dosfs.h revision 303975 
1/*
2 * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
3 * Copyright (c) 1995 Martin Husemann
4 * Some structure declaration borrowed from Paul Popelka
5 * (paulp@uts.amdahl.com), see /sys/msdosfs/ for reference.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *	$NetBSD: dosfs.h,v 1.4 1997/01/03 14:32:48 ws Exp $
27 * $FreeBSD: releng/11.0/sbin/fsck_msdosfs/dosfs.h 273865 2014-10-30 15:52:01Z ambrisko $
28 */
29
30#ifndef DOSFS_H
31#define DOSFS_H
32
33/* support 4Kn disk reads */
34#define DOSBOOTBLOCKSIZE_REAL 512
35#define DOSBOOTBLOCKSIZE 4096
36
37typedef	u_int32_t	cl_t;	/* type holding a cluster number */
38
39/*
40 * architecture independent description of all the info stored in a
41 * FAT boot block.
42 */
43struct bootblock {
44	u_int	bpbBytesPerSec;		/* bytes per sector */
45	u_int	bpbSecPerClust;		/* sectors per cluster */
46	u_int	bpbResSectors;		/* number of reserved sectors */
47	u_int	bpbFATs;		/* number of bpbFATs */
48	u_int	bpbRootDirEnts;		/* number of root directory entries */
49	u_int32_t bpbSectors;		/* total number of sectors */
50	u_int	bpbMedia;		/* media descriptor */
51	u_int	bpbFATsmall;		/* number of sectors per FAT */
52	u_int	SecPerTrack;		/* sectors per track */
53	u_int	bpbHeads;		/* number of heads */
54	u_int32_t bpbHiddenSecs;	/* # of hidden sectors */
55	u_int32_t bpbHugeSectors;	/* # of sectors if bpbbpbSectors == 0 */
56	cl_t	bpbRootClust;		/* Start of Root Directory */
57	u_int	bpbFSInfo;		/* FSInfo sector */
58	u_int	bpbBackup;		/* Backup of Bootblocks */
59	cl_t	FSFree;			/* Number of free clusters acc. FSInfo */
60	cl_t	FSNext;			/* Next free cluster acc. FSInfo */
61
62	/* and some more calculated values */
63	u_int	flags;			/* some flags: */
64#define	FAT32		1		/* this is a FAT32 file system */
65					/*
66					 * Maybe, we should separate out
67					 * various parts of FAT32?	XXX
68					 */
69	int	ValidFat;		/* valid fat if FAT32 non-mirrored */
70	cl_t	ClustMask;		/* mask for entries in FAT */
71	cl_t	NumClusters;		/* # of entries in a FAT */
72	u_int32_t NumSectors;		/* how many sectors are there */
73	u_int32_t FATsecs;		/* how many sectors are in FAT */
74	u_int32_t NumFatEntries;	/* how many entries really are there */
75	u_int	ClusterOffset;		/* at what sector would sector 0 start */
76	u_int	ClusterSize;		/* Cluster size in bytes */
77
78	/* Now some statistics: */
79	u_int	NumFiles;		/* # of plain files */
80	u_int	NumFree;		/* # of free clusters */
81	u_int	NumBad;			/* # of bad clusters */
82};
83
84struct fatEntry {
85	cl_t	next;			/* pointer to next cluster */
86	cl_t	head;			/* pointer to start of chain */
87	u_int32_t length;		/* number of clusters on chain */
88	int	flags;			/* see below */
89};
90
91#define	CLUST_FREE	0		/* 0 means cluster is free */
92#define	CLUST_FIRST	2		/* 2 is the minimum valid cluster number */
93#define	CLUST_RSRVD	0xfffffff6	/* start of reserved clusters */
94#define	CLUST_BAD	0xfffffff7	/* a cluster with a defect */
95#define	CLUST_EOFS	0xfffffff8	/* start of EOF indicators */
96#define	CLUST_EOF	0xffffffff	/* standard value for last cluster */
97
98/*
99 * Masks for cluster values
100 */
101#define	CLUST12_MASK	0xfff
102#define	CLUST16_MASK	0xffff
103#define	CLUST32_MASK	0xfffffff
104
105#define	FAT_USED	1		/* This fat chain is used in a file */
106
107#define	DOSLONGNAMELEN	256		/* long name maximal length */
108#define LRFIRST		0x40		/* first long name record */
109#define	LRNOMASK	0x1f		/* mask to extract long record
110					 * sequence number */
111
112/*
113 * Architecture independent description of a directory entry
114 */
115struct dosDirEntry {
116	struct dosDirEntry
117		*parent,		/* previous tree level */
118		*next,			/* next brother */
119		*child;			/* if this is a directory */
120	char name[8+1+3+1];		/* alias name first part */
121	char lname[DOSLONGNAMELEN];	/* real name */
122	uint flags;			/* attributes */
123	cl_t head;			/* cluster no */
124	u_int32_t size;			/* filesize in bytes */
125	uint fsckflags;			/* flags during fsck */
126};
127/* Flags in fsckflags: */
128#define	DIREMPTY	1
129#define	DIREMPWARN	2
130
131/*
132 *  TODO-list of unread directories
133 */
134struct dirTodoNode {
135	struct dosDirEntry *dir;
136	struct dirTodoNode *next;
137};
138
139#endif
140