winvfs: initial work

Done by ckamm and dschmidt

CMakeLists.txt

@@ -3,6 +3,11 @@ set(CMAKE_CXX_STANDARD 14)
 
 project(client)
 
+if(UNIT_TESTING)
+    include(CTest)
+    enable_testing()
+endif()
+
 set(BIN_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
 
 
@@ -52,6 +57,9 @@ include(Warnings)
 include(${CMAKE_SOURCE_DIR}/VERSION.cmake)
 # For config.h
 include_directories(BEFORE ${CMAKE_CURRENT_BINARY_DIR})
+#include_directories(BEFORE
+#    "C:/Program Files (x86)/Windows Kits/10/Include/10.0.17134.0/um"
+#    "C:/Program Files (x86)/Windows Kits/10/Include/10.0.17134.0/shared")
 # Allows includes based on src/ like #include "common/utility.h" or #include "csync/csync.h"
 include_directories(
     ${CMAKE_CURRENT_SOURCE_DIR}/src
@@ -215,8 +223,9 @@ if( WIN32 )
 add_definitions( -D__USE_MINGW_ANSI_STDIO=1 )
 add_definitions( -DNOMINMAX )
 # Get APIs from from Vista onwards.
-add_definitions( -D_WIN32_WINNT=0x0601 )
-add_definitions( -DWINVER=0x0601 )
+add_definitions(-D_WIN32_WINNT=0x0601)
+add_definitions(-DWINVER=0x0601)
+add_definitions(-DNTDDI_VERSION=0x0A000004)
     if( MSVC )
     # Use automatic overload for suitable CRT safe-functions
     # See https://docs.microsoft.com/de-de/cpp/c-runtime-library/security-features-in-the-crt?view=vs-2019
@@ -254,8 +263,6 @@ if(BUILD_SHELL_INTEGRATION)
 endif()
 
 if(UNIT_TESTING)
-    include(CTest)
-    enable_testing()
     add_subdirectory(test)
 endif(UNIT_TESTING)
 

shell_integration/windows/NCContextMenu/NCContextMenuRegHandler.cpp

@@ -31,13 +31,23 @@ HRESULT SetHKCRRegistryKeyAndValue(PCWSTR pszSubKey, PCWSTR pszValueName, PCWSTR
 
     if (SUCCEEDED(hr))
     {
+        DWORD cbData;
+        const BYTE * lpData;
+
         if (pszData)
         {
             // Set the specified value of the key.
-            DWORD cbData = lstrlen(pszData) * sizeof(*pszData);
-            hr = HRESULT_FROM_WIN32(RegSetValueEx(hKey, pszValueName, 0,
-                REG_SZ, reinterpret_cast<const BYTE *>(pszData), cbData));
+            cbData = lstrlen(pszData) * sizeof(*pszData);
+            lpData = reinterpret_cast<const BYTE *>(pszData);
         }
+        else
+        {
+            cbData = 0;
+            lpData = NULL;
+        }
+
+        hr = HRESULT_FROM_WIN32(RegSetValueEx(hKey, pszValueName, 0,
+            REG_SZ, lpData, cbData));
 
         RegCloseKey(hKey);
     }
@@ -88,6 +98,11 @@ HRESULT NCContextMenuRegHandler::RegisterInprocServer(PCWSTR pszModule, const CL
     {
         hr = SetHKCRRegistryKeyAndValue(szSubkey, nullptr, pszFriendlyName);
 
+        // Create the HKCR\CLSID\{<CLSID>}\ContextMenuOptIn subkey.
+        if (SUCCEEDED(hr)) {
+            hr = SetHKCRRegistryKeyAndValue(szSubkey, L"ContextMenuOptIn", NULL);
+        }
+
         // Create the HKCR\CLSID\{<CLSID>}\InprocServer32 key.
         if (SUCCEEDED(hr))
         {

src/CMakeLists.txt

@@ -84,3 +84,4 @@ if(KRAZY2_EXECUTABLE)
                        ${PROJECT_SOURCE_DIR}/src/cmd/*.cpp
 )
 endif()
+

src/common/common.cmake

@@ -9,4 +9,5 @@ set(common_SOURCES
     ${CMAKE_CURRENT_LIST_DIR}/syncjournalfilerecord.cpp
     ${CMAKE_CURRENT_LIST_DIR}/utility.cpp
     ${CMAKE_CURRENT_LIST_DIR}/remotepermissions.cpp
+    ${CMAKE_CURRENT_LIST_DIR}/vfs.cpp
 )

src/common/utility.h

@@ -243,6 +243,12 @@ namespace Utility {
     OCSYNC_EXPORT bool registryDeleteKeyValue(HKEY hRootKey, const QString &subKey, const QString &valueName);
     OCSYNC_EXPORT bool registryWalkSubKeys(HKEY hRootKey, const QString &subKey, const std::function<void(HKEY, const QString &)> &callback);
     OCSYNC_EXPORT QRect getTaskbarDimensions();
+
+    // Possibly refactor to share code with UnixTimevalToFileTime in c_time.c
+    OCSYNC_EXPORT void UnixTimeToFiletime(time_t t, FILETIME *filetime);
+    OCSYNC_EXPORT void FiletimeToLargeIntegerFiletime(FILETIME *filetime, LARGE_INTEGER *hundredNSecs);
+    OCSYNC_EXPORT void UnixTimeToLargeIntegerFiletime(time_t t, LARGE_INTEGER *hundredNSecs);
+
 #endif
 }
 /** @} */ // \addtogroup

src/common/utility_win.cpp

@@ -314,4 +314,24 @@ DWORD Utility::convertSizeToDWORD(size_t &convertVar)
     return static_cast<DWORD>(convertVar);
 }
 
+void Utility::UnixTimeToFiletime(time_t t, FILETIME *filetime)
+{
+    LONGLONG ll = Int32x32To64(t, 10000000) + 116444736000000000;
+    filetime->dwLowDateTime = (DWORD) ll;
+    filetime->dwHighDateTime = ll >>32;
+}
+
+void Utility::FiletimeToLargeIntegerFiletime(FILETIME *filetime, LARGE_INTEGER *hundredNSecs)
+{
+    hundredNSecs->LowPart = filetime->dwLowDateTime;
+    hundredNSecs->HighPart = filetime->dwHighDateTime;
+}
+
+void Utility::UnixTimeToLargeIntegerFiletime(time_t t, LARGE_INTEGER *hundredNSecs)
+{
+    LONGLONG ll = Int32x32To64(t, 10000000) + 116444736000000000;
+    hundredNSecs->LowPart = (DWORD) ll;
+    hundredNSecs->HighPart = ll >>32;
+}
+
 } // namespace OCC

src/common/vfs.cpp

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) by Dominik Schmidt <dschmidt@owncloud.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "vfs.h"
+
+using namespace OCC;
+
+Vfs::Vfs(QObject* parent)
+    : QObject(parent)
+{
+}
+
+Vfs::~Vfs() = default;
+
+QString Vfs::modeToString(Mode mode)
+{
+    // Note: Strings are used for config and must be stable
+    switch (mode) {
+    case Off:
+        return QStringLiteral("off");
+    case WithSuffix:
+        return QStringLiteral("suffix");
+    case WindowsCfApi:
+        return QStringLiteral("wincfapi");
+    }
+    return QStringLiteral("off");
+}
+
+bool Vfs::modeFromString(const QString &str, Mode *mode)
+{
+    // Note: Strings are used for config and must be stable
+    *mode = Off;
+    if (str == "off") {
+        return true;
+    } else if (str == "suffix") {
+        *mode = WithSuffix;
+        return true;
+    } else if (str == "wincfapi") {
+        *mode = WindowsCfApi;
+        return true;
+    }
+    return false;
+}

src/common/vfs.h

@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) by Christian Kamm <mail@ckamm.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License
+ * for more details.
+ */
+#pragma once
+
+#include <QObject>
+#include <QScopedPointer>
+#include <QSharedPointer>
+
+#include "ocsynclib.h"
+
+typedef struct csync_file_stat_s csync_file_stat_t;
+
+namespace OCC {
+
+class Account;
+typedef QSharedPointer<Account> AccountPtr;
+class SyncJournalDb;
+class VfsPrivate;
+class SyncFileItem;
+typedef QSharedPointer<SyncFileItem> SyncFileItemPtr;
+
+struct OCSYNC_EXPORT VfsSetupParams
+{
+    QString filesystemPath;
+    QString remotePath;
+
+    AccountPtr account;
+    // The journal must live at least until the stop() call
+    SyncJournalDb *journal;
+
+    QString providerName;
+    QString providerVersion;
+};
+
+class OCSYNC_EXPORT Vfs : public QObject
+{
+    Q_OBJECT
+
+public:
+    enum Mode
+    {
+        Off,
+        WithSuffix,
+        WindowsCfApi,
+    };
+    static QString modeToString(Mode mode);
+    static bool modeFromString(const QString &str, Mode *mode);
+
+public:
+    Vfs(QObject* parent = nullptr);
+    virtual ~Vfs();
+
+    virtual Mode mode() const = 0;
+
+    // For WithSuffix modes: what's the suffix (including the dot)?
+    virtual QString fileSuffix() const = 0;
+
+    virtual void registerFolder(const VfsSetupParams &params) = 0;
+    virtual void start(const VfsSetupParams &params) = 0;
+    virtual void stop() = 0;
+    virtual void unregisterFolder() = 0;
+
+    virtual bool isHydrating() const = 0;
+
+    // Update placeholder metadata during discovery
+    virtual bool updateMetadata(const QString &filePath, time_t modtime, quint64 size, const QByteArray &fileId, QString *error) = 0;
+
+    // Create and convert placeholders in PropagateDownload
+    virtual void createPlaceholder(const QString &syncFolder, const SyncFileItemPtr &item) = 0;
+    virtual void convertToPlaceholder(const QString &filename, const SyncFileItemPtr &item) = 0;
+
+    // Determine whether something is a placeholder
+    virtual bool isDehydratedPlaceholder(const QString &filePath) = 0;
+
+    // Determine whether something is a placeholder in discovery
+    // stat has at least 'path' filled
+    // the stat_data argument has platform specific data
+    // returning true means that the file_stat->type was set and should be fixed
+    virtual bool statTypeVirtualFile(csync_file_stat_t *stat, void *stat_data) = 0;
+
+signals:
+    void beginHydrating();
+    void doneHydrating();
+};
+
+} // namespace OCC

src/csync/csync.h

@@ -137,7 +137,8 @@ enum ItemType {
     ItemTypeDirectory = 2,
     ItemTypeSkip = 3,
     ItemTypeVirtualFile = 4,
-    ItemTypeVirtualFileDownload = 5
+    ItemTypeVirtualFileDownload = 5,
+    ItemTypeVirtualFileDehydration = 6,
 };
 
 
@@ -146,7 +147,9 @@ enum ItemType {
 // currently specified at https://github.com/owncloud/core/issues/8322 are 9 to 10
 #define REMOTE_PERM_BUF_SIZE 15
 
-struct OCSYNC_EXPORT csync_file_stat_t {
+typedef struct csync_file_stat_s csync_file_stat_t;
+
+struct OCSYNC_EXPORT csync_file_stat_s {
   time_t modtime = 0;
   int64_t size = 0;
   uint64_t inode = 0;
@@ -177,7 +180,7 @@ struct OCSYNC_EXPORT csync_file_stat_t {
 
   enum csync_instructions_e instruction = CSYNC_INSTRUCTION_NONE; /* u32 */
 
-  csync_file_stat_t()
+  csync_file_stat_s()
     : type(ItemTypeSkip)
     , child_modified(false)
     , has_ignored_files(false)

src/csync/vio/csync_vio_local.h

@@ -25,7 +25,7 @@ struct csync_vio_handle_t;
 
 csync_vio_handle_t OCSYNC_EXPORT *csync_vio_local_opendir(const QString &name);
 int OCSYNC_EXPORT csync_vio_local_closedir(csync_vio_handle_t *dhandle);
-std::unique_ptr<csync_file_stat_t> OCSYNC_EXPORT csync_vio_local_readdir(csync_vio_handle_t *dhandle);
+std::unique_ptr<csync_file_stat_t> OCSYNC_EXPORT csync_vio_local_readdir(CSYNC *ctx, csync_vio_handle_t *dhandle);
 
 int OCSYNC_EXPORT csync_vio_local_stat(const char *uri, csync_file_stat_t *buf);
 

src/csync/vio/csync_vio_local_unix.cpp

@@ -35,6 +35,7 @@
 #include "csync_util.h"
 
 #include "vio/csync_vio_local.h"
+#include "common/vfsplugin.h"
 
