Linux: overwrite start and end of the drive with zeroes when restoring

Similar to Windows, overwrite the beginning of the drive and the end of
the drive with zeroes before creating a new partition table. This is to
make sure there are no partition table residues after a Fedora image was
written onto the drive.

Resolves FedoraQt#575

src/helper/linux/CMakeLists.txt

@@ -8,6 +8,7 @@ include_directories(
 
 set(HELPER_SRCS
     main.cpp
+    job.cpp
     restorejob.cpp
     writejob.cpp
 )

src/helper/linux/job.cpp

@@ -0,0 +1,80 @@
+/*
+ * Fedora Media Writer
+ * Copyright (C) 2024 Jan Grulich <[email protected]>
+ * Copyright (C) 2016 Martin Bříza <[email protected]>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include "job.h"
+
+#include <QtDBus>
+#include <QDBusArgument>
+#include <QDBusInterface>
+
+Q_DECLARE_METATYPE(Properties)
+Q_DECLARE_METATYPE(InterfacesAndProperties)
+Q_DECLARE_METATYPE(DBusIntrospection)
+
+Job::Job(const QString& where)
+    : Job(QString(), where) { }
+
+Job::Job(const QString &what, const QString &where)
+    : what(what), where(where)
+{
+    qDBusRegisterMetaType<Properties>();
+    qDBusRegisterMetaType<InterfacesAndProperties>();
+    qDBusRegisterMetaType<DBusIntrospection>();
+}
+
+QDBusUnixFileDescriptor Job::getDescriptor()
+{
+    QDBusInterface device("org.freedesktop.UDisks2", where, "org.freedesktop.UDisks2.Block", QDBusConnection::systemBus(), this);
+    QString drivePath = qvariant_cast<QDBusObjectPath>(device.property("Drive")).path();
+    QDBusInterface manager("org.freedesktop.UDisks2", "/org/freedesktop/UDisks2", "org.freedesktop.DBus.ObjectManager", QDBusConnection::systemBus());
+    QDBusMessage message = manager.call("GetManagedObjects");
+
+    if (message.arguments().length() == 1) {
+        QDBusArgument arg = qvariant_cast<QDBusArgument>(message.arguments().first());
+        DBusIntrospection objects;
+        arg >> objects;
+        for (auto i : objects.keys()) {
+            if (objects[i].contains("org.freedesktop.UDisks2.Filesystem")) {
+                QString currentDrivePath = qvariant_cast<QDBusObjectPath>(objects[i]["org.freedesktop.UDisks2.Block"]["Drive"]).path();
+                if (currentDrivePath == drivePath) {
+                    QDBusInterface partition("org.freedesktop.UDisks2", i.path(), "org.freedesktop.UDisks2.Filesystem", QDBusConnection::systemBus());
+                    message = partition.call("Unmount", Properties{{"force", true}});
+                }
+            }
+        }
+    } else {
+        err << message.errorMessage();
+        err.flush();
+        qApp->exit(2);
+        return QDBusUnixFileDescriptor(-1);
+    }
+
+    QDBusReply<QDBusUnixFileDescriptor> reply = device.call(QDBus::Block, "OpenDevice", "rw", Properties{{"flags", O_DIRECT | O_SYNC | O_CLOEXEC}});
+    QDBusUnixFileDescriptor fd = reply.value();
+
+    if (!fd.isValid()) {
+        err << reply.error().message();
+        err.flush();
+        qApp->exit(2);
+        return QDBusUnixFileDescriptor(-1);
+    }
+
+    return fd;
+}

src/helper/linux/job.h

@@ -0,0 +1,62 @@
+/*
+ * Fedora Media Writer
+ * Copyright (C) 2024 Jan Grulich <[email protected]>
+ * Copyright (C) 2016 Martin Bříza <[email protected]>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#ifndef JOB_H
+#define JOB_H
+
+#include <QDBusUnixFileDescriptor>
+#include <QDBusObjectPath>
+#include <QObject>
+#include <QTextStream>
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <memory>
+#include <tuple>
+
+typedef QHash<QString, QVariant> Properties;
+typedef QHash<QString, Properties> InterfacesAndProperties;
+typedef QHash<QDBusObjectPath, InterfacesAndProperties> DBusIntrospection;
+
+class Job : public QObject
+{
+    Q_OBJECT
+public:
+    explicit Job(const QString &where);
+    Job(const QString &what, const QString &where);
+
+    QDBusUnixFileDescriptor getDescriptor();
+
+public slots:
+    virtual void work() = 0;
+
+protected:
+    QString what;
+    QString where;
+    QTextStream out{stdout};
+    QTextStream err{stderr};
+    QDBusUnixFileDescriptor fd{-1};
+};
+
+std::tuple<std::unique_ptr<char[]>, char *, std::size_t> pageAlignedBuffer(std::size_t pages = 1024);
+
+#endif // JOB_H
+

src/helper/linux/restorejob.cpp

@@ -1,5 +1,6 @@
 /*
  * Fedora Media Writer
+ * Copyright (C) 2024 Jan Grulich <[email protected]>
  * Copyright (C) 2016 Martin Bříza <[email protected]>
  *
  * This program is free software; you can redistribute it and/or
@@ -20,24 +21,19 @@
 #include "restorejob.h"
 
