Merge pull request #22802 from nextcloud/backport/stable18/22116-22648-22761

[stable18]  Fix share transfer of single files and on the transfered node

6 files changed, 391 insertions, 5 deletions

diff --git a/apps/files/lib/Service/OwnershipTransferService.php b/apps/files/lib/Service/OwnershipTransferService.php
index f47128a8d9f..8eb031df554 100644
--- a/apps/files/lib/Service/OwnershipTransferService.php
+++ b/apps/files/lib/Service/OwnershipTransferService.php
@@ -32,12 +32,14 @@ use OC\Files\Filesystem;
 use OC\Files\View;
 use OCA\Files\Exception\TransferOwnershipException;
 use OCP\Encryption\IManager as IEncryptionManager;
+use OCP\Files\Config\IUserMountCache;
 use OCP\Files\FileInfo;
 use OCP\Files\IHomeStorage;
 use OCP\Files\InvalidPathException;
 use OCP\Files\Mount\IMountManager;
 use OCP\IUser;
 use OCP\Share\IManager as IShareManager;
+use OCP\Share\IShare;
 use Symfony\Component\Console\Helper\ProgressBar;
 use Symfony\Component\Console\Output\NullOutput;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -59,12 +61,17 @@ class OwnershipTransferService {
 	/** @var IMountManager */
 	private $mountManager;
 
+	/** @var IUserMountCache */
+	private $userMountCache;
+
 	public function __construct(IEncryptionManager $manager,
 								IShareManager $shareManager,
-								IMountManager $mountManager) {
+								IMountManager $mountManager,
+								IUserMountCache $userMountCache) {
 		$this->encryptionManager = $manager;
 		$this->shareManager = $shareManager;
 		$this->mountManager = $mountManager;
+		$this->userMountCache = $userMountCache;
 	}
 
 	/**
@@ -145,7 +152,9 @@ class OwnershipTransferService {
 		// collect all the shares
 		$shares = $this->collectUsersShares(
 			$sourceUid,
-			$output
+			$output,
+			$view,
+			$sourcePath
 		);
 
 		// transfer the files
@@ -230,7 +239,9 @@ class OwnershipTransferService {
 	}
 
 	private function collectUsersShares(string $sourceUid,
-										OutputInterface $output): array {
+										OutputInterface $output,
+										View $view,
+										string $path): array {
 		$output->writeln("Collecting all share information for files and folders of $sourceUid ...");
 
 		$shares = [];
@@ -243,6 +254,23 @@ class OwnershipTransferService {
 				if (empty($sharePage)) {
 					break;
 				}
+				if ($path !== "$sourceUid/files") {
+					$sharePage = array_filter($sharePage, function (IShare $share) use ($view, $path) {
+						try {
+							$relativePath = $view->getPath($share->getNodeId());
+							$singleFileTranfer = $view->is_file($path);
+							if ($singleFileTranfer) {
+								return Filesystem::normalizePath($relativePath) === Filesystem::normalizePath($path);
+							}
+
+							return mb_strpos(
+								Filesystem::normalizePath($relativePath . '/', false),
+								Filesystem::normalizePath($path . '/', false)) === 0;
+						} catch (\Exception $e) {
+							return false;
+						}
+					});
+				}
 				$shares = array_merge($shares, $sharePage);
 				$offset += 50;
 			}
@@ -303,6 +331,12 @@ class OwnershipTransferService {
 						$share->setSharedBy($destinationUid);
 					}
 
