LXR uboot/include/zfs/uberblock

   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#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 */
  58