[PATCH] fix invalid frontend path for set_mtu

[James Dingwall <james-xen@xxxxxxxxxxxxxx>]

Hi,

The set_mtu() function of xen-network-common.sh currently has this code:

        if [ ${type_if} = vif ]
        then
            local dev_=${dev#vif}
            local domid=${dev_%.*}
            local devid=${dev_#*.}

            local FRONTEND_PATH="/local/domain/$domid/device/vif/$devid"

            xenstore_write "$FRONTEND_PATH/mtu" ${mtu}
        fi

This works fine if the device has its default name but if the xen config
defines the vifname parameter the FRONTEND_PATH is incorrectly constructed.
Learn the frontend path by reading the appropriate value from the backend.

diff --git a/tools/hotplug/Linux/xen-network-common.sh 
b/tools/hotplug/Linux/xen-network-common.sh
index 02e2388600..cd98f0d486 100644
--- a/tools/hotplug/Linux/xen-network-common.sh
+++ b/tools/hotplug/Linux/xen-network-common.sh
@@ -163,11 +163,7 @@ set_mtu () {
 
         if [ ${type_if} = vif ]
         then
-            local dev_=${dev#vif}
-            local domid=${dev_%.*}
-            local devid=${dev_#*.}
-
-            local FRONTEND_PATH="/local/domain/$domid/device/vif/$devid"
+            local FRONTEND_PATH=$(xenstore_read "$XENBUS_PATH/frontend")
 
             xenstore_write "$FRONTEND_PATH/mtu" ${mtu}
         fi



Thanks,
James