static int cgroup_may_write(const struct cgroup *cgrp, struct super_block *sb)
{
	int ret;
	struct inode *inode;

	lockdep_assert_held(&cgroup_mutex);

	inode = kernfs_get_inode(sb, cgrp->procs_file.kn);
	if (!inode)
		return -ENOMEM;

	ret = inode_permission(&init_user_ns, inode, MAY_WRITE);
	iput(inode);
	return ret;
}
static int cgroup_may_write(const struct cgroup *cgrp, struct super_block *sb)
{
	int ret;
	struct inode *inode;

	lockdep_assert_held(&cgroup_mutex);

	inode = kernfs_get_inode(sb, cgrp->procs_file.kn);
	if (!inode)
		return -ENOMEM;

	ret = inode_permission(&init_user_ns, inode, MAY_WRITE);
	iput(inode);
	return ret;
}