diff -Nru cryptsetup-1.6.6/debian/changelog cryptsetup-1.6.6/debian/changelog
--- cryptsetup-1.6.6/debian/changelog	2015-08-21 03:59:11.000000000 -0400
+++ cryptsetup-1.6.6/debian/changelog	2015-12-16 19:17:59.000000000 -0500
@@ -1,3 +1,23 @@
+cryptsetup (2:1.6.6-5ubuntu2+bug1481536.3~15.10.1) wily; urgency=medium
+
+  [ Steve Langasek ]
+  * debian/initramfs/cryptroot-script: don't call vgchange, which udev rules
+    already handle for us.  Instead we should be calling udevadm settle at
+    the right points to ensure devices are visible before we try to use
+    them.  Thanks to Richard Hansen for the analysis.  LP: #1481536.
+
+  [ Richard Hansen ]
+  * debian/initramfs/cryptroot-script:
+    - don't assume devices will exist after running 'udevadm settle'
+      (wait until they appear, with a timeout)
+    - wait for the LVM logical volume device to appear before trying
+      to determine its filesystem type
+    - remove an unnecessary call to udev_settle()
+    - miscellaneous cleanups
+    LP: #1481536
+
+ -- Richard Hansen <rhansen@rhansen.org>  Wed, 16 Dec 2015 15:49:33 -0500
+
 cryptsetup (2:1.6.6-5ubuntu2) wily; urgency=medium
 
   * Fix stupid typo in Recommends "busybox | busybox-static" inversion.
diff -Nru cryptsetup-1.6.6/debian/initramfs/cryptroot-script cryptsetup-1.6.6/debian/initramfs/cryptroot-script
--- cryptsetup-1.6.6/debian/initramfs/cryptroot-script	2015-03-28 16:38:34.000000000 -0400
+++ cryptsetup-1.6.6/debian/initramfs/cryptroot-script	2015-12-16 19:15:13.000000000 -0500
@@ -155,18 +155,44 @@
 	return 0
 }
 
-activate_vg()
+# arg #1:  device to wait for
+# arg #2 (optional):  description of what we're waiting for, defaults to $1
+wait_for()
 {
-	# Sanity checks
-	if [ ! -x /sbin/lvm ]; then
-		message "cryptsetup: lvm is not available"
-		return 1
-	fi
+	if [ ! -e "$1" ]; then
+		log_begin_msg "Waiting for ${2-$1}..."
+
+		# Default delay is 180s
+		slumber=${ROOTDELAY:-180}
+
+		slumber=$(( ${slumber} * 10 ))
+		while [ ! -e "$1" ]; do
+			# Each call to udev_settle can block for up to 30
+			# seconds, so the worst case scenario here is a boot
+			# delay of $ROOTDELAY*10*30 seconds = 15 hours.
+			# However, this could only ever happen if udev
+			# constantly had new events being queued *and* none of
+			# these events resulted in the root device becoming
+			# available.  Still, a more correct solution would
+			# measure against wall time and call udevadm settle
+			# in a loop until the $ROOTDELAY timeout has been
+			# reached.
+			udev_settle
+
+			/bin/sleep 0.1
+			slumber=$(( ${slumber} - 1 ))
+			[ ${slumber} -gt 0 ] || break
+		done
 
-	# Detect and activate available volume groups
-	/sbin/lvm vgscan
-	/sbin/lvm vgchange -a y --sysinit
-	return $?
+		if [ ${slumber} -gt 0 ]; then
+			log_end_msg 0
+		else
+			log_end_msg 1 || true
+		fi
+	fi
+	# make sure the return value is true if the device exists,
+	# false otherwise
+	[ -e "$1" ]
 }
 
