Merge pull request #31265 from nextcloud/fs-limited-setup

Fine grained filesystem setup

14 files changed, 498 insertions, 42 deletions

diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index feaa60a4ca6..79035f2e42a 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -260,6 +260,7 @@ return array(
     'OCP\\Files\\Events\\FileCacheUpdated' => $baseDir . '/lib/public/Files/Events/FileCacheUpdated.php',
     'OCP\\Files\\Events\\FileScannedEvent' => $baseDir . '/lib/public/Files/Events/FileScannedEvent.php',
     'OCP\\Files\\Events\\FolderScannedEvent' => $baseDir . '/lib/public/Files/Events/FolderScannedEvent.php',
+    'OCP\\Files\\Events\\InvalidateMountCacheEvent' => $baseDir . '/lib/public/Files/Events/InvalidateMountCacheEvent.php',
     'OCP\\Files\\Events\\NodeAddedToCache' => $baseDir . '/lib/public/Files/Events/NodeAddedToCache.php',
     'OCP\\Files\\Events\\NodeRemovedFromCache' => $baseDir . '/lib/public/Files/Events/NodeRemovedFromCache.php',
     'OCP\\Files\\Events\\Node\\AbstractNodeEvent' => $baseDir . '/lib/public/Files/Events/Node/AbstractNodeEvent.php',
@@ -1141,6 +1142,7 @@ return array(
     'OC\\Files\\Node\\HookConnector' => $baseDir . '/lib/private/Files/Node/HookConnector.php',
     'OC\\Files\\Node\\LazyFolder' => $baseDir . '/lib/private/Files/Node/LazyFolder.php',
     'OC\\Files\\Node\\LazyRoot' => $baseDir . '/lib/private/Files/Node/LazyRoot.php',
+    'OC\\Files\\Node\\LazyUserFolder' => $baseDir . '/lib/private/Files/Node/LazyUserFolder.php',
     'OC\\Files\\Node\\Node' => $baseDir . '/lib/private/Files/Node/Node.php',
     'OC\\Files\\Node\\NonExistingFile' => $baseDir . '/lib/private/Files/Node/NonExistingFile.php',
     'OC\\Files\\Node\\NonExistingFolder' => $baseDir . '/lib/private/Files/Node/NonExistingFolder.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index 795742f87f8..4a4c886a082 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -289,6 +289,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OCP\\Files\\Events\\FileCacheUpdated' => __DIR__ . '/../../..' . '/lib/public/Files/Events/FileCacheUpdated.php',
         'OCP\\Files\\Events\\FileScannedEvent' => __DIR__ . '/../../..' . '/lib/public/Files/Events/FileScannedEvent.php',
         'OCP\\Files\\Events\\FolderScannedEvent' => __DIR__ . '/../../..' . '/lib/public/Files/Events/FolderScannedEvent.php',
+        'OCP\\Files\\Events\\InvalidateMountCacheEvent' => __DIR__ . '/../../..' . '/lib/public/Files/Events/InvalidateMountCacheEvent.php',
         'OCP\\Files\\Events\\NodeAddedToCache' => __DIR__ . '/../../..' . '/lib/public/Files/Events/NodeAddedToCache.php',
         'OCP\\Files\\Events\\NodeRemovedFromCache' => __DIR__ . '/../../..' . '/lib/public/Files/Events/NodeRemovedFromCache.php',
         'OCP\\Files\\Events\\Node\\AbstractNodeEvent' => __DIR__ . '/../../..' . '/lib/public/Files/Events/Node/AbstractNodeEvent.php',
@@ -1170,6 +1171,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Files\\Node\\HookConnector' => __DIR__ . '/../../..' . '/lib/private/Files/Node/HookConnector.php',
         'OC\\Files\\Node\\LazyFolder' => __DIR__ . '/../../..' . '/lib/private/Files/Node/LazyFolder.php',
         'OC\\Files\\Node\\LazyRoot' => __DIR__ . '/../../..' . '/lib/private/Files/Node/LazyRoot.php',
+        'OC\\Files\\Node\\LazyUserFolder' => __DIR__ . '/../../..' . '/lib/private/Files/Node/LazyUserFolder.php',
         'OC\\Files\\Node\\Node' => __DIR__ . '/../../..' . '/lib/private/Files/Node/Node.php',
         'OC\\Files\\Node\\NonExistingFile' => __DIR__ . '/../../..' . '/lib/private/Files/Node/NonExistingFile.php',
         'OC\\Files\\Node\\NonExistingFolder' => __DIR__ . '/../../..' . '/lib/private/Files/Node/NonExistingFolder.php',
diff --git a/lib/private/Files/Config/MountProviderCollection.php b/lib/private/Files/Config/MountProviderCollection.php
index cd8a2a2e29f..2b0acf7d69d 100644
--- a/lib/private/Files/Config/MountProviderCollection.php
+++ b/lib/private/Files/Config/MountProviderCollection.php
@@ -75,16 +75,15 @@ class MountProviderCollection implements IMountProviderCollection, Emitter {
 	}
 
