/*
   * sysctl.c - Code for sysctl handling in NTFS Linux kernel driver. Part of
   *	      the Linux-NTFS project. Adapted from the old NTFS driver,
   *	      Copyright (C) 1997 Martin von Löwis, Régis Duchesne
   *
   * Copyright (c) 2002-2005 Anton Altaparmakov
   *
   * This program/include file is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License as published
   * by the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program/include file is distributed in the hope that it will be
   * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
   * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program (in the main directory of the Linux-NTFS
   * distribution in the file COPYING); if not, write to the Free Software
   * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  #ifdef DEBUG
  
  #include <linux/module.h>
  
  #ifdef CONFIG_SYSCTL
  
  #include <linux/proc_fs.h>
  #include <linux/sysctl.h>
  
  #include "sysctl.h"
  #include "debug.h"
  
  /* Definition of the ntfs sysctl. */
  static ctl_table ntfs_sysctls[] = {
  	{
  		.procname	= "ntfs-debug",
  		.data		= &debug_msgs,		/* Data pointer and size. */
  		.maxlen		= sizeof(debug_msgs),
  		.mode		= 0644,			/* Mode, proc handler. */
  		.proc_handler	= proc_dointvec
  	},
  	{}
  };
  
  /* Define the parent directory /proc/sys/fs. */
  static ctl_table sysctls_root[] = {
  	{
  		.procname	= "fs",
  		.mode		= 0555,
  		.child		= ntfs_sysctls
  	},
  	{}
  };
  
  /* Storage for the sysctls header. */
  static struct ctl_table_header *sysctls_root_table = NULL;
  
  /**
   * ntfs_sysctl - add or remove the debug sysctl
   * @add:	add (1) or remove (0) the sysctl
   *
   * Add or remove the debug sysctl. Return 0 on success or -errno on error.
   */
  int ntfs_sysctl(int add)
  {
  	if (add) {
  		BUG_ON(sysctls_root_table);
  		sysctls_root_table = register_sysctl_table(sysctls_root);
  		if (!sysctls_root_table)
  			return -ENOMEM;
  	} else {
  		BUG_ON(!sysctls_root_table);
  		unregister_sysctl_table(sysctls_root_table);
  		sysctls_root_table = NULL;
  	}
  	return 0;
  }
  
  #endif /* CONFIG_SYSCTL */
  #endif /* DEBUG */