xref: /netbsd-src/sys/fs/msdosfs/denode.h (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: denode.h,v 1.18 2010/04/08 16:04:35 pooka 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 #include <miscfs/genfs/genfs_node.h>
53 
54 /*
55  * This is the pc filesystem specific portion of the vnode structure.
56  *
57  * To describe a file uniquely the de_dirclust, de_diroffset, and
58  * de_StartCluster fields are used.
59  *
60  * de_dirclust contains the cluster number of the directory cluster
61  *	containing the entry for a file or directory.
62  * de_diroffset is the index into the cluster for the entry describing
63  *	a file or directory.
64  * de_StartCluster is the number of the first cluster of the file or directory.
65  *
66  * Now to describe the quirks of the pc filesystem.
67  * - Clusters 0 and 1 are reserved.
68  * - The first allocatable cluster is 2.
69  * - The root directory is of fixed size and all blocks that make it up
70  *   are contiguous.
71  * - Cluster 0 refers to the root directory when it is found in the
72  *   startcluster field of a directory entry that points to another directory.
73  * - Cluster 0 implies a 0 length file when found in the start cluster field
74  *   of a directory entry that points to a file.
75  * - You can't use the cluster number 0 to derive the address of the root
76  *   directory.
77  * - Multiple directory entries can point to a directory. The entry in the
78  *   parent directory points to a child directory.  Any directories in the
79  *   child directory contain a ".." entry that points back to the parent.
80  *   The child directory itself contains a "." entry that points to itself.
81  * - The root directory does not contain a "." or ".." entry.
82  * - Directory entries for directories are never changed once they are created
83  *   (except when removed).  The size stays 0, and the last modification time
84  *   is never changed.  This is because so many directory entries can point to
85  *   the physical clusters that make up a directory.  It would lead to an
86  *   update nightmare.
87  * - The length field in a directory entry pointing to a directory contains 0
88  *   (always).  The only way to find the end of a directory is to follow the
89  *   cluster chain until the "last cluster" marker is found.
90  *
91  * My extensions to make this house of cards work.  These apply only to the in
92  * memory copy of the directory entry.
93  * - A reference count for each denode will be kept since dos doesn't keep such
94  *   things.
95  */
96 
97 /*
98  * Internal pseudo-offset for (nonexistent) directory entry for the root
99  * dir in the root dir
100  */
101 #define	MSDOSFSROOT_OFS	0x1fffffff
102 
103 /*
104  * The fat cache structure. fc_fsrcn is the filesystem relative cluster
105  * number that corresponds to the file relative cluster number in this
106  * structure (fc_frcn).
107  */
108 struct fatcache {
109 	u_long fc_frcn;		/* file relative cluster number */
110 	u_long fc_fsrcn;	/* filesystem relative cluster number */
111 };
112 
113 /*
114  * The fat entry cache as it stands helps make extending files a "quick"
115  * operation by avoiding having to scan the fat to discover the last
116  * cluster of the file. The cache also helps sequential reads by
117  * remembering the last cluster read from the file.  This also prevents us
118  * from having to rescan the fat to find the next cluster to read.  This
119  * cache is probably pretty worthless if a file is opened by multiple
120  * processes.
121  */
122 #define	FC_SIZE		3	/* number of entries in the cache */
123 #define	FC_LASTMAP	0	/* entry the last call to pcbmap() resolved
124 				 * to */
125 #define	FC_LASTFC	1	/* entry for the last cluster in the file */
126 #define	FC_NEXTTOLASTFC	2	/* entry for a close to the last cluster in the file */
127 
128 #define	FCE_EMPTY	0xffffffff	/* doesn't represent an actual cluster # */
129 
130 /*
131  * Set a slot in the fat cache.
132  */
133 #define	fc_setcache(dep, slot, frcn, fsrcn) \
134 	(dep)->de_fc[slot].fc_frcn = frcn; \
135 	(dep)->de_fc[slot].fc_fsrcn = fsrcn;
136 
137 #define fc_last_to_nexttolast(dep) \
138 	do {  \
139 		(dep)->de_fc[FC_NEXTTOLASTFC].fc_frcn = (dep)->de_fc[FC_LASTFC].fc_frcn; \
140 		(dep)->de_fc[FC_NEXTTOLASTFC].fc_fsrcn = (dep)->de_fc[FC_LASTFC].fc_fsrcn; \
141 	} while (0)
142 
143 
144 /*
145  * This is the in memory variant of a dos directory entry.  It is usually
146  * contained within a vnode.
