Function prison_isvalid

freebsd/kern/kern_jail.c:3079–3086

* Return true if the prison is currently valid. A prison is valid if it has * been fully created, and is not being destroyed. Note that dying prisons * are still considered valid. */

 * are still considered valid.
 */
bool
prison_isvalid(struct prison *pr)
{

	if (__predict_false(refcount_load(&pr->pr_ref) == 0))
		return (false);
	return (true);
}

/*
 * Return 1 if the passed credential is in a jail and that jail does not