sys/vfs/msdosfs/denode.h

   1 /* $FreeBSD: src/sys/msdosfs/denode.h,v 1.20 1999/12/29 04:54:52 peter Exp $ */
   2 /* $DragonFly: src/sys/vfs/msdosfs/denode.h,v 1.12 2006/09/10 01:26:41 dillon Exp $ */
   3 /*      $NetBSD: denode.h,v 1.25 1997/11/17 15:36:28 ws Exp $   */
   4
   5 /*-
   6  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
   7  * Copyright (C) 1994, 1995, 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  * This is the pc filesystem specific portion of the vnode structure.
  54  *
  55  * To describe a file uniquely the de_dirclust, de_diroffset, and
  56  * de_StartCluster fields are used.
  57  *
  58  * de_dirclust contains the cluster number of the directory cluster
  59  *      containing the entry for a file or directory.
  60  * de_diroffset is the index into the cluster for the entry describing
  61  *      a file or directory.
  62  * de_StartCluster is the number of the first cluster of the file or directory.
  63  *
  64  * Now to describe the quirks of the pc filesystem.
  65  * - Clusters 0 and 1 are reserved.
  66  * - The first allocatable cluster is 2.
  67  * - The root directory is of fixed size and all blocks that make it up
  68  *   are contiguous.
  69  * - Cluster 0 refers to the root directory when it is found in the
  70  *   startcluster field of a directory entry that points to another directory.
  71  * - Cluster 0 implies a 0 length file when found in the start cluster field
  72  *   of a directory entry that points to a file.
  73  * - You can't use the cluster number 0 to derive the address of the root
  74  *   directory.
  75  * - Multiple directory entries can point to a directory. The entry in the
  76  *   parent directory points to a child directory.  Any directories in the
  77  *   child directory contain a ".." entry that points back to the parent.
  78  *   The child directory itself contains a "." entry that points to itself.
  79  * - The root directory does not contain a "." or ".." entry.
  80  * - Directory entries for directories are never changed once they are created
  81  *   (except when removed).  The size stays 0, and the last modification time
  82  *   is never changed.  This is because so many directory entries can point to
  83  *   the physical clusters that make up a directory.  It would lead to an
  84  *   update nightmare.
  85  * - The length field in a directory entry pointing to a directory contains 0
  86  *   (always).  The only way to find the end of a directory is to follow the
  87  *   cluster chain until the "last cluster" marker is found.
  88  *
  89  * My extensions to make this house of cards work.  These apply only to the in
  90  * memory copy of the directory entry.
  91  * - A reference count for each denode will be kept since dos doesn't keep such
  92  *   things.
  93  */
  94
  95 /*
  96  * Internal pseudo-offset for (nonexistent) directory entry for the root
  97  * dir in the root dir
  98  */
  99 #define MSDOSFSROOT_OFS 0x1fffffff
 100
 101 /*
 102  * The fat cache structure. fc_fsrcn is the filesystem relative cluster
 103  * number that corresponds to the file relative cluster number in this
 104  * structure (fc_frcn).
 105  */
 106 struct fatcache {
 107         u_long fc_frcn;         /* file relative cluster number */
 108         u_long fc_fsrcn;        /* filesystem relative cluster number */
 109 };
 110
 111 /*
 112  * The fat entry cache as it stands helps make extending files a "quick"
 113  * operation by avoiding having to scan the fat to discover the last
 114  * cluster of the file. The cache also helps sequential reads by
 115  * remembering the last cluster read from the file.  This also prevents us
 116  * from having to rescan the fat to find the next cluster to read.  This
 117  * cache is probably pretty worthless if a file is opened by multiple
 118  * processes.
 119  */
 120 #define FC_SIZE         2       /* number of entries in the cache */
 121 #define FC_LASTMAP      0       /* entry the last call to pcbmap() resolved
 122                                  * to */
 123 #define FC_LASTFC       1       /* entry for the last cluster in the file */
 124
 125 #define FCE_EMPTY       0xffffffff      /* doesn't represent an actual cluster # */
 126
 127 /*
 128  * Set a slot in the fat cache.
