Add qubes.ResizeDisk service to adjust filesystem size

Do this using qubes rpc service, instead of calling resize2fs directly
by dom0.

Makefile

@@ -237,6 +237,7 @@ install-common:
 	install -m 0644 qubes-rpc/qubes.GetImageRGBA $(DESTDIR)/etc/qubes-rpc
 	install -m 0644 qubes-rpc/qubes.SetDateTime $(DESTDIR)/etc/qubes-rpc
 	install -m 0755 qubes-rpc/qubes.InstallUpdatesGUI $(DESTDIR)/etc/qubes-rpc
+	install -m 0755 qubes-rpc/qubes.ResizeDisk $(DESTDIR)/etc/qubes-rpc
 
 	install -d $(DESTDIR)/etc/qubes/suspend-pre.d
 	install -m 0644 qubes-rpc/suspend-pre.README $(DESTDIR)/etc/qubes/suspend-pre.d/README

qubes-rpc/qubes.ResizeDisk

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+read disk_name
+
+set -e
+
+case $disk_name in
+    private)
+        # force some read to refresh device size
+        head /dev/xvdb > /dev/null
+        resize2fs /dev/xvdb
+        ;;
+    root)
+        # force some read to refresh device size
+        head /dev/xvda > /dev/null
+        new_size=$(cat /sys/block/xvda/size)
+        ro=$(/sys/block/xvda/ro)
+        if [ $ro -eq 1 ]; then
+            new_table="0 $new_size snapshot /dev/xvda /dev/xvdc2 N 16"
+        else
+            new_table="0 $new_size linear /dev/xvda 0"
+        fi
+        dmsetup load dmroot --table "$new_table"
+        dmsetup resume dmroot
+        resize2fs /dev/mapper/dmroot
+        ;;
+    *)
+        echo "Automatic resize of '$disk_name' not supported" >&2
+        exit 1
+        ;;
+esac
+

rpm_spec/core-vm.spec

@@ -350,6 +350,7 @@ rm -f %{name}-%{version}
 %config(noreplace) /etc/qubes-rpc/qubes.GetImageRGBA
 %config(noreplace) /etc/qubes-rpc/qubes.SetDateTime
 %config(noreplace) /etc/qubes-rpc/qubes.InstallUpdatesGUI
+%config(noreplace) /etc/qubes-rpc/qubes.ResizeDisk
 %dir /etc/qubes/autostart
 /etc/qubes/autostart/README.txt
 %config /etc/qubes/autostart/*.desktop.d/30_qubes.conf