From 1423912a67c1c98e09991957519feea9f5dfd64f Mon Sep 17 00:00:00 2001
From: Robin Appelman <robin@icewind.nl>
Date: Mon, 10 May 2021 17:34:10 +0200
Subject: [PATCH] better cleanup of filecache when deleting an external storage

this way it can delete the cache entries even with per-user credentials

Signed-off-by: Robin Appelman <robin@icewind.nl>
---
 .../lib/Service/StoragesService.php           | 39 +-----------------
 lib/private/Files/Cache/Storage.php           | 40 +++++++++++++++++++
 2 files changed, 41 insertions(+), 38 deletions(-)

diff --git a/apps/files_external/lib/Service/StoragesService.php b/apps/files_external/lib/Service/StoragesService.php
index 63f0c5d52c5ab..334b1c5041a55 100644
--- a/apps/files_external/lib/Service/StoragesService.php
+++ b/apps/files_external/lib/Service/StoragesService.php
@@ -479,44 +479,7 @@ public function removeStorage($id) {
 		$this->triggerHooks($deletedStorage, Filesystem::signal_delete_mount);
 
 		// delete oc_storages entries and oc_filecache
-		try {
-			$rustyStorageId = $this->getRustyStorageIdFromConfig($deletedStorage);
-			\OC\Files\Cache\Storage::remove($rustyStorageId);
-		} catch (\Exception $e) {
-			// can happen either for invalid configs where the storage could not
-			// be instantiated or whenever $user vars where used, in which case
-			// the storage id could not be computed
-			\OC::$server->getLogger()->logException($e, [
-				'level' => ILogger::ERROR,
-				'app' => 'files_external',
-			]);
-		}
-	}
-
-	/**
-	 * Returns the rusty storage id from oc_storages from the given storage config.
-	 *
-	 * @param StorageConfig $storageConfig
-	 * @return string rusty storage id
-	 */
-	private function getRustyStorageIdFromConfig(StorageConfig $storageConfig) {
-		// if any of the storage options contains $user, it is not possible
-		// to compute the possible storage id as we don't know which users
-		// mounted it already (and we certainly don't want to iterate over ALL users)
-		foreach ($storageConfig->getBackendOptions() as $value) {
-			if (strpos($value, '$user') !== false) {
-				throw new \Exception('Cannot compute storage id for deletion due to $user vars in the configuration');
-			}
-		}
-
-		// note: similar to ConfigAdapter->prepateStorageConfig()
-		$storageConfig->getAuthMechanism()->manipulateStorageConfig($storageConfig);
-		$storageConfig->getBackend()->manipulateStorageConfig($storageConfig);
-
-		$class = $storageConfig->getBackend()->getStorageClass();
-		$storageImpl = new $class($storageConfig->getBackendOptions());
-
-		return $storageImpl->getId();
+		\OC\Files\Cache\Storage::cleanByMountId($id);
 	}
 
 	/**
diff --git a/lib/private/Files/Cache/Storage.php b/lib/private/Files/Cache/Storage.php
index 173091f53b059..0ce9032414444 100644
--- a/lib/private/Files/Cache/Storage.php
+++ b/lib/private/Files/Cache/Storage.php
@@ -29,6 +29,7 @@
 
 namespace OC\Files\Cache;
 
+use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\Files\Storage\IStorage;
 use Psr\Log\LoggerInterface;
 
@@ -219,4 +220,43 @@ public static function remove($storageId) {
 			$query->execute();
 		}
 	}
+
+	/**
+	 * remove the entry for the storage by the mount id
+	 *
+	 * @param int $mountId
+	 */
+	public static function cleanByMountId(int $mountId) {
+		$db = \OC::$server->getDatabaseConnection();
+
+		try {
+			$db->beginTransaction();
+			
+			$query = $db->getQueryBuilder();
+			$query->select('storage_id')
+				->from('mounts')
+				->where($query->expr()->eq('mount_id', $query->createNamedParameter($mountId, IQueryBuilder::PARAM_INT)));
+			$storageIds = $query->executeQuery()->fetchAll(\PDO::FETCH_COLUMN);
+
+			$query = $db->getQueryBuilder();
+			$query->delete('filecache')
+				->where($query->expr()->in('storage', $query->createNamedParameter($storageIds, IQueryBuilder::PARAM_INT_ARRAY)));
+			$query->executeStatement();
+
+			$query = $db->getQueryBuilder();
+			$query->delete('storages')
+				->where($query->expr()->eq('id', $query->createNamedParameter($storageIds, IQueryBuilder::PARAM_INT_ARRAY)));
+			$query->executeStatement();
+
+			$query = $db->getQueryBuilder();
+			$query->delete('mounts')
+				->where($query->expr()->eq('mount_id', $query->createNamedParameter($mountId, IQueryBuilder::PARAM_INT)));
+			$query->executeStatement();
+
+			$db->commit();
+		} catch (\Exception $e) {
+			$db->rollBack();
+			throw $e;
+		}
+	}
 }