Move check for block device to mount_persistence_media().
[live-boot-grml.git] / 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 is_in_list_separator_helper ()
333 {
334         local sep element list
335         sep=${1}
336         shift
337         element=${1}
338         shift
339         list=${*}
340         echo ${list} | grep -qe "^\(.*${sep}\)\?${element}\(${sep}.*\)\?$"
341 }
342
343 is_in_space_sep_list ()
344 {
345         local element
346         element=${1}
347         shift
348         is_in_list_separator_helper "[[:space:]]" "${element}" "${*}"
349 }
350
351 is_in_comma_sep_list ()
352 {
353         local element
354         element=${1}
355         shift
356         is_in_list_separator_helper "," "${element}" "${*}"
357 }
358
359 sys2dev ()
360 {
361         sysdev=${1#/sys}
362         echo "/dev/$(udevadm info -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})"
363 }
364
365 subdevices ()
366 {
367         sysblock=${1}
368         r=""
369
370         for dev in "${sysblock}"/* "${sysblock}"
371         do
372                 if [ -e "${dev}/dev" ]
373                 then
374                         r="${r} ${dev}"
375                 fi
376         done
377
378         echo ${r}
379 }
380
381 storage_devices()
382 {
383         black_listed_devices="${1}"
384         white_listed_devices="${2}"
385
386         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "loop|ram|fd")
387         do
388                 fulldevname=$(sys2dev "${sysblock}")
389
390                 if is_in_space_sep_list ${fulldevname} ${black_listed_devices} || \
391                         [ -n "${white_listed_devices}" ] && \
392                         ! is_in_space_sep_list ${fulldevname} ${white_listed_devices}
393                 then
394                         # skip this device entirely
395                         continue
396                 fi
397
398                 for dev in $(subdevices "${sysblock}")
399                 do
400                         devname=$(sys2dev "${dev}")
401
402                         if is_in_space_sep_list ${devname} ${black_listed_devices}
403                         then
404                                 # skip this subdevice
405                                 continue
406                         else
407                                 echo "${devname}"
408                         fi
409                 done
410         done
411 }
412
413 is_supported_fs ()
414 {
415         fstype="${1}"
416
417         # Validate input first
418         if [ -z "${fstype}" ]
419         then
420                 return 1
421         fi
422
423         # Try to look if it is already supported by the kernel
424         if grep -q ${fstype} /proc/filesystems
425         then
426                 return 0
427         else
428                 # Then try to add support for it the gentle way using the initramfs capabilities
429                 modprobe ${fstype}
430                 if grep -q ${fstype} /proc/filesystems
431                 then
432                         return 0
433                 # Then try the hard way if /root is already reachable
434                 else
435                         kmodule="/root/lib/modules/`uname -r`/${fstype}/${fstype}.ko"
436                         if [ -e "${kmodule}" ]
437                         then
438                                 insmod "${kmodule}"
439                                 if grep -q ${fstype} /proc/filesystems
440                                 then
441                                         return 0
442                                 fi
443                         fi
444                 fi
445         fi
446
447         return 1
448 }
449
450 get_fstype ()
451 {
452         /sbin/blkid -s TYPE -o value $1 2>/dev/null
453 }
454
455 where_is_mounted ()
456 {
457         device=${1}
458         # return first found
459         grep -m1 "^${device} " /proc/mounts | cut -f2 -d ' '
460 }
461
462 trim_path ()
463 {
464         # remove all unnecessary /:s in the path, including last one (except
465         # if path is just "/")
466         echo ${1} | sed 's|//\+|/|g' | sed 's|^\(.*[^/]\)/$|\1|'
467 }
468
469 what_is_mounted_on ()
470 {
471         local dir
472         dir="$(trim_path ${1})"
473         grep -m1 "^[^ ]\+ ${dir} " /proc/mounts | cut -d' ' -f1
474 }
475
476 chown_ref ()
477 {
478         local reference targets owner
479         reference="${1}"
480         shift
481         targets=${@}
482         owner=$(stat -c %u:%g "${reference}")
483         chown -h ${owner} ${targets}
484 }
485
486 chmod_ref ()
487 {
488         local reference targets rights
489         reference="${1}"
490         shift
491         targets=${@}
492         rights=$(stat -c %a "${reference}")
493         chmod ${rights} ${targets}
494 }
495
496 lastline ()
497 {
498         while read lines
499         do
500                 line=${lines}
501         done
502
503         echo "${line}"
504 }
505
506 base_path ()
507 {
508         testpath="${1}"
509         mounts="$(awk '{print $2}' /proc/mounts)"
510         testpath="$(busybox realpath ${testpath})"
511
512         while true
513         do
514                 if echo "${mounts}" | grep -qs "^${testpath}"
515                 then
516                         set -- $(echo "${mounts}" | grep "^${testpath}" | lastline)
517                         echo ${1}
518                         break
519                 else
520                         testpath=$(dirname $testpath)
521                 fi
522         done
523 }
524
525 fs_size ()
526 {
527         # Returns used/free fs kbytes + 5% more
528         # You could pass a block device as ${1} or the mount point as ${2}
529
530         dev="${1}"
531         mountp="${2}"
532         used="${3}"
533
534         if [ -z "${mountp}" ]
535         then
536                 mountp="$(where_is_mounted ${dev})"
537
538                 if [ -z "${mountp}" ]
539                 then
540                         mountp="/mnt/tmp_fs_size"
