xref: /freebsd/sys/fs/msdosfs/denode.h (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
1 /* $FreeBSD$ */
2 /*	$NetBSD: denode.h,v 1.25 1997/11/17 15:36:28 ws Exp $	*/
3 
4 /*-
5  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
6  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
7  * All rights reserved.
8  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by TooLs GmbH.
21  * 4. The name of TooLs GmbH may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 /*-
36  * Written by Paul Popelka (paulp@uts.amdahl.com)
37  *
38  * You can do anything you want with this software, just don't say you wrote
39  * it, and don't remove this notice.
40  *
41  * This software is provided "as is".
42  *
43  * The author supplies this software to be publicly redistributed on the
44  * understanding that the author is not responsible for the correct
45  * functioning of this software in any circumstances and is not liable for
46  * any damages caused by this software.
47  *
48  * October 1992
49  */
50 
51 /*
52  * This is the pc filesystem specific portion of the vnode structure.
53  *
54  * To describe a file uniquely the de_dirclust, de_diroffset, and
55  * de_StartCluster fields are used.
56  *
57  * de_dirclust contains the cluster number of the directory cluster
58  *	containing the entry for a file or directory.
59  * de_diroffset is the index into the cluster for the entry describing
60  *	a file or directory.
61  * de_StartCluster is the number of the first cluster of the file or directory.
62  *
63  * Now to describe the quirks of the pc filesystem.
64  * - Clusters 0 and 1 are reserved.
65  * - The first allocatable cluster is 2.
66  * - The root directory is of fixed size and all blocks that make it up
67  *   are contiguous.
68  * - Cluster 0 refers to the root directory when it is found in the
69  *   startcluster field of a directory entry that points to another directory.
70  * - Cluster 0 implies a 0 length file when found in the start cluster field
71  *   of a directory entry that points to a file.
72  * - You can't use the cluster number 0 to derive the address of the root
73  *   directory.
74  * - Multiple directory entries can point to a directory. The entry in the
75  *   parent directory points to a child directory.  Any directories in the
76  *   child directory contain a ".." entry that points back to the parent.
77  *   The child directory itself contains a "." entry that points to itself.
78  * - The root directory does not contain a "." or ".." entry.
79  * - Directory entries for directories are never changed once they are created
80  *   (except when removed).  The size stays 0, and the last modification time
81  *   is never changed.  This is because so many directory entries can point to
82  *   the physical clusters that make up a directory.  It would lead to an
83  *   update nightmare.
84  * - The length field in a directory entry pointing to a directory contains 0
85  *   (always).  The only way to find the end of a directory is to follow the
86  *   cluster chain until the "last cluster" marker is found.
87  *
88  * My extensions to make this house of cards work.  These apply only to the in
89  * memory copy of the directory entry.
90  * - A reference count for each denode will be kept since dos doesn't keep such
91  *   things.
92  */
93 
94 /*
95  * Internal pseudo-offset for (nonexistent) directory entry for the root
96  * dir in the root dir
97  */
98 #define	MSDOSFSROOT_OFS	0x1fffffff
99 
100 /*
101  * The fat cache structure. fc_fsrcn is the filesystem relative cluster
102  * number that corresponds to the file relative cluster number in this
103  * structure (fc_frcn).
104  */
105 struct fatcache {
106 	u_long fc_frcn;		/* file relative cluster number */
107 	u_long fc_fsrcn;	/* filesystem relative cluster number */
108 };
109 
110 /*
111  * The fat entry cache as it stands helps make extending files a "quick"
112  * operation by avoiding having to scan the fat to discover the last
113  * cluster of the file. The cache also helps sequential reads by
114  * remembering the last cluster read from the file.  This also prevents us
115  * from having to rescan the fat to find the next cluster to read.  This
116  * cache is probably pretty worthless if a file is opened by multiple
117  * processes.
118  */
119 #define	FC_SIZE		3	/* number of entries in the cache */
120 #define	FC_LASTMAP	0	/* entry the last call to pcbmap() resolved
121 				 * to */
122 #define	FC_LASTFC	1	/* entry for the last cluster in the file */
123 #define	FC_NEXTTOLASTFC	2	/* entry for a close to the last cluster in
124 				 * the file */
125 
126 #define	FCE_EMPTY	0xffffffff	/* doesn't represent an actual cluster # */
127 
128 /*
129  * Set a slot in the fat cache.
