update capacity filter during extend share

use size increase to calculate provisioned_ratio during
extend share.

Closes-Bug: #1968891

Change-Id: I2d4903d6a2fda588b126a062c755db2fa2b09cdb

manila/scheduler/filters/capacity.py

@@ -32,7 +32,9 @@ class CapacityFilter(base_host.BaseHostFilter):
 
     def host_passes(self, host_state, filter_properties):
         """Return True if host has sufficient capacity."""
-        share_size = filter_properties.get('size', 0)
+        size_increase = filter_properties.get('size_increase')
+        share_size = size_increase if size_increase else filter_properties.get(
+            'size', 0)
 
         if host_state.free_capacity_gb is None:
             # Fail Safe

manila/scheduler/manager.py

@@ -333,12 +333,16 @@ class SchedulerManager(manager.Manager):
 
         share = db.share_get(context, share_id)
         try:
+            size_increase = int(new_size) - share['size']
+            if filter_properties:
+                filter_properties['size_increase'] = size_increase
+            else:
+                filter_properties = {'size_increase': size_increase}
             target_host = self.driver.host_passes_filters(
                 context,
                 share['host'],
                 request_spec, filter_properties)
-            target_host.consume_from_share(
-                {'size': int(new_size) - share['size']})
+            target_host.consume_from_share({'size': size_increase})
             share_rpcapi.ShareAPI().extend_share(context, share, new_size,
                                                  reservations)
         except exception.NoValidHost as ex:

releasenotes/notes/bug-1968891-fix-scheduler-capacity-filter-fails-to-pass-when-extending-share-6b60799e7aa41e19.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    `Launchpad bug 1968891 <https://bugs.launchpad.net/manila/+bug/1968891>`_
+    has been fixed. scheduler will use size increase rather than share size
+    to calculate provisioned_ratio when extending share.