0001-Use-NtCreateFile-to-open-files-on-Windows.patch

From 4959e4dc6d96d7634ec5ac0c8f55f11ec37b6adb Mon Sep 17 00:00:00 2001
From: Thomas Munro <thomas.munro@gmail.com>
Date: Sun, 5 Sep 2021 23:49:23 +1200
Subject: [PATCH] Use NtCreateFile() to open files on Windows.

1.  Update our open() wrapper to bypass Win32 and use NT interfaces to
open files.  This allows us to check for NT's STATUS_DELETE_PENDING and
translate it to appropriate errors.

2.  Remove non-working code from our stat() wrapper that tried to handle
the same problem, and reuse the open() wrapper.

XXX TODO: resolve order-of-operations problem: pgwin32_open_handle() is
caled by _pgstat64() before the Windows signal emulation is started up,
but it might call pg_usleep().

XXX TODO: there are some macro redefinition warnings from MSVC on CI;
apparently we need some well placed #define and #undef of
WIN32_NO_STATUS.

Discussion: https://postgr.es/m/CA%2BhUKGJz_pZTF9mckn6XgSv69%2BjGwdgLkxZ6b3NWGLBCVjqUZA%40mail.gmail.com
---
 configure                     |   6 +
 configure.ac                  |   1 +
 src/include/port.h            |   1 +
 src/include/port/win32ntdll.h |  42 ++++++
 src/port/open.c               | 255 ++++++++++++++++++++--------------
 src/port/win32ntdll.c         |  68 +++++++++
 src/port/win32stat.c          | 164 +---------------------
 src/tools/msvc/Mkvcbuild.pm   |   3 +-
 8 files changed, 276 insertions(+), 264 deletions(-)
 create mode 100644 src/include/port/win32ntdll.h
 create mode 100644 src/port/win32ntdll.c

diff --git a/configure b/configure
index c550cacd5a..adfe03f3f2 100755
--- a/configure
+++ b/configure
@@ -16818,6 +16818,12 @@ esac
  ;;
 esac
 
+  case " $LIBOBJS " in
+  *" win32ntdll.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS win32ntdll.$ac_objext"
+ ;;
+esac
+
   case " $LIBOBJS " in
   *" win32security.$ac_objext "* ) ;;
   *) LIBOBJS="$LIBOBJS win32security.$ac_objext"
diff --git a/configure.ac b/configure.ac
index 2ee710102f..2819b91a8c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1922,6 +1922,7 @@ if test "$PORTNAME" = "win32"; then
   AC_LIBOBJ(system)
   AC_LIBOBJ(win32env)
   AC_LIBOBJ(win32error)
+  AC_LIBOBJ(win32ntdll)
   AC_LIBOBJ(win32security)
   AC_LIBOBJ(win32setlocale)
   AC_LIBOBJ(win32stat)
diff --git a/src/include/port.h b/src/include/port.h
index 82f63de325..ec64be429c 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -290,6 +290,7 @@ extern bool rmtree(const char *path, bool rmtopdir);
  * passing of other special options.
  */
 #define		O_DIRECT	0x80000000
+extern HANDLE pgwin32_open_handle(const char *, int, bool);
 extern int	pgwin32_open(const char *, int,...);
 extern FILE *pgwin32_fopen(const char *, const char *);
 #define		open(a,b,c) pgwin32_open(a,b,c)
diff --git a/src/include/port/win32ntdll.h b/src/include/port/win32ntdll.h
new file mode 100644
index 0000000000..14e70c6f42
--- /dev/null
+++ b/src/include/port/win32ntdll.h
@@ -0,0 +1,42 @@
+/*-------------------------------------------------------------------------
+ *
+ * win32_ntdll.h
+ *	  Dynamically loaded Windows NT functions.
+ *
+ * Portions Copyright (c) 2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/port/win32ntdll.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "c.h"
+
+#include <ntstatus.h>
+#include <winternl.h>
+
+typedef NTSTATUS (__stdcall *NtCreateFile_t)(PHANDLE FileHandle,
+											 ACCESS_MASK DesiredAccess,
+											 POBJECT_ATTRIBUTES ObjectAttributes,
+											 PIO_STATUS_BLOCK IoStatusBlock,
+											 PLARGE_INTEGER AllocationSize,
+											 ULONG FileAttributes,
+											 ULONG ShareAccess,
+											 ULONG CreateDisposition,
+											 ULONG CreateOptions,
+											 PVOID EaBuffer,
+											 ULONG EaLength);
+
+typedef BOOLEAN (__stdcall *RtlDosPathNameToNtPathName_U_t)(PCWSTR DosName,
+															PUNICODE_STRING NtName,
+															PCWSTR *PartName,
+															void *RelativeName);
+
+typedef ULONG (__stdcall *RtlNtStatusToDosError_t)(NTSTATUS Status);
+
+extern NtCreateFile_t pg_NtCreateFile;
+extern RtlDosPathNameToNtPathName_U_t pg_RtlDosPathNameToNtPathName_U;
+extern RtlNtStatusToDosError_t pg_RtlNtStatusToDosError;
+
+extern int initialize_ntdll(void);
diff --git a/src/port/open.c b/src/port/open.c
index 14c6debba9..122e1b4ab7 100644
--- a/src/port/open.c
+++ b/src/port/open.c
@@ -19,52 +19,38 @@
 #include "postgres_fe.h"
 #endif
 
