep_list ${fulldevname} ${white_listed_devices}
 408                 then
 409                         # skip this device entirely
 410                         continue
 411                 fi
 412
 413                 for dev in $(subdevices "${sysblock}")
 414                 do
 415                         devname=$(sys2dev "${dev}")
 416
 417                         if is_in_space_sep_list ${devname} ${black_listed_devices}
 418                         then
 419                                 # skip this subdevice
 420                                 continue
 421                         else
 422                                 echo "${devname}"
 423                         fi
 424                 done
 425         done
 426 }
 427
 428 is_supported_fs ()
 429 {
 430         fstype="${1}"
 431
 432         # Validate input first
 433         if [ -z "${fstype}" ]
 434         then
 435                 return 1
 436         fi
 437
 438         # Try to look if it is already supported by the kernel
 439         if grep -q ${fstype} /proc/filesystems
 440         then
 441                 return 0
 442         else
 443                 # Then try to add support for it the gentle way using the initramfs capabilities
 444                 modprobe ${fstype}
 445                 if grep -q ${fstype} /proc/filesystems
 446                 then
 447                         return 0
 448                 # Then try the hard way if /root is already reachable
 449                 else
 450                         kmodule="/root/lib/modules/`uname -r`/${fstype}/${fstype}.ko"
 451                         if [ -e "${kmodule}" ]
 452                         then
 453                                 insmod "${kmodule}"
 454                                 if grep -q ${fstype} /proc/filesystems
 455                                 then
 456                                         return 0
 457                                 fi
 458                         fi
 459                 fi
 460         fi
 461
 462         return 1
 463 }
 464
 465 get_fstype ()
 466 {
 467         /sbin/blkid -s TYPE -o value $1 2>/dev/null
 468 }
 469
 470 where_is_mounted ()
 471 {
 472         device=${1}
 473         # return first found
 474         grep -m1 "^${device} " /proc/mounts | cut -f2 -d ' '
 475 }
 476
 477 trim_path ()
 478 {
 479         # remove all unnecessary /:s in the path, including last one (except
 480         # if path is just "/")
 481         echo ${1} | sed 's|//\+|/|g' | sed 's|^\(.*[^/]\)/$|\1|'
 482 }
 483
 484 what_is_mounted_on ()
 485 {
 486         local dir
 487         dir="$(trim_path ${1})"
 488         grep -m1 "^[^ ]\+ ${dir} " /proc/mounts | cut -d' ' -f1
 489 }
 490
 491 chown_ref ()
 492 {
 493         local reference targets owner
 494         reference="${1}"
 495         shift
 496         targets=${@}
 497         owner=$(stat -c %u:%g "${reference}")
 498         chown -h ${owner} ${targets}
 499 }
 500
 501 chmod_ref ()
 502 {
 503         local reference targets rights
 504         reference="${1}"
 505         shift
 506         targets=${@}
 507         rights=$(stat -c %a "${reference}")
 508         chmod ${rights} ${targets}
 509 }
 510
 511 lastline ()
 512 {
 513         while read lines
 514         do
 515                 line=${lines}
 516         done
 517
 518         echo "${line}"
 519 }
 520
 521 base_path ()
 522 {
 523         testpath="${1}"
 524         mounts="$(awk '{print $2}' /proc/mounts)"
 525         testpath="$(busybox realpath ${testpath})"
 526
 527         while true
 528         do
 529                 if echo "${mounts}" | grep -qs "^${testpath}"
 530                 then
 531                         set -- $(echo "${mounts}" | grep "^${testpath}" | lastline)
 532                         echo ${1}
 533                         break
 534                 else
 535                         testpath=$(dirname $testpath)
 536                 fi
 537         done
 538 }
 539
 540 fs_size ()
 541 {
 542         # Returns used/free fs kbytes + 5% more
 543         # You could pass a block device as ${1} or the mount point as ${2}
 544
 545         dev="${1}"
 546         mountp="${2}"
 547         used="${3}"
 548
 549         if [ -z "${mountp}" ]
 550         then
 551                 mountp="$(where_is_mounted ${dev})"
 552
 553                 if [ -z "${mountp}" ]
 554                 then
 555                         mountp="/mnt/tmp_fs_size"
 556
 557                         mkdir -p "${mountp}"
 558                         mount -t $(get_fstype "${dev}") -o ro "${dev}" "${mountp}" || log_warning_msg "cannot mount -t $(get_fstype ${dev}) -o ro ${dev} ${mountp}"
 559
 560                         doumount=1
 561                 fi
 562         fi
 563
 564         if [ "${used}" = "used" ]
 565         then
 566                 size=$(du -ks ${mountp} | cut -f1)
 567                 size=$(expr ${size} + ${size} / 20 ) # FIXME: 5% more to be sure
 568         else
 569                 # free space
 570                 size="$(df -kP | grep -s ${mountp} | awk '{print $4}')"
 571         fi
 572
 573         if [ -n "${doumount}" ]
 574         then
 575                 umount "${mountp}" || log_warning_msg "cannot umount ${mountp}"
 576                 rmdir "${mountp}"
 577         fi
 578
 579         echo "${size}"
 580 }
 581
 582 load_keymap ()
 583 {
 584         # Load custom keymap
 585         if [ -x /bin/loadkeys -a -r /etc/boottime.kmap.gz ]
 586         then
 587                 loadkeys --quiet /etc/boottime.kmap.gz
 588         fi
 589 }
 590
 591 setup_loop ()
 592 {
 593         local fspath module pattern offset encryption readonly
 594         fspath=${1}
 595         module=${2}
 596         pattern=${3}
 597         offset=${4}
 598         encryption=${5}
 599         readonly=${6}
 600
 601         # the output of setup_loop is evaluated in other functions,
 602         # modprobe leaks kernel options like "libata.dma=0"
 603         # as "options libata dma=0" on stdout, causing serious
 604         # problems therefor, so instead always avoid output to stdout
 605         modprobe -q -b "${module}" 1>/dev/null