 setup_mapping()
@@ -199,49 +225,9 @@
 	modprobe -q dm_crypt
 
 	# Make sure the cryptsource device is available
-	if [ ! -e $cryptsource ]; then
-		activate_vg
-	fi
-
-	# If the encrypted source device hasn't shown up yet, give it a
-	# little while to deal with removable devices
-
-	# the following lines below have been taken from
-	# /usr/share/initramfs-tools/scripts/local, as suggested per
-	# https://launchpad.net/bugs/164044
-	if [ ! -e "$cryptsource" ]; then
-		log_begin_msg "Waiting for encrypted source device..."
-
-		# Default delay is 180s
-		if [ -z "${ROOTDELAY}" ]; then
-			slumber=180
-		else
-			slumber=${ROOTDELAY}
-		fi
-
-		slumber=$(( ${slumber} * 10 ))
-		while [ ! -e "$cryptsource" ]; do
-			# retry for LVM devices every 10 seconds
-			if [ ${slumber} -eq $(( ${slumber}/100*100 )) ]; then
-				activate_vg
-			fi
-
-			/bin/sleep 0.1
-			slumber=$(( ${slumber} - 1 ))
-			[ ${slumber} -gt 0 ] || break
-		done
-
-		if [ ${slumber} -gt 0 ]; then
-			log_end_msg 0
-		else
-			log_end_msg 1 || true
-		fi
- 	fi
-	udev_settle
-
-	# We've given up, but we'll let the user fix matters if they can
-	if [ ! -e "${cryptsource}" ]; then
-		
+	if ! wait_for "$cryptsource" "encrypted source device"; then
+		# We've given up, but we'll let the user fix matters
+		# if they can
 		echo "  ALERT! ${cryptsource} does not exist."
 		echo "	Check cryptopts=source= bootarg: cat /proc/cmdline"
 		echo "	or missing modules, devices: cat /proc/modules; ls /dev"
@@ -271,93 +257,82 @@
 	cryptremove="/sbin/cryptsetup remove $crypttarget"
 	NEWROOT="/dev/mapper/$crypttarget"
 
+	if [ -z "$cryptkeyscript" ]; then
+		if [ ${cryptsource#/dev/disk/by-uuid/} != $cryptsource ]; then
+			# UUIDs are not very helpful
+			diskname="$crypttarget"
+		else
+			diskname="$cryptsource ($crypttarget)"
+		fi
+
+		if [ -x /bin/plymouth ] && plymouth --ping; then
+			cryptkeyscript="plymouth ask-for-password --prompt"
+			# Plymouth will add a : if it is a non-graphical prompt
+			cryptkey="Please unlock disk $diskname"
+		else
+			cryptkeyscript="/lib/cryptsetup/askpass"
+			cryptkey="Please unlock disk $diskname: "
+		fi
+	fi
+
 	# Try to get a satisfactory password $crypttries times
 	count=0
-	while [ $crypttries -le 0 ] || [ $count -lt $crypttries ]; do
+	export CRYPTTAB_TRIED="$count"
+	while [ ! -e "$NEWROOT" ]; do
 		export CRYPTTAB_TRIED="$count"
+		if [ $crypttries -gt 0 ] && [ $count -ge $crypttries ]; then
+			message "cryptsetup: maximum number of tries exceeded for $crypttarget"
+			return 1
+		fi
 		count=$(( $count + 1 ))
 
-		if [ -z "$cryptkeyscript" ]; then
-			if [ ${cryptsource#/dev/disk/by-uuid/} != $cryptsource ]; then
-				# UUIDs are not very helpful
-				diskname="$crypttarget"
-			else
-				diskname="$cryptsource ($crypttarget)"
-			fi
-
-			if [ -x /bin/plymouth ] && plymouth --ping; then
-				cryptkeyscript="plymouth ask-for-password --prompt"
-				# Plymouth will add a : if it is a non-graphical prompt
-				cryptkey="Please unlock disk $diskname"
-			else
-				cryptkeyscript="/lib/cryptsetup/askpass"
-				cryptkey="Please unlock disk $diskname: "
-			fi
-		fi
+		crypttarget="$crypttarget" cryptsource="$cryptsource" \
+			$cryptkeyscript "$cryptkey" | $cryptopen && break
+		message "cryptsetup: cryptsetup failed, bad password or options?"
+	done
 
+	if ! wait_for "$NEWROOT" "unlocked device"; then
+		message "cryptsetup: unknown error setting up device mapping"
+		return 1
+	fi
 