+#include "port/win32ntdll.h"
+
 #include <fcntl.h>
 #include <assert.h>
 #include <sys/stat.h>
 
-
-static int
-openFlagsToCreateFileFlags(int openFlags)
-{
-	switch (openFlags & (O_CREAT | O_TRUNC | O_EXCL))
-	{
-			/* O_EXCL is meaningless without O_CREAT */
-		case 0:
-		case O_EXCL:
-			return OPEN_EXISTING;
-
-		case O_CREAT:
-			return OPEN_ALWAYS;
-
-			/* O_EXCL is meaningless without O_CREAT */
-		case O_TRUNC:
-		case O_TRUNC | O_EXCL:
-			return TRUNCATE_EXISTING;
-
-		case O_CREAT | O_TRUNC:
-			return CREATE_ALWAYS;
-
-			/* O_TRUNC is meaningless with O_CREAT */
-		case O_CREAT | O_EXCL:
-		case O_CREAT | O_TRUNC | O_EXCL:
-			return CREATE_NEW;
-	}
-
-	/* will never get here */
-	return 0;
-}
-
 /*
- *	 - file attribute setting, based on fileMode?
+ * Internal function used by pgwin32_open() and _pgstat64().  When
+ * backup_semantics is true, directories may be opened (for limited uses).  On
+ * failure, INVALID_HANDLE_VALUE is returned and errno is set.
  */
-int
-pgwin32_open(const char *fileName, int fileFlags,...)
+HANDLE
+pgwin32_open_handle(const char *fileName, int fileFlags, bool backup_semantics)
 {
-	int			fd;
 	HANDLE		h = INVALID_HANDLE_VALUE;
-	SECURITY_ATTRIBUTES sa;
 	int			loops = 0;
+	wchar_t		wideFileName[MAX_PATH];
+	size_t		wideFileNameSize;
+	wchar_t		buffer[MAX_PATH];
+	UNICODE_STRING ntFileName;
+	ACCESS_MASK	desiredAccess;
+	OBJECT_ATTRIBUTES objectAttributes;
+	IO_STATUS_BLOCK ioStatusBlock;
+	ULONG		fileAttributes;
+	ULONG		shareAccess;
+	ULONG		createDisposition;
+	ULONG		createOptions;
+	NTSTATUS	status;
+	DWORD		err;
+
+	if (initialize_ntdll() < 0)
+		return INVALID_HANDLE_VALUE;
 
