Remove old workaround for resolving enclosures (#18)

A workaround to resolve same enclosures was added to support old
broken kernels (e.g. 3.10.0-327.36.3.el7). That workaround is not
needed and actually doesn't work with some virtual enclosure.
This patch removes the workaround from sas_devices and udev alias
scripts.

Closes #18

sasutils/cli/sas_devices.py

@@ -134,20 +134,7 @@ def _print_lu_devlist(self, lu, devlist, maxpaths=None):
         print(self.FMT_DEVLIST_VERB.format(**info))
 
     def print_end_devices(self, sysfsnode):
-
-        # NOTE: Unfortunately, we cannot always rely on sysfs block device
-        # 'enclosure_device' symlink to the array device (at least not on
-        # 3.10.0-327.36.3.el7). We have to do the enclosure lookup ourselves
-        # as a workaround.
-
-        # Preload enclosure dict (sas_address -> EnclosureDevice)
-        enclosures = {}
-        for encl in sysfs.node('class').node('enclosure'):
-            encldev = EnclosureDevice(encl.node('device'))
-            enclosures[encldev.attrs.sas_address] = encldev
-
         # This code is ugly and should be rewritten...
-
         devmap = {}  # LU -> list of (SASEndDevice, SCSIDevice)
 
         for node in sysfsnode:
@@ -187,13 +174,6 @@ def print_end_devices(self, sysfsnode):
                 else:
                     print("Warning: no enclosure symlink set for %s in %s" %
                           (blk.name, blk.scsi_device.sysfsnode.path))
-                    sasdev = sas_ed.sas_device
-                    try:
-                        encs.add(enclosures[sasdev.attrs.enclosure_identifier])
-                    except (AttributeError, KeyError):
-                        # not an array device?
-                        print("Warning: %s not an array device (%s)" %
-                              (blk.name, sasdev.sysfsnode.path))
             if not encs:
                 orphans.append((lu, dev_list))
                 continue
@@ -246,14 +226,6 @@ def enclosure_finder(arg):
                         # 'enclosure_device' symlink is present
                         # (preferred method)
                         _encl = _blk.array_device.enclosure
-                    else:
-                        # 'enclosure_device' symlink is absent: use workaround
-                        try:
-                            _sasdev = _sas_ed.sas_device
-                            _encl = enclosures[_sasdev.attrs.enclosure_identifier]
-                        except (AttributeError, KeyError):
-                            # not an array device
-                            continue
                     if _encl in encset:
                         return True
                 return False

sasutils/cli/sas_mpath_snic_alias.py

@@ -49,17 +49,6 @@ def sas_mpath_snic_alias(dmdev):
     #   sanity: check if the bay identifers are the same
     #   find common snic part and return result
 
-    # NOTE: Unfortunately, we cannot always rely on sysfs block device
-    # 'enclosure_device' symlink to the array device (at least not on
-    # 3.10.0-327.36.3.el7). We have to do the enclosure lookup ourselves
-    # as a workaround.
-
-    # Preload enclosure dict (sas_address -> EnclosureDevice)
-    enclosures = {}
-    for encl in sysfs.node('class').node('enclosure'):
-        encldev = EnclosureDevice(encl.node('device'))
-        enclosures[encldev.attrs.sas_address] = encldev
-
     snics = []
     bayids = []
 
@@ -71,26 +60,15 @@ def sas_mpath_snic_alias(dmdev):
         sasdev = blkdev.end_device.sas_device
         wwid = '%s_unknown' % dmdev
 
-        if blkdev.array_device:
-            # 'enclosure_device' symlink is present (preferred method)
-            # Use array_device and enclosure to retrieve the ses sg name
-            ses_sg = blkdev.array_device.enclosure.scsi_generic.sg_name
-            try:
-                # Use the wwid of the enclosure to create enclosure-specifc
-                # aliases if an enclosure nickname is not set
-                wwid = blkdev.array_device.enclosure.attrs.wwid
-            except AttributeError:
-                pass
-        else:
-            # 'enclosure_device' symlink is absent: use workaround (see NOTE)
-            try:
-                encl = enclosures[sasdev.attrs.enclosure_identifier]
-                ses_sg = encl.scsi_generic.sg_name
-            except KeyError:
-                # definitively not an array device
-                logging.warning('%s not an array device (%s)', blkdev.name,
-                                blkdev.sysfsnode.path)
-                continue
+        # 'enclosure_device' symlink is present (preferred method)
+        # Use array_device and enclosure to retrieve the ses sg name
+        ses_sg = blkdev.array_device.enclosure.scsi_generic.sg_name
+        try:
+            # Use the wwid of the enclosure to create enclosure-specifc
+            # aliases if an enclosure nickname is not set
+            wwid = blkdev.array_device.enclosure.attrs.wwid
+        except AttributeError:
+            pass
 
         # Retrieve bay_identifier from matching sas_device
         bayids.append(int(sasdev.attrs.bay_identifier))

sasutils/cli/sas_sd_snic_alias.py

@@ -40,43 +40,21 @@
 def sas_sd_snic_alias(blkdev):
     """Use sasutils library to get the alias name from the block device."""
 
-    # NOTE: Unfortunately, we cannot always rely on sysfs block device
-    # 'enclosure_device' symlink to the array device (at least not on
-    # 3.10.0-327.36.3.el7). We have to do the enclosure lookup ourselves
-    # as a workaround.
-
-    # Preload enclosure dict (sas_address -> EnclosureDevice)
-    enclosures = {}
-    for encl in sysfs.node('class').node('enclosure'):
-        encldev = EnclosureDevice(encl.node('device'))
-        enclosures[encldev.attrs.sas_address] = encldev
-
     # Instantiate SASBlockDevice object from block device sysfs node
     #   eg. /sys/block/sdx/device
     blkdev = SASBlockDevice(sysfs.node('block').node(blkdev).node('device'))
     sasdev = blkdev.end_device.sas_device
     wwid = '%s_unknown' % blkdev.name
 
-    if blkdev.array_device:
-        # 'enclosure_device' symlink is present (preferred method)
-        # Use array_device and enclosure to retrieve the ses sg name
-        ses_sg = blkdev.array_device.enclosure.scsi_generic.sg_name
-        try:
-            # Use the wwid of the enclosure to create enclosure-specifc
-            # aliases if an enclosure nickname is not set
-            wwid = blkdev.array_device.enclosure.attrs.wwid
-        except AttributeError:
-            pass
-    else:
-        # 'enclosure_device' symlink is absent: use workaround (see NOTE)
-        try:
-            encl = enclosures[sasdev.attrs.enclosure_identifier]
-            ses_sg = encl.scsi_generic.sg_name
-        except KeyError:
-            # not an array device
-            logging.warning('%s not an array device (%s)', blkdev.name,
-                            blkdev.sysfsnode.path)
-            raise
+    # 'enclosure_device' symlink is present (preferred method)
+    # Use array_device and enclosure to retrieve the ses sg name
+    ses_sg = blkdev.array_device.enclosure.scsi_generic.sg_name
+    try:
+        # Use the wwid of the enclosure to create enclosure-specifc
+        # aliases if an enclosure nickname is not set
+        wwid = blkdev.array_device.enclosure.attrs.wwid
+    except AttributeError:
+        pass
 
     # Retrieve bay_identifier from matching sas_device
     bay = int(sasdev.attrs.bay_identifier)