fs/ntfs/sysctl.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * sysctl.c - Code for sysctl handling in NTFS Linux kernel driver. Part of
   4  *            the Linux-NTFS project. Adapted from the old NTFS driver,
   5  *            Copyright (C) 1997 Martin von Löwis, Régis Duchesne
   6  *
   7  * Copyright (c) 2002-2005 Anton Altaparmakov
   8  */
   9
  10 #ifdef DEBUG
  11
  12 #include <linux/module.h>
  13
  14 #ifdef CONFIG_SYSCTL
  15
  16 #include <linux/proc_fs.h>
  17 #include <linux/sysctl.h>
  18
  19 #include "sysctl.h"
  20 #include "debug.h"
  21
  22 /* Definition of the ntfs sysctl. */
  23 static struct ctl_table ntfs_sysctls[] = {
  24         {
  25                 .procname       = "ntfs-debug",
  26                 .data           = &debug_msgs,          /* Data pointer and size. */
  27                 .maxlen         = sizeof(debug_msgs),
  28                 .mode           = 0644,                 /* Mode, proc handler. */
  29                 .proc_handler   = proc_dointvec
  30         },
  31         {}
  32 };
  33
  34 /* Define the parent directory /proc/sys/fs. */
  35 static struct ctl_table sysctls_root[] = {
  36         {
  37                 .procname       = "fs",
  38                 .mode           = 0555,
  39                 .child          = ntfs_sysctls
  40         },
  41         {}
  42 };
  43
  44 /* Storage for the sysctls header. */
  45 static struct ctl_table_header *sysctls_root_table;
  46
  47 /**
  48  * ntfs_sysctl - add or remove the debug sysctl
  49  * @add:        add (1) or remove (0) the sysctl
  50  *
  51  * Add or remove the debug sysctl. Return 0 on success or -errno on error.
  52  */
  53 int ntfs_sysctl(int add)
  54 {
  55         if (add) {
  56                 BUG_ON(sysctls_root_table);
  57                 sysctls_root_table = register_sysctl_table(sysctls_root);
  58                 if (!sysctls_root_table)
  59                         return -ENOMEM;
  60         } else {
  61                 BUG_ON(!sysctls_root_table);
  62                 unregister_sysctl_table(sysctls_root_table);
  63                 sysctls_root_table = NULL;
  64         }
  65         return 0;
  66 }
  67
  68 #endif /* CONFIG_SYSCTL */
  69 #endif /* DEBUG */