fs: move fs stat sysctls to file_table.c

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.

We can create the sysctl dynamically on early init for fs stat to help
with this clutter.  This dusts off the fs stat syctls knobs and puts
them into where they are declared.

Link: https://lkml.kernel.org/r/20211129205548.605569-3-mcgrof@kernel.org
Signed-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>

diff --git a/fs/file_table.c b/fs/file_table.c
index 45437f8e1003e6d80b6775efa4f9bf15995b1fd6..57edef16dce468422bd36f5a94d40e0f9d403347 100644 (file)
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -33,7 +33,7 @@
 #include "internal.h"
 
 /* sysctl tunables... */
-struct files_stat_struct files_stat = {
+static struct files_stat_struct files_stat = {
        .max_files = NR_FILE
 };
 
@@ -75,22 +75,53 @@ unsigned long get_max_files(void)
 }
 EXPORT_SYMBOL_GPL(get_max_files);
 
+#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
+
 /*
  * Handle nr_files sysctl
  */
-#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
-int proc_nr_files(struct ctl_table *table, int write,
-                     void *buffer, size_t *lenp, loff_t *ppos)
+static int proc_nr_files(struct ctl_table *table, int write, void *buffer,
+                        size_t *lenp, loff_t *ppos)
 {
        files_stat.nr_files = get_nr_files();
        return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 }
-#else
-int proc_nr_files(struct ctl_table *table, int write,
-                     void *buffer, size_t *lenp, loff_t *ppos)
+
+static struct ctl_table fs_stat_sysctls[] = {
+       {
+               .procname       = "file-nr",
+               .data           = &files_stat,
+               .maxlen         = sizeof(files_stat),
+               .mode           = 0444,
+               .proc_handler   = proc_nr_files,
+       },
+       {
+               .procname       = "file-max",
+               .data           = &files_stat.max_files,
+               .maxlen         = sizeof(files_stat.max_files),
+               .mode           = 0644,
+               .proc_handler   = proc_doulongvec_minmax,
+               .extra1         = SYSCTL_LONG_ZERO,
+               .extra2         = SYSCTL_LONG_MAX,
+       },
+       {
+               .procname       = "nr_open",
+               .data           = &sysctl_nr_open,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec_minmax,
+               .extra1         = &sysctl_nr_open_min,
+               .extra2         = &sysctl_nr_open_max,
+       },
+       { }
+};
+
+static int __init init_fs_stat_sysctls(void)
 {
-       return -ENOSYS;
+       register_sysctl_init("fs", fs_stat_sysctls);
+       return 0;
 }
+fs_initcall(init_fs_stat_sysctls);
 #endif
 
 static struct file *__alloc_file(int flags, const struct cred *cred)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 044de67c8167280e999b07c8258be019d3599844..1e676196612030a2dcf591fb9901e3c111c3ffff 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -79,7 +79,6 @@ extern void __init inode_init_early(void);
 extern void __init files_init(void);
 extern void __init files_maxfiles_init(void);
 
-extern struct files_stat_struct files_stat;
 extern unsigned long get_max_files(void);
 extern unsigned int sysctl_nr_open;
 extern int leases_enable, lease_break_time;
@@ -3532,8 +3531,6 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf,
                          size_t len, loff_t *ppos);
 
 struct ctl_table;
-int proc_nr_files(struct ctl_table *table, int write,
-                 void *buffer, size_t *lenp, loff_t *ppos);
 int proc_nr_dentry(struct ctl_table *table, int write,
                  void *buffer, size_t *lenp, loff_t *ppos);
 int __init list_bdev_fs_names(char *buf, size_t size);

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 402c9d3246bfb50b72985a639a7ffd824cc192f4..d2c411b158540590590d865193eb16c312ee6008 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2901,31 +2901,6 @@ static struct ctl_table vm_table[] = {
 };
 
 static struct ctl_table fs_table[] = {
-       {
-               .procname       = "file-nr",
-               .data           = &files_stat,
-               .maxlen         = sizeof(files_stat),
-               .mode           = 0444,
-               .proc_handler   = proc_nr_files,
-       },
-       {
-               .procname       = "file-max",
-               .data           = &files_stat.max_files,
-               .maxlen         = sizeof(files_stat.max_files),
-               .mode           = 0644,
-               .proc_handler   = proc_doulongvec_minmax,
-               .extra1         = SYSCTL_LONG_ZERO,
-               .extra2         = SYSCTL_LONG_MAX,
-       },
-       {
-               .procname       = "nr_open",
-               .data           = &sysctl_nr_open,
-               .maxlen         = sizeof(unsigned int),
-               .mode           = 0644,
-               .proc_handler   = proc_dointvec_minmax,
-               .extra1         = &sysctl_nr_open_min,
-               .extra2         = &sysctl_nr_open_max,
-       },
        {
                .procname       = "dentry-state",
                .data           = &dentry_stat,