xref: /freebsd/sys/fs/msdosfs/denode.h (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
1 /*	$Id: denode.h,v 1.2 1994/12/12 12:35:40 bde Exp $ */
2 /*	$NetBSD: denode.h,v 1.8 1994/08/21 18:43:49 ws Exp $	*/
3 
4 /*-
5  * Copyright (C) 1994 Wolfgang Solfrank.
6  * Copyright (C) 1994 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_short fc_frcn;	/* file relative cluster number */
107 	u_short 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		2	/* 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 
124 #define	FCE_EMPTY	0xffff	/* doesn't represent an actual cluster # */
125 
126 /*
127  * Set a slot in the fat cache.
128  */
129 #define	fc_setcache(dep, slot, frcn, fsrcn) \
130 	(dep)->de_fc[slot].fc_frcn = frcn; \
131 	(dep)->de_fc[slot].fc_fsrcn = fsrcn;
132 
133 /*
134  * This is the in memory variant of a dos directory entry.  It is usually
135  * contained within a vnode.
136  */
137 struct denode {
138 	struct denode *de_next;	/* Hash chain forward */
139 	struct denode **de_prev; /* Hash chain back */
140 	struct vnode *de_vnode;	/* addr of vnode we are part of */
141 	struct vnode *de_devvp;	/* vnode of blk dev we live on */
142 	u_long de_flag;		/* flag bits */
143 	dev_t de_dev;		/* device where direntry lives */
144 	u_long de_dirclust;	/* cluster of the directory file containing this entry */
145 	u_long de_diroffset;	/* ordinal of this entry in the directory */
146 	u_long de_fndclust;	/* cluster of found dir entry */
147 	u_long de_fndoffset;	/* offset of found dir entry */
148 	long de_refcnt;		/* reference count */
149 	struct msdosfsmount *de_pmp;	/* addr of our mount struct */
150 	struct lockf *de_lockf;	/* byte level lock list */
151 	pid_t de_lockholder;	/* current lock holder */
152 	pid_t de_lockwaiter;	/* lock wanter */
153 	/* the next two fields must be contiguous in memory... */
154 	u_char de_Name[8];	/* name, from directory entry */
155 	u_char de_Extension[3];	/* extension, from directory entry */
156 	u_char de_Attributes;	/* attributes, from directory entry */
157 	u_short de_Time;	/* creation time */
158 	u_short de_Date;	/* creation date */
159 	u_short de_StartCluster; /* starting cluster of file */
160 	u_long de_FileSize;	/* size of file in bytes */
161 	struct fatcache de_fc[FC_SIZE];	/* fat cache */
162 };
163 
164 /*
165  * Values for the de_flag field of the denode.
166  */
167 #define	DE_LOCKED	0x0001	/* directory entry is locked */
168 #define	DE_WANTED	0x0002	/* someone wants this de */
169 #define	DE_UPDATE	0x0004	/* modification time update request */
170 #define	DE_MODIFIED	0x0080	/* denode has been modified, but DE_UPDATE
171 				 * isn't set */
172 
173 /*
174  * Transfer directory entries between internal and external form.
175  * dep is a struct denode * (internal form),
176  * dp is a struct direntry * (external form).