 	/**
-	 * Get all configured mount points for the user
-	 *
-	 * @param \OCP\IUser $user
-	 * @return \OCP\Files\Mount\IMountPoint[]
+	 * @param IUser $user
+	 * @param IMountProvider[] $providers
+	 * @return IMountPoint[]
 	 */
-	public function getMountsForUser(IUser $user) {
+	private function getUserMountsForProviders(IUser $user, array $providers): array {
 		$loader = $this->loader;
 		$mounts = array_map(function (IMountProvider $provider) use ($user, $loader) {
 			return $provider->getMountsForUser($user, $loader);
-		}, $this->providers);
+		}, $providers);
 		$mounts = array_filter($mounts, function ($result) {
 			return is_array($result);
 		});
@@ -94,14 +93,31 @@ class MountProviderCollection implements IMountProviderCollection, Emitter {
 		return $this->filterMounts($user, $mounts);
 	}
 
-	public function addMountForUser(IUser $user, IMountManager $mountManager) {
+	public function getMountsForUser(IUser $user): array {
+		return $this->getUserMountsForProviders($user, $this->providers);
+	}
+
+	public function getUserMountsForProviderClass(IUser $user, string $mountProviderClass): array {
+		$providers = array_filter(
+			$this->providers,
+			fn (IMountProvider $mountProvider) => (get_class($mountProvider) === $mountProviderClass)
+		);
+		return $this->getUserMountsForProviders($user, $providers);
+	}
+
+	public function addMountForUser(IUser $user, IMountManager $mountManager, callable $providerFilter = null) {
 		// shared mount provider gets to go last since it needs to know existing files
 		// to check for name collisions
 		$firstMounts = [];
-		$firstProviders = array_filter($this->providers, function (IMountProvider $provider) {
+		if ($providerFilter) {
+			$providers = array_filter($this->providers, $providerFilter);
+		} else {
+			$providers = $this->providers;
+		}
+		$firstProviders = array_filter($providers, function (IMountProvider $provider) {
 			return (get_class($provider) !== 'OCA\Files_Sharing\MountProvider');
 		});
-		$lastProviders = array_filter($this->providers, function (IMountProvider $provider) {
+		$lastProviders = array_filter($providers, function (IMountProvider $provider) {
 			return (get_class($provider) === 'OCA\Files_Sharing\MountProvider');
 		});
 		foreach ($firstProviders as $provider) {
diff --git a/lib/private/Files/Config/UserMountCache.php b/lib/private/Files/Config/UserMountCache.php
index dc2640361e7..9a5eddc4878 100644
--- a/lib/private/Files/Config/UserMountCache.php
+++ b/lib/private/Files/Config/UserMountCache.php
@@ -89,7 +89,7 @@ class UserMountCache implements IUserMountCache {
 		$this->mountsForUsers = new CappedMemoryCache();
 	}
 
-	public function registerMounts(IUser $user, array $mounts) {
+	public function registerMounts(IUser $user, array $mounts, array $mountProviderClasses = null) {
 		// filter out non-proper storages coming from unit tests
 		$mounts = array_filter($mounts, function (IMountPoint $mount) {
 			return $mount instanceof SharedMount || $mount->getStorage() && $mount->getStorage()->getCache();
@@ -110,6 +110,11 @@ class UserMountCache implements IUserMountCache {
 		$newMounts = array_combine($newMountRootIds, $newMounts);
 
 		$cachedMounts = $this->getMountsForUser($user);
+		if (is_array($mountProviderClasses)) {
+			$cachedMounts = array_filter($cachedMounts, function (ICachedMountInfo $mountInfo) use ($mountProviderClasses) {
+				return in_array($mountInfo->getMountProvider(), $mountProviderClasses);
+			});
+		}
 		$cachedMountRootIds = array_map(function (ICachedMountInfo $mount) {
 			return $mount->getRootId();
 		}, $cachedMounts);
@@ -446,4 +451,39 @@ class UserMountCache implements IUserMountCache {
 		$this->cacheInfoCache = new CappedMemoryCache();
 		$this->mountsForUsers = new CappedMemoryCache();
 	}
+
+	public function getMountForPath(IUser $user, string $path): ICachedMountInfo {
+		$mounts = $this->getMountsForUser($user);
+		$mountPoints = array_map(function (ICachedMountInfo $mount) {
+			return $mount->getMountPoint();
+		}, $mounts);
+		$mounts = array_combine($mountPoints, $mounts);
+
+		$current = $path;
+		// walk up the directory tree until we find a path that has a mountpoint set
+		// the loop will return if a mountpoint is found or break if none are found
+		while (true) {
+			$mountPoint = $current . '/';
+			if (isset($mounts[$mountPoint])) {
+				return $mounts[$mountPoint];
+			} elseif ($current === '') {
+				break;
+			}
+
+			$current = dirname($current);
+			if ($current === '.' || $current === '/') {
+				$current = '';
+			}
+		}
+
+		throw new NotFoundException("No cached mount for path " . $path);
+	}
+
+	public function getMountsInPath(IUser $user, string $path): array {
+		$path = rtrim($path, '/') . '/';
+		$mounts = $this->getMountsForUser($user);
+		return array_filter($mounts, function (ICachedMountInfo $mount) use ($path) {
+			return $mount->getMountPoint() !== $path && strpos($mount->getMountPoint(), $path) === 0;
+		});
+	}
 }
diff --git a/lib/private/Files/Filesystem.php b/lib/private/Files/Filesystem.php
index 9db9252037f..20b44e2736a 100644
--- a/lib/private/Files/Filesystem.php
+++ b/lib/private/Files/Filesystem.php
@@ -46,6 +46,7 @@ use OCP\Files\NotFoundException;
 use OCP\Files\Storage\IStorageFactory;
 use OCP\IUser;
 use OCP\IUserManager;
+use OCP\IUserSession;
 
