CIFS extension failing because of volume in use

Unmouting of the volume from service instance sometimes fails because
Windows clients tends to check the availability of shares even if not
mounted and the volume is in use then.

Fix finds out processes via smbstatus and kill them before unmounting.

Closes-Bug: 1703581
Change-Id: I2cbf959d7cb849d3ead1655b1a0932fd428a9e9f
Signed-off-by: Goutham Pacha Ravi <gouthampravi@gmail.com>

manila/share/drivers/helpers.py

@@ -529,6 +529,30 @@ class CIFSHelperIPAccess(CIFSHelperBase):
         ]
         self._ssh_exec(server, backup_exports)
         self._set_allow_hosts(server, [], share_name)
+        self._kick_out_users(server, share_name)
+
+    def _kick_out_users(self, server, share_name):
+        """Kick out all users of share"""
+        (out, _) = self._ssh_exec(server, ['sudo', 'smbstatus', '-S'])
+
+        shares = []
+        header = True
+        regexp = r"^(?P<share>[^ ]+)\s+(?P<pid>[0-9]+)\s+(?P<machine>[^ ]+).*"
+        for line in out.splitlines():
+            line = line.strip()
+            if not header and line:
+                match = re.match(regexp, line)
+                if match:
+                    shares.append(match.groupdict())
+                else:
+                    raise exception.ShareBackendException(
+                        msg="Failed to obtain smbstatus for %s!" % share_name)
+            elif line.startswith('----'):
+                header = False
+        to_kill = [s['pid'] for s in shares if
+                   share_name == s['share'] or share_name is None]
+        if to_kill:
+            self._ssh_exec(server, ['sudo', 'kill', '-15'] + to_kill)
 
     def restore_access_after_maintenance(self, server, share_name):
         maintenance_file = self._get_maintenance_file_path(share_name)

manila/tests/share/drivers/test_helpers.py

@@ -678,11 +678,39 @@ class CIFSHelperIPAccessTestCase(test.TestCase):
             self.server_details, self.share_name)
         self._helper._set_allow_hosts.assert_called_once_with(
             self.server_details, [], self.share_name)
+        kickoff_user_cmd = ['sudo', 'smbstatus', '-S']
+        self._helper._ssh_exec.assert_any_call(
+            self.server_details, kickoff_user_cmd)
         valid_cmd = ['echo', "'test test2'", '|', 'sudo', 'tee',
                      maintenance_path]
-        self._helper._ssh_exec.assert_called_once_with(
+        self._helper._ssh_exec.assert_any_call(
             self.server_details, valid_cmd)
 
+    def test__kick_out_users_success(self):
+        smbstatus_return = """Service      pid     machine       Connected at
+-------------------------------------------------------
+fake_share_name   1001   fake_machine1    Thu Sep 14 14:59:07 2017
+fake_share_name   1002   fake_machine2    Thu Sep 14 14:59:07 2017
+"""
+        self.mock_object(self._helper, '_ssh_exec', mock.Mock(
+            side_effect=[(smbstatus_return, "fake_stderr"), ("fake", "fake")]))
+        self._helper._kick_out_users(self.server_details, self.share_name)
+        self._helper._ssh_exec.assert_any_call(
+            self.server_details, ['sudo', 'smbstatus', '-S'])
+        self._helper._ssh_exec.assert_any_call(
+            self.server_details, ["sudo", "kill", "-15", "1001", "1002"])
+
+    def test__kick_out_users_failed(self):
+        smbstatus_return = """Service      pid     machine       Connected at
+-------------------------------------------------------
+fake line
+"""
+        self.mock_object(self._helper, '_ssh_exec', mock.Mock(
+            return_value=(smbstatus_return, "fake_stderr")))
+        self.assertRaises(exception.ShareBackendException,
+                          self._helper._kick_out_users, self.server_details,
+                          self.share_name)
+
     def test_restore_access_after_maintenance(self):
         fake_maintenance_path = "test.path"
         self.mock_object(self._helper, '_set_allow_hosts')

releasenotes/notes/bug-1703581-cifs-extension-failing-because-of-volume-in-use-3fea31c4a58e2f1b.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - Fixed the Generic driver to evict and kill any user processes accessing
+    a share before attempting to extend or shrink a CIFS share.