Read Only EFS for everyone except single ec2 instance

Hello.
Is the IAM policy of the EC2 to be written a policy that allows writing as follows?
Also, what is EFS's access policy?

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "elasticfilesystem:ClientMount",
                "elasticfilesystem:ClientWrite",
                "elasticfilesystem:ClientRootAccess"
            ],
            "Resource": "arn:aws:elasticfilesystem:region-id:[YourAccount]:file-system/fs-xxxxx"
        }
    ]
}

Also, make sure you are mounting using IAM authentication.
https://docs.aws.amazon.com/efs/latest/ug/mounting-IAM-option.html