 class Filesystem {
 
@@ -324,6 +325,18 @@ class Filesystem {
 		if (self::$defaultInstance) {
 			return false;
 		}
+		self::initInternal($root);
+
+		//load custom mount config
+		self::initMountPoints($user);
+
+		return true;
+	}
+
+	public static function initInternal($root) {
+		if (self::$defaultInstance) {
+			return false;
+		}
 		self::getLoader();
 		self::$defaultInstance = new View($root);
 		/** @var IEventDispatcher $eventDispatcher */
@@ -338,9 +351,6 @@ class Filesystem {
 			self::$mounts = \OC::$server->getMountManager();
 		}
 
-		//load custom mount config
-		self::initMountPoints($user);
-
 		self::$loaded = true;
 
 		return true;
@@ -378,6 +388,15 @@ class Filesystem {
 	 * @return View
 	 */
 	public static function getView() {
+		if (!self::$defaultInstance) {
+			/** @var IUserSession $session */
+			$session = \OC::$server->get(IUserSession::class);
+			$user = $session->getUser();
+			if ($user) {
+				$userDir = '/' . $user->getUID() . '/files';
+				self::initInternal($userDir);
+			}
+		}
 		return self::$defaultInstance;
 	}
 
@@ -736,7 +755,7 @@ class Filesystem {
 	 * @return \OC\Files\FileInfo|false False if file does not exist
 	 */
 	public static function getFileInfo($path, $includeMountPoints = true) {
-		return self::$defaultInstance->getFileInfo($path, $includeMountPoints);
+		return self::getView()->getFileInfo($path, $includeMountPoints);
 	}
 
 	/**
diff --git a/lib/private/Files/Mount/Manager.php b/lib/private/Files/Mount/Manager.php
index 66832690363..ecd97760f17 100644
--- a/lib/private/Files/Mount/Manager.php
+++ b/lib/private/Files/Mount/Manager.php
@@ -125,7 +125,7 @@ class Manager implements IMountManager {
 	 * @return IMountPoint[]
 	 */
 	public function findIn(string $path): array {
-		$this->setupManager->setupForPath($path);
+		$this->setupManager->setupForPath($path, true);
 		$path = $this->formatPath($path);
 
 		if (isset($this->inPathCache[$path])) {
diff --git a/lib/private/Files/Node/LazyFolder.php b/lib/private/Files/Node/LazyFolder.php
index bfdaeeccff7..45451e5c53c 100644
--- a/lib/private/Files/Node/LazyFolder.php
+++ b/lib/private/Files/Node/LazyFolder.php
@@ -25,6 +25,8 @@ declare(strict_types=1);
  */
 namespace OC\Files\Node;
 
+use OCP\Constants;
+
 /**
  * Class LazyFolder
  *
@@ -40,13 +42,16 @@ class LazyFolder implements \OCP\Files\Folder {
 	/** @var LazyFolder | null */
 	protected $folder = null;
 
+	protected array $data;
+
 	/**
 	 * LazyFolder constructor.
 	 *
 	 * @param \Closure $folderClosure
 	 */
-	public function __construct(\Closure $folderClosure) {
+	public function __construct(\Closure $folderClosure, array $data = []) {
 		$this->folderClosure = $folderClosure;
+		$this->data = $data;
 	}
 
 	/**
@@ -181,6 +186,9 @@ class LazyFolder implements \OCP\Files\Folder {
 	 * @inheritDoc
 	 */
 	public function getPath() {
+		if (isset($this->data['path'])) {
+			return $this->data['path'];
+		}
 		return $this->__call(__FUNCTION__, func_get_args());
 	}
 
@@ -230,6 +238,9 @@ class LazyFolder implements \OCP\Files\Folder {
 	 * @inheritDoc
 	 */
 	public function getPermissions() {
+		if (isset($this->data['permissions'])) {
+			return $this->data['permissions'];
+		}
 		return $this->__call(__FUNCTION__, func_get_args());
 	}
 
