xref: /illumos-gate/usr/src/uts/common/fs/zfs/uberblock.c (revision 04427e3bf236c18cc532680b957267ee70b1037d)
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2013, 2014 by Delphix. All rights reserved.
24  */
25 
26 #include <sys/zfs_context.h>
27 #include <sys/uberblock_impl.h>
28 #include <sys/vdev_impl.h>
29 
30 int
31 uberblock_verify(uberblock_t *ub)
32 {
33 	if (ub->ub_magic == BSWAP_64((uint64_t)UBERBLOCK_MAGIC))
34 		byteswap_uint64_array(ub, sizeof (uberblock_t));
35 
36 	if (ub->ub_magic != UBERBLOCK_MAGIC)
37 		return (SET_ERROR(EINVAL));
38 
39 	return (0);
40 }
41 
42 /*
43  * Update the uberblock and return TRUE if anything changed in this
44  * transaction group.
45  */
46 boolean_t
47 uberblock_update(uberblock_t *ub, vdev_t *rvd, uint64_t txg)
48 {
49 	ASSERT(ub->ub_txg < txg);
50 
51 	/*
52 	 * We explicitly do not set ub_version here, so that older versions
53 	 * continue to be written with the previous uberblock version.
54 	 */
55 	ub->ub_magic = UBERBLOCK_MAGIC;
56 	ub->ub_txg = txg;
57 	ub->ub_guid_sum = rvd->vdev_guid_sum;
58 	ub->ub_timestamp = gethrestime_sec();
59 	ub->ub_software_version = SPA_VERSION;
60 
61 	return (ub->ub_rootbp.blk_birth == txg);
62 }
63