+
+					// trigger refetching of the node so that the new owner and mountpoint are taken into account
+					// otherwise the checks on the share update will fail due to the original node not being available in the new user scope
+					$this->userMountCache->clear();
+					$share->setNodeId($share->getNode()->getId());
+
 					$this->shareManager->updateShare($share);
 				}
 			} catch (\OCP\Files\NotFoundException $e) {
diff --git a/build/integration/features/bootstrap/CommandLineContext.php b/build/integration/features/bootstrap/CommandLineContext.php
index 5bb87c04a94..83d767f53bc 100644
--- a/build/integration/features/bootstrap/CommandLineContext.php
+++ b/build/integration/features/bootstrap/CommandLineContext.php
@@ -25,6 +25,7 @@
 require __DIR__ . '/../../vendor/autoload.php';
 
 use Behat\Behat\Hook\Scope\BeforeScenarioScope;
+use PHPUnit\Framework\Assert;
 
 class CommandLineContext implements \Behat\Behat\Context\Context {
 	use CommandLine;
@@ -127,4 +128,11 @@ class CommandLineContext implements \Behat\Behat\Context\Context {
 		$davPath = rtrim($davPath, '/') . $this->lastTransferPath;
 		$this->featureContext->usingDavPath($davPath);
 	}
+
+	/**
+	 * @Then /^transfer folder name contains "([^"]+)"$/
+	 */
+	public function transferFolderNameContains($text) {
+		Assert::assertContains($text, $this->lastTransferPath);
+	}
 }
diff --git a/build/integration/features/bootstrap/Provisioning.php b/build/integration/features/bootstrap/Provisioning.php
index 4339c9a01af..c3fc21bbc8d 100644
--- a/build/integration/features/bootstrap/Provisioning.php
+++ b/build/integration/features/bootstrap/Provisioning.php
@@ -69,6 +69,23 @@ trait Provisioning {
 	}
 
 	/**
+	 * @Given /^user "([^"]*)" with displayname "((?:[^"]|\\")*)" exists$/
+	 * @param string $user
+	 */
+	public function assureUserWithDisplaynameExists($user, $displayname) {
+		try {
+			$this->userExists($user);
+		} catch (\GuzzleHttp\Exception\ClientException $ex) {
+			$previous_user = $this->currentUser;
+			$this->currentUser = "admin";
+			$this->creatingTheUser($user, $displayname);
+			$this->currentUser = $previous_user;
+		}
+		$this->userExists($user);
+		Assert::assertEquals(200, $this->response->getStatusCode());
+	}
+
+	/**
 	 * @Given /^user "([^"]*)" does not exist$/
 	 * @param string $user
 	 */
@@ -92,7 +109,7 @@ trait Provisioning {
 		}
 	}
 
-	public function creatingTheUser($user) {
+	public function creatingTheUser($user, $displayname = '') {
 		$fullUrl = $this->baseUrl . "v{$this->apiVersion}.php/cloud/users";
 		$client = new Client();
 		$options = [];
@@ -104,6 +121,9 @@ trait Provisioning {
 			'userid' => $user,
 			'password' => '123456'
 		];
+		if ($displayname !== '') {
+			$options['form_params']['displayName'] = $displayname;
+		}
 		$options['headers'] = [
 			'OCS-APIREQUEST' => 'true',
 		];
diff --git a/build/integration/features/transfer-ownership.feature b/build/integration/features/transfer-ownership.feature
index a0959db6c17..b091d00dae8 100644
--- a/build/integration/features/transfer-ownership.feature
+++ b/build/integration/features/transfer-ownership.feature
@@ -9,6 +9,10 @@ Feature: transfer-ownership
 		And As an "user1"
 		And using received transfer folder of "user1" as dav path
 		Then Downloaded content when downloading file "/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the file "/somefile.txt" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the file "/somefile.txt" exists
 
 	Scenario: transfering ownership of a folder
 		Given user "user0" exists
@@ -20,6 +24,26 @@ Feature: transfer-ownership
 		And As an "user1"
 		And using received transfer folder of "user1" as dav path
 		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+
+	Scenario: transfering ownership from user with risky display name
+		Given user "user0" with displayname "user0 \"risky\"? ヂspḷay 'na|\/|e':.#" exists
+		And user "user1" exists
+		And User "user0" created a folder "/test"
+		And User "user0" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		When transfering ownership from "user0" to "user1"
+		And the command was successful
+		And As an "user1"
+		And using received transfer folder of "user1" as dav path
+		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And transfer folder name contains "transferred from user0 -risky- ヂspḷay -na|-|e- on"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
 
