Power: Recovery on multipath volume fails due to get_sysfs_name checks volume path with ! included

[abbbi]

• rear version (/usr/sbin/rear -V): 2.1
• OS version (SLES):
• Are you using legacy BIOS or UEFI boot? UEFI
• Brief description of the issue:

hi there,

we are testing an environment with Power8. The system in this case boots from SAN directly (multipath setup). We disabled the autoexclude option for SAN volumes and enabled the BOOT_FROM_SAN option in default.conf, disklayout.conf looks ok.

During recovery the SAN volumes appear on the system:

RESCUE rescueme:/dev/mapper # ls -la
[..]
lrwxrwxrwx 1 root root 8 Jul 6 2017 mpathas -> ../dm-11

but rear fails in layout/prepare/default/250_compare_disks.sh as it searches for a
device called mapper!mpathas ..

• source /usr/share/rear/layout/prepare/default/250_compare_disks.sh
  ++ LogPrint 'Comparing disks.'
  ++ Log 'Comparing disks.'
  ++ test 1 -gt 0
  +++ Stamp
  +++ date '+%Y-%m-%d %H:%M:%S.%N '
  ++ echo '1970-01-01 01:10:09.895725408 Comparing disks.'
  1970-01-01 01:10:09.895725408 Comparing disks.
  ++ Print 'Comparing disks.'
  ++ test 1
  ++ echo -e 'Comparing disks.'
  ++ MIGRATION_MODE=
  ++ read disk dev size junk
  +++ grep -E '^disk |^multipath ' /var/lib/rear/layout/disklayout.conf
  +++ get_sysfs_name /dev/mapper/mpathas
  +++ local name=mapper/mpathas
  +++ name=mapper/mpathas
  +++ [[ -e /sys/block/mapper!mpathas ]]
  +++ [[ -h /dev/mapper/mpathas ]]
  ++++ readlink -f /dev/mapper/mpathas
  +++ local target=/dev/dm-11
  +++ [[ -e /sys/block/dm-11 ]]
  ++++ dmsetup info -c --noheadings -o major,minor mpathas
  +++ local dev_number=
  +++ [[ -n '' ]]
  +++ echo 'mapper!mpathas'
  +++ return 1
  ++ dev='mapper!mpathas'
  ++ Log 'Looking for mapper!mpathas...'
  ++ test 1 -gt 0
  +++ Stamp
  +++ date '+%Y-%m-%d %H:%M:%S.%N '
  ++ echo '1970-01-01 01:10:09.900414477 Looking for mapper!mpathas...'
  1970-01-01 01:10:09.900414477 Looking for mapper!mpathas...
  ++ '[' -e '/sys/block/mapper!mpathas' ']'
  ++ LogPrint 'Device mapper!mpathas does not exist.'
  ++ Log 'Device mapper!mpathas does not exist.'
  ++ test 1 -gt 0

i think the ! comes from usr/share/rear/lib/layout-functions.sh:415:
replacing / to ! (for some reason i do not understand):

if [[ -e /sys/block/${name////!} ]] ; then

[abbbi]

close. further investigation has brought up more problems that are leading to the devices not appearing.