3 files changed, 34 insertions, 2 deletions
diff --git a/src/Common/Format.c b/src/Common/Format.c
index 82c4df55..4aaf8b32 100644
--- a/src/Common/Format.c
+++ b/src/Common/Format.c
@@ -369,8 +369,13 @@ begin_format:
 		if (!volParams->hiddenVol && !bInstantRetryOtherFilesys)
 		{
 			LARGE_INTEGER volumeSize;
+			BOOL speedupFileCreation = FALSE;
 			volumeSize.QuadPart = dataAreaSize + TC_VOLUME_HEADER_GROUP_SIZE;
 
+			// speedup for file creation only makes sens when using quick format
+			if (volParams->quickFormat && volParams->fastCreateFile)
+				speedupFileCreation = TRUE;
+
 			if (volParams->sparseFileSwitch && volParams->quickFormat)
 			{
 				// Create as sparse file container
@@ -384,12 +389,28 @@ begin_format:
 
 			// Preallocate the file
 			if (!SetFilePointerEx (dev, volumeSize, NULL, FILE_BEGIN)
-				|| !SetEndOfFile (dev)
-				|| SetFilePointer (dev, 0, NULL, FILE_BEGIN) != 0)
+				|| !SetEndOfFile (dev))
+			{
+				nStatus = ERR_OS_ERROR;
+				goto error;
+			}
+
+			if (speedupFileCreation)
+			{
+				// accelerate file creation by telling Windows not to fill all file content with zeros
+				// this has security issues since it will put existing disk content into file container
+				// We use this mechanism only when switch /fastCreateFile specific and when quick format
+				// also specified and which is documented to have security issues.
+				// we don't check returned status because failure is not issue for us
+				SetFileValidData (dev, volumeSize.QuadPart);
+			}
+
+			if (SetFilePointer (dev, 0, NULL, FILE_BEGIN) != 0)
 			{
 				nStatus = ERR_OS_ERROR;
 				goto error;
 			}
+
 		}
 	}
 
diff --git a/src/Common/Format.h b/src/Common/Format.h
index 961ece7c..4ce1b8c7 100644
--- a/src/Common/Format.h
+++ b/src/Common/Format.h
@@ -38,6 +38,7 @@ typedef struct
 	unsigned int clusterSize;
 	BOOL sparseFileSwitch;
 	BOOL quickFormat;
+	BOOL fastCreateFile;
 	DWORD sectorSize;
 	int *realClusterSize;
 	Password *password;
diff --git a/src/Format/Tcformat.c b/src/Format/Tcformat.c
index 013e27ca..002b6c5c 100644
--- a/src/Format/Tcformat.c
+++ b/src/Format/Tcformat.c
@@ -250,6 +250,7 @@ int CmdVolumeFilesystem = FILESYS_NONE;
 unsigned __int64 CmdVolumeFileSize = 0;
 BOOL CmdSparseFileSwitch = FALSE;
 BOOL CmdQuickFormat = FALSE;
+BOOL CmdFastCreateFile = FALSE;
 
 BOOL bForceOperation = FALSE;
 
@@ -282,6 +283,7 @@ BOOL bDisplayPoolContents = TRUE;
 
 volatile BOOL bSparseFileSwitch = FALSE;
 volatile BOOL quickFormat = FALSE;
+volatile BOOL fastCreateFile = FALSE;
 volatile BOOL dynamicFormat = FALSE; /* this variable represents the sparse file flag. */
 volatile int fileSystem = FILESYS_NONE;
 volatile int clusterSize = 0;
@@ -2635,6 +2637,7 @@ static void __cdecl volTransformThreadFunction (void *hwndDlgArg)
 	volParams->clusterSize = clusterSize;
 	volParams->sparseFileSwitch = dynamicFormat;
 	volParams->quickFormat = quickFormat;
+	volParams->fastCreateFile = fastCreateFile;
 	volParams->sectorSize = GetFormatSectorSize();
 	volParams->realClusterSize = &realClusterSize;
 	volParams->password = &volumePassword;
@@ -6234,6 +6237,7 @@ BOOL CALLBACK MainDialogProc (HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPa
 				}
 
 				quickFormat = CmdQuickFormat;
+				fastCreateFile = CmdFastCreateFile;
 				dynamicFormat = CmdSparseFileSwitch;
 
 				if (!GetDiskFreeSpaceEx (root, &free, 0, 0))
@@ -8994,6 +8998,7 @@ void ExtractCommandLine (HWND hwndDlg, wchar_t *lpszCommandLine)
 				OptionForce,
 				OptionNoSizeCheck,
 				OptionQuickFormat,
+				OptionFastCreateFile,
 			};
 
 			argument args[]=
@@ -9016,6 +9021,7 @@ void ExtractCommandLine (HWND hwndDlg, wchar_t *lpszCommandLine)
 				{ OptionForce,					L"/force",			NULL, FALSE },
 				{ OptionNoSizeCheck,			L"/nosizecheck",	NULL, FALSE },
 				{ OptionQuickFormat,			L"/quick",	NULL, FALSE },
+				{ OptionFastCreateFile,			L"/fastcreatefile",	NULL, FALSE },
 
 				// Internal
 				{ CommandResumeSysEncLogOn,		L"/acsysenc",		L"/a", TRUE },
@@ -9372,6 +9378,10 @@ void ExtractCommandLine (HWND hwndDlg, wchar_t *lpszCommandLine)
 				CmdQuickFormat = TRUE;
 				break;
 
+			case OptionFastCreateFile:
+				CmdFastCreateFile = TRUE;
+				break;
+
 			case OptionHistory:
 				{
 					wchar_t szTmp[8] = {0};