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, 97 insertions, 0 deletions

diff --git a/c/src/lib/libc/imfs_rmnod.c b/c/src/lib/libc/imfs_rmnod.c
new file mode 100644
index 0000000000..f651622de4
--- /dev/null
+++ b/c/src/lib/libc/imfs_rmnod.c
@@ -0,0 +1,97 @@
+/*
+ *  IMFS_rmnod
+ *
+ *  This routine is available from the optable to remove a node 
+ *  from the IMFS file system.
+ *
+ *  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 <errno.h>
+#include "libio_.h"
+#include "imfs.h"
+
+
+int IMFS_rmnod(
+  rtems_filesystem_location_info_t      *pathloc       /* IN */
+)
+{
+  IMFS_jnode_t *the_jnode;  
+
+  the_jnode = (IMFS_jnode_t *) pathloc->node_access;
+
+  if ( the_jnode->type == IMFS_DIRECTORY ) {
+
+    /* 
+     * You cannot remove a node that still has children 
+     */
+
+    if ( ! Chain_Is_empty( &the_jnode->info.directory.Entries ) )
+       set_errno_and_return_minus_one( ENOTEMPTY );
+
+    /* 
+     * You cannot remove the file system root node.
+     */
+
+    if ( pathloc->mt_entry->mt_fs_root.node_access == pathloc->node_access )
+       set_errno_and_return_minus_one( EBUSY );
+
+    /* 
+     * You cannot remove a mountpoint.
+     */
+
+     if ( the_jnode->info.directory.mt_fs != NULL )
+       set_errno_and_return_minus_one( EBUSY );          
+  } 
+    
+  /* 
+   * Take the node out of the parent's chain that contains this node 
+   */
+  if ( the_jnode->Parent != NULL ) {
+    Chain_Extract( (Chain_Node *) the_jnode );
+    the_jnode->Parent = NULL;
+  }
+
+  /*
+   * Decrement the link counter and see if we can free the space.
+   */
+
+  the_jnode->st_nlink--;
+  IMFS_update_ctime( the_jnode );
+
+  /*
+   * The file cannot be open and the link must be less than 1 to free.
+   */
+
+  if ( !rtems_libio_is_file_open( the_jnode ) && (the_jnode->st_nlink < 1) ) {
+
+    /* 
+     * Is the rtems_filesystem_current is this node?
+     */
+
+    if ( rtems_filesystem_current.node_access == pathloc->node_access )
+       rtems_filesystem_current.node_access = NULL;
+
+    /*
+     * Free memory associated with a memory file.
+     */
+
+    if ( the_jnode->type == IMFS_MEMORY_FILE ) 
+      IMFS_memfile_remove( the_jnode );
+
+    free( the_jnode );
+  }
+
+  return 0;
+
+}
+
+