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      1 /*
      2  *  GRUB  --  GRand Unified Bootloader
      3  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
      4  *
      5  *  This program is free software; you can redistribute it and/or modify
      6  *  it under the terms of the GNU General Public License as published by
      7  *  the Free Software Foundation; either version 2 of the License, or
      8  *  (at your option) any later version.
      9  *
     10  *  This program is distributed in the hope that it will be useful,
     11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
     12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13  *  GNU General Public License for more details.
     14  *
     15  *  You should have received a copy of the GNU General Public License
     16  *  along with this program; if not, write to the Free Software
     17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
     18  */
     19 /*
     20  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
     21  * Use is subject to license terms.
     22  */
     23 
     24 #ifndef	_SYS_ZIL_H
     25 #define	_SYS_ZIL_H
     26 
     27 /*
     28  * Intent log format:
     29  *
     30  * Each objset has its own intent log.  The log header (zil_header_t)
     31  * for objset N's intent log is kept in the Nth object of the SPA's
     32  * intent_log objset.  The log header points to a chain of log blocks,
     33  * each of which contains log records (i.e., transactions) followed by
     34  * a log block trailer (zil_trailer_t).  The format of a log record
     35  * depends on the record (or transaction) type, but all records begin
     36  * with a common structure that defines the type, length, and txg.
     37  */
     38 
     39 /*
     40  * Intent log header - this on disk structure holds fields to manage
     41  * the log.  All fields are 64 bit to easily handle cross architectures.
     42  */
     43 typedef struct zil_header {
     44 	uint64_t zh_claim_txg;	/* txg in which log blocks were claimed */
     45 	uint64_t zh_replay_seq;	/* highest replayed sequence number */
     46 	blkptr_t zh_log;	/* log chain */
     47 	uint64_t zh_claim_seq;	/* highest claimed sequence number */
     48 	uint64_t zh_flags;	/* header flags */
     49 	uint64_t zh_pad[4];
     50 } zil_header_t;
     51 
     52 /*
     53  * zh_flags bit settings
     54  */
     55 #define	ZIL_REPLAY_NEEDED 0x1	/* replay needed - internal only */
     56 
     57 #endif	/* _SYS_ZIL_H */
     58