denode.h revision 22975
1/* $Id$ */ 2/* $NetBSD: denode.h,v 1.8 1994/08/21 18:43:49 ws Exp $ */ 3 4/*- 5 * Copyright (C) 1994 Wolfgang Solfrank. 6 * Copyright (C) 1994 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 * This is the pc filesystem specific portion of the vnode structure. 53 * 54 * To describe a file uniquely the de_dirclust, de_diroffset, and 55 * de_StartCluster fields are used. 56 * 57 * de_dirclust contains the cluster number of the directory cluster 58 * containing the entry for a file or directory. 59 * de_diroffset is the index into the cluster for the entry describing 60 * a file or directory. 61 * de_StartCluster is the number of the first cluster of the file or directory. 62 * 63 * Now to describe the quirks of the pc filesystem. 64 * - Clusters 0 and 1 are reserved. 65 * - The first allocatable cluster is 2. 66 * - The root directory is of fixed size and all blocks that make it up 67 * are contiguous. 68 * - Cluster 0 refers to the root directory when it is found in the 69 * startcluster field of a directory entry that points to another directory. 70 * - Cluster 0 implies a 0 length file when found in the start cluster field 71 * of a directory entry that points to a file. 72 * - You can't use the cluster number 0 to derive the address of the root 73 * directory. 74 * - Multiple directory entries can point to a directory. The entry in the 75 * parent directory points to a child directory. Any directories in the 76 * child directory contain a ".." entry that points back to the parent. 77 * The child directory itself contains a "." entry that points to itself. 78 * - The root directory does not contain a "." or ".." entry. 79 * - Directory entries for directories are never changed once they are created 80 * (except when removed). The size stays 0, and the last modification time 81 * is never changed. This is because so many directory entries can point to 82 * the physical clusters that make up a directory. It would lead to an 83 * update nightmare. 84 * - The length field in a directory entry pointing to a directory contains 0 85 * (always). The only way to find the end of a directory is to follow the 86 * cluster chain until the "last cluster" marker is found. 87 * 88 * My extensions to make this house of cards work. These apply only to the in 89 * memory copy of the directory entry. 90 * - A reference count for each denode will be kept since dos doesn't keep such 91 * things. 92 */ 93 94/* 95 * Internal pseudo-offset for (nonexistent) directory entry for the root 96 * dir in the root dir 97 */ 98#define MSDOSFSROOT_OFS 0x1fffffff 99 100/* 101 * The fat cache structure. fc_fsrcn is the filesystem relative cluster 102 * number that corresponds to the file relative cluster number in this 103 * structure (fc_frcn). 104 */ 105struct fatcache { 106 u_short fc_frcn; /* file relative cluster number */ 107 u_short fc_fsrcn; /* filesystem relative cluster number */ 108}; 109 110/* 111 * The fat entry cache as it stands helps make extending files a "quick" 112 * operation by avoiding having to scan the fat to discover the last 113 * cluster of the file. The cache also helps sequential reads by 114 * remembering the last cluster read from the file. This also prevents us 115 * from having to rescan the fat to find the next cluster to read. This 116 * cache is probably pretty worthless if a file is opened by multiple 117 * processes. 118 */ 119#define FC_SIZE 2 /* number of entries in the cache */ 120#define FC_LASTMAP 0 /* entry the last call to pcbmap() resolved 121 * to */ 122#define FC_LASTFC 1 /* entry for the last cluster in the file */ 123 124#define FCE_EMPTY 0xffff /* doesn't represent an actual cluster # */ 125 126/* 127 * Set a slot in the fat cache. 128 */ 129#define fc_setcache(dep, slot, frcn, fsrcn) \ 130 (dep)->de_fc[slot].fc_frcn = frcn; \ 131 (dep)->de_fc[slot].fc_fsrcn = fsrcn; 132 133/* 134 * This is the in memory variant of a dos directory entry. It is usually 135 * contained within a vnode. 