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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 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02005 * SPDX-License-Identifier: GPL-2.0+
Jorgen Lundman4d3c95f2012-07-19 20:48:25 +00006 */
7/*
8 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
9 * Use is subject to license terms.
10 */
11
12#ifndef _SYS_UBERBLOCK_IMPL_H
13#define _SYS_UBERBLOCK_IMPL_H
14
15#define UBMAX(a, b) ((a) > (b) ? (a) : (b))
16
17/*
18 * The uberblock version is incremented whenever an incompatible on-disk
19 * format change is made to the SPA, DMU, or ZAP.
20 *
21 * Note: the first two fields should never be moved. When a storage pool
22 * is opened, the uberblock must be read off the disk before the version
23 * can be checked. If the ub_version field is moved, we may not detect
24 * version mismatch. If the ub_magic field is moved, applications that
25 * expect the magic number in the first word won't work.
26 */
27#define UBERBLOCK_MAGIC 0x00bab10c /* oo-ba-bloc! */
28#define UBERBLOCK_SHIFT 10 /* up to 1K */
29
30typedef struct uberblock {
31 uint64_t ub_magic; /* UBERBLOCK_MAGIC */
32 uint64_t ub_version; /* ZFS_VERSION */
33 uint64_t ub_txg; /* txg of last sync */
34 uint64_t ub_guid_sum; /* sum of all vdev guids */
35 uint64_t ub_timestamp; /* UTC time of last sync */
36 blkptr_t ub_rootbp; /* MOS objset_phys_t */
37} uberblock_t;
38
39#define VDEV_UBERBLOCK_SHIFT(as) UBMAX(as, UBERBLOCK_SHIFT)
40#define UBERBLOCK_SIZE(as) (1ULL << VDEV_UBERBLOCK_SHIFT(as))
41
42/* Number of uberblocks that can fit in the ring at a given ashift */
43#define UBERBLOCK_COUNT(as) (VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(as))
44
45#endif /* _SYS_UBERBLOCK_IMPL_H */