xref: /netbsd/sys/fs/msdosfs/denode.h (revision 94e6dd9c)
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@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@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