Do a sanity check when mounting the file system and fail if the root blob is not available.

src/cryfs/cli/Cli.cpp

@@ -18,6 +18,7 @@
 #include <boost/filesystem.hpp>
 
 #include <gitversion/version.h>
+#include <cryfs/filesystem/CryDir.h>
 
 #include "VersionChecker.h"
 
@@ -60,6 +61,7 @@ using boost::chrono::duration;
 using boost::chrono::duration_cast;
 using boost::chrono::minutes;
 using boost::chrono::milliseconds;
+using cpputils::dynamic_pointer_move;
 
 //TODO Delete a large file in parallel possible? Takes a long time right now...
 //TODO Improve parallelity.
@@ -197,6 +199,7 @@ namespace cryfs {
             auto blockStore = make_unique_ref<OnDiskBlockStore>(options.baseDir());
             auto config = _loadOrCreateConfig(options);
             CryDevice device(std::move(config), std::move(blockStore));
+            _sanityCheckFilesystem(&device);
             fspp::FilesystemImpl fsimpl(&device);
             fspp::fuse::Fuse fuse(&fsimpl);
 
@@ -223,6 +226,19 @@ namespace cryfs {
         }
     }
 
+    void Cli::_sanityCheckFilesystem(CryDevice *device) {
+        //Try to list contents of base directory
+        auto _rootDir = device->Load("/"); // this might throw an exception if the root blob doesn't exist
+        if (_rootDir == none) {
+            throw std::runtime_error("Couldn't find root blob");
+        }
+        auto rootDir = dynamic_pointer_move<CryDir>(*_rootDir);
+        if (rootDir == none) {
+            throw std::runtime_error("Base directory blob doesn't contain a directory");
+        }
+        (*rootDir)->children(); // Load children
+    }
+
     optional<unique_ref<CallAfterTimeout>> Cli::_createIdleCallback(optional<double> minutes, function<void()> callback) {
         if (minutes == none) {
             return none;

src/cryfs/cli/Cli.h

@@ -9,6 +9,7 @@
 #include <cpp-utils/io/Console.h>
 #include <cpp-utils/random/RandomGenerator.h>
 #include <cpp-utils/network/HttpClient.h>
+#include <cryfs/filesystem/CryDevice.h>
 #include "CallAfterTimeout.h"
 
 namespace cryfs {
@@ -36,6 +37,7 @@ namespace cryfs {
         std::shared_ptr<cpputils::TempFile> _checkDirWriteable(const boost::filesystem::path &dir, const std::string &name);
         void _checkDirReadable(const boost::filesystem::path &dir, std::shared_ptr<cpputils::TempFile> tempfile, const std::string &name);
         boost::optional<cpputils::unique_ref<CallAfterTimeout>> _createIdleCallback(boost::optional<double> minutes, std::function<void()> callback);
+        void _sanityCheckFilesystem(CryDevice *device);
 
         cpputils::RandomGenerator &_keyGenerator;
         cpputils::SCryptSettings _scryptSettings;

src/cryfs/filesystem/CryDevice.cpp

@@ -74,7 +74,7 @@ optional<unique_ref<fspp::Node>> CryDevice::Load(const bf::path &path) {
   callFsActionCallbacks();
 
   if (path.parent_path().empty()) {
-    //We are asked to load the root directory '/'.
+    //We are asked to load the base directory '/'.
     return optional<unique_ref<fspp::Node>>(make_unique_ref<CryDir>(this, none, _rootKey));
   }
   auto parent = LoadDirBlob(path.parent_path());
@@ -165,7 +165,7 @@ unique_ref<SymlinkBlobRef> CryDevice::CreateSymlinkBlob(const bf::path &target)
 unique_ref<FsBlobRef> CryDevice::LoadBlob(const blockstore::Key &key) {
   auto blob = _fsBlobStore->load(key);
   if (blob == none) {
-    LOG(ERROR) << "Could not load blob " << key.ToString() << ". Is the root directory accessible?";
+    LOG(ERROR) << "Could not load blob " << key.ToString() << ". Is the base directory accessible?";
     throw FuseErrnoException(EIO);
   }
   return std::move(*blob);
@@ -174,7 +174,7 @@ unique_ref<FsBlobRef> CryDevice::LoadBlob(const blockstore::Key &key) {
 void CryDevice::RemoveBlob(const blockstore::Key &key) {
   auto blob = _fsBlobStore->load(key);
   if (blob == none) {
-    LOG(ERROR) << "Could not load blob " << key.ToString() << ". Is the root directory accessible?";
+    LOG(ERROR) << "Could not load blob " << key.ToString() << ". Is the base directory accessible?";
     throw FuseErrnoException(EIO);
   }
   _fsBlobStore->remove(std::move(*blob));

src/cryfs/filesystem/CryNode.cpp

@@ -44,7 +44,7 @@ void CryNode::access(int mask) const {
 void CryNode::rename(const bf::path &to) {
   device()->callFsActionCallbacks();
   if (_parent == none) {
-    //We are the root direcory.
+    //We are the base direcory.
     //TODO What should we do?
     throw FuseErrnoException(EIO);
   }
@@ -67,7 +67,7 @@ void CryNode::rename(const bf::path &to) {
 void CryNode::utimens(timespec lastAccessTime, timespec lastModificationTime) {
   device()->callFsActionCallbacks();
   if (_parent == none) {
-    //We are the root direcory.
+    //We are the base direcory.
     //TODO What should we do?
     throw FuseErrnoException(EIO);
   }
@@ -77,7 +77,7 @@ void CryNode::utimens(timespec lastAccessTime, timespec lastModificationTime) {
 void CryNode::removeNode() {
   //TODO Instead of all these if-else and having _parent being an optional, we could also introduce a CryRootDir which inherits from fspp::Dir.
   if (_parent == none) {
-    //We are the root direcory.
+    //We are the base direcory.
     //TODO What should we do?
     throw FuseErrnoException(EIO);
   }
@@ -100,7 +100,7 @@ unique_ref<FsBlobRef> CryNode::LoadBlob() const {
 void CryNode::stat(struct ::stat *result) const {
   device()->callFsActionCallbacks();
   if(_parent == none) {
-    //We are the root directory.
+    //We are the base directory.
 	//TODO What should we do?
     result->st_uid = getuid();
     result->st_gid = getgid();
@@ -114,7 +114,7 @@ void CryNode::stat(struct ::stat *result) const {
 void CryNode::chmod(mode_t mode) {
   device()->callFsActionCallbacks();
   if (_parent == none) {
-    //We are the root direcory.
+    //We are the base direcory.
 	//TODO What should we do?
 	throw FuseErrnoException(EIO);
   }
@@ -124,7 +124,7 @@ void CryNode::chmod(mode_t mode) {
 void CryNode::chown(uid_t uid, gid_t gid) {
   device()->callFsActionCallbacks();
   if (_parent == none) {
-	//We are the root direcory.
+	//We are the base direcory.
 	//TODO What should we do?
 	throw FuseErrnoException(EIO);
   }

src/fspp/fuse/Fuse.cpp

@@ -275,7 +275,7 @@ int Fuse::fgetattr(const bf::path &path, struct stat *stbuf, fuse_file_info *fil
   // On FreeBSD, trying to do anything with the mountpoint ends up
   // opening it, and then using the FD for an fgetattr.  So in the
   // special case of a path of "/", I need to do a getattr on the
-  // underlying root directory instead of doing the fgetattr().
+  // underlying base directory instead of doing the fgetattr().
   // TODO Check if necessary
   if (path.native() == "/") {
     return getattr(path, stbuf);