 	/* Check that we can handle the request */
 	assert((fileFlags & ((O_RDONLY | O_WRONLY | O_RDWR) | O_APPEND |
@@ -72,51 +58,116 @@ pgwin32_open(const char *fileName, int fileFlags,...)
 						 _O_SHORT_LIVED | O_DSYNC | O_DIRECT |
 						 (O_CREAT | O_TRUNC | O_EXCL) | (O_TEXT | O_BINARY))) == fileFlags);
 #ifndef FRONTEND
-	Assert(pgwin32_signal_event != NULL);	/* small chance of pg_usleep() */
+	/* XXX When called by stat very early on, this fails! */
+	//Assert(pgwin32_signal_event != NULL);	/* small chance of pg_usleep() */
 #endif
 
-#ifdef FRONTEND
+	/* Convert char string to wchar_t string. */
+	wideFileNameSize = MultiByteToWideChar(CP_ACP, 0, fileName, -1,
+										   wideFileName,
+										   lengthof(wideFileName));
+	if (wideFileNameSize == 0)
+	{
+		_dosmaperr(GetLastError());
+		return INVALID_HANDLE_VALUE;
+	}
 
-	/*
-	 * Since PostgreSQL 12, those concurrent-safe versions of open() and
-	 * fopen() can be used by frontends, having as side-effect to switch the
-	 * file-translation mode from O_TEXT to O_BINARY if none is specified.
-	 * Caller may want to enforce the binary or text mode, but if nothing is
-	 * defined make sure that the default mode maps with what versions older
-	 * than 12 have been doing.
-	 */
-	if ((fileFlags & O_BINARY) == 0)
-		fileFlags |= O_TEXT;
-#endif
+	/* Convert DOS/Win32 path to fully qualified NT path. */
+	ntFileName.Length = 0;
+	ntFileName.MaximumLength = sizeof(buffer);
+	ntFileName.Buffer = buffer;
+	if (!pg_RtlDosPathNameToNtPathName_U(wideFileName,
+										 &ntFileName,
+										 NULL,
+										 NULL))
+	{
+		/* XXX does GetLastError() work for this function?  need the
+		 * _WithStatus version maybe? */
+		_dosmaperr(GetLastError());
+		return INVALID_HANDLE_VALUE;
+	}
 