541
542                         mkdir -p "${mountp}"
543                         mount -t $(get_fstype "${dev}") -o ro "${dev}" "${mountp}" || log_warning_msg "cannot mount -t $(get_fstype ${dev}) -o ro ${dev} ${mountp}"
544
545                         doumount=1
546                 fi
547         fi
548
549         if [ "${used}" = "used" ]
550         then
551                 size=$(du -ks ${mountp} | cut -f1)
552                 size=$(expr ${size} + ${size} / 20 ) # FIXME: 5% more to be sure
553         else
554                 # free space
555                 size="$(df -kP | grep -s ${mountp} | awk '{print $4}')"
556         fi
557
558         if [ -n "${doumount}" ]
559         then
560                 umount "${mountp}" || log_warning_msg "cannot umount ${mountp}"
561                 rmdir "${mountp}"
562         fi
563
564         echo "${size}"
565 }
566
567 load_keymap ()
568 {
569         # Load custom keymap
570         if [ -x /bin/loadkeys -a -r /etc/boottime.kmap.gz ]
571         then
572                 loadkeys --quiet /etc/boottime.kmap.gz
573         fi
574 }
575
576 setup_loop ()
577 {
578         local fspath module pattern offset encryption readonly
579         fspath=${1}
580         module=${2}
581         pattern=${3}
582         offset=${4}
583         encryption=${5}
584         readonly=${6}
585
586         # the output of setup_loop is evaluated in other functions,
587         # modprobe leaks kernel options like "libata.dma=0"
588         # as "options libata dma=0" on stdout, causing serious
589         # problems therefor, so instead always avoid output to stdout
590         modprobe -q -b "${module}" 1>/dev/null
591
592         udevadm settle
593
594         for loopdev in ${pattern}
595         do
596                 if [ "$(cat ${loopdev}/size)" -eq 0 ]
597                 then
598                         dev=$(sys2dev "${loopdev}")
599                         options=''
600
601                         if [ -n "${readonly}" ]
602                         then
603                                 if losetup --help 2>&1 | grep -q -- "-r\b"
604                                 then
605                                         options="${options} -r"
606                                 fi
607                         fi
608
609                         if [ -n "${offset}" ] && [ 0 -lt "${offset}" ]
610                         then
611                                 options="${options} -o ${offset}"
612                         fi
613
614                         if [ -z "${encryption}" ]
615                         then
616                                 losetup ${options} "${dev}" "${fspath}"
617                         else
618                                 # Loop AES encryption
619                                 while true
620                                 do
621                                         load_keymap
622
623                                         echo -n "Enter passphrase for root filesystem: " >&6
624                                         read -s passphrase
625                                         echo "${passphrase}" > /tmp/passphrase
626                                         unset passphrase
627                                         exec 9</tmp/passphrase
628                                         /sbin/losetup ${options} -e "${encryption}" -p 9 "${dev}" "${fspath}"
629                                         error=${?}
630                                         exec 9<&-
631                                         rm -f /tmp/passphrase
632
633                                         if [ 0 -eq ${error} ]
634                                         then
635                                                 unset error
636                                                 break
637                                         fi
638
639                                         echo
640                                         echo -n "There was an error decrypting the root filesystem ... Retry? [Y/n] " >&6
641                                         read answer
642
643                                         if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
644                                         then
645                                                 unset answer
646                                                 break
647                                         fi
648                                 done
649                         fi
650
651                         echo "${dev}"
652                         return 0
653                 fi
654         done
655
656         panic "No loop devices available"
657 }
658
659 try_mount ()
660 {
661         dev="${1}"
662         mountp="${2}"
663         opts="${3}"
664         fstype="${4}"
665
666         old_mountp="$(where_is_mounted ${dev})"
667
668         if [ -n "${old_mountp}" ]
669         then
670                 if [ "${opts}" != "ro" ]
671                 then
672                         mount -o remount,"${opts}" "${dev}" "${old_mountp}" || panic "Remounting ${dev} ${opts} on ${old_mountp} failed"
673                 fi
674
675                 mount -o bind "${old_mountp}" "${mountp}" || panic "Cannot bind-mount ${old_mountp} on ${mountp}"
676         else
677                 if [ -z "${fstype}" ]
678                 then
679                         fstype=$(get_fstype "${dev}")
680                 fi
681                 mount -t "${fstype}" -o "${opts}" "${dev}" "${mountp}" || \
682                 ( echo "SKIPPING: Cannot mount ${dev} on ${mountp}, fstype=${fstype}, options=${opts}" > boot.log && return 0 )
683         fi
684 }
685
686 # Try to mount $device to the place expected by live-boot. If $device
687 # is already mounted somewhere, move it to the expected place. If
688 # we're only probing $device (to check if it has custom persistence)
689 # $probe should be set, which suppresses warnings upon failure. On
690 # success, print the mount point for $device.
