include/zfs/zil.h

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7 /*
   8  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   9  * Use is subject to license terms.
  10  */
  11
  12 #ifndef _SYS_ZIL_H
  13 #define _SYS_ZIL_H
  14
  15 /*
  16  * Intent log format:
  17  *
  18  * Each objset has its own intent log.  The log header (zil_header_t)
  19  * for objset N's intent log is kept in the Nth object of the SPA's
  20  * intent_log objset.  The log header points to a chain of log blocks,
  21  * each of which contains log records (i.e., transactions) followed by
  22  * a log block trailer (zil_trailer_t).  The format of a log record
  23  * depends on the record (or transaction) type, but all records begin
  24  * with a common structure that defines the type, length, and txg.
  25  */
  26
  27 /*
  28  * Intent log header - this on disk structure holds fields to manage
  29  * the log.  All fields are 64 bit to easily handle cross architectures.
  30  */
  31 typedef struct zil_header {
  32         uint64_t zh_claim_txg;   /* txg in which log blocks were claimed */
  33         uint64_t zh_replay_seq;  /* highest replayed sequence number */
  34         blkptr_t zh_log;        /* log chain */
  35         uint64_t zh_claim_seq;  /* highest claimed sequence number */
  36         uint64_t zh_flags;      /* header flags */
  37         uint64_t zh_pad[4];
  38 } zil_header_t;
  39
  40 /*
  41  * zh_flags bit settings
  42  */
  43 #define ZIL_REPLAY_NEEDED 0x1   /* replay needed - internal only */
  44
  45 #endif  /* _SYS_ZIL_H */