Define get_init_pts_sb()

	return -ENOMEM;

}

static int compare_init_pts_sb(struct super_block *s, void *p)

{

	if (devpts_mnt)

		return devpts_mnt->mnt_sb == s;

	return 0;

}

/*

 * get_init_pts_sb()

 *

 *     This interface is needed to support multiple namespace semantics in

 *     devpts while preserving backward compatibility of the current 'single-

 *     namespace' semantics. i.e all mounts of devpts without the 'newinstance'

 *     mount option should bind to the initial kernel mount, like

 *     get_sb_single().

 *

 *     Mounts with 'newinstance' option create a new private namespace.

 *

 *     But for single-mount semantics, devpts cannot use get_sb_single(),

 *     because get_sb_single()/sget() find and use the super-block from

 *     the most recent mount of devpts. But that recent mount may be a

 *     'newinstance' mount and get_sb_single() would pick the newinstance

 *     super-block instead of the initial super-block.

 *

 *     This interface is identical to get_sb_single() except that it

 *     consistently selects the 'single-namespace' superblock even in the

 *     presence of the private namespace (i.e 'newinstance') super-blocks.

 */

static int get_init_pts_sb(struct file_system_type *fs_type, int flags,

		void *data, struct vfsmount *mnt)

{

        struct super_block *s;

        int error;

        s = sget(fs_type, compare_init_pts_sb, set_anon_super, NULL);

        if (IS_ERR(s))

                return PTR_ERR(s);

        if (!s->s_root) {

                s->s_flags = flags;

                error = devpts_fill_super(s, data, flags & MS_SILENT ? 1 : 0);

                if (error) {

                        up_write(&s->s_umount);

                        deactivate_super(s);

                        return error;

                }

                s->s_flags |= MS_ACTIVE;

        }

        do_remount_sb(s, flags, data, 0);

        return simple_set_mnt(mnt, s);

}

static int devpts_get_sb(struct file_system_type *fs_type,

	int flags, const char *dev_name, void *data, struct vfsmount *mnt)

{

	return get_sb_single(fs_type, flags, data, devpts_fill_super, mnt);

	return get_init_pts_sb(fs_type, flags, data, mnt);

}

static void devpts_kill_sb(struct super_block *sb)