/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2016, 2017 by Delphix. All rights reserved.
 */

#ifndef _SYS_UBERBLOCK_IMPL_H
#define _SYS_UBERBLOCK_IMPL_H

#include <sys/uberblock.h>

#ifdef  __cplusplus
extern "C" {
#endif

/*
 * The uberblock version is incremented whenever an incompatible on-disk
 * format change is made to the SPA, DMU, or ZAP.
 *
 * Note: the first two fields should never be moved.  When a storage pool
 * is opened, the uberblock must be read off the disk before the version
 * can be checked.  If the ub_version field is moved, we may not detect
 * version mismatch.  If the ub_magic field is moved, applications that
 * expect the magic number in the first word won't work.
 */
#define UBERBLOCK_MAGIC         0x00bab10c              /* oo-ba-bloc!  */
#define UBERBLOCK_SHIFT         10                      /* up to 1K     */
#define MMP_MAGIC               0xa11cea11              /* all-see-all  */

#define MMP_INTERVAL_VALID_BIT  0x01
#define MMP_SEQ_VALID_BIT       0x02
#define MMP_FAIL_INT_VALID_BIT  0x04

#define MMP_VALID(ubp)          (ubp->ub_magic == UBERBLOCK_MAGIC && \
                                    ubp->ub_mmp_magic == MMP_MAGIC)
#define MMP_INTERVAL_VALID(ubp) (MMP_VALID(ubp) && (ubp->ub_mmp_config & \
                                    MMP_INTERVAL_VALID_BIT))
#define MMP_SEQ_VALID(ubp)      (MMP_VALID(ubp) && (ubp->ub_mmp_config & \
                                    MMP_SEQ_VALID_BIT))
#define MMP_FAIL_INT_VALID(ubp) (MMP_VALID(ubp) && (ubp->ub_mmp_config & \
                                    MMP_FAIL_INT_VALID_BIT))

#define MMP_INTERVAL(ubp)       ((ubp->ub_mmp_config & 0x00000000FFFFFF00) \
                                    >> 8)
#define MMP_SEQ(ubp)            ((ubp->ub_mmp_config & 0x0000FFFF00000000) \
                                    >> 32)
#define MMP_FAIL_INT(ubp)       ((ubp->ub_mmp_config & 0xFFFF000000000000) \
                                    >> 48)

#define MMP_INTERVAL_SET(write) \
            (((uint64_t)(write & 0xFFFFFF) << 8) | MMP_INTERVAL_VALID_BIT)

#define MMP_SEQ_SET(seq) \
            (((uint64_t)(seq & 0xFFFF) << 32) | MMP_SEQ_VALID_BIT)

#define MMP_FAIL_INT_SET(fail) \
            (((uint64_t)(fail & 0xFFFF) << 48) | MMP_FAIL_INT_VALID_BIT)

struct uberblock {
        uint64_t        ub_magic;       /* UBERBLOCK_MAGIC              */
        uint64_t        ub_version;     /* SPA_VERSION                  */
        uint64_t        ub_txg;         /* txg of last sync             */
        uint64_t        ub_guid_sum;    /* sum of all vdev guids        */
        uint64_t        ub_timestamp;   /* UTC time of last sync        */
        blkptr_t        ub_rootbp;      /* MOS objset_phys_t            */

        /* highest SPA_VERSION supported by software that wrote this txg */
        uint64_t        ub_software_version;

        /* Maybe missing in uberblocks we read, but always written */
        uint64_t        ub_mmp_magic;
        /*
         * If ub_mmp_delay == 0 and ub_mmp_magic is valid, MMP is off.
         * Otherwise, nanosec since last MMP write.
         */
        uint64_t        ub_mmp_delay;

        /*
         * The ub_mmp_config contains the multihost write interval, multihost
         * fail intervals, sequence number for sub-second granularity, and
         * valid bit mask.  This layout is as follows:
         *
         *   64      56      48      40      32      24      16      8       0
         *   +-------+-------+-------+-------+-------+-------+-------+-------+
         * 0 | Fail Intervals|      Seq      |   Write Interval (ms) | VALID |
         *   +-------+-------+-------+-------+-------+-------+-------+-------+
         *
         * This allows a write_interval of (2^24/1000)s, over 4.5 hours
         *
         * VALID Bits:
         * - 0x01 - Write Interval (ms)
         * - 0x02 - Sequence number exists
         * - 0x04 - Fail Intervals
         * - 0xf8 - Reserved
         */
        uint64_t        ub_mmp_config;

        /*
         * ub_checkpoint_txg indicates two things about the current uberblock:
         *
         * 1] If it is not zero then this uberblock is a checkpoint. If it is
         *    zero, then this uberblock is not a checkpoint.
         *
         * 2] On checkpointed uberblocks, the value of ub_checkpoint_txg is
         *    the ub_txg that the uberblock had at the time we moved it to
         *    the MOS config.
         *
         * The field is set when we checkpoint the uberblock and continues to
         * hold that value even after we've rewound (unlike the ub_txg that
         * is reset to a higher value).
         *
         * Besides checks used to determine whether we are reopening the
         * pool from a checkpointed uberblock [see spa_ld_select_uberblock()],
         * the value of the field is used to determine which ZIL blocks have
         * been allocated according to the ms_sm when we are rewinding to a
         * checkpoint. Specifically, if blk_birth > ub_checkpoint_txg, then
         * the ZIL block is not allocated [see uses of spa_min_claim_txg()].
         */
        uint64_t        ub_checkpoint_txg;
};

#ifdef  __cplusplus
}
#endif

#endif  /* _SYS_UBERBLOCK_IMPL_H */