 #include <QtCore/QLoggingCategory>
 #include <QtCore/QFile>
@@ -73,7 +74,7 @@ int csync_vio_local_closedir(csync_vio_handle_t *dhandle) {
     return rc;
 }
 
-std::unique_ptr<csync_file_stat_t> csync_vio_local_readdir(csync_vio_handle_t *handle) {
+std::unique_ptr<csync_file_stat_t> csync_vio_local_readdir(CSYNC *ctx, csync_vio_handle_t *handle) {
 
   struct _tdirent *dirent = NULL;
   std::unique_ptr<csync_file_stat_t> file_stat;
@@ -120,6 +121,11 @@ std::unique_ptr<csync_file_stat_t> csync_vio_local_readdir(csync_vio_handle_t *h
       // Will get excluded by _csync_detect_update.
       file_stat->type = ItemTypeSkip;
   }
+
+  // Override type for virtual files if desired
+  if (ctx->vfs)
+      ctx->vfs->statTypeVirtualFile(file_stat.get(), nullptr);
+
   return file_stat;
 }
 

src/csync/vio/csync_vio_local_win.cpp

@@ -38,6 +38,8 @@
 
 #include <QtCore/QLoggingCategory>
 
+#include "common/vfs.h"
+
 Q_LOGGING_CATEGORY(lcCSyncVIOLocal, "nextcloud.sync.csync.vio_local", QtInfoMsg)
 
 /*
@@ -113,7 +115,7 @@ static time_t FileTimeToUnixTime(FILETIME *filetime, DWORD *remainder)
     }
 }
 
-std::unique_ptr<csync_file_stat_t> csync_vio_local_readdir(csync_vio_handle_t *handle) {
+std::unique_ptr<csync_file_stat_t> csync_vio_local_readdir(CSYNC *ctx, csync_vio_handle_t *handle) {
 
   std::unique_ptr<csync_file_stat_t> file_stat;
   DWORD rem;
@@ -137,12 +139,14 @@ std::unique_ptr<csync_file_stat_t> csync_vio_local_readdir(csync_vio_handle_t *h
   }
   auto path = c_utf8_from_locale(handle->ffd.cFileName);
   if (path == "." || path == "..")
-      return csync_vio_local_readdir(handle);
+      return csync_vio_local_readdir(ctx, handle);
 
   file_stat = std::make_unique<csync_file_stat_t>();
   file_stat->path = path;
 
-  if (handle->ffd.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
+    if (ctx->vfs && ctx->vfs->statTypeVirtualFile(file_stat.get(), &handle->ffd)) {
+      // all good
+    } else if (handle->ffd.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
       // Detect symlinks, and treat junctions as symlinks too.
       if (handle->ffd.dwReserved0 == IO_REPARSE_TAG_SYMLINK
           || handle->ffd.dwReserved0 == IO_REPARSE_TAG_MOUNT_POINT) {

src/gui/accountsettings.cpp

@@ -535,7 +535,11 @@ void AccountSettings::slotFolderWizardAccepted()
         folderWizard->field(QLatin1String("sourceFolder")).toString());
     definition.targetPath = FolderDefinition::prepareTargetPath(
         folderWizard->property("targetPath").toString());
-    definition.useVirtualFiles = folderWizard->property("useVirtualFiles").toBool();
+
+    if (folderWizard->property("useVirtualFiles").toBool()) {
+        // ### Determine which vfs is available?
+        definition.virtualFilesMode = Vfs::WindowsCfApi;
+    }
 
     {
         QDir dir(definition.localPath);

src/gui/folder.cpp

@@ -32,7 +32,8 @@
 #include "filesystem.h"
 #include "localdiscoverytracker.h"
 #include "csync_exclude.h"
-
+#include "common/vfs.h"
+#include "plugin.h"
 #include "creds/abstractcredentials.h"
 
 #include <QTimer>
@@ -42,6 +43,7 @@
 
 #include <QMessageBox>
 #include <QPushButton>
+#include <QApplication>
 
 static const char versionC[] = "version";
 
@@ -115,10 +117,53 @@ Folder::Folder(const FolderDefinition &definition,
         _localDiscoveryTracker.data(), &LocalDiscoveryTracker::slotSyncFinished);
     connect(_engine.data(), &SyncEngine::itemCompleted,
         _localDiscoveryTracker.data(), &LocalDiscoveryTracker::slotItemCompleted);
+
+    // TODO cfapi: Move to function. Is this platform-universal?
+    PluginLoader pluginLoader;
+    if (_definition.virtualFilesMode == Vfs::WindowsCfApi) {
+        _vfs = pluginLoader.create<Vfs>("vfs", "win", this);
+    }
+    if (_definition.virtualFilesMode == Vfs::WithSuffix) {
+        _vfs = pluginLoader.create<Vfs>("vfs", "suffix", this);
+
+        // Attempt to switch to winvfs mode?
+        if (_vfs && _definition.upgradeVfsMode) {
+            if (auto winvfs = pluginLoader.create<Vfs>("vfs", "win", this)) {
+                // Set "suffix" vfs options and wipe the existing suffix files
+                SyncEngine::wipeVirtualFiles(path(), _journal, _vfs);
+
+                // Then switch to winvfs mode
+                _vfs = winvfs;
+                _definition.virtualFilesMode = Vfs::WindowsCfApi;
+                saveToSettings();
+            }
+        }
+    }
+    if (!_vfs) {
+        // ### error handling; possibly earlier than in the ctor
+        qFatal("Could not load any vfs plugin.");
+    }
+
+    VfsSetupParams vfsParams;
+    vfsParams.filesystemPath = path();
+    vfsParams.remotePath = remotePath();
+    vfsParams.account = _accountState->account();
+    vfsParams.journal = &_journal;
+    vfsParams.providerName = Theme::instance()->appNameGUI();
+    vfsParams.providerVersion = Theme::instance()->version();
+
+    connect(_vfs, &OCC::Vfs::beginHydrating, this, &Folder::slotHydrationStarts);
+    connect(_vfs, &OCC::Vfs::doneHydrating, this, &Folder::slotHydrationDone);
+
+    _vfs->registerFolder(vfsParams); // Do this always?
+    _vfs->start(vfsParams);
 }
 
 Folder::~Folder()
 {
+    // TODO cfapi: unregister on wipe()? There should probably be a wipeForRemoval() where this cleanup is appropriate
+    _vfs->stop();
+
     // Reset then engine first as it will abort and try to access members of the Folder
     _engine.reset();
 }
@@ -218,12 +263,12 @@ QString Folder::cleanPath() const
 
 bool Folder::isBusy() const
 {
-    return _engine->isSyncRunning();
+    return isSyncRunning();
 }
 
 bool Folder::isSyncRunning() const
 {
-    return _engine->isSyncRunning();
+    return _engine->isSyncRunning() || _vfs->isHydrating();
 }
 
 QString Folder::remotePath() const
@@ -551,7 +596,8 @@ void Folder::downloadVirtualFile(const QString &_relativepath)
 
 void Folder::setUseVirtualFiles(bool enabled)
 {
-    _definition.useVirtualFiles = enabled;
+    // ### must wipe virtual files, unload old plugin, load new one?
+    //_definition.useVirtualFiles = enabled;
     if (enabled)
         _saveInFoldersWithPlaceholders = true;
     saveToSettings();
@@ -571,7 +617,7 @@ void Folder::saveToSettings() const
         return other != this && other->cleanPath() == this->cleanPath();
     });
 
-    if (_definition.useVirtualFiles || _saveInFoldersWithPlaceholders) {
+    if (useVirtualFiles() || _saveInFoldersWithPlaceholders) {
         // If virtual files are enabled or even were enabled at some point,
         // save the folder to a group that will not be read by older (<2.5.0) clients.
         // The name is from when virtual files were called placeholders.
@@ -739,8 +785,7 @@ void Folder::setSyncOptions()
     opt._newBigFolderSizeLimit = newFolderLimit.first ? newFolderLimit.second * 1000LL * 1000LL : -1; // convert from MB to B
     opt._confirmExternalStorage = cfgFile.confirmExternalStorage();
     opt._moveFilesToTrash = cfgFile.moveToTrash();
-    opt._newFilesAreVirtual = _definition.useVirtualFiles;
-    opt._virtualFileSuffix = QStringLiteral(APPLICATION_DOTVIRTUALFILE_SUFFIX);
+    opt._vfs = _vfs;
 
     QByteArray chunkSizeEnv = qgetenv("OWNCLOUD_CHUNK_SIZE");
     if (!chunkSizeEnv.isEmpty()) {
@@ -1046,6 +1091,30 @@ void Folder::slotWatcherUnreliable(const QString &message)
     Logger::instance()->postGuiLog(Theme::instance()->appNameGUI(), fullMessage);
 }
 
+void Folder::slotHydrationStarts()
+{
+    // Abort any running full sync run and reschedule
+    if (_engine->isSyncRunning()) {
+        slotTerminateSync();
+        scheduleThisFolderSoon();
+        // TODO: This sets the sync state to AbortRequested on done, we don't want that
+    }
+
+    // Let everyone know we're syncing
+    _syncResult.reset();
+    _syncResult.setStatus(SyncResult::SyncRunning);
+    emit syncStarted();
+    emit syncStateChange();
+}
+
+void Folder::slotHydrationDone()
+{
+    // emit signal to update ui and reschedule normal syncs if necessary
+    _syncResult.setStatus(SyncResult::Success);
+    emit syncFinished(_syncResult);
+    emit syncStateChange();
+}
+
 void Folder::scheduleThisFolderSoon()
 {
     if (!_scheduleSelfTimer.isActive()) {
@@ -1076,6 +1145,11 @@ void Folder::registerFolderWatcher()
     _folderWatcher->startNotificatonTest(path() + QLatin1String(".owncloudsync.log"));
 }
 
+bool Folder::useVirtualFiles() const
+{
+    return _definition.virtualFilesMode != Vfs::Off;
+}
+
 void Folder::slotAboutToRemoveAllFiles(SyncFileItem::Direction dir, bool *cancel)
 {
     ConfigFile cfgFile;
@@ -1117,9 +1191,11 @@ void FolderDefinition::save(QSettings &settings, const FolderDefinition &folder)
     settings.setValue(QLatin1String("targetPath"), folder.targetPath);
     settings.setValue(QLatin1String("paused"), folder.paused);
     settings.setValue(QLatin1String("ignoreHiddenFiles"), folder.ignoreHiddenFiles);
-    settings.setValue(QLatin1String("usePlaceholders"), folder.useVirtualFiles);
     settings.setValue(QLatin1String(versionC), maxSettingsVersion());
 
+    settings.setValue(QStringLiteral("virtualFilesMode"), Vfs::modeToString(folder.virtualFilesMode));
+    settings.remove(QLatin1String("usePlaceholders")); // deprecated key
+
     // Happens only on Windows when the explorer integration is enabled.
     if (!folder.navigationPaneClsid.isNull())
         settings.setValue(QLatin1String("navigationPaneClsid"), folder.navigationPaneClsid);
@@ -1139,7 +1215,18 @@ bool FolderDefinition::load(QSettings &settings, const QString &alias,
     folder->paused = settings.value(QLatin1String("paused")).toBool();
     folder->ignoreHiddenFiles = settings.value(QLatin1String("ignoreHiddenFiles"), QVariant(true)).toBool();
     folder->navigationPaneClsid = settings.value(QLatin1String("navigationPaneClsid")).toUuid();
-    folder->useVirtualFiles = settings.value(QLatin1String("usePlaceholders")).toBool();
+
+    folder->virtualFilesMode = Vfs::Off;
+    QString vfsModeString = settings.value(QStringLiteral("virtualFilesMode")).toString();
+    if (!vfsModeString.isEmpty()) {
+        if (!Vfs::modeFromString(vfsModeString, &folder->virtualFilesMode)) {
+            qCWarning(lcFolder) << "Unknown virtualFilesMode:" << vfsModeString << "assuming 'off'";
+        }
+    } else if (settings.value(QLatin1String("usePlaceholders")).toBool()) {
+        folder->virtualFilesMode = Vfs::WithSuffix;
+        folder->upgradeVfsMode = true;
+    }
+
     settings.endGroup();
 
     // Old settings can contain paths with native separators. In the rest of the

src/gui/folder.h

@@ -21,6 +21,7 @@
 #include "progressdispatcher.h"
 #include "common/syncjournaldb.h"
 #include "networkjobs.h"
+#include "syncoptions.h"
 
