[PATCH 1 of 2] xencommons: run script only when needed

[Olaf Hering <olaf@aepfle.de>]

# HG changeset patch
# User Olaf Hering <olaf@aepfle.de>
# Date 1322228282 -3600
# Node ID bed3a6489d9a2ee2fdfc12a35f8544c7148dfe1a
# Parent  1027e7d13d02143048c7d48d7960967c5b1657a8
xencommons: run script only when needed

Currently xencommons prints an error that /proc/xen/capabilities does
not exist when started on a non-xen kernel.

Update the xencommons script to run only when needed:
- do not run if /proc/xen does not exist
- check if /proc/xen/capabilities exists before doing the grep for dom0

Signed-off-by: Olaf Hering <olaf@aepfle.de>

diff -r 1027e7d13d02 -r bed3a6489d9a tools/hotplug/Linux/init.d/xencommons
--- a/tools/hotplug/Linux/init.d/xencommons
+++ b/tools/hotplug/Linux/init.d/xencommons
@@ -29,15 +29,24 @@ test -f $xencommons_config/xencommons &&
 XENCONSOLED_PIDFILE=/var/run/xenconsoled.pid
 shopt -s extglob
 
+# not running in Xen dom0 or domU
+if ! test -d /proc/xen ; then
+	exit 0
+fi
+
+# mount xenfs in dom0 or domU with a pv_ops kernel
 if test "x$1" = xstart && \
-     test -d /proc/xen && \
    ! test -f /proc/xen/capabilities && \
    ! grep '^xenfs ' /proc/mounts >/dev/null;
 then
 	mount -t xenfs xenfs /proc/xen
 fi
 
-if ! grep -q "control_d" /proc/xen/capabilities ; then
+# run this script only in dom0:
+# no capabilities file in xenlinux domU kernel
+# empty capabilities file in pv_ops domU kernel
+if test -f /proc/xen/capabilities && \
+   ! grep -q "control_d" /proc/xen/capabilities ; then
 	exit 0
 fi