xref: /illumos-gate/usr/src/grub/grub-0.97/stage2/zfs-include/uberblock_impl.h (revision b1b8ab34de515a5e83206da22c3d7e563241b021)
1 /*
2  *  GRUB  --  GRand Unified Bootloader
3  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; if not, write to the Free Software
17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18  */
19 /*
20  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
21  * Use is subject to license terms.
22  */
23 
24 #ifndef _SYS_UBERBLOCK_IMPL_H
25 #define	_SYS_UBERBLOCK_IMPL_H
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * The uberblock version is incremented whenever an incompatible on-disk
31  * format change is made to the SPA, DMU, or ZAP.
32  *
33  * Note: the first two fields should never be moved.  When a storage pool
34  * is opened, the uberblock must be read off the disk before the version
35  * can be checked.  If the ub_version field is moved, we may not detect
36  * version mismatch.  If the ub_magic field is moved, applications that
37  * expect the magic number in the first word won't work.
38  */
39 #define	UBERBLOCK_MAGIC		0x00bab10c		/* oo-ba-bloc!	*/
40 #define	UBERBLOCK_SHIFT		10			/* up to 1K	*/
41 
42 struct uberblock {
43 	uint64_t	ub_magic;	/* UBERBLOCK_MAGIC		*/
44 	uint64_t	ub_version;	/* ZFS_VERSION			*/
45 	uint64_t	ub_txg;		/* txg of last sync		*/
46 	uint64_t	ub_guid_sum;	/* sum of all vdev guids	*/
47 	uint64_t	ub_timestamp;	/* UTC time of last sync	*/
48 	blkptr_t	ub_rootbp;	/* MOS objset_phys_t		*/
49 };
50 
51 #endif	/* _SYS_UBERBLOCK_IMPL_H */
52