Merge branch 'bugfix/nvs_flash_space_reclaim_v5.5' into 'release/v5.5'

fix(nvs_flash): Fixed sequence of page state changes to allow correct recovery when power is interrupted (v5.5)

See merge request espressif/esp-idf!44936

components/nvs_flash/src/nvs_pagemanager.cpp

@@ -163,22 +163,25 @@ esp_err_t PageManager::requestNewPage()
         return ESP_ERR_NVS_NOT_ENOUGH_SPACE;
     }
 
-    esp_err_t err = activatePage();
+    Page* erasedPage = maxUnusedItemsPageIt;
+
+#ifndef NDEBUG
+    size_t usedEntries = erasedPage->getUsedEntryCount();
+#endif
+    esp_err_t err = erasedPage->markFreeing();
+    if (err != ESP_OK) {
+        return err;
+    }
+
+    // Activating a new page first when markFreeing is done. The data recovery from power loss will be
+    // driven by the existence of the (transitional) FREEING state of a page.
+    err = activatePage();
     if (err != ESP_OK) {
         return err;
     }
 
     Page* newPage = &mPageList.back();
 
-    Page* erasedPage = maxUnusedItemsPageIt;
-
-#ifndef NDEBUG
-    size_t usedEntries = erasedPage->getUsedEntryCount();
-#endif
-    err = erasedPage->markFreeing();
-    if (err != ESP_OK) {
-        return err;
-    }
     err = erasedPage->copyItems(*newPage);
     if (err != ESP_OK && err != ESP_ERR_NVS_NOT_FOUND) {
         return err;