scripts/live-helpers

   1 # live-boot helper functions, used by live-boot on boot and by live-snapshot
   2
   3 if [ ! -x "/bin/fstype" ]
   4 then
   5         # klibc not in path -> not in initramfs
   6         export PATH="${PATH}:/usr/lib/klibc/bin"
   7 fi
   8
   9 # handle upgrade path from old udev (using udevinfo) to
  10 # recent versions of udev (using udevadm info)
  11 if [ -x /sbin/udevadm ]
  12 then
  13         udevinfo='/sbin/udevadm info'
  14 else
  15         udevinfo='udevinfo'
  16 fi
  17
  18 root_overlay_label="full-ov"
  19 old_root_overlay_label="live-rw"
  20 old_home_overlay_label="home-rw"
  21 custom_overlay_label="custom-ov"
  22 root_snapshot_label="live-sn"
  23 old_root_snapshot_label="live-sn"
  24 home_snapshot_label="home-sn"
  25 persistence_list="live.persist"
  26
  27 Arguments ()
  28 {
  29         PRESEEDS=""
  30         LOCATIONS=""
  31
  32         for ARGUMENT in $(cat /proc/cmdline)
  33         do
  34                 case "${ARGUMENT}" in
  35                         skipconfig)
  36                                 NOACCESSIBILITY="Yes"
  37                                 NOFASTBOOT="Yes"
  38                                 NOFSTAB="Yes"
  39                                 NONETWORKING="Yes"
  40
  41                                 export NOACCESSIBILITY NOFASTBOOT NOFSTAB NONETWORKING
  42                                 ;;
  43
  44                         access=*)
  45                                 ACCESS="${ARGUMENT#access=}"
  46                                 export ACCESS
  47                                 ;;
  48
  49                         console=*)
  50                                 DEFCONSOLE="${ARGUMENT#*=}"
  51                                 export DEFCONSOLE
  52                                 ;;
  53
  54                         BOOTIF=*)
  55                                 BOOTIF="${x#BOOTIF=}"
  56                                 ;;
  57
  58                         debug)
  59                                 DEBUG="Yes"
  60                                 export DEBUG
  61
  62                                 set -x
  63                                 ;;
  64
  65                         dhcp)
  66                                 # Force dhcp even while netbooting
  67                                 # Use for debugging in case somebody works on fixing dhclient
  68                                 DHCP="Force";
  69                                 export DHCP
  70                                 ;;
  71
  72                         nodhcp)
  73                                 unset DHCP
  74                                 ;;
  75
  76                         ethdevice=*)
  77                                 DEVICE="${ARGUMENT#ethdevice=}"
  78                                 ETHDEVICE="${DEVICE}"
  79                                 export DEVICE ETHDEVICE
  80                                 ;;
  81
  82                         ethdevice-timeout=*)
  83                                 ETHDEV_TIMEOUT="${ARGUMENT#ethdevice-timeout=}"
  84                                 export ETHDEV_TIMEOUT
  85                                 ;;
  86
  87                         fetch=*)
  88                                 FETCH="${ARGUMENT#fetch=}"
  89                                 export FETCH
  90                                 ;;
  91
  92                         forcepersistentfsck)
  93                                 FORCEPERSISTENTFSCK="Yes"
  94                                 export FORCEPERSISTENTFSCK
  95                                 ;;
  96
  97                         ftpfs=*)
  98                                 FTPFS="${ARGUMENT#ftpfs=}"
  99                                 export FTPFS
 100                                 ;;
 101
 102                         httpfs=*)
 103                                 HTTPFS="${ARGUMENT#httpfs=}"
 104                                 export HTTPFS
 105                                 ;;
 106
 107                         iscsi=*)
 108                                 ISCSI="${ARGUMENT#iscsi=}"
 109                                 #ip:port - separated by ;
 110                                 ISCSI_PORTAL="${ISCSI%;*}"
 111                                 if echo "${ISCSI_PORTAL}" | grep -q , ; then
 112                                         ISCSI_SERVER="${ISCSI_PORTAL%,*}"
 113                                         ISCSI_PORT="${ISCSI_PORTAL#*,}"
 114                                 fi
 115                                 #target name
 116                                 ISCSI_TARGET="${ISCSI#*;}"
 117                                 export ISCSI ISCSI_PORTAL ISCSI_TARGET ISCSI_SERVER ISCSI_PORT
 118                                 ;;
 119
 120                         isofrom=*|fromiso=*)
 121                                 FROMISO="${ARGUMENT#*=}"
 122                                 export FROMISO
 123                                 ;;
 124
 125                         ignore_uuid)
 126                                 IGNORE_UUID="Yes"
 127                                 export IGNORE_UUID
 128                                 ;;
 129
 130                         integrity-check)
 131                                 INTEGRITY_CHECK="Yes"
 132                                 export INTEGRITY_CHECK
 133                                 ;;
 134
 135                         ip=*)
 136                                 STATICIP="${ARGUMENT#ip=}"
 137
 138                                 if [ -z "${STATICIP}" ]
 139                                 then
 140                                         STATICIP="frommedia"
 141                                 fi
 142
 143                                 export STATICIP
 144                                 ;;
 145
 146                         live-getty)
 147                                 LIVE_GETTY="1"
 148                                 export LIVE_GETTY
 149                                 ;;
 150
 151                         live-media=*|bootfrom=*)
 152                                 LIVE_MEDIA="${ARGUMENT#*=}"
 153                                 export LIVE_MEDIA
 154                                 ;;
 155
 156                         live-media-encryption=*|encryption=*)
 157                                 LIVE_MEDIA_ENCRYPTION="${ARGUMENT#*=}"
 158                                 export LIVE_MEDIA_ENCRYPTION
 159                                 ;;
 160
 161                         live-media-offset=*)
 162                                 LIVE_MEDIA_OFFSET="${ARGUMENT#live-media-offset=}"
 163                                 export LIVE_MEDIA_OFFSET
 164                                 ;;
 165
 166                         live-media-path=*)
 167                                 LIVE_MEDIA_PATH="${ARGUMENT#live-media-path=}"
 168                                 export LIVE_MEDIA_PATH
 169                                 ;;
 170
 171                         live-media-timeout=*)
 172                                 LIVE_MEDIA_TIMEOUT="${ARGUMENT#live-media-timeout=}"
