commit ef6d98b4f9d2f9400d00eaf3fe7ef82e3e428add
Author: Martin Wilck <mwilck@suse.com>
Date:   Mon Jun 25 21:47:23 2018 +0200

    libmultipath: allow distributions to change partition_delim default
    
    partition_delimiter is UNSET by default, falling back to the kernel
    default behavior to use "p" for devices ending in a digit, and ""
    for others. However, the udev rules for kpartx have always used the
    delimiter "-part". If a map name is changed (e.g. if an alias is
    reconfigured), multipathd first sets partition names e.g. to name "mpatha1",
    which is later changed to "mpatha-part1" by kpartx during udev rule
    processing. That's inefficient and superfluous. However, if a distribution
    simply changed DEFAULT_PARTITION_DELIM to "-part", users wouldn't be able
    to restore the default behavior any more.
    
    This patch allows to set 'partition_delimiter "/UNSET/"' in multipath.conf
    to force the previous default behavior, even if the distribution default is
    something other than UNSET. The string "/UNSET/" is not a valid partition
    delimiter because filenames can't contain slashes, thus user freedom isn't
    constrained by this patch.
    
    Signed-off-by: Martin Wilck <mwilck@suse.com>