 606
 607         udevadm settle
 608
 609         for loopdev in ${pattern}
 610         do
 611                 if [ "$(cat ${loopdev}/size)" -eq 0 ]
 612                 then
 613                         dev=$(sys2dev "${loopdev}")
 614                         options=''
 615
 616                         if [ -n "${readonly}" ]
 617                         then
 618                                 if losetup --help 2>&1 | grep -q -- "-r\b"
 619                                 then
 620                                         options="${options} -r"
 621                                 fi
 622                         fi
 623
 624                         if [ -n "${offset}" ] && [ 0 -lt "${offset}" ]
 625                         then
 626                                 options="${options} -o ${offset}"
 627                         fi
 628
 629                         if [ -z "${encryption}" ]
 630                         then
 631                                 losetup ${options} "${dev}" "${fspath}"
 632                         else
 633                                 # Loop AES encryption
 634                                 while true
 635                                 do
 636                                         load_keymap
 637
 638                                         echo -n "Enter passphrase for root filesystem: " >&6
 639                                         read -s passphrase
 640                                         echo "${passphrase}" > /tmp/passphrase
 641                                         unset passphrase
 642                                         exec 9</tmp/passphrase
 643                                         /sbin/losetup ${options} -e "${encryption}" -p 9 "${dev}" "${fspath}"
 644                                         error=${?}
 645                                         exec 9<&-
 646                                         rm -f /tmp/passphrase
 647
 648                                         if [ 0 -eq ${error} ]
 649                                         then
 650                                                 unset error
 651                                                 break
 652                                         fi
 653
 654                                         echo
 655                                         echo -n "There was an error decrypting the root filesystem ... Retry? [Y/n] " >&6
 656                                         read answer
 657
 658                                         if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
 659                                         then
 660                                                 unset answer
 661                                                 break
 662                                         fi
 663                                 done
 664                         fi
 665
 666                         echo "${dev}"
 667                         return 0
 668                 fi
 669         done
 670
 671         panic "No loop devices available"
 672 }
 673
 674 try_mount ()
 675 {
 676         dev="${1}"
 677         mountp="${2}"
 678         opts="${3}"
 679         fstype="${4}"
 680
 681         old_mountp="$(where_is_mounted ${dev})"
 682
 683         if [ -n "${old_mountp}" ]
 684         then
 685                 if [ "${opts}" != "ro" ]
 686                 then
 687                         mount -o remount,"${opts}" "${dev}" "${old_mountp}" || panic "Remounting ${dev} ${opts} on ${old_mountp} failed"
 688                 fi
 689
 690                 mount -o bind "${old_mountp}" "${mountp}" || panic "Cannot bind-mount ${old_mountp} on ${mountp}"
 691         else
 692                 if [ -z "${fstype}" ]
 693                 then
 694                         fstype=$(get_fstype "${dev}")
 695                 fi
 696                 mount -t "${fstype}" -o "${opts}" "${dev}" "${mountp}" || \
 697                 ( echo "SKIPPING: Cannot mount ${dev} on ${mountp}, fstype=${fstype}, options=${opts}" > boot.log && return 0 )
 698         fi
 699 }
 700
 701 # Try to mount $device to the place expected by live-boot. If $device
 702 # is already mounted somewhere, move it to the expected place. If
 703 # we're only probing $device (to check if it has custom persistence)
 704 # $probe should be set, which suppresses warnings upon failure. On
 705 # success, print the mount point for $device.
 706 mount_persistence_media ()
 707 {
 708         local device probe backing old_backing fstype mount_opts
 709         device=${1}
 710         probe=${2}
 711
 712         backing="/live/persistence/$(basename ${device})"
 713
 714         mkdir -p "${backing}"
 715         old_backing="$(where_is_mounted ${device})"
 716         if [ -z "${old_backing}" ]
 717         then
 718                 fstype="$(get_fstype ${device})"
 719                 mount_opts="rw,noatime"
 720                 if [ -n "${PERSISTENCE_READONLY}" ]
 721                 then
 722                         mount_opts="ro,noatime"
 723                 fi
 724                 if mount -t "${fstype}" -o "${mount_opts}" "${device}" "${backing}" >/dev/null
 725                 then
 726                         echo ${backing}
 727                         return 0
 728                 else
 729                         [ -z "${probe}" ] && log_warning_msg "Failed to mount persistence media ${device}"
 730                         rmdir "${backing}"
 731                         return 1
 732                 fi
 733         elif [ "${backing}" != "${old_backing}" ]
 734         then
 735                 if mount --move ${old_backing} ${backing} >/dev/null
 736                 then
 737                         echo ${backing}
 738                         return 0
 739                 else
 740                         [ -z "${probe}" ] && log_warning_msg "Failed to move persistence media ${device}"
 741                         rmdir "${backing}"
 742                         return 1
 743                 fi
 744         else
 745                 # This means that $device has already been mounted on
 746                 # the place expected by live-boot, so we're done.