 173                                 export LIVE_MEDIA_TIMEOUT
 174                                 ;;
 175
 176                         module=*)
 177                                 MODULE="${ARGUMENT#module=}"
 178                                 export MODULE
 179                                 ;;
 180
 181                         netboot=*)
 182                                 NETBOOT="${ARGUMENT#netboot=}"
 183                                 export NETBOOT
 184                                 ;;
 185
 186                         nfsopts=*)
 187                                 NFSOPTS="${ARGUMENT#nfsopts=}"
 188                                 export NFSOPTS
 189                                 ;;
 190
 191                         nfscow=*)
 192                                 NFS_COW="${ARGUMENT#nfscow=}"
 193                                 export NFS_COW
 194                                 ;;
 195
 196                         noaccessibility)
 197                                 NOACCESSIBILITY="Yes"
 198                                 export NOACCESSIBILITY
 199                                 ;;
 200
 201                         nofastboot)
 202                                 NOFASTBOOT="Yes"
 203                                 export NOFASTBOOT
 204                                 ;;
 205
 206                         nofstab)
 207                                 NOFSTAB="Yes"
 208                                 export NOFSTAB
 209                                 ;;
 210
 211                         nonetworking)
 212                                 NONETWORKING="Yes"
 213                                 export NONETWORKING
 214                                 ;;
 215
 216                         ramdisk-size=*)
 217                                 ramdisk_size="${ARGUMENT#ramdisk-size=}"
 218                                 ;;
 219
 220                         swapon)
 221                                 SWAPON="Yes"
 222                                 export SWAPON
 223                                 ;;
 224
 225                         persistent)
 226                                 PERSISTENT="Yes"
 227                                 export PERSISTENT
 228                                 ;;
 229
 230                         persistent-encryption=*)
 231                                 PERSISTENT_ENCRYPTION="${ARGUMENT#*=}"
 232                                 export PERSISTENT_ENCRYPTION
 233                                 ;;
 234
 235                         persistent-media=*)
 236                                 PERSISTENT_MEDIA="${ARGUMENT#*=}"
 237                                 export PERSISTENT_MEDIA
 238                                 ;;
 239                         persistent-method=*)
 240                                 PERSISTENT_METHOD="${ARGUMENT#*=}"
 241                                 export PERSISTENT_METHOD
 242                                 ;;
 243
 244                         persistent-path=*)
 245                                 PERSISTENT_PATH="${ARGUMENT#persistent-path=}"
 246                                 export PERSISTENT_PATH
 247                                 ;;
 248                         persistent-read-only)
 249                                 PERSISTENT_READONLY="Yes"
 250                                 export PERSISTENT_READONLY
 251                                 ;;
 252
 253                         persistent-storage=*)
 254                                 PERSISTENT_STORAGE="${ARGUMENT#persistent-storage=}"
 255                                 export PERSISTENT_STORAGE
 256                                 ;;
 257
 258                         persistent-subtext=*)
 259                                 root_overlay_label="${root_overlay_label}-${ARGUMENT#persistent-subtext=}"
 260                                 old_root_overlay_label="${old_root_overlay_label}-${ARGUMENT#persistent-subtext=}"
 261                                 old_home_overlay_label="${old_home_overlay_label}-${ARGUMENT#persistent-subtext=}"
 262                                 custom_overlay_label="${custom_overlay_label}-${ARGUMENT#persistent-subtext=}"
 263                                 root_snapshot_label="${root_snapshot_label}-${ARGUMENT#persistent-subtext=}"
 264                                 old_root_snapshot_label="${root_snapshot_label}-${ARGUMENT#persistent-subtext=}"
 265                                 home_snapshot_label="${home_snapshot_label}-${ARGUMENT#persistent-subtext=}"
 266                                 ;;
 267
 268                         nopersistent)
 269                                 NOPERSISTENT="Yes"
 270                                 export NOPERSISTENT
 271                                 ;;
 272
 273                         noprompt)
 274                                 NOPROMPT="Yes"
 275                                 export NOPROMPT
 276                                 ;;
 277
 278                         noprompt=*)
 279                                 NOPROMPT="${ARGUMENT#noprompt=}"
 280                                 export NOPROMPT
 281                                 ;;
 282
 283                         quickusbmodules)
 284                                 QUICKUSBMODULES="Yes"
 285                                 export QUICKUSBMODULES
 286                                 ;;
 287
 288                         preseed/file=*|file=*)
 289                                 LOCATIONS="${ARGUMENT#*=} ${LOCATIONS}"
 290                                 export LOCATIONS
 291                                 ;;
 292
 293                         nopreseed)
 294                                 NOPRESEED="Yes"
 295                                 export NOPRESEED
 296                                 ;;
 297
 298                         */*=*)
 299                                 question="${ARGUMENT%%=*}"
 300                                 value="${ARGUMENT#*=}"
 301                                 PRESEEDS="${PRESEEDS}\"${question}=${value}\" "
 302                                 export PRESEEDS
 303                                 ;;
 304
 305                         showmounts)
 306                                 SHOWMOUNTS="Yes"
 307                                 export SHOWMOUNTS
 308                                 ;;
 309
 310                         silent)
 311                                 SILENT="Yes"
 312                                 export SILENT
 313                                 ;;
 314
 315                         todisk=*)
 316                                 TODISK="${ARGUMENT#todisk=}"
 317                                 export TODISK
 318                                 ;;
 319
 320                         toram)
 321                                 TORAM="Yes"
 322                                 export TORAM
 323                                 ;;
 324
 325                         toram=*)
 326                                 TORAM="Yes"
 327                                 MODULETORAM="${ARGUMENT#toram=}"
 328                                 export TORAM MODULETORAM
