module/zfs/uberblock.c

   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 https://opensource.org/licenses/CDDL-1.0.
  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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2013, 2017 by Delphix. All rights reserved.
  24  */
  25
  26 #include <sys/zfs_context.h>
  27 #include <sys/uberblock_impl.h>
  28 #include <sys/vdev_impl.h>
  29 #include <sys/mmp.h>
  30
  31 int
  32 uberblock_verify(uberblock_t *ub)
  33 {
  34         if (ub->ub_magic == BSWAP_64((uint64_t)UBERBLOCK_MAGIC))
  35                 byteswap_uint64_array(ub, sizeof (uberblock_t));
  36
  37         if (ub->ub_magic != UBERBLOCK_MAGIC)
  38                 return (SET_ERROR(EINVAL));
  39
  40         return (0);
  41 }
  42
  43 /*
  44  * Update the uberblock and return TRUE if anything changed in this
  45  * transaction group.
  46  */
  47 boolean_t
  48 uberblock_update(uberblock_t *ub, vdev_t *rvd, uint64_t txg, uint64_t mmp_delay)
  49 {
  50         ASSERT(ub->ub_txg < txg);
  51
  52         /*
  53          * We explicitly do not set ub_version here, so that older versions
  54          * continue to be written with the previous uberblock version.
  55          */
  56         ub->ub_magic = UBERBLOCK_MAGIC;
  57         ub->ub_txg = txg;
  58         ub->ub_guid_sum = rvd->vdev_guid_sum;
  59         ub->ub_timestamp = gethrestime_sec();
  60         ub->ub_software_version = SPA_VERSION;
  61         ub->ub_mmp_magic = MMP_MAGIC;
  62         if (spa_multihost(rvd->vdev_spa)) {
  63                 ub->ub_mmp_delay = mmp_delay;
  64                 ub->ub_mmp_config = MMP_SEQ_SET(0) |
  65                     MMP_INTERVAL_SET(zfs_multihost_interval) |
  66                     MMP_FAIL_INT_SET(zfs_multihost_fail_intervals);
  67         } else {
  68                 ub->ub_mmp_delay = 0;
  69                 ub->ub_mmp_config = 0;
  70         }
  71         ub->ub_checkpoint_txg = 0;
  72
  73         return (ub->ub_rootbp.blk_birth == txg);
  74 }