blob: 806da9585c84c36da9a53be5e96d171d90f8b02f [file] [log] [blame]
Jorgen Lundman4d3c95f2012-07-19 20:48:25 +00001/*
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#define UBMAX(a, b) ((a) > (b) ? (a) : (b))
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
42typedef 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} uberblock_t;
50
51#define VDEV_UBERBLOCK_SHIFT(as) UBMAX(as, UBERBLOCK_SHIFT)
52#define UBERBLOCK_SIZE(as) (1ULL << VDEV_UBERBLOCK_SHIFT(as))
53
54/* Number of uberblocks that can fit in the ring at a given ashift */
55#define UBERBLOCK_COUNT(as) (VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(as))
56
57#endif /* _SYS_UBERBLOCK_IMPL_H */