 #include <QCoreApplication>
-#include <QTextStream>
 #include <QThread>
 #include <QTimer>
 
+#include <QDBusArgument>
 #include <QDBusInterface>
-#include <QDBusUnixFileDescriptor>
-#include <QtDBus>
+#include <QDBusMessage>
+#include <QDBusReply>
 
-typedef QHash<QString, QVariant> Properties;
-typedef QHash<QString, Properties> InterfacesAndProperties;
-typedef QHash<QDBusObjectPath, InterfacesAndProperties> DBusIntrospection;
-Q_DECLARE_METATYPE(Properties)
-Q_DECLARE_METATYPE(InterfacesAndProperties)
-Q_DECLARE_METATYPE(DBusIntrospection)
+#include <stdio.h>
+#include <sys/types.h>
 
 RestoreJob::RestoreJob(const QString &where)
-    : QObject(nullptr)
-    , where(where)
+    : Job(where)
 {
     QTimer::singleShot(0, this, SLOT(work()));
 }
@@ -65,7 +61,70 @@ void RestoreJob::work()
         }
     }
 
-    QDBusReply<void> formatReply = device.call("Format", "dos", Properties());
+    // Wipe out first and last 128 blocks with zeroes
+    fd = getDescriptor();
+    if (fd.fileDescriptor() < 0) {
+        err << tr("Failed to open device for writing");
+        err.flush();
+        qApp->exit(1);
+    }
+
+    auto bufferOwner = pageAlignedBuffer();
+    char *buffer = std::get<1>(bufferOwner);
+    qint64 size = std::get<2>(bufferOwner);
+
+    memset(buffer, '\0', size);
+
+    // Overwrite first 128 blocks with zeroes
+    for (int i = 0; i < 128; i++) {
+        qint64 written = ::write(fd.fileDescriptor(), buffer, size);
+        if (written != size) {
+            err << tr("Destination drive is not writable");
+            err.flush();
+            qApp->exit(1);
+        }
+    }
+
+    // Rewind the filepointer to the last 128 blocks
+    off_t filesize = lseek(fd.fileDescriptor(), 0, SEEK_END);
+    if (filesize == static_cast<off_t>(-1)) {
+        err << tr("Failed to get file size");
+        err.flush();
+        qApp->exit(1);
+    }
+
+    off_t offset = filesize - (128 * size);
+    if (offset < 0) {
+        err << tr("File size is smaller than 128 blocks");
+        err.flush();
+        qApp->exit(1);
+    }
+
+    // Move the file pointer to the calculated offset
+    if (lseek(fd.fileDescriptor(), offset, SEEK_SET) == static_cast<off_t>(-1)) {
+        err << tr("Failed to move file pointer to the end region");
+        err.flush();
+        qApp->exit(1);
+    }
+
+    // Overwrite last 128 blocks with zeroes
+    for (int i = 0; i < 128; i++) {
+        qint64 written = ::write(fd.fileDescriptor(), buffer, size);
+        if (written != size) {
+            err << tr("Destination drive is not writable");
+            err.flush();
+            qApp->exit(1);
+        }
+    }
+
+    // Ensure data is flushed to disk
+    if (::fsync(fd.fileDescriptor()) == -1) {
+        err << tr("Failed to sync data to disk");
+        err.flush();
+        qApp->exit(1);
+    }
+
+    QDBusReply<void> formatReply = device.call("Format", "gpt", Properties());
     if (!formatReply.isValid() && formatReply.error().type() != QDBusError::NoReply) {
         err << formatReply.error().message() << "\n";
         err.flush();

src/helper/linux/restorejob.h

@@ -1,5 +1,6 @@
 /*
  * Fedora Media Writer
+ * Copyright (C) 2024 Jan Grulich <[email protected]>
  * Copyright (C) 2016 Martin Bříza <[email protected]>
  *
  * This program is free software; you can redistribute it and/or
@@ -20,22 +21,16 @@
 #ifndef RESTOREJOB_H
 #define RESTOREJOB_H
 