 329                                 ;;
 330
 331                         exposedroot)
 332                                 EXPOSED_ROOT="Yes"
 333                                 export EXPOSED_ROOT
 334                                 ;;
 335
 336                         plainroot)
 337                                 PLAIN_ROOT="Yes"
 338                                 export PLAIN_ROOT
 339                                 ;;
 340
 341                         skipunion)
 342                                 SKIP_UNION_MOUNTS="Yes"
 343                                 export SKIP_UNION_MOUNTS
 344                                 ;;
 345
 346                         root=*)
 347                                 ROOT="${ARGUMENT#root=}"
 348                                 export ROOT
 349                                 ;;
 350
 351                         union=*)
 352                                 UNIONTYPE="${ARGUMENT#union=}"
 353                                 export UNIONTYPE
 354                                 ;;
 355                 esac
 356         done
 357
 358         # sort of compatibility with netboot.h from linux docs
 359         if [ -z "${NETBOOT}" ]
 360         then
 361                 if [ "${ROOT}" = "/dev/nfs" ]
 362                 then
 363                         NETBOOT="nfs"
 364                         export NETBOOT
 365                 elif [ "${ROOT}" = "/dev/cifs" ]
 366                 then
 367                         NETBOOT="cifs"
 368                         export NETBOOT
 369                 fi
 370         fi
 371
 372         if [ -z "${MODULE}" ]
 373         then
 374                 MODULE="filesystem"
 375                 export MODULE
 376         fi
 377
 378         if [ -z "${UNIONTYPE}" ]
 379         then
 380                 UNIONTYPE="aufs"
 381                 export UNIONTYPE
 382         fi
 383
 384         if [ -z "${PERSISTENT_ENCRYPTION}" ]
 385         then
 386                 PERSISTENT_ENCRYPTION="none"
 387                 export PERSISTENT_ENCRYPTION
 388         elif echo ${PERSISTENT_ENCRYPTION} | grep -qe "\<luks\>"
 389         then
 390                 if ! modprobe dm-crypt
 391                 then
 392                         log_warning_msg "Unable to load module dm-crypt"
 393                         PERSISTENT_ENCRYPTION=$(echo ${PERSISTENT_ENCRYPTION} | sed -e 's/\<luks,\|,\?luks$//g')
 394                         export PERSISTENT_ENCRYPTION
 395                 fi
 396
 397                 if [ ! -x /lib/cryptsetup/askpass ] || [ ! -x /sbin/cryptsetup ]
 398                 then
 399                         log_warning_msg "cryptsetup in unavailable"
 400                         PERSISTENT_ENCRYPTION=$(echo ${PERSISTENT_ENCRYPTION} | sed -e 's/\<luks,\|,\?luks$//g')
 401                         export PERSISTENT_ENCRYPTION
 402                 fi
 403         fi
 404
 405         if [ -z "${PERSISTENT_METHOD}" ]
 406         then
 407                 PERSISTENT_METHOD="snapshot,overlay"
 408                 export PERSISTENT_METHOD
 409         fi
 410
 411         if [ -z "${PERSISTENT_STORAGE}" ]
 412         then
 413                 PERSISTENT_STORAGE="filesystem,file"
 414                 export PERSISTENT_STORAGE
 415         fi
 416 }
 417
 418 sys2dev ()
 419 {
 420         sysdev=${1#/sys}
 421         echo "/dev/$($udevinfo -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})"
 422 }
 423
 424 subdevices ()
 425 {
 426         sysblock=${1}
 427         r=""
 428
 429         for dev in "${sysblock}"/* "${sysblock}"
 430         do
 431                 if [ -e "${dev}/dev" ]
 432                 then
 433                         r="${r} ${dev}"
 434                 fi
 435         done
 436
 437         echo ${r}
 438 }
 439
 440 storage_devices()
 441 {
 442         black_listed_devices="${1}"
 443         white_listed_devices="${2}"
 444
 445         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "loop|ram|fd")
 446         do
 447                 fulldevname=$(sys2dev "${sysblock}")
 448
 449                 if echo "${black_listed_devices}" | grep -qe "\<${fulldevname}\>" || \
 450                         [ -n "${white_listed_devices}" ] && \
 451                         echo "${white_listed_devices}" | grep -qve "\<${fulldevname}\>"
 452                 then
 453                         # skip this device entirely
 454                         continue
 455                 fi
 456
 457                 for dev in $(subdevices "${sysblock}")
 458                 do
 459                         devname=$(sys2dev "${dev}")
 460
 461                         if echo "${black_listed_devices}" | grep -qe "\<${devname}\>"
 462                         then
 463                                 # skip this subdevice
 464                                 continue
 465                         else
 466                                 echo "${devname}"
 467                         fi
 468                 done
 469         done
 470 }
 471
 472 is_supported_fs ()
 473 {
 474         fstype="${1}"
 475
 476         # Validate input first
 477         if [ -z "${fstype}" ]
 478         then
 479                 return 1
 480         fi
 481
 482         # Try to look if it is already supported by the kernel
 483         if grep -q ${fstype} /proc/filesystems
 484         then
 485                 return 0
 486         else
 487                 # Then try to add support for it the gentle way using the initramfs capabilities
 488                 modprobe ${fstype}
 489                 if grep -q ${fstype} /proc/filesystems
 490                 then
 491                         return 0
 492                 # Then try the hard way if /root is already reachable
 493                 else
 494                         kmodule="/root/lib/modules/`uname -r`/${fstype}/${fstype}.ko"
 495                         if [ -e "${kmodule}" ]
 496                         then
 497                                 insmod "${kmodule}"
 498                                 if grep -q ${fstype} /proc/filesystems
 499                                 then
 500                                         return 0
 501                                 fi
 502                         fi
 503                 fi
 504         fi
 505
 506         return 1
 507 }
 508
 509 get_fstype ()
 510 {
 511         /sbin/blkid -s TYPE -o value $1 2>/dev/null
 512 }
 513
 514 where_is_mounted ()
 515 {
 516         device=${1}
 517         # return first found
 518         grep -m1 "^${device} " /proc/mounts | cut -f2 -d ' '
 519 }
 520
 521 trim_path () {
 522     # remove all unnecessary /:s in the path, including last
 523     echo ${1} | sed 's|//|/|g' | sed 's|/$||'
 524 }
 525
 526 what_is_mounted_on ()
 527 {
 528         local dir="$(trim_path ${1})"
 529         grep -m1 "^[^ ]\+ ${dir} " /proc/mounts | cut -d' ' -f1
 530 }
 531
 532 lastline ()
 533 {
 534         while read lines
 535         do
 536                 line=${lines}
 537         done
 538
 539         echo "${line}"
 540 }
 541