@@ -237,6 +248,9 @@ class LazyFolder implements \OCP\Files\Folder {
 	 * @inheritDoc
 	 */
 	public function isReadable() {
+		if (isset($this->data['permissions'])) {
+			return ($this->data['permissions'] & Constants::PERMISSION_READ) == Constants::PERMISSION_READ;
+		}
 		return $this->__call(__FUNCTION__, func_get_args());
 	}
 
@@ -244,6 +258,9 @@ class LazyFolder implements \OCP\Files\Folder {
 	 * @inheritDoc
 	 */
 	public function isUpdateable() {
+		if (isset($this->data['permissions'])) {
+			return ($this->data['permissions'] & Constants::PERMISSION_UPDATE) == Constants::PERMISSION_UPDATE;
+		}
 		return $this->__call(__FUNCTION__, func_get_args());
 	}
 
@@ -251,6 +268,9 @@ class LazyFolder implements \OCP\Files\Folder {
 	 * @inheritDoc
 	 */
 	public function isDeletable() {
+		if (isset($this->data['permissions'])) {
+			return ($this->data['permissions'] & Constants::PERMISSION_DELETE) == Constants::PERMISSION_DELETE;
+		}
 		return $this->__call(__FUNCTION__, func_get_args());
 	}
 
@@ -258,6 +278,9 @@ class LazyFolder implements \OCP\Files\Folder {
 	 * @inheritDoc
 	 */
 	public function isShareable() {
+		if (isset($this->data['permissions'])) {
+			return ($this->data['permissions'] & Constants::PERMISSION_SHARE) == Constants::PERMISSION_SHARE;
+		}
 		return $this->__call(__FUNCTION__, func_get_args());
 	}
 
diff --git a/lib/private/Files/Node/LazyUserFolder.php b/lib/private/Files/Node/LazyUserFolder.php
new file mode 100644
index 00000000000..4c9e89ce233
--- /dev/null
+++ b/lib/private/Files/Node/LazyUserFolder.php
@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2022 Robin Appelman <robin@icewind.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\Files\Node;
+
+use OCP\Constants;
+use OCP\Files\IRootFolder;
+use OCP\Files\NotFoundException;
+use OCP\IUser;
+
+class LazyUserFolder extends LazyFolder {
+	private IRootFolder $rootFolder;
+	private IUser $user;
+
+	public function __construct(IRootFolder $rootFolder, IUser $user) {
+		$this->rootFolder = $rootFolder;
+		$this->user = $user;
+		parent::__construct(function () use ($user) {
+			try {
+				return $this->rootFolder->get('/' . $user->getUID() . '/files');
+			} catch (NotFoundException $e) {
+				if (!$this->rootFolder->nodeExists('/' . $user->getUID())) {
+					$this->rootFolder->newFolder('/' . $user->getUID());
+				}
+				return $this->rootFolder->newFolder('/' . $user->getUID() . '/files');
+			}
+		}, [
+			'path' => '/' . $user->getUID() . '/files',
+			'permissions' => Constants::PERMISSION_ALL,
+		]);
+	}
+
+	public function get($path) {
+		return $this->rootFolder->get('/' . $this->user->getUID() . '/files/' . rtrim($path, '/'));
+	}
+}
diff --git a/lib/private/Files/Node/Root.php b/lib/private/Files/Node/Root.php
index 88ac4a31d34..53162737b6f 100644
--- a/lib/private/Files/Node/Root.php
+++ b/lib/private/Files/Node/Root.php
@@ -380,15 +380,20 @@ class Root extends Folder implements IRootFolder {
 		$userId = $userObject->getUID();
 
 		if (!$this->userFolderCache->hasKey($userId)) {
-			\OC\Files\Filesystem::initMountPoints($userId);
-
-			try {
-				$folder = $this->get('/' . $userId . '/files');
-			} catch (NotFoundException $e) {
-				if (!$this->nodeExists('/' . $userId)) {
-					$this->newFolder('/' . $userId);
+			if ($this->mountManager->getSetupManager()->isSetupComplete($userObject)) {
+				try {
+					$folder = $this->get('/' . $userId . '/files');
+					if (!$folder instanceof \OCP\Files\Folder) {
+						throw new \Exception("User folder for $userId exists as a file");
+					}
+				} catch (NotFoundException $e) {
+					if (!$this->nodeExists('/' . $userId)) {
+						$this->newFolder('/' . $userId);
+					}
+					$folder = $this->newFolder('/' . $userId . '/files');
 				}
-				$folder = $this->newFolder('/' . $userId . '/files');
+			} else {
+				$folder = new LazyUserFolder($this, $userObject);
 			}
 