 129  */
 130 #define fc_setcache(dep, slot, frcn, fsrcn) \
 131         (dep)->de_fc[slot].fc_frcn = frcn; \
 132         (dep)->de_fc[slot].fc_fsrcn = fsrcn;
 133
 134 /*
 135  * This is the in memory variant of a dos directory entry.  It is usually
 136  * contained within a vnode.
 137  */
 138 struct denode {
 139         struct denode *de_next; /* Hash chain forward */
 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         cdev_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;    /* offset of this entry in the directory cluster */
 146         u_long de_fndoffset;    /* offset of found dir entry */
 147         int de_fndcnt;          /* number of slots before de_fndoffset */
 148         long de_refcnt;         /* reference count */
 149         struct msdosfsmount *de_pmp;    /* addr of our mount struct */
 150         u_char de_Name[12];     /* name, from DOS directory entry */
 151         u_char de_Attributes;   /* attributes, from directory entry */
 152         u_char de_LowerCase;    /* NT VFAT lower case flags */
 153         u_char de_CHun;         /* Hundredth of second of CTime*/
 154         u_short de_CTime;       /* creation time */
 155         u_short de_CDate;       /* creation date */
 156         u_short de_ADate;       /* access date */
 157         u_short de_MTime;       /* modification time */
 158         u_short de_MDate;       /* modification date */
 159         u_long 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_UPDATE       0x0004  /* Modification time update request */
 169 #define DE_CREATE       0x0008  /* Creation time update */
 170 #define DE_ACCESS       0x0010  /* Access time update */
 171 #define DE_MODIFIED     0x0020  /* Denode has been modified */
 172 #define DE_RENAME       0x0040  /* Denode is in the process of being renamed */
 173
 174
 175 /*
 176  * Transfer directory entries between internal and external form.
 177  * dep is a struct denode * (internal form),
 178  * dp is a struct direntry * (external form).
 179  */
 180 #define DE_INTERNALIZE32(dep, dp)                       \
 181          ((dep)->de_StartCluster |= getushort((dp)->deHighClust) << 16)
 182 #define DE_INTERNALIZE(dep, dp)                         \
 183         (bcopy((dp)->deName, (dep)->de_Name, 11),       \
 184          (dep)->de_Attributes = (dp)->deAttributes,     \
 185          (dep)->de_LowerCase = (dp)->deLowerCase,       \
 186          (dep)->de_CHun = (dp)->deCHundredth,           \
 187          (dep)->de_CTime = getushort((dp)->deCTime),    \
 188          (dep)->de_CDate = getushort((dp)->deCDate),    \
 189          (dep)->de_ADate = getushort((dp)->deADate),    \
 190          (dep)->de_MTime = getushort((dp)->deMTime),    \
 191          (dep)->de_MDate = getushort((dp)->deMDate),    \
 192          (dep)->de_StartCluster = getushort((dp)->deStartCluster), \
 193          (dep)->de_FileSize = getulong((dp)->deFileSize), \
 194          (FAT32((dep)->de_pmp) ? DE_INTERNALIZE32((dep), (dp)) : 0))
 195
 196 #define DE_EXTERNALIZE(dp, dep)                         \
 197         (bcopy((dep)->de_Name, (dp)->deName, 11),       \
 198          (dp)->deAttributes = (dep)->de_Attributes,     \
 199          (dp)->deLowerCase = (dep)->de_LowerCase,       \
 200          (dp)->deCHundredth = (dep)->de_CHun,           \
 201          putushort((dp)->deCTime, (dep)->de_CTime),     \
 202          putushort((dp)->deCDate, (dep)->de_CDate),     \
 203          putushort((dp)->deADate, (dep)->de_ADate),     \
 204          putushort((dp)->deMTime, (dep)->de_MTime),     \
 205          putushort((dp)->deMDate, (dep)->de_MDate),     \
 206          putushort((dp)->deStartCluster, (dep)->de_StartCluster), \
 207          putulong((dp)->deFileSize,                     \
 208              ((dep)->de_Attributes & ATTR_DIRECTORY) ? 0 : (dep)->de_FileSize), \
 209          putushort((dp)->deHighClust, (dep)->de_StartCluster >> 16))
 210
 211 #define de_forw         de_chain[0]
