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1.1 root 1: /*
2: * Written by Paul Popelka ([email protected])
3: *
4: * You can do anything you want with this software,
5: * just don't say you wrote it,
6: * and don't remove this notice.
7: *
8: * This software is provided "as is".
9: *
10: * The author supplies this software to be publicly
11: * redistributed on the understanding that the author
12: * is not responsible for the correct functioning of
13: * this software in any circumstances and is not liable
14: * for any damages caused by this software.
15: *
16: * October 1992
17: *
18: * denode.h,v 1.2 1993/05/20 03:34:05 cgd Exp
19: */
20:
21: /*
22: * This is the pc filesystem specific portion of the
23: * vnode structure.
24: * To describe a file uniquely the de_dirclust, de_diroffset,
25: * and de_de.deStartCluster fields are used. de_dirclust
26: * contains the cluster number of the directory cluster containing
27: * the entry for a file or directory. de_diroffset is the
28: * index into the cluster for the entry describing a file
29: * or directory. de_de.deStartCluster is the number of the
30: * first cluster of the file or directory. Now to describe the
31: * quirks of the pc filesystem.
32: * - Clusters 0 and 1 are reserved.
33: * - The first allocatable cluster is 2.
34: * - The root directory is of fixed size and all blocks that
35: * make it up are contiguous.
36: * - Cluster 0 refers to the root directory when it is found
37: * in the startcluster field of a directory entry that points
38: * to another directory.
39: * - Cluster 0 implies a 0 length file when found in the start
40: * cluster field of a directory entry that points to a file.
41: * - You can't use the cluster number 0 to derive
42: * the address of the root directory.
43: * - Multiple directory entries can point to a directory.
44: * The entry in the parent directory points to a child
45: * directory. Any directories in the child directory contain
46: * a ".." entry that points back to the child. The child
47: * directory itself contains a "." entry that points to
48: * itself.
49: * - The root directory does not contain a "." or ".." entry.
50: * - Directory entries for directories are never changed once
51: * they are created (except when removed). The size stays
52: * 0, and the last modification time is never changed. This
53: * is because so many directory entries can point to the physical
54: * clusters that make up a directory. It would lead to an update
55: * nightmare.
56: * - The length field in a directory entry pointing to a directory
57: * contains 0 (always). The only way to find the end of a directory
58: * is to follow the cluster chain until the "last cluster"
59: * marker is found.
60: * My extensions to make this house of cards work. These apply
61: * only to the in memory copy of the directory entry.
62: * - A reference count for each denode will be kept since dos doesn't
63: * keep such things.
64: */
65:
66: /* Internal pseudo-offset for (nonexistent) directory entry for the root dir
67: * in the root dir */
68: #define PCFSROOT_OFS 0x1fffffff
69:
70: /*
71: * The fat cache structure.
72: * fc_fsrcn is the filesystem relative cluster number
73: * that corresponds to the file relative cluster number
74: * in this structure (fc_frcn).
75: */
76: struct fatcache {
77: u_short fc_frcn; /* file relative cluster number */
78: u_short fc_fsrcn; /* filesystem relative cluster number */
79: };
80:
81: /*
82: * The fat entry cache as it stands helps make extending
83: * files a "quick" operation by avoiding having to scan
84: * the fat to discover the last cluster of the file.
85: * The cache also helps sequential reads by remembering
86: * the last cluster read from the file. This also prevents
87: * us from having to rescan the fat to find the next cluster
88: * to read. This cache is probably pretty worthless if a
89: * file is opened by multiple processes.
90: */
91: #define FC_SIZE 2 /* number of entries in the cache */
92: #define FC_LASTMAP 0 /* entry the last call to pcbmap() resolved to */
93: #define FC_LASTFC 1 /* entry for the last cluster in the file */
94:
95: #define FCE_EMPTY 0xffff /* doesn't represent an actual cluster # */
96:
97: /*
98: * Set a slot in the fat cache.
99: */
100: #define fc_setcache(dep, slot, frcn, fsrcn) \
101: (dep)->de_fc[slot].fc_frcn = frcn; \
102: (dep)->de_fc[slot].fc_fsrcn = fsrcn;
103:
104: /*
105: * This is the in memory variant of a dos directory
106: * entry. It is usually contained within a vnode.
107: */
108: struct denode {
109: struct denode *de_chain[2]; /* hash chain ptrs */
110: struct vnode *de_vnode; /* addr of vnode we are part of */
111: struct vnode *de_devvp; /* vnode of blk dev we live on */
112: u_long de_flag; /* flag bits */
113: dev_t de_dev; /* device where direntry lives */
114: u_long de_dirclust; /* cluster of the directory file
115: * containing this entry */
116: u_long de_diroffset; /* ordinal of this entry in the
117: * directory */
118: long de_refcnt; /* reference count */
119: struct pcfsmount *de_pmp; /* addr of our mount struct */
120: struct lockf *de_lockf; /* byte level lock list */
121: long de_spare0; /* current lock holder */
122: long de_spare1; /* lock wanter */
123: struct direntry de_de; /* the actual directory entry */
124: struct fatcache de_fc[FC_SIZE]; /* fat cache */
125: };
126:
127: /*
128: * Values for the de_flag field of the denode.
129: */
130: #define DELOCKED 0x0001 /* directory entry is locked */
131: #define DEWANT 0x0002 /* someone wants this de */
132: #define DERENAME 0x0004 /* de is being renamed */
133: #define DEUPD 0x0008 /* file has been modified */
134: #define DESHLOCK 0x0010 /* file has shared lock */
135: #define DEEXLOCK 0x0020 /* file has exclusive lock */
136: #define DELWAIT 0x0040 /* someone waiting on file lock */
137: #define DEMOD 0x0080 /* denode wants to be written back
138: * to disk */
139:
140: /*
141: * Shorthand macros used to reference fields in the direntry
142: * contained in the denode structure.
