zfs/lib/libzpool/include/sys/uberblock_impl.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #ifndef _SYS_UBERBLOCK_IMPL_H
  27 #define _SYS_UBERBLOCK_IMPL_H
  28
  29 #pragma ident   "%Z%%M% %I%     %E% SMI"
  30
  31 #include <sys/uberblock.h>
  32
  33 #ifdef  __cplusplus
  34 extern "C" {
  35 #endif
  36
  37 /*
  38  * The uberblock version is incremented whenever an incompatible on-disk
  39  * format change is made to the SPA, DMU, or ZAP.
  40  *
  41  * Note: the first two fields should never be moved.  When a storage pool
  42  * is opened, the uberblock must be read off the disk before the version
  43  * can be checked.  If the ub_version field is moved, we may not detect
  44  * version mismatch.  If the ub_magic field is moved, applications that
  45  * expect the magic number in the first word won't work.
  46  */
  47 #define UBERBLOCK_MAGIC         0x00bab10c              /* oo-ba-bloc!  */
  48 #define UBERBLOCK_SHIFT         10                      /* up to 1K     */
  49
  50 struct uberblock {
  51         uint64_t        ub_magic;       /* UBERBLOCK_MAGIC              */
  52         uint64_t        ub_version;     /* SPA_VERSION                  */
  53         uint64_t        ub_txg;         /* txg of last sync             */
  54         uint64_t        ub_guid_sum;    /* sum of all vdev guids        */
  55         uint64_t        ub_timestamp;   /* UTC time of last sync        */
  56         blkptr_t        ub_rootbp;      /* MOS objset_phys_t            */
  57 };
  58
  59 #ifdef  __cplusplus
  60 }
  61 #endif
  62
  63 #endif  /* _SYS_UBERBLOCK_IMPL_H */