uberblock.c revision 168404 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#pragma ident	"%Z%%M%	%I%	%E% SMI"
27
28#include <sys/zfs_context.h>
29#include <sys/uberblock_impl.h>
30#include <sys/vdev_impl.h>
31
32int
33uberblock_verify(uberblock_t *ub)
34{
35	if (ub->ub_magic == BSWAP_64((uint64_t)UBERBLOCK_MAGIC))
36		byteswap_uint64_array(ub, sizeof (uberblock_t));
37
38	if (ub->ub_magic != UBERBLOCK_MAGIC)
39		return (EINVAL);
40
41	return (0);
42}
43
44/*
45 * Update the uberblock and return a boolean value indicating whether
46 * anything changed in this transaction group.
47 */
48int
49uberblock_update(uberblock_t *ub, vdev_t *rvd, uint64_t txg)
50{
51	ASSERT(ub->ub_txg < txg);
52
53	/*
54	 * We explicitly do not set ub_version here, so that older versions
55	 * continue to be written with the previous uberblock version.
56	 */
57	ub->ub_magic = UBERBLOCK_MAGIC;
58	ub->ub_txg = txg;
59	ub->ub_guid_sum = rvd->vdev_guid_sum;
60	ub->ub_timestamp = gethrestime_sec();
61
62	return (ub->ub_rootbp.blk_birth == txg);
63}
64