 212 #define de_back         de_chain[1]
 213
 214 #ifdef _KERNEL
 215
 216 #define VTODE(vp)       ((struct denode *)(vp)->v_data)
 217 #define DETOV(de)       ((de)->de_vnode)
 218
 219 #define DETIMES(dep, acc, mod, cre) do {                                \
 220         if ((dep)->de_flag & DE_UPDATE) {                               \
 221                 (dep)->de_flag |= DE_MODIFIED;                          \
 222                 unix2dostime((mod), &(dep)->de_MDate, &(dep)->de_MTime, \
 223                     NULL);                                              \
 224                 (dep)->de_Attributes |= ATTR_ARCHIVE;                   \
 225         }                                                               \
 226         if ((dep)->de_pmp->pm_flags & MSDOSFSMNT_NOWIN95) {             \
 227                 (dep)->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS); \
 228                 break;                                                  \
 229         }                                                               \
 230         if ((dep)->de_flag & DE_ACCESS) {                               \
 231                 u_int16_t adate;                                        \
 232                                                                         \
 233                 unix2dostime((acc), &adate, NULL, NULL);                \
 234                 if (adate != (dep)->de_ADate) {                         \
 235                         (dep)->de_flag |= DE_MODIFIED;                  \
 236                         (dep)->de_ADate = adate;                        \
 237                 }                                                       \
 238         }                                                               \
 239         if ((dep)->de_flag & DE_CREATE) {                               \
 240                 unix2dostime((cre), &(dep)->de_CDate, &(dep)->de_CTime, \
 241                     &(dep)->de_CHun);                                   \
 242                     (dep)->de_flag |= DE_MODIFIED;                      \
 243         }                                                               \
 244         (dep)->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS);         \
 245 } while (0);
 246
 247 /*
 248  * This overlays the fid structure (see mount.h)
 249  */
 250 struct defid {
 251         u_short defid_len;      /* length of structure */
 252         u_short defid_pad;      /* force long alignment */
 253
 254         u_long defid_dirclust;  /* cluster this dir entry came from */
 255         u_long defid_dirofs;    /* offset of entry within the cluster */
 256 #if 0
 257         u_long  defid_gen;      /* generation number */
 258 #endif
 259 };
 260
 261 int msdosfs_lookup (struct vop_old_lookup_args *);
 262 int msdosfs_inactive (struct vop_inactive_args *);
 263 int msdosfs_reclaim (struct vop_reclaim_args *);
 264
 265 /*
 266  * Internal service routine prototypes.
 267  */
 268 int deget (struct msdosfsmount *, u_long, u_long, struct denode **);
 269 int uniqdosname (struct denode *, struct componentname *, u_char *);
 270 int findwin95 (struct denode *);
 271
 272 int readep (struct msdosfsmount *pmp, u_long dirclu, u_long dirofs,  struct buf **bpp, struct direntry **epp);
 273 int readde (struct denode *dep, struct buf **bpp, struct direntry **epp);
 274 int deextend (struct denode *dep, u_long length);
 275 int fillinusemap (struct msdosfsmount *pmp);
 276 void msdosfs_reinsert(struct denode *ip, u_long new_dirclust, u_long new_diroffset);
 277 int dosdirempty (struct denode *dep);
 278 int createde (struct denode *dep, struct denode *ddep, struct denode **depp, struct componentname *cnp);
 279 int deupdat (struct denode *dep, int waitfor);
 280 int removede (struct denode *pdep, struct denode *dep);
 281 int detrunc (struct denode *dep, u_long length, int flags);
 282 int doscheckpath ( struct denode *source, struct denode *target);
 283 #endif  /* _KERNEL */