zil.h

xen 3.2.2 源码

/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef	_SYS_ZIL_H
#define	_SYS_ZIL_H

/*
 * Intent log format:
 *
 * Each objset has its own intent log.  The log header (zil_header_t)
 * for objset N's intent log is kept in the Nth object of the SPA's
 * intent_log objset.  The log header points to a chain of log blocks,
 * each of which contains log records (i.e., transactions) followed by
 * a log block trailer (zil_trailer_t).  The format of a log record
 * depends on the record (or transaction) type, but all records begin
 * with a common structure that defines the type, length, and txg.
 */

/*
 * Intent log header - this on disk structure holds fields to manage
 * the log.  All fields are 64 bit to easily handle cross architectures.
 */
typedef struct zil_header {
	uint64_t zh_claim_txg;	/* txg in which log blocks were claimed */
	uint64_t zh_replay_seq;	/* highest replayed sequence number */
	blkptr_t zh_log;	/* log chain */
	uint64_t zh_claim_seq;	/* highest claimed sequence number */
	uint64_t zh_pad[5];
} zil_header_t;

#endif	/* _SYS_ZIL_H */