xref: /freebsd/sys/fs/msdosfs/denode.h (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*	$NetBSD: denode.h,v 1.25 1997/11/17 15:36:28 ws Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-4-Clause
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 #ifndef _FS_MSDOSFS_DENODE_H_
52 #define	_FS_MSDOSFS_DENODE_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
127 				 * the file */
128 
129 #define	FCE_EMPTY	0xffffffff	/* doesn't represent an actual cluster # */
130 
131 /*
132  * Set a slot in the FAT cache.
133  */
134 #define	fc_setcache(dep, slot, frcn, fsrcn) \
135 	(dep)->de_fc[(slot)].fc_frcn = (frcn); \
136 	(dep)->de_fc[(slot)].fc_fsrcn = (fsrcn);
137 
138 /*
139  * This is the in memory variant of a dos directory entry.  It is usually
140  * contained within a vnode.
141  */
142 struct denode {
143 	struct vnode *de_vnode;	/* addr of vnode we are part of */
144 	struct vn_clusterw de_clusterw;	/* buffer clustering information */
145 	u_long de_flag;		/* flag bits */
146 	u_long de_dirclust;	/* cluster of the directory file containing this entry */
147 	u_long de_diroffset;	/* offset of this entry in the directory cluster */
148 	u_long de_fndoffset;	/* offset of found dir entry */
149 	int de_fndcnt;		/* number of slots before de_fndoffset */
150 	long de_refcnt;		/* reference count */
151 	struct msdosfsmount *de_pmp;	/* addr of our mount struct */
152 	u_char de_Name[12];	/* name, from DOS directory entry */
153 	u_char de_Attributes;	/* attributes, from directory entry */
154 	u_char de_LowerCase;	/* NT VFAT lower case flags */
155 	u_char de_CHun;		/* Hundredth of second of CTime*/
156 	u_short de_CTime;	/* creation time */
157 	u_short de_CDate;	/* creation date */
158 	u_short de_ADate;	/* access date */
159 	u_short de_MTime;	/* modification time */
160 	u_short de_MDate;	/* modification date */
161 	u_long de_StartCluster; /* starting cluster of file */
162 	u_long de_FileSize;	/* size of file in bytes */
163 	struct fatcache de_fc[FC_SIZE];	/* FAT cache */
164 	u_quad_t de_modrev;	/* Revision level for lease. */
165 	uint64_t de_inode;	/* Inode number (really index of DOS style direntry) */
166 };
167 
168 /*
169  * Values for the de_flag field of the denode.
170  */
171 #define	DE_UPDATE	0x0004	/* Modification time update request */
172 #define	DE_CREATE	0x0008	/* Creation time update */
173 #define	DE_ACCESS	0x0010	/* Access time update */
174 #define	DE_MODIFIED	0x0020	/* Denode has been modified */
175 
176 /* Maximum size of a file on a FAT filesystem */
177 #define MSDOSFS_FILESIZE_MAX	0xFFFFFFFFLL
178 
179 /*
180  * Transfer directory entries between internal and external form.
181  * dep is a struct denode * (internal form),
182  * dp is a struct direntry * (external form).
183  */
184 #define DE_INTERNALIZE32(dep, dp)			\
185 	 ((dep)->de_StartCluster |= getushort((dp)->deHighClust) << 16)
186 #define DE_INTERNALIZE(dep, dp)				\
187 	(memcpy((dep)->de_Name, (dp)->deName, 11),	\
188 	 (dep)->de_Attributes = (dp)->deAttributes,	\
189 	 (dep)->de_LowerCase = (dp)->deLowerCase,	\
190 	 (dep)->de_CHun = (dp)->deCHundredth,		\
191 	 (dep)->de_CTime = getushort((dp)->deCTime),	\
192 	 (dep)->de_CDate = getushort((dp)->deCDate),	\
193 	 (dep)->de_ADate = getushort((dp)->deADate),	\
194 	 (dep)->de_MTime = getushort((dp)->deMTime),	\
195 	 (dep)->de_MDate = getushort((dp)->deMDate),	\
196 	 (dep)->de_StartCluster = getushort((dp)->deStartCluster), \
197 	 (dep)->de_FileSize = getulong((dp)->deFileSize), \
198 	 (FAT32((dep)->de_pmp) ? DE_INTERNALIZE32((dep), (dp)) : 0))
199 
200 #define DE_EXTERNALIZE(dp, dep)				\
201 	(memcpy((dp)->deName, (dep)->de_Name, 11),	\
202 	 (dp)->deAttributes = (dep)->de_Attributes,	\
203 	 (dp)->deLowerCase = (dep)->de_LowerCase,	\
204 	 (dp)->deCHundredth = (dep)->de_CHun,		\
