File indexing completed on 2024-04-21 16:30:24

 // SPDX-FileCopyrightText: 2020 Simon Persson <simon.persson@mykolab.com>
 //
 // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
 
 #include "fsexecutor.h"
 #include "backupplan.h"
 
 #include <QAction>
 #include <QDir>
 #include <QFileInfo>
 #include <QTimer>
 #include <QTextStream>
 
 #include <KDirWatch>
 
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/select.h>
 
 namespace {
 
 // very light check if a directory exists that works on automounts where QDir::exists fails
 bool checkDirExists(const QDir &dir)
 {
     struct stat s;
     return stat(dir.absolutePath().toLocal8Bit().data(), &s) == 0 && S_ISDIR(s.st_mode);
 }
 }
 
 FSExecutor::FSExecutor(BackupPlan *pPlan, KupDaemon *pKupDaemon)
    :PlanExecutor(pPlan, pKupDaemon)
 {
     mDestinationPath = QDir::cleanPath(mPlan->mFilesystemDestinationPath.toLocalFile());
     mDirWatch = new KDirWatch(this);
     connect(mDirWatch, SIGNAL(deleted(QString)), SLOT(checkStatus()));
     mMountWatcher.start();
 }
 
 FSExecutor::~FSExecutor() {
     mMountWatcher.terminate();
     mMountWatcher.wait();
 }
 
 void FSExecutor::checkStatus() {
     static bool lComingBackLater = false;
     if(!mWatchedParentDir.isEmpty() && !lComingBackLater) {
         // came here because something happened to a parent folder,
         // come back in a few seconds, give a new mount some time before checking
         // status of destination folder
         QTimer::singleShot(5000, this, SLOT(checkStatus()));
         lComingBackLater = true;
         return;
     }
     lComingBackLater = false;
 
     QDir lDir(mDestinationPath);
     if(!lDir.exists()) {
         // Destination doesn't exist, find nearest existing parent folder and
         // watch that for dirty or deleted
         if(mDirWatch->contains(mDestinationPath)) {
             mDirWatch->removeDir(mDestinationPath);
         }
 
         QString lExisting = mDestinationPath;
         do {
             lExisting += QStringLiteral("/..");
             lDir = QDir(QDir::cleanPath(lExisting));
         } while(!checkDirExists(lDir));
         lExisting = lDir.canonicalPath();
 
         if(lExisting != mWatchedParentDir) { // new parent to watch
             if(!mWatchedParentDir.isEmpty()) { // were already watching a parent
                 mDirWatch->removeDir(mWatchedParentDir);
             } else { // start watching a parent
                 connect(mDirWatch, SIGNAL(dirty(QString)), SLOT(checkStatus()));
                 connect(&mMountWatcher, SIGNAL(mountsChanged()), SLOT(checkMountPoints()), Qt::QueuedConnection);
             }
             mWatchedParentDir = lExisting;
             mDirWatch->addDir(mWatchedParentDir);
         }
         if(mState != NOT_AVAILABLE) {
             enterNotAvailableState();
         }
     } else {
         // Destination exists... only watch for delete
         if(!mWatchedParentDir.isEmpty()) {
             disconnect(mDirWatch, SIGNAL(dirty(QString)), this, SLOT(checkStatus()));
             disconnect(&mMountWatcher, SIGNAL(mountsChanged()), this, SLOT(checkMountPoints()));
             mDirWatch->removeDir(mWatchedParentDir);
             mWatchedParentDir.clear();
         }
         mDirWatch->addDir(mDestinationPath);
 
         QFileInfo lInfo(mDestinationPath);
         if(lInfo.isWritable() && mState == NOT_AVAILABLE) {
             enterAvailableState();
         }else if(!lInfo.isWritable() && mState != NOT_AVAILABLE) {
             enterNotAvailableState();
         }
     }
 }
 
 
 void FSExecutor::checkMountPoints() {
     QFile lMountsFile(QStringLiteral("/proc/mounts"));
     if(!lMountsFile.open(QIODevice::ReadOnly | QIODevice::Text)) {
         return;
     }
     // don't use atEnd() to detect when finished reading file, size of
     // this special file is 0 but still returns data when read.
     forever {
         QByteArray lLine = lMountsFile.readLine();
         if(lLine.isEmpty()) {
             break;
         }
         QTextStream lTextStream(lLine);
         QString lDevice, lMountPoint;
         lTextStream >> lDevice >> lMountPoint;
         if(lMountPoint == mWatchedParentDir) {
             checkStatus();
         }
     }
 }
 
 void MountWatcher::run() {
     int lMountsFd = open("/proc/mounts", O_RDONLY);
     fd_set lFdSet;
 
     forever {
         FD_ZERO(&lFdSet);
         FD_SET(lMountsFd, &lFdSet);
         if(select(lMountsFd+1, nullptr, nullptr, &lFdSet, nullptr) > 0) {
             emit mountsChanged();
         }
     }
 }