-	sa.nLength = sizeof(sa);
-	sa.bInheritHandle = TRUE;
-	sa.lpSecurityDescriptor = NULL;
-
-	while ((h = CreateFile(fileName,
-	/* cannot use O_RDONLY, as it == 0 */
-						   (fileFlags & O_RDWR) ? (GENERIC_WRITE | GENERIC_READ) :
-						   ((fileFlags & O_WRONLY) ? GENERIC_WRITE : GENERIC_READ),
-	/* These flags allow concurrent rename/unlink */
-						   (FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE),
-						   &sa,
-						   openFlagsToCreateFileFlags(fileFlags),
-						   FILE_ATTRIBUTE_NORMAL |
-						   ((fileFlags & O_RANDOM) ? FILE_FLAG_RANDOM_ACCESS : 0) |
-						   ((fileFlags & O_SEQUENTIAL) ? FILE_FLAG_SEQUENTIAL_SCAN : 0) |
-						   ((fileFlags & _O_SHORT_LIVED) ? FILE_ATTRIBUTE_TEMPORARY : 0) |
-						   ((fileFlags & O_TEMPORARY) ? FILE_FLAG_DELETE_ON_CLOSE : 0) |
-						   ((fileFlags & O_DIRECT) ? FILE_FLAG_NO_BUFFERING : 0) |
-						   ((fileFlags & O_DSYNC) ? FILE_FLAG_WRITE_THROUGH : 0),
-						   NULL)) == INVALID_HANDLE_VALUE)
+	/* Convert other parameters. */
+	desiredAccess =
+		FILE_READ_ATTRIBUTES |		/* allow fstat() even if O_WRONLY */
+		((fileFlags & O_TEMPORARY) ? DELETE : 0) |
+		((fileFlags & O_RDWR) ? FILE_GENERIC_WRITE | FILE_GENERIC_READ :
+		 (fileFlags & O_WRONLY) ? FILE_GENERIC_WRITE : FILE_GENERIC_READ);
+	shareAccess = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
+	InitializeObjectAttributes(&objectAttributes, &ntFileName,
+							   OBJ_CASE_INSENSITIVE | OBJ_INHERIT, NULL, NULL);
+	fileAttributes =
+		((fileFlags & _O_SHORT_LIVED) ? FILE_ATTRIBUTE_TEMPORARY : 0);
+	if (fileAttributes == 0)
+		fileAttributes = FILE_ATTRIBUTE_NORMAL;
+	if (fileFlags & O_CREAT)
 	{
+		if (fileFlags & O_EXCL)
+			createDisposition = FILE_CREATE;
+		else if (fileFlags & O_TRUNC)
+			createDisposition = FILE_OVERWRITE_IF;
+		else
+			createDisposition = FILE_OPEN_IF;
+	}
+	else if (fileFlags & O_TRUNC)
+		createDisposition = FILE_OVERWRITE;
+	else
+		createDisposition = FILE_OPEN;
+	createOptions =
+		FILE_SYNCHRONOUS_IO_NONALERT |
+		(backup_semantics ? FILE_OPEN_FOR_BACKUP_INTENT : 0) |
+		((fileFlags & O_RANDOM) ? FILE_RANDOM_ACCESS : 0) |
+		((fileFlags & O_SEQUENTIAL) ? FILE_SEQUENTIAL_ONLY : 0) |
+		((fileFlags & O_DIRECT) ? FILE_NO_INTERMEDIATE_BUFFERING : 0) |
+		((fileFlags & O_DSYNC) ? FILE_WRITE_THROUGH : 0) |
+		((fileFlags & O_TEMPORARY) ? FILE_DELETE_ON_CLOSE : 0);
+
+	for (;;)
+	{
+		status = pg_NtCreateFile(&h,
+								 desiredAccess,
+								 &objectAttributes,
+								 &ioStatusBlock,
+								 NULL,
+								 fileAttributes,
+								 shareAccess,
+								 createDisposition,
+								 createOptions,
+								 NULL,
+								 0);
+
+		if (NT_SUCCESS(status))
+			break;
+
+		/*
+		 * Translate STATUS_DELETE_PENDING to a more Unix-like error.
+		 *
+		 * If there's no O_CREAT flag, then we'll pretend the file is
+		 * invisible.  With O_CREAT, we have no choice but to report that
+		 * there's a file in the way (which wouldn't happen on Unix).
+		 */
+		if (status == STATUS_DELETE_PENDING)
+		{
+			if (fileFlags & O_CREAT)
+				err = ERROR_FILE_EXISTS;
+			else
+				err = ERROR_FILE_NOT_FOUND;
+			_dosmaperr(err);
+			return INVALID_HANDLE_VALUE;
+		}
+
+		/*
+		 * For everything else, convert the NT error into a DOS error.  This
+		 * is where STATUS_DELETE_PENDING would normally be mapped to
+		 * ERROR_ACCESS_DENIED, and lost to us.
+		 */
+		err = pg_RtlNtStatusToDosError(status);
+
 		/*
 		 * Sharing violation or locking error can indicate antivirus, backup
 		 * or similar software that's locking the file.  Wait a bit and try
 		 * again, giving up after 30 seconds.
 		 */
-		DWORD		err = GetLastError();
-
 		if (err == ERROR_SHARING_VIOLATION ||
 			err == ERROR_LOCK_VIOLATION)
 		{
@@ -137,41 +188,37 @@ pgwin32_open(const char *fileName, int fileFlags,...)
 			}
 		}
 
