[Mellanox] Fix issue: watchdogutil command does not work (sonic-net#1…

…6091)

- Why I did it
watchdogutil uses platform API watchdog instance to control/query watchdog status. In Nvidia watchdog status, it caches "armed" status in a object member "WatchdogImplBase.armed". This is not working for CLI infrastructure because each CLI will create a new watchdog instance, the status cached in previous instance will totally lose. Consider following commands:

admin@sonic:~$ sudo watchdogutil arm -s 100      =====> watchdog instance1, armed=True
Watchdog armed for 100 seconds
admin@sonic:~$ sudo watchdogutil status             ======> watchdog instance2, armed=False
Status: Unarmed
admin@sonic:~$ sudo watchdogutil disarm            =======> watchdog instance3, armed=False
Failed to disarm Watchdog

- How I did it
Use sysfs to query watchdog status

- How to verify it
Manual test
Unit test
Conflicts:
	platform/mellanox/mlnx-platform-api/sonic_platform/watchdog.py
	platform/mellanox/mlnx-platform-api/tests/test_watchdog.py

platform/mellanox/mlnx-platform-api/sonic_platform/watchdog.py

@@ -27,6 +27,7 @@
 import time
 
 from sonic_platform_base.watchdog_base import WatchdogBase
+from . import utils
 
 """ ioctl constants """
 IO_WRITE = 0x40000000
@@ -80,15 +81,17 @@ def __init__(self, wd_device_path):
         super(WatchdogImplBase, self).__init__()
 
         self.watchdog_path = wd_device_path
-        self.watchdog = os.open(self.watchdog_path, os.O_WRONLY)
+        self._watchdog = None
+        self.timeout = self._gettimeout()
 
-        # Opening a watchdog descriptor starts
-        # watchdog timer;
-        # by default it should be stopped
-        self._disablecard()
-        self.armed = False
+    @property
+    def watchdog(self):
+        if self._watchdog is None:
+            self._watchdog = self.open_handle()
+        return self._watchdog
 
-        self.timeout = self._gettimeout()
+    def open_handle(self):
+        return os.open(self.watchdog_path, os.O_WRONLY)
 
     def _enablecard(self):
         """
@@ -131,21 +134,15 @@ def _gettimeout(self):
         @return watchdog timeout
         """
 
-        req = array.array('I', [0])
-        fcntl.ioctl(self.watchdog, WDIOC_GETTIMEOUT, req, True)
-
-        return int(req[0])
+        return utils.read_int_from_file('/run/hw-management/watchdog/main/timeout')
 
     def _gettimeleft(self):
         """
         Get time left before watchdog timer expires
         @return time left in seconds
         """
 
-        req = array.array('I', [0])
-        fcntl.ioctl(self.watchdog, WDIOC_GETTIMELEFT, req, True)
-
-        return int(req[0])
+        return utils.read_int_from_file('/run/hw-management/watchdog/main/timeleft')
 
     def arm(self, seconds):
         """
@@ -159,11 +156,10 @@ def arm(self, seconds):
         try:
             if self.timeout != seconds:
                 self.timeout = self._settimeout(seconds)
-            if self.armed:
+            if self.is_armed():
                 self._keepalive()
             else:
                 self._enablecard()
-                self.armed = True
             ret = self.timeout
         except IOError:
             pass
@@ -176,10 +172,9 @@ def disarm(self):
         """
 
         disarmed = False
-        if self.armed:
+        if self.is_armed():
             try:
                 self._disablecard()
-                self.armed = False
                 disarmed = True
             except IOError:
                 pass
@@ -191,7 +186,7 @@ def is_armed(self):
         Implements is_armed WatchdogBase API
         """
 
-        return self.armed
+        return utils.read_str_from_file('/run/hw-management/watchdog/main/state') == 'active'
 
     def get_remaining_time(self):
         """
@@ -200,7 +195,7 @@ def get_remaining_time(self):
 
         timeleft = WD_COMMON_ERROR
 
-        if self.armed:
+        if self.is_armed():
             try:
                 timeleft = self._gettimeleft()
             except IOError:
@@ -213,13 +208,15 @@ def __del__(self):
         Close watchdog
         """
 
-        os.close(self.watchdog)
+        if self._watchdog is not None:
+            os.close(self._watchdog)
 
 
 class WatchdogType1(WatchdogImplBase):
     """
     Watchdog type 1
     """
+    TIMESTAMP_FILE = '/tmp/nvidia/watchdog_timestamp'
 
     def arm(self, seconds):
         """
@@ -230,7 +227,8 @@ def arm(self, seconds):
         ret = WatchdogImplBase.arm(self, seconds)
         # Save the watchdog arm timestamp
         # requiered for get_remaining_time()
-        self.arm_timestamp = time.time()
+        os.makedirs('/tmp/nvidia', exist_ok=True)
+        utils.write_file(self.TIMESTAMP_FILE, str(time.time()))
 
         return ret
 
@@ -243,8 +241,9 @@ def get_remaining_time(self):
 
         timeleft = WD_COMMON_ERROR
 
-        if self.armed:
-            timeleft = int(self.timeout - (time.time() - self.arm_timestamp))
+        if self.is_armed():
+            arm_timestamp = utils.read_float_from_file(self.TIMESTAMP_FILE)
+            timeleft = int(self.timeout - (time.time() - arm_timestamp))
 
