allow availability recheck for external storages

apps/files_external/lib/config/configadapter.php

@@ -23,6 +23,7 @@
 
 namespace OCA\Files_External\Config;
 
+use OC\Files\Storage\Wrapper\Availability;
 use OCA\Files_external\Migration\StorageMigrator;
 use OCP\Files\Storage;
 use OC\Files\Mount\MountPoint;
@@ -132,7 +133,7 @@ class ConfigAdapter implements IMountProvider {
 
 			try {
 				$availability = $impl->getAvailability();
-				if (!$availability['available']) {
+				if (!$availability['available'] && !Availability::shouldRecheck($availability)) {
 					$impl = new FailedStorage(['exception' => null]);
 				}
 			} catch (\Exception $e) {

lib/private/files/storage/wrapper/availability.php

@@ -29,6 +29,16 @@ namespace OC\Files\Storage\Wrapper;
 class Availability extends Wrapper {
 	const RECHECK_TTL_SEC = 600; // 10 minutes
 
+	public static function shouldRecheck($availability) {
+		if (!$availability['available']) {
+			// trigger a recheck if TTL reached
+			if ((time() - $availability['last_checked']) > self::RECHECK_TTL_SEC) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 	/**
 	 * @return bool
 	 */
@@ -47,11 +57,8 @@ class Availability extends Wrapper {
 	 */
 	private function isAvailable() {
 		$availability = $this->getAvailability();
-		if (!$availability['available']) {
-			// trigger a recheck if TTL reached
-			if ((time() - $availability['last_checked']) > self::RECHECK_TTL_SEC) {
-				return $this->updateAvailability();
-			}
+		if (self::shouldRecheck($availability)) {
+			return $this->updateAvailability();
 		}
 		return $availability['available'];
 	}