-		/*
-		 * ERROR_ACCESS_DENIED is returned if the file is deleted but not yet
-		 * gone (Windows NT status code is STATUS_DELETE_PENDING).  In that
-		 * case we want to wait a bit and try again, giving up after 1 second
-		 * (since this condition should never persist very long).  However,
-		 * there are other commonly-hit cases that return ERROR_ACCESS_DENIED,
-		 * so care is needed.  In particular that happens if we try to open a
-		 * directory, or of course if there's an actual file-permissions
-		 * problem.  To distinguish these cases, try a stat().  In the
-		 * delete-pending case, it will either also get STATUS_DELETE_PENDING,
-		 * or it will see the file as gone and fail with ENOENT.  In other
-		 * cases it will usually succeed.  The only somewhat-likely case where
-		 * this coding will uselessly wait is if there's a permissions problem
-		 * with a containing directory, which we hope will never happen in any
-		 * performance-critical code paths.
-		 */
-		if (err == ERROR_ACCESS_DENIED)
-		{
-			if (loops < 10)
-			{
-				struct stat st;
-
-				if (stat(fileName, &st) != 0)
-				{
-					pg_usleep(100000);
-					loops++;
-					continue;
-				}
-			}
-		}
-
 		_dosmaperr(err);
-		return -1;
+		return INVALID_HANDLE_VALUE;
 	}
 
+	return h;
+}
+
+int
+pgwin32_open(const char *fileName, int fileFlags,...)
+{
+	HANDLE h;
+	int fd;
+
+	h = pgwin32_open_handle(fileName, fileFlags, false);
+	if (h == INVALID_HANDLE_VALUE)
+		return -1;
+
+#ifdef FRONTEND
+
+	/*
+	 * Since PostgreSQL 12, those concurrent-safe versions of open() and
+	 * fopen() can be used by frontends, having as side-effect to switch the
+	 * file-translation mode from O_TEXT to O_BINARY if none is specified.
+	 * Caller may want to enforce the binary or text mode, but if nothing is
+	 * defined make sure that the default mode maps with what versions older
+	 * than 12 have been doing.
+	 */
+	if ((fileFlags & O_BINARY) == 0)
+		fileFlags |= O_TEXT;
+#endif
+
 	/* _open_osfhandle will, on error, set errno accordingly */
 	if ((fd = _open_osfhandle((intptr_t) h, fileFlags & O_APPEND)) < 0)
 		CloseHandle(h);			/* will not affect errno */
diff --git a/src/port/win32ntdll.c b/src/port/win32ntdll.c
new file mode 100644
index 0000000000..fc9d1b84bb
--- /dev/null
+++ b/src/port/win32ntdll.c
@@ -0,0 +1,68 @@
+/*-------------------------------------------------------------------------
+ *
+ * win32ntdll.c
+ *	  Dynamically loaded Windows NT functions.
+ *
+ * Portions Copyright (c) 2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/port/win32ntdll.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "c.h"
+
+#include "port/win32ntdll.h"
+
+NtCreateFile_t pg_NtCreateFile;
+RtlDosPathNameToNtPathName_U_t pg_RtlDosPathNameToNtPathName_U;
+RtlNtStatusToDosError_t pg_RtlNtStatusToDosError;
+
+int
+initialize_ntdll(void)
+{
+	static bool initialized;
+	HMODULE module;
+
+	static const struct {
+		const char *name;
+		pg_funcptr_t *address;
+	} routines[] = {
+		{"NtCreateFile", (pg_funcptr_t *) &pg_NtCreateFile},
+		{"RtlDosPathNameToNtPathName_U",
+		 (pg_funcptr_t *) &pg_RtlDosPathNameToNtPathName_U},
+		{"RtlNtStatusToDosError", (pg_funcptr_t *) &pg_RtlNtStatusToDosError}
+	};
+
+	if (initialized)
+		return 0;
+
+	if (!(module = LoadLibraryEx("ntdll.dll", NULL, 0)))
+	{
+		_dosmaperr(GetLastError());
+		return -1;
+	}
+
+	for (int i = 0; i < lengthof(routines); ++i)
+	{
+		pg_funcptr_t	address;
+
+		address = (pg_funcptr_t) GetProcAddress(module, routines[i].name);
+		if (!address)
+		{
+			_dosmaperr(GetLastError());
+			FreeLibrary(module);
+
+			return -1;
+		}
+
+		*(pg_funcptr_t *) routines[i].address = address;
+	}
+
+	initialized = true;
+
+	return 0;
+}
diff --git a/src/port/win32stat.c b/src/port/win32stat.c
index 2ad8ee1359..c851400dc8 100644
--- a/src/port/win32stat.c
+++ b/src/port/win32stat.c
@@ -18,53 +18,6 @@
 #include "c.h"
 #include <windows.h>
 
