buildlab: make work in vservers

buildlab.in

@@ -54,6 +54,37 @@ runpart() {
         $part || die "$part failed"
 }
 
+is_vserver() {
+	egrep -q '^VxID:[[:space:]]*[0-9]+' /proc/self/status
+}
+
+do_chroot_open() {
+	local path="$1"
+	if is_vserver; then
+		# vserver does not allow us mount or create devices
+		# but we can create hard links as long as chroot is
+		# on same filesystem as real root
+		rmdir "$path"/proc "$path"/sys "$path"/dev 2>/dev/null
+		ln /dev "$path"/dev
+		ln /proc "$path"/proc
+		ln /sys "$path"/sys
+
+	else
+		mkdir -p "$path"/dev "$path"/proc "$path"/sys
+		mount -o bind /dev "$path"/dev || return 1
+		mount -o bind /proc "$path"/proc
+		mount -o bind /sys "$path"/sys
+	fi
+}
+
+do_chroot_close() {
+	local path="$1"
+	if is_vserver; then
+		rmdir  "$path"/dev "$path"/proc "$path"/sys
+	else
+		umount "$path"/dev "$path"/proc "$path"/sys
+	fi
+}
 
 do_chroot_action() {
 	local path="$1"
@@ -61,10 +92,7 @@ do_chroot_action() {
 
 	msg "Doing chroot action '$command' in '$path'..."
 
-	mount -o bind /dev "$path"/dev
-	mount -o bind /proc "$path"/proc
-	mount -o bind /sys "$path"/sys
-
+	do_chroot_open "$path" || return 1
 	shift;
 
 	# XXX: we have to do this because busybox clobbers us, bleah.
@@ -72,9 +100,7 @@ do_chroot_action() {
 	chroot "$path" /bin/sh /.chroot-action.sh
 	rm "$path"/.chroot-action.sh
 
-	umount "$path"/dev
-	umount "$path"/proc
-	umount "$path"/sys
+	do_chroot_close
 }
 
 update_chroot() {