Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs mount updates from Al Viro:
 "The first part of mount updates.

  Convert filesystems to use the new mount API"

* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  mnt_init(): call shmem_init() unconditionally
  constify ksys_mount() string arguments
  don't bother with registering rootfs
  init_rootfs(): don't bother with init_ramfs_fs()
  vfs: Convert smackfs to use the new mount API
  vfs: Convert selinuxfs to use the new mount API
  vfs: Convert securityfs to use the new mount API
  vfs: Convert apparmorfs to use the new mount API
  vfs: Convert openpromfs to use the new mount API
  vfs: Convert xenfs to use the new mount API
  vfs: Convert gadgetfs to use the new mount API
  vfs: Convert oprofilefs to use the new mount API
  vfs: Convert ibmasmfs to use the new mount API
  vfs: Convert qib_fs/ipathfs to use the new mount API
  vfs: Convert efivarfs to use the new mount API
  vfs: Convert configfs to use the new mount API
  vfs: Convert binfmt_misc to use the new mount API
  convenience helper: get_tree_single()
  convenience helper get_tree_nodev()
  vfs: Kill sget_userns()
  ...

init/do_mounts.c

@@ -630,41 +630,23 @@ static bool is_tmpfs;
 static struct dentry *rootfs_mount(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *data)
 {
-	static unsigned long once;
 	void *fill = ramfs_fill_super;
 
-	if (test_and_set_bit(0, &once))
-		return ERR_PTR(-ENODEV);
-
 	if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
 		fill = shmem_fill_super;
 
 	return mount_nodev(fs_type, flags, data, fill);
 }
 
-static struct file_system_type rootfs_fs_type = {
+struct file_system_type rootfs_fs_type = {
 	.name		= "rootfs",
 	.mount		= rootfs_mount,
 	.kill_sb	= kill_litter_super,
 };
 
-int __init init_rootfs(void)
+void __init init_rootfs(void)
 {
-	int err = register_filesystem(&rootfs_fs_type);
-
-	if (err)
-		return err;
-
 	if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
-		(!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
-		err = shmem_init();
+		(!root_fs_names || strstr(root_fs_names, "tmpfs")))
 		is_tmpfs = true;
-	} else {
-		err = init_ramfs_fs();
-	}
-
-	if (err)
-		unregister_filesystem(&rootfs_fs_type);
-
-	return err;
 }