The attached patch implements a symlink for win32 using junctions, and

uses that for win32 tablespaces.

Andreas Pflug

diff --git a/src/include/port.h b/src/include/port.h
index 731ec4120a41d2191feb5794814b67865086f784..10387b6201636e188f5901c5dd9ccdd91bedf876 100644 (file)
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/port.h,v 1.47 2004/08/01 06:56:39 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/port.h,v 1.48 2004/08/07 21:48:09 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -80,7 +80,7 @@ extern void set_pglocale_pgservice(const char *argv0, const char *app);
 extern int find_my_exec(const char *argv0, char *retpath);
 extern int find_other_exec(const char *argv0, const char *target,
                           const char *versionstr, char *retpath);
-#if defined(__CYGWIN__) || defined(WIN32)
+#if defined(WIN32) || defined(__CYGWIN__)
 #define EXE ".exe"
 #define DEVNULL "nul"
 #else
@@ -140,14 +140,17 @@ extern int pgkill(int pid, int sig);
 
 extern int pclose_check(FILE *stream);
 
-#if defined(__MINGW32__) || defined(__CYGWIN__)
+#if defined(WIN32) || defined(__CYGWIN__)
 /*
- * Win32 doesn't have reliable rename/unlink during concurrent access
+ * Win32 doesn't have reliable rename/unlink during concurrent access,
+ * and we need special code to do symlinks.
  */
 extern int pgrename(const char *from, const char *to);
 extern int pgunlink(const char *path);
-#define rename(from, to)   pgrename(from, to)
-#define unlink(path)       pgunlink(path)
+extern int pgsymlink(const char *oldpath, const char *newpath);
+#define rename(from, to)       pgrename(from, to)
+#define unlink(path)           pgunlink(path)
+#define symlink(oldpath, newpath)  pgsymlink(oldpath, newpath)
 #endif
 
 extern bool rmtree(char *path, bool rmtopdir);

diff --git a/src/port/dirmod.c b/src/port/dirmod.c
index 912a0c1ca8e13b6c0a20effde3ba9165a88322d6..3010127c4c2215dfc2e4cdbd621550f2ca948f47 100644 (file)
--- a/src/port/dirmod.c
+++ b/src/port/dirmod.c
@@ -10,7 +10,7 @@
  * Win32 (NT, Win2k, XP).  replace() doesn't work on Win95/98/Me.
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/port/dirmod.c,v 1.13 2004/08/01 06:19:26 momjian Exp $
+ *   $PostgreSQL: pgsql/src/port/dirmod.c,v 1.14 2004/08/07 21:48:09 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -33,10 +33,14 @@
 
 
 #include "miscadmin.h"
+#include 
 
 #undef rename
 #undef unlink
 
+/*
+ * pgrename
+ */
 int
 pgrename(const char *from, const char *to)
 {
@@ -79,6 +83,9 @@ pgrename(const char *from, const char *to)
 }
 
 
+/*
+ * pgunlink
+ */
 int
 pgunlink(const char *path)
 {
@@ -110,12 +117,119 @@ pgunlink(const char *path)
    return 0;
 }
 
