Move the file-cloning code from QFSFileEngine to QFileSystemEngine

Change-Id: I02d22222fff64d4dbda4fffd14d1c1bbf48385ff
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

src/corelib/io/qfilesystemengine_p.h

@@ -91,6 +91,7 @@ public:
     static bool fillMetaData(const QFileSystemEntry &entry, QFileSystemMetaData &data,
                              QFileSystemMetaData::MetaDataFlags what);
 #if defined(Q_OS_UNIX)
+    static bool cloneFile(int srcfd, int dstfd, const QFileSystemMetaData &knownData);
     static bool fillMetaData(int fd, QFileSystemMetaData &data); // what = PosixStatFlags
     static QByteArray id(int fd);
     static bool setFileTime(int fd, const QDateTime &newDate,

src/corelib/io/qfilesystemengine_unix.cpp

@@ -78,9 +78,16 @@ extern "C" NSString *NSTemporaryDirectory();
 #endif
 
 #if defined(Q_OS_LINUX)
+#  include <sys/ioctl.h>
 #  include <sys/syscall.h>
+#  include <sys/sendfile.h>
 #  include <linux/fs.h>
 
+// in case linux/fs.h is too old and doesn't define it:
+#ifndef FICLONE
+#  define FICLONE       _IOW(0x94, 9, int)
+#endif
+
 #  if !QT_CONFIG(renameat2) && defined(SYS_renameat2)
 static int renameat2(int oldfd, const char *oldpath, int newfd, const char *newpath, unsigned flags)
 { return syscall(SYS_renameat2, oldfd, oldpath, newfd, newpath, flags); }
@@ -1065,6 +1072,19 @@ bool QFileSystemEngine::fillMetaData(const QFileSystemEntry &entry, QFileSystemM
     return data.hasFlags(what);
 }
 
+// static
+bool QFileSystemEngine::cloneFile(int srcfd, int dstfd, const QFileSystemMetaData &knownData)
+{
+#if defined(Q_OS_LINUX)
+    // try FICLONE (only works on regular files and only on certain fs)
+    return ::ioctl(dstfd, FICLONE, srcfd) == 0;
+#else
+    Q_UNUSED(srcfd);
+    Q_UNUSED(dstfd);
+    return false;
+#endif
+}
+
 // Note: if \a shouldMkdirFirst is false, we assume the caller did try to mkdir
 // before calling this function.
 static bool createDirectoryWithParents(const QByteArray &nativeName, bool shouldMkdirFirst = true)

src/corelib/io/qfsfileengine_unix.cpp

@@ -737,19 +737,13 @@ bool QFSFileEnginePrivate::unmap(uchar *ptr)
 */
 bool QFSFileEngine::cloneTo(QAbstractFileEngine *target)
 {
+    Q_D(QFSFileEngine);
     if ((target->fileFlags(LocalDiskFlag) & LocalDiskFlag) == 0)
         return false;
-#if defined(Q_OS_LINUX)
-    Q_D(QFSFileEngine);
-#  if !defined FICLONE
-#    define FICLONE _IOW (0x94, 9, int)
-#  endif
+
     int srcfd = d->nativeHandle();
     int dstfd = target->handle();
-    return ::ioctl(dstfd, FICLONE, srcfd) == 0;
-#else
-    return false;
-#endif
+    return QFileSystemEngine::cloneFile(srcfd, dstfd, d->metaData);
 }
 
 QT_END_NAMESPACE