136 */ 137struct denode { 138 struct denode *de_next; /* Hash chain forward */ 139 struct denode **de_prev; /* Hash chain back */ 140 struct vnode *de_vnode; /* addr of vnode we are part of */ 141 struct vnode *de_devvp; /* vnode of blk dev we live on */ 142 u_long de_flag; /* flag bits */ 143 dev_t de_dev; /* device where direntry lives */ 144 u_long de_dirclust; /* cluster of the directory file containing this entry */ 145 u_long de_diroffset; /* ordinal of this entry in the directory */ 146 u_long de_fndclust; /* cluster of found dir entry */ 147 u_long de_fndoffset; /* offset of found dir entry */ 148 long de_refcnt; /* reference count */ 149 struct msdosfsmount *de_pmp; /* addr of our mount struct */ 150 struct lockf *de_lockf; /* byte level lock list */ 151 pid_t de_lockholder; /* current lock holder */ 152 pid_t de_lockwaiter; /* lock wanter */ 153 /* the next two fields must be contiguous in memory... */ 154 u_char de_Name[8]; /* name, from directory entry */ 155 u_char de_Extension[3]; /* extension, from directory entry */ 156 u_char de_Attributes; /* attributes, from directory entry */ 157 u_short de_Time; /* creation time */ 158 u_short de_Date; /* creation date */ 159 u_short de_StartCluster; /* starting cluster of file */ 160 u_long de_FileSize; /* size of file in bytes */ 161 struct fatcache de_fc[FC_SIZE]; /* fat cache */ 162 u_quad_t de_modrev; /* Revision level for lease. */ 163}; 164 165/* 166 * Values for the de_flag field of the denode. 167 */ 168#define DE_LOCKED 0x0001 /* directory entry is locked */ 169#define DE_WANTED 0x0002 /* someone wants this de */ 170#define DE_UPDATE 0x0004 /* modification time update request */ 171#define DE_MODIFIED 0x0080 /* denode has been modified, but DE_UPDATE 172 * isn't set */ 173 174/* 175 * Transfer directory entries between internal and external form. 176 * dep is a struct denode * (internal form), 177 * dp is a struct direntry * (external form). 178 */ 179#define DE_INTERNALIZE(dep, dp) \ 180 (bcopy((dp)->deName, (dep)->de_Name, 11), \ 181 (dep)->de_Attributes = (dp)->deAttributes, \ 182 (dep)->de_Time = getushort((dp)->deTime), \ 183 (dep)->de_Date = getushort((dp)->deDate), \ 184 (dep)->de_StartCluster = getushort((dp)->deStartCluster), \ 185 (dep)->de_FileSize = getulong((dp)->deFileSize)) 186 187#define DE_EXTERNALIZE(dp, dep) \ 188 (bcopy((dep)->de_Name, (dp)->deName, 11), \ 189 bzero((dp)->deReserved, 10), \ 190 (dp)->deAttributes = (dep)->de_Attributes, \ 191 putushort((dp)->deTime, (dep)->de_Time), \ 192 putushort((dp)->deDate, (dep)->de_Date), \ 193 putushort((dp)->deStartCluster, (dep)->de_StartCluster), \ 194 putulong((dp)->deFileSize, (dep)->de_FileSize)) 195 196#define de_forw de_chain[0] 197#define de_back de_chain[1] 198 199#ifdef KERNEL 200 201#define VTODE(vp) ((struct denode *)(vp)->v_data) 202#define DETOV(de) ((de)->de_vnode) 203 204#define DE_TIMES(dep, t) \ 205 if ((dep)->de_flag & DE_UPDATE) { \ 206 if (!((dep)->de_Attributes & ATTR_DIRECTORY)) { \ 207 struct timespec DE_TIMES_ts; \ 208 (dep)->de_flag |= DE_MODIFIED; \ 209 TIMEVAL_TO_TIMESPEC((t), &DE_TIMES_ts); \ 210 unix2dostime(&DE_TIMES_ts, &(dep)->de_Date, \ 211 &(dep)->de_Time); \ 212 (dep)->de_Attributes |= ATTR_ARCHIVE; \ 213 } \ 214 (dep)->de_flag &= ~DE_UPDATE; \ 215 } 216 217/* 218 * This overlays the fid structure (see mount.h) 219 */ 220struct defid { 221 u_short defid_len; /* length of structure */ 222 u_short defid_pad; /* force long alignment */ 223 224 u_long defid_dirclust; /* cluster this dir entry came from */ 225 u_long defid_dirofs; /* index of entry within the cluster */ 226 227 /* u_long defid_gen; generation number */ 228}; 229 230extern vop_t **msdosfs_vnodeop_p; 231 232int msdosfs_lookup __P((struct vop_lookup_args *)); 233int msdosfs_inactive __P((struct vop_inactive_args *)); 234int msdosfs_reclaim __P((struct vop_reclaim_args *)); 235 236/* 237 * Internal service routine prototypes. 238 */ 239int deget __P((struct msdosfsmount * pmp, u_long dirclust, u_long diroffset, struct direntry * direntptr, struct denode ** depp)); 240#endif /* KERNEL */ 241