zfs-builds-mm/zfs-0.8.2/include/sys/uberblock_impl.h

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2019-10-24 23:13:56 +02:00
/*
* 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; /* 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 */