From 0b84027204d94e7b314bce505e59aa0c336af43c Mon Sep 17 00:00:00 2001
From: Patrick East <patrick.east@purestorage.com>
Date: Tue, 14 Oct 2014 15:45:38 -0700
Subject: [PATCH] Multipath commands with error messages in stdout fail to
 parse
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

This change fixes an issue in find_multipath_device() where the command
output of ‘multipath -l <device>’ would sometimes fail to be parsed if
there were error messages in the stdout string in addition to the
expected output. We will now strip out the error messages before we
attempt to parse the lines.

Change-Id: I3d48debc7d64f6a891ac37d4c2c5ebddfb5b00b0
Closes-Bug: #1380742
---
 cinder/brick/initiator/linuxscsi.py        |  5 ++++
 cinder/tests/brick/test_brick_linuxscsi.py | 29 ++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/cinder/brick/initiator/linuxscsi.py b/cinder/brick/initiator/linuxscsi.py
index a374ce61f..1b3b87390 100644
--- a/cinder/brick/initiator/linuxscsi.py
+++ b/cinder/brick/initiator/linuxscsi.py
@@ -17,6 +17,7 @@
    Note, this is not iSCSI.
 """
 import os
+import re
 
 from cinder.brick import executor
 from cinder.i18n import _
@@ -25,6 +26,8 @@ from cinder.openstack.common import processutils as putils
 
 LOG = logging.getLogger(__name__)
 
+MULTIPATH_ERROR_REGEX = re.compile("\w{3} \d+ \d\d:\d\d:\d\d \|.*$")
+
 
 class LinuxSCSI(executor.Executor):
     def __init__(self, root_helper, execute=putils.execute,
@@ -143,6 +146,8 @@ class LinuxSCSI(executor.Executor):
         if out:
             lines = out.strip()
             lines = lines.split("\n")
+            lines = [line for line in lines
+                     if not re.match(MULTIPATH_ERROR_REGEX, line)]
             if lines:
                 line = lines[0]
                 info = line.split(" ")
diff --git a/cinder/tests/brick/test_brick_linuxscsi.py b/cinder/tests/brick/test_brick_linuxscsi.py
index 5dc46130e..fcea805a2 100644
--- a/cinder/tests/brick/test_brick_linuxscsi.py
+++ b/cinder/tests/brick/test_brick_linuxscsi.py
@@ -181,3 +181,32 @@ class LinuxSCSITestCase(test.TestCase):
         self.assertEqual("1", info['devices'][1]['channel'])
         self.assertEqual("0", info['devices'][1]['id'])
         self.assertEqual("3", info['devices'][1]['lun'])
+
+    def test_find_multipath_device_with_error(self):
+        def fake_execute(*cmd, **kwargs):
+            out = ("Oct 13 10:24:01 | /lib/udev/scsi_id exitted with 1\n"
+                   "36005076303ffc48e0000000000000101 dm-2 IBM,2107900\n"
+                   "size=1.0G features='1 queue_if_no_path' hwhandler='0'"
+                   " wp=rw\n"
+                   "`-+- policy='round-robin 0' prio=-1 status=active\n"
+                   "  |- 6:0:2:0  sdd 8:64  active undef  running\n"
+                   "  `- 6:1:0:3  sdc 8:32  active undef  running\n"
+                   )
+            return out, None
+
+        self.stubs.Set(self.linuxscsi, '_execute', fake_execute)
+
+        info = self.linuxscsi.find_multipath_device('/dev/sdd')
+        LOG.error("info = %s" % info)
+        self.assertEqual("/dev/dm-2", info["device"])
+        self.assertEqual("/dev/sdd", info['devices'][0]['device'])
+        self.assertEqual("6", info['devices'][0]['host'])
+        self.assertEqual("0", info['devices'][0]['channel'])
+        self.assertEqual("2", info['devices'][0]['id'])
+        self.assertEqual("0", info['devices'][0]['lun'])
+
+        self.assertEqual("/dev/sdc", info['devices'][1]['device'])
+        self.assertEqual("6", info['devices'][1]['host'])
+        self.assertEqual("1", info['devices'][1]['channel'])
+        self.assertEqual("0", info['devices'][1]['id'])
+        self.assertEqual("3", info['devices'][1]['lun'])
-- 
2.45.2