691 mount_persistence_media ()
692 {
693         local device probe backing old_backing fstype mount_opts
694         device=${1}
695         probe=${2}
696
697         if [ ! -b "${device}" ]
698         then
699                 return 1
700         fi
701
702         backing="/live/persistence/$(basename ${device})"
703
704         mkdir -p "${backing}"
705         old_backing="$(where_is_mounted ${device})"
706         if [ -z "${old_backing}" ]
707         then
708                 fstype="$(get_fstype ${device})"
709                 mount_opts="rw,noatime"
710                 if [ -n "${PERSISTENCE_READONLY}" ]
711                 then
712                         mount_opts="ro,noatime"
713                 fi
714                 if mount -t "${fstype}" -o "${mount_opts}" "${device}" "${backing}" >/dev/null
715                 then
716                         echo ${backing}
717                         return 0
718                 else
719                         [ -z "${probe}" ] && log_warning_msg "Failed to mount persistence media ${device}"
720                         rmdir "${backing}"
721                         return 1
722                 fi
723         elif [ "${backing}" != "${old_backing}" ]
724         then
725                 if mount --move ${old_backing} ${backing} >/dev/null
726                 then
727                         echo ${backing}
728                         return 0
729                 else
730                         [ -z "${probe}" ] && log_warning_msg "Failed to move persistence media ${device}"
731                         rmdir "${backing}"
732                         return 1
733                 fi
734         else
735                 # This means that $device has already been mounted on
736                 # the place expected by live-boot, so we're done.
737                 echo ${backing}
738                 return 0
739         fi
740 }
741
742 close_persistence_media ()
743 {
744         local device backing
745         device=${1}
746         backing="$(where_is_mounted ${device})"
747
748         if [ -d "${backing}" ]
749         then
750                 umount "${backing}" >/dev/null 2>&1
751                 rmdir "${backing}" >/dev/null 2>&1
752         fi
753
754         if is_active_luks_mapping ${device}
755         then
756                 /sbin/cryptsetup luksClose ${device}
757         fi
758 }
759
760 open_luks_device ()
761 {
762         dev="${1}"
763         name="$(basename ${dev})"
764         opts="--key-file=-"
765         if [ -n "${PERSISTENCE_READONLY}" ]
766         then
767                 opts="${opts} --readonly"
768         fi
769
770         if /sbin/cryptsetup status "${name}" >/dev/null 2>&1
771         then
772                 re="^[[:space:]]*device:[[:space:]]*\([^[:space:]]*\)$"
773                 opened_dev=$(cryptsetup status ${name} 2>/dev/null | grep "${re}" | sed "s|${re}|\1|")
774                 if [ "${opened_dev}" = "${dev}" ]
775                 then
776                         luks_device="/dev/mapper/${name}"
777                         echo ${luks_device}
778                         return 0
779                 else
780                         log_warning_msg "Cannot open luks device ${dev} since ${opened_dev} already is opened with its name"
781                         return 1
782                 fi
783         fi
784
785         load_keymap
786
787         while true
788         do
789                 /lib/cryptsetup/askpass "Enter passphrase for ${dev}: " | \
790                         /sbin/cryptsetup -T 1 luksOpen ${dev} ${name} ${opts}
791
792                 if [ 0 -eq ${?} ]
793                 then
794                         luks_device="/dev/mapper/${name}"
795                         echo ${luks_device}
796                         return 0
797                 fi
798
799                 echo >&6
800                 echo -n "There was an error decrypting ${dev} ... Retry? [Y/n] " >&6
801                 read answer
802
803                 if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
804                 then
805                         return 2
806                 fi
807         done
808 }
809
810 get_gpt_name ()
811 {
812     local dev
813     dev="${1}"
