// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * 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

   */
  
  #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 struct 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 struct ctl_table sysctls_root[] = {

  	{

  		.procname	= "fs",
  		.mode		= 0555,
  		.child		= ntfs_sysctls
  	},
  	{}

  };
  
  /* Storage for the sysctls header. */

  static struct ctl_table_header *sysctls_root_table;

  
  /**
   * 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 */