147  */
148 struct denode {
149 	struct genfs_node de_gnode;
150 	LIST_ENTRY(denode) de_hash;
151 	struct vnode *de_vnode;	/* addr of vnode we are part of */
152 	struct vnode *de_devvp;	/* vnode of blk dev we live on */
153 	u_long de_flag;		/* flag bits */
154 	dev_t de_dev;		/* device where direntry lives */
155 	u_long de_dirclust;	/* cluster of the directory file containing this entry */
156 	u_long de_diroffset;	/* offset of this entry in the directory cluster */
157 	u_long de_fndoffset;	/* offset of found dir entry */
158 	int de_fndcnt;		/* number of slots before de_fndoffset */
159 	long de_refcnt;		/* reference count */
160 	struct msdosfsmount *de_pmp;	/* addr of our mount struct */
161 	struct lockf *de_lockf;	/* byte level lock list */
162 	u_char de_Name[12];	/* name, from DOS directory entry */
163 	u_char de_Attributes;	/* attributes, from directory entry */
164 	u_char de_CHun;		/* Hundredth of second of CTime*/
165 	u_short de_CTime;	/* creation time */
166 	u_short de_CDate;	/* creation date */
167 	u_short de_ADate;	/* access date */
168 	u_short de_MTime;	/* modification time */
169 	u_short de_MDate;	/* modification date */
170 	u_long de_StartCluster; /* starting cluster of file */
171 	u_long de_FileSize;	/* size of file in bytes */
172 	struct fatcache de_fc[FC_SIZE];	/* fat cache */
173 };
174 
175 /*
176  * Values for the de_flag field of the denode.
177  */
178 #define	DE_UPDATE	0x0001	/* Modification time update request. */
179 #define	DE_CREATE	0x0002	/* Creation time update */
180 #define	DE_ACCESS	0x0004	/* Access time update */
181 #define	DE_MODIFIED	0x0008	/* Denode has been modified. */
182 #define	DE_RENAME	0x0010	/* Denode is in the process of being renamed */
183 
184 /*
185  * Maximum filename length in Win95
186  * Note: Must be < sizeof(dirent.d_name)
187  */
188 #define	WIN_MAXLEN	255
189 
190 /* Maximum size of a file on a FAT filesystem */
191 #define MSDOSFS_FILESIZE_MAX	0xFFFFFFFFLL
192 
193 /*
194  * Transfer directory entries between internal and external form.
195  * dep is a struct denode * (internal form),
196  * dp is a struct direntry * (external form).
197  */
198 #define DE_INTERNALIZE32(dep, dp)			\
199 	 ((dep)->de_StartCluster |= getushort((dp)->deHighClust) << 16)
200 #define DE_INTERNALIZE(dep, dp)				\
201 	(memcpy((dep)->de_Name, (dp)->deName, 11),	\
202 	 (dep)->de_Attributes = (dp)->deAttributes,	\
203 	 (dep)->de_CHun = (dp)->deCHundredth,		\
204 	 (dep)->de_CTime = getushort((dp)->deCTime),	\
205 	 (dep)->de_CDate = getushort((dp)->deCDate),	\
206 	 (dep)->de_ADate = getushort((dp)->deADate),	\
207 	 (dep)->de_MTime = getushort((dp)->deMTime),	\
208 	 (dep)->de_MDate = getushort((dp)->deMDate),	\
209 	 (dep)->de_StartCluster = getushort((dp)->deStartCluster), \
210 	 (dep)->de_FileSize = getulong((dp)->deFileSize), \
211 	 (FAT32((dep)->de_pmp) ? DE_INTERNALIZE32((dep), (dp)) : 0))
212 
213 #define DE_EXTERNALIZE32(dp, dep)			\
214 	 putushort((dp)->deHighClust, (dep)->de_StartCluster >> 16)
215 #define DE_EXTERNALIZE16(dp, dep)			\
216 	 putushort((dp)->deHighClust, 0)
217 #define DE_EXTERNALIZE(dp, dep)				\
218 	(memcpy((dp)->deName, (dep)->de_Name, 11),	\
219 	 (dp)->deAttributes = (dep)->de_Attributes,	\
220 	 (dp)->deCHundredth = (dep)->de_CHun,		\
221 	 putushort((dp)->deCTime, (dep)->de_CTime),	\
222 	 putushort((dp)->deCDate, (dep)->de_CDate),	\
223 	 putushort((dp)->deADate, (dep)->de_ADate),	\
224 	 putushort((dp)->deMTime, (dep)->de_MTime),	\
