Do not raise NEW exceptions

Raising NEW exception is bad practice, because we lose TraceBack.
So all places like:

except SomeException as e:
    raise e

should be replaced by

except SomeException:
    raise

If we are doing some other actions before reraising we should
store information about exception then do all actions and then
reraise it. This is caused by eventlet bug. It lost information
about exception if it switch threads.

fixes bug 1191730
Change-Id: Ic2be96e9f03d2ca46d060caf6f6f7f713a1d6b82

HACKING.rst

@@ -55,6 +55,15 @@ General
               {'vol_name': vol_name,
                'vol_size': vol_size}) # OKAY
 
+- Use 'raise' instead of 'raise e' to preserve original traceback or exception being reraised::
+
+    except Exception as e:
+        ...
+        raise e  # BAD
+
+    except Exception:
+        ...
+        raise  # OKAY
 
 Imports
 -------

cinder/exception.py

@@ -24,6 +24,8 @@ SHOULD include dedicated exception logging.
 
 """
 
+import sys
+
 from oslo.config import cfg
 import webob.exc
 
@@ -105,17 +107,17 @@ class CinderException(Exception):
             try:
                 message = self.message % kwargs
 
-            except Exception as e:
+            except Exception:
+                exc_info = sys.exc_info()
                 # kwargs doesn't match a variable in the message
                 # log the issue and the kwargs
                 LOG.exception(_('Exception in string format operation'))
                 for name, value in kwargs.iteritems():
                     LOG.error("%s: %s" % (name, value))
                 if CONF.fatal_exception_format_errors:
-                    raise e
+                    raise exc_info[0], exc_info[1], exc_info[2]
-                else:
+                # at least get the core message out if something happened
-                    # at least get the core message out if something happened
+                message = self.message
-                    message = self.message
 
         super(CinderException, self).__init__(message)
 

cinder/tests/test_netapp_nfs.py

@@ -386,6 +386,6 @@ class NetappDirect7modeNfsDriverTestCase(NetappDirectCmodeNfsDriverTestCase):
             if isinstance(e, api.NaApiError):
                 pass
             else:
-                raise e
+                raise
 
         mox.VerifyAll()

cinder/tests/test_scality.py

@@ -61,7 +61,7 @@ class ScalityDriverTestCase(test.TestCase):
             os.makedirs(path)
         except OSError as e:
             if e.errno != errno.EEXIST:
-                raise e
+                raise
 
     def _create_fake_config(self):
         open(self.TEST_CONFIG, "w+").close()
@@ -75,7 +75,7 @@ class ScalityDriverTestCase(test.TestCase):
             os.unlink(self.TEST_CONFIG)
         except OSError as e:
             if e.errno != errno.ENOENT:
-                raise e
+                raise
 
     def _configure_driver(self):
         scality.CONF.scality_sofs_config = self.TEST_CONFIG

cinder/tests/test_storwize_svc.py

@@ -24,6 +24,7 @@
 Tests for the IBM Storwize family and SVC volume driver.
 """
 
+
 import random
 import re
 import socket
@@ -1610,7 +1611,7 @@ class StorwizeSVCDriverTestCase(test.TestCase):
                         self.assertEqual(attrs[k], v)
                 except exception.ProcessExecutionError as e:
                     if 'CMMVC7050E' not in e.stderr:
-                        raise e
+                        raise
 
     def test_storwize_svc_unicode_host_and_volume_names(self):
         # We'll check with iSCSI only - nothing protocol-dependednt here

cinder/transfer/api.py

@@ -27,6 +27,7 @@ from oslo.config import cfg
 
 from cinder.db import base
 from cinder import exception
+from cinder.openstack.common import excutils
 from cinder.openstack.common import log as logging
 from cinder import quota
 from cinder.volume import api as volume_api
@@ -192,12 +193,12 @@ class API(base.Base):
             if donor_reservations:
                 QUOTAS.commit(context, donor_reservations, project_id=donor_id)
             LOG.info(_("Volume %s has been transferred.") % volume_id)
-        except Exception as exc:
+        except Exception:
-            QUOTAS.rollback(context, reservations)
+            with excutils.save_and_reraise_exception():
-            if donor_reservations:
+                QUOTAS.rollback(context, reservations)
-                QUOTAS.rollback(context, donor_reservations,
+                if donor_reservations:
-                                project_id=donor_id)
+                    QUOTAS.rollback(context, donor_reservations,
-            raise exc
+                                    project_id=donor_id)
 
         vol_ref = self.db.volume_get(context, volume_id)
         return {'id': transfer_id,

cinder/volume/drivers/hds/hds.py

@@ -24,6 +24,7 @@ from oslo.config import cfg
 from xml.etree import ElementTree as ETree
 
 from cinder import exception
+from cinder.openstack.common import excutils
 from cinder.openstack.common import log as logging
 from cinder import utils
 from cinder.volume import driver
@@ -86,8 +87,8 @@ def _xml_read(root, element, check=None):
         return None
     except ETree.ParseError as e:
         if check:
-            LOG.error(_("XML exception reading parameter: %s") % element)
+            with excutils.save_and_reraise_exception():
-            raise e
+                LOG.error(_("XML exception reading parameter: %s") % element)
         else:
             LOG.info(_("XML exception reading parameter: %s") % element)
             return None

cinder/volume/drivers/netapp/iscsi.py

@@ -22,6 +22,7 @@ This driver requires NetApp Clustered Data ONTAP or 7-mode
 storage systems with installed iSCSI licenses.
 """
 