 			$this->userFolderCache->set($userId, $folder);
diff --git a/lib/private/Files/SetupManager.php b/lib/private/Files/SetupManager.php
index 9726fbef428..da50983da32 100644
--- a/lib/private/Files/SetupManager.php
+++ b/lib/private/Files/SetupManager.php
@@ -42,14 +42,23 @@ use OCP\Diagnostics\IEventLogger;
 use OCP\EventDispatcher\IEventDispatcher;
 use OCP\Files\Config\IMountProvider;
 use OCP\Files\Config\IUserMountCache;
+use OCP\Files\Events\InvalidateMountCacheEvent;
 use OCP\Files\Events\Node\FilesystemTornDownEvent;
 use OCP\Files\Mount\IMountManager;
 use OCP\Files\Mount\IMountPoint;
+use OCP\Files\NotFoundException;
 use OCP\Files\Storage\IStorage;
+use OCP\Group\Events\UserAddedEvent;
+use OCP\Group\Events\UserRemovedEvent;
+use OCP\ICache;
+use OCP\ICacheFactory;
+use OCP\IConfig;
 use OCP\IUser;
 use OCP\IUserManager;
 use OCP\IUserSession;
 use OCP\Lockdown\ILockdownManager;
+use OCP\Share\Events\ShareCreatedEvent;
+use Psr\Log\LoggerInterface;
 
 class SetupManager {
 	private bool $rootSetup = false;
@@ -57,11 +66,19 @@ class SetupManager {
 	private MountProviderCollection $mountProviderCollection;
 	private IMountManager $mountManager;
 	private IUserManager $userManager;
+	// List of users for which at least one mount is setup
 	private array $setupUsers = [];
+	// List of users for which all mounts are setup
+	private array $setupUsersComplete = [];
+	/** @var array<string, string[]> */
+	private array $setupUserMountProviders = [];
 	private IEventDispatcher $eventDispatcher;
 	private IUserMountCache $userMountCache;
 	private ILockdownManager $lockdownManager;
 	private IUserSession $userSession;
+	private ICache $cache;
+	private LoggerInterface $logger;
+	private IConfig $config;
 	private bool $listeningForProviders;
 
 	public function __construct(
@@ -72,7 +89,10 @@ class SetupManager {
 		IEventDispatcher $eventDispatcher,
 		IUserMountCache $userMountCache,
 		ILockdownManager $lockdownManager,
-		IUserSession $userSession
+		IUserSession $userSession,
+		ICacheFactory $cacheFactory,
+		LoggerInterface $logger,
+		IConfig $config
 	) {
 		$this->eventLogger = $eventLogger;
 		$this->mountProviderCollection = $mountProviderCollection;
@@ -81,8 +101,21 @@ class SetupManager {
 		$this->eventDispatcher = $eventDispatcher;
 		$this->userMountCache = $userMountCache;
 		$this->lockdownManager = $lockdownManager;
+		$this->logger = $logger;
 		$this->userSession = $userSession;
+		$this->cache = $cacheFactory->createDistributed('setupmanager::');
 		$this->listeningForProviders = false;
+		$this->config = $config;
+
+		$this->setupListeners();
+	}
+
+	private function isSetupStarted(IUser $user): bool {
+		return in_array($user->getUID(), $this->setupUsers, true);
+	}
+
+	public function isSetupComplete(IUser $user): bool {
+		return in_array($user->getUID(), $this->setupUsersComplete, true);
 	}
 
 	private function setupBuiltinWrappers() {
@@ -159,15 +192,33 @@ class SetupManager {
 	 * Setup the full filesystem for the specified user
 	 */
 	public function setupForUser(IUser $user): void {
-		$this->setupRoot();
+		if ($this->isSetupComplete($user)) {
+			return;
+		}
+		$this->setupUsersComplete[] = $user->getUID();
+
+		if (!isset($this->setupUserMountProviders[$user->getUID()])) {
+			$this->setupUserMountProviders[$user->getUID()] = [];
+		}
 
+		$this->setupForUserWith($user, function () use ($user) {
+			$this->mountProviderCollection->addMountForUser($user, $this->mountManager, function (
+				IMountProvider $provider
+			) use ($user) {
+				return !in_array(get_class($provider), $this->setupUserMountProviders[$user->getUID()]);
+			});
+		});
+		$this->afterUserFullySetup($user);
+	}
+
+	/**
+	 * part of the user setup that is run only once per user
+	 */
+	private function oneTimeUserSetup(IUser $user) {
 		if (in_array($user->getUID(), $this->setupUsers, true)) {
 			return;
 		}
 		$this->setupUsers[] = $user->getUID();
-
-		$this->eventLogger->start('setup_fs', 'Setup filesystem');
-
 		$prevLogging = Filesystem::logWarningWhenAddingStorageWrapper(false);
 
 		OC_Hook::emit('OC_Filesystem', 'preSetup', ['user' => $user->getUID()]);
@@ -176,7 +227,7 @@ class SetupManager {
 
