Merge pull request #1108 from phillxnet/1107_enhance_smart_return_cod…

…e_handling

enhance smart return code handling. Fixes #1107

src/rockstor/system/smart.py

@@ -46,8 +46,7 @@ def info(device, test_mode=TESTMODE):
         o, e, rc = run_command([SMART, '-H', '--info', '/dev/%s' % device],
                                throw=False)
     else:  # we are testing so use a smartctl -H --info file dump instead
-        o, e, rc = run_command([CAT, '/root/smartdumps/smart-H--info.out'],
-                               throw=False)
+        o, e, rc = run_command([CAT, '/root/smartdumps/smart-H--info.out'])
     res = {}
     # List of string matches to look for in smartctrl -H --info output.
     # Note the "|" char allows for defining alternative matches ie A or B
@@ -87,8 +86,7 @@ def extended_info(device, test_mode=TESTMODE):
     if not test_mode:
         o, e, rc = run_command([SMART, '-a', '/dev/%s' % device], throw=False)
     else:  # we are testing so use a smartctl -a file dump instead
-        o, e, rc = run_command([CAT, '/root/smartdumps/smart-a.out'],
-                               throw=False)
+        o, e, rc = run_command([CAT, '/root/smartdumps/smart-a.out'])
     attributes = {}
     for i in range(len(o)):
         if (re.match('Vendor Specific SMART Attributes with Thresholds:',
@@ -159,28 +157,18 @@ def error_logs(device, test_mode=TESTMODE):
     error number.
     :return: log_l: A list containing each line in turn of the error log.
     """
+    smart_command = [SMART, '-l', 'error', '/dev/%s' % device]
     if not test_mode:
-        o, e, rc = run_command([SMART, '-l', 'error', '/dev/%s' % device],
-                           throw=False)
+        o, e, rc = run_command(smart_command, throw=False)
     else:
-        o, e, rc = run_command([CAT, '/root/smartdumps/smart-l-error.out'],
-                           throw=False)
+        o, e, rc = run_command([CAT, '/root/smartdumps/smart-l-error.out'])
     # As we mute exceptions when calling the above command we should at least
     # examine what we have as return code (rc); 64 has been seen when the error
     # log contains errors but otherwise executes successfully so we catch this.
-    if rc == 64:
-        e_msg = 'Drive /dev/%s has logged S.M.A.R.T errors. Please view ' \
-                'the Error logs tab for this device.' % device
-        logger.error(e_msg)
-        email_root('S.M.A.R.T error', e_msg)
-    # In all other instances that are an error (non zero) we raise exception
-    # as normal.
-    elif rc != 0:
-        e_msg = ('non-zero code(%d) returned by command: %s -l error output: '
-                 '%s error: %s' % (rc, SMART, o, e))
-        logger.error(e_msg)
-        raise CommandException(('%s -l error /dev/%s' % (SMART, device)), o, e,
-                               rc)
+    overide_rc = 64
+    e_msg = 'Drive /dev/%s has logged S.M.A.R.T errors. Please view ' \
+                 'the Error logs tab for this device.' % device
+    screen_return_codes(e_msg, overide_rc, o, e, rc, smart_command)
     ecode_map = {
         'ABRT' : 'Command ABoRTed',
         'AMNF' : 'Address Mark Not Found',
@@ -238,12 +226,23 @@ def test_logs(device, test_mode=TESTMODE):
     :param test_mode: Not True causes cat from file rather than smartctl command
     :return: test_d as a dictionary of summarized test
     """
+    smart_command = [SMART, '-l', 'selftest', '-l', 'selective', '/dev/%s'
+                     % device]
     if not test_mode:
-        o, e, rc = run_command(
-            [SMART, '-l', 'selftest', '-l', 'selective', '/dev/%s' % device])
+        o, e, rc = run_command(smart_command, throw=False)
     else:
         o, e, rc = run_command(
             [CAT, '/root/smartdumps/smart-l-selftest-l-selective.out'])
+    # A return code of 128 (non zero so run_command raises an exception) has
+    # been seen when executing this command. Strange as it means
+    # "Invalid argument to exit" anyway if we silence the throw of a generic
+    # non 0 exception we can catch the 128, akin to 64 catch in error_logs().
+    # N.B. no official list of rc = 128 in /usr/include/sysexits.h
+    overide_rc = 128
+    e_msg = 'run_command(%s) returned an error of %s. This has undetermined ' \
+            'meaning. Please view the Self-Test Logs tab for this device.' \
+            % (smart_command, overide_rc)
+    screen_return_codes(e_msg, overide_rc, o, e, rc, smart_command)
     test_d = {}
     log_l = []
     for i in range(len(o)):
@@ -315,3 +314,30 @@ def update_config(config):
             tfo.write('%s\n' % l)
 
     return move(npath, SMARTD_CONFIG)
+
+
+def screen_return_codes(msg_on_hit, return_code_target, o, e, rc, command):
+    """
+    Provides a central mechanism to screen return codes from executing smart
+    commands. This is required as some non zero return codes would otherwise
+    trigger a generic exception clause in our general purpose run_command.
+    If the target return code is seen then email root with the message
+    provided, otherwise raise a generic exception with the command information.
+    N.B. May be done better by acting as a SMART run_command wrapper (Future).
+    :param msg_on_hit: message used to email root
+    :param return_code_target: return code to screen for
+    :param o: the output from the command when it was run
+    :param e: the error from the command when it was run
+    :param rc: the return code from running the command
+    """
+    # if our return code is our target then log with our message and email root
+    # with the same.
+    if rc == return_code_target:
+        logger.error(msg_on_hit)
+        email_root('S.M.A.R.T error', msg_on_hit)
+    # In all other non zero (error) instances we raise an exception as normal.
+    elif rc != 0:
+        e_msg = ('non-zero code(%d) returned by command: %s output: '
+                 '%s error: %s' % (rc, command, o, e))
+        logger.error(e_msg)
+        raise CommandException(('%s' % command), o, e, rc)