FreeBSD/Linux Kernel Cross Reference
sys/msdosfs/fat.h
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 /*
52 * Some useful cluster numbers.
53 */
54 #define MSDOSFSROOT 0 /* cluster 0 means the root dir */
55 #define CLUST_FREE 0 /* cluster 0 also means a free cluster */
56 #define MSDOSFSFREE CLUST_FREE
57 #define CLUST_FIRST 2 /* first legal cluster number */
58 #define CLUST_RSRVD 0xfffffff6 /* reserved cluster range */
59 #define CLUST_BAD 0xfffffff7 /* a cluster with a defect */
60 #define CLUST_EOFS 0xfffffff8 /* start of eof cluster range */
61 #define CLUST_EOFE 0xffffffff /* end of eof cluster range */
62
63 #define FAT12_MASK 0x00000fff /* mask for 12 bit cluster numbers */
64 #define FAT16_MASK 0x0000ffff /* mask for 16 bit cluster numbers */
65 #define FAT32_MASK 0x0fffffff /* mask for FAT32 cluster numbers */
66
67 /*
68 * MSDOSFS:
69 * Return true if filesystem uses 12 bit fats. Microsoft Programmer's
70 * Reference says if the maximum cluster number in a filesystem is greater
71 * than 4078 ((CLUST_RSRVS - CLUST_FIRST) & FAT12_MASK) then we've got a
72 * 16 bit fat filesystem. While mounting, the result of this test is stored
73 * in pm_fatentrysize.
74 * GEMDOS-flavour (atari):
75 * If the filesystem is on floppy we've got a 12 bit fat filesystem, otherwise
76 * 16 bit. We check the d_type field in the disklabel struct while mounting
77 * and store the result in the pm_fatentrysize. Note that this kind of
78 * detection gets flakey when mounting a vnd-device.
79 */
80 #define FAT12(pmp) (pmp->pm_fatmask == FAT12_MASK)
81 #define FAT16(pmp) (pmp->pm_fatmask == FAT16_MASK)
82 #define FAT32(pmp) (pmp->pm_fatmask == FAT32_MASK)
83
84 #define MSDOSFSEOF(pmp, cn) ((((cn) | ~(pmp)->pm_fatmask) & CLUST_EOFS) == CLUST_EOFS)
85
86 #ifdef _KERNEL
87 /*
88 * These are the values for the function argument to the function
89 * fatentry().
90 */
91 #define FAT_GET 0x0001 /* get a fat entry */
92 #define FAT_SET 0x0002 /* set a fat entry */
93 #define FAT_GET_AND_SET (FAT_GET | FAT_SET)
94
95 /*
96 * Flags to extendfile:
97 */
98 #define DE_CLEAR 1 /* Zero out the blocks allocated */
99
100 int pcbmap __P((struct denode *dep, u_long findcn, daddr_t *bnp, u_long *cnp, int* sp));
101 int clusterfree __P((struct msdosfsmount *pmp, u_long cn, u_long *oldcnp));
102 int clusteralloc __P((struct msdosfsmount *pmp, u_long start, u_long count, u_long fillwith, u_long *retcluster, u_long *got));
103 int fatentry __P((int function, struct msdosfsmount *pmp, u_long cluster, u_long *oldcontents, u_long newcontents));
104 int freeclusterchain __P((struct msdosfsmount *pmp, u_long startchain));
105 int extendfile __P((struct denode *dep, u_long count, struct buf **bpp, u_long *ncp, int flags));
106 void fc_purge __P((struct denode *dep, u_int frcn));
107
108 #endif /* _KERNEL */
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