 		$userDir = '/' . $user->getUID() . '/files';
 
-		Filesystem::init($user, $userDir);
+		Filesystem::initInternal($userDir);
 
 		if ($this->lockdownManager->canAccessFilesystem()) {
 			// home mounts are handled separate since we need to ensure this is mounted before we call the other mount providers
@@ -187,13 +238,6 @@ class SetupManager {
 				$homeMount->getStorage()->mkdir('');
 				$homeMount->getStorage()->getScanner()->scan('');
 			}
-
-			// Chance to mount for other storages
-			$mounts = $this->mountProviderCollection->addMountForUser($user, $this->mountManager);
-			$mounts[] = $homeMount;
-			$this->userMountCache->registerMounts($user, $mounts);
-
-			$this->listenForNewMountProviders();
 		} else {
 			$this->mountManager->addMount(new MountPoint(
 				new NullStorage([]),
@@ -203,9 +247,46 @@ class SetupManager {
 				new NullStorage([]),
 				'/' . $user->getUID() . '/files'
 			));
+			$this->setupUsersComplete[] = $user->getUID();
+		}
+
+		$this->listenForNewMountProviders();
+	}
+
+	/**
+	 * Final housekeeping after a user has been fully setup
+	 */
+	private function afterUserFullySetup(IUser $user): void {
+		$userRoot = '/' . $user->getUID() . '/';
+		$mounts = $this->mountManager->getAll();
+		$mounts = array_filter($mounts, function (IMountPoint $mount) use ($userRoot) {
+			return strpos($mount->getMountPoint(), $userRoot) === 0;
+		});
+		$this->userMountCache->registerMounts($user, $mounts);
+	}
+
+	/**
+	 * @param IUser $user
+	 * @param IMountPoint $mounts
+	 * @return void
+	 * @throws \OCP\HintException
+	 * @throws \OC\ServerNotAvailableException
+	 */
+	private function setupForUserWith(IUser $user, callable $mountCallback): void {
+		$this->setupRoot();
+
+		if (!$this->isSetupStarted($user)) {
+			$this->oneTimeUserSetup($user);
+		}
+
+		$this->eventLogger->start('setup_fs', 'Setup filesystem');
+
+		if ($this->lockdownManager->canAccessFilesystem()) {
+			$mountCallback();
 		}
 		\OC_Hook::emit('OC_Filesystem', 'post_initMountPoints', ['user' => $user->getUID()]);
 
+		$userDir = '/' . $user->getUID() . '/files';
 		OC_Hook::emit('OC_Filesystem', 'setup', ['user' => $user->getUID(), 'user_dir' => $userDir]);
 
 		$this->eventLogger->end('setup_fs');
@@ -242,7 +323,7 @@ class SetupManager {
 	/**
 	 * Set up the filesystem for the specified path
 	 */
-	public function setupForPath(string $path): void {
+	public function setupForPath(string $path, bool $includeChildren = false): void {
 		if (substr_count($path, '/') < 2) {
 			if ($user = $this->userSession->getUser()) {
 				$this->setupForUser($user);
@@ -264,11 +345,81 @@ class SetupManager {
 			return;
 		}
 
-		$this->setupForUser($user);
+		if ($this->isSetupComplete($user)) {
+			return;
+		}
+
+		// we perform a "cached" setup only after having done the full setup recently
+		// this is also used to trigger a full setup after handling events that are likely
+		// to change the available mounts
+		$cachedSetup = $this->cache->get($user->getUID());
+		if (!$cachedSetup) {
+			$this->setupForUser($user);
+
+			$cacheDuration = $this->config->getSystemValueInt('fs_mount_cache_duration', 5 * 60);
+			if ($cacheDuration > 0) {
+				$this->cache->set($user->getUID(), true, $cacheDuration);
+			}
+			return;
+		}
+
+		if (!isset($this->setupUserMountProviders[$user->getUID()])) {
+			$this->setupUserMountProviders[$user->getUID()] = [];
+		}
+		$setupProviders = &$this->setupUserMountProviders[$user->getUID()];
+		$currentProviders = [];
+
+		try {
+			$cachedMount = $this->userMountCache->getMountForPath($user, $path);
+		} catch (NotFoundException $e) {
+			$this->setupForUser($user);
+			return;
+		}
+
+		$mounts = [];
+		if (!in_array($cachedMount->getMountProvider(), $setupProviders)) {
+			$setupProviders[] = $cachedMount->getMountProvider();
+			$currentProviders[] = $cachedMount->getMountProvider();
+			if ($cachedMount->getMountProvider()) {
+				$mounts = $this->mountProviderCollection->getUserMountsForProviderClass($user, $cachedMount->getMountProvider());
+			} else {
+				$this->logger->debug("mount at " . $cachedMount->getMountPoint() . " has no provider set, performing full setup");
+				$this->setupForUser($user);
+				return;
+			}
+		}
+
+		if ($includeChildren) {
+			$subCachedMounts = $this->userMountCache->getMountsInPath($user, $path);
+			foreach ($subCachedMounts as $cachedMount) {
+				if (!in_array($cachedMount->getMountProvider(), $setupProviders)) {
+					$setupProviders[] = $cachedMount->getMountProvider();
+					$currentProviders[] = $cachedMount->getMountProvider();
+					if ($cachedMount->getMountProvider()) {
+						$mounts = array_merge($mounts, $this->mountProviderCollection->getUserMountsForProviderClass($user, $cachedMount->getMountProvider()));
+					} else {
+						$this->logger->debug("mount at " . $cachedMount->getMountPoint() . " has no provider set, performing full setup");
+						$this->setupForUser($user);
+						return;
+					}
+				}
+			}
+		}
+
+		if (count($mounts)) {
+			$this->userMountCache->registerMounts($user, $mounts, $currentProviders);
+			$this->setupForUserWith($user, function () use ($mounts) {
+				array_walk($mounts, [$this->mountManager, 'addMount']);
+			});
+		} elseif (!$this->isSetupStarted($user)) {
+			$this->oneTimeUserSetup($user);
+		}
 	}
 
