Subject: [PATCH v2 6/8] inotify: simplify subdirectory registration with register_sysctl()

From: Luis Chamberlain <[email-masked]>
Date: Tue, 23 Nov 2021 12:24:20 -0800

From: Xiaoming Ni <[email-masked]>

There is no need to user boiler plate code to specify a set of base
directories we're going to stuff sysctls under. Simplify this by using
register_sysctl() and specifying the directory path directly.

Move inotify_user sysctl to inotify_user.c while at it to remove clutter
from kernel/sysctl.c.

Signed-off-by: Xiaoming Ni <[email-masked]>
[mcgrof: update commit log to reflect new path we decided to take]
Signed-off-by: Luis Chamberlain <[email-masked]>
---
 fs/notify/inotify/inotify_user.c | 11 ++++++++++-
 include/linux/inotify.h          |  3 ---
 kernel/sysctl.c                  | 21 ---------------------
 3 files changed, 10 insertions(+), 25 deletions(-)

diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 29fca3284bb5..54583f62dc44 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -58,7 +58,7 @@ struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
 static long it_zero = 0;
 static long it_int_max = INT_MAX;
 
-struct ctl_table inotify_table[] = {
+static struct ctl_table inotify_table[] = {
 	{
 		.procname	= "max_user_instances",
 		.data		= &init_user_ns.ucount_max[UCOUNT_INOTIFY_INSTANCES],
@@ -87,6 +87,14 @@ struct ctl_table inotify_table[] = {
 	},
 	{ }
 };
+
+static void __init inotify_sysctls_init(void)
+{
+	register_sysctl("fs/inotify", inotify_table);
+}
+
+#else
+#define inotify_sysctls_init() do { } while (0)
 #endif /* CONFIG_SYSCTL */
 
 static inline __u32 inotify_arg_to_mask(struct inode *inode, u32 arg)
@@ -849,6 +857,7 @@ static int __init inotify_user_setup(void)
 	inotify_max_queued_events = 16384;
 	init_user_ns.ucount_max[UCOUNT_INOTIFY_INSTANCES] = 128;
 	init_user_ns.ucount_max[UCOUNT_INOTIFY_WATCHES] = watches_max;
+	inotify_sysctls_init();
 
 	return 0;
 }
diff --git a/include/linux/inotify.h b/include/linux/inotify.h
index 6a24905f6e1e..8d20caa1b268 100644
--- a/include/linux/inotify.h
+++ b/include/linux/inotify.h
@@ -7,11 +7,8 @@
 #ifndef _LINUX_INOTIFY_H
 #define _LINUX_INOTIFY_H
 
-#include <linux/sysctl.h>
 #include <uapi/linux/inotify.h>
 
-extern struct ctl_table inotify_table[]; /* for sysctl */
-
 #define ALL_INOTIFY_BITS (IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE | \
 			  IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM | \
 			  IN_MOVED_TO | IN_CREATE | IN_DELETE | \
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 7a90a12b9ea4..6aa67c737e4e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -125,13 +125,6 @@ static const int maxolduid = 65535;
 static const int ngroups_max = NGROUPS_MAX;
 static const int cap_last_cap = CAP_LAST_CAP;
 
-#ifdef CONFIG_INOTIFY_USER
-#include <linux/inotify.h>
-#endif
-#ifdef CONFIG_FANOTIFY
-#include <linux/fanotify.h>
-#endif
-
 #ifdef CONFIG_PROC_SYSCTL
 
 /**
@@ -3099,20 +3092,6 @@ static struct ctl_table fs_table[] = {
 		.proc_handler	= proc_dointvec,
 	},
 #endif
-#ifdef CONFIG_INOTIFY_USER
-	{
-		.procname	= "inotify",
-		.mode		= 0555,
-		.child		= inotify_table,
-	},
-#endif
-#ifdef CONFIG_FANOTIFY
-	{
-		.procname	= "fanotify",
-		.mode		= 0555,
-		.child		= fanotify_table,
-	},
-#endif
 #ifdef CONFIG_EPOLL
 	{
 		.procname	= "epoll",
-- 
2.33.0