Merge "Fix multipath device discovery when UFN is enabled."

2 files changed, 75 insertions, 22 deletions

diff --git a/nova/storage/linuxscsi.py b/nova/storage/linuxscsi.py
index ed30462ec0..285dda96f6 100644
--- a/nova/storage/linuxscsi.py
+++ b/nova/storage/linuxscsi.py
@@ -21,8 +21,13 @@ from nova.i18n import _LW
 from nova.openstack.common import loopingcall
 from nova import utils
 
+import os
+import re
+
 LOG = logging.getLogger(__name__)
 
+MULTIPATH_WWID_REGEX = re.compile("\((?P<wwid>.+)\)")
+
 
 def echo_scsi_command(path, content):
     """Used to echo strings to scsi subsystem."""
@@ -106,23 +111,29 @@ def find_multipath_device(device):
         lines = out.strip()
         lines = lines.split("\n")
         if lines:
-            line = lines[0]
-            info = line.split(" ")
-            # device line output is different depending
-            # on /etc/multipath.conf settings.
-            if info[1][:2] == "dm":
-                mdev_id = info[0]
-                mdev = '/dev/mapper/%s' % mdev_id
-            elif info[2][:2] == "dm":
-                mdev_id = info[1].replace('(', '')
-                mdev_id = mdev_id.replace(')', '')
-                mdev = '/dev/mapper/%s' % mdev_id
-
-            if mdev is None:
-                LOG.warning(_LW("Couldn't find multipath device %s"), line)
+
+            # Use the device name, be it the WWID, mpathN or custom alias of
+            # a device to build the device path. This should be the first item
+            # on the first line of output from `multipath -l /dev/${path}`.
+            mdev_name = lines[0].split(" ")[0]
+            mdev = '/dev/mapper/%s' % mdev_name
+
+            # Find the WWID for the LUN if we are using mpathN or aliases.
+            wwid_search = MULTIPATH_WWID_REGEX.search(lines[0])
+            if wwid_search is not None:
+                mdev_id = wwid_search.group('wwid')
+            else:
+                mdev_id = mdev_name
+
+            # Confirm that the device is present.
+            try:
+                os.stat(mdev)
+            except OSError:
+                LOG.warning(_LW("Couldn't find multipath device %s"), mdev)
                 return None
 
             LOG.debug("Found multipath device = %s", mdev)
+
             device_lines = lines[3:]
             for dev_line in device_lines:
                 if dev_line.find("policy") != -1:
@@ -147,6 +158,7 @@ def find_multipath_device(device):
     if mdev is not None:
         info = {"device": mdev,
                 "id": mdev_id,
+                "name": mdev_name,
                 "devices": devices}
         return info
     return None
diff --git a/nova/tests/unit/test_linuxscsi.py b/nova/tests/unit/test_linuxscsi.py
index 45d6212a80..279b3c9a6a 100644
--- a/nova/tests/unit/test_linuxscsi.py
+++ b/nova/tests/unit/test_linuxscsi.py
@@ -20,6 +20,8 @@ from nova.storage import linuxscsi
 from nova import test
 from nova import utils
 
+import os
+
 LOG = logging.getLogger(__name__)
 
 CONF = cfg.CONF
@@ -29,16 +31,21 @@ class StorageLinuxSCSITestCase(test.NoDBTestCase):
     def setUp(self):
         super(StorageLinuxSCSITestCase, self).setUp()
         self.executes = []
+        self.fake_stat_result = os.stat(__file__)
 
         def fake_execute(*cmd, **kwargs):
             self.executes.append(cmd)
             return None, None
 
+        def fake_stat(path):
+            return self.fake_stat_result
+
         self.stubs.Set(utils, 'execute', fake_execute)
+        self.stubs.Set(os, 'stat', fake_stat)
 
     def test_find_multipath_device_3par(self):
         def fake_execute(*cmd, **kwargs):
-            out = ("mpath6 (350002ac20398383d) dm-3 3PARdata,VV\n"
+            out = ("350002ac20398383d dm-3 3PARdata,VV\n"
                    "size=2.0G features='0' hwhandler='0' wp=rw\n"
                    "`-+- policy='round-robin 0' prio=-1 status=active\n"
                    "  |- 0:0:0:1 sde 8:64 active undef running\n"
@@ -46,12 +53,34 @@ class StorageLinuxSCSITestCase(test.NoDBTestCase):
                    )
             return out, None
 