 #include <QObject>
 #include <QStringList>
@@ -33,6 +34,7 @@ class QSettings;
 
 namespace OCC {
 
+class Vfs;
 class SyncEngine;
 class AccountState;
 class SyncRunFileLog;
@@ -58,11 +60,15 @@ public:
     bool paused = false;
     /// whether the folder syncs hidden files
     bool ignoreHiddenFiles = false;
-    /// New files are downloaded as virtual files
-    bool useVirtualFiles = false;
+    /// Which virtual files setting the folder uses
+    Vfs::Mode virtualFilesMode = Vfs::Off;
     /// The CLSID where this folder appears in registry for the Explorer navigation pane entry.
     QUuid navigationPaneClsid;
 
+    /// Whether this suffix-vfs should be migrated to a better
+    /// vfs plugin if possible
+    bool upgradeVfsMode = false;
+
     /// Saves the folder definition, creating a new settings group.
     static void save(QSettings &settings, const FolderDefinition &folder);
 
@@ -173,7 +179,7 @@ public:
     SyncResult syncResult() const;
 
     /**
-      * This is called if the sync folder definition is removed. Do cleanups here.
+      * This is called when the sync folder definition is removed. Do cleanups here.
       */
     virtual void wipe();
 
@@ -240,8 +246,8 @@ public:
      */
     void registerFolderWatcher();
 
-    /** new files are downloaded as virtual files */
-    bool useVirtualFiles() { return _definition.useVirtualFiles; }
+    /** virtual files of some kind are enabled */
+    bool useVirtualFiles() const;
     void setUseVirtualFiles(bool enabled);
 
 signals:
@@ -336,7 +342,19 @@ private slots:
     /** Warn users about an unreliable folder watcher */
     void slotWatcherUnreliable(const QString &message);
 
+    /** Aborts any running sync and blocks it until hydration is finished.
+     *
+     * Hydration circumvents the regular SyncEngine and both mustn't be running
+     * at the same time.
+     */
+    void slotHydrationStarts();
+
+    /** Unblocks normal sync operation */
+    void slotHydrationDone();
+
 private:
+    void connectSyncRoot();
+
     bool reloadExcludes();
 
     void showSyncResultPopup();
@@ -416,6 +434,11 @@ private:
      * Keeps track of locally dirty files so we can skip local discovery sometimes.
      */
     QScopedPointer<LocalDiscoveryTracker> _localDiscoveryTracker;
+
+    /**
+     * The vfs mode instance (created by plugin) to use. Null means no vfs.
+     */
+    Vfs *_vfs = nullptr;
 };
 }
 

src/gui/folderman.cpp

@@ -29,9 +29,6 @@
 #ifdef Q_OS_MAC
 #include <CoreServices/CoreServices.h>
 #endif
-#ifdef Q_OS_WIN
-#include <shlobj.h>
-#endif
 
 #include <QMessageBox>
 #include <QtCore>
@@ -1003,7 +1000,6 @@ Folder *FolderMan::addFolder(AccountState *accountState, const FolderDefinition
     }
 
     _navigationPaneHelper.scheduleUpdateCloudStorageRegistry();
-
     return folder;
 }
 

src/gui/owncloudsetupwizard.cpp

@@ -635,7 +635,10 @@ void OwncloudSetupWizard::slotAssistantFinished(int result)
             folderDefinition.localPath = localFolder;
             folderDefinition.targetPath = FolderDefinition::prepareTargetPath(_remoteFolder);
             folderDefinition.ignoreHiddenFiles = folderMan->ignoreHiddenFiles();
-            folderDefinition.useVirtualFiles = _ocWizard->useVirtualFileSync();
+            if (_ocWizard->useVirtualFileSync()) {
+                // ### determine best vfs mode!
+                folderDefinition.virtualFilesMode = Vfs::WindowsCfApi;
+            }
             if (folderMan->navigationPaneHelper().showInExplorerNavigationPane())
                 folderDefinition.navigationPaneClsid = QUuid::createUuid();
 

src/gui/socketapi.cpp

@@ -689,52 +689,51 @@ void SocketApi::command_OPEN_PRIVATE_LINK(const QString &localFile, SocketListen
 void SocketApi::command_DOWNLOAD_VIRTUAL_FILE(const QString &filesArg, SocketListener *)
 {
     QStringList files = filesArg.split(QLatin1Char('\x1e')); // Record Separator
-    auto suffix = QStringLiteral(APPLICATION_DOTVIRTUALFILE_SUFFIX);
 
     for (const auto &file : files) {
-        if (!file.endsWith(suffix) && !QFileInfo(file).isDir())
+        auto data = FileData::get(file);
+        auto record = data.journalRecord();
+        if (!record.isValid())
             continue;
-        auto folder = FolderMan::instance()->folderForPath(file);
-        if (folder) {
-            QString relativePath = QDir::cleanPath(file).mid(folder->cleanPath().length() + 1);
-            folder->downloadVirtualFile(relativePath);
-        }
+        if (record._type != ItemTypeVirtualFile && !QFileInfo(file).isDir())
+            continue;
+        if (data.folder)
+            data.folder->downloadVirtualFile(data.folderRelativePath);
     }
 }
 
-/* Go over all the files ans replace them by a virtual file */
+/* Go over all the files and replace them by a virtual file */
 void SocketApi::command_REPLACE_VIRTUAL_FILE(const QString &filesArg, SocketListener *)
 {
     QStringList files = filesArg.split(QLatin1Char('\x1e')); // Record Separator
-    auto suffix = QStringLiteral(APPLICATION_DOTVIRTUALFILE_SUFFIX);
 
+    QSet<Folder *> toSync;
     for (const auto &file : files) {
-        auto folder = FolderMan::instance()->folderForPath(file);
-        if (!folder)
+        auto data = FileData::get(file);
+        if (!data.folder)
             continue;
-        if (file.endsWith(suffix))
-            continue;
-        QString relativePath = QDir::cleanPath(file).mid(folder->cleanPath().length() + 1);
+        auto journal = data.folder->journalDb();
+        auto markForDehydration = [&](SyncJournalFileRecord rec) {
+            if (rec._type != ItemTypeFile)
+                return;
+            rec._type = ItemTypeVirtualFileDehydration;
+            journal->setFileRecord(rec);
+            toSync.insert(data.folder);
+        };
+
         QFileInfo fi(file);
         if (fi.isDir()) {
-            folder->journalDb()->getFilesBelowPath(relativePath.toUtf8(), [&](const SyncJournalFileRecord &rec) {
-                if (rec._type != ItemTypeFile || rec._path.endsWith(APPLICATION_DOTVIRTUALFILE_SUFFIX))
-                    return;
-                QString file = folder->path() + '/' + QString::fromUtf8(rec._path);
-                if (!FileSystem::rename(file, file + suffix)) {
-                    qCWarning(lcSocketApi) << "Unable to rename " << file;
-                }
-            });
+            journal->getFilesBelowPath(data.folderRelativePath.toUtf8(), markForDehydration);
             continue;
         }
-        SyncJournalFileRecord record;
-        if (!folder->journalDb()->getFileRecord(relativePath, &record) || !record.isValid())
+        auto record = data.journalRecord();
+        if (!record.isValid() || record._type != ItemTypeFile)
             continue;
-        if (!FileSystem::rename(file, file + suffix)) {
-            qCWarning(lcSocketApi) << "Unable to rename " << file;
-        }
-        FolderMan::instance()->scheduleFolder(folder);
+        markForDehydration(record);
     }
+
+    for (const auto folder : toSync)
+        FolderMan::instance()->scheduleFolder(folder);
 }
 
 void SocketApi::copyUrlToClipboard(const QString &link)
@@ -1012,18 +1011,18 @@ void SocketApi::command_GET_MENU_ITEMS(const QString &argument, OCC::SocketListe
 
     // Virtual file download action
     if (syncFolder) {
-        auto virtualFileSuffix = QStringLiteral(APPLICATION_DOTVIRTUALFILE_SUFFIX);
         bool hasVirtualFile = false;
         bool hasNormalFiles = false;
         bool hasDir = false;
         for (const auto &file : files) {
             if (QFileInfo(file).isDir()) {
                 hasDir = true;
-            } else if (file.endsWith(virtualFileSuffix)) {
-                hasVirtualFile = true;
-            } else if (!hasNormalFiles) {
-                bool isOnTheServer = FileData::get(file).journalRecord().isValid();
-                hasNormalFiles = isOnTheServer;
+            } else if (!hasVirtualFile || !hasNormalFiles) {
+                auto record = FileData::get(file).journalRecord();
+                if (record.isValid()) {
+                    hasVirtualFile |= record._type == ItemTypeVirtualFile;
+                    hasNormalFiles |= record._type == ItemTypeFile;
+                }
             }
         }
         if (hasVirtualFile || (hasDir && syncFolder->useVirtualFiles()))

src/libsync/CMakeLists.txt

@@ -33,6 +33,7 @@ set(libsync_SRCS
     networkjobs.cpp
     owncloudpropagator.cpp
     nextcloudtheme.cpp
+    plugin.cpp
     progressdispatcher.cpp
     propagatorjobs.cpp
     propagatedownload.cpp
@@ -140,3 +141,4 @@ else()
 endif()
 
 
+add_subdirectory(vfs)

src/libsync/discoveryphase.cpp

@@ -77,7 +77,7 @@ bool DiscoveryPhase::isInSelectiveSyncBlackList(const QString &path) const
 void DiscoveryPhase::checkSelectiveSyncNewFolder(const QString &path, RemotePermissions remotePerm,
     std::function<void(bool)> callback)
 {
-    if (_syncOptions._confirmExternalStorage && !_syncOptions._newFilesAreVirtual
+    if (_syncOptions._confirmExternalStorage && !_syncOptions._vfs
         && remotePerm.hasPermission(RemotePermissions::IsMounted)) {
         // external storage.
 
@@ -100,7 +100,7 @@ void DiscoveryPhase::checkSelectiveSyncNewFolder(const QString &path, RemotePerm
     }
 
     auto limit = _syncOptions._newBigFolderSizeLimit;
-    if (limit < 0 || _syncOptions._newFilesAreVirtual) {
+    if (limit < 0 || !_syncOptions._vfs) {
         // no limit, everything is allowed;
         return callback(false);
     }

src/libsync/filesystem.cpp

@@ -189,5 +189,15 @@ bool FileSystem::removeRecursively(const QString &path, const std::function<void
     return allRemoved;
 }
 
+bool FileSystem::getInode(const QString &filename, quint64 *inode)
+{
+    csync_file_stat_t fs;
+    if (csync_vio_local_stat(filename.toUtf8().constData(), &fs) == 0) {
+        *inode = fs.inode;
+        return true;
+    }
+    return false;
+}
+
 
 } // namespace OCC

src/libsync/filesystem.h

@@ -63,6 +63,11 @@ namespace FileSystem {
      */
     qint64 OWNCLOUDSYNC_EXPORT getSize(const QString &filename);
 
+    /**
+     * @brief Retrieve a file inode with csync
+     */
+    bool OWNCLOUDSYNC_EXPORT getInode(const QString &filename, quint64 *inode);
+
     /**
      * @brief Check if \a fileName has changed given previous size and mtime
      *

src/libsync/owncloudpropagator.cpp

@@ -584,11 +584,6 @@ QString OwncloudPropagator::getFilePath(const QString &tmp_file_name) const
     return _localDir + tmp_file_name;
 }
 
-QString OwncloudPropagator::addVirtualFileSuffix(const QString &fileName) const
-{
-    return fileName + _syncOptions._virtualFileSuffix;
-}
-
 void OwncloudPropagator::scheduleNextJob()
 {
     QTimer::singleShot(0, this, &OwncloudPropagator::scheduleNextJobImpl);

src/libsync/owncloudpropagator.h

@@ -449,7 +449,6 @@ public:
 
     /* returns the local file path for the given tmp_file_name */
     QString getFilePath(const QString &tmp_file_name) const;
-    QString addVirtualFileSuffix(const QString &fileName) const;
 
