Function dnode_hold

freebsd/contrib/openzfs/module/zfs/dnode.c:1573–1578

* Return held dnode if the object is allocated, NULL if not. */

 * Return held dnode if the object is allocated, NULL if not.
 */
int
dnode_hold(objset_t *os, uint64_t object, void *tag, dnode_t **dnp)
{
	return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag,
	    dnp));
}

/*
 * Can only add a reference if there is already at least one