177  */
178 #define DE_INTERNALIZE(dep, dp)			\
179 	(bcopy((dp)->deName, (dep)->de_Name, 11),	\
180 	 (dep)->de_Attributes = (dp)->deAttributes,	\
181 	 (dep)->de_Time = getushort((dp)->deTime),	\
182 	 (dep)->de_Date = getushort((dp)->deDate),	\
183 	 (dep)->de_StartCluster = getushort((dp)->deStartCluster), \
184 	 (dep)->de_FileSize = getulong((dp)->deFileSize))
185 
186 #define DE_EXTERNALIZE(dp, dep)				\
187 	(bcopy((dep)->de_Name, (dp)->deName, 11),	\
188 	 (dp)->deAttributes = (dep)->de_Attributes,	\
189 	 putushort((dp)->deTime, (dep)->de_Time),	\
190 	 putushort((dp)->deDate, (dep)->de_Date),	\
191 	 putushort((dp)->deStartCluster, (dep)->de_StartCluster), \
192 	 putulong((dp)->deFileSize, (dep)->de_FileSize))
193 
194 #define	de_forw		de_chain[0]
195 #define	de_back		de_chain[1]
196 
197 #ifdef KERNEL
198 
199 #define	VTODE(vp)	((struct denode *)(vp)->v_data)
200 #define	DETOV(de)	((de)->de_vnode)
201 
202 #define	DE_TIMES(dep, t) \
203 	if ((dep)->de_flag & DE_UPDATE) { \
204 		if (!((dep)->de_Attributes & ATTR_DIRECTORY)) { \
205 			struct timespec DE_TIMES_ts; \
206 			(dep)->de_flag |= DE_MODIFIED; \
207 			TIMEVAL_TO_TIMESPEC((t), &DE_TIMES_ts); \
208 			unix2dostime(&DE_TIMES_ts, &(dep)->de_Date, \
209 				     &(dep)->de_Time); \
210 			(dep)->de_Attributes |= ATTR_ARCHIVE; \
211 		} \
212 		(dep)->de_flag &= ~DE_UPDATE; \
213 	}
214 
215 /*
216  * This overlays the fid structure (see mount.h)
217  */
218 struct defid {
219 	u_short defid_len;	/* length of structure */
220 	u_short defid_pad;	/* force long alignment */
221 
222 	u_long defid_dirclust;	/* cluster this dir entry came from */
223 	u_long defid_dirofs;	/* index of entry within the cluster */
224 
225 	/* u_long	defid_gen;	 generation number */
226 };
227 
228 /*
229  * Prototypes for MSDOSFS vnode operations
230  */
231 int msdosfs_lookup __P((struct vop_lookup_args *));
232 int msdosfs_create __P((struct vop_create_args *));
233 int msdosfs_mknod __P((struct vop_mknod_args *));
234 int msdosfs_open __P((struct vop_open_args *));
235 int msdosfs_close __P((struct vop_close_args *));
236 int msdosfs_access __P((struct vop_access_args *));
237 int msdosfs_getattr __P((struct vop_getattr_args *));
238 int msdosfs_setattr __P((struct vop_setattr_args *));
239 int msdosfs_read __P((struct vop_read_args *));
240 int msdosfs_write __P((struct vop_write_args *));
241 int msdosfs_ioctl __P((struct vop_ioctl_args *));
242 int msdosfs_select __P((struct vop_select_args *));
243 int msdosfs_mmap __P((struct vop_mmap_args *));
244 int msdosfs_fsync __P((struct vop_fsync_args *));
245 int msdosfs_seek __P((struct vop_seek_args *));
246 int msdosfs_remove __P((struct vop_remove_args *));
247 int msdosfs_link __P((struct vop_link_args *));
248 int msdosfs_rename __P((struct vop_rename_args *));
249 int msdosfs_mkdir __P((struct vop_mkdir_args *));
250 int msdosfs_rmdir __P((struct vop_rmdir_args *));
251 int msdosfs_symlink __P((struct vop_symlink_args *));
252 int msdosfs_readdir __P((struct vop_readdir_args *));
253 int msdosfs_readlink __P((struct vop_readlink_args *));
254 int msdosfs_abortop __P((struct vop_abortop_args *));
255 int msdosfs_inactive __P((struct vop_inactive_args *));
256 int msdosfs_reclaim __P((struct vop_reclaim_args *));
257 int msdosfs_lock __P((struct vop_lock_args *));
258 int msdosfs_unlock __P((struct vop_unlock_args *));
259 int msdosfs_bmap __P((struct vop_bmap_args *));
260 int msdosfs_strategy __P((struct vop_strategy_args *));
261 int msdosfs_print __P((struct vop_print_args *));
262 int msdosfs_islocked __P((struct vop_islocked_args *));
263 int msdosfs_advlock __P((struct vop_advlock_args *));
264 int msdosfs_reallocblks __P((struct vop_reallocblks_args *));
265 
266 /*
267  * Internal service routine prototypes.
268  */
269 int deget __P((struct msdosfsmount * pmp, u_long dirclust, u_long diroffset, struct direntry * direntptr, struct denode ** depp));
270 #endif	/* KERNEL */
271