fs/ntfs/sysctl.c

   1 /*
   2  * sysctl.c - Code for sysctl handling in NTFS Linux kernel driver. Part of
   3  *            the Linux-NTFS project. Adapted from the old NTFS driver,
   4  *            Copyright (C) 1997 Martin von Löwis, Régis Duchesne
   5  *
   6  * Copyright (c) 2002-2005 Anton Altaparmakov
   7  *
   8  * This program/include file is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as published
  10  * by the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program/include file is distributed in the hope that it will be
  14  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program (in the main directory of the Linux-NTFS
  20  * distribution in the file COPYING); if not, write to the Free Software
  21  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #ifdef DEBUG
  25
  26 #include <linux/module.h>
  27
  28 #ifdef CONFIG_SYSCTL
  29
  30 #include <linux/proc_fs.h>
  31 #include <linux/sysctl.h>
  32
  33 #include "sysctl.h"
  34 #include "debug.h"
  35
  36 #define FS_NTFS 1
  37
  38 /* Definition of the ntfs sysctl. */
  39 static ctl_table ntfs_sysctls[] = {
  40         { FS_NTFS, "ntfs-debug",                /* Binary and text IDs. */
  41           &debug_msgs,sizeof(debug_msgs),       /* Data pointer and size. */
  42           0644, NULL, &proc_dointvec },         /* Mode, child, proc handler. */
  43         { 0 }
  44 };
  45
  46 /* Define the parent directory /proc/sys/fs. */
  47 static ctl_table sysctls_root[] = {
  48         { CTL_FS, "fs", NULL, 0, 0555, ntfs_sysctls },
  49         { 0 }
  50 };
  51
  52 /* Storage for the sysctls header. */
  53 static struct ctl_table_header *sysctls_root_table = NULL;
  54
  55 /**
  56  * ntfs_sysctl - add or remove the debug sysctl
  57  * @add:        add (1) or remove (0) the sysctl
  58  *
  59  * Add or remove the debug sysctl. Return 0 on success or -errno on error.
  60  */
  61 int ntfs_sysctl(int add)
  62 {
  63         if (add) {
  64                 BUG_ON(sysctls_root_table);
  65                 sysctls_root_table = register_sysctl_table(sysctls_root, 0);
  66                 if (!sysctls_root_table)
  67                         return -ENOMEM;
  68 #ifdef CONFIG_PROC_FS
  69                 /*
  70                  * If the proc filesystem is in use and we are a module, need
  71                  * to set the owner of our proc entry to our module. In the
  72                  * non-modular case, THIS_MODULE is NULL, so this is ok.
  73                  */
  74                 ntfs_sysctls[0].de->owner = THIS_MODULE;
  75 #endif
  76         } else {
  77                 BUG_ON(!sysctls_root_table);
  78                 unregister_sysctl_table(sysctls_root_table);
  79                 sysctls_root_table = NULL;
  80         }
  81         return 0;
  82 }
  83
  84 #endif /* CONFIG_SYSCTL */
  85 #endif /* DEBUG */