 747                 echo ${backing}
 748                 return 0
 749         fi
 750 }
 751
 752 close_persistence_media ()
 753 {
 754         local device backing
 755         device=${1}
 756         backing="$(where_is_mounted ${device})"
 757
 758         if [ -d "${backing}" ]
 759         then
 760                 umount "${backing}" >/dev/null 2>&1
 761                 rmdir "${backing}" >/dev/null 2>&1
 762         fi
 763
 764         if is_active_luks_mapping ${device}
 765         then
 766                 /sbin/cryptsetup luksClose ${device}
 767         fi
 768 }
 769
 770 open_luks_device ()
 771 {
 772         dev="${1}"
 773         name="$(basename ${dev})"
 774         opts="--key-file=-"
 775         if [ -n "${PERSISTENCE_READONLY}" ]
 776         then
 777                 opts="${opts} --readonly"
 778         fi
 779
 780         if /sbin/cryptsetup status "${name}" >/dev/null 2>&1
 781         then
 782                 re="^[[:space:]]*device:[[:space:]]*\([^[:space:]]*\)$"
 783                 opened_dev=$(cryptsetup status ${name} 2>/dev/null | grep "${re}" | sed "s|${re}|\1|")
 784                 if [ "${opened_dev}" = "${dev}" ]
 785                 then
 786                         luks_device="/dev/mapper/${name}"
 787                         echo ${luks_device}
 788                         return 0
 789                 else
 790                         log_warning_msg "Cannot open luks device ${dev} since ${opened_dev} already is opened with its name"
 791                         return 1
 792                 fi
 793         fi
 794
 795         load_keymap
 796
 797         while true
 798         do
 799                 /lib/cryptsetup/askpass "Enter passphrase for ${dev}: " | \
 800                         /sbin/cryptsetup -T 1 luksOpen ${dev} ${name} ${opts}
 801
 802                 if [ 0 -eq ${?} ]
 803                 then
 804                         luks_device="/dev/mapper/${name}"
 805                         echo ${luks_device}
 806                         return 0
 807                 fi
 808
 809                 echo >&6
 810                 echo -n "There was an error decrypting ${dev} ... Retry? [Y/n] " >&6
 811                 read answer
 812
 813                 if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
 814                 then
 815                         return 2
 816                 fi
 817         done
 818 }
 819
 820 get_gpt_name ()
 821 {
 822     local dev
 823     dev="${1}"
 824     /sbin/blkid -s PART_ENTRY_NAME -p -o value ${dev} 2>/dev/null
 825 }
 826
 827 is_gpt_device ()
 828 {
 829     local dev
 830     dev="${1}"
 831     [ "$(/sbin/blkid -s PART_ENTRY_SCHEME -p -o value ${dev} 2>/dev/null)" = "gpt" ]
 832 }
 833
 834 probe_for_gpt_name ()
 835 {
 836         local overlays dev gpt_dev gpt_name
 837         overlays="${1}"
 838         dev="${2}"
 839
 840         gpt_dev="${dev}"
 841         if is_active_luks_mapping ${dev}
 842         then
 843                 # if $dev is an opened luks device, we need to check
 844                 # GPT stuff on the backing device
 845                 gpt_dev=$(get_luks_backing_device "${dev}")
 846         fi
 847
 848         if ! is_gpt_device ${gpt_dev}
 849         then
 850                 return
 851         fi
 852
 853         gpt_name=$(get_gpt_name ${gpt_dev})
 854         for label in ${overlays}
 855         do
 856                 if [ "${gpt_name}" = "${label}" ]
 857                 then
 858                         echo "${label}=${dev}"
 859                 fi
 860         done
 861 }
 862
 863 probe_for_fs_label ()
 864 {
 865         local overlays dev
 866         overlays="${1}"
 867         dev="${2}"
 868
 869         for label in ${overlays}
 870         do
 871                 if [ "$(/sbin/blkid -s LABEL -o value $dev 2>/dev/null)" = "${label}" ]
 872                 then
 873                         echo "${label}=${dev}"
 874                 fi
 875         done
 876 }
 877
 878 probe_for_file_name ()
 879 {
 880         local overlays dev ret backing
 881         overlays="${1}"
 882         dev="${2}"
 883
 884         ret=""
 885         backing="$(mount_persistence_media ${dev} probe)"
 886         if [ -z "${backing}" ]
 887         then
 888             return
 889         fi
 890
 891         for label in ${overlays}
 892         do
 893                 path=${backing}/${PERSISTENCE_PATH}${label}
 894                 if [ -f "${path}" ]
 895                 then
 896                         local loopdev
 897                         loopdev=$(setup_loop "${path}" "loop" "/sys/block/loop*")
 898                         ret="${ret} ${label}=${loopdev}"
 899                 fi
 900         done
 901
 902         if [ -n "${ret}" ]
 903         then
 904                 echo ${ret}
 905         else
 906                 # unmount and remove mountpoint
 907                 umount ${backing} > /dev/null 2>&1 || true
 908                 rmdir ${backing} > /dev/null 2>&1 || true
 909         fi
 910 }
 911
 912 find_persistence_media ()
 913 {
 914         # Scans devices for overlays, and returns a whitespace
 915         # separated list of how to use them. Only overlays with a partition
 916         # label or file name in ${overlays} are returned.
