MFV r322240: 8491 uberblock on-disk padding to reserve space for smoothly merging zpool checkpoint & MMP in ZFS

illumos/illumos-gate@79c2b812ee
79c2b812ee

https://www.illumos.org/issues/8491
  The zpool checkpoint feature in DxOS added a new field in the uberblock.
  The Multi-Modifier Protection Pull Request from ZoL adds two new fields in the
  uberblock (Reference: https://github.com/zfsonlinux/zfs/pull/6279).
  As these two changes come from two different sources and once upstreamed and
  deployed will introduce an incompatibility with each other we want
  to upstream a change that will reserve the padding for both of them so
  integration goes smoothly and everyone gets both features.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Olaf Faaland <faaland1@llnl.gov>
Approved by: Gordon Ross <gwr@nexenta.com>
Author: Serapheim Dimitropoulos <serapheim@delphix.com>

MFC after:	3 weeks
This commit is contained in:
Andriy Gapon 2017-08-08 11:21:58 +00:00
commit 2653426e89

View File

@ -20,6 +20,7 @@
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2017 by Delphix. All rights reserved.
*/
#ifndef _SYS_UBERBLOCK_IMPL_H
@ -54,6 +55,12 @@ struct uberblock {
/* highest SPA_VERSION supported by software that wrote this txg */
uint64_t ub_software_version;
/* These fields are reserved for features that are under development: */
uint64_t ub_mmp_magic;
uint64_t ub_mmp_delay;
uint64_t ub_mmp_seq;
uint64_t ub_checkpoint_txg;
};
#ifdef __cplusplus