Use storage filter when fetching previews to cleanup

Signed-off-by: Julius Härtl <jus@bitgrid.net>

lib/private/Files/AppData/AppData.php

@@ -79,7 +79,7 @@ class AppData implements IAppData {
 		return 'appdata_' . $instanceId;
 	}
 
-	private function getAppDataRootFolder(): Folder {
+	protected function getAppDataRootFolder(): Folder {
 		$name = $this->getAppDataFolderName();
 
 		try {

lib/private/Preview/BackgroundCleanupJob.php

@@ -134,6 +134,7 @@ class BackgroundCleanupJob extends TimedJob {
 			))
 			->where(
 				$qb->expr()->andX(
+					$qb->expr()->eq('a.storage', $qb->createNamedParameter($this->previewFolder->getStorageId())),
 					$qb->expr()->isNull('b.fileid'),
 					$qb->expr()->like('a.path', $qb->createNamedParameter($like)),
 					$qb->expr()->eq('a.mimetype', $qb->createNamedParameter($this->mimeTypeLoader->getId('httpd/unix-directory')))

lib/private/Preview/Storage/Root.php

@@ -85,4 +85,8 @@ class Root extends AppData {
 	public static function getInternalFolder(string $name): string {
 		return implode('/', str_split(substr(md5($name), 0, 7))) . '/' . $name;
 	}
+
+	public function getStorageId(): int {
+		return $this->getAppDataRootFolder()->getStorage()->getCache()->getNumericStorageId();
+	}
 }