Fix race condition in ISCSIConnector disconnect_volume

The list of devices returned by driver.get_all_block_devices() will
sometimes contain broken symlinks as the SCSI device has been deleted
but the udev rule for the symlink has not yet completed.

Adding in a check to os.path.exists() will ensure that we will not
consider the broken symlinks as an “in use” device.

Change-Id: Ibb869e10976f894f9e18e9edec6739c2c3bea68c
Closes-Bug: #1375382

diff --git a/cinder/brick/initiator/connector.py b/cinder/brick/initiator/connector.py
index b58e726b2d67b8e8777e65520ace4f025bce4ddb..fb7277791270478bd780f06b435c93544e3eb5e0 100644 (file)
--- a/cinder/brick/initiator/connector.py
+++ b/cinder/brick/initiator/connector.py
@@ -291,7 +291,8 @@ class ISCSIConnector(InitiatorConnector):
                          {'portal': connection_properties['target_portal'],
                           'iqn': connection_properties['target_iqn']})
         devices = self.driver.get_all_block_devices()
-        devices = [dev for dev in devices if dev.startswith(device_prefix)]
+        devices = [dev for dev in devices if dev.startswith(device_prefix)
+                   and os.path.exists(dev)]
 
         if not devices:
             self._disconnect_from_iscsi_portal(connection_properties)