add todo entries and some comments for issue rockstor#997

It seems some SMART reports, in this case from an lsi controller,
differs in formatting and content, this is causing smart to appear as
not available or enabled and even if this wasn't the case the reports
differ such that current parsing is challenged to find relevant entries.

src/rockstor/system/smart.py

@@ -34,6 +34,11 @@ def info(device):
     #get smart info of the device, such as availability
     o, e, rc = run_command([SMART, '-H', '--info', '/dev/%s' % device], throw=False)
     res = {}
+    # todo add additional matching to account of eg some lsi formatting and name
+    # todo differences eg
+    # expected:- "SMART Health Status: OK"
+    # presented by lsi:- "SMART overall-health self-assessment test result: PASSED"
+    # Also note there are quite a few additional keys to look for here.
     matches = ('Model Family:', 'Device Model:', 'Serial Number:',
                'LU WWN Device Id:', 'Firmware Version:', 'User Capacity:',
                'Sector Size:', 'Rotation Rate:', 'Device is:', 'ATA Version is:',
@@ -96,6 +101,8 @@ def capabilities(device):
     return cap_d
 
 def error_logs(device):
+    # todo provide path to parse very differently parsed info from from example
+    # todo some lsi controllers.
     o, e, rc = run_command([SMART, '-l', 'error', '/dev/%s' % device],
                            throw=False)
     # As we mute exceptions when calling the above command we should at least
@@ -163,6 +170,7 @@ def error_logs(device):
     return (summary, log_l)
 
 def test_logs(device):
+    # todo need to confirm this as working on lsi controller reports
     o, e, rc = run_command([SMART, '-l', 'selftest', '-l', 'selective', '/dev/%s' % device])
     test_d = {}
     log_l = []
@@ -181,15 +189,22 @@ def test_logs(device):
     return (test_d, log_l)
 
 def run_test(device, test):
-    #start a smart test(short, long or conveyance)
+    # start a smart test(short, long or conveyance)
     return run_command([SMART, '-t', test, '/dev/%s' % device])
 
 def available(device):
-    #return true if SMART support is available on the device
+    """
+    Returns boolean pair: true if SMART support is available on the device and
+    true if SMART support is enabled.
+    Used by update_disk_state in views/disk.py to assess smart status
+    :param device:
+    :return: available (boolean), enabled (boolean)
+    """
     o, e, rc = run_command([SMART, '--info', ('/dev/%s' % device)])
     a = False
     e = False
     for i in o:
+        # todo Check on matching as sometimes multiple spaces after ":" ie on lsi9207
         if (re.match('SMART support is: Available', i) is not None):
             a = True
         if (re.match('SMART support is: Enabled', i) is not None):
@@ -198,7 +213,7 @@ def available(device):
 
 def toggle_smart(device, enable=False):
     switch = 'on' if (enable) else 'off'
-    #enable SMART support of the device
+    # enable SMART support of the device
     return run_command([SMART, '--smart=%s' % switch, '/dev/%s' % device])
 
 def update_config(config):
@@ -208,7 +223,7 @@ def update_config(config):
     with open(SMARTD_CONFIG) as sfo, open(npath, 'w') as tfo:
         for line in sfo.readlines():
             if (re.match('DEVICESCAN', line) is not None):
-                #comment out this line, if not, smartd ignores everything else
+                # comment out this line, if not, smartd ignores everything else
                 tfo.write('#%s' % line)
             elif (re.match(ROCKSTOR_HEADER, line) is None):
                 tfo.write(line)