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      1 /*	$NetBSD: denode.h,v 1.29 2021/10/23 16:58:17 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
      5  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
      6  * All rights reserved.
      7  * Original code by Paul Popelka (paulp (at) uts.amdahl.com) (see below).
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed by TooLs GmbH.
     20  * 4. The name of TooLs GmbH may not be used to endorse or promote products
     21  *    derived from this software without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
     24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     26  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     28  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     29  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     30  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     31  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     32  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     33  */
     34 /*
     35  * Written by Paul Popelka (paulp (at) uts.amdahl.com)
     36  *
     37  * You can do anything you want with this software, just don't say you wrote
     38  * it, and don't remove this notice.
     39  *
     40  * This software is provided "as is".
     41  *
     42  * The author supplies this software to be publicly redistributed on the
     43  * understanding that the author is not responsible for the correct
     44  * functioning of this software in any circumstances and is not liable for
     45  * any damages caused by this software.
     46  *
     47  * October 1992
     48  */
     49 #ifndef _MSDOSFS_DENODE_H_
     50 #define _MSDOSFS_DENODE_H_
     51 
     52 #ifndef MAKEFS
     53 #include <miscfs/genfs/genfs_node.h>
     54 #else
     55 struct genfs_node {
     56 };
     57 struct vnode;
     58 struct msdosfsmount;
     59 struct buf;
     60 #endif
     61 
     62 /*
     63  * This is the pc filesystem specific portion of the vnode structure.
     64  *
     65  * To describe a file uniquely the de_dirclust, de_diroffset, and
     66  * de_StartCluster fields are used.
     67  *
     68  * de_dirclust contains the cluster number of the directory cluster
     69  *	containing the entry for a file or directory.
     70  * de_diroffset is the index into the cluster for the entry describing
     71  *	a file or directory.
     72  * de_StartCluster is the number of the first cluster of the file or directory.
     73  *
     74  * Now to describe the quirks of the pc filesystem.
     75  * - Clusters 0 and 1 are reserved.
     76  * - The first allocatable cluster is 2.
     77  * - The root directory is of fixed size and all blocks that make it up
     78  *   are contiguous.
     79  * - Cluster 0 refers to the root directory when it is found in the
     80  *   startcluster field of a directory entry that points to another directory.
     81  * - Cluster 0 implies a 0 length file when found in the start cluster field
     82  *   of a directory entry that points to a file.
     83  * - You can't use the cluster number 0 to derive the address of the root
     84  *   directory.
     85  * - Multiple directory entries can point to a directory. The entry in the
     86  *   parent directory points to a child directory.  Any directories in the
     87  *   child directory contain a ".." entry that points back to the parent.
     88  *   The child directory itself contains a "." entry that points to itself.
     89  * - The root directory does not contain a "." or ".." entry.
     90  * - Directory entries for directories are never changed once they are created
     91  *   (except when removed).  The size stays 0, and the last modification time
     92  *   is never changed.  This is because so many directory entries can point to
     93  *   the physical clusters that make up a directory.  It would lead to an
     94  *   update nightmare.
     95  * - The length field in a directory entry pointing to a directory contains 0
     96  *   (always).  The only way to find the end of a directory is to follow the
     97  *   cluster chain until the "last cluster" marker is found.
     98  *
     99  * My extensions to make this house of cards work.  These apply only to the in
    100  * memory copy of the directory entry.
    101  * - A reference count for each denode will be kept since dos doesn't keep such
    102  *   things.
    103  */
    104 
    105 /*
    106  * Internal pseudo-offset for (nonexistent) directory entry for the root
    107  * dir in the root dir
    108  */
    109 #define	MSDOSFSROOT_OFS	0x1fffffff
    110 
    111 /*
    112  * The FAT cache structure. fc_fsrcn is the filesystem relative cluster
    113  * number that corresponds to the file relative cluster number in this
    114  * structure (fc_frcn).