 542 base_path ()
 543 {
 544         testpath="${1}"
 545         mounts="$(awk '{print $2}' /proc/mounts)"
 546         testpath="$(busybox realpath ${testpath})"
 547
 548         while true
 549         do
 550                 if echo "${mounts}" | grep -qs "^${testpath}"
 551                 then
 552                         set -- $(echo "${mounts}" | grep "^${testpath}" | lastline)
 553                         echo ${1}
 554                         break
 555                 else
 556                         testpath=$(dirname $testpath)
 557                 fi
 558         done
 559 }
 560
 561 fs_size ()
 562 {
 563         # Returns used/free fs kbytes + 5% more
 564         # You could pass a block device as ${1} or the mount point as ${2}
 565
 566         dev="${1}"
 567         mountp="${2}"
 568         used="${3}"
 569
 570         if [ -z "${mountp}" ]
 571         then
 572                 mountp="$(where_is_mounted ${dev})"
 573
 574                 if [ -z "${mountp}" ]
 575                 then
 576                         mountp="/mnt/tmp_fs_size"
 577
 578                         mkdir -p "${mountp}"
 579                         mount -t $(get_fstype "${dev}") -o ro "${dev}" "${mountp}" || log_warning_msg "cannot mount -t $(get_fstype ${dev}) -o ro ${dev} ${mountp}"
 580
 581                         doumount=1
 582                 fi
 583         fi
 584
 585         if [ "${used}" = "used" ]
 586         then
 587                 size=$(du -ks ${mountp} | cut -f1)
 588                 size=$(expr ${size} + ${size} / 20 ) # FIXME: 5% more to be sure
 589         else
 590                 # free space
 591                 size="$(df -k | grep -s ${mountp} | awk '{print $4}')"
 592         fi
 593
 594         if [ -n "${doumount}" ]
 595         then
 596                 umount "${mountp}" || log_warning_msg "cannot umount ${mountp}"
 597                 rmdir "${mountp}"
 598         fi
 599
 600         echo "${size}"
 601 }
 602
 603 load_keymap ()
 604 {
 605         # Load custom keymap
 606         if [ -x /bin/loadkeys -a -r /etc/boottime.kmap.gz ]
 607         then
 608                 loadkeys /etc/boottime.kmap.gz
 609         fi
 610 }
 611
 612 setup_loop ()
 613 {
 614         local fspath=${1}
 615         local module=${2}
 616         local pattern=${3}
 617         local offset=${4}
 618         local encryption=${5}
 619         local readonly=${6}
 620
 621         # the output of setup_loop is evaluated in other functions,
 622         # modprobe leaks kernel options like "libata.dma=0"
 623         # as "options libata dma=0" on stdout, causing serious
 624         # problems therefor, so instead always avoid output to stdout
 625         modprobe -q -b "${module}" 1>/dev/null
 626
 627         udevadm settle
 628
 629         for loopdev in ${pattern}
 630         do
 631                 if [ "$(cat ${loopdev}/size)" -eq 0 ]
 632                 then
 633                         dev=$(sys2dev "${loopdev}")
 634                         options=''
 635
 636                         if [ -n "${readonly}" ]
 637                         then
 638                                 if losetup --help 2>&1 | grep -q -- "-r\b"
 639                                 then
 640                                         options="${options} -r"
 641                                 fi
 642                         fi
 643
 644                         if [ -n "${offset}" ] && [ 0 -lt "${offset}" ]
 645                         then
 646                                 options="${options} -o ${offset}"
 647                         fi
 648
 649                         if [ -z "${encryption}" ]
 650                         then
 651                                 losetup ${options} "${dev}" "${fspath}"
 652                         else
 653                                 # Loop AES encryption
 654                                 while true
 655                                 do
 656                                         load_keymap
 657
 658                                         echo -n "Enter passphrase for root filesystem: " >&6
 659                                         read -s passphrase
 660                                         echo "${passphrase}" > /tmp/passphrase
 661                                         unset passphrase
 662                                         exec 9</tmp/passphrase
 663                                         /sbin/losetup ${options} -e "${encryption}" -p 9 "${dev}" "${fspath}"
 664                                         error=${?}
 665                                         exec 9<&-
 666                                         rm -f /tmp/passphrase
 667
 668                                         if [ 0 -eq ${error} ]
 669                                         then
 670                                                 unset error
 671                                                 break
 672                                         fi
 673
 674                                         echo
 675                                         echo -n "There was an error decrypting the root filesystem ... Retry? [Y/n] " >&6
 676                                         read answer
 677
 678                                         if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
 679                                         then
 680                                                 unset answer
 681                                                 break
 682                                         fi
 683                                 done
 684                         fi
 685
 686                         echo "${dev}"
 687                         return 0
 688                 fi
 689         done
 690
 691         panic "No loop devices available"
 692 }
 693
 694 try_mount ()
 695 {
 696         dev="${1}"
 697         mountp="${2}"
 698         opts="${3}"
 699         fstype="${4}"
 700
 701         old_mountp="$(where_is_mounted ${dev})"
 702
 703         if [ -n "${old_mountp}" ]
 704         then
 705                 if [ "${opts}" != "ro" ]
 706                 then
 707                         mount -o remount,"${opts}" "${dev}" "${old_mountp}" || panic "Remounting ${dev} ${opts} on ${old_mountp} failed"
 708                 fi
 709
 710                 mount -o bind "${old_mountp}" "${mountp}" || panic "Cannot bind-mount ${old_mountp} on ${mountp}"
 711         else
 712                 if [ -z "${fstype}" ]
 713                 then
 714                         fstype=$(get_fstype "${dev}")
 715                 fi
 716                 mount -t "${fstype}" -o "${opts}" "${dev}" "${mountp}" || \
 717                 ( echo "SKIPPING: Cannot mount ${dev} on ${mountp}, fstype=${fstype}, options=${opts}" > live-boot.log && return 0 )
 718         fi
 719 }
 720
 721 mount_persistent_media ()
 722 {
 723         local device=${1}
 724         local backing=""
 725
 726         # We can't mount into ${rootmnt}/live before ${rootmnt} has been
 727         # mounted since that would cover our mountpoint.