         return timeleft
 

platform/mellanox/mlnx-platform-api/tests/test_watchdog.py

@@ -0,0 +1,141 @@
+#
+# Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
+# Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import os
+import pytest
+import sys
+if sys.version_info.major == 3:
+    from unittest import mock
+else:
+    import mock
+
+test_path = os.path.dirname(os.path.abspath(__file__))
+modules_path = os.path.dirname(test_path)
+sys.path.insert(0, modules_path)
+
+from sonic_platform.chassis import Chassis
+from sonic_platform.watchdog import get_watchdog,    \
+                                    WatchdogType2,   \
+                                    WatchdogType1,   \
+                                    is_mlnx_wd_main, \
+                                    is_wd_type2
+
+
+class TestWatchdog:
+    @mock.patch('sonic_platform.watchdog.is_mlnx_wd_main')
+    @mock.patch('sonic_platform.watchdog.os.listdir')
+    def test_get_watchdog_no_device(self, mock_listdir, mock_is_main):
+        mock_listdir.return_value = []
+        assert get_watchdog() is None
+
+        mock_listdir.return_value = ['invalid']
+        mock_is_main.return_value = True
+        assert get_watchdog() is None
+
+        mock_listdir.return_value = ['watchdog1']
+        mock_is_main.return_value = False
+        assert get_watchdog() is None
+
+    @mock.patch('sonic_platform.watchdog.is_mlnx_wd_main')
+    @mock.patch('sonic_platform.watchdog.is_wd_type2')
+    @mock.patch('sonic_platform.watchdog.os.listdir', mock.MagicMock(return_value=['watchdog1', 'watchdog2']))
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase.open_handle', mock.MagicMock())
+    @mock.patch('sonic_platform.watchdog.fcntl.ioctl', mock.MagicMock())
+    @pytest.mark.parametrize('test_para',
+                             [(True, WatchdogType2), (False, WatchdogType1)])
+    def test_get_watchdog(self, mock_is_type2, mock_is_main, test_para):
+        mock_is_main.side_effect = lambda dev: dev == 'watchdog2'
+        mock_is_type2.return_value = test_para[0]
+        chassis = Chassis()
+        watchdog = chassis.get_watchdog()
+        assert isinstance(watchdog, test_para[1])
+        assert watchdog.watchdog_path == '/dev/watchdog2'
+
+    def test_is_mlnx_wd_main(self):
+        mock_os_open = mock.mock_open(read_data='mlx-wdt-main')
+        with mock.patch('sonic_platform.watchdog.open', mock_os_open):
+            assert is_mlnx_wd_main('')
+
+        mock_os_open = mock.mock_open(read_data='invalid')
+        with mock.patch('sonic_platform.watchdog.open', mock_os_open):
+            assert not is_mlnx_wd_main('')
+        mock_os_open.side_effect = IOError
+        with mock.patch('sonic_platform.watchdog.open', mock_os_open):
+            assert not is_mlnx_wd_main('')
+
+    @mock.patch('sonic_platform.watchdog.os.path.exists')
+    @pytest.mark.parametrize('test_para',
+                             [True, False])
+    def test_is_wd_type2(self, mock_exists, test_para):
+        mock_exists.return_value = test_para
+        assert is_wd_type2('') is test_para
+
+    @mock.patch('sonic_platform.utils.read_str_from_file')
+    def test_is_armed(self, mock_read):
+        watchdog = WatchdogType2('watchdog2')
+        mock_read.return_value = 'inactive'
+        assert not watchdog.is_armed()
+        mock_read.return_value = 'active'
+        assert watchdog.is_armed()
+
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase.open_handle', mock.MagicMock())
+    @mock.patch('sonic_platform.watchdog.fcntl.ioctl', mock.MagicMock())
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase.is_armed')
+    def test_arm_disarm_watchdog2(self, mock_is_armed):
+        watchdog = WatchdogType2('watchdog2')
+        assert watchdog.arm(-1) == -1
+        mock_is_armed.return_value = False
+        watchdog.arm(10)
+        mock_is_armed.return_value = True
+        watchdog.arm(5)
+        watchdog.disarm()
+
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase.open_handle', mock.MagicMock())
+    @mock.patch('sonic_platform.watchdog.fcntl.ioctl', mock.MagicMock())
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase.is_armed')
+    def test_arm_disarm_watchdog1(self, mock_is_armed):
+        watchdog = WatchdogType1('watchdog1')
+        assert watchdog.arm(-1) == -1
+        mock_is_armed.return_value = False
+        watchdog.arm(10)
+        mock_is_armed.return_value = True
+        watchdog.arm(5)
+        watchdog.disarm()
+
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase.open_handle', mock.MagicMock())
+    @mock.patch('sonic_platform.watchdog.fcntl.ioctl', mock.MagicMock())
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase._gettimeleft', mock.MagicMock(return_value=10))
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase.is_armed')
+    def test_get_remaining_time_watchdog2(self, mock_is_armed):
+        watchdog = WatchdogType2('watchdog2')
+        mock_is_armed.return_value = False
+        assert watchdog.get_remaining_time() == -1
+        watchdog.arm(10)
+        mock_is_armed.return_value = True
+        assert watchdog.get_remaining_time() == 10
+
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase.open_handle', mock.MagicMock())
+    @mock.patch('sonic_platform.watchdog.fcntl.ioctl', mock.MagicMock())
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase._gettimeleft', mock.MagicMock(return_value=10))
+    @mock.patch('sonic_platform.watchdog.WatchdogImplBase.is_armed')
+    def test_get_remaining_time_watchdog1(self, mock_is_armed):
+        watchdog = WatchdogType1('watchdog2')
+        mock_is_armed.return_value = False
+        assert watchdog.get_remaining_time() == -1
+        watchdog.arm(10)
+        mock_is_armed.return_value = True
+        assert watchdog.get_remaining_time() > 0