Smart array: Handle errored disk

Resolves: libstorage#420

Note: This change is an adaptation of the one provided by
Christophe Stoyanov.  Specifically, when we cannot retrieve all
the needed values we select default values of the proper type
and domain eg.

id, disk_name -> string
blk_size, blk_count -> unsigned integer
rpm -> Disk.RPM_UNKNOWN

Signed-off-by: Tony Asleson <tasleson@redhat.com>

plugin/hpsa/hpsa.py

@@ -341,6 +341,9 @@ def _disk_link_type_of(hp_disk):
 _HP_VENDOR_RAID_LEVELS = ['1adm', '1+0adm']
 
 
+NOT_AVAILABLE_MESSAGE = 'N/A'
+
+
 _LSM_RAID_TYPE_CONV = dict(
     list(zip(list(_HP_RAID_LEVEL_CONV.values()),
              list(_HP_RAID_LEVEL_CONV.keys()))))
@@ -714,16 +717,27 @@ def volumes(self, search_key=None, search_value=None,
     @staticmethod
     def _hp_disk_to_lsm_disk(hp_disk, sys_id, ctrl_num, key_name,
                              flag_free=False):
-        disk_id = hp_disk['Serial Number']
         disk_num = key_name[len("physicaldrive "):]
-        disk_name = "%s %s" % (hp_disk['Model'], disk_num)
+
+        # If the disk is in error, Serial Number will be missing, we will
+        # concat the N/A message with the disk number so that the user can
+        # have a unique disk id if more than one disk is in error.
+        disk_id = hp_disk.get('Serial Number',
+                              "%s:%s" % (NOT_AVAILABLE_MESSAGE, disk_num))
+        disk_name = "%s %s" % (hp_disk.get('Model', NOT_AVAILABLE_MESSAGE),
+                               disk_num)
         disk_type = _disk_type_of(hp_disk)
         try:
-            blk_size_str = hp_disk['Native Block Size']
+            blk_size_str = hp_disk.get('Native Block Size', '0')
         except KeyError:
-            blk_size_str = hp_disk['Logical/Physical Block Size'].split("/")[0]
+            blk_size_str = hp_disk.get('Logical/Physical Block Size', '0/0').split("/")[0]
         blk_size = int(blk_size_str)
-        blk_count = int(int_div(_hp_size_to_lsm(hp_disk['Size']), blk_size))
+        disk_size = hp_disk.get('Size', None)
+
+        if blk_size == 0 or disk_size is None:
+            blk_count = 0
+        else:
+            blk_count = int(int_div(_hp_size_to_lsm(disk_size), blk_size))
         try:
             disk_port, disk_box, disk_bay = disk_num.split(":")
         except ValueError:
@@ -743,8 +757,15 @@ def _hp_disk_to_lsm_disk(hp_disk, sys_id, ctrl_num, key_name,
             vpd83 = LocalDisk.vpd83_get(disk_path)
         else:
             vpd83 = ''
-        rpm = int(hp_disk.get('Rotational Speed',
-                              Disk.RPM_NON_ROTATING_MEDIUM))
+
+        # If we cannot retrieve the disk name, the RPM is missing.  However,
+        # 'Rotational Speed' is also missing when we have a functional device
+        # that's a SSD, so we need to distinguish the two cases.
+        if NOT_AVAILABLE_MESSAGE in disk_name:
+            rpm = Disk.RPM_UNKNOWN
+        else:
+            rpm = int(hp_disk.get('Rotational Speed',
+                                  Disk.RPM_NON_ROTATING_MEDIUM))
         link_type = _disk_link_type_of(hp_disk)
 
         return Disk(
@@ -863,7 +884,8 @@ def pool_member_info(self, pool, flags=Client.FLAG_RSVD):
                     elif array_key_name.startswith("physicaldrive"):
                         hp_disk = ctrl_data[key_name][array_key_name]
                         if hp_disk['Drive Type'] == 'Data Drive':
-                            disk_ids.append(hp_disk['Serial Number'])
+                            disk_ids.append(hp_disk.get('Serial Number',
+                                                        NOT_AVAILABLE_MESSAGE))
                 break
 
         if len(disk_ids) == 0: