When checking CDL formatted DASD for installed dump-tool (zgetdump -d),
we might stumble upon an 'empty' boot record pointer in the volume label
filled with bytes of 0x40 (EBCDIC spaces). This leads to the following
seek error reported:
# zgetdump -d /dev/dasdb
zgetdump: Could not seek "/dev/dasdb" (Invalid argument)
Check for empty boot record and return proper error code by
ngdump_get_eckd_part_num() in order to end up with a regular
"No dump tool found" message.
Fixes: f3bcd94524 ("zdump: Add zgetdump -d support for ECKD ldipl-dump")
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>