 	Scenario: transfering ownership of file shares
 		Given user "user0" exists
@@ -32,6 +56,17 @@ Feature: transfer-ownership
 		And the command was successful
 		And As an "user2"
 		Then Downloaded content when downloading file "/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the file "/somefile.txt" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the file "/somefile.txt" exists
+		And As an "user1"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user1 |
+			| uid_file_owner | user1 |
+			| share_with | user2 |
 
 	Scenario: transfering ownership of folder shared with third user
 		Given user "user0" exists
@@ -45,6 +80,17 @@ Feature: transfer-ownership
 		And the command was successful
 		And As an "user2"
 		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+		And As an "user1"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user1 |
+			| uid_file_owner | user1 |
+			| share_with | user2 |
 
 	Scenario: transfering ownership of folder shared with transfer recipient
 		Given user "user0" exists
@@ -59,6 +105,12 @@ Feature: transfer-ownership
 		Then as "user1" the folder "/test" does not exist
 		And using received transfer folder of "user1" as dav path
 		And Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+		And Getting info of last share
+		And the OCS status code should be "404"
 
 	Scenario: transfering ownership of folder doubly shared with third user
 		Given group "group1" exists
@@ -76,6 +128,17 @@ Feature: transfer-ownership
 		And the command was successful
 		And As an "user2"
 		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+		And As an "user1"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user1 |
+			| uid_file_owner | user1 |
+			| share_with | user2 |
 
 	Scenario: transfering ownership of file shares to user with the same id as the group
 		Given user "user0" exists
@@ -90,6 +153,102 @@ Feature: transfer-ownership
 		And the command was successful
 		And As an "user2"
 		Then Downloaded content when downloading file "/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the file "/somefile.txt" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "test" the file "/somefile.txt" exists
+		And As an "test"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | test |
+			| uid_file_owner | test |
+			| share_with | test |
+
+	Scenario: transfering ownership of folder reshared with another user
+		Given user "user0" exists
+		And user "user1" exists
+		And user "user2" exists
+		And user "user3" exists
+		And User "user3" created a folder "/test"
+		And User "user3" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And folder "/test" of user "user3" is shared with user "user0" with permissions 31
+		And user "user0" accepts last share
+		And folder "/test" of user "user0" is shared with user "user2" with permissions 31
+		And user "user2" accepts last share
+		When transfering ownership from "user0" to "user1"
+		And the command was successful
+		And As an "user2"
+		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" exists
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" does not exist
+		And As an "user0"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user0 |
+			| uid_file_owner | user3 |
+			| share_with | user2 |
+
+	Scenario: transfering ownership of folder reshared with group to a user in the group
+		Given user "user0" exists
+		And user "user1" exists
+		And user "user2" exists
+		And user "user3" exists
+		And group "group1" exists
+		And user "user1" belongs to group "group1"
+		And User "user3" created a folder "/test"
+		And User "user3" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And folder "/test" of user "user3" is shared with user "user0" with permissions 31
+		And user "user0" accepts last share
+		And folder "/test" of user "user0" is shared with group "group1" with permissions 31
+		And user "user1" accepts last share
+		When transfering ownership from "user0" to "user1"
+		And the command was successful
+		And As an "user1"
+		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" exists
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" does not exist
+		And As an "user1"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user1 |
+			| uid_file_owner | user3 |
+			| share_with | group1 |
+
+	Scenario: transfering ownership of folder reshared with group to a user not in the group
+		Given user "user0" exists
+		And user "user1" exists
+		And user "user2" exists
+		And user "user3" exists
+		And group "group1" exists
+		And user "user2" belongs to group "group1"
+		And User "user3" created a folder "/test"
+		And User "user3" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And folder "/test" of user "user3" is shared with user "user0" with permissions 31
+		And user "user0" accepts last share
+		And folder "/test" of user "user0" is shared with group "group1" with permissions 31
+		And user "user2" accepts last share
+		When transfering ownership from "user0" to "user1"
+		And the command was successful
+		And As an "user2"
+		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" exists
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" does not exist
+		And As an "user0"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user0 |
+			| uid_file_owner | user3 |
+			| share_with | group1 |
 