814     /sbin/blkid -s PART_ENTRY_NAME -p -o value ${dev} 2>/dev/null
815 }
816
817 is_gpt_device ()
818 {
819     local dev
820     dev="${1}"
821     [ "$(/sbin/blkid -s PART_ENTRY_SCHEME -p -o value ${dev} 2>/dev/null)" = "gpt" ]
822 }
823
824 probe_for_gpt_name ()
825 {
826         local overlays dev gpt_dev gpt_name
827         overlays="${1}"
828         dev="${2}"
829
830         gpt_dev="${dev}"
831         if is_active_luks_mapping ${dev}
832         then
833                 # if $dev is an opened luks device, we need to check
834                 # GPT stuff on the backing device
835                 gpt_dev=$(get_luks_backing_device "${dev}")
836         fi
837
838         if ! is_gpt_device ${gpt_dev}
839         then
840                 return
841         fi
842
843         gpt_name=$(get_gpt_name ${gpt_dev})
844         for label in ${overlays}
845         do
846                 if [ "${gpt_name}" = "${label}" ]
847                 then
848                         echo "${label}=${dev}"
849                 fi
850         done
851 }
852
853 probe_for_fs_label ()
854 {
855         local overlays dev
856         overlays="${1}"
857         dev="${2}"
858
859         for label in ${overlays}
860         do
861                 if [ "$(/sbin/blkid -s LABEL -o value $dev 2>/dev/null)" = "${label}" ]
862                 then
863                         echo "${label}=${dev}"
864                 fi
865         done
866 }
867
868 probe_for_file_name ()
869 {
870         local overlays dev ret backing
871         overlays="${1}"
872         dev="${2}"
873
874         ret=""
875         backing="$(mount_persistence_media ${dev} probe)"
876         if [ -z "${backing}" ]
877         then
878             return
879         fi
880
881         for label in ${overlays}
882         do
883                 path=${backing}/${PERSISTENCE_PATH}/${label}
884                 if [ -f "${path}" ]
885                 then
886                         local loopdev
887                         loopdev=$(setup_loop "${path}" "loop" "/sys/block/loop*")
888                         ret="${ret} ${label}=${loopdev}"
889                 fi
890         done
891
892         if [ -n "${ret}" ]
893         then
894                 echo ${ret}
895         else
896                 # unmount and remove mountpoint
897                 umount ${backing} > /dev/null 2>&1 || true
898                 rmdir ${backing} > /dev/null 2>&1 || true
899         fi
900 }
901
902 find_persistence_media ()
903 {
904         # Scans devices for overlays, and returns a whitespace
905         # separated list of how to use them. Only overlays with a partition
906         # label or file name in ${overlays} are returned.
907         #
908         # When scanning a LUKS device, the user will be asked to enter the
909         # passphrase; on failure to enter it, or if no persistence partitions
910         # or files were found, the LUKS device is closed.
911         #
912         # For all other cases (overlay partition and overlay file) the
913         # return value is "${label}=${device}", where ${device} a device that
914         # can mount the content. In the case of an overlay file, the device
915         # containing the file will remain mounted as a side-effect.
916         #
917         # No devices in ${black_listed_devices} will be scanned, and if
918         # ${white_list_devices} is non-empty, only devices in it will be
919         # scanned.
920
921         local overlays white_listed_devices ret black_listed_devices
922         overlays="${1}"
923         white_listed_devices="${2}"
924         ret=""
925
926         black_listed_devices="$(what_is_mounted_on /live/medium) $(what_is_mounted_on /live/findiso) $(what_is_mounted_on /live/fromiso)"
927
928         for dev in $(storage_devices "${black_listed_devices}" "${white_listed_devices}")
929         do
930                 local result luks_device
931                 result=""
932
933                 luks_device=""
934                 # Check if it's a luks device; we'll have to open the device
935                 # in order to probe any filesystem it contains, like we do
936                 # below. activate_custom_mounts() also depends on that any luks
937                 # device already has been opened.
