Function key_mapping_add_ref

freebsd/contrib/openzfs/module/zfs/dsl_crypt.c:939–944

}

void
key_mapping_add_ref(dsl_key_mapping_t *km, void *tag)
{
	ASSERT3U(zfs_refcount_count(&km->km_refcnt), >=, 1);
	zfs_refcount_add(&km->km_refcnt, tag);
}

/*
 * The locking here is a little tricky to ensure we don't cause unnecessary