 728         if [ -n "${rootmnt}" ] && [ -z "$(what_is_mounted_on ${rootmnt})" ]
 729         then
 730                 backing="/$(basename ${device})-backing"
 731         else
 732                 backing="${rootmnt}/live/persistent/$(basename ${device})"
 733         fi
 734
 735         mkdir -p "${backing}"
 736         local old_backing="$(where_is_mounted ${device})"
 737         if [ -z "${old_backing}" ]
 738         then
 739                 local fstype="$(get_fstype ${device})"
 740                 local mount_opts="rw,noatime"
 741                 if [ -n "${PERSISTENT_READONLY}" ]
 742                 then
 743                         mount_opts="ro,noatime"
 744                 fi
 745                 if mount -t "${fstype}" -o "${mount_opts}" "${device}" "${backing}" >/dev/null
 746                 then
 747                         echo ${backing}
 748                         return 0
 749                 else
 750                         log_warning_msg "Failed to mount persistent media ${device}"
 751                         return 1
 752                 fi
 753         elif [ "${backing}" != "${old_backing}" ]
 754         then
 755                 if mount --move ${old_backing} ${backing} >/dev/null
 756                 then
 757                         echo ${backing}
 758                         return 0
 759                 else
 760                         log_warning_msg "Failed to move persistent media ${device}"
 761                         return 1
 762                 fi
 763         fi
 764         return 0
 765 }
 766
 767 open_luks_device ()
 768 {
 769         dev="${1}"
 770         name="$(basename ${dev})"
 771         opts="--key-file=-"
 772         if [ -n "${PERSISTENT_READONLY}" ]
 773         then
 774                 opts="${opts} --readonly"
 775         fi
 776
 777         if /sbin/cryptsetup status "${name}" >/dev/null 2>&1
 778         then
 779                 re="^[[:space:]]*device:[[:space:]]*\([^[:space:]]*\)$"
 780                 opened_dev=$(cryptsetup status ${name} 2>/dev/null | grep "${re}" | sed "s|${re}|\1|")
 781                 if [ "${opened_dev}" = "${dev}" ]
 782                 then
 783                         luks_device="/dev/mapper/${name}"
 784                         echo ${luks_device}
 785                         return 0
 786                 else
 787                         log_warning_msg "Cannot open luks device ${dev} since ${opened_dev} already is opened with its name"
 788                         return 1
 789                 fi
 790         fi
 791
 792         load_keymap
 793
 794         while true
 795         do
 796                 /lib/cryptsetup/askpass "Enter passphrase for ${dev}: " | \
 797                         /sbin/cryptsetup -T 1 luksOpen ${dev} ${name} ${opts}
 798
 799                 if [ 0 -eq ${?} ]
 800                 then
 801                         luks_device="/dev/mapper/${name}"
 802                         echo ${luks_device}
 803                         return 0
 804                 fi
 805
 806                 echo >&6
 807                 echo -n "There was an error decrypting ${dev} ... Retry? [Y/n] " >&6
 808                 read answer
 809
 810                 if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
 811                 then
 812                         return 2
 813                 fi
 814         done
 815 }
 816
 817 get_gpt_name ()
 818 {
 819     local dev="${1}"
 820     /sbin/blkid -s PART_ENTRY_NAME -p -o value ${dev} 2>/dev/null
 821 }
 822
 823 is_gpt_device ()
 824 {
 825     local dev="${1}"
 826     [ "$(/sbin/blkid -s PART_ENTRY_SCHEME -p -o value ${dev} 2>/dev/null)" = "gpt" ]
 827 }
 828
 829 probe_for_gpt_name ()
 830 {
 831         local overlays="${1}"
 832         local snapshots="${2}"
 833         local dev="${3}"
 834
 835         local gpt_dev="${dev}"
 836         if is_active_luks_mapping ${dev}
 837         then
 838                 # if $dev is an opened luks device, we need to check
 839                 # GPT stuff on the backing device
 840                 gpt_dev=$(get_luks_backing_device "${dev}")
 841         fi
 842
 843         if ! is_gpt_device ${gpt_dev}
 844         then
 845                 return
 846         fi
 847
 848         local gpt_name=$(get_gpt_name ${gpt_dev})
 849         for label in ${overlays} ${snapshots}
 850         do
 851                 if [ "${gpt_name}" = "${label}" ]
 852                 then
 853                         echo "${label}=${dev}"
 854                 fi
 855         done
 856 }
 857
 858 probe_for_fs_label ()
 859 {
 860         local overlays="${1}"
 861         local snapshots="${2}"
 862         local dev="${3}"
 863
 864         for label in ${overlays} ${snapshots}
 865         do
 866                 if [ "$(/sbin/blkid -s LABEL -o value $dev 2>/dev/null)" = "${label}" ]
 867                 then
 868                         echo "${label}=${dev}"
 869                 fi
 870         done
 871 }
 872
 873 probe_for_file_name ()
 874 {
 875         local overlays="${1}"
 876         local snapshots="${2}"
 877         local dev="${3}"
 878
 879         local ret=""
 880         local backing="$(mount_persistent_media ${dev})"
 881         if [ -z "${backing}" ]
 882         then
 883             return
 884         fi
 885
 886         for label in ${overlays}
 887         do
 888                 path=${backing}/${PERSISTENT_PATH}${label}
 889                 if [ -f "${path}" ]
 890                 then
 891                         local loopdev=$(setup_loop "${path}" "loop" "/sys/block/loop*")
 892                         ret="${ret} ${label}=${loopdev}"
 893                 fi
 894         done
 895         for label in ${snapshots}
 896         do
 897                 for ext in squashfs cpio.gz ext2 ext3 ext4 jffs2
 898                 do
 899                         path="${PERSISTENT_PATH}${label}.${ext}"
 900                         if [ -f "${backing}/${path}" ]
 901                         then
 902                                 ret="${ret} ${label}=${dev}:${backing}:${path}"
 903                         fi
 904                 done
 905         done
 906
 907         if [ -n "${ret}" ]
 908         then
 909                 echo ${ret}
 910         else
 911                 umount ${backing} > /dev/null 2>&1 || true
 912         fi
 913 }
 914
 915 find_persistent_media ()
 916 {
 917         # Scans devices for overlays and snapshots, and returns a whitespace
 918         # separated list of how to use them. Only overlays with a partition
 919         # label or file name in ${overlays} are returned, and ditto for
 920         # snapshots with labels in ${snapshots}.
 921         #
 922         # When scanning a LUKS device, the user will be asked to enter the
 923         # passphrase; on failure to enter it, or if no persistent partitions
 924         # or files were found, the LUKS device is closed.
 925         #
 926         # For a snapshot file the return value is ${label}=${snapdata}", where
 927         # ${snapdata} is the parameter used for try_snap().
 928         #
 929         # For all other cases (overlay/snapshot partition and overlay file) the
 930         # return value is "${label}=${device}", where ${device} a device that
 931         # can mount the content. In the case of an overlay file, the device
 932         # containing the file will remain mounted as a side-effect.
 933         #
 934         # No devices in ${black_listed_devices} will be scanned, and if
 935         # ${white_list_devices} is non-empty, only devices in it will be
 936         # scanned.
 937
 938         local overlays="${1}"
 939         local snapshots="${2}"
 940         local white_listed_devices="${3}"
 941         local ret=""
 942
 943         for dev in $(storage_devices "" "${white_listed_devices}")
 944         do
 945                 local result=""
 946
 947                 local luks_device=""
 948                 # Check if it's a luks device; we'll have to open the device
 949                 # in order to probe any filesystem it contains, like we do
 950                 # below. do_custom_mounts() also depends on that any luks
 951                 # device already has been opened.