938                 if is_in_comma_sep_list luks ${PERSISTENCE_ENCRYPTION} && is_luks_partition ${dev}
939                 then
940                         if luks_device=$(open_luks_device "${dev}")
941                         then
942                                 dev="${luks_device}"
943                         else
944                                 # skip $dev since we failed/chose not to open it
945                                 continue
946                         fi
947                 elif ! is_in_comma_sep_list none ${PERSISTENCE_ENCRYPTION}
948                 then
949                         # skip $dev since we don't allow unencrypted storage
950                         continue
951                 fi
952
953                 # Probe for matching GPT partition names or filesystem labels
954                 if is_in_comma_sep_list filesystem ${PERSISTENCE_STORAGE}
955                 then
956                         result=$(probe_for_gpt_name "${overlays}" ${dev})
957                         if [ -n "${result}" ]
958                         then
959                                 ret="${ret} ${result}"
960                                 continue
961                         fi
962
963                         result=$(probe_for_fs_label "${overlays}" ${dev})
964                         if [ -n "${result}" ]
965                         then
966                                 ret="${ret} ${result}"
967                                 continue
968                         fi
969                 fi
970
971                 # Probe for files with matching name on mounted partition
972                 if is_in_comma_sep_list file ${PERSISTENCE_STORAGE}
973                 then
974                         result=$(probe_for_file_name "${overlays}" ${dev})
975                         if [ -n "${result}" ]
976                         then
977                                 local loopdevice
978                                 loopdevice=${result##*=}
979                                 if is_in_comma_sep_list luks ${PERSISTENCE_ENCRYPTION} && is_luks_partition ${loopdevice}
980                                 then
981                                         local luksfile
982                                         luksfile=""
983                                         if luksfile=$(open_luks_device "${loopdevice}")
984                                         then
985                                                 result=${result%%=*}
986                                                 result="${result}=${luksfile}"
987                                         else
988                                                 losetup -d $loopdevice
989                                                 result=""
990                                         fi
991                                 fi
992                                 ret="${ret} ${result}"
993                                 continue
994                         fi
995                 fi
996
997                 # Close luks device if it isn't used
998                 if [ -z "${result}" ] && [ -n "${luks_device}" ] && is_active_luks_mapping "${luks_device}"
999                 then
1000                         /sbin/cryptsetup luksClose "${luks_device}"
1001                 fi
1002         done
1003
1004         if [ -n "${ret}" ]
1005         then
1006                 echo ${ret}
1007         fi
1008 }
1009
1010 get_mac ()
1011 {
1012         mac=""
1013
1014         for adaptor in /sys/class/net/*
1015         do
1016                 status="$(cat ${adaptor}/iflink)"
1017
1018                 if [ "${status}" -eq 2 ]
1019                 then
1020                         mac="$(cat ${adaptor}/address)"
1021                         mac="$(echo ${mac} | sed 's/:/-/g' | tr '[a-z]' '[A-Z]')"
1022                 fi
1023         done
1024
1025         echo ${mac}
1026 }
1027
1028 is_luks_partition ()
1029 {
1030         device="${1}"
1031         /sbin/cryptsetup isLuks "${device}" 1>/dev/null 2>&1
1032 }
1033
1034 is_active_luks_mapping ()
1035 {
1036         device="${1}"
1037         /sbin/cryptsetup status "${device}" 1>/dev/null 2>&1
1038 }
1039
1040 get_luks_backing_device ()
1041 {
1042         device=${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="true"
1061                         else
1062                                 if readlink ${sysblock} | grep -q usb
1063                                 then
1064                                         dev_ok="true"
1065                                 fi
1066                         fi
1067                 fi
1068
1069                 if [ "${dev_ok}" = "true" ]
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 $rootmnt)).
1124         local src_dir dest_dir src_transform
1125
1126         # remove multiple /:s and ensure ending on /
1127         src_dir="$(trim_path ${1})/"
1128         dest_dir="$(trim_path ${2})/"
1129         src_transform="${3}"
1130
1131         # This check can only trigger on the inital, non-recursive call since
1132         # we create the destination before recursive calls
1133         if [ ! -d "${dest_dir}" ]
1134         then
1135                 log_warning_msg "Must link_files into a directory"
1136                 return
1137         fi
1138
1139         find "${src_dir}" -mindepth 1 -maxdepth 1 | \
1140         while read src
1141         do
1142                 local dest final_src
1143                 dest="${dest_dir}$(basename "${src}")"
1144                 if [ -d "${src}" ]
1145                 then
1146                         if [ -z "$(ls -A "${src}")" ]
1147                         then
1148                                 continue
1149                         fi
1150                         if [ ! -d "${dest}" ]
1151                         then
1152                                 mkdir -p "${dest}"
1153                                 chown_ref "${src}" "${dest}"
1154                                 chmod_ref "${src}" "${dest}"
1155                         fi
1156                         link_files "${src}" "${dest}" "${src_transform}"
1157                 else
1158                         final_src=${src}
1159                         if [ -n "${src_transform}" ]
1160                         then
1161                                 final_src="$(echo ${final_src} | sed "${src_transform}")"
1162                         fi
1163                         rm -rf "${dest}" 2> /dev/null
1164                         ln -s "${final_src}" "${dest}"
1165                         chown_ref "${src}" "${dest}"
1166                 fi
1167         done
1168 }
1169
1170 do_union ()
1171 {
1172         local unionmountpoint unionrw unionro
1173         unionmountpoint="${1}"  # directory where the union is mounted
1174         shift
1175         unionrw="${1}"          # branch where the union changes are stored
1176         shift
1177         unionro="${*}"          # space separated list of read-only branches (optional)
1178
1179         case "${UNIONTYPE}" in
1180                 aufs)
1181                         rw_opt="rw"
1182                         ro_opt="rr+wh"
1183                         noxino_opt="noxino"
1184                         ;;
1185
1186                 unionfs-fuse)
1187                         rw_opt="RW"
1188                         ro_opt="RO"
1189                         ;;
1190
1191                 *)
1192                         rw_opt="rw"
1193                         ro_opt="ro"
1194                         ;;
1195         esac
1196
1197         case "${UNIONTYPE}" in
1198                 unionfs-fuse)
1199                         unionmountopts="-o cow -o noinitgroups -o default_permissions -o allow_other -o use_ino -o suid"
1200                         unionmountopts="${unionmountopts} ${unionrw}=${rw_opt}"
1201                         if [ -n "${unionro}" ]
1202                         then
1203                                 for rofs in ${unionro}
1204                                 do
1205                                         unionmountopts="${unionmountopts}:${rofs}=${ro_opt}"
1206                                 done
1207                         fi
1208                         ( sysctl -w fs.file-max=391524 ; ulimit -HSn 16384
1209                         unionfs-fuse ${unionmountopts} "${unionmountpoint}" ) && \
1210                         ( mkdir -p /run/sendsigs.omit.d
1211                         pidof unionfs-fuse >> /run/sendsigs.omit.d/unionfs-fuse || true )
1212                         ;;
1213
1214                 overlayfs)
1215                         # XXX: can multiple unionro be used? (overlayfs only handles two dirs, but perhaps they can be chained?)
