Function crhold

freebsd/kern/kern_prot.c:2012–2028

* Claim another reference to a ucred structure. */

 * Claim another reference to a ucred structure.
 */
struct ucred *
crhold(struct ucred *cr)
{
	struct thread *td;

	td = curthread;
	if (__predict_true(td->td_realucred == cr)) {
		KASSERT(cr->cr_users > 0, ("%s: users %d not > 0 on cred %p",
		    __func__, cr->cr_users, cr));
		td->td_ucredref++;
		return (cr);
	}
	mtx_lock(&cr->cr_mtx);
	cr->cr_ref++;
	mtx_unlock(&cr->cr_mtx);
	return (cr);
}

/*
 * Free a cred structure.  Throws away space when ref count gets to 0.