 917         #
 918         # When scanning a LUKS device, the user will be asked to enter the
 919         # passphrase; on failure to enter it, or if no persistence partitions
 920         # or files were found, the LUKS device is closed.
 921         #
 922         # For all other cases (overlay partition and overlay file) the
 923         # return value is "${label}=${device}", where ${device} a device that
 924         # can mount the content. In the case of an overlay file, the device
 925         # containing the file will remain mounted as a side-effect.
 926         #
 927         # No devices in ${black_listed_devices} will be scanned, and if
 928         # ${white_list_devices} is non-empty, only devices in it will be
 929         # scanned.
 930
 931         local overlays white_listed_devices ret black_listed_devices
 932         overlays="${1}"
 933         white_listed_devices="${2}"
 934         ret=""
 935
 936         black_listed_devices="$(what_is_mounted_on /live/medium) $(what_is_mounted_on /live/findiso) $(what_is_mounted_on /live/fromiso)"
 937
 938         for dev in $(storage_devices "${black_listed_devices}" "${white_listed_devices}")
 939         do
 940                 local result luks_device
 941                 result=""
 942
 943                 luks_device=""
 944                 # Check if it's a luks device; we'll have to open the device
 945                 # in order to probe any filesystem it contains, like we do
 946                 # below. activate_custom_mounts() also depends on that any luks
 947                 # device already has been opened.
 948                 if is_in_comma_sep_list luks ${PERSISTENCE_ENCRYPTION} && is_luks_partition ${dev}
 949                 then
 950                         if luks_device=$(open_luks_device "${dev}")
 951                         then
 952                                 dev="${luks_device}"
 953                         else
 954                                 # skip $dev since we failed/chose not to open it
 955                                 continue
 956                         fi
 957                 elif ! is_in_comma_sep_list none ${PERSISTENCE_ENCRYPTION}
 958                 then
 959                         # skip $dev since we don't allow unencrypted storage
 960                         continue
 961                 fi
 962
 963                 # Probe for matching GPT partition names or filesystem labels
 964                 if is_in_comma_sep_list filesystem ${PERSISTENCE_STORAGE}
 965                 then
 966                         result=$(probe_for_gpt_name "${overlays}" ${dev})
 967                         if [ -n "${result}" ]
 968                         then
 969                                 ret="${ret} ${result}"
 970                                 continue
 971                         fi
 972
 973                         result=$(probe_for_fs_label "${overlays}" ${dev})
 974                         if [ -n "${result}" ]
 975                         then
 976                                 ret="${ret} ${result}"
 977                                 continue
 978                         fi
 979                 fi
 980
 981                 # Probe for files with matching name on mounted partition
 982                 if is_in_comma_sep_list file ${PERSISTENCE_STORAGE}
 983                 then
 984                         result=$(probe_for_file_name "${overlays}" ${dev})
 985                         if [ -n "${result}" ]
 986                         then
 987                                 local loopdevice
 988                                 loopdevice=${result##*=}
 989                                 if is_in_comma_sep_list luks ${PERSISTENCE_ENCRYPTION} && is_luks_partition ${loopdevice}
 990                                 then
 991                                         local luksfile
 992                                         luksfile=""
 993                                         if luksfile=$(open_luks_device "${loopdevice}")
 994                                         then
 995                                                 result=${result%%=*}
 996                                                 result="${result}=${luksfile}"
 997                                         else
 998                                                 losetup -d $loopdevice
 999                                                 result=""
1000                                         fi
1001                                 fi
1002                                 ret="${ret} ${result}"
1003                                 continue
1004                         fi
1005                 fi
1006
1007                 # Close luks device if it isn't used
1008                 if [ -z "${result}" ] && [ -n "${luks_device}" ] && is_active_luks_mapping "${luks_device}"
1009                 then
1010                         /sbin/cryptsetup luksClose "${luks_device}"
1011                 fi
1012         done
1013
1014         if [ -n "${ret}" ]
1015         then
1016                 echo ${ret}
1017         fi
1018 }
1019
1020 get_mac ()
1021 {
1022         mac=""
1023
1024         for adaptor in /sys/class/net/*
1025         do
1026                 status="$(cat ${adaptor}/iflink)"
1027
1028                 if [ "${status}" -eq 2 ]
1029                 then
1030                         mac="$(cat ${adaptor}/address)"
1031                         mac="$(echo ${mac} | sed 's/:/-/g' | tr '[a-z]' '[A-Z]')"
1032                 fi
1033         done
1034
1035         echo ${mac}
1036 }
1037
1038 is_luks_partition ()
1039 {
1040         device="${1}"
1041         /sbin/cryptsetup isLuks "${device}" 1>/dev/null 2>&1
1042 }
1043
1044 is_active_luks_mapping ()
1045 {
1046         device="${1}"
1047         /sbin/cryptsetup status "${device}" 1>/dev/null 2>&1
1048 }
1049
1050 get_luks_backing_device ()
1051 {
1052         device=${1}
1053         cryptsetup status ${device} 2> /dev/null | \
1054                 awk '{if ($1 == "device:") print $2}'
1055 }
1056
1057 removable_dev ()
1058 {
1059         output_format="${1}"
1060         want_usb="${2}"
1061         ret=
1062
1063         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "/(loop|ram|dm-|fd)")
1064         do
1065                 dev_ok=
1066                 if [ "$(cat ${sysblock}/removable)" = "1" ]
1067                 then
1068                         if [ -z "${want_usb}" ]
