Mount and unmount /dev recursively, to cope with setups where there are

interesting bind-mounts under /dev (e.g. loop devices bind-mounted by
LXD).  LP: #1716465.

debian/changelog

@@ -1,3 +1,12 @@
+livecd-rootfs (2.441.5) UNRELEASED; urgency=medium
+
+  [ Colin Watson ]
+  * Mount and unmount /dev recursively, to cope with setups where there are
+    interesting bind-mounts under /dev (e.g. loop devices bind-mounted by
+    LXD).  LP: #1716465.
+
+ -- Steve Langasek <steve.langasek@ubuntu.com>  Mon, 11 Sep 2017 11:47:53 -0700
+
 livecd-rootfs (2.441.4) zesty; urgency=medium
 
   [ Balint Reczey ]

live-build/functions

@@ -82,8 +82,7 @@ mount_image() {
 setup_mountpoint() {
     local mountpoint="$1"
 
-    mount --bind /dev "$mountpoint/dev"
-    mount devpts-live -t proc "$mountpoint/dev/pts"
+    mount --rbind /dev "$mountpoint/dev"
     mount proc-live -t proc "$mountpoint/proc"
     mount sysfs-live -t sysfs "$mountpoint/sys"
     mount -t tmpfs none "$mountpoint/tmp"
@@ -144,11 +143,7 @@ umount_settle() {
 umount_partition() {
     local mountpoint=${1}
     mv resolv.conf.tmp "$mountpoint/etc/resolv.conf"
-    for submnt in proc sys dev/pts dev tmp;
-    do
-        umount $mountpoint/$submnt
-    done
-    umount $mountpoint
+    umount -R $mountpoint
     udevadm settle
 
     if [ -n "${rootfs_dev_mapper}" -a -b "${rootfs_dev_mapper}" ]; then

live-build/ubuntu-cpc/hooks/032-root-squashfs.binary

@@ -39,8 +39,7 @@ chroot binary/boot/squashfs.dir dpkg-divert --remove --local --rename /usr/sbin/
 mv resolv.conf.tmp "binary/boot/squashfs.dir/etc/resolv.conf"
 umount "binary/boot/squashfs.dir/proc"
 umount "binary/boot/squashfs.dir/sys"
-umount "binary/boot/squashfs.dir/dev/pts"
-umount "binary/boot/squashfs.dir/dev"
+umount -R "binary/boot/squashfs.dir/dev"
 umount "binary/boot/squashfs.dir/tmp"
 
 apt-get -qqy install squashfs-tools

live-build/ubuntu-server/hooks/032-installer-squashfs.binary

@@ -155,8 +155,7 @@ umount "$SQUASH_ROOT"
 # Then we can start unmounting the "real" root:
 umount "binary/boot/squashfs.dir/proc"
 umount "binary/boot/squashfs.dir/sys"
-umount "binary/boot/squashfs.dir/dev/pts"
-umount "binary/boot/squashfs.dir/dev"
+umount -R "binary/boot/squashfs.dir/dev"
 umount "binary/boot/squashfs.dir/tmp"
 
 apt-get -qqy install squashfs-tools