minix/sys/fs/msdosfs/fat.h

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/* $NetBSD: fat.h,v 1.8 2013/01/26 00:21:49 christos Exp $ */
/*-
* Copyright (C) 1994, 1997 Wolfgang Solfrank.
* Copyright (C) 1994, 1997 TooLs GmbH.
* All rights reserved.
* Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*/
#ifndef _MSDOSFS_FAT_H_
#define _MSDOSFS_FAT_H_
/*
* Some useful cluster numbers.
*/
#define MSDOSFSROOT 0 /* cluster 0 means the root dir */
#define CLUST_FREE 0 /* cluster 0 also means a free cluster */
#define MSDOSFSFREE CLUST_FREE
#define CLUST_FIRST 2 /* first legal cluster number */
#define CLUST_RSRVD 0xfffffff6 /* reserved cluster range */
#define CLUST_BAD 0xfffffff7 /* a cluster with a defect */
#define CLUST_EOFS 0xfffffff8 /* start of eof cluster range */
#define CLUST_EOFE 0xffffffff /* end of eof cluster range */
#define CLUST_END CLUST_EOFE /* bigger than any valid cluster */
#define FAT12_MASK 0x00000fff /* mask for 12 bit cluster numbers */
#define FAT16_MASK 0x0000ffff /* mask for 16 bit cluster numbers */
#define FAT32_MASK 0x0fffffff /* mask for FAT32 cluster numbers */
/*
* MSDOSFS:
* Return true if filesystem uses 12 bit FATs. Microsoft Programmer's
* Reference says if the maximum cluster number in a filesystem is greater
* than 4084 ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK) then we've got a
* 16 bit FAT filesystem. While mounting, the result of this test is stored
* in pm_fatentrysize.
* GEMDOS-flavour (atari):
* If the filesystem is on floppy we've got a 12 bit FAT filesystem, otherwise
* 16 bit. We check the d_type field in the disklabel struct while mounting
* and store the result in the pm_fatentrysize. Note that this kind of
* detection gets flakey when mounting a vnd-device.
*/
#define FAT12(pmp) (pmp->pm_fatmask == FAT12_MASK)
#define FAT16(pmp) (pmp->pm_fatmask == FAT16_MASK)
#define FAT32(pmp) (pmp->pm_fatmask == FAT32_MASK)
/*
* M$ in it's unlimited wisdom desided that EOF mark is anything
* between 0xfffffff8 and 0xffffffff (masked by appropriate fatmask,
* of course).
* Note that cn is supposed to be already adjusted accordingly to FAT type.
*/
#define MSDOSFSEOF(cn, fatmask) \
(((cn) & CLUST_EOFS) == (CLUST_EOFS & (fatmask)))
#if defined(_KERNEL) || defined(MAKEFS)
/*
* These are the values for the function argument to the function
* fatentry().
*/
#define FAT_GET 0x0001 /* get a FAT entry */
#define FAT_SET 0x0002 /* set a FAT entry */
#define FAT_GET_AND_SET (FAT_GET | FAT_SET)
/*
* Flags to extendfile:
*/
#define DE_CLEAR 1 /* Zero out the blocks allocated */
int pcbmap(struct denode *, u_long, daddr_t *, u_long *, int *);
int clusterfree(struct msdosfsmount *, u_long, u_long *);
int clusteralloc(struct msdosfsmount *, u_long, u_long,u_long *,u_long *);
int extendfile(struct denode *, u_long, struct buf **, u_long *, int);
int fatentry(int, struct msdosfsmount *, u_long, u_long *, u_long);
void fc_purge(struct denode *, u_int);
void fc_lookup(struct denode *, u_long, u_long *, u_long *);
int fillinusemap(struct msdosfsmount *);
int freeclusterchain(struct msdosfsmount *, u_long);
#endif /* _KERNEL || MAKEFS */
#endif /* _MSDOSFS_FAT_H_ */