     /** Creates the job for an item.
      */

src/libsync/plugin.cpp

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) by Dominik Schmidt <dschmidt@owncloud.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "plugin.h"
+
+#include "config.h"
+#include "logger.h"
+
+#include <QPluginLoader>
+#include <QDir>
+
+Q_LOGGING_CATEGORY(lcPluginLoader, "pluginLoader", QtInfoMsg)
+
+namespace OCC {
+
+PluginFactory::~PluginFactory() = default;
+
+QObject *PluginLoader::createInternal(const QString& type, const QString &name, QObject* parent)
+{
+    auto factory = load<PluginFactory>(type, name);
+    if (!factory) {
+        return nullptr;
+    } else {
+        return factory->create(parent);
+    }
+}
+
+QString PluginLoader::pluginName(const QString &type, const QString &name)
+{
+    return QString(QLatin1String("%1sync_%2_%3"))
+            .arg(APPLICATION_EXECUTABLE)
+            .arg(type)
+            .arg(name);
+}
+
+QObject *PluginLoader::loadPluginInternal(const QString& type, const QString &name)
+{
+    QString fileName = pluginName(type, name);
+    QPluginLoader pluginLoader(fileName);
+    auto plugin = pluginLoader.load();
+    if(plugin) {
+        qCInfo(lcPluginLoader) << "Loaded plugin" << fileName;
+    } else {
+        qCWarning(lcPluginLoader) << "Could not load plugin"
+                                  << fileName <<":"
+                                  << pluginLoader.errorString()
+                                  << "from" << QDir::currentPath();
+    }
+
+    return pluginLoader.instance();
+}
+
+}

src/libsync/plugin.h

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) by Dominik Schmidt <dschmidt@owncloud.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#pragma once
+
+#include "owncloudlib.h"
+#include <QObject>
+#include <QPluginLoader>
+
+namespace OCC {
+
+class OWNCLOUDSYNC_EXPORT PluginFactory
+{
+public:
+    ~PluginFactory();
+    virtual QObject* create(QObject* parent) = 0;
+};
+
+template<class PLUGIN_CLASS>
+class DefaultPluginFactory : public PluginFactory
+{
+public:
+    QObject* create(QObject* parent) override
+    {
+        return new PLUGIN_CLASS(parent);
+    }
+};
+
+class OWNCLOUDSYNC_EXPORT PluginLoader
+{
+public:
+    static QString pluginName(const QString &type, const QString &name);
+
+    template<class PLUGIN_CLASS, typename ... Args>
+    PLUGIN_CLASS *create(Args&& ... args)
+    {
+        return qobject_cast<PLUGIN_CLASS*>(createInternal(std::forward<Args>(args)...));
+    }
+
+private:
+    template<class FACTORY_CLASS, typename ... Args>
+    FACTORY_CLASS *load(Args&& ... args)
+    {
+        return qobject_cast<FACTORY_CLASS*>(loadPluginInternal(std::forward<Args>(args)...));
+    }
+
+    QObject *loadPluginInternal(const QString& type, const QString &name);
+    QObject *createInternal(const QString& type, const QString &name, QObject* parent = nullptr);
+};
+
+}
+
+Q_DECLARE_INTERFACE(OCC::PluginFactory, "org.owncloud.PluginFactory")

src/libsync/propagatedownload.cpp

@@ -26,6 +26,7 @@
 #include "common/asserts.h"
 #include "clientsideencryptionjobs.h"
 #include "propagatedownloadencrypted.h"
+#include "common/vfs.h"
 
 #include <QLoggingCategory>
 #include <QNetworkAccessManager>
@@ -68,13 +69,15 @@ QString OWNCLOUDSYNC_EXPORT createDownloadTmpFileName(const QString &previous)
 }
 
 // DOES NOT take ownership of the device.
-GETFileJob::GETFileJob(AccountPtr account, const QString &path, QFile *device,
+GETFileJob::GETFileJob(AccountPtr account, const QString &path, QIODevice *device,
     const QMap<QByteArray, QByteArray> &headers, const QByteArray &expectedEtagForResume,
     quint64 resumeStart, QObject *parent)
     : AbstractNetworkJob(account, path, parent)
     , _device(device)
     , _headers(headers)
     , _expectedEtagForResume(expectedEtagForResume)
+    , _expectedContentLength(-1)
+    , _contentLength(0)
     , _resumeStart(resumeStart)
     , _errorStatus(SyncFileItem::NoStatus)
     , _bandwidthLimited(false)
@@ -86,7 +89,7 @@ GETFileJob::GETFileJob(AccountPtr account, const QString &path, QFile *device,
 {
 }
 
-GETFileJob::GETFileJob(AccountPtr account, const QUrl &url, QFile *device,
+GETFileJob::GETFileJob(AccountPtr account, const QUrl &url, QIODevice *device,
     const QMap<QByteArray, QByteArray> &headers, const QByteArray &expectedEtagForResume,
     quint64 resumeStart, QObject *parent)
 
@@ -94,6 +97,8 @@ GETFileJob::GETFileJob(AccountPtr account, const QUrl &url, QFile *device,
     , _device(device)
     , _headers(headers)
     , _expectedEtagForResume(expectedEtagForResume)
+    , _expectedContentLength(-1)
+    , _contentLength(0)
     , _resumeStart(resumeStart)
     , _errorStatus(SyncFileItem::NoStatus)
     , _directDownloadUrl(url)
@@ -201,6 +206,16 @@ void GETFileJob::slotMetaDataChanged()
         return;
     }
 
+    _contentLength = reply()->header(QNetworkRequest::ContentLengthHeader).toLongLong();
+    if (_expectedContentLength != -1 && _contentLength != _expectedContentLength) {
+        qCWarning(lcGetJob) << "We received a different content length than expected!"
+                            << _expectedContentLength << "vs" << _contentLength;
+        _errorString = tr("We received an unexpected download Content-Length.");
+        _errorStatus = SyncFileItem::NormalError;
+        reply()->abort();
+        return;
+    }
+
     quint64 start = 0;
     QByteArray ranges = reply()->rawHeader("Content-Range");
     if (!ranges.isEmpty()) {
@@ -399,17 +414,30 @@ void PropagateDownloadFile::startAfterIsEncryptedIsChecked()
 {
     _stopwatch.start();
 
+    auto &syncOptions = propagator()->syncOptions();
+    auto vfs = syncOptions._vfs;
+
     // For virtual files just create the file and be done
+    if (_item->_type == ItemTypeVirtualFileDehydration) {
+        _item->_type = ItemTypeVirtualFile;
+        // TODO: Could dehydrate without wiping the file entirely
+        auto fn = propagator()->getFilePath(_item->_file);
+        qCDebug(lcPropagateDownload) << "dehydration: wiping base file" << fn;
+        QFile::remove(fn);
+        propagator()->_journal->deleteFileRecord(_item->_file);
+
+        if (vfs && vfs->mode() == Vfs::WithSuffix) {
+            // Normally new suffix-virtual files already have the suffix included in the path
+            // but for dehydrations that isn't the case. Adjust it here.
+            _item->_file.append(vfs->fileSuffix());
+        }
+    }
     if (_item->_type == ItemTypeVirtualFile) {
         auto fn = propagator()->getFilePath(_item->_file);
         qCDebug(lcPropagateDownload) << "creating virtual file" << fn;
 
-        // NOTE: Other places might depend on contents of placeholder files (like csync_update)
-        QFile file(fn);
-        file.open(QFile::ReadWrite | QFile::Truncate);
-        file.write(" ");
-        file.close();
-        FileSystem::setModTime(fn, _item->_modtime);
+        ASSERT(vfs);
+        vfs->createPlaceholder(propagator()->_localDir, _item);
         updateMetadata(false);
         return;
     }
@@ -623,7 +651,7 @@ void PropagateDownloadFile::slotGetFinished()
 
         // Don't keep the temporary file if it is empty or we
         // used a bad range header or the file's not on the server anymore.
-        if (_tmpFile.size() == 0 || badRangeHeader || fileNotFound) {
+        if (_tmpFile.exists() && (_tmpFile.size() == 0 || badRangeHeader || fileNotFound)) {
             _tmpFile.close();
             FileSystem::remove(_tmpFile.fileName());
             propagator()->_journal->setDownloadInfo(_item->_file, SyncJournalDb::DownloadInfo());
@@ -957,6 +985,12 @@ void PropagateDownloadFile::downloadFinished()
         done(SyncFileItem::SoftError, error);
         return;
     }
+
+    // Make the file a hydrated placeholder if possible
+    if (auto vfs = propagator()->syncOptions()._vfs) {
+        vfs->convertToPlaceholder(fn, _item);
+    }
+
     FileSystem::setFileHidden(fn, false);
 
     // Maybe we downloaded a newer version of the file than we thought we would...
@@ -968,15 +1002,20 @@ void PropagateDownloadFile::downloadFinished()
     if (_conflictRecord.isValid())
         propagator()->_journal->setConflictRecord(_conflictRecord);
 
-    // If we downloaded something that used to be a virtual file,
-    // wipe the virtual file and its db entry now that we're done.
     if (_item->_type == ItemTypeVirtualFileDownload) {
-        auto virtualFile = propagator()->addVirtualFileSuffix(_item->_file);
-        auto fn = propagator()->getFilePath(virtualFile);
-        qCDebug(lcPropagateDownload) << "Download of previous virtual file finished" << fn;
-        QFile::remove(fn);
-        propagator()->_journal->deleteFileRecord(virtualFile);
+        // A downloaded virtual file becomes normal
         _item->_type = ItemTypeFile;
+
+        // If the virtual file used to have a different name and db
+        // entry, wipe both now.
+        auto vfs = propagator()->syncOptions()._vfs;
+        if (vfs && vfs->mode() == Vfs::WithSuffix) {
+            QString virtualFile = _item->_file + vfs->fileSuffix();
+            auto fn = propagator()->getFilePath(virtualFile);
+            qCDebug(lcPropagateDownload) << "Download of previous virtual file finished" << fn;
+            QFile::remove(fn);
+            propagator()->_journal->deleteFileRecord(virtualFile);
+        }
     }
 
     updateMetadata(isConflict);

src/libsync/propagatedownload.h

@@ -30,10 +30,12 @@ class PropagateDownloadEncrypted;
 class GETFileJob : public AbstractNetworkJob
 {
     Q_OBJECT
-    QFile *_device;
+    QIODevice *_device;
     QMap<QByteArray, QByteArray> _headers;
     QString _errorString;
     QByteArray _expectedEtagForResume;
+    qint64 _expectedContentLength;
+    quint64 _contentLength;
     quint64 _resumeStart;
     SyncFileItem::Status _errorStatus;
     QUrl _directDownloadUrl;
@@ -50,11 +52,11 @@ class GETFileJob : public AbstractNetworkJob
 
 public:
     // DOES NOT take ownership of the device.
-    explicit GETFileJob(AccountPtr account, const QString &path, QFile *device,
+    explicit GETFileJob(AccountPtr account, const QString &path, QIODevice *device,
         const QMap<QByteArray, QByteArray> &headers, const QByteArray &expectedEtagForResume,
         quint64 resumeStart, QObject *parent = nullptr);
     // For directDownloadUrl:
-    explicit GETFileJob(AccountPtr account, const QUrl &url, QFile *device,
+    explicit GETFileJob(AccountPtr account, const QUrl &url, QIODevice *device,
         const QMap<QByteArray, QByteArray> &headers, const QByteArray &expectedEtagForResume,
         quint64 resumeStart, QObject *parent = nullptr);
     virtual ~GETFileJob()
@@ -101,6 +103,9 @@ public:
     quint64 resumeStart() { return _resumeStart; }
     time_t lastModified() { return _lastModified; }
 
+    quint64 contentLength() const { return _contentLength; }
+    qint64 expectedContentLength() const { return _expectedContentLength; }
+    void setExpectedContentLength(qint64 size) { _expectedContentLength = size; }
 
 signals:
     void finishedSignal();

src/libsync/propagateremotemove.cpp

@@ -90,8 +90,10 @@ void PropagateRemoteMove::start()
 
     QString source = propagator()->_remoteFolder + _item->_file;
     QString destination = QDir::cleanPath(propagator()->account()->davUrl().path() + propagator()->_remoteFolder + _item->_renameTarget);
-    if (_item->_type == ItemTypeVirtualFile || _item->_type == ItemTypeVirtualFileDownload) {
-        auto suffix = propagator()->syncOptions()._virtualFileSuffix;
+    auto vfs = propagator()->syncOptions()._vfs;
+    if (vfs && vfs->mode() == Vfs::WithSuffix
+        && (_item->_type == ItemTypeVirtualFile || _item->_type == ItemTypeVirtualFileDownload)) {
+        const auto suffix = vfs->fileSuffix();
         ASSERT(source.endsWith(suffix) && destination.endsWith(suffix));
         if (source.endsWith(suffix) && destination.endsWith(suffix)) {
             source.chop(suffix.size());
@@ -162,6 +164,7 @@ void PropagateRemoteMove::finalize()
     record._path = _item->_renameTarget.toUtf8();
     if (oldRecord.isValid()) {
         record._checksumHeader = oldRecord._checksumHeader;
+        record._type = oldRecord._type;
         if (record._fileSize != oldRecord._fileSize) {
             qCWarning(lcPropagateRemoteMove) << "File sizes differ on server vs sync journal: " << record._fileSize << oldRecord._fileSize;
 

src/libsync/syncengine.cpp

@@ -28,6 +28,7 @@
 #include "common/asserts.h"
 #include "configfile.h"
 #include "discovery.h"
+#include "common/vfs.h"
 