143: */
144: #define de_Name de_de.deName
145: #define de_Extension de_de.deExtension
146: #define de_Attributes de_de.deAttributes
147: #define de_Reserved de_de.deReserved
148: #define de_Time de_de.deTime
149: #define de_Date de_de.deDate
150: #define de_StartCluster de_de.deStartCluster
151: #define de_FileSize de_de.deFileSize
152: #define de_forw de_chain[0]
153: #define de_back de_chain[1]
154:
155: #if defined(KERNEL)
156:
157: #define VTODE(vp) ((struct denode *)(vp)->v_data)
158: #define DETOV(de) ((de)->de_vnode)
159:
160: #define DELOCK(de) delock(de)
161: #define DEUNLOCK(de) deunlock(de)
162:
163: #define DEUPDAT(dep, t, waitfor) \
164: if (dep->de_flag & DEUPD) \
165: (void) deupdat(dep, t, waitfor);
166:
167: #define DETIMES(dep, t) \
168: if (dep->de_flag & DEUPD) { \
169: (dep)->de_flag |= DEMOD; \
170: unix2dostime(t, (union dosdate *)&dep->de_Date, \
171: (union dostime *)&dep->de_Time); \
172: (dep)->de_flag &= ~DEUPD; \
173: }
174:
175: /*
176: * This overlays the fid sturcture (see mount.h)
177: */
178: struct defid {
179: u_short defid_len; /* length of structure */
180: u_short defid_pad; /* force long alignment */
181:
182: u_long defid_dirclust; /* cluster this dir entry came from */
183: u_long defid_dirofs; /* index of entry within the cluster */
184:
185: /* u_long defid_gen; /* generation number */
186: };
187:
188: /*
189: * Prototypes for PCFS vnode operations
190: */
191: int pcfs_lookup __P((struct vnode *vp, struct nameidata *ndp, struct proc *p));
192: int pcfs_create __P((struct nameidata *ndp, struct vattr *vap, struct proc *p));
193: int pcfs_mknod __P((struct nameidata *ndp, struct vattr *vap, struct ucred *cred,
194: struct proc *p));
195: int pcfs_open __P((struct vnode *vp, int mode, struct ucred *cred,
196: struct proc *p));
197: int pcfs_close __P((struct vnode *vp, int fflag, struct ucred *cred,
198: struct proc *p));
199: int pcfs_access __P((struct vnode *vp, int mode, struct ucred *cred,
200: struct proc *p));
201: int pcfs_getattr __P((struct vnode *vp, struct vattr *vap, struct ucred *cred,
202: struct proc *p));
203: int pcfs_setattr __P((struct vnode *vp, struct vattr *vap, struct ucred *cred,
204: struct proc *p));
205: int pcfs_read __P((struct vnode *vp, struct uio *uio, int ioflag,
206: struct ucred *cred));
207: int pcfs_write __P((struct vnode *vp, struct uio *uio, int ioflag,
208: struct ucred *cred));
209: int pcfs_ioctl __P((struct vnode *vp, int command, caddr_t data, int fflag,
210: struct ucred *cred, struct proc *p));
211: int pcfs_select __P((struct vnode *vp, int which, int fflags, struct ucred *cred,
212: struct proc *p));
213: int pcfs_mmap __P((struct vnode *vp, int fflags, struct ucred *cred,
214: struct proc *p));
215: int pcfs_fsync __P((struct vnode *vp, int fflags, struct ucred *cred,
216: int waitfor, struct proc *p));
217: int pcfs_seek __P((struct vnode *vp, off_t oldoff, off_t newoff,
218: struct ucred *cred));
219: int pcfs_remove __P((struct nameidata *ndp, struct proc *p));
220: int pcfs_link __P((struct vnode *vp, struct nameidata *ndp, struct proc *p));
221: int pcfs_rename __P((struct nameidata *fndp, struct nameidata *tdnp,
222: struct proc *p));
223: int pcfs_mkdir __P((struct nameidata *ndp, struct vattr *vap, struct proc *p));
224: int pcfs_rmdir __P((struct nameidata *ndp, struct proc *p));
225: int pcfs_symlink __P((struct nameidata *ndp, struct vattr *vap, char *target,
226: struct proc *p));
227: int pcfs_readdir __P((struct vnode *vp, struct uio *uio, struct ucred *cred,
228: int *eofflagp));
229: int pcfs_readlink __P((struct vnode *vp, struct uio *uio, struct ucred *cred));
230: int pcfs_abortop __P((struct nameidata *ndp));
231: int pcfs_inactive __P((struct vnode *vp, struct proc *p));
232: int pcfs_reclaim __P((struct vnode *vp));
233: int pcfs_lock __P((struct vnode *vp));
234: int pcfs_unlock __P((struct vnode *vp));
235: int pcfs_bmap __P((struct vnode *vp, daddr_t bn, struct vnode **vpp,
236: daddr_t *bnp));
237: int pcfs_strategy __P((struct buf *bp));
238: int pcfs_print __P((struct vnode *vp));
239: int pcfs_islocked __P((struct vnode *vp));
240: int pcfs_advlock __P((struct vnode *vp, caddr_t id, int op, struct flock *fl,
241: int flags));
242:
243: /*
244: * Internal service routine prototypes.
245: */
246: int deget __P((struct pcfsmount *pmp, u_long dirclust, u_long diroffset,
247: struct direntry *direntptr, struct denode **depp));
248: #endif /* defined(KERNEL) */
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