diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 3e89d7687..4a68aba60 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,11 @@
+2009-11-09  Corinna Vinschen  <corinna@vinschen.de>
+
+	* path.cc (symlink_info::check_reparse_point): Always check
+	SubstituteName for volume string to recognize volume mount points.
+	Reuse subst when calling sys_wcstombs.
+	* syscalls.cc (rename): Set errno to EBUSY when trying to rename
+	volume mount points.  Explain why.
+
 2009-11-09  Corinna Vinschen  <corinna@vinschen.de>
 
 	* fhandler_console.cc (fhandler_console::read): Restrict generating
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 1f95073b9..daf780e84 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -1873,18 +1873,15 @@ symlink_info::check_reparse_point (HANDLE h)
 		  (WCHAR *)((char *)rp->MountPointReparseBuffer.PathBuffer
 			  + rp->MountPointReparseBuffer.SubstituteNameOffset),
 		  rp->MountPointReparseBuffer.SubstituteNameLength);
-      if (rp->MountPointReparseBuffer.PrintNameLength == 0
-	  || RtlEqualUnicodePathPrefix (&subst, &ro_u_volume, TRUE))
+      if (RtlEqualUnicodePathPrefix (&subst, &ro_u_volume, TRUE))
 	{
 	  /* Volume mount point.  Not treated as symlink. The return
 	     value of -1 is a hint for the caller to treat this as a
 	     volume mount point. */
 	  return -1;
 	}
-      sys_wcstombs (srcbuf, SYMLINK_MAX + 1,
-		    (WCHAR *)((char *)rp->MountPointReparseBuffer.PathBuffer
-			    + rp->MountPointReparseBuffer.SubstituteNameOffset),
-		    rp->MountPointReparseBuffer.SubstituteNameLength / sizeof (WCHAR));
+      sys_wcstombs (srcbuf, SYMLINK_MAX + 1, subst.Buffer,
+		    subst.Length / sizeof (WCHAR));
       pflags = PATH_SYMLINK | PATH_REP;
       fileattr &= ~FILE_ATTRIBUTE_DIRECTORY;
     }
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 55415b631..7a4f239b8 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -1758,6 +1758,16 @@ rename (const char *oldpath, const char *newpath)
       set_errno (EROFS);
       goto out;
     }
+  if (oldpc.has_attribute (FILE_ATTRIBUTE_REPARSE_POINT) && !oldpc.issymlink ())
+    {
+      /* Volume mount point.  If we try to rename a volume mount point, NT
+	 returns STATUS_NOT_SAME_DEVICE ==> Win32 ERROR_NOT_SAME_DEVICE ==>
+	 errno EXDEV.  That's bad since mv(1) will now perform a cross-device
+	 move.  So what we do here is to treat the volume mount point just
+	 like Linux treats a mount point. */
+      set_errno (EBUSY);
+      goto out;
+    }
   if (old_dir_requested && !oldpc.isdir ())
     {
       /* Reject rename("file/","x").  */