sys/vfs/msdosfs/fat.h

   1 /* $FreeBSD: src/sys/msdosfs/fat.h,v 1.9 1999/12/29 04:54:53 peter Exp $ */
   2 /* $DragonFly: src/sys/vfs/msdosfs/fat.h,v 1.3 2003/08/20 09:56:32 rob Exp $ */
   3 /*      $NetBSD: fat.h,v 1.12 1997/11/17 15:36:36 ws Exp $      */
   4
   5 /*-
   6  * Copyright (C) 1994, 1997 Wolfgang Solfrank.
   7  * Copyright (C) 1994, 1997 TooLs GmbH.
   8  * All rights reserved.
   9  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *      This product includes software developed by TooLs GmbH.
  22  * 4. The name of TooLs GmbH may not be used to endorse or promote products
  23  *    derived from this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
  26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  28  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  31  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  32  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  33  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  34  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  */
  36 /*
  37  * Written by Paul Popelka (paulp@uts.amdahl.com)
  38  *
  39  * You can do anything you want with this software, just don't say you wrote
  40  * it, and don't remove this notice.
  41  *
  42  * This software is provided "as is".
  43  *
  44  * The author supplies this software to be publicly redistributed on the
  45  * understanding that the author is not responsible for the correct
  46  * functioning of this software in any circumstances and is not liable for
  47  * any damages caused by this software.
  48  *
  49  * October 1992
  50  */
  51
  52 /*
  53  * Some useful cluster numbers.
  54  */
  55 #define MSDOSFSROOT     0               /* cluster 0 means the root dir */
  56 #define CLUST_FREE      0               /* cluster 0 also means a free cluster */
  57 #define MSDOSFSFREE     CLUST_FREE
  58 #define CLUST_FIRST     2               /* first legal cluster number */
  59 #define CLUST_RSRVD     0xfffffff6      /* reserved cluster range */
  60 #define CLUST_BAD       0xfffffff7      /* a cluster with a defect */
  61 #define CLUST_EOFS      0xfffffff8      /* start of eof cluster range */
  62 #define CLUST_EOFE      0xffffffff      /* end of eof cluster range */
  63
  64 #define FAT12_MASK      0x00000fff      /* mask for 12 bit cluster numbers */
  65 #define FAT16_MASK      0x0000ffff      /* mask for 16 bit cluster numbers */
  66 #define FAT32_MASK      0x0fffffff      /* mask for FAT32 cluster numbers */
  67
  68 /*
  69  * MSDOSFS:
  70  * Return true if filesystem uses 12 bit fats. Microsoft Programmer's
  71  * Reference says if the maximum cluster number in a filesystem is greater
  72  * than 4078 ((CLUST_RSRVS - CLUST_FIRST) & FAT12_MASK) then we've got a
  73  * 16 bit fat filesystem. While mounting, the result of this test is stored
  74  * in pm_fatentrysize.
  75  * GEMDOS-flavour (atari):
  76  * If the filesystem is on floppy we've got a 12 bit fat filesystem, otherwise
  77  * 16 bit. We check the d_type field in the disklabel struct while mounting
  78  * and store the result in the pm_fatentrysize. Note that this kind of
  79  * detection gets flakey when mounting a vnd-device.
  80  */
  81 #define FAT12(pmp)      (pmp->pm_fatmask == FAT12_MASK)
  82 #define FAT16(pmp)      (pmp->pm_fatmask == FAT16_MASK)
  83 #define FAT32(pmp)      (pmp->pm_fatmask == FAT32_MASK)
  84
  85 #define MSDOSFSEOF(pmp, cn)     ((((cn) | ~(pmp)->pm_fatmask) & CLUST_EOFS) == CLUST_EOFS)
  86
  87 #ifdef _KERNEL
  88 /*
  89  * These are the values for the function argument to the function
  90  * fatentry().
  91  */
  92 #define FAT_GET         0x0001  /* get a fat entry */
  93 #define FAT_SET         0x0002  /* set a fat entry */
  94 #define FAT_GET_AND_SET (FAT_GET | FAT_SET)
  95
  96 /*
  97  * Flags to extendfile:
  98  */
  99 #define DE_CLEAR        1       /* Zero out the blocks allocated */
 100
 101 int pcbmap (struct denode *dep, u_long findcn, daddr_t *bnp, u_long *cnp, int* sp);
 102 int clusterfree (struct msdosfsmount *pmp, u_long cn, u_long *oldcnp);
 103 int clusteralloc (struct msdosfsmount *pmp, u_long start, u_long count, u_long fillwith, u_long *retcluster, u_long *got);
 104 int fatentry (int function, struct msdosfsmount *pmp, u_long cluster, u_long *oldcontents, u_long newcontents);
 105 int freeclusterchain (struct msdosfsmount *pmp, u_long startchain);
 106 int extendfile (struct denode *dep, u_long count, struct buf **bpp, u_long *ncp, int flags);
 107 void fc_purge (struct denode *dep, u_int frcn);
 108
 109 #endif  /* _KERNEL */