Fix sharedstorage recursion hell

apps/files_sharing/lib/SharedMount.php

@@ -234,4 +234,13 @@ public function getShare() {
 	public function getStorageRootId() {
 		return $this->getShare()->getNodeId();
 	}
+
+	public function getStorageNumericId() {
+		$query = \OC::$server->getDatabaseConnection()->getQueryBuilder();
+		$query->select('storage')
+			->from('filecache')
+			->where($query->expr()->eq('fileid', $query->createNamedParameter($this->getStorageRootId())));
+
+		return $query->execute()->fetchColumn();
+	}
 }

apps/files_sharing/lib/sharedstorage.php

@@ -37,6 +37,7 @@
 use OCP\Files\Cache\ICacheEntry;
 use OCP\Files\Storage\IStorage;
 use OCP\Lock\ILockingProvider;
+use OC\Files\Storage\FailedStorage;
 
 /**
  * Convert target path to source path and pass the function call to the correct storage provider
@@ -82,13 +83,9 @@ public function __construct($arguments) {
 
 		$this->user = $arguments['user'];
 
-		Filesystem::initMountPoints($this->superShare->getShareOwner());
-		$sourcePath = $this->ownerView->getPath($this->superShare->getNodeId());
-		list($storage, $internalPath) = $this->ownerView->resolvePath($sourcePath);
-
 		parent::__construct([
-			'storage' => $storage,
-			'root' => $internalPath,
+			'storage' => null, // init later
+			'root' => null, // init later
 		]);
 	}
 
@@ -99,12 +96,17 @@ private function init() {
 		$this->initialized = true;
 		try {
 			Filesystem::initMountPoints($this->superShare->getShareOwner());
-			$sourcePath = $this->ownerView->getPath($this->superShare->getNodeId());
+			$sourcePath = $this->ownerView->getPath($this->superShare->getNodeId(), false);
 			list($this->sourceStorage, $sourceInternalPath) = $this->ownerView->resolvePath($sourcePath);
 			$this->sourceRootInfo = $this->sourceStorage->getCache()->get($sourceInternalPath);
+			// adjust jail
+			$this->rootPath = $sourceInternalPath;
+
 		} catch (\Exception $e) {
+			$this->sourceStorage = new FailedStorage(['exception' => $e]);
 			$this->logger->logException($e);
 		}
+		$this->storage = $this->sourceStorage;
 	}
 
 	/**
@@ -311,7 +313,7 @@ public function getItemType() {
 
 	public function getCache($path = '', $storage = null) {
 		$this->init();
-		if (is_null($this->sourceStorage)) {
+		if (is_null($this->sourceStorage) || $this->sourceStorage instanceof FailedStorage) {
 			return new FailedCache(false);
 		}
 		if (!$storage) {
@@ -439,4 +441,9 @@ public function file_put_contents($path, $data) {
 		return parent::file_put_contents($path, $data);
 	}
 
+	public function getWrapperStorage() {
+		$this->init();
+
+		return $this->sourceStorage;
+	}
 }

lib/private/Files/Config/LazyStorageMountInfo.php

@@ -47,11 +47,15 @@ public function __construct(IUser $user, IMountPoint $mount) {
 	 */
 	public function getStorageId() {
 		if (!$this->storageId) {
-			$storage = $this->mount->getStorage();
-			if (!$storage) {
-				return -1;
+			if (method_exists($this->mount, 'getStorageNumericId')) {
+				$this->storageId = $this->mount->getStorageNumericId();
+			} else {
+				$storage = $this->mount->getStorage();
+				if (!$storage) {
+					return -1;
+				}
+				$this->storageId = $storage->getStorageCache()->getNumericId();
 			}
-			$this->storageId = $storage->getStorageCache()->getNumericId();
 		}
 		return parent::getStorageId();
 	}