    115  */
    116 struct fatcache {
    117 	u_long fc_frcn;		/* file relative cluster number */
    118 	u_long fc_fsrcn;	/* filesystem relative cluster number */
    119 };
    120 
    121 /*
    122  * The FAT entry cache as it stands helps make extending files a "quick"
    123  * operation by avoiding having to scan the FAT to discover the last
    124  * cluster of the file. The cache also helps sequential reads by
    125  * remembering the last cluster read from the file.  This also prevents us
    126  * from having to rescan the FAT to find the next cluster to read.  This
    127  * cache is probably pretty worthless if a file is opened by multiple
    128  * processes.
    129  */
    130 #define	FC_SIZE		3	/* number of entries in the cache */
    131 #define	FC_LASTMAP	0	/* entry the last call to pcbmap() resolved
    132 				 * to */
    133 #define	FC_LASTFC	1	/* entry for the last cluster in the file */
    134 #define	FC_NEXTTOLASTFC	2	/* entry for a close to the last cluster in the file */
    135 
    136 #define	FCE_EMPTY	0xffffffff	/* doesn't represent an actual cluster # */
    137 
    138 /*
    139  * Set a slot in the FAT cache.
    140  */
    141 #define	fc_setcache(dep, slot, frcn, fsrcn) \
    142 	(dep)->de_fc[slot].fc_frcn = frcn; \
    143 	(dep)->de_fc[slot].fc_fsrcn = fsrcn;
    144 
    145 #define fc_last_to_nexttolast(dep) \
    146 	do {  \
    147 		(dep)->de_fc[FC_NEXTTOLASTFC].fc_frcn = (dep)->de_fc[FC_LASTFC].fc_frcn; \
    148 		(dep)->de_fc[FC_NEXTTOLASTFC].fc_fsrcn = (dep)->de_fc[FC_LASTFC].fc_fsrcn; \
    149 	} while (0)
    150 
    151 /*
    152  * Auxiliary results from an msdosfs_lookup operation
    153  */
    154 struct msdosfs_lookup_results {
    155 	u_long mlr_fndoffset;	/* offset of found dir entry */
    156 	int mlr_fndcnt;		/* number of slots before de_fndoffset */
    157 };
    158 
    159 /*
    160  * This is the in memory variant of a dos directory entry.  It is usually
    161  * contained within a vnode.
    162  */
    163 struct denode_key {
    164 	u_long dk_dirclust;	/* cluster of the directory file containing this entry */
    165 	u_long dk_diroffset;	/* offset of this entry in the directory cluster */
    166 	void *dk_dirgen;	/* non zero and unique for unlinked nodes */
    167 };
    168 struct denode {
    169 	struct genfs_node de_gnode;
    170 	struct vnode *de_vnode;	/* addr of vnode we are part of */
    171 	struct vnode *de_devvp;	/* vnode of blk dev we live on */
    172 	u_long de_flag;		/* flag bits */
    173 	dev_t de_dev;		/* device where direntry lives */
    174 	struct denode_key de_key;
    175 #define de_dirclust de_key.dk_dirclust
    176 #define de_diroffset de_key.dk_diroffset
    177 #define de_dirgen de_key.dk_dirgen
    178 	struct msdosfs_lookup_results de_crap;	/* results from lookup */
    179 	long de_refcnt;		/* reference count */
    180 	struct msdosfsmount *de_pmp;	/* addr of our mount struct */
    181 	struct lockf *de_lockf;	/* byte level lock list */
    182 	u_char de_Name[12];	/* name, from DOS directory entry */
    183 	u_char de_Attributes;	/* attributes, from directory entry */
    184 	u_char de_CHun;		/* Hundredth of second of CTime*/
    185 	u_short de_CTime;	/* creation time */
    186 	u_short de_CDate;	/* creation date */
    187 	u_short de_ADate;	/* access date */
    188 	u_short de_MTime;	/* modification time */
    189 	u_short de_MDate;	/* modification date */
    190 	u_long de_StartCluster; /* starting cluster of file */
    191 	u_long de_FileSize;	/* size of file in bytes */
    192 	struct fatcache de_fc[FC_SIZE];	/* FAT cache */
    193 };
    194 
    195 /*
    196  * Values for the de_flag field of the denode.