 #ifdef Q_OS_WIN
 #include <windows.h>
@@ -332,6 +333,8 @@ void OCC::SyncEngine::slotItemDiscovered(const OCC::SyncFileItemPtr &item)
             rec._serverHasIgnoredFiles |= prev._serverHasIgnoredFiles;
             _journal->setFileRecord(rec);
 
+            // ### Update vfs metadata with Vfs::updateMetadata()
+
             // This might have changed the shared flag, so we must notify SyncFileStatusTracker for example
             emit itemCompleted(item);
         } else {
@@ -469,10 +472,12 @@ void SyncEngine::startSync()
 
     _lastLocalDiscoveryStyle = _localDiscoveryStyle;
 
-    if (_syncOptions._newFilesAreVirtual && _syncOptions._virtualFileSuffix.isEmpty()) {
-        syncError(tr("Using virtual files but suffix is not set"));
-        finalize(false);
-        return;
+    if (_syncOptions._vfs && _syncOptions._vfs->mode() == Vfs::WithSuffix) {
+        if (_syncOptions._vfs->fileSuffix().isEmpty()) {
+            syncError(tr("Using virtual files with suffix, but suffix is not set"));
+            finalize(false);
+            return;
+        }
     }
 
     // If needed, make sure we have up to date E2E information before the
@@ -985,6 +990,30 @@ bool SyncEngine::shouldDiscoverLocally(const QString &path) const
     return false;
 }
 
+void SyncEngine::wipeVirtualFiles(const QString &localPath, SyncJournalDb &journal, Vfs *vfs)
+{
+    qCInfo(lcEngine) << "Wiping virtual files inside" << localPath;
+    journal.getFilesBelowPath(QByteArray(), [&](const SyncJournalFileRecord &rec) {
+        if (rec._type != ItemTypeVirtualFile && rec._type != ItemTypeVirtualFileDownload)
+            return;
+
+        qCDebug(lcEngine) << "Removing db record for" << rec._path;
+        journal.deleteFileRecord(rec._path);
+
+        // If the local file is a dehydrated placeholder, wipe it too.
+        // Otherwise leave it to allow the next sync to have a new-new conflict.
+        QString localFile = localPath + rec._path;
+        if (QFile::exists(localFile) && vfs && vfs->isDehydratedPlaceholder(localFile)) {
+            qCDebug(lcEngine) << "Removing local dehydrated placeholder" << rec._path;
+            QFile::remove(localFile);
+        }
+    });
+
+    journal.forceRemoteDiscoveryNextSync();
+
+    // Postcondition: No ItemTypeVirtualFile / ItemTypeVirtualFileDownload left in the db
+}
+
 void SyncEngine::abort()
 {
     if (_propagator)

src/libsync/syncengine.h

@@ -119,6 +119,13 @@ public:
     /** Access the last sync run's local discovery style */
     LocalDiscoveryStyle lastLocalDiscoveryStyle() const { return _lastLocalDiscoveryStyle; }
 
+    /** Removes all virtual file db entries and dehydrated local placeholders.
+     *
+     * Particularly useful when switching off vfs mode or switching to a
+     * different kind of vfs.
+     */
+    static void wipeVirtualFiles(const QString &localPath, SyncJournalDb &journal, Vfs *vfs);
+
     auto getPropagator() { return _propagator; } // for the test
 
 signals:

src/libsync/syncfileitem.cpp

@@ -15,6 +15,7 @@
 #include "syncfileitem.h"
 #include "common/syncjournalfilerecord.h"
 #include "common/utility.h"
+#include "filesystem.h"
 
 #include <QLoggingCategory>
 #include "csync/vio/csync_vio_local.h"
@@ -37,17 +38,15 @@ SyncJournalFileRecord SyncFileItem::toSyncJournalFileRecordWithInode(const QStri
     rec._checksumHeader = _checksumHeader;
     rec._e2eMangledName = _encryptedFileName.toUtf8();
 
-    // Go through csync vio just to get the inode.
-    csync_file_stat_t fs;
-    if (csync_vio_local_stat(localFileName.toUtf8().constData(), &fs) == 0) {
-        rec._inode = fs.inode;
-        qCDebug(lcFileItem) << localFileName << "Retrieved inode " << _inode << "(previous item inode: " << _inode << ")";
+    // Update the inode if possible
+    rec._inode = _inode;
+    if (FileSystem::getInode(localFileName, &rec._inode)) {
+        qCDebug(lcFileItem) << localFileName << "Retrieved inode " << rec._inode << "(previous item inode: " << _inode << ")";
     } else {
         // use the "old" inode coming with the item for the case where the
         // filesystem stat fails. That can happen if the the file was removed
         // or renamed meanwhile. For the rename case we still need the inode to
         // detect the rename though.
-        rec._inode = _inode;
         qCWarning(lcFileItem) << "Failed to query the 'inode' for file " << localFileName;
     }
     return rec;

src/libsync/syncoptions.h

@@ -17,7 +17,7 @@
 #include "owncloudlib.h"
 #include <QString>
 #include <chrono>
-
+#include "common/vfs.h"
 
 namespace OCC {
 
@@ -37,8 +37,7 @@ struct SyncOptions
     bool _moveFilesToTrash = false;
 
     /** Create a virtual file for new files instead of downloading */
-    bool _newFilesAreVirtual = false;
-    QString _virtualFileSuffix = ".owncloud";
+    Vfs *_vfs = nullptr;
 
     /** The initial un-adjusted chunk size in bytes for chunked uploads, both
      * for old and new chunking algorithm, which classifies the item to be chunked

src/libsync/vfs/CMakeLists.txt

@@ -0,0 +1,12 @@
+### TODO: Find plugins dynamically
+list(APPEND vfsPlugins "suffix")
+
+foreach(vfsPlugin ${vfsPlugins})
+    message(STATUS "Add vfsPlugin in dir: ${vfsPlugin}")
+    add_subdirectory("${vfsPlugin}")
+
+    if(UNIT_TESTING AND IS_DIRECTORY "${CMAKE_CURRENT_LIST_DIR}/${vfsPlugin}/test")
+        message(STATUS "Add vfsPlugin tests in dir: ${vfsPlugin}")
+        add_subdirectory("${vfsPlugin}/test" "${vfsPlugin}_test")
+    endif()
+endforeach()

src/libsync/vfs/suffix/CMakeLists.txt

@@ -0,0 +1,15 @@
+add_library("${synclib_NAME}_vfs_suffix" SHARED
+    vfs_suffix.cpp
+)
+
+target_link_libraries("${synclib_NAME}_vfs_suffix"
+    "${synclib_NAME}"
+)
+
+set_target_properties("${synclib_NAME}_vfs_suffix" PROPERTIES
+    LIBRARY_OUTPUT_DIRECTORY ${BIN_OUTPUT_DIRECTORY}
+    RUNTIME_OUTPUT_DIRECTORY ${BIN_OUTPUT_DIRECTORY}
+    PREFIX ""
+    AUTOMOC TRUE
+)
+

src/libsync/vfs/suffix/vfs_suffix.cpp

@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) by Christian Kamm <mail@ckamm.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License
+ * for more details.
+ */
+
+#include "vfs_suffix.h"
+
+#include <QFile>
+
+#include "syncfileitem.h"
+#include "filesystem.h"
+
+namespace OCC {
+
+class VfsSuffixPrivate
+{
+};
+
+VfsSuffix::VfsSuffix(QObject *parent)
+    : Vfs(parent)
+    , d_ptr(new VfsSuffixPrivate)
+{
+}
+
+VfsSuffix::~VfsSuffix()
+{
+}
+
+Vfs::Mode VfsSuffix::mode() const
+{
+    return WithSuffix;
+}
+
+QString VfsSuffix::fileSuffix() const
+{
+    return QStringLiteral(APPLICATION_DOTVIRTUALFILE_SUFFIX);
+}
+
+void VfsSuffix::registerFolder(const VfsSetupParams &)
+{
+}
+
+void VfsSuffix::start(const VfsSetupParams &)
+{
+}
+
+void VfsSuffix::stop()
+{
+}
+
+void VfsSuffix::unregisterFolder()
+{
+}
+
+bool VfsSuffix::isHydrating() const
+{
+    return false;
+}
+
+bool VfsSuffix::updateMetadata(const QString &filePath, time_t modtime, quint64, const QByteArray &, QString *)
+{
+    FileSystem::setModTime(filePath, modtime);
+    return true;
+}
+
+void VfsSuffix::createPlaceholder(const QString &syncFolder, const SyncFileItemPtr &item)
+{
+    // NOTE: Other places might depend on contents of placeholder files (like csync_update)
+    QString fn = syncFolder + item->_file;
+    QFile file(fn);
+    file.open(QFile::ReadWrite | QFile::Truncate);
+    file.write(" ");
+    file.close();
+    FileSystem::setModTime(fn, item->_modtime);
+}
+
+void VfsSuffix::convertToPlaceholder(const QString &, const SyncFileItemPtr &)
+{
+    // Nothing necessary
+}
+
+bool VfsSuffix::isDehydratedPlaceholder(const QString &filePath)
+{
+    if (!filePath.endsWith(fileSuffix()))
+        return false;
+    QFileInfo fi(filePath);
+    return fi.exists() && fi.size() == 1;
+}
+
+bool VfsSuffix::statTypeVirtualFile(csync_file_stat_t *stat, void *)
+{
+    if (stat->path.endsWith(fileSuffix().toUtf8())) {
+        stat->type = ItemTypeVirtualFile;
+        return true;
+    }
+    return false;
+}
+
+} // namespace OCC

src/libsync/vfs/suffix/vfs_suffix.h

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) by Christian Kamm <mail@ckamm.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License
+ * for more details.
+ */
+#pragma once
+
+#include <QObject>
+#include <QScopedPointer>
+
+#include "common/vfs.h"
+#include "plugin.h"
+
+namespace OCC {
+
+class VfsSuffixPrivate;
+
+class VfsSuffix : public Vfs
+{
+    Q_OBJECT
+    Q_DECLARE_PRIVATE(VfsSuffix)
+    const QScopedPointer<VfsSuffixPrivate> d_ptr;
+
+public:
+    explicit VfsSuffix(QObject *parent = nullptr);
+    ~VfsSuffix();
+
+    Mode mode() const override;
+    QString fileSuffix() const override;
+
+    void registerFolder(const VfsSetupParams &params) override;
+    void start(const VfsSetupParams &params) override;
+    void stop() override;
+    void unregisterFolder() override;
+
+    bool isHydrating() const override;
+
+    bool updateMetadata(const QString &filePath, time_t modtime, quint64 size, const QByteArray &fileId, QString *error) override;
+
+    void createPlaceholder(const QString &syncFolder, const SyncFileItemPtr &item) override;
+    void convertToPlaceholder(const QString &filename, const SyncFileItemPtr &item) override;
+
+    bool isDehydratedPlaceholder(const QString &filePath) override;
+    bool statTypeVirtualFile(csync_file_stat_t *stat, void *stat_data) override;
+};
+
+class SuffixVfsPluginFactory : public QObject, public DefaultPluginFactory<VfsSuffix>
+{
+    Q_OBJECT
+    Q_PLUGIN_METADATA(IID "org.owncloud.PluginFactory")
+    Q_INTERFACES(OCC::PluginFactory)
+};
+
+} // namespace OCC

test/nextcloud_add_test.cmake

@@ -21,7 +21,12 @@ macro(nextcloud_add_test test_class additional_cpp)
 
     add_definitions(-DOWNCLOUD_TEST)
     add_definitions(-DOWNCLOUD_BIN_PATH="${CMAKE_BINARY_DIR}/bin")
-    add_test(NAME ${OWNCLOUD_TEST_CLASS}Test COMMAND ${OWNCLOUD_TEST_CLASS}Test)
+    message(STATUS "Add test: ${OWNCLOUD_TEST_CLASS}Test")
+    add_test(NAME ${OWNCLOUD_TEST_CLASS}Test
+        COMMAND ${OWNCLOUD_TEST_CLASS}Test
+        WORKING_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
+
+    target_include_directories(${OWNCLOUD_TEST_CLASS}Test PRIVATE "${CMAKE_SOURCE_DIR}/test/")
 endmacro()
 
 macro(nextcloud_add_benchmark test_class additional_cpp)

test/syncenginetestutils.h

@@ -931,6 +931,7 @@ public:
         syncOnce();
     }
 
+    OCC::AccountPtr account() const { return _account; }
     OCC::SyncEngine &syncEngine() const { return *_syncEngine; }
     OCC::SyncJournalDb &syncJournal() const { return *_journalDb; }
 

test/testsyncvirtualfiles.cpp

@@ -7,6 +7,8 @@
 
 #include <QtTest>
 #include "syncenginetestutils.h"
+#include "common/vfs.h"
+#include "plugin.h"
 #include <syncengine.h>
 
 using namespace OCC;
@@ -38,7 +40,7 @@ void triggerDownload(FakeFolder &folder, const QByteArray &path)
 {
     auto &journal = folder.syncJournal();
     SyncJournalFileRecord record;
-    journal.getFileRecord(path + ".owncloud", &record);
+    journal.getFileRecord(path + ".nextcloud", &record);
     if (!record.isValid())
         return;
     record._type = ItemTypeVirtualFileDownload;
@@ -46,6 +48,25 @@ void triggerDownload(FakeFolder &folder, const QByteArray &path)
     journal.avoidReadFromDbOnNextSync(record._path);
 }
 
