sysfs: Create mountpoints with sysfs_create_mount_point

This allows for better documentation in the code and
it allows for a simpler and fully correct version of
fs_fully_visible to be written.

The mount points converted and their filesystems are:
/sys/hypervisor/s390/       s390_hypfs
/sys/kernel/config/         configfs
/sys/kernel/debug/          debugfs
/sys/firmware/efi/efivars/  efivarfs
/sys/fs/fuse/connections/   fusectl
/sys/fs/pstore/             pstore
/sys/kernel/tracing/        tracefs
/sys/fs/cgroup/             cgroup
/sys/kernel/security/       securityfs
/sys/fs/selinux/            selinuxfs
/sys/fs/smackfs/            smackfs

Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c
index da94e41..bca58da 100644
--- a/fs/configfs/mount.c
+++ b/fs/configfs/mount.c
@@ -129,8 +129,6 @@
 }
 
 
-static struct kobject *config_kobj;
-
 static int __init configfs_init(void)
 {
 	int err = -ENOMEM;
@@ -141,8 +139,8 @@
 	if (!configfs_dir_cachep)
 		goto out;
 
-	config_kobj = kobject_create_and_add("config", kernel_kobj);
-	if (!config_kobj)
+	err = sysfs_create_mount_point(kernel_kobj, "config");
+	if (err)
 		goto out2;
 
 	err = register_filesystem(&configfs_fs_type);
@@ -152,7 +150,7 @@
 	return 0;
 out3:
 	pr_err("Unable to register filesystem!\n");
-	kobject_put(config_kobj);
+	sysfs_remove_mount_point(kernel_kobj, "config");
 out2:
 	kmem_cache_destroy(configfs_dir_cachep);
 	configfs_dir_cachep = NULL;
@@ -163,7 +161,7 @@
 static void __exit configfs_exit(void)
 {
 	unregister_filesystem(&configfs_fs_type);
-	kobject_put(config_kobj);
+	sysfs_remove_mount_point(kernel_kobj, "config");
 	kmem_cache_destroy(configfs_dir_cachep);
 	configfs_dir_cachep = NULL;
 }
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index c1e7ffb..1275604 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -716,20 +716,17 @@
 }
 EXPORT_SYMBOL_GPL(debugfs_initialized);
 
-
-static struct kobject *debug_kobj;
-
 static int __init debugfs_init(void)
 {
 	int retval;
 
-	debug_kobj = kobject_create_and_add("debug", kernel_kobj);
-	if (!debug_kobj)
-		return -EINVAL;
+	retval = sysfs_create_mount_point(kernel_kobj, "debug");
+	if (retval)
+		return retval;
 
 	retval = register_filesystem(&debug_fs_type);
 	if (retval)
-		kobject_put(debug_kobj);
+		sysfs_remove_mount_point(kernel_kobj, "debug");
 	else
 		debugfs_registered = true;
 
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 082ac1c..18dacf9 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1238,7 +1238,6 @@
 }
 
 static struct kobject *fuse_kobj;
-static struct kobject *connections_kobj;
 
 static int fuse_sysfs_init(void)
 {
@@ -1250,11 +1249,9 @@
 		goto out_err;
 	}
 
-	connections_kobj = kobject_create_and_add("connections", fuse_kobj);
-	if (!connections_kobj) {
-		err = -ENOMEM;
+	err = sysfs_create_mount_point(fuse_kobj, "connections");
+	if (err)
 		goto out_fuse_unregister;
-	}
 
 	return 0;
 
@@ -1266,7 +1263,7 @@
 
 static void fuse_sysfs_cleanup(void)
 {
-	kobject_put(connections_kobj);
+	sysfs_remove_mount_point(fuse_kobj, "connections");
 	kobject_put(fuse_kobj);
 }
 
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index dc43b5f..3adcc46 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -461,22 +461,18 @@
 	.kill_sb	= pstore_kill_sb,
 };
 
-static struct kobject *pstore_kobj;
-
 static int __init init_pstore_fs(void)
 {
-	int err = 0;
+	int err;
 
 	/* Create a convenient mount point for people to access pstore */
-	pstore_kobj = kobject_create_and_add("pstore", fs_kobj);
-	if (!pstore_kobj) {
-		err = -ENOMEM;
+	err = sysfs_create_mount_point(fs_kobj, "pstore");
+	if (err)
 		goto out;
-	}
 
 	err = register_filesystem(&pstore_fs_type);
 	if (err < 0)
-		kobject_put(pstore_kobj);
+		sysfs_remove_mount_point(fs_kobj, "pstore");
 
 out:
 	return err;
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index d92bdf3..a43df11 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -631,14 +631,12 @@
 	return tracefs_registered;
 }
 
-static struct kobject *trace_kobj;
-
 static int __init tracefs_init(void)
 {
 	int retval;
 
-	trace_kobj = kobject_create_and_add("tracing", kernel_kobj);
-	if (!trace_kobj)
+	retval = sysfs_create_mount_point(kernel_kobj, "tracing");
+	if (retval)
 		return -EINVAL;
 
 	retval = register_filesystem(&trace_fs_type);