205 	 putushort((dp)->deCTime, (dep)->de_CTime),	\
206 	 putushort((dp)->deCDate, (dep)->de_CDate),	\
207 	 putushort((dp)->deADate, (dep)->de_ADate),	\
208 	 putushort((dp)->deMTime, (dep)->de_MTime),	\
209 	 putushort((dp)->deMDate, (dep)->de_MDate),	\
210 	 putushort((dp)->deStartCluster, (dep)->de_StartCluster), \
211 	 putulong((dp)->deFileSize,			\
212 	     ((dep)->de_Attributes & ATTR_DIRECTORY) ? 0 : (dep)->de_FileSize), \
213 	 putushort((dp)->deHighClust, (dep)->de_StartCluster >> 16))
214 
215 #if defined(_KERNEL) || defined(MAKEFS)
216 
217 #define	VTODE(vp)	((struct denode *)(vp)->v_data)
218 #define	DETOV(de)	((de)->de_vnode)
219 
220 #define DETOI(pmp, cn, off)						\
221 	((cn) == MSDOSFSROOT						\
222 	    ? (((uint64_t)(off) >> 5))					\
223 	    : (((((uint64_t)pmp->pm_bpcluster * ((cn) - 2) + (off))) >> 5) \
224 		+ pmp->pm_RootDirEnts))
225 
226 #define	DETIMES(dep, acc, mod, cre) do {				\
227 	if ((dep)->de_flag & DE_UPDATE) {				\
228 		(dep)->de_flag |= DE_MODIFIED;				\
229 		timespec2fattime((mod), 0, &(dep)->de_MDate,		\
230 		    &(dep)->de_MTime, NULL);				\
231 		(dep)->de_Attributes |= ATTR_ARCHIVE;			\
232 	}								\
233 	if ((dep)->de_pmp->pm_flags & MSDOSFSMNT_NOWIN95) {		\
234 		(dep)->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS);	\
235 		break;							\
236 	}								\
237 	if ((dep)->de_flag & DE_ACCESS) {				\
238 		uint16_t adate;						\
239 									\
240 		timespec2fattime((acc), 0, &adate, NULL, NULL);		\
241 		if (adate != (dep)->de_ADate) {				\
242 			(dep)->de_flag |= DE_MODIFIED;			\
243 			(dep)->de_ADate = adate;			\
244 		}							\
245 	}								\
246 	if ((dep)->de_flag & DE_CREATE) {				\
247 		timespec2fattime((cre), 0, &(dep)->de_CDate,		\
248 		    &(dep)->de_CTime, &(dep)->de_CHun);			\
249 		(dep)->de_flag |= DE_MODIFIED;				\
250 	}								\
251 	(dep)->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS);		\
252 } while (0)
253 
254 /*
255  * This overlays the fid structure (see mount.h)
256  */
257 struct defid {
258 	u_short defid_len;	/* length of structure */
259 	u_short defid_pad;	/* force long alignment */
260 
261 	uint32_t defid_dirclust; /* cluster this dir entry came from */
262 	uint32_t defid_dirofs;	/* offset of entry within the cluster */
263 #if 0
264 	uint32_t defid_gen;	/* generation number */
265 #endif
266 };
267 
268 extern struct vop_vector msdosfs_vnodeops;
269 
270 #ifdef _KERNEL
271 int msdosfs_lookup(struct vop_cachedlookup_args *);
272 int msdosfs_inactive(struct vop_inactive_args *);
273 int msdosfs_reclaim(struct vop_reclaim_args *);
274 int msdosfs_lookup_ino(struct vnode *vdp, struct vnode **vpp,
275     struct componentname *cnp, daddr_t *scnp, u_long *blkoffp);
276 #endif
277 
278 /*
279  * Internal service routine prototypes.
280  */
281 struct componentname;
282 int deget(struct msdosfsmount *, u_long, u_long, int, struct denode **);
283 int uniqdosname(struct denode *, struct componentname *, u_char *);
284 
285 int readep(struct msdosfsmount *pmp, u_long dirclu, u_long dirofs,  struct buf **bpp, struct direntry **epp);
286 int readde(struct denode *dep, struct buf **bpp, struct direntry **epp);
287 int deextend(struct denode *dep, u_long length, struct ucred *cred);
288 int fillinusemap(struct msdosfsmount *pmp);
289 void reinsert(struct denode *dep);
290 int dosdirempty(struct denode *dep);
291 int createde(struct denode *dep, struct denode *ddep, struct denode **depp, struct componentname *cnp);
292 int deupdat(struct denode *dep, int waitfor);
293 int removede(struct denode *pdep, struct denode *dep);
294 int detrunc(struct denode *dep, u_long length, int flags, struct ucred *cred);
295 int doscheckpath( struct denode *source, struct denode *target,
296     daddr_t *wait_scn);
297 #endif	/* _KERNEL || MAKEFS */
298 #endif	/* !_FS_MSDOSFS_DENODE_H_ */
299