 	Scenario: transfering ownership does not transfer received shares
 		Given user "user0" exists
@@ -103,6 +262,15 @@ Feature: transfer-ownership
 		And As an "user1"
 		And using received transfer folder of "user1" as dav path
 		Then as "user1" the folder "/test" does not exist
+		And using old dav path
+		And as "user0" the folder "/test" exists
+		And As an "user2"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user2 |
+			| uid_file_owner | user2 |
+			| share_with | user0 |
 
 	@local_storage
 	Scenario: transfering ownership does not transfer external storage
@@ -138,6 +306,20 @@ Feature: transfer-ownership
 		Then the command error output contains the text "Unknown target user"
 		And the command failed with exit code 1
 
+	Scenario: transfering ownership of a file
+		Given user "user0" exists
+		And user "user1" exists
+		And User "user0" uploads file "data/textfile.txt" to "/somefile.txt"
+		When transfering ownership of path "somefile.txt" from "user0" to "user1"
+		And the command was successful
+		And As an "user1"
+		And using received transfer folder of "user1" as dav path
+		Then Downloaded content when downloading file "/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the file "/somefile.txt" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the file "/somefile.txt" exists
+
 	Scenario: transfering ownership of a folder
 		Given user "user0" exists
 		And user "user1" exists
@@ -148,6 +330,77 @@ Feature: transfer-ownership
 		And As an "user1"
 		And using received transfer folder of "user1" as dav path
 		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+
+	Scenario: transfering ownership from user with risky display name
+		Given user "user0" with displayname "user0 \"risky\"? ヂspḷay 'na|\/|e':.#" exists
+		And user "user1" exists
+		And User "user0" created a folder "/test"
+		And User "user0" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		When transfering ownership of path "test" from "user0" to "user1"
+		And the command was successful
+		And As an "user1"
+		And using received transfer folder of "user1" as dav path
+		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And transfer folder name contains "transferred from user0 -risky- ヂspḷay -na|-|e- on"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+
+	Scenario: transfering ownership of path does not affect other files
+		Given user "user0" exists
+		And user "user1" exists
+		And User "user0" created a folder "/test"
+		And User "user0" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And User "user0" created a folder "/test2"
+		And User "user0" uploads file "data/textfile.txt" to "/test2/somefile.txt"
+		When transfering ownership of path "test" from "user0" to "user1"
+		And the command was successful
+		And As an "user1"
+		And using received transfer folder of "user1" as dav path
+		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And as "user0" the folder "/test2" exists
+		And as "user0" the file "/test2/somefile.txt" exists
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+		And as "user1" the folder "/test2" does not exist
+
+	Scenario: transfering ownership of path does not affect other shares
+		Given user "user0" exists
+		And user "user1" exists
+		And User "user0" created a folder "/test"
+		And User "user0" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And User "user0" created a folder "/test2"
+		And User "user0" uploads file "data/textfile.txt" to "/test2/sharedfile.txt"
+		And file "/test2/sharedfile.txt" of user "user0" is shared with user "user1" with permissions 19
+		And user "user1" accepts last share
+		When transfering ownership of path "test" from "user0" to "user1"
+		And the command was successful
+		And As an "user1"
+		And using received transfer folder of "user1" as dav path
+		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And as "user0" the folder "/test2" exists
+		And as "user0" the file "/test2/sharedfile.txt" exists
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+		And as "user1" the folder "/test2" does not exist
+		And using old dav path
+		And as "user1" the file "/sharedfile.txt" exists
+		And As an "user1"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user0 |
+			| uid_file_owner | user0 |
+			| share_with | user1 |
 
 	Scenario: transfering ownership of file shares
 		Given user "user0" exists
@@ -161,6 +414,17 @@ Feature: transfer-ownership
 		And the command was successful
 		And As an "user2"
 		Then Downloaded content when downloading file "/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+		And As an "user1"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user1 |
+			| uid_file_owner | user1 |
+			| share_with | user2 |
 
