[libcalamares] Add settle / sync support method

src/libcalamares/CMakeLists.txt

@@ -37,6 +37,7 @@ set( libSources
 
     # Partition service
     partition/PartitionSize.cpp
+    partition/Sync.cpp
 
     # Utility service
     utils/CalamaresUtilsSystem.cpp

src/libcalamares/partition/Sync.cpp

@@ -0,0 +1,47 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares 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 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares 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 Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Sync.h"
+
+#include "utils/CalamaresUtilsSystem.h"
+#include "utils/Logger.h"
+
+void CalamaresUtils::Partition::sync()
+{
+    auto* s = CalamaresUtils::System::instance();
+
+    auto r = s->runCommand( CalamaresUtils::System::RunLocation::RunInHost,
+                   { "/sbin/udevadm", "settle" },
+                   QString(),
+                   QString(),
+                   10 // timeout seconds
+    );
+
+    if ( r.getExitCode() != 0 )
+    {
+        cWarning() << "Could not settle disks.";
+        r.explainProcess( "udevadm", 10 );
+    }
+
+    s->runCommand( CalamaresUtils::System::RunLocation::RunInHost,
+                   { "/bin/sync" },
+                   QString(),
+                   QString(),
+                   10 // timeout seconds
+    );
+}

src/libcalamares/partition/Sync.h

@@ -0,0 +1,49 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares 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 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares 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 Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef PARTITION_SYNC_H
+#define PARTITION_SYNC_H
+
+namespace CalamaresUtils
+{
+namespace Partition
+{
+
+/** @brief Run "udevadm settle" or other disk-sync mechanism.
+ *
+ * Call this after mounting, unmount, toggling swap, or other functions
+ * that might cause the disk to be "busy" for other disk-modifying
+ * actions (in particular, KPMcore actions with the sfdisk backend
+ * are sensitive, and systemd tends to keep disks busy after a change
+ * for a while).
+ */
+void sync();
+
+/** @brief RAII class for calling sync() */
+struct Syncer
+{
+    ~Syncer()
+    {
+        sync();
+    }
+};
+
+}
+}
+
+#endif