-        def fake_execute2(*cmd, **kwargs):
-            out = ("350002ac20398383d dm-3 3PARdata,VV\n"
+        self.stubs.Set(utils, 'execute', fake_execute)
+
+        info = linuxscsi.find_multipath_device('/dev/sde')
+        LOG.error("info = %s" % info)
+
+        self.assertEqual("350002ac20398383d", info["name"])
+        self.assertEqual("350002ac20398383d", info["id"])
+        self.assertEqual("/dev/mapper/350002ac20398383d", info["device"])
+
+        self.assertEqual("/dev/sde", info['devices'][0]['device'])
+        self.assertEqual("0", info['devices'][0]['host'])
+        self.assertEqual("0", info['devices'][0]['id'])
+        self.assertEqual("0", info['devices'][0]['channel'])
+        self.assertEqual("1", info['devices'][0]['lun'])
+
+        self.assertEqual("/dev/sdf", info['devices'][1]['device'])
+        self.assertEqual("2", info['devices'][1]['host'])
+        self.assertEqual("0", info['devices'][1]['id'])
+        self.assertEqual("0", info['devices'][1]['channel'])
+        self.assertEqual("1", info['devices'][1]['lun'])
+
+    def test_find_multipath_device_3par_ufn(self):
+        def fake_execute(*cmd, **kwargs):
+            out = ("mpath6 (350002ac20398383d) dm-3 3PARdata,VV\n"
                    "size=2.0G features='0' hwhandler='0' wp=rw\n"
                    "`-+- policy='round-robin 0' prio=-1 status=active\n"
-                   "  |- 0:0:0:1  sde 8:64 active undef running\n"
-                   "  `- 2:0:0:1  sdf 8:80 active undef running\n"
+                   "  |- 0:0:0:1 sde 8:64 active undef running\n"
+                   "  `- 2:0:0:1 sdf 8:80 active undef running\n"
                    )
             return out, None
 
@@ -59,7 +88,11 @@ class StorageLinuxSCSITestCase(test.NoDBTestCase):
 
         info = linuxscsi.find_multipath_device('/dev/sde')
         LOG.error("info = %s" % info)
-        self.assertEqual("/dev/mapper/350002ac20398383d", info["device"])
+
+        self.assertEqual("mpath6", info["name"])
+        self.assertEqual("350002ac20398383d", info["id"])
+        self.assertEqual("/dev/mapper/mpath6", info["device"])
+
         self.assertEqual("/dev/sde", info['devices'][0]['device'])
         self.assertEqual("0", info['devices'][0]['host'])
         self.assertEqual("0", info['devices'][0]['id'])
@@ -90,8 +123,12 @@ class StorageLinuxSCSITestCase(test.NoDBTestCase):
 
         info = linuxscsi.find_multipath_device('/dev/sde')
         LOG.error("info = %s" % info)
+
+        self.assertEqual("36005076da00638089c000000000004d5", info["name"])
+        self.assertEqual("36005076da00638089c000000000004d5", info["id"])
         self.assertEqual("/dev/mapper/36005076da00638089c000000000004d5",
                          info["device"])
+
         self.assertEqual("/dev/sde", info['devices'][0]['device'])
         self.assertEqual("6", info['devices'][0]['host'])
         self.assertEqual("0", info['devices'][0]['channel'])
@@ -110,8 +147,8 @@ class StorageLinuxSCSITestCase(test.NoDBTestCase):
                    "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"
+                   "  |- 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
 
@@ -119,8 +156,12 @@ class StorageLinuxSCSITestCase(test.NoDBTestCase):
 
         info = linuxscsi.find_multipath_device('/dev/sdd')
         LOG.error("info = %s" % info)
+
+        self.assertEqual("36005076303ffc48e0000000000000101", info["name"])
+        self.assertEqual("36005076303ffc48e0000000000000101", info["id"])
         self.assertEqual("/dev/mapper/36005076303ffc48e0000000000000101",
                          info["device"])
+
         self.assertEqual("/dev/sdd", info['devices'][0]['device'])
         self.assertEqual("6", info['devices'][0]['host'])
         self.assertEqual("0", info['devices'][0]['channel'])