1216                         # XXX: and can unionro be optional? i.e. can overlayfs skip lowerdir?
1217                         if echo ${unionro} | grep -q " "
1218                         then
1219                                 panic "Multiple lower filesystems are currently not supported with overlayfs (unionro = ${unionro})."
1220                         elif [ -z "${unionro}"  ]
1221                         then
1222                                 panic "Overlayfs needs at least one lower filesystem (read-only branch)."
1223                         fi
1224                         unionmountopts="-o noatime,lowerdir=${unionro},upperdir=${unionrw}"
1225                         mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
1226                         ;;
1227
1228                 *)
1229                         unionmountopts="-o noatime,${noxino_opt},dirs=${unionrw}=${rw_opt}"
1230                         if [ -n "${unionro}" ]
1231                         then
1232                                 for rofs in ${unionro}
1233                                 do
1234                                         unionmountopts="${unionmountopts}:${rofs}=${ro_opt}"
1235                                 done
1236                         fi
1237                         mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
1238                         ;;
1239         esac
1240 }
1241
1242 get_custom_mounts ()
1243 {
1244         # Side-effect: leaves $devices with persistence.conf mounted in /live/persistence
1245         # Side-effect: prints info to file $custom_mounts
1246
1247         local custom_mounts devices bindings links
1248         custom_mounts=${1}
1249         shift
1250         devices=${@}
1251
1252         bindings="/tmp/bindings.list"
1253         links="/tmp/links.list"
1254         rm -rf ${bindings} ${links} 2> /dev/null
1255
1256         for device in ${devices}
1257         do
1258                 local device_name backing include_list
1259                 device_name="$(basename ${device})"
1260                 backing=$(mount_persistence_media ${device})
1261                 if [ -z "${backing}" ]
1262                 then
1263                         continue
1264                 fi
1265
1266                 if [ -r "${backing}/${persistence_list}" ]
1267                 then
1268                         include_list="${backing}/${persistence_list}"
1269                 else
1270                         continue
1271                 fi
1272
1273                 if [ -n "${LIVE_BOOT_DEBUG}" ] && [ -e "${include_list}" ]
1274                 then
1275                         cp ${include_list} /live/persistence/${persistence_list}.${device_name}
1276                 fi
1277
1278                 while read dir options # < ${include_list}
1279                 do
1280                         if echo ${dir} | grep -qe "^[[:space:]]*\(#.*\)\?$"
1281                         then
1282                                 # skipping empty or commented lines
1283                                 continue
1284                         fi
1285
1286                         if trim_path ${dir} | grep -q -e "^[^/]" -e "^/lib" -e "^/lib/live\(/.*\)\?$" -e "^/\(.*/\)\?\.\.\?\(/.*\)\?$"
1287                         then
1288                                 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."
1289                                 continue
1290                         fi
1291
1292                         local opt_source opt_link source full_source full_dest
1293                         opt_source=""
1294                         opt_link=""
1295                         for opt in $(echo ${options} | tr ',' ' ');
1296                         do
1297                                 case "${opt}" in
1298                                         source=*)
1299                                                 opt_source=${opt#source=}
1300                                                 ;;
1301                                         link)
1302                                                 opt_link="true"
1303                                                 ;;
1304                                         union|bind)
1305                                                 ;;
1306                                         *)
1307                                                 log_warning_msg "Skipping custom mount with unkown option: ${opt}"
1308                                                 continue 2
1309                                                 ;;
1310                                 esac
1311                         done
1312
1313                         source="${dir}"
1314                         if [ -n "${opt_source}" ]
1315                         then
1316                                 if echo ${opt_source} | grep -q -e "^/" -e "^\(.*/\)\?\.\.\?\(/.*\)\?$" && [ "${opt_source}" != "." ]
1317                                 then
1318                                         log_warning_msg "Skipping unsafe custom mount with option source=${opt_source}: must be either \".\" (the media root) or a relative path w.r.t. the media root that contains neither comas, nor the special \".\" and \"..\" path components"
1319                                         continue
1320                                 else
1321                                         source="${opt_source}"
1322                                 fi
1323                         fi
1324
1325                         full_source="$(trim_path ${backing}/${source})"
1326                         full_dest="$(trim_path ${rootmnt}/${dir})"
1327                         if [ -n "${opt_link}" ]
1328                         then
1329                                 echo "${device} ${full_source} ${full_dest} ${options}" >> ${links}
1330                         else
1331                                 echo "${device} ${full_source} ${full_dest} ${options}" >> ${bindings}
1332                         fi
1333                 done < ${include_list}
1334         done
1335
1336         # We sort the list according to destination so we're sure that
1337         # we won't hide a previous mount. We also ignore duplicate
1338         # destinations in a more or less arbitrary way.
