From 91428ebaa18c92c87dadf4c7341640fa77bcb0d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Fri, 21 Mar 2014 18:43:13 +0100
Subject: [PATCH] core: method to resize root.img (#699)

---
 core-modules/000QubesVm.py         |  1 +
 core-modules/01QubesHVm.py         | 18 ++++++++
 core-modules/02QubesTemplateHVm.py |  7 ++++
 qvm-tools/qvm-grow-root            | 67 ++++++++++++++++++++++++++++++
 4 files changed, 93 insertions(+)
 create mode 100755 qvm-tools/qvm-grow-root

diff --git a/core-modules/000QubesVm.py b/core-modules/000QubesVm.py
index 8b7c9072..a79f726d 100644
--- a/core-modules/000QubesVm.py
+++ b/core-modules/000QubesVm.py
@@ -778,6 +778,7 @@ class QubesVm(object):
             raise QubesException("resize2fs failed")
 
 
+
     # FIXME: should be outside of QubesVM?
     def get_timezone(self):
         # fc18
diff --git a/core-modules/01QubesHVm.py b/core-modules/01QubesHVm.py
index 6ef2cc59..dd6869d3 100644
--- a/core-modules/01QubesHVm.py
+++ b/core-modules/01QubesHVm.py
@@ -231,6 +231,24 @@ class QubesHVm(QubesVm):
         f_private.truncate (size)
         f_private.close ()
 
+    def resize_root_img(self, size):
+        if self.template:
+            raise QubesException("Cannot resize root.img of template-based VM"
+                                 ". Resize the root.img of the template "
+                                 "instead.")
+
+        if self.is_running():
+            raise QubesException("Cannot resize root.img of running HVM")
+
+        if size < self.get_root_img_sz():
+            raise QubesException(
+                "For your own safety shringing of root.img is disabled. If "
+                "you really know what you are doing, use 'truncate' manually.")
+
+        f_root = open (self.root_img, "a+b")
+        f_root.truncate (size)
+        f_root.close ()
+
     def get_rootdev(self, source_template=None):
         if self.template:
             return "'script:snapshot:{template_root}:{volatile},xvda,w',".format(
diff --git a/core-modules/02QubesTemplateHVm.py b/core-modules/02QubesTemplateHVm.py
index 455cf17f..e1ab1325 100644
--- a/core-modules/02QubesTemplateHVm.py
+++ b/core-modules/02QubesTemplateHVm.py
@@ -71,6 +71,13 @@ class QubesTemplateHVm(QubesHVm):
     def is_template_compatible(cls, template):
         return False
 
+    def resize_root_img(self, size):
+        for vm in self.appvms.values():
+            if vm.is_running():
+                raise QubesException("Cannot resize root.img while any VM "
+                                     "based on this tempate is running")
+        return super(QubesTemplateHVm, self).resize_root_img()
+
     def start(self, *args, **kwargs):
         for vm in self.appvms.values():
             if vm.is_running():
diff --git a/qvm-tools/qvm-grow-root b/qvm-tools/qvm-grow-root
new file mode 100755
index 00000000..36baa7c9
--- /dev/null
+++ b/qvm-tools/qvm-grow-root
@@ -0,0 +1,67 @@
+#!/usr/bin/python2
+#
+# The Qubes OS Project, http://www.qubes-os.org
+#
+# Copyright (C) 2014  Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+#
+
+from qubes.qubes import QubesVmCollection
+from qubes.qubes import QubesException
+from qubes.qubesutils import parse_size
+from optparse import OptionParser
+import subprocess
+import os
+import re
+import sys
+
+def main():
+    usage = "usage: %prog <vm-name> <size>"
+    parser = OptionParser (usage)
+
+    (options, args) = parser.parse_args ()
+    if (len (args) != 2):
+        parser.error ("You must specify VM name and new size!")
+    vmname = args[0]
+    size = args[1]
+
+    qvm_collection = QubesVmCollection()
+    qvm_collection.lock_db_for_reading()
+    qvm_collection.load()
+    qvm_collection.unlock_db()
+
+    vm = qvm_collection.get_vm_by_name(vmname)
+    if vm is None:
+        print >> sys.stderr, "A VM with the name '{0}' does not exist in the system.".format(vmname)
+        exit(1)
+
+    size_bytes = parse_size(size)
+
+    if not hasattr(vm, 'resize_root_img'):
+        print >> sys.stderr, "Operation not supported for this VM type"
+        exit(1)
+
+    try:
+        vm.resize_root_img(size_bytes)
+    except (IOError, OSError, QubesException) as err:
+        print >> sys.stderr, "ERROR: {0}".format(err)
+        exit (1)
+
+    exit (0)
+
+
+main()