Fixes nova-volume support for multiple luns

 * stores lun in provider_location if specified
 * passes lun in iscsi_properties instead of hard coding
 * adds call to libvirt to list all used block devices
 * make sure to synchronize connect and disconnect commands
 * only disconnect from target if no luns are in use
 * allow double logins to targets
 * fixes typo in get_volume_connector in xenapi_connection
 * fixes bug 929790

Change-Id: I2466dc750a6fa5e0b07f94314d38873740aa6b29

3 files changed, 47 insertions, 17 deletions

diff --git a/nova/virt/libvirt/connection.py b/nova/virt/libvirt/connection.py
index c3bfdedda..349faa157 100644
--- a/nova/virt/libvirt/connection.py
+++ b/nova/virt/libvirt/connection.py
@@ -1388,6 +1388,26 @@ class LibvirtConnection(driver.ComputeDriver):
 
         return domain
 
+    def get_all_block_devices(self):
+        """
+        Return all block devices in use on this node.
+        """
+        devices = []
+        for dom_id in self._conn.listDomainsID():
+            domain = self._conn.lookupByID(dom_id)
+            try:
+                doc = ElementTree.fromstring(domain.XMLDesc(0))
+            except Exception:
+                continue
+            ret = doc.findall('./devices/disk')
+            for node in ret:
+                if node.get('type') != 'block':
+                    continue
+                for child in node.getchildren():
+                    if child.tag == 'source':
+                        devices.append(child.get('dev'))
+        return devices
+
     def get_disks(self, instance_name):
         """
         Note that this function takes an instance name.
diff --git a/nova/virt/libvirt/volume.py b/nova/virt/libvirt/volume.py
index 75fa0e5a9..055e34abc 100644
--- a/nova/virt/libvirt/volume.py
+++ b/nova/virt/libvirt/volume.py
@@ -103,14 +103,16 @@ class LibvirtISCSIVolumeDriver(LibvirtVolumeDriver):
                          '-v', property_value)
         return self._run_iscsiadm(iscsi_properties, iscsi_command)
 
+    @utils.synchronized('connect_volume')
     def connect_volume(self, connection_info, mount_device):
         """Attach the volume to instance_name"""
         iscsi_properties = connection_info['data']
-        # NOTE(vish): if we are on the same host as nova volume, the
+        # NOTE(vish): If we are on the same host as nova volume, the
         #             discovery makes the target so we don't need to
         #             run --op new. Therefore, we check to see if the
         #             target exists, and if we get 255 (Not Found), then
-        #             we run --op new
+        #             we run --op new. This will also happen if another
+        #             volume is using the same target.
         try:
             self._run_iscsiadm(iscsi_properties, ())
         except exception.ProcessExecutionError as exc:
@@ -131,18 +133,17 @@ class LibvirtISCSIVolumeDriver(LibvirtVolumeDriver):
                                   "node.session.auth.password",
                                   iscsi_properties['auth_password'])
 
-        self._run_iscsiadm(iscsi_properties, ("--login",))
+        # NOTE(vish): If we have another lun on the same target, we may
+        #             have a duplicate login
+        self._run_iscsiadm(iscsi_properties, ("--login",),
+                           check_exit_code=[0, 255])
 
         self._iscsiadm_update(iscsi_properties, "node.startup", "automatic")
 
-        if FLAGS.iscsi_helper == 'tgtadm':
-            host_device = ("/dev/disk/by-path/ip-%s-iscsi-%s-lun-1" %
-                            (iscsi_properties['target_portal'],
-                             iscsi_properties['target_iqn']))
-        else:
-            host_device = ("/dev/disk/by-path/ip-%s-iscsi-%s-lun-0" %
-                            (iscsi_properties['target_portal'],
-                             iscsi_properties['target_iqn']))
+        host_device = ("/dev/disk/by-path/ip-%s-iscsi-%s-lun-%s" %
+                        (iscsi_properties['target_portal'],
+                         iscsi_properties['target_iqn'],
+                         iscsi_properties.get('target_lun', 0)))
 
         # The /dev/disk/by-path/... node is not always present immediately
         # TODO(justinsb): This retry-with-delay is a pattern, move to utils?
@@ -172,13 +173,22 @@ class LibvirtISCSIVolumeDriver(LibvirtVolumeDriver):
         sup = super(LibvirtISCSIVolumeDriver, self)
         return sup.connect_volume(connection_info, mount_device)
 
+    @utils.synchronized('connect_volume')
     def disconnect_volume(self, connection_info, mount_device):
         """Detach the volume from instance_name"""
         sup = super(LibvirtISCSIVolumeDriver, self)
         sup.disconnect_volume(connection_info, mount_device)
         iscsi_properties = connection_info['data']
-        self._iscsiadm_update(iscsi_properties, "node.startup", "manual")
-        self._run_iscsiadm(iscsi_properties, ("--logout",),
-                           check_exit_code=[0, 255])
-        self._run_iscsiadm(iscsi_properties, ('--op', 'delete'),
-                           check_exit_code=[0, 255])
+        # NOTE(vish): Only disconnect from the target if no luns from the
+        #             target are in use.
+        device_prefix = ("/dev/disk/by-path/ip-%s-iscsi-%s-lun-" %
+                         (iscsi_properties['target_portal'],
+                          iscsi_properties['target_iqn']))
+        devices = self.connection.get_all_block_devices()
+        devices = [dev for dev in devices if dev.startswith(device_prefix)]
+        if not devices:
+            self._iscsiadm_update(iscsi_properties, "node.startup", "manual")
+            self._run_iscsiadm(iscsi_properties, ("--logout",),
+                               check_exit_code=[0, 255])
+            self._run_iscsiadm(iscsi_properties, ('--op', 'delete'),
+                               check_exit_code=[0, 255])
diff --git a/nova/virt/xenapi_conn.py b/nova/virt/xenapi_conn.py
index 1e2d11bb0..08542268c 100644
--- a/nova/virt/xenapi_conn.py
+++ b/nova/virt/xenapi_conn.py
@@ -346,7 +346,7 @@ class XenAPIConnection(driver.ComputeDriver):
     def get_volume_connector(self, _instance):
         """Return volume connector information"""
         if not self._initiator:
-            stats = self.get_host_stats(update=True)
+            stats = self.get_host_stats(refresh=True)
             try:
                 self._initiator = stats['host_other-config']['iscsi_iqn']
             except (TypeError, KeyError):