1339         [ -e "${bindings}" ] && sort -k3 -sbu ${bindings} >> ${custom_mounts} && rm ${bindings}
1340
1341         # After all mounts are considered we add symlinks so they
1342         # won't be hidden by some mount.
1343         [ -e "${links}" ] && cat ${links} >> ${custom_mounts} && rm ${links}
1344
1345         # We need to make sure that no two custom mounts have the same sources
1346         # or are nested; if that is the case, too much weird stuff can happen.
1347         local prev_source prev_dest
1348         prev_source="impossible source" # first iteration must not match
1349         prev_dest=""
1350         # This sort will ensure that a source /a comes right before a source
1351         # /a/b so we only need to look at the previous source
1352         sort -k2 -b ${custom_mounts} |
1353         while read device source dest options
1354         do
1355                 if echo ${source} | grep -qe "^${prev_source}\(/.*\)\?$"
1356                 then
1357                         panic "Two persistence mounts have the same or nested sources: ${source} on ${dest}, and ${prev_source} on ${prev_dest}"
1358                 fi
1359                 prev_source=${source}
1360                 prev_dest=${dest}
1361         done
1362 }
1363
1364 activate_custom_mounts ()
1365 {
1366         local custom_mounts used_devices
1367         custom_mounts="${1}" # the ouput from get_custom_mounts()
1368         used_devices=""
1369
1370         while read device source dest options # < ${custom_mounts}
1371         do
1372                 local opt_bind opt_link opt_union
1373                 opt_bind="true"
1374                 opt_link=""
1375                 opt_union=""
1376                 for opt in $(echo ${options} | tr ',' ' ');
1377                 do
1378                         case "${opt}" in
1379                                 bind)
1380                                         opt_bind="true"
1381                                         unset opt_link opt_union
1382                                         ;;
1383                                 link)
1384                                         opt_link="true"
1385                                         unset opt_bind opt_union
1386                                         ;;
1387                                 union)
1388                                         opt_union="true"
1389                                         unset opt_bind opt_link
1390                                         ;;
1391                         esac
1392                 done
1393
1394                 if [ -n "$(what_is_mounted_on "${dest}")" ]
1395                 then
1396                         if [ "${dest}" = "${rootmnt}" ]
1397                         then
1398                                 umount "${dest}"
1399                         else
1400                                 log_warning_msg "Skipping custom mount ${dest}: $(what_is_mounted_on "${dest}") is already mounted there"
1401                                 continue
1402                         fi
1403                 fi
1404
1405                 if [ ! -d "${dest}" ]
1406                 then
1407                         # create the destination and delete existing files in
1408                         # its path that are in the way
1409                         path="/"
1410                         for dir in $(echo ${dest} | sed -e 's|/\+| |g')
1411                         do
1412                                 path=$(trim_path ${path}/${dir})
1413                                 if [ -f ${path} ]
1414                                 then
1415                                         rm -f ${path}
1416                                 fi
1417                                 if [ ! -e ${path} ]
1418                                 then
1419                                         mkdir -p ${path}
1420                                         if echo ${path} | grep -qe "^${rootmnt}/*home/[^/]\+"
1421                                         then
1422                                                 # if ${dest} is in /home try fixing proper ownership by assuming that the intended user is the first, which is usually the case
1423                                                 # FIXME: this should really be handled by live-config since we don't know for sure which uid a certain user has until then
1424                                                 chown 1000:1000 ${path}
1425                                         fi
1426                                 fi
1427                         done
1428                 fi
1429
1430                 # if ${source} doesn't exist on our persistence media
1431                 # we bootstrap it with $dest from the live filesystem.
1432                 # this both makes sense and is critical if we're
1433                 # dealing with /etc or other system dir.