1069                         then
1070                                 dev_ok="true"
1071                         else
1072                                 if readlink ${sysblock} | grep -q usb
1073                                 then
1074                                         dev_ok="true"
1075                                 fi
1076                         fi
1077                 fi
1078
1079                 if [ "${dev_ok}" = "true" ]
1080                 then
1081                         case "${output_format}" in
1082                                 sys)
1083                                         ret="${ret} ${sysblock}"
1084                                         ;;
1085                                 *)
1086                                         devname=$(sys2dev "${sysblock}")
1087                                         ret="${ret} ${devname}"
1088                                         ;;
1089                         esac
1090                 fi
1091         done
1092
1093         echo "${ret}"
1094 }
1095
1096 removable_usb_dev ()
1097 {
1098         output_format="${1}"
1099
1100         removable_dev "${output_format}" "want_usb"
1101 }
1102
1103 non_removable_dev ()
1104 {
1105         output_format="${1}"
1106         ret=
1107
1108         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "/(loop|ram|dm-|fd)")
1109         do
1110                 if [ "$(cat ${sysblock}/removable)" = "0" ]
1111                 then
1112                         case "${output_format}" in
1113                                 sys)
1114                                         ret="${ret} ${sysblock}"
1115                                         ;;
1116                                 *)
1117                                         devname=$(sys2dev "${sysblock}")
1118                                         ret="${ret} ${devname}"
1119                                         ;;
1120                         esac
1121                 fi
1122         done
1123
1124         echo "${ret}"
1125 }
1126
1127 link_files ()
1128 {
1129         # create source's directory structure in dest, and recursively
1130         # create symlinks in dest to to all files in source. if mask
1131         # is non-empty, remove mask from all source paths when
1132         # creating links (will be necessary if we change root, which
1133         # live-boot normally does (into $rootmnt)).
1134         local src_dir dest_dir src_transform
1135
1136         # remove multiple /:s and ensure ending on /
1137         src_dir="$(trim_path ${1})/"
1138         dest_dir="$(trim_path ${2})/"
1139         src_transform="${3}"
1140
1141         # This check can only trigger on the inital, non-recursive call since
1142         # we create the destination before recursive calls
1143         if [ ! -d "${dest_dir}" ]
1144         then
1145                 log_warning_msg "Must link_files into a directory"
1146                 return
1147         fi
1148
1149         find "${src_dir}" -mindepth 1 -maxdepth 1 | \
1150         while read src
1151         do
1152                 local dest final_src
1153                 dest="${dest_dir}$(basename "${src}")"
1154                 if [ -d "${src}" ]
1155                 then
1156                         if [ -z "$(ls -A "${src}")" ]
1157                         then
1158                                 continue
1159                         fi
1160                         if [ ! -d "${dest}" ]
1161                         then
1162                                 mkdir -p "${dest}"
1163                                 chown_ref "${src}" "${dest}"
1164                                 chmod_ref "${src}" "${dest}"
1165                         fi
1166                         link_files "${src}" "${dest}" "${src_transform}"
1167                 else
1168                         final_src=${src}
1169                         if [ -n "${src_transform}" ]
1170                         then
1171                                 final_src="$(echo ${final_src} | sed "${src_transform}")"
1172                         fi
1173                         rm -rf "${dest}" 2> /dev/null
1174                         ln -s "${final_src}" "${dest}"
1175                         chown_ref "${src}" "${dest}"
1176                 fi
1177         done
1178 }
1179
1180 do_union ()
1181 {
1182         local unionmountpoint unionrw unionro
1183         unionmountpoint="${1}"  # directory where the union is mounted
1184         shift
1185         unionrw="${1}"          # branch where the union changes are stored
1186         shift
1187         unionro="${*}"          # space separated list of read-only branches (optional)
1188
1189         case "${UNIONTYPE}" in
1190                 aufs)
1191                         rw_opt="rw"
1192                         ro_opt="rr+wh"
1193                         noxino_opt="noxino"
1194                         ;;
1195
1196                 unionfs-fuse)
1197                         rw_opt="RW"
1198                         ro_opt="RO"
1199                         ;;
1200
1201                 *)
1202                         rw_opt="rw"
1203                         ro_opt="ro"
1204                         ;;
1205         esac
1206
1207         case "${UNIONTYPE}" in
1208                 unionfs-fuse)
1209                         unionmountopts="-o cow -o noinitgroups -o default_permissions -o allow_other -o use_ino -o suid"
1210                         unionmountopts="${unionmountopts} ${unionrw}=${rw_opt}"
1211                         if [ -n "${unionro}" ]
1212                         then
1213                                 for rofs in ${unionro}
1214                                 do
1215                                         unionmountopts="${unionmountopts}:${rofs}=${ro_opt}"
1216                                 done
1217                         fi
1218                         ( sysctl -w fs.file-max=391524 ; ulimit -HSn 16384
1219                         unionfs-fuse ${unionmountopts} "${unionmountpoint}" ) && \
1220                         ( mkdir -p /run/sendsigs.omit.d
1221                         pidof unionfs-fuse >> /run/sendsigs.omit.d/unionfs-fuse || true )
1222                         ;;
1223
1224                 overlayfs)
1225                         # XXX: can multiple unionro be used? (overlayfs only handles two dirs, but perhaps they can be chained?)
