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, see <http://www.gnu.org/licenses/>.
17  */
18 /*
19  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
20  * Use is subject to license terms.
21  */
22 
23 #ifndef	_SYS_DNODE_H
24 #define	_SYS_DNODE_H
25 
26 /*
27  * Fixed constants.
28  */
29 #define	DNODE_SHIFT		9	/* 512 bytes */
30 #define	DN_MIN_INDBLKSHIFT	10	/* 1k */
31 #define	DN_MAX_INDBLKSHIFT	14	/* 16k */
32 #define	DNODE_BLOCK_SHIFT	14	/* 16k */
33 #define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
34 #define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
35 #define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
36 
37 /*
38  * Derived constants.
39  */
40 #define	DNODE_SIZE	(1 << DNODE_SHIFT)
41 #define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
42 #define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
43 #define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
44 
45 #define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
46 #define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
47 #define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
48 
49 #define	DNODE_FLAG_SPILL_BLKPTR (1<<2)
50 
51 #define	DN_BONUS(dnp)	((void*)((dnp)->dn_bonus + \
52 	(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
53 
54 typedef struct dnode_phys {
55 	uint8_t dn_type;		/* dmu_object_type_t */
56 	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
57 	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
58 	uint8_t dn_nblkptr;		/* length of dn_blkptr */
59 	uint8_t dn_bonustype;		/* type of data in bonus buffer */
60 	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
61 	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
62 	uint8_t dn_flags;		/* DNODE_FLAG_* */
63 	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
64 	uint16_t dn_bonuslen;		/* length of dn_bonus */
65 	uint8_t dn_pad2[4];
66 
67 	/* accounting is protected by dn_dirty_mtx */
68 	uint64_t dn_maxblkid;		/* largest allocated block ID */
69 	uint64_t dn_used;		/* bytes (or sectors) of disk space */
70 
71 	uint64_t dn_pad3[4];
72 
73 	blkptr_t dn_blkptr[1];
74 	uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof (blkptr_t)];
75 	blkptr_t dn_spill;
76 } dnode_phys_t;
77 
78 #endif	/* _SYS_DNODE_H */
79