Merge remote-tracking branch 'qubesos/pr/5'

* qubesos/pr/5:
  fix VM autostart race condition

Fixes qubesos/qubes-issues#1075

Conflicts:
	linux/aux-tools/prepare-volatile-img.sh

linux/aux-tools/prepare-volatile-img.sh

@@ -31,6 +31,8 @@ sfdisk --no-reread -u M "$FILENAME" > /dev/null 2> /dev/null <<EOF
 ,${ROOT_SIZE},L
 EOF
 
+(
+	flock 200
 	loopdev=`losetup -f --show --partscan "$FILENAME"`
 	udevadm settle
 	created=
@@ -48,3 +50,4 @@ if [ "$created" = "yes" ]; then
 	fi
 	losetup -d ${loopdev} || :
 	chown --reference `dirname "$FILENAME"` "$FILENAME"
+) 200>"/var/run/qubes/prepare-volatile-img.lock"