xref: /freebsd/sys/fs/msdosfs/fat.h (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /* $FreeBSD$ */
2 /*	$NetBSD: fat.h,v 1.12 1997/11/17 15:36:36 ws Exp $	*/
3 
4 /*-
5  * Copyright (C) 1994, 1997 Wolfgang Solfrank.
6  * Copyright (C) 1994, 1997 TooLs GmbH.
7  * All rights reserved.
8  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by TooLs GmbH.
21  * 4. The name of TooLs GmbH may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 /*-
36  * Written by Paul Popelka (paulp@uts.amdahl.com)
37  *
38  * You can do anything you want with this software, just don't say you wrote
39  * it, and don't remove this notice.
40  *
41  * This software is provided "as is".
42  *
43  * The author supplies this software to be publicly redistributed on the
44  * understanding that the author is not responsible for the correct
45  * functioning of this software in any circumstances and is not liable for
46  * any damages caused by this software.
47  *
48  * October 1992
49  */
50 
51 #ifndef _FS_MSDOSFS_FAT_H_
52 #define	_FS_MSDOSFS_FAT_H_
53 /*
54  * Some useful cluster numbers.
55  */
56 #define	MSDOSFSROOT	0		/* cluster 0 means the root dir */
57 #define	CLUST_FREE	0		/* cluster 0 also means a free cluster */
58 #define	MSDOSFSFREE	CLUST_FREE
59 #define	CLUST_FIRST	2		/* first legal cluster number */
60 #define	CLUST_RSRVD	0xfffffff6	/* reserved cluster range */
61 #define	CLUST_BAD	0xfffffff7	/* a cluster with a defect */
62 #define	CLUST_EOFS	0xfffffff8	/* start of eof cluster range */
63 #define	CLUST_EOFE	0xffffffff	/* end of eof cluster range */
64 
65 #define	FAT12_MASK	0x00000fff	/* mask for 12 bit cluster numbers */
66 #define	FAT16_MASK	0x0000ffff	/* mask for 16 bit cluster numbers */
67 #define	FAT32_MASK	0x0fffffff	/* mask for FAT32 cluster numbers */
68 
69 /*
70  * MSDOSFS:
71  * Return true if filesystem uses 12 bit FATs. Microsoft Programmer's
72  * Reference says if the maximum cluster number in a filesystem is greater
73  * than 4084 ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK) then we've got a
74  * 16 bit FAT filesystem. While mounting, the result of this test is stored
75  * in pm_fatentrysize.
76  */
77 #define	FAT12(pmp)	(pmp->pm_fatmask == FAT12_MASK)
78 #define	FAT16(pmp)	(pmp->pm_fatmask == FAT16_MASK)
79 #define	FAT32(pmp)	(pmp->pm_fatmask == FAT32_MASK)
80 
81 #define	MSDOSFSEOF(pmp, cn)	((((cn) | ~(pmp)->pm_fatmask) & CLUST_EOFS) == CLUST_EOFS)
82 
83 #if defined(_KERNEL) || defined(MAKEFS)
84 /*
85  * These are the values for the function argument to the function
86  * fatentry().
87  */
88 #define	FAT_GET		0x0001	/* get a FAT entry */
89 #define	FAT_SET		0x0002	/* set a FAT entry */
90 #define	FAT_GET_AND_SET	(FAT_GET | FAT_SET)
91 
92 /*
93  * Flags to extendfile:
94  */
95 #define	DE_CLEAR	1	/* Zero out the blocks allocated */
96 
97 int pcbmap(struct denode *dep, u_long findcn, daddr_t *bnp, u_long *cnp, int* sp);
98 int clusterfree(struct msdosfsmount *pmp, u_long cn, u_long *oldcnp);
99 int clusteralloc(struct msdosfsmount *pmp, u_long start, u_long count, u_long fillwith, u_long *retcluster, u_long *got);
100 int fatentry(int function, struct msdosfsmount *pmp, u_long cluster, u_long *oldcontents, u_long newcontents);
101 int freeclusterchain(struct msdosfsmount *pmp, u_long startchain);
102 int extendfile(struct denode *dep, u_long count, struct buf **bpp, u_long *ncp, int flags);
103 void fc_purge(struct denode *dep, u_int frcn);
104 int markvoldirty(struct msdosfsmount *pmp, int dirty);
105 
106 #endif	/* _KERNEL || MAKEFS */
107 #endif	/* !_FS_MSDOSFS_FAT_H_ */
108