fs: move locking sysctls where they are used

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.

The locking fs sysctls are only used on fs/locks.c, so move them there.

Link: https://lkml.kernel.org/r/20211129205548.605569-7-mcgrof@kernel.orgSigned-off-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lukas Middendorf <kernel@tuxforce.de>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/locks.c

@@ -62,6 +62,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/hashtable.h>
 #include <linux/percpu.h>
+#include <linux/sysctl.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/filelock.h>
@@ -88,8 +89,37 @@ static int target_leasetype(struct file_lock *fl)
 	return fl->fl_type;
 }
 
-int leases_enable = 1;
-int lease_break_time = 45;
+static int leases_enable = 1;
+static int lease_break_time = 45;
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table locks_sysctls[] = {
+	{
+		.procname	= "leases-enable",
+		.data		= &leases_enable,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+#ifdef CONFIG_MMU
+	{
+		.procname	= "lease-break-time",
+		.data		= &lease_break_time,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+#endif /* CONFIG_MMU */
+	{}
+};
+
+static int __init init_fs_locks_sysctls(void)
+{
+	register_sysctl_init("fs", locks_sysctls);
+	return 0;
+}
+early_initcall(init_fs_locks_sysctls);
+#endif /* CONFIG_SYSCTL */
 
 /*
  * The global file_lock_list is only used for displaying /proc/locks, so we

include/linux/fs.h

@@ -82,10 +82,6 @@ extern void __init files_maxfiles_init(void);
 extern unsigned long get_max_files(void);
 extern unsigned int sysctl_nr_open;
 extern int leases_enable, lease_break_time;
-extern int sysctl_protected_symlinks;
-extern int sysctl_protected_hardlinks;
-extern int sysctl_protected_fifos;
-extern int sysctl_protected_regular;
 
 typedef __kernel_rwf_t rwf_t;
 

kernel/sysctl.c

@@ -2897,26 +2897,6 @@ static struct ctl_table vm_table[] = {
 };
 
 static struct ctl_table fs_table[] = {
-#ifdef CONFIG_FILE_LOCKING
-	{
-		.procname	= "leases-enable",
-		.data		= &leases_enable,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
-#endif
-#ifdef CONFIG_MMU
-#ifdef CONFIG_FILE_LOCKING
-	{
-		.procname	= "lease-break-time",
-		.data		= &lease_break_time,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
-#endif
-#endif
 	{
 		.procname	= "protected_symlinks",
 		.data		= &sysctl_protected_symlinks,