1/* $FreeBSD$ */ 2/* $NetBSD: denode.h,v 1.25 1997/11/17 15:36:28 ws Exp $ */ 3 4/*- 5 * SPDX-License-Identifier: BSD-4-Clause 6 * 7 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. 8 * Copyright (C) 1994, 1995, 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#ifndef _FS_MSDOSFS_DENODE_H_ 53#define _FS_MSDOSFS_DENODE_H_ 54 55/* 56 * This is the pc filesystem specific portion of the vnode structure. 57 * 58 * To describe a file uniquely the de_dirclust, de_diroffset, and 59 * de_StartCluster fields are used. 60 * 61 * de_dirclust contains the cluster number of the directory cluster 62 * containing the entry for a file or directory. 63 * de_diroffset is the index into the cluster for the entry describing 64 * a file or directory. 65 * de_StartCluster is the number of the first cluster of the file or directory. 66 * 67 * Now to describe the quirks of the pc filesystem. 68 * - Clusters 0 and 1 are reserved. 69 * - The first allocatable cluster is 2. 70 * - The root directory is of fixed size and all blocks that make it up 71 * are contiguous. 72 * - Cluster 0 refers to the root directory when it is found in the 73 * startcluster field of a directory entry that points to another directory. 74 * - Cluster 0 implies a 0 length file when found in the start cluster field 75 * of a directory entry that points to a file. 76 * - You can't use the cluster number 0 to derive the address of the root 77 * directory. 78 * - Multiple directory entries can point to a directory. The entry in the 79 * parent directory points to a child directory. Any directories in the 80 * child directory contain a ".." entry that points back to the parent. 81 * The child directory itself contains a "." entry that points to itself. 82 * - The root directory does not contain a "." or ".." entry. 83 * - Directory entries for directories are never changed once they are created 84 * (except when removed). The size stays 0, and the last modification time 85 * is never changed. This is because so many directory entries can point to 86 * the physical clusters that make up a directory. It would lead to an 87 * update nightmare. 88 * - The length field in a directory entry pointing to a directory contains 0 89 * (always). The only way to find the end of a directory is to follow the 90 * cluster chain until the "last cluster" marker is found. 91 * 92 * My extensions to make this house of cards work. These apply only to the in 93 * memory copy of the directory entry. 94 * - A reference count for each denode will be kept since dos doesn't keep such 95 * things. 96 */ 97 98/* 99 * Internal pseudo-offset for (nonexistent) directory entry for the root 100 * dir in the root dir 101 */ 102#define MSDOSFSROOT_OFS 0x1fffffff 103 104/* 105 * The FAT cache structure. fc_fsrcn is the filesystem relative cluster 106 * number that corresponds to the file relative cluster number in this 107 * structure (fc_frcn). 108 */ 109struct fatcache { 110 u_long fc_frcn; /* file relative cluster number */ 111 u_long fc_fsrcn; /* filesystem relative cluster number */ 112}; 113 114/* 115 * The FAT entry cache as it stands helps make extending files a "quick" 116 * operation by avoiding having to scan the FAT to discover the last 117 * cluster of the file. The cache also helps sequential reads by 118 * remembering the last cluster read from the file. This also prevents us 119 * from having to rescan the FAT to find the next cluster to read. This 120 * cache is probably pretty worthless if a file is opened by multiple 121 * processes. 122 */ 123#define FC_SIZE 3 /* number of entries in the cache */ 124#define FC_LASTMAP 0 /* entry the last call to pcbmap() resolved 125 * to */ 126#define FC_LASTFC 1 /* entry for the last cluster in the file */ 127#define FC_NEXTTOLASTFC 2 /* entry for a close to the last cluster in 128 * the file */ 129 130#define FCE_EMPTY 0xffffffff /* doesn't represent an actual cluster # */ 131 132/* 133 * Set a slot in the FAT cache. 134 */ 135#define fc_setcache(dep, slot, frcn, fsrcn) \ 136 (dep)->de_fc[(slot)].fc_frcn = (frcn); \ 137 (dep)->de_fc[(slot)].fc_fsrcn = (fsrcn); 138 139/* 140 * This is the in memory variant of a dos directory entry. It is usually 141 * contained within a vnode. 