+void markForDehydration(FakeFolder &folder, const QByteArray &path)
+{
+    auto &journal = folder.syncJournal();
+    SyncJournalFileRecord record;
+    journal.getFileRecord(path, &record);
+    if (!record.isValid())
+        return;
+    record._type = ItemTypeVirtualFileDehydration;
+    journal.setFileRecord(record);
+    journal.avoidReadFromDbOnNextSync(record._path);
+}
+
+SyncOptions vfsSyncOptions()
+{
+    SyncOptions options;
+    options._vfs = PluginLoader().create<Vfs>("vfs", "suffix");
+    return options;
+}
+
 class TestSyncVirtualFiles : public QObject
 {
     Q_OBJECT
@@ -64,9 +85,7 @@ private slots:
         QFETCH(bool, doLocalDiscovery);
 
         FakeFolder fakeFolder{ FileInfo() };
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
-        fakeFolder.syncEngine().setSyncOptions(syncOptions);
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
         QSignalSpy completeSpy(&fakeFolder.syncEngine(), SIGNAL(itemCompleted(const SyncFileItemPtr &)));
 
@@ -84,20 +103,20 @@ private slots:
         fakeFolder.remoteModifier().setModTime("A/a1", someDate);
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QCOMPARE(QFileInfo(fakeFolder.localPath() + "A/a1.owncloud").lastModified(), someDate);
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QCOMPARE(QFileInfo(fakeFolder.localPath() + "A/a1.nextcloud").lastModified(), someDate);
         QVERIFY(fakeFolder.currentRemoteState().find("A/a1"));
-        QVERIFY(itemInstruction(completeSpy, "A/a1.owncloud", CSYNC_INSTRUCTION_NEW));
-        QCOMPARE(dbRecord(fakeFolder, "A/a1.owncloud")._type, ItemTypeVirtualFile);
+        QVERIFY(itemInstruction(completeSpy, "A/a1.nextcloud", CSYNC_INSTRUCTION_NEW));
+        QCOMPARE(dbRecord(fakeFolder, "A/a1.nextcloud")._type, ItemTypeVirtualFile);
         cleanup();
 
         // Another sync doesn't actually lead to changes
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QCOMPARE(QFileInfo(fakeFolder.localPath() + "A/a1.owncloud").lastModified(), someDate);
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QCOMPARE(QFileInfo(fakeFolder.localPath() + "A/a1.nextcloud").lastModified(), someDate);
         QVERIFY(fakeFolder.currentRemoteState().find("A/a1"));
-        QCOMPARE(dbRecord(fakeFolder, "A/a1.owncloud")._type, ItemTypeVirtualFile);
+        QCOMPARE(dbRecord(fakeFolder, "A/a1.nextcloud")._type, ItemTypeVirtualFile);
         QVERIFY(completeSpy.isEmpty());
         cleanup();
 
@@ -105,10 +124,10 @@ private slots:
         fakeFolder.syncJournal().forceRemoteDiscoveryNextSync();
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QCOMPARE(QFileInfo(fakeFolder.localPath() + "A/a1.owncloud").lastModified(), someDate);
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QCOMPARE(QFileInfo(fakeFolder.localPath() + "A/a1.nextcloud").lastModified(), someDate);
         QVERIFY(fakeFolder.currentRemoteState().find("A/a1"));
-        QCOMPARE(dbRecord(fakeFolder, "A/a1.owncloud")._type, ItemTypeVirtualFile);
+        QCOMPARE(dbRecord(fakeFolder, "A/a1.nextcloud")._type, ItemTypeVirtualFile);
         QVERIFY(completeSpy.isEmpty());
         cleanup();
 
@@ -116,24 +135,24 @@ private slots:
         fakeFolder.remoteModifier().appendByte("A/a1");
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
         QVERIFY(fakeFolder.currentRemoteState().find("A/a1"));
-        QVERIFY(itemInstruction(completeSpy, "A/a1.owncloud", CSYNC_INSTRUCTION_UPDATE_METADATA));
-        QCOMPARE(dbRecord(fakeFolder, "A/a1.owncloud")._type, ItemTypeVirtualFile);
-        QCOMPARE(dbRecord(fakeFolder, "A/a1.owncloud")._fileSize, 65);
+        QVERIFY(itemInstruction(completeSpy, "A/a1.nextcloud", CSYNC_INSTRUCTION_UPDATE_METADATA));
+        QCOMPARE(dbRecord(fakeFolder, "A/a1.nextcloud")._type, ItemTypeVirtualFile);
+        QCOMPARE(dbRecord(fakeFolder, "A/a1.nextcloud")._fileSize, 65);
         cleanup();
 
         // If the local virtual file file is removed, it'll just be recreated
         if (!doLocalDiscovery)
             fakeFolder.syncEngine().setLocalDiscoveryOptions(LocalDiscoveryStyle::DatabaseAndFilesystem, { "A" });
-        fakeFolder.localModifier().remove("A/a1.owncloud");
+        fakeFolder.localModifier().remove("A/a1.nextcloud");
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
         QVERIFY(fakeFolder.currentRemoteState().find("A/a1"));
-        QVERIFY(itemInstruction(completeSpy, "A/a1.owncloud", CSYNC_INSTRUCTION_NEW));
-        QCOMPARE(dbRecord(fakeFolder, "A/a1.owncloud")._type, ItemTypeVirtualFile);
-        QCOMPARE(dbRecord(fakeFolder, "A/a1.owncloud")._fileSize, 65);
+        QVERIFY(itemInstruction(completeSpy, "A/a1.nextcloud", CSYNC_INSTRUCTION_NEW));
+        QCOMPARE(dbRecord(fakeFolder, "A/a1.nextcloud")._type, ItemTypeVirtualFile);
+        QCOMPARE(dbRecord(fakeFolder, "A/a1.nextcloud")._fileSize, 65);
         cleanup();
 
         // Remote rename is propagated
@@ -141,55 +160,53 @@ private slots:
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1m"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1m.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1m.nextcloud"));
         QVERIFY(!fakeFolder.currentRemoteState().find("A/a1"));
         QVERIFY(fakeFolder.currentRemoteState().find("A/a1m"));
         QVERIFY(
-            itemInstruction(completeSpy, "A/a1m.owncloud", CSYNC_INSTRUCTION_RENAME)
-            || (itemInstruction(completeSpy, "A/a1m.owncloud", CSYNC_INSTRUCTION_NEW)
-                && itemInstruction(completeSpy, "A/a1.owncloud", CSYNC_INSTRUCTION_REMOVE)));
-        QCOMPARE(dbRecord(fakeFolder, "A/a1m.owncloud")._type, ItemTypeVirtualFile);
+            itemInstruction(completeSpy, "A/a1m.nextcloud", CSYNC_INSTRUCTION_RENAME)
+            || (itemInstruction(completeSpy, "A/a1m.nextcloud", CSYNC_INSTRUCTION_NEW)
+                && itemInstruction(completeSpy, "A/a1.nextcloud", CSYNC_INSTRUCTION_REMOVE)));
+        QCOMPARE(dbRecord(fakeFolder, "A/a1m.nextcloud")._type, ItemTypeVirtualFile);
         cleanup();
 
         // Remote remove is propagated
         fakeFolder.remoteModifier().remove("A/a1m");
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a1m.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a1m.nextcloud"));
         QVERIFY(!fakeFolder.currentRemoteState().find("A/a1m"));
-        QVERIFY(itemInstruction(completeSpy, "A/a1m.owncloud", CSYNC_INSTRUCTION_REMOVE));
-        QVERIFY(!dbRecord(fakeFolder, "A/a1.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "A/a1m.owncloud").isValid());
+        QVERIFY(itemInstruction(completeSpy, "A/a1m.nextcloud", CSYNC_INSTRUCTION_REMOVE));
+        QVERIFY(!dbRecord(fakeFolder, "A/a1.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a1m.nextcloud").isValid());
         cleanup();
 
         // Edge case: Local virtual file but no db entry for some reason
         fakeFolder.remoteModifier().insert("A/a2", 64);
         fakeFolder.remoteModifier().insert("A/a3", 64);
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/a2.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a3.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a2.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a3.nextcloud"));
         cleanup();
 
-        fakeFolder.syncEngine().journal()->deleteFileRecord("A/a2.owncloud");
-        fakeFolder.syncEngine().journal()->deleteFileRecord("A/a3.owncloud");
+        fakeFolder.syncEngine().journal()->deleteFileRecord("A/a2.nextcloud");
+        fakeFolder.syncEngine().journal()->deleteFileRecord("A/a3.nextcloud");
         fakeFolder.remoteModifier().remove("A/a3");
         fakeFolder.syncEngine().setLocalDiscoveryOptions(LocalDiscoveryStyle::FilesystemOnly);
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/a2.owncloud"));
-        QVERIFY(itemInstruction(completeSpy, "A/a2.owncloud", CSYNC_INSTRUCTION_UPDATE_METADATA));
-        QVERIFY(dbRecord(fakeFolder, "A/a2.owncloud").isValid());
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a3.owncloud"));
-        QVERIFY(itemInstruction(completeSpy, "A/a3.owncloud", CSYNC_INSTRUCTION_REMOVE));
-        QVERIFY(!dbRecord(fakeFolder, "A/a3.owncloud").isValid());
+        QVERIFY(fakeFolder.currentLocalState().find("A/a2.nextcloud"));
+        QVERIFY(itemInstruction(completeSpy, "A/a2.nextcloud", CSYNC_INSTRUCTION_UPDATE_METADATA));
+        QVERIFY(dbRecord(fakeFolder, "A/a2.nextcloud").isValid());
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a3.nextcloud"));
+        QVERIFY(itemInstruction(completeSpy, "A/a3.nextcloud", CSYNC_INSTRUCTION_REMOVE));
+        QVERIFY(!dbRecord(fakeFolder, "A/a3.nextcloud").isValid());
         cleanup();
     }
 
     void testVirtualFileConflict()
     {
         FakeFolder fakeFolder{ FileInfo() };
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
-        fakeFolder.syncEngine().setSyncOptions(syncOptions);
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
         QSignalSpy completeSpy(&fakeFolder.syncEngine(), SIGNAL(itemCompleted(const SyncFileItemPtr &)));
 
@@ -208,8 +225,8 @@ private slots:
         fakeFolder.remoteModifier().mkdir("C");
         fakeFolder.remoteModifier().insert("C/c1", 64);
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("B/b2.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("B/b2.nextcloud"));
         cleanup();
 
         // A: the correct file and a conflicting file are added, virtual files stay
@@ -219,8 +236,8 @@ private slots:
         fakeFolder.localModifier().insert("A/a2", 30);
         fakeFolder.localModifier().insert("B/b1", 64);
         fakeFolder.localModifier().insert("B/b2", 30);
-        fakeFolder.localModifier().remove("B/b1.owncloud");
-        fakeFolder.localModifier().remove("B/b2.owncloud");
+        fakeFolder.localModifier().remove("B/b1.nextcloud");
+        fakeFolder.localModifier().remove("B/b2.nextcloud");
         fakeFolder.localModifier().mkdir("C/c1");
         fakeFolder.localModifier().insert("C/c1/foo");
         QVERIFY(fakeFolder.syncOnce());
@@ -233,11 +250,11 @@ private slots:
         QVERIFY(itemInstruction(completeSpy, "C/c1", CSYNC_INSTRUCTION_CONFLICT));
 