-		if [ ! -e "$NEWROOT" ]; then
-			if ! crypttarget="$crypttarget" cryptsource="$cryptsource" \
-			     $cryptkeyscript "$cryptkey" | $cryptopen; then
-				message "cryptsetup: cryptsetup failed, bad password or options?"
-				continue
-			fi
-		fi
+	FSTYPE="$(/sbin/blkid -s TYPE -o value "$NEWROOT")"
 
-		if [ ! -e "$NEWROOT" ]; then
-			message "cryptsetup: unknown error setting up device mapping"
+	# See if we need to setup lvm on the crypto device
+	if [ "$FSTYPE" = "LVM_member" ] || [ "$FSTYPE" = "LVM2_member" ]; then
+		if [ -z "$cryptlvm" ]; then
+			message "cryptsetup: lvm fs found but no lvm configured"
 			return 1
 		fi
 
-		#FSTYPE=''
-		#eval $(fstype < "$NEWROOT")
-		FSTYPE="$(/sbin/blkid -s TYPE -o value "$NEWROOT")"
-
-		# See if we need to setup lvm on the crypto device
-		#if [ "$FSTYPE" = "lvm" ] || [ "$FSTYPE" = "lvm2" ]; then
-		if [ "$FSTYPE" = "LVM_member" ] || [ "$FSTYPE" = "LVM2_member" ]; then
-			if [ -z "$cryptlvm" ]; then
-				message "cryptsetup: lvm fs found but no lvm configured"
-				return 1
-			elif ! activate_vg; then
-				# disable error message, LP: #151532
-				#message "cryptsetup: failed to setup lvm device"
-				return 1
-			fi
-
-			# Apparently ROOT is already set in /conf/param.conf for
-			# flashed kernels at least. See bugreport #759720.
-			if [ -f /conf/param.conf ] && grep -q "^ROOT=" /conf/param.conf; then
-				NEWROOT=$(sed -n 's/^ROOT=//p' /conf/param.conf)
-			else
-				NEWROOT=${cmdline_root:-/dev/mapper/$cryptlvm}
-				if [ "$cryptrootdev" = "yes" ]; then
-					# required for lilo to find the root device
-					echo "ROOT=$NEWROOT" >>/conf/param.conf
-				fi
+		# Apparently ROOT is already set in /conf/param.conf for
+		# flashed kernels at least. See bugreport #759720.
+		if [ -f /conf/param.conf ] && grep -q "^ROOT=" /conf/param.conf; then
+			NEWROOT=$(sed -n 's/^ROOT=//p' /conf/param.conf)
+		else
+			NEWROOT=${cmdline_root:-/dev/mapper/$cryptlvm}
+			if [ "$cryptrootdev" = "yes" ]; then
+				# required for lilo to find the root device
+				echo "ROOT=$NEWROOT" >>/conf/param.conf
 			fi
-			#eval $(fstype < "$NEWROOT")
-			FSTYPE="$(/sbin/blkid -s TYPE -o value "$NEWROOT")"
 		fi
 
-		#if [ -z "$FSTYPE" ] || [ "$FSTYPE" = "unknown" ]; then
-		if [ -z "$FSTYPE" ]; then
-			message "cryptsetup: unknown fstype, bad password or options?"
-			udev_settle
+		if ! wait_for "$NEWROOT" "LVM logical volume"; then
+			message "cryptsetup: unknown error setting up LVM logical volume"
 			$cryptremove
-			continue
+			return 1
 		fi
 
-		message "cryptsetup: $crypttarget set up successfully"
-		break
-	done
+		FSTYPE="$(/sbin/blkid -s TYPE -o value "$NEWROOT")"
+	fi
 
-	if [ $crypttries -gt 0 ] && [ $count -gt $crypttries ]; then
-		message "cryptsetup: maximum number of tries exceeded for $crypttarget"
+	if [ -z "$FSTYPE" ]; then
+		message "cryptsetup: unknown fstype, bad password or options?"
+		$cryptremove
 		return 1
 	fi
 
-	udev_settle
+	message "cryptsetup: $crypttarget set up successfully"
 	return 0
 }