xref: /openbmc/u-boot/include/zfs/zil.h (revision c6af2e7d)
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