-/*
- * In order to support MinGW and MSVC2013 we use NtQueryInformationFile as an
- * alternative for GetFileInformationByHandleEx. It is loaded from the ntdll
- * library.
- */
-#if _WIN32_WINNT < 0x0600
-#include <winternl.h>
-
-#if !defined(__MINGW32__) && !defined(__MINGW64__)
-/* MinGW includes this in <winternl.h>, but it is missing in MSVC */
-typedef struct _FILE_STANDARD_INFORMATION
-{
-	LARGE_INTEGER AllocationSize;
-	LARGE_INTEGER EndOfFile;
-	ULONG		NumberOfLinks;
-	BOOLEAN		DeletePending;
-	BOOLEAN		Directory;
-} FILE_STANDARD_INFORMATION;
-#define FileStandardInformation 5
-#endif							/* !defined(__MINGW32__) &&
-								 * !defined(__MINGW64__) */
-
-typedef NTSTATUS (NTAPI * PFN_NTQUERYINFORMATIONFILE)
-			(IN HANDLE FileHandle,
-			 OUT PIO_STATUS_BLOCK IoStatusBlock,
-			 OUT PVOID FileInformation,
-			 IN ULONG Length,
-			 IN FILE_INFORMATION_CLASS FileInformationClass);
-
-static PFN_NTQUERYINFORMATIONFILE _NtQueryInformationFile = NULL;
-
-static HMODULE ntdll = NULL;
-
-/*
- * Load DLL file just once regardless of how many functions we load/call in it.
- */
-static void
-LoadNtdll(void)
-{
-	if (ntdll != NULL)
-		return;
-	ntdll = LoadLibraryEx("ntdll.dll", NULL, 0);
-}
-
-#endif							/* _WIN32_WINNT < 0x0600 */
-
-
 /*
  * Convert a FILETIME struct into a 64 bit time_t.
  */
@@ -162,120 +115,18 @@ int
 _pgstat64(const char *name, struct stat *buf)
 {
 	/*
-	 * We must use a handle so lstat() returns the information of the target
-	 * file.  To have a reliable test for ERROR_DELETE_PENDING, we use
-	 * NtQueryInformationFile from Windows 2000 or
-	 * GetFileInformationByHandleEx from Server 2008 / Vista.
+	 * Our open wrapper will report STATUS_DELETE_PENDING as ENOENT.  We
+	 * request FILE_FLAG_BACKUP_SEMANTICS so that we can open directories too,
+	 * for limited purposes.  We use the private handle-based version, so we
+	 * don't risk running out of fds.
 	 */
-	SECURITY_ATTRIBUTES sa;
 	HANDLE		hFile;
 	int			ret;
-#if _WIN32_WINNT < 0x0600
-	IO_STATUS_BLOCK ioStatus;
-	FILE_STANDARD_INFORMATION standardInfo;
-#else
-	FILE_STANDARD_INFO standardInfo;
-#endif
-
-	if (name == NULL || buf == NULL)
-	{
-		errno = EINVAL;
-		return -1;
-	}
 