 952                 if echo ${PERSISTENT_ENCRYPTION} | grep -qe "\<luks\>" && \
 953                    is_luks_partition ${dev}
 954                 then
 955                         if luks_device=$(open_luks_device "${dev}")
 956                         then
 957                                 dev="${luks_device}"
 958                         else
 959                                 # skip $dev since we failed/chose not to open it
 960                                 continue
 961                         fi
 962                 elif echo ${PERSISTENT_ENCRYPTION} | grep -qve "\<none\>"
 963                 then
 964                         # skip $dev since we don't allow unencrypted storage
 965                         continue
 966                 fi
 967
 968                 # Probe for matching GPT partition names or filesystem labels
 969                 if echo ${PERSISTENT_STORAGE} | grep -qe "\<filesystem\>"
 970                 then
 971                         result=$(probe_for_gpt_name "${overlays}" "${snapshots}" ${dev})
 972                         if [ -n "${result}" ]
 973                         then
 974                                 ret="${ret} ${result}"
 975                                 continue
 976                         fi
 977
 978                         result=$(probe_for_fs_label "${overlays}" "${snapshots}" ${dev})
 979                         if [ -n "${result}" ]
 980                         then
 981                                 ret="${ret} ${result}"
 982                                 continue
 983                         fi
 984                 fi
 985
 986                 # Probe for files with matching name on mounted partition
 987                 if echo ${PERSISTENT_STORAGE} | grep -qe "\<file\>"
 988                 then
 989                         result=$(probe_for_file_name "${overlays}" "${snapshots}" ${dev})
 990                         if [ -n "${result}" ]
 991                         then
 992                                 ret="${ret} ${result}"
 993                                 continue
 994                         fi
 995                 fi
 996
 997                 # Close luks device if it isn't used
 998                 if [ -z "${result}" ] && [ -n "${luks_device}" ] && \
 999                    is_active_luks_mapping "${luks_device}"
1000                 then
1001                         /sbin/cryptsetup luksClose "${luks_device}"
1002                 fi
1003         done
1004
1005         if [ -n "${ret}" ]
1006         then
1007                 echo ${ret}
1008         fi
1009 }
1010
1011 get_mac ()
1012 {
1013         mac=""
1014
1015         for adaptor in /sys/class/net/*
1016         do
1017                 status="$(cat ${adaptor}/iflink)"
1018
1019                 if [ "${status}" -eq 2 ]
1020                 then
1021                         mac="$(cat ${adaptor}/address)"
1022                         mac="$(echo ${mac} | sed 's/:/-/g' | tr '[a-z]' '[A-Z]')"
1023                 fi
1024         done
1025
1026         echo ${mac}
1027 }
1028
1029 is_luks_partition ()
1030 {
1031         device="${1}"
1032         /sbin/cryptsetup isLuks "${device}" 1>/dev/null 2>&1
1033 }
1034
1035 is_active_luks_mapping ()
1036 {
1037         device="${1}"
1038         /sbin/cryptsetup status "${device}" 1>/dev/null 2>&1
1039 }
1040
1041 get_luks_backing_device () {
1042         device=${1}
1043         cryptsetup status ${device} 2> /dev/null | \
1044                 awk '{if ($1 == "device:") print $2}'
1045 }
1046
1047 removable_dev ()
1048 {
1049         output_format="${1}"
1050         want_usb="${2}"
1051         ret=
1052
1053         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "/(loop|ram|dm-|fd)")
1054         do
1055                 dev_ok=
1056                 if [ "$(cat ${sysblock}/removable)" = "1" ]
1057                 then
1058                         if [ -z "${want_usb}" ]
1059                         then
1060                                 dev_ok="yes"
1061                         else
1062                                 if readlink ${sysblock} | grep -q usb
1063                                 then
1064                                         dev_ok="yes"
1065                                 fi
1066                         fi
1067                 fi
1068
1069                 if [ "${dev_ok}" = "yes" ]
1070                 then
1071                         case "${output_format}" in
1072                                 sys)
1073                                         ret="${ret} ${sysblock}"
1074                                         ;;
1075                                 *)
1076                                         devname=$(sys2dev "${sysblock}")
1077                                         ret="${ret} ${devname}"
1078                                         ;;
1079                         esac
1080                 fi
1081         done
1082
1083         echo "${ret}"
1084 }
1085
1086 removable_usb_dev ()
1087 {
1088         output_format="${1}"
1089
1090         removable_dev "${output_format}" "want_usb"
1091 }
1092
1093 non_removable_dev ()
1094 {
1095         output_format="${1}"
1096         ret=
1097
1098         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "/(loop|ram|dm-|fd)")
1099         do
1100                 if [ "$(cat ${sysblock}/removable)" = "0" ]
1101                 then
1102                         case "${output_format}" in
1103                                 sys)
1104                                         ret="${ret} ${sysblock}"
1105                                         ;;
1106                                 *)
1107                                         devname=$(sys2dev "${sysblock}")
1108                                         ret="${ret} ${devname}"
1109                                         ;;
1110                         esac
1111                 fi
1112         done
1113
1114         echo "${ret}"
1115 }
1116
1117 link_files ()
1118 {
1119         # create source's directory structure in dest, and recursively
1120         # create symlinks in dest to to all files in source. if mask
1121         # is non-empty, remove mask from all source paths when
1122         # creating links (will be necessary if we change root, which
1123         # live-boot normally does (into $rootmnt)).
