1/* $FreeBSD$ */
2/*	$NetBSD: fat.h,v 1.12 1997/11/17 15:36:36 ws Exp $	*/
3
4/*-
5 * SPDX-License-Identifier: BSD-4-Clause
6 *
7 * Copyright (C) 1994, 1997 Wolfgang Solfrank.
8 * Copyright (C) 1994, 1997 TooLs GmbH.
9 * All rights reserved.
10 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 *    must display the following acknowledgement:
22 *	This product includes software developed by TooLs GmbH.
23 * 4. The name of TooLs GmbH may not be used to endorse or promote products
24 *    derived from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
32 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
33 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
34 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
35 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
37/*-
38 * Written by Paul Popelka (paulp@uts.amdahl.com)
39 *
40 * You can do anything you want with this software, just don't say you wrote
41 * it, and don't remove this notice.
42 *
43 * This software is provided "as is".
44 *
45 * The author supplies this software to be publicly redistributed on the
46 * understanding that the author is not responsible for the correct
47 * functioning of this software in any circumstances and is not liable for
48 * any damages caused by this software.
49 *
50 * October 1992
51 */
52
53#ifndef _FS_MSDOSFS_FAT_H_
54#define	_FS_MSDOSFS_FAT_H_
55/*
56 * Some useful cluster numbers.
57 */
58#define	MSDOSFSROOT	0		/* cluster 0 means the root dir */
59#define	CLUST_FREE	0		/* cluster 0 also means a free cluster */
60#define	MSDOSFSFREE	CLUST_FREE
61#define	CLUST_FIRST	2		/* first legal cluster number */
62#define	CLUST_RSRVD	0xfffffff6	/* reserved cluster range */
63#define	CLUST_BAD	0xfffffff7	/* a cluster with a defect */
64#define	CLUST_EOFS	0xfffffff8	/* start of eof cluster range */
65#define	CLUST_EOFE	0xffffffff	/* end of eof cluster range */
66
67#define	FAT12_MASK	0x00000fff	/* mask for 12 bit cluster numbers */
68#define	FAT16_MASK	0x0000ffff	/* mask for 16 bit cluster numbers */
69#define	FAT32_MASK	0x0fffffff	/* mask for FAT32 cluster numbers */
70
71/*
72 * MSDOSFS:
73 * Return true if filesystem uses 12 bit FATs. Microsoft Programmer's
74 * Reference says if the maximum cluster number in a filesystem is greater
75 * than 4084 ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK) then we've got a
76 * 16 bit FAT filesystem. While mounting, the result of this test is stored
77 * in pm_fatentrysize.
78 */
79#define	FAT12(pmp)	(pmp->pm_fatmask == FAT12_MASK)
80#define	FAT16(pmp)	(pmp->pm_fatmask == FAT16_MASK)
81#define	FAT32(pmp)	(pmp->pm_fatmask == FAT32_MASK)
82
83#define	MSDOSFSEOF(pmp, cn)	((((cn) | ~(pmp)->pm_fatmask) & CLUST_EOFS) == CLUST_EOFS)
84
85/*
86 * These are the values for the function argument to the function
87 * fatentry().
88 */
89#define	FAT_GET		0x0001	/* get a FAT entry */
90#define	FAT_SET		0x0002	/* set a FAT entry */
91#define	FAT_GET_AND_SET	(FAT_GET | FAT_SET)
92
93/*
94 * Flags to extendfile:
95 */
96#define	DE_CLEAR	1	/* Zero out the blocks allocated */
97
98struct buf;
99struct denode;
100struct msdosfsmount;
101
102int pcbmap(struct denode *dep, u_long findcn, daddr_t *bnp, u_long *cnp, int* sp);
103int clusterfree(struct msdosfsmount *pmp, u_long cn, u_long *oldcnp);
104int clusteralloc(struct msdosfsmount *pmp, u_long start, u_long count, u_long fillwith, u_long *retcluster, u_long *got);
105int fatentry(int function, struct msdosfsmount *pmp, u_long cluster, u_long *oldcontents, u_long newcontents);
106int freeclusterchain(struct msdosfsmount *pmp, u_long startchain);
107int extendfile(struct denode *dep, u_long count, struct buf **bpp, u_long *ncp, int flags);
108void fc_purge(struct denode *dep, u_int frcn);
109
110#endif	/* !_FS_MSDOSFS_FAT_H_ */
111