1226                         # XXX: and can unionro be optional? i.e. can overlayfs skip lowerdir?
1227                         if echo ${unionro} | grep -q " "
1228                         then
1229                                 panic "Multiple lower filesystems are currently not supported with overlayfs (unionro = ${unionro})."
1230                         elif [ -z "${unionro}"  ]
1231                         then
1232                                 panic "Overlayfs needs at least one lower filesystem (read-only branch)."
1233                         fi
1234                         unionmountopts="-o noatime,lowerdir=${unionro},upperdir=${unionrw}"
1235                         mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
1236                         ;;
1237
1238                 *)
1239                         unionmountopts="-o noatime,${noxino_opt},dirs=${unionrw}=${rw_opt}"
1240                         if [ -n "${unionro}" ]
1241                         then
1242                                 for rofs in ${unionro}
1243                                 do
1244                                         unionmountopts="${unionmountopts}:${rofs}=${ro_opt}"
1245                                 done
1246                         fi
1247                         mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
1248                         ;;
1249         esac
1250 }
1251
1252 get_custom_mounts ()
1253 {
1254         # Side-effect: leaves $devices with persistence.conf mounted in /live/persistence
1255         # Side-effect: prints info to file $custom_mounts
1256
1257         local custom_mounts devices bindings links
1258         custom_mounts=${1}
1259         shift
1260         devices=${@}
1261
1262         bindings="/tmp/bindings.list"
1263         links="/tmp/links.list"
1264         rm -rf ${bindings} ${links} 2> /dev/null
1265
1266         for device in ${devices}
1267         do
1268                 if [ ! -b "${device}" ]
1269                 then
1270                         continue
1271                 fi
1272
1273                 local device_name backing include_list
1274                 device_name="$(basename ${device})"
1275                 backing=$(mount_persistence_media ${device})
1276                 if [ -z "${backing}" ]
1277                 then
1278                         continue
1279                 fi
1280
1281                 if [ -r "${backing}/${persistence_list}" ]
1282                 then
1283                         include_list="${backing}/${persistence_list}"
1284                 else
1285                         continue
1286                 fi
1287
1288                 if [ -n "${LIVE_BOOT_DEBUG}" ] && [ -e "${include_list}" ]
1289                 then
1290                         cp ${include_list} /live/persistence/${persistence_list}.${device_name}
1291                 fi
1292
1293                 while read dir options # < ${include_list}
1294                 do
1295                         if echo ${dir} | grep -qe "^[[:space:]]*\(#.*\)\?$"
1296                         then
1297                                 # skipping empty or commented lines
1298                                 continue
1299                         fi
1300
1301                         if trim_path ${dir} | grep -q -e "^[^/]" -e "^/lib" -e "^/lib/live\(/.*\)\?$" -e "^/\(.*/\)\?\.\.\?\(/.*\)\?$"
1302                         then
1303                                 log_warning_msg "Skipping unsafe custom mount ${dir}: must be an absolute path containing neither the \".\" nor \"..\" special dirs, and cannot be \"/lib\", or \"/lib/live\" or any of its sub-directories."