 	Scenario: transfering ownership of folder shared with third user
 		Given user "user0" exists
@@ -174,6 +438,17 @@ Feature: transfer-ownership
 		And the command was successful
 		And As an "user2"
 		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+		And As an "user1"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user1 |
+			| uid_file_owner | user1 |
+			| share_with | user2 |
 
 	Scenario: transfering ownership of folder shared with transfer recipient
 		Given user "user0" exists
@@ -188,6 +463,12 @@ Feature: transfer-ownership
 		Then as "user1" the folder "/test" does not exist
 		And using received transfer folder of "user1" as dav path
 		And Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+		And Getting info of last share
+		And the OCS status code should be "404"
 
 	Scenario: transfering ownership of folder doubly shared with third user
 		Given group "group1" exists
@@ -205,6 +486,32 @@ Feature: transfer-ownership
 		And the command was successful
 		And As an "user2"
 		Then Downloaded content when downloading file "/test/somefile.txt" with range "bytes=0-6" should be "This is"
+		And using old dav path
+		And as "user0" the folder "/test" does not exist
+		And using received transfer folder of "user1" as dav path
+		And as "user1" the folder "/test" exists
+		And As an "user1"
+		And Getting info of last share
+		And the OCS status code should be "100"
+		And Share fields of last share match with
+			| uid_owner | user1 |
+			| uid_file_owner | user1 |
+			| share_with | user2 |
+
+	Scenario: transfering ownership of path fails for reshares
+		Given user "user0" exists
+		And user "user1" exists
+		And user "user2" exists
+		And user "user3" exists
+		And User "user3" created a folder "/test"
+		And User "user3" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And folder "/test" of user "user3" is shared with user "user0" with permissions 31
+		And user "user0" accepts last share
+		And folder "/test" of user "user0" is shared with user "user2" with permissions 31
+		And user "user2" accepts last share
+		When transfering ownership of path "test" from "user0" to "user1"
+		Then the command failed with exit code 1
+		And the command error output contains the text "Could not transfer files."
 
 	Scenario: transfering ownership does not transfer received shares
 		Given user "user0" exists
@@ -219,7 +526,12 @@ Feature: transfer-ownership
 		And the command was successful
 		And As an "user1"
 		And using received transfer folder of "user1" as dav path
-		Then as "user1" the folder "/sub/test" does not exist
+		Then as "user1" the folder "/sub" exists
+		And as "user1" the folder "/sub/test" does not exist
+		And using old dav path
+		And as "user0" the folder "/sub" does not exist
+		And Getting info of last share
+		And the OCS status code should be "404"
 
 	Scenario: transfering ownership does not transfer external storage
 		Given user "user0" exists
diff --git a/lib/private/Files/Config/UserMountCache.php b/lib/private/Files/Config/UserMountCache.php
index 9cf3b43a431..32bfd5a71f3 100644
--- a/lib/private/Files/Config/UserMountCache.php
+++ b/lib/private/Files/Config/UserMountCache.php
@@ -409,4 +409,9 @@ class UserMountCache implements IUserMountCache {
 		$result->closeCursor();
 		return $results;
 	}
+
+	public function clear(): void {
+		$this->cacheInfoCache = new CappedMemoryCache();
+		$this->mountsForUsers = new CappedMemoryCache();
+	}
 }
diff --git a/lib/public/Files/Config/IUserMountCache.php b/lib/public/Files/Config/IUserMountCache.php
index 9fca98dc843..fde4898bd39 100644
--- a/lib/public/Files/Config/IUserMountCache.php
+++ b/lib/public/Files/Config/IUserMountCache.php
@@ -117,4 +117,11 @@ interface IUserMountCache {
 	 * @since 13.0.0
 	 */
 	public function getUsedSpaceForUsers(array $users);
+
+	/**
+	 * Clear all entries from the in-memory cache
+	 *
+	 * @since 20.0.0
+	 */
+	public function clear(): void;
 }