 	public function tearDown() {
 		$this->setupUsers = [];
+		$this->setupUsersComplete = [];
+		$this->setupUserMountProviders = [];
 		$this->rootSetup = false;
 		$this->mountManager->clear();
 		$this->eventDispatcher->dispatchTyped(new FilesystemTornDownEvent());
@@ -280,7 +431,9 @@ class SetupManager {
 	private function listenForNewMountProviders() {
 		if (!$this->listeningForProviders) {
 			$this->listeningForProviders = true;
-			$this->mountProviderCollection->listen('\OC\Files\Config', 'registerMountProvider', function (IMountProvider $provider) {
+			$this->mountProviderCollection->listen('\OC\Files\Config', 'registerMountProvider', function (
+				IMountProvider $provider
+			) {
 				foreach ($this->setupUsers as $userId) {
 					$user = $this->userManager->get($userId);
 					if ($user) {
@@ -291,4 +444,40 @@ class SetupManager {
 			});
 		}
 	}
+
+	private function setupListeners() {
+		// note that this event handling is intentionally pessimistic
+		// clearing the cache to often is better than not enough
+
+		$this->eventDispatcher->addListener(UserAddedEvent::class, function (UserAddedEvent $event) {
+			$this->cache->remove($event->getUser()->getUID());
+		});
+		$this->eventDispatcher->addListener(UserRemovedEvent::class, function (UserRemovedEvent $event) {
+			$this->cache->remove($event->getUser()->getUID());
+		});
+		$this->eventDispatcher->addListener(ShareCreatedEvent::class, function (ShareCreatedEvent $event) {
+			$this->cache->remove($event->getShare()->getSharedWith());
+		});
+		$this->eventDispatcher->addListener(InvalidateMountCacheEvent::class, function (InvalidateMountCacheEvent $event
+		) {
+			if ($user = $event->getUser()) {
+				$this->cache->remove($user->getUID());
+			} else {
+				$this->cache->clear();
+			}
+		});
+
+		$genericEvents = [
+			'\OCA\Circles::onCircleCreation',
+			'\OCA\Circles::onCircleDestruction',
+			'\OCA\Circles::onMemberNew',
+			'\OCA\Circles::onMemberLeaving',
+		];
+
+		foreach ($genericEvents as $genericEvent) {
+			$this->eventDispatcher->addListener($genericEvent, function ($event) {
+				$this->cache->clear();
+			});
+		}
+	}
 }
diff --git a/lib/private/Files/SetupManagerFactory.php b/lib/private/Files/SetupManagerFactory.php
index 56e70d09961..1d9efbd411f 100644
--- a/lib/private/Files/SetupManagerFactory.php
+++ b/lib/private/Files/SetupManagerFactory.php
@@ -28,9 +28,12 @@ use OCP\EventDispatcher\IEventDispatcher;
 use OCP\Files\Config\IMountProviderCollection;
 use OCP\Files\Config\IUserMountCache;
 use OCP\Files\Mount\IMountManager;
+use OCP\ICacheFactory;
+use OCP\IConfig;
 use OCP\IUserManager;
 use OCP\IUserSession;
 use OCP\Lockdown\ILockdownManager;
+use Psr\Log\LoggerInterface;
 
 class SetupManagerFactory {
 	private IEventLogger $eventLogger;
@@ -41,6 +44,9 @@ class SetupManagerFactory {
 	private ILockdownManager $lockdownManager;
 	private IUserSession $userSession;
 	private ?SetupManager $setupManager;
+	private ICacheFactory $cacheFactory;
+	private LoggerInterface $logger;
+	private IConfig $config;
 