1304                                 continue
1305                         fi
1306
1307                         local opt_source opt_link source full_source full_dest
1308                         opt_source=""
1309                         opt_link=""
1310                         for opt in $(echo ${options} | tr ',' ' ');
1311                         do
1312                                 case "${opt}" in
1313                                         source=*)
1314                                                 opt_source=${opt#source=}
1315                                                 ;;
1316                                         link)
1317                                                 opt_link="true"
1318                                                 ;;
1319                                         union|bind)
1320                                                 ;;
1321                                         *)
1322                                                 log_warning_msg "Skipping custom mount with unkown option: ${opt}"
1323                                                 continue 2
1324                                                 ;;
1325                                 esac
1326                         done
1327
1328                         source="${dir}"
1329                         if [ -n "${opt_source}" ]
1330                         then
1331                                 if echo ${opt_source} | grep -q -e "^/" -e "^\(.*/\)\?\.\.\?\(/.*\)\?$" && [ "${opt_source}" != "." ]
1332                                 then
1333                                         log_warning_msg "Skipping unsafe custom mount with option source=${opt_source}: must be either \".\" (the media root) or a relative path w.r.t. the media root that contains neither comas, nor the special \".\" and \"..\" path components"
1334                                         continue
1335                                 else
1336                                         source="${opt_source}"
1337                                 fi
1338                         fi
1339
1340                         full_source="$(trim_path ${backing}/${source})"
1341                         full_dest="$(trim_path ${rootmnt}/${dir})"
1342                         if [ -n "${opt_link}" ]
1343                         then
1344                                 echo "${device} ${full_source} ${full_dest} ${options}" >> ${links}
1345                         else
1346                                 echo "${device} ${full_source} ${full_dest} ${options}" >> ${bindings}
1347                         fi
1348                 done < ${include_list}
1349         done
1350
1351         # We sort the list according to destination so we're sure that
1352         # we won't hide a previous mount. We also ignore duplicate
1353         # destinations in a more or less arbitrary way.
1354         [ -e "${bindings}" ] && sort -k3 -sbu ${bindings} >> ${custom_mounts} && rm ${bindings}
1355
1356         # After all mounts are considered we add symlinks so they
1357         # won't be hidden by some mount.
1358         [ -e "${links}" ] && cat ${links} >> ${custom_mounts} && rm ${links}
1359
1360         # We need to make sure that no two custom mounts have the same sources
1361         # or are nested; if that is the case, too much weird stuff can happen.
1362         local prev_source prev_dest
1363         prev_source="impossible source" # first iteration must not match
1364         prev_dest=""
1365         # This sort will ensure that a source /a comes right before a source
1366         # /a/b so we only need to look at the previous source
1367         sort -k2 -b ${custom_mounts} |
1368         while read device source dest options
1369         do
1370                 if echo ${source} | grep -qe "^${prev_source}\(/.*\)\?$"
1371                 then
1372                         panic "Two persistence mounts have the same or nested sources: ${source} on ${dest}, and ${prev_source} on ${prev_dest}"
1373                 fi
1374                 prev_source=${source}
1375                 prev_dest=${dest}
1376         done
1377 }
1378
1379 activate_custom_mounts ()
1380 {
1381         local custom_mounts used_devices
1382         custom_mounts="${1}" # the ouput from get_custom_mounts()
1383         used_devices=""
1384
1385         while read device source dest options # < ${custom_mounts}
1386         do
1387                 local opt_bind opt_link opt_union
1388                 opt_bind="true"
1389                 opt_link=""
1390                 opt_union=""
1391                 for opt in $(echo ${options} | tr ',' ' ');
1392                 do
1393                         case "${opt}" in
1394                                 bind)
1395                                         opt_bind="true"
1396                                         unset opt_link opt_union
1397                                         ;;
1398                                 link)
1399                                         opt_link="true"
1400                                         unset opt_bind opt_union
1401                                         ;;
1402                                 union)
1403                                         opt_union="true"
1404                                         unset opt_bind opt_link
1405                                         ;;
1406                         esac
1407                 done
1408
1409                 if [ -n "$(what_is_mounted_on "${dest}")" ]
1410                 then
1411                         if [ "${dest}" = "${rootmnt}" ]
1412                         then
1413                                 umount "${dest}"
1414                         else
1415                                 log_warning_msg "Skipping custom mount ${dest}: $(what_is_mounted_on "${dest}") is already mounted there"
1416                                 continue
1417                         fi
1418                 fi
1419
1420                 if [ ! -d "${dest}" ]
1421                 then
1422                         # create the destination and delete existing files in
1423                         # its path that are in the way
1424                         path="/"
1425                         for dir in $(echo ${dest} | sed -e 's|/\+| |g')
1426                         do
1427                                 path=$(trim_path ${path}/${dir})
1428                                 if [ -f ${path} ]
1429                                 then
1430                                         rm -f ${path}
1431                                 fi
1432                                 if [ ! -e ${path} ]
1433                                 then
1434                                         mkdir -p ${path}
1435                                         if echo ${path} | grep -qe "^${rootmnt}/*home/[^/]\+"
1436                                         then
1437                                                 # if ${dest} is in /home try fixing proper ownership by assuming that the intended user is the first, which is usually the case
1438                                                 # FIXME: this should really be handled by live-config since we don't know for sure which uid a certain user has until then
1439                                                 chown 1000:1000 ${path}
1440                                         fi
1441                                 fi
1442                         done
1443                 fi
1444
1445                 # if ${source} doesn't exist on our persistence media
1446                 # we bootstrap it with $dest from the live filesystem.