         // no virtual file files should remain
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a2.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("B/b1.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("B/b2.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("C/c1.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a2.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("B/b1.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("B/b2.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("C/c1.nextcloud"));
 
         // conflict files should exist
         QCOMPARE(fakeFolder.syncJournal().conflictRecordPaths().size(), 3);
@@ -248,11 +265,11 @@ private slots:
         QCOMPARE(dbRecord(fakeFolder, "B/b1")._type, ItemTypeFile);
         QCOMPARE(dbRecord(fakeFolder, "B/b2")._type, ItemTypeFile);
         QCOMPARE(dbRecord(fakeFolder, "C/c1")._type, ItemTypeFile);
-        QVERIFY(!dbRecord(fakeFolder, "A/a1.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "A/a2.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "B/b1.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "B/b2.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "C/c1.owncloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a1.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a2.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "B/b1.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "B/b2.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "C/c1.nextcloud").isValid());
 
         cleanup();
     }
@@ -260,9 +277,7 @@ private slots:
     void testWithNormalSync()
     {
         FakeFolder fakeFolder{ FileInfo::A12_B12_C12_S12() };
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
-        fakeFolder.syncEngine().setSyncOptions(syncOptions);
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
         QSignalSpy completeSpy(&fakeFolder.syncEngine(), SIGNAL(itemCompleted(const SyncFileItemPtr &)));
 
@@ -288,19 +303,17 @@ private slots:
         fakeFolder.remoteModifier().insert("A/new");
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(!fakeFolder.currentLocalState().find("A/new"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/new.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/new.nextcloud"));
         QVERIFY(fakeFolder.currentRemoteState().find("A/new"));
-        QVERIFY(itemInstruction(completeSpy, "A/new.owncloud", CSYNC_INSTRUCTION_NEW));
-        QCOMPARE(dbRecord(fakeFolder, "A/new.owncloud")._type, ItemTypeVirtualFile);
+        QVERIFY(itemInstruction(completeSpy, "A/new.nextcloud", CSYNC_INSTRUCTION_NEW));
+        QCOMPARE(dbRecord(fakeFolder, "A/new.nextcloud")._type, ItemTypeVirtualFile);
         cleanup();
     }
 
     void testVirtualFileDownload()
     {
         FakeFolder fakeFolder{ FileInfo() };
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
-        fakeFolder.syncEngine().setSyncOptions(syncOptions);
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
         QSignalSpy completeSpy(&fakeFolder.syncEngine(), SIGNAL(itemCompleted(const SyncFileItemPtr &)));
 
@@ -318,12 +331,12 @@ private slots:
         fakeFolder.remoteModifier().insert("A/a5");
         fakeFolder.remoteModifier().insert("A/a6");
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a2.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a3.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a4.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a5.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a6.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a2.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a3.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a4.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a5.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a6.nextcloud"));
         cleanup();
 
         // Download by changing the db entry
@@ -338,17 +351,17 @@ private slots:
         fakeFolder.remoteModifier().rename("A/a4", "A/a4m");
         fakeFolder.localModifier().insert("A/a5");
         fakeFolder.localModifier().insert("A/a6");
-        fakeFolder.localModifier().remove("A/a6.owncloud");
+        fakeFolder.localModifier().remove("A/a6.nextcloud");
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(itemInstruction(completeSpy, "A/a1", CSYNC_INSTRUCTION_NEW));
-        QVERIFY(itemInstruction(completeSpy, "A/a1.owncloud", CSYNC_INSTRUCTION_NONE));
+        QVERIFY(itemInstruction(completeSpy, "A/a1.nextcloud", CSYNC_INSTRUCTION_NONE));
         QVERIFY(itemInstruction(completeSpy, "A/a2", CSYNC_INSTRUCTION_NEW));
-        QVERIFY(itemInstruction(completeSpy, "A/a2.owncloud", CSYNC_INSTRUCTION_NONE));
-        QVERIFY(itemInstruction(completeSpy, "A/a3.owncloud", CSYNC_INSTRUCTION_REMOVE));
+        QVERIFY(itemInstruction(completeSpy, "A/a2.nextcloud", CSYNC_INSTRUCTION_NONE));
+        QVERIFY(itemInstruction(completeSpy, "A/a3.nextcloud", CSYNC_INSTRUCTION_REMOVE));
         QVERIFY(itemInstruction(completeSpy, "A/a4m", CSYNC_INSTRUCTION_NEW));
-        QVERIFY(itemInstruction(completeSpy, "A/a4.owncloud", CSYNC_INSTRUCTION_REMOVE));
+        QVERIFY(itemInstruction(completeSpy, "A/a4.nextcloud", CSYNC_INSTRUCTION_REMOVE));
         QVERIFY(itemInstruction(completeSpy, "A/a5", CSYNC_INSTRUCTION_CONFLICT));
-        QVERIFY(itemInstruction(completeSpy, "A/a5.owncloud", CSYNC_INSTRUCTION_NONE));
+        QVERIFY(itemInstruction(completeSpy, "A/a5.nextcloud", CSYNC_INSTRUCTION_NONE));
         QVERIFY(itemInstruction(completeSpy, "A/a6", CSYNC_INSTRUCTION_CONFLICT));
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
         QCOMPARE(dbRecord(fakeFolder, "A/a1")._type, ItemTypeFile);
@@ -357,20 +370,18 @@ private slots:
         QCOMPARE(dbRecord(fakeFolder, "A/a4m")._type, ItemTypeFile);
         QCOMPARE(dbRecord(fakeFolder, "A/a5")._type, ItemTypeFile);
         QCOMPARE(dbRecord(fakeFolder, "A/a6")._type, ItemTypeFile);
-        QVERIFY(!dbRecord(fakeFolder, "A/a1.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "A/a2.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "A/a3.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "A/a4.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "A/a5.owncloud").isValid());
-        QVERIFY(!dbRecord(fakeFolder, "A/a6.owncloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a1.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a2.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a3.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a4.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a5.nextcloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a6.nextcloud").isValid());
     }
 
     void testVirtualFileDownloadResume()
     {
         FakeFolder fakeFolder{ FileInfo() };
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
-        fakeFolder.syncEngine().setSyncOptions(syncOptions);
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
         QSignalSpy completeSpy(&fakeFolder.syncEngine(), SIGNAL(itemCompleted(const SyncFileItemPtr &)));
 
@@ -384,7 +395,7 @@ private slots:
         fakeFolder.remoteModifier().mkdir("A");
         fakeFolder.remoteModifier().insert("A/a1");
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
         cleanup();
 
         // Download by changing the db entry
@@ -392,29 +403,28 @@ private slots:
         fakeFolder.serverErrorPaths().append("A/a1", 500);
         QVERIFY(!fakeFolder.syncOnce());
         QVERIFY(itemInstruction(completeSpy, "A/a1", CSYNC_INSTRUCTION_NEW));
-        QVERIFY(itemInstruction(completeSpy, "A/a1.owncloud", CSYNC_INSTRUCTION_NONE));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
+        QVERIFY(itemInstruction(completeSpy, "A/a1.nextcloud", CSYNC_INSTRUCTION_NONE));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
-        QCOMPARE(dbRecord(fakeFolder, "A/a1.owncloud")._type, ItemTypeVirtualFileDownload);
+        QCOMPARE(dbRecord(fakeFolder, "A/a1.nextcloud")._type, ItemTypeVirtualFileDownload);
         QVERIFY(!dbRecord(fakeFolder, "A/a1").isValid());
         cleanup();
 
         fakeFolder.serverErrorPaths().clear();
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(itemInstruction(completeSpy, "A/a1", CSYNC_INSTRUCTION_NEW));
-        QVERIFY(itemInstruction(completeSpy, "A/a1.owncloud", CSYNC_INSTRUCTION_NONE));
+        QVERIFY(itemInstruction(completeSpy, "A/a1.nextcloud", CSYNC_INSTRUCTION_NONE));
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
         QCOMPARE(dbRecord(fakeFolder, "A/a1")._type, ItemTypeFile);
-        QVERIFY(!dbRecord(fakeFolder, "A/a1.owncloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a1.nextcloud").isValid());
     }
 
-    // Check what might happen if an older sync client encounters virtual files
-    void testOldVersion1()
+    // Check what happens if vfs mode is disabled
+    void testSwitchOfVfs()
     {
         QSKIP("Does not work with the new discovery because the way we simulate the old client does not work");
         FakeFolder fakeFolder{ FileInfo() };
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
+        SyncOptions syncOptions = vfsSyncOptions();
         fakeFolder.syncEngine().setSyncOptions(syncOptions);
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
 
@@ -422,39 +432,29 @@ private slots:
         fakeFolder.remoteModifier().mkdir("A");
         fakeFolder.remoteModifier().insert("A/a1");
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
 
-        // Simulate an old client by switching the type of all ItemTypeVirtualFile
-        // entries in the db to an invalid type.
-        auto &db = fakeFolder.syncJournal();
-        SyncJournalFileRecord rec;
-        db.getFileRecord(QByteArray("A/a1.owncloud"), &rec);
-        QVERIFY(rec.isValid());
-        QCOMPARE(rec._type, ItemTypeVirtualFile);
-        rec._type = static_cast<ItemType>(-1);
-        db.setFileRecord(rec);
-
-        // Also switch off new files becoming virtual files
-        syncOptions._newFilesAreVirtual = false;
+        // Switch off new files becoming virtual files
+        syncOptions._vfs = nullptr;
         fakeFolder.syncEngine().setSyncOptions(syncOptions);
 
-        // A sync that doesn't do remote discovery has no effect
+        // A sync that doesn't do remote discovery will wipe the placeholder, but not redownload
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.nextcloud"));
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
         QVERIFY(fakeFolder.currentRemoteState().find("A/a1"));
-        QVERIFY(!fakeFolder.currentRemoteState().find("A/a1.owncloud"));
+        QVERIFY(!fakeFolder.currentRemoteState().find("A/a1.nextcloud"));
 
         // But with a remote discovery the virtual files will be removed and
         // the remote files will be downloaded.
-        db.forceRemoteDiscoveryNextSync();
+        fakeFolder.syncJournal().forceRemoteDiscoveryNextSync();
         QVERIFY(fakeFolder.syncOnce());
         QVERIFY(fakeFolder.currentLocalState().find("A/a1"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.nextcloud"));
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
     }
 
-    // Older versions may leave db entries for foo and foo.owncloud
+    // Older versions may leave db entries for foo and foo.nextcloud
     void testOldVersion2()
     {
         QSKIP("Does not work with the new discovery because the way we simulate the old client does not work");
@@ -469,31 +469,27 @@ private slots:
         // Create the virtual file too
         // In the wild, the new version would create the virtual file and the db entry
         // while the old version would download the plain file.
-        fakeFolder.localModifier().insert("A/a1.owncloud");
+        fakeFolder.localModifier().insert("A/a1.nextcloud");
         auto &db = fakeFolder.syncJournal();
         SyncJournalFileRecord rec;
         db.getFileRecord(QByteArray("A/a1"), &rec);
         rec._type = ItemTypeVirtualFile;
-        rec._path = "A/a1.owncloud";
+        rec._path = "A/a1.nextcloud";
         db.setFileRecord(rec);
 
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
-        fakeFolder.syncEngine().setSyncOptions(syncOptions);
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
 
         // Check that a sync removes the virtual file and its db entry
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.nextcloud"));
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
-        QVERIFY(!dbRecord(fakeFolder, "A/a1.owncloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/a1.nextcloud").isValid());
     }
 
     void testDownloadRecursive()
     {
         FakeFolder fakeFolder{ FileInfo() };
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
-        fakeFolder.syncEngine().setSyncOptions(syncOptions);
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
 
         // Create a virtual file for remote files
@@ -512,14 +508,14 @@ private slots:
         fakeFolder.remoteModifier().insert("B/b1");
         fakeFolder.remoteModifier().insert("B/Sub/b2");
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a2.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/Sub/a3.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/Sub/a4.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/Sub/SubSub/a5.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/Sub2/a6.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("B/b1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("B/Sub/b2.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a2.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/Sub/a3.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/Sub/a4.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/Sub/SubSub/a5.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/Sub2/a6.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("B/b1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("B/Sub/b2.nextcloud"));
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
         QVERIFY(!fakeFolder.currentLocalState().find("A/a2"));
         QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/a3"));
@@ -535,14 +531,14 @@ private slots:
         fakeFolder.syncJournal().markVirtualFileForDownloadRecursively("A/Sub");
 
