xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/uberblock_impl.h (revision ecc2d604e885a75cc75e647b5641af99d5a6f4a6)
1fa9e4066Sahrens /*
2fa9e4066Sahrens  * CDDL HEADER START
3fa9e4066Sahrens  *
4fa9e4066Sahrens  * The contents of this file are subject to the terms of the
5*ecc2d604Sbonwick  * Common Development and Distribution License (the "License").
6*ecc2d604Sbonwick  * You may not use this file except in compliance with the License.
7fa9e4066Sahrens  *
8fa9e4066Sahrens  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9fa9e4066Sahrens  * or http://www.opensolaris.org/os/licensing.
10fa9e4066Sahrens  * See the License for the specific language governing permissions
11fa9e4066Sahrens  * and limitations under the License.
12fa9e4066Sahrens  *
13fa9e4066Sahrens  * When distributing Covered Code, include this CDDL HEADER in each
14fa9e4066Sahrens  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15fa9e4066Sahrens  * If applicable, add the following below this CDDL HEADER, with the
16fa9e4066Sahrens  * fields enclosed by brackets "[]" replaced with your own identifying
17fa9e4066Sahrens  * information: Portions Copyright [yyyy] [name of copyright owner]
18fa9e4066Sahrens  *
19fa9e4066Sahrens  * CDDL HEADER END
20fa9e4066Sahrens  */
21fa9e4066Sahrens /*
22*ecc2d604Sbonwick  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23fa9e4066Sahrens  * Use is subject to license terms.
24fa9e4066Sahrens  */
25fa9e4066Sahrens 
26fa9e4066Sahrens #ifndef _SYS_UBERBLOCK_IMPL_H
27fa9e4066Sahrens #define	_SYS_UBERBLOCK_IMPL_H
28fa9e4066Sahrens 
29fa9e4066Sahrens #pragma ident	"%Z%%M%	%I%	%E% SMI"
30fa9e4066Sahrens 
31fa9e4066Sahrens #include <sys/uberblock.h>
32fa9e4066Sahrens 
33fa9e4066Sahrens #ifdef	__cplusplus
34fa9e4066Sahrens extern "C" {
35fa9e4066Sahrens #endif
36fa9e4066Sahrens 
37fa9e4066Sahrens /*
38fa9e4066Sahrens  * The uberblock version is incremented whenever an incompatible on-disk
39fa9e4066Sahrens  * format change is made to the SPA, DMU, or ZAP.
40fa9e4066Sahrens  *
41fa9e4066Sahrens  * Note: the first two fields should never be moved.  When a storage pool
42fa9e4066Sahrens  * is opened, the uberblock must be read off the disk before the version
43fa9e4066Sahrens  * can be checked.  If the ub_version field is moved, we may not detect
44fa9e4066Sahrens  * version mismatch.  If the ub_magic field is moved, applications that
45fa9e4066Sahrens  * expect the magic number in the first word won't work.
46fa9e4066Sahrens  */
47fa9e4066Sahrens #define	UBERBLOCK_MAGIC		0x00bab10c		/* oo-ba-bloc!	*/
48fa9e4066Sahrens #define	UBERBLOCK_VERSION	1ULL
49*ecc2d604Sbonwick #define	UBERBLOCK_SHIFT		10			/* up to 1K	*/
50fa9e4066Sahrens 
51fa9e4066Sahrens struct uberblock {
52fa9e4066Sahrens 	uint64_t	ub_magic;	/* UBERBLOCK_MAGIC		*/
53fa9e4066Sahrens 	uint64_t	ub_version;	/* UBERBLOCK_VERSION		*/
54fa9e4066Sahrens 	uint64_t	ub_txg;		/* txg of last sync		*/
55fa9e4066Sahrens 	uint64_t	ub_guid_sum;	/* sum of all vdev guids	*/
56fa9e4066Sahrens 	uint64_t	ub_timestamp;	/* UTC time of last sync	*/
57fa9e4066Sahrens 	blkptr_t	ub_rootbp;	/* MOS objset_phys_t		*/
58fa9e4066Sahrens };
59fa9e4066Sahrens 
60fa9e4066Sahrens #ifdef	__cplusplus
61fa9e4066Sahrens }
62fa9e4066Sahrens #endif
63fa9e4066Sahrens 
64fa9e4066Sahrens #endif	/* _SYS_UBERBLOCK_IMPL_H */
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