xref: /openbmc/linux/fs/ntfs/sysctl.c (revision 8e9356c6)
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 /* Definition of the ntfs sysctl. */
37 static ctl_table ntfs_sysctls[] = {
38 	{
39 		.procname	= "ntfs-debug",
40 		.data		= &debug_msgs,		/* Data pointer and size. */
41 		.maxlen		= sizeof(debug_msgs),
42 		.mode		= 0644,			/* Mode, proc handler. */
43 		.proc_handler	= proc_dointvec
44 	},
45 	{}
46 };
47 
48 /* Define the parent directory /proc/sys/fs. */
49 static ctl_table sysctls_root[] = {
50 	{
51 		.procname	= "fs",
52 		.mode		= 0555,
53 		.child		= ntfs_sysctls
54 	},
55 	{}
56 };
57 
58 /* Storage for the sysctls header. */
59 static struct ctl_table_header *sysctls_root_table = NULL;
60 
61 /**
62  * ntfs_sysctl - add or remove the debug sysctl
63  * @add:	add (1) or remove (0) the sysctl
64  *
65  * Add or remove the debug sysctl. Return 0 on success or -errno on error.
66  */
67 int ntfs_sysctl(int add)
68 {
69 	if (add) {
70 		BUG_ON(sysctls_root_table);
71 		sysctls_root_table = register_sysctl_table(sysctls_root);
72 		if (!sysctls_root_table)
73 			return -ENOMEM;
74 	} else {
75 		BUG_ON(!sysctls_root_table);
76 		unregister_sysctl_table(sysctls_root_table);
77 		sysctls_root_table = NULL;
78 	}
79 	return 0;
80 }
81 
82 #endif /* CONFIG_SYSCTL */
83 #endif /* DEBUG */
84