+import sys
 import time
 import uuid
 
@@ -402,12 +403,13 @@ class NetAppDirectISCSIDriver(driver.ISCSIDriver):
             message = e.message
             msg = _('Error mapping lun. Code :%(code)s, Message:%(message)s')
             msg_fmt = {'code': code, 'message': message}
+            exc_info = sys.exc_info()
             LOG.warn(msg % msg_fmt)
             (igroup, lun_id) = self._find_mapped_lun_igroup(path, initiator)
             if lun_id is not None:
                 return lun_id
             else:
-                raise e
+                raise exc_info[0], exc_info[1], exc_info[2]
 
     def _unmap_lun(self, path, initiator):
         """Unmaps a lun from given initiator."""
@@ -422,12 +424,13 @@ class NetAppDirectISCSIDriver(driver.ISCSIDriver):
             msg = _("Error unmapping lun. Code :%(code)s,"
                     " Message:%(message)s")
             msg_fmt = {'code': e.code, 'message': e.message}
+            exc_info = sys.exc_info()
             LOG.warn(msg % msg_fmt)
             # if the lun is already unmapped
             if e.code == '13115' or e.code == '9016':
                 pass
             else:
-                raise e
+                raise exc_info[0], exc_info[1], exc_info[2]
 
     def _find_mapped_lun_igroup(self, path, initiator, os=None):
         """Find the igroup for mapped lun with initiator."""

cinder/volume/drivers/netapp/nfs.py

@@ -397,7 +397,7 @@ class NetAppDirect7modeNfsDriver (NetAppDirectNfsDriver):
             except NaApiError as e:
                 if e.code != 'UnknownCloneId':
                     self._clear_clone(clone_id)
-                raise e
+                raise
 
     def _get_actual_path_for_export(self, export_path):
         """Gets the actual path on the filer for export path."""

cinder/volume/drivers/san/hp/hp_3par_common.py

@@ -36,6 +36,8 @@ hp3par_api_url, hp3par_username, hp3par_password
 for credentials to talk to the REST service on the 3PAR
 array.
 """
+
+
 import base64
 import json
 import paramiko
@@ -52,10 +54,12 @@ from oslo.config import cfg
 
 from cinder import context
 from cinder import exception
+from cinder.openstack.common import excutils
 from cinder.openstack.common import log as logging
 from cinder import utils
 from cinder.volume import volume_types
 
+
 LOG = logging.getLogger(__name__)
 
 hp3par_opts = [
@@ -313,9 +317,9 @@ exit
                          "attempts : '%(command)s'") %
                        {'total_attempts': total_attempts, 'command': command})
                 raise paramiko.SSHException(msg)
-        except Exception as e:
+        except Exception:
-            LOG.error(_("Error running ssh command: %s") % command)
+            with excutils.save_and_reraise_exception():
-            raise e
+                LOG.error(_("Error running ssh command: %s") % command)
 
     def _delete_3par_host(self, hostname):
         self._cli_run('removehost %s' % hostname, None)

cinder/volume/drivers/san/san.py

@@ -27,6 +27,7 @@ from eventlet import greenthread
 from oslo.config import cfg
 
 from cinder import exception
+from cinder.openstack.common import excutils
 from cinder.openstack.common import log as logging
 from cinder import utils
 from cinder.volume.driver import ISCSIDriver
@@ -143,9 +144,9 @@ class SanISCSIDriver(ISCSIDriver):
                         stderr="Error running SSH command",
                         cmd=command)
 
-        except Exception as e:
+        except Exception:
-            LOG.error(_("Error running SSH command: %s") % command)
+            with excutils.save_and_reraise_exception():
-            raise e
+                LOG.error(_("Error running SSH command: %s") % command)
 
     def ensure_export(self, context, volume):
         """Synchronously recreates an export for a logical volume."""

cinder/volume/drivers/scality.py

@@ -16,6 +16,7 @@
 Scality SOFS Volume Driver.
 """
 
+
 import errno
 import os
 import urllib2
@@ -28,6 +29,7 @@ from cinder.image import image_utils
 from cinder.openstack.common import log as logging
 from cinder.volume import driver
 
+
 LOG = logging.getLogger(__name__)
 
 volume_opts = [
@@ -85,7 +87,7 @@ class ScalityDriver(driver.VolumeDriver):
             os.makedirs(path)
         except OSError as e:
             if e.errno != errno.EEXIST:
-                raise e
+                raise
 
     def _mount_sofs(self):
         config = CONF.scality_sofs_config