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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2016, 2017 by Delphix. All rights reserved. 24 */ 25 26 #ifndef _SYS_UBERBLOCK_IMPL_H 27 #define _SYS_UBERBLOCK_IMPL_H 28 29 #include <sys/uberblock.h> 30 31 #ifdef __cplusplus 32 extern "C" { 33 #endif 34 35 /* 36 * The uberblock version is incremented whenever an incompatible on-disk 37 * format change is made to the SPA, DMU, or ZAP. 38 * 39 * Note: the first two fields should never be moved. When a storage pool 40 * is opened, the uberblock must be read off the disk before the version 41 * can be checked. If the ub_version field is moved, we may not detect 42 * version mismatch. If the ub_magic field is moved, applications that 43 * expect the magic number in the first word won't work. 44 */ 45 #define UBERBLOCK_MAGIC 0x00bab10c /* oo-ba-bloc! */ 46 #define UBERBLOCK_SHIFT 10 /* up to 1K */ 47 48 struct uberblock { 49 uint64_t ub_magic; /* UBERBLOCK_MAGIC */ 50 uint64_t ub_version; /* SPA_VERSION */ 51 uint64_t ub_txg; /* txg of last sync */ 52 uint64_t ub_guid_sum; /* sum of all vdev guids */ 53 uint64_t ub_timestamp; /* UTC time of last sync */ 54 blkptr_t ub_rootbp; /* MOS objset_phys_t */ 55 56 /* highest SPA_VERSION supported by software that wrote this txg */ 57 uint64_t ub_software_version; 58 59 /* These fields are reserved for features that are under development: */ 60 uint64_t ub_mmp_magic; 61 uint64_t ub_mmp_delay; 62 uint64_t ub_mmp_seq; 63 64 /* 65 * ub_checkpoint_txg indicates two things about the current uberblock: 66 * 67 * 1] If it is not zero then this uberblock is a checkpoint. If it is 68 * zero, then this uberblock is not a checkpoint. 69 * 70 * 2] On checkpointed uberblocks, the value of ub_checkpoint_txg is 71 * the ub_txg that the uberblock had at the time we moved it to 72 * the MOS config. 73 * 74 * The field is set when we checkpoint the uberblock and continues to 75 * hold that value even after we've rewound (unlike the ub_txg that 76 * is reset to a higher value). 77 * 78 * Besides checks used to determine whether we are reopening the 79 * pool from a checkpointed uberblock [see spa_ld_select_uberblock()], 80 * the value of the field is used to determine which ZIL blocks have 81 * been allocated according to the ms_sm when we are rewinding to a 82 * checkpoint. Specifically, if blk_birth > ub_checkpoint_txg, then 83 * the ZIL block is not allocated [see uses of spa_min_claim_txg()]. 84 */ 85 uint64_t ub_checkpoint_txg; 86 }; 87 88 #ifdef __cplusplus 89 } 90 #endif 91 92 #endif /* _SYS_UBERBLOCK_IMPL_H */ 93