Added base version of file system infrastructure. This includes a major

overhaul of the RTEMS system call interface.  This base file system is
the "In-Memory File System" aka IMFS.

The design and implementation was done by the following people:

  + Joel Sherrill (joel@OARcorp.com)
  + Jennifer Averett (jennifer@OARcorp.com)
  + Steve "Mr Mount" Salitasc (salitasc@OARcorp.com)
  + Kerwin Wade (wade@OARcorp.com)

PROBLEMS
========
  + It is VERY likely that merging this will break the UNIX port.  This
    can/will be fixed.

  + There is likely some reentrancy/mutual exclusion needed.

  + Eventually, there should be a "mini-IMFS" description table to
    eliminate links, symlinks, etc to save memory.  All you need to
    have "classic RTEMS" functionality is technically directories
    and device IO.  All the rest could be left out to save memory.

1 files changed, 60 insertions, 0 deletions

diff --git a/c/src/exec/libcsupport/src/ftruncate.c b/c/src/exec/libcsupport/src/ftruncate.c
new file mode 100644
index 0000000000..7fb2286531
--- /dev/null
+++ b/c/src/exec/libcsupport/src/ftruncate.c
@@ -0,0 +1,60 @@
+/*
+ *  ftruncate() - Truncate a File to the Specified Length
+ *
+ *  COPYRIGHT (c) 1989-1998.
+ *  On-Line Applications Research Corporation (OAR).
+ *  Copyright assigned to U.S. Government, 1994.
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.OARcorp.com/rtems/license.html.
+ *
+ *  $Id$
+ */
+
+#include <unistd.h>
+#include <errno.h>
+
+#include "libio_.h"
+
+int ftruncate(
+  int     fd,
+  off_t   length
+)
+{
+  rtems_libio_t                    *iop;
+  rtems_filesystem_location_info_t  loc;
+  
+  /*
+   *  If this is not a file system based entity, it is an error.
+   */
+
+  if ( rtems_file_descriptor_type( fd ) )
+    set_errno_and_return_minus_one( EBADF );
+
+  /*
+   *  Now process the ftruncate() request.
+   */
+  
+  iop = rtems_libio_iop( fd );
+
+  /*
+   *  Make sure we are not working on a directory
+   */
+
+  loc = iop->pathinfo;
+  if ( !loc.ops->node_type )
+    set_errno_and_return_minus_one( ENOTSUP );
+    
+  if ( (*loc.ops->node_type)( &loc ) == RTEMS_FILESYSTEM_DIRECTORY )
+    set_errno_and_return_minus_one( EISDIR );
+
+  rtems_libio_check_fd( fd );
+  rtems_libio_check_permissions( iop, LIBIO_FLAGS_WRITE );
+
+  if ( !iop->handlers->ftruncate )
+    set_errno_and_return_minus_one( ENOTSUP );
+
+  return (*iop->handlers->ftruncate)( iop, length );
+}
+