+
+/*
+ * pgsymlink support:
+ *
+ * This struct is a replacement for REPARSE_DATA_BUFFER which is defined in VC6 winnt.h
+ * but omitted in later SDK functions.
+ * We only need the SymbolicLinkReparseBuffer part of the original struct's union.
+ */
+typedef struct
+{
+    DWORD  ReparseTag;
+    WORD   ReparseDataLength;
+    WORD   Reserved;
+    /* SymbolicLinkReparseBuffer */
+        WORD   SubstituteNameOffset;
+        WORD   SubstituteNameLength;
+        WORD   PrintNameOffset;
+        WORD   PrintNameLength;
+        WCHAR PathBuffer[1];
+}
+REPARSE_JUNCTION_DATA_BUFFER;
+
+#define REPARSE_JUNCTION_DATA_BUFFER_HEADER_SIZE   \
+       FIELD_OFFSET(REPARSE_JUNCTION_DATA_BUFFER, SubstituteNameOffset)
+
+
+/*
+ * pgsymlink - uses Win32 junction points
+ *
+ * For reference:  http://www.codeproject.com/w2k/junctionpoints.asp
+ */
+int
+pgsymlink(const char *oldpath, const char *newpath)
+{
+   HANDLE dirhandle;
+   DWORD len;
+   char *p = nativeTarget;
+   char buffer[MAX_PATH*sizeof(WCHAR) + sizeof(REPARSE_JUNCTION_DATA_BUFFER)];
+   char nativeTarget[MAX_PATH];
+   REPARSE_JUNCTION_DATA_BUFFER *reparseBuf = (REPARSE_JUNCTION_DATA_BUFFER*)buffer;
+    
+   CreateDirectory(newpath, 0);
+   dirhandle = CreateFile(newpath, GENERIC_READ | GENERIC_WRITE, 
+           0, 0, OPEN_EXISTING, 
+           FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, 0);
+    
+   if (dirhandle == INVALID_HANDLE_VALUE)
+       return -1;
+    
+   /* make sure we have an unparsed native win32 path */
+   if (memcmp("\\??\\", oldpath, 4))
+       sprintf(nativeTarget, "\\??\\%s", oldpath);
+   else
+       strcpy(nativeTarget, oldpath);
+    
+   while ((p = strchr(p, '/')) != 0)
+       *p++ = '\\';
+
+   len = strlen(nativeTarget) * sizeof(WCHAR);
+   reparseBuf->ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
+   reparseBuf->ReparseDataLength = len + 12;
+   reparseBuf->Reserved = 0;
+   reparseBuf->SubstituteNameOffset = 0;
+   reparseBuf->SubstituteNameLength = len;
+   reparseBuf->PrintNameOffset = len+sizeof(WCHAR);
+   reparseBuf->PrintNameLength = 0;
+   MultiByteToWideChar(CP_ACP, 0, nativeTarget, -1,
+                       reparseBuf->PathBuffer, MAX_PATH);
+    
+   /*
+    * FSCTL_SET_REPARSE_POINT is coded differently depending on SDK version;
+    * we use our own definition
+    */
+   if (!DeviceIoControl(dirhandle, 
+       CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 41, METHOD_BUFFERED, FILE_ANY_ACCESS),
+       reparseBuf, 
+       reparseBuf->ReparseDataLength + REPARSE_JUNCTION_DATA_BUFFER_HEADER_SIZE,
+       0, 0, &len, 0))
+   {
+       LPSTR msg;
+
+       errno=0;
+       FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
+                     NULL, GetLastError(), 
+                     MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                     (LPSTR)&msg, 0, NULL );
+       ereport(ERROR, (errcode_for_file_access(),
+           errmsg("Error setting junction for %s: %s", nativeTarget, msg)));
+       
+       LocalFree(msg);
+       
+       CloseHandle(dirhandle);
+       RemoveDirectory(newpath);
+       return -1;
+   }
+
+   CloseHandle(dirhandle);
+
+   return 0;
+}
+
 #endif
 
+
+/* ----------------
+ * rmtree routines
+ * ----------------
+ */
+
+
+/* We undefined these above, so we redefine them */
 #if defined(WIN32) || defined(__CYGWIN__)
-#define rmt_unlink(path) pgunlink(path)
-#else
-#define rmt_unlink(path) unlink(path)
+#define unlink(path)   pgunlink(path)
 #endif
 
 #ifdef FRONTEND
@@ -175,16 +289,15 @@ rmt_cleanup(char ** filenames)
    xfree(filenames);
 }
 
-
-
 /*
- * delete a directory tree recursively
- * assumes path points to a valid directory
- * deletes everything under path
- * if rmtopdir is true deletes the directory too
+ * rmtree
+ *
+ * Delete a directory tree recursively.
+ * Assumes path points to a valid directory.
+ * Deletes everything under path.
+ * If rmtopdir is true deletes the directory too.
  *
  */
-
 bool
 rmtree(char *path, bool rmtopdir)
 {
@@ -249,7 +362,7 @@ rmtree(char *path, bool rmtopdir)
        }
        else
        {
-           if (rmt_unlink(filepath) != 0)
+           if (unlink(filepath) != 0)
            {
                rmt_cleanup(filenames);
                return false;