-#include <QObject>
-#include <QTextStream>
+#include "job.h"
 
-class RestoreJob : public QObject
+class RestoreJob : public Job
 {
     Q_OBJECT
 public:
     explicit RestoreJob(const QString &where);
-public slots:
-    void work();
-
-private:
-    QTextStream out{stdout};
-    QTextStream err{stderr};
 
-    QString where;
+public slots:
+    void work() override;
 };
 
 #endif // RESTOREJOB_H

src/helper/linux/writejob.cpp

@@ -1,5 +1,6 @@
 /*
  * Fedora Media Writer
+ * Copyright (C) 2024 Jan Grulich <[email protected]>
  * Copyright (C) 2016 Martin Bříza <[email protected]>
  *
  * This program is free software; you can redistribute it and/or
@@ -21,41 +22,17 @@
 
 #include <QCoreApplication>
 #include <QProcess>
-#include <QTextStream>
 #include <QTimer>
+#include <QRegularExpression>
 #include <QtGlobal>
 
-#include <QDBusInterface>
-#include <QDBusUnixFileDescriptor>
-#include <QtDBus>
-
-#include <fcntl.h>
-#include <unistd.h>
-
-#include <tuple>
-#include <utility>
-
 #include <lzma.h>
 
 #include "isomd5/libcheckisomd5.h"
 
-#include <QDebug>
-
-typedef QHash<QString, QVariant> Properties;
-typedef QHash<QString, Properties> InterfacesAndProperties;
-typedef QHash<QDBusObjectPath, InterfacesAndProperties> DBusIntrospection;
-Q_DECLARE_METATYPE(Properties)
-Q_DECLARE_METATYPE(InterfacesAndProperties)
-Q_DECLARE_METATYPE(DBusIntrospection)
-
 WriteJob::WriteJob(const QString &what, const QString &where)
-    : QObject(nullptr)
-    , what(what)
-    , where(where)
+    : Job(what, where)
 {
-    qDBusRegisterMetaType<Properties>();
-    qDBusRegisterMetaType<InterfacesAndProperties>();
-    qDBusRegisterMetaType<DBusIntrospection>();
     connect(&watcher, &QFileSystemWatcher::fileChanged, this, &WriteJob::onFileChanged);
     QTimer::singleShot(0, this, SLOT(work()));
 }
@@ -73,46 +50,6 @@ int WriteJob::onMediaCheckAdvanced(long long offset, long long total)
     return 0;
 }
 
-QDBusUnixFileDescriptor WriteJob::getDescriptor()
-{
-    QDBusInterface device("org.freedesktop.UDisks2", where, "org.freedesktop.UDisks2.Block", QDBusConnection::systemBus(), this);
-    QString drivePath = qvariant_cast<QDBusObjectPath>(device.property("Drive")).path();
-    QDBusInterface manager("org.freedesktop.UDisks2", "/org/freedesktop/UDisks2", "org.freedesktop.DBus.ObjectManager", QDBusConnection::systemBus());
-    QDBusMessage message = manager.call("GetManagedObjects");
-
-    if (message.arguments().length() == 1) {
-        QDBusArgument arg = qvariant_cast<QDBusArgument>(message.arguments().first());
-        DBusIntrospection objects;
-        arg >> objects;
-        for (auto i : objects.keys()) {
-            if (objects[i].contains("org.freedesktop.UDisks2.Filesystem")) {
-                QString currentDrivePath = qvariant_cast<QDBusObjectPath>(objects[i]["org.freedesktop.UDisks2.Block"]["Drive"]).path();
-                if (currentDrivePath == drivePath) {
-                    QDBusInterface partition("org.freedesktop.UDisks2", i.path(), "org.freedesktop.UDisks2.Filesystem", QDBusConnection::systemBus());
-                    message = partition.call("Unmount", Properties{{"force", true}});
-                }
-            }
-        }
-    } else {
-        err << message.errorMessage();
-        err.flush();
-        qApp->exit(2);
-        return QDBusUnixFileDescriptor(-1);
-    }
-
-    QDBusReply<QDBusUnixFileDescriptor> reply = device.call(QDBus::Block, "OpenDevice", "rw", Properties{{"flags", O_DIRECT | O_SYNC | O_CLOEXEC}});
-    QDBusUnixFileDescriptor fd = reply.value();
-
-    if (!fd.isValid()) {
-        err << reply.error().message();
-        err.flush();
-        qApp->exit(2);
-        return QDBusUnixFileDescriptor(-1);
-    }
-
-    return fd;
-}
-
 bool WriteJob::write(int fd)
 {
     if (what.endsWith(".xz"))