Linux: add emergency cleanup for stale unmounts

When normal filesystem unmount fails, the Linux path could stop before cleaning VeraCrypt mapper, loop and FUSE objects. Add an explicit emergency dismount request that is only reached after interactive confirmation.

The recovery path lazy-detaches mounted filesystems, uses deferred dmsetup removal for VeraCrypt mapper devices, detaches loop devices, and keeps normal force/ignoreOpenFiles behavior unchanged.

src/Main/CommandLineInterface.cpp

@@ -44,6 +44,9 @@ namespace VeraCrypt
 
 	CommandLineInterface::CommandLineInterface (int argc, wchar_t** argv, UserInterfaceType::Enum interfaceType) :
 		ArgCommand (CommandId::None),
+#ifdef TC_LINUX
+		ArgEmergencyUnmount (false),
+#endif
 		ArgFilesystem (VolumeCreationOptions::FilesystemType::Unknown),
 		ArgNewPim (-1),
 		ArgNoHiddenVolumeProtection (false),
@@ -79,6 +82,9 @@ namespace VeraCrypt
 		parser.AddSwitch (L"",	L"delete-token-keyfiles", _("Delete security token keyfiles"));
 		parser.AddSwitch (L"d", L"dismount",			_("Unmount volume (deprecated: use 'unmount')"));
 		parser.AddSwitch (L"u", L"unmount",				_("Unmount volume"));
+#ifdef TC_LINUX
+		parser.AddSwitch (L"",	L"emergency-unmount",	_("Attempt emergency cleanup if normal Linux unmount fails"));
+#endif
 		parser.AddSwitch (L"",	L"display-password",	_("Display password while typing"));
 		parser.AddOption (L"",	L"encryption",			_("Encryption algorithm"));
 		parser.AddSwitch (L"",	L"explore",				_("Open explorer window for mounted volume"));
@@ -405,6 +411,10 @@ namespace VeraCrypt
 
 		ArgForce = parser.Found (L"force");
 
+#ifdef TC_LINUX
+		ArgEmergencyUnmount = parser.Found (L"emergency-unmount");
+#endif
+
 		ArgDisableFileSizeCheck = parser.Found (L"no-size-check");
 		ArgUseLegacyPassword = parser.Found (L"legacy-password-maxlength");
 #if defined(TC_LINUX ) || defined (TC_FREEBSD)
@@ -730,6 +740,11 @@ namespace VeraCrypt
 		if (param1IsMountedVolumeSpec)
 			ArgVolumes = GetMountedVolumes (parser.GetParamCount() > 0 ? parser.GetParam (0) : wxString());
 
+#ifdef TC_LINUX
+		if (ArgEmergencyUnmount && ArgCommand != CommandId::DismountVolumes)
+			throw_err (L"--emergency-unmount is supported only with an unmount command");
+#endif
+
 		if (ArgCommand == CommandId::None && Application::GetUserInterfaceType() == UserInterfaceType::Text)
 			parser.Usage();
 	}

src/Main/CommandLineInterface.h

@@ -64,6 +64,9 @@ namespace VeraCrypt
 		CommandId::Enum ArgCommand;
 		bool ArgDisplayPassword;
 		shared_ptr <EncryptionAlgorithm> ArgEncryptionAlgorithm;
+#ifdef TC_LINUX
+		bool ArgEmergencyUnmount;
+#endif
 		shared_ptr <FilePath> ArgFilePath;
 		VolumeCreationOptions::FilesystemType::Enum ArgFilesystem;
 		bool ArgForce;

src/Main/Forms/WaitDialog.cpp

@@ -66,6 +66,7 @@ namespace VeraCrypt
 		VC_CONVERT_EXCEPTION (MissingArgument);
 		VC_CONVERT_EXCEPTION (NoItemSelected);
 		VC_CONVERT_EXCEPTION (StringFormatterException);
+		VC_CONVERT_EXCEPTION (FilesystemDismountFailed);
 		VC_CONVERT_EXCEPTION (ExecutedProcessFailed);
 		VC_CONVERT_EXCEPTION (AlreadyInitialized);
 		VC_CONVERT_EXCEPTION (AssertionFailed);

src/Main/UserInterface.cpp

@@ -157,8 +157,11 @@ namespace VeraCrypt
 		DismountVolumes (volumes, ignoreOpenFiles, interactive);
 	}
 