130  */
131 #define	fc_setcache(dep, slot, frcn, fsrcn) \
132 	(dep)->de_fc[(slot)].fc_frcn = (frcn); \
133 	(dep)->de_fc[(slot)].fc_fsrcn = (fsrcn);
134 
135 /*
136  * This is the in memory variant of a dos directory entry.  It is usually
137  * contained within a vnode.
138  */
139 struct denode {
140 	struct vnode *de_vnode;	/* addr of vnode we are part of */
141 	u_long de_flag;		/* flag bits */
142 	u_long de_dirclust;	/* cluster of the directory file containing this entry */
143 	u_long de_diroffset;	/* offset of this entry in the directory cluster */
144 	u_long de_fndoffset;	/* offset of found dir entry */
145 	int de_fndcnt;		/* number of slots before de_fndoffset */
146 	long de_refcnt;		/* reference count */
147 	struct msdosfsmount *de_pmp;	/* addr of our mount struct */
148 	u_char de_Name[12];	/* name, from DOS directory entry */
149 	u_char de_Attributes;	/* attributes, from directory entry */
150 	u_char de_LowerCase;	/* NT VFAT lower case flags */
151 	u_char de_CHun;		/* Hundredth of second of CTime*/
152 	u_short de_CTime;	/* creation time */
153 	u_short de_CDate;	/* creation date */
154 	u_short de_ADate;	/* access date */
155 	u_short de_MTime;	/* modification time */
156 	u_short de_MDate;	/* modification date */
157 	u_long de_StartCluster; /* starting cluster of file */
158 	u_long de_FileSize;	/* size of file in bytes */
159 	struct fatcache de_fc[FC_SIZE];	/* fat cache */
160 	u_quad_t de_modrev;	/* Revision level for lease. */
161 	u_int64_t de_inode;	/* Inode number (really byte offset of direntry) */
162 };
163 
164 /*
165  * Values for the de_flag field of the denode.
166  */
167 #define	DE_UPDATE	0x0004	/* Modification time update request */
168 #define	DE_CREATE	0x0008	/* Creation time update */
169 #define	DE_ACCESS	0x0010	/* Access time update */
170 #define	DE_MODIFIED	0x0020	/* Denode has been modified */
171 #define	DE_RENAME	0x0040	/* Denode is in the process of being renamed */
172 
173 
174 /*
175  * Transfer directory entries between internal and external form.
176  * dep is a struct denode * (internal form),
177  * dp is a struct direntry * (external form).
178  */
179 #define DE_INTERNALIZE32(dep, dp)			\
180 	 ((dep)->de_StartCluster |= getushort((dp)->deHighClust) << 16)
181 #define DE_INTERNALIZE(dep, dp)				\
182 	(bcopy((dp)->deName, (dep)->de_Name, 11),	\
183 	 (dep)->de_Attributes = (dp)->deAttributes,	\
184 	 (dep)->de_LowerCase = (dp)->deLowerCase,	\
185 	 (dep)->de_CHun = (dp)->deCHundredth,		\
186 	 (dep)->de_CTime = getushort((dp)->deCTime),	\
187 	 (dep)->de_CDate = getushort((dp)->deCDate),	\
188 	 (dep)->de_ADate = getushort((dp)->deADate),	\
189 	 (dep)->de_MTime = getushort((dp)->deMTime),	\
190 	 (dep)->de_MDate = getushort((dp)->deMDate),	\
191 	 (dep)->de_StartCluster = getushort((dp)->deStartCluster), \
192 	 (dep)->de_FileSize = getulong((dp)->deFileSize), \
193 	 (FAT32((dep)->de_pmp) ? DE_INTERNALIZE32((dep), (dp)) : 0))
194 
195 #define DE_EXTERNALIZE(dp, dep)				\
196 	(bcopy((dep)->de_Name, (dp)->deName, 11),	\
197 	 (dp)->deAttributes = (dep)->de_Attributes,	\
198 	 (dp)->deLowerCase = (dep)->de_LowerCase,	\