 	public function __construct(
 		IEventLogger $eventLogger,
@@ -49,7 +55,10 @@ class SetupManagerFactory {
 		IEventDispatcher $eventDispatcher,
 		IUserMountCache $userMountCache,
 		ILockdownManager $lockdownManager,
-		IUserSession $userSession
+		IUserSession $userSession,
+		ICacheFactory $cacheFactory,
+		LoggerInterface $logger,
+		IConfig $config
 	) {
 		$this->eventLogger = $eventLogger;
 		$this->mountProviderCollection = $mountProviderCollection;
@@ -58,6 +67,9 @@ class SetupManagerFactory {
 		$this->userMountCache = $userMountCache;
 		$this->lockdownManager = $lockdownManager;
 		$this->userSession = $userSession;
+		$this->cacheFactory = $cacheFactory;
+		$this->logger = $logger;
+		$this->config = $config;
 		$this->setupManager = null;
 	}
 
@@ -72,6 +84,9 @@ class SetupManagerFactory {
 				$this->userMountCache,
 				$this->lockdownManager,
 				$this->userSession,
+				$this->cacheFactory,
+				$this->logger,
+				$this->config
 			);
 		}
 		return $this->setupManager;
diff --git a/lib/public/Files/Config/IMountProviderCollection.php b/lib/public/Files/Config/IMountProviderCollection.php
index f845d72cee6..5894d06a388 100644
--- a/lib/public/Files/Config/IMountProviderCollection.php
+++ b/lib/public/Files/Config/IMountProviderCollection.php
@@ -39,6 +39,16 @@ interface IMountProviderCollection {
 	public function getMountsForUser(IUser $user);
 
 	/**
+	 * Get the configured mount points for the user from a specific mount provider
+	 *
+	 * @param \OCP\IUser $user
+	 * @param class-string<IMountProvider> $mountProviderClass
+	 * @return \OCP\Files\Mount\IMountPoint[]
+	 * @since 24.0.0
+	 */
+	public function getUserMountsForProviderClass(IUser $user, string $mountProviderClass);
+
+	/**
 	 * Get the configured home mount for this user
 	 *
 	 * @param \OCP\IUser $user
diff --git a/lib/public/Files/Config/IUserMountCache.php b/lib/public/Files/Config/IUserMountCache.php
index 08f95990d3c..4411200c7ae 100644
--- a/lib/public/Files/Config/IUserMountCache.php
+++ b/lib/public/Files/Config/IUserMountCache.php
@@ -25,6 +25,7 @@
 namespace OCP\Files\Config;
 
 use OCP\Files\Mount\IMountPoint;
+use OCP\Files\NotFoundException;
 use OCP\IUser;
 
 /**
@@ -38,9 +39,10 @@ interface IUserMountCache {
 	 *
 	 * @param IUser $user
 	 * @param IMountPoint[] $mounts
+	 * @param array|null $mountProviderClasses
 	 * @since 9.0.0
 	 */
-	public function registerMounts(IUser $user, array $mounts);
+	public function registerMounts(IUser $user, array $mounts, array $mountProviderClasses = null);
 
 	/**
 	 * Get all cached mounts for a user
@@ -125,4 +127,26 @@ interface IUserMountCache {
 	 * @since 20.0.0
 	 */
 	public function clear(): void;
+
+	/**
+	 * Get all cached mounts for a user
+	 *
+	 * @param IUser $user
+	 * @param string $path
+	 * @return ICachedMountInfo
+	 * @throws NotFoundException
+	 * @since 24.0.0
+	 */
+	public function getMountForPath(IUser $user, string $path): ICachedMountInfo;
+
+	/**
+	 * Get all cached mounts for a user inside a path
+	 *
+	 * @param IUser $user
+	 * @param string $path
+	 * @return ICachedMountInfo[]
+	 * @throws NotFoundException
+	 * @since 24.0.0
+	 */
+	public function getMountsInPath(IUser $user, string $path): array;
 }
diff --git a/lib/public/Files/Events/InvalidateMountCacheEvent.php b/lib/public/Files/Events/InvalidateMountCacheEvent.php
new file mode 100644
index 00000000000..6508e168d4c
--- /dev/null
+++ b/lib/public/Files/Events/InvalidateMountCacheEvent.php
@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2022 Robin Appelman <robin@icewind.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCP\Files\Events;
+
+use OCP\EventDispatcher\Event;
+use OCP\IUser;
+
+/**
+ * Used to notify the filesystem setup manager that the available mounts for a user have changed
+ *
+ * @since 24.0.0
+ */
+class InvalidateMountCacheEvent extends Event {
+	private ?IUser $user;
+
+	/**
+	 * @param IUser|null $user user
+	 *
+	 * @since 24.0.0
+	 */
+	public function __construct(?IUser $user) {
+		parent::__construct();
+		$this->user = $user;
+	}
+
+	/**
+	 * @return IUser|null user
+	 *
+	 * @since 24.0.0
+	 */
+	public function getUser(): ?IUser {
+		return $this->user;
+	}
+}