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 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) 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 #define MMP_MAGIC               0xa11cea11              /* all-see-all  */
  48
  49 #define MMP_INTERVAL_VALID_BIT  0x01
  50 #define MMP_SEQ_VALID_BIT       0x02
  51 #define MMP_FAIL_INT_VALID_BIT  0x04
  52
  53 #define MMP_VALID(ubp)          (ubp->ub_magic == UBERBLOCK_MAGIC && \
  54                                     ubp->ub_mmp_magic == MMP_MAGIC)
  55 #define MMP_INTERVAL_VALID(ubp) (MMP_VALID(ubp) && (ubp->ub_mmp_config & \
  56                                     MMP_INTERVAL_VALID_BIT))
  57 #define MMP_SEQ_VALID(ubp)      (MMP_VALID(ubp) && (ubp->ub_mmp_config & \
  58                                     MMP_SEQ_VALID_BIT))
  59 #define MMP_FAIL_INT_VALID(ubp) (MMP_VALID(ubp) && (ubp->ub_mmp_config & \
  60                                     MMP_FAIL_INT_VALID_BIT))
  61
  62 #define MMP_INTERVAL(ubp)       ((ubp->ub_mmp_config & 0x00000000FFFFFF00) \
  63                                     >> 8)
  64 #define MMP_SEQ(ubp)            ((ubp->ub_mmp_config & 0x0000FFFF00000000) \
  65                                     >> 32)
  66 #define MMP_FAIL_INT(ubp)       ((ubp->ub_mmp_config & 0xFFFF000000000000) \
  67                                     >> 48)
  68
  69 #define MMP_INTERVAL_SET(write) \
  70             (((uint64_t)(write & 0xFFFFFF) << 8) | MMP_INTERVAL_VALID_BIT)
  71
  72 #define MMP_SEQ_SET(seq) \
  73             (((uint64_t)(seq & 0xFFFF) << 32) | MMP_SEQ_VALID_BIT)
  74
  75 #define MMP_FAIL_INT_SET(fail) \
  76             (((uint64_t)(fail & 0xFFFF) << 48) | MMP_FAIL_INT_VALID_BIT)
  77
  78 struct uberblock {
  79         uint64_t        ub_magic;       /* UBERBLOCK_MAGIC              */
  80         uint64_t        ub_version;     /* SPA_VERSION                  */
  81         uint64_t        ub_txg;         /* txg of last sync             */
  82         uint64_t        ub_guid_sum;    /* sum of all vdev guids        */
  83         uint64_t        ub_timestamp;   /* UTC time of last sync        */
  84         blkptr_t        ub_rootbp;      /* MOS objset_phys_t            */
  85
  86         /* highest SPA_VERSION supported by software that wrote this txg */
  87         uint64_t        ub_software_version;
  88
  89         /* Maybe missing in uberblocks we read, but always written */
  90         uint64_t        ub_mmp_magic;   /* MMP_MAGIC                    */
  91         /*
  92          * If ub_mmp_delay == 0 and ub_mmp_magic is valid, MMP is off.
  93          * Otherwise, nanosec since last MMP write.
  94          */
  95         uint64_t        ub_mmp_delay;
  96
  97         /*
  98          * The ub_mmp_config contains the multihost write interval, multihost
  99          * fail intervals, sequence number for sub-second granularity, and
 100          * valid bit mask.  This layout is as follows:
 101          *
 102          *   64      56      48      40      32      24      16      8       0
 103          *   +-------+-------+-------+-------+-------+-------+-------+-------+
 104          * 0 | Fail Intervals|      Seq      |   Write Interval (ms) | VALID |
 105          *   +-------+-------+-------+-------+-------+-------+-------+-------+
 106          *
 107          * This allows a write_interval of (2^24/1000)s, over 4.5 hours
 108          *
 109          * VALID Bits:
 110          * - 0x01 - Write Interval (ms)
 111          * - 0x02 - Sequence number exists
 112          * - 0x04 - Fail Intervals
 113          * - 0xf8 - Reserved
 114          */
 115         uint64_t        ub_mmp_config;
 116
 117         /*
 118          * ub_checkpoint_txg indicates two things about the current uberblock:
 119          *
 120          * 1] If it is not zero then this uberblock is a checkpoint. If it is
 121          *    zero, then this uberblock is not a checkpoint.
 122          *
 123          * 2] On checkpointed uberblocks, the value of ub_checkpoint_txg is
 124          *    the ub_txg that the uberblock had at the time we moved it to
 125          *    the MOS config.
 126          *
 127          * The field is set when we checkpoint the uberblock and continues to
 128          * hold that value even after we've rewound (unlike the ub_txg that
 129          * is reset to a higher value).
 130          *
 131          * Besides checks used to determine whether we are reopening the
 132          * pool from a checkpointed uberblock [see spa_ld_select_uberblock()],
 133          * the value of the field is used to determine which ZIL blocks have
 134          * been allocated according to the ms_sm when we are rewinding to a
 135          * checkpoint. Specifically, if blk_birth > ub_checkpoint_txg, then
 136          * the ZIL block is not allocated [see uses of spa_min_claim_txg()].
 137          */
 138         uint64_t        ub_checkpoint_txg;
 139 };
 140
 141 #ifdef  __cplusplus
 142 }
 143 #endif
 144
 145 #endif  /* _SYS_UBERBLOCK_IMPL_H */