1447                 # this both makes sense and is critical if we're
1448                 # dealing with /etc or other system dir.
1449                 if [ ! -d "${source}" ]
1450                 then
1451                         if [ -n "${PERSISTENCE_READONLY}" ]
1452                         then
1453                                 continue
1454                         elif [ -n "${opt_union}" ] || [ -n "${opt_link}" ]
1455                         then
1456                                 # unions and don't need to be bootstrapped
1457                                 # link dirs can't be bootstrapped in a sensible way
1458                                 mkdir -p "${source}"
1459                                 chown_ref "${dest}" "${source}"
1460                                 chmod_ref "${dest}" "${source}"
1461                         elif [ -n "${opt_bind}" ]
1462                         then
1463                                 # ensure that $dest is not copied *into* $source
1464                                 mkdir -p "$(dirname ${source})"
1465                                 cp -a "${dest}" "${source}"
1466                         fi
1467                 fi
1468
1469                 # XXX: If CONFIG_AUFS_ROBR is added to the Debian kernel we can
1470                 # ignore the loop below and set rootfs_dest_backing=$dest
1471                 local rootfs_dest_backing
1472                 rootfs_dest_backing=""
1473                 if [ -n "${opt_link}" ] || [ -n "${opt_union}" ]
1474                 then
1475                         for d in /live/rootfs/*
1476                         do
1477                                 if [ -n "${rootmnt}" ]
1478                                 then
1479                                         fs="${d}/$(echo ${dest} | sed -e "s|${rootmnt}||")"
1480                                 else
1481                                         fs="${d}/${dest}"
1482                                 fi
1483                                 if [ -d "${fs}" ]
1484                                 then
1485                                         rootfs_dest_backing="${rootfs_dest_backing} ${fs}"
1486                                 fi
1487                         done
1488                 fi
1489
1490                 local cow_dir links_source
1491                 if [ -n "${opt_link}" ] && [ -z "${PERSISTENCE_READONLY}" ]
1492                 then
1493                         link_files ${source} ${dest} "s|^/live/|/lib/live/mount/|"
1494                 elif [ -n "${opt_link}" ] && [ -n "${PERSISTENCE_READONLY}" ]
1495                 then
1496                         mkdir -p ${rootmnt}/lib/live/mount/persistence
1497                         links_source=$(mktemp -d ${rootmnt}/lib/live/mount/persistence/links-source-XXXXXX)
1498                         chown_ref ${source} ${links_source}
1499                         chmod_ref ${source} ${links_source}
1500                         # We put the cow dir in the below strange place to
1501                         # make it absolutely certain that the link source
1502                         # has its own directory and isn't nested with some
1503                         # other custom mount (if so that mount's files would
1504                         # be linked, causing breakage.
1505                         cow_dir="/live/overlay/lib/live/mount/persistence/$(basename ${links_source})"
1506                         mkdir -p ${cow_dir}
1507                         chown_ref "${source}" "${cow_dir}"
1508                         chmod_ref "${source}" "${cow_dir}"
1509                         do_union ${links_source} ${cow_dir} ${source} ${rootfs_dest_backing}
1510                         link_files ${links_source} ${dest} "s|^${rootmnt}||"
1511                 elif [ -n "${opt_union}" ] && [ -z "${PERSISTENCE_READONLY}" ]
1512                 then
1513                         do_union ${dest} ${source} ${rootfs_dest_backing}
1514                 elif [ -n "${opt_bind}" ] && [ -z "${PERSISTENCE_READONLY}" ]
1515                 then
1516                         mount --bind "${source}" "${dest}"
1517                 elif [ -n "${opt_bind}" -o -n "${opt_union}" ] && [ -n "${PERSISTENCE_READONLY}" ]
1518                 then
1519                         # bind-mount and union mount are handled the same
1520                         # in read-only mode, but note that rootfs_dest_backing
1521                         # is non-empty (and necessary) only for unions
1522                         cow_dir="/live/overlay/${dest}"
1523                         if [ -e "${cow_dir}" ] && [ -z "${opt_link}" ]
1524                         then
1525                                 # If an earlier custom mount has files here
1526                                 # it will "block" the current mount's files
1527                                 # which is undesirable
1528                                 rm -rf "${cow_dir}"
1529                         fi
1530                         mkdir -p ${cow_dir}
1531                         chown_ref "${source}" "${cow_dir}"
1532                         chmod_ref "${source}" "${cow_dir}"
1533                         do_union ${dest} ${cow_dir} ${source} ${rootfs_dest_backing}
1534                 fi
1535
1536                 PERSISTENCE_IS_ON="1"
1537                 export PERSISTENCE_IS_ON
1538
1539                 if echo ${used_devices} | grep -qve "^\(.* \)\?${device}\( .*\)\?$"
1540                 then
1541                         used_devices="${used_devices} ${device}"
1542                 fi
1543         done < ${custom_mounts}
1544
1545         echo ${used_devices}
1546 }
1547
1548 is_mountpoint ()
1549 {
1550         directory="$1"
1551
1552         [ $(stat -fc%d:%D "${directory}") != $(stat -fc%d:%D "${directory}/..") ]
1553 }