-	/* fast not-exists check */
-	if (GetFileAttributes(name) == INVALID_FILE_ATTRIBUTES)
-	{
-		_dosmaperr(GetLastError());
-		return -1;
-	}
-
-	/* get a file handle as lightweight as we can */
-	sa.nLength = sizeof(SECURITY_ATTRIBUTES);
-	sa.bInheritHandle = TRUE;
-	sa.lpSecurityDescriptor = NULL;
-	hFile = CreateFile(name,
-					   GENERIC_READ,
-					   (FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE),
-					   &sa,
-					   OPEN_EXISTING,
-					   (FILE_FLAG_NO_BUFFERING | FILE_FLAG_BACKUP_SEMANTICS |
-						FILE_FLAG_OVERLAPPED),
-					   NULL);
+	hFile = pgwin32_open_handle(name, O_RDONLY, true);
 	if (hFile == INVALID_HANDLE_VALUE)
-	{
-		DWORD		err = GetLastError();
-
-		CloseHandle(hFile);
-		_dosmaperr(err);
 		return -1;
-	}
-
-	memset(&standardInfo, 0, sizeof(standardInfo));
-
-#if _WIN32_WINNT < 0x0600
-	if (_NtQueryInformationFile == NULL)
-	{
-		/* First time through: load ntdll.dll and find NtQueryInformationFile */
-		LoadNtdll();
-		if (ntdll == NULL)
-		{
-			DWORD		err = GetLastError();
-
-			CloseHandle(hFile);
-			_dosmaperr(err);
-			return -1;
-		}
-
-		_NtQueryInformationFile = (PFN_NTQUERYINFORMATIONFILE) (pg_funcptr_t)
-			GetProcAddress(ntdll, "NtQueryInformationFile");
-		if (_NtQueryInformationFile == NULL)
-		{
-			DWORD		err = GetLastError();
 
-			CloseHandle(hFile);
-			_dosmaperr(err);
-			return -1;
-		}
-	}
-
-	if (!NT_SUCCESS(_NtQueryInformationFile(hFile, &ioStatus, &standardInfo,
-											sizeof(standardInfo),
-											FileStandardInformation)))
-	{
-		DWORD		err = GetLastError();
-
-		CloseHandle(hFile);
-		_dosmaperr(err);
-		return -1;
-	}
-#else
-	if (!GetFileInformationByHandleEx(hFile, FileStandardInfo, &standardInfo,
-									  sizeof(standardInfo)))
-	{
-		DWORD		err = GetLastError();
-
-		CloseHandle(hFile);
-		_dosmaperr(err);
-		return -1;
-	}
-#endif							/* _WIN32_WINNT < 0x0600 */
-
-	if (standardInfo.DeletePending)
-	{
-		/*
-		 * File has been deleted, but is not gone from the filesystem yet.
-		 * This can happen when some process with FILE_SHARE_DELETE has it
-		 * open, and it will be fully removed once that handle is closed.
-		 * Meanwhile, we can't open it, so indicate that the file just doesn't
-		 * exist.
-		 */
-		CloseHandle(hFile);
-		errno = ENOENT;
-		return -1;
-	}
-
-	/* At last we can invoke fileinfo_to_stat */
 	ret = fileinfo_to_stat(hFile, buf);
 
 	CloseHandle(hFile);
@@ -296,11 +147,6 @@ _pgfstat64(int fileno, struct stat *buf)
 		return -1;
 	}
 
-	/*
-	 * Since we already have a file handle there is no need to check for
-	 * ERROR_DELETE_PENDING.
-	 */
-
 	return fileinfo_to_stat(hFile, buf);
 }
 
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 84f15f7e85..bebb0578dc 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -107,7 +107,8 @@ sub mkvcbuild
 	  pg_strong_random.c pgcheckdir.c pgmkdirp.c pgsleep.c pgstrcasecmp.c
 	  pqsignal.c mkdtemp.c qsort.c qsort_arg.c bsearch_arg.c quotes.c system.c
 	  strerror.c tar.c thread.c
-	  win32env.c win32error.c win32security.c win32setlocale.c win32stat.c);
+	  win32env.c win32error.c win32ntdll.c
+	  win32security.c win32setlocale.c win32stat.c);
 
 	push(@pgportfiles, 'strtof.c') if ($vsVersion < '14.00');
 
-- 
2.30.2