[PATCH] InterfaceManager: fix tc deconfiguration

[Ondrej Lichtner]

From: Ondrej Lichtner <olichtne(a)redhat.com&gt;

The recently added functionality of clearing tc configuration broke
recipes that already used netem functionality directly from the
configuration XML part. The problem was with trying to clear tc
configuration twice.

To fixed this I moved the new functions to be called after deconfigure()
takes care of it's own tc configuration. For this to work I also had to
add a check for interface existence since deconfigure() can remove the
device completely if NetworkManager is used.

Signed-off-by: Ondrej Lichtner <olichtne(a)redhat.com&gt;
---
 lnst/Slave/InterfaceManager.py | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/lnst/Slave/InterfaceManager.py b/lnst/Slave/InterfaceManager.py
index 05bd71e..452bd89 100644
--- a/lnst/Slave/InterfaceManager.py
+++ b/lnst/Slave/InterfaceManager.py
@@ -520,6 +520,13 @@ class Device(object):
         self._conf_dict = None
 
     def _clear_tc_qdisc(self):
+        try:
+            #checks device existence as it might have been removed by
+            #calling self.deconfigure()
+            exec_cmd("ip l show %s" % self._name, log_outputs=False)
+        except:
+            return
+
         exec_cmd("tc qdisc replace dev %s root pfifo" % self._name)
         out, _ = exec_cmd("tc filter show dev %s" % self._name)
         ingress_handles = re.findall("ingress (\\d+):", out)
@@ -532,6 +539,13 @@ class Device(object):
                 exec_cmd("tc qdisc del dev %s ingress" % self._name)
 
     def _clear_tc_filters(self):
+        try:
+            #checks device existence as it might have been removed by
+            #calling self.deconfigure()
+            exec_cmd("ip l show %s" % self._name, log_outputs=False)
+        except:
+            return
+
         out, _ = exec_cmd("tc filter show dev %s" % self._name)
         egress_prefs = re.findall("pref (\\d+) .* handle", out)
 
@@ -552,10 +566,10 @@ class Device(object):
                 m_dev.clear_configuration()
 
         if self._conf != None:
-            self._clear_tc_qdisc()
-            self._clear_tc_filters()
             self.down()
             self.deconfigure()
+            self._clear_tc_qdisc()
+            self._clear_tc_filters()
             self.destroy()
             self._conf = None
             self._conf_dict = None
-- 
2.9.3