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a2.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/a3.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/a4.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/SubSub/a5.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/Sub2/a6.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("B/b1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("B/Sub/b2.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a2.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/a3.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/a4.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/SubSub/a5.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/Sub2/a6.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("B/b1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("B/Sub/b2.nextcloud"));
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
         QVERIFY(!fakeFolder.currentLocalState().find("A/a2"));
         QVERIFY(fakeFolder.currentLocalState().find("A/Sub/a3"));
@@ -556,21 +552,21 @@ private slots:
         // Currently, this continue to add it as a virtual file.
         fakeFolder.remoteModifier().insert("A/Sub/SubSub/a7");
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(fakeFolder.currentLocalState().find("A/Sub/SubSub/a7.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/Sub/SubSub/a7.nextcloud"));
         QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/SubSub/a7"));
 
         // Now download all files in "A"
         fakeFolder.syncJournal().markVirtualFileForDownloadRecursively("A");
         QVERIFY(fakeFolder.syncOnce());
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a2.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/a3.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/a4.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/SubSub/a5.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub2/a6.owncloud"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/SubSub/a7.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("B/b1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("B/Sub/b2.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a2.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/a3.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/a4.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/SubSub/a5.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub2/a6.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/Sub/SubSub/a7.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("B/b1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("B/Sub/b2.nextcloud"));
         QVERIFY(fakeFolder.currentLocalState().find("A/a1"));
         QVERIFY(fakeFolder.currentLocalState().find("A/a2"));
         QVERIFY(fakeFolder.currentLocalState().find("A/Sub/a3"));
@@ -590,9 +586,7 @@ private slots:
     void testRenameToVirtual()
     {
         FakeFolder fakeFolder{ FileInfo::A12_B12_C12_S12() };
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
-        fakeFolder.syncEngine().setSyncOptions(syncOptions);
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
         QSignalSpy completeSpy(&fakeFolder.syncEngine(), SIGNAL(itemCompleted(const SyncFileItemPtr &)));
 
@@ -601,28 +595,28 @@ private slots:
         };
         cleanup();
 
-        // If a file is renamed to <name>.owncloud, it becomes virtual
-        fakeFolder.localModifier().rename("A/a1", "A/a1.owncloud");
-        // If a file is renamed to <random>.owncloud, the file sticks around (to preserve user data)
-        fakeFolder.localModifier().rename("A/a2", "A/rand.owncloud");
+        // If a file is renamed to <name>.nextcloud, it becomes virtual
+        fakeFolder.localModifier().rename("A/a1", "A/a1.nextcloud");
+        // If a file is renamed to <random>.nextcloud, the file sticks around (to preserve user data)
+        fakeFolder.localModifier().rename("A/a2", "A/rand.nextcloud");
         // dangling virtual files are removed
-        fakeFolder.localModifier().insert("A/dangling.owncloud", 1, ' ');
+        fakeFolder.localModifier().insert("A/dangling.nextcloud", 1, ' ');
         QVERIFY(fakeFolder.syncOnce());
 
         QVERIFY(!fakeFolder.currentLocalState().find("A/a1"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/a1.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
         QVERIFY(fakeFolder.currentRemoteState().find("A/a1"));
-        QVERIFY(itemInstruction(completeSpy, "A/a1.owncloud", CSYNC_INSTRUCTION_NEW));
-        QCOMPARE(dbRecord(fakeFolder, "A/a1.owncloud")._type, ItemTypeVirtualFile);
+        QVERIFY(itemInstruction(completeSpy, "A/a1.nextcloud", CSYNC_INSTRUCTION_NEW));
+        QCOMPARE(dbRecord(fakeFolder, "A/a1.nextcloud")._type, ItemTypeVirtualFile);
 
         QVERIFY(!fakeFolder.currentLocalState().find("A/a2"));
-        QVERIFY(!fakeFolder.currentLocalState().find("A/a2.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("A/rand.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a2.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/rand.nextcloud"));
         QVERIFY(!fakeFolder.currentRemoteState().find("A/a2"));
         QVERIFY(itemInstruction(completeSpy, "A/a2", CSYNC_INSTRUCTION_REMOVE));
-        QVERIFY(!dbRecord(fakeFolder, "A/rand.owncloud").isValid());
+        QVERIFY(!dbRecord(fakeFolder, "A/rand.nextcloud").isValid());
 
-        QVERIFY(!fakeFolder.currentLocalState().find("A/dangling.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/dangling.nextcloud"));
 
         cleanup();
     }
@@ -630,9 +624,7 @@ private slots:
     void testRenameVirtual()
     {
         FakeFolder fakeFolder{ FileInfo() };
-        SyncOptions syncOptions;
-        syncOptions._newFilesAreVirtual = true;
-        fakeFolder.syncEngine().setSyncOptions(syncOptions);
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
         QSignalSpy completeSpy(&fakeFolder.syncEngine(), SIGNAL(itemCompleted(const SyncFileItemPtr &)));
 
@@ -645,30 +637,153 @@ private slots:
         fakeFolder.remoteModifier().insert("file2", 256, 'C');
         QVERIFY(fakeFolder.syncOnce());
 
-        QVERIFY(fakeFolder.currentLocalState().find("file1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("file2.owncloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("file1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("file2.nextcloud"));
         cleanup();
 
-        fakeFolder.localModifier().rename("file1.owncloud", "renamed1.owncloud");
-        fakeFolder.localModifier().rename("file2.owncloud", "renamed2.owncloud");
+        fakeFolder.localModifier().rename("file1.nextcloud", "renamed1.nextcloud");
+        fakeFolder.localModifier().rename("file2.nextcloud", "renamed2.nextcloud");
         triggerDownload(fakeFolder, "file2");
         QVERIFY(fakeFolder.syncOnce());
 
-        QVERIFY(!fakeFolder.currentLocalState().find("file1.owncloud"));
-        QVERIFY(fakeFolder.currentLocalState().find("renamed1.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("file1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("renamed1.nextcloud"));
         QVERIFY(!fakeFolder.currentRemoteState().find("file1"));
         QVERIFY(fakeFolder.currentRemoteState().find("renamed1"));
-        QVERIFY(itemInstruction(completeSpy, "renamed1.owncloud", CSYNC_INSTRUCTION_RENAME));
-        QVERIFY(dbRecord(fakeFolder, "renamed1.owncloud").isValid());
+        QVERIFY(itemInstruction(completeSpy, "renamed1.nextcloud", CSYNC_INSTRUCTION_RENAME));
+        QVERIFY(dbRecord(fakeFolder, "renamed1.nextcloud").isValid());
 
         // file2 has a conflict between the download request and the rename:
         // currently the download wins
-        QVERIFY(!fakeFolder.currentLocalState().find("file2.owncloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("file2.nextcloud"));
         QVERIFY(fakeFolder.currentLocalState().find("file2"));
         QVERIFY(fakeFolder.currentRemoteState().find("file2"));
         QVERIFY(itemInstruction(completeSpy, "file2", CSYNC_INSTRUCTION_NEW));
         QVERIFY(dbRecord(fakeFolder, "file2").isValid());
     }
+
+    // Dehydration via sync works
+    void testSyncDehydration()
+    {
+        FakeFolder fakeFolder{ FileInfo::A12_B12_C12_S12() };
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
+
+        QVERIFY(fakeFolder.syncOnce());
+        QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
+
+        QSignalSpy completeSpy(&fakeFolder.syncEngine(), SIGNAL(itemCompleted(const SyncFileItemPtr &)));
+        auto cleanup = [&]() {
+            completeSpy.clear();
+        };
+        cleanup();
+
+        //
+        // Mark for dehydration and check
+        //
+
+        markForDehydration(fakeFolder, "A/a1");
+
+        markForDehydration(fakeFolder, "A/a2");
+        fakeFolder.remoteModifier().appendByte("A/a2");
+        // expect: normal dehydration
+
+        markForDehydration(fakeFolder, "B/b1");
+        fakeFolder.remoteModifier().remove("B/b1");
+        // expect: local removal
+
+        markForDehydration(fakeFolder, "B/b2");
+        fakeFolder.remoteModifier().rename("B/b2", "B/b3");
+        // expect: B/b2 is gone, B/b3 is NEW placeholder
+
+        markForDehydration(fakeFolder, "C/c1");
+        fakeFolder.localModifier().appendByte("C/c1");
+        // expect: no dehydration, upload of c1
+
+        markForDehydration(fakeFolder, "C/c2");
+        fakeFolder.localModifier().appendByte("C/c2");
+        fakeFolder.remoteModifier().appendByte("C/c2");
+        fakeFolder.remoteModifier().appendByte("C/c2");
+        // expect: no dehydration, conflict
+
+        QVERIFY(fakeFolder.syncOnce());
+
+        auto isDehydrated = [&](const QString &path) {
+            QString placeholder = path + ".nextcloud";
+            return !fakeFolder.currentLocalState().find(path)
+                && fakeFolder.currentLocalState().find(placeholder);
+        };
+
+        QVERIFY(isDehydrated("A/a1"));
+        QVERIFY(isDehydrated("A/a2"));
+
+        QVERIFY(!fakeFolder.currentLocalState().find("B/b1"));
+        QVERIFY(!fakeFolder.currentRemoteState().find("B/b1"));
+        QVERIFY(itemInstruction(completeSpy, "B/b1", CSYNC_INSTRUCTION_REMOVE));
+
+        QVERIFY(!fakeFolder.currentLocalState().find("B/b2"));
+        QVERIFY(!fakeFolder.currentRemoteState().find("B/b2"));
+        QVERIFY(isDehydrated("B/b3"));
+        QVERIFY(itemInstruction(completeSpy, "B/b2", CSYNC_INSTRUCTION_REMOVE));
+        QVERIFY(itemInstruction(completeSpy, "B/b3.nextcloud", CSYNC_INSTRUCTION_NEW));
+
+        QCOMPARE(fakeFolder.currentRemoteState().find("C/c1")->size, 25);
+        QVERIFY(itemInstruction(completeSpy, "C/c1", CSYNC_INSTRUCTION_SYNC));
+
+        QCOMPARE(fakeFolder.currentRemoteState().find("C/c2")->size, 26);
+        QVERIFY(itemInstruction(completeSpy, "C/c2", CSYNC_INSTRUCTION_CONFLICT));
+        cleanup();
+
+        auto expectedLocalState = fakeFolder.currentLocalState();
+        auto expectedRemoteState = fakeFolder.currentRemoteState();
+        QVERIFY(fakeFolder.syncOnce());
+        QCOMPARE(fakeFolder.currentLocalState(), expectedLocalState);
+        QCOMPARE(fakeFolder.currentRemoteState(), expectedRemoteState);
+    }
+
+    void testWipeVirtualSuffixFiles()
+    {
+        FakeFolder fakeFolder{ FileInfo{} };
+        fakeFolder.syncEngine().setSyncOptions(vfsSyncOptions());
+
+        // Create a suffix-vfs baseline
+
+        fakeFolder.remoteModifier().mkdir("A");
+        fakeFolder.remoteModifier().mkdir("A/B");
+        fakeFolder.remoteModifier().insert("f1");
+        fakeFolder.remoteModifier().insert("A/a1");
+        fakeFolder.remoteModifier().insert("A/a3");
+        fakeFolder.remoteModifier().insert("A/B/b1");
+        fakeFolder.localModifier().mkdir("A");
+        fakeFolder.localModifier().mkdir("A/B");
+        fakeFolder.localModifier().insert("f2");
+        fakeFolder.localModifier().insert("A/a2");
+        fakeFolder.localModifier().insert("A/B/b2");
+
+        QVERIFY(fakeFolder.syncOnce());
+
+        QVERIFY(fakeFolder.currentLocalState().find("f1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a3.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/B/b1.nextcloud"));
+
+        // Make local changes to a3
+        fakeFolder.localModifier().remove("A/a3.nextcloud");
+        fakeFolder.localModifier().insert("A/a3.nextcloud", 100);
+
+        // Now wipe the virtuals
+
+        SyncEngine::wipeVirtualFiles(fakeFolder.localPath(), fakeFolder.syncJournal(), fakeFolder.syncEngine().syncOptions()._vfs);
+
+        QVERIFY(!fakeFolder.currentLocalState().find("f1.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/a1.nextcloud"));
+        QVERIFY(fakeFolder.currentLocalState().find("A/a3.nextcloud"));
+        QVERIFY(!fakeFolder.currentLocalState().find("A/B/b1.nextcloud"));
+
+        fakeFolder.syncEngine().setSyncOptions(SyncOptions{});
+        QVERIFY(fakeFolder.syncOnce());
+        QVERIFY(fakeFolder.currentRemoteState().find("A/a3.nextcloud")); // regular upload
+        QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
+    }
 };
 
 QTEST_GUILESS_MAIN(TestSyncVirtualFiles)