1434                 if [ ! -d "${source}" ]
1435                 then
1436                         if [ -n "${PERSISTENCE_READONLY}" ]
1437                         then
1438                                 continue
1439                         elif [ -n "${opt_union}" ] || [ -n "${opt_link}" ]
1440                         then
1441                                 # unions and don't need to be bootstrapped
1442                                 # link dirs can't be bootstrapped in a sensible way
1443                                 mkdir -p "${source}"
1444                                 chown_ref "${dest}" "${source}"
1445                                 chmod_ref "${dest}" "${source}"
1446                         elif [ -n "${opt_bind}" ]
1447                         then
1448                                 # ensure that $dest is not copied *into* $source
1449                                 mkdir -p "$(dirname ${source})"
1450                                 cp -a "${dest}" "${source}"
1451                         fi
1452                 fi
1453
1454                 # XXX: If CONFIG_AUFS_ROBR is added to the Debian kernel we can
1455                 # ignore the loop below and set rootfs_dest_backing=$dest
1456                 local rootfs_dest_backing
1457                 rootfs_dest_backing=""
1458                 if [ -n "${opt_link}" ] || [ -n "${opt_union}" ]
1459                 then
1460                         for d in /live/rootfs/*
1461                         do
1462                                 if [ -n "${rootmnt}" ]
1463                                 then
1464                                         fs="${d}/$(echo ${dest} | sed -e "s|${rootmnt}||")"
1465                                 else
1466                                         fs="${d}/${dest}"
1467                                 fi
1468                                 if [ -d "${fs}" ]
1469                                 then
1470                                         rootfs_dest_backing="${rootfs_dest_backing} ${fs}"
1471                                 fi
1472                         done
1473                 fi
1474
1475                 local cow_dir links_source
1476                 if [ -n "${opt_link}" ] && [ -z "${PERSISTENCE_READONLY}" ]
1477                 then
1478                         link_files ${source} ${dest} "s|^/live/|/lib/live/mount/|"
1479                 elif [ -n "${opt_link}" ] && [ -n "${PERSISTENCE_READONLY}" ]
1480                 then
1481                         mkdir -p ${rootmnt}/lib/live/mount/persistence
1482                         links_source=$(mktemp -d ${rootmnt}/lib/live/mount/persistence/links-source-XXXXXX)
1483                         chown_ref ${source} ${links_source}
1484                         chmod_ref ${source} ${links_source}
1485                         # We put the cow dir in the below strange place to
1486                         # make it absolutely certain that the link source
1487                         # has its own directory and isn't nested with some
1488                         # other custom mount (if so that mount's files would
1489                         # be linked, causing breakage.
1490                         cow_dir="/live/overlay/lib/live/mount/persistence/$(basename ${links_source})"
1491                         mkdir -p ${cow_dir}
1492                         chown_ref "${source}" "${cow_dir}"
1493                         chmod_ref "${source}" "${cow_dir}"
1494                         do_union ${links_source} ${cow_dir} ${source} ${rootfs_dest_backing}
1495                         link_files ${links_source} ${dest} "s|^${rootmnt}||"
1496                 elif [ -n "${opt_union}" ] && [ -z "${PERSISTENCE_READONLY}" ]
1497                 then
1498                         do_union ${dest} ${source} ${rootfs_dest_backing}
1499                 elif [ -n "${opt_bind}" ] && [ -z "${PERSISTENCE_READONLY}" ]
1500                 then
1501                         mount --bind "${source}" "${dest}"
1502                 elif [ -n "${opt_bind}" -o -n "${opt_union}" ] && [ -n "${PERSISTENCE_READONLY}" ]
1503                 then
1504                         # bind-mount and union mount are handled the same
1505                         # in read-only mode, but note that rootfs_dest_backing
1506                         # is non-empty (and necessary) only for unions
1507                         cow_dir="/live/overlay/${dest}"
1508                         if [ -e "${cow_dir}" ] && [ -z "${opt_link}" ]
1509                         then
1510                                 # If an earlier custom mount has files here
1511                                 # it will "block" the current mount's files
1512                                 # which is undesirable
1513                                 rm -rf "${cow_dir}"
1514                         fi
1515                         mkdir -p ${cow_dir}
1516                         chown_ref "${source}" "${cow_dir}"
1517                         chmod_ref "${source}" "${cow_dir}"
1518                         do_union ${dest} ${cow_dir} ${source} ${rootfs_dest_backing}
1519                 fi
1520
1521                 PERSISTENCE_IS_ON="1"
1522                 export PERSISTENCE_IS_ON
1523
1524                 if echo ${used_devices} | grep -qve "^\(.* \)\?${device}\( .*\)\?$"
1525                 then
1526                         used_devices="${used_devices} ${device}"
1527                 fi
1528         done < ${custom_mounts}
1529
1530         echo ${used_devices}
1531 }
1532
1533 is_mountpoint ()
1534 {
1535         directory="$1"
1536
1537         [ $(stat -fc%d:%D "${directory}") != $(stat -fc%d:%D "${directory}/..") ]
1538 }