1*4882a593Smuzhiyun /* 2*4882a593Smuzhiyun * GRUB -- GRand Unified Bootloader 3*4882a593Smuzhiyun * Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc. 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * SPDX-License-Identifier: GPL-2.0+ 6*4882a593Smuzhiyun */ 7*4882a593Smuzhiyun /* 8*4882a593Smuzhiyun * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 9*4882a593Smuzhiyun * Use is subject to license terms. 10*4882a593Smuzhiyun */ 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun #ifndef _SYS_UBERBLOCK_IMPL_H 13*4882a593Smuzhiyun #define _SYS_UBERBLOCK_IMPL_H 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun #define UBMAX(a, b) ((a) > (b) ? (a) : (b)) 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun /* 18*4882a593Smuzhiyun * The uberblock version is incremented whenever an incompatible on-disk 19*4882a593Smuzhiyun * format change is made to the SPA, DMU, or ZAP. 20*4882a593Smuzhiyun * 21*4882a593Smuzhiyun * Note: the first two fields should never be moved. When a storage pool 22*4882a593Smuzhiyun * is opened, the uberblock must be read off the disk before the version 23*4882a593Smuzhiyun * can be checked. If the ub_version field is moved, we may not detect 24*4882a593Smuzhiyun * version mismatch. If the ub_magic field is moved, applications that 25*4882a593Smuzhiyun * expect the magic number in the first word won't work. 26*4882a593Smuzhiyun */ 27*4882a593Smuzhiyun #define UBERBLOCK_MAGIC 0x00bab10c /* oo-ba-bloc! */ 28*4882a593Smuzhiyun #define UBERBLOCK_SHIFT 10 /* up to 1K */ 29*4882a593Smuzhiyun 30*4882a593Smuzhiyun typedef struct uberblock { 31*4882a593Smuzhiyun uint64_t ub_magic; /* UBERBLOCK_MAGIC */ 32*4882a593Smuzhiyun uint64_t ub_version; /* ZFS_VERSION */ 33*4882a593Smuzhiyun uint64_t ub_txg; /* txg of last sync */ 34*4882a593Smuzhiyun uint64_t ub_guid_sum; /* sum of all vdev guids */ 35*4882a593Smuzhiyun uint64_t ub_timestamp; /* UTC time of last sync */ 36*4882a593Smuzhiyun blkptr_t ub_rootbp; /* MOS objset_phys_t */ 37*4882a593Smuzhiyun } uberblock_t; 38*4882a593Smuzhiyun 39*4882a593Smuzhiyun #define VDEV_UBERBLOCK_SHIFT(as) UBMAX(as, UBERBLOCK_SHIFT) 40*4882a593Smuzhiyun #define UBERBLOCK_SIZE(as) (1ULL << VDEV_UBERBLOCK_SHIFT(as)) 41*4882a593Smuzhiyun 42*4882a593Smuzhiyun /* Number of uberblocks that can fit in the ring at a given ashift */ 43*4882a593Smuzhiyun #define UBERBLOCK_COUNT(as) (VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(as)) 44*4882a593Smuzhiyun 45*4882a593Smuzhiyun #endif /* _SYS_UBERBLOCK_IMPL_H */ 46