1124
1125         # remove multiple /:s and ensure ending on /
1126         local src_dir="$(echo "${1}"/ | sed -e 's|/\+|/|g')"
1127         local dest_dir="$(echo "${2}"/ | sed -e 's|/\+|/|g')"
1128         local src_mask="${3}"
1129
1130         # This check can only trigger on the inital, non-recursive call since
1131         # we create the destination before recursive calls
1132         if [ ! -d "${dest_dir}" ]
1133         then
1134                 log_warning_msg "Must link_files into a directory"
1135                 return
1136         fi
1137
1138         find "${src_dir}" -mindepth 1 -maxdepth 1 | while read src; do
1139                 local dest="${dest_dir}$(basename "${src}")"
1140                 if [ -d "${src}" ]
1141                 then
1142                         if [ -z "$(ls -A "${src}")" ]
1143                         then
1144                                 continue
1145                         fi
1146                         if [ ! -d "${dest}" ]
1147                         then
1148                                 mkdir -p "${dest}"
1149                                 prev="$(dirname "${dest}")"
1150                                 chown --reference "${prev}" "${dest}"
1151                                 chmod --reference "${prev}" "${dest}"
1152                         fi
1153                         link_files "${src}" "${dest}" "${src_mask}"
1154                 else
1155                         if [ -n "${src_mask}" ]
1156                         then
1157                                 src="$(echo ${src} | sed "s|^${src_mask}||")"
1158                         fi
1159                         rm -rf "${dest}" 2> /dev/null
1160                         ln -s "${src}" "${dest}"
1161                 fi
1162         done
1163 }
1164
1165 do_union ()
1166 {
1167         local unionmountpoint="${1}"    # directory where the union is mounted
1168         local unionrw="${2}"            # branch where the union changes are stored
1169         local unionro1="${3}"           # first underlying read-only branch (optional)
1170         local unionro2="${4}"           # second underlying read-only branch (optional)
1171
1172         if [ "${UNIONTYPE}" = "aufs" ]
1173         then
1174                 rw_opt="rw"
1175                 ro_opt="rr+wh"
1176                 noxino_opt="noxino"
1177         elif [ "${UNIONTYPE}" = "unionfs-fuse" ]
1178         then
1179                 rw_opt="RW"
1180                 ro_opt="RO"
1181         else
1182                 rw_opt="rw"
1183                 ro_opt="ro"
1184         fi
1185
1186         case "${UNIONTYPE}" in
1187                 unionfs-fuse)
1188                         unionmountopts="-o cow -o noinitgroups -o default_permissions -o allow_other -o use_ino -o suid"
1189                         unionmountopts="${unionmountopts} ${unionrw}=${rw_opt}"
1190                         if [ -n "${unionro1}" ]
1191                         then
1192                                 unionmountopts="${unionmountopts}:${unionro1}=${ro_opt}"
1193                         fi
1194                         if [ -n "${unionro2}" ]
1195                         then
1196                                 unionmountopts="${unionmountopts}:${unionro2}=${ro_opt}"
1197                         fi
1198                         ( sysctl -w fs.file-max=391524 ; ulimit -HSn 16384
1199                         unionfs-fuse ${unionmountopts} "${unionmountpoint}" ) && \
1200                         ( mkdir -p /run/sendsigs.omit.d
1201                         pidof unionfs-fuse >> /run/sendsigs.omit.d/unionfs-fuse || true )
1202                         ;;
1203
1204                 overlayfs)
1205                         # XXX: can unionro2 be used? (overlayfs only handles two dirs, but perhaps they can be chained?)
1206                         # XXX: and can unionro1 be optional? i.e. can overlayfs skip lowerdir?
1207                         unionmountopts="-o noatime,lowerdir=${unionro1},upperdir=${unionrw}"
1208                         mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
1209                         ;;
1210
1211                 *)
1212                         unionmountopts="-o noatime,${noxino_opt},dirs=${unionrw}=${rw_opt}"
1213                         if [ -n "${unionro1}" ]
1214                         then
1215                                 unionmountopts="${unionmountopts}:${unionro1}=${ro_opt}"
1216                         fi
1217                         if [ -n "${unionro2}" ]
1218                         then
1219                                 unionmountopts="${unionmountopts}:${unionro2}=${ro_opt}"
1220                         fi
1221                         mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
1222                         ;;
1223         esac
1224 }
1225
1226 get_custom_mounts ()
1227 {
1228         # Side-effect: leaves $devices with live.persist mounted in ${rootmnt}/live/persistent
1229         # Side-effect: prints info to file $custom_mounts
1230
1231         local custom_mounts=${1}
1232         shift
1233         local devices=${@}
1234
1235         local bindings="/tmp/bindings.list"
1236         local links="/tmp/links.list"
1237         rm -rf ${bindings} ${links} 2> /dev/null
1238
1239         for device in ${devices}
1240         do
1241                 if [ ! -b "${device}" ]
1242                 then
1243                         continue
1244                 fi
1245
1246                 local device_name="$(basename ${device})"
1247                 local device_used=""
1248                 local backing=$(mount_persistent_media ${device})
1249                 if [ -z "${backing}" ]
1250                 then
1251                         continue
1252                 fi
1253
1254                 local include_list="${backing}/${persistence_list}"
1255                 if [ ! -r "${include_list}" ]
1256                 then
1257                         umount "${backing}" >/dev/null 2>&1
1258                         rmdir "${backing}" >/dev/null 2>&1
1259                         if /sbin/cryptsetup status ${device_name} >/dev/null 2>&1
1260                         then
1261                                 /sbin/cryptsetup luksClose "${device_name}"
1262                         fi
1263                         continue
1264                 fi
1265
1266                 if [ -n "${DEBUG}" ] && [ -e "${include_list}" ]
1267                 then
1268                         cp ${include_list} ${rootmnt}/live/persistent/${persistence_list}.${device_name}
1269                 fi
1270
1271                 while read source dest options # < ${include_list}
1272                 do
1273                         if echo ${source} | grep -qe "^[[:space:]]*\(#.*\)\?$"
1274                         then
1275                                 # skipping empty or commented lines
1276                                 continue
1277                         fi
1278
1279                         if echo ${dest} | grep -qe "^[^/]"
1280                         then
1281                                 options="${dest}"
1282                                 dest="${source}"
1283                         elif [ -z "${dest}" ]
1284                         then
1285                                 dest="${source}"
1286                         fi
1287
1288                         if trim_path ${source} | grep -qe "^\(.*/\)\?\.\.\?\(/.*\)\?$"
1289                         then
1290                                 log_warning_msg "Skipping unsafe custom mount with source ${source}: the source is a relative or absolute path w.r.t. the persistent media root and cannot use \".\" or \"..\""
1291                                 continue
1292                         fi
1293
1294                         if trim_path ${dest} | grep -q -e "^/$" -e "^/live\(/.*\)\?$" -e "^/\(.*/\)\?\.\.\?\(/.*\)\?$"
1295                         then
1296                                 log_warning_msg "Skipping unsafe custom mount with desination ${dest}: the destination must be an absolute path using neither \".\" nor \"..\", and cannot be /live (or any sub-directory therein) or / (for the latter, use ${root_overlay_label}-type persistence instead)"
1297                                 continue
1298                         fi
1299
1300                         for opt in $(echo ${options} | tr ',' ' ');
1301                         do
1302                                 case "${opt}" in
1303                                         linkfiles|union)
1304                                                 ;;
1305                                         *)
1306                                                 log_warning_msg "Skipping custom mount with unkown option: ${opt}"
1307                                                 continue 2
1308                                                 ;;
1309                                 esac
1310                         done
1311
1312                         # ensure that no multiple-/ occur in paths
1313                         local full_source="$(trim_path ${backing}/${source})"
1314                         local full_dest="$(trim_path ${rootmnt}/${dest})"
1315                         device_used="yes"
1316                         if echo ${options} | grep -qe "\<linkfiles\>";
1317                         then
1318                                 echo "${full_source} ${full_dest} ${options}" >> ${links}
1319                         else
1320                                 echo "${full_source} ${full_dest} ${options}" >> ${bindings}
1321                         fi
1322                 done < ${include_list}
1323
1324                 if [ -z "${device_used}" ]
1325                 then
1326                         # this device was not used for / earlier, or
1327                         # custom mount point now, so it's useless
1328                         umount "${backing}"
1329                         rmdir "${backing}"
1330                 fi
1331         done
1332
1333         # We sort the list according to destination so we're sure that
1334         # we won't hide a previous mount. We also ignore duplicate
1335         # destinations in a more or less arbitrary way.