225 	 putushort((dp)->deMDate, (dep)->de_MDate),	\
226 	 putushort((dp)->deStartCluster, (dep)->de_StartCluster), \
227 	 putulong((dp)->deFileSize,			\
228 	     ((dep)->de_Attributes & ATTR_DIRECTORY) ? 0 : (dep)->de_FileSize), \
229 	 (FAT32((dep)->de_pmp) ? DE_EXTERNALIZE32((dp), (dep)) : DE_EXTERNALIZE16((dp), (dep))))
230 
231 #define	de_forw		de_chain[0]
232 #define	de_back		de_chain[1]
233 
234 #ifdef _KERNEL
235 
236 #define	VTODE(vp)	((struct denode *)(vp)->v_data)
237 #define	DETOV(de)	((de)->de_vnode)
238 
239 #define	DETIMES(dep, acc, mod, cre, gmtoff) \
240 	while ((dep)->de_flag & (DE_UPDATE | DE_CREATE | DE_ACCESS)) \
241 		msdosfs_detimes(dep, acc, mod, cre, gmtoff)
242 
243 /*
244  * This overlays the fid structure (see fstypes.h)
245  */
246 struct defid {
247 	u_int16_t defid_len;	/* length of structure */
248 	u_int16_t defid_pad;	/* force 4-byte alignment */
249 
250 	u_int32_t defid_dirclust; /* cluster this dir entry came from */
251 	u_int32_t defid_dirofs;	/* offset of entry within the cluster */
252 #if 0
253 	u_int32_t defid_gen;	/* generation number */
254 #endif
255 };
256 
257 /*
258  * Prototypes for MSDOSFS vnode operations
259  */
260 int	msdosfs_lookup		(void *);
261 int	msdosfs_create		(void *);
262 int	msdosfs_close		(void *);
263 int	msdosfs_access		(void *);
264 int	msdosfs_getattr		(void *);
265 int	msdosfs_setattr		(void *);
266 int	msdosfs_read		(void *);
267 int	msdosfs_write		(void *);
268 #define	msdosfs_lease_check	genfs_lease_check
269 #define	msdosfs_ioctl		genfs_enoioctl
270 #define	msdosfs_poll		genfs_poll
271 #define	msdosfs_revoke		genfs_revoke
272 #define	msdosfs_mmap		genfs_mmap
273 int	msdosfs_fsync		(void *);
274 #define	msdosfs_seek		genfs_seek
275 int	msdosfs_remove		(void *);
276 int	msdosfs_rename		(void *);
277 int	msdosfs_mkdir		(void *);
278 int	msdosfs_rmdir		(void *);
279 int	msdosfs_readdir		(void *);
280 #define	msdosfs_abortop		genfs_abortop
281 int	msdosfs_inactive	(void *);
282 int	msdosfs_reclaim		(void *);
283 int	msdosfs_bmap		(void *);
284 int	msdosfs_strategy	(void *);
285 int	msdosfs_print		(void *);
286 int	msdosfs_advlock		(void *);
287 int	msdosfs_pathconf	(void *);
288 
289 /*
290  * Internal service routine prototypes.
291  */
292 int msdosfs_update(struct vnode *, const struct timespec *,
293 	    const struct timespec *, int);
294 int createde(struct denode *, struct denode *,
295 		struct denode **, struct componentname *);
296 int deextend(struct denode *, u_long, kauth_cred_t);
297 int deget(struct msdosfsmount *, u_long, u_long, struct denode **);
298 int detrunc(struct denode *, u_long, int, kauth_cred_t);
299 int deupdat(struct denode *, int);
300 int doscheckpath(struct denode *, struct denode *);
301 int dosdirempty(struct denode *);
302 int readde(struct denode *, struct buf **, struct direntry **);
303 int readep(struct msdosfsmount *, u_long, u_long,
304 		struct buf **, struct direntry **);
305 void reinsert(struct denode *);
306 int removede(struct denode *, struct denode *);
307 int uniqdosname(struct denode *, struct componentname *, u_char *);
308 int findwin95(struct denode *);
309 int msdosfs_gop_alloc(struct vnode *, off_t, off_t, int, kauth_cred_t);
310 void msdosfs_gop_markupdate(struct vnode *, int);
311 void msdosfs_detimes(struct denode *, const struct timespec *,
312     const struct timespec *, const struct timespec *, int);
313 #endif	/* _KERNEL */
314 #endif /* _MSDOSFS_DENODE_H_ */
315