    197  */
    198 #define	DE_UPDATE	0x0001	/* Modification time update request. */
    199 #define	DE_CREATE	0x0002	/* Creation time update */
    200 #define	DE_ACCESS	0x0004	/* Access time update */
    201 #define	DE_MODIFIED	0x0008	/* Denode has been modified. */
    202 #define	DE_RENAME	0x0010	/* Denode is in the process of being renamed */
    203 
    204 /*
    205  * Maximum filename length in Win95
    206  * Note: Must be < sizeof(dirent.d_name)
    207  */
    208 #define	WIN_MAXLEN	255
    209 
    210 /* Maximum size of a file on a FAT filesystem */
    211 #define MSDOSFS_FILESIZE_MAX	0xFFFFFFFFLL
    212 
    213 /*
    214  * Transfer directory entries between internal and external form.
    215  * dep is a struct denode * (internal form),
    216  * dp is a struct direntry * (external form).
    217  */
    218 #define DE_INTERNALIZE32(dep, dp)			\
    219 	 ((dep)->de_StartCluster |= getushort((dp)->deHighClust) << 16)
    220 #define DE_INTERNALIZE(dep, dp)				\
    221 	(memcpy((dep)->de_Name, (dp)->deName, 8),	\
    222 	 memcpy((dep)->de_Name+8, (dp)->deExtension, 3),\
    223 	 (dep)->de_Attributes = (dp)->deAttributes,	\
    224 	 (dep)->de_CHun = (dp)->deCHundredth,		\
    225 	 (dep)->de_CTime = getushort((dp)->deCTime),	\
    226 	 (dep)->de_CDate = getushort((dp)->deCDate),	\
    227 	 (dep)->de_ADate = getushort((dp)->deADate),	\
    228 	 (dep)->de_MTime = getushort((dp)->deMTime),	\
    229 	 (dep)->de_MDate = getushort((dp)->deMDate),	\
    230 	 (dep)->de_StartCluster = getushort((dp)->deStartCluster), \
    231 	 (dep)->de_FileSize = getulong((dp)->deFileSize), \
    232 	 (FAT32((dep)->de_pmp) ? DE_INTERNALIZE32((dep), (dp)) : 0))
    233 
    234 #define DE_EXTERNALIZE32(dp, dep)			\
    235 	 putushort((dp)->deHighClust, (dep)->de_StartCluster >> 16)
    236 #define DE_EXTERNALIZE16(dp, dep)			\
    237 	 putushort((dp)->deHighClust, 0)
    238 #define DE_EXTERNALIZE(dp, dep)				\
    239 	(memcpy((dp)->deName, (dep)->de_Name, 8),	\
    240 	 memcpy((dp)->deExtension, (dep)->de_Name+8, 3),\
    241 	 (dp)->deAttributes = (dep)->de_Attributes,	\
    242 	 (dp)->deCHundredth = (dep)->de_CHun,		\
    243 	 putushort((dp)->deCTime, (dep)->de_CTime),	\
    244 	 putushort((dp)->deCDate, (dep)->de_CDate),	\
    245 	 putushort((dp)->deADate, (dep)->de_ADate),	\
    246 	 putushort((dp)->deMTime, (dep)->de_MTime),	\
    247 	 putushort((dp)->deMDate, (dep)->de_MDate),	\
    248 	 putushort((dp)->deStartCluster, (dep)->de_StartCluster), \
    249 	 putulong((dp)->deFileSize,			\
    250 	     ((dep)->de_Attributes & ATTR_DIRECTORY) ? 0 : (dep)->de_FileSize), \
    251 	 (FAT32((dep)->de_pmp) ? DE_EXTERNALIZE32((dp), (dep)) : DE_EXTERNALIZE16((dp), (dep))))
    252 
    253 #define	de_forw		de_chain[0]
    254 #define	de_back		de_chain[1]
    255 
    256 #if defined(_KERNEL) || defined(MAKEFS)
    257 
    258 #define	VTODE(vp)	((struct denode *)(vp)->v_data)
    259 #define	DETOV(de)	((de)->de_vnode)
    260 
    261 #define	DETIMES(dep, acc, mod, cre, gmtoff) \
    262 	while ((dep)->de_flag & (DE_UPDATE | DE_CREATE | DE_ACCESS)) \
    263 		msdosfs_detimes(dep, acc, mod, cre, gmtoff)
    264 
    265 /*
    266  * This overlays the fid structure (see fstypes.h)
    267  */
