From ddd3a8a329cdc2c73c68db273bf37a5c725f3e94 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-Pierre=20Andr=C3=A9?= <jpandre@users.sourceforge.net>
Date: Tue, 11 Mar 2014 09:54:53 +0100
Subject: [PATCH] Reset the output file to favour appending to image in
 ntfsclone

When ntfsclone'ing to a file, the target file was truncated to the volume
size. This is not useful on file systems which support sparse files. In
the case of ntfs-3g this leads to prevent optimizations specific to
appending data. So when a sparse output file is detected, it is emptied
to benefit from subsequent appending of data.
---
 include/ntfs-3g/device_io.h |  2 +-
 ntfsprogs/ntfsclone.c       | 25 +++++++++++++++++++++++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/include/ntfs-3g/device_io.h b/include/ntfs-3g/device_io.h
index 24f8d9bf..66ad2439 100644
--- a/include/ntfs-3g/device_io.h
+++ b/include/ntfs-3g/device_io.h
@@ -72,7 +72,7 @@ struct hd_geometry {
 /* A few useful functions */
 int ntfs_win32_set_sparse(int);
 int ntfs_win32_ftruncate(int fd, s64 size);
-int ntfs_win32_device_ftruncate(struct ntfs_device*, s64);
+int ntfs_device_win32_ftruncate(struct ntfs_device*, s64);
 
 #endif /* HAVE_WINDOWS_H */
 
diff --git a/ntfsprogs/ntfsclone.c b/ntfsprogs/ntfsclone.c
index 481ebf34..33d76d8a 100644
--- a/ntfsprogs/ntfsclone.c
+++ b/ntfsprogs/ntfsclone.c
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2003-2006 Szabolcs Szakacsits
  * Copyright (c) 2004-2006 Anton Altaparmakov
- * Copyright (c) 2010-2013 Jean-Pierre Andre
+ * Copyright (c) 2010-2014 Jean-Pierre Andre
  * Special image format support copyright (c) 2004 Per Olofsson
  *
  * Clone NTFS data and/or metadata to a sparse file, image, device or stdout.
@@ -388,7 +388,7 @@ static void version(void)
 		   "Efficiently clone, image, restore or rescue an NTFS Volume.\n\n"
 		   "Copyright (c) 2003-2006 Szabolcs Szakacsits\n"
 		   "Copyright (c) 2004-2006 Anton Altaparmakov\n"
-		   "Copyright (c) 2010-2013 Jean-Pierre Andre\n\n");
+		   "Copyright (c) 2010-2014 Jean-Pierre Andre\n\n");
 	fprintf(stderr, "%s\n%s%s", ntfs_gpl, ntfs_bugs, ntfs_home);
 	exit(1);
 }
@@ -2299,6 +2299,27 @@ static void set_filesize(s64 filesize)
 		}
 		exit(1);
 	}
+		/*
+		 * If truncate just created a sparse file, the ability
+		 * to generically store big files has been checked, but no
+		 * space has been reserved and available space has probably
+		 * not been checked. Better reset the file so that we write
+		 * sequentially to the end.
+		 */
+	if (!opt.no_action) {
+#ifdef HAVE_WINDOWS_H
+		if (ftruncate(fd_out, 0))
+			Printf("Failed to reset the output file.\n");
+#else
+		struct stat st;
+		int s;
+
+		s = fstat(fd_out, &st);
+		if (s || (!st.st_blocks && ftruncate(fd_out, 0)))
+			Printf("Failed to reset the output file.\n");
+#endif
+			/* Proceed even if ftruncate failed */
+	}
 }
 
 static s64 open_image(void)