Notify user if there is a problem with the inotify watcher

src/mirall/folder.cpp

@@ -302,6 +302,11 @@ void Folder::slotThreadTreeWalkResult(const SyncFileItemVector& items)
     _syncResult.setSyncFileItemVector(items);
 }
 
+void Folder::slotCatchWatcherError(const QString& error)
+{
+    Logger::instance()->postGuiLog(tr("Error"), error);
+}
+
 void Folder::slotTerminateSync()
 {
     qDebug() << "folder " << alias() << " Terminating!";

src/mirall/folder.h

@@ -177,6 +177,7 @@ private slots:
      */
     void slotLocalPathChanged( const QString& );
     void slotThreadTreeWalkResult(const SyncFileItemVector& );
+    void slotCatchWatcherError( const QString& );
 
 protected:
     bool init();

src/mirall/folderwatcher.h

@@ -43,7 +43,7 @@ class FolderWatcherPrivate;
  */
 class FolderWatcher : public QObject
 {
-Q_OBJECT
+    Q_OBJECT
 public:
     /**
      * @param root Path of the root of the folder
@@ -104,10 +104,10 @@ public slots:
     void setEventsEnabledDelayed( int );
 
 signals:
-    /**
-     * Emitted when one of the paths is changed
-     */
+    /** Emitted when one of the paths is changed */
     void folderChanged(const QStringList &pathList);
+    /** Emitted if an error occurs */
+    void error(const QString& error);
 
 protected:
     void setProcessTimer();

src/mirall/folderwatcher_inotify.cpp

@@ -49,7 +49,12 @@ void FolderWatcherPrivate::slotAddFolderRecursive(const QString &path)
     int subdirs = 0;
     qDebug() << "(+) Watcher:" << path;
 
-    _inotify->addPath(path);
+    if (!_inotify->addPath(path)) {
+        FolderWatcher *fw = qobject_cast<FolderWatcher*>(parent());
+        emit fw->error(tr("Could not monitor directories due to system limitations.\n"
+                          "The application will not work reliably. Please check the\n"
+                          "documentation for possible fixes."));
+    }
     QStringList watchedFolders(_inotify->directories());
     // qDebug() << "currently watching " << watchedFolders;
     QStringListIterator subfoldersIt(FileUtils::subFoldersList(path, FileUtils::SubFolderRecursive));

src/mirall/folderwatcher_inotify.h

@@ -26,6 +26,8 @@ class FolderWatcherPrivate : public QObject {
     Q_OBJECT
 public:
     FolderWatcherPrivate(FolderWatcher *p);
+signals:
+    void error(const QString& error);
 private slots:
     void slotAddFolderRecursive(const QString &path);
     void slotINotifyEvent(int mask, int cookie, const QString &path);

src/mirall/inotify.cpp

@@ -115,14 +115,17 @@ INotify::~INotify()
     delete _notifier;
 }
 
-void INotify::addPath(const QString &path)
+bool INotify::addPath(const QString &path)
 {
     // Add an inotify watch.
     int wd = inotify_add_watch(_fd, path.toUtf8().constData(), _mask);
-    if( wd > -1 )
+    if( wd > -1 ) {
         _wds[path] = wd;
-    else
+        return true;
+    } else {
         qDebug() << "WRN: Could not watch " << path << ':' << strerror(errno);
+        return false;
+    }
 }
 
 void INotify::removePath(const QString &path)

src/mirall/inotify.h

@@ -38,7 +38,7 @@ public:
     INotify(QObject *parent, int mask);
     ~INotify();
 
-    void addPath(const QString &name);
+    bool addPath(const QString &name);
     void removePath(const QString &name);
 
     QStringList directories() const;