xref: /openbmc/linux/fs/ntfs/sysctl.c (revision 87c2ce3b)
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 L�wis, R�gis 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 */
86