199 	 (dp)->deCHundredth = (dep)->de_CHun,		\
200 	 putushort((dp)->deCTime, (dep)->de_CTime),	\
201 	 putushort((dp)->deCDate, (dep)->de_CDate),	\
202 	 putushort((dp)->deADate, (dep)->de_ADate),	\
203 	 putushort((dp)->deMTime, (dep)->de_MTime),	\
204 	 putushort((dp)->deMDate, (dep)->de_MDate),	\
205 	 putushort((dp)->deStartCluster, (dep)->de_StartCluster), \
206 	 putulong((dp)->deFileSize,			\
207 	     ((dep)->de_Attributes & ATTR_DIRECTORY) ? 0 : (dep)->de_FileSize), \
208 	 putushort((dp)->deHighClust, (dep)->de_StartCluster >> 16))
209 
210 #ifdef _KERNEL
211 
212 #define	VTODE(vp)	((struct denode *)(vp)->v_data)
213 #define	DETOV(de)	((de)->de_vnode)
214 
215 #define	DETIMES(dep, acc, mod, cre) do {				\
216 	if ((dep)->de_flag & DE_UPDATE) {				\
217 		(dep)->de_flag |= DE_MODIFIED;				\
218 		timespec2fattime((mod), 0, &(dep)->de_MDate,		\
219 		    &(dep)->de_MTime, NULL);				\
220 		(dep)->de_Attributes |= ATTR_ARCHIVE;			\
221 	}								\
222 	if ((dep)->de_pmp->pm_flags & MSDOSFSMNT_NOWIN95) {		\
223 		(dep)->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS);	\
224 		break;							\
225 	}								\
226 	if ((dep)->de_flag & DE_ACCESS) {				\
227 		u_int16_t adate;					\
228 									\
229 		timespec2fattime((acc), 0, &adate, NULL, NULL);		\
230 		if (adate != (dep)->de_ADate) {				\
231 			(dep)->de_flag |= DE_MODIFIED;			\
232 			(dep)->de_ADate = adate;			\
233 		}							\
234 	}								\
235 	if ((dep)->de_flag & DE_CREATE) {				\
236 		timespec2fattime((cre), 0, &(dep)->de_CDate,		\
237 		    &(dep)->de_CTime, &(dep)->de_CHun);			\
238 		(dep)->de_flag |= DE_MODIFIED;				\
239 	}								\
240 	(dep)->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS);		\
241 } while (0)
242 
243 /*
244  * This overlays the fid structure (see mount.h)
245  */
246 struct defid {
247 	u_short defid_len;	/* length of structure */
248 	u_short defid_pad;	/* force long 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 extern struct vop_vector msdosfs_vnodeops;
258 
259 int msdosfs_lookup(struct vop_cachedlookup_args *);
260 int msdosfs_inactive(struct vop_inactive_args *);
261 int msdosfs_reclaim(struct vop_reclaim_args *);
262 
263 /*
264  * Internal service routine prototypes.
265  */
266 int deget(struct msdosfsmount *, u_long, u_long, struct denode **);
267 int uniqdosname(struct denode *, struct componentname *, u_char *);
268 
269 int readep(struct msdosfsmount *pmp, u_long dirclu, u_long dirofs,  struct buf **bpp, struct direntry **epp);
270 int readde(struct denode *dep, struct buf **bpp, struct direntry **epp);
271 int deextend(struct denode *dep, u_long length, struct ucred *cred);
272 int fillinusemap(struct msdosfsmount *pmp);
273 void reinsert(struct denode *dep);
274 int dosdirempty(struct denode *dep);
275 int createde(struct denode *dep, struct denode *ddep, struct denode **depp, struct componentname *cnp);
276 int deupdat(struct denode *dep, int waitfor);
277 int removede(struct denode *pdep, struct denode *dep);
278 int detrunc(struct denode *dep, u_long length, int flags, struct ucred *cred);
279 int doscheckpath( struct denode *source, struct denode *target);
280 #endif	/* _KERNEL */
281