1336         [ -e "${bindings}" ] && sort -k2 -sbu ${bindings} >> ${custom_mounts} && rm ${bindings}
1337
1338         # After all mounts are considered we add symlinks so they
1339         # won't be hidden by some mount.
1340         [ -e "${links}" ] && sort -k2 -sbu ${links} >> ${custom_mounts} && rm ${links}
1341 }
1342
1343 do_custom_mounts ()
1344 {
1345         local custom_mounts="${1}" # the ouput from get_custom_mounts()
1346
1347         while read source dest options # < ${custom_mounts}
1348         do
1349                 local opt_linkfiles=""
1350                 local opt_union=""
1351                 for opt in $(echo ${options} | tr ',' ' ');
1352                 do
1353                          case "${opt}" in
1354                                 linkfiles)
1355                                         opt_linkfiles="yes"
1356                                         ;;
1357                                 union)
1358                                         opt_union="yes"
1359                                         ;;
1360                         esac
1361                 done
1362
1363                 if [ -n "$(what_is_mounted_on "${dest}")" ]
1364                 then
1365                         log_warning_msg "Skipping custom mount ${source} on ${dest}: $(what_is_mounted_on "${dest}") is already mounted there"
1366                         continue
1367                 fi
1368
1369                 # FIXME: we don't handle already existing
1370                 # non-directory files in the paths of both $source and
1371                 # $dest.
1372
1373                 if [ ! -d "${dest}" ]
1374                 then
1375                         # if ${dest} is in /home/$user, try fixing
1376                         # proper ownership
1377                         # FIXME: this should really be handled by
1378                         # live-config since we don't know for sure
1379                         # which uid a certain user has until then
1380                         if trim_path ${dest} | grep -qe "^${rootmnt}/*home/[^/]\+"
1381                         then
1382                                 path="/"
1383                                 for dir in $(echo ${dest} | sed -e 's|/\+| |g')
1384                                 do
1385                                         path=${path}/${dir}
1386                                         if [ ! -e ${path} ]
1387                                         then
1388                                                 mkdir -p ${path}
1389                                                 # assume that the intended user is the first, which is usually the case
1390                                                 chown 1000:1000 ${path}
1391                                         fi
1392                                 done
1393                         else
1394                                 mkdir -p ${dest}
1395                         fi
1396                 fi
1397
1398                 # if ${source} doesn't exist on our persistent media
1399                 # we bootstrap it with $dest from the live filesystem.
1400                 # this both makes sense and is critical if we're
1401                 # dealing with /etc or other system dir.
1402                 if [ ! -d "${source}" ]
1403                 then
1404                         if [ -n "${PERSISTENT_READONLY}" ] || [ -n "${opt_linkfiles}" ]
1405                         then
1406                                 continue
1407                         elif [ -n "${opt_union}" ]
1408                         then
1409                                 # union's don't need to be bootstrapped
1410                                 mkdir "${source}"
1411                         else
1412                                 # ensure that $dest is not copied *into* $source
1413                                 mkdir -p "$(dirname ${source})"
1414                                 cp -a "${dest}" "${source}"
1415                         fi
1416                 fi
1417
1418                 rofs_dest_backing=""
1419                 for d in ${rootmnt}/live/rofs/*
1420                 do
1421                         if [ -n "${rootmnt}" ]
1422                         then
1423                                 rofs_dest_backing="${d}/$(echo ${dest} | sed -e "s|${rootmnt}||")"
1424                         else
1425                                 rofs_dest_backing="${d}/${dest}"
1426                         fi
1427                         if [ -d "${rofs_dest_backing}" ]
1428                         then
1429                                 break
1430                         else
1431                                 rofs_dest_backing=""
1432                         fi
1433                 done
1434
1435                 if [ -z "${PERSISTENT_READONLY}" ]
1436                 then
1437                         if [ -n "${opt_linkfiles}" ]
1438                         then
1439                                 links_source="${source}"
1440                                 links_dest="${dest}"
1441                         elif [ -n "${opt_union}" ]
1442                         then
1443                                 do_union ${dest} ${source} ${rofs_dest_backing}
1444                         else
1445                                 mount --bind "${source}" "${dest}"
1446                         fi
1447                 else
1448                         if [ -n "${opt_linkfiles}" ]
1449                         then
1450                                 links_dest="${dest}"
1451                                 dest="$(mktemp -d ${persistent_backing}/links_source-XXXXXX)"
1452                                 links_source="${dest}"
1453                         fi
1454                         if [ -n "${rootmnt}" ]
1455                         then
1456                                 cow_dir="$(echo ${dest} | sed -e "s|${rootmnt}|/cow/|")"
1457                         else
1458                                 cow_dir="/live/cow/${dest}"
1459                         fi
1460                         mkdir -p ${cow_dir}
1461                         do_union ${dest} ${cow_dir} ${source} ${rofs_dest_backing}
1462                 fi
1463
1464                 if [ -n "${opt_linkfiles}" ]
1465                 then
1466                         link_files "${links_source}" "${links_dest}" "${rootmnt}"
1467                 fi
1468
1469                 PERSISTENCE_IS_ON="1"
1470                 export PERSISTENCE_IS_ON
1471         done < ${custom_mounts}
1472 }
1473
1474 fix_home_rw_compatibility ()
1475 {
1476         local device=${1}
1477
1478         if [ -n "${PERSISTENT_READONLY}" ]
1479         then
1480                 return
1481         fi
1482
1483         local backing="$(mount_persistent_media ${device})"
1484         if [ -z "${backing}" ]
1485         then
1486                 return
1487         fi
1488
1489         local include_list="${backing}/${persistence_list}"
1490         if [ ! -r "${include_list}" ]
1491         then
1492                 echo "# home-rw backwards compatibility:
1493 / /home" > "${include_list}"
1494         fi
1495 }