-	void UserInterface::DismountVolumes (VolumeInfoList volumes, bool ignoreOpenFiles, bool interactive) const
+	void UserInterface::DismountVolumes (VolumeInfoList volumes, bool ignoreOpenFiles, bool interactive, bool emergencyCleanupRequested) const
 	{
+#ifndef TC_LINUX
+		(void) emergencyCleanupRequested;
+#endif
 		BusyScope busy (this);
 
 		volumes.sort (VolumeInfo::FirstVolumeMountedAfterSecond);
@@ -180,6 +183,7 @@ namespace VeraCrypt
 			VolumeInfoList volumesLeft;
 			foreach (shared_ptr <VolumeInfo> volume, volumes)
 			{
+				bool emergencyCleanupPerformed = false;
 				try
 				{
 					BusyScope busy (this);
@@ -207,6 +211,42 @@ namespace VeraCrypt
 							throw UserAbort (SRC_POS);
 					}
 				}
+#ifdef TC_LINUX
+				catch (FilesystemDismountFailed&)
+				{
+					if (twoPassMode && firstPass)
+					{
+						volumesLeft.push_back (volume);
+						continue;
+					}
+
+					if (emergencyCleanupRequested)
+					{
+						{
+							BusyScope busy (this);
+							volume = Core->EmergencyDismountVolume (volume);
+						}
+						emergencyCleanupPerformed = true;
+						ShowWarning (StringFormatter (LangString["LINUX_EMERGENCY_UNMOUNTED"], wstring (volume->Path)));
+					}
+					else if (interactive)
+					{
+						if (AskYesNo (StringFormatter (LangString["LINUX_EMERGENCY_UNMOUNT_WARNING"], wstring (volume->Path)), false, true))
+						{
+							{
+								BusyScope busy (this);
+								volume = Core->EmergencyDismountVolume (volume);
+							}
+							emergencyCleanupPerformed = true;
+							ShowWarning (StringFormatter (LangString["LINUX_EMERGENCY_UNMOUNTED"], wstring (volume->Path)));
+						}
+						else
+							throw UserAbort (SRC_POS);
+					}
+					else
+						throw;
+				}
+#endif
 				catch (...)
 				{
 					if (twoPassMode && firstPass)
@@ -220,9 +260,12 @@ namespace VeraCrypt
 
 				if (Preferences.Verbose)
 				{
-					if (!message.IsEmpty())
-						message += L'\n';
-					message += StringFormatter (LangString["LINUX_VOL_UNMOUNTED"], wstring (volume->Path));
+					if (!emergencyCleanupPerformed)
+					{
+						if (!message.IsEmpty())
+							message += L'\n';
+						message += StringFormatter (LangString["LINUX_VOL_UNMOUNTED"], wstring (volume->Path));
+					}
 				}
 			}
 
@@ -1133,7 +1176,11 @@ const FileManager fileManagers[] = {
 			return true;
 
 		case CommandId::DismountVolumes:
-			DismountVolumes (cmdLine.ArgVolumes, cmdLine.ArgForce, !Preferences.NonInteractive);
+			DismountVolumes (cmdLine.ArgVolumes, cmdLine.ArgForce, !Preferences.NonInteractive
+#ifdef TC_LINUX
+				, cmdLine.ArgEmergencyUnmount
+#endif
+				);
 			return true;
 
 		case CommandId::DisplayVersion:
@@ -1277,6 +1324,15 @@ const FileManager fileManagers[] = {
 					" Force mounting of a volume in use, unmounting of a volume in use, or\n"
 					" overwriting a file. Note that this option has no effect on some platforms.\n"
 					"\n"
+#ifdef TC_LINUX
+					"--emergency-unmount\n"
+					" When used with --unmount on Linux, attempt emergency cleanup if normal\n"
+					" unmount fails. This recovery operation lazy-detaches the filesystem and\n"
+					" removes or schedules removal of VeraCrypt kernel objects. Pending writes may\n"
+					" already have failed, data may be lost, and cleanup may remain pending until\n"
+					" applications close open files. Use only for stale or removed-device states.\n"
+					"\n"
+#endif
 					"--fs-options=OPTIONS\n"
 					" Filesystem mount options. The OPTIONS argument is passed to mount(8)\n"
 					" command with option -o when a filesystem on a VeraCrypt volume is mounted.\n"
@@ -1719,6 +1775,7 @@ const FileManager fileManagers[] = {
 		VC_CONVERT_EXCEPTION (MissingArgument);
 		VC_CONVERT_EXCEPTION (NoItemSelected);
 		VC_CONVERT_EXCEPTION (StringFormatterException);
+		VC_CONVERT_EXCEPTION (FilesystemDismountFailed);
 		VC_CONVERT_EXCEPTION (ExecutedProcessFailed);
 		VC_CONVERT_EXCEPTION (AlreadyInitialized);
 		VC_CONVERT_EXCEPTION (AssertionFailed);

src/Main/UserInterface.h

@@ -41,7 +41,7 @@ namespace VeraCrypt
 		virtual void DeleteSecurityTokenKeyfiles () const = 0;
 		virtual void DismountAllVolumes (bool ignoreOpenFiles = false, bool interactive = true) const;
 		virtual void DismountVolume (shared_ptr <VolumeInfo> volume, bool ignoreOpenFiles = false, bool interactive = true) const;
-		virtual void DismountVolumes (VolumeInfoList volumes, bool ignoreOpenFiles = false, bool interactive = true) const;
+		virtual void DismountVolumes (VolumeInfoList volumes, bool ignoreOpenFiles = false, bool interactive = true, bool emergencyCleanup = false) const;
 		virtual void DisplayVolumeProperties (const VolumeInfoList &volumes) const;
 		virtual void DoShowError (const wxString &message) const = 0;
 		virtual void DoShowInfo (const wxString &message) const = 0;