From 6990100e6ed6d1efe48e2688331df5ce364f9fd5 Mon Sep 17 00:00:00 2001
From: Robin Appelman <icewind@owncloud.com>
Date: Thu, 3 Mar 2016 14:19:34 +0100
Subject: [PATCH 1/2] allow availability recheck for external storages

---
 .../files_external/lib/config/configadapter.php |  3 ++-
 .../files/storage/wrapper/availability.php      | 17 ++++++++++++-----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/apps/files_external/lib/config/configadapter.php b/apps/files_external/lib/config/configadapter.php
index 51c2debd72..f097d55a31 100644
--- a/apps/files_external/lib/config/configadapter.php
+++ b/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) {
diff --git a/lib/private/files/storage/wrapper/availability.php b/lib/private/files/storage/wrapper/availability.php
index 55ddb0d5e8..0ed31ba854 100644
--- a/lib/private/files/storage/wrapper/availability.php
+++ b/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'];
 	}

From 4255dd2b396050e757f77db86063f0f1420a87d5 Mon Sep 17 00:00:00 2001
From: Vincent Petry <pvince81@owncloud.com>
Date: Wed, 2 Mar 2016 12:17:14 +0100
Subject: [PATCH 2/2] Properly set exception in FailedStorage

---
 apps/files_external/lib/config/configadapter.php | 5 ++++-
 apps/files_external/lib/failedstorage.php        | 3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/apps/files_external/lib/config/configadapter.php b/apps/files_external/lib/config/configadapter.php
index f097d55a31..d85e0f4563 100644
--- a/apps/files_external/lib/config/configadapter.php
+++ b/apps/files_external/lib/config/configadapter.php
@@ -35,6 +35,7 @@ use OCA\Files_external\Service\UserStoragesService;
 use OCA\Files_External\Service\UserGlobalStoragesService;
 use OCA\Files_External\Lib\StorageConfig;
 use OCA\Files_External\Lib\FailedStorage;
+use OCP\Files\StorageNotAvailableException;
 
 /**
  * Make the old files_external config work with the new public mount config api
@@ -134,7 +135,9 @@ class ConfigAdapter implements IMountProvider {
 			try {
 				$availability = $impl->getAvailability();
 				if (!$availability['available'] && !Availability::shouldRecheck($availability)) {
-					$impl = new FailedStorage(['exception' => null]);
+					$impl = new FailedStorage([
+						'exception' => new StorageNotAvailableException('Storage with mount id ' . $storage->getId() . ' is not available')
+					]);
 				}
 			} catch (\Exception $e) {
 				// propagate exception into filesystem
diff --git a/apps/files_external/lib/failedstorage.php b/apps/files_external/lib/failedstorage.php
index 928d09e20f..20cf43d74b 100644
--- a/apps/files_external/lib/failedstorage.php
+++ b/apps/files_external/lib/failedstorage.php
@@ -39,6 +39,9 @@ class FailedStorage extends Common {
 	 */
 	public function __construct($params) {
 		$this->e = $params['exception'];
+		if (!$this->e) {
+			throw new \InvalidArgumentException('Missing "exception" argument in FailedStorage constructor');
+		}
 	}
 
 	public function getId() {