diff -Nru sysvinit-2.87dsf/debian/changelog sysvinit-2.87dsf/debian/changelog
--- sysvinit-2.87dsf/debian/changelog	2010-10-29 04:31:02.000000000 +0100
+++ sysvinit-2.87dsf/debian/changelog	2011-01-28 17:34:18.000000000 +0000
@@ -1,3 +1,11 @@
+sysvinit (2.87dsf-4ubuntu20) natty; urgency=low
+
+  * debian/initscripts/etc/init.d/umountroot: Improve handling of
+    respawn of init: we now wait for inits map file to change. If this
+    doesn't happen within 5 seconds, we unmount forcibly.
+
+ -- James Hunt <james.hunt@ubuntu.com>  Fri, 28 Jan 2011 17:33:29 +0000
+
 sysvinit (2.87dsf-4ubuntu19) maverick-proposed; urgency=low
 
   * debian/initscripts.postinst (LP: #659738):
diff -Nru sysvinit-2.87dsf/debian/patches/99_improve-init-reexec-handling.dpatch sysvinit-2.87dsf/debian/patches/99_improve-init-reexec-handling.dpatch
--- sysvinit-2.87dsf/debian/patches/99_improve-init-reexec-handling.dpatch	1970-01-01 01:00:00.000000000 +0100
+++ sysvinit-2.87dsf/debian/patches/99_improve-init-reexec-handling.dpatch	2011-01-28 17:34:50.000000000 +0000
@@ -0,0 +1,41 @@
+Index: sysvinit-2.87dsf/debian/initscripts/etc/init.d/umountroot
+===================================================================
+--- sysvinit-2.87dsf.orig/debian/initscripts/etc/init.d/umountroot	2011-01-28 15:42:13.234543001 +0000
++++ sysvinit-2.87dsf/debian/initscripts/etc/init.d/umountroot	2011-01-28 15:43:15.398542998 +0000
+@@ -28,10 +28,33 @@
+ 	    ln -nsf /var/run /lib/init/rw
+ 	fi
+ 
+-	# Ask init to reexec itself before we go down if it has been
++	# Ask init to re-exec itself before we go down if it has been
+ 	# upgraded this cycle.  It'll lose all its state, but at least
+-	# it won't hold open files on the root filesystem
+-	[ -f /var/run/init.upgraded ] && telinit u || :
++	# it won't hold open files on the root filesystem (lp:#672177).
++	if [ -f /var/run/init.upgraded ]
++	then
++		old_map=$( cat /proc/1/maps )
++		map=$old_map
++		telinit u || :
++		i=0
++		timeout=5
++		while [ "$map" = "$old_map" ]
++		do
++			sleep 1
++			map=$( cat /proc/1/maps )
++			/usr/bin/logger "waiting for init to respawn"
++			i=$((i+1))
++			if [ $i -eq $timeout ] ; then
++				break
++			fi
++		done
++
++		if [ "$map" = "$old_map" ] ; then
++			/usr/bin/logger "FAIL: init failed to respawn in $timeout seconds - unmounting anyway"
++		else
++			/usr/bin/logger "SUCCESS: init respawned after $i seconds (within $timeout seconds timeout)"
++		fi
++	fi
+ 
+ 	MOUNT_FORCE_OPT=
+ 	[ "$(uname -s)" = "GNU/kFreeBSD" ] && MOUNT_FORCE_OPT=-f
diff -Nru sysvinit-2.87dsf/debian/patches/series sysvinit-2.87dsf/debian/patches/series
--- sysvinit-2.87dsf/debian/patches/series	2010-09-06 17:56:59.000000000 +0100
+++ sysvinit-2.87dsf/debian/patches/series	2011-01-28 15:42:06.000000000 +0000
@@ -1,3 +1,4 @@
+99_improve-init-reexec-handling.dpatch
 10_doc_manuals.dpatch
 11_doc_shutdown-c.dpatch
 14_doc_fsf_addr.dpatch