uberblock_impl.h revision 8188:fd00c0a81e80 
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 2008 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#ifndef _SYS_UBERBLOCK_IMPL_H
27#define	_SYS_UBERBLOCK_IMPL_H
28
29#include <sys/uberblock.h>
30
31#ifdef	__cplusplus
32extern "C" {
33#endif
34
35/*
36 * For zdb use and debugging purposes only
37 */
38extern uint64_t ub_max_txg;
39
40/*
41 * The uberblock version is incremented whenever an incompatible on-disk
42 * format change is made to the SPA, DMU, or ZAP.
43 *
44 * Note: the first two fields should never be moved.  When a storage pool
45 * is opened, the uberblock must be read off the disk before the version
46 * can be checked.  If the ub_version field is moved, we may not detect
47 * version mismatch.  If the ub_magic field is moved, applications that
48 * expect the magic number in the first word won't work.
49 */
50#define	UBERBLOCK_MAGIC		0x00bab10c		/* oo-ba-bloc!	*/
51#define	UBERBLOCK_SHIFT		10			/* up to 1K	*/
52
53struct uberblock {
54	uint64_t	ub_magic;	/* UBERBLOCK_MAGIC		*/
55	uint64_t	ub_version;	/* SPA_VERSION			*/
56	uint64_t	ub_txg;		/* txg of last sync		*/
57	uint64_t	ub_guid_sum;	/* sum of all vdev guids	*/
58	uint64_t	ub_timestamp;	/* UTC time of last sync	*/
59	blkptr_t	ub_rootbp;	/* MOS objset_phys_t		*/
60};
61
62#ifdef	__cplusplus
63}
64#endif
65
66#endif	/* _SYS_UBERBLOCK_IMPL_H */
67