win_pagefile - Fix idempotency when same settings as current (#57893)

* win_pagefile - Fix idempotency when same settings as current

* Fix tests and code

* Fix problem with system managed

* Fix again systemmanaged detection

* Change check of systemmanged in creation

* Fix readability and wrong flag for test

changelogs/fragments/win_pagefile-Fix-idempotency-when-same-settings-as-current.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - "win_pagefile - Fix idempotency when same settings as current (https://github.com/ansible/ansible/issues/57836)"

lib/ansible/modules/windows/win_pagefile.ps1

@@ -95,8 +95,10 @@ if ($state -eq "absent") {
         Fail-Json $result "Unable to access '${drive}:' drive"
     }
 
+    $curPagefile = Get-Pagefile $fullPath
+
     # Set pagefile
-    if ($null -eq (Get-Pagefile $fullPath)) {
+    if ($null -eq $curPagefile) {
         try {
             $pagefile = Set-WmiInstance -Class Win32_PageFileSetting -Arguments @{name = $fullPath; InitialSize = 0; MaximumSize = 0} -WhatIf:$check_mode
         } catch {
@@ -129,6 +131,40 @@ if ($state -eq "absent") {
             }
         }
         $result.changed = $true
+    }else
+    {
+        $CurPageFileSystemManaged = (Get-CimInstance -ClassName win32_Pagefile -Property 'System' -Filter "name='$($fullPath.Replace('\','\\'))'").System
+        if ((-not $check_mode) -and 
+            -not ($systemManaged -or $CurPageFileSystemManaged) -and 
+            (   ($curPagefile.InitialSize -ne $initialSize) -or 
+                ($curPagefile.maximumSize -ne $maximumSize)))
+        {
+            $curPagefile.InitialSize = $initialSize
+            $curPagefile.MaximumSize = $maximumSize
+            try {
+                $curPagefile.Put() | out-null
+            } catch {
+                $originalExceptionMessage = $($_.Exception.Message)
+                # Try workaround before failing
+                try {
+                    Remove-Pagefile $fullPath -whatif:$check_mode
+                } catch {
+                    Fail-Json $result "Failed to remove pagefile before workaround $($_.Exception.Message) Original exception: $originalExceptionMessage"
+                }
+                try {
+                    $pagingFilesValues = (Get-ItemProperty "HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management").PagingFiles
+                } catch {
+                    Fail-Json $result "Failed to get pagefile settings from the registry for workaround $($_.Exception.Message) Original exception: $originalExceptionMessage"
+                }
+                $pagingFilesValues += "$fullPath $initialSize $maximumSize"
+                try {
+                    Set-ItemProperty "HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" "PagingFiles" $pagingFilesValues
+                } catch {
+                    Fail-Json $result "Failed to set pagefile settings to the registry for workaround $($_.Exception.Message) Original exception: $originalExceptionMessage"
+                }
+            }
+            $result.changed = $true
+        }
     }
 } elseif ($state -eq "query") {
     $result.pagefiles = @()

test/integration/targets/win_pagefile/tasks/main.yml

@@ -164,6 +164,21 @@
     that:
     - c_pagefile_override.changed == true
 
+ # Test 7: Test idempotent
+- name: Set c pagefile 1024-1024, idempotent
+  win_pagefile:
+    drive: C
+    initial_size: 1024
+    maximum_size: 1024
+    override: no
+    state: present
+  register: c_pagefile_idempotent
+
+- name: Test set c pagefile idempotent
+  assert:
+    that:
+    - c_pagefile_idempotent.changed == false
+
 - name: Query all pagefiles
   win_pagefile:
     state: query