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 */ 70