142 */ 143struct denode { 144 struct vnode *de_vnode; /* addr of vnode we are part of */ 145 u_long de_flag; /* flag bits */ 146 u_long de_dirclust; /* cluster of the directory file containing this entry */ 147 u_long de_diroffset; /* offset of this entry in the directory cluster */ 148 u_long de_fndoffset; /* offset of found dir entry */ 149 int de_fndcnt; /* number of slots before de_fndoffset */ 150 long de_refcnt; /* reference count */ 151 struct msdosfsmount *de_pmp; /* addr of our mount struct */ 152 u_char de_Name[12]; /* name, from DOS directory entry */ 153 u_char de_Attributes; /* attributes, from directory entry */ 154 u_char de_LowerCase; /* NT VFAT lower case flags */ 155 u_char de_CHun; /* Hundredth of second of CTime*/ 156 u_short de_CTime; /* creation time */ 157 u_short de_CDate; /* creation date */ 158 u_short de_ADate; /* access date */ 159 u_short de_MTime; /* modification time */ 160 u_short de_MDate; /* modification date */ 161 u_long de_StartCluster; /* starting cluster of file */ 162 u_long de_FileSize; /* size of file in bytes */ 163 struct fatcache de_fc[FC_SIZE]; /* FAT cache */ 164 uint64_t de_inode; /* Inode number (really byte offset of direntry) */ 165}; 166 167/* 168 * Values for the de_flag field of the denode. 169 */ 170#define DE_UPDATE 0x0004 /* Modification time update request */ 171#define DE_CREATE 0x0008 /* Creation time update */ 172#define DE_ACCESS 0x0010 /* Access time update */ 173#define DE_MODIFIED 0x0020 /* Denode has been modified */ 174#define DE_RENAME 0x0040 /* Denode is in the process of being renamed */ 175 176/* Maximum size of a file on a FAT filesystem */ 177#define MSDOSFS_FILESIZE_MAX 0xFFFFFFFFLL 178 179/* 180 * Transfer directory entries between internal and external form. 181 * dep is a struct denode * (internal form), 182 * dp is a struct direntry * (external form). 183 */ 184#define DE_INTERNALIZE32(dep, dp) \ 185 ((dep)->de_StartCluster |= getushort((dp)->deHighClust) << 16) 186#define DE_INTERNALIZE(dep, dp) \ 187 (memcpy((dep)->de_Name, (dp)->deName, 11), \ 188 (dep)->de_Attributes = (dp)->deAttributes, \ 189 (dep)->de_LowerCase = (dp)->deLowerCase, \ 190 (dep)->de_CHun = (dp)->deCHundredth, \ 191 (dep)->de_CTime = getushort((dp)->deCTime), \ 192 (dep)->de_CDate = getushort((dp)->deCDate), \ 193 (dep)->de_ADate = getushort((dp)->deADate), \ 194 (dep)->de_MTime = getushort((dp)->deMTime), \ 195 (dep)->de_MDate = getushort((dp)->deMDate), \ 196 (dep)->de_StartCluster = getushort((dp)->deStartCluster), \ 197 (dep)->de_FileSize = getulong((dp)->deFileSize), \ 198 (FAT32((dep)->de_pmp) ? DE_INTERNALIZE32((dep), (dp)) : 0)) 199 200#define DE_EXTERNALIZE(dp, dep) \ 201 (memcpy((dp)->deName, (dep)->de_Name, 11), \ 202 (dp)->deAttributes = (dep)->de_Attributes, \ 203 (dp)->deLowerCase = (dep)->de_LowerCase, \ 204 (dp)->deCHundredth = (dep)->de_CHun, \ 205 putushort((dp)->deCTime, (dep)->de_CTime), \ 206 putushort((dp)->deCDate, (dep)->de_CDate), \ 207 putushort((dp)->deADate, (dep)->de_ADate), \ 208 putushort((dp)->deMTime, (dep)->de_MTime), \ 209 putushort((dp)->deMDate, (dep)->de_MDate), \ 210 putushort((dp)->deStartCluster, (dep)->de_StartCluster), \ 211 putulong((dp)->deFileSize, \ 212 ((dep)->de_Attributes & ATTR_DIRECTORY) ? 0 : (dep)->de_FileSize), \ 213 putushort((dp)->deHighClust, (dep)->de_StartCluster >> 16)) 214 215#define VTODE(vp) ((struct denode *)(vp)->v_data) 216#define DETOV(de) ((de)->de_vnode) 217 218struct buf; 219struct msdosfsmount; 220struct direntry; 221struct componentname; 222struct denode; 223 224/* 225 * Internal service routine prototypes. 226 */ 227int deget(struct msdosfsmount *, u_long, u_long, struct denode **); 228int uniqdosname(struct denode *, struct componentname *, u_char *); 229 230int readep(struct msdosfsmount *pmp, u_long dirclu, u_long dirofs, struct buf **bpp, struct direntry **epp); 231int readde(struct denode *dep, struct buf **bpp, struct direntry **epp); 232int deextend(struct denode *dep, u_long length); 233int fillinusemap(struct msdosfsmount *pmp); 234int createde(struct denode *dep, struct denode *ddep, struct denode **depp, struct componentname *cnp); 235int removede(struct denode *pdep, struct denode *dep); 236int detrunc(struct denode *dep, u_long length, int flags); 237#endif /* !_FS_MSDOSFS_DENODE_H_ */ 238