Author: Michael Tokarev <mjt@tls.msk.ru>
Description: readlink is in /bin not /usr/bin on debian (Closes: #766416).
 This is a debian-specific change, upstream ships
 the rule to use /usr/bin/readlink while on debian
 it is /bin/readlink

diff -Naurp mdadm.orig/udev-md-raid-arrays.rules mdadm/udev-md-raid-arrays.rules
--- mdadm.orig/udev-md-raid-arrays.rules
+++ mdadm/udev-md-raid-arrays.rules
@@ -37,7 +37,7 @@ ENV{ID_FS_USAGE}=="filesystem|other", EN
 ENV{MD_LEVEL}=="raid[1-9]*", ENV{SYSTEMD_WANTS}+="mdmonitor.service"
 
 # Tell systemd to run mdmon for our container, if we need it.
-ENV{MD_LEVEL}=="raid[1-9]*", ENV{MD_CONTAINER}=="?*", PROGRAM="/usr/bin/readlink $env{MD_CONTAINER}", ENV{MD_MON_THIS}="%c"
+ENV{MD_LEVEL}=="raid[1-9]*", ENV{MD_CONTAINER}=="?*", PROGRAM="/bin/readlink $env{MD_CONTAINER}", ENV{MD_MON_THIS}="%c"
 ENV{MD_MON_THIS}=="?*", PROGRAM="/usr/bin/basename $env{MD_MON_THIS}", ENV{SYSTEMD_WANTS}+="mdmon@%c.service"
 ENV{RESHAPE_ACTIVE}=="yes", PROGRAM="/usr/bin/basename $env{MD_MON_THIS}", ENV{SYSTEMD_WANTS}+="mdadm-grow-continue@%c.service"