    268 struct defid {
    269 	u_int16_t defid_len;	/* length of structure */
    270 	u_int16_t defid_pad;	/* force 4-byte alignment */
    271 
    272 	u_int32_t defid_dirclust; /* cluster this dir entry came from */
    273 	u_int32_t defid_dirofs;	/* offset of entry within the cluster */
    274 	u_int32_t defid_gen;	/* generation number */
    275 };
    276 
    277 /*
    278  * Prototypes for MSDOSFS vnode operations
    279  */
    280 int	msdosfs_lookup		(void *);
    281 int	msdosfs_create		(void *);
    282 int	msdosfs_close		(void *);
    283 int	msdosfs_access		(void *);
    284 int	msdosfs_getattr		(void *);
    285 int	msdosfs_setattr		(void *);
    286 int	msdosfs_read		(void *);
    287 int	msdosfs_write		(void *);
    288 int	msdosfs_fsync		(void *);
    289 int	msdosfs_remove		(void *);
    290 int	msdosfs_rename		(void *);
    291 int	msdosfs_mkdir		(void *);
    292 int	msdosfs_rmdir		(void *);
    293 int	msdosfs_readdir		(void *);
    294 int	msdosfs_inactive	(void *);
    295 int	msdosfs_reclaim		(void *);
    296 int	msdosfs_bmap		(void *);
    297 int	msdosfs_strategy	(void *);
    298 int	msdosfs_print		(void *);
    299 int	msdosfs_advlock		(void *);
    300 int	msdosfs_pathconf	(void *);
    301 
    302 /*
    303  * Internal service routine prototypes.
    304  */
    305 struct componentname;
    306 struct direntry;
    307 struct kauth_cred;
    308 int	msdosfs_update(struct vnode *, const struct timespec *,
    309 	    const struct timespec *, int);
    310 int	msdosfs_createde(struct denode *, struct denode *,
    311 		const struct msdosfs_lookup_results *,
    312 		struct denode **, struct componentname *);
    313 int	msdosfs_deextend(struct denode *, u_long, struct kauth_cred *);
    314 #ifdef MAKEFS
    315 int	msdosfs_deget(struct msdosfsmount *, u_long, u_long, struct denode **);
    316 #else
    317 int	msdosfs_deget(struct msdosfsmount *, u_long, u_long, struct vnode **);
    318 #endif
    319 int	msdosfs_detrunc(struct denode *, u_long, int, struct kauth_cred *);
    320 int	msdosfs_deupdat(struct denode *, int);
    321 int	msdosfs_dosdirempty(struct denode *);
    322 int	msdosfs_readde(struct denode *, struct buf **, struct direntry **);
    323 int	msdosfs_readep(struct msdosfsmount *, u_long, u_long,
    324 		struct buf **, struct direntry **);
    325 int	msdosfs_removede(struct denode *, struct denode *,
    326 		const struct msdosfs_lookup_results *);
    327 int	msdosfs_uniqdosname(struct denode *, struct componentname *, u_char *);
    328 int	msdosfs_findwin95(struct denode *);
    329 int	msdosfs_gop_alloc(struct vnode *, off_t, off_t, int,
    330 	    struct kauth_cred *);
    331 void	msdosfs_gop_markupdate(struct vnode *, int);
    332 void	msdosfs_detimes(struct denode *, const struct timespec *,
    333 	    const struct timespec *, const struct timespec *, int);
    334 int	msdosfs_fh_enter(struct msdosfsmount *, uint32_t, uint32_t, uint32_t *);
    335 int	msdosfs_fh_remove(struct msdosfsmount *, uint32_t, uint32_t);
    336 int	msdosfs_fh_lookup(struct msdosfsmount *, uint32_t, uint32_t,
    337 	    uint32_t *);
    338 void	msdosfs_fh_destroy(struct msdosfsmount *);
    339 #endif	/* _KERNEL || MAKEFS */
    340 #endif /* _MSDOSFS_DENODE_H_ */
    341